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Sample records for employs tertiary-amine solvent

  1. Characterization of molybdenum interfacial crud in a uranium mill that employs tertiary-amine solvent extraction

    SciTech Connect

    Moyer, B.; McDowell, W.J.

    1983-01-01

    In the present work, samples of a molybdenum-caused green gummy interfacial crud from an operating western US uranium mill have been physically and chemically examined. Formaton of cruds of this description has been a long-standing problem in the use of tertiary amine solvent extraction for the recovery of uranium from low-grade ores (Amex Process). The crud is essentially an organic-continuous dispersion containing about 10 wt % aqueous droplets and about 37 wt % greenish-yellow crystalline solids suspended in kerosene-amine process solvent. The greenish-yellow crystals were found to be a previously unknown double salt of tertiary amine molybdophosphate with three tertiary amine chlorides having the empirical formula (R/sub 3/NH)/sub 3/(PMo/sub 12/O/sub 40/).3(R/sub 3/NH)Cl. To confirm the identification of the compound, a pure trioctylamine (TOA) analog was synthesized. In laboratory extraction experiments, it was demonstrated that organic-soluble amine molydophosphate forms slowly upon contact of TOA solvent with dilute sulfuric acid solutions containing low concentrations of molybdate and phosphate. If the organic solutions of amine molybdophosphate were then contacted with aqueous NaCl solutions, a greenish-yellow precipitate of (TOAH)/sub 3/(PMo/sub 12/O/sub 40/).3(TOAH)Cl formed at the interface. The proposed mechanism for the formation of the crud under process conditions involves build up of molybdenum in the solvent, followed by reaction with extracted phosphate to give dissolved amine molybdophosphate. The amine molybdophosphate then co-crystallizes with amine chloride, formed during the stripping cycle, to give the insoluble double salt, which precipitates as a layer of small particles at the interface. The proposed solution to the problem is the use of branched-chain, instead of straight-chain, tertiary amine extractants under the expectation that branching would increase the solubility of the double salt. 2 figures, 5 tables.

  2. Factors influencing phase-disengagement rates in solvent-extraction systems employing tertiary amine extractants

    SciTech Connect

    Moyer, B.A.; McDowell, W.J.

    1981-01-01

    The primary purpose of the present investigation was to examine the effects of amine size and structure on phase disengagement. Nine commercial tertiary amines were tested together with four laboratory-quality amines for uranium extraction and both organic-continuous (OC) and aqueous-continuous (AC) phase disengagement under Amex-type conditions. Synthetic acid sulfate solutions with and without added colloidal silica and actual ore leach solutions were used as the aqueous phases. Phase disengagement results were correlated with amine size and branching and solution wetting behavior on a silicate (glass) surface. The results suggest that the performance of some Amex systems may be improved by using branched chain tertiary amine extractants of higher molecular weight than are now normally used.

  3. Factors influencing phase disengagement rates in solvent extraction systems employing tertiary amine extractants

    SciTech Connect

    Moyer, B.A.; McDowell, W.J.

    1981-01-01

    A key structural factor affecting organic continuous phase disengagement was found to be the backbone chain length (longest chain in each alkyl group) since the OC phase disengagement measurements could be correlated vs backbone chain length on a single curve regardless of whether the amine was branched or linear. Aqueous continuous (AC) phase disengagement rate was rapid for the acid sulfate solution but decreased greatly with decreasing n when colloidal silica was added or when leach solution was used. With both leach and colloidal silica solutions, AC phase disengagement was correlated with wetting behavior of the amine systems on a glass (silicate) surface. A model based on silica attachment to the liquid/liquid interface was suggested to explain the stabilization of AC dispersions by silica and the related problem of interfacial crud formation. In addition faster AC phase disengagement and less emulsion (crud) stabilization, the larger molecular weight amines (n greater than or equal to 10) were found to have higher uranium extraction coefficients and lower tendencies to form third phases. Presumably, solubility losses to the aqueous phase are also lower. The results suggest that the performance of some Amex systems may be improved by using branched chain tertiary amine extractants of higher molecular weight than are now normally used. 10 figures, 3 tables.

  4. Structure-Function Study of Tertiary Amines as Switchable Polarity Solvents

    SciTech Connect

    Aaron D. Wilson; Frederick F. Stewart

    2014-02-01

    A series of tertiary amines have been screened for their function as switchable polarity solvents (SPS). The relative ratios of tertiary amine and carbonate species as well as maximum possible concentration were determined through quantitative 1H and 13C NMR spectroscopy. The viscosities of the polar SPS solutions were measured and ranged from near water in dilute systems through to gel formation at high concentrations. The van't Hoff indices for SPS solutions were measured through freezing point depression studies as a proxy for osmotic pressures. A new form of SPS with an amine : carbonate ratio significantly greater than unity has been identified. Tertiary amines that function as SPS at ambient pressures appear to be limited to molecules with fewer than 12 carbons. The N,N-dimethyl-n-alkylamine structure has been identified as important to the function of an SPS.

  5. Drop-interface coalescence rate in tertiary amine solvent extraction

    SciTech Connect

    Moyer, B.; McDowell, W.J.

    1983-01-01

    An important requirement for economical application of solvent extraction technology is rapid and efficient phase disengagement. However, much progress toward a clear fundamental understanding of the factors that affect phase disengagement rate will be needed before a logical approach to the problem will be possible. In this paper, the conceptual framework for the study of drop-interface coalescence in collapsing liquid/liquid dispersions is developed and the details of the experimental setup employed in the initial work are presented. The method for determining the drop-interface coalescence rate requires measurement of the average volume of drops (v/sub f/) adjacent to the interface, their number (n) per unit area of interface, and dispersed-phase throughput (Q) per unit area. Recording videomicrography for measurement of v/sub f/ and n is employed while Q is found from the changing position of the major interface as the dispersion band collapses (batch mode). Experimental results are presented for the highly purified system 0.1 M trioctylamine in o-xylene vs 0.1 M HCl, 0.9 M LiCl. Successive batch phase-mixing runs (1:1 phase ratio) using this system produced highly reproducible results, attributed to the use of high-purity chemicals and noncontaminating cell construction materials. Wall effects were found to be negligible. The results indicated that the changing throughput observed in batch experiments is brought about not only by drop size growth rates, but also by drop packing behavior and the fact that drop-interface coalescence rate changes with time.

  6. Solvent-extraction and purification of uranium(VI) and molybdenum(VI) by tertiary amines from acid leach solutions

    SciTech Connect

    La Gamma, Ana M.G.; Becquart, Elena T.; Chocron, Mauricio

    2008-07-01

    Considering international interest in the yellow-cake price, Argentina is seeking to exploit new uranium ore bodies and processing plants. A study of similar plants would suggest that solvent- extraction with Alamine 336 is considered the best method for the purification and concentration of uranium present in leaching solutions. In order to study the purification of these leach liquors, solvent-extraction tests under different conditions were performed with simulated solutions which containing molybdenum and molybdenum-uranium mixtures. Preliminary extraction tests carried out on mill acid-leaching liquors are also presented. (authors)

  7. Extraction of antimony with tertiary amines.

    PubMed

    Alian, A; Sanad, W

    1967-06-01

    The extractability of antimony(III) and (V) with tridodecylamine from various aqueous solutions is reported. Extraction from nitric and hydrofluoric acid solutions is low, but extraction from sulphuric, hydrochloric and hydrobromic solutions is high. Antimony-(III) can be separated from antimony(V) in 7M nitric acid or 0.64M hydrobromic acid. The extraction of antimony from hydrochloric acid solutions in methanol, ethanol, and acetone-water mixtures is greater than from pure aqueous solutions of the same acidity. The elements from which antimony can be separated with tertiary amines are given. PMID:18960147

  8. DIRECT SYNTHESIS OF TERTIARY AMINES IN WATER USING MICROWAVES

    EPA Science Inventory

    A direct synthesis of tertiary amines is presented that proceeds expeditiously via N-alkylation of amines using alkyl halides in alkaline aqueous medium. This environmentally benign reaction is accelerated upon exposure to microwave irradiation resulting in shortened reaction tim...

  9. Synthesis of sulfonamides via copper-catalyzed oxidative C-N bond cleavage of tertiary amines.

    PubMed

    Ji, Jing; Liu, Zhengyi; Liu, Ping; Sun, Peipei

    2016-08-01

    A copper-catalyzed coupling reaction of sulfonyl chlorides with tertiary amines via the oxidative C-N bond cleavage of tertiary amines was developed. Sulfonamides were synthesized using this strategy in moderate to good yields. The reaction was applicable to various tertiary amines, as well as sulfonyl chlorides. PMID:27356858

  10. 40 CFR 721.10090 - Tertiary amine salt of glycol succinate (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Tertiary amine salt of glycol... Specific Chemical Substances § 721.10090 Tertiary amine salt of glycol succinate (generic). (a) Chemical... as tertiary amine salt of glycol succinate (PMN P-01-595) is subject to reporting under this...

  11. 40 CFR 721.10090 - Tertiary amine salt of glycol succinate (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Tertiary amine salt of glycol... Specific Chemical Substances § 721.10090 Tertiary amine salt of glycol succinate (generic). (a) Chemical... as tertiary amine salt of glycol succinate (PMN P-01-595) is subject to reporting under this...

  12. 40 CFR 721.10090 - Tertiary amine salt of glycol succinate (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Tertiary amine salt of glycol... Specific Chemical Substances § 721.10090 Tertiary amine salt of glycol succinate (generic). (a) Chemical... as tertiary amine salt of glycol succinate (PMN P-01-595) is subject to reporting under this...

  13. 40 CFR 721.10090 - Tertiary amine salt of glycol succinate (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Tertiary amine salt of glycol... Specific Chemical Substances § 721.10090 Tertiary amine salt of glycol succinate (generic). (a) Chemical... as tertiary amine salt of glycol succinate (PMN P-01-595) is subject to reporting under this...

  14. 40 CFR 721.10090 - Tertiary amine salt of glycol succinate (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Tertiary amine salt of glycol... Specific Chemical Substances § 721.10090 Tertiary amine salt of glycol succinate (generic). (a) Chemical... as tertiary amine salt of glycol succinate (PMN P-01-595) is subject to reporting under this...

  15. 40 CFR 721.10669 - Tertiary amine alkyl ether (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Tertiary amine alkyl ether (generic). 721.10669 Section 721.10669 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10669...

  16. 40 CFR 721.10669 - Tertiary amine alkyl ether (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Tertiary amine alkyl ether (generic). 721.10669 Section 721.10669 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10669...

  17. Symmetrical bis-tertiary amines as novel CXCR4 inhibitors.

    PubMed

    Bai, Renren; Liang, Zhongxing; Yoon, Younghyoun; Liu, Shuangping; Gaines, Theresa; Oum, Yoonhyeun; Shi, Qi; Mooring, Suazette Reid; Shim, Hyunsuk

    2016-08-01

    CXCR4 inhibitors are promising agents for the treatment of cancer metastasis and inflammation. A series of novel tertiary amine derivatives targeting CXCR4 were designed, synthesized, and evaluated. The central benzene ring linker and side chains were modified and optimized to study the structure-activity relationship. Seven compounds displayed much more potent activity than the reference drug, AMD3100, in both the binding affinity assay and the blocking of Matrigel invasion functional assay. These compounds exhibited effective concentration ranging from 1 to 100 nM in the binding affinity assay and inhibited invasion from 65.3% to 100% compared to AMD3100 at 100 nM. Compound IIn showed a 50% suppressive effect against carrageenan-induced paw inflammation in a mouse model, which was as effective as the peptidic antagonist, TN14003 (48%). These data demonstrate that symmetrical bis-tertiary amines are unique CXCR4 inhibitors with high potency. PMID:27179215

  18. The Petasis Reaction: Microscale Synthesis of a Tertiary Amine Antifungal Analog

    ERIC Educational Resources Information Center

    Koroluk, Katherine J.; Jackson, Derek A.; Dicks, Andrew P.

    2012-01-01

    Students prepare a tertiary amine antifungal analog in an upper-level undergraduate organic laboratory. A microscale Petasis reaction is performed to generate a liquid compound readily characterized via IR and proton NMR spectroscopy. The biological relevance of the product is highlighted, with the tertiary amine scaffold being an important…

  19. Atomistic modeling of CO 2 capture in primary and tertiary amines - Heat of absorption and density changes

    NASA Astrophysics Data System (ADS)

    Maiti, A.; Bourcier, W. L.; Aines, R. D.

    2011-06-01

    With the aim of exploring new amine-based chemistry for CO 2 capture at large industrial scales we performed atomistic modeling of CO 2 chemisorption in aqueous solutions of primary and tertiary amines. DFT-based quantum chemical solvation calculations are shown to yield a number of important results, including the relative stability of ion species (carbamate vs. bicarbonate), heat of absorption, and density and volume changes as a function of CO 2 loading. Good agreement of simulation results with available experimental data provides confidence in the accuracy of such computational methods in predicting properties of new solvent systems and capture designs.

  20. Kinetics of the reaction between carbon dioxide and tertiary amines

    SciTech Connect

    Crooks, J.E.; Donnellan, J.P. )

    1990-02-16

    The reaction between carbon dioxide and amines is of great technical importance and has been the subject of many investigations. The authors have shown that the reaction for secondary amines in anhydrous ethanol and in aqueous solution is exclusively second-order in amine and that the zwitterion intermediate postulated by Danckwerts is probably of negligible significance in the mechanism. The reaction with tertiary amines has also been studied, but the data are less controversial. In order to complete their studies of the reactions of carbon dioxide with amines, using their conductimetric stopped-flow apparatus, they have studied this reaction for MDEA (methyldiethanolamine, IUPAC name N-methyl-2,2{prime}-iminodiethanol) and TEA (triethanolamine, IUPAC name 2,2{prime},2{double prime}-nitrilotris(ethanol)).

  1. Formation Mechanism of NDMA from Ranitidine, Trimethylamine, and Other Tertiary Amines during Chloramination: A Computational Study

    PubMed Central

    2015-01-01

    Chloramination of drinking waters has been associated with N-nitrosodimethylamine (NDMA) formation as a disinfection byproduct. NDMA is classified as a probable carcinogen and thus its formation during chloramination has recently become the focus of considerable research interest. In this study, the formation mechanisms of NDMA from ranitidine and trimethylamine (TMA), as models of tertiary amines, during chloramination were investigated by using density functional theory (DFT). A new four-step formation pathway of NDMA was proposed involving nucleophilic substitution by chloramine, oxidation, and dehydration followed by nitrosation. The results suggested that nitrosation reaction is the rate-limiting step and determines the NDMA yield for tertiary amines. When 45 other tertiary amines were examined, the proposed mechanism was found to be more applicable to aromatic tertiary amines, and there may be still some additional factors or pathways that need to be considered for aliphatic tertiary amines. The heterolytic ONN(Me)2–R+ bond dissociation energy to release NDMA and carbocation R+ was found to be a criterion for evaluating the reactivity of aromatic tertiary amines. A structure–activity study indicates that tertiary amines with benzyl, aromatic heterocyclic ring, and diene-substituted methenyl adjacent to the DMA moiety are potentially significant NDMA precursors. The findings of this study are helpful for understanding NDMA formation mechanism and predicting NDMA yield of a precursor. PMID:24968236

  2. 18O incorporation in the oxidation of N-methylcarbazole by lignin peroxidase and a model compound: a mechanistic insight into the oxidative N-demethylation of aromatic tertiary amines.

    PubMed

    Baciocchi, Enrico; Gerini, Maria Francesca; Lapi, Andrea

    2002-05-01

    Using 18O labelled reactants and/or solvent, the origin of the oxygen in the products of the oxidation of N-methylcarbazole by H2O2 catalysed by lignin peroxidase and a model compound has been determined, so getting important information about the mechanism of the oxidative N-demethylation of aromatic tertiary amines. PMID:12123061

  3. Amide bond formation through iron-catalyzed oxidative amidation of tertiary amines with anhydrides.

    PubMed

    Li, Yuanming; Ma, Lina; Jia, Fan; Li, Zhiping

    2013-06-01

    A general and efficient method for amide bond synthesis has been developed. The method allows for synthesis of tertiary amides from readily available tertiary amines and anhydrides in the presence of FeCl2 as catalyst and tert-butyl hydroperoxide in water (T-Hydro) as oxidant. Mechanistic studies indicated that the in situ-generated α-amino peroxide of tertiary amine and iminium ion act as key intermediates in this oxidative transformation. PMID:23668222

  4. Ultrafast Structural Dynamics of Tertiary Amines upon Electronic Excitation

    NASA Astrophysics Data System (ADS)

    Cheng, Xinxin; Minitti, Michael P.; Deb, Sanghamitra; Zhang, Yao; Budarz, James; Weber, Peter M.

    2011-06-01

    The structural response of several tertiary amines to electronic excitation has been investigated using Rydberg Fingerprint Spectroscopy. The 3p Rydberg states are reached by excitation with a 5.93 eV photon while 3s states are populated by electronic relaxation from 3p state. We observe binding energy shifts on ultrafast time scales in all peaks that reflect the structural change of the molecular ion cores. The shifts are in the range of 15 meV to 30 meV, within time scales of less than 500 fs, depending on the specific molecular systems and the nature of the electronic state. In cases where the p states are spectrally separate, the trends of the energy shifts are different for the p_z and p_x_y Rydberg states whereas the p_z and s states are similar. This suggests that the response of the Rydberg states to structural displacements depends on the symmetry. Very fast binding energy shifts, observed on sub-picosecond time scales, are attributed to the structural adjustment from a pyramidal to a planar structure upon Rydberg excitation. The quantitative values of the binding energy shifts can also be affected by laser chirp, which we model using simulations.

  5. Multiphoton ionization-fragmentation patterns of tertiary amines

    NASA Astrophysics Data System (ADS)

    Parker, D. H.; Bernstein, R. B.; Lichtin, D. A.

    1981-09-01

    Multiphoton ionization (MPI)-fragmentation patterns are reported for a series of normal and caged tertiary amines. Ionization is enhanced by two-photon resonance with the 3s and 3p Rydberg states of trimethylamine, triethylamine, and the caged amines quinuclidine and triethylenediamine. Over the wavelength region λ = 400-530 nm, N(CH3)3 ionizes to the parent ion (P) and fragments only by the loss of a H atom to yield the P-H daughter ion; N(C2H5)3 ionizes to its parent ion and fragments by the loss of a methyl to form the P-CH3 ion. The branching ratio of daughter to parent ions is found to be essentially independent of laser intensity but strongly dependent on laser wavelength. The caged amines quinuclidine [N(C2H4)3CH, or ABCO] and triethylenediamine [N(C2H4)3N, or DABCO] fragment extensively over this λ range in a manner dependent on both laser wavelength and intensity. The extent of daughter ion formation in N(CH3)3 and N(C2H5)3 can be understood by consideration of the wavelength regions in which the total available energy from the initial three- or four-photon ionization event exceeds the appearance potential of the given daughter ion. For the caged amines direct observation of this mechanism is masked by fragmentation due to sequential absorption of photons (during the ˜5 ns pulse duration) by the parent and/or daughter ions. The present results show that even for molecules with broad, unstructured UV absorption and MPI spectra such as N(CH3)3 and N(C2H5)3, considerable information on photon-molecule and photon-ion interactions can still be gained by the MPI mass spectrometry technique.

  6. Tertiary amine-catalyzed and direct synthesis of α-chloroalkanesulfonylhydrazines from azodicarboxylates and sulfonyl chlorides.

    PubMed

    Zhou, Bingnan; Xu, Jiaxi

    2016-06-01

    Chloroalkanesulfonylhydrazines were synthesized directly and efficiently from various alkanesulfonyl chlorides and dialkyl azodicarboxylates under the catalysis of tertiary amines. Tertiary amines serve as both bases and nucleophiles to dehydrochlorinate alkanesulfonyl chlorides to afford sulfenes. They then nucleophilically attack azodicarboxylates to yield zwitterionic intermediates, which nucleophilically attack sulfenes followed by intramolecular nucleophilic displacement and intermolecular chloride substitution to give rise to the final dialkyl α-chloroalkanesulfonylhydrazine-1,2-dicarboxylates. The proposed method provides a new and mild strategy for direct preparation of α-chloroalkanesulfonyl derivatives without other chloride resource, removing the complications incurred in traditional methods. PMID:27169623

  7. Formation of water soluble complexes of ?: solid-state reaction between tertiary amines and ?

    NASA Astrophysics Data System (ADS)

    Mohan, H.; Priyadarsini, K. I.; Tyagi, A. K.; Mittal, J. P.

    1996-11-01

    Water soluble complexes of 0953-4075/29/21/015/img3 have been prepared on solid-state mechano-chemical reaction between 0953-4075/29/21/015/img3 and tertiary amines (hexamine, DABCO) at room temperature 0953-4075/29/21/015/img5. The product is characterized by x-ray diffraction and FTIR methods. It is presumably due to the charge transfer interactions between electron affinic 0953-4075/29/21/015/img3 and electron rich tertiary amines.

  8. Reactions of hypochlorous acid with biological substrates are activated catalytically by tertiary amines.

    PubMed

    Prütz, W A

    1998-09-15

    The activation of reactions of HOCl with a variety of model substrates by tertiary amines was investigated spectroscopically by tandem-mix and stopped-flow techniques. HOCl-induced chlorination of salicylate can be sped up by several orders of magnitude by catalytic amounts of trimethylamine (TMN). The effect is obviously due to the fast generation of reactive quarternary chloramonium ions, TMN+ Cl, which act as chain carrier in a catalytic reaction cycle. Of various catalysts tested, quinine shows the highest activity; this is attributable to the quinuclidine (QN) substituent, a bicyclic tertiary amine, forming a particularly reactive chloro derivative, QN+ Cl, which does not decompose autocatalytically. The rate of catalytic salicylate chlorination as a function of pH (around pH 7) depends not at least on the basicity of the tertiary amine; the rate increases with pH in the cases of TMN and quinuclidine (high basicity), but decreases with pH in the case of MES (low basicity). Tertiary amines also catalyze the interaction between HOCl and alkenes, as shown using sorbate as model. Reaction of HOCl with the nucleotides GMP and CMP is sped up remarkably by catalytic amounts of tertiary amines. In the case of GMP the same product spectrum is produced by HOCl in absence and presence of catalyst, but a change in the product spectra is obtained when AMP and CMP are reacted with HOCl in presence of catalyst. Using poly(dA-dT).poly(dA-dT) as DNA model, it is shown that HOCl primarily induces an absorbance increase at 263 nm, which indicates unfolding of the double strand due to fast chlorination of thymidine; a subsequent secondary absorbance decrease can be explained by slow chlorination of adenosine. Both the primary and secondary processes are activated by catalytic amounts of quinine. No evidence was found for a radical pathway in TMN-mediated oxidation of formate by HOCl. The present results suggest that low concentrations of certain tertiary amines have the potential

  9. Discovery of Tertiary Amine and Indole Derivatives as Potent RORγt Inverse Agonists.

    PubMed

    Yang, Ting; Liu, Qian; Cheng, Yaobang; Cai, Wei; Ma, Yingli; Yang, Liuqing; Wu, Qianqian; Orband-Miller, Lisa A; Zhou, Ling; Xiang, Zhijun; Huxdorf, Melanie; Zhang, Wei; Zhang, Jing; Xiang, Jia-Ning; Leung, Stewart; Qiu, Yang; Zhong, Zhong; Elliott, John D; Lin, Xichen; Wang, Yonghui

    2014-01-01

    A novel series of tertiary amines as retinoid-related orphan receptor gamma-t (RORγt) inverse agonists was discovered through agonist/inverse agonist conversion. The level of RORγt inhibition can be enhanced by modulating the conformational disruption of H12 in RORγt LBD. Linker exploration and rational design led to the discovery of more potent indole-based RORγt inverse agonists. PMID:24900774

  10. Formation of NDMA and halogenated DBPs by chloramination of tertiary amines: the influence of bromide ion.

    PubMed

    Le Roux, Julien; Gallard, Hervé; Croué, Jean-Philippe

    2012-02-01

    The formation of NDMA and other DBPs (including THMs, HANs, and HKs) has been investigated by chloramination of several tertiary amines in the absence and presence of bromide ion. NDMA formation from the most reactive tertiary amines (e.g., dimethylaminomethylfurfuryl alcohol or DMP30) was enhanced in the presence of bromide due to the formation of brominated oxidant species such as bromochloramine (NHBrCl) and the hypothetical UDMH-Br as an intermediate. The formation of NDMA by chloramination of less reactive model compounds was inhibited in the presence of bromide. This can be explained by competitive reactions leading to the production of brominated DBPs (i.e., THMs). In the presence of bromide, the formation of brominated THMs during chloramination can be attributed to the presence of small amounts of HOBr produced by the decomposition of chloramines and bromamines. The results are of particular interest to understand NDMA formation mechanisms, especially during chloramination of wastewaters impacted by anthropogenic tertiary amines and containing bromide ion. PMID:22214364

  11. Structure-Function Relationships of a Tertiary Amine-Based Polycarboxybetaine.

    PubMed

    Lee, Chen-Jung; Wu, Haiyan; Tang, Qiong; Cao, Bin; Wang, Huifeng; Cong, Hongbo; Zhe, Jiang; Xu, Fujian; Cheng, Gang

    2015-09-15

    Zwitterionic polycarboxybetaine (PCB) materials have attracted noticeable interest for biomedical applications, such as wound healing/tissue engineering, medical implants, and biosensors, due to their excellent antifouling properties and design flexibility. Antifouling materials with buffering capability are particularly useful for many biomedical applications. In this work, an integrated zwitterionic polymeric material, poly(2-((2-hydroxyethyl)(2-methacrylamidoethyl)ammonio)acetate) (PCBMAA-1T), was synthesized to carry desired properties (antifouling, switchability and buffering capability). A tertiary amine was used to replace quaternary ammonium as the cation to endow the materials with buffering capability under neutral pH. Through this study, a better understanding on the structure-property relationship of zwitterionic materials was obtained. The tertiary amine cation does not compromise antifouling properties of zwitterionic materials. The amount of adsorbed proteins on PCBMAA-1T polymer brushes is less than 0.8 ng/cm(2) for fibrinogen and 0.3 ng/cm(2) (detection limit of the surface plasmon resonance sensor) for both undiluted blood plasma and serum. It is found that the tertiary amine is favorable to obtain good lactone ring stability in switchable PCB materials. Titration study showed that PCBMAA-1T could resist pH changes under both acidic (pH 1-3) and neutral/basic (pH 7-9) conditions. To the best of our knowledge, such an all-in-one material has not been reported. We believe this material might be potentially used for a variety of applications, including tissue engineering, chronic wound healing and medical device coating. PMID:26331774

  12. Kinetic resolution of acids in acylation reactions in the presence of chiral tertiary amines

    SciTech Connect

    Potapov, V.M.; Dem'yanovich, V.M.; Khlebnikov, V.A.

    1988-07-10

    Asymmetric synthesis has now become an important method for the production of optically active compounds, and its most attractive form is asymmetric catalysis. This work was devoted to an investigation into asymmetric catalysis with chiral tertiary amines in acylation reactions. During the acylation of alcohols and amines by the action of racemic 2-phenylpropionic and 2-methyl-3-phenylpropionic acids in the presence of S-nicotine the initial acids are resolved kinetically. The (R)-2-phenylpropionic acid obtained in this way had an optical purity of 0.5-1.5%.

  13. Investigating the effects of block versus statistical glycopolycations containing primary and tertiary amines for plasmid DNA delivery.

    PubMed

    Sprouse, Dustin; Reineke, Theresa M

    2014-07-14

    Polymer composition and morphology can affect the way polymers interact with biomolecules, cell membranes, and intracellular components. Herein, diblock, triblock, and statistical polymers that varied in charge center type (primary and/or tertiary amines) were synthesized to elucidate the role of polymer composition on plasmid DNA complexation, delivery, and cellular toxicity of the resultant polyplexes. The polymers were synthesized via RAFT polymerization and were composed of a carbohydrate moiety, 2-deoxy-2-methacrylamido glucopyranose (MAG), a primary amine group, N-(2-aminoethyl) methacrylamide (AEMA), and/or a tertiary amine moiety, N,N-(2-dimethylamino)ethyl methacrylamide (DMAEMA). The lengths of both the carbohydrate and cationic blocks were kept constant while the primary amine to tertiary amine ratio was varied within the polymers. The polymers were characterized via nuclear magnetic resonance (NMR) and size exclusion chromatography (SEC), and the polyplex formulations with pDNA were characterized in various media using dynamic light scattering (DLS). Polyplexes formed with the block copolymers were found to be more colloidally stable than statistical copolymers with similar composition, which rapidly aggregated to micrometer sized particles. Also, polymers composed of a higher primary amine content were more colloidally stable than polymers consisting of the tertiary amine charge centers. Plasmid DNA internalization, transgene expression, and toxicity were examined with each polymer. As the amount of tertiary amine in the triblock copolymers increased, both gene expression and toxicity were found to increase. Moreover, it was found that increasing the content of tertiary amines imparted higher membrane disruption/destabilization. While both block and statistical copolymers had high transfection efficiencies, some of the statistical systems exhibited both higher transfection and toxicity than the analogous block polymers, potentially due to the lack of a

  14. Investigating the Effects of Block versus Statistical Glycopolycations Containing Primary and Tertiary Amines for Plasmid DNA Delivery

    PubMed Central

    2015-01-01

    Polymer composition and morphology can affect the way polymers interact with biomolecules, cell membranes, and intracellular components. Herein, diblock, triblock, and statistical polymers that varied in charge center type (primary and/or tertiary amines) were synthesized to elucidate the role of polymer composition on plasmid DNA complexation, delivery, and cellular toxicity of the resultant polyplexes. The polymers were synthesized via RAFT polymerization and were composed of a carbohydrate moiety, 2-deoxy-2-methacrylamido glucopyranose (MAG), a primary amine group, N-(2-aminoethyl) methacrylamide (AEMA), and/or a tertiary amine moiety, N,N-(2-dimethylamino)ethyl methacrylamide (DMAEMA). The lengths of both the carbohydrate and cationic blocks were kept constant while the primary amine to tertiary amine ratio was varied within the polymers. The polymers were characterized via nuclear magnetic resonance (NMR) and size exclusion chromatography (SEC), and the polyplex formulations with pDNA were characterized in various media using dynamic light scattering (DLS). Polyplexes formed with the block copolymers were found to be more colloidally stable than statistical copolymers with similar composition, which rapidly aggregated to micrometer sized particles. Also, polymers composed of a higher primary amine content were more colloidally stable than polymers consisting of the tertiary amine charge centers. Plasmid DNA internalization, transgene expression, and toxicity were examined with each polymer. As the amount of tertiary amine in the triblock copolymers increased, both gene expression and toxicity were found to increase. Moreover, it was found that increasing the content of tertiary amines imparted higher membrane disruption/destabilization. While both block and statistical copolymers had high transfection efficiencies, some of the statistical systems exhibited both higher transfection and toxicity than the analogous block polymers, potentially due to the lack of a

  15. Highly porous organic polymers bearing tertiary amine group and their exceptionally high CO2 uptake capacities

    NASA Astrophysics Data System (ADS)

    Gomes, Ruth; Bhaumik, Asim

    2015-02-01

    We report a very simple and unique strategy for synthesis of a tertiary amine functionalized high surface area porous organic polymer (POP) PDVTA-1 through the co-polymerization of monomers divinylbenzene (DVB) and triallylamine (TAA) under solvothermal reaction conditions. Two different PDVTA-1 samples have been synthesized by varying the molar ratio of the monomers. The porous polymeric materials have been thoroughly characterized by solid state 13C CP MAS-NMR, FT-IR and UV-vis spectroscopy, N2 sorption, HR TEM and FE SEM to understand its chemical environment, nanostructure, bonding, morphology and related surface properties. PDVTA-1 with higher amine content (DVB/TAA=4.0) showed exceptionally high CO2 uptake capacity of 85.8 wt% (19.5 mmol g-1) at 273 K and 43.69 wt% (9.93 mmol g-1) at 298 K under 3 bar pressure, whereas relatively low amine loaded material (DVB/TAA=7.0) shows uptake capacity of 59.2 wt% (13.45 mmol g-1) at 273 K and 34.36 wt% (7.81 mmol g-1) at 298 K. Highly porous nanostructure together with very high surface area and basicity at the surface due to the presence of abundant basic tertiary amine N-sites in the framework of PDVTA-1 could be responsible for very high CO2 adsorption.

  16. Tertiary amines related to brompheniramine: preferred conformations for N-oxygenation by the hog liver flavin-containing monooxygenase.

    PubMed

    Cashman, J R; Celestial, J R; Leach, A; Newdoll, J; Park, S B

    1993-08-01

    The metabolism of racemic, (D)- and (L)-brompheniramine, a widely used antihistamine, was studied with microsomes and with highly purified flavin-containing monooxygenase (FMO) from hog liver. In addition, a number of other similar tertiary amines were evaluated as substrates for FMO activity from hog liver and the kinetic constants obtained were compared with brompheniramine. Although some N-demethylation was observed, the major metabolite of brompheniramine and the other tertiary amines examined in hog liver microsomes was the metabolite containing an aliphatic nitrogen N-oxide. Brompheniramine was extensively N-oxygenated by the highly purified FMO from hog liver. N-Oxygenation of brompheniramine in both microsomes and with highly purified FMO from hog liver was enantioselective. The Km for N-oxygenation of (D)-brompheniramine was markedly lower than the Km for (L)-brompheniramine. (E)- and (Z)-zimeldine are less conformationally flexible model compounds of brompheniramine, and these compounds were also examined and were found to be stereoselectively N-oxygenated by the highly purified FMO from hog liver. The similarities and differences in Km and Vmax values were evaluated in terms of possible conformations of the substrates determined by SYBYL molecular mechanics calculations. Distance map data indicated that FMO preferentially accommodated selected conformations of tertiary amines. Thus, (D)-brompheniramine and (Z)-zimeldine presumably have the aliphatic tertiary amine nitrogen atom and aromatic ring center at a defined distance and geometry and were more efficiently N-oxygenated than their respective isomers. PMID:8415393

  17. Upregulation of BMSCs Osteogenesis by Positively-Charged Tertiary Amines on Polymeric Implants via Charge/iNOS Signaling Pathway

    NASA Astrophysics Data System (ADS)

    Zhang, Wei; Liu, Na; Shi, Haigang; Liu, Jun; Shi, Lianxin; Zhang, Bo; Wang, Huaiyu; Ji, Junhui; Chu, Paul K.

    2015-03-01

    Positively-charged surfaces on implants have a similar potential to upregulate osteogenesis of bone marrow-derived mesenchymal stem cells (BMSCs) as electromagnetic therapy approved for bone regeneration. Generally, their osteogenesis functions are generally considered to stem from the charge-induced adhesion of extracellular matrix (ECM) proteins without exploring the underlying surface charge/cell signaling molecule pathways. Herein, a positively-charged surface with controllable tertiary amines is produced on a polymer implant by plasma surface modification. In addition to inhibiting the TNF-α expression, the positively-charged surface with tertiary amines exhibits excellent cytocompatibility as well as remarkably upregulated osteogenesis-related gene/protein expressions and calcification of the contacted BMSCs. Stimulated by the charged surface, these BMSCs display high iNOS expressions among the three NOS isoforms. Meanwhile, downregulation of the iNOS by L-Can or siRNA inhibit osteogenic differentiation in the BMSCs. These findings suggest that a positively-charged surface with tertiary amines induces osteogenesis of BMSCs via the surface charge/iNOS signaling pathway in addition to elevated ECM protein adhesion. Therefore, creating a positively-charged surface with tertiary amines is a promising approach to promote osseointegration with bone tissues.

  18. Brønsted acid cocatalysis in photocatalytic intramolecular coupling of tertiary amines: efficient synthesis of 2-arylindols.

    PubMed

    Yuan, Xiaoqian; Wu, Xinxin; Dong, Shupeng; Wu, Guibing; Ye, Jinxing

    2016-08-21

    We report herein a highly efficient intramolecular coupling reaction of tertiary amines and ketones (α,β-unsaturated ketones) by using a Brønsted acid as a cocatalyst, affording 2-arylindols in good to excellent yields (up to 92%) under visible light irradiation at room temperature. PMID:27431277

  19. PROCESS FOR EXTRACTING NEPTUNIUM AND PLUTONIUM FROM NITRIC ACID SOLUTIONS OF SAME CONTAINING URANYL NITRATE WITH A TERTIARY AMINE

    DOEpatents

    Sheppard, J.C.

    1962-07-31

    A process of selectively extracting plutonium nitrate and neptunium nitrate with an organic solution of a tertiary amine, away from uranyl nitrate present in an aqueous solution in a maximum concentration of 1M is described. The nitric acid concentration is adjusted to about 4M and nitrous acid is added prior to extraction. (AEC)

  20. Upregulation of BMSCs Osteogenesis by Positively-Charged Tertiary Amines on Polymeric Implants via Charge/iNOS Signaling Pathway

    PubMed Central

    Zhang, Wei; Liu, Na; Shi, Haigang; Liu, Jun; Shi, Lianxin; Zhang, Bo; Wang, Huaiyu; Ji, Junhui; Chu, Paul K.

    2015-01-01

    Positively-charged surfaces on implants have a similar potential to upregulate osteogenesis of bone marrow-derived mesenchymal stem cells (BMSCs) as electromagnetic therapy approved for bone regeneration. Generally, their osteogenesis functions are generally considered to stem from the charge-induced adhesion of extracellular matrix (ECM) proteins without exploring the underlying surface charge/cell signaling molecule pathways. Herein, a positively-charged surface with controllable tertiary amines is produced on a polymer implant by plasma surface modification. In addition to inhibiting the TNF-α expression, the positively-charged surface with tertiary amines exhibits excellent cytocompatibility as well as remarkably upregulated osteogenesis-related gene/protein expressions and calcification of the contacted BMSCs. Stimulated by the charged surface, these BMSCs display high iNOS expressions among the three NOS isoforms. Meanwhile, downregulation of the iNOS by L-Can or siRNA inhibit osteogenic differentiation in the BMSCs. These findings suggest that a positively-charged surface with tertiary amines induces osteogenesis of BMSCs via the surface charge/iNOS signaling pathway in addition to elevated ECM protein adhesion. Therefore, creating a positively-charged surface with tertiary amines is a promising approach to promote osseointegration with bone tissues. PMID:25791957

  1. Supported Gold Nanoparticles for Efficient α-Oxygenation of Secondary and Tertiary Amines into Amides.

    PubMed

    Jin, Xiongjie; Kataoka, Kengo; Yatabe, Takafumi; Yamaguchi, Kazuya; Mizuno, Noritaka

    2016-06-13

    Although the α-oxygenation of amines is a highly attractive method for the synthesis of amides, efficient catalysts suited to a wide range of secondary and tertiary alkyl amines using O2 as the terminal oxidant have no precedent. This report describes a novel, green α-oxygenation of a wide range of linear and cyclic secondary and tertiary amines mediated by gold nanoparticles supported on alumina (Au/Al2 O3 ). The observed catalysis was truly heterogeneous, and the catalyst could be reused. The present α-oxygenation utilizes O2 as the terminal oxidant and water as the oxygen atom source of amides. The method generates water as the only theoretical by-product, which highlights the environmentally benign nature of the present reaction. Additionally, the present α-oxygenation provides a convenient method for the synthesis of (18) O-labeled amides using H2 (18) O as the oxygen source. PMID:27151621

  2. CO2-responsive aliphatic tertiary amine-modified alginate and its application as a switchable surfactant.

    PubMed

    Yang, Jisheng; Dong, Hongbiao

    2016-11-20

    A new kind of hexyl diethyl tertiary amine-grafted amphiphilic alginate derivative (HDEA-Alg) was synthesized from (6-bromo-hexyl)-diethyl-amine (BHDEA) and sodium alginate (NaAlg) through esterification. The structure of HDEA-Alg was confirmed by FT-IR and NMR spectroscopies. The grafting ratio was calculated according elemental analysis and thermodynamic property was analyzed by TG. The CO2/N2-responsive performance of HDEA-Alg in aqueous solution was demonstrated by surface tension and conductivity measurements. Stable emulsions of liquid paraffin were easily prepared in the presence of the HDEA-Alg. These emulsions can be de-emulsified by bubbling CO2 through the emulsions at 5°C for 30min, resulting in complete oil/water phase separations. They can be re-emulsified by bubbling N2 through the solutions at 50°C for 30min with the aid of homogenization. PMID:27561465

  3. Regulation of carbon partitioning into carotenes by MPTA, a substituted tertiary amine

    SciTech Connect

    Madhavan, S.; Rosenfield, C.L.; Benedict, C.R.

    1986-04-01

    In mature citrus fruits, synthesis and turnover of carotenes appears to be low. Treatment of lemon pieces with the substituted tertiary amine, 2-(4-methylphenoxyl)triethylamine, MPTA, induces the synthesis of carotenes. Exposure of tissue slices (lemon flavedo) to MPTA for 72 hrs results in the production of 29.6 ..mu..g gfrwt/sup -1/ lycopene whereas control slices showed only trace amounts of lycopene. An identical incorporation of /sup 14/C-glucose into sugars, amino acids and organic acids, in both treated and control tissue slices indicates the non-disturbance of fruit respiration by MPTA treatment. Incorporation of /sup 14/C-glucose into carotenes is negligible in mature citrus fruits, but in MPTA treated tissue slices there is a pronounced incorporation of /sup 14/C-glucose into carotenes. MPTA treatment induces the synthesis of carotene enzymes, thus effecting an increased partitioning of glucose into the MVA pathway for carotene synthesis.

  4. Dual Palladium(II)/Tertiary Amine Catalysis for Asymmetric Regioselective Rearrangements of Allylic Carbamates.

    PubMed

    Bauer, Johannes Moritz; Frey, Wolfgang; Peters, René

    2016-04-11

    The streamlined catalytic access to enantiopure allylic amines as valuable precursors towards chiral β- and γ-aminoalcohols as well as α- and β-aminoacids is desirable for industrial purposes. In this article an enantioselective method is described that transforms achiral allylic alcohols and N-tosylisocyanate in a single step into highly enantioenriched N-tosyl protected allylic amines via an allylic carbamate intermediate. The latter is likely to undergo a cyclisation-induced [3,3]-rearrangement catalysed by a planar chiral pentaphenylferrocene palladacycle in cooperation with a tertiary amine base. The otherwise often indispensable activation of palladacycle catalysts by a silver salt is not required in the present case and there is also no need for an inert gas atmosphere. To further improve the synthetic value, the rearrangement was used to form dimethylaminosulfonyl-protected allylic amines, which can be deprotected under non-reductive conditions. PMID:26990446

  5. Thermodynamic and Experimental Study of the Energetic Cost Involved in the Capture of Carbon Dioxide by Aqueous Mixtures of Commonly Used Primary and Tertiary Amines.

    PubMed

    Arcis, Hugues; Coulier, Yohann; Coxam, Jean-Yves

    2016-01-01

    The capture of carbon dioxide with chemical solvents is one solution to mitigate greenhouse gas emissions from anthropogenic sources and thus tackle climate change. Recent research has been focused on optimizing new kinds of advanced absorbents including aqueous amine blends, but critical downsides such as the large energetic cost involved with the industrial process remain. To address this issue, a better understanding of the energetic interactions existing in solution is necessary. In this paper, we report direct experimental measurements of the energy cost involved in the solvation of CO2 in two aqueous amine blends at different temperatures. The chemical solvents were designed as aqueous mixtures of commonly used primary and tertiary amines to study the influence of the different chemical properties inferred by the amine class. We have also applied a thermodynamic model to represent the energetic effects that take place in solution during CO2 dissolution in these mixtures, where all parameters were taken from previous studies focused on single amine absorbents. The noteworthy agreement observed with the reported experimental heats of absorption and with literature vapor liquid equilibrium properties confirmed the relevance of the underlying molecular mechanisms considered in our model, and suggest that this model would prove useful to investigate CO2 dissolution in other amine blends. PMID:26630087

  6. Simultaneous detection of monoethanolamine, diethanolamine, and triethanolamine by HPLC with a chemiluminescence reaction and online derivatization to tertiary amine.

    PubMed

    Niina, Nobumitsu; Kodamatani, Hitoshi; Uozumi, Kayoko; Kokufu, Yuki; Saito, Keiitsu; Yamazaki, Shigeo

    2005-05-01

    In this paper we propose a new postcolumn detection method for compounds having primary, secondary, and tertiary amine moieties. The primary and secondary amine are delivatized by a reaction with epichlorohydrin having an epoxy moiety in a reaction coil to yield a tertiary amine with subsequent chemiluminescence detection using [Ru(bpy)3]3+. The liner values of the calibration curves of monoethanolamine (MEA), diethanolamine (DEA) and triethanolamine (TEA) were 0.02 - 1.0 nmol (r2 = 0.9986), 0.02 - 0.5 nmol (r2 = 0.9993) and 0.1 - 1.0 nmol (r2 = 0.9482), respectively. Also, the detection limits (S/N = 3) of MEA, DEA and TEA were 30, 25 and 40 pmol, respectively. The amount of DEA and TEA in shaving cream (60 microg/20 microL) were found to be 0.3 nmol and 14 nmol, respectively, by the proposed method. PMID:15913135

  7. (E)-α,β-unsaturated amides from tertiary amines, olefins and CO via Pd/Cu-catalyzed aerobic oxidative N-dealkylation.

    PubMed

    Shi, Renyi; Zhang, Hua; Lu, Lijun; Gan, Pei; Sha, Yuchen; Zhang, Heng; Liu, Qiang; Beller, Matthias; Lei, Aiwen

    2015-02-21

    A novel Pd/Cu-catalyzed chemoselective aerobic oxidative N-dealkylation/carbonylation reaction has been developed. Tertiary amines are utilized as a "reservoir" of "active" secondary amines in this transformation, which inhibits the formation of undesired by-products and the deactivation of the catalysts. This protocol allows for an efficient and straightforward construction of synthetically useful and bioactive (E)-α,β-unsaturated amide derivatives from easily available tertiary amines, olefins and CO. PMID:25610923

  8. Carbon Dioxide Sequestration by Using a Model Carbonic Anhydrase Complex in Tertiary Amine Medium.

    PubMed

    Sivanesan, Dharmalingam; Choi, Youngju; Lee, Jiyeon; Youn, Min Hye; Park, Ki Tae; Grace, Andrew Nirmala; Kim, Hak-Joo; Jeong, Soon Kwan

    2015-12-01

    Globally, the elevation of carbon dioxide (CO2 ) levels due to the anthropogenic effect poses a serious threat to the ecosystem. Hence, it is important to control and/or mitigate the level of CO2 in the atmosphere, which necessitates novel tools. Herein, it is proposed to improve CO2 sequestration by using model complexes based on the enzyme carbonic anhydrase (CA) in aqueous tertiary amine medium. The effect of substituents on the model CA model complexes on CO2 absorption and desorption was determined by using a stopped-flow spectrophotometer to follow pH changes through coupling to pH indicator and a continuous stirred-tank reactor (CSTR). The CO2 hydration rate constants were determined under basic conditions and compound 6, which contained a hydrophilic group, showed the highest absorption or hydration levels of CO2 (2.860×10(3)  L mol(-1)  s(-1) ). In addition, CSTR results for the absorption and desorption of CO2 suggest that simple model CA complexes could be used in post-combustion processing. PMID:26564396

  9. Modeling the simultaneous transport of two acid gases in tertiary amines with reversible reactions

    SciTech Connect

    Al-Ghawas, H.A.; Sandall, O.C.

    1988-10-01

    The objective of this work is to develop a model for the simultaneous mass transfer of two acid gases in tertiary amines accompanied by reversible chemical reactions. The model has been applied to the industrially important system of simultaneous absorption or desorption of CO/sub 2/ and H/sub 2/S in aqueous methyldiethanolamine (MDEA). In most applications the treated gas must be virtually free of H/sub 2/S; however, it is often not necessary or economical to remove substantial amounts of CO/sub 2/. Hence, selective removal of H/sub 2/S from gas streams such as natural or synthetic gases which contain CO/sub 2/ is desirable. In this research a film theory model describing the simultaneous diffusion and reversible reaction of two gases into reactive liquid has been used to predict the mass transfer enhancement factors of CO/sub 2/ and H/sub 2/S in aqueous MDEA solutions. The resulting unstable two point boundary value problem has been solved numerically for a range of the dimensionless parameters that characterize an important application for this system. In studying the simultaneous transport of CO/sub 2/ and H/sub 2/S, it is found that the reversibility of the reactions, under certain conditions, causes desorption to take place although absorption would be expected on the basis of overall driving forces. This showed that not only enhancement factors larger but also smaller than unity and even negative values are possible.

  10. Paternal employment in solvent related occupations and adverse pregnancy outcomes.

    PubMed

    Daniell, W E; Vaughan, T L

    1988-03-01

    Washington State birth certificates were examined for associations between adverse pregnancy outcomes and paternal employment in solvent exposed occupations. Four cohorts defined by live, singleton births to fathers usually employed as auto body shop workers, painters (construction and maintenance), printers, or fibreglass workers were compared retrospectively with both a systematically selected control cohort and a low solvent exposed, occupationally defined control cohort (paternal electricians). The effects of maternal race and medical illness were controlled by sample restriction; maternal age and gravidity by stratified analysis. There was evidence of increased risk of low birth weight for infants born to fathers employed as body shop workers (relative risk = 1.6; 95% confidence interval = 1.1-2.4) or painters (RR = 1.4; CI = 0.9-2.1) when compared with the systematically selected controls but not with the electrician controls. The excess risk appeared stronger when only term infants were analysed suggesting a mechanism of growth retardation rather than prematurity. There was no evidence of increased risk among the other exposed cohorts or for other adverse pregnancy outcomes. Several design features limit the interpretation of the findings and confirmation by other studies is needed. PMID:3348995

  11. Chemoselective Reductive Amination of Carbonyl Compounds for the Synthesis of Tertiary Amines Using SnCl2·2H2O/PMHS/MeOH.

