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Sample records for di-sodium hydrogen phosphate

  1. (Liquid + liquid) and (liquid + solid) equilibrium of aqueous two-phase systems containing poly ethylene glycol di-methyl ether 2000 and di-sodium hydrogen phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Zafarani-Moattar, Mohammed Taghi, E-mail: zafarani47@yahoo.co [Physical Chemistry Department, University of Tabriz, Tabriz 51664 (Iran, Islamic Republic of); Nasiri, Saeed [Physical Chemistry Department, University of Tabriz, Tabriz 51664 (Iran, Islamic Republic of)

    2010-09-15

    (Liquid + liquid) equilibrium (LLE) for the {l_brace}poly ethylene glycol di-methyl ether 2000 (PEGDME{sub 2000}) + Na{sub 2}HPO{sub 4} + H{sub 2}O{r_brace} system have been determined experimentally at T = (298.15, 308.15, 313.15, and 318.15) K. The effects of temperature on the binodals and tie-lines for the investigated aqueous two-phase system (ATPS) have been studied. An empirical non-linear expression developed by Merchuk was used for reproducing the experimental binodal data. In this work, the three fitting parameters of the Merchuk equation were obtained with the temperature dependence expressed in the linear form with (T - T{sub 0}) K as a variable. Furthermore, the modified local composition segment-based NRTL and Wilson models and also osmotic virial equation were used to describe the LLE data of the studied system. Also, the effects of the type of salt on LLE are discussed. In addition, the effects of end groups of the polymers PEGDME{sub 2000} and poly ethylene glycol 2000 on phase forming ability were studied. The complete phase diagram for the poly ethylene {l_brace}glycol di-methyl ether 2000 (PEGDME{sub 2000}) + Na{sub 2}HPO{sub 4} + H{sub 2}O{r_brace} system has also been determined at T = 298.15 K.

  2. Hydrogen Bonding in Phosphine Oxide/Phosphate-Phenol Complexes

    NARCIS (Netherlands)

    Cuypers, R.; Sudhölter, E.J.R.; Zuilhof, H.

    2010-01-01

    To develop a new solvent-impregnated resin (SIR) system for the removal of phenols and thiophenols from water, complex formation by hydrogen bonding of phosphine oxides and phosphates is studied using isothermal titration calorimetry (ITC) and quantum chemical modeling. Six different computational m

  3. Polaron effects in the protonic conductor hydrogen uranyl phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Lupu, D. (Inst. of Isotopic and Molecular Technology, Cluj-Napoca (Romania)); Grecu, R. (Inst. of Chemistry, Cluj-Napoca (Romania)); Biris, A.R. (Inst. of Isotopic and Molecular Technology, Cluj-Napoca (Romania))

    1993-08-01

    The isotope effects on the conductivity of hydrogen uranyl phosphate reveal ionic polaron effects in this solid protonic conductor, in agreement with the small polaron theory. An absorption band is observed at 0.67 eV, which can be correlated with the conduction mechanism consisting in both tunnelling and over-barrier hopping processes. (orig.)

  4. A facile synthesis of ω-aminoalkyl ammonium hydrogen phosphates

    Institute of Scientific and Technical Information of China (English)

    Wei Bo Kong; Xiao Yong Zhou; Yang Yang; Xing Yi Xie

    2012-01-01

    A series of ω-aminoalkyl ammonium hydrogen phosphates were synthesized through a simple and efficient three-step method.The starting materials,ω-aminoalkyl alcohols (AC-n,with carbon number n =3,4,5,6),were amino-protected with 9-fluorenylmethyl chloroformate (Fmoc-Cl),followed by phosphorylation with POCl3 and deprotection in piperidine/DMF The structures of each intermediate and final product were confirmed by 1H NMR,FTIR and mass spectrum.The yield of each step was about 77-92%,with a total yield higher than 56%.This new method was superior in low-cost raw materials,mild reaction temperatures (0-25 ℃) and easy purification methods.

  5. Simultaneous removal of nitrate, hydrogen peroxide and phosphate in semiconductor acidic wastewater by zero-valent iron.

    Science.gov (United States)

    Yoshino, Hiroyuki; Tokumura, Masahiro; Kawase, Yoshinori

    2014-01-01

    The zero-valent iron (ZVI) wastewater treatment has been applied to simultaneous removal of nitrate, hydrogen peroxide and phosphate in semiconductor acidic wastewaters. The simultaneous removal occurs by the reactions performed due to the sequential transformation of ZVI under the acidic condition. Fortunately the solution pH of semiconductor acidic wastewaters is low which is effective for the sequential transformation of ZVI. Firstly the reduction of nitrate is taken place by electrons generated by the corrosion of ZVI under acidic conditions. Secondly the ferrous ion generated by the corrosion of ZVI reacts with hydrogen peroxide and generates ·OH radical (Fenton reaction). The Fenton reaction consists of the degradation of hydrogen peroxide and the generation of ferric ion. Finally phosphate precipitates out with iron ions. In the simultaneous removal process, 1.6 mM nitrate, 9.0 mM hydrogen peroxide and 1.0 mM phosphate were completely removed by ZVI within 100, 15 and 15 min, respectively. The synergy among the reactions for the removal of nitrate, hydrogen peroxide and phosphate was found. In the individual pollutant removal experiment, the removal of phosphate by ZVI was limited to 80% after 300 min. Its removal rate was considerably improved in the presence of hydrogen peroxide and the complete removal of phosphate was achieved after 15 min.

  6. Engineering the pentose phosphate pathway to improve hydrogen yield in recombinant Escherichia coli.

    Science.gov (United States)

    Kim, Young Mi; Cho, Han-Saem; Jung, Gyoo Yeol; Park, Jong Moon

    2011-12-01

    Among various routes for the biological hydrogen production, the NAD(P)H-dependent pentose phosphate (PP) pathway is the most efficient for the dark fermentation. Few studies, however, have focused on the glucose-6-phosphate 1-dehydrogenase, encoded by zwf, as a key enzyme activating the PP pathway. Although the gluconeogenic activity is essential for activating the PP pathway, it is difficult to enhance the NADPH production by regulating only this activity because the gluconeogenesis is robust and highly sensitive to concentrations of glucose and AMP inside the cell. In this study, the FBPase II (encoded by glpX), a regulation-insensitive enzyme in the gluconeogenic pathway, was activated. Physiological studies of several recombinant, ferredoxin-dependent hydrogenase system-containing Escherichia coli BL21(DE3) strains showed that overexpression of glpX alone could increase the hydrogen yield by 1.48-fold compared to a strain with the ferredoxin-dependent hydrogenase system only; the co-overexpression of glpX with zwf increased the hydrogen yield further to 2.32-fold. These results indicate that activation of the PP pathway by glpX overexpression-enhanced gluconeogenic flux is crucial for the increase of NAD(P)H-dependent hydrogen production in E. coli BL21(DE3).

  7. Partitioning of L-methionine in aqueous two-phase systems containing poly(propylene glycol) and sodium phosphate salts

    Energy Technology Data Exchange (ETDEWEB)

    Salabat, Alireza, E-mail: a-salabat@araku.ac.ir [Chemistry Department, Arak University, P.O. Box 38156-879, Arak (Iran, Islamic Republic of); Sadeghi, Rahmat [Department of Chemistry, University of Kurdistan, Sanandaj, Kurdistan 66135 (Iran, Islamic Republic of); Moghadam, Somayeh Tiani [Chemistry Department, Arak University, P.O. Box 38156-879, Arak (Iran, Islamic Republic of); Jamehbozorg, Bahman [Department of Chemistry, University of Kurdistan, Sanandaj, Kurdistan 66135 (Iran, Islamic Republic of)

    2011-10-15

    Highlights: > Thermodynamics parameters for partitioning of L-methionine in ATPS. > Investigation of different effects on partition coefficient of the amino acid. > Propose the best condition for L-methionine partitioning. - Abstract: The partitioning behavior of L-methionine has been studied in aqueous two-phase systems of (poly(propylene glycol) + sodium phosphate salts + H{sub 2}O) at different temperatures. The salts used were sodium di-hydrogen phosphate (NaH{sub 2}PO{sub 4}), di-sodium hydrogen phosphate (Na{sub 2}HPO{sub 4}) and tri-sodium phosphate (Na{sub 3}PO{sub 4}). The effects of tie line length, salt type, and temperature on the partition coefficient of this amino acid have been studied. In addition, thermodynamic parameters ({Delta}H{sup o}, {Delta}S{sup o} and {Delta}G{sup o}) as a function of temperature were calculated. The results showed that increasing tie line length led to decreasing of the partition coefficient. We also showed that the partition coefficients of the amino acid in the systems containing Na{sub 3}PO{sub 4} are greater than the other two salts. Moreover, it is verified that increasing temperature led to decreasing the partition coefficient. The experimental partition coefficient data are correlated using a modified virial-type model.

  8. Conversion of Oximes to Carbonyl Compounds by Triscetylpyridinium Tetrakis(oxodiperoxotungsto) Phosphate (PCWP)-mediated Oxidation with Hydrogen Peroxide

    OpenAIRE

    Toscano, Rosa M.; Gaetano Tomaselli; Antonio Rescifina; Ugo Chiacchio; Francesco P. Ballistreri

    2008-01-01

    Aromatic and aliphatic oximes have been deoximated in chloroform-water to the corresponding aldehydes with dilute hydrogen peroxide and triscetylpyridinium tetrakis (oxodiperoxotungsto) phosphate as catalyst. The presence of dipolarophiles in the reaction mixtures allows a competitive reaction that converts oximes into isoxazole and isoxazoline derivatives via the intermediate formation of nitrile oxide species.

  9. Conversion of Oximes to Carbonyl Compounds by Triscetylpyridinium Tetrakis(oxodiperoxotungsto Phosphate (PCWP-mediated Oxidation with Hydrogen Peroxide

    Directory of Open Access Journals (Sweden)

    Rosa M. Toscano

    2008-06-01

    Full Text Available Aromatic and aliphatic oximes have been deoximated in chloroform-water to the corresponding aldehydes with dilute hydrogen peroxide and triscetylpyridinium tetrakis (oxodiperoxotungsto phosphate as catalyst. The presence of dipolarophiles in the reaction mixtures allows a competitive reaction that converts oximes into isoxazole and isoxazoline derivatives via the intermediate formation of nitrile oxide species.

  10. Solvent Extraction and QSPR of Catecholamines with a Bis(2-ethlhexyl) Hydrogen Phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Yoshizuka, Kazuharu.; Fujimoto, Yuko.; Ota, Keisuke.; Inoue, Katsutoshi. [Saga University, Saga (Japan). Dept. of Applied Chemistry

    1999-02-01

    In order to develop an effective separation recess for catecholamine (CA), a basic investigation on solvent extraction of dopamine (DA), adrenaline (Ad) and noradrenaline (NA) from hydrochloric acid solution and their stripping is conducted at 30 degree C employing bis(2-ethylhexyl) hydrogen phosphate (D2EHPA) in chloroform, n-hexane and toluene as the organic diluents. From the dependencies of the distribution ratios on the concentrations of reactant species, i.e. CA, hydrogen ion and D2EHPA, it is elucidated that CA (RNH{sub 2}) is extracted with D2EHPA (HR`) according to the ion exchange mechanism, as the complex type, RNH{sub 3}R` (HR`){sub 3}, and the equilibrium constants (K{sub ex,CA}) for the extraction reactions are also evaluated. The quantitative structure property relationship (QSPR) of K{sub ex,CA} values for each organic diluent is discussed using molecular modeling with semi-empirical molecular orbital calculations considering the solvent effect. (author)

  11. Growth and characterization of calcium hydrogen phosphate dihydrate crystals from single diffusion gel technique

    Energy Technology Data Exchange (ETDEWEB)

    Rajendran, K.; Dale Keefe, C. [Department of Chemistry, Cape Breton University, Sydney, Nova Scotia (Canada)

    2010-09-15

    Calcium hydrogen phosphate dihydrate (CaHPO{sub 4}.2H{sub 2}O, CHPD) a dissolved mineral in urine is known to cause renal or bladder stones in both human and animals. Growth of CHPD or brushite using sodium metasilicate gel techniques followed by light and polarizing microscopic studies revealed its structural and morphological details. Crystal identity by powder x-ray diffraction confirmed the FT-IR and FT-Raman spectroscopic techniques as alternate methods for fast analysis of brushite crystals which could form as one type of renal stones. P-O-P asymmetric stretchings in both FT-IR (987.2, 874.1 and 792 cm{sup -1}) and FT-Raman (986.3 cm{sup -1}, 1057.6 cm{sup -1} and 875.2 cm{sup -1}) were found as characteristics of brushite crystals. Differential Scanning Calorimetry (DSC) analysis revealed brushite crystallization purity using gel method by studying their endothermic peaks. This study incorporated a multidisciplinary approach in characterizing CHPD crystals grown in vitro to help formulate prevention or dissolution strategy in controlling urinary stone growth. Initial studies with 0.2 M citric acid ions as controlling agent in the nucleation of brushite crystals further support the presented approach. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  12. Tryptophanase-catalyzed L-tryptophan synthesis from D-serine in the presence of diammonium hydrogen phosphate.

    Science.gov (United States)

    Shimada, Akihiko; Ozaki, Haruka; Saito, Takeshi; Noriko, Fujii

    2009-06-01

    Tryptophanase, an enzyme with extreme absolute stereospecificity for optically active stereoisomers, catalyzes the synthesis of l-tryptophan from l-serine and indole through a beta-substitution mechanism of the ping-pong type, and has no activity on d-serine. We previously reported that tryptophanase changed its stereospecificity to degrade d-tryptophan in highly concentrated diammonium hydrogen phosphate, (NH(4))(2)HPO(4) solution. The present study provided the same stereospecific change seen in the d-tryptophan degradation reaction also occurs in tryptophan synthesis from d-serine. Tryptophanase became active to d-serine to synthesize l-tryptophan in the presence of diammonium hydrogen phosphate. This reaction has never been reported before. d-serine seems to undergo beta-replacement via an enzyme-bonded alpha-aminoacylate intermediate to yield l-tryptophan.

  13. Tryptophanase-Catalyzed l-Tryptophan Synthesis from d-Serine in the Presence of Diammonium Hydrogen Phosphate

    OpenAIRE

    Fujii Noriko; Haruka Ozaki; Takeshi Saito; Akihiko Shimada

    2009-01-01

    Tryptophanase, an enzyme with extreme absolute stereospecificity for optically active stereoisomers, catalyzes the synthesis of L-tryptophan from L-serine and indole through a β-substitution mechanism of the ping-pong type, and has no activity on D-serine. We previously reported that tryptophanase changed its stereospecificity to degrade D-tryptophan in highly concentrated diammonium hydrogen phosphate, (NH4)2HPO4 solution. The present study provided the same stereospecific change seen in the...

  14. Tryptophanase-Catalyzed l-Tryptophan Synthesis from d-Serine in the Presence of Diammonium Hydrogen Phosphate

    OpenAIRE

    Shimada, Akihiko; Ozaki, Haruka; Saito, Takeshi; Fujii, Noriko

    2009-01-01

    Tryptophanase, an enzyme with extreme absolute stereospecificity for optically active stereoisomers, catalyzes the synthesis of l-tryptophan from l-serine and indole through a β-substitution mechanism of the ping-pong type, and has no activity on d-serine. We previously reported that tryptophanase changed its stereospecificity to degrade d-tryptophan in highly concentrated diammonium hydrogen phosphate, (NH4)2HPO4 solution. The present study provided the same stereospecific change seen in the...

  15. New hydrogen titanium phosphate sulfate electrodes for Li-ion and Na-ion batteries

    Science.gov (United States)

    Zhao, Ran; Mieritz, Daniel; Seo, Dong-Kyun; Chan, Candace K.

    2017-03-01

    NASICON-type materials with general formula AxM2(PO4)3 (A = Li or Na, M = Ti, V, and Fe) are promising candidates for Li- and Na-ion batteries due to their open three-dimensional framework structure. Here we report the electrochemical properties of hydrogen titanium phosphate sulfate, H0.4Ti2(PO4)2.4(SO4)0.6 (HTPS), a new mixed polyanion material with NASICON structure. Micron-sized HTPS aggregates with crystallite grain size of ca. 23 nm are synthesized using a sol-gel synthesis in an acidic medium. The properties of the as-synthesized HTPS, ball-milled HTPS, and samples prepared as carbon composites using an in-situ glucose decomposition reaction are investigated. A capacity of 148 mAh g-1 corresponding to insertion of 2 Li+ per formula unit is observed in the ball-milled HTPS over the potential window of 1.5-3.4 V vs. Li/Li+. Lithiation at ca. 2.8 and 2.5 V is determined to occur through filling of the M1 and M2 sites, respectively. Powder X-ray diffraction (PXRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) are used characterize the HTPS before and after cycling. Evaluation of the HTPS in a Na-ion cell is also performed. A discharge capacity of 93 mAh g-1 with sodiation at ca. 2.9 and 2.2 V vs. Na/Na+ is observed.

  16. Use of triphenyl phosphate as risk mitigant for metal amide hydrogen storage materials

    Energy Technology Data Exchange (ETDEWEB)

    Cortes-Concepcion, Jose A.; Anton, Donald L.

    2016-04-26

    A process in a resulting product of the process in which a hydrogen storage metal amide is modified by a ball milling process using an additive of TPP. The resulting product provides for a hydrogen storage metal amide having a coating that renders the hydrogen storage metal amide resistant to air, ambient moisture, and liquid water while improving useful hydrogen storage and release kinetics.

  17. The Effect of 3% Phosphate Ascorbyl Gel on Bond Strength of Composite Resin to Enamel treated with 35% Hydrogen Peroxide.

    Science.gov (United States)

    de Castro, Milena de Fátima Schalcher; Silva, Alice Carvalho; Franco, Marcela Mayana Pereira; Silva, Ana Paula Brito; Bramante, Fausto da Silva; da Silva, Monica Barros; Lima, Darlon Martins; Pereira, Adriana de Fátima Vasconcelos

    2015-05-01

    To evaluate the effect of 3% phosphate ascorbyl gel (PA) in different times onto the microshear bond strength of composite resin (CR) to bovine enamel treated with 35% hydrogen peroxide (HP). Thirty enamel blocks of bovine incisors were made and divided into 5 groups (n = 6) with three specimens per group (n = 18), according to treatment: G1= No bleaching + CR; G2 = HP + CR after 15d; G3 = HP + CR after 24 hours; G4 = HP + PA (15 min) + CR after 24 hours; G5 = HP + PA (2 hours) + CR after 24 hours. The resin cylinders were made by Tygon matrices. Microshear bond strength test was performed using universal testing machine with a 50N load at a speed of 0.5 mm/min. Fracture modes were assessed by a stereomicroscope 40 ×. Microshear bond strength values were submitted to the analysis of variance (ANOVA) one-way and Tukey test (p 0.05). Failure modes were categorized into adhesive (90%) and mixed (10%). The use of 3% phosphate ascorbyl gel for 15 minutes was able to improve bond strength of composite resin to bleached bovine enamel, but when 3% phosphate ascorbyl gel was applied during 40 minutes it negatively interfered in the adhesion of the resin to bleached bovine enamel.

  18. On the hydrates of codeine phosphate: the remarkable influence of hydrogen bonding on the crystal size.

    Science.gov (United States)

    Runčevski, Tomče; Petruševski, Gjorgji; Makreski, Petre; Ugarkovic, Sonja; Dinnebier, Robert E

    2014-07-07

    Codeine phosphate forms three hydrates and two anhydrates. The sesquihydrate and hemihydrate, which differ by one water molecule, are stable at room temperature. The influence of this molecule on the internal crystal structure and how it translates into the external crystal shape are reported.

  19. Fabrication of Carbonate Apatite Block through a Dissolution–Precipitation Reaction Using Calcium Hydrogen Phosphate Dihydrate Block as a Precursor

    Directory of Open Access Journals (Sweden)

    Kanji Tsuru

    2017-03-01

    Full Text Available Carbonate apatite (CO3Ap block, which is a bone replacement used to repair defects, was fabricated through a dissolution–precipitation reaction using a calcium hydrogen phosphate dihydrate (DCPD block as a precursor. When the DCPD block was immersed in NaHCO3 or Na2CO3 solution at 80 °C, DCPD converted to CO3Ap within 3 days. β-Tricalcium phosphate was formed as an intermediate phase, and it was completely converted to CO3Ap within 2 weeks when the DCPD block was immersed in Na2CO3 solution. Although the crystal structures of the DCPD and CO3Ap blocks were different, the macroscopic structure was maintained during the compositional transformation through the dissolution–precipitation reaction. CO3Ap block fabricated in NaHCO3 or Na2CO3 solution contained 12.9 and 15.8 wt % carbonate, respectively. The diametral tensile strength of the CO3Ap block was 2 MPa, and the porosity was approximately 57% regardless of the carbonate solution. DCPD is a useful precursor for the fabrication of CO3Ap block.

  20. {tau} - hydrogen phosphate of zirconia in sodium salt form and some of its properties; {tau} - hidrogenofosfato de zirconio en forma sodica y algunas de sus propiedades

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez V, S.M.; Ordonez R, E. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2004-07-01

    It is reported the obtaining and characterization in the sodium salt form of the {tau}-hydrogen phosphate of zirconium in sodium form, this compound it was synthesized, for a new technique developed in the laboratory of Dept. of Chemistry of the ININ. The characterization was carried out for XRD, IR, Sem and EDS the thermal gravimetric analysis is also reported. (Author)

  1. Crystal Structure And Magnetic Property of the Complex of Hydrogen-bonded Two-dimensional Layer Copper(Ⅱ) Acrylate with Trimethyl Phosphate

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@ Copper carboxylate complexes play an important role in catalysing the enzymatic activities[1-4], and the phosphate has an especial use in DNA recognition[5]. Indeed the report about copper carboxylate complexes with phosphate ligands is rare. A chain structure supramolecule [Cu2(CH2CH-COO)4(H2O)2]n has been reported recently[6], in which a Cu2(CH2CH-COO)4(H2O)2 unit is linked by four O(water)-H...O(carboxyl) hydrogen bonds with two adjacent units(Fig.1). In this work a layer structure complex {Cu2(CH2CH-COO)4(H2O)2[OP(OCH3)3]}n was synthesized by means of hydrogen-bonded assembly approach between complex [Cu2(CH2CH-COO)4(H2O)2]n with trimethyl phosphate(TMP).

  2. Hydrogen cyanide in the rhizosphere: not suppressing plant pathogens, but rather regulating availability of phosphate

    Directory of Open Access Journals (Sweden)

    Tomaž Rijavec

    2016-11-01

    Full Text Available Plant growth promoting rhizobacteria produce chemical compounds with different benefits for the plant. Among them, HCN is recognized as a biocontrol agent, based on its ascribed toxicity against plant pathogens. Based on several past studies questioning the validity of this hypothesis, we have re-addressed the issue by designing a new set of in vitro experiments, to test if HCN-producing rhizobacteria could inhibit the growth of phytopathogens. The level of HCN produced by the rhizobacteria in vitro does not correlate with the observed biocontrol effects, thus disproving the biocontrol hypothesis. We developed a new concept, in which HCN does not act as a biocontrol agent, but rather is involved in geochemical processes in the substrate (e.g. chelation of metals, indirectly increasing the availability of phosphate. Since this scenario can be important for the pioneer plants living in oligotrophic alpine environments, we inoculated HCN producing bacteria into sterile mineral sand together with germinating plants and showed that the growth of the pioneer plant French sorrel was increased on granite-based substrate. No such effect could be observed for maize, where plantlets depend on the nutrients stored in the endosperm. To support our concept, we used KCN and mineral sand and showed that mineral mobilization and phosphate release could be caused by cyanide in vitro. We propose that in oligotrophic alpine environments, and possibly elsewhere, the main contribution of HCN is in the sequestration of metals and the consequential indirect increase of nutrient availability, which is beneficial for the rhizobacteria and their plant hosts.

  3. 1,1′-Binaphthalene-2,2′-diyl hydrogen phosphate

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    Susanta K. Nayak

    2008-01-01

    Full Text Available The title compound, racemic bnppa, C20H13O4P, crystallizes with four molecules in the asymmetric unit. Two independent centrosymmetric O—H...O hydrogen-bonded tetramers, each involving two of the symmetry-independent molecules in the asymmetric unit generate the packing motif in the crystal structure. The hydrophobic parts of the tetramers connect to their neighbours via C—H...π and π–π interactions [3.899 (2, 3.895 (2 and 3.803 (2 Å within the symmetric unit, 3.851 (2, 4.000 (2, 3.988 (2 and 3.905 (2 Å across centres of symmetry].

  4. Spectrin interactions with globin chains in the presence of phosphate metabolites and hydrogen peroxide: implications for thalassaemia

    Indian Academy of Sciences (India)

    Poppy Datta; Sudipa Chakrabarty; Amit Chakrabarty; Abhijit Chakrabarti

    2007-09-01

    We have shown the differential interactions of the erythroid skeletal protein spectrin with the globin subunits of adult haemoglobin (HbA); these indicate a preference for -globin over that for -globin and intact HbA in an adenosine 5′-triphosphate (ATP)-dependent manner. The presence of Mg/ATP led to an appreciable decrease in the binding affinity of the -globin chain to spectrin and the overall yield of globin–spectrin cross-linked complexes formed in the presence of hydrogen peroxide. Similar effects were also seen in the presence of 2-,3-diphosphoglycerate (2,3 DPG), the other important phosphate metabolite of erythrocytes. The binding affinity and yield of cross-linked high molecular weight complexes (HMWCs) formed under oxidative conditions were significantly higher in -globin compared with intact haemoglobin, HbA and the -globin chain. The results of this study indicate a possible correlation of the preferential spectrin binding of the -globin chain over that of the -globin in the haemoglobin disorder -thalassaemia.

  5. Comparative study of the hydration systems formed during interactions of hydrogen phosphate dianions with putrescine, nor-putrescine and magnesium dications

    Science.gov (United States)

    Figlerowicz, M.; Utzig, E.; Alejska, M.; Bratek-Wiewiórowska, M. D.; Wiewiórowski, M.

    1997-10-01

    A comparative study of hydration systems, formed as a result of the interaction between hydrogen phosphate dianions and three naturally occurring cations (putrescine (Put), its nor-homologue (nPut) and magnesium), is presented. On the basis of X-ray data and IR, NMR and calorimetric measurements, we have determined how the structure and physicochemical properties of the cations influence the system of phosphate residue hydration. Our study demonstrates that the stability of the hydration systems depends not only on the character of the bonds used by water to link with other salt components (coordinate or hydrogen bonds), but also on the location of the water molecules in the crystal lattice. In addition, contrary to magnesium salts, the dehydration of diamine (Put and nPut) hydrogen phosphates is reversible. Both dehydration and rehydration processes take place in the solid state. During rehydration, the crystalline anhydrous salt absorbs water molecules from the atmosphere. This leads to the reconstruction of the hydrated salt structure; this means that the salt which is the product of rehydration is identical with that obtained by crystallization from water solution.

  6. Synthesis and characterization of two polyoxometalates consisting of different Cu-ligand hydrogen phosphate units

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Jinshuang; Zhao, Xiaofang; Huang, Jiao; Gong, Kaining; Han, Zhangang, E-mail: hanzg116@126.com; Zhai, Xueliang, E-mail: xlzhai253@mail.hebtu.edu.cn

    2014-03-15

    Two polyoxometalates [(Cu-mbpy){sub 4}(HPO{sub 4}){sub 2}(H{sub 2}O){sub 2}][PMo{sub 12}O{sub 40}]·H{sub 2}O (1) and [(Cu-mbpy){sub 6}(HPO{sub 4}){sub 4}][PW{sub 12}O{sub 40}]·4H{sub 2}O (2) (mbpy=4,4'-dimethyl-2,2'-dipyridyl in 1; 5,5″-dimethyl-2,2'-dipyridyl in 2) have been synthesized and characterized by IR, X-ray powder diffraction, TG analysis and electrochemical property. The structural features of 1–2 are in their cationic moieties consisting of different linkages of [Cu-mbpy]{sup 2+} and HPO{sub 4}{sup 2−} groups. In 1 four Cu-mbpy bridged by two HPO{sub 4}{sup 2−} ions form a discrete cluster with an interesting octahedron of (Cu{sub 4}P{sub 2}), while in 2 Cu-mbpy fragments are bridged by HPO{sub 4}{sup 2−} ions into 1D structure consisting of trigonal bipyramidal polyhedra of (Cu{sub 3}P{sub 2}). Photocatalytic experiments indicate that compounds 1 and 2 are actively photocatalytic for degradation of methyl orange in the presence of H{sub 2}O{sub 2} under UV light irradiation. -- Graphical abstract: Two polyoxometalate-based supramolecular compounds consisting of different linkages based on Cu-ligand and HPO{sub 4}{sup 2−} groups have been synthesized and characterized. The photocatalytic activity are studied. Highlights: • Two polyoxometalate-based supramolecular compounds consisting of different linkages based on Cu-ligand and HPO{sub 4}{sup 2−} groups have been synthesized. • Hydrogen bonding and π…π interactions play important roles in constructing crystal supramolecular frameworks. • Two compounds represent a high photocatalytic activity in the degradation of methyl orange.

  7. Effect of a new phosphorus source, magnesium hydrogen phosphate (MHP on growth, utilization of phosphorus, and physiological responses in carp Cyprinus carpio

    Directory of Open Access Journals (Sweden)

    Tae-Hyun Yoon

    2016-11-01

    Full Text Available Abstract Magnesium hydrogen phosphate (MHP, MgHPO4 recovered from swine manure was prepared as an alternative phosphorus (P source. Conventional P additives, monocalcium phosphate (MCP, dicalcium phosphate (DCP, and tricalcium phosphate (TCP were compared with the MHP in terms of growth and P availability by juvenile carp Cyprinus carpio. A basal diet as a negative control was prepared using practical feed ingredients without P supplementation to which four supplemental P sources were added at the level of 2%. Five groups of 450 fish having mean body weight of 6.5 g following 24 h fasting after 2 weeks of adaptation period were randomly distributed into each of 15 tanks (30 fish/tank. Fish were hand-fed to apparent satiety twice a day for 9 weeks. Fish fed the MHP had weight gain (WG, feed conversion ratio (FCR, protein efficiency ratio (PER, and specific growth rate (SGR comparable to those fed the MCP. Those values of both the MHP and MCP groups were significantly different (p  0.05 from other phosphate groups, fish fed the MCP and MHP retained higher P in whole body than the other groups. P availability was determined to be 93.2, 62.4, 6.1, and 98.0% for MCP, DCP, TCP, and MHP, respectively. The present results suggested that the MHP recovered from wastewater stream could be used as an alternative P source in carp diet.

  8. Glyceraldehyde-3-phosphate dehydrogenase is largely unresponsive to low regulatory levels of hydrogen peroxide in Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Sousa-Lopes Ana

    2010-12-01

    Full Text Available Abstract Background The reversible oxidation of protein SH groups has been considered to be the basis of redox regulation by which changes in hydrogen peroxide (H2O2 concentrations may control protein function. Several proteins become S-glutathionylated following exposure to H2O2 in a variety of cellular systems. In yeast, when using a high initial H2O2 dose, glyceraldehyde-3-phosphate dehydrogenase (GAPDH was identified as the major target of S-glutathionylation which leads to reversible inactivation of the enzyme. GAPDH inactivation by H2O2 functions to reroute carbohydrate flux to produce NADPH. Here we report the effect of low regulatory H2O2 doses on GAPDH activity and expression in Saccharomyces cerevisiae. Results A calibrated and controlled method of H2O2 delivery - the steady-state titration - in which cells are exposed to constant, low, and known H2O2 concentrations, was used in this study. This technique, contrary to the common bolus addition, allows determining which H2O2 concentrations trigger specific biological responses. This work shows that both in exponential- and stationary-phase cells, low regulatory H2O2 concentrations induce a large upregulation of catalase, a fingerprint of the cellular oxidative stress response, but GAPDH oxidation and the ensuing activity decrease are only observed at death-inducing high H2O2 doses. GAPDH activity is constant upon incubation with sub-lethal H2O2 doses, but in stationary-phase cells there is a differential response in the expression of the three GAPDH isoenzymes: Tdh1p is strongly upregulated while Tdh2p/Tdh3p are slightly downregulated. Conclusions In yeast GAPDH activity is largely unresponsive to low to moderate H2O2 doses. This points to a scenario where (a cellular redoxins efficiently cope with levels of GAPDH oxidation induced by a vast range of sub-lethal H2O2 concentrations, (b inactivation of GAPDH cannot be considered a sensitive biomarker of H2O2-induced oxidation in vivo

  9. Ferroelectric phase transition in hydrogen-bonded 2-aminopyridine phosphate (NC sub 4 H sub 4 NH sub 2)centre dot H sub 3 PO sub 4

    CERN Document Server

    Czapla, Z; Waskowska, A

    2003-01-01

    A new crystal of 2-aminopyridine phosphate (NC sub 4 H sub 4 NH sub 2)centre dot H sub 3 PO sub 4 has been grown and its x-ray structure and physical properties were studied. At room temperature the crystals are monoclinic, space group C2/c. The flat 2-aminopyridine cations are hydrogen bonded to the anionic [PO sub 4 ] groups. The interesting feature of the crystal structure is the three-dimensional network of hydrogen bonds including, among others, two strong, symmetrical O centre dot centre dot centre dot H, H centre dot centre dot centre dot O interactions with disordered proton locations. Symmetrically related PO sub 4 anions linked through these protons form infinite (PO sub 4) subinfinity chains along the crystal a-axis. The anomalies in the temperature dependence of the electric permittivity showed that the crystal undergoes ferroelectric phase transition at T sub c = 103.5 K. The spontaneous polarization takes place along the crystal a-axis, being parallel to the chains of the hydrogen-bonded PO sub ...

  10. Influence of Different Phosphate Concentrations on Hydrogen Production by Anaerobic Granular Sludge%不同磷酸盐浓度对厌氧颗粒污泥发酵产氢的影响研究

    Institute of Scientific and Technical Information of China (English)

    蓝伟平; 周兴求; 伍健东

    2012-01-01

    The experiments were carried out to study the fermentative bio-hydrogen production by granular sludge under conditions of different phosphate concentrations with high concentrated organic wastewater as fermentation substrate. The results showed that, the phosphate under concentration of 6 mmol · L-1 ~ 8 mmol · L-1 had a catalytic effect on hydrogen production. The maximum hydrogen content of 56. 3% was appeared at phosphate concentration of 8 mmol · L-1. The phosphate concentration, COD removal rate and effluent VFA concentrations gradually increased with the increase of phosphate concentration. But hydrogen production decreased when the phosphate concentration reached to 10 mmol · L-1, due to the imbalance of nutrition and the activity of hydrogen - producing acetic bacteria was inhibited.%实验以高浓度有机废水为发酵底物,接种颗粒污泥进行厌氧发酵制氢,研究不同磷酸盐浓度条件下的产氢效果.结果表明:当磷酸盐的浓度为6mmol·L-1~8mmol·L-1时,对有机废水制氢具有促进作用,在浓度为8mmol·L-1时,氢气含量为56.3%达到最大.随着磷酸盐浓度的增加,化学需氧量(COD)去除率和出水挥发性脂肪酸(VFA)浓度也逐步提高,但当磷酸盐浓度升至10 mmol·L-1时,由于进水营养比例失衡,产氢产乙酸菌群的活性受到抑制,产气率也因此减少.

  11. XPS evidence for structure-performance relationship in selective hydrogenation of crotonaldehyde to crotyl alcohol on platinum systems supported on natural phosphates.

    Science.gov (United States)

    Hidalgo-Carrillo, Jesús; Sebti, Jalila; Marinas, Alberto; Marinas, José M; Sebti, Said; Urbano, Francisco J

    2012-09-15

    Natural phosphates are an important natural resource in Morocco, which needs to be valorised. They can be used not only as fertilisers but also as catalysts. Here, we report for the first time on its use as support for platinum and the application of the resulting systems to the liquid-phase selective hydrogenation of an α,β-unsaturated carbonyl compound (crotonaldehyde) to the corresponding unsaturated alcohol (crotyl alcohol), a process of interest in the production of pharmaceuticals, agrochemicals and fragrances. Catalytic results are related to the surface solid structure as determined by XPS. Therefore, the most active systems showed new surface interactions as evidenced by the appearance of new P, O, Ca, F and C peaks and the shift of Pt ones to lower binding energies. Further modification of the most active system with FeCl(2) led to 70% selectivity to crotyl alcohol at 34% conversion.

  12. Urinary stone formation: Efficacy of seed extract of Ensete superbum (Roxb.) Cheesman on growth inhibition of calcium hydrogen phosphate dihydrate crystals

    Science.gov (United States)

    Diana, K. J.; George, K. V.

    2013-01-01

    The effect of aqueous seed extract of Ensete superbum (Roxb.) Cheesman on in vitro crystallization and growth patterns of calcium hydrogen phosphate dihydrate (CaHPO4·2H2O, CHPD) crystals was studied using single diffusion gel growth technique. Reduction in growth of CHPD crystals was noticed with increasing concentrations of seed extract. The morphology of CHPD or brushite crystals was studied by microscopy. The structural changes of the treated crystals were assessed by SEM, FT-IR, XRD and TGA/DTA analysis. It is expected that this multidisciplinary approach for in vitro crystallization and characterization of CHPD crystals will provide a better explanation to develop novel strategies for prevention of urinary stones.

  13. Indigo Carmine-Cu complex probe exhibiting dual colorimetric/fluorimetric sensing for selective determination of mono hydrogen phosphate ion and its logic behavior

    Science.gov (United States)

    Tavallali, Hossein; Deilamy-Rad, Gohar; Moaddeli, Ali; Asghari, Khadijeh

    2017-08-01

    A new selective probe based on copper complex of Indigo Carmine (IC-Cu2) for colorimetric, naked-eye, and fluorimetric recognition of mono hydrogen phosphate (MHP) ion in H2O/DMSO (4:1 v/v, 1.0 mmol L- 1 HEPES buffer solution pH 7.5) was developed. Detection limit of HPO42 - determination, achieved by fluorimetric and 3lorimetric method, are 0.071 and 1.46 μmol L- 1, respectively. Potential, therefore is clearly available in IC-Cu2 complex to detect HPO42 - in micromolar range via dual visible color change and fluorescence response. Present method shows high selectivity toward HPO42 - over other phosphate species and other anions and was successfully utilized for analysis of P2O5 content of a fertilizer sample. The results obtained by proposed chemosensor presented good agreement with those obtained the colorimetric reference method. INHIBIT and IMPLICATION logic gates operating at molecular level have been achieved using Cu2 + and HPO42 - as chemical inputs and UV-Vis absorbance signal as output.

  14. Hydrogen.

    Science.gov (United States)

    Bockris, John O'M

    2011-11-30

    The idea of a "Hydrogen Economy" is that carbon containing fuels should be replaced by hydrogen, thus eliminating air pollution and growth of CO₂ in the atmosphere. However, storage of a gas, its transport and reconversion to electricity doubles the cost of H₂ from the electrolyzer. Methanol made with CO₂ from the atmosphere is a zero carbon fuel created from inexhaustible components from the atmosphere. Extensive work on the splitting of water by bacteria shows that if wastes are used as the origin of feed for certain bacteria, the cost for hydrogen becomes lower than any yet known. The first creation of hydrogen and electricity from light was carried out in 1976 by Ohashi et al. at Flinders University in Australia. Improvements in knowledge of the structure of the semiconductor-solution system used in a solar breakdown of water has led to the discovery of surface states which take part in giving rise to hydrogen (Khan). Photoelectrocatalysis made a ten times increase in the efficiency of the photo production of hydrogen from water. The use of two electrode cells; p and n semiconductors respectively, was first introduced by Uosaki in 1978. Most photoanodes decompose during the photoelectrolysis. To avoid this, it has been necessary to create a transparent shield between the semiconductor and its electronic properties and the solution. In this way, 8.5% at 25 °C and 9.5% at 50 °C has been reached in the photo dissociation of water (GaP and InAs) by Kainthla and Barbara Zeleney in 1989. A large consortium has been funded by the US government at the California Institute of Technology under the direction of Nathan Lewis. The decomposition of water by light is the main aim of this group. Whether light will be the origin of the post fossil fuel supply of energy may be questionable, but the maximum program in this direction is likely to come from Cal. Tech.

  15. An Innovative Approach to Treat Incisors Hypomineralization (MIH: A Combined Use of Casein Phosphopeptide-Amorphous Calcium Phosphate and Hydrogen Peroxide—A Case Report

    Directory of Open Access Journals (Sweden)

    Stefano Mastroberardino

    2012-01-01

    Full Text Available Molar Incisor Hypomineralization (MIH is characterized by a developmentally derived deficiency in mineral enamel. Affected teeth present demarcated enamel opacities, ranging from white to brown; also hypoplasia can be associated. Patient frequently claims aesthetic discomfort if anterior teeth are involved. This problem leads patients to request a bleaching treatment to improve aestheticconditions.Nevertheless, hydrogen peroxide can produce serious side-effects, resulting from further mineral loss. Microabrasion and/or a composite restoration are the treatments of choice in teeth with mild/moderate MIH, but they also need enamel loss. Recently, a new remineralizing agent based on Casein Phosphopeptide-Amorphous Calcium Phosphate (CPP-ACP has been proposed to be effective in hypomineralized enamel, improving also aesthetic conditions. The present paper presents a case report of a young man with white opacities on incisors treated with a combined use of CPP-ACP mousse and hydrogen peroxide gel to correct the aesthetic defect. The patient was instructed to use CPP-ACP for two hours per day for three months in order to obtain enamel remineralization followed by a combined use of CPP-ACP and bleaching agent for further two months. At the end of this five-month treatment, a noticeable aesthetic improvement of the opacities was observed.

  16. An Innovative Approach to Treat Incisors Hypomineralization (MIH): A Combined Use of Casein Phosphopeptide-Amorphous Calcium Phosphate and Hydrogen Peroxide-A Case Report.

