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Sample records for alkaline conditions results

  1. Microbial Thiocyanate Utilization under Highly Alkaline Conditions

    PubMed Central

    Sorokin, Dimitry Y.; Tourova, Tatyana P.; Lysenko, Anatoly M.; Kuenen, J. Gijs

    2001-01-01

    activity which converted cyanate (CNO−) to ammonia and CO2. On the other hand, cyanase activity either was absent or was present at very low levels in the autotrophic strains grown on thiocyanate as the sole energy and N source. As a result, large amounts of cyanate were found to accumulate in the media during utilization of thiocyanate at pH 10 in batch and thiocyanate-limited continuous cultures. This is a first direct proof of a “cyanate pathway” in pure cultures of thiocyanate-degrading bacteria. Since it is relatively stable under alkaline conditions, cyanate is likely to play a role as an N buffer that keeps the alkaliphilic bacteria safe from inhibition by free ammonia, which otherwise would reach toxic levels during dissimilatory degradation of thiocyanate. PMID:11157213

  2. Acylglucuronide in alkaline conditions: migration vs. hydrolysis.

    PubMed

    Di Meo, Florent; Steel, Michele; Nicolas, Picard; Marquet, Pierre; Duroux, Jean-Luc; Trouillas, Patrick

    2013-06-01

    This work rationalizes the glucuronidation process (one of the reactions of the phase II metabolism) for drugs having a carboxylic acid moiety. At this stage, acylglucuronides (AG) metabolites are produced, that have largely been reported in the literature for various drugs (e.g., mycophenolic acid (MPA), diclofenac, ibuprofen, phenylacetic acids). The competition between migration and hydrolysis is rationalized by adequate quantum calculations, combing MP2 and density functional theory (DFT) methods. At the molecular scale, the former process is a real rotation of the drug around the glucuconic acid. This chemical-engine provides four different metabolites with various toxicities. Migration definitely appears feasible under alkaline conditions, making proton release from the OH groups. The latter reaction (hydrolysis) releases the free drug, so the competition is of crucial importance to tackle drug action and elimination. From the theoretical data, both migration and hydrolysis appear kinetically and thermodynamically favored, respectively.

  3. Increased performance of hydrogen production in microbial electrolysis cells under alkaline conditions.

    PubMed

    Rago, Laura; Baeza, Juan A; Guisasola, Albert

    2016-06-01

    This work reports the first successful enrichment and operation of alkaline bioelectrochemical systems (microbial fuel cells, MFC, and microbial electrolysis cells, MEC). Alkaline (pH=9.3) bioelectrochemical hydrogen production presented better performance (+117%) compared to conventional neutral conditions (2.6 vs 1.2 litres of hydrogen gas per litre of reactor per day, LH2·L(-1)REACTOR·d(-1)). Pyrosequencing results of the anodic biofilm showed that while Geobacter was mainly detected under conventional neutral conditions, Geoalkalibacter sp. was highly detected in the alkaline MFC (21%) and MEC (48%). This is the first report of a high enrichment of Geoalkalibacter from an anaerobic mixed culture using alkaline conditions in an MEC. Moreover, Alkalibacter sp. was highly present in the anodic biofilm of the alkaline MFC (37%), which would indicate its potentiality as a new exoelectrogen.

  4. Alkaline nanoparticle coatings improve resin bonding of 10-methacryloyloxydecyldihydrogenphosphate-conditioned zirconia.

    PubMed

    Qian, Mengke; Lu, Zhicen; Chen, Chen; Zhang, Huaiqin; Xie, Haifeng

    Creating an alkaline environment prior to 10-methacryloyloxydecyldihydrogenphosphate (MDP) conditioning improves the resin bonding of zirconia. The present study evaluated the effects of four alkaline coatings with different water solubilities and pH values on resin bonding of MDP-conditioned zirconia. Two alkaline nanoparticle coatings were studied in particular. Thermodynamics calculations were performed to evaluate the strengths of MDP-tetragonal phase zirconia chemical bonds at different pH values. Zirconia surfaces with and without alkaline coatings were characterized by scanning electron microscope (SEM)/energy dispersive spectrometer and Fourier transform infrared spectroscopy; alkaline coatings included NaOH, Ca(OH)2, nano-MgO, and nano-Zr(OH)4. A shear bond strength (SBS) test was performed to evaluate the effects of the four alkaline coatings on bonding; the alkaline coatings were applied to the surfaces prior to conditioning the zirconia with MDP-containing primers. Gibbs free energies of the MDP-tetragonal zirconia crystal model coordination reaction in different pH environments were -583.892 (NaOH), -569.048 [Ca(OH)2], -547.393 (MgO), and -530.279 kJ/mol [Zr(OH)4]. Thermodynamic calculations indicated that the alkaline coatings improved bonding in the following order: NaOH > Ca(OH)2 > MgO > Zr(OH)4. Statistical analysis of SBS tests showed a different result. SBSs were significantly different in groups that had different alkaline coatings, but it was not influenced by different primers. All four alkaline coatings increased SBS compared to control groups. Of the four coatings, nano-Zr(OH)4 and -MgO showed higher SBS. Therefore, preparing nano-Zr(OH)4 or -MgO coatings prior to conditioning with MDP-containing primers may potentially improve resin bonding of zirconia in the clinic.

  5. Alkaline nanoparticle coatings improve resin bonding of 10-methacryloyloxydecyldihydrogenphosphate-conditioned zirconia

    PubMed Central

    Qian, Mengke; Lu, Zhicen; Chen, Chen; Zhang, Huaiqin; Xie, Haifeng

    2016-01-01

    Creating an alkaline environment prior to 10-methacryloyloxydecyldihydrogenphosphate (MDP) conditioning improves the resin bonding of zirconia. The present study evaluated the effects of four alkaline coatings with different water solubilities and pH values on resin bonding of MDP-conditioned zirconia. Two alkaline nanoparticle coatings were studied in particular. Thermodynamics calculations were performed to evaluate the strengths of MDP-tetragonal phase zirconia chemical bonds at different pH values. Zirconia surfaces with and without alkaline coatings were characterized by scanning electron microscope (SEM)/energy dispersive spectrometer and Fourier transform infrared spectroscopy; alkaline coatings included NaOH, Ca(OH)2, nano-MgO, and nano-Zr(OH)4. A shear bond strength (SBS) test was performed to evaluate the effects of the four alkaline coatings on bonding; the alkaline coatings were applied to the surfaces prior to conditioning the zirconia with MDP-containing primers. Gibbs free energies of the MDP-tetragonal zirconia crystal model coordination reaction in different pH environments were −583.892 (NaOH), −569.048 [Ca(OH)2], −547.393 (MgO), and −530.279 kJ/mol [Zr(OH)4]. Thermodynamic calculations indicated that the alkaline coatings improved bonding in the following order: NaOH > Ca(OH)2 > MgO > Zr(OH)4. Statistical analysis of SBS tests showed a different result. SBSs were significantly different in groups that had different alkaline coatings, but it was not influenced by different primers. All four alkaline coatings increased SBS compared to control groups. Of the four coatings, nano-Zr(OH)4 and -MgO showed higher SBS. Therefore, preparing nano-Zr(OH)4 or -MgO coatings prior to conditioning with MDP-containing primers may potentially improve resin bonding of zirconia in the clinic. PMID:27785013

  6. Properties of whey protein isolates extruded under acidic and alkaline conditions.

    PubMed

    Onwulata, C I; Isobe, S; Tomasula, P M; Cooke, P H

    2006-01-01

    Whey proteins have wide acceptance and use in many products due to their beneficial nutritional properties. To further increase the amount of whey protein isolates (WPI) that may be added to products such as extruded snacks and meats, texturization of WPI is necessary. Texturization changes the folding of globular proteins to improve interaction with other ingredients and create new functional ingredients. In this study, WPI pastes (60% solids) were extruded in a twin-screw extruder at 100 degrees C with 4 pH-adjusted water streams: acidic (pH 2.0 +/- 0.2) and alkaline (pH 12.4 +/- 0.4) streams from 2 N HCl and 2 N NaOH, respectively, and acidic (pH 2.5 +/- 0.2) and alkaline (pH 11.5 +/- 0.4) electrolyzed water streams; these were compared with WPI extruded with deionized water. The effects of water acidity on WPI solubility at pH 7, color, microstructure, Rapid Visco Analyzer pasting properties, and physical structure were determined. Alkaline conditions increased insolubility caused yellowing and increased pasting properties significantly. Acidic conditions increased solubility and decreased WPI pasting properties. Subtle structural changes occurred under acidic conditions, but were more pronounced under alkaline conditions. Overall, alkaline conditions increased denaturation in the extruded WPI resulting in stringy texturized WPI products, which could be used in meat applications.

  7. Investigation on phase transformation mechanism of zeolite NaY under alkaline hydrothermal conditions

    SciTech Connect

    Li, Peng Ding, Tian Liu, Liping Xiong, Guang

    2013-12-15

    The phase transformation mechanism of zeolite NaY under alkaline hydrothermal conditions was investigated by UV Raman spectroscopy, X-ray diffraction, X-ray fluorescence and scanning electron microscopy techniques. The results revealed that the products and transformation rate are dependent on the alkalinities. All of the starting and resulting zeolites are constructed with the 4-ring and 6-ring secondary building units. The products have lower Si/Al ratio, higher framework density and smaller pore size, which are more stable under alkaline hydrothermal condition. During the phase transformation the fragments of faujasite are formed, then the fragments combine to form different zeolites depending on basicity. Zeolite NaY crystals are consumed as the reservoir for the transformation products during the recrystallization process. For the first time, a 4-membered ring intermediate was found at the early stage of the recrystallization process. A cooperative interaction of liquid and solid phases is required for inducing the phase transformation. - Graphical Abstract: Phase transformation of NaY zeolite under alkaline hydrothermal condition is achieved by the cooperative interaction of the liquid and solid phases. A 4-membered ring species is an intermediate for recrystallization process. Highlights: • The products and transformation rate are dependent on the alkalinity. • A 4-membered ring species is an intermediate for recrystallization process. • A cooperative interaction of liquid and solid phases is required.

  8. Prebiotic Synthesis of Protobiopolymers Under Alkaline Ocean Conditions

    NASA Astrophysics Data System (ADS)

    Ruiz-Bermejo, Marta; Rivas, Luis A.; Palacín, Arantxa; Menor-Salván, César; Osuna-Esteban, Susana

    2011-08-01

    Clasically, prebiotic chemistry has focused on the production and identification of simple organic molecules, many of them forming part of "intractable polymers" named tholins. In a previous work, we demonstrated that in experiments using an external energy source and inorganic carbon the aqueous aerosols improved the formation of hydrophilic tholins. Herein, we elucidate the role of pH (from 4 to 12) in prebiotic experiments using saline aqueous aerosols, spark discharges and an atmosphere containing CH4. At all values of pH, the saline aqueous aerosols increased the production of a significant variety of carboxylic acids that could have been present in a primitive Krebs cycle. Moreover, the study for the first time of hydrophilic tholins by 2-D electrophoresis revealed that these are formed by a set of unexpected heavy polymeric species. The initial alkaline conditions significantly increased both the apparent molecular weight of polymeric species up to 80 kDa and their diversity. We propose the term of protobiopolymers to denote those polymeric species fractionated by 2-D electrophoresis since these are formed by biomolecules present in living systems and show diversity in length as well as in functional groups. Thus, aerosols formed in simulated alkaline ocean conditions could provide an optimal medium for the formation of the primeval materials that could be precursors to the emergence of life.

  9. Alternative Alkaline Conditioning of Amidoxime Based Adsorbent for Uranium Extraction from Seawater

    SciTech Connect

    Das, S.; Liao, W. -P.; Flicker Byers, M.; Tsouris, C.; Janke, C. J.; Mayes, R. T.; Schneider, E.; Kuo, L. -J.; Wood, J. R.; Gill, G. A.; Dai, S.

    2016-04-20

    Alkaline conditioning of the amidoxime based adsorbents is a significant step in the preparation of the adsorbent for uranium uptake from seawater. The effects of various alkaline conditioning parameters such as the type of alkaline reagent, reaction temperature, and reaction time were investigated with respect to uranium adsorption capacity from simulated seawater (spiked with 8 ppm uranium) and natural seawater (from Sequim Bay, WA). An adsorbent (AF1) was prepared at the Oak Ridge National Laboratory by radiation-induced graft polymerization (RIGP) with acrylonitrile and itaconic acid onto high-surface-area polyethylene fibers. For the AF1 adsorbent, sodium hydroxide emerged as a better reagent for alkaline conditioning over potassium hydroxide, which has typically been used in previous studies, because of higher uranium uptake capacity and lower cost over the other candidate alkaline reagents investigated in this study. Use of sodium hydroxide in place of potassium hydroxide is shown to result in a 21-30% decrease in the cost of uranium recovery.

  10. Alternative alkaline conditioning of amidoxime based adsorbent for uranium extraction from seawater

    DOE PAGES

    Das, Sadananda; Liao, Wei -Po; Byers, Maggie Flicker; ...

    2015-10-18

    Alkaline conditioning of the amidoxime based adsorbents is a significant step in the preparation of the adsorbent for uranium uptake from seawater. The effects of various alkaline conditioning parameters such as the type of alkaline reagent, reaction temperature, and reaction time were investigated with respect to uranium adsorption capacity from simulated seawater (spiked with 8 ppm uranium) and natural seawater (from Sequim Bay, WA). An adsorbent (AF1) was prepared at the Oak Ridge National Laboratory by radiation-induced graft polymerization (RIGP) with acrylonitrile and itaconic acid onto high-surface-area polyethylene fibers. For the AF1 adsorbent, sodium hydroxide emerged as a better reagentmore » for alkaline conditioning over potassium hydroxide, which has typically been used in previous studies, because of higher uranium uptake capacity and lower cost over the other candidate alkaline reagents investigated in this study. Furthermore, the use of sodium hydroxide in place of potassium hydroxide is shown to result in a 21–30% decrease in the cost of uranium recovery.« less

  11. Alternative alkaline conditioning of amidoxime based adsorbent for uranium extraction from seawater

    SciTech Connect

    Das, Sadananda; Liao, Wei -Po; Byers, Maggie Flicker; Tsouris, Costas; Janke, Christopher James; Mayes, Richard T.; Schneider, Eric; Kuo, Li -Jung; Wood, Jordana R.; Gill, Gary A.; Dai, Sheng

    2015-10-18

    Alkaline conditioning of the amidoxime based adsorbents is a significant step in the preparation of the adsorbent for uranium uptake from seawater. The effects of various alkaline conditioning parameters such as the type of alkaline reagent, reaction temperature, and reaction time were investigated with respect to uranium adsorption capacity from simulated seawater (spiked with 8 ppm uranium) and natural seawater (from Sequim Bay, WA). An adsorbent (AF1) was prepared at the Oak Ridge National Laboratory by radiation-induced graft polymerization (RIGP) with acrylonitrile and itaconic acid onto high-surface-area polyethylene fibers. For the AF1 adsorbent, sodium hydroxide emerged as a better reagent for alkaline conditioning over potassium hydroxide, which has typically been used in previous studies, because of higher uranium uptake capacity and lower cost over the other candidate alkaline reagents investigated in this study. Furthermore, the use of sodium hydroxide in place of potassium hydroxide is shown to result in a 21–30% decrease in the cost of uranium recovery.

  12. Change of pH during excess sludge fermentation under alkaline, acidic and neutral conditions.

    PubMed

    Yuan, Yue; Peng, Yongzhen; Liu, Ye; Jin, Baodan; Wang, Bo; Wang, Shuying

    2014-12-01

    The change in pH during excess sludge (ES) fermentation of varying sludge concentrations was investigated in a series of reactors at alkaline, acidic, and neutral pHs. The results showed that the changes were significantly affected by fermentative conditions. Under different conditions, pH exhibited changing profiles. When ES was fermented under alkaline conditions, pH decreased in a range of (10±1). At the beginning of alkaline fermentation, pH dropped significantly, at intervals of 4h, 4h, and 5h with sludge concentrations of 8665.6mg/L, 6498.8mg/L, and 4332.5mg/L, then it would become moderate. However, under acidic conditions, pH increased from 4 to 5. Finally, under neutral conditions pH exhibited a decrease then an increase throughout entire fermentation process. Further study showed short-chain fatty acids (SCFAs), ammonia nitrogen and cations contributed to pH change under various fermentation conditions. This study presents a novel strategy based on pH change to predict whether SCFAs reach their stable stage.

  13. Solvothermal Synthesis and Formation Mechanism of Potassium Sodium Niobate Mesocrystals Under Low Alkaline Conditions.

    PubMed

    Gu, QiLin; Zhu, Kongjun; Liu, Jinsong; Wang, Jing; Qiu, Jinhao; Cao, Yang; Liu, Pengcheng; Yao, Linlin

    2015-07-01

    Pure-phase (K, Na)NbO3 (KNN) powders with orthorhombic symmetry were successfully synthesized by solvothermal method using isopropanol as solvent, without the addition of water. The as-prepared powders were characterized by X-ray diffraction, scanning electron microscopy and energy dispersive spectrometry to show the variation of phase, morphology, size distribution and chemical composition under different synthetic conditions, such as fill factors (FF) of the solvothermal system and alkalinity of the starting solution. Compared with the traditional hydrothermal method and the so-called solvothermal method (water aided in fact), small grains with well crystallinity were obtained using 100% isopropanol as reaction medium. The results indicate that both fill factor and alkalinity have significant effects on the phase structure and size distribution of the as-obtained KNN powders. Pure orthorhombic perovskite-structured KNN powders with a grain size of 100 nm were synthesized at the following condition: reaction time, 16 h; reaction temperature, 240 °C; fill factor, 70%; and alkalinity, 1 M. Small grains (~100 nm) tend to form mesocrystals (~10 µm) with tetrakaidecahedron structures, and the possible formation mechanism was proposed. The solvothermal method without the addition of water is a promising alternative to synthesize pure and refined powders under mild reaction conditions.

  14. The catalytic properties of alkaline phosphatases under various conditions

    NASA Astrophysics Data System (ADS)

    Atyaksheva, L. F.; Chukhrai, E. S.; Poltorak, O. M.

    2008-11-01

    A comparative study was performed to examine the catalytic properties of alkaline phosphatases from bacteria Escherichia coli and bovine and chicken intestines. The activity of enzyme dimers and tetramers was determined. The activity of the dimer was three or four times higher than that of the tetramer. The maximum activity and affinity for 4-nitrophenylphosphate was observed for the bacterial alkaline phosphatase ( K M = 1.7 × 10-5 M, V max = 1800 μmol/(min mg of protein) for dimers and V max = 420 μmol/(min mg of protein) for tetramers). The Michaelis constants were equal for two animal phosphatases in various buffer media (pH 8.5) ((3.5 ± 0.2) × 10-4 M). Five buffer systems were investigated: tris, carbonate, hepes, borate, and glycine buffers, and the lowest catalytic activity of alkaline phosphatases at equal pH was observed in the borate buffer (for enzyme from bovine intestine, V max = 80 μmol/(min mg of protein)). Cu2+ cations formed a complex with tris-(oxymethyl)-aminomethane ( tris-HCl buffer) and inhibited the intestine alkaline phosphatases by a noncompetitive mechanism.

  15. Exposure to the proton scavenger glycine under alkaline conditions induces Escherichia coli viability loss.

    PubMed

    Vanhauteghem, Donna; Janssens, Geert Paul Jules; Lauwaerts, Angelo; Sys, Stanislas; Boyen, Filip; Cox, Eric; Meyer, Evelyne

    2013-01-01

    Our previous work described a clear loss of Escherichia coli (E. coli) membrane integrity after incubation with glycine or its N-methylated derivatives N-methylglycine (sarcosine) and N,N-dimethylglycine (DMG), but not N,N,N-trimethylglycine (betaine), under alkaline stress conditions. The current study offers a thorough viability analysis, based on a combination of real-time physiological techniques, of E. coli exposed to glycine and its N-methylated derivatives at alkaline pH. Flow cytometry was applied to assess various physiological parameters such as membrane permeability, esterase activity, respiratory activity and membrane potential. ATP and inorganic phosphate concentrations were also determined. Membrane damage was confirmed through the measurement of nucleic acid leakage. Results further showed no loss of esterase or respiratory activity, while an instant and significant decrease in the ATP concentration occurred upon exposure to either glycine, sarcosine or DMG, but not betaine. There was a clear membrane hyperpolarization as well as a significant increase in cellular inorganic phosphate concentration. Based on these results, we suggest that the inability to sustain an adequate level of ATP combined with a decrease in membrane functionality leads to the loss of bacterial viability when exposed to the proton scavengers glycine, sarcosine and DMG at alkaline pH.

  16. Differences in the chemical composition of Enterococcus faecalis biofilm under conditions of starvation and alkalinity.

    PubMed

    Chen, Weixu; Liang, Jingping; He, Zhiyan; Jiang, Wei

    2017-01-02

    ABSTACT This study aimed to investigate the dynamic changes that occur in the chemical composition of an Enterococcus faecalis (E. faecalis) biofilm under conditions of starvation and in an alkaline environment and to explore the function of chemical composition changes in the resistance of the E. faecalis biofilm to an extreme environment. This study established an in vitro E. faecalis biofilm model under starvation and in an alkaline environment. During the formation of the biofilm, the pH value and nutritional condition of the culture medium were changed, and the changes in chemical composition were observed using biochemical measures. The results showed that, when the pH value of the culture medium was 11, the percentage of water-insoluble polysaccharides in the biofilm was significantly lower than under other conditions. In addition, the percentage of water-soluble polysaccharides in culture medium with pH values of 9 and 11 gradually decreased. The level of the water-soluble polysaccharides in each milligram of dry weight of biofilm at pH 11 increased compared to that under other conditions. The results from this study indicate that the chemical composition of E. faecalis biofilm changed in extreme environments. These changes served as a defensive mechanism for E. faecalis against environmental pressures.

  17. Effect of hydrothermal reaction time and alkaline conditions on the electrochemical properties of reduced graphene oxide

    NASA Astrophysics Data System (ADS)

    Vermisoglou, E. C.; Giannakopoulou, T.; Romanos, G.; Giannouri, M.; Boukos, N.; Lei, C.; Lekakou, C.; Trapalis, C.

    2015-12-01

    Reduced graphene oxide sheets (rGO) were prepared by hydrothermal treatment of aqueous dispersions of graphite oxide (GtO) applied for short (4 h) and prolonged reaction times (19-24 h). The effect of process duration as well as the alkaline conditions (pH ∼10) by addition of K2CO3 on the quality characteristics of the produced rGO materials was investigated. Both reduction and exfoliation occurred during this process as it was evidenced by FTIR and XRD data. SEM, TEM and HRTEM microscopy displayed highly exfoliated rGO materials. XPS verified that the re-establishment of the conjugated graphene network is more extensive for prolonged times of hydrothermal processing in accordance to Raman spectroscopy measurements. The sample produced under alkaline conditions bore fewer defects and almost 5 times higher BET surface area (∼181 m2/g) than the sample with no pH adjustment (∼34 m2/g) for the same hydrothermal reaction time (19 h), attributed to the developed microporosity. The specific capacitance of this material estimated by electrochemical impedance using three-electrode cell and KCl aqueous solution as an electrolyte was ∼400-500 F/g. When EDLC capacitors were fabricated from rGO materials the electrochemical testing in organic electrolyte i.e. TEABF4 in PC, revealed that the shortest hydrothermal reaction time (4 h) was more efficient resulting in capacitance around 60 F/g.

  18. EFFECT OF CATIONS ON ALUMINUM SPECIATION UNDER ALKALINE CONDITIONS

    SciTech Connect

    Taylor-Pashow, K.; Hobbs, D.

    2012-07-31

    A series of experiments were performed to examine the effect of metal cations common to high level waste on the phase of aluminum formed. Experiments were performed at temperature of 150 C, 75 C, and room temperature, either without additional metal cation, or with 0.01-0.2 molar equivalents of either Ni{sup 2+}, Fe{sup 3+}, Mn{sup 2+}, or Cr{sup 3+}. Results showed that temperature has the greatest effect on the phase obtained. At 150 C, boehmite is the only phase obtained, independent of the presence of other metal cations, with only one exception where a small amount of gibbsite was also detected in the product when 0.2 equivalents of Ni{sup 2+} was present. At 75 C, a mixture of phases is obtained, most commonly including bayerite and gibbsite; however, boehmite is also formed under some conditions, including in the absence of additional metal ion. At room temperature, in the absence of additional metal ion, a mixture of bayerite and gibbsite is obtained. The addition of another metal cation suppresses the formation of gibbsite, with a couple of exceptions (0.2 equivalents of Ni{sup 2+} or 0.01 equivalents of Cr{sup 3+}) where both phases are still obtained.

  19. M4FT-15OR03100421: Status Report on Alkaline Conditioning Studies

    SciTech Connect

    Tsouris, Costas; Brown, Suree; Janke, Christopher James; Mayes, Richard T.; Dai, Sheng; Kuo, Li-Jung; Gill, Gary

    2015-05-01

    Significant progress in understanding the role of alkaline conditioning of polyethylene-fiber adsorbent, developed at the Oak Ridge National Laboratory (ORNL), is demonstrated in this report, which is essentially a manuscript prepared for publication in the journal Industrial & Engineering Chemistry Research of the American Chemical Society. The manuscript describes the influence of various parameters involved in adsorbent alkaline conditioning, including base concentration and duration and temperature of conditioning, on the uranium uptake history by the adsorbent. Various solutions have been used to determine the influence of conditioning parameters including (i) a screening solution containing uranyl nitrate at approximately 8 ppm and sodium bicarbonate and sodium chloride at concentrations similar to those found in seawater, (ii) seawater spiked with approximately 75 ppb uranium, and (iii) natural seawater. In addition to concentration measurements by inductively coupled plasma (ICP) spectroscopy to determine the uranium uptake capacity and kinetics, spectroscopic methods such as Fourier transformed infrared (FTIR) spectroscopy and nuclear magnetic resonance (NMR) spectroscopy were employed to investigate the effect of base treatment on the various chemical bonds of the adsorbent. Scanning electron microscopy (SEM) has also been employed to determine structural effects of the alkali on the adsorbent. The results are summarized as follows: 1. Alkali conditioning is necessary to prepare the adsorbent for uranium uptake. ICP analysis showed that without alkali conditioning, no appreciable uranium adsorption occurs. 2. FTIR showed that the base converts amidoxime to carboxylate groups. 3. FTIR showed that formation of carboxylate groups is irreversible and reduces the selectivity of the adsorbent toward uranium. 4. NMR showed that alkali conditioning leads also to the formation of cyclic imidedioxime, which is suspected to bind uranium, vanadium, iron, copper, and

  20. Environmentally safe treatment of black liquor with Comamonas sp. B-9 under high-alkaline conditions.

    PubMed

    Zheng, Yu; Chai, Liyuan; Yang, Zhihui; Chen, Yuehui; Shi, Yan; Wang, Yangyang

    2014-02-01

    The strain Comamonas sp. B-9 was isolated from steeping fluid of erosive bamboo slips derived from Kingdom Wu during the Three-Kingdoms Dynasty of ancient China (A.D. 220-280). It could be used to treat black liquor (BL) with high-alkaline pH and with an initial chemical oxygen demand (COD) of 18,000-25,000 mg L(-1) , without the addition of other carbon and nitrogen sources. The results revealed that Comamonas sp. B-9 was capable of reducing the COD, color, and lignin content of BL by up to 56.8, 35.3, and 43.5%, respectively. High levels of laccase, manganese peroxidase, cellulase, and xylanase enzymatic activities were also observed, and these enzymes could play an important role in the biotreatment of BL. Further, GC-MS analysis showed that most of the compounds detected in BL after biotreatment with Comamonas sp. B-9 were diminished, while 4-methyl benzaldehyde, 3,4,5-trihydroxybenzoic acid ethyl ester, and 4-hydroxy-3,5-dimethoxy benzaldehyde were produced as metabolites. The presented results indicate that Comamonas sp. B-9 has potential application for the treatment of wastewaters from pulp and paper processing with high COD load under high-alkaline conditions.

  1. Transport-controlled kinetics of dissolution and precipitation in the sediments under alkaline and saline conditions

    SciTech Connect

    Qafoku, Nik; Ainsworth, Calvin C.; Szecsody, Jim E.; Qafoku, Odeta

    2004-07-01

    Millions of liters of high temperature, Al-rich, alkaline, and saline high-level waste (HLW) fluids were accidentally discharged onto the sediments at the Hanford Site, WA. Dissolution and precipitation are two processes that might occur when these fluids contact the sediments, but their occurrence and extent are not well studied under such extreme conditions. The objective, therefore, was to investigate the effects of geochemically stable, Al-rich, alkaline and saline solutions on the extent of soil mineral dissolution and precipitation during reactive transport through the sediments. Metal- and glass-free systems were used to conduct miscible-displacement experiments at 50 C under CO{sub 2} and O{sub 2} free conditions. Results showed that soil liquid phase composition changed significantly because of base-induced soil mineral dissolution and the subsequent releases of Si, K, Al, Fe(III), Fe(II), Ca, Mg, and Ba, into the aqueous phase. Transport-controlled release of these elements was time-dependent as evidenced by its extent varying with the fluid residence time. Initial dissolution rates calculated based on Si release in the column effluents in the second pore volume (PV) varied between 6.085 x 10{sup -11} and 5.377 x 10{sup -13} mol m{sup -2} s{sup -1}. They increased with base concentration and decreased with Al concentration in the leaching solution and the fluid residence time. Al precipitation rates (normalized to 1 kg of solution) varied in the range 0.4374 x 10{sup -6} ({+-} 0.019 x 10{sup -6}) and 1.069 x 10{sup -6} ({+-} 0.278 x 10{sup -6}) mol s{sup -1}. Al precipitation followed a first-order kinetics with an initial rate constant of 0.0701 h{sup -1} (half-life of 9.9 h at about 3 PV), which increased to 0.13706 h{sup -1} (half-life of 5.1 h at about 20 PV). The precipitates identified with SEM and confirmed from the modeling results, were mainly NO{sub 3}-cancrinite. NO{sub 3}-sodalite formation in the presence of high OH concentrations and

  2. Anaerobic digestion of the microalga Spirulina at extreme alkaline conditions: biogas production, metagenome, and metatranscriptome

    PubMed Central

    Nolla-Ardèvol, Vímac; Strous, Marc; Tegetmeyer, Halina E.

    2015-01-01

    A haloalkaline anaerobic microbial community obtained from soda lake sediments was used to inoculate anaerobic reactors for the production of methane rich biogas. The microalga Spirulina was successfully digested by the haloalkaline microbial consortium at alkaline conditions (pH 10, 2.0 M Na+). Continuous biogas production was observed and the obtained biogas was rich in methane, up to 96%. Alkaline medium acted as a CO2 scrubber which resulted in low amounts of CO2 and no traces of H2S in the produced biogas. A hydraulic retention time (HRT) of 15 days and 0.25 g Spirulina L−1 day−1 organic loading rate (OLR) were identified as the optimal operational parameters. Metagenomic and metatranscriptomic analysis showed that the hydrolysis of the supplied substrate was mainly carried out by Bacteroidetes of the “ML635J-40 aquatic group” while the hydrogenotrophic pathway was the main producer of methane in a methanogenic community dominated by Methanocalculus. PMID:26157422

  3. Transport-controlled kinetics of dissolution and precipitation in the sediments under alkaline and saline conditions

    NASA Astrophysics Data System (ADS)

    Qafoku, Nikolla P.; Ainsworth, Calvin C.; Szecsody, James E.; Qafoku, Odeta S.

    2004-07-01

    Over 1.6 million liters of radioactive, high-temperature, Al-rich, alkaline and saline high-level waste (HLW) fluids were accidentally discharged from tank leaks onto the sediments at the Hanford Site, Washington. In order to better understand processes that might occur during the migration of HLW through sediments and to estimate their extents, we studied the effects of Al-rich, alkaline and saline solutions on soil mineral dissolution and precipitation during reactive transport. Metal- and glass-free systems were used to conduct miscible-displacement experiments at 50 °C under CO 2 and O 2 free conditions. Results showed significant release of Si, K, Al, Fe, Ca, Mg, and Ba into the aqueous phase. The transport-controlled release of these elements was time dependent as evidenced by its extent varying with the fluid residence time. Silica initial dissolution rates (6.08 × 10 -11 and 5.38 × 10 -13 mol m -2 s -1) increased with base concentration, decreased with Al concentration, and decreased with fluid residence time. Aluminum precipitation rates varied in the range from 0.44 to 1.07 × 10 -6 mol s -1 and were faster in these column experiments than in previous batch studies. The initial rate constant of Al precipitation reaction was 0.07 h -1 (half-life of 9.9 h at about 3 PV); it increased up to 0.137 h -1 (half-life of 5.1 h at about 20 PV). The precipitates identified with SEM and suggested from the modeling results were mainly NO 3-cancrinite. SEM analyses also indicated the formation of sodalite when Al was not present in the leaching solution. In addition, results from modeling suggested the precipitation of brucite, goethite and gibbsite; the latter may precipitate in the presence of high Al concentrations. Aqueous and solid phase transformations caused by base-induced dissolution and subsequent secondary phases precipitation should be important determinants of the fate of contaminants and radionuclides in the vadose zone under alkaline and saline

  4. Dissolution of Uranium Oxides Under Alkaline Oxidizing Conditions

    SciTech Connect

    Smith, Steven C.; Peper, Shane M.; Douglas, Matthew; Ziegelgruber, Kate L.; Finn, Erin C.

    2009-11-01

    Bench scale experiments were conducted to determine the dissolution characteristics of uranium oxide powders (UO2, U3O8, and UO3) in aqueous peroxide-carbonate solutions. Experimental parameters included H2O2 concentration, carbonate counter cation (NH4+, Na+, K+, and Rb+), and pH. Results indicate the dissolution rate of UO2 in 1 M (NH4)2CO3 increases linearly with peroxide concentration ranging from 0.05 – 2 M. The three uranium oxide powders exhibited different dissolution patterns however, UO3 exhibited prompt complete dissolution. Carbonate counter cation affected the dissolution kinetics. There is minimal impact of solution pH, over the range 8.8 to 10.6, on initial dissolution rate.

  5. Uranium(VI) Diffusion in Sodium-Montmorillonite at Alkaline pH Conditions

    NASA Astrophysics Data System (ADS)

    Tinnacher, R. M.; Davis, J. A.; Tournassat, C.; Birkholzer, J. T.

    2015-12-01

    Diffusive transport of uranium(VI) in montmorillonite clay and bentonite has important implications for uranium(VI) mobility in engineered barrier systems or host rocks in high level radioactive waste repositories, and clay-rich soils and sediments in the environment. The prediction of uranium(VI) adsorption and diffusion in clay-rich media, however, is complicated by (1) the complexity of the mineralogical structure of montmorillonite, in terms of its pore-size distributions and available surface site types, and (2) the complex uranium(VI) solution speciation, which can include cationic, uncharged, and anionic complexes, depending on solution conditions. For instance, a partial or full exclusion of anions from negatively charged clay interlayer spaces could change the effective 'anion-accessible' porosity and decrease the diffusive flux of these solutes under steady state conditions. In contrast, weak cation exchange reactions can result in 'surface diffusion' of adsorbed cations, such as UO2OH+, in addition to diffusion in the liquid phase, resulting in greater diffusive fluxes at steady state. In order to investigate these complex interactions, we performed two, lab-scale uranium(VI) through-diffusion experiments in lightly compacted Na-montmorillonite at slightly different, alkaline pH conditions (average pH values of 8.69 and 8.87). Observed uranium(VI) diffusive fluxes were decreased by approximately an order of magnitude in comparison to a tritium tracer. This indicates a relevance of 'anion exclusion' effects, the full or partial exclusion of anionic U(VI)-carbonato species from clay interlayer spaces. In addition, uranium(VI) sorption reactions were shown to be relevant in the diffusion experiments, even at alkaline pH values of around 8.7 and 8.9, where uranium(VI) sorption is low compared to other pH conditions. Despite the similarity of pH conditions, different degrees of uranium(VI) retardation were determined for the two systems. Additionally, we

  6. Influence of calcium and silica on hydraulic properties of sodium montmorillonite assemblages under alkaline conditions.

    PubMed

    Kinsela, Andrew S; Tjitradjaja, Alice; Collins, Richard N; Waite, T David; Payne, Timothy E; Macdonald, Bennett C T; White, Ian

    2010-03-01

    A sodium-washed montmorillonite was exposed to calcium and silica under alkaline conditions in order to gain insight into possible interactions of engineered clay barriers and cementitious leachates found in many waste storage facilities. The changes in physico-chemical properties of the material were investigated using a combination of dead-end filtration, electrophoresis and scanning electron microscopy. The results show minimal differentiation between unaltered Na-montmorillonite samples at the two pH values tested (9 and 12), with the structure of the resulting assemblages arising from repulsive tactoid interactions. The addition of calcium (50 mM) greatly decreases the size of the structural network, and in doing so, increases the hydraulic conductivity approximately 65-fold, with the effect being greatest at pH 12. Whilst the addition of silica alone (10 mM) produced little change in the hydraulic properties of montmorillonite, its combined effect with calcium produced alterations to the structural assemblages that could not be accounted for by the presence of calcium alone. The likely binding of calcium with multiple silanol groups appears to enhance the retention of water within the Na-montmorillonite assemblage, whilst still allowing the fluent passage of water. The results confirm that polyvalent cations such as Ca(2+) may have a dramatic effect on the structural and hydraulic properties of montmorillonite assemblages while the effects of solutions containing both silicate and calcium are complex and influenced by silica-cation interactions.

  7. Effects of methanethiol on the biological oxidation of sulfide at natron-alkaline conditions.

    PubMed

    van den Bosch, Pim L F; Fortuny-Picornell, Marc; Janssen, Albert J H

    2009-01-15

    The effects of methanethiol (MT) on biological sulfide oxidation were studied in a continuously operated bioreactor, in which chemolithoautotrophic bacteria belonging to the genus Thioalkalivibrio convert hydrogen sulfide (H2S) at natron-alkaline conditions. Previous bioreactor experiments have shown that always a fraction of the H2S is oxidized to sulfate and thiosulfate. This is unwanted, as it leads to caustic requirements for pH control and the formation of a bleed stream to discharge these compounds from the process. The current research shows that due to the addition of MT, sulfate formation is prevented. As a result, all supplied H2S is completely converted into elemental sulfur. Treatment of a continuous supply of 51.0 mM day(-1) H2S and 79 microM day(-1) MT was feasible for a prolonged period, with 99 mol% selectivity for sulfur formation. A part of the MT reacts with the freshly produced sulfur particles to form dimethyl disulfide (DMDS) and dimethyl trisulfide (DMTS). Results indicate that MT, DMDS, and DMTS partly adsorb onto the biosulfur particles. At concentrations above 10 microM, these volatile organic sulfur compounds induce biomass decay.

  8. Facile synthesis of water-soluble carbon nano-onions under alkaline conditions.

    PubMed

    Ahmed, Gaber Hashem Gaber; Laíño, Rosana Badía; Calzón, Josefa Angela García; García, Marta Elena Díaz

    2016-01-01

    Carbonization of tomatoes at 240 °C using 30% (w/v) NaOH as catalyst produced carbon onions (C-onions), while solely carbon dots (C-dots) were obtained at the same temperature in the absence of the catalyst. Other natural materials, such as carrots and tree leaves (acer saccharum), under the same temperature and alkaline conditions did not produce carbon onions. XRD, FTIR, HRTEM, UV-vis spectroscopy, and photoluminescence analyses were performed to characterize the as-synthesized carbon nanomaterials. Preliminary tests demonstrate a capability of the versatile materials for chemical sensing of metal ions. The high content of lycopene in tomatoes may explain the formation of C-onions in alkaline media and a possible formation mechanism for such structures was outlined.

  9. Sensitivity of mitomycin C and nitrogen mustard crosslinks to extreme alkaline conditions

    SciTech Connect

    Gruenert, D.C.; Cleaver, J.E.

    1984-09-17

    DNA-DNA crosslinks in cells treated with mitomycin C, nitrogen mustard, or decarbamoyl mitomycin C were measured in alkaline isopycnic gradients as a function of pH. Crosslinks from cells treated with mitomycin C and nitrogen mustard, which react with DNA purines, could be detected at pH 12.5 but not at pH 14. No crosslinks from cells treated with decarbamoyl mitomycin C were detected at either pH. Previous studies with cells exposed to psoralen derivatives plus 360 nm light, which produce DNA-DNA crosslinks with pyrimidines, demonstrated stable crosslinks at pH 14. These studies indicate that DNA-DNA crosslinks involving DNA purines are much less stable at high pH than those involving pyrimidines, and that methods involving exposure to extreme alkaline conditions may give inaccurate information for some agents. 25 references, 1 figure.

  10. Facile synthesis of water-soluble carbon nano-onions under alkaline conditions

    PubMed Central

    Ahmed, Gaber Hashem Gaber; Laíño, Rosana Badía; Calzón, Josefa Angela García

    2016-01-01

    Summary Carbonization of tomatoes at 240 °C using 30% (w/v) NaOH as catalyst produced carbon onions (C-onions), while solely carbon dots (C-dots) were obtained at the same temperature in the absence of the catalyst. Other natural materials, such as carrots and tree leaves (acer saccharum), under the same temperature and alkaline conditions did not produce carbon onions. XRD, FTIR, HRTEM, UV–vis spectroscopy, and photoluminescence analyses were performed to characterize the as-synthesized carbon nanomaterials. Preliminary tests demonstrate a capability of the versatile materials for chemical sensing of metal ions. The high content of lycopene in tomatoes may explain the formation of C-onions in alkaline media and a possible formation mechanism for such structures was outlined. PMID:27335764

  11. Microbial reduction of Fe(III) under alkaline conditions relevant to geological disposal.

    PubMed

    Williamson, Adam J; Morris, Katherine; Shaw, Sam; Byrne, James M; Boothman, Christopher; Lloyd, Jonathan R

    2013-06-01

    To determine whether biologically mediated Fe(III) reduction is possible under alkaline conditions in systems of relevance to geological disposal of radioactive wastes, a series of microcosm experiments was set up using hyperalkaline sediments (pH ~11.8) surrounding a legacy lime working site in Buxton, United Kingdom. The microcosms were incubated for 28 days and held at pH 10. There was clear evidence for anoxic microbial activity, with consumption of lactate (added as an electron donor) concomitant with the reduction of Fe(III) as ferrihydrite (added as the electron acceptor). The products of microbial Fe(III) reduction were black and magnetic, and a range of analyses, including X-ray diffraction, transmission electron microscopy, X-ray absorption spectroscopy, and X-ray magnetic circular dichroism confirmed the extensive formation of biomagnetite in this system. The addition of soluble exogenous and endogenous electron shuttles such as the humic analogue anthraquinone-2,6-disulfonate and riboflavin increased both the initial rate and the final extent of Fe(III) reduction in comparison to the nonamended experiments. In addition, a soluble humic acid (Aldrich) also increased both the rate and the extent of Fe(III) reduction. These results show that microbial Fe(III) reduction can occur in conditions relevant to a geological disposal facility containing cement-based wasteforms that has evolved into a high pH environment over prolonged periods of time (>100,000 years). The potential impact of such processes on the biogeochemistry of a geological disposal facility is discussed, including possible coupling to the redox conditions and solubility of key radionuclides.

  12. Microbial Reduction of Fe(III) under Alkaline Conditions Relevant to Geological Disposal

    PubMed Central

    Williamson, Adam J.; Morris, Katherine; Shaw, Sam; Byrne, James M.; Boothman, Christopher

    2013-01-01

    To determine whether biologically mediated Fe(III) reduction is possible under alkaline conditions in systems of relevance to geological disposal of radioactive wastes, a series of microcosm experiments was set up using hyperalkaline sediments (pH ∼11.8) surrounding a legacy lime working site in Buxton, United Kingdom. The microcosms were incubated for 28 days and held at pH 10. There was clear evidence for anoxic microbial activity, with consumption of lactate (added as an electron donor) concomitant with the reduction of Fe(III) as ferrihydrite (added as the electron acceptor). The products of microbial Fe(III) reduction were black and magnetic, and a range of analyses, including X-ray diffraction, transmission electron microscopy, X-ray absorption spectroscopy, and X-ray magnetic circular dichroism confirmed the extensive formation of biomagnetite in this system. The addition of soluble exogenous and endogenous electron shuttles such as the humic analogue anthraquinone-2,6-disulfonate and riboflavin increased both the initial rate and the final extent of Fe(III) reduction in comparison to the nonamended experiments. In addition, a soluble humic acid (Aldrich) also increased both the rate and the extent of Fe(III) reduction. These results show that microbial Fe(III) reduction can occur in conditions relevant to a geological disposal facility containing cement-based wasteforms that has evolved into a high pH environment over prolonged periods of time (>100,000 years). The potential impact of such processes on the biogeochemistry of a geological disposal facility is discussed, including possible coupling to the redox conditions and solubility of key radionuclides. PMID:23524677

  13. Alkaline Leaching of Key, Non-Radioactive Components from Simulants and Hanford Tank Sludge 241-S-110: Results of FY01 Studies

    SciTech Connect

    Rapko, Brian M.; Vienna, John D.; Sinkov, Serguei I.; Kim, Jinseong; Cisar, Alan J.

    2002-09-10

    This study addressed three aspects in selected alkaline leaching: first, the use of oxidants persulfate, permanganate, and ferrate as selective chromium-leaching agents from washed Hanford Tank S-110 solids under varying conditions of hydroxide concentration, temperature, and time was investigated. Second, the selective dissolution of solids containing mercury(II) oxide under alkaline conditions was examined. Various compounds were studied for their effectiveness in dissolving mercury under varying conditions of time, temperature, and hydroxide concentration in the leachate. Three compounds were studied: cysteine, iodide, and diethyldithiophosphoric acid (DEDTPA). Finally, the possibility of whether an oxidant bound to an anion-exchange resin can be used to effectively oxidize chromium(III) in alkaline solutions was addressed. The experimental results remain ambiguous to date; further work is required to reach any definitive conclusions as to the effectiveness of this approach.

  14. Phenolic Compounds and Their Fates In Tropical Lepidopteran Larvae: Modifications In Alkaline Conditions.

    PubMed

    Vihakas, Matti; Gómez, Isrrael; Karonen, Maarit; Tähtinen, Petri; Sääksjärvi, Ilari; Salminen, Juha-Pekka

    2015-09-01

    Lepidopteran larvae encounter a variety of phenolic compounds while consuming their host plants. Some phenolics may oxidize under alkaline conditions prevailing in the larval guts, and the oxidation products may cause oxidative stress to the larvae. In this study, we aimed to find new ways to predict how phenolic compounds may be modified in the guts of herbivorous larvae. To do so, we studied the ease of oxidation of phenolic compounds from 12 tropical tree species. The leaf extracts were incubated in vitro in alkaline conditions, and the loss of total phenolics during incubation was used to estimate the oxidizability of extracts. The phenolic profiles of the leaf extracts before and after incubation were compared, revealing that some phenolic compounds were depleted during incubation. The leaves of the 12 tree species were each fed to 12 species of lepidopteran larvae that naturally feed on these trees. The phenolic profiles of larval frass were compared to those of in vitro incubated leaf extracts. These comparisons showed that the phenolic profiles of alkali-treated samples and frass samples were similar in many cases. This suggested that certain phenolics, such as ellagitannins, proanthocyanidins, and galloylquinic acid derivatives were modified by the alkaline pH of the larval gut. In other cases, the chromatographic profiles of frass and in vitro incubated leaf extracts were not similar, and new modifications of phenolics were detected in the frass. We conclude that the actual fates of phenolics in vivo are often more complicated than can be predicted by a simple in vitro method.

  15. Microbial reduction of U(VI) under alkaline conditions: implications for radioactive waste geodisposal.

    PubMed

    Williamson, Adam J; Morris, Katherine; Law, Gareth T W; Rizoulis, Athanasios; Charnock, John M; Lloyd, Jonathan R

    2014-11-18

    Although there is consensus that microorganisms significantly influence uranium speciation and mobility in the subsurface under circumneutral conditions, microbiologically mediated U(VI) redox cycling under alkaline conditions relevant to the geological disposal of cementitious intermediate level radioactive waste, remains unexplored. Here, we describe microcosm experiments that investigate the biogeochemical fate of U(VI) at pH 10-10.5, using sediments from a legacy lime working site, stimulated with an added electron donor, and incubated in the presence and absence of added Fe(III) as ferrihydrite. In systems without added Fe(III), partial U(VI) reduction occurred, forming a U(IV)-bearing non-uraninite phase which underwent reoxidation in the presence of air (O2) and to some extent nitrate. By contrast, in the presence of added Fe(III), U(VI) was first removed from solution by sorption to the Fe(III) mineral, followed by bioreduction and (bio)magnetite formation coupled to formation of a complex U(IV)-bearing phase with uraninite present, which also underwent air (O2) and partial nitrate reoxidation. 16S rRNA gene pyrosequencing showed that Gram-positive bacteria affiliated with the Firmicutes and Bacteroidetes dominated in the post-reduction sediments. These data provide the first insights into uranium biogeochemistry at high pH and have significant implications for the long-term fate of uranium in geological disposal in both engineered barrier systems and the alkaline, chemically disturbed geosphere.

  16. Inhibition of microbiological sulfide oxidation by methanethiol and dimethyl polysulfides at natron-alkaline conditions.

    PubMed

    van den Bosch, Pim L F; de Graaff, Marco; Fortuny-Picornell, Marc; van Leerdam, Robin C; Janssen, Albert J H

    2009-06-01

    To avoid problems related to the discharge of sulfidic spent caustics, a biotechnological process is developed for the treatment of gases containing both hydrogen sulfide and methanethiol. The process operates at natron-alkaline conditions (>1 mol L(-1) of sodium- and potassium carbonates and a pH of 8.5-10) to enable the treatment of gases with a high partial CO(2) pressure. In the process, methanethiol reacts with biologically produced sulfur particles to form a complex mixture predominantly consisting of inorganic polysulfides, dimethyl disulfide (DMDS), and dimethyl trisulfide (DMTS). The effect of these organic sulfur compounds on the biological oxidation of sulfide to elemental sulfur was studied with natron-alkaliphilic bacteria belonging to the genus Thioalkalivibrio. Biological oxidation rates were reduced by 50% at 0.05 mM methanethiol, while for DMDS and DMTS, this was estimated to occur at 1.5 and 1.0 mM, respectively. The inhibiting effect of methanethiol on biological sulfide oxidation diminished due to its reaction with biologically produced sulfur particles. This reaction increases the feasibility of biotechnological treatment of gases containing both hydrogen sulfide and methanethiol at natron-alkaline conditions.

  17. Interannual sedimentary effluxes of alkalinity in the southern North Sea: Model results compared with summer observations.

    NASA Astrophysics Data System (ADS)

    Paetsch, Johannes; Kuehn, Wilfried; Six, Katharina

    2016-04-01

    Alkalinity generation in the sediment of the southern North Sea is the focus of several recent studies. One motivation for these efforts is the potentially enhanced buffering capacity of anthropogenic CO2 invasion into the corresponding pelagic system. An adaptation of a global multilayer sediment model (Heinze et al., 1999) in combination with a pelagic ecosystem model for shelf sea dynamics was used to study the benthic reactions on very different annual cycles (2001 - 2009) including the River Elbe summer flooding in 2002. The focus of this study is the efflux of alkalinity, their different contributors (aerobic respiration, denitrification, net sulfate reduction, calcite dissolution, nitrification) and their seasonal and interannual cycles. Similar to the observations covering the southern North Sea (Brenner et al., 2015) the model results show large horizontal gradients from the near-shore high productive areas with benthic remineralization up to Rmin = 10.6 mol C m-2 yr-1 and TA generation RTA = 2 mol C m-2 yr-1 to off-shore moderate productive areas with mean Rmin = 2.5 mol C m-2 yr-1 and mean TA generation RTA = 0.4 mol C m-2 yr-1. Beside calcite dissolution, aerobic respiration (producing ammonium) and denitrification are the largest contributors to alkalinity generation. Nitrification is reducing alkalinity in the sediment. Due to low regenerated primary production in summer, the year 2001 exhibits the lowest input of particulate organic matter into the sediment (POCexp=2.3 mol C m-2 yr-1), while the year 2003 exhibits the highest export production (POCexp=2.6 mol C m-2 yr-1). The biogeochemical reactions and the effluxes from the sediment follow these pelagic amplitudes with a time lag of about one year with damped amplitudes. References Brenner, H., Braeckman, U., Le Guitton, M., Meysman, F.J.R., 2015. The impact of sedimentary alkalinity release on the water column CO2 system in the North Sea. Biogeosiences Discussion, 12(15): 12395-12453. Heinze, C

  18. Microbial impacts on (99m)Tc migration through sandstone under highly alkaline conditions relevant to radioactive waste disposal.

    PubMed

    Smith, Sarah L; Boothman, Christopher; Williams, Heather A; Ellis, Beverly L; Wragg, Joanna; West, Julia M; Lloyd, Jonathan R

    2017-01-01

    Geological disposal of intermediate level radioactive waste in the UK is planned to involve the use of cementitious materials, facilitating the formation of an alkali-disturbed zone within the host rock. The biogeochemical processes that will occur in this environment, and the extent to which they will impact on radionuclide migration, are currently poorly understood. This study investigates the impact of biogeochemical processes on the mobility of the radionuclide technetium, in column experiments designed to be representative of aspects of the alkali-disturbed zone. Results indicate that microbial processes were capable of inhibiting (99m)Tc migration through columns, and X-ray radiography demonstrated that extensive physical changes had occurred to the material within columns where microbiological activity had been stimulated. The utilisation of organic acids under highly alkaline conditions, generating H2 and CO2, may represent a mechanism by which microbial processes may alter the hydraulic conductivity of a geological environment. Column sediments were dominated by obligately alkaliphilic H2-oxidising bacteria, suggesting that the enrichment of these bacteria may have occurred as a result of H2 generation during organic acid metabolism. The results from these experiments show that microorganisms are able to carry out a number of processes under highly alkaline conditions that could potentially impact on the properties of the host rock surrounding a geological disposal facility for intermediate level radioactive waste.

  19. Sorption Behavior of Iodine on Allophane under Acid and Alkaline Conditions - 12203

    SciTech Connect

    Amemiya, Kiyoshi; Nakano, Masashi

    2012-07-01

    In the safety assessment of TRU geological disposal, Iodine-129 (I-129) is considered a key radionuclide. In Japan the reference buffer material within the repository is a bentonite based sand mixture, which is lacking in iodine adsorbent capacity. Additives or alternative buffer materials that can enhance iodine adsorption are desired. Allophane, a common soil material in Japan, is a potential candidate to aid in iodine retention. In order to assess the potential for improvement of buffer and backfill material to limit release of I-129, the sorption behavior of iodine (IO{sub 3}{sup -} and I{sup -}) on allophane was examined in this research. The sorption behavior of IO{sub 3}{sup -} by allophane is strong in acidic conditions, and markedly reduced in alkaline conditions. The K{sub d} values of IO{sub 3}{sup -} are approximately 0.4 m{sup 3}/kg (pH=5), 0.03 m{sup 3}/kg (pH=8), 0.011 m{sup 3}/kg (pH=9), 0.005 m{sup 3}/kg (pH=10). Conversely, the K{sub d} value of I{sup -} is as small as 0.01 m{sup 3}/kg in acidic conditions, and much smaller in alkaline conditions. The numerical analysis shows that a maximum release rate of I-129 from the engineered barrier in the geological disposal system decreased approximately one order of magnitude and the K{sub d} of the buffer increased up to 0.1 m{sup 3}/kg by applying allophane soils to engineered barriers. (authors)

  20. Identification of a New Marine Bacterial Strain SD8 and Optimization of Its Culture Conditions for Producing Alkaline Protease.

    PubMed

    Cui, Hongxia; Yang, Muyang; Wang, Liping; Xian, Cory J

    2015-01-01

    While much attention has been given to marine microorganisms for production of enzymes, which in general are relatively more stable and active compared to those from plants and animals, studies on alkaline protease production from marine microorganisms have been very limited. In the present study, the alkaline protease producing marine bacterial strain SD8 isolated from sea muds in the Geziwo Qinhuangdao sea area of China was characterized and its optimal culture conditions were investigated. Strain SD8 was initially classified to belong to genus Pseudomonas by morphological, physiological and biochemical characterizations, and then through 16S rDNA sequence it was identified to be likely Pseudomonas hibiscicola. In addition, the culture mediums, carbon sources and culture conditions of strain SD8 were optimized for maximum production of alkaline protease. Optimum enzyme production (236U/mL when cultured bacteria being at 0.75 mg dry weight/mL fermentation broth) was obtained when the isolate at a 3% inoculum size was grown in LB medium at 20 mL medium/100mL Erlenmeyer flask for 48h culture at 30°C with an initial of pH 7.5. This was the first report of strain Pseudomonas hibiscicola secreting alkaline protease, and the data for its optimal cultural conditions for alkaline protease production has laid a foundation for future exploration for the potential use of SD8 strain for alkaline protease production.

  1. Identification of a New Marine Bacterial Strain SD8 and Optimization of Its Culture Conditions for Producing Alkaline Protease

    PubMed Central

    Cui, Hongxia; Yang, Muyang; Wang, Liping; Xian, Cory J.

    2015-01-01

    While much attention has been given to marine microorganisms for production of enzymes, which in general are relatively more stable and active compared to those from plants and animals, studies on alkaline protease production from marine microorganisms have been very limited. In the present study, the alkaline protease producing marine bacterial strain SD8 isolated from sea muds in the Geziwo Qinhuangdao sea area of China was characterized and its optimal culture conditions were investigated. Strain SD8 was initially classified to belong to genus Pseudomonas by morphological, physiological and biochemical characterizations, and then through 16S rDNA sequence it was identified to be likely Pseudomonas hibiscicola. In addition, the culture mediums, carbon sources and culture conditions of strain SD8 were optimized for maximum production of alkaline protease. Optimum enzyme production (236U/mL when cultured bacteria being at 0.75 mg dry weight/mL fermentation broth) was obtained when the isolate at a 3% inoculum size was grown in LB medium at 20 mL medium/100mL Erlenmeyer flask for 48h culture at 30°C with an initial of pH 7.5. This was the first report of strain Pseudomonas hibiscicola secreting alkaline protease, and the data for its optimal cultural conditions for alkaline protease production has laid a foundation for future exploration for the potential use of SD8 strain for alkaline protease production. PMID:26716833

  2. Use of highly alkaline conditions to improve cost-effectiveness of algal biotechnology.

    PubMed

    Canon-Rubio, Karen A; Sharp, Christine E; Bergerson, Joule; Strous, Marc; De la Hoz Siegler, Hector

    2016-02-01

    Phototrophic microorganisms have been proposed as an alternative to capture carbon dioxide (CO2) and to produce biofuels and other valuable products. Low CO2 absorption rates, low volumetric productivities, and inefficient downstream processing, however, currently make algal biotechnology highly energy intensive, expensive, and not economically competitive to produce biofuels. This mini-review summarizes advances made regarding the cultivation of phototrophic microorganisms at highly alkaline conditions, as well as other innovations oriented toward reducing the energy input into the cultivation and processing stages. An evaluation, in terms of energy requirements and energy return on energy invested, is performed for an integrated high-pH, high-alkalinity growth process that uses biofilms. Performance in terms of productivity and expected energy return on energy invested is presented for this process and is compared to previously reported life cycle assessments (LCAs) for systems at near-neutral pH. The cultivation of alkaliphilic phototrophic microorganisms in biofilms is shown to have a significant potential to reduce both energy requirements and capital costs.

  3. Anditalea andensis ANESC-ST--An Alkaliphilic Halotolerant Bacterium Capable of Electricity Generation under Alkaline-Saline Conditions.

    PubMed

    Shi, Wei; Wang, Victor Bochuan; Zhao, Cui-E; Zhang, Qichun; Loo, Say Chye Joachim; Yang, Liang; Xu, Chenjie

    2015-01-01

    A great challenge in wastewater bioremediation is the sustained activity of viable microorganisms, which can contribute to the breakdown of waste contaminants, especially in alkaline pH conditions. Identification of extremophiles with bioremediation capability can improve the efficiency of wastewater treatment. Here, we report the discovery of an electrochemically active alkaliphilic halotolerant bacterium, Anditalea andensis ANESC-ST (=CICC10485T=NCCB 100412T), which is capable of generating bioelectricity in alkaline-saline conditions. A. andensis ANESC-ST was shown to grow in alkaline conditions between pH 7.0-11.0 and also under high salt condition (up to 4 wt% NaCl). Electrical output was further demonstrated in microbial fuel cells (MFCs) with an average current density of ~0.5 µA/cm2, even under the harsh condition of 4 wt% NaCl and pH 9.0. Subsequent introduction of secreted extracellular metabolites into MFCs inoculated with Escherichia coli or Pseudomonas aeruginosa yielded enhanced electrical output. The ability of A. andensis ANESC-ST to generate energy under alkaline-saline conditions points towards a solution for bioelectricity recovery from alkaline-saline wastewater. This is the first report of A.andensis ANESC-ST producing bioelectricity at high salt concentration and pH.

  4. Effects of alkaline pretreatments and acid extraction conditions on the acid-soluble collagen from grass carp (Ctenopharyngodon idella) skin.

    PubMed

    Liu, Dasong; Wei, Guanmian; Li, Tiancheng; Hu, Jinhua; Lu, Naiyan; Regenstein, Joe M; Zhou, Peng

    2015-04-01

    This study investigated the effects of alkaline pretreatments and acid extraction conditions on the production of acid-soluble collagen (ASC) from grass carp skin. For alkaline pretreatment, 0.05 and 0.1M NaOH removed non-collagenous proteins without significant loss of ASC at 4, 10, 15 and 20 °C; while 0.2 and 0.5M NaOH caused significant loss of ASC, and 0.5M NaOH caused structural modification of ASC at 15 and 20 °C. For acid extraction at 4, 10, 15 and 20 °C, ASC was partly extracted by 0.1 and 0.2M acetic acid, while 0.5 and 1.0M acetic acid resulted in almost complete extraction. The processing conditions involving 0.05-0.1M NaOH for pretreatment, 0.5M acetic acid for extraction and 4-20 °C for both pretreatment and extraction, produced ASC with the structural integrity being well maintained and hence were recommended to prepare ASC from grass carp skin in practical application.

  5. Impact of growth conditions on susceptibility of five microbial species to alkaline stress.

    PubMed

    Brändle, Nathalie; Zehnder, Matthias; Weiger, Roland; Waltimo, Tuomas

    2008-05-01

    The effects of different growth conditions on the susceptibility of five taxa to alkaline stress were investigated. Enterococcus faecalis ATCC 29212, Streptococcus sobrinus OMZ 176, Candida albicans ATCC 90028, Actinomyces naeslundii ATCC 12104, and Fusobacterium nucleatum ATCC 10953 were grown as planktonic cells, allowed to adhere to dentin for 24 hours, grown as monospecies or multispecies biofilms on dentin under anaerobic conditions with a serum-enriched nutrient supply at 37 degrees C for 5 days. In addition, suspended biofilm microorganisms and 5-day old planktonic multispecies cultures were used. Microbial recovery upon direct exposure to saturated calcium hydroxide solution (pH 12.5) for 10 and 100 minutes was compared with control exposure to physiologic saline. Planktonic microorganisms were most susceptible; only E. faecalis and C. albicans survived in saturated solution for 10 minutes, the latter also for 100 minutes. Dentin adhesion was the major factor in improving the resistance of E. faecalis and A. naeslundii to calcium hydroxide, whereas the multispecies context in a biofilm was the major factor in promoting resistance of S. sobrinus to the disinfectant. In contrast, the C. albicans response to calcium hydroxide was not influenced by the growth condition. Adherence to dentin and interspecies interactions in a biofilm appear to differentially affect the sensitivity of microbial species to calcium hydroxide.

  6. Review of the complexation of tetravalent actinides by ISA and gluconate under alkaline to hyperalkaline conditions.

    PubMed

    Gaona, X; Montoya, V; Colàs, E; Grivé, M; Duro, L

    2008-12-12

    Isosaccharinic (ISA) and gluconic acids (GLU) are polyhydroxy carboxylic compounds showing a high affinity to metal complexation. Both organic ligands are expected in the cementitious environments usually considered for the disposal of low- and intermediate-level radioactive wastes. The hyperalkaline conditions imposed by cementitious materials contribute to the formation of ISA through cellulose degradation, whereas GLU is commonly used as a concrete additive. Despite the high stability attributed to ISA/GLU complexes of tetravalent actinides, the number and reliability of available experimental studies is still limited. This work aims at providing a general and comprehensive overview of the state of the art regarding Th, U(IV), Np(IV), and Pu(IV) complexes with ISA and GLU. In the presence of ISA/GLU concentrations in the range 10(-5)-10(-2) M and absence of calcium, An(IV)(OH)x(L)y complexes (An(IV)=Th, U(IV), Np(IV), Pu(IV); L=ISA, GLU) are expected to dominate the aqueous speciation of tetravalent actinides in the alkaline pH range. There is a moderate agreement among their stability, although the stoichiometry of certain An(IV)-GLU complexes is still ill-defined. Under hyperalkaline conditions and presence of calcium, the species CaTh(OH)4(L)2(aq) has been described for both ISA and GLU, and similar complexes may be expected to form with other tetravalent actinides. In the present work, the available thermodynamic data for An(IV)-ISA/GLU complexes have been reviewed and re-calculated to ensure the internal consistency of the stability constants assessed. Further modelling exercises, estimations based on Linear Free-Energy Relationships (LFER) among tetravalent actinides, as well as direct analogies between ISA and GLU complexes have also been performed. This approach has led to the definition of a speciation scheme for the complexes of Th, U(IV), Np(IV) and Pu(IV) with ISA and GLU forming in alkaline to hyperalkaline pH conditions, both in the absence and

  7. Review of the complexation of tetravalent actinides by ISA and gluconate under alkaline to hyperalkaline conditions

    NASA Astrophysics Data System (ADS)

    Gaona, X.; Montoya, V.; Colàs, E.; Grivé, M.; Duro, L.

    2008-12-01

    Isosaccharinic (ISA) and gluconic acids (GLU) are polyhydroxy carboxylic compounds showing a high affinity to metal complexation. Both organic ligands are expected in the cementitious environments usually considered for the disposal of low- and intermediate-level radioactive wastes. The hyperalkaline conditions imposed by cementitious materials contribute to the formation of ISA through cellulose degradation, whereas GLU is commonly used as a concrete additive. Despite the high stability attributed to ISA/GLU complexes of tetravalent actinides, the number and reliability of available experimental studies is still limited. This work aims at providing a general and comprehensive overview of the state of the art regarding Th, U(IV), Np(IV), and Pu(IV) complexes with ISA and GLU. In the presence of ISA/GLU concentrations in the range 10 - 5 -10 - 2 M and absence of calcium, An(IV)(OH) x(L) y complexes (An(IV) = Th, U(IV), Np(IV), Pu(IV); L = ISA, GLU) are expected to dominate the aqueous speciation of tetravalent actinides in the alkaline pH range. There is a moderate agreement among their stability, although the stoichiometry of certain An(IV)-GLU complexes is still ill-defined. Under hyperalkaline conditions and presence of calcium, the species CaTh(OH) 4(L) 2(aq) has been described for both ISA and GLU, and similar complexes may be expected to form with other tetravalent actinides. In the present work, the available thermodynamic data for An(IV)-ISA/GLU complexes have been reviewed and re-calculated to ensure the internal consistency of the stability constants assessed. Further modelling exercises, estimations based on Linear Free-Energy Relationships (LFER) among tetravalent actinides, as well as direct analogies between ISA and GLU complexes have also been performed. This approach has led to the definition of a speciation scheme for the complexes of Th, U(IV), Np(IV) and Pu(IV) with ISA and GLU forming in alkaline to hyperalkaline pH conditions, both in the

  8. Alkaline saponification results in decomposition of tocopherols in milk and ovine blood plasma.

    PubMed

    Czauderna, M; Kowalczyk, J

    2007-10-15

    Alkaline saponification of entire sample matrixes for quantification of alpha-, gamma-, delta-tocopherols (alpha-T, gamma-T, delta-T) and alpha-tocopherol acetate (alpha-TAc) was examined. High-performance liquid chromatography was used to measure alpha-T, gamma-T, delta-T and alpha-TAc in tocopherol standard solutions, milk and ovine blood plasma. Saponification in the presence of vitamin C decreases the concentration of tocopherols, especially alpha-T and gamma-T. The poor recovery of tocopherols is due to the decomposition of tocopherols in saponified standard solutions, milk or plasma. Saponification of samples in the presence of 2,[6]-ditertbutyl-p-cresol or flushed only with a stream of Ar resulted in a major decrease in the concentrations of alpha-T, gamma-T, delta-T and alpha-TAc in comparison with saponification in the presence of vitamin C.

  9. Ethanol production from glycerol-containing biodiesel waste by Klebsiella variicola shows maximum productivity under alkaline conditions.

    PubMed

    Suzuki, Toshihiro; Nishikawa, Chiaki; Seta, Kohei; Shigeno, Toshiya; Nakajima-Kambe, Toshiaki

    2014-05-25

    Biodiesel fuel (BDF) waste contains large amounts of crude glycerol as a by-product, and has a high alkaline pH. With regard to microbial conversion of ethanol from BDF-derived glycerol, bacteria that can produce ethanol at alkaline pH have not been reported to date. Isolation of bacteria that shows maximum productivity under alkaline conditions is essential to effective production of ethanol from BDF-derived glycerol. In this study, we isolated the Klebsiella variicola TB-83 strain, which demonstrated maximum ethanol productivity at alkaline pH. Strain TB-83 showed effective usage of crude glycerol with maximum ethanol production at pH 8.0-9.0, and the culture pH was finally neutralized by formate, a by-product. In addition, the ethanol productivity of strain TB-83 under various culture conditions was investigated. Ethanol production was more efficient with the addition of yeast extract. Strain TB-83 produced 9.8 g/L ethanol (0.86 mol/mol glycerol) from cooking oil-derived BDF waste. Ethanol production from cooking oil-derived BDF waste was higher than that of new frying oil-derived BDF and pure-glycerol. This is the first report to demonstrate that the K. variicola strain TB-83 has the ability to produce ethanol from glycerol at alkaline pH.

  10. Speciation and Release Kinetics of Cadmium in an Alkaline Paddy Soil Under Various Flooding Periods and Draining Conditions

    SciTech Connect

    S Khaokaew; R Chaney; G Landrot; M Ginder-Vogel; D Sparks

    2011-12-31

    This study determined Cd speciation and release kinetics in a Cd-Zn cocontaminated alkaline paddy soil, under various flooding periods and draining conditions, by employing synchrotron-based techniques, and a stirred-flow kinetic method. Results revealed that varying flooding periods and draining conditions affected Cd speciation and its release kinetics. Linear least-squares fitting (LLSF) of bulk X-ray absorption fine structure (XAFS) spectra of the air-dried, and the 1 day-flooded soil samples, showed that at least 50% of Cd was bound to humic acid. Cadmium carbonates were found as the major species at most flooding periods, while a small amount of cadmium sulfide was found after the soils were flooded for longer periods. Under all flooding and draining conditions, at least 14 mg/kg Cd was desorbed from the soil after a 2-hour desorption experiment. The results obtained by micro X-ray fluorescence ({mu}-XRF) spectroscopy showed that Cd was less associated with Zn than Ca, in most soil samples. Therefore, it is more likely that Cd and Ca will be present in the same mineral phases rather than Cd and Zn, although the source of these two latter elements may originate from the same surrounding Zn mines in the Mae Sot district.

  11. Alkaline phosphatase activity related to phosphorus stress of microphytoplankton in different trophic conditions

    NASA Astrophysics Data System (ADS)

    Ivančić, Ingrid; Pfannkuchen, Martin; Godrijan, Jelena; Djakovac, Tamara; Marić Pfannkuchen, Daniela; Korlević, Marino; Gašparović, Blaženka; Najdek, Mirjana

    2016-08-01

    The northern Adriatic (NA) is a favorable basin for studying the adaptive strategies of plankton to a variety of conditions along the steep gradients of environmental parameters over the year. Earlier studies identified phosphorus (P)-limitation as one of the key stresses within the NA that shape the biological response in terms of biodiversity and metabolic adjustments. A wide range of reports supports the notion that P-limitation is a globally important phenomenon in aquatic ecosystems. In this study P stress of marine microphytoplankton was determined at species level along a trophic gradient in the NA. In P-limitation all species with considerable contributions to the diatom community expressed alkaline phosphatase activity (APA), compared to only a few marginal dinoflagellate species. Nevertheless, APA expressing species did not always dominate the phytoplankton community, suggesting that APA is also an important strategy for species to survive and maintain active metabolism outside of their mass abundances. A symbiotic relationship could be supposed for diatoms that did not express APA themselves and probably benefited from APA expressed by attached bacteria. APA was not expressed by any microphytoplankton species during the autumn when P was not limiting, while most of the species did express APA during the P-limitation. This suggests that APA expression is regulated by orthophosphate availability. The methods employed in this study allowed the microscopic detection of APA for each microphytoplankton cell with simultaneous morphologic/taxonomic analysis. This approach uncovered a set of strategies to compete in P-limited conditions within the marine microphytoplankton community. This study confirms the role of P-limitation as a shaping factor in marine ecosystems.

  12. Computational Design of a pH Stable Enzyme: Understanding Molecular Mechanism of Penicillin Acylase's Adaptation to Alkaline Conditions

    PubMed Central

    Suplatov, Dmitry; Panin, Nikolay; Kirilin, Evgeny; Shcherbakova, Tatyana; Kudryavtsev, Pavel; Švedas, Vytas

    2014-01-01

    Protein stability provides advantageous development of novel properties and can be crucial in affording tolerance to mutations that introduce functionally preferential phenotypes. Consequently, understanding the determining factors for protein stability is important for the study of structure-function relationship and design of novel protein functions. Thermal stability has been extensively studied in connection with practical application of biocatalysts. However, little work has been done to explore the mechanism of pH-dependent inactivation. In this study, bioinformatic analysis of the Ntn-hydrolase superfamily was performed to identify functionally important subfamily-specific positions in protein structures. Furthermore, the involvement of these positions in pH-induced inactivation was studied. The conformational mobility of penicillin acylase in Escherichia coli was analyzed through molecular modeling in neutral and alkaline conditions. Two functionally important subfamily-specific residues, Gluβ482 and Aspβ484, were found. Ionization of these residues at alkaline pH promoted the collapse of a buried network of stabilizing interactions that consequently disrupted the functional protein conformation. The subfamily-specific position Aspβ484 was selected as a hotspot for mutation to engineer enzyme variant tolerant to alkaline medium. The corresponding Dβ484N mutant was produced and showed 9-fold increase in stability at alkaline conditions. Bioinformatic analysis of subfamily-specific positions can be further explored to study mechanisms of protein inactivation and to design more stable variants for the engineering of homologous Ntn-hydrolases with improved catalytic properties. PMID:24959852

  13. Computational design of a pH stable enzyme: understanding molecular mechanism of penicillin acylase's adaptation to alkaline conditions.

    PubMed

    Suplatov, Dmitry; Panin, Nikolay; Kirilin, Evgeny; Shcherbakova, Tatyana; Kudryavtsev, Pavel; Svedas, Vytas

    2014-01-01

    Protein stability provides advantageous development of novel properties and can be crucial in affording tolerance to mutations that introduce functionally preferential phenotypes. Consequently, understanding the determining factors for protein stability is important for the study of structure-function relationship and design of novel protein functions. Thermal stability has been extensively studied in connection with practical application of biocatalysts. However, little work has been done to explore the mechanism of pH-dependent inactivation. In this study, bioinformatic analysis of the Ntn-hydrolase superfamily was performed to identify functionally important subfamily-specific positions in protein structures. Furthermore, the involvement of these positions in pH-induced inactivation was studied. The conformational mobility of penicillin acylase in Escherichia coli was analyzed through molecular modeling in neutral and alkaline conditions. Two functionally important subfamily-specific residues, Gluβ482 and Aspβ484, were found. Ionization of these residues at alkaline pH promoted the collapse of a buried network of stabilizing interactions that consequently disrupted the functional protein conformation. The subfamily-specific position Aspβ484 was selected as a hotspot for mutation to engineer enzyme variant tolerant to alkaline medium. The corresponding Dβ484N mutant was produced and showed 9-fold increase in stability at alkaline conditions. Bioinformatic analysis of subfamily-specific positions can be further explored to study mechanisms of protein inactivation and to design more stable variants for the engineering of homologous Ntn-hydrolases with improved catalytic properties.