    PubMed

    Nayal, Onkar S; Bhatt, Vinod; Sharma, Sushila; Kumar, Neeraj

    2015-06-01

    Stannous chloride catalyzed chemoselective reductive amination of a variety of carbonyl compounds with aromatic amines has been developed for the synthesis of a diverse range of tertiary amines using inexpensive polymethylhydrosiloxane as reducing agent in methanol. The present method is also applicable for the synthesis of secondary amines including heterocyclic ones. PMID:25938581

  12. Bifunctional tertiary amine-squaramide catalyzed asymmetric catalytic 1,6-conjugate addition/aromatization of para-quinone methides with oxindoles.

    PubMed

    Deng, Yu-Hua; Zhang, Xiang-Zhi; Yu, Ke-Yin; Yan, Xu; Du, Ji-Yuan; Huang, Hanmin; Fan, Chun-An

    2016-03-01

    The asymmetric catalytic 1,6-addition of p-QMs with racemic oxindoles under the bifunctional catalysis of C2-symmetric dimeric Cinchona-derived squaramide is described. This tertiary amine-squaramide catalyzed reaction provides a diastereoselective and enantioselective approach to the effective assembly of diverse diarylmethine-substituted oxindoles having vicinal tertiary and quaternary stereocenters. PMID:26908307

  13. Organocatalyzed asymmetric oxidative coupling of α-Csp3-H of tertiary amines to α,β-unsaturated γ-butyrolactam: synthesis of MBH-type products.

    PubMed

    Ma, Yunxia; Zhang, Gen; Zhang, Jinlong; Yang, Dongxu; Wang, Rui

    2014-10-17

    A unique organocatalytic asymmetric oxidative cross-dehydrogenative coupling of a α-Csp(3)-H bond of tertiary amines with α,β-unsaturated γ-butyrolactams to generate Morita-Baylis-Hillman-type products has been realized for the first time. This method provides an efficient way to access a series of α-heterocyclic optically active tetrahydroisoquinoline scaffolds. PMID:25260156

  14. Highly porous organic polymers bearing tertiary amine group and their exceptionally high CO{sub 2} uptake capacities

    SciTech Connect

    Gomes, Ruth; Bhaumik, Asim

    2015-02-15

    We report a very simple and unique strategy for synthesis of a tertiary amine functionalized high surface area porous organic polymer (POP) PDVTA-1 through the co-polymerization of monomers divinylbenzene (DVB) and triallylamine (TAA) under solvothermal reaction conditions. Two different PDVTA-1 samples have been synthesized by varying the molar ratio of the monomers. The porous polymeric materials have been thoroughly characterized by solid state {sup 13}C CP MAS-NMR, FT-IR and UV–vis spectroscopy, N{sub 2} sorption, HR TEM and FE SEM to understand its chemical environment, nanostructure, bonding, morphology and related surface properties. PDVTA-1 with higher amine content (DVB/TAA=4.0) showed exceptionally high CO{sub 2} uptake capacity of 85.8 wt% (19.5 mmol g{sup −1}) at 273 K and 43.69 wt% (9.93 mmol g{sup −1}) at 298 K under 3 bar pressure, whereas relatively low amine loaded material (DVB/TAA=7.0) shows uptake capacity of 59.2 wt% (13.45 mmol g{sup −1}) at 273 K and 34.36 wt% (7.81 mmol g{sup −1}) at 298 K. Highly porous nanostructure together with very high surface area and basicity at the surface due to the presence of abundant basic tertiary amine N-sites in the framework of PDVTA-1 could be responsible for very high CO{sub 2} adsorption. - Graphical abstract: Exceptionally high CO2 uptake (85.8 wt % at 273 K) has been observed over a high surface area porous organic polymer PDVTA-1 synthesized through copolymerization of divinylbenzene and triallyl amine. - Highlights: • Designing the synthesis of a new N-rich cross-linked porous organic polymer PDVTA-1. • PDVTA-1 showed mesoporosity with very high surface area of 903 m{sup 2} g{sup −1}. • High surface area and presence of basic sites facilitates the CO{sub 2} uptake. • PDVTA-1 showed exceptionally high CO{sub 2} adsorption capacity of 85.8 wt% at 273 K, 3 bar pressure.

  15. Tertiary Amine Pyrazolones and Their Salts as Inhibitors of Mutant Superoxide Dismutase 1-Dependent Protein Aggregation for the Treatment of Amyotrophic Lateral Sclerosis.

    PubMed

    Zhang, Yinan; Zhao, Kevin Tianmeng; Fox, Susan G; Kim, Jinho; Kirsch, Donald R; Ferrante, Robert J; Morimoto, Richard I; Silverman, Richard B

    2015-08-13

    Pyrazolone derivatives have previously been found to be inhibitors of Cu/Zn superoxide dismutase 1 (SOD1)-dependent protein aggregation, which extended survival of an amyotrophic lateral sclerosis (ALS) mouse model. On the basis of ADME analysis, we describe herein a new series of tertiary amine-containing pyrazolones and their structure-activity relationships. Further conversion to the conjugate salts greatly improved their solubility. Phosphate compound 17 exhibited numerous benefits both to cellular activity and to CNS-related drug-like properties in vitro and in vivo, including microsomal stability, tolerated toxicity, and blood-brain barrier permeation. These results indicate that tertiary amine pyrazolones comprise a valuable class of ALS drug candidates. PMID:26186011

  16. I2-Catalyzed Aerobic Oxidative C(sp(3))-H Amination/C-N Cleavage of Tertiary Amine: Synthesis of Quinazolines and Quinazolinones.

    PubMed

    Yan, Yizhe; Xu, Ying; Niu, Bin; Xie, Huifang; Liu, Yanqi

    2015-06-01

    An iodine-catalyzed oxidative C(sp(3))-H amination/C-N cleavage of tertiary amines couducted under an oxygen atmosphere has been developed and affords a route to quinazolines and quinazolinones in good to excellent yields via a domino ring annulation. The method is metal-free, peroxide-free, and operationally simple to implement with a wide scope of substrates and represents a new avenue for multiple C-N bond formations. PMID:25942678

  17. Two coordination polymers constructed from a multidentate carboxylic acid ligand with a tertiary amine serve as acid-base catalysts for the synthesis of chloropropene carbonate from CO2 under atmospheric pressure.

    PubMed

    Chen, Chao; Zhang, Jun; Li, Guanghua; Shen, Pan; Jin, Haichao; Zhang, Ning

    2014-10-01

    Two new coordination polymers, [Ni(H2O)(Hpdcd)(H2O)2]·DMF (1) and [Co(H2O)(Hpdcd)(H2O)2]·DMF (2) (H3pdcd = 1-(4-carboxyphenyl)-2,5-dimethyl, 1H-pyrrole-3,4-dicarboxylic acid), which were designed based on a tertiary amine ligand, were synthesized and characterized using multiple spectroscopy techniques, including single-crystal X-ray diffraction. These two 1D linear chains possess the properties of both a Lewis acid and organic base, which was confirmed by temperature programmed desorption of ammonia and on-line mass spectrometry (NH3-TPD-MS), and selective sorption for carbon dioxide. Due to their acid-base properties, the compounds exhibited high catalytic activity, in the absence of co-catalysts, for solvent-free synthesis of chloropropene carbonate from CO2 and epichlorohydrin under atmospheric CO2 pressure. The yields of chloropropene carbonate were 88% and 87% for 1 and 2, respectively, under the optimized conditions. PMID:25113602

  18. A new strategy for preparation of hair slurries using cryogenic grinding and water-soluble tertiary-amines medium

    NASA Astrophysics Data System (ADS)

    Kamogawa, Marcos Y.; Nogueira, Ana Rita A.; Costa, Letícia M.; Garcia, Edivaldo E.; Nóbrega, Joaquim A.

    2001-10-01

    The investigation of trace metal contents in hair can be used as an index of exposure to potentially toxic elements. Direct determination of Cd, Cu and Pb in slurries of hair samples was investigated using an atomic absorption spectrometer with Zeeman-effect background correction. The samples were pulverized in a freezer/mill for 13 min, and hair slurries with 1.0 g l -1 for the determination of Cu and Pb, and 5.0 g l -1 for the determination of Cd, respectively, were prepared in three different media: 0.1% v/v Triton X-100, 0.14 mol l -1 HNO 3, and 0.1% v/v of CFA-C, a mixture of tertiary amines. The easiest way to manipulate the hair samples was in CFA-C medium. The optimum pyrolysis and atomization temperatures were established with hair sample slurries spiked with 10 μg l -1 Cd 2+, 30 μg l -1 Pb 2+, and 10 μg l -1 Cu 2+. For Cd and Pb, Pd was used as a chemical modifier, and for Cu no modifier was needed. The analyte addition technique was used for quantification of Cd, Cu, and Pb in hair sample slurries. A reference material (GBW076901) was analyzed, and a paired t-test showed that the results for all elements obtained with the proposed slurry sampling procedure were in agreement at a 95% confidence level with the certified values. The cryogenic grinding was an effective strategy to efficiently pulverize hair samples.

  19. Tailoring Enzyme-Like Activities of Gold Nanoclusters by Polymeric Tertiary Amines for Protecting Neurons Against Oxidative Stress.

    PubMed

    Liu, Ching-Ping; Wu, Te-Haw; Lin, Yu-Lung; Liu, Chia-Yeh; Wang, Sabrina; Lin, Shu-Yi

    2016-08-01

    The cytotoxicity of nanozymes has drawn much attention recently because their peroxidase-like activity can decompose hydrogen peroxide (H2 O2 ) to produce highly toxic hydroxyl radicals (•OH) under acidic conditions. Although catalytic activities of nanozymes are highly associated with their surface properties, little is known about the mechanism underlying the surface coating-mediated enzyme-like activities. Herein, it is reported for the first time that amine-terminated PAMAM dendrimer-entrapped gold nanoclusters (AuNCs-NH2 ) unexpectedly lose their peroxidase-like activity while still retaining their catalase-like activity in physiological conditions. Surprisingly, the methylated form of AuNCs-NH2 (i.e., MAuNCs-N(+) R3 , where R = H or CH3 ) results in a dramatic recovery of the intrinsic peroxidase-like activity while blocking most primary and tertiary amines (1°- and 3°-amines) of dendrimers to form quaternary ammonium ions (4°-amines). However, the hidden peroxidase-like activity is also found in hydroxyl-terminated dendrimer-encapsulated AuNCs (AuNCs-OH, inside backbone with 3°-amines), indicating that 3°-amines are dominant in mediating the peroxidase-like activity. The possible mechanism is further confirmed that the enrichment of polymeric 3°-amines on the surface of dendrimer-encapsulated AuNCs provides sufficient suppression of the critical mediator •OH for the peroxidase-like activity. Finally, it is demonstrated that AuNCs-NH2 with diminished cytotoxicity have great potential for use in primary neuronal protection against oxidative damage. PMID:27346719

  20. Regeneration of lactic and succinic acid-laden basic sorbents by leaching with a volatile base in an organic solvent

    SciTech Connect

    Husson, S.M.; King, C.J. |

    1998-08-01

    Leaching with an organic solution of a volatile base was explored as a method of regenerating tertiary amine and pyridyl sorbents. Experimental data are presented that show that regeneration efficiency correlated with the nonaqueous basicity of the regenerant as measured by the Gutmann donicity scale. Essentially complete regeneration of lactic acid-laden Dowex MWA-1 was achieved when 8--10 mol of trimethylamine were present for every mole of adsorbed acid; adequate (>70%) regeneration was obtained at a 2:1 molar ratio. The resulting trimethylamine-lactic acid complex can be thermally decomposed fully when trimethylamine is employed in an organic solvent instead of in water. A likely cause of the incomplete thermal decomposition of trimethylammonium lactate in previous, water-based systems is the aqueous environment in which the decomposition was performed.

  1. Visible-light-mediated, nitrogen-centered radical amination of tertiary alkyl halides under metal-free conditions to form α-tertiary amines.

    PubMed

    Brueckner, Alexander C; Hancock, Erin N; Anders, Evan J; Tierney, Matthew M; Morgan, Heather R; Scott, Kristina A; Lamar, Angus A

    2016-05-11

    A mild and operationally convenient amino-functionalization of a range of tertiary alkyl halides by reaction with iminoiodinanes (PhI[double bond, length as m-dash]NNs) and I2 has been developed. According to the mechanistic experiments described within, the reaction is speculated to proceed through a light-promoted, N-centered radical pathway involving a N,N-diiodosulfonamide reactive species. This method of direct N-incorporation offers an attractive alternative to the production of α-tertiary amines, a synthetically challenging structural class found in a variety of bioactive molecules. PMID:27113972

  2. Application of 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole in analysis: Fluorescent dyes and unexpected reaction with tertiary amines.

    PubMed

    Annenkov, Vadim V; Verkhozina, Olga N; Shishlyannikova, Tatyana A; Danilovtseva, Elena N

    2015-10-01

    4-Chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) is widely applied as a fluorescent tagging reagent in biochemistry, as a derivatization agent in analytical chemistry, and as a component for design of fluorescent nanoparticles. Four new 7-nitrobenzo-2-oxa-1,3-diazole (NBD)-tagged polyamines containing two to four amine moieties were synthesized and used as an effective tool for staining of siliceous frustules of the diatom algae and spicules of the siliceous sponges, including fossilized samples. An unexpected reaction between NBD-Cl and tertiary amine groups was found, giving rise to NBD-tagged amines with elimination of an alkyl group. The reaction proceeds through the Meisenheimer complex and quaternary salt, which transform to the product by Hofmann reaction (alkene elimination) or nucleophilic substitution (halogenated compound formation). In the case of polyamines, NBD-Cl causes chain scissoring, giving a set of NBD-tagged amines. The found NBD-Cl reaction with tertiary amines must be taken into account when using NBD-Cl and similar activated aromatic systems for amine derivatization in analytical and biochemistry applications. The reaction with polyamines opens the way to libraries of NBD-tagged compounds. PMID:26103595

  3. Inhalation by design: novel tertiary amine muscarinic M₃ receptor antagonists with slow off-rate binding kinetics for inhaled once-daily treatment of chronic obstructive pulmonary disease.

    PubMed

    Glossop, Paul A; Watson, Christine A L; Price, David A; Bunnage, Mark E; Middleton, Donald S; Wood, Anthony; James, Kim; Roberts, Dannielle; Strang, Ross S; Yeadon, Michael; Perros-Huguet, Christelle; Clarke, Nicholas P; Trevethick, Michael A; Machin, Ian; Stuart, Emilio F; Evans, Steven M; Harrison, Anthony C; Fairman, David A; Agoram, Balaji; Burrows, Jane L; Feeder, Neil; Fulton, Craig K; Dillon, Barry R; Entwistle, David A; Spence, Fiona J

    2011-10-13

    A novel tertiary amine series of potent muscarinic M(3) receptor antagonists are described that exhibit potential as inhaled long-acting bronchodilators for the treatment of chronic obstructive pulmonary disease. Geminal dimethyl functionality present in this series of compounds confers very long dissociative half-life (slow off-rate) from the M(3) receptor that mediates very long-lasting smooth muscle relaxation in guinea pig tracheal strips. Optimization of pharmacokinetic properties was achieved by combining rapid oxidative clearance with targeted introduction of a phenolic moiety to secure rapid glucuronidation. Together, these attributes minimize systemic exposure following inhalation, mitigate potential drug-drug interactions, and reduce systemically mediated adverse events. Compound 47 (PF-3635659) is identified as a Phase II clinical candidate from this series with in vivo duration of action studies confirming its potential for once-daily use in humans. PMID:21870878

  4. Hydrogenation of unactivated enamines to tertiary amines: rhodium complexes of fluorinated phosphines give marked improvements in catalytic activity

    PubMed Central

    Tin, Sergey; Fanjul, Tamara

    2015-01-01

    Summary In the hydrogenation of sluggish unactivated enamine substrates, Rh complexes of electron-deficient phosphines are demonstrated to be far more reactive catalysts than those derived from triphenylphosphine. These operate at low catalyst loadings (down to 0.01 mol %) and are able to reduce tetrasubstituted enamines. The use of the sustainable and environmentally benign solvent (R)-limonene for the reaction is also reported with the amine isolated by acid extraction. PMID:26124864

  5. Determination of secondary and tertiary amines as N-nitrosamine precursors in drinking water system using ultra-fast liquid chromatography-tandem mass spectrometry.

    PubMed

    Wu, Qihua; Shi, Honglan; Ma, Yinfa; Adams, Craig; Eichholz, Todd; Timmons, Terry; Jiang, Hua

    2015-01-01

    N-Nitrosamines are potent mutagenic and carcinogenic emerging water disinfection by-products (DBPs). The most effective strategy to control the formation of these DBPs is minimizing their precursors from source water. Secondary and tertiary amines are dominating precursors of N-nitrosamines formation during drinking water disinfection process. Therefore, the screening and removal of these amines in source water are very essential for preventing the formation of N-nitrosamines. A rapid, simple, and sensitive ultrafast liquid chromatography-tandem mass spectrometry (UFLC-MS/MS) method has been developed in this study to determine seven amines, including dimethylamine, ethylmethylamine, diethylamine, dipropylamine, trimethylamine, 3-(dimethylaminomethyl)indole, and 4-dimethylaminoantipyrine, as major precursors of N-nitrosamines in drinking water system. No sample preparation process is needed except a simple filtration. Separation and detection can be achieved in 11 min per sample. The method detection limits of selected amines are ranging from 0.02 μg/L to 1 μg/L except EMA (5 μg/L), and good calibration linearity was achieved. The developed method was applied to determine the selected precursors in source water and drinking water samples collected from Midwest area of the United States. In most of water samples, the concentrations of selected precursors of N-nitrosamines were below their method detection limits. Dimethylamine was detected in some of water samples at the concentration up to 25.4 μg/L. PMID:25281166

  6. Comparison of the efficacy of disinfectants in automated endoscope reprocessors for colonoscopes: tertiary amine compound (Sencron2®) versus ortho-phthalaldehyde (Cidex®OPA)

    PubMed Central

    Seo, Hyun Il; Lee, Dae Sung; Yoon, Eun Mi; Kwon, Min-Jung; Park, Hyosoon; Jung, Yoon Suk; Park, Jung Ho; Sohn, Chong Il

    2016-01-01

    Background/Aims To prevent the transmission of pathogens by endoscopes, following established reprocessing guidelines is critical. An ideal reprocessing step is simple, fast, and inexpensive. Here, we evaluated and compared the efficacy and safety of two disinfectants, a tertiary amine compound (TAC) and ortho-phthalaldehyde (OPA). Methods A total of 100 colonoscopes were randomly reprocessed using two same automated endoscope reprocessors, according to disinfectant. The exposure time was 10 minutes for 0.55% OPA (Cidex® OPA, Johnson & Johnson) and 5 minutes for 4% TAC (Sencron2®, Bab Gencel Pharma & Chemical Ind. Co.). Three culture samples were obtained from each colonoscope after reprocessing. Results A total of nine samples were positive among the 300 culture samples. The positive culture rate was not statistically different between the two groups (4% for OPA and 2% for TAC, P=0.501). There were no incidents related to safety during the study period. Conclusions TAC was non-inferior in terms of reprocessing efficacy to OPA and was safe to use. Therefore, TAC seems to be a good alternative disinfectant with a relatively short exposure time and is also less expensive than OPA. PMID:27175119

  7. Economic combinative solvent and catalytic dewaxing process employing methylisopropyl ketone as the solvent and a silicate-based catalyst

    SciTech Connect

    Stem, S.C.

    1986-11-11

    This patent describes a process for the combinative dewaxing of a lubricating oil having a wax content which comprises: (a) contacting a waxy lubricating oil with a solvent comprising a ketone and an aromatic hydrocarbon selected from the group consisting of benzene, toluene, xylene and cumene in a solvent dewaxing zone, at solvent dewaxing conditions. This produces a partially dewaxed lubricating oil containing the ketone and the aromatic hydrocarbon and a slack wax stream containing hard wax, soft wax containing lubricating oil therewith, ketone, and aromatic hydrocarbon; (b) passing the partially dewaxed lubricating oil and slack wax stream to a first separation zone, and separating therein the partially dewaxed lubricating oil from the slack wax stream; (c) removing the ketone and the aromatic hydrocarbon from the partially dewaxed lubricating oil and contacting the partially dewaxed lubricating oil with a dewaxing catalyst, in a catalytic dewaxing zone, at catalytic dewaxing conditions, to produce a dewaxed lubricating oil; (d) treating, in a second dewaxing zone, the slack wax stream to separate the hard wax from the soft wax containing lubricating oil and the ketone solvent and the aromatic hydrocarbon from the slack wax stream; (e) recycling at least a portion of the ketone and aromatic hydrocarbon from step (d) to the solvent dewaxing zone of step (a) or the second dewaxing zone of step (d); and (f) passing the soft wax containing lubricating oil to a catalytic dewaxing zone to convert the soft wax and to thereby increase the produced quantity of lubricating oil. The improvement described here consists of use of the use of methylisopropyl ketone as the solvent ketone in the solvent dewaxing zone of step (a).

  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. Solvent-Dependent Facile Synthesis of Diaryl Selenides and Biphenols Employing Selenium Dioxide.

    PubMed

    Quell, Thomas; Mirion, Michael; Schollmeyer, Dieter; Dyballa, Katrin M; Franke, Robert; Waldvogel, Siegfried R

    2016-04-01

    Biphenols are important structure motifs for ligand systems in organic catalysis and are therefore included in the category of so-called "privileged ligands". We have developed a new synthetic pathway to construct these structures by the use of selenium dioxide, a stable, powerful, and commercially available oxidizer. Our new, and easy to perform protocol gives rise to biphenols and diaryl selenides depending on the solvent employed. Oxidative treatment of phenols in acetic acid yields the corresponding biphenols, whereas conversion in pyridine results in the preferred formation of diaryl selenides. As a consequence, we were able to isolate a broad scope of novel diaryl selenides, which could act as pincer-like ligands with further applications in organic synthesis or as ligands in transition metal catalysis. PMID:27308222

  10. Efficient CO2 capture by tertiary amine-functionalized ionic liquids through Li+-stabilized zwitterionic adduct formation

    PubMed Central

    Yang, Zhen-Zhen

    2014-01-01

    Summary Highly efficient CO2 absorption was realized through formation of zwitterionic adducts, combining synthetic strategies to ionic liquids (ILs) and coordination. The essence of our strategy is to make use of multidentate cation coordination between Li+ and an organic base. Also PEG-functionalized organic bases were employed to enhance the CO2-philicity. The ILs were reacted with CO2 to form the zwitterionic adduct. Coordination effects between various lithium salts and neutral ligands, as well as the CO2 capacity of the chelated ILs obtained were investigated. For example, the CO2 capacity of PEG150MeBu2N increased steadily from 0.10 to 0.66 (mol CO2 absorbed per mol of base) through the formation of zwitterionic adducts being stabilized by Li+. PMID:25246955

  11. Li-Ion Cells Employing Electrolytes With Methyl Propionate and Ethyl Butyrate Co-Solvents

    NASA Technical Reports Server (NTRS)

    Smart, Marshall C.; Bugga, Ratnakumar V.

    2011-01-01

    Future NASA missions aimed at exploring Mars and the outer planets require rechargeable batteries that can operate at low temperatures to satisfy the requirements of such applications as landers, rovers, and penetrators. A number of terrestrial applications, such as hybrid electric vehicles (HEVs) and electric vehicles (EVs) also require energy storage devices that can operate over a wide temperature range (i.e., -40 to +70 C), while still providing high power capability and long life. Currently, the state-of-the-art lithium-ion system has been demonstrated to operate over a wide range of temperatures (-30 to +40 C); however, the rate capability at the lower temperatures is very poor. These limitations at very low temperatures are due to poor electrolyte conductivity, poor lithium intercalation kinetics over the electrode surface layers, and poor ionic diffusion in the electrode bulk. Two wide-operating-temperature-range electrolytes have been developed based on advances involving lithium hexafluorophosphate-based solutions in carbonate and carbonate + ester solvent blends, which have been further optimized in the context of the technology and targeted applications. The approaches employed include further optimization of electrolytes containing methyl propionate (MP) and ethyl butyrate (EB), which are effective co-solvents, to widen the operating temperature range beyond the baseline systems. Attention was focused on further optimizing ester-based electrolyte formulations that have exhibited the best performance at temperatures ranging from -60 to +60 C, with an emphasis upon improving the rate capability at -20 to -40 C. This was accomplished by increasing electrolyte salt concentration to 1.20M and increasing the ester content to 60 percent by volume to increase the ionic conductivity at low temperatures. Two JPL-developed electrolytes 1.20M LiPF6 in EC+EMC+MP (20:20:60 v/v %) and 1.20M LiPF6 in EC+EMC+EB (20:20:60 v/v %) operate effectively over a wide

  12. Concentration Dependent Speciation and Mass Transport Properties of Switchable Polarity Solvents

    SciTech Connect

    Aaron D. Wilson; Christopher J. Orme

    2014-12-01

    Tertiary amine switchable polarity solvents (SPS) consisting of predominantly water, tertiary amine, and tertiary ammonium and bicarbonate ions were produced at various concentrations for three different amines: N,N-dimethylcyclohexylamine, N,N-dimethyloctylamine, and 1 cyclohexylpiperidine. For all concentrations, physical properties were measured including viscosity, molecular diffusion coefficients, freezing point depression, and density. Based on these measurements a variation on the Mark Houwink equation was developed to predict the viscosity of any tertiary amine SPS as a function of concentration using the amine’s molecular mass. The observed physical properties allowed the identification of solution state speciation of non-osmotic SPS, where the amine to carbonic acid ratio is significantly greater than one. These results indicate that at most concentrations the stoichiometric excess amine is involved in solvating a proton with two amines. The physical properties of osmotic SPS have consistent concentration dependence behavior over a wide range of concentrations; this consistence suggests osmotic pressures based on low concentrations freezing point studies can be reliably extrapolated to higher concentrations.

  13. Injectible bodily prosthetics employing methacrylic copolymer gels

    DOEpatents

    Mallapragada, Surya K.; Anderson, Brian C.

    2007-02-27

    The present invention provides novel block copolymers as structural supplements for injectible bodily prosthetics employed in medical or cosmetic procedures. The invention also includes the use of such block copolymers as nucleus pulposus replacement materials for the treatment of degenerative disc disorders and spinal injuries. The copolymers are constructed by polymerization of a tertiary amine methacrylate with either a (poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) polymer, such as the commercially available Pluronic.RTM. polymers, or a poly(ethylene glycol) methyl ether polymer.

  14. Regeneration strategies of polymers employed in ex-situ remediation of contaminated soil: Bioregeneration versus solvent extraction.

    PubMed

    Mosca Angelucci, Domenica; Tomei, M Concetta

    2015-08-15

    In this study we evaluated the feasibility of two regeneration strategies of contaminated polymers employed for ex-situ soil remediation in a two-step process. Soil decontamination is achieved by sorption of the pollutants on the polymer beads, which are regenerated in a subsequent step. Tested soil was contaminated with a mixture of 4-chlorophenol and pentachlorophenol, and a commercial polymer, Hytrel, has been employed for extraction. Removal efficiencies of the polymer-soil extraction are in the range of 51-97% for a contact time ≤ 24 h. Two polymer regeneration strategies, solvent extraction and biological regeneration (realized in a two-phase partitioning bioreactor), were tested and compared. Performance was assessed in terms of removal rates and efficiencies and an economic analysis based on the operating costs has been performed. Results demonstrated the feasibility of both regeneration strategies, but the bioregeneration was advantageous in that provided the biodegradation of the contaminants desorbed from the polymer. Practically complete removal for 4-chlorophenol and up to 85% biodegradation efficiency for pentachlorophenol were achieved. Instead, in the solvent extraction, a relevant production (184-831 L kg(pol)(-1)) of a highly polluted stream to be treated or disposed of is observed. The cost analysis of the two strategies showed that the bioregeneration is much more convenient with operating costs of ∼12 €/kg(pol) i.e. more than one order of magnitude lower in comparison to ∼233 €/kg(pol) of the solvent extraction. PMID:26074469

  15. Extraction and identification of cyclobutanones from irradiated cheese employing a rapid direct solvent extraction method.

    PubMed

    Tewfik, Ihab

    2008-01-01

    2-Alkylcyclobutanones (cyclobutanones) are accepted as chemical markers for irradiated foods containing lipid. However, current extraction procedures (Soxhlet-florisil chromatography) for the isolation of these markers involve a long and tedious clean-up regime prior to gas chromatography-mass spectrophotometry identification. This paper outlines an alternative isolation and clean-up method for the extraction of cyclobutanones in irradiated Camembert cheese. The newly developed direct solvent extraction method enables the efficient screening of large numbers of food samples and is not as resource intensive as the BS EN 1785:1997 method. Direct solvent extraction appears to be a simple, robust method and has the added advantage of a considerably shorter extraction time for the analysis of foods containing lipid. PMID:19382334

  16. Comparison of two different solvents employed for pressurised fluid extraction of stevioside from Stevia rebaudiana: methanol versus water.

    PubMed

    Pól, Jaroslav; Varadová Ostrá, Elena; Karásek, Pavel; Roth, Michal; Benesová, Karolínka; Kotlaríková, Pavla; Cáslavský, Josef

    2007-08-01

    Pressurised fluid extraction using water or methanol was employed for the extraction of stevioside from Stevia rebaudiana Bertoni. The extraction method was optimised in terms of temperature and duration of the static or the dynamic step. Extracts were analysed by liquid chromatography followed by UV and mass-spectrometric (MS) detections. Thermal degradation of stevioside was the same in both solvents within the range 70-160 degrees C. Methanol showed better extraction ability for isolation of stevioside from Stevia rebaudiana leaves than water within the range 110-160 degrees C. However, water represents the green alternative to methanol. The limit of detection of stevioside in the extract analysed was 30 ng for UV detection and 2 ng for MS detection. PMID:17594081

  17. Photocatalytic splitting of CS2 to S8 and a carbon-sulfur polymer catalyzed by a bimetallic ruthenium(II) compound with a tertiary amine binding site: toward photocatalytic splitting of CO2?

    PubMed

    Livanov, Konstantin; Madhu, Vedichi; Balaraman, Ekambaram; Shimon, Linda J W; Diskin-Posner, Yael; Neumann, Ronny

    2011-11-21

    The catalytic photocleavage of CS(2) to S(8) and a (C(x)S(y))(n) polymer with visible light using a dinuclear ruthenium(II) compound with a bipyridine units for photoactivity and a vicinal tertiary amine binding site for CS(2) activation was studied. The catalyst was characterized by X-ray diffraction, (1)H NMR, and (13)C NMR, ESI-MS and elemental analysis. CS(2) photocleavage was significant (240 turnovers, 20 h) to yield isolable S(8) and a (C(x)S(y))(n) polymer. A mononuclear catalyst or one without an amine binding site showed significantly less activity. XPS of the (C(x)S(y))(n) polymer showed a carbon/sulfur ratio ∼1.5-1.6 indicating that in part both C-S bonds of CS(2) had been cleaved. Catalyst was also included within the polymer. The absence of peaks in the (1)H NMR verified the (C(x)S(y))(n) nature of the polymer, while (13)C NMR and IR indicated that the polymer had multiple types of C-S and C-C bonds. PMID:22029376

  18. Liquefaction process wherein solvents derived from the material liquefied and containing increased concentrations of donor species are employed

    DOEpatents

    Fant, B. T.; Miller, John D.; Ryan, D. F.

    1982-01-01

    An improved process for the liquefaction of solid carbonaceous materials wherein a solvent or diluent derived from the solid carbonaceous material being liquefied is used to form a slurry of the solid carbonaceous material and wherein the solvent or diluent comprises from about 65 to about 85 wt. % hydroaromatic components. The solvent is prepared by first separating a solvent or diluent distillate fraction from the liquefaction product, subjecting this distillate fraction to hydrogenation and then extracting the naphthenic components from the hydrogenated product. The extracted naphthenic components are then dehydrogenated and hydrotreated to produce additional hydroaromatic components. These components are combined with the solvent or diluent distillate fraction. The solvent may also contain hydroaromatic constituents prepared by extracting naphthenic components from a heavy naphtha, dehydrogenating the same and then hydrotreating the dehydrogenated product. When the amount of solvent produced in this manner exceeds that required for steady state operation of the liquefaction process a portion of the solvent or diluent distillated fraction will be withdrawn as product.

  19. Switchable-Hydrophilicity Solvents for Product Isolation and Catalyst Recycling in Organocatalysis.

    PubMed

    Großeheilmann, Julia; Vanderveen, Jesse R; Jessop, Philip G; Kragl, Udo

    2016-04-01

    Switchable-hydrophilicity solvents (SHSs) are solvents that can switch reversibly between a water-miscible state to a state that forms a biphasic mixture with water. In this case study, SHSs have been studied for easy product/catalyst separation as well as catalyst recycling. A series of tertiary amine SHSs have been identified for the extraction of the hydrophilic product from the postreaction mixture. Here, we determined high extraction efficiencies for the product (>84%) and low extraction rates for the catalyst (<0.1%). With the catalyst recycling experiments, we isolated the product in high purity (>98%) without further purification steps. At the same time, the catalyst was reused without any loss of activity (>91% enantiomeric excess, >99% yield) four times. Furthermore, we optimized the extraction efficiency by working with a microextractor. In addition, with the use of a falling-film microreactor, we obtained the product with high enantioselectivity by working at ambient conditions. PMID:26893152

  20. CO{sub 2} capture in flue gas: Semiempirical approach to select a potential physical solvent

    SciTech Connect

    Gwinner, B.; Roizard, D.; Lapicque, F.; Favre, E.; Cadours, R.; Boucot, P.; Carrette, P.L.

    2006-07-05

    The reported work aims at proposing a method to select potential physical solvents for CO{sub 2} absorption in flue gas. A parametric approach based on solubility data available in the open literature is engaged. It appears that CO{sub 2} capture with physical solvents is dominated by two fundamental aspects. On one hand, solvent-solvent interactions, characterized by the Hildebrand solubility parameter, have to be minimized so as to facilitate CO{sub 2} incorporation into the solvent. On the other hand, CO{sub 2}-solvent interactions, which can be estimated by ab initio calculations, have to be maximized in order to allow good cohesion between CO{sub 2} and the solvent molecules. Considering these two requirements, several types of solvents are highlighted, namely, ethers, esters, ketones, tertiary amines, and alkyl phosphates. This parametric approach differs notably from similar works about another acid gas, SO{sub 2}, and the forthcoming differences are discussed. Some mechanistic considerations are also given about the critical problems of CO{sub 2}/N{sub 2} selectivity.

  1. Cytotoxicity evaluation of anionic nanoliposomes and nanolipoplexes prepared by the heating method without employing volatile solvents and detergents.

    PubMed

    Mozafari, M R; Reed, C J; Rostron, C

    2007-03-01

    Submicron lipid vesicles (nanoliposomes) are being used as carriers of bioactive compounds. In addition, complexes of nanoliposomes and nucleic acids (nanolipoplexes) are promising tools for the treatment of cancer, and viral and genetic disorders. Toxicity of some of these formulations, however, still remains a concern in their clinical utilisation. To address this problem, anionic liposomes were prepared by two different techniques, the conventional thin-film method, and the heating method (HM), in which no volatile organic solvent or detergent is used. An anionic nanolipoplex was constructed by incorporating plasmid DNA (pcDNA3.1/His B/lacZ) into the HM-nanoliposomes by the mediation of calcium. The toxicity of the nanoliposomes, with and without plasmid and Ca2+, was assessed using a human bronchial epithelial cell line (16HBE14o-) in the presence of serum. Cytotoxicity evaluations performed by two different assays (i.e. NRU and MTT) indicated that HM-nanoliposomes were completely non-toxic in the cell-line tested, whereas conventional liposomes revealed significant levels of toxicity. This may be due to the presence of trace amounts of chloroform and/or methanol applied during their preparation. Similar results were obtained for different sizes of lipid vesicles (prepared by 100 nm and 400 nm pore-size filters). In addition, it was observed that incorporation of DNA (15 microg/ 285 microg lipid) and Ca2+ (50 mM) to the nanoliposomes did not have any effect on their cytotoxicities. These findings indicate that the HM-liposomes have great potential as non-toxic delivery vehicles in human gene therapy and drug delivery applications while liposomes made using organic solvents should be used with caution. PMID:17416197

  2. Counter-current chromatography for the separation of terpenoids: a comprehensive review with respect to the solvent systems employed.

    PubMed

    Skalicka-Woźniak, Krystyna; Garrard, Ian

    2014-01-01

    Natural products extracts are commonly highly complex mixtures of active compounds and consequently their purification becomes a particularly challenging task. The development of a purification protocol to extract a single active component from the many hundreds that are often present in the mixture is something that can take months or even years to achieve, thus it is important for the natural product chemist to have, at their disposal, a broad range of diverse purification techniques. Counter-current chromatography (CCC) is one such separation technique utilising two immiscible phases, one as the stationary phase (retained in a spinning coil by centrifugal forces) and the second as the mobile phase. The method benefits from a number of advantages when compared with the more traditional liquid-solid separation methods, such as no irreversible adsorption, total recovery of the injected sample, minimal tailing of peaks, low risk of sample denaturation, the ability to accept particulates, and a low solvent consumption. The selection of an appropriate two-phase solvent system is critical to the running of CCC since this is both the mobile and the stationary phase of the system. However, this is also by far the most time consuming aspect of the technique and the one that most inhibits its general take-up. In recent years, numerous natural product purifications have been published using CCC from almost every country across the globe. Many of these papers are devoted to terpenoids-one of the most diverse groups. Naturally occurring terpenoids provide opportunities to discover new drugs but many of them are available at very low levels in nature and a huge number of them still remain unexplored. The collective knowledge on performing successful CCC separations of terpenoids has been gathered and reviewed by the authors, in order to create a comprehensive document that will be of great assistance in performing future purifications. PMID:24899873

  3. Water based on a molecular model behaves like a hard-sphere solvent for a nonpolar solute when the reference interaction site model and related theories are employed.

    PubMed

    Hayashi, Tomohiko; Oshima, Hiraku; Harano, Yuichi; Kinoshita, Masahiro

    2016-09-01

    For neutral hard-sphere solutes, we compare the reduced density profile of water around a solute g(r), solvation free energy μ, energy U, and entropy S under the isochoric condition predicted by the two theories: dielectrically consistent reference interaction site model (DRISM) and angle-dependent integral equation (ADIE) theories. A molecular model for water pertinent to each theory is adopted. The hypernetted-chain (HNC) closure is employed in the ADIE theory, and the HNC and Kovalenko-Hirata (K-H) closures are tested in the DRISM theory. We also calculate g(r), U, S, and μ of the same solute in a hard-sphere solvent whose molecular diameter and number density are set at those of water, in which case the radial-symmetric integral equation (RSIE) theory is employed. The dependences of μ, U, and S on the excluded volume and solvent-accessible surface area are analyzed using the morphometric approach (MA). The results from the ADIE theory are in by far better agreement with those from computer simulations available for g(r), U, and μ. For the DRISM theory, g(r) in the vicinity of the solute is quite high and becomes progressively higher as the solute diameter d U increases. By contrast, for the ADIE theory, it is much lower and becomes further lower as d U increases. Due to unphysically positive U and significantly larger |S|, μ from the DRISM theory becomes too high. It is interesting that μ, U, and S from the K-H closure are worse than those from the HNC closure. Overall, the results from the DRISM theory with a molecular model for water are quite similar to those from the RSIE theory with the hard-sphere solvent. Based on the results of the MA analysis, we comparatively discuss the different theoretical methods for cases where they are applied to studies on the solvation of a protein. PMID:27366886

  4. Water based on a molecular model behaves like a hard-sphere solvent for a nonpolar solute when the reference interaction site model and related theories are employed

    NASA Astrophysics Data System (ADS)

    Hayashi, Tomohiko; Oshima, Hiraku; Harano, Yuichi; Kinoshita, Masahiro

    2016-09-01

    For neutral hard-sphere solutes, we compare the reduced density profile of water around a solute g(r), solvation free energy μ, energy U, and entropy S under the isochoric condition predicted by the two theories: dielectrically consistent reference interaction site model (DRISM) and angle-dependent integral equation (ADIE) theories. A molecular model for water pertinent to each theory is adopted. The hypernetted-chain (HNC) closure is employed in the ADIE theory, and the HNC and Kovalenko–Hirata (K–H) closures are tested in the DRISM theory. We also calculate g(r), U, S, and μ of the same solute in a hard-sphere solvent whose molecular diameter and number density are set at those of water, in which case the radial-symmetric integral equation (RSIE) theory is employed. The dependences of μ, U, and S on the excluded volume and solvent-accessible surface area are analyzed using the morphometric approach (MA). The results from the ADIE theory are in by far better agreement with those from computer simulations available for g(r), U, and μ. For the DRISM theory, g(r) in the vicinity of the solute is quite high and becomes progressively higher as the solute diameter d U increases. By contrast, for the ADIE theory, it is much lower and becomes further lower as d U increases. Due to unphysically positive U and significantly larger |S|, μ from the DRISM theory becomes too high. It is interesting that μ, U, and S from the K–H closure are worse than those from the HNC closure. Overall, the results from the DRISM theory with a molecular model for water are quite similar to those from the RSIE theory with the hard-sphere solvent. Based on the results of the MA analysis, we comparatively discuss the different theoretical methods for cases where they are applied to studies on the solvation of a protein.

  5. SWITCHABLE POLARITY SOLVENTS AS DRAW SOLUTES FOR FORWARD OSMOSIS

    SciTech Connect

    Frederick F. Stewart; Mark L. Stone; Aaron D. Wilson; Cathy Rae

    2013-03-01

    Switchable polarity solvents (SPS), mixtures of carbon dioxide, water, and tertiary amines, are presented as viable forward osmosis (FO) draw solutes allowing a novel SPS FO process. In this study substantial osmotic strengths of SPS are measured with freezing point osmometry and were demonstrated to induce competitive ?uxes at high salt concentrations on a laboratory-scale FO unit utilizing a ?at sheet cellulose triacetate (CTA) membrane. Under the experimental conditions the SPS degrades the CTA membrane; however experiments with polyamide reverse osmosis (RO) membranes display stability towards SPS. Once the draw is diluted the major fraction of the switchable polarity solvent can be mechanically separated from the puri?ed water after polar to nonpolar phase shift induced by introduction of 1 atm carbon dioxide to 1 atm of air or nitrogen with mild heating. Trace amounts of SPS can be removed from the separated water with RO in a process that avoids solution concentration polarization. The separated nonpolar phase can be regenerated to a full strength draw and recycled with the re-addition of 1 atm of carbon dioxide.

  6. Dual solvent refining process

    SciTech Connect

    Woodle, R.A.

    1982-04-20

    A dual solvent refining process is claimed for solvent refining petroleum based lubricating oil stocks with n-methyl-2-pyrrolidone as selective solvent for aromatic oils wherein a highly paraffinic oil having a narrow boiling range approximating the boiling point of n-methyl-2-pyrrolidone is employed as a backwash solvent. The process of the invention results in an increased yield of refined lubricating oil stock of a predetermined quality and simplifies separation of the solvents from the extract and raffinate oil fractions.

  7. Labelling of the solvent DMSO as side reaction of methylations with n.c.a. [11C]CH3I.

    PubMed

    Klein, A T; Holschbach, M

    2001-09-01

    Competing labelling of solvent dimethyl sulfoxide (DMSO) can occur during the 11C-methylation of amine precursors. A kinetic analysis of the methylation reaction of DMSO with n.c.a. [11C]CH3I was performed at 120 degrees C resulting in rate constants. The rate constant for the formation of the intermediate, methylated DMSO ([11C]DMSO-M), is compared to the reaction of [11C]CH3I with two tertiary amines, namely Dexetimide and Desmethyloxotremorine-M. The specific activity of the labelled product is reduced due to partial 12C-methylation of the precursor amines by [11C]DMSO-M in cases of significant DMSO labelling as side reaction. PMID:11515652

  8. Regioselective, Solvent- and Metal-Free Chalcogenation of Imidazo[1,2-a]pyridines by Employing I2 /DMSO as the Catalytic Oxidation System.

    PubMed

    Rafique, Jamal; Saba, Sumbal; Rosário, Alisson R; Braga, Antonio L

    2016-08-01

    Highly efficient molecular-iodine-catalyzed chalcogenations (S and Se) of imidazo[1,2-a]pyridines were achieved by using diorganoyl dichalcogenides under solvent-free conditions. This approach afforded the desired products that had been chalcogenated regioselectively at the C3 position in up to 96 % yield by using DMSO as an oxidant, in the absence of a metal catalyst, and under an inert atmosphere. This mild, green approach allowed the preparation of different types of chalcogenated imidazo[1,2-a]pyridines with structural diversity. Furthermore, the current protocol was also extended to other N-heterocyclic cores. PMID:27388454

  9. Halogen- and Hydrogen-Bonded Salts and Co-crystals Formed from 4-Halo-2,3,5,6-tetrafluorophenol and Cyclic Secondary and Tertiary Amines: Orthogonal and Non-orthogonal Halogen and Hydrogen Bonding, and Synthetic Analogues of Halogen-Bonded Biological Systems

    PubMed Central

    Takemura, Akihiro; McAllister, Linda J; Hart, Sam; Pridmore, Natalie E; Karadakov, Peter B; Whitwood, Adrian C; Bruce, Duncan W

    2014-01-01

    Co-crystallisation of, in particular, 4-iodotetrafluorophenol with a series of secondary and tertiary cyclic amines results in deprotonation of the phenol and formation of the corresponding ammonium phenate. Careful examination of the X-ray single-crystal structures shows that the phenate anion develops a C=O double bond and that the C–C bond lengths in the ring suggest a Meissenheimer-like delocalisation. This delocalisation is supported by the geometry of the phenate anion optimised at the MP2(Full) level of theory within the aug-cc-pVDZ basis (aug-cc-pVDZ-PP on I) and by natural bond orbital (NBO) analyses. With sp2 hybridisation at the phenate oxygen atom, there is strong preference for the formation of two non-covalent interactions with the oxygen sp2 lone pairs and, in the case of secondary amines, this occurs through hydrogen bonding to the ammonium hydrogen atoms. However, where tertiary amines are concerned, there are insufficient hydrogen atoms available and so an electrophilic iodine atom from a neighbouring 4-iodotetrafluorophenate group forms an I⋅⋅⋅O halogen bond to give the second interaction. However, in some co-crystals with secondary amines, it is also found that in addition to the two hydrogen bonds forming with the phenate oxygen sp2 lone pairs, there is an additional intermolecular I⋅⋅⋅O halogen bond in which the electrophilic iodine atom interacts with the C=O π-system. All attempts to reproduce this behaviour with 4-bromotetrafluorophenol were unsuccessful. These structural motifs are significant as they reproduce extremely well, in low-molar-mass synthetic systems, motifs found by Ho and co-workers when examining halogen-bonding interactions in biological systems. The analogy is cemented through the structures of co-crystals of 1,4-diiodotetrafluorobenzene with acetamide and with N-methylbenzamide, which, as designed models, demonstrate the orthogonality of hydrogen and halogen bonding proposed in Ho’s biological study. PMID

  10. Secondary organic aerosol formation of primary, secondary and tertiary Amines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Amines have been widely identified in ambient aerosol in both urban and rural environments and they are potential precursors for formation of nitrogen-containing secondary organic aerosols (SOA). However, the role of amines in SOA formation has not been well studied. In this wrok, we use UC-Riversid...

  11. SOLVENT EXTRACTION PROCESS

    DOEpatents

    Jonke, A.A.

    1957-10-01

    In improved solvent extraction process is described for the extraction of metal values from highly dilute aqueous solutions. The process comprises contacting an aqueous solution with an organic substantially water-immiscible solvent, whereby metal values are taken up by a solvent extract phase; scrubbing the solvent extract phase with an aqueous scrubbing solution; separating an aqueous solution from the scrubbed solvent extract phase; and contacting the scrubbed solvent phase with an aqueous medium whereby the extracted metal values are removed from the solvent phase and taken up by said medium to form a strip solution containing said metal values, the aqueous scrubbing solution being a mixture of strip solution and an aqueous solution which contains mineral acids anions and is free of the metal values. The process is particularly effective for purifying uranium, where one starts with impure aqueous uranyl nitrate, extracts with tributyl phosphate dissolved in carbon tetrachloride, scrubs with aqueous nitric acid and employs water to strip the uranium from the scrubbed organic phase.

  12. Solvent substitution

    SciTech Connect

    Not Available

    1990-01-01

    The DOE Environmental Restoration and Waste Management Office of Technology Development and the Air Force Engineering and Services Center convened the First Annual International Workshop on Solvent Substitution on December 4--7, 1990. The primary objectives of this joint effort were to share information and ideas among attendees in order to enhance the development and implementation of required new technologies for the elimination of pollutants associated with industrial use of hazardous and toxic solvents; and to aid in accelerating collaborative efforts and technology transfer between government and industry for solvent substitution. There were workshop sessions focusing on Alternative Technologies, Alternative Solvents, Recovery/Recycling, Low VOC Materials and Treatment for Environmentally Safe Disposal. The 35 invited papers presented covered a wide range of solvent substitution activities including: hardware and weapons production and maintenance, paint stripping, coating applications, printed circuit boards, metal cleaning, metal finishing, manufacturing, compliance monitoring and process control monitoring. This publication includes the majority of these presentations. In addition, in order to further facilitate information exchange and technology transfer, the US Air Force and DOE solicited additional papers under a general Call for Papers.'' These papers, which underwent review and final selection by a peer review committee, are also included in this combined Proceedings/Compendium. For those involved in handling, using or managing hazardous and toxic solvents, this document should prove to be a valuable resource, providing the most up-to-date information on current technologies and practices in solvent substitution. Individual papers are abstracted separated.