    Science.gov (United States)

    Mastroberardino, Stefano; Campus, Guglielmo; Strohmenger, Laura; Villa, Alessandro; Cagetti, Maria Grazia

    2012-01-01

    Molar Incisor Hypomineralization (MIH) is characterized by a developmentally derived deficiency in mineral enamel. Affected teeth present demarcated enamel opacities, ranging from white to brown; also hypoplasia can be associated. Patient frequently claims aesthetic discomfort if anterior teeth are involved. This problem leads patients to request a bleaching treatment to improve aestheticconditions.Nevertheless, hydrogen peroxide can produce serious side-effects, resulting from further mineral loss. Microabrasion and/or a composite restoration are the treatments of choice in teeth with mild/moderate MIH, but they also need enamel loss. Recently, a new remineralizing agent based on Casein Phosphopeptide-Amorphous Calcium Phosphate (CPP-ACP) has been proposed to be effective in hypomineralized enamel, improving also aesthetic conditions. The present paper presents a case report of a young man with white opacities on incisors treated with a combined use of CPP-ACP mousse and hydrogen peroxide gel to correct the aesthetic defect. The patient was instructed to use CPP-ACP for two hours per day for three months in order to obtain enamel remineralization followed by a combined use of CPP-ACP and bleaching agent for further two months. At the end of this five-month treatment, a noticeable aesthetic improvement of the opacities was observed.

  17. Reduction of Oxygen Bound with Hemoglobin by Electrolytic Method Using Hydrogen Gas in Phosphate-buffered Solution

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Hemoglobin(Hb) is important as an oxygen carrier.The trace amount of oxygen in Hb was reduced by an electrolytic method using hydrogen as an electron donor.The deoxygenated Hb(deoxyHb) was stable against heat treatment at 60 ℃ with little precipitant.This method is safe,fast,and would be of potential use for large scale purification of Hb.

  18. Hydrogen

    Directory of Open Access Journals (Sweden)

    John O’M. Bockris

    2011-11-01

    Full Text Available The idea of a “Hydrogen Economy” is that carbon containing fuels should be replaced by hydrogen, thus eliminating air pollution and growth of CO2 in the atmosphere. However, storage of a gas, its transport and reconversion to electricity doubles the cost of H2 from the electrolyzer. Methanol made with CO2 from the atmosphere is a zero carbon fuel created from inexhaustible components from the atmosphere. Extensive work on the splitting of water by bacteria shows that if wastes are used as the origin of feed for certain bacteria, the cost for hydrogen becomes lower than any yet known. The first creation of hydrogen and electricity from light was carried out in 1976 by Ohashi et al. at Flinders University in Australia. Improvements in knowledge of the structure of the semiconductor-solution system used in a solar breakdown of water has led to the discovery of surface states which take part in giving rise to hydrogen (Khan. Photoelectrocatalysis made a ten times increase in the efficiency of the photo production of hydrogen from water. The use of two electrode cells; p and n semiconductors respectively, was first introduced by Uosaki in 1978. Most photoanodes decompose during the photoelectrolysis. To avoid this, it has been necessary to create a transparent shield between the semiconductor and its electronic properties and the solution. In this way, 8.5% at 25 °C and 9.5% at 50 °C has been reached in the photo dissociation of water (GaP and InAs by Kainthla and Barbara Zeleney in 1989. A large consortium has been funded by the US government at the California Institute of Technology under the direction of Nathan Lewis. The decomposition of water by light is the main aim of this group. Whether light will be the origin of the post fossil fuel supply of energy may be questionable, but the maximum program in this direction is likely to come from Cal. Tech.

  19. The role of hydrogen bonding in the thermal expansion and dehydration of brushite, di-calcium phosphate dihydrate

    Science.gov (United States)

    Schofield, P. F.; Knight, K. S.; Houwen, J. A. M. Van Der; Valsami-Jones, E.

    2004-12-01

    The unit-cell and atomic parameters of perdeuterated brushite have been extracted from Rietveld analysis of neutron powder diffraction data within the temperature range 4.2 to 470 K. The thermal expansion of brushite is anisotropic, with the largest expansion along the b axis due principally to the effect of the O(1)···D(4) and O(3)···D(2) hydrogen bonds. Expansion along the c axis, influenced by the Ow1···D(5) interwater hydrogen bond, is also large. The high temperature limits for the expansion coefficients for the unit-cell edges a, b and c are 9.7(5) × 10-6, 3.82(9) × 10-5 and 5.54(5) × 10-5 K-1, respectively, and for the cell volume it is 9.7(1) × 10-5 K-1. The β angle displays oscillatory variation, and empirical data analysis results in αβ = 1.28(3) × 10-6sin(0.0105 T) K-1, within this temperature range. The evolution of the thermal expansion tensor of brushite has been calculated between 50 ≤T≤ 400 K. At 300 K the magnitudes of the principal axes are α11 = 50(6) × 10-6 K-1, α22 = 26.7(7) × 10-6 K-1 and α33 = 7.0(5) × 10-6 K-1. The intermediate axis, α22, is parallel to b, and using IRE convention for the tensor orthonormal basis, the axes α11 and α33 have directions equal to (-0.228, 0, -0.974) and (-0.974, 0, 0.228) respectively. Under the conditions of these experiments, the onset of dehydration occurred at temperatures above 400 K. Bond valence analysis combined with assessments of the thermal evolution of the bonding within brushite suggests that dehydration is precipitated through instabilities in the chemical environment of the second water molecule.

  20. Co-production of hydrogen and ethanol from glucose by modification of glycolytic pathways in Escherichia coli - from Embden-Meyerhof-Parnas pathway to pentose phosphate pathway.

    Science.gov (United States)

    Seol, Eunhee; Sekar, Balaji Sundara; Raj, Subramanian Mohan; Park, Sunghoon

    2016-02-01

    Hydrogen (H2) production from glucose by dark fermentation suffers from the low yield. As a solution to this problem, co-production of H2 and ethanol, both of which are good biofuels, has been suggested. To this end, using Escherichia coli, activation of pentose phosphate (PP) pathway, which can generate more NADPH than the Embden-Meyhof-Parnas (EMP) pathway, was attempted. Overexpression of two key enzymes in the branch nodes of the glycolytic pathway, Zwf and Gnd, significantly improved the co-production of H2 and ethanol with concomitant reduction of pyruvate secretion. Gene expression analysis and metabolic flux analysis (MFA) showed that, upon overexpression of Zwf and Gnd, glucose assimilation through the PP pathway, compared with that of the EMP or Entner-Doudoroff (ED) pathway, was greatly enhanced. The maximum co-production yields were 1.32 mol H2 mol(-1) glucose and 1.38 mol ethanol mol(-1) glucose, respectively. It is noteworthy that the glycolysis and the amount of NAD(P)H formed under anaerobic conditions could be altered by modifying (the activity of) several key enzymes. Our strategy could be applied for the development of industrial strains for biological production of reduced chemicals and biofuels which suffers from lack of reduced co-factors.

  1. A Raman spectroscopic study of the mono-hydrogen phosphate mineral dorfmanite Na 2(PO 3OH)·2H 2O and in comparison with brushite

    Science.gov (United States)

    Frost, Ray L.; Palmer, Sara J.; Xi, Yunfei

    2011-11-01

    Aspects of the molecular structure of the mineral dorfmanite Na 2(PO 3OH)·2H 2O were determined by Raman spectroscopy. The mineral originated from the Kedykverpakhk Mt., Lovozero, Kola Peninsula, Russia. Raman bands are assigned to the hydrogen phosphate units. The intense Raman band at 949 cm -1 and the less intense band at 866 cm -1 are assigned to the PO 3 and POH stretching vibrations. Bands at 991, 1066 and 1141 cm -1 are assigned to the ν3 antisymmetric stretching modes. Raman bands at 393, 413 and 448 cm -1 and 514, 541 and 570 cm -1 are attributed to the ν2 and ν4 bending modes of the HPO 4 units, respectively. Raman bands at 3373, 3443 and 3492 cm -1 are assigned to water stretching vibrations. POH stretching vibrations are identified by bands at 2904, 3080 and 3134 cm -1. Raman spectroscopy has proven very useful for the study of the structure of the mineral dorfmanite.

  2. Effect of Cd⁺² on phosphate solubilizing abilities and hydrogen peroxide production of soil-borne micromycetes isolated from Phragmites australis-rhizosphere.

    Science.gov (United States)

    Zúñiga-Silva, Jose Roberto; Chan-Cupul, Wilberth; Kuschk, Peter; Loera, Octavio; Aguilar-López, Ricardo; Rodríguez-Vázquez, Refugio

    2016-03-01

    The aims of this work were to evaluate the phosphate-solubilization and hydrogen peroxide (H2O2) production by the soil-borne micromycetes, Aspergillus japonicus, Penicillium italicum and Penicillium dipodomyicola, isolated from Phragmites australis rhizosphere and to study the effect of several concentrations of Cadmium (Cd(2+)) on both variables. Our results showed that P. italicum achieved a higher P-solubilization and H2O2 production than A. japonicus and P. dipodomyicola, as only P. italicum showed a positive correlation (R(2) = 0.71) between P-solubilization and H2O2 production. In dose-response assays, P. italicum was also more tolerant to Cd(2+) (0.31 mM) in comparison to A. japonicus (0.26 mM). Analysis of the 2(4) factorial experimental design showed that P-solubilization by P. italicum was negatively affected by increases in Cd(2+) (p = 0.04) and yeast extract (p = 0.02) in the culture medium. The production of H2O2 was positively affected only by glucose (p = 0.002). Fungal biomass production was reduced significantly (p = 0.0009) by Cd(2+) and increased (p = 0.0003) by high glucose concentration in the culture medium. The tolerance and correlation between P-solubilization and H2O2 production in the presence of Cd(2+) was strain and species dependent. The effects of Cd(2+), glucose, ammonium sulfate and yeast extract on those variables were evaluated through a two-level factorial design. P. italicum is promising for P-solubilization in soils contaminated with Cd(2+) and may be an alternative for manufacture of biofertilizers to replace chemical fertilizers.

  3. Correlation of biological value of feed phosphates with their solubility in water, dilute hydrogen chloride, dilute citric acid, and neutral ammonium citrate.

    Science.gov (United States)

    Sullivan, T W; Douglas, J H; Gonzalez, N J; Bond, P L

    1992-12-01

    Relative biological values (BV) of 36 feed phosphates were determined with female turkeys in bioassays of 21-day duration using three response criteria: weight gain, tibia ash percentage, and gain:feed ratio. Calcium phosphate, dibasic dihydrate (United States Pharmacopeia) was the reference standard. Nine mono-dicalcium phosphates (M-DCP, 21.0% phosphorus), 13 di-monocalcium phosphates (D-MCP, 18.5% phosphorus), and 14 defluorinated phosphates (DFP, 18.0% phosphorus) were evaluated. The average relative BV for M-DCP, D-MCP, and DFP samples were 97.6, 94.6, and 90.8%, respectively. Solubility of phosphates was determined by four recognized methods. The solvents were water, .4% HCl, 2.0% citric acid (CA), and neutral ammonium citrate (NAC). Water solubility of M-DCP samples was greater (67.5%) than that of D-MCP (38.8%) and DFP (8.9%) samples. Correlation of water solubility of phosphates to their relative BV was quite low, and water solubility was a poor indicator of BV. When .4% HCl was the solvent, correlation coefficients (r) were .55, .33, and .72 for M-DCP, D-MCP, and DFP, respectively. Based on these results and prediction equations, .4% HCl solubility would be inappropriate for estimating BV of M-DCP and D-MCP samples. Solubility of feed phosphates (mainly D-MCP and DFP) in 2.0% CA or NAC was positively correlated with BV; the r values were .87 to .95. Both of these solubility tests provided a good index of BV. However, it would seem inappropriate and risky to replace bioassays totally with these tests. Feed phosphate users could perform either the 2.0% CA or NAC solubility test easily as a screen for BV along with other quality control procedures (i.e., phosphorus, calcium, sodium, and fluoride determinations).

  4. Significantly Dense Two-Dimensional Hydrogen-Bond Network in a Layered Zirconium Phosphate Leading to High Proton Conductivities in Both Water-Assisted Low-Temperature and Anhydrous Intermediate-Temperature Regions.

    Science.gov (United States)

    Gui, Daxiang; Zheng, Tao; Xie, Jian; Cai, Yawen; Wang, Yaxing; Chen, Lanhua; Diwu, Juan; Chai, Zhifang; Wang, Shuao

    2016-12-19

    A highly stable layered zirconium phosphate, (NH4)2[ZrF2(HPO4)2] (ZrP-1), was synthesized by an ionothermal method and contains an extremely dense two-dimensional hydrogen-bond network that is thermally stable up to 573 K, leading to combined ultrahigh water-assisted proton conductivities of 1.45 × 10(-2) S cm(-1) at 363 K/95% relative humidity and sustainable anhydrous proton conductivity of 1.1 × 10(-5) S cm(-1) at 503 K.

  5. Sodium Phosphate

    Science.gov (United States)

    Sodium phosphate is used in adults 18 years of age or older to empty the colon (large intestine, bowel) ... view of the walls of the colon. Sodium phosphate is in a class of medications called saline ...

  6. Phosphate salts

    Science.gov (United States)

    ... levels that are too high, and for preventing kidney stones. They are also taken for treating osteomalacia (often ... But intravenous phosphate salts should not be used. Kidney stones (nephrolithiasis). Taking potassium phosphate by mouth might help ...

  7. Administration of Poly[di(sodium carboxylatoethylphenoxy)phosphazene] (PCEP) and Avian Beta Defensin as Adjuvants in Inactivated Inclusion Body Hepatitis Virus and its Hexon Protein-Based Experimental Vaccine Formulations in Chickens.

    Science.gov (United States)

    Dar, Arshud; Tipu, Masroor; Townsend, Hugh; Potter, Andy; Gerdts, Volker; Tikoo, Suresh

    2015-12-01

    Inclusion body hepatitis (IBH) is one of the major infectious diseases adversely affecting the poultry industry of the United States and Canada. Currently, no effective and safe vaccine is available for the control of IBH virus (IBHV) infection in chickens. However, based on the excellent safety and immunogenic profiles of experimental veterinary vaccines developed with the use of new generation adjuvants, we hypothesized that characterization of vaccine formulations containing inactivated IBHV or its capsid protein hexon as antigens, along with poly[di(sodium carboxylatoethylphenoxy)phosphazene] (PCEP) and avian beta defensin 2 (ABD2) as vaccine adjuvants, will be helpful in development of an effective and safe vaccine formulation for IBH. Our data demonstrated that experimental administration of vaccine formulations containing inactivated IBHV and a mixture of PCEP with or without ABD2 as an adjuvant induced significantly higher antibody responses compared with other vaccine formulations, while hexon protein-based vaccine formulations showed relatively lower levels of antibody responses. Thus, a vaccine formulation containing inactivated IBHV with PCEP or a mixture of PCEP and ABD2 (with a reduced dosage of PCEP) as an adjuvant may serve as a potential vaccine candidate. However, in order to overcome the risks associated with whole virus inactivated vaccines, characterization of additional viral capsid proteins, including fiber protein and penton of IBHV along with hexon protein in combination with more new generation adjuvants, will be helpful in further improvements of vaccines against IBHV infection.

  8. Effects of Dietary Supplementation of Magnesium Hydrogen Phosphate (MgHPO4) as an Alternative Phosphorus Source on Growth and Feed Utilization of Juvenile Far Eastern Catfish (Silurus asotus).

    Science.gov (United States)

    Yoon, Tae-Hyun; Lee, Dong-Hoon; Won, Seung-Gun; Ra, Chang-Six; Kim, Jeong-Dae

    2014-08-01

    The present study was conducted to investigate a supplemental effect of magnesium hydrogen phosphate (MHP, MgHPO4) as an alternative phosphorus (P) source on growth and feed utilization of juvenile far eastern catfish (Silurus asotus) in comparison with three conventional P additives (monocalcium phosphate (MCP), dicalcium phosphate (DCP) and tricalcium phosphate [TCP]) as positive controls. A basal diet as a negative control was prepared without P supplementation and four supplemental P sources were added at the level of 2%. Five groups of 450 fish having mean body weight of 11.3 g following 24 h fasting after three week adaptation period were randomly distributed into each of 15 tanks (30 fish/tank). Fish were hand-fed to apparent satiety twice a day for 8 weeks. Fish fed MHP had weight gain (WG), protein efficiency ratio and specific growth rate comparable to those fed MCP. Fish fed MHP and MCP had feed efficiency (FE) significantly higher (pDCP. Fish groups fed control and TCP showed the lower FE than the other groups which was significantly different (p0.05) among treatments. Fish fed control had the lowest hematocrit, which was significantly different (pDCP and TCP to MHP were found to be 100.5 and 101.3%, 92.0 and 91.6%, and 79.1 and 80.9% for WG and FE, respectively. P availability was determined to be 88.1%, 75.2%, 8.7%, and 90.9% for MCP, DCP, TCP, and MHP, respectively. Consequently, MHP recovered from wastewater stream showed that as an alternative P source its performance was comparative with MCP on growth and feed utilization of juvenile far eastern catfish.

  9. Predicting laser-induced bulk damage and conditioning for deuterated potassium di-hydrogen phosphate crystals using ADM (absorption distribution model)

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Z M; Spaeth, M L; Manes, K; Adams, J J; Carr, C W

    2010-02-26

    We present an empirical model that describes the experimentally observed laser-induced bulk damage and conditioning behavior in deuterated Potassium dihydrogen Phosphate (DKDP) crystals in a self-consistent way. The model expands on an existing nanoabsorber precursor model and the multi-step absorption mechanism to include two populations of absorbing defects, one with linear absorption and another with nonlinear absorption. We show that this model connects previously uncorrelated small-beam damage initiation probability data to large-beam damage density measurements over a range of ns pulse widths relevant to ICF lasers such as the National Ignition Facility (NIF). In addition, this work predicts the damage behavior of laser-conditioned DKDP and explains the upper limit to the laser conditioning effect. The ADM model has been successfully used during the commissioning and early operation of the NIF.

  10. The influenza fusion peptide promotes lipid polar head intrusion through hydrogen bonding with phosphates and N-terminal membrane insertion depth.

    Science.gov (United States)

    Légaré, Sébastien; Lagüe, Patrick

    2014-09-01

    Influenza infection requires fusion between the virus envelope and a host cell endosomal membrane. The influenza hemagglutinin fusion peptide (FP) is essential to viral membrane fusion. It was recently proposed that FPs would fuse membranes by increasing lipid tail protrusion, a membrane fusion transition state. The details of how FPs induce lipid tail protrusion, however, remain to be elucidated. To decipher the molecular mechanism by which FPs promote lipid tail protrusion, we performed molecular dynamics simulations of the wild-type (WT) FP, fusogenic mutant F9A, and nonfusogenic mutant W14A in model bilayers. This article presents the peptide-lipid interaction responsible for lipid tail protrusion and a related lipid perturbation, polar head intrusion, where polar heads are sunk under the membrane surface. The backbone amides from the four N-terminal peptide residues, deeply inserted in the membrane, promoted both perturbations through H bonding with lipid phosphates. Polar head intrusion correlated with peptides N-terminal insertion depth and activity: the N-termini of WT and F9A were inserted deeper into the membrane than nonfusogenic W14A. Based on these results, we propose that FP-induced polar head intrusion would complement lipid tail protrusion in catalyzing membrane fusion by reducing repulsions between juxtaposed membranes headgroups. The presented model provides a framework for further research on membrane fusion and influenza antivirals.

  11. Determination of the stability of the uranyl ion sipped in {tau}-hydrogen phosphate of zirconium in sodic form; Determinacion de la estabilidad del ion uranilo sorbido en {tau}-hidrogenofosfato de zirconio en forma sodica

    Energy Technology Data Exchange (ETDEWEB)

    Ordonez R, E.; Fernandez V, S.M. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Drot, R.; Simoni, E. [Universite de Paris-Sud-XI, Institut de Physique Nucleaire d' Orsay, Groupe de radiochimie, Bat. 100, 91406 Orsay (France)]. e-mail: edo@nuclear.inin.mx

    2005-07-01

    The stability of the uranyl sipped in the zirconium {tau}-hydrogen phosphate in sodic form ({tau}-NaZrP), was carried out characterizing the complexes formed by Laser spectroscopy in the visible region and by X-ray photoelectron spectroscopy. The material was prepared by a new synthesis technique working in nitrogen atmosphere and to low temperatures. The sorption of the uranyl ion was made in acid media with concentrations of 10{sup -4} and 10{sup -5} of uranyl nitrate and with ion forces of 0.1 and 0.5 M of NaClO{sub 4}. The spectra of induced fluorescence with laser (TRLFS) show that the uranyl is fixed in very acid media in three well differentiated species, to pH less acid, the specie of long half life disappears and are only those of short half life. The results of the binding energy obtained by XPS indicate that the binding energy of the uranyl confer it a stable character to the complex formed in the {tau}-NaZP, that makes to this material appropriate to retain to the uranyl in solution to high ion forces and in acid media. (Author)

  12. Stimulation of d- and l-lactate dehydrogenases transcriptional levels in presence of diammonium hydrogen phosphate resulting to enhanced lactic acid production by Lactobacillus strain.

    Science.gov (United States)

    Singhvi, Mamata; Zendo, Takeshi; Iida, Hiroshi; Gokhale, Digambar; Sonomoto, Kenji

    2017-08-08

    The present study revealed the effect of nitrogen sources on lactic acid production and stimulation of d- and l-lactate dehydrogenases (LDH) of parent Lactobacillus lactis NCIM 2368 and its mutant RM2-24 generated after UV mutagenesis. Both the parent and mutant strains were evaluated for d-lactic acid production in control and modified media. The modified media did not show remarkable effect on lactic acid production in case of parent whereas mutant exhibited significant enhancement in d-lactic acid production along with the appearance of l-lactic acid in the broth. Both LDH activities and specific activities were found to be higher in mutant than the parent strain. These results suggested that the diammonium hydrogen phosphate in modified media triggered the expression of LDH genes leading to enhanced lactic acid production. This observation has been proved by studying the expression levels of d- and l-LDH genes of parent and mutant in control and modified media using quantitative RT-PCR technique. In case of mutant, the transcriptional levels of d-LDH and l-LDH increased ∼17 fold and ∼1.38 fold respectively in modified medium compared to the values obtained with control medium. In case of parent, no significant change in transcriptional levels of d- and l-LDH was found when the cells were grown in either control medium or modified medium. This study suggested that the mutant, RM2-24 has l-LDH gene which is expressed in presence of (NH4)2HPO4 resulting in l-lactic acid production. Co-production of l-lactic acid in d-lactic acid fermentation may be detrimental in the PLA production. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  13. Fluorescence sensor for sequential detection of zinc and phosphate ions

    Science.gov (United States)

    An, Miran; Kim, Bo-Yeon; Seo, Hansol; Helal, Aasif; Kim, Hong-Seok

    2016-12-01

    A new, highly selective turn-on fluorescent chemosensor based on 2-(2‧-tosylamidophenyl)thiazole (1) for the detection of zinc and phosphate ions in ethanol was synthesized and characterized. Sensor 1 showed a high selectivity for zinc compared to other cations and sequentially detected hydrogen pyrophosphate and hydrogen phosphate. The fluorescence mechanism can be explained by two different mechanisms: (i) the inhibition of excited-state intramolecular proton transfer (ESIPT) and (ii) chelation-induced enhanced fluorescence by binding with Zn2 +. The sequential detection of phosphate anions was achieved by the quenching and subsequent revival of ESIPT.

  14. Phosphate homeostasis and disorders.

    Science.gov (United States)

    Manghat, P; Sodi, R; Swaminathan, R

    2014-11-01

    Recent studies of inherited disorders of phosphate metabolism have shed new light on the understanding of phosphate metabolism. Phosphate has important functions in the body and several mechanisms have evolved to regulate phosphate balance including vitamin D, parathyroid hormone and phosphatonins such as fibroblast growth factor-23 (FGF23). Disorders of phosphate homeostasis leading to hypo- and hyperphosphataemia are common and have clinical and biochemical consequences. Notably, recent studies have linked hyperphosphataemia with an increased risk of cardiovascular disease. This review outlines the recent advances in the understanding of phosphate homeostasis and describes the causes, investigation and management of hypo- and hyperphosphataemia.

  15. [Effects of Phosphate and Zeolite on the Transformation of Cd Speciation in Soil].

    Science.gov (United States)

    Wang, Xiu-li; Liang, Cheng-hua; Ma, Zi-hui; Han, Yue

    2015-04-01

    The test simulated exogenous Cd contaminated soil indoors, and studied separate application of potassium dihydrogen phosphate, diammonium hydrogen phosphate and zeolite, and combined application of zeolite and dipotassium hydrogen phosphate, zeolite and diammonium hydrogen phosphate, as well as the effect on the morphological changes of Cd contaminated soil. The results showed that soil exchangeable Cd contents were reduced in different degrees after the application of different modifiers, and the carbonate bound and Fe-Mn oxide bound, organic bound and residual Cd contents increased. By comparison, the separate application of potassium dihydrogen phosphate, diammonium hydrogen phosphate and zeolite, and the combined application of zeolite and dipotassium hydrogen phosphate, zeolite and diammonium hydrogen phosphate respectively reduced the soil available Cd contents at 25.2% -51.7%, 21.6% - 46.8%, 6.4% - 23.2%, 38.6% - 61.4%, and 34.1% - 56.4%. All treatments could increase the soil available phosphorus contents, making the soil available phosphorus contents negatively correlated with the available Cd contents significantly, with the correlation coefficient r = - 0.902 6, and the soil pH values had a negative correlation with the available Cd content during the treatments. Therefore, it could be known that the changes of soil available phosphorus contents were the major factor in reducing the availability of soil cadmium under the conditions of the application of phosphate and natural zeolite.

  16. S-Transnitrosation reactions of hydrogen sulfide (H2S/HS(-)/S(2-)) with S-nitrosated cysteinyl thiols in phosphate buffer of pH 7.4: Results and review of the literature.

    Science.gov (United States)

    Tsikas, Dimitrios; Böhmer, Anke

    2017-05-01

    Cysteine (CysSH) and its derivatives including N-acetylcysteine (NAC) and glutathione (GSH), and cysteine residues in proteins and enzymes are nitrosated with nitric oxide (NO) reaction products such as N2O3 to form S-nitrosated cysteine thiols (RCysSNO). RCysSNO undergo with cysteine thiols (RCysSH) S-transnitrosation reactions, thereby transferring reversibly their nitrosyl ((+)NO) group to RCysSH to form RCysSNO. (•)NO release from RCysSNO and S-transnitrosation are considered the most important features and signalling pathways of RCysSNO. Hydrogen sulfide (H2S: pKa1, 7; HS(-): pKa2, 12.9) is an endogenous product of cysteine metabolism. We hypothesized that RCysSNO would also undergo S-transnitrosation reaction with H2S/HS(-)/S(2-) to form thionitrite (ONS(-)), the smallest S-nitrosated thiol. This article describes spectrophotometric and mass spectrometric investigations of S-transnitrosation reactions in phosphate buffered saline (PBS) of pH 7.4 between H2S/HS(-)/S(2-) (supplied as Na2S) and S-nitrosoglutathione (GSNO), S-nitroso-l-cysteine (CysSNO), S-nitroso-N-acetyl-l-cysteine (SNAC), and the synthetic S-nitroso-N-acetyl-l-cysteine ethyl ester (SNACET). For comparison, we also investigated the reactions of H2S/HS(-)/S(2-) with NO(+)BF4(-) and NO2(+)BF4(-), direct ON(+) and O2N(+) donors, respectively, and assumed formation of ONS(-) and thionitrate (O2NS(-)), respectively. Addition of Na2S (at 1 mM) to buffered RCysSNO solutions resulted in decreases of the absorbance at 340 nm and concomitant increases in the absorbance at 410 nm depending upon the nature and concentration of RCysSNO (range, 25-1000 μM). The reactivity order of RCysSNO against H2S/HS(-)/S(2-) was: CysSNO > SNACET > GSNO > SNAC. Our spectrophotometric and GC-MS analyses indicate that H2S/HS(-)/S(2-) and RCysSNO undergo multiple reactions. Major final reaction products were found to be nitrite and nitrate. ONS(-) and O2NS(-) were not detected by GC-MS, suggesting rapid and

  17. Dihydrogen Phosphate Selective Anion Receptor Based on Acylhydrazone

    Energy Technology Data Exchange (ETDEWEB)

    Senthil Pandian, T.; Kang, Jongmin [Sejong Univ., Seoul (Korea, Republic of)

    2014-07-15

    Anion receptor based on acylhydrazone has been designed and synthesized. UV-vis and {sup 1}H NMR titration showed that receptor is selective receptor for dihydrogen phosphate (H{sub 2}PO{sub 4}{sup -}). Dihydrogen phosphate was complexed by the receptor via at least 4 hydrogen bonding interactions, contributing from two amide N-Hs and two imine C-Hs. In addition, nitrogen in the aromatic ring could make 2 additional hydrogen bondings with OH groups in the dihydrogen phosphate. However, the receptor could make only 4 hydrogen bonds with halides. Therefore, receptor could bind anions through hydrogen bonds with a selectivity in the order of H{sub 2}PO{sub 4}{sup -} > Br{sup -} > Cl{sup -} in highly polar solvent such as DMSO.

  18. Chloroquine Phosphate Oral

    Science.gov (United States)

    Chloroquine phosphate is in a class of drugs called antimalarials and amebicides. It is used to prevent and treat ... Chloroquine phosphate comes as a tablet to take by mouth. For prevention of malaria in adults, one dose is ...

  19. Glucose-6-phosphate dehydrogenase

    Science.gov (United States)

    ... medlineplus.gov/ency/article/003671.htm Glucose-6-phosphate dehydrogenase test To use the sharing features on this page, please enable JavaScript. Glucose-6-phosphate dehydrogenase (G6PD) is a protein that helps red ...

  20. Isotherms and kinetic study of dihydrogen and hydrogen phosphate ions (H{2}PO{4}- and HPO{4}2-) adsorption onto crushed plant matter of the semi-arid zones of Morocco: Asphodelus microcarpus, Asparagus albus and Senecio anthophorbium

    Science.gov (United States)

    Chiban, M.; Benhima, H.; Saadi, B.; Nounah, A.; Sinan, F.

    2005-03-01

    In the present work H{2}PO4- and HPO42- ions adsorption onto organic matter (OM) obtained from ground dried three plants growing in arid zones of Morocco has been studied. The adsorption process is affected by various parameters such as contact time, particle size and initial concentration of phosphate solution (Ci ≤ 30 mg/l). The uptake of both ions is increased by increasing the concentration of them selves. The retention of phosphate ions by Asphodelus microcarpus, Asparagus albus are well defined by several isotherms such as the Langmuir, Temkin and Freundlich.

  1. Why nature chose phosphates.

    Science.gov (United States)

    Westheimer, F H

    1987-03-06

    Phosphate esters and anhydrides dominate the living world but are seldom used as intermediates by organic chemists. Phosphoric acid is specially adapted for its role in nucleic acids because it can link two nucleotides and still ionize; the resulting negative charge serves both to stabilize the diesters against hydrolysis and to retain the molecules within a lipid membrane. A similar explanation for stability and retention also holds for phosphates that are intermediary metabolites and for phosphates that serve as energy sources. Phosphates with multiple negative charges can react by way of the monomeric metaphosphate ion PO3- as an intermediate. No other residue appears to fulfill the multiple roles of phosphate in biochemistry. Stable, negatively charged phosphates react under catalysis by enzymes; organic chemists, who can only rarely use enzymatic catalysis for their reactions, need more highly reactive intermediates than phosphates.

  2. Research and engineering assessment of biological solubilization of phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, R.D.; McIlwain, M.E.; Losinski, S.J.; Taylor, D.D.

    1993-03-01

    This research and engineering assessment examined a microbial phosphate solubilization process as a method of recovering phosphate from phosphorus containing ore compared to the existing wet acid and electric arc methods. A total of 860 microbial isolates, collected from a range of natural environments were tested for their ability to solubilize phosphate from rock phosphate. A bacterium (Pseudomonas cepacia) was selected for extensive characterization and evaluation of the mechanism of phosphate solubilization and of process engineering parameters necessary to recover phosphate from rock phosphate. These studies found that concentration of hydrogen ion and production of organic acids arising from oxidation of the carbon source facilitated microbial solubilization of both pure chemical insoluble phosphate compounds and phosphate rock. Genetic studies found that phosphate solubilization was linked to an enzyme system (glucose dehydrogenase). Process-related studies found that a critical solids density of 1% by weight (ore to liquid) was necessary for optimal solubilization. An engineering analysis evaluated the cost and energy requirements for a 2 million ton per year sized plant, whose size was selected to be comparable to existing wet acid plants.

  3. Discussion about magnesium phosphating

    Directory of Open Access Journals (Sweden)

    P. Pokorny

    2016-07-01

    Full Text Available The paper describes results from recently published research focused on production of non-conventional magnesium phosphate Mg3(PO42・4H2O – bobierrite, or MgHPO4・3H2O – newberyite coating for both magnesium alloys and/or mild steel. This new kind of coating is categorized in the context of current state of phosphating technology and its potential advantages and crystal structure is discussed. At the same time, the suitable comparison techniques for magnesium phosphate coating and conventional zinc phosphate coating are discussed.

  4. Molecular mechanisms of crystallization impacting calcium phosphate cements

    OpenAIRE

    2010-01-01

    The biomineral calcium hydrogen phosphate dihydrate (CaHPO4·2H2O), known as brushite, is a malleable material that both grows and dissolves faster than most other calcium minerals, including other calcium phosphate phases, calcium carbonates and calcium oxalates. Within the body, this ready formation and dissolution can play a role in certain diseases, such as kidney stone and plaque formation. However, these same properties, along with brushite’s excellent biocompatibility, can be used to gr...

  5. Solvothermal synthesis of strontium phosphate chloride nanowire

    Science.gov (United States)

    Lam, W. M.; Wong, C. T.; Li, Z. Y.; Luk, K. D. K.; Chan, W. K.; Yang, C.; Chiu, K. Y.; Xu, B.; Lu, W. W.

    2007-08-01

    Strontium phosphate chloride nanowire was synthesized via a solvothermal treatment of strontium tri-polyphosphate and Collin salt in 1,4-dioxane at 150 °C. The effects of 1,4-dioxane concentration on particle morphology, crystallinity and phase purity were investigated in this study. The specimen morphology was analyzed by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). When the concentration of 1,4-dioxane was below 10%, micron-sized whisker was the dominant form. At 20-25% concentration of 1,4-dioxane, strontium phosphate chloride single-crystalline nanowire was 31±12 nm in diameter and 1.43±0.6 μm in length with an aspect ratio of 52.28±29.41. X-ray diffraction (XRD) pattern of this nanowire matched with that of strontium phosphate chloride (JCPDS #083-0973). When 1,4-dioxane concentration exceeded 25%, nanorod aggregate was the dominant form instead of nanowire. At 20-25% 1,4-dioxane concentration suitable strontium concentration combine with high chemical potential environment favors the formation of nanowires. By adding 1,4-dioxane impure phase such as β-strontium hydrogen phosphate, nanorod formation was suppressed. This method provides an efficient way to synthesize high aspect ratio strontium phosphate chloride nanowire. It has potential bioactive nanocomposite, high mechanical performance bioactive bone cement filler and fluorescent material applications.

  6. Hydrogen sensor

    Science.gov (United States)

    Duan, Yixiang; Jia, Quanxi; Cao, Wenqing

    2010-11-23

    A hydrogen sensor for detecting/quantitating hydrogen and hydrogen isotopes includes a sampling line and a microplasma generator that excites hydrogen from a gas sample and produces light emission from excited hydrogen. A power supply provides power to the microplasma generator, and a spectrometer generates an emission spectrum from the light emission. A programmable computer is adapted for determining whether or not the gas sample includes hydrogen, and for quantitating the amount of hydrogen and/or hydrogen isotopes are present in the gas sample.

  7. Accessing alkali-free NASICON-type compounds through mixed oxoanion sol-gel chemistry: Hydrogen titanium phosphate sulfate, H1-xTi2(PO4)3-x(SO4)x (x=0.5-1)

    Science.gov (United States)

    Mieritz, Daniel; Davidowski, Stephen K.; Seo, Dong-Kyun

    2016-10-01

    We report a direct sol-gel synthesis and characterization of new proton-containing, rhombohedral NASICION-type titanium compounds with mixed phosphate and sulfate oxoanions. The synthetic conditions were established by utilizing peroxide ion as a decomposable and stabilizing ligand for titanyl ions in the presence of phosphates in a strong acidic medium. Thermogravimetric analysis (TGA), powder X-ray diffraction (PXRD), induction-coupled plasma optical emission spectroscopic (ICP-OES) elemental analysis, and Raman and 1H magic angle spinning nuclear magnetic resonance (MAS-NMR) spectroscopic studies have determined the presence of sulfate and proton ions in the structure, for which the compositional range has been found to be H1-xTi2(PO4)3-x(SO4)x (x=0.5-1). The particulate products exhibit a nanocrystalline nature observed through characterization with scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The N2 sorption isotherm measurements and subsequent Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH) analyses confirmed the presence of the textural meso- and macropores in the materials. Future studies would determine the potential of the new compounds in various applications as battery materials, proton conductors and solid acid catalysts.

  8. Radioactivity of phosphate mineral products

    OpenAIRE

    Mitrović Branislava; Vitorović Gordana; Stojanović Mirjana; Vitorović Duško

    2011-01-01

    The phosphate industry is one of the biggest polluters of the environment with uranium. Different products are derived after processing phosphoric ore, such as mineral and phosphate fertilizers and phosphate mineral supplements (dicalcium-and monocalcium phosphate) for animal feeding. Phosphate mineral additives used in animal food may contain a high activity of uranium. Research in this study should provide an answer to the extent in which phosphate minera...

  9. Hydrogen in Martian Meteorites

    Science.gov (United States)

    Peslier, A. H.; Hervig, R.; Irving, T.

    2017-01-01

    Most volatile studies of Mars have targeted its surface via spacecraft and rover data, and have evidenced surficial water in polar caps and the atmosphere, in the presence of river channels, and in the detection of water bearing minerals. The other focus of Martian volatile studies has been on Martian meteorites which are all from its crust. Most of these studies are on hydrous phases like apatite, a late-stage phase, i.e. crystallizing near the end of the differentiation sequence of Martian basalts and cumulates. Moreover, calculating the water content of the magma a phosphate crystallized from is not always possible, and yet is an essential step to estimate how much water was present in a parent magma and its source. Water, however, is primarily dissolved in the interiors of differentiated planets as hydrogen in lattice defects of nominally anhydrous minerals (olivine, pyroxene, feldspar) of the crust and mantle. This hydrogen has tremendous influence, even in trace quantities, on a planet's formation, geodynamics, cooling history and the origin of its volcanism and atmosphere as well as its potential for life. Studies of hydrogen in nominally anhydrous phases of Martian meteorites are rare. Measuring water contents and hydrogen isotopes in well-characterized nominally anhydrous minerals of Martian meteorites is the goal of our study. Our work aims at deciphering what influences the distribution and origin of hydrogen in Martian minerals, such as source, differentiation, degassing and shock.

  10. Tetramethylammonium dihydrogen phosphate hemihydrate

    Directory of Open Access Journals (Sweden)

    Kyoko Fujita

    2009-04-01

    Full Text Available In the crystal structure of the title compound, C4H12N+·H2PO4−·0.5H2O, the anions form an infinite hydrogen-bonded chain along the [1overline{1}0] direction. The anion chains are connected by water molecules, which lie on crystallographic twofold rotation axes, through O—H...O hydrogen bonds. These hydrogen bonds are almost perpendicular to the other hydrogen bonds which create an assembled structure of anions. In addition, C—H...O hydrogen bonds between anions and cations are observed.

  11. Sources of conductance changes during bacterial reduction of trimethylamine oxide to trimethylammonium in phosphate buffer.

    Science.gov (United States)

    Owens, J D; Miskin, D R; Wacher-Viveros, M C; Benge, L C

    1985-06-01

    The sources of conductance changes during reduction of trimethylamine oxide to trimethylamine by Escherichia coli with formate as electron donor and in the presence of phosphate buffer were investigated. Theoretical considerations and experimental results suggest that the major source of conductance change is the conversion of dihydrogen phosphate to hydrogen phosphate. This transformation contributes almost twice as much to the total conductance change as does the conversion of uncharged trimethylamine oxide to charged trimethylammonium.

  12. Metal-phosphate binders

    Science.gov (United States)

    Howe, Beth Ann [Lewistown, IL; Chaps-Cabrera, Jesus Guadalupe [Coahuila, MX

    2009-05-12

    A metal-phosphate binder is provided. The binder may include an aqueous phosphoric acid solution, a metal-cation donor including a metal other than aluminum, an aluminum-cation donor, and a non-carbohydrate electron donor.

  13. Phosphate control in dialysis.

    Science.gov (United States)

    Cupisti, Adamasco; Gallieni, Maurizio; Rizzo, Maria Antonietta; Caria, Stefania; Meola, Mario; Bolasco, Piergiorgio

    2013-10-04

    Prevention and correction of hyperphosphatemia is a major goal of chronic kidney disease-mineral and bone disorder (CKD-MBD) management, achievable through avoidance of a positive phosphate balance. To this aim, optimal dialysis removal, careful use of phosphate binders, and dietary phosphate control are needed to optimize the control of phosphate balance in well-nourished patients on a standard three-times-a-week hemodialysis schedule. Using a mixed diffusive-convective hemodialysis tecniques, and increasing the number and/or the duration of dialysis tecniques are all measures able to enhance phosphorus (P) mass removal through dialysis. However, dialytic removal does not equal the high P intake linked to the high dietary protein requirement of dialysis patients; hence, the use of intestinal P binders is mandatory to reduce P net intestinal absorption. Unfortunately, even a large dose of P binders is able to bind approximately 200-300 mg of P on a daily basis, so it is evident that their efficacy is limited in the case of an uncontrolled dietary P load. Hence, limitation of dietary P intake is needed to reach the goal of neutral phosphate balance in dialysis, coupled to an adequate protein intake. To this aim, patients should be informed and educated to avoid foods that are naturally rich in phosphate and also processed food with P-containing preservatives. In addition, patients should preferentially choose food with a low P-to-protein ratio. For example, patients could choose egg white or protein from a vegetable source. Finally, boiling should be the preferred cooking procedure, because it induces food demineralization, including phosphate loss. The integrated approach outlined in this article should be actively adapted as a therapeutic alliance by clinicians, dieticians, and patients for an effective control of phosphate balance in dialysis patients.