  14. Abiotic Synthesis of Methane Under Alkaline Hydrothermal Conditions: the Effect of pH in Heterogeneous Catalysis

    NASA Astrophysics Data System (ADS)

    Foustoukos, D. I.; Qi, F.; Seyfried, W. E.

    2004-12-01

    Abiotic formation of methane in hydrothermal reaction zones at mid-ocean ridges likely occurs by Fischer-Tropsch catalytic processes involving reaction of CO2-bearing fluids with mineral surfaces. The elevated concentrations of dissolved methane and low molecular weight hydrocarbons observed in high temperature vent fluids issuing from ultramafic-hosted hydrothermal systems, in particular, suggest that Fe and Cr-bearing mineral phases attribute as catalysts, enhancing abiotic production of alkanes. The chemi-adsorption of dissolved CO2 on the catalytic mineral surface, however, might be influenced by a pH dependent surface electron charge developed within the mineral-fluid interface. Thus, a series of experiments was conducted to evaluate the role of pH on rates of carbon reduction in fluids coexisting with Fe-oxides at 390 degree C and 400 bars. At two distinct pH conditions, acidic (pH = 5) and alkaline (pH = 8.8), the abiotic production of isotopically labelled CH4(aq) was monitored during FeO reaction with aqueous NaCl-NaHCO3-H2-bearing fluid (0.56 mol/kg NaCl, 0.03 mol/kg NaH13CO3). Despite the lower H2(aq) concentrations (120 mmol/kg) in the high pH system, concentrations of abiogenic methane attained values of 195 umol/kg and 120 umol/kg respectively, suggesting enhanced catalytic properties of mineral under moderately high pH. X-ray photoelectron spectroscopy (XPS), performed on unreacted and final solid products, reveal the significantly greater abundances of alkyl (C-C-) groups on the surface of FeO oxidized at elevated pH, in comparison with mineral reacted at low pH conditions. Thus, enhanced adsorption of dissolved CO2 and the resulting Fischer-Tropsch formation of alkyl groups likely contributes to methane production observed at alkaline conditions. Introducing the effect of pH in the Fischer-Tropsch mechanism of alkane formation has important implications for the recently discovered Lost City ultramafic-hosted hydrothermal system, where elevated p

  15. Tested Demonstrations. The Stepwise Reduction of Permanganate in Alkaline Conditions: A Lecture Demonstration.

    ERIC Educational Resources Information Center

    Ruoff, Peter; Riley, Megan

    1987-01-01

    Describes a chemistry experiment where an alkaline ice-cold permanganate solution is reduced by adding dropwise a cold diluted hydrogen peroxide solution. Outlines the course of the reduction through the various oxidation states of manganese with their characteristic colors. (TW)

  16. Effects of Different Saline-Alkaline Conditions on the Characteristics of Phytoplankton Communities in the Lakes of Songnen Plain, China

    PubMed Central

    Zang, Shuying; Fan, Yawen; Ye, Huaxiang

    2016-01-01

    Many lakes located in the Songnen Plain of China exhibit a high saline-alkaline level. 25 lakes in the Songnen Plain were selected as research objects in this study. Water samples in these lakes were collected from June to August in 2008. Total Dissolved Solids (TDS) and Total Alkalinity (TA) were measured to assess the saline-alkaline level, and partial canonical correspondence analysis (CCA) was conducted as well. The results show that the majority of these lakes in the study area could be categorized into HCO3−-Na+-I type. According to the TDS assessment, of the total 25 lakes, there are 14 for freshwater, 7 for brackish water and 4 for saltwater; and the respective range of TA was from 0.98 to 40.52. The relationship between TA and TDS indicated significant linear relationship (R2 = 0.9292) in the HCO3−-Na+-I type lakes in the Songnen Plain. There was a general trend that cell density, genera richness and taxonomic diversity decreased with the increase of saline-alkaline gradient, whereas a contrary trend was observed for the proportion of dominant species. When the TDS values were above 3×103mg/L and the TA values were above 15mg/L, there was a significant reduction in cell density, genera richness and biodiversity, and their corresponding values were respectively below 10×106 (ind/L), 15 and approximately 2.5. Through the partial canonical correspondence analysis (CCA), 10.7% of the genera variation was explained by pure saline-alkaline variables. Cyclotella meneghiniana, Melosira ambigua and Melosira granulate were found to become the dominant species in most of these lakes, which indicated that there may be rather wide saline-alkaline niches for common dominant species. About one-quarters of the genera which have certain tolerance to salinity and alkalinity preferred to live in the regions with relatively higher saline-alkaline levels in this study. PMID:27749936

  17. Chemical speciation of neptunium(VI) under strongly alkaline conditions. Structure, composition, and oxo ligand exchange.

    PubMed

    Clark, David L; Conradson, Steven D; Donohoe, Robert J; Gordon, Pamela L; Keogh, D Webster; Palmer, Phillip D; Scott, Brian L; Tait, C Drew

    2013-04-01

    Hexavalent neptunium can be solubilized in 0.5-3.5 M aqueous MOH (M = Li(+), Na(+), NMe4(+) = TMA(+)) solutions. Single crystals were obtained from cooling of a dilute solution of Co(NH3)6Cl3 and NpO2(2+) in 3.5 M [N(Me)4]OH to 5 °C. A single-crystal X-ray diffraction study revealed the molecular formula of [Co(NH3)6]2[NpO2(OH)4]3·H2O, isostructural with the uranium analogue. The asymmetric unit contains three distinct NpO2(OH)4(2-) ions, each with pseudooctahedral coordination geometry with trans-oxo ligands. The average Np═O and Np-OH distances were determined to be 1.80(1) and 2.24(1) Å, respectively. EXAFS data and fits at the Np L(III)-edge on solid [Co(NH3)6]2[NpO2(OH)4]3·H2O and aqueous solutions of NpO2(2+) in 2.5 and 3.5 M (TMA)OH revealed bond lengths nearly identical with those determined by X-ray diffraction but with an increase in the number of equatorial ligands with increasing (TMA)OH concentration. Raman spectra of single crystals of [Co(NH3)6]2[NpO2(OH)4]3·H2O reveal a ν1(O═Np═O) symmetric stretch at 741 cm(-1). Raman spectra of NpO2(2+) recorded in a 0.6-2.2 M LiOH solution reveal a single ν1 frequency of 769 cm(-1). Facile exchange of the neptunyl oxo ligands with the water solvent was also observed with Raman spectroscopy performed with (16)O- and (18)O-enriched water solvent. The combination of EXAFS and Raman data suggests that NpO2(OH)4(2-) is the dominant solution species under the conditions of study and that a small amount of a second species, NpO2(OH)5(3-), may also be present at higher alkalinity. Crystal data for [Co(NH3)6]2[NpO2(OH)4]3·H2O: monoclinic, space group C2/c, a = 17.344(4) Å, b = 12.177(3) Å, c = 15.273 Å, β = 120.17(2)°, Z = 4, R1 = 0.0359, wR2 = 0.0729.

  18. Quantitative Proteomic Analysis of Germination of Nosema bombycis Spores under Extremely Alkaline Conditions.

    PubMed

    Liu, Han; Chen, Bosheng; Hu, Sirui; Liang, Xili; Lu, Xingmeng; Shao, Yongqi

    2016-01-01

    The microsporidian Nosema bombycis is an obligate intracellular pathogen of the silkworm Bombyx mori, causing the epidemic disease Pebrine and extensive economic losses in sericulture. Although N. bombycis forms spores with rigid spore walls that protect against various environmental pressures, ingested spores germinate immediately under the extremely alkaline host gut condition (Lepidoptera gut pH > 10.5), which is a key developmental turning point from dormant state to infected state. However, to date this process remains poorly understood due to the complexity of the animal digestive tract and the lack of genetic tools for microsporidia. Here we show, using an in vitro spore germination model, how the proteome of N. bombycis changes during germination, analyse specific metabolic pathways employed in detail, and validate key functional proteins in vivo in silkworms. By a label-free quantitative proteomics approach that is directly based on high-resolution mass spectrometry (MS) data, a total of 1136 proteins were identified with high confidence, with 127 proteins being significantly changed in comparison to non-germinated spores. Among them, structural proteins including polar tube protein 1 and 3 and spore wall protein (SWP) 4 and 30 were found to be significantly down-regulated, but SWP9 significantly up-regulated. Some nucleases like polynucleotide kinase/phosphatase and flap endonucleases 1, together with a panel of hydrolases involved in protein degradation and RNA cleavage were overrepresented too upon germination, which implied that they might play important roles during spore germination. The differentially regulated trends of these genes were validated, respectively, by quantitative RT-PCR and 3 proteins of interest were confirmed by Western blotting analyses in vitro and in vivo. Furthermore, the pathway analysis showed that abundant up- and down-regulations appear involved in the glycolysis, pentose phosphate pathway, purine, and pyrimidine metabolism

  19. Quantitative Proteomic Analysis of Germination of Nosema bombycis Spores under Extremely Alkaline Conditions

    PubMed Central

    Liu, Han; Chen, Bosheng; Hu, Sirui; Liang, Xili; Lu, Xingmeng; Shao, Yongqi

    2016-01-01

    The microsporidian Nosema bombycis is an obligate intracellular pathogen of the silkworm Bombyx mori, causing the epidemic disease Pebrine and extensive economic losses in sericulture. Although N. bombycis forms spores with rigid spore walls that protect against various environmental pressures, ingested spores germinate immediately under the extremely alkaline host gut condition (Lepidoptera gut pH > 10.5), which is a key developmental turning point from dormant state to infected state. However, to date this process remains poorly understood due to the complexity of the animal digestive tract and the lack of genetic tools for microsporidia. Here we show, using an in vitro spore germination model, how the proteome of N. bombycis changes during germination, analyse specific metabolic pathways employed in detail, and validate key functional proteins in vivo in silkworms. By a label-free quantitative proteomics approach that is directly based on high-resolution mass spectrometry (MS) data, a total of 1136 proteins were identified with high confidence, with 127 proteins being significantly changed in comparison to non-germinated spores. Among them, structural proteins including polar tube protein 1 and 3 and spore wall protein (SWP) 4 and 30 were found to be significantly down-regulated, but SWP9 significantly up-regulated. Some nucleases like polynucleotide kinase/phosphatase and flap endonucleases 1, together with a panel of hydrolases involved in protein degradation and RNA cleavage were overrepresented too upon germination, which implied that they might play important roles during spore germination. The differentially regulated trends of these genes were validated, respectively, by quantitative RT-PCR and 3 proteins of interest were confirmed by Western blotting analyses in vitro and in vivo. Furthermore, the pathway analysis showed that abundant up- and down-regulations appear involved in the glycolysis, pentose phosphate pathway, purine, and pyrimidine metabolism

  20. Anditalea andensis ANESC-ST - An Alkaliphilic Halotolerant Bacterium Capable of Electricity Generation under Alkaline-Saline Conditions

    PubMed Central

    Shi, Wei; Wang, Victor Bochuan; Zhao, Cui-E; Zhang, Qichun; Loo, Say Chye Joachim; Yang, Liang; Xu, Chenjie

    2015-01-01

    A great challenge in wastewater bioremediation is the sustained activity of viable microorganisms, which can contribute to the breakdown of waste contaminants, especially in alkaline pH conditions. Identification of extremophiles with bioremediation capability can improve the efficiency of wastewater treatment. Here, we report the discovery of an electrochemically active alkaliphilic halotolerant bacterium, Anditalea andensis ANESC-ST (=CICC10485T=NCCB 100412T), which is capable of generating bioelectricity in alkaline–saline conditions. A. andensis ANESC-ST was shown to grow in alkaline conditions between pH 7.0–11.0 and also under high salt condition (up to 4 wt% NaCl). Electrical output was further demonstrated in microbial fuel cells (MFCs) with an average current density of ~0.5 µA/cm2, even under the harsh condition of 4 wt% NaCl and pH 9.0. Subsequent introduction of secreted extracellular metabolites into MFCs inoculated with Escherichia coli or Pseudomonas aeruginosa yielded enhanced electrical output. The ability of A. andensis ANESC-ST to generate energy under alkaline–saline conditions points towards a solution for bioelectricity recovery from alkaline–saline wastewater. This is the first report of A.andensis ANESC-ST producing bioelectricity at high salt concentration and pH. PMID:26171779

  1. Enhancing Uranium Uptake by Amidoxime Adsorbent in Seawater: An investigation for optimum alkaline conditioning parameters

    SciTech Connect

    Das, S.; Tsouris, Constantinos; Zhang, C.; Kim, J.; Brown, S.; Oyola, Yatsandra; Janke, C.; Mayes, R. T.; Kuo, Li-Jung; Wood, Jordana R.; Gill, Gary A.; Dai, Sheng

    2016-04-20

    A high-surface-area polyethylene-fiber adsorbent (AF160-2) has been developed at the Oak Ridge National Laboratory (ORNL) by radiation-induced graft polymerization of acrylonitrile and itaconic acid. The grafted nitriles were converted to amidoxime groups by treating with hydroxylamine. The amidoximated adsorbents were then conditioned with potassium hydroxide (KOH) by varying different reaction parameters such as KOH concentration (0.2, 0.44, and 0.6 M), duration (1, 2, and 3 h), and temperature (60, 70, and 80 ºC). Adsorbent screening was then performed with simulated seawater solutions containing sodium chloride and sodium bicarbonate, at concentrations found in seawater, and uranium nitrate at a uranium concentration of ~ 7-8 ppm and pH 8. FTIR and solid state NMR indicated that a fraction of amidoxime groups was hydrolyzed to carboxylate during KOH conditioning. The uranium adsorption capacity in the simulated seawater screening solution gradually increased with conditioning time and temperature for all KOH concentrations. It was also observed that the adsorption capacity increased with an increase in concentration of KOH for all the conditioning times and temperatures. AF160-2 adsorbent samples were also tested with natural seawater using flow-through experiments to determine uranium adsorption capacity with varying KOH conditioning time and temperature. Based on uranium loading capacity values of several AF160-2 samples, it was observed that changing KOH conditioning time from 3 to 1 h at 60, 70, and 80 ºC resulted in increase of the uranium loading capacity in seawater, which did not follow the trend found in laboratory screening with stimulated solutions. Longer KOH conditioning times lead to significantly higher uptake of divalent metal ions, such as calcium and magnesium, which is a result of amidoxime conversion into less selective carboxylate. Scanning electron microscopy showed that long conditioning times may also lead to adsorbent degradation

  2. Enhancing uranium uptake by amidoxime adsorbent in seawater: An investigation for optimum alkaline conditioning parameters

    DOE PAGES

    Das, Sadananda; Tsouris, Costas; Zhang, Chenxi; ...

    2015-09-07

    A high-surface-area polyethylene-fiber adsorbent (AF160-2) has been developed at the Oak Ridge National Laboratory by radiation-induced graft polymerization of acrylonitrile and itaconic acid. The grafted nitriles were converted to amidoxime groups by treating with hydroxylamine. The amidoximated adsorbents were then conditioned with potassium hydroxide (KOH) by varying different reaction parameters such as KOH concentration (0.2, 0.44, and 0.6 M), duration (1, 2, and 3 h), and temperature (60, 70, and 80 °C). Adsorbent screening was then performed with simulated seawater solutions containing sodium chloride and sodium bicarbonate, at concentrations found in seawater, and uranium nitrate at a uranium concentration ofmore » ~7–8 ppm and pH 8. Fourier transform infrared spectroscopy and solid-state NMR analyses indicated that a fraction of amidoxime groups was hydrolyzed to carboxylate during KOH conditioning. The uranium adsorption capacity in the simulated seawater screening solution gradually increased with conditioning time and temperature for all KOH concentrations. It was also observed that the adsorption capacity increased with an increase in concentration of KOH for all the conditioning times and temperatures. AF160-2 adsorbent samples were also tested with natural seawater using flow-through experiments to determine uranium adsorption capacity with varying KOH conditioning time and temperature. Based on uranium loading capacity values of several AF160-2 samples, it was observed that changing KOH conditioning time from 3 to 1 h at 60, 70, and 80 °C resulted in an increase of the uranium loading capacity in seawater, which did not follow the trend found in laboratory screening with stimulated solutions. Longer KOH conditioning times lead to significantly higher uptake of divalent metal ions, such as calcium and magnesium, which is a result of amidoxime conversion into less selective carboxylate. The scanning electron microscopy showed that long

  3. Enhancing uranium uptake by amidoxime adsorbent in seawater: An investigation for optimum alkaline conditioning parameters

    SciTech Connect

    Das, Sadananda; Tsouris, Costas; Zhang, Chenxi; Brown, Suree; Janke, Christopher James; Mayes, Richard T.; Kuo, Li -Jung; Gill, Gary; Dai, Sheng; Kim, J.; Oyola, Y.; Wood, J. R.

    2015-09-07

    A high-surface-area polyethylene-fiber adsorbent (AF160-2) has been developed at the Oak Ridge National Laboratory by radiation-induced graft polymerization of acrylonitrile and itaconic acid. The grafted nitriles were converted to amidoxime groups by treating with hydroxylamine. The amidoximated adsorbents were then conditioned with potassium hydroxide (KOH) by varying different reaction parameters such as KOH concentration (0.2, 0.44, and 0.6 M), duration (1, 2, and 3 h), and temperature (60, 70, and 80 °C). Adsorbent screening was then performed with simulated seawater solutions containing sodium chloride and sodium bicarbonate, at concentrations found in seawater, and uranium nitrate at a uranium concentration of ~7–8 ppm and pH 8. Fourier transform infrared spectroscopy and solid-state NMR analyses indicated that a fraction of amidoxime groups was hydrolyzed to carboxylate during KOH conditioning. The uranium adsorption capacity in the simulated seawater screening solution gradually increased with conditioning time and temperature for all KOH concentrations. It was also observed that the adsorption capacity increased with an increase in concentration of KOH for all the conditioning times and temperatures. AF160-2 adsorbent samples were also tested with natural seawater using flow-through experiments to determine uranium adsorption capacity with varying KOH conditioning time and temperature. Based on uranium loading capacity values of several AF160-2 samples, it was observed that changing KOH conditioning time from 3 to 1 h at 60, 70, and 80 °C resulted in an increase of the uranium loading capacity in seawater, which did not follow the trend found in laboratory screening with stimulated solutions. Longer KOH conditioning times lead to significantly higher uptake of divalent metal ions, such as calcium and magnesium, which is a result of amidoxime conversion into less selective carboxylate. The scanning electron microscopy showed that long conditioning

  4. Biodegradation of cyanide by a new isolated strain under alkaline conditions and optimization by response surface methodology (RSM)

    PubMed Central

    2014-01-01

    Background Biodegradation of free cyanide from industrial wastewaters has been proven as a viable and robust method for treatment of wastewaters containing cyanide. Results Cyanide degrading bacteria were isolated from a wastewater treatment plant for coke-oven-gas condensate by enrichment culture technique. Five strains were able to use cyanide as the sole nitrogen source under alkaline conditions and among them; one strain (C2) was selected for further studies on the basis of the higher efficiency of cyanide degradation. The bacterium was able to tolerate free cyanide at concentrations of up to 500 ppm which makes it a good potentially candidate for the biological treatment of cyanide contaminated residues. Cyanide degradation corresponded with growth and reached a maximum level 96% during the exponential phase. The highest growth rate (1.23 × 108) was obtained on day 4 of the incubation time. Both glucose and fructose were suitable carbon sources for cyanotrophic growth. No growth was detected in media with cyanide as the sole carbon source. Four control factors including, pH, temperature, agitation speed and glucose concentration were optimized according to central composite design in response surface method. Cyanide degradation was optimum at 34.2°C, pH 10.3 and glucose concentration 0.44 (g/l). Conclusions Bacterial species degrade cyanide into less toxic products as they are able to use the cyanide as a nitrogen source, forming ammonia and carbon dioxide as end products. Alkaliphilic bacterial strains screened in this study evidentially showed the potential to possess degradative activities that can be harnessed to remediate cyanide wastes. PMID:24921051

  5. Arsenic in an Alkaline AMD Treatment Sludge: Characterization and Stability Under Prolonged Anoxic Conditions

    SciTech Connect

    Beauchemin, S.; Fiset, J; Poirier, G; Ablett, J

    2010-01-01

    Lime treatment of acid mine drainage (AMD) generates large volumes of neutralization sludge that are often stored under water covers. The sludge consists mainly of calcite, gypsum and a widespread ferrihydrite-like Fe phase with several associated species of metal(loid) contaminants. The long-term stability of metal(loid)s in this chemically ill-defined material remains unknown. In this study, the stability and speciation of As in AMD sludge subjected to prolonged anoxic conditions is determined. The total As concentration in the sludge is 300 mg kg{sup -1}. In the laboratory, three distinct water cover treatments were imposed on the sludge to induce different redox conditions (100%N{sub 2}, 100%N{sub 2} + glucose, 95%N{sub 2}:5%H{sub 2}). These treatments were compared against a control of oxidized, water-saturated sludge. Electron micro-probe (EMP) analysis and spatially resolved synchrotron X-ray fluorescence (SXRF) results indicate that As is dominantly associated with Fe in the sludge. In all treatments and throughout the experiment, measured concentrations of dissolved As were less than 5 {micro}g L{sup -1}. Dissolved Mn concentration in the N{sub 2} + glucose treatment increased significantly compared to other treatments. Manganese and As K-edge X-ray absorption near edge structure spectroscopy (XANES) analyses showed that Mn was the redox-active element in the solid-phase, while As was stable. Arsenic(V) was still the dominant species in all water-covered sludges after 9 months of anoxic treatments. In contrast, Mn(IV) in the original sludge was partially reduced into Mn(II) in all water-covered sludges. The effect was most pronounced in the N{sub 2} + glucose treatment, suggesting microbial reduction. Micro-scale SXRF and XANES analysis of the treated sludge showed that Mn(II) accumulated in areas already enriched in Fe and As. Overall, the study shows that AMD sludges remain stable under prolonged anoxic conditions. External sources of chemical reductants

  6. Modeling experimental results of diffusion of alkaline solutions through a compacted bentonite barrier

    SciTech Connect

    Fernandez, Raul; Cuevas, Jaime; Maeder, Urs K.

    2010-08-15

    The interaction between concrete/cement and swelling clay (bentonite) has been modeled in the context of engineered barrier systems for deep geological disposal of high-level radioactive waste. The geochemical transformations observed in laboratory diffusion experiments at 60 and 90 {sup o}C between bentonite and different high-pH solutions (K-Na-OH and Ca(OH){sub 2}-saturated) were reconciled with the reactive transport code CrunchFlow. For K-Na-OH solutions (pH = 13.5 at 25 {sup o}C) partial dissolution of montmorillonite and precipitation of Mg-silicates (talc-like), hydrotalcite and brucite at the interface are predicted at 60 {sup o}C, while at 90 {sup o}C the alteration is wider. Alkaline cations diffused beyond the mineralogical alteration zone by means of exchange with Mg{sup 2+} in the interlayer region of montmorillonite. Very slow reactivity and minor alteration of the clay are predicted in the Ca(OH){sub 2}-bentonite system. The model is a reasonable description of the experiments but also demonstrates the difficulties in modeling processes operating at a small scale under a diffusive regime.

  7. Effect of different carbon sources on decolourisation of an industrial textile dye under alkaline-saline conditions.

    PubMed

    Ottoni, Cristiane; Lima, Luis; Santos, Cledir; Lima, Nelson

    2014-01-01

    White-rot fungal strains of Trametes versicolor and Phanerochaete chrysosporium were selected to study the decolourisation of the textile dye, Reactive Black 5, under alkaline-saline conditions. Free and immobilised T. versicolor cells showed 100 % decolourisation in the growth medium supplemented with 15 g l(-1) NaCl, pH 9.5 at 30 °C in liquid batch culture. Continuous culture experiments were performed in a fixed-bed reactor using free and immobilised T. versicolor cells and allowed 85-100 % dye decolourisation. The immobilisation conditions for the biomass and the additional supply of carbon sources improved the decolourisation performance during a long-term trial of 40 days. Lignin peroxidase, laccase and glyoxal oxidase activities were detected during the experiments. The laccase activity varied depending on carbon source utilized and glycerol-enhanced laccase activity compared to sucrose during extended growth.

  8. Multi-technique approach for qualitative and quantitative characterization of furazidin degradation kinetics under alkaline conditions.

    PubMed

    Bērziņš, Kārlis; Kons, Artis; Grante, Ilze; Dzabijeva, Diana; Nakurte, Ilva; Actiņš, Andris

    2016-09-10

    Degradation of drug furazidin was studied under different conditions of environmental pH (11-13) and temperature (30-60°C). The novel approach of hybrid hard- and soft-multivariate curve resolution-alternating least squares (HS-MCR-ALS) method was applied to UV-vis spectral data to determine a valid kinetic model and kinetic parameters of the degradation process. The system was found to be comprised of three main species and best characterized by two consecutive first-order reactions. Furazidin degradation rate was found to be highly dependent on the applied environmental conditions, showing more prominent differences between both degradation steps towards higher pH and temperature. Complimentary qualitative analysis of the degradation process was carried out using HPLC-DAD-TOF-MS. Based on the obtained chromatographic and mass spectrometric results, as well as additional computational analysis of the species (theoretical UV-vis spectra calculations utilizing TD-DFT methodology), the operating degradation mechanism was proposed to include formation of a 5-hydroxyfuran derivative, followed by complete hydrolysis of furazidin hydantoin ring.

  9. Structural analysis of alkaline β-mannanase from alkaliphilic Bacillus sp. N16-5: implications for adaptation to alkaline conditions.

    PubMed

    Zhao, Yueju; Zhang, Yunhua; Cao, Yang; Qi, Jianxun; Mao, Liangwei; Xue, Yanfen; Gao, Feng; Peng, Hao; Wang, Xiaowei; Gao, George F; Ma, Yanhe

    2011-01-28

    Significant progress has been made in isolating novel alkaline β-mannanases, however, there is a paucity of information concerning the structural basis for alkaline tolerance displayed by these β-mannanases. We report the catalytic domain structure of an industrially important β-mannanase from the alkaliphilic Bacillus sp. N16-5 (BSP165 MAN) at a resolution of 1.6 Å. This enzyme, classified into subfamily 8 in glycosyl hydrolase family 5 (GH5), has a pH optimum of enzymatic activity at pH 9.5 and folds into a classic (β/α)(8)-barrel. In order to gain insight into molecular features for alkaline adaptation, we compared BSP165 MAN with previously reported GH5 β-mannanases. It was revealed that BSP165 MAN and other subfamily 8 β-mannanases have significantly increased hydrophobic and Arg residues content and decreased polar residues, comparing to β-mannanases of subfamily 7 or 10 in GH5 which display optimum activities at lower pH. Further, extensive structural comparisons show alkaline β-mannanases possess a set of distinctive features. Position and length of some helices, strands and loops of the TIM barrel structures are changed, which contributes, to a certain degree, to the distinctly different shaped (β/α)(8)-barrels, thus affecting the catalytic environment of these enzymes. The number of negatively charged residues is increased on the molecular surface, and fewer polar residues are exposed to the solvent. Two amino acid substitutions in the vicinity of the acid/base catalyst were proposed to be possibly responsible for the variation in pH optimum of these homologous enzymes in subfamily 8 of GH5, identified by sequence homology analysis and pK(a) calculations of the active site residues. Mutational analysis has proved that Gln91 and Glu226 are important for BSP165 MAN to function at high pH. These findings are proposed to be possible factors implicated in the alkaline adaptation of GH5 β-mannanases and will help to further understanding of

  10. Effect of three cations on the stability and microstructure of protein aggregate from duck egg white under alkaline condition.

    PubMed

    Ganasen, P; Benjakul, S

    2011-08-01

    Pidan (alkaline egg) has been consumed widely in oriental countries and lead, a toxic element, has been used traditionally to yield the desirable characteristics. For safety concerns, alternative cations can be used for the production of pidan with comparable properties to traditionally prepared pidan. Turbidity measured as absorbance at 400 nm and microstructure of duck egg white proteins at pH 12 as influenced by three cations at various levels were investigated. Turbidity and particle size of egg white protein (20 g/kg) in 10 g/kg NaCl sample with CaCl2, PbO2 or ZnCl2 added at a level of 1 g/kg increased with time up to 1 h, followed by a decrease (p<0.05). Nevertheless, the turbidity was retained more in samples added with PbO2, suggesting high stability of the aggregate formed. Zeta potential showed that the aggregates treated with PbO2 had a comparatively lower negative charge. Light microscopic studies indicated that the aggregation of egg white proteins was induced by ions but varied with the types of ions and incubation time. Therefore, PbO2 exhibited the highest stabilizing effect on egg white protein under alkaline condition. However, ZnCl2 can be used as an alternative compound even if it had lower impact on stability of aggregate of duck egg white protein.

  11. A New Mechanism in Electrochemical Process for Arsenic Oxidation: Production of H2O2 from Anodic O2 Reduction on the Cathode under Automatically Developed Alkaline Conditions.

    PubMed

    Qian, Ao; Yuan, Songhu; Zhang, Peng; Tong, Man

    2015-05-05

    Electrochemical cathodes are often used to reduce contaminants or produce oxidizing substances (i.e., H2O2). Alkaline conditions develop automatically around the cathode in electrochemical processes, and O2 diffuses onto the cathode easily. However, limited attention is paid to contaminant transformation by the reactive species produced on the cathode under oxic and alkaline conditions due to the inapplicability of pH for Fenton reaction. In this study, a new oxidation mechanism on the cathode is presented for contaminant transformation under automatically developed alkaline conditions. In an electrochemical sand column, 6.67 μM As(III) was oxidized by 36% when it passed through the cathode under the conditions of 30 mA current, an initial pH of 7.5 and a flow rate of 2 mL/min. Under the alkaline conditions (pH 10.0-11.0) that developed automatically around the cathode, the reduction potential of As(III) decreased greatly, allowing a pronounced oxidation by the small quantities of H2O2 produced from O2 reduction on the cathode. As(III) oxidation was further increased by the presence of soil pore water and groundwater solutes of HCO3-, Ca2+, Mg2+ and humic acid. The new oxidation mechanism found for the cathode under localized alkaline conditions supplements the fundamentals of contaminant transformation in electrochemical processes.

  12. Dissolution Kinetics of Meta-Torbernite under Circum-neutral to Alkaline Conditions

    SciTech Connect

    Wellman, Dawn M.; McNamara, Bruce K.; Bacon, Diana H.; Cordova, Elsa A.; Ermi, Ruby M.; Top, Laken M.

    2009-12-21

    Autunite group minerals have been identified in contaminated sediments as the long-term controlling phase of uranium. Meta-torbernite, has been identified in subsurface environments which were subjected to co-contaminant disposal practices from past nuclear weapons and fuel operations. Under these conditions the mobility of uranium in subsurface pore waters is limited by the rate of meta-torbernite dissolution; however, there are no known investigations which report the dissolution behavior of meta-torbernite. The purpose of this investigation was to conduct a series of single-pass flow-through (SPFT) tests to 1) quantify the effect of temperature (23 - 90oC) and pH (6 -10) on meta-torbernite dissolution, 2) compare the dissolution of meta-torbernite to other autunite-group minerals, and 3) evaluate the effect of aqueous phosphate on the dissolution kinetics of meta-torbernite. Results presented here illustrate meta-torbernite dissolution rates increase by ~100X over the pH interval of 6 to 10 (eta = 0.59 ± 0.07), irrespective of temperature. The power law coefficient for meta-torbernite, eta = 0.59 ± 0.07, is greater than that quantified for Ca-meta-autunite, eta = 0.42 ± 0.12. This suggests the stability of meta-torbernite is greater than that of meta-autunite, which is reflected in the predicted stability constants. The rate equation for the dissolution of meta-torbernite as a function of aqueous phosphate concentration is log rdissol (mol m-2 sec-1) = -4.7 x 10-13 + 4.1 x 10-10 [PO43-].

  13. Optimizing operating conditions and electrochemical characterization of glucose-gluconate alkaline fuel cells

    NASA Astrophysics Data System (ADS)

    Pasta, M.; La Mantia, F.; Ruffo, R.; Peri, F.; Pina, C. Della; Mari, C. M.

    The direct oxidation of glucose to produce electrical energy has been widely investigated because of renewability, abundance, high energy density and easy handling of the carbohydrate. Most of the previous studies have been conducted in extreme conditions in order to achieve complete glucose oxidation to CO 2, neglecting the carbohydrate chemical instability that generally leads to useless by-products mixtures. The partial oxidation to gluconate, originally studied for implantable fuel cells, has the advantage of generating a commercially valuable chemical. In the present paper we optimized fuel composition and operating conditions in order to selectively oxidize glucose to gluconate, maximizing the power density output of a standard commercial platinum based anode material. A deep electrochemical characterization concerning reversible potential, cyclic voltammetry and overpotential measurements have been carried out at 25 °C in the D-(+)-glucose concentration range 1.0 × 10 -2 to 1.0 M. NMR and EIS investigation clarify the role of the buffer in enhancing the electrochemical performance.

  14. Hydrolysis of Indole-3-Acetic Acid Esters Exposed to Mild Alkaline Conditions 1

    PubMed Central

    Baldi, Bruce G.; Maher, Barbara R.; Cohen, Jerry D.

    1989-01-01

    Ester conjugates of indole-3-acetic acid are hydrolyzed easily in basic solutions; however, quantitative data have not been available on the relationship between pH and rate of hydrolysis of the known ester conjugates. The use of basic conditions during extraction or purification of IAA by several laboratories suggested that a more systematic analysis of this process was needed. In this report we present data indicating: (a) that measurable hydrolysis of IAA-glucose (from standard solutions) and IAA-esters (from maize kernel extracts) occurs with only a few hours of treatment at pH 9 or above; (b) that the lability of some ester conjugates is even greater than that of IAA-glucose; and (c) that ester hydrolysis of standard compounds, IAA-glucose and IAA-p-nitrophenol, occurs in the `three phase extraction system' proposed by Liu and Tillberg ([1983] Physiol Plant 57: 441-447). These data indicate that the potential for problems with inadvertent hydrolysis of ester conjugates of IAA exists even at moderate pH values and in the multiphase system where exposure to basic conditions was thought to be limited. PMID:16667049

  15. Growth of oil accumulating microalga Neochloris oleoabundans under alkaline-saline conditions.

    PubMed

    Santos, A M; Janssen, M; Lamers, P P; Evers, W A C; Wijffels, R H

    2012-01-01

    The effect of elevated pH and salt concentration on the growth of the freshwater microalga Neochloris oleoabundans was investigated. A study was conducted in 24-well plates on the design of a growth medium and subsequently applied in a photobioreactor. An artificial seawater medium with reduced Ca(2+) and PO(4)(3-) could prevent mineral precipitation at high pH levels. Growth was characterized in this new medium at pH 8.1 and at pH 10.0, with 420 mM of total salts. Specific growth rates of 0.08 h(-1) at pH 8.1 and 0.04 h(-1) at pH 10.0 were obtained under controlled turbidostat cultivation. The effect of nitrogen starvation on lipid accumulation was also investigated. Fatty acids content increased not only with nitrogen limitation but also with a pH increase (up to 35% in the dry biomass). Fluorescence microscopy gave visual proof that N. oleoabundans accumulates oil bodies when growing in saline conditions at high pH.

  16. Comprehensive study of the chemical reactions resulting from the decomposition of chloroform in alkaline aqueous solution

    NASA Astrophysics Data System (ADS)

    Estevez Mews, Jorge

    Chloroform (CHCl3) is a volatile liquid, which has a rather slow rate of decomposition in ground water. It is a known carcinogen and one of the most common contaminants found at toxic waste sites. The dominant degradation process for chloroform in both the atmosphere and the groundwater is the reaction with the hydroxyl radical or hydroxide ion. This process triggers a sequence of reactions which ultimately yield carbon monoxide, hydrogen chloride, and formic acid. The rate of chloroform degradation is considerably larger in solution than that in the gas phase and it increases dramatically with increasing pH. However, only one of the viable reactions had been studied previously at a high level of theory in solution. It is of great interest to gain a deeper understanding of the decomposition reaction mechanism. Quantum mechanical methods are well suited for studying the mechanism of organic reactions. However, a full quantum mechanical treatment of the entire fluid system is not computationally feasible. In this work, combined quantum mechanical and molecular mechanical (QM/MM) methods are used for studying chemical reactions in condensed phases. In these calculations, the solute molecules are treated quantum mechanically (QM), whereas the solvent molecules are approximated by empirical (MM) potential energy functions. The use of quantum mechanics and statistical sampling simulation is necessary to determine the reaction free energy profile. In the present study, the ab initio Hartree-Fock theory along with the 3-21G basis set was used in the quantum mechanical calculations to elucidate the reaction pathways of chloroform decomposition, with a focus on basic reaction conditions. Statistical mechanical Monte Carlo approach was then applied in molecular mechanical simulations, employing the empirical TIP3P model for water. We employed state-of-the-art electronic structure methods to determine the gas-phase inter-nuclear potential energy profile for all the relevant

  17. Catalytic wet oxidation of o-chlorophenol at mild temperatures under alkaline conditions.

    PubMed

    Kojima, Yoshihiro; Fukuta, Tadashi; Yamada, Takehisa; Onyango, Maurice S; Bernardo, Eileen C; Matsuda, Hitoki; Yagishita, Kohichi

    2005-01-01

    Wet oxidation of a 100 ppm aqueous solution of o-chlorophenol (o-CP) was performed in a lab-scale batch reactor using 3% Ru/TiO(2) catalyst at 373 and 413 K, and a partial oxygen pressure of 0.1 MPa. The experiments were conducted by varying the initial pH values of o-CP solution from pH 6.3 to 9.8 and 11.8. From the results, it was revealed that the catalytic decomposition of o-CP occurred most effectively at 413 K and at the initial pH of 9.8. Complete decomposition and dechlorination of o-CP were almost achieved within 1h, and about 85% of TOC was removed in 3.0 h. On the other hand, the catalytic wet oxidation of o-CP at a higher pH value of 11.8 was not effective in the removal of TOC. The incomplete removal of TOC at the initial pH of 11.8 is likely attributed to a low pK(a) of carboxylic acids formed during the wet oxidation of o-CP.

  18. Whiteness improvement of citric acid crosslinked cotton fabrics: H2O2 bleaching under alkaline condition.

    PubMed

    Tang, Peixin; Ji, Bolin; Sun, Gang

    2016-08-20

    Polycarboxylic acids have been employed as formaldehyde-free crosslinking agents in anti-wrinkle treatment for cotton fabrics. Cotton fabrics treated by citric acid (CA) catalyzed with effective catalysts have shown satisfactory anti-wrinkle properties. Meanwhile, CA is a natural-based and environmental friendly compound. However, the yellowing of CA treated fabrics is a stumbling block for its practical application. Due to the fact that CA firstly forms aconitic acid (AA) before forming anhydrides, the cause of the yellowing, hydrogen peroxide (H2O2) bleaching was adopted to treat the CA treated fabrics in order to break the CC bond structure and reduce the yellow color but retaining the desired anti-wrinkle properties. Thermogravimetric analysis and Fourier transformed infrared spectroscopy were employed to investigate the reactions. The results revealed that the H2O2 bleaching can effectively improve the whiteness and also maintain a good anti-wrinkle performance of the CA treated fabrics under an appropriate bleaching temperature and time.

  19. Free energy distribution and hydrothermal mineral precipitation in Hadean submarine alkaline vent systems: Importance of iron redox reactions under anoxic conditions

    NASA Astrophysics Data System (ADS)

    Shibuya, Takazo; Russell, Michael J.; Takai, Ken

    2016-02-01

    Thermodynamic calculations of mixing between hypothetical seawater and hydrothermal fluid in the Hadean deep ocean were carried out to predict saturation states of mineral precipitates and redox reactions that could occur in Hadean submarine alkaline hydrothermal systems associated with the serpentinization of ultramafic rocks. In the calculations, the seawater was assumed to be weakly acidic (pH = 5.5) and to include carbon dioxide, ferrous iron and silica, with or without nitrate, while the Hadean hydrothermal fluid was assumed to be highly alkaline (pH = 11) and to contain abundant molecular hydrogen, methane and bisulfide, based on the Archean geologic record, the modern low-temperature alkaline hydrothermal vent fluid (Lost City field), and experimental and theoretical considerations. The modeling indicates that potential mineral precipitates in the mixing zone (hydrothermal chimney structures) could consist mainly of iron sulfides but also of ferrous serpentine and brucite, siderite, and ferric iron-bearing minerals such as goethite, hematite and/or magnetite as minor phases. The precipitation of ferric iron-bearing minerals suggests that chemical iron oxidation would be made possible by pH shift even under anoxic condition. In the mixing zone, comprising an inorganic barrier precipitated at the interface of the two contrasting solutions, various redox reactions release free energy with the potential to drive endergonic reactions, assuming the involvement of coupling inorganic protoenzymes. Hydrogenotrophic methanogenesis and acetogenesis - long considered the most ancient forms of biological energy metabolisms - are able to achieve higher maximum energy yield (>0.5 kJ/kg hydrothermal fluid) than those in the modern serpentinization-associated seafloor hydrothermal systems (e.g., Kairei field). Furthermore, the recently proposed methanotrophic acetogenesis pathway was also thermodynamically investigated. It is known that methanotrophic acetogenesis would

  20. Alkaline Ceramidase 3 Deficiency Results in Purkinje Cell Degeneration and Cerebellar Ataxia Due to Dyshomeostasis of Sphingolipids in the Brain

    PubMed Central

    Preston, Chet; Wang, Louis; Yi, Jae Kyo; Lin, Chih-Li; Sun, Wei; Spyropoulos, Demetri D.; Rhee, Soyoung; Li, Mingsong; Zhou, Jie; Ge, Shaoyu; Zhang, Guofeng; Snider, Ashley J.; Hannun, Yusuf A.; Obeid, Lina M.; Mao, Cungui

    2015-01-01

    Dyshomeostasis of both ceramides and sphingosine-1-phosphate (S1P) in the brain has been implicated in aging-associated neurodegenerative disorders in humans. However, mechanisms that maintain the homeostasis of these bioactive sphingolipids in the brain remain unclear. Mouse alkaline ceramidase 3 (Acer3), which preferentially catalyzes the hydrolysis of C18:1-ceramide, a major unsaturated long-chain ceramide species in the brain, is upregulated with age in the mouse brain. Acer3 knockout causes an age-dependent accumulation of various ceramides and C18:1-monohexosylceramide and abolishes the age-related increase in the levels of sphingosine and S1P in the brain; thereby resulting in Purkinje cell degeneration in the cerebellum and deficits in motor coordination and balance. Our results indicate that Acer3 plays critically protective roles in controlling the homeostasis of various sphingolipids, including ceramides, sphingosine, S1P, and certain complex sphingolipids in the brain and protects Purkinje cells from premature degeneration. PMID:26474409

  1. A multi-scale model of the oxygen reduction reaction on highly active graphene nanosheets in alkaline conditions

    NASA Astrophysics Data System (ADS)

    Vazquez-Arenas, Jorge; Ramos-Sanchez, Guadalupe; Franco, Alejandro A.

    2016-10-01

    A multi-scale model based on a mean field approach, is proposed to describe the ORR mechanism on N-GN catalysts in alkaline media. The model implements activation energies calculated with Density Functional Theory (DFT) at the atomistic level, and scales up them into a continuum framework describing the cathode/electrolyte interface at the mesoscale level. The model also considers mass and momentum transports arising in the region next to the rotating electrode for all ionic species and O2; correction of potential drop and electrochemical double-layer capacitance. Most fitted parameters describing the kinetics of ORR elementary reactions are sensitive in the multi-scale model, which results from the incorporation of activation energies using the mean field method, unlike single-scale modelling Errors in the deviations from activation energies are found to be moderate, except for the elementary step (2) related to the formation of O2ads, which can be assigned to the inherent DFT limitations. The consumption of O2ads to form OOHads is determined as the rate-determining step as a result of its highest energy barrier (163.10 kJ mol-1) in the system, the largest error obtained for the deviation from activation energy (28.15%), and high sensitivity. This finding is confirmed with the calculated surface concentration and coverage of electroactive species.

  2. DEVELOPMENT OF AN IMPROVED TITANATE-BASED SORBENT FOR STRONTIUM AND ACTINIDE SEPARATIONS UNDER STRONGLY ALKALINE CONDITIONS

    SciTech Connect

    Hobbs, D.; Peters, T.; Taylor-Pashow, K.; Fink, S.

    2010-02-18

    High-level nuclear waste produced from fuel reprocessing operations at the Savannah River Site (SRS) requires pretreatment to remove {sup 134,137}Cs, {sup 90}Sr, and alpha-emitting radionuclides (i.e., actinides) prior to disposal onsite as low level waste. Separation processes at SRS include the sorption of {sup 90}Sr and alpha-emitting radionuclides onto monosodium titanate (MST) and caustic side solvent extraction of {sup 137}Cs. The MST and separated {sup 137}Cs is encapsulated along with the sludge fraction of high-level waste (HLW) into a borosilicate glass waste form for eventual entombment at a federal repository. The predominant alpha-emitting radionuclides in the highly alkaline waste solutions include plutonium isotopes {sup 238}Pu, {sup 239}Pu, and {sup 240}Pu; {sup 237}Np; and uranium isotopes, {sup 235}U and {sup 238}U. This paper describes recent results evaluating the performance of an improved sodium titanate material that exhibits increased removal kinetics and capacity for {sup 90}Sr and alpha-emitting radionuclides compared to the current baseline material, MST.

  3. Amperometric nitric oxide sensors with enhanced selectivity over carbon monoxide via platinum oxide formation under alkaline conditions.

    PubMed

    Jensen, Gary C; Zheng, Zheng; Meyerhoff, Mark E

    2013-11-05

    An improved planar amperometric nitric oxide (NO) sensor with enhanced selectivity over carbon monoxide (CO), which represents a volatile interfering species for NO sensors that has been largely overlooked until recently, is described. Formation of an oxide film on the inner platinum working electrode via anodic polarization using an inner alkaline electrolyte solution provides the basis for improved selectivity. Cyclic voltammetry reveals that formation of an oxidized Pt film inhibits adsorption of CO to the electrode surface, which is a necessary initial step in the electrocatalytic oxidation of CO on Pt. Previous NO gas sensors that employ internal electrolyte solutions have been assembled using acidic internal solutions that inhibit the formation of a dense platinum oxide film on the working electrode surface. It is demonstrated herein that increasing the internal electrolyte pH promotes oxidized platinum film formation, resulting in improved selectivity over CO. Selectivity coefficients (log KNO,j) for sensors assembled with internal solutions at various pH values range from -0.08 at pH 2.0 to -2.06 at pH 11.7, with average NO sensitivities of 1.24 nA/μM and a limit of detection (LOD) of <1 nM.

  4. On the influence of reaction conditions in activity determination of alkaline phosphatase on the molar absorptivity of 4-nitrophenol.

    PubMed

    Jung, K; Köhler, A

    1980-02-14

    In activity determination of alkaline phosphatase (AP), measuring temperature, type and concentration of buffer, and protein concentration in the test influence the molar absorptivity of 4-nitrophenol. Thus systematic errors of up to 3% may occur in activity determinations of AP if these influences are not taken into account.

  5. Additional Results of Glaze Icing Scaling in SLD Conditions

    NASA Technical Reports Server (NTRS)

    Tsao, Jen-Ching

    2016-01-01

    This presentation reports results from recent icing scaling tests in NASA Glenn Icing Research Tunnel (IRT) to evaluate how well the scaling method recommended for Appendix C conditions might apply to SLD conditions.

  6. Alkaline battery operational methodology

    DOEpatents

    Sholklapper, Tal; Gallaway, Joshua; Steingart, Daniel; Ingale, Nilesh; Nyce, Michael

    2016-08-16

    Methods of using specific operational charge and discharge parameters to extend the life of alkaline batteries are disclosed. The methods can be used with any commercial primary or secondary alkaline battery, as well as with newer alkaline battery designs, including batteries with flowing electrolyte. The methods include cycling batteries within a narrow operating voltage window, with minimum and maximum cut-off voltages that are set based on battery characteristics and environmental conditions. The narrow voltage window decreases available capacity but allows the batteries to be cycled for hundreds or thousands of times.

  7. Preparation in Acidic and Alkaline Conditions and Characterization of α-Bi2Mo3O12 and γ-Bi2MoO6 Powders

    NASA Astrophysics Data System (ADS)

    Chen, Tao; Wang, Mao-Hua; Ma, Xiao-Yu

    2016-08-01

    α-Bi2Mo3O12 and γ-Bi2MoO6 powders have been successfully fabricated via a sol-gel method starting from bismuth nitrate and ammonium molybdate. The as-synthesized samples were characterized by x-ray powder diffraction analysis, thermogravimetry and differential thermogravimetry, scanning electron microscopy, and ultraviolet-visible (UV-Vis) absorption spectroscopy. The results indicated the formation of α-Bi2Mo3O12 and γ-Bi2MoO6 powders in acidic (pH 5) and alkaline (pH 9) conditions, respectively. α-Bi2Mo3O12 exhibited irregular shape, while γ-Bi2MoO6 showed approximately flake-like morphology. The bandgap of pure α-Bi2Mo3O12 and γ-Bi2MoO6 was estimated to be about 2.83 eV and 2.85 eV, respectively, according to UV-Vis studies. The slight shift of the absorption edge towards longer wavelength for α-Bi2Mo3O12 indicated a decrease of the optical bandgap. Photocatalytic experiments showed that γ-Bi2MoO6 exhibited higher photodegradation activity of methylene blue compared with α-Bi2Mo3O12.

  8. The effect of Si and Al concentrations on the removal of U(VI) in the alkaline conditions created by NH3 gas

    SciTech Connect

    Katsenovich, Yelena P.; Cardona, Claudia; Lapierre, Robert; Szecsody, Jim; Lagos, Leonel E.

    2016-10-01

    Remediation of uranium in the deep unsaturated zone is a challenging task, especially in the presence of oxygenated, high-carbonate alkalinity soil and pore water composition typical for arid and semi-arid environments of the western regions of the U.S. This study evaluates the effect of various pore water constituencies on changes of uranium concentrations in alkaline conditions, created in the presence of reactive gases such as NH3 to effectively mitigate uranium contamination in the vadose zone sediments. This contaminant is a potential source for groundwater pollution through slow infiltration of soluble and highly mobile uranium species towards the water table. The objective of this research was to evaluate uranium sequestration efficiencies in the alkaline synthetic pore water solutions prepared in a broad range of Si, Al, and bicarbonate concentrations typically present in field systems of the western U.S. regions and identify solid uranium-bearing phases that result from ammonia gas treatment. In previous studies (Szecsody et al. 2012; Zhong et al. 2015), although uranium mobility was greatly decreased, solid phases could not be identified at the low uranium concentrations in field-contaminated sediments. The chemical composition of the synthetic pore water used in the experiments varied for silica (5–250 mM), Al3+ (2.8 or 5 mM), HCO3- (0–100 mM) and U(VI) (0.0021–0.0084 mM) in the solution mixture. Experiment results suggested that solutions with Si concentrations higher than 50 mM exhibited greater removal efficiencies of U(VI). Solutions with higher concentrations of bicarbonate also exhibited greater removal efficiencies for Si, Al, and U(VI). Overall, the silica polymerization reaction leading to the formation of Si gel correlated with the removal of U(VI), Si, and Al from the solution. If no Si polymerization was observed, there was no U removal from the supernatant solution. Speciation modeling indicated that the dominant uranium species in the

  9. Selecting Presuppositions in Conditional Clauses. Results from a Psycholinguistic Experiment

    PubMed Central

    Domaneschi, Filippo; Carrea, Elena; Penco, Carlo; Greco, Alberto

    2016-01-01

    In this paper, we propose an experiment concerning presupposition selection in conditional sentences containing a presupposition trigger in the consequent. Many theories claim that sentences like if p, qq'—where q is the presupposition of the assertive component q'—have unconditional presuppositions, namely, they simply project q. Other theories suggest that these kinds of conditional sentences project conditional presuppositions of the form if p, q. Data collected suggest two results: (i) in accordance with other experiments (by Romoli), dependence between the presupposition q and the antecedent p favors the selection of a conditional presupposition if p, q. (ii) presupposition selection in conditional sentences with a trigger in the consequent is affected by speakers' cognitive load: if speakers are highly cognitive loaded, then they are less disposed to select a conditional presupposition. We conclude by arguing that cognitive load represents a key factor for the analysis of linguistic and philosophical theories of context. PMID:26793146

  10. Isolation of the catalytically competent small subunit of ribulose bisphosphate carboxylase/oxygenase from spinach under an extremely alkaline condition.

    PubMed

    Incharoensakdi, A; Takabe, T; Takabe, T; Akazawa, T

    1986-07-16

    A method for isolating the small subunit (B) of ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) from spinach leaf using an alkaline buffer (pH 11.2) in combination with sucrose gradient centrifugation is described. Although the yield of isolated subunit B (ca. 20%) was comparable to that previously described (ca. 25%) using the acid precipitation method [Andrews, T.J. and Lorimer, G.H. (1985) J. Biol. Chem. 260: 4632-4636], the isolated subunit B in this report suffered less denaturation (ca. 30%) as estimated from kinetic analysis of its reassembly with large subunit (A) derived from Aphanothece halophytica. Studies on the kinetic properties of the reassembled enzyme molecules suggested that spinach subunit B does not influence the affinity of the enzyme for substrate CO2. The catalytic core (A8) of spinach RuBisCO could not be isolated in the native form.

  11. Decontamination of metals, pentachlorophenol, and polychlorined dibenzo-p-dioxins and dibenzofurans polluted soil in alkaline conditions using an amphoteric biosurfactant.

    PubMed

    Reynier, Nicolas; Blais, Jean-François; Mercier, Guy; Besner, Simon

    2014-01-01

    In this paper, flotation in acidic conditions and alkaline leaching soil washing processes were compared to decontaminate four soils with variable contamination with metals, pentachlorophenol (PCP), and polychlorodibenzo dioxins and furans (PCDD/F). The measured concentrations of the four soils prior treatment were between 50 and 250 mg/kg for As, 35 and 220mg/kg for Cr, 80 and 350mg/kg for Cu, and 2.5 and 30mg/kg for PCP. PCDD/F concentrations reached 1394, 1375, 3730, and 6289ng/kg for F1, S1, S2, and S3 soils, respectively. The tests were carried out with masses of 100g of soil (fraction 0-2 mm) in a 2 L beaker or in a 1 L flotation cell. Soil flotation in sulphuric acid for 1 h at 60 degreeC with three flotation cycles using the surfactant cocamidopropyl betaine (BW) at 1% allows the solubilization of metals and PCP with average removal yields of 85%, 51%, 90%, and 62% for As, Cr, Cu, and PCP, respectively. The alkaline leaching for 2 h at 80 degreeC solubilizes As, Cr, Cu, and PCP with average removal yields of 60%, 32%, 77%, and 87%, respectively. Tests on PCDD/F solubilization with different surfactants were carried out in combination with the alkaline leaching process. PCDD/F removal yields of 25%, 72%, 70%, and 74% for F1, S1, S2, and S3 soils, respectively, were obtained using the optimized conditions.

  12. The effects on DNA migration of altering parameters in the comet assay protocol such as agarose density, electrophoresis conditions and durations of the enzyme or the alkaline treatments.

    PubMed

    Ersson, Clara; Möller, Lennart

    2011-11-01

    The single cell gel electrophoresis (comet assay) is a popular method for measuring DNA migration as an estimate of DNA damage. No standardised comet assay protocol exists, which make comparisons between studies complicated. In a previous inter-laboratory validation study of the comet assay, we identified important parameters in the protocol that might affect DNA migration. The aim of this study was to assess how different comet assay protocols affect DNA migration. The results in this study suggest that (i) there is a significant linear dose-response relationship between the agarose gel's density and DNA migration and that damaged cells are more sensitive to the agarose gel's density; (ii) incubation with formamidopyrimidine DNA glycosylase for 10 min is inadequate, whereas 30 min is sufficient; (iii) the typically used 20 min of alkaline treatment might be to short when analysing samples that contain particular alkali-labile sites (ALS) and (iv) the duration of electrophoresis as well as the strength of the electric field applied affects the DNA migration. By using protocol-specific calibration curves, it is possible to reduce the variation in DNA migration caused by differences in comet assay protocols. This does, however, not completely remove the impact of the durations of alkaline treatment and electrophoresis when analysing cells containing ALS that are relatively resistant to high alkaline treatment.

  13. Crystallization conditions of porphyritic high-K calc-alkaline granitoids in the extreme northeastern Borborema Province, NE Brazil, and geodynamic implications

    NASA Astrophysics Data System (ADS)

    Campos, Benedita Cleide Souza; Vilalva, Frederico Castro Jobim; Nascimento, Marcos Antônio Leite do; Galindo, Antônio Carlos

    2016-10-01

    An integrated textural and chemical study on amphibole, biotite, plagioclase, titanite, epidote, and magnetite was conducted in order to estimate crystallization conditions, along with possible geodynamic implications, for six Ediacaran porphyritic high-K calc-alkaline granite plutons (Monte das Gameleiras, Barcelona, Acari, Caraúbas, Tourão, and Catolé do Rocha) intrusive into Archean to Paleoproterozoic rocks of the São José do Campestre (SJCD) and Rio Piranhas-Seridó (RPSD) domains, northern Borborema Province. The studied rocks include mainly porphyritic leucocratic monzogranites, as well as quartz-monzonites and granodiorites. Textures are marked by K-feldspar megacrysts (5-15 cm long) in a fine-to medium-grained matrix composed of quartz, plagioclase, amphibole, biotite, as well as titanite, epidote, Fesbnd Ti oxides, allanite, apatite, and zircon as accessory minerals. Amphibole, biotite and titanite share similar compositional variations defined by increasing Al and Fe, and decreasing Mg contents from the plutons emplaced into the SJCP (Monte das Gameleiras and Barcelona) towards those in the RPSD (Acari, Caraúbas, Tourão, and Catolé do Rocha). Estimated intensive crystallization parameters reveal a weak westward range of increasing depth of emplacement, pressure and temperature in the study area. The SJCD plutons (to the east) crystallized at shallower crustal depths (14-21 km), under slightly lower pressure (3.8-5.5 kbar) and temperature (701-718 °C) intervals, and high to moderate oxygen fugacity conditions (+0.8 < ΔFQM < +2.0). On the other hand, the RPSD plutons (to the west) were emplaced at slightly deeper depths (18-23 km), under higher, yet variable pressures (4.8-6.2 kbar), temperatures (723-776 °C), and moderate to low oxygen fugacity conditions (-1.0 < ΔFQM < +1.8). These results reinforce the contrasts between the tectono-strutuctural domains of São José do Campestre and Rio Piranhas-Seridó in the northern Borborema Province.

  14. Experimental results from containment piping bellows subjected to severe accident conditions: Results from bellows tested in corroded conditions. Volume 2

    SciTech Connect

    Lambert, L.D.; Parks, M.B.

    1995-10-01

    Bellows are an integral part of the containment pressure boundary in nuclear power plants. They are used at piping penetrations to allow relative movement between piping and the containment wall, while minimizing the load imposed on the piping and wall. Piping bellows are primarily used in steel containments; however, they have received limited use in some concrete (reinforced and prestressed) containments. In a severe accident they may be subjected to pressure and temperature conditions that exceed the design values, along with a combination of axial and lateral deflections. A test program to determine the leak-tight capacity of containment penetration bellows is being conducted at Sandia National Laboratories under the sponsorship of the US Nuclear Regulatory Commission. Several different bellows geometries, representative of actual containment bellows, have been subjected to extreme deflections along with pressure and temperature loads. The bellows geometries and loading conditions are described along with the testing apparatus and procedures. A total of nineteen bellows have been tested. Thirteen bellows were tested in ``like-new`` condition (results reported in Volume 1), and six were tested in a corroded condition. The tests showed that bellows in ``like-new`` condition are capable of withstanding relatively large deformations, up to, or near, the point of full compression or elongation, before developing leakage, while those in a corroded condition did not perform as well, depending on the amount of corrosion. The corroded bellows test program and results are presented in this report.

  15. Pressure, temperature and oxygen fugacity conditions of calc-alkaline granitoids, Eastern Desert of Egypt, and tectonic implications

    NASA Astrophysics Data System (ADS)

    Helmy, H. M.; Ahmed, A. F.; El Mahallawi, M. M.; Ali, S. M.

    2004-02-01

    Five calc-alkaline plutons; Um Tagher, Abu Zawil, Um Gidri, Um Anab and El Ghuzah, in the northern Eastern Desert of Egypt were subjected to petrographic and mineralogical investigations. They are composed of varying proportions of quartz + plagioclase + potash feldspar + biotite + hornblende ± epidote ± calcite + titanite + magnetite + apatite and zircon. Electron microprobe analyses of coexisting hornblende and plagioclase (hornblende-plagioclase thermometry), Al content in hornblende (aluminum-in-hornblende barometry) and the assemblage titanite-magnetite-quartz were used to constrain the P, T and fO 2 during the crystallization of the parent magmas in the different plutons. The plutons crystallized under varying pressures (5.4-2.1 kbar) and wide range of temperature (785-588 °C) from highly oxidized magmas (log fO 2 -21 to -13). The pressure data discriminate three categories of granitoid emplaced at different crustal levels: (a) upper crust granitoids (e.g., El Ghuzah, and Abu Zawil) emplaced at depths <9 km; (b) intermediate crust granitoids (e.g., Um Gidri and Um Anab) emplaced at depths <13 km; and (c) lower crust granitoids (e.g., Um Tagher) emplaced at depths <21 km. The depths of emplacement seem to increase from northwest to southeast. It is likely that the magmas forming these plutons were generated at different depths; they were similar in composition but varied substantially in their water and volatile contents. High water and volatile contents allowed the magma of some plutons to reach shallower crustal levels without complete solidification. Although these complexes were crystallized at different depths, they were later uplifted to the same level by upward faulting.

  16. Additional Results of Ice-Accretion Scaling at SLD Conditions

    NASA Technical Reports Server (NTRS)

    Bond, Thomas H. (Technical Monitor); Anderson, David N.; Tsao, Jen-Ching

    2005-01-01

    To determine scale velocity an additional similarity parameter is needed to supplement the Ruff scaling method. A Weber number based on water droplet MVD has been included in several studies because the effect of droplet splashing on ice accretion was believed to be important, particularly for SLD conditions. In the present study, ice shapes recorded at Appendix-C conditions and recent results at SLD conditions are reviewed to show that droplet diameter cannot be important to main ice shape, and for low airspeeds splashing does not appear to affect SLD ice shapes. Evidence is presented to show that while a supplementary similarity parameter probably has the form of a Weber number, it must be based on a length proportional to model size rather than MVD. Scaling comparisons were made between SLD reference conditions and Appendix-C scale conditions using this Weber number. Scale-to-reference model size ratios were 1:1.7 and 1:3.4. The reference tests used a 91-cm-chord NACA 0012 model with a velocity of approximately 50 m/s and an MVD of 160 m. Freezing fractions of 0.3, 0.4, and 0.5 were included in the study.

  17. Evaluation of the efficacy of polyphosphate remediation technology: Direct and indirect remediation of uranium under alkaline conditions

    SciTech Connect

    Wellman, Dawn M.; Fruchter, Jonathan S.; Vermeul, Vincent R.; Richards, Emily L.; Jansik, Danielle P.; Edge, Ellen

    2011-08-31

    A field-scale technology demonstration has been conducted to optimize polyphosphate remediation technology for enhanced monitored natural attenuation of the uranium plume within the 300 Area aquifer at the Hanford Site, southeastern Washington State. The objective was to evaluate the efficacy of polyphosphate to treat uranium-contaminated groundwater in situ. Focused application of polyphosphate was conducted in a source or 'hot spot' area to reduce the inventory of available uranium contributing to the groundwater plume through direct precipitation of uranyl-phosphate solids and secondary containment via precipitation of apatite which can serve as a long-term sorbent for uranium. The test site consisted of an injection well and 15 monitoring wells installed in the 300 Area near the process trenches that had previously received uranium-bearing effluents. The results indicated sequestration of uranium as insoluble phosphate phases appears to be a promising alternative for treating the uranium- contaminated groundwater at the Hanford Site 300 Area. However, the formation of the apatite during the test was limited due to two separate overarching issues: (1) formation and emplacement of apatite via polyphosphate technology, and (2) efficacy of apatite for sequestering uranium under the present geochemical and hydrodynamic conditions.

  18. Fluorescence spectroscopic analysis of the structure and dynamics of Bacillus subtilis lipase A governing its activity profile under alkaline conditions.

    PubMed

    Kübler, Daniel; Ingenbosch, Kim N; Bergmann, Anna; Weidmann, Monika; Hoffmann-Jacobsen, Kerstin

    2015-12-01

    Because of their vast diversity of substrate specificity and reaction conditions, lipases are versatile materials for biocatalysis. Lipase A from Bacillus subtilis (BSLA) is the smallest lipase yet discovered. It has the typical α/β hydrolase fold but lacks a lid covering the substrate cleft. In this study, the pH-dependence of the activity, stability, structure, and dynamics of BSLA was investigated by fluorescence spectroscopy. By use of a fluorogenic substrate it was revealed that the optimum pH for BSLA activity is 8.5 whereas thermodynamic and kinetic stability are maximum at pH 10. The origin of this behavior was clarified by investigation of ANS (8-anilino-1-naphthalenesulfonic acid) binding and fluorescence quenching of the two single tryptophan mutants W31F and W42F. Variations in segmental dynamics were investigated by use of time-resolved fluorescence anisotropy. This analysis showed that the activity maximum is governed by high surface hydrophobicity and high segmental mobility of surface loops whereas the stability optimum is a result of low segmental mobility and surface hydrophobicity.

  19. Additional Results of Glaze Icing Scaling in SLD Conditions

    NASA Technical Reports Server (NTRS)

    Tsao, Jen-Ching

    2016-01-01

    New guidance of acceptable means of compliance with the super-cooled large drops (SLD) conditions has been issued by the U.S. Department of Transportation's Federal Aviation Administration (FAA) in its Advisory Circular AC 25-28 in November 2014. The Part 25, Appendix O is developed to define a representative icing environment for super-cooled large drops. Super-cooled large drops, which include freezing drizzle and freezing rain conditions, are not included in Appendix C. This paper reports results from recent glaze icing scaling tests conducted in NASA Glenn Icing Research Tunnel (IRT) to evaluate how well the scaling methods recommended for Appendix C conditions might apply to SLD conditions. The models were straight NACA 0012 wing sections. The reference model had a chord of 72 in. and the scale model had a chord of 21 in. Reference tests were run with airspeeds of 100 and 130.3 kn and with MVD's of 85 and 170 micron. Two scaling methods were considered. One was based on the modified Ruff method with scale velocity found by matching the Weber number WeL. The other was proposed and developed by Feo specifically for strong glaze icing conditions, in which the scale liquid water content and velocity were found by matching reference and scale values of the nondimensional water-film thickness expression and the film Weber number Wef. All tests were conducted at 0 deg AOA. Results will be presented for stagnation freezing fractions of 0.2 and 0.3. For nondimensional reference and scale ice shape comparison, a new post-scanning ice shape digitization procedure was developed for extracting 2-D ice shape profiles at any selected span-wise location from the high fidelity 3-D scanned ice shapes obtained in the IRT.

  20. Additional Results of Glaze Icing Scaling in SLD Conditions

    NASA Technical Reports Server (NTRS)

    Tsao, Jen-Ching

    2016-01-01

    New guidance of acceptable means of compliance with the super-cooled large drops (SLD) conditions has been issued by the U.S. Department of Transportation's Federal Aviation Administration (FAA) in its Advisory Circular AC 25-28 in November 2014. The Part 25, Appendix O is developed to define a representative icing environment for super-cooled large drops. Super-cooled large drops, which include freezing drizzle and freezing rain conditions, are not included in Appendix C. This paper reports results from recent glaze icing scaling tests conducted in NASA Glenn Icing Research Tunnel (IRT) to evaluate how well the scaling methods recommended for Appendix C conditions might apply to SLD conditions. The models were straight NACA 0012 wing sections. The reference model had a chord of 72 inches and the scale model had a chord of 21 inches. Reference tests were run with airspeeds of 100 and 130.3 knots and with MVD's of 85 and 170 microns. Two scaling methods were considered. One was based on the modified Ruff method with scale velocity found by matching the Weber number W (sub eL). The other was proposed and developed by Feo specifically for strong glaze icing conditions, in which the scale liquid water content and velocity were found by matching reference and scale values of the non-dimensional water-film thickness expression and the film Weber number W (sub ef). All tests were conducted at 0 degrees angle of arrival. Results will be presented for stagnation freezing fractions of 0.2 and 0.3. For non-dimensional reference and scale ice shape comparison, a new post-scanning ice shape digitization procedure was developed for extracting 2-dimensional ice shape profiles at any selected span-wise location from the high fidelity 3-dimensional scanned ice shapes obtained in the IRT.

  1. [Experimental Conditions and Reliability Analysis of Results of COD components].

    PubMed

    Li, Zhi-hua; Zhang, Yin; Han, Xing; Yu, Ke; Li, Ru-jia

    2015-10-01

    The present study attempts to use SF( OUR(max)/OUR(en)) instead of S(0)/X(0) as an index of optimal initial conditions for determination of COD components by means of respirometry, thereby simplifying the measuring process and the operation can be automated. Further, the ratio of COD consumed by the growth of biomass can be used for the reliability assessment of results. Experimental results show that, experimental conditions for obtaining good results as follows: (1) for samples that composed of a large amount of easily biodegradable components (e. g., synthetic wastewater made by sodium acetate), SF should be in the range of 2.8 to 5.3, and the ratio of COD consumed by growth of biomass should be less than 30%; (2) for samples that composed of both readily biodegradable and slowly biodegradable components (i. e., typical domestic wastewater), SF should be in the range of 5.8 to 6.4, and the ratio of COD consumed by growth of biomass should be less than 30%; (3) and for samples that composed of a large amount of slowly biodegradable industrial wastewater (i. e., landfill leachate), SF should be 15 or less, and the ratio of COD consumed by growth of biomass should be approximately 40%. Therefore, when respirometry is used for the determination of COD components, the optimal conditions in terms of SF increase with the complexity of carbon source.

  2. Helium at White Dwarf Photospheric Conditions: Preliminary Laboratory Results

    NASA Astrophysics Data System (ADS)

    Schaeuble, M.; Falcon, R. E.; Gomez, T. A.; Winget, D. E.; Montgomery, M. H.; Bailey, J. E.

    2017-03-01

    We present preliminary results of an experimental study exploring helium at photospheric conditions of white dwarf stars. These data were collected at Sandia National Laboratories' Z-machine, the largest x-ray source on earth. Our helium results could have many applications ranging from validating current DB white dwarf model atmospheres to providing accurate He pressure shifts at varying temperatures and densities. In a much broader context, these helium data can be used to guide theoretical developments in new continuum-lowering models for two-electron atoms. We also discuss future applications of our updated experimental design, which enables us to sample a greater range of densities, temperatures, and gas compositions.

  3. CoxC encased in carbon nanotubes: an efficient oxygen reduction catalyst under both acidic and alkaline conditions.

    PubMed

    Chen, Lisong; Cui, Xiangzhi; Wang, Qingsong; Zhang, Xiaohua; Wan, Gang; Cui, Fangming; Wei, Chenyang; Shi, Jianlin

    2015-12-21

    The design of a non-precious metal oxygen reduction reaction (ORR) catalyst of high activity and long durability in acidic electrolyte is of great importance for the development and commercialization of low-temperature fuel cells, which remains a great challenge to date. Here, we demonstrate a facile, scalable protocol for the controlled synthesis of CoxC encapsulated in carbon nanotubes as a novel kind of efficient electrochemical oxygen reduction reaction (ORR) catalyst. The synthesized CoxC/carbon nanotube features a high BET surface area, large pore volume and high graphitic content, which greatly favors enhanced ORR properties. The resultant composite electro-catalyst shows high ORR activity which is comparable with that of 20 wt% Pt/C in 0.1 M KOH electrolyte. More importantly, it also exhibits a high ORR activity in 0.1 M HClO4 with a near-complete 4e pathway. More attractively, compared to the most investigated FexC, CoxC as the proposed main catalytically active center shows much enhanced activity in acidic electrolyte, which will pave the way towards the rational design of an advanced electro-catalyst for an efficient ORR process especially under acidic conditions. Moreover, a fuel cell using the synthesized CoxC/carbon nanotube as a cathode catalyst showed a large open-circuit potential, high output power density and long durability, which make it a promising alternative to Pt/C as a non-precious metal ORR catalyst in proton exchange membrane fuel cells.

  4. Reinforcement learning accounts for moody conditional cooperation behavior: experimental results

    PubMed Central

    Horita, Yutaka; Takezawa, Masanori; Inukai, Keigo; Kita, Toshimasa; Masuda, Naoki

    2017-01-01

    In social dilemma games, human participants often show conditional cooperation (CC) behavior or its variant called moody conditional cooperation (MCC), with which they basically tend to cooperate when many other peers have previously cooperated. Recent computational studies showed that CC and MCC behavioral patterns could be explained by reinforcement learning. In the present study, we use a repeated multiplayer prisoner’s dilemma game and the repeated public goods game played by human participants to examine whether MCC is observed across different types of game and the possibility that reinforcement learning explains observed behavior. We observed MCC behavior in both games, but the MCC that we observed was different from that observed in the past experiments. In the present study, whether or not a focal participant cooperated previously affected the overall level of cooperation, instead of changing the tendency of cooperation in response to cooperation of other participants in the previous time step. We found that, across different conditions, reinforcement learning models were approximately as accurate as a MCC model in describing the experimental results. Consistent with the previous computational studies, the present results suggest that reinforcement learning may be a major proximate mechanism governing MCC behavior. PMID:28071646

  5. Reinforcement learning accounts for moody conditional cooperation behavior: experimental results.

    PubMed

    Horita, Yutaka; Takezawa, Masanori; Inukai, Keigo; Kita, Toshimasa; Masuda, Naoki

    2017-01-10

    In social dilemma games, human participants often show conditional cooperation (CC) behavior or its variant called moody conditional cooperation (MCC), with which they basically tend to cooperate when many other peers have previously cooperated. Recent computational studies showed that CC and MCC behavioral patterns could be explained by reinforcement learning. In the present study, we use a repeated multiplayer prisoner's dilemma game and the repeated public goods game played by human participants to examine whether MCC is observed across different types of game and the possibility that reinforcement learning explains observed behavior. We observed MCC behavior in both games, but the MCC that we observed was different from that observed in the past experiments. In the present study, whether or not a focal participant cooperated previously affected the overall level of cooperation, instead of changing the tendency of cooperation in response to cooperation of other participants in the previous time step. We found that, across different conditions, reinforcement learning models were approximately as accurate as a MCC model in describing the experimental results. Consistent with the previous computational studies, the present results suggest that reinforcement learning may be a major proximate mechanism governing MCC behavior.

  6. Alkaline flooding injection strategy

    SciTech Connect

    French, T.R.; Josephson, C.B.

    1992-03-01

    The objective of this project is to improved alkali-surfactant flooding methods, and this includes determining the proper design of injection strategy. Several different injection strategies have been used or suggested for recovering heavy oils with surfactant-enhanced alkaline flooding methods. Oil recovery was compared for four different injection strategies: (1) surfactant followed by polymer, (2) surfactant followed by alkaline polymer, (3) alkaline surfactant followed by polymer, and (4) alkali, surfactant, and polymer mixed in a single formulation. The effect of alkaline preflush was also studied under two different conditions. All of the oil recovery experiments were conducted under optimal conditions with a viscous, non-acidic oil from Hepler (KS) oil field. The coreflood experiments were conducted with Berea sandstone cores since field core was not available in sufficient quantity for coreflood tests. The Tucker sand of Hepler field is a Class I fluvial dominated deltaic reservoir, as classified by the Department of Energy, which has been selected as the site of a DOE-sponsored field pilot test.

  7. Copper release in low and high alkaline water.

    PubMed

    D'Antonio, L; Fabbricino, M; Nasso, M; Trifuoggi, M

    2008-04-01

    Copper release in drinking water, caused by electrochemical corrosion of household distribution systems, was investigated. Experiments were developed testing both low and high alkaline water in stagnant conditions. The effect of varying stagnation time was investigated also. Both soluble and insoluble copper compounds, produced by corrosion processes are quantified, using appropriate experimental procedures. On the basis of obtained results, copper concentration in stagnant water is defined as a function of water alkalinity, while total metal release is defined as a function of stagnation length, and is not dependent on water alkalinity.