  13. Solvent Blending Strategy to Upgrade MCU CSSX Solvent to Equivalent Next-Generation CSSX Solvent

    SciTech Connect

    Delmau, Laetitia Helene; Moyer, Bruce A

    2012-12-01

    The results of the present study have validated an equal-volume blending strategy for upgrading freshly prepared CSSX solvent to a blended solvent functionally equivalent to NG-CSSX solvent. It is shown that blending fresh CSSX solvent as currently used in MCU with an equal volume of an NG-CSSX solvent concentrate of appropriate composition yields a blended solvent composition (46.5 mM of MaxCalix, 3.5 mM of BOBCalixC6, 0.5 M of Cs-7SB, 3 mM of guanidine suppressor, and 1.5 mM of TOA in Isopar L) that exhibits equivalent batch ESS performance to that of the NG-CSSX solvent containing 50 mM of MaxCalix, 0.5 M of Cs-7SB, and 3 mM of guanidine suppressor in Isopar L. The solvent blend composition is robust to third-phase formation. Results also show that a blend containing up to 60% v/v of CSSX solvent could be accommodated with minimal risk. Extraction and density data for the effect of solvent concentration mimicking diluent evaporation or over-dilution of the equal-volume blended solvent are also given, providing input for setting operational limits. Given that the experiments employed all pristine chemicals, the results do not qualify a blended solvent starting with actual used MCU solvent, which can be expected to have undergone some degree of degradation. Consequently, further work should be considered to evaluate this risk and implement appropriate remediation if needed.

  14. Solvent Production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This article describes production of butanol [acetone-butanol-ethanol, (also called AB or ABE or solvent)] by fermentation using both traditional and current technologies. AB production from agricultural commodities such as corn and molasses was an important historical fermentation. Unfortunately,...

  15. Novel Regenerated Solvent Extraction Processes for the Recovery of Carboxylic Acids or Ammonia from Aqueous Solutions Part I. Regeneration of Amine-Carboxylic Acid Extracts

    SciTech Connect

    Poole, L.J.; King, C.J.

    1990-03-01

    Two novel regenerated solvent extraction processes are examined. The first process has the potential to reduce the energy costs inherent in the recovery of low-volatility carboxylic acids from dilute aqueous solutions. The second process has the potential for reducing the energy costs required for separate recovery of ammonia and acid gases (e.g. CO{sub 2} and H{sub 2}S) from industrial sour waters. The recovery of carboxylic acids from dilute aqueous solution can be achieved by extraction with tertiary amines. An approach for regeneration and product recovery from such extracts is to back-extract the carboxylic acid with a water-soluble, volatile tertiary amine, such as trimethylamine. The resulting trimethylammonium carboxylate solution can be concentrated and thermally decomposed, yielding the product acid and the volatile amine for recycle. Experimental work was performed with lactic acid, succinic acid, and fumaric acid. Equilibrium data show near-stoichiometric recovery of the carboxylic acids from an organic solution of Alamine 336 into aqueous solutions of trimethylamine. For fumaric and succinic acids, partial evaporation of the aqueous back extract decomposes the carboxylate and yields the acid product in crystalline form. The decomposition of aqueous solutions of trimethylammonium lactates was not carried out to completion, due to the high water solubility of lactic acid and the tendency of the acid to self-associate. The separate recovery of ammonia and acid gases from sour waters can be achieved by combining steam-stripping of the acid gases with simultaneous removal of ammonia by extraction with a liquid cation exchanger. The use of di-2,4,4-trimethylpentyl phosphinic acid as the liquid cation exchanger is explored in this work. Batch extraction experiments were carried out to measure the equilibrium distribution ratio of ammonia between an aqueous buffer solution and an organic solution of the phosphinic acid (0.2N) in Norpar 12. The concentration

  16. Novel Regenerated Solvent Extraction Processes for the Recovery of Carboxylic Acids or Ammonia from Aqueous Solutions Part II. Recovery of Ammonia from Sour Waters

    SciTech Connect

    Poole, L.J.; King, C.J.

    1990-03-01

    Two novel regenerated solvent extraction processes are examined. The first process has the potential to reduce the energy costs inherent in the recovery of low-volatility carboxylic acids from dilute aqueous solutions. The second process has the potential for reducing the energy costs required for separate recovery of ammonia and acid gases (e.g. CO{sub 2} and H{sub 2}S) from industrial sour waters. The recovery of carboxylic acids from dilute aqueous solution can be achieved by extraction with tertiary amines. An approach for regeneration and product recovery from such extracts is to back-extract the carboxylic acid with a water-soluble, volatile tertiary amine, such as trimethylamine. The resulting trimethylammonium carboxylate solution can be concentrated and thermally decomposed, yielding the product acid and the volatile amine for recycle. Experimental work was performed with lactic acid, SUCCiOlC acid, and fumaric acid. Equilibrium data show near-stoichiometric recovery of the carboxylic acids from an organic solution of Alamine 336 into aqueous solutions of trimethylamine. For fumaric and succinic acids, partial evaporation of the aqueous back extract decomposes the carboxylate and yields the acid product in crystalline form. The decomposition of aqueous solutions of trimethylammonium lactates was not carried out to completion, due to the high water solubility of lactic acid and the tendency of the acid to self-associate. The separate recovery of ammonia and acid gases from sour waters can be achieved by combining steam-stripping of the acid gases with simultaneous removal of ammonia by extraction with a liquid cation exchanger. The use of di-2,4,4-trimethylpentyl phosphinic acid as the liquid cation exchanger is explored in this work. Batch extraction experiments were carried out to measure the equilibrium distribution ratio of ammonia between an aqueous buffer solution and an organic solution of the phosphinic acid (0.2N) in Norpar 12. The concentration

  17. Lube solvents no threat to waste treatment

    SciTech Connect

    Rowe, E.H.; Tullos, L.F.

    1980-10-01

    Biological treatment of reasonable loads of lubricating oil extraction solvents should pose no problems for a diversified refinery treatment system. Activated sludge, aerated lagoons, or oxidation ponds are the most frequently employed biological processes for treating such wastes. Rates of solvent degradation are reported for phenol and furfural.

  18. Solvent effects on ozonolysis reaction intermediates

    NASA Astrophysics Data System (ADS)

    del Rio, Emma; Aplincourt, Philippe; Ruiz-López, Manuel F.

    1997-12-01

    Solvent effects on relative stability, electronic and molecular structure of ozonolysis reaction intermediates are analyzed with the help of ab initio MP2/6-31+G ** calculations. A continuum model is employed to account for solute-solvent electrostatic interactions. The results show that there are large effects on the structure and relative stability of carbonyl oxide by substantially favoring its zwitterionic character. A complex formed by carbonyl oxide and formaldehyde is shown to be stable in the gas phase and in solution. This complex can be involved in solvent cage reactions leading to secondary ozonides. Thermodynamically, primary ozonide decomposition is favored by the solvent.

  19. Solvent Extraction External Radiation Stability Testing

    SciTech Connect

    Peterson, R.A.

    2001-01-05

    Personnel irradiated a number of samples of calixarene-based solvent. Analysis of these samples indicated that measurable loss of the calixarene occurred at very high doses (-16 Mrad). No measurable loss of the Cs-7SB modifier occurred at equivalent doses. The primary degradation product, 4-sec-butylphenol, observed during analysis of the samples came from degradation of the modifier. Also, TOA proved more susceptible to damage than the other components of the solvent. The total degradation of the solvent proved relatively minor. The consistent solvent performance, as indicated by the measured D Cs values, after exposure at high total doses serves as evidence of the relatively low degree of degradation of the solvent components. Additional tests employing internal irradiation of solvents with both simulants and SRS tank waste will be completed by the end of March 2001 to provide confirmation of the results presented herein.

  20. Rational solvent selection for cooling crystallizations

    SciTech Connect

    Nass, K.K. . Chemicals Development Div.)

    1994-06-01

    The development of a successful crystallization process for purification and isolation of an organic compound requires the selection of a suitable solvent or solvent mixture; to date, no logical method has been established for determining the best solvent combination. The process chemist or engineer often employs a trial-and-error procedure to identify an appropriate solvent system, the success of which is dependent on experience and intuition. This paper describes a strategy for choosing crystallization solvents based upon equilibrium limits. The approach utilizes a group-contribution method (UNIFAC) to predict a value for the activity coefficient of the solute in a given solvent system at the saturation point. This value is then used to calculate the solubility of the solute at a high'' temperature and a low'' temperature. The resulting solubility values determine the maximum theoretical yield for the process. Both quantities are used to rank order solvents and/or their mixtures relative to one another according to their solvent power and potential process yield. Several examples illustrating the successful application of this method are described, and potential improvements to the algorithm are discussed. Implementation of this strategy will reduce product cycle time, minimize solvent usage, and allow identification of cheaper solvent alternatives.

  1. 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.

  2. 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.

  3. METHOD FOR SOLVENT-ISOSTATIC PRESSING

    DOEpatents

    Archibald, P.B.

    1962-09-18

    This invention provides a method for producing densely compacted bodies having relatively large dimensions. The method comprises the addition of a small quantity of a suitable solvent to a powder which is to be compacted. The solvent- moistened powder is placed inside a flexible bag, and the bag is suspended in an isostatic press. The solvent is squeezed out of the powder by the isostatic pressure, and the resulting compacted body is recovered. The presence of the solvent markedly decreases the proportion of void space in the powder, thereby resulting in a denser, more homogeneous compact. Another effect of the solvent is that it allows the isostatic pressing operation to be conducted at substantially lower pressures than are conventionally employed. (AEC)

  4. NEPTUNIUM SOLVENT EXTRACTION PROCESS

    DOEpatents

    Dawson, L.R.; Fields, P.R.

    1959-10-01

    The separation of neptunium from an aqueous solution by solvent extraction and the extraction of neptunium from the solvent solution are described. Neptunium is separated from an aqueous solution containing tetravalent or hexavalent neptunium nitrate, nitric acid, and a nitrate salting out agent, such as sodium nitrate, by contacting the solution with an organic solvent such as diethyl ether. Subsequently, the neptunium nitrate is extracted from the organic solvent extract phase with water.

  5. Solvent refining process

    SciTech Connect

    Mead, T.C.; Sequeira, A.J.; Smith, B.F.

    1981-10-13

    An improved process is described for solvent refining lubricating oil base stocks from petroleum fractions containing both aromatic and nonaromatic constituents. The process utilizes n-methyl-2-pyrrolidone as a selective solvent for aromatic hydrocarbons wherein the refined oil fraction and the extract fraction are freed of final traces of solvent by stripping with gaseous ammonia. The process has several advantages over conventional processes including a savings in energy required for the solvent refining process, and reduced corrosion of the process equipment.

  6. Calculating the binding free energies of charged species based on explicit-solvent simulations employing lattice-sum methods: An accurate correction scheme for electrostatic finite-size effects

    PubMed Central

    Rocklin, Gabriel J.; Mobley, David L.; Dill, Ken A.; Hünenberger, Philippe H.

    2013-01-01

    calculations for a given system, its dependence on the box size being analytical. The latter scheme also provides insight into the physical origin of the finite-size effects. These two schemes also encompass a correction for discrete solvent effects that persists even in the limit of infinite box sizes. Application of either scheme essentially eliminates the size dependence of the corrected charging free energies (maximal deviation of 1.5 kJ mol−1). Because it is simple to apply, the analytical correction scheme offers a general solution to the problem of finite-size effects in free-energy calculations involving charged solutes, as encountered in calculations concerning, e.g., protein-ligand binding, biomolecular association, residue mutation, pKa and redox potential estimation, substrate transformation, solvation, and solvent-solvent partitioning. PMID:24320250

  7. Calculating the binding free energies of charged species based on explicit-solvent simulations employing lattice-sum methods: An accurate correction scheme for electrostatic finite-size effects

    SciTech Connect

    Rocklin, Gabriel J.; Mobley, David L.; Dill, Ken A.; Hünenberger, Philippe H.

    2013-11-14

    -periodic PB calculations for a given system, its dependence on the box size being analytical. The latter scheme also provides insight into the physical origin of the finite-size effects. These two schemes also encompass a correction for discrete solvent effects that persists even in the limit of infinite box sizes. Application of either scheme essentially eliminates the size dependence of the corrected charging free energies (maximal deviation of 1.5 kJ mol{sup −1}). Because it is simple to apply, the analytical correction scheme offers a general solution to the problem of finite-size effects in free-energy calculations involving charged solutes, as encountered in calculations concerning, e.g., protein-ligand binding, biomolecular association, residue mutation, pK{sub a} and redox potential estimation, substrate transformation, solvation, and solvent-solvent partitioning.

  8. Environmental Impacts on Nuclear Reprocessing Solvents

    NASA Astrophysics Data System (ADS)

    Gillens, A. R.; Fessenden, J. E.

    2009-12-01

    Nuclear tests have been employed ever since the first nuclear explosion in Alamogordo, NM during the mid-1940s. Nuclear weapons pose a threat to civil society and result in extensive biological (medical) damages. For this reason, treaties banning nuclear tests and weapons have been employed since the 1960s to cease proliferation of weapons. However, as nuclear tests continue in secrecy and actinides, such as plutonium and uranium, are eligible for theft, nuclear forensics is needed to prevent weapons proliferation. In this study, solvents [tributyl phosphate (TBP), dodecane, decanol] used in reprocessing spent nuclear fuel are analyzed using an isotope ratio mass spectrometer, which provides indisputable evidence in identifying the operation in which solvents were used. Solvent samples are observed under variable conditions in the laboratory for different time periods. It is assumed that their carbon isotope values (δ13C) will become more positive (shift heavy) with time. It is found that the solvents are hygroscopic. TBP leaves the most robust signature compared to the other solvents studied and the isotope values for all solvents under all conditions become more positive with time. This study serves as primary research in understanding how solvents behave under variable conditions in the laboratory and how this could be translated to the environment in fate and transport studies.

  9. Solvents and sustainable chemistry

    PubMed Central

    Welton, Tom

    2015-01-01

    Solvents are widely recognized to be of great environmental concern. The reduction of their use is one of the most important aims of green chemistry. In addition to this, the appropriate selection of solvent for a process can greatly improve the sustainability of a chemical production process. There has also been extensive research into the application of so-called green solvents, such as ionic liquids and supercritical fluids. However, most examples of solvent technologies that give improved sustainability come from the application of well-established solvents. It is also apparent that the successful implementation of environmentally sustainable processes must be accompanied by improvements in commercial performance. PMID:26730217

  10. Solvent recycle/recovery

    SciTech Connect

    Paffhausen, M.W.; Smith, D.L.; Ugaki, S.N.

    1990-09-01

    This report describes Phase I of the Solvent Recycle/Recovery Task of the DOE Chlorinated Solvent Substitution Program for the US Air Force by the Idaho National Engineering Laboratory, EG G Idaho, Inc., through the US Department of Energy, Idaho Operations Office. The purpose of the task is to identify and test recovery and recycling technologies for proposed substitution solvents identified by the Biodegradable Solvent Substitution Program and the Alternative Solvents/Technologies for Paint Stripping Program with the overall objective of minimizing hazardous wastes. A literature search to identify recycle/recovery technologies and initial distillation studies has been conducted. 4 refs.

  11. Employment Training.

    ERIC Educational Resources Information Center

    Further Education Unit, London (England).

    This document reviews the progress of the Employment Training (ET) initiative for employed adults in Great Britain. The document begins by explaining the changing context in which the project is operating, which includes a downgrading of the alternatives to ET, increased participation in ET, and increased employer involvement in ET. The response…

  12. Phase separation phenomena of polysulfone/solvent/organic nonsolvent and polyethersulfone/solvent/organic nonsolvent systems

    SciTech Connect

    Wang, Dongliang; Li, K.; Sourirajan, S.; Teo, W.K. . Dept. of Chemical Engineering)

    1993-12-10

    The precipitation values (PVs) of several organic nonsolvents in polysulfone (PSf)/solvent and polyethersulfone (PESf)/solvent systems were measured in temperatures ranging from 10 to 80 C by the direct titration method and compared with those of water in the same systems. The solvents used were N-methyl-2-pyrrolidone (NMP) and N,N-dimethylacetamide (DMAC); the organic nonsolvents employed were methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol, ethylene glycol, and diethylene glycol as well as acetic acid and propionic acid. The compositions of nonsolvent, polymer, and solvent at the precipitation points for different polymer concentrations up to 10 wt% were also determined at 30 C with respect to both the polymers and six nonsolvents presented. These results were used to obtain the polymer precipitation curves in the polymer-solvent-nonsolvent triangular phase diagrams and to determine the theta composition of solvent-nonsolvent triangular phase diagrams and to determine the theta composition of solvent-nonsolvent for a polymer. The effect of temperature on the precipitation value was observed to be dramatically different for different polymer/solvent/nonsolvent systems. These results were explained on the basis of polar and nonpolar interactions of the polymer, solvent, and nonsolvent system.

  13. Solvent extraction of diatomite

    SciTech Connect

    Williams, W.

    1984-07-24

    There is provided a method of extracting hydrocarbons from a diatomite ore. The particle size of the ore is first reduced to form a processed ore. The processed ore is then mixed with a substantially irregular granular material to form an unstratified ore mixture having increased permeability to an extracting solvent. The unstratified ore mixture is then permeated with an extracting solvent to obtain a hydrocarbon-solvent stream from which hydrocarbons are subsequently separated. The irregular granular material may be sand.

  14. Solvent extraction process

    SciTech Connect

    Woodle, R.A.

    1982-01-19

    A solvent refining process is disclosed utilizing n-methyl-2-pyrrolidone as solvent in which primary extract from the extraction zone is cooled to form a secondary raffinate and secondary extract and the secondary and primary raffinates are blended to produce an increased yield of product of desired quality. In a preferred embodiment of the process, the lubricating oil feedstock to the process is first contacted with a stripping medium previously used in the process for the recovery of solvent from at least one of the product streams whereby solvent contained in said stripping medium is recovered therefrom.

  15. Implicit solvent methods for free energy estimation

    PubMed Central

    Decherchi, Sergio; Masetti, Matteo; Vyalov, Ivan; Rocchia, Walter

    2014-01-01

    Solvation is a fundamental contribution in many biological processes and especially in molecular binding. Its estimation can be performed by means of several computational approaches. The aim of this review is to give an overview of existing theories and methods to estimate solvent effects giving a specific focus on the category of implicit solvent models and their use in Molecular Dynamics. In many of these models, the solvent is considered as a continuum homogenous medium, while the solute can be represented at the atomic detail and at different levels of theory. Despite their degree of approximation, implicit methods are still widely employed due to their trade-off between accuracy and efficiency. Their derivation is rooted in the statistical mechanics and integral equations disciplines, some of the related details being provided here. Finally, methods that combine implicit solvent models and molecular dynamics simulation, are briefly described. PMID:25193298

  16. Industry Employment

    ERIC Educational Resources Information Center

    Occupational Outlook Quarterly, 2010

    2010-01-01

    This article illustrates projected employment change from an industry perspective over the 2008-2018 decade. Workers are grouped into an industry according to the type of good produced or service provided by the establishment in which they work. Industry employment projections are shown in terms of numeric change (growth or decline in the total…

  17. Engaging Employers?

    ERIC Educational Resources Information Center

    Hillier, Yvonne

    2008-01-01

    A key factor in the successful development of workplace learning is employer engagement (Leitch, 2006; DfES, 2007). However, despite numerous approaches by government in the United Kingdom to bring together employers, providers and learners so that economic success is generated by a skilled and flexible workforce, there continue to be challenges…

  18. Industry Employment

    ERIC Educational Resources Information Center

    Occupational Outlook Quarterly, 2012

    2012-01-01

    This article illustrates projected employment change by industry and industry sector over 2010-20 decade. Workers are grouped into an industry according to the type of good produced or service provided by the establishment for which they work. Industry employment projections are shown in terms of numeric change (growth or decline in the total…

  19. Maternal Employment

    ERIC Educational Resources Information Center

    Clark, Sam

    1975-01-01

    The overwhelming evidence from years of research is that maternal employment, by itself, has little influence on the behaviors of children. More relevant issues are: mother's reasons for working, family's acceptance of mother's employment, quality of substitute child care, family's social and emotional health, and economic conditions. (Author/AJ)

  20. A permeable rotating-wheel solvent extractor

    NASA Technical Reports Server (NTRS)

    Kahn, D. R.; Nady, L. A.

    1972-01-01

    Column-type device reported employs circular permeable structures of wire mesh screen for extracting solvents from systems with low density differences and low interfacial tensions. Rotating screen wheels of structure fasten to shaft; stationary screen structures are supported by circular bands connected by radial metal arms.

  1. SOLVENT EXTRACTION OF NEPTUNIUM

    DOEpatents

    Butler, J.P.

    1958-08-12

    A process is described for the recovery of neptuniunn from dissolver solutions by solvent extraction. The neptunium containing solution should be about 5N, in nitric acid.and about 0.1 M in ferrous ion. The organic extracting agent is tributyl phosphate, and the neptuniunn is recovered from the organic solvent phase by washing with water.

  2. ONSITE SOLVENT RECOVERY

    EPA Science Inventory

    This study evaluated the product quality, waste reduction/pollution prevention, and economic aspects of three technologies for onsite solvent recovery: atmospheric batch distillation, vacuum heat-pump distillation, and a low-emission vapor degreaser with closed solvent, liquid an...

  3. Solvent-free synthesis

    EPA Science Inventory

    This chapter gives a brief introduction about solvent-free reactions whose importance can be gauged by the increasing number of publications every year during the last decade. The mechanistic aspects of the reactions under solvent-free conditions have been highlighted. Our observ...

  4. Alternative Green Solvents Project

    NASA Technical Reports Server (NTRS)

    Maloney, Phillip R.

    2012-01-01

    Necessary for safe and proper functioning of equipment. Mainly halogenated solvents. Tetrachloride, Trichloroethylene (TCE), CFC-113. No longer used due to regulatory/safety concerns. Precision Cleaning at KSC: Small % of total parts. Used for liquid oxygen (LOX) systems. Dual solvent process. Vertrel MCA (decafluoropentane (DFP) and trons-dichloroethylene) HFE-7100. DFP has long term environmental concerns. Project Goals: a) Identify potential replacements. b) 22 wet chemical processes. c) 3 alternative processes. d) Develop test procedures. e) Contamination and cleaning. f) Analysis. g) Use results to recommend alternative processes. Conclusions: a) No alternative matched Vertrel in this study. b) No clear second place solvent. c) Hydrocarbons- easy; Fluorinated greases- difficult. d) Fluorinated component may be needed in replacement solvent. e) Process may need to make up for shortcoming of the solvent. f) Plasma and SCC02 warrant further testing.

  5. Microencapsulation of terbutaline sulphate by the solvent evaporation technique.

    PubMed

    Manekar, N C; Puranik, P K; Joshi, S B

    1992-01-01

    Terbutaline sulphate microcapsules were prepared by coacervation-phase separation (solvent evaporation) technique using ethyl cellulose as a coating material. Acetone, ethyl alcohol and isopropyl alcohol were employed as solvents for coating material. Microcapsules were evaluated for their drug content, particle size distribution (microscopic method), flow properties, bulk density, in vitro dissolution, drug release kinetics and surface characteristics (scanning electron microscopy). PMID:1403496

  6. CHEMICAL TRANSFORMATIONS USING NON-TRADITIONAL APPROACHES: MICROWAVE-ASSISTED GREENER SYNTHESES IN AQUEOUS MEDIA OR UNDER SOLVENT-FREE CONDITIONS

    EPA Science Inventory

    Microwave (MW) irradiation in conjunction with water as reaction media has proven to be a 'greener' chemical approach for expeditious N-alkylation reactions of amines and hydrazines wherein the reactions under mildly basic conditions afford tertiary amines and double N<...

  7. Use of inhibitory solvents in multi-membrane bioreactor

    NASA Technical Reports Server (NTRS)

    Cho, Toohyon (Inventor); Shuler, Michael L. (Inventor)

    1990-01-01

    An immobilized liquid membrane is employed to allow use of a product-extracting solvent which is normally toxic toward a cell layer which produces the product in a membrane-moderated biological reaction.

  8. Solvent alternatives guide

    SciTech Connect

    Elion, J.M.; Monroe, K.R.; Hill, E.A.

    1996-06-01

    It is no longer legal to manufacture or import chlorofluorocarbon 113 or methyl chloroform solvents, and companies that currently clean their parts with either material are now required to implement environmentally safe substitutes. To help find alternative methods, Research Triangle Institute`s Surface Cleaning Technology Program has designed a Solvent Alternatives Guide (SAGE), an online tool that enables access to practical information and recommendations for acceptable solvents. Developed in partnership with the US Environmental Protection Agency, SAGE is available free of charge on the Internet`s World Wide Web.

  9. Effects of tertiary amine local anesthetics on the assembly and disassembly of brain microtubules in vitro.

    PubMed

    Genna, J M; Coffe, G; Pudles, J

    1980-09-01

    From kinetic and electron microscopy studies on the effects of procaine, tetracaine and dibucaine on the polymerization and depolymerization of the microtubules isolated from pig and rat brains the following results were obtained. 1. Procaine or tetracaine, at the concentration range of 0.5--20 mM and of 0.5--5 mM respectively, increases the rate of tubulin polymerization (24 degrees C or 37 degrees C) and of microtubule depolymerization (4 degrees C) as a linear function of the concentration of the anesthetics, while identical amounts of microtubules are formed. In the absence of microtubule-associated proteins the polymerization of tubulin is not induced by 10 mM procaine, furthermore, the critical concentration of microtubule proteins necessary for assembly into microtubules is not affected at this concentration level of the anesthetic. This suggests that procaine affects not the nucleation, but rather the elongation process. 2. Dibucaine, from 0.5 mM to 3 mM increases the lag time of the polymerization reaction, while from 0.5 mM to 2 mM it linearly decreases both tubulin polymerization (24 degrees C) and microtubule depolymerization (4 degrees C) rates. Dibucaine, up to mM concentration, does not affect the extent of tubulin polymerization; however, above this concentration it induces the formation of amorphous aggregates. 3. Procaine or tetracaine enhances the depolymerizing effect of calcium on microtubules. The half-maximal values for the depolymerizing effect of calcium were 0.96, 0.71 and 0.51 mM for the control, in the presence of 10 mM procaine and 5 mM tetracaine respectively. PMID:7439170

  10. Tertiary-Amine Functionalized Polyplexes Enhanced Cellular Uptake and Prolonged Gene Expression

    PubMed Central

    Lo, Chia-Wen; Chang, Yung; Lee, Jyun-Lin; Tsai, Wei-Bor; Chen, Wen-Shiang

    2014-01-01

    Ultrasound (US) has been found to facilitate the transport of DNA across cell membranes. However, the transfection efficiency is generally low, and the expression duration of the transfected gene is brief. In this study, a tertiary polycation, Poly(2-(dimethylamino) ethyl methacrylate) (PDMAEMA), was used as a carrier for US-mediated gene transfection. Its in-vitro and in-vivo effects on the transfection efficiency and the expression duration were evaluated. A mixture of pCI-neo-luc and PDMAEMA was transfected to cultured cells or mouse muscle by exposure to 1-MHz pulse US. A strong expression of luciferase was found 10 days after the transfection in vitro regardless of US exposure. However, effective transfection only occurred in the US groups in vivo. The transfection ability depended on the weight ratio of PDMAEMA to DNA, and was different for the in-vitro and in-vivo conditions. Lower weight ratios, e.g., 0.25, exhibited better in-vivo expression for at least 45 days. PMID:24827929

  11. Kinetic study of carbon dioxide reaction with tertiary amines in aqueous solutions

    SciTech Connect

    Barth, D.; Tondre, C.; Lappai, G.; Delpuech, J.J.

    1981-11-26

    Reaction kinetics of CO/sub 2/ with triethanolamine (TEA) and methyldiethanolamine (MDEA) in aqueous solution have been studied by using a stopped-flow technique with pH detection. Rate constants are obtained from the comparison of experimental and theoretical curves giving the optical density as a function of time. At concentrations of CO/sub 2/ well below the saturation limit, the results are consistent with the hydration reactions of the CO/sub 2/ molecules either with neutral water molecules or with hydroxide ions, depending upon the pH, itself governed by the ionization equilibrium of the dissolved amine. Moreover, a specific (catalytic) reaction, first order with respect to both carbon dioxide and amine (rate constant, 2.85 M/sup -1/ s/sup -1/ at 25/sup 0/C), has been shown to contribute significantly to the reaction rate in the case of the first amine (TEA) only.

  12. Reaction mechanisms of secondary and tertiary amines with OH and NO3 radicals

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Emissions of aliphatic amines are common near agricultural facilities such as animal feed lots. Determining the reactions of these amines with common atmospheric radicals is important to understanding both daytime and nighttime atmospheric chemistry. Several smog chamber experiments were conducted ...

  13. Method and system for ethanol production

    DOEpatents

    Feder, H.M.; Chen, M.J.

    1980-05-21

    A transition metal carbonyl and a tertiary amine are employed as a homogeneous catalytic system in methanol or a less volatile solvent to react methanol with carbon monoxide and hydrogen gas producing ethanol and carbon dioxide. The gas contains a high carbon monoxide to hydrogen ratio as is present in a typical gasifier product. The reaction has potential for anhydrous ethanol production as carbon dioxide rather than water is produced. The only other significant by-product is methane. Selected transition metal carbonyls include those of iron, ruthenium and possibly manganese and osmium. Selected amines include trimethylamine, N-Methylpyrrolidine, 24-diazabicyclooctane, dimethyneopentylamine and 2-pryidinol.

  14. Method and system for ethanol production

    DOEpatents

    Feder, Harold M.; Chen, Michael J.

    1983-01-01

    A transition metal carbonyl and a tertiary amine are employed as a homogeneous catalytic system in methanol or a less volatile solvent to react methanol with carbon monoxide and hydrogen gas producing ethanol and carbon dioxide. The gas contains a high carbon monoxide to hydrogen ratio as is present in a typical gasifier product. The reaction has potential for anhydrous ethanol production as carbon dioxide rather than water is produced. Selected transition metal carbonyls include those of iron, rhodium ruthenium, manganese in combination with iron and possibly osmium. Selected amines include trimethylamine, N-Methylpyrrolidine, 2,4-diazabicyclooctane, dimethylneopentylamine, N-methylpiperidine and derivatives of N-methylpiperidine.

  15. Method and system for ethanol production

    DOEpatents

    Feder, H.M.; Chen, M.J.

    1981-09-24

    A transition metal carbonyl and a tertiary amine are employed as a homogeneous catalytic system in methanol or a less volatile solvent to react methanol with carbon monoxide and hydrogen gas producing ethanol and carbon dioxide. The gas contains a high carbon monoxide to hydrogen ratio as is present in a typical gasifier product. The reaction has potential for anhydrous ethanol production as carbon dioxide rather than water is produced. Selected transition metal carbonyls include those of iron, rhodium, ruthenium, manganese in combination with iron and possibly osmium. Selected amines include trimethylamine, N-Methylpyrrolidine, 2,4-diazabicyclooctane, dimethylneopentylamine, N-methylpiperidine and derivatives of N-methylpiperidine.

  16. Method and system for ethanol production

    DOEpatents

    Feder, Harold M.; Chen, Michael J.

    1981-01-01

    A transition metal carbonyl and a tertiary amine are employed as a homogeneous catalytic system in methanol or a less volatile solvent to react methanol with carbon monoxide and hydrogen gas producing ethanol and carbon dioxide. The gas contains a high carbon monoxide to hydrogen ratio as is present in a typical gasifier product. The reaction has potential for anhydrous ethanol production as carbon dioxide rather than water is produced. The only other significant by product is methane. Selected transition metal carbonyls include those of iron, ruthenium and possibly manganese and osmium. Selected amines include trimethylamine, N-Methylpyrrolidine, 24-diazabicyclooctane, dimethyneopentylamine and 2-pryidinol.

  17. CHLORINATED SOLVENT PLUME CONTROL

    EPA Science Inventory

    This lecture will cover recent success in controlling and assessing the treatment of shallow ground water plumes of chlorinated solvents, other halogenated organic compounds, and methyl tert-butyl ether (MTBE).

  18. Continuous countercurrent membrane column for the separation of solute/solvent and solvent/solvent systems

    DOEpatents

    Nerad, Bruce A.; Krantz, William B.

    1988-01-01

    A reverse osmosis membrane process or hybrid membrane - complementary separator process for producing enriched product or waste streams from concentrated and dilute feed streams for both solvent/solvent and solute/solvent systems is described.

  19. Supercritical solvent coal extraction

    NASA Technical Reports Server (NTRS)

    Compton, L. E. (Inventor)

    1984-01-01

    Yields of soluble organic extract are increased up to about 50% by the supercritical extraction of particulate coal at a temperature below the polymerization temperature for coal extract fragments (450 C.) and a pressure from 500 psig to 5,000 psig by the conjoint use of a solvent mixture containing a low volatility, high critical temperature coal dissolution catalyst such as phenanthrene and a high volatility, low critical temperature solvent such as toluene.

  20. SOLVENT EXTRACTION OF RUTHENIUM

    DOEpatents

    Hyman, H.H.; Leader, G.R.

    1959-07-14

    The separation of rathenium from aqueous solutions by solvent extraction is described. According to the invention, a nitrite selected from the group consisting of alkali nitrite and alkaline earth nitrite in an equimolecular quantity with regard to the quantity of rathenium present is added to an aqueous solution containing ruthenium tetrantrate to form a ruthenium complex. Adding an organic solvent such as ethyl ether to the resulting mixture selectively extracts the rathenium complex.

  1. Occupational Employment

    ERIC Educational Resources Information Center

    Occupational Outlook Quarterly, 2012

    2012-01-01

    When choosing a career, jobseekers often want to know which occupations offer the best prospects. Generally, occupations that have rapid job growth, many new jobs, or many job openings--and good wages--promise better opportunities. This paper shows how employment in particular occupations is projected to change from 2010 to 2020. It presents…

  2. Occupational Employment

    ERIC Educational Resources Information Center

    Occupational Outlook Quarterly, 2010

    2010-01-01

    When choosing a career, jobseekers often want to know which occupations offer the best prospects. Generally, occupations that have rapid job growth, many new jobs, or many job openings--and good wages--promise better opportunities. This article shows how employment in particular occupations is projected to change over the 2008-2018 decade. The…

  3. LLNL solvent substitution

    SciTech Connect

    Benkovitch, M.G.

    1992-12-01

    Allied-Signal Inc., Kansas City Division (KCD), manufactures the electrical, electromechanical, mechanical, and plastic components for nuclear weapons. The KCD has made a commitment to eliminate the use of chlorohydrocarbon (CHC) and chlorofluorocarbon (CFC) solvents to the greatest technical extent possible consistent with nuclear safety and stockpile reliability requirements by July 1993. Several non-halogenated solvents (Exxate 1000, Bioact EC-7, Bioact EC-7R, d-limonene, ACT-100, Kester 5769, and isopropyl alcohol) were evaluated to determine the most effective, non-chlorinated non-fluorinated, alternate solvent cleaning system for a particular electronic assembly in lieu of the current trichloroethylenefisopropyl alcohol baseline cleaning process. All of these solvents were evaluated using current manual spray cleaning processes. The solvents were evaluated for their effectiveness in removing a rosin based RMA solder flux, a particular silicone mold release, and a wide variety of general contaminants (oils, greases, mold releases, resins, etc.) normally found in production departments. A DI water/isopropyl alcohol spray cleaning process was also evaluated for removing two organic acid fluxes. Test samples were contaminated, spray cleaned with the appropriate solvent, and then analyzed for cleanliness. The Meseran Surface Analyzer was used to measure,, organic contamination on the samples before and after cleaning. An Omega Meter Model 600 was also used to detect solder flux residues.

  4. Cleaning without chlorinated solvents

    SciTech Connect

    Thompson, L.M.; Simandl, R.F.

    1994-12-31

    Because of health and environmental concerns, many regulations have been passed in recent years regarding the use of chlorinated solvents. The Oak Ridge Y-12 Plant has had an active program to find alternatives for these solvents used in cleaning applications for the past 7 years. During this time frame, the quantity of solvents purchased has been reduced by 92%. The program has been a twofold effort. Vapor degreasers used in batch cleaning-operations have been replaced by ultrasonic cleaning with aqueous detergent, and other organic solvents have been identified for use in hand-wiping or specialty operations. In order to qualify these alternatives for use, experimentation was conducted on cleaning ability as well as effects on subsequent operations such as welding, painting and bonding. Cleaning ability was determined using techniques such as X-ray photoelectron spectroscopy (XPS) and Fourier Transform Infrared Spectroscopy (FTIR) which are capable of examining monolayer levels of contamination on a surface. Solvents have been identified for removal of rust preventative oils, lapping oils, machining coolants, lubricants, greases, and mold releases. Solvents have also been evaluated for cleaning urethane foam spray guns, swelling of urethanes and swelling of epoxies.

  5. Cleaning without chlorinated solvents

    NASA Technical Reports Server (NTRS)

    Thompson, L. M.; Simandl, R. F.

    1995-01-01

    Because of health and environmental concerns, many regulations have been passed in recent years regarding the use of chlorinated solvents. The Oak Ridge Y-12 Plant has had an active program to find alternatives for these solvents used in cleaning applications for the past 7 years. During this time frame, the quantity of solvents purchased has been reduced by 92 percent. The program has been a twofold effort. Vapor degreasers used in batch cleaning operations have been replaced by ultrasonic cleaning with aqueous detergent, and other organic solvents have been identified for use in hand-wiping or specialty operations. In order to qualify these alternatives for use, experimentation was conducted on cleaning ability as well as effects on subsequent operations such as welding, painting, and bonding. Cleaning ability was determined using techniques such as x-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) which are capable of examining monolayer levels of contamination on a surface. Solvents have been identified for removal of rust preventative oils, lapping oils, machining coolants, lubricants, greases, and mold releases. Solvents have also been evaluated for cleaning urethane foam spray guns, swelling of urethanes, and swelling of epoxies.

  6. Contraction of weak polyelectrolyte multilayers in response to organic solvents.

    PubMed

    Gu, Yuanqing; Ma, Yubing; Vogt, Bryan D; Zacharia, Nicole S

    2016-02-14

    Weak polyelectrolyte multilayers (PEMs) prepared by the layer-by-layer assembly technique have recently been found to demonstrate a unique contraction upon exposure to organic solvents. This response is dependent upon which organic solvent is employed, and fundamental questions have not been clarified regarding the correlation of the magnitude of the film contraction with solvent type. In this work, we used solubility parameters to analyze the response of branched poly(ethylene imine)/poly(acrylic acid) (BPEI/PAA) multilayers when exposed to a variety of solvents. BPEI/PAA multilayers were immersed in a series of 16 different organic solvents and solvent mixtures. Immersion in organic solvent caused film dehydration and therefore contraction and also induced changes in the mechanical properties of PEMs. The film thickness was the best predictor of how a film swelled in water or contracted in organic solvent when using different batches of commercially available polyelectrolytes, rather than polyelectrolyte assembly pH conditions. The degree of film contraction was correlated with Hansen and Kamlet-Taft solubility parameters as well as solvent dielectric constant. In most cases, the hydrogen bonding ability of solvents is the primary factor to determine the magnitude of film contraction. For these solvents, increasing the temperature which corresponds to decreasing the strength of hydrogen bonding, also decreases the ability to dehydrate the films. For solvents that do not follow these trends with the strength of hydrogen bonding, a stronger correlation was found between contraction and dielectric constant, indicating that both traditional solvent quality arguments and electrostatics are important to understanding the contraction of PEMs in organic solvents. PMID:26699080

  7. Method for destroying halocarbon compositions using a critical solvent

    DOEpatents

    Ginosar, Daniel M.; Fox, Robert V.; Janikowski, Stuart K.

    2006-01-10

    A method for destroying halocarbons. Halocarbon materials are reacted in a dehalogenation process wherein they are combined with a solvent in the presence of a catalyst. A hydrogen-containing solvent is preferred which functions as both a solvating agent and hydrogen donor. To augment the hydrogen donation capacity of the solvent if needed (or when non-hydrogen-containing solvents are used), a supplemental hydrogen donor composition may be employed. In operation, at least one of the temperature and pressure of the solvent is maintained near, at, or above a critical level. For example, the solvent may be in (1) a supercritical state; (2) a state where one of the temperature or pressure thereof is at or above critical; or (3) a state where at least one of the temperature and pressure thereof is near-critical. This system provides numerous benefits including improved reaction rates, efficiency, and versatility.

  8. Organic syntheses employing supercritical carbon dioxide as a reaction solvent

    NASA Technical Reports Server (NTRS)

    Barstow, Leon E. (Inventor); Ward, Glen D. (Inventor); Bier, Milan (Inventor)

    1993-01-01

    Chemical reactions are readily carried out using supercritical carbon dioxide as the reaction medium. Supercritical carbon dioxide is of special value as a reaction medium in reactions for synthesizing polypeptides, for sequencing polypeptides, or for amino acid analysis.

  9. Organic syntheses employing supercritical carbon dioxide as a reaction solvent

    NASA Technical Reports Server (NTRS)

    Barstow, Leon E. (Inventor); Ward, Glen D. (Inventor); Bier, Milan (Inventor)

    1991-01-01

    Chemical reactions are readily carried out using supercritical carbon dioxide as the reaction medium. Supercritical carbon dioxide is of special value as a reaction medium in reactions for synthesizing polypeptides, for sequencing polypeptides, or for amino acid analysis.

  10. Alternative Solvents through Green Chemistry Project

    NASA Technical Reports Server (NTRS)

    Hintze, Paul E.; Quinn, Jacqueline

    2014-01-01

    Components in the aerospace industry must perform with accuracy and precision under extreme conditions, and surface contamination can be detrimental to the desired performance, especially in cases when the components come into contact with strong oxidizers such as liquid oxygen. Therefore, precision cleaning is an important part of a components preparation prior to utilization in aerospace applications. Current cleaning technologies employ a variety of cleaning agents, many of which are halogenated solvents that are either toxic or cause environmental damage. Thus, this project seeks to identify alternative precision cleaning solvents and technologies, including use of less harmful cleaning solvents, ultrasonic and megasonic agitation, low-pressure plasma cleaning techniques, and supercritical carbon dioxide extraction. Please review all data content found in the Public Data tab located at: https:techport.nasa.govview11697public

  11. Electrochemistry in deep eutectic solvents.

    PubMed

    Nkuku, Chiemela A; LeSuer, Robert J

    2007-11-22

    We report the cyclic voltammetry, chronoamperometry, and scanning electrochemical microscopy of ferrocene dissolved in deep eutectic solvents (DES), consisting of choline chloride (ChCl) and either trifluoroacetamide (TFA) or malonic acid as the hydrogen-bond donor. Despite the use of ultramicroelectrodes, which were required due to the modest conductivities of the DES employed, linear diffusion behavior was observed in cyclic voltammetric experiments. The high viscosity of 1:2 ChCl/TFA relative to non-aqueous electrochemical solvents leads to a low diffusion coefficient, 2.7 x 10(-8) cm2 s(-1) for ferrocene in this medium. Because of the difficulties in achieving steady-state conditions, SECM approach curves were tip velocity dependent. Under certain conditions, SECM approach curves to an insulating substrate displayed a positive-feedback response. Satisfactory simulation of this unexpected behavior was obtained by including convection terms into the mass transport equations typically used for SECM theory. The observance of positive-feedback behavior at an insulating substrate can be described in terms of a dimensionless parameter, the Peclet number, which is the ratio of the convective and diffusive timescales. Fitting insulator approach curves of ferrocene in 1:2 ChCl/TFA shows an apparent increase in the diffusion coefficient with increasing tip velocity, which can be explained by DES behaving as a shear thinning non-Newtonian fluid. PMID:17973421

  12. Science employment

    NASA Astrophysics Data System (ADS)

    Robb, David W.

    1984-04-01

    Rapid growth in private sector high-technology companies coupled with the expected unprecedented U.S. peacetime defense buildup paint an optimistic picture for future employment in scientific and engineering fields, according to forecasts by the National Science Foundation (NSF). Between 1982 and 1987, up to nearly 750,000 new positions will be created in scientific, engineering, or technical fields, a new NSF report states. By 1987 these occupations will account for 4 million jobs, or 3.5% of the total U.S. work force. New positions in the earth sciences are predicted to increase about 2% per year.

  13. Separation by solvent extraction

    DOEpatents

    Holt, Jr., Charles H.

    1976-04-06

    17. A process for separating fission product values from uranium and plutonium values contained in an aqueous solution, comprising adding an oxidizing agent to said solution to secure uranium and plutonium in their hexavalent state; contacting said aqueous solution with a substantially water-immiscible organic solvent while agitating and maintaining the temperature at from -1.degree. to -2.degree. C. until the major part of the water present is frozen; continuously separating a solid ice phase as it is formed; separating a remaining aqueous liquid phase containing fission product values and a solvent phase containing plutonium and uranium values from each other; melting at least the last obtained part of said ice phase and adding it to said separated liquid phase; and treating the resulting liquid with a new supply of solvent whereby it is practically depleted of uranium and plutonium.

  14. Halogenated solvent remediation

    DOEpatents

    Sorenson, Kent S.

    2004-08-31

    Methods for enhancing bioremediation of ground water contaminated with nonaqueous halogenated solvents are disclosed. A preferred method includes adding a composition to the ground water wherein the composition is an electron donor for microbe-mediated reductive dehalogenation of the halogenated solvents and enhances mass transfer of the halogenated solvents from residual source areas into the aqueous phase of the ground water. Illustrative compositions effective in these methods include surfactants such as C.sub.2 -C.sub.4 carboxylic acids and hydroxy acids, salts thereof, esters of C.sub.2 -C.sub.4 carboxylic acids and hydroxy acids, and mixtures thereof. Especially preferred compositions for use in these methods include lactic acid, salts of lactic acid, such as sodium lactate, lactate esters, and mixtures thereof. The microbes are either indigenous to the ground water, or such microbes can be added to the ground water in addition to the composition.

  15. Halogenated solvent remediation

    DOEpatents

    Sorenson, Jr., Kent S.

    2008-11-11

    Methods for enhancing bioremediation of ground water contaminated with nonaqueous halogenated solvents are disclosed. An illustrative method includes adding an electron donor for microbe-mediated anaerobic reductive dehalogenation of the halogenated solvents, which electron donor enhances mass transfer of the halogenated solvents from residual source areas into the aqueous phase of the ground water. Illustrative electron donors include C.sub.2-C.sub.4 carboxylic acids and hydroxy acids, salts thereof, esters of C.sub.2-C.sub.4 carboxylic acids and hydroxy acids, and mixtures thereof, of which lactic acid, salts of lactic acid--such as sodium lactate, lactate esters, and mixtures thereof are particularly illustrative. The microbes are either indigenous to the ground water, or such microbes can be added to the ground water in addition to the electron donor.

  16. Breathing with chlorinated solvents

    SciTech Connect

    McCarty, P.L.

    1997-06-06

    Chlorinated solvents are effective cleaners and in the past dirted solvents were dumped into landfills, stored in tanks that often leaked, or spilled. As a result the most common contaminants of organic groundwater at hazardous waste sites are the two major chlorinated solvents - tetrachloroethylene (PCE) and trichloroethylene (TCE). Both are suspected carcinogens and both are highly resistant to biodegradation. Now however, there is a report of a bacterium that can remove all of the chlorine atoms from both by halorespiration to form ethene, an innocuous end product. This article goes on to discuss the background of biodegradation of chlorinated compounds, why it is so difficult, and what the future is in this area. 9 refs., 1 fig.

  17. Solvent resistant copolyimide

    NASA Technical Reports Server (NTRS)

    Chang, Alice C. (Inventor); St. Clair, Terry L. (Inventor)

    1995-01-01

    A solvent resistant copolyimide was prepared by reacting 4,4'-oxydiphthalic anhydride with a diaimine blend comprising, based on the total amount of the diamine blend, about 75 to 90 mole percent of 3,4'-oxydianiline and about 10 to 25 mole percent p-phenylene diamine. The solvent resistant copolyimide had a higher glass transition temperature when cured at 350.degree. , 371.degree. and 400.degree. C. than LaRC.TM.-IA. The composite prepared from the copolyimide had similar mechanical properties to LaRC.TM.-IA. Films prepared from the copolyimide were resistant to immediate breakage when exposed to solvents such as dimethylacetamide and chloroform. The adhesive properties of the copolyimide were maintained even after testing at 23.degree., 150.degree., 177.degree. and 204.degree. C.

  18. Safe battery solvents

    DOEpatents

    Harrup, Mason K.; Delmastro, Joseph R.; Stewart, Frederick F.; Luther, Thomas A.

    2007-10-23

    An ion transporting solvent maintains very low vapor pressure, contains flame retarding elements, and is nontoxic. The solvent in combination with common battery electrolyte salts can be used to replace the current carbonate electrolyte solution, creating a safer battery. It can also be used in combination with polymer gels or solid polymer electrolytes to produce polymer batteries with enhanced conductivity characteristics. The solvents may comprise a class of cyclic and acyclic low molecular weight phosphazenes compounds, comprising repeating phosphorus and nitrogen units forming a core backbone and ion-carrying pendent groups bound to the phosphorus. In preferred embodiments, the cyclic phosphazene comprises at least 3 phosphorus and nitrogen units, and the pendent groups are polyethers, polythioethers, polyether/polythioethers or any combination thereof, and/or other groups preferably comprising other atoms from Group 6B of the periodic table of elements.