  14. NMR studies on mechanism of isomerisation of fructose 6-phosphate to glucose 6-phosphate catalysed by phosphoglucose isomerase from Thermococcus kodakarensis.

    Science.gov (United States)

    Abbas, Shahzada Nadeem; Mok, Kenneth Hun; Rashid, Naeem; Xie, Yongjing; Ruether, Manuel; O'Brien, John; Akhtar, Muhammad

    2016-06-01

    The fate of hydrogen atoms at C-2 of glucose 6-phosphate (G6P) and C-1 of fructose 6-phosphate (F6P) was studied in the reaction catalysed by phosphoglucose isomerase from Thermococcus kodakarensis (TkPGI) through 1D and 2D NMR methods. When the reaction was performed in (2)H2O the hydrogen atoms in the aforementioned positions were exchanged with deuterons indicating that the isomerization occurred by a cis-enediol intermediate involving C-1 pro-R hydrogen of F6P. These features are similar to those described for phosphoglucose isomerases from rabbit muscle and Pyrococcus furiosus.

  15. Apatite Formation from Amorphous Calcium Phosphate and Mixed Amorphous Calcium Phosphate/Amorphous Calcium Carbonate.

    Science.gov (United States)

    Ibsen, Casper J S; Chernyshov, Dmitry; Birkedal, Henrik

    2016-08-22

    Crystallization from amorphous phases is an emerging pathway for making advanced materials. Biology has made use of amorphous precursor phases for eons and used them to produce structures with remarkable properties. Herein, we show how the design of the amorphous phase greatly influences the nanocrystals formed therefrom. We investigate the transformation of mixed amorphous calcium phosphate/amorphous calcium carbonate phases into bone-like nanocrystalline apatite using in situ synchrotron X-ray diffraction and IR spectroscopy. The speciation of phosphate was controlled by pH to favor HPO4 (2-) . In a carbonate free system, the reaction produces anisotropic apatite crystallites with large aspect ratios. The first formed crystallites are highly calcium deficient and hydrogen phosphate rich, consistent with thin octacalcium phosphate (OCP)-like needles. During growth, the crystallites become increasingly stoichiometric, which indicates that the crystallites grow through addition of near-stoichiometric apatite to the OCP-like initial crystals through a process that involves either crystallite fusion/aggregation or Ostwald ripening. The mixed amorphous phases were found to be more stable against phase transformations, hence, the crystallization was inhibited. The resulting crystallites were smaller and less anisotropic. This is rationalized by the idea that a local phosphate-depletion zone formed around the growing crystal until it was surrounded by amorphous calcium carbonate, which stopped the crystallization.

  16. Determination of Vitamin D2 Content in Vitamin D2 and Calcium Hydrogen Phosphate Tablets by RP-HPLC%反相高效液相色谱法测定维D2磷酸氢钙片中维生素D2含量

    Institute of Scientific and Technical Information of China (English)

    冯国

    2013-01-01

    Objective To establish a RP-HPLC method for the content determination of vitamin D2 in Vitamin D2 and Calcium Hydrogen Phosphate Tablets.Methods The chromatographic column of AlltimaTM C18 was adopted with the mobile phase of acetonitrilemethanol(1∶9).The detection wavelength was set at 265 nm,the flow velocity was 1.0 mL/min and column temperature was 30 ℃.Results The sample size of vitamin D2 within the range of 0.005-0.065 μg(r=1.000 0)showed the good linearity with the peak area.The mean recovery rate was 99.38%,RSD =0.68% (n =9).Conclusion This method has the advantages of rapidness,simpleness,accuracy and low test cost,and can be used for the quality control of vitamin D2 in Vitamin D2 and Calcium Hydrogen Phosphate Tablets.%目的 建立测定维D2磷酸氢钙片中维生素D2含量的反相高效液相色谱法.方法 采用Alhima C18色谱柱(250 mm×4.6mm,5 μm),流动相为乙腈-甲醇(1∶9),检测波长为265 nm,流速为1.0 mL/min,柱温30℃.结果 维生素D2进样量在0.005~0.065 μg范围内与峰面积具有良好的线性关系,r=1.0000,平均回收率为99.38%,RSD=0.68%(n=9).结论 该法具有快速、简便、准确、检验成本低的优点,可用于维D2磷酸氢钙片中维生素D2的质量控制.

  17. Improvement of the determination method for the contents of vitamin D2 in Eight Vitamins and Calcium Hydrogen Phosphate,Zinc Sulphate Tablets%八维钙锌片中维生素D2含量测定方法的改进

    Institute of Scientific and Technical Information of China (English)

    柳小秦; 尹琳; 吴少平

    2011-01-01

    目的 改进八维钙锌片中维生素D2含量测定的方法.方法 采用HPLC法,以Thermo 硅胶(250 mm×4.6 mm,5 μm) 为色谱柱;流动相:正己烷-异丙醇(110∶1);流速:1.0 mL·min-1;检测波长:254 nm;柱温:35 ℃.结果 维生素D2的线性范围为质量浓度0.5~10 mg·L-1,相关系数为0.995 8,回收率为100.8%(n=9).结论 该方法简便准确,重复性好,可作为控制八维钙锌片中维生素D2的含量测定方法.%Objective To improve the contents determination method of vitamin D2 in Eight Vitamins and Calcium Hydrogen Phosphate, Zinc Sulphate Tablets. Methods The contents of vitamin D2 were measured by HPLC with a Thermo Silica chromatographic column (250 mm×4.6 mm,5 μm). n -Hexane-isopropanol(ll0 ∶ 1) was used as the mobile phase at flow rate 1. 0 mL · min-1. The detection wavelength was 254 nm and the column temperature was 35 ℃ . Results The calibration curves showed good linearity in the range of 0. 5-10 mg · L-1 and the correlation coefficient was 0. 995 8. The average recoveries were 100. 8% ( n = 9) .Conclusion The established method is accurate and reproducible,and can be used for the quality control of vitamin D2 in Eight Vitamins and Calcium Hydrogen Phosphate, Zinc Sulphate Tablets.

  18. Phosphate mineral formation on the supported dipalmitoylphosphatidylcholine (DPPC) layers.

    Science.gov (United States)

    Szcześ, Aleksandra

    2014-07-01

    Dipalmitoylphosphatidylcholine (DPPC) mono- and bilayers supported on mica surface were soaked for two weeks in a simulated body fluid (SBF) with ion concentrations nearly equal to those of human blood plasma. Two solutions were investigated: with and without Tris. The experiment was conducted at 20°C and at a physiological temperature equal to 37°C. Raman spectroscopy was used for the characterization of the precipitated phosphate minerals. These studies may provide information about the physiological mineralization of cell membranes that are mainly composed of phospholipids. Findings from these experiments suggest that the DPPC bilayers enhance the formation of less soluble phosphate forms especially at a temperature of 37°C. In the solution without Tris temperature increase gives more mineral deposits. It is probably the hydrogen interactions between phosphate groups of the phospholipid and hydroxyl groups from Tris that lower exposure of the phosphate group to interact with calcium ions.

  19. Reagentless phosphate ion sensor system for environmental monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, M.; Kurata, H.; Inoue, Y.; Shin, H. [Kyushu Institute of Technology, Fukuoka (Japan). Faculty of computer Science and Systems; Kubo, I. [Soka University, Tokyo (Japan). Faculty of Engineering; Nakamura, H.; Ikebukuro, K.; Karube, I. [The University of Tokyo, Tokyo (Japan). Research Center for Advanced Science and Technology

    1998-06-05

    Phosphate ion sensor system using an electrochemical detector was developed by the use of recombinant pyruvate oxidase (PyOD) from Lactobacillus plantarum, which needs no addition of thiamine pyrophosphate and flavin adenine dinucleotide for reaction. This system could detect 2 nM hydrogen peroxide. Response time for phosphate ion was 80 s and total measurement time for one sample was 3 min. Citrate buffer solution (pH 6.3) was most suitable for the measurement and optimum flow rate was 0.6 ml/min. Under these optimum conditions minimum detection limit of phosphate ion was 15 nM, which was enough for the determination of phosphate ion in dam-lake. 6 refs., 5 figs., 1 tab.

  20. Iron Phosphate Coating:A Novel Approach to Controlling Pyrite Oxidation

    Institute of Scientific and Technical Information of China (English)

    HUANGXIAO; V.P.EVANGELOU

    1997-01-01

    A novel coating technique was develped for controlling pyrite oxidation .The technique involved leaching pyrite particles with a solution containing low concentrations of phosphate and hydrogen peroxide.During the leaching rpocess,the iron released from pyrite by hydrogen proxide was precipitated by phosphate as a ferric phosphate coating .This coating was shown to be able to effectively prevent pyirte from oxidation and it could be established at the expense of only surface portions of pyrite.The emergence of this technique could provide a unique potential route for abating acid mine draingage and reclaiming sulfide-containing degraded mining land.

  1. Phosphate control in dialysis

    Directory of Open Access Journals (Sweden)

    Cupisti A

    2013-10-01

    Full Text Available Adamasco Cupisti,1 Maurizio Gallieni,2 Maria Antonietta Rizzo,2 Stefania Caria,3 Mario Meola,4 Piergiorgio Bolasco31Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy; 2Nephrology and Dialysis Unit, San Carlo Borromeo Hospital, Milan, Italy; 3Territorial Department of Nephrology and Dialysis, ASL Cagliari, Italy; 4Sant'Anna School of Advanced Studies, University of Pisa, Pisa, ItalyAbstract: Prevention and correction of hyperphosphatemia is a major goal of chronic kidney disease–mineral and bone disorder (CKD–MBD management, achievable through avoidance of a positive phosphate balance. To this aim, optimal dialysis removal, careful use of phosphate binders, and dietary phosphate control are needed to optimize the control of phosphate balance in well-nourished patients on a standard three-times-a-week hemodialysis schedule. Using a mixed diffusive–convective hemodialysis tecniques, and increasing the number and/or the duration of dialysis tecniques are all measures able to enhance phosphorus (P mass removal through dialysis. However, dialytic removal does not equal the high P intake linked to the high dietary protein requirement of dialysis patients; hence, the use of intestinal P binders is mandatory to reduce P net intestinal absorption. Unfortunately, even a large dose of P binders is able to bind approximately 200–300 mg of P on a daily basis, so it is evident that their efficacy is limited in the case of an uncontrolled dietary P load. Hence, limitation of dietary P intake is needed to reach the goal of neutral phosphate balance in dialysis, coupled to an adequate protein intake. To this aim, patients should be informed and educated to avoid foods that are naturally rich in phosphate and also processed food with P-containing preservatives. In addition, patients should preferentially choose food with a low P-to-protein ratio. For example, patients could choose egg white or protein from a vegetable source

  2. Hydrogen Production

    Energy Technology Data Exchange (ETDEWEB)

    None

    2014-09-01

    This 2-page fact sheet provides a brief introduction to hydrogen production technologies. Intended for a non-technical audience, it explains how different resources and processes can be used to produce hydrogen. It includes an overview of research goals as well as “quick facts” about hydrogen energy resources and production technologies.

  3. Hydrogen storage

    NARCIS (Netherlands)

    Peters, C.J.; Sloan, E.D.

    2005-01-01

    The invention relates to the storage of hydrogen. The invention relates especially to storing hydrogen in a clathrate hydrate. The clathrate hydrate according to the present invention originates from a composition, which comprises water and hydrogen, as well as a promotor compound. The promotor comp

  4. Phosphate Mines, Jordan

    Science.gov (United States)

    2008-01-01

    Jordan's leading industry and export commodities are phosphate and potash, ranked in the top three in the world. These are used to make fertilizer. The Jordan Phosphate Mines Company is the sole producer, having started operations in 1935. In addition to mining activities, the company produces phosphoric acid (for fertilizers, detergents, pharmaceuticals), diammonium phosphate (for fertilizer), sulphuric acid (many uses), and aluminum fluoride (a catalyst to make aluminum and magnesium). The image covers an area of 27.5 x 49.4 km, was acquired on September 17, 2005, and is located near 30.8 degrees north latitude, 36.1 degrees east longitude. The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  5. Synthesis and controllable wettability of micro- and nanostructured titanium phosphate thin films formed on titanium plates.

    Science.gov (United States)

    Yada, Mitsunori; Inoue, Yuko; Sakamoto, Ayako; Torikai, Toshio; Watari, Takanori

    2014-05-28

    The hydrothermal treatment of a titanium plate in a mixed aqueous solution of hydrogen peroxide and aqueous phosphoric acid under different conditions results in the formation of various titanium phosphate thin films. The films have various crystal structures such as Ti2O3(H2PO4)2·2H2O, α-titanium phosphate (Ti(HPO4)2·H2O), π-titanium phosphate (Ti2O(PO4)2·H2O), or low-crystallinity titanium phosphate and different morphologies that have not been previously reported such as nanobelts, microflowers, nanosheets, nanorods, or nanoplates. The present study also suggests the mechanisms behind the formation of these thin films. The crystal structure and morphology of the titanium phosphate thin films depend strongly on the concentration of the aqueous hydrogen peroxide solution, the amount of phosphoric acid, and the reaction temperature. In particular, hydrogen peroxide plays an important role in the formation of the titanium phosphate thin films. Moreover, controllable wettability of the titanium phosphate thin films, including superhydrophilicity and superhydrophobicity, is reported. Superhydrophobic surfaces with controllable adhesion to water droplets are obtained on π-titanium phosphate nanorod thin films modified with alkylamine molecules. The adhesion force between a water droplet and the thin film depends on the alkyl chain length of the alkylamine and the duration of ultraviolet irradiation utilized for photocatalytic degradation.

  6. HPLC法同时测定三维葡磷钙咀嚼片中维生素B1、维生素B2的含量%Content Determination of Vitamin B1 and Vitamin B2 in Trivitamin and Calcium Gluconate,Calcium Hydro-gen Phosphate Chewable Tablets by HPLC

    Institute of Scientific and Technical Information of China (English)

    李丹凤

    2015-01-01

    OBJECTIVE:To establish a method for the content determination of vitamin B1 and vitamin B2 in Trivitamin and calci-um gluconate,calcium hydrogen phosphate chewable tablets. METHODS:HPLC was conducted. The column was Inertsil C18 with the mobile phase of 1%triethylamine contained 0.02 mol/L of sodium heptane solution(pH was adjusted to 5.5 by phosphate)-methanol (74∶26,V/V)at the flow rate of 1.0 ml/min,the detection wavelength was 260 nm,temperature was 30℃and the volume was 20μl. RESULTS:There was a good linear relationship between the quality concentration of vitamin B1 and peak area in the range of 0.22-1.10μg/ml(r=0.999 8)and vitamin B2 was in the range of 0.22-1.09μg/ml(r=0.999 7). The RSDs of precision,reproducibility and stabil-ity tests were all less than 1%;the average recovery was respectively 99.66%(RSD=0.96%,n=9)and 100.31%(RSD=0.92%,n=9). CONCLUSIONS:The method is simple,accurate,sensitive and reliable and suitable for the content determination of vitamin B1 and vitamin B2 in Trivitamin and calcium gluconate,calcium hydrogen phosphate chewable tablets.%目的:建立同时测定三维葡磷钙咀嚼片中维生素B1、维生素B2含量的方法。方法:采用高效液相色谱法。色谱柱为Inertsil C18,流动相为含1%三乙胺的0.02 mol/L庚烷磺酸钠溶液(磷酸调pH至5.5)-甲醇(74∶26,V/V),检测波长为260 nm,流速为1.0 ml/min,柱温为30℃,进样量为20μl。结果:维生素B1、维生素B2质量浓度分别在0.22~1.10、0.22~1.09μg/ml范围内与各自峰面积呈良好的线性关系(r=0.9998、0.9997);精密度、稳定性、重复性试验的RSD<1%;平均加样回收率分别为99.66%、100.31%,RSD分别为0.96%、0.92%(n=9)。结论:本方法简便、准确度高,可用于三维葡磷钙咀嚼片中维生素B1、维生素B2的含量测定。

  7. Research on Uncrystallized Phosphating Film

    Institute of Scientific and Technical Information of China (English)

    TANG En-jun; XING Ze-kuan

    2004-01-01

    This article excogitated a kind of uncrystallized phosphating film bears wearing capacity goodly by adding Ca2 + in normal phosphating solution. This technology is very useful to protect steel parts working in oil from abrasion.

  8. Glucose-6-phosphate dehydrogenase deficiency

    Science.gov (United States)

    ... medlineplus.gov/ency/article/000528.htm Glucose-6-phosphate dehydrogenase deficiency To use the sharing features on this page, please enable JavaScript. Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a condition in which ...

  9. Phosphate enhances Fgf23 expression through reactive oxygen species in UMR-106 cells.

    Science.gov (United States)

    Hori, Michiko; Kinoshita, Yuka; Taguchi, Manabu; Fukumoto, Seiji

    2016-03-01

    Fibroblast growth factor 23 (FGF23) has been shown to work as a phosphotropic hormone. Although FGF23 reduces the serum phosphate level, it has not been established that phosphate directly regulates FGF23 production. In this study, we investigated whether phosphate can enhance Fgf23 expression using the rat osteoblastic cell line UMR-106, which has been shown to express Fgf23 in response to 1,25-dihydroxyvitamin D [1,25(OH)2D]. Phosphate increased Fgf23 expression in a dose- and time-dependent manner in the presence of 1,25(OH)2D. Phosphate also increased Fgf23 promoter activity, but showed no effect on the half-life of Fgf23 messenger RNA. Phosphonoformic acid and PD98059, an inhibitor of MEK, inhibited the effects of phosphate on Fgf23 expression and promoter activity. In addition, phosphate enhanced production of reactive oxygen species (ROS) in UMR-106 cells, and hydrogen peroxide enhanced FGF23 production in a dose- and time-dependent manner. Hydrogen peroxide also enhanced Elk1 reporter activity, a target of the MEK-extracellular-signal-regulated kinase (ERK) pathway. Furthermore, the effect of phosphate on ROS production and Fgf23 expression was inhibited by apocynin, an inhibitor of NADPH oxidase. These results indicate that phosphate directly enhances Fgf23 transcription without affecting the stability of Fgf23 messenger RNA by stimulating NADPH-induced ROS production and the MEK-ERK pathway in UMR-106 cells.

  10. Hydrogen Embrittlement

    Science.gov (United States)

    Woods, Stephen; Lee, Jonathan A.

    2016-01-01

    Hydrogen embrittlement (HE) is a process resulting in a decrease in the fracture toughness or ductility of a metal due to the presence of atomic hydrogen. In addition to pure hydrogen gas as a direct source for the absorption of atomic hydrogen, the damaging effect can manifest itself from other hydrogen-containing gas species such as hydrogen sulfide (H2S), hydrogen chloride (HCl), and hydrogen bromide (HBr) environments. It has been known that H2S environment may result in a much more severe condition of embrittlement than pure hydrogen gas (H2) for certain types of alloys at similar conditions of stress and gas pressure. The reduction of fracture loads can occur at levels well below the yield strength of the material. Hydrogen embrittlement is usually manifest in terms of singular sharp cracks, in contrast to the extensive branching observed for stress corrosion cracking. The initial crack openings and the local deformation associated with crack propagation may be so small that they are difficult to detect except in special nondestructive examinations. Cracks due to HE can grow rapidly with little macroscopic evidence of mechanical deformation in materials that are normally quite ductile. This Technical Memorandum presents a comprehensive review of experimental data for the effects of gaseous Hydrogen Environment Embrittlement (HEE) for several types of metallic materials. Common material screening methods are used to rate the hydrogen degradation of mechanical properties that occur while the material is under an applied stress and exposed to gaseous hydrogen as compared to air or helium, under slow strain rates (SSR) testing. Due to the simplicity and accelerated nature of these tests, the results expressed in terms of HEE index are not intended to necessarily represent true hydrogen service environment for long-term exposure, but rather to provide a practical approach for material screening, which is a useful concept to qualitatively evaluate the severity of

  11. Practical application of phosphate treatment

    Energy Technology Data Exchange (ETDEWEB)

    Caravaggio, Mike [Integrated Chemistry Solutions Pte. Ltd., Singapore (Singapore)

    2011-05-15

    Phosphate treatment has been applied to subcritical fossil power boilers for well over half a century, as well as being used frequently in heat recovery steam generators. The use of this treatment has evolved over the decades, with the operating sodium to phosphate ratio being the defining factor for the evolution of the treatment. The evolving prescribed sodium to phosphate ratios have been based on the scientific research results and operating experience available at the time, and in the latest EPRI Guidelines issued in 2004 are set at a minimum sodium to phosphate ratio of 3:1, with provision to add up to 1 mg . L{sup -1} of additional free caustic. The ratio limitation has always been set in an effort to minimize the potential for corrosion caused by the potential misapplication of the treatment. Typically, the operating ranges for phosphate treatments are depicted on an x-y plot with the x-axis the phosphate concentration and the y-axis the corrected pH value based on the maximum sodium to phosphate ratio allowed for by the treatment. These operating range plots define the theoretical operating range of a phosphate treatment. This paper briefly discusses the origin of the current phosphate control limits in the EPRI Guidelines, discusses phosphate chemistry, outlines the limitations involved when applying a phosphate treatment and provides additional practical guidance for overcoming these limitations and minimizing the potential for corrosion induced by the incorrect application of a phosphate treatment. (orig.)

  12. Expanding sapphyrin: towards selective phosphate binding.

    Science.gov (United States)

    Katayev, Evgeny A; Boev, Nikolay V; Myshkovskaya, Ekaterina; Khrustalev, Victor N; Ustynyuk, Yu A

    2008-01-01

    The anion-templated syntheses and binding properties of novel macrocyclic oligopyrrole receptors in which pyrrole rings are linked through amide or imine bonds are described. The efficient synthesis was accomplished by anion-templated [1+1] Schiff-base condensation and acylation macrocyclization reactions. Free receptors and their host-guest complexes with hydrochloric acid, acetic acid, tetrabutylammonium chloride, and hydrogen sulfate were analyzed by single-crystal X-ray diffraction analysis. Stability constants with different tetrabutylammonium salts of inorganic acids were determined by standard 1H NMR and UV/Vis titration techniques in [D6]DMSO/0.5% water solution. According to the titration data, receptors containing three pyrrole rings (10 and 12) exhibit high affinity (log Ka=5-7) for bifluoride, acetate, and dihydrogen phosphate, and interact weakly with chloride and hydrogen sulfate. The amido-bipyrrole receptors 11 and 13 with four pyrrole rings exhibit 10(4)- and 10(2)-fold selectivity for dihydrogen phosphate, respectively, as inferred from competitive titrations in the presence of tetrabutylammonium acetate.

  13. Hydrogen Spectrum

    Science.gov (United States)

    Murdin, P.

    2000-11-01

    The series of absorption or emission lines that are characteristic of the hydrogen atom. According to the Bohr theory of the hydrogen atom, devised by Danish physicist Neils Bohr (1885-1962) in 1913, the hydrogen atom can be envisaged as consisting of a central nucleus (a proton) around which a single electron revolves. The electron is located in one of a number of possible permitted orbits, each...

  14. Calcium Phosphate Biomaterials: An Update

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Current calcium phosphate (CaP) biomaterials for bone repair, substitution, augmentation and regeneration include hydroxyapatite ( HA ) from synthetic or biologic origin, beta-tricalcium phosphate ( β-TCP ) , biphasic calcium phosphate (BCP), and are available as granules, porous blocks, components of composites (CaP/polymer) cements, and as coatings on orthopedic and dental implants. Experimental calcium phosphate biomaterials include CO3- and F-substituted apatites, Mg-and Zn-substituted β-TCP, calcium phosphate glasses. This paper is a brief review of the different types of CaP biomaterials and their properties such as bioactivity, osteoconductivity, osteoinductivity.

  15. Biomediated continuous release phosphate fertilizer

    Science.gov (United States)

    Goldstein, Alan H.; Rogers, Robert D.

    1999-01-01

    A composition is disclosed for providing phosphate fertilizer to the root zone of plants. The composition comprises a microorganism capable of producing and secreting a solubilization agent, a carbon source for providing raw material for the microorganism to convert into the solubilization agent, and rock phosphate ore for providing a source of insoluble phosphate that is solubilized by the solubilization agent and released as soluble phosphate. The composition is provided in a physical form, such as a granule, that retains the microorganism, carbon source, and rock phosphate ore, but permits water and soluble phosphate to diffuse into the soil. A method of using the composition for providing phosphate fertilizer to plants is also disclosed.

  16. Hydrogen Bibliography

    Energy Technology Data Exchange (ETDEWEB)

    1991-12-01

    The Hydrogen Bibliography is a compilation of research reports that are the result of research funded over the last fifteen years. In addition, other documents have been added. All cited reports are contained in the National Renewable Energy Laboratory (NREL) Hydrogen Program Library.

  17. Hydrogen exchange

    DEFF Research Database (Denmark)

    Jensen, Pernille Foged; Rand, Kasper Dyrberg

    2016-01-01

    Hydrogen exchange (HX) monitored by mass spectrometry (MS) is a powerful analytical method for investigation of protein conformation and dynamics. HX-MS monitors isotopic exchange of hydrogen in protein backbone amides and thus serves as a sensitive method for probing protein conformation...... and dynamics along the entire protein backbone. This chapter describes the exchange of backbone amide hydrogen which is highly quenchable as it is strongly dependent on the pH and temperature. The HX rates of backbone amide hydrogen are sensitive and very useful probes of protein conformation......, as they are distributed along the polypeptide backbone and form the fundamental hydrogen-bonding networks of basic secondary structure. The effect of pressure on HX in unstructured polypeptides (poly-dl-lysine and oxidatively unfolded ribonuclease A) and native folded proteins (lysozyme and ribonuclease A) was evaluated...

  18. Hydrogen carriers

    Science.gov (United States)

    He, Teng; Pachfule, Pradip; Wu, Hui; Xu, Qiang; Chen, Ping

    2016-12-01

    Hydrogen has the potential to be a major energy vector in a renewable and sustainable future energy mix. The efficient production, storage and delivery of hydrogen are key technical issues that require improvement before its potential can be realized. In this Review, we focus on recent advances in materials development for on-board hydrogen storage. We highlight the strategic design and optimization of hydrides of light-weight elements (for example, boron, nitrogen and carbon) and physisorbents (for example, metal-organic and covalent organic frameworks). Furthermore, hydrogen carriers (for example, NH3, CH3OH-H2O and cycloalkanes) for large-scale distribution and for on-site hydrogen generation are discussed with an emphasis on dehydrogenation catalysts.

  19. ION EXCHANGE SUBSTANCES BY SAPONIFICATION OF ALLYL PHOSPHATE POLYMERS

    Science.gov (United States)

    Kennedy, J.

    1959-04-14

    An ion exchange resin having a relatively high adsorption capacity tor uranyl ion as compared with many common cations is reported. The resin comprises an alphyl-allyl hydrogen phosphate polymer, the alphyl group being either allyl or a lower alkyl group having up to 5 carbon atoins. The resin is prepared by polymerizing compounds such as alkyl-diallyl phosphate and triallyl phosphate in the presence of a free radical generating substance and then partially hydrolyzing the resulting polymer to cause partial replacement of organic radicals by cations. A preferred free radical gencrating agent is dibenzoyl peroxide. The partial hydrolysis is brought about by refluxing the polymer with concentrated aqueous NaOH for three or four hours.

  20. Pyridoxal phosphate-dependent neonatal epileptic encephalopathy.

    Science.gov (United States)

    Bagci, S; Zschocke, J; Hoffmann, G F; Bast, T; Klepper, J; Müller, A; Heep, A; Bartmann, P; Franz, A R

    2008-03-01

    Pyridox(am)ine-5'-phosphate oxidase converts pyridoxine phosphate and pyridoxamine phosphate to pyridoxal phosphate, a cofactor in many metabolic reactions, including neurotransmitter synthesis. A family with a mutation in the pyridox(am)ine-5'-phosphate oxidase gene presenting with neonatal seizures unresponsive to pyridoxine and anticonvulsant treatment but responsive to pyridoxal phosphate is described. Pyridoxal phosphate should be considered in neonatal epileptic encephalopathy unresponsive to pyridoxine.

  1. Pyridoxal phosphate-dependent neonatal epileptic encephalopathy

    OpenAIRE

    2009-01-01

    Pyridox(am)ine-5′-phosphate oxidase converts pyridoxine phosphate and pyridoxamine phosphate to pyridoxal phosphate, a cofactor in many metabolic reactions, including neurotransmitter synthesis. A family with a mutation in the pyridox(am)ine-5′-phosphate oxidase gene presenting with neonatal seizures unresponsive to pyridoxine and anticonvulsant treatment but responsive to pyridoxal phosphate is described. Pyridoxal phosphate should be considered in neonatal epileptic encephalopathy unrespons...

  2. Structural Basis for Substrate Specificity in Phosphate Binding (beta/alpha)8-Barrels: D-Allulose 6-Phosphate 3-Epimerase from Escherichia coli K-12

    Energy Technology Data Exchange (ETDEWEB)

    Chan,K.; Fedorov, A.; Almo, S.; Gerlt, J.

    2008-01-01

    phosphate group hydrogen bonds not only with the conserved motif but also with an active site loop following the sixth {beta}-strand, providing a potential structural mechanism for coupling substrate binding with catalysis.

  3. Preparation of magnesium phosphate cement by recycling the product of thermal transformation of asbestos containing wastes

    OpenAIRE

    2014-01-01

    Asbestos containing wastes have been employed for the first time in the formulation of magnesium phosphate cements. Two samples were mixed with magnesium carbonate and calcined at 1100 and 1300 C. Under these conditions, complete destruction of asbestos minerals is known to occur. The product, containing MgO, after reaction with water-soluble potassium di-hydrogen phosphate, led to the formation of hydrated phases at room temperature. Crystalline and amorphous reaction products were detected,...

  4. Triphenyl phosphate allergy from spectacle frames

    DEFF Research Database (Denmark)

    Carlsen, L; Andersen, K E; Egsgaard, Helge

    1986-01-01

    A case of triphenyl phosphate allergy from spectacle frames is reported. Patch tests with analytical grade triphenyl phosphate, tri-m-cresyl phosphate, and tri-p-cresyl phosphate in the concentrations 5%, 0.5% and 0.05% pet. showed positive reactions to 0.05% triphenyl phosphate and 0.5% tri-m-cr...

  5. Folding of RNA tertiary structure: Linkages between backbone phosphates, ions, and water.

    Science.gov (United States)

    Draper, David E

    2013-12-01

    The functional forms of many RNAs have compact architectures. The placement of phosphates within such structures must be influenced not only by the strong electrostatic repulsion between phosphates, but also by networks of interactions between phosphates, water, and mobile ions. This review first explores what has been learned of the basic thermodynamic constraints on these arrangements from studies of hydration and ions in simple DNA molecules, and then gives an overview of what is known about ion and water interactions with RNA structures. A brief survey of RNA crystal structures identifies several interesting architectures in which closely spaced phosphates share hydration shells or phosphates are buried in environments that provide intramolecular hydrogen bonds or site-bound cations. Formation of these structures must require strong coupling between the uptake of ions and release of water.

  6. Metal Phosphates as Proton Conducting Materials for Intermediate Temperature Fuel Cell and Electrolyser Applications

    DEFF Research Database (Denmark)

    Anfimova, Tatiana

    The present thesis presents the results achieved during my ph.d. project on a subject of intermediate temperature proton conducting metal phosphates as electrolyte materials for fuel cells and electrolysers. Fuel cells and electrolysers are electrochemical devices with high energy conversion...... with a proton conductivity of above 10-2S cm-1. Chapter 1 of the thesis is an introduction to basics of fuel cell and electrolyser technologies as well as proton conducting materials. Extended discussion on the proton conducting materials, a particularly phosphates is made in Chapter 2. Three major types...... of phosphates were systematically reviewed including solid acids or alkali hydrogen phosphates, pyrophosphates, and rare earth metal phosphates. Demonstration of the fuel cell technology based on solid acid proton conductor CsH2PO4 has inspired the active research in the area. Based on the literature survey...

  7. Hydrogen program overview

    Energy Technology Data Exchange (ETDEWEB)

    Gronich, S. [Dept. of Energy, Washington, DC (United States). Office of Utility Technologies

    1997-12-31

    This paper consists of viewgraphs which summarize the following: Hydrogen program structure; Goals for hydrogen production research; Goals for hydrogen storage and utilization research; Technology validation; DOE technology validation activities supporting hydrogen pathways; Near-term opportunities for hydrogen; Market for hydrogen; and List of solicitation awards. It is concluded that a full transition toward a hydrogen economy can begin in the next decade.

  8. Light weight phosphate cements

    Science.gov (United States)

    Wagh, Arun S.; Natarajan, Ramkumar,; Kahn, David

    2010-03-09

    A sealant having a specific gravity in the range of from about 0.7 to about 1.6 for heavy oil and/or coal bed methane fields is disclosed. The sealant has a binder including an oxide or hydroxide of Al or of Fe and a phosphoric acid solution. The binder may have MgO or an oxide of Fe and/or an acid phosphate. The binder is present from about 20 to about 50% by weight of the sealant with a lightweight additive present in the range of from about 1 to about 10% by weight of said sealant, a filler, and water sufficient to provide chemically bound water present in the range of from about 9 to about 36% by weight of the sealant when set. A porous ceramic is also disclosed.

  9. THERMODINAMIC PARAMETERS ON THE SORPTION OF PHOSPHATE IONS BY MONTMORILLONITE

    Directory of Open Access Journals (Sweden)

    Ikhsan Jaslin

    2016-04-01

    Full Text Available The sorption of phosphate by montmorillonite at 10, 30, and 50 oC were investigated aiming to mainly determine thermodynamic parameters for the formation of surface complexes in the adsorption of phosphate ions by montmorillonite. Data were collected by adsorption edge experiments investigating the effect of pH, adsorption isotherms enabling the effect of sorbate concentration, and acid-base titration calculating protons released or taken up by adsorption process. Data analysis was carried out using surface complexation model to fit the data collected in this study using the parameters obtained from previous study, as well as to calculate the values of ΔH and ΔS. Previous study reported that phosphate ions formed two outer-sphere surface complexes with active sites of montmorillonite through hydrogen bonding. In the first complex,  [(XH0– H2L─]─, the phosphate was held to permanent-charge X─ sites on the tetrahedral siloxane faces, and the second complex, [[(SO─(SOH]– – [H2L]─] 2─ was formed through the interaction between the phosphate and variable charge surface hydroxyl groups at the edges of montmorillonite crystals and on the octahedral alumina faces. The values of ΔH for the first and second reactions are 39.756 and 3.765x10-7 kJ mol‒1 respectively. Since both reactions have positive enthalpy values, it can be concluded that the reactions are endothermic. Large energy for the first reaction is needed by X─  sites (permanent negatively charge sites of montmorillonite to be partially desolvated, on which K+ or other surface cations are replaced by H+ ions in the surface protonated process, and are then ready to interact phosphate ions in the solution. Small values of ΔH for the second reactions indicates that hydrogen bonds formed by phosphate and SOH sites in the second reaction are easily broken out, and the phosphate can easily desorbed from the surface. The values of ΔS for the first and second reactions are

  10. Crystallo-chemical analyses of calcium phosphates

    Energy Technology Data Exchange (ETDEWEB)

    Sakae, Toshiro; Hayakawa, Tohru; Maruyama, Fumiaki; Nemoto, Kimiya; Kozawa, Yukishige [Nihon Univ., Matsudo, Chiba (Japan). School of Dentistry

    1997-12-01

    Several analytical techniques, methodology and their practical data processing were briefly described to investigate the crystallographic properties of calcium phosphates which are encountered in the field of dental sciences. The applied analytical techniques were X-ray fluorescence spectrometry (XFS), energy dispersive spectrometry (EDS), Fourier transform infrared spectrometry (FT-IR) and X-ray diffraction (XRD). The used materials were tetracalcium phosphate, hydroxyapatite, fluorapatite, {alpha}-tricalcium phosphate, {beta}-tricalcium phosphate, octacalcium phosphate, monetite, brushite and monocalcium phosphate monohydrate. (author)

  11. Sperm motility under exposure of hydrogen dioxide

    Directory of Open Access Journals (Sweden)

    V. V. Evdokimov

    2015-01-01

    Full Text Available The paper contains research data on the effect of low concentrations of hydrogen dioxide on human sperm motility and specific enzyme activity of sperms of glyceraldehyde-3-phosphate dehydrogenase. It is shown that incubation of sperms with hydrogen dioxide in a low concentration leads to a change and motility in sperm and activity of sperm enzyme. Intensity of observed effect depended on the concentration of hydrogen dioxide: active mobility increased by 17–19 % and the total mobility – 11 %. Motility changes in sperms were accompanied by increased activity of glyceraldehyde-3-phosphate dehydrogenase by 24 %, in normozoospermia response was higher than in pathozoospermia and also depended on the concentration of hydrogen dioxide. The use of sperm analyzer enabled revealing changes in the diapason of different speeds of the active fraction of sperm, which have been observed in the first 15 min of incubation with hydrogen dioxide. A possible mechanism of action of the detected effect is discussed. Reactive oxygen species easily oxidize enzyme for glyceraldehyde-3-phosphate dehydrogenase of sperms, which leads to a loss of sperm motility, for example, in varicocele. Initially low enzyme activity in varicocele (pathozoospermia may be associated with the suppression of sperm antioxidant defense. Addition of low concentrations of hydrogen dioxide into sperm samples leads to an increase in the concentration of reduced glutathione in a cell. Increase of sperm motility in this case can serve as an indicator of normal operation of the cellular antioxidant defense system. Obtained experimental results provide a background for their introduction into clinical practice in the program of assisted reproductive technologies. 

  12. Sperm motility under exposure of hydrogen dioxide

    Directory of Open Access Journals (Sweden)

    V. V. Evdokimov

    2015-04-01

    Full Text Available The paper contains research data on the effect of low concentrations of hydrogen dioxide on human sperm motility and specific enzyme activity of sperms of glyceraldehyde-3-phosphate dehydrogenase. It is shown that incubation of sperms with hydrogen dioxide in a low concentration leads to a change and motility in sperm and activity of sperm enzyme. Intensity of observed effect depended on the concentration of hydrogen dioxide: active mobility increased by 17–19 % and the total mobility – 11 %. Motility changes in sperms were accompanied by increased activity of glyceraldehyde-3-phosphate dehydrogenase by 24 %, in normozoospermia response was higher than in pathozoospermia and also depended on the concentration of hydrogen dioxide. The use of sperm analyzer enabled revealing changes in the diapason of different speeds of the active fraction of sperm, which have been observed in the first 15 min of incubation with hydrogen dioxide. A possible mechanism of action of the detected effect is discussed. Reactive oxygen species easily oxidize enzyme for glyceraldehyde-3-phosphate dehydrogenase of sperms, which leads to a loss of sperm motility, for example, in varicocele. Initially low enzyme activity in varicocele (pathozoospermia may be associated with the suppression of sperm antioxidant defense. Addition of low concentrations of hydrogen dioxide into sperm samples leads to an increase in the concentration of reduced glutathione in a cell. Increase of sperm motility in this case can serve as an indicator of normal operation of the cellular antioxidant defense system. Obtained experimental results provide a background for their introduction into clinical practice in the program of assisted reproductive technologies. 

  13. Metallic Hydrogen

    Science.gov (United States)

    Silvera, Isaac; Zaghoo, Mohamed; Salamat, Ashkan

    2015-03-01

    Hydrogen is the simplest and most abundant element in the Universe. At high pressure it is predicted to transform to a metal with remarkable properties: room temperature superconductivity, a metastable metal at ambient conditions, and a revolutionary rocket propellant. Both theory and experiment have been challenged for almost 80 years to determine its condensed matter phase diagram, in particular the insulator-metal transition. Hydrogen is predicted to dissociate to a liquid atomic metal at multi-megabar pressures and T =0 K, or at megabar pressures and very high temperatures. Thus, its predicted phase diagram has a broad field of liquid metallic hydrogen at high pressure, with temperatures ranging from thousands of degrees to zero Kelvin. In a bench top experiment using static compression in a diamond anvil cell and pulsed laser heating, we have conducted measurements on dense hydrogen in the region of 1.1-1.7 Mbar and up to 2200 K. We observe a first-order phase transition in the liquid phase, as well as sharp changes in optical transmission and reflectivity when this phase is entered. The optical signature is that of a metal. The mapping of the phase line of this transition is in excellent agreement with recent theoretical predictions for the long-sought plasma phase transition to metallic hydrogen. Research supported by the NSF, Grant DMR-1308641, the DOE Stockpile Stewardship Academic Alliance Program, Grant DE-FG52-10NA29656, and NASA Earth and Space Science Fellowship Program, Award NNX14AP17H.

  14. Triphenyl phosphate allergy from spectacle frames

    DEFF Research Database (Denmark)

    Carlsen, Lars; Andersen, Klaus E.; Egsgaard, Helge

    1986-01-01

    A case of triphenyl phosphate allergy from spectacle frames is reported. Patch tests with analytical grade triphenyl phosphate, tri-m-cresyl phosphate, and tri-p-cresyl phosphate in the concentrations 5%, 0.5% and 0.05% pet. showed positive reactions to 0.05% triphenyl phosphate and 0.5% tri......-m-cresyl phosphate, but no reaction to tri-p-cresyl phosphate. Gas chromatography of the tricresyl phosphate 5% pet. patch test material supplied from Trolab showed that it contained a mixture of a wide range of triaryl phosphates, including 0.08% triphenyl phosphate which is above the threshold for detecting...... triphenyl phosphate allergy in our patient....