  8. Probability distributions of continuous measurement results for conditioned quantum evolution

    NASA Astrophysics Data System (ADS)

    Franquet, A.; Nazarov, Yuli V.

    2017-02-01

    We address the statistics of continuous weak linear measurement on a few-state quantum system that is subject to a conditioned quantum evolution. For a conditioned evolution, both the initial and final states of the system are fixed: the latter is achieved by the postselection in the end of the evolution. The statistics may drastically differ from the nonconditioned case, and the interference between initial and final states can be observed in the probability distributions of measurement outcomes as well as in the average values exceeding the conventional range of nonconditioned averages. We develop a proper formalism to compute the distributions of measurement outcomes, and evaluate and discuss the distributions in experimentally relevant setups. We demonstrate the manifestations of the interference between initial and final states in various regimes. We consider analytically simple examples of nontrivial probability distributions. We reveal peaks (or dips) at half-quantized values of the measurement outputs. We discuss in detail the case of zero overlap between initial and final states demonstrating anomalously big average outputs and sudden jump in time-integrated output. We present and discuss the numerical evaluation of the probability distribution aiming at extending the analytical results and describing a realistic experimental situation of a qubit in the regime of resonant fluorescence.

  9. Kinetic Evidence for Near Irreversible Nonionic Micellar Entrapment of N-(2′-Methoxyphenyl)phthalimide (1) under the Typical Alkaline Reaction Conditions

    PubMed Central

    Khan, M. Niyaz; Sim, Yoke-Leng; Ariffin, Azhar

    2014-01-01

    The values of pseudo-first-order rate constants (kobs) for alkaline hydrolysis of 1, obtained at 1.0 mM NaOH and within [ CmEnT] (total concentration of CmEn) range of 3.0–5.0 mM for C12E23 and 10–20 mM for C18E20, fail to obey pseudophase micellar (PM) model. The values of the fraction of near irreversible CmEn micellar trapped 1 molecules (FIT1) vary in the range ~0–0.75 for C12E23 and ~0–0.83 for C18E20 under such conditions. The values of FIT1 become 1.0 at ≥10 mM C12E23 and 50 mM C18E20. Kinetic analysis of the observed data at ≥10 mM C12E23 shows near irreversible micellar entrapment of 1 molecules under such conditions. PMID:24574900

  10. Re-analysis results using medians of the data from the JaCVAM-organized international validation study of the in vivo rat alkaline comet assay.

    PubMed

    Uno, Yoshifumi; Omori, Takashi

    2015-07-01

    The data from the JaCVAM-organized international validation study of the in vivo rat alkaline comet assay were reported and analyzed statistically using the simple means of % tail DNA. However, OECD test guideline TG 489 recommends use of the median for data analysis due to the hierarchical nature of the data. Comparison between the simple mean approach and the median based approach for positive/negative/equivocal chemical calls was conducted using the % tail DNA data for the 40 chemicals tested in the JaCVAM-organized international validation study of the in vivo rat alkaline comet assay, using liver and stomach as target organs. In the liver, two genotoxic chemicals, o-anisidine and 9-aminoacridine hydrochloride monohydrate, were positive using the median based approach but negative using the simple mean approach, and two genotoxic chemicals, 2-acetylaminofluorene and busulfan were equivocal using the median based approach but negative using the simple mean approach. In contrast, cadmium chloride (genotoxic carcinogen) was equivocal in both organs using the median based approach, while positive and equivocal in liver and stomach, respectively, using the simple mean approach. Two data sets of sodium arsenite showed equivocal and negative results for liver using the median based approach, although both data sets were equivocal using the simple mean approach. Overall, there are no large differences in terms of the genotoxic call between both approaches. However, the median based approach recommended in OECD TG 489 has an advantage toward higher precision within the groups treated with a test chemical, whereas the approach might show the lower values for the effect.

  11. Ethylene Inhibits Root Elongation during Alkaline Stress through AUXIN1 and Associated Changes in Auxin Accumulation.

    PubMed

    Li, Juan; Xu, Heng-Hao; Liu, Wen-Cheng; Zhang, Xiao-Wei; Lu, Ying-Tang

    2015-08-01

    Soil alkalinity causes major reductions in yield and quality of crops worldwide. The plant root is the first organ sensing soil alkalinity, which results in shorter primary roots. However, the mechanism underlying alkaline stress-mediated inhibition of root elongation remains to be further elucidated. Here, we report that alkaline conditions inhibit primary root elongation of Arabidopsis (Arabidopsis thaliana) seedlings by reducing cell division potential in the meristem zones and that ethylene signaling affects this process. The ethylene perception antagonist silver (Ag(+)) alleviated the inhibition of root elongation by alkaline stress. Moreover, the ethylene signaling mutants ethylene response1-3 (etr1-3), ethylene insensitive2 (ein2), and ein3-1 showed less reduction in root length under alkaline conditions, indicating a reduced sensitivity to alkalinity. Ethylene biosynthesis also was found to play a role in alkaline stress-mediated root inhibition; the ethylene overproducer1-1 mutant, which overproduces ethylene because of increased stability of 1-AMINOCYCLOPROPANE-1-CARBOXYLIC ACID SYNTHASE5, was hypersensitive to alkaline stress. In addition, the ethylene biosynthesis inhibitor cobalt (Co(2+)) suppressed alkaline stress-mediated inhibition of root elongation. We further found that alkaline stress caused an increase in auxin levels by promoting expression of auxin biosynthesis-related genes, but the increase in auxin levels was reduced in the roots of the etr1-3 and ein3-1 mutants and in Ag(+)/Co(2+)-treated wild-type plants. Additional genetic and physiological data showed that AUXIN1 (AUX1) was involved in alkaline stress-mediated inhibition of root elongation. Taken together, our results reveal that ethylene modulates alkaline stress-mediated inhibition of root growth by increasing auxin accumulation by stimulating the expression of AUX1 and auxin biosynthesis-related genes.

  12. The Fate Of Silicon During Glass Corrosion Under Alkaline Conditions: A Mechanistic And Kinetic Study With The International Simple Glass

    SciTech Connect

    Gin, Stephane; Jollivet, Patrick; Fournie, Maxime; Berthon, Claude; Wang, Zhaoying; Mitroshkov, Alexandre V.; Zhu, Zihua; Ryan, Joseph V.

    2015-02-01

    International Simple Glass - a six oxide borosilicate glass selected by the international nuclear glass community to improve the understanding of glass corrosion mechanisms and kinetics - was altered at 90°C in a solution initially saturated with respect to amorphous 29-SiO2. The pH90°C, was fixed at 9 at the start of the experiment and raised to 11.5 after 209 d by the addition of KOH. Isotope sensitive analytical techniques were used to analyze the solution and altered glass samples, helping to understand the driving forces and rate limiting processes controlling long-term glass alteration. At pH 9, the corrosion rate continuously drops and the glass slowly transforms into a uniform, homogeneous and isovolumic amorphous alteration layer. The mechanisms responsible for this transformation are water diffusion through the growing alteration layer and ion exchange. We demonstrate that this amorphous alteration layer is not a precipitate resulting from the hydrolysis of the silicate network; it inherits from the glass structure from which the most weakly bonded cations (Na, Ca and B) have been released. At pH 11.5, the alteration process is very different: the high solubility of glass network formers (Si, Al, Zr) triggers the rapid and complete dissolution of the glass (dissolution becomes congruent) and precipitation of amorphous and crystalline phases. Unlike at pH 9 where glass corrosion rate decreased by 3 orders of magnitude likely due to transport-limiting phenomenon within the amorphous alteration layer, the rate at pH 11.5 is maintained at a value close to the forward rate due to both the hydrolysis of the silicate network and the precipitation of CSH and zeolites. This study provides key information for a unified model for glass dissolution.

  13. Electro-oxidation of methanol in alkaline conditions using Pd-Ni nanoparticles prepared from organometallic precursors and supported on carbon vulcan

    NASA Astrophysics Data System (ADS)

    Manzo-Robledo, A.; Costa, Natália J. S.; Philippot, K.; Rossi, Liane M.; Ramírez-Meneses, E.; Guerrero-Ortega, L. P. A.; Ezquerra-Quiroga, S.

    2015-12-01

    Oxidation of low-molecular weight alcohols as energy sources using metal nanoparticles has attracted considerable interest for use as a power source in portable electronic devices. In this work, a series of mono- and bimetallic nanoparticles based on palladium and nickel (Pd, Pd90Ni10, Pd50Ni50, Pd10Ni90, and Ni) have been synthesized from organometallic precursors, namely tris(dibenzylideneacetone) dipalladium(0), Pd2(dba)3, and bis(1,5-cyclooctadiene)nickel(0), Ni(cod)2. Well-defined metal particles in the nanometric scale from 4.2 to 6.3 nm were observed by transmission electron microscopy. The as-prepared nanoparticles were mixed with a carbon Vulcan matrix (10 % wt. of the catalyst in turn) for investigation as electrocatalysts in methanol oxidation reaction (MOR) in alkaline conditions. The i- E profiles from cyclic voltammetry for the monometallic systems indicated a redox process attributed only to palladium or nickel, as expected. With the bimetallic nanomaterials, the redox process and the i- E characteristics are functions of the amount of nickel associated to palladium. From a fundamental point of view, it has been established that the OH ions' interfacial interaction and the MOR kinetics are affected by the presence of nickel (decreasing the faradic current) as supported by the current versus potential profiles obtained as a function of methanol concentration and with temperature variation.

  14. Constitutive expression of a barley Fe phytosiderophore transporter increases alkaline soil tolerance and results in iron partitioning between vegetative and storage tissues under stress.

    PubMed

    Gómez-Galera, Sonia; Sudhakar, Duraialagaraja; Pelacho, Ana M; Capell, Teresa; Christou, Paul

    2012-04-01

    Cereals have evolved chelation systems to mobilize insoluble iron in the soil, but in rice this process is rather inefficient, making the crop highly susceptible to alkaline soils. We therefore engineered rice to express the barley iron-phytosiderophore transporter (HvYS1), which enables barley plants to take up iron from alkaline soils. A representative transgenic rice line was grown in standard (pH 5.5) or alkaline soil (pH 8.5) to evaluate alkaline tolerance and iron mobilization. Transgenic plants developed secondary tillers and set seeds when grown in standard soil although iron concentration remained similar in leaves and seeds compared to wild type. However, when grown in alkaline soil transgenic plants exhibited enhanced growth, yield and iron concentration in leaves compared to the wild type plants which were severely stunted. Transgenic plants took up iron more efficiently from alkaline soil compared to wild type, indicating an enhanced capacity to increase iron mobility ex situ. Interestingly, all the additional iron accumulated in vegetative tissues, i.e. there was no difference in iron concentration in the seeds of wild type and transgenic plants. Our data suggest that iron uptake from the rhizosphere can be enhanced through expression of HvYS1 and confirm the operation of a partitioning mechanism that diverts iron to leaves rather than seeds, under stress.

  15. Styrene-spaced copolymers including anthraquinone and β-O-4 lignin model units: synthesis, characterization and reactivity under alkaline pulping conditions.

    PubMed

    Megiatto, Jackson D; Cazeils, Emmanuel; Ham-Pichavant, Frédérique; Grelier, Stéphane; Gardrat, Christian; Castellan, Alain

    2012-05-14

    A series of random copoly(styrene)s has been synthesized via radical polymerization of functionalized anthraquinone (AQ) and β-O-4 lignin model monomers. The copolymers were designed to have a different number of styrene spacer groups between the AQ and β-O-4 lignin side chains aiming at investigating the distance effects on AQ/β-O-4 electron transfer mechanisms. A detailed molecular characterization, including techniques such as size exclusion chromatography, MALDI-TOF mass spectrometry, and (1)H, (13)C, (31)P NMR and UV-vis spectroscopies, afforded quantitative information about the composition of the copolymers as well as the average distribution of the AQ and β-O-4 groups in the macromolecular structures. TGA and DSC thermal analysis have indicated that the copolymers were thermally stable under regular pulping conditions, revealing the inertness of the styrene polymer backbone in the investigation of electron transfer mechanisms. Alkaline pulping experiments showed that close contact between the redox active side chains in the copolymers was fundamental for an efficient degradation of the β-O-4 lignin model units, highlighting the importance of electron transfer reactions in the lignin degradation mechanisms catalyzed by AQ. In the absence of glucose, AQ units oxidized phenolic β-O-4 lignin model parts, mainly by electron transfer leading to vanillin as major product. By contrast, in presence of glucose, anthrahydroquinone units (formed by reduction of AQ) reduced the quinone-methide units (issued by dehydration of phenolic β-O-4 lignin model part) mainly by electron transfer leading to guaiacol as major product. Both processes were distance dependent.

  16. Alkaline quinone flow battery.

    PubMed

    Lin, Kaixiang; Chen, Qing; Gerhardt, Michael R; Tong, Liuchuan; Kim, Sang Bok; Eisenach, Louise; Valle, Alvaro W; Hardee, David; Gordon, Roy G; Aziz, Michael J; Marshak, Michael P

    2015-09-25

    Storage of photovoltaic and wind electricity in batteries could solve the mismatch problem between the intermittent supply of these renewable resources and variable demand. Flow batteries permit more economical long-duration discharge than solid-electrode batteries by using liquid electrolytes stored outside of the battery. We report an alkaline flow battery based on redox-active organic molecules that are composed entirely of Earth-abundant elements and are nontoxic, nonflammable, and safe for use in residential and commercial environments. The battery operates efficiently with high power density near room temperature. These results demonstrate the stability and performance of redox-active organic molecules in alkaline flow batteries, potentially enabling cost-effective stationary storage of renewable energy.

  17. Advanced alkaline water electrolysis

    NASA Astrophysics Data System (ADS)

    Wakabayashi, N.; Torikai, E.; Kawami, Y.; Takenaka, H.

    Results are presented of experimental studies of possible separators and electrodes for use in advanced, high-temperature, high-pressure alkaline water electrolyzers. Material evaluations in alkaline water electrolyzers at temperatures from 100 to 120 C have shown a new type polytetrafluoroethylene membrane impregnated with potassium titanate to be the most promising when the separator is prepared by the hydrothermal treatment of a porous PFTE membrane impregnated with hydrated titanium oxide. Measurements of cell voltages in 30% KOH at current densities from 5 to 100 A/sq dm at temperatures up to 120 C with nickel electrodes of various structures have shown the foamed nickel electrode, with an average pore size of 1-1.5 mm, to have the best performance. When the foamed nickel is coated by fine powdered nickel, carbonyl nickel or Raney nickel to increase electrode surface areas, even lower cell voltages were found, indicating better performance.

  18. Characterization of the Proteomic Profiles of the Brown Tide Alga Aureoumbra lagunensis under Phosphate- and Nitrogen-Limiting Conditions and of Its Phosphate Limitation-Specific Protein with Alkaline Phosphatase Activity

    PubMed Central

    Sun, Ming-Ming; Sun, Jin; Qiu, Jian-Wen; Jing, Hongmei

    2012-01-01

    The persistent bloom of the brown tide alga Aureoumbra lagunensis has been reported in coastal embayments along southern Texas, but the molecular mechanisms that sustain such algal bloom are unknown. We compared the proteome and physiological parameters of A. lagunensis grown in phosphate (P)-depleted, P- and nitrogen (N)-depleted, and nutrient-replete cultures. For the proteomic analysis, samples from three conditions were subjected to two-dimensional electrophoresis and tandem mass spectrometry analysis. Because of the paucity of genomic resources in this species, a de novo cross-species protein search was used to identify the differentially expressed proteins, which revealed their involvement in several key biological processes, such as chlorophyll synthesis, antioxidative protection, and protein degradation, suggesting that A. lagunensis may adopt intracellular nutrient compensation, extracellular organic nutrient regeneration, and damage protection to thrive in P-depleted environments. A highly abundant P limitation-specific protein, tentatively identified as a putative alkaline phosphatase, was further characterized by enzyme activity assay on nondenaturing gel and confocal microscopy, which confirmed that this protein has alkaline phosphatase activity, is a cytoplasmic protein, and is closely associated with the cell membrane. The abundance, location, and functional expression of this alkaline phosphatase all indicate the importance of organic P utilization for A. lagunensis under P limitation and the possible role of this alkaline phosphatase in regenerating phosphate from extra- or intracellular organic phosphorus. PMID:22247172

  19. Alkaline detergent recycling via ultrafiltration

    SciTech Connect

    Steffani, C.; Meltzer, M.

    1995-06-01

    The metal finishing industry uses alkaline cleaners and detergents to remove oils and dirt from manufactured parts, often before they are painted or plated. The use of these cleaners has grown because environmental regulations are phasing out ozone depleting substances and placing restrictions on the use and disposal of many hazardous solvents. Lawrence Livermore National Laboratory is examining ultrafiltration as a cleaning approach that reclaims the cleaning solutions and minimizes wastes. The ultrafiltration membrane is made from sheets of polymerized organic film. The sheets are rolled onto a supporting frame and installed in a tube. Spent cleaning solution is pumped into a filter chamber and filtered through the membrane that captures oils and dirt and allows water and detergent to pass. The membrane is monitored and when pressure builds from oil and dirt, an automatic system cleans the surface to maintain solution flow and filtration quality. The results show that the ultrafiltration does not disturb the detergent concentration or alkalinity but removed almost all the oils and dirt leaving the solution in condition to be reused.

  20. Stability of polydopamine and poly(DOPA) melanin-like films on the surface of polymer membranes under strongly acidic and alkaline conditions.

    PubMed

    Wei, Houliang; Ren, Jun; Han, Bo; Xu, Li; Han, Lulu; Jia, Lingyun

    2013-10-01

    This study investigated the stability of polydopamine and poly(3,4-dihydroxyphenylalanine) (poly(DOPA)) melanin-like films on the surface of polymer substrates. Three polymer membranes, polypropylene (PP), poly(vinylidenefluoride) (PVDF) and nylon, were modified with polydopamine or poly(DOPA), and then immersed in 0.1M HCl or NaOH, followed by UV-vis spectrometry analysis to detect the presence of film detachment. The results showed that the outer parts of both polydopamine and poly(DOPA) films were detached, probably due to electrostatic repulsion between the polymers within the film, when the modified membranes were washed in HCl or NaOH solution. These two films were more stable in strongly acidic solution, but the stability of poly(DOPA) film was better than that of polydopamine film. Compared to the films on the surface of PVDF or nylon membrane, films on PP surface showed the lowest stability, possibly because of the hydrophobic property of PP. The process of film detachment was analyzed by GPC, which showed that unreacted dopamine or DOPA monomers were still present in the freshly formed films. The unreacted monomers, as well as polydopamine or poly(DOPA) that were incorporated in the film via noncovalent interactions, became detached when the film was exposed to strongly acidic or alkaline solution. Oxidation of freshly formed films could significantly enhance their stability. The results therefore provide us with a better understanding of the stability of melanin-like films, and allow us to develop an effective strategy for constructing stable films.

  1. JaCVAM-organized international validation study of the in vivo rodent alkaline comet assay for detection of genotoxic carcinogens: II. Summary of definitive validation study results.

    PubMed

    Uno, Yoshifumi; Kojima, Hajime; Omori, Takashi; Corvi, Raffaella; Honma, Masamistu; Schechtman, Leonard M; Tice, Raymond R; Beevers, Carol; De Boeck, Marlies; Burlinson, Brian; Hobbs, Cheryl A; Kitamoto, Sachiko; Kraynak, Andrew R; McNamee, James; Nakagawa, Yuzuki; Pant, Kamala; Plappert-Helbig, Ulla; Priestley, Catherine; Takasawa, Hironao; Wada, Kunio; Wirnitzer, Uta; Asano, Norihide; Escobar, Patricia A; Lovell, David; Morita, Takeshi; Nakajima, Madoka; Ohno, Yasuo; Hayashi, Makoto

    2015-07-01

    The in vivo rodent alkaline comet assay (comet assay) is used internationally to investigate the in vivo genotoxic potential of test chemicals. This assay, however, has not previously been formally validated. The Japanese Center for the Validation of Alternative Methods (JaCVAM), with the cooperation of the U.S. NTP Interagency Center for the Evaluation of Alternative Toxicological Methods (NICEATM)/the Interagency Coordinating Committee on the Validation of Alternative Methods (ICCVAM), the European Centre for the Validation of Alternative Methods (ECVAM), and the Japanese Environmental Mutagen Society/Mammalian Mutagenesis Study Group (JEMS/MMS), organized an international validation study to evaluate the reliability and relevance of the assay for identifying genotoxic carcinogens, using liver and stomach as target organs. The ultimate goal of this exercise was to establish an Organisation for Economic Co-operation and Development (OECD) test guideline. The study protocol was optimized in the pre-validation studies, and then the definitive (4th phase) validation study was conducted in two steps. In the 1st step, assay reproducibility was confirmed among laboratories using four coded reference chemicals and the positive control ethyl methanesulfonate. In the 2nd step, the predictive capability was investigated using 40 coded chemicals with known genotoxic and carcinogenic activity (i.e., genotoxic carcinogens, genotoxic non-carcinogens, non-genotoxic carcinogens, and non-genotoxic non-carcinogens). Based on the results obtained, the in vivo comet assay is concluded to be highly capable of identifying genotoxic chemicals and therefore can serve as a reliable predictor of rodent carcinogenicity.

  2. Ethylene Inhibits Root Elongation during Alkaline Stress through AUXIN1 and Associated Changes in Auxin Accumulation1

    PubMed Central

    Li, Juan; Xu, Heng-Hao; Liu, Wen-Cheng; Zhang, Xiao-Wei

    2015-01-01

    Soil alkalinity causes major reductions in yield and quality of crops worldwide. The plant root is the first organ sensing soil alkalinity, which results in shorter primary roots. However, the mechanism underlying alkaline stress-mediated inhibition of root elongation remains to be further elucidated. Here, we report that alkaline conditions inhibit primary root elongation of Arabidopsis (Arabidopsis thaliana) seedlings by reducing cell division potential in the meristem zones and that ethylene signaling affects this process. The ethylene perception antagonist silver (Ag+) alleviated the inhibition of root elongation by alkaline stress. Moreover, the ethylene signaling mutants ethylene response1-3 (etr1-3), ethylene insensitive2 (ein2), and ein3-1 showed less reduction in root length under alkaline conditions, indicating a reduced sensitivity to alkalinity. Ethylene biosynthesis also was found to play a role in alkaline stress-mediated root inhibition; the ethylene overproducer1-1 mutant, which overproduces ethylene because of increased stability of 1-AMINOCYCLOPROPANE-1-CARBOXYLIC ACID SYNTHASE5, was hypersensitive to alkaline stress. In addition, the ethylene biosynthesis inhibitor cobalt (Co2+) suppressed alkaline stress-mediated inhibition of root elongation. We further found that alkaline stress caused an increase in auxin levels by promoting expression of auxin biosynthesis-related genes, but the increase in auxin levels was reduced in the roots of the etr1-3 and ein3-1 mutants and in Ag+/Co2+-treated wild-type plants. Additional genetic and physiological data showed that AUXIN1 (AUX1) was involved in alkaline stress-mediated inhibition of root elongation. Taken together, our results reveal that ethylene modulates alkaline stress-mediated inhibition of root growth by increasing auxin accumulation by stimulating the expression of AUX1 and auxin biosynthesis-related genes. PMID:26109425

  3. The sulphate-reduction alkalinity pump tested

    NASA Astrophysics Data System (ADS)

    Meister, Patrick; Petrishcheva, Elena

    2016-04-01

    Carbonate precipitation has been suggested to be induced by alkalinity increase during sulphate reduction under anoxic conditions. This mechanism may explain the formation of carbonate deposits in shallow marine environments, either within a redox stratified sediment inhabited by phototrophic microbial mats or in shallow water within the photic zone where sulphidic water is upwelling onto the shelf. The alkalinity pump may work as long as the sulphide is not reoxidized to sulphate, a process that would acidify the surrounding. The alkalinity effect of sulphate reduction was recently tested by Aloisi (2008) for microbial mats using a model approach. He found that sulphate reduction does not significantly increase or even decrease carbonate saturation and is unlikely to have played a significant role through Earth history. The model considers many environmental factors, including the effect of carbonate precipitation itself on the carbonate equilbrium and on the alkalinity. We used a modified version of Aloisi's (2008) model to simulate the saturation states of aragonite, calcite and dolomite without the effects of carbonate precipitation. This is necessary to evaluate the effect of microbial metabolisms exclusively on carbonate saturation, since carbonate precipitation is only the consequence, but not the cause of oversaturation. First results show that the saturation state is increased in the zone of phototrophic CO2 uptake. In contrast, the saturation state is strongly decreased in the zone where dissolved oxygen overlaps with dissolved sulphide. Aerobic sulphide oxidation consumes most of the HS- and dissipates most of the alkalinity produced in the sulphate reduction zone below. Hence, our results are consistent with the findings of Aloisi (2008), and they even more clearly show that sulphate reduction does not induce carbonate precipitation nor contributes to carbonate precipitation in combination with phototrophic CO2 uptake. The alkalinity effect of sulphate

  4. Alkalinity Enrichment Enhances Net Calcification of a Coral Reef Flat

    NASA Astrophysics Data System (ADS)

    Albright, R.; Caldeira, K.

    2015-12-01

    Ocean acidification is projected to shift reefs from a state of net accretion to one of net dissolution sometime this century. While retrospective studies show large-scale changes in coral calcification over the last several decades, it is not possible to unequivocally link these results to ocean acidification due to confounding factors of temperature and other environmental parameters. Here, we quantified the calcification response of a coral reef flat to alkalinity enrichment to test whether reef calcification increases when ocean chemistry is restored to near pre-industrial conditions. We used sodium hydroxide (NaOH) to increase the total alkalinity of seawater flowing over a reef flat, with the aim of increasing carbonate ion concentrations [CO32-] and the aragonite saturation state (Ωarag) to values that would have been attained under pre-industrial atmospheric pCO2 levels. We developed a dual tracer regression method to estimate alkalinity uptake (i.e., calcification) in response to alkalinity enrichment. This approach uses the change in ratios between a non-conservative tracer (alkalinity) and a conservative tracer (a non-reactive dye, Rhodamine WT) to assess the fraction of added alkalinity that is taken up by the reef as a result of an induced increase in calcification rate. Using this method, we estimate that an average of 17.3% ± 2.3% of the added alkalinity was taken up by the reef community. In providing results from the first seawater chemistry manipulation experiment performed on a natural coral reef community (without artificial confinement), we demonstrate that, upon increase of [CO32-] and Ωarag to near pre-industrial values, reef calcification increases. Thus, we conclude that, the impacts of ocean acidification are already being felt by coral reefs. This work is the culmination of years of work in the Caldeira lab at the Carnegie Institution for Science, involving many people including Jack Silverman, Kenny Schneider, and Jana Maclaren.

  5. Role of chemical composition in the enhanced catalytic activity of Pt-based alloyed ultrathin nanowires for the hydrogen oxidation reaction under alkaline conditions

    SciTech Connect

    Megan E. Scofield; Wong, Stanislaus S.; Zhou, Yuchen; Yue, Shiyu; Wang, Lei; Su, Dong; Tong, Xiao; Vukmirovic, Miomir B.; Adzic, Radoslav R.

    2016-05-11

    With the increased interest in the development of hydrogen fuel cells as a plausible alternative to internal combustion engines, recent work has focused on creating alkaline fuel cells (AFC), which employ an alkaline environment. Working in alkaline as opposed to acidic media yields a number of tangible benefits, including (i) the ability to use cheaper and plentiful precious-metal-free catalysts, due to their increased stability, (ii) a reduction in the amount of degradation and corrosion of Pt-based catalysts, and (iii) a longer operational lifetime for the overall fuel cell configuration. However, in the absence of Pt, no catalyst has achieved activities similar to those of Pt. Herein, we have synthesized a number of crystalline ultrathin PtM alloy nanowires (NWs) (M = Fe, Co, Ru, Cu, Au) in order to replace a portion of the costly Pt metal without compromising on activity while simultaneously adding in metals known to exhibit favorable synergistic ligand and strain effects with respect to the host lattice. In fact, our experiments confirm theoretical insights about a clear and correlative dependence between measured activity and chemical composition. We have conclusively demonstrated that our as-synthesized alloy NW catalysts yield improved hydrogen oxidation reaction (HOR) activities as compared with a commercial Pt standard as well as with our as-synthesized Pt NWs. The Pt7Ru3 NW system, in particular, quantitatively achieved an exchange current density of 0.493 mA/cm2, which is higher than the corresponding data for Pt NWs alone. In addition, the HOR activities follow the same expected trend as their calculated hydrogen binding energy (HBE) values, thereby confirming the critical importance and correlation of HBE with the observed activities.

  6. Role of chemical composition in the enhanced catalytic activity of Pt-based alloyed ultrathin nanowires for the hydrogen oxidation reaction under alkaline conditions

    DOE PAGES

    Megan E. Scofield; Wong, Stanislaus S.; Zhou, Yuchen; ...

    2016-05-11

    With the increased interest in the development of hydrogen fuel cells as a plausible alternative to internal combustion engines, recent work has focused on creating alkaline fuel cells (AFC), which employ an alkaline environment. Working in alkaline as opposed to acidic media yields a number of tangible benefits, including (i) the ability to use cheaper and plentiful precious-metal-free catalysts, due to their increased stability, (ii) a reduction in the amount of degradation and corrosion of Pt-based catalysts, and (iii) a longer operational lifetime for the overall fuel cell configuration. However, in the absence of Pt, no catalyst has achieved activitiesmore » similar to those of Pt. Herein, we have synthesized a number of crystalline ultrathin PtM alloy nanowires (NWs) (M = Fe, Co, Ru, Cu, Au) in order to replace a portion of the costly Pt metal without compromising on activity while simultaneously adding in metals known to exhibit favorable synergistic ligand and strain effects with respect to the host lattice. In fact, our experiments confirm theoretical insights about a clear and correlative dependence between measured activity and chemical composition. We have conclusively demonstrated that our as-synthesized alloy NW catalysts yield improved hydrogen oxidation reaction (HOR) activities as compared with a commercial Pt standard as well as with our as-synthesized Pt NWs. The Pt7Ru3 NW system, in particular, quantitatively achieved an exchange current density of 0.493 mA/cm2, which is higher than the corresponding data for Pt NWs alone. In addition, the HOR activities follow the same expected trend as their calculated hydrogen binding energy (HBE) values, thereby confirming the critical importance and correlation of HBE with the observed activities.« less

  7. Column leaching test to evaluate the use of alkaline industrial wastes to neutralize acid mine tailings

    SciTech Connect

    Doye, I.; Duchesne, J.

    2005-08-01

    Acid mine drainage is a serious environmental problem caused by the oxidation of sulfide minerals that releases highly acidic, sulfate, and metals-rich drainage. In this study, alkaline industrial wastes were mixed with acid mine tailings in order to obtain neutral conditions. A series of column leaching tests were performed to evaluate the behavior of reactive mine tailings amended with alkaline-additions under dynamic conditions. Column tests were conducted of oxidized mine tailings combined with cement kiln dust, red mud bauxite, and mixtures of cement kiln dust with red mud bauxite. The pH results show the addition of 10% of alkaline materials permits the maintenance of near neutral conditions. In the presence of 10% alkaline material, the concentration of toxic metals such as Al, Cu, Fe, Zn are significantly reduced as well as the number of viable cells (Thiobacillus ferrooxidans) compared to control samples.

  8. The alkaline and alkaline-carbonatite magmatism from Southern Brazil

    NASA Astrophysics Data System (ADS)

    Ruberti, E.; Gomes, C. D. B.; Comin-Chiaramonti, P.

    2015-12-01

    Early to Late Cretaceous lasting to Paleocene alkaline magmatism from southern Brazil is found associated with major extensional structural features in and around the Paraná Basin and grouped into various provinces on the basis of several data. Magmatism is variable in size, mode of occurrence and composition. The alkaline rocks are dominantly potassic, a few occurrences showing sodic affinity. The more abundant silicate rocks are evolved undersaturated to saturated in silica syenites, displaying large variation in igneous forms. Less evolved types are restricted to subvolcanic environments and outcrops of effusive suites occur rarely. Cumulatic mafic and ultramafic rock types are very common, particularly in the alkali-carbonatitic complexes. Carbonatite bodies are represented by Ca-carbonatites and Mg-carbonatites and more scarcely by Fe-carbonatites. Available radiometric ages for the alkaline rocks fit on three main chronological groups: around 130 Ma, subcoveal with the Early Cretaceous flood tholeiites of the Paraná Basin, 100-110 Ma and 80-90 Ma (Late Cretaceous). The alkaline magmatism also extends into Paleocene times, as indicated by ages from some volcanic lavas. Geochemically, alkaline potassic and sodic rock types are distinguished by their negative and positive Nb-Ta anomalies, respectively. Negative spikes in Nb-Ta are also a feature common to the associated tholeiitic rocks. Sr-Nd-Pb systematics confirm the contribution of both HIMU and EMI mantle components in the formation of the alkaline rocks. Notably, Early and Late Cretaceous carbonatites have the same isotopic Sr-Nd initial ratios of the associated alkaline rocks. C-O isotopic Sr-Nd isotopic ratios indicate typical mantle signature for some carbonatites and the influence of post-magmatic processes in others. Immiscibility of liquids of phonolitic composition, derived from mafic alkaline parental magmas, has been responsible for the origin of the carbonatites. Close association of alkaline

  9. A new cementless total hip arthroplasty with bioactive titanium porous-coating by alkaline and heat treatment: average 4.8-year results.

    PubMed

    Kawanabe, Keiichi; Ise, Kentaro; Goto, Koji; Akiyama, Haruhiko; Nakamura, Takashi; Kaneuji, Ayumi; Sugimori, Tanzo; Matsumoto, Tadami

    2009-07-01

    A method has been developed for creating a bioactive coating on titanium by alkaline and heat treatment, and shown that it forms a thin layer of hydroxyapatite (HA) on the surface of implants when soaked in simulated body fluid. A series of 70 cementless primary total hip arthroplasties using this coating technique on a porous titanium surface was performed, and followed up the patients for a mean period of 4.8 years. There were no instances of loosening or revision, or formation of a reactive line on the porous coating. Although radiography just after operation showed a gap between the host bone and the socket in over 70% of cases, all the gaps disappeared within a year, indicating the good osteoconduction provided by the coating. Alkaline-heat treatment of titanium to provide a thin HA coating has several advantages over plasma-spraying, including no degeneration or absorption of the HA coating, simplicity of the manufacturing process, and cost effectiveness. In addition, this method allows homogeneous deposition of bone-like apatite within a porous implant. Although this was a relatively short-term study, treatment that creates a bioactive surface on titanium and titanium alloy implants has considerable promise for clinical application.

  10. Surfactant-enhanced alkaline flooding field project

    SciTech Connect

    French, T.R.

    1991-10-01

    The Tucker sand of Helper (KS) field is a candidate for surfactant-enhanced alkaline flooding. The geology of the Helper site is typical of many DOE Class I reservoirs. The Tucker sand of Helper field was deposited in a fluvial dominated deltaic environment. Helper oil can be mobilized with either chemical system 2 or chemical system 3, as described in this report. Oil fields in the Gulf Coast region are also good candidates for surfactant-enhanced alkaline flooding. The results from laboratory tests conducted in Berea sandstone cores with oil brine from Helper (KS) field are encouraging. The crude oil is viscous and non-acidic and, yet, was mobilized by the chemical formulations described in this report. Significant amounts of the oil were mobilized under simulated reservoir conditions. The results in Berea sandstone cores were encouraging and should be verified by tests with field core. Consumption of alkali, measured with field core, was very low. Surfactant loss appeared to be acceptable. Despite the good potential for mobilization of Helper oil, certain reservoir characteristics such as low permeability, compartmentalization, and shallow depth place constraints on applications of any chemical system in the Tucker sand. These constraints are typical of many DOE Class I reservoirs. Although Hepler field is not a perfect reservoir in which to apply surfactant- enhanced alkaline flooding, Hepler oil is particularly amenable to mobilization by surfactant-enhanced alkaline systems. A field test is recommended, dependent upon final evaluation of well logs and cores from the proposed pilot area. 14 refs., 21 figs., 10 tabs.

  11. [Leucocyte alkaline phosphatase in normal and pathological pregnancy (author's transl)].

    PubMed

    Stark, K H; Zaki, I; Sobolewski, K

    1981-01-01

    The activities of leucocyte alkaline phosphatase were determined in 511 patients with normal and pathological pregnancy. Mean values were compared and the enzyme followed up, and the conclusion was drawn that leucocyte alkaline phosphatase was no safe indicator of foetal condition. No direct relationship were found to exist between leucocyte alkaline phosphatase, total oestrogens, HSAP, HLAP, HPL, and oxytocinase.

  12. Improved gas chromatographic method for determination of daminozide by alkaline hydrolysis and 2-nitrobenzaldehyde derivatization and survey results of daminozide in agricultural products.

    PubMed

    Steinbrecher, K; Saxton, W L; Oehler, G A

    1990-01-01

    An improved method was developed for the quantitative determination of daminozide. This new method combines the alkaline hydrolysis and distillation steps of the PAM II method for daminozide with the derivatization, cleanup, and gas chromatographic determination steps of the Wright method for unsymmetrical dimethyl hydrazine (UDMH). The minimum detectable level is 0.05 ppm. Recoveries range from 85 to 110% when daminozide is added at 0.1 to 1.0 ppm, and are generally 40% at the 0.05 ppm level. A variety of domestic and imported products were analyzed by this improved method and daminozide was detected in 33 of the 98 samples analyzed. Levels detected ranged from a trace amount to 0.80 ppm. The identity of UDMH hydrazone was confirmed by mass spectrometry in many samples, thus confirming the presence of daminozide. Two samples containing daminozide were analyzed independently by a second laboratory and the findings were closely duplicated.

  13. Anodes for alkaline electrolysis

    DOEpatents

    Soloveichik, Grigorii Lev

    2011-02-01

    A method of making an anode for alkaline electrolysis cells includes adsorption of precursor material on a carbonaceous material, conversion of the precursor material to hydroxide form and conversion of precursor material from hydroxide form to oxy-hydroxide form within the alkaline electrolysis cell.

  14. Zinc electrode in alkaline electrolyte

    SciTech Connect

    McBreen, J.

    1995-12-31

    The zinc electrode in alkaline electrolyte is unusual in that supersaturated zincate solutions can form during discharge and spongy or mossy zinc deposits can form on charge at low overvoltages. The effect of additives on regular pasted ZnO electrodes and calcium zincate electrodes is discussed. The paper also reports on in situ x-ray absorption (XAS) results on mossy zinc deposits.

  15. Temperature dependence of the absorbance of alkaline solutions of 4-nitrophenyl phosphate--a potential source of error in the measurement of alkaline phosphatase activity.

    PubMed

    Burtis, C A; Seibert, L E; Baird, M A; Sampson, E J

    1977-09-01

    The absorbance of an alkaline solution of 4-nitrophenyl phosphate is a function of temperature. Quantitative evaluation of this phenomenon indicates that it (a) depends on the concentration of the compound and is independent of source, buffer concentration, and pH above 9.0; (b) is reversible; (c) is not a result of alkaline hydrolysis or 4-nitrophenol contamination; and (d) correlates with a temperature-induced shift of its absorbance spectrum. The phenomenon may represent a potential analytical problem in methods for alkaline phosphatase in which this compound is the substrate. If thermal equilibrium is not reached and maintained during an alkaline phosphatase assay, the thermochromic response will be included in the measured rate. The magnitude of this error depends on the thermal response and control characteristics of each particular instrument and the reaction conditions under which such an analysis is performed.

  16. Conditioning matrices from high level waste resulting from pyrochemical processing in fluorine salt

    SciTech Connect

    Grandjean, Agnes; Advocat, Thierry; Bousquet, Nicolas; Jegou, Christophe

    2007-07-01

    Separating the actinides from the fission products through reductive extraction by aluminium in a LiF/AlF{sub 3} medium is a process investigated for pyrometallurgical reprocessing of spent fuel. The process involves separation by reductive salt-metal extraction. After dissolving the fuel or the transmutation target in a salt bath, the noble metal fission products are first extracted by contacting them with a slightly reducing metal. After extracting the metal fission products, then the actinides are selectively separated from the remaining fission products. In this hypothesis, all the unrecoverable fission products would be conditioned as fluorides. Therefore, this process will generate first a metallic waste containing the 'reducible' fission products (Pd, Mo, Ru, Rh, Tc, etc.) and a fluorine waste containing alkali-metal, alkaline-earth and rare earth fission products. Immobilization of these wastes in classical borosilicate glasses is not feasible due to the very low solubility of noble metals, and of fluoride in these hosts. Alternative candidates have therefore been developed including silicate glass/ceramic system for fluoride fission products and metallic ones for noble metal fission products. These waste-forms were evaluated for their confinement properties like homogeneity, waste loading, volatility during the elaboration process, chemical durability, etc. using appropriate techniques. (authors)

  17. Catalysis and stability of an alkaline protease from a haloalkaliphilic bacterium under non-aqueous conditions as a function of pH, salt and temperature.

    PubMed

    Pandey, Sandeep; Rakholiya, Kalpna D; Raval, Vikram H; Singh, Satya P

    2012-09-01

    A haloalkaliphilic bacterium, isolated from Coastal Gujarat (India) was identified as Oceanobacillus sp. (GQ162111) based on 16S rRNA gene sequence. The organism grew and secreted extra cellular protease in presence of various organic solvents. At 30% (v/v) concentration of hexane, heptane, isooctane, dodecane and decane, significant growth and protease production was evident. The alkaline protease was purified in a single step on phenyl sepharose 6 FF with 28% yield. The molecular mass as judged by SDS-PAGE was 30 kDa. The temperature optimum of protease was 50°C and the enzyme retained 70% activity in 10% (v/v) isooctane. Effect of salt and pH was investigated in combination to assess the effect of isooctane. In organic solvents, the enzyme was considerably active at pH 8-11, with optimum activity at pH 10. Salt at 2 M was optimum for activity and enzyme maintained significant stability up to 18 h even at 3 M salt concentration. Patters of growth, protease production, catalysis and stability of the enzyme are presented. The study resumes significance as limited information is available on the interaction of haloalkaliphilic bacteria and their enzymes with organic solvents.

  18. A study of photosynthetic biogas upgrading based on a high rate algal pond under alkaline conditions: Influence of the illumination regime.

    PubMed

    Franco-Morgado, Mariana; Alcántara, Cynthia; Noyola, Adalberto; Muñoz, Raúl; González-Sánchez, Armando

    2017-03-20

    Microalgal-bacterial processes have emerged as environmental friendly systems for the cost-effective treatment of anaerobic effluents such as biogas and nutrients-laden digestates. Environmental parameters such as temperature, irradiation, nutrient concentration and pH effect the performance of the systems. In this paper, the potential of a microalgal-bacterial photobioreactor operated under high pH (≈9.5) and high alkalinity to convert biogas into biomethane was evaluated. The influence of the illumination regime (continuous light supply vs 12h/12h light/dark cycles) on the synthetic biogas upgrading efficiency, biomass productivity and nutrient removal efficiency was assessed in a High-Rate Algal Pond interconnected to a biogas absorption bubble column. No significant differences in the removal efficiency of CO2 and H2S (91.5±2% and 99.5%±0.5, respectively) were recorded regardless of the illumination regime. The high fluctuations of the dissolved oxygen concentration during operation under light/dark cycles allowed to evaluate the specific growth rate and the specific partial degradation rate of the microalgae biomass by photosynthesis and respiration, respectively. The respiration reduced the net microalgae biomass productivity under light/dark cycles compared with process operation under the continuous light supply.

  19. Preliminary results, Central Gneiss Complex of the Coast Range batholith, southeastern Alaska: the roots of a high-K, calc-alkaline arc?

    USGS Publications Warehouse

    Barker, F.; Arth, Joseph G.

    1984-01-01

    The Central Gneiss Complex (CGC) of the Coast Range batholith is the oldest unit of the batholith east of Ketchikan, Alaska, being dated by the zircon UPb method (by T.W. Stern) at 128-140 Ma. Heterogeneous, layered, commonly migmatitic, orthogneiss of hornblende-biotite quartz diorite, tonalite, quartz monzodiorite and granodiorite compositions (IUGS terminology) form the major part of the CGC. These gneisses show a range of 50-65% SiO2 and are high in Al2O3 (c. 15-19%), K2O (1.5-4%) and Sr (800-900 ppm). Most major elements show coherent, typically magmatic trends with SiO2. La and Rb show maxima at ??? 58% SiO2. Initial 87Sr/86Sr ratios are relatively high and range from 0.7052 to 0.7066. Wallrocks of the CGC are mostly metagraywacke, pelite and metavolcanic rocks at amphibolite facies; they are geochemically dissimilar to the CGC. Major and minor elements of the CGC are very similar to those of high-K orogenic, calc-alkaline andesitic suites. The CGC may have formed largely by fractionation of mantle-derived, high AlKSr basaltic liquid in an ascending diapir, having hornblende, plagioclase, and biotite as major precipitating phases. The CGC probably represents the plutonic equivalent of a continental-margin or Andean arc that formed when the Taku terrane of the Insular belt on the west collided with the previously emplaced (but also allochthonous) Stikine terrane on the east in Late Jurassic or Early Cretaceous time. ?? 1984.

  20. HANDBOOK: GUIDANCE ON SETTING PERMIT CONDITIONS AND REPORTING TRIAL BURN RESULTS

    EPA Science Inventory

    This Handbook provides guidance for establishing operational conditions for incinerators. he document provides a means for state and local agencies to achieve a level of consistency in setting permit conditions that will result in establishment of more uniform permit conditions n...

  1. Long-term alkalinity decrease and acidification of estuaries in northwestern Gulf of Mexico.

    PubMed

    Hu, Xinping; Pollack, Jennifer Beseres; McCutcheon, Melissa R; Montagna, Paul A; Ouyang, Zhangxian

    2015-03-17

    More than four decades of alkalinity and pH data (late 1960s to 2010) from coastal bays along the northwestern Gulf of Mexico were analyzed for temporal changes across a climatic gradient of decreasing rainfall and freshwater inflow, from northeast to southwest. The majority (16 out of 27) of these bays (including coastal waters) showed a long-term reduction in alkalinity at a rate of 3.0-21.6 μM yr(-1). Twenty-two bays exhibited pH decreases at a rate of 0.0014-0.0180 yr(-1). In contrast, a northernmost coastal bay exhibited increases in both alkalinity and pH. Overall, the two rates showed a significant positive correlation, indicating that most of these bays, especially those at lower latitudes, have been experiencing long-term acidification. The observed alkalinity decrease may be caused by reduced riverine alkalinity export, a result of precipitation decline under drought conditions, and freshwater diversion for human consumption, as well as calcification in these bays. A decrease in alkalinity inventory and accompanying acidification may have negative impacts on shellfish production in these waters. In addition, subsequent reduction in alkalinity export from these bays to the adjacent coastal ocean may also decrease the buffer capacity of the latter against future acidification.

  2. 49 CFR 236.528 - Restrictive condition resulting from open hand-operated switch; requirement.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Restrictive condition resulting from open hand... Instructions; Roadway § 236.528 Restrictive condition resulting from open hand-operated switch; requirement. When a facing point hand-operated switch is open one-fourth inch or more, a trailing point...

  3. 49 CFR 236.528 - Restrictive condition resulting from open hand-operated switch; requirement.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Restrictive condition resulting from open hand... Instructions; Roadway § 236.528 Restrictive condition resulting from open hand-operated switch; requirement. When a facing point hand-operated switch is open one-fourth inch or more, a trailing point...

  4. 49 CFR 236.528 - Restrictive condition resulting from open hand-operated switch; requirement.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Restrictive condition resulting from open hand... Instructions; Roadway § 236.528 Restrictive condition resulting from open hand-operated switch; requirement. When a facing point hand-operated switch is open one-fourth inch or more, a trailing point...

  5. Release of bound procyanidins from cranberry pomace by alkaline hydrolysis.

    PubMed

    White, Brittany L; Howard, Luke R; Prior, Ronald L

    2010-07-14

    Procyanidins in plant products are present as extractable or unextractable/bound forms. We optimized alkaline hydrolysis conditions to liberate procyanidins and depolymerize polymers from dried cranberry pomace. Alkaline extracts were neutralized (pH 6-7) and then procyanidins were extracted with ethyl acetate and analyzed by normal phase high performance liquid chromatography. Alkaline hydrolysis resulted in an increase in low molecular weight procyanidins, and the increase was greater at higher temperature, short time combinations. The most procyanidins (DP1-DP3) were extracted at 60 degrees C for 15 min with each concentration of NaOH. When compared to conventional extraction using homogenization with acetone/water/acetic acid (70:29.5:0.5 v/v/v), treatment with NaOH increased procyanidin oligomer extraction by 3.8-14.9-fold, with the greatest increase being DP1 (14.9x) and A-type DP2 (8.4x) procyanidins. Alkaline treatment of the residue remaining after conventional extraction resulted in further procyanidin extraction, indicating that procyanidins are not fully extracted by conventional extraction methods.

  6. Mammalian intestinal alkaline phosphatase acts as highly active exopolyphosphatase.

    PubMed

    Lorenz, B; Schröder, H C

    2001-06-11

    Recent results revealed that inorganic polyphosphates (polyP), being energy-rich linear polymers of orthophosphate residues known from bacteria and yeast, also exist in higher eukaryotes. However, the enzymatic basis of their metabolism especially in mammalian cells is still uncertain. Here we demonstrate for the first time that alkaline phosphatase from calf intestine (CIAP) is able to cleave polyP molecules up to a chain length of about 800. The enzyme acts as an exopolyphosphatase degrading polyP in a processive manner. The pH optimum is in the alkaline range. Divalent cations are not required for catalytic activity but inhibit the degradation of polyP. The rate of hydrolysis of short-chain polyP by CIAP is comparable to that of the standard alkaline phosphatase (AP) substrate p-nitrophenyl phosphate. The specific activity of the enzyme decreases with increasing chain length of the polymer both in the alkaline and in the neutral pH range. The K(m) of the enzyme also decreases with increasing chain length. The mammalian tissue non-specific isoform of AP was not able to hydrolyze polyP under the conditions applied while the placental-type AP and the bacterial (Escherichia coli) AP displayed polyP-degrading activity.

  7. Existence Result for the Kinetic Neutron Transport Problem with a General Albedo Boundary Condition

    NASA Astrophysics Data System (ADS)

    Sanchez, Richard; Bourhrara, Lahbib

    2011-09-01

    We present an existence result for the kinetic neutron transport equation with a general albedo boundary condition. The proof is constructive in the sense that we build a sequence that converges to the solution of the problem by iterating on the albedo term. Both nonhomogeneous and albedo boundary conditions are studied.

  8. The effect of alkaline additives on the performance of surfactant systems designed to recover light oils

    SciTech Connect

    French, T.R.; Josephson, C.B.; Evans, D.B.

    1991-02-01

    Surfactant flooding is flexible because of the ability to optimize formulations for a wide range of reservoir conditions and crude oil types. The objective for this work was to determine if the addition of alkaline additives will allow the design of surfactant formulations that are effective for the recovery of crude oil, while, at the same time, maintaining the surfactant concentration at a much lower level than has previously been used for micellar flooding. Specifically, the focus of the work was on light, midcontinent crudes that typically have very low acid contents. These oils are typical of much of the midcontinent resource. The positive effect of alkaline additives on the phase behavior of the surfactant formulations and acidic crude oils is well known. The extension to nonacidic and slightly acidic oils is not obvious. Three crude oils, a variety of commercial surfactants, and several alkaline additives were tested. The oils had acid numbers that ranged from 0.13, which is quite low, to less than 0.01 mg KOH/g of oil. Alkaline additives were found to be very effective in recovering Delaware-Childers (OK) oil at elevated temperatures, but much less effective at reservoir temperatures. Alkaline additives were very effective with Teapot Dome (WY) oil. With Teapot Dome oil, surfactant/alkali systems produced ultralow IFT values and recovered 60% of the residual oil that remained after waterflooding. The effect of alkaline additives on recovering Hepler (KS) oil was minimal. The results of this work indicate that alkaline additives do have merit for use in surfactant flooding of low acid crude oils; however, no universal statement about applicability can be made. Each oil behaves differently, with this treatment, and the effect of alkaline additives must be determined (at reservoir conditions) for each oil. 23 refs., 13 figs., 3 tabs.

  9. Experimental results for improving the matrix condition using a hybrid optical system.

    PubMed

    Klapp, Iftach; Mendlovic, David

    2012-03-01

    We present preliminary experimental results for implementing the "blurred trajectories" method on three parallel optics (PO) systems. The "main" system and "auxiliary" optics were simple laboratory graded lenses attached to an iris diaphragm. When applying the blurred trajectories method we first show an improvement in the matrix condition, as the matrix condition number decreased in a range of factors of 3 to 418 relative to the main system. Following that, image restoration by weak regularization was performed so that the system matrix condition dominated the restoration process. It was shown that the restoration results of the PO are better than those of the main system and the auxiliary optics separately. In addition, the quality of the restoration follows the system's matrix condition. The improvement in the matrix condition achieved by the PO system improved the immunity to detection noise. Finally, a comparison to Wiener filtering restoration shows that it is also generally inferior to the proposed method.

  10. Low-heat, mild alkaline pretreatment of switchgrass for anaerobic digestion.

    PubMed

    Jin, Guang; Bierma, Tom; Walker, Paul M

    2014-01-01

    This study examines the effectiveness of alkaline pretreatment under mild heat conditions (100°C or 212°F) on the anaerobic co-digestion of switchgrass. The effects of alkaline concentration, types of alkaline, heating time and rinsing were evaluated. In addition to batch studies, continuous-feed studies were performed in triplicate to identify potential digester operational problems caused by switchgrass co-digestion while accounting for uncertainty due to digester variability. Few studies have examined anaerobic digestion of switchgrass or the effects of mild heating to enhance alkaline pretreatment prior to biomass digestion. Results indicate that pretreatment can significantly enhance digestion of coarse-ground (≤ 0.78 cm particle size) switchgrass. Energy conversion efficiency as high as 63% was observed, and was comparable or superior to fine-grinding as a pretreatment method. The optimal NaOH concentration was found to be 5.5% (wt/wt alkaline/biomass) with a 91.7% moisture level. No evidence of operational problems such as solids build-up, poor mixing, or floating materials were observed. These results suggest the use of waste heat from a generator could reduce the concentration of alkaline required to adequately pretreat lignocellulosic feedstock prior to anaerobic digestion.

  11. [Effects of exogenous spermidine on mitochondrial function of tomato seedling roots under salinity-alkalinity stress].

    PubMed

    Pan, Xiong-bo; Xiang, Li-xia; Hu, Xiao-hui; Ren, Wen-qi; Zhang, Li; Ni, Xin-xin

    2016-02-01

    Two cultivars of tomato (Solanum lycopersicum, cvs. 'Jinpengchaoguan' and 'Zhongza No. 9', with the former being more tolerant to saline-alkaline stress) seedlings grown hydroponically were subjected to salinity-alkalinity stress condition (NaCl: Na2SO4:NaHCO3:Na2CO3 = 1:9:9:1) without or with foliar application of 0.25 mmol . L-1 spermidine (Spd), and the root morphology and physiological characteristics of mitochondrial membrane were analyzed 8 days after treatment, to explore the protective effects of exogenous Spd on mitochondrial function in tomato roots under salinity-alkalinity stress. The results showed that the salinity-alkalinity stress increased the concentrations of both mitochondrial H2O2 and MDA as well as the mitochondrial membrane permeability in the roots of the two cultivars, while it decreased the mitochondrial membrane fluidity, membrane potential, Cyt c/a and H+-ATPase activity, which impaired the mitochondria and therefore inhibited the root growth; and these effects were more obvious in 'Zhongza No. 9' than in 'Jinpengechaoguan'. Under the salinity-alkalinity stress, foliar application Spd could effectively decrease the concentrations of mitochondrial H2O2 and MDA and mitochondrial membrane permeability, while increased the mitochondrial membrane fluidity, membrane potential, Cyt c/a and H+-ATPase activity. These results suggested that exogenous Spd could effectively mitigate the damage on mitochondria induced by salinity-alkalinity stress, and the alleviation effect was more obvious in 'Zhongza No. 9' than in 'Jinpengchaoguan'.

  12. Energetics of Amino Acid Synthesis in Alkaline Hydrothermal Environments.

    PubMed

    Kitadai, Norio

    2015-12-01

    Alkaline hydrothermal systems have received considerable attention as candidates for the origin and evolution of life on the primitive Earth. Nevertheless, sufficient information has not yet been obtained for the thermodynamic properties of amino acids, which are necessary components for life, at high temperatures and alkaline pH. These properties were estimated using experimental high-temperature volume and heat capacity data reported in the literature for several amino acids, together with correlation algorithms and the revised Helgeson-Kirkham-Flowers (HKF) equations of state. This approach enabled determination of a complete set of the standard molal thermodynamic data and the revised HKF parameters for the 20 protein amino acids in their zwitterionic and ionization states. The obtained dataset was then used to evaluate the energetics of amino acid syntheses from simple inorganic precursors (CO2, H2, NH3 and H2S) in a simulated alkaline hydrothermal system on the Hadean Earth. Results show that mixing between CO2-rich seawater and the H2-rich hydrothermal fluid can produce energetically favorable conditions for amino acid syntheses, particularly in the lower-temperature region of such systems. Together with data related to the pH and temperature dependences of the energetics of amino acid polymerizations presented in earlier reports, these results suggest the following. Hadean alkaline hydrothermal settings, where steep pH and temperature gradients may have existed between cool, slightly acidic Hadean ocean water and hot, alkaline hydrothermal fluids at the vent-ocean interface, may be energetically the most suitable environment for the synthesis and polymerization of amino acids.

  13. Energetics of Amino Acid Synthesis in Alkaline Hydrothermal Environments

    NASA Astrophysics Data System (ADS)

    Kitadai, Norio

    2015-12-01

    Alkaline hydrothermal systems have received considerable attention as candidates for the origin and evolution of life on the primitive Earth. Nevertheless, sufficient information has not yet been obtained for the thermodynamic properties of amino acids, which are necessary components for life, at high temperatures and alkaline pH. These properties were estimated using experimental high-temperature volume and heat capacity data reported in the literature for several amino acids, together with correlation algorithms and the revised Helgeson-Kirkham-Flowers (HKF) equations of state. This approach enabled determination of a complete set of the standard molal thermodynamic data and the revised HKF parameters for the 20 protein amino acids in their zwitterionic and ionization states. The obtained dataset was then used to evaluate the energetics of amino acid syntheses from simple inorganic precursors (CO2, H2, NH3 and H2S) in a simulated alkaline hydrothermal system on the Hadean Earth. Results show that mixing between CO2-rich seawater and the H2-rich hydrothermal fluid can produce energetically favorable conditions for amino acid syntheses, particularly in the lower-temperature region of such systems. Together with data related to the pH and temperature dependences of the energetics of amino acid polymerizations presented in earlier reports, these results suggest the following. Hadean alkaline hydrothermal settings, where steep pH and temperature gradients may have existed between cool, slightly acidic Hadean ocean water and hot, alkaline hydrothermal fluids at the vent-ocean interface, may be energetically the most suitable environment for the synthesis and polymerization of amino acids.

  14. Chemical degradation mechanisms of membranes for alkaline membrane fuel cells

    SciTech Connect

    Choe, Yoong-Kee; Henson, Neil J.; Kim, Yu Seung

    2015-12-31

    Chemical degradation mechanisms of membranes for alkaline membrane fuel cells have been investigated using density functional theory (DFT). We have elucidated that the aryl-ether moiety of membranes is one of the weakest site against attack of hydroxide ions. The results of DFT calculations for hydroxide initiated aryl-ether cleavage indicated that the aryl-ether cleavage occurred prior to degradation of cationic functional group. Such a weak nature of the aryl-ether group arises from the electron deficiency of the aryl group as well as the low bond dissociation energy. The DFT results suggests that removal of the aryl-ether group in the membrane should enhance the stability of membranes under alkaline conditions. In fact, an ether fee poly(phenylene) membrane exhibits excellent stability against the attack from hydroxide ions.

  15. Alkaline Water and Longevity: A Murine Study

    PubMed Central

    Magro, Massimiliano; Corain, Livio; Ferro, Silvia; Baratella, Davide; Bonaiuto, Emanuela; Terzo, Milo; Corraducci, Vittorino; Salmaso, Luigi; Vianello, Fabio

    2016-01-01

    The biological effect of alkaline water consumption is object of controversy. The present paper presents a 3-year survival study on a population of 150 mice, and the data were analyzed with accelerated failure time (AFT) model. Starting from the second year of life, nonparametric survival plots suggest that mice watered with alkaline water showed a better survival than control mice. Interestingly, statistical analysis revealed that alkaline water provides higher longevity in terms of “deceleration aging factor” as it increases the survival functions when compared with control group; namely, animals belonging to the population treated with alkaline water resulted in a longer lifespan. Histological examination of mice kidneys, intestine, heart, liver, and brain revealed that no significant differences emerged among the three groups indicating that no specific pathology resulted correlated with the consumption of alkaline water. These results provide an informative and quantitative summary of survival data as a function of watering with alkaline water of long-lived mouse models. PMID:27340414

  16. Ejector nozzle test results at simulated flight conditions for an advanced supersonic transport propulsion system

    NASA Technical Reports Server (NTRS)

    Nelson, D. P.; Bresnahan, D. L.

    1983-01-01

    Results are presented of wind tunnel tests conducted to verify the performance improvements of a refined ejector nozzle design for advanced supersonic transport propulsion systems. The analysis of results obtained at simulated engine operating conditions is emphasized. Tests were conducted with models of approximately 1/10th scale which were configured to simulate nozzle operation at takeoff, subsonic cruise, transonic cruise, and supersonic cruise. Transonic cruise operation was not a consideration during the nozzle design phase, although an evaluation at this condition was later conducted. Test results, characterized by thrust and flow coefficients, are given for a range of nozzle pressure ratios, emphasizing the thrust performance at the engine operating conditions predicted for each flight Mach number. The results indicate that nozzle performance goals were met or closely approximated at takeoff and supersonic cruise, while subsonic cruise performance was within 2.3 percent of the goal with further improvement possible.

  17. Re-epithelialization of the Buccal Mucosa after Alkaline Chemical Injury.

    PubMed

    Takaichi, Saneyuki; Muramatsu, Takashi; Lee, Jong-Min; Jung, Han-Sung; Shinozaki, Naoshi; Katakura, Akira; Yamane, Gen-Yuki

    2014-01-01

    Alkaline conditions in the oral cavity may be caused by a variety of stimuli, including tobacco products, antacids, alkaline drinking water and bicarbonate toothpaste. However, the effects of an alkaline pH on the oral mucosa had not been elucidated. The purpose of this study was to investigate how basal keratinocytes are actively involved in re-epithelialization after alkaline chemical injury. We generated epithelial defects in the oral mucosa of mice by applying an alkaline chemical, and the localization of cytokeratin 13, cytokeratin 14, PCNA and p63 was investigated during the re-epithelialization process. PCNA- and p63-positive staining was seen in basal cells covering the wound surface at 1 day after the chemical injury. Cytokeratin 14-positive and PCNA-negative basal keratinocytes were localized in a few layers of the wound epithelium during epithelial outgrowth. Cytokeratin 14-positive and PCNA-positive basal keratinocytes, indicating proliferation, were localized over the entire layer of the epithelium at the wound margin. These results imply that basal keratinocytes at the wound margin migrate to the wound surface, provoke differentiation and keratinization during epithelial outgrowth and that epithelial cells are supplied from the wound margin to the epithelial outgrowth after alkaline chemical injury.

  18. Repeated Activation of a CS-US-Contingency Memory Results in Sustained Conditioned Responding

    PubMed Central

    Joos, Els; Vansteenwegen, Debora; Vervliet, Bram; Hermans, Dirk

    2013-01-01

    Individuals seem to differ in conditionability, i.e., the ease by which the contingent presentation of two stimuli will lead to a conditioned response. In contemporary learning theory, individual differences in the etiology and maintenance of anxiety disorders are, among others, explained by individual differences in temperamental variables (Mineka and Zinbarg, 2006). One such individual difference variable is how people process a learning experience when the conditioning stimuli are no longer present. Repeatedly thinking about the conditioning experience, as in worry or rumination, might prolong the initial (fear) reactions and as such, might leave certain individuals more vulnerable to developing an anxiety disorder. However, in human conditioning research, relatively little attention has been devoted to the processing of a memory trace after its initial acquisition, despite its potential influences on subsequent performance. Post-acquisition processing can be induced by mental reiteration of a conditioned stimulus-unconditioned stimulus (CS-US)-contingency. Using a human conditioned suppression paradigm, we investigated the effect of repeated activations of a CS-US-contingency memory on the level of conditioned responding at a later test. Results of three experiments showed more sustained responding to a “rehearsed” CS+ as compared to a “non-rehearsed” CS+. Moreover, the second experiment showed no effect of rehearsal when only the CS was rehearsed instead of the CS-US-contingency. The third experiment demonstrated that mental CS-US-rehearsal has the same effect regardless of whether it was cued by the CS and a verbal reference to the US or by a neutral signal, making the rehearsal “purely mental.” In sum, it was demonstrated that post-acquisition activation of a CS-US-contingency memory can impact conditioned responding, underlining the importance of post-acquisition processes in conditioning. This might indicate that individuals who are more prone

  19. Repeated Activation of a CS-US-Contingency Memory Results in Sustained Conditioned Responding.

    PubMed

    Joos, Els; Vansteenwegen, Debora; Vervliet, Bram; Hermans, Dirk

    2013-01-01

    Individuals seem to differ in conditionability, i.e., the ease by which the contingent presentation of two stimuli will lead to a conditioned response. In contemporary learning theory, individual differences in the etiology and maintenance of anxiety disorders are, among others, explained by individual differences in temperamental variables (Mineka and Zinbarg, 2006). One such individual difference variable is how people process a learning experience when the conditioning stimuli are no longer present. Repeatedly thinking about the conditioning experience, as in worry or rumination, might prolong the initial (fear) reactions and as such, might leave certain individuals more vulnerable to developing an anxiety disorder. However, in human conditioning research, relatively little attention has been devoted to the processing of a memory trace after its initial acquisition, despite its potential influences on subsequent performance. Post-acquisition processing can be induced by mental reiteration of a conditioned stimulus-unconditioned stimulus (CS-US)-contingency. Using a human conditioned suppression paradigm, we investigated the effect of repeated activations of a CS-US-contingency memory on the level of conditioned responding at a later test. Results of three experiments showed more sustained responding to a "rehearsed" CS+ as compared to a "non-rehearsed" CS+. Moreover, the second experiment showed no effect of rehearsal when only the CS was rehearsed instead of the CS-US-contingency. The third experiment demonstrated that mental CS-US-rehearsal has the same effect regardless of whether it was cued by the CS and a verbal reference to the US or by a neutral signal, making the rehearsal "purely mental." In sum, it was demonstrated that post-acquisition activation of a CS-US-contingency memory can impact conditioned responding, underlining the importance of post-acquisition processes in conditioning. This might indicate that individuals who are more prone to mentally

  20. Performed surfactant-optimized aqueous alkaline flood

    SciTech Connect

    Thigpen, D.R.; Lawson, J.B.; Nelson, R.C.

    1991-11-26

    This paper describes improvement in a process for recovering oil from an acidic oil reservoir by injecting an aqueous alkaline solution comprising water, sodium chloride, and alkaline material for reacting with the reservoir oil forming a petroleum acid soap to form an in-situ surfactant system. The improvement comprises: selecting a preformed cosurfactant which is soluble in both the aqueous solution and the reservoir oil and has a solubility ratio which is grater than the solubility ratio of the petroleum acid soap where the solubility ratio is the ratio of solubility in the aqueous alkaline solution to the solubility in the reservoir oil; combining with the alkaline solution an amount of the preformed cosurfactant which will result in the in-situ surfacant system having a salinity about equal to a salinity which results in minimal interfacial tension between the oil in the reservoir and the in-situ surfactant system at reservoir temperature, wherein the amount of the preformed cosurfactant is about 0.3 percent by weight in the aqueous alkaline solution; and injecting the cosurfactant-aqueous alkaline solution mixture into the reservoir to displace oil toward a fluid production location.

  1. Prebiotic Synthesis of Glycine from Ethanolamine in Simulated Archean Alkaline Hydrothermal Vents.

    PubMed

    Zhang, Xianlong; Tian, Ge; Gao, Jing; Han, Mei; Su, Rui; Wang, Yanxiang; Feng, Shouhua

    2016-09-23

    Submarine hydrothermal vents are generally considered as the likely habitats for the origin and evolution of early life on Earth. In recent years, a novel hydrothermal system in Archean subseafloor has been proposed. In this model, highly alkaline and high temperature hydrothermal fluids were generated in basalt-hosted hydrothermal vents, where H2 and CO2 could be abundantly provided. These extreme conditions could have played an irreplaceable role in the early evolution of life. Nevertheless, sufficient information has not yet been obtained for the abiotic synthesis of amino acids, which are indispensable components of life, at high temperature and alkaline condition. This study aims to propose a new method for the synthesis of glycine in simulated Archean submarine alkaline vent systems. We investigated the formation of glycine from ethanolamine under conditions of high temperature (80-160 °C) and highly alkaline solutions (pH = 9.70). Experiments were performed in an anaerobic environment under mild pressure (0.1-8.0 MPa) at the same time. The results suggested that the formation of glycine from ethanolamine occurred rapidly and efficiently in the presence of metal powders, and was favored by high temperatures and high pressures. The experiment provides a new pathway for prebiotic glycine formation and points out the phenomenal influence of high-temperature alkaline hydrothermal vents in origin of life in the early ocean.

  2. Prebiotic Synthesis of Glycine from Ethanolamine in Simulated Archean Alkaline Hydrothermal Vents

    NASA Astrophysics Data System (ADS)

    Zhang, Xianlong; Tian, Ge; Gao, Jing; Han, Mei; Su, Rui; Wang, Yanxiang; Feng, Shouhua

    2016-09-01

    Submarine hydrothermal vents are generally considered as the likely habitats for the origin and evolution of early life on Earth. In recent years, a novel hydrothermal system in Archean subseafloor has been proposed. In this model, highly alkaline and high temperature hydrothermal fluids were generated in basalt-hosted hydrothermal vents, where H2 and CO2 could be abundantly provided. These extreme conditions could have played an irreplaceable role in the early evolution of life. Nevertheless, sufficient information has not yet been obtained for the abiotic synthesis of amino acids, which are indispensable components of life, at high temperature and alkaline condition. This study aims to propose a new method for the synthesis of glycine in simulated Archean submarine alkaline vent systems. We investigated the formation of glycine from ethanolamine under conditions of high temperature (80-160 °C) and highly alkaline solutions (pH = 9.70). Experiments were performed in an anaerobic environment under mild pressure (0.1-8.0 MPa) at the same time. The results suggested that the formation of glycine from ethanolamine occurred rapidly and efficiently in the presence of metal powders, and was favored by high temperatures and high pressures. The experiment provides a new pathway for prebiotic glycine formation and points out the phenomenal influence of high-temperature alkaline hydrothermal vents in origin of life in the early ocean.

  3. Alkalinization in the Isolated and Perfused Anterior Midgut of the Larval Mosquito, Aedes aegypti

    PubMed Central

    Onken, Horst; Moffett, Stacia B.; Moffett, David F.

    2008-01-01

    In the present study, isolated midguts of larval Aedes aegypti L. (Diptera: Culicidae) were mounted on perfusion pipettes and bathed in high buffer mosquito saline. With low buffer perfusion saline, containing m-cresol purple, transepithelial voltage was monitored and luminal alkalinization became visible through color changes of m-cresol purple after perfusion stop. Lumen negative voltage and alkalinization depended on metabolic energy and were stimulated in the presence of serotonin (0.2 µmol l-1). In some experiments a pH microelectrode in the lumen recorded pH values up to 10 within minutes after perfusion stop. The V-ATPase inhibitor concanamycin (50 µmol l-1) on the hemolymph side almost abolished Vte and inhibited luminal alkalinization. The carbonic anhydrase inhibitor, methazolamide (50 µmol l-1), on either the luminal or hemolymph-side, or the inhibitor of anion transport, DIDS (1 mmol l-1) on the luminal side, had no effect on Vte or alkalinization. Cl- substitution in the lumen or on both sides of the tissue affected Vte, but the color change of m-cresol purple was unchanged from control conditions. Hemolymph-side Na+ substitution or addition of the Na+/H+ exchange inhibitor, amiloride (200 µmol l-1), reduced Vte and luminal alkalinization. Luminal amiloride (200 µmol l-1) was without effects on Vte or alkalinization. High K+ (60 mmol l-1) in the lumen reduced Vte without affecting alkalinization. These results indicate that strong luminal alkalinization in isolated and perfused anterior midgut of larval A. aegypti depends on basolateral V-ATPase, but is apparently independent of carbonic anhydrase, apical Cl-/HCO3- exchange or apical K+/2H+ antiport. PMID:20307229

  4. Results of the International Validation of the in vivo rodent alkaline comet assay for the detection of genotoxic carcinogens: Individual data for 1,2-dibromoethane, p-anisidine, and o-anthranilic acid in the 2nd step of the 4th phase Validation Study under the JaCVAM initiative.

    PubMed

    Takasawa, Hironao; Takashima, Rie; Narumi, Kazunori; Kawasako, Kazufumi; Hattori, Akiko; Kawabata, Masayoshi; Hamada, Shuichi

    2015-07-01

    As part of the Japanese Center for the Validation of Alternative Methods (JaCVAM)-initiative International Validation Study of an in vivo rat alkaline comet assay, we examined 1,2-dibromoethane (DBE), p-anisidine (ASD), and o-anthranilic acid (ANT) to investigate the effectiveness of the comet assay in detecting genotoxic carcinogens. Each of the three test chemicals was administered to 5 male Sprague-Dawley rats per group by oral gavage at 48, 24, and 3h before specimen preparation. Single cells were collected from the liver and glandular stomach at 3h after the final dosing, and the specimens prepared from these two organs were subjected to electrophoresis under alkaline conditions (pH>13). The percentage of DNA intensity in the comet tail was then assessed using an image analysis system. A micronucleus (MN) assay was also conducted using these three test chemicals with the bone marrow (BM) cells collected from the same animals simultaneously used in the comet assay, i.e., combination study of the comet assay and BM MN assay. A genotoxic (Ames positive) rodent carcinogen, DBE gave a positive result in the comet assay in the present study, while a genotoxic (Ames positive) non-carcinogen, ASD and a non-genotoxic (Ames negative) non-carcinogen, ANT showed negative results in the comet assay. All three chemicals produced negative results in the BM MN assay. While the comet assay findings in the present study were consistent with those obtained from the rodent carcinogenicity studies for the three test chemicals, we consider the positive result in the comet assay for DBE to be particularly meaningful, given that this chemical produced a negative result in the BM MN assay. Therefore, the combination study of the comet assay and BM MN assay is a useful method to detect genotoxic carcinogens that are undetectable with the BM MN assay alone.

  5. Alkaline and ultrasound assisted alkaline pretreatment for intensification of delignification process from sustainable raw-material.

    PubMed

    Subhedar, Preeti B; Gogate, Parag R

    2014-01-01

    Alkaline and ultrasound-assisted alkaline pretreatment under mild operating conditions have been investigated for intensification of delignification. The effect of NaOH concentration, biomass loading, temperature, ultrasonic power and duty cycle on the delignification has been studied. Most favorable conditions for only alkaline pretreatment were alkali concentration of 1.75 N, solid loading of 0.8% (w/v), temperature of 353 K and pretreatment time of 6 h and under these conditions, 40.2% delignification was obtained. In case of ultrasound-assisted alkaline approach, most favorable conditions obtained were alkali concentration of 1N, paper loading of 0.5% (w/v), sonication power of 100 W, duty cycle of 80% and pretreatment time of 70 min and the delignification obtained in ultrasound-assisted alkaline approach under these conditions was 80%. The material samples were characterized by FTIR, SEM, XRD and TGA technique. The lignin was recovered from solution by precipitation method and was characterized by FTIR, GPC and TGA technique.

  6. Performance of alkaline battery cells used in emergency locator transmitters

    NASA Technical Reports Server (NTRS)

    Haynes, G. A.; Sokol, S.; Motley, W. R., III; Mcclelland, E. L.

    1984-01-01

    The characteristics of battery power supplies for emergency locator transmitters (ELT's) were investigated by testing alkaline zinc/manganese dioxide cells of the type typically used in ELT's. Cells from four manufacturers were tested. The cells were subjected to simulated environmental and load conditions representative of those required for survival and operation. Battery cell characteristics that may contribute to ELT malfunctions and limitations were evaluated. Experimental results from the battery cell study are discussed, and an evaluation of ELT performance while operating under a representative worst-case environmental condition is presented.

