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Sample records for stable subtilisin-like alkaline

  1. Genomic and exoproteomic analyses of cold- and alkaline-adapted bacteria reveal an abundance of secreted subtilisin-like proteases.

    Science.gov (United States)

    Lylloff, Jeanette E; Hansen, Lea B S; Jepsen, Morten; Sanggaard, Kristian W; Vester, Jan K; Enghild, Jan J; Sørensen, Søren J; Stougaard, Peter; Glaring, Mikkel A

    2016-03-01

    Proteases active at low temperature or high pH are used in many commercial applications, including the detergent, food and feed industries, and bacteria specifically adapted to these conditions are a potential source of novel proteases. Environments combining these two extremes are very rare, but offer the promise of proteases ideally suited to work at both high pH and low temperature. In this report, bacteria from two cold and alkaline environments, the ikaite columns in Greenland and alkaline ponds in the McMurdo Dry Valley region, Antarctica, were screened for extracellular protease activity. Two isolates, Arsukibacterium ikkense from Greenland and a related strain, Arsukibacterium sp. MJ3, from Antarctica, were further characterized with respect to protease production. Genome sequencing identified a range of potential extracellular proteases including a number of putative secreted subtilisins. An extensive liquid chromatography-tandem mass spectrometry analysis of proteins secreted by A. ikkense identified six subtilisin-like proteases as abundant components of the exoproteome in addition to other peptidases potentially involved in complete degradation of extracellular protein. Screening of Arsukibacterium genome libraries in Escherichia coli identified two orthologous secreted subtilisins active at pH 10 and 20 °C, which were also present in the A. ikkense exoproteome. Recombinant production of both proteases confirmed the observed activity. © 2016 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  2. Purification and molecular characterization of subtilisin-like alkaline protease BPP-A from Bacillus pumilus strain MS-1.

    Science.gov (United States)

    Miyaji, T; Otta, Y; Nakagawa, T; Watanabe, T; Niimura, Y; Tomizuka, N

    2006-03-01

    The present study was conducted by screening zein-degrading bacteria in an attempt to obtain zein-degrading protease. Soil bacteria were screened by formation of a clear zone on zein plates. Characterization of a zein-degrading bacterium indicated a taxonomic affiliation to Bacillus pumilus, and was named MS-1 strain. The strain produced two different types of extracellular proteases, BPP-A and BPP-B. In this study, we purified and characterized BPP-A because it exhibited a higher ability to hydrolyze zein than BPP-B. When casein was used as the substrate, the optimal pH for BPP-A was 11.0. In BPP-A, zein was better substrate than casein at pH 13.0, whereas casein was better one than zein at pH 11.0. The bppA gene encoded a 383-amino acid pre-pro form of BPP-A, and mature BPP-A contained 275 amino acid residues. It was concluded that BPP-A belonged to the subtilisin family. A zein-degrading bacterium assigned to B. pumilus produced two different types of extracellular proteases, BPP-A and BPP-B. BPP-A exhibited an ability to hydrolyze zein in an extreme alkaline condition. This is a first report on screening for zein-degrading micro-organisms. The subtilisin-like protease BPP-A is possible to utilize as an industrial enzyme for the production of zein hydrolysates.

  3. Homology modelling and protein engineering strategy of subtilases, the family of subtilisin-like serine proteinases

    NARCIS (Netherlands)

    Siezen, Roland J.; Vos, Willem M. de; Leunissen, Jack A.M.; Dijkstra, Bauke W.

    1991-01-01

    Subtilases are members of the family of subtilisin-like serine proteases. Presently, >50 subtilases are known, >40 of which with their complete amino acid sequences. We have compared these sequences and the available three-dimensional structures (subtilisin BPN', subtilisin Carlsberg, thermitase and

  4. HOMOLOGY MODELING AND PROTEIN ENGINEERING STRATEGY OF SUBTILASES, THE FAMILY OF SUBTILISIN-LIKE SERINE PROTEINASES

    NARCIS (Netherlands)

    SIEZEN, RJ; DEVOS, WM; LEUNISSEN, JAM

    1991-01-01

    Subtilases are members of the family of subtilisin-like serine proteases. Presently, > 50 subtilases are known, > 40 of which with their complete amino acid sequences. We have compared these sequences and the available three-dimensional structures (subtilisin BPN', subtilisin Carlsberg, thermitase

  5. The cell envelope subtilisin-like proteinase is a virulence determinant for Streptococcus suis

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    Gottschalk Marcelo

    2010-02-01

    Full Text Available Abstract Background Streptococcus suis is a major swine pathogen and zoonotic agent that mainly causes septicemia, meningitis, and endocarditis. It has recently been suggested that proteinases produced by S. suis (serotype 2 are potential virulence determinants. In the present study, we screened a S. suis mutant library created by the insertion of Tn917 transposon in order to isolate a mutant deficient in a cell surface proteinase. We characterized the gene and assessed the proteinase for its potential as a virulence factor. Results Two mutants (G6G and M3G possessing a single Tn917 insertion were isolated. The affected gene coded for a protein (SSU0757 that shared a high degree of identity with Streptococccus thermophilus PrtS (95.9% and, to a lesser extent, with Streptococcus agalactiae CspA (49.5%, which are cell surface serine proteinases. The SSU0757 protein had a calculated molecular mass of 169.6 kDa and contained the catalytic triad characteristic of subtilisin family proteinases: motif I (Asp200, motif II (His239, and motif III (Ser568. SSU0757 also had the Gram-positive cell wall anchoring motif (Leu-Pro-X-Thr-Gly at the carboxy-terminus, which was followed by a hydrophobic domain. All the S. suis isolates tested, which belonged to different serotypes, possessed the gene encoding the SSU0757 protein. The two mutants devoid of subtilisin-like proteinase activity had longer generation times and were more susceptible to killing by whole blood than the wild-type parent strain P1/7. The virulence of the G6G and M3G mutants was compared to the wild-type strain in the CD1 mouse model. Significant differences in mortality rates were noted between the P1/7 group and the M3G and G6G groups (p Conclusion In summary, we identified a gene coding for a cell surface subtilisin-like serine proteinase that is widely distributed in S. suis. Evidences were brought for the involvement of this proteinase in S. suis virulence.

  6. Flexibility of cold- and heat-adapted subtilisin-like serine proteinases evaluated with fluorescence quenching and molecular dynamics

    DEFF Research Database (Denmark)

    Sigtryggsdóttir, Asta Rós; Papaleo, Elena; Thorbjarnardóttir, Sigríður H.

    2014-01-01

    activity of cold adapted enzymes when compared to homologues from thermophiles, reflects their higher molecular flexibility. To assess a potential difference in molecular flexibility between the two homologous proteinases, we have measured their Trp fluorescence quenching by acrylamide at different......The subtilisin-like serine proteinases, VPR, from a psychrotrophic Vibrio species and aqualysin I (AQUI) from the thermophile Thermus aquaticus, are structural homologues, but differ significantly with respect to stability and catalytic properties. It has been postulated that the higher catalytic...... to Trp (Y191W). A lower quenching effect of acrylamide on the intrinsic fluorescence of the thermophilic AQUI_Y191W was observed at all temperatures measured (10-55°C), suggesting that it possesses a more rigid structure than VPR. The MD analysis (Cα rmsf profiles) showed that even though VPR and AQUI...

  7. Isolation and identification of an extracellular subtilisin-like serine protease secreted by the bat pathogen Pseudogymnoascus destructans.

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    Evan L Pannkuk

    Full Text Available White nose syndrome (WNS is a cutaneous fungal disease of bats. WNS is responsible for unprecedented mortalities in North American cave bat populations. There have been few descriptions of enzyme activities that may function in WNS host/pathogen interactions, while no study has isolated and described secreted proteases. To address the hypothesis that Pseudogymnoascus destructans secretes extracellular proteases that function in wing necrosis during WNS infection, the object of this study was to culture P. destructans on various media, then isolate and structurally identify those proteases accumulated stably in the culture medium. We found a single dominant protease activity on minimal nutrient broth enriched with protein substrates, which was strongly inhibited by phenylmethylsulfonyl fluoride. This P. destructans serine protease (PdSP1 was isolated by preparative isoelectric focusing and concanavalin A lectin affinity chromatography. PdSP1 showed a molecular weight 27,900 (estimated by SDS-PAGE, broad pH optimum 6-8, and temperature optimum 60°C. Structural characterization of PdSP1 by MALDI-TOF MS, Orbitrap MS/MS, and Edman amino-terminal peptide sequencing matched it directly to a hypothetical protein accession from the sequenced P. destructans genome that is further identified as a MEROPS family S8A subtilisin-like serine peptidase. Two additional isoforms, PdSP2 and PdSP3, were identified in the P. destructans genome with 90% and 53% homology, respectively. P. destructans S8A serine proteases showed closer sequence conservation to P. pannorum and plant pathogenic fungi than to human pathogenic dermatophytes. Peptide-specific polyclonal antibodies developed from the PdSP1 sequence detected the protein in western blots. These subtilisin-like serine proteases are candidates for further functional studies in WNS host-pathogen interaction.

  8. Isolation and identification of an extracellular subtilisin-like serine protease secreted by the bat pathogen Pseudogymnoascus destructans.

    Science.gov (United States)

    Pannkuk, Evan L; Risch, Thomas S; Savary, Brett J

    2015-01-01

    White nose syndrome (WNS) is a cutaneous fungal disease of bats. WNS is responsible for unprecedented mortalities in North American cave bat populations. There have been few descriptions of enzyme activities that may function in WNS host/pathogen interactions, while no study has isolated and described secreted proteases. To address the hypothesis that Pseudogymnoascus destructans secretes extracellular proteases that function in wing necrosis during WNS infection, the object of this study was to culture P. destructans on various media, then isolate and structurally identify those proteases accumulated stably in the culture medium. We found a single dominant protease activity on minimal nutrient broth enriched with protein substrates, which was strongly inhibited by phenylmethylsulfonyl fluoride. This P. destructans serine protease (PdSP1) was isolated by preparative isoelectric focusing and concanavalin A lectin affinity chromatography. PdSP1 showed a molecular weight 27,900 (estimated by SDS-PAGE), broad pH optimum 6-8, and temperature optimum 60°C. Structural characterization of PdSP1 by MALDI-TOF MS, Orbitrap MS/MS, and Edman amino-terminal peptide sequencing matched it directly to a hypothetical protein accession from the sequenced P. destructans genome that is further identified as a MEROPS family S8A subtilisin-like serine peptidase. Two additional isoforms, PdSP2 and PdSP3, were identified in the P. destructans genome with 90% and 53% homology, respectively. P. destructans S8A serine proteases showed closer sequence conservation to P. pannorum and plant pathogenic fungi than to human pathogenic dermatophytes. Peptide-specific polyclonal antibodies developed from the PdSP1 sequence detected the protein in western blots. These subtilisin-like serine proteases are candidates for further functional studies in WNS host-pathogen interaction.

  9. Crystallization of the virulent and benign subtilisin-like proteases from the ovine footrot pathogen Dichelobacter nodosus

    International Nuclear Information System (INIS)

    Wong, Wilson; Kennan, Ruth M.; Rosado, Carlos J.; Rood, Julian I.; Whisstock, James C.; Porter, Corrine J.

    2010-01-01

    The subtilisin-like proteases AprV2 and BprV from virulent strains and AprB2 and BprB from benign strains of D. nodosus have been crystallized and X-ray diffraction data have been collected to 2.0, 2.0, 1.7 and 1.8 Å resolution, respectively. Dichelobacter nodosus is the principal causative agent of ovine footrot, a disease of significant economic importance to the sheep industry. D. nodosus secretes a number of subtilisin-like serine proteases which mediate tissue damage and presumably contribute to the pathogenesis of footrot. Strains causing virulent footrot secrete the proteases AprV2, AprV5 and BprV and strains causing benign footrot secrete the closely related proteases AprB2, AprB5 and BprB. Here, the cloning, purification and crystallization of AprV2, AprB2, BprV and BprB are reported. Crystals of AprV2 and AprB2 diffracted to 2.0 and 1.7 Å resolution, respectively. The crystals of both proteases belonged to space group P1, with unit-cell parameters a = 43.1, b = 46.0, c = 47.2 Å, α = 97.8, β = 115.2, γ = 115.2° for AprV2 and a = 42.7, b = 45.8, c = 45.7 Å, α = 98.4, β = 114.0, γ = 114.6° for AprB2. Crystals of BprV and BprB diffracted to 2.0 and 1.8 Å resolution, respectively. The crystals of both proteases belonged to space group P2 1 , with unit-cell parameters a = 38.5, b = 89.6, c = 47.7 Å, β = 113.6° for BprV and a = 38.5, b = 90.5, c = 44.1 Å, β = 109.9° for BprB. The crystals of all four proteases contained one molecule in the asymmetric unit, with a solvent content ranging from 36 to 40%

  10. The role of salt bridges on the temperature adaptation of aqualysin I, a thermostable subtilisin-like proteinase.

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    Jónsdóttir, Lilja B; Ellertsson, Brynjar Ö; Invernizzi, Gaetano; Magnúsdóttir, Manuela; Thorbjarnardóttir, Sigríður H; Papaleo, Elena; Kristjánsson, Magnús M

    2014-12-01

    Differences in salt bridges are believed to be a structural hallmark of homologous enzymes from differently temperature-adapted organisms. Nevertheless, the role of salt bridges on structural stability is still controversial. While it is clear that most buried salt bridges can have a functional or structural role, the same cannot be firmly stated for ion pairs that are exposed on the protein surface. Salt bridges, found in X-ray structures, may not be stably formed in solution as a result of high flexibility or high desolvation penalty. More studies are thus needed to clarify the picture on salt bridges and temperature adaptation. We contribute here to this scenario by combining atomistic simulations and experimental mutagenesis of eight mutant variants of aqualysin I, a thermophilic subtilisin-like proteinase, in which the residues involved in salt bridges and not conserved in a psychrophilic homolog were systematically mutated. We evaluated the effects of those mutations on thermal stability and on the kinetic parameters. Overall, we show here that only few key charged residues involved in salt bridges really contribute to the enzyme thermal stability. This is especially true when they are organized in networks, as here attested by the D17N mutation, which has the most remarkable effect on stability. Other mutations had smaller effects on the properties of the enzyme indicating that most of the isolated salt bridges are not a distinctive trait related to the enhanced thermal stability of the thermophilic subtilase. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. A homolog of Subtilisin-like Proprotein Convertase 7 is essential to anterior neural development in Xenopus.

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    Sema Senturker

    Full Text Available BACKGROUND: Subtilisin-like Proprotein Convertase 7 (SPC7 is a member of the subtilisin/kexin family of pro-protein convertases. It cleaves many pro-proteins to release their active proteins, including members of the bone morphogenetic protein (BMP family of signaling molecules. Other SPCs are known to be required during embryonic development but corresponding data regarding SPC7 have not been reported previously. METHODOLOGY/PRINCIPAL FINDINGS: We demonstrated that Xenopus SPC7 (SPC7 was expressed predominantly in the developing brain and eye, throughout the neural plate initially, then more specifically in the lens and retina primordia as development progressed. Since no prior functional information has been reported for SPC7, we used gain- and loss-of-function experiments to investigate the possibility that it may also convey patterning or tissue specification information similarly to Furin, SPC4, and SPC6. Overexpression of SPC7 was without effect. In contrast, injection of SPC7 antisense morpholino oligonucleotides (MO into a single blastomere at the 2- or 4-cell stage produced marked disruption of head structures; anophthalmia was salient. Bilateral injections suppressed head and eye formation completely. In parallel with suppression of eye and brain development by SPC7 knockdown, expression of early anterior neural markers (Sox2, Otx2, Rx2, and Pax6 and late eye-specific markers (β-Crystallin and Opsin, and of BMP target genes such as Tbx2 and Tbx3, was reduced or eliminated. Taken together, these findings suggest a critical role for SPC7-perhaps, at least in part, due to activation of one or more BMPs-in early patterning of the anterior neural plate and its derivatives. CONCLUSION/SIGNIFICANCE: SPC7 is required for normal development of the eye and brain, possibly through processing BMPs, though other potential substrates cannot be excluded.

  12. A Homolog of Subtilisin-Like Proprotein Convertase 7 Is Essential to Anterior Neural Development in Xenopus

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    Senturker, Sema; Thomas, John Terrig; Mateshaytis, Jennifer; Moos, Malcolm

    2012-01-01

    Background Subtilisin-like Proprotein Convertase 7 (SPC7) is a member of the subtilisin/kexin family of pro-protein convertases. It cleaves many pro-proteins to release their active proteins, including members of the bone morphogenetic protein (BMP) family of signaling molecules. Other SPCs are known to be required during embryonic development but corresponding data regarding SPC7 have not been reported previously. Methodology/Principal Findings We demonstrated that Xenopus SPC7 (SPC7) was expressed predominantly in the developing brain and eye, throughout the neural plate initially, then more specifically in the lens and retina primordia as development progressed. Since no prior functional information has been reported for SPC7, we used gain- and loss-of-function experiments to investigate the possibility that it may also convey patterning or tissue specification information similarly to Furin, SPC4, and SPC6. Overexpression of SPC7 was without effect. In contrast, injection of SPC7 antisense morpholino oligonucleotides (MO) into a single blastomere at the 2- or 4-cell stage produced marked disruption of head structures; anophthalmia was salient. Bilateral injections suppressed head and eye formation completely. In parallel with suppression of eye and brain development by SPC7 knockdown, expression of early anterior neural markers (Sox2, Otx2, Rx2, and Pax6) and late eye-specific markers (β-Crystallin and Opsin), and of BMP target genes such as Tbx2 and Tbx3, was reduced or eliminated. Taken together, these findings suggest a critical role for SPC7–perhaps, at least in part, due to activation of one or more BMPs–in early patterning of the anterior neural plate and its derivatives. Conclusion/Significance SPC7 is required for normal development of the eye and brain, possibly through processing BMPs, though other potential substrates cannot be excluded. PMID:22761776

  13. 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 ...

  14. 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

  15. Oxidant and solvent stable alkaline protease from Aspergillus flavus ...

    African Journals Online (AJOL)

    The increase in agricultural practices has necessitated the judicious use of agricultural wastes into value added products. In this study, an extracellular, organic solvent and oxidant stable, serine protease was produced by Aspergillus flavus MTCC 9952 under solid state fermentation. Maximum protease yield was obtained ...

  16. Preparation and performance evaluation of novel alkaline stable anion exchange membranes

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    Irfan, Muhammad; Bakangura, Erigene; Afsar, Noor Ul; Hossain, Md. Masem; Ran, Jin; Xu, Tongwen

    2017-07-01

    Novel alkaline stable anion exchange membranes are prepared from various amounts of N-methyl dipicolylamine (MDPA) and brominated poly (2,6-dimethyl-1,4-phenylene oxide) (BPPO). The dipicolylamine and MDPA are synthesized through condensation reaction and confirmed by 1H NMR spectroscopy. The morphologies of prepared membranes are investigated by atomic force microscopy (AFM), fourier transform infrared spectroscopy (FTIR), 1H NMR spectroscopy and scanning electron microscopy (SEM). The electrochemical and physical properties of AEMs are tested comprising water uptake (WU), ion exchange capacity (IEC), alkaline stability, linear expansion ratio (LER), thermal stability and mechanical stability. The obtained hydroxide conductivity of MDPA-4 is 66.5 mS/cm at 80 °C. The MDPA-4 membrane shows good alkaline stability, high hydroxide conductivity, low methanol permeability (3.43 × 10-7 cm2/s), higher selectivity (8.26 × 107 mS s/cm3), less water uptake (41.1%) and lower linear expansion (11.1%) despite of high IEC value (1.62 mmol/g). The results prove that MDPA membranes have great potential application in anion exchange membrane fuel cell.

  17. Plasmodium subtilisin-like protease 1 (SUB1): insights into the active-site structure, specificity and function of a pan-malaria drug target.

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    Withers-Martinez, Chrislaine; Suarez, Catherine; Fulle, Simone; Kher, Samir; Penzo, Maria; Ebejer, Jean-Paul; Koussis, Kostas; Hackett, Fiona; Jirgensons, Aigars; Finn, Paul; Blackman, Michael J

    2012-05-15

    Release of the malaria merozoite from its host erythrocyte (egress) and invasion of a fresh cell are crucial steps in the life cycle of the malaria pathogen. Subtilisin-like protease 1 (SUB1) is a parasite serine protease implicated in both processes. In the most dangerous human malarial species, Plasmodium falciparum, SUB1 has previously been shown to have several parasite-derived substrates, proteolytic cleavage of which is important both for egress and maturation of the merozoite surface to enable invasion. Here we have used molecular modelling, existing knowledge of SUB1 substrates, and recombinant expression and characterisation of additional Plasmodium SUB1 orthologues, to examine the active site architecture and substrate specificity of P. falciparum SUB1 and its orthologues from the two other major human malaria pathogens Plasmodium vivax and Plasmodium knowlesi, as well as from the rodent malaria species, Plasmodium berghei. Our results reveal a number of unusual features of the SUB1 substrate binding cleft, including a requirement to interact with both prime and non-prime side residues of the substrate recognition motif. Cleavage of conserved parasite substrates is mediated by SUB1 in all parasite species examined, and the importance of this is supported by evidence for species-specific co-evolution of protease and substrates. Two peptidyl alpha-ketoamides based on an authentic PfSUB1 substrate inhibit all SUB1 orthologues examined, with inhibitory potency enhanced by the presence of a carboxyl moiety designed to introduce prime side interactions with the protease. Our findings demonstrate that it should be possible to develop 'pan-reactive' drug-like compounds that inhibit SUB1 in all three major human malaria pathogens, enabling production of broad-spectrum antimalarial drugs targeting SUB1. Copyright © 2012 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

  18. The subtilisin-like protease AprV2 is required for virulence and uses a novel disulphide-tethered exosite to bind substrates.

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    Ruth M Kennan

    Full Text Available Many bacterial pathogens produce extracellular proteases that degrade the extracellular matrix of the host and therefore are involved in disease pathogenesis. Dichelobacter nodosus is the causative agent of ovine footrot, a highly contagious disease that is characterized by the separation of the hoof from the underlying tissue. D. nodosus secretes three subtilisin-like proteases whose analysis forms the basis of diagnostic tests that differentiate between virulent and benign strains and have been postulated to play a role in virulence. We have constructed protease mutants of D. nodosus; their analysis in a sheep virulence model revealed that one of these enzymes, AprV2, was required for virulence. These studies challenge the previous hypothesis that the elastase activity of AprV2 is important for disease progression, since aprV2 mutants were virulent when complemented with aprB2, which encodes a variant that has impaired elastase activity. We have determined the crystal structures of both AprV2 and AprB2 and characterized the biological activity of these enzymes. These data reveal that an unusual extended disulphide-tethered loop functions as an exosite, mediating effective enzyme-substrate interactions. The disulphide bond and Tyr92, which was located at the exposed end of the loop, were functionally important. Bioinformatic analyses suggested that other pathogenic bacteria may have proteases that utilize a similar mechanism. In conclusion, we have used an integrated multidisciplinary combination of bacterial genetics, whole animal virulence trials in the original host, biochemical studies, and comprehensive analysis of crystal structures to provide the first definitive evidence that the extracellular secreted proteases produced by D. nodosus are required for virulence and to elucidate the molecular mechanism by which these proteases bind to their natural substrates. We postulate that this exosite mechanism may be used by proteases produced by

  19. Relationship between serum heat-stable alkaline phosphatase level and pregnancy

    International Nuclear Information System (INIS)

    Cao Guoxian; Xiao Weihong; Yu Huixin; Li Weiyi; Huang Xuquan

    1998-01-01

    Serum heat-stable alkaline phosphatase (HSAP) level in 649 cases of normal pregnancy and 164 cases of high-risk pregnancy is measured by radioimmunoassay (RIA). The results indicate that the HSAP level in normal pregnancy increased proportionally with gestation weeks (r = 0.9843). In 33 cases of pregnancy induced hypertension and 21 cases of intrauterine fetal growth retardation, the HSAP level is significantly low. In 7 cases of neonatal asphyxia and 26 cases of fetal distress, the HSAP level in the mother's serum is also low. In 53 cases of intrahepatic cholestasis of pregnancy, the HSAP level is similar to those of normal pregnancy. This study illustrates that HSAP RIA can play an important role in the evaluation of placental function and fetal prognosis for cases of high-risk pregnancy

  20. Characteristics of mutants designed to incorporate a new ion pair into the structure of a cold adapted subtilisin-like serine proteinase.

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    Sigurdardóttir, Anna Gudný; Arnórsdóttir, Jóhanna; Thorbjarnardóttir, Sigrídur H; Eggertsson, Gudmundur; Suhre, Karsten; Kristjánsson, Magnús M

    2009-03-01

    Structural comparisons of VPR, a subtilisin-like serine proteinase from a psychrotrophic Vibrio species and a thermophilic homologue, aqualysin I, have led us to hypothesize about the roles of different residues in the temperature adaptation of the enzymes. Some of these hypotheses are now being examined by analysis of mutants of the enzymes. The selected substitutions are believed to increase the stability of the cold adapted enzyme based on structural analysis of the thermostable structure. We report here on mutants, which were designed to incorporate an ion pair into the structure of VPR. The residues Asp17 and Arg259 are assumed to form an ion pair in aqualysin I. The cold adapted VPR contains Asn (Asn15) and Lys (Lys257) at corresponding sites in its structure. In VPR, Asn 15 is located on a surface loop with its side group pointing towards the side chain of Lys257. By substituting Asn15 by Asp (N15D) it was considered feasible that a salt bridge would form between the oppositely charged groups. To mimic further the putative salt bridge from the thermophile enzyme the corresponding double mutant (N15D/K257R) was also produced. The N15D mutation increased the thermal stability of VPR by approximately 3 degrees C, both in T(50%) and T(m). Addition of the K257R mutation did not however, increase the stability of the double mutant any further. Despite this stabilization of the VPR mutants the catalytic activity (k(cat)) against the substrate Suc-AAPF-NH-Np was increased in the mutants. Molecular dynamics simulations on wild type and the two mutant proteins suggested that indeed a salt bridge was formed in both cases. Furthermore, a truncated form of the N15D mutant (N15DDeltaC) was produced, lacking a 15 residue long C-terminal extended sequence not present in the thermophilic enzyme. In wild type VPR this supposedly moveable, negatively charged arm on the protein molecule might interfere with the new salt bridge introduced as a result of the N15D mutation

  1. Purification and characterization of thiol dependent, oxidation-stable serine alkaline protease from thermophilic Bacillus sp.

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    Aysha Kamran

    2015-06-01

    Full Text Available Alkaline serine protease was purified to homogeneity from culture supernatant of a thermophilic, alkaliphilic Bacillus sp. by 80% ammonium sulphate precipitation followed by CM-cellulose and DEAE-cellulose ion exchange column chromatography. The enzyme was purified up to 16.5-fold with 6900 U/mg activity. The protease exhibited maximum activity towards casein at pH 8.0 and at 80 °C. The enzyme was stable at pH 8.0 and 80 °C temperature up to 2 h. The Ca2+ and Mn2+ enhanced the proteolytic activity up to 44% and 36% as compared to control, respectively. However, Zn2+, K+, Ba2+, Co2+, Hg2+ and Cu2+ significantly reduced the enzyme activity. PMSF (phenyl methyl sulphonyl fluoride completely inhibited the protease activity, whereas the activity of protease was stimulated up to two folds in the presence of 5 mM 2-mercaptoethanol. The enzyme was also stable in surfactant (Tween-80 and other commercial detergents (SDS, Triton X-100.

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

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    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.

  3. Towards a stable ion-solvating polymer electrolyte for advanced alkaline water electrolysis

    DEFF Research Database (Denmark)

    Aili, David; Wright, Andrew G.; Kraglund, Mikkel Rykær

    2017-01-01

    Advanced alkaline water electrolysis using ion-solvating polymer membranes as electrolytes represents a new direction in the field of electrochemical hydrogen production. Polybenzimidazole membranes equilibrated in aqueous KOH combine the mechanical robustness and gas-tightness of a polymer...... stability in alkaline environments. The novel electrolytes are extensively characterized with respect to physicochemical and electrochemical properties and the chemical stability is assessed in 0-50 wt% aqueous KOH for more than 6 months at 88 degrees C. In water electrolysis tests using porous 3...

  4. Substantial decrease in cell wall α-1,3-glucan caused by disruption of the kexB gene encoding a subtilisin-like processing protease in Aspergillus oryzae.