  19. Solvent dewatering coal

    SciTech Connect

    Hardesty, D.E.; Buchholz, H.F.

    1984-07-17

    Drying of wet coal is facilitated by the addition of a nonaqueous solvent, such as acetone, to the coal followed by application of heat to remove both solvent and water from the coal. The coal may be further upgraded by briquetting or pelletizing fine coal particles with waxes and resins extracted from the coal, or the waxes and resins may be left on the coal to reduce the tendency of the coal to reabsorb water. In addition, minerals such as sodium and potassium salts may be removed from the coal to reduce slagging and fouling behavior of the coal.

  20. Essential roles of protein-solvent many-body correlation in solvent-entropy effect on protein folding and denaturation: Comparison between hard-sphere solvent and water

    NASA Astrophysics Data System (ADS)

    Oshima, Hiraku; Kinoshita, Masahiro

    2015-04-01

    In earlier works, we showed that the entropic effect originating from the translational displacement of water molecules plays the pivotal role in protein folding and denaturation. The two different solvent models, hard-sphere solvent and model water, were employed in theoretical methods wherein the entropic effect was treated as an essential factor. However, there were similarities and differences in the results obtained from the two solvent models. In the present work, to unveil the physical origins of the similarities and differences, we simultaneously consider structural transition, cold denaturation, and pressure denaturation for the same protein by employing the two solvent models and considering three different thermodynamic states for each solvent model. The solvent-entropy change upon protein folding/unfolding is decomposed into the protein-solvent pair (PA) and many-body (MB) correlation components using the integral equation theories. Each component is further decomposed into the excluded-volume (EV) and solvent-accessible surface (SAS) terms by applying the morphometric approach. The four physically insightful constituents, (PA, EV), (PA, SAS), (MB, EV), and (MB, SAS), are thus obtained. Moreover, (MB, SAS) is discussed by dividing it into two factors. This all-inclusive investigation leads to the following results: (1) the protein-water many-body correlation always plays critical roles in a variety of folding/unfolding processes; (2) the hard-sphere solvent model fails when it does not correctly reproduce the protein-water many-body correlation; (3) the hard-sphere solvent model becomes problematic when the dependence of the many-body correlation on the solvent number density and temperature is essential: it is not quite suited to studies on cold and pressure denaturating of a protein; (4) when the temperature and solvent number density are limited to the ambient values, the hard-sphere solvent model is usually successful; and (5) even at the ambient

  1. Essential roles of protein-solvent many-body correlation in solvent-entropy effect on protein folding and denaturation: Comparison between hard-sphere solvent and water

    SciTech Connect

    Oshima, Hiraku; Kinoshita, Masahiro

    2015-04-14

    In earlier works, we showed that the entropic effect originating from the translational displacement of water molecules plays the pivotal role in protein folding and denaturation. The two different solvent models, hard-sphere solvent and model water, were employed in theoretical methods wherein the entropic effect was treated as an essential factor. However, there were similarities and differences in the results obtained from the two solvent models. In the present work, to unveil the physical origins of the similarities and differences, we simultaneously consider structural transition, cold denaturation, and pressure denaturation for the same protein by employing the two solvent models and considering three different thermodynamic states for each solvent model. The solvent-entropy change upon protein folding/unfolding is decomposed into the protein-solvent pair (PA) and many-body (MB) correlation components using the integral equation theories. Each component is further decomposed into the excluded-volume (EV) and solvent-accessible surface (SAS) terms by applying the morphometric approach. The four physically insightful constituents, (PA, EV), (PA, SAS), (MB, EV), and (MB, SAS), are thus obtained. Moreover, (MB, SAS) is discussed by dividing it into two factors. This all-inclusive investigation leads to the following results: (1) the protein-water many-body correlation always plays critical roles in a variety of folding/unfolding processes; (2) the hard-sphere solvent model fails when it does not correctly reproduce the protein-water many-body correlation; (3) the hard-sphere solvent model becomes problematic when the dependence of the many-body correlation on the solvent number density and temperature is essential: it is not quite suited to studies on cold and pressure denaturating of a protein; (4) when the temperature and solvent number density are limited to the ambient values, the hard-sphere solvent model is usually successful; and (5) even at the ambient

  2. ENGINEERING BULLETIN: SOLVENT EXTRACTION

    EPA Science Inventory

    Solvent extraction does not destroy hazardous contaminants, but is a means of separating those contaminants from soils, sludges, and sediments, thereby reducing the volume of the hazardous material that must be treated. enerally it is used as one in a series of unit operations an...

  3. SOLVENT EXTRACTION TREATMENT

    EPA Science Inventory

    Solvent extraction does not destroy wastes, but is a means of separating hazardous contaminants from soils, sludges, and sediments, thereby reducing the volume of the hazardous waste that must be treated. enerally it is used as one ina series of unit operations, and can reduce th...

  4. 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.

  5. 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.

  6. Automated solvent concentrator

    NASA Technical Reports Server (NTRS)

    Griffith, J. S.; Stuart, J. L.

    1976-01-01

    Designed for automated drug identification system (AUDRI), device increases concentration by 100. Sample is first filtered, removing particulate contaminants and reducing water content of sample. Sample is extracted from filtered residue by specific solvent. Concentrator provides input material to analysis subsystem.

  7. ONSITE SOLVENT RECOVERY

    EPA Science Inventory

    This study evaluated the product quality, waste reduction/pollution prevention, and economic aspects of three technologies for onsite solvent recovery. The technologies were (1) atmospheric batch distillation, (2) vacuum heat-pump distillation, and (3) low-emission vapor degreas...

  8. DESIGNING GREENER SOLVENTS

    EPA Science Inventory

    Computer-aided design of chemicals and chemical mixtures provides a powerful tool to help engineers identify cleaner process designs and more-benign alternatives to toxic industrial solvents. Three software programs are discussed: (1) PARIS II (Program for Assisting the Replaceme...

  9. Solvent vapor collector

    DOEpatents

    Ellison, Kenneth; Whike, Alan S.

    1979-01-30

    A solvent vapor collector is mounted on the upstream inlet end of an oven having a gas-circulating means and intended for curing a coating applied to a strip sheet metal at a coating station. The strip sheet metal may be hot and solvent vapors are evaporated at the coating station and from the strip as it passes from the coating station to the oven. Upper and lower plenums within a housing of the collector are supplied with oven gases or air from the gas-circulating means and such gases or air are discharged within the collector obliquely in a downstream direction against the strip passing through that collector to establish downstream gas flows along the top and under surfaces of the strip so as, in turn, to induct solvent vapors into the collector at the coating station. A telescopic multi-piece shroud is usefully provided on the housing for movement between an extended position in which it overlies the coating station to collect solvent vapors released thereat and a retracted position permitting ready cleaning and adjustment of that coating station.

  10. Solvent-Ion Interactions in Salt Water: A Simple Experiment.

    ERIC Educational Resources Information Center

    Willey, Joan D.

    1984-01-01

    Describes a procedurally quick, simple, and inexpensive experiment which illustrates the magnitude and some effects of solvent-ion interactions in aqueous solutions. Theoretical information, procedures, and examples of temperature, volume and hydration number calculations are provided. (JN)

  11. Neurotoxic effects of solvent exposure on sewage treatment workers

    SciTech Connect

    Kraut, A.; Lilis, R.; Marcus, M.; Valciukas, J.A.; Wolff, M.S.; Landrigan, P.J.

    1988-07-01

    Nineteen Sewage Treatment Workers (STWs) exposed to industrial sewage that contained benzene, toluene, and other organic solvents at a primary sewage treatment plant in New York City (Plant A) were examined for evidence of solvent toxicity. Fourteen (74%) complained of central nervous system (CNS) symptoms consistent with solvent exposure, including lightheadedness, fatigue, increased sleep requirement, and headache. The majority of these symptoms resolved with transfer from the plant. Men working less than 1 yr at Plant A were more likely to complain of two or more CNS symptoms than men who were working there longer than 1 yr (p = .055). Objective abnormalities in neurobehavioral testing were found in all 4 men working longer than 9 yr at this plant, but in only 5 of 15 employed there for a shorter period (p = .03). These results are consistent with the known effects of solvent exposure. Occupational health personnel must be aware that STWs can be exposed to solvents and other industrial wastes.

  12. Solvent dewaxing of lubricating oils

    SciTech Connect

    Sequeira, A. Jr.

    1991-04-09

    This paper describes improvement in a process for producing a dewaxed lubricating oil from a wax-bearing mineral oil by the steps comprising; mixing the oil with a dewaxing solvent thereby forming an oil-solvent mixture, chilling the oil-solvent mixture to a dewaxing temperature thereby crystallizing the wax and forming an oil-solvent crystalline wax mixture, separating the oil-solvent-crystalline wax mixture to form a dewaxed oil-solvent mixture and crystalline wax, steam stripping the dewaxed oil-solvent mixture at a temperature of 300{degrees}F to 600{degrees}F and pressure of 1 atm to 3 atm, to yield a solvent free dewaxed oil.

  13. DESIGNING ENVIRONMENTALLY BENIGN SOLVENT SUBSTITUTES

    EPA Science Inventory

    Since the signing of 1987 Montreal Protocol, reducing and eliminating the use of harmful solvents has become an internationally imminent environmental protection mission. Solvent substitution is an effective way to achieve this goal. The Program for Assisting the Replacement of...

  14. Solvent substitution for electronic products

    SciTech Connect

    Benkovich, M.K.

    1992-01-01

    Allied-Signal Inc., Kansas City Division (KCD), manufactures the electrical, electrochemical, mechanical, and plastic components for nuclear weapons. The KCD has made a commitment to eliminate the use of chlorohydrocarbon (CHC) and chlorofluorocarbon (CFC) solvents to the greatest technical extent possible consistent with nuclear safety and stockpile reliability requirements. Current cleaning processes in the production departments use trichloroethylene, 1,1,1-trichloroethane, and various CFC-113 based solvents. Several non-halogenated solvents (Solvent A - an aqueous solvent based on N,N-dimethylacetamide, Solvent B - an aqueous mixture of ethanol amines, Solvent C - a hydrocarbon solvent based on octadecyl acetate, Solvent D - a terpene (d-limonene) hydrocarbon solvent combined with emulsifiers, Solvent E - a terpene (d-limonene) hydrocarbon solvent combined with a separation agent, d-limonene, and isopropyl alcohol) were evaluated to determine the most effective, non-chlorinated, non-fluorinated, alternate solvent cleaning system. All of these solvents were evaluated using current manual spray cleaning processes. The solvents were evaluated for their effectiveness in removing a rosin based RMA solder flux, a particular silicone mold release, and oils, greases, mold releases, resins, etc. The Meseran Surface Analyzer was used to measure organic contamination on the samples before and after cleaning. An Omega Meter Model 600 was also used to detect solder flux residues. Solvents C, D, E and d-limonene the best alternatives to trichloroethylene for removing all of the contaminants tested. For this particular electronic assembly, d-limonene was chosen as the alternate because of material compatibility and long-term reliability concerns.

  15. Glove permeation by organic solvents

    SciTech Connect

    Nelson, G.O.; Lum, B.Y.; Carlson, G.J.; Wong, C.M.; Johnson, J.S.

    1981-03-01

    The vapor penetration of 29 common laboratory solvents on 28 protective gloves has been tested and measured using gas-phase, infrared spectrophotometric techniques to determine the permeation characteristics. Five different types of permeation behavior were identified. No one glove offered complete protection against all the solvents tested. The permeation rate of the solvent was found to be inversely proportional to glove thickness for a given manufacturer's material. Of two solvent mixtures tested, one exhibited a large, positive, synergistic rate.

  16. PARIS II: DESIGNING GREENER SOLVENTS

    EPA Science Inventory

    PARIS II (the program for assisting the replacement of industrial solvents, version II), developed at the USEPA, is a unique software tool that can be used for customizing the design of replacement solvents and for the formulation of new solvents. This program helps users avoid ...

  17. Green Solvents for Precision Cleaning

    NASA Technical Reports Server (NTRS)

    Grandelli, Heather; Maloney, Phillip; DeVor, Robert; Surma, Jan; Hintze, Paul

    2013-01-01

    Aerospace machinery used in liquid oxygen (LOX) fuel systems must be precision cleaned to achieve a very low level of non-volatile residue (< 1 mg0.1 m2), especially flammable residue. Traditionally chlorofluorocarbons (CFCs) have been used in the precision cleaning of LOX systems, specifically CFC 113 (C2Cl3F3). CFCs have been known to cause the depletion of ozone and in 1987, were banned by the Montreal Protocol due to health, safety and environmental concerns. This has now led to the development of new processes in the precision cleaning of aerospace components. An ideal solvent-replacement is non-flammable, environmentally benign, non-corrosive, inexpensive, effective and evaporates completely, leaving no residue. Highlighted is a green precision cleaning process, which is contaminant removal using supercritical carbon dioxide as the environmentally benign solvent. In this process, the contaminant is dissolved in carbon dioxide, and the parts are recovered at the end of the cleaning process completely dry and ready for use. Typical contaminants of aerospace components include hydrocarbon greases, hydraulic fluids, silicone fluids and greases, fluorocarbon fluids and greases and fingerprint oil. Metallic aerospace components range from small nuts and bolts to much larger parts, such as butterfly valves 18 in diameter. A fluorinated grease, Krytox, is investigated as a model contaminant in these preliminary studies, and aluminum coupons are employed as a model aerospace component. Preliminary studies are presented in which the experimental parameters are optimized for removal of Krytox from aluminum coupons in a stirred-batch process. The experimental conditions investigated are temperature, pressure, exposure time and impeller speed. Temperatures of 308 - 423 K, pressures in the range of 8.3 - 41.4 MPa, exposure times between 5 - 60 min and impeller speeds of 0 - 1000 rpm were investigated. Preliminary results showed up to 86 cleaning efficiency with the

  18. Hazardous solvent substitution

    SciTech Connect

    Twitchell, K.E.

    1995-11-01

    Eliminating hazardous solvents is good for the environment, worker safety, and the bottom line. However, even though we are motivated to find replacements, the big question is `What can we use as replacements for hazardous solvents?`You, too, can find replacements for your hazardous solvents. All you have to do is search for them. Search through the vendor literature of hundreds of companies with thousands of products. Ponder the associated material safety data sheets, assuming of course that you can obtain them and, having obtained them, that you can read them. You will want to search the trade magazines and other sources for product reviews. You will want to talk to users about how well the product actually works. You may also want to check US Environmental Protection Agency (EPA) and other government reports for toxicity and other safety information. And, of course, you will want to compare the product`s constituent chemicals with the many hazardous constituency lists to ensure the safe and legal use of the product in your workplace.

  19. Effects of Solvent Composition on the Assembly and Relaxation of Triblock Copolymer-Based Polyelectrolyte Gels

    SciTech Connect

    Henderson, Kevin J.; Shull, Kenneth R.

    2012-03-26

    The role of solvent selectivity has been explored extensively with regard to its role in the phase behavior of block copolymer assemblies. Traditionally, thermally induced phase separation is employed for generating micelles upon cooling a block copolymer dissolved in a selective solvent. However few amphiphilic, polyelectrolyte-containing block copolymers demonstrate a thermally accessible route of micellization, and solvent exchange routes are frequently employed instead. Here, we describe the use of mixed solvents for obtaining thermoreversible gelation behavior of poly(methyl methacrylate)-poly(methacrylic acid)-poly(methyl methacrylate) (PMMA-PMAA-PMMA) triblock copolymers. One solvent component (dimethyl sulfoxide) is a good solvent for both blocks, and the second solvent component (water) is a selective solvent for the polymer midblock. Rheological frequency sweeps at variable solvent compositions and temperatures demonstrate an adherence to time-temperature-composition superposition, so that changes in the solvent composition are analogous to changes in the Flory-Huggins interaction parameter between end block and solvent. Shift factors used for this superposition are related to the effective activation energy describing the viscosity and stress relaxation response of the triblock copolymer gels. The effectiveness of solvent exchange processes for producing hydrogels with this system is shown to originate from the ability of a small amount of added water to greatly increase the relaxation times of the self-assembled polymer gels that are formed by this process.

  20. Qualitative and quantitative evaluation of solvent systems for countercurrent separation.

    PubMed

    Friesen, J Brent; Ahmed, Sana; Pauli, Guido F

    2015-01-16

    Rational solvent system selection for countercurrent chromatography and centrifugal partition chromatography technology (collectively known as countercurrent separation) studies continues to be a scientific challenge as the fundamental questions of comparing polarity range and selectivity within a solvent system family and between putative orthogonal solvent systems remain unanswered. The current emphasis on metabolomic investigations and analysis of complex mixtures necessitates the use of successive orthogonal countercurrent separation (CS) steps as part of complex fractionation protocols. Addressing the broad range of metabolite polarities demands development of new CS solvent systems with appropriate composition, polarity (π), selectivity (σ), and suitability. In this study, a mixture of twenty commercially available natural products, called the GUESSmix, was utilized to evaluate both solvent system polarity and selectively characteristics. Comparisons of GUESSmix analyte partition coefficient (K) values give rise to a measure of solvent system polarity range called the GUESSmix polarity index (GUPI). Solvatochromic dye and electrical permittivity measurements were also evaluated in quantitatively assessing solvent system polarity. The relative selectivity of solvent systems were evaluated with the GUESSmix by calculating the pairwise resolution (αip), the number of analytes found in the sweet spot (Nsw), and the pairwise resolution of those sweet spot analytes (αsw). The combination of these parameters allowed for both intra- and inter-family comparison of solvent system selectivity. Finally, 2-dimensional reciprocal shifted symmetry plots (ReSS(2)) were created to visually compare both the polarities and selectivities of solvent system pairs. This study helps to pave the way to the development of new solvent systems that are amenable to successive orthogonal CS protocols employed in metabolomic studies. PMID:25542704

  1. Solvent replacement for green processing.

    PubMed Central

    Sherman, J; Chin, B; Huibers, P D; Garcia-Valls, R; Hatton, T A

    1998-01-01

    The implementation of the Montreal Protocol, the Clean Air Act, and the Pollution Prevention Act of 1990 has resulted in increased awareness of organic solvent use in chemical processing. The advances made in the search to find "green" replacements for traditional solvents are reviewed, with reference to solvent alternatives for cleaning, coatings, and chemical reaction and separation processes. The development of solvent databases and computational methods that aid in the selection and/or design of feasible or optimal environmentally benign solvent alternatives for specific applications is also discussed. Images Figure 2 Figure 3 PMID:9539018

  2. SOLVENT FIRE BY-PRODUCTS

    SciTech Connect

    Walker, D; Samuel Fink, S

    2006-05-22

    Southwest Research Institute (SwRI) conducted a burn test of the Caustic-Side Solvent Extraction (CSSX) solvent to determine the combustion products. The testing showed hydrogen fluoride gas is not a combustion product from a solvent fire when up to 70% of the solvent is consumed. The absence of HF in the combustion gases may reflect concentration of the modifier containing the fluoride groups in the unburned portion. SwRI reported results for other gases (CO, HCN, NOx, formaldehyde, and hydrocarbons). The results, with other supporting information, can be used for evaluating the consequences of a facility fire involving the CSSX solvent inventory.

  3. Occupational solvent exposure and cognition

    PubMed Central

    Sabbath, E.L.; Glymour, M.M.; Berr, C.; Singh-Manoux, A.; Zins, M.; Goldberg, M.

    2012-01-01

    Objective: Chronic occupational solvent exposure is associated with long-term cognitive deficits. Cognitive reserve may protect solvent-exposed workers from cognitive impairment. We tested whether the association between chronic solvent exposure and cognition varied by educational attainment, a proxy for cognitive reserve. Methods: Data were drawn from a prospective cohort of French national gas and electricity (GAZEL) employees (n = 4,134). Lifetime exposure to 4 solvent types (chlorinated solvents, petroleum solvents, benzene, and nonbenzene aromatic solvents) was assessed using a validated job-exposure matrix. Education was dichotomized at less than secondary school or below. Cognitive impairment was defined as scoring below the 25th percentile on the Digit Symbol Substitution Test at mean age 59 (SD 2.8; 88% of participants were retired at testing). Log-binomial regression was used to model risk ratios (RRs) for poor cognition as predicted by solvent exposure, stratified by education and adjusted for sociodemographic and behavioral factors. Results: Solvent exposure rates were higher among less-educated patients. Within this group, there was a dose-response relationship between lifetime exposure to each solvent type and RR for poor cognition (e.g., for high exposure to benzene, RR = 1.24, 95% confidence interval 1.09–1.41), with significant linear trends (p < 0.05) in 3 out of 4 solvent types. Recency of solvent exposure also predicted worse cognition among less-educated patients. Among those with secondary education or higher, there was no significant or near-significant relationship between any quantification of solvent exposure and cognition. Conclusions: Solvent exposure is associated with poor cognition only among less-educated individuals. Higher cognitive reserve in the more-educated group may explain this finding. PMID:22641403

  4. Solvent Fractionation of Lignin

    SciTech Connect

    Chatterjee, Sabornie; Saito, Tomonori

    2014-01-01

    Lignin is a highly abundant source of renewable carbon that can be considered as a valuable sustainable source of biobased materials. The major issues for the commercial production of value added high performance lignin products are lignin s physical and chemical heterogenities. To overcome these problems, a variety of procedures have been developed to produce pure lignin suitable for high performace applications such as lignin-derived carbon materials. However, most of the isolation procedures affect lignin s properties and structure. In this chapter, a short review of the effect of solvent fractionation on lignin s properties and structure is presented.

  5. Microbial process for the preparation of acetic acid, as well as solvent for its extraction from the fermentation broth

    DOEpatents

    Gaddy, James L.; Clausen, Edgar C.; Ko, Ching-Whan; Wade, Leslie E.; Wikstrom, Carl V.

    2004-06-22

    A modified water-immiscible solvent useful in the extraction of acetic acid from aqueous streams is a substantially pure mixture of isomers of highly branched di-alkyl amines. Solvent mixtures formed of such a modified solvent with a desired co-solvent, preferably a low boiling hydrocarbon, are useful in the extraction of acetic acid from aqueous gaseous streams. An anaerobic microbial fermentation process for the production of acetic acid employs such solvents, under conditions which limit amide formation by the solvent and thus increase the efficiency of acetic acid recovery. Methods for the direct extraction of acetic acid and the extractive fermentation of acetic acid also employ the modified solvents and increase efficiency of acetic acid production. Such increases in efficiency are also obtained where the energy source for the microbial fermentation contains carbon dioxide and the method includes a carbon dioxide stripping step prior to extraction of acetic acid in solvent.

  6. Microbial process for the preparation of acetic acid, as well as solvent for its extraction from the fermentation broth

    DOEpatents

    Gaddy, James L.; Clausen, Edgar C.; Ko, Ching-Whan; Wade, Leslie E.; Wikstrom, Carl V.

    2007-03-27

    A modified water-immiscible solvent useful in the extraction of acetic acid from aqueous streams is a substantially pure mixture of isomers of highly branched di-alkyl amines. Solvent mixtures formed of such a modified solvent with a desired co-solvent, preferably a low boiling hydrocarbon, are useful in the extraction of acetic acid from aqueous gaseous streams. An anaerobic microbial fermentation process for the production of acetic acid employs such solvents, under conditions which limit amide formation by the solvent and thus increase the efficiency of acetic acid recovery. Methods for the direct extraction of acetic acid and the extractive fermentation of acetic acid also employ the modified solvents and increase efficiency of acetic acid production. Such increases in efficiency are also obtained where the energy source for the microbial fermentation contains carbon dioxide and the method includes a carbon dioxide stripping step prior to extraction of acetic acid in solvent.

  7. Evaluating Employability Skills: Employer and Student Perceptions

    ERIC Educational Resources Information Center

    Saunders, Venetia; Zuzel, Katherine

    2010-01-01

    Graduate employability is a key issue for Higher Education. In this two-part study student employability skills have been evaluated from the perspective of sandwich students and graduates in biomolecular science, and their employers. A strong correlation was found between employer and sandwich student/graduate perceptions of the relative…

  8. Computational polymer physics: Hard-sphere chain in solvent systems

    NASA Astrophysics Data System (ADS)

    Gautam, Avinash; Gavazzi, Daniel; Taylor, Mark

    2009-10-01

    In this work we present results for chain conformation in two simple chain-in-solvent systems constructed from hard-sphere monomers of diameter D. The first system consists of a flexible chain of fused hard spheres (i.e., bond length L=D) in a monomeric hard-sphere solvent. The second system consists of a flexible tangent hard-sphere chain (L=D) in a dimeric hard-sphere solvent with L=D. These systems are studied using Monte Carlo simulations which employ both single-site crankshaft and multi-site pivot moves to sample the configuration space of the chain. We report chain structure, in terms of site-site probability functions, as a function of solvent density. In all cases, increasing solvent density leads to an overall compression of the chain. At high solvent density the chain conformation is closely coupled to the local solvent structure and we speculate that incommensurate structures may lead to interesting conformational transitions.

  9. Solvents level dipole moments.

    PubMed

    Liang, Wenkel; Li, Xiaosong; Dalton, Larry R; Robinson, Bruce H; Eichinger, Bruce E

    2011-11-01

    The dipole moments of highly polar molecules measured in solution are usually smaller than the molecular dipole moments that are calculated with reaction field methods, whereas vacuum values are routinely calculated in good agreement with available vapor phase data. Whether from Onsager's theory (or variations thereof) or from quantum mechanical methods, the calculated molecular dipoles in solution are found to be larger than those measured. The reason, of course, is that experiments measure the net dipole moment of solute together with the polarized (perturbed) solvent "cloud" surrounding it. Here we show that the reaction field charges that are generated in the quantum mechanical self-consistent reaction field (SCRF) method give a good estimate of the net dipole moment of the solute molecule together with the moment arising from the reaction field charges. This net dipole is a better description of experimental data than the vacuum dipole moment and certainly better than the bare dipole moment of the polarized solute molecule. PMID:21923185

  10. Delineating solute-solvent interactions in binary mixtures of ionic liquids in molecular solvents and preferential solvation approach.

    PubMed

    Khupse, Nageshwar D; Kumar, Anil

    2011-02-01

    The effect of solute-solvent and solvent-solvent interactions on the preferential solvation of solvatochromic indicators in binary mixtures of ionic liquids with molecular solvents has been investigated. The binary mixtures of the pyridinium-based ionic liquids 1-butylpyridinium tetrafluoroborate ([BP][BF4]), 1-butyl-3-methylpyridinium tetrafluoroborate ([3-MBP][BF4]), and 1-butyl-4-methylpyridinium tetrafluoroborate ([4-MBP][BF4]) with molecular solvents like water, methanol, and dichloromethane have been selected for this investigation. The effect of addition of ionic liquids to molecular solvents on the polarity parameters E(T)(N), Kamlet-Taft parameters, hydrogen bond donor ability (HBD) (α), hydrogen bond acceptor ability (HBA) (β), and polarizability (π*) was obtained. The polarity parameters of the mixture display nonideality on addition of ionic liquids to water and dichloromethane. On the other hand, strong synergetic effects were seen in the ionic liquid-methanol binary mixtures. The preferential solvation models have been employed to analyze the collected data in order to achieve information on solute-solvent interactions in these binary mixtures. PMID:21142058

  11. USING A NEURAL NETWORK TO ESTIMATE SOLVENT CONSUMPTION

    EPA Science Inventory

    The paper discusses a neural network, using the backpropagation paradigm, that is taught the relationship between employment in the graphic arts industry--(Standard Industrial Classification Code (SIC) 27--and economic variables and solvent consumption by SIC 27. This project is ...

  12. 29 CFR 1915.32 - Toxic cleaning solvents.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Toxic cleaning solvents. 1915.32 Section 1915.32 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) OCCUPATIONAL SAFETY AND HEALTH STANDARDS FOR SHIPYARD EMPLOYMENT Surface Preparation and Preservation § 1915.32 Toxic...

  13. Supercritical multicomponent solvent coal extraction

    NASA Technical Reports Server (NTRS)

    Corcoran, W. H.; Fong, W. S.; Pichaichanarong, P.; Chan, P. C. F.; Lawson, D. D. (Inventor)

    1983-01-01

    The yield of organic extract from the supercritical extraction of coal with larger diameter organic solvents such as toluene is increased by use of a minor amount of from 0.1 to 10% by weight of a second solvent such as methanol having a molecular diameter significantly smaller than the average pore diameter of the coal.

  14. Toxicological profile for Stoddard solvent

    SciTech Connect

    1995-06-01

    This statement was prepared to give you information about Stoddard solvent and to emphasize the human health effects that may result from exposure to it. The Environmental Protection Agency (EPA) has identified 1,397 sites on its `National Priorities List` (NPL). Stoddard solvent has been found in at least seven of these sites.

  15. SOLVENT EXTRACTION OF URANIUM VALUES

    DOEpatents

    Feder, H.M.; Ader, M.; Ross, L.E.

    1959-02-01

    A process is presented for extracting uranium salt from aqueous acidic solutions by organic solvent extraction. It consists in contacting the uranium bearing solution with a water immiscible dialkylacetamide having at least 8 carbon atoms in the molecule. Mentioned as a preferred extractant is dibutylacetamide. The organic solvent is usually used with a diluent such as kerosene or CCl/sub 4/.

  16. Solvent degradation products in nuclear fuel processing solvents

    SciTech Connect

    Shook, H.E. Jr.

    1988-06-01

    The Savannah River Plant uses a modified Purex process to recover enriched uranium and separate fission products. This process uses 7.5% tri-n-butyl phosphate (TBP) dissolved in normal paraffin hydrocarbons for the solvent extraction of a nitric acid solution containing the materials to be separated. Periodic problems in product decontamination result from solvent degradation. A study to improve process efficiency has identified certain solvent degradation products and suggested mitigation measures. Undecanoic acid, lauric acid, and tridecanoic acid were tentatively identified as diluent degradation products in recycle solvent. These long-chain organic acids affect phase separation and lead to low decontamination factors. Solid phase extraction (SPE) was used to concentrate the organic acids in solvent prior to analysis by high performance liquid chromatography (HPLC). SPE and HPLC methods were optimized in this work for analysis of decanoic acid, undecanoic acid, and lauric acid in solvent. Accelerated solvent degradation studies with 7.5% TBP in normal paraffin hydrocarbons showed that long-chain organic acids and long-chain alkyl butyl phosphoric acids are formed by reactions with nitric acid. Degradation of both tributyl phosphate and hydrocarbon can be minimized with purified normal paraffin replacing the standard grade presently used. 12 refs., 1 fig., 3 tabs.

  17. WASH SOLVENT REUSE IN PAINT PRODUCTION

    EPA Science Inventory

    This project evaluated solvent used to clean paint manufacture equipment for its utility in production of subsequent batches of solvent-borne paint. eusing wash solvent would reduce the amount of solvent disposed of as waste. he evaluation of this wash-solvent recovery technology...

  18. COMPUTER AIDED SOLVENT DESIGN FOR THE ENVIRONMENT

    EPA Science Inventory

    Solvent substitution is an effective and useful means of eliminating the use of harmful solvents, but finding substitute solvents which are less harmful and as effective as currently used solvents presents significant difficulties. Solvent substitution is a form of reverse engin...

  19. Inertial solvent dynamics and the analysis of spectral line shapes: Temperature-dependent absorption spectrum of beta-carotene in nonpolar solvent.

    PubMed

    Burt, Jim A; Zhao, Xihua; McHale, Jeanne L

    2004-03-01

    The influence of solvent dynamics on optical spectra is often described by a stochastic model which assumes exponential relaxation of the time-correlation function for solvent-induced frequency fluctuations. In contrast, theory and experiment suggest that the initial (subpicosecond) phase of solvent relaxation, resulting from inertial motion of the solvent, is a Gaussian function of time. In this work, we employ numerical and analytical calculations to compare the predicted absorption line shapes and the derived solvent reorganization energies obtained from exponential (Brownian oscillator) versus Gaussian (inertial) solvent dynamics. Both models predict motional narrowing as the ratio kappa = Lambda/Delta is increased, where Lambda and Delta are the frequency and variance, respectively, of the solvent-induced frequency fluctuations. However, the motional narrowing limit is achieved at lower values of kappa for the Brownian oscillator model compared to the inertial model. For a given line shape, the derived value of the solvent reorganization energy lambdasolv is only weakly dependent on the solvent relaxation model employed, though different solvent parameters Lambda and Delta are obtained. The two models are applied to the analysis of the temperature-dependent absorption spectrum of beta-carotene in isopentane and CS2. The derived values of lambdasolv using the Gaussian model are found to be in better agreement with the high temperature limit of Delta2/2kBT than are the values obtained using the Brownian oscillator model. In either approach, the solvent reorganization energy is found to increase slightly with temperature as a result of an increase in the variance Delta of the solvent-induced frequency fluctuations. PMID:15268604

  20. Inertial solvent dynamics and the analysis of spectral line shapes: Temperature-dependent absorption spectrum of β-carotene in nonpolar solvent

    NASA Astrophysics Data System (ADS)

    Burt, Jim A.; Zhao, Xihua; McHale, Jeanne L.

    2004-03-01

    The influence of solvent dynamics on optical spectra is often described by a stochastic model which assumes exponential relaxation of the time-correlation function for solvent-induced frequency fluctuations. In contrast, theory and experiment suggest that the initial (subpicosecond) phase of solvent relaxation, resulting from inertial motion of the solvent, is a Gaussian function of time. In this work, we employ numerical and analytical calculations to compare the predicted absorption line shapes and the derived solvent reorganization energies obtained from exponential (Brownian oscillator) versus Gaussian (inertial) solvent dynamics. Both models predict motional narrowing as the ratio κ=Λ/Δ is increased, where Λ and Δ are the frequency and variance, respectively, of the solvent-induced frequency fluctuations. However, the motional narrowing limit is achieved at lower values of κ for the Brownian oscillator model compared to the inertial model. For a given line shape, the derived value of the solvent reorganization energy λsolv is only weakly dependent on the solvent relaxation model employed, though different solvent parameters Λ and Δ are obtained. The two models are applied to the analysis of the temperature-dependent absorption spectrum of β-carotene in isopentane and CS2. The derived values of λsolv using the Gaussian model are found to be in better agreement with the high temperature limit of Δ2/2kBT than are the values obtained using the Brownian oscillator model. In either approach, the solvent reorganization energy is found to increase slightly with temperature as a result of an increase in the variance Δ of the solvent-induced frequency fluctuations.

  1. Employer Perspectives on Employer-Rehabilitation Partnerships.

    ERIC Educational Resources Information Center

    Greenwood, Reed; And Others

    1988-01-01

    The article presents results of a study of employers (N=100) regarding their concerns about disabled workers and employer interest in partnership with rehabilitation agencies. Employers were questioned concerning recruitment and selection, technical assistance from rehabilitation organizations, incentives, and mid-career disability onset.…

  2. Cesium Concentration in MCU Solvent

    SciTech Connect

    Walker, D

    2006-01-18

    During Modular Caustic-Side Solvent Extraction (CSSX) Unit (MCU) operations, Cs-137 concentrations in product streams will vary depending on the location in the process and on the recent process conditions. Calculations of cesium concentrations under a variety of operating conditions reveal the following: (1) Under nominal operations with salt solution feed containing 1.1 Ci Cs-137 per gallon, the maximum Cs-137 concentration in the process will occur in the strip effluent (SE) and equal 15-16.5 Ci/gal. (2) Under these conditions, the majority of the solvent will contain 0.005 to 0.01 Ci/gal, with a limited portion of the solvent in the contactor stages containing {approx}4 Ci/gal. (3) When operating conditions yield product near 0.1 Ci Cs-137/gal in the decontaminated salt solution (DSS), the SE cesium concentration will be the same or lower than in nominal operations, but majority of the stripped solvent will increase to {approx}2-3 Ci/gal. (4) Deviations in strip and waste stream flow rates cause the largest variations in cesium content: (a) If strip flow rates deviate by -30% of nominal, the SE will contain {approx}23 Ci/gal, although the cesium content of the solvent will increase to only 0.03 Ci/gal; (b) If strip flow rate deviates by -77% (i.e., 23% of nominal), the SE will contain 54 Ci/gal and solvent will contain 1.65 Ci/gal. At this point, the product DSS will just reach the limit of 0.1 Ci/gal, causing the DSS gamma monitors to alarm; and (c) Moderate (+10 to +30%) deviations in waste flow rate cause approximately proportional increases in the SE and solvent cesium concentrations. Recovery from a process failure due to poor cesium stripping can achieve any low cesium concentration required. Passing the solvent back through the contactors while recycling DSS product will produce a {approx}70% reduction during one pass through the contactors (assuming the stripping D value is no worse than 0.36). If the solvent is returned to the solvent hold tank

  3. Solvent-free and catalyst-free chemistry: A benign pathway to sustainability

    EPA Science Inventory

    In the past decade, alternative benign organic methodologies have become an imperative part of organic syntheses and novel chemical reactions. The various new and innovative sustainable organic reactions and methodologies using no solvents or catalysts and employing alternative ...

  4. 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.

  5. EXPERIENCES IN DESIGNING SOLVENTS FOR THE ENVIRONMENT

    EPA Science Inventory

    To meet the great need of replacing many harmful solvents commonly used by industry and the public with environmentally benign substitute solvents, the PARIS II solvent design software has been developed. Although the difficulty of successfully finding replacements increases with...

  6. Chromatographic NMR in NMR solvents

    NASA Astrophysics Data System (ADS)

    Carrara, Caroline; Viel, Stéphane; Delaurent, Corinne; Ziarelli, Fabio; Excoffier, Grégory; Caldarelli, Stefano

    2008-10-01

    Recently, it was demonstrated that pseudo-chromatographic NMR experiments could be performed using typical chromatographic solids and solvents. This first setup yielded improved separation of the spectral components of the NMR spectra of mixtures using PFG self-diffusion measurements. The method (dubbed Chromatographic NMR) was successively shown to possess, in favorable cases, superior resolving power on non-functionalized silica, compared to its LC counterpart. To further investigate the applicability of the method, we studied here the feasibility of Chromatographic NMR in common deuterated solvents. Two examples are provided, using deuterated chloroform and water, for homologous compounds soluble in these solvents, namely aromatic molecules and alcohols, respectively.

  7. Caustic-Side Solvent Extraction Solvent-Composition Recommendation

    SciTech Connect

    Klatt, L.N.

    2002-05-09

    The U.S. Department of Energy has selected caustic-side solvent extraction as the preferred cesium removal technology for the treatment of high-level waste stored at the Savannah River Site. Data for the solubility of the extractant, calix[4]arene-bis(tert-octyl benzo-crown-6), acquired and reported for the Salt Processing Program down-select decision, showed the original solvent composition to be supersaturated with respect to the extractant. Although solvent samples have been observed for approximately 1 year without any solids formation, work was completed to define a new solvent composition that was thermodynamically stable with respect to solids formation and to expand the operating temperature with respect to third-phase formation. Chemical and physical data as a function of solvent component concentrations were collected. The data included calix[4]arene-bis(tert-octyl benzo-crown-6) solubility; cesium distribution ratio under extraction, scrub, and strip conditions; flow sheet robustness; temperature range of third-phase formation; dispersion numbers for the solvent against waste simulant, scrub and strip acids, and sodium hydroxide wash solutions; solvent density; viscosity; and surface and interfacial tension. These data were mapped against a set of predefined performance criteria. The composition of 0.007 M calix[4]arene-bis(tert-octyl benzo-crown-6), 0.75 M 1-(2,2,3,3-tetrafluoropropoxy)-3-(4-sec-butylphenoxy)-2-propanol, and 0.003 M tri-n-octylamine in the diluent Isopar{reg_sign} L provided the best match between the measured properties and the performance criteria. Therefore, it is recommended as the new baseline solvent composition.

  8. Preparing Youth for Employment.

    ERIC Educational Resources Information Center

    Bishop, John

    A four-year study examined the nature and policy implications of school and employer practices to help youth prepare for employment. Data for the study were compiled from a telephone survey of 3,500 employers; a mail survey of 750 employers from across the country; 493 employers, 71 teachers, and 1,565 students from 5 major U.S. cities who…

  9. The Influence of Different Physicochemical Parameters of the Solvent On The Activity and Selectivity of Lipase.

    PubMed

    Gao, Xiu-Gong; Cao, Shu-Gui; Zhang, Ke-Chang

    1997-01-01

    The asymmetric esterification of octanoic acid with racemic 2-octanol catalyzed by a lipase from Pseudomonas sp. was investigated in several typical solvents. It was found that the catalytic activity and the enantioselectivity of the enzyme were governed by different physicochemical parameters of the solvent employed. While the former depended on the hydrophobicity (lgP) of the solvent, by contrast the latter was a function of the dielectric constant and the dipole moment. A mechanistic model for the binding site of the enzyme was postulated to rationalize this phenomenon based on the results of the kinetic studies of the reaction in some representative solvents. PMID:12215797

  10. [Extraction characteristics of sequential accelerated solvent extraction for polycyclic aromatic hydrocarbons in environmental mediums].

    PubMed

    Ma, Xiao-xuan; Ran, Yong

    2009-12-01

    Polycyclic aromatic hydrocarbons (PAHs) in two soils, two sediments and an shale from the Pearl River Delta were extracted by sequential accelerated solvent extraction (ASE) with each of four different organic solvents for three times. PAHs in the first extract accounts for more than half of their total contents, and toluene displays the best extraction performance among the four employed solvents. For a given sample the source diagnostic ratios of PAHs in sequential ASE with each solvent are very similar, suggesting the validity of those ratios in source judgement by different extraction methods. PMID:20187409

  11. Recovery of solvent in hydrocarbon processing systems. [N-methyl-2pyrrolidone

    SciTech Connect

    Sherman, P.B.

    1983-06-28

    This is a claim for a lubricating oil solvent refining process employing n-methyl-2pyrrolidone as solvent in which solvent is recovered from a solvent-oil mixture in a staged series of vaporization zones at progressively increasing pressure with external heat supplied only to the vaporization stage having the highest pressure. Control of vaporization in the lower pressure stages is effected by passing a minor portion of the vapors from the highest pressure stage to the lowest pressure stage. A high temperature vacuum flash vaporization zone may follow the high pressure vaporization stage with external heat supplied to the vacuum flash vaporization zone.

  12. Control of solvent evaporation in hen egg white lysozyme crystallization

    NASA Technical Reports Server (NTRS)

    Wilson, L. J.; Suddath, F. L.

    1992-01-01

    An investigation of the role of solvent evaporation in tetragonal lysozyme crystallization was preformed with a device that employs N2(g) to control the evaporation of solvent from a micro-volume crystallization hanging drop. The number of crystals was found to vary with the rate at which the final supersaturation level was achieved. It was found that the more rapid the approach to supersaturation the larger the number of crystals. Accordingly, the crystals reached a smaller terminal size. Elongation of the (110) face parallel to the four-fold axis was observed with the slower evaporation rates.

  13. SAGE--SOLVENT ALTERNATIVES GUIDE

    EPA Science Inventory

    SAGE is a comprehensive guide designed to provide pollution prevention information on solvent and process alternatives for parts cleaning and degreasing. SAGE does not recommend any ozone depleting chemicals. SAGE was developed by the Surface Cleaning Program at Research Triang...

  14. SOLV-DB: Solvents Data

    DOE Data Explorer

    SOLV-DB provides a specialized mix of information on commercially available solvents. The development of the database was funded under the Strategic Environmental Research and Development Program (SERDP) with funds from EPA and DOE's Office of Industrial Technologies in EE. The information includes: • Health and safety considerations involved in choosing and using solvents • Chemical and physical data affecting the suitability of a particular solvent for a wide range of potential applications • Regulatory responsibilities, including exposure and effluent limits, hazard classification status with respect to several key statutes, and selected reporting requirements • Environmental fate data, to indicate whether a solvent is likely to break down or persist in air or water, and what types of waste treatment techniques may apply to it • CAS numbers (from Chemical Abstracts Service) and Sax Numbers (from Sax, et.al., Dangerous Properties of Industrial Materials) Supplier Information See help information at http://solvdb.ncms.org/welcome.htm (Specialized Interface)

  15. ON-SITE SOLVENT RECOVERY

    EPA Science Inventory

    This study evaluated the product quality, waste reduction/pollution prevention, and economic aspects of three technologies for onsite solvent recovery: atmospheric batch distillation, vacuum heat-pump distillation, and low-emission vapor degreasing. The atmospheric and vacuum ...

  16. Overview of Supported Employment.

    ERIC Educational Resources Information Center

    Rusch, Frank R.; Hughes, Carolyn

    1989-01-01

    This review defines supported employment, presents a rationale for it, describes four types of placement models, outlines supported employment program components, and analyzes effectiveness and populations served. The contributions of applied behavior analysis to supported employment are examined. (JDD)

  17. Employers' Views on Youth Literacy and Employability

    ERIC Educational Resources Information Center

    Macey, Emma

    2013-01-01

    This report looks at whether employers think schools are equipping young people with the literacy skills required for the workplace. It is primarily based on secondary literature sources and introductory conversations with a small sample of key employers and agencies. A complementary report presents evidence on young people's views on literacy and…

  18. Solvent/Non-Solvent Sintering To Make Microsphere Scaffolds

    NASA Technical Reports Server (NTRS)

    Laurencin, Cato T.; Brown, Justin L.; Nair, Lakshmi

    2011-01-01

    A solvent/non-solvent sintering technique has been devised for joining polymeric microspheres to make porous matrices for use as drug-delivery devices or scaffolds that could be seeded with cells for growing tissues. Unlike traditional sintering at elevated temperature and pressure, this technique is practiced at room temperature and pressure and, therefore, does not cause thermal degradation of any drug, protein, or other biochemical with which the microspheres might be loaded to impart properties desired in a specific application. Also, properties of scaffolds made by this technique are more reproducible than are properties of comparable scaffolds made by traditional sintering. The technique involves the use of two miscible organic liquids: one that is and one that is not a solvent for the affected polymer. The polymeric microspheres are placed in a mold having the size and shape of the desired scaffold, then the solvent/non-solvent mixture is poured into the mold to fill the void volume between the microspheres, then the liquid mixture is allowed to evaporate. Some of the properties of the resulting scaffold can be tailored through choice of the proportions of the liquids and the diameter of the microspheres.

  19. Regeneration of AlH3 studied with Raman and Infrared Spectroscopy

    NASA Astrophysics Data System (ADS)

    Lacina, David; Wegrzyn, J.; Reilly, J. J.; Graetz, Jason

    2010-03-01

    Aluminum hydride compounds are known to exhibit a 10% by weight hydrogen storage capacity that makes them suited for technologies that require hydrogen as a fuel. The current challenge associated with this material is how to regenerate the hydride from the spent fuel and H2 gas. We employ a two-step process to regenerate the hydride compound which first requires the formation of a stable aluminum hydride adduct using a tertiary amine. This is followed by a second step consisting of adduct separation and hydride recovery, involving transamination to create a less stable adduct. We present results which show that alane-amines can be formed by hydrogenation of catalyzed aluminum in a solvent at low pressures using one of several tertiary amines. Raman and infrared spectroscopy was performed on the products of these reactions to better understand the structure of the alane amines that are formed, as well as the hydrogenation reactions that take place. A vibrational analysis of the regeneration products performed with Raman and infrared spectroscopy is presented and will help clarify the molecular and vibrational structures of these alane amine adducts.

  20. Computational comparison of oxidation stability: Solvent/salt monomers vs solvent-solvent/salt pairs

    NASA Astrophysics Data System (ADS)

    Kim, Dong Young; Park, Min Sik; Lim, Younhee; Kang, Yoon-Sok; Park, Jin-Hwan; Doo, Seok-Gwang

    2015-08-01

    A fundamental understanding of the anodic stabilities of electrolytes is important for the development of advanced high-voltage electrolytes. In this study, we calculated and systematically compared the oxidation stabilities of monomeric solvents and anions, and bimolecular solvent-solvent and anion-solvent systems that are considered to be high-voltage electrolyte components, using ab initio calculations. Oxidation stabilities of solvent or anion monomers without considering specific solvation molecules cannot represent experimental oxidation stabilities. The oxidation of electrolytes usually forms neutral or cationic radicals, which immediately undergo further reactions stabilizing the products. Oxidatively driven intermolecular reactions are the main reason for the lower oxidation stabilities of electrolytes compared with those of monomeric compounds. Electrolyte components such as tetramethylene sulfone (TMS), ethyl methyl sulfone (EMS), bis(oxalate)borate (BOB-), and bis(trifluoromethane)sulfonamide (TFSI-) that minimize such intermolecular chemical reactions on oxidation can maintain the oxidation stabilities of monomers. In predictions of the theoretical oxidation stabilities of electrolytes, simple comparisons of highest occupied molecular orbital energies can be misleading, even if microsolvation or bulk clusters are considered. Instead, bimolecular solvent complexes with a salt anion should be at least considered in oxidation calculations. This study provides important information on fundamental and applied aspects of the development of electrolytes.

  1. Solvent viscosity dependence for enzymatic reactions

    NASA Astrophysics Data System (ADS)

    Sitnitsky, A. E.