  7. An assessment of consistence of exhaust gas emission test results obtained under controlled NEDC conditions

    NASA Astrophysics Data System (ADS)

    Balawender, K.; Jaworski, A.; Kuszewski, H.; Lejda, K.; Ustrzycki, A.

    2016-09-01

    Measurements concerning emissions of pollutants contained in automobile combustion engine exhaust gases is of primary importance in view of their harmful impact on the natural environment. This paper presents results of tests aimed at determining exhaust gas pollutant emissions from a passenger car engine obtained under repeatable conditions on a chassis dynamometer. The test set-up was installed in a controlled climate chamber allowing to maintain the temperature conditions within the range from -20°C to +30°C. The analysis covered emissions of such components as CO, CO2, NOx, CH4, THC, and NMHC. The purpose of the study was to assess repeatability of results obtained in a number of tests performed as per NEDC test plan. The study is an introductory stage of a wider research project concerning the effect of climate conditions and fuel type on emission of pollutants contained in exhaust gases generated by automotive vehicles.

  8. Kinetic studies of the [NpO₂ (CO₃)₃]⁴⁻ ion at alkaline conditions using ¹³C NMR

    SciTech Connect

    Panasci, Adele F.; Harley, Stephen J.; Zavarin, Mavrik; Casey, William H.

    2014-04-21

    Carbonate ligand-exchange rates on the [NpO₂ (CO₃)₃]⁴⁻ ion were determined using a saturation-transfer ¹³C nuclear magnetic resonance (NMR) pulse sequence in the pH range of 8.1 ≤ pH ≤ 10.5. Over the pH range 9.3 ≤ pH ≤ 10.5, which compares most directly with previous work of Stout et al.,1 we find an average rate, activation energy, enthalpy, and entropy of k298ex = 40.6(±4.3) s⁻¹, Ea =45.1(±3.8) kJ mol⁻¹, ΔH = 42.6(±3.8) kJ mol⁻¹, and ΔS = -72(±13) J mol⁻¹ K⁻¹, respectively. These activation parameters are similar to the Stout et al. results at pH 9.4. However, their room-temperature rate at pH 9.4, k298ex = 143(±1.0) s⁻¹, is ~3 times faster than what we experimentally determined at pH 9.3: k298ex = 45.4(±5.3) s⁻¹. Our rates for [NpO₂ (CO₃)₃]⁴⁻ are also faster by a factor of ~3 relative to the isoelectronic [UO₂(CO₃)₃]⁴⁻ as reported by Brucher et al.2 of k298ex = 13(±3) s⁻¹. Consistent with results for the [UO₂(CO₃)₃]⁴⁻ ion, we find evidence for a proton-enhanced pathway for carbonate exchange for the [NpO₂(CO₃)₃]⁴⁻ ion at pH < 9.0.

  9. Effect of solids retention time and temperature on waste activated sludge hydrolysis and short-chain fatty acids accumulation under alkaline conditions in continuous-flow reactors.

    PubMed

    Feng, Leiyu; Wang, Hua; Chen, Yinguang; Wang, Qin

    2009-01-01

    The effects of solids retention time (SRT) and temperature on waste activated sludge (WAS) hydrolysis and short-chain fatty acids (SCFAs) accumulation were investigated in a series of continuous-flow reactors at pH 10. The experimental results showed that the increase of either SRT or temperature benefited the hydrolysis of WAS and the production of SCFAs. The changes in SRT gave also impact on the percentage of acetic and propionic acids in the fermentative SCFAs, but little influence on that of the slightly long-chain SCFAs, such as n-butyric, iso-butyric, n-valeric and iso-valeric acids. Compared with the control (pH unadjusted) experiment, at SRT of 12d and temperature of 20 degrees C the concentration of SCFAs produced at pH 10 increased from 261.2 to 933.5mg COD/L, and the propionic acid percentage improved from 11.7 to 16.0%. It can be concluded from this investigation that the efficient continuous production of SCFAs at pH 10 is feasible.

  10. Systemic and local effects of long-term exposure to alkaline drinking water in rats.

    PubMed

    Merne, M E; Syrjänen, K J; Syrjänen, S M

    2001-08-01

    Alkaline conditions in the oral cavity may be caused by a variety of stimuli, including tobacco products, antacids, alkaline drinking water or bicarbonate toothpaste. The effects of alkaline pH on oral mucosa have not been systematically studied. To assess the systemic (organ) and local (oral mucosal) effects of alkalinity, drinking water supplemented with Ca(OH)2 or NaOH, with pH 11.2 or 12 was administered to rats (n = 36) for 52 weeks. Tissues were subjected to histopathological examination; oral mucosal biopsy samples were also subjected to immunohistochemical (IHC) analyses for pankeratin, CK19, CK5, CK4, PCNA, ICAM-1, CD44, CD68, S-100, HSP 60, HSP70, and HSP90. At completion of the study, animals in the study groups had lower body weights (up to 29% less) than controls despite equal food and water intake, suggesting a systemic response to the alkaline treatment. The lowest body weight was found in rats exposed to water with the highest pH value and starting the experiment when young (6 weeks). No histological changes attributable to alkaline exposure occurred in the oral mucosa or other tissues studied. Alkaline exposure did not affect cell proliferation in the oral epithelium, as shown by the equal expression of PCNA in groups. The up-regulation of HSP70 protein expression in the oral mucosa of rats exposed to alkaline water, especially Ca(OH)2 treated rats, may indicate a protective response. Intercellular adhesion molecule-1 (ICAM-1) positivity was lost in 6/12 rats treated with Ca(OH)2 with pH 11.2, and loss of CD44 expression was seen in 3/6 rats in both study groups exposed to alkaline water with pH 12. The results suggest that the oral mucosa in rats is resistant to the effects of highly alkaline drinking water. However, high alkalinity may have some unknown systemic effects leading to growth retardation, the cause of which remains to be determined.

  11. Systemic and local effects of long-term exposure to alkaline drinking water in rats

    PubMed Central

    Merne, Marina ET; Syrjänen, Kari J; Syrjänen, Stina M

    2001-01-01

    Alkaline conditions in the oral cavity may be caused by a variety of stimuli, including tobacco products, antacids, alkaline drinking water or bicarbonate toothpaste. The effects of alkaline pH on oral mucosa have not been systematically studied. To assess the systemic (organ) and local (oral mucosal) effects of alkalinity, drinking water supplemented with Ca(OH)2 or NaOH, with pH 11.2 or 12 was administered to rats (n = 36) for 52 weeks. Tissues were subjected to histopathological examination; oral mucosal biopsy samples were also subjected to immunohistochemical (IHC) analyses for pankeratin, CK19, CK5, CK4, PCNA, ICAM-1, CD44, CD68, S-100, HSP 60, HSP70, and HSP90. At completion of the study, animals in the study groups had lower body weights (up to 29% less) than controls despite equal food and water intake, suggesting a systemic response to the alkaline treatment. The lowest body weight was found in rats exposed to water with the highest pH value and starting the experiment when young (6 weeks). No histological changes attributable to alkaline exposure occurred in the oral mucosa or other tissues studied. Alkaline exposure did not affect cell proliferation in the oral epithelium, as shown by the equal expression of PCNA in groups. The up-regulation of HSP70 protein expression in the oral mucosa of rats exposed to alkaline water, especially Ca(OH)2 treated rats, may indicate a protective response. Intercellular adhesion molecule-1 (ICAM-1) positivity was lost in 6/12 rats treated with Ca(OH)2 with pH 11.2, and loss of CD44 expression was seen in 3/6 rats in both study groups exposed to alkaline water with pH 12. The results suggest that the oral mucosa in rats is resistant to the effects of highly alkaline drinking water. However, high alkalinity may have some unknown systemic effects leading to growth retardation, the cause of which remains to be determined. PMID:11493345

  12. 24 CFR 902.68 - Technical review of results of PHAS physical condition indicator.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 4 2013-04-01 2013-04-01 false Technical review of results of PHAS physical condition indicator. 902.68 Section 902.68 Housing and Urban Development REGULATIONS RELATING TO HOUSING AND URBAN DEVELOPMENT (CONTINUED) OFFICE OF ASSISTANT SECRETARY FOR PUBLIC AND INDIAN...

  13. Working Conditions of Foreign Language Teachers: Results from a Pilot Survey

    ERIC Educational Resources Information Center

    Lopez-Gomez, Coral; Albright, Jeremy J.

    2009-01-01

    Recent research has consistently shown that teacher working conditions are highly predictive of faculty turnover and student performance. However, very little work investigates specifically the experiences of foreign-language instructors. This paper reports results from a pilot survey of language teachers in public and private schools from across…

  14. INVITED SESSION: THE 2011 NATIONAL WETLAND CONDITION ASSESSMENT: TECHNICAL UNDERPINNINGS AND RESULTS

    EPA Science Inventory

    The first-ever National Wetland Condition Assessment (NWCA) was conducted in 2011 by the US Environmental Protection Agency (USEPA) and its federal and state partners, using a survey design allowing extrapolation of results to national and regional scales. At each of 1138 locatio...

  15. Hippocampal Structural Plasticity Accompanies the Resulting Contextual Fear Memory Following Stress and Fear Conditioning

    ERIC Educational Resources Information Center

    Giachero, Marcelo; Calfa, Gaston D.; Molina, Victor A.

    2013-01-01

    The present research investigated the resulting contextual fear memory and structural plasticity changes in the dorsal hippocampus (DH) following stress and fear conditioning. This combination enhanced fear retention and increased the number of total and mature dendritic spines in DH. Intra-basolateral amygdala (BLA) infusion of midazolam prior to…

  16. Results of the Housing Building Condition Evaluation Survey at the University of Georgia.

    ERIC Educational Resources Information Center

    Casey, John M.

    A complete campus building condition evaluation survey was conducted at the University of Georgia in 1989 and results for the housing department were analyzed. The survey design was based on a model developed by Harlan Bareither at the University of Illinois that separates building deficiencies into seven general headings. Data were collected at…

  17. 49 CFR 236.528 - Restrictive condition resulting from open hand-operated switch; requirement.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...-operated switch; requirement. 236.528 Section 236.528 Transportation Other Regulations Relating to... Instructions; Roadway § 236.528 Restrictive condition resulting from open hand-operated switch; requirement. When a facing point hand-operated switch is open one-fourth inch or more, a trailing point...

  18. 49 CFR 236.528 - Restrictive condition resulting from open hand-operated switch; requirement.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...-operated switch; requirement. 236.528 Section 236.528 Transportation Other Regulations Relating to... Instructions; Roadway § 236.528 Restrictive condition resulting from open hand-operated switch; requirement. When a facing point hand-operated switch is open one-fourth inch or more, a trailing point...

  19. 38 CFR 21.9675 - Conditions that result in reduced rates or no payment.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2013-07-01 2013-07-01 false Conditions that result in reduced rates or no payment. 21.9675 Section 21.9675 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED) VOCATIONAL REHABILITATION AND EDUCATION Post-9/11 GI Bill...

  20. 38 CFR 21.9675 - Conditions that result in reduced rates or no payment.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2014-07-01 2014-07-01 false Conditions that result in reduced rates or no payment. 21.9675 Section 21.9675 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED) VOCATIONAL REHABILITATION AND EDUCATION Post-9/11 GI Bill...

  1. 38 CFR 21.9675 - Conditions that result in reduced rates or no payment.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2011-07-01 2011-07-01 false Conditions that result in reduced rates or no payment. 21.9675 Section 21.9675 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED) VOCATIONAL REHABILITATION AND EDUCATION Post-9/11 GI Bill...

  2. 38 CFR 21.9675 - Conditions that result in reduced rates or no payment.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2012-07-01 2012-07-01 false Conditions that result in reduced rates or no payment. 21.9675 Section 21.9675 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED) VOCATIONAL REHABILITATION AND EDUCATION Post-9/11 GI Bill...

  3. Laser direct write of planar alkaline microbatteries

    NASA Astrophysics Data System (ADS)

    Arnold, C. B.; Kim, H.; Piqué, A.

    We are developing a laser engineering approach to fabricate and optimize alkaline microbatteries in planar geometries. The laser direct-write technique enables multicapability for adding, removing and processing material and provides the ability to pattern complicated structures needed for fabricating complete microbattery assemblies. In this paper, we demonstrate the production of planar zinc-silver oxide alkaline cells under ambient conditions. The microbattery cells exhibit 1.55-V open-circuit potentials, as expected for the battery chemistry, and show a flat discharge behavior under constant-current loads. High capacities of over 450 μAhcm-2 are obtained for 5-mm2 microbatteries.

  4. Ocean Acidification: Coccolithophore's Light Controlled Effect on Alkalinity

    NASA Astrophysics Data System (ADS)

    Dobbins, W.

    2015-12-01

    Coccolithophorids, which play a significant role in the flux of calcite and organic carbon from the photic region to deeper pelagic and benthic zones, are potentially far more useful than siliceous phytoplankton for ocean fertilization projects designed to sequester CO2. However, the production of H+ ions during calcification (HCO3 + Ca+ —> CaCO3 + H+) has resulted in localized acidification around coccolithophore blooms. It has been hypothesized that under the correct light conditions photosynthesis could proceed at a rate such that CO2 is removed in amounts equimolar or greater than the H+ produced by calcification, allowing stable or increasing alkalinity despite ongoing calcification. Previously, this effect had not been demonstrated under laboratory conditions. Fifteen Emiliania huxleyi cultures were separated into equal groups with each receiving: 0, 6, 12, 18, or 24 hours of light each day for 24 days. Daily pH, cell density, and temperature measurements revealed a strong positive correlation between light exposure and pH, and no significant decline in pH in any of the cultures. Alkalinity increases were temperature independent and not strongly correlated with cell density, implying photosynthetic removal of carbon dioxide as the root cause. The average pH across living cultures increased from 7.9 to 8.3 over the first week and changed little for the reminder of the 24-day period. The results demonstrate coccolithophorids can increase alkalinity across a broad range of cell densities, despite the acidification inherent to the calcification process. If the light-alkalinity effect reported here proves scalable to larger cultures, Emiliania huxleyi are a strong candidate for carbon sequestration via targeted ocean fertilization.

  5. Treatment of Alkaline Cr(VI)-Contaminated Leachate with an Alkaliphilic Metal-Reducing Bacterium

    PubMed Central

    Watts, Mathew P.; Khijniak, Tatiana V.; Boothman, Christopher

    2015-01-01

    Chromium in its toxic Cr(VI) valence state is a common contaminant particularly associated with alkaline environments. A well-publicized case of this occurred in Glasgow, United Kingdom, where poorly controlled disposal of a cementitious industrial by-product, chromite ore processing residue (COPR), has resulted in extensive contamination by Cr(VI)-contaminated alkaline leachates. In the search for viable bioremediation treatments for Cr(VI), a variety of bacteria that are capable of reduction of the toxic and highly soluble Cr(VI) to the relatively nontoxic and less mobile Cr(III) oxidation state, predominantly under circumneutral pH conditions, have been isolated. Recently, however, alkaliphilic bacteria that have the potential to reduce Cr(VI) under alkaline conditions have been identified. This study focuses on the application of a metal-reducing bacterium to the remediation of alkaline Cr(VI)-contaminated leachates from COPR. This bacterium, belonging to the Halomonas genus, was found to exhibit growth concomitant to Cr(VI) reduction under alkaline conditions (pH 10). Bacterial cells were able to rapidly remove high concentrations of aqueous Cr(VI) (2.5 mM) under anaerobic conditions, up to a starting pH of 11. Cr(VI) reduction rates were controlled by pH, with slower removal observed at pH 11, compared to pH 10, while no removal was observed at pH 12. The reduction of aqueous Cr(VI) resulted in the precipitation of Cr(III) biominerals, which were characterized using transmission electron microscopy and energy-dispersive X-ray analysis (TEM-EDX) and X-ray photoelectron spectroscopy (XPS). The effectiveness of this haloalkaliphilic bacterium for Cr(VI) reduction at high pH suggests potential for its use as an in situ treatment of COPR and other alkaline Cr(VI)-contaminated environments. PMID:26048926

  6. Treatment of Alkaline Cr(VI)-Contaminated Leachate with an Alkaliphilic Metal-Reducing Bacterium.

    PubMed

    Watts, Mathew P; Khijniak, Tatiana V; Boothman, Christopher; Lloyd, Jonathan R

    2015-08-15

    Chromium in its toxic Cr(VI) valence state is a common contaminant particularly associated with alkaline environments. A well-publicized case of this occurred in Glasgow, United Kingdom, where poorly controlled disposal of a cementitious industrial by-product, chromite ore processing residue (COPR), has resulted in extensive contamination by Cr(VI)-contaminated alkaline leachates. In the search for viable bioremediation treatments for Cr(VI), a variety of bacteria that are capable of reduction of the toxic and highly soluble Cr(VI) to the relatively nontoxic and less mobile Cr(III) oxidation state, predominantly under circumneutral pH conditions, have been isolated. Recently, however, alkaliphilic bacteria that have the potential to reduce Cr(VI) under alkaline conditions have been identified. This study focuses on the application of a metal-reducing bacterium to the remediation of alkaline Cr(VI)-contaminated leachates from COPR. This bacterium, belonging to the Halomonas genus, was found to exhibit growth concomitant to Cr(VI) reduction under alkaline conditions (pH 10). Bacterial cells were able to rapidly remove high concentrations of aqueous Cr(VI) (2.5 mM) under anaerobic conditions, up to a starting pH of 11. Cr(VI) reduction rates were controlled by pH, with slower removal observed at pH 11, compared to pH 10, while no removal was observed at pH 12. The reduction of aqueous Cr(VI) resulted in the precipitation of Cr(III) biominerals, which were characterized using transmission electron microscopy and energy-dispersive X-ray analysis (TEM-EDX) and X-ray photoelectron spectroscopy (XPS). The effectiveness of this haloalkaliphilic bacterium for Cr(VI) reduction at high pH suggests potential for its use as an in situ treatment of COPR and other alkaline Cr(VI)-contaminated environments.

  7. Biochemical Localization of Alkaline Phosphatase in the Cell Wall of a Marine Pseudomonad

    PubMed Central

    Thompson, Linda M. M.; MacLeod, Robert A

    1974-01-01

    The various layers of the cell envelope of marine pseudomonad B-16 (ATCC 19855) have been separated from the cells and assayed directly for alkaline phosphatase activity under conditions established previously to be optimum for maintenance of the activity of the enzyme. Under conditions known to lead to the release of the contents of the periplasmic space from the cells, over 90% of the alkaline phosphatase was released into the medium. Neither the loosely bound outer layer nor the outer double-track layer (cell wall membrane) showed significant activity. A small amount of the alkaline phosphatase activity of the cells remained associated with the mureinoplasts when the outer layers of the cell wall were removed. Upon treatment of the mureinoplasts with lysozyme, some alkaline phosphatase was released into the medium and some remained with the protoplasts formed. Cells washed and suspended in 0.5 M NaCl were lysed by treatment with 2% toluene, and 95% of the alkaline phosphatase in the cells was released into the medium. Cells washed and suspended in complete salts solution (0.3 M NaCl, 0.05 M MgSO4, and 0.01 M KCl) or 0.05 M MgSO4 appeared intact after treatment with toluene but lost 50 and 10%, respectively, of their alkaline phosphatase. The results suggest that the presence of Mg2+ in the cell wall is necessary to prevent disruption of the cells by toluene and may also be required to prevent the release of alkaline phosphatase by toluene when disruption of the cells by toluene does not take place. PMID:4811547

  8. Effects of boundary conditions and partial drainage on cyclic simple shear test results - a numerical study

    NASA Astrophysics Data System (ADS)

    Wang, Bin; Popescu, Radu; Prevost, Jean H.

    2004-08-01

    Owing to imperfect boundary conditions in laboratory soil tests and the possibility of water diffusion inside the soil specimen in undrained tests, the assumption of uniform stress/strain over the sample is not valid. This study presents a qualitative assessment of the effects of non-uniformities in stresses and strains, as well as effects of water diffusion within the soil sample on the global results of undrained cyclic simple shear tests. The possible implications of those phenomena on the results of liquefaction strength assessment are also discussed. A state-of-the-art finite element code for transient analysis of multi-phase systems is used to compare results of the so-called element tests (numerical constitutive experiments assuming uniform stress/strain/pore pressure distribution throughout the sample) with results of actual simulations of undrained cyclic simple shear tests using a finite element mesh and realistic boundary conditions. The finite element simulations are performed under various conditions, covering the entire range of practical situations: (1) perfectly drained soil specimen with constant volume, (2) perfectly undrained specimen, and (3) undrained test with possibility of water diffusion within the sample. The results presented here are restricted to strain-driven tests performed for a loose uniform fine sand with relative density Dr=40%. Effects of system compliance in undrained laboratory simple shear tests are not investigated here. Copyright

  9. Results on the survival of cryptobiotic cyanobacteria samples after exposure to Mars-like environmental conditions

    NASA Astrophysics Data System (ADS)

    de Vera, J.-P.; Dulai, S.; Kereszturi, A.; Koncz, L.; Lorek, A.; Mohlmann, D.; Marschall, M.; Pocs, T.

    2014-01-01

    Tests on cyanobacteria communities embedded in cryptobiotic crusts collected in hot and cold deserts on Earth were performed under Mars-like conditions. The simulations were realized as a survey, to find the best samples for future research. During the tests organisms have to resist Mars-like conditions such as atmospheric composition, pressure, variable humidity (saturated and dry conditions) and partly strong UV irradiation. Organisms were tested within their original habitat inside the crust. Nearly half of the cryptobiotic samples from various sites showed survival of a substantial part of their coexisting organisms. The survival in general depended more on the nature of the original habitat and type of the sample than on the different conditions they were exposed to. The best survival was observed in samples from United Arab Emirates (Jebel Ali, 25 km SW of Dubai town) and from Western Australia (near the South edge of Lake Barley), by taxa: Tolypothrix byssoidea, Gloeocapsopsis pleurocapsoides, Nostoc microscopicum, Leptolyngbya or Symploca sp. At both places in salty desert areas members of the Chenopodiaceae family dominated among the higher plants and in the cryptobiotic crust cyanobacterial taxa Tolypothrix was dominant. These organisms were all living in salty locations with dry conditions most of the year. Among them Tolypothrix, Gloeocapsopsis and Symploca sp. were tested in Mars simulation chambers for the first time. The results suggest that extremophiles should be tested with taken into account the context of their original microenvironment, and also the importance to analyse communities of microbes beside single organisms.

  10. Facile electrochemical co-deposition of a graphene-cobalt nanocomposite for highly efficient water oxidation in alkaline media: direct detection of underlying electron transfer reactions under catalytic turnover conditions.

    PubMed

    Guo, Si-Xuan; Liu, Yuping; Bond, Alan M; Zhang, Jie; Esakki Karthik, P; Maheshwaran, I; Senthil Kumar, S; Phani, K L N

    2014-09-21

    A facile electrochemical co-deposition method has been developed for the fabrication of graphene-cobalt nanocomposite modified electrodes that achieve exceptionally efficient water oxidation in highly alkaline media. In the method reported, a graphene-cobalt nanocomposite film was deposited electrochemically from a medium containing 1 mg ml(-1) graphene oxide, 0.8 mM cobalt nitrate and 0.05 M phytic acid (pH 7). The formation of the nanocomposite film was confirmed using electrochemical, Raman spectroscopic and scanning electron microscopic techniques. The nanocomposite film exhibits excellent activity and stability towards water oxidation to generate oxygen in 1 M NaOH aqueous electrolyte media. A turn over frequency of 34 s(-1) at an overpotential of 0.59 V and a faradaic efficiency of 97.7% were deduced from analysis of data obtained by rotating ring disk electrode voltammetry. Controlled potential electrolysis data suggests that the graphene supported catalyst exhibits excellent stability under these harsh conditions. Phytate anion acts as stabilizer for the electrochemical formation of cobalt nanoparticles. Fourier transformed ac voltammetry allowed the redox chemistry associated with catalysis to be detected directly under catalytic turnover conditions. Estimates of formal reversible potentials obtained from this method and derived from the overall reactions 3Co(OH)2 + 2OH(-) ⇌ Co3O4 + 4H2O + 2e(-), Co3O4 + OH(-) ⇌ 3CoOOH + e(-) and CoOOH + OH(-) ⇌ CoO2 + H2O + e(-) are 0.10, 0.44 and 0.59 V vs. Ag/AgCl, respectively.

  11. Effect of exogenous spermidine on polyamine content and metabolism in tomato exposed to salinity-alkalinity mixed stress.

    PubMed

    Hu, Xiaohui; Zhang, Yi; Shi, Yu; Zhang, Zhi; Zou, Zhirong; Zhang, Hao; Zhao, Jiuzhou

    2012-08-01

    We investigated the effects of seeds pretreatment with exogenous spermidine (Spd) on the polyamine content and metabolism in the roots of two cultivars of tomato (Solanum lycopersicum), Jinpengchaoguan and Zhongza No. 9 grown under conditions of mixed salinity-alkalinity stress. These cultivars differ in their tolerance to salinity stress, with the former more tolerant than the latter. PA content, whether in its free forms, soluble conjugated forms, or insoluble bound forms, increased significantly during salinity-alkalinity stress. The activities of S-adenosylmethionine decarboxylase (SAMDC) and diamine oxidase (DAO), concentrations of free Spd, soluble conjugated forms of Spd and spermine (Spm), and insoluble bound form of Spd in the roots were enhanced to a greater extent in cv. Jinpengchaoguan roots than in cv. Zhongza No.9 in response to salinity-alkalinity stress. Interestingly, Spd application to seeds markedly suppressed the accumulation of free Put, but promoted an increase in free Spd and Spm concentrations, as well as soluble conjugated forms of Spd and insoluble bound forms of Put in both cultivars. From these data, we deduced that exogenous Spd promotes the conversion of free Put into free Spd and Spm, and soluble conjugated forms and insoluble bound forms of PAs under salinity-alkalinity stress. Furthermore, under salinity-alkalinity stress conditions, exogenous Spd enhanced the activities of ODC, SAMDC and DAO, and reduced the activities of ADC and polyamine oxidase (PAO) in cv. Zhongza No.9 roots. In addition, exogenous Spd reduced the activities of ADC and ODC, and increased the activities of DAO and SAMDC in cv. Jinpengchaoguan roots under salinity-alkalinity stress conditions. These results suggest that exogenous Spd treatment can regulate the metabolic status of polyamines caused by salinity-alkalinity stress, and eventually enhance tolerance of tomato plants to salinity-alkalinity stress. Additionally, Spd treatments have varying effects on

  12. Vapor-liquid partitioning of alkaline earth and transition metals in NaCl-dominated hydrothermal fluids: An experimental study from 360 to 465 °C, near-critical to halite saturated conditions

    NASA Astrophysics Data System (ADS)

    Pester, Nicholas J.; Ding, Kang; Seyfried, William E.

    2015-11-01

    Multi-phase fluid flow is a common occurrence in magmatic hydrothermal systems; and extensive modeling efforts using currently established P-V-T-x properties of the NaCl-H2O system are impending. We have therefore performed hydrothermal flow experiments (360-465 °C) to observe vapor-liquid partitioning of alkaline earth and first row transition metals in NaCl-dominated source solutions. The data allow extraction of partition coefficients related to the intrinsic changes in both chlorinity and density along the two-phase solvus. The coefficients yield an overall decrease in vapor affinity in the order Cu(I) > Na > Fe(II) > Zn > Ni(II) ⩾ Mg ⩾ Mn(II) > Co(II) > Ca > Sr > Ba, distinguished with 95% confidence for vapor densities greater than ∼0.2 g/cm3. The alkaline earth metals are limited to purely electrostatic interactions with Cl ligands, resulting in an excellent linear correlation (R2 > 0.99) between their partition coefficients and respective ionic radii. Though broadly consistent with this relationship, relative behavior of the transition metals is not well resolved, being likely obscured by complex bonding processes and the potential participation of Na in the formation of tetra-chloro species. At lower densities (at/near halite saturation) partitioning behavior of all metals becomes highly non-linear, where M/Cl ratios in the vapor begin to increase despite continued decreases in chlorinity and density. We refer to this phenomenon as "volatility", which is broadly associated with substantial increases in the HCl/NaCl ratio (eventually to >1) due to hydrolysis of NaCl. Some transition metals (e.g., Fe, Zn) exhibit volatility prior to halite stability, suggesting a potential shift in vapor speciation relative to nearer critical regions of the vapor-liquid solvus. The chemistry of deep-sea hydrothermal fluids appears affected by this process during magmatic events, however, our results do not support suggestions of subseafloor halite precipitation

  13. Effects of Solar Wind Conditions on the Plasma Wake Within a Polar Crater: Preliminary Results

    NASA Technical Reports Server (NTRS)

    Zimmerman, M. I.; Farrell, W. M.; Stubbs, T. J.

    2011-01-01

    As the solar wind sweeps horizontally past a shadowed lunar crater it simultaneously diffuses toward the surface through an ambipolar process, forming a plasma wake (e.g., Figure 1). Importantly, the resulting electric field structure diverts solar wind protons toward the cold crater floor where they may represent a source of surficial hydrogen. We present a handful of two-dimensional kinetic simulations exploring the range of wake structures and surface particle fluxes possible under various background plasma conditions.

  14. An alkaline active xylanase: insights into mechanisms of high pH catalytic adaptation.

    PubMed

    Mamo, Gashaw; Thunnissen, Marjolein; Hatti-Kaul, Rajni; Mattiasson, Bo

    2009-09-01

    The alkaliphilic bacterium, Bacillus halodurans S7, produces an alkaline active xylanase (EC 3.2.1.8), which differs from many other xylanases in being operationally stable under alkaline conditions as well as at elevated temperature. Compared to non-alkaline active xylanases, this enzyme has a high percent composition of acidic amino acids which results in high ratio of negatively to positively charged residues. A positive correlation was observed between the charge ratio and the pH optima of xylanases. The recombinant xylanase was crystallized using a hanging drop diffusion method. The crystals belong to the space group P2(1)2(1)2(1) and the structure was determined at a resolution of 2.1 A. The enzyme has the common eight-fold TIM-barrel structure of family 10 xylanases; however, unlike non-alkaline active xylanases, it has a highly negatively charged surface and a deeper active site cleft. Mutational analysis of non-conserved amino acids which are close to the acid/base residue has shown that Val169, Ile170 and Asp171 are important to hydrolyze xylan at high pH. Unlike the wild type xylanase which has optimum pH at 9-9.5, the triple mutant xylanase (V169A, I170F and D171N), which was constructed using sequence information of alkaline sensitive xylanses was optimally active around pH 7. Compared to non-alkaline active xylanases, the alkaline active xylanases have highly acidic surfaces and fewer solvent exposed alkali labile residues. Based on these results obtained from sequence, structural and mutational analysis, the possible mechanisms of high pH stability and catalysis are discussed. This will provide useful information to understand the mechanism of high pH adaptation and engineering of enzymes that can be operationally stable at high pH.

  15. IMAGE Project: Results of Laboratory Tests on Tracers for Supercritical Conditions.

    NASA Astrophysics Data System (ADS)

    Brandvoll, Øyvind; Opsahl Viig, Sissel; Nardini, Isabella; Muller, Jiri

    2016-04-01

    The use of tracers is a well-established technique for monitoring dynamic behaviour of water and gas through a reservoir. In geothermal reservoirs special challenges are encountered due to high temperatures and pressures. In this work, tracer candidates for monitoring water at supercritical conditions (temperature > 374°C, pressure ca 218 bar), are tested in laboratory experiments. Testing of tracers at supercritical water conditions requires experimental set-ups which tolerate harsh conditions with respect to high temperature and pressure. In addition stringent HES (health, environment and safety) factors have to be taken into consideration when designing and performing the experiments. The setup constructed in this project consists of a pressure vessel, high pressure pump, instrumentation for pressure and temperature control and instrumentation required for accurate sampling of tracers. In order to achieve accurate results, a special focus has been paid to the development of the tracer sampling technique. Perfluorinated cyclic hydrocarbons (PFCs) have been selected as tracer candidates. This group of compounds is today commonly used as gas tracers in oil reservoirs. According to the literature they are stable at temperatures up to 400°C. To start with, five PFCs have been tested for thermal stability in static experiments at 375°C and 108 bar in the experimental setup described above. The tracer candidates will be further tested for several months at the relevant conditions. Preliminary results indicate that some of the PFC compounds show stability after three months. However, in order to arrive at conclusive results, the experiments have to be repeated over a longer period and paying special attention to more accurate sampling procedures.

  16. Experimental results from containment piping bellows subjected to severe accident conditions. Volume 1, Results from bellows tested in `like-new` conditions

    SciTech Connect

    Lambert, L.D.; Parks, M.B.

    1994-09-01

    Bellows are an integral part of the containment pressure boundary in nuclear power plants. They are used at piping penetrations to allow relative movement between piping and the containment wall, while minimizing the load imposed on the piping and wall. Piping bellows are primarily used in steel containments; however, they have received limited use in some concrete (reinforced and prestressed) containments. In a severe accident they may be subjected to pressure and temperature conditions that exceed the design values, along with a combination of axial and lateral deflections. A test program to determine the leak-tight capacity of containment penetration bellows is being conducted under the sponsorship of the US Nuclear Regulatory Commission at Sandia National Laboratories. Several different bellows geometries, representative of actual containment bellows, have been subjected to extreme deflections along with pressure and temperature loads. The bellows geometries and loading conditions are described along with the testing apparatus and procedures. A total of thirteen bellows have been tested, all in the `like-new` condition. (Additional tests are planned of bellows that have been subjected to corrosion.) The tests showed that bellows are capable of withstanding relatively large deformations, up to, or near, the point of full compression or elongation, before developing leakage. The test data is presented and discussed.

  17. Catalytic Diversity in Alkaline Hydrothermal Vent Systems on Ocean Worlds

    NASA Astrophysics Data System (ADS)

    Cameron, Ryan D.; Barge, Laura; Chin, Keith B.; Doloboff, Ivria J.; Flores, Erika; Hammer, Arden C.; Sobron, Pablo; Russell, Michael J.; Kanik, Isik

    2016-10-01

    Hydrothermal systems formed by serpentinization can create moderate-temperature, alkaline systems and it is possible that this type of vent could exist on icy worlds such as Europa which have water-rock interfaces. It has been proposed that some prebiotic chemistry responsible for the emergence of life on Earth and possibly other wet and icy worlds could occur as a result ofredox potential and pH gradients in submarine alkaline hydrothermal vents (Russell et al., 2014). Hydrothermal chimneys formed in laboratory simulations of alkaline vents under early Earth conditions have precipitate membranes that contain minerals such as iron sulfides, which are hypothesized to catalyze reduction of CO2 (Yamaguchi et al. 2014, Roldan et al. 2014) leading to further organic synthesis. This CO2 reduction process may be affected by other trace components in the chimney, e.g. nickel or organic molecules. We have conducted experiments to investigate catalytic properties of iron and iron-nickel sulfides containing organic dopants in slightly acidic ocean simulants relevant to early Earth or possibly ocean worlds. We find that the electrochemical properties of the chimney as well as the morphology/chemistry of the precipitate are affected by the concentration and type of organics present. These results imply that synthesis of organics in water-rock systems on ocean worlds may lead to hydrothermal precipitates which can incorporate these organic into the mineral matrix and may affect the role of gradients in alkaline vent systems.Therefore, further understanding on the electroactive roles of various organic species within hydrothermal chimneys will have important implications for habitability as well as prebiotic chemistry. This work is funded by NASA Astrobiology Institute JPL Icy Worlds Team and a NAI Director's Discretionary Fund award.Yamaguchi A. et al. (2014) Electrochimica Acta, 141, 311-318.Russell, M. J. et al. (2014), Astrobiology, 14, 308-43.Roldan, A. (2014) Chem. Comm. 51

  18. Surfactant-enhanced alkaline flooding field project. Annual report, Revision

    SciTech Connect

    French, T.R.

    1991-10-01

    The Tucker sand of Helper (KS) field is a candidate for surfactant-enhanced alkaline flooding. The geology of the Helper site is typical of many DOE Class I reservoirs. The Tucker sand of Helper field was deposited in a fluvial dominated deltaic environment. Helper oil can be mobilized with either chemical system 2 or chemical system 3, as described in this report. Oil fields in the Gulf Coast region are also good candidates for surfactant-enhanced alkaline flooding. The results from laboratory tests conducted in Berea sandstone cores with oil brine from Helper (KS) field are encouraging. The crude oil is viscous and non-acidic and, yet, was mobilized by the chemical formulations described in this report. Significant amounts of the oil were mobilized under simulated reservoir conditions. The results in Berea sandstone cores were encouraging and should be verified by tests with field core. Consumption of alkali, measured with field core, was very low. Surfactant loss appeared to be acceptable. Despite the good potential for mobilization of Helper oil, certain reservoir characteristics such as low permeability, compartmentalization, and shallow depth place constraints on applications of any chemical system in the Tucker sand. These constraints are typical of many DOE Class I reservoirs. Although Hepler field is not a perfect reservoir in which to apply surfactant- enhanced alkaline flooding, Hepler oil is particularly amenable to mobilization by surfactant-enhanced alkaline systems. A field test is recommended, dependent upon final evaluation of well logs and cores from the proposed pilot area. 14 refs., 21 figs., 10 tabs.

  19. Whole Lichen Thalli Survive Exposure to Space Conditions: Results of Lithopanspermia Experiment with Aspicilia fruticulosa

    NASA Astrophysics Data System (ADS)

    Raggio, J.; Pintado, A.; Ascaso, C.; De La Torre, R.; De Los Ríos, A.; Wierzchos, J.; Horneck, G.; Sancho, L. G.

    2011-05-01

    The Lithopanspermia space experiment was launched in 2007 with the European Biopan facility for a 10-day spaceflight on board a Russian Foton retrievable satellite. Lithopanspermia included for the first time the vagrant lichen species Aspicilia fruticulosa from Guadalajara steppic highlands (Central Spain), as well as other lichen species. During spaceflight, the samples were exposed to selected space conditions, that is, the space vacuum, cosmic radiation, and different spectral ranges of solar radiation (λ ≥ 110, ≥ 200, ≥ 290, or ≥ 400 nm, respectively). After retrieval, the algal and fungal metabolic integrity of the samples were evaluated in terms of chlorophyll a fluorescence, ultrastructure, and CO2 exchange rates. Whereas the space vacuum and cosmic radiation did not impair the metabolic activity of the lichens, solar electromagnetic radiation, especially in the wavelength range between 100 and 200 nm, caused reduced chlorophyll a yield fluorescence; however, there was a complete recovery after 72 h of reactivation. All samples showed positive rates of net photosynthesis and dark respiration in the gas exchange experiment. Although the ultrastructure of all flight samples showed some probable stress-induced changes (such as the presence of electron-dense bodies in cytoplasmic vacuoles and between the chloroplast thylakoids in photobiont cells as well as in cytoplasmic vacuoles of the mycobiont cells), we concluded that A. fruticulosa was capable of repairing all space-induced damage. Due to size limitations within the Lithopanspermia hardware, the possibility for replication on the sun-exposed samples was limited, and these first results on the resistance of the lichen symbiosis A. fruticulosa to space conditions and, in particular, on the spectral effectiveness of solar extraterrestrial radiation must be considered preliminary. Further testing in space and under space-simulated conditions will be required. Results of this study indicate that the

  20. Adaptive learning can result in a failure to profit from good conditions: implications for understanding depression

    PubMed Central

    Trimmer, Pete C.; Higginson, Andrew D.; Fawcett, Tim W.; McNamara, John M.; Houston, Alasdair I.

    2015-01-01

    Background and objectives: Depression is a major medical problem diagnosed in an increasing proportion of people and for which commonly prescribed psychoactive drugs are frequently ineffective. Development of treatment options may be facilitated by an evolutionary perspective; several adaptive reasons for proneness to depression have been proposed. A common feature of many explanations is that depressive behaviour is a way to avoid costly effort where benefits are small and/or unlikely. However, this viewpoint fails to explain why low mood persists when the situation improves. We investigate whether a behavioural rule that is adapted to a stochastically changing world can cause inactivity which appears similar to the effect of depression, in that it persists after the situation has improved. Methodology: We develop an adaptive learning model in which an individual has repeated choices of whether to invest costly effort that may result in a net benefit. Investing effort also provides information about the current conditions and rates of change of the conditions. Results: An individual following the optimal behavioural strategy may sometimes remain inactive when conditions are favourable (i.e. when it would be better to invest effort) when it is poorly informed about the current environmental state. Initially benign conditions can predispose an individual to inactivity after a relatively brief period of negative experiences. Conclusions and implications: Our approach suggests that the antecedent factors causing depressed behaviour could go much further back in an individual s history than is currently appreciated. The insights from our approach have implications for the ongoing debate about best treatment options for patients with depressive symptoms. PMID:25916884

  1. Results of attenuation measurements for optical wireless channels under dense fog conditions regarding different wavelengths

    NASA Astrophysics Data System (ADS)

    Flecker, B.; Gebhart, M.; Leitgeb, E.; Sheikh Muhammad, S.; Chlestil, C.

    2006-08-01

    Free Space Optics (FSO) has gained considerable importance in this decade of demand for high bandwidth transmission capabilities. FSO can provide the last mile solution, but the availability and reliability issues concerned with it can not be ignored, and requires thorough investigations. In this work, we present our results about light attenuation at 950 and 850 nm wavelengths in continental city fog conditions with peak values up to 130 dB/km and compare them with attenuation under dense maritime conditions with peak values up to 480 dB/km. Dense fog is the most severe limiting factor in terrestrial optical wireless applications and light propagation in fog has properties in the spatial, spectral and the time domain, which are of importance to free-space optic data communication. In 2004 (within a short term scientific mission of COST 270) measurements of very dense maritime fog and low clouds were made in the mountains of La Turbie, close to the coast of southern France. Using the same equipment, the measurements were continued for the conditions of the continental city of Graz, Austria. This campaign was done in the winter months from 2004 to 2005 and 2005 to 2006 and allows us to compare fog properties for different environments, and the impact of snow fall. We provide detail analysis of a fog and a snow event for better understanding of their attenuation behavior.

  2. Semiconductor quantum wells with BenDaniel-Duke boundary conditions: approximate analytical results

    NASA Astrophysics Data System (ADS)

    Barsan, Victor; Ciornei, Mihaela-Cristina

    2017-01-01

    The Schrödinger equation for a particle moving in a square well potential with BenDaniel-Duke boundary conditions is solved. Using algebraic approximations for trigonometric functions, the transcendental equations of the bound states energy are transformed into tractable, algebraic equations. For the ground state and the first excited state, they are cubic equations; we obtain simple formulas for their physically interesting roots. The case of higher excited states is also analysed. Our results have direct applications in the physics of type I and type II semiconductor heterostructures.

  3. Effect of synthetic conditions on the adsorption properties of the resulting offretite-type zeolite

    NASA Astrophysics Data System (ADS)

    Gorshunova, K. K.; Travkina, O. S.; Kapustin, G. I.; Kustov, L. M.; Pavlov, M. L.; Kutepov, B. I.

    2015-05-01

    The effect of the nature of the silicon-containing component of the reaction mixture and that of the crystallization conditions on characteristics of the resulting offretite-type zeolite powder, including its degree of crystallinity, particle-size distribution, and adsorption properties with respect to toluene, cyclohexane, n-hexane, and water molecules, are considered. The thermal desorption of toluene from cationic forms of the offretite-type zeolite is reported. The K-forms of this zeolite can retain adsorbed toluene up to 300-400°C.

  4. Mineral-catalyzed dehydrogenation of C6 cyclic hydrocarbons: results from experimental studies under hydrothermal conditions

    NASA Astrophysics Data System (ADS)

    Venturi, S.; Tassi, F.; Gould, I.; Shock, E.; Lorance, E. D.; Bockisch, C.; Fecteau, K.

    2015-12-01

    Volatile organic compounds (VOCs) are ubiquitously present in volcanic and hydrothermal gases. Their relative abundances have been demonstrated to be sensitive to physical and chemical parameters, suggesting VOCs as potential tools for evaluating deep reservoir conditions. Nevertheless, reaction pathways for VOC production at hydrothermal conditions are still poorly understood. Reversible catalytic reforming may be responsible for the high abundance of benzene observed in hydrothermal gases relative to saturated hydrocarbons. The dehydrogenation of n-hexane to benzene could proceed with C6 cyclic hydrocarbons as intermediates, as suggested by the relative enrichment in cyclic hydrocarbons observed in gases originating at T <150 °C. In this study, laboratory experiments were carried out to investigate the production of benzene from cyclic hydrocarbons at 300°C and 85 bar. At these conditions in pure water, negligible benzene is produced from cyclohexane after 10 days. The presence of a mineral phase, especially sphalerite, favored the formation of both benzene and cyclohexene. The efficiency of dehydroaromatization reaction increased at increasing mineral/cyclohexane ratio, pointing to a surface catalyzed reaction. The catalytic action of sphalerite on the C-H bonds was confirmed by the large abundance of deuterated cyclohexane resulted in D2O experiments. The same experiment carried out using cyclohexene in pure water mainly produced methyl-cyclopentenes (via isomerization) and cyclohexanol (via oxygenation). In presence of sphalerite, the production of significant amounts of benzene confirmed the critical role of this mineral for the aromatization of cyclic compounds under hydrothermal conditions. Contrarily, products from cyclohexene solution phase oxidation using Cu(II) mainly consisted of oxygenated VOCs.

  5. Salt- and alkaline-tolerance are linked in Acacia.

    PubMed

    Bui, Elisabeth N; Thornhill, Andrew; Miller, Joseph T

    2014-07-01

    Saline or alkaline soils present a strong stress on plants that together may be even more deleterious than alone. Australia's soils are old and contain large, sometimes overlapping, areas of high salt and alkalinity. Acacia and other Australian plant lineages have evolved in this stressful soil environment and present an opportunity to understand the evolution of salt and alkalinity tolerance. We investigate this evolution by predicting the average soil salinity and pH for 503 Acacia species and mapping the response onto a maximum-likelihood phylogeny. We find that salinity and alkalinity tolerance have evolved repeatedly and often together over 25 Ma of the Acacia radiation in Australia. Geographically restricted species are often tolerant of extreme conditions. Distantly related species are sympatric in the most extreme soil environments, suggesting lack of niche saturation. There is strong evidence that many Acacia have distributions affected by salinity and alkalinity and that preference is lineage specific.

  6. Salt- and alkaline-tolerance are linked in Acacia

    PubMed Central

    Bui, Elisabeth N.; Thornhill, Andrew; Miller, Joseph T.

    2014-01-01

    Saline or alkaline soils present a strong stress on plants that together may be even more deleterious than alone. Australia's soils are old and contain large, sometimes overlapping, areas of high salt and alkalinity. Acacia and other Australian plant lineages have evolved in this stressful soil environment and present an opportunity to understand the evolution of salt and alkalinity tolerance. We investigate this evolution by predicting the average soil salinity and pH for 503 Acacia species and mapping the response onto a maximum-likelihood phylogeny. We find that salinity and alkalinity tolerance have evolved repeatedly and often together over 25 Ma of the Acacia radiation in Australia. Geographically restricted species are often tolerant of extreme conditions. Distantly related species are sympatric in the most extreme soil environments, suggesting lack of niche saturation. There is strong evidence that many Acacia have distributions affected by salinity and alkalinity and that preference is lineage specific. PMID:25079493

  7. Intermediate range order in alkaline borate glasses

    NASA Astrophysics Data System (ADS)

    Crupi, C.; Carini, G.; Ruello, G.; D'Angelo, G.

    2016-03-01

    We describe the neutron diffraction patterns of a series of alkaline borate glasses at different metal oxide content. Strong differences are observed in the intermediate range order as a function of the specific alkaline ion and of its concentration. On these results, we propose that the first sharp diffraction peak arises from correlations of atoms of voids and show that the compositional variation of this peak intensity in alkaline borate glasses is due to changes in the distribution of void sizes within the three-dimensional network. We argue that our interpretation in terms of interstitial (empty and/or filled) voids, having different sizes, provides a general explanation for all anomalous behaviours revealed for the first sharp diffraction peak.

  8. Redistribution of wastewater alkalinity with a microbial fuel cell to support nitrification of reject water.

    PubMed

    Modin, Oskar; Fukushi, Kensuke; Rabaey, Korneel; Rozendal, René A; Yamamoto, Kazuo

    2011-04-01

    In wastewater treatment plants, the reject water from the sludge treatment processes typically contains high ammonium concentrations, which constitute a significant internal nitrogen load in the plant. Often, a separate nitrification reactor is used to treat the reject water before it is fed back into the plant. The nitrification reaction consumes alkalinity, which has to be replenished by dosing e.g. NaOH or Ca(OH)(2). In this study, we investigated the use of a two-compartment microbial fuel cell (MFC) to redistribute alkalinity from influent wastewater to support nitrification of reject water. In an MFC, alkalinity is consumed in the anode compartment and produced in the cathode compartment. We use this phenomenon and the fact that the influent wastewater flow is many times larger than the reject water flow to transfer alkalinity from the influent wastewater to the reject water. In a laboratory-scale system, ammonium oxidation of synthetic reject water passed through the cathode chamber of an MFC, increased from 73.8 ± 8.9 mgN/L under open-circuit conditions to 160.1 ± 4.8 mgN/L when a current of 1.96 ± 0.37 mA (15.1 mA/L total MFC liquid volume) was flowing through the MFC. These results demonstrated the positive effect of an MFC on ammonium oxidation of alkalinity-limited reject water.

  9. Improved methane production from waste activated sludge with low organic content by alkaline pretreatment at pH 10.

    PubMed

    Feng, L Y; Yang, L Q; Zhang, L X; Chen, H L; Chen, J

    2013-01-01

    Sludge with low organic content always results in an unsatisfactory performance, even failure of anaerobic digestion. The alkaline pretreatment effect on anaerobic digestion of sludge with low organic content has seldom been studied although it gives many benefits for sludge with high organic content. In this study the influence of alkaline pretreatment (pH 10, an effective alkaline pH) on the solubilization and methane production from waste activated sludge (WAS) with low organic content was investigated. Results from biochemical methane potential (BMP) experiments showed that anaerobic biodegradability of WAS was greatly improved by alkaline pretreatment at pH 10. Methane production from the current WAS under conditions of pretreatment time 4 h and digestion time 15 d was 139.6 mL/g VS (volatile solids), much higher than that from the unpretreated WAS with digestion time of 20 d (75.2 mL/g VS). Also, the solubilization of WAS was significantly accelerated by alkaline pretreatment. Mechanism exploration indicated that the general activities of anaerobic microorganisms, specific activities of key enzymes and the amounts of methanogens were enhanced by alkaline pretreatment at pH 10, showing good agreement with methane production.

  10. Influence of Earth crust composition on continental collision style in Precambrian conditions: Results of supercomputer modelling

    NASA Astrophysics Data System (ADS)

    Zavyalov, Sergey; Zakharov, Vladimir

    2016-04-01

    A number of issues concerning Precambrian geodynamics still remain unsolved because of uncertainity of many physical (thermal regime, lithosphere thickness, crust thickness, etc.) and chemical (mantle composition, crust composition) parameters, which differed considerably comparing to the present day values. In this work, we show results of numerical supercomputations based on petrological and thermomechanical 2D model, which simulates the process of collision between two continental plates, each 80-160 km thick, with various convergence rates ranging from 5 to 15 cm/year. In the model, the upper mantle temperature is 150-200 ⁰C higher than the modern value, while the continental crust radiogenic heat production is higher than the present value by the factor of 1.5. These settings correspond to Archean conditions. The present study investigates the dependence of collision style on various continental crust parameters, especially on crust composition. The 3 following archetypal settings of continental crust composition are examined: 1) completely felsic continental crust; 2) basic lower crust and felsic upper crust; 3) basic upper crust and felsic lower crust (hereinafter referred to as inverted crust). Modeling results show that collision with completely felsic crust is unlikely. In the case of basic lower crust, a continental subduction and subsequent continental rocks exhumation can take place. Therefore, formation of ultra-high pressure metamorphic rocks is possible. Continental subduction also occurs in the case of inverted continental crust. However, in the latter case, the exhumation of felsic rocks is blocked by upper basic layer and their subsequent interaction depends on their volume ratio. Thus, if the total inverted crust thickness is about 15 km and the thicknesses of the two layers are equal, felsic rocks cannot be exhumed. If the total thickness is 30 to 40 km and that of the felsic layer is 20 to 25 km, it breaks through the basic layer leading to

  11. Effective alkaline metal-catalyzed oxidative delignification of hybrid poplar

    SciTech Connect

    Bhalla, Aditya; Bansal, Namita; Stoklosa, Ryan J.; Fountain, Mackenzie; Ralph, John; Hodge, David B.; Hegg, Eric L.

    2016-02-09

    from untreated poplar. In conclusion: This study demonstrated that the fed-batch, two-stage Cu-AHP pretreatment process was effective in pretreating hybrid poplar for its conversion into fermentable sugars. Results showed sugar yields near the theoretical maximum were achieved from enzymatically hydrolyzed hybrid poplar by incorporating an alkaline extraction step prior to pretreatment and by efficiently utilizing H2O2 during the Cu-AHP process. Significantly, this study reports high sugar yields from woody biomass treated with an AHP pretreatment under mild reaction conditions.

  12. Effective alkaline metal-catalyzed oxidative delignification of hybrid poplar

    DOE PAGES

    Bhalla, Aditya; Bansal, Namita; Stoklosa, Ryan J.; ...

    2016-02-09

    -batch, two-stage Cu-AHP pretreatment process was effective in pretreating hybrid poplar for its conversion into fermentable sugars. Results showed sugar yields near the theoretical maximum were achieved from enzymatically hydrolyzed hybrid poplar by incorporating an alkaline extraction step prior to pretreatment and by efficiently utilizing H2O2 during the Cu-AHP process. Significantly, this study reports high sugar yields from woody biomass treated with an AHP pretreatment under mild reaction conditions.« less

  13. The results of the campaign for evaluating sphygmomanometers accuracy and their physical conditions

    PubMed

    Mion; Pierin; Alavarce; Vasconcellos

    2000-01-01

    OBJECTIVE: To evaluate the sphygmomanometers calibration accuracy and the physical conditions of the cuff-bladder, bulb, pump, and valve. METHODS: Sixty hundred and forty five aneroid sphygmomanometers were evaluated, 521 used in private practice and 124 used in hospitals. Aneroid manometers were tested against a properly calibrated mercury manometer and were considered calibrated when the error was < or = 3 mm Hg. The physical conditions of the cuffs-bladder, bulb, pump, and valve were also evaluated. RESULTS: Of the aneroid sphygmomanometers tested, 51% of those used in private practice and 56% of those used in hospitals were found to be not accurately calibrated. Of these, the magnitude of inaccuracy ranged from 4 to 8 mm Hg in 70% and 51% of the devices, respectively. The problems found in the cuffs--bladders, bulbs, pumps, and valves of the private practice and hospital devices were bladder damage (34% vs. 21%, respectively), holes/leaks in the bulbs (22% vs. 4%, respectively), and rubber aging (15% vs. 12%, respectively). Of the devices tested, 72% revealed at least one problem interfering with blood pressure measurement accuracy. CONCLUSION: Most of the manometers evaluated, whether used in private practice or in hospitals, were found to be inaccurate and unreliable, and their use may jeopardize the diagnosis and treatment of arterial hypertension.

  14. The results of the Campaign for evaluating sphygmomanometers accuracy and their physical conditions.

    PubMed

    Mion; Pierin; Alavarce; Vasconcellos

    2000-01-01

    OBJECTIVE: To evaluate the sphygmomanometers calibration accuracy and the physical conditions of the cuff-bladder, bulb, pump, and valve. METHODS: Sixty hundred and forty five aneroid sphygmomanometers were evaluated, 521 used in private practice and 124 used in hospitals. Aneroid manometers were tested against a properly calibrated mercury manometer and were considered calibrated when the error was conditions of the cuffs-bladder, bulb, pump, and valve were also evaluated. RESULTS: Of the aneroid sphygmomanometers tested, 51% of those used in private practice and 56% of those used in hospitals were found to be not accurately calibrated. Of these, the magnitude of inaccuracy ranged from 4 to 8mm Hg in 70% and 51% of the devices, respectively. The problems found in the cuffs - bladders, bulbs, pumps, and valves of the private practice and hospital devices were bladder damage (34% vs. 21%, respectively), holes/leaks in the bulbs (22% vs. 4%, respectively), and rubber aging (15% vs. 12%, respectively). Of the devices tested, 72% revealed at least one problem interfering with blood pressure measurement accuracy. CONCLUSION: Most of the manometers evaluated, whether used in private practice or in hospitals, were found to be inaccurate and unreliable, and their use may jeopardize the diagnosis and treatment of arterial hypertension.

  15. Preliminary results on the ability of pentatomidae to transfer fire blight Erwinia amylovora under controlled conditions.

    PubMed

    Peusens, G; Schoofs, H; Deckers, T; Belien, T

    2013-01-01

    With their piercing-sucking mouthparts stink bugs (Heteroptera: Pentatomidae), a major pest in especially organic orchards, create wounds in fruit of pear trees. As Erwinia amylovora (Burrill, Winslow et al.), a wide spread bacterial disease affecting many rosaceous plants including pome fruit trees and hawthorn, enters through openings in flowers, leaves, shoots and fruit, feeding punctures caused by these bugs might be inoculated with Erwinia bacteria. In order to investigate the ability of the bugs Pentotoma rufipes L. and Polomena prasina L. to transmit fire blight, insects were caught in an organically managed orchard without fire blight, brought into contact with artificially inoculated immature pear fruit/slices and transferred to healthy, mechanically wounded pear fruit/slices. After an incubation period potential transmission of bacteria was examined by evaluation of symptom expression (necrosis, ooze production). To assess the presence of bacteria on the exoskeleton of the tested bugs, all bugs were forced to walk on a semiselective nutrient agar medium. In another experiment the viability of Ea on the exoskeleton was tested -after previous contact with ooze- through washing and plating of the wash water. All experiments were conducted under optimal climatological conditions and according to quarantine standards. Results demonstrated the ability of stink bugs to transfer E. amylovora to fruit and the viability of bacteria on stink bugs externally - both under lab conditions.

  16. Recovery of phosphorus and nitrogen from alkaline hydrolysis supernatant of excess sludge by magnesium ammonium phosphate.

    PubMed

    Bi, Wei; Li, Yiyong; Hu, Yongyou

    2014-08-01

    Magnesium ammonium phosphate (MAP) method was used to recover orthophosphate (PO₄(3-)-P) and ammonium nitrogen (NH4(+)-N) from the alkaline hydrolysis supernatant of excess sludge. To reduce alkali consumption and decrease the pH of the supernatant, two-stage alkaline hydrolysis process (TSAHP) was designed. The results showed that the release efficiencies of PO₄(3-)-P and NH₄(+)-N were 41.96% and 7.78%, respectively, and the pH of the supernatant was below 10.5 under the running conditions with initial pH of 13, volume ratio (sludge dosage/water dosage) of 1.75 in second-stage alkaline hydrolysis reactor, 20 g/L of sludge concentration in first-stage alkaline hydrolysis reactor. The order of parameters influencing MAP reaction was analyzed and the optimized conditions of MAP reaction were predicted through the response surface methodology. The recovery rates of PO₄(3-)-P and NH₄(+)-N were 46.88% and 16.54%, respectively under the optimized conditions of Mg/P of 1.8, pH 9.7 and reaction time of 15 min.

  17. Improved volatile fatty acids anaerobic production from waste activated sludge by pH regulation: Alkaline or neutral pH?

    PubMed

    Ma, Huijun; Chen, Xingchun; Liu, He; Liu, Hongbo; Fu, Bo

    2016-02-01

    In this study, the anaerobic fermentation was carried out for volatile fatty acids (VFAs) production at different pH (between 7.0 and 10.0) conditions with untreated sludge and heat-alkaline pretreated waste activated sludge. In the fermentation with untreated sludge, the extent of hydrolysis of organic matters and extent of acidification at alkaline pH are 54.37% and 30.37%, respectively, resulting in the highest VFAs yield at 235.46mg COD/gVS of three pH conditions. In the fermentation with heat-alkaline pretreated sludge, the acidification rate and VFAs yield at neutral pH are 30.98% and 240.14mg COD/gVS, respectively, which are higher than that at other pH conditions. With the glucose or bovine serum albumin as substrate for VFAs production, the neutral pH showed a higher VFAs concentration than the alkaline pH condition. The results of terminal restriction fragment length polymorphism (T-RFLP) analysis indicated that the alkaline pH caused low microbial richness. Based on the results in this study, we demonstrated that the alkaline pH is favor of hydrolysis of organic matter in sludge while neutral pH improved the acidogenesis for the VFAs production from sludge. Our finding is obvious different to the previous research and helpful for the understanding of how heat-alkaline pretreatment and alkaline fermentation influence the VFAs production, and beneficial to the development of VFAs production process.

  18. Enhancement of antibody response by one-trial conditioning: contrasting results using different antigens.

    PubMed

    Espinosa, Enrique; Calderas, Tania; Flores-Muciño, Oscar; Pérez-García, Georgina; Vázquez-Camacho, Ana C; Bermúdez-Rattoni, Federico

    2004-01-01

    New research in conditioned enhancement of antibody response requires a general paradigm effective with different antigens. In this experiment series we applied a one-trial protocol using keyhole limpet hemocyanin immunization as an unconditioned stimulus. Several different conditions were tested. Two different times between conditioning and test trial, two relevant antigen doses and the use of an antigen booster during test trial were investigated. We did not find a conditioned effect in any of the conditions used. In contrast, we found a reliable albeit modest conditioned effect using hen egg lysozyme as unconditioned stimulus. By comparing these and other findings we conclude that the number of conditioning trials is a possible requirement for a more reliable conditioning of antibody response.

  19. MERCURIC CHLORIDE CAPTURE BY ALKALINE SORBENTS

    EPA Science Inventory

    The paper gives results of bench-scale mechanistic studies of mercury/sorbent reactions that showed that mercuric chloride (HgC12) is readily adsorbed by alkaline sorbents, which may offers a less expensive alternative to the use of activated carbons. A laboratory-scale, fixed-b...

  20. Results comparison and model validation for flood loss functions in Australian geographical conditions

    NASA Astrophysics Data System (ADS)

    Hasanzadeh Nafari, R.; Ngo, T.; Lehman, W.

    2015-06-01

    Rapid urbanisation, climate change and unsustainable developments are increasing the risk of floods, namely flood frequency and intensity. Flood is a frequent natural hazard that has significant financial consequences for Australia. The emergency response system in Australia is very successful and has saved many lives over the years. However, the preparedness for natural disaster impacts in terms of loss reduction and damage mitigation has been less successful. This study aims to quantify the direct physical damage to residential structures that are prone to flood phenomena in Australia. In this paper, the physical consequences of two floods from Queensland have been simulated, and the results have been compared with the performance of two selected methodologies and one newly derived model. Based on this analysis, the adaptability and applicability of the selected methodologies will be assessed in terms of Australian geographical conditions. Results obtained from the new empirically-based function and non-adapted methodologies indicate that it is apparent that the precision of flood damage models are strongly dependent on selected stage damage curves, and flood damage estimation without model validation results in inaccurate prediction of losses. Therefore, it is very important to be aware of the associated uncertainties in flood risk assessment, especially if models have not been adapted with real damage data.

  1. Reduction of indicator and pathogenic microorganisms in pig manure through fly ash and lime addition during alkaline stabilization.

    PubMed

    Wong, Jonathan W C; Selvam, Ammaiyappan

    2009-09-30

    A pilot scale study was conducted to evaluate the effect of lime and alkaline coal fly ash (CFA) on the reduction of pathogens in pig manure during alkaline stabilization and suppression of re-growth during post-stabilization incubation. Pig manure was mixed with CFA at 25%, 33% and 50%, and a control without fly ash was maintained. To these manure-ash mixtures, lime was added at the rate of 2% or 4% and incubated for 8 days. During the incubation, the population of Salmonella, fecal coliforms, Escherichia coli, fecal Streptococcus and total bacteria were enumerated. After the alkaline stabilization process, the mixtures were incubated under green house condition to evaluate the re-growth of pathogens. During the 8-day alkaline stabilization, Salmonella, fecal coliforms, E. coli and fecal Streptococcus were completely devitalized in manure-ash-lime mixtures, whereas in the control, incubation reduced the pathogen and total bacterial population by 2-3 logs. Fecal streptococcus was destructed within 4 days of alkaline stabilization, whereas other pathogens needed 8 days for their destruction. During the incubation in green house, an increase in the population of the pathogens and total bacteria was observed. Results indicate that alkaline stabilization of pig manure with lime at 4% and CFA at 50% is effective in devitalizing the pathogens and reducing the post-stabilization re-growth.

  2. Effect of the stringency of conditions on caloric test results in healthy subjects.

    PubMed

    Krstulovic, Claudio; Tulsidas Mahtani, Bharti; Atrache Al Attrache, Nabil; Pérez-Garrigues, Herminio

    The caloric test is widely used to assess vestibular function, but the conditions in which it is performed can vary. Caloric nystagmus obtained in 57 healthy subjects were compared: 24 subjects studied in ideal conditions and 33 subjects in non-ideal conditions. A statistically significant decrease in the slow phase velocity of the 4 irrigations performed on the subjects in non-ideal conditions was observed. This must be considered, especially in subjects with suspected bilateral involvement. Stringent conditions reduce the risk of misdiagnosis with bilateral deficit.

  3. Low pH alkaline chemical formulations

    SciTech Connect

    French, T.R.; Peru, D.A.; Thornton, S.D.

    1989-01-01

    This report describes the development of a surfactant-enhanced alkaline flooding system that is applicable to specific reservoir conditions in Wilmington (California) field. The cost of the chemicals for an ASP (alkali/surfactant/polymer) flood is calculated to be $3.90/bbl of oil produced, with 78% of that cost attributable to polymer. This research included phase behavior tests, oil displacement tests, mineral dissolution tests, and adsorption measurements. It was discovered that consumption of low pH alkalis is low enough in the Wilmington field to be acceptable. In addition, alkali dramatically reduced surfactant adsorption and precipitation. A mixture of NaHCO3 and Na2CO3 was recommended for use as a preflush and in the ASP formulation. Research was also conducted on the synergistic effect that occurs when a mixture of alkali and synthetic surfactant contacts crude oil. It appears that very low IFT is predominantly a result of the activation of the natural surfactants present in the Wilmington oil, and the sustained low IFT is primarily the result of the synthetic surfactant. It also appears that removal of acids from the crude oil by the alkali renders the oil more interfacially reactive to synthetic surfactant. These phenomena help to explain the synergism that results from combining alkali and synthetic surfactant into a single oil recovery formulation. 19 refs., 24 figs., 10 tabs.

  4. Alkaline phosphatase of Physarum polycephalum is insoluble.

    PubMed

    Furuhashi, Kiyoshi

    2008-02-01

    The plasmodia of Physarum polycephalum grow as multinucleated cells in the presence of sufficient humidity and nutriment. Under non-illuminating conditions, stresses such as low temperature or high concentrations of salts transform the plasmodia into spherules whereas dehydration induces sclerotization. Some phosphatases including protein phosphatase and acid phosphatase have been purified from the plasmodia, but alkaline phosphatase remains to be elucidated. Phosphatase of the plasmodia, spherules and sclerotia was visualized by electrophoresis gel-staining assay using 5-bromo-4-chloro-3-indolyl phosphate. Insoluble fractions of the sclerotia were abundant in phosphatase activity. The phosphatase which was extracted by nonionic detergent was subjected to column chromatography and preparative electrophoresis. Purified phosphatase showed the highest activity at pH 8.8, indicating that this enzyme belongs to alkaline phosphatase. The apparent molecular mass from sodium dodecyl sulfate-polyacrylamide gel electrophoresis under non-reducing condition was estimated to be 100 kDa whereas that under reducing was 105 kDa. An amount of 1% sodium dodecyl sulfate or 0.5 M NaCl had no effects on the activity although the phosphatase showed heat instability, Mg(2+)-dependency and sensitivity to 2-glycerophosphate or NaF. The extracting conditions and enzymatic properties suggest that this alkaline phosphatase which is in a membrane-bound form plays important roles in phosphate metabolism.

  5. Sport Engagement by Accelerometry under Field Conditions in German Adolescents: Results from GINIPlus

    PubMed Central

    Smith, Maia; Berdel, Dietrich; Nowak, Dennis; Heinrich, Joachim; Schulz, Holger

    2015-01-01

    Introduction Sporting activities differ in their ability to promote moderate-to-vigorous physical activity (MVPA). To assess adolescents’ engagement in sport under field conditions we used accelerometers to measure their MVPA levels during sport. We pay special attention to differences between team and individual sport and between common sports. Methods Diary data and 7-day accelerometry from 1054 Germans ages 15–17 were combined to measure physical activity. 1373 diaried episodes of more than 40 common sports were identified from 626 participants and grouped into team and individual sport. We modeled the effect of team and individual sport, and described levels of MVPA and episodes of no MVPA for all recorded sports. Results German boys and girls averaged 43 (SD 21) and 37 (SD 24) minutes MVPA per day. Boys got 2.2 times as much MVPA per minute during team compared to individual sport (p<0.0001) but there was no significant difference for girls. Percent of time spent in MVPA during sport ranged from 6% for weight training to 74% for jogging, with individual sports averaging 10–30% and team sports 30–50%. 11% of sport episodes had no MVPA: half of episodes of cycling, 5% of jogging, and none for tennis or badminton. An episode of individual sport was 17 times more likely to have no MVPA than an episode of team sport (p<0.0001). Conclusion Under field condition, adolescents were active for only a fraction of diaried sporting time. As measured by accelerometry, individual sport often produced no MVPA. Characteristics of the sport, such as team vs. individual, were more predictive of MVPA than were characteristics of the participant, such as background activity levels. PMID:26291984

  6. Hybridization within Saccharomyces Genus Results in Homoeostasis and Phenotypic Novelty in Winemaking Conditions.

    PubMed

    da Silva, Telma; Albertin, Warren; Dillmann, Christine; Bely, Marina; la Guerche, Stéphane; Giraud, Christophe; Huet, Sylvie; Sicard, Delphine; Masneuf-Pomarede, Isabelle; de Vienne, Dominique; Marullo, Philippe

    2015-01-01

    Despite its biotechnological interest, hybridization, which can result in hybrid vigor, has not commonly been studied or exploited in the yeast genus. From a diallel design including 55 intra- and interspecific hybrids between Saccharomyces cerevisiae and S. uvarum grown at two temperatures in enological conditions, we analyzed as many as 35 fermentation traits with original statistical and modeling tools. We first showed that, depending on the types of trait--kinetics parameters, life-history traits, enological parameters and aromas -, the sources of variation (strain, temperature and strain * temperature effects) differed in a large extent. Then we compared globally three groups of hybrids and their parents at two growth temperatures: intraspecific hybrids S. cerevisiae * S. cerevisiae, intraspecific hybrids S. uvarum * S. uvarum and interspecific hybrids S. cerevisiae * S. uvarum. We found that hybridization could generate multi-trait phenotypes with improved oenological performances and better homeostasis with respect to temperature. These results could explain why interspecific hybridization is so common in natural and domesticated yeast, and open the way to applications for wine-making.

  7. Hybridization within Saccharomyces Genus Results in Homoeostasis and Phenotypic Novelty in Winemaking Conditions

    PubMed Central

    Dillmann, Christine; Bely, Marina; la Guerche, Stéphane; Giraud, Christophe; Huet, Sylvie; Sicard, Delphine; Masneuf-Pomarede, Isabelle; de Vienne, Dominique; Marullo, Philippe

    2015-01-01

    Despite its biotechnological interest, hybridization, which can result in hybrid vigor, has not commonly been studied or exploited in the yeast genus. From a diallel design including 55 intra- and interspecific hybrids between Saccharomyces cerevisiae and S. uvarum grown at two temperatures in enological conditions, we analyzed as many as 35 fermentation traits with original statistical and modeling tools. We first showed that, depending on the types of trait – kinetics parameters, life-history traits, enological parameters and aromas –, the sources of variation (strain, temperature and strain * temperature effects) differed in a large extent. Then we compared globally three groups of hybrids and their parents at two growth temperatures: intraspecific hybrids S. cerevisiae * S. cerevisiae, intraspecific hybrids S. uvarum * S. uvarum and interspecific hybrids S. cerevisiae * S. uvarum. We found that hybridization could generate multi-trait phenotypes with improved oenological performances and better homeostasis with respect to temperature. These results could explain why interspecific hybridization is so common in natural and domesticated yeast, and open the way to applications for wine-making. PMID:25946464

  8. Experimental demonstration of quantitation errors in MR spectroscopy resulting from saturation corrections under changing conditions

    NASA Astrophysics Data System (ADS)

    Galbán, Craig J.; Ellis, Scott J.; Spencer, Richard G. S.

    2003-04-01

    Metabolite concentration measurements in in vivo NMR are generally performed under partially saturated conditions, with correction for partial saturation performed after data collection using a measured saturation factor. Here, we present an experimental test of the hypothesis that quantitation errors can occur due to application of such saturation factor corrections in changing systems. Thus, this extends our previous theoretical work on quantitation errors due to varying saturation factors. We obtained results for two systems frequently studied by 31P NMR, the ischemic rat heart and the electrically stimulated rat gastrocnemius muscle. The results are interpreted in light of previous theoretical work which defined the degree of saturation occurring in a one-pulse experiment for a system with given spin-lattice relaxation times, T1s, equilibrium magnetizations, M0s, and reaction rates. We found that (i) the assumption of constancy of saturation factors leads to quantitation errors on the order of 40% in inorganic phosphate; (ii) the dominant contributor to the quantitation errors in inorganic phosphate is most likely changes in T1; (iii) T1 and M0 changes between control and intervention periods, and chemical exchange contribute to different extents to quantitation errors in phosphocreatine and γ-ATP; (iv) relatively small increases in interpulse delay substantially decreased quantitation errors for metabolites in ischemic rat hearts; (v) random error due to finite SNR led to approximately 4% error in quantitation, and hence was a substantially smaller contributor than were changes in saturation factors.

  9. Coupling the Alkaline-Surfactant-Polymer Technology and The Gelation Technology to Maximize Oil Production

    SciTech Connect

    Malcolm Pitts; Jie Qi; Dan Wilson; David Stewart; Bill Jones

    2005-10-01

    Gelation technologies have been developed to provide more efficient vertical sweep efficiencies for flooding naturally fractured oil reservoirs or more efficient areal sweep efficiency for those with high permeability contrast ''thief zones''. The field proven alkaline-surfactant-polymer technology economically recovers 15% to 25% OOIP more oil than waterflooding from swept pore space of an oil reservoir. However, alkaline-surfactant-polymer technology is not amenable to naturally fractured reservoirs or those with thief zones because much of injected solution bypasses target pore space containing oil. This work investigates whether combining these two technologies could broaden applicability of alkaline-surfactant-polymer flooding into these reservoirs. A prior fluid-fluid report discussed interaction of different gel chemical compositions and alkaline-surfactant-polymer solutions. Gel solutions under dynamic conditions of linear corefloods showed similar stability to alkaline-surfactant-polymer solutions as in the fluid-fluid analyses. Aluminum-polyacrylamide, flowing gels are not stable to alkaline-surfactant-polymer solutions of either pH 10.5 or 12.9. Chromium acetate-polyacrylamide flowing and rigid flowing gels are stable to subsequent alkaline-surfactant-polymer solution injection. Rigid flowing chromium acetate-polyacrylamide gels maintained permeability reduction better than flowing chromium acetate-polyacrylamide gels. Silicate-polyacrylamide gels are not stable with subsequent injection of either a pH 10.5 or a 12.9 alkaline-surfactant-polymer solution. Chromium acetate-xanthan gum rigid gels are not stable to subsequent alkaline-surfactant-polymer solution injection. Resorcinol-formaldehyde gels were stable to subsequent alkaline-surfactant-polymer solution injection. When evaluated in a dual core configuration, injected fluid flows into the core with the greatest effective permeability to the injected fluid. The same gel stability trends to subsequent

  10. Post-impact climate conditions on early Mars: preliminary results from GCM simulations

    NASA Astrophysics Data System (ADS)

    Steakley, Kathryn; Murphy, Jim; Kahre, Melinda A.; Haberle, Robert

    2016-10-01

    Observations imply that liquid water was stable on Mars' surface during the late Noachian/early Hesperian era, with valley networks forming roughly 3.5-3.75 billion years ago, possibly from precipitation and runoff (Fassett & Head 2008, Icarus 195, 61; Hynek et al., 2010, JGR Planets, 115, E09008). Climate models, however, struggle to reproduce such warm conditions (Forget et al., 2013, Icarus 21, 81). Volcanism and impacts have been suggested as mechanisms of either inducing a warm and wet environment or causing local melting in a cold and wet environment. Comets and asteroids are capable of injecting into the atmosphere both kinetic energy from the impact and water from the object itself and from vaporized surface and subsurface ice. Segura et al. (2008, JGR Planets 113, E11007) find using a 1-D atmospheric model that significant rainfall and periods of above-freezing temperatures lasting months to years can follow impacts of objects between 30 and 100 km in diameter. We revisit this work utilizing a 3-D global climate model (GCM) to consider the effects of dynamics, topography, global surface ice variations, etc. We present preliminary results from the NASA ARC Mars GCM investigating global temperature and precipitation behavior in a post-impact, early Mars environment.