    Science.gov (United States)

    Mizutani, Osamu; Shiina, Matsuko; Yoshimi, Akira; Sano, Motoaki; Watanabe, Takeshi; Yamagata, Youhei; Nakajima, Tasuku; Gomi, Katsuya; Abe, Keietsu

    2016-09-01

    Disruption of the kexB encoding a subtilisin-like processing protease in Aspergillus oryzae (ΔkexB) leads to substantial morphological defects when the cells are grown on Czapek-Dox agar plates. We previously found that the disruption of kexB causes a constitutive activation of the cell wall integrity pathway. To understand how the disruption of the kexB affects cell wall organization and components, we analyzed the cell wall of ΔkexB grown on the plates. The results revealed that both total N-acetylglucosamine content, which constitutes chitin, and chitin synthase activities were increased. Whereas total glucose content, which constitutes β-1,3-glucan and α-1,3-glucan, was decreased; this decrease was attributed to a remarkable decrease in α-1,3-glucan. Additionally, the β-1,3-glucan in the alkali-insoluble fraction of the ΔkexB showed a high degree of polymerization. These results suggested that the loss of α-1,3-glucan in the ΔkexB was compensated by increases in the chitin content and the average degree of β-1,3-glucan polymerization.

  5. Stable isotope labeling confirms mixotrophic nature of streamer biofilm communities at alkaline hot springs

    Directory of Open Access Journals (Sweden)

    Florence eSchubotz

    2015-02-01

    Full Text Available Streamer biofilm communities (SBC are often observed within chemosynthetic zones of Yellowstone hot spring outflow channels, where temperatures exceed those conducive to photosynthesis. Nearest the hydrothermal source (75-88°C SBC comprise thermophilic Archaea and Bacteria, often mixed communities including Desulfurococcales and uncultured Crenarchaeota, as well as Aquificae, Thermus, each carrying diagnostic membrane lipid biomarkers. We tested the hypothesis that SBC can alternate their metabolism between autotrophy and heterotrophy depending on substrate availability. Feeding experiments were performed at two alkaline hot springs in Yellowstone National Park: Octopus Spring and ‘Bison Pool’, using various 13C-labeled substrates (bicarbonate, formate, acetate and glucose to determine the relative uptake of these different carbon sources. Highest 13C uptake, at both sites, was from acetate into almost all bacterial fatty acids, particularly into methyl-branched C15, C17 and C19 fatty acids that are diagnostic for Thermus/Meiothermus and some Firmicutes as well as into universally common C16:0 and C18:0 fatty acids. 13C-glucose showed a similar, but a 10 to 30 times lower uptake across most fatty acids. 13C bicarbonate uptake, signifying the presence of autotrophic communities was only significant at ‘Bison Pool’ and was observed predominantly in non-specific saturated C16, C18, C20 and C22 fatty acids. Incorporation of 13C-formate occurred only at very low rates at ‘Bison Pool’ and was almost undetectable at Octopus Spring, suggesting that formate is not an important carbon source for SBC. 13C uptake into archaeal lipids occurred predominantly with 13C acetate, suggesting also that archaeal communities at both springs have primarily heterotrophic carbon assimilation pathways. We hypothesize that these communities are energy-limited and predominantly nurtured by input of exogenous organic material, with only a small fraction being

  6. Isolation of a novel alkaline-stable lipase from a metagenomic library and its specific application for milkfat flavor production.

    Science.gov (United States)

    Peng, Qing; Wang, Xu; Shang, Meng; Huang, Jinjin; Guan, Guohua; Li, Ying; Shi, Bo

    2014-01-04

    Lipolytic enzymes are commonly used to produce desired flavors in lipolyzed milkfat (LMF) manufacturing processes. However, the choice of enzyme is critical because it determines the final profile of fatty acids released and the consequent flavor of the product. We previously constructed a metagenomic library from marine sediments, to explore the novel enzymes which have unique properties useful in flavor-enhancing LMF. A novel lipase Est_p6 was isolated from a metagenomic library and was expressed highly in E.coli. Bioinformatic analysis indicated that Est_p6 belongs to lipolytic enzyme family IV, the molecular weight of purified Est_p6 was estimated at 36 kDa by SDS-PAGE. The hydrolytic activity of the enzyme was stable under alkaline condition and the optimal temperature was 50°C. It had a high specific activity (2500 U/mg) toward pNP butyrate (pNP-C4), with K(m) and V(max) values of 1.148 mM and 3497 μmol∙min⁻¹∙mg⁻¹, respectively. The enzyme activity was enhanced by DTT and was not significantly inhibited by PMSF, EDTA or SDS. This enzyme also showed high hydrolysis specificity for myristate (C14) and palmitate (C16). It seems that Est_p6 has safety for commercial LMF flavor production and food manufacturing processes. The ocean is a vast and largely unexplored resource for enzymes. According the outstanding alkaline-stability of Est_p6 and it produced myristic acid and palmitic acid more efficiently than other free fatty acids in lipolyzed milkfat. This novel lipase may be used to impart a distinctive and desirable flavor and odor in milkfat flavor production.

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

    Science.gov (United States)

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

    2010-01-01

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

  8. Characterisation of a detergent-stable alkaline protease from a novel thermophilic strain Paenibacillus tezpurensis sp. nov. AS-S24-II.

    Science.gov (United States)

    Rai, Sudhir K; Roy, Jetendra K; Mukherjee, Ashis K

    2010-02-01

    An alkaline-protease-producing bacterial strain (AS-S24-II) isolated from a soil sample in Assam is a Gram-stain-positive, catalase-positive, endospore-forming rod and grows at temperatures ranging from 30 degrees C to 60 degrees C and salinity ranging from 0% to 7% (w/v) NaCl. Phenotypic characterisation, chemotaxonomic properties, presence of Paenibacillus-specific signature sequences, and ribotyping data suggested that the strain AS-S24-II represents a novel species of the genus Paenibacillus, for which the name Paenibacillus tezpurensis sp. nov. (MTCC 8959) is proposed. Phylogenetic analysis revealed that P. lentimorbus strain DNG-14 and P. lentimorbus strain DNG-16 represent the closest phylogenetic neighbour of this novel strain. Alkaline protease production (598 x 10(3) U l(-1)) by P. tezpurensis sp. nov. in SmF was optimised by response surface method. A laundry-detergent-stable, Ca(2+)-independent, 43-kDa molecular weight alkaline serine protease from this strain was purified with a 1.7-fold increase in specific activity. The purified protease displayed optimum activity at pH 9.5 and 45-50 degrees C temperature range and exhibited a significant stability and compatibility with surfactants and most of the tested commercial laundry detergents at room temperature. Further, the protease improved the wash performance of detergents, thus demonstrating its feasibility for inclusion in laundry detergent formulations.

  9. Engineered in situ bioremediation of a petroleum hydrocarbon-contaminated aquifer: assessment of mineralization based on alkalinity, inorganic carbon and stable carbon isotope balances

    Science.gov (United States)

    Hunkeler, Daniel; Höhener, Patrick; Bernasconi, Stefano; Zeyer, Josef

    1999-04-01

    A concept is proposed to assess in situ petroleum hydrocarbon mineralization by combining data on oxidant consumption, production of reduced species, CH 4, alkalinity and dissolved inorganic carbon (DIC) with measurements of stable isotope ratios. The concept was applied to a diesel fuel contaminated aquifer in Menziken, Switzerland, which was treated by engineered in situ bioremediation. In the contaminated aquifer, added oxidants (O 2 and NO 3-) were consumed, elevated concentrations of Fe(II), Mn(II), CH 4, alkalinity and DIC were detected and the DIC was generally depleted in 13C compared to the background. The DIC production was larger than expected based on the consumption of dissolved oxidants and the production of reduced species. Stable carbon isotope balances revealed that the DIC production in the aquifer originated mainly from microbial petroleum hydrocarbon mineralization, and that geochemical reactions such as carbonate dissolution produced little DIC. This suggests that petroleum hydrocarbon mineralization can be underestimated if it is determined based on concentrations of dissolved oxidants and reduced species.

  10. Direct Solar Charging of an Organic-Inorganic, Stable, and Aqueous Alkaline Redox Flow Battery with a Hematite Photoanode.

    Science.gov (United States)

    Wedege, Kristina; Azevedo, João; Khataee, Amirreza; Bentien, Anders; Mendes, Adélio

    2016-06-13

    The intermittent nature of the sunlight and its increasing contribution to electricity generation is fostering the energy storage research. Direct solar charging of an auspicious type of redox flow battery could make solar energy directly and efficiently dispatchable. The first solar aqueous alkaline redox flow battery using low cost and environmentally safe materials is demonstrated. The electrolytes consist of the redox couples ferrocyanide and anthraquinone-2,7-disulphonate in sodium hydroxide solution, yielding a standard cell potential of 0.74 V. Photovoltage enhancement strategies are demonstrated for the ferrocyanide-hematite junction by employing an annealing treatment and growing a layer of a conductive polyaniline polymer on the electrode surface, which decreases electron-hole recombination. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Bifunctional coating based on carboxymethyl chitosan with stable conjugated alkaline phosphatase for inhibiting bacterial adhesion and promoting osteogenic differentiation on titanium

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Dong; Neoh, Koon Gee, E-mail: chenkg@nus.edu.sg; Kang, En-Tang

    2016-01-01

    Graphical abstract: - Highlights: • Alkaline phosphatase was immobilized on carboxymethyl chitosan coating on Ti. • The coating is bifunctional; resists bacterial adhesion and enhances cell functions. • Osteogenic differentiation of osteoblasts and stem cells is enhanced on the coating. • The coating remains stable and functional after ethanol treatment and autoclaving. - Abstract: In this work, alkaline phosphatase (ALP) was covalently immobilized on carboxymethyl chitosan (CMCS)-coated polydopamine (PDA)-functionalized Ti to achieve a bifunctional surface. Our results showed ∼89% reduction in Staphylococcus epidermidis adhesion on this surface compared to that on pristine Ti. The ALP-modified Ti supported cell proliferation, and significantly enhanced cellular ALP activity and calcium deposition of osteoblasts, human mesenchymal stem cells (hMSCs) and human adipose-derived stem cells (hADSCs). The extent of enhancement in the functions of these cells is dependent on the surface density of immobilized ALP. The substrate prepared using an ALP solution of 50 μg/cm{sup 2} resulted in 44%, 54% and 129% increase in calcium deposited by osteoblasts, hMSCs and hADSCs, respectively, compared to those cultured on pristine Ti. The ALP-modified substrates also promoted the osteogenic differentiation of hMSCs and hADSCs by up-regulating gene expressions of runt-related transcription factor 2 (RUNX2), osterix (OSX), and osteocalcin (OC) in the two types of stem cells. The surface-immobilized ALP was stable after being subjected to 1 h immersion in 70% ethanol and autoclaving at 121 °C for 20 min. However, the enzymatic bioactivity of the surface-immobilized ALP was reduced by about 50% after these substrates were immersed in phosphate buffered saline (PBS) or PBS containing lysozyme for 14 days.

  12. Hydromagnesite precipitation in the Alkaline Lake Dujiali, central Qinghai-Tibetan Plateau: Constraints on hydromagnesite precipitation from hydrochemistry and stable isotopes

    International Nuclear Information System (INIS)

    Lin, Yongjie; Zheng, Mianping; Ye, Chuanyong

    2017-01-01

    The mineral hydromagnesite, Mg 5 (CO 3 ) 4 (OH) 2 ·4H 2 O, is a common form of hydrated Mg-carbonate in alkaline lakes, yet the processes involved in its formation are not well understood. This study focuses on Dujiali Lake, in the central Qinghai-Tibetan Plateau (QTP), which is one of the few environments on the earth's surface with extensive Holocene precipitation of hydromagnesite. The hydrogeochemistry of surface waters, and the mineralogical, stable isotope (δ 13 C and δ 18 O), and radiogenic isotope content of hydromagnesite deposits were analyzed to investigate formation mechanisms. The chemical composition of surface water around Dujiali Lake evolved from the rock-weathering-type waters of T1 (Ca−Mg−HCO 3 water type) to more concentrated sodic waters of T2 (Na−SO 4 −Cl water type) due to evaporation. XRD results show that the mineralogical composition of samples is pure hydromagnesite. Analysis of oxygen isotopes in the hydromagnesite indicates that supergene formation with authigenic carbonate crystallization from evaporation water is the dominant precipitation process. Combined carbon-oxygen isotope analysis suggests atmospheric CO 2 provided a carbon source for the precipitation of hydromagnesite. These findings suggest that hydromagnesite precipitation at Lake Dujiali is mainly inorganic in nature, and the greenhouse gas, CO 2 , is trapped and stored in the hydromagnesite directly from the atmosphere. AMS radiocarbon dating of samples indicates CO 2 was sequestered between 5845 ± 30 to 6090 ± 25 cal a BP in the Dujiali Lake hydromagnesite deposit. The study contributes to improved understanding of hydromagnesite formation in modern and ancient playas. - Highlights: • The stable isotopes, radiogenic isotope data are firstly obtained from the hydromagnesite deposits of Lake Dujiali in QTP. • Hydromagnesite precipitation at Lake Dujiali is mainly inorganic. • δ 18 O indicates supergene formation with authigenic carbonate

  13. A novel nonionic surfactant- and solvent-stable alkaline serine protease from Serratia sp. SYBC H with duckweed as nitrogen source: production, purification, characteristics and application.

    Science.gov (United States)

    Li, G Y; Cai, Y J; Liao, X R; Yin, J

    2011-07-01

    A novel nonionic surfactant- and hydrophilic solvent-stable alkaline serine protease was purified from the culture supernatant of Serratia sp. SYBC H with duckweed as nitrogen source. The molecular mass of the purified protease is about 59 kDa as assayed via SDS-PAGE. The protease is highly active over the pH range between 5.0 and 11.0, with the maximum activity at pH 8.0. It is also fairly active over the temperature range between 30 and 80°C, with the maximum activity at 40°C. The protease activity was substantially stimulated by Mn(2+) and Na(+) (5 mM), up to 837.9 and 134.5% at 40°C, respectively. In addition, Mn(2+) enhanced the thermostability of the protease significantly at 60°C. Over 90% of its initial activity remained even after incubating for 60 min at 40°C in 50% (v/v) hydrophilic organic solvents such as DMF, DMSO, acetone and MeOH. The protease retained 81.7, 83.6 and 76.2% of its initial activity in the presence of nonionic surfactants 20% (v/v) Tween 80, 25% (v/v) glycerol and Triton X-100, respectively. The protease is strongly inhibited by PMSF, suggesting that it is a serine protease. Washing experiments revealed that the protease has an excellent ability to remove blood stains.

  14. Application of alkaline thermo-stable lipase(s) enzyme produced from irradiated microbial isolate in the field of detergent technology

    International Nuclear Information System (INIS)

    Ahmed, O.E.A.M.S

    2010-01-01

    (s) from Bacillus brevis B 2 was studied. It was found that:1-The optimum incubation temperature for maximum lipase(s) formation is 70 degree C after 24h at ph 11.5.2- Maximum lipase(s) biosynthesis attained at concentration of 1% for each of fish-wastes and yeast extract with inoculum size equal 2 ml/100 ml culture medium incubating under shaking condition.3-Using fish-wastes-yeast extract medium fortified with disaccharide (sucrose or maltose or lactose) was the best nutritional medium for lipase formation. On contrary none of the tested nitrogen sources affect the induction of the enzyme.4-The addition of some surfactant to the nutritional medium revealed that Tween-20 slightly increase lipase(s) synthesis while the presence of zinc sulfate (100 ppm) and folic acid (500 ppm) enhanced the formation of lipase(s) by B. brevis B 2 . 5-Exposure of the experimental organism to 1 KGy gamma-irradiation resulted in slight increase in the level of enzyme. Thermoalkalo-stable lipase(s) from B. brevis B 2 was purified 21.8-fold using ammonium sulphate precipitation (100% saturation) followed by fractionation on Sephadex G-200 column chromatography. The properties of the enzyme were studied.Maximal enzyme activity occurred at 80 degree C. In addition, exposure of the enzyme to 70-80 degree C for 1h resulted remaining activities equal 98-90% respectively, indicating that it was thermo-stable. Optimum ph for maximal enzyme activity was ph 9.5 and exposure of the enzyme to alkaline condition (ph 9 - 10.5) for 1h resulted remaining activity from 80-90%, indicating the alkalo-stable nature of the enzyme. - The relationship between enzyme activity and enzyme concentration indicated that the extent of catalytic action was a function of the concentration of the enzyme. Maximal enzyme activity obtained after 60 minute and the reaction rate increased as a result of increasing substrate concentration, up to 1.2 mg of p-nitrophenyl palmitate, with some saturation at the highest concentration

  15. 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

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. Stable isotopes

    International Nuclear Information System (INIS)

    Evans, D.K.

    1986-01-01

    Seventy-five percent of the world's stable isotope supply comes from one producer, Oak Ridge Nuclear Laboratory (ORNL) in the US. Canadian concern is that foreign needs will be met only after domestic needs, thus creating a shortage of stable isotopes in Canada. This article describes the present situation in Canada (availability and cost) of stable isotopes, the isotope enrichment techniques, and related research programs at Chalk River Nuclear Laboratories (CRNL)

  2. 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...

  3. 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.

  4. 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.

  5. 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.)

  6. Unpredictably Stable

    DEFF Research Database (Denmark)

    Failla, Virgilio; Melillo, Francesca; Reichstein, Toke

    2014-01-01

    Is entrepreneurship a more stable career choice for high employment turnover individuals? We find that a transition to entrepreneurship induces a shift towards stayer behavior and identify job matching, job satisfaction and lock-in effects as main drivers. These findings have major implications...

  7. Stable particles

    International Nuclear Information System (INIS)

    Samios, N.P.

    1993-01-01

    I have been asked to review the subject of stable particles, essentially the particles that eventually comprised the meson and baryon octets. with a few more additions -- with an emphasis on the contributions made by experiments utilizing the bubble chamber technique. In this activity, much work had been done by the photographic emulsion technique and cloud chambers-exposed to cosmic rays as well as accelerator based beams. In fact, many if not most of the stable particles were found by these latter two techniques, however, the forte of the bubble chamber (coupled with the newer and more powerful accelerators) was to verify, and reinforce with large statistics, the existence of these states, to find some of the more difficult ones, mainly neutrals and further to elucidate their properties, i.e., spin, parity, lifetimes, decay parameters, etc

  8. 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.

  9. Stable isotopes

    International Nuclear Information System (INIS)

    Brazier, J.L.; Guinamant, J.L.

    1995-01-01

    According to the progress which has been realised in the technology of separating and measuring isotopes, the stable isotopes are used as preferable 'labelling elements' for big number of applications. The isotopic composition of natural products shows significant variations as a result of different reasons like the climate, the seasons, or their geographic origins. So, it was proved that the same product has a different isotopic composition of alimentary and agriculture products. It is also important in detecting the pharmacological and medical chemicals. This review article deals with the technology, like chromatography and spectrophotometry, adapted to this aim, and some important applications. 17 refs. 6 figs

  10. Stable Tetraquarks

    Energy Technology Data Exchange (ETDEWEB)

    Quigg, Chris [Fermilab

    2018-04-13

    For very heavy quarks, relations derived from heavy-quark symmetry imply novel narrow doubly heavy tetraquark states containing two heavy quarks and two light antiquarks. We predict that double-beauty states will be stable against strong decays, whereas the double-charm states and mixed beauty+charm states will dissociate into pairs of heavy-light mesons. Observing a new double-beauty state through its weak decays would establish the existence of tetraquarks and illuminate the role of heavy color-antitriplet diquarks as hadron constituents.

  11. Stable beams

    CERN Multimedia

    2015-01-01

    Stable beams: two simple words that carry so much meaning at CERN. When LHC page one switched from "squeeze" to "stable beams" at 10.40 a.m. on Wednesday, 3 June, it triggered scenes of jubilation in control rooms around the CERN sites, as the LHC experiments started to record physics data for the first time in 27 months. This is what CERN is here for, and it’s great to be back in business after such a long period of preparation for the next stage in the LHC adventure.   I’ve said it before, but I’ll say it again. This was a great achievement, and testimony to the hard and dedicated work of so many people in the global CERN community. I could start to list the teams that have contributed, but that would be a mistake. Instead, I’d simply like to say that an achievement as impressive as running the LHC – a machine of superlatives in every respect – takes the combined effort and enthusiasm of everyone ...

  12. Distribution of radiocesium and stable elements within a pine tree

    International Nuclear Information System (INIS)

    Yoshida, S.; Watanabe, M.; Suzuki, A.

    2011-01-01

    Distributions of 137 Cs and stable elements in different parts of a pine tree collected in Chernobyl-contaminated area in Belarus were determined. Samples include annual tree rings of wood, branches and needles with different ages. The concentrations of 137 Cs and stable Cs in annual tree rings were the highest in cambium and decreased sharply towards inside. The youngest needles and branches contained higher 137 Cs and stable Cs than older ones. The concentration of 137 Cs being highest in growing parts suggests the highest radiation dose to the radiation-sensitive parts of tree. Distribution patterns of stable elements in pine tree differ among the elements. Distributions similar to those of Cs were observed for K and Rb, suggesting that alkaline metals tend to be translocated to young growing parts of pine tree. A similar distribution was also observed for phosphorus. Distributions of alkaline earth metals and several heavy metals were different from those of alkaline metals. (authors)

  13. 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

  14. 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

    2004-10-01

    Gelation technologies have been developed to provide more efficient vertical sweep efficiencies for flooding naturally fractured oil reservoirs or more efficient areal sweep efficiency for those with high permeability contrast ''thief zones''. The field proven alkaline-surfactant-polymer technology economically recovers 15% to 25% OOIP more oil than waterflooding from swept pore space of an oil reservoir. However, alkaline-surfactant-polymer technology is not amenable to naturally fractured reservoirs or those with thief zones because much of injected solution bypasses target pore space containing oil. This work investigates whether combining these two technologies could broaden applicability of alkaline-surfactant-polymer flooding into these reservoirs. A prior fluid-fluid report discussed interaction of different gel chemical compositions and alkaline-surfactant-polymer solutions. Gel solutions under dynamic conditions of linear corefloods showed similar stability to alkaline-surfactant-polymer solutions as in the fluid-fluid analyses. Aluminum-polyacrylamide, flowing gels are not stable to alkaline-surfactant-polymer solutions of either pH 10.5 or 12.9. Chromium acetate-polyacrylamide flowing and rigid flowing gels are stable to subsequent alkaline-surfactant-polymer solution injection. Rigid flowing chromium acetate-polyacrylamide gels maintained permeability reduction better than flowing chromium acetate-polyacrylamide gels. Silicate-polyacrylamide gels are not stable with subsequent injection of either a pH 10.5 or a 12.9 alkaline-surfactant-polymer solution. Neither aluminum citrate-polyacrylamide nor silicate-polyacrylamide gel systems produced significant incremental oil in linear corefloods. Both flowing and rigid flowing chromium acetate-polyacrylamide gels produced incremental oil with the rigid flowing gel producing the greatest amount. Higher oil recovery could have been due to higher differential pressures across cores. None of

  15. 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

    Gelation technologies have been developed to provide more efficient vertical sweep efficiencies for flooding naturally fractured oil reservoirs or reservoirs with different sand lenses with high permeability contrast. The field proven alkaline-surfactant-polymer technology economically recovers 15% to 25% OOIP more crude oil than waterflooding from swept pore space of an oil reservoir. However, alkaline-surfactant-polymer technology is not amenable to naturally fractured reservoirs or reservoirs with high permeability contrast zones because much of injected solution bypasses target pore space containing oil. This work investigates whether combining these two technologies could broaden applicability of alkaline-surfactant-polymer flooding into these reservoirs. 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 ranging from 9.2 to 12.9. Gel solutions under dynamic conditions of linear corefloods showed similar stability to alkaline-surfactant-polymer solutions as in

  16. 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.

  17. 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

  18. 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.

  19. 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-.

  20. 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.

  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

    Gelation technologies have been developed to provide more efficient vertical sweep efficiencies for flooding naturally fractured oil reservoirs or reservoirs with different sand lenses with high permeability contrast. The field proven alkaline-surfactant-polymer technology economically recovers 15% to 25% OOIP more crude oil than waterflooding froin swept pore space of an oil reservoir. However, alkaline-surfactant-polymer technology is not amenable to naturally fractured reservoirs or reservoirs with high permeability contrast zones because much of injected solution bypasses target pore space containing oil. This work investigates whether combining these two technologies could broaden applicability of alkaline-surfactant-polymer flooding into these reservoirs. 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 ranging from 9.2 to 12.9. Gel solutions under dynamic conditions of linear corefloods showed similar stability to alkaline-surfactant-polymer solutions as in

  2. 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.

  3. Cementitious porous pavement in stormwater quality control: pH and alkalinity elevation.

    Science.gov (United States)

    Kuang, Xuheng; Sansalone, John

    2011-01-01

    A certain level of alkalinity acts as a buffer and maintains the pH value in a stable range in water bodies. With rapid urban development, more and more acidic pollutants flow to watersheds with runoff and drop alkalinity to a very low level and ultimately degrade the water environment. Cementitious porous pavement is an effective tool for stormwater acidic neutralization. When stormwater infiltrates cement porous pavement (CPP) materials, alkalinity and pH will be elevated due to the basic characteristics of cement concrete. The elevated alkalinity will neutralize acids in water bodies and maintain the pH in a stable level as a buffer. It is expected that CPP materials still have a certain capability of alkalinity elevation after years of service, which is important for CPP as an effective tool for stormwater management. However, few previous studies have reported on how CPP structures would elevate runoff alkalinity and pH after being exposed to rainfall-runoff for years. In this study, three groups of CPP specimens, all exposed to rainfall-runoff for 3 years, were used to test the pH and alkalinity elevation properties. It was found that runoff pH values were elevated from 7.4 to the range of 7.8-8.6 after infiltrating through the uncoated specimens, and from 7.4 to 8.5-10.7 after infiltrating through aluminum-coated specimens. Runoff alkalinity elevation efficiencies are 11.5-14.5% for uncoated specimens and 42.2% for coated specimens. The study shows that CPP is an effective passive unit operation for stormwater acid neutralization in our built environment.

  4. 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.

  5. Stable Isotope Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Tissue samples (skin, bone, blood, muscle) are analyzed for stable carbon, stable nitrogen, and stable sulfur analysis. Many samples are used in their entirety for...

  6. 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)

  7. 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.

  8. 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}.

  9. 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

  10. 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)

  11. 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.

  12. 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), ...

  13. Hydroxide Self-Feeding High-Temperature Alkaline Direct Formate Fuel Cells.

    Science.gov (United States)

    Li, Yinshi; Sun, Xianda; Feng, Ying

    2017-05-22

    Conventionally, both the thermal degradation of the anion-exchange membrane and the requirement of additional hydroxide for fuel oxidation reaction hinder the development of the high-temperature alkaline direct liquid fuel cells. The present work addresses these two issues by reporting a polybenzimidazole-membrane-based direct formate fuel cell (DFFC). Theoretically, the cell voltage of the high-temperature alkaline DFFC can be as high as 1.45 V at 90 °C. It has been demonstrated that a proof-of-concept alkaline DFFC without adding additional hydroxide yields a peak power density of 20.9 mW cm -2 , an order of magnitude higher than both alkaline direct ethanol fuel cells and alkaline direct methanol fuel cells, mainly because the hydrolysis of formate provides enough OH - ions for formate oxidation reaction. It was also found that this hydroxide self-feeding high-temperature alkaline DFFC shows a stable 100 min constant-current discharge at 90 °C, proving the conceptual feasibility. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. 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.

  15. Stable convergence and stable limit theorems

    CERN Document Server

    Häusler, Erich

    2015-01-01

    The authors present a concise but complete exposition of the mathematical theory of stable convergence and give various applications in different areas of probability theory and mathematical statistics to illustrate the usefulness of this concept. Stable convergence holds in many limit theorems of probability theory and statistics – such as the classical central limit theorem – which are usually formulated in terms of convergence in distribution. Originated by Alfred Rényi, the notion of stable convergence is stronger than the classical weak convergence of probability measures. A variety of methods is described which can be used to establish this stronger stable convergence in many limit theorems which were originally formulated only in terms of weak convergence. Naturally, these stronger limit theorems have new and stronger consequences which should not be missed by neglecting the notion of stable convergence. The presentation will be accessible to researchers and advanced students at the master's level...

  16. 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.)

  17. 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.

  18. 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.

  19. stableGP

    Data.gov (United States)

    National Aeronautics and Space Administration — The code in the stableGP package implements Gaussian process calculations using efficient and numerically stable algorithms. Description of the algorithms is in the...