  15. Calcium phosphates for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Canillas, M.; Pena, P.; Aza, A.H. de; Rodriguez, M.A.

    2017-07-01

    The history of calcium phosphates in the medicine field starts in 1769 when the first evidence of its existence in the bone tissue is discovered. Since then, the interest for calcium phosphates has increased among the scientific community. Their study has been developed in parallel with new advances in materials sciences, medicine or tissue engineering areas. Bone tissue engineering is the field where calcium phosphates have had a great importance. While the first bioceramics are selected according to bioinert, biocompatibility and mechanical properties with the aim to replace bone tissue damaged, calcium phosphates open the way to the bone tissue regeneration challenge. Nowadays, they are present in the majority of commercial products directed to repair or regenerate damaged bone tissue. Finally, in the last few decades, they have been suggested and studied as drug delivering devices and as vehicles of DNA and RNA for the future generation therapies. (Author)

  16. Variability of nitrate and phosphate

    Digital Repository Service at National Institute of Oceanography (India)

    Sardessai, S.; Sundar, D.

    Nitrate and phosphate are important elements of the biogeochemical system of an estuary. Observations carried out during the dry season April-May 2002, and March 2003 and wet season September 2002, show temporal and spatial variability of these two...

  17. Recent advances in phosphate biosensors.

    Science.gov (United States)

    Upadhyay, Lata Sheo Bachan; Verma, Nishant

    2015-07-01

    A number of biosensors have been developed for phosphate analysis particularly, concerning its negative impact within the environmental and biological systems. Enzymatic biosensors comprising either a single or multiple enzymatic system have been extensively used for the direct and indirect analysis of phosphate ions. Furthermore, some non-enzymatic biosensors, such as affinity-based biosensors, provide an alternative analytical approach with a higher selectivity. This article reviews the recent advances in the field of biosensor developed for phosphate estimation in clinical and environmental samples, concerning the techniques involved, and the sensitivity toward phosphate ions. The biosensors have been classified and discussed on the basis of the number of enzymes used to develop the analytical system, and a comparative analysis has been performed.

  18. 21 CFR 573.320 - Diammonium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Diammonium phosphate. 573.320 Section 573.320 Food... Additive Listing § 573.320 Diammonium phosphate. The food additive diammonium phosphate may be safely used... crude protein from diammonium phosphate, adequate directions for use and a prominent statement,...

  19. 21 CFR 184.1434 - Magnesium phosphate.

    Science.gov (United States)

    2010-04-01

    ... solution of magnesite with phosphoric acid. (b) Magnesium phosphate, dibasic, meets the specifications of... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Magnesium phosphate. 184.1434 Section 184.1434 Food... Specific Substances Affirmed as GRAS § 184.1434 Magnesium phosphate. (a) Magnesium phosphate includes...

  20. FORMATION OF PHOSPHATE-CONTAINING CALCIUM-FLUORIDE AT THE EXPENSE OF ENAMEL, HYDROXYAPATITE AND FLUORAPATITE

    NARCIS (Netherlands)

    CHRISTOFFERSEN, J; CHRISTOFFERSEN, MR; ARENDS, J; LEONARDSEN, ES

    1995-01-01

    During the caries process complex reactions involving calcium, phosphate, hydrogen and fluoride ions as main species take place. In this study the precipitation and dissolution reactions occurring in suspensions of enamel, hydroxyapatite (HAP) and fluorapatite (FAP) on addition of fluoride were inve

  1. FORMATION OF PHOSPHATE-CONTAINING CALCIUM-FLUORIDE AT THE EXPENSE OF ENAMEL, HYDROXYAPATITE AND FLUORAPATITE

    NARCIS (Netherlands)

    CHRISTOFFERSEN, J; CHRISTOFFERSEN, MR; ARENDS, J; LEONARDSEN, ES

    1995-01-01

    During the caries process complex reactions involving calcium, phosphate, hydrogen and fluoride ions as main species take place. In this study the precipitation and dissolution reactions occurring in suspensions of enamel, hydroxyapatite (HAP) and fluorapatite (FAP) on addition of fluoride were

  2. Novel Hydrogen Bioreactor and Detection Apparatus.

    Science.gov (United States)

    Rollin, Joseph A; Ye, Xinhao; Del Campo, Julia Martin; Adams, Michael W W; Zhang, Y-H Percival

    2016-01-01

    In vitro hydrogen generation represents a clear opportunity for novel bioreactor and system design. Hydrogen, already a globally important commodity chemical, has the potential to become the dominant transportation fuel of the future. Technologies such as in vitro synthetic pathway biotransformation (SyPaB)-the use of more than 10 purified enzymes to catalyze unnatural catabolic pathways-enable the storage of hydrogen in the form of carbohydrates. Biohydrogen production from local carbohydrate resources offers a solution to the most pressing challenges to vehicular and bioenergy uses: small-size distributed production, minimization of CO2 emissions, and potential low cost, driven by high yield and volumetric productivity. In this study, we introduce a novel bioreactor that provides the oxygen-free gas phase necessary for enzymatic hydrogen generation while regulating temperature and reactor volume. A variety of techniques are currently used for laboratory detection of biohydrogen, but the most information is provided by a continuous low-cost hydrogen sensor. Most such systems currently use electrolysis for calibration; here an alternative method, flow calibration, is introduced. This system is further demonstrated here with the conversion of glucose to hydrogen at a high rate, and the production of hydrogen from glucose 6-phosphate at a greatly increased reaction rate, 157 mmol/L/h at 60 °C.

  3. Hydrogen as a fuel

    Energy Technology Data Exchange (ETDEWEB)

    1979-01-01

    A panel of the Committee on Advanced Energy Storage Systems of the Assembly of Engineering has examined the status and problems of hydrogen manufacturing methods, hydrogen transmission and distribution networks, and hydrogen storage systems. This examination, culminating at a time when rapidly changing conditions are having noticeable impact on fuel and energy availability and prices, was undertaken with a view to determining suitable criteria for establishing the pace, timing, and technical content of appropriate federally sponsored hydrogen R and D programs. The increasing urgency to develop new sources and forms of fuel and energy may well impact on the scale and timing of potential future hydrogen uses. The findings of the panel are presented. Chapters are devoted to hydrogen sources, hydrogen as a feedstock, hydrogen transport and storage, hydrogen as a heating fuel, automotive uses of hydrogen, aircraft use of hydrogen, the fuel cell in hydrogen energy systems, hydrogen research and development evaluation, and international hydrogen programs.

  4. The hydrogen; L'hydrogene

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    The hydrogen as an energy system represents nowadays a main challenge (in a scientific, economical and environmental point of view). The physical and chemical characteristics of hydrogen are at first given. Then, the challenges of an hydrogen economy are explained. The different possibilities of hydrogen production are described as well as the distribution systems and the different possibilities of hydrogen storage. Several fuel cells are at last presented: PEMFC, DMFC and SOFC. (O.M.)

  5. Recognizing the Effects of Terrestrial Contamination on D/H Ratios in Shergottite Phosphates

    Science.gov (United States)

    Ross, D. K.; Ito, M.; Hervig, R.; Rao, M. N.; Nyquist, L. E.

    2011-01-01

    Hydrogen isotope ratios in shergottite phosphate minerals have been investigated by SIMS in the meteorites Queen Alexandra Range (QUE) 94201 and Los Angeles. We have also collected electron probe data on these phosphates in order to characterize the phosphate minerals and attempt to document any potential hydrogen isotopic differences between chlor-apatite and whitlockite. In the section of Los Angeles we studied (748), we found both chlor-apatite and whitlockite, but in the section of QUE 94201,38 studied, we found only whitlockite. In both meteorites, D/H ratios (expressed in units of delta D (sub SMOW) vary, from terrestrial values up to approximately 5400%o in QUE 94201, and to approximately 3800%o in Los Angeles. We have carefully examined the ion probed pits with high-resolution FE-SEM. In most cases where the D/H ratios are low, we have iden-tified cracks that instersect the ion probe pit. These cracks are not visible in the optical microscope attached to the SIMS instument, making them impossible to avoid during SIMS data collection. We contend that the low ratios are a function of substantial terrestrial contamination, and that similar contamination is a likely factor in previously published studies on D/H ratios in martian phosphates. Here we highlight the difficulty of attempts to constrain the martian mantle D/H ratio using phosphate data, given that both terrestrial contamination and martian mantle hydrogen will move phosphate D/H ratios in the same direction, toward lower values. We note that our data include some of the most deuterium-rich values ever reported for martian phosphates. It is clear that some of our measurements are only minimally or totally uncontaminated, but the question arises, are intermediate values diminished because of true martian variability, or do they reflect contamination?

  6. Thermally highly stable amorphous zinc phosphate intermediates during the formation of zinc phosphate hydrate.

    Science.gov (United States)

    Bach, Sven; Celinski, Vinicius R; Dietzsch, Michael; Panthöfer, Martin; Bienert, Ralf; Emmerling, Franziska; Schmedt auf der Günne, Jörn; Tremel, Wolfgang

    2015-02-18

    The mechanisms by which amorphous intermediates transform into crystalline materials are still poorly understood. Here we attempt to illuminate the formation of an amorphous precursor by investigating the crystallization process of zinc phosphate hydrate. This work shows that amorphous zinc phosphate (AZP) nanoparticles precipitate from aqueous solutions prior to the crystalline hopeite phase at low concentrations and in the absence of additives at room temperature. AZP nanoparticles are thermally stable against crystallization even at 400 °C (resulting in a high temperature AZP), but they crystallize rapidly in the presence of water if the reaction is not interrupted. X-ray powder diffraction with high-energy synchrotron radiation, scanning and transmission electron microscopy, selected area electron diffraction, and small-angle X-ray scattering showed the particle size (≈20 nm) and confirmed the noncrystallinity of the nanoparticle intermediates. Energy dispersive X-ray, infrared, and Raman spectroscopy, inductively coupled plasma mass spectrometry, and optical emission spectrometry as well as thermal analysis were used for further compositional characterization of the as synthesized nanomaterial. (1)H solid-state NMR allowed the quantification of the hydrogen content, while an analysis of (31)P{(1)H} C rotational echo double resonance spectra permitted a dynamic and structural analysis of the crystallization pathway to hopeite.

  7. Synthesis of nanocrystalline calcium phosphate in microemulsion--effect of nature of surfactants.

    Science.gov (United States)

    Singh, Sujata; Bhardwaj, Pallavi; Singh, V; Aggarwal, S; Mandal, U K

    2008-03-01

    Nanosized calcium phosphate (CP) powders have been synthesized by an inverse microemulsion system using kerosene as the oil phase, a cationic surfactant Aliquat 336, a non-ionic surfactant Tween 20 and their mixture and aqueous solutions of calcium nitrate tetrahydrate and biammonium hydrogen phosphate as the water phase. It has been found that the nature of surfactants played an important role to regulate the size and morphologies of the calcium phosphate nanoparticles. The cationic surfactant Aliquat 336 has been found to regulate the nucleation and crystal growth. The synthesized powders have been comprehensively characterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM), powder X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). Our results show that the brushite (DCPD) is the major phase comprising the calcium phosphate nanoparticles. In mixed surfactants mediated system a morphological controlled highly crystalline particles have been synthesized. Further, the role of Aliquat 336 has been established and a plausible synthetic mechanism has been proposed.

  8. Effectiveness of nano-calcium phosphate paste on sensitivity during and after bleaching: a randomized clinical trial

    OpenAIRE

    LOGUERCIO, Alessandro Dourado; Lidia Yileng TAY; HERRERA,Daniel Rodrigo; Bauer,Jose; Reis, Alessandra

    2015-01-01

    The study aimed to evaluate the effectiveness of in-office bleaching and associated tooth sensitivity on application of nano-calcium phosphate paste as desensitizing agent. Bleaching was performed with 35% hydrogen peroxide gel in 40 patients who were randomly divided into placebo and nano-calcium phosphate paste groups. Bleaching efficacy (BE) was evaluated using a value-oriented Vita shade guide. Tooth sensitivity was recorded using a numeric rating scale (0–4) during bleaching and up...

  9. Surface chemistry studies of phosphate glasses

    Science.gov (United States)

    Barnes, Amy Suzanne

    This research examined the surface of an undoped and rare-earth doped sodium alumino metaphosphate glass after fracture or surface finishing and subsequent exposure to humid and aqueous environments. In addition, the adsorption of aminopropyl triethoxysilane (APS), and the dominant parameters controlling the structure of the deposited film, were studied. Typically, commercial glasses must be cut and polished into optical components for engineering applications. This process involves a series of aqueous treatments in both acidic and basic media. The experiments performed here on aluminophosphate glass showed that this results in dissolution, surface composition changes (depletion of Na) and surface pitting. In both alkaline detergent and acid etching solution, dissolution at a rate of approximately 4 x 10 -3 mol/m2/hr (0.2 mum/hr) occurs along with a drastic alteration of the surface morphology. When exposed to an environment of elevated humidity and temperature for an extended period of time, this aluminophosphate glass was observed to break down, forming a soluble phosphate gel that dissolves away from the surface. Simultaneously, the surface became enriched in silica, a trace contaminant in the glass, which eventually precipitated and coalesced into a dendritic pattern that covered the surface. The freshly powdered phosphate glass was found to contain surface hydroxyls weakly associated with one another, and some bound by a stronger hydrogen bond, likely to adjacent non-bridging oxygens. Most of these hydroxyls could be desorbed upon heating above the glass transition temperature to leave only a small concentration of weakly associated hydroxyls and free hydroxyls on the surface. The characterization of hydroxyls and water on the phosphate glass surface was used to understand the adsorption of aminopropyl tri-ethoxysilane (APS) also through the use of in-situ DRIFTS. The concentration of adsorbed APS was found to be independent of solution pH, but the measured

  10. Formation of phosphatidylinositol 3-phosphate by isomerization from phosphatidylinositol 4-phosphate.

    OpenAIRE

    Walsh, J P; Caldwell, K K; Majerus, P W

    1991-01-01

    We have synthesized phosphatidylinositol 3-phosphate from phosphatidylinositol 4-phosphate by using diisopropylcarbodiimide to promote migration of the 4-phosphate via a cyclic phosphodiester intermediate. The product was isolated by a thin-layer chromatographic method that depends on the ability of phosphatidylinositol 4-phosphate, but not phosphatidylinositol 3-phosphate, to form complexes with boric acid. The final yield of the procedure was 8% phosphatidylinositol 3-phosphate, which was a...

  11. Decontamination of liquid radioactive waste by thorium phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Rousselle, J.; Grandjean, S.; Dacheux, N.; Genet, M

    2004-07-01

    In the field of the complete reexamination of the chemistry of thorium phosphate and of the improvement of the homogeneity of Thorium Phosphate Diphosphate (TPD, Th{sub 4}(PO{sub 4}){sub 4}P{sub 2}O{sub 7}) prepared at high temperature, several crystallized compounds were prepared as initial powdered precursors. Due to the very low solubility products associated to these phases, their use in the field of the efficient decontamination of high-level radioactive liquid waste containing actinides (An) was carefully considered. Two main processes (called 'oxalate' and 'hydrothermal' chemical routes) were developed through a new concept combining the decontamination of liquid waste and the immobilization of the actinides in a ceramic matrix (TPD). In phosphoric media ('hydrothermal route'), the key-precursor was the Thorium Phosphate Hydrogen Phosphate hydrate (Th{sub 2}(PO{sub 4}){sub 2}(HPO{sub 4}). H{sub 2}O, TPHP, solubility product log(K{sub S,0}{sup 0}) {approx} - 67). The replacement of thorium by other tetravalent actinides (U, Np, Pu) in the structure, leading to the preparation of Th{sub 2-x/2}An{sub x/2}(PO{sub 4}){sub 2}(HPO{sub 4}). H{sub 2}O solid solutions, was examined. A second method was also considered in parallel to illustrate this concept using the more well-known precipitation of oxalate as the initial decontamination step. For this method, the final transformation to single phase TPD containing actinides was purchased by heating a mixture of phosphate ions with the oxalate precipitate at high temperature. (authors)

  12. [Phosphate metabolism and iron deficiency].

    Science.gov (United States)

    Yokoyama, Keitaro

    2016-02-01

    Autosomal dominant hypophosphatemic rickets(ADHR)is caused by gain-of-function mutations in FGF23 that prevent its proteolytic cleavage. Fibroblast growth factor 23(FGF23)is a hormone that inhibits renal phosphate reabsorption and 1,25-dihydroxyvitamin D biosynthesis. Low iron status plays a role in the pathophysiology of ADHR. Iron deficiency is an environmental trigger that stimulates FGF23 expression and hypophosphatemia in ADHR. It was reported that FGF23 elevation in patients with CKD, who are often iron deficient. In patients with nondialysis-dependent CKD, treatment with ferric citrate hydrate resulted in significant reductions in serum phosphate and FGF23.

  13. Photorelease of phosphates: Mild methods for protecting phosphate derivatives

    Directory of Open Access Journals (Sweden)

    Sanjeewa N. Senadheera

    2014-08-01

    Full Text Available We have developed a new photoremovable protecting group for caging phosphates in the near UV. Diethyl 2-(4-hydroxy-1-naphthyl-2-oxoethyl phosphate (14a quantitatively releases diethyl phosphate upon irradiation in aq MeOH or aq MeCN at 350 nm, with quantum efficiencies ranging from 0.021 to 0.067 depending on the solvent composition. The deprotection reactions originate from the triplet excited state, are robust under ambient conditions and can be carried on to 100% conversion. Similar results were found with diethyl 2-(4-methoxy-1-naphthyl-2-oxoethyl phosphate (14b, although it was significantly less efficient compared with 14a. A key step in the deprotection reaction in aq MeOH is considered to be a Favorskii rearrangement of the naphthyl ketone motif of 14a,b to naphthylacetate esters 25 and 26. Disruption of the ketone-naphthyl ring conjugation significantly shifts the photoproduct absorption away from the effective incident wavelength for decaging of 14, driving the reaction to completion. The Favorskii rearrangement does not occur in aqueous acetonitrile although diethyl phosphate is released. Other substitution patterns on the naphthyl or quinolin-5-yl core, such as the 2,6-naphthyl 10 or 8-benzyloxyquinolin-5-yl 24 platforms, also do not rearrange by aryl migration upon photolysis and, therefore, do not proceed to completion. The 2,6-naphthyl ketone platform instead remains intact whereas the quinolin-5-yl ketone fragments to a much more complex, highly absorbing reaction mixture that competes for the incident light.

  14. Hydrogen in metals

    CSIR Research Space (South Africa)

    Carter, TJ

    2001-04-01

    Full Text Available of hydrogen in metals processing and treatment identified, and mechanisms for hydrogen entry into a ferritic surface are discussed. The differences between hydrogen attack of ferritic steels and copper alloys are contrasted, and an unusual case study...

  15. Phosphorus release from phosphate rock and iron phosphate by low-molecular-weight organic acids

    Institute of Scientific and Technical Information of China (English)

    XU Ren-kou; ZHU Yong-guan; David Chittleborough

    2004-01-01

    Low-molecular-weight(LMW) organic acids widely exist in soils, particularly in the rhizosphere. A series of batch experiments were carried out to investigate the phosphorus release from rock phosphate and iron phosphate by Iow-molecular-weight organic acids.Results showed that citric acid had the highest capacity to solubilize P from both rock and iron phosphate. P solubilization from rock phosphate and iron phosphate resulted in net proton consumption. P release from rock phosphate was positively correlated with the pKa values. P release from iron phosphate was positively correlated with Fe-organic acid stability constants except for aromatic acids, but was not correlated with PKa. Increase in the concentrations of organic acids enhanced P solubilization from both rock and iron phosphate almost linearrly. Addition of phenolic compounds further increased the P release from iron phosphate. Initial solution pH had much more substantial effect on P release from rock phosphate than from iron phosphate.

  16. Characterization of hydroxyphenol-terminated alkanethiol self-assembled monolayers: interactions with phosphates by chemical force spectrometry.

    Science.gov (United States)

    Azmi, Alyza A; Ebralidze, Iraklii I; Dickson, Steven E; Horton, J Hugh

    2013-03-01

    Tannins and humic substances, commonly referred to as natural organic matter (NOM), constitute an important component of natural water and soil systems. These species contain numerous hydroxyl and carboxyl functional groups whose reactivity is strongly dependent on both the quantity and location of these moieties on the aromatic ring. In the present study, self-assembled monolayers (SAMs) of 4-(12-mercaptododecyl)benzene-1,2-diol (o-hydroxyphenol-terminated); 5-(12-mercaptododecyl)benzene-1,3-diol (m-hydroxyphenol-terminated); bis(11-thioundecyl) hydrogen phosphate (monoprotic phosphate); and 11-thioundecyl dihydrogen phosphate (diprotic phosphate) were prepared and characterized using X-ray photoelectron spectroscopy (XPS), attenuated total reflectance infrared spectroscopy (ATR-IR), and water contact angle measurements. The interactions between phenolic groups with phosphates were examined as a function of pH using the chemical force spectrometry (CFS) technique. The observations are discussed in the context of hydrogen bonding and electrostatic repulsion interaction between corresponding species. Adhesion force profiles of hydroxyphenol isomers interacting with monoprotic phosphate are dominated by ionic H-bonding; however the strength of o-hydroxyphenol interactions is significantly higher. The difference in location of hydroxyl groups on the interface also results in significantly different force-distance profiles for the isomeric hydroxyphenols when interacting with diprotic phosphate.

  17. Hydrogen heat treatment of hydrogen absorbing materials

    Science.gov (United States)

    Park, Choong-Nyeon

    2000-12-01

    This study introduces the hydrogen heat treatment of hydrogen absorbing materials and its applicability for practical use. This treatment is somewhat different from normal heat treatment because of the interaction between metal atoms and hydrogen. Since hydrogen can be removed very fast by pumping it out the hydrogen-induced new lattice phase which can not be obtained without hydrogen can be preserved in a meta-stable state. A thermodynamic interpretation of the hydrogen heat treatment established previously was reformulated for graphical and analytical methods and applied to Pd-Pt-H and Pd-Ag-H alloy systems and a fair correlation between the calculation and experimental results was shown. The feasibility of applying the thermodynamic interpretation to intermetallic compounds-hydrogen systems was also discussed.

  18. SCALEUP OF ALUMINUM PHOSPHATE CATALYST FOR PILOT PLANT LPDMEtm RUN

    Energy Technology Data Exchange (ETDEWEB)

    Andrew W. Wang

    2002-01-01

    The Liquid Phase Dimethyl Ether (LPDME{trademark}) process converts synthesis gas to dimethyl ether in a single slurry bubble column reactor. A mixed slurry of methanol synthesis catalyst and methanol dehydration catalyst in a neutral mineral oil simultaneously synthesizes methanol from syngas and converts some of it to dimethyl ether and water. The reaction scheme is shown below: 2H{sub 2} + CO = CH{sub 3}OH; 2CH{sub 3}OH = CH{sub 3}OCH{sub 3} + H{sub 2}O; H{sub 2}O + CO = CO{sub 2} + H{sub 2}. Most of the water produced in this reaction is converted to hydrogen by reduction with carbon monoxide (water gas shift reaction). This synergy permits higher per pass conversion than methanol synthesis alone. The enhancement in conversion occurs because dehydration of the methanol circumvents the equilibrium constraint of the syngas-to-methanol step. The slurry bubble column reactor provides the necessary heat transfer capacity to handle the greater heat duty associated with high conversion. In order to improve the stability of the catalyst system, non-stoichiometric aluminum phosphate was proposed as the dehydration catalyst for the LPDME{trademark} process. This aluminum phosphate material is a proprietary catalyst. This catalyst system of a standard methanol catalyst and the aluminum phosphate provided stable process performance that met the program targets under our standard test process conditions in the laboratory. These targets are (1) an initial methanol equivalent productivity of 28 gmol/kg/hr, (2) a CO{sub 2}-free, carbon selectivity of 80% to dimethyl ether and (3) stability of both catalysts equivalent to that of the methanol catalyst in the absence of the aluminum phosphate. A pilot plant trial of the LPDME{trademark} process using the aluminum phosphate catalyst was originally planned for March 1998 at the DOE-owned, Air Products (APCI)-operated facility at LaPorte, Texas. Because the aluminum phosphate catalyst is not commercially available, we initiated a

  19. SCALEUP OF ALUMINUM PHOSPHATE CATALYST FOR PILOT PLANT LPDMEtm RUN

    Energy Technology Data Exchange (ETDEWEB)

    Andrew W. Wang

    2002-05-15

    The Liquid Phase Dimethyl Ether (LPDME{trademark}) process converts synthesis gas to dimethyl ether in a single slurry bubble column reactor. A mixed slurry of methanol synthesis catalyst and methanol dehydration catalyst in a neutral mineral oil simultaneously synthesizes methanol from syngas and converts some of it to dimethyl ether and water. The reaction scheme is: 2H{sub 2} + CO = CH{sub 3}OH 2CH{sub 3}OH = CH{sub 3}OCH{sub 3} + H{sub 2}O H{sub 2}O + CO = CO{sub 2} + H{sub 2}. Most of the water produced in this reaction is converted to hydrogen by reduction with carbon monoxide (water gas shift reaction). This synergy permits higher per pass conversion than methanol synthesis alone. The enhancement in conversion occurs because dehydration of the methanol circumvents the equilibrium constraint of the syngas-to-methanol step. The slurry bubble column reactor provides the necessary heat transfer capacity to handle the greater heat duty associated with high conversion. In order to improve the stability of the catalyst system, non-stoichiometric aluminum phosphate was proposed as the dehydration catalyst for the LPDME{trademark} process. This aluminum phosphate material is a proprietary catalyst. This catalyst system of a standard methanol catalyst and the aluminum phosphate provided stable process performance that met the program targets under our standard test process conditions in the laboratory. These targets are (1) an initial methanol equivalent productivity of 28 gmol/kg/hr, (2) a CO{sub 2}-free, carbon selectivity of 80% to dimethyl ether and (3) stability of both catalysts equivalent to that of the methanol catalyst in the absence of the aluminum phosphate. A pilot plant trial of the LPDME{trademark} process using the aluminum phosphate catalyst was originally planned for March 1998 at the DOE-owned, Air Products (APCI)-operated facility at LaPorte, Texas. Because the aluminum phosphate catalyst is not commercially available, we initiated a scaleup project

  20. Zinc phosphate as versatile material for potential biomedical applications Part 1.

    Science.gov (United States)

    Herschke, L; Rottstegge, J; Lieberwirth, I; Wegner, G

    2006-01-01

    Synthetic alpha - and beta -Hopeite, two polymorphs of zinc phosphate tetrahydrates (ZPT) have been synthesized by hydrothermal crystallization from aqueous solution at 20 degrees C and 90 degrees C respectively. Aside from their sub-title crystallographic differences originating from a unique hydrogen bonding pattern, their thermodynamic interrelation has been thoroughfully investigated by means of X-Ray diffraction (XRD) and differential scanning calorimetry (DSC), combined with thermogravimetry (TGA-MS). Using a new heterogeneous step-reaction approach, the kinetics of dehydration of the two forms of ZPT was studied and their corresponding transition temperature determined. Low temperature DRIFT, FT-Raman and (1)H, (31)P MAS-NMR reveal an oriented distortion of the zinc phosphate tetrahedra, due to a characteristic hydrogen bonding pattern and in accordance with the molecular tetrahedral linkage scheme of the phosphate groups. Biogenic Hydroxyapatite (HAP) and one of its metastable precursors, a calcium dihydrogen phosphate dihydrate (DCPD) or Brushite were also obtained and used to underline the resulting variations of chemical reactivity in zinc phosphates.

  1. Phosphate Recognition in Structural Biology

    NARCIS (Netherlands)

    Hirsch, Anna K.H.; Fischer, Felix R.; Diederich, François

    2007-01-01

    Drug-discovery research in the past decade has seen an increased selection of targets with phosphate recognition sites, such as protein kinases and phosphatases, in the past decade. This review attempts, with the help of database-mining tools, to give an overview of the most important principles in

  2. Sintering of calcium phosphate bioceramics.

    Science.gov (United States)

    Champion, E

    2013-04-01

    Calcium phosphate ceramics have become of prime importance for biological applications in the field of bone tissue engineering. This paper reviews the sintering behaviour of these bioceramics. Conventional pressureless sintering of hydroxyapatite, Ca10(PO4)6(OH)2, a reference compound, has been extensively studied. Its physico-chemistry is detailed. It can be seen as a competition between two thermally activated phenomena that proceed by solid-state diffusion of matter: densification and grain growth. Usually, the objective is to promote the first and prevent the second. Literature data are analysed from sintering maps (i.e. grain growth vs. densification). Sintering trajectories of hydroxyapatite produced by conventional pressureless sintering and non-conventional techniques, including two-step sintering, liquid phase sintering, hot pressing, hot isostatic pressing, ultrahigh pressure, microwave and spark plasma sintering, are presented. Whatever the sintering technique may be, grain growth occurs mainly during the last step of sintering, when the relative bulk density reaches 95% of the maximum value. Though often considered very advantageous, most assisted sintering techniques do not appear very superior to conventional pressureless sintering. Sintering of tricalcium phosphate or biphasic calcium phosphates is also discussed. The chemical composition of calcium phosphate influences the behaviour. Similarly, ionic substitutions in hydroxyapatite or in tricalcium phosphate create lattice defects that modify the sintering rate. Depending on their nature, they can either accelerate or slow down the sintering rate. The thermal stability of compounds at the sintering temperature must also be taken into account. Controlled atmospheres may be required to prevent thermal decomposition, and flash sintering techniques, which allow consolidation at low temperature, can be helpful.

  3. Phosphate based oil well cements

    Science.gov (United States)

    Natarajan, Ramkumar

    The main application of the cement in an oil well is to stabilize the steel casing in the borehole and protect it from corrosion. The cement is pumped through the borehole and is pushed upwards through the annulus between the casing and the formation. The cement will be exposed to temperature and pressure gradients of the borehole. Modified Portland cement that is being used presently has several shortcomings for borehole sealant. The setting of the Portland cement in permafrost regions is poor because the water in it will freeze even before the cement sets and because of high porosity and calcium oxide, a major ingredient it gets easily affected by the down hole gases such as carbon dioxide. The concept of phosphate bonded cements was born out of considerable work at Argonne National Laboratory (ANL) on their use in stabilization of radioactive and hazardous wastes. Novel cements were synthesized by an acid base reaction between a metal oxide and acid phosphate solution. The major objective of this research is to develop phosphate based oil well cements. We have used thermodynamics along with solution chemistry principles to select calcined magnesium oxide as candidate metal oxide for temperatures up to 200°F (93.3°C) and alumina for temperatures greater than 200°F (93.3°C). Solution chemistry helped us in selecting mono potassium phosphate as the acid component for temperatures less than 200°F (93.3°C) and phosphoric acid solution greater than 200°F (93.3°C). These phosphate cements have performance superior to common Portland well cements in providing suitable thickening time, better mechanical and physical properties.

  4. 21 CFR 184.1301 - Ferric phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ferric phosphate. 184.1301 Section 184.1301 Food... Specific Substances Affirmed as GRAS § 184.1301 Ferric phosphate. (a) Ferric phosphate (ferric orthophosphate, iron (III) phosphate, FePO4·xH2O, CAS Reg. No. 10045-86-0) is an odorless, yellowish-white...

  5. Tribology in Gaseous Hydrogen

    Science.gov (United States)

    Sawae, Yoshinori; Sugimura, Joich

    Hydrogen is expected as a clean and renewable energy carrier for future environment-friendly society. Many machine elements in hydrogen energy systems should be operating within hydrogen gas and tribological behavior, such as friction and wear, of bearings and seals are affected by the hydrogen environment through some interactions between material surfaces and gaseous hydrogen, i.e., physisorption of hydrogen molecules and following chemisorptions of dissociated atoms on metal surfaces, formation of metal hydride and reduction of metal oxide layer by hydrogen atoms diffused into bulk. Therefore, friction and wear characteristics of tribomaterials in the hydrogen environment should be appropriately understood to establish a design guideline for reliable hydrogen utilizing systems. This paper reviews the current knowledge about the effect of hydrogen on friction and wear of materials, and then describes our recent progress of hydrogen research in the tribology field.

  6. 21 CFR 182.1778 - Sodium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium phosphate. 182.1778 Section 182.1778 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Substances § 182.1778 Sodium phosphate. (a) Product. Sodium phosphate (mono-, di-, and tribasic)....

  7. 21 CFR 582.5301 - Ferric phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ferric phosphate. 582.5301 Section 582.5301 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5301 Ferric phosphate. (a) Product. Ferric phosphate. (b) Conditions of use....

  8. 21 CFR 182.8778 - Sodium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium phosphate. 182.8778 Section 182.8778 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... phosphate. (a) Product. Sodium phosphate (mono-, di-, and tribasic). (b) Conditions of use. This...

  9. 21 CFR 582.6778 - Sodium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sodium phosphate. 582.6778 Section 582.6778 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Sodium phosphate. (a) Product. Sodium phosphate (mono-, di-, and tribasic). (b) Conditions of use....

  10. 21 CFR 582.1778 - Sodium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sodium phosphate. 582.1778 Section 582.1778 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1778 Sodium phosphate. (a) Product. Sodium phosphate (mono-, di-, and tribasic)....

  11. 21 CFR 582.5778 - Sodium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sodium phosphate. 582.5778 Section 582.5778 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5778 Sodium phosphate. (a) Product. Sodium phosphate (mono-, di-, and tribasic)....

  12. 21 CFR 182.6778 - Sodium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium phosphate. 182.6778 Section 182.6778 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... phosphate. (a) Product. Sodium phosphate (mono-, di-, and tribasic). (b) Conditions of use. This...

  13. 21 CFR 582.5217 - Calcium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium phosphate. 582.5217 Section 582.5217 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5217 Calcium phosphate. (a) Product. Calcium phosphate (mono-, di-, and tribasic)....

  14. 21 CFR 182.8217 - Calcium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium phosphate. 182.8217 Section 182.8217 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... phosphate. (a) Product. Calcium phosphate (mono-, di-, and tribasic). (b) Conditions of use. This...

  15. 40 CFR 721.5995 - Polyalkyl phosphate.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polyalkyl phosphate. 721.5995 Section... Substances § 721.5995 Polyalkyl phosphate. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a polyalkyl phosphate (PMN P-95-1772)...

  16. 21 CFR 582.6285 - Dipotassium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Dipotassium phosphate. 582.6285 Section 582.6285 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Dipotassium phosphate. (a) Product. Dipotassium phosphate. (b) Conditions of use. This substance is...

  17. 21 CFR 582.1141 - Ammonium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ammonium phosphate. 582.1141 Section 582.1141 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1141 Ammonium phosphate. (a) Product. Ammonium phosphate (mono- and dibasic). (b)...

  18. 21 CFR 582.1217 - Calcium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium phosphate. 582.1217 Section 582.1217 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1217 Calcium phosphate. (a) Product. Calcium phosphate (mono-, di-, and tribasic)....

  19. 21 CFR 582.6290 - Disodium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Disodium phosphate. 582.6290 Section 582.6290 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Disodium phosphate. (a) Product. Disodium phosphate. (b) Conditions of use. This substance is...

  20. 21 CFR 182.1217 - Calcium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium phosphate. 182.1217 Section 182.1217 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Substances § 182.1217 Calcium phosphate. (a) Product. Calcium phosphate (mono-, di-, and tribasic)....

  1. 21 CFR 582.5434 - Magnesium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Magnesium phosphate. 582.5434 Section 582.5434 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5434 Magnesium phosphate. (a) Product. Magnesium phosphate (di- and tribasic)....

  2. 21 CFR 182.6285 - Dipotassium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Dipotassium phosphate. 182.6285 Section 182.6285 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD... Dipotassium phosphate. (a) Product. Dipotassium phosphate. (b) Conditions of use. This substance is...

  3. 21 CFR 182.6290 - Disodium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Disodium phosphate. 182.6290 Section 182.6290 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... phosphate. (a) Product. Disodium phosphate. (b) Conditions of use. This substance is generally recognized...

  4. Molecular mechanisms of crystallization impacting calcium phosphate cements

    Science.gov (United States)

    Giocondi, Jennifer L.; El-Dasher, Bassem S.; Nancollas, George H.; Orme, Christine A.

    2010-01-01

    The biomineral calcium hydrogen phosphate dihydrate (CaHPO4·2H2O), known as brushite, is a malleable material that both grows and dissolves faster than most other calcium minerals, including other calcium phosphate phases, calcium carbonates and calcium oxalates. Within the body, this ready formation and dissolution can play a role in certain diseases, such as kidney stone and plaque formation. However, these same properties, along with brushite’s excellent biocompatibility, can be used to great benefit in making resorbable biomedical cements. To optimize cements, additives are commonly used to control crystallization kinetics and phase transformation. This paper describes the use of in situ scanning probe microscopy to investigate the role of several solution parameters and additives in brushite atomic step motion. Surprisingly, this work demonstrates that the activation barrier for phosphate (rather than calcium) incorporation limits growth kinetics and that additives such as magnesium, citrate and bisphosphonates each influence step motion in distinctly different ways. Our findings provide details of how, and where, molecules inhibit or accelerate kinetics. These insights have the potential to aid in designing molecules to target specific steps and to guide synergistic combinations of additives. PMID:20308110

  5. Molecular mechanisms of crystallization impacting calcium phosphate cements.

    Science.gov (United States)

    Giocondi, Jennifer L; El-Dasher, Bassem S; Nancollas, George H; Orme, Christine A

    2010-04-28

    The biomineral calcium hydrogen phosphate dihydrate (CaHPO(4).2H(2)O), known as brushite, is a malleable material that both grows and dissolves faster than most other calcium minerals, including other calcium phosphate phases, calcium carbonates and calcium oxalates. Within the body, this ready formation and dissolution can play a role in certain diseases, such as kidney stone and plaque formation. However, these same properties, along with brushite's excellent biocompatibility, can be used to great benefit in making resorbable biomedical cements. To optimize cements, additives are commonly used to control crystallization kinetics and phase transformation. This paper describes the use of in situ scanning probe microscopy to investigate the role of several solution parameters and additives in brushite atomic step motion. Surprisingly, this work demonstrates that the activation barrier for phosphate (rather than calcium) incorporation limits growth kinetics and that additives such as magnesium, citrate and bisphosphonates each influence step motion in distinctly different ways. Our findings provide details of how, and where, molecules inhibit or accelerate kinetics. These insights have the potential to aid in designing molecules to target specific steps and to guide synergistic combinations of additives.

  6. Injectability and mechanical properties of magnesium phosphate cements.

    Science.gov (United States)

    Moseke, Claus; Saratsis, Vasileios; Gbureck, Uwe

    2011-12-01

    Up to now magnesium phosphate cements are mainly being utilized in wastewater treatment due to their adsorptive properties. Recently they also have been shown to have a high potential as degradable biocements for application as replacement materials for bone defects. In comparison to degradable calcium phosphate cements they have the advantage of setting at neutral pH, which is favorable in biological environment. In this study two parameters of the cement composition, namely powder-to-liquid ratio (PLR) and citrate content, were varied in order to optimize the injectability properties of the cement paste and the mechanical properties of the reaction product. These properties were determined by means of testing setting time and temperature, paste viscosity, and injectability as well as phase composition and compressive strength of the set cements. Best results were obtained, when the cements were prepared with a PLR of 2.5 and a binder liquid consisting of an aqueous solution of 3 mol/l diammonium hydrogen phosphate and 0.5 mol/l diammonium citrate.

  7. Novel vanadium phosphate phases as catalysts for selective oxidation

    Indian Academy of Sciences (India)

    Arunabha Datta; Monika Agarwal; Soumen Dasgupta

    2002-08-01

    In our effort to induce novel modifications in the structure of some important vanadium phosphate phases used as selective oxidation catalysts, it has been observed that metal ions such as Zn2+, Ni2+, Pd2+ can be incorporated into the vanadyl hydrogen phosphate VOHPO4$\\cdot$0.5H2O phase in very different ways depending upon the medium of preparation. It has been found that the metal ions are either substituted into the lattice with retention of structure of the parent compound or intercalated between the layers of a new mixed-valent phase. These new metalincorporated phases are catalytically active and the palladium incorporated compound in particular displays shape selective catalysis for different oxidation and reduction reactions. In another approach, the preparation of VOHPO4$\\cdot$0.5H2O has been modified to give a novel crystalline phase containing mixed-valent vanadium and having NH3 species bound to the lattice. This phase could be a potential catalyst for ammoxidation reactions. In addition, novel mesostructured vanadium phosphate phases have been prepared using a long-chain amine as the templating agent involving a ligand templating mechanism of formation.

  8. Mineral phosphate solubilizing bacterial community in agro-ecosystem

    African Journals Online (AJOL)

    STORAGESEVER

    2009-12-15

    Dec 15, 2009 ... patterns. Four insoluble phosphate sources; purulia rock phosphate (PRP), mussourie rock phosphate .... phosphate in gradient soils, there might be changes in ..... resistance properties, fatty acid profiling and nucleic acid.

  9. Calcium phosphate cements: study of the beta-tricalcium phosphate--monocalcium phosphate system.

    Science.gov (United States)

    Mirtchi, A A; Lemaitre, J; Terao, N

    1989-09-01

    The possibility of making cements based on beta-tricalcium phosphate (beta-TCP), a promising bone graft material, was investigated. Upon admixture with water, beta-TCP/monocalcium phosphate monohydrate (MCPM) mixtures were found to set and harden like conventional hydraulic cements. Beta-TCP powders with larger particle size, obtained by sintering at higher temperatures, increased the ultimate strength of the cement. Results show that setting occurs after dissolution of MCPM, as a result of the precipitation of dicalcium phosphate dihydrate (DCPD) in the paste. The ultimate tensile strength of the hardened cement is proportional to the amount of DCPD formed. Upon ageing above 40 degrees C, DCPD transforms progressively into anhydrous dicalcium phosphate (DCP), thereby decreasing the strength. Ageing of the pastes in 100% r.h. results in a decay of the mechanical properties. This can be ascribed to an intergranular dissolution of the beta-TCP aggregates as a result of the pH lowering brought about by the MCPM to DCPD conversion.

