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Sample records for alkaline medium peliculas

  1. Study of niobium corrosion in alkaline medium

    International Nuclear Information System (INIS)

    Almeida, S.H. de.

    1987-01-01

    A comparative study of niobium electrochemical behaviour in NaOH and KOH solution, with concentrations between 0,5 and 6,1M is presented. The studies were done through electrochemicals assays, consisting in the corrosion potential and anodic and cathodic polarization curves, complemented by loss of mass experiments. The niobium anodic behaviour in alkaline medium is characterized by passivation occurrence, with a stable film formation. The Na oH solution in alkaline medium are more corrosible to niobium than the KOH solution. The loss of mass assays showed that the corrosion velocit is more dependente of hydroxide concentration in KOH medium than the NaOH medium. (C.G.C.) [pt

  2. Kinetics and mechanism of oxidation of tellurium (IV) by periodate in alkaline medium

    International Nuclear Information System (INIS)

    Srinivas, K.; Vani, P.; Dikshitulu, L.S.A.

    1995-01-01

    Detailed kinetic study of the oxidation of tellurium (IV) by periodate in alkaline medium has been carried out to compare the mechanisms of oxidation in the acid and alkaline media. It is interesting to note that the rate step involves a two-electron transfer from tellurium (IV) to periodate in alkaline medium although the kinetic pattern is somewhat different from that in the acid medium. 7 refs., 1 tab

  3. Microwave activation of palladium nanoparticles for enhanced ethanol electrocatalytic oxidation reaction in alkaline medium

    CSIR Research Space (South Africa)

    Rohwer, MB

    2015-02-01

    Full Text Available in alkaline medium (in terms of high mass activity stability and fast reaction kinetics). The remarkable microwave-induced properties on the Pd catalyst promise to revolutionize the use of microwave for catalyst activation for enhanced heterogeneous catalysis...

  4. Effect of Medium Composition on Commercially Important Alkaline Protease Production by Bacillus licheniformis N-2

    Directory of Open Access Journals (Sweden)

    Javed Iqbal Qazi

    2008-01-01

    Full Text Available Protease production by alkalophilic B. licheniformis N-2 was investigated in 50 mL of the growth medium consisting of (in g/L: glucose 10.0, soybean meal 10.0, K2HPO4 3.0, MgSO4·7H2O 0.5, NaCl 0.5 and CaCl2·2H2O 0.5 at pH=10. Different carbon and nitrogen sources in the form of fine powder of organic, inorganic and defatted meals were studied to select the suitable substrate for alkaline protease production. The highest level of alkaline protease (677.64 U/mL was obtained in the medium containing glucose followed by soluble starch and wheat bran. Among various nitrogen sources, defatted soybean meal was found to be the best inducer of alkaline protease, while inorganic nitrogen sources in the form of ammonium salts repressed the enzyme activity up to 96 %. Thermostability studies showed that the enzyme in the presence of 10 mM Ca2+ ions retained its residual activity up to 80 % even after incubation at 40 °C for 12 h. The enzyme was found stable over a broad range of pH (8–11 and lost 52 % of its residual activity at pH=12. After the treatment with Tween 20, Tween 45, Tween 65, Triton X-405, H2O2 and sodium perborate, each at 1.0 % concentration, the enzyme showed residual activity of 105, 82, 116, 109, 135 and 126 %, respectively. The application of alkaline protease for removal of blood stains from cotton fabric also indicates its potential use in detergent formulations.

  5. Spectroscopic and mechanistic investigations into oxidation of aspartame by diperiodatocuprate(III in aqueous alkaline medium

    Directory of Open Access Journals (Sweden)

    Jayant I. Gowda

    2015-12-01

    Full Text Available The oxidation of aspartame (ASP by diperiodatocuprate(III (DPC in aqueous alkaline medium at 298 K and a constant ionic strength of 0.30 mol dm−3 was studied spectrophotometrically. The reaction between aspartame and diperiodatocuprate(III in alkaline medium exhibits 1:6 stoichiometry in the reaction. The order of the reaction with respect to [diperiodatocuprate(III] was unity, while the apparent order with respect to [aspartame] was less than unity over the concentration range studied. The rate of the reaction increased with increase in [OH−] whereas the rate decreased with increase in [$ {\\text{IO}}^-_4 $]. Increasing the ionic strength of the medium increased the rate. The main products were identified by FT-IR, NMR, and LC-MS spectral studies. The probable mechanism was proposed. The activation parameters with respect to slow step of the mechanism were computed and discussed. Thermodynamic quantities were also calculated. Kinetic studies suggest that [Cu(H2IO6(H2O2] is the reactive species of Cu(III.

  6. Leaching of the antimony and accompanying of elements Sb2S3 in the alkaline medium

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    Dagmar Remeteiová

    2007-06-01

    Full Text Available This paper presents results of the laboratory investigation of alkaline leaching of stibnite that is an important mineral occuring in the antimony-bearing raw materials. The following components were present in stibnite: Sb2S3, SiO2, ZnS, FeS2. The aim of this study was to establish the effect of composition of the aqueous alkaline leaching medium (1 % NaOH, 1 % NaOH + 1 % Na2S2O3, 1 % NaOH + 1 % Na2S on the recoveries of Sb, Fe, Pb, Zn, Cu, Ni and Hg. The antimony recoveries in the leaching solutions NaOH and NaOH + Na2S2O3 solutions were lower in comparison with the leaching in NaOH + Na2S. The Fe, Pb, Zn recoveries in alkaline solutions were found to decrease in the following order: Fe, Pb, Zn. The mercury recovery in the leaching test with the solution containing 1 % NaOH+1 % Na2S was 3,7 %.

  7. Mechanistic Investigation of Oxidation of Phenylpropanolamine with N-Bromobenzenesulfonamide in Alkaline Medium: A Kinetic Approach

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    Ningegowda Prasad

    2008-01-01

    Full Text Available The kinetics of oxidation of phenylpropanolamine (PPA with sodium N-bromobenzenesulfonamide or bromamine-B (BAB has been investigated in alkaline medium at 308 K. The oxidation reaction obeys the rate law, – d[BAB]/dt = k [BAB] [PPA]x [OH-], where x is less than unity. The variation of ionic strength of the medium, addition of the reduction product, benzenesulfonamide, and chloride ion had no pronounced effect on the reaction rate. Decrease of dielectric permittivity of the medium by increasing the CH3CN content increased the rate. The reaction was studied at different temperatures and the activation parameters have been evaluated from the Arrhenius plot. The stiochiometry of the reaction was found to be 1:1, and the oxidation product of phenylpropanolamine was identified as benzaldehyde and ethylideneamine. The rate decreased in D2O medium and the normal isotope effect k' (H2O / k' (D2O is 2.18. Proton inventory studies have been made in H2O - D2O mixtures. Formation and decomposition constant of BAB-PPA complexes in the reaction scheme have been determined. The conjugate acid, C6H5SO2NHBr is assumed to be the reactive species. The proposed mechanism and the derived rate law are consistent with the observed experimental results.

  8. Manganese mediated oxidation of progesterone in alkaline medium: Mechanism study and quantitative determination

    International Nuclear Information System (INIS)

    Shamsipur, Mojtaba; Pashabadi, Afshin; Taherpour, Avat; Bahrami, Kiumars; Sharghi, Hashem

    2017-01-01

    Highlights: • This is first report on oxidation of progesterone in alkaline medium using a new manganese (III) Schiff base complex. • Utilizing QM and MM, we modelled and interpreted the observed electrochemical behavior of complex on carbon and gold materials as platform. • The long term stability of proposed sensor is improved relative to previously reported immunosensors for P4. • A detailed mechanism was developed for the oxidation of P4. • The proposed sensor was applied to quantify P4 in cow’s milk. - Abstract: We report here a non-immunosensing approach for the electrocatalytic oxidation of progesterone (P4) in alkaline medium using a salen-type manganese Schiff base complex (Mn(III)-SB) as a suitable electrocatalyst. We explored the role of carbon surface at glassy carbon electrode (GCE) and gold surface at glassy carbon/gold nanoparticles modified electrode (GCE/AuNPs) on immobilization of the Mn(III)-SB complex using cyclic voltammetry (CV) and density functional theory (DFT) calculations. The GCE/Mn(III)-SB displayed a pair of small redox peaks attributed to Mn(II) ⇄ Mn(III) with a small peak-to-peak separation (ΔE p ), while GCE/AuNP/Mn(III)-SB displayed redox peaks with larger densities, but with a wider ΔE p . A combined molecular mechanics (MM) and quantum mechanics (QM) study were carried out to investigate the variation of surface configuration and energy barrier, when the Mn(III)-SB immobilization was modeled on GCE and GCE/Au surface. Cyclic voltammetry and hydrodynamic amperometry were used for the quantitative determination of P4. A limit of detection (LOD) of 11.4 nM was obtained using amperometry. The sensor retained 91% of its original response after 3 months, which is improved compared to previously reported P4 immunosensors. For the first time, a detailed mechanism for oxidation of P4 in alkaline medium was suggested. The proposed sensor was utilized to determine progesterone in milk samples.

  9. Nickel as a catalyst for the electro-oxidation of methanol in alkaline medium

    Science.gov (United States)

    Abdel Rahim, M. A.; Abdel Hameed, R. M.; Khalil, M. W.

    The use of Ni as a catalyst for the electro-oxidation of methanol in alkaline medium was studied by cyclic voltammetry. It was found that only Ni dispersed on graphite shows a catalytic activity towards methanol oxidation but massive Ni does not. Ni was dispersed on graphite by the electro-deposition from acidic NiSO 4 solution using potentiostatic and galvanostatic techniques. The catalytic activity of the C/Ni electrodes towards methanol oxidation was found to vary with the amount of electro-deposited Ni. The dependence of the oxidation current on methanol concentration and scan rate was discussed. It was concluded from the electro-chemical measurements and SEM analysis that methanol oxidation starts as Ni-oxide is formed on the electrode surface.

  10. Electrooxidation of 2-propanol compared ethanol on Pd electrode in alkaline medium

    Energy Technology Data Exchange (ETDEWEB)

    Su, Yuzhi; Xu, Changwei; Liu, Zhaoqing [School of Chemistry and Chemical Engineering, Guangzhou University, Guangzhou 510006 (China); Liu, Jianping [Dongguan Entry-exit Inspection and Quarantine Bureau, Dongguan 511700 (China)

    2009-10-20

    Here, the oxidation activity of 2-propanol compared ethanol on Pd electrode has been studied in alkaline medium. We have used the amount of coulombs (coulometry) and apparent activation energy (E{sub a}) to measure the activity of alcohol electrooxidation. The amount of coulombs during alcohol electrooxidation for 2-propanol is much higher than that of ethanol showing that 2-propanol is more easily electrochemically oxidized than ethanol. The E{sub a} values of 2-propanol are lower than that of ethanol at the potential from -0.45 to -0.375 V which is usually used in direct alcohol fuel cells (DAFCs) indicating that 2-propanol shows better electrooxidation activity than ethanol. (author)

  11. Carbon supported Pd-Sn and Pd-Ru-Sn nanocatalysts for ethanol electro-oxidation in alkaline medium

    CSIR Research Space (South Africa)

    Modibedi, RM

    2011-04-01

    Full Text Available Carbon supported Pd-Sn and Pd-Ru-Sn nanocatalysts were prepared by the chemical reduction method, using sodium borohydride and ethylene glycol mixture as the reducing agent. The catalytic activity towards ethanol electro-oxidation in alkaline medium...

  12. Carbon-supported cubic CoSe2 catalysts for oxygen reduction reaction in alkaline medium

    International Nuclear Information System (INIS)

    Feng Yongjun; Alonso-Vante, Nicolas

    2012-01-01

    Highlights: ► Cubic CoSe 2 a non-precious metal electrocatalyst for oxygen reduction in KOH. ► The catalyst shows four-electron transfer pathway in overall reaction. ► Catalyst has higher methanol tolerance than commercial Pt/C catalyst. - Abstract: A Carbon-supported CoSe 2 nanocatalyst has been developed as an alternative non-precious metal electrocatalyst for oxygen reduction reaction (ORR) in alkaline medium. The catalyst was prepared via a surfactant-free route and its electrocatalytic activity for the ORR has been investigated in detail in 0.1 M KOH electrolyte at 25 °C using rotating disk electrode (RDE) and rotating ring-disk electrode (RRDE) techniques. The prepared catalyst showed promising catalytic activity towards ORR in a four-electron transfer pathway and higher tolerance to methanol compared to commercial Pt/C catalyst in 0.1 M KOH. To some extent, the increase of CoSe 2 loading on the electrode favors a faster reduction of H 2 O 2 intermediate to H 2 O.

  13. Electrooxidation of methanol and ethylene glycol mixture on platinum and palladium in alkaline medium

    Energy Technology Data Exchange (ETDEWEB)

    Li, Z.Y.; Liang, Y.J.; Shan, X.D.; Lin, M.L.; Xu, C.W. [School of Chemistry and Chemical Engineering, Guangzhou University, Guangzhou (China); Jiang, S.P. [Department of Chemical Engineering, Faculty of Science and Engineering, Curtin University, Perth, WA (Australia)

    2012-08-15

    The performance of mixture of methanol and ethylene glycol (EG) oxidation has been studied on both Pt and Pd electrodes in alkaline medium. The activity of EG oxidation is better than that of methanol oxidation and the stability of EG oxidation is better than that of methanol and ethanol oxidation on the Pd electrode. The onset potential for ethanol oxidation is more negative 200 mV than that of EG, however the stability of EG oxidation on the Pd electrode is better than that of ethanol oxidation. The performance of methanol oxidation improves pronouncedly by adding a small amount of EG on both Pt and Pd electrodes. The onset potential and peak potential of mixture of methanol and EG oxidation are close to or more negative than that of sole methanol and EG oxidation on the Pd electrode. The mixture of methanol and EG is more easily to be electrochemically oxidized and gives a better performance than sole methanol and EG on the Pd electrode. The results show that the mixture of methanol and EG is a promising candidate as fuel in direct alcohol fuel cells. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  14. Kinetics and Mechanistic Study of Permanganate Oxidation of Fluorenone Hydrazone in Alkaline Medium

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    Ahmed Fawzy

    2016-01-01

    Full Text Available The oxidation kinetics of fluorenone hydrazone (FH using potassium permanganate in alkaline medium were measured at a constant ionic strength of 0.1 mol dm−3 and at 25°C using UV/VIS spectrophotometer. A first-order kinetics has been monitored in the reaction of FH with respect to [permanganate]. Less-than-unit order dependence of the reaction on [FH] and [OH−] was revealed. No pronounced effect on the reaction rate by increasing ionic strength was recorded. Intervention of free radicals was observed in the reaction. The reaction mechanism describing the kinetic results was illustrated which involves formation of 1 : 1 intermediate complex between fluorenone hydrazones and the active species of permanganate. 9H-Fluorenone as the corresponding ketone was found to be the final oxidation product of fluorenone hydrazone as confirmed by GC/MS analysis and FT-IR spectroscopy. The expression rate law for the oxidation reaction was deduced. The reaction constants and mechanism have been evaluated. The activation parameters associated with the rate-limiting step of the reaction, along with the thermodynamic quantities of the equilibrium constants, have been calculated and discussed.

  15. Oxidative dissolution of ruthenium deposits onto stainless steel by permanganate ions in alkaline medium

    Energy Technology Data Exchange (ETDEWEB)

    Floquet, S.; Eysseric, C.; Maurel, D. [Commissariat a l' Energie Atomique (CEA/Valrho), Bagnols-sur-Ceze (France)

    2008-07-01

    During spent nuclear fuel reprocessing ruthenium is liable to form black ruthenium deposits on the stainless steel walls of process equipments. These deposits promote corrosion and can eventually obstruct the off-gas lines. The results of decontamination of 304L stainless steel test specimens covered with RuO(OH){sub 2} . xH{sub 2}O deposits by permanganate ions in alkaline medium are described. The ruthenium deposits were dissolved by oxidation of RuO(OH){sub 2} to RuO{sub 4}{sup 2-} ions, while the permanganate ions were reduced to MnO{sub 4}{sup 2-} ions and then to manganese dioxide MnO{sub 2}. The parameters affecting the kinetics of oxidative dissolution of these deposits were examined. The results indicate that the oxidative dissolution kinetics depends on the instantaneous surface area of the deposit, and that the dissolution rate increases with the concentrations of MnO{sub 4}{sup -} and OH{sup -} ions. (orig.)

  16. The use of an economical medium for the production of alkaline ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-05-03

    May 3, 2010 ... marine-processing by-products for the production of alkaline proteases by Bacillus licheniformis NH1. ... meat Sardinelle powder; WSP, whole Sardinelle powder. ... are used as cleaning additives in detergents to facilitate.

  17. Iron (II) tetrakis(diaquaplatinum) octacarboxyphthalocyanine supported on multi-walled carbon nanotubes as effective electrocatalyst for oxygen reduction reaction in alkaline medium

    CSIR Research Space (South Africa)

    Mamuru, SA

    2010-11-01

    Full Text Available Oxygen reduction reaction (ORR) in alkaline medium at iron (II) tetrakis (diaquaplatinum) octacarboxyphthalocyanine (PtFeOCPc) catalyst supported on multi-walled carbon nanotubes (MWCNTs) has been described. The ORR followed the direct 4-electron...

  18. Preparation and characterization of electrocatalysts based on palladium for electro-oxidation of alcohols in alkaline medium

    International Nuclear Information System (INIS)

    Brandalise, Michele

    2012-01-01

    In this study Pd/C, Au/C, PdAu/C, PdAuPt/C, PdAuBi/C and PdAuIr/C electrocatalysts were prepared by the sodium borohydride reduction method for the electrochemical oxidation of methanol, ethanol and ethylene glycol. This methodology consists in mix an alkaline solution of sodium borohydride to a mixture containing water/isopropyl alcohol, metallic precursors and the Vulcan XC 72 carbon support. The electrocatalysts were characterized by energy dispersive X-ray (EDX), X-ray diffraction (XRD), transmission electron microscopy (TEM) and cyclic voltammetry. The electrochemical oxidation of the alcohols was studied by chronoamperometry using a thin porous coating technique. The mechanism of ethanol electro-oxidation was studied by Fourier Transformed Infrared (FTIR) in situ. The most effective electrocatalysts were tested in alkaline single cells directly fed with methanol, ethanol or ethylene glycol. Preliminary studies showed that the most suitable atomic composition for preparing the ternary catalysts is 50:45:05. Electrochemical data in alkaline medium show that the electrocatalysts PdAuPt/C (50:45:05) showed the better activity for methanol electro oxidation, while PdAuIr/C was the most active for ethanol oxidation and PdAuBi/C (50:45:05) was the most effective for ethylene glycol oxidation in alkaline medium. These results show that the addition of gold in the composition of electrocatalysts increases their catalytic activities. The spectroelectrochemical FTIR in situ data permitted to conclude that C-C bond is not broken and the acetate is formed. (author)

  19. The use of an economical medium for the production of alkaline ...

    African Journals Online (AJOL)

    The present study is concerned with the selection of new economical media based on agricultural and marine-processing by-products for the production of alkaline proteases by Bacillus licheniformis NH1. Powders from different fish species were prepared and then tested as growth media at a concentration of 10 g/l for ...

  20. Stimulatory effect of medium ingredients on alkaline protease production by bacillus licheniformis N-2 and compatibility studies with commercial detergents

    International Nuclear Information System (INIS)

    Nadeem, M.; Baig, S.; Qazi, J.I.

    2008-01-01

    Suitable concentration of ingredients of the growth medium played a vital role in production of alkaline protease by Bacillus licheniformis. Maximum enzyme activity (875.05 PU/ml) was achieved when the bacterium was grown in the medium containing glucose (1%), soybean meal (1%), K/sub 2/ HPO/sub 4/ (0.5%), MgSO/sub 4/ 7H/sub 2/O (0.05%), NaCI (0.05%), CaCI/sub 2/ 2H/sub 2/O (0.05%) at 37 degree C on 24 h incubation period with agitation of 140 rpm in shake flask cultures. More than 1% glucose decreased the enzyme production. The protease had excellent stability with wide range of Commercial detergents such as Ariel, Bonus, Bright Total, Surf Excel, Wheel and non-branded detergents, recommending its use as an effective additive in detergent formulation. (author)

  1. Cobalt hydroxide film on Pt as co-catalyst for oxidation of polyhydric alcohols in alkaline medium

    International Nuclear Information System (INIS)

    Das, Debasmita; Das, Kaushik

    2010-01-01

    Electrochemical behavior of chemically prepared Co(OH) 2 film on Pt has been studied in alkaline medium using cyclic voltammetry and chronoamperometry. Amount of Co(OH) 2 deposited increases linearly with the number of times of deposition. The deposit is of fibrous structure, as shown by scanning electron microphotograph. There is evidence of Co II /Co III and Co III /Co IV redox transitions during the cyclic potential scan. The former oxidation proceeds under diffusion control. The Co(OH) 2 deposit acts as an efficient co-catalyst for anodic oxidation of ethanediol, propanediol and glycerol on Pt in alkaline medium. This is demonstrated by appreciable enhancement of the alcohol oxidation currents upon deposition of Co(OH) 2 on Pt. Among the alcohols studied, the highest oxidation currents are obtained for ethanediol, both on Co(OH) 2 /Pt and bare Pt. Co(OH) 2 alone also acts as a redox mediator for alcohol oxidation at more positive potentials.

  2. Micelle formation during extraction of alkali elements from strongly alkaline mediums

    International Nuclear Information System (INIS)

    Apanasenko, V.V.; Reznik, A.M.; Bukin, V.I.; Brodskaya, A.V.

    1988-01-01

    Extraction of potassium, rubidium and cesium by phenol reagents in hydrocarbon solvents from strongly alkakine solutions was considered. Tendency of prepared alkali metal phenolates to form micelles in aqueous and organic phases was revealed. Phenolates tendency to form micelles is dictated mainly by the size and position of hydrocarbon substituent in molecule. It is shown that when micelles form in organic phase, alkali elements can be extracted both according to cation-exchange mechanism and according to micellar one. It is noted that alkai element extraction from strongly alkaline media requires the correct choice of extractant: alkali metal phenolate shouldn't form micelles in aqueous solution. n-Alkyl- and arylphenoldisulfides and polysulfides are most preferable for solvent extraction among considered phenol derivatives

  3. High Electrocatalytic Performance of CuCoNi@CNTs Modified Glassy Carbon Electrode towards Methanol Oxidation in Alkaline Medium

    Directory of Open Access Journals (Sweden)

    Amina A. Hamza

    2017-01-01

    Full Text Available A novel non-precious multiwalled carbon nanotubes (CNTs—supported metal oxide electrocatalyst was developed for methanol electrooxidation in alkaline medium. The catalyst was fabricated by simultaneous electrodeposition of copper-cobalt-nickel ternary nanostructures (CuCoNi on a glassy carbon electrode (GCE modified with CNTs. The proposed electrode was characterized using X-ray diffraction (XRD, energy dispersive X-ray (EDX, and scanning electron microscopy (SEM. The electrochemical behavior and the electrocatalytic performance of the suggested electrode towards the oxidation of methanol were evaluated by cyclic voltammetry (CV, linear sweep voltammetry (LSV, and chronoamperometry (CA in alkaline medium. Several parameters were investigated, e.g., deposition time, potential scan rate, etc. Compared to Cu, Co, or Ni mono electrocatalysts, the electrode based on ternary-metals exhibited superior electrocatalytic activity and stability towards methanol electrooxidation. For instance, CuCoNi@CNTs/GCE has shown at least 2.5 times electrocatalytic activity and stability compared to the mono eletrocatalysts. Moreover, the present study found that the optimized loading level is 1500 s of simultaneous electrodeposition. At this loading level, it was found that the relation between the Ip/ν1/2 function and scan rate gives the characteristic features of a catalytic process. The enhanced activity and stability of CuCoNi@CNTs/GCE was attributed to (i a synergism between three metal oxides coexisting in the same structure; (ii the presence of CNTs as a support for the metal oxides, that offers high surface area for the deposited tertiary alloy and suppresses the aggregation and sintering of the metals oxide with time; as well as (iii the increase of the conductivity of the deposited semiconducting metal oxides.

  4. Liquid-liquid extraction of plutonium and americium by cekanoic acid from alkaline medium

    International Nuclear Information System (INIS)

    Venugopal Chetty, K.; Sagar, V.; Swarup, R.

    2001-01-01

    Liquid-liquid extraction studies of plutonium and americium from aqueous carbonate medium using a high molecular weight carboxylic acid namely cekanoic acid in different diluents has been carried out. The distribution ratio (D) values for Pu(IV) and Am(III) under various parameters such as concentration of extractant, Na 2 CO 3 and initial pH were obtained. Results indicated that Pu(IV) and Am(III) could be satisfactorily extracted together or individually from aqueous carbonate medium using cekanoic acid in different diluents like carbon tetrachloride, cyclohexane, toluene, n-dodecane or solvesso-100. The D values for Pu(IV) and Am(III) also indicated the possibility of their mutual separation. The back extraction of Pu and Am with different reagents was also studied. (orig.)

  5. Synthesis and electrocatalytic activity of Au/Pt bimetallic nanodendrites for ethanol oxidation in alkaline medium.

    Science.gov (United States)

    Han, Xinyi; Wang, Dawei; Liu, Dong; Huang, Jianshe; You, Tianyan

    2012-02-01

    Gold/Platinum (Au/Pt) bimetallic nanodendrites were successfully synthesized through seeded growth method using preformed Au nanodendrites as seeds and ascorbic acid as reductant. Cyclic voltammograms (CVs) of a series of Au/Pt nanodendrites modified electrodes in 1M KOH solution containing 1M ethanol showed that the electrocatalyst with a molar ratio (Au:Pt) of 3 exhibited the highest peak current density and the lowest onset potential. The peak current density of ethanol electro-oxidation on the Au(3)Pt(1) nanodendrites modified glassy carbon electrode (Au(3)Pt(1) electrode) is about 16, 12.5, and 4.5 times higher than those on the polycrystalline Pt electrode, polycrystalline Au electrode, and Au nanodendrites modified glassy carbon electrode (Au dendrites electrode), respectively. The oxidation peak potential of ethanol electro-oxidation on the Au(3)Pt(1) electrode is about 299 and 276 mV lower than those on the polycrystalline Au electrode and Au dendrites electrode, respectively. These results demonstrated that the Au/Pt bimetallic nanodendrites may find potential application in alkaline direct ethanol fuel cells (ADEFCs). Copyright © 2011 Elsevier Inc. All rights reserved.

  6. Ag supported on carbon fiber cloth as the catalyst for hydrazine oxidation in alkaline medium

    International Nuclear Information System (INIS)

    Liu, Ran; Ye, Ke; Gao, Yinyi; Zhang, Wenping; Wang, Guiling; Cao, Dianxue

    2015-01-01

    Highlights: • CFC supported microspherical Ag is obtained by square-wave potential method. • Ag/CFC electrode has high catalytic activity toward hydrazine oxidation. • Hydrazine oxidation on the electrode proceeds by a near 4-electron pathway. - Abstract: Silver particles with microspheric structure are directly electrodeposited on carbon fiber cloth (CFC) substrate by square-wave potential electrodeposition method. The electrocatalytic behaviors of the Ag/CFC electrode toward hydrazine oxidation in alkaline solution are examined by cyclic voltammetry and chronoamperometry. An onset oxidation potential of -0.5 V and a peak current density of 30 mA cm −2 are achieved in the solution containing 1.0 mol L −1 KOH and 20.0 mmol L −1 hydrazine. The microspheric structure of the Ag/CFC electrode provides large electroactive surface area, hence, abundant active sites are vacant for hydrazine oxidation. The calculated apparent activation energies at different potentials show that hydrazine electro-oxidation at higher potential has faster kinetics than that at lower potential. In addition, the transfer electron number of hydrazine oxidation reaction on the Ag/CFC electrode is close to four, suggesting hydrazine is almost completely electrooxidized on the electrode and the full use of hydrazine fuel is basically achieved.

  7. Electrochemical reduction of oxygen on lead-silver alloys in an alkaline medium

    International Nuclear Information System (INIS)

    Seliverstov, S.D.; Arkhangel'skaya, Z.P.; Lyzlov, N.Y.

    1986-01-01

    The use of lead-silver alloys as materials for the gas-absorbing electrode in sealed silver-cadmium alkaline storage batteries is desirable primarily from the stanpoint of saving the costly silver. The authors studied reduction of oxygen with the aim of optimizing the composition of the Pb-Ag alloy and of the porous structure of the electrodes. The alloys were made in a muffle furnace in corundum crucibles under a layer of VI-2 flux. Curves are shown which represent the dependence of the ionization current of molecular oxygen on smooth partially immersed electrodes made from alloys differing in composition on the length of the part of the electrode withdrawn from the solution. It is shown that decrease of the corrosion resistance of the alloy in the porous electrode causes partial loss of its mechanical strength. Worsening of the electric contact between the particles of active material is also possible. An alloy of the composition (mass %) 60 Pb-40 Ag is the most suitable from the practical standpoint

  8. Graphene–poly(5-aminoindole) composite film as Pt catalyst support for methanol electrooxidation in alkaline medium

    International Nuclear Information System (INIS)

    Yue, Ruirui; Zhang, Qiang; Wang, Caiqin; Du, Yukou; Yang, Ping; Xu, Jingkun

    2013-01-01

    Highlights: • Electropolymerization of 5-aminoindole (AIn) in the presence of graphene (GE). • Significant catalytic effect of GE on the polymerization of AIn. • PAIn/GE/GC used as Pt catalyst support. • The enhanced catalytic activity of Pt/PAIn/GE/GC for methanol electrooxidation. -- Abstract: 5-Aminoindole (AIn) was electropolymerized on graphene (GE) modified glass carbon (GC) electrode in 0.5 M H 2 SO 4 aqueous solution containing 0.01 M AIn. Because of the catalytic effect of GE, the polymerization efficiency of AIn and the electrochemical activity of as-formed poly(5-aminoindole) (PAIn) were significantly improved on GE/GC electrode as compared to that on the bare GC electrode. The prepared PAIn/GE/GC electrode was used as substrate for Pt particle electrodeposition. SEM, EDX and Raman spectral were used to characterize the prepared electrodes. Electrocatalytic experiments demonstrate that the Pt/PAIn/GE/GC electrode possesses high catalytic activity toward methanol electrooxidation in alkaline medium, due to the good dispersion of Pt particles on PAIn/GE/GC and the electronic interactions between the metal particles and the polymer matrixes. Thus, PAIn can be a promising alternative for polymeric catalyst support in direct alcohol fuel cells

  9. The effect of iridium(III) ions on the formation of iron oxides in a highly alkaline medium

    Energy Technology Data Exchange (ETDEWEB)

    Krehula, Stjepko, E-mail: krehul@irb.hr [Division of Materials Chemistry, Ruder Boskovic Institute, PO Box 180, HR-10002 Zagreb (Croatia); Music, Svetozar [Division of Materials Chemistry, Ruder Boskovic Institute, PO Box 180, HR-10002 Zagreb (Croatia)

    2012-03-05

    Highlights: Black-Right-Pointing-Pointer Study of the influence of Ir{sup 3+} ions on the precipitation of iron oxides. Black-Right-Pointing-Pointer Ir{sup 3+} doping in {alpha}-FeOOH caused significant changes in the microstructural properties. Black-Right-Pointing-Pointer Ir{sup 3+} doping in {alpha}-Fe{sub 2}O{sub 3} caused an increase in the Morin transition temperature. Black-Right-Pointing-Pointer Ir{sup 3+} ions caused a phase transformation {alpha}-(Fe,Ir)OOH {yields} {alpha}-(Fe,Ir){sub 2}O{sub 3} {yields} Fe{sub 3}O{sub 4} + Ir{sup 0}. - Abstract: The effect of the presence of Ir{sup 3+} ions on the formation of iron oxides in a highly alkaline precipitation system was investigated using X-ray powder diffraction (XRD), {sup 57}Fe Moessbauer and FT-IR spectroscopies, field emission scanning electron microscopy (FE-SEM) and energy dispersive X-ray spectroscopy (EDS). Monodispersed lath-like {alpha}-FeOOH (goethite) particles precipitated by hydrothermal treatment in a highly alkaline medium with the addition of tetramethylammonium hydroxide (TMAH) were used as reference material. The presence of Ir{sup 3+} ions in the precipitation system strongly influenced the phase composition, magnetic, structural and morphological properties of obtained samples. The formation of {alpha}-Fe{sub 2}O{sub 3} (hematite) along with {alpha}-FeOOH in the first stage of hydrothermal treatment and the transformation of {alpha}-FeOOH and {alpha}-Fe{sub 2}O{sub 3} to Fe{sub 3}O{sub 4} (magnetite) by a longer hydrothermal treatment was caused by the presence of Ir{sup 3+} ions. Ir{sup 3+} for Fe{sup 3+} substitution in the structure of {alpha}-FeOOH brought about changes in unit-cell dimensions, crystallinity, particle size and shape, hyperfine magnetic field and infrared bands positions. Ir{sup 3+} for Fe{sup 3+} substitution in the structure of {alpha}-Fe{sub 2}O{sub 3} led to an increase in the temperature of the Morin transition; Moessbauer spectroscopy showed the presence of

  10. High electrocatalytic performance of nitrogen-doped carbon nanofiber-supported nickel oxide nanocomposite for methanol oxidation in alkaline medium

    Energy Technology Data Exchange (ETDEWEB)

    Al-Enizi, Abdullah M. [Department of Chemistry, King Saud University, PO Box: 2455, Riyadh 11451 (Saudi Arabia); Elzatahry, Ahmed A., E-mail: aelzatahry@ksu.edu.sa [Materials Science and Technology Program, College of Arts and Science, Qatar University, Doha 2713 (Qatar); Advanced Technology and New Materials Research Institute, City of Scientific Research and Technology Applications, New Borg El-Arab City, Alexandria 21934 (Egypt); Abdullah, Aboubakr M., E-mail: bakr@qu.edu.qa [Center for Advanced Materials, Qatar University, Doha 2713 (Qatar); Vinu, Ajayan [Future Industries Institute, University of South Australia, Building X-X2-09, Mawson Lakes Campus, Mawson Lakes 5095 SA (Australia); Iwai, Hideo [Materials Analysis Station, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki, 305-0047 (Japan); Al-Deyab, Salem S. [Petrochemical Research Chair, Department of Chemistry, King Saud University, PO Box: 2455, Riyadh 11451 (Saudi Arabia)

    2017-04-15

    Highlights: • A mixture of Polyvinylpyrrolidone (PVP), graphene and emeraldine base polyaniline (PANi) was electrospun and used as starting materials to prepare a nitrogen-doped carbon nanofiber (N-CNF). • Nickel oxide was loaded on the N-CNF to form a nanocomposite which was calcined later at different temperatures. • The effect of calcination temperature on the electrocatalytic behavior of the nanocomposite was studied which shows that the nanocomposite calcined at 500 °C was proved to be very high compared to the other calcination temperatures. • The stability of catalyst was excellent and its resistance to the adsorption of the intermediates generated from the methanol oxidation was very high. - Abstract: Nitrogen-Doped Carbon Nanofiber (N-CNF)–supported NiO composite was prepared by electrospinning a sol-gel mixture of graphene and polyaniline (PANi) with aqueous solutions of Polyvinylpyrrolidone (PVP) followed by a high-temperature annealing process. The electrospun was stabilized for 2 h at 280 °C, carbonized for 5 h at 1200 °C then loaded by 10% NiO. The electrocatalytic activities of the produced nanocomposite have been studied using cyclic voltammetry, and chronoamperometry. Also, N-CNF was characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), surface area (BET), X-ray photoelectron spectroscopy (XPS), transmission electron microscope (TEM), and scanning-electron microscopy (SEM). The obtained N-doped carbon nanofiber was found to have a nitrogen content of 2.6 atomic% with a diameter range of (140–160) nm, and a surface area (393.3 m{sup 2} g{sup −1}). In addition, it showed a high electrocatalytic behavior towards methanol oxidation reaction in alkaline medium and high stability and resistivity to the adsorption of intermediates.

  11. Stability of rapidly quenched and hydrogenated Mg-Ni-Y and Mg-Cu-Y alloys in extreme alkaline medium

    International Nuclear Information System (INIS)

    Gebert, A.; Khorkounov, B.; Wolff, U.; Mickel, Ch.; Uhlemann, M.; Schultz, L.

    2006-01-01

    Amorphous-nanocrystalline Mg 50 Ni 30 Y 20 and Mg 63 Ni 30 Y 7 and amorphous Mg 65 Cu 25 Y 10 alloys were produced by melt-spinning and characterized regarding their microstructure and thermal behaviour using XRD, TEM and DSC. Their electrochemical behaviour in the as-quenched state and after hydrogen charging at -25 mA/cm 2 for up to 20 h was studied in electrolytes with pH 5-7 and 13, but mainly in a battery electrolyte: 6 M KOH with pH 14.8 by means of anodic and cathodic polarization measurements. In the as-quenched state, the highest alloys stability was observed at pH 13. At pH 14.8, gradual oxidation and dissolution of copper or nickel governs the anodic behaviour before a passive state is attained. The dissolution of nickel is much more inhibited than that of copper due to its lower tendency to form soluble oxidized ions and to a stabilizing effect of higher fractions of yttrium in the alloy on the passivation. By galvanostatic charging, the Mg 65 Cu 25 Y 10 alloy shows the highest hydrogen absorption capacity followed by Mg 50 Ni 30 Y 20 and Mg 63 Ni 30 Y 7 . During the charging process, the alloys exhibit a change in the surface state chemistry, i.e. an enrichment of nickel- or copper-rich species, causing preferential oxidation and dissolution during subsequent exposure under free corrosion and anodic conditions. Mg-Ni-Y alloys demonstrate a higher stability during this treatment in extreme alkaline medium. The reasons for this and consequences regarding the use as electrode materials are discussed in detail

  12. The impact of electrochemical reduction potentials on the electrocatalytic activity of graphene oxide toward the oxygen reduction reaction in an alkaline medium

    International Nuclear Information System (INIS)

    Toh, Shaw Yong; Loh, Kee Shyuan; Kamarudin, Siti Kartom; Daud, Wan Ramli Wan

    2016-01-01

    We report the synthesis of graphene via the electrochemical reduction of graphene oxide (GO). In this study, GO nanosheets from aqueous dispersion were pre-assembled on a glassy carbon (GC) electrode and then electrochemically reduced in 1 M KOH under various constant reduction potentials in the range of −0.6 V to −1.5 V (vs. Ag/AgCl). X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy analyses revealed that the graphitic structure was substantially restored in the resulting electrochemically reduced graphene oxide (ERGO). The ERGO electrodes exhibited significantly enhanced catalytic activity toward the oxygen reduction reaction (ORR) in an alkaline medium compared with the initial GO electrode. Of the ERGO electrodes produced at various cathodic potentials, the ERGO-1.2 V electrode, which was produced at a reduction potential of −1.2 V, demonstrated the best catalytic activity toward the ORR in an alkaline medium. The ORR on GO and ERGO electrodes was shown to proceed via a two-electron mechanism at low overpotentials. The agreement between the spectroscopy results and electrochemical measurements provide strong evidence that the enhanced ORR catalytic activity is mainly attributed to the restoration of GO’s graphitic structure. Furthermore, the ERGO-1.2 V electrode showed excellent tolerance to the methanol poisoning effect compared with a Pt/C catalyst electrode.

  13. Substrate inhibition: Oxidation of D-sorbitol and D-mannitol by potassium periodate in alkaline medium

    Science.gov (United States)

    Lakshman Kumar, Y.; Venkata Nadh, R.; Radhakrishnamurti, P. S.

    2014-05-01

    In the oxidation of D-sorbitol and D-mannitol by potassium periodate in alkaline media, substrate inhibition was observed with both substrates, i.e., a decrease in the rate of the reaction was observed with an increase in the concentration of substrate. The substrate inhibition was attributed to the formation of stable complex between the substrate and periodate. The reactions were found to be first order in case of periodate and a positive fractional order with hydroxide ions. Arrhenius parameters were calculated for the oxidation of sorbitol and mannitol by potassium periodate in alkali media.

  14. Wear and chemistry of zirconium-silicate, aluminium-silicate and zirconium-aluminium-silicate glasses in alkaline medium

    International Nuclear Information System (INIS)

    Rouse, C.G.; Lemos Guenaga, C.M. de

    1984-01-01

    A study of the chemical durability, in alkaline solutions, of zirconium silicate, aluminium silicate, zirconium/aluminium silicate glasses as a function of glass composition is carried out. The glasses were tested using standard DIN-52322 method, where the glass samples are prepared in small polished pieces and attacked for 3 hours in a 800 ml solution of 1N (NaOH + NA 2 CO 3 ) at 97 0 C. The results show that the presence of ZrO 2 in the glass composition increases its chemical durability to alkaline attack. Glasses of the aluminium/zirconium silicate series were melted with and without TiO 2 . It was shown experimentally that for this series of glasses, the presence of both TiO 2 and ZrO 2 gave better chemical durability results. However, the best overall results were obtained from the simpler zirconium silicate glasses, where it was possible to make glasses with higher values of ZrO 2 . (Author) [pt

  15. Kinetics and Mechanism of Oxidation of Triethylene Glycol and Tetraethylene Glycol by Ditelluratoargentate (III in Alkaline Medium

    Directory of Open Access Journals (Sweden)

    Jinhuan Shan

    2013-01-01

    Full Text Available The kinetics of oxidation of triethylene glycol and tetraethylene glycol by ditelluratoargentate (III (DTA in alkaline liquids has been studied spectrophotometrically in the temperature range of 293.2 K–313.2 K. The reaction rate showed first-order dependence in DTA and fractional order with respect to triethylene glycol or tetraethylene glycol. It was found that the pseudo-first-order rate constant (kobs increased with an increase in concentration of OH− and a decrease in concentration of H4TeO6 2−. There was a negative salt effect and no free radicals were detected. A plausible mechanism involving a two-electron transfer was proposed, and the rate equations derived from the mechanism explained all the experimental results and observations. The activation parameters along with the rate constants of the rate-determining step were calculated.

  16. Copper-zinc electrodeposition in alkaline-sorbitol medium: Electrochemical studies and structural, morphological and chemical composition characterization

    Science.gov (United States)

    de Almeida, M. R. H.; Barbano, E. P.; de Carvalho, M. F.; Tulio, P. C.; Carlos, I. A.

    2015-04-01

    The galvanostatic technique was used to analyze the electrodeposition of Cu-Zn on to AISI 1010 steel electrode from an alkaline-sorbitol bath with various proportions of the metal ions in the bath: Cu70/Zn30, Cu50/Zn50 and Cu30/Zn70. Coloration of Cu-Zn films were whitish golden, light golden, golden/gray depending on the Cu2+/Zn2+ ratios in the electrodeposition bath, deposition current density (jdep) and charge density (qdep). The highest current efficiency was ∼54.0%, at jdep -1.0 mA cm-2 and qdep 0.40 C cm-2 in the Cu70/Zn30 bath. Energy dispersive spectroscopy indicated that electrodeposits produced from the bath Cu70/Zn30 showed higher Cu content at lower jdep. Also, for same jdep the Cu content increased with qdep. Scanning electron microscopy showed that Cu-Zn electrodeposits of high quality were obtained from the Cu70/Zn30 bath, since the films were fine-grained, except the obtained at jdep -20.0 mA cm-2 and qdep 10.0 C cm-2. Also, these electrodeposits did not present cracks. X-ray analysis of the Cu-Zn electrodeposits obtained at jdep -8.0, -20.0 and -40.0 mA cm-2, in each case, with qdep 2.0 and 10.0 C cm-2, in the Cu70/Zn30 bath, suggested the occurrence of a mixture of the following phases, CuZn, CuZn5 and Cu5Zn8. Galvanostatic electrodeposits of Cu-Zn obtained from sorbitol-alkaline baths exhibited whitish golden color, with good prospects for industrial applications, especially for decorative purposes.

  17. Role of Ru(IlI) as an inhibitor in oxidation of lactose by (Cu(bipy)2)2+ in alkaline medium: spectrophotometric and kinetic studies

    International Nuclear Information System (INIS)

    Singh, Ashok Kumar; Singh, Manjula; Srivastava, Jaya; Rahmani, Shahla

    2013-01-01

    Kinetics of oxidation of lactose by (Cu(bipy) 2 ) 2+ in alkaline medium using Ru(III) as an inhibitor has been studied spectrophotometrically at 40 °C. The studies show that the rate of the reaction is zero order with respect to (Cu(bipy) 2 ) 2+ and first order with respect to (lactose). The order of reaction is found to be two at low concentrations of OH - (from 1.48×10 5 to 3.47×10 5 M) and less than two at its high concentrations (from 4.27×10 5 to 6.31×10 5 M). There is a substantial decrease in the pseudo-zero order rate constant with increase in the concentration of Ru(III) chloride, indicating the role of Ru(III) chloride as an inhibitor. Decrease in the rate with increase in dielectric constant of the medium is observed, while ionic strength of the medium and bipyridyl concentration has no influence on the rate. Based on kinetic data and spectrophotometric evidences, a suitable mechanism is proposed for the studied reaction. (author)

  18. Ethanol electro-oxidation in alkaline medium using Pd/MWCNT and PdAuSn/MWCNT electrocatalysts prepared by electron beam irradiation

    International Nuclear Information System (INIS)

    Geraldes, Adriana Napoleao; Silva, Dionisio Furtunato da; Andrade e Silva, Leonardo Gondin de; Spinace, Estevam Vitorio; Oliveira Neto, Almir; Santos, Mauro Coelho dos

    2015-01-01

    Environmental problems and the world growing demand for energy has mobilized the scientific community in finding of clean and renewable energy sources. In this context, fuel cells appear as appropriate technology for generating electricity through alcohols electro-oxidation. Multi Wall Carbon Nanotubes (MWCNT)-supported Pd and trimetallic PdAuSn (Pd:Au:Sn 50:10:40 atomic ratio) electrocatalysts were prepared using electron beam irradiation. The obtained materials were characterized by VC, Chronoamperometry, EDX, TEM and XRD. The catalytic activities of electrocatalysts toward ethanol electro-oxidation were evaluated in alkaline medium in a single alkaline direct ethanol fuel cell (ADEFC) in a range temperature 60 to 90 deg C. The best performances were obtained at 85 deg C: 33 mW.cm -2 and 31 mW.cm -2 for Pd/ MWCNT and PdAuSn/MWCNT electrocatalysts, respectively. X-ray diffractograms of electrocatalysts showed the presence of Pd-rich (fcc) and Au-rich (fcc) phases. Cyclic voltammetry and chronoamperometry experiments showed that PdAuSn/MWCNT electrocatalyst demonstrated similar activity toward ethanol electro-oxidation at room temperature, compared to electrocatalyst Pd/MWCNT. (author)

  19. Ethanol electro-oxidation in alkaline medium using Pd/c and PdRh/C electrocatalysts prepared by electron beam irradiation

    International Nuclear Information System (INIS)

    Silva, Dionisio Furtunato da; Geraldes, Adriana Napoleao; Pino, Eddy Segura; Spinace, Estevam Vitorio; Oliveira Neto, Almir; Linardi, Marcelo

    2013-01-01

    In this study, carbon-supported Pd (Pd/C) and bimetallic PdRh (Pd:Rh 90:10 atomic ratio) (PdRh/C) electrocatalysts were prepared using electron beam irradiation. The morphology and composition of the obtained materials were characterized by Cyclic voltammetry (VC), Chronoamperometry (CA), Energy dispersive X-ray (EDX), X-ray Diffraction (XRD) and Thermo-gravimetric analysis (TGA). The catalytic activities of the electrocatalysts toward the ethanol electro-oxidation were evaluated in alkaline medium in a single alkaline direct ethanol fuel cell (ADEFC), in a range temperature of 50 to 85 deg C. The best performances were obtained at 85 deg C (25 mW.cm -2 ) and 75 deg C (38 mW.cm -2 ) for Pd/C and PdRh/C electrocatalysts, respectively. The XRD of the PdRh/C electrocatalyst showed the presence of Pd-rich (fcc) phase. CV and CA experiments showed that PdRh/C electrocatalyst demonstrated superior activity toward ethanol electro-oxidation at room temperature, compared to Pd/C electrocatalyst. (author)

  20. Direct, simple derivatization of disulfide bonds in proteins with organic mercury in alkaline medium without any chemical pre-reducing agents

    Energy Technology Data Exchange (ETDEWEB)

    Campanella, Beatrice; Onor, Massimo [National Research Council of Italy, C.N.R., Istituto di Chimica dei Composti Organo Metallici-ICCOM- UOS Pisa, Area di Ricerca, Via G. Moruzzi 1, 56124 Pisa (Italy); Ferrari, Carlo [National Research Council of Italy, C.N.R., Istituto Nazionale di Ottica, INO-UOS Pisa, Area di Ricerca, Via G. Moruzzi 1, 56124 Pisa (Italy); D’Ulivo, Alessandro [National Research Council of Italy, C.N.R., Istituto di Chimica dei Composti Organo Metallici-ICCOM- UOS Pisa, Area di Ricerca, Via G. Moruzzi 1, 56124 Pisa (Italy); Bramanti, Emilia, E-mail: bramanti@pi.iccom.cnr.it [National Research Council of Italy, C.N.R., Istituto di Chimica dei Composti Organo Metallici-ICCOM- UOS Pisa, Area di Ricerca, Via G. Moruzzi 1, 56124 Pisa (Italy)

    2014-09-16

    Highlights: • A simple procedure for the derivatization of proteins disulfide bonds. • Cysteine groups in several proteins derivatised with pHMB in alkaline media. • 75–100% labelling of cysteines in proteins with pHMB. - Abstract: In this work we have studied the derivatization of protein disulfide bonds with p-Hydroxymercurybenzoate (pHMB) in strong alkaline medium without any preliminary reduction. The reaction has been followed by the determination of the protein–pHMB complex using size exclusion chromatography coupled to a microwave/UV mercury oxidation system for the on-line oxidation of free and protein-complexed pHMB and atomic fluorescence spectrometry (SEC–CVG–AFS) detection. The reaction has been optimized by an experimental design using lysozyme as a model protein and applied to several thiolic proteins. The proposed method reports, for the first time, that it is possible to label 75–100% cysteines of proteins and, thus, to determine thiolic proteins without the need of any reducing step to obtain reduced -SH groups before mercury labelling. We obtained a detection limit of 100 nmol L{sup −1} based on a signal-to-noise ratio of 3 for unbound and complexed pHMB, corresponding to a detection limit of proteins ranged between 3 and 360 nmol L{sup −1}, depending on the number of cysteines in the protein sequence.

  1. Ethanol electro-oxidation in alkaline medium using Pd/c and PdRh/C electrocatalysts prepared by electron beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Dionisio Furtunato da; Geraldes, Adriana Napoleao; Pino, Eddy Segura; Spinace, Estevam Vitorio; Oliveira Neto, Almir; Linardi, Marcelo, E-mail: dfsilva@ipen.br, E-mail: drinager@ig.com.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    In this study, carbon-supported Pd (Pd/C) and bimetallic PdRh (Pd:Rh 90:10 atomic ratio) (PdRh/C) electrocatalysts were prepared using electron beam irradiation. The morphology and composition of the obtained materials were characterized by Cyclic voltammetry (VC), Chronoamperometry (CA), Energy dispersive X-ray (EDX), X-ray Diffraction (XRD) and Thermo-gravimetric analysis (TGA). The catalytic activities of the electrocatalysts toward the ethanol electro-oxidation were evaluated in alkaline medium in a single alkaline direct ethanol fuel cell (ADEFC), in a range temperature of 50 to 85 deg C. The best performances were obtained at 85 deg C (25 mW.cm{sup -2}) and 75 deg C (38 mW.cm{sup -2}) for Pd/C and PdRh/C electrocatalysts, respectively. The XRD of the PdRh/C electrocatalyst showed the presence of Pd-rich (fcc) phase. CV and CA experiments showed that PdRh/C electrocatalyst demonstrated superior activity toward ethanol electro-oxidation at room temperature, compared to Pd/C electrocatalyst. (author)

  2. Ethanol electro-oxidation in alkaline medium using Pd/MWCNT and PdAuSn/MWCNT electrocatalysts prepared by electron beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Geraldes, Adriana Napoleao; Silva, Dionisio Furtunato da; Andrade e Silva, Leonardo Gondin de; Spinace, Estevam Vitorio; Oliveira Neto, Almir, E-mail: drinager@ig.com.br, E-mail: dfsilva@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Santos, Mauro Coelho dos [Universidade Federal do ABC (LEMN/CCNH/UFABC), Santo Andre, SP (Brazil)

    2015-07-01

    Environmental problems and the world growing demand for energy has mobilized the scientific community in finding of clean and renewable energy sources. In this context, fuel cells appear as appropriate technology for generating electricity through alcohols electro-oxidation. Multi Wall Carbon Nanotubes (MWCNT)-supported Pd and trimetallic PdAuSn (Pd:Au:Sn 50:10:40 atomic ratio) electrocatalysts were prepared using electron beam irradiation. The obtained materials were characterized by VC, Chronoamperometry, EDX, TEM and XRD. The catalytic activities of electrocatalysts toward ethanol electro-oxidation were evaluated in alkaline medium in a single alkaline direct ethanol fuel cell (ADEFC) in a range temperature 60 to 90 deg C. The best performances were obtained at 85 deg C: 33 mW.cm{sup -2} and 31 mW.cm{sup -2} for Pd/ MWCNT and PdAuSn/MWCNT electrocatalysts, respectively. X-ray diffractograms of electrocatalysts showed the presence of Pd-rich (fcc) and Au-rich (fcc) phases. Cyclic voltammetry and chronoamperometry experiments showed that PdAuSn/MWCNT electrocatalyst demonstrated similar activity toward ethanol electro-oxidation at room temperature, compared to electrocatalyst Pd/MWCNT. (author)

  3. Direct, simple derivatization of disulfide bonds in proteins with organic mercury in alkaline medium without any chemical pre-reducing agents

    International Nuclear Information System (INIS)

    Campanella, Beatrice; Onor, Massimo; Ferrari, Carlo; D’Ulivo, Alessandro; Bramanti, Emilia

    2014-01-01

    Highlights: • A simple procedure for the derivatization of proteins disulfide bonds. • Cysteine groups in several proteins derivatised with pHMB in alkaline media. • 75–100% labelling of cysteines in proteins with pHMB. - Abstract: In this work we have studied the derivatization of protein disulfide bonds with p-Hydroxymercurybenzoate (pHMB) in strong alkaline medium without any preliminary reduction. The reaction has been followed by the determination of the protein–pHMB complex using size exclusion chromatography coupled to a microwave/UV mercury oxidation system for the on-line oxidation of free and protein-complexed pHMB and atomic fluorescence spectrometry (SEC–CVG–AFS) detection. The reaction has been optimized by an experimental design using lysozyme as a model protein and applied to several thiolic proteins. The proposed method reports, for the first time, that it is possible to label 75–100% cysteines of proteins and, thus, to determine thiolic proteins without the need of any reducing step to obtain reduced -SH groups before mercury labelling. We obtained a detection limit of 100 nmol L −1 based on a signal-to-noise ratio of 3 for unbound and complexed pHMB, corresponding to a detection limit of proteins ranged between 3 and 360 nmol L −1 , depending on the number of cysteines in the protein sequence

  4. TiO2 obtained by laser ablation and it response in alkaline medium for the oxygen detachment reaction

    International Nuclear Information System (INIS)

    Jimenez B, J.; Escobar A, L.; Fernandez V, S.M.

    2007-01-01

    The performance of the photo electrocatalysts materials depends on one hand of the it structures of the crystalline lattice and of their surface properties, those which in turn are determined by the material preparation method. In this work the laser ablation technique to obtain thin films of titanium dioxide on recovered glass with tin oxide is presented. The carried out analyses showed homogeneous films, one of amorphous titanium oxide with a band width of 3.43 eV and the other one with anatase structure with a band energy of 3.41 eV. The photoresponse for the oxygen detachment it was better for the anatase. In a 0.1M KOH medium it was found corrosion in the films. (Author)

  5. Ethanol electro-oxidation in an alkaline medium using Pd/C, Au/C and PdAu/C electrocatalysts prepared by electron beam irradiation

    International Nuclear Information System (INIS)

    Geraldes, Adriana Napoleão; Furtunato da Silva, Dionisio; Pino, Eddy Segura; Martins da Silva, Júlio César; Brambilla de Souza, Rodrigo Fernando; Hammer, Peter; Spinacé, Estevam Vitório; Neto, Almir Oliveira; Linardi, Marcelo; Coelho dos Santos, Mauro

    2013-01-01

    Carbon-supported Pd, Au and bimetallic PdAu (Pd:Au 90:10, 50:50 and 30:70 atomic ratios) electrocatalysts were prepared using electron beam irradiation. The obtained materials were characterized by energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD) and transmission electron microscopy (TEM), and their catalytic activities toward ethanol electro-oxidation were evaluated in an alkaline medium using electrochemical techniques, in situ attenuated total reflectance Fourier transformed infrared spectroscopy (ATR-FTIR) analysis and a single alkaline direct ethanol fuel cell (ADEFC). EDX analyses showed that the actual Pd:Au atomic ratios were very similar to the nominal ones. X-ray diffractograms of PdAu/C electrocatalysts evidenced the presence of Pd-rich (fcc) and Au-rich (fcc) phases. TEM analysis showed a homogeneous dispersion of nanoparticles on the carbon support, with an average size in the range of 3–5 nm and broad size distributions. Cyclic voltammetry (CV) and chronoamperometry (CA) experiments revealed the superior ambient activity toward ethanol electro-oxidation of PdAu/C electrocatalysts with Pd:Au ratios of 90:10 and 50:50. In situ ATR-FTIR spectroscopy measurements have shown that the mechanism for ethanol electro-oxidation is dependent on catalyst composition, leading to different reaction products, such as acetaldehyde and acetate, depending on the number of electrons transferred. Experiments on a single ADEFC were conducted between 50 and 90 °C, and the best performance of 44 mW cm −2 in 2.0 mol L −1 ethanol was obtained at 85 °C for the Pd:Au 90:10 catalysts. This superior performance is most likely associated with enhancement of ethanol adsorption on Pd, oxidation of the intermediates, the presence of gold oxide-hydroxyl species, low mean particle diameters and better distribution of particles on the support

  6. Methodology of analysis of very weak acids by isotachophoresis with electrospray-ionization mass-spectrometric detection: Anionic electrolyte systems for the medium-alkaline pH range

    Czech Academy of Sciences Publication Activity Database

    Malá, Zdeňka; Gebauer, Petr

    2017-01-01

    Roč. 998, JAN (2017), s. 67-74 ISSN 0003-2670 R&D Projects: GA ČR(CZ) GA16-09135S Institutional support: RVO:68081715 Keywords : capillary isotachophoresis * ESI-MS detection * medium-alkaline pH Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 4.950, year: 2016

  7. Statistical medium optimization of an alkaline protease from Pseudomonas aeruginosa MTCC 10501, its characterization and application in leather processing.

    Science.gov (United States)

    Boopathy, Naidu Ramachandra; Indhuja, Devadas; Srinivasan, Krishnan; Uthirappan, Mani; Gupta, Rishikesh; Ramudu, Kamini Numbi; Chellan, Rose

    2013-04-01

    Proteases are shown to have greener mode of application in leather processing for dehairing of goat skins and cow hides. Production of protease by submerged fermentation with potent activity is reported using a new isolate P. aeruginosa MTCC 10501. The production parameters were optimized by statistical methods such as Plackett-Burman and response surface methodology. The optimized production medium contained (g/L); tryptone, 2.5; yeast extract, 3.0; skim milk 30.0; dextrose 1.0; inoculum concentration 4%: initial pH 6.0; incubation temperature 30 degrees C and optimum production at 48 h with protease activity of 7.6 U/mL. The protease had the following characteristics: pH optima, 9.0; temperature optima 50 degrees C; pH stability between 5.0-10.0 and temperature stability between 10-40 degrees C. The protease was observed to have high potential for dehairing of goat skins in the pre- tanning process comparable to that of the chemical process as evidenced by histology. The method offers cleaner processing using enzyme only instead of toxic chemicals in the pre-tanning process of leather manufacture.

  8. Influence of culture medium supplementation of tobacco NT1 cell suspension cultures on the N-glycosylation of human secreted alkaline phosphatase.

    Science.gov (United States)

    Becerra-Arteaga, Alejandro; Shuler, Michael L

    2007-08-15

    We report for the first time that culture conditions, specifically culture medium supplementation with nucleotide-sugar precursors, can alter significantly the N-linked glycosylation of a recombinant protein in plant cell culture. Human secreted alkaline phosphatase produced in tobacco NT1 cell suspension cultures was used as a model system. Plant cell cultures were supplemented with ammonia (30 mM), galactose (1 mM) and glucosamine (10 mM) to improve the extent of N-linked glycosylation. The highest levels of cell density and active extracellular SEAP in supplemented cultures were on average 260 g/L and 0.21 U/mL, respectively, compared to 340 g/L and 0.4 U/mL in unsupplemented cultures. The glycosylation profile of SEAP produced in supplemented cultures was determined via electrospray ionization mass spectrometry with precursor ion scanning and compared to that of SEAP produced in unsupplemented cultures. In supplemented and unsupplemented cultures, two biantennary complex-type structures terminated with one or two N-acetylglucosamines and one paucimannosidic glycan structure comprised about 85% of the SEAP glycan pool. These three structures contained plant-specific xylose and fucose residues and their relative abundances were affected by each supplement. High mannose structures (6-9 mannose residues) accounted for the remaining 15% glycans in all cases. The highest proportion (approximately 66%) of a single complex-type biantennary glycan structure terminated in both antennae by N- acetylglucosamine was obtained with glucosamine supplementation versus only 6% in unsupplemented medium. This structure is amenable for in vitro modification to yield a more human-like glycan and could serve as a route to plant cell culture produced therapeutic glycoproteins. (c) 2007 Wiley Periodicals, Inc.

  9. Poly (p-phenylendiamine/TiO2) nanocomposite promoted Pt/C catalyst for methanol and ethanol electrooxidation in alkaline medium

    International Nuclear Information System (INIS)

    Rostami, Hussein; Rostami, Abbas Ali; Omrani, Abdollah

    2016-01-01

    In the present study, poly (p-phenylendiamine/titanium dioxide) (PpPDA/TiO 2 ) nanocomposites (NCs) were prepared by in situ polymerization of p-phenylenediamine monomer with of different TiO 2 loading. A facile method was developed to promote the electrocatalytic activity of commercial Pt/C catalyst by ultrasonically mixing Pt/C catalyst and PpPDA/TiO 2 NCs. The PpPDA/TiO 2 NC, Pt/C catalyst and composite catalyst of Pt/C + PpPDA/TiO 2 were characterized by scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. The surface morphology of Pt/C is significantly influenced by the presence of PpPDA/TiO 2 NC as confirmed by SEM observations. Cyclic voltammetry (CV) measurements showed that the PpPDA/TiO 2 NC leads to a significant improvement in the activity and stability of Pt/C for alcohol oxidation especially for ethanol oxidation in alkaline medium. For Pt/C + PpPDA/TiO 2 , the onset potentials shift to negative values by 30 and 160 mV compared to the onset potentials of Pt/C for methanol and ethanol oxidation, respectively. Chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS) results also confirmed that this composite catalyst has superior catalytic performance towards ethanol oxidation compared to the pure Pt/C catalyst.

  10. Preparation of Pt Au/C and Pt Au Bi/C electrocatalysts using electron beam irradiation for ethanol electro-oxidation in alkaline medium

    International Nuclear Information System (INIS)

    Silva, Dionisio F.; Geraldes, Adriana N.; Cardoso, Elisangela S.Z.; Gomes, Thiago B.; Linardi, Marcelo; Oliveira Neto, Almir; Spinace, Estevam V.