  20. Angina Pectoris (Stable Angina)

    Science.gov (United States)

    ... Peripheral Artery Disease Venous Thromboembolism Aortic Aneurysm More Angina Pectoris (Stable Angina) Updated:Aug 21,2017 You may have heard the term “angina pectoris” or “stable angina” in your doctor’s office, ...

  1. Eichrom's ABEC trademark resins: Alkaline radioactive waste treatment, radiopharmaceutical, and potential hydrometallurgical applications

    International Nuclear Information System (INIS)

    Bond, A.H.; Gula, M.J.; Chang, F.; Rogers, R.D.

    1997-01-01

    Eichrom's ABEC trademark resins selectivity extract certain anions from high ionic strength acidic, neutral, or strongly alkaline media, and solute stripping can be accomplished by eluting with water. ABEC resins are stable to pH extreme and radiolysis and operate in high ionic strength and/or alkaline solutions where anion-exchange is often ineffective. Potential applications of the ABEC materials include heavy metal and ReO 4 - separations in hydrometallurgy and purification of perrhenate iodide, and iodate in radiopharmaceutical production. Separation of 99m TcO 4 - from its 99 MoO 4 2- parent and stripping with water or physiological saline solution have been demonstrated for radiopharmaceutical applications. Removal of 99 TcO 4 - and 129 I - from alkaline tank wastes has also been successfully demonstrated. The authors will discuss the scale-up studies, process-scale testing, and market development of this new extraction material

  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. 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.

  6. The characterization of soybean oil body integral oleosin isoforms and the effects of alkaline pH on them.

    Science.gov (United States)

    Cao, Yanyun; Zhao, Luping; Ying, Yusang; Kong, Xiangzhen; Hua, Yufei; Chen, Yeming

    2015-06-15

    Oil body, an organelle in seed cell (naturally pre-emulsified oil), has great potentials to be used in food, cosmetics, pharmaceutical and other applications requiring stable oil-in-water emulsions. Researchers have tried to extract oil body by alkaline buffers, which are beneficial for removing contaminated proteins. But it is not clear whether alkaline buffers could remove oil body integral proteins (mainly oleosins), which could keep oil body integrity and stability. In this study, seven oleosin isoforms were identified for soybean oil body (three isoforms, 24 kDa; three isoforms, 18 kDa; one isoform, 16kDa). Oleosins were not glycoproteins and 24 kDa oleosin isoforms possessed less thiol groups than 18 kDa ones. It was found that alkaline pH not only removed contaminated proteins but also oleosins, and more and more oleosins were removed with increasing alkaline pH. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. 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....

  8. Stable Boundary Layer Issues

    OpenAIRE

    Steeneveld, G.J.

    2012-01-01

    Understanding and prediction of the stable atmospheric boundary layer is a challenging task. Many physical processes are relevant in the stable boundary layer, i.e. turbulence, radiation, land surface coupling, orographic turbulent and gravity wave drag, and land surface heterogeneity. The development of robust stable boundary layer parameterizations for use in NWP and climate models is hampered by the multiplicity of processes and their unknown interactions. As a result, these models suffer ...

  9. 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

  10. Stable isotopes labelled compounds

    International Nuclear Information System (INIS)

    1982-09-01

    The catalogue on stable isotopes labelled compounds offers deuterium, nitrogen-15, and multiply labelled compounds. It includes: (1) conditions of sale and delivery, (2) the application of stable isotopes, (3) technical information, (4) product specifications, and (5) the complete delivery programme

  11. Evolutionary Stable Strategy

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 21; Issue 9. Evolutionary Stable Strategy: Application of Nash Equilibrium in Biology. General Article Volume 21 Issue 9 September 2016 pp 803- ... Keywords. Evolutionary game theory, evolutionary stable state, conflict, cooperation, biological games.

  12. Stable Boundary Layer Issues

    NARCIS (Netherlands)

    Steeneveld, G.J.

    2012-01-01

    Understanding and prediction of the stable atmospheric boundary layer is a challenging task. Many physical processes are relevant in the stable boundary layer, i.e. turbulence, radiation, land surface coupling, orographic turbulent and gravity wave drag, and land surface heterogeneity. The

  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. 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...

  20. 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.

  1. 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

  2. Normal modified stable processes

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole Eiler; Shephard, N.

    2002-01-01

    Gaussian (NGIG) laws. The wider framework thus established provides, in particular, for added flexibility in the modelling of the dynamics of financial time series, of importance especially as regards OU based stochastic volatility models for equities. In the special case of the tempered stable OU process......This paper discusses two classes of distributions, and stochastic processes derived from them: modified stable (MS) laws and normal modified stable (NMS) laws. This extends corresponding results for the generalised inverse Gaussian (GIG) and generalised hyperbolic (GH) or normal generalised inverse...

  3. Applications of stable isotopes

    International Nuclear Information System (INIS)

    Letolle, R.; Mariotti, A.; Bariac, T.

    1991-06-01

    This report reviews the historical background and the properties of stable isotopes, the methods used for their measurement (mass spectrometry and others), the present technics for isotope enrichment and separation, and at last the various present and foreseeable application (in nuclear energy, physical and chemical research, materials industry and research; tracing in industrial, medical and agronomical tests; the use of natural isotope variations for environmental studies, agronomy, natural resources appraising: water, minerals, energy). Some new possibilities in the use of stable isotope are offered. A last chapter gives the present state and forecast development of stable isotope uses in France and Europe

  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. Analysing Stable Time Series

    National Research Council Canada - National Science Library

    Adler, Robert

    1997-01-01

    We describe how to take a stable, ARMA, time series through the various stages of model identification, parameter estimation, and diagnostic checking, and accompany the discussion with a goodly number...

  10. 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 ...

  11. 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 ...

  12. 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.

  13. Mineral Carbonation Potential of CO2 from Natural and Industrial-based Alkalinity Sources

    Science.gov (United States)

    Wilcox, J.; Kirchofer, A.

    2014-12-01

    Mineral carbonation is a Carbon Capture and Storage (CSS) technology where gaseous CO2 is reacted with alkaline materials (such as silicate minerals and alkaline industrial wastes) and converted into stable and environmentally benign carbonate minerals (Metz et al., 2005). Here, we present a holistic, transparent life cycle assessment model of aqueous mineral carbonation built using a hybrid process model and economic input-output life cycle assessment approach. We compared the energy efficiency and the net CO2 storage potential of various mineral carbonation processes based on different feedstock material and process schemes on a consistent basis by determining the energy and material balance of each implementation (Kirchofer et al., 2011). In particular, we evaluated the net CO2 storage potential of aqueous mineral carbonation for serpentine, olivine, cement kiln dust, fly ash, and steel slag across a range of reaction conditions and process parameters. A preliminary systematic investigation of the tradeoffs inherent in mineral carbonation processes was conducted and guidelines for the optimization of the life-cycle energy efficiency are provided. The life-cycle assessment of aqueous mineral carbonation suggests that a variety of alkalinity sources and process configurations are capable of net CO2 reductions. The maximum carbonation efficiency, defined as mass percent of CO2 mitigated per CO2 input, was 83% for CKD at ambient temperature and pressure conditions. In order of decreasing efficiency, the maximum carbonation efficiencies for the other alkalinity sources investigated were: olivine, 66%; SS, 64%; FA, 36%; and serpentine, 13%. For natural alkalinity sources, availability is estimated based on U.S. production rates of a) lime (18 Mt/yr) or b) sand and gravel (760 Mt/yr) (USGS, 2011). The low estimate assumes the maximum sequestration efficiency of the alkalinity source obtained in the current work and the high estimate assumes a sequestration efficiency

  14. 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

  15. Uses of stable isotopes

    International Nuclear Information System (INIS)

    Axente, Damian

    1998-01-01

    The most important fields of stable isotope use with examples are presented. These are: 1. Isotope dilution analysis: trace analysis, measurements of volumes and masses; 2. Stable isotopes as tracers: transport phenomena, environmental studies, agricultural research, authentication of products and objects, archaeometry, studies of reaction mechanisms, structure and function determination of complex biological entities, studies of metabolism, breath test for diagnostic; 3. Isotope equilibrium effects: measurement of equilibrium effects, investigation of equilibrium conditions, mechanism of drug action, study of natural processes, water cycle, temperature measurements; 4. Stable isotope for advanced nuclear reactors: uranium nitride with 15 N as nuclear fuel, 157 Gd for reactor control. In spite of some difficulties of stable isotope use, particularly related to the analytical techniques, which are slow and expensive, the number of papers reporting on this subject is steadily growing as well as the number of scientific meetings organized by International Isotope Section and IAEA, Gordon Conferences, and regional meeting in Germany, France, etc. Stable isotope application development on large scale is determined by improving their production technologies as well as those of labeled compound and the analytical techniques. (author)

  16. Calcium stable isotope geochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Gausonne, Nikolaus [Muenster Univ. (Germany). Inst. fuer Mineralogie; Schmitt, Anne-Desiree [Strasbourg Univ. (France). LHyGeS/EOST; Heuser, Alexander [Bonn Univ. (Germany). Steinmann-Inst. fuer Geologie, Mineralogie und Palaeontologie; Wombacher, Frank [Koeln Univ. (Germany). Inst. fuer Geologie und Mineralogie; Dietzel, Martin [Technische Univ. Graz (Austria). Inst. fuer Angewandte Geowissenschaften; Tipper, Edward [Cambridge Univ. (United Kingdom). Dept. of Earth Sciences; Schiller, Martin [Copenhagen Univ. (Denmark). Natural History Museum of Denmark

    2016-08-01

    This book provides an overview of the fundamentals and reference values for Ca stable isotope research, as well as current analytical methodologies including detailed instructions for sample preparation and isotope analysis. As such, it introduces readers to the different fields of application, including low-temperature mineral precipitation and biomineralisation, Earth surface processes and global cycling, high-temperature processes and cosmochemistry, and lastly human studies and biomedical applications. The current state of the art in these major areas is discussed, and open questions and possible future directions are identified. In terms of its depth and coverage, the current work extends and complements the previous reviews of Ca stable isotope geochemistry, addressing the needs of graduate students and advanced researchers who want to familiarize themselves with Ca stable isotope research.

  17. Calcium stable isotope geochemistry

    International Nuclear Information System (INIS)

    Gausonne, Nikolaus; Schmitt, Anne-Desiree; Heuser, Alexander; Wombacher, Frank; Dietzel, Martin; Tipper, Edward; Schiller, Martin

    2016-01-01

    This book provides an overview of the fundamentals and reference values for Ca stable isotope research, as well as current analytical methodologies including detailed instructions for sample preparation and isotope analysis. As such, it introduces readers to the different fields of application, including low-temperature mineral precipitation and biomineralisation, Earth surface processes and global cycling, high-temperature processes and cosmochemistry, and lastly human studies and biomedical applications. The current state of the art in these major areas is discussed, and open questions and possible future directions are identified. In terms of its depth and coverage, the current work extends and complements the previous reviews of Ca stable isotope geochemistry, addressing the needs of graduate students and advanced researchers who want to familiarize themselves with Ca stable isotope research.

  18. 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.

  19. 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.

  20. Development of durable and efficient electrodes for large-scale alkaline water electrolysis

    DEFF Research Database (Denmark)

    Kjartansdóttir, Cecilia Kristin; Nielsen, Lars Pleth; Møller, Per

    2013-01-01

    A new type of electrodes for alkaline water electrolysis is produced by physical vapour depositing (PVD) of aluminium onto a nickel substrate. The PVD Al/Ni is heat-treated to facilitate alloy formation followed by a selective aluminium alkaline leaching. The obtained porous Ni surface is uniform...... and characterized by a unique interlayer adhesion, which is critical for industrial application. IR-compensated polarisation curves prepared in a half-cell setup with 1 M KOH electrolyte at room temperature reveals that at least 400 mV less potential is needed to decompose water into hydrogen and oxygen...... produced bipolar electrolyser stack. The developed electrodes showed stable behaviour under intermittent operation for over 9000 h indicating no serious deactivation in the density of active sites....

  1. 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

  2. Combined strategies for improving production of a thermo-alkali stable laccase in Pichia pastoris

    Directory of Open Access Journals (Sweden)

    Jiayi Wang

    2017-07-01

    Conclusions: The productivity of the thermo-alkali stable laccase from B. licheniformis expressed in P. pastoris was significantly improved through the combination of site-directed mutagenesis and optimization of the cultivation process. The mutant enzyme retains good stability under high temperature and alkaline conditions, and is a good candidate for industrial application in dye decolorization.

  3. Stable isotope studies

    International Nuclear Information System (INIS)

    Ishida, T.

    1992-01-01

    The research has been in four general areas: (1) correlation of isotope effects with molecular forces and molecular structures, (2) correlation of zero-point energy and its isotope effects with molecular structure and molecular forces, (3) vapor pressure isotope effects, and (4) fractionation of stable isotopes. 73 refs, 38 figs, 29 tabs

  4. Interactive Stable Ray Tracing

    DEFF Research Database (Denmark)

    Dal Corso, Alessandro; Salvi, Marco; Kolb, Craig

    2017-01-01

    Interactive ray tracing applications running on commodity hardware can suffer from objectionable temporal artifacts due to a low sample count. We introduce stable ray tracing, a technique that improves temporal stability without the over-blurring and ghosting artifacts typical of temporal post-pr...

  5. The Stable Concordance Genus

    OpenAIRE

    Kearney, M. Kate

    2013-01-01

    The concordance genus of a knot is the least genus of any knot in its concordance class. Although difficult to compute, it is a useful invariant that highlights the distinction between the three-genus and four-genus. In this paper we define and discuss the stable concordance genus of a knot, which describes the behavior of the concordance genus under connected sum.

  6. Stable radiographic scanning agents

    International Nuclear Information System (INIS)

    1976-01-01

    Stable compositions which are useful in the preparation of Technetium-99m-based scintigraphic agents are discussed. They are comprised of ascorbic acid or a pharmaceutically acceptable salt or ester thereof in combination with a pertechnetate reducing agent or dissolved in oxidized pertechnetate-99m (sup(99m)TcO 4 - ) solution

  7. Some stable hydromagnetic equilibria

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, J L; Oberman, C R; Kulsrud, R M; Frieman, E A [Project Matterhorn, Princeton University, Princeton, NJ (United States)

    1958-07-01

    We have been able to find and investigate the properties of equilibria which are hydromagnetically stable. These equilibria can be obtained, for example, by wrapping conductors helically around the stellarator tube. Systems with I = 3 or 4 are indicated to be optimum for stability purposes. In some cases an admixture of I = 2 fields can be advantageous for achieving equilibrium. (author)

  8. 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.

  9. 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.

  10. 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.

  11. Stable isotope analysis

    International Nuclear Information System (INIS)

    Tibari, Elghali; Taous, Fouad; Marah, Hamid

    2014-01-01

    This report presents results related to stable isotopes analysis carried out at the CNESTEN DASTE in Rabat (Morocco), on behalf of Senegal. These analyzes cover 127 samples. These results demonstrate that Oxygen-18 and Deuterium in water analysis were performed by infrared Laser spectroscopy using a LGR / DLT-100 with Autosampler. Also, the results are expressed in δ values (‰) relative to V-SMOW to ± 0.3 ‰ for oxygen-18 and ± 1 ‰ for deuterium.

  12. Forensic Stable Isotope Biogeochemistry

    Science.gov (United States)

    Cerling, Thure E.; Barnette, Janet E.; Bowen, Gabriel J.; Chesson, Lesley A.; Ehleringer, James R.; Remien, Christopher H.; Shea, Patrick; Tipple, Brett J.; West, Jason B.

    2016-06-01

    Stable isotopes are being used for forensic science studies, with applications to both natural and manufactured products. In this review we discuss how scientific evidence can be used in the legal context and where the scientific progress of hypothesis revisions can be in tension with the legal expectations of widely used methods for measurements. Although this review is written in the context of US law, many of the considerations of scientific reproducibility and acceptance of relevant scientific data span other legal systems that might apply different legal principles and therefore reach different conclusions. Stable isotopes are used in legal situations for comparing samples for authenticity or evidentiary considerations, in understanding trade patterns of illegal materials, and in understanding the origins of unknown decedents. Isotope evidence is particularly useful when considered in the broad framework of physiochemical processes and in recognizing regional to global patterns found in many materials, including foods and food products, drugs, and humans. Stable isotopes considered in the larger spatial context add an important dimension to forensic science.

  13. 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

  14. 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...

  15. 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.

  16. 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...

  17. 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

  18. 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

  19. Dansyl - Substituted Aza Crown Ethers: Complexation with Alkali, Alkaline Earth Metal Ions and Ammonium

    Science.gov (United States)

    Deiab, Shihab; Archibong, Edikan; Tasheva, Donka; Mochona, Bereket; Gangapuram, Madhavi; Redda, Kinfe

    2011-01-01

    The present study investigates the binding properties of four dansyl substituted aza-crown ethers with alkali, alkaline earth metal ions and ammonium. The influence of the solvent polarity and protonation on the photophysical properties of the compounds was studied by UV/Vis and fluorescence methods. The host species caused only slight changes on the absorption spectra of the ligands. The fluorescence changes were more pronounced and concentration dependent thus allowing to calculate the binding constants of the process. The most stable complex under our working conditions was the one between Ba2+ and DNS18C6. PMID:21738561

  20. Effect of alkaline earth metal and magnesium cations on cadmium extraction from chloride solutions by tributyl phosphate

    International Nuclear Information System (INIS)

    Prokuev, V.A.; Belousov, E.A.

    1985-01-01

    At 298 K thermodynamic constants of cadmium (2) extraction from chloride solutions of magnesium, calcium, strontium and barium by tributyl phosphate are calculated. It is established, that logarithm of the thermodynamic extraction constant is in a linear dependence from the change in the cation hydration enthalpy in agqueous solution. It is shown, that activity coefficient of neutral complex CdVCl 2 differs from one, and it is the higher the more stable the complex is in alkaline earth metal chloride solutions

  1. 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

  2. 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.

  3. 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.

  4. 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...

  5. 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

  6. 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.

  7. 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.

  8. Diversity and activity of methanotrophs in alkaline soil from a Chinese coal mine.

    Science.gov (United States)

    Han, Bing; Chen, Yin; Abell, Guy; Jiang, Hao; Bodrossy, Levente; Zhao, Jiangang; Murrell, J Colin; Xing, Xin-Hui

    2009-11-01

    Culture-independent molecular biological techniques, including 16S rRNA gene and functional gene clone libraries and microarray analyses using pmoA (encoding a key subunit of particulate methane monooxygenase), were applied to investigate the methanotroph community structure in alkaline soil from a Chinese coal mine. This environment contained a high diversity of methanotrophs, including the type II methanotrophs Methylosinus/Methylocystis, type I methanotrophs related to Methylobacter/Methylosoma and Methylococcus, and a number of as yet uncultivated methanotrophs. In order to identify the metabolically active methane-oxidizing bacteria from this alkaline environment, DNA stable isotope probing (DNA-SIP) experiments using (13)CH(4) were carried out. This showed that both type I and type II methanotrophs were active, together with methanotrophs related to Methylocella, which had previously been found only in acidic environments. Methylotrophs, including Methylopila and Hyphomicrobium, were also detected in soil DNA and after DNA-SIP experiments. DNA sequence information on the most abundant, active methanotrophs in this alkaline soil will facilitate the design of oligonucleotide probes to monitor enrichment cultures when isolating key alkaliphilic methanotrophs from such environments.

  9. Diversity and activity of methanotrophs in alkaline soil from a Chinese coal mine

    Energy Technology Data Exchange (ETDEWEB)

    Han, Bing; Chen, Yin; Abell, Guy; Jiang, Hao; Bodrossy, Levente; Zhao, Jiangang; Murrell, J. Colin; Xing, Xin-Hui [Tsinghua University, Beijing (China). Dept. of Chemical Engineering

    2009-11-15

    Culture-independent molecular biological techniques, including 16S rRNA gene and functional gene clone libraries and microarray analyses using pmoA (encoding a key subunit of particulate methane monooxygenase), were applied to investigate the methanotroph community structure in alkaline soil from a Chinese coal mine. This environment contained a high diversity of methanotrophs, including the type II methanotrophs Methylosinus/Methylocystis, type I methanotrophs related to Methylobacter/Methylosoma and Methylococcus, and a number of as yet uncultivated methanotrophs. In order to identify the metabolically active methane-oxidizing bacteria from this alkaline environment, DNA stable isotope probing (DNA-SIP) experiments using {sup 13}CH{sub 4} were carried out. This showed that both type I and type II methanotrophs were active, together with methanotrophs related to Methylocella, which had previously been found only in acidic environments. Methylotrophs, including Methylopila and Hyphomicrobium, were also detected in soil DNA and after DNA-SIP experiments. DNA sequence information on the most abundant, active methanotrophs in this alkaline soil will facilitate the design of oligonucleotide probes to monitor enrichment cultures when isolating key alkaliphilic methanotrophs from such environments.

  10. Ultrastable α phase nickel hydroxide as energy storage materials for alkaline secondary batteries

    Science.gov (United States)

    Huang, Haili; Guo, Yinjian; Cheng, Yuanhui

    2018-03-01

    α Phase nickel hydroxide (α-Ni(OH)2) has higher theoretical capacity than that of commercial β phase Ni(OH)2. But the low stability inhibits its wide application in alkaline rechargeable batteries. Here, we propose a totally new idea to stabilize α phase Ni(OH)2 by introducing large organic molecule into the interlayer spacing together with doping multivalent cobalt into the layered Ni(OH)2 host. Ethylene glycol is served as neutral stabilizer in the interlayer spacing. Nickel is substituted by cobalt to increase the electrostatic attraction between layered Ni(OH)2 host and anion ions in the interlayer spacing. Polyethylene glycol (PEG-200) is utilized to design a three-dimensional network structure. This prepared α-Ni(OH)2-20 exhibits specific capacity as high as 334 mAh g-1and good structural stability even after immersing into strong alkaline zincate solution for 20 days. Ni(OH)2 electrode with a specific capacity of 35 mAh cm-2 is fabricated and used as positive electrode in zinc-nickel single flow batteries, which also shows good cycling stability. This result can provide an important guideline for the rational design and preparation of highly active and stable α phase Ni(OH)2 for alkaline secondary battery.

  11. Effect of alkaline microwaving pretreatment on anaerobic digestion and biogas production of swine manure.

    Science.gov (United States)

    Yu, Tao; Deng, Yihuan; Liu, Hongyu; Yang, Chunping; Wu, Bingwen; Zeng, Guangming; Lu, Li; Nishimura, Fumitake

    2017-05-10

    Microwave assisted with alkaline (MW-A) condition was applied in the pretreatment of swine manure, and the effect of the pretreatment on anaerobic treatment and biogas production was evaluated in this study. The two main microwaving (MW) parameters, microwaving power and reaction time, were optimized for the pretreatment. Response surface methodology (RSM) was used to investigate the effect of alkaline microwaving process for manure pretreatment at various values of pH and energy input. Results showed that the manure disintegration degree was maximized of 63.91% at energy input of 54 J/g and pH of 12.0, and variance analysis indicated that pH value played a more important role in the pretreatment than in energy input. Anaerobic digestion results demonstrated that MW-A pretreatment not only significantly increased cumulative biogas production, but also shortened the duration for a stable biogas production rate. Therefore, the alkaline microwaving pretreatment could become an alternative process for effective treatment of swine manure.

  12. Geochemical modeling of the influence of silicate mineral alteration on alkalinity production and carbonate precipitation

    Science.gov (United States)

    Herda, Gerhard; Kraemer, Stephan M.; Gier, Susanne; Meister, Patrick

    2016-04-01

    High CO2 partial pressure (pCO2) in deep rock reservoirs causes acidification of the porefluid. Such conditions occur during injection and subsurface storage of CO2 (to prevent the release of greenhouse gas) but also naturally in zones of strong methanogenic microbial activity in organic matter-rich ocean margin sediments. The acidic fluids are corrosive to carbonates and bear the risk of leakage of CO2 gas to the surface. Porefluid acidification may be moderated by processes that increase the alkalinity, i.e. that produce weak acid anions capable of buffering the acidification imposed by the CO2. Often, alkalinity increases as a result of anaerobic microbial activity, such as anaerobic oxidation of methane. However, on a long term the alteration of silicates, in particular, clay minerals, may be a more efficient mechanism of alkalinity production. Under altered temperature, pressure and porefluid composition at depth, clay minerals may change to thermodynamically more stable states, thereby increasing the alkalinity of the porefluid by partial leaching of Mg-(OH)2 and Ca-(OH)2 (e.g. Wallmann et al., 2008; Mavromatis et al., 2014). This alteration may even be enhanced by a high pCO2. Thus, silicate alteration can be essential for a long-term stabilization of volatile CO2 in the form of bicarbonate or may even induce precipitation of carbonate minerals, but these processes are not fully understood yet. The goal of this study is to simulate the alkalinity effect of silicate alteration under diagenetic conditions and high pCO2 by geochemical modeling. We are using the program PHREEQC (Parkhurst and Appelo, 2013) to generate high rock/fluid ratio characteristics for deep subsurface rock reservoirs. Since we are interested in the long-term evolution of diagenetic processes, over millions of years, we do not consider kinetics but calculate the theoretically possible equilibrium conditions. In a first step we are calculating the saturation state of different clay minerals

  13. Synthesis and structure of alkaline earth and rare earth metal doped C70

    International Nuclear Information System (INIS)

    Takenobu, Taishi; Iwasa, Yoshihiro; Ito, Takayoshi; Mitani, Tadaoki

    2001-01-01

    We have investigated the structure sequence of alkaline earth (A=Ba, Sr) and rare earth metal (R=Eu) doped C 70 binary system. X-ray diffraction measurements revealed that there exist at least four stable phases at x=3, 4, 6, and 9 in A x C 70 and two stable phases at x=3, and 9 in R x C 70 . Among them, structural models are presented for Ba 4 C 70 , Sr 3 C 70 , and Eu 3 C 70 . Ba 4 C 70 takes an analogous structure to orthorhombic Ba 4 C 60 . Sr 3 C 70 and Eu 3 C 70 have monoclinic cell and their diffraction patterns are quite similar to that of Sm 3 C 70 , which involves a unique C 70 -metal-C 70 dimer structure. Preliminary results of Raman spectroscopy and magnetization measurement suggest the highly reduction state for A 9 C 70 and ferromagnetic interaction for Eu x C 70

  14. 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.

  15. Theory of stable allocations

    Directory of Open Access Journals (Sweden)

    Pantelić Svetlana

    2014-01-01

    Full Text Available The Swedish Royal Academy awarded the 2012 Nobel Prize in Economics to Lloyd Shapley and Alvin Roth, for the theory of stable allocations and the practice of market design. These two American researchers worked independently from each other, combining basic theory and empirical investigations. Through their experiments and practical design they generated a flourishing field of research and improved the performance of many markets. Born in 1923 in Cambridge, Massachusetts, Shapley defended his doctoral thesis at Princeton University in 1953. For many years he worked at RAND, and for more than thirty years he was a professor at UCLA University. He published numerous scientific papers, either by himself or in cooperation with other economists.

  16. 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.

  17. 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)

  18. 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+

  19. 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

  20. 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

  1. 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

  2. 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.

  3. 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

  4. 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.

  5. 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.)

  6. Bi-stable optical actuator

    Science.gov (United States)

    Holdener, Fred R.; Boyd, Robert D.

    2000-01-01

    The present invention is a bi-stable optical actuator device that is depowered in both stable positions. A bearing is used to transfer motion and smoothly transition from one state to another. The optical actuator device may be maintained in a stable position either by gravity or a restraining device.

  7. 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  |

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. 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 ...

  13. 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 ...

  14. 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 ...

  15. 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

  16. 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.

  17. 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.

  18. 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

  19. Influence of alkalinity and VFAs on the performance of an UASB reactor with recirculation for the treatment of Tequila vinasses.

    Science.gov (United States)

    López-López, Alberto; León-Becerril, Elizabeth; Rosales-Contreras, María Elena; Villegas-García, Edgardo

    2015-01-01

    The main problem linked to the stability of upflow anaerobic sludge blanket (UASB) reactors during the treatment of Tequila vinasse is the high acidity and the null alkalinity present in this effluent. This research evaluates the effect of alkalinity and volatile fatty acids (VFAs) concentration on the performance of an UASB reactor with recirculation of the effluent for removing organic matter and biogas production from Tequila vinasses. Recirculation of the effluent reduces the impact of VFAs and organic matter concentration present in the influent, inducing the stability of the reactor. The UASB reactor was operated during 235 days at organic loading rates from 2.5 to 20.0 kg m(-3) d(-1), attaining a removal efficiency of COD greater than 75% with a methane yield of 335 ml CH4 g(-1) COD at SPT, maintaining a ratio of VFAs/Alk ≤ 0.5. Therefore, an optimal ratio of VFAs/Alk was established for the system operating in stable conditions for the treatment of Tequila vinasses. Under these conditions, the alkalinity was recuperated by the system itself, without the addition of external alkalinity.