    2008-09-01

    A mechanism for relationship of solvent viscosity with reaction rate constant at enzyme action is suggested. It is based on fluctuations of electric field in enzyme active site produced by thermally equilibrium rocking (crankshaft motion) of the rigid plane (in which the dipole moment ≈3.6 D lies) of a favourably located and oriented peptide group (or may be a few of them). Thus the rocking of the plane leads to fluctuations of the electric field of the dipole moment. These fluctuations can interact with the reaction coordinate because the latter in its turn has transition dipole moment due to separation of charges at movement of the reacting system along it. The rocking of the plane of the peptide group is sensitive to the microviscosity of its environment in protein interior and the latter is a function of the solvent viscosity. Thus we obtain an additional factor of interrelationship for these characteristics with the reaction rate constant. We argue that due to the properties of the crankshaft motion the frequency spectrum of the electric field fluctuations has a sharp resonance peak at some frequency and the corresponding Fourier mode can be approximated as oscillations. We employ a known result from the theory of thermally activated escape with periodic driving to obtain the reaction rate constant and argue that it yields reliable description of the pre-exponent where the dependence on solvent viscosity manifests itself. The suggested mechanism is shown to grasp the main feature of this dependence known from the experiment and satisfactorily yields the upper limit of the fractional index of a power in it.

  2. Student Employment Manuals.

    ERIC Educational Resources Information Center

    Russell, Thyra K.

    1995-01-01

    Discusses the information on academic library practices provided in student employment manuals. Highlights include the mission statement, expectations of employment, enrollment and eligibility requirements, employment eligibility verification, application form, the hiring process, program policies, release of employment verification information;…

  3. Learning, Labour and Employability

    ERIC Educational Resources Information Center

    Ball, Malcolm J.

    2009-01-01

    Public policy in the UK has adopted employability to define the relationship of globalisation, work and learning. This article claims that employability serves the interests of capital. It helps capital to exercise its domination/hegemony over labour and employs a redefined vision of learning as its principal vehicle. Employability is a term that…

  4. Coal liquefaction process with enhanced process solvent

    DOEpatents

    Givens, Edwin N.; Kang, Dohee

    1984-01-01

    In an improved coal liquefaction process, including a critical solvent deashing stage, high value product recovery is improved and enhanced process-derived solvent is provided by recycling second separator underflow in the critical solvent deashing stage to the coal slurry mix, for inclusion in the process solvent pool.

  5. Method of treating radioactively contaminated solvent waste

    SciTech Connect

    Jablonski, W.; Mallek, H.; Plum, W.

    1981-07-07

    A method of and apparatus for treating radioactively contaminated solvent waste are claimed. The solvent waste is supplied to material such as peat, vermiculite, diaton, etc. This material effects the distribution or dispersion of the solvent and absorbs the foreign substances found in the solvent waste. Air or an inert gas flows through the material in order to pick up the solvent portions which are volatile as a consequence of their vapor pressure. The thus formed gas mixture, which includes air or inert gas and solvent portions, is purified in a known manner by thermal, electrical, or catalytic combustion of the solvent portions.

  6. DOE solvent handbook information sheet

    SciTech Connect

    Chavez, A.A.

    1992-01-01

    Solvents and cleaners are used in the Department of Defense (DOD) and the Department of Energy-Defense Program (DOE-DP) maintenance facilities for removing wax, grease, oil, carbon, machining fluids, solder fluxes, mold releases, and other contaminants before repairing or electroplating parts. Private industry also uses cleaners and degreasers for surface preparation of various metals. Growing environmental and worker safety concerns have brought attention to these solvents and cleaners, most of which are classified as toxic. Tightening government regulations have already excluded the use of some chemicals, and restrict the use of various halogenated hydrocarbons because of their atmospheric-ozone depleting effects, as well as their cancer-related risks. As a result, a program was established to develop an efficient, easily accessible, electronic solvent utilization handbook. This is being accomplished by: (1) identifying solvents (alternatives) that are not currently restricted by government regulations for use DOE-DP facilities, and private industry, (2) evaluating their cleaning performance, (3) evaluating their corrosivity, (4) evaluating their air emissions, (5) evaluating the possibility of recycling or recovering all or portions of the alternative degreasers, (6) testing substitute solvents compatibility with non-metallic materials, (7) inputting all of the data gathered (including previous biodegradability information) into a database, and (8) developing a methodology for efficient, widespread access to the data base information system.

  7. DOE solvent handbook information sheet

    SciTech Connect

    Chavez, A.A.

    1992-05-01

    Solvents and cleaners are used in the Department of Defense (DOD) and the Department of Energy-Defense Program (DOE-DP) maintenance facilities for removing wax, grease, oil, carbon, machining fluids, solder fluxes, mold releases, and other contaminants before repairing or electroplating parts. Private industry also uses cleaners and degreasers for surface preparation of various metals. Growing environmental and worker safety concerns have brought attention to these solvents and cleaners, most of which are classified as toxic. Tightening government regulations have already excluded the use of some chemicals, and restrict the use of various halogenated hydrocarbons because of their atmospheric-ozone depleting effects, as well as their cancer-related risks. As a result, a program was established to develop an efficient, easily accessible, electronic solvent utilization handbook. This is being accomplished by: (1) identifying solvents (alternatives) that are not currently restricted by government regulations for use DOE-DP facilities, and private industry, (2) evaluating their cleaning performance, (3) evaluating their corrosivity, (4) evaluating their air emissions, (5) evaluating the possibility of recycling or recovering all or portions of the alternative degreasers, (6) testing substitute solvents compatibility with non-metallic materials, (7) inputting all of the data gathered (including previous biodegradability information) into a database, and (8) developing a methodology for efficient, widespread access to the data base information system.

  8. Helpful hints for physical solvent absorption

    SciTech Connect

    Wolfer, W.

    1982-11-01

    Review of experience with natural gas treatment using physical solvents points to design and operating suggestions. Experiences with three plants using either Selexol or Sepasolv MPE solvent shows that both solvents perform well. The solvents offer economical and problem-free purification of natural gas. The Sepasolv MPE and Selexol solvents are very similar in chemical structure and physical properties. Thus, their application range is almost similar. An exchange is possible in most plants without equipment modification and/or process data.

  9. [Exposure to solvents and tardy epilepsy: 2 clinical cases].

    PubMed

    Bernardini, P; Scoppetta, C

    1992-01-01

    Organic solvents (OS) are widely used in industry and craft work. The neurotoxic effects of OS are well known in occupational exposure occurring in poor industrial hygiene conditions. There has been interest recently in a possible epileptogenic effect of OS exposure. Two cases are reported of late onset epilepsy observed in workers heavily exposed to OS. Case 1 was a 27-year-old male painter employed in a car body repair workshop. Solvent exposure was high for a few months because after his regular work, the man continued working as a car body painter in his own private concern. After a period of weakness and headache, probably indicating an excessive solvent absorption, he suffered two generalized paroxysmal seizures during sleep which necessitated hospitalization and continuous treatment with barbiturates. Case 2 was a 44-year-old male painter in a road advertising billboard factory who was continuously exposed to OS. Ten years previously he had been exposed to accidental massive inhalation of solvent vapours while opening a drum of solvents for coloured paint. Acute solvent poisoning followed and seven weeks later he suffered several epileptic episodes associated with typical EEG alterations; for many years, however, treatment was ineffective. In both cases there was neither a history of neurologic disease nor any other neurologic dysfunctions and the results of comprehensive neuroradiological studies were normal. Evidence exists of a chronological connection between high exposure to paint solvents and clinical evidence of late onset epilepsy, but it is not possible to identify a definite causal relationship.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1528164

  10. Proceedings of ISEC 2008, International Solvent Extraction Conference - Solvent Extraction: Fundamentals to Industrial Applications

    SciTech Connect

    Moyer, Bruce A.

    2008-07-01

    The North American industry has employed major solvent-extraction processes to support a wide range of separations including but not limited to chemical, metallurgical, nuclear, biochemical, pharmaceutical, and petroleum applications. The knowledge enabling these separations has been obtained through fundamental studies in academe, government and industry. The International Solvent Extraction Conferences have been and continue to be a major gathering of scientists, engineers, operators, and vendors from around the world, who present new findings since the last meeting, exchange ideas, make business contacts, and conduct collegial discussions. The ISEC 2008 program emphasizes fundamentals to industrial applications of solvent extraction, particularly how this broad spectrum of activities is interconnected and has led to the implementation of novel processes. The oral and poster sessions have been organized into seven topics: Fundamentals; Novel Reagents, Materials and Techniques; Nuclear Fuel Reprocessing; Hydrometallurgy and Metals Extraction; Analytical and Preparative Applications; Biotechnology, Pharmaceuticals, Life-Science Products, and Organic Products; and Process Chemistry and Engineering. Over 350 abstracts were received, resulting in more than 260 manuscripts published in these proceedings. Five outstanding plenary presentations have been identified, with five parallel sessions for oral presentations and posters. In recognition of the major role solvent extraction (SX) plays in the hydrometallurgical and nuclear industries, these proceedings begin with sections focusing on hydrometallurgy, process chemistry, and engineering. More fundamental topics follow, including sections on novel reagents, materials, and techniques, featuring novel applications in analytical and biotechnology areas. Despite the diversity of topics and ideas represented, however, the primary focus of the ISEC community continues to be metals extraction. Four papers from these

  11. Solvent and media effects on the photophysics of naphthoxazole derivatives.

    PubMed

    Curitol, Manuel; Ragas, Xavier; Nonell, Santi; Pizarro, Nancy; Encinas, María V; Rojas, Pedro; Zanocco, Renzo P; Lemp, Else; Günther, Germán; Zanocco, Antonio L

    2013-01-01

    The photophysical properties of 2-phenyl-naphtho[1,2-d][1,3]oxazole, 2(4-N,N-dimethylaminophenyl)naphtho[1,2-d][1,3]oxazole and 2(4-N,N-diphenylaminophenyl) naphtho[1,2-d][1,3]oxazole were studied in a series of solvents. UV-Vis absorption spectra are insensitive to solvent polarity whereas the fluorescence spectra in the same solvent set show an important solvatochromic effect leading to large Stokes shifts. Linear solvation energy relationships were employed to correlate the position of fluorescence spectra maxima with microscopic empirical solvent parameters. This study indicates that important intramolecular charge transfer takes place during the excitation process. In addition, an analysis of the solvatochromic behavior of the UV-Vis absorption and fluorescence spectra in terms of the Lippert-Mataga equation shows a large increase in the excited-state dipole moment, which is also compatible with the formation of an intramolecular charge-transfer excited state. We propose both naphthoxazole derivatives as suitable fluorescent probes to determine physicochemical microproperties in several systems and as dyes in dye lasers; consequence of their high fluorescence quantum yields in most solvents, their large molar absorption coefficients, with fluorescence lifetimes in the range 1-3 ns as well as their high photostability. PMID:23834078

  12. Solvent sensitive polymer composite structures

    NASA Astrophysics Data System (ADS)

    Chiappini, A.; Armellini, C.; Carpentiero, A.; Minati, L.; Righini, G. C.; Ferrari, M.

    2013-11-01

    In this paper we describe a composite system based on polystyrene colloidal nanoparticles assembled and embedded in an elastomeric matrix (polymer colloidal crystal, PCC), in the specific we have designed a PCC structure which displays an iridescent green color that can be attributed to the photonic crystal effect. This effect has been exploited to create a chemical sensor, in fact optical measurements have evidenced that the composite structure presents a different optical response as a function of the solvent applied on the surface. In particular we have demonstrated that the PCC possess, for specific solvents: (i) high sensitivity, (ii) fast response (less than 1s), and (iii) reversibility of the signal change. Finally preliminary results on the PCC have shown that this system can be also used as optical writing substrate using a specific solvent as ink, moreover an erasing procedure is also reported and discussed.

  13. Solvent reorganization of electron transitions in viscous solvents

    SciTech Connect

    Ghorai, Pradip K.; Matyushov, Dmitry V.

    2006-04-14

    We develop a model of electron transfer reactions at conditions of nonergodicity when the time of solvent relaxation crosses the observation time window set up by the reaction rate. Solvent reorganization energy of intramolecular electron transfer in a charge-transfer molecule dissolved in water and acetonitrile is studied by molecular dynamics simulations at varying temperatures. We observe a sharp decrease of the reorganization energy at a temperature identified as the temperature of structural arrest due to cage effect, as discussed by the mode-coupling theory. This temperature also marks the onset of the enhancement of translational diffusion relative to rotational relaxation signaling the breakdown of the Stokes-Einstein relation. The change in the reorganization energy at the transition temperature reflects the dynamical arrest of the slow, collective relaxation of the solvent related to the relaxation of the solvent dipolar polarization. An analytical theory proposed to describe this effect agrees well with both the simulations and experimental Stokes shift data. The theory is applied to the analysis of charge-transfer kinetics in a low-temperature glass former. We show that the reorganization energy is substantially lower than its equilibrium value for the low-temperature portion of the data. The theory predicts the possibility of discontinuous changes in the dependence of the electron transfer rate on the free energy gap when the reaction switches between ergodic and nonergodic regimes.

  14. Solvent diffusion into fluoropolymer membranes

    SciTech Connect

    Aminabhavi, T.M.; Munnolli, R.S.

    1993-12-31

    Solvent diffusion in polymers is important to the physical properties of the material from processing to end-use and shelf-life. Many aspects of diffusion in polymers have been studied using indirect and direct methods. Du Pont`s fluoropolymers are known for their excellent resistance to a variety of organic solvents. This paper describes the measurement of diffusion coefficients and the derived thermodynamic quantities on four different fluoropolymer membranes with several esters. This information is interpreted in terms of the molecular organization and phase structure. Diffusion coefficients are sensitive to structural changes as well as binding and association phenomena.

  15. Theoretical study of solvent effects on the coil-globule transition

    NASA Astrophysics Data System (ADS)

    Polson, James M.; Opps, Sheldon B.; Abou Risk, Nicholas

    2009-06-01

    The coil-globule transition of a polymer in a solvent has been studied using Monte Carlo simulations of a single chain subject to intramolecular interactions as well as a solvent-mediated effective potential. This solvation potential was calculated using several different theoretical approaches for two simple polymer/solvent models, each employing hard-sphere chains and hard-sphere solvent particles as well as attractive square-well potentials between some interaction sites. For each model, collapse is driven by variation in a parameter which changes the energy mismatch between monomers and solvent particles. The solvation potentials were calculated using two fundamentally different methodologies, each designed to predict the conformational behavior of polymers in solution: (1) the polymer reference interaction site model (PRISM) theory and (2) a many-body solvation potential (MBSP) based on scaled particle theory introduced by Grayce [J. Chem. Phys. 106, 5171 (1997)]. For the PRISM calculations, two well-studied solvation monomer-monomer pair potentials were employed, each distinguished by the closure relation used in its derivation: (i) a hypernetted-chain (HNC)-type potential and (ii) a Percus-Yevick (PY)-type potential. The theoretical predictions were each compared to results obtained from explicit-solvent discontinuous molecular dynamics simulations on the same polymer/solvent model systems [J. Chem. Phys. 125, 194904 (2006)]. In each case, the variation in the coil-globule transition properties with solvent density is mostly qualitatively correct, though the quantitative agreement between the theory and prediction is typically poor. The HNC-type potential yields results that are more qualitatively consistent with simulation. The conformational behavior of the polymer upon collapse predicted by the MBSP approach is quantitatively correct for low and moderate solvent densities but is increasingly less accurate for higher densities. At high solvent densities

  16. 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

  17. NATURAL ATTENUATION OF CHLORINATED SOLVENTS

    EPA Science Inventory

    The protocol will simply describe in detail, with references and illustrations, the approach currently used by staff of the SPRD to evaluate natural attenuation of chlorinated solvents in ground water. Staff of SPRD, and staff of the Air Force Center for environmental excellence...

  18. Nanopapers for organic solvent nanofiltration.

    PubMed

    Mautner, A; Lee, K-Y; Lahtinen, P; Hakalahti, M; Tammelin, T; Li, K; Bismarck, A

    2014-06-01

    Would it not be nice to have an organic solvent nanofiltration membrane made from renewable resources that can be manufactured as simply as producing paper? Here the production of nanofiltration membranes made from nanocellulose by applying a papermaking process is demonstrated. Manufacture of the nanopapers was enabled by inducing flocculation of nanofibrils upon addition of trivalent ions. PMID:24752201

  19. Improved Purex solvent scrubbing methods

    SciTech Connect

    Mailen, J.C.; Tallent, O.K.

    1984-01-01

    Studies of hydrazine and hydroxylamine salts as solvent scrubbing agents that can be decomposed into gases are summarized. Results from testing of countercurrent scrubbers and solid sorber columns that produce lesser amounts of permanent salts are reported. The status of studies of the acid-degradation of paraffin diluent and the options for removal of long-chain organic acids is given.

  20. Physical solvent for gas sweetening

    SciTech Connect

    Ferrin, C. R.; Manning, W. P.

    1984-11-27

    This invention relates to a novel solvent, N-2-methoxyethyl-2-pyrrolidone, that can be used in two ways. First, in the pure or undiluted form, it absorbs hydrogen sulfide and other sulfurous gases selectively and simultaneously dries the gas. Second, when mixed with an alkanolamine and water, it is a superior absorbent of mercaptans, sulfides, and disulfides, and removes acid gases.

  1. A generic analysis of energy use and solvent selection for CO2 separation from post-combustion flue gases

    USGS Publications Warehouse

    Lu, Y.; Chen, S.; Rostam-Abadi, M.

    2008-01-01

    A thermodynamic calculation was performed to determine the theoretical minimum energy used to separate CO2 from a coal combustion flue gas in a typical adsorption-desorption system. Under ideal conditions, the minimum energy required to separate CO2 from post-combustion flue gas and produce pure CO2 at 1 atmospheric pressure was only about 1183 kJ/kg CO2. This amount could double with the addition of the driving forces of mass and heat transfer and the adverse impacts of absorption heat release on adsorption capacity. Thermodynamic analyses were also performed for the aqueous amine-based absorption process. Two CO2 reaction mechanisms, the carbamate formation reaction with primary/secondary amines and the CO2 hydration reaction with tertiary amines, were included in the absorption reaction. The reaction heat, sensible heat, and stripping heat were all important to the total heat requirement. The heat use of an ideal tertiary amine amounted to 2786 kJ/kg, compared to 3211 kJ/kg for an ideal primary amine. The heat usage of an ideal amine was about 20% lower than that of commercially available amines. Optimizing the absorption process configuration could further reduce energy use. This is an abstract of a paper presented at the 2008 AIChE Spring National Meeting (New Orleans, LA 4/6-10/2008).

  2. 1987 Employment Outlook.

    ERIC Educational Resources Information Center

    Chemical and Engineering News, 1986

    1986-01-01

    Traces the decline in employment opportunities for chemists and chemical engineers. Discusses the employment outlook for 1987. Includes information on continuing education opportunities for chemical professionals already employed, the drop in demand for chemistry professionals, the decline in salaries of bachelor's degree chemists, and several…

  3. Graduate Identity and Employability

    ERIC Educational Resources Information Center

    Hinchliffe, Geoffrey William; Jolly, Adrienne

    2011-01-01

    This paper develops the concept of graduate identity as a way of deepening the understanding of graduate employability. It does this through presenting research in which over 100 employers in East Anglia were asked to record their perceptions of graduates in respect of their employability. The findings suggest a composite and complex graduate…

  4. 1982 Employment Outlook.

    ERIC Educational Resources Information Center

    Chemical and Engineering News, 1981

    1981-01-01

    Presents highlights of Chemical and Engineering News survey of the employment picture for chemical professionals. Focuses on the question of needing a Ph.D.; employment opportunities; salaries; and career planning, including the names and addresses of many employers of chemists and chemical engineers. (SK)

  5. Replacement solvents for use in chemical synthesis

    DOEpatents

    Molnar, Linda K.; Hatton, T. Alan; Buchwald, Stephen L.

    2001-05-15

    Replacement solvents for use in chemical synthesis include polymer-immobilized solvents having a flexible polymer backbone and a plurality of pendant groups attached onto the polymer backbone, the pendant groups comprising a flexible linking unit bound to the polymer backbone and to a terminal solvating moiety. The polymer-immobilized solvent may be dissolved in a benign medium. Replacement solvents for chemical reactions for which tetrahydrofuran or diethyl may be a solvent include substituted tetrahydrofurfuryl ethers and substituted tetrahydro-3-furan ethers. The replacement solvents may be readily recovered from the reaction train using conventional methods.

  6. Comparison of Fluor Solvent and Selexol processes

    SciTech Connect

    Bucklin, R.W.; Schendel, R.L.

    1984-09-01

    Physical solvent processes can be useful for acid gas removal applications. The necessity for screening physical solvent characteristics to eliminate those solvents that are unsuitable or noncompetitive for a particular application is discussed. The Fluor Solvent and Selexol processes are compared. Selexol has an advantage over other solvents in oil applications involving H/sub 2/S and CO/sub 2/ removal in hydrocarbon systems. Fluor Solvent and Selexol have an experience advantage over other processes in applications for CO/sub 2/ removal only.

  7. 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…

  8. Dipolar correlations in structured solvents under nanoconfinement.

    PubMed

    Buyukdagli, Sahin; Blossey, Ralf

    2014-06-21

    We study electrostatic correlations in structured solvents confined to nanoscale systems. We derive variational equations of Netz-Orland type for a model liquid composed of finite size dipoles. These equations are solved for both dilute solvents and solvents at physiological concentrations in a slit nanopore geometry. Correlation effects are of major importance for the dielectric reduction and anisotropy of the solvent resulting from dipole image interactions and also lead to a reduction of van der Waals attractions between low dielectric bodies. Finally, by comparison with other recently developed self-consistent theories and experiments, we scrutinize the effect of solvent-membrane interactions on the differential capacitance of the charged liquid in contact with low dielectric substrates. The interfacial solvent depletion driven by solvent-image interactions plays the major role in the observed low values of the experimental capacitance data, while non-locality associated with the extended charge structure of solvent molecules only brings a minor contribution. PMID:24952564

  9. Wash solvent reuse in paint production

    SciTech Connect

    Parsons, A.B.; Heater, K.J.; Olfenbuttel, R.F.

    1994-04-01

    The project evaluated solvent used to clean paint manufacture equipment for its utility in production of subsequent batches of solvent-borne paint. Reusing wash solvent would reduce the amount of solvent disposed of as waste. The evaluation of this wash-solvent recovery technology was conducted by Battelle Memorial Institute for the Pollution Prevention Research Branch of the U.S. Environmental Protection Agency. The evaluation was conducted with the cooperation and assistance of Vanex Color, Inc. The product quality, waste reduction/pollution prevention, and economic impacts of this technology change, as it has been implemented by Vanex, were examined. Two batches of a solvent-borne alkyd house paint were prepared at Vanex--one batch made with 100%-new solvent and the other with 30%-wash solvent--and sampled for laboratory analysis at Battelle.

  10. Solvent pretreatment of feed coal for briquetting

    SciTech Connect

    Martin, D.M.; Miller, M.R.

    1980-11-25

    Solvent pretreating of coal fines prior to briquetting results in coal briquettes which have no added binder and which will withstand weathering conditions better than binder containing briquettes. The solvents are generally described as organic Lewis base solvents which are capable of electron donor action, and include among others, acetone, methyl ethyl ketone, and ethylene diamine.

  11. Firing of pulverized solvent refined coal

    DOEpatents

    Derbidge, T. Craig; Mulholland, James A.; Foster, Edward P.

    1986-01-01

    An air-purged burner for the firing of pulverized solvent refined coal is constructed and operated such that the solvent refined coal can be fired without the coking thereof on the burner components. The air-purged burner is designed for the firing of pulverized solvent refined coal in a tangentially fired boiler.

  12. Solvent Extraction of Furfural From Biomass

    NASA Technical Reports Server (NTRS)

    Humphrey, M. F.

    1984-01-01

    Solvent-extraction method reduces energy required to remove furfural produced during acid hydrolysis of biomass. Acid hydrolysis performed in vessel containing both solvents and reacting ingredients. With intimate contact between solvents and aqueous hydrolyis liqour, furfural removed form liquor almost as fast as it forms.

  13. The hype with ionic liquids as solvents

    NASA Astrophysics Data System (ADS)

    Kunz, Werner; Häckl, Katharina

    2016-09-01

    In this mini review, we give our personal opinion about the present state of the art concerning Ionic Liquids, proposed as alternative solvents. In particular, we consider their different drawbacks and disadvantages and discuss the critical aspects of the research of Ionic Liquids as solvents. Finally, we point out some aspects on potentially promising Ionic Liquid solvents.

  14. Solvent cleaning system and method for removing contaminants from solvent used in resin recycling

    DOEpatents

    Bohnert, George W.; Hand, Thomas E.; DeLaurentiis, Gary M.

    2009-01-06

    A two step solvent and carbon dioxide based system that produces essentially contaminant-free synthetic resin material and which further includes a solvent cleaning system for periodically removing the contaminants from the solvent so that the solvent can be reused and the contaminants can be collected and safely discarded in an environmentally safe manner.

  15. Behavioural evaluation of workers exposed to mixtures of organic solvents.

    PubMed Central

    Maizlish, N A; Langolf, G D; Whitehead, L W; Fine, L J; Albers, J W; Goldberg, J; Smith, P

    1985-01-01

    Reports from Scandinavia have suggested behavioural impairment among long term workers exposed to solvents below regulatory standards. A cross sectional study of behavioural performance was conducted among printers and spray painters exposed to mixtures of organic solvents to replicate the Scandinavian studies and to examine dose-response relationships. Eligible subjects consisted of 640 hourly workers from four midwestern United States companies. Of these, 269 responded to requests to participate and 240 were selected for study based on restrictions for age, sex, education, and other potentially confounding variables. The subjects tested had been employed on average for six years. Each subject completed an occupational history, underwent a medical examination, and completed a battery of behavioural tests. These included the Fitts law psychomotor task, the Stroop colour-word test, the Sternberg short term memory scanning test, the short term memory span test, and the continuous recognition memory test. Solvent exposure for each subject was defined as an exposed or non-exposed category based on a plant industrial hygiene walk-through and the concentration of solvents based on an analysis of full shift personal air samples by gas chromatography. The first definition was used to maintain consistency with Scandinavian studies, but the second was considered to be more accurate. The average full shift solvent concentration was 302 ppm for the printing plant workers and 6-13 ppm for the workers at other plants. Isopropanol and hexane were the major components, compared with toluene in Scandinavian studies. Performance on behavioural tests was analysed using multiple linear regression with solvent concentration as an independent variable. Other relevant demographic variables were also considered for inclusion. No significant (p greater than 0.05) relation between solvent concentration and impairment on any of the 10 behavioural variables was observed after controlling for

  16. 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.

  17. Critical Casimir interactions and colloidal self-assembly in near-critical solvents.

    PubMed

    Tasios, Nikos; Edison, John R; van Roij, René; Evans, Robert; Dijkstra, Marjolein

    2016-08-28

    A binary solvent mixture close to critical demixing experiences fluctuations whose correlation length, ξ, diverges as the critical point is approached. The solvent-mediated (SM) interaction that arises between a pair of colloids immersed in such a near-critical solvent can be long-ranged and this so-called critical Casimir interaction is well-studied. How a (dense) suspension of colloids will self-assemble under these conditions is poorly understood. Using a two-dimensional lattice model for the solvent and hard disks to represent the colloids, we perform extensive Monte Carlo simulations to investigate the phase behaviour of this model colloidal suspension as a function of colloid size and wettability under conditions where the solvent reservoir is supercritical. Unlike most other approaches, where the solvent is modelled as an implicit background, our model employs an explicit solvent and treats the suspension as a ternary mixture. This enables us to capture important features, including the pronounced fractionation of the solvent in the coexisting colloidal phases, of this complex system. We also present results for the partial structure factors; these shed light on the critical behaviour in the ternary mixture. The degree to which an effective two-body pair potential description can describe the phase behaviour and structure of the colloidal suspension is discussed briefly. PMID:27586941

  18. Phase behavior and second osmotic virial coefficient for competitive polymer solvation in mixed solvent solutions

    NASA Astrophysics Data System (ADS)

    Dudowicz, Jacek; Freed, Karl F.; Douglas, Jack F.

    2015-11-01

    We apply our recently developed generalized Flory-Huggins (FH) type theory for the competitive solvation of polymers by two mixed solvents to explain general trends in the variation of phase boundaries and solvent quality (quantified by the second osmotic virial coefficient B 2 ) with solvent composition. The complexity of the theoretically predicted miscibility patterns for these ternary mixtures arises from the competitive association between the polymer and the solvents and from the interplay of these associative interactions with the weak van der Waals interactions between all components of the mixture. The main focus here lies in determining the influence of the free energy parameters for polymer-solvent association (solvation) and the effective FH interaction parameters {χαβ} (driving phase separation) on the phase boundaries (specifically the spinodals), the second osmotic virial coefficient B 2 , and the relation between the positions of the spinodal curves and the theta temperatures at which B 2 vanishes. Our classification of the predicted miscibility patterns is relevant to numerous applications of ternary polymer solutions in industrial formulations and the use of mixed solvent systems for polymer characterization, such as chromatographic separation where mixed solvents are commonly employed. A favorable comparison of B 2 with experimental data for poly(methyl methacrylate)/acetonitrile/methanol (or 1-propanol) solutions only partially supports the validity of our theoretical predictions due to the lack of enough experimental data and the neglect of the self and mutual association of the solvents.

  19. Insecticide solvents: interference with insecticidal action.

    PubMed

    Brattsten, L B; Wilkinson, C F

    1977-06-10

    Several commercial solvent mixtures commonly used as insecticide carriers in spray formulations increase by more than threefold the microsomal N-demethylation of p-chloro N-methylaniline in midgut preparations of southern army-worm (Spodoptera eridania) larvae exposed orally to the test solvents. Under laboratory conditions, the same solvent mixtures exhibit a protective action against the in vivo toxicity of the insecticide carbaryl to the larvae. The data are discussed with respect to possible solvent-insecticide interactions occurring under field conditions and, more broadly, to potential toxicological hazards of these solvents to humans. PMID:860135

  20. Batch extracting process using magneticparticle held solvents

    DOEpatents

    Nunez, Luis; Vandergrift, George F.

    1995-01-01

    A process for selectively removing metal values which may include catalytic values from a mixture containing same, wherein a magnetic particle is contacted with a liquid solvent which selectively dissolves the metal values to absorb the liquid solvent onto the magnetic particle. Thereafter the solvent-containing magnetic particles are contacted with a mixture containing the heavy metal values to transfer metal values into the solvent carried by the magnetic particles, and then magnetically separating the magnetic particles. Ion exchange resins may be used for selective solvents.

  1. Issues of Youth Employment.

    ERIC Educational Resources Information Center

    Bender, Carl M.; Petty, Gregory C.

    This document contains one of two reports presented at the Governor's National Forum on Youth Employment, May 22-23, 1980. Focusing on the issue of youth employment, this report is divided into seven sections. Section 1 discusses the high national youth unemployment rate. Section 2 describes a variety of factors pertinent to youth unemployment and…

  2. Does Supported Employment Work?

    ERIC Educational Resources Information Center

    Morgan McInnes, Melayne; Ozturk, Orgul Demet; McDermott, Suzanne; Mann, Joshua R.

    2010-01-01

    Providing employment-related services, including supported employment through job coaches, has been a priority in federal policy since the enactment of the Developmental Disabilities Assistance and Bill of Rights Act in 1984. We take advantage of a unique panel data set of all clients served by the South Carolina Department of Disabilities and…

  3. Part-Time Employment.

    ERIC Educational Resources Information Center

    Guichard, Gus; And Others

    The employment of community college instructors on a part-time basis provides the opportunity for students to study under outstanding instructors whose primary employment may be in industry or in other postsecondary institutions and permits colleges to respond better to community needs with the financial resources available to them. Along with…

  4. Discrimination in Employment.

    ERIC Educational Resources Information Center

    Kovarsky, Irving

    Intended as a guide on discrimination problems and issues for students and practitioners in the area of employment relations, this book interrelates historical, religious, economic, medical, and sociological factors surrounding racial, religious, national, sex, age, and physical and mental discrimination to explain discrimination in employment.…

  5. Addressing Employer Services.

    ERIC Educational Resources Information Center

    Perspective: Essays and Reviews of Issues in Employment Security and Employment and Training Programs, 1986

    1986-01-01

    This volume of an annual journal contains 21 articles focusing on the many services that state Employment Security (ES) agencies are providing to improve outreach to employers who pay for the programs through the dedicated revenues of the Federal Unemployment Tax Act and state benefit taxes and to improve their own staff ability to deliver…

  6. Employment Policy and Territories.

    ERIC Educational Resources Information Center

    Berthet, Thierry; Cuntigh, Philippe; Guitton, Christophe

    2002-01-01

    France's employment policy has historically been governed by a strategy of interventions aimed at specific categories of individuals, including victims of industrial restructuring, entry workers, the long-term unemployed, and the disabled. Since the 1980s, France has had the following main lines of employment policy: (1) assistance to victims of…

  7. Deep eutectic solvents as efficient solvent system for the extraction of κ-carrageenan from Kappaphycus alvarezii.

    PubMed

    Das, Arun Kumar; Sharma, Mukesh; Mondal, Dibyendu; Prasad, Kamalesh

    2016-01-20

    Three different deep eutectic solvents (DESs) prepared by the complexation of choline chloride with urea, ethylene glycol and glycerol along with their hydrated counterparts were used for the selective extraction of κ-carrageenan from Kappaphycus alvarezii. Upon comparison of the quality of the polysaccharide with the one obtained using water as extraction media as well as the one extracted using widely practiced conventional method, it was found that, the physicochemical as well as rheological properties of κ-carrageenan obtained using DESs as solvents was at par to the one obtained using conventional method and was superior in quality when compared to κ-carrageenan obtained using water as solvent. Considering the tedious nature of the extraction method employed in conventional extraction process, the DESs can be considered as suitable alternative solvents for the facile extraction of the polysaccharide directly from the seaweed. However, among the hydrated and non-hydrated DESs, the hydrated ones were found to be more effective in comparison to their non-hydrated counterparts. PMID:26572431

  8. Effect of solvents on obligately anaerobic bacteria.

    PubMed

    Rodriguez Martinez, Maria Fernanda; Kelessidou, Niki; Law, Zoe; Gardiner, John; Stephens, Gill

    2008-02-01

    Growth of Acetobacterium woodii and Clostridium sporogenes was studied in the presence of water-immiscible solvents. Nitrogen purging, vacuum distillation or distillation under nitrogen were all suitable as methods to remove oxygen from the solvents, since growth rates and yields of A. woodii were unaffected in the presence of tetradecane which had been degassed by these methods. Varying the solvent volume from 20% to 80% of the culture volume had little effect on growth rate of A. woodii. A.woodii was relatively sensitive to organic solvents since growth was inhibited by alkanes with logP(octanol/water) values below 7.1. C. sporogenes was less solvent sensitive, since it grew without inhibition when the logP of the solvent was > or = 6.6. Nevertheless, both A. woodii and C. sporogenes were more sensitive to solvent polarity than aerobic bacteria. PMID:18083050

  9. Advanced integrated solvent extraction systems

    SciTech Connect

    Horwitz, E.P.; Dietz, M.L.; Leonard, R.A.

    1997-10-01

    Advanced integrated solvent extraction systems are a series of novel solvent extraction (SX) processes that will remove and recover all of the major radioisotopes from acidic-dissolved sludge or other acidic high-level wastes. The major focus of this effort during the last 2 years has been the development of a combined cesium-strontium extraction/recovery process, the Combined CSEX-SREX Process. The Combined CSEX-SREX Process relies on a mixture of a strontium-selective macrocyclic polyether and a novel cesium-selective extractant based on dibenzo 18-crown-6. The process offers several potential advantages over possible alternatives in a chemical processing scheme for high-level waste treatment. First, if the process is applied as the first step in chemical pretreatment, the radiation level for all subsequent processing steps (e.g., transuranic extraction/recovery, or TRUEX) will be significantly reduced. Thus, less costly shielding would be required. The second advantage of the Combined CSEX-SREX Process is that the recovered Cs-Sr fraction is non-transuranic, and therefore will decay to low-level waste after only a few hundred years. Finally, combining individual processes into a single process will reduce the amount of equipment required to pretreat the waste and therefore reduce the size and cost of the waste processing facility. In an ongoing collaboration with Lockheed Martin Idaho Technology Company (LMITCO), the authors have successfully tested various segments of the Advanced Integrated Solvent Extraction Systems. Eichrom Industries, Inc. (Darien, IL) synthesizes and markets the Sr extractant and can supply the Cs extractant on a limited basis. Plans are under way to perform a test of the Combined CSEX-SREX Process with real waste at LMITCO in the near future.

  10. Solvent cavitation under solvophobic confinement.

    PubMed

    Ashbaugh, Henry S

    2013-08-14

    The stability of liquids under solvophobic confinement can tip in favor of the vapor phase, nucleating a liquid-to-vapor phase transition that induces attractive forces between confining surfaces. In the case of water adjacent to hydrophobic surfaces, experimental and theoretical evidence support confinement-mediated evaporation stabilization of biomolecular and colloidal assemblies. The macroscopic thermodynamic theory of cavitation under confinement establishes the connection between the size of the confining surfaces, interfacial free energies, and bulk solvent pressure with the critical evaporation separation and interfacial forces. While molecular simulations have confirmed the broad theoretical trends, a quantitative comparison based on independent measurements of the interfacial free energies and liquid-vapor coexistence properties has, to the best of our knowledge, not yet been performed. To overcome the challenges of simulating a large number of systems to validate scaling predictions for a three-dimensional fluid, we simulate both the forces and liquid-vapor coexistence properties of a two-dimensional Lennard-Jones fluid confined between solvophobic plates over a range of plate sizes and reservoir pressures. Our simulations quantitatively agree with theoretical predictions for solvent-mediated forces and critical evaporation separations once the length dependence of the solvation free energy of an individual confining plate is taken into account. The effective solid-liquid line tension length dependence results from molecular scale correlations for solvating microscopic plates and asymptotically decays to the macroscopic value for plates longer than 150 solvent diameters. The success of the macroscopic thermodynamic theory at describing two-dimensional liquids suggests application to surfactant monolayers to experimentally confirm confinement-mediated cavitation. PMID:23947875

  11. SOLVENT EXTRACTION PROCESS FOR PLUTONIUM

    DOEpatents

    Seaborg, G.T.

    1959-04-14

    The separation of plutonium from aqueous inorganic acid solutions by the use of a water immiscible organic extractant liquid is described. The plutonium must be in the oxidized state, and the solvents covered by the patent include nitromethane, nitroethane, nitropropane, and nitrobenzene. The use of a salting out agents such as ammonium nitrate in the case of an aqueous nitric acid solution is advantageous. After contacting the aqueous solution with the organic extractant, the resulting extract and raffinate phases are separated. The plutonium may be recovered by any suitable method.

  12. Solvent refined coal (SRC) process

    SciTech Connect

    Not Available

    1980-12-01

    This report summarizes the progress of the Solvent Refined Coal (SRC) project by The Pittsburg and Midway Coal Mining Co. at the SRC Pilot Plant in Fort Lewis, Washington and the Gulf Science and Technology Company Process Development Unit (P-99) in Harmarville, Pennsylvania, for the Department of Energy during the month of October, 1980. The Fort Lewis Pilot Plant was shut down the entire month of October, 1980 for inspection and maintenance. PDU P-99 completed two runs during October investigating potential start-up modes for the Demonstration Plant.

  13. Bifunctional anion-exchange resins with improved selectivity and exchange kinetics

    DOEpatents

    Alexandratos, Spiro D.; Brown, Gilbert M.; Bonnesen, Peter V.; Moyer, Bruce A.

    2000-01-01

    Disclosed herein are a class of anion exchange resins containing two different exchange sites with improved selectivity and sorptive capability for chemical species in solution, such as heptavalent technetium (as pertechnetate anion, TcO.sub.4.sup.-). The resins are prepared by first reacting haloalkylated crosslinked copolymer beads with a large tertiary amine in a solvent in which the resin beads can swell, followed by reaction with a second, smaller, tertiary amine to more fully complete the functionalization of the resin. The resins have enhanced selectivity, capacity, and exchange kinetics.

  14. 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

  15. Farm Employment Trends

    ERIC Educational Resources Information Center

    Rural Manpower Developments, 1973

    1973-01-01

    The heavy spring rains of 1973 led to delays and reduced acreage in planting, resulting in a sharp decline in vegetable and cotton employment. Seasonal farmworker job levels are reported by state and activity. (MS)

  16. Placement: The Employer's View.

    ERIC Educational Resources Information Center

    Teff, Donald R.

    1979-01-01

    A bank vice president reviews three barriers to the employment of handicapped persons: misunderstanding and lack of knowledge concerning the handicapped, the traditional lag between recognition of a problem and its solution, and apathy and disinterest. (CL)

  17. The solvent component of macromolecular crystals

    PubMed Central

    Weichenberger, Christian X.; Afonine, Pavel V.; Kantardjieff, Katherine; Rupp, Bernhard

    2015-01-01

    The mother liquor from which a biomolecular crystal is grown will contain water, buffer molecules, native ligands and cofactors, crystallization precipitants and additives, various metal ions, and often small-molecule ligands or inhibitors. On average, about half the volume of a biomolecular crystal consists of this mother liquor, whose components form the disordered bulk solvent. Its scattering contributions can be exploited in initial phasing and must be included in crystal structure refinement as a bulk-solvent model. Concomitantly, distinct electron density originating from ordered solvent components must be correctly identified and represented as part of the atomic crystal structure model. Herein, are reviewed (i) probabilistic bulk-solvent content estimates, (ii) the use of bulk-solvent density modification in phase improvement, (iii) bulk-solvent models and refinement of bulk-solvent contributions and (iv) modelling and validation of ordered solvent constituents. A brief summary is provided of current tools for bulk-solvent analysis and refinement, as well as of modelling, refinement and analysis of ordered solvent components, including small-molecule ligands. PMID:25945568

  18. The solvent component of macromolecular crystals.

    PubMed

    Weichenberger, Christian X; Afonine, Pavel V; Kantardjieff, Katherine; Rupp, Bernhard

    2015-05-01

    The mother liquor from which a biomolecular crystal is grown will contain water, buffer molecules, native ligands and cofactors, crystallization precipitants and additives, various metal ions, and often small-molecule ligands or inhibitors. On average, about half the volume of a biomolecular crystal consists of this mother liquor, whose components form the disordered bulk solvent. Its scattering contributions can be exploited in initial phasing and must be included in crystal structure refinement as a bulk-solvent model. Concomitantly, distinct electron density originating from ordered solvent components must be correctly identified and represented as part of the atomic crystal structure model. Herein, are reviewed (i) probabilistic bulk-solvent content estimates, (ii) the use of bulk-solvent density modification in phase improvement, (iii) bulk-solvent models and refinement of bulk-solvent contributions and (iv) modelling and validation of ordered solvent constituents. A brief summary is provided of current tools for bulk-solvent analysis and refinement, as well as of modelling, refinement and analysis of ordered solvent components, including small-molecule ligands. PMID:25945568

  19. The solvent dependent shift of the amide I band of a fully solvated peptide in methanol/water mixtures as a local probe for the solvent composition in the peptide/solvent interface

    SciTech Connect

    Gnanakaran, S

    2008-01-01

    We determine the shift and line-shape of the amide I band of a model AK-peptide from molecular dynamics (MD) simulations of the peptide dissolved in methanol/water mixtures with varying composition. The IR-spectra are determined from a transition dipole coupling exciton model. A simplified empirical model Hamiltonian is employed, taking both the effect of hydrogen bonding, as well as intramolecular vibrational coupling into account. We consider a single isolated AK-peptide in a mostly helical conformation, while the solvent is represented by 2600 methanol or water molecules, simulated for a pressure of 1 bar and a temperature of 300 K. Over the course of the simulations minor reversible conformational changes at the termini are observed, which are found to only slightly affect the calculated spectral properties. Over the entire composition range, varying from pure water to the pure methanol solvent, a monotonous blue-shift of the IR amide I band of about 8 wavenumbers is observed. The shift is found to be caused by two counter-compensating effects: An intramolecular red-shift of about 1.2 wavenumbers, due to stronger intramolecular hydrogen-bonding in a methanol-rich environment. Dominating, however, is the intermolecular solvent-dependent blue-shift of about 10 wavenumbers, being attributed to the less effective hydrogen bond donor capabilities of methanol compared to water. The importance of solvent-contribution to the IR-shift, as well as the significantly different hydrogen formation capabilities of water and methanol make the amide I band sensitive to composition changes in the local environment close the peptide/solvent interface. This allows, in principle, an experimental determination of the composition of the solvent in close proximity to the peptide surface. For the AK-peptide case they observe at low methanol concentrations a significantly enhanced methanol concentration at the peptide/solvent-interface, supposedly promoted by the partially hydrophobic

  20. Aryne Compatible Solvents are not Always Innocent.

    PubMed

    Suh, Sung-Eun; Chenoweth, David M

    2016-08-19

    Arynes are important and versatile intermediates in a variety of transformations. Commonly used solvents for aryne chemistry include acetonitrile and dichloromethane. Although rarely reported, the reactive nature of aryne intermediates makes them prone to side reactions, which sometimes involve solvent participation. Acetonitrile and dichloromethane are not always innocent solvents and can participate in aryne-based reactions. These results are presented in the context of ongoing mechanistic investigations of the triple aryne-tetrazine reaction. PMID:27486792

  1. Femtosecond dynamics in hydrogen-bonded solvents

    SciTech Connect

    Castner, E.W. Jr.; Chang, Y.J.

    1993-09-01

    We present results on the ultrafast dynamics of pure hydrogen-bonding solvents, obtained using femtosecond Fourier-transform optical-heterodyne-detected, Raman-induced Kerr effect spectroscopy. Solvent systems we have studied include the formamides, water, ethylene glycol, and acetic acid. Inertial and diffusive motions are clearly resolved. We comment on the effect that such ultrafast solvent motions have on chemical reactions in solution.

  2. Accelerated solvent extraction for natural products isolation.

    PubMed

    Mottaleb, Mohammad A; Sarker, Satyajit D

    2012-01-01

    Accelerated solvent extraction (ASE(®)), first introduced in 1995, is an automated rapid extraction technique that utilizes common solvents at elevated temperature and pressure, and thereby increases the efficiency of extraction of organic compounds from solid and semisolid matrices. ASE(®) allows extractions for sample sizes 1-100 g in minutes, reduces solvent uses dramatically, and can be applied to a wide range of matrices, including natural products. PMID:22367894

  3. Prediction of the solubility in lipidic solvent mixture: Investigation of the modeling approach and thermodynamic analysis of solubility.

    PubMed

    Patel, Shruti V; Patel, Sarsvatkumar

    2015-09-18

    Self-micro emulsifying drug delivery system (SMEDDS) is one of the methods to improve solubility and bioavailability of poorly soluble drug(s). The knowledge of the solubility of pharmaceuticals in pure lipidic solvents and solvent mixtures is crucial for designing the SMEDDS of poorly soluble drug substances. Since, experiments are very time consuming, a model, which allows for solubility predictions in solvent mixtures based on less experimental data is desirable for efficiency. Solvents employed were Labrafil® M1944CS and Labrasol® as lipidic solvents; Capryol-90®, Capryol-PGMC® and Tween®-80 as surfactants; Transcutol® and PEG-400 as co-solvents. Solubilities of both drugs were determined in single solvent systems at temperature (T) range of 283-333K. In present study, we investigated the applicability of the thermodynamic model to understand the solubility behavior of drugs in the lipiodic solvents. By using the Van't Hoff and general solubility theory, the thermodynamic functions like Gibbs free energy, enthalpy and entropy of solution, mixing and solvation for drug in single and mixed solvents were understood. The thermodynamic parameters were understood in the framework of drug-solvent interaction based on their chemical similarity and dissimilarity. Clotrimazole and Fluconazole were used as active ingredients whose solubility was measured in single solvent as a function of temperature and the data obtained were used to derive mathematical models which can predict solubility in multi-component solvent mixtures. Model dependent parameters for each drug were calculated at each temperature. The experimental solubility data of solute in mixed solvent system were measured experimentally and further correlated with the calculates values obtained from exponent model and log-linear model of Yalkowsky. The good correlation was observed between experimental solubility and predicted solubility. PMID:26092370

  4. Solvent recovery system provides timely compliance solution

    SciTech Connect

    1996-11-01

    Hoechst Celanese Corp. (Coventry, Rhode Island) faced the challenge of meeting an Environmental Protection Agency (EPA) deadline for solvent recovery within one year. The company also had to ensure that a new solvent recovery system would satisfy Rhode Island state requirements. An initial search for the required technology was fruitless. Finally, MG Industries (Saint Charles, Missouri), an industrial gas supplier, was chosen for the job. Using CRYOSOLV, as the waste stream cools in the cryogenic condenser (heat exchanger), the solvents condense at temperatures below the dewpoint. The recovered solvent can be recycled into the process, while clean gas is vented to the atmosphere.

  5. Chronic solvent abuse. 1. Cognitive sequelae.

    PubMed

    Zur, J; Yule, W

    1990-01-01

    Twelve adolescent males with a history of chronic solvent abuse were compared with 12 delinquent controls on a battery of neuropsychological tests. Toluene was the active constituent most commonly abused. Solvent abusers tended to have lower overall intelligence test scores. On the Bexley Maudsley Automated Screening Test, the solvent abusers scored significantly lower on tests involving visual processing, especially the Symbol Digit Coding test. These results are cautiously interpreted as indicating that chronic solvent abuse carries an increased risk of cognitive impairment. PMID:2311197

  6. MCU MATERIALS COMPATIBILITY WITH CSSX SOLVENT

    SciTech Connect

    Fondeur, F

    2006-01-13

    The Modular Caustic-Side Solvent Extraction (CSSX) Unit (MCU) plans to use several new materials of construction not previously used with CSSX solvent. SRNL researchers tested seven materials proposed for service in seal and gasket applications. None of the materials leached detectable amounts of components into the CSSX solvent during 96 hour tests. All are judged acceptable for use based on their effect on the solvent. However, some of the materials adsorbed solvent or changed dimensions during contact with solvent. Consultation with component and material vendors with regard to performance impact and in-use testing of the materials is recommended. Polyetheretherketone (PEEK), a material selected for use in contactor bearing seals, did not gain weight or change dimensions on contact with CSSX solvent. Analysis of the solvent contacted with this material showed no impurities and the standard dispersion test gave acceptable phase separation results. The material contains a leachable hydrocarbon substance, detectable on exposed surfaces, that did not adversely contaminate the solvent within the limits of the testing. We recommend contacting the vendor to determine the source and purpose of this component, or, alternatively, pursue the infrared analysis of the PEEK in an effort to better define potential impacts.