  11. [A modification of the Aulhorn flicker test with results of physiological and pathological conditions].

    PubMed

    Watanabe, I; Iijima, H; Miwa, M; Shimamoto, R

    1993-01-01

    The Aulhorn flicker test measures the subjective brightness of various frequencies of flickering light. We modified an Aulhorn flicker test with light emitting diode (LED) and the results of 21 normal eyes and 18 affected eyes (7 eyes with idiopathic optic neuritis, one eye with rhinogenous optic neuropathy (ethmoid sinus mucocele), two eyes with preoperative pituitary tumor, one eye with empty sella, one eye with anterior ischemic optic neuropathy, one eye with syphilitic optic neuritis, five eyes with primary open angle glaucoma) were presented. All normal eyes showed the Brücke-Bartley effect which refers to an enhanced subjective brightness at lower frequencies. Six eyes with idiopathic optic neuritis and one eye with rhinogenous optic neuropathy in the acute stage demonstrated the Aulhorn effect which refers to a reduced subjective brightness at lower frequencies. Four eyes with the Aulhorn effect that were followed up showed less prominent Aulhorn effect. One eye with idiopathic optic neuritis and 10 eyes with other conditions did not show the Aulhorn effect. It was suggested that the modified Aulhorn flicker test with LED is a useful method for diagnosis of optic neuritis in the acute stage.

  12. A PROBABILISTIC ASSESSMENT OF BENTHIC CONDITION OF CALIFORNIA ESTUARIES: RESULTS FROM THE NATIONAL COASTAL ASSESSMENT 1999

    EPA Science Inventory

    As part of the National Coastal Assessment, the Environmental Monitoring and Assessment Program of EPA is conducting a three year evaluation of benthic habitat condition of California estuaries. In 1999, probabilistic sampling for a variety of biotic and abiotic condition indica...

  13. Performing Movement Sequences with Knowledge of Results under Different Visual Conditions in Adults with Down Syndrome.

    ERIC Educational Resources Information Center

    Virji-Babul, Naznin; Lloyd, Jennifer E. V.; Van Gyn, Geraldine

    2003-01-01

    This study examined the learning of movement sequences in 10 adults with Down syndrome (DS) under two visual information conditions. Although DS individuals were significantly slower than neurologically typical participants, mean reaction and movement times were not affected by the visual information condition in either group. DS individuals…

  14. Alkaline battery, separator therefore

    NASA Technical Reports Server (NTRS)

    Schmidt, George F. (Inventor)

    1980-01-01

    An improved battery separator for alkaline battery cells has low resistance to electrolyte ion transfer and high resistance to electrode ion transfer. The separator is formed by applying an improved coating to an electrolyte absorber. The absorber, preferably, is a flexible, fibrous, and porous substrate that is resistant to strong alkali and oxidation. The coating composition includes an admixture of a polymeric binder, a hydrolyzable polymeric ester and inert fillers. The coating composition is substantially free of reactive fillers and plasticizers commonly employed as porosity promoting agents in separator coatings. When the separator is immersed in electrolyte, the polymeric ester of the film coating reacts with the electrolyte forming a salt and an alcohol. The alcohol goes into solution with the electrolyte while the salt imbibes electrolyte into the coating composition. When the salt is formed, it expands the polymeric chains of the binder to provide a film coating substantially permeable to electrolyte ion transfer but relatively impermeable to electrode ion transfer during use.

  15. Predicting species’ tolerance to salinity and alkalinity using distribution data and geochemical modelling: a case study using Australian grasses

    PubMed Central

    Saslis-Lagoudakis, C. Haris; Hua, Xia; Bui, Elisabeth; Moray, Camile; Bromham, Lindell

    2015-01-01

    Background and Aims Salt tolerance has evolved many times independently in different plant groups. One possible explanation for this pattern is that it builds upon a general suite of stress-tolerance traits. If this is the case, then we might expect a correlation between salt tolerance and other tolerances to different environmental stresses. This association has been hypothesized for salt and alkalinity tolerance. However, a major limitation in investigating large-scale patterns of these tolerances is that lists of known tolerant species are incomplete. This study explores whether species’ salt and alkalinity tolerance can be predicted using geochemical modelling for Australian grasses. The correlation between taxa found in conditions of high predicted salinity and alkalinity is then assessed. Methods Extensive occurrence data for Australian grasses is used together with geochemical modelling to predict values of pH and electrical conductivity to which species are exposed in their natural distributions. Using parametric and phylogeny-corrected tests, the geochemical predictions are evaluated using a list of known halophytes as a control, and it is determined whether taxa that occur in conditions of high predicted salinity are also found in conditions of high predicted alkalinity. Key Results It is shown that genera containing known halophytes have higher predicted salinity conditions than those not containing known halophytes. Additionally, taxa occurring in high predicted salinity tend to also occur in high predicted alkalinity. Conclusions Geochemical modelling using species’ occurrence data is a potentially useful approach to predict species’ relative natural tolerance to challenging environmental conditions. The findings also demonstrate a correlation between salinity tolerance and alkalinity tolerance. Further investigations can consider the phylogenetic distribution of specific traits involved in these ecophysiological strategies, ideally by

  16. Arizona Teacher Working Conditions: Designing Schools for Educator and Student Success. Results of the 2006 Phase-In Teacher Working Conditions Survey

    ERIC Educational Resources Information Center

    Hirsch, Eric; Emerick, Scott

    2006-01-01

    Many schools across the country face persistent teacher working condition challenges that are closely related to high teacher turnover rates and chronic difficulties in recruiting and retaining teachers. Center for Teaching Quality (CTQ) research examining working conditions survey results in both North Carolina and South Carolina demonstrates…

  17. Modification of Pulsed Electric Field Conditions Results in Distinct Activation Profiles of Platelet-Rich Plasma

    PubMed Central

    Frelinger, Andrew L.; Gerrits, Anja J.; Garner, Allen L.; Torres, Andrew S.; Caiafa, Antonio; Morton, Christine A.; Berny-Lang, Michelle A.; Carmichael, Sabrina L.; Neculaes, V. Bogdan; Michelson, Alan D.

    2016-01-01

    presence of platelet-derived microparticles, platelets, and platelet aggregates whereas SMHEF pulses primarily resulted in platelet-derived microparticles. Microparticles and platelets in PRP activated with SMLEF bipolar pulses had significantly lower annexin V-positivity than those following SMHEF activation. In contrast, the % P-selectin positivity and surface P-selectin expression (MFI) for platelets and microparticles in SMLEF bipolar pulse activated PRP was significantly higher than that in SMHEF-activated PRP, but not significantly different from that produced by thrombin activation. Higher levels of EGF were observed following either SMLEF bipolar pulses or SMHEF pulses of PRP than after bovine thrombin activation while VEGF, PDGF, and PF4 levels were similar with all three activating conditions. Cell proliferation was significantly increased by releasates of both SMLEF bipolar pulse and SMHEF pulse activated PRP compared to plasma alone. Conclusions PEF activation of PRP at bipolar low vs. monopolar high field strength results in differential platelet-derived microparticle production and activation of platelet surface procoagulant markers while inducing similar release of growth factors and similar capacity to induce cell proliferation. Stimulation of PRP with SMLEF bipolar pulses is gentler than SMHEF pulses, resulting in less platelet microparticle generation but with overall activation levels similar to that obtained with thrombin. These results suggest that PEF provides the means to alter, in a controlled fashion, PRP properties thereby enabling evaluation of their effects on wound healing and clinical outcomes. PMID:27556645

  18. Allogeneic stem cell transplantation using non-myeloablative conditioning regimens: results of the Mexican approach.

    PubMed

    Ruiz-Argüelles, Guillermo J

    2002-08-01

    We have used a novel method to conduct non-myeloablative stem cell transplantation (NST), making the following changes in previous methods: Use of the cheapest conditioning drugs, tailored number of apheresis sessions in the donors, elimination of ganciclovir and IgG, outpatient conduction when possible, diminished number of transfusions of blood products and diminished number of donor lymphocyte infusions. With this method, we have prospectively conducted 70 allografts in patients with different diseases: Chronic myelogenous leukemia, acute myelogenous leukemia, acute lymphoblastic leukemia, myelodysplasia, thalassemia major, relapsed Hodgkins disease, Blackfan-Diamond syndrome and aplastic anemia. In them, the median granulocyte recovery time to 0.5 x 10(9)/L was 11 d, whereas the median platelet recovery time to 20 x 10(9)/L was 12 d. Twenty patients did not need red blood cell transfusions and 17 did not need platelet transfusions. In 55 individuals (78%), the procedure could be completed fully on an outpatient basis. Follow-up times range between 30 and 800 d.: Four patients failed to engraft and recovered endogenous hemopoiesis; 16 patients (23%) developed acute graft versus-host disease (GVHD) whereas 28 (49%) developed chronic GVHD. Thirty two patients (47%) have died: 21 with a relapsing disease and seven as a result of GVHD; the median post-trasplant survival (SV) was 420 d., whereas the 12-mo. SV was 42%. The 100-day mortality was 3.8% and the transplant-related mortality was 14.2%. The median cost of the allografts was 18,000.00 US dollars. This method could be particularly adequate in developing countries, where very few individuals can afford the cost of a conventional bone marrow transplantation procedure.

  19. Rapid changes in water hardness and alkalinity: Calcite formation is lethal to Daphnia magna.

    PubMed

    Bogart, Sarah J; Woodman, Samuel; Steinkey, Dylan; Meays, Cindy; Pyle, Greg G

    2016-07-15

    There is growing concern that freshwater ecosystems may be negatively affected by ever-increasing anthropogenic inputs of extremely hard, highly alkaline effluent containing large quantities of Ca(2+), Mg(2+), CO3(2-), and HCO3(-) ions. In this study, the toxicity of rapid and extreme shifts in water hardness (38-600mg/L as CaCO3) and alkalinity (30-420mg/L as CaCO3) to Daphnia magna was tested, both independently and in combination. Within these ranges, where no precipitation event occurred, shifts in water hardness and/or alkalinity were not toxic to D. magna. In contrast, 98-100% of D. magna died within 96h after exposure to 600mg/L as CaCO3 water hardness and 420mg/L as CaCO3 alkalinity (LT50 of 60h with a 95% CI of 54.2-66.0h). In this treatment, a CaCO3 (calcite) precipitate formed in the water column which was ingested by and thoroughly coated the D. magna. Calcite collected from a mining impacted stream contained embedded organisms, suggesting field streams may also experience similar conditions and possibly increased mortality as observed in the lab tests. Although further investigation is required to determine the exact fate of aquatic organisms exposed to rapid calcite precipitation in the field, we caution that negative effects may occur more quickly or at lower concentrations of water hardness and alkalinity in which we observed effects in D. magna, because some species, such as aquatic insects, are more sensitive than cladocerans to changes in ionic strength. Our results provide evidence that both calcite precipitation and the major ion balance of waters should be managed in industrially affected ecosystems and we support the development of a hardness+alkalinity guideline for the protection of aquatic life.

  20. Simulation of hydrogen sulphide absorption in alkaline solution using a packed column.

    PubMed

    Azizi, Mohamed; Biard, Pierre-François; Couvert, Annabelle; Ben Amor, Mohamed

    2014-01-01

    In this work, a simulation tool was developed for hydrogen sulphide (H₂S) removal in an alkaline solution in packed columns working at countercurrent. Modelling takes into account the mass-transfer enhancement due to the reversible reactions between H₂S and the alkaline species (CO(²⁻)(3), HCO⁻(3), and HO⁻) in the liquid film. Many parameters can be controlled by the user such as the gas and liquid inlet H₂S concentrations, the gas and liquid flow rates, the scrubbing liquid pH, the desired H₂S removal efficiency, the temperature, the alkalinity, etc. Since the influence of the hydrodynamic and mass-transfer performances in a packed column is well known, the numerical resolutions performed were dedicated to the study of the influence of the chemical conditions (through the pH and the alkalinity), the temperature and the liquid-to-gas mass flow rate ratio (L/G). A packed column of 3 m equipped with a given random packing material working at countercurrent and steady state has been modelled. The results show that the H₂S removal efficiency increases with the L/G, the pH, the alkalinity and more surprisingly with the temperature. Alkalinity has a very significant effect on the removal efficiency through the mass-transfer enhancement and buffering effect, which limits pH decreasing due to H₂S absorption. This numerical resolution provides a tool for designers and researchers involved in H₂S treatment to understand deeper the process and optimize their processes.

  1. Identification of a retroelement from the resurrection plant Boea hygrometrica that confers osmotic and alkaline tolerance in Arabidopsis thaliana.

    PubMed

    Zhao, Yan; Xu, Tao; Shen, Chun-Ying; Xu, Guang-Hui; Chen, Shi-Xuan; Song, Li-Zhen; Li, Mei-Jing; Wang, Li-Li; Zhu, Yan; Lv, Wei-Tao; Gong, Zhi-Zhong; Liu, Chun-Ming; Deng, Xin

    2014-01-01

    Functional genomic elements, including transposable elements, small RNAs and non-coding RNAs, are involved in regulation of gene expression in response to plant stress. To identify genomic elements that regulate dehydration and alkaline tolerance in Boea hygrometrica, a resurrection plant that inhabits drought and alkaline Karst areas, a genomic DNA library from B. hygrometrica was constructed and subsequently transformed into Arabidopsis using binary bacterial artificial chromosome (BIBAC) vectors. Transgenic lines were screened under osmotic and alkaline conditions, leading to the identification of Clone L1-4 that conferred osmotic and alkaline tolerance. Sequence analyses revealed that L1-4 contained a 49-kb retroelement fragment from B. hygrometrica, of which only a truncated sequence was present in L1-4 transgenic Arabidopsis plants. Additional subcloning revealed that activity resided in a 2-kb sequence, designated Osmotic and Alkaline Resistance 1 (OAR1). In addition, transgenic Arabidopsis lines carrying an OAR1-homologue also showed similar stress tolerance phenotypes. Physiological and molecular analyses demonstrated that OAR1-transgenic plants exhibited improved photochemical efficiency and membrane integrity and biomarker gene expression under both osmotic and alkaline stresses. Short transcripts that originated from OAR1 were increased under stress conditions in both B. hygrometrica and Arabidopsis carrying OAR1. The relative copy number of OAR1 was stable in transgenic Arabidopsis under stress but increased in B. hygrometrica. Taken together, our results indicated a potential role of OAR1 element in plant tolerance to osmotic and alkaline stresses, and verified the feasibility of the BIBAC transformation technique to identify functional genomic elements from physiological model species.

  2. Alkaline earth metal catalysts for asymmetric reactions.

    PubMed

    Kobayashi, Shū; Yamashita, Yasuhiro

    2011-01-18

    earth metal catalyst. We found that pyridinebisoxazolines (Pybox) worked well: they served as excellent ligands for calcium compounds in 1,4-addition reactions and Mannich reactions. Moreover, they were successful in 1,4-additions in concert with enantioselective protonation, affording the desired products in good to high enantioselectivities. Our results demonstrate that alkaline earth metals are very useful and attractive catalysts in organic synthesis. Moreover, their ubiquity in the environment is a distinct advantage over rare metals for large-scale processes, and their minimal toxicity is beneficial in both handling and disposal.

  3. Distinct stress conditions result in aggregation of proteins with similar properties

    PubMed Central

    Weids, Alan J.; Ibstedt, Sebastian; Tamás, Markus J.; Grant, Chris M.

    2016-01-01

    Protein aggregation is the abnormal association of proteins into larger aggregate structures which tend to be insoluble. This occurs during normal physiological conditions and in response to age or stress-induced protein misfolding and denaturation. In this present study we have defined the range of proteins that aggregate in yeast cells during normal growth and after exposure to stress conditions including an oxidative stress (hydrogen peroxide), a heavy metal stress (arsenite) and an amino acid analogue (azetidine-2-carboxylic acid). Our data indicate that these three stress conditions, which work by distinct mechanisms, promote the aggregation of similar types of proteins probably by lowering the threshold of protein aggregation. The proteins that aggregate during physiological conditions and stress share several features; however, stress conditions shift the criteria for protein aggregation propensity. This suggests that the proteins in aggregates are intrinsically aggregation-prone, rather than being proteins which are affected in a stress-specific manner. We additionally identified significant overlaps between stress aggregating yeast proteins and proteins that aggregate during ageing in yeast and C. elegans. We suggest that similar mechanisms may apply in disease- and non-disease settings and that the factors and components that control protein aggregation may be evolutionary conserved. PMID:27086931

  4. Distinct stress conditions result in aggregation of proteins with similar properties.

    PubMed

    Weids, Alan J; Ibstedt, Sebastian; Tamás, Markus J; Grant, Chris M

    2016-04-18

    Protein aggregation is the abnormal association of proteins into larger aggregate structures which tend to be insoluble. This occurs during normal physiological conditions and in response to age or stress-induced protein misfolding and denaturation. In this present study we have defined the range of proteins that aggregate in yeast cells during normal growth and after exposure to stress conditions including an oxidative stress (hydrogen peroxide), a heavy metal stress (arsenite) and an amino acid analogue (azetidine-2-carboxylic acid). Our data indicate that these three stress conditions, which work by distinct mechanisms, promote the aggregation of similar types of proteins probably by lowering the threshold of protein aggregation. The proteins that aggregate during physiological conditions and stress share several features; however, stress conditions shift the criteria for protein aggregation propensity. This suggests that the proteins in aggregates are intrinsically aggregation-prone, rather than being proteins which are affected in a stress-specific manner. We additionally identified significant overlaps between stress aggregating yeast proteins and proteins that aggregate during ageing in yeast and C. elegans. We suggest that similar mechanisms may apply in disease- and non-disease settings and that the factors and components that control protein aggregation may be evolutionary conserved.

  5. 40 CFR 420.110 - Applicability; description of the alkaline cleaning subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... alkaline cleaning subcategory. 420.110 Section 420.110 Protection of Environment ENVIRONMENTAL PROTECTION... Alkaline Cleaning Subcategory § 420.110 Applicability; description of the alkaline cleaning subcategory... publicly owned treatment works resulting from operations in which steel and steel products are immersed...

  6. 40 CFR 420.110 - Applicability; description of the alkaline cleaning subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... alkaline cleaning subcategory. 420.110 Section 420.110 Protection of Environment ENVIRONMENTAL PROTECTION... Alkaline Cleaning Subcategory § 420.110 Applicability; description of the alkaline cleaning subcategory... publicly owned treatment works resulting from operations in which steel and steel products are immersed...

  7. 40 CFR 420.110 - Applicability; description of the alkaline cleaning subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... alkaline cleaning subcategory. 420.110 Section 420.110 Protection of Environment ENVIRONMENTAL PROTECTION... Alkaline Cleaning Subcategory § 420.110 Applicability; description of the alkaline cleaning subcategory... publicly owned treatment works resulting from operations in which steel and steel products are immersed...

  8. 40 CFR 420.110 - Applicability; description of the alkaline cleaning subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... alkaline cleaning subcategory. 420.110 Section 420.110 Protection of Environment ENVIRONMENTAL PROTECTION... Alkaline Cleaning Subcategory § 420.110 Applicability; description of the alkaline cleaning subcategory... publicly owned treatment works resulting from operations in which steel and steel products are immersed...

  9. 40 CFR 420.110 - Applicability; description of the alkaline cleaning subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... alkaline cleaning subcategory. 420.110 Section 420.110 Protection of Environment ENVIRONMENTAL PROTECTION... Alkaline Cleaning Subcategory § 420.110 Applicability; description of the alkaline cleaning subcategory... publicly owned treatment works resulting from operations in which steel and steel products are immersed...

  10. Transpassive electrodissolution of depleted uranium in alkaline electrolytes

    SciTech Connect

    Weisbrod, K.R.; Schake, A.R.; Morgan, A.N.; Purdy, G.M.; Martinez, H.E.; Nelson, T.O.

    1998-03-01

    To aid in removal of oralloy from the nuclear weapons stockpile, scientists at the Los Alamos National Laboratory Plutonium Facility are decontaminating oralloy parts by electrodissolution in neutral to alkaline electrolytes composed of sodium nitrate and sodium sulfate. To improve the process, electrodissolution experiments were performed with depleted uranium to understand the effects of various operating parameters. Sufficient precipitate was also produced to evaluate the feasibility of using ultrafiltration to separate the uranium oxide precipitates from the electrolyte before it enters the decontamination fixture. In preparation for the experiments, a potential-pH diagram for uranium was constructed from thermodynamic data for fully hydrated species. Electrodissolution in unstirred solutions showed that uranium dissolution forms two layers, an acidic bottom layer rich in uranium and an alkaline upper layer. Under stirred conditions results are consistent with the formation of a yellow precipitate of composition UO{sub 3}{center_dot}2H{sub 2}O, a six electron process. Amperometric experiments showed that current efficiency remained near 100% over a wide range of electrolytes, electrolyte concentrations, pH, and stirring conditions.

  11. Results and Prospects of Studying the Gravitationally Sensitive Systems of Plants under Conditions of Space Flight

    NASA Astrophysics Data System (ADS)

    Mashinsky, A. L.; Nechitailo, G. S.

    2001-07-01

    Based on systematic studies of the impact of space flight factors on higher plants, carried out for many years both aboard orbital research stations and in the ground laboratories, we have formulated the means of solving the problem of the interaction of mankind with the plant life. The principal feasibility of the growth and development of higher plants (arabidopsis, peas, and wheat) under conditions of space flight is established, including the generative stage (arabidopsis). It is proved that the factors of space flight destabilize the macro- and microstructures of higher plants and their cellular organelles, which is an unambiguous response of cells to the changing conditions of their existence.

  12. Spectroscopic studies of alkaline activated slag geopolymers

    NASA Astrophysics Data System (ADS)

    Mozgawa, W.; Deja, J.

    2009-04-01

    In the work, results of structural studies of different geopolymers, obtained using a granulated blast furnace slag, are presented. The slag was subjected to an alkaline activation process. As activators, NaOH, Na 2CO 3 and liquid glass were applied. IR and NMR spectroscopy were the main experimental methods used, the results obtained were compared with XRD phase analysis and SEM observations. In the IR spectra of raw slag as well as in the spectra of products of paste hydration, the bands due to the characteristic vibrations of bonds observed in both types of oxygen bridges: Si-O-Si and Si-O-Al, were assigned. These bridges constitute basic structural units, forming tetrahedral geopolymer chains. It was found that the slag composition, mainly SiO 2/Al 2O 3 ratio and modification in oxides concentration, influences the presence of the bands connected with the phases (mainly C-S-H) formed during the hydration in the IR spectra. Additionally, significant effect of amorphous phases share on the spectra shape was established. 29Si and 27Al MAS-NMR spectra of initial slag geopolymers and pastes provided information concerning coordination of both atoms in the structures. It was revealed that the kind of slag geopolymers and the conditions of paste hydration influence connectedness of silicooxygen tetrahedra and coordination number of aluminium atoms. Based on IR spectra, it was also possible to determine the influence of the activator type, activation time and hydration conditions on the products formed. Significant changes were observed for the bands assigned to vibrations of carbonate and hydroxide groups. The changes were also noticed in the case of bands due to vibrations of silicate and aluminosilicate bonds.

  13. NALC/MEXICO LAND-COVER MAPPING RESULTS: IMPLICATIONS FOR ASSESSING LANDSCAPE CONDITION

    EPA Science Inventory

    An inventory of land-cover conditions throughout Mexico was performed using North American Landscap Characterization ( NALC) Landsat Multi-Spectral Scanner (MSS) 'triplicate' images, corresponding to the 1970s, 1980s and1990s epoch periods. The equivalent of 300 image scenes were...

  14. Preliminary Results from a Mesocosm Marsh Experiment with Treatments Simulating Three Tidal Flooding and Precipitation Conditions

    EPA Science Inventory

    Our goal was to observe and quantify the effects of low, medium and high tidal flooding regimes and various precipitation conditions on both Spartina alterniflora and Typha angustifolia in greenhouse mesocosms. The experiment was maintained for 4 months. Each of 3 tanks (600L) ha...

  15. NATIONAL RESULTS FROM THE 2011 NATIONAL WETLAND CONDITION ASSESSMENT (NWCA) SOILS ANALYSIS

    EPA Science Inventory

    In 2011, US Environmental Protection Agency conducted the first National Wetland Condition Assessment (NWCA). Field crews conducted one-day surveys of over 1000 wetlands across the contiguous United States. For every wetland sampled, soils were collected by layer (i.e., horizon)...

  16. Wooden breast condition results in reduced thaw loss in frozen-thawed broiler breast fillets

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wooden breast condition (WBC) is an emerging quality issue with broiler breast meat that significantly affects both raw and cooked meat properties. The objective of this study was to investigate the effects of WBC on meat water-holding capacity (WHC) estimated with different methods. Broiler breast ...

  17. Understanding of alkaline pretreatment parameters for corn stover enzymatic saccharification

    PubMed Central

    2013-01-01

    Background Previous research on alkaline pretreatment has mainly focused on optimization of the process parameters to improve substrate digestibility. To achieve satisfactory sugar yield, extremely high chemical loading and enzyme dosages were typically used. Relatively little attention has been paid to reduction of chemical consumption and process waste management, which has proven to be an indispensable component of the bio-refineries. To indicate alkali strength, both alkali concentration in pretreatment solution (g alkali/g pretreatment liquor or g alkali/L pretreatment liquor) and alkali loading based on biomass solids (g alkali/g dry biomass) have been widely used. The dual approaches make it difficult to compare the chemical consumption in different process scenarios while evaluating the cost effectiveness of this pretreatment technology. The current work addresses these issues through pretreatment of corn stover at various combinations of pretreatment conditions. Enzymatic hydrolysis with different enzyme blends was subsequently performed to identify the effects of pretreatment parameters on substrate digestibility as well as process operational and capital costs. Results The results showed that sodium hydroxide loading is the most dominant variable for enzymatic digestibility. To reach 70% glucan conversion while avoiding extensive degradation of hemicellulose, approximately 0.08 g NaOH/g corn stover was required. It was also concluded that alkali loading based on total solids (g NaOH/g dry biomass) governs the pretreatment efficiency. Supplementing cellulase with accessory enzymes such as α-arabinofuranosidase and β-xylosidase significantly improved the conversion of the hemicellulose by 6–17%. Conclusions The current work presents the impact of alkaline pretreatment parameters on the enzymatic hydrolysis of corn stover as well as the process operational and capital investment costs. The high chemical consumption for alkaline pretreatment technology

  18. Cation exchange properties of zeolites in hyper alkaline aqueous media.

    PubMed

    Van Tendeloo, Leen; de Blochouse, Benny; Dom, Dirk; Vancluysen, Jacqueline; Snellings, Ruben; Martens, Johan A; Kirschhock, Christine E A; Maes, André; Breynaert, Eric

    2015-02-03

    Construction of multibarrier concrete based waste disposal sites and management of alkaline mine drainage water requires cation exchangers combining excellent sorption properties with a high stability and predictable performance in hyper alkaline media. Though highly selective organic cation exchange resins have been developed for most pollutants, they can serve as a growth medium for bacterial proliferation, impairing their long-term stability and introducing unpredictable parameters into the evolution of the system. Zeolites represent a family of inorganic cation exchangers, which naturally occur in hyper alkaline conditions and cannot serve as an electron donor or carbon source for microbial proliferation. Despite their successful application as industrial cation exchangers under near neutral conditions, their performance in hyper alkaline, saline water remains highly undocumented. Using Cs(+) as a benchmark element, this study aims to assess the long-term cation exchange performance of zeolites in concrete derived aqueous solutions. Comparison of their exchange properties in alkaline media with data obtained in near neutral solutions demonstrated that the cation exchange selectivity remains unaffected by the increased hydroxyl concentration; the cation exchange capacity did however show an unexpected increase in hyper alkaline media.

  19. Nitrogen isotope evidence for alkaline lakes on late Archean continents

    NASA Astrophysics Data System (ADS)

    Stüeken, E. E.; Buick, R.; Schauer, A. J.

    2015-02-01

    Nitrogen isotope ratios in ancient sedimentary rocks are generally interpreted as a proxy for metabolic nitrogen pathways and the redox state of the water column. Fractionation processes occurring under anoxic, alkaline conditions during the dissociation of NH4+ to H+ and volatile NH3 are frequently overlooked, although this mechanism imparts large isotopic fractionations. Here we propose that NH3 volatilization is largely responsible for δ15N values of up to + 50 ‰ at high C/N ratios in the late Archean Tumbiana Formation. This sequence of sedimentary rocks represents a system of lakes that formed on subaerial flood basalts and were partly filled by basaltic volcanic ash. Aqueous alteration of volcanic glass followed by evaporative concentration of ions should have led to the development of high alkalinity with a pH of 9 or higher, as in modern analogues. In this sedimentologically unusual setting, nitrogen isotope ratios thus provide indirect evidence for the oldest alkaline lake system in the rock record. These very heavy lacustrine δ15N values contrast markedly with those of Archean marine sedimentary rocks, making a Precambrian "soda ocean" unlikely. Today, alkaline lakes are among the most productive ecosystems on Earth. Some nutrients, in particular molybdenum, are more soluble at high pH, and certain prebiotic reactions would likely have been favored under alkaline conditions in similar settings earlier in Earth's history. Hence alkaline lakes in the Archean could have been significant for the origin and early evolution of life.

  20. Limits for alkaline detoxification of dilute-acid lignocellulose hydrolysates.

    PubMed

    Nilvebrant, Nils-Olof; Persson, Per; Reimann, Anders; De Sousa, Filipe; Gorton, Lo; Jönsson, Leif J

    2003-01-01

    In addition to fermentable sugars, dilute-acid hydrolysates of lignocellulose contain compounds that inhibit fermenting microorganisms, such as Saccharomyces cerevisiae. Previous results show that phenolic compounds and furan aldehydes, and to some extent aliphatic acids, act as inhibitors during fermentation of dilute-acid hydrolysates of spruce. Treatment of lignocellulose hydrolysates with alkali, usually in the form of overliming to pH 10.0, has been frequently employed as a detoxification method to improve fermentability. A spruce dilute-acid hydrolysate was treated with NaOH in a factorial design experiment, in which the pH was varied between 9.0 and 12.0, the temperature between 5 and 80 degrees C, and the time between 1 and 7 h. Already at pH 9.0, >25% of the glucose was lost when the hydrolysate was treated at 80 degrees C for 1 h. Among the monosaccharides, xylose was degraded faster under alkaline conditions than the hexoses (glucose, mannose, and galactose), which, in turn, were degraded faster than arabinose. The results suggest that alkali treatment of hydrolysates can be performed at temperatures below 30 degrees C at any pH between 9.0 and 12.0 without problems with sugar degradation or formation of inhibiting aliphatic acids. Treatment with Ca(OH)2 instead of NaOH resulted in more substantial degradation of sugars. Under the harsher conditions of the factorial design experiment, the concentrations of furfural and 5-hydroxymethylfurfural decreased while the total phenolic content increased. The latter phenomenon was tentatively attributed to fragmentation of soluble aromatic oligomers in the hydrolysate. Separate phenolic compounds were affected in different ways by the alkaline conditions with some compounds showing an increase in concentration while others decreased. In conclusion, the conditions used for detoxification with alkali should be carefully controlled to optimize the positive effects and minimize the degradation of fermentable sugars.

  1. Critical rainfall conditions for the initiation of torrential flows. Results from the Rebaixader catchment (Central Pyrenees)

    NASA Astrophysics Data System (ADS)

    Abancó, Clàudia; Hürlimann, Marcel; Moya, José; Berenguer, Marc

    2016-10-01

    Torrential flows like debris flows or debris floods are fast movements formed by a mix of water and different amounts of unsorted solid material. They generally occur in steep torrents and pose high risk in mountainous areas. Rainfall is their most common triggering factor and the analysis of the critical rainfall conditions is a fundamental research task. Due to their wide use in warning systems, rainfall thresholds for the triggering of torrential flows are an important outcome of such analysis and are empirically derived using data from past events. In 2009, a monitoring system was installed in the Rebaixader catchment, Central Pyrenees (Spain). Since then, rainfall data of 25 torrential flows ("TRIG rainfalls") were recorded, with a 5-min sampling frequency. Other 142 rainfalls that did not trigger torrential flows ("NonTRIG rainfalls") were also collected and analyzed. The goal of this work was threefold: (i) characterize rainfall episodes in the Rebaixader catchment and compare rainfall data that triggered torrential flows and others that did not; (ii) define and test Intensity-Duration (ID) thresholds using rainfall data measured inside the catchment by with different techniques; (iii) analyze how the criterion used for defining the rainfall duration and the spatial variability of rainfall influences the value obtained for the thresholds. The statistical analysis of the rainfall characteristics showed that the parameters that discriminate better the TRIG and NonTRIG rainfalls are the rainfall intensities, the mean rainfall and the total rainfall amount. The antecedent rainfall was not significantly different between TRIG and NonTRIG rainfalls, as it can be expected when the source material is very pervious (a sandy glacial soil in the study site). Thresholds were derived from data collected at one rain gauge located inside the catchment. Two different methods were applied to calculate the duration and intensity of rainfall: (i) using total duration, Dtot

  2. Results of diurnal anisotropy in CR intensity on different geomagnetic conditions.

    NASA Astrophysics Data System (ADS)

    Dubey, S. K.; Kumar, S.; Agrawal, R.

    2001-08-01

    Cosmic Ray intensity data for a period of eleven years (1985-95; which covers descending phase of the 21st solar cycle and ascending phase of the 22nd solar cycle alongwith the maximum and minimum solar activity periods), have been analysed using four different criteria for selection of days for such analysis. Study of diurnal anisotropy on different criteria shows that the phase of diurnal anisotropy during 1985-91, remains constant within the statistical error limits and in the later period it shifts to early hours in 1992-93 and then it shifts further to earlier hours in 1994 and 95. It is also found that the characteristics of daily variation in cosmic ray intensity are quite comparable for all the four different groups of days, during the period of investigation. 1Introduction Association between the Cosmic Ray (CR) intensity and solar transients are well established and effects of changing interplanetary conditions in the interplanetary space are reflected in spatial distribution of CR intensity which also affect geomagnetic activity index Kp or Ap. The anisotropic modulation in CR intensity on long/short term basis has been studied for diurnal anisotropy and for higher harmonics in CR intensity, satisfying different criteria. Kumar et al (1981; 87; 93; 98) studied the diurnal anisotropy on geomagnetically quietestdays(60QD);Whereas,Rao(1972), Agrawal (1983); Bieber and Evanson (1997); Ahluwalia (1999) have opted All Days (AD) for such analysis. Agrawal (1981) considered to perform study over continuous periods, where the monthly mean values of diurnal amplitude and/or phase are significantly different as compared to the annual average values. This situation led to a search for the most suitable criteria for selection of days for analysis of CR intensity data. In the present paper, an attempt has been made to study the CR diurnal variation on the basis of different criteria. 2 Data Analysis Days with lowest values of Ap and Kp are identified as

  3. Color Perception in Microgravity Conditions: The Results of CROMOS Parabolic Flight Experiment

    NASA Astrophysics Data System (ADS)

    Schlacht, I. L.; Brambillasca, S.; Birke, H.

    2009-01-01

    The aims of this research are first to verify the actual difference in color perception between conditions in Earth's (1× g) and parabolic flight's microgravitational conditions (μg) and to improve the methodology used for data collection, testing the CROMOS software for color sensitivity investigation. Additionally this paper seeks to establish a larger awareness of microgravity vision and its design implications in the field of aerospace engineering. The analysis of variations in color perception between microgravity and 1× g can be applied to a range of fields concerning the space habitat (Fig. 1), the design of information (such as safety notices), or in the space station the analysis of chemical and biological reactions based on chromatography (for example, when subtle color variations are used as indicators in histological cell analysis).

  4. Effect of blood handling conditions on progesterone assay results obtained by chemiluminescence in the bitch.

    PubMed

    Tahir, M Z; Thoumire, S; Raffaelli, M; Grimard, B; Reynaud, K; Chastant-Maillard, S

    2013-10-01

    Assay of blood progesterone (P4) is commonly practiced to determine the time of ovulation, diagnose luteal insufficiency, and predict time of parturition in bitches. Because of practical constraints, most blood samples cannot be assayed on site immediately after collection. The aim of this work was to evaluate the effects of various sampling and storage conditions on concentrations of P4 as determined by chemiluminescence immunoassay. The blood of 5 Beagle bitches was collected from the jugular vein to study the effect of the type of collection tube (silicone, lithium heparin, EDTA), the storage time of unseparated or separated plasma (2 h to 14 d), and the number of freeze-thaw cycles (1-10) on P4. The effect of each factor was tested within one assay session. None of the factors significantly affected P4. Thus, P4 appears to remain relatively stable in canine blood samples exposed to various processing and storage conditions.

  5. Influence of housing conditions for mice on the results of a dermal oncogenicity bioassay.

    PubMed

    DePass, L R; Weil, C S; Ballantyne, B; Lewis, S C; Losco, P E; Reid, J B; Simon, G S

    1986-11-01

    Male C3H/HeJ mice were thrice weekly given 25 microliter applications of 0.25, 0.05, or 0.01% (w/w) benzo(a)pyrene (BaP) in acetone, or acetone alone, to clipped dorsal skin from 12 to 14 weeks of age for the remainder of their life spans. There were two groups of 40 mice for each treatment regimen, one group being housed in conventional stainless-steel wire mesh cages and the other in polycarbonate cages with wood shavings held in an enclosed ventilated cabinet. Under both housing conditions, tumor incidence was directly related and latency inversely related to BaP concentration. The time-adjusted incidence of epidermal neoplasms was significantly greater for the groups housed in polycarbonate cages. Mortality rates were directly related to BaP concentration and were significantly enhanced by the polycarbonate-cage housing conditions for the high and intermediate concentrations. Survival patterns for the two acetone control groups were similar. These findings indicate that differences in housing conditions can influence both the incidence and the latency of local neoplasms produced in response to the chronic application of a carcinogen in dermal oncogenesis bioassays.

  6. Role of mycorrhizal colonization in plant establishment on an alkaline gold mine tailing.

    PubMed

    Orłowska, Elzbieta; Orłowski, Dariusz; Mesjasz-Przybyłowicz, Jolanta; Turnau, Katarzyna

    2011-02-01

    The potential role of arbuscular mycorrhizal fungi (AMF) in the revegetation of an alkaline gold mine tailing was studied in Barberton, South Africa. The tailing, characterized by a slow spontaneous plant succession, is colonized by the shrub Dodonaea viscosa and the grasses, Andropogon eucomus and Imperata cylindrica, all colonized by AMF. The effectiveness of mycorrhizal colonization in grasses was tested under laboratory conditions using fungal isolates of various origins. Both grasses were highly mycorrhiza dependent, and the presence of mycorrhizal colonization significantly increased their biomass and survival rates. The fungi originating from the gold tailing were better adapted to the special conditions of the tailing than the control isolate. Although the total colonization rate found for native fungi was lower than for fungi from non-polluted sites, they were more vital and more effective in promoting plant growth. The results obtained might serve as a practical approach to the phytostabilization of alkaline gold tailings.

  7. Nature of immobilization surface affects antibody specificity to placental alkaline phosphatase.

    PubMed

    Kumar, Mukesh; Khan, Imran; Sinha, Subrata

    2015-01-01

    Retention of native conformation of immobilized protein is essential for various applications including selection and detection of specific recombinant antibodies (scFvs). Placental alkaline phosphatase (PAP), an onco-fetal antigen expressed on the surface of several tumors, was immobilized on supermagnetic particles for selection of recombinant antibodies from a human phage display antibody library. The isolated antibodies were found to be cross-reactive to either of the isozymes of alkaline phosphatase, i.e., bone alkaline phosphatase (BAP) or intestinal alkaline phosphatase (IAP) and could not be used for tumor targeting. A specific anti-PAP monoclonal antibody H17E2 was tested for retention of specificity under these conditions. Binding of the antibody to magnetic beads conjugated IAP and BAP along with PAP and the ability of the two isozymes to inhibit its binding to PAP depicted the loss of isozyme specificity of the antibody. However, the antibody retained its specificity to PAP immobilized on polyvinyl chloride (PVC) surface. Enzyme activity was observed on both surfaces. This demonstrates that nature of immobilization may affect antigen-antibody binding in subtle ways, resulting in alteration of conformation of the epitopes. This may have consequences for determining the specificity of antibody binding for proteins that share a high degree of homology.

  8. Braess's Paradox in Epidemic Game: Better Condition Results in Less Payoff

    PubMed Central

    Zhang, Hai-Feng; Yang, Zimo; Wu, Zhi-Xi; Wang, Bing-Hong; Zhou, Tao

    2013-01-01

    Facing the threats of infectious diseases, we take various actions to protect ourselves, but few studies considered an evolving system with competing strategies. In view of that, we propose an evolutionary epidemic model coupled with human behaviors, where individuals have three strategies: vaccination, self-protection and laissez faire, and could adjust their strategies according to their neighbors' strategies and payoffs at the beginning of each new season of epidemic spreading. We found a counter-intuitive phenomenon analogous to the well-known Braess's Paradox, namely a better condition may lead to worse performance. Specifically speaking, increasing the successful rate of self-protection does not necessarily reduce the epidemic size or improve the system payoff. The range and degree of the Braess's Paradox are sensitive to both the parameters characterizing the epidemic spreading and the strategy payoff, while the existence of the Braess's Paradox is insensitive to the network topologies. This phenomenon can be well explained by a mean-field approximation. Our study demonstrates an important fact that a better condition for individuals may yield a worse outcome for the society. PMID:24256996

  9. Identification of a major QTL allele from wild soybean (Glycine soja Sieb. & Zucc.) for increasing alkaline salt tolerance in soybean.

    PubMed

    Tuyen, D D; Lal, S K; Xu, D H

    2010-07-01

    Salt-affected soils are generally classified into two main categories, sodic (alkaline) and saline. Our previous studies showed that the wild soybean accession JWS156-1 (Glycine soja) from the Kinki area of Japan was tolerant to NaCl salt, and the quantitative trait locus (QTL) for NaCl salt tolerance was located on soybean linkage group N (chromosome 3). Further investigation revealed that the wild soybean accession JWS156-1 also had a higher tolerance to alkaline salt stress. In the present study, an F(6) recombinant inbred line mapping population (n = 112) and an F(2) population (n = 149) derived from crosses between a cultivated soybean cultivar Jackson and JWS156-1 were used to identify QTL for alkaline salt tolerance in soybean. Evaluation of soybean alkaline salt tolerance was carried out based on salt tolerance rating (STR) and leaf chlorophyll content (SPAD value) after treatment with 180 mM NaHCO(3) for about 3 weeks under greenhouse conditions. In both populations, a significant QTL for alkaline salt tolerance was detected on the molecular linkage group D2 (chromosome 17), which accounted for 50.2 and 13.0% of the total variation for STR in the F(6) and the F(2) populations, respectively. The wild soybean contributed to the tolerance allele in the progenies. Our results suggest that QTL for alkaline salt tolerance is different from the QTL for NaCl salt tolerance found previously in this wild soybean genotype. The DNA markers closely associated with the QTLs might be useful for marker-assisted selection to pyramid tolerance genes in soybean for both alkaline and saline stresses.

  10. Net alkalinity and net acidity 2: Practical considerations

    USGS Publications Warehouse

    Kirby, C.S.; Cravotta, C.A.

    2005-01-01

    The pH, alkalinity, and acidity of mine drainage and associated waters can be misinterpreted because of the chemical instability of samples and possible misunderstandings of standard analytical method results. Synthetic and field samples of mine drainage having various initial pH values and concentrations of dissolved metals and alkalinity were titrated by several methods, and the results were compared to alkalinity and acidity calculated based on dissolved solutes. The pH, alkalinity, and acidity were compared between fresh, unoxidized and aged, oxidized samples. Data for Pennsylvania coal mine drainage indicates that the pH of fresh samples was predominantly acidic (pH 2.5-4) or near neutral (pH 6-7); ??? 25% of the samples had pH values between 5 and 6. Following oxidation, no samples had pH values between 5 and 6. The Standard Method Alkalinity titration is constrained to yield values >0. Most calculated and measured alkalinities for samples with positive alkalinities were in close agreement. However, for low-pH samples, the calculated alkalinity can be negative due to negative contributions by dissolved metals that may oxidize and hydrolyze. The Standard Method hot peroxide treatment titration for acidity determination (Hot Acidity) accurately indicates the potential for pH to decrease to acidic values after complete degassing of CO2 and oxidation of Fe and Mn, and it indicates either the excess alkalinity or that required for neutralization of the sample. The Hot Acidity directly measures net acidity (= -net alkalinity). Samples that had near-neutral pH after oxidation had negative Hot Acidity; samples that had pH < 6.3 after oxidation had positive Hot Acidity. Samples with similar pH values before oxidation had dissimilar Hot Acidities due to variations in their alkalinities and dissolved Fe, Mn, and Al concentrations. Hot Acidity was approximately equal to net acidity calculated based on initial pH and dissolved concentrations of Fe, Mn, and Al minus the

  11. Metabolic flux analyses for serine alkaline protease production.

    PubMed

    Çalik; Çalik; Takaç; Özdamar

    2000-12-01

    The intracellular metabolic fluxes through the central carbon pathways in Bacillus licheniformis in serine alkaline protease (SAP) production were calculated to predict the potential strategies for increasing the performance of the bacilli, by using two optimization approaches, i.e. the theoretical data-based (TDA) and the theoretical data-based capacity (TDC) analyses based on respectively minimum in-vivo SAP accumulation rate and maximum SAP synthesis rate assumptions, at low-, medium-, and high-oxygen transfer conditions. At all periods of low-oxygen transfer condition, in lag and early exponential periods of medium-oxygen transfer (MOT) condition, and SAP synthesis period of high-oxygen transfer (HOT) condition, the TDA and TDC analyses revealed that SAP overproduction capacity is almost equal to the observed SAP production due to the regulation effect of the oxygen transfer. In the growth and early SAP synthesis period and in SAP synthesis period at MOT condition the calculated results of the two analyses reveal that SAP synthesis rate of the microorganism can be increased 7.2 and 16.7 folds, respectively; whereas, in the growth and early SAP synthesis period at HOT condition it can be increased 12.6 folds. The diversions in the biochemical reaction network and the influence of the oxygen transfer on the performance of the bacilli were also presented. The results encourage the application of metabolic engineering for lifting the rate limitations and for improving the genetic regulations in order to increase the SAP production.

  12. Department of Defense Survey of Living Conditions Overseas. 1984. Volume 2. Results.

    DTIC Science & Technology

    1985-07-01

    8 8.7 14 Vehicles (shipping, insurance, inspection) 14.7 9 23.0 5 Recreation and entertainment 14.1 10 8.9 13 Family adjustment to the new situation...housing, working conditions, and transportation and least concerned with recreation and entertainment , shopping, medical/dental care, and vehicles...Economy 35.3 52.3 14.7 16.1 20.7 26.0 Half and half 28.2 24.5 24.7 27.6 25.7 26.8 Government 36.6 23.1 60.6 56.3 53.6 47.2 , Q95. Entertainment (theatres

  13. Overexpression of Human Bone Alkaline Phosphatase in Pichia Pastoris

    NASA Technical Reports Server (NTRS)

    Karr, Laurel; Malone, Christine, C.; Rose, M. Franklin (Technical Monitor)

    2000-01-01

    The Pichiapastoris expression system was utilized to produce functionally active human bone alkaline phosphatase in gram quantities. Bone alkaline phosphatase is a key enzyme in bone formation and biomineralization, yet important questions about its structural chemistry and interactions with other cellular enzymes in mineralizing tissues remain unanswered. A soluble form of human bone alkaline phosphatase was constructed by deletion of the 25 amino acid hydrophobic C-terminal region of the encoding cDNA and inserted into the X-33 Pichiapastoris strain. An overexpression system was developed in shake flasks and converted to large-scale fermentation. Alkaline phosphatase was secreted into the medium to a level of 32mgAL when cultured in shake flasks. Enzyme activity was 12U/mg measured by a spectrophotometric assay. Fermentation yielded 880mgAL with enzymatic activity of 968U/mg. Gel electrophoresis analysis indicates that greater than 50% of the total protein in the fermentation is alkaline phosphatase. A purification scheme has been developed using ammonium sulfate precipitation followed by hydrophobic interaction chromatography. We are currently screening crystallization conditions of the purified recombinant protein for subsequent X-ray diffraction analyses. Structural data should provide additional information on the role of alkaline phosphatase in normal bone mineralization and in certain bone mineralization anomalies.

  14. Results of thermal performance evaluation of the Owens-Illinois sunpack liquid solar collector at indoor conditions

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Test procedures and results of the thermal performance of a liquid, evacuated tube, solar collector under simulated conditions are presented. The collector tested was a module used on the early demonstration projects.

  15. Results.

    ERIC Educational Resources Information Center

    Zemsky, Robert; Shaman, Susan; Shapiro, Daniel B.

    2001-01-01

    Describes the Collegiate Results Instrument (CRI), which measures a range of collegiate outcomes for alumni 6 years after graduation. The CRI was designed to target alumni from institutions across market segments and assess their values, abilities, work skills, occupations, and pursuit of lifelong learning. (EV)

  16. Long working hours in Korea: results of the 2010 Working Conditions Survey.

    PubMed

    Park, Jungsun; Kwon, Oh Jun; Kim, Yangho

    2012-01-01

    Long working hours adversely affect workers' safety and health. In 2004, Korea passed legislation limiting the working week to 40 h, to improve quality-of-life and to increase business competitiveness. In the present study, we explored the characteristics of work in Korea and compared our data of the second Korean Working Conditions Survey (KWCS) with those of the first KWCS. We found that the average number of hours worked weekly has been reduced but the proportions of workers who work for more than 48 h per week has increased over the 4 yr between the two Korean surveys in all categories studied (male, female, employee, self-employed, and employer). We also found that self-employed and employers work much longer hours than do employees, who are protected by the Labor Standards Act. This was particularly true in the accommodation and food service sectors. In conclusion, Korean workers work longer than do workers of EU countries. The use of average figures masks differences in the numbers of working hours among those engaged in various types of employment, or in certain work sectors. Therefore, the Korean government should not simply monitor reductions in average weekly working hours, but should identify employees working for over 60 h weekly, and reduce their working time.

  17. Neuroplastic reactivity of fish induced by altered gravity conditions: a review of recent results

    NASA Astrophysics Data System (ADS)

    Rahmann, H.; Anken, R. H.

    A review is being presented concerning behavioural, biochemical, histochemical and electronmicroscopical data on the influence of altered gravitational forces on the swimming performance and on the neuronal differentiation of the brain of cichlid fish larvae and adult swordtail fish that had been exposed to hyper-gravity (3g in laboratory centrifuges), hypo-gravity (>10^-2g in a fast-rotating clinostat) and to near weightlessness (10^-4g aboard the spacelab D-2 mission). After long-term alterations of gravity (and parallel light deprivation), initial disturbances in the swimming behaviour followed by a stepwise regain of normal swimming modes are induced. Parallely, neuroplastic reactivities on different levels of investigation were found, such as adaptive alterations of activities of various enzymes in whole brain as well as in specific neuronal integration centers and an intraneuronal reactivity on ultrastructural level in individual brain parts and in the sensory epithelia of the inner ear. Taken together, these data reveal distinct adaptive neuroplastic reactions of fish to altered gravity conditions.

  18. New Results in Two-Phase Pressure Drop Calculations at Reduced Gravity Conditions

    NASA Astrophysics Data System (ADS)

    Braisted, Jon; Kurwitz, Cable; Best, Frederick

    2004-02-01

    The mass, power, and volume energy savings of two-phase systems for future spacecraft creates many advantages over current single-phase systems. Current models of two-phase phenomena such as pressure drop, void fraction, and flow regime prediction are still not well defined for space applications. Commercially available two-phase modeling software has been developed for a large range of acceleration fields including reduced-gravity conditions. Recently, a two-phase experiment has been flown to expand the two-phase database. A model of the experiment was created in the software to determine how well the software could predict the pressure drop observed in the experiment. Of the simulations conducted, the computer model shows good agreement of the pressure drop in the experiment to within 30%. However, the software does begin to over-predict pressure drop in certain regions of a flow regime map indicating that some models used in the software package for reduced-gravity modeling need improvement.

  19. High-risk biodegradable waste processing by alkaline hydrolysis.

    PubMed

    Kalambura, Sanja; Voća, Neven; Krička, Tajana; Sindrak, Zoran; Spehar, Ana; Kalambura, Dejan

    2011-09-01

    Biodegradable waste is by definition degraded by other living organisms. Every day, meat industry produces large amounts of a specific type of biodegradable waste called slaughterhouse waste. Traditionally in Europe, this waste is recycled in rendering plants which produce meat and bone meal and fat. However, feeding animals with meat and bone meal has been banned since the outbreaks of bovine spongiform encephalopathy (BSE). In consequence, new slaughterhouse waste processing technologies have been developed, and animal wastes have now been used for energy production. Certain parts of this waste, such as brains and spinal cord, are deemed high-risk substances, because they may be infected with prions. Their treatment is therefore possible only in strictly controlled conditions. One of the methods which seems to bear acceptable health risk is alkaline hydrolysis. This paper presents the results of an alkaline hydrolysis efficiency study. It also proposes reuse of the obtained material as organic fertiliser, as is suggested by the analytical comparison between meat and bone meal and hydrolysate.

  20. Improving the alkaline stability of imidazolium cations by substitution.

    PubMed

    Dong, Huilong; Gu, Fenglou; Li, Min; Lin, Bencai; Si, Zhihong; Hou, Tingjun; Yan, Feng; Lee, Shuit-Tong; Li, Youyong

    2014-10-06

    Imidazolium cations are promising candidates for preparing anion-exchange membranes because of their good alkaline stability. Substitution of imidazolium cations is an efficient way to improve their alkaline stability. By combining density functional theory calculations with experimental results, it is found that the LUMO energy correlates with the alkaline stability of imidazolium cations. The results indicate that alkyl groups are the most suitable substituents for the N3 position of imidazolium cations, and the LUMO energies of alkyl-substituted imidazolium cations depend on the electron-donating effect and the hyperconjugation effect. Comparing 1,2-dimethylimidazolium cations (1,2-DMIm+) and 1,3-dimethylimidazolium cations (1,3-DMIm+) with the same substituents reveals that the hyperconjugation effect is more significant in influencing the LUMO energy of 1,3-DMIms. This investigation reveals that LUMO energy is a helpful aid in predicting the alkaline stability of imidazolium cations.

  1. Net alkalinity and net acidity 1: Theoretical considerations

    USGS Publications Warehouse

    Kirby, C.S.; Cravotta, C.A.

    2005-01-01

    Net acidity and net alkalinity are widely used, poorly defined, and commonly misunderstood parameters for the characterization of mine drainage. The authors explain theoretical expressions of 3 types of alkalinity (caustic, phenolphthalein, and total) and acidity (mineral, CO2, and total). Except for rarely-invoked negative alkalinity, theoretically defined total alkalinity is closely analogous to measured alkalinity and presents few practical interpretation problems. Theoretically defined "CO 2-acidity" is closely related to most standard titration methods with an endpoint pH of 8.3 used for determining acidity in mine drainage, but it is unfortunately named because CO2 is intentionally driven off during titration of mine-drainage samples. Using the proton condition/mass- action approach and employing graphs to illustrate speciation with changes in pH, the authors explore the concept of principal components and how to assign acidity contributions to aqueous species commonly present in mine drainage. Acidity is defined in mine drainage based on aqueous speciation at the sample pH and on the capacity of these species to undergo hydrolysis to pH 8.3. Application of this definition shows that the computed acidity in mg L -1 as CaCO3 (based on pH and analytical concentrations of dissolved FeII, FeIII, Mn, and Al in mg L -1):aciditycalculated=50{1000(10-pH)+[2(FeII)+3(FeIII)]/56+2(Mn)/ 55+3(Al)/27}underestimates contributions from HSO4- and H+, but overestimates the acidity due to Fe3+ and Al3+. However, these errors tend to approximately cancel each other. It is demonstrated that "net alkalinity" is a valid mathematical construction based on theoretical definitions of alkalinity and acidity. Further, it is shown that, for most mine-drainage solutions, a useful net alkalinity value can be derived from: (1) alkalinity and acidity values based on aqueous speciation, (2) measured alkalinity minus calculated acidity, or (3) taking the negative of the value obtained in a

  2. PRELIMINARY RESULTS: RELEASE OF METALS FROM ACID-MINE DRAINAGE CONTAMINATED STREAMBED SEDIMENTS UNDER ANOXIC CONDITIONS

    EPA Science Inventory

    Many miles of streams are contaminated with acid-mine drainage (AMD) from abandoned metal mines in the western U.S. Treatment of these streams may include dredging of the existing sediments, with subsequent burial. Burial of previously toxic sediments may result in release of met...

  3. Forecast of long term coal supply and mining conditions: Model documentation and results

    NASA Technical Reports Server (NTRS)

    1980-01-01

    A coal industry model was developed to support the Jet Propulsion Laboratory in its investigation of advanced underground coal extraction systems. The model documentation includes the programming for the coal mining cost models and an accompanying users' manual, and a guide to reading model output. The methodology used in assembling the transportation, demand, and coal reserve components of the model are also described. Results presented for 1986 and 2000, include projections of coal production patterns and marginal prices, differentiated by coal sulfur content.

  4. Electron Attachment to SF(6) Under Well Defined Conditions: Comparison of Statistical Modeling Results to Experiments

    DTIC Science & Technology

    2007-08-01

    Avogadro constant , EA is the electron affinity (at 0 K, by definition), AS" is the entropy change due to electron attachment at temperature T, and...measure rate constants for electron attachment to SF6 and thermal detachment from SF6’. In a recent series of papers, these results were combined...hexafluoride Statistical theory Rate constants 16. SECURITY CLASSIFICATION OF: a. REPORT UNCL b. ABSTRACT UNCL c. THIS PAGE UNCL 17. LIMITATION OF

  5. Influence of mesophase activation conditions on the specific capacitance of the resulting carbons

    NASA Astrophysics Data System (ADS)

    Mora, E.; Ruiz, V.; Santamaría, R.; Blanco, C.; Granda, M.; Menéndez, R.; Juarez-Galán, J. M.; Rodríguez-Reinoso, F.

    Mesophase pitch AR24 was directly activated with KOH using different proportions of the activating agent and activation temperatures, to study the effect on the textural characteristics of the resultant activated carbons and how these characteristics influence their behaviour as electrodes in supercapacitors. The textural properties of the activated carbons were studied by gas adsorption and immersion calorimetry. The results indicate that all the carbons produced were mainly microporous, with pore size around 1 nm. The behaviour of these carbons as electrodes in supercapacitors was studied from galvanostatic charge-discharge cycles. The specific capacitance values obtained were very high, reaching 400 and 200 F g -1 at low and high current densities respectively, for the sample activated with (5:1) KOH to mesophase ratio. Nevertheless, the reasons for this high capacitance values cannot be explained only on the basis of the textural characteristics of the activated carbons, as the results indicated that other factors might be also playing a significant role in their electrochemical behaviour.

  6. AG Channel Measurement and Modeling Results for Over-Sea Conditions

    NASA Technical Reports Server (NTRS)

    Matolak, David; Sun, Rouyu

    2014-01-01

    This report describes results from flight tests conducted in an over-sea environment, for the purpose of characterizing the air-to-ground (AG) channel, for future unmanned aircraft system (UAS) communication system analysis and design. These results are for the first of a set of several flight tests conducted in different ground site (GS) environments. An ultimate aim of all these tests is the development of models for the AG channel that can be used in communication system evaluation. In this report we provide measured results for propagation path loss, root-mean square delay spread (RMS-DS), and the correlation coefficient of the primary received signal components on the four antennas (two antennas for C-band, two for L-band). For path loss, the curved-earth two-ray model provides a reasonable fit to the measured data, altered by several dB at the shortest link distances by aircraft antenna pattern effects. This two-ray model also accounts for the majority of measured RMS-DS results of a few tens of nanoseconds, except for the occasional intermittent reflections from surface objects. These intermittent reflections yield RMS-DS values up to several hundred nanoseconds. For portions of the flight path that were over a harbor area highly populated with boats, the channel was found to be more "continuously dispersive," with RMS-DS reaching approximately 250 ns. A separate model will be developed for this over-harbor setting. The correlation coefficient results are still undergoing analysis; preliminary observations are that correlation between signals on the same-band antennas is generally large (>0.6) for the C-band straight flight paths, whereas for the L-band signals and for the oval-shaped flight paths the correlation is generally small (below 0.4). Inter-band correlations are typically very small, and are well modeled as zero-mean Gaussian in distribution, with a standard deviation less than 0.2. Hence the over-sea channel effects in the two bands can be

  7. LLNL heart valve condition classification project anechoic testing results at the TRANSDEC evaluation facility

    SciTech Connect

    Candy, J V

    1999-10-31

    This report first briefly outlines the procedures and support/activation fixture developed at LLNL to perform the heart valve tests in an anechoic-like tank at the US Navy Transducer Evaluation Facility (TransDec) located in San Diego, CA. Next they discuss the basic experiments performed and the corresponding experimental plan employed to gather meaningful data systematically. The signal processing required to extract the desired information is briefly developed along with some of the data. Finally, they show the results of the individual runs for each valve, point out any of the meaningful features and summaries.

  8. Alkaline stability of quaternary ammonium cations for alkaline fuel cell membranes and ionic liquids.

    PubMed

    Marino, M G; Kreuer, K D

    2015-02-01

    The alkaline stability of 26 different quaternary ammonium groups (QA) is investigated for temperatures up to 160 °C and NaOH concentrations up to 10 mol L(-1) with the aim to provide a basis for the selection of functional groups for hydroxide exchange membranes in alkaline fuel cells and of ionic-liquid cations stable in basic conditions. Most QAs exhibit unexpectedly high alkaline stability with the exception of aromatic cations. β-Protons are found to be far less susceptible to nucleophilic attack than previously suggested, whereas the presence of benzyl groups, nearby hetero-atoms, or other electron-withdrawing species promote degradation reactions significantly. Cyclic QAs proved to be exceptionally stable, with the piperidine-based 6-azonia-spiro[5.5]undecane featuring the highest half-life at the chosen conditions. Absolute and relative stabilities presented herein stand in contrast to literature data, the differences being ascribed to solvent effects on degradation.

  9. AG Channel Measurement and Modeling Results for Over-Water and Hilly Terrain Conditions

    NASA Technical Reports Server (NTRS)

    Matolak, David W.; Sun, Ruoyu

    2015-01-01

    This report describes work completed over the past year on our project, entitled "Unmanned Aircraft Systems (UAS) Research: The AG Channel, Robust Waveforms, and Aeronautical Network Simulations." This project is funded under the NASA project "Unmanned Aircraft Systems (UAS) in the National Airspace System (NAS)." In this report we provide the following: an update on project progress; a description of the over-freshwater and hilly terrain initial results on path loss, delay spread, small-scale fading, and correlations; complete path loss models for the over-water AG channels; analysis for obtaining parameter statistics required for development of accurate wideband AG channel models; and analysis of an atypical AG channel in which the aircraft flies out of the ground site antenna main beam. We have modeled the small-scale fading of these channels with Ricean statistics, and have quantified the behavior of the Ricean K-factor. We also provide some results for correlations of signal components, both intra-band and inter-band. An updated literature review, and a summary that also describes future work, are also included.

  10. Transgenic petunia with the iron(III)-phytosiderophore transporter gene acquires tolerance to iron deficiency in alkaline environments.

    PubMed

    Murata, Yoshiko; Itoh, Yoshiyuki; Iwashita, Takashi; Namba, Kosuke

    2015-01-01

    Iron is an essential nutrient for all plants. However, terrestrial plants often suffer from iron deficiency in alkaline soil due to its extremely low solubility. Alkaline soil accounts for about 30% of all cultivated ground in the world. Plants have evolved two distinct strategies, I and II, for iron uptake from the soil. Dicots and non-graminaceous monocots use Strategy I, which is primarily based on the reduction of iron(III) to iron(II) and the uptake of iron(II) by the iron-regulated transporter, IRT1. In contrast, graminaceous plants use Strategy II to efficiently acquire insoluble iron(III). Strategy II comprises the synthesis and secretion of iron-chelating phytosiderophores, such as mugineic acids and the Yellow Stripe 1 transporter proteins of the iron(III)-phytosiderophore complex. Barley, which exhibits the highest tolerance to iron deficiency in alkaline soil among graminaceous plants, utilizes mugineic acids and the specific iron(III)-mugineic acids transporter, HvYS1. In this study, we established the transgenic plant Petunia hybrida, which originally had only Strategy I, by introducing the HvYS1 transporter gene derived from barley. When the transgenic plants were grown hydroponically in media containing the iron(III)-2'-deoxymugineic acid complex, free 2'-deoxymugineic acid and its iron(III) complex were detected in the root extract of the transgenic plant by electrospray ionization-Fourier transform-ion cyclotron resonance mass spectrometry. The growth of the transgenic petunia was significantly better than that of the control host in alkaline conditions. Consequently, the transgenic plant acquired a significantly enhanced tolerance to alkaline hydroponic media in the presence of the iron(III)-2'-deoxymugineic acid complex. Furthermore, the flower color of the transgenic plant deepened. The results showed that iron-phytosiderophore complexes and their transporters can potentially be utilized to overcome the worldwide iron uptake problems to diverse

  11. A Constructed Alkaline Consortium and Its Dynamics in Treating Alkaline Black Liquor with Very High Pollution Load

    PubMed Central

    Yang, Chunyu; Cao, Guangchun; Li, Yang; Zhang, Xiaojun; Ren, Hongyan; Wang, Xia; Feng, Jinhui; Zhao, Liping; Xu, Ping

    2008-01-01

    Background Paper pulp wastewater resulting from alkaline extraction of wheat straw, known as black liquor, is very difficult to be treated and causes serious environmental problems due to its high pH value and chemical oxygen demand (COD) pollution load. Lignin, semicellulose and cellulose are the main contributors to the high COD values in black liquor. Very few microorganisms can survive in such harsh environments of the alkaline wheat straw black liquor. A naturally developed microbial community was found accidentally in a black liquor storing pool in a paper pulp mill of China. The community was effective in pH decreasing, color and COD removing from the high alkaline and high COD black liquor. Findings Thirty-eight strains of bacteria were isolated from the black liquor storing pool, and were grouped as eleven operational taxonomy units (OTUs) using random amplified polymorphic DNA-PCR profiles (RAPD). Eleven representative strains of each OTU, which were identified as genera of Halomonas and Bacillus, were used to construct a consortium to treat black liquor with a high pH value of 11.0 and very high COD pollution load of 142,600 mg l−1. After treatment by the constructed consortium, about 35.4% of color and 39,000 mg l−1 (27.3%) CODcr were removed and the pH decreased to 7.8. 16S rRNA gene polymerase chain reaction denaturant gradient gel electrophoresis (PCR-DGGE) and gas chromatography/mass spectrometry (GC/MS) analysis suggested a two-stage treatment mechanism to elucidate the interspecies collaboration: Halomonas isolates were important in the first stage to produce organic acids that contributed to the pH decline, while Bacillus isolates were involved in the degradation of lignin derivatives in the second stage under lower pH conditions. Conclusions/Significance Tolerance to the high alkaline environment and good controllability of the simple consortium suggested that the constructed consortium has good potential for black liquor treatment

  12. Electrical resistivity measurements of brine saturated porous media near reservoir conditions: Awibengkok preliminary results

    SciTech Connect

    Bonner, B; Duba, A; Roberts, J

    1999-06-28

    Laboratory measurements of the electrical resistivity of rocks and synthetic rocks with confining pressures up to 100 bars and temperatures between 20 and 211 C were performed to further investigate how the pore-size distribution and capillarity affects boiling in porous media. Similar to previous measurements on samples from The Geysers, CA, we observed a gradual increase in resistivity when pore pressure was decreased below the phase-boundary pressure of free water, an indication that boiling is controlled not only by temperature and pressure, but also by pore size distribution. Other important phenomena observed were strong resistance fluctuations during boiling that may be chaotic, and salt deposition that caused sample cracking. If confirmed in further experiments, these results may lead to a new geophysical diagnostic for locating boiling in high permeability areas of geothermal reservoirs and for methods of permeability alteration.

  13. Regulation of alkaline phosphatase expression in human choriocarcinoma cell lines.

    PubMed Central

    Hamilton, T A; Tin, A W; Sussman, H H

    1979-01-01

    The coincident expression of two structurally distinct isoenzymes of human alkaline phosphatase was demonstrated in two independently derived gestational choriocarcinoma cell lines. These proteins were shown to have enzymatic, antigenic, and physical-chemical properties resembling those of isoenzymes from term placenta and adult liver. The regulation of these isoenzymes has been studied during the exposure of both cell lines to 5-bromodeoxyuridine and dibutyryl cyclic AMP. The responses of the alkaline phosphatase isoenzymes to these agents have also been compared with the response of another protein phenotypic to placenta, the alpha subunit of chorionic gonadotropin. The results show that (i) the separate structural genes coding for placental and liver alkaline phosphatases are regulated in a noncoordinate fashion; (ii) both alkaline phosphatase genes respond independently of the alpha subunit; and (iii) the induction of the placental type isoenzyme occurs via at least two independent pathways. Images PMID:218197

  14. Conditional abrogation of Atm in osteoclasts extends osteoclast lifespan and results in reduced bone mass

    PubMed Central

    Hirozane, Toru; Tohmonda, Takahide; Yoda, Masaki; Shimoda, Masayuki; Kanai, Yae; Matsumoto, Morio; Morioka, Hideo; Nakamura, Masaya; Horiuchi, Keisuke

    2016-01-01

    Ataxia-telangiectasia mutated (ATM) kinase is a central component involved in the signal transduction of the DNA damage response (DDR) and thus plays a critical role in the maintenance of genomic integrity. Although the primary functions of ATM are associated with the DDR, emerging data suggest that ATM has many additional roles that are not directly related to the DDR, including the regulation of oxidative stress signaling, insulin sensitivity, mitochondrial homeostasis, and lymphocyte development. Patients and mice lacking ATM exhibit growth retardation and lower bone mass; however, the mechanisms underlying the skeletal defects are not fully understood. In the present study, we generated mutant mice in which ATM is specifically inactivated in osteoclasts. The mutant mice did not exhibit apparent developmental defects but showed reduced bone mass due to increased osteoclastic bone resorption. Osteoclasts lacking ATM were more resistant to apoptosis and showed a prolonged lifespan compared to the controls. Notably, the inactivation of ATM in osteoclasts resulted in enhanced NF-κB signaling and an increase in the expression of NF-κB-targeted genes. The present study reveals a novel function for ATM in regulating bone metabolism by suppressing the lifespan of osteoclasts and osteoclast-mediated bone resorption. PMID:27677594

  15. Electron attachment to SF6 under well defined conditions: comparison of statistical modeling results to experiments

    NASA Astrophysics Data System (ADS)

    Miller, T. M.; Viggiano, A. A.; Troe, J.

    2008-05-01

    Experiments were carried out using a flowing-afterglow Langmuir-probe apparatus to measure rate constants for electron attachment to SF6 and thermal detachment from SF6-. In a recent series of papers, these results were combined with new and existing data on nondissociative and dissociative attachment to SF6 and compared to statistical modeling of the various processes involved in the stabilization of the ionic products of attachment. This paper gives a summary of those findings. The major conclusions are: (a) only the ground electronic state of SF6- needs to be invoked to explain available data; (b) the electron affinity of SF6 is higher than previously thought, namely, EA(SF6) = 1.20 (± 0.05) eV; (c) the endothermicity of the dissociative electron attachment reaction that yields SF5- is 0.41 eV (± 0.05) eV at 0 K; (d) combining these two numbers gives the bond energy D0o(F—SF5-) = 1.61 (± 0.05) eV.

  16. Condition Assessment of PCI Bridge Girder a Result of The Reduction Prestressing Force

    NASA Astrophysics Data System (ADS)

    Suangga, Made; Hidayat, Irpan; Lutter, Bobby

    2014-03-01

    PCI bridge girders is known and widely used for many construction e.g.: bridge, wharf, flyover, and other application. PC Bridge girders have two types: Pre - tensioned girders and post - tensioned girders. In pre tensioned girders, prestressing in carried out first then after that the fresh concrete poured. The prestressing process in only carried off after the concrete has sufficient strength. In this study, analysis was conducted for PCI bridge girder with span is 40 meters. Based on the data geometry bridge dimension girder, material girder, and material strands cable, it will be analyzed to calculate the natural frequencies and moment capacity using finite element program (Midas/Civil program). So it can be estimated how much the percentage reduction prestress force on the bridge until PCI bridge structure collapses. From the calculation, it found that the pattern comparison between reduction prestressing force and natural frequency are linear. These results are also similar for natural frequency versus moment capacity.PCI bridge will collapse when the reduction prestreesing force of 45 % to 50 % from the total loss of prestressing.

  17. Conditional abrogation of Atm in osteoclasts extends osteoclast lifespan and results in reduced bone mass.

    PubMed

    Hirozane, Toru; Tohmonda, Takahide; Yoda, Masaki; Shimoda, Masayuki; Kanai, Yae; Matsumoto, Morio; Morioka, Hideo; Nakamura, Masaya; Horiuchi, Keisuke

    2016-09-28

    Ataxia-telangiectasia mutated (ATM) kinase is a central component involved in the signal transduction of the DNA damage response (DDR) and thus plays a critical role in the maintenance of genomic integrity. Although the primary functions of ATM are associated with the DDR, emerging data suggest that ATM has many additional roles that are not directly related to the DDR, including the regulation of oxidative stress signaling, insulin sensitivity, mitochondrial homeostasis, and lymphocyte development. Patients and mice lacking ATM exhibit growth retardation and lower bone mass; however, the mechanisms underlying the skeletal defects are not fully understood. In the present study, we generated mutant mice in which ATM is specifically inactivated in osteoclasts. The mutant mice did not exhibit apparent developmental defects but showed reduced bone mass due to increased osteoclastic bone resorption. Osteoclasts lacking ATM were more resistant to apoptosis and showed a prolonged lifespan compared to the controls. Notably, the inactivation of ATM in osteoclasts resulted in enhanced NF-κB signaling and an increase in the expression of NF-κB-targeted genes. The present study reveals a novel function for ATM in regulating bone metabolism by suppressing the lifespan of osteoclasts and osteoclast-mediated bone resorption.

  18. Acidic and alkaline bottom ash and composted manure blends as a soil amendment.

    PubMed

    Mukhtar, S; Sadaka, S S; Kenimer, A L; Rahman, S; Mathis, J G

    2008-09-01

    Potential water quality impacts associated with using bottom ash (BA) and composted dairy manure (CM) as a soil amendment were evaluated in this study. Two column studies were conducted to evaluate three blends of acidic BA and CM (BA:CM, v/v) namely, B1ac (95:5), B2ac (90:10), and B3ac (80:20) and three blends of alkaline BA and CM (BA:CM, v/v), namely, B1al (95:5), B2al (90:10), and B3al (80:20) under constant head water table conditions. Samples from standing water (top) and leachate (bottom) were collected at weekly intervals until day 49 to evaluate the effects of different blend ratios and elapsed time on standing water and leachate chemical and physical properties. A higher CM content in both acidic and alkaline blends resulted in higher leachate concentrations for solids and nutrients tested in this study. Alkaline blends had higher standing water and leachate nutrients concentration compared to acidic blends. After day 28, standing water total dissolved solids (TDS) concentrations for all acidic blends was below the USEPA drinking water standard however, TDS value for alkaline blend was always below the standard. Similar trends were also observed for NO3-N and phosphorus (P) concentrations for both blends. Based on these findings, it was concluded that acidic and alkaline blends B1ac, B1al, B2ac and B2al may be considered as a soil amendment material.