  20. Influence of alkali and alkaline earth elements on the uptake of radionuclides by Pleurototus eryngii fruit bodies

    Energy Technology Data Exchange (ETDEWEB)

    Guillen, J., E-mail: fguillen@unex.es [LARUEX, Dpt. Applied Physics, Faculty of Veterinary Science, University of Extremadura, Avda. Universidad, s/n, 10071 Caceres (Spain); Baeza, A.; Salas, A. [LARUEX, Dpt. Applied Physics, Faculty of Veterinary Science, University of Extremadura, Avda. Universidad, s/n, 10071 Caceres (Spain)

    2012-04-15

    In the literature, there are many data available on radionuclide contents and their transfer to different species of mushrooms. There are some variables, however, which affect the transfer but are very difficult to observe in collected wild mushrooms. An example is the effect of different concentrations of alkali and alkaline earth elements in the soil. Modification of these concentrations in the soil solution has traditionally been used as a countermeasure to deal with radioactively contaminated areas. In the present work, fruiting bodies of Pleurotus eryngii, a saprophytic mushroom, were grown under controlled laboratory conditions, varying the content of alkali (potassium and caesium) and alkaline earth (calcium and strontium) elements. The transfer of {sup 134}Cs, {sup 85}Sr, and {sup 60}Co (added to the cultures) and of natural {sup 210}Pb was analysed by increasing the content of each stable element considered. A significant, but nonlinear, enhancement of stable caesium and {sup 134}Cs was observed with increasing content of stable caesium in the substrate/mycelium. The transfer of {sup 85}Sr decreased with the addition of each stable cation, whereas the {sup 60}Co and {sup 210}Pb transfers were unaffected. - Highlights: Black-Right-Pointing-Pointer The addition of stable potassium did not affect the uptake of radiocaesium. Black-Right-Pointing-Pointer The addition of stable caesium increased the stable caesium and {sup 134}Cs content in the fruiting bodies of Pleurotus eryngii. Black-Right-Pointing-Pointer The addition of calcium reduced the content of calcium and {sup 85}Sr in the fruiting bodies. Black-Right-Pointing-Pointer These countermeasures did not work properly in the case of {sup 60}Co and {sup 210}Pb, no effect was observed.

  1. Influence of alkali and alkaline earth elements on the uptake of radionuclides by Pleurototus eryngii fruit bodies

    International Nuclear Information System (INIS)

    Guillén, J.; Baeza, A.; Salas, A.

    2012-01-01

    In the literature, there are many data available on radionuclide contents and their transfer to different species of mushrooms. There are some variables, however, which affect the transfer but are very difficult to observe in collected wild mushrooms. An example is the effect of different concentrations of alkali and alkaline earth elements in the soil. Modification of these concentrations in the soil solution has traditionally been used as a countermeasure to deal with radioactively contaminated areas. In the present work, fruiting bodies of Pleurotus eryngii, a saprophytic mushroom, were grown under controlled laboratory conditions, varying the content of alkali (potassium and cæsium) and alkaline earth (calcium and strontium) elements. The transfer of 134 Cs, 85 Sr, and 60 Co (added to the cultures) and of natural 210 Pb was analysed by increasing the content of each stable element considered. A significant, but nonlinear, enhancement of stable cæsium and 134 Cs was observed with increasing content of stable cæsium in the substrate/mycelium. The transfer of 85 Sr decreased with the addition of each stable cation, whereas the 60 Co and 210 Pb transfers were unaffected. - Highlights: ► The addition of stable potassium did not affect the uptake of radiocaesium. ► The addition of stable caesium increased the stable caesium and 134 Cs content in the fruiting bodies of Pleurotus eryngii. ► The addition of calcium reduced the content of calcium and 85 Sr in the fruiting bodies. ► These countermeasures did not work properly in the case of 60 Co and 210 Pb, no effect was observed.

  2. Amphiboles as indicators of mantle source contamination: Combined evaluation of stable H and O isotope compositions and trace element ratios

    NARCIS (Netherlands)

    Demény, A.; Harangi, S.; Vennemann, T.W.; Casillas, R.; Horváth, P.; Milton, A.J.; Mason, P.R.D.; Ulianov, A.

    2012-01-01

    Stable isotope and trace element compositions of igneous amphiboles from different tectonic settings (ocean island basalts, intraplate alkaline basalts, subduction-related andesitic complexes) were compiled to help understand the role of fluids and melts in subduction-related mantle metasomatism

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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).

  9. 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

  10. 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.

  11. 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.

  12. One-dimensional stable distributions

    CERN Document Server

    Zolotarev, V M

    1986-01-01

    This is the first book specifically devoted to a systematic exposition of the essential facts known about the properties of stable distributions. In addition to its main focus on the analytic properties of stable laws, the book also includes examples of the occurrence of stable distributions in applied problems and a chapter on the problem of statistical estimation of the parameters determining stable laws. A valuable feature of the book is the author's use of several formally different ways of expressing characteristic functions corresponding to these laws.

  13. 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

  14. A Novel Low-Temperature Alkaline Lipase from Acinetobacter johnsonii LP28 Suitable for Detergent Formulation

    Directory of Open Access Journals (Sweden)

    Hai Kuan Wang

    2011-01-01

    Full Text Available A strain LP28 that produces alkaline and low-temperature lipase was isolated from the soil collected from the Bay of Bohai, PR China and identified as Acinetobacter johnsonii using 16S rDNA sequencing. The lipase was purified to homogeneity by centrifugation, followed by ammonium sulphate precipitation, dialysis, ion exchange chromatography on cellulose DE-52 and gel filtration chromatography on Sephadex G-75. The enzyme was purified about 34-fold with a final yield of 13 % and the relative molecular mass of the enzyme was determined to be 53 kDa by SDS-PAGE. The purified enzyme exhibited maximum activity at 30 °C and pH=9.0, and retained 94.53 % of its maximum activity at 20 °C. The enzyme was stable at 50 °C and retained 80.9 % of its original activity for 30 min. It was also highly stable in a pH range of 8.0–11.0. The enzyme hydrolyzed a wide range of oils and showed a high level of lipase activity in hydrolyzing tributyrin. The enzyme activity was promoted in the presence of Na+, Ca2+, K+, Mg2+ and sodium citrate. Ba2+, Mn2+, Cr3+ and Co2+ did not affect the enzyme activity, whereas the presence of Al3+, Cu2+, Fe2+, Fe3+, Zn2+ and EDTA reduced the enzyme activity. Regarding the stability of detergent process, the enzyme was highly stable in the presence of various oxidizing agents, some commercial detergents and alkaline protease, and its activity was also promoted by most of the surfactants, viz. Tween 20, Tween 80, sodium cholate, sodium taurocholate and saponin. For these characteristics, the lipase from Acinetobacter johnsonii LP28 showed good potential as an additive in laundry detergent formulation.

  15. Alkaline sodium borohydride gel as a hydrogen source for PEMFC or an energy carrier for NaBH{sub 4}-air battery

    Energy Technology Data Exchange (ETDEWEB)

    Liu, B.H. [Department of Materials and Engineering, Zhejiang University (China); Li, Z.P.; Chen, L.L. [Department of Chemical and Biochemical Engineering, Zhejiang University, Hangzhou 310027 (China)

    2008-05-15

    In this preliminary study, we tried to use sodium polyacrylate as the super absorbent polymer to form alkaline NaBH{sub 4} gel and explored its possibilities for borohydride hydrolysis and borohydride electro-oxidation. It was found that the absorption capacity of sodium polyacrylate decreased with increasing NaBH{sub 4} concentration. The formed gel was rather stable in the sealed vessel but tended to slowly decompose in open air. Hydrogen generation from the gel was carried out using CoCl{sub 2} catalyst precursor solutions. Hydrogen generation rate from the alkaline NaBH{sub 4} gel was found to be higher and impurities in hydrogen were less than that from the alkaline NaBH{sub 4} solution. The NaBH{sub 4} gel also successfully powered a NaBH{sub 4}-air battery. (author)

  16. Alkaline sodium borohydride gel as a hydrogen source for PEMFC or an energy carrier for NaBH 4-air battery

    Science.gov (United States)

    Liu, B. H.; Li, Z. P.; Chen, L. L.

    In this preliminary study, we tried to use sodium polyacrylate as the super absorbent polymer to form alkaline NaBH 4 gel and explored its possibilities for borohydride hydrolysis and borohydride electro-oxidation. It was found that the absorption capacity of sodium polyacrylate decreased with increasing NaBH 4 concentration. The formed gel was rather stable in the sealed vessel but tended to slowly decompose in open air. Hydrogen generation from the gel was carried out using CoCl 2 catalyst precursor solutions. Hydrogen generation rate from the alkaline NaBH 4 gel was found to be higher and impurities in hydrogen were less than that from the alkaline NaBH 4 solution. The NaBH 4 gel also successfully powered a NaBH 4-air battery.

  17. Stable isotope research pool inventory

    International Nuclear Information System (INIS)

    1980-12-01

    This report contains a listing of electromagnetically separated stable isotopes which are available for distribution within the United States for non-destructive research use from the Oak Ridge National Laboratory on a loan basis. This inventory includes all samples of stable isotopes in the Materials Research Collection and does not designate whether a sample is out on loan or in reprocessing

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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

  4. 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

  5. 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.

  6. 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

  7. 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

  8. 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

  9. 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...

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. Stable configurations in social networks

    Science.gov (United States)

    Bronski, Jared C.; DeVille, Lee; Ferguson, Timothy; Livesay, Michael

    2018-06-01

    We present and analyze a model of opinion formation on an arbitrary network whose dynamics comes from a global energy function. We study the global and local minimizers of this energy, which we call stable opinion configurations, and describe the global minimizers under certain assumptions on the friendship graph. We show a surprising result that the number of stable configurations is not necessarily monotone in the strength of connection in the social network, i.e. the model sometimes supports more stable configurations when the interpersonal connections are made stronger.

  16. Development of Stable Isotope Technology

    International Nuclear Information System (INIS)

    Jeong, Do Young; Kim, Cheol Jung; Han, Jae Min

    2009-03-01

    KAERI has obtained an advanced technology with singular originality for laser stable isotope separation. Objectives for this project are to get production technology of Tl-203 stable isotope used for medical application and are to establish the foundation of the pilot system, while we are taking aim at 'Laser Isotope Separation Technology to make resistance to the nuclear proliferation'. And we will contribute to ensuring a nuclear transparency in the world society by taking part in a practical group of NSG and being collaboration with various international groups related to stable isotope separation technology

  17. 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.

  18. 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

  19. Experimental and analytical analysis of polarization and water transport behaviors of hydrogen alkaline membrane fuel cell

    Science.gov (United States)

    Huo, Sen; Zhou, Jiaxun; Wang, Tianyou; Chen, Rui; Jiao, Kui

    2018-04-01

    Experimental test and analytical modeling are conducted to investigate the operating behavior of an alkaline electrolyte membrane (AEM) fuel cell fed by H2/air (or O2) and explore the effect of various operating pressures on the water transfer mechanism. According to the experimental test, the cell performance is greatly improved through increasing the operating pressure gradient from anode to cathode which leads to significant liquid water permeation through the membrane. The high frequency resistance of the A901 alkaline membrane is observed to be relatively stable as the operating pressure varies based on the electrochemical impedance spectroscopy (EIS) method. Correspondingly, based on the modeling prediction, the averaged water content in the membrane electrode assembly (MEA) does not change too much which leads to the weak variation of membrane ohmic resistance. This reveals that the performance enhancement should give the credit to better electro-chemical reaction kinetics for both the anode and cathode, also prone by the EIS results. The reversion of water back diffusion direction across the membrane is also observed through analytical solution.

  20. 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.

  1. 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)

  2. 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.

  3. 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)

  4. 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.

  5. Studies of alkaline mediated phosphate migration in synthetic phosphoethanolamine l-glycero-d-manno-heptoside derivatives

    International Nuclear Information System (INIS)

    Stewart, A.; Martin, A.; Richards, J.C.; Bernlind, C.; Oscarson, S.; Schweda, E.K.H.

    1998-01-01

    Synthetic 2-, 3-, 4- and 6-monophosphate derivatives of methyl α-d-mannopyranosides, the 4-, 6- and 7-monophosphate derivatives of methyl l-glycero-α-d-manno-heptopyranosides and the corresponding phosphoethanolamine derivatives and a 6,7-cyclic phosphate analogue of methyl l-glycero-α-d-manno-heptopyranoside were used to study phosphate migration and hydrolysis when subjected to strong alkaline conditions (4 M KOH, 120 C, 18 h). The resulting products were analyzed by 1 H NMR spectroscopy and electrospray mass spectrometry. It was found that phosphate substituents were stable under these conditions and neither migration nor hydrolysis was observed except for the heptose 7-phosphate, which gave a substantial amount of phosphate hydrolysis. In phosphoethanolamine-substituted compounds migration to adjacent positions with concomitant loss of ethanolamine was found together with hydrolysis. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  6. Corrosion properties of HLW and spent fuel overpacks in highly alkaline environments

    International Nuclear Information System (INIS)

    Kursten, B.

    2009-01-01

    Throughout the world, deep geological disposal in stable rocks with low groundwater flow is considered for the long-term management of long-lived radioactive waste (vitrified high-level waste - VHLW - and spent fuel - SF).The main advantage of the SC design, with respect to corrosion, is that under the predicted conditions (i.e. highly alkaline concrete buffer), the carbon steel overpack is expected to undergo uniform corrosion (passive dissolution). The key objective of this study is to demonstrate that the carbon steel overpack will be able to ensure complete containment of the radioactivity at least during the thermal phase, this is the period during which the temperature of the host rock is expected to lie above the range of temperatures within which nominal radionuclide migration properties can be relied upon

  7. Stable isotope research pool inventory

    International Nuclear Information System (INIS)

    1984-03-01

    This report contains a listing of electromagnetically separated stable isotopes which are available at the Oak Ridge National Laboratory for distribution for nondestructive research use on a loan basis. This inventory includes all samples of stable isotopes in the Research Materials Collection and does not designate whether a sample is out on loan or is in reprocessing. For some of the high abundance naturally occurring isotopes, larger amounts can be made available; for example, Ca-40 and Fe-56

  8. French days on stable isotopes

    International Nuclear Information System (INIS)

    2000-01-01

    These first French days on stable isotopes took place in parallel with the 1. French days of environmental chemistry. Both conferences had common plenary sessions. The conference covers all aspects of the use of stable isotopes in the following domains: medicine, biology, environment, tracer techniques, agronomy, food industry, geology, petroleum geochemistry, cosmo-geochemistry, archaeology, bio-geochemistry, hydrology, climatology, nuclear and particle physics, astrophysics, isotope separations etc.. Abstracts available on CD-Rom only. (J.S.)

  9. Stable isotope research pool inventory

    International Nuclear Information System (INIS)

    1982-01-01

    This report contains a listing of electromagnetically separated stable isotopes which are available for distribution within the United States for nondestructive research use from the Oak Ridge National Laboratory on a loan basis. This inventory includes all samples of stable isotopes in the Material Research Collection and does not designate whether a sample is out on loan or in reprocessing. For some of the high abundance naturally occurring isotopes, larger amounts can be made available; for example, Ca-40 and Fe-56

  10. Pharmaceuticals labelled with stable isotopes

    International Nuclear Information System (INIS)

    Krumbiegel, P.

    1986-11-01

    The relatively new field of pharmaceuticals labelled with stable isotopes is reviewed. Scientific, juridical, and ethical questions are discussed concerning the application of these pharmaceuticals in human medicine. 13 C, 15 N, and 2 H are the stable isotopes mainly utilized in metabolic function tests. Methodical contributions are given to the application of 2 H, 13 C, and 15 N pharmaceuticals showing new aspects and different states of development in the field under discussion. (author)

  11. Chemically and compositionally modified solid solution disordered multiphase nickel hydroxide positive electrode for alkaline rechargeable electrochemical cells

    Science.gov (United States)

    Ovshinsky, Stanford R.; Corrigan, Dennis; Venkatesan, Srini; Young, Rosa; Fierro, Christian; Fetcenko, Michael A.

    1994-01-01

    A high capacity, long cycle life positive electrode for use in an alkaline rechargeable electrochemical cell comprising: a solid solution nickel hydroxide material having a multiphase structure that comprises at least one polycrystalline .gamma.-phase including a polycrystalline .gamma.-phase unit cell comprising spacedly disposed plates with at least one chemical modifier incorporated around the plates, the plates having a range of stable intersheet distances corresponding to a 2.sup.+ oxidation state and a 3.5.sup.+, or greater, oxidation state; and at least one compositional modifier incorporated into the solid solution nickel hydroxide material to promote the multiphase structure.

  12. 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.

  13. Imidazolium-Based Polymeric Materials as Alkaline Anion-Exchange Fuel Cell Membranes

    Science.gov (United States)

    Narayan, Sri R.; Yen, Shiao-Ping S.; Reddy, Prakash V.; Nair, Nanditha

    2012-01-01

    Polymer electrolyte membranes that conduct hydroxide ions have potential use in fuel cells. A variety of polystyrene-based quaternary ammonium hydroxides have been reported as anion exchange fuel cell membranes. However, the hydrolytic stability and conductivity of the commercially available membranes are not adequate to meet the requirements of fuel cell applications. When compared with commercially available membranes, polystyrene-imidazolium alkaline membrane electrolytes are more stable and more highly conducting. At the time of this reporting, this has been the first such usage for imidazolium-based polymeric materials for fuel cells. Imidazolium salts are known to be electrochemically stable over wide potential ranges. By controlling the relative ratio of imidazolium groups in polystyrene-imidazolium salts, their physiochemical properties could be modulated. Alkaline anion exchange membranes based on polystyrene-imidazolium hydroxide materials have been developed. The first step was to synthesize the poly(styrene-co-(1-((4-vinyl)methyl)-3- methylimidazolium) chloride through a free-radical polymerization. Casting of this material followed by in situ treatment of the membranes with sodium hydroxide solutions provided the corresponding hydroxide salts. Various ratios of the monomers 4-chloromoethylvinylbenzine (CMVB) and vinylbenzine (VB) provided various compositions of the polymer. The preferred material, due to the relative ease of casting the film, and its relatively low hygroscopic nature, was a 2:1 ratio of CMVB to VB. Testing confirmed that at room temperature, the new membranes outperformed commercially available membranes by a large margin. With fuel cells now in use at NASA and in transportation, and with defense potential, any improvement to fuel cell efficiency is a significant development.

  14. Protection of Si photocathode using TiO2 deposited by high power impulse magnetron sputtering for H2 evolution in alkaline media

    DEFF Research Database (Denmark)

    Bae, Dowon; Shayestehaminzadeh, Seyedmohammad; Thorsteinsson, Einar B.

    2016-01-01

    Si is an excellent absorber material for use in photoelectrochemical (PEC) hydrogen production. Only a few studies have been done using Si in alkaline electrolyte for hydrogen evolution due to its poor chemical stability in high pH electrolyte, indicating that a chemically stable protection layer...

  15. 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.

  16. 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.

  17. 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)

  18. Magmatism and fenitization in the Cretaceous potassium-alkaline-carbonatitic complex of Ipanema São Paulo State, Brazil

    Science.gov (United States)

    Guarino, Vincenza; Azzone, Rogério Guitarrari; Brotzu, Pietro; de Barros Gomes, Celso; Melluso, Leone; Morbidelli, Lucio; Ruberti, Excelso; Tassinari, Colombo Celso Gaeta; Brilli, Mauro

    2012-01-01

    The Ipanema alkaline-carbonatitic complex is part of the Meso-Cenozoic alkaline magmatism located within the southeastern part of the Brazilian Platform. Drill-core and field sampling have indicated the occurrence of glimmerites, with subordinate shonkinites (mela-syenites), clinopyroxene-bearing glimmerites, diorites and syenites. The glimmerites are cross-cut by lamprophyric dykes and calciocarbonatites. Fenitization has deeply affected the country rocks, originating dioritic and syenitic rocks. The Ipanema rocks show a distinct potassic affinity. The initial Sr-Nd- isotopic composition of the Ipanema rocks (87Sr/86Sr = 0.70661-0.70754 and 143Nd/144Nd = 0.51169-0.51181) is similar to that of tholeiitic and potassium-rich-alkaline rocks of the Eastern Paraguay. Stable isotope data for the Ipanema calciocarbonatite suggest interaction with fluids at temperatures typical of hydrothermal stages, as hypothesized for other carbonatite complexes from southeastern Brazil. The chemical differences between the lamprophyre, glimmerites, carbonatites, apatitites and magnetitites, and the absence of marked REE enrichment in the evolved lithologies, all indicate that fractional crystallization and accumulus of liquidus phases in a magma reservoir, likely coupled with liquid immiscibility processes, may have played an important role in the genesis of the Ipanema rocks.

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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

  4. 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)

  5. 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.

  6. 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.

  7. [Current Treatment of Stable Angina].

    Science.gov (United States)

    Toggweiler, Stefan; Jamshidi, Peiman; Cuculi, Florim

    2015-06-17

    Current therapy for stable angina includes surgical and percutaneous revascularization, which has been improved tremendously over the last decades. Smoking cessation and regular exercise are the cornerstone for prevention of further cerebrovascular events. Medical treatment includes treatment of cardiovascular risk factors and antithrombotic management, which can be a challenge in some patients. Owing to the fact the coronary revascularization is readily accessible these days in many industrialized countries, the importance of antianginal therapy has decreased over the past years. This article presents a contemporary overview of the management of patients with stable angina in the year 2015.

  8. 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

  9. Toward stable nickel catalysts for aqueous phase reforming of biomass-derived feedstock under reducing and alkaline conditions

    NARCIS (Netherlands)

    Haasterecht, van T.; Ludding, C.C.I.; Jong, de K.P.; Bitter, J.H.

    2014-01-01

    Nickel nanoparticles supported on carbon nanofibers (CNF) can be stabilized in aqueous phase processes at elevated temperatures and pressures by tuning the reaction conditions to control Ni oxidation and leaching. As a showcase, Ni/CNF was used for the production of hydrogen via aqueous phase

  10. Application of a fluidized bed reactor charged with aragonite for control of alkalinity, pH and carbon dioxide in marine recirculating aquaculture systems

    Science.gov (United States)

    Paul S Wills, PhD; Pfeiffer, Timothy; Baptiste, Richard; Watten, Barnaby J.

    2016-01-01

    Control of alkalinity, dissolved carbon dioxide (dCO2), and pH are critical in marine recirculating aquaculture systems (RAS) in order to maintain health and maximize growth. A small-scale prototype aragonite sand filled fluidized bed reactor was tested under varying conditions of alkalinity and dCO2 to develop and model the response of dCO2 across the reactor. A large-scale reactor was then incorporated into an operating marine recirculating aquaculture system to observe the reactor as the system moved toward equilibrium. The relationship between alkalinity dCO2, and pH across the reactor are described by multiple regression equations. The change in dCO2 across the small-scale reactor indicated a strong likelihood that an equilibrium alkalinity would be maintained by using a fluidized bed aragonite reactor. The large-scale reactor verified this observation and established equilibrium at an alkalinity of approximately 135 mg/L as CaCO3, dCO2 of 9 mg/L, and a pH of 7.0 within 4 days that was stable during a 14 day test period. The fluidized bed aragonite reactor has the potential to simplify alkalinity and pH control, and aid in dCO2 control in RAS design and operation. Aragonite sand, purchased in bulk, is less expensive than sodium bicarbonate and could reduce overall operating production costs.

  11. Possibility of stable quark stars

    International Nuclear Information System (INIS)

    Bowers, R.L.; Gleeson, A.M.; Pedigo, R.D.

    1976-08-01

    A recent zero temperature equation of state which contains quark-partons separated from conventional baryons by a phase transition is used to investigate the stability of quark stars. The sensitivity to the input physics is also considered. The conclusions, which are found to be relatively model independent, indicate that a separately identifiable class of stable objects called quark stars does not exist

  12. Radiation-stable polyolefin compositions

    International Nuclear Information System (INIS)

    Rekers, J.W.

    1986-01-01

    This invention relates to compositions of olefinic polymers suitable for high energy radiation treatment. In particular, the invention relates to olefinic polymer compositions that are stable to sterilizing dosages of high energy radiation such as a gamma radiation. Stabilizers are described that include benzhydrol and benzhydrol derivatives; these stabilizers may be used alone or in combination with secondary antioxidants or synergists

  13. Synthesis, characterization, and catalytic properties of stable mesoporous molecular sieve MCM-41 prepared from zeolite mordenite

    International Nuclear Information System (INIS)

    Wang Shan; Dou Tao; Li Yuping; Zhang Ying; Li Xiaofeng; Yan Zichun

    2004-01-01

    Mesoporous molecular sieves (denoted as M-MCM-41) with ordered hexagonal structure have been successfully synthesized from the assembly of precursors from preformed zeolite Mordenite with CTAB surfactant micelle in alkaline media. The samples were characterized by XRD, N 2 adsorption, IR and DTG. The materials exhibit highly hydrothermal stability, as compared with conventional MCM-41. Characterization results indicate that the mesoporous walls of M-MCM-41 contain the secondary building units similar to those in microporous crystal of zeolite Mordenite. In catalytic dealkylation of C10 + aromatic hydrocarbon, M-MCM-41 shows higher activities in comparison with Mordenite and MCM-41, which would be ascribed to the combination of advantages of both MCM-41 (large pores) and Mordenite (strong acidity). Furthermore, this synthesis strategy could be used as a new general method for the preparation of hydrothermally stable mesoporous aluminosilicate materials under alkaline conditions

  14. Simulation of dual carbon-bromine stable isotope fractionation during 1,2-dibromoethane degradation.

    Science.gov (United States)

    Jin, Biao; Nijenhuis, Ivonne; Rolle, Massimo

    2018-06-01

    We performed a model-based investigation to simultaneously predict the evolution of concentration, as well as stable carbon and bromine isotope fractionation during 1,2-dibromoethane (EDB, ethylene dibromide) transformation in a closed system. The modelling approach considers bond-cleavage mechanisms during different reactions and allows evaluating dual carbon-bromine isotopic signals for chemical and biotic reactions, including aerobic and anaerobic biological transformation, dibromoelimination by Zn(0) and alkaline hydrolysis. The proposed model allowed us to accurately simulate the evolution of concentrations and isotope data observed in a previous laboratory study and to successfully identify different reaction pathways. Furthermore, we illustrated the model capabilities in degradation scenarios involving complex reaction systems. Specifically, we examined (i) the case of sequential multistep transformation of EDB and the isotopic evolution of the parent compound, the intermediate and the reaction product and (ii) the case of parallel competing abiotic pathways of EDB transformation in alkaline solution.

  15. 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.

  16. 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.

  17. 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 ...

  18. 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.

  19. 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...

  20. 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

  1. 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 ...

  2. 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-.

  3. 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...

  4. 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

  5. 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

  6. 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...

  7. 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 ...

  8. 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

  9. 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…

  10. 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

  11. 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.

  12. 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...

  13. 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

  14. 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

  15. 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.

  16. 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).

  17. 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 ...

  18. 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.

  19. 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 ...

  20. 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

  1. 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.

  2. Toward Practical Secure Stable Matching

    Directory of Open Access Journals (Sweden)

    Riazi M. Sadegh

    2017-01-01

    Full Text Available The Stable Matching (SM algorithm has been deployed in many real-world scenarios including the National Residency Matching Program (NRMP and financial applications such as matching of suppliers and consumers in capital markets. Since these applications typically involve highly sensitive information such as the underlying preference lists, their current implementations rely on trusted third parties. This paper introduces the first provably secure and scalable implementation of SM based on Yao’s garbled circuit protocol and Oblivious RAM (ORAM. Our scheme can securely compute a stable match for 8k pairs four orders of magnitude faster than the previously best known method. We achieve this by introducing a compact and efficient sub-linear size circuit. We even further decrease the computation cost by three orders of magnitude by proposing a novel technique to avoid unnecessary iterations in the SM algorithm. We evaluate our implementation for several problem sizes and plan to publish it as open-source.

  3. Stable isotope research pool inventory

    International Nuclear Information System (INIS)

    1986-08-01

    This report contains a listing of electromagnetically separated stable isotopes which are available at the Oak Ridge National Laboratory for distribution for nondestructive research use on a loan basis. This inventory includes all samples of stable isotopes in the Research Materials Collection and does not designate whether a sample is out on loan or is in reprocessing. For some of the high-abundance, naturally occurring isotopes, larger amounts can be made available; for example, Ca-40 and Fe-56. All requests for the loan of samples should be submitted with a summary of the purpose of the loan to: Iotope Distribution Office, Oak Ridge National Laboratory, P.O. Box X, Oak Ridge, Tennessee 37831. Requests from non-DOE contractors and from foreign institutions require DOE approval

  4. Stable isotopes and the environment

    International Nuclear Information System (INIS)

    Krouse, H.R.