    2011-01-01

    Pt Au/C (50:50) and PtAuBi/C electrocatalysts with Pt:Au:Bi atomic ratios of 50:40:10, 50:30:20 and 50:10:40 were prepared in water/2-propanol using electron beam irradiation. The materials were characterized by X-ray diffraction (XRD) and the electro-oxidation of ethanol was studied by chronoamperometry at room temperature. The X-ray diffraction measurements for all electrocatalysts prepared showed four peaks, which are associated with the planes of the face-centered cubic (fcc) structure characteristic of Pt and Pt alloys. For PtAuBi/C it was also observed the presence of a mixture of BiPt alloys and bismuth phases. The average crystallite sizes for Pt/C, PtAu/C, PtAuBi/C (50:40:10), PtAuBi/C (50:30:20) and PtAuBi/C (50:10:40) were in the range of 2.0 - 4.0 nm. The activity of the electrocatalysts for ethanol oxidation in alkaline medium showed that PtAuBi/C (50:40:10) had a higher performance for ethanol oxidation compared to others electrocatalysts prepared. (author)

  11. High content of pyridinic- and pyrrolic-nitrogen-modified carbon nanotubes derived from blood biomass for the electrocatalysis of oxygen reduction reaction in alkaline medium

    International Nuclear Information System (INIS)

    Zheng, Jie; Guo, Chaozhong; Chen, Chunyan; Fan, Mingzhi; Gong, Jianping; Zhang, Yanfang; Zhao, Tianxin; Sun, Yuelin; Xu, Xiaofan; Li, Mengmeng; Wang, Ran; Luo, Zhongli; Chen, Changguo

    2015-01-01

    Graphical abstract: Display Omitted -- Highlights: •An ORR electrocatalyst was fabricated from blood biomass and carbon nanotube. •The N-CNT catalyst exhibits good ORR activity, methanol resistance and stability. •The pyrolysis process produces high contents of pyridinic and pyrrolic N species. •The pyridinic-N group may play more important role in the active sites for ORR. -- Abstract: Here we present a facile synthetic route to design nitrogen-doped nanostructured carbon-based electrocatalyst for oxygen reduction reaction (ORR) by the copyrolysis of blood biomass from pig and carbon nanotubes (CNTs) at high temperatures. The nitrogen-doped CNTs obtained at 800 °C not only results in excellent ORR activity with four-electron transfer selectivity in alkaline medium, but also exhibits superior methanol-tolerant property and long-term stability. It is confirmed that high-temperature pyrolysis processes can facilitate to produce higher contents of pyridinic- and pyrrolic-N binding groups in electrocatalysts, contributing to the enhancement of ORR performance in terms of onset potential, half-wave potential, and limited current density. We also propose that the planar-N configuration may be the active site that is responsible for the improved ORR electrocatalytic performance. The straight-forward and cheap synthesis of the active and stable electrocatalyst makes it a promising candidate for electrochemical power sources such as fuel cells or metal-air batteries

  12. Rapid, general synthesis of PdPt bimetallic alloy nanosponges and their enhanced catalytic performance for ethanol/methanol electrooxidation in an alkaline medium.

    Science.gov (United States)

    Zhu, Chengzhou; Guo, Shaojun; Dong, Shaojun

    2013-01-14

    We have demonstrated a rapid and general strategy to synthesize novel three-dimensional PdPt bimetallic alloy nanosponges in the absence of a capping agent. Significantly, the as-prepared PdPt bimetallic alloy nanosponges exhibited greatly enhanced activity and stability towards ethanol/methanol electrooxidation in an alkaline medium, which demonstrates the potential of applying these PdPt bimetallic alloy nanosponges as effective electrocatalysts for direct alcohol fuel cells. In addition, this simple method has also been applied for the synthesis of AuPt, AuPd bimetallic, and AuPtPd trimetallic alloy nanosponges. The as-synthesized three-dimensional bimetallic/trimetallic alloy nanosponges, because of their convenient preparation, well-defined sponge-like network, large-scale production, and high electrocatalytic performance for ethanol/methanol electrooxidation, may find promising potential applications in various fields, such as formic acid oxidation or oxygen reduction reactions, electrochemical sensors, and hydrogen-gas sensors. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Preparation of Pt Au/C and Pt Au Bi/C electrocatalysts using electron beam irradiation for ethanol electro-oxidation in alkaline medium

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Dionisio F.; Geraldes, Adriana N.; Cardoso, Elisangela S.Z.; Gomes, Thiago B.; Linardi, Marcelo; Oliveira Neto, Almir; Spinace, Estevam V., E-mail: dfsilva@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    Pt Au/C (50:50) and PtAuBi/C electrocatalysts with Pt:Au:Bi atomic ratios of 50:40:10, 50:30:20 and 50:10:40 were prepared in water/2-propanol using electron beam irradiation. The materials were characterized by X-ray diffraction (XRD) and the electro-oxidation of ethanol was studied by chronoamperometry at room temperature. The X-ray diffraction measurements for all electrocatalysts prepared showed four peaks, which are associated with the planes of the face-centered cubic (fcc) structure characteristic of Pt and Pt alloys. For PtAuBi/C it was also observed the presence of a mixture of BiPt alloys and bismuth phases. The average crystallite sizes for Pt/C, PtAu/C, PtAuBi/C (50:40:10), PtAuBi/C (50:30:20) and PtAuBi/C (50:10:40) were in the range of 2.0 - 4.0 nm. The activity of the electrocatalysts for ethanol oxidation in alkaline medium showed that PtAuBi/C (50:40:10) had a higher performance for ethanol oxidation compared to others electrocatalysts prepared. (author)

  14. Controlled synthesis of La1−xSrxCrO3 nanoparticles by hydrothermal method with nonionic surfactant and their ORR activity in alkaline medium

    International Nuclear Information System (INIS)

    Choi, Bo Hyun; Park, Shin-Ae; Park, Bong Kyu; Chun, Ho Hwan; Kim, Yong-Tae

    2013-01-01

    Graphical abstract: We demonstrate that Sr-doped LaCrO 3 nanoparticles were successfully prepared by the hydrothermal synthesis method using the nonionic surfactant Triton X-100 and the applicability of La 1−x Sr x CrO 3 to oxygen reduction reaction (ORR) electrocatalysis in an alkaline medium. Compared with the nanoparticles synthesized by the coprecipitation method, they showed enhanced ORR activity. - Highlights: • Sr-doped LaCrO 3 nanoparticles were successfully prepared by the hydrothermal method using the nonionic surfactant. • Homogeneously shaped and sized Sr-doped LaCrO 3 nanoparticles were readily obtained. • Compared with the nanoparticles synthesized by the coprecipitation method, they showed an enhanced ORR activity. • The main origin was revealed to be the decreased particle size due to the nonionic surfactant. - Abstract: Sr-doped LaCrO 3 nanoparticles were prepared by the hydrothermal method with the nonionic surfactant Triton X-100 followed by heat treatment at 1000 °C for 10 h. The obtained perovskite nanoparticles had smaller particle size (about 100 nm) and more uniform size distribution than those synthesized by the conventional coprecipitation method. On the other hand, it was identified with the material simulation that the electronic structure change by Sr doping was negligible, because the initially unfilled e g -band was not affected by the p-type doping. Finally, the perovskite nanoparticles synthesized by hydrothermal method showed much higher ORR activity by over 200% at 0.8 V vs. RHE than those by coprecipitation method

  15. Morphology-dependent electrocatalytic performance of Fe2(MoO43 for electro-oxidation of methanol in alkaline medium

    Directory of Open Access Journals (Sweden)

    Daoming Zhang

    2017-06-01

    Full Text Available Electrochemically synthesized nanosphere, nanorod and nanotube Fe2(MoO43 at optimized temperature and current density are characterized with XRD, SEM, TEM, XPS. Crystal lattices of the three types Fe2(MoO43 detected by HRTEM are well matched with the simulation analysis results from Materials Studio 6.0 based on the inorganic crystal structure database (ICSD data and the modified XRD lattice parameters. The ratios of Fe/Mo on the surface resulted from XPS analysis are 1.47, 1.63 and 2.22 respectively for nanosphere, nanorod and nanotube. The mixture of Fe2(MoO43 with polytetrafluoroethylene dispersion are coated on glass carbon substrate as electrode for electrocatalytic performance test by cyclic voltammetries in 0.1 mol/L KOH and 1 mol/L methanol electrolyte. Methanol oxidation peak current density of the Nanotube- Fe2(MoO43/GCEs electrode is 3.27 mA/cm2 higher than 2.8 mA/cm2 of platinum foil electrode, which shows enhanced catalytic activity of Nanotube-Fe2(MoO43/GCEs. The cyclic stability in terms of peak current retention are 91%, 92% and 88% respectively for Nanosphere-Fe2(MoO43/GCE, Nanorod-Fe2(MoO43/GCE and Nanotube-Fe2(MoO43/GCE electrode after 220 cycles. It is concluded that nanosized Fe2(MoO43 could be promising alternative non-noble electro-catalysts for electro-oxidation of methanol in alkaline medium.

  16. Growth of uniform lath-like α-(Fe,Al)OOH and disc-like α-(Fe,Al)2O3 nanoparticles in a highly alkaline medium

    International Nuclear Information System (INIS)

    Krehula, Stjepko; Music, Svetozar

    2010-01-01

    The effects of aluminium (Al 3+ )-dopant on the precipitation of uniform lath-like α-FeOOH particles, the obtention and growth of α-(Fe,Al)OOH and α-(Fe,Al) 2 O 3 solid solutions, particle size and shape were investigated using X-ray powder diffraction, Moessbauer and Fourier transform infrared spectroscopies, field emission scanning electron microscopy and energy dispersive X-ray spectroscopy. Acicular α-FeOOH particles, precipitated in a highly alkaline medium with the addition of tetramethylammonium hydroxide (TMAH), were used as reference material. The influence of Al-dopant was investigated by adding varying amounts of Al 3+ ions to the initial FeCl 3 solution. In the presence of lower concentrations of aluminium ions (up to 11.11 mol%) α-(Fe,Al)OOH as a single phase was formed, whereas higher concentrations led to an additional obtention and growth of α-(Fe,Al) 2 O 3 . Al-for-Fe substitution in the α-FeOOH and α-Fe 2 O 3 structures was confirmed by a decrease in the unit-cell dimensions, a decrease in the hyperfine magnetic field and an increase in the wave number of the infrared absorption bands. The presence of lower concentrations of aluminium ions (up to 11.11 mol%) in the precipitation system did not affect the size and shape of the α-(Fe,Al)OOH particles, whereas higher concentrations influenced a decrease in the length and aspect ratio. In the presence of 42.86 mol% Al 3+ ions fairly uniform disc-shaped α-(Fe,Al) 2 O 3 were formed.

  17. Preparation and characterization of electrocatalysts based on palladium for electro-oxidation of alcohols in alkaline medium; Preparacao e caracterizacao de eletrocatalisadores a base de paladio para oxidacao eletroquimica de alcoois em meio alcalino

    Energy Technology Data Exchange (ETDEWEB)

    Brandalise, Michele

    2012-07-01

    In this study Pd/C, Au/C, PdAu/C, PdAuPt/C, PdAuBi/C and PdAuIr/C electrocatalysts were prepared by the sodium borohydride reduction method for the electrochemical oxidation of methanol, ethanol and ethylene glycol. This methodology consists in mix an alkaline solution of sodium borohydride to a mixture containing water/isopropyl alcohol, metallic precursors and the Vulcan XC 72 carbon support. The electrocatalysts were characterized by energy dispersive X-ray (EDX), X-ray diffraction (XRD), transmission electron microscopy (TEM) and cyclic voltammetry. The electrochemical oxidation of the alcohols was studied by chronoamperometry using a thin porous coating technique. The mechanism of ethanol electro-oxidation was studied by Fourier Transformed Infrared (FTIR) in situ. The most effective electrocatalysts were tested in alkaline single cells directly fed with methanol, ethanol or ethylene glycol. Preliminary studies showed that the most suitable atomic composition for preparing the ternary catalysts is 50:45:05. Electrochemical data in alkaline medium show that the electrocatalysts PdAuPt/C (50:45:05) showed the better activity for methanol electro oxidation, while PdAuIr/C was the most active for ethanol oxidation and PdAuBi/C (50:45:05) was the most effective for ethylene glycol oxidation in alkaline medium. These results show that the addition of gold in the composition of electrocatalysts increases their catalytic activities. The spectroelectrochemical FTIR in situ data permitted to conclude that C-C bond is not broken and the acetate is formed. (author)

  18. Co{sub 3}O{sub 4}/TiO{sub 2} films obtained by laser ablation and sol-gel for the reaction of oxygen liberation in alkaline medium; Peliculas de Co{sub 3}O{sub 4}/TiO{sub 2} obtenidas por ablacion laser y sol-gel para la reaccion de desprendimiento de oxigeno en medio alcalino

    Energy Technology Data Exchange (ETDEWEB)

    Perez A, J.; Fernandez V, S. M.; Escobar A, L.; Jimenez B, J. [Departamento de Quimica, ININ, Carretera Mexico-Toluca s/n, Ocoyoacac, Estado de Mexico (Mexico)

    2008-07-01

    The laser ablation technique known as Pulsed Laser Deposition (PLD) is used for obtaining thin films of TiO{sub 2}/SnO{sub 2}, which was later modified with Co{sub 3}O{sub 4} by PLD or by sol-gel technique. The films were characterized by X-ray diffraction, ultraviolet Vis and Raman spectroscopies, scanning electron microscopy and energy analysis of the dispersed X-rays produced by Auger decay. The anatase phase with particles of nano metric size was obtained by depositing the titanium dioxide in argon atmosphere. The Co{sub 3}O{sub 4} films obtained by PLD on the TiO{sub 2} showed the same morphology. The electrocatalytic activity of the films that were used as photo anodes for the reaction of oxygen liberation was carried out in the darkness, with environment light and the light emitted by a xenon lamp. The current density was higher for films of Co{sub 3}O{sub 4}/TiO{sub 2}/SnO{sub 2} obtained by PLD that for cobalt dioxide of mixed valence obtained by sol-gel. (Author)

  19. Evaluation of nickel-rich alloys for the electrolytic generation of hydrogen in an alkaline medium; Evaluacion de aleaciones ricas en niquel para la generacion electrolitica de hidrogeno en medio alcalino

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz Verdin, A.A.; Ortega Borges, R.; Trejo Cordova, G.; Meas Vong, Y. [Centro de Investigacion y Desarrollo Tecnologico en Electroquimica, S.C., Pedro Escobedo, Queretaro (Mexico)]. E-mail: aortiz@cideteq.mx

    2009-09-15

    The simultaneous electrodeposition of Ni with metals such as Zn to form alloys enables obtaining surfaces with high electrocatalytic activity or particular characteristics that resist wear and abrasion. This work presents the results of the study of the electrochemical characterization of different types of nickel electrodeposition and compositions, used as cathodes, and measurements of the electrocatalytic activity in the release of hydrogen in an alkaline medium. Curves I through IV were generated, which were potentiostatically obtained in a nitrogen atmosphere in a NaOH alkaline solution. The morphology of the deposits was evaluated with sweep electron micrscopy(SEM). The results enabled evaluating its potential application as electrode materials for the generation of electrolytic hydrogen in alkaline medium, given the good electrocatalytic activity of nickel-rich materials. [Spanish] El electrodeposito simultaneo del Ni, con metales como el Zn para formar aleaciones, permite obtener superficies con elevada actividad electrocatalitica o con caracteristicas particulares de resistencia al desgaste y abrasion. En este trabajo se presentan los resultados del estudio de la caracterizacion electroquimica de los electrodepositos a base de niquel de diferente naturaleza y composicion utilizandolos como catodos midiendo la actividad electrocatalitica con respecto a la reaccion de desprendimiento de hidrogeno (RDH) en medio alcalino. Se realizaron curvas I vs V obtenidas potenciostaticamente bajo atmosfera de nitrogeno en una solucion alcalina de NaOH. La morfologia de los depositos se evaluo mediante SEM (microscopio electronico de barrido). Los resultados permiten evaluar su potencial aplicacion como materiales de electrodo para la generacion electrolitica de hidrogeno en medio alcalino, dada la buena actividad electrocatalitica de los materiales ricos en niquel.

  20. Effect of zinc phosphate chemical conversion coating on corrosion behaviour of mild steel in alkaline medium: protection of rebars in reinforced concrete

    International Nuclear Information System (INIS)

    Simescu, Florica; Idrissi, Hassane

    2008-01-01

    We outline the ability of zinc phosphate coatings, obtained by chemical conversion, to protect mild steel rebars against localized corrosion, generated by chloride ions in alkaline media. The corrosion resistance of coated steel, in comparison with uncoated rebars and coated and uncoated steel rebars embedded in mortar, were evaluated by open-circuit potential, potentiodynamic polarization, cronoamperometry and electrochemical impedance spectroscopy. The coated surfaces were characterized by x-ray diffraction and scanning electron microscopy. First, coated mild steel rebars were studied in an alkaline solution with and without chloride simulating a concrete pore solution. The results showed that the slow dissolution of the coating generates hydroxyapatite Ca 10 (PO 4 ) 6 (OH) 2 . After a long immersion, the coating became dense and provided an effective corrosion resistance compared with the mild steel rebar. Secondly, the coated and uncoated steel rebars embedded in mortar and immersed in chloride solution showed no corrosion or deterioration of the coated steel. Corrosion rate is considerably lowered by this phosphate coating.

  1. Development of PdM (M = Ni, Cu, Ag) electrocatalysts for oxygen reduction reaction in alkaline medium in the absence and presence of alcohol

    International Nuclear Information System (INIS)

    Isidoro, Roberta Alvarenga

    2015-01-01

    Pd/C, Pd Cu/C, Pd Ni/C and Pd Ag/C electrocatalysts were produced by microwave method to be used as cathode in alkaline fuel cell in the absence and presence of alcohol. This method showed to be effective for the materials production, the particles exhibited good dispersion in carbon support and it produced electrocatalysts with a particle size of about 3.5 nm, according to XRD and TEM analysis. In cyclic voltammetry is observed that Pd Cu/C and Pd Ni/C electrocatalysts has higher active area with higher amount of Cu and Ni, respectively. Rotating ring disk analysis in the electrocatalysts showed that the amount of peroxide produced was at most 4%. This data is similar to Koutecky-Levich analysis, once for both the ORR occurs via 4 electrons. Materials stability analysis showed that they kept or improve performance in ORR, comparing the data before and after 1000 voltammetric cycles. Tolerance tests in methanol and ethanol were performed in a half cell in all electrocatalysts compositions. In presence of methanol and ethanol the compositions 50:50, to all materials studied, showed less influence in the presence of alcohol in ORR linear scan. In alkaline fuel cell Pd Ag/C 70:30 showed better performance for ORR in presence of methanol and Pd Ni/C 70:30 showed better performance for ORR in ethanol presence. (author)

  2. Effect of zinc phosphate chemical conversion coating on corrosion behaviour of mild steel in alkaline medium: protection of rebars in reinforced concrete

    Directory of Open Access Journals (Sweden)

    Florica Simescu and Hassane Idrissi

    2008-01-01

    Full Text Available We outline the ability of zinc phosphate coatings, obtained by chemical conversion, to protect mild steel rebars against localized corrosion, generated by chloride ions in alkaline media. The corrosion resistance of coated steel, in comparison with uncoated rebars and coated and uncoated steel rebars embedded in mortar, were evaluated by open-circuit potential, potentiodynamic polarization, cronoamperometry and electrochemical impedance spectroscopy. The coated surfaces were characterized by x-ray diffraction and scanning electron microscopy. First, coated mild steel rebars were studied in an alkaline solution with and without chloride simulating a concrete pore solution. The results showed that the slow dissolution of the coating generates hydroxyapatite Ca10(PO46(OH2. After a long immersion, the coating became dense and provided an effective corrosion resistance compared with the mild steel rebar. Secondly, the coated and uncoated steel rebars embedded in mortar and immersed in chloride solution showed no corrosion or deterioration of the coated steel. Corrosion rate is considerably lowered by this phosphate coating.

  3. catalysed oxidation of atenolol by alkaline permanganate

    Indian Academy of Sciences (India)

    Unknown

    Abstract. Kinetics of ruthenium (III) catalyzed oxidation of atenolol by permanganate in alkaline medium at constant ionic strength of 0⋅30 mol dm3 has been studied spectrophotometrically using a rapid kinetic accessory. Reaction between permanganate and atenolol in alkaline medium exhibits 1 : 8 stoichiometry.

  4. Surface chemistry of pyrite during the pre-processing for the flotation in alkaline sodium carbonate medium during uranium ore processing

    International Nuclear Information System (INIS)

    Neudert, A.; Sommer, H.; Schubert, H.

    1991-01-01

    It is often necessary during processing of uranium ore to flotate pyrite at sodium carbonate alkaline pH value caused by the subsequent hydrometallurgical process stages. It was found out by ESCA analyses that the pyrite surface changes chemically prior to the addition of flotation agents. FeS 2 becomes FeO within a few hours in the case of storage in process water; limonite and/or geothite result from pyrite. The copper ions of the activator CuSO 4 are exclusively monovalent on the pyrite surface. The resulting heavy metal xanthogenate is Cu(I) xanthogenate. Conclusions are derived for the flotation practice for the intensification of the reagent regime. (orig./HP) [de

  5. Methodology of analysis of very weak acids by isotachophoresis with electrospray-ionization mass-spectrometric detection: Anionic electrolyte systems for the medium-alkaline pH range.

    Science.gov (United States)

    Malá, Zdena; Gebauer, Petr

    2018-01-15

    This work describes for the first time a functional electrolyte system setup for anionic isotachophoresis (ITP) with electrospray-ionization mass-spectrometric (ESI-MS) detection in the neutral to medium-alkaline pH range. So far no application was published on the analysis of very weak acids by anionic ITP-MS although there is a broad spectrum of potential analytes with pK a values in the range 5-10, where application of this technique promises interesting gains in both sensitivity and specificity. The problem so far was the lack of anionic ESI-compatible ITP systems in the mentioned pH range as all typical volatile anionic system components are fully ionized at neutral and alkaline pH and thus too fast to suit as terminators. We propose an original solution of the problem based on the combination of two ITP methods: (i) use of the hydroxyl ion as a natural and ESI-compatible terminator, and (ii) use of configurations based on moving-boundary ITP. The former method ensures effective stacking of analytes by an alkaline terminator of sufficiently low mobility and the latter offers increased flexibility for tuning of the separation window and selectivity according to actual needs. A theoretical description of the proposed model is presented and applied to the design of very simple functional electrolyte configurations. The properties of example systems are demonstrated by both computer simulation and experiments with a group of model analytes. Potential effects of carbon dioxide present in the solutions are demonstrated for particular systems. Experimental results confirm that the proposed methodology is well capable of performing sensitive and selective ITP-MS analyses of very weak acidic analytes (e.g. sulfonamides or chlorophenols). Copyright © 2017 Elsevier B.V. All rights reserved.

  6. A McOndo Writer's Take on Literature in the Era of Audiovisual and Digital Communication: The Case of Alberto Fuguet's "Las Peliculas de mi vida"

    Science.gov (United States)

    Maier, Linda S.

    2011-01-01

    Alberto Fuguet, one of the leaders of the McOndo writers who seek cultural direction from the United States and exploit mass-media formulas, is a polarizing figure in contemporary Latin American culture. His most recent full-length novel, the semi-autobiographical "Las peliculas de mi vida" (2003), has led many to conclude that Fuguet is simply a…

  7. Glycerol electro-oxidation in alkaline medium using Pd/C and PdSn/C electrocatalysts prepared by electron beam irradiation

    International Nuclear Information System (INIS)

    Geraldes, Adriana Napoleao; Silva, Dionisio Fortunato da; Pino, Eddy Segura; Spinace, Estevan Vitorio; Oliveira Neto, Almir; Linardi, Marcelo; Santos, Mauro Coelhos dos

    2013-01-01

    Carbon-supported metal nanoparticles were prepared for fuel cell applications by radiation-induced reduction of metal ions precursors. Pd/C and PdSn/C electrocatalysts (Pd:Sn atomic ratio 90:10), prepared by using electron beam irradiation, were tested for glycerol electro-oxidation in single alkaline direct glycerol fuel cell (ADGFC). EDX analysis showed that the Pd:Sn atomic ratio is very similar to the nominal one. X-ray diffractograms of PdSn/C electrocatalyst showed the presence of Pd (fcc) phase. Cyclic voltammetry (CV) indicated that Pd/C and PdSn/C electrocatalysts have good activity for glycerol electro-oxidation, at room temperature. Experiments with single ADGFC were carried out from 60 to 90 deg C, using Pd/C and PdSn/C electrocatalysts and glycerol 2.0 mol.L -1 , as fuel. The best performance was obtained at 85 deg C, for both electrocatalysts. The Pd/C and PdSn/C electrocatalysts showed similar performance (34 mW cm -2 ), at 85 deg C. (author)

  8. A comparative investigation of metal-support interactions on the catalytic activity of Pt nanoparticles for ethanol oxidation in alkaline medium

    Science.gov (United States)

    Godoi, Denis R. M.; Villullas, Hebe M.; Zhu, Fu-Chun; Jiang, Yan-Xia; Sun, Shi-Gang; Guo, Junsong; Sun, Lili; Chen, Rongrong

    2016-04-01

    The effects of interactions of Pt nanoparticles with hybrid supports on reactivity towards ethanol oxidation in alkaline solution are investigated. Studies involve catalysts with identical Pt nanoparticles on six hybrid supports containing carbon powder and transition metal oxides (TiO2, ZrO2, SnO2, CeO2, MoO3 and WO3). In situ X-ray absorption spectroscopy (XAS) results evidence that metal-support interactions produce changes in the Pt 5d band vacancy, which appears to determine the catalytic activity. The highest and lowest activities are observed for Pt nanoparticles on hybrid supports containing TiO2 and CeO2, respectively. Further studies are presented for these two catalysts. In situ FTIR reflection spectroscopy measurements, taken using both multi-stepped FTIR spectroscopy (MS-FTIR) and single potential alteration FTIR spectroscopy (SPA-FTIR), evidence that the main product of ethanol oxidation is acetate, although signals attributed to carbonate and CO2 indicate some differences in CO2 production. Fuel cell performances of these catalysts, tested in a 4.5 cm2 single cell at different temperatures (40-90 °C) show good agreement with data obtained by electrochemical techniques. Results of this comprehensive study point out the possibility of compensating a reduction of noble metal load with an increase in activity promoted by interactions between metallic nanoparticles and a support.

  9. Electrochemical oxidation of ethanol using PtRh/C electrocatalysts in alkaline medium and synthesized by sodium borohydride and alcohol reduction

    International Nuclear Information System (INIS)

    Fontes, Eric Hossein

    2017-01-01

    PtRh/C were prepared by the following atomic proportions: (100,0), (0,100), (90,10), (70,30) and (50,50). The methods employed in the synthesis of these materials were reduction by sodium borohydride and reduction by alcohol. The metal salts used were H 2 PtCl 6 3•6H 2 0 and (RhNO 3 ) 3 , the support used was Carbon black XC72 and the bulk metal composition was 20% and 80% of support. The electrocatalysts were characterized by Energy Dispersive X-ray spectroscopy, X-ray diffraction and Transmission electron microscopy. The ethanol electrochemical oxidation mechanism was investigated by in situ Fourier Transform Infrared Spectroscopy couple to an Attenuated Total Reflection technique. The electrocatalytic activity were evaluated by Cyclic Voltammetry, Linear Sweep Voltammetry and Chronoamperometry techniques. The Fuel Cells tests were made in a single direct alcohol fuel cell with alkaline membrane. The working electrodes were prepared by a thin porous coating technique. X-ray diffraction allowed to verify metallic alloys, segregate phases and to calculate the percentage of metallic alloys. It was else possible to identify crystallographic phases. Infrared Spectroscopy allowed to verify that the electrochemical oxidation of ethanol was carried out by an incomplete mechanism. PtRh(70:30)/C prepared by sodium borohydride produced large amounts of carbon dioxide and acetaldehyde. Rh/C showed electrocatalytic activity when compared with other materials studied.

  10. CaCu3Ti4O12: A Bifunctional Perovskite Electrocatalyst for Oxygen Evolution and Reduction Reaction in Alkaline Medium

    International Nuclear Information System (INIS)

    Kushwaha, H.S.; Halder, Aditi; Thomas, P.; Vaish, Rahul

    2017-01-01

    Highlights: •A cost effective double perovskite CaCu 3 Ti 4 O 12 have been synthesized using oxalate precursor method. •CCTO electrocatalyst exhibit enhanced bifunctional electrocatalytic activities. •CCTO electrocatalyst have lower overpotential and higher mass activity as compared to noble metal oxide and well-known perovskite catalysts. •Electrochemical impedance spectroscopy investigations of oxygen reactions on perovskite surfaces. -- Abstract: Perovskite oxides are prominent materials as the bifunctional electrocatalysts for both oxygen reduction/evolution reactions (ORR/OER) for the electrochemical energy conversion and storage using regenerative fuel cells and rechargeable metal-air batteries. In this work, a quadruple perovskite CaCu 3 Ti 4 O 12 has been synthesized oxalate precursor route. X-ray diffraction pattern shows phase purity of the synthesized electrocatalyst. The synthesized CCTO electrocatalyst have crystallite size of 26 nm. Electrochemical investigations reveal that CCTO exhibit efficient catalytic activity. More interestingly, an extremely high OER activity is observed for CCTO electrocatalysts which is found superior than similar class of perovskites. Additionally, CCTO shows efficient ORR activity with an onset potential of 0.83 V which is better than that of Pt/C catalyst (≈0.94 V). These results demonstrate the significant potential of CCTO perovskite as a bifunctional electrode material for alkaline fuel cells and metal-air batteries.

  11. A sensitive inhibition chemiluminescence method for the determination of 6-mercaptopurine in tablet and biological fluid using the reaction of luminol-Ag(III) complex in alkaline medium

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Hanwen, E-mail: hanwen@hbu.edu.cn [College of Chemistry and Environmental Science, Hebei University, Key Laboratory of Analytical Science and Technology of Hebei Province, Baoding 071002 (China); Wang, Ting; Liu, Xuyang; Chen, Peiyun [College of Chemistry and Environmental Science, Hebei University, Key Laboratory of Analytical Science and Technology of Hebei Province, Baoding 071002 (China)

    2013-02-15

    A sensitive inhibition chemiluminescence (CL) method for the determination of 6-mercaptopurine (6-MP) is developed. The mechanism of the CL reaction between Ag(III) complex {l_brace}[Ag(HIO{sub 6}){sub 2}]{sup 5-}{r_brace} and luminol in alkaline solution was proposed, along with the inhibition mechanism of 6-MP on the CL emission. The inhibition degree of CL emission was proportional to the logarithm of 6-MP concentration. The effects of the reaction conditions on CL emission and inhibition were examined. Under the optimized conditions, the detection limit (s/n=3) was 3.7 Multiplication-Sign 10{sup -10} g ml{sup -1}. The recoveries of 6-MP were in the range of 97.7-105% with the RSD of 2.1-3.4% (n=5) for tablet samples, 103-106% with the RSDs of 1.1-2.1% for spiked serum sample, and 97.2-101% with the RSD of 2.0-4.5% for spiked urine sample. The accuracy of this method for the tablet analysis was examined by comparing with the pharmacopoeia method. The proposed method was used for the determination of 6-MP at clinically relevant concentrations in real urine and serum samples with satisfactory results. - Highlights: Black-Right-Pointing-Pointer A sensitive inhibition chemiluminescence (CL) method for the determination of 6-MP is developed. Black-Right-Pointing-Pointer The inhibition mechanism of 6-MP on the CL emission was proposed. Black-Right-Pointing-Pointer The detection limit was 3.7 Multiplication-Sign 10{sup -10} g ml{sup -1}. Black-Right-Pointing-Pointer The accuracy was examined by comparing with the pharmacopoeia method.

  12. Degradation of amaranth dye in alkaline medium by ultrasonic cavitation coupled with electrochemical oxidation using a boron-doped diamond anode

    International Nuclear Information System (INIS)

    Barros, Willyam R.P.; Steter, Juliana R.; Lanza, Marcos R.V.; Motheo, Artur J.

    2014-01-01

    Amaranth dye is used widely in the processing of paper, textiles, foods, cosmetics, beverages and medicines, and effluents contaminated with this compound are discharged daily into the environment. Recent studies have shown that azo dyes, especially those such as amaranth dye that have been classified as endocrine disruptors, may cause adverse effects to animal and human health. This paper describes the application of electrochemical oxidation (with a boron-doped diamond BDD thin-film anode) coupled with ultrasound sonolysis (20 kHz and 523 W cm −2 ) to the removal of amaranth dye from dilute alkaline solution. The electrochemical and sonoelectrochemical processes (ECh and SECh, respectively) were carried out at constant current density (10 to 50 mA cm −2 ) in a single compartment cylindrical cell. Sonolysis was virtually less useful for the decolorization and degradation of amaranth dye, whilst ECh and SECh were more effective in degrading the dye with almost complete removal (90 - 95%) attained after 90 min of experiment at an applied current density of 50 mA cm −2 . Degradation of the dye followed pseudo first-order kinetics in both processes, but the rate of reaction was faster with the SECh treatment confirming a synergistic effect between the cavitation process and the electrochemical system. Additionally, at low applied current densities (10 and 25 mA cm −2 ), SECh was considerably more effective than ECh for the amaranth dye mineralization. Although at 35 and 50 mA cm −2 , the two processes showed the respective removal of total organic carbon values: (i) 85% for the ECh and 90% for the SECh at 35 mA cm −2 ; (ii) 96% for the ECh and 98% for the SECh at 50 mA cm −2 . It is concluded that SECh presented the most favorable results for the decontamination of wastewaters containing azo dye compounds

  13. Study of Tl0(1) and In0(1) defects in alkaline halides: prototype of a color center as active laser medium

    International Nuclear Information System (INIS)

    Vieira Junior, N.D.

    1986-01-01

    The optical properties of the Tl 0 (1) and In 0 (1) centers in Kcl crystals in cation sites of the crystal lattice, perturbed by an adjacent anion vacancy. Emphasis is given to the lowest energy levels. Using a tagging optical absorption technique, the absorption bands were identified. The laser action of Tl 0 (1) center in KCl by pumping with Nd: YAG laser in the lowest energy absorption band was obtained. A simple way to achieve continuous single frequency laser operation using a grating as the sole tuning element is described. It is shown that, by proper choice of cavity parameters, the competing hole burning modes can be completely supressed. Experiments were carried out using Tl 0 (1) centers in KCl as the gain medium. The production of pulses via synchronous pumping of Tl 0 (1) color center in KCl are reported. (author) [pt

  14. Controlled synthesis of La{sub 1−x}Sr{sub x}CrO{sub 3} nanoparticles by hydrothermal method with nonionic surfactant and their ORR activity in alkaline medium

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Bo Hyun; Park, Shin-Ae [Energy System Major, School of Mechanical Engineering, Pusan National University, Busan 609-735 (Korea, Republic of); Park, Bong Kyu [GIFT Center, Pusan National University, Busan, 609-735 (Korea, Republic of); Chun, Ho Hwan, E-mail: chunahh@pusan.ac.kr [Global Core Research Center for Ships and Offshore Plants(GCRC-SOP), Pusan National University, Busan, 609-735 (Korea, Republic of); Kim, Yong-Tae, E-mail: yongtae@pusan.ac.kr [Energy System Major, School of Mechanical Engineering, Pusan National University, Busan 609-735 (Korea, Republic of)

    2013-10-15

    Graphical abstract: We demonstrate that Sr-doped LaCrO{sub 3} nanoparticles were successfully prepared by the hydrothermal synthesis method using the nonionic surfactant Triton X-100 and the applicability of La{sub 1−x}Sr{sub x}CrO{sub 3} to oxygen reduction reaction (ORR) electrocatalysis in an alkaline medium. Compared with the nanoparticles synthesized by the coprecipitation method, they showed enhanced ORR activity. - Highlights: • Sr-doped LaCrO{sub 3} nanoparticles were successfully prepared by the hydrothermal method using the nonionic surfactant. • Homogeneously shaped and sized Sr-doped LaCrO{sub 3} nanoparticles were readily obtained. • Compared with the nanoparticles synthesized by the coprecipitation method, they showed an enhanced ORR activity. • The main origin was revealed to be the decreased particle size due to the nonionic surfactant. - Abstract: Sr-doped LaCrO{sub 3} nanoparticles were prepared by the hydrothermal method with the nonionic surfactant Triton X-100 followed by heat treatment at 1000 °C for 10 h. The obtained perovskite nanoparticles had smaller particle size (about 100 nm) and more uniform size distribution than those synthesized by the conventional coprecipitation method. On the other hand, it was identified with the material simulation that the electronic structure change by Sr doping was negligible, because the initially unfilled e{sub g}-band was not affected by the p-type doping. Finally, the perovskite nanoparticles synthesized by hydrothermal method showed much higher ORR activity by over 200% at 0.8 V vs. RHE than those by coprecipitation method.

  15. Photo and cathode luminescence emission in oxide silicium films implanted with silicium; Emision de foto y catodoluminiscencia en peliculas de oxido de silicio termico implantadas con silicio

    Energy Technology Data Exchange (ETDEWEB)

    Flores, F; Aceves, M. [Instituto Nacional de Astrofisica Optica y Electronica, Mexico, D.F. (Mexico); Carrillo, J. [Benemrita Universidad Autonoma de Puebla, Puebla (Mexico); Dominguez, C. [Universida Autonoma de Barcelona, Barcelona (Spain); Falcony, C. [Instituto Politecnico Nacional, Mexico, D.F. (Mexico)

    2001-10-01

    We studied the photo and cathodoluminescence of Silicon Rich Oxides (SRO) obtained by ion implant of Si in thermal oxides. Doses of 10{sup 1}6 cm{sup -}2 (low dose) and 10{sup 1}7 cm{sup -}2 (high dose) and implant energy of 150 keV were used. The films were annealed for 30, 60 and 180 minutes in nitrogen at 1100 Celsius degrees. The spectra show photo and cathodoluminescence emission in the visible range, the bands in the spectra change with the conditions of ion implant and annealing. The films without thermal treatment in both dose present photoluminescence bands around 1.9 eV (band B) and 2.4 eV (band C). With the thermal treatments, the band B disappears. In the case of the films with low dose, the band C shows a blue shift and a decrease in intensity. The high dose films have a band centered in 1.7 eV (band A) that increases its intensity with annealings. The cathodoluminescence bands in all the cases are in 2.7 eV (band D) and they present changes with the thermal treatments that it seems they depend on the variation in the implant parameters. [Spanish] Se estudian las propiedades de foto y la catodoluminiscencia de peliculas de oxidos de silicio ricos en Si (Silicon Rich Oxide SRO) obtenidas por implantacion ionica de Si en oxidos termicos. Se usaron dosis de 10{sup 1}6 cm{sup -}2 (dosis baja) y 10{sup 1}7 cm{sup -}2 (dosis alta) y energia de implantacion de 150 keV. Las peliculas se sometieron a tratamientos termicos por 30, 60 y 180 minutos en nitrogeno de 1100 grados centigrados. Se encontro emision foto y catodoluminiscente en el rango visible, las bandas en los espectros cambian con las condiciones de implantacion ionica y con los tratamientos termicos. Las peliculas sin tratamiento termico en ambas dosis presentan bandas de fotoluminiscencia alrededor de 1.9 eV (banda B) y 2.4 eV (banda C). Con los tratamientos termicos, la banda B desaparece. En el caso de las peliculas con dosis baja, la banda C muestra un corrimiento hacia el azul junto con una

  16. Guest–host interactions in the alkaline bleaching of ...

    Indian Academy of Sciences (India)

    Administrator

    cyclodextrin on the bleaching rates of triphenylmethane dyes crystal violet (CV), malachite green (MG) and rosaniline. (RA) have been investigated in alkaline medium with a view to understand the guest–host interaction in these system. 2.

  17. Time dependence of the natural passivation process on AISI 304 in an alkaline medium: Atomic force microscopy and scanning Kelvin probe force microscopy as additional tools to electrochemical impedance spectroscopy

    Science.gov (United States)

    Benaioun, N. E.; Maafa, I.; Florentin, A.; Denys, E.; Hakiki, N. E.; Moulayat, N.; Bubendorff, J. L.

    2018-04-01

    Thin surface films formed on AISI 304 samples in an alkaline solution of pH = 13 are studied by atomic force microscopy (AFM), scanning Kelvin probe force microscopy (SKPFM) and electrochemical impedance spectroscopy (EIS) as a function of immersion time. The results reveal that changes on EIS diagrams correspond to topographical modifications on the sample surface as shown by AFM. Both techniques are therefore complementary. The oxide layer is chemically homogenous as shown by SKPFM imaging and our ultra-thin passive layer is an efficient barrier against corrosion.

  18. Alkaline azide mutagenicity in cowpea

    Energy Technology Data Exchange (ETDEWEB)

    Mahna, S K; Bhargava, Anubha; Mohan, Lalit [Cytogenetics and Mycology Laboratory, Department of Botany, Government College, Ajmer (India)

    1990-07-01

    Sodium azide is known as a potent mutagen in cereals and legumes. It is very effective in acidic medium in barley. Here an attempt is made to measure the effectiveness of sodium azide in alkaline medium (pH 7.4) on cowpea (Vigna unguiculata (L.) Walp., variety FS-68). Seeds pre-soaked in distilled water for 5 hours were treated with different concentrations (10{sup -6}, 10{sup -5}, 10{sup -4} and 10{sup -3}M) of sodium azide (NaN{sub 3}) for 4 hours at 28{+-} 2 deg. C. Bottles were intermittently shaken, then the seeds were thoroughly washed in running tap water and subsequently planted in pots. The treatment caused significant biological damage such as reduction in seed germination, length of root and shoot, number of nodules and pods per plant and morphological leaf variations. Morphological, as well as chlorophyll mutants, were detected in M{sub 2}.

  19. Alkaline azide mutagenicity in cowpea

    International Nuclear Information System (INIS)

    Mahna, S.K.; Bhargava, Anubha; Mohan, Lalit

    1990-01-01

    Sodium azide is known as a potent mutagen in cereals and legumes. It is very effective in acidic medium in barley. Here an attempt is made to measure the effectiveness of sodium azide in alkaline medium (pH 7.4) on cowpea (Vigna unguiculata (L.) Walp., variety FS-68). Seeds pre-soaked in distilled water for 5 hours were treated with different concentrations (10 -6 , 10 -5 , 10 -4 and 10 -3 M) of sodium azide (NaN 3 ) for 4 hours at 28± 2 deg. C. Bottles were intermittently shaken, then the seeds were thoroughly washed in running tap water and subsequently planted in pots. The treatment caused significant biological damage such as reduction in seed germination, length of root and shoot, number of nodules and pods per plant and morphological leaf variations. Morphological, as well as chlorophyll mutants, were detected in M 2

  20. Substrate temperature study in the crystallinity of BaTiO{sub 3} thin films; Estudio de la temperatura de crecimiento sobre la cristalinidad en peliculas delgadas de BaTiO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Marquez-Herrera, Alfredo [Coordinacion Academica Region Altiplano (COARA), Universidad Autonoma de San Luis Potosi, San Luis Potosi (Mexico)]. E-mail: amarquez@mixteco.utm.mx; Hernandez-Rodriguez, Eric Noe; Zapata-Torres, Martin Guadalupe [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Unidad Legaria, Instituto Politecnico Nacional (Mexico)]. E-mails: noehmx@hotmail.com; mzapatat@ipn.mx; Cruz-Jauregui, Maria de la Paz [Centro de Nanociencias y Nanotecnologia, Universidad Nacional Autonoma de Mexico (Mexico)]. E-mail: mcruz@cnyn.unam.mx; Melendez-Lira, Miguel angel [Centro de Investigacion y de Estudios Avanzados, Instituto Politecnico Nacional (Mexico)]. E-mail: mlira@fis.cinvestav.mx

    2013-07-15

    Ferroelectric thin films of BaTiO{sub 3} (BTO) were grown on quartz and nichrome substrates using a BaTiO{sub 3} target by RF-Sputtering technique. It was studied the effect of the substrate temperature in the crystallization of the material. These samples were compared with films deposited at room temperature and heat treated out of the growth Chamber. Their crystallinity were studied by X-ray diffraction. Additionally, the optical characterizations were carried out by UV-Vis spectrophotometer. The growth of thin films with substrate temperature allows the obtaining of crystalline materials at temperatures below those reported by other authors. [Spanish] Peliculas delgadas Ferroelectricas de BaTiO{sub 3} (BTO) se depositaron a partir de un blanco de BaTiO{sub 3} mediante la tecnica de RF-Sputtering (erosion catodica por radio frecuencia) sobre substratos de nicromel y cuarzo. Se estudio el efecto de la temperatura de sustrato in-situ en la cristalinidad del material durante su deposito. Estas muestras fueron comparadas con peliculas depositadas a temperatura ambiente y tratadas termicamente posterior al deposito fuera de la camara de crecimiento. El estudio de la cristalinidad fue realizado mediante la tecnica de difraccion de rayos-X. Adicionalmente, se llevaron a cabo caracterizaciones opticas mediante un espectrofotometro UV-Vis. El crecimiento de peliculas delgadas con temperatura de sustrato permite la obtencion de materiales cristalinos a temperaturas por debajo de las reportadas por otros autores.

  1. Analysis of the passive layer developed on stainless steels implanted with chromium; Analisis de las peliculas pasivas generadas en aceros inoxidables implantados con cromo

    Energy Technology Data Exchange (ETDEWEB)

    Abreu, C. M.; Cristobal, M. J.; Novoa, X. R.; Pena, G.; Perez, M. C.

    2004-07-01

    This work studies the effect of chromium implantation on the development of passive layers generated electrochemically in alkaline medium over two stainless steels. The XPS analyses show that the layers generated on the implanted steels present less thickness together with similar composition compared to the unimplanted steels layers. However, SEM micrographs show that the layers grown on implanted steels present more defects and less adherence that the films on unimplanted steels. These changes together with the results obtained by Cyclic Voltammetry suggest an oxide structure modification, lattice structure or crystallinity state. (Author) 6 refs.

  2. Uranium in alkaline rocks

    International Nuclear Information System (INIS)

    Murphy, M.; Wollenberg, H.; Strisower, B.; Bowman, H.; Flexser, S.; Carmichael, I.

    1978-04-01

    Geologic and geochemical criteria were developed for the occurrence of economic uranium deposits in alkaline igneous rocks. A literature search, a limited chemical analytical program, and visits to three prominent alkaline-rock localities (Ilimaussaq, Greenland; Pocos de Caldas, Brazil; and Powderhorn, Colorado) were made to establish criteria to determine if a site had some uranium resource potential. From the literature, four alkaline-intrusive occurrences of differing character were identified as type-localities for uranium mineralization, and the important aspects of these localities were described. These characteristics were used to categorize and evaluate U.S. occurrences. The literature search disclosed 69 U.S. sites, encompassing nepheline syenite, alkaline granite, and carbonatite. It was possible to compare two-thirds of these sites to the type localities. A ranking system identified ten of the sites as most likely to have uranium resource potential

  3. Uranium in alkaline rocks

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, M.; Wollenberg, H.; Strisower, B.; Bowman, H.; Flexser, S.; Carmichael, I.

    1978-04-01

    Geologic and geochemical criteria were developed for the occurrence of economic uranium deposits in alkaline igneous rocks. A literature search, a limited chemical analytical program, and visits to three prominent alkaline-rock localities (Ilimaussaq, Greenland; Pocos de Caldas, Brazil; and Powderhorn, Colorado) were made to establish criteria to determine if a site had some uranium resource potential. From the literature, four alkaline-intrusive occurrences of differing character were identified as type-localities for uranium mineralization, and the important aspects of these localities were described. These characteristics were used to categorize and evaluate U.S. occurrences. The literature search disclosed 69 U.S. sites, encompassing nepheline syenite, alkaline granite, and carbonatite. It was possible to compare two-thirds of these sites to the type localities. A ranking system identified ten of the sites as most likely to have uranium resource potential.

  4. Alkaline earth metals

    International Nuclear Information System (INIS)

    Brown, Paul L.; Ekberg, Christian

    2016-01-01

    The beryllium ion has a relatively small ionic radius. As a consequence of this small size, its hydrolysis reactions begin to occur at a relatively low pH. To determine the stability and solubility constants, however, the Gibbs energy of the beryllium ion is required. In aqueous solution calcium, like the other alkaline earth metals, only exists as a divalent cation. The size of the alkaline earth cations increases with increasing atomic number, and the calcium ion is bigger than the magnesium ion. The hydrolysis of barium(II) is weaker than that of strontium(II) and also occurs in quite alkaline pH solutions, and similarly, only the species barium hydroxide has been detected. There is only a single experimental study on the hydrolysis of radium. As with the stability constant trend, it would be expected that the enthalpy of radium would be lower than that of barium due to the larger ionic radius.

  5. Advanced alkaline water electrolysis

    International Nuclear Information System (INIS)

    Marini, Stefania; Salvi, Paolo; Nelli, Paolo; Pesenti, Rachele; Villa, Marco; Berrettoni, Mario; Zangari, Giovanni; Kiros, Yohannes

    2012-01-01

    A short review on the fundamental and technological issues relevant to water electrolysis in alkaline and proton exchange membrane (PEM) devices is given. Due to price and limited availability of the platinum group metal (PGM) catalysts they currently employ, PEM electrolyzers have scant possibilities of being employed in large-scale hydrogen production. The importance and recent advancements in the development of catalysts without PGMs are poised to benefit more the field of alkaline electrolysis rather than that of PEM devices. This paper presents our original data which demonstrate that an advanced alkaline electrolyzer with performances rivaling those of PEM electrolyzers can be made without PGM and with catalysts of high stability and durability. Studies on the advantages/limitations of electrolyzers with different architectures do show how a judicious application of pressure differentials in a recirculating electrolyte scheme helps reduce mass transport limitations, increasing efficiency and power density.

  6. Carbon supported Pd-Ni and Pd-Ru-Ni nanocatalysts for the alkaline direct ethanol fuel cell (DEFC)

    CSIR Research Space (South Africa)

    Modibedi, M

    2011-09-01

    Full Text Available be improved by operating DAFCs in alkaline medium. Moreover, catalyst materials that are much cheaper and more abundant than Pt can be used for ethanol electro-oxidation and oxygen reduction reactions in alkaline DAFCs. Furthermore, the alkaline DAFCs use...

  7. An oxidant, detergent and salt stable alkaline protease from Bacillus ...

    African Journals Online (AJOL)

    A novel soil bacterium, Bacillus cereus SIU1 was earlier isolated from non-saline, slightly alkaline soil of Eastern Uttar Pradesh, India. The isolate B. cereus SIU1 was grown in modified glucose yeast extract (modified GYE) medium at pH 9.0 and 45°C. It produced maximum protease at 20 h incubation. The enzyme was ...

  8. Production of alkaline proteases by alkalophilic Bacillus subtilis ...

    African Journals Online (AJOL)

    Among various nitrogen sources, yeast extract was found to be the best inducer of alkaline protease. Among metal salts, KNO3 and NH4Cl were found to increase protease production. The maximum enzyme production (3600 U/ml) was observed with pomegranate peels of fermentation medium in the presence of yeast ...

  9. Electrochemical oxidation and detection of sodium urate in alkaline ...

    African Journals Online (AJOL)

    Electrochemical behaviour of copper oxides electrode in the presence of sodium urate was investigated. The correlation between the anodic oxidation and the amperometric detection of sodium urate in the alkaline medium on copper oxides electrode was analysed by cyclic voltammetry (CV) and electrochemical ...

  10. Absorbing materials of thin film for photovoltaic structures prepared by the process of pyrolytic spraying; Materiales absorbedores en pelicula delgada para estructuras fotovoltaicas preparados por el proceso de rocio pirolitico

    Energy Technology Data Exchange (ETDEWEB)

    Calixto Rodriguez, Manuela

    2006-11-15

    In this thesis work thin semiconducting films were grown with the following compounds: In{sub 2}S{sub 3}, Ag{sub 2}S, AgInS{sub 2}, SnS{sub 2} and SnS with the pyrolytic spray technique. The structural, optical and electrical proposals of these films were analyzed to determine the set of deposit parameters in which are obtained the physical properties for the applications of the same in photovoltaic structures. It was found that the molar relation in solution of the departing compounds and the deposit temperature are the same dominant parameters in the process of growing the films. For the deposit of thin films of Indio acetate were used and N, N-dimetil tiourea as precursory compounds of In and S, respectively. Polycrystalline films were obtained from the compound In{sub 2}S{sub 3} using underlying temperatures, Ts, between 400 and 450 degrees Celsius, and Indio acetate solutions and N, N-dimetil tiourea with molar relations (In:S) of 1:8 and 1:1. The energy breach, Eg, of these films varies from 2.04 to 2.67 eV, and the value of the conductivity in the darkness, D varies from 10-7 to 1(cm)-1 in function of the molar relation in solution. It was found that the deposited films using a molar relation of In:S=1:8 are of intrinsic nature independently of Ts, while the ones deposited using a molar relations of In:S=1:1 and Ts 400 degrees Celsius posses type-n conductivity. Using the molar relation of I:S=1:1 and Ts=500 degrees Celsius the compound polycrystalline of In{sub 2}O{sub 3} is obtained whose optical and electrical properties are Eg {approx} 3 eV and D=11 (cm)-1, with electrical conductivity type-n. The deposited films using a molar relation of In:S=1:1 and Ts=450 degrees Celsius are the ones that keep the appropriate characteristics for their use as type-n material in photovoltaic structures (Eg=2eV and D=1?-1 com-1). [Spanish] En este trabajo de tesis se crecieron peliculas delgadas semiconductoras de los compuestos: In{sub 2}S{sub 3}, Ag{sub 2}S, Ag

  11. Alkalinity of the Mediterranean Sea

    OpenAIRE

    Schneider, Anke; Wallace, Douglas W.R.; Körtzinger, Arne

    2007-01-01

    Total alkalinity (AT) was measured during the Meteor 51/2 cruise, crossing the Mediterranean Sea from west to east. AT concentrations were high (∼2600 μmol kg−1) and alkalinity-salinity-correlations had negative intercepts. These results are explained by evaporation coupled with high freshwater AT inputs into coastal areas. Salinity adjustment of AT revealed excess alkalinity throughout the water column compared to mid-basin surface waters. Since Mediterranean waters are supersaturated with r...

  12. Alkaline fuel cells applications

    Science.gov (United States)

    Kordesch, Karl; Hacker, Viktor; Gsellmann, Josef; Cifrain, Martin; Faleschini, Gottfried; Enzinger, Peter; Fankhauser, Robert; Ortner, Markus; Muhr, Michael; Aronson, Robert R.

    On the world-wide automobile market technical developments are increasingly determined by the dramatic restriction on emissions as well as the regimentation of fuel consumption by legislation. Therefore there is an increasing chance of a completely new technology breakthrough if it offers new opportunities, meeting the requirements of resource preservation and emission restrictions. Fuel cell technology offers the possibility to excel in today's motive power techniques in terms of environmental compatibility, consumer's profit, costs of maintenance and efficiency. The key question is economy. This will be decided by the costs of fuel cell systems if they are to be used as power generators for future electric vehicles. The alkaline hydrogen-air fuel cell system with circulating KOH electrolyte and low-cost catalysed carbon electrodes could be a promising alternative. Based on the experiences of Kordesch [K. Kordesch, Brennstoffbatterien, Springer, Wien, 1984, ISBN 3-387-81819-7; K. Kordesch, City car with H 2-air fuel cell and lead-battery, SAE Paper No. 719015, 6th IECEC, 1971], who operated a city car hybrid vehicle on public roads for 3 years in the early 1970s, improved air electrodes plus new variations of the bipolar stack assembly developed in Graz are investigated. Primary fuel choice will be a major issue until such time as cost-effective, on-board hydrogen storage is developed. Ammonia is an interesting option. The whole system, ammonia dissociator plus alkaline fuel cell (AFC), is characterised by a simple design and high efficiency.

  13. Overexpression of Human Bone Alkaline Phosphatase in Pichia Pastoris

    Science.gov (United States)

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

    Science.gov (United States)

    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.

  15. Method of cleaning alkaline metal

    International Nuclear Information System (INIS)

    Kawakami, Yukio; Naito, Kesahiro; Iizawa, Katsuyuki; Nakasuji, Takashi

    1981-01-01

    Purpose: To prevent scattering of used sodium and aqueous alkaline solution when cleaning used sodium and metallic sodium adhering to equipment with an aqueous alkaline solution. Method: A sodium treating container is filled with an aqueous alkaline solution, and stainless steel gauze is sunk in the container. Equipment to be cleaned such as equipment with sodium adhering to it are retained under the gauze and are thus cleaned. On the other hand, the surface of the aqueous alkaline solution is covered with a fluid paraffin liquid covering material. Thus, the hydrogen produced by the reaction of the sodium and the aqueous alkaline solution will float up, pass through the liquid covering material and be discharged. The sodium will pass through the gauze and float upwardly while reacting with the aqueous alkaline solution in a partic ulate state to the boundary between the aqueous alkaline solution and up to the covering material, and thus the theratment reaction will continue. Thus, the cover material prevents the sodium and the aqueous alkaline solution from scattering. (Kamimura, M.)

  16. Application conditions for ester cured alkaline phenolic resin sand

    Directory of Open Access Journals (Sweden)

    Ren-he Huang

    2016-07-01

    Full Text Available Five organic esters with different curing speeds: propylene carbonate (i.e. high-speed ester A; 1, 4-butyrolactone; glycerol triacetate (i.e. medium-speed ester B; glycerol diacetate; dibasic ester (DBE (i.e. low-speed ester C, were chosen to react with alkaline phenolic resin to analyze the application conditions of ester cured alkaline phenolic resin. The relationships between the curing performances of the resin (including pH value, gel pH value, gel time of resin solution, heat release rate of the curing reaction and tensile strength of the resin sand and the amount of added organic ester and curing temperature were investigated. The results indicated the following: (1 The optimal added amount of organic ester should be 25wt.%-30wt.% of alkaline phenolic resin and it must be above 20wt.%-50 wt.% of the organic ester hydrolysis amount. (2 High-speed ester A (propylene carbonate has a higher curing speed than 1, 4-butyrolactone, and they were both used as high-speed esters. Glycerol diacetate is not a high-speed ester in alkaline phenolic resin although it was used as a high-speed ester in ester cured sodium silicate sand; glycerol diacetate and glycerol triacetate can be used as medium-speed esters in alkaline phenolic resin. (3 High-speed ester A, medium-speed ester B (glycerol triacetate and low-speed ester C (dibasic ester, i.e., DBE should be used below 15 ìC, 35 ìC and 50 ìC, respectively. High-speed ester A or low-speed ester C should not be used alone but mixed with medium-speed ester B to improve the strength of the resin sand. (4 There should be a suitable solid content (generally 45wt.%-65wt.% of resin, alkali content (generally 10wt.%-15wt.% of resin and viscosity of alkaline phenolic resin (generally 50-300 mPa≤s in the preparation of alkaline phenolic resin. Finally, the technique conditions of alkaline phenolic resin preparation and the application principles of organic ester were discussed.

  17. Characterization of Human Bone Alkaline Phosphatase in Pichia Pastoris

    Science.gov (United States)

    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.

  18. Oxidation of propionic acid-3-14C with alkaline permanganate

    International Nuclear Information System (INIS)

    Zielinski, M.

    1981-01-01

    The mechanism of oxidation of propionic acid with permanganate in alkaline medium was reinvestigated using methyl- 14 C labelled propionate. The preferential rupture of the αC-βC bond in propionate in highly concentrated alkaline solutions of NaOH (and KOH) was confirmed and the appearance of 14 C-labelled oxalate explained by the formation of the symmetrical intermediate which decomposes in two different modes. (author)

  19. Sample preparation in alkaline media

    International Nuclear Information System (INIS)

    Nobrega, Joaquim A.; Santos, Mirian C.; Sousa, Rafael A. de; Cadore, Solange; Barnes, Ramon M.; Tatro, Mark

    2006-01-01

    The use of tetramethylammonium hydroxide, tertiary amines and strongly alkaline reagents for sample treatment involving extraction and digestion procedures is discussed in this review. The preparation of slurries is also discussed. Based on literature data, alkaline media offer a good alternative for sample preparation involving an appreciable group of analytes in different types of samples. These reagents are also successfully employed in tailored speciation procedures wherein there is a critical dependence on maintenance of chemical forms. The effects of these reagents on measurements performed using spectroanalytical techniques are discussed. Several undesirable effects on transport and atomization processes necessitate use of the method of standard additions to obtain accurate results. It is also evident that alkaline media can improve the performance of techniques such as inductively coupled plasma mass spectrometry and accessories, such as autosamplers coupled to graphite furnace atomic absorption spectrometers

  20. PURIFICATION AND CHARACTERISATION OF ALKALINE ...

    African Journals Online (AJOL)

    Prof. Adipala Ekwamu

    There was no clear decrease in the yield seen in the bands and the loss of enzyme was not observed with the gel analysis. It may ... The native gel results show clear distinct bands for the 3 alkaline phosphotase isoenzymes ..... British Medical.

  1. Alkaline resistant ceramics; Alkalimotstaandskraftiga keramer

    Energy Technology Data Exchange (ETDEWEB)

    Westberg, Stig-Bjoern [Vattenfall Utveckling AB, Aelvkarleby (Sweden)

    2001-02-01

    Despite durability in several environments, ceramics and refractories can not endure alkaline environments at high temperature. An example of such an environment is when burning biofuel in modern heat and power plants in which the demand for increasing efficiency results in higher combustion temperatures and content of alkaline substances in the flue gas. Some experiences of these environments has been gained from such vastly different equipment as regenerator chambers in the glass industry and MHD-generators. The grains of a ceramic material are usually bonded together by a glassy phase which despite it frequently being a minor constituent render the materials properties and limits its use at elevated temperature. The damage is usually caused by alkaline containing low-melting phases and the decrease of the viscosity of the bonding glass phase which is caused by the alkaline. The surfaces which are exposed to the flue gas in a modern power plant are not only exposed to the high temperature but also a corroding and eroding, particle containing, gas flow of high velocity. The use of conventional refractory products is limited to 1300-1350 deg C. Higher strength and fracture toughness as well as durability against gases, slag and melts at temperatures exceeding 1700 deg C are expected of the materials of the future. Continuous transport of corrosive compounds to the surface and corrosion products from the surface as well as a suitable environment for the corrosion to occur in are prerequisites for extensive corrosion to come about. The highest corrosion rate is therefore found in a temperature interval between the dew point and the melting point of the alkaline-constituent containing compound. It is therefore important that the corrosion resistance is sufficient in the environment in which alkaline containing melts or slag may appear. In environments such as these, even under normal circumstances durable ceramics, such as alumina and silicon carbide, are attacked

  2. Optical properties of alkaline earth borate glasses

    African Journals Online (AJOL)

    user

    ... devices; radiation shields, surgical lasers and their glass ceramic counter ... Alkaline earth oxides improve glass forming capability while heavy metal ... reports on optical properties of MO-B2O3 glasses containing alkaline earth oxides.

  3. Qualitative Carbohydrate Analysis using Alkaline Potassium ...

    Indian Academy of Sciences (India)

    IAS Admin

    CLASSROOM. 285. RESONANCE | March 2016. Qualitative Carbohydrate Analysis using Alkaline. Potassium Ferricyanide. Keywords. Alkaline potassium ferricyanide, qualitative ... Carbohydrates form a distinct class of organic compounds often .... Laboratory Techniques: A contemporary Approach, W B Saunders Com-.

  4. Measurement and calculation of dynamic coefficients in hydrodynamic bearings of gas films; Medicion y calculo de coeficientes dinamicos en cojinetes hidrodinamicos de peliculas de gas

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz, Rafael O.; Di Liscia, Marcelo H.; Diaz, Sergio E. [Universidad Simon Bolivar, Sartendejas, Baruta (Venezuela)

    2007-11-15

    dynamic coefficients. [Spanish] La identificacion de los coeficientes dinamicos en cojinetes de aire es fundamental para un adecuado analisis rotodinamico. El presente trabajo muestra el desarrollo de un algoritmo que permite la obtencion directa de los coeficientes dinamicos en cojinetes hidrodinamicos de aire tanto de forma numerica como experimental. El banco de pruebas utilizado consta de dos cojinetes magneticos, los cuales soportan al rotor en sus extremos y a su vez funcionan como actuadores permitiendo inducir orbitas controladas en el rotor. El cojinete de prueba se encuentra ubicado entre los cojinetes magneticos. Las fuerzas dinamicas generadas en el cojinete de aire se registran a partir de tres celdas de carga. El algoritmo fue desarrollado en un codigo comercial de programacion grafica, a traves del cual se pueden colectar, controlar y procesar las senales. El comportamiento no lineal de este tipo de cojinetes dificulta el calculo de los coeficientes dinamicos, por esta razon el procesamiento de las senales en espacio frecuencial facilita de cierta manera su manejo. Por otra parte, el modelo numerico se comparo con los resultados experimentales obteniendo aproximaciones aceptables tanto en magnitud como en comportamiento. El calculo de los coeficientes dinamicos numericos se realizo resolviendo la ecuacion diferencial de Reynolds para un fluido compresible en el espesor de la pelicula de gas, tomando en consideracion el flujo masico del fluido que se introduce, asi como la perdida de presion que sufre el mismo al pasar a traves de los orificios de alimentacion. Los metodos numericos utilizados incluyen la resolucion de la ecuacion diferencial de Reynolds por diferencias finitas, el calculo del perfil de presiones realizando iteraciones sucesivas y el calculo de las fuerzas hidrodinamicas a traves de una integracion numerica de Simpson. Los coeficientes dinamicos numericos fueron hallados aplicando una tecnica de minimos cuadrados a las fuerzas hidrodinamicas

  5. Development of alkaline fuel cells.

    Energy Technology Data Exchange (ETDEWEB)

    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. Influence of Oil Viscosity on Alkaline Flooding for Enhanced Heavy Oil Recovery

    Directory of Open Access Journals (Sweden)

    Yong Du

    2013-01-01

    Full Text Available Oil viscosity was studied as an important factor for alkaline flooding based on the mechanism of “water drops” flow. Alkaline flooding for two oil samples with different viscosities but similar acid numbers was compared. Besides, series flooding tests for the same oil sample were conducted at different temperatures and permeabilities. The results of flooding tests indicated that a high tertiary oil recovery could be achieved only in the low-permeability (approximately 500 mD sandpacks for the low-viscosity heavy oil (Zhuangxi, 390 mPa·s; however, the high-viscosity heavy oil (Chenzhuang, 3450 mPa·s performed well in both the low- and medium-permeability (approximately 1000 mD sandpacks. In addition, the results of flooding tests for the same oil at different temperatures also indicated that the oil viscosity put a similar effect on alkaline flooding. Therefore, oil with a high-viscosity is favorable for alkaline flooding. The microscopic flooding test indicated that the water drops produced during alkaline flooding for oils with different viscosities differed significantly in their sizes, which might influence the flow behaviors and therefore the sweep efficiencies of alkaline fluids. This study provides an evidence for the feasibility of the development of high-viscosity heavy oil using alkaline flooding.