  10. Hydrogen sulphide.

    Science.gov (United States)

    Guidotti, T L

    1996-10-01

    Hydrogen sulphide (H2S) is the primary chemical hazard in natural gas production in 'sour' gas fields. It is also a hazard in sewage treatment and manure-containment operations, construction in wetlands, pelt processing, certain types of pulp and paper production, and any situation in which organic material decays or inorganic sulphides exist under reducing conditions. H2S dissociates into free sulphide in the circulation. Sulphide binds to many macromolecules, among them cytochrome oxidase. Although this is undoubtedly an important mechanism of toxicity due to H2S, there may be others H2S provides little opportunity for escape at high concentrations because of the olfactory paralysis it causes, the steep exposure-response relationships, and the characteristically sudden loss of consciousness it can cause which is colloquially termed 'knockdown.' Other effects may include mucosal irritation, which is associated at lower concentrations with a keratoconjunctivitis called 'gas eye' and at higher concentrations with risk of pulmonary oedema. Chronic central nervous system sequelae may possibly follow repeated knockdowns: this is controversial and the primary effects of H2S may be confounded by anoxia or head trauma. Treatment is currently empirical, with a combination of nitrite and hyperbaric oxygen preferred. The treatment regimen is not ideal and carries some risk.

  11. A hydrogen ice cube

    NARCIS (Netherlands)

    Schrauwers, A.

    2004-01-01

    Hydrogen is considered to be a highly promising energy carrier. Nonetheless, before hydrogen can become the fuel of choice for the future a number of slight problems will have to be overcome. For example, how can hydrogen be safely stored? Motor vehicles running on hydrogen may be clean in concept

  12. A hydrogen ice cube

    NARCIS (Netherlands)

    Schrauwers, A.

    2004-01-01

    Hydrogen is considered to be a highly promising energy carrier. Nonetheless, before hydrogen can become the fuel of choice for the future a number of slight problems will have to be overcome. For example, how can hydrogen be safely stored? Motor vehicles running on hydrogen may be clean in concept b

  13. [Phosphate sensing and parathyroid gland].

    Science.gov (United States)

    Mizobuchi, Masahide; Suzuki, Taihei

    2012-10-01

    In the latter 1990s, phosphate, as well as calcium, has been shown to have a direct action on parathyroid function. Since then although many researchers have tried to detect the phosphate sensor in parathyroid gland, none has found it yet. In 2000s, the importance of FGF23 was revealed in patients with autosomal dominant hypophosphatemic rickets and then investigating the role of FGF23 in mineral metabolism has spread. FGF23 target organs comprise those that express coreceptor Klotho, such as kidney and parathyroid glands. While associations of calcium sensing receptor or vitamin D receptor with parathyroid function have been mainly investigated for parathyroid dysfunction, many efforts recently have made to study the effects of FGF23 on parathyroid glands.

  14. Calcium phosphate polymer hybrid materials

    OpenAIRE

    2011-01-01

    Calcium phosphate (CaP) is of strong interest to the medical field because of its potential for bone repair, gene transfection, etc.1-3 Nowadays, the majority of the commercially available materials are fabricated via “classical” materials science approaches, i.e. via high temperature or high pressure approaches, from rather poorly defined slurries, or from organic solvents.3,4 Precipitation of inorganics with (polymeric) additives from aqueous solution on the other hand enables the synthesis...

  15. Effects of phosphates on microstructure and bioactivity of micro-arc oxidized calcium phosphate coatings on Mg-Zn-Zr magnesium alloy.

    Science.gov (United States)

    Pan, Y K; Chen, C Z; Wang, D G; Zhao, T G

    2013-09-01

    Calcium phosphate (CaP) coatings were prepared on Mg-Zn-Zr magnesium alloy by micro-arc oxidation (MAO) in electrolyte containing calcium acetate monohydrate (CH3COO)2Ca·H2O) and different phosphates (i.e. disodium hydrogen phosphate dodecahydrate (Na2HPO4·12H2O), sodium phosphate (Na3PO4·H2O) and sodium hexametaphosphate((NaPO3)6)). Scanning electron microscope (SEM), energy-dispersive X-ray spectrometry (EDS) and X-ray diffractometer (XRD) were employed to characterize the microstructure, elemental distribution and phase composition of the CaP coatings. Simulated body fluid (SBF) immersion test was used to evaluate the coating bioactivity and degradability. Systemic toxicity test was used to evaluate the coating biocompatibility. Fluoride ion selective electrode (ISE) was used to measure F(-) ions concentration during 30 days SBF immersion. The CaP coatings effectively reduced the corrosion rate and the surfaces of CaP coatings were covered by a new layer formed of numerous needle-like and scale-like apatites. The formation of these calcium phosphate apatites indicates that the coatings have excellent bioactivity. The coatings formed in (NaPO3)6-containging electrolyte exhibit thicker thickness, higher adhesive strength, slower degradation rate, better apatite-inducing ability and biocompatibility. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Hydrogen isotope geochemistry of lherzolitic shergottite in Martian meteorite GRV99027 from the Grove Mountains in Antarctica

    Institute of Scientific and Technical Information of China (English)

    WANG Henan; HSU Weibiao; GUAN Yunbin; LIANG Ying

    2006-01-01

    Hydrogen isotopic composition was measured using an ion microprobe for lherzolitic shergottite in Martian meteorite GRV 99027 from the Grove Mountains in Antarctica. The D/H ratios of phosphate whitlockites were analyzed and water concentrations of tested points were calculated. The result show that their δD values vary from +1300‰ to +4700‰, and water contents from 0.04 wt% to 0.43 wt%. Comparing the results with the hydrogen isotopic compositions of whole rock, hydrous minerals and phosphates in SNC meteorites indicates that water highly enriched in deuterium is a unique feature of Martian meteorites, especially the phosphates prominent. It is interpreted as the result of isotopic exchange between magmatic water and Martian crustal fluids. The high D/H ratios observed in GRV 99027 phosphates indicate that they have hydrogen isotopic compositions similar to those of apatite in other Martian meteorites. The results further confirmed the association of GRV 99027 with the Martian meteorite group.

  17. Why hydrogen; Pourquoi l'hydrogene?

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-02-01

    The energy consumption increase and the associated environmental risks, led to develop new energy sources. The authors present the potentialities of the hydrogen in this context of energy supply safety. They detail the today market and the perspectives, the energy sources for the hydrogen production (fossils, nuclear and renewable), the hydrogen transport, storage, distribution and conversion, the application domains, the associated risks. (A.L.B.)

  18. Why hydrogen; Pourquoi l'hydrogene?

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-02-01

    The energy consumption increase and the associated environmental risks, led to develop new energy sources. The authors present the potentialities of the hydrogen in this context of energy supply safety. They detail the today market and the perspectives, the energy sources for the hydrogen production (fossils, nuclear and renewable), the hydrogen transport, storage, distribution and conversion, the application domains, the associated risks. (A.L.B.)

  19. Hexa-kis-(3-chloro-2-methyl-anilinium) cyclo-hexa-phosphate dihydrate.

    Science.gov (United States)

    Bel Haj Salah, Raoudha; Khederi, Lamia; Rzaigui, Mohamed

    2014-01-01

    In the organic/inorganic salt hydrate, 6C7H9ClN(+)·P6O18 (6-)·2H2O, the cyclo-hexa-phosphate anion resides on an inversion centre. The asymmetric unit consists of three cations, one half-anion and a water mol-ecule. In the crystal, the water mol-ecules and the [P6O18](6-) anions are linked by O-H⋯O hydrogen bonds, generating infinite layers parallel to the ab plane. These layers are inter-connected by the organic cations through N-H⋯O hydrogen bonds.

  20. Water structure and dynamics in phosphate fluorosurfactant based reverse micelle: A computer simulation study

    Science.gov (United States)

    Senapati, Sanjib; Berkowitz, Max L.

    2003-01-01

    We performed a molecular dynamics simulation on a system containing a water pool inside the reverse micelle made up of an assembly of phosphate fluorosurfactant molecules dissolved in supercritical carbon dioxide. The water molecules in the first solvation shell of the headgroup lose the water to water tetrahedral hydrogen bonded network but are strongly bonded to the surfactant headgroups. This change in inter-water hydrogen bonding in connection with the confined geometry of the reverse micelle slows down the translational and especially the rotational dynamics of water.

  1. Phosphate: are we squandering a scarce commodity?

    Science.gov (United States)

    Ferro, Charles J; Ritz, Eberhard; Townend, Jonathan N

    2015-02-01

    Phosphorus is an essential element for life but is a rare element in the universe. On Earth, it occurs mostly in the form of phosphates that are widespread but predominantly at very low concentration. This relative rarity has resulted in a survival advantage, in evolutionary terms, to organisms that conserve phosphate. When phosphate is made available in excess it becomes a cause for disease, perhaps best recognized as a potential cardiovascular and renal risk factor. As a reaction to the emerging public health issue caused by phosphate additives to food items, there have been calls for a public education programme and regulation to bring about a reduction of phosphate additives to food. During the Paleoproterzoic era, an increase in the bioavailability of phosphate is thought to have contributed significantly to the oxygenation of our atmosphere and a dramatic increase in the evolution of new species. Currently, phosphate is used poorly and often wasted with phosphate fertilizers washing this scarce commodity into water bodies causing eutrophication and algal blooms. Ironically, this is leading to the extinction of hundreds of species. The unchecked exploitation of phosphate rock, which is an increasingly rare natural resource, and our dependence on it for agriculture may lead to a strange situation in which phosphate might become a commodity to be fought over whilst at the same time, health and environmental experts are likely to recommend reductions in its use.

  2. Zinc phosphate as versatile material for potential biomedical applications Part II.

    Science.gov (United States)

    Herschke, L; Lieberwirth, I; Wegner, G

    2006-01-01

    Surface chemical reactivity of two modifications of synthetic zinc phosphate tetrahydrate (alpha - and beta -form of Hopeite, alpha -,beta -ZPT) has been studied by selective chemical and e-beam etching in presence of diluted phosphoric acid and ammonia by Scanning Electron Microscopy (SEM) and microelectrophoresis (zeta potential measurements) in correlation with the corresponding bulk properties and crystal size distributions. The subtitle crystallographic differences between alpha -and beta -ZPT originating from a unique hydrogen bonding pattern, induce drastic variations of both surface potential and surface charge. Biogenic Hydroxyapatite (HAP) and one of its metastable precursors, a calcium dihydrogen phosphate dihydrate (DCPD) or Brushite were used to underline this resulting variation of chemical reactivity in zinc phosphates. In-situ monitoring of the transformation of Brushite in Hydroxyapatite is also reported.

  3. Hydrogen energy systems studies

    Energy Technology Data Exchange (ETDEWEB)

    Ogden, J.M.; Kreutz, T.G.; Steinbugler, M. [Princeton Univ., NJ (United States)] [and others

    1996-10-01

    In this report the authors describe results from technical and economic assessments carried out during the past year with support from the USDOE Hydrogen R&D Program. (1) Assessment of technologies for small scale production of hydrogen from natural gas. Because of the cost and logistics of transporting and storing hydrogen, it may be preferable to produce hydrogen at the point of use from more readily available energy carriers such as natural gas or electricity. In this task the authors assess near term technologies for producing hydrogen from natural gas at small scale including steam reforming, partial oxidation and autothermal reforming. (2) Case study of developing a hydrogen vehicle refueling infrastructure in Southern California. Many analysts suggest that the first widespread use of hydrogen energy is likely to be in zero emission vehicles in Southern California. Several hundred thousand zero emission automobiles are projected for the Los Angeles Basin alone by 2010, if mandated levels are implemented. Assuming that hydrogen vehicles capture a significant fraction of this market, a large demand for hydrogen fuel could evolve over the next few decades. Refueling a large number of hydrogen vehicles poses significant challenges. In this task the authors assess near term options for producing and delivering gaseous hydrogen transportation fuel to users in Southern California including: (1) hydrogen produced from natural gas in a large, centralized steam reforming plant, and delivered to refueling stations via liquid hydrogen truck or small scale hydrogen gas pipeline, (2) hydrogen produced at the refueling station via small scale steam reforming of natural gas, (3) hydrogen produced via small scale electrolysis at the refueling station, and (4) hydrogen from low cost chemical industry sources (e.g. excess capacity in refineries which have recently upgraded their hydrogen production capacity, etc.).

  4. Concentration of Hydrogen Peroxide

    Science.gov (United States)

    Parrish, Clyde F. (Inventor)

    2006-01-01

    Methods for concentrating hydrogen peroxide solutions have been described. The methods utilize a polymeric membrane separating a hydrogen peroxide solution from a sweep gas or permeate. The membrane is selective to the permeability of water over the permeability of hydrogen peroxide, thereby facilitating the concentration of the hydrogen peroxide solution through the transport of water through the membrane to the permeate. By utilizing methods in accordance with the invention, hydrogen peroxide solutions of up to 85% by volume or higher may be generated at a point of use without storing substantial quantities of the highly concentrated solutions and without requiring temperatures that would produce explosive mixtures of hydrogen peroxide vapors.

  5. Hydrogen in semiconductors

    CERN Document Server

    Pankove, Jacques I

    1991-01-01

    Hydrogen plays an important role in silicon technology, having a profound effect on a wide range of properties. Thus, the study of hydrogen in semiconductors has received much attention from an interdisciplinary assortment of researchers. This sixteen-chapter volume provides a comprehensive review of the field, including a discussion of hydrogenation methods, the use of hydrogen to passivate defects, the use of hydrogen to neutralize deep levels, shallow acceptors and shallow donors in silicon, vibrational spectroscopy, and hydrogen-induced defects in silicon. In addition to this detailed cove

  6. Sensing of aqueous phosphates by polymers with dual modes of signal transduction.

    Science.gov (United States)

    Aldakov, Dmitry; Anzenbacher, Pavel

    2004-04-21

    A new approach to sensing of aqueous phosphate-related anions based on chromogenic conductive polymers is demonstrated. This method utilizes synergy between low-level p-doping in a polythiophene polymer and hydrogen bonding to increase anion-sensor affinity. These chromogenic conductive polymers show anion-specific changes both in color and in conductivity upon increasing concentration of anions, thus providing two independent modes of signal transduction.

  7. Phosphate adsorption onto hematite: an in situ ATR-FTIR investigation of the effects of pH and loading level on the mode of phosphate surface complexation.

    Science.gov (United States)

    Elzinga, Evert J; Sparks, Donald L

    2007-04-01

    Phosphate adsorption on hematite was characterized as a function of pH (3.5-8.9) and phosphate concentration (5-500 microM) by in situ ATR-FTIR spectroscopy. Under most conditions a mixture of different (inner-sphere) phosphate complexes existed at the hematite surface, with the relative importance of these complexes varying with pH and surface coverage. Experiments using D(2)O and H(2)O indicated the presence of two protonated phosphate surface complexes at pH/pD=3.5-7.0. Comparison to spectra of protonated aqueous phosphate species suggested that these surface complexes are monoprotonated. The difference in the IR spectra of these complexes is tentatively interpreted to result from a different surface coordination, with one surface complex coordinated in a monodentate binuclear (bridging) fashion, and the second as a monodentate mononuclear complex. Alternatively, the bridging complex may be a (protonated) monodentate mononuclear complex exhibiting strong hydrogen bonding to an adjacent surface site, and the second species a monodentate complex exhibiting limited hydrogen bonding. Formation of the bridging complex is favored at lower pH values and higher surface loadings in the 3.5-7.0 pH range. At the highest pH values studied (8.5-9.0) a third complex, interpreted to be a nonprotonated monodentate mononuclear complex, is present along with the monodentate monoprotonated surface species. The importance of the nonprotonated monodentate complex increases with increasing surface coverage at these high pH values.

  8. Molecular basis of reduced pyridoxine 5'-phosphate oxidase catalytic activity in neonatal epileptic encephalopathy disorder.

    Science.gov (United States)

    Musayev, Faik N; Di Salvo, Martino L; Saavedra, Mario A; Contestabile, Roberto; Ghatge, Mohini S; Haynes, Alexina; Schirch, Verne; Safo, Martin K

    2009-11-06

    Mutations in pyridoxine 5'-phosphate oxidase are known to cause neonatal epileptic encephalopathy. This disorder has no cure or effective treatment and is often fatal. Pyridoxine 5'-phosphate oxidase catalyzes the oxidation of pyridoxine 5'-phosphate to pyridoxal 5'-phosphate, the active cofactor form of vitamin B(6) required by more than 140 different catalytic activities, including enzymes involved in amino acid metabolism and biosynthesis of neurotransmitters. Our aim is to elucidate the mechanism by which a homozygous missense mutation (R229W) in the oxidase, linked to neonatal epileptic encephalopathy, leads to reduced oxidase activity. The R229W variant is approximately 850-fold less efficient than the wild-type enzyme due to an approximately 192-fold decrease in pyridoxine 5'-phosphate affinity and an approximately 4.5-fold decrease in catalytic activity. There is also an approximately 50-fold reduction in the affinity of the R229W variant for the FMN cofactor. A 2.5 A crystal structure of the R229W variant shows that the substitution of Arg-229 at the FMN binding site has led to a loss of hydrogen-bond and/or salt-bridge interactions between FMN and Arg-229 and Ser-175. Additionally, the mutation has led to an alteration of the configuration of a beta-strand-loop-beta-strand structure at the active site, resulting in loss of two critical hydrogen-bond interactions involving residues His-227 and Arg-225, which are important for substrate binding and orientation for catalysis. These results provide a molecular basis for the phenotype associated with the R229W mutation, as well as providing a foundation for understanding the pathophysiological consequences of pyridoxine 5'-phosphate oxidase mutations.

  9. Calcium phosphate coating on magnesium alloy by biomimetic method :Investigation of morphology ,composition and formation process

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Magnesium alloy has similar mechanical properties with natural bone and can degrade via corrosion in the electrolytic environment of the human body.Calcium phosphate has been proven to possess bioactivity and bone inductivity.In order to integrate both advantages,calcium phosphate coating was fabricated on magnesium alloy by a biomimetic method.Supersaturated calcification solutions (SCSs) with different Ca/P ratio and C1- concentration were used as mimetic solutions.The morphology,composition and formation process of the coating were studied with scanning electron microscopy (SEM),energy dispersive spectrometer (EDS),Fourier transformed infrared spectroscopy (FTIR) and X-ray diffraction (XRD).The results show that a uniform calcium phosphate coating was observed on magnesium alloy,the properties of which could be adjusted by the SCSs with different Ca/P ratio.The formation process of the coating was explored by immersing magnesium alloy in SCSs with different Cl- concentration which could adjust the hydrogen production.According to SEM results,the hydrogen bubbles were associated with the formation of grass-like and flower-like coating morphologies.In conclusion,the biomimetic method was effective to form calcium phosphate coating on magnesium alloy and the morphology and composition of the coating could be accommodated by the Ca/P ratio and Cl- concentration in SCSs.

  10. Can Phosphate Salts Recovered from Manure Replace Conventional Phosphate Fertilizer?

    Directory of Open Access Journals (Sweden)

    Andrea Ehmann

    2017-01-01

    Full Text Available Pig farming produces more manure than can reasonably be spread onto surrounding fields, particularly in regions with high livestock densities and limited land availability. Nutrient recycling offers an attractive solution for dealing with manure excesses and is one main objective of the European commission-funded project “BioEcoSIM”. Phosphate salts (“P-Salt” were recovered from the separated liquid manure fraction. The solid fraction was dried and carbonized to biochar. This study compared the fertilizing performance of P-Salt and conventional phosphate fertilizer and determined whether additional biochar application further increased biomass yields. The fertilizers and biochar were tested in pot experiments with spring barley and faba beans using two nutrient-poor soils. The crops were fertilized with P-Salt at three levels and biochar in two concentrations. Biomass yield was determined after six weeks. Plant and soil samples were analysed for nitrogen, phosphorus and potassium contents. The P-Salt had similar or even better effects than mineral fertilizer on growth in both crops and soils. Slow release of nutrients can prevent leaching, rendering P-Salt a particularly suitable fertilizer for light sandy soils. Biochar can enhance its fertilizing effect, but the underlying mechanisms need further investigation. These novel products are concluded to be promising candidates for efficient fertilization strategies.

  11. Tetracalcium phosphate: Synthesis, properties and biomedical applications.

    Science.gov (United States)

    Moseke, C; Gbureck, U

    2010-10-01

    Monoclinic tetracalcium phosphate (TTCP, Ca(4)(PO(4))(2)O), also known by the mineral name hilgenstockite, is formed in the (CaO-P(2)O(5)) system at temperatures>1300 degrees C. TTCP is the only calcium phosphate with a Ca/P ratio greater than hydroxyapatite (HA). It appears as a by-product in plasma-sprayed HA coatings and shows moderate reactivity and concurrent solubility when combined with acidic calcium phosphates such as dicalcium phosphate anhydrous (DCPA, monetite) or dicalcium phosphate dihydrate (DCPD, brushite). Therefore it is widely used in self-setting calcium phosphate bone cements, which form HA under physiological conditions. This paper aims to review the synthesis and properties of TTCP in biomaterials applications such as cements, sintered ceramics and coatings on implant metals.

  12. Insight into biological phosphate recovery from sewage.

    Science.gov (United States)

    Ye, Yuanyao; Ngo, Huu Hao; Guo, Wenshan; Liu, Yiwen; Zhang, Xinbo; Guo, Jianbo; Ni, Bing-Jie; Chang, Soon Woong; Nguyen, Dinh Duc

    2016-10-01

    The world's increasing population means that more food production is required. A more sustainable supply of fertilizers mainly consisting of phosphate is needed. Due to the rising consumption of scarce resources and limited natural supply of phosphate, the recovery of phosphate and their re-use has potentially high market value. Sewage has high potential to recover a large amount of phosphate in a circular economy approach. This paper focuses on utilization of biological process integrated with various subsequent processes to concentrate and recycle phosphate which are derived from liquid and sludge phases. The phosphate accumulation and recovery are discussed in terms of mechanism and governing parameters, recovery efficiency, application at plant-scale and economy.

  13. Application of Calcium Phosphate Materials in Dentistry

    Directory of Open Access Journals (Sweden)

    Jabr S. Al-Sanabani

    2013-01-01

    Full Text Available Calcium phosphate materials are similar to bone in composition and in having bioactive and osteoconductive properties. Calcium phosphate materials in different forms, as cements, composites, and coatings, are used in many medical and dental applications. This paper reviews the applications of these materials in dentistry. It presents a brief history, dental applications, and methods for improving their mechanical properties. Notable research is highlighted regarding (1 application of calcium phosphate into various fields in dentistry; (2 improving mechanical properties of calcium phosphate; (3 biomimetic process and functionally graded materials. This paper deals with most common types of the calcium phosphate materials such as hydroxyapatite and tricalcium phosphate which are currently used in dental and medical fields.

  14. Vibrational spectroscopic study of the phosphate mineral kryzhanovskite and in comparison with reddingite-implications for the molecular structure

    Science.gov (United States)

    Frost, Ray L.; Scholz, Ricardo; Wang, Lina

    2016-08-01

    We have studied the phosphate mineral kryzhanovskite (Fe3+,Mn2+)3(PO4)2(OH,H2O) which is a member of the phosphoferrite mineral group using a combination of scanning electron microscopy with energy dispersive spectroscopy and Raman and infrared spectroscopy. Chemical analysis shows the presence of P, Mn and Fe and confirms the formula given above. The presence of hydroxyl units in the structure is indicative of ferric iron in the formula that is an oxidised product. Raman spectroscopy coupled with infrared spectroscopy supports the concept of phosphate, hydrogen phosphate and dihydrogen phosphate units in the structure of kryzhanovskite -phosphoferrite. Infrared and Raman bands attributed to water and hydroxyl stretching modes are identified. Vibrational spectroscopy adds useful information to the molecular structure of kryzhanovskite -phosphoferrite.

  15. Matrix Extracellular Phosphoglycoprotein Inhibits Phosphate Transport

    OpenAIRE

    Marks, J; Churchill, L J; Debnam, E. S.; Unwin, R J

    2008-01-01

    The role of putative humoral factors, known as phosphatonins, in phosphate homeostasis and the relationship between phosphate handling by the kidney and gastrointestinal tract are incompletely understood. Matrix extracellular phosphoglycoprotein (MEPE), one of several candidate phosphatonins, promotes phosphaturia, but whether it also affects intestinal phosphate absorption is unknown. Here, using the in situ intestinal loop technique, we demonstrated that short-term infusion of MEPE inhibits...

  16. Crystal structure and substrate specificity of D-galactose-6-phosphate isomerase complexed with substrates.

    Directory of Open Access Journals (Sweden)

    Woo-Suk Jung

    Full Text Available D-Galactose-6-phosphate isomerase from Lactobacillus rhamnosus (LacAB; EC 5.3.1.26, which is encoded by the tagatose-6-phosphate pathway gene cluster (lacABCD, catalyzes the isomerization of D-galactose-6-phosphate to D-tagatose-6-phosphate during lactose catabolism and is used to produce rare sugars as low-calorie natural sweeteners. The crystal structures of LacAB and its complex with D-tagatose-6-phosphate revealed that LacAB is a homotetramer of LacA and LacB subunits, with a structure similar to that of ribose-5-phosphate isomerase (Rpi. Structurally, LacAB belongs to the RpiB/LacAB superfamily, having a Rossmann-like αβα sandwich fold as has been identified in pentose phosphate isomerase and hexose phosphate isomerase. In contrast to other family members, the LacB subunit also has a unique α7 helix in its C-terminus. One active site is distinctly located at the interface between LacA and LacB, whereas two active sites are present in RpiB. In the structure of the product complex, the phosphate group of D-tagatose-6-phosphate is bound to three arginine residues, including Arg-39, producing a different substrate orientation than that in RpiB, where the substrate binds at Asp-43. Due to the proximity of the Arg-134 residue and backbone Cα of the α6 helix in LacA to the last Asp-172 residue of LacB with a hydrogen bond, a six-carbon sugar-phosphate can bind in the larger pocket of LacAB, compared with RpiB. His-96 in the active site is important for ring opening and substrate orientation, and Cys-65 is essential for the isomerization activity of the enzyme. Two rare sugar substrates, D-psicose and D-ribulose, show optimal binding in the LacAB-substrate complex. These findings were supported by the results of LacA activity assays.

  17. Distrontium trimanganese(II) bis-(hydro-gen-phosphate) bis-(ortho-phosphate).

    Science.gov (United States)

    Khmiyas, Jamal; Assani, Abderrazzak; Saadi, Mohamed; El Ammari, Lahcen

    2013-01-01

    The title compound, Sr2Mn3(HPO4)2(PO4)2, was synthesized under hydro-thermal conditions. In the structure, one of two Mn atoms is located on an inversion centre, whereas all others atoms are located in general positions. The framework structure is built up from two types of MnO6 octa-hedra (one almost undistorted, one considerably distorted), one PO3OH and one PO4 tetra-hedron. The centrosymmetric MnO6 octa-hedron is linked to two other MnO6 octa-hedra by edge-sharing, forming infinite zigzag chains parallel to [010]. The PO3OH and PO4 tetra-hedra connect these chains through common vertices or edges, resulting in the formation of sheets parallel to (100). The Sr(2+) cation is located in the inter-layer space and is bonded to nine O atoms in form of a distorted polyhedron and enhances the cohesion of the layers. Additional stabilization is achieved by a strong inter-layer O-H⋯O hydrogen bond between the PO3OH and PO4 units. The structure of the title phosphate is isotypic to that of Pb2Mn3(HPO4)2(PO4)2.

  18. Crystal structure of hydrazine iron(III) phosphate, the first transition metal phosphate containing hydrazine.

    Science.gov (United States)

    David, Renald

    2015-12-01

    The title compound, poly[(μ2-hydrazine)(μ4-phosphato)iron(III)], [Fe(PO4)(N2H4)] n , was prepared under hydro-thermal conditions. Its asymmetric unit contains one Fe(III) atom located on an inversion centre, one P atom located on a twofold rotation axis, and two O, one N and two H atoms located on general positions. The Fe(III) atom is bound to four O atoms of symmetry-related PO4 tetra-hedra and to two N atoms of two symmetry-related hydrazine ligands, resulting in a slightly distorted FeO4N2 octa-hedron. The crystal structure consists of a three-dimensional hydrazine/iron phoshate framework whereby each PO4 tetra-hedron bridges four Fe(III) atoms and each hydrazine ligand bridges two Fe(III) atoms. The H atoms of the hydrazine ligands are also involved in moderate N-H⋯O hydrogen bonding with phosphate O atoms. The crystal structure is isotypic with the sulfates [Co(SO4)(N2H4)] and [Mn(SO4)(N2H4)].

  19. Crystal structure of hydrazine iron(III phosphate, the first transition metal phosphate containing hydrazine

    Directory of Open Access Journals (Sweden)

    Renald David

    2015-12-01

    Full Text Available The title compound, poly[(μ2-hydrazine(μ4-phosphatoiron(III], [Fe(PO4(N2H4]n, was prepared under hydrothermal conditions. Its asymmetric unit contains one FeIII atom located on an inversion centre, one P atom located on a twofold rotation axis, and two O, one N and two H atoms located on general positions. The FeIII atom is bound to four O atoms of symmetry-related PO4 tetrahedra and to two N atoms of two symmetry-related hydrazine ligands, resulting in a slightly distorted FeO4N2 octahedron. The crystal structure consists of a three-dimensional hydrazine/iron phoshate framework whereby each PO4 tetrahedron bridges four FeIII atoms and each hydrazine ligand bridges two FeIII atoms. The H atoms of the hydrazine ligands are also involved in moderate N—H...O hydrogen bonding with phosphate O atoms. The crystal structure is isotypic with the sulfates [Co(SO4(N2H4] and [Mn(SO4(N2H4].

  20. Dynamics of hydrogen in hydrogenated amorphous silicon

    Indian Academy of Sciences (India)

    Ranber Singh; S Prakash

    2003-07-01

    The problem of hydrogen diffusion in hydrogenated amorphous silicon (a-Si:H) is studied semiclassically. It is found that the local hydrogen concentration fluctuations-induced extra potential wells, if intense enough, lead to the localized electronic states in a-Si:H. These localized states are metastable. The trapping of electrons and holes in these states leads to the electrical degradation of the material. These states also act as recombination centers for photo-generated carriers (electrons and holes) which in turn may excite a hydrogen atom from a nearby Si–H bond and breaks the weak (strained) Si–Si bond thereby apparently enhancing the hydrogen diffusion and increasing the light-induced dangling bonds.

  1. Hydrogen transport membranes

    Science.gov (United States)

    Mundschau, Michael V.

    2005-05-31

    Composite hydrogen transport membranes, which are used for extraction of hydrogen from gas mixtures are provided. Methods are described for supporting metals and metal alloys which have high hydrogen permeability, but which are either too thin to be self supporting, too weak to resist differential pressures across the membrane, or which become embrittled by hydrogen. Support materials are chosen to be lattice matched to the metals and metal alloys. Preferred metals with high permeability for hydrogen include vanadium, niobium, tantalum, zirconium, palladium, and alloys thereof. Hydrogen-permeable membranes include those in which the pores of a porous support matrix are blocked by hydrogen-permeable metals and metal alloys, those in which the pores of a porous metal matrix are blocked with materials which make the membrane impervious to gases other than hydrogen, and cermets fabricated by sintering powders of metals with powders of lattice-matched ceramic.

  2. Hydrogen production by Cyanobacteria

    Directory of Open Access Journals (Sweden)

    Chaudhuri Surabhi

    2005-12-01

    Full Text Available Abstract The limited fossil fuel prompts the prospecting of various unconventional energy sources to take over the traditional fossil fuel energy source. In this respect the use of hydrogen gas is an attractive alternate source. Attributed by its numerous advantages including those of environmentally clean, efficiency and renew ability, hydrogen gas is considered to be one of the most desired alternate. Cyanobacteria are highly promising microorganism for hydrogen production. In comparison to the traditional ways of hydrogen production (chemical, photoelectrical, Cyanobacterial hydrogen production is commercially viable. This review highlights the basic biology of cynobacterial hydrogen production, strains involved, large-scale hydrogen production and its future prospects. While integrating the existing knowledge and technology, much future improvement and progress is to be done before hydrogen is accepted as a commercial primary energy source.

  3. Handbook of hydrogen energy

    CERN Document Server

    Sherif, SA; Stefanakos, EK; Steinfeld, Aldo

    2014-01-01

    ""This book provides an excellent overview of the hydrogen economy and a thorough and comprehensive presentation of hydrogen production and storage methods.""-Scott E. Grasman, Rochester Institute of Technology, New York, USA

  4. Preparation of porous lanthanum phosphate with templates

    Energy Technology Data Exchange (ETDEWEB)

    Onoda, Hiroaki, E-mail: onoda@kpu.ac.jp [Department of Informatics and Environmental Sciences, Faculty of Life and Environmental Sciences, Kyoto Prefectural University, 1-5, Shimogamo Nakaragi-cyo, Sakyo-ku, Kyoto 606-8522 (Japan); Ishima, Yuya [Department of Applied Chemistry, Faculty of Life Sciences, Ritsumeikan University, 1-1-1, Nojihigashi, Kusatsu, Shiga 525-8577 (Japan); Takenaka, Atsushi [Department of Materials Science, Yonago National College of Technology, 4448, Hikona-cho, Yonago, Tottori 683-8502 (Japan); Tanaka, Isao [Department of Materials Science and Engineering, Faculty of Engineering, Kyoto University, Yoshida-Honmachi, Sakyo-ku, Kyoto 606-8501 (Japan)

    2009-08-05

    Malonic acid, propionic acid, glycine, n-butylamine, and urea were added to the preparation of lanthanum phosphate from lanthanum nitrate and phosphoric acid solutions. All additives were taken into lanthanum phosphate particles. The additives that have a basic site were easy to contain in precipitates. The addition of templates improved the specific surface area of lanthanum phosphate. The amount of pore, with radius smaller than 4 nm, increased with the addition of templates. The remained additives had influence on the acidic properties of lanthanum phosphate.

  5. Mineral induced formation of sugar phosphates

    Science.gov (United States)

    Pitsch, S.; Eschenmoser, A.; Gedulin, B.; Hui, S.; Arrhenius, G.

    1995-01-01

    Glycolaldehyde phosphate, sorbed from highly dilute, weakly alkaline solution into the interlayer of common expanding sheet structure metal hydroxide minerals, condenses extensively to racemic aldotetrose-2, 4-diphophates, and aldohexose-2, 4, 6-triphosphates. The reaction proceeds mainly through racemic erythrose-2, 4-phosphate, and terminates with a large fraction of racemic altrose-2, 4, 6-phosphate. In the absence of an inductive mineral phase, no detectable homogeneous reaction takes place in the concentration- and pH range used. The reactant glycolaldehyde phosphate is practically completely sorbed within an hour from solutions with concentrations as low as 50 micron; the half-time for conversion to hexose phosphates is of the order of two days at room temperature and pH 9.5. Total production of sugar phosphates in the mineral interlayer is largely independent of the glycolaldehyde phosphate concentration in the external solution, but is determined by the total amount of GAP offered for sorption up to the capacity of the mineral. In the presence of equimolar amounts of rac-glyceraldehyde-2-phosphate, but under otherwise similar conditions, aldopentose-2, 4, -diphosphates also form, but only as a small fraction of the hexose-2, 4, 6-phosphates.

  6. Study of Viability of Phosphate Solubilizing Bacteria in Phosphate granules

    Directory of Open Access Journals (Sweden)

    hajar rajabi

    2017-06-01

    Full Text Available Introduction: sustainable development and the environment are interconnected. Sustainable agriculture is continuous utilization of a farm with respect to various aspects of environmental conditions by using fewer inputs (other than Bio-fertilizers. Phosphorus is one of the essential elements for the plants. Management of soil is possible by using biological fertilizers pillar of sustainable agriculture and providing some of the phosphorus needed by plants via bio-fertilizers. Phosphorus deficiency is extremely effective on the plant growth and productivity. The application of phosphorus fertilizers is expensive and dangerous. In addition, phosphorus in the soilmay become insoluble and will be unavailable to the plants. Studies showed that phosphate solubilizing bacteria in the soil rhizosphere are active and by root exudates solve insoluble phosphates such as tricalcium phosphate, and form absorbable P for plant. Consequently, the use of microbial fertilizers could reduce excessive use of chemical fertilizers and lead to decrease their harmful effects and protect the environment and conservation of available resources. The biological phosphate fertilizer industry uses sugar beet molasses as a binder and drying granules at high temperatures. Therefore, it is important to evaluate the durability of the bacteria in molasses at high temperature. Materials and Methods: This study was designed as completely randomized design in a factorial arrangement.10 isolates were selected and the ratios of 50%, 25%, 15% and 10% of the apatite, organic matter, sulfur and soluble granule (ratio 1: 1 and 2: 1 bacteria and molasses, respectively, for each isolate was prepared. The final product was dried at 28 and 40 °C and remained for 4 months and population counted at first day and 10, 20, 30, 60, 90 and 120 days after the preparing. The population was counted by the serial dilution technique and cultured at Sperber media. Results and Discussion:Comparing the

  7. Hydrogen Technologies Safety Guide

    Energy Technology Data Exchange (ETDEWEB)

    Rivkin, C. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Burgess, R. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Buttner, W. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-01-01

    The purpose of this guide is to provide basic background information on hydrogen technologies. It is intended to provide project developers, code officials, and other interested parties the background information to be able to put hydrogen safety in context. For example, code officials reviewing permit applications for hydrogen projects will get an understanding of the industrial history of hydrogen, basic safety concerns, and safety requirements.

  8. Phosphate-binding protein from Polaromonas JS666: purification, characterization, crystallization and sulfur SAD phasing

    Energy Technology Data Exchange (ETDEWEB)

    Pegos, Vanessa R.; Hey, Louis; LaMirande, Jacob; Pfeffer, Rachel; Lipsh, Rosalie; Amitay, Moshe; Gonzalez, Daniel; Elias, Mikael (JCT-Israel); (UMM); (CNRS-UMR)

    2017-05-25

    Phosphate-binding proteins (PBPs) are key proteins that belong to the bacterial ABC-type phosphate transporters. PBPs are periplasmic (or membrane-anchored) proteins that capture phosphate anions from the environment and release them to the transmembrane transporter. Recent work has suggested that PBPs have evolved for high affinity as well as high selectivity. In particular, a short, unique hydrogen bond between the phosphate anion and an aspartate residue has been shown to be critical for selectivity, yet is not strictly conserved in PBPs. Here, the PBP fromPolaromonasJS666 is focused on. Interestingly, this PBP is predicted to harbor different phosphate-binding residues to currently known PBPs. Here, it is shown that the PBP fromPolaromonasJS666 is capable of binding phosphate, with a maximal binding activity at pH 8. Its structure is expected to reveal its binding-cleft configuration as well as its phosphate-binding mode. Here, the expression, purification, characterization, crystallization and X-ray diffraction data collection to 1.35 Å resolution of the PBP fromPolaromonasJS666 are reported.

  9. Effects of phosphate addition on methane fermentation in the batch and upflow anaerobic sludge blanket (UASB) reactors.

    Science.gov (United States)

    Suzuki, Sho; Shintani, Masaki; Sanchez, Zoe Kuizon; Kimura, Kohei; Numata, Mitsuru; Yamazoe, Atsushi; Kimbara, Kazuhide

    2015-12-01

    Ammonia inhibition of methane fermentation is one of the leading causes of failure of anaerobic digestion reactors. In a batch anaerobic digestion reactor with 429 mM NH3-N/L of ammonia, the addition of 25 mM phosphate resulted in an increase in methane production rate. Similar results were obtained with the addition of disodium phosphate in continuous anaerobic digestion using an upflow anaerobic sludge blanket (UASB) reactor. While methane content and production rate decreased in the presence of more than 143 mM NH3-N/L of ammonium chloride in UASB, the addition of 5 mM disodium phosphate suppressed ammonia inhibition at 214 mM NH3-N/L of ammonium chloride. The addition prevented acetate/propionate accumulation, which might be one of the effects of the phosphate on the ammonia inhibition. The effects on the microbial community in the UASB reactor was also assessed, which was composed of Bacteria involved in hydrolysis, acidogenesis, acetogenesis, and dehydrogenation, as well as Archaea carrying out methanogenesis. The change in the microbial community was observed by ammonia inhibition and the addition of phosphate. The change indicates that the suppression of ammonia inhibition by disodium phosphate addition could stimulate the activity of methanogens, reduce shift in bacterial community, and enhance hydrogen-producing bacteria. The addition of phosphate will be an important treatment for future studies of methane fermentation.

  10. Magnesium for Hydrogen Storage

    DEFF Research Database (Denmark)

    Vigeholm, B.; Kjøller, John; Larsen, Bent

    1980-01-01

    The reaction of hydrogen with commercially pure magnesium powder (above 99.7%) was investigated in the temperature range 250–400 °C. Hydrogen is readily sorbed above the dissociation pressure. During the initial exposure the magnesium powder sorbs hydrogen slowly below 400 °C but during the second...