    1990-01-01

    Whereas traditionally, stable isotope research has been directed towards resource exploration and development, it is finding more frequent applications in helping to assess the impacts of resource utilization upon ecosystems. Among the many pursuits, two themes are evident: tracing the transport and conversions of pollutants in the environment and better understanding of the interplay among environmental receptors, e.g. food web studies. Stable isotope data are used primarily to identify the presence of pollutants in the environment and with a few exceptions, the consequence of their presence must be assessed by other techniques. Increasing attention has been given to the isotopic composition of humans with many potential applications in areas such as paleodiets, medicine, and criminology. In this brief overview examples are used from the Pacific Rim to illustrate the above concepts. 26 refs., 1 tab., 3 figs

  5. Long term behaviour of compacted argillite submitted to an alkaline fluid circulation

    International Nuclear Information System (INIS)

    Cuisinier, O.; Masrouri, F.; Deneele, Dimitri

    2010-01-01

    cementitious compounds that probably increased the shear strength, hence compensating for the decrease in density that would lower the shear strength. However, it seems that the formation of cementitious compounds is complicated because of the permanent flow of the alkaline water. The dissolved components leaking out of the material are dependent on the hydraulic properties of each mixture. Hence, even with such severe experimental conditions, there is no evidence of dramatic loss of shear strength of the studied materials in alkaline environment. The sand-MA is the most stable mixture, followed by the pure MA. The MX-80 mixture and lime-treated MA are the more reactive mixtures. This study showed that a significant mechanical alteration of the backfill is to be expected if conventional high lime concrete is to be used to build the concrete lining of the deep galleries. It is likely that the alteration of the mechanical behaviour of the backfill and its microstructure would be minimized if low pH and low-lime concretes are used. (authors)

  6. Towards stable acceleration in LINACS

    CERN Document Server

    Dubrovskiy, A D

    2014-01-01

    Ultra-stable and -reproducible high-energy particle beams with short bunches are needed in novel linear accelerators and, in particular, in the Compact Linear Collider CLIC. A passive beam phase stabilization system based on a bunch compression with a negative transfer matrix element R56 and acceleration at a positive off-crest phase is proposed. The motivation and expected advantages of the proposed scheme are outlined.

  7. Stable Structures for Distributed Applications

    OpenAIRE

    Eugen DUMITRASCU; Ion IVAN

    2008-01-01

    For distributed applications, we define the linear, tree and graph structure types with different variants and modalities to aggregate them. The distributed applications have assigned structures that through their characteristics influence the costs of stages for developing cycle and the costs for exploitation, transferred to each user. We also present the quality characteristics of a structure for a stable application, which is focused on stability characteristic. For that characteristic we ...

  8. 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

  9. 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

  10. 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.

  11. 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.

  12. 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%.

  13. 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.

  14. 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.

  15. 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)

  16. 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.)

  17. Formation of magnetite nanoparticles at low temperature: from superparamagnetic to stable single domain particles.

    Directory of Open Access Journals (Sweden)

    Jens Baumgartner

    Full Text Available The room temperature co-precipitation of ferrous and ferric iron under alkaline conditions typically yields superparamagnetic magnetite nanoparticles below a size of 20 nm. We show that at pH  =  9 this method can be tuned to grow larger particles with single stable domain magnetic (> 20-30 nm or even multi-domain behavior (> 80 nm. The crystal growth kinetics resembles surprisingly observations of magnetite crystal formation in magnetotactic bacteria. The physicochemical parameters required for mineralization in these organisms are unknown, therefore this study provides insight into which conditions could possibly prevail in the biomineralizing vesicle compartments (magnetosomes of these bacteria.

  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. 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)

  1. 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...

  2. 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.

  3. 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

  4. 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

  5. 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)

  6. Organic synthesis with stable isotopes

    International Nuclear Information System (INIS)

    Daub, G.H.; Kerr, V.N.; Williams, D.L.; Whaley, T.W.

    1978-01-01

    Some general considerations concerning organic synthesis with stable isotopes are presented. Illustrative examples are described and discussed. The examples include DL-2-amino-3-methyl- 13 C-butanoic-3,4- 13 C 2 acid (DL-valine- 13 C 3 ); methyl oleate-1- 13 C; thymine-2,6- 13 C 2 ; 2-aminoethanesulfonic- 13 C acid (taurine- 13 C); D-glucose-6- 13 C; DL-2-amino-3-methylpentanoic-3,4- 13 C 2 acid (DL-isoleucine- 13 C 2 ); benzidine- 15 N 2 ; and 4-ethylsulfonyl-1-naphthalene-sulfonamide- 15 N

  7. Stable isotopes - separation and application

    International Nuclear Information System (INIS)

    Lockhart, I.M.

    1980-01-01

    In this review, methods used for the separation of stable isotopes ( 12 C, 13 C, 14 N, 15 N, 16 O, 17 O, 18 O, 34 S) will be described. The synthesis of labelled compounds, techniques for detection and assay, and areas of application will also be discussed. Particular attention will be paid to the isotopes of carbon, nitrogen, and oxygen; to date, sulphur isotopes have only assumed a minor role. The field of deuterium chemistry is too extensive for adequate treatment; it will therefore be essentially excluded. (author)

  8. Stable agents for imaging investigations

    International Nuclear Information System (INIS)

    Tofe, A.J.

    1976-01-01

    This invention concerns highly stable compounds useful in preparing technetium 99m based scintiscanning exploration agents. The compounds of this invention include a pertechnetate reducing agent or a solution of oxidized pertechnetate and an efficient proportion, sufficient to stabilize the compounds in the presence of oxygen and of radiolysis products, of ascorbic acid or a pharmaceutically acceptable salt or ester of this acid. The invention also concerns a perfected process for preparing a technetium based exploration agent, consisting in codissolving the ascorbic acid or a pharmaceutically acceptable salt or ester of such an acid and a pertechnetate reducing agent in a solution of oxidized pertechnetate [fr

  9. 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...

  10. 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...

  11. 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 .

  12. 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.

  13. 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

  14. 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.

  15. 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)

  16. Stable cosmology in chameleon bigravity

    Science.gov (United States)

    De Felice, Antonio; Mukohyama, Shinji; Oliosi, Michele; Watanabe, Yota

    2018-02-01

    The recently proposed chameleonic extension of bigravity theory, by including a scalar field dependence in the graviton potential, avoids several fine-tunings found to be necessary in usual massive bigravity. In particular it ensures that the Higuchi bound is satisfied at all scales, that no Vainshtein mechanism is needed to satisfy Solar System experiments, and that the strong coupling scale is always above the scale of cosmological interest all the way up to the early Universe. This paper extends the previous work by presenting a stable example of cosmology in the chameleon bigravity model. We find a set of initial conditions and parameters such that the derived stability conditions on general flat Friedmann background are satisfied at all times. The evolution goes through radiation-dominated, matter-dominated, and de Sitter eras. We argue that the parameter space allowing for such a stable evolution may be large enough to encompass an observationally viable evolution. We also argue that our model satisfies all known constraints due to gravitational wave observations so far and thus can be considered as a unique testing ground of gravitational wave phenomenologies in bimetric theories of gravity.

  17. Stable Heavy Hadrons in ATLAS

    CERN Document Server

    Mackeprang, Rasmus

    2007-01-01

    Several extensions to the SM feature heavy long-lived particles with masses of O(10^2-10^3 GeV) and mean lifetimes fulfilling $CT \\geq 10m$. Among such theories are supersymmetric scenarios as well as extra-dimensional models in which the heavy new particles are seen as Kaluza-Klein excitations of the well-known SM particles. Such particles will, from the point of view of a collider experiment be seen as stable. This thesis is concerned with the case where the exotic heavy particles emph{can} be considered stable while traversing the detector. Specifically the case is considered where the particles in question carry the charge of the strong nuclear force, commonly referred to as emph{colour charge}. A simulation kit has been developed using GEANT4. This framework is the current standard in experimental particle physics for the simulation of interactions of particles with matter, and it is used extensively for detector simulation. The simulation describes the interactions of these particles with matter which i...

  18. 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.

  19. 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

  20. Stable isotope mass spectrometry in petroleum exploration

    International Nuclear Information System (INIS)

    Mathur, Manju

    1997-01-01

    The stable isotope mass spectrometry plays an important role to evaluate the stable isotopic composition of hydrocarbons. The isotopic ratios of certain elements in petroleum samples reflect certain characteristics which are useful for petroleum exploration

  1. Confirmation of the applicability of low alkaline cement-based material in the Horonobe Underground Research Laboratory

    International Nuclear Information System (INIS)

    Nakayama, Masashi; Niunoya, Sumio; Minamide, Masashi

    2016-01-01

    In Japan, high-level radioactive waste repository will be constructed in a stable host rock formation more than 300 m underground. Tunnel support is used for safety during the construction and operation, so, shotcrete and concrete lining are used as the tunnel support. Concrete is a composite material comprised of aggregate, cement, water and various additives. Low alkaline cement has been developed for the long term stability of the barrier systems whose performance could be negatively affected by highly alkaline conditions arising due to cement used in a repository. Japan Atomic Energy Agency (JAEA) has developed the low alkaline cement, named as HFSC (Highly fly-ash contained silicafume cement), containing over 60wt% of silicafume (SF) and Fly-ash (FA). JAEA is presently constructing the underground research laboratory (URL) at Horonobe for research and development in the geosciences and repository engineering technology. HFSC was used experimentally as the shotcrete material in construction of part of the 350 m deep gallery in the Horonobe URL in 2013. The objective of this experiment was to assess the performance of HFSC shotcrete in terms of mechanics, workability, durability, and so on. HFSC used in this experiment is composed of 40wt% OPC (Ordinary Portland Cement), 20wt% SF, and 40wt% FA. This composition was determined based on mechanical testing of various mixes of the above components. Because of the low OPC content, the strength of HFSC tends to be lower than that of OPC in normal concrete. The total length of tunnel constructed using HFSC shotcrete is about 112 m at 350 m deep drift. The workability of HFSC shotcrete was confirmed by this experimental construction. In this report, we present detailed results of the in-situ construction test. (author)

  2. Effect of short-term alkaline intervention on the performance of buffer-free single-chamber microbial fuel cell.

    Science.gov (United States)

    Yang, Na; Ren, Yueping; Li, Xiufen; Wang, Xinhua

    2017-06-01

    Anolyte acidification is a drawback restricting the electricity generation performance of the buffer-free microbial fuel cells (MFC). In this paper, a small amount of alkali-treated anion exchange resin (AER) was placed in front of the anode in the KCl mediated single-chamber MFC to slowly release hydroxyl ions (OH - ) and neutralize the H + ions that are generated by the anodic reaction in two running cycles. This short-term alkaline intervention to the KCl anolyte has promoted the proliferation of electroactive Geobacter sp. and enhanced the self-buffering capacity of the KCl-AER-MFC. The pH of the KCl anolyte in the KCl-AER-MFC increased and became more stable in each running cycle compared with that of the KCl-MFC after the short-term alkaline intervention. The maximum power density (P max ) of the KCl-AER-MFC increased from 307.5mW·m -2 to 542.8mW·m -2 , slightly lower than that of the PBS-MFC (640.7mW·m -2 ). The coulombic efficiency (CE) of the KCl-AER-MFC increased from 54.1% to 61.2% which is already very close to that of the PBS-MFC (61.9%). The results in this paper indicate that short-term alkaline intervention to the anolyte is an effective strategy to further promote the performance of buffer-free MFCs. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Stable rotating dipole solitons in nonlocal media

    DEFF Research Database (Denmark)

    Lopez-Aguayo, Servando; Skupin, Stefan; Desyatnikov, Anton S.

    2006-01-01

    We present the first example of stable rotating two-soliton bound states in nonlinear optical media with nonlocal response. We show that, in contrast to media with local response, nonlocality opens possibilities to generate stable azimuthons.......We present the first example of stable rotating two-soliton bound states in nonlinear optical media with nonlocal response. We show that, in contrast to media with local response, nonlocality opens possibilities to generate stable azimuthons....

  4. Tempered stable laws as random walk limits

    OpenAIRE

    Chakrabarty, Arijit; Meerschaert, Mark M.

    2010-01-01

    Stable laws can be tempered by modifying the L\\'evy measure to cool the probability of large jumps. Tempered stable laws retain their signature power law behavior at infinity, and infinite divisibility. This paper develops random walk models that converge to a tempered stable law under a triangular array scheme. Since tempered stable laws and processes are useful in statistical physics, these random walk models can provide a basic physical model for the underlying physical phenomena.

  5. Stable States of Biological Organisms

    Science.gov (United States)

    Yukalov, V. I.; Sornette, D.; Yukalova, E. P.; Henry, J.-Y.; Cobb, J. P.

    2009-04-01

    A novel model of biological organisms is advanced, treating an organism as a self-consistent system subject to a pathogen flux. The principal novelty of the model is that it describes not some parts, but a biological organism as a whole. The organism is modeled by a five-dimensional dynamical system. The organism homeostasis is described by the evolution equations for five interacting components: healthy cells, ill cells, innate immune cells, specific immune cells, and pathogens. The stability analysis demonstrates that, in a wide domain of the parameter space, the system exhibits robust structural stability. There always exist four stable stationary solutions characterizing four qualitatively differing states of the organism: alive state, boundary state, critical state, and dead state.

  6. Super-stable Poissonian structures

    International Nuclear Information System (INIS)

    Eliazar, Iddo

    2012-01-01

    In this paper we characterize classes of Poisson processes whose statistical structures are super-stable. We consider a flow generated by a one-dimensional ordinary differential equation, and an ensemble of particles ‘surfing’ the flow. The particles start from random initial positions, and are propagated along the flow by stochastic ‘wave processes’ with general statistics and general cross correlations. Setting the initial positions to be Poisson processes, we characterize the classes of Poisson processes that render the particles’ positions—at all times, and invariantly with respect to the wave processes—statistically identical to their initial positions. These Poisson processes are termed ‘super-stable’ and facilitate the generalization of the notion of stationary distributions far beyond the realm of Markov dynamics. (paper)

  7. Super-stable Poissonian structures

    Science.gov (United States)

    Eliazar, Iddo

    2012-10-01

    In this paper we characterize classes of Poisson processes whose statistical structures are super-stable. We consider a flow generated by a one-dimensional ordinary differential equation, and an ensemble of particles ‘surfing’ the flow. The particles start from random initial positions, and are propagated along the flow by stochastic ‘wave processes’ with general statistics and general cross correlations. Setting the initial positions to be Poisson processes, we characterize the classes of Poisson processes that render the particles’ positions—at all times, and invariantly with respect to the wave processes—statistically identical to their initial positions. These Poisson processes are termed ‘super-stable’ and facilitate the generalization of the notion of stationary distributions far beyond the realm of Markov dynamics.

  8. Periodicity of the stable isotopes

    CERN Document Server

    Boeyens, J C A

    2003-01-01

    It is demonstrated that all stable (non-radioactive) isotopes are formally interrelated as the products of systematically adding alpha particles to four elementary units. The region of stability against radioactive decay is shown to obey a general trend based on number theory and contains the periodic law of the elements as a special case. This general law restricts the number of what may be considered as natural elements to 100 and is based on a proton:neutron ratio that matches the golden ratio, characteristic of biological and crystal growth structures. Different forms of the periodic table inferred at other proton:neutron ratios indicate that the electronic configuration of atoms is variable and may be a function of environmental pressure. Cosmic consequences of this postulate are examined. (author)

  9. Stable massive particles at colliders

    Energy Technology Data Exchange (ETDEWEB)

    Fairbairn, M.; /Stockholm U.; Kraan, A.C.; /Pennsylvania U.; Milstead, D.A.; /Stockholm U.; Sjostrand, T.; /Lund U.; Skands, P.; /Fermilab; Sloan, T.; /Lancaster U.

    2006-11-01

    We review the theoretical motivations and experimental status of searches for stable massive particles (SMPs) which could be sufficiently long-lived as to be directly detected at collider experiments. The discovery of such particles would address a number of important questions in modern physics including the origin and composition of dark matter in the universe and the unification of the fundamental forces. This review describes the techniques used in SMP-searches at collider experiments and the limits so far obtained on the production of SMPs which possess various colour, electric and magnetic charge quantum numbers. We also describe theoretical scenarios which predict SMPs, the phenomenology needed to model their production at colliders and interactions with matter. In addition, the interplay between collider searches and open questions in cosmology such as dark matter composition are addressed.

  10. The Myopic Stable Set for Social Environments

    NARCIS (Netherlands)

    Demuynck, Thomas; Herings, P. Jean-Jacques; Saulle, Riccardo; Seel, Christian

    2017-01-01

    We introduce a new solution concept for models of coalition formation, called the myopic stable set. The myopic stable set is defined for a very general class of social environments and allows for an infinite state space. We show that the myopic stable set exists and is non-empty. Under minor

  11. Effectiveness and risks of stable iodine prophylaxis

    International Nuclear Information System (INIS)

    Waight, P.J.

    1995-01-01

    The factors upon which the efficacy of stable iodine prophylaxis depends are reviewed, with particular reference to the dose of stable iodine, the timing of the dose, the influence of dietary iodine and the impact of the other prospective actions. The risks of stable iodine ingestion are estimated, and their application to the principle of Justification in outlined. (Author)

  12. Temperature and Humidity Control in Livestock Stables

    DEFF Research Database (Denmark)

    Hansen, Michael; Andersen, Palle; Nielsen, Kirsten M.

    2010-01-01

    The paper describes temperature and humidity control of a livestock stable. It is important to have a correct air flow pattern in the livestock stable in order to achieve proper temperature and humidity control as well as to avoid draught. In the investigated livestock stable the air flow...

  13. Durability of template-free Fe-N-C foams for electrochemical oxygen reduction in alkaline solution

    Science.gov (United States)

    Mufundirwa, Albert; Harrington, George F.; Smid, Břetislav; Cunning, Benjamin V.; Sasaki, Kazunari; Lyth, Stephen M.

    2018-01-01

    Due to the high cost and limited availability of platinum, the development of non-platinum-group metals (non-PGM) catalysts is of paramount importance. A promising alternative to Pt are Fe-N-C-based materials. Here we present the synthesis, characterization and electrochemistry of a template-free nitrogen-doped carbon foam, impregnated with iron. This low-cost and gram-scale method results in materials with micron-scale pore size and large surface area (1600 m2g-1). When applied as an oxygen reduction reaction (ORR) electrocatalyst in alkaline solution, the Fe-N-C foams display extremely high initial activity, slightly out-performing commercially available non-PGM catalysts (NCP-2000, Pajarito Powder). The load-cycle durability in alkaline solution is investigated, and the performance steadily degrades over 60,000 potential cycles, whilst the commercial catalyst is remarkably stable. The post-operation catalyst microstructure is elucidated by transmission electron microscopy (TEM), to provide insight into the degradation processes. The resulting images suggest that potential cycling leads to leaching of atomically dispersed Fe-N2/4 sites in all the catalysts, whereas encapsulated iron nanoparticles are protected.

  14. Influence of ionic strength and OH(-) ion concentration on the Cu(II) complex formation with EDTA in alkaline solutions.

    Science.gov (United States)

    Norkus, E; Vaskelis, A; Zakaite, I

    1996-03-01

    D.c. polarographic data show that the complex formation of copper ions with EDTA depends markedly on the ionic strength of the solution at pH 8-10. This is primarily associated with the dependence of the fourth deprotonization constant of EDTA on the solution ionic strength: when it increases from 0.4 to 3.4, the pK(a4) value decreases from 9.5 to 8.2. According to polarographic and spectrophotometric data the degree of Cu(II) complexation increases at pH>10 due to transformation of the complex CuY(2-) to the more stable CuY(OH)(3-) (Y(4-), a fully deprotonized anion of EDTA), but it decreases with increase in alkalinity in a highly alkaline solution (pH>13.5). The latter result could be explained by the decrease in the EDTA anion activity. The calculated values of the activity coefficient are lower than 0.05 at pH>14.

  15. 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

  16. Distributions of alkali metals, alkaline earth metals and halogens in cabbage leaves

    International Nuclear Information System (INIS)

    Tsukada, Hirofumi; Takeda, Akira; Hasegawa, Hidenao

    2007-01-01

    The distributions of stable elements in plant components provide useful information for understanding the behavior of radionuclides in plants. An entire cabbage plant sample was collected from an experimental field, and the distributions of alkali metals (K, Rb and Cs), alkaline earth metals (Ca, Sr and Ba) and halogens (Cl and I) were determined for cabbage leaves at different positions. The concentration of Cs in outer (older) cabbage leaves was higher than that in inner (younger) leaves, but the distributions of K and Rb concentrations were relatively similar in cabbage leaves, independent of leaf positions. The concentration of Sr in older cabbage leaves was one order of magnitude higher than that in younger leaves. The distributions of Ca, Ba and Sr concentrations in the plant followed a similar pattern. The concentrations of halogens were also very rich in the outer leaves. The percentage distributions of Cs, Sr, Cl and I in the inedible (extreme outer) leaves were 77, 91, 93 and 96% of the total content in the leaf part, respectively. These results show that the inedible plant components are important for understanding the transfer of the radioactive Cs, Sr Cl and I in soil-plant systems. (author)

  17. 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

  18. Composition, diagenetic transformation and alkalinity potential of oil shale ash sediments

    International Nuclear Information System (INIS)

    Motlep, Riho; Sild, Terje; Puura, Erik; Kirsimaee, Kalle

    2010-01-01

    Oil shale is a primary fuel in the Estonian energy sector. After combustion 45-48% of the oil shale is left over as ash, producing about 5-7 Mt of ash, which is deposited on ash plateaus annually almost without any reuse. This study focuses on oil shale ash plateau sediment mineralogy, its hydration and diagenetic transformations, a study that has not been addressed. Oil shale ash wastes are considered as the biggest pollution sources in Estonia and thus determining the composition and properties of oil shale ash sediment are important to assess its environmental implications and also its possible reusability. A study of fresh ash and drillcore samples from ash plateau sediment was conducted by X-ray diffractometry and scanning electron microscopy. The oil shale is highly calcareous, and the ash that remains after combustion is derived from the decomposition of carbonate minerals. It is rich in lime and anhydrite that are unstable phases under hydrous conditions. These processes and the diagenetic alteration of other phases determine the composition of the plateau sediment. Dominant phases in the ash are hydration and associated transformation products: calcite, ettringite, portlandite and hydrocalumite. The prevailing mineral phases (portlandite, ettringite) cause highly alkaline leachates, pH 12-13. Neutralization of these leachates under natural conditions, by rainwater leaching/neutralization and slow transformation (e.g. carbonation) of the aforementioned unstable phases into more stable forms, takes, at best, hundreds or even hundreds of thousands of years.

  19. Composition, diagenetic transformation and alkalinity potential of oil shale ash sediments

    Energy Technology Data Exchange (ETDEWEB)

    Motlep, Riho, E-mail: riho.motlep@ut.ee [Department of Geology, University of Tartu, Ravila 14A, 50411 Tartu (Estonia); Sild, Terje, E-mail: terje.sild@maaamet.ee [Estonian Land Board, Mustamaee tee 51, 10621 Tallinn (Estonia); Puura, Erik, E-mail: erik.puura@ut.ee [Institute of Technology, University of Tartu, Nooruse 1, 50411 Tartu (Estonia); Kirsimaee, Kalle, E-mail: kalle.kirsimae@ut.ee [Department of Geology, University of Tartu, Ravila 14A, 50411 Tartu (Estonia)

    2010-12-15

    Oil shale is a primary fuel in the Estonian energy sector. After combustion 45-48% of the oil shale is left over as ash, producing about 5-7 Mt of ash, which is deposited on ash plateaus annually almost without any reuse. This study focuses on oil shale ash plateau sediment mineralogy, its hydration and diagenetic transformations, a study that has not been addressed. Oil shale ash wastes are considered as the biggest pollution sources in Estonia and thus determining the composition and properties of oil shale ash sediment are important to assess its environmental implications and also its possible reusability. A study of fresh ash and drillcore samples from ash plateau sediment was conducted by X-ray diffractometry and scanning electron microscopy. The oil shale is highly calcareous, and the ash that remains after combustion is derived from the decomposition of carbonate minerals. It is rich in lime and anhydrite that are unstable phases under hydrous conditions. These processes and the diagenetic alteration of other phases determine the composition of the plateau sediment. Dominant phases in the ash are hydration and associated transformation products: calcite, ettringite, portlandite and hydrocalumite. The prevailing mineral phases (portlandite, ettringite) cause highly alkaline leachates, pH 12-13. Neutralization of these leachates under natural conditions, by rainwater leaching/neutralization and slow transformation (e.g. carbonation) of the aforementioned unstable phases into more stable forms, takes, at best, hundreds or even hundreds of thousands of years.

  20. Biochemical Characterization of An Arginine-Specific Alkaline Trypsin from Bacillus licheniformis.

    Science.gov (United States)

    Gong, Jin-Song; Li, Wei; Zhang, Dan-Dan; Xie, Min-Feng; Yang, Biao; Zhang, Rong-Xian; Li, Heng; Lu, Zhen-Ming; Xu, Zheng-Hong; Shi, Jin-Song

    2015-12-17

    In the present study, we isolated a trypsin-producing strain DMN6 from the leather waste and identified it as Bacillus licheniformis through a two-step screening strategy. The trypsin activity was increased up to 140 from 20 U/mL through culture optimization. The enzyme was purified to electrophoretic homogeneity with a molecular mass of 44 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and the specific activity of purified enzyme is 350 U/mg with Nα-Benzoyl-L-arginine ethylester as the substrate. The optimum temperature and pH for the trypsin are 65 °C and pH 9.0, respectively. Also, the enzyme can be significantly activated by Ba(2+). This enzyme is relatively stable in alkaline environment and displays excellent activity at low temperatures. It could retain over 95% of enzyme activity after 180 min of incubation at 45 °C. The distinguished activity under low temperature and prominent stability enhance its catalytic potential. In the current work, the open reading frame was obtained with a length of 1371 nucleotides that encoded a protein of 456 amino acids. These data would warrant the B. licheniformis trypsin as a promising candidate for catalytic application in collagen preparation and leather bating through further protein engineering.

  1. Highly Zeolite-Loaded Polyvinyl Alcohol Composite Membranes for Alkaline Fuel-Cell Electrolytes

    Directory of Open Access Journals (Sweden)

    Po-Ya Hsu

    2018-01-01

    Full Text Available Having a secure and stable energy supply is a top priority for the global community. Fuel-cell technology is recognized as a promising electrical energy generation system for the twenty-first century. Polyvinyl alcohol/zeolitic imidazolate framework-8 (PVA/ZIF-8 composite membranes were successfully prepared in this work from direct ZIF-8 suspension solution (0–45.4 wt % and PVA mixing to prevent filler aggregation for direct methanol alkaline fuel cells (DMAFCs. The ZIF-8 fillers were chosen for the appropriate cavity size as a screening aid to allow water and suppress methanol transport. Increased ionic conductivities and suppressed methanol permeabilities were achieved for the PVA/40.5% ZIF-8 composites, compared to other samples. A high power density of 173.2 mW cm−2 was achieved using a KOH-doped PVA/40.5% ZIF-8 membrane in a DMAFC at 60 °C with 1–2 mg cm−2 catalyst loads. As the filler content was raised beyond 45.4 wt %, adverse effects resulted and the DMAFC performance (144.9 mW cm−2 was not improved further. Therefore, the optimal ZIF-8 content was approximately 40.5 wt % in the polymeric matrix. The specific power output was higher (58 mW mg−1 than most membranes reported in the literature (3–18 mW mg−1.

  2. 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.

  3. Biochemical Characterization of An Arginine-Specific Alkaline Trypsin from Bacillus licheniformis

    Directory of Open Access Journals (Sweden)

    Jin-Song Gong

    2015-12-01

    Full Text Available In the present study, we isolated a trypsin-producing strain DMN6 from the leather waste and identified it as Bacillus licheniformis through a two-step screening strategy. The trypsin activity was increased up to 140 from 20 U/mL through culture optimization. The enzyme was purified to electrophoretic homogeneity with a molecular mass of 44 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and the specific activity of purified enzyme is 350 U/mg with Nα-Benzoyl-l-arginine ethylester as the substrate. The optimum temperature and pH for the trypsin are 65 °C and pH 9.0, respectively. Also, the enzyme can be significantly activated by Ba2+. This enzyme is relatively stable in alkaline environment and displays excellent activity at low temperatures. It could retain over 95% of enzyme activity after 180 min of incubation at 45 °C. The distinguished activity under low temperature and prominent stability enhance its catalytic potential. In the current work, the open reading frame was obtained with a length of 1371 nucleotides that encoded a protein of 456 amino acids. These data would warrant the B. licheniformis trypsin as a promising candidate for catalytic application in collagen preparation and leather bating through further protein engineering.