  7. Influence of salivary enzymes and alkaline pH environment on fatigue behavior of resin composites

    NARCIS (Netherlands)

    Mirmohammadi, H.; Kleverlaan, C.J.; Aboushelib, M.N.; Feilzer, A.J.

    2011-01-01

    Purpose: To evaluate the effect of enzymatic activity and alkaline medium on flexural strength and rotary fatigue resistance of direct and indirect resin composite restorative materials. Methods: Three direct resin composite materials Filtek Z100, Filtek Z250 and Filtek Silorane (3M ESPE), and two

  8. Engineering of quorum-sensing systems for improved production of alkaline protease by Bacillus subtilis.

    NARCIS (Netherlands)

    Tjalsma, H.; Koetje, E.J.; Kiewiet, R.; Kuipers, O.P.; Kolkman, M.J.M.; Laan, J.H. van der; Daskin, R.; Ferrari, E.; Bron, S.

    2004-01-01

    AIM: Engineering of Rap-Phr quorum-sensing systems of Bacillus subtilis and subsequent evaluation of the transcription of the aprE gene, encoding a major extracellular alkaline protease. METHODS AND RESULTS: Addition of synthetic Phr pentapeptides to the growth medium, or overproduction of pre-Phr

  9. Engineering of quorum-sensing systems for improved production of alkaline protease by Bacillus subtilis

    NARCIS (Netherlands)

    Tjalsma, H; Koetje, EJ; Kiewiet, R; Kuipers, OP; Kolkman, M; van der Laan, J; Daskin, R; Ferrari, E; Bron, S

    2004-01-01

    Aim: Engineering of Rap-Phr quorum-sensing systems of Bacillus subtilis and subsequent evaluation of the transcription of the aprE gene, encoding a major extracellular alkaline protease. Methods and Results: Addition of synthetic Phr pentapeptides to the growth medium, or overproduction of pre-Phr

  10. Progress of research on the influence of alkaline cation and alkaline solution on bentonite properties

    International Nuclear Information System (INIS)

    Ye Weimin; Zheng Zhenji; Chen Bao; Chen Yonggui

    2011-01-01

    Based on the previous laboratory studies and numerical simulation on bentonite in alkaline environments, the effects of alkaline cation and alkaline solution on mineral composition, microstructure, swelling capacity and hydraulic properties of bentonite are emphasized in this paper, temperature, pH values and concentration are discussed as main affecting factors. When bentonite is exposed to alkaline cation or alkaline solution, microstructure of bentonite will be changed due to the dissolution of montmorillonite and the formation of secondary minerals, which results in the decrease of swelling pressure. The amount of the reduction of swelling pressure depends on the concentration of alkaline solution. Temperature, polyvalent cation, salinity and concentration are the main factors affecting hydraulic properties of bentonite under alkaline conditions. Therefore, future research should focus on the mechanism of coupling effects of weak alkaline solutions on the mineral composition, microstructure, swelling capacity and hydraulic properties of bentonite under different temperatures and different pH values. (authors)

  11. Ozonização em meio básico para redução de cor do licor negro de indústria de celulose de algodão Color reduction of black liquor from cotton cellulose industry using ozonation in an alkaline medium

    Directory of Open Access Journals (Sweden)

    José Roberto Guimarães

    2010-03-01

    Full Text Available As indústrias de papel e celulose descartam no ambiente um grande volume de efluente contendo grande quantidade da substância lignina, que atribui coloração e apresenta considerável potencial de toxicidade. Neste trabalho, foi avaliada a ozonização em meio básico para a redução de cor do licor negro gerado por uma indústria de celulose de algodão. Face aos resultados, foi possível observar que, para menores concentrações iniciais de ozônio (0,4 gO3 L-1 h-1, foi necessário um tempo mais longo de ozonização para se obter a redução desejada de 80% da cor. O consumo específico de ozônio, entretanto, em comparação a experimentos com dosagens mais elevadas (4,3 gO3 L-1 h-1 foi menor. Sugere-se que o oxigênio molecular desempenhe, também, um importante papel na oxidação dos compostos, participando do mecanismo de oxidação iniciado por radical hidroxila, •OH, formado na ozonização em meio básico.Pulp and paper mills discharge large amounts of wastewater containing high concentrations of lignin, a coloring substance that is dangerous and presents high toxicity to the environment. In this study, ozonation in alkaline ambience was evaluated for color reduction in black liquor, generated in a cotton linter mill. It was observed that the ozonation time to reach 80% color reduction was higher at a lower initial ozone dose (0,4 gO3 L-1 h-1 in comparison to a higher initial ozone dose (4,3 gO3 L-1 h-1. On the other hand, the amount of consumed oxidant was lower at the lower ozone dose. It is suggested that molecular oxygen participates in the oxidation mechanism of colored compounds, which is initiated by hydroxyl radicals (•OH formed during ozonation in alkaline ambience.

  12. Kinetics Study of Extracellular Detergent Stable Alkaline Protease from Rhizopus oryzae

    Directory of Open Access Journals (Sweden)

    Zareena Mushtaq

    2015-04-01

    Full Text Available In this study, extracellular alkaline protease was produced from Rhizopus oryzae in submerged fermentation using dairy waste (whey as a substrate. Fermentation kinetics was studied and various parameters were optimized. The strain produced maximum protease at initial medium pH of 6.0 medium depth of 26 mm, inoculum size of 2% at incubation temperature of 35ºC for 168 h of fermentation. Alkaline protease was purified to homogeneity by ammonium sulphate fractionation followed by sephadex G-100 chromatography. The molecular mass of alkaline protease was 69 kDa determined by 10% SDS-PAGE. The optimum pH and temperature of alkaline protease was 9.0 and 40ºC, respectively. Metal profile of the enzyme showed that the enzyme was non-metallic in nature. The Km , Kcat , Vmax and Kcat/Km values of purified protease were 7.0 mg/mL, 3.8 x102S-1, 54.30 µmol/min and 54.28 s-1mg -1.mL respectively, using casein as substrate. The purified alkaline protease had stability with commercial detergents.

  13. Colorimetric study of oxidation kinetics of thiolactic acid (2 - mercaptopropionic acid) by hexacyanoferrate (III) in acid and alkaline media

    International Nuclear Information System (INIS)

    Kachhwaha, O.P.; Potter, P.C.; Kapoor, R.C.

    1985-01-01

    The oxidation kinetics of thiolactic acid by hexacyanoferrate (III) in acid and alkaline media employing the calorimetric method have been described. The two compounds react in equimolar ratio in both media, but the kinetic results are different in both media. In acid medium the total order is three, two with respect to thiol and one in oxidant. The rate of the reaction shows an inverse proportionality to (H + ) and also varies inversely with decreasing dielectric constant of the medium. In alkaline medium, the total order of the reaction is two, being unity in each reactant. The rate increases with increased pH value. Additions of ferrocyanide and dithio dilactic acid have no effect on the rate in both media. Additions of a neutral electrolyte does not affect the rate in the acid medium, while a positive salt effect was observed in an alkaline medium. Activation parameters have been evaluated in both media and in a medium of low dialectric. Different reaction schemes have been proposed for acid and alkaline media and have satisfactory explained the experimental data, except for the pH rate. (author)

  14. Electrochemical oxidation of ethanol using PtRh/C electrocatalysts in alkaline medium and synthesized by sodium borohydride and alcohol reduction; Oxidação eletroquímica do etanol utilizando eletrocatalisadores PtRh/C em meio alcalino e sintetizados via borohidreto de sódio e redução por álcool

    Energy Technology Data Exchange (ETDEWEB)

    Fontes, Eric Hossein

    2017-07-01

    PtRh/C were prepared by the following atomic proportions: (100,0), (0,100), (90,10), (70,30) and (50,50). The methods employed in the synthesis of these materials were reduction by sodium borohydride and reduction by alcohol. The metal salts used were H{sub 2}PtCl{sub 6}3•6H{sub 2}0 and (RhNO{sub 3}){sub 3}, the support used was Carbon black XC72 and the bulk metal composition was 20% and 80% of support. The electrocatalysts were characterized by Energy Dispersive X-ray spectroscopy, X-ray diffraction and Transmission electron microscopy. The ethanol electrochemical oxidation mechanism was investigated by in situ Fourier Transform Infrared Spectroscopy couple to an Attenuated Total Reflection technique. The electrocatalytic activity were evaluated by Cyclic Voltammetry, Linear Sweep Voltammetry and Chronoamperometry techniques. The Fuel Cells tests were made in a single direct alcohol fuel cell with alkaline membrane. The working electrodes were prepared by a thin porous coating technique. X-ray diffraction allowed to verify metallic alloys, segregate phases and to calculate the percentage of metallic alloys. It was else possible to identify crystallographic phases. Infrared Spectroscopy allowed to verify that the electrochemical oxidation of ethanol was carried out by an incomplete mechanism. PtRh(70:30)/C prepared by sodium borohydride produced large amounts of carbon dioxide and acetaldehyde. Rh/C showed electrocatalytic activity when compared with other materials studied.

  15. Increased liver alkaline phosphatase and aminotransferase ...

    African Journals Online (AJOL)

    The effect of daily, oral administration of ethanolic extract of Khaya senegalensis stem bark (2mg/kg body weight) for 18days on the alkaline phosphatase, aspartate and alanine aminotransferase activities of rat liver and serum were investigated. Compared with the control, the activities of liver alkaline phosphatase (ALP), ...

  16. Alkaline pH sensor molecules.

    Science.gov (United States)

    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. © 2015 Wiley Periodicals, Inc.

  17. TiO{sub 2} obtained by laser ablation and it response in alkaline medium for the oxygen detachment reaction; TiO{sub 2} obtenido por ablacion laser y su respuesta en medio alcalino para la reaccion de desprendimiento de oxigeno

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez B, J.; Escobar A, L.; Fernandez V, S.M. [ININ, 52750 La Marquesa, Ocoyoacac (Mexico)]. e-mail: jjb@nuclear.inin.mx

    2007-07-01

    The performance of the photo electrocatalysts materials depends on one hand of the it structures of the crystalline lattice and of their surface properties, those which in turn are determined by the material preparation method. In this work the laser ablation technique to obtain thin films of titanium dioxide on recovered glass with tin oxide is presented. The carried out analyses showed homogeneous films, one of amorphous titanium oxide with a band width of 3.43 eV and the other one with anatase structure with a band energy of 3.41 eV. The photoresponse for the oxygen detachment it was better for the anatase. In a 0.1M KOH medium it was found corrosion in the films. (Author)

  18. In Situ Infrared Spectroscopy of Oligoaniline Intermediates Created under Alkaline Conditions.

    Science.gov (United States)

    Šeděnková, Ivana; Stejskal, Jaroslav; Trchová, Miroslava

    2014-12-26

    The progress of the oxidation of aniline with ammonium peroxydisulfate in an alkaline aqueous medium has been monitored in situ by attenuated total reflection (ATR) Fourier transform infrared spectroscopy. The growth of the microspheres and of the film at the ATR crystal surface, as well as the changes proceeding in the surrounding aqueous medium, are reflected in the spectra. The evolution of the spectra and the changes in the molecular structure occurring during aniline oxidation in alkaline medium are discussed with the help of differential spectra. Several processes connected with the various stages of aniline oxidation were distinguished. The progress of hydrolysis of the aniline in water and further an oxidation of aminophenol to benzoquinone imines in the presence of peroxydisulfate in alkaline medium have been detected in the spectra in real time. The precipitated solid oxidation product was analyzed by mass spectrometry. It is composed of oligomers, mainly trimers to octamers, of various molecular structures incorporating in addition to aniline constitutional units also p-benzoquinone or p-benzoquinoneimine moieties.

  19. Alkaline pretreatment of Mexican pine residues for bioethanol ...

    African Journals Online (AJOL)

    Alkaline pretreatment of Mexican pine residues for bioethanol production. ... Keywords: Lignocellulosic biomass, alkaline pretreatment, enzymatic hydrolysis, fermentable sugars, fermentation. African Journal of Biotechnology Vol. 12(31), pp.

  20. Alkaline sorbent injection for mercury control

    Science.gov (United States)

    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.

  1. Alkaline rocks and the occurrence of uranium

    International Nuclear Information System (INIS)

    Hambleton-Jones, B.B.; Toens, P.D.

    1980-10-01

    Many alkaline complexes contain uranium and other minerals in low concentrations and are regarded as constituting valuable potential reserves. Certain complex metallurgical problems, however, remain to be solved. Alkaline rocks occur in a number of forms and environments and it is noted that they are generated during periods of geological quiescence emplaced mainly in stable aseismic areas. Many occur along the extensions of oceanic transform faults beneath the continental crust and the application of this concept to areas not currently known to host alkaline complexes may prove useful in identifying potential target areas for prospecting operations [af

  2. Alkalinity in oil field waters - what alkalinity is and how it is measured

    International Nuclear Information System (INIS)

    Kaasa, B.; Oestvold, T.

    1996-01-01

    The alkalinity is an important parameter in the description of pH-behaviour, buffer capacity and scaling potentials in oil field waters. Although the alkalinity is widely used, it seems to be considerable confusion in connection with the concept. It is often used incorrectly and different authors define the concept in different ways. Several different methods for the determination of alkalinity can be found in the literature. This paper discusses the definition of alkalinity and how to use alkalinity in oil field waters to obtain data of importance for scale and pH predictions. There is also shown how a simple titration of oil field waters can give both the alkalinity and the content of organic acids in these waters. It is obvious from these findings that most of the methods used to day may give considerable errors when applied to oil field waters with high contents of organic acids. 8 refs., 8 figs., 5 tabs

  3. Optical properties of alkaline earth borate glasses

    African Journals Online (AJOL)

    user

    The alkaline earth borate glasses containing heavy metal oxides show good solubility of rare-earth ions. Glasses containing PbO exhibit low glass transition temperature (Tg) and high ..... These oxygen ions carry a partial negative charge and.

  4. Technetium recovery from high alkaline solution

    Energy Technology Data Exchange (ETDEWEB)

    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.

  5. Zinc, copper and manganese availability in soils treated with alkaline sewage sludge from Paraná state (Brazil

    Directory of Open Access Journals (Sweden)

    Maristela Dalpisol

    Full Text Available ABSTRACT In Paraná, most of the sludge generated in sewage treatment plants is subjected to the prolonged alkaline stabilization process. Although it is known that the alkaline sewage sludge contains micronutrients such as Zn, Cu and Mn, little is known about the availability of these elements in soils treated with this type of sewage sludge. Thus, the objective of the study was to evaluate the influence of alkaline sewage sludge from Paraná on Zn, Cu and Mn availability in soils. Twenty sewage treatment plants were selected throughout Paraná, where alkaline sewage sludge and the most representative agricultural soil of the each region were collected. Each soil was incubated for 60 days with alkaline sewage sludge rates (0, 10, 20, 40, and 80 Mg ha-1 from their region. Subsequently, Zn, Cu and Mn availability was determined using the Mehlich-1 extractant. The alkaline sewage sludge increased Zn availability and decreased Mn availability in most soils. Cu showed intermediate results, with increased availability, primarily in medium texture soils and decrease in most of the clayey soils. In soils with pH close to ideal for the plant growth, the alkaline sewage sludge rate should be carefully calculated so that there is no excessive increase in the pH and Zn, Cu and Mn imbalance.

  6. Effect of clay content in rock on oil extraction under alkaline seam conditions

    Energy Technology Data Exchange (ETDEWEB)

    Vezirov, D Sh; Gorbunov, A T; Kasimov, Sh A; Kashchavtsev, V E; Tairov, N D

    1978-01-01

    When oil beds are flooded with alkaline solutions, the alkaline concentration in the solution can be significantly reduced as a result of the interaction between clay and alkali. Large losses of alkali in the bed can render the flooding method ineffective. Experimental studies were conducted on porous media containing up to 25% clay at a constant permeability of 1 D in order to determine the oil extraction indices for clay-containing rock. Constant permeability is maintained by using clays, marshalite, and quartz sand in various proportions. Oil having a viscosity of 99.17 sP, and containing a large amount of surfactants, including 1.1% naphthenic acid, was extracted by fresh water and a 0.25% solution of NaOH. The extraction of oil by fresh water and NaOH solution from quartz sand indicated the advantage of using alkaline solutions. The extraction coefficient increased by 11% with the use of this method. As clay is added to the sand, the extraction coefficient decreases, and is reduced to 12.7% when the clay content reaches 25%. Nevertheless, a comparison of data obtained for quartz sand with fresh water on a porous medium containing 25% clay with an alkaline solution, indicates that the extraction coefficient is just 1.5% lower even in the presence of such a large amount of clay. Consequently, alkaline flooding should still be given preference over the usual methods under specific conditions and where the rock has a comparatively large amount of clay, in view of all the basic factors that influence the extraction process. The results obtained can be used for selecting alkaline concentration in evaluating the efficiency of flooding oil beds with alkaline solutions. 2 figures, 2 tables.

  7. Effect of pH on the production of alkaline proteinase by alkalophilic Bacillus sp

    International Nuclear Information System (INIS)

    Kitada, Makio; Horikoshi, Koki

    1976-01-01

    The effect of the pH of the medium on the microbial growth and alkaline proteinase production, and on the uptake of various substances by alkalophilic Bacillus sp. No.8-1 were studied to investigate the physiological properties of alkalophilic bacteria. Both the microbial growth and alkaline proteinase production by replacement culture were maximum between pH 9 and 10. The alkaline proteinase production sources were also effective for the production. The uptake of various substances such as glucose, acetate, amino acids, and uracil, necessary for proteinase production by this strain, was maximum between pH 9 and 10. The uptake of α-aminoisobutyric acid, a nonmetabolizable amino acid analogue, was also maximum at pH 10. The pH-dependence of these substance was not due to their ionic forms being affected by extracellular pH. It was concluded from above results that good production of alkaline proteinase in alkaline media was due to the active uptake of various nutrients in this culture condition. (auth.)

  8. Improved electrodes and gas impurity investigations on alkaline electrolysers

    DEFF Research Database (Denmark)

    Reissner, R.; Schiller, G.; Knoeri, T.

    Alkaline water electrolysis for hydrogenproduction is a well-established techniquebut some technological issues regarding thecoupling of alkaline water electrolysis andRenewable Energy Sources (RES) remain tobe improved.......Alkaline water electrolysis for hydrogenproduction is a well-established techniquebut some technological issues regarding thecoupling of alkaline water electrolysis andRenewable Energy Sources (RES) remain tobe improved....

  9. Carbon supported Pd-Ni and Pd-Ru-Ni nanocatalysts for the alkaline direct ethanol fuel cell (DEFC)

    CSIR Research Space (South Africa)

    Mathe, MK

    2011-08-01

    Full Text Available Carbon supported Pd-Ni and Pd-Ru-Ni nanocatalysts were prepared by the chemical reduction method, using sodium borohydride and ethylene glycol mixture as the reducing agent. The catalytic activity towards ethanol electro-oxidation in alkaline medium...

  10. On performance capabilities of alkaline anolyte in wastewater management

    International Nuclear Information System (INIS)

    Shimkevich, Alexander

    2014-01-01

    A concept for electric converting a saline wastewater into basic solution (pH > 7) with a positive RedOx potential (alkaline anolyte) is considered. Such the medium can be obtained in situ at flowing wastewater via a special electrochemical cell with strongly polarized cathode (generating hydroxide anions) and quasi-equilibrium anode which intensively discharges hydroxide ions to hydroxyl radicals into the wastewater. The radicals will oxidize anions of strong acid and convert them into weak-acid micro precipitates in the flowing basic solution. These renewable nano-sorbents will uninterruptedly co-precipitate radioactive contamination from wastewater and be agglomerated as corrosion by-products in the felt-like anode. The consideration of liquid water as a chemical compound with a wide band gap shows that the anolyte (as a hyper-stoichiometric water, H 2 O 1+|x| ) is a simple and effective tool for varying physical and chemical properties of the aqueous solution due to forced changing its RedOx potential as one needs. This potential as Fermi level in the band gap of liquid water is the most convenient parameter for monitoring and managing the electrochemical potential of the aqueous medium. Its hyper-stoichiometric state is realized when Fermi level is shifted to the top of a valence band. This electro-oxidized state as the alkaline anolyte is characterized by an acceptor level, OH/OH - , partially occupied by electrons. Then, the hydroxyl radical (OH • ) as the strongest oxidizer will oxidize intensively the metal anode and renew its surface for great removal of radio-nuclides from the wastewater due to their large specific area of renewable surface of hydroxide absorber on the felt-like anode. (author)

  11. Usefulness of organic acid produced by Exiguobacterium sp. 12/1 on neutralization of alkaline wastewater.

    Science.gov (United States)

    Kulshreshtha, Niha Mohan; Kumar, Anil; Bisht, Gopal; Pasha, Santosh; Kumar, Rita

    2012-01-01

    The aim of this study was to investigate the role of organic acids produced by Exiguobacterium sp. strain 12/1 (DSM 21148) in neutralization of alkaline wastewater emanated from beverage industry. This bacterium is known to be able to grow in medium of pH as high as pH 12.0 and to neutralize alkaline industrial wastewater from pH 12.0 to pH 7.5. The initial investigation on the type of functional groups present in medium, carried out using FT-IR spectroscopy, revealed the presence of peaks corresponding to carbonyl group and hydroxyl group, suggesting the release of carboxylic acid or related metabolic product(s). The identification of specific carboxylic group, carried out using RP-HPLC, revealed the presence of a single peak in the culture supernatant with retention time most similar to formic acid. The concentration of acid produced on different carbon sources was studied as a function of time. Although acid was present in same final concentration, the rate of acid production was highest in case of medium supplemented with sucrose followed by fructose and glucose. The knowledge of metabolic products of the bacterium can be considered as a first step towards realization of its potential for large-scale bioremediation of alkaline wastewater from beverage industry.

  12. Usefulness of Organic Acid Produced by Exiguobacterium sp. 12/1 on Neutralization of Alkaline Wastewater

    Directory of Open Access Journals (Sweden)

    Niha Mohan Kulshreshtha

    2012-01-01

    Full Text Available The aim of this study was to investigate the role of organic acids produced by Exiguobacterium sp. strain 12/1 (DSM 21148 in neutralization of alkaline wastewater emanated from beverage industry. This bacterium is known to be able to grow in medium of pH as high as pH 12.0 and to neutralize alkaline industrial wastewater from pH 12.0 to pH 7.5. The initial investigation on the type of functional groups present in medium, carried out using FT-IR spectroscopy, revealed the presence of peaks corresponding to carbonyl group and hydroxyl group, suggesting the release of carboxylic acid or related metabolic product(s. The identification of specific carboxylic group, carried out using RP-HPLC, revealed the presence of a single peak in the culture supernatant with retention time most similar to formic acid. The concentration of acid produced on different carbon sources was studied as a function of time. Although acid was present in same final concentration, the rate of acid production was highest in case of medium supplemented with sucrose followed by fructose and glucose. The knowledge of metabolic products of the bacterium can be considered as a first step towards realization of its potential for large-scale bioremediation of alkaline wastewater from beverage industry.

  13. Assessing ocean alkalinity for carbon sequestration

    Science.gov (United States)

    Renforth, Phil; Henderson, Gideon

    2017-09-01

    Over the coming century humanity may need to find reservoirs to store several trillions of tons of carbon dioxide (CO2) emitted from fossil fuel combustion, which would otherwise cause dangerous climate change if it were left in the atmosphere. Carbon storage in the ocean as bicarbonate ions (by increasing ocean alkalinity) has received very little attention. Yet recent work suggests sufficient capacity to sequester copious quantities of CO2. It may be possible to sequester hundreds of billions to trillions of tons of C without surpassing postindustrial average carbonate saturation states in the surface ocean. When globally distributed, the impact of elevated alkalinity is potentially small and may help ameliorate the effects of ocean acidification. However, the local impact around addition sites may be more acute but is specific to the mineral and technology. The alkalinity of the ocean increases naturally because of rock weathering in which >1.5 mol of carbon are removed from the atmosphere for every mole of magnesium or calcium dissolved from silicate minerals (e.g., wollastonite, olivine, and anorthite) and 0.5 mol for carbonate minerals (e.g., calcite and dolomite). These processes are responsible for naturally sequestering 0.5 billion tons of CO2 per year. Alkalinity is reduced in the ocean through carbonate mineral precipitation, which is almost exclusively formed from biological activity. Most of the previous work on the biological response to changes in carbonate chemistry have focused on acidifying conditions. More research is required to understand carbonate precipitation at elevated alkalinity to constrain the longevity of carbon storage. A range of technologies have been proposed to increase ocean alkalinity (accelerated weathering of limestone, enhanced weathering, electrochemical promoted weathering, and ocean liming), the cost of which may be comparable to alternative carbon sequestration proposals (e.g., $20-100 tCO2-1). There are still many

  14. Posttranslational heterogeneity of bone alkaline phosphatase in metabolic bone disease.

    Science.gov (United States)

    Langlois, M R; Delanghe, J R; Kaufman, J M; De Buyzere, M L; Van Hoecke, M J; Leroux-Roels, G G

    1994-09-01

    Bone alkaline phosphatase is a marker of osteoblast activity. In order to study the posttranscriptional modification (glycosylation) of bone alkaline phosphatase in bone disease, we investigated the relationship between mass and catalytic activity of bone alkaline phosphatase in patients with osteoporosis and hyperthyroidism. Serum bone alkaline phosphatase activity was measured after lectin precipitation using the Iso-ALP test kit. Mass concentration of bone alkaline phosphatase was determined with an immunoradiometric assay (Tandem-R Ostase). In general, serum bone alkaline phosphatase mass and activity concentration correlated well. The activity : mass ratio of bone alkaline phosphatase was low in hyperthyroidism. Activation energy of the reaction catalysed by bone alkaline phosphatase was high in osteoporosis and in hyperthyroidism. Experiments with neuraminidase digestion further demonstrated that the thermodynamic heterogeneity of bone alkaline phosphatase can be explained by a different glycosylation of the enzyme.

  15. High temperature and pressure alkaline electrolysis

    DEFF Research Database (Denmark)

    Allebrod, Frank; Chatzichristodoulou, Christodoulos; Mogensen, Mogens Bjerg

    2013-01-01

    Alkaline electrolyzers have proven to operate reliable for decades on a large scale, but in order to become commercially attractive and compete against conventional technologies for hydrogen production, the production and investment costs have to be reduced. This may occur by increasing the opera......Alkaline electrolyzers have proven to operate reliable for decades on a large scale, but in order to become commercially attractive and compete against conventional technologies for hydrogen production, the production and investment costs have to be reduced. This may occur by increasing...

  16. Catalytic oxidation of soot over alkaline niobates

    International Nuclear Information System (INIS)

    Pecchi, G.; Cabrera, B.; Buljan, A.; Delgado, E.J.; Gordon, A.L.; Jimenez, R.

    2013-01-01

    Highlights: ► No previous reported studies about alkaline niobates as catalysts for soot oxidation. ► NaNbO 3 and KNbO 3 perovskite-type oxides show lower activation energy than other lanthanoid perovskite-type oxides. ► The alkaline niobate does not show deactivation by metal loss. - Abstract: The lack of studies in the current literature about the assessment of alkaline niobates as catalysts for soot oxidation has motivated this research. In this study, the synthesis, characterization and assessment of alkaline metal niobates as catalysts for soot combustion are reported. The solids MNbO 3 (M = Li, Na, K, Rb) are synthesized by a citrate method, calcined at 450 °C, 550 °C, 650 °C, 750 °C, and characterized by AAS, N 2 adsorption, XRD, O 2 -TPD, FTIR and SEM. All the alkaline niobates show catalytic activity for soot combustion, and the activity depends basically on the nature of the alkaline metal and the calcination temperature. The highest catalytic activity, expressed as the temperature at which combustion of carbon black occurs at the maximum rate, is shown by KNbO 3 calcined at 650 °C. At this calcination temperature, the catalytic activity follows an order dependent on the atomic number, namely: KNbO 3 > NaNbO 3 > LiNbO 3 . The RbNbO 3 solid do not follow this trend presumably due to the perovskite structure was not reached. The highest catalytic activity shown by of KNbO 3 , despite the lower apparent activation energy of NaNbO 3 , stress the importance of the metal nature and suggests the hypothesis that K + ions are the active sites for soot combustion. It must be pointed out that alkaline niobate subjected to consecutive soot combustion cycles does not show deactivation by metal loss, due to the stabilization of the alkaline metal inside the perovskite structure.

  17. Alkaline earth filled nickel skutterudite antimonide thermoelectrics

    Science.gov (United States)

    Singh, David Joseph

    2013-07-16

    A thermoelectric material including a body centered cubic filled skutterudite having the formula A.sub.xFe.sub.yNi.sub.zSb.sub.12, where A is an alkaline earth element, x is no more than approximately 1.0, and the sum of y and z is approximately equal to 4.0. The alkaline earth element includes guest atoms selected from the group consisting of Be, Mb, Ca, Sr, Ba, Ra and combinations thereof. The filled skutterudite is shown to have properties suitable for a wide variety of thermoelectric applications.

  18. Mineralogical, petrological and geochemical aspects of alkaline and alkaline-carbonatite associations from Brazil

    Science.gov (United States)

    Morbidelli, L.; Gomes, C. B.; Beccaluva, L.; Brotzu, P.; Conte, A. M.; Ruberti, E.; Traversa, G.

    1995-12-01

    A general description of Mesozoic and Tertiary (Fortaleza) Brazilian alkaline and alkaline-carbonatite districts is presented with reference to mineralogy, petrology, geochemistry and geochronology. It mainly refers to scientific results obtained during the last decade by an Italo-Brazilian research team. Alkaline occurrences are distributed across Brazilian territory from the southern (Piratini, Rio Grande do Sul State) to the northeastern (Fortaleza, Ceará State) regions and are mainly concentrated along the borders of the Paraná Basin generally coinciding with important tectonic lineaments. The most noteworthy characteristics of these alkaline and alkaline-carbonatite suites are: (i) prevalence of intrusive forms; (ii) abundance of cumulate assemblages (minor dunites, frequent clinopyroxenites and members of the ijolite series) and (iii) abundance of evolved rock-types. Many data demonstrate that crystal fractionation was the main process responsible for magma evolution of all Brazilian alkaline rocks. A hypothesis is proposed for the genesis of carbonatite liquids by immiscibility processes. The incidence of REE and trace elements for different major groups of lithotypes, belonging both to carbonatite-bearing and carbonatite-free districts, are documented. Sr and preliminary Nd isotopic data are indicative of a mantle origin for the least evolved magmas of all the studied occurrences. Mantle source material and melting models for the generation of the Brazilian alkaline magma types are also discussed.

  19. Reactivities of some aldoses towards iodine in alkaline

    International Nuclear Information System (INIS)

    Azmat, R.; Nizami, S.S.

    2005-01-01

    The kinetics studies of oxidation of some reducing sugars by aqueous alkaline solution of iodine investigated. Results demonstrated that iodine in the presence of alkali converted into hypoiodous acid which was effective oxidizing species. Reaction between iodine and sugars was slowest reaction. The rate of oxidation of sugars was affected by change in pH of the medium and maximum at pH 11.4 where the concentration of hypoiodous acid was maximum which oxidized the sugars into respective acids. The rate of oxidation followed first order kinetics with respect to substrate and obeyed zero order kinetics with that of iodine. Change in ionic strength of the medium showed no effect on the rate of oxidation indicating that reaction occurred between molecular species and there was no ionic species present in the rate determining step. Reaction was affected by the change in temperature and value of energy of activation corresponding to glucose, galactose, D-mannose and L-arabinose were 10.16 kj/mol, 12.17 kj/mol, 14.00 kj/mol and 20.22 kj/mol respectively. (author)

  20. Determination of Acidity and Alkalinity of Food Materials

    OpenAIRE

    三浦,芳助; 福永,祐子; 瀧川,裕里子; 津田,真美; 渡辺,陽子; 瀨山,一正

    2006-01-01

    The acidity and alkalinity of food materials in various menus was determined to clarify the influence of food on physiological functions. Menus mainly containing alkaline food materials (alkaline menu) and acid ones (acid menu) were compared. Determination of acidity and alkalinity was performed for each food material in the alkaline menu and acid menu, and acidity and alkalinity of one meal and a day's one were estimated. 1. Most of food materials in acid menu were assessed to be...

  1. The Alkaline Diet: Is There Evidence That an Alkaline pH Diet Benefits Health?

    Directory of Open Access Journals (Sweden)

    Gerry K. Schwalfenberg

    2012-01-01

    Full Text Available This review looks at the role of an alkaline diet in health. Pubmed was searched looking for articles on pH, potential renal acid loads, bone health, muscle, growth hormone, back pain, vitamin D and chemotherapy. Many books written in the lay literature on the alkaline diet were also reviewed and evaluated in light of the published medical literature. There may be some value in considering an alkaline diet in reducing morbidity and mortality from chronic diseases and further studies are warranted in this area of medicine.

  2. The Alkaline Diet: Is There Evidence That an Alkaline ph Diet Benefits Health?

    International Nuclear Information System (INIS)

    Schwalfenberg, G.K.

    2012-01-01

    This review looks at the role of an alkaline diet in health. Pub med was searched looking for articles on ph, potential renal acid loads, bone health, muscle, growth hormone, back pain, vitamin D and chemotherapy. Many books written in the lay literature on the alkaline diet were also reviewed and evaluated in light of the published medical literature. There may be some value in considering an alkaline diet in reducing morbidity and mortality from chronic diseases and further studies are warranted in this area of medicine

  3. Concept medium programme

    DEFF Research Database (Denmark)

    Bjerrum, Peter

    2005-01-01

    The present essay is an attempt to determine the architectural project of the 21st century in relation to a modern conception of space as the medium of architecture, and of sociality as its program......The present essay is an attempt to determine the architectural project of the 21st century in relation to a modern conception of space as the medium of architecture, and of sociality as its program...

  4. Alkaline Activator Impact on the Geopolymer Binders

    Science.gov (United States)

    Błaszczyński, Tomasz Z.; Król, Maciej R.

    2017-10-01

    Concrete structures are constantly moving in the direction of improving the durability. Durability depends on many factors, which are the composition of concrete mix, the usage of additives and admixtures and the place, where material will work and carry the load. The introduction of new geopolymer binders for geopolymer structures adds a new aspect that is type of used activator. This substance with strongly alkaline reaction is divided because of the physical state, the alkaline degree and above all the chemical composition. Taking into account, that at present the geopolymer binders are made essentially from waste materials or by-products from the combustion of coal or iron ore smelting, unambiguous determination of the effect of the activator on the properties of the geopolymer material requires a number of trials, researches and observation. This paper shows the influence of the most alkaline activators on the basic parameters of the durability of geopolymer binders. In this study there were used highly alkaline hydroxides, water glasses and granules, which are waste materials in a variety of processes taking place in chemical plants. As the substrate of geopolymer binders there were used fly ash which came from coal and high calcareous ash from the burning of lignite.

  5. ENHANCED OIL RECOVERY USING LOCAL ALKALINE

    African Journals Online (AJOL)

    user

    the discovery of new oil producing fields and the ever increasing ... followed by water flooding is between 35 to 50% of the ... involved and lack of scale up and is considered among ... carbonate alkaline chemical reacts with certain types of ... reservoirs because of the profusion of calcium and the ... damage the formation.

  6. Electrochemical behaviour of alkaline copper complexes

    Indian Academy of Sciences (India)

    Abstract. A search for non-cyanide plating baths for copper resulted in the development of alkaline copper complex baths containing trisodium citrate [TSC] and triethanolamine [TEA]. Voltammetric studies were carried out on platinum to understand the electrochemical behaviour of these complexes. In TSC solutions, the.

  7. Alkaline fuel cell technology in the lead

    International Nuclear Information System (INIS)

    Nor, J.K.

    2004-01-01

    The Alkaline Fuel Cell (AFC) was the first fuel cell successfully put into practice, a century after William Grove patented his 'hydrogen battery' in 1839. The space program provided the necessary momentum, and alkaline fuel cells became the power source for both the U.S. and Russian manned space flight. Astris Energi's mission has been to bring this technology down to earth as inexpensive, rugged fuel cells for everyday applications. The early cells, LABCELL 50 and LABCELL 200 were aimed at deployment in research labs, colleges and universities. They served well in technology demonstration projects such as the 1998 Mini Jeep, 2001 Golf Car and a series of portable and stationary fuel cell generators. The present third generation POWERSTACK MC250 poised for commercialization is being offered to AFC system integrators as a building block of fuel cell systems in numerous portable, stationary and transportation applications. It is also used in Astris' own E7 and E8 alkaline fuel cell generators. Astris alkaline technology leads the way toward economical, plentiful fuel cells. The paper highlights the progress achieved at Astris, improvements of performance, durability and simplicity of use, as well as the current and future thrust in technology development and commercialization. (author)

  8. Biomass production on saline-alkaline soils

    Energy Technology Data Exchange (ETDEWEB)

    Chaturvedi, A.N.

    1985-01-01

    In a trial of twelve tree species (both nitrogen fixing and non-fixing) for fuel plantations on saline-alkaline soil derived from Gangetic alluvium silty clay, Leucaena leucocephala failed completely after showing rapid growth for six months. Results for other species at age two showed that Prosopis juliflora had the best productivity.

  9. Microbial communities associated with the anthropogenic, highly alkaline environment of a saline soda lime, Poland.

    Science.gov (United States)

    Kalwasińska, Agnieszka; Felföldi, Tamás; Szabó, Attila; Deja-Sikora, Edyta; Kosobucki, Przemysław; Walczak, Maciej

    2017-07-01

    Soda lime is a by-product of the Solvay soda process for the production of sodium carbonate from limestone and sodium chloride. Due to a high salt concentration and alkaline pH, the lime is considered as a potential habitat of haloalkaliphilic and haloalkalitolerant microbial communities. This artificial and unique environment is nutrient-poor and devoid of vegetation, due in part to semi-arid, saline and alkaline conditions. Samples taken from the surface layer of the lime and from the depth of 2 m (both having pH ~11 and EC e up to 423 dS m -1 ) were investigated using culture-based (culturing on alkaline medium) and culture-independent microbiological approaches (microscopic analyses and pyrosequencing). A surprisingly diverse bacterial community was discovered in this highly saline, alkaline and nutrient-poor environment, with the bacterial phyla Proteobacteria (representing 52.8% of the total bacterial community) and Firmicutes (16.6%) showing dominance. Compared to the surface layer, higher bacterial abundance and diversity values were detected in the deep zone, where more stable environmental conditions may occur. The surface layer was dominated by members of the genera Phenylobacterium, Chelativorans and Skermanella, while in the interior layer the genus Fictibacillus was dominant. The culturable aerobic, haloalkaliphilic bacteria strains isolated in this study belonged mostly to the genus Bacillus and were closely related to the species Bacillus pseudofirmus, B. cereus, B. plakortidis, B. thuringensis and B. pumilus.

  10. Enhanced production of alkaline protease by a mutant of Bacillus licheniformis N-2 for dehairing

    Directory of Open Access Journals (Sweden)

    Muhammad Nadeem

    2010-10-01

    Full Text Available The purpose of the present investigations was to improve the yield of alkaline protease for leather dehairing by subjecting the indigenous proteolytic strain Bacillus licheniformis N-2 to various mutagenic treatments viz. UV irradiations, NTG (N-methyl-N-nitro-N-nitrosoguinidine and MMS (methyl methane sulfonate. After screening on skim milk agar plates, a total of nine positive mutants were selected for shake flask experiments. Among these, the best proteolytic mutant designated as UV-9 showed 1.4 fold higher alkaline protease activity in preoptimized growth medium than the parent strain. The fermentation profile and kinetic parameters such u(h-1, Yp/s, Yp/x, Yx/s, q s, Qs, q p and Qp also indicated the superiority of the selected mutant UV-9 for alkaline protease production over the parent strain and rest of the mutants. The dehairing capability of mutant UV-9 alkaline protease was analyzed by soaking goat skin pieces for different time intervals (3-15 h at 40 º C. A complete dehairing without degradation of collagen was achieved after 12 h, indicating its commercial exploitation in leather industry.

  11. Alkaline-earth metal bicarbonates as lixiviants for uranium (VI) under CO2 sparging

    International Nuclear Information System (INIS)

    Vaziri, F.; White, D.A.

    1989-01-01

    In recent years it has become apparent that uranium is significantly soluble in solutions of alkaline-earth metal bicarbonates -particularly those of magnesium and calcium. A system has been proposed by previous authors in which milled uranium ore is leached in a medium to which an oxidizing agent, the metal hydroxide and CO 2 are added. The alkaline-earth metal hydroxides are much more readily soluble in this medium than the corresponding carbonates. Magnesium and calcium bicarbonates are quite soluble in aqueous media at neutral or nearly neutral pH. The pH determines the relative quantities of bicarbonate and carbonate ions in the system. Even if the pH is quite low, small amounts of carbonate ion are present that can complex with the uranyl ion to produce anionic uranyl complexes. Both UO 2 (CO 3 ) 2 2- and UO 2 (CO 3 ) 3 4- complexes are known and both have a very high stability constant. Despite the appearance of several patents on the use of alkaline-earth metal ions in carbonate media as uranium lixiviants, little theoretical or experimental work on the system has been published. In view of the potential of these systems for cheap, large-scale dissolution of uranium the present contribution will discuss the theory behind this method and provide some experimental data to verify the theoretical treatment. (author)

  12. Production of alkaline proteases by alkalophilic Bacillus subtilis ...

    African Journals Online (AJOL)

    Tuoyo Aghomotsegin

    2016-11-23

    Nov 23, 2016 ... Key words: Production, alkaline protease, Bacillus subtilis, animal wastes, enzyme activity. ... Generally, alkaline proteases are produced using submerged fermentation .... biopolymer concentrations were reported to have an influence ... adding nitrogenous compounds stimulate microorganism growth and ...

  13. Osteocalcin and bone-specific alkaline phosphatase in Sickle cell ...

    African Journals Online (AJOL)

    specific alkaline phosphatase (b-AP) total protein levels were evaluated as indicators of bone turnover in twenty patients with sickle cell haemoglobinopathies and in twenty normal healthy individuals. The serum bonespecific alkaline phosphatase ...

  14. Effect of carbonate in slightly alkaline medium on the corrosion of maraging steel

    International Nuclear Information System (INIS)

    Bellanger, G.

    1994-01-01

    This study was carried out to ascertain the behavior of maraging steel identified as AMS. 65-12 and used in the tanks of the French plant for the reprocessing of radioactive water. This water has a pH of 9 and contains carbonate ions. The rest or corrosion potentials can be in the transpassive or active region due to radiolytic species. Therefore, the behavior of maraging steel was studied in these two regions. In the neighborhood of the active-passive transition potentials, maraging steel is corroded by means of intermediates. The corrosion potential does not change with carbonate at a constant pH. With carbonate and a low scan rate, the breakdown transpassive potentials are displaced towards more positive potentials and the passive potential region is broader, while at a high scan rate these potentials are displaced towards more negative values. After the beginning of the reverse scan, the current is again positive. These suggest that the corrosion kinetics are not the same. The diffusion coefficient of species inside the oxide layer was determined. ((orig.))

  15. A comparative study of leaves extracts for corrosion inhibition effect on aluminium alloy in alkaline medium

    Directory of Open Access Journals (Sweden)

    Namrata Chaubey

    2017-12-01

    Full Text Available This paper deals with the comparative inhibition study of some plants leaves extract namely Cannabis sativa (CS, Rauwolfia serpentina (RS, Cymbopogon citratus (CC, Annona squamosa (AS and Adhatoda vasica (AV on the corrosion of aluminium alloy (AA in 1 M NaOH. The corrosion tests were performance by using gravimetric, electrochemical impedance spectroscopy (EIS, potentiodynamic polarization and linear polarization resistance (LPR techniques. RS showed maximum inhibition efficiency (η%, 97% at 0.2 g L−1. Potentiodynamic polarization curves justified that all the inhibitors are mixed-type. Surface morphology of AA is carried by scanning electron microscopy (SEM and atomic force microscopy (AFM.

  16. Characterization of Pt-Pd/C Electrocatalyst for Methanol Oxidation in Alkaline Medium

    Directory of Open Access Journals (Sweden)

    S. S. Mahapatra

    2011-01-01

    Full Text Available The Pt-Pd/C electrocatalyst was synthesized on graphite substrate by the electrochemical codeposition technique. The physicochemical characterization of the catalyst was done by SEM, XRD, and EDX. The electrochemical characterization of the Pt-Pd/C catalyst for methanol electro-oxidation was studied over a range of NaOH and methanol concentrations using cyclic voltammetry, quasisteady-state polarization, chronoamperometry, and electrochemical impedance spectroscopy. The activity of methanol oxidation increased with pH due to better OH species coverage on the electrode surface. At methanol concentration (>1.0 M, there is no change in the oxidation peak current density because of excess methanol at the electrode surface and/or depletion of OH− at the electrode surface. The Pt-Pd/C catalyst shows good stability and the low value of Tafel slope and charge transfer resistance. The enhanced electrocatalytic activity of the electrodes is ascribed to the synergistic effect of higher electrochemical surface area, preferred OH− adsorption, and ad-atom contribution on the alloyed surface.

  17. Mesoporous silica obtained with methyltriethoxysilane as co-precursor in alkaline medium

    Science.gov (United States)

    Putz, Ana-Maria; Wang, Kunzhou; Len, Adél; Plocek, Jiri; Bezdicka, Petr; Kopitsa, Gennady P.; Khamova, Tamara V.; Ianăşi, Cătălin; Săcărescu, Liviu; Mitróová, Zuzana; Savii, Cecilia; Yan, Minhao; Almásy, László

    2017-12-01

    Mesoporous silica particles have been synthesized by sol-gel method from tetraethoxysilane (tetraethylorthosilicate, TEOS) and methyltriethoxysilane (MTES), in ethanol and water mixture, at different ratios of the of the silica precursors. Ammonia was used as catalyst at room temperature and hexadecyltrimethylammonium bromide (cetyltrimethylammonium bromide, CTAB) as the structure directing agent. Nitrogen sorption, X-ray diffraction and small-angle neutron scattering gave information on the evolution of the gel structure and pore morphologies in the function of MTES/TEOS molar ratio. Thermogravimetric and differential thermal analysis showed that with addition of MTES the exothermic peak indicating the oxidation of the low molecular weight organic fragments shift to higher temperature. A room-temperature, one-pot synthesis of MCM-41 type materials is presented, in which the variation of the MTES concentration allows to change the hydrophobicity, preserving the specific properties materials, like the ordered pore structure, large specific surface area and high porosity. Specifically, the obtained materials had cylindrical pores, specific surface areas up to 1101 m2/g and total pore volumes up to 0.473 cm3/g. The obtained mesoporous materials are susceptible for further functionalization to improve their selective uptake of guest species in drug delivery applications.

  18. Action of copper (3) in periodate complex on hexavalent neptunium and plutonium in alkaline medium

    International Nuclear Information System (INIS)

    Shatokhina, O.B.; Alekseeva, D.P.; Peretrukhin, B.F.; Krot, N.N.

    1977-01-01

    A complex of trivalent copper connected with periodate has been studied in order to determine its possible use for oxidizing hexavalent transuranium elements. Proceeding from the dependence of formal potentials of the pairs Cusup((3))-Cusup((2)), Npsup((7))-Npsup((6)), Pusup((7))-Pusup((6)) on alkali concentration, it has been established that beginning with concentration 1M the potential of the pair Cusup((3))-Cusup((2)) is higher than that of the pair Npsup((7))-Npsup((6)) by approximately 50 mV. This means that a rather complete oxidation of hexavalent neptunium to heptavalent is possible by the action of copper (3) excess on neptunium (6) when KOH concentration is 1M and higher. Oxidation close to quantitative is attained in 1M KOH when excess of copper(3) is used and the ratio Npsup((6)): Cusup((3)) is 1:4 and higher. When KOH concentration is more than 1M a sufficiently complete oxidation (96-97%) of neptunium (6) is attained at Npsup((6)):Cusup((3))=1:2 or 1:3. Optimum conditions for oxidizing plutonium are 11M KOH and 2-3-fold excess of copper (3) reagent. At 9M KOH and a ratio Pusup((6)):Cusup((3))=1:2 the yield of Pu (7) is 33 %

  19. Mesoporous silica obtained with methyltriethoxysilane as co-precursor in alkaline medium

    Czech Academy of Sciences Publication Activity Database

    Putz, A.-M.; Wang, K.; Len, A.; Plocek, Jiří; Bezdička, Petr; Kopitsa, G. P.; Khamova, T. V.; Ianasi, C.; Sacarescu, L.; Mitróová, Z.; Savii, C.; Yan, M.; Almásy, L.

    2017-01-01

    Roč. 424, SI 3 (2017), s. 275-281 ISSN 0169-4332. [International Conference on Physics of Advanced Materials (ICPAM) /9./. Cluj Napoca, 08.09.2016-14.09.2016] Institutional support: RVO:61388980 Keywords : Sol-gel process * mtes/teos * Hydrophobic silica * mcm-41 Subject RIV: CA - Inorganic Chemistry OBOR OECD: Inorganic and nuclear chemistry Impact factor: 3.387, year: 2016

  20. Extraction of uranium from alkaline medium by aliquot-336 in different diluents

    Energy Technology Data Exchange (ETDEWEB)

    Shehata, F A; Elnadi, Y A; Aly, H F [Hot laboratories center, atomic energy authority 13758, Cairo, (Egypt); Ahmed, A S [Faculty of science, Cairo University, Giza, (Egypt)

    1995-10-01

    A study was made on the extraction of uranium from aqueous solutions containing sodium carbonate and sodium hydroxide in the presence of oxidizing agent (H{sub 2} O{sub 2}) by aliquot-336 dissolved in different diluents. The effect of different factors affecting the extraction equilibrium was experimented. From the results obtained, the extraction equilibrium was elaborated. From the effect of temperature on the extraction, The thermodynamic constants of the system were determined and discussed. 5 figs., 1 tab.

  1. Enhancement of electrocatalytic properties of carbonized polyaniline nanoparticles upon a hydrothermal treatment in alkaline medium

    International Nuclear Information System (INIS)

    Gavrilov, Nemanja; Vujkovic, Milica; Pasti, Igor A.; Ciric-Marjanovic, Gordana; Mentus, Slavko V.

    2011-01-01

    Highlights: → Carbonized polyaniline nanoparticles were treated hydrothermally in 1 M KOH. → Hydrothermal treatment improved the electrocatalytic activity towards ORR. → Significant effect of catalyst loading was evidenced too. → At the loading 0.5 mg cm -2 the 4e - reaction path was achieved. - Abstract: The electrocatalytic activity of carbonized polyaniline nanostructures (Carb-nanoPANI) towards oxygen reduction reaction (ORR), estimated in 0.1 mol dm -3 KOH solution, was significantly improved upon a hydrothermal treatment in 1 mol dm -3 KOH solution. Namely, the onset of ORR was shifted by ∼70 mV to more positive potentials, and the number of electrons consumed per O 2 molecule was enhanced in comparison to the original material. The number of electrons involved in ORR depended on loading, and with a loading of 0.5 mg cm -2 , for the potentials lower than -0.5 V vs SCE, the number of electrons approached 4. For this material, high stability of electrochemical behavior and resistance to the poisoning by ethanol was evidenced by potentiodynamic cycling.

  2. Enhancement of electrocatalytic properties of carbonized polyaniline nanoparticles upon a hydrothermal treatment in alkaline medium

    Energy Technology Data Exchange (ETDEWEB)

    Gavrilov, Nemanja; Vujkovic, Milica; Pasti, Igor A.; Ciric-Marjanovic, Gordana [University of Belgrade, Faculty of Physical Chemistry, Studentski trg 12-16, 11158 Belgrade (Serbia); Mentus, Slavko V., E-mail: slavko@ffh.bg.ac.rs [University of Belgrade, Faculty of Physical Chemistry, Studentski trg 12-16, 11158 Belgrade (Serbia); Serbian Academy of Sciences and Arts, Knez Mihajlova 35, 11158 Belgrade (Serbia)

    2011-10-30

    Highlights: > Carbonized polyaniline nanoparticles were treated hydrothermally in 1 M KOH. > Hydrothermal treatment improved the electrocatalytic activity towards ORR. > Significant effect of catalyst loading was evidenced too. > At the loading 0.5 mg cm{sup -2} the 4e{sup -} reaction path was achieved. - Abstract: The electrocatalytic activity of carbonized polyaniline nanostructures (Carb-nanoPANI) towards oxygen reduction reaction (ORR), estimated in 0.1 mol dm{sup -3} KOH solution, was significantly improved upon a hydrothermal treatment in 1 mol dm{sup -3} KOH solution. Namely, the onset of ORR was shifted by {approx}70 mV to more positive potentials, and the number of electrons consumed per O{sub 2} molecule was enhanced in comparison to the original material. The number of electrons involved in ORR depended on loading, and with a loading of 0.5 mg cm{sup -2}, for the potentials lower than -0.5 V vs SCE, the number of electrons approached 4. For this material, high stability of electrochemical behavior and resistance to the poisoning by ethanol was evidenced by potentiodynamic cycling.

  3. Preparation of Organized Mesoporous Silica from Sodium Metasilicate Solutions in Alkaline Medium using Nonionic Surfactants

    Czech Academy of Sciences Publication Activity Database

    Zukalová, Markéta; Rathouský, Jiří; Zukal, Arnošt

    2003-01-01

    Roč. 68, č. 10 (2003), s. 2019-2031 ISSN 0010-0765 Institutional research plan: CEZ:AV0Z4040901 Keywords : mesoporous SiO2 * sodium metasilicate * nonionic surfactants Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.041, year: 2003

  4. Effect of amino acids on the repression of alkaline protease synthesis in haloalkaliphilic Nocardiopsis dassonvillei

    Directory of Open Access Journals (Sweden)

    Amit K. Sharma

    2016-12-01

    Full Text Available A newly isolated salt-tolerant alkaliphilic actinomycete, Nocardiopsis dassonvillei strain OK-18 grows on mineral salts medium with glucose as carbon source. It also grows and produces protease with amino acids as sole carbon source. The synthesis of extracellular alkaline protease parallel to growth was repressible by substrate concentrations. The absolute production of the protease was delinked with growth under nutritional stress, as protease production was high, despite poor growth. When amino acids served as the sole source of carbon and nitrogen, the enzyme production was significantly controlled by the number of amino acids. Maximal protease production was achieved with proline, asparagine, tyrosine, alanine, methionine and valine as sole source of carbon and nitrogen in minimal medium. With the increasing number of different amino acids in the presence and absence of glucose, the protease production was synergistically lower as compared to complex medium.

  5. The Interstellar Medium

    CERN Document Server

    Lequeux, James

    2005-01-01

    Describing interstellar matter in our galaxy in all of its various forms, this book also considers the physical and chemical processes that are occurring within this matter. The first seven chapters present the various components making up the interstellar matter and detail the ways that we are able to study them. The following seven chapters are devoted to the physical, chemical and dynamical processes that control the behaviour of interstellar matter. These include the instabilities and cloud collapse processes that lead to the formation of stars. The last chapter summarizes the transformations that can occur between the different phases of the interstellar medium. Emphasizing methods over results, "The Interstellar Medium" is written for graduate students, for young astronomers, and also for any researchers who have developed an interest in the interstellar medium.

  6. Optical recording medium

    International Nuclear Information System (INIS)

    Andriech, A.; Bivol, V.; Tridukh, G.; Tsiuleanu, D.

    2002-01-01

    The invention relates of the micro- and optoelectronics, computer engineering ,in particular, to tjhe optical information media and may be used in hilography. Summary of the invention consists in that the optical image recording medium, containing a dielectric substrates, onto one surface of which there are placed in series a transparent electricity conducting layer, a photo sensitive recording layer of chalcogenic glass and a thin film electrode of aluminium, is provided with an optically transparent protective layer, applied into the thin film electrode. The result of the invention consists in excluding the dependence of chemical processes course into the medium upon environmental conditions

  7. Microbial reduction of 99Tc (as TcO4-) in anaerobic alkaline conditions

    International Nuclear Information System (INIS)

    Khizhnyak, T.; Simonoff, M.; Sergeant, C.; Simonoff, G.; Medvedeva-Lyalikova, N.N.

    2003-01-01

    The ability of bacteria to reduce pertechnetate in alkaline conditions was investigated using halophilic bacteria isolated from soda-lakes environments. Anaerobic halophilic bacteria were able to reduce as much as 0.25 mM pertechnetate, whereas no reduction took place without bacteria or in the presence of heat-killed bacteria. The results obtained showed reduction of Tc(VII)O 4 - to the Tc(V) and Tc(IV) at pH 10 in the carbonate-bicarbonate medium. About 57% of the total technetium was determined to be Tc(IV), 1-3% as a Tc(V) and 17-20% as a Tc(VII) after 1-3 days of incubation with bacteria. The microbial reduction of Tc(VII) in alkaline conditions has been suggested as a potential mechanism for the removal of Tc from contaminated environments or waste streams. (author)

  8. Hydrolysis of alkaline pretreated banana peel

    Science.gov (United States)

    Fatmawati, A.; Gunawan, K. Y.; Hadiwijaya, F. A.

    2017-11-01

    Banana peel is one of food wastes that are rich in carbohydrate. This shows its potential as fermentation substrate including bio-ethanol. This paper presented banana peel alkaline pretreatment and enzymatic hydrolysis. The pretreatment was intended to prepare banana peel in order to increase hydrolysis performance. The alkaline pretreatment used 10, 20, and 30% w/v NaOH solution and was done at 60, 70 and 80°C for 1 hour. The hydrolysis reaction was conducted using two commercial cellulose enzymes. The reaction time was varied for 3, 5, and 7 days. The best condition for pretreatment process was one conducted using 30% NaOH solution and at 80°C. This condition resulted in cellulose content of 90.27% and acid insoluble lignin content of 2.88%. Seven-day hydrolysis time had exhibited the highest reducing sugar concentration, which was7.2869 g/L.

  9. Roentgen contrast medium

    International Nuclear Information System (INIS)

    Tamborski, C.

    1989-01-01

    The patent deals with a roentgen contrast medium containing a perfluorinebrominealkylether of the formula C m F 2m+1 OC n F 2n Br dispersed in water, preferentially in the presence of a non-ionic dispersing agent such as a fluorinated amidoaminoxide. 2 tabs

  10. Radon in geological medium

    Energy Technology Data Exchange (ETDEWEB)

    Hricko, J [GEOCOMPLEX, a.s., Bratislava (Slovakia)

    1996-12-31

    The paper presented deals with behavior of the radon in geological medium and with some results of the radon survey in Bratislava and Kosice regions. 1) The a{sub v} has been detected in the holes 0.80 m deep. The density of observations - 3 reference areas (one represents 20 stations) per 1 km{sup 2}. The radon risk maps in 1:25000 and 1:50000 scales have been compiled. The 56.8% of the project area lies in low radon risk, 37.6% in medium radon risk and 5.6% in high radon risk. Follow-up monitoring of the equivalent volume radon activity (EVRA) at the flats, located in the areas with high radon risk of the surface layer, has showed values several times higher than Slovak limits (Marianka, Raca, Vajnory). The evidence that neotectonic is excellent medium for rising up emanation to the subsurface layer, is shown on the map. The tectonic zone of Liscie udolie in Bratislava-Karlova Ves area has been clearly detected by profile radon survey (a{sub v} > 50 kBq/m{sup 3}). 2) At present, northern half of the area of Kosice in question was covered by radon survey. The low and medium radon risks have been observed here, while localities with high radon risk are small in extent. The part of radon risk and soil permeability map from northern Kosice area is shown. (J.K.) 3 figs., 2 refs.

  11. Radon in geological medium

    International Nuclear Information System (INIS)

    Hricko, J.

    1995-01-01

    The paper presented deals with behavior of the radon in geological medium and with some results of the radon survey in Bratislava and Kosice regions. 1) The a v has been detected in the holes 0.80 m deep. The density of observations - 3 reference areas (one represents 20 stations) per 1 km 2 . The radon risk maps in 1:25000 and 1:50000 scales have been compiled. The 56.8% of the project area lies in low radon risk, 37.6% in medium radon risk and 5.6% in high radon risk. Follow-up monitoring of the equivalent volume radon activity (EVRA) at the flats, located in the areas with high radon risk of the surface layer, has showed values several times higher than Slovak limits (Marianka, Raca, Vajnory). The evidence that neotectonic is excellent medium for rising up emanation to the subsurface layer, is shown on the map. The tectonic zone of Liscie udolie in Bratislava-Karlova Ves area has been clearly detected by profile radon survey (a v > 50 kBq/m 3 ). 2) At present, northern half of the area of Kosice in question was covered by radon survey. The low and medium radon risks have been observed here, while localities with high radon risk are small in extent. The part of radon risk and soil permeability map from northern Kosice area is shown. (J.K.) 3 figs., 2 refs

  12. Oxidation catalysts on alkaline earth supports

    Science.gov (United States)

    Mohajeri, Nahid

    2017-03-21

    An oxidation catalyst includes a support including particles of an alkaline earth salt, and first particles including a palladium compound on the support. The oxidation catalyst can also include precious metal group (PMG) metal particles in addition to the first particles intermixed together on the support. A gas permeable polymer that provides a continuous phase can completely encapsulate the particles and the support. The oxidation catalyst may be used as a gas sensor, where the first particles are chemochromic particles.

  13. Heavy water production by alkaline water electrolysis

    International Nuclear Information System (INIS)

    Kamath, Sachin; Sandeep, K.C.; Bhanja, Kalyan; Mohan, Sadhana; Sugilal, G.

    2014-01-01

    Several heavy water isotope production processes are reported in literature. Water electrolysis in combination with catalytic exchange CECE process is considered as a futuristic process to increase the throughput and reduce the cryogenic distillation load but the application is limited due to the high cost of electricity. Any improvement in the efficiency of electrolyzers would make this process more attractive. The efficiency of alkaline water electrolysis is governed by various phenomena such as activation polarization, ohmic polarization and concentration polarization in the cell. A systematic study on the effect of these factors can lead to methods for improving the efficiency of the electrolyzer. A bipolar and compact type arrangement of the alkaline water electrolyzer leads to increased efficiency and reduced inventory in comparison to uni-polar tank type electrolyzers. The bipolar type arrangement is formed when a number of single cells are stacked together. Although a few experimental studies have been reported in the open literature, CFD simulation of a bipolar compact alkaline water electrolyzer with porous electrodes is not readily available.The principal aim of this study is to simulate the characteristics of a single cell compact electrolyzer unit. The simulation can be used to predict the Voltage-Current Density (V-I) characteristics, which is a measure of the efficiency of the process.The model equations were solved using COMSOL multi-physics software. The simulated V-I characteristic is compared with the experimental data

  14. Effect of Alkaline Stress on Some Morphophysiologic Characteristics of Two Varieties of Safflower (Carthamus tinctorius L.

    Directory of Open Access Journals (Sweden)

    Sh Bemany Golnabadi

    2016-12-01

    , shoot and root dry weight, Fv/Fm, PI, proline, total carbohydrate, malondialdehyde content, cha, chb, total chlorophyll, cartonoied content, potassium, sodium content and sodium to potassium rate were measured. Results and Discussion Result showed that with increasing alkaline stress, decreased shoot and root height, shoot and root dry weight. A similar result had observed previously in sugar beet. Researches have indicated that plants respond to elevated NaHCO3 concentrations in soil or in growing medium solution with decreased shoot and root growth. This could be due to either HCO3− or Na+. Many of the data test showed high pH as a key factor in limiting plant growth and development under alkaline conditions. 411 variety showed superiority compared to Sofeh cultivar in mentioned characteristics. Also, Fv/Fm and PI decreased under alkaline stress condition, whereas proline, total carbohydrate and malondialdehyde content increased. Also, the increases in proline and total carbohydrate content were reported in wheat under alkaline stress condition. Baghre and Roosta (2012 reported that Fv/Fm values and PI reduced under alkalinity stress. In the present experiment, alkaline stress decreased cha, chb and total chlorophyll whereas it increased cartonoied content. Yang et al., (2009a concluded that in alkalinity stress, the contents of Chl and Car in the barley plants decreased sharply with increased stress in comparison to salinity stress. They also stated that high pH might decrease contents of photosynthetic pigments. Potassium content decreased under alkaline stress condition whereas sodium and sodium to potassium rate increased. Also, Zhang and Chun-Sheng (2009 reported that with increasing alkaline stress, potassium content decreased in Lathyrus quinquenervius whereas, sodium content and sodium to potassium rate increase. In wheat stems, a decrease in potassium content and potassium to sodium rate and an increase in sodium content were also observed. A high

  15. Processing Methods of Alkaline Hydrolysate from Rice Husk

    Directory of Open Access Journals (Sweden)

    Olga D. Arefieva

    2017-07-01

    Full Text Available This paper devoted to finding processing methods of alkaline hydrolysate produced from rice husk pre-extraction, and discusses alkaline hydrolysate processing schemed and disengagement of some products: amorphous silica of various quality, alkaline lignin, and water and alkaline extraction polysaccharides. Silica samples were characterized: crude (air-dried, burnt (no preliminary water treatment, washed in distilled water, and washed in distilled water and burnt. Waste water parameters upon the extraction of solids from alkaline hydrolysate dropped a few dozens or thousand times depending on the applied processing method. Color decreased a few thousand times, turbidity was virtually eliminated, chemical oxygen demanded about 20–136 times; polyphenols content might decrease 50% or be virtually eliminated. The most prospective scheme obtained the two following solid products from rice husk alkaline hydrolysate: amorphous silica and alkaline extraction polysaccharide. Chemical oxygen demand of the remaining waste water decreased about 140 times compared to the silica-free solution.