  11. Biological hydrogen photoproduction

    Energy Technology Data Exchange (ETDEWEB)

    Nemoto, Y. [Univ. of Miami, FL (United States)

    1995-09-01

    Following are the major accomplishments of the 6th year`s study of biological hydrogen photoproduction which were supported by DOE/NREL. (1) We have been characterizing a biological hydrogen production system using synchronously growing aerobically nitrogen-fixing unicellular cyanobacterium, Synechococcus sp. Miami BG 043511. So far it was necessary to irradiate the cells to produce hydrogen. Under darkness they did not produce hydrogen. However, we found that, if the cells are incubated with oxygen, they produce hydrogen under the dark. Under 80% argon + 20% oxygen condition, the hydrogen production activity under the dark was about one third of that under the light + argon condition. (2) Also it was necessary so far to incubate the cells under argon atmosphere to produce hydrogen in this system. Argon treatment is very expensive and should be avoided in an actual hydrogen production system. We found that, if the cells are incubated at a high cell density and in a container with minimum headspace, it is not necessary to use argon for the hydrogen production. (3) Calcium ion was found to play an important role in the mechanisms of protection of nitrogenase from external oxygen. This will be a clue to understand the reason why the hydrogen production is so resistant to oxygen in this strain. (4) In this strain, sulfide can be used as electron donor for the hydrogen production. This result shows that waste water can be used for the hydrogen production system using this strain.

  12. Sensitive hydrogen leak detector

    Science.gov (United States)

    Myneni, Ganapati Rao

    1999-01-01

    A sensitive hydrogen leak detector system using passivation of a stainless steel vacuum chamber for low hydrogen outgassing, a high compression ratio vacuum system, a getter operating at 77.5 K and a residual gas analyzer as a quantitative hydrogen sensor.

  13. Carbonated ferric green rust as a new material for efficient phosphate removal.

    Science.gov (United States)

    Barthélémy, K; Naille, S; Despas, C; Ruby, C; Mallet, M

    2012-10-15

    Phosphate uptake from aqueous solutions by a recently discovered ferric oxyhydroxide is investigated. Carbonated ferric green rust {GR(CO(3)(2-))*} is prepared by varying two synthesis parameters, which are (1) the aging period after the ferrous-ferric green rust {GR(CO(3)(2-))} synthesis step and (2) the rate of the hydrogen peroxide addition to oxidize GR(CO(3)(2-)) into GR(CO(3)(2-))*. These two parameters permit the control of the size, morphology and cristallinity of the synthesized particles. As prepared GR* samples are then evaluated, in batch experiments, as possible low-cost efficient phosphate removal materials. Firstly, kinetic experiments reveal that a fast sorption step initially occurs and equilibrium is reached at ~500 min. The adsorption kinetics data at pH=7 can be adequately fitted to a pseudo-second order model. Secondly, the Freundlich model provides the best correlation and effectively describes phosphate sorption isotherms for all GR(CO(3)(2-))* samples synthesized. Finally, the phosphate adsorption capacity decreases when pH increases. The highest adsorption capacity is 64.8 mg g(-1) at pH=4 and corresponds to the GR(CO(3)(2-))* sample displaying the smallest and least crystallized particles thus reflecting the importance of the synthesis conditions. Overall, all sorption capacities are higher than the main iron oxide minerals, making GR(CO(3)(2-))* a potentially attractive phosphate adsorbent.

  14. On the Pressure-Induced Loss of Crystallinity in Zinc- and Calcium-Phosphates

    Energy Technology Data Exchange (ETDEWEB)

    Shakhvorostov, D.; Mosey, N; Munoz-Paniagua, D; Pereira, G; Song, Y; Kasrai, M; Norton, P; Müser, M

    2008-01-01

    A recently suggested mechanism for the stress memory of various metal phosphates is investigated experimentally. Based on first-principles simulations [N. J. Mosey et al., Science 307, 1612 (2005)], it had been argued that atoms with flexible coordination, such as zinc or heavy-metal cations, act as network-forming agents, undergoing irreversible pressure-induced changes in bonding that lead to increased connectivity between phosphate anions. In the present study, orthophosphates of zinc and calcium were exposed to high pressures on surfaces and in diamond anvil cells. An additional set of first-principles simulations was accomplished on ?-orthophosphate of zinc, which suggested that this material was already cross-linked before compression but that it nevertheless underwent a reversible coordination change under pressure in agreement with the experimental results presented here. Raman spectra indicate an irreversible, pressure-induced loss of long-range crystallinity. The pressures required to induce these changes are around 7 GPa for the zinc phosphates, while they are close to 21 GPa for the calcium phosphates. Hydrogenation of the metal phosphate lowers the threshold pressure by approximately 2-3 GPa in both cases. Moreover, ?-orthophosphate of zinc could be partially amorphisized under nonisotropic pressure on copper foils.

  15. Hydrogen separation process

    Science.gov (United States)

    Mundschau, Michael [Longmont, CO; Xie, Xiaobing [Foster City, CA; Evenson, IV, Carl; Grimmer, Paul [Longmont, CO; Wright, Harold [Longmont, CO

    2011-05-24

    A method for separating a hydrogen-rich product stream from a feed stream comprising hydrogen and at least one carbon-containing gas, comprising feeding the feed stream, at an inlet pressure greater than atmospheric pressure and a temperature greater than 200.degree. C., to a hydrogen separation membrane system comprising a membrane that is selectively permeable to hydrogen, and producing a hydrogen-rich permeate product stream on the permeate side of the membrane and a carbon dioxide-rich product raffinate stream on the raffinate side of the membrane. A method for separating a hydrogen-rich product stream from a feed stream comprising hydrogen and at least one carbon-containing gas, comprising feeding the feed stream, at an inlet pressure greater than atmospheric pressure and a temperature greater than 200.degree. C., to an integrated water gas shift/hydrogen separation membrane system wherein the hydrogen separation membrane system comprises a membrane that is selectively permeable to hydrogen, and producing a hydrogen-rich permeate product stream on the permeate side of the membrane and a carbon dioxide-rich product raffinate stream on the raffinate side of the membrane. A method for pretreating a membrane, comprising: heating the membrane to a desired operating temperature and desired feed pressure in a flow of inert gas for a sufficient time to cause the membrane to mechanically deform; decreasing the feed pressure to approximately ambient pressure; and optionally, flowing an oxidizing agent across the membrane before, during, or after deformation of the membrane. A method of supporting a hydrogen separation membrane system comprising selecting a hydrogen separation membrane system comprising one or more catalyst outer layers deposited on a hydrogen transport membrane layer and sealing the hydrogen separation membrane system to a porous support.

  16. Antiwear and antioxidant studies of cardanol phosphate ester additives

    Energy Technology Data Exchange (ETDEWEB)

    Mazzetto, S.E.; Oliveira, L.D.M.; Lomonaco, D.; Veloso, P.A., E-mail: selma@ufc.br [Lab. de Produtos e Tecnologia em Processos (LPT), Dept. de Quimica Organica e Inorganica, Universidade Federal do Ceara, Fortaleza, CE (Brazil)

    2012-07-15

    In the search for new applications and products derived from Cashew Nut Shell Liquid (CNSL), we report herein the synthesis and characterization (GC/MS and {sup 1}H, {sup 13}C, and {sup 31}P NMR) of four phosphate esters derived from hydrogenated cardanol, including their applications as antiwear additives for diesel (S500) and as antioxidant additives for mineral oils, evaluated through the HFRR test and oxidative stability analyses, respectively. The results obtained showed very good to excellent performances promoted by the bioadditives evaluated, especially for the thiophosphorylated derivative, which notably reduced the sludge residue and the acidity index of the oxidized oil (0.52 mg NaOH/g sample) and also improved the diesel lubricity, reducing the wear of metal parts by more than 50% (330 {Mu}m). Keywords: Cardanol; Antiwear; Antioxidant; Diesel; Mineral oil. (author)

  17. Antiwear and antioxidant studies of cardanol phosphate ester additives

    Directory of Open Access Journals (Sweden)

    S. E. Mazzetto

    2012-09-01

    Full Text Available In the search for new applications and products derived from Cashew Nut Shell Liquid (CNSL, we report herein the synthesis and characterization (GC/MS and ¹H, 13C, and 31P NMR of four phosphate esters derived from hydrogenated cardanol, including their applications as antiwear additives for diesel (S500 and as antioxidant additives for mineral oils, evaluated through the HFRR test and oxidative stability analyses, respectively. The results obtained showed very good to excellent performances promoted by the bio-additives evaluated, especially for the thiophosphorylated derivative, which notably reduced the sludge residue and the acidity index of the oxidized oil (0.52 mg NaOH/g sample and also improved the diesel lubricity, reducing the wear of metal parts by more than 50% (330 μm.

  18. Materials for hydrogen storage

    Directory of Open Access Journals (Sweden)

    Andreas Züttel

    2003-09-01

    The goal is to pack hydrogen as close as possible, i.e. to reach the highest volumetric density by using as little additional material as possible. Hydrogen storage implies the reduction of an enormous volume of hydrogen gas. At ambient temperature and atmospheric pressure, 1 kg of the gas has a volume of 11 m3. To increase hydrogen density, work must either be applied to compress the gas, the temperature decreased below the critical temperature, or the repulsion reduced by the interaction of hydrogen with another material.

  19. Solar Hydrogen Reaching Maturity

    Directory of Open Access Journals (Sweden)

    Rongé Jan

    2015-09-01

    Full Text Available Increasingly vast research efforts are devoted to the development of materials and processes for solar hydrogen production by light-driven dissociation of water into oxygen and hydrogen. Storage of solar energy in chemical bonds resolves the issues associated with the intermittent nature of sunlight, by decoupling energy generation and consumption. This paper investigates recent advances and prospects in solar hydrogen processes that are reaching market readiness. Future energy scenarios involving solar hydrogen are proposed and a case is made for systems producing hydrogen from water vapor present in air, supported by advanced modeling.

  20. Drug-pyridoxal phosphate interactions.

    Science.gov (United States)

    Ebadi, M; Gessert, C F; Al-Sayegh, A

    1982-01-01

    phosphate. Some interesting relationships are pointed out between vitamin B6, picolinic acid, and zinc. It is postulated that the intestinal absorption of zinc is facilitated by picolinic acid, a metabolite of tryptophan. The derivation of picolinic acid from tryptophan depends on the action of the enzyme kynureninase, which is dependent on pyridoxal phosphate; therefore, the adequate absorption of zinc is indirectly dependent on an adequate supply of vitamin B6. The formation of pyridoxal phosphate, on the other hand, appears to be indirectly dependent on Zn2++ which activates pyridoxal kinase.(ABSTRACT TRUNCATED AT 400 WORDS)

  1. Hydrogen energy assessment

    Energy Technology Data Exchange (ETDEWEB)

    Salzano, F J; Braun, C [eds.

    1977-09-01

    The purpose of this assessment is to define the near term and long term prospects for the use of hydrogen as an energy delivery medium. Possible applications of hydrogen are defined along with the associated technologies required for implementation. A major focus in the near term is on industrial uses of hydrogen for special applications. The major source of hydrogen in the near term is expected to be from coal, with hydrogen from electric sources supplying a smaller fraction. A number of potential applications for hydrogen in the long term are identified and the level of demand estimated. The results of a cost benefit study for R and D work on coal gasification to hydrogen and electrolytic production of hydrogen are presented in order to aid in defining approximate levels of R and D funding. A considerable amount of data is presented on the cost of producing hydrogen from various energy resources. A key conclusion of the study is that in time hydrogen is likely to play a role in the energy system; however, hydrogen is not yet competitive for most applications when compared to the cost of energy from petroleum and natural gas.

  2. Phosphate recycling in the phosphorus industry

    NARCIS (Netherlands)

    Schipper, W.J.; Klapwijk, A.; Potjer, A.; Rulkens, W.H.; Temmink, B.G.; Kiestra, F.D.G.; Lijmbach, A.C.M.

    2001-01-01

    The feasibility of phosphate recycling in the white phosphorus production process is discussed. Several types of materials may be recycled, provided they are dry inorganic materials, low in iron, copper and zinc. Sewage sludge ash may be used if no iron is used for phosphate precipitation in the tre

  3. Phosphate recycling in the phosphorus industry

    NARCIS (Netherlands)

    Schipper, W.J.; Klapwijk, A.; Potjer, B.; Rulkens, W.H.; Temmink, B.G.; Kiestra, F.D.G.; Lijmbach, A.C.M.

    2004-01-01

    The article describes the potential and limitations for recovery of phosphate from secondary materials in the production process for white phosphorus. This thermal process involves the feeding of phosphate rock, cokes and pebbles to a furnace. The reducing conditions in the furnace promote the forma

  4. Stable Development of Phosphate Fertilizer Sector

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ The rapid growth of China's economy in recent years gave rise to a sound external environment for the development of the phosphate fertilizer industry. With quite a few state agricultural incentives, the initiative of farmers in grain production is much higher, and consumption of phosphate fertilizers has increased constantly.

  5. Electrochemical phosphate recovery from nanofiltration concentrates

    NARCIS (Netherlands)

    Kappel, C.; Yasadi, K.; Temmink, B.G.; Metz, S.J.; Kemperman, A.J.B.; Nijmeijer, K.; Zwijnenburg, A.; Witkamp, G.J.; Rijnaarts, H.

    2013-01-01

    The high total phosphorus content of raw domestic wastewater with its significant eutrophication potential offers an excellent possibility for phosphate recovery. Continuous recirculation of NF concentrate to an MBR and simultaneous phosphate recovery from the NF concentrate can be applied to produc

  6. 21 CFR 520.823 - Erythromycin phosphate.

    Science.gov (United States)

    2010-04-01

    .... (a) Specifications. Erythromycin phosphate is the phosphate salt of the antibiotic substance produced by the growth of Streptomyces erythreus or the same antibiotic substance produced by any other means... chickens—(i) Amount. 0.500 gram per gallon. (ii) Indications for use. As an aid in the control of...

  7. Adsorption of Phosphate on Variable Charge Soils

    Institute of Scientific and Technical Information of China (English)

    HUGUO-SONG; ZHUZU-XIANG; 等

    1992-01-01

    The study about the adsorption of phosphate on four variable charge soils and some minerals revealed that two stage adsorption appeared in the adsorption isothems of phosphate on 4 soils and there was a maximum adsorption on Al-oxide-typed surfaces between pH 3.5 to pH 5.5 as suspension pH changed from 2 to 9,but the adsorption amount of phosphate decreased continually as pH rose on Fe-oxide typed surfaces.The adsorption amount of phosphate and the maximum phosphate adsorption pH decreased in the order of yellow-red soil> lateritic red soil> red soil> paddy soil,which was coincided with the content order of amorphous Al oxide.The removement of organic matter and Fe oxide made the maximum phosphate adsorption pH rise from 4.0 to 5.0 and 4.5,respectively.The desorption curves with pH of four soils showed that phosphate desorbed least at pH 5.Generally the desorption was contrary to the adsorption with pH changing.There was a good accordance between adsorption or desorption and the concentration of Al in the suspension.The possible mechanisms of phosphate adsorption are discussed.

  8. Hydrogen energy for beginners

    CERN Document Server

    2013-01-01

    This book highlights the outstanding role of hydrogen in energy processes, where it is the most functional element due to its unique peculiarities that are highlighted and emphasized in the book. The first half of the book covers the great natural hydrogen processes in biology, chemistry, and physics, showing that hydrogen is a trend that can unite all natural sciences. The second half of the book is devoted to the technological hydrogen processes that are under research and development with the aim to create the infrastructure for hydrogen energetics. The book describes the main features of hydrogen that make it inalienable player in processes such as fusion, photosynthesis, and metabolism. It also covers the methods of hydrogen production and storage, highlighting at the same time the exclusive importance of nanotechnologies in those processes.

  9. Photobiological hydrogen production.

    Science.gov (United States)

    Asada, Y; Miyake, J

    1999-01-01

    The principles and recent progress in the research and development of photobiological hydrogen production are reviewed. Cyanobacteria produce hydrogen gas using nitrogenase and/or hydrogenase. Hydrogen production mediated by native hydrogenases in cyanobacteria occurs under in the dark under anaerobic conditions by degradation of intracellular glycogen. In vitro and in vivo coupling of the cyanobacterial photosynthetic system with a clostridial hydrogenase via cyanobacterial ferredoxin was demonstrated in the presence of light. Genetic transformation of Synechococcus PCC7942 with the hydrogenase gene from Clostridium pasteurianum was successful; the active enzyme was expressed in PCC7942. The strong hydrogen producers among photosynthetic bacteria were isolated and characterized. Coculture of Rhodobacter and Clostriudium was applied for hydrogen production from glucose. A mutant strain of Rhodobacter sphaeroides RV whose light-harvesting proteins were altered was obtained by UV irradiation. Hydrogen productivity by the mutant was improved when irradiated with monochromatic light of some wavelengths. The development of photobioreactors for hydrogen production is also reviewed.

  10. Enantioselective Brønsted acid catalyzed transfer hydrogenation: organocatalytic reduction of imines.

    Science.gov (United States)

    Rueping, Magnus; Sugiono, Erli; Azap, Cengiz; Theissmann, Thomas; Bolte, Michael

    2005-08-18

    The first enantioselective Brønsted acid catalyzed reduction of imines has been developed. This new organocatalytic transfer hydrogenation of ketimines with Hantzsch dihydropyridine as the hydrogen source offers a mild method to various chiral amines with high enantioselectivity. The stereochemistry of the chiral amines can be rationalized by a stereochemical model derived from an X-ray crystal structure of a chiral BINOL phosphate catalyst. [reaction: see text

  11. Phosphate Biomineralization of Cambrian Microorganisms

    Science.gov (United States)

    McKay, David S.; Rozanov, Alexei Yu.; Hoover, Richard B.; Westall, Frances

    1998-01-01

    As part of a long term study of biological markers (biomarkers), we are documenting a variety of features which reflect the previous presence of living organisms. As we study meteorites and samples returned from Mars, our main clue to recognizing possible microbial material may be the presence of biomarkers rather than the organisms themselves. One class of biomarkers consists of biominerals which have either been precipitated directly by microorganisms, or whose precipitation has been influenced by the organisms. Such microbe-mediated mineral formation may include important clues to the size, shape, and environment of the microorganisms. The process of fossilization or mineralization can cause major changes in morphologies and textures of the original organisms. The study of fossilized terrestrial organisms can help provide insight into the interpretation of mineral biomarkers. This paper describes the results of investigations of microfossils in Cambrian phosphate-rich rocks (phosphorites) that were found in Khubsugul, Northern Mongolia.

  12. Genetics Home Reference: pyridoxal 5'-phosphate-dependent epilepsy

    Science.gov (United States)

    ... 5'-phosphate-dependent epilepsy pyridoxal 5'-phosphate-dependent epilepsy Enable Javascript to view the expand/collapse boxes. ... All Close All Description Pyridoxal 5'-phosphate-dependent epilepsy is a condition that involves seizures beginning soon ...

  13. Potential Application of Biohydrogen Production Liquid Waste as Phosphate Solubilizing Agent-A Study Using Soybean Plants.

    Science.gov (United States)

    Sarma, Saurabh Jyoti; Brar, Satinder Kaur; LeBihan, Yann; Buelna, Gerardo

    2016-03-01

    With CO2 free emission and a gravimetric energy density higher than gasoline, diesel, biodiesel, and bioethanol, biohydrogen is a promising green renewable energy carrier. During fermentative hydrogen production, 60-70 % of the feedstock is converted to different by-products, dominated by organic acids. In the present investigation, a simple approach for value addition of hydrogen production liquid waste (HPLW) containing these compounds has been demonstrated. In soil, organic acids produced by phosphate solubilizing bacteria chelate the cations of insoluble inorganic phosphates (e.g., Ca3 (PO4)2) and make the phosphorus available to the plants. Organic acid-rich HPLW, therefore, has been evaluated as soil phosphate solubilizer. Application of HPLW as soil phosphate solubilizer was found to improve the phosphorus uptake of soybean plants by 2.18- to 2.74-folds. Additionally, 33-100 % increase in seed germination rate was also observed. Therefore, HPLW has the potential to be an alternative for phosphate solubilizing biofertilizers available in the market. Moreover, the strategy can be useful for phytoremediation of phosphorus-rich soil.

  14. Hydrolysis of dicalcium phosphate dihydrate to hydroxyapatite.

    Science.gov (United States)

    Fulmer, M T; Brown, P W

    1998-04-01

    Dicalcium phosphate dihydrate (DCPD) was hydrolysed in water and in 1 M Na2HPO4 solution at temperatures from 25-60 degrees C. Hydrolysis was incomplete in water. At 25 degrees C, DCPD partially hydrolysed to hydroxyapatite (HAp). Formation of HAp is indicative of incongruent DCPD dissolution. At the higher temperatures, hydrolysis to HAp was more extensive and was accompanied by the formation of anhydrous dicalcium phosphate (DCP). Both of these processes are endothermic. When hydrolysis was carried out in 1 M Na2HPO4 solution, heat absorption was greater at any given temperature than for hydrolysis in water. Complete hydrolysis to HAp occurred in this solution. The hydrolysis of DCPD to HAp in sodium phosphate solution was also endothermic. The complete conversion of DCPD to HAp in sodium phosphate solution would not be expected if the only effect of this solution was to cause DCPD dissolution to become congruent. Because of the buffering capacity of a dibasic sodium phosphate solution, DCPD hydrolysed completely to HAp. Complete conversion to HAp was accompanied by the conversion of dibasic sodium phosphate to monobasic sodium phosphate. The formation of DCP was not observed indicating that the sodium phosphate solution precluded the DCPD-to-DCP dehydration reaction. In addition to affecting the extent of hydrolysis, reaction in the sodium phosphate solution also caused a morphological change in the HAp which formed. HAp formed by hydrolysis in water was needle-like to globular while that formed in the sodium phosphate solution exhibited a florette-like morphology.

  15. Study of the degree of deuteration on the microhardness of deuterated potassium dihydrogen phosphate crystals

    Indian Academy of Sciences (India)

    Baoan Liu; Shaotao Sun; Bo Wang; Xun Sun; Zhengping Wang; Xinguang Xu

    2015-08-01

    A series of deuterated potassium dihydrogen phosphate (DKDP) crystals with different degrees of deuteration are grown from aqueous solution by the point-seed technique. The microhardness of (100), (001) and so-called ‘tripler’ faces for these DKDP crystals were measured. Initially the hardness number of (001) face for each crystal increases with the increase of the applied load until it reaches 25 g. With further increase in load, the hardness number decreases gradually. The hardness numbers decline with the increase in deuterium content. These composition dependences are expected since the bond strength is weakened by the substitution of deuterium for hydrogen. The hydrogen bond is considered to play the key role in effecting the crystal’s hardness. The visible hardness anisotropy of the different faces is attributed to the inhomogeneous distribution of the oxygen–hydrogen bond on these faces.

  16. Dominant oceanic bacteria secure phosphate using a large extracellular buffer

    OpenAIRE

    M. V. Zubkov; Martin, A. P.; Hartmann, M.; Grob, C.; Scanlan, D.J.

    2015-01-01

    The ubiquitous SAR11 and Prochlorococcus bacteria manage to maintain a sufficient supply of phosphate in phosphate-poor surface waters of the North Atlantic subtropical gyre. Furthermore, it seems that their phosphate uptake may counter-intuitively be lower in more productive tropical waters, as if their cellular demand for phosphate decreases there. By flow sorting 33P-phosphate-pulsed 32P-phosphate-chased cells, we demonstrate that both Prochlorococcus and SAR11 cells exploit an extracellul...

  17. Hydrogen Filling Station

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, Robert F; Sabacky, Bruce; Anderson II, Everett B; Haberman, David; Al-Hassin, Mowafak; He, Xiaoming; Morriseau, Brian

    2010-02-24

    Hydrogen is an environmentally attractive transportation fuel that has the potential to displace fossil fuels. The Freedom CAR and Freedom FUEL initiatives emphasize the importance of hydrogen as a future transportation fuel. Presently, Las Vegas has one hydrogen fueling station powered by natural gas. However, the use of traditional sources of energy to produce hydrogen does not maximize the benefit. The hydrogen fueling station developed under this grant used electrolysis units and solar energy to produce hydrogen fuel. Water and electricity are furnished to the unit and the output is hydrogen and oxygen. Three vehicles were converted to utilize the hydrogen produced at the station. The vehicles were all equipped with different types of technologies. The vehicles were used in the day-to-day operation of the Las Vegas Valley Water District and monitoring was performed on efficiency, reliability and maintenance requirements. The research and demonstration utilized for the reconfiguration of these vehicles could lead to new technologies in vehicle development that could make hydrogen-fueled vehicles more cost effective, economical, efficient and more widely used. In order to advance the development of a hydrogen future in Southern Nevada, project partners recognized a need to bring various entities involved in hydrogen development and deployment together as a means of sharing knowledge and eliminating duplication of efforts. A road-mapping session was held in Las Vegas in June 2006. The Nevada State Energy Office, representatives from DOE, DOE contractors and LANL, NETL, NREL were present. Leadership from the National hydrogen Association Board of Directors also attended. As a result of this session, a roadmap for hydrogen development was created. This roadmap has the ability to become a tool for use by other road-mapping efforts in the hydrogen community. It could also become a standard template for other states or even countries to approach planning for a hydrogen

  18. Hydrogen Filling Station

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, Robert F; Sabacky, Bruce; Anderson II, Everett B; Haberman, David; Al-Hassin, Mowafak; He, Xiaoming; Morriseau, Brian

    2010-02-24

    Hydrogen is an environmentally attractive transportation fuel that has the potential to displace fossil fuels. The Freedom CAR and Freedom FUEL initiatives emphasize the importance of hydrogen as a future transportation fuel. Presently, Las Vegas has one hydrogen fueling station powered by natural gas. However, the use of traditional sources of energy to produce hydrogen does not maximize the benefit. The hydrogen fueling station developed under this grant used electrolysis units and solar energy to produce hydrogen fuel. Water and electricity are furnished to the unit and the output is hydrogen and oxygen. Three vehicles were converted to utilize the hydrogen produced at the station. The vehicles were all equipped with different types of technologies. The vehicles were used in the day-to-day operation of the Las Vegas Valley Water District and monitoring was performed on efficiency, reliability and maintenance requirements. The research and demonstration utilized for the reconfiguration of these vehicles could lead to new technologies in vehicle development that could make hydrogen-fueled vehicles more cost effective, economical, efficient and more widely used. In order to advance the development of a hydrogen future in Southern Nevada, project partners recognized a need to bring various entities involved in hydrogen development and deployment together as a means of sharing knowledge and eliminating duplication of efforts. A road-mapping session was held in Las Vegas in June 2006. The Nevada State Energy Office, representatives from DOE, DOE contractors and LANL, NETL, NREL were present. Leadership from the National hydrogen Association Board of Directors also attended. As a result of this session, a roadmap for hydrogen development was created. This roadmap has the ability to become a tool for use by other road-mapping efforts in the hydrogen community. It could also become a standard template for other states or even countries to approach planning for a hydrogen

  19. Ultrafast phosphate hydration dynamics in bulk H{sub 2}O

    Energy Technology Data Exchange (ETDEWEB)

    Costard, Rene, E-mail: costard@mbi-berlin.de; Tyborski, Tobias; Fingerhut, Benjamin P., E-mail: fingerhut@mbi-berlin.de; Elsaesser, Thomas [Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, D-12489 Berlin (Germany)

    2015-06-07

    Phosphate vibrations serve as local probes of hydrogen bonding and structural fluctuations of hydration shells around ions. Interactions of H{sub 2}PO{sub 4}{sup −} ions and their aqueous environment are studied combining femtosecond 2D infrared spectroscopy, ab-initio calculations, and hybrid quantum-classical molecular dynamics (MD) simulations. Two-dimensional infrared spectra of the symmetric (ν{sub S}(PO{sub 2}{sup −})) and asymmetric (ν{sub AS}(PO{sub 2}{sup −})) PO{sub 2}{sup −} stretching vibrations display nearly homogeneous lineshapes and pronounced anharmonic couplings between the two modes and with the δ(P-(OH){sub 2}) bending modes. The frequency-time correlation function derived from the 2D spectra consists of a predominant 50 fs decay and a weak constant component accounting for a residual inhomogeneous broadening. MD simulations show that the fluctuating electric field of the aqueous environment induces strong fluctuations of the ν{sub S}(PO{sub 2}{sup −}) and ν{sub AS}(PO{sub 2}{sup −}) transition frequencies with larger frequency excursions for ν{sub AS}(PO{sub 2}{sup −}). The calculated frequency-time correlation function is in good agreement with the experiment. The ν(PO{sub 2}{sup −}) frequencies are mainly determined by polarization contributions induced by electrostatic phosphate-water interactions. H{sub 2}PO{sub 4}{sup −}/H{sub 2}O cluster calculations reveal substantial frequency shifts and mode mixing with increasing hydration. Predicted phosphate-water hydrogen bond (HB) lifetimes have values on the order of 10 ps, substantially longer than water-water HB lifetimes. The ultrafast phosphate-water interactions observed here are in marked contrast to hydration dynamics of phospholipids where a quasi-static inhomogeneous broadening of phosphate vibrations suggests minor structural fluctuations of interfacial water.

  20. Hydrogen energy systems studies

    Energy Technology Data Exchange (ETDEWEB)

    Ogden, J.M.; Steinbugler, M.; Kreutz, T. [Princeton Univ., NJ (United States). Center for Energy and Environmental Studies

    1998-08-01

    In this progress report (covering the period May 1997--May 1998), the authors summarize results from ongoing technical and economic assessments of hydrogen energy systems. Generally, the goal of their research is to illuminate possible pathways leading from present hydrogen markets and technologies toward wide scale use of hydrogen as an energy carrier, highlighting important technologies for RD and D. Over the past year they worked on three projects. From May 1997--November 1997, the authors completed an assessment of hydrogen as a fuel for fuel cell vehicles, as compared to methanol and gasoline. Two other studies were begun in November 1997 and are scheduled for completion in September 1998. The authors are carrying out an assessment of potential supplies and demands for hydrogen energy in the New York City/New Jersey area. The goal of this study is to provide useful data and suggest possible implementation strategies for the New York City/ New Jersey area, as the Hydrogen Program plans demonstrations of hydrogen vehicles and refueling infrastructure. The authors are assessing the implications of CO{sub 2} sequestration for hydrogen energy systems. The goals of this work are (a) to understand the implications of CO{sub 2} sequestration for hydrogen energy system design; (b) to understand the conditions under which CO{sub 2} sequestration might become economically viable; and (c) to understand design issues for future low-CO{sub 2} emitting hydrogen energy systems based on fossil fuels.

  1. Application of Potential Phosphate-Solubilizing Bacteria and Organic Acids on Phosphate Solubilization from Phosphate Rock in Aerobic Rice

    OpenAIRE

    Qurban Ali Panhwar; Shamshuddin Jusop; Umme Aminun Naher; Radziah Othman; Mohd Ismail Razi

    2013-01-01

    A study was conducted at Universiti Putra Malaysia to determine the effect of phosphate-solubilizing bacteria (PSB) and organic acids (oxalic & malic) on phosphate (P) solubilization from phosphate rock (PR) and growth of aerobic rice. Four rates of each organic acid (0, 10, 20, and 30 mM), and PSB strain (Bacillus sp.) were applied to aerobic rice. Total bacterial populations, amount of P solubilization, P uptake, soil pH, and root morphology were determined. The results of the study showed ...

  2. Hydrogen Fuelling Stations

    DEFF Research Database (Denmark)

    Rothuizen, Erasmus Damgaard

    This thesis concerns hydrogen fuelling stations from an overall system perspective. The study investigates thermodynamics and energy consumption of hydrogen fuelling stations for fuelling vehicles for personal transportation. For the study a library concerning the components in a hydrogen fuelling...... station has been developed in Dymola. The models include the fuelling protocol (J2601) for hydrogen vehicles made by Society of Automotive Engineers (SAE) and the thermodynamic property library CoolProp is used for retrieving state point. The components in the hydrogen fuelling library are building up....... A system consisting of one high pressure storage tank is used to investigate the thermodynamics of fuelling a hydrogen vehicle. The results show that the decisive parameter for how the fuelling proceeds is the pressure loss in the vehicle. The single tank fuelling system is compared to a cascade fuelling...

  3. Scandinavian hydrogen highway partnership

    Energy Technology Data Exchange (ETDEWEB)

    Sloth, M.; Hansen, J. [H2 Logic A/S, Herning (Denmark); Wennike, F. [Hydrogen Link Denmark Association, Ringkoebing (Denmark)

    2009-07-01

    The Scandinavian Hydrogen Highway Partnership (SHHP) was launched in an effort to build hydrogen filling stations in Scandinavian countries by 2012 in order to enable hydrogen powered vehicles to operate and refuel when needed. Three hydrogen refueling stations are currently in operation in Scandinavia to fuel a fleet of 15 hydrogen-fuelled cars. It is anticipated that by the end of 2009, there will be 14 hydrogen refueling stations and more than 70 vehicles in operation. Beyond 2012, the number of filling stations and vehicles is expected to increase significantly through large scale demonstration, where SHHP aims to attract funding from the European Union. The current activities of SHHP are co-funded by national and regional authorities. The SHHP network is funded by Nordic Energy Research.

  4. Aging dynamics in ferroelectric deuterated potassium dihydrogen phosphate

    Science.gov (United States)

    Hecht, Rachel; Cieszymski, Samuel F.; Colla, Eugene V.; Weissman, M. B.

    2017-09-01

    Anomalously large dielectric aging is found in the high-susceptibility plateau ferroelectric regime of nominally ˜95 % deuterated potassium dihydrogen phosphate (DKDP). Much less aging is found in nondeuterated KDP throughout most of its plateau region. Optical images of the DKDP domain structure show no dramatic change during aging. Small changes in electric field restore the preaged susceptibility, but the previous aging almost recovers after returning to a respective aging field. Susceptibility vs field can show memory of at least two prior aging fields. Aging effects are not fully erased even by brief heating above the Curie point, indicating a role for diffusion of hydrogen to the domain walls, leaving changes in disorder that can survive temporary absence of domain walls. Asymmetrical nonlinear susceptibility develops for fields slightly above or below a prior aging field and during field sweeps, with the dependence of the second-harmonic magnitude on sweep rate giving a characteristic time comparable to the time for hydrogen to diffuse a domain-wall width.

  5. Hydrogen storage container

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jy-An John; Feng, Zhili; Zhang, Wei

    2017-02-07

    An apparatus and system is described for storing high-pressure fluids such as hydrogen. An inner tank and pre-stressed concrete pressure vessel share the structural and/or pressure load on the inner tank. The system and apparatus provide a high performance and low cost container while mitigating hydrogen embrittlement of the metal tank. System is useful for distributing hydrogen to a power grid or to a vehicle refueling station.

  6. Hydrogen energy systems studies

    Energy Technology Data Exchange (ETDEWEB)

    Ogden, J.M.; Steinbugler, M.; Dennis, E. [Princeton Univ., NJ (United States)] [and others

    1995-09-01

    For several years, researchers at Princeton University`s Center for Energy and Environmental Studies have carried out technical and economic assessments of hydrogen energy systems. Initially, we focussed on the long term potential of renewable hydrogen. More recently we have explored how a transition to renewable hydrogen might begin. The goal of our current work is to identify promising strategies leading from near term hydrogen markets and technologies toward eventual large scale use of renewable hydrogen as an energy carrier. Our approach has been to assess the entire hydrogen energy system from production through end-use considering technical performance, economics, infrastructure and environmental issues. This work is part of the systems analysis activity of the DOE Hydrogen Program. In this paper we first summarize the results of three tasks which were completed during the past year under NREL Contract No. XR-11265-2: in Task 1, we carried out assessments of near term options for supplying hydrogen transportation fuel from natural gas; in Task 2, we assessed the feasibility of using the existing natural gas system with hydrogen and hydrogen blends; and in Task 3, we carried out a study of PEM fuel cells for residential cogeneration applications, a market which might have less stringent cost requirements than transportation. We then give preliminary results for two other tasks which are ongoing under DOE Contract No. DE-FG04-94AL85803: In Task 1 we are assessing the technical options for low cost small scale production of hydrogen from natural gas, considering (a) steam reforming, (b) partial oxidation and (c) autothermal reforming, and in Task 2 we are assessing potential markets for hydrogen in Southern California.

  7. Liquid hydrogen in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Yasumi, S. [Iwatani Corp., Osaka (Japan). Dept. of Overseas Business Development

    2009-07-01

    Japan's Iwatani Corporation has focused its attention on hydrogen as the ultimate energy source in future. Unlike the United States, hydrogen use and delivery in liquid form is extremely limited in the European Union and in Japan. Iwatani Corporation broke through industry stereotypes by creating and building Hydro Edge Co. Ltd., Japan's largest liquid hydrogen plant. It was established in 2006 as a joint venture between Iwatani and Kansai Electric Power Group in Osaka. Hydro Edge is Japan's first combined liquid hydrogen and ASU plant, and is fully operational. Liquid oxygen, liquid nitrogen and liquid argon are separated from air using the cryogenic energy of liquefied natural gas fuel that is used for power generation. Liquid hydrogen is produced efficiently and simultaneously using liquid nitrogen. Approximately 12 times as much hydrogen in liquid form can be transported and supplied as pressurized hydrogen gas. This technology is a significant step forward in the dissemination and expansion of hydrogen in a hydrogen-based economy.

  8. Triethylammonium hydrogen chloranilate

    Directory of Open Access Journals (Sweden)

    Kazuma Gotoh

    2010-12-01

    Full Text Available In the crystal structure of the title compound (systematic name: triethylammonium 2,5-dichloro-4-hydroxy-3,6-dioxocyclohexa-1,4-dien-1-olate, C6H16N+·C6HCl2O4−, two hydrogen chloranilate anions are connected by a pair of bifurcated O—H...O hydrogen bonds into a dimeric unit. The triethylammonium cations are linked on both sides of the dimer via bifurcated N—H...O hydrogen bonds into a centrosymmetric 2:2 aggregate. The 2:2 aggregates are further linked by intermolecular C—H...O hydrogen bonds.

  9. Sphingosine 1-phosphate and cancer.

    Science.gov (United States)

    Pyne, Nigel J; El Buri, Ashref; Adams, David R; Pyne, Susan

    2017-09-15

    The bioactive lipid, sphingosine 1-phosphate (S1P) is produced by phosphorylation of sphingosine and this is catalysed by two sphingosine kinase isoforms (SK1 and SK2). Here we discuss structural functional aspects of SK1 (which is a dimeric quaternary enzyme) that relate to coordinated coupling of membrane association with phosphorylation of Ser225 in the 'so-called' R-loop, catalytic activity and protein-protein interactions (e.g. TRAF2, PP2A and Gq). S1P formed by SK1 at the plasma-membrane is released from cells via S1P transporters to act on S1P receptors to promote tumorigenesis. We discuss here an additional novel mechanism that can operate between cancer cells and fibroblasts and which involves the release of the S1P receptor, S1P2 in exosomes from breast cancer cells that regulates ERK-1/2 signalling in fibroblasts. This novel mechanism of signalling might provide an explanation for the role of S1P2 in promoting metastasis of cancer cells and which is dependent on the micro-environmental niche. Copyright © 2017. Published by Elsevier Ltd.

  10. Florida Hydrogen Initiative

    Energy Technology Data Exchange (ETDEWEB)

    Block, David L

    2013-06-30

    The Florida Hydrogen Initiative (FHI) was a research, development and demonstration hydrogen and fuel cell program. The FHI program objectives were to develop Florida?s hydrogen and fuel cell infrastructure and to assist DOE in its hydrogen and fuel cell activities The FHI program funded 12 RD&D projects as follows: Hydrogen Refueling Infrastructure and Rental Car Strategies -- L. Lines, Rollins College This project analyzes strategies for Florida's early stage adaptation of hydrogen-powered public transportation. In particular, the report investigates urban and statewide network of refueling stations and the feasibility of establishing a hydrogen rental-car fleet based in Orlando. Methanol Fuel Cell Vehicle Charging Station at Florida Atlantic University ? M. Fuchs, EnerFuel, Inc. The project objectives were to design, and demonstrate a 10 kWnet proton exchange membrane fuel cell stationary power plant operating on methanol, to achieve an electrical energy efficiency of 32% and to demonstrate transient response time of less than 3 milliseconds. Assessment of Public Understanding of the Hydrogen Economy Through Science Center Exhibits, J. Newman, Orlando Science Center The project objective was to design and build an interactive Science Center exhibit called: ?H2Now: the Great Hydrogen Xchange?. On-site Reformation of Diesel Fuel for Hydrogen Fueling Station Applications ? A. Raissi, Florida Solar Energy Center This project developed an on-demand forecourt hydrogen production technology by catalytically converting high-sulfur hydrocarbon fuels to an essentially sulfur-free gas. The removal of sulfur from reformate is critical since most catalysts used for the steam reformation have limited sulfur tolerance. Chemochromic Hydrogen Leak Detectors for Safety Monitoring ? N. Mohajeri and N. Muradov, Florida Solar Energy Center This project developed and demonstrated a cost-effective and highly selective chemochromic (visual) hydrogen leak detector for safety

  11. Electrochemical hydrogen Storage Systems

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Digby Macdonald

    2010-08-09

    As the global need for energy increases, scientists and engineers have found a possible solution by using hydrogen to power our world. Although hydrogen can be combusted as a fuel, it is considered an energy carrier for use in fuel cells wherein it is consumed (oxidized) without the production of greenhouse gases and produces electrical energy with high efficiency. Chemical storage of hydrogen involves release of hydrogen in a controlled manner from materials in which the hydrogen is covalently bound. Sodium borohydride and aminoborane are two materials given consideration as chemical hydrogen storage materials by the US Department of Energy. A very significant barrier to adoption of these materials as hydrogen carriers is their regeneration from 'spent fuel,' i.e., the material remaining after discharge of hydrogen. The U.S. Department of Energy (DOE) formed a Center of Excellence for Chemical Hydrogen Storage, and this work stems from that project. The DOE has identified boron hydrides as being the main compounds of interest as hydrogen storage materials. The various boron hydrides are then oxidized to release their hydrogen, thereby forming a 'spent fuel' in the form of a lower boron hydride or even a boron oxide. The ultimate goal of this project is to take the oxidized boron hydrides as the spent fuel and hydrogenate them back to their original form so they can be used again as a fuel. Thus this research is essentially a boron hydride recycling project. In this report, research directed at regeneration of sodium borohydride and aminoborane is described. For sodium borohydride, electrochemical reduction of boric acid and sodium metaborate (representing spent fuel) in alkaline, aqueous solution has been investigated. Similarly to literature reports (primarily patents), a variety of cathode materials were tried in these experiments. Additionally, approaches directed at overcoming electrostatic repulsion of borate anion from the cathode, not

  12. Enhancing hydrogen spillover and storage

    Science.gov (United States)

    Yang, Ralph T.; Li, Yingwel; Lachawiec, Jr., Anthony J.