  7. Process for hydrogenating coal and coal solvents

    DOEpatents

    Tarrer, Arthur R.; Shridharani, Ketan G.

    1983-01-01

    A novel process is described for the hydrogenation of coal by the hydrogenation of a solvent for the coal in which the hydrogenation of the coal solvent is conducted in the presence of a solvent hydrogenation catalyst of increased activity, wherein the hydrogenation catalyst is produced by reacting ferric oxide with hydrogen sulfide at a temperature range of 260.degree. C. to 315.degree. C. in an inert atmosphere to produce an iron sulfide hydrogenation catalyst for the solvent. Optimally, the reaction temperature is 275.degree. C. Alternately, the reaction can be conducted in a hydrogen atmosphere at 350.degree. C.

  8. Solvent and substrate effects on inkjet-printed dots and lines of silver nanoparticle colloids

    NASA Astrophysics Data System (ADS)

    Shin, Kwon-Yong; Lee, Sang-Ho; Oh, Je Hoon

    2011-04-01

    The shape changes of inkjet-printed dots and lines were investigated by varying the primary solvent of nanosilver colloids, surface wettability and substrate temperature. The morphological changes in dots and lines in array patterns due to the interaction between neighboring dots or lines during evaporation was also examined for two different nanosilver colloids. In order to examine the effect of solvent evaporation rate, two different solvents with different boiling points (BP) were employed for nanosilver inks. With a fluorocarbon film coating and subsequent ultraviolet ozone (UV/O3) treatment, various surface wettability conditions were obtained on silicon (Si) wafers. Substrate temperature was varied from room temperature to 80 °C, and droplets from a 50 µm diameter nozzle were printed onto the substrate after optimizing the ejection of individual droplets. The results indicate that the shapes and sizes of dots and lines are sensitive to changes in both surface energy and substrate temperature, and the ink with a higher BP solvent produces larger dots under the same surface condition due to its slower evaporation. Dots and lines with better quality are achieved using the ink with a lower BP solvent. The morphological changes in dot and line arrays are dependent on the evaporation rate of the primary solvent as well as the distance between neighboring features. As a result, selecting a proper solvent for nanosilver ink is very crucial for controlling the shape and morphology of inkjet-printed patterns.

  9. Droplet formation and lateral migration via solvent shifting in a microfluidic setup

    NASA Astrophysics Data System (ADS)

    Hajian, Ramin; Hardt, Steffen

    2014-11-01

    When a non-solvent is added to a solvent/solute mixture and if the solvent and the non-solvent are miscible, a part of the solute transforms to tiny (i.e. micron-/submicron-sized) droplets when the solvent concentration reduces. This phenomenon, resulting from supersaturation, is termed solvent shifting or Ouzo effect. Here we investigate this process in a co-flow microfluidic device. Thanks to the laminar nature of the flow, the mass transfer is mainly diffusive and can be analyzed employing (semi)analytical models. Using the resulting concentration profiles along with the ternary phase diagram (TPD) we analyze droplet formation and their lateral migration in the channel. The ternary system consists of a binary mixture (0.5wt% divinyle benzene (DVB) + 95.5wt% ethanol) and deionized water (non-solvent). Plotting concentration trajectories in the TPD we show that they hit the binodal curve in a region in which droplets of DVB form via nucleation, as opposed to spinodal decomposition. The lateral migration of droplets is partially attributed to the Marangoni effect induced by concentration gradients. However, the main effect governing droplet migration appears to be the phase-separation front (separating the one-phase and two-phase regions) moving toward the center of the channel.

  10. Effect of solvent on morphological properties of TiOx thin film

    NASA Astrophysics Data System (ADS)

    Liu, Meng-Yueh; Chang, Chih-Hua; Chang, Chin-Hsiang; Huang, Jing-Shun; Chao, Chia-Shin; Lin, Yu-Hong; Lin, Wen-Han; Lin, Ching-Fuh

    2009-08-01

    Sol-gel preparation of amorphous titanium oxide (TiOx) thin films with distinct morphological properties on the hydrophobic substrate was obtained by solution spin coating method. The TiOx thin films were deposited by three precursors using 2-methoxyethanol (2MOE), isopropanol (IPA) and mixture of 2MOE and hexane as solvents. We demonstrate evidence that the morphology of TiOx thin film is strongly related to the employment of dissimilar solvent. Among these three solvents, TiOx film obtained from 2MOE/hexane mixed solvent is a superior choice for the preparation of TiOx thin film on the hydrophobic substrate because of its smooth surface morphology.

  11. Microbial process for the preparation of acetic acid as well as solvent for its extraction from the fermentation broth

    DOEpatents

    Gaddy, James L.; Clausen, Edgar C.; Ko, Ching-Whan; Wade, Leslie E.; Wikstrom, Carl V.

    2002-01-01

    A modified water-immiscible solvent useful in the extraction of acetic acid from aqueous streams is a substantially pure mixture of isomers of highly branched di-alkyl amines. This solvent is substantially devoid of mono-alkyl amines and alcohols. Solvent mixtures formed of such a modified solvent with a desired cosolvent, preferably a low boiling hydrocarbon which forms an azeotrope with water are useful in the extraction of acetic acid from aqueous gaseous streams. An anaerobic microbial fermentation process for the production of acetic acid employs such solvents, under conditions which limit amide formation by the solvent and thus increase the efficiency of acetic acid recovery. Methods for the direct extraction of acetic acid and the extractive fermentation of acetic acid also employ the modified solvents and increase efficiency of acetic acid production. Such increases in efficiency are also obtained where the energy source for the microbial fermentation contains carbon dioxide and the method includes a carbon dioxide stripping step prior to extraction of acetic acid in solvent.

  12. Microbial process for the preparation of acetic acid as well as solvent for its extraction from the fermentation broth

    DOEpatents

    Gaddy, James L.; Clausen, Edgar C.; Ko, Ching-Whan; Wade, Leslie E.; Wikstrom, Carl V.

    2006-07-11

    A modified water-immiscible solvent useful in the extraction of acetic acid from aqueous streams is a substantially pure mixture of isomers of highly branched di-alkyl amines. This solvent is substantially devoid of mono-alkyl amines and alcohols. Solvent mixtures formed of such a modified solvent with a desired cosolvent, preferably a low boiling hydrocarbon which forms an azeotrope with water are useful in the extraction of acetic acid from aqueous gaseous streams. An anaerobic microbial fermentation process for the production of acetic acid employs such solvents, under conditions which limit amide formation by the solvent and thus increase the efficiency of acetic acid recovery. Methods for the direct extraction of acetic acid and the extractive fermentation of acetic acid also employ the modified solvents and increase efficiency of acetic acid production. Such increases in efficiency are also obtained where the energy source for the microbial fermentation contains carbon dioxide and the method includes a carbon dioxide stripping step prior to extraction of acetic acid in solvent.

  13. Hot-solvent miscible displacement

    SciTech Connect

    Awang, M.; Farouq Ali, S.M.

    1980-01-01

    This work describes an experimental and theoretical investigation of miscible displacement under nonisothermal conditions. The hot miscible floods were performed in an adiabatic glass bead pack, displacing one hydrocarbon by a more viscous hydrocarbon, the latter being at an elevated temperature. As a result, dispersion of both mass and heat took place, and was determined by temperature and concentration measurements. The system was simulated by coupled convective-diffusion and thermal conduction-convection equations. The results of the numerical as well as an approximate analytical solution were compared with the experimentally observed behavior. The numerical and experimental results point to the factors which should be considered in the choice of a solvent for a thermal-miscible type oil recovery process.

  14. Single polymer chains in poor solvent: Using the bond fluctuation method with explicit solvent

    NASA Astrophysics Data System (ADS)

    Jentzsch, Christoph; Werner, Marco; Sommer, Jens-Uwe

    2013-03-01

    We use the bond fluctuation model with explicit solvent to study single polymer chains under poor solvent conditions. Static and dynamic properties of the bond fluctuation model with explicit solvent are compared with the implicit solvent model, and the Θ-temperatures are determined for both solvent models. We show that even in the very poor solvent regime, dynamics is not frozen for the explicit solvent model. We investigate some aspects of the structure of a single collapsed globule and show that rather large chain lengths are necessary to reach the scaling regime of a dense sphere. The force-extension curve of a single polymer chain under poor solvent conditions in the fixed end-to-end distance ensemble is analyzed. We find that the transition of the tadpole conformation to the stretched chain conformation is rather smooth because of fluctuation effects, which is in agreement with recent experimental results.

  15. Quantitation of buried contamination by use of solvents. [degradation of silicone polymers by amine solvents

    NASA Technical Reports Server (NTRS)

    Pappas, S. P.; Hsiao, Y. C.; Hill, L. W.

    1973-01-01

    Spore recovery form cured silicone potting compounds using amine solvents to degrade the cured polymers was investigated. A complete list of solvents and a description of the effect of each on two different silicone polymers is provided.

  16. Wide electrochemical window solvents for use in electrochemical devices and electrolyte solutions incorporating such solvents

    DOEpatents

    Angell, Charles Austen; Zhang, Sheng-Shui; Xu, Kang

    1998-01-01

    The present invention relates to electrolyte solvents for use in liquid or rubbery electrolyte solutions. Specifically, this invention is directed to boron-containing electrolyte solvents and boron-containing electrolyte solutions.

  17. Single polymer chains in poor solvent: using the bond fluctuation method with explicit solvent.

    PubMed

    Jentzsch, Christoph; Werner, Marco; Sommer, Jens-Uwe

    2013-03-01

    We use the bond fluctuation model with explicit solvent to study single polymer chains under poor solvent conditions. Static and dynamic properties of the bond fluctuation model with explicit solvent are compared with the implicit solvent model, and the Θ-temperatures are determined for both solvent models. We show that even in the very poor solvent regime, dynamics is not frozen for the explicit solvent model. We investigate some aspects of the structure of a single collapsed globule and show that rather large chain lengths are necessary to reach the scaling regime of a dense sphere. The force-extension curve of a single polymer chain under poor solvent conditions in the fixed end-to-end distance ensemble is analyzed. We find that the transition of the tadpole conformation to the stretched chain conformation is rather smooth because of fluctuation effects, which is in agreement with recent experimental results. PMID:23485321

  18. Phenolic content and antioxidant activity of Hibiscus cannabinus L. seed extracts after sequential solvent extraction.

    PubMed

    Yusri, Noordin Mohd; Chan, Kim Wei; Iqbal, Shahid; Ismail, Maznah

    2012-01-01

    A sequential solvent extraction scheme was employed for the extraction of antioxidant compounds from kenaf (Hibiscus cannabinus L.) seeds. Yield of extracts varied widely among the solvents and was the highest for hexane extract (16.6% based on dry weight basis), while water extract exhibited the highest total phenolic content (18.78 mg GAE/g extract), total flavonoid content (2.49 mg RE/g extract), and antioxidant activities (p < 0.05). DPPH and hydroxyl radical scavenging, β-carotene bleaching, metal chelating activity, ferric thiocyanate and thiobarbituric acid reactive substances assays were employed to comprehensively assess the antioxidant potential of different solvent extracts prepared sequentially. Besides water, methanolic extract also exhibited high retardation towards the formation of hydroperoxides and thiobarbituric acid reactive substances in the total antioxidant activity tests (p < 0.05). As conclusion, water and methanol extracts of kenaf seed may potentially serve as new sources of antioxidants for food and nutraceutical applications. PMID:23099617

  19. 1983 Employment Outlook.

    ERIC Educational Resources Information Center

    Sanders, Howard J., Ed.

    1982-01-01

    Presents findings on employment situations for chemists and chemical engineers, focusing on: (1) comparison of chemists and chemical engineers; (2) salaries; (3) career planning; and (4) demand, indicated to be decidedly less than in previous years as a result of the deep business recession. (JN)

  20. Employment of College Students.

    ERIC Educational Resources Information Center

    High, Robert V.

    A survey was conducted to determine the effect on academic performance, if any, of employment on undergraduate college students. A questionnaire was sent to professors at 3 four-year colleges on Long Island (New York); various day classes were randomly selected. The final sample of n=257 represented approximately a 30 percent response. The…

  1. The Employability Skills Portfolio.

    ERIC Educational Resources Information Center

    Stemmer, Paul; And Others

    1992-01-01

    During 1990-91, Michigan schools piloted an innovative portfolio approach enabling students to discover, document, and develop employability skills in academics, personal management, and teamwork. Not an improved sorting system, the project encourages students to recognize successes, seek opportunities to improve skills, and gain confidence in…

  2. Should Universities Promote Employability?

    ERIC Educational Resources Information Center

    McCowan, Tristan

    2015-01-01

    Employability is becoming increasingly central to the mission and functioning of universities, spurred on by national and supranational agencies, and the demands of marketisation. This article provides a response to the normative dimensions of the question, progressing through four stages: first, there is a brief consideration of the meaning and…

  3. Learning Disabilities and Employment.

    ERIC Educational Resources Information Center

    Gerber, Paul J., Ed.; Brown, Dale S., Ed.

    This book provides information on preparing individuals with learning disabilities for the challenges of employment and outlines the rights of those with learning disabilities in the workplace. Introductory chapters in Part 1 include: "Life after School: Challenges in the Workplace" (Paul J. Gerber); "The New Economy in the 21st Century:…

  4. Disability Employment 101

    ERIC Educational Resources Information Center

    US Department of Education, 2007

    2007-01-01

    Business is about productivity and maintaining a competitive advantage. To do this, business needs qualified workers. Hiring people with disabilities adds value to a business and will attract new customers. Disability is not inability. Employers can make sound business decisions and gain a competitive advantage by using this guide to increase the…

  5. Westchester County Employers Survey.

    ERIC Educational Resources Information Center

    Lee, Marcia M.

    The Westchester County Employers Survey was done in May 2003 in order learn more about employee training needs, how they accomplished these needs, and how it would be possible for the Westchester Community College to fulfill these needs. Out of the 639 surveys sent, 145 were returned in a satisfactory format, which produces a 22.6% return rate.…

  6. Employability Skills Center.

    ERIC Educational Resources Information Center

    Sweetwater Union High School District, Chula Vista, CA.

    The Employability Skills Center (ESC) of the Division of Adult and Continuing Education (DACE) of the Sweetwater Union High School District (California) was created out of a need to help adult students develop the basic skills that are required for success in their chosen vocational programs but not taught in regular adult basic education classes.…

  7. Competing with Your Employer.

    ERIC Educational Resources Information Center

    Moller, Leslie

    1993-01-01

    Eleventh in a series featuring the 22 principles of the Association for Educational Communications and Technology Code of Ethics, this article presents a scenario: A training consultant decides to start his own company and convince 5 of his employers's clients to contract with him. Suggests that the complex ethical issues involved warrant seeking…

  8. Technology and employment

    SciTech Connect

    Cooper, M.H.

    1983-07-22

    The influence of technology on today's high unemployment picture is discussed. Employment in the high-technology sector is seen by some to be a panacea for workers who have lost their jobs due to irreversible structural causes. Some federal, regional, state, and local efforts being made to ease structural adjustment are included. 28 references, 2 figures, 3 tables.

  9. Survey of Employers.

    ERIC Educational Resources Information Center

    European Social Fund, Dublin (Ireland).

    A study examined attitudes of Irish employers toward vocational training (VT) activities, state agencies responsible for administering VT, and the skills that employees would need in the future. Of a sample of 500 firms that were selected as being representative from the standpoints of size, sector, location, and form of ownership, 219 were…

  10. Employer Engagement in Education

    ERIC Educational Resources Information Center

    Mann, Anthony; Dawkins, James

    2014-01-01

    The subject of this paper is employer engagement in education as it supports the learning and progression of young people through activities including work experience, job shadowing, workplace visits, career talks, mock interviews, CV workshops, business mentoring, enterprise competitions and the provision of learning resources. Interest has grown…

  11. Vietnamese Students Employability Skills

    ERIC Educational Resources Information Center

    Tuan, Nguyen Minh

    2011-01-01

    This paper attempts to investigate if the International University (IU) students' core competencies can meet the requirements set by employers, what are the differences in core competencies in final year students (or undergraduates), and how they view themselves compared with ex-students after one or two years in working environment, how…

  12. The Employment Mismatch

    ERIC Educational Resources Information Center

    Fischer, Karin

    2013-01-01

    Employers value a four-year college degree, many of them more than ever. Yet half of those surveyed recently by "The Chronicle" and American Public Media's "Marketplace" said they had trouble finding recent graduates qualified to fill positions at their company or organization. Nearly a third gave colleges just fair to poor marks for producing…

  13. Engaging Employers in Assessment

    ERIC Educational Resources Information Center

    Brown, Gary; DesRosier, Theron; Peterson, Nils; Chida, Meriem; Lagier, Randy

    2009-01-01

    In this article, the authors describe a pilot project in which formative feedback from industry professionals creates a genuine learning experience for students. Industry is giving feedback to higher education that many graduates are not employable or that they need substantial postcollegiate on-the-job training. Higher education is struggling to…

  14. Equal Opportunity in Employment

    ERIC Educational Resources Information Center

    Bullock, Paul

    This book focuses on discrimination in employment, defined as the denial of equal opportunity in the labor market to qualified persons on the basis of race, color, religion, national origin, age, sex, or any other factor not related to their individual qualifications for work. The average nonwhite college graduate can expect to earn less during…

  15. A Stochastic Employment Problem

    ERIC Educational Resources Information Center

    Wu, Teng

    2013-01-01

    The Stochastic Employment Problem(SEP) is a variation of the Stochastic Assignment Problem which analyzes the scenario that one assigns balls into boxes. Balls arrive sequentially with each one having a binary vector X = (X[subscript 1], X[subscript 2],...,X[subscript n]) attached, with the interpretation being that if X[subscript i] = 1 the ball…

  16. Employers, Families and Education.

    ERIC Educational Resources Information Center

    Partnership for Family Involvement in Education (ED), Washington, DC.

    Family involvement in education is good for business, critical to children's school achievement, and important in creating strong and vibrant communities. This report discusses the role of businesses and employers in helping partners and family members be more involved in children's learning. Throughout the report, programs at specific companies…

  17. Dispersing nanoparticles in a polymer film via solvent evaporation

    DOE PAGESBeta

    Cheng, Shengfeng; Grest, Gary S.

    2016-05-19

    Large-scale molecular dynamics simulations are used to study the dispersion of nanoparticles (NPs) in a polymer film during solvent evaporation. As the solvent evaporates, a dense polymer-rich skin layer forms at the liquid/vapor interface, which is either NP rich or poor depending on the strength of the NP/polymer interaction. When the NPs are strongly wet by the polymer, the NPs accumulate at the interface and form layers. However, when the NPs are only partially wet by the polymer, most NPs are uniformly distributed in the bulk of the polymer film, with the dense skin layer serving as a barrier tomore » prevent the NPs from moving to the interface. Furthermore, our results point to a possible route to employ less favorable NP/polymer interactions and fast solvent evaporation to uniformly disperse NPs in a polymer film, contrary to the common belief that strong NP/polymer attractions are needed to make NPs well dispersed in polymer nanocomposites.« less

  18. Ion solvation in aqueous and non-aqueous solvents

    NASA Astrophysics Data System (ADS)

    Arslanargin, Ayse

    The thermodynamics of ion solvation is studied in both water and some organic solvents using computational and theoretical techniques. Free energy partitioning analysis is employed to explore the driving forces for ions interacting with the water liquid/vapor interface using optimized point charge models for the Na+ and I- ions and the extended simple point charge water model. The absolute hydration free energy is partitioned into cavity formation, attractive van der Waals, local electrostatic, and far-field electrostatic contributions. The bulk hydration free energy of the ions is computed first, followed by the free energy to insert the ions at the center of a water slab. Shifts of the ion free energies occur in the slab geometry are consistent with the extended simple point charge water model surface potential of the water liquid/vapor interface. Then the free energy profiles are examined for ion passage from the slab center to the dividing surface. The profiles show that, for the large chaotropic I- ion, the relatively flat total free energy profile results from the near cancellation of several large contributions. On the other hand, the small Na+ ion is repelled from the liquid/vapor interface mainly by the far field electrostatic term. The far-field electrostatic part of the free energy, largely due to the water liquid/vapor interface potential, has an important effect on ion distributions near the surface in the classical model. However, that the individual forms of the local and far-field electrostatic contributions are expected to be model dependent when comparing classical and quantum results. Non-aqueous solvents such as ethylene carbonate, and propylene carbonate are widely used as liquid electrolytes in electrochemical energy storage systems. The electrolyte structure affects the efficiency of the ion transport, and understanding the solvent structure is essential for battery performance enhancements. Free energy and enthalpy of solvation calculations

  19. Complete Genome Sequence of the Solvent Producer Clostridium saccharobutylicum NCP262 (DSM 13864)

    PubMed Central

    Poehlein, Anja; Hartwich, Katrin; Krabben, Preben; Ehrenreich, Armin; Liebl, Wolfgang; Dürre, Peter; Gottschalk, Gerhard

    2013-01-01

    Clostridium saccharobutylicum was employed for the production of acetone and butanol in South Africa until the 1970s. The genome comprises a single replicon (5,107,814 bp) harboring all the genes necessary for solvent production and the degradation of various organic compounds, such as fructose, cellobiose, sucrose, and mannose. PMID:24285650

  20. Complete Genome Sequence of the Solvent Producer Clostridium saccharobutylicum NCP262 (DSM 13864).

    PubMed

    Poehlein, Anja; Hartwich, Katrin; Krabben, Preben; Ehrenreich, Armin; Liebl, Wolfgang; Dürre, Peter; Gottschalk, Gerhard; Daniel, Rolf

    2013-01-01

    Clostridium saccharobutylicum was employed for the production of acetone and butanol in South Africa until the 1970s. The genome comprises a single replicon (5,107,814 bp) harboring all the genes necessary for solvent production and the degradation of various organic compounds, such as fructose, cellobiose, sucrose, and mannose. PMID:24285650

  1. TERRA-KLEEN RESPONSE GROUP, INC. SOLVENT EXTRACTION TECHNOLOGY: INNOVATIVE TECHNOLOGY EVALUATION REPORT

    EPA Science Inventory

    This report summarizes the results of a field demonstration conducted under the SITE program. The technology which was demonstrated was a solvent extraction technology developed by Terra-Kleen Response Group. Inc. to remove organic contaminants from soil. The technology employs...

  2. SOLVENT RECOVERY AT VANDENBERG AIR FORCE BASE

    EPA Science Inventory

    The report gives results of a feasibility study of the addition of vapor recovery and solvent purification equipment for Vandenberg Air Force Base (VAFB) to reuse the large quantities of waste solvent generated in space shuttle preparation operations. (NOTE: Operation of VAFB as ...

  3. Green chemicals: Searching for cleaner solvents

    SciTech Connect

    Lucas, A.

    1994-10-05

    While increased pressure from EPA has solvents producers scrambling to find greener alternatives, many say the cost effectiveness and performance characteristics of traditional technologies are such that they will not disappear quickly. Though a variety of alternative {open_quotes}green{close_quotes} solvents have been developed and commercialized, better means of solvent recovery have also come along, ensuring continued use of many organic solvents. The 1990 Clean Air Act (CAA), designed to eliminate volatile organic compounds (VOCs), ozone depleters, and other hazardous air pollutants (HAPs), has put limits on many organic solvents. Those most under fire are chlorinated solvents, such as methylene chloride, 1,1,1 trichloroethylene (methyl chloroform), and chlorofluorocarbon (CFC)-113. Producers have been developing a variety of lower VOC solvents to replace those being phased out or regulated. Among those likely to experience most growth are aliphatic hydrocarbons to replace chlorinated solvents in cleaning applications. Growth is also expected for alcohols, esters, and glycol ethers for other end-use applications.

  4. Remediating pesticide contaminated soils using solvent extraction

    SciTech Connect

    Sahle-Demessie, E.; Meckes, M.C.; Richardson, T.L.

    1996-12-31

    Bench-scale solvent extraction studies were performed on soil samples obtained from a Superfund site contaminated with high levels of p,p{prime}-DDT, p,p{prime}-DDE and toxaphene. The effectiveness of the solvent extraction process was assessed using methanol and 2-propanol as solvents over a wide range of operating conditions. It was demonstrated that a six-stage methanol extraction using a solvent-to-soil ratio of 1.6 can decrease pesticide levels in the soil by more than 99% and reduce the volume of material requiring further treatment by 25 times or more. The high solubility of the pesticides in methanol resulted in rapid extraction rates, with the system reaching quasi-equilibrium state in 30 minutes. The extraction efficiency was influenced by the number of extraction stages, the solvent-to-soil ratio, and the soil moisture content. Various methods were investigated to regenerate and recycle the solvent. Evaporation and solvent stripping are low cost and reliable methods for removing high pesticide concentrations from the solvent. For low concentrations, GAC adsorption may be used. Precipitating and filtering pesticides by adding water to the methanol/pesticide solution was not successful when tested with soil extracts. 26 refs., 10 figs., 6 tabs.

  5. 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...

  6. Solvation of rhodamine575 in some solvents

    NASA Astrophysics Data System (ADS)

    Sharma, Amit

    2016-05-01

    FTIR spectra of Rhodamine575 dye in powder form and in different solvents are reported. Positions of some of the observed FTIR bands show noticeable change in solvents. The bands, which shift, have contributions from the vibrational motion of nitrogen atoms of the ethylamine groups, oxygen atom of the carboxylic group attached to the phenyl ring and oxygen atom of the Xanthene ring.

  7. Improved Supercritical-Solvent Extraction of Coal

    NASA Technical Reports Server (NTRS)

    Compton, L.

    1982-01-01

    Raw coal upgraded by supercritical-solvent extraction system that uses two materials instead of one. System achieved extraction yields of 20 to 49 weight percent. Single-solvent yields are about 25 weight percent. Experimental results show extraction yields may be timedependent. Observed decreases in weight of coal agreed well with increases in ash content of residue.

  8. Supercritical-Multiple-Solvent Extraction From Coal

    NASA Technical Reports Server (NTRS)

    Corcoran, W.; Fong, W.; Pichaichanarong, P.; Chan, P.; Lawson, D.

    1983-01-01

    Large and small molecules dissolve different constituents. Experimental apparatus used to test supercritical extraction of hydrogen rich compounds from coal in various organic solvents. In decreasing order of importance, relevant process parameters were found to be temperature, solvent type, pressure, and residence time.

  9. Coal mining with a liquid solvent

    NASA Technical Reports Server (NTRS)

    Lawson, D. D.; Miller, C. G.

    1979-01-01

    Study suggests carbonated water can dissolve or suspend coal and carry it to surface. Mixture of carbon dioxide and water may be coal solvent that will make unmanned mining reality. When used with proposed process monitoring coal solubility with conventional strain gage, solvent is basis for rapid cost effective extraction of coal from underground seams.

  10. REMEDIATION OF CONTAMINATED SOILS BY SOLVENT FLUSHING

    EPA Science Inventory

    Solvent flushing is a potential technique for remediating a waste disposal/spill site contaminated with organic chemicals. This technique involves the injection of a solvent mixture (e.g., water plus alcohols) that enhances contaminant solubility, reduces the retardation factor, ...

  11. Classification of Solvents according to Interaction Mechanisms.

    ERIC Educational Resources Information Center

    Ahmed, Wasi

    1979-01-01

    Presented is a model for solvent effects based on the observation that the excitation energy of all-trans-N-Retinylidenmethyl-n-butylammonium iodide is directly related to the dielectric constant of a series of aromatic and aliphatic solvents as the dielectric constant (e) ranges from 2 to 10.5. (BT)

  12. REMEDIATING PESTICIDE CONTAMINATED SOILS USING SOLVENT EXTRACTION

    EPA Science Inventory

    Bench-scale solvent extraction studies were performed on soil samples obtained from a Superfund site contaminated with high levels of p,p'-DDT, p,p'-DDD,, p,p'-DDE and toxaphene. The effectiveness of the solvent extraction process was assessed using methanol and 2-propanol as sol...

  13. Pneumatic conveying of pulverized solvent refined coal

    DOEpatents

    Lennon, Dennis R.

    1984-11-06

    A method for pneumatically conveying solvent refined coal to a burner under conditions of dilute phase pneumatic flow so as to prevent saltation of the solvent refined coal in the transport line by maintaining the transport fluid velocity above approximately 95 ft/sec.

  14. A spreadsheet algorithm for stagewise solvent extraction

    SciTech Connect

    Leonard, R.A.; Regalbuto, M.C.

    1993-01-01

    Part of the novelty is the way in which the problem is organized in the spreadsheet. In addition, to facilitate spreadsheet setup, a new calculational procedure has been developed. The resulting Spreadsheet Algorithm for Stagewise Solvent Extraction (SASSE) can be used with either IBM or Macintosh personal computers as a simple yet powerful tool for analyzing solvent extraction flowsheets.

  15. SOLVENT DESIGN UNDER VARYING ENVIRONMENTAL REQUIREMENTS

    EPA Science Inventory

    There is currently a great need to replace many solvents that are commonly used by industry and the public, but whose continued use entails a number of human health and environmental risks. One issue hampering solvent replacement is the general thought that replacement, particul...

  16. ENHANCED PROCESSING OF GREEN SOLVENTS - PHASE I

    EPA Science Inventory

    Solvents are a valuable processing tool in the chemical and related industries. Solvents are used to enhance mass transfer, heat transfer and in most cases are a processing aid and eventually are not used in the final product but to enhance the fabrication of the final pr...

  17. Structure of the polymer-solvent interface

    NASA Technical Reports Server (NTRS)

    Miles, Danny G., Jr.; Schmidt, James W.

    1990-01-01

    The first measurements of ellipticities from the liquid-liquid interface between polymer and solvent mixtures near their consolute points are reported. When scaled according to theory the ellipticities of high molecular weight polystyrene + solvent mixtures are consistent with those from simple, low molecular weight mixtures. The universal value of the scaled ellipticity is approximately 20 percent lower than that predicted by present theories.

  18. EXPERIENCES IN DESIGNING SOLVENTS FOR THE ENVIRONMENT

    EPA Science Inventory

    Solvents used throughout industry are chosen to meet specific technological requirements such as solute solubility, cleaning and degreasing, or being a medium for paints and coatings. With the increasing awareness of the human health effects and environmental tisks of solvent use...

  19. EXPERIENCES IN DESIGNING SOLVENTS FOR THE ENVIRONMENT

    EPA Science Inventory

    Solvents used throughout industry are chosen to meet specific technological requirements such as solute solubility, cleaning and degreasing, or being a medium for paints and coatings. With the increasing awareness of the human health effects and environmental risks of solvent use...

  20. 29 CFR 1607.10 - Employment agencies and employment services.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... other user of its responsibilities under Federal law to provide equal employment opportunity or its..., including private employment agencies and State employment agencies, which agrees to a request by...

  1. 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.

  2. Stabilization of Underground Solvent Storage Tanks

    SciTech Connect

    Smail, T.R.

    2003-08-15

    The Old Solvent Tanks (OST), located at the Savannah River Site (SRS) are comprised of 22 underground storage tanks that were used to store spent radioactive solvent and aqueous wastes generated from the plutonium-uranium extraction (PUREX) process. The OSTs were installed at various dates between 1955 and 1968 and used to store the spent solvents until 1974. The spent solvents stored in the OSTs were transferred out from 1976 through 1981 leaving only residual liquids and sludges that could not be pumped out.Final remediation goals include an overlying infiltration control system. If the tanks were to structurally fail, they would collapse causing potential for onsite worker exposure and release of tank contents to the environment. Therefore, as an interim action, methods for stabilizing the tanks were evaluated. This paper will discuss the systems designed to perform and monitor the grouting operation, the grouting process, and the radiological controls and wastes associated with grouting the Old Solvent Tanks.

  3. SOLVENT DISPERSION AND FLOW METER CALCULATION RESULTS

    SciTech Connect

    Nash, C.; Fondeur, F.; Peters, T.

    2013-06-21

    Savannah River National Laboratory (SRNL) found that the dispersion numbers for the six combinations of CSSX:Next Generation Solvent (NGS) “blend” and pure NGS versus salt solution, caustic wash, and strip aqueous solutions are all good. The dispersion numbers are indications of processability with centrifugal contactors. A comparison of solvent physical and thermal properties shows that the Intek™ solvent flow meter in the plant has a reading biased high versus calibrated flow when NGS is used, versus the standard CSSX solvent. The flow meter, calibrated for CSSX solvent, is predicted to read 2.8 gpm of NGS in a case where the true flow of NGS is 2.16 gpm.

  4. Toxic hepatitis in occupational exposure to solvents

    PubMed Central

    Malaguarnera, Giulia; Cataudella, Emanuela; Giordano, Maria; Nunnari, Giuseppe; Chisari, Giuseppe; Malaguarnera, Mariano

    2012-01-01

    The liver is the main organ responsible for the metabolism of drugs and toxic chemicals, and so is the primary target organ for many organic solvents. Work activities with hepatotoxins exposures are numerous and, moreover, organic solvents are used in various industrial processes. Organic solvents used in different industrial processes may be associated with hepatotoxicity. Several factors contribute to liver toxicity; among these are: species differences, nutritional condition, genetic factors, interaction with medications in use, alcohol abuse and interaction, and age. This review addresses the mechanisms of hepatotoxicity. The main pathogenic mechanisms responsible for functional and organic damage caused by solvents are: inflammation, dysfunction of cytochrome P450, mitochondrial dysfunction and oxidative stress. The health impact of exposure to solvents in the workplace remains an interesting and worrying question for professional health work. PMID:22719183

  5. Hydrocarbon-solvent based cleaners as replacements for chlorinated and CFC solvents

    SciTech Connect

    Schreiner, J.L.; Berlin, E.P.

    1995-12-31

    Chlorinated and CFC solvents have been used for about 30 years to remove various contaminants from products during the manufacturing process. Among the contaminants being removed are oils, greases, and waxes that have petroleum products as the base. Prior to the advent of the chlorinated solvents petroleum distillates were used for these cleaning operations. Processing improvements over the past 30 years now permit production of higher purity hydrocarbons solvents that can be used as replacements for the chlorinated and CFC solvents being phased out. These hydrocarbon solvents are well suited for removal of the various petroleum based contaminants, as one recalls the old adage {open_quotes}like dissolves like.{close_quotes}

  6. PARIS II: Computer Aided Solvent Design for Pollution Prevention

    EPA Science Inventory

    This product is a summary of U.S. EPA researchers' work developing the solvent substitution software tool PARIS II (Program for Assisting the Replacement of Industrial Solvents, version 2.0). PARIS II finds less toxic solvents or solvent mixtures to replace more toxic solvents co...

  7. Waterflooding employing amphoteric surfactants

    SciTech Connect

    Stournas, S.

    1980-08-05

    Process for the recovery of oil from a subterranean oil reservoir involving the injection into the reservoir of an aqueous solution of an amphoteric surfactant having an inner quaternary ammonium group linked to a terminal sulfonate or carboxylate group is described. The amphoteric surfactants may be employed in relatively low concentrations within the range of 0.0005 to 0.1% by weight and injected in a slug of at least 0.5 pv. The apparatus may be applied in situations in which the reservoir waters and/or the waters employed in formulating the surfactant solution contain relatively high amounts of divalent metal ions. Specifically described amphoteric surfactants include hydrocarby dialkyl or dihydroxyalkyl ammonium alkane sulfonates and carboxylates in which the hydrocarbyl group contains from 8 to 26 carbon atoms. 29 claims.

  8. Employer and consumer perspectives.

    PubMed

    McGhan, W F

    1998-11-01

    This paper reviews various published reports from surveys on employer opinion, perception of needs, and trends with regard to healthcare benefits; the consumer perspective regarding healthcare is also discussed. Surveys indicate that businesses want continuous evidence that high-quality healthcare can positively impact company profits. Employers and labor unions are demanding more cost-effective healthcare. At both employer and consumer levels, greater patient education is needed, as well as traditional educational media. Direct-to-consumer advertising and use of the World Wide Web are increasingly important in enabling consumers to participate more fully in their own lipid-related decision-making. Finally, the transition of lipid-lowering drugs to over-the-counter accessibility has great implications with respect to issues of patient preferences and willingness to pay in the evolving healthcare environment. Groups in the United States, such as the National Committee on Quality Assurance and the Foundation for Accountability, are setting standards and beginning to assess both process and outcomes in patient care. Further collaborative efforts are needed that raise standards of care and stimulate more cost-effective healthcare. The pharmacoeconomics and outcomes data gathered will, one hopes, also demonstrate to global businesses the positive financial impact of high-quality healthcare and appropriate lipid therapy. PMID:16674548

  9. Predicting the Solubility of Pharmaceutical Cocrystals in Solvent/Anti-Solvent Mixtures.

    PubMed

    Lange, Linda; Heisel, Stefan; Sadowski, Gabriele

    2016-01-01

    In this work, the solubilities of pharmaceutical cocrystals in solvent/anti-solvent systems were predicted using PC-SAFT in order to increase the efficiency of cocrystal formation processes. Modeling results and experimental data were compared for the cocrystal system nicotinamide/succinic acid (2:1) in the solvent/anti-solvent mixtures ethanol/water, ethanol/acetonitrile and ethanol/ethyl acetate at 298.15 K and in the ethanol/ethyl acetate mixture also at 310.15 K. The solubility of the investigated cocrystal slightly increased when adding small amounts of anti-solvent to the solvent, but drastically decreased for high anti-solvent amounts. Furthermore, the solubilities of nicotinamide, succinic acid and the cocrystal in the considered solvent/anti-solvent mixtures showed strong deviations from ideal-solution behavior. However, by accounting for the thermodynamic non-ideality of the components, PC-SAFT is able to predict the solubilities in all above-mentioned solvent/anti-solvent systems in good agreement with the experimental data. PMID:27164075

  10. Charge stabilization in nonpolar solvents.

    PubMed

    Hsu, M F; Dufresne, E R; Weitz, D A

    2005-05-24

    While the important role of electrostatic interactions in aqueous colloidal suspensions is widely known and reasonably well-understood, their relevance to nonpolar suspensions remains mysterious. We measure the interaction potentials of colloidal particles in a nonpolar solvent with reverse micelles. We find surprisingly strong electrostatic interactions characterized by surface potentials, |ezeta|, from 2.0 to 4.4 k(B)T and screening lengths, kappa(-1), from 0.2 to 1.4 microm. Interactions depend on the concentration of reverse micelles and the degree of confinement. Furthermore, when the particles are weakly confined, the values of |ezeta| and kappa extracted from interaction measurements are consistent with bulk measurements of conductivity and electrophoretic mobility. A simple thermodynamic model, relating the structure of the micelles to the equilibrium ionic strength, is in good agreement with both conductivity and interaction measurements. Since dissociated ions are solubilized by reverse micelles, the entropic incentive to charge a particle surface is qualitatively changed from aqueous systems, and surface entropy plays an important role. PMID:15896027

  11. Office of Disability Employment Policy

    MedlinePlus

    ... HIV/AIDS Housing Integrated Employment Mental Health National Disability Employment Awareness Month (NDEAM) Older Workers Personal Assistance Services Publications for Order Recruitment & Retention Research Self-Employment & Entrepreneurship Small Business State Policy Stay at Work/Return ...

  12. Solvent Effect on the Photolysis of Riboflavin.

    PubMed

    Ahmad, Iqbal; Anwar, Zubair; Ahmed, Sofia; Sheraz, Muhammad Ali; Bano, Raheela; Hafeez, Ambreen

    2015-10-01

    The kinetics of photolysis of riboflavin (RF) in water (pH 7.0) and in organic solvents (acetonitrile, methanol, ethanol, 1-propanol, 1-butanol, ethyl acetate) has been studied using a multicomponent spectrometric method for the assay of RF and its major photoproducts, formylmethylflavin and lumichrome. The apparent first-order rate constants (k obs) for the reaction range from 3.19 (ethyl acetate) to 4.61 × 10(-3) min(-1) (water). The values of k obs have been found to be a linear function of solvent dielectric constant implying the participation of a dipolar intermediate along the reaction pathway. The degradation of this intermediate is promoted by the polarity of the medium. This indicates a greater stabilization of the excited-triplet states of RF with an increase in solvent polarity to facilitate its reduction. The rate constants for the reaction show a linear relation with the solvent acceptor number indicating the degree of solute-solvent interaction in different solvents. It would depend on the electron-donating capacity of RF molecule in organic solvents. The values of k obs are inversely proportional to the viscosity of the medium as a result of diffusion-controlled processes. PMID:25698084

  13. Differential response of marine diatoms to solvents

    SciTech Connect

    Tadros, M.G.; Phillips, J.; Patel, H.; Pandiripally, V.

    1995-06-01

    Unicellular algae in aquatic ecosystems are subjected to a variety of pollutants from sources such as runoff from agricultural lands and industrial outfalls. Organic solvents are natural components of oil deposits and commonly find their way into surface waters as a result of discharges from refineries, waste oil, disposal, and accidental spills. Organic solvents can make their way into the environment as industrial wastes. Because of their carcinogenic potential, contamination of soil and water by solvents is cause for serious concern. Relatively few reports have been published on the comparative toxicity of solvents towards test organisms, and these dealt primarily with fish and aquatic invertebrates. However, only few data of toxicity effects of solvents on algae have been published. Phytoplankton species vary in their tolerance to trace metals. Diatoms in particular are able to detoxify trace metals by the excretion of organic compounds. A previous study reported that diatoms collected form different sites in the Gulf of Mexico varied in their physiological characteristics. Algae have been considered to be good indicator s of bioactivity of industrial wastes. Unicellular algae vary in their response to a variety of toxicants. Little is known, however, about toxicity of solvents to marine diatoms. The work reported here was done to examine the effect of selected solvents on seven diatom species to determine whether they differed in their responses to these chemicals. 16 refs., 1 fig.

  14. 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

  15. Effect of solvent characteristics on coal liquefaction

    SciTech Connect

    Huang, He; Wang, Shaojie; Wang, Keyu; Klein, M.T.; Calkins, W.H.

    1996-12-31

    It has been known for a long time that the characteristics of the liquefaction solvent has a profound effect on direct coal liquefaction. The amount of hydrogen consumed during the liquefaction process, the degree and quantity of retrograde reactions that occur, and the quality of the liquid products are all influenced by the process solvent. A number of analytical approaches have been developed to determine the important characteristics of the solvent for coal liquefaction. The hydrogen donor ability has clearly been important. However, such other characteristics of a liquefaction solvent as solubility parameter, content and type of higher aromatic hydrocarbons, and phenolic content have also been found to be significant. Finseth et al. have shown that the bulk of the hydrogen consumed from an uncatalyzed donor solvent liquefaction above 400{degrees}C is consumed in gas generation, heteroatom removal and hydrogenolysis of the coal matrix. Wilson et al. have also shown that the major role of hydrogen in uncatalyzed liquefaction is consumed by alkyl fission and hydrogenolysis reactions and not with hydrogenating aromatic rings. McMillan et al. have postulated that a radical hydrogen transfer process along with donor solvent capping of thermally produced radicals from the coal as possible processes involved with the hydroaromatic donor solvents in coal liquefaction. With the development of a short contact time batch reactor (SCTBR), determining the influence of the processing solvent on the liquefaction rates, conversion profiles and the quality of the liquid product at a particular time became possible. The influence of type of solvent, combined with other effects, such as gas atmosphere (i.e., in hydrogen and in nitrogen) and catalyst, on the coal liquefaction is reported in this paper.

  16. THE DESIGN OF TECHNOLOGICALLY EFFECTIVE AND ENVIRONMENTALLY BENIGN SOLVENT SUBSTITUTES

    EPA Science Inventory

    There is presently considerable interest in finding environmentally benign replacement solvents that can perform in many different applications as solvents normally do. This requires solvents with desirable properties, e.g., ability to dissolve certain compounds, and without oth...

  17. Graduate Employability: A Conceptual Framework for Understanding Employers' Perceptions

    ERIC Educational Resources Information Center

    Cai, Yuzhuo

    2013-01-01

    This study provides a conceptual framework for understanding what employers think about the value of graduates with similar educational credentials in the workplace (their employability), using insights from the new institutionalism. In this framework, the development of employers' beliefs about graduates' employability is broken into a number of…

  18. Energy requirements for wet solvent extraction of lipids from microalgal biomass.

    PubMed

    Martin, Gregory J O

    2016-04-01

    Biofuel production from microalgae requires energy efficient processes for extracting and converting triacylglyceride lipids to fuel, compatible with coproduction of protein feeds and nutraceuticals. Wet solvent extraction involves mechanical cell rupture, lipid extraction via solvent contacting, physical phase separation, thermal solvent recovery, and transesterification. A detailed analysis of the effect of key process parameters on the parasitic energy demand of this process was performed. On a well-to-pump basis, between 16% and 320% of the resultant biodiesel energy was consumed depending solely on the process parameters. Highly positive energy balances can be achieved, but only if a correctly designed process is used. This requires processing concentrated biomass (ca 25%w/w) with a high triacylglyceride content (ca 30%w/w), and an efficient extraction process employing a non-polar solvent, low solvent-to-paste ratio, and efficient energy recovery. These requirements preclude many laboratory scale processes and polar co-solvents as viable options for large-scale biofuel production. PMID:26802186

  19. Physical Solvents that are Alternatives for PEGDME in CO{sub 2} Absorption

    SciTech Connect

    Miller, M.B.; Luebke, D.R.; Enick, R.M.

    2011-03-01

    Advanced gasification power plants will employ the water-gas shift reaction producing a high pressure gas-phase mixture containing CO{sub 2}, H{sub 2} and water. This gas mixture at elevated pressures provides ample driving force in order to use a physical solvent that will selectively absorb, not chemically bind, to the CO{sub 2}. Potential physical absorbers include (a) liquid mixtures of CO{sub 2}-philic polydisperse oligomers, (b) small, volatile, liquid CO{sub 2}-philic solvents, and (c) CO{sub 2}-philic solids capable of melting in the presence of CO{sub 2}. The objective of this study was to identify alternative physical solvents that would selectively dissolve only CO{sub 2} from this mixture. The first phase of our research involved the comparison of the CO{sub 2} solvent strength of PEGDME with that of other low volatility oligomers that are known to be “CO{sub 2}-philic”. Small volatile CO{sub 2} solvents were also examined in the second phase of this work. Lastly, solid CO{sub 2}-philes have been investigated as a potential CO{sub 2} solvent.

  20. Permeation of chlorothalonil through nitrile gloves: collection solvent effects in the closed-loop permeation method.

    PubMed

    Que Hee, Shane S; Zainal, Hanaa

    2010-07-15

    The aim was to measure the permeation of the fungicide chlorothalonil from Bravo Ultrex through disposable (Safeskin) and chemically protective (Solvex) nitrile glove materials in a closed-loop ASTM type permeation cell system employing different collection side solvents. The permeated fungicide was measured in the collection medium by the internal standard method through capillary gas chromatography-mass spectrometry and selective ion monitoring using m/z 222 (internal standard 4,4'-dichlorobiphenyl), and 224 and 226 (chlorothalonil). The permeated glove materials did not show swelling or shrinkage and infrared reflectance changes. Different permeated masses for the same glove material for aqueous emulsion challenges of 2.2 mg/mL Bravo Ultrex for 8 h were observed for different solvents with isopropanol>hexane>water for Safeskin, and isopropanol=hexane>water for Solvex. Solvex gloves always permeated less than Safeskin gloves for the same challenge time. When challenges with solid Bravo Ultrex occurred, chlorothalonil was still found in the collection side in the same solvent order as for the aqueous emulsion challenges, with Solvex always less than Safeskin for the same collection solvent and same challenge time. Kinetic experiments showed isopropanol was not a suitable collection solvent for Safeskin for 4 and 8 h. Hexane was not a valid collection solvent for Solvex and Safeskin for 8 h, but was better than isopropanol. PMID:20334969

  1. Cleaning solvent substitution in electronic assemblies

    SciTech Connect

    Meier, G.J.

    1993-09-01

    Alternatives to chlorinated and fluorinated solvents have been identified, qualified, and implemented into production of complex electronic assemblies. Extensive compatibility studies were performed with components, piece-parts, and materials. Electrical testing and accelerated aging were used to screen for detrimental, long-term effects. A terpene, d-limonene, has been selected as the solvent of choice for cleaning complex electronic assemblies, and has been found to be compatible with the components and materials tested. A brief history of the overall project will be presented, along with representative cleaning efficiency results, compatibility results, and residual solvent data.

  2. Solvent environment conducive to protein aggregation.

    PubMed

    Fernández, Ariel; de las Mercedes Boland, Maria

    2002-10-01

    The effect of solvent structuring induced by molecular crowding is elucidated within a competitive situation involving protein folding and aggregation. Two patterned fragments of amyloidogenic proteins are chosen as study cases and analyzed by molecular dynamics with an implicit treatment of the solvent. The extent of crowding needed to induce aggregation is determined. The results constitute a first step to assess the relevance of in vivo environments in understanding fibrillogenesis. The approach is independently validated by satisfactorily reproducing the results of an all-atom explicit solvent trajectory. PMID:12372617

  3. Switchable solvents and methods of use thereof

    SciTech Connect

    Jessop, Philip G; Eckert, Charles A; Liotta, Charles L; Heldebrant, David J

    2014-04-29

    A solvent that reversibly converts from a nonionic liquid mixture to an ionic liquid upon contact with a selected trigger, e.g., contact with CO.sub.2, is described. In preferred embodiments, the ionic solvent is readily converted back to the nonionic liquid mixture. The nonionic liquid mixture includes an amidine or guanidine or both, and water, alcohol, or a combination thereof. Single component amine solvents that reversibly convert between ionic and non-ionic states are also described. Some embodiments require increased pressure to convert; others convert at 1 atmosphere.