  16. Alkaline solution/binder ratio as a determining factor in the alkaline activation of aluminosilicates

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz-Santaquiteria, C., E-mail: ruiz.cs@ietcc.csic.es [Eduardo Torroja Institute (CSIC), c/Serrano Galvache, n Degree-Sign 4, 28033 Madrid (Spain); Skibsted, J. [Instrument Centre for Solid-State NMR Spectroscopy, Interdisciplinary Nanoscience Center (iNANO), Department of Chemistry, Aarhus University, DK-8000 Aarhus C (Denmark); Fernandez-Jimenez, A.; Palomo, A. [Eduardo Torroja Institute (CSIC), c/Serrano Galvache, n Degree-Sign 4, 28033 Madrid (Spain)

    2012-09-15

    This study investigates the effect of the alkaline solution/binder (S/B) ratio on the composition and nanostructure of the reaction products generated in the alkaline activation of aluminosilicates. The experiments used two mixtures of fly ash and dehydroxylated white clay and for each of these, varying proportions of the solution components. The alkali activator was an 8 M NaOH solution (with and without sodium silicate) used at three S/B ratios: 0.50, 0.75 and 1.25. The {sup 29}Si, {sup 27}Al MAS NMR and XRD characterisation of the reaction products reveal that for ratios nearest the value delivering suitable paste workability, the reaction-product composition and structure depend primarily on the nature and composition of the starting materials and the alkaline activator used. However, when an excess alkaline activator is present in the system, the reaction products tend to exhibit SiO{sub 2}/Al{sub 2}O{sub 3} ratios of approximately 1, irrespective of the composition of the starting binder or the alkaline activator.

  17. Hexavalent chromium reduction by bacterial consortia and pure strains from an alkaline industrial effluent.

    Science.gov (United States)

    Piñón-Castillo, H A; Brito, E M S; Goñi-Urriza, M; Guyoneaud, R; Duran, R; Nevarez-Moorillon, G V; Gutiérrez-Corona, J F; Caretta, C A; Reyna-López, G E

    2010-12-01

    To characterize the bacterial consortia and isolates selected for their role in hexavalent chromium removal by adsorption and reduction. Bacterial consortia from industrial wastes revealed significant Cr(VI) removal after 15 days when incubated in medium M9 at pH 6·5 and 8·0. The results suggested chromium reduction. The bacterial consortia diversity (T-RFLP based on 16S rRNA gene) indicated a highest number of operational taxonomic units in an alkaline carbonate medium mimicking in situ conditions. However, incubations under such conditions revealed low Cr(VI) removal. Genomic libraries were obtained for the consortia exhibiting optimal Cr(VI) removal (M9 medium at pH 6·5 and 8·0). They revealed the dominance of 16S rRNA gene sequences related to the genera Pseudomonas/Stenotrophomonas or Enterobacter/Halomonas, respectively. Isolates related to Pseudomonas fluorescens and Enterobacter aerogenes were efficient in Cr(VI) reduction and adsorption to the biomass. Cr(VI) reduction was better at neutral pH rather than under in situ conditions (alkaline pH with carbonate). Isolated strains exhibited significant capacity for Cr(VI) reduction and adsorption. Bacterial communities from chromium-contaminated industrial wastes as well as isolates were able to remove Cr(VI). The results suggest a good potential for bioremediation of industrial wastes when optimal conditions are applied. Journal of Applied Microbiology © 2010 The Society for Applied Microbiology. No claim to Mexican Government works.

  18. Production, secretion, and stability of human secreted alkaline phosphatase in tobacco NT1 cell suspension cultures.

    Science.gov (United States)

    Becerra-Arteaga, Alejandro; Mason, Hugh S; Shuler, Michael L

    2006-01-01

    Tobacco NT1 cell suspension cultures secreting active human secreted alkaline phosphatase (SEAP) were generated for the first time as a model system to study recombinant protein production, secretion, and stability in plant cell cultures. The SEAP gene encodes a secreted form of the human placental alkaline phosphatase (PLAP). During batch culture, the highest level of active SEAP in the culture medium (0.4 U/mL, corresponding to approximately 27 mg/L) was observed at the end of the exponential growth phase. Although the level of active SEAP decreased during the stationary phase, the activity loss did not appear to be due to SEAP degradation (based on Western blots) but due to SEAP denaturation. The protein-stabilizing agents polyvinylpirrolidone (PVP) and bacitracin were added extracellularly to test for their ability to reduce the loss of SEAP activity during the stationary phase. Bacitracin (100 mg/L) was the most effective treatment at sustaining activity levels for up to 17 days post-subculture. Commercially available human placental alkaline phosphatase (PLAP) was used to probe the mechanism of SEAP deactivation. Experiments with PLAP in sterile and conditioned medium corroborated the denaturation of SEAP by factors generated by cell growth and not due to simple proteolysis. We also show for the first time that the factors promoting activity loss are heat labile at 95 degrees C but not at 70 degrees C, and they are not inactivated after a 5 day incubation period under normal culture conditions (27 degrees C). In addition, there were no significant changes in pH or redox potential when comparing sterile and cell-free conditioned medium during PLAP incubation, indicating that these factors were unimportant.

  19. Electrochemical investigations of Co3Fe-RGO as a bifunctional catalyst for oxygen reduction and evolution reactions in alkaline media

    Science.gov (United States)

    Kumar, Surender; Kumar, Divyaratan; Kishore, Brij; Ranganatha, Sudhakar; Munichandraiah, Nookala; Venkataramanan, Natarajan S.

    2017-10-01

    Nanoparticles of Co3Fe alloy is prepared on reduced graphene oxide (RGO) sheets by modified polyol method. Synthesized alloy particles are characterized by various physicochemical techniques. TEM and SEM pictures showed homogeneously dispersed alloy nanoparticles on the RGO sheets. Electrochemistry of alloy nanoparticles is investigated in alkaline medium. The result shows that oxygen evaluation reaction (OER) activity of Co3Fe-RGO is higher than Pt-black particles. RDE studies in alkaline medium shows that oxygen reduction reaction (ORR) follow four electron pathway. It is suggest that Co3Fe-RGO is an efficient non-precious catalyst for oxygen (ORR/OER) reactions in alkaline electrolyte for PEMFC applications.

  20. Concept medium program

    DEFF Research Database (Denmark)

    Bjerrum, Peter

    2003-01-01

    The present essays is an attempt to dertermine the architecural project of the 21st century in realation to a modern conception of space as the medium of architecture, and of society as its program. This attempt adopts the internal point of view of an architect in describing a modern architectural...... project within the framework: concept - program, these notions being concieved as spatial representations primarily and immediately "given" to architecture....

  1. Alkaline protease contributes to pyocyanin production in Pseudomonas aeruginosa.

    Science.gov (United States)

    Iiyama, Kazuhiro; Takahashi, Eigo; Lee, Jae Man; Mon, Hiroaki; Morishita, Mai; Kusakabe, Takahiro; Yasunaga-Aoki, Chisa

    2017-04-01

    The role of the alkaline protease (AprA) in pyocyanin production in Pseudomonas aeruginosa was investigated. AprA was overproduced when a plasmid carrying the aprA gene was introduced to an aprA-deletion mutant strain, EG03; thus, aprA-complemented EG03 was used as an overproducing strain. The complemented strain produced higher pyocyanin than the mutant strain in all commercially available media evaluated. Particularly, pyocyanin production was higher in the complemented than in the parental strain in brain-heart infusion and tryptic soy broths. These results suggested that protein degradation products by AprA were utilized for pyocyanin production. Protein-rich media were used in subsequent validation studies. Similar results were obtained when the basal medium was supplemented with casein or skim milk as the sole organic nitrogen source. However, gelatin failed to induce abundant pyocyanin production in the complemented strain, despite the presence of protein degradation products by AprA as assessed by SDS-PAGE. Thus, gelatin degradation products may not be suitable for pyocyanin synthesis. In conclusion, AprA could contribute to pyocyanin production in the presence of several proteins or peptides. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  2. Temperature Dependence of Mineral Solubility in Water. Part 2. Alkaline and Alkaline Earth Bromides

    Science.gov (United States)

    Krumgalz, B. S.

    2018-03-01

    Databases of alkaline and alkaline earth bromide solubilities in water at various temperatures were created using experimental data from publications over about the last two centuries. Statistical critical evaluation of the created databases was produced since there were enough independent data sources to justify such evaluation. The reliable experimental data were adequately described by polynomial expressions over various temperature ranges. Using the Pitzer approach for ionic activity and osmotic coefficients, the thermodynamic solubility products for the discussed bromide minerals have been calculated at various temperature intervals and also represented by polynomial expressions.

  3. Net alkalinity and net acidity 2: Practical considerations

    Science.gov (United States)

    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 mine drainage treatment can lead to systems with insufficient Alkalinity to neutralize metal and H+ acidity and is not recommended. The use of net alkalinity = -Hot Acidity titration is recommended for the planning of mine drainage treatment. The use of net alkalinity = (Alkalinitymeasured - Aciditycalculated) is recommended with some cautions

  4. Kinetics of the methylparathion hydrolysis in aqueous medium

    International Nuclear Information System (INIS)

    Manzanilla, J.; Barcelo, M.; Reyes, O.

    1997-01-01

    The kinetics of alkaline hydrolysis of methylparathion was studied at different temperatures (0-50 Centigrade) in the p H range of 8-12 by ultraviolet-visible absorption spectroscopy. Optimum p H and wavelength conditions were defined to carry out the simultaneous determination of methylparathion and one of its hydrolysis product, paranitrophenol, in buffered aqueous medium. Based on the experimental data and the mathematical equation of the kinetics, a rate constant (k) of first-order and an activation energy (Ea) of 9.2 Kcal/mol, were estimated. (Author) activation energy (Ea) of 9.2 Kcal/mol, were estimated. (Author)

  5. RES Hydrogen: efficient pressurised alkaline electrolysers

    DEFF Research Database (Denmark)

    Bowen, Jacob R.; Bentzen, Janet Jonna; Jørgensen, Peter Stanley

    The RESelyser project addresses issues associated with coupling alkaline electrolysis to renewable energy sources such as electrode stability and gas purity by implementing improved electrodes and a new separator membrane concept. The project aims to improve performance, operation pressure...... and reduce system cost. The project supports DTU Energy's activities on electrodes within the larger FCH-JU project. The overall project demonstrated: improved electrode efficiency also during cyclic operation, safe gas purity at a system pressure of 30 bar, 10 kW stack operation and estimated system costs...

  6. Alkaline carbonates in blast furnace process

    Directory of Open Access Journals (Sweden)

    P. Besta

    2014-10-01

    Full Text Available The production of iron in blast furnaces is a complex of physical, chemical and mechanical processes. The input raw materials contain not only metallic components, but also a number of negative elements. The most important negative elements include alkaline carbonates. They can significantly affect the course of the blast furnace process and thus the overall performance of the furnace. As a result of that, it is essential to accurately monitor the alkali content in the blast furnace raw materials. The article analyzes the alkali content in input and output raw materials and their impact on the blast furnace process.

  7. Persistently increased intestinal fraction of alkaline phosphatase

    DEFF Research Database (Denmark)

    Nathan, E; Baatrup, G; Berg, H

    1984-01-01

    Persistent elevation of the intestinal fraction of the alkaline phosphatase (API) as an isolated finding has to our knowledge not been reported previously. It was found in a boy followed during a period of 5.5 years. The only symptom was transient periodic fatigue observed at home, but not apparent...... during hospitalization. His blood type was O, RH+, Le (a-, b+) and he was a secretor of H-substance, which may be associated with rising API activity after fat-loading. In this case API was unchanged after fat-loading. Neither intestinal nor liver diseases were found, and no other cause for the elevated...

  8. Alkaline erosion of CR 39 polymer surfaces

    International Nuclear Information System (INIS)

    Faiman, Laurence

    2009-01-01

    We have investigated the mechanism of erosion of CR 39 polymer in alkaline environments. We observed the kinetics of absorption of water and methanol into both unirradiated and γ-irradiated samples. We use a capillary model to interpret our results. We etched our samples in both KOH solutions, and KOH solutions doped with methanol. Etch rate was desensitizing to γ-irradiation when KOH concentration approached saturation, but KOH solutions doped with methanol were not desensitizing, unlike with nuclear tracks. We account for this difference

  9. Electrochemistry of Some New Alkaline Battery Electrodes

    Science.gov (United States)

    1976-02-01

    1NýT;7 ~~ AFAPI 4TR- 75)aI Electrochemistry of Somwý New Alkaline V CI RG, 0OTNME Dr/ David F., ’Pickett, IM Wayue ’,Hisb’q Mr. R ic ha rd A I Mid...adding ZnO to the electi-olyte (saturated) and usi .j the interc:ell conrec;tor d isr:ussed earlier ,itLh el4cc.roploated zinc ag inst. the silver fo

  10. Alkaline chemistry of transuranium elements and technetium and the treatment of alkaline radioactive wastes

    International Nuclear Information System (INIS)

    Delegard, C.H.; Peretrukhin, V.F.; Shilov, V.P.; Pikaev, A.K.

    1995-05-01

    Goal of this survey is to generalize the known data on fundamental physical-chemical properties of TRUs and Tc, methods for their isolation, and to provide recommendations that will be useful for partitioning them from alkaline high-level wastes

  11. Alkaline chemistry of transuranium elements and technetium and the treatment of alkaline radioactive wastes

    Energy Technology Data Exchange (ETDEWEB)

    Delegard, C.H. [Westinghouse Hanford Co., Richland, WA (United States); Peretrukhin, V.F.; Shilov, V.P.; Pikaev, A.K. [Russian Academy of Sciences (Russian Federation). Inst. of Physical Chemistry

    1995-05-01

    Goal of this survey is to generalize the known data on fundamental physical-chemical properties of TRUs and Tc, methods for their isolation, and to provide recommendations that will be useful for partitioning them from alkaline high-level wastes.

  12. Inhibition of Alkaline Flocculation by Algal Organic Matter for Chlorella vulgaris

    Energy Technology Data Exchange (ETDEWEB)

    Vandamme, Dries; Beuckels, Annelies; Vadelius, Eric; Depraetere, Orily; Noppe, Wim; Dutta, Abhishek; Foubert, Imogen; Laurens, Lieve; Muylaert, Koenraad

    2016-01-01

    Alkaline flocculation is a promising strategy for the concentration of microalgae for bulk biomass production. However, previous studies have shown that biological changes during the cultivation negatively affect flocculation efficiency. The influence of changes in cell properties and in the quality and composition of algal organic matter (AOM) were studied using Chlorella vulgaris as a model species. In batch cultivation, flocculation was increasingly inhibited over time and mainly influenced by changes in medium composition, rather than biological changes at the cell surface. Total carbohydrate content of the organic matter fraction sized bigger than 3 kDa increased over time and this fraction was shown to be mainly responsible for the inhibition of alkaline flocculation. The monosaccharide identification of this fraction mainly showed the presence of neutral and anionic monosaccharides. An addition of 30–50 mg L-1 alginic acid, as a model for anionic carbohydrate polymers containing uronic acids, resulted in a complete inhibition of flocculation. Furthermore, these results suggest that inhibition of alkaline flocculation was caused by interaction of anionic polysaccharides leading to an increased flocculant demand over time.

  13. Isotherms of ion exchange on titanates of alkaline metals

    International Nuclear Information System (INIS)

    Fillina, L.P.; Belinskaya, F.A.

    1986-01-01

    Present article is devoted to isotherms of ion exchange on titanates of alkaline metals. Therefore, finely dispersed hydrated titanates of alkaline metals (lithium, sodium, potassium) with ion exchange properties are obtained by means of alkaline hydrolysis of titanium chloride at high ph rates. Sorption of cations from salts solution of Li 2 SO 4 , NaNO 3 , Ca(NO 3 ) 2 , AgNO 3 by titanates is studied.

  14. Acid transformation of bauxite residue: Conversion of its alkaline characteristics

    OpenAIRE

    Kong, X.; Li, M.; Xue, S.; Hartley, W.; Chen, C.; Wu, C.; Li, X.; Li, Y.

    2016-01-01

    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...

  15. Spectroscopic characterization of alkaline earth uranyl carbonates

    International Nuclear Information System (INIS)

    Amayri, Samer; Reich, Tobias; Arnold, Thuro; Geipel, Gerhard; Bernhard, Gert

    2005-01-01

    A series of alkaline uranyl carbonates, M[UO 2 (CO 3 ) 3 ].nH 2 O (M=Mg 2 , Ca 2 , Sr 2 , Ba 2 , Na 2 Ca, and CaMg) was synthesized and characterized by inductively coupled plasma mass spectrometry (ICP-MS) and atomic absorption spectrometry (AAS) after nitric acid digestion, X-ray powder diffraction (XRD), and thermal analysis (TGA/DTA). The molecular structure of these compounds was characterized by extended X-ray absorption fine-structure (EXAFS) spectroscopy and X-ray photoelectron spectroscopy (XPS). Crystalline Ba 2 [UO 2 (CO 3 ) 3 ].6H 2 O was obtained for the first time. The EXAFS analysis showed that this compound consists of (UO 2 )(CO 3 ) 3 clusters similar to the other alkaline earth uranyl carbonates. The average U-Ba distance is 3.90+/-0.02A.Fluorescence wavelengths and life times were measured using time-resolved laser-induced fluorescence spectroscopy (TRLFS). The U-O bond distances determined by EXAFS, TRLFS, XPS, and Raman spectroscopy agree within the experimental uncertainties. The spectroscopic signatures observed could be useful for identifying uranyl carbonate species adsorbed on mineral surfaces

  16. Activation of Alkaline Irrigation Fluids in Endodontics

    Directory of Open Access Journals (Sweden)

    Laurence J. Walsh

    2017-10-01

    Full Text Available In conventional endodontic treatment, alkaline solutions of sodium hypochlorite (NaOCl and ethylenediaminetetraacetic acid (EDTA are used in combination to disinfect the root canal system and to eliminate debris and smear layers. An important concept that has emerged over recent years is the use of active physical methods for agitating these fluids to improve their penetration within areas that are not reached by endodontic instruments and to accelerate the chemical actions of these alkaline fluids against planktonic microorganisms, biofilms, soft tissue remnants and smear layers. Ultrasonic agitation and more recently pulsed lasers have emerged as two promising methods for activating endodontic irrigation fluids. Ultrasonic agitation with piezoelectric devices employs a moving tip, while laser agitation uses a stationary tip. Both methods cause cavitation, followed by implosions and shear forces which assist with debridement. Fluid streaming further enhances the activity of the fluids. While agitation enhances performance of irrigants, extrusion of fluids from the root canal during activation is a hazard that must be controlled.

  17. DNA DAMAGE QUANTITATION BY ALKALINE GEL ELECTROPHORESIS.

    Energy Technology Data Exchange (ETDEWEB)

    SUTHERLAND,B.M.; BENNETT,P.V.; SUTHERLAND, J.C.

    2004-03-24

    Physical and chemical agents in the environment, those used in clinical applications, or encountered during recreational exposures to sunlight, induce damages in DNA. Understanding the biological impact of these agents requires quantitation of the levels of such damages in laboratory test systems as well as in field or clinical samples. Alkaline gel electrophoresis provides a sensitive (down to {approx} a few lesions/5Mb), rapid method of direct quantitation of a wide variety of DNA damages in nanogram quantities of non-radioactive DNAs from laboratory, field, or clinical specimens, including higher plants and animals. This method stems from velocity sedimentation studies of DNA populations, and from the simple methods of agarose gel electrophoresis. Our laboratories have developed quantitative agarose gel methods, analytical descriptions of DNA migration during electrophoresis on agarose gels (1-6), and electronic imaging for accurate determinations of DNA mass (7-9). Although all these components improve sensitivity and throughput of large numbers of samples (7,8,10), a simple version using only standard molecular biology equipment allows routine analysis of DNA damages at moderate frequencies. We present here a description of the methods, as well as a brief description of the underlying principles, required for a simplified approach to quantitation of DNA damages by alkaline gel electrophoresis.

  18. DENSE MEDIUM CYCLONE OPTIMIZATON

    Energy Technology Data Exchange (ETDEWEB)

    Gerald H. Luttrell; Chris J. Barbee; Peter J. Bethell; Chris J. Wood

    2005-06-30

    Dense medium cyclones (DMCs) are known to be efficient, high-tonnage devices suitable for upgrading particles in the 50 to 0.5 mm size range. This versatile separator, which uses centrifugal forces to enhance the separation of fine particles that cannot be upgraded in static dense medium separators, can be found in most modern coal plants and in a variety of mineral plants treating iron ore, dolomite, diamonds, potash and lead-zinc ores. Due to the high tonnage, a small increase in DMC efficiency can have a large impact on plant profitability. Unfortunately, the knowledge base required to properly design and operate DMCs has been seriously eroded during the past several decades. In an attempt to correct this problem, a set of engineering tools have been developed to allow producers to improve the efficiency of their DMC circuits. These tools include (1) low-cost density tracers that can be used by plant operators to rapidly assess DMC performance, (2) mathematical process models that can be used to predict the influence of changes in operating and design variables on DMC performance, and (3) an expert advisor system that provides plant operators with a user-friendly interface for evaluating, optimizing and trouble-shooting DMC circuits. The field data required to develop these tools was collected by conducting detailed sampling and evaluation programs at several industrial plant sites. These data were used to demonstrate the technical, economic and environmental benefits that can be realized through the application of these engineering tools.

  19. Computation as Medium

    DEFF Research Database (Denmark)

    Jochum, Elizabeth Ann; Putnam, Lance

    2017-01-01

    Artists increasingly utilize computational tools to generate art works. Computational approaches to art making open up new ways of thinking about agency in interactive art because they invite participation and allow for unpredictable outcomes. Computational art is closely linked...... to the participatory turn in visual art, wherein spectators physically participate in visual art works. Unlike purely physical methods of interaction, computer assisted interactivity affords artists and spectators more nuanced control of artistic outcomes. Interactive art brings together human bodies, computer code......, and nonliving objects to create emergent art works. Computation is more than just a tool for artists, it is a medium for investigating new aesthetic possibilities for choreography and composition. We illustrate this potential through two artistic projects: an improvisational dance performance between a human...

  20. Spiegel. Medium. Kunst

    DEFF Research Database (Denmark)

    Kacunko, Slavko

    of this kind as the marks of a meta-complex of method out of which new models of the image continually arise. The waxing intangibility of proliferating images be they of the mind, in dreams, through gestures, and the equally rampant growth of microstructuring in allocations of knowledge lay a challenge before...... to research. As a void in the apprehension of the world, the mirror obtained a scholarly perspective and the more so in areas beyond its own qualities as a medium, i.e. in images and metaphor, the paradigms of all research looking to image and text. This investigation sets out to comprehend paradoxes......, and space (albeit no expanse) is there to consider the methodological pros and cons of such a selective approach. Even in this synopsis, it has to be and can be stated that what makes for the affinities between psychological, literary and image-research approaches in research on the mirror is the shared...

  1. The diffuse interstellar medium

    Science.gov (United States)

    Cox, Donald P.

    1990-01-01

    The last 20 years of the efforts to understand the diffuse ISM are reviewed, with recent changes of fundamental aspects being highlighted. Attention is given to the interstellar pressure and its components, the weight of the ISM, the midplane pressure contributions, and pressure contributions at 1 kpc. What velocity dispersions, cosmic ray pressure, and magnetic field pressure that can be expected for a gas in a high magnetic field environment is addressed. The intercloud medium is described, with reference to the work of Cox and Slavin (1989). Various caveats are discussed and a number of areas for future investigation are identified. Steps that could be taken toward a successful phase segregation model are discussed.

  2. Cloned Bacillus subtilis alkaline protease (aprA) gene showing high level of keratinolytic activity.

    Science.gov (United States)

    Zaghloul, T I

    1998-01-01

    The Bacillus subtilis alkaline protease(aprA) gene was previously cloned on a pUBHO-derivative plasmid. High levels of expression and gene stability were demonstrated when B. subtilis cells were grown on the laboratory medium 2XSG. B. subtilis cells harboring the multicopy aprA gene were grown on basal medium, supplemented with 1 % chicken feather as a source of energy, carbon, and nitrogen. Proteolytic and keratinolytic activities were monitored throughout the cultivation time. A high level of keratinolytic activity was obtained, and this indicates that alkaline protease is acting as a keratinase. Furthermore, considerable amounts of soluble proteins and free amino acids were obtained as a result of the enzymatic hydrolysis of feather. Biodegradation of feather waste using these cells represents an alternative way to improve the nutritional value of feather, since feather waste is currently utilized on a limited basis as a dietary protein supplement for animal feedstuffs. Moreover, the release of free amino acids from feather and the secreted keratinase enzyme would promote industries based on feather waste.

  3. A newly high alkaline lipase: an ideal choice for application in detergent formulations

    Directory of Open Access Journals (Sweden)

    Cherif Slim

    2011-11-01

    Full Text Available Abstract 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.

  4. Kinetics and Mechanistic Study of the Ruthenium(III Catalysed Oxidative Decarboxylation of L-Proline by Alkaline Heptavalent Manganese (Stopped flow technique

    Directory of Open Access Journals (Sweden)

    R. S. Shettar

    2005-01-01

    Full Text Available The kinetics of ruthenium(III catalysed oxidation of L-Proline by permanganate in alkaline medium at a constant ionic strength has been studied spectrophotometrically using a rapid kinetic accessory. The reaction between permanganate and L-Proline in alkaline medium exhibits 2:1 stoichiometry (KMnO4: L-Proline. The reaction shows first order dependence on [permanganate] and [ruthenium(III] and apparent less than unit order dependence each in L-Proline and alkali concentrations. Reaction rate increases with increase in ionic strength and decrease in solvent polarity of the medium. Initial addition of reaction products did not affect the rate significantly. A mechanism involving the formation of a complex between catalyst and substrate has been proposed. The activation parameters were computed with respect to the slow step of the mechanism and discussed

  5. Hydrogen production by alkaline water electrolysis

    Directory of Open Access Journals (Sweden)

    Diogo M. F. Santos

    2013-01-01

    Full Text Available Water electrolysis is one of the simplest methods used for hydrogen production. It has the advantage of being able to produce hydrogen using only renewable energy. To expand the use of water electrolysis, it is mandatory to reduce energy consumption, cost, and maintenance of current electrolyzers, and, on the other hand, to increase their efficiency, durability, and safety. In this study, modern technologies for hydrogen production by water electrolysis have been investigated. In this article, the electrochemical fundamentals of alkaline water electrolysis are explained and the main process constraints (e.g., electrical, reaction, and transport are analyzed. The historical background of water electrolysis is described, different technologies are compared, and main research needs for the development of water electrolysis technologies are discussed.

  6. Alkaline lixiviation of uranium in granitic pegmatite

    International Nuclear Information System (INIS)

    Jambor, S.

    1980-06-01

    The work described herein concerns the determination of the experimental optimum conditions for the alkaline lixiviation of uranium based on the following parameters: time, pH, temperature, density and grane size. The samples were obtained from the Supamo complex, near the Currupia river in the Piar District of the Bolivar State in Venezuela. They have a granitic composition and graphitic texture. The uranium was found in them as a secondary oxidized mineral of green-yellow colour localized in fractures fissures, intergranular spaces and also in the mica as. Secondary uranitite. The lixiviation process was carried out using Na 2 CO 3 /NaHCO 3 buffer solution and for 100 gr. samples the best values for an efficient process were found by using 170 mesh grane size and 500 ml of pH buffer at 70 0 C for a 24 hour time period. (author)

  7. Ethylenediaminetetraacetates of neodymium and alkaline earth metals

    International Nuclear Information System (INIS)

    Barinov, A.V.; Pechurova, L.I.; Martynenko, K.I.; Popov, K.I.; Spitsyn, V.I.

    1977-01-01

    The possibilities have been studied of the formation of polynuclear complexonates of alkaline-earth metals (Ca, Sr, and Ba) based on neodymium derivatives EDTA of the composition NdA - . By pH-metry, electron spectroscopy, and derivatography it has been shown that the structure of complexes M 2 (NdA) 2 (where M- Ca, Sr, or Ba; A- EDTA) in the solution is not polynuclear. Hydroxopolynuclear complexes do not form under conditions studied. The data obtained agree with an assumption about polynuclear structure of the solid complex Ca(NdA) 2 x17 H 2 O and gradual weakening of the polynuclear nature upon substitution of Ca 2+ with Sr 2+ and Ba 2+

  8. Corrosion of copper in alkaline chloride environments

    International Nuclear Information System (INIS)

    King, F.

    2002-08-01

    The available literature information on the corrosion and electrochemical behaviour of copper in alkaline environments has been reviewed. The purpose of the review was to assess the impact of an alkaline plume from cementitious material on the corrosion behaviour of a copper canister in an SKB-3 type repository. The effect of the evolution of the environmental conditions within the repository have been considered, including the effects of temperature, redox conditions, pore-water salinity and pH. If the pore-water pH increases prior to the establishment of anoxic conditions, the canister surface will passivate as the pore-water pH exceeds a value of ∼ pH 9. Passivation will result from the formation of a duplex Cu 2 O/Cu(OH) 2 film. The corrosion potential will be determined by the equilibrium potential for the Cu 2 O/Cu(OH) 2 couple under oxic conditions, or by the Cu/Cu 2 O redox couple under anoxic conditions (in the absence of sulphide). Pitting corrosion is only likely to occur early in the evolution of the repository environment, whilst the canister is still relatively cool ( 2 available to support localised corrosion, and prior to the increase in pore-water pH and salinity. The subsequent increase in canister surface temperature, pore-water pH and salinity, and decrease in O 2 will make pit initiation less likely, although the canister will remain passive provided the pore-water pH is maintained above pH 9. The higher the pore-water pH, the more strongly the canister is passivated and the less likely the surface is to undergo localised attack. If the pore-water salinity increases prior to the increase in pH, there could be a period of active canister corrosion before passivation occurs.Under these circumstances, the corrosion potential will be a true mixed potential, determine by the relative kinetics of Cu dissolution as CuCl 2 - and of the reduction of O 2 . The development of anoxic conditions and an increase in pore-water sulphide concentration will

  9. Retention of alkaline earth elements in man

    International Nuclear Information System (INIS)

    Newton, D.

    1990-06-01

    The data on human metabolism and long-term retention of alkaline earth elements ( 133 Ba injected into six healthy male volunteers at age 25-81 y and 45 Ca and 85 Sr received by one healthy male volunteer) are presented. Excreta were collected for 2-3 weeks after injection of the tracer into an antecubital vein. Activity in urine, ashed faeces and early samples of blood plasma was determined by gamma-ray scintillation spectrometry. Whole body retention has been assessed through serial measurements of body radioactivity. The injected 133 Ba apparently became mainly skeletal within several days, much earlier than predicted by the ICRP model. The whole-body retention at 32 d ranged from 5 to 14%, the rate of loss correlating with the excretory plasma clearance rate. No age-related trends were identified in the metabolism of Ca and Sr. 2 refs, 2 figs

  10. Properties of cathode materials in alkaline cells

    International Nuclear Information System (INIS)

    Salkind, A.J.; McBreen, J.; Freeman, R.; Parkhurst, W.A.

    1985-01-01

    Conventional and new cathode materials in primary and secondary alkaline cells were investigated for stability, structure, electrochemical reversibility and efficiency. Included were various forms of AgO for reserve-type silver-zinc batteries, a new material - AgNiO/sub 2/ - and several nickel electrodes for nickel-cadmium and nickel-hydrogen cells for aerospace applications. A comparative study was made of the stability of electroformed and chemically prepared AgO. Stability was correlated with impurities detected by XPS and SAM. After the first discharge AgNiO/sub 2/ can be recharged to the monovalent level. The discharge product is predominantly silver. Plastic-bonded nickel electrodes display a second plateau on discharge. Additions of Co(OH)/sub 2/ largely eliminate this

  11. Alkaline pulping of some eucalypts from Sudan.

    Science.gov (United States)

    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.

  12. Corrosion of copper in alkaline chloride environments

    Energy Technology Data Exchange (ETDEWEB)

    King, F. [Integrity Corrosion Consulting Ltd., Calgary (Canada)

    2002-08-01

    The available literature information on the corrosion and electrochemical behaviour of copper in alkaline environments has been reviewed. The purpose of the review was to assess the impact of an alkaline plume from cementitious material on the corrosion behaviour of a copper canister in an SKB-3 type repository. The effect of the evolution of the environmental conditions within the repository have been considered, including the effects of temperature, redox conditions, pore-water salinity and pH. If the pore-water pH increases prior to the establishment of anoxic conditions, the canister surface will passivate as the pore-water pH exceeds a value of {approx} pH 9. Passivation will result from the formation of a duplex Cu{sub 2}O/Cu(OH){sub 2} film. The corrosion potential will be determined by the equilibrium potential for the Cu{sub 2}O/Cu(OH){sub 2} couple under oxic conditions, or by the Cu/Cu{sub 2}O redox couple under anoxic conditions (in the absence of sulphide). Pitting corrosion is only likely to occur early in the evolution of the repository environment, whilst the canister is still relatively cool (<40 deg C), whilst there is still O{sub 2} available to support localised corrosion, and prior to the increase in pore-water pH and salinity. The subsequent increase in canister surface temperature, pore-water pH and salinity, and decrease in O{sub 2} will make pit initiation less likely, although the canister will remain passive provided the pore-water pH is maintained above pH 9. The higher the pore-water pH, the more strongly the canister is passivated and the less likely the surface is to undergo localised attack. If the pore-water salinity increases prior to the increase in pH, there could be a period of active canister corrosion before passivation occurs.Under these circumstances, the corrosion potential will be a true mixed potential, determine by the relative kinetics of Cu dissolution as CuCl{sub 2} - and of the reduction of O{sub 2}. The development

  13. Alkaline batteries for hybrid and electric vehicles

    Science.gov (United States)

    Haschka, F.; Warthmann, W.; Benczúr-Ürmössy, G.

    Forced by the USABC PNGV Program and the EZEV regulation in California, the development of hybrid vehicles become more strong. Hybrids offer flexible and unrestricted mobility, as well as pollution-free driving mode in the city. To achieve these requirements, high-power storage systems are demanded fulfilled by alkaline batteries (e.g., nickel/cadmium, nickel/metal hydride). DAUG has developed nickel/cadmium- and nickel/metal hydride cells in Fibre Technology of different performance types (up to 700 W/kg peak power) and proved in electric vehicles of different projects. A special bipolar cell design will meet even extreme high power requirements with more than 1000 W/kg peak power. The cells make use of the Recom design ensuring high power charge ability at low internal gas pressure. The paper presents laboratory test results of cells and batteries.

  14. Alkaline batteries for hybrid and electric vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Haschka, F.; Warthmann, W.; Benczur-Uermoessy, G. [DAUG Deutsche Automobilgesellschaft, Esslingen (Germany)

    1998-03-30

    Forced by the USABC PNGV Program and the EZEV regulation in California, the development of hybrid vehicles become more strong. Hybrids offer flexible and unrestricted mobility, as well as pollution-free driving mode in the city. To achieve these requirements, high-power storage systems are demanded fulfilled by alkaline batteries (e.g. nickel/cadmium, nickel/metal hydride). DAUG has developed nickel/cadmium- and nickel/metal hydride cells in Fibre Technology of different performance types (up to 700 W/kg peak power) and proved in electric vehicles of different projects. A special bipolar cell design will meet even extreme high power requirements with more than 1000 W/kg peak power. The cells make use of the Recom design ensuring high power charge ability at low internal gas pressure. The paper presents laboratory test results of cells and batteries. (orig.)

  15. Enzymatic Hydrolysis of Alkaline Pretreated Coconut Coir

    Directory of Open Access Journals (Sweden)

    Akbarningrum Fatmawati

    2013-06-01

    Full Text Available The purpose of this research is to study the effect of concentration and temperature on the cellulose and lignin content, and the reducing sugars produced in the enzymatic hydrolysis of coconut coir. In this research, the coconut coir is pretreated using 3%, 7%, and 11% NaOH solution at 60oC, 80oC, and 100oC. The pretreated coir were assayed by measuring the amount of cellulose and lignin and then hydrolysed using Celluclast and Novozyme 188 under various temperature (30oC, 40oC, 50oC and pH (3, 4, 5. The hydrolysis results were assayed for the reducing sugar content. The results showed that the alkaline delignification was effective to reduce lignin and to increase the cellulose content of the coir. The best delignification condition was observed at 11% NaOH solution and 100oC which removed 14,53% of lignin and increased the cellulose content up to 50,23%. The best condition of the enzymatic hydrolysis was obtained at 50oC and pH 4 which produced 7,57 gr/L reducing sugar. © 2013 BCREC UNDIP. All rights reservedReceived: 2nd October 2012; Revised: 31st January 2013; Accepted: 6th February 2013[How to Cite: Fatmawati, A., Agustriyanto, R., Liasari, Y. (2013. Enzymatic Hydrolysis of Alkaline Pre-treated Coconut Coir. Bulletin of Chemical Reaction Engineering & Catalysis, 8 (1: 34-39 (doi:10.9767/bcrec.8.1.4048.34-39[Permalink/DOI: http://dx.doi.org/10.9767/bcrec.8.1.4048.34-39] | View in  |

  16. Application of alkaline waterflooding to a high acidity crude oil

    Energy Technology Data Exchange (ETDEWEB)

    Sayyouh, M.H. (King Sand Univ., Riyadh (SA). Petroleum Engineering Dept.); Abdel-Waly, A.; Osman, A. (Cairo Univ. (EG). Petroleum Engineering Dept.); Awara, A.Z. (Geisum Oil Company, Cairo (EG))

    The enhanced recovery of a high acidity crude oil (South Geisum crude) by alkaline solutions is studied. Acidity, interfacial tension, and contact angle, were investigated. Displacement tests were carried out to study the effect of alkaline slug concentration, slug size, oil alkali type, temperature and viscosity on recovery. The interfacial tension between crude oil and formation water decreases with increasing alkaline concentration until a minimum, after which it increases again. Contact angle measurements indicated oil-wetting conditions that increase by the addition of alkaline solutions. At the early stages of displacement, oil recovery increases with increasing alkaline concentration until a maximum at 4% by weight NaOH concentration. Also, at such early stages, an excessive increase in alkaline concentration results in lower oil recovery. On the other hand, after the injection of many pore volumes of water, oil recovery is almost the same regardless of the alkaline concentration. Oil recovery increases with increasing alkaline slug size until a maximum at 15% PV. Sodium hydroxide slugs produce more oil recovery than sodium carbonate slugs. Oil recovery increases with increasing temperature (from 25 to 55{sup 0}C) and decreasing oil viscosity.

  17. Alkaline protease production on date waste by an alkalophilic ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-05-16

    May 16, 2008 ... After 72 h incubation in a shaker incubator ... different incubation times (0 to 72 h) were investigated. Alkaline .... of alkaline protease (75%) and 24% of total protein is precipitated. ... starches and wheat flour as carbon source on protease production .... JP 395, method of making and detergent composition.

  18. A generally applicable sequential alkaline phosphatase immunohistochemical double staining

    NARCIS (Netherlands)

    van der Loos, Chris M.; Teeling, Peter

    2008-01-01

    A universal type of sequential double alkaline phosphatase immunohistochemical staining is described that can be used for formalin-fixed, paraffin-embedded and cryostat tissue sections from human and mouse origin. It consists of two alkaline phosphatase detection systems including enzymatic

  19. Increased river alkalinization in the Eastern U.S.

    Science.gov (United States)

    Kaushal, Sujay S; Likens, Gene E; Utz, Ryan M; Pace, Michael L; Grese, Melissa; Yepsen, Metthea

    2013-09-17

    The interaction between human activities and watershed geology is accelerating long-term changes in the carbon cycle of rivers. We evaluated changes in bicarbonate alkalinity, a product of chemical weathering, and tested for long-term trends at 97 sites in the eastern United States draining over 260,000 km(2). We observed statistically significant increasing trends in alkalinity at 62 of the 97 sites, while remaining sites exhibited no significant decreasing trends. Over 50% of study sites also had statistically significant increasing trends in concentrations of calcium (another product of chemical weathering) where data were available. River alkalinization rates were significantly related to watershed carbonate lithology, acid deposition, and topography. These three variables explained ~40% of variation in river alkalinization rates. The strongest predictor of river alkalinization rates was carbonate lithology. The most rapid rates of river alkalinization occurred at sites with highest inputs of acid deposition and highest elevation. The rise of alkalinity in many rivers throughout the Eastern U.S. suggests human-accelerated chemical weathering, in addition to previously documented impacts of mining and land use. Increased river alkalinization has major environmental implications including impacts on water hardness and salinization of drinking water, alterations of air-water exchange of CO2, coastal ocean acidification, and the influence of bicarbonate availability on primary production.

  20. Increasing the alkaline protease activity of Bacillus cereus and ...

    African Journals Online (AJOL)

    User

    2011-05-09

    May 9, 2011 ... cereus and Bacillus polymyxa simultaneously with the start of sporulation phase as a ... microbial forms to inactivation by chemical or physical agents. .... alkaline pH, 9, 10 and 11 and the pH of the culture media was optimized with .... incubation temperature for alkaline protease production by Bacillus ...

  1. Production of alkaline protease by Teredinobacter turnirae cells ...

    African Journals Online (AJOL)

    The conditions for immobilizing the new alkaline protease-producing bacteria strain Teredinobacter turnirae by entrapment in calcium alginate gel were investigated. The influence of alginate concentration (20, 25 and 30 g/l) and initial cell loading (ICL) on enzyme production were studied. The production of alkaline ...

  2. Production of alkaline proteases by alkalophilic Bacillus subtilis ...

    African Journals Online (AJOL)

    Tuoyo Aghomotsegin

    2016-11-23

    Nov 23, 2016 ... A new strain of Bacillus sp. was isolated from alkaline soil, which was able to produce extracellular alkaline ... rice and dates (Khosravi-Darani et al., 2008), protein by- products from lather ..... Pigeon pea waste as a novel ...

  3. Comparative Detection of Alkaline Protease Production in Exiguobacterium acetylicum

    International Nuclear Information System (INIS)

    Gomaa, O.M.; EI Shafey, H.M.

    2009-01-01

    Alkaline protease is one of the most important enzymes in industry, medicine, and research. In the present work, a comparative detection for alkaline protease activity was established for instant detection of enzyme activity. Eight different alkalophilic bacterial isolates were compared based on the clear zone they produced on skim milk agar. One strain gave an absolute clear zone in 16 hours and was used for alkaline protease detection. The result of Phenotypic identification using Biology Microlog 3 identified the isolate as Exiguobacterium acetylicum. The isolate under study showed slightly different characteristics from a known Exiguobacterium acetylicum strain. The isolate tolerated alkaline conditions up to ph 11, while good growth was evident at ph 7, the maximum alkaline protease activity was observed at ph 9 which reached up to 109.01 U/ml. The alkaline activity assay using alkaline protease enzyme assay were coordinating with those obtained by conductivity; there was a relevant decrease in conductivity at the maximum increase in enzyme activity, which proved the cell membrane conductivity has a close relation to alkaline protease production. This isolate has tolerated gamma radiation, the increase in dose (up to 4 Gy) gave wider clear zones in terms of diameter and this was relevant to the conductivity measurements

  4. Partial purification and characterization of alkaline proteases from ...

    African Journals Online (AJOL)

    Alkaline proteases from the digestive tract of anchovy were partially purified by ammonium sulfate fractionation, dialysis and Sephadex G-75 gel filtration. The purification fold and yield were 6.23 and 4.49%, respectively. The optimum activities of partially purified alkaline proteases were observed at 60°C and at pH 11.0.

  5. Optimization of alkaline protease production from Pseudomonas ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-12-15

    Dec 15, 2009 ... protease production was 37°C at pH 9, with 2% inoculum in the medium for 24 h. .... Positive. Catalase test. Positive ... The enzyme activity gradually decreases from ... Effect of temperature on protease production by Pseudomonas fluorescens. 0 .... between RNA polymerase and upstream promotes DNA.

  6. Geochemical aspects of alkaline massif of Banhadao, PR, Brazil

    International Nuclear Information System (INIS)

    Ruberti, E.; Gomes, C.B.; Dutra, C.V.

    1987-01-01

    The alkaline massif of Banhadao, located near Cerro Azul, State of Parana, southern Brazil, occupies an area of about 8 Km 2 and is constituted by three magnetic associations: a group of mesocratic to leucocratic coarse nepheline syenites (NeS) (melanite NeS, NeS I, and light reddish and grey varieties of NeS II); a second group of medium to fine-grained ultrabasic to basic rocks (phlogopite melteigites and petrologically related malignites and feldspar-melanite ijolites); and a group of fine-grained to aphanitic phonolotic dikes, cutting NeS. The rocks of the complex are miaskitic, showing low concentrations of trace elements (V, Th and mainly REE), lack of rare metal silicates, and relative abundance of apatite and sphene. NeS are distinguished by a differentiation trend in which highly differentiated end members are enriched in alkalis and Al 2 O 3 , with decrease in MgO, FeO (total), CaO and TiO 2 . The less differentiated melanite-rich rocks show higher concentrations in Zr, Nb, Y and V. Phlogopite melteigites and associated rocks show the highest contents of MgO, FeO (total), CaO and TiO 2 , and the lowest concentration of alkalis and Al 2 O 3 ; they are significantly enriched in Ba and are the only rocks with detectable amounts of Ni, Cu and Cr. The phonolites are chemically similar to NeS. The Banhadao rocks were probably formed during successive intrusions of two different magmas types. The source of NeS and phonolites was probably a nephelinitic magma, while phlogopite melteigites and related rocks were probably derived from an alkali-enriched ferromagnesian magna. Both parent magmas probably derived by melting of rocks of the lower crust or upper mantle. (author) [pt

  7. Ethanol production from bamboo using mild alkaline pre-extraction followed by alkaline hydrogen peroxide pretreatment.

    Science.gov (United States)

    Yuan, Zhaoyang; Wen, Yangbing; Kapu, Nuwan Sella

    2018-01-01

    A sequential two-stage pretreatment process comprising alkaline pre-extraction and alkaline hydrogen peroxide pretreatment (AHP) was investigated to convert bamboo carbohydrates into bioethanol. The results showed that mild alkaline pre-extraction using 8% (w/w) sodium hydroxide (NaOH) at 100°C for 180min followed by AHP pretreatment with 4% (w/w) hydrogen peroxide (H 2 O 2 ) was sufficient to generate a substrate that could be efficiently digested with low enzyme loadings. Moreover, alkali pre-extraction enabled the use of lower H 2 O 2 charges in AHP treatment. Two-stage pretreatment followed by enzymatic hydrolysis with only 9FPU/g cellulose led to the recovery of 87% of the original sugars in the raw feedstock. The use of the pentose-hexose fermenting Saccharomyces cerevisiae SR8u strain enabled the utilization of 95.7% sugars in the hydrolysate to reach 4.6%w/v ethanol titer. The overall process also enabled the recovery of 62.9% lignin and 93.8% silica at high levels of purity. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. The effect of irrigated rice cropping on the alkalinity of two alkaline rice soils in the Sahel

    NARCIS (Netherlands)

    Asten, van P.J.A.; Zelfde, van 't J.A.; Zee, van der S.E.A.T.M.; Hammecker, C.

    2004-01-01

    Irrigated rice cropping is practiced to reclaim alkaline-sodic soils in many parts of the world. This practice is in apparent contrast with earlier studies in the Sahel, which suggests that irrigated rice cropping may lead to the formation of alkaline-sodic soils. Soil column experiments were done

  9. Production and characterization of thermostable alkaline protease of Bacillus subtilis (ATCC 6633) from optimized solid-state fermentation.

    Science.gov (United States)

    Chatterjee, Joyee; Giri, Sudipta; Maity, Sujan; Sinha, Ankan; Ranjan, Ashish; Rajshekhar; Gupta, Suvroma

    2015-01-01

    Proteases are the most important group of enzymes utilized commercially in various arenas of industries, such as food, detergent, leather, dairy, pharmaceutical, diagnostics, and waste management, accounting for nearly 20% of the world enzyme market. Microorganisms of specially Bacillus genera serve as a vast repository of diverse set of industrially important enzymes and utilized for the large-scale enzyme production using a fermentation technology. Approximately 30%-40% of the cost of industrial enzymes originates from the cost of the growth medium. This study is attempted to produce protease from Bacillus subtilis (ATCC 6633) after optimization of various process parameters with the aid of solid-state fermentation using a cheap nutrient source such as wheat bran. B. subtilis (ATCC 6633) produces proteases of molecular weight 36 and 20 kDa, respectively, in the fermented medium as evident from SDS zymogram. Alkaline protease activity has been detected with optimum temperature at 50 °C and is insensitive to ethylenediaminetetraacetic acid. This thermostable alkaline protease exhibits dual pH optimum at 7 and 10 with moderate pH stability at alkaline pH range. It preserves its activity in the presence of detergent such as SDS, Tween 20, and Triton X-100 and may be considered as an effective additive to detergent formulation with some industrial importance. © 2014 International Union of Biochemistry and Molecular Biology, Inc.

  10. Changes in Expression of Connexin 32, Bile Canaliculus-Like Structures, and Localization of Alkaline Phosphatase in Primary Cultures of Fetal Rat Hepatocytes

    International Nuclear Information System (INIS)

    Fukazawa, Shoko; Chida, Kohsuke; Taguchi, Meiko; Takeuchi, Akihiro; Ikeda, Noriaki

    2013-01-01

    We devised an experimental design in primary cultures of fetal rat hepatocytes for studying hepatocyte differentiation over a short period. In the present study, hepatocytes were first cultured for 3 days in dexamethasone-supplemented medium and then for an additional 3 days in dexamethasone- or epidermal growth factor-supplemented medium. In hepatocytes cultured continuously in dexamethasone-supplemented medium, the expression of connexin 32 increased and bile canaliculus-like structures and localization of alkaline phosphatase in the plasma membrane around bile canaliculus-like structures were maintained. Few cells incorporated bromodeoxyuridine. On the other hand, in most of the hepatocytes cultured in epidermal growth factor-supplemented medium, the expression of connexin 32 was minimally recognized, bile canaliculus-like structures were shortened or eliminated, and alkaline phosphatase was localized as numerous fine spots throughout the cytoplasm. More than 20% of all hepatocytes incorporated bromodeoxyuridine. The present study suggests that in hepatocytes, there is a close relationship among connexin 32 expression, the maintenance of bile canaliculus-like structures, and the localization of alkaline phosphatase to the plasma membrane around the bile canaliculus-like structures, and this indicates that the present experimental model is useful for studying hepatocyte differentiation over a short period

  11. pH regulation of recombinant glucoamylase production in Fusarium venenatum JeRS 325, a transformant with a Fusarium oxysporum alkaline (trypsin-like) protease promoter.

    Science.gov (United States)

    Wiebe, M G; Robson, G D; Shuster, J R; Trinci, A P

    1999-08-05

    Fusarium venenatum (formerly Fusarium graminearum) JeRS 325 produces heterologous glucoamylase (GAM) under the regulation of a Fusarium oxysporum alkaline (trypsin-like) protease promoter. The glucoamylase gene was used as a reporter gene to study the effects of ammonium and pH on GAM production under the control of the alkaline protease promoter. Between pH 4.0 and 5.8, GAM production in glucose-limited chemostat cultures of JeRS 325 grown at a dilution rate of 0.10 h-1 (doubling time, 6.9 h) on (NH4)2SO4 medium increased in a linear manner with increase in pH. However, at pH 4.0 and below GAM production was almost completely repressed in glucose-limited chemostat cultures grown on (NH4)2SO4 or NaNO3 medium. Thus GAM production in JeRS 325 is regulated by culture pH, not by the nature of the nitrogen source in the medium. The difficulty of using unbuffered medium when investigating putative ammonium repression is also shown. The study demonstrates the potential for use of the alkaline protease promoter in F. graminearum for the production of recombinant proteins in a pH dependent man ner. Copyright 1999 John Wiley & Sons, Inc.

  12. 2nd Generation alkaline electrolysis. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Yde, L. [Aarhus Univ. Business and Social Science - Centre for Energy Technologies (CET), Aarhus (Denmark); Kjartansdottir, C.K. [Technical Univ. of Denmark. DTU Mechanical Engineering, Kgs. Lyngby (Denmark); Allebrod, F. [Technical Univ. of Denmark. DTU Energy Conversion, DTU Risoe Campus, Roskilde (Denmark)] [and others

    2013-03-15

    The overall purpose of this project has been to contribute to this load management by developing a 2{sup nd} generation of alkaline electrolysis system characterized by being compact, reliable, inexpensive and energy efficient. The specific targets for the project have been to: 1) Increase cell efficiency to more than 88% (according to the higher heating value (HHV)) at a current density of 200 mA /cm{sup 2}; 2) Increase operation temperature to more than 100 degree Celsius to make the cooling energy more valuable; 3) Obtain an operation pressure more than 30 bar hereby minimizing the need for further compression of hydrogen for storage; 4) Improve stack architecture decreasing the price of the stack with at least 50%; 5) Develop a modular design making it easy to customize plants in the size from 20 to 200 kW; 6) Demonstrating a 20 kW 2{sup nd} generation stack in H2College at the campus of Arhus University in Herning. The project has included research and development on three different technology tracks of electrodes; an electrochemical plating, an atmospheric plasma spray (APS) and finally a high temperature and pressure (HTP) track with operating temperature around 250 deg. C and pressure around 40 bar. The results show that all three electrode tracks have reached high energy efficiencies. In the electrochemical plating track a stack efficiency of 86.5% at a current density of 177mA/cm{sup 2} and a temperature of 74.4 deg. C has been shown. The APS track showed cell efficiencies of 97%, however, coatings for the anode side still need to be developed. The HTP cell has reached 100 % electric efficiency operating at 1.5 V (the thermoneutral voltage) with a current density of 1. 1 A/cm{sup 2}. This track only tested small cells in an externally heated laboratory set-up, and thus the thermal loss to surroundings cannot be given. The goal set for the 2{sup nd} generation electrolyser system, has been to generate 30 bar pressure in the cell stack. An obstacle to be

  13. Alkaline fuel cell with nitride membrane

    Science.gov (United States)

    Sun, Shen-Huei; Pilaski, Moritz; Wartmann, Jens; Letzkus, Florian; Funke, Benedikt; Dura, Georg; Heinzel, Angelika

    2017-06-01

    The aim of this work is to fabricate patterned nitride membranes with Si-MEMS-technology as a platform to build up new membrane-electrode-assemblies (MEA) for alkaline fuel cell applications. Two 6-inch wafer processes based on chemical vapor deposition (CVD) were developed for the fabrication of separated nitride membranes with a nitride thickness up to 1 μm. The mechanical stability of the perforated nitride membrane has been adjusted in both processes either by embedding of subsequent ion implantation step or by optimizing the deposition process parameters. A nearly 100% yield of separated membranes of each deposition process was achieved with layer thickness from 150 nm to 1 μm and micro-channel pattern width of 1μm at a pitch of 3 μm. The process for membrane coating with electrolyte materials could be verified to build up MEA. Uniform membrane coating with channel filling was achieved after the optimization of speed controlled dip-coating method and the selection of dimethylsulfoxide (DMSO) as electrolyte solvent. Finally, silver as conductive material was defined for printing a conductive layer onto the MEA by Ink-Technology. With the established IR-thermography setup, characterizations of MEAs in terms of catalytic conversion were performed successfully. The results of this work show promise for build up a platform on wafer-level for high throughput experiments.

  14. Reduction of proteinuria through podocyte alkalinization.

    Science.gov (United States)

    Altintas, Mehmet M; Moriwaki, Kumiko; Wei, Changli; Möller, Clemens C; Flesche, Jan; Li, Jing; Yaddanapudi, Suma; Faridi, Mohd Hafeez; Gödel, Markus; Huber, Tobias B; Preston, Richard A; Jiang, Jean X; Kerjaschki, Dontscho; Sever, Sanja; Reiser, Jochen

    2014-06-20

    Podocytes are highly differentiated cells and critical elements for the filtration barrier of the kidney. Loss of their foot process (FP) architecture (FP effacement) results in urinary protein loss. Here we show a novel role for the neutral amino acid glutamine in structural and functional regulation of the kidney filtration barrier. Metabolic flux analysis of cultured podocytes using genetic, toxic, and immunologic injury models identified increased glutamine utilization pathways. We show that glutamine uptake is increased in diseased podocytes to couple nutrient support to increased demand during the disease state of FP effacement. This feature can be utilized to transport increased amounts of glutamine into damaged podocytes. The availability of glutamine determines the regulation of podocyte intracellular pH (pHi). Podocyte alkalinization reduces cytosolic cathepsin L protease activity and protects the podocyte cytoskeleton. Podocyte glutamine supplementation reduces proteinuria in LPS-treated mice, whereas acidification increases glomerular injury. In summary, our data provide a metabolic opportunity to combat urinary protein loss through modulation of podocyte amino acid utilization and pHi. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  15. Alkaline phosphatase activity of rumen bacteria.

    Science.gov (United States)

    Cheng, K J; Costerton, J W

    1977-11-01

    Of the 54 strains of rumen bacteria examined for alkaline phosphatase (APase) production, 9 of 33 gram-negative strains and none of 21 gram-positive strains produced the enzyme. The APase of the cells of the three strains of Bacteroides ruminicola that produced significant amounts of the enzyme was located in the periplasmic area of the cell envelope, whereas the enzyme was located in the strains of Selenomonas ruminantium and Succinivibrio dextrinosolvens was associated with the outer membrane. The localization of APase production in the cells of natural populations of rumen bacteria from hay-fed sheep was accomplished by reaction product deposition, and both the proportion of APase-producing bacteria and the location of the enzyme in the cell envelope of the producing cells could be determined. We suggest that this procedure is useful in detecting shifts in the bacterial population and the release of cell-bound APase that accompany feedlot bloat and other sequelae of dietary manipulation in ruminants.

  16. Identification of human pulmonary alkaline phosphatase isoenzymes.

    Science.gov (United States)

    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.

  17. Response of Desulfovibrio vulgaris to Alkaline Stress

    Energy Technology Data Exchange (ETDEWEB)

    Stolyar, S.; He, Q.; He, Z.; Yang, Z.; Borglin, S.E.; Joyner, D.; Huang, K.; Alm, E.; Hazen, T.C.; Zhou, J.; Wall, J.D.; Arkin, A.P.; Stahl, D.A.

    2007-11-30

    The response of exponentially growing Desulfovibrio vulgarisHildenborough to pH 10 stress was studied using oligonucleotidemicroarrays and a study set of mutants with genes suggested by microarraydata to be involved in the alkaline stress response deleted. The datashowed that the response of D. vulgaris to increased pH is generallysimilar to that of Escherichia coli but is apparently controlled byunique regulatory circuits since the alternative sigma factors (sigma Sand sigma E) contributing to this stress response in E. coli appear to beabsent in D. vulgaris. Genes previously reported to be up-regulated in E.coli were up-regulated in D. vulgaris; these genes included three ATPasegenes and a tryptophan synthase gene. Transcription of chaperone andprotease genes (encoding ATP-dependent Clp and La proteases and DnaK) wasalso elevated in D. vulgaris. As in E. coli, genes involved in flagellumsynthesis were down-regulated. The transcriptional data also identifiedregulators, distinct from sigma S and sigma E, that are likely part of aD. vulgaris Hildenborough-specific stress response system.Characterization of a study set of mutants with genes implicated inalkaline stress response deleted confirmed that there was protectiveinvolvement of the sodium/proton antiporter NhaC-2, tryptophanase A, andtwo putative regulators/histidine kinases (DVU0331 andDVU2580).

  18. Solubility of pllutonium in alkaline salt solutions

    International Nuclear Information System (INIS)

    Hobbs, D.T.; Edwards, T.B.

    1993-01-01

    Plutonium solubility data from several studies have been evaluated. For each data set, a predictive model has been developed where appropriate. In addition, a statistical model and corresponding prediction intervals for plutonium solubility as a quadratic function of the hydroxide concentration have been developed. Because of the wide range of solution compositions, the solubility of plutonium can vary by as much as three orders of magnitude for any given hydroxide concentration and still remain within the prediction interval. Any nuclear safety assessments that depend on the maximum amount of plutonium dissolved in alkaline salt solutions should use concentrations at least as great as the upper prediction limits developed in this study. To increase the confidence in the prediction model, it is recommended that additional solubility tests be conducted at low hydroxide concentrations and with all of the other solution components involved. To validate the model for application to actual waste solutions, it is recommended that the plutonium solubilities in actual waste solutions be determined and compared to the values predicted by the quadratic model

  19. Alkaline Materials and Regenerative Endodontics: A Review

    Directory of Open Access Journals (Sweden)

    Bill Kahler

    2017-12-01

    Full Text Available Periapical health is the primary goal of endodontic treatment in mature and immature teeth. In addition, the goals of treatment of immature teeth with arrested root development include root growth to length and maturation of the apex, as well as thickening of the canal wall. These goals are valid for immature teeth that have been subjected to trauma and dental caries or that are the result of developmental anomalies that expose the tooth to the risk of pulp necrosis and consequently result in the cessation of root maturation. Regenerative endodontic procedures (REPs have been described as a “paradigm shift” in the treatment of immature teeth with pulp necrosis and underdeveloped roots, as there is the potential for further root maturation and return of vitality. Treatment with REPs is advocated as the treatment of choice for immature teeth with pulp necrosis. REP protocols involve the use of alkaline biomaterials, primarily sodium hypochlorite, calcium hydroxide, mineral trioxide aggregates and Biodentine, and are the essential components of a successful treatment regimen.

  20. Alkaline Phosphatase, an Unconventional Immune Protein

    Directory of Open Access Journals (Sweden)

    Bethany A. Rader

    2017-08-01

    Full Text Available Recent years have seen an increase in the number of studies focusing on alkaline phosphatases (APs, revealing an expanding complexity of function of these enzymes. Of the four human AP (hAP proteins, most is known about tissue non-specific AP (TNAP and intestinal AP (IAP. This review highlights current understanding of TNAP and IAP in relation to human health and disease. TNAP plays a role in multiple processes, including bone mineralization, vitamin B6 metabolism, and neurogenesis, is the genetic cause of hypophosphatasia, influences inflammation through regulation of purinergic signaling, and has been implicated in Alzheimer’s disease. IAP regulates fatty acid absorption and has been implicated in the regulation of diet-induced obesity and metabolic syndrome. IAP and TNAP can dephosphorylate bacterial-derived lipopolysaccharide, and IAP has been identified as a potential regulator of the composition of the intestinal microbiome, an evolutionarily conserved function. Endogenous and recombinant bovine APs and recombinant hAPs are currently being explored for their potential as pharmacological agents to treat AP-associated diseases and mitigate multiple sources of inflammation. Continued research on these versatile proteins will undoubtedly provide insight into human pathophysiology, biochemistry, and the human holobiont.

  1. The aluminum chemistry and corrosion in alkaline solutions

    International Nuclear Information System (INIS)

    Zhang Jinsuo; Klasky, Marc; Letellier, Bruce C.

    2009-01-01

    Aluminum-alkaline solution systems are very common in engineering applications including nuclear engineering. Consequently, a thorough knowledge of the chemistry of aluminum and susceptibility to corrosion in alkaline solutions is reviewed. The aluminum corrosion mechanism and corrosion rate are examined based on current experimental data. A review of the phase transitions with aging time and change of environment is also performed. Particular attention is given to effect of organic and inorganic ions. As an example, the effect of boron is examined in detail because of the application in nuclear reactor power systems. Methods on how to reduce the corrosion rate of aluminum in alkaline solutions are also highlighted

  2. Mesons in the nuclear Medium

    CERN Document Server

    Kotulla, M

    2006-01-01

    We discuss recent experimental results on the modification of hadron properties in a nuclear medium. Particular emphasis is placed on an $\\omega$ production experiment performed by the CBELSA/TAPS collaboration at the ELSA accelerator. The data shows a smaller $\\omega$ meson mass together with a significant increase of its width in the nuclear medium.