    2011-05-31

    Methods for enhancing hydrogen spillover and storage are disclosed. One embodiment of the method includes doping a hydrogen receptor with metal particles, and exposing the hydrogen receptor to ultrasonification as doping occurs. Another embodiment of the method includes doping a hydrogen receptor with metal particles, and exposing the doped hydrogen receptor to a plasma treatment.

  13. Enhancing hydrogen spillover and storage

    Science.gov (United States)

    Yang, Ralph T; Li, Yingwei; Lachawiec, Jr., Anthony J

    2013-02-12

    Methods for enhancing hydrogen spillover and storage are disclosed. One embodiment of the method includes doping a hydrogen receptor with metal particles, and exposing the hydrogen receptor to ultrasonication as doping occurs. Another embodiment of the method includes doping a hydrogen receptor with metal particles, and exposing the doped hydrogen receptor to a plasma treatment.

  14. Combination moisture and hydrogen getter

    Science.gov (United States)

    Harrah, L.A.; Mead, K.E.; Smith, H.M.

    1983-09-20

    A combination moisture and hydrogen getter comprises (a) a moisture getter comprising a readily oxidizable metal; and (b) a hydrogen getter comprising (1) a solid acetylenic compound and (2) a hydrogenation catalyst. A method of scavenging moisture from a closed container uses the combination moisture and hydrogen getter to irreversibly chemically reduce the moisture and chemically bind the resultant hydrogen.

  15. Enzyme activity in dialkyl phosphate ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, M.F.; Dunn, J.; Li, L.-L.; Handley-Pendleton, J. M.; van der lelie, D.; Wishart, J. F.

    2011-12-01

    The activity of four metagenomic enzymes and an enzyme cloned from the straw mushroom, Volvariellavolvacea were studied in the following ionic liquids, 1,3-dimethylimidazolium dimethyl phosphate, [mmim][dmp], 1-ethyl-3-methylimidazolium dimethyl phosphate, [emim][dmp], 1-ethyl-3-methylimidazolium diethyl phosphate, [emim][dep] and 1-ethyl-3-methylimidazolium acetate, [emim][OAc]. Activity was determined by analyzing the hydrolysis of para-nitrobenzene carbohydrate derivatives. In general, the enzymes were most active in the dimethyl phosphate ionic liquids, followed by acetate. Generally speaking, activity decreased sharply for concentrations of [emim][dep] above 10% v/v, while the other ionic liquids showed less impact on activity up to 20% v/v.

  16. Enzyme activity in dialkyl phosphate ionic liquids.

    Science.gov (United States)

    Thomas, Marie F; Li, Luen-Luen; Handley-Pendleton, Jocelyn M; van der Lelie, Daniel; Dunn, John J; Wishart, James F

    2011-12-01

    The activity of four metagenomic enzymes and an enzyme cloned from the straw mushroom, Volvariella volvacea were studied in the following ionic liquids, 1,3-dimethylimidazolium dimethyl phosphate, [mmim][dmp], 1-ethyl-3-methylimidazolium dimethyl phosphate, [emim][dmp], 1-ethyl-3-methylimidazolium diethyl phosphate, [emim][dep] and 1-ethyl-3-methylimidazolium acetate, [emim][OAc]. Activity was determined by analyzing the hydrolysis of para-nitrobenzene carbohydrate derivatives. In general, the enzymes were most active in the dimethyl phosphate ionic liquids, followed by acetate. Generally speaking, activity decreased sharply for concentrations of [emim][dep] above 10% v/v, while the other ionic liquids showed less impact on activity up to 20% v/v.

  17. Synthesis of Caged Bicyclic Phosphate Derivatives

    Institute of Scientific and Technical Information of China (English)

    FANG Xiao-min; OU Yu-xiang; LUO Rui-bin; WANG Yong; LIAN Dan-jun; LI Xin

    2008-01-01

    Seven caged bicyclic phosphate compounds were synthesized by using 1-oxo-4-hydroxymethy1-2,6,7-trioxa-1-pho-sphabicyclo[2.2.2] octane (PEPA) as starting material. Within them were three PEPA derivatives containing single caged bicyclic phosphate structure(1a,2a,3a), another three PEPA deviratives containing two caged bicyclic phosphate structures(1b,2b,3b) and one devirative(1c) containing three caged bicyclic phosphate structures. Structures of the products were characterized by FTIR, 1H NMR, elemental analysis and TG analysis. The reaction conditions were also discussed. Thermal analysis showed they had high thermal stability and excellent char-forming ability. Besides, these compounds had pentaerythritol bone and flame retardant elements of phosphorus, bromine or nitrogen simultaneously in their molecules, endowed them with good fire retardancy, and made them can be used as intumescent flame retardant.

  18. Pyridoxal Phosphate vs Pyridoxine for Intractable Seizures

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2005-05-01

    Full Text Available The efficacy of pyridoxal phosphate (PLP compared to pyridoxine (PN in the control of idiopathic intractable epilepsy was studied in 94 children, aged 8 months to 15 years, at the National Taiwan University Hospital, Taipei, Taiwan.

  19. Spectrophotometric Determination of Nitrate and Phosphate Levels ...

    African Journals Online (AJOL)

    Twelve drinking water samples from boreholes were collected from various sampling sites around the vicinity of Kura irrigated farmlands ... all the sampling sites had phosphate level above the World Health Organization maximum contaminant ...

  20. Performance of pineapple slips inoculated with diazotrophic phosphate-solubilizing bacteria and rock phosphate

    OpenAIRE

    Lílian Estrela Borges Baldotto; Marihus Altoé Baldotto; Fábio Lopes Olivares; Adriane Nunes de Souza

    2014-01-01

    Besides fixing N2, some diazotrophic bacteria or diazotrophs, also synthesize organic acids and are able to solubilize rock phosphates, increasing the availability of P for plants. The application of these bacteria to pineapple leaf axils in combination with rock phosphate could increase N and P availability for the crop, due to the bacterial activity of biological nitrogen fixation and phosphate solubilization. The objectives of this study were: (i) to select and characterize diazotrophs abl...

  1. The effect of two bleaching agents on the phosphate concentration of the enamel evaluated by Raman spectroscopy: An ex vivo study

    Directory of Open Access Journals (Sweden)

    Sokkalingam Mothilal Venkatesan

    2012-01-01

    Full Text Available Aim : The aim of this ex vivo study was to evaluate the effect of in-office bleaching agents,-35% and 38% hydrogen peroxide containing bleaching agents, on the phosphate concentration of the enamel evaluated by Raman spectroscopy. Materials and Methods : Forty noncarious, craze-free human maxillary incisors, extracted for periodontal reasons, were used in this study. Baseline Raman spectra from each specimen were obtained before the application of the bleaching agent to assess the phosphate content present in the teeth. The teeth were divided into two groups: Group A - bleached with pola office bleach (35% hydrogen peroxide, potassium nitrate (light activated. Group B - bleached with opalescence Xtra bleach (38% hydrogen peroxide potassium nitrate and fluoride (chemical activated. After the bleaching procedure, the treated specimens were taken to obtain Raman spectra to assess the phosphate loss after bleaching treatment. Results : The results showed that the chemically activated bleaching agent showed less phosphate loss when compared with the light activated bleaching agent. Conclusion : Within the limitations of this study, it can be concluded that the chemically activated bleaching agent showed minimal phosphate loss when compared to light activated bleaching agent. The chemically activated bleaching agent was better than the light activated bleaching agent when values were evaluated statistically.

  2. Physical Properties of Acidic Calcium Phosphate Cements

    OpenAIRE

    2014-01-01

    The gold standard for bone replacement today, autologous bone, suffers from several disadvantages, such as the increased risk of infection due to the need for two surgeries. Degradable synthetic materials with properties similar to bone, such as calcium phosphate cements, are a promising alternative. Calcium phosphate cements are suited for a limited amount of applications and improving their physical properties could extend their use into areas previously not considered possible. For example...

  3. An investigation of iron phosphate glasses

    Science.gov (United States)

    Fang, Xiangyu

    The effect of melting history on the iron redox equilibrium, structure, crystallization and properties of a binary iron phosphate glass with a 40Fe 2O3-60P2O5, mol%, batch composition were investigated. The structure and properties of single and mixed alkali iron phosphate glasses were also studied. Mossbauer, Raman and infrared spectroscopy were used to determine the changes in the concentration of iron ions and phosphate units in the structure. Differential thermal analysis, X-ray diffraction and thermogravimetric analysis were used to investigate crystallization. Density, molar volume, thermal expansion, dc electrical conductivity and dielectric constant and loss tangent were measured. The heat capacity and glass transition behavior of the glasses was also measured by the differential scanning calorimeter method. The effect of the melting temperature is stronger than the melting time on the concentration of Fe2+ ions in iron phosphate glasses. The pyrophosphate network in iron phosphate glasses and their general properties do not change either with melting temperature and time or with adding up to 20 mol% of single and mixed alkali oxides. The dissolution rate (in deionized water) of these glasses is generally very low (˜10-9 g/cm2/min) and nearly independent of the relative concentration of Fe 2+ or Fe3+ ions. The dissolution rate of the iron phosphate glasses containing 20 mol% of single or mixed alkali oxide can be comparable to that of window glass. There is no mixed alkali effect in the iron phosphate glasses. The crystallization tendency indicates that the glass structure becomes closer to that of crystalline Fe3(P2O 7)2 with increasing concentration of Fe2+ ions in the glass. The large fragility parameters indicates that the iron phosphate glasses belong in the category of the fragile glass-forming liquids.

  4. Membrane for hydrogen recovery from streams containing hydrogen sulfide

    Science.gov (United States)

    Agarwal, Pradeep K.

    2007-01-16

    A membrane for hydrogen recovery from streams containing hydrogen sulfide is provided. The membrane comprises a substrate, a hydrogen permeable first membrane layer deposited on the substrate, and a second membrane layer deposited on the first layer. The second layer contains sulfides of transition metals and positioned on the on a feed side of the hydrogen sulfide stream. The present invention also includes a method for the direct decomposition of hydrogen sulfide to hydrogen and sulfur.

  5. Isolation of phosphate-solubilizing fungus and its application in solubilization of rock phosphates.

    Science.gov (United States)

    Wu, Yingben; He, Yuelin; Yin, Hongmei; Chen, Wei; Wang, Zhen; Xu, Lijuan; Zhang, Aiqun

    2012-12-01

    Microorganisms have been obtained to improve the agronomic value of rock phosphates (RPs), but the phosphorus solubilizing rate by these approaches is very slow. It is important to explore a high-efficient phosphate-solubilizing approach with a kind of microorganisms. This study aimed to isolate a high-efficient level of phosphate-solubilizing fungus from rhizosphere soil samples phosphate mines (Liuyang County, Hunan province, China) and apply it in solubilization of RPs. The experiments were carried out by the conventional methodology for morphological and biochemical fungus characterization and the analysis of 18s rRNA sequence. Then the effects of time, temperature, initial pH, phosphorus (P) sources, RPs concentration, shaking speed and silver ion on the content of soluble P released by this isolate were investigated. The results showed this isolate was identified as Galactomyces geotrichum P14 (P14) in GeneBank and the maximum amount of soluble P was 1252.13 mg L(-1) within 40 h in a modified phosphate growth agar's medium (without agar) where contained tricalcium phosphate (TCP) as sole phosphate source. At the same time, it could release phosphate and solubilize various rock phosphates. The isolated fungus can convert RPs from insoluble form into plant available form and therefore it hold great potential for biofertilizers to enhance soil fertility and promote plant growth.

  6. Using phosphate supplementation to reverse hypophosphatemia and phosphate depletion in neurological disease and disturbance.

    Science.gov (United States)

    Håglin, Lena

    2016-06-01

    Hypophosphatemia (HP) with or without intracellular depletion of inorganic phosphate (Pi) and adenosine triphosphate has been associated with central and peripheral nervous system complications and can be observed in various diseases and conditions related to respiratory alkalosis, alcoholism (alcohol withdrawal), diabetic ketoacidosis, malnutrition, obesity, and parenteral and enteral nutrition. In addition, HP may explain serious muscular, neurological, and haematological disorders and may cause peripheral neuropathy with paresthesias and metabolic encephalopathy, resulting in confusion and seizures. The neuropathy may be improved quickly after proper phosphate replacement. Phosphate depletion has been corrected using potassium-phosphate infusion, a treatment that can restore consciousness. In severe ataxia and tetra paresis, complete recovery can occur after adequate replacement of phosphate. Patients with multiple risk factors, often with a chronic disease and severe HP that contribute to phosphate depletion, are at risk for neurologic alterations. To predict both risk and optimal phosphate replenishment requires assessing the nutritional status and risk for re-feeding hypophosphatemia. The strategy for correcting HP depends on the severity of the underlying disease and the goal for re-establishing a phosphate balance to limit the consequences of phosphate depletion.

  7. Dark hydrogen fermentations

    NARCIS (Netherlands)

    Vrije, de G.J.; Claassen, P.A.M.

    2003-01-01

    The production of hydrogen is a ubiquitous, natural phenomenon under anoxic or anaerobic conditions. A wide variety of bacteria, in swamps, sewage, hot springs, the rumen of cattle etc. is able to convert organic matter to hydrogen, CO2 and metabolites like acetic acid, lactate, ethanol and alanine.

  8. Travel with hydrogen

    Science.gov (United States)

    Hermans, L. J. F. Jo

    2017-03-01

    In the field of transportation, hydrogen does not have a particularly glorious history. Just think of the dozens of hydrogen airships destroyed by fire over the years, with the Hindenburg disaster in 1937 as the most famous example. Now H2 is trying a comeback on the road, often in combination with a fuel cell and an electric motor to power the car.

  9. Hydrogen Storage Tank

    CERN Multimedia

    1983-01-01

    This huge stainless steel reservoir,placed near an end of the East Hall, was part of the safety equipment connected to the 2 Metre liquid hydrogen Bubble Chamber. It could store all the hydrogen in case of an emergency. The picture shows the start of its demolition.

  10. Thick film hydrogen sensor

    Science.gov (United States)

    Hoffheins, Barbara S.; Lauf, Robert J.

    1995-01-01

    A thick film hydrogen sensor element includes an essentially inert, electrically-insulating substrate having deposited thereon a thick film metallization forming at least two resistors. The metallization is a sintered composition of Pd and a sinterable binder such as glass frit. An essentially inert, electrically insulating, hydrogen impermeable passivation layer covers at least one of the resistors.

  11. Conductive dense hydrogen.

    Science.gov (United States)

    Eremets, M I; Troyan, I A

    2011-11-13

    Molecular hydrogen is expected to exhibit metallic properties under megabar pressures. This metal is predicted to be superconducting with a very high critical temperature, T(c), of 200-400 K, and it may acquire a new quantum state as a metallic superfluid and a superconducting superfluid. It may potentially be recovered metastably at ambient pressures. However, experiments carried out at low temperatures, Thydrogen remains in the molecular insulating state. Here we report on the transformation of normal molecular hydrogen at room temperature (295 K) to a conductive and metallic state. At 200 GPa the Raman frequency of the molecular vibron strongly decreased and the spectral width increased, evidencing a strong interaction between molecules. Deuterium behaved similarly. Above 220 GPa, hydrogen became opaque and electrically conductive. At 260-270 GPa, hydrogen transformed into a metal as the conductance of hydrogen sharply increased and changed little on further pressurizing up to 300 GPa or cooling to at least 30 K; and the sample reflected light well. The metallic phase transformed back at 295 K into molecular hydrogen at 200 GPa. This significant hysteresis indicates that the transformation of molecular hydrogen into a metal is accompanied by a first-order structural transition presumably into a monatomic liquid state. Our findings open an avenue for detailed and comprehensive studies of metallic hydrogen.

  12. Dark hydrogen fermentations

    NARCIS (Netherlands)

    Vrije, de G.J.; Claassen, P.A.M.

    2003-01-01

    The production of hydrogen is a ubiquitous, natural phenomenon under anoxic or anaerobic conditions. A wide variety of bacteria, in swamps, sewage, hot springs, the rumen of cattle etc. is able to convert organic matter to hydrogen, CO2 and metabolites like acetic acid, lactate, ethanol and alanine.

  13. Capturing phosphates with iron enhanced sand filtration.

    Science.gov (United States)

    Erickson, Andrew J; Gulliver, John S; Weiss, Peter T

    2012-06-01

    Most treatment practices for urban runoff capture pollutants such as phosphorus by either settling or filtration while dissolved phosphorus, typically as phosphates, is untreated. Dissolved phosphorus, however, represents an average 45% of total phosphorus in stormwater runoff and can be more than 95%. In this study, a new stormwater treatment technology to capture phosphate, called the Minnesota Filter, is introduced. The filter comprises iron filings mixed with sand and is tested for phosphate removal from synthetic stormwater. Results indicate that sand mixed with 5% iron filings captures an average of 88% phosphate for at least 200 m of treated depth, which is significantly greater than a sand filter without iron filings. Neither incorporation of iron filings into a sand filter nor capture of phosphates onto iron filings in column experiments had a significant effect on the hydraulic conductivity of the filter at mixtures of 5% or less iron by weight. Field applications with up to 10.7% iron were operated over 1 year without detrimental effects upon hydraulic conductivity. A model is applied and fit to column studies to predict the field performance of iron-enhanced sand filters. The model predictions are verified through the predicted performance of the filters in removing phosphates in field applications. Practical applications of the technology, both existing and proposed, are presented so stormwater managers can begin implementation.

  14. The evolution of the marine phosphate reservoir.

    Science.gov (United States)

    Planavsky, Noah J; Rouxel, Olivier J; Bekker, Andrey; Lalonde, Stefan V; Konhauser, Kurt O; Reinhard, Christopher T; Lyons, Timothy W

    2010-10-28

    Phosphorus is a biolimiting nutrient that has an important role in regulating the burial of organic matter and the redox state of the ocean-atmosphere system. The ratio of phosphorus to iron in iron-oxide-rich sedimentary rocks can be used to track dissolved phosphate concentrations if the dissolved silica concentration of sea water is estimated. Here we present iron and phosphorus concentration ratios from distal hydrothermal sediments and iron formations through time to study the evolution of the marine phosphate reservoir. The data suggest that phosphate concentrations have been relatively constant over the Phanerozoic eon, the past 542 million years (Myr) of Earth's history. In contrast, phosphate concentrations seem to have been elevated in Precambrian oceans. Specifically, there is a peak in phosphorus-to-iron ratios in Neoproterozoic iron formations dating from ∼750 to ∼635 Myr ago, indicating unusually high dissolved phosphate concentrations in the aftermath of widespread, low-latitude 'snowball Earth' glaciations. An enhanced postglacial phosphate flux would have caused high rates of primary productivity and organic carbon burial and a transition to more oxidizing conditions in the ocean and atmosphere. The snowball Earth glaciations and Neoproterozoic oxidation are both suggested as triggers for the evolution and radiation of metazoans. We propose that these two factors are intimately linked; a glacially induced nutrient surplus could have led to an increase in atmospheric oxygen, paving the way for the rise of metazoan life.

  15. Effects of inositol phosphates on mineral utilization

    Energy Technology Data Exchange (ETDEWEB)

    Tao, S.H.; Fox, M.R.S.; Phillippy, B.Q.; Fry, B.E. Jr.; Johnson, M.L.; Johnston, M.R.

    1986-03-05

    The present study was designed to compare the effects of inositol tri-, tetra-, and pentaphosphate (IP3, IP4, and IP5) with those of phytic acid (IP6) on growth, development and mineral utilization of young quail. Day-old Japanese quail were fed a purified casein-gelatin control diet containing 20 ppm Zn with 0 or 8.33 mmoles/kg of each inositol phosphate, corresponding to 0.55% of IP6, for a week. As compared with controls, IP6 caused reduced body weight, poor feathering, severe perosis, decreased tibia Zn and ash, and decreased pancreas Zn and liver Mn. IP5 produced all the same adverse effects and tissue mineral changes as those by phytic acid, whereas birds fed IP3 or IP4 were normal. Moreover, IP3 and IP4 caused an increased tibia weight and ash. None of the above effects was produced by feeding inositol or inorganic phosphate. In a second experiment, the inositol phosphates were fed at either 8.33 or 16.66 mmoles/kg diet. Doubling inositol phosphate levels resulted in similar effects as those observed previously. Additionally, IP4 decreased pancreas Zn and IP3 increased tibia Zn. These results indicate that unlike IP6 and IP5, inositol phosphates with 4 or fewer phosphate groups, which can arise from hydrolysis of phytic acid during food processing, have very minor adverse effects but may be beneficial for bone mineralization.

  16. Maize endophytic bacteria as mineral phosphate solubilizers.

    Science.gov (United States)

    de Abreu, C S; Figueiredo, J E F; Oliveira, C A; Dos Santos, V L; Gomes, E A; Ribeiro, V P; Barros, B A; Lana, U G P; Marriel, I E

    2017-02-16

    In the present study, we demonstrated the in vitro activity of endophytic phosphate-solubilizing bacteria (PSB). Fifty-five endophytic PSB that were isolated from sap, leaves, and roots of maize were tested for their ability to solubilize tricalcium phosphate and produce organic acid. Partial sequencing of the 16S rRNA-encoding gene showed that the isolates were from the genus Bacillus and different species of Enterobacteriaceae. The phosphate solubilization index on solid medium and phosphate solubilization in liquid medium varied significantly among the isolates. There was a statistically significant difference (P ≤ 0.05) for both, the values of phosphate-solubilizing activity and pH of the growth medium, among the isolates. Pearson correlation was statistically significant (P ≤ 0.05) between P-solubilization and pH (R = -0.38), and between the gluconic acid production and the lowering of the pH of the liquid medium at 6 (R = 0.28) and 9 days (R = 0.39). Gluconic acid production was prevalent in all the PSB studied, and Bacillus species were most efficient in solubilizing phosphate. This is the first report on the characterization of bacterial endophytes from maize and their use as potential biofertilizers. In addition, this may provide an alternative strategy for improving the phosphorus acquisition efficiency of crop plants in tropical soils.

  17. Crystal structure of 3,4-dihydroxy-2-butanone 4-phosphate synthase of riboflavin biosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Liao, D.-I.; Calabrese, J.C.; Wawrzak, Z.; Viitanen, P.V.; Jordan, D.B. (DuPont); (NWU)

    2010-03-05

    3,4-Dihydroxy-2-butanone-4-phosphate synthase catalyzes a commitment step in the biosynthesis of riboflavin. On the enzyme, ribulose 5-phosphate is converted to 3,4-dihydroxy-2-butanone 4-phosphate and formate in steps involving enolization, ketonization, dehydration, skeleton rearrangement, and formate elimination. The enzyme is absent in humans and an attractive target for the discovery of antimicrobials for pathogens incapable of acquiring sufficient riboflavin from their hosts. The homodimer of 23 kDa subunits requires Mg{sup 2+} for activity. The first three-dimensional structure of the enzyme was determined at 1.4 {angstrom} resolution using the multiwavelength anomalous diffraction (MAD) method on Escherichia coli protein crystals containing gold. The protein consists of an {alpha} + {beta} fold having a complex linkage of {beta} strands. Intersubunit contacts are mediated by numerous hydrophobic interactions and three hydrogen bond networks. A proposed active site was identified on the basis of amino acid residues that are conserved among the enzyme from 19 species. There are two well-separated active sites per dimer, each of which comprise residues from both subunits. In addition to three arginines and two threonines, which may be used for recognizing the phosphate group of the substrate, the active site consists of three glutamates, two aspartates, two histidines, and a cysteine which may provide the means for general acid and base catalysis and for coordinating the Mg{sup 2+} cofactor within the active site.

  18. Silver di-t-butyl phosphate, a useful reagent in the synthesis of phospholipids. Synthesis of mixed-acid phosphatidic acid and phosphatidyl glycerolphosphate

    NARCIS (Netherlands)

    Bonsen, P.P.M.; Haas, Gerard H. de

    1967-01-01

    The synthesis of silver di-t-butyl phosphate is described. Using this reagent, mixed-acid phosphatidic acid with one unsaturated fatty acid could be prepared by means of a reaction with a 1,2-diacyl glycerol-3-iodohydrin. The blocking groups could be removed easily with dry hydrogen chloride at low

  19. Hydrogen Fuel Quality

    Energy Technology Data Exchange (ETDEWEB)

    Rockward, Tommy [Los Alamos National Laboratory

    2012-07-16

    For the past 6 years, open discussions and/or meetings have been held and are still on-going with OEM, Hydrogen Suppliers, other test facilities from the North America Team and International collaborators regarding experimental results, fuel clean-up cost, modeling, and analytical techniques to help determine levels of constituents for the development of an international standard for hydrogen fuel quality (ISO TC197 WG-12). Significant progress has been made. The process for the fuel standard is entering final stages as a result of the technical accomplishments. The objectives are to: (1) Determine the allowable levels of hydrogen fuel contaminants in support of the development of science-based international standards for hydrogen fuel quality (ISO TC197 WG-12); and (2) Validate the ASTM test method for determining low levels of non-hydrogen constituents.

  20. Electrochemical Hydrogen Compressor

    Energy Technology Data Exchange (ETDEWEB)

    Lipp, Ludwig [FuelCell Energy, Inc., Torrington, CT (United States)

    2016-01-21

    Conventional compressors have not been able to meet DOE targets for hydrogen refueling stations. They suffer from high capital cost, poor reliability and pose a risk of fuel contamination from lubricant oils. This project has significantly advanced the development of solid state hydrogen compressor technology for multiple applications. The project has achieved all of its major objectives. It has demonstrated capability of Electrochemical Hydrogen Compression (EHC) technology to potentially meet the DOE targets for small compressors for refueling sites. It has quantified EHC cell performance and durability, including single stage hydrogen compression from near-atmospheric pressure to 12,800 psi and operation of EHC for more than 22,000 hours. Capital cost of EHC was reduced by 60%, enabling a path to meeting the DOE cost targets for hydrogen compression, storage and delivery ($2.00-2.15/gge by 2020).

  1. Implementing a hydrogen economy

    Directory of Open Access Journals (Sweden)

    James A Ritter

    2003-09-01

    In recent years, months, weeks, and even days, it has become increasingly clear that hydrogen as an energy carrier is ‘in’ and carbonaceous fuels are ‘out’1. The hydrogen economy is coming, with the impetus to transform our fossil energy-based society, which inevitably will cease to exist, into a renewable energy-based one2. However, this transformation will not occur overnight. It may take several decades to realize a hydrogen economy. In the meantime, research and development is necessary to ensure that the implementation of the hydrogen economy is completely seamless, with essentially no disruption of the day-to-day activities of the global economy. The world has taken on a monumental, but not insurmountable, task of transforming from carbonaceous to renewable fuels, with clean burning, carbon dioxide-free hydrogen as the logical choice.

  2. Hydrogen Peroxide Concentrator

    Science.gov (United States)

    Parrish, Clyde F.

    2007-01-01

    A relatively simple and economical process and apparatus for concentrating hydrogen peroxide from aqueous solution at the point of use have been invented. The heart of the apparatus is a vessel comprising an outer shell containing tubular membranes made of a polymer that is significantly more permeable by water than by hydrogen peroxide. The aqueous solution of hydrogen peroxide to be concentrated is fed through the interstitial spaces between the tubular membranes. An initially dry sweep gas is pumped through the interiors of the tubular membranes. Water diffuses through the membranes and is carried away as water vapor mixed into the sweep gas. Because of the removal of water, the hydrogen peroxide solution flowing from the vessel at the outlet end is more concentrated than that fed into the vessel at the inlet end. The sweep gas can be air, nitrogen, or any other gas that can be conveniently supplied in dry form and does not react chemically with hydrogen peroxide.

  3. A new human NHERF1 mutation decreases renal phosphate transporter NPT2a expression by a PTH-independent mechanism.

    Directory of Open Access Journals (Sweden)

    Marie Courbebaisse

    Full Text Available BACKGROUND: The sodium-hydrogen exchanger regulatory factor 1 (NHERF1 binds to the main renal phosphate transporter NPT2a and to the parathyroid hormone (PTH receptor. We have recently identified mutations in NHERF1 that decrease renal phosphate reabsorption by increasing PTH-induced cAMP production in the renal proximal tubule. METHODS: We compared relevant parameters of phosphate homeostasis in a patient with a previously undescribed mutation in NHERF1 and in control subjects. We expressed the mutant NHERF1 protein in Xenopus Oocytes and in cultured cells to study its effects on phosphate transport and PTH-induced cAMP production. RESULTS: We identified in a patient with inappropriate renal phosphate reabsorption a previously unidentified mutation (E68A located in the PDZ1 domain of NHERF1.We report the consequences of this mutation on NHERF1 function. E68A mutation did not modify cAMP production in the patient. PTH-induced cAMP synthesis and PKC activity were not altered by E68A mutation in renal cells in culture. In contrast to wild-type NHERF1, expression of the E68A mutant in Xenopus oocytes and in human cells failed to increase phosphate transport. Pull down experiments showed that E68A mutant did not interact with NPT2a, which robustly interacted with wild type NHERF1 and previously identified mutants. Biotinylation studies revealed that E68A mutant was unable to increase cell surface expression of NPT2a. CONCLUSIONS: Our results indicate that the PDZ1 domain is critical for NHERF1-NPT2a interaction in humans and for the control of NPT2a expression at the plasma membrane. Thus we have identified a new mechanism of renal phosphate loss and shown that different mutations in NHERF1 can alter renal phosphate reabsorption via distinct mechanisms.

  4. Effect of the calcium to phosphate ratio of tetracalcium phosphate on the properties of calcium phosphate bone cement.

    Science.gov (United States)

    Burguera, Elena F; Guitian, Francisco; Chow, Laurence C

    2008-06-01

    Six different tetracalcium phosphate (TTCP) products were synthesized by solid state reaction at high temperature by varying the overall calcium to phosphate ratio of the synthesis mixture. The objective was to evaluate the effect of the calcium to phosphate ratio on a TTCP-dicalcium phosphate dihydrate (DCPD) cement. The resulting six TTCP-DCPD cement mixtures were characterized using X-ray diffraction analysis, scanning electron microscopy, and pH measurements. Setting times and compressive strength (CS) were also measured. Using the TTCP product with a Ca/P ratio of 2.0 resulted in low strength values (25.61 MPa) when distilled water was used as the setting liquid, even though conversion to hydroxyapatite was not prevented, as confirmed by X-ray diffraction. The suspected CaO presence in this TTCP may have affected the cohesiveness of the cement mixture but not the cement setting reaction, however no direct evidence of CaO presence was found. Lower Ca/P ratio products yielded cements with CS values ranging from 46.7 MPa for Ca/P ratio of 1.90 to 38.32 MPa for Ca/P ratio of 1.85. When a dilute sodium phosphate solution was used as the setting liquid, CS values were 15.3% lower than those obtained with water as the setting liquid. Setting times ranged from 18 to 22 min when water was the cement liquid and from 7 to 8 min when sodium phosphate solution was used, and the calcium to phosphate ratio did not have a marked effect on this property.

  5. Nature-Inspired Design of Artificial Solar-to-Fuel Conversion Systems based on Copper Phosphate Microflowers.

    Science.gov (United States)

    Wang, Jing; Zhu, Ting; Ho, Ghim Wei

    2016-07-07

    Phosphates play significant roles in plant photosynthesis by mediating electron transportation and furnishing energy for CO2 reduction. Motivated by this, we demonstrate herein an artificial solar-to-fuel conversion system, involving versatile copper phosphate microflowers as template and titanium dioxide nanoparticles as host photocatalyst. The elaborate flowerlike architectures, coupled with a unique proton-reduction cycle from interchangeability of different species of orthophosphate ions, not only offer a 2D nanosheet platform for an optimal heterostructure interface but also effectively augment charge-carrier transfer, thereby contributing to enhanced photoactivity and hydrogen generation. These nature-inspired, phosphate-derived nanocomposites advance the synthesis of a large variety of functional materials, which holds great potential for photochemical, photoelectric and catalytic applications.

  6. Effective removal of methyl blue by fine-structured strontium and barium phosphate nanorods

    Science.gov (United States)

    Zhang, Fan; Song, Weijie; Lan, Jing

    2015-01-01

    In this work, the composite of strontium phosphate and barium phosphate (called SBP) nanorods have been synthesized, characterized and studied for removal of methyl blue (MB). The effects of pH, temperature, contact time, initial dye concentration on removal of MB were studied in detail. Results suggest that pH and temperature were not critical limiting factors for the removal of MB. Reaching equilibrium was very rapid (within 10 min) and the high adsorption capacity of MB by SBP nanorods was 1691.8 mg/g at initial dye concentration of 2000 mg/L. The adsorption process obeyed the pseudo-second-order kinetics model and Langmuir isotherm model. Importantly, the mechanism contributed to the MB removal was proposed to be the ionic interaction and hydrogen bonds for low dye concentration, chemical precipitation for high dye concentration. It is predicted that the SBP nanorods being an effective adsorbent for elimination of MB from colored aqueous solutions.

  7. Injectable Hydrogel Composite Based Gelatin-PEG and Biphasic Calcium Phosphate Nanoparticles for Bone Regeneration

    Science.gov (United States)

    Van, Thuy Duong; Tran, Ngoc Quyen; Nguyen, Dai Hai; Nguyen, Cuu Khoa; Tran, Dai Lam; Nguyen, Phuong Thi

    2016-05-01

    Gelatin hydrogels have recently attracted much attention for tissue regeneration because of their biocompatibility. In this study, we introduce poly-ethylene glycol (PEG)—grafted gelatin containing tyramine moieties which have been utilized for in situ enzyme-mediated hydrogel preparation. The hydrogel can be used to load nanoparticles of biphasic calcium phosphate, a mixture of hydroxyapatite and β-tricalcium phosphate, and forming injectable bio-composites. Proton nuclear magnetic resonance (1H NMR) spectra indicated that tyramine-functionalized polyethylene glycol-nitrophenyl carbonate ester was conjugated to the gelatin. The hydrogel composite was rapidly formed in situ (within a few seconds) in the presence of horseradish peroxidase and hydrogen peroxide. In vitro experiments with bio-mineralization on the hydrogel composite surfaces was well-observed after 2 weeks soaking in simulated body fluid solution. The obtained results indicated that the hydrogel composite could be a potential injectable material for bone regeneration.

  8. Polarographic Studies on Associations of Midecamycin and Chloroquine with Hydrogen Peroxide

    Institute of Scientific and Technical Information of China (English)

    LI Ning; SONG Jun-feng; XU Mao-tian; ZHANG Ya

    2005-01-01

    The associations of each of midecamycin and chloroquine phosphate to hydrogen peroxide were studied by using linear-potential scan polarography. In a 0.15 mol/L KH2PO4-NaOH(pH 7.4) buffer, the association ratio of the association complex of midecamycin to hydrogen peroxide is 1∶1, and the apparent association constant is 7.18. While in a 0.04 mol/L NH3·H2O-NH4Cl(pH 9.5) buffer, the association ratio and the apparent association constant of the association complex of chloroquine phosphate to hydrogen peroxide are 1∶1 and 45.4, respectively. The formation of the association complexes stabilizes H2O2 and results in the accumulation of H2O2, which is baneful to human body.

  9. Photoelectrochemical hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Rocheleau, R.; Misra, A.; Miller, E. [Univ. of Hawaii, Honolulu, HI (United States)

    1998-08-01

    A significant component of the US DOE Hydrogen Program is the development of a practical technology for the direct production of hydrogen using a renewable source of energy. High efficiency photoelectrochemical systems to produce hydrogen directly from water using sunlight as the energy source represent one of the technologies identified by DOE to meet this mission. Reactor modeling and experiments conducted at UH provide strong evidence that direct solar-to-hydrogen conversion efficiency greater than 10% can be expected using photoelectrodes fabricated from low-cost, multijunction (MJ) amorphous silicon solar cells. Solar-to-hydrogen conversion efficiencies as high as 7.8% have been achieved using a 10.3% efficient MJ amorphous silicon solar cell. Higher efficiency can be expected with the use of higher efficiency solar cells, further improvement of the thin film oxidation and reduction catalysts, and optimization of the solar cell for hydrogen production rather than electricity production. Hydrogen and oxygen catalysts developed under this project are very stable, exhibiting no measurable degradation in KOH after over 13,000 hours of operation. Additional research is needed to fully optimize the transparent, conducting coatings which will be needed for large area integrated arrays. To date, the best protection has been afforded by wide bandgap amorphous silicon carbide films.

  10. Biological Removal of Phosphate Using Phosphate Solubilizing Bacterial Consortium from Synthetic Wastewater: A Laboratory Scale

    Directory of Open Access Journals (Sweden)

    Dipak Paul

    2015-01-01

    Full Text Available Biological phosphate removal is an important process having gained worldwide attention and widely used for removing phosphorus from wastewater. The present investigation was aimed to screen the efficient phosphate solubilizing bacterial isolates and used to remove phosphate from synthetic wastewater under shaking flasks conditions. Pseudomonas sp. JPSB12, Enterobacter sp. TPSB20, Flavobacterium sp. TPSB23 and mixed bacterial consortium (Pseudomonas sp. JPSB12+Enterobacter sp. TPSB20+Flavobacterium sp. TPSB23 were used for the removal of phosphate. Among the individual strains, Enterobacter sp. TPSB20 was removed maximum phosphate (61.75% from synthetic wastewater in presence of glucose as a carbon source. The consortium was effectively removed phosphate (74.15-82.50% in the synthetic wastewater when compared to individual strains. The pH changes in culture medium with time and extracellular phosphatase activity (acid and alkaline were also investigated. The efficient removal of phosphate by the consortium may be due to the synergistic activity among the individual strains and phosphatase enzyme activity. The use of bacterial consortium in the remediation of phosphate contaminated aquatic environments has been discussed.

  11. Translocation of metal phosphate via the phosphate inorganic transport system of Escherichia coli

    NARCIS (Netherlands)

    van Veen, H.W; Abee, T.; Kortstee, G.J J; Konings, W.N; Zehnder, A.J B

    1994-01-01

    P-i transport via the phosphate inorganic transport system (Pit) of Escherichia coil was studied in natural and artificial membranes. P-i uptake via Pit is dependent on the presence of divalent cations, like Mg2+, Ca2+, Co2+, or Mn2+, which form a soluble, neutral metal phosphate (MeHPO(4)) complex.

  12. Inside the Hydrogen Atom

    CERN Document Server

    Nowakowski, M; Fierro, D Bedoya; Manjarres, A D Bermudez

    2016-01-01

    We apply the non-linear Euler-Heisenberg theory to calculate the electric field inside the hydrogen atom. We will demonstrate that the electric field calculated in the Euler-Heisenberg theory can be much smaller than the corresponding field emerging from the Maxwellian theory. In the hydrogen atom this happens only at very small distances. This effect reduces the large electric field inside the hydrogen atom calculated from the electromagnetic form-factors via the Maxwell equations. The energy content of the field is below the pair production threshold.

  13. Color Changing Hydrogen Sensors

    Science.gov (United States)

    Roberson, Luke B.; Williams, Martha; Captain, Janine E.; Mohajeri, Nahid; Raissi, Ali

    2015-01-01

    During the Space Shuttle Program, one of the most hazardous operation that occurred was the loading of liquid hydrogen (LH2) during fueling operations of the spacecraft. Due to hydrogen's low explosive limit, any amount leaked could lead to catastrophic event. Hydrogen's chemical properties make it ideal as a rocket fuel; however, the fuel is deemed unsafe for most commercial use because of the inability to easily detect the gas leaking. The increased use of hydrogen over traditional fossil fuels would reduce greenhouse gases and America's dependency on foreign oil. Therefore a technology that would improve safety at NASA and in the commercial sector while creating a new economic sector would have a huge impact to NASA's mission. The Chemochromic Detector for sensing hydrogen gas leakage is a color-changing detector that is useful in any application where it is important to know not only the presence but also the location of the hydrogen gas leak. This technology utilizes a chemochromicpigment and polymer matrix that can be molded or spun into rigid or pliable shapes useable in variable temperature environments including atmospheres of inert gas, hydrogen gas, or mixtures of gases. A change in color of the detector material indicates where gaseous hydrogen leaks are occurring. The irreversible sensor has a dramatic color change from beige to dark grey and remains dark grey after exposure. A reversible pigment changes from white to blue in the presence of hydrogen and reverts back to white in the presence of oxygen. Both versions of the sensor's pigments were comprised of a mixture of a metal oxide substrate and a hydro-chromic compound (i.e., the compound that changed color in the presence of hydrogen) and immediately notified the operator of the presence of low levels of hydrogen. The detector can be used in a variety of formats including paint, tape, caulking, injection molded parts, textiles and fabrics, composites, and films. This technology brings numerous

  14. Biological hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Benemann, J.R. [Univ. of California, Berkeley, CA (United States)

    1995-11-01

    Biological hydrogen production can be accomplished by either thermochemical (gasification) conversion of woody biomass and agricultural residues or by microbiological processes that yield hydrogen gas from organic wastes or water. Biomass gasification is a well established technology; however, the synthesis gas produced, a mixture of CO and H{sub 2}, requires a shift reaction to convert the CO to H{sub 2}. Microbiological processes can carry out this reaction more efficiently than conventional catalysts, and may be more appropriate for the relatively small-scale of biomass gasification processes. Development of a microbial shift reaction may be a near-term practical application of microbial hydrogen production.

  15. A Hydrogen Utopia?

    Energy Technology Data Exchange (ETDEWEB)

    Cherry, Robert Stephen; Reynolds, Bruce Allen

    2004-01-01

    The use of hydrogen as a fuel for transportation and stationary applications is receiving much favorable attention as a technical and policy issue. However, the widespread introduction of this technology is likely also to have negative consequences that are not being actively discussed in broad public forums. Such possibilities include, among others, delayed development of other energy alternatives, hazards of catalyst or hydride metals, disruptive employment shifts, land usage conflicts, and increased vehicle usage. Even though hydrogen is likely to be beneficial in its overall societal and environmental effects, hydrogen technology advocates must understand the range of problematic issues and prepare to address them.