  19. Pilot-Scale Batch Alkaline Pretreatment of Corn Stover

    SciTech Connect

    Kuhn, Erik M.; O’Brien, Marykate H.; Ciesielski, Peter N.; Schell, Daniel J.

    2015-12-18

    The goal of biomass pretreatment is to increase the enzymatic digestibility of the plant cell wall polysaccharides to produce sugars for upgrading to biofuels. Alkaline pretreatment has the ability to solubilize much of the lignin in biomass while the carbohydrates remain insoluble. With an increased research focus to produce high-value products from lignin, a low molecular weight, lignin-rich stream in a biorefinery is desirable. Here, this work reports on batch alkaline pretreatment of corn stover conducted using a three-factor, two-level central composite experimental design in a pilot-scale reactor to determine the relationship between sodium hydroxide (NaOH) loading, temperature, and anthraquinone (AQ) charge on solids solubilization, component yields, and enzymatic digestibility of the residual solids. Operating conditions were 100 to 140 °C, 40 to 70 mg NaOH/g dry corn stover, and 0.05% to 0.2% (w/w) AQ loading. An enzymatic hydrolysis screening study was performed at 2% cellulose loading. Empirical modeling results showed that NaOH loading and temperature are both significant factors, solubilizing 15% to 35% of the solids and up to 54% of the lignin. Enzymatic hydrolysis of the residual solids produced good monomeric glucose (>90%) and xylose (>70%) yields at the more severe pretreatment conditions. We also found that the AQ charge was not a significant factor at the conditions studied, so efforts to reduce xylan and increase lignin solubilization using this compound were not successful. Lastly, while good lignin solubilization was achieved, effectively recovering this stream remains a challenge, and demonstrating performance in continuous reactors is still needed.

  20. Pilot-Scale Batch Alkaline Pretreatment of Corn Stover

    DOE PAGES

    Kuhn, Erik M.; O’Brien, Marykate H.; Ciesielski, Peter N.; ...

    2015-12-18

    The goal of biomass pretreatment is to increase the enzymatic digestibility of the plant cell wall polysaccharides to produce sugars for upgrading to biofuels. Alkaline pretreatment has the ability to solubilize much of the lignin in biomass while the carbohydrates remain insoluble. With an increased research focus to produce high-value products from lignin, a low molecular weight, lignin-rich stream in a biorefinery is desirable. Here, this work reports on batch alkaline pretreatment of corn stover conducted using a three-factor, two-level central composite experimental design in a pilot-scale reactor to determine the relationship between sodium hydroxide (NaOH) loading, temperature, and anthraquinonemore » (AQ) charge on solids solubilization, component yields, and enzymatic digestibility of the residual solids. Operating conditions were 100 to 140 °C, 40 to 70 mg NaOH/g dry corn stover, and 0.05% to 0.2% (w/w) AQ loading. An enzymatic hydrolysis screening study was performed at 2% cellulose loading. Empirical modeling results showed that NaOH loading and temperature are both significant factors, solubilizing 15% to 35% of the solids and up to 54% of the lignin. Enzymatic hydrolysis of the residual solids produced good monomeric glucose (>90%) and xylose (>70%) yields at the more severe pretreatment conditions. We also found that the AQ charge was not a significant factor at the conditions studied, so efforts to reduce xylan and increase lignin solubilization using this compound were not successful. Lastly, while good lignin solubilization was achieved, effectively recovering this stream remains a challenge, and demonstrating performance in continuous reactors is still needed.« less

  1. Efficient acquisition of iron confers greater tolerance to saline-alkaline stress in rice (Oryza sativa L.)

    PubMed Central

    Li, Qian; Yang, An; Zhang, Wen-Hao

    2016-01-01

    To elucidate the mechanisms underlying tolerance to saline-alkaline stress in two rice genotypes, Dongdao-4 and Jigeng-88, we exposed them to medium supplemented with 10 mM Na2CO3 and 40 mM NaCl (pH 8.5). Dongdao-4 plants displayed higher biomass, chlorophyll content, and photosynthetic rates, and a larger root system than Jigeng-88 under saline-alkaline conditions. Dongdao-4 had a higher shoot Na+/K+ ratio than Jigeng-88 under both control and saline-alkaline conditions. Dongdao-4 exhibited stronger rhizospheric acidification than Jigeng-88 under saline-alkaline conditions, resulting from greater up-regulation of H+-ATPases at the transcriptional level. Moreover, Fe concentrations in shoots and roots of Dongdao-4 were higher than those in Jigeng-88, and a higher rate of phytosiderophore exudation was detected in Dongdao-4 versus Jigeng-88 under saline-alkaline conditions. The Fe-deficiency-responsive genes OsIRO2, OsIRT1, OsNAS1, OsNAS2, OsYSL2, and OsYSL15 were more strongly up-regulated in Dongdao-4 than Jigeng-88 plants in saline-alkaline medium, implying greater tolerance of Dongdao-4 plants to Fe deficiency. To test this hypothesis, we compared the effects of Fe deficiency on the two genotypes, and found that Dongdao-4 was more tolerant to Fe deficiency. Exposure to Fe-deficient medium led to greater rhizospheric acidification and phytosiderophore exudation in Dongdao-4 than Jigeng-88 plants. Expression levels of OsIRO2, OsIRT1, OsNAS1, OsNAS2, OsYSL2, and OsYSL15 were higher in Dongdao-4 than Jigeng-88 plants under Fe-deficient conditions. These results demonstrate that a highly efficient Fe acquisition system together with a large root system may underpin the greater tolerance of Dongdao-4 plants to saline-alkaline stress. PMID:27811002

  2. Efficient acquisition of iron confers greater tolerance to saline-alkaline stress in rice (Oryza sativa L.).

    PubMed

    Li, Qian; Yang, An; Zhang, Wen-Hao

    2016-12-01

    To elucidate the mechanisms underlying tolerance to saline-alkaline stress in two rice genotypes, Dongdao-4 and Jigeng-88, we exposed them to medium supplemented with 10 mM Na2CO3 and 40 mM NaCl (pH 8.5). Dongdao-4 plants displayed higher biomass, chlorophyll content, and photosynthetic rates, and a larger root system than Jigeng-88 under saline-alkaline conditions. Dongdao-4 had a higher shoot Na(+)/K(+) ratio than Jigeng-88 under both control and saline-alkaline conditions. Dongdao-4 exhibited stronger rhizospheric acidification than Jigeng-88 under saline-alkaline conditions, resulting from greater up-regulation of H(+)-ATPases at the transcriptional level. Moreover, Fe concentrations in shoots and roots of Dongdao-4 were higher than those in Jigeng-88, and a higher rate of phytosiderophore exudation was detected in Dongdao-4 versus Jigeng-88 under saline-alkaline conditions. The Fe-deficiency-responsive genes OsIRO2, OsIRT1, OsNAS1, OsNAS2, OsYSL2, and OsYSL15 were more strongly up-regulated in Dongdao-4 than Jigeng-88 plants in saline-alkaline medium, implying greater tolerance of Dongdao-4 plants to Fe deficiency. To test this hypothesis, we compared the effects of Fe deficiency on the two genotypes, and found that Dongdao-4 was more tolerant to Fe deficiency. Exposure to Fe-deficient medium led to greater rhizospheric acidification and phytosiderophore exudation in Dongdao-4 than Jigeng-88 plants. Expression levels of OsIRO2, OsIRT1, OsNAS1, OsNAS2, OsYSL2, and OsYSL15 were higher in Dongdao-4 than Jigeng-88 plants under Fe-deficient conditions. These results demonstrate that a highly efficient Fe acquisition system together with a large root system may underpin the greater tolerance of Dongdao-4 plants to saline-alkaline stress.

  3. Conditions that may affect the results of susceptibility testing of Mycobacterium tuberculosis to pyrazinamide.

    PubMed

    Zhang, Ying; Permar, Sallie; Sun, Zhonghe

    2002-01-01

    Pyrazinamide (PZA) is an important front-line anti-tuberculosis drug that is active only at acid pH. However, acid pH causes significant difficulty for PZA susceptibility testing. A common problem in PZA testing is false resistance caused by large bacterial inocula. This study investigated the relationship of false resistance to numbers of bacilli, pH and other factors that potentially affect susceptibility to PZA. Large inocula (10(7-8) bacilli/ml) of M. tuberculosis H37Ra caused significant increase in medium pH from 5.5 towards neutrality, and thus produced false resistance results. The increase in medium pH was determined to be a function of live bacilli; heat-killed bacilli had little or no effect. Susceptibility to PZA and its active derivative pyrazinoic acid (POA) was comparable on 7H11 agar medium, but POA was less active than PZA in liquid medium containing bovine serum albumin (BSA), suggesting that susceptibility to PZA or POA was reduced in the presence of BSA, because of its neutralising effect on medium pH and significant POA binding. A 3-month-old H37Ra culture was shown to be more susceptible to PZA exposure than a 4-day log-phase culture, suggesting that PZA is more active for non-growing bacilli. Finally, reserpine, an inhibitor of POA efflux pump, increased susceptibility to PZA even near neutral pH 6.8, with an MIC of 400 mg/L compared with 1,000 mg/L without reserpine. These findings should have implications for understanding the mode of action of PZA and for PZA susceptibility testing.

  4. Composition of suberin extracted upon gradual alkaline methanolysis of Quercus suber L. cork.

    PubMed

    Lopes, M H; Gil, A M; Silvestre, A J; Neto, C P

    2000-02-01

    The monomeric composition of suberin extracts obtained by gradual alkaline methanolysis of Quercus suber cork was determined by gas chromatography-mass spectrometry (GC-MS). Results show that 1-alkanols and alkanoic and alpha,omega-alkanedioic acids are preferentially removed upon mild alkaline conditions, whereas mid-chain-modified omega-hydroxyalkanoic acids are preferentially removed under stronger alkaline conditions. Saturated omega-hydroxyalkanoic acids are found to be abundant in all suberin extracts. These results are consistent with two distinct suberin fractions with different locations in cork cell walls and/or esterification degrees. It is proposed that these fractions correlate with the two main suberin peaks in the solid state (13)C NMR spectra of cork and suberin extracts. Quantitative GC-MS analysis showed that suberin monomers comprise approximately 30% (w/w) of the suberin extracts, the remaining comprising nonvolatile structures with high M(n) values, as measured by vapor pressure osmometry. The presence of a large fraction of high molecular weight aliphatic structures in suberin extracts is supported by the corresponding NMR spectra.

  5. Metal adsorbent for alkaline etching aqua solutions of Si wafer

    NASA Astrophysics Data System (ADS)

    Tamada, Masao; Ueki, Yuji; Seko, Noriaki; Takeda, Toshihide; Kawano, Shin-ichi

    2012-08-01

    High performance adsorbent is expected to be synthesized for the removal of Ni and Cu ions from strong alkaline solution used in the surface etching process of Si wafer. Fibrous adsorbent was synthesized by radiation-induce emulsion graft polymerization onto polyethylene nonwoven fabric and subsequent amination. The reaction condition was optimized using 30 L reaction vessel and nonwoven fabric, 0.3 m width and 18 m long. The resulting fibrous adsorbent was evaluated by 48 wt% NaOH and KOH contaminated with Ni and Cu ions, respectively. The concentration levels of Ni and Cu ions was reduced to less than 1 μg/kg (ppb) at the flow rate of 10 h-1 in space velocity. The life of adsorbent was 30 times higher than that of the commercialized resin. This novel adsorbent was commercialized as METOLATE® since the ability of adsorption is remarkably higher than that of commercial resin used practically in Si wafer processing.

  6. Structural diversity of alkaline-earth 2,5-thiophenedicarboxylates

    NASA Astrophysics Data System (ADS)

    Balendra; Ramanan, Arunachalam

    2017-03-01

    Exploration of the structural landscape of the system containing divalent alkaline-earth metal ion (Mg, Ca and Sr) with the rigid 2,5-thiophenedicarboxylic acid (TDC) under varying solvothermal condition (DMF, DMA and DEF) yielded five new crystals: [Mg(TDC) (DEF)2(H2O)1/2] (1), [Ca(TDC) (DMA)] (2), [Ca(TDC) (DMA) (H2O)] (3), [Sr(TDC) (DMA)] (4) and [Sr(TDC) (DMA) (H2O)] (5) and two known solids. Single crystal structures of all the solids are characteristic of extended coordination interaction between metal and carboxylate ions. While the smaller magnesium ion crystallized into a 2D coordination polymer, the larger calcium and strontium compounds resulted into the growth of 3D metal organic frameworks. All the solids show blue emission arising from intra ligand charge transfer.

  7. Surfactant and adhesive formulations from alkaline biomass extracts

    NASA Astrophysics Data System (ADS)

    Baxter, Matthew

    This work studies the ability to produce effective surfactant and adhesive formulations using surface active biological material extracted from different biomass sources using alkaline extraction methods. Two urban waste biomass sources were used to produce surfactants, Return Activated Sludge (RAS), and solid Urban Refuse (UR). The third biomass source investigated was isolated mustard protein (MP). RAS and MP extracts were investigated for adhesive production. The results indicate that extracts from the waste biomass sources, RAS and UR, can be combined with a commercial surfactant, sodium dioctyl sulfosuccinate (AOT), to produce surfactants with low interfacial tensions against various oils. These highly surface-active formulations were shown to be useful in the removal of bitumen from contaminated sand. RAS and MP showed potential as protein-based wood adhesives. These sources were used in adhesive formulations to produce a strong bond strength under low-pressure, ambient pressing conditions.

  8. Alkaline pretreatment for chlorine removal from high-chlorine rhodochrosite

    NASA Astrophysics Data System (ADS)

    Zhang, Xing-ran; Liu, Zuo-hua; Li, Wen-sheng; Cheng, Ya-ya; Du, Jun; Tao, Chang-yuan

    2016-11-01

    Chloride in manganese ore adversely affects mineral extraction. The mechanisms and the factors that influence an alkali pretreatment to removal chlorine from manganese ore were explored to eliminate hazards posed by chlorine during the electrolysis of manganese. The results showed that sodium carbonate, when used as an alkaline additive, promoted the dissolution of insoluble chloride, enhanced the migration of chloride ions, and effectively stabilized Mn2+. The optimal conditions were a sodium carbonate concentration of 0.45 mol·L-1, a liquid-solid ratio of 5:1 mL·g-1, a reaction time of 1 h, and a temperature of 25°C. The chlorine removal efficiency was greater than 95%, and the ore grade (Mn) was increased by 2.7%.

  9. JaCVAM-organized international validation study of the in vivo rodent alkaline comet assay for the detection of genotoxic carcinogens: I. Summary of pre-validation study results.

    PubMed

    Uno, Yoshifumi; Kojima, Hajime; Omori, Takashi; Corvi, Raffaella; Honma, Masamistu; Schechtman, Leonard M; Tice, Raymond R; Burlinson, Brian; Escobar, Patricia A; Kraynak, Andrew R; Nakagawa, Yuzuki; Nakajima, Madoka; Pant, Kamala; Asano, Norihide; Lovell, David; Morita, Takeshi; Ohno, Yasuo; Hayashi, Makoto

    2015-07-01

    The in vivo rodent alkaline comet assay (comet assay) is used internationally to investigate the in vivo genotoxic potential of test chemicals. This assay, however, has not previously been formally validated. The Japanese Center for the Validation of Alternative Methods (JaCVAM), with the cooperation of the U.S. NTP Interagency Center for the Evaluation of Alternative Toxicological Methods (NICEATM)/the Interagency Coordinating Committee on the Validation of Alternative Methods (ICCVAM), the European Centre for the Validation of Alternative Methods (ECVAM), and the Japanese Environmental Mutagen Society/Mammalian Mutagenesis Study Group (JEMS/MMS), organized an international validation study to evaluate the reliability and relevance of the assay for identifying genotoxic carcinogens, using liver and stomach as target organs. The ultimate goal of this validation effort was to establish an Organisation for Economic Co-operation and Development (OECD) test guideline. The purpose of the pre-validation studies (i.e., Phase 1 through 3), conducted in four or five laboratories with extensive comet assay experience, was to optimize the protocol to be used during the definitive validation study.

  10. Mesozoic mafic alkaline magmatism of southern Scandinavia

    NASA Astrophysics Data System (ADS)

    Tappe, Sebastian

    2004-11-01

    More than 100 volcanic necks in central Scania (southern Sweden) are the product of Jurassic continental rift-related mafic alkaline magmatism at the southwest margin of the Baltic Shield. They are mainly basanites, with rarer melanephelinites. Both rock groups display overlapping primitive Mg-numbers, Cr and Ni contents, steep chondrite-normalized rare earth element patterns (LaN /YbN = 17 27) and an overall enrichment in incompatible elements. However, the melanephelinites are more alkaline and have stronger high field strength element enrichment than the basanites. The existence of distinct primary magmas is also indicated by heterogeneity in highly incompatible element ratios (e.g. Zr/Nb, La/Nb). Trace element modelling indicates that the magmas were generated by comparably low degrees of melting of a heterogeneous mantle source. Such a source can best be explained by a metasomatic overprint of the mantle lithosphere by percolating evolved melts. The former existence of such alkaline trace element-enriched melts can be demonstrated by inversion of the trace element content of green-core clinopyroxenes and anorthoclase which occur as xenocrysts in the melanephelinites and are interpreted as being derived from crystallization of evolved mantle melts. Jurassic magmatic activity in Scania was coeval with the generation of nephelinites in the nearby Egersund Basin (Norwegian North Sea). Both Scanian and North Sea alkaline magmas share similar trace element characteristics. Mantle enrichment processes at the southwest margin of the Baltic Shield and the North Sea Basin generated trace element signatures similar to those of ocean island basalts (e.g. low Zr/Nb and La/Nb) but there are no indications of plume activity during the Mesozoic in this area. On the contrary, the short duration of rifting, absence of extensive lithospheric thinning, and low magma volumes argue against a Mesozoic mantle plume. It seems likely that the metasomatic imprint resulted from the

  11. Priming effect of abscisic acid on alkaline stress tolerance in rice (Oryza sativa L.) seedlings.

    PubMed

    Wei, Li-Xing; Lv, Bing-Sheng; Wang, Ming-Ming; Ma, Hong-Yuan; Yang, Hao-Yu; Liu, Xiao-Long; Jiang, Chang-Jie; Liang, Zheng-Wei

    2015-05-01

    Saline-alkaline stress is characterized by high salinity and high alkalinity (high pH); alkaline stress has been shown to be the primary factor inhibiting rice seedling growth. In this study, we investigated the potential priming effect of abscisic acid (ABA) on tolerance of rice seedlings to alkaline stress simulated by Na2CO3. Seedlings were pretreated with ABA at concentrations of 0 (control), 10, and 50 μM by root-drench for 24 h and then transferred to a Na2CO3 solution that did not contain ABA. Compared to control treatment, pretreatment with ABA substantially improved the survival rate of rice seedlings and increased biomass accumulation after 7 days under the alkaline condition. ABA application at 10 μM also alleviated the inhibitory effects of alkaline stress on the total root length and root surface area. Physiologically, ABA increased relative water content (RWC) and decreased cell membrane injury degree (MI) and Na(+)/K(+) ratios. In contrast, fluridone (an ABA biosynthesis inhibitor) decreased the RWC and increased MI in shoots under the alkaline conditions. These data suggest that ABA has a potent priming effect on the adaptive response to alkaline stress in rice and may be useful for improving rice growth in saline-alkaline paddy fields.

  12. Nucleotide sequences encoding a thermostable alkaline protease

    DOEpatents

    Wilson, David B.; Lao, Guifang

    1998-01-01

    Nucleotide sequences, derived from a thermophilic actinomycete microorganism, which encode a thermostable alkaline protease are disclosed. Also disclosed are variants of the nucleotide sequences which encode a polypeptide having thermostable alkaline proteolytic activity. Recombinant thermostable alkaline protease or recombinant polypeptide may be obtained by culturing in a medium a host cell genetically engineered to contain and express a nucleotide sequence according to the present invention, and recovering the recombinant thermostable alkaline protease or recombinant polypeptide from the culture medium.

  13. Nucleotide sequences encoding a thermostable alkaline protease

    DOEpatents

    Wilson, D.B.; Lao, G.

    1998-01-06

    Nucleotide sequences, derived from a thermophilic actinomycete microorganism, which encode a thermostable alkaline protease are disclosed. Also disclosed are variants of the nucleotide sequences which encode a polypeptide having thermostable alkaline proteolytic activity. Recombinant thermostable alkaline protease or recombinant polypeptide may be obtained by culturing in a medium a host cell genetically engineered to contain and express a nucleotide sequence according to the present invention, and recovering the recombinant thermostable alkaline protease or recombinant polypeptide from the culture medium. 3 figs.

  14. Acid transformation of bauxite residue: Conversion of its alkaline characteristics.

    PubMed

    Kong, Xiangfeng; Li, Meng; Xue, Shengguo; Hartley, William; Chen, Chengrong; Wu, Chuan; Li, Xiaofei; Li, Yiwei

    2017-02-15

    Bauxite residue (BR) is a highly alkaline solid hazardous waste produced from bauxite processing for alumina production. Alkaline transformation appears to reduce the environmental risk of bauxite residue disposal areas (BRDAs) whilst potentially providing opportunities for the sustainable reuse and on-going management of BR. Mineral acids, a novel citric acid and a hybrid combination of acid-gypsum treatments were investigated for their potential to reduce residue pH and total alkalinity and transform the alkaline mineral phase. XRD results revealed that with the exception of andradite, the primary alkaline solid phases of cancrinite, grossular and calcite were transformed into discriminative products based on the transformation used. Supernatants separated from BR and transformed bauxite residue (TBR) displayed distinct changes in soluble Na, Ca and Al, and a reduction in pH and total alkalinity. SEM images suggest that mineral acid transformations promote macro-aggregate formation, and the positive promotion of citric acid, confirming the removal or reduction in soluble and exchangeable Na. NEXAFS analysis of Na K-edge revealed that the chemical speciation of Na in TBRs was consistent with BR. Three acid treatments and gypsum combination had no effect on Na speciation, which affects the distribution of Na revealed by sodium STXM imaging.

  15. Acid esterification-alkaline transesterification process for methyl ester production from crude rubber seed oil.

    PubMed

    Thaiyasuit, Prachasanti; Pianthong, Kulachate; Worapun, Ittipon

    2012-01-01

    This study aims to examine methods and the most suitable conditions for producing methyl ester from crude rubber seed oil. An acid esterification-alkaline transesterification process is proposed. In the experiment, the 20% FFA of crude rubber seed oil could be reduced to 3% FFA by acid esterification. The product after esterified was then tranesterified by alkaline transesterification process. By this method, the maximum yield of methyl ester was 90% by mass. The overall consumption of methanol was 10.5:1 by molar ratio. The yielded methyl ester was tested for its fuel properties and met required standards. The major fatty acid methyl ester compositions were analyzed and constituted of methyl linoleate 41.57%, methyl oleate 24.87%, and methyl lonolenate 15.16%. Therefore, the cetane number of methyl ester could be estimated as 47.85, while the tested result of motor cetane number was 51.20.

  16. Modeling the effect of membrane conductivity on the performance of alkaline fuel cells

    NASA Astrophysics Data System (ADS)

    Raya, Isaac P.; Ellis, Michael W.; Hernandez-Guerrero, Abel; Elizalde-Blancas, Francisco

    2016-03-01

    The present work proposes and demonstrates a methodology to capture the effect of operating conditions on ionic conductivity of membranes immersed in alkaline media. Based on reported experimental results for an anion exchange membrane (A-201 by Tokuyama) and a cation exchange membrane (Nafion 211), two novel expressions are developed for the ionic conductivity by incorporating the effects of solution concentration and temperature. The expression for the cationic conductivity is applied in a cell-level model to predict the performance of an alkaline direct borohydride fuel cell; it is found that the membrane ionic conductivity significantly affects the cell performance and capturing its functionality is essential to accurately predict the fuel cell performance.

  17. The Alkaline Dissolution Rate of Calcite.

    PubMed

    Colombani, Jean

    2016-07-07

    Due to the widespread presence of calcium carbonate on Earth, several geochemical systems, among which is the global CO2 cycle, are controlled to a large extent by the dissolution and precipitation of this mineral. For this reason, the dissolution of calcite has been thoroughly investigated for decades. Despite this intense activity, a consensual value of the dissolution rate of calcite has not been found yet. We show here that the inconsistency between the reported values stems mainly from the variability of the chemical and hydrodynamic conditions of measurement. The spreading of the values, when compared in identical conditions, is much less than expected and is interpreted in terms of sample surface topography. This analysis leads us to propose benchmark values of the alkaline dissolution rate of calcite compatible with all the published values, and a method to use them in various chemical and hydrodynamic contexts.

  18. Yield performance of cowpea genotypes grown in alkaline soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cowpea or Southernpea [Vigna unguiculata (L.) Walp.] is an important legume crop used as a feed for livestock, as a green vegetable and for consumption of its dry beans which provide 22-25% protein. The crop is very sensitive to alkaline soil conditions. When grown at soil pH of 7.5 or higher, cowp...

  19. Field screening of cowpea cultivars for alkaline soil tolerance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cowpea or Southernpea [Vigna unguiculata (L.) Walp.] is an important legume crop used as a feed for livestock, as a green vegetable and for consumption of its dry beans which provide 22-25% protein. The crop is very sensitive to alkaline soil conditions. When grown at soil pH of 7.5 or higher, cowp...

  20. 17 CFR 229.303 - (Item 303) Management's discussion and analysis of financial condition and results of operations.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... certainty of cash flows from operations and from outside sources. 3. The discussion and analysis shall focus...) and (2) of this Item. The discussion and analysis shall include a discussion of material changes in... discussion and analysis of financial condition and results of operations. 229.303 Section 229.303...

  1. Helping Students to Learn the English Second Conditional by Blending Internet Resources with Virtual Worlds: The Results of a Study

    ERIC Educational Resources Information Center

    Kruk, Mariusz

    2013-01-01

    The paper presents the results of a study whose main aim was to investigate the effectiveness of using Internet resources and a browser-based virtual world in helping a group of students to learn the English second conditional. The sample consisted of thirteen third year students studying English at a Polish senior high school. The data were…

  2. 17 CFR 229.303 - (Item 303) Management's discussion and analysis of financial condition and results of operations.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... discussion and analysis of financial condition and results of operations. 229.303 Section 229.303 Commodity... 1975-REGULATION S-K Financial Information § 229.303 (Item 303) Management's discussion and analysis of... registrant's discussion and analysis shall be of the financial statements and other statistical data that...

  3. 17 CFR 229.303 - (Item 303) Management's discussion and analysis of financial condition and results of operations.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... discussion and analysis of financial condition and results of operations. 229.303 Section 229.303 Commodity... 1975-REGULATION S-K Financial Information § 229.303 (Item 303) Management's discussion and analysis of... registrant's discussion and analysis shall be of the financial statements and other statistical data that...

  4. The secondary alkaline zinc electrode

    NASA Astrophysics Data System (ADS)

    McLarnon, Frank R.; Cairns, Elton J.

    1991-02-01

    The worldwide studies conducted between 1975 and 1990 with the aim of improving cell lifetimes of secondary alkaline zinc electrodes are overviewed. Attention is given the design features and characteristics of various secondary alkaline zinc cells, including four types of zinc/nickel oxide cell designs (vented static-electrolyte, sealed static-electrolyte, vibrating-electrode, and flowing-electrolyte); two types of zinc/air cells (mechanically rechargeable consolidated-electrode and mechanically rechargeable particulate-electrode); zinc/silver oxide battery; zinc/manganese dioxide cell; and zinc/ferric cyanide battery. Particular consideration is given to recent research in the fields of cell thermodynamics, zinc electrodeposition, zinc electrodissolution, zinc corrosion, electrolyte properties, mathematical and phenomenological models, osmotic pumping, nonuniform current distribution, and cell cycle-life perforamnce.

  5. Development of alkaline fuel cells.

    SciTech Connect

    Hibbs, Michael R.; Jenkins, Janelle E.; Alam, Todd Michael; Janarthanan, Rajeswari; Horan, James L.; Caire, Benjamin R.; Ziegler, Zachary C.; Herring, Andrew M.; Yang, Yuan; Zuo, Xiaobing; Robson, Michael H.; Artyushkova, Kateryna; Patterson, Wendy; Atanassov, Plamen Borissov

    2013-09-01

    This project focuses on the development and demonstration of anion exchange membrane (AEM) fuel cells for portable power applications. Novel polymeric anion exchange membranes and ionomers with high chemical stabilities were prepared characterized by researchers at Sandia National Laboratories. Durable, non-precious metal catalysts were prepared by Dr. Plamen Atanassovs research group at the University of New Mexico by utilizing an aerosol-based process to prepare templated nano-structures. Dr. Andy Herrings group at the Colorado School of Mines combined all of these materials to fabricate and test membrane electrode assemblies for single cell testing in a methanol-fueled alkaline system. The highest power density achieved in this study was 54 mW/cm2 which was 90% of the project target and the highest reported power density for a direct methanol alkaline fuel cell.

  6. Escherichia coli alkaline phosphatase. Kinetic studies with the tetrameric enzyme.

    PubMed

    Halford, S E; Schlesinger, M J; Gutfreund, H

    1972-03-01

    1. The stability of the tetrameric form of Escherichia coli alkaline phosphatase was examined by analytical ultracentrifugation. 2. The stopped-flow technique was used to study the hydrolysis of nitrophenyl phosphates by the alkaline phosphatase tetramer at pH7.5 and 8.3. In both cases transient product formation was observed before the steady state was attained. Both transients consisted of the liberation of 1mol of nitrophenol/2mol of enzyme subunits within the dead-time of the apparatus. The steady-state rates were identical with those observed with the dimer under the same conditions. 3. The binding of 2-hydroxy-5-nitrobenzyl phosphonate to the alkaline phosphatase tetramer was studied by the temperature-jump technique. The self-association of two dimers to form the tetramer is linked to a conformation change within the dimer. This accounts for the differences between the transient phases in the reactions of the dimer and the tetramer with substrate. 4. Addition of P(i) to the alkaline phosphatase tetramer caused it to dissociate into dimers. The tetramer is unable to bind this ligand. It is suggested that the tetramer undergoes a compulsory dissociation before the completion of its first turnover with substrate. 5. On the basis of these findings a mechanism is proposed for the involvement of the alkaline phosphatase tetramer in the physiology of E. coli.

  7. Field measurement of alkalinity and pH

    USGS Publications Warehouse

    Barnes, Ivan

    1964-01-01

    The behavior of electrometric pH equipment under field conditions departs from the behavior predicted from Nernst's law. The response is a linear function of pH, and hence measured pH values may be corrected to true pH if the instrument is calibrated with two reference solutions for each measurement. Alkalinity titrations may also be made in terms of true pH. Standard methods, such as colorimetric titrations, were rejected as unreliable or too cumbersome for rapid field use. The true pH of the end point of the alkalinity titration as a function of temperature, ionic strength, and total alkalinity has been calculated. Total alkalinity in potable waters is the most important factor influencing the end point pH, which varies from 5.38 (0 ? C, 5 ppm (parts per million) HC0a-) to 4.32 (300 ppm HC0a-,35 ? C), for the ranges of variables considered. With proper precautions, the pH may be determined to =i:0.02 pH and the alkalinity to =i:0.6 ppm HCO3- for many naturally occurring bodies of fresh water.

  8. Alkaline Comet Assay for Assessing DNA Damage in Individual Cells.

    PubMed

    Pu, Xinzhu; Wang, Zemin; Klaunig, James E

    2015-08-06

    Single-cell gel electrophoresis, commonly called a comet assay, is a simple and sensitive method for assessing DNA damage at the single-cell level. It is an important technique in genetic toxicological studies. The comet assay performed under alkaline conditions (pH >13) is considered the optimal version for identifying agents with genotoxic activity. The alkaline comet assay is capable of detecting DNA double-strand breaks, single-strand breaks, alkali-labile sites, DNA-DNA/DNA-protein cross-linking, and incomplete excision repair sites. The inclusion of digestion of lesion-specific DNA repair enzymes in the procedure allows the detection of various DNA base alterations, such as oxidative base damage. This unit describes alkaline comet assay procedures for assessing DNA strand breaks and oxidative base alterations. These methods can be applied in a variety of cells from in vitro and in vivo experiments, as well as human studies.

  9. DNA-based determination of microbial biomass suitable for frozen and alkaline soil samples

    NASA Astrophysics Data System (ADS)

    Semenov, Mikhail; Blagodatskaya, Evgeniya; Kogut, Boris; Kuzyakov, Yakov

    2015-04-01

    Microbial biomass is a sensitive indicator of changes due to soil management, long before other basic soil measures such as Corg or Ntot. Improvement of methods for determination of microbial biomass still remains relevant, and these methods should be correctly applicable for the soil samples being in various state. This study was designed to demonstrate the applicability of DNA-based determination of microbial biomass under conditions when the common basic approaches, namely chloroform fumigation-extraction (CFE) and substrate-induced respiration (SIR), are restricted by certain soil properties, experimental designs or research needs, e.g. in frozen, alkaline or carbonaceous soils. We compared microbial biomass determined by CFE, SIR and by DNA approaches in the range of neutral and slightly alkaline Chernozem and alkaline Calcisol of semi-arid climate. The samples of natural and agricultural ecosystems were taken throughout the soil profile from long-term static field experiments in the European part of Russia. Extraction and subsequent quantification of dsDNA revealed a strong agreement with SIR and CFE when analyzing the microbial biomass content in soils with pH below 8. The conversion factors (FDNA) from dsDNA to SIR-Cmic (5.10) and CFE-Cmic (4.41) were obtained by testing a range of the soil samples down to 1.5 m depth and indicated a good reproducibility of DNA-based estimations. In alkaline soils (pH > 8), CO2 retention due to alkaline pH and exchange with carbonates resulted in a strong underestimation of soil microbial biomass by SIR or even in the absence of any CO2 emission, especially at low absolute values of microbial biomass in subsoil. Correction of CO2 efflux by theoretical retention pH-dependent factors caused overestimation of SIR-biomass. In alkaline conditions, DNA extraction proved to be a reliable alternative for microbial biomass determination. Moreover, the DNA-based approach can serve as an excellent alternative enabling correct

  10. Desialylated alkaline phosphatase: activation by 4-nitrophenol.

    PubMed

    Nayudu, P R

    1984-01-01

    Mouse ileal alkaline phosphatase is a sialyl enzyme (12-14 moles per mole of enzyme). When partially desialylated by treatment with neuraminidase, the enzyme loses most of its activity, associated with reduced apparent Vmax and Km. Part of that loss, however, is recovered as the product 4-nitrophenol's concentration builds up in the cuvette. Experimental results are presented to demonstrate that the activation is due to the binding of 4-nitrophenol as a ligand by the partially desialylated enzyme and that both the loss of activity by sialic acid removal and activation by ligand-binding are correlated with changes in protein conformation.

  11. Assessment of Environmental Qualification Practices and Condition Monitoring Techniques for Low-Voltage Electric Cables: LOCA Test Results

    SciTech Connect

    Lofaro, R.; Grove, E.; Villaran, M.; Soo, P.; Hsu, F.

    2001-02-01

    This report documents the results of a research program addressing issues related to the qualification process for low-voltage instrumentation and control (I&C) electric cables used in commercial nuclear power plants. Three commonly used types of I&C cable were tested: Cross-Linked Polyethylene (XLPE) insulation with a Neoprene® jacket, Ethylene Propylene Rubber (EPR) insulation with an unbonded Hypalon® jacket, and EPR with a bonded Hypalon® jacket. Each cable type received accelerated aging to simulate 20, 40, and 60 years of qualified life. In addition, naturally aged cables of the same types were obtained from decommissioned nuclear power plants and tested. The cables were subjected to simulated loss-of-coolant-accident (LOCA) conditions, which included the sequential application of LOCA radiation followed by exposure to steam at high temperature and pressure, as well as to chemical spray. Periodic condition monitoring (CM) was performed using nine different techniques to obtain data on the condition of the cable, as well as to evaluate the effectiveness of those CM techniques for in situ monitoring of cables. Volume 1 of this report presents the results of the LOCA tests, and Volume 2 discusses the results of the condition monitoring tests.

  12. Effects of acrosomal conditions of frozen-thawed spermatozoa on the results of artificial insemination in Japanese Black cattle.

    PubMed

    Kishida, Kazumi; Sakase, Mitsuhiro; Minami, Kenta; Arai, Miyuki M; Syoji, Reiko; Kohama, Namiko; Akiyama, Takayuki; Oka, Akio; Harayama, Hiroshi; Fukushima, Moriyuki

    2015-01-01

    The purposes of this study were to examine the relationship between male artificial insemination (AI) fertility and sperm acrosomal conditions assessed by new and conventional staining techniques and to identify possible reproductive dysfunctions causing low conception rates in AI using frozen-thawed spermatozoa with poor acrosomal conditions in Japanese Black bulls. We investigated individual differences among bulls in the results concerning (1) acrosomal conditions of frozen-thawed spermatozoa as assessed by not merely peanut agglutinin-lectin staining (a conventional staining technique) but also immunostaining of acrosomal tyrosine-phosphorylated proteins (a new staining technique), (2) routine AI using frozen-thawed spermatozoa as assessed by pregnancy diagnosis, (3) in vivo fertilization of frozen-thawed spermatozoa and early development of fertilized eggs as assessed by superovulation/AI-embryo collection tests and (4) in vitro fertilization of frozen-thawed spermatozoa with oocytes. The percentages of frozen-thawed spermatozoa with normal acrosomal conditions assessed by the abovementioned staining techniques were significantly correlated with the conception rates of routine AI, rates of transferable embryos in superovulation/AI-embryo collection tests and in vitro fertilization rates. These results are consistent with new suggestions that the distribution of acrosomal tyrosine-phosphorylated proteins as well as the acrosomal morphology of frozen-thawed spermatozoa are AI fertility-associated markers that are valid for the prediction of AI results and that low conception rates in AI using frozen-thawed spermatozoa with poor acrosomal conditions result from reproductive dysfunctions in the processes between sperm insemination into females and early embryo development, probably failed fertilization of frozen-thawed spermatozoa with oocytes.

  13. Simplified Space Conditioning in Low-Load Homes: Results from the Fresno, California, Retrofit Unoccupied Test House

    SciTech Connect

    Stecher, Dave; Poerschke, Andrew

    2014-02-01

    In this study, the Building America team, IBACOS, sought to determine cost-effective, energy-efficient solutions for heating and cooling houses. To this end, the team performed field testing in a retrofit unoccupied test house in Fresno, California, to evaluate three air-based heating, ventilation, and air conditioning (HVAC) distribution systems during heating, cooling, and midseason conditions. These included a typical airflow ducted system to the bedrooms, a low airflow ducted system to the bedrooms, and a system with no ductwork to the bedrooms. The relative ability of each of the three systems was assessed with respect to relevant Air Conditioning Contractors of America (ACCA) and ASHRAE standards for house temperature uniformity and stability, respectively. Computational fluid dynamics modeling also was performed and refined based on comparison to field test results to determine the air flow rate into the bedrooms of over-door and bottom-of-door air transfer grilles.

  14. Simplified Space Conditioning in Low-Load Homes: Results from the Fresno, California, Retrofit Unoccupied Test House

    SciTech Connect

    Stecher, D.; Poerschke, A.

    2014-02-01

    Field testing was performed in a retrofit unoccupied test house in Fresno, California. Three air-based heating, ventilation, and air conditioning (HVAC) distribution systems -- a typical airflow ducted system to the bedrooms, a low airflow ducted system to the bedrooms, and a system with no ductwork to the bedrooms -- were evaluated during heating, cooling, and midseason conditions. The relative ability of each of the three systems was assessed with respect to relevant Air Conditioning Contractors of America (ACCA) and ASHRAE standards for house temperature uniformity and stability, respectively. Computational fluid dynamics (CFD) modeling also was performed and refined based on comparison to field test results to determine the air flow rate into the bedrooms of over-door and bottom-of-door air transfer grilles.

  15. Alkaline twin-screw extrusion pretreatment for fermentable sugar production

    PubMed Central

    2013-01-01

    Background The inevitable depletion of fossil fuels has resulted in an increasing worldwide interest in exploring alternative and sustainable energy sources. Lignocellulose, which is the most abundant biomass on earth, is widely regarded as a promising raw material to produce fuel ethanol. Pretreatment is an essential step to disrupt the recalcitrance of lignocellulosic matrix for enzymatic saccharification and bioethanol production. This paper established an ATSE (alkaline twin-screw extrusion pretreatment) process using a specially designed twin-screw extruder in the presence of alkaline solution to improve the enzymatic hydrolysis efficiency of corn stover for the production of fermentable sugars. Results The ATSE pretreatment was conducted with a biomass/liquid ratio of 1/2 (w/w) at a temperature of 99°C without heating equipment. The results indicated that ATSE pretreatment is effective in improving the enzymatic digestibility of corn stover. Sodium hydroxide loading is more influential factor affecting both sugar yield and lignin degradation than heat preservation time. After ATSE pretreatment under the proper conditions (NaOH loading of 0.06 g/g biomass during ATSE and 1 hour heat preservation after extrusion), 71% lignin removal was achieved and the conversions of glucan and xylan in the pretreated biomass can reach to 83% and 89% respectively via subsequent enzymatic hydrolysis (cellulase loading of 20 FPU/g-biomass and substrate consistency of 2%). About 78% of the original polysaccharides were converted into fermentable sugars. Conclusions With the physicochemical functions in extrusion, the ATSE method can effectively overcome the recalcitrance of lignocellulose for the production of fermentable sugars from corn stover. This process can be considered as a promising pretreatment method due to its relatively low temperature (99°C), high biomass/liquid ratio (1/2) and satisfied total sugar yield (78%), despite further study is needed for process

  16. Adolescent traumatic stress experience results in less robust conditioned fear and post-extinction fear cue responses in adult rats.

    PubMed

    Moore, Nicole L T; Gauchan, Sangeeta; Genovese, Raymond F

    2014-05-01

    Early exposure to a traumatic event may produce lasting effects throughout the lifespan. Traumatic stress during adolescence may deliver a distinct developmental insult compared with more-often studied neonatal or juvenile traumatic stress paradigms. The present study describes the lasting effects of adolescent traumatic stress upon adulthood fear conditioning. Adolescent rats were exposed to a traumatic stressor (underwater trauma, UWT), then underwent fear conditioning during adulthood. Fear extinction was tested over five conditioned suppression extinction sessions three weeks later. The efficacies of two potential extinction-enhancing compounds, endocannabinoid reuptake inhibitor AM404 (10mg/kg) and M1 muscarinic positive allosteric modulator BQCA (10mg/kg), were also assessed. Finally, post-extinction fear responses were examined using a fear cue (light) as a prepulse stimulus. Rats traumatically stressed during adolescence showed blunted conditioned suppression on day 1 of extinction training, and AM404 reversed this effect. Post-extinction startle testing showed that fear conditioning eliminates prepulse inhibition to the light cue. Startle potentiation was observed only in rats without adolescent UWT exposure. AM404 and BQCA both ameliorated this startle potentiation, while BQCA increased startle in the UWT group. These results suggest that exposure to a traumatic stressor during adolescence alters developmental outcomes related to stress response and fear extinction compared to rats without adolescent traumatic stress exposure, blunting the adulthood fear response and reducing residual post-extinction fear expression. Efficacy of pharmacological interventions may also vary as a factor of developmental traumatic stress exposure.

  17. Serum N-telopeptide of type I collagen and bone alkaline phosphatase and their relationship in patients with non-small cell lung carcinoma and bone metastases. Preliminary results.

    PubMed

    Lumachi, Franco; Marino, Filippo; Fanti, Giovanni; Chiara, Giordano B; Basso, Stefano M M

    2011-11-01

    Lung cancer represents the most common malignancy in Western countries and the presence of bone metastasis (BMs) may significantly worsen the prognosis. Several urinary and serum markers are altered in patients with BMs from non-small cell lung cancer (NSCLC). The aim of this study was to assess the usefulness of two serum markers of bone remodeling in patients with NSCLC and BMs. Thirty-five patients (24 men, 11 women, median age 63 years, range 51-72 years) with NSCLC were examined. There were 16 patients with confirmed BMs (Group A), and 19 age-matched (63.5±4.9 vs. 63.7±4.4 years; p=0.88) patients without BMs (Group B). Serum levels of bone resorption marker cross-linked amino-terminal telopeptide of type I collegen (NTx), and bone formation marker bone alkaline phosphatase (BAP) were measured in both groups by enzyme-linked immunosorbent assay. Both NTx (33.5±7.2 vs. 25.6±3.1 nM bone collagen equivalent, BCE/l) and BAP (51.7±6.0 vs. 40.7±7.3 U/l) serum levels were significantly (p<0.001) different between groups (A vs. B). Using a cut-off value of 30 nM BCE/l (TNx) and 50 U/l (BAP), the sensitivity was 56.2% and 37.5%, respectively (Odds ratio, OR=0.47, 95% confidence interval, CI 0.11-1.91, p=0.48), while the specificity was 89.5% and 84.2% (OR=0.62, 95% CI 0.09-4.26, p=0.50), respectively. No correlation was found between age and both NTx (R=-0.34, p=0.08) and BAP (R=-0.10, p=0.61) among patients with BMs. In conclusion, in patients with NSCLC and BMs both NTx and BAP are specific markers of bone remodeling, but their usefulness is limited in early diagnosis of metastatic disease.

  18. On the formulation of new explicit conditions for steepness from a former result of N.N. Nekhoroshev

    NASA Astrophysics Data System (ADS)

    Schirinzi, Gabriella; Guzzo, Massimiliano

    2013-07-01

    The application of the Nekhoroshev theorem to many problems arising in different fields of Physics and Astronomy depends on a non-degeneracy property, called steepness, that a suitable Hamiltonian approximation must satisfy. Since steepness is implicitly defined, we have the problem of recognizing whether a given function is steep or not. For this purpose, we here consider some sufficient conditions for steepness provided by Nekhoroshev in 1979, based on the solvability of a collection of systems depending on the number n of degrees of freedom, the derivatives of the function up to a certain order r, and some auxiliary parameters. These conditions are really explicit only for r = 2, corresponding to quasi-convexity, and for r = 3. Instead, for r ⩾ 4, the conditions are implicit, since they require an elaborate computation of the closure of a certain set. In this paper, we first revisit Nekhoroshev's result and we show that the number of parameters in the collections of systems can be suitably reduced. Then, we show that for r = 4 Nekhoroshev's result is interesting only for n = 2, 3, and 4, and in these cases we find explicit conditions for steepness which are formulated in a purely algebraic form.

  19. Geochemical modeling of the influence of silicate mineral alteration on alkalinity production and carbonate precipitation

    NASA Astrophysics Data System (ADS)

    Herda, Gerhard; Kraemer, Stephan M.; Gier, Susanne; Meister, Patrick

    2016-04-01

    High CO2 partial pressure (pCO2) in deep rock reservoirs causes acidification of the porefluid. Such conditions occur during injection and subsurface storage of CO2 (to prevent the release of greenhouse gas) but also naturally in zones of strong methanogenic microbial activity in organic matter-rich ocean margin sediments. The acidic fluids are corrosive to carbonates and bear the risk of leakage of CO2 gas to the surface. Porefluid acidification may be moderated by processes that increase the alkalinity, i.e. that produce weak acid anions capable of buffering the acidification imposed by the CO2. Often, alkalinity increases as a result of anaerobic microbial activity, such as anaerobic oxidation of methane. However, on a long term the alteration of silicates, in particular, clay minerals, may be a more efficient mechanism of alkalinity production. Under altered temperature, pressure and porefluid composition at depth, clay minerals may change to thermodynamically more stable states, thereby increasing the alkalinity of the porefluid by partial leaching of Mg-(OH)2 and Ca-(OH)2 (e.g. Wallmann et al., 2008; Mavromatis et al., 2014). This alteration may even be enhanced by a high pCO2. Thus, silicate alteration can be essential for a long-term stabilization of volatile CO2 in the form of bicarbonate or may even induce precipitation of carbonate minerals, but these processes are not fully understood yet. The goal of this study is to simulate the alkalinity effect of silicate alteration under diagenetic conditions and high pCO2 by geochemical modeling. We are using the program PHREEQC (Parkhurst and Appelo, 2013) to generate high rock/fluid ratio characteristics for deep subsurface rock reservoirs. Since we are interested in the long-term evolution of diagenetic processes, over millions of years, we do not consider kinetics but calculate the theoretically possible equilibrium conditions. In a first step we are calculating the saturation state of different clay minerals

  20. [Long-term results of dental health examinations of employees of industrial enterprises with hazardous working conditions].

    PubMed

    Olesova, V N; Uiba, V V; Novozemtseva, T N; Remizova, A A; Olesov, E E

    2017-01-01

    The article analyzes the results of dental examination of employees with hazardous and normal working conditions in Atomenergomash enterprise with various dental care organization regimens and provides clear evidence of the effectiveness of serial attendances care in enterprise dental offices in terms of reduction in the dental treatment needs. Additional funding for departmental dental services was calculated by comparing the real cost of dental treatment and MHI tariffs allowing implementation of proposed dental care program.

  1. [Research on compatibility chemistry of acid-alkaline pair medicines in formulas of traditional Chinese medicine].

    PubMed

    Pei, Miaorong; Duan, Xiujun; Pei, Xiangping; Xuan, Chunsheng; Wang, Xiaoying; Zhao, Lina; Zhang, Shurong; Liu, Bingchen; Wang, Shimin

    2009-08-01

    Compatibility chemistry of acid-alkaline pair medicines in formulas of traditional Chinese medicine (TCM) is an important research field which should merit to pay attention. The ideas and methods in prescription compatibility research on formulas containing alkaline-acid pair medicines were summarized from the aspect of chemical groups of alkaline and acid ingredients; the research results were introduced and analyzed; the research meaning was elaborated; and the expectation of the field was viewed.

  2. Oxygen electrodes for rechargeable alkaline fuel cells

    NASA Astrophysics Data System (ADS)

    Swette, Larry; Giner, Jose

    1987-09-01

    Electrocatalysts and supports for the positive electrode of moderate temperature single unit rechargeable alkaline fuel cells were investigated and developed. The electrocatalysts are defined as the material with a higher activity for the oxygen electrode reaction than the support. Advanced development will require that the materials be prepared in high surface area forms, and may also entail integration of various candidate materials. Eight candidate support materials and seven electrocatalysts were investigated. Of the 8 support, 3 materials meet the preliminary requirements in terms of electrical conductivity and stability. Emphasis is now on preparing in high surface area form and testing under more severe corrosion stress conditions. Of the 7 electrocatalysts prepared and evaluated, at least 5 materials remain as potential candidates. The major emphasis remains on preparation, physical characterization and electrochemical performance testing.

  3. Oxygen electrodes for rechargeable alkaline fuel cells

    NASA Technical Reports Server (NTRS)

    Swette, Larry; Giner, Jose

    1987-01-01

    Electrocatalysts and supports for the positive electrode of moderate temperature single unit rechargeable alkaline fuel cells were investigated and developed. The electrocatalysts are defined as the material with a higher activity for the oxygen electrode reaction than the support. Advanced development will require that the materials be prepared in high surface area forms, and may also entail integration of various candidate materials. Eight candidate support materials and seven electrocatalysts were investigated. Of the 8 support, 3 materials meet the preliminary requirements in terms of electrical conductivity and stability. Emphasis is now on preparing in high surface area form and testing under more severe corrosion stress conditions. Of the 7 electrocatalysts prepared and evaluated, at least 5 materials remain as potential candidates. The major emphasis remains on preparation, physical characterization and electrochemical performance testing.

  4. Dolomite Dissolution in Alkaline Cementious Media

    NASA Astrophysics Data System (ADS)

    Mittermayr, Florian; Klammer, Dietmar; Köhler, Stephan; Dietzel, Martin

    2010-05-01

    Chemical alteration of concrete has gained much attention over the past years as many cases of deterioration due to sulphate attack, thaumasite formation (TSA) or alkali silica reactions (ASR) have been reported in various constructions (Schmidt et al, 2009). Much less is known about the so called alkali carbonate reaction (ACR). It is believed that dolomite aggregates can react with the alkalis from the cement, dissolve and form calcite and brucite (Katayama, 2004). Due to very low solubility of dolomite in alkaline solutions this reaction seems doubtful. In this study we are trying to gain new insides about the conditions that can lead to the dissolution of dolomite in concrete. Therefore we investigated concrete samples from Austrian tunnels that show partially dissolved dolomite aggregates. Petrological analysis such as microprobe, SEM and Raman spectroscopy as well as a hydrochemical analysis of interstitial solutions and ground water and modelling with PhreeqC (Parkhurst and Appelo, 1999) are carried out. In addition a series of batch experiments is set up. Modelling approaches by PhreeqC show a thermodynamically possibility in the alkaline range when additional Ca2+ in solution causes dolomite to become more and more undersaturated as calcite gets supersaturated. Interacting ground water is enriched in Ca2+and saturated with respect to gypsum as marine evaporites are found in situ rocks. Furthermore it is more likely that Portlandite (Ca(OH)2) plays a more important role than Na and K in the cement. Portlandite acts as an additional Ca2+ source and is much more abundant than the alkalies. Some interstitial solutions are dominated mainly by Na+ and SO42- and reach concentrations up to 30 g/l TDS. It is believed that solutions can even reach thenardite saturation as efflorescences are found on the tunnel walls. In consequence dolomite solubility increases with increasing ionic strength. pH > 11 further accelerate the process of dedolomitization by the removal

  5. Diclofenac salts. III. Alkaline and earth alkaline salts.

    PubMed

    Fini, Adamo; Fazio, Giuseppe; Rosetti, Francesca; Angeles Holgado, M; Iruín, Ana; Alvarez-Fuentes, Josefa

    2005-11-01

    Diclofenac salts containing the alkaline and two earth alkaline cations have been prepared and characterized by scanning electron microscopy (SEM) and EDAX spectroscopy; and by thermal and thermogravimetric analysis (TGA): all of them crystallize as hydrate when precipitated from water. The salts dehydrate at room temperature and more easily on heating, but recovery the hydration, when placed in a humid environment. X-ray diffraction spectra suggest that on dehydration new peaks appear on diffractograms and the lattice of the salts partially looses crystallinity. This phenomenon is readily visible in the case of the calcium and magnesium salts, whose thermograms display a crystallization exotherm, before melting or decomposing at temperatures near or above 200 degrees C; these last salts appear to form solvates, when prepared from methanol. The thermogram of each salt shows a complex endotherm of dehydration about 100 degrees C; the calcium salt displays two endotherms, well separated at about 120 and 160 degrees C, which disappear after prolonged heating. Decomposition exotherms, before or soon after the melting, appear below 300 degrees C. The ammonium salt is thermally unstable and, when heated to start dehydration, dissociates and leaves acidic diclofenac.

  6. Stress, temperature, heart rate, and hibernating factors in hamsters. [pathophysiological conditions resulting from exposure to zero gravity

    NASA Technical Reports Server (NTRS)

    Musacchia, X. J.

    1974-01-01

    Pathophysiological conditions resulting from prolonged exposure to zero gravity, cabin constraint, altered ambient environment, whether it be noise, vibrations, high temperatures, or combinations of such factors, are studied in laboratory animals and applied to manned space flight. Results and plans for further study are presented. Specific topics covered include: thermoregulation and its role in reflecting stress and adaptation to the gravity free environment and cabin confinement with its altered circadian forcings; renal function and its measurement in electrolyte distribution and blood flow dynamics; gastronintestinal function and an assessment of altered absorptive capacity in the intestinal mucosa; and catecholamine metabolism in terms of distribution and turnover rates in specific tissues.

  7. Alkaline fuel cell performance investigation

    NASA Technical Reports Server (NTRS)

    Martin, R. E.; Manzo, M. A.

    1988-01-01

    An exploratory experimental fuel cell test program was conducted to investigate the performance characteristics of alkaline laboratory research electrodes. The objective of this work was to establish the effect of temperature, pressure, and concentration upon performance and evaluate candidate cathode configurations having the potential for improved performance. The performance characterization tests provided data to empirically establish the effect of temperature, pressure, and concentration upon performance for cell temperatures up to 300 F and reactant pressures up to 200 psia. Evaluation of five gold alloy cathode catalysts revealed that three doped gold alloys had more that two times the surface areas of reference cathodes and therefore offered the best potential for improved performance.

  8. The Results of Raster-Scan Laser Conditioning Studies on DKDP Triplers Using Nd: YAG and Excimer Lasers

    SciTech Connect

    Runkel, M; Neeb, K; Staggs, M; Auerbach, J; Burnham, A

    2001-11-01

    In this paper we present the results of damage tests performed at 1064 and 355-nm at 8-10 ns on conventional and rapid growth DKDP tripler crystals. The crystals were laser conditioned prior to damage testing by raster scanning using either Nd:YAG (1064 and 355 nm, 8-10ns) or excimer lasers at 248, 308 or 351 nm with pulse durations of approximately 30-47 ns. The results show that it is possible to attain increases in 355-nm damage probability fluences of 2X for excimer conditioning at 248 and 308 nm. However these wavelengths can induce absorption sufficient to induce bulk fracture by thermal shock when impurities such as arsenic, rubidium and sulfur are present in the crystals in sufficient quantity. Tests to evaluate the efficiency of 351-nm conditioning (XeF excimer) show improvements of 2X and that thermal fracture by induced absorption is not a problem. We also discuss our recent discovery that low fluence raster scanning at UV wavelengths leads to 1064-nm damage thresholds of over 100 J/cm{sup 2} (10-ns pulses).

  9. Trypanosoma cruzi alkaline 2-DE: Optimization and application to comparative proteome analysis of flagellate life stages

    PubMed Central

    Magalhães, Adriana D; Charneau, Sébastien; Paba, Jaime; Guércio, Rafael AP; Teixeira, Antonio RL; Santana, Jaime M; Sousa, Marcelo V; Ricart, Carlos AO

    2008-01-01

    Background Trypanosoma cruzi, a flagellate protozoan, is the etiological agent of Chagas disease, a chronic illness that causes irreversible damage to heart and digestive tract in humans. Previous 2-DE analyses of T. cruzi proteome have not focused on basic proteins, possibly because of inherent difficulties for optimizing 2-DE in the alkaline pH range. However, T. cruzi wide pH range 2-DE gels have shown few visible spots in the alkaline region, indicating that the parasite either did not have an appreciable amount of alkaline proteins or that these proteins were underrepresented in the 2-DE gels. Results Different IEF conditions using 6–11 pH gradient strips were tested for separation of T. cruzi alkaline proteins. The optimized methodology described here was performed using anodic "paper bridge" sample loading supplemented by increased concentration of DTT and Triton X-100 on Multiphor II (GE Healthcare) equipment and an electrode pad embedded in DTT- containing solution near the cathode in order to avoid depletion of reducing agent during IEF. Landmark proteins were identified by peptide mass fingerprinting allowing the production of an epimastigote 2-DE map. Most identified proteins corresponded to metabolic enzymes, especially those related to amino acid metabolism. The optimized 2-DE protocol was applied in combination with the "two-in-one gel" method to verify the relative expression of the identified proteins between samples from epimastigote and trypomastigote life stages. Conclusion High resolution 2-DE gels of T. cruzi life forms were achieved using the optimized methodology and a partial epimastigote alkaline 2-DE map was built. Among 700 protein spots detected, 422 were alkaline with a pI above 7.0. The "two-in-one gel" method simplified the comparative analysis between T. cruzi life stages since it minimized variations in spot migration and silver-stained spot volumes. The comparative data were in agreement with biological traits of T. cruzi life

  10. Alkaline assisted thermal oil recovery: Kinetic and displacement studies

    SciTech Connect

    Saneie, S.; Yortsos, Y.C.

    1993-06-01

    This report deals with two major issues of chemical assisted flooding - the interaction of caustic, one of the proposed additives to steam flood, with the reservoir rock, and the displacement of oil by a chemical flood at elevated temperatures. A mathematical model simulating the kinetics of silica dissolution and hydroxyl ion consumption in a typical alkaline flooding environment is first developed. The model is based on the premise that dissolution occurs via hydrolysis of active sites through the formation of an intermediate complex, which is in equilibrium with the silicic acid in solution. Both static (batch) and dynamic (core flood) processes are simulated to examine the sensitivity of caustic consumption and silica dissolution to process parameters, and to determine rates of propagation of pH values. The model presented provides a quantitative description of the quartz-alkali interaction in terms of pH, salinity, ion exchange properties, temperature and contact time, which are of significant importance in the design of soluble silicate flooding processes. The modeling of an adiabatic hot waterflood assisted by the simultaneous injection of a chemical additive is next presented. The model is also applicable to the hot alkaline flooding under conditions of negligible adsorption of the generated anionic surfactant and of hydroxide adsorption being Langmuirian. The theory of generalized simple waves (coherence ) is used to develop solutions for the temperature, concentration, and oil saturation profiles, as well as the oil recovery curves. It is shown that, for Langmuir adsorption kinetics, the chemical resides in the heated region of the reservoir if its injection concentration is below a critical value, and in the unheated region if its concentration exceeds this critical value. Results for a chemical slug injection in a tertiary recovery process indicate recovery performance is maximized when chemical resides in the heated region of the reservior.

  11. Study of point defects in alkaline-earth sulfides

    SciTech Connect

    Pandey, R.; Kunz, A.B.; Vail, J.M.

    1988-11-01

    The results of a computer simulation study of point defects including vacancy, interstitial, and F/sup +/ center in alkaline-earth sulfides are presented. The study is based on ICECAP/HADES simulation procedures and uses empirical interionic potentials obtained from the analysis of macroscopic data for these materials. The results predict the dominance of Schottky disorder and suggest that vacancy migration predominates in alkaline-earth sulfides. Furthermore, the calculated F/sup +/ center absorption energy is in good agreement with the experimental data deduced from the optical stimulated studies in these materials.

  12. In situ alkaline transesterification of cottonseed oil for production of biodiesel and nontoxic cottonseed meal.

    PubMed

    Qian, Junfeng; Wang, Fei; Liu, Sen; Yun, Zhi

    2008-12-01

    The production of fatty acid methyl ester (FAME) by direct in situ alkaline-catalyzed transesterification of the triglycerides (TG) in cottonseeds was examined. The experimental results showed that the amount of cottonseed oil dissolved in methanol was approximately 99% of the total oil and the conversion of this oil could achieve 98% under the following conditions: less than 2% moisture content in cottonseed flours, 0.3-0.335mm particle size, 0.1mol/L NaOH concentration in methanol, 135:1 methanol/oil mole ratio, 40 degrees C reaction temperature and 3h reaction time. Further, the effects of co-solvent petroleum ether and methanol recycling on the cottonseed oil extraction and conversion were also investigated. The use of alkaline methanol as extraction and reaction solvent, which would be useful for extraction oil and gossypol, would reduce the gossypol content in the cottonseed meal. The free and total gossypol contents in the cottonseed meal obtained from in situ alkaline transesterification were far below the FAO standard. And the nontoxic cottonseed meal could be used as animal protein feed resources.

  13. Coordinate responses to alkaline pH stress in budding yeast

    PubMed Central

    Serra-Cardona, Albert; Canadell, David; Ariño, Joaquín

    2015-01-01

    Alkalinization of the medium represents a stress condition for the budding yeast Saccharomyces cerevisiae to which this organism responds with profound remodeling of gene expression. This is the result of the modulation of a substantial number of signaling pathways whose participation in the alkaline response has been elucidated within the last ten years. These regulatory inputs involve not only the conserved Rim101/PacC pathway, but also the calcium-activated phosphatase calcineurin, the Wsc1-Pkc1-Slt2 MAP kinase, the Snf1 and PKA kinases and oxidative stress-response pathways. The uptake of many nutrients is perturbed by alkalinization of the environment and, consequently, an impact on phosphate, iron/copper and glucose homeostatic mechanisms can also be observed. The analysis of available data highlights cases in which diverse signaling pathways are integrated in the gene promoter to shape the appropriate response pattern. Thus, the expression of different genes sharing the same signaling network can be coordinated, allowing functional coupling of their gene products. PMID:28357292

  14. Study on a novel semidry flue gas desulfurization with multifluid alkaline spray generator

    SciTech Connect

    Zhou, Y.G.; Zhang, M.C.; Wang, D.F.; Wang, L.

    2005-11-09

    The advantages and disadvantages of the typical semidry flue gas desulfurization (FGD) processes are analyzed, and a novel semidry FGD process with multifluid alkaline spray generator is first proposed to improve the colliding contact efficiency between sorbent particles and spray water droplets, and to form a large amount of aqueous lime slurry. The experimental results show that the colliding contact efficiency between lime particles and water droplets in the prefix alkaline spray generator may reach about 70%, which is significantly higher than the colliding contact efficiency of 25% in duct sorbent injection. The SO{sub 2} removal efficiency can reach 64.5% when the Ca/S molar ratio is 1.5, the approach to the saturation temperature is 10.3{sup o}C, and the flue gas residence time is 2.25 s. It is higher than that of in-duct sorbent injection under similar conditions, and the sorbent utilization is improved to 43%. Therefore, the FGD process with a prefix alkaline spray generator can greatly improve SO{sub 2} removal efficiency and sorbent utilization and it will be a new, simple and efficient semidry FGD process for industrial application in the future.

  15. Evaluation of the environmental sustainability of farmers' land use decisions in the saline-alkaline areas.

    PubMed

    Yu, Ran; Wang, Jiali

    2015-04-01

    Environmental sustainability has become the focus of agricultural sustainability. This study is aimed at evaluating the environmental sustainability of farmers' land use decisions on saline-alkaline soil in China. Based on empirical and theoretical approaches, the decisions mainly include planting, crop distribution, irrigation, drainage, and fertilization. By surveying 22 administrative villages in typical ecologically fragile saline-alkaline areas of five regions (Shandong, Jiangsu, Jilin, Ningxia, and Xinjiang), the paper builds the evaluation criteria at village level, and obtains a comprehensive index. From the results, irrigation concerns are absent from decision-making. For other decisions, farmers in most villages can appropriately deal with planting, drainage, and fertilization according to the regional natural and social geography conditions. But the comprehensive index of crop distribution in the coastal areas is much stronger than in the northeast and northwest. It is found that the similarities of unsustainability lie in the planting of water-consuming crops, the arbitrary distribution of crops, lack of drainage planning, obsolete water conservancy facilities, excessive use of chemical fertilizers, etc. According to the research, on the one hand, it can guide farmers to rationally make use of saline-alkaline land; on the other hand, it can also provide the basis for government to make differentiated policies in different areas and enhance pertinence in the course of technological extension and application.

  16. Extremely alkaline (pH > 12) ground water hosts diverse microbial community.

    PubMed

    Roadcap, George S; Sanford, Robert A; Jin, Qusheng; Pardinas, José R; Bethke, Craig M

    2006-01-01

    Chemically unusual ground water can provide an environment for novel communities of bacteria to develop. Here, we describe a diverse microbial community that inhabits extremely alkaline (pH > 12) ground water from the Lake Calumet area of Chicago, Illinois, where historic dumping of steel slag has filled in a wetland. Using microbial 16S ribosomal ribonucleic acid gene sequencing and microcosm experiments, we confirmed the presence and growth of a variety of alkaliphilic beta-Proteobacteria, Bacillus, and Clostridium species at pH up to 13.2. Many of the bacterial sequences most closely matched those of other alkaliphiles found in more moderately alkaline water around the world. Oxidation of dihydrogen produced by reaction of water with steel slag is likely a primary energy source to the community. The widespread occurrence of iron-oxidizing bacteria suggests that reduced iron serves as an additional energy source. These results extend upward the known range of pH tolerance for a microbial community by as much as 2 pH units. The community may provide a source of novel microbes and enzymes that can be exploited under alkaline conditions.

  17. Highly Stable, Anion Conductive, Comb-Shaped Copolymers for Alkaline Fuel Cells

    SciTech Connect

    Li, NW; Leng, YJ; Hickner, MA; Wang, CY

    2013-07-10

    To produce an anion-conductive and durable polymer electrolyte for alkaline fuel cell applications, a series of quaternized poly(2,6-dimethyl phenylene oxide)s containing long alkyl side chains pendant to the nitrogen-centered cation were synthesized using a Menshutkin reaction to form comb-shaped structures. The pendant alkyl chains were responsible for the development of highly conductive ionic domains, as confirmed by small-angle X-ray scattering (SAXS). The comb-shaped polymers having one alkyl side chain showed higher hydroxide conductivities than those with benzyltrimethyl ammonium moieties or structures with more than one alkyl side chain per cationic site. The highest conductivity was observed for comb-shaped polymers with benzyldimethylhexadecyl ammonium cations. The chemical stabilities of the comb-shaped membranes were evaluated under severe, accelerated-aging conditions, and degradation was observed by measuring IEC and ion conductivity changes during aging. The comb-shaped membranes retained their high ion conductivity in 1 M NaOH at 80 degrees C for 2000 h. These cationic polymers were employed as ionomers in catalyst layers for alkaline fuel cells. The results indicated that the C-16 alkyl side chain ionomer had a slightly better initial performance, despite its low IEC value, but very poor durability in the fuel cell. In contrast, 90% of the initial performance was retained for the alkaline fuel cell with electrodes containing the C-6 side chain after 60 h of fuel cell operation.

  18. Characterization of Human Bone Alkaline Phosphatase in Pichia Pastoris

    NASA Technical Reports Server (NTRS)

    Malone, Christine C.; Ciszak, Eva; Karr, Laurel J.

    1999-01-01

    A soluble form of human bone alkaline phosphatase has been expressed in a recombinant strain of the methylotrophic yeast Pichia pastoris. We constructed a plasmid containing cDNA encoding for human bone alkaline phosphatase, with the hydrophobic carboxyl terminal portion deleted. Alkaline phosphatase was secreted into the medium to a level of 32mg/L when cultured in shake flasks, and enzyme activity was 12U/mg, as measured by a spectrophotometric assay. By conversion to a fermentation system, a yield of 880mg/L has been achieved with an enzyme activity of 968U/mg. By gel electrophoresis analysis, it appears that greater than 50% of the total protein in the fermentation media is alkaline phosphatase. Although purification procedures are not yet completely optimized, they are expected to include filtration, ion exchange and affinity chromatography. Our presentation will focus on the purification and crystallization results up to the time of the conference. Structural data should provide additional information on the role of alkaline phosphatase in normal bone mineralization and in certain bone mineralization anomalies.

  19. Examination of Single- and Multi-Channel GPR Bridge Deck Condition Assessment Methods with Comparison to Complementary NDE Results

    NASA Astrophysics Data System (ADS)

    Romero, Francisco A.; Manacorda, Guido; Simi, Alessandro; Gucunski, Nenad; Parvardeh, Hooman

    2013-04-01

    A sixteen-channel GPR system which houses both longitudinally- and transversely-polarized, 2.0 GHz antenna elements within a single housing was compared with a single-channel GPR system that was separately using both 1.5GHz and 2.6GHz antennas oriented in the transverse polarization, for the purpose of determining effectiveness of bridge deck condition assessment. The multi-channel system has obvious benefits which include closely-spaced GPR antennas (channels) that provide better lateral resolution, as well as combined data sets from co-linear antennas oriented in both the transverse and longitudinal polarizations, which has benefits for imaging within the deck's internal structure. However, the primary objective was to determine whether the multi-channel system would perform in a similar manner to proven single-channel GPR technology during an attenuation-based GPR condition assessment on an older, partially deteriorated deck in northwestern New Jersey that is annually exposed to freeze-thaw conditions as well as de-icing salts. These assessments were made by focusing on identifying the strongest reflections from the upper mat of transversely-oriented rebars within the deck and comparing reflection strength, or conversely, attenuation of the GPR signal, from each of the 'picked' GPR rebar responses. Coordinates for each of the GPR picks, along with amplitude or attenuation measurements, were gridded and contour-plotted for the purpose of identifying areas identified as either relatively deteriorated or sound. Initially, results were compared for data with no applied correction that takes into account GPR signal attenuation with increasing depth within the concrete deck. Final GPR maps were produced incorporating a depth-correction technique similar to what is described by Barnes, et. al., Romero, et. al, and Gucunski, et. al., a process which has been clearly demonstrated to better correlate GPR results with not only ground truth (cores, sounding) but also with

  20. Analysis of by-product formation and sugar monomerization in sugarcane bagasse pretreated at pilot plant scale: differences between autohydrolysis, alkaline and acid pretreatment.

    PubMed

    van der Pol, Edwin; Bakker, Rob; van Zeeland, Alniek; Sanchez Garcia, David; Punt, Arjen; Eggink, Gerrit

    2015-04-01

    Sugarcane bagasse is an interesting feedstock for the biobased economy since a large fraction is polymerized sugars. Autohydrolysis, alkaline and acid pretreatment conditions combined with enzyme hydrolysis were used on lignocellulose rich bagasse to acquire monomeric. By-products found after pretreatment included acetic, glycolic and coumaric acid in concentrations up to 40, 21 and 2.5 g/kg dry weight bagasse respectively. Alkaline pretreated material contained up to 45 g/kg bagasse DW of sodium. Acid and autohydrolysis pretreatment results in a furan formation of 14 g/kg and 25 g/kg DW bagasse respectively. Enzyme monomerization efficiencies of pretreated solid material after 72 h were 81% for acid pretreatment, 77% for autohydrolysis and 57% for alkaline pretreatment. Solid material was washed with superheated water to decrease the amount of by-products. Washing decreased organic acid, phenol and furan concentrations in solid material by at least 60%, without a major sugar loss.

  1. The performance of charcoal-based radon detection under time-varying radon conditions: Experimental and theoretical results

    SciTech Connect

    Sextro, R.G.; Lee, D.D.

    1988-10-01

    Radon adsorption by charcoal is a widely used technique for measuring indoor radon concentration, particularly when short-term results are desired. There are several different devices available, ranging from permeable envelopes filled with charcoal and open-face charcoal-filled canisters to devices incorporating diffusion limiting features to reduce losses of radon due to desorption. However, the integration characteristics of these samplers are not well understood, particularly under conditions of highly varying radon concentrations. A model for predicting the response of various types of charcoal based detectors to time-variant radon concentrations has been developed; the model predictions compare well with results from chamber experiments. Both the experimental and theoretical results have also been compared with integrated continuous-sampling measurements. The implications of these comparisons for use of charcoal for screening measurements is discussed. 5 refs., 4 figs., 2 tabs.

  2. One year of downwelling spectral radiance measurements from 100 to 1400 cm-1 at Dome Concordia: Results in clear conditions

    NASA Astrophysics Data System (ADS)

    Rizzi, R.; Arosio, C.; Maestri, T.; Palchetti, L.; Bianchini, G.; Del Guasta, M.

    2016-09-01

    The present work examines downwelling radiance spectra measured at the ground during 2013 by a Far Infrared Fourier Transform Spectrometer at Dome C, Antarctica. A tropospheric backscatter and depolarization lidar is also deployed at same site, and a radiosonde system is routinely operative. The measurements allow characterization of the water vapor and clouds infrared properties in Antarctica under all sky conditions. In this paper we specifically discuss cloud detection and the analysis in clear sky condition, required for the discussion of the results obtained in cloudy conditions. First, the paper discusses the procedures adopted for the quality control of spectra acquired automatically. Then it describes the classification procedure used to discriminate spectra measured in clear sky from cloudy conditions. Finally a selection is performed and 66 clear cases, spanning the whole year, are compared to simulations. The computation of layer molecular optical depth is performed with line-by-line techniques and a convolution to simulate the Radiation Explorer in the Far InfraRed-Prototype for Applications and Development (REFIR-PAD) measurements; the downwelling radiance for selected clear cases is computed with a state-of-the-art adding-doubling code. The mean difference over all selected cases between simulated and measured radiance is within experimental error for all the selected microwindows except for the negative residuals found for all microwindows in the range 200 to 400 cm-1, with largest values around 295.1 cm-1. The paper discusses possible reasons for the discrepancy and identifies the incorrect magnitude of the water vapor total absorption coefficient as the cause of such large negative radiance bias below 400 cm-1.

  3. Alkaline and alkaline earth metal phosphate halides and phosphors

    DOEpatents

    Lyons, Robert Joseph; Setlur, Anant Achyut; Cleaver, Robert John

    2012-11-13

    Compounds, phosphor materials and apparatus related to nacaphite family of materials are presented. Potassium and rubidium based nacaphite family compounds and phosphors designed by doping divalent rare earth elements in the sites of alkaline earth metals in the nacaphite material families are descried. An apparatus comprising the phosphors based on the nacaphite family materials are presented herein. The compounds presented is of formula A.sub.2B.sub.1-yR.sub.yPO.sub.4X where the elements A, B, R, X and suffix y are defined such that A is potassium, rubidium, or a combination of potassium and rubidium and B is calcium, strontium, barium, or a combination of any of calcium, strontium and barium. X is fluorine, chlorine, or a combination of fluorine and chlorine, R is europium, samarium, ytterbium, or a combination of any of europium, samarium, and ytterbium, and y ranges from 0 to about 0.1.