  3. Petrogenesis of Karamaili alkaline A-type granites from East Junggar, Xinjiang (NW China) and their relationship with tin mineralization

    International Nuclear Information System (INIS)

    Su Yuping; Tang Hongfeng; Liu Congqiang; Hou Guangshun; Cong Feng; Sylvester, Paul J.; Qu Wenjun

    2007-01-01

    Several types of granites including alkaline granites and alkali feldspar granites are distributed in the Karamaili tectonic belt of East Junggar, Xinjiang, China. Some medium-small tin deposits are located within or near the contact zones of the granitic intrusions. The alkaline granites share all the features commonly observed in peralkaline A-type granites. They contain alkalic mafic minerals such as riebeckite and aegirine; have high contents of SiO 2 , alkalis, Rb, Th, Zr, Hf, REE (except Eu), and high ratios of FeO/MgO and Ga/Al; and show strong depletions in Ba, Sr, Eu in the spidergrams. Laser ablation-ICPMS U-Pb zircon geochronology indicates a crystallization age of ca. 305 Ma for the granites; TIMS analyses of the granites found high ε Nd (T) values of +5.9 to +6.5. Considering their geochemical features, alkaline granites most likely formed by fractional crystallization of graodioritic magmas, which were probably produced by partial melting of lower crustal basaltic to andesitic rocks formed from oceanic crustal materials that were deeply buried during late Palezoic subduction and accretion. Six molybdenite samples from the Sareshike tin deposit in East Junggar yielded an isochron age of 307±11 Ma (2σ) and a weighted mean model age of 306.5±3.4 Ma, consistent with zircon U-Pb ages of the alkaline granites. Low Re contents (0.323-0.961 ppm) in the molybdenite suggest that they originated from crustal sources related to the alkaline granites. Considering their identical ages, close spatial distribution, and similar sources, we argue that the A-type granites have a genetic relationship with the tin mineralization, and that the same association may be important elsewhere. (author)

  4. Microbial alkaline proteases: Optimization of production parameters and their properties

    Directory of Open Access Journals (Sweden)

    Kanupriya Miglani Sharma

    2017-06-01

    Full Text Available Proteases are hydrolytic enzymes capable of degrading proteins into small peptides and amino acids. They account for nearly 60% of the total industrial enzyme market. Proteases are extensively exploited commercially, in food, pharmaceutical, leather and detergent industry. Given their potential use, there has been renewed interest in the discovery of proteases with novel properties and a constant thrust to optimize the enzyme production. This review summarizes a fraction of the enormous reports available on various aspects of alkaline proteases. Diverse sources for isolation of alkaline protease producing microorganisms are reported. The various nutritional and environmental parameters affecting the production of alkaline proteases in submerged and solid state fermentation are described. The enzymatic and physicochemical properties of alkaline proteases from several microorganisms are discussed which can help to identify enzymes with high activity and stability over extreme pH and temperature, so that they can be developed for industrial applications.

  5. Spectroscopic characterization of manganese-doped alkaline earth ...

    Indian Academy of Sciences (India)

    The shapes of spectra are also changed with varying alkaline earth ions content. ... of manganese ion and electrical properties of glass contain- ing mobile ions like .... octahedral crystal field are located above the ground 6S state. Figure 2.

  6. Optimization of alkaline protease production and its fibrinolytic ...

    African Journals Online (AJOL)

    Optimization of alkaline protease production and its fibrinolytic activity from the ... nitrogen sources and sodium chloride concentration for protease production by the ... exploited to assist in protein degradation in various industrial processes.

  7. The Estimation Formation Alkaline In The Proses Desalination MSF

    International Nuclear Information System (INIS)

    Latiffah, Siti Nurul

    2000-01-01

    Already to go on estimation phenomena formation alkaline scale of a seawater. In desalination system seawater on MSF to go on scale by a thermal decomposition HCO sub.3- ion and hydrolysis carbonate ion with water on the temperature operation. The varieties alkaline scale in attached on tube surface, while reduced efficiency heat transfer and to raise corrosion attack to structure material is caused all this high cost. Estimation to take please which a sum step by step decomposition ion bicarbonate from then information scale which carbonate and hydroxyl ion. The various scale maximal is alkaline form is a calcium carbonate = 116,5 gram per meter cubic the various sedimentation is alkaline and magnesium hydroxide = 67,57 gram per meter cubic

  8. Economic Analysis of Improved Alkaline Water Electrolysis

    International Nuclear Information System (INIS)

    Kuckshinrichs, Wilhelm; Ketelaer, Thomas; Koj, Jan Christian

    2017-01-01

    Alkaline water electrolysis (AWE) is a mature hydrogen production technology and there exists a range of economic assessments for available technologies. For advanced AWEs, which may be based on novel polymer-based membrane concepts, it is of prime importance that development comes along with new configurations and technical and economic key process parameters for AWE that might be of interest for further economic assessments. This paper presents an advanced AWE technology referring to three different sites in Europe (Germany, Austria, and Spain). The focus is on financial metrics, the projection of key performance parameters of advanced AWEs, and further financial and tax parameters. For financial analysis from an investor’s (business) perspective, a comprehensive assessment of a technology not only comprises cost analysis but also further financial analysis quantifying attractiveness and supply/market flexibility. Therefore, based on cash flow (CF) analysis, a comprehensible set of metrics may comprise levelised cost of energy or, respectively, levelized cost of hydrogen (LCH) for cost assessment, net present value (NPV) for attractiveness analysis, and variable cost (VC) for analysis of market flexibility. The German AWE site turns out to perform best in all three financial metrics (LCH, NPV, and VC). Though there are slight differences in investment cost and operation and maintenance cost projections for the three sites, the major cost impact is due to the electricity cost. Although investment cost is slightly lower and labor cost is significantly lower in Spain, the difference can not outweigh the higher electricity cost compared to Germany. Given the assumption that the electrolysis operators are customers directly and actively participating in power markets, and based on the regulatory framework in the three countries, in this special case electricity cost in Germany is lowest. However, as electricity cost is profoundly influenced by political decisions as

  9. Basic study of alkaline water electrolysis

    International Nuclear Information System (INIS)

    Manabe, A.; Kashiwase, M.; Hashimoto, T.; Hayashida, T.; Kato, A.; Hirao, K.; Shimomura, I.; Nagashima, I.

    2013-01-01

    In order to realize future hydrogen society, hydrogen production systems must meet the large demand of hydrogen usage. Alkaline water electrolysis (AWE) would be one of the candidate technologies to produce hydrogen on a large scale from renewable energy. We have conducted basic research into AWE, trying to reveal technical issues under zero gap system in new cell technology. The zero gap system contributes lower cell voltage without causing any major operating problems compared with conventional finite gap cell. However, it was observed that Ni base electrodes showed corrosion phenomena in a number of test trials including steady operating conditions and several shut-downs. Activated Raney Ni alloy coating for anode material had an advantage for oxygen overvoltage. It showed a saving of around 100 mV at 40 A/dm 2 (0.4 A/cm 2 ) against Ni bare anodes. In the Chlor–Alkali (C/A) industry, thermal decomposition coating of mixed noble metal on Ni substrate is commonly used for advanced activated cathodes. It showed very low hydrogen over-potential of around 100 mV in AWE. To achieve better cell performance, separator selection is very important. We evaluated several separators including ion exchange membrane (IEM) to understand the basic function in AWE. IEM for C/A electrolysis showed high cell voltage (over 2.2 V) but low O 2 impurity in H 2 gas. Hydrogen purity was over 99.95%. Porous separators made of polypropylene showed 1.76 V at 40 A/dm 2 (0.4 A/cm 2 ), 80 °C. But there was a weakness on the durability for continuous operation. Proper selection of separator is important in an actual plant for effective and safe cell operation. The concept of safety operation is referred to by diffusion coefficient of hydrogen

  10. Photovoltaic hydrogen production with commercial alkaline electrolysers

    Energy Technology Data Exchange (ETDEWEB)

    Ursua, A.; Lopez, J.; Gubia, E.; Marroyo, L.; Sanchis, P. [Public Univ. of Navarra, Pamplona (Spain). Dept. of Electric and Electronic Engineering

    2010-07-01

    Renewable energy sources and Electrolysis generate the so-called green Hydrogen, a zero-emission and potentially fossil fuel independent energy source. However, the inherent variability of the renewable energy sources implies a mode of operation for which most current electrolysers have not been designed. This paper analyses the operation of a water electrolyser fed with photovoltaic (PV) generator electric profile. The system, Integrated by a 1 Nm{sup 3}/h Hydrogenics alkaline electrolyser and a 5100 W PV generator with 60 BP585 modules, is installed at the Public University of Navarra (Spain). The PV generator profile fed to the electrolyser is emulated by a custom-made apparatus designed and built by the authors of this paper. The profile is designed according to real irradiance data measured by a calibration cell. The irradiance data are converted to the electric power profile that the PV generator would have delivered in case of having been connected to the electrolyser by means of a DC/DC converter with maximum power point tracking (MPPT). Finally, from previously measured power-current electrolyser characteristic curves, the current profile to be delivered to the electrolyser is obtained and programmed to the electronic device. The electrolyser was tested for two types of days. During the first day, the irradiance was very stable, whereas during the second day, the irradiance was very variable. The experimental results show an average power consumption rate and an efficiency of 4908 Wh/Nm{sup 3} and 72.1%, on the first day, and 4842 Wh/Nm{sup 3} and 73.3% on the second day. The electrolyser performance was particularly good in spite of the high variability of the electric supply of the second day. (orig.)

  11. Alkaline Peroxide Delignification of Corn Stover

    Energy Technology Data Exchange (ETDEWEB)

    Mittal, Ashutosh [Biosciences; Katahira, Rui [National; Donohoe, Bryon S. [Biosciences; Black, Brenna A. [National; Pattathil, Sivakumar [Complex; Stringer, Jack M. [National; Beckham, Gregg T. [National

    2017-05-30

    Selective biomass fractionation into carbohydrates and lignin is a key challenge in the conversion of lignocellulosic biomass to fuels and chemicals. In the present study, alkaline hydrogen peroxide (AHP) pretreatment was investigated to fractionate lignin from polysaccharides in corn stover (CS), with a particular emphasis on the fate of the lignin for subsequent valorization. The influence of peroxide loading on delignification during AHP pretreatment was examined over the range of 30-500 mg H2O2/g dry CS at 50 degrees C for 3 h. Mass balances were conducted on the solid and liquid fractions generated after pretreatment for each of the three primary components, lignin, hemicellulose, and cellulose. AHP pretreatment at 250 mg H2O2/g dry CS resulted in the pretreated solids with more than 80% delignification consequently enriching the carbohydrate fraction to >90%. Two-dimensional nuclear magnetic resonance (2D-NMR) spectroscopy of the AHP pretreated residue shows that, under high peroxide loadings (>250 mg H2O2/g dry CS), most of the side chain structures were oxidized and the aryl-ether bonds in lignin were partially cleaved, resulting in significant delignification of the pretreated residues. Gel permeation chromatography (GPC) analysis shows that AHP pretreatment effectively depolymerizes CS lignin into low molecular weight (LMW) lignin fragments in the aqueous fraction. Imaging of AHP pretreated residues shows a more granular texture and a clear lamellar pattern in secondary walls, indicative of layers of varying lignin removal or relocalization. Enzymatic hydrolysis of this pretreated residue at 20 mg/g of glucan resulted in 90% and 80% yields of glucose and xylose, respectively, after 120 h. Overall, AHP pretreatment is able to selectively remove more than 80% of the lignin from biomass in a form that has potential for downstream valorization processes and enriches the solid pulp into a highly digestible material.

  12. Economic Analysis of Improved Alkaline Water Electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Kuckshinrichs, Wilhelm, E-mail: w.kuckshinrichs@fz-juelich.de; Ketelaer, Thomas; Koj, Jan Christian [Forschungszentrum Juelich, Institute for Energy and Climate Research – Systems Analysis and Technology Evaluation (IEK-STE), Juelich (Germany)

    2017-02-20

    Alkaline water electrolysis (AWE) is a mature hydrogen production technology and there exists a range of economic assessments for available technologies. For advanced AWEs, which may be based on novel polymer-based membrane concepts, it is of prime importance that development comes along with new configurations and technical and economic key process parameters for AWE that might be of interest for further economic assessments. This paper presents an advanced AWE technology referring to three different sites in Europe (Germany, Austria, and Spain). The focus is on financial metrics, the projection of key performance parameters of advanced AWEs, and further financial and tax parameters. For financial analysis from an investor’s (business) perspective, a comprehensive assessment of a technology not only comprises cost analysis but also further financial analysis quantifying attractiveness and supply/market flexibility. Therefore, based on cash flow (CF) analysis, a comprehensible set of metrics may comprise levelised cost of energy or, respectively, levelized cost of hydrogen (LCH) for cost assessment, net present value (NPV) for attractiveness analysis, and variable cost (VC) for analysis of market flexibility. The German AWE site turns out to perform best in all three financial metrics (LCH, NPV, and VC). Though there are slight differences in investment cost and operation and maintenance cost projections for the three sites, the major cost impact is due to the electricity cost. Although investment cost is slightly lower and labor cost is significantly lower in Spain, the difference can not outweigh the higher electricity cost compared to Germany. Given the assumption that the electrolysis operators are customers directly and actively participating in power markets, and based on the regulatory framework in the three countries, in this special case electricity cost in Germany is lowest. However, as electricity cost is profoundly influenced by political decisions as

  13. Kinetic and Mechanistic Studies of Oxidation of an Antiallergic Drug with Bromamine-T in Acid and Alkaline Media

    International Nuclear Information System (INIS)

    Puttaswamy; Anu Sukhdev

    2012-01-01

    Cetrizine dihydrochloride (CTZH) is widely used as an anti-allergic drug. Sodium N-bromo-p-toluenesulfonamide or bromamine-T (BAT) is the bromine analogue of chloramine-T (CAT) and is found to be a better oxidizing agent than CAT. In the present research, the kinetics of oxidation of CTZH with BAT in acid and alkaline media was studied at 313 K. The experimental rate laws obtained are: -d[BAT]/dt = k[BAT] [CTZH] 0.80 [H + ] -0.48 in acid medium and -d[BAT]/dt = k[BAT][CTZH] 0.48 [OH - ] 0.52 [PTS] -0.40 in alkaline medium where PTS is p-toluenesulfonamide. Activation parameters and reaction constants were evaluated. The solvent isotope effect was studied using D 2 O. The dielectric effect is positive. The stoichiometry of the reaction was found to be 1:1 and the oxidation products were identified as 4-chlorobenzophenone and (2-piperazin-1-yl-ethoxy)-acetic acid in both media. The rate of oxidation of CTZH is faster in acid medium. Suitable mechanisms and related rate laws have been worked out

  14. Kinetic and Mechanistic Studies of Oxidation of an Antiallergic Drug with Bromamine-T in Acid and Alkaline Media

    Energy Technology Data Exchange (ETDEWEB)

    Puttaswamy; Anu Sukhdev [Bangalore Univ., Bangalore (India)

    2012-11-15

    Cetrizine dihydrochloride (CTZH) is widely used as an anti-allergic drug. Sodium N-bromo-p-toluenesulfonamide or bromamine-T (BAT) is the bromine analogue of chloramine-T (CAT) and is found to be a better oxidizing agent than CAT. In the present research, the kinetics of oxidation of CTZH with BAT in acid and alkaline media was studied at 313 K. The experimental rate laws obtained are: -d[BAT]/dt = k[BAT] [CTZH]{sup 0.80}[H{sup +}]{sup -0.48} in acid medium and -d[BAT]/dt = k[BAT][CTZH]{sup 0.48}[OH{sup -}]{sup 0.52}[PTS]{sup -0.40} in alkaline medium where PTS is p-toluenesulfonamide. Activation parameters and reaction constants were evaluated. The solvent isotope effect was studied using D{sub 2}O. The dielectric effect is positive. The stoichiometry of the reaction was found to be 1:1 and the oxidation products were identified as 4-chlorobenzophenone and (2-piperazin-1-yl-ethoxy)-acetic acid in both media. The rate of oxidation of CTZH is faster in acid medium. Suitable mechanisms and related rate laws have been worked out.

  15. Net alkalinity and net acidity 1: Theoretical considerations

    International Nuclear Information System (INIS)

    Kirby, Carl S.; Cravotta, Charles 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, CO 2 , 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 CO 2 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 mgL -1 as CaCO 3 (based on pH and analytical concentrations of dissolved Fe II , Fe III , Mn, and Al in mgL -1 ):acidity calculated =50{1000(10 -pH )+[2(Fe II )+3(Fe III )]/56+2(Mn) /55+3(Al)/27}underestimates contributions from HSO 4 - and H + , but overestimates the acidity due to Fe 3+ and Al 3+ . 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

  16. Net alkalinity and net acidity 1: Theoretical considerations

    Science.gov (United States)

    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

  17. One–pot synthesis and electrochemical properties of polyaniline nanofibers through simply tuning acid–base environment of reaction medium

    International Nuclear Information System (INIS)

    Li, Tao; Zhou, Yi; Liang, Banglei; Jin, Dandan; Liu, Na; Qin, Zongyi; Zhu, Meifang

    2017-01-01

    Highlights: •Presenting a facile one–pot approach to prepare polyaniline nanofibers through simply tuning acid–base environment of reaction medium. •Determining the role of aniline oligomers play in the formation of polyaniline nanofibers. •Demonstrating the feasibility of polyaniline nanofibers as high–performance electrode materials for supercapacitors. -- Abstract: A facile and efficient one–pot approach was presented to prepare polyaniline (PANi) nanofibers through simply tuning acid–base environment of reaction medium without the assistance of templates or use of organic solvents, in which aniline oligomers formed in the alkaline solution were used as “seeds” for the oriented growth of PANi chains under acidic conditions. The as–prepared PANi nanofibers were investigated by field–emission scanning electron microscopy, ultraviolet–visible spectroscopy, Fourier transform infrared spectroscopy and X–ray diffraction technology. Furthermore, the electrochemical properties were evaluated by cyclic voltammetry, galvanostatic charge–discharge test, and electrochemical impedance spectroscopy. More attentions were paid to the influence of aniline concentrations in alkaline and acidic reaction medium on the morphology, microstructure and properties of PANi nanofibers. It can be found that aniline concentration in alkaline medium has a stronger impact on the electrical and electrochemical properties of final products, however, their morphologies obviously depend on aniline concentration in acidic solution. Moreover, PANi nanofibers prepared at aniline concentrations of 48 mM in alkaline medium and 0.2 M in acidic medium exhibits the largest specific capacitance of 857.2 F g −1 at the scan rate of 5 mV s −1 , and capacitance retention of 63.8% after 500 cycles. It is demonstrated that such one–pot approach can present a low cost and environmental friendly route to fabricate PANi nanofibers in fully aqueous solution as high

  18. Processes determining the marine alkalinity and carbonate saturation distributions

    OpenAIRE

    B. R. Carter; J. R. Toggweiler; R. M. Key; J. L. Sarmiento

    2014-01-01

    We introduce a composite tracer, Alk*, that has a global distribution primarily determined by CaCO3 precipitation and dissolution. Alk* also highlights riverine alkalinity plumes that are due to dissolved calcium carbonate from land. We estimate the Arctic receives approximately twice the riverine alkalinity per unit area as the Atlantic, and 8 times that of the other oceans. Riverine inputs broadly elevate Alk* in the Arctic surface and particularly near ri...

  19. Block Copolymers for Alkaline Fuel Cell Membrane Materials

    Science.gov (United States)

    2014-07-30

    temperature fuel cells including proton exchange membrane fuel cell ( PEMFC ) and alkaline fuel cell (AFC) with operation temperature usually lower than 120...advantages over proton exchange membrane fuel cells ( PEMFCs ) resulting in the popularity of AFCs in the US space program.[8-11] The primary benefit AFC...offered over PEMFC is better electrochemical kinetics on the anode and cathode under the alkaline environment, which results in the ability to use

  20. Alkaline phosphatase-fused repebody as a new format of immuno-reagent for an immunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Hyo-Deok; Lee, Joong-jae [Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 (Korea, Republic of); Kim, Yu Jung [Industrial Biotechnology and Bioenergy Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon (Korea, Republic of); Hantschel, Oliver [School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne (Switzerland); Lee, Seung-Goo [Industrial Biotechnology and Bioenergy Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon (Korea, Republic of); Kim, Hak-Sung, E-mail: hskim76@kaist.ac.kr [Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 (Korea, Republic of)

    2017-01-15

    Enzyme-linked immunoassays based on an antibody-antigen interaction are widely used in biological and medical sciences. However, the conjugation of an enzyme to antibodies needs an additional chemical process, usually resulting in randomly cross-linked molecules and a loss of the binding affinity and enzyme activity. Herein, we present the development of an alkaline phosphatase-fused repebody as a new format of immuno-reagent for immunoassays. A repebody specifically binding to human TNF-α (hTNF-α) was selected through a phage display, and its binding affinity was increased up to 49 nM using a modular engineering approach. A monomeric alkaline phosphatase (mAP), which was previously isolated from a metagenome library, was genetically fused to the repebody as a signal generator, and the resulting repebody-mAP fusion protein was used for direct and sandwich immunoassays of hTNF-α. We demonstrate the utility and potential of the repebody-mAP fusion protein as an immuno-reagent by showing the sensitivity of 216 pg mL{sup −1} for hTNF-α in a sandwich immunoassay. Furthermore, this repebody-mAP fusion protein enabled the detection of hTNF-α spiked in a serum-supplemented medium with high accuracy and reproducibility. It is thus expected that a mAP-fused repebody can be broadly used as an immuno-reagent in immunoassays. - Highlights: • A human TNF-α (hTNF-α)-specific repebody was selected using a phage display. • A monomeric alkaline phosphatase (mAP) was genetically fused to the repebody. • mAP-fused repebody enabled detection of hTNF-α with high sensitivity and accuracy. • mAP-fused repebody can be widely used as a new immuno-reagent in immunoassays.

  1. Purification and characterization of a thermostable alkaline cellulase produced by Bacillus licheniformis 380 isolated from compost

    Directory of Open Access Journals (Sweden)

    ÉVILIN G. DE MARCO

    2017-10-01

    Full Text Available ABSTRACT During composting processes, the degradation of organic waste is accomplished and driven by a succession of microbial populations exhibiting a broad range of functional competencies. A total of 183 bacteria, isolated from a composting process, were evaluated for cellulase activity at different temperatures (37, 50, 60, and 70°C and pH values. Out of the 22 isolates that showed activity, isolate 380 showed the highest cellulase activity. Its ability to produce cellulase was evaluated in culture medium supplemented with carboxymethyl cellulose, microcrystalline cellulose, wheat straw, and rice husk. The culture medium supplemented with carboxymethyl cellulose induced higher enzyme activity after 6 hours of incubation (0.12 UEA mL-1 min-1. For wheat straw and rice husk, the results were 0.08 UEA mL-1 min-1 for both, while for microcrystalline cellulose, 0.04 UEA mL-1 min-1 were observed. The highest carboxymethyl cellulase activity was observed at 60°C (0.14 UEA mL-1 min-1 for both crude and partially purified enzyme after 30 and 120 min of incubation, respectively. Alkalinization of the medium was observed during cultivation in all substrates. The cellulase had a molecular mass of 20 kDa determined by SDS-Page. Isolate 380 was identified as Bacillus licheniformis. This work provides a basis for further studies on composting optimization.

  2. Pions in the nuclear medium

    International Nuclear Information System (INIS)

    Chanfray, G.

    1996-07-01

    We discuss various aspects of pion physics in the nuclear medium. We first study s-wave pion-nucleus interaction in connection with chiral symmetry restoration and quark condensate in the nuclear medium. We then address the question of p-wave pion-nucleus interaction and collective pionic modes in nuclei and draw the consequences for in medium ππ correlations especially in the scalar-isoscalar channel. We finally discuss the modification of the rho meson mass spectrum at finite density and/or temperature in connection with relativistic heavy ion collisions

  3. Acid transformation of bauxite residue: Conversion of its alkaline characteristics.

    Science.gov (United States)

    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. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. A differential medium for the enumeration of the spoilage yeast Zygosaccharomyces bailii in wine.

    Science.gov (United States)

    Schuller, D; Côrte-Real, M; Leão, C

    2000-11-01

    A collection of yeasts, isolated mostly from spoiled wines, was used in order to develop a differential medium for Zygosaccharomyces bailii. The 118 selected strains of 21 species differed in their origin and resistance to preservatives and belonged to the genera Pichia, Torulaspora, Dekkera, Debaryomyces, Saccharomycodes, Issatchenkia, Kluyveromyces, Kloeckera, Lodderomyces, Schizosaccharomyces, Rhodotorula, Saccharomyces, and Zygosaccharomyces. The design of the culture medium was based on the different ability of the various yeast species to grow in a mineral medium with glucose and formic acid (mixed-substrate medium) as the only carbon and energy sources and supplemented with an acid-base indicator. By manipulating the concentration of the acid and the sugar it was possible to select conditions where only Z. bailii strains gave rise to alkalinization, associated with a color change of the medium (positive response). The final composition of the mixed medium was adjusted as a compromise between the percentage of recovery and selectivity for Z. bailii. This was accomplished by the use of pure or mixed cultures of the yeast strains and applying the membrane filtration methodology. The microbiological analysis of two samples of contaminated Vinho Verde showed that the new medium can be considered as a differential medium to distinguish Z. bailii from other contaminating yeasts, having potential application in the microbiological control of wines and probably other beverages and foods.

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

    Science.gov (United States)

    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

  6. Lectin histochemistry and alkaline phosphatase activity in the pia mater vessels of spontaneously hypertensive rats (SHR).

    Science.gov (United States)

    Szumańska, G; Gadamski, R

    1992-01-01

    Some lectins were used to study the localization of sugar residues on the endothelial cell surface in the pia mater blood vessels of control (WKY) and hypertensive rats (SHR). The lectins tested recognized the following residues: beta-D-galactosyl (Ricinus communis agglutinin 120, RCA-1), alpha-L-fucosyl (Ulex europaeus agglutinin, UEA-1), N-acetylglucosaminyl and sialyl (Wheat germ agglutinin, WGA), N-glycolyl-neuraminic acid (Limax flavus agglutinin, LFA), and N-acetyl-D-galactosaminyl (Helix pomatia agglutinin, HPA). Several differences were revealed in the presence of sugar receptors on the surface of endothelial cells between the control and the hypertensive rats. Our studies showed also differences in the localization of the tested glycoconjugates between pial capillaries, small, medium-size and large pial arteries. The histochemical evaluation of alkaline phosphatase revealed an increased activity of the enzyme in the pial vessels of SHRs as compared with control rats with a similar localization of the enzyme activity. Some differences in the distribution of lectin binding sites and alkaline phosphatase activity could be associated with the different functions of particular segments of the pial vascular network.

  7. Molecular characterization of alkaline protease of Bacillus amyloliquefaciens SP1 involved in biocontrol of Fusarium oxysporum.

    Science.gov (United States)

    Guleria, Shiwani; Walia, Abhishek; Chauhan, Anjali; Shirkot, C K

    2016-09-02

    An alkaline protease gene was amplified from genomic DNA of Bacillus amyloliquefaciens SP1 which was involved in effective biocontrol of Fusarium oxysporum. We investigated the antagonistic capacity of protease of B. amyloliquifaciens SP1, under in vitro conditions. The 5.62 fold purified enzyme with specific activity of 607.69U/mg reported 24.14% growth inhibition of F. oxysporum. However, no antagonistic activity was found after addition of protease inhibitor i.e. PMSF (15mM) to purified enzyme. An 1149bp nucleotide sequence of protease gene encoded 382 amino acids of 43kDa and calculated isoelectric point of 9.29. Analysis of deduced amino acid sequence revealed high homology (86%) with subtilisin E of Bacillus subtilis. The B. amyloliquefaciens SP1 protease gene was expressed in Escherichiax coli BL21. The expressed protease was secreted into culture medium by E. coli and exhibited optimum activity at pH8.0 and 60°C. The most reliable three dimensional structure of alkaline protease was determined using Phyre 2 server which was validated on the basis of Ramachandran plot and ERRAT value. The expression and structure prediction of the enzyme offers potential value for commercial application in agriculture and industry. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Nicotine inhibits collagen synthesis and alkaline phosphatase activity, but stimulates DNA synthesis in osteoblast-like cells

    International Nuclear Information System (INIS)

    Ramp, W.K.; Lenz, L.G.; Galvin, R.J.

    1991-01-01

    Use of smokeless tobacco is associated with various oral lesions including periodontal damage and alveolar bone loss. This study was performed to test the effects of nicotine on bone-forming cells at concentrations that occur in the saliva of smokeless tobacco users. Confluent cultures of osteoblast-like cells isolated from chick embryo calvariae were incubated for 2 days with nicotine added to the culture medium (25-600 micrograms/ml). Nicotine inhibited alkaline phosphatase in the cell layer and released to the medium, whereas glycolysis (as indexed by lactate production) was unaffected or slightly elevated. The effects on medium and cell layer alkaline phosphatase were concentration dependent with maximal inhibition occurring at 600 micrograms nicotine/ml. Nicotine essentially did not affect the noncollagenous protein content of the cell layer, but did inhibit collagen synthesis (hydroxylation of [ 3 H]proline and collagenase-digestible protein) at 100, 300, and 600 micrograms/ml. Release of [ 3 H]hydroxyproline to the medium was also decreased in a dose-dependent manner, as was the collagenase-digestible protein for both the medium and cell layer. In contrast, DNA synthesis (incorporation of [ 3 H]thymidine) was more than doubled by the alkaloid, whereas total DNA content was slightly inhibited at 600 micrograms/ml, suggesting stimulated cell turnover. Morphologic changes occurred in nicotine-treated cells including rounding up, detachment, and the occurrence of numerous large vacuoles. These results suggest that steps to reduce the salivary concentration of nicotine in smokeless tobacco users might diminish damaging effects of this product on alveolar bone

  9. Alkaline protease production from industrial wastes by bacillus subtilis ML-4

    International Nuclear Information System (INIS)

    Sher, M.G.; Nadeem, M.; Syed, Q.; Irfan, M.; Baig, S.

    2010-01-01

    The influence of various culture conditions on protease production by Bacillus subtilis ML-4 was studied in the presence of growth medium containing poultry feed waste (5%), K/sub 2/HPO/sub 4/ (0.3%), CaCl/sub 2/ (0.03%) and MgSO/sub 4/ (0.015%). Maximum protease production (264.25 +- 1.86 U/ml) was observed at initial pH 9 with 3% (v/v) of inoculum size after 48 h of incubation at 37 degree C. The alkaline protease was stable over a broad range of temperature (30 to 60 degree C) and pH (8 to 11). However, maximum activity (155.45 U/ml) was observed at temperature 50 degree C and pH 10. (author)

  10. Comparative study of polypyrrole films electrosynthesized in alkaline and acid solutions

    International Nuclear Information System (INIS)

    Lehr, I.L.; Quinzani, O.V.; Saidman, S.B.

    2009-01-01

    The influence of the pH of electropolymerization solutions on the properties of polypyrrole films has been studied using potentiodynamic techniques and faradaic impedance spectroscopy. Scanning electron microscopy (SEM), IR and Raman spectroscopies, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were also used for products characterization. Results indicate that, contrary to what happen with the polymer electrogenerated in acid solutions, the films prepared in alkaline media are stable and present good electrochemical activity in basic solutions. Possible explanations for the observed differences are discussed and it is proposed that the pH of electropolymerization medium directly affects chains organization. Electrosynthesis in solutions of increased basicity results in a more compact and closed polymer structure.

  11. Ion exchange kinetics of alkaline earths on Zr(IV) arsenosilicate cation exchanger

    International Nuclear Information System (INIS)

    Varshney, K.G.; Agrawal, S.; Varshney, K.

    1984-01-01

    A new approach based on the Nernst-Planck equations was applied to study the ion exchange kinetics for the exchange reactions of Mg(II), Ca(II), Sr(II) and Ba(II) with H + -ions at various temperatures on the zirconium(IV) arsenosilicate phase. Under the conditions of particle diffusion, the rate of exchange was found to be independent of the metal ion concentration at and above 0.1 M in aqueous medium. Energy and entropy of activation were determined and found to vary linearly with the ionic radii and mobilities of alkaline earths, a unique feature observed for an inorganic ion exchanger. The results are useful for predicting the ion exchange processes occurring on the surface of an inorganic material of the type studied. (author)

  12. New alternative processes for the treatment of the alkaline solvent wash waste

    International Nuclear Information System (INIS)

    Cecille, L.; Cumming, I.W.; Gasparini, G.; Dozol, J.F.

    1986-09-01

    The separate treatment of the solvent wash alkaline waste (ASWW) from the other low and medium level liquid wastes generated during reprocessing operations has been investigated through the development of three alternative processes dealing with solvent extraction, chemical precipitation combined with ultrafiltration and inorganic ion exchange. On the basis of lab-scale experiments performed on the same genuine ASWW sample, a comparison has been made between the respective performances of each of these processes in terms of selectivity, decontamination and volume reduction factors. From this assessment, it evolved that solvent extraction and chemical precipitation combined with utrafiltration processes are good competitors for implementing such kind of treatment although for the alpha DF, solvent extraction appears more flexible. To be really attractive, inorganic ion exchange should exhibit better VRF and DF possibly by pretreating the ASWW. 10 refs

  13. Medium modifications of vector mesons

    International Nuclear Information System (INIS)

    Pant, L.M.

    2004-01-01

    The omega photoproduction in nuclear medium with the ELSA facility at Bonn and the present status of the HADES collaboration to investigate the in-medium hadron properties in proton, heavy ions and hadron induced reactions at GSI, Darmstadt are presented. Efforts are under way to utilise the electron beam at Indore for experimental hadron physics in order to step into the intermediate energy nuclear physics regime. The skeletal outline of the high energy electron beam now available at CAT, Indore is discussed

  14. Medium effects in direct reactions

    International Nuclear Information System (INIS)

    Karakoc, M; Bertulani, C

    2013-01-01

    We discuss medium corrections of the nucleon-nucleon (NN) cross sections and their influence on direct reactions at intermediate energies ≳50 MeV/nucleon. The results obtained with free NN cross sections are compared with those obtained with a geometrical treatment of Pauli-blocking and Dirac-Bruecker methods. We show that medium corrections may lead to sizable modifications for collisions at intermediate energies and that they are more pronounced in reactions involving weakly bound nuclei.

  15. Acidity and alkalinity in mine drainage: Theoretical considerations

    Science.gov (United States)

    Kirby, Carl S.; Cravotta,, Charles A.

    2004-01-01

    Acidity, net acidity, and net alkalinity are widely used parameters for the characterization of mine drainage, but these terms are not well defined and are often misunderstood. Incorrect interpretation of acidity, alkalinity, and derivative terms can lead to inadequate treatment design or poor regulatory decisions. We briefly explain derivations of theoretical expressions of three types of alkalinities (caustic, phenolphthalein, and total) and acidities (mineral, CO2, and total). Theoretically defined total alkalinity is closely analogous to measured alkalinity and presents few practical interpretation problems. Theoretically defined “CO2- acidity” is closely related to most standard titration methods used for mine drainage with an endpoint pH of 8.3, but it presents numerous interpretation problems, and it is unfortunately named because CO2 is intentionally driven off during titration of mine-drainage samples. Using the proton condition/massaction approach and employing graphs for visualization, we explore the concept of principal components and how to assign acidity contributions to solution species, including aqueous complexes, commonly found in mine drainage. We define a comprehensive theoretical definition of acidity in mine drainage on the basis of aqueous speciation at the sample pH and the capacity of these species to undergo hydrolysis to pH 8.3. This definition indicates the computed acidity in milligrams per liter (mg L-1 ) as CaCO3 (based on pH and analytical concentrations of dissolved FeIII , FeII , Mn, and Al in mg L-1 ): Aciditycomputed = 50. (10(3-pH) + 3.CFeIII/55.8 + 2.CFeII/55.8 + 2.CMn/54.9 + 3.CAl/27.0) underestimates contributions from HSO4 - and H+ , but overestimates the acidity due to Fe3+. These errors tend to approximately cancel each other. We demonstrate that “net alkalinity” is a valid mathematical construction based on theoretical definitions of alkalinity and acidity. We demonstrate that, for most mine-drainage solutions, a

  16. Effect of alkaline addition on anaerobic sludge digestion with combined pretreatment of alkaline and high pressure homogenization.

    Science.gov (United States)

    Fang, Wei; Zhang, Panyue; Zhang, Guangming; Jin, Shuguang; Li, Dongyi; Zhang, Meixia; Xu, Xiangzhe

    2014-09-01

    To improve anaerobic digestion efficiency, combination pretreatment of alkaline and high pressure homogenization was applied to pretreat sewage sludge. Effect of alkaline dosage on anaerobic sludge digestion was investigated in detail. SCOD of sludge supernatant significantly increased with the alkaline dosage increase after the combined pretreatment because of sludge disintegration. Organics were significantly degraded after the anaerobic digestion, and the maximal SCOD, TCOD and VS removal was 73.5%, 61.3% and 43.5%, respectively. Cumulative biogas production, methane content in biogas and biogas production rate obviously increased with the alkaline dosage increase. Considering both the biogas production and alkaline dosage, the optimal alkaline dosage was selected as 0.04 mol/L. Relationships between biogas production and sludge disintegration showed that the accumulative biogas was mainly enhanced by the sludge disintegration. The methane yield linearly increased with the DDCOD increase as Methane yield (ml/gVS)=4.66 DDCOD-9.69. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Acidic minespoil reclamation with alkaline biosolids

    International Nuclear Information System (INIS)

    Drill, C.; Lindsay, B.J.; Logan, T.L.

    1998-01-01

    The effectiveness of an alkaline stabilized biosolids product, N-Viro Soil (NVS), was studied at a wild animal preserve in Cumberland, OH. The preserve occupies land that was strip mined for high-sulfur coal. While most of the land has been conventionally reclaimed, several highly acidic hot spots remain. Two of these hot spots were studied through concurrent field, greenhouse, and laboratory projects. In April 1995, NVS was applied at rates ranging from 0--960 mt/ha (wet wt.) to plots at the two sites. The plots were seeded using a standard reclamation mix and soil samples were analyzed for chemical characteristics before and after application and also in 1996 and 1997. Soil pH increased from 3.5 to about 11 in the amended plots and soil EC values increased from 21.0 mmho/cm to a maximum of 6.0 mmho/cm in the amended plots immediately after application. Soil Cu and Zn concentrations also increased in the NVS amended plots, but this did not affect plant germination or growth. By the summer of 1996, soil pH values had decreased to 7.3--8.7 and EC values decreased to 0.34--1.36 mmho/cm to the amended plots. Soil samples were collected in September 1995 for physical analyses. N-Viro Soil improved the moisture retention and water conductivity properties of the spoil. The plots were monitored for growth during the summer of 1995 and plant biomass and soil samples were taken in 1996 and 1997 for trace element and nutrient analysis. NVS did not significantly increase trace element concentrations in the biomass. The addition of NVS to acid mine spoil improves the chemical and physical properties of the spoil material thus aiding vegetative establishment and growth. NVS improves the chemical nature of the spoil by increasing pH and providing micro and macronutrients and improves the physical properties of the spoil with the addition of organic matter

  18. Adsorption of anionic surfactants in limestone medium during oil recovery

    Energy Technology Data Exchange (ETDEWEB)

    Canbolat, Serhat; Bagci, Suat [Middle East Technical Univ., Dept. of Petroleum and Natural Gas Engineering, Ankara (Turkey)

    2004-07-15

    Foam-forming surfactant performance was evaluated by several experimental methods (interfacial tension, foam stability, corefloods) using commercial surfactants. There is considerable interest in the use of foam-forming surfactants for mobility control in water flood. To provide effective mobility control, the injected surfactant must propagate from the injection well toward the production well. One of the important parameters affecting propagation of foam-forming surfactant through the reservoir is the retention of surfactant due to its adsorption on reservoir rock. The determination of the adsorption of foam-forming surfactants in limestone reservoirs is important for the residual oil recovery efficiency. Adsorption measurements, recovery efficiencies, and surfactant and alkaline flooding experiments carried out with the representative of the selected surfactants alkaline solutions, linear alkyl benzene sulphonic acid (LABSA), sodium lauryl ether sulfate (SLES), and NaOH in a limestone medium. These surfactants were selected with respect to their foaming ability. Calibration curves formed by pH measurements were used to determine the correct adsorption amount of the used surfactants and recovery efficiency of these surfactants compared with base waterflooding. The results showed that LABSA adsorbed more than SLES in limestone reservoirs. The recovery efficiency of SLES was higher than the recovery efficiency of LABSA, and they decreased the recovery efficiency with respect to only the water injection case. (Author)

  19. Reduction of nitrobenzene with alkaline ascorbic acid: Kinetics and pathways

    International Nuclear Information System (INIS)

    Liang, Chenju; Lin, Ya-Ting; Shiu, Jia-Wei

    2016-01-01

    Highlights: • Alkaline ascorbic acid (a.k.a. vitamin C) is capable of reductively degrading NB. • The pH above the pK_a_2 of ascorbic acid increases reductive electron transfer to NB. • The rate equation for the reactions between NB and AA is determined. • NSB, AZOXY, and AZO are identified as intermediates and aniline as a final product. • Alkaline pH is essential for AA remediation of NB contaminated soils. - Abstract: Alkaline ascorbic acid (AA) exhibits the potential to reductively degrade nitrobenzene (NB), which is the simplest of the nitroaromatic compounds. The nitro group (NO_2"−) of NB has a +III oxidation state of the N atom and tends to gain electrons. The effect of alkaline pH ranging from 9 to 13 was initially assessed and the results demonstrated that the solution pH, when approaching or above the pK_a_2 of AA (11.79), would increase reductive electron transfer to NB. The rate equation for the reactions between NB and AA at pH 12 can be described as r = ((0.89 ± 0.11) × 10"−"4 mM"1"−"("a "+ "b") h"−"1) × [NB]"a "= "1"."3"5 "± "0"."1"0[AA]"b "= "0"."8"9 "± "0"."0"1. The GC/MS analytical method identified nitrosobenzene, azoxybenzene, and azobenzene as NB reduction intermediates, and aniline (AN) as a final product. These experimental results indicate that the alkaline AA reduction of NB to AN mainly proceeds via the direct route, consisting of a series of two-electron or four-electron transfers, and the condensation reaction plays a minor route. Preliminary evaluation of the remediation of spiked NB contaminated soils revealed that maintenance of alkaline pH and a higher water to soil ratio are essential for a successful alkaline AA application.

  20. Serum alkaline phosphatase screening for vitamin D deficiency states

    International Nuclear Information System (INIS)

    Shaheen, S.; Barrakzai, Q.

    2012-01-01

    Objective: To determine whether serum vitamin D levels are correlated with serum levels of alkaline phosphatase or not. Study Design: Cross-sectional, observational study. Place and Duration of Study: Multi-centre study, conducted at Liaquat National Hospital and Medical College, National Medical Centre and Medicare Hospital, Karachi, from January to October 2009. Methodology: Patients attending the Orthopaedic OPDs with complaints of pain in different body regions and serum vitamin D/sub 3/ levels of greater or equal to 30 ng/ml were included in the study. Patients with vitamin D deficiency were further categorized into mild deficiency or insufficiency (vit. D/sub 3/ = 20-29 ng/ml), moderate deficiency (vit. D/sub 3/ = 5 - 19 ng/ml) and severe deficiency forms (vit. D/sub 3/ < 5 ng/ml). Pearson correlation was applied to test the correlation of serum alkaline phosphatase levels with serum vitamin D/sub 3/ levels. P-value < 0.05 was considered to be significant. Results: Out of 110 samples, 26 had mild (23%), 61 had moderate (55%) and 21 had severe (19.1%) vitamin D deficiencies. All of the patients in the three groups had alkaline phosphatase with in normal limits and the total mean value of the enzyme was 135.97 +- 68.14I U/L. The inter group comparison showed highest values of alkaline phosphatase in the moderate vitamin D deficiency group. The correlation coefficient of alkaline phosphatase and serum vitamin D/sub 3/ levels was r =0.05 (p =0.593). Conclusion: Serum vitamin D/sub 3/ levels may not be correlated with increased serum alkaline phosphatase levels. Therefore, alkaline phosphatase may not be used as a screening test to rule out vitamin D deficiency. (author)

  1. Evaluation of some bean lines tolerance to alkaline soil

    Directory of Open Access Journals (Sweden)

    Abeer A. Radi

    2012-01-01

    Full Text Available Introduction: In less arid climates, salts are less concentrated and sodium dominates in carbonate and bicarbonate forms, which enhance the formation of alkaline soils. The development and identification of salt-tolerant crop cultivars or lines would complement salt management programs to improve the productivity and yields of salt stressed plants.Materials and methods: This work was to study the evaluation of alkalinity tolerance of some bean lines grown under different levels of sodium carbonate (Na2CO3 to select the most alkalinity tolerant lines versus the most-sensitive ones out of 6 lines of the test plants.Results: The symptoms induced by alkalinity included reduction in root, shoot growth, and leaf area which were more severe in some bean lines. Potassium leakage was severely affected by alkalinity in some lines at all tested levels, while in some others a moderate damage was manifested only at the higher levels. The increase in Na2CO3 level was associated with a gradual fall in chlorophyll a and b biosynthesis of all the test bean lines. However, alkalinity at low and moderate levels had a favorable effect on the biosynthesis of carotenoids in all the test bean lines. The increase in Na2CO3 supply had a considerable stimulatory effect on sodium accumulation, while potassium accumulation fluctuated in organs of bean lines.Conclusion: Assiut 1104 out of all the different lines investigated was found to display the lowest sensitivity to alkalinity stress, while Assiut 12/104 was the most sensitive one.

  2. Production and Characterization of Alkaline Protease from a High Yielding and Moderately Halophilic Strain of SD11 Marine Bacteria

    Directory of Open Access Journals (Sweden)

    Hongxia Cui

    2015-01-01

    Full Text Available A marine bacterium SD11, which was isolated from sea muds (Geziwo Qinhuangdao Sea area, China, was used to produce thermostable alkaline serine nonmetal protease in the skim milk agar plate medium with 10% NaCl. The optimal temperature about the manufacture of the extracellular protease was ~60°C. The crude enzyme was stable at 20–50°C. The activity was retained to 60% and 45% after heating for 1 h at 60 and 70°C, respectively. The protease was highly active in a wide pH scope (8.0–10.0 and maximum protease activity exhibited at pH 10.0. The activity was restrained by phenylmethylsulfonyl fluoride (PMSF but mildly increased (~107% in the presence of ethylenediaminetetraacetic acid (EDTA, indicating that the production contains serine-protease(s and nonmetal protease(s. Moreover, the crude alkaline protease was active with the 5 mM Ca2+, Mn2+, Zn2+, Cu2+, Na+, and K+ that existed separately. In addition, the protease showed superduper stability when exposed to an anionic surfactant (5 mM SDS, an oxidizing agent (1% H2O2, and several organic solvents (methanol, isopropanol, and acetone. These results suggest that the marine bacterium SD11 is significant in the industry from the prospects of its ability to produce thermally stable alkaline protease.

  3. Application of alkaline solid residue of electric arc furnace dust for neutralization/purification of electroplating wastewaters.

    Science.gov (United States)

    Elez, Loris; Orescanin, Visnja; Sofilic, Tahir; Mikulic, Nenad; Ruk, Damir

    2008-10-01

    The purpose of this work was development of an appropriate procedure for the neutralization/purification of electroplating wastewater (EWW) with alkaline solid residue (ASR) by-product of the alkaline extraction of zinc and lead from electric arc furnace dust (EAFD). Removal efficiency of ASR at optimum purification conditions (pH 8 and mixing time; 20 minutes) for the elements Pb, Cr (VI), Cr (III), Fe, Ni, Cu and Zn were 94.92%, 97.58%, 99.59%, 99.48%, 97.25% and 99.97%, respectively. The concentrations of all elements in the purified wastewater were significantly lower in relation to the upper permissible limit for wastewaters suitable for discharge into the environment. The remaining waste mud was regenerated in the strong alkaline medium and successfully applied once again for the neutralization/purification of EWW. Removal efficiencies of heavy metals accomplished with regenerated waste mud were comparable to these achieved by original ASR. Elemental concentrations in the leachates of the waste mud were in accordance with regulated values.

  4. Impact of 6-month frozen storage of cervical specimens in alkaline buffer conditions on human papillomavirus genotyping.

    Science.gov (United States)

    LaMere, Brandon J; Howell, Renee; Fetterman, Barbara; Shieh, Jen; Castle, Philip E

    2008-08-01

    The impact of 6-month storage of cervical specimens under alkaline conditions that occurs as the result of Hybrid Capture 2 testing on human papillomavirus (HPV) genotyping is not well documented. To examine this issue, 143 frozen hc2-positive specimens in specimen transport medium were selected at random from each of the following groups: specimens stored for 6 months, 4 months, and 2.5 months under alkaline pH (pH 12-13) and specimens stored 1 month at neutral pH (pH 6-7) as controls. Specimens were tested in a masked fashion for 20 HPV genotypes (HPV6, 11, 16, 18, 26, 31, 33, 35, 39, 45, 51, 52, 53, 56, 58, 59, 66, 68, 73, and 82) using a prototype, research-use-only GP5+/6+ L1 consensus PCR method and multiplex hybridization using Luminex xMAP for detection of specific HPV genotypes One control specimen had missing test results. There were no statistical differences in the number of HPV genotypes detected, number of carcinogenic HPV genotypes detected, or in the signal strength among HPV-positive results across groups. Six-month frozen storage of cervical specimens at alkaline pH had little impact on testing for HPV genotypes among hc2-positive women using this HPV genotyping method.

  5. Investigating Mechanisms of Alkalinization for Reducing Primary Breast Tumor Invasion

    Directory of Open Access Journals (Sweden)

    Ian F. Robey

    2013-01-01

    Full Text Available The extracellular pH (pHe of many solid tumors is acidic as a result of glycolytic metabolism and poor perfusion. Acidity promotes invasion and enhances metastatic potential. Tumor acidity can be buffered by systemic administration of an alkaline agent such as sodium bicarbonate. Tumor-bearing mice maintained on sodium bicarbonate drinking water exhibit fewer metastases and survive longer than untreated controls. We predict this effect is due to inhibition of tumor invasion. Reducing tumor invasion should result in fewer circulating tumor cells (CTCs. We report that bicarbonate-treated MDA-MB-231 tumor-bearing mice exhibited significantly lower numbers of CTCs than untreated mice (. Tumor pHe buffering may reduce optimal conditions for enzymes involved in tumor invasion such as cathepsins and matrix metalloproteases (MMPs. To address this, we tested the effect of transient alkalinization on cathepsin and MMP activity using enzyme activatable fluorescence agents in mice bearing MDA-MB-231 mammary xenografts. Transient alkalinization significantly reduced the fluorescent signal of protease-specific activatable agents in vivo (. Alkalinization, however, did not affect expression of carbonic anhydrase IX (CAIX. The findings suggest a possible mechanism in a live model system for breast cancer where systemic alkalinization slows the rate of invasion.

  6. Elevated Serum Level of Human Alkaline Phosphatase in Obesity

    International Nuclear Information System (INIS)

    Khan, A. R.; Awan, F. R.; Najam, S. S.; Islam, M.; Siddique, T.; Zain, M.

    2015-01-01

    Objective: To investigate a correlation between serum alkaline phosphatase level and body mass index in human subjects. Methods: The comparative cross-sectional study was carried out at the National Institute for Biotechnology and Genetic Engineering, Faisalabad, Pakistan, from April 2012 to June 2013. Blood serum alkaline phosphatase levels were estimated and the subjects were divided into three sub-groups on the basis of their body mass index: normal weight (<25kg/m2), overweight (25-27kg/m2) and obese (>27kg/m2) subjects. The serum samples were used for the estimation of clinically important biochemical parameters, using commercial kits on clinical chemistry analyser. Results: Of the 197 subjects, 97(49 percent) were obese and 100(51 percent) were non-obese. The serum alkaline phosphatase level increased in obese (214±6.4 IU/L) compared to the non-obese subjects (184.5±5 IU/L). Furthermore, a significant linear relationship (r=0.3;p-0.0001) was found between serum alkaline phosphatase and body mass index. Other biochemical variables were not correlated to the body mass index. Conclusion: Over activity and higher amounts of alkaline phosphatase were linked to the development of obesity. (author)

  7. Optimization of extracellular thermophilic highly alkaline lipase from thermophilic bacillus sp isolated from hotspring of Arunachal Pradesh, India

    Science.gov (United States)

    Bora, Limpon; Bora, Minakshi

    2012-01-01

    Studies on lipase production were carried out with a bacterial strain (Bacillus sp LBN 2) isolated from soil sample of hotspring of Arunachal Pradesh, India. The cells were cultivated in a mineral medium with maximum production at 1% groundnut oil. The optimum temperature and initial medium pH for lipase production by the organism were 500C and 9.0 respectively. The molecular mass was found to be 33KDa by SDS PAGE. The optimal pH and temperature for activity were 10 and 600C respectively. The enzyme was found to be stable in the pH range of 8–11 with 90% retention of activity at pH 11. The enzyme retained 90% activity at 600C and 70% of activity at 700C for 1h. The lipase was found to be stable in acetone followed by ethanol. The present findings suggested the enzyme to be thermophilic alkaline lipase. PMID:24031801

  8. Increasing Alkalinity Export from Large Russian Arctic Rivers

    Science.gov (United States)

    Drake, T.; Zhulidov, A. V.; Gurtovaya, T. Y.; Spencer, R. G.

    2017-12-01

    Riverine carbonate alkalinity (HCO3- and CO32-) sourced from chemical weathering of minerals on land represents a significant sink for atmospheric CO2 over geologic timescales. The flux of alkalinity from rivers in the Arctic depends on precipitation, permafrost extent and thaw, groundwater flow paths, and surface vegetation, all of which are changing under a warming climate. Here we show that over the past four decades, the export of alkalinity from the Ob' and Yenisei Rivers has more than doubled. The increase is likely due to a combination of increasing precipitation and permafrost thaw in the watersheds, which lengthens hydrologic flow paths and increases residence time in soils. These trends have broad implications for the rate of carbon sequestration on land and the delivery of buffering capacity to the Arctic Ocean.

  9. Decadal Variability of Total Alkalinity in the North Pacific Ocean

    Science.gov (United States)

    Cross, J. N.; Carter, B. R.; Siedlecki, S. A.; Alin, S. R.; Dickson, A. G.; Feely, R. A.; Mathis, J. T.; Wanninkhof, R. H.; Macdonald, A. M.; Mecking, S.; Talley, L. D.

    2016-02-01

    Recent observations of acidification-driven shoaling of the calcium carbonate saturation horizon in the North Pacific have prompted new interest in carbonate cycling in this region, particularly related to impacts on biogenic calcification at the surface layer. Some estimates project that the impacts of OA on alkalinity cycling are beginning to emerge. Here, we present total alkalinity concentrations along a meridional transect of the North Pacific (WOCE, CLIVAR, and US GO-SHIP line P16N; 152 °W) over a period of three decades. The largest source of variability in alkalinity concentrations is related to North Pacific circulation, particularly in the surface mixed layer. Precise normalization of these data reveal some small spatial and temporal variability in the background. We explore these decadal trends in the context of decadal oscillations, ocean biogeochemical cycles, and global change processes such as ocean acidification.

  10. Alkaline Comet Assay for Assessing DNA Damage in Individual Cells.

    Science.gov (United States)

    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. Copyright © 2015 John Wiley & Sons, Inc.

  11. Actinide-Aluminate Speciation in Alkaline Radioactive Waste

    International Nuclear Information System (INIS)

    Clark, David L.; Fedosseev, Alexander M.

    2001-01-01

    Investigation of behavior of actinides in alkaline media containing AL(III) showed that no aluminate complexes of actinides in oxidation states (IIII-VIII) were formed in alkaline solutions. At alkaline precipitation IPH (10-14) of actinides in presence of AL(III) formation of aluminate compounds is not observed. However, in precipitates contained actinides (IIV)<(VI), and to a lesser degree actinides (III), some interference of components takes place that is reflected in change of solid phase properties in comparison with pure components or their mechanical mixture. The interference decreases with rise of precipitation PH and at PH 14 is exhibited very feebly. In the case of NP(VII) the individual compound with AL(III) is obtained, however it is not aluminate of neptunium(VII), but neptunate of aluminium(III) similar to neptunates of other metals obtained earlier

  12. Mineral CO2 sequestration in alkaline solid residues

    International Nuclear Information System (INIS)

    Huijgen, W.J.J.; Comans, R.N.J.; Witkamp, G.J.

    2004-12-01

    Mineral carbonation is a promising sequestration route for the permanent and safe storage of carbon dioxide. In addition to calcium- or magnesium-containing primary minerals, suitable alkaline solid residues can be used as feedstock. The use of alkaline residues has several advantages, such as their availability close to CO2 sources and their higher reactivity for carbonation than primary minerals. In addition, the environmental quality of residues can potentially be improved by carbonation. In this study, key factors of the mineral CO2 sequestration process are identified, their influence on the carbonation process is examined, and environmental properties of the reaction products with regard to their possible beneficial utilization are investigated. The use of alkaline solid residues forms a potentially attractive alternative for the first mineral sequestration plants

  13. Properties of the nuclear medium

    International Nuclear Information System (INIS)

    Baldo, M; Burgio, G F

    2012-01-01

    We review our knowledge on the properties of the nuclear medium that have been studied, over many years, on the basis of many-body theory, laboratory experiments and astrophysical observations. Throughout the presentation particular emphasis is placed on the possible relationship and links between the nuclear medium and the structure of nuclei, including the limitations of such an approach. First we consider the realm of phenomenological laboratory data and astrophysical observations and the hints they can give on the characteristics that the nuclear medium should possess. The analysis is based on phenomenological models, that however have a strong basis on physical intuition and an impressive success. More microscopic models are also considered, and it is shown that they are able to give invaluable information on the nuclear medium, in particular on its equation of state. The interplay between laboratory experiments and astrophysical observations is particularly stressed, and it is shown how their complementarity enormously enriches our insights into the structure of the nuclear medium. We then introduce the nucleon–nucleon interaction and the microscopic many-body theory of nuclear matter, with a critical discussion about the different approaches and their results. The Landau–Fermi liquid theory is introduced and briefly discussed, and it is shown how fruitful it can be in discussing the macroscopic and low-energy properties of the nuclear medium. As an illustrative example, we discuss neutron matter at very low density, and it is shown how it can be treated within the many-body theory. The general bulk properties of the nuclear medium are reviewed to indicate at which stage of our knowledge we stand, taking into account the most recent developments both in theory and experiments. A section is dedicated to the pairing problem. The connection with nuclear structure is then discussed, on the basis of the energy density functional method. The possibility of

  14. Influence of media composition on the production of alkaline α-amylase from Bacillus subtilis CB-18.

    Science.gov (United States)

    Ogbonnaya, Nwokoro; Odiase, Anthonia

    2012-01-01

    Starch, a homopolysaccharide is an important and an abundant food reserve and energy source. Starches are processed to yield different products which find many industrial applications. Alpha-amylases hydrolyze starch by cleaving α-1,4-glucosidic bonds and have been used in food, textile and pharmaceutical industries [Sun et al. 2010]. Enzymatic conversion of starch with amylase presents an economically superior alternative to the conventional method of starch gelatinization. Alkaline α-amylase has an important position in the global enzyme market as a constituent of detergent. In this paper, we screened soil bacteria and an isolate, alkalophilic Bacillus subtilis CB-18 was found to produce an alkaline α-amylase in different media. MATERIAL AND METHODS. Screening of the isolates for amylolytic activity was carried out by growing bacteria isolated from the soil in starch agar plates and subsequently staining the plates with iodine solution to reveal zones of hydrolysis of starch. The selected isolate, Bacillus subtlis CB-18 was grown in different media at alkaline pH to evaluate the influence of media composition on alkaline α-amylase production. Enzyme assay was carried out by growing the culture in a broth medium and obtaining cell - free culture supernatant after centrifugation at 2515 × g for 15 minutes Amylase activity was determined by incubating 0.5 ml of crude enzyme solution in 0.1M Tris/HCl buffer (pH 8.5) with 0.5 ml of 1% soluble starch solution. The reaction was terminated by the addition of DNS reagent and reducing sugar produced from the amylolytic reaction was determined. Bacillus subtilis CB-18 used for this work was selected because it produced 7 mm zone diameter on starch agar plate. This organism was cultured in different alkaline broth media containing 2% soluble starch as inducer carbohydrate for α-amylase production. Among the carbon sources used for enzyme production, sorbitol was the best to stimulate enzyme production with

  15. Geology and petrology of Lages Alkaline District, Santa Catarina State

    International Nuclear Information System (INIS)

    Scheibe, L.F.

    1986-01-01

    A 1:100.000 geological map shows the main outcrops, covering about 50 Km 2 , of the leucocratic alkaline rocks, ultra basic alkaline rocks, carbonatites and volcanic breccias which intruded the Gondwanic sedimentary rocks within a short time interval and characterize the Alkaline District of Lages. Chemical analyses of 33 whole-rock samples confirm the petrographic classification, but the agpaitic indexes, mostly below 1.0, do not reflect the mineralogical variations of the leucocratic alkaline rocks adequately. Partial REE analyses indicate that the light as well as the heavy rare earth contents decrease from the basic to the more evolved rocks, the La/Y ratio remaining approximately constant. Eleven new K/Ar ages from porphyritic nepheline syenites porphyritic phonolites, ultra basic alkaline rocks and pipe-breccias, together with six already available ages, show a major concentration in the range 65 to 75 Ma, with a mode at ca. 70 Ma. But one Rb/Sr whole-rock reference isochron diagram gives an age of 82+-6 Ma for the agpaitic phonolites of the Serra Chapada, which are considered younger than the miaskitic porphyriric nepheline syenites. The 87 Sr/ 86 Sr ratios of 0.705-0.706 are compatible with a sub continental mantelic origin, devoid of crustal contamination. A petrogenetic model based on subtraction diagrams and taking into consideration the geologic, petrographic, mineralogic and petrochemical characteristics of the alkaline rocks of Lages consists of limited partial melting with CO 2 , contribution of the previously metasomatized upper mantle, in a region submitted to decompression. (author)

  16. Alkalinity production in intertidal sands intensified by lugworm bioirrigation.

    Science.gov (United States)

    Rao, Alexandra M F; Malkin, Sairah Y; Montserrat, Francesc; Meysman, Filip J R

    2014-07-05

    Porewater profiles and sediment-water fluxes of oxygen, nutrients, pH, calcium, alkalinity, and sulfide were measured in intertidal sandflat sediments from the Oosterschelde mesotidal lagoon (The Netherlands). The influence of bioturbation and bioirrigation by the deep-burrowing polychaete Arenicola marina on the rates and sources of benthic alkalinity generation was examined by comparing measurements in intact and defaunated sediment cores before and after the addition of A. marina in summer and fall 2011. Higher organic matter remineralization rates, shallower O 2 penetration, and greater sediment-water solute fluxes were observed in summer, consistent with higher sediment community metabolic rates at a higher temperature. Lugworm activity stimulated porewater exchange (5.1 × in summer, 1.9 × in fall), organic matter remineralization (6.2 × in summer, 1.9 × in fall), aerobic respiration (2.4 × in summer, 2.1 × in fall), alkalinity release (4.7 × in summer, 4.0 × in fall), nutrient regeneration, and iron cycling. The effects of lugworm activity on net sediment-water fluxes were similar but more pronounced in summer than in fall. Alkalinity release in fall was entirely driven by metabolic carbonate dissolution, while this process explained between 22 and 69% of total alkalinity production in summer, indicating the importance of other processes in this season. By enhancing organic matter remineralization and the reoxidation of reduced metabolites by the sediment microbial community, lugworm activity stimulated the production of dissolved inorganic carbon and metabolic acidity, which in turn enhanced metabolic CaCO 3 dissolution efficiency. In summer, evidence of microbial long distance electron transport (LDET) was observed in defaunated sediment. Thus, alkalinity production by net carbonate dissolution was likely supplemented by anaerobic respiration and LDET in summer.

  17. Effectiveness of the squeezing out and final squeezing out of petroleum of an increased viscosity by alkaline solutions

    Energy Technology Data Exchange (ETDEWEB)

    Begnazarov, T.

    1979-01-01

    The remaining petroleum in the flooded zone is determined by the ratio of viscosity forces to the forces of the surface tension, which are expressed by the coefficient Ka. With this, for each kind of porous medium, there exists a natural cricial value Ka. For the purpose of studying the effect of the given parameters on the value of the remaining petroleum, experiments were carried out on artificial specimens. In the tests, using petroleum of the Mishkin deposit, the surface tension on the boundary of the petroleum with the distilled water and alkaline solutions were respectively equal to 37.1 and 1.33 dynes per centimeter. The experiments showed, that the squeezing out of the petroleum with water or alkaline solutions leads to similar results. This means, that the composite parameter Ka does not affect the value of the remaining petroleum saturation. The effectiveness of the final squeezing out of the petroleum of increased viscosity was also studied. These experiments were carried out in two variations of the injection of the squeezed out agent: in the first variation, the petroleum was squeezed out with water in the first stage, and in the second stage it was squeezed out by an alkaline solution, and in the subsequent stages, a change in the squeezing out agent took place. By finishing the first stage, the attained values of the coefficients of the squeezing out were practically similar (0.72). In the second stage, the final squeezing out of the petroleum with a solution of alkaline, provided a major effect.