  4. Microbial diversity in ikaite tufa columns: an alkaline, cold ecological niche in Greenland.

    Science.gov (United States)

    Stougaard, Peter; Jørgensen, Flemming; Johnsen, Mads G; Hansen, Ole C

    2002-08-01

    Ikaite tufa columns from the Ikka Fjord in south-western Greenland constitute a natural, stable environment at low temperature and with a pH ranging from neutral at the exterior to very alkaline (pH 10.4) at the interior of the column. Phylogenetic analysis of culturable organisms revealed ten different isolates representing three of the major bacterial divisions. Nine of the isolates showed 94-99% similarity to known sequences, whereas one isolate displayed a low degree of similarity (less than 90%) to a Cyclobacterium species. Seven of the isolates were shown to be cold active alkaliphiles, whereas three isolates showed optimal growth at neutral pH. Phylogenetic analysis of DNA isolated directly from the ikaite material demonstrated the presence of a microbial flora more diverse than the culturable isolates. Whereas approximately half of the phylotypes showed 90-99% similarity to known meso- or thermophilic alkaliphiles, the rest of the sequences displayed less than 90% similarity when compared to known 16S rRNA gene sequences in databases. Thus, in the present paper, we demonstrate that ikaite columns that host a specialized macroscopic flora and fauna also contain a unique, cold active, alkaliphilic microflora.

  5. 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

  6. 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

  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. 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)

  9. 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)

  10. 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...

  11. 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.

  12. 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.)

  13. 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)

  14. 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.

  15. 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

  16. 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....

  17. 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

  18. 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.)

  19. 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.

  20. In-liquid Plasma. A stable light source for advanced oxidation processes in environmental remediation

    Science.gov (United States)

    Tsuchida, Akihiro; Shimamura, Takeshi; Sawada, Seiya; Sato, Susumu; Serpone, Nick; Horikoshi, Satoshi

    2018-06-01

    A microwave-inspired device that generates stable in-liquid plasma (LP) in aqueous media and emits narrow light emission lines at 280-320 nm, 660 nm and 780 nm is examined as a light source capable of driving photochemical reactions and advanced oxidation processes in wastewater treatments. The microwave-driven lighting efficiency was improved by decompressing the inside of the reaction vessel, which resulted in lowering the incident power of the microwaves and suppressed the deterioration of the microwave irradiation antenna. This protocol made it possible to generate continuous stable plasma in water. Evaluation of the LP device was carried out by revisiting the decomposition of 1,4-dioxane in aqueous media against the use of such other conventional water treatment processes as (i) UV irradiation alone, (ii) TiO2-assisted photocatalysis with UV irradiation (UV/TiO2), (iii) oxidation with sodium hypochlorite (NaClO), and (iv) UV-assisted decomposition in the presence of NaClO (UV/NaClO). The in-liquid plasma technique proved superior to these four other methods. The influence of pH on the LP protocol was ascertained through experiments in acidified (HCl and H2SO4) and alkaline (NaOH and KOH) aqueous media. Except for H2SO4, decomposition of 1,4-dioxane was enhanced in both acidic and alkaline media.

  1. Separating nano graphene oxide from the residual strong-acid filtrate of the modified Hummers method with alkaline solution

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Xuebing, E-mail: xuebinghu2010@gmail.com [Key Laboratory of Inorganic Membrane, Jingdezhen Ceramic Institute, Jingdezhen 333001 (China); Key Laboratory of Inorganic Coating Materials, Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai 201800 (China); Yu, Yun, E-mail: yunyush@mail.sic.ac.cn [Key Laboratory of Inorganic Coating Materials, Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai 201800 (China); Wang, Yongqing; Zhou, Jianer [Key Laboratory of Inorganic Membrane, Jingdezhen Ceramic Institute, Jingdezhen 333001 (China); Song, Lixin [Key Laboratory of Inorganic Coating Materials, Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai 201800 (China)

    2015-02-28

    Graphical abstract: By adding an alkaline (NaOH or KOH) solution, the unprecipitated nano graphene oxide undergoes fast aggregation from the residual strong-acid filtrate of the modified Hummers method and forms the stable floccules when the pH value of the filtrate is about 1.7. The acid–base interaction with the surface functional groups of the carbon layers plays a role in the aggregation of the unprecipitated nano graphene oxide. - Highlights: • The novel and high-efficient method for separating graphene oxide was showed. • Graphene oxide undergoes aggregation and forms the floccules when pH value is ∼1.7. • The acid–base interaction plays a role in the aggregation of graphene oxide. - Abstract: In the modified Hummers method for preparing graphene oxide, the yellow slurry can be obtained. After filtering through a quantitative filter paper, the strong-acid filtrate containing the unprecipitated nano graphene oxide was gained. The corresponding filtrate was added gradually with an alkaline (NaOH or KOH) solution at room temperature. The unprecipitated nano graphene oxide could undergo fast aggregation when the pH value of the filtrate was about 1.7 and formed the stable floccules. X-ray diffraction analysis shows the dominant peak of the floccules is about 11°, which accords to the peak of graphene oxide. Spectra of X-ray photoelectron spectroscopy confirm the presence in the floccules of an abundance of oxygen functional groups and the purified graphene oxide floccules can be obtained. Atomic force microscopy measurement shows the graphene oxide floccules consists of sheet-like objects, mostly containing only a few layers (about 5 layers). Zeta potential analysis demonstrates the surface charge of the graphene oxide is pH-sensitive and its isoelectric point is ∼1.7. The flocculation mechanism of graphene oxide ascribes to the acid–base interaction with the surface functional groups of the carbon layers.

  2. Moltex Energy's stable salt reactors

    International Nuclear Information System (INIS)

    O'Sullivan, R.; Laurie, J.

    2016-01-01

    A stable salt reactor is a molten salt reactor in which the molten fuel salt is contained in fuel rods. This concept was invented in 1951 and re-discovered and improved recently by Moltex Energy Company. The main advantage of using molten salt fuel is that the 2 problematic fission products cesium and iodine do not exist in gaseous form but rather in a form of a salt that present no danger in case of accident. Another advantage is the strongly negative temperature coefficient for reactivity which means the reactor self-regulates. The feasibility studies have been performed on a molten salt fuel composed of sodium chloride and plutonium/uranium/lanthanide/actinide trichloride. The coolant fluid is a mix of sodium and zirconium fluoride salts that will need low flow rates. The addition of 1 mol% of metal zirconium to the coolant fluid reduces the risk of corrosion with standard steels and the addition of 2% of hafnium reduces the neutron dose. The temperature of the coolant is expected to reach 650 Celsius degrees at the exit of the core. This reactor is designed to be modular and it will be able to burn actinides. (A.C.)

  3. Rare stable isotopes in meteorites

    International Nuclear Information System (INIS)

    Wilson, G.C.

    1981-01-01

    Secondary Ion Mass Spectrometry (SIMS) using accelerators has been applied with success to cosmic ray exposure ages and terrestrial residence times of meteorites by measuring cosmogenic nuclides of Be, Cl, and I. It is proposed to complement this work with experiments on rare stable isotopes, in the hope of setting constraints on the processes of solar nebula/meteoritic formation. The relevant species can be classified as: a) daughter products of extinct nuclides (halflife less than or equal to 2 x 10 8 y) -chronology of the early solar system; b) products of high temperature astrophysical processes - different components incorporated into the solar nebula; and c) products of relatively low temperature processes, stellar winds and cosmic ray reactions - early solar system radiation history. The use of micron-scale primary ion beams will allow detailed sampling of phases within meteorites. Strategies of charge-state selection, molecular disintegration and detection should bring a new set of targets within analytical range. The developing accelerator field is compared to existing (keV energy) ion microprobes

  4. Stable piecewise polynomial vector fields

    Directory of Open Access Journals (Sweden)

    Claudio Pessoa

    2012-09-01

    Full Text Available Let $N={y>0}$ and $S={y<0}$ be the semi-planes of $mathbb{R}^2$ having as common boundary the line $D={y=0}$. Let $X$ and $Y$ be polynomial vector fields defined in $N$ and $S$, respectively, leading to a discontinuous piecewise polynomial vector field $Z=(X,Y$. This work pursues the stability and the transition analysis of solutions of $Z$ between $N$ and $S$, started by Filippov (1988 and Kozlova (1984 and reformulated by Sotomayor-Teixeira (1995 in terms of the regularization method. This method consists in analyzing a one parameter family of continuous vector fields $Z_{epsilon}$, defined by averaging $X$ and $Y$. This family approaches $Z$ when the parameter goes to zero. The results of Sotomayor-Teixeira and Sotomayor-Machado (2002 providing conditions on $(X,Y$ for the regularized vector fields to be structurally stable on planar compact connected regions are extended to discontinuous piecewise polynomial vector fields on $mathbb{R}^2$. Pertinent genericity results for vector fields satisfying the above stability conditions are also extended to the present case. A procedure for the study of discontinuous piecewise vector fields at infinity through a compactification is proposed here.

  5. Stable Structures for Distributed Applications

    Directory of Open Access Journals (Sweden)

    Eugen DUMITRASCU

    2008-01-01

    Full Text Available For distributed applications, we define the linear, tree and graph structure types with different variants and modalities to aggregate them. The distributed applications have assigned structures that through their characteristics influence the costs of stages for developing cycle and the costs for exploitation, transferred to each user. We also present the quality characteristics of a structure for a stable application, which is focused on stability characteristic. For that characteristic we define the estimated measure indicators for a level. The influence of the factors of stability and the ways for increasing it are thus identified, and at the same time the costs of development stages, the costs of usage and the costs of maintenance to be keep on between limits that assure the global efficiency of application. It is presented the base aspects for distributed applications: definition, peculiarities and importance. The aspects for the development cycle of distributed application are detailed. In this article, we alongside give the mechanisms for building the defined structures and analyze the complexity of the defined structures for a distributed application of a virtual store.

  6. 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)

  7. 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

  8. 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.

  9. 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...

  10. 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

  11. 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.

  12. 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...

  13. 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...

  14. 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.

  15. 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

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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)

  1. 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.

  2. Purification and biochemical characterization of a serine alkaline ...

    African Journals Online (AJOL)

    The protease was stable in 0.5% SDS and retained 70.3% of its initial activity after 1 h of incubation. It was active in the presence of 3% Triton X-100 with 100% activity and stable towards oxidizing agent with 69.2% activity in the presence of 1% H2O2. The enzyme showed excellent compatibility with commercial detergents ...

  3. Advanced thermally stable jet fuels

    Energy Technology Data Exchange (ETDEWEB)

    Schobert, H.H.

    1999-01-31

    The Pennsylvania State University program in advanced thermally stable coal-based jet fuels has five broad objectives: (1) Development of mechanisms of degradation and solids formation; (2) Quantitative measurement of growth of sub-micrometer and micrometer-sized particles suspended in fuels during thermal stressing; (3) Characterization of carbonaceous deposits by various instrumental and microscopic methods; (4) Elucidation of the role of additives in retarding the formation of carbonaceous solids; (5) Assessment of the potential of production of high yields of cycloalkanes by direct liquefaction of coal. Future high-Mach aircraft will place severe thermal demands on jet fuels, requiring the development of novel, hybrid fuel mixtures capable of withstanding temperatures in the range of 400--500 C. In the new aircraft, jet fuel will serve as both an energy source and a heat sink for cooling the airframe, engine, and system components. The ultimate development of such advanced fuels requires a thorough understanding of the thermal decomposition behavior of jet fuels under supercritical conditions. Considering that jet fuels consist of hundreds of compounds, this task must begin with a study of the thermal degradation behavior of select model compounds under supercritical conditions. The research performed by The Pennsylvania State University was focused on five major tasks that reflect the objectives stated above: Task 1: Investigation of the Quantitative Degradation of Fuels; Task 2: Investigation of Incipient Deposition; Task 3: Characterization of Solid Gums, Sediments, and Carbonaceous Deposits; Task 4: Coal-Based Fuel Stabilization Studies; and Task 5: Exploratory Studies on the Direct Conversion of Coal to High Quality Jet Fuels. The major findings of each of these tasks are presented in this executive summary. A description of the sub-tasks performed under each of these tasks and the findings of those studies are provided in the remainder of this volume

  4. Full-scale production of VFAs from sewage sludge by anaerobic alkaline fermentation to improve biological nutrients removal in domestic wastewater.

    Science.gov (United States)

    Liu, He; Han, Peng; Liu, Hongbo; Zhou, Guangjie; Fu, Bo; Zheng, Zhiyong

    2018-07-01

    A full-scale project of thermal-alkaline pretreatment and alkaline fermentation of sewage sludge was built to produce volatile fatty acids (VFAs) which was then used as external carbon source for improving biological nitrogen and phosphorus removals (BNPR) in wastewater plant. Results showed this project had efficient and stable performances in VFA production, sludge reduce and BNPR. Hydrolysis rate in pretreatment, VFAs yield in fermentation and total VS reduction reached 68.7%, 261.32 mg COD/g VSS and 54.19%, respectively. Moreover, fermentation liquid with VFA presented similar efficiency as acetic acid in enhancing BNPR, obtaining removal efficiencies of nitrogen and phosphorus up to 72.39% and 89.65%, respectively. Finally, the project also presented greater economic advantage than traditional processes, and the net profits for VFAs and biogas productions are 9.12 and 3.71 USD/m 3 sludge, respectively. Long-term operation indicated that anaerobic alkaline fermentation for VFAs production is technically and economically feasible for sludge carbon recovery. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. Post-irradiation analysis of an ISOLDE lead-bismuth target: Stable and long-lived noble gas nuclides

    Energy Technology Data Exchange (ETDEWEB)

    Leya, I., E-mail: Ingo.Leya@space.unibe.ch [University of Bern, Space Science and Planetology, Bern (Switzerland); Grimberg, A. [University of Bern, Space Science and Planetology, Bern (Switzerland); Isotope Geochemistry, ETH Zürich, Zürich (Switzerland); David, J.-C. [CEA/Saclay, Irfu/SPhN, 91191 Gif-sur-Yvette, Cedex (France); Schumann, D.; Neuhausen, J. [Paul Scherrer Institut, Villigen (Switzerland); Zanini, L. [Paul Scherrer Institut, Villigen (Switzerland); European Spallation Source ESS AB, P.O. Box 117, SE-22100 Lund (Sweden); Noah, E. [University of Geneva, Département de Physique Nucléaire et Corpusculaire, Geneve (Switzerland)

    2016-07-15

    We measured the isotopic concentrations of long-lived and stable He, Ne, Ar, Kr, and Xe isotopes in a sample from a lead-bismuth eutectic target irradiated with 1.0 and 1.4 GeV protons. Our data indicate for most noble gases nearly complete release with retention fractions in the range of percent or less. Higher retention fractions result from the decay of long-lived radioactive progenitors from groups 1, 2, or 7 of the periodic table. From the data we can calculate a retention fraction for {sup 3}H of 2–3%. For alkaline metals we find retention fractions of about 10%, 30%, and 50% for Na, Rb, and Cs, respectively. For the alkaline earth metal Ba we found complete retention. Finally, the measured Kr and Xe concentrations indicate that there was some release of the halogens Br and I during and/or after the irradiation.

  6. Population Games, Stable Games, and Passivity

    Directory of Open Access Journals (Sweden)

    Michael J. Fox

    2013-10-01

    Full Text Available The class of “stable games”, introduced by Hofbauer and Sandholm in 2009, has the attractive property of admitting global convergence to equilibria under many evolutionary dynamics. We show that stable games can be identified as a special case of the feedback-system-theoretic notion of a “passive” dynamical system. Motivated by this observation, we develop a notion of passivity for evolutionary dynamics that complements the definition of the class of stable games. Since interconnections of passive dynamical systems exhibit stable behavior, we can make conclusions about passive evolutionary dynamics coupled with stable games. We show how established evolutionary dynamics qualify as passive dynamical systems. Moreover, we exploit the flexibility of the definition of passive dynamical systems to analyze generalizations of stable games and evolutionary dynamics that include forecasting heuristics as well as certain games with memory.

  7. 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.

  8. 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...

  9. 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.

  10. 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...

  11. 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)

  12. 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

  13. 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)

  14. 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...

  15. 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...

  16. 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.

  17. 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.

  18. 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.

  19. 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)

  20. 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.

  1. 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)

  2. 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.

  3. 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.

  4. 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.

  5. 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)

  6. 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)

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. 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)

  12. 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)

  13. 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)

  14. Applications of stable isotopes in clinical pharmacology

    NARCIS (Netherlands)

    Schellekens, Reinout C A; Stellaard, Frans; Woerdenbag, Herman J; Frijlink, Henderik W; Kosterink, Jos G W

    2011-01-01

    This review aims to present an overview of the application of stable isotope technology in clinical pharmacology. Three main categories of stable isotope technology can be distinguished in clinical pharmacology. Firstly, it is applied in the assessment of drug pharmacology to determine the

  15. Stable isotopes and biomarkers in microbial ecology

    NARCIS (Netherlands)

    Boschker, H.T.S.; Middelburg, J.J.

    2002-01-01

    The use of biomarkers in combination with stable isotope analysis is a new approach in microbial ecology and a number of papers on a variety of subjects have appeared. We will first discuss the techniques for analysing stable isotopes in biomarkers, primarily gas chromatography-combustion-isotope

  16. Modelling stable atmospheric boundary layers over snow

    NARCIS (Netherlands)

    Sterk, H.A.M.

    2015-01-01

    Thesis entitled:

    Modelling Stable Atmospheric Boundary Layers over Snow

    H.A.M. Sterk

    Wageningen, 29th of April, 2015

    Summary

    The emphasis of this thesis is on the understanding and forecasting of the Stable Boundary Layer (SBL) over snow-covered surfaces. SBLs

  17. Gas phase thermal diffusion of stable isotopes

    International Nuclear Information System (INIS)

    Eck, C.F.

    1979-01-01

    The separation of stable isotopes at Mound Facility is reviewed from a historical perspective. The historical development of thermal diffusion from a laboratory process to a separation facility that handles all the noble gases is described. In addition, elementary thermal diffusion theory and elementary cascade theory are presented along with a brief review of the uses of stable isotopes

  18. 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

  19. 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...

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. 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)

  5. 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...

  6. 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...

  7. 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 ...

  8. Structure of acid-stable carmine.

    Science.gov (United States)

    Sugimoto, Naoki; Kawasaki, Yoko; Sato, Kyoko; Aoki, Hiromitsu; Ichi, Takahito; Koda, Takatoshi; Yamazaki, Takeshi; Maitani, Tamio

    2002-02-01

    Acid-stable carmine has recently been distributed in the U.S. market because of its good acid stability, but it is not permitted in Japan. We analyzed and determined the structure of the major pigment in acid-stable carmine, in order to establish an analytical method for it. Carminic acid was transformed into a different type of pigment, named acid-stable carmine, through amination when heated in ammonia solution. The features of the structure were clarified using a model compound, purpurin, in which the orientation of hydroxyl groups on the A ring of the anthraquinone skeleton is the same as that of carminic acid. By spectroscopic means and the synthesis of acid-stable carmine and purpurin derivatives, the structure of the major pigment in acid-stable carmine was established as 4-aminocarminic acid, a novel compound.

  9. 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.

  10. 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.

  11. 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...

  12. 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.

  13. 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/

  14. 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

  15. High Iridium concentration of alkaline rocks of Deccan and ...

    Indian Academy of Sciences (India)

    R. Narasimhan, Krishtel eMaging Solutions

    and nine rare-earth elements (REE: La, Ce, Nd ... Rare earth patterns of different samples of car- bonatite ..... Ray J S 1997 Stable and radioisotopic constraints on the evolution of ... volcanism pre-date the Cretaceous/Tertiary transition?; Earth ...

  16. Carbon supported ultrafine gold phosphorus nanoparticles as highly efficient electrocatalyst for alkaline ethanol oxidation reaction

    International Nuclear Information System (INIS)

    Li, Tongfei; Fu, Gengtao; Su, Jiahui; Wang, Yi; Lv, Yinjie; Zou, Xiuyong; Zhu, Xiaoshu; Xu, Lin; Sun, Dongmei; Tang, Yawen

    2017-01-01

    Graphical abstract: We develop a new kind of carbon supported gold-phosphorus (Au-P/C) electrocatalyst by a facile and novel phosphorus reduction method, and demonstrate the Au-P/C is a highly active and stable electrocatalyst for the ethanol oxidation reaction. - Highlights: • Au-P/C catalyst is synthesized by a facile and novel white-phosphorus reduce method. • AuP particles with ultrafine particle-size are uniformly dispersed on carbon support. • Au-P/C catalyst exhibits much higher content of P 0 than reported metal/P catalysts. • Au-P/C catalysts show excellent catalytic properties for ethanol oxidation reaction. - Abstract: Herein, we develop a new kind of carbon supported gold-phosphorus (Au-P/C) electrocatalyst for the alkaline ethanol oxidation reaction (EOR). The Au-P/C catalysts with different Au/P ratio (i.e., AuP/C, Au 3 P 2 /C and Au 4 P 3 /C) can be obtained by a facile and novel hot-reflux method with white phosphorus (P 4 ) as reductant and ethanol as solvent. The crystal structure, composition and particle-size of the Au-P/C catalysts are investigated by X-ray diffraction (XRD), Energy Dispersive Spectrometer (EDS), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS), etc. The results demonstrate that Au-P/C catalysts present an alloy phase with the high content of P, ultrafine particle-size and high dispersity on carbon support, which results in excellent electrocatalytic activity and stability towards the EOR compared with that of the free-phosphorus Au/C catalyst. In addition, among the various Au-P/C catalysts with different Au/P ratio, the AuP/C sample exhibits the best electrocatalytic performance in comparison with other Au 3 P 2 /C and Au 4 P 3 /C samples.

  17. Production and some properties of crude alkaline proteases of indigenous Central Amazonian rhizobia strains

    Directory of Open Access Journals (Sweden)

    Arlem Nascimento de Oliveira

    2010-10-01

    Full Text Available Two rhizobia strains isolated from soils of the Central Amazonian floodplain produced appreciable quantities of crude alkaline protease extracts with inexpensive carbon and nitrogen sources. These protease crude extracts were optimally active at pH 9.0-11.0. The optimum temperatures were 35 ºC for Rhizobium sp. strain R-986 and 55 ºC for Bradyrhizobium sp. strain R-993. Protease activities in the crude extracts were enhanced in the presence of 5 mM metal ions, such as Na+, Ca2+, Mg2+ and Mn2+. Rhizobia proteases were strongly inhibited by PMSF, a serine-protease inhibitor. The enzymes were active in the presence of surfactants (SDS and Triton X-100 and stable in oxidizing (H2O2 and reducing agents (β-mercaptoethanol, and organic solvents (acetone, hexane, methanol, 1-propanol and toluene.Duas estirpes de rizóbia isoladas de solos de várzea da Amazônia Central produziram grandes quantidades de proteases alcalinas extracelulares, usando fontes baratas de carbono e nitrogênio. Os extratos brutos de proteases foram ativos em pH 9,0-11,0. As temperaturas ótimas foram de 35 ºC para a enzima do Rhizobium R-986 e de 55 ºC para a do Bradyrhizobium R-993. As atividades proteolíticas aumentaram na presença de 5 mM dos íons Na+, Ca2+ , Mg2+ e Mn2+ . As proteases secretadas pelos rizóbios foram fortemente inibidas por PMSF, um inibidor de serina protease. As enzimas foram ativas na presença de surfactantes (SDS e Triton X-100, e estáveis na presença de agentes oxidantes (H2O2 e redutores (β-mercaptoetanol e solventes orgânicos (acetona, hexano, metanol, 1-propanol e tolueno.

  18. Ballooning stable high beta tokamak equilibria

    International Nuclear Information System (INIS)

    Tuda, Takashi; Azumi, Masafumi; Kurita, Gen-ichi; Takizuka, Tomonori; Takeda, Tatsuoki

    1981-04-01

    The second stable regime of ballooning modes is numerically studied by using the two-dimensional tokamak transport code with the ballooning stability code. Using the simple FCT heating scheme, we find that the plasma can locally enter this second stable regime. And we obtained equilibria with fairly high beta (β -- 23%) stable against ballooning modes in a whole plasma region, by taking into account of finite thermal diffusion due to unstable ballooning modes. These results show that a tokamak fusion reactor can operate in a high beta state, which is economically favourable. (author)

  19. Development of stable isotope manufacturing in Russia

    International Nuclear Information System (INIS)

    Pokidychev, A.; Pokidycheva, M.

    1999-01-01

    For the past 25 years, Russia has relied heavily on the electromagnetic separation process for the production of middle and heavy mass stable isotopes. The separation of most light isotopes had been centered in Georgia which, after the collapse of the USSR, left Russia without this capability. In the mid-1970s, development of centrifuge technology for the separation of stable isotopes was begun. Alternative techniques such as laser separation, physical-chemical methods, and ion cyclotron resonance have also been investigated. Economic considerations have played a major role in the development and current status of the stable isotope enrichment capabilities of Russia

  20. Sensitivity analysis of alkaline plume modelling: influence of mineralogy

    International Nuclear Information System (INIS)

    Gaboreau, S.; Claret, F.; Marty, N.; Burnol, A.; Tournassat, C.; Gaucher, E.C.; Munier, I.; Michau, N.; Cochepin, B.

    2010-01-01

    Document available in extended abstract form only. In the context of a disposal facility for radioactive waste in clayey geological formation, an important modelling effort has been carried out in order to predict the time evolution of interacting cement based (concrete or cement) and clay (argillites and bentonite) materials. The high number of modelling input parameters associated with non negligible uncertainties makes often difficult the interpretation of modelling results. As a consequence, it is necessary to carry out sensitivity analysis on main modelling parameters. In a recent study, Marty et al. (2009) could demonstrate that numerical mesh refinement and consideration of dissolution/precipitation kinetics have a marked effect on (i) the time necessary to numerically clog the initial porosity and (ii) on the final mineral assemblage at the interface. On the contrary, these input parameters have little effect on the extension of the alkaline pH plume. In the present study, we propose to investigate the effects of the considered initial mineralogy on the principal simulation outputs: (1) the extension of the high pH plume, (2) the time to clog the porosity and (3) the alteration front in the clay barrier (extension and nature of mineralogy changes). This was done through sensitivity analysis on both concrete composition and clay mineralogical assemblies since in most published studies, authors considered either only one composition per materials or simplified mineralogy in order to facilitate or to reduce their calculation times. 1D Cartesian reactive transport models were run in order to point out the importance of (1) the crystallinity of concrete phases, (2) the type of clayey materials and (3) the choice of secondary phases that are allowed to precipitate during calculations. Two concrete materials with either nanocrystalline or crystalline phases were simulated in contact with two clayey materials (smectite MX80 or Callovo- Oxfordian argillites). Both

  1. Combined (alkaline+ultrasonic) pretreatment effect on sewage sludge disintegration.

    Science.gov (United States)

    Kim, Dong-Hoon; Jeong, Emma; Oh, Sae-Eun; Shin, Hang-Sik

    2010-05-01

    The individual effects of alkaline (pH 8-13) and ultrasonic (3750-45,000kJ/kg TS) pretreatments on the disintegration of sewage sludge were separately tested, and then the effect of combining these two methods at different intensity levels was investigated using response surface methodology (RSM). In the combined pretreatment, ultrasonic treatment was applied to the alkali-pretreated sludge. While the solubilization (SCOD/TCOD) increase was limited to 50% in individual pretreatments, it reached 70% in combined pretreatment, and the results clearly showed that preconditioning of sludge at high pH levels played a crucial role in enhancing the disintegration efficiency of the subsequent ultrasonic pretreatment. By applying regression analysis, the disintegration degree (DD) was fitted based on the actual value to a second order polynomial equation: Y=-172.44+29.82X(1)+5.30x10(-3)X(2)-7.53x10(-5)X(1)X(2)-1.10X(1)(2)-1.043x10(-7)X(2)(2), where X(1), X(2), and Y are pH, specific energy input (kJ/kg TS), and DD, respectively. In a 2D contour plot describing the tendency of DD with respect to pH and specific energy input, it was clear that DD increased as pH increased, but it seemed that DD decreased when the specific energy input exceeded about 20,000kJ/kg TS. This phenomenon tells us that there exists a certain point where additional energy input is ineffective in achieving further disintegration. A synergetic disintegration effect was also found in the combined pretreatment, with lower specific energy input in ultrasonic pretreatment yielding higher synergetic effect. Finally, in order to see the combined pretreatment effect in continuous operation, the sludge pretreated with low intensity alkaline (pH 9)/ultrasonic (7500kJ/kg TS) treatment was fed to a 3 L of anaerobic sequencing batch reactor after 70 days of control operation. CH(4) production yield significantly increased from 81.9+/-4.5mL CH(4)/g COD(added) to 127.3+/-5.0mL CH(4)/g COD(added) by pretreatment, and

  2. A review on alkaline activation: new analytical perspectives

    Directory of Open Access Journals (Sweden)

    Palomo, A.