  4. Unraveling a Single-Step Simultaneous Two-Electron Transfer Process from Semiconductor to Molecular Catalyst in a CoPy/CdS Hybrid System for Photocatalytic H2 Evolution under Strong Alkaline Conditions.

    PubMed

    Xu, Yuxing; Ye, Yun; Liu, Taifeng; Wang, Xiuli; Zhang, Bingqing; Wang, Mei; Han, Hongxian; Li, Can

    2016-08-31

    Electron transfer processes from semiconductor to molecular catalysts was studied in a model hybrid photocatalytic hydrogen evolution system composed of [Co((III))(dmgH)2PyCl] (CoPy) and CdS under different pH conditions. Thermodynamic and kinetic studies revealed that photocatalytic H2 evolution under high pH conditions (pH 13.5) can only account for the thermodynamically more favorable single-step simultaneous two-electron transfer from photoirradiated CdS to Co(III)Py to produce unavoidable intermediate Co(I)Py, rather than a two-step successive one-electron transfer process. This finding not only provides new insight into the charge transfer processes between semiconductors and molecular catalysts but also opens up a new avenue for the assembly and optimization of semiconductor-molecular catalyst hybrid systems processed through multielectron transfer processes.

  5. Aging, condition monitoring, and loss-of-coolant accident (LOCA) tests of Class 1E electrical cables: Summary of results

    SciTech Connect

    Jacobus, M.J.

    1991-12-01

    This paper summarizes the results of aging, condition monitoring, and accident testing of Class 1E cables used in nuclear power generating stations. Three sets of cables were aged for up to 9 months under simultaneous thermal ({approx_equal} 100{degrees}C) and radiation ({approx_equal}0.10 kGy/hr) conditions. After the aging, the cables were exposed to a simulated accident consisting of high dose rate irradiation ({approx_equal}6 kGy/hr) followed by a high temperature steam exposure. A fourth set of cables, which were unaged, were also exposed to the accident conditions. The cables that were aged for 3 months and then accident tested were subsequently exposed to a high temperature steam fragility test (up to 400{degrees}C), while the cables that were aged for 6 months and then accident tested were subsequently exposed to a 1000-hour submergence test in a chemical solution. The results of the tests indicate that the feasibility of life extension of many popular nuclear power plant cable products is promising and that mechanical measurements (primarily elongation, modulus, and density) were more effective than electrical measurements for monitoring age-related degradation. In the high temperature steam test, ethylene propylene rubber (EPR) cable materials generally survived to higher temperatures than crosslinked polyolefin (XLPO) cable materials. In dielectric testing after the submergence testing, the XLPO materials performed better than the EPR materials. This paper presents some recent experimental data that are not yet available elsewhere and a summary of findings from the entire experimental program.

  6. Aging, condition monitoring, and loss-of-coolant accident (LOCA) tests of Class 1E electrical cables: Summary of results

    SciTech Connect

    Jacobus, M.J.

    1991-01-01

    This paper summarizes the results of aging, condition monitoring, and accident testing of Class 1E cables used in nuclear power generating stations. Three sets of cables were aged for up to 9 months under simultaneous thermal ({approx equal} 100{degrees}C) and radiation ({approx equal}0.10 kGy/hr) conditions. After the aging, the cables were exposed to a simulated accident consisting of high dose rate irradiation ({approx equal}6 kGy/hr) followed by a high temperature steam exposure. A fourth set of cables, which were unaged, were also exposed to the accident conditions. The cables that were aged for 3 months and then accident tested were subsequently exposed to a high temperature steam fragility test (up to 400{degrees}C), while the cables that were aged for 6 months and then accident tested were subsequently exposed to a 1000-hour submergence test in a chemical solution. The results of the tests indicate that the feasibility of life extension of many popular nuclear power plant cable products is promising and that mechanical measurements (primarily elongation, modulus, and density) were more effective than electrical measurements for monitoring age-related degradation. In the high temperature steam test, ethylene propylene rubber (EPR) cable materials generally survived to higher temperatures than crosslinked polyolefin (XLPO) cable materials. In dielectric testing after the submergence testing, the XLPO materials performed better than the EPR materials. This paper presents some recent experimental data that are not yet available elsewhere and a summary of findings from the entire experimental program.

  7. The relationship between geophysical conditions and ELF amplitude in modulated heating experiments at HAARP: Modeling and experimental results

    NASA Astrophysics Data System (ADS)

    Jin, G.; Spasojevic, M.; Cohen, M. B.; Inan, U. S.; Lehtinen, N. G.

    2011-07-01

    Experiments for generating extremely low frequency (ELF) radio waves using modulated HF heating of the auroral ionosphere have been conducted and refined at the High Frequency Active Auroral Research Program (HAARP) facility at Gakona, Alaska. Because this technique is dependent on strength of the naturally generated electrojet current system, the amplitude of the generated ELF changes with geophysical conditions. Past work has shown that electrojet current strength as measured by magnetometers often correlates with generated ELF amplitude, but there are periods of poor or negative correlation. We attempt to use additional diagnostics from a radar, riometer, ionosonde, and magnetometer chain to understand how ionospheric conditions affect ELF generation. We then present the results of a statistical model that shows that ELF amplitude is roughly proportional to magnetometer measurements for a fixed value of riometer absorption and that the proportionality constant decreases as riometer absorption increases. Theoretical simulations of modulated heating are conducted for a variety of ionospheric density profiles to verify that denser profiles result in smaller gains for ELF generation as a function of electrojet current at a given electric field.

  8. The MEXICO project (Model Experiments in Controlled Conditions): The database and first results of data processing and interpretation

    NASA Astrophysics Data System (ADS)

    Snel, H.; Schepers, J. G.; Montgomerie, B.

    2007-07-01

    The Mexico (Model experiments in Controlled Conditions) was a FP5 project, partly financed by European Commission. The main objective was to create a database of detailed aerodynamic and load measurements on a wind turbine model, in a large and high quality wind tunnel, to be used for model validation and improvement. Here model stands for both the extended BEM modelling used in state-of-the-art design and certification software, and CFD modelling of the rotor and near wake flow. For this purpose a three bladed 4.5 m diameter wind tunnel model was built and instrumented. The wind tunnel experiments were carried out in the open section (9.5*9.5 m2) of the Large Scale Facility of the DNW (German-Netherlands) during a six day campaign in December 2006. The conditions for measurements cover three operational tip speed ratios, many blade pitch angles, three yaw misalignment angles and a small number of unsteady cases in the form of pitch ramps and rotor speed ramps. One of the most important feats of the measurement program was the flow field mapping, with stereo PIV techniques. Overall the measurement campaign was very successful. The paper describes the now existing database and discusses a number of highlights from early data processing and interpretation. It should be stressed that all results are first results, no tunnel correction has been performed so far, nor has the necessary checking of data quality.

  9. When can ocean acidification impacts be detected from decadal alkalinity measurements?

    NASA Astrophysics Data System (ADS)

    Carter, B. R.; Frölicher, T. L.; Dunne, J. P.; Rodgers, K. B.; Slater, R. D.; Sarmiento, J. L.

    2016-04-01

    We use a large initial condition suite of simulations (30 runs) with an Earth system model to assess the detectability of biogeochemical impacts of ocean acidification (OA) on the marine alkalinity distribution from decadally repeated hydrographic measurements such as those produced by the Global Ship-Based Hydrographic Investigations Program (GO-SHIP). Detection of these impacts is complicated by alkalinity changes from variability and long-term trends in freshwater and organic matter cycling and ocean circulation. In our ensemble simulation, variability in freshwater cycling generates large changes in alkalinity that obscure the changes of interest and prevent the attribution of observed alkalinity redistribution to OA. These complications from freshwater cycling can be mostly avoided through salinity normalization of alkalinity. With the salinity-normalized alkalinity, modeled OA impacts are broadly detectable in the surface of the subtropical gyres by 2030. Discrepancies between this finding and the finding of an earlier analysis suggest that these estimates are strongly sensitive to the patterns of calcium carbonate export simulated by the model. OA impacts are detectable later in the subpolar and equatorial regions due to slower responses of alkalinity to OA in these regions and greater seasonal equatorial alkalinity variability. OA impacts are detectable later at depth despite lower variability due to smaller rates of change and consistent measurement uncertainty.

  10. Plutonium chemistry under conditions relevant for WIPP performance assessment. Review of experimental results and recommendations for future work

    SciTech Connect

    Oversby, Virginia M.

    2000-09-30

    The Waste Isolation Pilot Plant (WIPP), located at a depth of 650 m in bedded salt at a site approximately 40 km east of Carlsbad, New Mexico, was constructed by the US Department of Energy for the disposal of transuranic wastes arising from defense-related activities. The disposal site is regulated by the US Environmental Protection Agency (EPA). During the process leading to certification of the site for initial emplacement of waste, EEG and their contractors reviewed the DOE Compliance Certification Application (CCA) and raised a number of issues. This report reviews the issues related to the chemistry of plutonium as it will affect the potential for release of radioactivity under WIPP conditions. Emphasis is placed on conditions appropriate for the Human Intrusion scenario(s), since human intrusion has the largest potential for releasing radioactivity to the environment under WIPP conditions. The most significant issues that need to be addressed in relation to plutonium chemistry under WIPP conditions are (1) the effects of heterogeneity in the repository on Pu concentrations in brines introduced under the human intrusion scenario, (2) the redox state of Pu in solution and potential for plutonium in solid phases to have a different redox state from that in the solution phase, (3) the effect of organic ligands on the solubility of Pu in WIPP-relevant brines, and (4) the effects of TRU waste characteristics in determining the solubility of Pu. These issues are reviewed with respect to the treatment they received in the DOE CCA, DOE’s response to EEG’s comments on the CCA, and EPA’s response to those comments as reflected in the final EPA rule that led to the opening of the WIPP. Experimental results obtained in DOE’s Actinide Source-Term Test Program (STTP) during the last two years are reviewed and interpreted in the light of other developments in the field of Pu solution chemistry. This analysis is used as the basis for a conceptual model for Pu

  11. Closed type alkaline storage battery

    SciTech Connect

    Hayama, H.

    1980-06-10

    The alkaline storage battery employs a metallic hat shaped terminal closure which has a piercing needle as well as a puncturable metallic diaphragm positioned below the piercing needle. The needle is fixed by caulking at its peripheral edge portion to a edge of the closure. A comparatively thick and hard metal plate is placed on the inner surface of the diaphragm and is applied to an open portion of a tubular metallic container which has a battery element. A peripheral edge portion of the closure, the diaphragm and the metallic plate are clamped in airtight relationship through a packing between the caulked end portion and an inner annular step portion of the metallic container of the battery. A lead wire extends from one polarity electrode of the battery element and is connected to a central portion of the metallic plate.

  12. Chronic neck and shoulder pain, age, and working conditions: longitudinal results from a large random sample in France

    PubMed Central

    Cassou, B; Derriennic, F; Monfort, C; Norton, J; Touranchet, A

    2002-01-01

    Aims: To analyse the effects of age and occupational factors on both the incidence and the disappearance of chronic neck and shoulder pain after a five year follow up period. Methods: A prospective longitudinal investigation (ESTEV) was carried out in 1990 and 1995 in seven regions of France. A random sample of male and female workers born in 1938, 1943, 1948, and 1953 was selected from the occupational physicians' files. In 1990, 21 378 subjects were interviewed (88% of those contacted), and 87% were interviewed again in 1995. Chronic neck and shoulder pain satisfying specific criteria, and psychosocial working conditions were investigated by a structured self administered questionnaire and a clinical examination. Results: Prevalence (men 7.8%, women 14.8% in 1990) and incidence (men 7.3%, women 12.5% for the period 1990–95) of chronic neck and shoulder pain increased with age, and were more frequent among women than men in every birth cohort. The disappearance rate of chronic neck and shoulder pain decreased with age. Some adverse working conditions (repetitive work under time constraints, awkward work for men, repetitive work for women) contributed to the development of these disorders, independently of age. Psychosocial factors seemed to play a role in both the development and disappearance of chronic neck and shoulder pain. Data did not show specific interactions between age and working conditions. Conclusions: The aging of the workforce appears to contribute to the widespread concern about chronic neck and shoulder pain. A better understanding of work activity regulation of older workers can open up new preventive prospects. PMID:12151610

  13. Alkaline protease production by a strain of marine yeasts

    NASA Astrophysics Data System (ADS)

    Ping, Wang; Zhenming, Chi; Chunling, Ma

    2006-07-01

    Yeast strain 10 with high yield of protease was isolated from sediments of saltern near Qingdao, China. The protease had the highest activity at pH 9.0 and 45°C. The optimal medium for the maximum alkaline protease production of strain 10 was 2.5g soluble starch and 2.0g NaNO3 in 100mL seawater with initial pH 6.0. The optimal cultivation conditions for the maximum protease production were temperature 24.5°C, aeration rate 8.0L min-1 and agitation speed 150r min-1 Under the optimal conditions, 623.1 U mg-1 protein of alkaline protease was reached in the culture within 30h of fermentation.

  14. Response to Long-Term NaHCO3-Derived Alkalinity in Model Lotus japonicus Ecotypes Gifu B-129 and Miyakojima MG-20: Transcriptomic Profiling and Physiological Characterization

    PubMed Central

    Rocco, Rubén; Bordenave, Cesar D.; Escaray, Francisco J.; Antonelli, Cristian; Calzadilla, Pablo; Gárriz, Andrés; Serna, Eva; Carrasco, Pedro; Menendez, Ana B.

    2014-01-01

    The current knowledge regarding transcriptomic changes induced by alkalinity on plants is scarce and limited to studies where plants were subjected to the alkaline salt for periods not longer than 48 h, so there is no information available regarding the regulation of genes involved in the generation of a new homeostatic cellular condition after long-term alkaline stress. Lotus japonicus is a model legume broadly used to study many important physiological processes including biotic interactions and biotic and abiotic stresses. In the present study, we characterized phenotipically the response to alkaline stress of the most widely used L. japonicus ecotypes, Gifu B-129 and MG-20, and analyzed global transcriptome of plants subjected to 10 mM NaHCO3 during 21 days, by using the Affymetrix Lotus japonicus GeneChip®. Plant growth assessment, gas exchange parameters, chlorophyll a fluorescence transient (OJIP) analysis and metal accumulation supported the notion that MG-20 plants displayed a higher tolerance level to alkaline stress than Gifu B-129. Overall, 407 and 459 probe sets were regulated in MG-20 and Gifu B-129, respectively. The number of probe sets differentially expressed in roots was higher than that of shoots, regardless the ecotype. Gifu B-129 and MG-20 also differed in their regulation of genes that could play important roles in the generation of a new Fe/Zn homeostatic cellular condition, synthesis of plant compounds involved in stress response, protein-degradation, damage repair and root senescence, as well as in glycolysis, gluconeogenesis and TCA. In addition, there were differences between both ecotypes in the expression patterns of putative transcription factors that could determine distinct arrangements of flavonoid and isoflavonoid compounds. Our results provided a set of selected, differentially expressed genes deserving further investigation and suggested that the L. japonicus ecotypes could constitute a useful model to search for common and

  15. Alkaline regenerative fuel cell systems for energy storage

    SciTech Connect

    Schubert, F.H.; Reid, M.A.; Martin, R.E.

    1981-01-01

    This paper presents the results of a preliminary design study of a Regenerative Fuel Cell Energy Storage system for application to future low-earth orbit space missions. This high energy density storage system is based on state-of-the-art alkaline electrolyte cell technology and incorporates dedicated fuel cell and electrolysis cell modules. 11 refs.

  16. Surfactant-enhanced alkaline flooding for light oil recovery. Quarterly report, January 1--March 31, 1994

    SciTech Connect

    Wasan, D.T.

    1994-06-01

    The overall objective of this project is to develop a very cost-effective method for formulating a successful surfactant-enhanced alkaline flood by appropriately choosing mixed alkalis which form inexpensive buffers to obtain the desired pH (between 8.5 and 12.0) for ultimate spontaneous emulsification and ultra-low tension. In addition, the novel concept of pH gradient design to optimize flood water conditions will be tested. Last quarter we investigated the phase behavior and the regions where in the middle phase occurs. The optimum phase was found to go through a maximum with pH, sodium concentration and surfactant concentration. The optimum pH is about 12.0 to 13.5, the optimum sodium concentration is about 0.513 mol/liter, and the optimum surfactant concentration is about 0.2%. The effect of surfactant type was also investigated. Petrostep B-105 was found to give the most middle phase production. This quarter, we investigated the contact angle of Long Beach oil, Adena oil, and a model oil on a solid glass surface in contact with an aqueous alkaline solution both with and without added preformed surfactant. The contact angle with Long Beach and Adena oils showed oil-wet conditions, whereas the model oil showed both oil-wet and water-wet conditions depending on the pH of the aqueous phase. The addition of surfactant to the alkaline solution resulted in making the system less oil-wet. Spreading of the oil on the glass surface was observed in all three systems investigated.

  17. Thiomethylation of ketones by sulphide-alkaline solutions and formaldehyde

    SciTech Connect

    Ulendeyeva, A.D.; Samigullin, I.I.; Nasteka, V.I.

    1993-12-31

    An investigation has been made of the thiomethylation of ketones by formaldehyde with mercaptides, sodium sulphide and their mixture. It is possible to regenerate 78-100 rel.% of the sulphide-alkaline solutions under mild conditions (20-50{degrees}C, atmospheric pressure) without feeding a catalyst, with the simultaneous production of ketosulphide concentrate - a less toxic product with properties of practical benefit. 7 refs., 2 figs., 2 tabs.

  18. Detached Eddy Simulation Results for a Space Launch System Configuration at Liftoff Conditions and Comparison with Experiment

    NASA Technical Reports Server (NTRS)

    Krist, Steven E.; Ghaffari, Farhad

    2015-01-01

    Computational simulations for a Space Launch System configuration at liftoff conditions for incidence angles from 0 to 90 degrees were conducted in order to generate integrated force and moment data and longitudinal lineloads. While the integrated force and moment coefficients can be obtained from wind tunnel testing, computational analyses are indispensable in obtaining the extensive amount of surface information required to generate proper lineloads. However, beyond an incidence angle of about 15 degrees, the effects of massive flow separation on the leeward pressure field is not well captured with state of the art Reynolds Averaged Navier-Stokes methods, necessitating the employment of a Detached Eddy Simulation method. Results from these simulations are compared to the liftoff force and moment database and surface pressure data derived from a test in the NASA Langley 14- by 22-Foot Subsonic Wind Tunnel.

  19. Changes to Irradiation Conditions of VVER-1000 Surveillance Specimens Resulting from Fuel Assemblies with Greater Fuel Height

    NASA Astrophysics Data System (ADS)

    Panferov, Pavel; Kochkin, Viacheslav; Erak, Dmitry; Makhotin, Denis; Reshetnikov, Alexandr; Timofeev, Andrey

    2016-02-01

    The goal of the work was to obtain experimental data on the influence of newtype fuel assemblies with higher fuel rods on the irradiation conditions of surveillance specimens installed on the baffe of VVER-1000. For this purpose, two surveillance sets with container assemblies of the same design irradiated in reactors with different fuel assemblies in the core were investigated. Measurements of neutron dosimeters from these sets and retrospective measurements of 54Mn activity accumulated in each irradiated specimen allow a detailed distribution of the fast neutron flux in the containers to be obtained. Neutron calculations have been done using 3D discrete ordinate code KATRIN. On the basis of the obtained results, a change of the lead factor due to newtype fuel assemblies was evaluated for all types of VVER-1000 container assemblies.

  20. Model aerodynamic test results for a refined actuated inlet ejector nozzle at simulated takeoff and cruise conditions

    NASA Technical Reports Server (NTRS)

    Nelson, D. P.

    1983-01-01

    Wind tunnel model tests were conducted to demonstrate the aerodynamic performance improvements of a refined actuated inlet ejector nozzle. Models of approximately one-tenth scale were configured to simulate nozzle operation at takeoff, subsonic cruise, transonic cruise and supersonic cruise. Variations of model components provided a performance evaluation of ejector inlet and exit area, forebody boattail angle and ejector inlet operation in the open and closed mode. Approximately 700 data points were acquired at Mach numbers of 0, 0.36, 0.9, 1.2, and 2.0 for a wide range of nozzle flow conditions. Results show that relative to two ejector nozzles previously tested performance was improved significantly at takeoff and subsonic cruise performance, a C sub f of 0.982, was attained equal to the high performance of the previous tests. The established advanced supersonic transport propulsion study performance goals were met or closely approached at takeoff and supersonic cruise.

  1. [Treatment of depressive patients in private practice--empirical results, health political and social conditions and recommendations].

    PubMed

    Goesmann, Cornelia; Bühren, Astrid; Neuy-Bartmann, Astrid

    2007-09-01

    Although depression and symptoms of depression belong to the most common disorders in private practice, affected patients are not always diagnosed as early as possible in Germany and often not sufficiently treated. In order to improve the care for persons with depression it is necessary that family doctors are prepared to guide these patients with empathy, treat them adequately pharmacologically both in respect to the depression and to all other somatic aspects and to refer them in time to specialists for psychiatry, psychosomatic medicine or psychotherapy. Political and social conditions that have pathogenic effects should be changed and the shortage of psychotherapy needs to be overcome. In future, the integrated care in ambulant and clinical settings will probably be successful, first trials and test setups have shown good results.

  2. Conditional inactivation of Brca1 in the mouse ovarian surface epithelium results in an increase in preneoplastic changes

    SciTech Connect

    Clark-Knowles, Katherine V. . E-mail: kclar075@uottawa.ca; Garson, Kenneth; Jonkers, Jos; Vanderhyden, Barbara C.

    2007-01-01

    Epithelial ovarian cancer (EOC) is thought to arise from the ovarian surface epithelium (OSE); however, the molecular events underlying this transformation are poorly understood. Germline mutations in the BRCA1 tumor suppressor gene result in a significantly increased risk of developing EOC and a large proportion of sporadic EOCs display some sort of BRCA1 dysfunction. Using mice with conditional expression of Brca1, we inactivated Brca1 in the murine OSE and demonstrate that this inactivation results in the development of preneoplastic changes, such as hyperplasia, epithelial invaginations, and inclusion cysts, which arise earlier and are more numerous than in control ovaries. These changes resemble the premalignant lesions that have been reported in human prophylactic oophorectomy specimens from women with BRCA1 germline mutation. We also report that inactivation of Brca1 in primary cultures of murine OSE cells leads to a suppression of proliferation due to increased apoptosis that can be rescued by concomitant inactivation of p53. These observations, along with our finding that these cells display an increased sensitivity to the DNA-damaging agent cisplatin, indicate that loss of function of Brca1 in OSE cells impacts both cellular growth control and DNA-damage repair which results in altered cell behavior manifested as morphological changes in vivo that arise earlier and are more numerous than what can be attributed to ageing.

  3. Evolution of alkaline phosphatases in primates.

    PubMed Central

    Goldstein, D J; Rogers, C; Harris, H

    1982-01-01

    Alkaline phosphatase [orthophosphoric-monoester phosphohydrolase (alkaline optimum), EC 3.1.3.1] in placenta, intestine, liver, kidney, bone, and lung from a variety of primate species has been characterized by quantitative inhibition, thermostability, and immunological studies. Characteristic human placental-type alkaline phosphatase occurs in placentas of great apes (chimpanzee and orangutan) but not in placentas of other primates, including gibbon. It is also present in trace amounts in human lung but not in lung or other tissues of various Old and New World monkeys. However, a distinctive alkaline phosphatase resembling it occurs in substantial amounts in lungs from Old World monkeys but not New World monkeys. It appears that duplication of alkaline phosphatase genes and mutations of genetic elements controlling their tissue expression have occurred relatively recently in mammalian evolution. Images PMID:6950431

  4. Alkaline pH sensor molecules.

    PubMed

    Murayama, Takashi; Maruyama, Ichiro N

    2015-11-01

    Animals can survive only within a narrow pH range. This requires continual monitoring of environmental and body-fluid pH. Although a variety of acidic pH sensor molecules have been reported, alkaline pH sensor function is not well understood. This Review describes neuronal alkaline pH sensors, grouped according to whether they monitor extracellular or intracellular alkaline pH. Extracellular sensors include the receptor-type guanylyl cyclase, the insulin receptor-related receptor, ligand-gated Cl- channels, connexin hemichannels, two-pore-domain K+ channels, and transient receptor potential (TRP) channels. Intracellular sensors include TRP channels and gap junction channels. Identification of molecular mechanisms underlying alkaline pH sensing is crucial for understanding how animals respond to environmental alkaline pH and how body-fluid pH is maintained within a narrow range.

  5. Polyvinyl alcohol membranes as alkaline battery separators

    NASA Technical Reports Server (NTRS)

    Sheibley, D. W.; Gonzalez-Sanabria, O.; Manzo, M. A.

    1982-01-01

    Polyvinly alcohol (PVA) cross-linked with aldehyde reagents yields membranes that demonstrate properties that make them suitable for use as alkaline battery separators. Film properties can be controlled by the choice of cross-linker, cross-link density and the method of cross-linking. Three methods of cross-linking and their effects on film properties are discussed. Film properties can also be modified by using a copolymer of vinyl alcohol and acrylic acid as the base for the separator and cross-linking it similarly to the PVA. Fillers can be incorporated into the films to further modify film properties. Results of separator screening tests and cell tests for several variations of PBA films are discussed.

  6. Inhibition of renal alkaline phosphatase by cimetidine.

    PubMed

    Minai-Tehrani, Dariush; Khodai, Somayeh; Aminnaseri, Somayeh; Minoui, Saeed; Sobhani-Damavadifar, Zahra; Alavi, Sana; Osmani, Raheleh; Ahmadi, Shiva

    2011-08-01

    Alkaline phosphatase (ALP) belongs to hydrolase group of enzymes. It is responsible for removing phosphate groups from many types of molecules, including nucleotides and proteins. Cimetidine (trade name Tagamet) is an antagonist of histamine H2-receptor that inhibits the production of gastric acid. Cimetidine is used for the treatment of gastrointestinal diseases. In this study the inhibitory effect of cimetidine on mouse renal ALP activity was investigated. Our results showed that cimetidine can inhibit ALP by uncompetitive inhibition. In the absence of inhibitor the V(max) and K(m) of the enzyme were found to be 13.7 mmol/mg prot.min and 0.25 mM, respectively. Both the Vmax and Km of the enzyme decreased with increasing cimetidine concentrations (0- 1.2 mM). The Ki and IC(50) of cimetidine were determined to be about 0.5 mM and 0.52 mM, respectively.

  7. Alkaline oxide conversion coatings for aluminum alloys

    SciTech Connect

    Buchheit, R.G.

    1996-02-01

    Three related conversion coating methods are described that are based on film formation which occurs when aluminum alloys are exposed to alkaline Li salt solutions. Representative examples of the processing methods, resulting coating structure, composition and morphology are presented. The corrosion resistance of these coatings to aerated 0.5 M NaCl solution has been evaluated as a function of total processing time using electrochemical impedance spectroscopy (EIS). This evaluation shows that excellent corrosion resistance can be uniformly achieved using no more than 20 minutes of process time for 6061-T6. Using current methods a minimum of 80 minutes of process time is required to get marginally acceptable corrosion resistance for 2024-T3. Longer processing times are required to achieve uniformly good corrosion resistance.

  8. Alkaline pulping of some eucalypts from Sudan.

    PubMed

    Khristova, P; Kordsachia, O; Patt, R; Dafaalla, S

    2006-03-01

    Four eucalypts (Eucalyptus camaldulensis, Eucalyptus microtheca, Eucalyptus tereticornis and Eucalyptus citriodora) grown in Sudan were examined for their suitability for pulping and papermaking with different alkaline methods. Their physical, morphological and chemical characteristics are reported. The pulping trials with E. citriodora and E. tereticornis were carried out using the kraft-AQ, soda-AQ, modified AS/AQ (ASA), ASAM and kraft methods. For the other two species, only the ASAM and the kraft process were applied. ASAM pulping gave the best results in terms of yield, degree of delignification, mechanical and optical pulp properties. The best pulps, obtained in kraft and ASAM cooking of E. citriodora, were bleached to 88% ISO brightness in a totally chlorine free bleaching sequence (OQ1O/PQ2P). The bleached pulps, especially the ASAM pulp, showed good papermaking properties and would be suitable for manufacture of writing and printing grades of paper.

  9. [Impacts of alkaline thermal treatment on characteristics of sludge from sewage treatment plant].

    PubMed

    Yang, Shi-Dong; Chen, Xia; Liu, Cao; Xiao, Ben-Yi

    2015-02-01

    Alkaline thermal treatment is an important pretreatment method for sewage sludge. In this paper, in order to optimize the alkaline thermal treatment conditions for sludge pretreatment, four pretreatment parameters ( sludge concentration, pH, temperature and treatment time) were investigated through orthogonal experiments to determine their effects on the sludge disintegration, sludge concentration and sludge morphology of sewage sludge. The experimental results showed that the significance of the four factors on sludge characteristics was in the order of pH > temperature > treatment time > sludge concentration. Additionally, the optimal conditions of the four factors for the release of soluble chemical oxygen demand (SCOD) of unit sludge and decrease of sludge concentration were as follows: 36.55 g x L(-1), pH 12.45, 175 degrees C and 60 min. While the optimal conditions for the decrease of particle size and fractal dimension were 36.55 g x L(-1), pH 12.5, 175 degrees C and 45 min.

  10. [Effect of calcium on medium alkalinization induced by salicylic acid in Salvia miltiorrhiza suspension cultures].

    PubMed

    Liu, Liancheng; Wang, Cong; Dong, Juan'e; Su, Hui; Zhuo, Zequn; Xue, Yaxin

    2013-07-01

    We studied medium alkalinization in Salvia miltiorrhiza suspension cultures treated with salicylic acid and the effect of Ca2+ in this process through application of calcium channel antagonists (Verapamil, LaCl3, LiCl, 2-APB) and ionophore A23187. The results show that salicylic acid could induce significant medium alkalinization in S. miltiorrhiza culture. Verapamil and LaCl3 or LiCl and 2-APB, two different groups of calcium channel antagonist, significantly inhibited the medium alkalinization induced by salicylic acid. However, the suppression effect of verapamil or LaCl3 on medium alkalinization induced by salicylic acid was higher than that of LiCl or 2-APB. When two types of calcium channel inhibitor (LaCl3 and 2-APB) were used together, the medium alkalinization induced by salicylic acid was completely suppressed and even reduced the pH in medium. On the other hand, A23187 could promote the medium alkalinization. Based on the results above, we speculated that salicylic acid could induce significant medium alkalinization in S. miltiorrhiza culture, depending on the calcium from both extracell and intracell. Moreover, calcium from extracell plays a more dominant role in this process. Reveal of relationship in this research between Ca2+ and medium alkalinization can provide theory evidence for mechanism of the plant secondary metabolism.

  11. Decision making in C. elegans chemotaxis to alkaline pH

    PubMed Central

    Murayama, Takashi; Maruyama, Ichi N

    2013-01-01

    Monitoring of environmental and tissue pH is critical for animal survival. The nematode, Caenorhabditis elegans (C. elegans), is attracted to mildly alkaline pH, but avoids strongly alkaline pH. However, little is known about how the behavioral switching or decision making occurs. Genetic dissection and Ca2+ imaging have previously demonstrated that ASEL and ASH are the major sensory neurons responsible for attraction and repulsion, respectively. Here we report that unlike C. elegans wild type, mutants deficient in ASEL or ASH were repelled by mildly alkaline pH, or were attracted to strongly alkaline pH, respectively. These results suggest that signals through ASEL and ASH compete to determine the animal’s alkaline-pH chemotaxis. Furthermore, mutants with 2 ASEL neurons were more efficiently attracted to mildly alkaline pH than the wild type with a single ASEL neuron, indicating that higher activity of ASEL induces stronger attraction to mildly alkaline pH. This stronger attraction was overridden by normal activity of ASH, suggesting that ASH-mediated avoidance dominates ASEL-mediated attraction. Thus, C. elegans chemotactic behaviors to alkaline pH seems to be determined by signal strengths from the sensory neurons ASEL and ASH, and the behavior decision making seems to be the result of competition between the 2 sensory neurons. PMID:24563708

  12. Extracellular Alkalinization as a Defense Response in Potato Cells

    PubMed Central

    Moroz, Natalia; Fritch, Karen R.; Marcec, Matthew J.; Tripathi, Diwaker; Smertenko, Andrei; Tanaka, Kiwamu

    2017-01-01

    A quantitative and robust bioassay to assess plant defense response is important for studies of disease resistance and also for the early identification of disease during pre- or non-symptomatic phases. An increase in extracellular pH is known to be an early defense response in plants. In this study, we demonstrate extracellular alkalinization as a defense response in potatoes. Using potato suspension cell cultures, we observed an alkalinization response against various pathogen- and plant-derived elicitors in a dose- and time-dependent manner. We also assessed the defense response against a variety of potato pathogens, such as protists (Phytophthora infestans and Spongospora subterranea) and fungi (Verticillium dahliae and Colletotrichum coccodes). Our results show that extracellular pH increases within 30 min in proportion to the number of pathogen spores added. Consistently with the alkalinization effect, the higher transcription level of several defense-related genes and production of reactive oxygen species was observed. Our results demonstrate that the alkalinization response is an effective marker to study early stages of defense response in potatoes. PMID:28174578

  13. Extracellular Alkalinization as a Defense Response in Potato Cells.

    PubMed

    Moroz, Natalia; Fritch, Karen R; Marcec, Matthew J; Tripathi, Diwaker; Smertenko, Andrei; Tanaka, Kiwamu

    2017-01-01

    A quantitative and robust bioassay to assess plant defense response is important for studies of disease resistance and also for the early identification of disease during pre- or non-symptomatic phases. An increase in extracellular pH is known to be an early defense response in plants. In this study, we demonstrate extracellular alkalinization as a defense response in potatoes. Using potato suspension cell cultures, we observed an alkalinization response against various pathogen- and plant-derived elicitors in a dose- and time-dependent manner. We also assessed the defense response against a variety of potato pathogens, such as protists (Phytophthora infestans and Spongospora subterranea) and fungi (Verticillium dahliae and Colletotrichum coccodes). Our results show that extracellular pH increases within 30 min in proportion to the number of pathogen spores added. Consistently with the alkalinization effect, the higher transcription level of several defense-related genes and production of reactive oxygen species was observed. Our results demonstrate that the alkalinization response is an effective marker to study early stages of defense response in potatoes.

  14. Ocean alkalinity and the Cretaceous/Tertiary boundary

    NASA Technical Reports Server (NTRS)

    Caldeira, K. G.; Rampino, Michael R.

    1988-01-01

    A biogeochemical cycle model resolving ocean carbon and alkalinity content is applied to the Maestrichtian and Danian. The model computes oceanic concentrations and distributions of Ca(2+), Mg(2+), and Sigma-CO2. From these values an atmospheric pCO2 value is calculated, which is used to estimate rates of terrestrial weathering of calcite, dolomite, and calcium and magnesium silicates. Metamorphism of carbonate rocks and the subsequent outgassing of CO2 to the atmosphere are parameterized in terms of carbonate rock reservoir sizes, total land area, and a measure of overall tectonic activity, the sea-floor generation rate. The ocean carbon reservoir computed by the model is used with Deep Sea Drilling Project (DSDP) C-13 data to estimate organic detrital fluxes under a variety of ocean mixing rate assumptions. Using Redfield ratios, the biogenic detrital flux estimate is used to partition the ocean carbon and alkalinity reservoirs between the mixed layer and deep ocean. The calcite flux estimate and carbonate ion concentrations are used to determine the rate of biologically mediated CaCO3 titration. Oceanic productivity was severely limited for approximately 500 kyr following the K/T boundary resulting in significant increases in total ocean alkalinity. As productivity returned to the ocean, excess carbon and alkalinity was removed from the ocean as CaCO3. Model runs indicate that this resulted in a transient imbalance in the other direction. Ocean chemistry returned to near-equilibrium by about 64 mybp.

  15. Exploratory results from a new rotary shear designed to reproduce the extreme deformation conditions of crustal earthquakes

    NASA Astrophysics Data System (ADS)

    Di Toro, G.; Nielsen, S. B.; Spagnuolo, E.; Smith, S.; Violay, M. E.; Niemeijer, A. R.; Di Felice, F.; Di Stefano, G.; Romeo, G.; Scarlato, P.

    2011-12-01

    A challenging goal in experimental rock deformation is to reproduce the extreme deformation conditions typical of coseismic slip in crustal earthquakes: large slip (up to 50 m), slip rates (0.1-10 m/s), accelerations (> 10 m/s2) and normal stress (> 50 MPa). Moreover, fault zones usually contain non-cohesive rocks (gouges) and fluids. The integration of all these deformation conditions is such a technical challenge that there is currently no apparatus in the world that can reproduce seismic slip. Yet, the determination of rock friction at seismic slip rates remains one of the main unknowns in earthquake physics, as it cannot be determined (or very approximately) by seismic wave inversion analysis. In the last thirty years, rotary shear apparatus were designed that combine large normal stresses and slip but low slip rates (high-pressure rotary shears first designed by Tullis) or low normal stresses but large slip rates and slip (rotary shears first designed by Shimamoto). Here we present the results of experiments using a newly-constructed Slow to HIgh Velocity Apparatus (SHIVA), installed at INGV in Rome, which extends the combination of normal stress, slip and slip rate achieved by previous apparatus and reproduces the conditions likely to occur during an earthquake in the shallow crust. SHIVA uses two brushless engines (max power 300 kW, max torque 930 Nm) and an air actuator (thrust 5 tons) in a rotary shear configuration (nominally infinite displacement) to slide hollow rock cylinders (30/50 mm int./ext. diameter) at slip rates ranging from 10 micron/s up to 6.5 m/s, accelerations up to 80 m/s2 and normal stresses up to 50 MPa. SHIVA can also perform experiments in which the torque on the sample (rather than the slip rate) is progressively increased until spontaneous failure occurs: this experimental capability should better reproduce natural conditions. The apparatus is equipped with a sample chamber to carry out experiments in the presence of fluids (up to 15

  16. Reduced-intensity conditioning with combined haploidentical and cord blood transplantation results in rapid engraftment, low GVHD, and durable remissions

    PubMed Central

    Liu, Hongtao; Rich, Elizabeth S.; Godley, Lucy; Odenike, Olatoyosi; Joseph, Loren; Marino, Susana; Kline, Justin; Nguyen, Vu; Cunningham, John; Larson, Richard A.; del Cerro, Paula; Schroeder, Linda; Pape, Lisa; Stock, Wendy; Wickrema, Amittha; Artz, Andrew S.

    2011-01-01

    We conducted a 45 patient prospective study of reduced-intensity conditioning (RIC) and transplantation of unrelated umbilical cord blood (UCB) and CD34+ stem cells from a haploidentical family member. Median age was 50 years; weight was 80 kg. Fifty-eight percent had active disease. Neutrophil engraftment occurred at 11 days (interquartile range [IQR], 9-15) and platelet engraftment at 19 days (IQR, 15-33). In the majority of patients, early haploidentical engraftment was replaced by durable engraftment of UCB by 100 days, with regular persistence of minor host and/or haplo-hematopoiesis. Percentage of haplochimerism at day 100 correlated with the haplo-CD34 dose (P = .003). Cumulative incidence of acute GVHD (aGVHD) was 25% and chronic GVHD (cGVHD) was 5%. Actuarial survival at 1 year was 55%, progression-free survival (PFS) was 42%, nonrelapse mortality (NRM) was 28%, and relapse was 30%. RIC and haplo-cord transplantation results in fast engraftment of neutrophils and platelets, low incidences of aGVHD and cGVHD, low frequency of delayed opportunistic infections, reduced transfusion requirements, shortened length of hospital stay, and promising long-term outcomes. UCB cell dose had no impact on time to hematopoietic recovery. Therefore, UCB selection can prioritize matching, and better matched donors can be identified rapidly for most patients. This study is registered at http://clinicaltrials.gov as NCI clinical trial no. NCT00943800. PMID:21976674

  17. Seasonal differences in the subjective assessment of outdoor thermal conditions and the impact of analysis techniques on the obtained results

    NASA Astrophysics Data System (ADS)

    Kántor, Noémi; Kovács, Attila; Takács, Ágnes

    2016-11-01

    Wide research attention has been paid in the last two decades to the thermal comfort conditions of different outdoor and semi-outdoor urban spaces. Field studies were conducted in a wide range of geographical regions in order to investigate the relationship between the thermal sensation of people and thermal comfort indices. Researchers found that the original threshold values of these indices did not describe precisely the actual thermal sensation patterns of subjects, and they reported neutral temperatures that vary among nations and with time of the year. For that reason, thresholds of some objective indices were rescaled and new thermal comfort categories were defined. This research investigates the outdoor thermal perception patterns of Hungarians regarding the Physiologically Equivalent Temperature ( PET) index, based on more than 5800 questionnaires. The surveys were conducted in the city of Szeged on 78 days in spring, summer, and autumn. Various, frequently applied analysis approaches (simple descriptive technique, regression analysis, and probit models) were adopted to reveal seasonal differences in the thermal assessment of people. Thermal sensitivity and neutral temperatures were found to be significantly different, especially between summer and the two transient seasons. Challenges of international comparison are also emphasized, since the results prove that neutral temperatures obtained through different analysis techniques may be considerably different. The outcomes of this study underline the importance of the development of standard measurement and analysis methodologies in order to make future studies comprehensible, hereby facilitating the broadening of the common scientific knowledge about outdoor thermal comfort.

  18. Confidence in Airline Performance in Difficult Market Conditions: An Analysis of JetBlue's Financial Market Results

    NASA Technical Reports Server (NTRS)

    Flouris, Triant; Walker, Thomas

    2005-01-01

    This paper examines the stock market s reaction to JetBlue s Initial Public Offering (1PO) and subsequent price movements of the stock. In particular, w e examine whether the euphoria surrounding JetBlue s IPO carried over to other firms in the sector by testing whether the shares of JetBlue s competitors showed a significant price reaction to JetBlue s IPO. JetBlue's IPO took place just a few months following September 11, 2001. These events resulted in dramatic changes in the airline industry and had significant implications on the economic gains of airlines. We examine JetBlue s accounting and stock performance and compare it to the relative performance of Southwest Airlines (SWA), a representative of the loa-cost carrier group. In addition, we compare both JetBlue's and SWA's financial condition and the relative performance of their stock to two mainline U S. carriers, Continental and Northwest. representatives of the conventional-cost carrier group. We analyze whether there are any performance differences among the low-cost carriers and between low-cost carriers and conventional-cost carriers. In particular, we examine whether low-cost carriers were able to sustain the economic impacts of 9/11 better than the conventional-cost carriers.

  19. Gender differences in Generalized Anxiety Disorder: Results from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC)

    PubMed Central

    Vesga-López, Oriana; Schneier, Franklin; Wang, Samuel; Heimberg, Richard; Liu, Shang-Min; Hasin, Deborah S.; Blanco, Carlos

    2016-01-01

    Objective To assess gender differences in the epidemiology, comorbidity and treatment-seeking patterns of DSM-IV Generalized Anxiety Disorder (GAD) in the United States. Method Data were derived from the 2001–2002 National Epidemiologic Survey on Alcohol and Related Conditions (NESARC), a large cross-sectional survey of a representative sample (N=43,093) of the U.S. population. Results The lifetime and twelve-month male:female prevalence ratios of DSM-IV GAD were 1:1.9 and 1:2.2, respectively. Men with GAD had significantly higher rates of comorbid alcohol and drug use disorders, nicotine dependence, and antisocial personality disorder. Women with GAD had significantly higher rates of comorbid mood disorders (except bipolar disorder) and anxiety disorders (except social anxiety disorder). Men with GAD reported greater use of alcohol and non-prescription medications to help relieve GAD symptoms. GAD in women was associated with higher family history of depression. Disability associated with GAD was greater in women than in men. Rates of treatment-seeking for DSM-IV GAD were low for both genders, but particularly low among men. Conclusion There are significant gender differences in the prevalence, comorbidity pattern, sociodemographic and clinical correlates, course, and treatment-seeking rates of persons with DSM-IV GAD. Increased recognition and treatment of GAD, particularly among men, could lead to a substantial reductions in the societal and personal burden and improve the quality of life of those afflicted with this disorder. PMID:19192444

  20. Comorbidity of Generalized Anxiety Disorder and Substance Use Disorders: Results from the National Epidemiologic Survey on Alcohol and Related Conditions

    PubMed Central

    Alegría, Analucía A.; Hasin, Deborah S.; Nunes, Edward V.; Liu, Shang-Min; Davies, Carrie; Grant, Bridget F.; Blanco, Carlos

    2009-01-01

    Objective Prior research has consistently documented a strong association between generalized anxiety disorder (GAD) and substance use disorder (SUD). GAD and SUD comorbidity (GAD-SUD) represents clinical challenges as the patients’ symptoms are often more severe and are frequently prolonged making their management more complex when compared with individuals with GAD only. The purpose of this study was to examine whether individuals with GAD-SUD differ meaningfully from individuals with GAD and no SUD comorbidity (GAD-NSUD) in terms of demographic characteristics, risk factors, psychiatric comorbidity and clinical correlates. Methods Data were derived from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) (N=43,093). Diagnoses were made using the Alcohol Use Disorder and Associated Disabilities Interview Schedule-DSM-IV version. Results We found that the lifetime prevalence rate of GAD-SUD is about 2.04% while that of GAD-NSUD is of 2.10%. Individuals with GAD-SUD showed higher psychiatric comorbidity rates than those with GAD-NSUD. Treatment seeking rates for GAD are equally low in GAD-SUD and GAD-NSUD. Both groups were as likely to receive pharmacological treatment for anxiety. Conclusion The findings of our study indicate that individuals of GAD-SUD constitutes half of the lifetime prevalence of GAD and that GAD-SUD is associated with high overall vulnerability for additional psychopathology, particularly in the externalizing spectrum, higher disability and higher use of alcohol and drugs to relieve anxiety symptoms. PMID:20923623

  1. [Living conditions of women 50plus in Europe - results of a secondary analysis in twelve Western European countries].

    PubMed

    Stiehr, K; Spindler, M

    2006-02-01

    Within the framework of the research project MERI, we analyzed in twelve Western European countries which kind of studies and official statistics are available on the situation of women 50plus and how their situation is described by these data. On the one hand, thematic and country-specific knowledge and knowledge gaps were identified. Generally speaking the topics health and social integration are the focus of the examined studies. Detailed data were also found on issues relating to work and the material situation. Knowledge gaps are to be found with regard to the topics interest representation, education and violence/abuse. There are clear country-specific differences in the data. Partly there is a North-South divide with regard to the availability and the quality of data. On the other hand, characteristics of the living conditions of women 50plus were identified. Women 50plus are a very heterogeneous group which strongly differs among others with regard to social background, disability, illness, region and migration. At the same time there are, however, clear common problems in the examined areas health, social integration, education, work, material situation, interest representation and violence/abuse. From the research result recommendations are derived for future studies and the improvement of official statistics.

  2. Association among Working Hours, Occupational Stress, and Presenteeism among Wage Workers: Results from the Second Korean Working Conditions Survey

    PubMed Central

    2014-01-01

    Objectives The purpose of the present study was to identify the association between presenteeism and long working hours, shiftwork, and occupational stress using representative national survey data on Korean workers. Methods We analyzed data from the second Korean Working Conditions Survey (KWCS), which was conducted in 2010, in which a total of 6,220 wage workers were analyzed. The study population included the economically active population aged above 15 years, and living in the Republic of Korea. We used the chi-squared test and multivariate logistic regression to test the statistical association between presenteeism and working hours, shiftwork, and occupational stress. Results Approximately 19% of the workers experienced presenteeism during the previous 12 months. Women had higher rates of presenteeism than men. We found a statistically significant dose–response relationship between working hours and presenteeism. Shift workers had a slightly higher rate of presenteeism than non-shift workers, but the difference was not statistically significant. Occupational stress, such as high job demand, lack of rewards, and inadequate social support, had a significant association with presenteeism. Conclusions The present study suggests that long working hours and occupational stress are significantly related to presenteeism. PMID:24661575

  3. Shelf life extension and antioxidant activity of 'Hayward' kiwi fruit as a result of prestorage conditioning and 1-methylcyclopropene treatment.

    PubMed

    Park, Yong Seo; Im, Myeng He; Gorinstein, Shela

    2015-05-01

    Kiwi fruits (Actinidia deliciosa C.F. Liang et A.R. Ferguson) were treated by prestorage conditioning (20 °C for 2 days), 1-methylcyclopropene (1-MCP, 1 ppm for 16 h) and conditioning plus 1-MCP. After the treatment the fruits were immediately stored at 0 °C during 24 weeks. Flesh firmness gradually decreased with storage time and the rate of its loss was lower in 1-MCP and conditioning plus 1-MCP treatments than those of control or conditioning. However, SSC, acidity and pH did not change among treatments. Starch content decreased during the storage time regardless of treatments. Oppositely the amount of reducing sugars increased at the same duration of the treatments. Rate and incidence of fruit decay was the lowest in fruit treated with conditioning plus 1-MCP treatment. Fruit decay mainly caused pathogen Botrytis cinerea and its rate significantly decreased with conditioning plus 1-MCP treatment. Ethylene and respiration abruptly increased after 8 weeks of storage, but their contents were lower in 1-MCP and conditioning plus 1-MCP. Total soluble phenolics, flavonoids, and total antioxidant capacities were much higher than in other treatments. Kiwi fruits treated with conditioning plus 1-MCP extended the shelf life by reducing the rate of fruit decay and softening during the storage. The bioactive compounds and total antioxidant status of fruits increased during the treatment.

  4. Spatial Patterns of Alkaline Phosphatase Expression within Bacterial Colonies and Biofilms in Response to Phosphate Starvation

    PubMed Central

    Huang, Ching-Tsan; Xu, Karen D.; McFeters, Gordon A.; Stewart, Philip S.

    1998-01-01

    The expression of alkaline phosphatase in response to phosphate starvation was shown to be spatially and temporally heterogeneous in bacterial biofilms and colonies. A commercial alkaline phosphatase substrate that generates a fluorescent, insoluble product was used in conjunction with frozen sectioning techniques to visualize spatial patterns of enzyme expression in both Klebsiella pneumoniae and Pseudomonas aeruginosa biofilms. Some of the expression patterns observed revealed alkaline phosphatase activity at the boundary of the biofilm opposite the place where the staining substrate was delivered, indicating that the enzyme substrate penetrated the biofilm fully. Alkaline phosphatase accumulated linearly with time in K. pneumoniae colonies transferred from high-phosphate medium to low-phosphate medium up to specific activities of 50 μmol per min per mg of protein after 24 h. In K. pneumoniae biofilms and colonies, alkaline phosphatase was initially expressed in the region of the biofilm immediately adjacent to the carbon and energy source (glucose). In time, the region of alkaline phosphatase expression expanded inward until it spanned most, but not all, of the biofilm or colony depth. In contrast, expression of alkaline phosphatase in P. aeruginosa biofilms occurred in a thin, sharply delineated band at the biofilm-bulk fluid interface. In this case, the band of activity never occupied more than approximately one-sixth of the biofilm. These results are consistent with the working hypothesis that alkaline phosphatase expression patterns are primarily controlled by the local availability of either the carbon and energy source or the electron acceptor. PMID:9546188

  5. Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory : evaluation of alkaline persulfate digestion as an alternative to Kjeldahl digestion for determination of total and dissolved nitrogen and phosphorus in water

    USGS Publications Warehouse

    Patton, Charles J.; Kryskalla, Jennifer R.

    2003-01-01

    Alkaline persulfate digestion was evaluated and validated as a more sensitive, accurate, and less toxic alternative to Kjeldahl digestion for routine determination of nitrogen and phosphorus in surface- and ground-water samples in a large-scale and geographically diverse study conducted by U.S. Geological Survey (USGS) between October 1, 2001, and September 30, 2002. Data for this study were obtained from about 2,100 surface- and ground-water samples that were analyzed for Kjeldahl nitrogen and Kjeldahl phosphorus in the course of routine operations at the USGS National Water Quality Laboratory (NWQL). These samples were analyzed independently for total nitrogen and total phosphorus using an alkaline persulfate digestion method developed by the NWQL Methods Research and Development Program. About half of these samples were collected during nominally high-flow (April-June) conditions and the other half were collected during nominally low-flow (August-September) conditions. The number of filtered and whole-water samples analyzed from each flow regime was about equal.By operational definition, Kjeldahl nitrogen (ammonium + organic nitrogen) and alkaline persulfate digestion total nitrogen (ammonium + nitrite + nitrate + organic nitrogen) are not equivalent. It was necessary, therefore, to reconcile this operational difference by subtracting nitrate + nitrite concentra-tions from alkaline persulfate dissolved and total nitrogen concentrations prior to graphical and statistical comparisons with dissolved and total Kjeldahl nitrogen concentrations. On the basis of two-population paired t-test statistics, the means of all nitrate-corrected alkaline persulfate nitrogen and Kjeldahl nitrogen concentrations (2,066 paired results) were significantly different from zero at the p = 0.05 level. Statistically, the means of Kjeldahl nitrogen concentrations were greater than those of nitrate-corrected alkaline persulfate nitrogen concentrations. Experimental evidence strongly

  6. Depression in bipolar disorder versus major depressive disorder: results from the National Epidemiologic Survey on Alcohol and Related Conditions

    PubMed Central

    Moreno, Carmen; Hasin, Deborah S.; Arango, Celso; Oquendo, Maria A.; Vieta, Eduard; Liu, Shangmin; Grant, Bridget F.; Blanco, Carlos

    2012-01-01

    Objectives To compare the clinical features and course of major depressive episodes (MDE) occurring in subjects with bipolar I disorder (BD-I), bipolar II disorder (BD-II), and major depressive disorder (MDD). Methods Data were drawn from the National Epidemiologic Survey on Alcohol and Related Conditions (2001–2002), a nationally representative face-to-face survey of more than 43,000 adults in the United States, including 5,695 subjects with lifetime MDD, 935 with BD-I and lifetime MDE, and 494 with BD-II and lifetime MDE. Differences on sociodemographic characteristics and clinical features, course, and treatment patterns of MDE were analyzed. Results Most depressive symptoms, family psychiatric history, anxiety disorders, alcohol and drug use disorders, and personality disorders were more frequent—and number of depressive symptoms per MDE were higher—among subjects with BD-I, followed by BD-II, and MDD. BD-I individuals experienced a higher number of lifetime MDE, had the worst quality of life, and received significantly more treatment for MDE than BD-II and MDD subjects. Individuals with BD-I and BD-II experienced their first mood episode about 10 years earlier than those with MDD (21.2, 20.5, and 30.4 years, respectively). Conclusions Our results support the existence of a spectrum of severity of MDE, with highest severity for BD-I, followed by BD-II and MDD, suggesting the utility of dimensional assessments in current categorical classifications. PMID:22548900

  7. Conditional TNF-α Overexpression in the Tooth and Alveolar Bone Results in Painful Pulpitis and Osteitis

    PubMed Central

    Hall, B.E.; Zhang, L.; Sun, Z.J.; Utreras, E.; Prochazkova, M.; Cho, A.; Terse, A.; Arany, P.; Dolan, J.C.; Schmidt, B.L.; Kulkarni, A.B.

    2016-01-01

    Tumor necrosis factor–α (TNF-α) is a proalgesic cytokine that is commonly expressed following tissue injury. TNF-α expression not only promotes inflammation but can also lead to pain hypersensitivity in nociceptors. With the established link between TNF-α and inflammatory pain, we identified its increased expression in the teeth of patients affected with caries and pulpitis. We generated a transgenic mouse model (TNF-αglo) that could be used to conditionally overexpress TNF-α. These mice were bred with a dentin matrix protein 1 (DMP1)–Cre line for overexpression of TNF-α in both the tooth pulp and bone to study oral pain that would result from subsequent development of pulpitis and bone loss. The resulting DMP1/TNF-αglo mice show inflammation in the tooth pulp that resembles pulpitis while also displaying periodontal bone loss. Inflammatory infiltrates and enlarged blood vessels were observed in the tooth pulp. Pulpitis and osteitis affected the nociceptive neurons innervating the orofacial region by causing increased expression of inflammatory cytokines within the trigeminal ganglia. With this new mouse model morphologically mimicking pulpitis and osteitis, we tested it for signs of oral pain with an oral function assay (dolognawmeter). This assay/device records the time required by a mouse to complete a discrete gnawing task. The duration of gnawing required by the DMP1/TNF-αglo mice to complete the task was greater than that for the controls; extended gnaw time in a dolognawmeter indicates reduced orofacial function. With the DMP1/TNF-αglo mice, we have shown that TNF-α expression alone can produce inflammation similar to pulpitis and osteitis and that this mouse model can be used to study dental inflammatory pain. PMID:26503912

  8. Purification and characterization of a novel alkaline α-L-rhamnosidase produced by Acrostalagmus luteo albus.

    PubMed

    Rojas, Natalia Lorena; Voget, Claudio Enrique; Hours, Roque Alberto; Cavalitto, Sebastián Fernando

    2011-09-01

    Rhamnosidases are enzymes that catalyze the hydrolysis of terminal nonreducing L-rhamnose for the bioconversion of natural or synthetic rhamnosides. They are of great significance in the current biotechnological area, with applications in food and pharmaceutical industrial processes. In this study we isolated and characterized a novel alkaline rhamnosidase from Acrostalagmus luteo albus, an alkali-tolerant soil fungus from Argentina. We also present an efficient, simple, and inexpensive method for purifying the A. luteo albus rhamnosidase and describe the characteristics of the purified enzyme. In the presence of rhamnose as the sole carbon source, this fungus produces a rhamnosidase with a molecular weight of 109 kDa and a pI value of 4.6, as determined by SDS-PAGE and analytical isoelectric focusing, respectively. This enzyme was purified to homogeneity by chromatographic and electrophoretic techniques. Using p-nitrofenil-α-L-rhamnopiranoside as substrate, the enzyme activity showed pH and temperature optima of 8.0 and 55°C, respectively. The enzyme exhibited Michaelis-Menten kinetics, with K (M) and V (max) values of 3.38 mmol l(-1) and 68.5 mmol l(-1) min(-1), respectively. Neither divalent cations such as Ca(2+), Mg(2+), Mn(2+), and Co(2+) nor reducing agents such as β-mercaptoethanol and dithiothreitol showed any effect on enzyme activity, whereas this activity was completely inhibited by Zn(2+) at a concentration of 0.2 mM. This enzyme showed the capacity to hydrolyze some natural rhamnoglucosides such as hesperidin, naringin and quercitrin under alkaline conditions. Based on these results, and mainly due to the high activity of the A. luteo albus rhamnosidase under alkaline conditions, this enzyme should be considered a potential new biocatalyst for industrial applications.

  9. Coral calcification under environmental change: a direct comparison of the alkalinity anomaly and buoyant weight techniques

    NASA Astrophysics Data System (ADS)

    Schoepf, Verena; Hu, Xinping; Holcomb, Michael; Cai, Wei-Jun; Li, Qian; Wang, Yongchen; Xu, Hui; Warner, Mark E.; Melman, Todd F.; Hoadley, Kenneth D.; Pettay, D. Tye; Matsui, Yohei; Baumann, Justin H.; Grottoli, Andréa G.

    2017-03-01

    Two primary methods—the buoyant weight (BW) and alkalinity anomaly (AA) techniques—are currently used to quantify net calcification rates ( G) in scleractinian corals. However, it remains unclear whether they are directly comparable since the few method comparisons conducted to date have produced inconsistent results. Further, such a comparison has not been made for tropical corals. We directly compared G BW and G AA in four tropical and one temperate coral species cultured under various pCO2, temperature, and nutrient conditions. A range of protocols for conducting alkalinity depletion incubations was assessed. For the tropical corals, open-top incubations with manual stirring produced G AA that were highly correlated with and not significantly different from G BW. Similarly, G AA of the temperate coral was not significantly different from G BW when incubations provided water motion using a pump, but were significantly lower than G BW by 16% when water motion was primarily created by aeration. This shows that the two techniques can produce comparable calcification rates in corals but only when alkalinity depletion incubations are conducted under specific conditions. General recommendations for incubation protocols are made, especially regarding adequate water motion and incubation times. Further, the re-analysis of published data highlights the importance of using appropriate regression statistics when both variables are random and measured with error. Overall, we recommend the AA technique for investigations of community and short-term day versus night calcification, and the BW technique to measure organism calcification rates integrated over longer timescales due to practical limitations of both methods. Our findings will facilitate the direct comparison of studies measuring coral calcification using either method and thus have important implications for the fields of ocean acidification research and coral biology in general.

  10. Process for extracting technetium from alkaline solutions

    DOEpatents

    Moyer, Bruce A.; Sachleben, Richard A.; Bonnesen, Peter V.

    1995-01-01

    A process for extracting technetium values from an aqueous alkaline solution containing at least one alkali metal hydroxide and at least one alkali metal nitrate, the at least one alkali metal nitrate having a concentration of from about 0.1 to 6 molar. The solution is contacted with a solvent consisting of a crown ether in a diluent for a period of time sufficient to selectively extract the technetium values from the aqueous alkaline solution. The solvent containing the technetium values is separated from the aqueous alkaline solution and the technetium values are stripped from the solvent.

  11. Alkaline sorbent injection for mercury control

    DOEpatents

    Madden, Deborah A.; Holmes, Michael J.

    2002-01-01

    A mercury removal system for removing mercury from combustion flue gases is provided in which alkaline sorbents at generally extremely low stoichiometric molar ratios of alkaline earth or an alkali metal to sulfur of less than 1.0 are injected into a power plant system at one or more locations to remove at least between about 40% and 60% of the mercury content from combustion flue gases. Small amounts of alkaline sorbents are injected into the flue gas stream at a relatively low rate. A particulate filter is used to remove mercury-containing particles downstream of each injection point used in the power plant system.

  12. Alkaline sorbent injection for mercury control

    DOEpatents

    Madden, Deborah A.; Holmes, Michael J.

    2003-01-01

    A mercury removal system for removing mercury from combustion flue gases is provided in which alkaline sorbents at generally extremely low stoichiometric molar ratios of alkaline earth or an alkali metal to sulfur of less than 1.0 are injected into a power plant system at one or more locations to remove at least between about 40% and 60% of the mercury content from combustion flue gases. Small amounts of alkaline sorbents are injected into the flue gas stream at a relatively low rate. A particulate filter is used to remove mercury-containing particles downstream of each injection point used in the power plant system.

  13. [Granulocyte alkaline phosphatase--a biomarker of chronic benzene exposure].

    PubMed

    Khristeva, V; Meshkov, T

    1994-01-01

    In tracing the cellular population status in the peripheral blood of workers, exposed to benzene, was included and cytochemical determination of the alkaline phosphatase activity in leucocytes. This enzyme is accepted as marker of the neutrophilic granulocytes, as maturation of the cells and their antibacterial activity are parallel to the cytochemical activity of the enzyme. 78 workers from the coke-chemical production from state firm "Kremikovtsi" and 41 workers from the production "Benzene" and "Isopropylbenzene"--Oil Chemical Plant, Burgas are included. The benzene concentrations in the air of the working places in all productions are in the range of 5 to 50 mg/m3. For cytochemical determination of the alkaline phosphatase activity is used the method of L. Kaplow and phosphatase index was calculated. It was established that in 98.4% of all examined the alkaline phosphatase activity is inhibited to different rate, as from 46.5% [61 workers] it is zero. In considerably lower percentage of workers were established and other deviations: leucocytosis or leucopenia, neutropenia, increased percent of band neutrophils and toxic granules. The results of the investigation of the granulocyte population show that from all indices, the activity of granulocyte alkaline phosphatase demonstrates most convincing the early myelotoxic effect of benzene.

  14. Remediation of Former Manufactured Gas Plant Tars Using Alkaline Flushing

    NASA Astrophysics Data System (ADS)

    Hauswirth, S.; Rylander, S.; Birak, P. S.; Miller, C. T.

    2010-12-01

    The remediation of former manufactured gas plant (FMGP) tars in the subsurface is particularly difficult due to the wetting behavior and high viscosities of these dense non-aqueous liquids (DNAPLs). Alkaline flooding is a technique which has proven effective in improving the recovery of crude oils, which share some characteristics with FMGP tars. For this study, we measured the effect of NaOH solutions on interfacial tension and conducted column experiments to investigate the feasibility of applying this technique to FMGP tars. The pendant drop technique was used to measure interfacial tensions for solutions ranging from 0-1% NaOH. Column experiments were conducted by contaminating sands with tars recovered from a FMGP then flushing the columns with NaOH solutions. A final, 70% v/v ethanol cosolvent flush was conducted to investigate the effectiveness of a two-stage remediation approach. The mass removal of tar, as well as 26 individual PAHs, was measured, along with the aqueous phase mass flux of PAHs after each flushing stage. The interfacial tension was reduced from about 20 mN/m with pure water to a minimum of 0.05 mN/m at a concentration of 0.1% NaOH. In the column experiments, alkaline flushing resulted in a 50% reduction of the residual saturation. Aqueous phase PAH concentrations, however, were similar before and after the alkaline flushing stage. The combination of alkaline and cosolvent flushing resulted in an overall reduction of 95% of the total mass of the 16 EPA PAHs. Final aqueous phase concentrations were reduced significantly for lower molecular weight PAHs, but increased slightly for the higher molecular weight compounds, likely due to their increased mole fraction within the remaining tar. Additional work is being conducted to improve the effectiveness of the alkaline flushing through the use of surfactants and polymers.

  15. Simplified Space Conditioning in Low-Load Homes: Results from Pittsburgh, Pennsylvania, New Construction Unoccupied Test House

    SciTech Connect

    Poerschke, Andrew; Stecher, Dave

    2014-06-01

    Field testing was performed in a new construction unoccupied test house in Pittsburgh, PA. Four air-based heating, ventilation, and air conditioning distribution systems—a typical airflow ducted system to the bedrooms, a low airflow ducted system to the bedrooms, a system with transfer fans to the bedrooms, and a system with no ductwork to the bedrooms—were evaluated during heating, cooling, and midseason conditions. The relative ability of each system was assessed with respect to relevant Air Conditioning Contractors of America and ASHRAE standards for house temperature uniformity and stability, respectively.

  16. Simplified Space Conditioning in Low-Load Homes: Results from Pittsburgh, Pennsylvania, New Construction Unoccupied Test House

    SciTech Connect

    Poerschke, A.; Stecher, D.

    2014-06-01

    Field testing was performed in a new construction unoccupied test house in Pittsburgh, Pennsylvania. Four air-based heating, ventilation, and air conditioning distribution systems--a typical airflow ducted system to the bedrooms, a low airflow ducted system to the bedrooms, a system with transfer fans to the bedrooms, and a system with no ductwork to the bedrooms--were evaluated during heating, cooling, and midseason conditions. The relative ability of each system was assessed with respect to relevant Air Conditioning Contractors of America and ASHRAE standards for house temperature uniformity and stability, respectively.

  17. Extracellular alkaline proteinase of Colletotrichum gloeosporioides.

    PubMed

    Dunaevsky, Ya E; Matveeva, A R; Beliakova, G A; Domash, V I; Belozersky, M A

    2007-03-01

    The main proteinase of the filamentous fungus Colletotrichum gloeosporioides causing anthracnoses and serious problems for production and storage of agricultural products has molecular mass of 57 kD and was purified more than 200-fold to homogeneity with the yield of 5%. Maximal activity of the proteinase is at pH 9.0-10.0, and the enzyme is stable at pH 6.0-11.5 (residual activity not less than 70%). The studied enzyme completely kept its activity to 55 degrees C, with a temperature optimum of 45 degrees C. The purified C. gloeosporioides proteinase is stable at alkaline pH values, but rapidly loses its activity at pH values lower than 5.0. Addition of bovine serum albumin stabilizes the enzyme under acidic conditions. Data on inhibitor analysis and substrate specificity of the enzyme allow its classification as a serine proteinase of subtilisin family. It is demonstrated that the extracellular proteinase of C. gloeosporioides specifically effects plant cell wall proteins. It is proposed that the studied proteinase--via hydrolysis of cell wall--provides for penetration of the fungus into the tissues of the host plant.

  18. The Origin of Life in Alkaline Hydrothermal Vents.

    PubMed

    Sojo, Victor; Herschy, Barry; Whicher, Alexandra; Camprubí, Eloi; Lane, Nick

    2016-02-01

    Over the last 70 years, prebiotic chemists have been very successful in synthesizing the molecules of life, from amino acids to nucleotides. Yet there is strikingly little resemblance between much of this chemistry and the metabolic pathways of cells, in terms of substrates, catalysts, and synthetic pathways. In contrast, alkaline hydrothermal vents offer conditions similar to those harnessed by modern autotrophs, but there has been limited experimental evidence that such conditions could drive prebiotic chemistry. In the Hadean, in the absence of oxygen, alkaline vents are proposed to have acted as electrochemical flow reactors, in which alkaline fluids saturated in H2 mixed with relatively acidic ocean waters rich in CO2, through a labyrinth of interconnected micropores with thin inorganic walls containing catalytic Fe(Ni)S minerals. The difference in pH across these thin barriers produced natural proton gradients with equivalent magnitude and polarity to the proton-motive force required for carbon fixation in extant bacteria and archaea. How such gradients could have powered carbon reduction or energy flux before the advent of organic protocells with genes and proteins is unknown. Work over the last decade suggests several possible hypotheses that are currently being tested in laboratory experiments, field observations, and phylogenetic reconstructions of ancestral metabolism. We analyze the perplexing differences in carbon and energy metabolism in methanogenic archaea and acetogenic bacteria to propose a possible ancestral mechanism of CO2 reduction in alkaline hydrothermal vents. Based on this mechanism, we show that the evolution of active ion pumping could have driven the deep divergence of bacteria and archaea.

  19. Aircraft and ground vehicle friction correlation test results obtained under winter runway conditions during joint FAA/NASA Runway Friction Program

    NASA Technical Reports Server (NTRS)

    Yager, Thomas J.; Vogler, William A.; Baldasare, Paul

    1988-01-01

    Aircraft and ground vehicle friction data collected during the Joint FAA/NASA Runway Friction Program under winter runway conditions are discussed and test results are summarized. The relationship between the different ground vehicle friction measurements obtained on compacted snow- and ice-covered conditions is defined together with the correlation to aircraft tire friction performance under similar runway conditions.

  20. Responses of alkaline phosphatase activity in Daphnia to poor nutrition.

    PubMed

    Wagner, Nicole D; Frost, Paul C

    2012-09-01

    The use of biochemical and molecular indices of nutritional stress have recently been promoted for their potential ability to assess the in situ nutritional state of zooplankton. The development and application of these indicators should at least consider the cross-reactivity with other nutritional stressors. We examined the potential usefulness of body alkaline phosphatase activity (APA) as an indicator of dietary phosphorus (P) stress in Daphnia. We measured growth rate, body P-content, and body APA of two species of Daphnia (D. magna, D. pulex) grown for different periods under diverse dietary conditions. We found P-poor food reduced daphnid growth rates and body P-content, while body APA increased in both species. However, body APA increased in P-sufficient D. magna and D. pulex that were feeding on cyanobacterial compared to green algal food, despite no differences in animal body P content. Body APA increased in D. magna fed P-poor food whether cyanobacterial or algal. Body APA also varied with age and other nutritional stresses (low food quantity, nitrogen-poor algae) in both daphnid species. Our results demonstrate that whole body homogenate APA in Daphnia is not singularly responsive to P-poor food, which will complicate or limit its future usefulness and application as an indicator of dietary P-stress in metazoans.

  1. Experimental Results of the First Two Stages of an Advanced Transonic Core Compressor Under Isolated and Multi-Stage Conditions

    NASA Technical Reports Server (NTRS)

    Prahst, Patricia S.; Kulkarni, Sameer; Sohn, Ki H.

    2015-01-01

    NASA's Environmentally Responsible Aviation (ERA) Program calls for investigation of the technology barriers associated with improved fuel efficiency of large gas turbine engines. Under ERA the task for a High Pressure Ratio Core Technology program calls for a higher overall pressure ratio of 60 to 70. This mean that the HPC would have to almost double in pressure ratio and keep its high level of efficiency. The challenge is how to match the corrected mass flow rate of the front two supersonic high reaction and high corrected tip speed stages with a total pressure ratio of 3.5. NASA and GE teamed to address this challenge by using the initial geometry of an advanced GE compressor design to meet the requirements of the first 2 stages of the very high pressure ratio core compressor. The rig was configured to run as a 2 stage machine, with Strut and IGV, Rotor 1 and Stator 1 run as independent tests which were then followed by adding the second stage. The goal is to fully understand the stage performances under isolated and multi-stage conditions and fully understand any differences and provide a detailed aerodynamic data set for CFD validation. Full use was made of steady and unsteady measurement methods to isolate fluid dynamics loss source mechanisms due to interaction and endwalls. The paper will present the description of the compressor test article, its predicted performance and operability, and the experimental results for both the single stage and two stage configurations. We focus the detailed measurements on 97 and 100 of design speed at 3 vane setting angles.

  2. Conditional inactivation of TNFα-converting enzyme in chondrocytes results in an elongated growth plate and shorter long bones.

    PubMed

    Saito, Kenta; Horiuchi, Keisuke; Kimura, Tokuhiro; Mizuno, Sakiko; Yoda, Masaki; Morioka, Hideo; Akiyama, Haruhiko; Threadgill, David; Okada, Yasunori; Toyama, Yoshiaki; Sato, Kazuki

    2013-01-01

    TNFα-converting enzyme (TACE) is a membrane-bound proteolytic enzyme with essential roles in the functional regulation of TNFα and epidermal growth factor receptor (EGFR) ligands. Previous studies have demonstrated critical roles for TACE in vivo, including epidermal development, immune response, and pathological neoangiogenesis, among others. However, the potential contribution of TACE to skeletal development is still unclear. In the present study, we generated a Tace mutant mouse in which Tace is conditionally disrupted in chondrocytes under the control of the Col2a1 promoter. These mutant mice were fertile and viable but all exhibited long bones that were approximately 10% shorter compared to those of wild-type animals. Histological analyses revealed that Tace mutant mice exhibited a longer hypertrophic zone in the growth plate, and there were fewer osteoclasts at the chondro-osseous junction in the Tace mutant mice than in their wild-type littermates. Of note, we found an increase in osteoprotegerin transcripts and a reduction in Rankl and Mmp-13 transcripts in the TACE-deficient cartilage, indicating that dysregulation of these genes is causally related to the skeletal defects in the Tace mutant mice. Furthermore, we also found that phosphorylation of EGFR was significantly reduced in the cartilage tissue lacking TACE, and that suppression of EGFR signaling increases osteoprotegerin transcripts and reduces Rankl and Mmp-13 transcripts in primary chondrocytes. In accordance, chondrocyte-specific abrogation of Egfr in vivo resulted in skeletal defects nearly identical to those observed in the Tace mutant mice. Taken together, these data suggest that TACE-EGFR signaling in chondrocytes is involved in the turnover of the growth plate during postnatal development via the transcriptional regulation of osteoprotegerin, Rankl, and Mmp-13.

  3. Acid rock drainage passive remediation: Potential use of alkaline clay, optimal mixing ratio and long-term impacts.

    PubMed

    Plaza, Fernando; Wen, Yipei; Perone, Hanna; Xu, Yi; Liang, Xu

    2017-01-15

    Acid rock drainage (ARD) is one of the most adverse environmental problems of the mining industry. Surface and ground water affected by this pollution are characterized by their acidity and the high content of sulfates and metals/metalloids. In this study, alkaline clay (AC), an industrial waste with a high alkalinity, which is utilized in the alumina refining process, was used as the remediation material to inhibit pyrite oxidation in waste coal piles. Through a series of laboratory experiments (static and kinetic), complemented with field measurements and geochemical modeling, three important issues associated with this passive and sustainable ARD remediation method were investigated: 1) the potential use of alkaline clay as an ARD remediation material, 2) the adequate alkaline clay/coal refuse mixing ratio (AC/CR) to ensure pH values close to neutral conditions, and, 3) the implications for long-term performance, in terms of the trends of the main parameters involved in this process such as pH, concentrations of sulfate, iron and other dissolved contaminants. Both field measurements and the samples used for the experiments came from a local waste coal site. Through the analysis of the field measurements and the outcome of the laboratory experiments, AC proved to be an effective remediation material for ARD. Compared to those found in mine tailings, the concentrations of contaminants such as iron, manganese or sulfate were significantly reduced with this remediation approach. Moreover, results suggest a reliable long-term stability of the remediation (i.e. neutral pH conditions are maintained), thus enhancing the generation of iron precipitates that could produce pyrite grain coating. These processes also made the amended layer less porous, thus increased water retention and hindered oxygen diffusion.