  18. Recovery of manganese oxides from spent alkaline and zinc–carbon batteries. An application as catalysts for VOCs elimination

    Energy Technology Data Exchange (ETDEWEB)

    Gallegos, María V., E-mail: plapimu@yahoo.com.ar [Pla.Pi.Mu-Planta Piloto Multipropósito, (CICPBA-UNLP) Cno. Centenario y 505, M.B. Gonnet, Buenos Aires (Argentina); Falco, Lorena R., E-mail: mlfalco@quimica.unlp.edu.ar [Pla.Pi.Mu-Planta Piloto Multipropósito, (CICPBA-UNLP) Cno. Centenario y 505, M.B. Gonnet, Buenos Aires (Argentina); Peluso, Miguel A., E-mail: apelu@quimica.unlp.edu.ar [Centro de Investigación y Desarrollo en Ciencias Aplicadas, “Dr. J. Ronco” CINDECA (CONICET CCT La Plata), 47 N°257, La Plata, Buenos Aires (Argentina); Sambeth, Jorge E., E-mail: sambeth@quimica.unlp.edu.ar [Centro de Investigación y Desarrollo en Ciencias Aplicadas, “Dr. J. Ronco” CINDECA (CONICET CCT La Plata), 47 N°257, La Plata, Buenos Aires (Argentina); Thomas, Horacio J. [Pla.Pi.Mu-Planta Piloto Multipropósito, (CICPBA-UNLP) Cno. Centenario y 505, M.B. Gonnet, Buenos Aires (Argentina)

    2013-06-15

    Highlights: • Manganese oxides were synthesized using spent batteries as raw materials. • Spent alkaline and zinc–carbon size AA batteries were used. • A biohydrometallurgical process was employed to bio-lixiviate batteries. • Manganese oxides were active in the oxidation of VOCs (ethanol and heptane). - Abstract: Manganese, in the form of oxide, was recovered from spent alkaline and zinc–carbon batteries employing a biohydrometallurgy process, using a pilot plant consisting in: an air-lift bioreactor (containing an acid-reducing medium produced by an Acidithiobacillus thiooxidans bacteria immobilized on elemental sulfur); a leaching reactor (were battery powder is mixed with the acid-reducing medium) and a recovery reactor. Two different manganese oxides were recovered from the leachate liquor: one of them by electrolysis (EMO) and the other by a chemical precipitation with KMnO{sub 4} solution (CMO). The non-leached solid residue was also studied (RMO). The solids were compared with a MnO{sub x} synthesized in our laboratory. The characterization by XRD, FTIR and XPS reveal the presence of Mn{sub 2}O{sub 3} in the EMO and the CMO samples, together with some Mn{sup 4+} cations. In the solid not extracted by acidic leaching (RMO) the main phase detected was Mn{sub 3}O{sub 4}. The catalytic performance of the oxides was studied in the complete oxidation of ethanol and heptane. Complete conversion of ethanol occurs at 200 °C, while heptane requires more than 400 °C. The CMO has the highest oxide selectivity to CO{sub 2}. The results show that manganese oxides obtained using spent alkaline and zinc–carbon batteries as raw materials, have an interesting performance as catalysts for elimination of VOCs.

  19. 1 Medium Regiment, (SAHA), SAA

    African Journals Online (AJOL)

    Scientia Militaria: South African Journal of Military Studies. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 16, No 4 (1986) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. 1 Medium Regiment, (S.A.H.A.), ...

  20. Hadron photoproduction at medium energy

    International Nuclear Information System (INIS)

    Dainton, J.B.

    1985-04-01

    Results from measurements of multibody photoproduction at medium incident photon energy (2.8 to 4.8 GeV) are presented and discussed. Particular emphasis is placed on topics which are not well understood and which therefore motivate experiments with the upgraded electron accelerator and storage ring ELSA at the University of Bonn, FR Germany. (author)

  1. Animal Locomotion in Different Mediums

    Indian Academy of Sciences (India)

    Wetlands are repositories of unique biodiversity. Wetlandorganisms are well adapted to their habitat, lying at theinterface of aquatic and terrestrial environments. In order tounderstand their adaptations in a better way, it is essential tograsp the basic properties of the medium in which variousorganisms live. This is attempted ...

  2. Construction and application of recombinant strain for the production of an alkaline protease from Bacillus licheniformis.

    Science.gov (United States)

    Lin, Songyi; Zhang, Meishuo; Liu, Jingbo; Jones, Gregory S

    2015-03-01

    The alkaline protease gene, Apr, from Bacillus licheniformis 2709 was cloned into an expression vector pET - 28b (+), to yield the recombinant plasmid pET-28b (+) - Apr. The pET-28b (+) - Apr was expressed in a high expression strain E. coli BL21. The amino acid sequence deduced from the DNA sequence analysis revealed a 98% identity to that of Bacillus licheniformis 2709. Sodium salt-Polyacrylamide gel electrophoresis (SDS-PAGE) was used to access the protein expression. SDS-PAGE analysis indicated a protein of Mr of 38.8 kDa. The medium components and condition of incubation were optimized for the growth state of a recombinant strain. The optimal composition of production medium was composed of glucose 8 g/L, peptone 8 g/L and salt solution 10 mL. The samples were incubated on a rotary shaker of 180 r/min at 37°C for 24 h. Copyright © 2014. Published by Elsevier B.V.

  3. Durability of carbon-supported manganese oxide nanoparticles for the oxygen reduction reaction (ORR) in alkaline medium

    Czech Academy of Sciences Publication Activity Database

    Roche, I.; Chainet, E.; Chatenet, M.; Vondrák, Jiří

    2008-01-01

    Roč. 38, č. 9 (2008), s. 1195-1201 ISSN 0021-891X R&D Projects: GA AV ČR KJB4813302; GA ČR GA104/02/0731 Grant - others:CNRS(FR) 18105 Institutional research plan: CEZ:AV0Z40320502 Keywords : oxygen reduction reaction * rotating ring-disc electrode * carbon-supported manganese oxide Subject RIV: CA - Inorganic Chemistry Impact factor: 1.540, year: 2008

  4. Performance of carbon nanofiber supported Pd-Ni catalysts for electro-oxidation of ethanol in alkaline medium

    Science.gov (United States)

    Maiyalagan, T.; Scott, Keith

    Carbon nanofibers (CNF) supported Pd-Ni nanoparticles have been prepared by chemical reduction with NaBH 4 as a reducing agent. The Pd-Ni/CNF catalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electrochemical voltammetry analysis. TEM showed that the Pd-Ni particles were quite uniformly distributed on the surface of the carbon nanofiber with an average particle size of 4.0 nm. The electro-catalytic activity of the Pd-Ni/CNF for oxidation of ethanol was examined by cyclic voltammetry (CV). The onset potential was 200 mV lower and the peak current density four times higher for ethanol oxidation for Pd-Ni/CNF compared to that for Pd/C. The effect of an increase in temperature from 20 to 60 °C had a great effect on increasing the ethanol oxidation activity.

  5. Performance of carbon nanofiber supported Pd-Ni catalysts for electro-oxidation of ethanol in alkaline medium

    Energy Technology Data Exchange (ETDEWEB)

    Maiyalagan, T.; Scott, Keith [School of Chemical Engineering and Advanced Materials, University of Newcastle upon Tyne, Newcastle upon Tyne NE1 7RU (United Kingdom)

    2010-08-15

    Carbon nanofibers (CNF) supported Pd-Ni nanoparticles have been prepared by chemical reduction with NaBH{sub 4} as a reducing agent. The Pd-Ni/CNF catalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electrochemical voltammetry analysis. TEM showed that the Pd-Ni particles were quite uniformly distributed on the surface of the carbon nanofiber with an average particle size of 4.0 nm. The electro-catalytic activity of the Pd-Ni/CNF for oxidation of ethanol was examined by cyclic voltammetry (CV). The onset potential was 200 mV lower and the peak current density four times higher for ethanol oxidation for Pd-Ni/CNF compared to that for Pd/C. The effect of an increase in temperature from 20 to 60 C had a great effect on increasing the ethanol oxidation activity. (author)

  6. Corrosion and inhibition of stainless steel pitting corrosion in alkaline medium and the effect of Cl- and Br- anions

    International Nuclear Information System (INIS)

    Refaey, S.A.M.; Taha, F.; El-Malak, A.M. Abd

    2005-01-01

    The effect of carbonate anion on the pitting corrosion and inhibition behavior of stainless steel samples (304L SS and 316L SS) has been studied using potentiodynamic and scanning electron microscope (SEM) techniques. The effect of concentration of CO 3 2- ions, pH, potential scanning rate and the composition of stainless steel are discussed. Additions of Cl - and Br - ions into the carbonate solution increase the anodic dissolution of stainless steel and decrease its pitting corrosion resistance. The effect of CO 3 2- anion on the inhibition of chloride and bromide pitting corrosion of the two stainless steel types has been studied also. Pitting corrosion decrease with the increasing of sodium carbonate concentration, i.e. increases the resistance of stainless steels towards the chloride and bromide pitting corrosion. This inhibition effect argued to formation of [Fe,Cr]CO 3 film caused by preferential adsorption of the CO 3 2- ion, leading to instantaneous repair of weak sites for pit nucleation

  7. Conditions for the formation of pure birnessite during the oxidation of Mn(II) cations in aqueous alkaline medium

    Energy Technology Data Exchange (ETDEWEB)

    Boumaiza, Hella [Laboratoire de Chimie des Matériaux et Catalyse, Faculté des Sciences de Tunis, Université El Manar (Tunisia); Laboratoire de Chimie Physique et Microbiologie pour l' Environnement (LCPME)-UMR 7564, CNRS-Université de Lorraine, 405, rue de Vandoeuvre, 54600 Villers-lès-Nancy (France); Département de Génie Biologique et Chimique, Institut National des Sciences Appliquées et de Technologies (INSAT), Université de Carthage, Tunis (Tunisia); Coustel, Romain [Laboratoire de Chimie Physique et Microbiologie pour l' Environnement (LCPME)-UMR 7564, CNRS-Université de Lorraine, 405, rue de Vandoeuvre, 54600 Villers-lès-Nancy (France); Medjahdi, Ghouti [Institut Jean Lamour, Centre de Compétences Rayons X et Spectroscopie (X-Gamma), UMR 7198 CNRS-Université de Lorraine (France); Ruby, Christian, E-mail: Christian.ruby@univ-lorraine.fr [Laboratoire de Chimie Physique et Microbiologie pour l' Environnement (LCPME)-UMR 7564, CNRS-Université de Lorraine, 405, rue de Vandoeuvre, 54600 Villers-lès-Nancy (France); and others

    2017-04-15

    Birnessite was synthetized through redox reaction by mixing MnO{sub 4}{sup -}, Mn{sup 2+} and OH{sup -} solutions. The Mn(VII): Mn(II) ratio of 0.33 was chosen and three methods were used consisting in a quick mixing under vigorous stirring of two of the three reagents and then on the dropwise addition of the third one. The obtained solids were characterized by XRD, FTIR and XPS spectroscopies. Their average oxidation states were determined from ICP and CEC measurements while their surface properties were investigated by XPS. This study provides an increased understanding of the importance of dissolved oxygen in the formation of birnessite and hausmannite and shows the ways to obtain pure birnessite. The role of counter-ion ie. Na{sup +} or K{sup +} was also examined. - Graphical abstract: Pathways of birnessite formation. - Highlights: • Pure birnessite is prepared through a redox reaction. • Hausmannite formation is prevented by controlling dissolved O2. • The employed counterion influences the purity of birnessite. • Initial Mn(OH){sub 2} is oxidized by both MnO{sub 4}{sup -} and dissolved O{sub 2}.

  8. Bi-modified Pd/C catalyst via irreversible adsorption and its catalytic activity for ethanol oxidation in alkaline medium

    International Nuclear Information System (INIS)

    Cai, Jindi; Huang, Yiyin; Guo, Yonglang

    2013-01-01

    Highlights: • Pd-Bi/C catalysts were easily prepared by irreversible adsorption of Bi on Pd/C surface. • The adsorption of Bi increases the oxygen-containing species obviously on Pd-Bi/C surface. • Only a little amount of Bi on Pd-Bi/C can play a significant role in ethanol oxidation reaction (EOR). • Current density of EOR on Pd-Bi/C (20:1) is 2.4 times higher than that on Pd/C. • Anti-poisoning ability and durability of Pd-Bi/C (20:1) is greatly enhanced. -- Abstract: A facile approach to promote ethanol electro-oxidation on Pd-based catalysts is presented by the modification of Bi on Pd/C catalyst via irreversible adsorption. X-ray diffraction (XRD), transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS) measurements show that the modification of Bi has no significant effect on the Pd morphology and particle size distribution. Bi(III) and Pd(0) are the dominant forms in Pd-Bi/C catalyst. Electrochemical tests show that the modification of the appropriate amount of Bi on Pd/C catalyst can remarkably enhance activity toward ethanol oxidation reaction (EOR) up to about 2.4 times higher compared to Pd/C catalyst. The Pd-Bi/C (20:1) catalyst exhibits excellent stability and enhances CO tolerance. The enhanced electrochemical performance of Pd-Bi/C catalyst is attributed to the electronic effect and the bifunctional mechanism. The high exchange current density and the low apparent activation energy on Pd-Bi/C (20:1) catalyst reveal its faster kinetics and higher intrinsic activity compared to Pd/C catalyst

  9. Microwave-assisted pechini synthesis of Pd-Ni nanocatalyst for ethanol electro-oxidation in alkaline medium

    CSIR Research Space (South Africa)

    Rohwer, M

    2012-11-01

    Full Text Available Fuel cells provide a means for the direct conversion of fuels to electricity. Direct alcohol fuel cells (DAFCs) are particularly attractive because liquid fuels such as methanol or ethanol have a relatively low cost, a high volumetric energy density...

  10. Behavior of oxygem bubbles during alkaline water electrolysis

    NARCIS (Netherlands)

    Wedershoven, H.M.S.; Jonge, de R.M.; Sillen, C.W.M.P.; Stralen, van S.J.D.

    1982-01-01

    Growth rate, departure radius and population of oxygen bubbles at the transparent anode during alkaline water electrolysis have been investigated experimentally. The supersaturation of dissolved oxygen in the electrolyte adjacent to the anode surface has been derived from bubble growth rates.

  11. Spectroscopic characterization of manganese-doped alkaline earth

    Indian Academy of Sciences (India)

    The intensity and frequency variations for the characteristic phosphate group vibrations have been correlated with the changes of the structural units present in these glasses. Depolymerization of the phosphate chains in all the glasses is observed with replacement of alkaline earth content by spectroscopic studies.

  12. Alkaline protease from senesced leaves of invasive weed Lantana ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-12-17

    Dec 17, 2008 ... amongst the most valuable commercial enzyme. Alkaline proteases hold a great potential for application in the detergent and leather industries (Kumar and Takagi,. 1999; Oberoi et al., 2001) due to the increasing trend to develop environmentally friendly technologies. Plants, animals and microbes are the ...

  13. based anion exchange membrane for alkaline polymer electrolyte

    Indian Academy of Sciences (India)

    Administrator

    Abstract. Hydroxyl ion (OH–) conducting anion exchange membranes based on modified poly (phenylene oxide) are fabricated for their application in alkaline polymer electrolyte fuel cells (APEFCs). In the present study, chloromethylation of poly(phenylene oxide) (PPO) is performed by aryl substitution rather than benzyl.

  14. Mixed alkaline earth effect in sodium aluminosilicate glasses

    DEFF Research Database (Denmark)

    Kjeldsen, Jonas; Smedskjær, Morten Mattrup; Mauro, John C.

    2013-01-01

    While the mixed alkali effect has received significant attention in the glass literature, the mixed alkaline earth effect has not been thoroughly studied. Here, we investigate the latter effect by partial substitution of magnesium for calcium in sodium aluminosilicate glasses. We use Raman and NMR...

  15. Positron collisions with helium and alkaline earth-like atoms

    International Nuclear Information System (INIS)

    Campbell, C.P.

    1998-09-01

    This doctoral thesis is subdivided into: 1. Theory of positron collisions with helium and alkaline earth-like atoms, 2. Positron collisions with helium, magnesium, calcium, zinc, 3. Intercomparison of positron scattering by all those elements. The appendix of this work gives details of the numerical calculations and expands on the wavefunctions used

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

    African Journals Online (AJOL)

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

  17. Isolation of alkaline protease from Bacillus subtilis AKRS3

    African Journals Online (AJOL)

    ashok

    2012-08-28

    Aug 28, 2012 ... production proved high protease production than the other tested ... Crude alkaline protease was most active at 55°C, pH 9 with casein as ... 13416 Afr. J. Biotechnol. ... The Gram-positive, aerobic, rod-shaped endospore-.

  18. Palladium-based nanocatalysts for alcohol electrooxidation in alkaline media

    CSIR Research Space (South Africa)

    Modibedi, RM

    2013-01-01

    Full Text Available in the electrocatalytic oxidation of alcohols in alkaline media compared to platinum catalysts. Recent efforts have focused on the discovery of palladium-based electrocatalysts with little or no platinum for oxygen reduction reaction (ORR). This chapter is an overview...

  19. Potentiodynamic characteristics of cadmium and silver in alkaline solutions

    International Nuclear Information System (INIS)

    Saidman, S.B.; Vilche, J.R.; Arvia, A.J.; Lopes Teijelo, M.

    1984-01-01

    The potentiodynamic and ellipsometric characteristics of cadmium and silver in alkaline solutions are studied. The phenomenology of both electrodes shows some common features which are interpreted in termo of a complex hydrated oxide anodic film structure resulting from simultaneous electrochemical and chemical reactions. The kinetics of film growth fits the predictions of nucleation and growth models. (C.L.B.) [pt

  20. Dephosphorylation of endotoxin by alkaline phosphatase in vivo

    NARCIS (Netherlands)

    Poelstra, Klaas; Bakker, W.W; Klok, P.A; Kamps, J.AAM; Hardonk, M.J; Meijer, D.K F

    1997-01-01

    Natural substrates for alkaline phosphatase (AP) are at present not identified despite extensive investigations. Difficulties in imagining a possible physiological function involve its extremely high pH optimum for the usual exogenous substrates and its localization as an ecto-enzyme. As endotoxin

  1. 21 CFR 864.7660 - Leukocyte alkaline phosphatase test.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Leukocyte alkaline phosphatase test. 864.7660 Section 864.7660 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7660...

  2. Structural variations in layered alkaline earth metal cyclohexyl ...

    Indian Academy of Sciences (India)

    Administrator

    because of the entrance of the guest molecules between the layers, there will be a change in the interlayer distance (Alberti 1978). Although M(IV) organo-phos- phonates are well documented, the chemistry of M(II) organophosphonates especially the alkaline earth metal organophosphonates has been explored marginally ...

  3. Alkalinity production in intertidal sands intensified by lugworm bioirrigation

    NARCIS (Netherlands)

    Rao, A.M.F.; Malkin, S.Y.; Montserrat, F; Meysman, F.J.R.

    2014-01-01

    Porewater profiles and sediment-water fluxes of oxygen, nutrients, pH, calcium, alkalinity, and sulfide were measured in intertidal sandflat sediments from the Oosterschelde mesotidal lagoon (The Netherlands). The influence of bioturbation and bioirrigation by the deep-burrowing polychaete

  4. Alkalinity Analysis. Training Module 5.220.2.77.

    Science.gov (United States)

    Bonte, John L.; Davidson, Arnold C.

    This document is an instructional module package prepared in objective form for use by an instructor familiar with the acid-base titrimetric procedure for determining the hydroxide, carbonate and bicarbonate alkalinity of a water sample. Included are objectives, an instructor guide, student handouts and transparency masters. A video tape is also…

  5. A green method of graphene preparation in an alkaline environment

    Czech Academy of Sciences Publication Activity Database

    Štengl, Václav; Henych, Jiří; Bludská, Jana; Ecorchard, Petra; Kormunda, M.

    2015-01-01

    Roč. 24, MAY (2015), s. 65-71 ISSN 1350-4177 R&D Projects: GA ČR(CZ) GA14-05146S Institutional support: RVO:61388980 Keywords : Alkaline environment * Exfoliation * Graphene * Ultrasound Subject RIV: CA - Inorganic Chemistry Impact factor: 4.556, year: 2015

  6. Extracellular Alkalinization as a Defense Response in Potato Cells.

    Science.gov (United States)

    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.

  7. Modelling the crystallisation of alkaline earth boroaluminosilicate glass ceramics

    DEFF Research Database (Denmark)

    Svenson, Mouritz Nolsøe; Agersted, Karsten; Holm, Paul Martin

    2014-01-01

    To investigate the potential use of a thermochemical software package (FactSage 6.2), in the design of alkaline earth boroaluminosilicate glass ceramics, experimental and modelled results on four glass ceramics were compared. Initially large discrepancies were found. These are described and related...

  8. Kinetic characteristics of acidic and alkaline ceramidase in human epidermis

    NARCIS (Netherlands)

    Houben, E.; Uchida, Y.; Nieuwenhuizen, W.F.; Paepe, K. de; Vanhaecke, T.; Holleran, W.M.; Rogiers, V.

    2007-01-01

    It has recently become evident that at least five ceramidase (CDase) isoforms are present in human epidermis, and that specifically acidic CDase (aCDase) and alkaline CDase (alkCDase) activities increase during keratinocyte differentiation, and thus might play a pivotal role(s) in permeability

  9. Soil salinity and alkalinity in the Great Konya Basin, Turkey

    NARCIS (Netherlands)

    Driessen, P.M.

    1970-01-01

    In the summers of 1964 to 1968 a study was made of soil salinity and alkalinity in the Great Konya Basin, under the auspices of the Konya Project, a research and training programme of the Department of Tropical Soil Science of the Agricultural University, Wageningen.

    The Great

  10. Alkaline phosphatase activity in gingival crevicular fluid during canine retraction.

    Science.gov (United States)

    Batra, P; Kharbanda, Op; Duggal, R; Singh, N; Parkash, H

    2006-02-01

    The aim of the study was to investigate alkaline phosphatase activity in the gingival crevicular fluid (GCF) during orthodontic tooth movement in humans. Postgraduate orthodontic clinic. Ten female patients requiring all first premolar extractions were selected and treated with standard edgewise mechanotherapy. Canine retraction was done using 100 g sentalloy springs. Maxillary canine on one side acted as experimental site while the contralateral canine acted as control. Gingival crevicular fluid was collected from mesial and distal of canines before initiation of canine retraction (baseline), immediately after initiation of retraction, and on 1st, 7th, 14th and 21st day and the alkaline phosphatase activity was estimated. The results show significant (p < 0.05) changes in alkaline phosphatase activity on the 7th, 14th and 21st day on both mesial and distal aspects of the compared experimental and control sides. The peak in enzyme activity occurred on the 14th day of initiation of retraction followed by a significant fall in activity especially on the mesial aspect. The study showed that alkaline phosphatase activity could be successfully estimated in the GCF using calorimetric estimation assay kits. The enzyme activity showed variation according to the amount of tooth movement.

  11. High-level expression of alkaline protease using recombinant ...

    African Journals Online (AJOL)

    AJL

    2012-02-16

    Feb 16, 2012 ... compared with that of wild-type B. licheniformis CICIM B5102. Key word: Alkaline protease, Bacillus amyloliquefaciens, Bacillus licheniformis. INTRODUCTION. Proteases are one of the most important industrial enzyme groups, accounting for approximately 60% of the total enzyme sales (Beg et al., 2003).

  12. Effects of Mixed Alkaline Earth Oxides in Potash Silicate Glass ...

    African Journals Online (AJOL)

    The aim of this work is to investigate the effects of mixed alkaline earth oxide in potash silicate glasses with regards to their physical properties. More recently; there has been an increase in the demand for light weight glasses which retains their physical and chemical properties for both domestic and industrial applications.

  13. Alkaline-earth metal phenylphosphonates and their intercalation chemistry

    Czech Academy of Sciences Publication Activity Database

    Melánová, Klára; Beneš, L.; Svoboda, J.; Zima, Vítězslav; Pospíšil, M.; Kovář, P.

    2018-01-01

    Roč. 47, č. 9 (2018), s. 2867-2880 ISSN 1477-9226 R&D Projects: GA ČR(CZ) GA17-10639S Institutional support: RVO:61389013 Keywords : intercalation * layered compounds * alkaline-earth metal phenylphosphonates Subject RIV: CA - Inorganic Chemistry OBOR OECD: Inorganic and nuclear chemistry Impact factor: 4.029, year: 2016

  14. Reduction of nitrobenzene with alkaline ascorbic acid: Kinetics and pathways

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Chenju, E-mail: cliang@nchu.edu.tw [Department of Environmental Engineering, National Chung Hsing University 250, Kuo-kuang Road, Taichung 402, Taiwan (China); Lin, Ya-Ting [Department of Environmental Engineering, Chung Yuan Christian University, 200 Chung Pei Road, Chung Li District, Taoyuan City 320, Taiwan (China); Shiu, Jia-Wei [Department of Environmental Engineering, National Chung Hsing University 250, Kuo-kuang Road, Taichung 402, Taiwan (China)

    2016-01-25

    Highlights: • Alkaline ascorbic acid (a.k.a. vitamin C) is capable of reductively degrading NB. • The pH above the pK{sub a2} of ascorbic acid increases reductive electron transfer to NB. • The rate equation for the reactions between NB and AA is determined. • NSB, AZOXY, and AZO are identified as intermediates and aniline as a final product. • Alkaline pH is essential for AA remediation of NB contaminated soils. - Abstract: Alkaline ascorbic acid (AA) exhibits the potential to reductively degrade nitrobenzene (NB), which is the simplest of the nitroaromatic compounds. The nitro group (NO{sub 2}{sup −}) of NB has a +III oxidation state of the N atom and tends to gain electrons. The effect of alkaline pH ranging from 9 to 13 was initially assessed and the results demonstrated that the solution pH, when approaching or above the pK{sub a2} of AA (11.79), would increase reductive electron transfer to NB. The rate equation for the reactions between NB and AA at pH 12 can be described as r = ((0.89 ± 0.11) × 10{sup −4} mM{sup 1−(a} {sup +} {sup b)} h{sup −1}) × [NB]{sup a} {sup =} {sup 1.35} {sup ±} {sup 0.10}[AA]{sup b} {sup =} {sup 0.89} {sup ±} {sup 0.01}. The GC/MS analytical method identified nitrosobenzene, azoxybenzene, and azobenzene as NB reduction intermediates, and aniline (AN) as a final product. These experimental results indicate that the alkaline AA reduction of NB to AN mainly proceeds via the direct route, consisting of a series of two-electron or four-electron transfers, and the condensation reaction plays a minor route. Preliminary evaluation of the remediation of spiked NB contaminated soils revealed that maintenance of alkaline pH and a higher water to soil ratio are essential for a successful alkaline AA application.

  15. Holographic Renormalization in Dense Medium

    International Nuclear Information System (INIS)

    Park, Chanyong

    2014-01-01

    The holographic renormalization of a charged black brane with or without a dilaton field, whose dual field theory describes a dense medium at finite temperature, is investigated in this paper. In a dense medium, two different thermodynamic descriptions are possible due to an additional conserved charge. These two different thermodynamic ensembles are classified by the asymptotic boundary condition of the bulk gauge field. It is also shown that in the holographic renormalization regularity of all bulk fields can reproduce consistent thermodynamic quantities and that the Bekenstein-Hawking entropy is nothing but the renormalized thermal entropy of the dual field theory. Furthermore, we find that the Reissner-Nordström AdS black brane is dual to a theory with conformal matter as expected, whereas a charged black brane with a nontrivial dilaton profile is mapped to a theory with nonconformal matter although its leading asymptotic geometry still remains as AdS space

  16. Medium modifications with recoil polarization

    Energy Technology Data Exchange (ETDEWEB)

    Brand, J.F.J. van den [Nationaal Instituut voor Kernfysica en Hoge Energiefysica, Amsterdam (Netherlands); Ent, R. [CEBAF, Newport News, VA (United States)

    1994-04-01

    The authors show that the virtual Compton scattering process allows for a precise study of the off-shell electron-nucleon vertex. In a separable model, they show the sensitivity to new unconstrained structure functions of the nucleon, beyond the usual Dirac and Pauli form factors. In addition, they show the sensitivity to bound nucleon form factors using the reaction 4He({rvec e},e{prime},{rvec p}){sup 3}H. A nucleon embedded in a nucleus represents a complex system. Firstly, the bound nucleon is necessarily off-shell and in principle a complete understanding of the dynamical structure of the nucleon is required in order to calculate its off-shell electromagnetic interaction. Secondly, one faces the possibility of genuine medium effects, such as for example quark-exchange contributions. Furthermore, the electromagnetic coupling to the bound nucleon is dependent on the nuclear dynamics through the self-energy of the nucleon in the nuclear medium.

  17. Medium modifications with recoil polarization

    International Nuclear Information System (INIS)

    Brand, J.F.J. van den; Ent, R.

    1994-01-01

    The authors show that the virtual Compton scattering process allows for a precise study of the off-shell electron-nucleon vertex. In a separable model, they show the sensitivity to new unconstrained structure functions of the nucleon, beyond the usual Dirac and Pauli form factors. In addition, they show the sensitivity to bound nucleon form factors using the reaction 4He(rvec e,e',rvec p) 3 H. A nucleon embedded in a nucleus represents a complex system. Firstly, the bound nucleon is necessarily off-shell and in principle a complete understanding of the dynamical structure of the nucleon is required in order to calculate its off-shell electromagnetic interaction. Secondly, one faces the possibility of genuine medium effects, such as for example quark-exchange contributions. Furthermore, the electromagnetic coupling to the bound nucleon is dependent on the nuclear dynamics through the self-energy of the nucleon in the nuclear medium

  18. Electromigration in molten salts and application to isotopic separation of alkaline and alkaline-earth elements

    International Nuclear Information System (INIS)

    Menes, F.

    1969-01-01

    The separation of the isotopes of the alkaline-earth elements has been studied using counter-current electromigration in molten bromides. The conditions under which the cathode operates as a bromine electrode for the highest possible currents have been examined. For the separation of calcium, it has been necessary to use a stable CaBr 2 - (CaBr 2 + KBr) 'chain'. In the case of barium and strontium, it was possible to employ the pure bromides. Enrichment factors of the order of 10 for 48 Ca and of the order of 1.5 for the rare isotopes of barium and strontium have been obtained. In the case of magnesium the method is slightly more difficult to apply because of material loss due to the relatively high vapour pressure of the salt requiring the use of electrolyte chains, MgBr 2 - CeBr 3 . A study has been made that has led to a larger-scale application of the method. These are essentially the inhibition of reversible operation of the cathode by traces of water, limiting the intensity which can be tolerated; evacuation of the heat produced by the Joule effect, in the absence of which the separation efficiency is reduced by thermal gradients; corrosion of the materials by molten salts at high temperature. Several cells capable of treating a few kilograms of substance have been put into operation; none of these has lasted long enough to produce a satisfactory enrichment. The method is thus limited actually to yields of the order of a few grams. (author) [fr

  19. Medium Theory and Social Systems

    DEFF Research Database (Denmark)

    Tække, Jesper

      the  possibility  for  observation both of a social micro and a social macro level from a medium perspective. In the next  section  the paper  frames  the macro  level by  a  tentative  synthesis of  the medium  theory  and  the  sociological systems theory briefly describing a socio......-evolutionary process where new media alter  the societal capacity to handle complexity  in  time and space.  In  this section it becomes probable  that  by  means  of  different  media,  social  systems  give  different  possibilities  for  actual  social  performance.  In a way,  social  systems  themselves can be......  seen as medium  for  formation. Finally  the  paper  takes  the micro  level  perspective  by  applying  the  theory  to  newsgroups,  interpreting  them as self-organizing interactive systems giving a differentiated and diversified scope for social  inclusion.  ...

  20. Nixtamalized flour from quality protein maize (Zea mays L). optimization of alkaline processing.

    Science.gov (United States)

    Milán-Carrillo, J; Gutiérrez-Dorado, R; Cuevas-Rodríguez, E O; Garzón-Tiznado, J A; Reyes-Moreno, C

    2004-01-01

    Quality of maize proteins is poor, they are deficient in the essential amino acids lysine and tryptophan. Recently, in Mexico were successfully developed nutritionally improved 26 new hybrids and cultivars called quality protein maize (QPM) which contain greater amounts of lysine and tryptophan. Alkaline cooking of maize with lime (nixtamalization) is the first step for producing several maize products (masa, tortillas, flours, snacks). Processors adjust nixtamalization variables based on experience. The objective of this work was to determine the best combination of nixtamalization process variables for producing nixtamalized maize flour (NMF) from QPM V-537 variety. Nixtamalization conditions were selected from factorial combinations of process variables: nixtamalization time (NT, 20-85 min), lime concentration (LC, 3.3-6.7 g Ca(OH)2/l, in distilled water), and steep time (ST, 8-16 hours). Nixtamalization temperature and ratio of grain to cooking medium were 85 degrees C and 1:3 (w/v), respectively. At the end of each cooking treatment the steeping started for the required time. Steeping was finished by draining the cooking liquor (nejayote). Nixtamal (alkaline-cooked maize kernels) was washed with running tap water. Wet nixtamal was dried (24 hours, 55 degrees C) and milled to pass through 80-US mesh screen to obtain NMF. Response surface methodology (RSM) was applied as optimization technique, over four response variables: In vitro protein digestibility (PD), total color difference (deltaE), water absorption index (WAI), and pH. Predictive models for response variables were developed as a function of process variables. Conventional graphical method was applied to obtain maximum PD, WAI and minimum deltaE, pH. Contour plots of each of the response variables were utilized applying superposition surface methodology, to obtain three contour plots for observation and selection of best combination of NT (31 min), LC (5.4 g Ca(OH)2/l), and ST (8.1 hours) for producing

  1. Fabrication of hydrogels with elasticity changed by alkaline phosphatase for stem cell culture.

    Science.gov (United States)

    Toda, Hiroyuki; Yamamoto, Masaya; Uyama, Hiroshi; Tabata, Yasuhiko

    2016-01-01

    The objective of this study is to design hydrogels whose elasticity can be changed by alkaline phosphatase (ALP) in cell culture and evaluate the effect of hydrogel elasticity on an osteogenic gene expression of cells. Hydrogels were prepared by the radical polymerization of acrylamide (AAm), N,N'-methylenebisacrylamide (BIS), and Phosmer™M containing phosphate groups (PE-PAAm hydrogels). The storage modulus of PE-PAAm hydrogels prepared was changed by the preparation conditions. When human mesenchymal stem cells (hMSC) were cultured on the ALP-responsive PE-PAAm hydrogels in the presence or absence of ALP, the morphology of hMSC was observed and one of the osteogenic differentiation markers, Runx2, was evaluated. By ALP addition into the culture medium, the morphology of hMSC was changed into an elongated shape without cell damage. ALP addition modified the level of Runx2 gene expression, which was influenced by the modulus of PE-PAAm hydrogels. It is concluded that the elasticity change of hydrogel substrates in cell culture had an influence on the Runx2 gene expression of hMSC. Stem cells sense the surface elasticity of culture substrates, and their differentiation fate is biologically modified by substrate properties. Most of experiments have been performed in static conditions during cell culture, while the in vivo microenvironment is dynamically changed. In this study, we established to design an enzyme-responsive hydrogel whose elasticity can be changed by alkaline phosphatase (ALP) in cell culture to mimic in vivo conditions. As a result, the cells were deformed and the gene expression level of an osteogenic maker, Runx2, was modified by ALP treatment. This is the novel report describing to demonstrate that the dynamic alteration of hydrogel substrate elasticity could modulate the osteoblastic gene expression of human MSC in vitro. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  2. Medium energy ion scattering (MEIS)

    International Nuclear Information System (INIS)

    Dittmann, K.; Markwitz, A.

    2009-01-01

    This report gives an overview about the technique and experimental study of medium energy ion scattering (MEIS) as a quantitative technique to determine and analyse the composition and geometrical structure of crystalline surfaces and near surface-layers by measuring the energy and yield of the backscattered ions. The use of a lower energy range of 50 to 500 keV accelerated ions impinging onto the target surface and the application of a high-resolution electrostatic energy analyser (ESA) makes medium energy ion scattering spectroscopy into a high depth resolution and surface-sensitive version of RBS with less resulting damage effects. This report details the first steps of research in that field of measurement technology using medium energetic backscattered ions detected by means of a semiconductor radiation detector instead of an ESA. The study of medium energy ion scattering (MEIS) has been performed using the 40 keV industrial ion implanter established at GNS Sciences remodelled with supplementary high voltage insulation for the ion source in order to apply voltages up to 45 kV, extra apertures installed in the beamline and sample chamber in order to set the beam diameter accurately, and a semiconductor radiation detector. For measurement purposes a beam of positive charged helium ions accelerated to an energy of about 80 keV has been used impinging onto target surfaces of lead implanted into silicon (PbSi), scandium implanted into aluminium (ScAl), aluminium foil (Al) and glassy carbon (C). First results show that it is possible to use the upgraded industrial implanter for medium energy ion scattering. The beam of 4 He 2+ with an energy up to 88 keV has been focussed to 1 mm in diameter. The 5 nA ion beam hit the samples under 2 x 10 -8 mbar. The results using the surface barrier detector show scattering events from the samples. Cooling of the detector to liquid nitrogen temperatures reduced the electronic noise in the backscattering spectrum close to zero. A

  3. High-Efficiency Artificial Photosynthesis Using a Novel Alkaline Membrane Cell

    Science.gov (United States)

    Narayan, Sri; Haines, Brennan; Blosiu, Julian; Marzwell, Neville

    2009-01-01

    A new cell designed to mimic the photosynthetic processes of plants to convert carbon dioxide into carbonaceous products and oxygen at high efficiency, has an improved configuration using a polymer membrane electrolyte and an alkaline medium. This increases efficiency of the artificial photosynthetic process, achieves high conversion rates, permits the use of inexpensive catalysts, and widens the range of products generated by this type of process. The alkaline membrane electrolyte allows for the continuous generation of sodium formate without the need for any additional separation system. The electrolyte type, pH, electrocatalyst type, and cell voltage were found to have a strong effect on the efficiency of conversion of carbon dioxide to formate. Indium electrodes were found to have higher conversion efficiency compared to lead. Bicarbonate electrolyte offers higher conversion efficiency and higher rates than water solutions saturated with carbon dioxide. pH values between 8 and 9 lead to the maximum values of efficiency. The operating cell voltage of 2.5 V, or higher, ensures conversion of the carbon dioxide to formate, although the hydrogen evolution reaction begins to compete strongly with the formate production reaction at higher cell voltages. Formate is produced at indium and lead electrodes at a conversion efficiency of 48 mg of CO2/kilojoule of energy input. This efficiency is about eight times that of natural photosynthesis in green plants. The electrochemical method of artificial photosynthesis is a promising approach for the conversion, separation and sequestration of carbon dioxide for confined environments as in space habitats, and also for carbon dioxide management in the terrestrial context. The heart of the reactor is a membrane cell fabricated from an alkaline polymer electrolyte membrane and catalyst- coated electrodes. This cell is assembled and held in compression in gold-plated hardware. The cathode side of the cell is supplied with carbon

  4. Environmental variables evaluation on concrete structures corrosion for medium level activities repositories

    International Nuclear Information System (INIS)

    Requena, Carlos; Alvarez, Marta G.; Duffo, Gustavo S.

    2000-01-01

    The main purpose of this work was to evaluate the long term durability of reinforced concrete structures as medium-level waste container material. Electrochemical techniques have been used to evaluate the corrosion behaviour of steel rebars in several solutions simulating the liquid present in the pores of both alkaline and carbonated concrete in the presence of sulphate ions. Results shown that a decrease in p H has an adverse effect on the critical sulphate concentration. The inhibition effect of high carbonate/bicarbonate concentration is also shown. (author)

  5. Accretion from an inhomogeneous medium

    International Nuclear Information System (INIS)

    Livio, M.; Soker, N.; Koo, M. de; Savonije, G.J.

    1986-01-01

    The problem of accretion by a compact object from an inhomogeneous medium is studied in the general γnot=1 case. The mass accretion rate is found to decrease with increasing γ. The rate of accretion of angular momentum is found to be significantly lower than the rate at which angular momentum is deposited into the Bondi-Hoyle, symmetrical, accretion cylinder. The consequences of the results are studied for the cases of neutron stars accreting from the winds of early-type companions and white dwarfs and main-sequence stars accreting from winds of cool giants. (author)

  6. A Heterogeneous Medium Analytical Benchmark

    International Nuclear Information System (INIS)

    Ganapol, B.D.

    1999-01-01

    A benchmark, called benchmark BLUE, has been developed for one-group neutral particle (neutron or photon) transport in a one-dimensional sub-critical heterogeneous plane parallel medium with surface illumination. General anisotropic scattering is accommodated through the Green's Function Method (GFM). Numerical Fourier transform inversion is used to generate the required Green's functions which are kernels to coupled integral equations that give the exiting angular fluxes. The interior scalar flux is then obtained through quadrature. A compound iterative procedure for quadrature order and slab surface source convergence provides highly accurate benchmark qualities (4- to 5- places of accuracy) results

  7. Charmed hadrons in nuclear medium

    International Nuclear Information System (INIS)

    Tolos, L.; Gamermann, D.; Molina, R.; Nieves, J.; Oset, E.; Garcia-Recio, C.; Ramos, A.

    2010-01-01

    We study the properties of charmed hadrons in dense matter within a coupled-channel approach which accounts for Pauli blocking effects and meson self-energies in a self-consistent manner. We analyze the behaviour in this dense environment of dynamically-generated baryonic resonances as well as the open-charm meson spectral functions. We discuss the implications of the in-medium properties of open-charm mesons on the D s0 (2317) and the predicted X(3700) scalar resonances. (authors)

  8. Development of brachytherapy medium doserate

    International Nuclear Information System (INIS)

    Atang Susila; Ari Satmoko; Ahmad Rifai; Kristiyanti

    2010-01-01

    Brachytherapy has proven to be an effective treatment for different types of cancers and it become a common treatment modality in most radiotherapy clinics. PRPN has had experience in development of Low Dose Rate Brachytherapy for cervix cancer treatment. However the treatment process using LDR device needs 5 hours in time that the patient feel uncomfort. Therefore PRPN develops Medium Dose Rate Brachytherapy with radiation activity not more than 5 Currie. The project is divided into two stages. Purchasing of TPS software and TDS design are held in 2010, and the construction will be in 2011. (author)

  9. Alkylation of imidazole under ultrasound irradiation over alkaline carbons

    International Nuclear Information System (INIS)

    Costarrosa, L.; Calvino-Casilda, V.; Ferrera-Escudero, S.; Duran-Valle, C.J.; Martin-Aranda, R.M.

    2006-01-01

    N-Alkyl-imidazole has been synthesized by sonochemical irradiation of imidazole and 1-bromobutane using alkaline-promoted carbons (exchanged with the binary combinations of Na, K and Cs). The catalysts were characterized by X-ray photoelectron spectroscopy, thermal analysis and N 2 adsorption isotherms. Under the experimental conditions, N-alkyl-imidazoles can be prepared with a high activity and selectivity. It is observed that imidazole conversion increases in parallel with increasing the basicity of the catalyst. The influence of the alkaline promoter, the reaction temperature, and the amount of catalyst on the catalytic activity has been studied. For comparison, the alkylation of imidazole has also been performed in a batch reactor system under thermal activation

  10. Thermochemical and thermophysical properties of alkaline-earth perovskites

    International Nuclear Information System (INIS)

    Yamanaka, Shinsuke; Kurosaki, Ken; Maekawa, Takuji; Matsuda, Tetsushi; Kobayashi, Shin-ichi; Uno, Masayoshi

    2005-01-01

    In order to contribute to safety evaluation of high burnup oxide fuels, we studied the thermochemical and thermophysical properties of alkaline-earth perovskites known as oxide inclusions. Polycrystalline samples of alkaline-earth perovskites, BaUO 3 , BaZrO 3 , BaCeO 3 , BaMoO 3 , SrTiO 3 , SrZrO 3 , SrCeO 3 , SrMoO 3 , SrHfO 3 and SrRuO 3 , were prepared and the thermal expansion coefficient, melting temperature, elastic moduli, Debye temperature, microhardness, heat capacity, and thermal conductivity were measured. The relationship between some physical properties was studied

  11. Investigating mechanisms of alkalinization for reducing primary breast tumor invasion.

    Science.gov (United States)

    Robey, Ian F; Nesbit, Lance A

    2013-01-01

    The extracellular pH (pHe) of many solid tumors is acidic as a result of glycolytic metabolism and poor perfusion. Acidity promotes invasion and enhances metastatic potential. Tumor acidity can be buffered by systemic administration of an alkaline agent such as sodium bicarbonate. Tumor-bearing mice maintained on sodium bicarbonate drinking water exhibit fewer metastases and survive longer than untreated controls. We predict this effect is due to inhibition of tumor invasion. Reducing tumor invasion should result in fewer circulating tumor cells (CTCs). We report that bicarbonate-treated MDA-MB-231 tumor-bearing mice exhibited significantly lower numbers of CTCs than untreated mice (P cancer where systemic alkalinization slows the rate of invasion.

  12. Radiolysis of actinides and technetium in alkaline media

    Energy Technology Data Exchange (ETDEWEB)

    Delegard, C.H., Westinghouse Hanford

    1996-07-10

    The {gamma}-radiolysis of aerated alkaline aqueous solutions of Np(V), Np(VI), Pu(VI), Tc(IV), Tc(V), and TC(VII) was studied in the absence of additives and in the presence of CO{sub 3}{sup 2-}, NO{sub 3}{sup -}, NO{sub 2}{sup -}, EDTA, formate, and other organic compounds. The radiolytic reduction of Np(V), Np(VI), Pu(VI), and TC(VII) under different experimental conditions was examined in detail. The addition of EDTA, formate, and alcohols was found to considerably increase the radiation-chemical reduction yields. The formation of the Np(V) peroxo complex was observed in the {gamma}-radiolysis of alkaline aqueous solutions of Np (VI) in the presence of nitrate.

  13. Lithuanian Quarry Aggregates Concrete Effects of Alkaline Corrosion Tests

    Directory of Open Access Journals (Sweden)

    Aurimas Rutkauskas

    2016-02-01

    Full Text Available Aggregate alkaline corrosion of cement in concrete is going to respond in sodium and potassium hydroxide (lye with active SiO2 found in some aggregates. During this reaction, the concrete has resulted in significant internal stresses which cause deformation of the concrete, cracking and disintegration. The reaction is slow and concrete signs of decomposition appear only after a few months or years. The study used two different aggregates quarries. Studies show that Lithuania gravel contaminated with reactive particles having amorphous silicon dioxide reacting with cement in sodium and potassium hydroxide and the resulting alkaline concrete corrosion. It was found that, according to AAR 2 large aggregates include Group II – potentially reactive because of their expansion after 14 days, higher than 0.1%.

  14. Oxidative degradation of Boltysh shale by alkaline potassium permanganate

    Energy Technology Data Exchange (ETDEWEB)

    Pobul, I Ya; Fomina, A S

    1974-01-01

    This reaction proceeded in stages at 47 to 48/sup 0/C with a 3 percent solution of potassium permanganate in a 1 percent alkaline solution. The products were separated into groups and identified by gas-liquid chromatography. Small amounts of monocarboxylic acids were identified, with normal and branched chains, from acetic to lauric acid. Dicarboxylic acids were mainly of normal structure, or methyl substituted, from succinic to hexadecanedicarboxylic acid. No tricarboxylic acids were detected. For products of primary oxidation insoluble in acid media, a high content of C/sub 10/-C/sub 16/ acids was characteristic, and for the final degree of oxidation C/sub 11/-C/sub 18/ acids. The organic portion of shale consists of structural units, differing in mass and in stability to alkaline permanganate.

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

    Energy Technology Data Exchange (ETDEWEB)

    Choe, Yoong-Kee [National Institute of Advanced Industrial Science and Technology, Umezono 1-1-1, Tsukuba (Japan); Henson, Neil J.; Kim, Yu Seung [Los Alamos National Laboratory, Los Alamos, NM (United States)

    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.

  16. Comparison of oxidants in alkaline leaching of uranium ore

    International Nuclear Information System (INIS)

    Sreenivas, T.; Rajan, K.C.; Srinivas, K.; Anand Rao, K.; Manmadha Rao, M.; Venkatakrishnan, R.R.; Padmanabhan, N.P.H.

    2007-01-01

    The uranium minerals occurring in various ore deposits consists of predominantly uranous ion (U +4 ), necessitating use of an oxidant and other lixiviants for efficient dissolution during leaching. Unlike acid leaching route, where uranium minerals dissolution could be achieved efficiently with cheaper lixiviants, processing of ores by alkaline leaching route involve expensive lixiviants and drastic leaching conditions. Alkaline leaching of uranium ores becomes economical only upon using cheaper and efficient oxidants and conservation of other reagents by their recycle. The present paper gives efficacy of various oxidants - KMnO 4 , NaOCl, Cu - NH 3 , air and oxygen, in the leaching of uranium from a low-grade dolostone hosted uranium ore of India. A comparison based on technical merits and cost of the oxidant chemicals is discussed. (author)

  17. Radium, uranium and metals in acidic or alkaline uranium mill

    International Nuclear Information System (INIS)

    Somot, St.

    1997-01-01

    Uranium mill study sites have been chosen in function of their different characteristics: deposits age, treatment nature (alkaline or acid), mill origin. The realization of specific drilling allowed the simultaneous study of the interstitial water and the solid fraction of samples, cut at determined deep. A radiation imbalance between 230 Th and 226 Ra is observed in the acid treatment residues. The trace elements concentration spectrum is directly bound to the nature of the ore. Diamagnetic evolutions are observed in residues. The uranium concentrations are higher in carbonated waters than in calcic sulfated waters. The selective sequential lixiviation showed that the 226 Ra activity of the interstitial water is controlled by the Gypsum in acid treatment residues. In other hand in the alkaline treatment waters, the carbonates occur. The Ra retention is largely bound to the Fe and Mn oxy-hydroxides. (A.L.B.)

  18. Investigation of aluminum gate CMP in a novel alkaline solution

    International Nuclear Information System (INIS)

    Feng Cuiyue; Liu Yuling; Sun Ming; Zhang Wenqian; Zhang Jin; Wang Shuai

    2016-01-01

    Beyond 45 nm, due to the superior CMP performance requirements with the metal gate of aluminum in the advanced CMOS process, a novel alkaline slurry for an aluminum gate CMP with poly-amine alkali slurry is investigated. The aluminum gate CMP under alkaline conditions has two steps: stock polishing and fine polishing. A controllable removal rate, the uniformity of aluminum gate and low corrosion are the key challenges for the alkaline polishing slurry of the aluminum gate CMP. This work utilizes the complexation-soluble function of FA/O II and the preference adsorption mechanism of FA/O I nonionic surfactant to improve the uniformity of the surface chemistry function with the electrochemical corrosion research, such as OCP-TIME curves, Tafel curves and AC impedance. The result is that the stock polishing slurry (with SiO 2 abrasive) contains 1 wt.% H 2 O 2 ,0.5 wt.% FA/O II and 1.0 wt.% FA/O I nonionic surfactant. For a fine polishing process, 1.5 wt.% H 2 O 2 , 0.4 wt.% FA/O II and 2.0 wt.% FA/O I nonionic surfactant are added. The polishing experiments show that the removal rates are 3000 ± 50 Å/min and 1600 ± 60 Å/min, respectively. The surface roughnesses are 2.05 ± 0.128 nm and 1.59 ± 0.081 nm, respectively. A combination of the functions of FA/O II and FA/O I nonionic surfactant obtains a controllable removal rate and a better surface roughness in alkaline solution. (paper)

  19. Paleochemistry of Plio-Pleistocene Lake Turkana, Kenya. [Alkalinity

    Energy Technology Data Exchange (ETDEWEB)

    Cerling, T.

    1979-01-01

    The paleochemisry of Plio-Pleistocene Lake Turkana can be estimated by using the chemistry of lakes from the Eastern Rift of Africa as an analogue. Most modern East Africa lakes occupy closed basins; their chemistries follow an evaporation trend defined by the precipitation of certain mineral phases with increasing alkalinity. Estimates of paleoalkalinity can be used to closely estimate the chemical composition of ancient lakes. Three methods are used to estimate paleoalkalinity. Diatoms, molluscs, and fish have certain metabolic requirements that are dependent on pH, alkalinity, or calcium levels; thus fauna and flora can be used as paleoalkalinity indicators. Exchangeable cations on clay minerals can also be used because the relative concentrations of sodium and calcium in lake waters are related to alkalinity. Absence or presence of certain minerals also can serve as a paleoalkalinity indicator. Although the latter two techniques give estimates of paleoalkalinity that are averaged over several hundred or thousand years, their estimates agree with the instantaneous estimates based on biologic considerations. This study shows that the earliest lake phase was very fresh and contained until the end of the Kubi Algi Formation. The Lower Member of the Koobi Fora Formation is shown to have been a fresh- to brackish-water lake. From the beginning of Upper Member time (about 1.8 MY ago) to the present, the lake occupying the Turkana Depression has varied from a brackish lake that overflowed to a closed basin lake that fell below overflow level and whose alkalinity rose to about 200 meq/l.

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

    Science.gov (United States)

    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.

  1. Management of Purex spent solvents by the alkaline hydrolysis process

    International Nuclear Information System (INIS)

    Srinivas, C.; Manohar, Smitha; Vincent, Tessy; Wattal, P.K.; Theyyunni, T.K.

    1995-01-01

    Various treatment processes were evaluated on a laboratory scale for the management of the spent solvent from the extraction of nuclear materials. Based on the lab scale evaluation it is proposed to adopt the alkaline hydrolysis process as the treatment mode for the spent solvent. The process has advantages over the other processes in terms of simplicity, low cost and ease of disposal of the secondary waste generated. (author)

  2. The causes of alkalinity variations in the global surface ocean

    OpenAIRE

    Fry, Claudia Helen

    2016-01-01

    Human activities have caused the atmospheric concentration of carbon dioxide (CO2) to increase by 120 ppmv from pre-industrial times to 2014. The ocean takes up approximately a quarter of the anthropogenic CO2, causing ocean acidification (OA). Therefore it is necessary to study the ocean carbonate system, including alkalinity, to quantify the flux of CO2 into the ocean and understand OA. Since the 1970s, carbonate system measurements have been undertaken which can be analyzed to quantify the...

  3. Analysis of longitudinal variations in North Pacific alkalinity

    Science.gov (United States)

    Fry, C.; Tyrrell, T.; Achterberg, E. P.

    2016-02-01

    Carbon measurements in the ocean lack the coverage of physical measurements, so approximate alkalinity is predicted where data is unavailable. Surface alkalinity in the North Pacific is poorly characterised by predictive algorithms. Understanding the processes affecting alkalinity in this area can improve the equations. We investigated the causes of regional variations in alkalinity using GLODAPv2. We tested different hypotheses for the causes of three longitudinal phenomena in surface ocean values of Alk*, a tracer of calcium carbonate cycling. These phenomena are: (a) an increase in Alk* from east to west at 50°N, (b) an increase in Alk* from west to east at 30°N, and (c) a lack of a strong increase in Alk* from west to east in the equatorial upwelling area. We found that the most likely cause of higher Alk* on the western side of the subpolar North Pacific (at 50°N) is that denser isopycnals with higher Alk* lie at shallower depths on the western side than the eastern side. At 30°N, the main cause of higher Alk* on the eastern side of the basin is upwelling along the continental shelf of southwestern North America. Along the equator, our analyses suggest that the absence of a strong east-west trend is because the more intense upwelling on the eastern side of the basin does not, under normal conditions, lead to strong elevation of Alk*. However, surface Alk* is more strongly elevated in the eastern Equatorial Pacific during negative phases of the El-Nino-Southern Oscillation, probably because the upwelled water comes from greater depth at these times.

  4. Cationic Polymers Developed for Alkaline Fuel Cell Applications

    Science.gov (United States)

    2015-01-20

    into five categories: proton exchange membrane fuel cell ( PEMFC ), alkaline fuel cell (AFC), molten carbonate fuel cell (MCFC), solid oxide fuel...SOFC and PAFC belong to high temperature fuel cell, which can be applied in stationary power generation. PEMFC and AFC belong to low temperature fuel...function of the polymer electrolyte is to serve as electrolyte to transport ions between electrodes. PEMFC uses a polymer as electrolyte and works

  5. Exploring Alkaline Stable Organic Cations for Polymer Hydroxide Exchange Membranes

    Science.gov (United States)

    2015-04-29

    1   1.1.2   Proton exchange membrane fuel cells ( PEMFCs ) ......................... 3   1.1.3   Alkaline fuel cells (AFCs...160   xi LIST OF FIGURES Figure 1.1:   Schematic diagram of a PEMFC ...according to the type of electrolyte they use. Nowadays, there are six major types of fuel cells: proton-exchange membrane fuel cells ( PEMFCs ), hydroxide

  6. Biodegradation of alkaline lignin by Bacillus ligniniphilus L1

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Daochen; Zhang, Peipei; Xie, Changxiao; Zhang, Weimin; Sun, Jianzhong; Qian, Wei-Jun; Yang, Bin

    2017-02-21

    Background: Lignin is the most abundant aromatic biopolymer in the biosphere and it comprises up to 30% of plant biomass. Although lignin is the most recalcitrant component of the plant cell wall, still there are microorganisms able to decompose it or degrade it. Fungi are recognized as the most widely used microbes for lignin degradation. However, bacteria have also been known to be able to utilize lignin as a carbon or energy source. Bacillus ligniniphilus L1 was selected in this study due to its capability to utilize alkaline lignin as a single carbon or energy source and its excellent ability to survive in extreme environments. Results: To investigate the aromatic metabolites of strain L1 decomposing alkaline lignin, GC-MS analyze was performed and fifteen single phenol ring aromatic compounds were identified. The dominant absorption peak included phenylacetic acid, 4-hydroxy-benzoicacid, and vanillic acid with the highest proportion of metabolites resulting in 42%. Comparison proteomic analysis were carried out for further study showed that approximately 1447 kinds of proteins were produced, 141 of which were at least 2-fold up-regulated with alkaline lignin as the single carbon source. The up-regulated proteins contents different categories in the biological functions of protein including lignin degradation, ABC transport system, environmental response factors, protein synthesis and assembly, etc. Conclusions: GC-MS analysis showed that alkaline lignin degradation of strain L1 produced 15 kinds of aromatic compounds. Comparison proteomic data and metabolic analysis showed that to ensure the degradation of lignin and growth of strain L1, multiple aspects of cells metabolism including transporter, environmental response factors, and protein synthesis were enhanced. Based on genome and proteomic analysis, at least four kinds of lignin degradation pathway might be present in strain L1, including a Gentisate pathway, the benzoic acid pathway and the

  7. Characterization of palm fibers modified with alkaline solution

    International Nuclear Information System (INIS)

    Sipiao, Bryan L.S.; Goulart, Shane A.G.; Mulinari, Daniella R.; Souza Junior, Fernando G. de

    2011-01-01

    This work had the objective of to study one inexpensive and effective technique that enables the application of natural fibers from the Australian Royal Palm as reinforcement in polymer composites. The fibers treated with alkaline solution were characterized by infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) and had their data compared with the fiber in nature. Data showed that the treatment made on fibers surface was effective. (author)

  8. Medium modification of fragmentation functions

    International Nuclear Information System (INIS)

    Nezza, Pasquale Di

    2007-01-01

    Deep Inelastic Scattering is the cleanest process to investigate the space-time evolution of the hadronization. This was studied by the influence of the nuclear medium on lepto-production of hadrons at the Hermes experiment at DESY in semi-inclusive DIS of 27.6 GeV positrons off deuterium, nitrogen, krypton and xenon targets. The differential multiplicity for heavy targets relative to that of deuterium has been measured for the first time for various identified hadrons (φ + , φ - , φ 0 , k + , k - , p and anti-p) as a function of the virtual photon energy ?, the fraction z of this energy transferred to the hadron, and the hadron transverse momentum squared p 2 t . The distribution of the hadron transverse momentum is broadened towards high p 2 t in the nuclear medium, in a manner resembling the Cronin effect observed in collisions of heavy ions and protons with nuclei. The pt -broadening results give also important information about the pre-hadron formation time. Moreover, by studying the hadron attenuation of the leading and sub-leading hadrons, we report, for the first time, the possibility to better understand the hadron absorption and the energy loss contributions to the attenuation mechanism. (Author)

  9. Gravitational lensing in plasmic medium

    Energy Technology Data Exchange (ETDEWEB)

    Bisnovatyi-Kogan, G. S., E-mail: gkogan@iki.rssi.ru; Tsupko, O. Yu., E-mail: tsupko@iki.rssi.ru [Russian Academy of Sciences, Space Research Institute (Russian Federation)

    2015-07-15

    The influence of plasma on different effects of gravitational lensing is reviewed. Using the Hamiltonian approach for geometrical optics in a medium in the presence of gravity, an exact formula for the photon deflection angle by a black hole (or another body with a Schwarzschild metric) embedded in plasma with a spherically symmetric density distribution is derived. The deflection angle in this case is determined by the mutual combination of different factors: gravity, dispersion, and refraction. While the effects of deflection by the gravity in vacuum and the refractive deflection in a nonhomogeneous medium are well known, the new effect is that, in the case of a homogeneous plasma, in the absence of refractive deflection, the gravitational deflection differs from the vacuum deflection and depends on the photon frequency. In the presence of a plasma nonhomogeneity, the chromatic refractive deflection also occurs, so the presence of plasma always makes gravitational lensing chromatic. In particular, the presence of plasma leads to different angular positions of the same image if it is observed at different wavelengths. It is discussed in detail how to apply the presented formulas for the calculation of the deflection angle in different situations. Gravitational lensing in plasma beyond the weak deflection approximation is also considered.

  10. Unsaturated medium hydrocarbons pollution evaluation

    International Nuclear Information System (INIS)

    Di Luise, G.

    1991-01-01

    When the so called porous unsaturated medium, that's the vertical subsoil section between both the ground and water-table level, is interested by a hydrocarbons spill, the problem to evaluate the pollution becomes difficult: considering, essentially, the natural coexistence in it of two fluids, air and water, and the interactions between them. This paper reports that the problems tend to increase when a third fluid, the pollutant, immiscible with water, is introduced into the medium: a three-phases flow, which presents several analogies with the flow conditions present in an oil-reservoir, will be established. In such a situation, it would be very useful to handle the matter by the commonly used parameters in the oil reservoirs studies such as: residual saturation, relative permeability, phases mobility, to derive a first semiquantitative estimation of the pollution. The subsoil pollution form hydrocarbons agents is one of the worldwide more diffused causes of contamination: such events are generally referable to two main effects: accidental (oil pipeline breakdowns, e.g.), and continuous (underground tanks breaks, industrial plants leakages, e.g.)

  11. Is the intercloud medium pervasive

    International Nuclear Information System (INIS)

    Heiles, C.

    1980-01-01

    We consider the pervasiveness of the ''not strongly absorbing'' (NSA) H I gas, which is the intercloud medium in steady state theories of the interstellar medium. We study the question by analyzing wide emission components in nearby gas, and the absence of absorption components in distant gas. We conclude that the NSA material is deficient in the immediately local solar vicinity. In nearby regions it contains 38% of the interstellar H I; it is generally pervasive and often has internal motions which greatly increase its velocity dispersion above the 5 km s -1 minimum value. It contains large holes, perhaps ranging up to 400 pc diameter, which probably occupy 10--20% of the volume. In distant regions the NSA material seems to be pervasive outside 8 kpc galactic radius. For galactic radii between 8 and 10 kpc its thickness agrees with previous determinations of 370 pc for nearby regions. Outside 10 kpc the thickness increases dramatically. Inside 8 kpc there are no data

  12. Alkalinity and trophic state regulate aquatic plant distribution in Danish lakes

    DEFF Research Database (Denmark)

    Vestergaard, Ole Skafte; Sand-Jensen, Kaj

    2000-01-01

    distinct differences in the distribution of species and growth forms among the lakes. The lakes separated into five groups of characteristic species compositions. Alkalinity was the main factor responsible for the species distribution. Lakes of high alkalinity were dominated by vascular plants...... of the elodeid growth form, lakes of intermediate alkalinity contained a variety of elodeids and vascular plants of the isoetid growth form, while lakes of low alkalinity and low pH had several isoetids and bryophytes, but very few elodeids. Alkalinity is a close descriptor of the bicarbonate concentration...

  13. How Does the Medium Affect the Message?

    Science.gov (United States)

    Dommermuth, William P.

    1974-01-01

    This experimental comparison of the advertising effectiveness of television, movies, radio, and print finds no support for McLuhan's idea that television is a "cool" medium and movies are a "hot" medium. (RB)

  14. Porous poly(perfluorosulfonic acid) membranes for alkaline water electrolysis

    DEFF Research Database (Denmark)

    Aili, David; Hansen, Martin Kalmar; Andreasen, Jens Wenzel

    2015-01-01

    Poly(perfluorosulfonic acid) (PFSA) is one of a few polymer types that combine excellent alkali resistance with extreme hydrophilicity. It is therefore of interest as a base material in separators for alkaline water electrolyzers. In the pristine form it, however, shows high cation selectivity. T...... for the unmodified membrane. The technological feasibility was demonstrated by testing the membranes in an alkaline water electrolysis cell with encouraging performance.......Poly(perfluorosulfonic acid) (PFSA) is one of a few polymer types that combine excellent alkali resistance with extreme hydrophilicity. It is therefore of interest as a base material in separators for alkaline water electrolyzers. In the pristine form it, however, shows high cation selectivity...... and washed out and the obtained porous materials allowed for swelling to reach water contents up to λ=85 [H2O] [−SO3K]−1. After equilibration in 22 wt% aqueous KOH, ion conductivity of 0.2 S cm−1 was recorded for this membrane type at room temperature, which is significantly higher than 0.01 S cm−1...