    2014-09-01

    Full Text Available For many years now the idea of including alkalis in a Portland cement matrix has been regarded as a daft or inexcusably erroneous proposition: despite its absurdity, that opinion has been widely accepted as a basic premise by the scientific and technical community working in the area of the chemistry of cement. In 1957 Glukhovsky proposed a working hypothesis in which he established a close relationship between alkalis and cementitious materials. That hypothesis has become consolidated and has served as a basis for developing a new type of binders, initially called “alkaline cements”. The present paper reviews the most significant theoretical interpretations of the role played by alkalis in the formation of the “stony” structure of cement. It ends with a broad overview of the versatility of this type of materials for industrial applications and a discussion of the possibility of building on the existing legislation to meet the need for the future regulation of alkaline cement and concrete manufacture.Hace algunos años, la sola idea de la presencia de álcalis en una matriz de cemento Portland se consideraba casi como una aberración, o como un error imperdonable; convirtiéndose en un postulado básico (absurdo ampliamente aceptado por la comunidad científica y técnica vinculada a la química de los cementos. En 1957 Glukhovsky propuso una hipótesis en la que se establecía una estrecha relación entre los álcalis y los materiales cementantes. Hoy día nadie duda de que dicha hipótesis ha servido de base para el desarrollo de una nueva clase de materiales cementantes: “cementos alcalinos”. En el presente trabajo se hace una revisión sobre los aspectos teóricos más relevantes del papel de los álcalis en la formación de estos conglomerantes. También se da una visión genérica de su versatilidad, desarrollo industrial y estado de la normativa actual para regular en el futuro la fabricación de cementos y hormigones

  3. Calcium aluminate cement hydration in a high alkalinity environment

    Directory of Open Access Journals (Sweden)

    Palomo, Á.

    2009-03-01

    Full Text Available The present paper forms part of a broader research project that aims primarily to devise new cementitious products via the alkali activation of silico-aluminous materials. This work addresses the possibility of using small percentages of calcium aluminate cement (CAC as a source of reactive aluminium. For this reason, a preliminary review was needed of the behaviour of CACs in highly alkaline media (2, 8 and 12M NaOH solutions. Two, 28- and 180-day mechanical strength was determined and the reaction products were characterized with XRD and FTIR. The water-hydrated CAC was used as the control.The results obtained showed that CAC hardening took place much more slowly in highly alkaline media than in water. Nonetheless, the 28-day compressive strength obtained, ≥80MPa. As main reaction products, to ambient temperature and from the two days of cured, cubic aluminate C3AH6, and AH3 polymorphs are formed, instead of the usual hexagonal aluminatos (CAH10 and C2AH8 that are formed in the normal hydrate with water.El presente trabajo forma parte de una amplia investigación cuyo objetivo principal es el de elaborar nuevos materiales con propiedades cementantes mediante la activación alcalina de materiales de naturaleza silito-aluminosa. En estos estudios se contempla la posibilidad de utilizar pequeños porcentajes de cemento de aluminato de calcio (CAC como fuente de aluminio reactivo. Por ello inicialmente se ha estudiado el comportamiento de los CAC en medios fuertemente alcalinos (disoluciones de NaOH 2M, 8M y 12M. Se determinaron las resistencias mecánicas a 2, 28 y 180 días y se realizó una caracterización de los productos de reacción formados por DRX, FTIR. Como sistema de referencia se consideró la hidratación del CAC con agua.Los resultados obtenidos muestran que en medios fuertemente alcalinos se retrasan los procesos de rápido endurecimiento de CAC con agua. No obstante a 28 días se obtienen valores de resistencia a compresión

  4. Alkaline hydrothermal liquefaction of swine carcasses to bio-oil

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Ji-Lu, E-mail: triace@163.com; Zhu, Ming-Qiang; Wu, Hai-tang

    2015-09-15

    Highlights: • Swine carcasses can be converted to bio-oil by alkaline hydrothermal liquefaction. • It seems that the use of the bio-oil for heat or CHP is technically suitable. • Some valuable chemicals were found in the bio-oils. • The bio-oil and the solid residue constituted an energy efficiency of 93.63% for the feedstock. • The solid residue can be used as a soil amendment, to sequester C and for preparing activated carbon. - Abstract: It is imperative that swine carcasses are disposed of safely, practically and economically. Alkaline hydrothermal liquefaction of swine carcasses to bio-oil was performed. Firstly, the effects of temperature, reaction time and pH value on the yield of each liquefaction product were determined. Secondly, liquefaction products, including bio-oil and solid residue, were characterized. Finally, the energy recovery ratio (ERR), which was defined as the energy of the resultant products compared to the energy input of the material, was investigated. Our experiment shows that reaction time had certain influence on the yield of liquefaction products, but temperature and pH value had bigger influence on the yield of liquefaction products. Yields of 62.2 wt% bio-oil, having a high heating value of 32.35 MJ/kg and a viscosity of 305cp, and 22 wt% solid residue were realized at a liquefaction temperature of 250 °C, a reaction time of 60 min and a pH value of 9.0. The bio-oil contained up to hundreds of different chemical components that may be classified according to functional groups. Typical compound classes in the bio-oil were hydrocarbons, organic acids, esters, ketones and heterocyclics. The energy recovery ratio (ERR) reached 93.63%. The bio-oil is expected to contribute to fossil fuel replacement in stationary applications, including boilers and furnaces, and upgrading processes for the bio-oil may be used to obtain liquid transport fuels.

  5. Alkaline hydrothermal liquefaction of swine carcasses to bio-oil

    International Nuclear Information System (INIS)

    Zheng, Ji-Lu; Zhu, Ming-Qiang; Wu, Hai-tang

    2015-01-01

    Highlights: • Swine carcasses can be converted to bio-oil by alkaline hydrothermal liquefaction. • It seems that the use of the bio-oil for heat or CHP is technically suitable. • Some valuable chemicals were found in the bio-oils. • The bio-oil and the solid residue constituted an energy efficiency of 93.63% for the feedstock. • The solid residue can be used as a soil amendment, to sequester C and for preparing activated carbon. - Abstract: It is imperative that swine carcasses are disposed of safely, practically and economically. Alkaline hydrothermal liquefaction of swine carcasses to bio-oil was performed. Firstly, the effects of temperature, reaction time and pH value on the yield of each liquefaction product were determined. Secondly, liquefaction products, including bio-oil and solid residue, were characterized. Finally, the energy recovery ratio (ERR), which was defined as the energy of the resultant products compared to the energy input of the material, was investigated. Our experiment shows that reaction time had certain influence on the yield of liquefaction products, but temperature and pH value had bigger influence on the yield of liquefaction products. Yields of 62.2 wt% bio-oil, having a high heating value of 32.35 MJ/kg and a viscosity of 305cp, and 22 wt% solid residue were realized at a liquefaction temperature of 250 °C, a reaction time of 60 min and a pH value of 9.0. The bio-oil contained up to hundreds of different chemical components that may be classified according to functional groups. Typical compound classes in the bio-oil were hydrocarbons, organic acids, esters, ketones and heterocyclics. The energy recovery ratio (ERR) reached 93.63%. The bio-oil is expected to contribute to fossil fuel replacement in stationary applications, including boilers and furnaces, and upgrading processes for the bio-oil may be used to obtain liquid transport fuels

  6. Carbonation of alkaline paper mill waste to reduce CO{sub 2} greenhouse gas emissions into the atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Lopez, R. [Laboratoire de Geophysique Interne et Tectonophysique, CNRS-OSUG-UJF, Universite Joseph Fourier Grenoble I, Maison des Geosciences, BP 53, 38041 Grenoble Cedex (France); Department of Geology, University of Huelva, Campus ' El Carmen' , 21071 Huelva (Spain)], E-mail: rafael.perez@dgeo.uhu.es; Montes-Hernandez, G. [Laboratoire de Geophysique Interne et Tectonophysique, CNRS-OSUG-UJF, Universite Joseph Fourier Grenoble I, Maison des Geosciences, BP 53, 38041 Grenoble Cedex (France); Nieto, J.M. [Department of Geology, University of Huelva, Campus ' El Carmen' , 21071 Huelva (Spain); Renard, F. [Laboratoire de Geodynamique des Chaines Alpines, CNRS-OSUG-UJF, Universite Joseph Fourier Grenoble I, Maison des Geosciences, BP 53, 38041 Grenoble Cedex (France); Physics of Geological Processes, University of Oslo (Norway); Charlet, L. [Laboratoire de Geophysique Interne et Tectonophysique, CNRS-OSUG-UJF, Universite Joseph Fourier Grenoble I, Maison des Geosciences, BP 53, 38041 Grenoble Cedex (France)

    2008-08-15

    The global warming of Earth's near-surface, air and oceans in recent decades is a direct consequence of anthropogenic emission of greenhouse gases into the atmosphere such as CO{sub 2}, CH{sub 4}, N{sub 2}O and CFCs. The CO{sub 2} emissions contribute approximately 60% to this climate change. This study investigates experimentally the aqueous carbonation mechanisms of an alkaline paper mill waste containing about 55 wt% portlandite (Ca(OH){sub 2}) as a possible mineralogical CO{sub 2} sequestration process. The overall carbonation reaction includes the following steps: (1) Ca release from portlandite dissolution, (2) CO{sub 2} dissolution in water and (3) CaCO{sub 3} precipitation. This CO{sub 2} sequestration mechanism was supported by geochemical modelling of final solutions using PHREEQC software, and observations by scanning electron microscope and X-ray diffraction of final reaction products. According to the experimental protocol, the system proposed would favour the total capture of approx. 218 kg of CO{sub 2} into stable calcite/ton of paper waste, independently of initial CO{sub 2} pressure. The final product from the carbonation process is a calcite (ca. 100 wt%)-water dispersion. Indeed, the total captured CO{sub 2} mineralized as calcite could be stored in degraded soils or even used for diverse industrial applications. This result demonstrates the possibility of using the alkaline liquid-solid waste for CO{sub 2} mitigation and reduction of greenhouse effect gases into the atmosphere.

  7. Electrocatalytic Performance of Carbon Supported WO3-Containing Pd–W Nanoalloys for Oxygen Reduction Reaction in Alkaline Media

    Directory of Open Access Journals (Sweden)

    Nan Cui

    2018-05-01

    Full Text Available In this paper, we report that WOx containing nanoalloys exhibit stable electrocatalytic performance in alkaline media, though bulk WO3 is easy to dissolve in NaOH solution. Carbon supported oxide-rich Pd–W alloy nanoparticles (PdW/C with different Pd:W atom ratios were prepared by the reduction–oxidation method. Among the catalysts, the oxide-rich Pd0.8W0.2/C (Pd/W = 8:2, atom ratio exhibits the highest catalytic activity for the oxygen reduction reaction. The X-ray photoelectron spectroscopy data shows that ~40% of Pd atoms and ~60% of the W atoms are in their oxide form. The Pd 3d5/2 binding energy of the oxide-rich Pd–W nanoalloys is higher than that of Pd/C, indicating the electronic structure of Pd is affected by the strong interaction between Pd and W/WO3. Compare to Pd/C, the onset potential of the oxygen reduction reaction at the oxide-rich Pd0.8W0.2/C shifts to a higher potential. The current density (mA·mg Pd−1 at the oxide-rich Pd0.8W0.2/C is ~1.6 times of that at Pd/C. The oxide-rich Pd0.8W0.2/C also exhibits higher catalytic stability than Pd/C, which demonstrates that it is a prospective candidate for the cathode of fuel cells operating with alkaline electrolyte.

  8. 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...

  9. Stable Isotope Group 1982 progress report

    International Nuclear Information System (INIS)

    Stewart, M.K.

    1983-06-01

    The work of the Stable Isotope Group of the Institute of Nuclear Sciences during 1982, in the fields of isotope geology, isotope hydrology, geochronology, isotope biology and mass spectrometer instrumentation, is described

  10. Bartolome Island, Galapagos Stable Oxygen Calibration Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Galapagos Coral Stable Oxygen Calibration Data. Sites: Bartolome Island: 0 deg, 17'S, 90 deg 33' W. Champion Island: 1 deg, 15'S, 90 deg, 05' W. Urvina Bay (Isabela...

  11. Stable Isotope Group 1983 progress report

    International Nuclear Information System (INIS)

    Stewart, M.K.

    1984-06-01

    The work of the Stable Isotope Group of the Institute of Nuclear Sciences in the fields of isotope geology, isotope hydrology, geochronology, isotope biology and related fields, and mass spectrometer instrumentation, during 1983, is described

  12. Alkalinity to calcium flux ratios for corals and coral reef communities: variances between isolated and community conditions

    Directory of Open Access Journals (Sweden)

    Liana J.A. Murillo

    2014-02-01

    Full Text Available Calcification in reef corals and coral reefs is widely measured using the alkalinity depletion method which is based on the fact that two protons are produced for every mole of CaCO3 precipitated. This assumption was tested by measuring the total alkalinity (TA flux and Ca2+ flux of isolated components (corals, alga, sediment and plankton in reference to that of a mixed-community. Experiments were conducted in a flume under natural conditions of sunlight, nutrients, plankton and organic matter. A realistic hydrodynamic regime was provided. Groups of corals were run separately and in conjunction with the other reef components in a mixed-community. The TA flux to Ca2+ flux ratio (ΔTA: ΔCa2+ was consistently higher in the coral-only run (2.06 ± 0.19 than in the mixed-community run (1.60 ± 0.14, p-value = 0.011. The pH was higher and more stable in the mixed-community run (7.94 ± 0.03 vs. 7.52 ± 0.07, p-value = 3 × 10−5. Aragonite saturation state (Ωarag was also higher in the mixed-community run (2.51 ± 0.2 vs. 1.12 ± 0.14, p-value = 2 × 10−6. The sediment-only run revealed that sediment is the source of TA that can account for the lower ΔTA: ΔCa2+ ratio in the mixed-community run. The macroalgae-only run showed that algae were responsible for the increased pH in the mixed-community run. Corals growing in a mixed-community will experience an environment that is more favorable to calcification (higher daytime pH due to algae photosynthesis, additional TA and inorganic carbon from sediments, higher Ωarag. A paradox is that the alkalinity depletion method will yield a lower net calcification for a mixed-community versus a coral-only community due to TA recycling, even though the corals may be calcifying at a higher rate due to a more optimal environment.

  13. 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.

  14. Stable atomic hydrogen: Polarized atomic beam source

    International Nuclear Information System (INIS)

    Niinikoski, T.O.; Penttilae, S.; Rieubland, J.M.; Rijllart, A.

    1984-01-01

    We have carried out experiments with stable atomic hydrogen with a view to possible applications in polarized targets or polarized atomic beam sources. Recent results from the stabilization apparatus are described. The first stable atomic hydrogen beam source based on the microwave extraction method (which is being tested ) is presented. The effect of the stabilized hydrogen gas density on the properties of the source is discussed. (orig.)

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

    Directory of Open Access Journals (Sweden)

    J. Pätsch

    2018-06-01

    Full Text Available For the sediments of the central and southern North Sea different sources of alkalinity generation are quantified by a regional modelling system for the period 2000–2014. For this purpose a formerly global ocean sediment model coupled with a pelagic ecosystem model is adapted to shelf sea dynamics, where much larger turnover rates than in the open and deep ocean occur. To track alkalinity changes due to different nitrogen-related processes, the open ocean sediment model was extended by the state variables particulate organic nitrogen (PON and ammonium. Directly measured alkalinity fluxes and those derived from Ra isotope flux observation from the sediment into the pelagic are reproduced by the model system, but calcite building and calcite dissolution are underestimated. Both fluxes cancel out in terms of alkalinity generation and consumption. Other simulated processes altering alkalinity in the sediment, like net sulfate reduction, denitrification, nitrification, and aerobic degradation, are quantified and compare well with corresponding fluxes derived from observations. Most of these fluxes exhibit a strong positive gradient from the open North Sea to the coast, where large rivers drain nutrients and organic matter. Atmospheric nitrogen deposition also shows a positive gradient from the open sea towards land and supports alkalinity generation in the sediments. An additional source of spatial variability is introduced by the use of a 3-D heterogenous porosity field. Due to realistic porosity variations (0.3–0.5 the alkalinity fluxes vary by about 4 %. The strongest impact on interannual variations of alkalinity fluxes is exhibited by the temporal varying nitrogen inputs from large rivers directly governing the nitrate concentrations in the coastal bottom water, thus providing nitrate necessary for benthic denitrification. Over the time investigated the alkalinity effluxes decrease due to the decrease in the nitrogen supply by the rivers.

  16. 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.

  17. Metal mobilization under alkaline conditions in ash-covered tailings.

    Science.gov (United States)

    Lu, Jinmei; Alakangas, Lena; Wanhainen, Christina

    2014-06-15

    The aim of this study was to determine element mobilization and accumulation in mill tailings under alkaline conditions. The tailings were covered with 50 cm of fly ash, and above a sludge layer. The tailings were geochemically and mineralogically investigated. Sulfides, such as pyrrhotite, sphalerite and galena along with gangue minerals such as dolomite, calcite, micas, chlorite, epidote, Mn-pyroxene and rhodonite were identified in the unoxidized tailings. The dissolution of the fly ash layer resulted in a high pH (close to 12) in the underlying tailings. This, together with the presence of organic matter, increased the weathering of the tailings and mobilization of elements in the uppermost 47 cm of the tailings. All primary minerals were depleted, except quartz and feldspar which were covered by blurry secondary carbonates. Sulfide-associated elements such as Cd, Fe, Pb, S and Zn and silicate-associated elements such as Fe, Mg and Mn were released from the depletion zone and accumulated deeper down in the tailings where the pH decreased to circum-neutral. Sequential extraction suggests that Cd, Cu, Fe, Pb, S and Zn were retained deeper down in the tailings and were mainly associated with the sulfide phase. Calcium, Cr, K and Ni released from the ash layer were accumulated in the uppermost depletion zone of the tailings. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Synthesis and characterization of bismuth alkaline titanate powders

    Energy Technology Data Exchange (ETDEWEB)

    Torres-Huerta, A.M., E-mail: atorresh@ipn.mx [CICATA-Altamira, Instituto Politecnico Nacional, Km. 14.5 Carretera Tampico Puerto Industrial Altamira, Altamira, Tamps. 89600 (Mexico); Dominguez-Crespo, M.A. [CICATA-Altamira, Instituto Politecnico Nacional, Km. 14.5 Carretera Tampico Puerto Industrial Altamira, Altamira, Tamps. 89600 (Mexico); Hernandez-Perez, M.A. [ESIQIE, Metalurgia, Instituto Politecnico Nacional, Mexico, D. F (Mexico); Garcia-Zaleta, D.S. [CICATA-Altamira, Instituto Politecnico Nacional, Km. 14.5 Carretera Tampico Puerto Industrial Altamira, Altamira, Tamps. 89600 (Mexico); Brachetti-Sibaja, S.B. [CICATA-Altamira, Instituto Politecnico Nacional, Km. 14.5 Carretera Tampico Puerto Industrial Altamira, Altamira, Tamps. 89600 (Mexico); Instituto Tecnologico de Ciudad Madero, Av. 1o. de Mayo esq. Sor Juana Ines de la Cruz s/n Col. Los Mangos C.P.89440 Cd. Madero Tamaulipas (Mexico)

    2011-06-15

    In this work, samples of bismuth alkaline titanate, (K{sub 0.5}Na{sub 0.5}){sub (2-x/2)}Bi{sub (x/6)}TiO{sub 3}, (x = 0.05-0.75) have been prepared by conventional ceramic technique and molten salts. Metal oxides or carbonates powders were used as starting raw materials. The crystalline phase of the synthesized powders was identified by the X-ray diffraction (XRD) and particle morphology was characterized by scanning electron microscopy (SEM). Solid state reaction method was unsuccessful to obtain pellets. From XRD results, a rhombohedral structure was detected and the parameter lattice were estimated to be a = 5.5478 A and {alpha} = 59.48{sup o}. These parameters were used to refine the structure by Rietveld analysis. SEM results showed several morphologies. Apparently, bismuth is promoting the grain growth whose sizes vary from 30 nm to 180 nm It is expected that these materials can be utilized in practical applications as substitutes for lead zirconatetitanate (PZT)-based ceramics.

  19. ANTHRAQUINONE ADDITION IN THE ALKALINE PULPING OF Eucalyptus saligna

    Directory of Open Access Journals (Sweden)

    Lúcia Helena Jerônimo

    2009-10-01

    Full Text Available The present work evaluated different alkaline pulping conditions for Eucalyptus saligna wood. The objective was to evaluate the influence of the anthraquinone (AQ on the reduction of the total reduced sulfur (TRS in the aerial emissions, by reducing the sulfidity. The experiment consisted of 8 cooking with active alkali varying from  19 to 21%, sulfidity from  0 to 20% and anthraquinone from 0 to 0.1%, aiming to obtain  kappa numbers in the range 15.5±1.5. The H factor was used to control the relation time/temperature along cooking. The addition of anthraquinone increased the delignification rate allowing sulfidity reduction. The kraft/AQ pulping with sulfidities of 5 and 10% presented satisfactory results, making it possible the replacement of conventional kraft cooking, giving a reduction in process sulfidity without harms in pulping. In spite of a slightly lower performance, the soda/AQ cooking has potential to be used where the smell is a critical problem in the industrial operation.

  20. Arsenic removal from alkaline leaching solution using Fe (III) precipitation.

    Science.gov (United States)

    Wang, Yongliang; Lv, Cuicui; Xiao, Li; Fu, Guoyan; Liu, Ya; Ye, Shufeng; Chen, Yunfa

    2018-02-02

    The alkaline leaching solution from arsenic-containing gold concentrate contains a large amount of arsenate ions, which should be removed because it is harmful to the production process and to the environment. In this study, conventional Fe (III) precipitation was used to remove arsenic from the leaching solution. The precipitation reaction was carried out at the normal temperature, and the effects of pH value and Fe/As ratio on the arsenic removal were investigated. The results show that the removal rate of arsenic is distinctive at different pH values, and the effect is best within the pH range of 5.25-5.96. The removal rate can be further increased by increasing the ratio of Fe/As. When the pH = 5.25-5.96 and Fe/As > 1.8, the arsenic in the solution can be reduced to below 5 mg/L. However, the crystallinity of ferric arsenate is poor, and the particle size is small, most of which is about 1 μm. The leaching toxicity test shows the leaching toxicity of precipitates gradually decreased by the increase of Fe/As. The precipitates can be stored safely as the ratio of Fe/As exceeded 2.5.

  1. Archaeal Communities in a Heterogeneous Hypersaline-Alkaline Soil

    Directory of Open Access Journals (Sweden)

    Yendi E. Navarro-Noya

    2015-01-01

    Full Text Available In this study the archaeal communities in extreme saline-alkaline soils of the former lake Texcoco, Mexico, with electrolytic conductivities (EC ranging from 0.7 to 157.2 dS/m and pH from 8.5 to 10.5 were explored. Archaeal communities in the 0.7 dS/m pH 8.5 soil had the lowest alpha diversity values and were dominated by a limited number of phylotypes belonging to the mesophilic Candidatus Nitrososphaera. Diversity and species richness were higher in the soils with EC between 9.0 and 157.2 dS/m. The majority of OTUs detected in the hypersaline soil were members of the Halobacteriaceae family. Novel phylogenetic branches in the Halobacteriales class were detected in the soil, and more abundantly in soil with the higher pH (10.5, indicating that unknown and uncharacterized Archaea can be found in this soil. Thirteen different genera of the Halobacteriaceae family were identified and were distributed differently between the soils. Halobiforma, Halostagnicola, Haloterrigena, and Natronomonas were found in all soil samples. Methanogenic archaea were found only in soil with pH between 10.0 and 10.3. Retrieved methanogenic archaea belonged to the Methanosarcinales and Methanomicrobiales orders. The comparison of the archaeal community structures considering phylogenetic information (UniFrac distances clearly clustered the communities by pH.

  2. Reduction of Fumonisin Toxicity by Extrusion and Nixtamalization (Alkaline Cooking).

    Science.gov (United States)

    Voss, Kenneth; Ryu, Dojin; Jackson, Lauren; Riley, Ronald; Gelineau-van Waes, Janee

    2017-08-23

    Fumonisins are mycotoxins found in corn. They are toxic to animals and cause cancer in rodents and neural tube defects in LM/Bc mice. Reducing their concentrations in corn-based foods is therefore desirable. Chemical analysis or in vitro bioassays of food extracts might not detect toxic fumonisin reaction products that are unknown or unextractable from food matrices, thus potentially underestimating in vivo toxicity. The effectiveness of two common cooking methods, extrusion and nixtamalization (alkaline cooking), to reduce the toxicity of fumonisin-contaminated corn grits (extrusion) and whole kernel corn (nixtamalization) was shown by means of rat feeding bioassays using fumonisin-specific kidney effects as indicators of potential toxicity. A third bioassay showed that in contrast to fumonisin B 1 (FB 1 ), hydrolyzed fumonisin B 1 (HFB 1 ; formed from FB 1 during nixtamalization) did not cause neural tube defects in LM/Bc mice. The findings indicate that extrusion and nixtamalization reduce the potential toxicity of FB 1 -contaminated corn.

  3. Daily intakes of alkaline earth metals in Japanese males

    International Nuclear Information System (INIS)

    Shiraishi, Kunio; Yamamoto, Masayoshi; Ueno, Kaoru

    1994-01-01

    Diet samples were collected for two duplicate portion studies and one market basket study. 226 Ra in the diet samples was determined by alpha spectrometry and daily intake was estimated as 23 mBq (0.62 pCi) per person. Other alkaline earth metals were determined by inductively coupled plasma atomic-emission spectrometry. Average mineral intakes of calcium, magnesium, strontium, and barium were 0.55 g, 0.21 g, 2.3 mg, and 0.39 mg, respectively. Element ratios magnesium:calcium 0.38, strontium:calcium 4.2 x 10 -3 barium:calcium 7.1 X 10 -4 , and Ra:calcium 1.1 x 10 -12 were found in the diet; these compared with element ratios in Japanese vertebrae of magnesium:calcium 0.011, strontium:calcium 3.1 x 10 -4 , barium:calcium 2.7 x 10 -5 , and radium:calcium 2.6 x 10 -14 . Observed ratios, defined as the element ratio in bone divided by the respective element intake ratio in Japanese males, were as follows: 226 Ra 0.02, magnesium 0.03, strontium 0.07, and barium 0.04

  4. Optimization and evaluation of alkaline potassium permanganate pretreatment of corncob.

    Science.gov (United States)

    Ma, Lijuan; Cui, Youzhi; Cai, Rui; Liu, Xueqiang; Zhang, Cuiying; Xiao, Dongguang

    2015-03-01

    Alkaline potassium permanganate solution (APP) was applied to the pretreatment of corncob with a simple and effective optimization of APP concentration, reaction time, temperature and solid to liquid ratio (SLR). The optimized pretreatment conditions were at 2% (w/v) potassium permanganate with SLR of 1:10 treating for 6h at 50°C. This simple one-step treatment resulted in significant 94.56% of the cellulose and 81.47% of the hemicellulose recoveries and 46.79% of the lignin removal of corncob. The reducing sugar in the hydrolysate from APP-pretreated corncob was 8.39g/L after 12h enzymatic hydrolysis, which was 1.44 and 1.29 folds higher than those from raw and acid pretreated corncobs. Physical characteristics, crystallinity and structure of the pretreated corncob were analyzed and assessed by SEM, XRD and FTIR. The APP pretreatment process was novel and enhanced enzymatic hydrolysis of lignocellulose by affecting composition and structural features. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Electrochemistry of Pt (100) in alkaline media: A voltammetric study

    Science.gov (United States)

    van der Vliet, Dennis F.; Koper, Marc T. M.