  4. Acid Mine Drainage Passive Remediation: Potential Use of Alkaline Clay, Optimal Mixing Ratio and Long Term Impacts

    NASA Astrophysics Data System (ADS)

    Plaza, F.; Liang, X.; Wen, Y.; Perone, H.

    2015-12-01

    Acid mine drainage (AMD) is one of the most adverse environmental problems of the mine industry. Surface water and ground water affected by this pollution are characterized by their acidity and the high content of sulfates and heavy metals. In this study, alkaline clay, an industrial waste with a high pH, which is utilized in the alumina refining process, was used as the remediation material to inhibit pyrite oxidation. Through a series of batch and column experiments, complemented with field measurements and geochemical modeling, three important issues associated with this passive and auto sustainable acid mine drainage remediation method were investigated: 1) the potential use of alkaline clay as an AMD remediation material, 2) the adequate alkaline clay/coal refuse mixing ratio (AC/CR) to ensure pH values near to neutral conditions, and, 3) the prediction of long term impacts, in terms of the trends of the main parameters involved in this process such as pH, concentrations of sulfate, iron and other dissolved contaminants. Both field measurements and the samples used for the experiments came from a coal waste site located in Mather, Pennsylvania. Alkaline clay proved to be an effective remediation material for AMD. It was found that 10% AC/CR is an adequate mixing ratio (i.e. the upper limit), which has been also indicated by field measurements. The concentrations of some contaminants such as iron, manganese or sulfate are significantly reduced with the remediation approach, compared to those representative concentrations found in mine tailings. Moreover, results suggest a very reliable long-term stability of the remediation (i.e. neutral pH conditions are maintained), thus enhancing the generation of iron precipitates that could produce pyrite grain coating and hardpan (i.e. cemented layer) on the surface. These processes also made the amended layer less porous, thus increasing water retention and hindering oxygen diffusion.

  5. Alkaline direct transesterification of different species of Stichococcus for bio-oil production.

    PubMed

    Gargano, Immacolata; Marotta, Raffaele; Andreozzi, Roberto; Olivieri, Giuseppe; Marzocchella, Antonio; Spasiano, Danilo; Pinto, Gabriele; Pollio, Antonino

    2016-12-25

    The cost of bio-oil refining from microalgal biomass can be significantly reduced by combining extraction and transesterification. The characterisation and optimisation of the combined steps have been carried out on strains of Stichococcus bacillaris, focusing on catalyst type and concentration, reaction time and temperature, methanol/biomass ratio, pre-mixing time and water content in the biomass. The bio-oil yield has been referenced as production of fatty acid methyl esters (FAMEs). The maximum yield (∼17%) was achieved using dried biomass with alkaline catalyst at 60°C and methanol/biomass weight ratio of 79:1. Alkaline catalyst conditions gave faster reaction rates and higher bio-oil yields than acid catalyst. Yield was also strongly affected by water content in the biomass. A mechanistic interpretation has been proposed to elucidate the effect of the different operating conditions. However, the structural characteristics of the Chlorophyta cell wall can be very different, leading to different bio-oil yields when the same protocol is applied. Therefore, the optimised protocol of direct transesterification for Stichococcus bacillaris strains was tested on other Stichococcus strains and several other Chlorophyta species characterised by a different cell wall structure. It was clearly demonstrated that different results for bio-oil yield were obtained within the same microalgal species and much more within different microalgal genera.

  6. Alkaline tolerant dextranase from streptomyces anulatus

    DOEpatents

    Decker, Stephen R.; Adney, William S.; Vinzant, Todd B.; Himmel, Michael E.

    2003-01-01

    A process for production of an alkaline tolerant dextranase enzyme comprises culturing a dextran-producing microorganism Streptomyces anulatus having accession no. ATCC PTA-3866 to produce an alkaline tolerant dextranase, Dex 1 wherein the protein in said enzyme is characterized by a MW of 63.3 kDa and Dex 2 wherein its protein is characterized by a MW of 81.8 kDa.

  7. Technetium recovery from high alkaline solution

    DOEpatents

    Nash, Charles A.

    2016-07-12

    Disclosed are methods for recovering technetium from a highly alkaline solution. The highly alkaline solution can be a liquid waste solution from a nuclear waste processing system. Methods can include combining the solution with a reductant capable of reducing technetium at the high pH of the solution and adding to or forming in the solution an adsorbent capable of adsorbing the precipitated technetium at the high pH of the solution.

  8. Toxicity of alkalinity to Hyalella azteca

    USGS Publications Warehouse

    Lasier, P.J.; Winger, P.V.; Reinert, R.E.

    1997-01-01

    Toxicity testing and chemical analyses of sediment pore water have been suggested for use in sediment quality assessments and sediment toxicity identification evaluations. However, caution should be exercised in interpreting pore-water chemistry and toxicity due to inherent chemical characteristics and confounding relationships. High concentrations of alkalinity, which are typical of sediment pore waters from many regions, have been shown to be toxic to test animals. A series of tests were conducted to assess the significance of elevated alkalinity concentrations to Hyalella azteca, an amphipod commonly used for sediment and pore-water toxicity testing. Toxicity tests with 14-d old and 7-d old animals were conducted in serial dilutions of sodium bicarbonate (NaHCO3) solutions producing alkalinities ranging between 250 to 2000 mg/L as CaCO3. A sodium chloride (NaCl) toxicity test was also conducted to verify that toxicity was due to bicarbonate and not sodium. Alkalinity was toxic at concentrations frequently encountered in sediment pore water. There was also a significant difference in the toxicity of alkalinity between 14-d old and 7-d old animals. The average 96-h LC50 for alkalinity was 1212 mg/L (as CaCO3) for 14-d old animals and 662 mg/L for the younger animals. Sodium was not toxic at levels present in the NaHCO3 toxicity tests. Alkalinity should be routinely measured in pore-water toxicity tests, and interpretation of toxicity should consider alkalinity concentration and test-organism tolerance.

  9. COUPLING THE ALKALINE-SURFACTANT-POLYMER TECHNOLOGY AND THE GELATION TECHNOLOGY TO MAXIMIZE OIL PRODUCTION

    SciTech Connect

    Malcolm Pitts; Jie Qi; Dan Wilson

    2004-10-01

    Gelation technologies have been developed to provide more efficient vertical sweep efficiencies for flooding naturally fractured oil reservoirs or more efficient areal sweep efficiency for those with high permeability contrast ''thief zones''. The field proven alkaline-surfactant-polymer technology economically recovers 15% to 25% OOIP more oil than waterflooding from swept pore space of an oil reservoir. However, alkaline-surfactant-polymer technology is not amenable to naturally fractured reservoirs or those with thief zones because much of injected solution bypasses target pore space containing oil. This work investigates whether combining these two technologies could broaden applicability of alkaline-surfactant-polymer flooding into these reservoirs. A prior fluid-fluid report discussed interaction of different gel chemical compositions and alkaline-surfactant-polymer solutions. Gel solutions under dynamic conditions of linear corefloods showed similar stability to alkaline-surfactant-polymer solutions as in the fluid-fluid analyses. Aluminum-polyacrylamide, flowing gels are not stable to alkaline-surfactant-polymer solutions of either pH 10.5 or 12.9. Chromium acetate-polyacrylamide flowing and rigid flowing gels are stable to subsequent alkaline-surfactant-polymer solution injection. Rigid flowing chromium acetate-polyacrylamide gels maintained permeability reduction better than flowing chromium acetate-polyacrylamide gels. Silicate-polyacrylamide gels are not stable with subsequent injection of either a pH 10.5 or a 12.9 alkaline-surfactant-polymer solution. Neither aluminum citrate-polyacrylamide nor silicate-polyacrylamide gel systems produced significant incremental oil in linear corefloods. Both flowing and rigid flowing chromium acetate-polyacrylamide gels produced incremental oil with the rigid flowing gel producing the greatest amount. Higher oil recovery could have been due to higher differential pressures across cores. None of the gels tested

  10. Aqueous Alkaline Cleaners: An Alternative to Organic Solvents

    DTIC Science & Technology

    1993-09-01

    74 7.10 Econom ics ............................................. 75 7.11 Alkaline Cleaners vs. Terpene Cleaners...the financial burden of waste disposal. A previous study25 was performed by USACERL to determine if semi-aqueous terpene cleaner could be used as a...organic soivents. 5. Discuss results based on research. 6. Contrast the results of this study with the previous work examining terpene -based cleaners. 25

  11. Managing land application of coal seam water: A field study of land amendment irrigation using saline-sodic and alkaline water on a Red Vertisol.

    PubMed

    Bennett, J McL; Marchuk, A; Raine, S R; Dalzell, S A; Macfarlane, D C

    2016-12-15

    Coal seam (CS) gas operations coproduce water with gas from confined CS aquifers. This CS water represents a potential agricultural resource if the water is able to be chemically amended to comply with management guidelines. Stoichiometric quantities of sulphur and gypsum amendments can be used to neutralise the alkalinity and reduce the sodicity of CS water respectively. These amendments can either be mixed in-line at a water treatment plant or applied directly to land prior to the application of CS water (a practice termed land amendment irrigation - LAI). This study compared the efficacy of LAI with in-line chemical amendment of CS water and irrigation with non-saline, non-sodic and non-alkaline (good quality) water under field conditions in southern Queensland. Soil chemical properties, soluble Ca, Mg, K, Na, electrical conductivity (EC), pH, chloride and alkalinity, as well as saturated hydraulic conductivity were measured to determine the impact of the irrigation treatments on soil chemical and physical conditions. Irrigation of lucerne pasture using solid-set sprinklers applied a total of 6.7 ML/ha of each treatment irrigation water to the experimental plots over a 10-month period. Alkalinity was neutralised using LAI, with no increase in soil alkalinity observed. Soil sodicity did not exceed threshold electrolyte concentration values under either CS water irrigation treatment. Soil chemical and physical properties were comparable for both LAI and in-line chemical amendment of CS water. Soil saturated hydraulic conductivity was maintained under all irrigation treatments. Results showed that the constrained capacity of the irrigation system was unable to meet crop evapotranspiration demand. This resulted in accumulation of salt within the root-zone under the CS water treatments compared to the good quality water treatment. LAI successfully chemically amended Bowen Basin CS water facilitating its beneficial use for agricultural irrigation.

  12. The use of alkaline hydrolysis as a novel strategy for chloroform remediation: the feasibility of using construction wastes and evaluation of carbon isotopic fractionation.

    PubMed

    Torrentó, Clara; Audí-Miró, Carme; Bordeleau, Geneviève; Marchesi, Massimo; Rosell, Mònica; Otero, Neus; Soler, Albert

    2014-01-01

    Laboratory and field-scale pilot experiments were performed to evaluate the feasibility of chloroform degradation by alkaline hydrolysis and the potential of δ(13)C values to assess this induced reaction process at contaminated sites. In batch experiments, alkaline conditions were induced by adding crushed concrete (pH 12.33 ± 0.07), a filtered concrete solution (pH 12.27 ± 0.04), a filtered cement solution (pH 12.66 ± 0.02) and a pH 12 buffer solution (pH 11.92 ± 0.11). The resulting chloroform degradation after 28 days was 94, 96, 99, and 72%, respectively. The experimental data were described using a pseudo-first-order kinetic model, resulting in pseudo-first-order rate constant values of 0.10, 0.12, 0.20, and 0.05 d(-1), respectively. Furthermore, the significant chloroform carbon isotopic fractionation associated with alkaline hydrolysis of chloroform (-53 ± 3‰) and its independence from pH in the admittedly limited tested pH range imply a great potential for the use of δ(13)C values for in situ monitoring of the efficacy of remediation approaches based on alkaline hydrolysis. The carbon isotopic fractionation obtained at the lab scale allowed the calculation of the percentage of chloroform degradation in field-scale pilot experiments where alkaline conditions were induced in two recharge water interception trenches filled with concrete-based construction wastes. A maximum of approximately 30-40% of chloroform degradation was achieved during the two studied recharge periods. Although further research is required, the treatment of chloroform in groundwater through the use of concrete-based construction wastes is proposed. This strategy would also imply the recycling of construction and demolition wastes for use in value-added applications to increase economic and environmental benefits.

  13. WCPSS Teacher Working Conditions Survey Results: 2011-12. Data Trends. D&A Report No.12.13

    ERIC Educational Resources Information Center

    Halstead, Elizabeth O.

    2012-01-01

    During the spring of 2012, over 100,000 educators across the state took the North Carolina Teacher Working Conditions (TWC) survey. Wake County Public School System (WCPSS) teachers responded more positively to 46 of the 85 survey items in 2012 than did teachers statewide. On 14 items, WCPSS teachers' responses were less favorable than those of…

  14. A PROBABILISTIC ASSESSMENT OF BENTHIC CONDITION OF WEST COAST ESTUARIES: RESULTS FROM THE NATIONAL COASTAL ASSESSMENT 1999-2000

    EPA Science Inventory

    As part of the National Coastal Assessment, the Environmental Monitoring and Assessment Program of EPA is conducting a six year evaluation of benthic habitat condition for coastal waters of the western U.S. In 1999, probabilistic sampling for a range of biotic and abiotic conditi...

  15. US/MEXICO STUDY: NALC/MEXICO LAND COVER MAPPING RESULTS-IMPLICATIONS FOR ASSESSING LANDSCAPE CONDITIONS

    EPA Science Inventory

    An inventory of land-cover conditions throughout Mexico was performed using North American Landscape Characterization (NLAC) Landsat Mult-Spectral Scann (MSS) 'triplicate' images, corresponding to the 1970s, 1980s and 1990s epoch periods. The equivalents of 300 image scenes were...

  16. [Some enzymatic activities of the amniotic fluid in human beings (LAP, GGTP, SGOT, SGPT, acid and alkaline phosphatases, 5' nucleotidase, amylase, beta-glucuronidase and aldolase)].

    PubMed

    Galerne, D; Baudon, J; Bruhat, M; Dastugue, G

    1973-10-01

    Quantitative analyses of 10 enzymes (LAP, GGTP, SGOT, SGPT. acid and alkaline phosphatases, 5' nucleotidase, amylase. beta-glucuronidase and aldolase) in a series of 50 samples of amniotic fluid gave widely-scattered results. In some cases, it was possible to relate high enzymatic activity to a pathological condition, in other cases, the amniotic fluid examined seemed to come from normal, full-term or almost full-term pregnancies without particular signs.

  17. [Alkaline phosphatase in Amoeba proteus].

    PubMed

    Sopina, V A

    2005-01-01

    In free-living Amoeba proteus (strain B), 3 phosphatase were found after disc-electrophoresis of 10 microg of protein in PAGE and using 1-naphthyl phosphate as a substrate a pH 9.0. These phosphatases differed in their electrophoretic mobilities - "slow" (1-3 bands), "middle" (one band) and "fast" (one band). In addition to 1-naphthyl phosphate, "slow" phosphatases were able to hydrolyse 2-naphthyl phosphate and p-nitrophenyl phosphate. They were slightly activated by Mg2+, completely inhibited by 3 chelators (EDTA, EGTA and 1,10-phenanthroline), L-cysteine, sodium dodecyl sulfate and Fe2+, Zn2+ and Mn2+ (50 mM), considerably inactivated by orthovanadate, molybdate, phosphatase inhibitor cocktail 1, p-nitrophenyl phosphate, Na2HPO4, DL-dithiothreitol and urea and partly inhibited by H2O2, DL-phenylalanine, 2-mercaptoethanol, phosphatase inhibitor cocktail 2 and Ca2+. Imidazole, L-(+)-tartrate, okadaic acid, NaF and sulfhydryl reagents -p-(hydroxy-mercuri)benzoate and N-ethylmaleimide - had no influence on the activity of "slow" phosphatases. "Middle" and "fast" phosphatases, in contrast to "slow" ones, were not inactivated by 3 chelators. The "middle" phosphatase differed from the "fast" one by smaller resistance to urea, Ca2+, Mn2+, phosphates and H2O2 and greater resistance to dithiothreitol and L-(+)-tartrate. In addition, the "fast" phosphatase was inhibited by L-cysteine but the "middle" one was activated by it. Of 5 tested ions (Mg2+, Cu2+, Mn2+, Ca2+ and Zn2+), only Zn2+ reactivated "slow" phosphatases after their inactivation by EDTA treatment. The reactivation of apoenzyme was only partial (about 35 %). Thus, among phosphatases found in amoebae at pH 9.0, only "slow" ones are Zn-metalloenzymes and may be considered as alkaline phosphatases (EC 3.1.3.1). It still remains uncertain, to which particular phosphatase class "middle" and "fast" phosphatases (pH 9.0) may belong.

  18. Alkaline protease from Thermoactinomyces sp. RS1 mitigates industrial pollution.

    PubMed

    Verma, Amit; Ansari, Mohammad W; Anwar, Mohmmad S; Agrawal, Ruchi; Agrawal, Sanjeev

    2014-05-01

    Proteases have found a wide application in the several industrial processes, such as laundry detergents, protein recovery or solubilization, prion degradation, meat tenderizations, and in bating of hides and skins in leather industries. But the main hurdle in industrial application of proteases is their economical production on a large scale. The present investigation aimed to exploit the locally available inexpensive agricultural and household wastes for alkaline protease production using Thermoactinomyces sp. RS1 via solid-state fermentation (SSF) technique. The alkaline enzyme is potentially useful as an additive in commercial detergents to mitigate pollution load due to extensive use of caustic soda-based detergents. Thermoactinomyces sp. RS1 showed good protease production under SSF conditions of 55 °C, pH 9, and 50 % moisture content with potato peels as solid substrate. The presented findings revealed that crude alkaline protease produced by Thermoactinomyces sp. RS1 via SSF is of potential application in silver recovery from used X-ray films.

  19. Microscopic examination of volcanic rocks subjected to alkaline leaching

    NASA Astrophysics Data System (ADS)

    Seidlova, Z.; Prikryl, R.; Sachlova, S.

    2012-04-01

    Volcanic rocks supply one third of crushed stone in the Czech Republic. Some of these rocks significantly contribute to concrete damage by alkali silica reaction (ASR) as has been recognised by previous studies in several concrete constructions (dams, highways, bridges). In recent study, volcanic rocks (basalts, spilites, melaphyres, phonolites, rhyolites, diabases) were subjected to several test procedures aiming to evaluate their ASR potential. The experimental study employed accelerated mortar bar test (following the standard ASTM C1260), chemical test (following the standard ASTM C289), and microscopic techniques (polarising microscopy, scanning electron microscopy combined with energy dispersive analysis). The interaction of cement paste and aggregate under high alkaline solution and increasing temperature conditions takes place during the accelerated mortar bar test. Microscopic techniques applied on mortar bar specimens enabled identification of ASR products (alkali-silica gels). Chemical test quantified ASR potential based on the amount of Si4+ leached into the solution within 24 hours testing period and contemporaneous reduction of alkalinity. Volcanic particles leached in alkaline solution were subjected to microscopic analysis with the aim to find minerals (phases) affecting their ASR potential. ASR of volcanic rocks was found highly variable connected to the mineral composition. The highest degree of ASR was found in connection with melaphyres, rhyolites and one sample of spilite. The main factor influencing ASR of investigated aggregates is regarded in the presence of SiO2-rich phases (e.g. SiO2-rich glass).

  20. Performance of a sulfidogenic bioreactor and bacterial community shifts under different alkalinity levels.

    PubMed

    Zhao, Yang-Guo; Li, Xin-Wei; Wang, Jun-Cai; Bai, Jie; Tian, Wei-Jun

    2010-12-01

    The performance of a sulfidogenic bioreactor and the response of bacterial populations to influent alkalinity changes were investigated. The bioreactor reached 40% of sulfate removal efficiency (SRE) with 0 mg l(-1) of alkalinity, and single-stranded conformation polymorphism profiles showed that some members of Bacteroides, Dysgonomonas, Sporobacter, Quinella, and Citrobacter became dominant populations. 16S rRNA gene library analysis indicated that the Actinobacteria group increased from 0% in seed to 23% in sludge. An increase in alkalinity to 1300 mg l(-1) led to a rapid increase of SRE to 65% and changes in the bacterial community. Sequences representing Dysgonomonas, Raoultella, Kluyvera, and Phascolarctobacterium were now found. When alkalinity was deceased to 0 mg l(-1), SRE dropped and the bands representing Raoultella, Kluyvera, and Phascolarctobacterium disappeared, while bands representing Clostridium appeared. A second cycle of low/high alkalinity did not result in obvious changes to the bacterial community. These results indicate that the sulfidogenic bioreactor favored higher influent alkalinity and that the different functional microbial populations responded well to the alkalinity changes.

  1. COUPLING THE ALKALINE-SURFACTANT-POLYMER TECHNOLOGY AND THE GELATION TECHNOLOGY TO MAXIMIZE OIL PRODUCTION

    SciTech Connect

    Malcolm Pitts; Jie Qi; Dan Wilson; David Stewart; Bill Jones

    2005-04-01

    Gelation technologies have been developed to provide more efficient vertical sweep efficiencies for flooding naturally fractured oil reservoirs or more efficient areal sweep efficiency for those with high permeability contrast ''thief zones''. The field proven alkaline-surfactant-polymer technology economically recovers 15% to 25% OOIP more oil than waterflooding from swept pore space of an oil reservoir. However, alkaline-surfactant-polymer technology is not amenable to naturally fractured reservoirs or those with thief zones because much of injected solution bypasses target pore space containing oil. This work investigates whether combining these two technologies could broaden applicability of alkaline-surfactant-polymer flooding into these reservoirs. A prior fluid-fluid report discussed interaction of different gel chemical compositions and alkaline-surfactant-polymer solutions. Gel solutions under dynamic conditions of linear corefloods showed similar stability to alkaline-surfactant-polymer solutions as in the fluid-fluid analyses. Aluminum-polyacrylamide, flowing gels are not stable to alkaline-surfactant-polymer solutions of either pH 10.5 or 12.9. Chromium acetate-polyacrylamide flowing and rigid flowing gels are stable to subsequent alkaline-surfactant-polymer solution injection. Rigid flowing chromium acetate-polyacrylamide gels maintained permeability reduction better than flowing chromium acetate-polyacrylamide gels. Silicate-polyacrylamide gels are not stable with subsequent injection of either a pH 10.5 or a 12.9 alkaline-surfactant-polymer solution. Chromium acetate-xanthan gum rigid gels are not stable to subsequent alkaline-surfactant-polymer solution injection. Resorcinol-formaldehyde gels were stable to subsequent alkaline-surfactant-polymer solution injection. When evaluated in a dual core configuration, injected fluid flows into the core with the greatest effective permeability to the injected fluid. The same gel stability trends to subsequent

  2. Salmon and steelhead in the White Salmon River after the removal of Condit Dam–Planning efforts and recolonization results

    USGS Publications Warehouse

    Allen, Brady; Engle, Rod O; Zendt, Joseph S; Shrier, Frank C; Wilson, Jeremy T; Connolly, Patrick J.

    2016-01-01

    Condit Dam, at river kilometer 5.3 on the White Salmon River, Washington, was breached in 2011 and completely removed in 2012. This action opened habitat to migratory fish for the first time in 100 years. The White Salmon Working Group was formed to create plans for fish salvage in preparation for fish recolonization and to prescribe the actions necessary to restore anadromous salmonid populations in the White Salmon River after Condit Dam removal. Studies conducted by work group members and others served to inform management decisions. Management options for individual species were considered, including natural recolonization, introduction of a neighboring stock, hatchery supplementation, and monitoring natural recolonization for some time period to assess the need for hatchery supplementation. Monitoring to date indicates that multiple species and stocks of anadromous salmonids are finding and spawning in the now accessible and recovering habitat.

  3. Days out of role due to common physical and mental conditions: results from the WHO World Mental Health surveys

    PubMed Central

    Alonso, J; Petukhova, M; Vilagut, G; Chatterji, S; Heeringa, S; Üstün, T B; Alhamzawi, A O; Viana, M C; Angermeyer, M; Bromet, E; Bruffaerts, R; de Girolamo, G; Florescu, S; Gureje, O; Haro, J M; Hinkov, H; Hu, C-y; Karam, E G; Kovess, V; Levinson, D; Medina-Mora, M E; Nakamura, Y; Ormel, J; Posada-Villa, J; Sagar, R; Scott, K M; Tsang, A; Williams, D R; Kessler, R C

    2011-01-01

    Days out of role because of health problems are a major source of lost human capital. We examined the relative importance of commonly occurring physical and mental disorders in accounting for days out of role in 24 countries that participated in the World Health Organization (WHO) World Mental Health (WMH) surveys. Face-to-face interviews were carried out with 62 971 respondents (72.0% pooled response rate). Presence of ten chronic physical disorders and nine mental disorders was assessed for each respondent along with information about the number of days in the past month each respondent reported being totally unable to work or carry out their other normal daily activities because of problems with either physical or mental health. Multiple regression analysis was used to estimate associations of specific conditions and comorbidities with days out of role, controlling by basic socio-demographics (age, gender, employment status and country). Overall, 12.8% of respondents had some day totally out of role, with a median of 51.1 a year. The strongest individual-level effects (days out of role per year) were associated with neurological disorders (17.4), bipolar disorder (17.3) and post-traumatic stress disorder (15.2). The strongest population-level effect was associated with pain conditions, which accounted for 21.5% of all days out of role (population attributable risk proportion). The 19 conditions accounted for 62.2% of all days out of role. Common health conditions, including mental disorders, make up a large proportion of the number of days out of role across a wide range of countries and should be addressed to substantially increase overall productivity. PMID:20938433

  4. Specialties of distributions of alkaline-earth metals in coal

    SciTech Connect

    Fan Jinchuan; Fan Minqiang

    1997-12-31

    Four different ranks of coal have been sampled and separated into different density fractions by Float-Sink. The contents of some trace elements in each density fraction has been analyzed by ICAP. The analyzed data show that the alkaline-earth metals (Be, Sr, and Ba) have their special distributions in coal: Be and Sr may exist in the form of organic matter. Ba often has the highest content in the middle density fraction (1.4--1.5). The relative relationship between ash (or sulfur) and the trace element in a certain type of coal was obtained by using linear regression approach. Results show that there is no significant correlation between the contents of ash or sulfur and those of Be, Sr, and Ba. On the other hand, the linear regression was done among the trace elements of 17 types of coal. The results also show that there is no significant correlation between ash or sulfur and alkaline-earth metals.

  5. Summary technical report on the electrochemical treatment of alkaline nuclear wastes

    SciTech Connect

    Hobbs, D.T.

    1994-07-30

    This report summarizes the laboratory studies investigating the electrolytic treatment of alkaline solutions carried out under the direction of the Savannah River Technology Center from 1985-1992. Electrolytic treatment has been demonstrated at the laboratory scale to be feasible for the destruction of nitrate and nitrite and the removal of radioactive species such as {sup 99}Tc and {sup 106}Ru from Savannah River Site (SRS) decontaminated salt solution and other alkaline wastes. The reaction rate and current efficiency for the removal of these species are dependent on cell configuration, electrode material, nature of electrode surface, waste composition, current density, and temperature. Nitrogen, ammonia, and nitrous oxide have been identified as the nitrogen-containing reaction products from the electrochemical reduction of nitrate and nitrite under alkaline conditions. The reaction mechanism for the reduction is very complex. Voltammetric studies indicated that the electrode reactions involve surface phenomena and are not necessarily mass transfer controlled. In an undivided cell, results suggest an electrocatalytic role for oxygen via the generation of the superoxide anion. In general, more efficient reduction of nitrite and nitrate occurs at cathode materials with higher overpotentials for hydrogen evolution. Nitrate and nitrite destruction has also been demonstrated in engineering-scale flow reactors. In flow reactors, the nitrate/nitrite destruction efficiency is improved with an increase in the current density, temperature, and when the cell is operated in a divided cell configuration. Nafion{reg_sign} cation exchange membranes have exhibited good stability and consistent performance as separators in the divided-cell tests. The membranes were also shown to be unaffected by radiation at doses approximating four years of cell operation in treating decontaminated salt solution.

  6. Improving electrochemical methods of producing hydrogen in alkaline media via ammonia and urea electrolysis

    NASA Astrophysics Data System (ADS)

    Boggs, Bryan Kenneth

    Theoretically, ammonia electrolysis consumes 95% less energy than its major competitor water electrolysis and offers an economical, environmental, and efficient means for reducing nitrate contaminations in ground and drinking water. Thermodynamically at standard conditions, ammonia electrolysis consumes 1.55 Wh to produce one gram of hydrogen. This same gram of hydrogen generates 33 Wh utilizing a proton exchange membrane fuel cell (PEMFC). There is a potential of 31.45 Wh of net energy when coupling an ammonia electrolytic cell (AEC) and a PEMFC. Considering that PEMFCs are 60% efficient, the actual energy output ranges between 18 and 20 Wh. Prior to the research shown here, ammonia electrolysis in alkaline media was requiring more than 20 Wh of energy input due to slow anode kinetics and poor electrochemical cell design thus making any chances of a self-sustaining energy generator unfeasible. This research focused on improving and optimizing anode electrocatalyst materials, electrode configurations, and cell designs, as well as demonstrating stationary and mobile applications of ammonia electrolysis. In addition to ammonia electrolysis, a novel electrochemical technique, urea electrolysis in alkaline media, was created and investigated. Similar to ammonia electrolysis, the anodic reaction, which is the oxidation of urea, was found to be the most rate-limiting half-cell reaction and required improvement. This research focused on fundamentally understanding the mechanism of urea electrolysis as well as investigating common electrocatalysts for small organic molecules. As a result, urea electrolysis in alkaline media proved to be a direct, economical, and environmental approach to producing hydrogen electrochemically with an inexpensive transition metal.

  7. Catalytically active alkaline molten globular enzyme: Effect of pH and temperature on the structural integrity of 5-aminolevulinate synthase.

    PubMed

    Stojanovski, Bosko M; Breydo, Leonid; Hunter, Gregory A; Uversky, Vladimir N; Ferreira, Gloria C

    2014-12-01

    5-Aminolevulinate synthase (ALAS), a pyridoxal-5'phosphate (PLP)-dependent enzyme, catalyzes the first step of heme biosynthesis in mammals. Circular dichroism (CD) and fluorescence spectroscopies were used to examine the effects of pH (1.0-3.0 and 7.5-10.5) and temperature (20 and 37°C) on the structural integrity of ALAS. The secondary structure, as deduced from far-UV CD, is mostly resilient to pH and temperature changes. Partial unfolding was observed at pH2.0, but further decreasing pH resulted in acid-induced refolding of the secondary structure to nearly native levels. The tertiary structure rigidity, monitored by near-UV CD, is lost under acidic and specific alkaline conditions (pH10.5 and pH9.5/37°C), where ALAS populates a molten globule state. As the enzyme becomes less structured with increased alkalinity, the chiral environment of the internal aldimine is also modified, with a shift from a 420nm to 330nm dichroic band. Under acidic conditions, the PLP cofactor dissociates from ALAS. Reaction with 8-anilino-1-naphthalenesulfonic acid corroborates increased exposure of hydrophobic clusters in the alkaline and acidic molten globules, although the reaction is more pronounced with the latter. Furthermore, quenching the intrinsic fluorescence of ALAS with acrylamide at pH1.0 and 9.5 yielded subtly different dynamic quenching constants. The alkaline molten globule state of ALAS is catalytically active (pH9.5/37°C), although the kcat value is significantly decreased. Finally, the binding of 5-aminolevulinate restricts conformational fluctuations in the alkaline molten globule. Overall, our findings prove how the structural plasticity of ALAS contributes to reaching a functional enzyme.

  8. Petrogenesis of coeval silica-saturated and silica-undersaturated alkaline rocks: Mineralogical and geochemical evidence from the Saima alkaline complex, NE China

    NASA Astrophysics Data System (ADS)

    Zhu, Yu-Sheng; Yang, Jin-Hui; Sun, Jin-Feng; Zhang, Ji-Heng; Wu, Fu-Yuan

    2016-03-01

    A combined study of zircon U-Pb ages, mineral chemistry, whole-rock elements and Sr-Nd-Hf isotopes was carried out for the Saima alkaline complex in the northeastern China, in order to investigate the source and petrogenesis of coeval silica-saturated and silica-undersaturated alkaline rocks. The Saima alkaline complex consists of nepheline syenites, quartz-bearing syenites and alkaline volcanic rocks (i.e., phonolite and trachyte), with minor mafic dikes and carbonatitic veins. Laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) and secondary ion mass spectrometry (SIMS) zircon U-Pb dating gives consistent ages of 230-224 Ma for these rocks, suggesting that they are coeval. All alkaline rocks in the Saima complex are enriched in large ion lithophile elements (LILEs) and light rare earth elements (LREEs), and depleted in high field strength elements (HFSEs) with significant negative Nb, Ta and Ti anomalies. Geochemical data and Sr-Nd-Hf isotopic compositions indicate that the various alkaline rocks were all derived from partial melting of an ancient, re-enriched lithospheric mantle in the garnet stability field, but experienced variable siliceous- or carbonate-rich crustal contamination. Based on petrographic evidence, mineral compositions, and whole-rock geochemical data, two distinct magmatic evolutionary trends are proposed to explain the coeval emplacement of the various rock types within the Saima alkaline complex. The silica-undersaturated rocks (nepheline syenites and phonolites) result from alkali feldspar + apatite + titanite crystal fractionation of an alkaline mafic parental melt combined with assimilation of marine carbonate host rocks. In contrast, the generation of silica-saturated rocks (quartz-bearing syenites and trachytes) may be attributed to subsequent and continued clinopyroxene + apatite + biotite crystal fractionation coupled with assimilation of siliceous sediments.

  9. Studies on Dechlorination of DDT with Alkaline 2-propanol and Iron-Nickel (Fe-Ni) Catalyst.

    NASA Astrophysics Data System (ADS)

    Shareef, A.; Zaman, S. U.

    2009-05-01

    The Persistent Organic Pollutants (POPs) pesticides were previously extensively used in the cotton production and other agricultural activities in Pakistan and at least three thousand metric tons of obsolete pesticides have been stored under extreme hazardous conditions in more than thousand sites. Locally banned or severely restricted pesticides are easily available and DDT is continuously illegally imported and use in our country. Elimination of organochlorine pesticides (OCPs) waste has received considerable attention over the past two decades. Existing catalytic hydrodechlorinated techniques for disposing of OCPs are very costly due to the use of noble metals as catalysts. The aim of our study is to develop the cost effective and efficient method for the safe disposal of OCPs. This study is in continuation work on dechlorination of organochlorine pesticides with Fe-Ni catalyst in alkaline 2-propanol media. We turned our attention to the development of DDT disposal method for the third world countries. Herein, we report our first finding that in alkaline 2-propanol with Fe-Ni catalyst is an effective method for dechlorination of DDT. Catalytic dechlorination of DDT was carried out in an alkaline solution of NaOH and 2-propanol in the presence of catalyst at the temperature below 82 oC and end products were analyzed by using Gas Chromatography (GC-ECD) and Ion Chromatography (IC) techniques. Results obtained with initial concentration of DDT ranging between 10-100 μg/ml showed conversion of DDT to chlorine free product within 4 hrs.

  10. Mechanism of oxygen reduction reaction on Pt(111) in alkaline solution: Importance of chemisorbed water on surface

    DOE PAGES

    Liu, Shizhong; White, Michael G.; Liu, Ping

    2016-06-30

    Here, we report a detailed mechanistic study of the oxygen reduction reaction (ORR) on Pt(111) in alkaline solution, combining density functional theory and kinetic Monte Carlo simulations. A complex reaction network including four possible pathways via either 2e– or 4e– transfer is established and is able to reproduce the experimental measured polarization curve at both low- and high-potential regions. Our results show that it is essential to account for solvation by water and the dynamic coverage of *OH to describe the reaction kinetics well. In addition, a chemisorbed water (*H2O)-mediated mechanism including 4e– transfers is identified, where the reduction stepsmore » via *H2O on the surface are potential-independent and only the final removal of *OH from the surface in the form of OH–(aq) contributes to the current. For the ORR in alkaline solutions, such a mechanism is more competitive than the associative and dissociative mechanisms typically used to describe the ORR in acid solution. Finally, *OH and **O2 intermediates are found to be critically important for tuning the ORR activity of Pt in alkaline solution. To enhance the activity, the binding of Pt should be tuned in such a way that *OH binding is weak enough to release more surface sites under working conditions, while **O2 binding is strong enough to enable the ORR via the 4e– transfer mechanism.« less

  11. Martian alkaline basites chemically resemble basic rocks of the Lovozero alkaline massif, Kola peninsula

    NASA Astrophysics Data System (ADS)

    Kochemasov, G.

    The comparative wave planetology [1, 5] successfully overcomes the most principal martian test having now analyses of alkaline rocks from Columbia Hills [2, 3, 4]. This kind of rocks was predicted earlier on basis of the wave paradigm having stated that "the higher planetary relief range - the higher density difference between lithologies composing hypsometrically (tectonically) contrasting blocks [5]. This paradigm declares that "celestial bodies are dichotomic"(Theorem 1), "celestial bodies are sectoral" (Theorem 2), "celestial bodies are granular"(Theorem 3), "angular momenta of different level blocks tend to be equal" (Theorem 4)[1, 5]. Mars is a typical terrestrial planet but the farthest from Sun and thus with the smallest tide effects. Nevertheless it has the highest relief range and seems to be most distorted (ellipsoid in shape) and broken by deep fissures. The wave approach explains this by a warping action of standing waves of 4 ortho- and diagonal directions - they are the longest and highest in the martian case. These interfering warping waves caused by the elliptic keplerian orbits implying periodically changing accelerations and inertia-gravity forces produce inevitable tectonic dichotomy (the fundamental wave 1 long 2πR), sectoring (wave 2, πR, and other overtones), granulation. A granule size depends on an orbital frequency: the higher frequency the smaller granule. The Earth's granule, as a scale, is πR/4 (see it in NASA's PIA04159), Venus ` πR/6, Mercury's πR/16, Mars' πR/2 (the sizes are strictly tied to orb. fr.). Along with the granule sizes increase relief ranges ( Mercury ˜5 km, Venus 14, Earth 20, Mars ˜30) and compositional (density) difference between lowland and highland lithologies [5]. The lowland compositions become Fericher and denser: enstatite (Mercury), Mg-basalt (Venus), tholeiite (Earth), Fe-basalt (Mars). The highland compositions get less dense, lighter: anorthosite, alkaline basalt, andesite and conditional "albitite

  12. Alkaline replenisher evaluation for printed wiring board evaluation

    SciTech Connect

    Tucker, D.R.; Goldammer, S.E.

    1997-04-01

    MacDermid`s Metex{reg_sign} Ultra Etch FL and modifications to the Ultra Etch FL chemistry were evaluated as replacements of a discontinued replenisher, Ultra Etch Aqueous. Ultra Etch FL with additions of water to lower the total alkalinity and ammonium chloride to maintain the chloride level was found to produce acceptable results and, in fact, had a similar chemical composition to Ultra Etch Aqueous.

  13. Predicting Carbonate Ion Transport in Alkaline Anion Exchange Materials

    DTIC Science & Technology

    2012-01-01

    Schematic of the permeation cell experiment used to measure transient CO2 flux across the polymer electrolyte membrane. Experimental result vs. model trend...Microstructure on Charge Transfer, Mass Transfer, and Electrochemical Reactions in Solid Oxide Fuel Cells ; Part 2. Ion and Water Transport in Alkaline Anion...through the use of the Fuel Cell Technologies Test Station such as the relative humidity and flow rate of the feed gases, the cell temperature, and the

  14. Exposure to altered gravity conditions results in hypoxia-related enhancement of the presynaptic transporter-mediated release of glutamate.

    NASA Astrophysics Data System (ADS)

    Borisova, Tatiana

    High-affinity Na+-dependent glutamate transporters locate in the plasma membrane and maintain the low concentration of glutamate in synaptic cleft by the uptake of glutamate into neurons. Under hypoxic conditions glutamate transporters contribute to the glutamate release due to functioning in reverse mode. The release of glutamate via reverse-operated Na+-dependent glutamate transporters was investigated in brain synaptosomes under conditions of centrifugeinduced hypergravity. Flow cytometric analisis revealed similarity in the size and cytoplasmic granularity of control and hypergravity synaptosomes. Protonophore FCCP dissipates the proton gradient across synaptic vesicle thus synaptic vesicles are not able to keep glutamate inside. 1 microM FCCP induced the release of 4. 8 ±1. 0 % and 8. 0 ±1. 0 % of total accumulated synaptosomal label in control and G-loaded animals, respectively. Ca 2+-independent high- KCl stimulated L-[14C]glutamate release from synaptosomes preliminary treated with FCCP increased considerably from 27. 0 ± 2. 2 % to 35. 0 ± 2. 3 % after centrifuge-induced hypergravity. No-transportable inhibitor of glutamate transporter DL-threo-beta-benzyloxyaspartate was found to inhibit high-KCl and FCCP-stimulated release of L-[14C]glutamate, thus the release was concluded to occur due to reversal of glutamate transporters. We have also found the inhibition of the activity of Na \\ K ATPase in the plasma membrane of synaptosomes after hypergravity that might also contribute to the enhancement of the transporter-mediated release of glutamate. These hypergravity-induced alterations in the transporter-mediated release of glutamate were suggested to correlate with the hypoxic injury of neurons. The changes we have revealed for the transporter-mediated release of glutamate may lead to mental disorders, upcoming seizures and neurotoxicity under hypergravity conditions.

  15. TMC-1 Mediates Alkaline Sensation in C. elegans through Nociceptive Neurons.

    PubMed

    Wang, Xiang; Li, Guang; Liu, Jie; Liu, Jianfeng; Xu, X Z Shawn

    2016-07-06

    Noxious pH triggers pungent taste and nocifensive behavior. While the mechanisms underlying acidic pH sensation have been extensively characterized, little is known about how animals sense alkaline pH in the environment. TMC genes encode a family of evolutionarily conserved membrane proteins whose functions are largely unknown. Here, we characterize C. elegans TMC-1, which was suggested to form a Na(+)-sensitive channel mediating salt chemosensation. Interestingly, we find that TMC-1 is required for worms to avoid noxious alkaline environment. Alkaline pH evokes an inward current in nociceptive neurons, which is primarily mediated by TMC-1 and to a lesser extent by the TRP channel OSM-9. However, unlike OSM-9, which is sensitive to both acidic and alkaline pH, TMC-1 is only required for alkali-activated current, revealing a specificity for alkaline sensation. Ectopic expression of TMC-1 confers alkaline sensitivity to alkali-insensitive cells. Our results identify an unexpected role for TMCs in alkaline sensation and nociception.

  16. Peripartal changes in serum alkaline phosphatase activity and lactate dehydrogenase activity in dairy cows.

    PubMed Central

    Peter, A T; Bosu, W T; MacWilliams, P; Gallagher, S

    1987-01-01

    Peripartal serum alkaline phosphatase activity and lactate dehydrogenase activity were measured in 30 dairy cows in order to examine the association between retained fetal membranes and enzyme activity. Daily blood samples were obtained from pregnant cows, starting 15 days before the expected day of calving until eight days after parturition. Sera from 15 cows which retained fetal membranes longer than 24 hours and 15 cows which shed fetal membranes within six hours after parturition were analyzed for alkaline phosphatase and lactate dehydrogenase enzyme activities. Mean alkaline phosphatase enzyme activities ranged from 15.93 to 32.6 U/L in retained and nonretained placenta cows. There was a trend towards higher serum alkaline phosphatase activities in retained placenta cows but the differences were not significant among the groups (P greater than 0.05). Mean lactate dehydrogenase activities ranged from 307.2 to 438.86 U/L in nonretained and retained placenta cows. Lactate dehydrogenase enzyme activities in nonretained and retained placenta cows were similar (P greater than 0.05). The alkaline phosphatase and lactate dehydrogenase enzyme activities peaked at the time of parturition in both groups. However, the differences in alkaline phosphatase and lactate dehydrogenase activities on different days within non-retained and retained placenta cows were significant (P less than 0.05). Results indicate that prepartal changes in alkaline phosphatase and lactate dehydrogenase enzyme activities are not predictive of placental retention postpartum. PMID:3453274

  17. Sensitivity of UV Erythemal Radiation to Total Ozone Changes under Different Sky Conditions: Results for Granada, Spain.

    PubMed

    Antón, Manuel; Cazorla, Alberto; Mateos, David; Costa, Maria J; Olmo, Francisco J; Alados-Arboledas, Lucas

    2016-01-01

    This study focuses on the analysis of the sensitivity of UV erythemal radiation (UVER) to variations in the total ozone column (TOC) under different sky conditions at Granada (southeastern Spain). The sensitivity is studied both in relative terms by means of the Radiation Amplification Factor (RAF) and in absolute terms using the Ozone Efficiency (OE). These two variables are determined for diverse sky conditions characterized by the cloud cover information given by a sky camera (in oktas) and the cloud optical depth (COD) estimated from global solar radiation measurements. As expected, in absolute terms, the TOC variations cause substantially smaller UVER changes during completely overcast situations than during cloud-free cases. For instance, the OE (SZA = 30°, TOC = 290 DU) decreases from 0.68 mW m(-2) per unit of TOC (0 oktas) to 0.50 mW m(-2) per unit of TOC (8 oktas). However, the opposite is observed when the analysis is performed in relative terms. Thus, the RAF (determined for SZA cases below 80°) increases from 1.1 for cloud-free cases (0 oktas) to 1.4 for completely overcast situations (8 oktas). This opposite behavior is also found when both RAF and OE are analyzed as functions of COD. Thus, while the OE strongly decreases with increasing COD, the RAF increases as COD increases.

  18. A Flight Evaluation of an Airborne Physiological Instrumentation System, Including Preliminary Results Under Conditions of Varying Accelerations

    NASA Technical Reports Server (NTRS)

    Smedal, Harald A.; Holden, George R.; Smith, Joseph R., Jr.

    1960-01-01

    A physiological instrumentation system capable of recording the electrocardiogram, pulse rate, respiration rate, and systolic and diastolic blood pressures during flight has been developed. This instrumentation system was designed for use during control studies at varied levels of acceleration in order to monitor the well-being of the pilot and at the same time to obtain data for study of the relationships between his various physiological functions and his performance capability. Flights, made in a T-33 aircraft, demonstrated the ability of the system to obtain the desired physiological data in flight. The data obtained in these flights, although limited in nature, indicate a slowing of the pulse rate under the subgravity conditions of brief duration. There appeared to be a proportional nearly in-phase relationship between pulse rate and acceleration. A decrease in diastolic blood pressure together with an increase in pulse pressure was noted during subgravity conditions and an elevation of the diastolic pressure together with a decrease in pulse pressure du-ring increased accelerations. No change worthy of note was seen in the records of the systolic blood pressure, the respiration rate, or the electrocardiogram over the range of acceleration studied (0 to 3 g).

  19. K Basin Sludge Conditioning Process Testing Project Results from Test 4, ''Acid Digestion of Mixed-Bed Ion Exchange Resin''

    SciTech Connect

    Pool, K.H.; Delegard, C.H.; Schmidt, A.J.; Thornton, B.M.; Silvers, K.L.

    1999-04-02

    Approximately 73 m{sup 3} of heterogeneous solid material, ''sludge,'' (upper bound estimate, Packer 1997) have accumulated at the bottom of the K Basins in the 100 K Area of the Hanford Site. This sludge is a mixture of spent fuel element corrosion products, ion exchange materials (organic and inorganic), graphite-based gasket materials, iron and aluminum metal corrosion products, sand, and debris (Makenas et al. 1996, 1997). In addition, small amounts of polychlorinated biphenyls (PCBs) have been found. Ultimately, it is planned to transfer the K Basins sludge to the Hanford double shell tanks (DSTs). The Hanford Spent Nuclear Fuel (HSNF) project has conducted a number of evaluations to examine technology and processing alternatives to pretreat K Basin sludge to meet storage and disposal requirements. From these evaluations, chemical pretreatment has been selected to address criticality issues, reactivity, and the destruction or removal of PCBs before the K Basin sludge can be transferred to the DSTs. Chemical pretreatment, referred to as the K Basin sludge conditioning process, includes nitric acid dissolution of the sludge (with removal of acid insoluble solids), neutrons absorber addition, neutralization, and reprecipitation. Laboratory testing is being conducted by the Pacific Northwest National Laboratory (PNNL) to provide data necessary to develop the sludge conditioning process.

  20. Identification of human pulmonary alkaline phosphatase isoenzymes.

    PubMed

    Capelli, A; Cerutti, C G; Lusuardi, M; Donner, C F

    1997-04-01

    An increase of alkaline phosphatase (ALP) activity has been observed in the bronchoalveolar lavage fluid (BALF) of patients affected by pulmonary fibrosis in chronic interstitial lung disorders. To characterize the ALP isoenzymes in such cases, we used gel filtration, agarose gel electrophoresis, heat and amino acid inhibition assays, wheat-germ agglutinin (WGA) precipitation, and an immunoassay specific for the bone-isoform of ALP. Only one anodic band representing a high-molecular-weight isoform of ALP (Mr approximately 2,000 kDa) was observed on electrophoresis of BALF. The inhibition assay results were consistent for a tissue-nonspecific isoenzyme sensitive to a temperature of 56 degrees C (71.9 +/- 2.5% inhibition) and to homoarginine (65.7 +/- 1.9%), and resistant to L-phenylalanine and L-leucine. Less than 13% of ALP activity was heat-stable. After incubation of BALF specimens with glycosyl-phosphatidylinositol-phospholipase D plus Nonidet P-40, or with phosphatidylinositol-phospholipase C alone, an electrophoretic cathodic band (Mr approximately 220 kDa) appeared near the bone band of a standard serum. With the WGA assay, 84.4 +/- 3.3% of ALP precipitated and the band disappeared. After immunoassay for the bone isoform, a mean of less than 5% enzyme activity was measured. We conclude that the ALP found in BALF is a pulmonary isoform of a tissue nonspecific isoenzyme.

  1. Production of alkaline protease from Cellulosimicrobium cellulans

    PubMed Central

    Ferracini-Santos, Luciana; Sato, Hélia H

    2009-01-01

    Cellulosimicrobium cellulans is one of the microorganisms that produces a wide variety of yeast cell wall-degrading enzymes, β-1,3-glucanase, protease and chitinase. Dried cells of Saccharomyces cerevisiae were used as carbon and nitrogen source for cell growth and protease production. The medium components KH2PO4, KOH and dried yeast cells showed a significant effect (p<0.05) on the factorial fractional design. A second design was prepared using two factors: pH and percentage of dried yeast cells. The results showed that the culture medium for the maximum production of protease was 0.2 g/l of MgSO4.7H2O, 2.0 g/l of (NH4)2SO4 and 8% of dried yeast cells in 0.15M phosphate buffer at pH 8.0. The maximum alkaline protease production was 7.0 ± 0.27 U/ml over the center point. Crude protease showed best activity at 50ºC and pH 7.0-8.0, and was stable at 50ºC. PMID:24031317

  2. The Martian ocean: First acid, then alkaline

    NASA Technical Reports Server (NTRS)

    Schaefer, M. W.

    1992-01-01

    In Mars' distant past, carbon dioxide and water may have been plentiful. Values of total outgassed CO2 from several to about 10 bar are consistent with present knowledge, and this amount of CO2 implies an amount of water outgassed equal to an equivalent depth of 500 to 1000 m. It is quite reasonable, therefore, to envision an early Mars in which there was a body or bodies of liquid water, perhaps in the northern plains, and a dense carbon dioxide atmosphere. Under such conditions, the pH of the water will be low, due to the dissolution of carbon dioxide in the water to form carbonic acid. This acidic water is capable of weathering the available rock quite intensely, particularly because this rock is likely to be heavily fractured (from meteorite bombardment) or even consist of fine particles (such as pyroclastic deposits). As time goes on, however, the carbon dioxide atmosphere will rapidly pass through the ocean to form carbonate deposits. As the density of the atmosphere decreases, so will the flux of carbonic acid into the ocean. Without this input of carbonic acid, the effect of the dissolved weathering products will be to increase the pH of the water. The ocean will then become alkaline. To study this process, I have developed a geochemical cycle model for the atmosphere-hydrosphere-regolith system of Mars. The treatment of geochemical cycles as complex kinetic chemical reactions has been undertaken for terrestrial systems in recent years with much success. This method is capable of elegantly handling the interactions between the simultaneous chemical reactions needed to understand such a system.

  3. Used Nuclear Fuel Loading and Structural Performance Under Normal Conditions of Transport- Demonstration of Approach and Results on Used Fuel Performance Characterization

    SciTech Connect

    Adkins, Harold; Geelhood, Ken; Koeppel, Brian; Coleman, Justin; Bignell, John; Flores, Gregg; Wang, Jy-An; Sanborn, Scott; Spears, Robert; Klymyshyn, Nick

    2013-09-30

    This document addresses Oak Ridge National Laboratory milestone M2FT-13OR0822015 Demonstration of Approach and Results on Used Nuclear Fuel Performance Characterization. This report provides results of the initial demonstration of the modeling capability developed to perform preliminary deterministic evaluations of moderate-to-high burnup used nuclear fuel (UNF) mechanical performance under normal conditions of storage (NCS) and normal conditions of transport (NCT) conditions. This report also provides results from the sensitivity studies that have been performed. Finally, discussion on the long-term goals and objectives of this initiative are provided.

  4. Preliminary Results Of Hydrodynamic Responses To Ship Movements And Weather Conditions Along The Coastal Walls Of Shallow Areas

    NASA Astrophysics Data System (ADS)

    Acar, Dursun; Alpar, Bedri; Cagatay, Namık; Ozeren, Sinan; Sarı, Erol; Eris, Kadir; Vardar, Denizhan; Arslan, Tugce; Basegmez, Koray

    2016-04-01

    Water-level variations in coastal areas and shallow channels take place under the influence of more complex factors, compared to those in deeper areas. Atmospheric pressure, wind, and wave interactions with bottom morphological characteristics are some important natural features while human-induced factors are usually maritime traffic and manoeuvres the ships. While weather conditions cause long-term changes in water level, water level interactions in near shore areas, can occur very quickly depending on the ship manoeuvres and squat characteristics, and these rapid changes can lead to unpredictable water level lowering. Such rapid changes may cause various dangerous incidents and ship accidents, particularly in areas where rapid water oscillations occur. Improper calculations of propulsion power or orientation of the ship body, especially in the areas where geological and morphological characteristics permit fast water movements, are the most important additional causes of accidents due to sudden water level decreases. For an example, even though a 200-m-long vessel can complete its 35° rotation in a circular area with radius of 250 m, if it is calm and sufficiently deep, this diameter increases 5 times at the shallow waters also depending on the hydrodynamic flow conditions. In 2005, "Gerardus Mercator" has bumped into the inside bottom wall of the channel with a low speed (4 knots) turn of when she had just made a 200° turn. Seven years later the cruise ship "Costa Concordia" struck a rock, before she drifted and grounded, in the calm seas of the coast of Isola del Giglio in Italy, due to a combined effects of waves generated by side waves of ship manoeuvres, atmospheric pressure and squat specifications as well. The waves reflected from the seawalls complicate the navigation problems which should be examined in detail. Thus, three prototype models with various angular seawall features were prepared, simple in shape with perpendicular and sloped seawalls with

  5. Biological impacts of enhanced alkalinity in Carcinus maenas.

    PubMed

    Cripps, Gemma; Widdicombe, Stephen; Spicer, John I; Findlay, Helen S

    2013-06-15

    Further steps are needed to establish feasible alleviation strategies that are able to reduce the impacts of ocean acidification, whilst ensuring minimal biological side-effects in the process. Whilst there is a growing body of literature on the biological impacts of many other carbon dioxide reduction techniques, seemingly little is known about enhanced alkalinity. For this reason, we investigated the potential physiological impacts of using chemical sequestration as an alleviation strategy. In a controlled experiment, Carcinus maenas were acutely exposed to concentrations of Ca(OH)2 that would be required to reverse the decline in ocean surface pH and return it to pre-industrial levels. Acute exposure significantly affected all individuals' acid-base balance resulting in slight respiratory alkalosis and hyperkalemia, which was strongest in mature females. Although the trigger for both of these responses is currently unclear, this study has shown that alkalinity addition does alter acid-base balance in this comparatively robust crustacean species.

  6. Theoretical study of the alkali and alkaline-earth monosulfides

    NASA Technical Reports Server (NTRS)

    Partridge, Harry; Langhoff, Stephen R.; Bauschlicher, Charles W., Jr.

    1988-01-01

    Ab initio calculations have been used to obtain accurate spectroscopic constants for the X2Pi and A2Sigma(+) states of the alkali sulfides and the X1Sigma(+), a3Pi, and A1Pi states of the alkaline-earth sulfides. In contrast to the alkali oxides, the alkali sulfides are found to have X2Pi ground states, due to the larger electrostatic interaction. Dissociation energies of 3.27 eV for BeS, 2.32 eV for MgS, 3.29 eV for CaS, and 3.41 eV for SrS have been obtained for the X1Sigma(+) states of the alkaline-earth sulfides, in good agreement with experimental results. Core correlation is shown to increase the Te values for the a3Pi and A1Pi states of MgS, CaS, and SrS.

  7. Ion association in concentrated NaCI brines from ambient to supercritical conditions: results from classical molecular dynamics simulations

    PubMed Central

    Sherman, David M; Collings, Matthew D

    2002-01-01

    Highly concentrated NaCl brines are important geothermal fluids; chloride complexation of metals in such brines increases the solubility of minerals and plays a fundamental role in the genesis of hydrothermal ore deposits. There is experimental evidence that the molecular nature of the NaCl–water system changes over the pressure–temperature range of the Earth's crust. A transition of concentrated NaCl–H2O brines to a "hydrous molten salt" at high P and T has been argued to stabilize an aqueous fluid phase in the deep crust. In this work, we have done molecular dynamic simulations using classical potentials to determine the nature of concentrated (0.5–16 m) NaCl–water mixtures under ambient (25°C, 1 bar), hydrothermal (325°C, 1 kbar) and deep crustal (625°C, 15 kbar) conditions. We used the well-established SPCE model for water together with the Smith and Dang Lennard-Jones potentials for the ions (J. Chem. Phys., 1994, 100, 3757). With increasing temperature at 1 kbar, the dielectric constant of water decreases to give extensive ion-association and the formation of polyatomic (NanClm)n-m clusters in addition to simple NaCl ion pairs. Large polyatomic (NanClm)n-m clusters resemble what would be expected in a hydrous NaCl melt in which water and NaCl were completely miscible. Although ion association decreases with pressure, temperatures of 625°C are not enough to overcome pressures of 15 kbar; consequently, there is still enhanced Na–Cl association in brines under deep crustal conditions.

  8. The photoprotective role of spermidine in tomato seedlings under salinity-alkalinity stress.

    PubMed

    Hu, Lipan; Xiang, Lixia; Zhang, Li; Zhou, Xiaoting; Zou, Zhirong; Hu, Xiaohui

    2014-01-01

    Polyamines are small, ubiquitous, nitrogenous compounds that scavenge reactive oxygen species and stabilize the structure and function of the photosynthetic apparatus in response to abiotic stresses. Molecular details underlying polyamine-mediated photoprotective mechanisms are not completely resolved. This study investigated the role of spermidine (Spd) in the structure and function of the photosynthetic apparatus. Tomato seedlings were subjected to salinity-alkalinity stress with and without foliar application of Spd, and photosynthetic and morphological parameters were analyzed. Leaf dry weight and net photosynthetic rate were reduced by salinity-alkalinity stress. Salinity-alkalinity stress reduced photochemical quenching parameters, including maximum photochemistry efficiency of photosystem II, quantum yield of linear electron flux, and coefficient of photochemical quenching (qP). Salinity-alkalinity stress elevated nonphotochemical quenching parameters, including the de-epoxidation state of the xanthophyll cycle and nonphotochemical quenching (NPQ). Microscopic analysis revealed that salinity-alkalinity stress disrupted the internal lamellar system of granal and stromal thylakoids. Exogenous Spd alleviated the stress-induced reduction of leaf dry weight, net photosynthetic rate, and qP parameters. The NPQ parameters increased by salinity-alkalinity stress were also alleviated by Spd. Seedlings treated with exogenous Spd had higher zeaxanthin (Z) contents than those without Spd under salinity-alkalinity stress. The chloroplast ultrastructure had a more ordered arrangement in seedlings treated with exogenous Spd than in those without Spd under salinity-alkalinity stress. These results indicate that exogenous Spd can alleviate the growth inhibition and thylakoid membrane photodamage caused by salinity-alkalinity stress. The Spd-induced accumulation of Z also may have an important role in stabilizing the photosynthetic apparatus.

  9. Chemical nature of alkaline polyphosphate boundary film at heated rubbing surfaces

    NASA Astrophysics Data System (ADS)

    Wan, Shanhong; Tieu, A. Kiet; Zhu, Qiang; Zhu, Hongtao; Cui, Shaogang; Mitchell, David R. G.; Kong, Charlie; Cowie, Bruce; Denman, John A.; Liu, Rong

    2016-05-01

    Alkaline polyphosphate has been demonstrated to be able to reduce significant wear and friction of sliding interfaces under heavy loads (>1 GPa) and elevated temperature (800 °C and above) conditions, e.g. hot metal manufacturing. The chemical composition and fine structure of polyphosphate lubricating film is not well understood as well as the role of alkaline elements within the reaction film at hot rubbing surface. This work makes use of the coupling surface analytical techniques on the alkaline polyphosphate tribofilm, XANES, TOF-SIMS and FIB/TEM. The data show the composition in gradient distribution and trilaminar structure of tribofilm: a shorter chain phosphate overlying a long chain polyphosphate that adheres onto oxide steel base through a short chain phosphate. The chemical hardness model well explains the anti-abrasive mechanism of alkaline polyphosphate at elevated temperatures and also predicts a depolymerisation and simultaneous cross-linking of the polyphosphate glass. The role of alkaline elements in the lubrication mechanism is especially explained. This work firstly serves as a basis for a detailed study of alkaline polyphosphate tribofilm at temperature over 600 °C.

  10. Chemical nature of alkaline polyphosphate boundary film at heated rubbing surfaces

    PubMed Central

    Wan, Shanhong; Tieu, A. Kiet; Zhu, Qiang; Zhu, Hongtao; Cui, Shaogang; Mitchell, David R. G.; Kong, Charlie; Cowie, Bruce; Denman, John A.; Liu, Rong

    2016-01-01

    Alkaline polyphosphate has been demonstrated to be able to reduce significant wear and friction of sliding interfaces under heavy loads (>1 GPa) and elevated temperature (800 °C and above) conditions, e.g. hot metal manufacturing. The chemical composition and fine structure of polyphosphate lubricating film is not well understood as well as the role of alkaline elements within the reaction film at hot rubbing surface. This work makes use of the coupling surface analytical techniques on the alkaline polyphosphate tribofilm, XANES, TOF-SIMS and FIB/TEM. The data show the composition in gradient distribution and trilaminar structure of tribofilm: a shorter chain phosphate overlying a long chain polyphosphate that adheres onto oxide steel base through a short chain phosphate. The chemical hardness model well explains the anti-abrasive mechanism of alkaline polyphosphate at elevated temperatures and also predicts a depolymerisation and simultaneous cross-linking of the polyphosphate glass. The role of alkaline elements in the lubrication mechanism is especially explained. This work firstly serves as a basis for a detailed study of alkaline polyphosphate tribofilm at temperature over 600 °C. PMID:27180956

  11. Poly(vinyl chloride) tubing with covalently bound alkaline phosphatase and alternative approach for investigations of open-tubular bioreactors.

    PubMed

    Rozum, Beata; Gajownik, Kamil; Tymecki, Lukasz; Koncki, Robert

    2010-05-01

    A one-step carbodiimide method was found to allow covalent binding of enzymes to the inner wall of poly(vinyl chloride) (PVC) tubing. The immobilization is performed under mild conditions without laborious pretreatment or activation of reactor surface. In these preliminary studies, alkaline phosphatase (ALP, EC 3.1.3.1) and p-nitrophenyl phosphate (NPP) were applied as a model enzyme and substrate, respectively. The resulting open-tubular bioreactor exhibits satisfactory operational and storage stability. In addition, a novel and very simple instrumental concept for optical monitoring of the biocatalytic process directly inside the microbioreactor using a system of paired emitter-detector diodes is presented.

  12. A newly high alkaline lipase: an ideal choice for application in detergent formulations

    PubMed Central

    2011-01-01

    Background Bacterial lipases received much attention for their substrate specificity and their ability to function in extreme environments (pH, temperature...). Many staphylococci produced lipases which were released into the culture medium. Reports of thermostable lipases from Staphylococcus sp. and active in alkaline conditions are not previously described. Results A newly soil-isolated Staphylococcus sp. strain ESW secretes an induced lipase in the culture medium. The effects of temperature, pH and various components in a detergent on the activity and stability of Staphylococcus sp. lipase (SL1) were studied in a preliminary evaluation for use in detergent formulation solutions. The enzyme was highly active over a wide range of pH from 9.0 to 13.0, with an optimum at pH 12.0. The relative activity at pH 13.0 was about 60% of that obtained at pH 12.0. It exhibited maximal activity at 60°C. This novel lipase, showed extreme stability towards non-ionic and anionic surfactants after pre-incubation for 1 h at 40°C, and relative stability towards oxidizing agents. Additionally, the crude enzyme showed excellent stability and compatibility with various commercial solid and liquid detergents. Conclusions These properties added to the high activity in high alkaline pH make this novel lipase an ideal choice for application in detergent formulations. PMID:22123072

  13. One-step electrosynthesis of ethylene and ethanol from CO2 in an alkaline electrolyzer

    NASA Astrophysics Data System (ADS)

    Ma, Sichao; Sadakiyo, Masaaki; Luo, Raymond; Heima, Minako; Yamauchi, Miho; Kenis, Paul J. A.

    2016-01-01

    Electroreduction of CO2 has potential for storing otherwise wasted intermittent renewable energy, while reducing emission of CO2 into the atmosphere. Identifying robust and efficient electrocatalysts and associated optimum operating conditions to produce hydrocarbons at high energetic efficiency (low overpotential) remains a challenge. In this study, four Cu nanoparticle catalysts of different morphology and composition (amount of surface oxide) are synthesized and their activities towards CO2 reduction are characterized in an alkaline electrolyzer. Use of catalysts with large surface roughness results in a combined Faradaic efficiency (46%) for the electroreduction of CO2 to ethylene and ethanol in combination with current densities of ∼200 mA cm-2, a 10-fold increase in performance achieved at much lower overpotential (only < 0.7 V) compared to prior work. Compared to prior work, the high production levels of ethylene and ethanol can be attributed mainly to the use of alkaline electrolyte to improve kinetics and the suppressed evolution of H2, as well as the application of gas diffusion electrodes covered with active and rough Cu nanoparticles in the electrolyzer. These high performance levels and the gained fundamental understanding on Cu-based catalysts bring electrochemical reduction processes such as presented here closer to practical application.

  14. Alkaline phosphatase in osteoblasts is down-regulated by pulsatile fluid flow

    NASA Technical Reports Server (NTRS)

    Hillsley, M. V.; Frangos, J. A.

    1997-01-01

    It is our hypothesis that interstitial fluid flow plays a role in the bone remodeling response to mechanical loading. The fluid flow-induced expression of three proteins (collagen, osteopontin, and alkaline phosphatase) involved in bone remodeling was investigated. Rat calvarial osteoblasts subjected to pulsatile fluid flow at an average shear stress of 5 dyne/cm2 showed decreased alkaline phosphatase (AP) mRNA expression after only 1 hour of flow. After 3 hours of flow, AP mRNA levels had decreased to 30% of stationary control levels and remained at this level for an additional 5 hours of flow. Steady flow (4 dyne/cm2 fluid shear stress), in contrast, resulted in a delayed and less dramatic decrease in AP mRNA expression to 63% of control levels after 8 hours of flow. The reduced AP mRNA expression under pulsatile flow conditions was followed by reduced AP enzyme activity after 24 hours. No changes in collagen or osteopontin mRNA expression were detected over 8 hours of pulsatile flow. This is the first time fluid flow has been shown to affect gene expression in osteoblasts.

  15. Electrochemical kinetic and mass transfer model for direct ethanol alkaline fuel cell (DEAFC)

    NASA Astrophysics Data System (ADS)

    Abdullah, S.; Kamarudin, S. K.; Hasran, U. A.; Masdar, M. S.; Daud, W. R. W.

    2016-07-01

    A mathematical model is developed for a liquid-feed DEAFC incorporating an alkaline anion-exchange membrane. The one-dimensional mass transport of chemical species is modelled using isothermal, single-phase and steady-state assumptions. The anode and cathode electrochemical reactions use the Tafel kinetics approach, with two limiting cases, for the reaction order. The model fully accounts for the mixed potential effects of ethanol oxidation at the cathode due to ethanol crossover via an alkaline anion-exchange membrane. In contrast to a polymer electrolyte membrane model, the current model considers the flux of ethanol at the membrane as the difference between diffusive and electroosmotic effects. The model is used to investigate the effects of the ethanol and alkali inlet feed concentrations at the anode. The model predicts that the cell performance is almost identical for different ethanol concentrations at a low current density. Moreover, the model results show that feeding the DEAFC with 5 M NaOH and 3 M ethanol at specific operating conditions yields a better performance at a higher current density. Furthermore, the model indicates that crossover effects on the DEAFC performance are significant. The cell performance decrease from its theoretical value when a parasitic current is enabled in the model.

  16. Direct Hydrothermal Precipitation of Pyrochlore-Type Tungsten Trioxide Hemihydrate from Alkaline Sodium Tungstate Solution

    NASA Astrophysics Data System (ADS)

    Li, Xiaobin; Li, Jianpu; Zhou, Qiusheng; Peng, Zhihong; Liu, Guihua; Qi, Tiangui

    2012-04-01

    Pyrochlore-type tungsten trioxide hemihydrate (WO3·0.5H2O) powder with the average particle size of 0.5 μm was prepared successfully from the weak alkaline sodium tungstate solution by using organic substances of sucrose or cisbutenedioic acid as the acidification agent. The influences of solution pH and acidification agents on the precipitation process were investigated. The results showed that organic acidification agents such as sucrose and cisbutenedioic acid could improve the precipitation of pyrochlore WO3·0.5H2O greatly from sodium tungstate solution compared with the traditional acidification agent of hydrochloric acid. In addition, the pH value of the hydrothermal system played a critical role in the precipitation process of WO3·0.5H2O, and WO3·0.5H2O precipitation mainly occured in the pH range of 7.0 to 8.5. The precipitation rate of tungsten species in the sodium tungstate solution could reach up to 98 pct under the optimized hydrothermal conditions. This article proposed also the hydrothermal precipitation mechanism of WO3·0.5H2O from the weak alkaline sodium tungstate solution. The novel method reported in this study has a great potential to improve the efficiency of advanced tungsten trioxide-based functional material preparation, as well as for the pollution-reducing and energy-saving tungsten extractive metallurgy.

  17. Extracting Vanadium from Stone Coal by a Cyclic Alkaline Leaching Method

    NASA Astrophysics Data System (ADS)

    Hu, Kailong; Liu, Xuheng; Li, Qinggang

    2017-04-01

    In order to achieve an efficient and economical approach on extracting vanadium from stone coal, a cyclic alkaline leaching method was studied in this work. The effects of operating parameters, including the NaOH concentration, temperature, reaction time, and liquid-solid ratio, on vanadium leaching efficiency were investigated. Also, we studied the influence of caustic soda dosage on the cyclic leaching process as well as the effect of increasing ionic strength in leachates and wash water. The results show that this method achieved a 51 pct decrease of the dosage of caustic soda under the optimized conditions compared with the single-step alkaline leaching. The average leaching yield of vanadium reached 82.28 pct. The leachates and wash water in each leaching cycle were utilized for the next leaching cycle, achieving the recycling of alkali as well as waste water. During the cyclic process, the volume of water was not increased, which markedly reduces the discharge of waste water and is also beneficial in terms of cost reduction.

  18. Alkaline pretreatment methods followed by acid hydrolysis of Saccharum spontaneum for bioethanol production.

    PubMed

    Chaudhary, Gaurav; Singh, Lalit Kumar; Ghosh, Sanjoy

    2012-11-01

    Different alkaline pretreatment methods (NaOH, NaOH+10% urea and aqueous ammonia) were optimized for maximum delignification of Saccharum spontaneum at 30°C. Maximum delignification were obtained as 47.8%, 51% and 48% from NaOH (7% NaOH, 48h, and 10% biomass loading), NaOH+urea (7% NaOH+10% urea, 48 h and 10% biomass loading) and 30% ammonia (40 days and 10% biomass loading) respectively. H(2)SO(4) 60% (v/v), 10% biomass loading at 30°C for 4h, were optimized conditions to solubilize the cellulose and hemicellulose from solid residue obtained after different optimized alkaline pretreatments. Slurry thus obtained was diluted to obtain final acid concentration of 10% (v/v) for real hydrolysis of cellulose and hemicellulose at 100°C for 1h. Among all pretreatment methods applied, the best result 0.58 g (85%) reducing sugars/g of initial biomass after acid hydrolysis was obtained from aqueous ammonia pretreated biomass. Scheffersomyces stipitis CBS6054 was used to ferment the hydrolysate; ethanol yield (Y(p/s)) and productivity (r(p)) were found to be 0.35 g/g and 0.22 g/L/h respectively.

  19. Structural elucidation of sorghum lignins from an integrated biorefinery process based on hydrothermal and alkaline treatments.

    PubMed

    Sun, Shao-Long; Wen, Jia-Long; Ma, Ming-Guo; Sun, Run-Cang

    2014-08-13

    An integrated process based on hydrothermal pretreatment (HTP) (i.e., 110-230 °C, 0.5-2.0 h) and alkaline post-treatment (2% NaOH at 90 °C for 2.0 h) has been performed for the production of xylooligosaccharide, lignin, and digestible substrate from sweet sorghum stems. The yield, purity, dissociation mechanisms, structural features, and structural transformations of alkali lignins obtained from the integrated process were investigated. It was found that the HTP process facilitated the subsequent alkaline delignification, releasing lignin with the highest yield (79.3%) and purity from the HTP residue obtained at 190 °C for 0.5 h. All of the results indicated that the cleavage of the β-O-4 linkages and degradation of β-β and β-5 linkages occurred under the harsh HTP conditions. Depolymerization and condensation reactions simultaneously occurred at higher temperatures (≥ 170 °C). Moreover, the thermostability of lignin was positively related to its molecular weight, but was also affected by the inherent structures, such as β-O-4 linkages and condensed units. These findings will enhance the understanding of structural transformations of the lignins during the integrated process and maximize the potential utilizations of the lignins in a current biorefinery process.

  20. Plutonium(IV) precipitates formed in alkaline media in the presence of various anions

    SciTech Connect

    Krot, N.N.; Shilov, V.P.; Yusov, A.B.; Tananaev, I.G.; Grigoriev, M.S.; Garnov, A.Yu.; Perminov, V.P.; Astafurova, L.N.

    1998-09-01

    The tendency of Pu(IV) to hydrolyze and form true solutions, colloid solutions, or insoluble precipitates has been known since the Manhattan Project. Since then, specific studies have been performed to examine in detail the equilibria of Pu(IV) hydrolytic reactions in various media. Great attention also has been paid to the preparation, structure, and properties of Pu(IV) polymers or colloids. These compounds found an important application in sol-gel technology for the preparation of nuclear fuel materials. A most important result of these works was the conclusion that Pu(IV) hydroxide, after some aging, consists of very small PuO{sub 2} crystallites and should therefore be considered to be Pu(IV) hydrous oxide. However, studies of the properties and behavior of solid Pu(IV) hydroxide in complex heterogeneous systems are rare. The primary goal of this investigation was to obtain data on the composition and properties of Pu(IV) hydrous oxide or other compounds formed in alkaline media under different conditions. Such information is important to understand Pu(IV) behavior and the forms of its existence in the Hanford Site alkaline tank waste sludge. This knowledge then may be applied in assessing plutonium criticality hazards in the storage, retrieval, and treatment of Hanford Site tank wastes as well as in understanding its contribution to the transuranic waste inventory (threshold at 100 nCi/g or about 5 {times} 10{sup {minus}6} M) of the separate solution and solid phases.