  4. Genomic and Genetic Approaches to Solvent Tolerance

    SciTech Connect

    Eleftherios T. Papoutsakis

    2005-06-10

    The proposed research is to understand and exploit the molecular basis that determines tolerance of the industrially important anaerobic clostridia to solvents. Furthermore, we aim to develop general genomic and metabolic engineering strategies for understanding the molecular basis of tolerance to chemicals and for developing tolerant strains. Our hypothesis is that the molecular basis of what makes bacterial cells able to withstand high solvent concentrations can be used to metabolically engineer cells so that they can tolerate higher concentrations of solvents and related chemicals.

  5. Switchable solvents and methods of use thereof

    DOEpatents

    Jessop, Philip G.; Eckert, Charles A.; Liotta, Charles L.; Heldebrant, David J.

    2013-08-20

    A solvent that reversibly converts from a nonionic liquid mixture to an ionic liquid upon contact with a selected trigger, e.g., contact with CO.sub.2, is described. In preferred embodiments, the ionic solvent is readily converted back to the nonionic liquid mixture. The nonionic liquid mixture includes an amidine or guanidine or both, and water, alcohol, or a combination thereof. Single component amine solvents that reversibly convert between ionic and non-ionic states are also described. Some embodiments require increased pressure to convert; others convert at 1 atmosphere.

  6. Switchable solvents and methods of use thereof

    DOEpatents

    Jessop, Philip G.; Eckert, Charles A.; Liotta, Charles L.; Heldebrant, David J.

    2011-07-19

    A solvent that reversibly converts from a nonionic liquid mixture to an ionic liquid upon contact with a selected trigger, e.g., contact with CO.sub.2, is described. In preferred embodiments, the ionic solvent is readily converted back to the nonionic liquid mixture. The nonionic liquid mixture includes an amidine or guanidine or both, and water, alcohol, or a combination thereof. Single component amine solvents that reversibly convert between ionic and non-ionic states are also described. Some embodiments require increased pressure to convert; others convert at 1 atmosphere.

  7. What makes critical-solvent processes work

    SciTech Connect

    Brule, M.R.; Corbett, R.W.

    1984-06-01

    Critical-solvent processing (sometimes called supercritical-gas extraction) is an ongoing technology based on phase-equilibrium phenomena in the critical region. Many new practical applications of critical-solvent processing are being conceived and implemented in the food, drug and chemical industries. The advantages afforded by critical-solvent processing in performing difficult separations such as caffeine from coffee, nicotine from tobacco, chemotherapeutic drugs from plants, and chemical feedstocks from petroleum and synfuels residua have been realized just in the last decade or so.

  8. A Spreadsheet Algorithm for Stagewise Solvent Extraction

    SciTech Connect

    Leonard, R.A.; Regalbuto, M.C.

    1993-08-01

    The material balance and equilibrium equations for solvent extraction processes have been combined with computer spreadsheets in a new way so that models for very complex multicomponent multistage operations can be setup and used easily. A part of the novelty is the way in which the problem is organized in the spreadsheet. In addition, to facilitate spreadsheet setup, a new calculational procedure has been developed. The resulting Spreadsheet Algorithm for Stagewise Solvent Extraction (SASSE) can be used with either IBM or Macintosh personal computers as a simple yet powerful tool for analyzing solvent extraction flowsheets.

  9. Firing of pulverized solvent refined coal

    DOEpatents

    Lennon, Dennis R.; Snedden, Richard B.; Foster, Edward P.; Bellas, George T.

    1990-05-15

    A burner for the firing of pulverized solvent refined coal is constructed and operated such that the solvent refined coal can be fired successfully without any performance limitations and without the coking of the solvent refined coal on the burner components. The burner is provided with a tangential inlet of primary air and pulverized fuel, a vaned diffusion swirler for the mixture of primary air and fuel, a center water-cooled conical diffuser shielding the incoming fuel from the heat radiation from the flame and deflecting the primary air and fuel steam into the secondary air, and a watercooled annulus located between the primary air and secondary air flows.

  10. 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.}

  11. Optical nonlinearity of HBI in different solvents

    NASA Astrophysics Data System (ADS)

    Wu, Feng; Ma, Lina; Geng, Yaohui; Zhang, Siwen; Wang, Zhe; Cheng, Xiaoman

    2014-04-01

    2-(2'-Hydroxyphenyl) benzimidazole (HBI) is one kind of organic molecules featuring excited-state proton transfer (ESPT). The nonlinear optical properties of 2-(2'-hydroxyphenyl) benzimidazole (HBI) in different polar solvents were investigated by means of Z-scan technique under the excitation of the 1064 nm picoseconds laser pulse. The experimental results show that the nonlinear refractive indices decrease with the enhancement of the polarity of the solvent. The nonlinear refractive indices sensitive to the solvent polarity allow them to be widely used for the optoelectronic devices.

  12. Coal liquefaction with coal tar solvent

    SciTech Connect

    Gir, S.; Rhodes, D.E.

    1986-12-16

    A method is described of liquefying coal, comprising: mixing solid coal with a process solvent comprising coal tar material which has been at least partially hydrogenated under conditions which selectively hydrogenate aromatic coal tar components to hydroaromatics and which preserve the integrity of organonitrogen coal tar components, to produce a coal-solvent slurry; treating the coal-solvent slurry under coal-liquefying conditions in a liquefaction zone to produce a solution containing coal liquefaction products; and recovering coal liquefaction products from the solution.

  13. TRUEX process solvent cleanup with solid sorbents

    SciTech Connect

    Tse, Pui-Kwan; Reichley-Yinger, L.; Vandegrift, G.F.

    1989-01-01

    Solid sorbents, alumina, silica gel, and Amberlyst A-26 have been tested for the cleanup of degraded TRUEX-NPH solvent. A sodium carbonate scrub alone does not completely remove acidic degradation products from highly degraded solvent and cannot restore the stripping performance of the solvent. By following the carbonate scrub with either neutral alumina or Amberlyst A-26 anion exchange resin, the performance of the TRUEX-NPH is substantially restored. The degraded TRUEX-NPH was characterized before and after treatment by supercritical fluid chromatography. Its performance was evaluated by americium distribution ratios, phase-separation times, and lauric acid distribution coefficients. 17 refs., 2 figs., 5 tabs.

  14. 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

  15. Solvent effects on infrared spectra of methyl 4-hydroxybenzoate in pure organic solvents and in ethanol/CCl 4 binary solvents

    NASA Astrophysics Data System (ADS)

    Liu, Qing; Fang, Danjun; Zheng, Jianping

    2004-06-01

    Infrared spectroscopy studies of methyl 4-hydroxybenzoate (MHB) in 17 different organic solvents and in ethanol/CCl 4 binary solvent were undertaken to investigate the solvent-solute interactions. The frequencies of carbonyl stretching vibration ν(CO) of MHB in single solvents were correlated with the solvent acceptor number (AN) and the linear solvation energy relationships (LSER). The assignments of the two bands of ν(CO) of MHB in alcohols and the single one of that in non-alcoholic solvents were discussed. The shifts of ν(CO) of MHB in ethanol/CCl 4 binary solvents showed that several kinds of solute-solvent hydrogen bonding interactions coexisted in the mixture solvents, with a change in the mole fraction of ethanol in the binary solvents.

  16. Interaction of organic solvents with protein structures at protein-solvent interface.

    PubMed

    Khabiri, Morteza; Minofar, Babak; Brezovský, Jan; Damborský, Jiří; Ettrich, Rudiger

    2013-11-01

    The effect of non-denaturing concentrations of three different organic solvents, formamide, acetone and isopropanol, on the structure of haloalkane dehalogenases DhaA, LinB, and DbjA at the protein-solvent interface was studied using molecular dynamics simulations. Analysis of B-factors revealed that the presence of a given organic solvent mainly affects the dynamical behavior of the specificity-determining cap domain, with the exception of DbjA in acetone. Orientation of organic solvent molecules on the protein surface during the simulations was clearly dependent on their interaction with hydrophobic or hydrophilic surface patches, and the simulations suggest that the behavior of studied organic solvents in the vicinity of hyrophobic patches on the surface is similar to the air/water interface. DbjA was the only dimeric enzyme among studied haloalkane dehalogenases and provided an opportunity to explore effects of organic solvents on the quaternary structure. Penetration and trapping of organic solvents in the network of interactions between both monomers depends on the physico-chemical properties of the organic solvents. Consequently, both monomers of this enzyme oscillate differently in different organic solvents. With the exception of LinB in acetone, the structures of studied enzymes were stabilized in water-miscible organic solvents. PMID:22760789

  17. A neurological evaluation of workers exposed to mixtures of organic solvents.

    PubMed Central

    Maizlish, N A; Fine, L J; Albers, J W; Whitehead, L; Langolf, G D

    1987-01-01

    Workers with long term exposure to mixtures of organic solvents below regulatory limits have been reported to experience mild, but clinically detectable, sensory or sensorimotor polyneuropathies. In conjuction with a cross sectional study of behavioural performance a clinical neurological evaluation was conducted among printers and spray painters to examine dose response relations. All 240 subjects completed an occupational history and symptom questionnaire and underwent a clinical neurological examination. On average, subjects had been employed on their current job for six years. Classification of solvent exposure for each subject was based on exposed versus non-exposed job titles and observations during an industrial hygiene walk-through or on the measured concentration of solvents in full shift personal air samples. The average full shift solvent concentration was 302 ppm for printing plant workers and 6-13 ppm for workers at other plants. Isopropanol and hexane were the major constituents. Neurological abnormalities consistent with mild polyneuropathy were found in 16% of subjects; none was clinically significant. Exposed/non-exposed comparisons showed slightly higher frequency of symptoms in the exposed subjects which was not related to solvent level. Subjects categorised as exposed during the walk- through survey also had poorer vibratory sensation measured at the foot and diminished ankle reflexes. In multiple linear regression models, however, controlling for age, sex, alcohol intake, and examiner, no significant (p less than 0.05) relation was found between solvent concentration and poor neurological function except for two point discrimination measured at the foot. This investigation has not provided evidence for dose related adverse neurological effects from exposure to moderately low levels of solvent mixtures for a relatively short duration, although this may be due to the shortness of exposure duration, the type of solvent exposure, or to selection

  18. Employability. NIACE Briefing Sheet 88

    ERIC Educational Resources Information Center

    National Institute of Adult Continuing Education, 2009

    2009-01-01

    Employability skills are central to gaining and keeping employment (e.g. whether paid or unpaid, as an employee or self employed) as well as career progression. The lack of such skills is regularly referred to as one reason for the United Kingdom's often cited long tail of underachievement. Employability skills are at the forefront of government…

  19. Employability Skills Assessment Tool Development

    ERIC Educational Resources Information Center

    Rasul, Mohamad Sattar; Rauf, Rose Amnah Abd; Mansor, Azlin Norhaini; Puvanasvaran, A. P.

    2012-01-01

    Research nationally and internationally found that technical graduates are lacking in employability skills. As employability skills are crucial in outcome-based education, the main goal of this research is to develop an Employability Skill Assessment Tool to help students and lecturers produce competent graduates in employability skills needed by…

  20. Undergraduates' Perceptions of Employer Expectations

    ERIC Educational Resources Information Center

    DuPre, Carrie; Williams, Kate

    2011-01-01

    Research conducted by the National Association of Colleges and Employers (NACE) indicates that employers across industries seek similar skills in job applicants; yet employers often report finding these desired skills lacking in new hires. This study closes the gap in understanding between employer expectations and student perceptions regarding…

  1. Employment in the Public Sector.

    ERIC Educational Resources Information Center

    Organisation for Economic Cooperation and Development, Paris (France).

    This report synthesizes the findings from several areas of work undertaken to assess what impact public sector employment has had on both the level and structure of employment. It also examines the impact of the public sector as employer on the labor market from two viewpoints: the level and share of public sector employment and the structure of…

  2. Employer Sponsorship of Engineering Students.

    ERIC Educational Resources Information Center

    Gordon, Alan; And Others

    1984-01-01

    Surveyed the sponsorship of engineering students by employers by collecting data related to: engineering departments; sponsoring and non-sponsoring employers; student competition for sponsorship; and possible course/university restrictions by employers. Employers offering sponsorships consider them to be of great value in ensuring supplies of…

  3. Clerical Employment and Technological Change.

    ERIC Educational Resources Information Center

    Hunt, H. Allan; Hunt, Timothy

    The potential employment impact of office automation is the topic of the study described in this book. The study reviews trends in clerical employment over the last 30 years in a search for evidence of the impact of changes in process technology on clerical employment levels. Specifically, it examines clerical employment trends from 1950 to 1980…

  4. [Shoe factory workers, solvents and health].

    PubMed

    Foà, Vito; Martinotti, Irene

    2012-01-01

    Exposure to organic solvents in footwear manufacturing industry came from the glues used adhering the shoe parts to each other. Benzene was the first solvent used in shoe factories until the evidence of its capacity to cause leukaemia. Then, the demonstration that exposure to n-hexane was related to distal polyneuropathy limited the use of this substance. After that, results of neurotoxicological studies conducted on workers exposed to different mixtures of organic solvents make necessary prevention measure directed to a progressive reduction of air dispersion of these chemicals. Today exposure to solvents in workplaces is regulated by health based exposure limit values that should warranty absence of central nervous system effects. One of the most important rules of occupational medicine is verify that these exposure levels are really health protective also for workers with increased susceptibility. PMID:22697025

  5. Innovative Technologies for Chlorinated Solvent Remediation

    NASA Astrophysics Data System (ADS)

    Pennell, Kurt D.; Cápiro, Natalie L.

    2014-07-01

    The following sections are included: * INTRODUCTION * TRADITIONAL REMEDIATION TECHNOLOGIES (1980s) * RESEARCH AND DEVELOPMENT OF INNOVATIVE REMEDIATION TECHNOLOGIES (1990s-2000s) * CURRENT TRENDS IN CHLORINATED SOLVENT REMEDIATION (2010s) * CLOSING THOUGHTS * REFERENCES

  6. Volatile Solvent Use among Western Australian Adolescents.

    ERIC Educational Resources Information Center

    Carroll, Annemaree; Houghton, Stephen; Odgers, Peta

    1998-01-01

    Semistructured interviews were conducted with 40 adolescents who reported inhaling volatile solvents. All were aware of the short-term health risks involved in use, and most reported experiencing ill effects. Offers suggestions for intervention. (Author/GCP)

  7. "Solvent Effects" in 1H NMR Spectroscopy.

    ERIC Educational Resources Information Center

    Cavaleiro, Jose A. S.

    1987-01-01

    Describes a simple undergraduate experiment in chemistry dealing with the "solvent effects" in nuclear magnetic resonance (NMR) spectroscopy. Stresses the importance of having students learn NMR spectroscopy as a tool in analytical chemistry. (TW)

  8. SOLVENT EXTRACTION OF ORGANIC WATER POLLUTANTS

    EPA Science Inventory

    Based on experiments with model systems of known organic water pollutants and environmental samples, conclusions are reached concerning the best general solvent for extraction and the most appropriate methods for related manipulations. Chloroform, methylene chloride-ether mixture...

  9. Biological monitoring of chlorinated hydrocarbon solvents

    SciTech Connect

    Monster, A.C.

    1986-08-01

    The possibility of biological monitoring of exposure to some volatile, halogenated hydrocarbons will be discussed. Most of these agents are widely used as solvents. All agents act on the nervous system as narcotics and differ widely in toxicity. Most of the solvents undergo biotransformation to metabolites. This allows biological assessment of exposure by measurement of the solvent and/or metabolites in exhaled air, blood, and/or urine. However, the same metabolites may occur with exposure to different chlorinated hydrocarbons, eg, trichloroethanol and trichloroacetic acid from exposure to trichloroethene, tetrachloroethene, and 1,1,1-trichloroethane. On the other hand, these agents differ widely in the percentage that is metabolized. There are large gaps in our knowledge, however, and much research will have to be carried out before even tentative data can be established for most of the solvents.

  10. United States Air Force Wipe Solvent Testing

    NASA Technical Reports Server (NTRS)

    Hornung, Steven D.; Beeson, Harold D.

    2000-01-01

    The Wright-Patterson Air Force Base (WPAFB), as part of the Air Force Material Command, requested that NASA Johnson Space Center (JSC) White Sands Test Facility (WSTF) conduct testing and analyses in support of the United States Air Force Wipe Solvent Development Project. The purpose of the wipe solvent project is to develop an alternative to be used by Air Force flight line and maintenance personnel for the wipe cleaning of oxygen equipment. This report provides material compatibility, liquid oxygen (LOX) mechanical impact, autogenous ignition temperature (AIT), and gauge cleaning test data for some of the currently available solvents that may be used to replace CFC-113 and methyl chloroform. It provides data from previous WSTF test programs sponsored by the Naval Sea Systems Command, the Kennedy Space Center, and other NASA programs for the purpose of assisting WP AFB in identifying the best alternative solvents for validation testing.

  11. Modelling the effect of solvents on carbohydrates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Carbohydrates are polar molecules and their conformational and anomeric equilibrium can be strongly influenced by solvents. This review provides examples of studies addressing different issues of glycochemistry, such as anomeric equilibrium, conformational changes in rings, modelling of inter-residu...

  12. Deasphalted oil -- A natural asphaltene solvent

    SciTech Connect

    Jamaluddin, A.K.M.; Nazarko, T.W.; Sills, S.; Fuhr, B.J.

    1995-11-01

    Asphaltene deposition in the near-wellbore region can block pore throats, change wettability characteristics and relative-permeability relationships, and therefore, reduce oil production. Conventional aromatic solvents (e.g., toluene, xylene) alone or in combination with various dispersants are used to remove asphaltene damage from the near-wellbore region. However, these aromatic solvents are expensive and are not environmentally friendly. The objective of this work was to systematically evaluate the asphaltene-solvating power of various non conventional solvents, including deasphalted oil, using a light-scattering technique. Experimental results suggest that deasphalted oil is a strong asphaltene solvent presumably because of its native resin and aromatic contents. Addition of asphaltene dispersants also increases the solubilizing power of the deasphalted oil. Furthermore, various refinery and heavy oil upgrader streams show strong ability to solubilize asphaltenes.

  13. Deasphalted oil: A natural asphaltene solvent

    SciTech Connect

    Jamaluddin, A.K.M.; Nazarko, T.W.; Sills, S.; Fuhr, B.J.

    1996-08-01

    Asphaltene deposition in the near-wellbore region can block pore throats, change wettability characteristics and relative-permeability relationships, and therefore, reduce oil production. Conventional aromatic solvents (e.g., toluene and xylene) alone or in combination with various dispersants are used to remove asphaltene damage from the near-wellbore region. However, these aromatic solvents are expensive and are not environmentally friendly. The objective of this work was to systematically evaluate the asphaltene-solvating power of various nonconventional solvents, including deasphalted oil, using a light-scattering technique. Experimental results suggest that deasphalted oil is a strong asphaltene solvent presumably because of its native resin and aromatic contents. Addition of asphaltene dispersants also increases the solubilizing power of the deasphalted oil. Furthermore, various refinery and heavy oil upgrader streams show strong ability to solubilize asphaltenes.

  14. Solvent exposures in screen printing shops.

    PubMed

    Horstman, S W; Browning, S R; Szeluga, R; Burzycki, J; Stebbins, A

    2001-01-01

    A comprehensive description of working conditions, exposure patterns for organic solvents, and related health symptoms among workers in ten small screen printing companies located in Seattle, Washington, is presented. Sampling methods included continuous area monitoring, grab sampling, personal sampling, and time study observation. A total of 27 workers were observed and monitored for solvent exposure. Short-term peak exposures were characterized in terms of magnitude, duration and repetition, and their contribution to time weighted average (TWA) exposures were evaluated. A health questionnaire addressing the symptoms potentially attributable to solvents was used to investigate the possible health effects from exposure. Significant differences in the prevalence of headaches, dizziness, intoxication, and dry skin (p < 0.01) were reported among workers who had some solvent exposure compared with the referent group that was not exposed. Exposed workers were also more likely to report fatigue, loss of strength in the arms and hands, difficulty concentrating, sore throat, and a low alcohol tolerance. The study documented highly variable levels of solvent exposures. Screen printing workers in different companies, while performing the same basic tasks, had time weighted average (TWA) exposures ranging from 2% to 100% of the recommended threshold limit value (TLV) for mixtures. Continuous monitoring indicated that high short-term exposures are responsible for the bulk of TWA exposures. Grab samples and continuous monitoring verified that recommended Short Term Exposure Limits (STEL) for individual solvents may be exceeded on a routine basis. Frequent skin contact with solvents was also observed. Health problems in this industry and other small industries using organic solvents may result from these complex patterns of exposure. PMID:11759907

  15. Water as a Solvent for Life

    NASA Technical Reports Server (NTRS)

    Pohorille, Andrew; Pratt, Lawrence R.

    2015-01-01

    "Follow the water" is our basic strategy in searching for life in the universe. The universality of water as the solvent for living systems is usually justified by arguing that water supports the rich organic chemistry that seeds life, but alternative chemistries are possible in other organic solvents. Here, other, essential criteria for life that have not been sufficiently considered so far, will be discussed.

  16. 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.

  17. Biofiltration of solvent vapors from air

    SciTech Connect

    Oh, Young-sook.

    1993-01-01

    For various industrial solvent vapors, biofiltration promises to offer a cost-effective emission control technology. Exploiting the full potential of this technology will help attain the goals of the Clean Air Act Amendments of 1990. Concentrating on large volumes of volatile industrial solvents, stable multicomponent microbial enrichments capable of growing a mineral medium with solvent vapors as their only source of carbon and energy were obtained from soil and sewage sludge. These consortia were immobilized on an optimized porous solid support (ground peat moss and perlite). The biofilter material was packed in glass columns connected to an array of pumps and flow meters that allowed the independent variation of superficial velocity and solvent vapor concentrations. In various experiments, single solvents, such as methanol, butanol, acetonitrile, hexane and nitrobenzene, and solvent mixtures, such as benzene-toluene-xylene (BTX) and chlorobenzene-o-dichlorobenzene (CB/DCB) were biofiltered with rates ranging from 15 to334 g solvent removed per m[sup 3] filter volume /h. Pressure drops were low to moderate (0-10 mmHg/m) and with periodic replacement of moisture, the biofiltration activity could be maintained for a period of several months. The experimental data on methanol biofiltration were subjected to mathematical analysis and modeling by the group of Dr. Baltzis at NJIT for a better understanding and a possible scale up of solvent vapor biofilters. In the case of chlorobenzenes and nitrobenzene, the biofilter columns had to be operated with water recirculation in a trickling filter mode. To prevent inactivation of the trickling filter by acidity during CB/DCB removal, pH control was necessary, and the removal rate of CB/DCB was strongly influenced by the flow rate of the recyling water. Nitrobenzene removal in a trickling filter did not require pH control, since the nitro group was reduced and volatilized as ammonia.

  18. Process for solvent refining of coal using a denitrogenated and dephenolated solvent

    DOEpatents

    Garg, Diwakar; Givens, Edwin N.; Schweighardt, Frank K.

    1984-01-01

    A process is disclosed for the solvent refining of non-anthracitic coal at elevated temperatures and pressure in a hydrogen atmosphere using a hydrocarbon solvent which before being recycled in the solvent refining process is subjected to chemical treatment to extract substantially all nitrogenous and phenolic constituents from the solvent so as to improve the conversion of coal and the production of oil in the solvent refining process. The solvent refining process can be either thermal or catalytic. The extraction of nitrogenous compounds can be performed by acid contact such as hydrogen chloride or fluoride treatment, while phenolic extraction can be performed by caustic contact or contact with a mixture of silica and alumina.

  19. Solvent dependent photophysical properties of dimethoxy curcumin

    NASA Astrophysics Data System (ADS)

    Barik, Atanu; Indira Priyadarsini, K.

    2013-03-01

    Dimethoxy curcumin (DMC) is a methylated derivative of curcumin. In order to know the effect of ring substitution on photophysical properties of curcumin, steady state absorption and fluorescence spectra of DMC were recorded in organic solvents with different polarity and compared with those of curcumin. The absorption and fluorescence spectra of DMC, like curcumin, are strongly dependent on solvent polarity and the maxima of DMC showed red shift with increase in solvent polarity function (Δf), but the above effect is prominently observed in case of fluorescence maxima. From the dependence of Stokes' shift on solvent polarity function the difference between the excited state and ground state dipole moment was estimated as 4.9 D. Fluorescence quantum yield (ϕf) and fluorescence lifetime (τf) of DMC were also measured in different solvents at room temperature. The results indicated that with increasing solvent polarity, ϕf increased linearly, which has been accounted for the decrease in non-radiative rate by intersystem crossing (ISC) processes.

  20. Solvent dependent photophysical properties of dimethoxy curcumin.

    PubMed

    Barik, Atanu; Indira Priyadarsini, K

    2013-03-15

    Dimethoxy curcumin (DMC) is a methylated derivative of curcumin. In order to know the effect of ring substitution on photophysical properties of curcumin, steady state absorption and fluorescence spectra of DMC were recorded in organic solvents with different polarity and compared with those of curcumin. The absorption and fluorescence spectra of DMC, like curcumin, are strongly dependent on solvent polarity and the maxima of DMC showed red shift with increase in solvent polarity function (Δf), but the above effect is prominently observed in case of fluorescence maxima. From the dependence of Stokes' shift on solvent polarity function the difference between the excited state and ground state dipole moment was estimated as 4.9 D. Fluorescence quantum yield (φ(f)) and fluorescence lifetime (τ(f)) of DMC were also measured in different solvents at room temperature. The results indicated that with increasing solvent polarity, φ(f) increased linearly, which has been accounted for the decrease in non-radiative rate by intersystem crossing (ISC) processes. PMID:23314392

  1. Solvent Extraction and Ion Exchange in Radiochemistry

    NASA Astrophysics Data System (ADS)

    Skarnemark, G.

    In 1805, Bucholz extracted uranium from a nitric acid solution into ether and back-extracted it into pure water. This is probably the first reported solvent-extraction investigation. During the following decades, the distribution of neutral compounds between aqueous phases and pure solvents was studied, e.g., by Peligot, Berthelot and Jungfleisch, and Nernst. Selective extractants for analytical purposes became available during the first decades of the twentieth century. From about 1940, extractants such as organophosphorous esters and amines were developed for use in the nuclear fuel cycle. This connection between radiochemistry and solvent-extraction chemistry made radiochemists heavily involved in the development of new solvent extraction processes, and eventually solvent extraction became a major separation technique in radiochemistry. About 160 years ago, Thompson and Way observed that soil can remove potassium and ammonium ions from an aqueous solution and release calcium ions. This is probably the first scientific report on an ion-exchange separation. The first synthesis of the type of organic ion exchangers that are used today was performed by Adams and Holmes in 1935. Since then, ion-exchange techniques have been used extensively for separations of various radionuclides in trace as well as macro amounts. During the last 4 decades, inorganic ion exchangers have also found a variety of applications. Today, solvent extraction as well as ion exchange are used extensively in the nuclear industry and for nuclear, chemical, and medical research. Some of these applications are discussed in the chapter.

  2. Caustic-Side Solvent Extraction: Chemical and Physical Properties of the Optimized Solvent

    SciTech Connect

    Delmau, L.H.

    2002-10-08

    This work was undertaken to optimize the solvent used in the Caustic Side Solvent Extraction (CSSX) process and to measure key chemical and physical properties related to its performance in the removal of cesium from the alkaline high-level salt waste stored in tanks at the Savannah River Site. The need to adjust the solvent composition arose from the prior discovery that the previous baseline solvent was supersaturated with respect to the calixarene extractant. The following solvent-component concentrations in Isopar{reg_sign} L diluent are recommended: 0.007 M calix[4]arene-bis(tert-octylbenzo-crown-6) (BOBCalixC6) extractant, 0.75 M 1-(2,2,3,3-tetrafluoropropoxy)-3-(4-sec-butylphenoxy)-2-propanol (Cs-7SB) phase modifier, and 0.003 M tri-n-octylamine (TOA) stripping aid. Criteria for this selection included BOBCalixC6 solubility, batch cesium distribution ratios (D{sub Cs}), calculated flowsheet robustness, third-phase formation, coalescence rate (dispersion numbers), and solvent density. Although minor compromises within acceptable limits were made in flowsheet robustness and solvent density, significant benefits were gained in lower risk of third-phase formation and lower solvent cost. Data are also reported for the optimized solvent regarding the temperature dependence of D{sub Cs} in extraction, scrubbing, and stripping (ESS); ESS performance on recycle; partitioning of BOBCalixC6, Cs-7SB, and TOA to aqueous process solutions; partitioning of organic anions; distribution of metals; solvent phase separation at low temperatures; solvent stability to elevated temperatures; and solvent density and viscosity. Overall, the technical risk of the CSSX process has been reduced by resolving previously identified issues and raising no new issues.

  3. Influence of solute-solvent coordination on the orientational relaxation of ion assemblies in polar solvents

    NASA Astrophysics Data System (ADS)

    Ji, Minbiao; Hartsock, Robert W.; Sung, Zheng; Gaffney, Kelly J.

    2012-01-01

    We have investigated the rotational dynamics of lithium thiocyanate (LiNCS) dissolved in various polar solvents with time and polarization resolved vibrational spectroscopy. LiNCS forms multiple distinct ionic structures in solution that can be distinguished with the CN stretch vibrational frequency of the different ionic assemblies. By varying the solvent and the LiNCS concentration, the number and type of ionic structures present in solution can be controlled. Control of the ionic structure provides control over the volume, shape, and dipole moment of the solute, critical parameters for hydrodynamic and dielectric continuum models of friction. The use of solutes with sizes comparable to or smaller than the solvent molecules also helps amplify the sensitivity of the measurement to the short-ranged solute-solvent interaction. The measured orientational relaxation dynamics show many clear and distinct deviations from simple hydrodynamic behavior. All ionic structures in all solvents exhibit multi-exponential relaxation dynamics that do not scale with the solute volume. For Lewis base solvents such as benzonitrile, dimethyl carbonate, and ethyl acetate, the observed dynamics strongly show the effect of solute-solvent complex formation. For the weak Lewis base solvent nitromethane, we see no evidence for solute-solvent complex formation, but still see strong deviation from the predictions of simple hydrodynamic theory.

  4. CHEMICAL STABILITY OF POLYPHENYLENE SULFIDE IN THE NEXT GENERATION SOLVENT FOR CAUSTIC-SIDE SOLVENT EXTRACTION

    SciTech Connect

    Fondeur, F.; Fink, S.

    2011-12-08

    The Office of Waste Processing, within the Office of Technology Innovation and Development, is funding the development of an enhanced solvent for deployment at the Savannah River Site for removal of cesium from High Level Waste. For simplicity, this solvent is referred to as the Next Generation Solvent (NGS). The technical effort is collaboration between Oak Ridge National Laboratory (ORNL), Savannah River National Laboratory (SRNL), and Argonne National Laboratory. The initial deployment target envisioned for the technology was within the Modular Caustic-Side Solvent Extraction Unit (MCU). Deployment of a new chemical within an existing facility requires verification that the chemical components are compatible with the installed equipment. In the instance of a new organic solvent, the primary focus is on compatibility of the solvent with polyphenylene sulfide (PPS), the polymer used in the coalescers within MCU. This report provides the data from exposing PPS polymer to NGS. The test was conducted over a three month period. PPS is remarkably stable in the presence of the next generation solvent. Testing showed no indication of swelling or significant leaching. Preferential sorption of the Modifier on PPS was observed but the same behavior occurs with the baseline solvent. Therefore, PPS coalescers exposed to the NGS are expected to perform comparably to those in contact with the baseline solvent.

  5. Employment outcomes in Massachusetts Clubhouses.

    PubMed

    McKay, Colleen; Johnsen, Mathew; Stein, Reva

    2005-01-01

    Employment outcomes of individuals participating in 17 Massachusetts Clubhouses certified by the International Center for Clubhouse Development were examined through an annual survey. Major components of employment programs in contemporary clubhouses are identified and individual employment outcomes are described. Within contemporary practice in ICCD clubhouses in this sample, clubhouses provided a three-pronged approach to employment. Between 1998-2001, 1702 individuals worked in 2714 separate job placements, employed in Transitional (TE), Supported (SE), and Independent Employment (IE). Forty percent of members with more than one job (N = 385) participated in at least one TE. Individuals with longer memberships tended to work longer and had higher job earnings. PMID:16075694

  6. Effect of surfactant and solvent on spin-lattice relaxation dynamics of magnetic nanocrystals.

    PubMed

    Maiti, Sourav; Chen, Hsiang-Yun; Chen, Tai-Yen; Hsia, Chih-Hao; Son, Dong Hee

    2013-04-25

    The effect of varying the surfactant and solvent medium on the dynamics of spin-lattice relaxation in photoexcited Fe3O4 nanocrystals has been investigated by measuring the time-dependent magnetization employing pump-probe transient Faraday rotation technique. The variation of the surfactants having surface-binding functional groups modified not only the static magnetization but also the dynamics of the recovery of the magnetization occurring via spin-lattice relaxation in the photoexcited Fe3O4 nanocrystals. The variation of the polarity and size of the solvent molecules can also influence the spin-lattice relaxation dynamics. However, the effect is limited to the nanocrystals having sufficiently permeable surfactant layer, where the small solvent molecules (e.g., water) can access the surface and dynamically modify the ligand field on the surface. PMID:23003213

  7. Temporary Employment and Perceived Employability: Mediation by Impression Management

    ERIC Educational Resources Information Center

    De Cuyper, Nele; De Witte, Hans

    2010-01-01

    Perceived employability (PE) has been advanced as the upcoming resource for career development, particularly for temporary workers. The question is how temporary workers become employable. Our hypothesis is that temporary workers more than permanent workers use impression management to become employable, both on the internal and the external labor…

  8. Disability and Supported Employment: Impact on Employment, Income, and Allowances

    ERIC Educational Resources Information Center

    Germundsson, Per; Gustafsson, Johanna; Lind, Martin; Danermark, Berth

    2012-01-01

    In this article, we examine supported employment and its impact on the level of employment, disposable income, and sum of allowances, targeting a group of individuals with disabilities. We have particularly focused on individuals with psychiatric disabilities. Supported employment is a vocational rehabilitation service with an empowerment approach…

  9. A Conceptual Understanding of Employability: The Employers' View in Rwanda

    ERIC Educational Resources Information Center

    Bamwesiga, Penelope Mbabazi

    2013-01-01

    Many governments believe that investing in human capital should increase citizens' employability, which is why it is often presented as a solution to the problems of knowledge-based economies and societies, rising unemployment rates and economic competiveness. The aim of this study is to understand employers' views regarding the employability of…

  10. Orientational dynamics for an amphiphilic-solvent solution

    NASA Astrophysics Data System (ADS)

    Heinzelmann, G.; Figueiredo, W.; Girardi, M.

    2011-02-01

    In this work, we performed Monte Carlo simulations on a lattice model for spontaneous amphiphilic aggregation, in order to study the orientational and hydrogen-bonding dynamics of water on different regions inside the micellar solution. We employed an associating lattice gas model that mimics the aqueous solvent, which presents a rich phase diagram with first- and second-order transition lines. Even though this is a simplified model, it makes possible to investigate the orientational dynamics of water in an equilibrium solution of amphiphiles, as well as the influence of the different phases of the solvent in the interfacial and bulk water dynamics. By means of extensive simulations, we showed that, at high temperatures, the behavior of the orientational relaxation and hydrogen bonding of water molecules in the bulk, first, and second hydration shells are considerable different. We observe the appearance of a very slow component for water molecules in the first hydration shell of micelles when the system reaches a high-density phase, consistent with previous theoretical and experimental studies concerning biological water. Also, at high temperatures, we find that water molecules in the second hydration shell of micelles have an orientational decay similar to that of bulk water, but with a generally slower dynamics. Otherwise, at low temperatures, we have two components for the orientational relaxation of bulk water in the low density liquid phase, and only a single component in the high density liquid (HDL) phase, which reflect the symmetry properties of the different phases of the solvent model. In the very dense region of water molecules in the first hydration shell of micelles at low temperatures, we find two components for the orientational relaxation on both liquid phases, one of them much slower than that in the single component of bulk water in the HDL phase. This happens even though our model does not present any hindrance to the water rotational freedom

  11. Solvent disperser for removing oil from sponge core

    SciTech Connect

    Di Foggio, R.

    1988-09-20

    This patent describes method for dispersing solvent for use in determining the oil saturation of an earth formation by means of sponge coring, comprising: (a) receiving solvent dripping downwardly, and (b) conducting the received solvent by means of capillary action to an application zone located and dimensioned for passing such solvent to the sponge in a sponge core barrel.

  12. COMPUTER-AIDED SOLVENT DESIGN FOR POLLUTION PREVENTION: PARIS II

    EPA Science Inventory

    Solvent substitution is an attractive way of elijminating the use of regulated solvents because it usually does not require major chanages in existing processes, equipment or operations. Successful solvent substitution is dependent on finding solvents that are as effective or be...

  13. Spontaneous vesicle formation in a deep eutectic solvent.

    PubMed

    Bryant, Saffron J; Atkin, Rob; Warr, Gregory G

    2016-02-14

    Solvent penetration experiments and small-angle X-ray scattering reveal that phospholipids dissolved in a deep eutectic solvent (DES) spontaneously self-assemble into vesicles above the lipid chain melting temperature. This means DESs are one of the few nonaqueous solvents that mediate amphiphile self-assembly, joining a select set of H-bonding molecular solvents and ionic liquids. PMID:26701210

  14. Veterans' Employment and Training Service

    MedlinePlus

    ... Engage Facebook Twitter Instagram RSS Email Share Veterans' Employment and Training Service (VETS) Menu About VETS Who ... STAY CONNECTED Tweets by @USDOL Tweets by @LaborSec Employment Initiatives Contact your local American Job Center for ...

  15. Quantification of Solvent Contribution to the Stability of Noncovalent Complexes.

    PubMed

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

    2013-10-01

    We introduce an indirect approach to estimate the solvation contributions to the thermodynamics of noncovalent complex formation through molecular dynamics simulation. This estimation is demonstrated by potential of mean force and entropy calculations on the binding process between β-cyclodextrin (host) and four drug molecules puerarin, daidzin, daidzein, and nabumetone (guest) in explicit water, followed by a stepwise extraction of individual enthalpy (ΔH) and entropy (ΔS) terms from the total free energy. Detailed analysis on the energetics of the host-guest complexation demonstrates that flexibility of the binding partners and solvation-related ΔH and ΔS need to be included explicitly for accurate estimation of the binding thermodynamics. From this, and our previous work on the solvent dependency of binding energies (Zhang et al. J. Phys. Chem. B 2012, 116, 12684-12693), it follows that calculations neglecting host or guest flexibility, or those employing implicit solvent, will not be able to systematically predict binding free energies. The approach presented here can be readily adopted for obtaining a deeper understanding of the mechanisms governing noncovalent associations in solution. PMID:26589169

  16. Towards ultra-fast solvent evaporation, the development of a computer controlled solvent vapor annealing chamber

    NASA Astrophysics Data System (ADS)

    Nelson, Gunnar; Wong, J.; Drapes, C.; Grant, M.; Baruth, A.

    Despite the promise of cheap and fast nanoscale ordering of block polymer thin films via solvent vapor annealing, a standardized, scalable production scheme remains elusive. Solvent vapor annealing exposes a nano-thin film to the vapors of one or more solvents with the goal of forming a swollen and mobile state to direct the self-assembly process by tuning surface energies and mediating unfavorable chain interactions. We have shown that optimized annealing conditions, where kinetic and thermal properties for crystal growth are extremely fast (<1s), exist at solvent concentrations just below the order-disorder transition of the film. However, when investigating the propagation of a given morphology into the bulk of a film during drying, the role of solvent evaporation comes under great scrutiny. During this process, the film undergoes a competition between two fronts; phase separation and kinetic trapping. Recent results in both theory and experiment point toward this critical element in controlling the resultant morphologies; however, no current method includes a controllable solvent evaporation rate at ultra-fast time scales. We report on a computer-controlled, pneumatically actuated chamber that provides control over solvent evaporation down to 15 ms. Furthermore, in situ spectral reflectance monitors solvent concentration with 10 ms temporal resolution and reveals several possible evaporation trajectories, ranging from linear to exponential to logarithmic. Funded by Dr. Randolph Ferlic Summer Research Scholarship and NASA Nebraska Space Grant.

  17. Changes in psychological performances of solvent-poisoned and solvent-exposed workers

    SciTech Connect

    Lindstroem, K.

    1980-01-01

    The changes in psychological performances associated with long-term exposure to organic solvents and solvent mixtures were studied in a group of 56 male workers diagnosed as having an occupational disease caused by solvents. Their mean duration of exposure was 9.1 +/- SD 8.3 years, and they were exposed mainly to halogenated and aromatic hydrocarbons and to mixtures of paint solvents. The psychological performances of these solvent-exposed patients were compared with those of 98 styrene-exposed workers and a nonexposed group of 43 construction workers. The applied psychological test variables were factor analyzed, before other statistical analysis, in order to clarify what they measured in the present study. The solvent-exposed group was characterized by a decline in visuomotor performance and decreased freedom from distractibility. The poor visuomotor performances were also related to the long duration of solvent exposure in this group of patients. The index applied for the exposure level revealed no significant relationships to psychological performances among the solvent-exposed patients. The psychological performances of the styrene-exposed group differed only very slightly from those of the nonexposed workers.

  18. Chlorinated solvent replacements recycle/recovery review report

    SciTech Connect

    Beal, M.; Hsu, D.; McAtee, R.E.; Weidner, J.R.; Berg, L.; McCandless, F.P.; Waltari, S.; Peterson, C.

    1992-08-01

    This report is a literature review of waste solvents recycle/recovery methods and shows the results of solvent separations using membrane and distillation technologies. The experimental solvent recovery methods were conducted on solvent replacements for chlorinated solvents at Montana State University. The literature review covers waste solvents separation using distillation, membranes decantation, filtration, carbon adsorption, solvent extraction, and other vapor-phase separation techniques. The results of this study identify solvent distillation methods as the most common separation technique. The alternative separation methods typically supplement distillation. The study shows the need for industries to identify waste solvent disposal methods and investigate the economics of waste solvent recycling as a possible waste reduction method.

  19. Association between maternal occupational exposure to organic solvents and congenital heart defects, National Birth Defects Prevention Study, 1997–2002

    PubMed Central

    Gilboa, SM; Desrosiers, TA; Lawson, CC; Lupo, PJ; Riehle-Colarusso, T; Stewart, PA; van Wijngaarden, E; Waters, MA; Correa, A

    2015-01-01

    Objective To examine the relation between congenital heart defects (CHDs) in offspring and estimated maternal occupational exposure to chlorinated solvents, aromatic solvents, and Stoddard solvent during the period from one month before conception through the first trimester. Methods The study population included mothers of infants with simple, isolated CHDs and mothers of control infants who delivered from 1997 through 2002 and participated in the National Birth Defects Prevention Study. Two methods to assess occupational solvent exposure were employed: an expert consensus-based approach and a literature-based approach. Multiple logistic regression was used to calculate adjusted odds ratios (OR) and 95% confidence intervals (CI) for the association between solvent classes and CHDs. Results 2,951 control mothers and 2,047 CHD case mothers were included. Using the consensus-based approach, associations were observed for exposure to any solvent and any chlorinated solvent with perimembranous ventricular septal defects (OR 1.6; 95% CI 1.0 to 2.6 and OR 1.7; 95% CI 1.0 to 2.8 respectively). Using the literature-based approach, associations were observed for: any solvent exposure with aortic stenosis (OR 2.1; 95% CI 1.1 to 4.1); and Stoddard solvent exposure with d-transposition of the great arteries (OR 2.0; 95% CI 1.0 to 4.2), right ventricular outflow tract obstruction defects (OR 1.9; 95% CI 1.1 to 3.3), and pulmonary valve stenosis (OR 2.1; 95% CI 1.1 to 3.8). Conclusions We found evidence of associations between occupational exposure to solvents and several types of CHDs. These results should be interpreted in light of the potential for misclassification of exposure. PMID:22811060

  20. Non-aqueous cleaning solvent substitution

    SciTech Connect

    Meier, G.J.

    1994-01-01

    A variety of environmental, safety, and health concerns exist over use of chlorinated and fluorinated cleaning solvents. Sandia National Laboratories, Lawrence Livermore National Laboratories, and the Kansas City Division of Allied Signal have combined efforts to focus on finding alternative cleaning solvents and processes which are effective, environmentally safe, and compliant with local, state, and federal regulations. An alternative solvent has been identified, qualified, and implemented into production of complex electronic assemblies, where aqueous and semi-aqueous cleaning processes are not allowed. Extensive compatibility studies were performed with components, piece-parts, and materials. Electrical testing and accelerated aging were used to screen for detrimental, long-term effects. A terpene, d-limonene, has been selected as the solvent of choice, and has been found to be compatible with the components and materials tested. A brief history of the overall project will be presented, along with representative cleaning efficiency results, compatibility results, and residual solvent data. The electronics industry is constantly searching for proven methods and environmentally safe materials to use in manufacturing processes. The information in this presentation will provide another option to consider on future projects for applications requiring high levels of quality, reliability, and cleanliness from non-aqueous cleaning processes.

  1. Non-aqueous cleaning solvent substitution

    NASA Technical Reports Server (NTRS)

    Meier, Gerald J.

    1994-01-01

    A variety of environmental, safety, and health concerns exist over use of chlorinated and fluorinated cleaning solvents. Sandia National Laboratories, Lawrence Livermore National Laboratories, and the Kansas City Division of AlliedSignal have combined efforts to focus on finding alternative cleaning solvents and processes which are effective, environmentally safe, and compliant with local, state, and federal regulations. An alternative solvent has been identified, qualified, and implemented into production of complex electronic assemblies, where aqueous and semi-aqueous cleaning processes are not allowed. Extensive compatibility studies were performed with components, piece-parts, and materials. Electrical testing and accelerated aging were used to screen for detrimental, long-term effects. A terpene, d-limonene, was selected as the solvent of choice, and it was found to be compatible with the components and materials tested. A brief history of the overall project will be presented, along with representative cleaning efficiency results, compatibility results, and residual solvent data. The electronics industry is constantly searching for proven methods and environmentally-safe materials to use in manufacturing processes. The information in this presentation will provide another option to consider on future projects for applications requiring high levels of quality, reliability, and cleanliness from non-aqueous cleaning processes.

  2. Solvent gating of intramolecular electron transfer

    SciTech Connect

    Miller, R.M. ); Spears, K.G.; Gong, J.H.; Wach, M. )

    1994-02-03

    The rates for ionic photodissociation of malachite green leucocyanide to form cyanide ion and a malachite green carbonium ion were measured as a function of solvent and temperature. The observed rates in mixtures of polar and nonpolar solvents all had an activation energy of about 1 kcal/mol for a wide range of dielectric constants. This dissociative intramolecular electron transfer (DIET) is unusual because it is the first example where solvent configurational entropy changes are required to enable a large amplitude molecular distortion leading to a nonadiabatic electron transfer and ionic dissociation. This solvent gated intramolecular electron-transfer mechanism is supported by analysis of the preexponential and activation energy trends in dipolar aprotic solven mixtures and alcohol solvents. The large amplitude motion is not separately measurable due to the slow gating rates, but viscosity effects on both the preexponential and the activation energy are analyzed to demonstrate consistency with a barrierless diffusion model having a structural dependence on electron-transfer rate. The rate has an inverse dependence on viscosity raised to the 0.53 power. 36 refs., 6 figs., 4 tabs.

  3. Catalytic thermometric titrations in non-aqueous solvents by coulometrically generated titrant.

    PubMed

    Vajgand, V J; Gaál, F F; Brusin, S S

    1970-05-01

    Catalytic thermometric titrations have been developed for tertiary amines and salts of organic acids in acetic and propionic anhydride with titrant coulometrically generated at a mercury and/or platinum anode, hydroquinone being added to the solution titrated if the platinum anode is used. The results obtained are compared with those obtained by coulometric titration with the end-point detected either photometrically or potentiometrically. On a élaboré des titrages thermométriques catalytiques pour les amines tertiaires et les sels d'acides organiques en anhydrides aétique et propionique avec l'agent de titrage engendré coulométriquement sur une anode de mercure et/ou platine, de l'hydroquinone étant ajoutée à la solution titrée si l'on emploie l'anode de platine. Les résultats obtenus sont comparés avec ceux obtenus par titrage coulométrique avec le point de fin de réaction détecté soit photométriquement soit potentioétriquement. PMID:18960753

  4. Ion Exchange and Solvent Extraction: Supramolecular Aspects of Solvent Exchange Volume 21

    SciTech Connect

    Gloe, Karsten; Tasker, Peter A; Oshima, Tatsuya; Watarai, Hitoshi; Nilsson, Mikael

    2013-01-01

    inverse micelles swollen with water molecules. Extraction systems involving long-chain cations such as alkylammonium species or long-chain anions such as sulfonates or carboxylates proved especially prone to extensive aggregate formation. The related phenomenon of third-phase formation in SX systems, long misunderstood, is now yielding to spectroscopic and scattering techniques showing extensive long-range organization. Over the last 50 years, tools for studying the structure and thermodynamics of aggregation have grown increasingly sophisticated, leading to a rich and detailed understanding of what we can now recognize as SC phenomena in SX. In the 1970s and 1980s, the rapid growth of SC elicited a paradigm shift in SX. The influence of SC principles had two major effects on the course of SX research. First, it provided a framework for understanding the supramolecular behavior that was already well appreciated in the field of SX, though earlier without the SC terminology. Second, it provided the conceptual tools to control supramolecular behavior in SX, direct it for intended functionality, and to simplify it. Extraction by designed reagents has been steadily progressing ever since, with commercial applications emerging to successfully validate this approach. With the discovery of crown ethers in the late 1960s, the advancement of extractant design has fruitfully employed the concept of inclusion. While considerable initial progress occurred with such molecules, especially because of their affinity and selectivity for alkali and alkaline earth metals, other molecular platforms such as calixarenes have proven more versatile. Multidentate receptors for partial to full inclusion of cations, anions, ion pairs, as well as neutral species, have now become commonplace for selective extraction. This volume of Ion Exchange and Solvent Extraction examines how the principles of SC are being employed both in advancing the design of new highly selective SX systems and in

  5. Supported Employment Research: A Commentary.

    ERIC Educational Resources Information Center

    Szymanski, Edna Mora; Parker, Randall M.