    2010-10-01

    Pt (100) is one of the fcc metal surface planes that reconstruct upon annealing at high temperatures. The state of the surface is important in electrochemistry, in order to correlate catalytic behavior with surface structure. Therefore, the behavior of single crystalline Pt (100) in alkaline media was investigated, with particular attention paid to surface long-range order. It was found that, in line with previous results, the manner of cooling the crystal after annealing influenced the state of surface significantly, with a profound effect on blank cyclic voltammetry as well as on carbon monoxide oxidation. Different ratios of inert and reductive gases were used to see if an optimal mixture could be obtained. Using air, argon, hydrogen, CO, and combinations of these gases gave rise to different states of the surface, with clear observable differences in blank voltammetric behavior and CO stripping. Also, the effect of alkali-metal cations and bromide on the blank and CO stripping voltammetry was investigated. Our main conclusion is that cooling in a carbon monoxide containing gas gives a clean, almost defect-free surface with long-range 1 × 1 symmetry. A similar surface can also be prepared with a hydrogen-containing cooling gas, but the content of hydrogen in that stream is critical.

  6. Changes of serum alkaline phosphatase isoenzymes in fasted rats.

    Science.gov (United States)

    Wada, H; Niwa, N; Hayakawa, T; Tsuge, H

    1996-10-01

    Changes of serum alkaline phosphatase (sALP) isoenzymes under fasting conditions were examined using polyacrylamide gel electrophoresis (PAGE), amino-acids (L-phenylalanine (L-Phe), L-homoarginine (L-HArg)) inhibition and wheat germ agglutinin (WGA) treatment. The sALP of non-fasted rats was separated into three bands (S1, S2, S3) by PAGE. The molecular weight (M.W.) of S1 corresponded to that of an isoenzyme found in the ileum. By the addition of L-Phe, the staining intensity of S1 was weakened, S2 and S3 remained unchanged and the total activity of the isoenzymes extracted from intestine decreased. On the other hand, the activity of isoenzymes extracted from kidney and bone decreased by the addition of L-HArg. Therefore, S1 was judged to be derived from intestine. The activities of total sALP and S1 decreased from 16 h of fasting. Total sALP activity and sALP activity of the supernatant prepared by WGA treatment decreased, whereas the ALP activity of the precipitate (difference between total sALP activity and supernatant sALP activity) did not change. The activity band of the precipitate corresponded to that of S3 by PAGE. Therefore, S3 was judged to be derived from bone. In conclusion, under fasting conditions, the activity of S1 decreased while the activities of S2 and S3 remained unchanged.

  7. Alkaline Leaching of Low Zinc Content Iron-Bearing Sludges

    Directory of Open Access Journals (Sweden)

    Gargul K.

    2016-03-01

    Full Text Available Various types of waste materials containing zinc (e.g. dusts and sludges from gas dedusting process are obtained in steel industry. The contents of Zn in these materials may vary considerably. Even a low concentration of zinc in recirculated products precludes their recycling in ferrous metallurgy aggregates. Long storage of this type of material can lead to contamination of soil and water by zinc compounds which can be leached out by acid rain, for example. This paper focuses on research involving alkaline leaching tests of low zinc content iron-bearing materials. These tests were preceded by the analysis of the elemental, phase and grain size composition, and analysis of the thermodynamic conditions of the leaching process. The main aim of research was to decrease the content of the zinc in the sludge to the level where it is suitable as an iron-bearing material for iron production (~1% Zn. Leaching at elevated temperatures (368 K, 60 min has led to a decrease in the zinc content in the sludge of about 66%. The research revealed that long hour leaching (298 K, 100 hours carried out at ambient temperatures caused a reduction in zinc content by 60% to the value of 1.15-1.2% Zn.

  8. 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)

  9. Naphthenic acid removal from HVGO by alkaline earth metal catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Ding, L.; Rahimi, P.; Hawkins, R.; Bhatt, S.; Shi, Y. [National Centre for Upgrading Technology, Devon, AB (Canada); Natural Resources Canada, Devon, AB (Canada). CanmetENERGY

    2009-07-01

    This poster highlighted a study that investigated naphthenic acid removal from bitumen-derived heavy vacuum gas oil (HVGO) by thermal cracking and catalytic decarboxylation over alkaline earth-metal oxides and ZnO catalysts in a batch reactor and a continuous fixed-bed reactor. X-ray diffraction (XRD), thermogravimetric-differential thermal analysis (TG-DTA) temperature-programmed desorption (TPD) of carbon dioxide (CO{sub 2}-TPD), and scanning electron microscopy were used to characterize the fresh and spent catalysts. With MgO and ZnO, naphthenic acid removal proceeded via catalytic decarboxylation. No crystalline phase changes were observed after reaction. With CaO, multiple pathways such as catalytic decarboxylation, neutralization, and thermal cracking were responsible for naphthenic acid conversion. The spent catalysts contained Ca(OH){sub 2} and CaCO{sub 3}. With BaO, naphthenic acid conversion occurred through neutralization. All BaO was converted to Ba(OH){sub 2} during the reaction. tabs., figs.

  10. Process for recovering tungsten from alkaline leaching solution of tungsten ores

    International Nuclear Information System (INIS)

    Onozaki, S.; Nemoto, S.; Hazeyama, T.

    1976-01-01

    This invention relates to a process for recovering tungsten from an alkaline leaching solution of tungsten ores. This invention comprises adjusting the pH of an alkaline leaching solution which is obtained by lixiviating ore containing tungsten with an alkaline solution to 7--8 with acid to oxidize molybdic acid ions in the solution, adding a sulfide donor, then precipitating molybdenum sulfide compounds by adjusting the pH value of the solution to 2--3. Tungstic acid ions are recovered as calcium tungstate by the addition of a calcium ion donor after the molybdenum sulfide compounds are separated

  11. A radiochemical study of gold electrodeposition kinetics in alkaline cyanide solutions

    International Nuclear Information System (INIS)

    Poshkus, D.; Agafonovas, G.; Zhebrauskas, A.

    1995-01-01

    Kinetics of gold electrodeposition from alkaline cyanide solutions was investigated by the use of labelled gold 195 atoms. The absorption of cyanide containing species from alkaline cyanide and dicyanoaurate solutions on a gold electrode by the use of labelled carbon atoms was investigated. Polarization curves of anodic dissolution and cathodic deposition of gold in alkaline cyanide solutions were obtained. The values of standard potential, exchange current density, transfer coefficient and standard polarization rate were determined from polarization curves. The errors in current density caused by the nuclear disintegration statistics were evaluated. 28 refs., 1 tab., 4 figs

  12. On the capacity to the complexing of alkaline earth metal and magnesium chromates

    International Nuclear Information System (INIS)

    Orekhov, O.L.

    1978-01-01

    Considered is the capacity to the complexing of magnesium chromates and alkaline earth metal chromates with ammonium chromates in aqueous solutions. It has been established that the complexing of alkaline earth metal and magnesium chromates is effected by a nature of initial salts as well as their solubilities and the presence of crystallization water. Capacity of magnesium ions and alkaline rare earth metals to the complexing decreases in a series of Mg-Ca-Sr-Ba. Ca complexes exceed magnesium derivatives in respect of stability

  13. When VSEPR fails: experimental and theoretical investigations of the behavior of alkaline-earth-metal acetylides.

    Science.gov (United States)

    Guino-o, Marites A; Alexander, Jacob S; McKee, Michael L; Hope, Håkon; Englich, Ulrich B; Ruhlandt-Senge, Karin

    2009-11-09

    The synthesis, structural, and spectral characterization as well as a theoretical study of a family of alkaline-earth-metal acetylides provides insights into synthetic access and the structural and bonding characteristics of this group of highly reactive compounds. Based on our earlier communication that reported unusual geometry for a family of triphenylsilyl-substituted alkaline-earth-metal acetylides, we herein present our studies on an expanded family of target derivatives, providing experimental and theoretical data to offer new insights into the intensively debated theme of structural chemistry in heavy alkaline-earth-metal chemistry.

  14. Local Search Approaches in Stable Matching Problems

    Directory of Open Access Journals (Sweden)

    Toby Walsh

    2013-10-01

    Full Text Available The stable marriage (SM problem has a wide variety of practical applications, ranging from matching resident doctors to hospitals, to matching students to schools or, more generally, to any two-sided market. In the classical formulation, n men and n women express their preferences (via a strict total order over the members of the other sex. Solving an SM problem means finding a stable marriage where stability is an envy-free notion: no man and woman who are not married to each other would both prefer each other to their partners or to being single. We consider both the classical stable marriage problem and one of its useful variations (denoted SMTI (Stable Marriage with Ties and Incomplete lists where the men and women express their preferences in the form of an incomplete preference list with ties over a subset of the members of the other sex. Matchings are permitted only with people who appear in these preference lists, and we try to find a stable matching that marries as many people as possible. Whilst the SM problem is polynomial to solve, the SMTI problem is NP-hard. We propose to tackle both problems via a local search approach, which exploits properties of the problems to reduce the size of the neighborhood and to make local moves efficiently. We empirically evaluate our algorithm for SM problems by measuring its runtime behavior and its ability to sample the lattice of all possible stable marriages. We evaluate our algorithm for SMTI problems in terms of both its runtime behavior and its ability to find a maximum cardinality stable marriage. Experimental results suggest that for SM problems, the number of steps of our algorithm grows only as O(n log(n, and that it samples very well the set of all stable marriages. It is thus a fair and efficient approach to generate stable marriages. Furthermore, our approach for SMTI problems is able to solve large problems, quickly returning stable matchings of large and often optimal size, despite the

  15. Rb-Sr age of the Sivamalai alkaline complex, Tamil Nadu

    International Nuclear Information System (INIS)

    Subba Rao, T.V.; Narayana, B.L.; Gopalan, K.

    1994-01-01

    The Sivamalai alkaline complex comprises ferro-, pyroxene- hornblende-and nepheline-syenites. Field relations show that the nepheline syenites followed the emplacement of non-feldspathoidal syenites. Mineralogical data on the syenite suite have been reviewed. The Sivamalai alkaline rocks are not strongly enriched in rare-earth elements like most miaskites. Rb-Sr isotopic analyses of a suite of six samples from the various members of the complex define an isochron corresponding to an age of 623 ± 21 Ma (2σ) and initial Sr ratio of 0.70376 ± 14 (2σ). This is consistent with a model of fractional crystallization of a parent magma derived from an upper mantle source with apparently no isotopic evidence for more than one magma source for the complex. The Sivamalai alkaline complex represents a Pan-African alkaline magmatic event in the southern granulite terrane of peninsular India. (author). 26 refs., 4 figs., 4 tabs

  16. Enhanced biogas production from penicillin bacterial residue by thermal-alkaline pretreatment

    International Nuclear Information System (INIS)

    Zhong, Weizhang; Li, Guixia; Gao, Yan; Li, Zaixing; Geng, Xiaoling; Li, Yubing; Yang, Jingliang; Zhou, Chonghui

    2015-01-01

    In this study, the orthogonal experimental design was used to determine the optimum conditions for the effect of thermal alkaline; pretreatment on the anaerobic digestion of penicillin bacterial residue. The biodegradability of the penicillin; bacterial residue was evaluated by biochemical methane potential tests in laboratory. The optimum values of temperature,; alkali concentration, pretreatment time and moisture content for the thermal-alkaline pretreatment were determined as; 70 °C, 6% (w/v), 30 min, and 85%, respectively. Thermal-alkaline pretreatment could significantly enhance the soluble; chemical oxygen demand solubilization, the suspended solid solubilization and the biodegradability. Biogas production; was enhanced by the thermal-alkaline pretreatment, probably as a result of the breakdown of cell walls and membranes of; micro-organisms, which may facilitate the contact between organic molecules and anaerobic microorganisms.; Keywords: penicillin bacterial residue; anaerobic digestion; biochemical methane potential tests; pretreatment

  17. FULL ALKALINE HYDROLYSIS OF PESTICIDE DYMETOAT WITH OBTAINING ECO-SAFE PRODUCTS

    Directory of Open Access Journals (Sweden)

    А. Ранський

    2012-04-01

    Full Text Available In this work alkaline hydrolysis of the dimetoat pesticide and ways of determination of final substanceswere presented. Dependence passing of the reaction and time of the reaction was simulated

  18. Conformational changes in the bilirubin-human serum albumin complex at extreme alkaline pH

    DEFF Research Database (Denmark)

    Honoré, B; Frandsen, P C

    1986-01-01

    Light-absorption, c.d. and fluorescence of the bilirubin-albumin complex were investigated at extreme alkaline pH. Above pH 11.1 albumin binds the bilirubin molecule, twisted oppositely to the configuration at more neutral pH. On the basis of light-absorption it is shown that two alkaline...... transitions occur. The first alkaline transition takes place at pH between 11.3 and 11.8, co-operatively dissociating at least six protons. The second alkaline transition takes place at pH between 11.8 and 12.0. It probably implies a reversible unfolding of the albumin molecule, increasing the distance...

  19. 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.

  20. Molecular dynamics of liquid alkaline-earth metals near the melting ...

    Indian Academy of Sciences (India)

    computed the velocity autocorrelation function (VACF), its memory function and ... Since alkaline-earth metals are simple like metals, the main difficulty in the calcu- lation of ..... recall that the conventional binding energy can be written [23] as.

  1. Acceleration of gelation and promotion of mineralization of chitosan hydrogels by alkaline phosphatase

    NARCIS (Netherlands)

    Douglas, T.E.L.; Skwarczynska, A.; Modrzejewska, Z.; Balcaen, L.; Schaubroeck, D.; Lycke, S.; Vanhaecke, F.; Vandenabeele, P.; Dubruel, P.; Jansen, J.A.; Leeuwenburgh, S.C.G.

    2013-01-01

    Thermosensitive chitosan hydrogels containing sodium beta-glycerophosphate (beta-GP), whose gelation is induced by increasing temperature to body temperature, were functionalized by incorporation of alkaline phosphatase (ALP), an enzyme involved in mineralization of bone. ALP incorporation led to

  2. Near relativistic study of binded levels in atoms. Application to alkaline atoms

    International Nuclear Information System (INIS)

    Varade, A.; Delgado-Barrio, G.; Villarreal, P.

    1985-01-01

    A model is described for the calculation of the atomic binding energies. The Pauli equation has been solved with a local potential. The results for alkaline atoms are reported here and compared with the perturbative calculation and experimental data. (author)

  3. Application of alkaline leaching to the extraction of uranium from shale of the Vosges

    International Nuclear Information System (INIS)

    Mouret, P.; Pottier, P.; Le Bris, J.

    1958-01-01

    Description of chemical treatment of Vosges shales to obtain uranium by alkaline leaching. Mineralogy aspects of ore, physical and chemical conditions of leaching, solid/liquid separation, uranium recovery by either ion exchange process or electrolytic precipitation. (author) [fr

  4. A high selectivity quaternized polysulfone membrane for alkaline direct methanol fuel cells

    CSIR Research Space (South Africa)

    Abuin, GC

    2015-04-01

    Full Text Available polysulfone membrane for alkaline direct methanol fuel cells Graciela C. Abuina, Esteban A. Franceschinib, Patrick Nonjolac, Mkhulu K. Mathec, Mmalewane Modibedic, Horacio R. Cortib,* aCentro de Procesos Superficiales, Instituto Nacional de Tecnología...

  5. Effect of alkaline treatment on the sulfate content and quality of semi ...

    African Journals Online (AJOL)

    Administrator

    2015-05-06

    May 6, 2015 ... quality of semi-refined carrageenan prepared from seaweed Kappaphycus ... importance for industry to deliver a standard product and to develop new ..... alkaline extraction media (compared to pure water) have also been ...

  6. Pollution control and resource reuse for alkaline hydrometallurgy of amphoteric metal hazardous wastes

    CERN Document Server

    Youcai, Zhao

    2017-01-01

    This book provides a comprehensive description of alkaline hydrometallurgy of amphoteric metal hazardous wastes. Topics focus on leaching of zinc and lead hazardous wastes, purification of leach solution of zinc and lead, electrowinning of zinc and lead from purified alkaline solutions, chemical reactions taking place in the production flowsheets, thermodynamic and spent electrolyte regeneration, alkaline hydrometallurgy of low-grade smithsonite ores, recovery of molybdenum and tungsten using ion flotation and solvent extraction processes and their application in chemical synthesis of Nb and Ta inorganic compounds, and industrial scale production of 1500-2000 t/a zinc powder using alkaline leaching–electrowinning processes. Processes described are cost-effective, generate lesser secondary pollutants, and have been applied widely in China. Readers that will find the book appealing include solid waste engineers, environmental managers, technicians, recycling coordinators, government officials, undergraduates ...

  7. Genotoxicity of cadmium in marine diatom Chaetoceros tenuissimus using the alkaline Comet assay

    Digital Repository Service at National Institute of Oceanography (India)

    Desai, S.R.; Verlecar, X.N.; Nagarajappa; Goswami, U.

    of Cd increased growth of the diatom decreased. Alkaline single-cell gel electrophoresis (Comet assay) method, which is highly sensitive in detection of DNA damage in eukaryotic cells, was used to observe genomic changes in marine diatom cells. DNA...

  8. Subcellular localization of alkaline phosphatase in Bacillus licheniformis 749/C by immunoelectron microscopy with colloidal gold

    International Nuclear Information System (INIS)

    Tinglu, G.; Ghosh, A.; Ghosh, B.K.

    1984-01-01

    Subcellular distribution of the alkaline phosphatase of Bacillus licheniformis 749/C was determined by an immunoelectron microscopy method. Anti-alkaline phosphatase antibody labeled with 15- to 18-nm colloidal gold particles (gold-immunoglobulin G [IgG] complex) were used for the study. Both the plasma membrane and cytoplasmic material were labeled with the gold-IgG particles. These particles formed clusters in association with the plasma membrane; in contrast, in the cytoplasm the particles were largely dispersed, and only a few clusters were found. The gold-IgG binding was quantitatively estimated by stereological analysis of labeled, frozen thin sections. This estimation of a variety of control samples showed that the labeling was specific for the alkaline phosphatase. Cluster formation of the gold -IgG particles in association with the plasma membrane suggests that existence of specific alkaline phosphatase binding sites (receptors) in the plasma membrane of B. licheniformis 749/C. 27 references, 6 figures, 1 table

  9. Comparison of mine water neutralisation efficiencies of different alkaline generating agents

    CSIR Research Space (South Africa)

    Masindi, Vhahangwele

    2017-08-01

    Full Text Available effluent requires a prudent management and an effective treatment option prior release to different receiving compartments of the environment. The present study was therefore designed with the aim of evaluating the efficiencies of different alkaline...

  10. Alkaline and non-aqueous proton-conducting pouch-cell batteries

    Science.gov (United States)

    Young, Kwo-hsiung; Nei, Jean; Meng, Tiejun

    2018-01-02

    Provided are sealed pouch-cell batteries that are alkaline batteries or non-aqueous proton-conducing batteries. A pouch cell includes a flexible housing such as is used for pouch cell construction where the housing is in the form of a pouch, a cathode comprising a cathode active material suitable for use in an alkaline battery, an anode comprising an anode active material suitable for use in an alkaline battery, an electrolyte that is optionally an alkaline or proton-conducting electrolyte, and wherein the pouch does not include or require a safety vent or other gas absorbing or releasing system as the anode active material and the cathode active material do not increase the internal atmospheric pressure any more than 2 psig during cycling. The batteries provided function contrary to the art recognized belief that such battery systems were impossible due to unacceptable gas production during cycling.

  11. Effect of thiol group on the curing process of alkaline developable photo-resists

    International Nuclear Information System (INIS)

    Hidetaka Oka; Masaki Ohwa; Hisatoshi Kura

    1999-01-01

    Photosensitivity of a conventional radical photo-initiator in an alkaline developable photoresist is boosted by substitution with a thiol group. Evidence is presented that the thiol group acts via chain transfer mechanism

  12. Desorption of acetone from alkaline-earth exchanged Y zeolite after propane selective oxidation

    NARCIS (Netherlands)

    Xu, J.; Mojet, Barbara; van Ommen, J.G.; Lefferts, Leonardus

    2004-01-01

    The desorption of products from a series of alkaline-earth exchanged Y zeolites after room-temperature propane selective oxidation was investigated by in situ infrared and mass spectroscopy. The intermediate product, isopropylhydroperoxide (IHP), did not desorb during

  13. The alkali and alkaline earth metal doped ZnO nanotubes: DFT studies

    International Nuclear Information System (INIS)

    Peyghan, Ali Ahmadi; Noei, Maziar

    2014-01-01

    Doping of several alkali and alkaline earth metals into sidewall of an armchair ZnO nanotube has been investigated by employing the density functional theory in terms of energetic, geometric, and electronic properties. It has been found that doping processes of the alkali and alkaline metals are endothermic and exothermic, respectively. Based on the results, contrary to the alkaline metal doping, the electronic properties of the tube are much more sensitive to alkali metal doping so that it is transformed from intrinsic semiconductor with HOMO–LUMO energy gap of 3.77 eV to an extrinsic semiconductor with the energy gap of ∼1.11–1.95 eV. The doping of alkali and alkaline metals increases and decreases the work function of the tube, respectively, which may influence the electron emission from the tube surface

  14. The application of extraction chromatography for analysis of alkali and alkaline earth uranates

    International Nuclear Information System (INIS)

    Tomazic, B.; Cukovic, M.

    1978-01-01

    A method for rapid analysis of alkali and alkaline earth uranates is proposed. The method is based on the use of an HDEHP extraction chromatographic column, which makes possible quantitative separations of alkaline earth ions from macroamounts of uranium(VI). Composition of alkaline earth uranates, based on regression analysis, are presented. The results, which show that under the given experimental conditions alkaline earth triuranates precipitate, are in good agreement with previous data from same laboratory. In addition the HDEHP extraction chromatographic column can be suggested as a tool for separation of representative fission products from irradiated uranium for the purpose of determination of the burn-up factor of nuclear reactor materials. (T.G.)

  15. FURNACE INJECTION OF ALKALINE SORBENTS FOR SULFURIC ACID REMOVAL

    Energy Technology Data Exchange (ETDEWEB)

    Gary M. Blythe

    2004-01-01

    The objective of this project has been to demonstrate the use of alkaline reagents injected into the furnace of coal-fired boilers as a means of controlling sulfuric acid emissions. The project was co-funded by the U.S. DOE National Energy Technology Laboratory under Cooperative Agreement DE-FC26-99FT40718, along with EPRI, the American Electric Power Company (AEP), FirstEnergy Corporation, the Tennessee Valley Authority, and Carmeuse North America. Sulfuric acid controls are becoming of increased interest for coal-fired power generating units for a number of reasons. In particular, sulfuric acid can cause plant operation problems such as air heater plugging and fouling, back-end corrosion, and plume opacity. These issues will likely be exacerbated with the retrofit of selective catalytic reduction (SCR) for NOX control, as SCR catalysts are known to further oxidize a portion of the flue gas SO{sub 2} to SO{sub 3}. The project tested the effectiveness of furnace injection of four different magnesium-based or dolomitic alkaline sorbents on full-scale utility boilers. These reagents were tested during one- to two-week tests conducted on two FirstEnergy Bruce Mansfield Plant (BMP) units. One of the sorbents tested was a magnesium hydroxide slurry byproduct from a modified Thiosorbic{reg_sign} Lime wet flue gas desulfurization process. The other three sorbents are available commercially and include dolomite, pressure-hydrated dolomitic lime, and commercially available magnesium hydroxide. The dolomite reagent was injected as a dry powder through out-of-service burners. The other three reagents were injected as slurries through air-atomizing nozzles inserted through the front wall of the upper furnace. After completing the four one- to two-week tests, the most promising sorbents were selected for longer-term (approximately 25-day) full-scale tests on two different units. The longer-term tests were conducted to confirm sorbent effectiveness over extended operation on two

  16. Metabolic studies in man using stable isotopes

    International Nuclear Information System (INIS)

    Faust, H.; Jung, K.; Krumbiegel, P.

    1993-01-01

    In this project, stable isotope compounds and stable isotope pharmaceuticals were used (with emphasis on the application of 15 N) to study several aspects of nitrogen metabolism in man. Of the many methods available, the 15 N stable isotope tracer technique holds a special position because the methodology for application and nitrogen isotope analysis is proven and reliable. Valid routine methods using 15 N analysis by emission spectrometry have been demonstrated. Several methods for the preparation of biological material were developed during our participation in the Coordinated Research Programme. In these studies, direct procedures (i.e. use of diluted urine as a samples without chemical preparation) or rapid isolation methods were favoured. Within the scope of the Analytical Quality Control Service (AQCS) enriched stable isotope reference materials for medical and biological studies were prepared and are now available through the International Atomic Energy Agency. The materials are of special importance as the increasing application of stable isotopes as tracers in medical, biological and agricultural studies has focused interest on reliable measurements of biological material of different origin. 24 refs

  17. 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

  18. Imaging of alkaline phosphatase activity in bone tissue.

    Directory of Open Access Journals (Sweden)

    Terence P Gade

    Full Text Available The purpose of this study was to develop a paradigm for quantitative molecular imaging of bone cell activity. We hypothesized the feasibility of non-invasive imaging of the osteoblast enzyme alkaline phosphatase (ALP using a small imaging molecule in combination with (19Flourine magnetic resonance spectroscopic imaging ((19FMRSI. 6, 8-difluoro-4-methylumbelliferyl phosphate (DiFMUP, a fluorinated ALP substrate that is activatable to a fluorescent hydrolysis product was utilized as a prototype small imaging molecule. The molecular structure of DiFMUP includes two Fluorine atoms adjacent to a phosphate group allowing it and its hydrolysis product to be distinguished using (19Fluorine magnetic resonance spectroscopy ((19FMRS and (19FMRSI. ALP-mediated hydrolysis of DiFMUP was tested on osteoblastic cells and bone tissue, using serial measurements of fluorescence activity. Extracellular activation of DiFMUP on ALP-positive mouse bone precursor cells was observed. Concurringly, DiFMUP was also activated on bone derived from rat tibia. Marked inhibition of the cell and tissue activation of DiFMUP was detected after the addition of the ALP inhibitor levamisole. (19FMRS and (19FMRSI were applied for the non-invasive measurement of DiFMUP hydrolysis. (19FMRS revealed a two-peak spectrum representing DiFMUP with an associated chemical shift for the hydrolysis product. Activation of DiFMUP by ALP yielded a characteristic pharmacokinetic profile, which was quantifiable using non-localized (19FMRS and enabled the development of a pharmacokinetic model of ALP activity. Application of (19FMRSI facilitated anatomically accurate, non-invasive imaging of ALP concentration and activity in rat bone. Thus, (19FMRSI represents a promising approach for the quantitative imaging of bone cell activity during bone formation with potential for both preclinical and clinical applications.

  19. Rare Mineralogy in Alkaline Ultramafic Rocks, Western Kentucky Fluorspar District

    Science.gov (United States)

    Anderson, W.

    2017-12-01

    The alkaline ultramafic intrusive dike complex in the Western Kentucky Fluorspar District contains unusual mineralogy that was derived from mantle magma sources. Lamprophyre and peridotite petrologic types occur in the district where altered fractionated peridotites are enriched in Rare Earth Elements (REE) and some lamprophyre facies are depleted in incompatible elements. Unusual minerals in dikes, determined by petrography and X-ray diffraction, include schorlomite and andradite titanium garnets, astrophyllite, spodumene, niobium rutile, wüstite, fluoro-tetraferriphlogopite, villiaumite, molybdenite, and fluocerite, a REE-bearing fluoride fluorescent mineral. Mixing of MVT sphalerite ore fluids accompanies a mid-stage igneous alteration and intrusion event consistent with paragenetic studies. The presence of lithium in the spodumene and fluoro-tetraferriphlogopite suggests a lithium phase in the mineral fluids, and the presence of enriched REE in dikes and fluorite mineralization suggest a metasomatic event. Several of these rare minerals have never been described in the fluorspar district, and their occurrence suggests deep mantle metasomatism. Several REE-bearing fluoride minerals occur in the dikes and in other worldwide occurrences, they are usually associated with nepheline syenite and carbonatite differentiates. There is an early and late stage fluoride mineralization, which accompanied dike intrusion and was also analyzed for REE content. One fluorite group is enriched in LREE and another in MREE, which suggests a bimodal or periodic fluorite emplacement. Whole-rock elemental analysis was chondrite normalized and indicates that some of the dikes are slightly enriched in light REE and show a classic fractionation enrichment. Variations in major-element content; high titanium, niobium, and zirconium values; and high La/Yb, Zr/Y, Zr/Hf, and Nb/Ta ratios suggest metasomatized lithospheric-asthenospheric mantle-sourced intrusions. The high La/Yb ratios in some

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

    Science.gov (United States)

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

    2001-08-01

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