  15. Alkaline autoclave leaching of refractory uranium-thorium minerals

    International Nuclear Information System (INIS)

    Milani, S. A.; Sam, S.

    2011-01-01

    This paper deals with the study of an innovative method for processing the Oman placer ores by alkaline leaching in ball mill autoclaves, where grinding and leaching of the refractory minerals take place simultaneously. This was followed by the selective separation of thorium and uranium from lanthanides by autoclave leaching of the hydroxide cake with ammonium carbonate-bicarbonate solutions. The introduced method is based on the fact that thorium and uranium form soluble carbonate complexes with ammonium carbonate, while lanthanides form sparingly soluble double carbonates. It was found that a complete alkaline leaching of Oman placer ores (98.0 P ercent ) was attained at 150 and 175 d egree C within 2.5 and 2h, respectively. Oman placer ores leaching was intensified and accelerated in a ball mill autoclaves as a result of the grinding action of steel balls, removal of the hydroxide layer covering ores grains and the continuous contact of fresh ore grains with alkaline solution. The study of selective carbonate processing of hydroxide cake with ammonium carbonate-bicarbonate solutions on autoclave under pressure revealed that the complete thorium recovery (97.5 P ercent ) with uranium recovery (90.8 P ercent ) and their separation from the lanthanides were attained at 70-80 d egree C during l-2h. The extraction of lanthanides in carbonate solution was low and did not exceed 4.6 P ercent .

  16. Alkaline phosphatase as a screening test for osteomalacia.

    Science.gov (United States)

    Chinoy, Muhammad Amin; Javed, Muhammad Imran; Khan, Alamzeb; Sadruddin, Nooruddin

    2011-01-01

    Vitamin D deficiency remains common in children and adults in Pakistan despite adequate sunlight exposure. Diagnosis in adults is usually delayed and is made following pathological fractures that result in significant morbidity. The objective of this study was to see whether Serum Alkaline Phosphatase levels could be used as a screening test for osteomalacia. The Study was conducted at Fatima Hospital, Baqai Medical University, Gadap, Karachi, between July 2002 and June 2005. Serum calcium levels are commonly used to screen patients suspected of osteomalacia, and raised serum alkaline phosphatase (SALP) is considered a diagnostic finding. We used SALP to screen patients who presented with back or non-specific aches and pain of more than six months duration. Three hundred thirty-four (334) patients were screened of which 116 (35%) had raised SALP. Osteomalacia was diagnosed in 92 (79.3%) of these 116 either by plain radiographs, bone biopsy or isotope bone scan. Fifty-four (53.4%) of the 101 cases had a normal level of serum calcium. Osteomalacia is likely to be missed if only serum calcium is used to screen patients. Serum Alkaline Phosphate should be used as the preferred method for screening these patients.

  17. Evaluation of electrolytic alkaline cleaners by evaporative-rate analysis

    International Nuclear Information System (INIS)

    Hamilton, C.B.

    1975-01-01

    A method has been developed by which electrolytic alkaline cleaners used in large volumes in steel mills can be evaluated for their ability to clean rolling oil from steel strip without the necessity of large-scale mill trials. The method is evaporative-rate analysis, which can be used to determine the relative amount of residual oil on steel strip after cleaning. The procedure consists in placing a droplet of a solution of a volatile, radioactive, carbon-14 tagged organic compound dissolved in a more volatile solvent, on the surface of the metal, where it forms a ternary solution with any oil on the surface. The amount of oil in this ternary solution affects the rate of evaporation of the tagged compound. The rate of evaporation, monitored by a Geiger-Mueller detector, is a measure of the cleanliness of the surface. A number of commercial alkaline cleaners, both solids and liquids, were evaluated over a range of concentrations. Results indicated that the effectiveness of commercial alkaline cleaners varies greatly, and is a function of the cleaner concentration, cleaner composition, and polarity of cleaning. The presence of antifoaming agents also affects cleaning ability. The results of this study indicate that evaporative-rate analysis is a rapid and effective method for evaluating cleaners

  18. Endurance test and evaluation of alkaline water electrolysis cells

    Science.gov (United States)

    Burke, K. A.; Schubert, F. H.

    1981-01-01

    Utilization in the development of multi-kW low orbit power systems is discussed. The following technological developments of alkaline water electrolysis cells for space power application were demonstrated: (1) four 92.9 cm2 single water electrolysis cells, two using LST's advanced anodes and two using LST's super anodes; (2) four single cell endurance test stands for life testing of alkaline water electrolyte cells; (3) the solid performance of the advanced electrode and 355 K; (4) the breakthrough performance of the super electrode; (5) the four single cells for over 5,000 hours each significant cell deterioration or cell failure. It is concluded that the static feed water electrolysis concept is reliable and due to the inherent simplicity of the passive water feed mechanism coupled with the use of alkaline electrolyte has greater potential for regenerative fuel cell system applications than alternative electrolyzers. A rise in cell voltage occur after 2,000-3,000 hours which was attributed to deflection of the polysulfone end plates due to creepage of the thermoplastic. More end plate support was added, and the performance of the cells was restored to the initial performance level.

  19. Evaluation of hydraulic conductivities of bentonite and rock under hyper alkaline and nitrate conditions

    International Nuclear Information System (INIS)

    Iriya, K.; Fujii, K.; Kubo, H.

    2002-02-01

    The chemical conditions of TRU waste repository were estimated as alkaline conditions effected by cementitious materials. And, some TRU wastes include soluble nitrate salt, we have to consider the repository conditions might be high ionic strength condition leaching of nitrate salt. In this study, experimental studies were carried out to evaluate hydraulic conductivities of bentonite and rock under hyper alkaline and nitrate conditions. The followings results were obtained for bentonite. 1) In the immersion experiments of bentonite in hyper alkaline fluids with and without nitrate, the disappearance of montmorillonite of bentonite was observed and CSH formation was found after 30 days. In hyper alkaline fluid with nitrate, minerals at θ=37 nm by XRD was identified. 2) Significant effects of hyper alkaline on hydraulic conductivity of compacted bentonite were not observed. However, hydraulic conductivities of hyper alkaline fluid with nitrate and ion exchanged bentonite increased. In hyper alkaline with nitrate, more higher hydraulic conductivities of exchanged bentonite were measured. The followings results were obtained for rock. 1) In the immersion experiments of crushed tuff in hyper alkaline fluids with and without nitrate, CSH and CASH phases were observed. 2) The hydraulic conductivity of tuff in hyper alkaline fluids decreased gradually. Finally, hyper alkaline flow in tuff stopped after 2 months and hyper alkaline flow with nitrate stopped shorter than without nitrate. In the results of analysis of tuff after experiment, we could identified secondary minerals, but we couldn't find the clogging evidence of pores in tuff by secondary minerals. (author)

  20. Production and partial characterization of alkaline protease from bacillus subtilis mutant induced by gamma radiation

    International Nuclear Information System (INIS)

    Ibrahim, H.M.M.; Bashandy, A.S.

    2010-01-01

    Fourteen bacterial isolates belonging to B.subtilis were locally isolated from soil and screened for alkaline protease production. Only one strain, the highly potent one, was selected as alkaline protease producer and subjected to further studies to optimize its production. Alkaline protease production was maximum at 35 degree C after 72 h of incubation and at ph 10.0. molasses as a carbon source and combination of peptone and yeast extract as a nitrogen source enhanced greatly alkaline protease production. The mutant strain induced by gamma radiation showed higher alkaline protease production by 1.97 fold as compared with the parent strain. The alkaline protease enzyme was active at 40 degree C and ph 10. It was compatible with many commercial detergents and showed high stability (84 %) of its original activity with Ariel detergent. Moreover, alkaline protease enhanced the washing performance, and retained 95 % of its activity in the formulated dry powder.

  1. 27 CFR 19.914 - Medium plants.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Medium plants. 19.914... OF THE TREASURY LIQUORS DISTILLED SPIRITS PLANTS Distilled Spirits For Fuel Use Permits § 19.914 Medium plants. Any person wishing to establish a medium plant shall make application for and obtain in...

  2. Mapping of moveout in a TTI medium

    KAUST Repository

    Stovas, A.; Alkhalifah, Tariq Ali

    2012-01-01

    To compute moveout in a transversely isotropic medium with tilted symmetry axis is a very complicated problem. We propose to split this problem into two parts. First, to compute the moveout in a corresponding VTI medium. Second, to map the computed moveout to a TTI medium.

  3. Role of dust alkalinity in acid mobilization of iron

    Directory of Open Access Journals (Sweden)

    A. Ito

    2010-10-01

    Full Text Available Atmospheric processing of mineral aerosols by acid gases (e.g., SO2, HNO3, N2O5, and HCl may play a key role in the transformation of insoluble iron (Fe in the oxidized or ferric (III form to soluble forms (e.g., Fe(II, inorganic soluble species of Fe(III, and organic complexes of iron. On the other hand, mineral dust particles have a potential of neutralizing the acidic species due to the alkaline buffer ability of carbonate minerals (e.g., CaCO3 and MgCO3. Here we demonstrate the impact of dust alkalinity on the acid mobilization of iron in a three-dimensional aerosol chemistry transport model that includes a mineral dissolution scheme. In our model simulations, most of the alkaline dust minerals cannot be entirely consumed by inorganic acids during the transport across the North Pacific Ocean. As a result, the inclusion of alkaline compounds in aqueous chemistry substantially limits the iron dissolution during the long-range transport to the North Pacific Ocean: only a small fraction of iron (<0.2% dissolves from hematite in the coarse-mode dust aerosols with 0.45% soluble iron initially. On the other hand, a significant fraction of iron (1–2% dissolves in the fine-mode dust aerosols due to the acid mobilization of the iron-containing minerals externally mixed with carbonate minerals. Consequently, the model quantitatively reproduces higher iron solubility in smaller particles as suggested by measurements over the Pacific Ocean. It implies that the buffering effect of alkaline content in dust aerosols might help to explain the inverse relationship between aerosol iron solubility and particle size. We also demonstrate that the iron solubility is sensitive to the chemical specification of iron-containing minerals in dust. Compared with the dust sources, soluble iron from combustion sources contributes to a relatively marginal effect for deposition of soluble iron over the North

  4. Medium-size nuclear plants

    International Nuclear Information System (INIS)

    Vogelweith, L.; Lavergne, J.C.; Martinot, G.; Weiss, A.

    1977-01-01

    CEA (TECHNICATOME) has developed a range of pressurized water reactors of the type ''CAS compact'' which are adapted to civil ship propulsion, or to electric power production, combined possibly with heat production, up to outputs equivalent to 125 MWe. Nuclear plants equipped with these reactors are suitable to medium-size electric networks. Among the possible realizations, two types of plants are mentioned as examples: 1) Floating electron-nuclear plants; and 2) Combined electric power and desalting plants. The report describes the design characteristics of the different parts of a 125 MWe unit floating electro-nuclear plant: nuclear steam system CAS 3 G, power generating plant, floating platform for the whole plant. The report gives attention to the different possibilities according to site conditions (the plant can be kept floating, in a natural or artificial basin, it can be put aground, ...) and to safety and environment factors. Such unit can be used in places where there is a growing demand in electric power and fresh water. The report describes how the reactor, the power generating plant and multiflash distillation units of an electric power-desalting plant can be combined: choice of the ratio water output/electric power output, thermal cycle combination, choice of the gain ratio, according to economic considerations, and to desired goal of water output. The report analyses also some technical options, such as: choice of the extraction point of steam used as heat supply of the desalting station (bleeding a condensation turbine, or recovering steam at the exhaust of a backpressure turbine), design making the system safe. Lastly, economic considerations are dealt with: combining the production of fresh water and electric power provides usually a much better energy balance and a lower cost for both products. Examples are given of some types of installations which combine medium-size reactors with fresh water stations yielding from 10000 to 120000 m 3 per day

  5. Optimizing production of hydroxyapatite from alkaline residue for removal of Pb{sup 2+} from wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Yubo; Wang, YanPeng; Sun, Xiuyun, E-mail: sunxyun@njust.edu.cn; Li, Jiansheng; Shen, Jinyou; Han, Weiqing; Liu, Xiaodong; Wang, Lianjun, E-mail: wanglj@njust.edu.cn

    2014-10-30

    Highlights: • The solid waste from Soda Ash Plants was firstly converted into the high-efficiency adsorbent (O-HAP). • The response surface methodology was used to optimize the preparation conditions of O-HAP. • The O-HAP showed excellent immobilization ability for Pb{sup 2+} in both aqueous and soil medium. • The maximum adsorption capacity for Pb{sup 2+} (1429 mg/g) was considerably greater than other familiar adsorbents. - Abstract: Alkaline residue, a common solid waste generated from the ammonia-soda process for the production of soda ash, has been converted into hydroxyapatite for Pb{sup 2+} removal from wastewater. Response surface methodology was used to optimize the preparation conditions which were Ca/P (molar ratio), reaction temperature and reaction time, with the Pb{sup 2+} removal percentage as targeted response. The optimum conditions were identified to be Ca/P of 1.29, reaction temperature of 165.87 °C and reaction time of 14.5 h. Batch tests were conducted to evaluate the adsorption performance of optimum adsorbent (O-HAP), and the adsorption data were analyzed with different kinetic and isotherm models. The results showed that the pseudo-second order kinetic model and Langmuir isotherm model could best describe the adsorption of Pb{sup 2+} on O-HAP. The maximum adsorption capacity calculated from Langmuir equation was 1429 mg/g, which was greater than other familiar adsorbents. The MINTEQ results predicted that the formation of different Pb precipitates was the main mechanism in Pb{sup 2+} removal process, which was in good agreement with the kinetic and thermodynamic studies and were confirmed by the SEM-EDS and XRD analysis. In addition to aqueous medium, the O-HAP also could efficiently immobilize Pb{sup 2+} from contaminated soil.

  6. Neoproterozoic alkaline magmatism in Ilha do Cardoso, southeastern coast of Sao Paulo State, Brazil

    International Nuclear Information System (INIS)

    Weber, Werner; Basei, Miguel A.S.; Siga Junior, Oswaldo; Sato, Kei

    2001-01-01

    This work focuses on the geology and geochronology of rocks cropping out on Cardoso Island, on the southeastern coast of Sao Paulo State, close to the boundary with Parana State. The island, with an area of about 151 km 2 is a protected area administered by the Forest Institute of the Secretariat for the Environment of the State of Sao Paulo. It is mountainous, with a peak at 814 m, and is covered by dense Atlantic Forest vegetation. The island is made up mainly of an igneous complex with light grey leucocratic, inequigranular, medium to coarse-grained syenites. The Tres Irmaos Syenite (STI), composed of pyroxene, hornblende, and perthitic to mesoperthitic microcline, predominates has magmatic flow structures, and it cut by the pinkish grey, leucocratic medium-grained Cambriu alkali-feldspar granites (GC). Geochemical analysis of STI and GC demonstrate their metaluminous alkaline nature and late orogenic to anorogenic character. The bodies formed between 620 and 570 Ma according to U-Pb dating of zircons and cooled between 597 and 531 Ma (K-Ar in amphiboles). Whole rock Sm-Nd analyses yield Meso- and Paleoproterozoic TDM ages (1,500 - 2,200 Ma). A belt of low-grade metasedimentary rocks occurs in the northern part of the island. Quartz schist, quartz-mica schist and mica-quartz schist, often-containing andalusite and cordierite, predominate. Geochemical and geochronological data suggest that the sources of the metasediments were continental arc andesites of whose protoliths separated from the mantle between 1,800 and 2,200 Ma during the Paleoproterozoic. These metasediments probably continue on the continent in the Taquari region and extend southwards in narrow strips between the granitoids of the Paranagua Domain. (author)

  7. Palladium and palladium-tin supported on multi wall carbon nanotubes or carbon for alkaline direct ethanol fuel cell

    Science.gov (United States)

    Geraldes, Adriana Napoleão; Furtunato da Silva, Dionisio; Martins da Silva, Júlio César; Antonio de Sá, Osvaldo; Spinacé, Estevam Vitório; Neto, Almir Oliveira; Coelho dos Santos, Mauro

    2015-02-01

    Pd and PdSn (Pd:Sn atomic ratios of 90:10), supported on Multi Wall Carbon Nanotubes (MWCNT) or Carbon (C), are prepared by an electron beam irradiation reduction method. The obtained materials are characterized by X-Ray diffraction (XRD), Energy dispersive X-ray analysis (EDX), Transmission electron Microscopy (TEM) and Cyclic Voltammetry (CV). The activity for ethanol electro-oxidation is tested in alkaline medium, at room temperature, using Cyclic Voltammetry and Chronoamperometry (CA) and in a single alkaline direct ethanol fuel cell (ADEFC), in the temperature range of 60-90 °C. CV analysis finds that Pd/MWCNT and PdSn/MWCNT presents onset potentials changing to negative values and high current values, compared to Pd/C and PdSn/C electrocatalysts. ATR-FTIR analysis, performed during the CV, identifies acetate and acetaldehyde as principal products formed during the ethanol electro-oxidation, with low conversion to CO2. In single fuel cell tests, at 85 °C, using 2.0 mol L-1 ethanol in 2.0 mol L-1 KOH solutions, the electrocatalysts supported on MWCNT, also, show higher power densities, compared to the materials supported on carbon: PdSn/MWCNT, presents the best result (36 mW cm-2). The results show that the use of MWCNT, instead of carbon, as support, plus the addition of small amounts of Sn to Pd, improves the electrocatalytic activity for Ethanol Oxidation Reaction (EOR).

  8. High performance nano-Ni/Graphite electrode for electro-oxidation in direct alkaline ethanol fuel cells

    Science.gov (United States)

    Soliman, Ahmed B.; Abdel-Samad, Hesham S.; Abdel Rehim, Sayed S.; Ahmed, Mohamed A.; Hassan, Hamdy H.

    2016-09-01

    Ni/Graphite electrocatalysts (Ni/G) are successfully prepared through electrodeposition of Ni from acidic (pH = 0.8) and feebly acidic (pH = 5.5) aqueous Ni (II) baths. The efficiencies of such electrodes are investigated as anodes for direct alkaline ethanol fuel cells through their ethanol electrooxidation cyclic voltammetric (CV) response in alkaline medium. A direct proportionality between the amount of the electrodeposited Ni and its CV response is found. The amounts of the deposited Ni from the two baths are recorded using the Electrochemical Quartz Crystal Microbalance (eQCM). The Ni/G electrodes prepared from the feebly acidic bath show a higher electrocatalytic response than those prepared from the acidic bath. Surface morphology of the Ni particles electrodeposited from feebly acidic bath appears in a nano-scale dimension. Various electrochemical experiments are conducted to confirm that the Ni/G ethanol electrooxidation CV response greatly depends on the pH rather than nickel ion concentration of the deposition bath. The eQCM technique is used to detect the crystalline phases of nickel as α-Ni(OH)2/γ-NiOOH and β-Ni(OH)2/β-NiOOH and their in-situ inter-transformations during the potentiodynamic polarization.

  9. Tattoo: a multifaceted medium of communication

    Directory of Open Access Journals (Sweden)

    Christian Wymann

    2010-11-01

    Full Text Available This article suggests the systems theoretical distinction of form/medium as a useful tool for distinguishing social phenomena that might look as if they stem from the same process. This is shown to be the case for the tattoo and tattooing. The tattoo is conceived as a medium of communication through which different forms of communication emerge. Tattooing is one of these forms of communication that shapes the medium in a particular way. The current article sheds a special light on its intricate, communicational constellation, for which the concept of parallax is suggested. Law, medicine and cosmetics as other forms of communication use the medium of tattoo in their own way as well. The form/medium distinction allows us to grasp these different forms of communication, while it shows that they share the tattoo as medium. The article’s ultimate goal is to illustrate that the tattoo figures as a multifaceted medium of communication.

  10. Evaluation of a novel thermo-alkaline Staphylococcus aureus lipase for application in detergent formulations

    Directory of Open Access Journals (Sweden)

    Abir Ben Bacha

    2018-03-01

    Full Text Available An extracellular lipase of a newly isolated S. aureus strain ALA1 (SAL4 was purified from the optimized culture medium. The SAL4 specific activity determined at 60 °C and pH 12 by using olive oil emulsion or TC4, reached 7215 U/mg and 2484 U/mg, respectively. The 38 NH2-terminal amino acid sequence of the purified enzyme starting with two extra amino acid residues (LK was similar to known staphylococcal lipase sequences. This novel lipase maintained almost 100% and 75% of its full activity in a pH range of 4.0–12 after a 24 h incubation or after 0.5 h treatment at 70 °C, respectively. Interestingly, SAL4 displayed appreciable stability toward oxidizing agents, anionic and non-ionic surfactants in addition to its compatibility with several commercial detergents. Overall, these interesting characteristics make this new lipase promising for its application in detergent industry. Keywords: Staphylococcus aureus lipase, Purification, Characterization, Thermo-alkaline, Detergent-stable

  11. Tolerance of Chemoorganotrophic Bioleaching Microorganisms to Heavy Metal and Alkaline Stresses

    Science.gov (United States)

    Monballiu, Annick; Cardon, Nele; Tri Nguyen, Minh; Cornelly, Christel; Meesschaert, Boudewijn; Chiang, Yi Wai

    2015-01-01

    The bioleaching potential of the bacterium Bacillus mucilaginosus and the fungus Aspergillus niger towards industrial residues was investigated by assessing their response towards various heavy metals (including arsenic, cadmium, cobalt, chromium, nickel, lead, and zinc) and elevated pH. The plate diffusion method was performed for each metal to determine the toxicity effect. Liquid batch cultures were set up for more quantitative evaluation as well as for studying the influence of basicity. Growth curves were prepared using bacterial/fungal growth counting techniques such as plate counting, optical density measurement, and dry biomass determination. Cadmium, nickel, and arsenite had a negative influence on the growth of B. mucilaginosus, whereas A. niger was sensitive to cadmium and arsenate. However, it was shown that growth recovered when microorganisms cultured in the presence of these metals were inoculated onto metal-free medium. Based on the findings of the bacteriostatic/fungistatic effect of the metals and the adaptability of the microorganisms to fairly elevated pH values, it is concluded that both strains have potential applicability for further research concerning bioleaching of alkaline waste materials. PMID:26236176

  12. Colorimetric determination of alkaline phosphatase as indicator of mammalian feces in corn meal: collaborative study.

    Science.gov (United States)

    Gerber, H

    1986-01-01

    In the official method for rodent filth in corn meal, filth and corn meal are separated in organic solvents, and particles are identified by the presence of hair and a mucous coating. The solvents are toxic, poor separation yields low recoveries, and fecal characteristics are rarely present on all fragments, especially on small particles. The official AOAC alkaline phosphatase test for mammalian feces, 44.181-44.184, has therefore been adapted to determine the presence of mammalian feces in corn meal. The enzyme cleaves phosphate radicals from a test indicator/substrate, phenolphthalein diphosphate. As free phenolphthalein accumulates, a pink-to-red color develops in the gelled test agar medium. In a collaborative study conducted to compare the proposed method with the official method for corn meal, 44.049, the proposed method yielded 45.5% higher recoveries than the official method. Repeatability and reproducibility for the official method were roughly 1.8 times more variable than for the proposed method. The method has been adopted official first action.

  13. Water miscible mono alcohols' effect on the proteolytic performance of Bacillus clausii serine alkaline protease.

    Science.gov (United States)

    Duman, Yonca Avci; Kazan, Dilek; Denizci, Aziz Akin; Erarslan, Altan

    2014-01-01

    In this study, our investigations showed that the increasing concentrations of all examined mono alcohols caused a decrease in the Vm, kcat and kcat/Km values of Bacillus clausii GMBE 42 serine alkaline protease for casein hydrolysis. However, the Km value of the enzyme remained almost the same, which was an indicator of non-competitive inhibition. Whereas inhibition by methanol was partial non-competitive, inhibition by the rest of the alcohols tested was simple non-competitive. The inhibition constants (KI) were in the range of 1.32-3.10 M, and the order of the inhibitory effect was 1-propanol>2-propanol>methanol>ethanol. The ΔG(≠) and ΔG(≠)E-T values of the enzyme increased at increasing concentrations of all alcohols examined, but the ΔG(≠)ES value of the enzyme remained almost the same. The constant Km and ΔG(≠)ES values in the presence and absence of mono alcohols indicated the existence of different binding sites for mono alcohols and casein on enzyme the molecule. The kcat of the enzyme decreased linearly by increasing log P and decreasing dielectric constant (D) values, but the ΔG(≠) and ΔG(≠)E-T values of the enzyme increased by increasing log P and decreasing D values of the reaction medium containing mono alcohols.

  14. Fluorescent Biosensor for Phosphate Determination Based on Immobilized Polyfluorene-Liposomal Nanoparticles Coupled with Alkaline Phosphatase.

    Science.gov (United States)

    Kahveci, Zehra; Martínez-Tomé, Maria José; Mallavia, Ricardo; Mateo, C Reyes

    2017-01-11

    This work describes the development of a novel fluorescent biosensor based on the inhibition of alkaline phosphatase (ALP). The biosensor is composed of the enzyme ALP and the conjugated cationic polyfluorene HTMA-PFP. The working principle of the biosensor is based on the fluorescence quenching of this polyelectrolyte by p-nitrophenol (PNP), a product of the hydrolysis reaction of p-nitrophenyl phosphate (PNPP) catalyzed by ALP. Because HTMA-PFP forms unstable aggregates in buffer, with low fluorescence efficiency, previous stabilization of the polyelectrolyte was required before the development of the biosensor. HTMA-PFP was stabilized through its interaction with lipid vesicles to obtain stable blue-emitting nanoparticles (NPs). Fluorescent NPs were characterized, and the ability to be quenched by PNP was evaluated. These nanoparticles were coupled to ALP and entrapped in a sol-gel matrix to produce a biosensor that can serve as a screening platform to identify ALP inhibitors. The components of the biosensor were examined before and after sol-gel entrapment, and the biosensor was optimized to allow the determination of phosphate ion in aqueous medium.

  15. Experimental Study of Enhancing Oil Recovery with Weak Base Alkaline/Surfactant/Polymer

    Directory of Open Access Journals (Sweden)

    Dandan Yin

    2017-01-01

    Full Text Available Na2CO3 was used together with surfactant and polymer to form the Alkaline/Surfactant/Polymer (ASP flooding system. Interfacial tension (IFT and emulsification of Dagang oil and chemical solutions were studied in the paper. The experiment results show that the ASP system can form super-low interfacial tension with crude oil and emulsified phase. The stability of the emulsion is enhanced by the Na2CO3, surfactant, and the soap generated at oil/water contact. Six core flooding experiments are conducted in order to investigate the influence of Na2CO3 concentration on oil recovery. The results show the maximum oil recovery can be obtained with 0.3 wt% surfactant, 0.6 wt% Na2CO3, and 2000 mg/L polymer. In a heterogeneous reservoir, the ASP flooding could not enhance the oil recovery by reducing IFT until it reaches the critical viscosity, which indicates expanding the sweep volume is the premise for reducing IFT to enhance oil recovery. Reducing or removing the alkali from ASP system to achieve high viscosity will reduce oil recovery because of the declination of oil displacement efficiency. Weak base ASP alkali can ensure that the whole system with sufficient viscosity can start the medium and low permeability layers and enhance oil recovery even if the IFT only reaches 10−2 mN/m.

  16. Influence of medium components on the expression of recombinant lipoproteins in Escherichia coli.

    Science.gov (United States)

    Tseng, Chi-Ling; Leng, Chih-Hsiang

    2012-02-01

    Bacterial lipoproteins are crucial antigens for protective immunity against bacterial pathogens. Expression of exogenous lipoproteins in Escherichia coli at high levels is thought to be an extremely difficult endeavor because it frequently results in incomplete or absent lipid modification. Previously, we identified a fusion sequence (D1) from a Neisseria meningitidis lipoprotein that induced a non-lipidated protein, E3 (the domain III of the dengue virus envelope protein), to become lipidated. However, without optimizing the growth conditions, some of the D1-fusion proteins were not lipidated. Here, we report the influence of medium components on the expression of recombinant lipoproteins in E. coli. For high-level expression of mature lipoproteins in the C43 (DE3) strain, M9 medium was better than M63 and the rich medium. Furthermore, we analyzed the influence of other media factors (including nitrogen and carbon sources, phosphate, ferrous ions, calcium, magnesium, and pH) on the levels of lipoprotein expression. The results showed that excess nitrogen sources and phosphate in M9 medium could increase the amount of immature lipoproteins, and glucose was a better carbon source than glycerol for expressing mature lipoproteins. We also found that lipoproteins tended to be completely processed in the alkaline environment, even in the nutrient-rich medium. Additional constructs expressing different immunogens or lipid signal peptides as targets were also utilized, demonstrating that these targets could be expressed as completely mature lipoproteins in the M9 medium but not in the rich medium. Our results provide the useful information for expressing mature exogenous lipoproteins in E. coli.

  17. Decolorization of humic acids and alkaline lignin derivative by an anamorphic Bjerkandera adusta E59 strain isolated from soil

    Energy Technology Data Exchange (ETDEWEB)

    Kornillowicz-Kowalska, T.; Ginalska, G.; Belcarz, A.; Iglik, H. [University of Life Sciences, Lublin (Poland). Dept. of Microbiology

    2008-07-01

    An anamorphic Bjerkandera adusta R59 strain, isolated from soil, was found to decolorize post-industrial lignin alkaline fraction, humic acids isolated from two kinds of soil and from brown coal. The drop of methoxyphenolic compound levels in liquid B. adusta cultures containing lignin or humic acids was correlated with decolorization of studied biopolymers, which suggests their partial biodegradation. It was shown that this process was Coupled with the induction of secondary metabolism (idiophase), and highest peroxidase activity in culture medium and appearance of aerial mycelium. Decolorization of lignin and humic acids from lessive soil and brown coal depended on glucose presence (cometabolism). Decolorization of humic acid from chernozem was related partially to adsorption by fungal mycelium.

  18. Hydrophilic cobalt sulfide nanosheets as a bifunctional catalyst for oxygen and hydrogen evolution in electrolysis of alkaline aqueous solution.

    Science.gov (United States)

    Zhu, Mingchao; Zhang, Zhongyi; Zhang, Hu; Zhang, Hui; Zhang, Xiaodong; Zhang, Lixue; Wang, Shicai

    2018-01-01

    Hydrophilic medium and precursors were used to synthesize a hydrophilic electro-catalyst for overall water splitting. The cobalt sulfide (Co 3 S 4 ) catalyst exhibits a layered nanosheet structure with a hydrophilic surface, which can facilitate the diffusion of aqueous substrates into the electrode pores and towards the active sites. The Co 3 S 4 catalyst shows excellent bifunctional catalytic activity for both the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in alkaline solution. The assembled water electrolyzer based on Co 3 S 4 exhibits better performance and stability than that of Pt/C-RuO 2 catalyst. Thereforce the hydrophilic Co 3 S 4 is a highly promising bifunctional catalyst for the overall water splitting reaction. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Medium-Based Design: Extending a Medium to Create an Exploratory Learning Environment

    Science.gov (United States)

    Rick, Jochen; Lamberty, K. K.

    2005-01-01

    This article introduces "medium-based" design -- an approach to creating "exploratory learning environments" using the method of "extending a medium". First, the characteristics of exploratory learning environments and medium-based design are described and grounded in related work. Particular attention is given to "extending a medium" --…

  20. A Revisit to the Corrosion Inhibition of Aluminum in Aqueous Alkaline Solutions by Water-Soluble Alginates and Pectates as Anionic Polyelectrolyte Inhibitors

    Directory of Open Access Journals (Sweden)

    Refat Hassan

    2013-01-01

    Full Text Available The corrosion behavior of aluminum (Al in alkaline media in presence of some natural polymer inhibitors has been reinvestigated. The inhibition action of the tested inhibitors was found to obey both Langmuir and Freundlich isotherms models. The inhibition efficiency was found to increase with increasing the inhibitors concentration and decrease with increasing the temperature, suggesting physical adsorption mechanism. Factors such as the concentration and geometrical structure of the inhibitor, concentration of the corrosive medium, and temperature affecting the corrosion rates were examined. The kinetic parameters were evaluated, and a suitable corrosion mechanism consistent with the kinetic results obtained is suggested and discussed.

  1. Sintering-alkaline processing of borosilicate ores of Tajikistan

    International Nuclear Information System (INIS)

    Nazarov, F.A.

    2018-01-01

    The aim of the work is to study the processes of decomposition of boron-containing ore by sintering with NaOH, finding the optimal parameters of the decomposition process, studying the kinetics of processes and developing the technological foundations for ore processing. The processes of borosilicate ore processing were studied by sintering with NaOH. Possible mechanisms of chemical reactions of the process of sintering-alkaline decomposition of boron-containing ore are established, the results of which are substantiated by physicochemical methods of analysis. A principal technological scheme for processing of borosilicate ores by a sintering-alkaline method has been developed. In the first chapter, data on alkaline and caking processes for processing boron-containing and aluminium comprising raw materials are available in the literature. Based on this, the directions of our own research are outlined. The second chapter is devoted to the study of the chemical and mineralogical compositions of borosilicate ores and their concentrates with the help of X-ray phase and chemical analysis methods, the stoichiometric calculation of the formation of aluminum, iron, and boron salts has been carried out, and a thermodynamic analysis of the processes of sintering borosilicate ores with alkali has been considered. The third chapter presents the results of a study of sintering-alkaline method of processing of initial borosilicate ore of the Ak-Arkhar Deposit and its concentrate without calcination and after calcination. The kinetics of sintering of borosilicate ores with sodium hydroxide was studied. The optimal conditions of borosilicate ore sintering before and after the preliminary calcination with alkali were determined. Optimal parameters of the sintering process have been found: sintering temperature 800-8500 deg C, duration of the process - 60 minutes, mass ratio of NaOH to raw materials 2: 1. The conditions for sintering of borosilicate concentrate with alkali have been

  2. Dreams of a New Medium

    Directory of Open Access Journals (Sweden)

    Aden Evens

    2009-01-01

    Full Text Available Problematic at best, the desire for a transparent interface nevertheless drives much of digital culture and technology. But not the Web; or at least, not Web 1.0. Thoroughly commercialized, comfortably parsed into genres, serving billions of pages of predigested content to passive consumers, the World Wide Web as developed in the '90s unabashedly embraces its role as medium. While so many digital technologies work to hide their mediacy--drawing in the user with a total simulated sensorium, dematerializing the resistances of size and weight, untangling the knots of cables tying user to machine and machine to cubicle, minimizing the interface--Web 1.0 proudly clings to the browser as a glaring reminder of its medial character. While Web 2.0 has not forsaken the browser altogether, it nevertheless seems to offer a different sort of mediation. Arising alongside the atomization of browser functions, the ubiquitization of connectivity, and the coincidence of producer and user, Web 2.0 retains the form of a medium while reaching for the experiential logic of immediacy. This is not the immediacy of the transparent interface; rather, Web 2.0 effects an immediate relationship between the individual and culture. The interface does not disappear, but its mediacy is subsumed under the general form of cultural participation. Focusing on the "version upgrade" from Web 1.0 to 2.0, this essay will explore the implications for mediacy of this transition, noting that the fantasy of immediacy which drives Web 2.0 is layered and complex. The typical account of immediacy proposes to eliminate the interface and so construct a virtual reality (VR. But Web 2.0 mostly sidesteps the virtual, propelled instead by a fantasy of intuition in which the Web already knows what you want because it is you. Crucially, fantasies about the digital are effective: the computer's futurity inhabits our world, finding its expression in politics, advertising, budgeting, strategic planning

  3. Novel inorganic materials for polymer electrolyte and alkaline fuel cells

    Science.gov (United States)

    Tadanaga, Kiyoharu

    2012-06-01

    Inorganic materials with high ionic conductivity must have big advantages for the thermal and long term stability when the materials are used as the electrolyte of fuel cells. In the present paper, novel ionic conductive inorganic materials for polymer electrolyte fuel cells (PEFCs) and all solid state alkaline fuel cells (AFCs) that have been developed by our group have been reviewed. PEFCs which can operate in temperature range from 100 to 200 °C are intensively studied because of some advantages such as reduction of CO poisoning of Pt catalyst and acceleration of electrode reactions. We showed that the fuel cells using the composite membranes prepared from phosphosilicate gel powder and polyimide precursor can operate in the temperature range from 30 to 180 °C. We also found that the inorganic-organic hybrid membranes with acid-base pairs from 3-aminopropyl triethoxy silane and H2SO4 or H3PO4 show high proton conductivity under dry atmosphere, and the membranes are thermally stable at intermediate temperatures. On the other hand, because the use of noble platinum is the serious problem for the commercialization of PEFCs and because oxidation reactions are usually faster than those of acid-type fuel cells, alkaline type fuel cells, in which a nonplatinum catalyst can be used, are attractive. Recently, we have proposed an alkaline-type direct ethanol fuel cell (DEFC) using a natural clay electrolyte with non-platinum catalysts. So-called hydrotalcite clay, Mg-Al layered double hydroxide intercalated with CO32- (Mg-Al CO32- LDH), has been proved to be a hydroxide ion conductor. An alkalinetype DEFC using Mg-Al CO32- LDH as the electrolyte and aqueous solution of ethanol and potassium hydroxide as a source of fuel exhibited excellent electrochemical performance.

  4. Blue photoluminescence in Ti-doped alkaline-earth stannates

    International Nuclear Information System (INIS)

    Yamashita, Takahiro; Ueda, Kazushige

    2007-01-01

    Blue photoluminescence properties of Ti-doped alkaline-earth stannates, A 2 (Sn 1- x Ti x )O 4 (A=Ca, Sr, Ba) (x=0.005-0.15), were examined at room temperature. These stannates showed intense broad emission bands peaking at 445 nm for Ca 2 SnO 4 , at 410 nm for Sr 2 SnO 4 , and at 425 nm for Ba 2 SnO 4 under UV excitation. Emission intensities were relatively insensitive to Ti concentration and no sharp concentration quenching was observed. Mixing alkaline-earth ions in the crystal structures did not increase the emission intensities in the A 2 (Sn 1- x Ti x )O 4 system. The excitation spectra of these stannates exhibited broad bands just below the fundamental absorption edges, implying that luminescence centers do not consist of the component elements in the host materials. It was suggested that the isolated TiO 6 complexes are possible luminescence centers in these materials, as previously proposed in other Ti-doped stannates such as Mg 2 SnO 4 and Y 2 Sn 2 O 7 . - Graphical abstract: Blue photoluminescence properties of Ti-doped alkaline-earth stannates, A 2 (Sn 1- x Ti x )O 4 (A=Ca, Sr, Ba) (x=0.005-0.15), were examined at room temperature. These stannates showed intense broad emission bands peaking at 445 nm for Ca 2 SnO 4 , at 410 nm for Sr 2 SnO 4 , and at 425 nm for Ba 2 SnO 4 under UV excitation

  5. Growth of microbial mixed cultures under anaerobic, alkaline conditions

    International Nuclear Information System (INIS)

    Wenk, M.

    1993-09-01

    Cement and concrete are the most important engineered barrier materials in a repository for low- and intermediate-level waste and thus represent the most significant component of the total disposal inventory. Based on the chemical composition of the concrete used in the repository and the groundwater fluxes in the modelled host rock, it is to be expected that the pH in the near vicinity of the repository could exceed a value of 10.5 for more than a million years. The groundwater in the repository environment also has a limited carbon concentration. Since microorganisms will be present in a repository and can even find suitable living conditions within the waste itself, investigations were carried out in order to establish the extent to which microbial activity is possible under the extreme conditions of the repository near-field. For the investigations, alkalophilic cultures were enriched from samples from alkaline habitats and from Valanginian Marl. Anaerobic bacteria with fermentative, sulfate-reducing and methanogenic metabolism were selected. The growth and activity of the mixed cultures were studied under alkaline conditions and the dependence on pH and carbon concentration determined. All the mixed cultures investigated are alkalophilic. The optimum growth range for the cultures is between pH 9.0 and pH 10.0. The activity limit for the fermentative mixed culture is at pH 12, for the sulfate-reducers at pH 11 and for the methanogens at pH 10.5. Given the limited supply of carbon, the mixed cultures can only grow under slightly alkaline conditions. Only the fermentative cultures are capable of surviving with limited carbon supply at pH 13. (author) 24 figs., 18 tabs., 101 refs

  6. Purification and characterization of alkaline proteases from aspergillus terreus

    International Nuclear Information System (INIS)

    Hussain, A.; Mannan, A.; Zubair, H.; Mirza, B.

    2010-01-01

    Proteases belong to an important class of enzymes known as hydrolases and catalyze hydrolysis of proteins. They act primarily to degrade proteins that are used for energy production and as biosynthetic precursors. In the following study, protease produced from Aspergillus terreus was found to be thermo stable and included in the category of alkaline serine and metallo protease. During partial purification, presence of enzyme in 60% (NH/sub 4/)/sub 2/SO/sub 4/ indicated small molecular weight polypeptide; later purification with Sephadex G-75 fractionation yielded a single proteolytic active molecule. At final purification step, the increase in specific activity of the enzyme was 7.5 fold with 23% yield. SDS-PAGE analysis revealed that alkaline protease of Aspergillus terreus is a monomer with approximate molecular weight of 35 kDa. Optimum pH for protease activity was found in the range of 7.5-11.0 (maximum at pH 8.5), thus apparently classified as an alkaline protease. The enzyme was thermo stable towards high temperature (60 deg. C), however it denatured irreversibly at 70 deg. C showing 80% loss of activity. The maximum proteolytic activity was found at 40 deg. C. The enzyme was effectively inhibited by PMSF, EDTA and urea whereas iodoacetamide and thiourea did not result in any loss in activity while cysteine was found to be activator molecule. The study with metal ions Mg/sup +2/, Mn/sup +2/ and Fe/sup +3/ (1 mM each) showed minute stimulatory effects on enzyme activity. Co/sup +2/ and Ca/sup +2/ (1 mM) had neither excitatory nor inhibitory effect while Hg/sup +2/ and Cu/sup +2/ (1 mM) slightly reduced the enzyme activity. (author)

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

    Directory of Open Access Journals (Sweden)

    Chen Ye

    2013-01-01

    Full Text Available Abstract 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

  8. Selection of culture medium and conditions for the production of ...

    African Journals Online (AJOL)

    defined medium–A, defined medium-B, synthetic medium, rich medium and industrial medium) showed that the synthetic medium yielded maximum yeast biomass (12.8 g/LDCW) followed by rich medium (11.7 g/L DCW) and defined medium B ...

  9. Development of a pressurized bipolar alkaline water electrolyzer

    Energy Technology Data Exchange (ETDEWEB)

    Neves Junior, Newton Pimenta; Pinto, Edgar A. de Godoi Rodrigues; Silva, Ennio Peres da; Rapelli, Rubia; Pinto, Cristiano da Silva [Universidade Estadual de Campinas (DFA/ IFGW/UNICAMP), SP (Brazil). Inst. de Fisica Gleb Wataghin. Dept. de Fisica Aplicada], Email: nevesjr@unicamp.br; Marin Neto, Antonio Jose; Lopes, Daniel Gabriel; Camargo, Joao Carlos; Ferreira, Paulo F.P. [Hydrogen Technology (HyTron), Campinas, SP (Brazil); Furlan, Andre Luis [Universidade Estadual de Campinas (DE/FEC/UNICAMP), SP (Brazil). Fac. de Engenharia Mecanica

    2010-07-01

    This paper reports the actual development status of a bipolar alkaline water electrolyzer with maximum production capacity of 1 m3/h of hydrogen and controlled by a PLC (Programmable Logic Controller), which also interfaces the electrolytic system with operators and other equipment, such as gas storage tanks, fuel cells and photovoltaic panels. The project also includes the construction of an electrolysis test bench to record electrical parameters (cathode, anode, separator and electrolyte potentials), the amount of produced gases and gas quality determined by gas chromatography. (author)

  10. Hyper production of alkaline protease by mutagenized bacillus subtilis

    International Nuclear Information System (INIS)

    Qureshi, A.M.; Tanseem, F.

    2010-01-01

    The purpose of this work was to augment the alkaline protease production from Bacillus subtilis by using chemical mutagen (MMS) and UV mutagenesis. A number of mutants were isolated which produce high levels of extra cellular proteases. Analysis of culture supernatants of these mutants had shown that the total amounts of proteolysis activity were increased from 1 to 2 fold over the wild strain. Clones showing promote response were further characterized by analyzing different parameters; like of Temperature, pH substrate concentration and incubation period, to study the activity of protease enzyme. (author)

  11. Combined wet oxidation and alkaline hydrolysis of polyvinylchloride

    DEFF Research Database (Denmark)

    Sørensen, E.; Bjerre, A.B.

    1992-01-01

    In view of the widespread aversion to burning polyvinylchloride (PVC) together with municipal waste, we have attempted an alternative approach to its decomposition. This paper describes a combined wet oxidation/alkaline hydrolysis yielding water soluble, biodegradable products. Experiments were...... carried out at temperatures from 180-260 degree C and reaction times of 8-24 min. The chloride liberated provides information on the rate constants. Considering the measured Cl- and Chemical Oxygen Demand (COD) values, we find hydrolysis and oxidation processes to be interdependent. The main products...

  12. Phosphotyrosine as a substrate of acid and alkaline phosphatases.

    Science.gov (United States)

    Apostoł, I; Kuciel, R; Wasylewska, E; Ostrowski, W S

    1985-01-01

    A new spectrophotometric method for following dephosphorylation of phosphotyrosine has been described. The absorption spectra of phosphotyrosine and tyrosine were plotted over the pH range from 3 to 9. The change in absorbance accompanying the conversion of phosphotyrosine to tyrosine was the greatest at 286 nm. The difference absorption coefficients were calculated for several pH values. Dephosphorylation of phosphotyrosine by acid phosphatases from human prostate gland, from wheat germ and potatoes obeys the Michaelis-Menten equation, whereas alkaline phosphatases calf intestine and E. coli are inhibited by excess of substrate.

  13. A double antibody radioimmunoassay specific for placental alkaline phosphatase

    International Nuclear Information System (INIS)

    Dass, S.; Bagshawe, K.D.

    1984-01-01

    Placental alkaline phosphatase (PLAP) is normally found in enzymically measurable amounts in second and third trimester pregnancy serum. Its occurrence in sera and tumours from patients with malignant disease has led to the development of methods to specifically identify and quantitate the enzyme. Recently immunological techniques have been used, employing antibodies raised to purified PLAP; these include solid phase radioimmunoassays and enzyme-immunoassay. The development of a sensitive, specific, automated double-antibody radioimmunoassay for the measurement of PLAP in serum is reported. (Auth.)

  14. Mechanistic studies of the alkaline degradation of cellulose in cement

    International Nuclear Information System (INIS)

    Greenfield, B.F.; Robertson, G.P.; Spindler, M.W.; Harrison, W.N.; Somers, P.J.

    1993-07-01

    The alkaline degradation of cellulose-based materials under conditions simulating those of a deep underground radioactive waste repository has been investigated. A number of key degradation products, of which 2-C-(hydroxymethyl)-3-deoxy-D-pentonic acid (isosaccharinic acid) is the most important, have been synthesised, and the solubilities of their plutonium complexes have been determined. Analysis of leachates of anaerobically degraded cellulose has shown concentrations of organic acids which are broadly consistent with the enhanced plutonium solubilities found in these leachates. Reaction mechanisms have been identified that can lead to isosaccharinic acid production by non-oxidative transformations, which may be catalysed by some divalent cations. (Author)

  15. Growth of brown trout in acid and alkaline waters

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, R N

    1961-01-01

    Studies have been performed to determine the factors affecting the growth and maturity of brown trout in lochs in the Highlands of Scotland. Evidence has been found which supports the view that the growth rate depends more on the relation between the trout population and the food supply than on any direct influence of the chemical composition of the water. Details are given of the growth rate of trout in nine lochs with a wide range of alkalinities where spawning facilities are either very good or poor or non-existent.

  16. Expression and Characterization of Coprothermobacter proteolyticus Alkaline Serine Protease

    Directory of Open Access Journals (Sweden)

    Tanveer Majeed

    2013-01-01

    Full Text Available A putative protease gene (aprE from the thermophilic bacterium Coprothermobacter proteolyticus was cloned and expressed in Bacillus subtilis. The enzyme was determined to be a serine protease based on inhibition by PMSF. Biochemical characterization demonstrated that the enzyme had optimal activity under alkaline conditions (pH 8–10. In addition, the enzyme had an elevated optimum temperature (60°C. The protease was also stable in the presence of many surfactants and oxidant. Thus, the C. proteolyticus protease has potential applications in industries such as the detergent market.

  17. Tooth enamel sample preparation using alkaline treatment in ESR dosimetry

    International Nuclear Information System (INIS)

    Yongzeng, Zhou; Jiadong, Wang; Xiaomei, Jia; Ke, Wu; Jianbo, Cong

    2002-01-01

    Tooth enamel sample preparation using alkaline treatment was studied and compared with traditional mechanical method in this paper. 20 adult teeth were used. Samples were placed into NaOH solution. This method requires 4-5 weeks and the enamel was separated from dentin. Experimental results show that 8M NaOH was appropriate for separating enamel from dentin and that there is no difference in background signal relative intensity between samples prepared by mechanical and by chemical methods. There is also no difference in radiosensitivity between samples prepared by two methods mentioned above. Dose response curve for tooth enamel samples isolated by 8M NaOH solution was obtained

  18. Chromatographic separation of alkaline phosphatase from dental enamel

    DEFF Research Database (Denmark)

    Moe, D; Kirkeby, S; Salling, E

    1989-01-01

    Alkaline phosphatase (AP) was prepared from partly mineralized bovine enamel by extraction in phosphate buffer, centrifugation and various chromatographic techniques. Chromatofocusing showed that the enamel enzyme possessed five isoelectric points at the acid pH level ranging from pH 5.7 to pH 4.......4. Three enzyme peaks were eluted using low pressure chromatography with a Bio-gel column. With a HPLC gel filtration column the separation of the enamel extract resulted in only one peak with AP activity. The fractions of this peak were used to produce an antibody against bovine AP....

  19. FURNACE INJECTION OF ALKALINE SORBENTS FOR SULFURIC ACID CONTROL; SEMIANNUAL

    International Nuclear Information System (INIS)

    Gary M. Blythe

    2002-01-01

    This document summarizes progress on Cooperative Agreement DE-FC26-99FT40718, Furnace Injection of Alkaline Sorbents for Sulfuric Acid Control, during the time period October 1, 2001 through March 31, 2002. The objective of this project is to demonstrate the use of alkaline reagents injected into the furnace of coal-fired boilers as a means of controlling sulfuric acid emissions. The coincident removal of hydrochloric acid and hydrofluoric acid is also being determined, as is the removal of arsenic, a known poison for NO(sub X) selective catalytic reduction (SCR) catalysts. EPRI, the Tennessee Valley Authority (TVA), FirstEnergy Corporation, American Electric Power (AEP) and the Dravo Lime Company are project co-funders. URS Corporation is the prime contractor. This is the fifth reporting period for the subject Cooperative Agreement. During the previous (fourth) period, two long-term sorbent injection tests were conducted, one on Unit 3 at FirstEnergy's Bruce Mansfield Plant (BMP) and one on Unit 1 at AEP's Gavin Plant. Those tests determined the effectiveness of injecting alkaline slurries into the upper furnace of the boiler as a means of controlling sulfuric acid emissions from these units. The alkaline slurries tested included commercially available magnesium hydroxide slurry (Gavin Plant) and a byproduct magnesium hydroxide slurry (at both Gavin and BMP). The tests showed that injecting either the commercial or the byproduct magnesium hydroxide slurry could achieve up to 70-75% overall sulfuric acid removal. At BMP, the overall removal was limited by the need to maintain acceptable electrostatic precipitator (ESP) particulate control performance. At Gavin Plant, the overall sulfuric acid removal was limited because the furnace injected sorbent was less effective at removing SO(sub 3) formed across the SCR system installed on the unit for NO(sub X) control than at removing SO(sub 3) formed in the furnace. The SO(sub 3) removal results were presented in the

  20. Economic comparisons of acid and alkaline waste systems at SRP

    International Nuclear Information System (INIS)

    Crandall, J.L.; Porter, J.A.

    1974-01-01

    Order-of-magnitude costs for a variety of options for disposal of SRP radioactive processing wastes in retrievable surface storage are given in FY 1975 dollars. The assumption is made that three-reactor operation continues at SRP through the year 2000. Two things are apparent. First, the waste disposal costs are very high, in the range of one to three billion dollars even before escalation to the expected disposal period in FY 1985-2000. Second, the alkaline waste cases are always less expensive then the corresponding acid waste cases even when so-called ideal waste streams are postulated for the acid cases. (U.S.)

  1. Stress-life interrelationships associated with alkaline fuel cells

    Science.gov (United States)

    Thaller, Lawrence H.; Martin, Ronald E.; Stedman, James K.

    1987-01-01

    A review is presented concerning the interrelationships between applied stress and the expected service life of alkaline fuel cells. Only the physical, chemical, and electrochemical phenomena that take place within the fuel cell stack portion of an overall fuel cell system will be discussed. A brief review will be given covering the significant improvements in performance and life over the past two decades as well as summarizing the more recent advances in understanding which can be used to predict the performance and life characteristics of fuel cell systems that have yet to be built.

  2. The interstellar medium in galaxies

    CERN Document Server

    1997-01-01

    It has been more than five decades ago that Henk van de Hulst predicted the observability of the 21-cm line of neutral hydrogen (HI ). Since then use of the 21-cm line has greatly improved our knowledge in many fields and has been used for galactic structure studies, studies of the interstellar medium (ISM) in the Milky Way and other galaxies, studies of the mass distribution of the Milky Way and other galaxies, studies of spiral struc­ ture, studies of high velocity gas in the Milky Way and other galaxies, for measuring distances using the Tully-Fisher relation etc. Regarding studies of the ISM, there have been a number of instrumen­ tal developments over the past decade: large CCD's became available on optical telescopes, radio synthesis offered sensitive imaging capabilities, not only in the classical 21-cm HI line but also in the mm-transitions of CO and other molecules, and X-ray imaging capabilities became available to measure the hot component of the ISM. These developments meant that Milky Way was n...

  3. Studies in medium energy physics

    International Nuclear Information System (INIS)

    Green, A.; Hoffmann, G.W.; McDonough, J.; Purcell, M.J.; Ray, R.L.; Read, D.E.; Worn, S.D.

    1991-12-01

    This document constitutes the (1991--1992) technical progress report and continuation proposal for the ongoing medium energy nuclear physics research program supported by the US Department of Energy through special Research Grant DE-FG05-88ER40444. The experiments discussed are conducted at the Los Alamos National Laboratory's (LANL) Clinton P. Anderson Meson Physics Facility (LAMPF) and the Alternating Gradient Synchrotron (AGS) facility of the Brookhaven National Laboratory (BNL). The overall motivation for the work discussed in this document is driven by three main objectives: (1) provide hadron-nucleon and hadron-nucleus scattering data which serve to facilitate the study of effective two-body interactions, test (and possibly determine) nuclear structure, and help study reaction mechanisms and dynamics; (2) provide unique, first-of-a-kind ''exploratory'' hadron-nucleus scattering data in the hope that such data will lead to discovery of new phenomena and new physics; and (3) perform precision tests of fundamental interactions, such as rare decay searches, whose observation would imply fundamental new physics

  4. Optical illusions induced by rotating medium

    Science.gov (United States)

    Zang, XiaoFei; Huang, PengCheng; Zhu, YiMing

    2018-03-01

    Different from the traditional single-function electromagnetic wave rotators (rotate the electromagnetic wavefronts), we propose that rotating medium can be extended to optical illusions such as breaking the diffraction limit and overlapping illusion. Furthermore, the homogeneous but anisotropic rotating medium is simplified by homogeneous and isotropic positive-index materials according to the effective medium theory, which is helpful for future device fabrication. Finite element simulations for the two-dimensional case are performed to demonstrate these properties.

  5. Geology and petrology of alkaline Massif from Ilha de Vitoria, Sao Paulo State

    International Nuclear Information System (INIS)

    Motoki, A.

    1986-01-01

    Geological and petrological studies of the Vitoria Island Alkaline Complex, State of Sao Paulo, have been carried out by means of photo interpretation; field work, thin section studies, whole-rock chemical analysis, x-ray diffractometry, EPMA mineral analysis, and K-Ar and Rb-Sr dating. Radiometric dating indicates a late Cretaceous age for the Vitoria Island Alkaline Complex, which is concordant with the ages of other neighbouring alkaline bodies. (author)

  6. Mass spectra of alkaline earth salts with a FAB source. Complexation with crown ethers

    International Nuclear Information System (INIS)

    Ulrich, J.

    1987-01-01

    With a liquid desorption FAB source it is possible to obtain alkaline earth metal ions complexed by a crown ether. Conditions for formation of these complexes ions are examined for selection of the complexing agent in function of cation size. Behaviour of alkaline and alkaline earth compounds are compared allowing the differentiation of ion extraction phenomena by liquid desorption ion source and solvent extraction [fr

  7. Bacterial sulphate reduction and the development of alkalinity. II. Laboratory experiments with soils

    Energy Technology Data Exchange (ETDEWEB)

    Abd-El-Malek, Y; Rizk, S G

    1963-01-01

    In waterlogged soils sulphate reduction was characterized by increases in counts of sulphate reducers, and increase in titratable alkalinity, insoluble carbonate, and soluble sulphides, and a decrease in soluble Ca/sup 2 +/ + Mg/sup 2 +/. Presence of organic matter greatly enhanced sulphate reduction. A linear relationship between the amount of sulphate reduced and increases in titratable alkalinity and insoluble carbonate were apparent. The potential effects of sulphate reduction on soil fertility through the development of alkalinity are discussed.

  8. Alkaline Extraction of DNA from Pathogenic Fungi for PCR-RFLP Analysis

    OpenAIRE

    Matsumoto, Masaru; Mishima, Shinobu; Matsuyama, Nobuaki; 松元, 賢; 松山, 宣明

    1997-01-01

    For the preparation of DNA samples from fungal mycelia alkaline extraction method was applied and assessed its usefulness for PCR-RFLP analysis. Using alkaline treatment protocols, 18S ribosomal DNAs (rDNA) derived from fungal genomic DNA of Pyricularia oryzae, P. zingiberi, Rhizoctonia solani and R. oryzae were PCR-amplified and digested with Hha I, Msp I and Hae ill. RFLP analysis with HhaI showed the divergent polymorphism between genus Pyricularia and Rhizoctonia. The alkaline DNA extract...

  9. Trichoderma harzianum transformant has high extracellular alkaline proteinase expression during specific mycoparasitic interactions

    Directory of Open Access Journals (Sweden)

    Goldman Maria Helena S.

    1998-01-01

    Full Text Available The mycoparasite Trichoderma harzianum produces an alkaline proteinase that may be specifically involved in mycoparasitism. We have constructed transformant strains of this fungus that overexpress this alkaline proteinase. Some of the transformants were assessed for alkaline proteinase activity, and those with higher activity than the wild type were selected for further studies. One of these transformant strains produced an elevated and constitutive pbr1 mRNA level during mycoparasitic interactions with Rhizoctonia solani.

  10. Stream Insect Production as a Function of Alkalinity and Detritus Processing

    OpenAIRE

    Osborn, Thomas G.

    1981-01-01

    The study was conducted to determine if aquatic insect production was significantly different between high and low alkalinity mountain streams and if any differences were associated with food availability factors. The major objectives included determining: (1) if annual production differences occur between high and low alkalinity streams; (2) if processing rates of terrestrial detritus differs between high and low alkalinity streams; (3) if detrital processing rates are related to stream inse...

  11. Elevated alkalinity and sulfate adversely affect the aquatic macrophyte Lobelia dortmanna

    OpenAIRE

    Pulido, Cristina; Keijsers, Danny J. H.; Lucassen, E. C. H. E. T.; Pedersen, Ole; Roelofs, J. G. M.

    2012-01-01

    The increase in alkalinity and SO4 2- in softwater lakes can negatively affect pristine isoetid population because the increase in alkalinity and SO4 2- can stimulate sediment mineralization and consequently cause anoxia. The consequences of increased sediment mineralization depend on the ability of isoetids such as Lobelia dortmanna to oxidize the rhizosphere via radial O2 loss. To study how alkalinity and SO4 2- affect the isoetid L. dortmanna, and if neg...

  12. Endurance Test and Evaluation of Alkaline Water Electrolysis Cells

    Science.gov (United States)

    Kovach, Andrew J.; Schubert, Franz H.; Chang, B. J.; Larkins, Jim T.

    1985-01-01

    The overall objective of this program is to assess the state of alkaline water electrolysis cell technology and its potential as part of a Regenerative Fuel Cell System (RFCS) of a multikilowatt orbiting powerplant. The program evaluates the endurance capabilities of alkaline electrolyte water electrolysis cells under various operating conditions, including constant condition testing, cyclic testing and high pressure testing. The RFCS demanded the scale-up of existing cell hardware from 0.1 sq ft active electrode area to 1.0 sq ft active electrode area. A single water electrolysis cell and two six-cell modules of 1.0 sq ft active electrode area were designed and fabricated. The two six-cell 1.0 sq ft modules incorporate 1.0 sq ft utilized cores, which allow for minimization of module assembly complexity and increased tolerance to pressure differential. A water electrolysis subsystem was designed and fabricated to allow testing of the six-cell modules. After completing checkout, shakedown, design verification and parametric testing, a module was incorporated into the Regenerative Fuel Cell System Breadboard (RFCSB) for testing at Life Systems, Inc., and at NASA JSC.

  13. Neutralization potential as an assay of alkalinity of environmental solids

    International Nuclear Information System (INIS)

    Grube, W.E.Jr.; Ammons, J.T.

    1993-01-01

    The method to determine neutralizing equivalence of agricultural limestone has been applied to quantify the amount of bases present in a broad diversity of mineral materials, solid reagents, and products involved in environmental processes. The capacity to neutralize native or imposed acidity must be known in many processes in order to preserve near-neutral material. The standard method for assaying agricultural limestones was adapted to quantify native alkalinity in calcareous rocks exposed by coal surface mining. Data from these analyses continue to provide the surface mining industry and regulating agencies with a measure of the extent to which acidic mine drainage may be neutralized by the natural components of surrounding rock strata and disturbed materials. This approach to determine base content has also been applied to commercially available industrial byproducts added to soils or wastes. Kiln dust, fly ash, sludge, and other additives have been evaluated routinely to measure their alkalinity contribution and also batch-to-batch uniformity. The application of this technique to monitor amounts of reagents added to neutralize acid waste materials by adding alkalis is discussed. Use of this procedure to evaluate different materials is documented with exemplary data. Results of analyses of a broad variety of rock and soil materials, amended soils, soil additives or amendments, industrial waste byproducts, sludge, and treated wastes are presented. Utility of the procedure for routine quality control in soil treatment, amendment uniformity, and product analysis is discussed

  14. Transpassive electrodissolution of depleted uranium in alkaline electrolytes

    International Nuclear Information System (INIS)

    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 3 ·2H 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

  15. Semi-Automatic Rating Method for Neutrophil Alkaline Phosphatase Activity.

    Science.gov (United States)

    Sugano, Kanae; Hashi, Kotomi; Goto, Misaki; Nishi, Kiyotaka; Maeda, Rie; Kono, Keigo; Yamamoto, Mai; Okada, Kazunori; Kaga, Sanae; Miwa, Keiko; Mikami, Taisei; Masauzi, Nobuo

    2017-01-01

    The neutrophil alkaline phosphatase (NAP) score is a valuable test for the diagnosis of myeloproliferative neoplasms, but it has still manually rated. Therefore, we developed a semi-automatic rating method using Photoshop ® and Image-J, called NAP-PS-IJ. Neutrophil alkaline phosphatase staining was conducted with Tomonaga's method to films of peripheral blood taken from three healthy volunteers. At least 30 neutrophils with NAP scores from 0 to 5+ were observed and taken their images. From which the outer part of neutrophil was removed away with Image-J. These were binarized with two different procedures (P1 and P2) using Photoshop ® . NAP-positive area (NAP-PA) and granule (NAP-PGC) were measured and counted with Image-J. The NAP-PA in images binarized with P1 significantly (P < 0.05) differed between images with NAP scores from 0 to 3+ (group 1) and those from 4+ to 5+ (group 2). The original images in group 1 were binarized with P2. NAP-PGC of them significantly (P < 0.05) differed among all four NAP score groups. The mean NAP-PGC with NAP-PS-IJ indicated a good correlation (r = 0.92, P < 0.001) to results by human examiners. The sensitivity and specificity of NAP-PS-IJ were 60% and 92%, which might be considered as a prototypic method for the full-automatic rating NAP score. © 2016 Wiley Periodicals, Inc.