    1987-01-01

    Addresses problems with the definition of terms and validity of results of research on supported employment. Draws conclusions regarding the state of supported employment research. Comments on the value of retaining flexibility in the concept of supported employment in meeting the needs of consumers. (Author/NB)

  6. Employment Impact of Electronic Business.

    ERIC Educational Resources Information Center

    Hecker, Daniel E.

    2001-01-01

    Electronic business is stimulating employment in some sectors across industries, such as computer-related and customer service occupations, and diminishing employment in others, such as administrative support and marketing/sales. Similarly, employment impacts will vary by industry. (Contains 56 notes and references.) (SK)

  7. Re-Employment Opportunity Center.

    ERIC Educational Resources Information Center

    Mann, Michelle; And Others

    The Washington State Employment Security Department and Columbia Basin Community College have been partners in delivering training, education, and re-employment services at the Re-Employment Opportunity Center (ROC). The ROC targets dislocated workers, especially those affected by downsizing at the Department of Energy, and provides retraining,…

  8. 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

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  9. 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

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  10. 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

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  11. 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

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  12. 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

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  13. 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

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  14. 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... manufacturer's formulation data. Solvent/solvent blend CAS. No. Averageorganic HAP mass fraction...

  15. 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

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  16. 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

    ... 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. Average organic HAP mass fraction Typical organic HAP, percent by mass...

  17. 40 CFR Table 4 to Subpart Oooo of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

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    2012-07-01

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  18. 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

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  19. 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

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  20. 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

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  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

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  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 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...

  8. 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...

  9. 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... 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 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,...

  11. 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...

  12. Removal of ionic dyes from water by solvent extraction using reverse micelles.

    PubMed

    Pandit, P; Basu, S

    2004-04-15

    Several methods (e.g., UV/H2O2 oxidation, adsorption, flocculation-precipitation) are normally employed to remove dye from water. A new technique based on liquid/liquid extraction using reverse micelles is proposed whereby recovery of solvent and reuse of dye is possible. Experiments were conducted by mixing a known quantity of dye in aqueous phase and solvent-containing surfactants in a simple mixer. The separation of solvent phase, containing encapsulated dye in reverse micelles, from aqueous phase due to gravity results in separation of dye from water. The removal of different ionic dyes (e.g., eosin yellow, methylene blue, malachite green, methyl orange, orange G) from aqueous phase in the presence of different cationic and anionic surfactants [e.g., sodium dodecylbenzene sulfonate, sodium bis(2-ethylhexyl) sulfosuccinate, hexadecyltrimethylammonium bromide, and cetyl pyridinium chloride] in different solvents (e.g., amyl alcohol, benzyl alcohol, methyl benzoate, and isooctane) were studied by conducting experiments. The percentage removal of dye from aqueous phase increases with the decrease in dye concentration or with the increase in surfactants concentration. Furthermore, the percentage COD removal of dye is increased with the increase in surfactant concentration. The nature of solvent has minimal effect on percentage removal of dye. The ratio of solventto aqueous phase volume required for the removal of dye decreases with the increase in surfactant concentration. It is possible to back-extract dye into aqueous phase and recover solvent by using counterionic surfactants. The separation of aqueous phase from the aqueous-phase solvent dispersion is faster for amyl alcohol as compared to benzyl alcohol and methyl benzoate. A theoretical model based on ion-exchange reaction between surfactants and dye is used to analyze the experimental data. PMID:15116851

  13. Active-site motions and polarity enhance catalytic turnover of hydrated subtilisin dissolved in organic solvents.

    PubMed

    Hudson, Elton P; Eppler, Ross K; Beaudoin, Julianne M; Dordick, Jonathan S; Reimer, Jeffrey A; Clark, Douglas S

    2009-04-01

    The enzyme subtilisin Carlsberg was surfactant-solubilized into two organic solvents, isooctane and tetrahydrofuran, and hydrated through stepwise changes in the thermodynamic water activity, a(w). The apparent turnover number k(cat)(app) in these systems ranged from 0.2 to 80 s(-1) and increased 11-fold in isooctane and up to 50-fold in tetrahydrofuran with increasing a(w). (19)F NMR relaxation experiments employing an active-site inhibitor were used to assess the dependence of active-site motions on a(w). The rates of NMR-derived fast (k > 10(7) s(-1)) and slow (k < 10(4) s(-1)) active-site motions increased in both solvents upon hydration, but only the slow motions correlated with k(cat). The (19)F chemical shift was a sensitive probe of the local electronic environment and provided an empirical measure of the active-site dielectric constant epsilon(as), which increased with hydration to epsilon(as) approximately 13 in each solvent. In both solvents, the transition state free energy data and epsilon(as) followed Kirkwood's model for the continuum solvation of a dipole, indicating that water also enhanced catalysis by altering the active-site's electronic environment and increasing its polarity to better stabilize the transition state. These results reveal that favorable dynamic and electrostatic effects both contribute to accelerated catalysis by solubilized subtilisin Carlsberg upon hydration in organic solvents. PMID:19317505

  14. Active-site motions and polarity enhance catalytic turnover of hydrated subtilisin dissolved in organic solvents

    PubMed Central

    Hudson, Elton P; Eppler, Ross K; Beaudoin, Julianne M; Dordick, Jonathan S; Reimer, Jeffrey A; Clark, Douglas S

    2009-01-01

    The enzyme subtilisin Carlsberg was surfactant-solubilized into two organic solvents, isooctane and tetrahydrofuran, and hydrated through stepwise changes in the thermodynamic water activity, aw. The apparent turnover number kcatapp in these systems ranged from 0.2 to 80 s−1 and increased 11-fold in isooctane and up to 50-fold in tetrahydrofuran with increasing aw. 19F-NMR relaxation experiments employing an active-site inhibitor were used to assess the dependence of active-site motions on aw. The rates of NMR-derived fast (k > 107 s−1) and slow (k < 104 s−1) active-site motions increased in both solvents upon hydration, but only the slow motions correlated with kcat. The 19F chemical shift was a sensitive probe of the local electronic environment and provided an empirical measure of the active-site dielectric constant εas, which increased with hydration to εas ≈ 13 in each solvent. In both solvents the transition state free energy data and εas followed Kirkwood’s model for the continuum solvation of a dipole, indicating that water also enhanced catalysis by altering the active-site’s electronic environment and increasing its polarity to better stabilize the transition state. These results reveal that favorable dynamic and electrostatic effects both contribute to accelerated catalysis by solubilized subtilisin Carlsberg upon hydration in organic solvents. PMID:19317505

  15. Solvent-Dictated Lithium Sulfur Redox Reactions: An Operando UV-vis Spectroscopic Study.

    PubMed

    Zou, Qingli; Lu, Yi-Chun

    2016-04-21

    Fundamental understanding of solvent's influence on Li-S redox reactions is required for rational design of electrolyte for Li-S batteries. Here we employ operando UV-vis spectroscopy to reveal that Li-S redox reactions in high-donor-number solvents, for example, dimethyl sulfoxide (DMSO), undergo multiple electrochemical and chemical reactions involving S8(2-), S6(2-), S4(2-), and S3(•-), where S3(•-) is the most stable and dominant reaction intermediate. In low-donor-number solvents, for example, 1,3-dioxolane:1,2-dimethoxyethane, the dominant reaction intermediate, is found to be S4(2-). The stability of these main polysulfide intermediates determines the reaction rates of the disproportionation/dissociation/recombination of polysulfides and thereby affects the reaction rates of the Li-S batteries. As an example, we show that dimethylformamide, a high-donor-number solvent, which exhibits stronger stabilization of S3(•-) compared with DMSO, significantly reduces Li-S cell polarization compared with DMSO. Our study reveals solvent-dependent Li-S reaction pathways and highlights the role of polysulfide stability in the efficiency of Li-S batteries. PMID:27050386

  16. Neurologic effects of solvents in older adults. (UW retired worker study). Final performance report

    SciTech Connect

    Daniell, W.E.

    1993-11-12

    The possibility that previous occupational exposure to solvents might be associated with clinically significant neurological dysfunction in older adults was investigated in a cross-sectional study. Subjects included 67 painters, 22 aerospace painters and fuel cell sealers, and a comparison group of 126 carpenters. All subjects had retired from regular employment at least 1 year prior to the study. As measured by semiquantitative exposure index, the cumulative histories of lifetime occupational solvent exposure were on the average comparable in the two exposed study groups, painters and aerospace workers. The carpenters differed from the other groups in solvent exposure by several orders of magnitude. The painters had a significantly higher history of consuming alcoholic beverages than did the other two study groups. The painters had a significantly higher score on the Beck Depression Inventory, a measure of current depressive symptoms. The painters reported significantly more general neurologic symptoms than did the other two groups. The aerospace workers showed much greater evidence of possible adverse effects from former solvent exposure on current neuropsychological function than did the painters when determined by reasoning and memory tests, memory visual motor speed and motor tests. No evidence of persistent effects on liver or renal excretory function was seen in solvent exposed subjects.

  17. Translational diffusion in mixtures of imidazolium ILs with polar aprotic molecular solvents.

    PubMed

    Marekha, Bogdan A; Kalugin, Oleg N; Bria, Marc; Buchner, Richard; Idrissi, Abdenacer

    2014-05-22

    Self-diffusion coefficients of cations and solvent molecules were determined with (1)H NMR in mixtures of 1-n-butyl-3-methylimidazolium (Bmim(+)) tetrafluoroborate (BF4(-)), hexafluorophosphate (PF6(-)), trifluoromethanesulfonate (TfO(-)), and bis(trifluoromethylsulfonyl)imide (TFSI(-)) with acetonitrile (AN), γ-butyrolactone (γ-BL), and propylene carbonate (PC) over the entire composition range at 300 K. The relative diffusivities of solvent molecules to cations as a function of concentration were found to depend on the solvent but not on the anion (i.e., IL). In all cases the values exhibit a plateau at low IL content (x(IL) < 0.2) and then increase steeply (AN), moderately (γ-BL), or negligibly (PC) at higher IL concentrations. This behavior was related to the different solvation patterns in the employed solvents. In BmimPF6-based systems, anionic diffusivities were followed via (31)P nuclei and found to be higher than the corresponding cation values in IL-poor systems and lower in the IL-rich region. The inversion point of relative ionic diffusivities was found around equimolar composition and does not depend on the solvent. At this point, a distinct change in the ion-diffusion mechanism appears to take place. PMID:24792375

  18. Ionic liquid solutions as extractive solvents for value-added compounds from biomass

    PubMed Central

    Passos, Helena; Freire, Mara G.; Coutinho, João A. P.

    2014-01-01

    In the past few years, the number of studies regarding the application of ionic liquids (ILs) as alternative solvents to extract value-added compounds from biomass has been growing. Based on an extended compilation and analysis of the data hitherto reported, the main objective of this review is to provide an overview on the use of ILs and their mixtures with molecular solvents for the extraction of value-added compounds present in natural sources. The ILs (or IL solutions) investigated as solvents for the extraction of natural compounds, such as alkaloids, flavonoids, terpenoids, lipids, among others, are outlined. The extraction techniques employed, namely solid–liquid extraction, and microwave-assisted and ultrasound-assisted extractions, are emphasized and discussed in terms of extraction yields and purification factors. Furthermore, the evaluation of the IL chemical structure and the optimization of the process conditions (IL concentration, temperature, biomass–solvent ratio, etc.) are critically addressed. Major conclusions on the role of the ILs towards the extraction mechanisms and improved extraction yields are additionally provided. The isolation and recovery procedures of the value-added compounds are ascertained as well as some scattered strategies already reported for the IL solvent recovery and reusability. Finally, a critical analysis on the economic impact versus the extraction performance of IL-based methodologies was also carried out and is here presented and discussed. PMID:25516718

  19. Dispersion and coalescence of oil droplets by ultrasound and application for solvent extraction of gallium

    NASA Astrophysics Data System (ADS)

    Yasuda, Keiji; Thanh Nguyen, Tam; Okura, Risa; Nakayama, Shingo; Asakura, Yoshiyuki; Jin, Jiye

    2015-07-01

    To improve the performance of solvent extraction of rare metals, the effects of ultrasonic and organic solvent conditions on the demulsification of emulsions were examined. Optimized conditions were adopted in the solvent extraction of gallium by ultrasonic irradiation. As organic solvents, chloroform, 1,2-dichloromethane, p-bromotoluene, bromobenzene, and 1,2-dibromoethane were employed. Emulsification was carried out using a horn-type transducer at 20 kHz. Demulsification was performed with plate-type transducers at 1.0-4.8 MHz. The demulsification time decreased with increasing ultrasonic frequency and power because the primary and secondary acoustic forces of droplets become stronger. Inclining the vessel shortened the demulsification time. In the case of chloroform at a low solution pH, the demulsification time was shortest since the zeta potential of droplets was close to zero. The sequential ultrasonic irradiation at 20 kHz and 4.8 MHz greatly shortens the operation time needed for solvent extraction of gallium from an aqueous solution.

  20. Solubility of C[sub 60] in a variety of solvents

    SciTech Connect

    Ruoff, R.S.; Tse, D.S.; Malhotra, R.; Lorents, D.C. )

    1993-04-01

    The room temperature solubility of pure C[sub 60] has been determined in 47 solvents. The solubilities cover a wide range, from 0.01 mg/mL in methanol to 50 mg/mL in 1-chloronaphthalene. The solubilities in CS[sub 2], toluene, and hexane, three of the commonly employed solvents, are 7.9, 2.8, and 0.04 mg/mL, respectively. An examination of the solubilities of C[sub 60] as a function of the solvent properties such as index of refraction, dielectric constant, molecular size, Hildebrand solubility parameter, and H-bonding strength reaffirms the century-old principle like dissolves like. No single solvent parameter can uniformly predict the solubility of C[sub 60], but a composite picture of solvents with high solubility for C[sub 60] emerges: large index of refraction, dielectric constant around 4, large molecular volume, Hildebrand solubility parameter equal to 10 cal[sup 1/2] cm[sup [minus]3/2], and tendency to act as a moderate strength nucleophile. 18 refs., 4 figs., 1 tab.

  1. High-repetition-rate, narrow-band dye lasers with water as a solvent for dyes

    NASA Astrophysics Data System (ADS)

    Ray, Alok K.; Sinha, Sucharita; Kundu, Soumitra; Kumar, Sasi; Nair, Sivagiriyal Karunakaran Sreenivasan; Pal, Tamal; Dasgupta, Kamalesh

    2002-03-01

    The performance of a copper vapor laser-pumped narrow-band dye laser in oscillator-amplifier configuration with water-based binary mixture solvents is described. Although oscillator efficiency in water-surfactant (sodium lauryl sulfate) solvent was comparable with that that employed pure ethanolic solvent, amplifier efficiency was found to be lower. Experiments that were carried out with vertically polarized pump beams and either horizontally or vertically polarized signal beams show that, in case of both the pump and signal having orthogonal polarization (horizontal) and same polarization (vertical), the extraction efficiency for both ethanolic and water-micelle media increased substantially from 15.7% to 18.5% and from 10% to 12.5%, respectively. However, the relative difference remained nearly the same, indicating that a slower orientational diffusion of excited dye molecules in a micellar medium is not responsible for a decrease in amplifier efficiency. Amplifier efficiency comparable with that containing ethanolic dye solutions could be obtained with a binary solvent that comprises a mixture of water and about 30% n-propanol. The performances of two efficient dyes, Rhodamine-6G and Kiton Red S, using water-based solvents were studied.

  2. Relative efficiency of solvents used in endodontics.

    PubMed

    Hansen, M G

    1998-01-01

    A root canal model was used to test the relative efficiency of various commonly used endodontic solvents including eucalyptol, eucalyptus oil, orange oil, chloroform, and xylene to dissolve or soften gutta-percha and several different types of sealers (Proco-Sol, AH26, and Sealapex). There was no significant difference in the ability of the solvents to dissolve gutta-percha and the zinc oxide-eugenol-based sealer Proco-Sol. The resin-based sealer, AH26, was only dissolved in chloroform and took considerable time (> 30 min). The calcium hydroxide-based sealer, Sealapex, could not be tested because it was found not to set at all unless in contact with air. All of the solvents for both Proco-Sol and gutta-percha produced clinically acceptable dissolving times. PMID:9487865

  3. Thermal Characterization of Nanofluids with Different Solvents

    NASA Astrophysics Data System (ADS)

    Jiménez-Pérez, J. L.; Cruz-Orea, A.; Sánchez-Ramírez, J. F.; Sánchez-Sinencio, F.; Martínez-Pérez, L.; López Muñoz, G. A.

    2009-08-01

    Thermal lens spectrometry (TLS) and photopyroelectric (PPE) techniques were used to obtain the thermal diffusivity and effusivity of different nanofluid samples. The thermal effusivity of these samples was obtained by the PPE technique in a front detection configuration. In the case of the determination of the thermal diffusivity, TLS was used for the different solvents in the presence of gold nanoparticles (nanofluids). In this technique, an Ar+ laser and intensity stabilized He-Ne laser were used as the heating source and probe beam, respectively. The experimental results showed that thermal diffusivity values of the studied solvents (water, ethanol, and ethylene glycol) were enhanced by the presence of gold nanoparticles. Comparisons with literature values show good agreement with pure solvents. These techniques are applicable for all kind of liquid samples, including semitransparent ones.

  4. Hazardous Solvent Substitution Data System tutorial

    SciTech Connect

    Twitchell, K.E.; Skinner, N.L.

    1993-07-01

    This manual is the tutorial for the Hazardous Solvent Substitution Data System (HSSDS), an online, comprehensive system of information on alternatives to hazardous solvents and related subjects. The HSSDS data base contains product information, material safety data sheets, toxicity reports, usage reports, biodegradable data, product chemical element lists, and background information on solvents. HSSDS use TOPIC{reg_sign} to search for information based on a query defined by the user. TOPIC provides a full text retrieval of unstructured source documents. In this tutorial, a series of lessons is provided that guides the user through basic steps common to most queries performed with HSSDS. Instructions are provided for both window-based and character-based applications.

  5. Modeling organic solvents permeation through protective gloves.

    PubMed

    Chao, Keh-Ping; Wang, Ven-Shing; Lee, Pak-Hing

    2004-02-01

    Several researchers have studied the diffusion of organic solvents through chemical protective gloves and have estimated the diffusion coefficients by using various models. In this study, permeation experiments of benzene, toluene, and styrene through nitrile and Neoprene gloves were conducted using the ASTM F-739 standard test method. The diffusion coefficients were estimated using several models from the literature. Using a one-dimensional diffusion equation based on Fick's second law and the estimated diffusion coefficients, the permeation concentrations were simulated and compared with the experimental results. The modeling results indicated that the solubility of the solvent in the glove materials obtained by immersion tests was not an appropriate boundary condition for organic solvent permeation through the polymer gloves. The modeling work of this study will assist industrial hygienists to assess exposure of chemicals to workers through the chemical protective gloves. PMID:15204879

  6. The Generally Useful Estimate of Solvent Systems (GUESS) method enables the rapid purification of methylpyridoxine regioisomers by countercurrent chromatography.

    PubMed

    Liu, Yang; Friesen, J Brent; Klein, Larry L; McAlpine, James B; Lankin, David C; Pauli, Guido F; Chen, Shao-Nong

    2015-12-24

    The TLC-based Generally Useful Estimate of Solvent Systems (GUESS) method was employed for countercurrent chromatography solvent system selection, in order to separate the three synthetic isomers: 3-O-methylpyridoxine, 4'-O-methylpyridoxine (ginkgotoxin), and 5'-O-methylpyridoxine. The Rf values of the three isomers indicated that ChMWat+2 (chloroform-methanol-water 10:5:5, v/v/v) was appropriate for the countercurrent separation. The isomer separation was highly selective and demonstrated that the TLC-based GUESS method can accelerate solvent system selection for countercurrent separation. Accordingly, the study re-emphasizes the practicality of TLC as a tool to facilitate the rapid development of new countercurrent and centrifugal partition chromatography methods for this solvent system. Purity and structure characterization of all samples was performed by quantitative (1)H NMR. PMID:26680272

  7. A comprehensive classification of solvent systems used for natural product purifications in countercurrent and centrifugal partition chromatography.

    PubMed

    Skalicka-Woźniak, Krystyna; Garrard, Ian

    2015-11-01

    Using both library paper copies and modern electronic copies, every known, published, English-language journal paper that employs either countercurrent or centrifugal partition chromatography solvent systems for natural product purifications has been studied and the solvent systems classified in a comprehensive database. Papers were studied from the earliest found examples containing natural product separations in 1984 until the end of 2014. In total, 2594 solvent systems have been classified, of which 272 are gradient systems. To observe any trends or patterns in the data, the natural product solutes were divided into 21 classes and the solvent systems into 7 different types. The complete database, sorted according to natural product class, is available for download to assist separation scientists in future liquid-liquid chromatography purifications. PMID:26219437

  8. Solvent-resistant microporous polymide membranes

    DOEpatents

    Miller, W.K.; McCray, S.B.; Friesen, D.T.

    1998-03-10

    An asymmetric microporous membrane with exceptional solvent resistance and highly desirable permeability is disclosed. The membrane is made by a solution-casting or solution-spinning process from a copolyamic acid comprising the condensation reaction product in a solvent of at least three reactants selected from certain diamines and dianhydrides and post-treated to imidize and in some cases cross-link the copolyamic acid. The membrane is useful as an uncoated membrane for ultrafiltration, microfiltration, and membrane contactor applications, or may be used as a support for a permselective coating to form a composite membrane useful in gas separations, reverse osmosis, nanofiltration, pervaporation, or vapor permeation.

  9. Solvent-resistant microporous polymide membranes

    DOEpatents

    Miller, Warren K.; McCray, Scott B.; Friesen, Dwayne T.

    1998-01-01

    An asymmetric microporous membrane with exceptional solvent resistance and highly desirable permeability is disclosed. The membrane is made by a solution-casting or solution-spinning process from a copolyamic acid comprising the condensation reaction product in a solvent of at least three reactants selected from certain diamines and dianhydrides and post-treated to imidize and in some cases cross-link the copolyamic acid. The membrane is useful as an uncoated membrane for ultrafiltration, microfiltration, and membrane contactor applications, or may be used as a support for a permselective coating to form a composite membrane useful in gas separations, reverse osmosis, nanofiltration, pervaporation, or vapor permeation.

  10. Copper leaching, solvent extraction, and electrowinning technology

    SciTech Connect

    Jergensen, G.V. II

    1999-07-01

    This volume recognizes the growing role of solvent extraction and electrowinning technology in the global copper business. This process is an efficient and cost effective way to extract copper. This proceedings documents the present status of the SX-EW business. It represents a substantial body of historical, scientific, engineering, and commercial information regarding the growth and application of the technology. Sections include: the business and technology of SX-EW, theory and practice of copper leaching, theory and practice of tankhouse operations, and theory and practice of solvent extraction.

  11. Lysozyme gelation in mixtures of tetramethylurea with protic solvents: Use of solvatochromic indicators to probe medium microstructure and solute solvent interactions

    NASA Astrophysics Data System (ADS)

    da Silva, Marcelo A.; El Seoud, Omar A.; Arêas, Elizabeth P. G.

    2007-09-01

    This work investigated the relationship between the structure of binary mixtures of tetramethylurea and protic solvents and their capacity to induce lysozyme gelation. In order to get an insight into the mechanism of gel formation, the solvatochromic behavior of zwitterionic probes, employed as simple models for the protein, was investigated. We studied two probes of similar p Ka's, but different hydrophobic character, namely 2,6-diphenyl-4-(2,4,6-triphenylpyridinium-1-yl) phenolate, RB, and 4-[2-(1-methylpyridinium-4-yl) ethenyl] phenolate, MC. The protic solvents used included water, 1-propanol and 2- n-butoxyethanol in the temperature range from 10 to 60 °C, and methanol, from 10 to 40 °C. In all cases, the dependence of the empirical solvent polarity parameter, ET, on mixture composition was non-ideal with negative deviation for TMU-water and positive deviation for TMU-organic solvent. For all binary mixtures, the deviation from linearity decreased as a function of increasing the temperature. In TMU/alcohol, the effect became more pronounced with increasing alcohol hydrophobicity.

  12. A multi-step solvent-free mechanochemical route to indium(iii) complexes.

    PubMed

    Wang, Jingyi; Ganguly, Rakesh; Yongxin, Li; Díaz, Jesus; Soo, Han Sen; García, Felipe

    2016-05-10

    Mechanochemistry is well-established in the solid-phase synthesis of inorganic materials but has rarely been employed for molecular syntheses. In recent years, there has been nascent interest in 'greener' synthetic methods with less solvent, higher yields, and shorter reaction times being especially appealing to the fine chemicals and inorganic catalyst industries. Herein, we demonstrate that main-group indium(iii) complexes featuring bis(imino)acenaphthene (BIAN) ligands are readily accessible through a mechanochemical milling approach. The synthetic methodology reported herein not only bypasses the use of large solvent quantities and transition metal reagents for ligand synthesis, but also reduces reaction times dramatically. These new main-group complexes exhibit the potential to be reduced to indium(i) compounds, which may be employed as photosensitizers in organic catalyses and functional materials. PMID:27112317

  13. Next Generation Solvent Performance in the Modular Caustic Side Solvent Extraction Process - 15495

    SciTech Connect

    Smith, Tara E.; Scherman, Carl; Martin, David; Suggs, Patricia

    2015-01-14

    Changes to the Modular Caustic Side Solvent Extraction Unit (MCU) flow-sheet were implemented in the facility. Implementation included changing the scrub and strip chemicals and concentrations, modifying the O/A ratios for the strip, scrub, and extraction contactor banks, and blending the current BoBCalixC6 extractant-based solvent in MCU with clean MaxCalix extractant-based solvent. During the successful demonstration period, the MCU process was subject to rigorous oversight to ensure hydraulic stability and chemical/radionuclide analysis of the key process tanks (caustic wash tank, solvent hold tank, strip effluent hold tank, and decontaminated salt solution hold tank) to evaluate solvent carryover to downstream facilities and the effectiveness of cesium removal from the liquid salt waste. Results indicated the extraction of cesium was significantly more effective with an average Decontamination Factor (DF) of 1,129 (range was 107 to 1,824) and that stripping was effective. The contactor hydraulic performance was stable and satisfactory, as indicated by contactor vibration, contactor rotational speed, and flow stability; all of which remained at or near target values. Furthermore, the Solvent Hold Tank (SHT) level and specific gravity was as expected, indicating that solvent integrity and organic hydraulic stability were maintained. The coalescer performances were in the range of processing results under the BOBCalixC6 flow sheet, indicating negligible adverse impact of NGS deployment. After the Demonstration period, MCU began processing via routine operations. Results to date reiterate the enhanced cesium extraction and stripping capability of the Next Generation Solvent (NGS) flow sheet. This paper presents process performance results of the NGS Demonstration and continued operations of MCU utilizing the blended BobCalixC6-MaxCalix solvent under the NGS flowsheet.

  14. Crystal growth in fused solvent systems

    NASA Technical Reports Server (NTRS)

    Ulrich, D. R.; Noone, M. J.; Spear, K. E.; White, W. B.; Henry, E. C.

    1973-01-01

    Research is reported on the growth of electronic ceramic single crystals from solution for the future growth of crystals in a microgravity environment. Work included growth from fused or glass solvents and aqueous solutions. Topics discussed include: crystal identification and selection; aqueous solution growth of triglycine sulphate (TGS); and characterization of TGS.

  15. EXXON donor solvent coal liquefaction process

    NASA Technical Reports Server (NTRS)

    Epperly, W. R.; Swabb, L. E., Jr.; Tauton, J. W.

    1978-01-01

    A solvent coal liquefaction process to produce low-sulfur liquid products from a wide range of coals is described. An integrated program of laboratory and engineering research and development in conjunction with operation of a 250 T/D pilot plant is discussed.

  16. REPLACING SOLVENT CLEANING WITH AQUEOUS CLEANING

    EPA Science Inventory

    The report documents actions taken by Robert Bosch Corp., Charleston, SC, in replacing the cleaning solvents 1, 1, 2- trichloro-1, 2, 2-trifluoroethane (CFC-113) and trichloroethylene (TCE) with aqueous solutions. Bosch has succeeded in eliminating all their CFC-113 use and so f...

  17. REPLACING SOLVENT CLEANING WITH AQUEOUS CLEANING

    EPA Science Inventory

    The report documents actions taken by Robert Bosch Corp., Charleston, SC, in replacing the cleaning solvents 1, 1, 2- trichloro-1, 2, 2-trifluoroethane (CFC-113) and trichloroethylene (TCE) with aqueous solutions. osch has succeeded in eliminating all their CFC-113 use and so far...

  18. Structure and Solvent Properties of Microemulsions

    ERIC Educational Resources Information Center

    Katz, Civia A.; Calzola, Zachary J.; Mbindyo, Jeremiah K. N.

    2008-01-01

    A microscale laboratory experiment to investigate the formation and utility of microemulsions is described. Microemulsions are technologically important fluids that can reduce the use of toxic organic solvents. In the experiment, students prepare a microemulsion and compare the solubility of sudan III dye in the microemulsion and in dodecane. They…

  19. Deep eutectic solvents: syntheses, properties and applications.

    PubMed

    Zhang, Qinghua; De Oliveira Vigier, Karine; Royer, Sébastien; Jérôme, François

    2012-11-01

    Within the framework of green chemistry, solvents occupy a strategic place. To be qualified as a green medium, these solvents have to meet different criteria such as availability, non-toxicity, biodegradability, recyclability, flammability, and low price among others. Up to now, the number of available green solvents are rather limited. Here we wish to discuss a new family of ionic fluids, so-called Deep Eutectic Solvents (DES), that are now rapidly emerging in the current literature. A DES is a fluid generally composed of two or three cheap and safe components that are capable of self-association, often through hydrogen bond interactions, to form a eutectic mixture with a melting point lower than that of each individual component. DESs are generally liquid at temperatures lower than 100 °C. These DESs exhibit similar physico-chemical properties to the traditionally used ionic liquids, while being much cheaper and environmentally friendlier. Owing to these remarkable advantages, DESs are now of growing interest in many fields of research. In this review, we report the major contributions of DESs in catalysis, organic synthesis, dissolution and extraction processes, electrochemistry and material chemistry. All works discussed in this review aim at demonstrating that DESs not only allow the design of eco-efficient processes but also open a straightforward access to new chemicals and materials. PMID:22806597

  20. Solvent-Free Synthesis of Chalcones

    ERIC Educational Resources Information Center

    Palleros, Daniel R.

    2004-01-01

    The synthesis of twenty different chalcones in the absence of solvent is presented. The results indicated that out of the twenty different chalcones investigated seventeen can be obtained in a matter of minutes by mixing the corresponding benzaldehyde and acetophenone in the presence of solid NaOH in a mortar with pestle.

  1. Solvent treatment of coal for improved liquefaction

    DOEpatents

    Appell, Herbert R.; Narain, Nand K.; Utz, Bruce R.

    1986-05-06

    Increased liquefaction yield is obtained by pretreating a slurry of solid carbonaceous material and a liquid hydrocarbonaceous solvent at a temperature above 200.degree. C. but below 350.degree. C. for a period of 10 minutes to four hours prior to exposure to liquefaction temperatures.

  2. Ferrier reaction in a deep eutectic solvent.

    PubMed

    Rokade, Sunil M; Bhate, Prakash M

    2015-10-13

    A mild and efficient synthesis of 2,3-unsaturated sugar derivatives has been achieved by conducting the Ferrier reaction in a deep eutectic solvent (DES). A wide range of alcohols including primary, secondary, benzylic, and sugar-derived primary alcohols can be used. Advantages include good yields, shorter reaction times and recyclability of DES. PMID:26279523

  3. Employer approaches to preconception care.

    PubMed

    Phillips, Kathryn E; Flood, Georgette

    2008-01-01

    In recent years, the idea of preconception care-education, counseling, and interventions delivered to women before they become pregnant--has gained traction as a critically important health promotion opportunity for women and their families. Employers, as purchasers of health care and as providers of wellness services, have an important role to play in the promotion of preconception care. Large, self-insured employers can craft their medical benefit plans to include evidence-informed preventive health benefits such as preconception care. Employers can also design and implement worksite health promotion programs that address preconception, pregnancy, and postpartum health. And employers of all sizes can educate women and their partners on pregnancy health through tailored communication. This article provides an overview of the business case for preconception care and concrete steps employers can take to support and incent preconception care among their beneficiaries. The article also includes suggestions on ways providers and health professionals support employers in these efforts. PMID:18977153

  4. Gas separation by composite solvent-swollen membranes

    DOEpatents

    Matson, S.L.; Lee, E.K.L.; Friesen, D.T.; Kelly, D.J.

    1989-04-25

    There is disclosed a composite immobilized liquid membrane of a solvent-swollen polymer and a microporous organic or inorganic support, the solvent being at least one highly polar solvent containing at least one nitrogen, oxygen, phosphorus or sulfur atom, and having a boiling point of at least 100 C and a specified solubility parameter. The solvent or solvent mixture is homogeneously distributed through the solvent-swollen polymer from 20% to 95% by weight. The membrane is suitable for acid gas scrubbing and oxygen/nitrogen separation. 3 figs.

  5. Gas separation by composite solvent-swollen membranes

    DOEpatents

    Matson, Stephen L.; Lee, Eric K. L.; Friesen, Dwayne T.; Kelly, Donald J.

    1989-01-01

    There is disclosed a composite immobulized liquid membrane of a solvent-swollen polymer and a microporous organic or inorganic support, the solvent being at least one highly polar solvent containing at least one nitrogen, oxygen, phosphorous or sulfur atom, and having a boiling point of at least 100.degree. C. and a specified solubility parameter. The solvent or solvent mixture is homogeneously distributed through the solvent-swollen polymer from 20% to 95% by weight. The membrane is suitable for acid gas scrubbing and oxygen/nitrogen separation.

  6. Solvent effect on anthranilic acid spectroscopy.

    PubMed

    Abou-Zied, Osama K; Al-Busaidi, Badriya Y; Husband, John

    2014-01-01

    The spectroscopy of anthranilic acid (AA) was examined in neat and binary solvents of varying polarity and hydrogen bonding strength in order to understand the role of water in solvating the polar sites of the molecule. With the exception of water, the Stokes shift of AA in different solvents was found to be linearly correlated with the normalized molar transition energy of solvent polarity (ETN), indicating the major role of the hydrogen bonding effect in solution. Analysis of the absorption and fluorescence spectra reveals that AA exists as an anion in neutral water. The pKa (4.50) and pKa* (4.44) values were estimated from the spectral shift in the absorption and fluorescence spectra measured in different pH solutions. The shortest fluorescence lifetime was measured in cyclohexane and is attributed to intramolecular hydrogen dislocation/transfer in the excited state. The lifetime values in polar solvents point to the dominant effect of the hydrogen-bond donating strength (α value) of the solvent. The number of water molecules solvating the polar region of the neutral form of AA was estimated to be three from the absorbance change in dioxane/buffer (pH 3.5) binary mixtures. The structures of AA:water complexes were calculated from density functional theory using the B3LYP method with a 6-311++G(2d,p) basis set. A stepwise addition of water molecules (1–3) to the polar region of AA leads to a preferential solvation of the COOH group of the molecule in a closed-cyclic geometry. It is worth noting that the spectral shift as a function of pH suggests the suitability of AA as a probe to estimate the local acidity of binding sites in macromolecules in the pH range 3.0–7.0. PMID:24102373

  7. Linking with Employment: Training from the Perspective of Employers.

    ERIC Educational Resources Information Center

    Herschbach, Dennis R.

    Employers need training, want it, and are willing to pay for it providing it is relevant to their requirements, results in improved product quality, and fosters increased productivity. Firm characteristics make a difference not only with regard to the kinds of skills wanted by employers but also with regard to how training can best be delivered.…

  8. Graduates', University Lecturers' and Employers' Perceptions towards Employability Skills

    ERIC Educational Resources Information Center

    Wickramasinghe, Vathsala; Perera, Lasantha

    2010-01-01

    Purpose: The purpose of this study is to explore employability skills that employers, university lecturers and graduates value to bring to the workplace, when graduates are applying for entry-level graduate jobs in the field of computer science in Sri Lanka. Design/methodology/approach: A total of three samples were selected for this exploratory…

  9. Conceptualizing Learning and Employability "Learning and Employability Framework"

    ERIC Educational Resources Information Center

    Sumanasiri, Erabaddage Gishan Tharanga; Yajid, Mohd Shukri Ab; Khatibi, Ali

    2015-01-01

    Extensive studies have been done on employability and the factors that lead to employability. Previous studies have focused on career development programs, internships, work experience programs, soft-skill development programs, and even university admission criteria which can be considered external factors to university student learning…

  10. 20 CFR 404.1003 - Employment.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Employment. 404.1003 Section 404.1003...- ) Employment, Wages, Self-Employment, and Self-Employment Income Employment § 404.1003 Employment. Employment....1010. Section 404.1004 states the general rule on the kinds of work covered as employment....

  11. 20 CFR 404.1003 - Employment.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 2 2011-04-01 2011-04-01 false Employment. 404.1003 Section 404.1003...- ) Employment, Wages, Self-Employment, and Self-Employment Income Employment § 404.1003 Employment. Employment....1010. Section 404.1004 states the general rule on the kinds of work covered as employment....

  12. 20 CFR 404.1003 - Employment.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 2 2013-04-01 2013-04-01 false Employment. 404.1003 Section 404.1003...- ) Employment, Wages, Self-Employment, and Self-Employment Income Employment § 404.1003 Employment. Employment....1010. Section 404.1004 states the general rule on the kinds of work covered as employment....

  13. 20 CFR 404.1003 - Employment.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 2 2012-04-01 2012-04-01 false Employment. 404.1003 Section 404.1003...- ) Employment, Wages, Self-Employment, and Self-Employment Income Employment § 404.1003 Employment. Employment....1010. Section 404.1004 states the general rule on the kinds of work covered as employment....

  14. Ruthenium-catalyzed alkylation of indoles with tertiary amines by oxidation of a sp3 C-H bond and Lewis acid catalysis.

    PubMed

    Wang, Ming-Zhong; Zhou, Cong-Ying; Wong, Man-Kin; Che, Chi-Ming

    2010-05-17

    Ruthenium porphyrins (particularly [Ru(2,6-Cl(2)tpp)CO]; tpp=tetraphenylporphinato) and RuCl(3) can act as oxidation and/or Lewis acid catalysts for direct C-3 alkylation of indoles, giving the desired products in high yields (up to 82% based on 60-95% substrate conversions). These ruthenium compounds catalyze oxidative coupling reactions of a wide variety of anilines and indoles bearing electron-withdrawing or electron-donating substituents with high regioselectivity when using tBuOOH as an oxidant, resulting in the alkylation of N-arylindoles to 3-{[(N-aryl-N-alkyl)amino]methyl}indoles (yield: up to 82%, conversion: up to 95%) and the alkylation of N-alkyl or N-H indoles to 3-[p-(dialkylamino)benzyl]indoles (yield: up to 73%, conversion: up to 92%). A tentative reaction mechanism involving two pathways is proposed: an iminium ion intermediate may be generated by oxidation of an sp(3) C-H bond of the alkylated aniline by an oxoruthenium species; this iminium ion could then either be trapped by an N-arylindole (pathway A) or converted to formaldehyde, allowing a subsequent three-component coupling reaction of the in situ generated formaldehyde with an N-alkylindole and an aniline in the presence of a Lewis acid catalyst (pathway B). The results of deuterium-labeling experiments are consistent with the alkylation of N-alkylindoles via pathway B. The relative reaction rates of [Ru(2,6-Cl(2)tpp)CO]-catalyzed oxidative coupling reactions of 4-X-substituted N,N-dimethylanilines with N-phenylindole (using tBuOOH as oxidant), determined through competition experiments, correlate linearly with the substituent constants sigma (R(2)=0.989), giving a rho value of -1.09. This rho value and the magnitudes of the intra- and intermolecular deuterium isotope effects (k(H)/k(D)) suggest that electron transfer most likely occurs during the initial stage of the oxidation of 4-X-substituted N,N-dimethylanilines. Ruthenium-catalyzed three-component reaction of N-alkyl/N-H indoles, paraformaldehyde, and anilines gave 3-[p-(dialkylamino)benzyl]indoles in up to 82% yield (conversion: up to 95%). PMID:20391566

  15. Tertiary amine-catalyzed (4 + 2) annulations of δ-acetoxy allenoates: synthesis of multisubstituted 4H-pyran and 4H-chromene.

    PubMed

    Gu, Yiting; Li, Falin; Hu, Pengfei; Liao, Daohua; Tong, Xiaofeng

    2015-03-01

    The DABCO-catalyzed divergent (4 + 2) annulations of δ-acetoxy allenoates 1 are reported. The chemical behavior of 1 under DABCO catalyst was found to be substrate dependent. Allenoate 1 with an aromatic group at δC preferentially reacted with salicylaldehyde derivative 2, delivering 4H-chromenes 3. On the other hand, allenoates 1 with an alkyl group at δC readily underwent (4 + 2) annulations with oxo diene 4 to afford 4H-pyrans 5. PMID:25692476

  16. pH-Regulated surface property and pH-reversible micelle transition of a tertiary amine-based gemini surfactant in aqueous solution.

    PubMed

    Lu, Hongsheng; Xue, Miao; Wang, Baogang; Huang, Zhiyu

    2015-12-21

    A series of tertiary amide-based gemini surfactants, 2,2'-(1,4-phenylenebis(oxy))bis(N-(3-(dimethylamino)propyl)alkylamide), abbreviated as Cm-A-Cm (m = 8; 10; 12; 14), were synthesized. The surface property and aggregation behaviors of the Cm-A-Cm aqueous solutions were studied in detail. The Cm-A-Cm exhibited high and pH-regulated surface activity at the air/water interface; i.e., the critical micelle concentration was 5.6 × 10(-6) mol L(-1) at pH = 2.50 when m = 14 and was further regulated to 1.8 × 10(-6) mol L(-1) by altering the pH to 6.50. When the pH was tuned from 2.0 to 12.0, the appearance of the C12-A-C12 aqueous solution (35 mM) underwent 5 states: transparent water-like solution, viscous fluid, gel-like fluid, turbid liquid and dispersion system with white precipitate. The results of rheology, cryogenic transmission electron microscopy, and dynamic light scattering characterization revealed that the transition from water-like to viscous or gel-like liquid was actually due to aggregate microstructure transition from spherical to worm-like micelles. This transition was completely reversible between pH = 2.50 and 6.81, tuned by adding HCl and NaOH solutions for at least 4 cycles. Similar micellar transitions regulated by pH were also found for m = 8 and 10, whereas only worm-like micelles were formed for m = 14 at both acidic and nearly neutral conditions. Finally, a reasonable mechanism of aggregate behavior transition was proposed from the viewpoint of the molecular states, molecular structures, and the intra- and inter-molecular interactions. PMID:26411356

  17. Studies on tropane alkaloid extraction by volatile organic solvents: dichloromethane vs. chloroform.

    PubMed

    El Jaber-Vazdekis, Nabil; Gutierrez-Nicolas, Fátima; Ravelo, Angel G; Zárate, Rafael

    2006-01-01

    In order to investigate the production of tropane alkaloids by hairy roots of Atropa baetica, transgenic for the gene h6h encoding the enzyme hyoscyamine 6beta-hydroxylase, solvent extraction with chloroform and with dichloromethane of the metabolites present in the liquid medium and in the root tissue was compared. The extraction of scopolamine from the liquid medium was equally effective with either solvent, giving maximum values of around 850 microg/flask. For the roots, three different extraction methods were employed: A, employing chloroform:methanol: (25%) ammonia (15:5:1) for initial extraction, followed by treatment with sulfuric acid and ammonia, and using chloroform for the final extraction and washes; B, as A but using dichloromethane for extraction and washes; and C, as B but substituting chloroform for dichloromethane in the extraction cocktail. Scopolamine was the most abundant metabolite (present in amounts of 3250-3525 microg/g dry weight) and presented similar extraction efficiencies with all of the extraction methods employed. The highest amounts of hyoscyamine and the intermediate 6beta-hydxoxyhyoscyamine were present on day 31 (800 and 975 microg/g dry weight, respectively) and no statistical differences between the three extraction methods employed were detected. This study confirms that, for the extraction of tropane alkaloids, dichloromethane can replace the commonly employed chloroform, the use of which incurs major health, security and regulation problems. PMID:16634287

  18. Effectiveness of three solvents and two associations of solvents on gutta-percha and resilon.

    PubMed

    Faria-Júnior, Norberto Batista de; Loiola, Livia Etchebehere de; Guerreiro-Tanomaru, Juliane Maria; Berbert, Fábio Luis Camargo Villela; Tanomaru-Filho, Mário

    2011-01-01

    This study evaluated the effectiveness of 3 solvents (Citrol orange oil, Eucalyptol and Tetrachloroethylene) and 2 associations of solvents (Citrol orange oil+Tetrachloroethylene and Eucalyptol+Tetrachloroethylene) on 3 types of gutta-percha (conventional, thermoplastic and EndoREZ) and Resilon. Ten discs (10 mm diameter x 1 mm thick) from each material were prepared using standard metallic molds. Each specimen was weighed to determinate its initial mass. The specimens were immersed in the solvents for 10 min, followed by immersion in distilled water for 20 min, and were then reweighed to obtain the final mass. The mean weight loss determined the solvent capacity. Data were analyzed by ANOVA and Tukey's test at 5% significance level. Tetrachloroethylene was the most effective on conventional gutta-percha (p<0.05). Tetrachloroethylene was also the most effective on thermoplastic gutta-percha, but it was not significantly different (p>0.05) from Eucalyptol+Tetrachloroethylene, Citrol+Tetrachloroethylene, and Citrol. All solvents and associations presented little effectiveness on Resilon. The association Eucalyptol+Tetrachloroethylene was the most effective on EndoREZ, but it did not differ significantly (p>0.05) from Citrol+Tetrachloroethylene and Tetrachloroethylene. All evaluated substances presented solvent action. Tetrachloroethylene improved the effectiveness of both Citrol and Eucalyptol. PMID:21519647

  19. Solvent Effects on the Formation of Surface Nanodroplets by Solvent Exchange.

    PubMed

    Lu, Ziyang; Xu, Haolan; Zeng, Hongbo; Zhang, Xuehua

    2015-11-10

    Solvent exchange is a simple process to form oil nanodroplets at solid-liquid interfaces with well-defined location and morphology. In this process, a good solvent of the oil is displaced by a poor solvent, leading to the nucleation and growth of oil droplets from a transient oversaturation at the mixing front. Our recent work has shown that the final volume of the droplets is related to the flow conditions. In this work, we investigate the effects of the type and the composition of solvents on the droplet formation under the same flow conditions. Water nanodroplets were produced by ethanol/cyclohexane (solution A) and cyclohexane (solution B) on a hydrophilic substrate. We found that the droplet size increases first and then decreases with an increase of the initial ethanol concentration in solution A. This is attributed to the phase separation of ethanol-cyclohexane-water; in particular, the composition of solution A on the phase boundary above the Ouzo region. The same reason also contributes to the lower efficiency in droplet formation for a longer alkane. The important implication from this work is that the maximal droplet volume is limited by the phase separation of the solvents used in the solvent exchange. PMID:26488386

  20. Effect of solvent volume on the physical properties of aluminium doped nanocrystalline zinc oxide thin films deposited using a simplified spray pyrolysis technique

    NASA Astrophysics Data System (ADS)

    Jabena Begum, N.; Mohan, R.; Ravichandran, K.

    2013-01-01

    Aluminium doped zinc oxide (AZO) thin films were deposited by employing a low cost and simplified spray technique using a perfume atomizer from starting solutions having different volumes (10, 20, … , 50 mL) of solvent. The effect of solvent volume on the structural, electrical, optical, photoluminescence (PL) and surface morphological properties was studied. The electrical resistivity of the AZO films is remarkably influenced by the variation in the solvent volume. The X-ray diffraction profiles clearly showed that all the films have preferential orientation along the (0 0 2) plane irrespective of the solvent volume. The crystallite size was found to be in the nano range of 35-46 nm. The optical transmittance in the visible region is desirably high (>85%). The AFM images show columnar morphology with varying grain size. The PL studies revealed that the AZO film deposited from 50 mL of solvent volume has good quality with lesser defect density.