  16. Principles and Materials Aspects of Direct Alkaline Alcohol Fuel Cells

    Directory of Open Access Journals (Sweden)

    Eileen Hao Yu

    2010-08-01

    Full Text Available Direct alkaline alcohol fuel cells (DAAFCs have attracted increasing interest over the past decade because of their favourable reaction kinetics in alkaline media, higher energy densities achievable and the easy handling of the liquid fuels. In this review, principles and mechanisms of DAAFCs in alcohol oxidation and oxygen reduction are discussed. Despite the high energy densities available during the oxidation of polycarbon alcohols they are difficult to oxidise. Apart from methanol, the complete oxidation of other polycarbon alcohols to CO2 has not been achieved with current catalysts. Different types of catalysts, from conventional precious metal catalyst of Pt and Pt alloys to other lower cost Pd, Au and Ag metal catalysts are compared. Non precious metal catalysts, and lanthanum, strontium oxides and perovskite-type oxides are also discussed. Membranes like the ones used as polymer electrolytes and developed for DAAFCs are reviewed. Unlike conventional proton exchange membrane fuel cells, anion exchange membranes are used in present DAAFCs. Fuel cell performance with DAAFCs using different alcohols, catalysts and membranes, as well as operating parameters are summarised. In order to improve the power output of the DAAFCs, further developments in catalysts, membrane materials and fuel cell systems are essential.

  17. Thermodynamic framework for estimating the efficiencies of alkaline batteries

    Energy Technology Data Exchange (ETDEWEB)

    Pound, B G; Singh, R P; MacDonald, D D

    1986-06-01

    A thermodynamic framework has been developed to evaluate the efficiencies of alkaline battery systems for electrolyte (MOH) concentrations from 1 to 8 mol kg/sup -1/ and over the temperature range -10 to 120/sup 0/C. An analysis of the thermodynamic properties of concentrated LiOH, NaOH, and KOH solutions was carried out to provide data for the activity of water, the activity coefficient of the hydroxide ion, and the pH of the electrolyte. Potential-pH relations were then derived for various equilibrium phenomena for the metals Li, Al, Fe, Ni, and Zn in aqueous solutions and, using the data for the alkali metal hydroxides, equilibrium potentials were computed as a function of composition and temperature. These data were then used to calculate reversible cell voltages for a number of battery systems, assuming a knowledge of the cell reactions. Finally, some of the calculated cell voltages were compared with observed cell voltages to compute voltage efficiencies for various alkaline batteries. The voltage efficiencies of H/sub 2//Ni, Fe/Ni, and Zn/Ni test cells were found to be between 90 and 100%, implying that, at least at open circuit, there is little, if any, contribution from parasitic redox couples to the cell potentials for these systems. The efficiency of an Fe/air test cell was relatively low (72%). This is probably due to the less-than-theoretical voltage of the air electrode.

  18. Hydrothermal alkaline stability of bentonite barrier by concrete interstitial wastes

    International Nuclear Information System (INIS)

    Leguey Jimenez, S.; Cuevas Rodriguez, J.; Ramirez Martin, S.; Vigil de la villa Mencia, R.; Martin Barca, M.

    2002-01-01

    At present, the main source of High Level radioactive Waste (HLW) is the electrical energy production during all the steps of developing. In almost all the countries with nuclear programs, the option for the final management of HLW is the Deep Geological Repository (DGR) based on the concept of multi barrier. According to this concept, the waste is isolated from biosphere by the interposition of confinement barriers. Two of the engineering barriers in the Spanish design of DGR in granitic rock are compacted bentonite and concrete. The bentonite barrier is the backfilling and sealing material for the repository gallery, because of its mechanical and physico-chemical properties. The main qualities of concrete as a component of a multi barrier system are its low permeability, mechanical resistance and chemical properties. With regard to chemical composition of concrete, the alkaline nature of cement pore water lowers the solubility of many radioactive elements. However, structural transformation in smectite, dissolution or precipitation of minerals and, consequently, changes in the bentonite properties could occurs in the alkaline conditions generated by the cement degradation. The main objective of the present work is to evaluate the effect of concrete in the stability of Spanish reference bentonite (La Serrata of Nijar, Almeria, Spain) in conditions similar to those estimated in a DGR in granitic rock. Because of the main role of bentonite barrier in the global performance of the repository, the present study is essential to guarantee its security. (Author)

  19. Acidic Attack Resistance of Cement Mortar Treated with Alkaline

    Directory of Open Access Journals (Sweden)

    Nadia Nazhat Sabeeh

    2017-12-01

    Full Text Available The negative effect of acidic attack on the properties of concrete and cement mortar is a topic of increasing significance in the recent years. Many attempts has occurred to mitigate this negative impact by improving the properties of concrete and increase resistance to acids by using additives. The present study includes treatment of sand by alkaline material and examine the effect of treatment on cement mortar resistance towards hydrochloric and sulfuric acid. Results show that sand treatment by alkaline material significantly enhance mortar ability to resist acids. In terms of loss weight, the maximum weight rate gain was 25.54% for specimens immersed in Hydrochloric acid with water cement ratio 40%. For specimens immersed in HCl, the average gain in compressive strength is (20.15-19.433% for w/c (40-45% respectively. The average gain in modulus of rupture toward the influence of H2SO4 is (18.37–17.99% for w/c (40-45%, respectively.

  20. [Construction and high-density fermentation of alkaline pectate lyase high-yield yeast].

    Science.gov (United States)

    Wang, Xiaowen; Xiang, La; Xu, Ting; Lu, Zhenghui; Zhang, Guimin

    2017-12-25

    Pectate lyase is widely applied in ramie degumming and fabric bioscouring in the textile industry. Compared to conventional processes that involve high alkaline and high temperature treatment, enzyme based treatments have significant advantages in fibers protectiveness, improved efficiency of refining, reduced energy consumption and pollution. Hence, it would be highly desirable to construct high-yield alkaline pectate lyase engineered strains and reduce the pectate lyase production cost. In the previous study, pectate lyase gene pel from Bacillus subtilis168 was expressed in Pichia pastoris GS115 after codon usage optimization based on the vector pHBM905A. To improve the expression level, the vector pHBM905BDM with optimized promoter and signal peptide was used to express the optimized gene pels in GS115. The transformant had increased activity from 68 U/mL to 100 U/mL with the improvement in the transcription level by 27% measured by qPCR. The transformants were further screened on pectin plates, where higher halo forming strains were picked for shake-flask fermentation and strain GS115-pHBM905BDM-pels4 showed the highest activity of 536 U/mL. Then plasmid pPIC9K-pels was constructed and electroporated into the GS115-pHBM905BDM-pels4 cells. Subsequently, high-copy transformant was screened by using the medium containing antibiotics G418, strain GS115-pHBM905BDMpPIC9K- pels1 was identified with increased activity of 770 U/mL and the copy number of pels was 7 confirmed by qPCR. Finally, the activity of pectate lyase produced by GS115-pHBM905BDM-pPIC9K-pels1reached to 2 271 U/mL in a 5-L fermentor. The activity of pectate lyase in our study reached the highest level of expression in P. pastoris, showing good application potential in the textile industry.

  1. Calcium Concentration in Culture Medium as a Nondestructive and Rapid Marker of Osteogenesis.

    Science.gov (United States)

    Tanikake, Yohei; Akahane, Manabu; Furukawa, Akira; Tohma, Yasuaki; Inagaki, Yusuke; Kira, Tsutomu; Tanaka, Yasuhito

    2017-06-09

    Artificial bones made of β-tricalcium phosphate (β-TCP) combined with bone marrow-derived mesenchymal stromal cells (BM-MSCs) are used for effective reconstruction of bone defects caused by genetic defects, traumatic injury, or surgical resection of bone tumors. However, the selection of constructs with high osteogenic potential before implantation is challenging. The purpose of this study was to determine whether the calcium concentration in BM-MSC culture medium can be used as a nondestructive and simple osteogenic marker for selecting tissue-engineered grafts constructed using β-TCP and BM-MSCs. We prepared three cell passages of BM-MSCs derived from three 7-week-old, male Fischer 344 rats; the cells were cultured in osteoinductive medium in the presence of β-TCP for 15 days. The medium was replaced with fresh medium on day 1 in culture and subsequently changed every 48 h; it was collected for measurement of osteocalcin secretion and calcium concentration by enzyme-linked immunosorbent assay and X-ray fluorescence spectrometry, respectively. After cultivation, the constructs were implanted subcutaneously into the backs of recipient rats. Four weeks after implantation, the alkaline phosphatase (ALP) activity and osteocalcin content of the constructs were measured. A strong inverse correlation was observed between the calcium concentration in the medium and the ALP activity and osteocalcin content of the constructs, with Pearson's correlation coefficients of 0.92 and 0.90, respectively. These results indicate that tissue-engineered bone with high osteogenic ability can be selected before implantation based on low calcium content of the culture medium, resulting in successful bone formation after implantation. This nondestructive, simple method shows great promise for assessing the osteogenic ability of tissue-engineered bone.

  2. Study by acoustic emission and electrochemical methods of the corrosion and the protection of the copper-zinc alloy (60/40) in neutral and alkaline media

    International Nuclear Information System (INIS)

    Assouli, B.

    2002-12-01

    The aim of this work is to study and characterize, by electrochemical methods and acoustic emission, the corrosion and the protection of the copper-zinc alloy (60/40) having a metallographic structure αβ'. The electrochemical measurements, in neutral, chlorinated or alkaline medium have allowed, to study the corrosion resistance of the copper-zinc and to show that the corrosion of this alloy, in the used media, is determined by a diffusional mechanism. The observations to the optical and scanning electron microscopes and the EDX analyzes have confirmed that this corrosion phenomenon is mainly due to the selective dissolution of the β' phase. The acoustic emission has shown, during this corrosion, the presence of two emissive sources whose initiation has been attributed to the relaxation of the micro- and macro- residual stresses of the α phase. These stresses have been characterized by X-ray diffraction and the salvoes emitted during the relaxation of these stresses have been discriminated by the characteristic frequencies and by the barycenter of their spectral density. The protection of this alloy has been carried out by the 2-mercapto-benzimidazole (MBI). This last compound has been tested both as inhibitor added directly in the corrosive medium and/or as polymer film previously deposited by an electrochemical way (p-MBI). The MBI is very efficient for an inhibition in a chlorinated alkaline medium. It is an interphase inhibitor. The p-MBI is efficient too in a neutral chlorinated medium and is moreover non pollutant for the environment. (O.M.)

  3. Recordable storage medium with protected data area

    NARCIS (Netherlands)

    2005-01-01

    The invention relates to a method of storing data on a rewritable data storage medium, to a corresponding storage medium, to a corresponding recording apparatus and to a corresponding playback apparatus. Copy-protective measures require that on rewritable storage media some data must be stored which

  4. Electromagnetic Sources in a Moving Conducting Medium

    DEFF Research Database (Denmark)

    Johannsen, Günther

    1971-01-01

    The problem of an arbitrary source distribution in a uniformly moving, homogeneous, isotropic, nondispersive, conducting medium is solved. The technique used is to solve the problem in the rest system of the medium and then write the result in an appropriate four-dimensional, covariant form which...

  5. Kultivasi Scenedesmus SP. Pada Medium Air Limbah

    OpenAIRE

    Kawaroe, Mujizat

    2011-01-01

    Proses fotosintesis pada mikroalga membutuhkan CO2 dan cahaya matahari serta nutrien untuk pertumbuhannya. Kultivasi Scenedesmus sp. pada medium air limbah bertujuan guna mencukupi kebutuhan mikroalga akan nutrien dan mengurangi masukan dari bahan kimia yang terkandung dalam air limbah tersebut ke lingkungan. Kultivasi Scenedesmus sp. dilakukan selama tujuh hari pada medium air limbah industri tanpa penambahan nutri...

  6. Effective medium theory for anisotropic metamaterials

    KAUST Repository

    Zhang, Xiujuan; Wu, Ying

    2015-01-01

    -dimensional metamaterial composed of a rectangular array of elliptic cylinders and derive an effective medium theory for such a metamaterial. We find that it is possible to obtain a closed-form analytical solution for the anisotropic effective medium parameters, provided

  7. Selective medium for aerobic incubation of Campylobacter

    Science.gov (United States)

    Studies were conducted on the formulation of a selective medium that could be used to isolate Campylobacter from mixed bacterial cultures using aerobic incubation. A non-selective, basal broth medium was prepared and supplemented with Bolton, Cefex, or Skirrow antibiotic mixtures. The ability of pur...

  8. Effective medium theory for anisotropic metamaterials

    KAUST Repository

    Zhang, Xiujuan

    2015-01-20

    Materials with anisotropic material parameters can be utilized to fabricate many fascinating devices, such as hyperlenses, metasolids, and one-way waveguides. In this study, we analyze the effects of geometric anisotropy on a two-dimensional metamaterial composed of a rectangular array of elliptic cylinders and derive an effective medium theory for such a metamaterial. We find that it is possible to obtain a closed-form analytical solution for the anisotropic effective medium parameters, provided the aspect ratio of the lattice and the eccentricity of the elliptic cylinder satisfy certain conditions. The derived effective medium theory not only recovers the well-known Maxwell-Garnett results in the quasi-static regime, but is also valid beyond the long-wavelength limit, where the wavelength in the host medium is comparable to the size of the lattice so that previous anisotropic effective medium theories fail. Such an advance greatly broadens the applicable realm of the effective medium theory and introduces many possibilities in the design of structures with desired anisotropic material characteristics. A real sample of a recently theoretically proposed anisotropic medium, with a near-zero index to control the flux, is achieved using the derived effective medium theory, and control of the electromagnetic waves in the sample is clearly demonstrated.

  9. Cyclic, Early Diagenetic Dolomite Formation in Alkaline Lake Van

    Science.gov (United States)

    McCormack, J.; Bontognali, T. R. R.; Immenhauser, A.; Kwiecien, O.

    2017-12-01

    Modern dolomite-forming environments are commonly constrained to evaporitic marine or marginal marine settings such as lagoons and sabkhas. Beside microbial mediation, high temperatures and Mg2+ concentrations in solution are factors considered important in aiding dolomite formation. Accordingly, previous studies associate the presence of dolomite within deep sediments of alkaline Lake Van (Turkey) with periods of enhanced evaporation, low lake levels and high Mg/Ca ratio. We systematically studied dolomite within the sedimentary record of Lake Van by means of XRD, SEM and stable isotope (δ18O and δ13C) mass spectrometry. First, we considered the origin of the dolomite; next, we focused on the wider implication of its presence. SEM imaging documents large dolomite crystals interwoven with clay minerals and individual crystals with different crystallographic orientations grown together, indicating space-limited growth within the sediment. According to recent climatic reconstructions for the same sequence (ICDP PALEOVAN project), the water depth of the coring site - today at 350 m - unlikely fell below 200 m. Consequently, dolomite formed below a thick water column at constantly low temperatures (supported by heavy δ18O signature). Within this environment, variations in Mg/Ca ratio, pH and alkalinity, which are constantly high, have no effect on the episodic nature of dolomite precipitation. These observations call for a re-evaluation of the palaeoenvironments often invoked to interpret intervals rich in dolomite within ancient sedimentary sequences (e.g., periods of enhanced aridity and evaporation). Further, and in contrast to previous interpretations, our dolomite concentration data backed up by ICDP PALEOVAN reconstructions suggest that intervals rich in dolomite coincide with periods of high lake level and increased humidity. High dolomite concentrations (20 - 85 % relative carbonate content) occur cyclically within the last glacial period and coincide with

  10. Safety of an alkalinizing buffer designed for inhaled medications in humans.

    Science.gov (United States)

    Davis, Michael D; Walsh, Brian K; Dwyer, Scott T; Combs, Casey; Vehse, Nico; Paget-Brown, Alix; Pajewski, Thomas; Hunt, John F

    2013-07-01

    Airway acidification plays a role in disorders of the pulmonary tract. We hypothesized that the inhalation of alkalinized glycine buffer would measurably alkalinize the airways without compromising lung function or causing adverse events. We evaluated the safety of an inhaled alkaline glycine buffer in both healthy subjects and in subjects with stable obstructive airway disease. This work includes 2 open-label safety studies. The healthy controls were part of a phase 1 safety study of multiple inhalations of low-dose alkaline glycine buffer; nebulized saline was used as a comparator in 8 of the healthy controls. Subsequently, a phase 2 study in subjects with stable obstructive airway disease was completed using a single nebulized higher-dose strategy of the alkaline inhalation. We studied 20 non-smoking adults (10 healthy controls and 10 subjects with obstructive airway disease), both at baseline and after inhalation of alkaline buffer. We used spirometry and vital signs as markers of clinical safety. We used changes in fraction of exhaled nitric oxide (NO) and exhaled breath condensate (EBC) pH as surrogate markers of airway pH modification. Alkaline glycine inhalation was tolerated by all subjects in both studies, with no adverse effects on spirometric parameters or vital signs. Airway alkalinization was confirmed by a median increase in EBC pH of 0.235 pH units (IQR 0.56-0.03, P = .03) in subjects after inhalation of the higher-dose alkaline buffer (2.5 mL of 100 mmol/L glycine). Alkalinization of airway lining fluid is accomplished with inhalation of alkaline glycine buffer and causes no adverse effects on pulmonary function or vital signs.

  11. Micropropagation of Alstroemeria in liquid medium using slow release of medium components

    NARCIS (Netherlands)

    Klerk, de G.J.M.; Brugge, ter J.

    2010-01-01

    Alstroemeria rhizomes were micropropagated on semi-solid medium (AM) and in liquid medium (LM). In LM, growth was much enhanced (ca. 70%). Adequate gas exchange was crucial. This was obtained by agitation and in static medium by a sufficient large contact area of the explant and the gaseous

  12. Zinc electrodeposition from alkaline zincate solution by pulsating overpotentials

    Directory of Open Access Journals (Sweden)

    MILOS V. SIMICIC

    2000-09-01

    Full Text Available It is well known that smooth zinc deposits cannot be obtained from alkaline zincate using constant overpotential and current rate. During prolonged metal deposition, spongy and dendritic deposits are formed. It has been shown that the deposits are less agglomerated in the case of square-wave pulsating overpotentials regime than the ones obtained in case of constant overpotential regime. This is explained in a semiquantitative way by two phenomena: selective anodic dissolution during overpotentials “off” period and decreasing diffusion control. These effects is more pronounced at higher pause-to-pulse ratio. Increasing the pause-to-pulse ratio causes a reduction of the ratio between diffusion and activation overpotential, resulting in a more compact deposit. Confirmation of the proposed semiquantitative mathematical model was obtained by zinc electrodeposition onto a copper wire from a 0.1 M zincate solution in 1.0 M KOH at room temperature.

  13. Chemical degradation of fluoroelastomer in an alkaline environment

    DEFF Research Database (Denmark)

    Mitra, S.; Ghanbari-Siahkali, A.; Kingshott, P.

    2004-01-01

    We have investigated the time-dependent chemical degradation of a fluoroelastomer, FKM (Viton((R)) A), in an alkaline environment (10% NaOH, 80 degreesC). Optical microscopy and SEM analysis reveal that degradation starts with surface roughness right from the earliest stage of exposure (e.g., 1...... week) and finally results in cracks on the surface after prolonged exposure. Initially the extent of degradation is mainly confined to the surface regions (a few nanometers) but with longer exposure (e.g., 12 weeks) it extends to below the subsurface region of the fluoroelastomer. The extent...... of this surface degradation is found to be strong enough to affect the bulk mechanical properties. The molecular mechanisms of the surface chemical degradation were determined using surface analysis (XPS and ATR-FTIR) where the initial degradation was found to proceed via dehydrofluorination. This leads to double...

  14. Nickel hydroxide positive electrode for alkaline rechargeable battery

    Science.gov (United States)

    Young, Kwo; Wang, Lixin; Mays, William; Reichman, Benjamin; Chao-Ian, Hu; Wong, Diana; Nei, Jean

    2018-02-20

    Certain nickel hydroxide active cathode materials for use in alkaline rechargeable batteries are capable of transferring >1.3 electrons per Ni atom under reversible electrochemical conditions. The specific capacity of the nickel hydroxide active materials is for example .gtoreq.325 mAh/g. The cathode active materials exhibit an additional discharge plateau near 0.8 V vs. a metal hydride (MH) anode. Ni in an oxidation state of less than 2, such as Ni.sup.1+, is able to participate in electrochemical reactions when using the present cathode active materials. It is possible that up to 2.3 electrons, up to 2.5 electrons or more may be transferred per Ni atom under electrochemical conditions.

  15. Development of Hydrogen Electrodes for Alkaline Water Electrolysis

    DEFF Research Database (Denmark)

    Kjartansdóttir, Cecilía Kristín

    , production of electricity via fuel cells, fuel for internal combustion engines or gas turbines, or as a raw material for the production of synthetic fuels via Sabatier or Fischer - Tropsch process. In some situations it may be suitable to simply inject hydrogen into the existing natural gas based...... will be needed. Producing hydrogen via water electrolysis using surplus, low cost, power from renewables offers the possibility of increased production capacity and load management with no greenhouse emissions. Hydrogen is a valuable energy carrier, which is able to contribute to various forms of energy, such as...... infrastructure. Alkaline water electrolysis (AWE) is the current standard (stat of the art) for industrial large-scale water electrolysis systems. One of the main criteria for industrial AWE is efficient and durable electrodes. The aim of the present PhD study was to develop electrode materials for hydrogen...

  16. Alkaline treatment on piassava (Attalea funifera martius) fiber

    International Nuclear Information System (INIS)

    Santos, E.B.C.; Moreno, C.G.; Barros, J.J.P.; Moura, D.A.; Fim, F.C.; Wellen, R.M.R.; Silva, L.B.

    2016-01-01

    Alkaline treatment on piassava fiber with size inferior to 270 mesh was performed to remove impurities. The treatments took place under magnetic stirring and Sodium Hydroxide (NaOH) solution with 2, 4, 6 and 8% of concentration; processing time ranged between 100 and 400 minutes, with intervals of 25 minutes; the main object was to reach the optimum concentration and time. The concentration 2% was used to remove efficiently the impurities without damaging excessively the fiber. The fibers were characterized by means of X-ray diffraction (XRD) and optical microscopy (OM). Fibers presented XRD diffraction peak around 22 deg, due to the crystalline structure of cellulose. By optical microscopy was observed the treatment efficacy of the 2% NaOH solution in removing surface impurities. (author)

  17. Electro-oxidation of methanol on copper in alkaline solution

    International Nuclear Information System (INIS)

    Heli, H.; Jafarian, M.; Mahjani, M.G.; Gobal, F.

    2004-01-01

    The electro-oxidation of methanol on copper in alkaline solutions has been studied by the methods of cyclic voltammetry, quasi-steady state polarization and chronoamperometry. It has been found that in the course of an anodic potential sweep the electro-oxidation of methanol follows the formation of Cu III and is catalysed by this species through a mediated electron transfer mechanism. The reaction also continues in the early stages of the reversed cycle until it is stopped by the prohibitively negative potentials. The process is diffusion controlled and the current-time responses follow Cottrellian behavior. The rate constants, turnover frequency, anodic transfer coefficient and the apparent activation energy of the electro-oxidation reaction are reported

  18. Formulating a low-alkalinity cement for radioactive waste repositories

    International Nuclear Information System (INIS)

    Coumes, C. Cau Dit; Courtois, S.; Leclercq, S.; Bourbon, X.

    2004-01-01

    A multi-annual research program has been launched in January 2003 by CEA, EDF and ANDRA in order to formulate and characterize low-alkalinity and low-heat cements which would be compatible with an underground waste repository environment. Four types of bindings have been investigated: binary blends of Portland cement and silica fume or metakaolin, as well as ternary blends of Portland cement, fly ash and silica fume or metakaolin. Promising results have been obtained with a mixture comprising 37.5% Portland cement, 32.5% silica fume, and 30% fly ash: pH of water in equilibrium with fully hydrated cement is below 11. Moreover, silica fume compensates for the low reactivity of fly ash, while fly ash allows to reduce water demand, heat release, and dimensional variations of cement pastes and mortars. (authors)

  19. Foam Based Gas Diffusion Electrodes for Reversible Alkaline Electrolysis Cells

    DEFF Research Database (Denmark)

    Allebrod, Frank; Chatzichristodoulou, Christodoulos; Mogensen, Mogens Bjerg

    2014-01-01

    Alkaline electrolysis cells operated at 250 °C and 40 bar have shown to be able to convert electrical energy into hydrogen at very high efficiencies and power densities. Foam based gas diffusion electrodes and an immobilized electrolyte allow for reversible operation as electrolysis cell or fuel...... cell. In the present work we demonstrate the application of hydrophobic, porous, and electro-catalytically active gas diffusion electrodes. PTFE particles and silver nanowires as electro-catalysts were used in the gas diffusion electrodes. Impedance spectroscopy and cyclic voltammetry were performed...... to determine the cell characteristics. The thickness of the electrolyte matrix was only 200 µm, thereby achieving a serial resistance and area specific resistance of 60 mΩ cm2 and 150 mΩ cm2, respectively, at 200 °C and 20 bar. A new production method was developed to increase the cell size from lab scale (1...

  20. Foam Based Gas Diffusion Electrodes for Reversible Alkaline Electrolysis Cells

    DEFF Research Database (Denmark)

    Allebrod, Frank; Chatzichristodoulou, Christodoulos; Mogensen, Mogens Bjerg

    2014-01-01

    Alkaline electrolysis cells operated at 250 °C and 40 bar have shown to be able to convert electrical energy into chemical energy in the form of hydrogen at very high efficiencies and power densities. Foam based gas diffusion electrodes and a liquid immobilized electrolyte allow the operation...... of the newly designed electrolysis cell as a fuel cell, but condensation of steam may lead to blocked pores, thereby inhibiting gas diffusion and decreasing the performance of the cell. In the here presented work we present the application of a hydrophobic, porous, and electro-catalytically active layer...... the electrochemical characteristics of the cell. The thickness of the electrolyte matrix was reduced to 200 µm, thereby achieving a serial resistance and area specific resistance as low as 60 mΩ cm2 and 150 mΩ cm2, respectively, at a temperature of 200 °C and 20 bar pressure. A new production method was developed...

  1. Microhardness of anodic aluminum oxide formed in an alkaline electrolyte

    Science.gov (United States)

    Kanygina, O. N.; Filyak, M. M.

    2017-04-01

    The microhardness of anodic aluminum oxide formed by anodizing of aluminum sheet in electrolyte on the basis of sodium hydroxide has been determined experimentally. The microhardness of the hard film/soft substrate system has been estimated by three approaches: indentation geometry (length of diagonals) in film surfaces, the sum of the hardnesses of the film and the surface with allowance for the indentation surface area and geometry, and with allowance for the indentation depth. It is demonstrated that the approach accounting for the indentation depth makes it possible to eliminate the influence of the substrate. It is established that the microhardness of the films formed in alkaline electrolytes is comparable with that formed in acid electrolytes.

  2. Kinetics studies of oxidation of niacinamide by alkaline potassium permanganate

    Directory of Open Access Journals (Sweden)

    Sandipsingh Gour

    2012-04-01

    Full Text Available The oxidation of niacinamide in alkaline media is carried out using potassium permanganate as a oxiding agent. The reaction was monitored using UV-Visible spectrophotometer at 525 nm. It was found to be zero order with respect to oxidant,, fractional order with respect to hydrogen ion concentration and first order with respect to substrate. The thermodynamic parameters(were determinied . The average (?G# was found to be 87.60 KJ/mol. The values ?S# was found to be -0.2132 KJ/mole and energy of activation was found to be 23.95 KJ/mole. A suitable mechanism is proposed based on the experimental conditions.

  3. Establishing Quantitative Standards for Residual Alkaline Phosphatase in Pasteurized Milk.

    Science.gov (United States)

    Kim, Dong-Hyeon; Chon, Jung-Whan; Lim, Jong-Soo; Kim, Hong-Seok; Kang, Il-Byeong; Jeong, Dana; Song, Kwang-Young; Kim, Hyunsook; Kim, Kwang-Yup; Seo, Kun-Ho

    2016-01-01

    The alkaline phosphatase (ALP) assay is a rapid and convenient method for verifying milk pasteurization. Since colorimetric ALP assays rely on subjective visual assessments, their results are especially unreliable near the detection limits. In this study, we attempted to establish quantitative criteria for residual ALP in milk by using a more objective method based on spectrophotometric measurements. Raw milk was heat-treated for 0, 10, 20, 30, and 40 min and then subjected to ALP assays. The quantitative criteria for residual ALP in the milk was determined as 2 μg phenol/mL of milk, which is just above the ALP value of milk samples heat-treated for 30 min. These newly proposed methodology and criteria could facilitate the microbiological quality control of milk.

  4. Technological development and prospect of alkaline fuel cells

    International Nuclear Information System (INIS)

    Meng Ni; Michael KH Leung; Dennis YC Leung

    2006-01-01

    This paper reviewed the technological development of alkaline fuel cell (AFC). Although the technology was popular in 1970's and 1980's, there has been a decline in AFC research over the past decade, mainly due to the poisoning of CO 2 . Continuous efforts have demonstrated that CO 2 concentration could be reduced to an acceptable level by a number of viable methods such as absorption, adsorption, electrochemical process, electrolyte circulation, use of liquid hydrogen, and use of solid anionic exchange membranes. Literature survey showed that AFC lifetime could achieve up to 5000 hours. In addition, the use of ammonia as a fuel for AFC was identified as a promising technology. Comparison between AFC and proton exchange membrane fuel cell (PEMFC) was presented to evaluate the AFC technology and its economics. The present review and assessment showed the promise of AFC for the coming hydrogen economy and sustainable development. (authors)

  5. Nickel hydroxide positive electrode for alkaline rechargeable battery

    Science.gov (United States)

    Young, Kwo; Wang, Lixin; Mays, William; Reichman, Benjamin; Chao-Ian, Hu; Wong, Diana; Nei, Jean

    2018-04-03

    Certain nickel hydroxide active cathode materials for use in alkaline rechargeable batteries are capable of transferring >1.3 electrons per Ni atom under reversible electrochemical conditions. The specific capacity of the nickel hydroxide active materials is for example .gtoreq.325 mAh/g. The cathode active materials exhibit an additional discharge plateau near 0.8 V vs. a metal hydride (MH) anode. Ni in an oxidation state of less than 2, such as Ni.sup.1+, is able to participate in electrochemical reactions when using the present cathode active materials. It is possible that up to 2.3 electrons, up to 2.5 electrons or more may be transferred per Ni atom under electrochemical conditions.

  6. Reinforcement corrosion in alkaline chloride media with reduced oxygen concentrations

    International Nuclear Information System (INIS)

    Andrade, C.; Fullea, J.; Toro, L.; Martinez, I.; Rebolledo, N.

    2013-01-01

    It is commonly considered that the corrosion of steel in concrete is controlled by the oxygen content of the pore solution and there are service life models that relate the corrosion rate to the amount of oxygen. It is also commonly believed that in water saturated conditions the oxygen content in the pores is negligible and that underwater there is no risk of depassivation and the corrosion rate is very low. However, the available data on corrosion rates in immersed conditions do not indicate such performance; on the contrary corrosion develops when sufficient chloride reaches the reinforcement. In the present paper, results are presented for tests performed in alkaline chloride solutions that were purged with nitrogen to reduce the oxygen content. The results indicate that at very low oxygen concentrations, corrosion may develop in the presence of chlorides. The presence or absence of corrosion is influenced by the amount of chloride, the corrosion potential and the steel surface condition. (authors)

  7. Metal Oxide Decomposition In Hydrothermal Alkaline Sodium Phosphate Solutions

    Energy Technology Data Exchange (ETDEWEB)

    S.E. Ziemniak

    2003-09-24

    Alkaline hydrothermal solutions of sodium orthophosphate (2.15 < Na/P < 2.75) are shown to decompose transition metal oxides into two families of sodium-metal ion-(hydroxy)phosphate compounds. Equilibria for these reactions are quantified by determining phosphate concentration-temperature thresholds for decomposition of five oxides in the series: Ti(IV), Cr(III), Fe(III, II), Ni(II) and Zn(II). By application of a computational chemistry method General Utility Lattice Program (GULP), it is demonstrated that the unique non-whole-number Na/P molar ratio of sodium ferric hydroxyphosphate is a consequence of its open-cage structure in which the H{sup +} and excess Na{sup +} ions are located.

  8. Reaction cross section calculation of some alkaline earth elements

    Science.gov (United States)

    Tel, Eyyup; Kavun, Yusuf; Sarpün, Ismail Hakki

    2017-09-01

    Reaction cross section knowledge is crucial to application nuclear physics such as medical imaging, radiation shielding and material evaluations. Nuclear reaction codes can be used if the experimental data are unavailable or are improbably to be produced because of the experimental trouble. In this study, there action cross sections of some target alkaline earth elements have been calculated by using pre-equilibrium and equilibrium nuclear reaction models for nucleon induced reactions. While these calculations, the Hybrid Model, the Geometry Dependent Hybrid Model, the Full Exciton Model, the Cascade Exciton Model for pre-equilibrium reactions and the Weisskopf-Ewing Model for equilibrium reactions have been used. The calculated cross sections have been discussed and compared with the experimental data taken from Experimental Nuclear Reaction Data library.

  9. Reaction cross section calculation of some alkaline earth elements

    Directory of Open Access Journals (Sweden)

    Tel Eyyup

    2017-01-01

    Full Text Available Reaction cross section knowledge is crucial to application nuclear physics such as medical imaging, radiation shielding and material evaluations. Nuclear reaction codes can be used if the experimental data are unavailable or are improbably to be produced because of the experimental trouble. In this study, there action cross sections of some target alkaline earth elements have been calculated by using pre-equilibrium and equilibrium nuclear reaction models for nucleon induced reactions. While these calculations, the Hybrid Model, the Geometry Dependent Hybrid Model, the Full Exciton Model, the Cascade Exciton Model for pre-equilibrium reactions and the Weisskopf-Ewing Model for equilibrium reactions have been used. The calculated cross sections have been discussed and compared with the experimental data taken from Experimental Nuclear Reaction Data library.

  10. Formulating a low-alkalinity cement for radioactive waste repositories

    Energy Technology Data Exchange (ETDEWEB)

    Coumes, C. Cau Dit; Courtois, S.; Leclercq, S.; Bourbon, X

    2004-07-01

    A multi-annual research program has been launched in January 2003 by CEA, EDF and ANDRA in order to formulate and characterize low-alkalinity and low-heat cements which would be compatible with an underground waste repository environment. Four types of bindings have been investigated: binary blends of Portland cement and silica fume or metakaolin, as well as ternary blends of Portland cement, fly ash and silica fume or metakaolin. Promising results have been obtained with a mixture comprising 37.5% Portland cement, 32.5% silica fume, and 30% fly ash: pH of water in equilibrium with fully hydrated cement is below 11. Moreover, silica fume compensates for the low reactivity of fly ash, while fly ash allows to reduce water demand, heat release, and dimensional variations of cement pastes and mortars. (authors)

  11. The effect of drains on the alkalinity of agricultural soils

    International Nuclear Information System (INIS)

    Iqbal, M.A.; Butt, T.; Anwar-ul-Haque; Haroon, M.; Haq, I.U.

    2009-01-01

    The purpose of the study was to observe the effect of industrial and domestic drains on the nearby agricultural areas which are either irrigated or not by the waste water but are close to drains. For this purpose 48 soil samples were collected from the selected areas of Faisalabad and were analyzed for alkali metals like Na/sup +/, K/sup +/, Li/sup +/ and some alkaline earth metals like Ba/sup 2+/> Mg/sup 3+/> Na/sup +/> K/sup +/> Li/sup +/ the levels of Ba/sup +2/ and K/sup +/ were found higher than permissible levels in almost all the soil samples. It was also concluded that the agricultural areas near the industrial drain which are either irrigated or not by the industrial waste water are found highly contaminated with mobile alkali metals (K, Na etc.) and higher values of percentage salinity. (author)

  12. Chrono-amperometric studies in melt alkaline nitrates and chlorides

    International Nuclear Information System (INIS)

    Stemmelin, Jean-Claude

    1969-01-01

    This research thesis proposes a large overview of the electrochemical behaviour of a number of metals and alloys in melt alkaline chlorides and nitrates at various temperatures. These salts are generally pure but, in some experiments, contain humidity or gases. The author addresses and discusses all the reactions which may occur at the electrode between the salt decomposition potentials. After having recalled and commented some definitions and fundamental principles of thermodynamics and electrochemical kinetics, presented the methods (polarization curves, measurements and additional analysis), the experimental apparatus and the reference electrodes in melt salts, the author reports the results obtained with the studied melt salts, and proposes an interpretation of Log i/U curves

  13. Corrosion of silicon nitride in high temperature alkaline solutions

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Liyan, E-mail: liyan.qiu@cnl.ca; Guzonas, Dave A.; Qian, Jing

    2016-08-01

    The corrosion of silicon nitride (Si{sub 3}N{sub 4}) in alkaline solutions was studied at temperatures from 60 to 300 °C. Si{sub 3}N{sub 4} experienced significant corrosion above 100 °C. The release rates of silicon and nitrogen follow zero order reaction kinetics and increase with increasing temperature. The molar ratio of dissolved silicon and nitrogen species in the high temperature solutions is the same as that in the solid phase (congruent dissolution). The activation energy for silicon and nitrogen release rates is 75 kJ/mol which agrees well with that of silica dissolution. At 300 °C, the release of aluminum is observed and follows first order reaction kinetics while other minor constituents including Ti and Y are highly enriched on the corrosion films due to the low solubility of their oxides.

  14. The influence of complexing pharmaceutical compositions on alkaline phosphatase

    Science.gov (United States)

    Atyaksheva, L. F.; Chukhrai, E. S.; Stepina, N. D.; Novikova, N. N.; Yur'eva, E. A.

    2011-06-01

    It is established that the pharmaceutical compositions xydiphon, medifon, succimer, and EDTA, which are used as complexing agents for accelerating the excretion of heavy metals from human organism, at certain concentrations inhibit enzyme alkaline phosphatase (AP). It is concluded that xydiphon and EDTA have a noticeable effect on AP activity at concentrations over 0.01 mM; medifon and succimer, at concentrations of over 0.3-0.5 mM. The enzyme's inhibition constants and type of inhibition are determined. Xydiphon is found to manifest the highest affinity to AP ( K I = 0.35 mM). It is shown by kinetic analysis that dissociative chemoinactivation of the enzyme takes place under the action of complexing agents. The corresponding kinetic parameters are calculated.

  15. Many-body physics with alkaline-earth Rydberg lattices

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, R; Nath, R; Pohl, T [Max Planck Institute for the Physics of Complex Systems, Noethnitzer Strasse 38, 01187 Dresden (Germany); Millen, J; Jones, M P A, E-mail: rick@pks.mpg.de [Department of Physics, Durham University, Durham DH1 3LE (United Kingdom)

    2011-09-28

    We explore the prospects for confining alkaline-earth Rydberg atoms in an optical lattice via optical dressing of the secondary core-valence electron. Focussing on the particular case of strontium, we identify experimentally accessible magic wavelengths for simultaneous trapping of ground and Rydberg states. A detailed analysis of relevant loss mechanisms shows that the overall lifetime of such a system is limited only by the spontaneous decay of the Rydberg state, and is not significantly affected by photoionization or autoionization. The van der Waals C{sub 6} coefficients for the Sr(5sns {sup 1}S{sub 0}) Rydberg series are calculated, and we find that the interactions are attractive. Finally we show that the combination of magic-wavelength lattices and attractive interactions could be exploited to generate many-body Greenberger-Horne-Zeilinger states.

  16. A new method for alkaline dissolution of uranium metal foil

    International Nuclear Information System (INIS)

    Mondino, A.V.; Wilkinson, M.V.; Manzini, A.C.

    2001-01-01

    In order to develop a production process of 99 Mo by fission of low-enriched uranium, the first purification step, which consists of dissolution of a uranium metal foil target, was studied. It was found that alkaline NaClO gave good results, reaching the dissolution of up to 300 μm of uranium foil. The different conditions for the dissolution were studied and the optimum ones were found. The influence of NaClO and NaOH concentration, temperature, dissolving solution volume per unit of surface and dissolution time were investigated. During this step, a gas identified as H 2 , was generated, and a precipitate characterized as Na 2 U 2 O 7 was observed. A stoichiometric reaction for this uranium dissolution is proposed. (author)

  17. The Alto Paraguay Alkaline Province: petrographic, geochemical and geochronological characteristics

    International Nuclear Information System (INIS)

    Velazquez Fernandez, Victor

    1996-01-01

    The Alto Paraguay Province is located at the border of the State of Mato Grosso do Sul and Paraguay, between the coordinates 21 deg 10 ' to 23 deg 25 ' of Southern latitude and 57 deg 10 ' to 58 deg 00 ' , having the city of Porto Murtinho as the main reference point. The geotectonic domain of the area is governed by the precambric units of the Southern extreme of the Amazonic craton which developed a long and accentuated activity, giving rise to folds and important faults, that in several cases seem to have exerted an effective control of the magmatic manifestations. Radiometric data indicate that the emplacement of the syenitic bodies took place in the Permo-Triassic period, with a major incidence in the interval 260-240 Ma, representing thus, an important phase of alkaline magmatic affinity associated to the Parana Basin which is believed is to be unique, since the other known areas (Central, Amambay and Rio Apa Provinces, Paraguay, Velasco Province, Bolivia) are considerably younger (140-120 Ma). Syenitic rocks from the Alto Paraguay Province show wide variation in the ratio 87 Sr/ 86 Sr (0.703361 - 0.707734). Excluding the Cerro Boggiani rocks (0.703837-0.707734), values for the nepheline syenites (0.703361-0.703672) general lower than those of the other syenites types. Alkaline syenites cover the interval 0.703510- 0.703872, while quartz syenites and syenogranites are 0.704562 and 0.707076, respectively. geologic evidence, in addition to petrographic, geochemical and isotopic (Sr) data, suggest that the syenitic rocks have been derived from an unique mantelic parental liquid, by fractional crystallization and assimilation processes, which are assumed to be occurred during the emplacement of the magma in the crust. (author)

  18. Medium from X-rayed cultures induces DNA strand-breaks in non-irradiated HeLa cells

    International Nuclear Information System (INIS)

    Ikushima, T.; Okuyama, K.; Tanizaki, Y.

    2002-01-01

    There is growing evidence to indicate that several types of responses are induced by ionizing radiation in non-irradiated cells. Such bystander effects include the killing of non-irradiated cells, the induction of sister chromatid exchanges and chromosomal aberrations, and the induction of gene mutations and chromosomal instability and enhanced cell growth. In the present study, we assessed whether the medium from irradiated cultures can induce DNA strand-breaks in non-irradiated cells, using single-cell gel electrophoresis assay (comet assay). HeLa cells in culture were irradiated with 0.5 to 8 Gy of 140 kVp X-rays and one hour later, the medium was taken from the irradiated culture, passed through a filter and transferred to the parallel culture of non-irradiated HeLa cells as non-target cells. After incubation for 30 min, the comet assay was performed under alkaline and neutral conditions. Such treatments resulted in a dose-dependent increase in tail moment under either alkaline or neutral condition, indicating the induction of DNA single- or double-strand breaks, respectively. It was also shown that the clonogenic survival was reduced in the cells cultured in the medium from irradiated cultures. Such a change was not detected at all when medium alone was irradiated. These results provided disputed evidence that irradiated cells released certain genotoxic factor(s) into the culture medium that can induce DNA strand breaks leading to cell death. Our results suggest that physical contact between irradiated and non-irradiated cells may not be necessary for the bystander effects observed in this study. It appears that bystander responses may be mediated by multiple mechanisms

  19. In Vitro Determination of Bicarbonate Dosage to Alkalinize Local Anesthetics to Physiologic pH

    Science.gov (United States)

    1997-05-01

    Lofgren’s contributions extend beyond the initial synthesis of Lidocaine ; his systematic study of an extensive assortment of compounds laid the foundation...maximizing time to precipitation formation. This descriptive study investigated the alkalinization of four local anesthetic solutions ( Lidocaine ... Lidocaine with epinephrine solutions for epidural administration (1986). While the benefits of alkalinization appear to be well established, the formation

  20. Invited: A Stability Study of Alkali Doped PBI Membranes for Alkaline Electrolyzer Cells

    DEFF Research Database (Denmark)

    Jensen, Jens Oluf; Aili, David; Hansen, Martin Kalmar

    2014-01-01

    Alkaline fuel cells and electrolyzers are attracting increasing interest. This is to a large extent due to the broad selection of catalyst materials not based on resource limited and expensive noble metals. The first fuel cells in practical use were Francis Thomas Bacon’s based on an alkaline...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-12-01

    Performance and produced polymer evaluation of four alkaline-surfactant-polymer projects concluded that only one of the projects could have benefited from combining the alkaline-surfactant-polymer and gelation technologies. Cambridge, the 1993 Daqing, Mellott Ranch, and the Wardlaw alkaline-surfacant-polymer floods were studied. An initial gel treatment followed by an alkaline-surfactant-polymer flood in the Wardlaw field would have been a benefit due to reduction of fracture flow. Numerical simulation demonstrated that reducing the permeability of a high permeability zone of a reservoir with gel improved both waterflood and alkaline-surfactant-polymer flood oil recovery. A Minnelusa reservoir with both A and B sand production was simulated. A and B sands are separated by a shale layer. A sand and B sand waterflood oil recovery was improved by 196,000 bbls or 3.3% OOIP when a gel was placed in the B sand. Alkaline-surfactant-polymer flood oil recovery improvement over a waterflood was 392,000 bbls or 6.5% OOIP. Placing a gel into the B sand prior to an alkaline-surfactant-polymer flood resulted in 989,000 bbl or 16.4% OOIP more oil than only water injection. A sand and B sand alkaline-surfactant-polymer flood oil recovery was improved by 596,000 bbls or 9.9% OOIP when a gel was placed in the B sand.

  2. Isolation, identification and optimization of alkaline protease production by Candida viswanathii

    Directory of Open Access Journals (Sweden)

    Mandana Lotfi

    2014-03-01

    Conclusion: Due to the high demand for industrial enzymes in the Country and the high activity of alkaline proteases produced by strain. It seems that the native strain can achieve high production of alkaline proteases.These native strains could be resulted in the independence of our country in industrial enzymes production.

  3. Detergent insolubility of alkaline phosphatase during biosynthetic transport and endocytosis. Role of cholesterol

    NARCIS (Netherlands)

    Cerneus, D. P.; Ueffing, E.; Posthuma, G.; Strous, G. J.; van der Ende, A.

    1993-01-01

    Alkaline phosphatase is anchored to the outer leaflet of the plasma membrane by a covalently attached glycosyl-phosphatidylinositol anchor. We have studied the biosynthetic transport and endocytosis of alkaline phosphatase in the choriocarcinoma cell line BeWo, which endogenously expresses this

  4. When can ocean acidification impacts be detected from decadal alkalinity measurements?

    Science.gov (United States)

    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.

  5. Evaluation of hydraulic conductivities of bentonite and rock under hyper alkaline and nitrate conditions. 2

    International Nuclear Information System (INIS)

    Iriya, Keishiro; Fujii, Kensuke; Kubo, Hiroshi

    2003-02-01

    Circumstance of TRU waste repository shows alkaline condition due to leaching of cementitious materials. The waste containing significant soluble nitrate may changes ground water chemistry to high ion strength. Several experimental studies have been carried out in this study in order to assess quantitatively water conductivity of bentonite which is altered by hyper alkaline and nitrate. Modeling for previous results is carried out and several requirements to be defined are proposed. The conclusion of this study is summarized as below. Secondary minerals of bentonite alteration due to hyper alkaline with nitrate: 1) CSH and CAH were observed corresponding to solving montmorillonite in AWN solution. 2) Na 2 O Al 2 O 3 1.68SiO 2 generated from 90 days in batch experiment and it was observed in 360 days. Assessment of swelling and water conductivity changing by hyper alkaline with nitrate: 1) Little changing of water conductivity of bentonite was observed by saturated Ca(OH) 2 solution and hyper alkaline solution. The conductivity significantly increased by penetrating sodium nitrate solution. 2) Water conductivity of ion exchanged bentonite by hyper alkaline solution significantly increased. It increased more by penetrating AWN solution. Modeling of tuff alteration by hyper alkaline solution: 1) Flow through test is proposed since soluble velocity to hyper alkaline solution should be defined. (author)

  6. Constructing and screening a metagenomic library of a cold and alkaline extreme environment

    DEFF Research Database (Denmark)

    Glaring, Mikkel Andreas; Vester, Jan Kjølhede; Stougaard, Peter

    2017-01-01

    Natural cold or alkaline environments are common on Earth. A rare combination of these two extremes is found in the permanently cold (less than 6 °C) and alkaline (pH above 10) ikaite columns in the Ikka Fjord in Southern Greenland. Bioprospecting efforts have established the ikaite columns...

  7. 40 CFR 721.4668 - Hydrated alkaline earth metal salts of metalloid oxyanions.

    Science.gov (United States)

    2010-07-01

    ... metalloid oxyanions. 721.4668 Section 721.4668 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.4668 Hydrated alkaline earth metal salts of metalloid oxyanions. (a... hydrated alkaline earth metal salts of metalloid oxyanions (PMN P-94-1557) is subject to reporting under...

  8. Measurement of pH, alkalinity and acidity in ultra-soft waters | Lahav ...

    African Journals Online (AJOL)

    In the "blend" method, equilibrium chemistry data were used to calculate total acidity for each point based on the known total alkalinity, pH reading, temperature and ionic strength. The two methods gave excellent results (in terms of both repetition and accuracy) as compared to characterisation based on total alkalinity and ...

  9. Collaborative Manufacturing for Small-Medium Enterprises

    Science.gov (United States)

    Irianto, D.

    2016-02-01

    Manufacturing systems involve decisions concerning production processes, capacity, planning, and control. In a MTO manufacturing systems, strategic decisions concerning fulfilment of customer requirement, manufacturing cost, and due date of delivery are the most important. In order to accelerate the decision making process, research on decision making structure when receiving order and sequencing activities under limited capacity is required. An effective decision making process is typically required by small-medium components and tools maker as supporting industries to large industries. On one side, metal small-medium enterprises are expected to produce parts, components or tools (i.e. jigs, fixture, mold, and dies) with high precision, low cost, and exact delivery time. On the other side, a metal small- medium enterprise may have weak bargaining position due to aspects such as low production capacity, limited budget for material procurement, and limited high precision machine and equipment. Instead of receiving order exclusively, a small-medium enterprise can collaborate with other small-medium enterprise in order to fulfill requirements high quality, low manufacturing cost, and just in time delivery. Small-medium enterprises can share their best capabilities to form effective supporting industries. Independent body such as community service at university can take a role as a collaboration manager. The Laboratory of Production Systems at Bandung Institute of Technology has implemented shared manufacturing systems for small-medium enterprise collaboration.

  10. Study of the electroreduction of nitrate on copper in alkaline solution

    Energy Technology Data Exchange (ETDEWEB)

    Reyter, David [INRS Energie, Materiaux et Telecommunications, 1650 bd. Lionel Boulet, Varennes, Qc (Canada); Departement de Chimie, Universite du Quebec a Montreal, CP 8888, Montreal, Qc (Canada); Belanger, Daniel [Departement de Chimie, Universite du Quebec a Montreal, CP 8888, Montreal, Qc (Canada); Roue, Lionel [INRS Energie, Materiaux et Telecommunications, 1650 bd. Lionel Boulet, Varennes, Qc (Canada)

    2008-08-20

    The electrocatalytic activity of a Cu electrode for the electroreduction of nitrate in alkaline medium was investigated by linear sweep voltammetry at stationary and rotating disc electrodes. Nitrate-reduction products generated upon prolonged electrolyses at different potentials were quantified. In addition, adsorption phenomena associated with the nitrate electroreduction process were characterized by electrochemical quartz crystal microbalance (EQCM) experiments. This data revealed that nitrate electroreduction process strongly depends on the applied potential. Firstly, at ca. -0.9 V vs. Hg/HgO, the electroreduction of adsorbed nitrate anions to nitrite anions was identified as the rate-determining step of the nitrate electroreduction process. Between -0.9 and -1.1 V, nitrite is reduced to hydroxylamine. However, during long-term electrolyses, hydroxylamine is not detected and presumably because it is rapidly reduced to ammonia. At potential more negative than -1.1 V, nitrite is reduced to ammonia. At ca. -1.45 V, i.e. just before the hydrogen evolution reaction, the abrupt decrease of the cathodic current is due to the electrode poisoning by adsorbed hydrogen. In addition, during the first minutes of nitrate electrolysis, a decrease of the copper electrode activity was observed at the three investigated potentials (-0.9, -1.1 and -1.4 V). From polarization and EQCM measurements, this deactivation was attributed to the adsorption of nitrate-reduction products, blocking the electrode surface and slowing down the nitrate electroreduction rate. However, it was demonstrated that the Cu electrode can be reactivated by the periodic application of a square wave potential pulse at -0.5 V, which causes the desorption of poisoning species. (author)

  11. Approach of describing dynamic production of volatile fatty acids from sludge alkaline fermentation.

    Science.gov (United States)

    Wang, Dongbo; Liu, Yiwen; Ngo, Huu Hao; Zhang, Chang; Yang, Qi; Peng, Lai; He, Dandan; Zeng, Guangming; Li, Xiaoming; Ni, Bing-Jie

    2017-08-01

    In this work, a mathematical model was developed to describe the dynamics of fermentation products in sludge alkaline fermentation systems for the first time. In this model, the impacts of alkaline fermentation on sludge disintegration, hydrolysis, acidogenesis, acetogenesis, and methanogenesis processes are specifically considered for describing the high-level formation of fermentation products. The model proposed successfully reproduced the experimental data obtained from five independent sludge alkaline fermentation studies. The modeling results showed that alkaline fermentation largely facilitated the disintegration, acidogenesis, and acetogenesis processes and severely inhibited methanogenesis process. With the pH increase from 7.0 to 10.0, the disintegration, acidogenesis, and acetogenesis processes respectively increased by 53%, 1030%, and 30% while methane production decreased by 3800%. However, no substantial effect on hydrolysis process was found. The model also indicated that the pathway of acetoclastic methanogenesis was more severely inhibited by alkaline condition than that of hydrogentrophic methanogenesis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Serum creatinine and alkaline phosphatase levels are associated with severe chronic periodontitis.

    Science.gov (United States)

    Caúla, A L; Lira-Junior, R; Tinoco, E M B; Fischer, R G

    2015-12-01

    Periodontitis may alter systemic homeostasis and influence creatinine and alkaline phosphatase levels. Therefore, the aim of this study was to evaluate the relationship between severe chronic periodontitis and serum creatinine and alkaline phosphatase levels. One hundred patients were evaluated, 66 with severe chronic periodontitis (test group) and 34 periodontally healthy controls (control group). Medical, demographic and periodontal parameters were registered. Blood sample was collected after an overnight fast and serum creatinine and alkaline phosphatase levels were determined. There were significant differences between test and control groups in ethnicity, gender and educational level (p creatinine level (p creatinine and alkaline phosphatase levels. Severe chronic periodontitis was associated to lower creatinine and higher alkaline phosphatase levels. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Bone mineralisation in premature infants cannot be predicted from serum alkaline phosphatase or serum phosphate

    DEFF Research Database (Denmark)

    Faerk, J; Peitersen, Birgit; Petersen, S

    2002-01-01

    BACKGROUND: The bone mineral content of premature infants at term is lower than in mature infants at the same postconceptional age. Serum alkaline phosphatase and serum phosphate are often used as indicators of bone mineralisation. OBJECTIVE: To analyse the association between bone mineral content...... content was measured at term (mean gestational age 41 weeks) by dual energy x ray absorptiometry and corrected for body size. RESULTS: Serum alkaline phosphatase was significantly negatively associated with serum phosphate (p mineral content was not associated with mean serum alkaline...... and serum alkaline phosphatase and serum phosphate. METHODS: Serum alkaline phosphatase and phosphate were measured at weekly intervals during admission in 108 premature infants of gestational age below 32 weeks (mean (SD) gestational age 29 (2) weeks; mean (SD) birth weight 1129 (279) g). Bone mineral...

  14. Alkaline phosphatase levels in patients with coronary heart disease saliva and its relation with periodontal status

    Science.gov (United States)

    Yunita, Dina Suci; Masulili, Sri Lelyati C.; Tadjoedin, Fatimah M.; Radi, Basuni

    2017-02-01

    Coronary heart disease (CHD) is a disease that causes narrowing of the coronary arteries. Currently, there is a hypothesis regarding periodontal infection that increases risk for heart disease. Alkaline phosphatase (ALP) as a marker of inflammation will increase in atherosclerosis and periodontal disease. The objective of this research is analyzing the relationship between the levels of alkaline phosphatase in saliva with periodontal status in patients with CHD and non CHD. Here, saliva of 104 subjects were taken, each 1 ml, and levels of Alkaline Phosphatase was analyzed using Abbott ci4100 architect. We found that no significant difference of Alkaline Phosphatase levels in saliva between CHD patients and non CHD. Therefore, it can be concluded that Alkaline Phosphatase levels in patients with CHD saliva was higher than non CHD and no association between ALP levels with periodontal status.

  15. Scale-up of an alkaline protease from Bacillus pumilus MTCC 7514 utilizing fish meal as a sole source of nutrients.

    Science.gov (United States)

    Gupta, Rishikesh Kumar; Prasad, Dinesh; Sathesh, Jaykumar; Naidu, Ramachandra Boopathy; Kamini, Numbi Ramudu; Palanivel, Saravanan; Gowthaman, Marichetti Kuppuswami

    2012-09-01

    Fish meal grades SL1 and SL2 from Sardine (Sardinella longiceps) and NJ from Pink Perch (Nemipterus japonicas) were evaluated as a sole source of carbon and nitrogen in the medium for alkaline protease production by Bacillus pumilus MTCC 7514. The analysis of the fish meal suggests that the carbon and nitrogen contents in fish meal are sufficient to justify its choice as replacement for other nutrients. Protease production increased significantly (4,914 U/ml) in medium containing only fish meal, compared with the basal medium (2,646 U/ml). However, the elimination of inorganic salts from media reduced the protease productivity. In addition, all the three grades of fish meal yielded almost the same amounts of protease when employed as the sole source of carbon and nitrogen. Nevertheless, the best results were observed in fish meal SL1 medium. Furthermore, protease production was enhanced to 6,966 U/ml and 7,047 U/ml on scaling up from flask (4,914 U/ml) to 3.7 and 20 L fermenters, respectively, using fish meal (10 g/l). Similarly, the corresponding improvement in productivities over flask (102.38 U/ml/h) was 193.5 and 195.75 U/ml/h in 3.7 and 20 L fermenters, respectively. The crude protease was found to have dehairing ability in leather processing, which is bound to have great environmental benefits.

  16. Photonic-resonant left-handed medium

    International Nuclear Information System (INIS)

    Shen Jianqi

    2006-01-01

    A new scheme to realize simultaneously negative permittivity and permeability in a coherent atomic vapor medium (photonic-resonant material) via a coherent driving mechanism is suggested. It is verified that the atomic system coherently driven by a strong optical field will give rise to a negative refractive index in certain probe frequency ranges. One of the most remarkable features of the present scheme is such that a slab fabricated by the left-handed vapor medium is an ideal candidate for designing perfect lenses since the photonic-resonant atomic vapor cannot only exhibit an isotropic negative refractive index, but also provide a good impedance match at the air-medium interfaces

  17. Physical processes in the interstellar medium

    CERN Document Server

    Spitzer, Lyman

    2008-01-01

    Physical Processes in the Interstellar Medium discusses the nature of interstellar matter, with a strong emphasis on basic physical principles, and summarizes the present state of knowledge about the interstellar medium by providing the latest observational data. Physics and chemistry of the interstellar medium are treated, with frequent references to observational results. The overall equilibrium and dynamical state of the interstellar gas are described, with discussions of explosions produced by star birth and star death and the initial phases of cloud collapse leading to star formation.

  18. COUPLING THE ALKALINE-SURFACTANT-POLYMER TECHNOLOGY AND THE GELATION TECHNOLOGY TO MAXIMIZE OIL PRODUCTION

    Energy Technology Data Exchange (ETDEWEB)

    Malcolm Pitts; Jie Qui; Dan Wilson; Phil Dowling

    2004-05-01

    Gelation technologies have been developed to provide more efficient vertical sweep efficiencies for flooding naturally fractured oil reservoirs or more efficient areal sweep efficiency those with high permeability contrast ''thief zones''. The field proven alkaline-surfactant-polymer technology economically recovers 15% to 25% OOIP more oil than waterflooding in the swept pore space of an oil reservoir. However, alkaline-surfactant-polymer technology is not amenable to the naturally fractured reservoirs or those with thief zones because much of the injected solution bypasses the target pore space containing oil. The objective of this work is to investigate whether combining these two technologies could broaden the applicability of alkaline-surfactant-polymer flooding into these reservoirs. Fluid-fluid interaction with different gel chemical compositions and alkaline-surfactant-polymer solution with pH values ranging from 9.2 to 12.9 have been tested. Aluminum-polyacrylamide gels are not stable to alkaline-surfactant-polymer solutions at any pH. Chromium--polyacrylamide gels with polymer to chromium ion ratios of 25 or greater were stable to alkaline-surfactant-polymer solutions if solution pH was 10.6 or less. When the polymer to chromium ion was 15 or less, chromium-polyacrylamide gels were stable to alkaline-surfactant-polymer solutions with pH values up to 12.9. Chromium-xanthan gum gels were stable to alkaline-surfactant-polymer solutions with pH values of 12.9 at the polymer to chromium ion ratios tested. Silicate-polyacrylamide, resorcinol-formaldehyde, and sulfomethylated resorcinol-formaldehyde gels were also stable to alkaline-surfactant-polymer solutions with pH values ranging from 9.2 to 12.9. Iron-polyacrylamide gels were immediately destroyed when contacted with any of the alkaline-surfactant-polymer solutions with pH values of 9.2 to 12.9.

  19. Systematic review of the association between dietary acid load, alkaline water and cancer.

    Science.gov (United States)

    Fenton, Tanis R; Huang, Tian

    2016-06-13

    To evaluate the evidence for a causal relationship between dietary acid/alkaline and alkaline water for the aetiology and treatment of cancer. A systematic review was conducted on published and grey literature separately for randomised intervention and observational studies with either varying acid-base dietary intakes and/or alkaline water with any cancer outcome or for cancer treatment. Incidence of cancer and outcomes of cancer treatment. 8278 citations were identified, and 252 abstracts were reviewed; 1 study met the inclusion criteria and was included in this systematic review. No randomised trials were located. No studies were located that examined dietary acid or alkaline or alkaline water for cancer treatment. The included study was a cohort study with a low risk of bias. This study revealed no association between the diet acid load with bladder cancer (OR=1.15: 95% CI 0.86 to 1.55, p=0.36). No association was found even among long-term smokers (OR=1.72: 95% CI 0.96 to 3.10, p=0.08). Despite the promotion of the alkaline diet and alkaline water by the media and salespeople, there is almost no actual research to either support or disprove these ideas. This systematic review of the literature revealed a lack of evidence for or against diet acid load and/or alkaline water for the initiation or treatment of cancer. Promotion of alkaline diet and alkaline water to the public for cancer prevention or treatment is not justified. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  20. Identification and characterization of miRNAs and targets in flax (Linum usitatissimum) under saline, alkaline, and saline-alkaline stresses.

    Science.gov (United States)

    Yu, Ying; Wu, Guangwen; Yuan, Hongmei; Cheng, Lili; Zhao, Dongsheng; Huang, Wengong; Zhang, Shuquan; Zhang, Liguo; Chen, Hongyu; Zhang, Jian; Guan, Fengzhi

    2016-05-27

    MicroRNAs (miRNAs) play a critical role in responses to biotic and abiotic stress and have been characterized in a large number of plant species. Although flax (Linum usitatissimum L.) is one of the most important fiber and oil crops worldwide, no reports have been published describing flax miRNAs (Lus-miRNAs) induced in response to saline, alkaline, and saline-alkaline stresses. In this work, combined small RNA and degradome deep sequencing was used to analyze flax libraries constructed after alkaline-salt stress (AS2), neutral salt stress (NSS), alkaline stress (AS), and the non-stressed control (CK). From the CK, AS, AS2, and NSS libraries, a total of 118, 119, 122, and 120 known Lus-miRNAs and 233, 213, 211, and 212 novel Lus-miRNAs were isolated, respectively. After assessment of differential expression profiles, 17 known Lus-miRNAs and 36 novel Lus-miRNAs were selected and used to predict putative target genes. Gene ontology term enrichment analysis revealed target genes that were involved in responses to stimuli, including signaling and catalytic activity. Eight Lus-miRNAs were selected for analysis using qRT-PCR to confirm the accuracy and reliability of the miRNA-seq results. The qRT-PCR results showed that changes in stress-induced expression profiles of these miRNAs mirrored expression trends observed using miRNA-seq. Degradome sequencing and transcriptome profiling showed that expression of 29 miRNA-target pairs displayed inverse expression patterns under saline, alkaline, and saline-alkaline stresses. From the target prediction analysis, the miR398a-targeted gene codes for a copper/zinc superoxide dismutase, and the miR530 has been shown to explicitly target WRKY family transcription factors, which suggesting that these two micRNAs and their targets may significant involve in the saline, alkaline, and saline-alkaline stress response in flax. Identification and characterization of flax miRNAs, their target genes, functional annotations, and gene