  16. A hydrogen utopia?

    Energy Technology Data Exchange (ETDEWEB)

    Cherry, Robert S. [National Academy of Engineering, Washington, DC (United States)

    2004-02-01

    The use of hydrogen as a fuel for transportation and stationary applications is receiving much favorable attention as a technical and policy issue. However, the widespread introduction of this technology is likely also to have negative consequences that are not being actively discussed in broad public forums. Such possibilities include, among others, delayed development of other energy alternatives, hazards of catalyst or hydride metals, disruptive employment shifts, land usage conflicts, and increased vehicle usage. Even though hydrogen is likely to be beneficial in its overall societal and environmental effects, hydrogen technology advocates must understand the range of problematic issues and prepare to address them. (Author)

  17. National hydrogen energy roadmap

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2002-11-01

    This report was unveiled by Energy Secretary Spencer Abraham in November 2002 and provides a blueprint for the coordinated, long-term, public and private efforts required for hydrogen energy development. Based on the results of the government-industry National Hydrogen Energy Roadmap Workshop, held in Washington, DC on April 2-3, 2002, it displays the development of a roadmap for America's clean energy future and outlines the key barriers and needs to achieve the hydrogen vision goals defined in

  18. Cloning and characterization of a glucose 6-phosphate/phosphate translocator from Oryza sativa

    Institute of Scientific and Technical Information of China (English)

    姜华武; 佃蔚敏; 刘非燕; 吴平

    2003-01-01

    Plastids of nongreen tissues import carbon as a source of biosynthetic pathways and energy, and glucose 6-phosphate is the preferred hexose phosphate taken up by nongreen plastids. A cDNA clone encoding glucose 6-phosphate/phosphate translocator (GPT) was isolated from a cDNA library of immature seeds of rice and named as OsGPT. The cDNA has one uninterrupted open reading frame encoding a 42 kDa polypeptide possessing transit peptide consisting of 70 amino acid residues. The OsGPT gene maps on chromosome 8 of rice and is linked to the quantitative trait locus for 1000-grain weight. The expression of OsGPT is mainly restricted to heterotrophic tissues. These results suggest that glucose 6-phosphate imported via GPT can be used for starch biosynthesis in rice nongreen plastids.

  19. Solid state 31NMR studies of the conversion of amorphous tricalcium phosphate to apatitic tricalcium phosphate.

    Science.gov (United States)

    Roberts, J E; Heughebaert, M; Heughebaert, J C; Bonar, L C; Glimcher, M J; Griffin, R G

    1991-12-01

    The hydrolytic conversion of a solid amorphous calcium phosphate of empirical formula Ca9 (PO4)6 to a poorly crystalline apatitic phase, under conditions where Ca2+ and PO4(3-) were conserved, was studied by means of solid-state magic-angle sample spinning 31P-NMR (nuclear magnetic resonance). Results showed a gradual decrease in hydrated amorphous calcium phosphate and the formation of two new PO4(3-)-containing components: an apatitic component similar to poorly crystalline hydroxyapatite and a protonated PO4(3-), probably HPO4(2-) in a dicalcium phosphate dihydrate (DCPD) brushite-like configuration. This latter component resembles the brushite-like HPO4(2-) component previously observed by 31P-NMR in apatitic calcium phosphates of biological origin. Results were consistent with previous studies by Heughebaert and Montel [18] of the kinetics of the conversion of amorphous calcium phosphate to hydroxyapatite under the same conditions.

  20. Biomimetic hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Krassen, Henning

    2009-05-15

    Hydrogenases catalyze the reduction of protons to molecular hydrogen with outstanding efficiency. An electrode surface which is covered with active hydrogenase molecules becomes a promising alternative to platinum for electrochemical hydrogen production. To immobilize the hydrogenase on the electrode, the gold surface was modified by heterobifunctional molecules. A thiol headgroup on one side allowed the binding to the gold surface and the formation of a self-assembled monolayer. The other side of the molecules provided a surface with a high affinity for the hydrogenase CrHydA1 from Chlamydomonas reinhardtii. With methylviologen as a soluble energy carrier, electrons were transferred from carboxy-terminated electrodes to CrHydA1 and conducted to the active site (H-cluster), where they reduce protons to molecular hydrogen. A combined approach of surface-enhanced infrared absorption spectroscopy, gas chromatography, and surface plasmon resonance allowed quantifying the hydrogen production on a molecular level. Hydrogen was produced with a rate of 85 mol H{sub 2} min{sup -1} mol{sup -1}. On a 1'- benzyl-4,4'-bipyridinum (BBP)-terminated surface, the electrons were mediated by the monolayer and no soluble electron carrier was necessary to achieve a comparable hydrogen production rate (approximately 50% of the former system). The hydrogen evolution potential was determined to be -335 mV for the BBP-bound hydrogenase and -290 mV for the hydrogenase which was immobilized on a carboxy-terminated mercaptopropionic acid SAM. Therefore, both systems significantly reduce the hydrogen production overpotential and allow electrochemical hydrogen production at an energy level which is close to the commercially applied platinum electrodes (hydrogen evolution potential of -270 mV). In order to couple hydrogen production and photosynthesis, photosystem I (PS1) from Synechocystis PCC 6803 and membrane-bound hydrogenase (MBH) from Ralstonia eutropha were bound to each other

  1. Sodium phosphate as an ergogenic aid.

    Science.gov (United States)

    Buck, Christopher L; Wallman, Karen E; Dawson, Brian; Guelfi, Kym J

    2013-06-01

    Legal nutritional ergogenic aids can offer athletes an additional avenue to enhance their performance beyond what they can achieve through training. Consequently, the investigation of new nutritional ergogenic aids is constantly being undertaken. One emerging nutritional supplement that has shown some positive benefits for sporting performance is sodium phosphate. For ergogenic purposes, sodium phosphate is supplemented orally in capsule form, at a dose of 3-5 g/day for a period of between 3 and 6 days. A number of exercise performance-enhancing alterations have been reported to occur with sodium phosphate supplementation, which include an increased aerobic capacity, increased peak power output, increased anaerobic threshold and improved myocardial and cardiovascular responses to exercise. A range of mechanisms have been posited to account for these ergogenic effects. These include enhancements in 2,3-Diphosphoglycerate (2,3-DPG) concentrations, myocardial efficiency, buffering capacity and adenosine triphosphate/phosphocreatine synthesis. Whilst there is evidence to support the ergogenic benefits of sodium phosphate, many studies researching this substance differ in terms of the administered dose and dosing protocol, the washout period employed and the fitness level of the participants recruited. Additionally, the effect of gender has received very little attention in the literature. Therefore, the purpose of this review is to critically examine the use of sodium phosphate as an ergogenic aid, with a focus on identifying relevant further research.

  2. Sodium ascorbyl phosphate in topical microemulsions.

    Science.gov (United States)

    Spiclin, Polona; Homar, Miha; Zupancic-Valant, Andreja; Gasperlin, Mirjana

    2003-04-30

    Sodium ascorbyl phosphate is a hydrophilic derivative of ascorbic acid, which has improved stability arising from its chemical structure. It is used in cosmetic and pharmaceutical preparations since it has many favorable effects in the skin, the most important being antioxidant action. In order to achieve this, it has to be converted into free ascorbic acid by enzymatic degradation in the skin. In the present work, o/w and w/o microemulsions composed of the same ingredients, were selected as carrier systems for topical delivery of sodium ascorbyl phosphate. We showed that sodium ascorbyl phosphate was stable in both types of microemulsion with no significant influence of its location in the carrier system. To obtain liquid microemulsions appropriate for topical application, their viscosity was increased by adding thickening agents. On the basis of rheological characterization, 4.00% (m/m) colloidal silica was chosen as a suitable thickening agent for w/o microemulsions and 0.50% (m/m) xanthan gum for the o/w type. The presence of thickening agent and the location of sodium ascorbyl phosphate in the microemulsion influenced the in vitro drug release profiles. When incorporated in the internal aqueous phase, sustained release profiles were observed. This study confirmed microemulsions as suitable carrier systems for topical application of sodium ascorbyl phosphate.

  3. Synthesis and crystal structure of 4-fluorobenzylammonium dihydrogen phosphate, [FC6H4CH2NH3]H2PO4

    Directory of Open Access Journals (Sweden)

    Ali Rayes

    2016-12-01

    Full Text Available The asymmetric unit of the title salt, [p-FC6H4CH2NH3]+·H2PO4−, contains one 4-fluorobenzylammonium cation and one dihydrogen phosphate anion. In the crystal, the H2PO4− anions are linked by O—H...O hydrogen bonds to build corrugated layers extending parallel to the ab plane. The FC6H4CH2NH3+ cations lie between these anionic layers to maximize the electrostatic interactions and are linked to the H2PO4− anions through N—H...O hydrogen bonds, forming a three-dimensional supramolecular network. Two hydrogen atoms belonging to the dihydrogen phosphate anion are statistically occupied due to disorder along the OH...HO direction.

  4. 1-Diphenyl-phosphino-1'-(diphenyl-phosphinoyl)cobaltocenium hexa-fluorido-phosphate.

    Science.gov (United States)

    Wu, Xiang-Hua; Guo, Rui; Jin, Shan; Yu, Guang-Ao; Liu, Sheng-Hua

    2008-09-06

    The title compound, [Co(C(17)H(14)OP)(C(17)H(14)P)]PF(6), was obtained unintentionally as the product of an attempted synthesis of [1,1'-bis-(oxodiphenyl-phospho-ranyl)cobaltocenium] hexa-fluorido-phosphate. The O atom of the oxo group is disordered over two positions with site occupancies of 0.65:0.35. The crystal structure contains weak inter-molecular C-H⋯F hydrogen bonds, connecting the components of the structure into chains parallel to [010].

  5. Bifunctional Catalysis: Direct Reductive Amination of Aliphatic Ketones with an Iridium-Phosphate Catalyst

    Directory of Open Access Journals (Sweden)

    Barbara Villa-Marcos

    2010-04-01

    Full Text Available Chiral amines are one of the ubiquitous functional groups in fine chemical, pharmaceutical and agrochemical products, and the most convenient, economical, and eco-benign synthetic pathway to these amines is direct asymmetric reductive amination (DARA of prochiral ketones. This paper shows that a wide range of aliphatic ketones can be directly aminated under hydrogenation conditions, affording chiral amines with good to excellent yields and with enantioselectivities up to 96% ee. The catalysis is effected by the cooperative action of a cationic Cp*Ir(III complex and its phosphate counteranion.

  6. Composition of calcium phosphates precipitated from aqueous solutions at different pH values

    Energy Technology Data Exchange (ETDEWEB)

    Salahi, E.; Moztarzadeh, F. [Ceramics Div., Teheran (Iran). Materials and Energy Research Center

    2001-03-01

    During the preparation of calcium phosphate compounds by precipitation from aqueous solutions, several phases, namely dicalcium hydrogen phosphate (DCP, CaHPO{sub 4}), dicalcium hydrogen phosphate dihydrate DCPD, CaHPO{sub 4} (2 H{sub 2}O), hydrated calcium phosphate Ca{sub 3}(PO){sub 4} 2(H{sub 2}O) and hydroxyapatite (HAp, Ca10(PO{sub 4})6(OH){sub 2}), can be formed at different pH values. In the research work presented here, Ca(NO{sub 3})2(4H{sub 2}O) and (NH{sub 4})2HPO{sub 4} were used as starting materials The two solutions with an initial molar ratio of Ca/P=1,67 were mixed at 20 C at 0phosphate are formed. A structural transition was observed at 8phosphate ({beta}-TCP,Ca{sub 3}(PO{sub 4}){sub 2}) developed. Between pH 8 and 9, this phase could be observed clearly. At pH 9..10, there is a transitional state, and at pH >10,5, the hydroxyapatite was developed completely. (orig.)

  7. Hydrogen Recovery System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Rocket test operations at NASA Stennis Space Center (SSC) result in substantial quantities of hydrogen gas that is flared from the facility and helium gas that is...

  8. Hydrogen Recovery System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Liquid hydrogen is used extensively by NASA to support cryogenic rocket testing. In addition, there are many commercial applications in which delivery and use of...

  9. Fiber optic hydrogen sensor

    Energy Technology Data Exchange (ETDEWEB)

    Butler, M.A.; Sanchez, R.; Dulleck, G.R.

    1996-05-01

    This report covers the development of fiber optic hydrogen and temperature sensors for monitoring dissolved hydrogen gas in transformer oil. The concentration of hydrogen gas is a measure of the corona and spark discharge within the transformer and reflects the state of health of the transformer. Key features of the instrument include use of palladium alloys to enhance hydrogen sensitivity, a microprocessor controlled instrument with RS-232, liquid crystal readout, and 4-20 ma. current loop interfaces. Calibration data for both sensors can be down loaded to the instrument through the RS-232 interface. This project was supported by the Technology Transfer Initiative in collaboration with J. W. Harley, Inc. through the mechanism of a cooperative research and development agreement (CRADA).

  10. Interstitial hydrogen storage system

    Energy Technology Data Exchange (ETDEWEB)

    Gell, H.A.

    1980-09-30

    A metal hydride fuel system is described that incorporates a plurality of storage elements that may be individually replaced to provide a hydrogen fuel system for combustion engines having a capability of partial refueling is presented.

  11. Florida Hydrogen Initiative

    Energy Technology Data Exchange (ETDEWEB)

    Block, David L

    2013-06-30

    The Florida Hydrogen Initiative (FHI) was a research, development and demonstration hydrogen and fuel cell program. The FHI program objectives were to develop Florida?s hydrogen and fuel cell infrastructure and to assist DOE in its hydrogen and fuel cell activities The FHI program funded 12 RD&D projects as follows: Hydrogen Refueling Infrastructure and Rental Car Strategies -- L. Lines, Rollins College This project analyzes strategies for Florida's early stage adaptation of hydrogen-powered public transportation. In particular, the report investigates urban and statewide network of refueling stations and the feasibility of establishing a hydrogen rental-car fleet based in Orlando. Methanol Fuel Cell Vehicle Charging Station at Florida Atlantic University ? M. Fuchs, EnerFuel, Inc. The project objectives were to design, and demonstrate a 10 kWnet proton exchange membrane fuel cell stationary power plant operating on methanol, to achieve an electrical energy efficiency of 32% and to demonstrate transient response time of less than 3 milliseconds. Assessment of Public Understanding of the Hydrogen Economy Through Science Center Exhibits, J. Newman, Orlando Science Center The project objective was to design and build an interactive Science Center exhibit called: ?H2Now: the Great Hydrogen Xchange?. On-site Reformation of Diesel Fuel for Hydrogen Fueling Station Applications ? A. Raissi, Florida Solar Energy Center This project developed an on-demand forecourt hydrogen production technology by catalytically converting high-sulfur hydrocarbon fuels to an essentially sulfur-free gas. The removal of sulfur from reformate is critical since most catalysts used for the steam reformation have limited sulfur tolerance. Chemochromic Hydrogen Leak Detectors for Safety Monitoring ? N. Mohajeri and N. Muradov, Florida Solar Energy Center This project developed and demonstrated a cost-effective and highly selective chemochromic (visual) hydrogen leak detector for safety

  12. Photoelectrochemical hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Rocheleau, R.E.; Miller, E.; Misra, A. [Univ. of Hawaii, Honolulu, HI (United States)

    1996-10-01

    The large-scale production of hydrogen utilizing energy provided by a renewable source to split water is one of the most ambitious long-term goals of the U.S. Department of Energy`s Hydrogen Program. One promising option to meet this goal is direct photoelectrolysis in which light absorbed by semiconductor-based photoelectrodes produces electrical power internally to split water into hydrogen and oxygen. Under this program, direct solar-to-chemical conversion efficiencies as high as 7.8 % have been demonstrated using low-cost, amorphous-silicon-based photoelectrodes. Detailed loss analysis models indicate that solar-to-chemical conversion greater than 10% can be achieved with amorphous-silicon-based structures optimized for hydrogen production. In this report, the authors describe the continuing progress in the development of thin-film catalytic/protective coatings, results of outdoor testing, and efforts to develop high efficiency, stable prototype systems.

  13. The hydrogen issue.

    Science.gov (United States)

    Armaroli, Nicola; Balzani, Vincenzo

    2011-01-17

    Hydrogen is often proposed as the fuel of the future, but the transformation from the present fossil fuel economy to a hydrogen economy will need the solution of numerous complex scientific and technological issues, which will require several decades to be accomplished. Hydrogen is not an alternative fuel, but an energy carrier that has to be produced by using energy, starting from hydrogen-rich compounds. Production from gasoline or natural gas does not offer any advantage over the direct use of such fuels. Production from coal by gasification techniques with capture and sequestration of CO₂ could be an interim solution. Water splitting by artificial photosynthesis, photobiological methods based on algae, and high temperatures obtained by nuclear or concentrated solar power plants are promising approaches, but still far from practical applications. In the next decades, the development of the hydrogen economy will most likely rely on water electrolysis by using enormous amounts of electric power, which in its turn has to be generated. Producing electricity by burning fossil fuels, of course, cannot be a rational solution. Hydroelectric power can give but a very modest contribution. Therefore, it will be necessary to generate large amounts of electric power by nuclear energy of by renewable energies. A hydrogen economy based on nuclear electricity would imply the construction of thousands of fission reactors, thereby magnifying all the problems related to the use of nuclear energy (e.g., safe disposal of radioactive waste, nuclear proliferation, plant decommissioning, uranium shortage). In principle, wind, photovoltaic, and concentrated solar power have the potential to produce enormous amounts of electric power, but, except for wind, such technologies are too underdeveloped and expensive to tackle such a big task in a short period of time. A full development of a hydrogen economy needs also improvement in hydrogen storage, transportation and distribution

  14. Hydrogen Bonding in Hydrogenated Amorphous Germanium

    Institute of Scientific and Technical Information of China (English)

    M.S.Abo-Ghazala; S. Al Hazmy

    2004-01-01

    Thin films of hydrogenated amorphous germanium (a-Ge:H) were prepared by radio frequency glow discharge deposition at various substrate temperatures. The hydrogen distribution and bonding structure in a-Ge:H were discussed based on infrared absorption data. The correlation between infrared absorption spectra and hydrogen effusion measurements was used to determine the proportionality constant for each vibration mode of the Ge-H bonds. The results reveal that the bending mode appearing at 835 cm?1 is associated with the Ge-H2 (dihydride) groups on the internal surfaces of voids. While 1880 cm?1 is assigned to vibrations of Ge-H (monohydride) groups in the bulk, the 2000 cm?1 stretching mode is attributed to Ge-H and Ge-H2 bonds located on the surfaces of voids. For films associated with bending modes in the infrared spectra, the proportionality constant values of the stretching modes near 1880 and 2000 cm?1 are found to be lower than those of films which had no corresponding bending modes.

  15. [Phosphate solubilization of Aureobasidium pullulan F4 and its mechanism].

    Science.gov (United States)

    Wang, Dan; Zhan, Jing; Sun, Qing-Ye

    2014-07-01

    The Aureobasidium pullulans F4 was isolated from the rhizosphere of Hippochaete ramosissimum in Tongguanshan mine wasteland in Tongling City, Anhui Province. Liquid culture was conducted with four kinds of phosphorus sources, calcium phosphate, aluminum phosphate, ferric phosphate and rock phosphate to determine the pH, dissolved phosphorus, phosphorus in the bacteria and organic acid in the solution. The results showed that the phosphate solubilization by A. pullulans F4 varied with phosphorus sources, which decreased in order of aluminum phosphate > ferric phosphate, calcium phosphate > rock phosphate. The amounts of dissolved phosphorus in the different treatments were all higher than 200 mg x L(-1). The pH of the medium dropped immediately in 48 h, and the aluminum phosphate and ferric phosphate treatments showed a greater decrease in pH than the calcium phosphate and rock phosphate treatments. The organic acid synthesized by A. pullulans F4 included oxalic acid, citric acid and tartaric acid, and oxalic acid, among which oxalic acid was the dominated component. The phosphate dissolving capacity of A. pullulans F4 showed no significant correlation with organic acid, but significantly correlated with the pH. The available phosphorus was significantly improved with the combined application of A. pullulans F4 and glucose, suggesting A. pullulans F4 was a potent candidate for remediation of copper mine wastelands.

  16. Interstellar hydrogen sulfide.

    Science.gov (United States)

    Thaddeus, P.; Kutner, M. L.; Penzias, A. A.; Wilson, R. W.; Jefferts, K. B.

    1972-01-01

    Hydrogen sulfide has been detected in seven Galactic sources by observation of a single line corresponding to the rotational transition from the 1(sub 10) to the 1(sub 01) levels at 168.7 GHz. The observations show that hydrogen sulfide is only a moderately common interstellar molecule comparable in abundance to H2CO and CS, but somewhat less abundant than HCN and much less abundant than CO.

  17. Cryogenic hydrogen release research.

    Energy Technology Data Exchange (ETDEWEB)

    LaFleur, Angela Christine [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-12-01

    The objective of this project was to devolop a plan for modifying the Turbulent Combustion Laboratory (TCL) with the necessary infrastructure to produce a cold (near liquid temperature) hydrogen jet. The necessary infrastructure has been specified and laboratory modifications are currently underway. Once complete, experiments from this platform will be used to develop and validate models that inform codes and standards which specify protection criteria for unintended releases from liquid hydrogen storage, transport, and delivery infrastructure.

  18. Purdue Hydrogen Systems Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Jay P Gore; Robert Kramer; Timothee L Pourpoint; P. V. Ramachandran; Arvind Varma; Yuan Zheng

    2011-12-28

    The Hydrogen Systems Laboratory in a unique partnership between Purdue University's main campus in West Lafayette and the Calumet campus was established and its capabilities were enhanced towards technology demonstrators. The laboratory engaged in basic research in hydrogen production and storage and initiated engineering systems research with performance goals established as per the USDOE Hydrogen, Fuel Cells, and Infrastructure Technologies Program. In the chemical storage and recycling part of the project, we worked towards maximum recycling yield via novel chemical selection and novel recycling pathways. With the basic potential of a large hydrogen yield from AB, we used it as an example chemical but have also discovered its limitations. Further, we discovered alternate storage chemicals that appear to have advantages over AB. We improved the slurry hydrolysis approach by using advanced slurry/solution mixing techniques. We demonstrated vehicle scale aqueous and non-aqueous slurry reactors to address various engineering issues in on-board chemical hydrogen storage systems. We measured the thermal properties of raw and spent AB. Further, we conducted experiments to determine reaction mechanisms and kinetics of hydrothermolysis in hydride-rich solutions and slurries. We also developed a continuous flow reactor and a laboratory scale fuel cell power generation system. The biological hydrogen production work summarized as Task 4.0 below, included investigating optimal hydrogen production cultures for different substrates, reducing the water content in the substrate, and integrating results from vacuum tube solar collector based pre and post processing tests into an enhanced energy system model. An automated testing device was used to finalize optimal hydrogen production conditions using statistical procedures. A 3 L commercial fermentor (New Brunswick, BioFlo 115) was used to finalize testing of larger samples and to consider issues related to scale up

  19. Phosphate Phosphors for Solid-State Lighting

    CERN Document Server

    Shinde, Kartik N; Swart, H C; Park, Kyeongsoon

    2012-01-01

    The idea for this book arose out of the realization that, although excellent surveys and a phosphor handbook are available, there is no single source covering the area of phosphate based phosphors especially for lamp industry. Moreover, as this field gets only limited attention in most general books on luminescence, there is a clear need for a book in which attention is specifically directed toward this rapidly growing field of solid state lighting and its many applications. This book is aimed at providing a sound introduction to the synthesis and optical characterization of phosphate phosphor for undergraduate and graduate students as well as teachers and researchers. The book provides guidance through the multidisciplinary field of solid state lighting specially phosphate phosphors for beginners, scientists and engineers from universities, research organizations, and especially industry. In order to make it useful for a wide audience, both fundamentals and applications are discussed, together.

  20. Computational Design of Biomimetic Phosphate Scavengers

    DEFF Research Database (Denmark)

    Gruber, Mathias Felix; Wood, Elizabeth Baker; Truelsen, Sigurd Friis

    2015-01-01

    for phosphorus recovery, as well as improving existing techniques, has increased. In this study we apply a hybrid simulation approach of molecular dynamics and quantum mechanics to investigate the binding modes of phosphate anions by a small intrinsically disordered peptide. Our results confirm...... that the conformational ensemble of the peptide is significantly changed, or stabilized, by the binding of phosphate anions and that binding does not take place purely as a result of a stable P-loop binding nest, but rather that multiple binding modes may be involved. Such small synthetic peptides capable of binding...... phosphate could be the starting point of new novel technological approaches toward phosphorus recovery, and they represent an excellent model system for investigating the nature and dynamics of functional de novo designed intrinsically disordered proteins....

  1. Solid state NMR study calcium phosphate ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Miquel, J.L.; Facchini, L.; Legrand, A.P. (Laboratoire de Physique Quantique, Paris (France). CNRS, URA421, ESPCI); Rey, C. (CNRS, Toulouse (France). ENSC. Laboratoire de Physico-chimie des Solides); Lemaitre, J. (EPF Lausanne (France). Laboratoire de Technologie des Poudres)

    1990-04-01

    High-resolution {sup 31}P and {sup 1}H NMR spectra at 40 and 121 MHz {sup 31}P and 300 MHz {sup 1}H of synthetic and biological samples of calcium phosphates have been obtained by magic angle spinning (MAS) at spinning speeds up to 6.5 kHz, and high power proton decoupling. The samples include crystalline hydroxyapatite, a deficient hydroxyapatite characterized by a Ca/P atomic ratio of 1.5, a poorly crystallized hydroxyapatite, monetite, brushite, octacalcium phosphate, {beta}-tricalcium phosphate and rabbit femoral bone. The interactions between nuclei in unlike structures and the mobility of acid protons are discussed. (author). 11 refs.; 2 figs.; 1 tab.

  2. Dicalcium phosphate cements: brushite and monetite.

    Science.gov (United States)

    Tamimi, Faleh; Sheikh, Zeeshan; Barralet, Jake

    2012-02-01

    Dicalcium phosphate cements were developed two decades ago and ever since there has been a substantial growth in research into improving their properties in order to satisfy the requirements needed for several clinical applications. The present paper presents an overview of the rapidly expanding research field of the two main dicalcium phosphate bioceramics: brushite and monetite. This review begins with a summary of all the different formulae developed to prepare dicalcium phosphate cements, and their setting reaction, in order to set the scene for the key cement physical and chemical properties, such as compressive and tensile strength, cohesion, injectability and shelf-life. We address the issue of brushite conversion into either monetite or apatite. Moreover, we discuss the in vivo behavior of the cements, including their ability to promote bone formation, biodegradation and potential clinical applications in drug delivery, orthopedics, craniofacial surgery, cancer therapy and biosensors.

  3. Zirconium phosphate binder for periclase refractories

    Energy Technology Data Exchange (ETDEWEB)

    Volceanov, E. [ICEM S.A., Bucharest (Romania). Metallurgical Research Inst.; Georgescu, M.; Volceanov, A. [Universitatea Politehnica, Bucharest (Romania). Faculty of Industrial Chemistry; Mihalache, F. [REAL S.A., Ploiesti (Romania)

    2002-07-01

    Present paper brings information concerning the physical-mechanical properties of some high thermal resistant composites with phosphate bonding obtained from periclase clinker as solid component and various zirconium phosphates solutions as liquid component: ZI, ZII and ZIII. All these solutions were prepared from hydrous zirconia and orthophosphoric acid. The batches corresponding to a weight ratio solid / liquid = 3 / 1, have shown a good hardening behavior at normal temperature, especially for the ZII binder. Such compositions exhibit a very good thermal-mechanical behavior in the temperature range 1400 C - 1750 C. X-ray diffraction and electronomicroscopy (TEM) analysis provided information concerning the evolution of phase composition and microstructure during heating of the thermal resistant specimens chemically bound with a zirconium phosphate binder. (orig.)

  4. Hydrogen Delivery Technical Team Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    None

    2013-06-01

    The mission of the Hydrogen Delivery Technical Team (HDTT) is to enable the development of hydrogen delivery technologies, which will allow for fuel cell competitiveness with gasoline and hybrid technologies by achieving an as-produced, delivered, and dispensed hydrogen cost of $2-$4 per gallon of gasoline equivalent of hydrogen.

  5. Nanostructured materials for hydrogen storage

    Science.gov (United States)

    Williamson, Andrew J.; Reboredo, Fernando A.

    2007-12-04

    A system for hydrogen storage comprising a porous nano-structured material with hydrogen absorbed on the surfaces of the porous nano-structured material. The system of hydrogen storage comprises absorbing hydrogen on the surfaces of a porous nano-structured semiconductor material.

  6. Electrochemical hydrogen Storage Systems

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Digby Macdonald

    2010-08-09

    As the global need for energy increases, scientists and engineers have found a possible solution by using hydrogen to power our world. Although hydrogen can be combusted as a fuel, it is considered an energy carrier for use in fuel cells wherein it is consumed (oxidized) without the production of greenhouse gases and produces electrical energy with high efficiency. Chemical storage of hydrogen involves release of hydrogen in a controlled manner from materials in which the hydrogen is covalently bound. Sodium borohydride and aminoborane are two materials given consideration as chemical hydrogen storage materials by the US Department of Energy. A very significant barrier to adoption of these materials as hydrogen carriers is their regeneration from 'spent fuel,' i.e., the material remaining after discharge of hydrogen. The U.S. Department of Energy (DOE) formed a Center of Excellence for Chemical Hydrogen Storage, and this work stems from that project. The DOE has identified boron hydrides as being the main compounds of interest as hydrogen storage materials. The various boron hydrides are then oxidized to release their hydrogen, thereby forming a 'spent fuel' in the form of a lower boron hydride or even a boron oxide. The ultimate goal of this project is to take the oxidized boron hydrides as the spent fuel and hydrogenate them back to their original form so they can be used again as a fuel. Thus this research is essentially a boron hydride recycling project. In this report, research directed at regeneration of sodium borohydride and aminoborane is described. For sodium borohydride, electrochemical reduction of boric acid and sodium metaborate (representing spent fuel) in alkaline, aqueous solution has been investigated. Similarly to literature reports (primarily patents), a variety of cathode materials were tried in these experiments. Additionally, approaches directed at overcoming electrostatic repulsion of borate anion from the cathode, not

  7. Conductive dense hydrogen

    Science.gov (United States)

    Eremets, M.; Troyan, I.

    2012-12-01

    Hydrogen at ambient pressures and low temperatures forms a molecular crystal which is expected to display metallic properties under megabar pressures. This metal is predicted to be superconducting with a very high critical temperature Tc of 200-400 K. The superconductor may potentially be recovered metastably at ambient pressures, and it may acquire a new quantum state as a metallic superfluid and a superconducting superfluid. Recent experiments performed at low temperatures T 220 GPa, new Raman modes arose, providing evidence for the transformation to a new opaque and electrically conductive phase IV. Above 260 GPa, in the next phase V, hydrogen reflected light well. Its resistance was nearly temperature-independent over a wide temperature range, down to 30 K, indicating that the hydrogen was metallic. Releasing the pressure induced the metallic phase to transform directly into molecular hydrogen with significant hysteresis at 200 GPa and 295 K. These data were published in our paper: M. I. Eremets and I. A. Troyan "Conductive dense hydrogen." Nature Materials 10: 927-931. We will present also new results on hydrogen: phase diagram with phases IV and V determined in P,T domain up to 300 GPa and 350 K. We will also discuss possible structures of phase IV based on our Raman and infrared measurements up to 300 GPa.

  8. Metallic hydrogen research

    Energy Technology Data Exchange (ETDEWEB)

    Burgess, T.J.; Hawke, R.S.

    1978-11-16

    Theoretical studies predict that molecular hydrogen can be converted to the metallic phase at very high density and pressure. These conditions were achieved by subjecting liquid hydrogen to isentropic compression in a magnetic-flux compression device. Hydrogen became electrically conducting at a density of about 1.06 g/cm/sup 3/ and a calculated pressure of about 2 Mbar. In the experimental device, a cylindrical liner, on implosion by high explosive, compresses a magnetic flux which in turn isentropically compresses a hydrogen sample; coaxial conical anvils prevent escape of the sample during compression. One anvil contains a coaxial cable that uses alumina ceramic as an insulator; this probe allows continuous measurement of the electrical conductivity of the hydrogen. A flash x-ray radiograph exposed during the experiment records the location of the sample-tube boundaries and permits calculation of the sample density. The theoretical underpinnings of the metallic transition of hydrogen are briefly summarized, and the experimental apparatus and technique, analytical methods, and results are described. 9 figures.

  9. Examining hydrogen transitions.

    Energy Technology Data Exchange (ETDEWEB)

    Plotkin, S. E.; Energy Systems

    2007-03-01

    This report describes the results of an effort to identify key analytic issues associated with modeling a transition to hydrogen as a fuel for light duty vehicles, and using insights gained from this effort to suggest ways to improve ongoing modeling efforts. The study reported on here examined multiple hydrogen scenarios reported in the literature, identified modeling issues associated with those scenario analyses, and examined three DOE-sponsored hydrogen transition models in the context of those modeling issues. The three hydrogen transition models are HyTrans (contractor: Oak Ridge National Laboratory), MARKAL/DOE* (Brookhaven National Laboratory), and NEMS-H2 (OnLocation, Inc). The goals of these models are (1) to help DOE improve its R&D effort by identifying key technology and other roadblocks to a transition and testing its technical program goals to determine whether they are likely to lead to the market success of hydrogen technologies, (2) to evaluate alternative policies to promote a transition, and (3) to estimate the costs and benefits of alternative pathways to hydrogen development.

  10. Smart materials behavior in phosphates: role of hydroxyl groups and relevance to antiwear films.

    Science.gov (United States)

    Shakhvorostov, Dmitry; Müser, Martin H; Song, Yang; Norton, Peter R

    2009-07-28

    The elastic properties of materials under high pressure are relevant to the understanding and performance of many systems of current interest, for example, in geology and tribology. Of particular interest is the origin of the dramatic increase in modulus with increasing pressure, a response which is also called "smart materials behavior." In this context, simple phosphate-containing materials have been studied experimentally and theoretically, and the origins of this behavior have been associated with factors such as coordination of the cations and changes in the degree of polymerization and hydrogenation of the phosphate units. In the present paper we extend the former analysis on simple metal phosphate model compounds to so-called thermal films, an intermediate stage in the formation of effective antiwear films. The material was produced by heating a commercial zinc dialkyldithiophosphate (ZDDP), a common antiwear additive in lubricating oils, in poly-alpha-olefin base oil solutions to 150 degrees C, a process known to produce the thermal films. Its structure and equation of state were studied by means of x-ray diffraction and IR synchrotron radiation techniques during compression up to 25 GPa in a diamond anvil cell as well as during the subsequent decompression. As is the case for the simple metal phosphates, we find that the thermal films are relatively soft at low pressures but stiffen rapidly and ultimately amorphize irreversibly at high pressure. However, in addition to phase transformations involving cation sites occurring in the metal phosphates studied previously, thermal films undergo displacive transitions associated with instabilities of the hydroxyl groups. These results may imply that ZDDP ligands and those of the transformed materials not only affect ZDDP decomposition rate in engines but also the mechanical properties of the resulting antiwear films.

  11. Phosphate oxygen isotopic evidence for a temperate and biologically active Archaean ocean.

    Science.gov (United States)

    Blake, Ruth E; Chang, Sae Jung; Lepland, Aivo

    2010-04-15

    Oxygen and silicon isotope compositions of cherts and studies of protein evolution have been interpreted to reflect ocean temperatures of 55-85 degrees C during the early Palaeoarchaean era ( approximately 3.5 billion years ago). A recent study combining oxygen and hydrogen isotope compositions of cherts, however, makes a case for Archaean ocean temperatures being no greater than 40 degrees C (ref. 5). Ocean temperature can also be assessed using the oxygen isotope composition of phosphate. Recent studies show that (18)O:(16)O ratios of dissolved inorganic phosphate (delta(18)O(P)) reflect ambient seawater temperature as well as biological processing that dominates marine phosphorus cycling at low temperature. All forms of life require and concentrate phosphorus, and as a result of biological processing, modern marine phosphates have delta(18)O(P) values typically between 19-26 per thousand (VSMOW), highly evolved from presumed source values of approximately 6-8 per thousand that are characteristic of apatite in igneous rocks and meteorites. Here we report oxygen isotope compositions of phosphates in sediments from the 3.2-3.5-billion-year-old Barberton Greenstone Belt in South Africa. We find that delta(18)O(P) values range from 9.3 per thousand to 19.9 per thousand and include the highest values reported for Archaean rocks. The temperatures calculated from our highest delta(18)O(P) values and assuming equilibrium with sea water with delta(18)O = 0 per thousand (ref. 12) range from 26 degrees C to 35 degrees C. The higher delta(18)O(P) values are similar to those of modern marine phosphate and suggest a well-developed phosphorus cycle and evolved biologic activity on the Archaean Earth.

  12. Neutron scattering and hydrogen storage

    Directory of Open Access Journals (Sweden)

    A.J. Ramirez-Cuesta

    2009-11-01

    Full Text Available Hydrogen has been identified as a fuel of choice for providing clean energy for transport and other applications across the world and the development of materials to store hydrogen efficiently and safely is crucial to this endeavour. Hydrogen has the largest scattering interaction with neutrons of all the elements in the periodic table making neutron scattering ideal for studying hydrogen storage materials. Simultaneous characterisation of the structure and dynamics of these materials during hydrogen uptake is straightforward using neutron scattering techniques. These studies will help us to understand the fundamental properties of hydrogen storage in realistic conditions and hence design new hydrogen storage materials.

  13. Removal of Phosphate from Aqueous Solution with Modified Bentonite

    Institute of Scientific and Technical Information of China (English)

    唐艳葵; 童张法; 魏光涛; 李仲民; 梁达文

    2006-01-01

    Bentonite combined with sawdust and other metallic compounds was used to remove phosphate from aqueous solutions in this study. The adsorption characteristics of phosphate on the modified bentonite were investigated, including the effects of temperature, adsorbent dosage, initial concentration of phosphate and pH on removal of phosphate by conducting a series of batch adsorption experiments. The results showed that 98% of phosphate removal rate was obtained since sawdust and bentonite used in this investigation were abundantly and locally available. It is concluded that modified bentonite is a relatively efficient, low cost and easily available adsorbent for the removal of phosphate from aqueous solutions.

  14. Phosphate valorization by dry chlorination route

    OpenAIRE

    Kanari N.; Menad N.; Diot F.; Allain E.; Yvon J.

    2016-01-01

    International audience; This work deals with the extraction of phosphorus chlorinated compounds from phosphate materials using chlorination with gaseous chlorine. An industrial sample of dicalcium phosphate dihydrate, after transformation into calcium pyrophosphate (Ca 2 P 2 O 7), is subjected to reactions with Cl 2 +CO+N 2 and Cl 2 +C+N 2 at temperatures ranging from 625 to 950 °C using boat experiments. Gathering results of the thermodynamic predictions and TG/DT analysis with those of SEM ...

  15. Phosphate solubilizing bacteria around Indian peninsula

    Digital Repository Service at National Institute of Oceanography (India)

    DeSouza, M.J.B.D; Nair, S.; Chandramohan, D

    nitrophenylphosphate by the culture. One mole of nitrophenol is equivalent to 1 atom of phosphorus. The absorbance was read at 418 nm using DU-6 Beckmann spectrophotometer. The activity was expressed as ?mol.Pml-1d-1. The cultures which showed good phosphate... strengthening the fact that the isolates are of marine origin. Maximum activity of 5 ?mol.P.ml-1d-1 was observed for strain P6 in 4.5% NaCl Location Beaches Islands Coasts Offshore Table 1?Phosphate solubilizing bacteria in various niches. No. of cultures...

  16. Glusoce-6-phosphate dehydrogenase- History and diagnosis

    Directory of Open Access Journals (Sweden)

    K Gautam

    2016-09-01

    Full Text Available Glucose-6-phosphate dehydrogenase deficiency is the most common enzymatic defect of red blood cells, which increases the vulnerability of erythrocytes to oxidative stress leading to hemolytic anemia. Since its identification more than 60 years ago, much has been done with respect to its clinical diagnosis, laboratory diagnosis and treatment. Association of G6PD is not just limited to anti malarial drugs, but a vast number of other diseases. In this article, we aimed to review the history of Glucose-6-phosphate dehydrogenase, the diagnostic methods available along with its association with other noncommunicable diseases. 

  17. Dual mechanism of ion permeation through VDAC revealed with inorganic phosphate ions and phosphate metabolites.

    Science.gov (United States)

    Krammer, Eva-Maria; Vu, Giang Thi; Homblé, Fabrice; Prévost, Martine

    2015-01-01

    In the exchange of metabolites and ions between the mitochondrion and the cytosol, the voltage-dependent anion channel (VDAC) is a key element, as it forms the major transport pathway for these compounds through the mitochondrial outer membrane. Numerous experimental studies have promoted the idea that VDAC acts as a regulator of essential mitochondrial functions. In this study, using a combination of molecular dynamics simulations, free-energy calculations, and electrophysiological measurements, we investigated the transport of ions through VDAC, with a focus on phosphate ions and metabolites. We showed that selectivity of VDAC towards small anions including monovalent phosphates arises from short-lived interactions with positively charged residues scattered throughout the pore. In dramatic contrast, permeation of divalent phosphate ions and phosphate metabolites (AMP and ATP) involves binding sites along a specific translocation pathway. This permeation mechanism offers an explanation for the decrease in VDAC conductance measured in the presence of ATP or AMP at physiological salt concentration. The binding sites occur at similar locations for the divalent phosphate ions, AMP and ATP, and contain identical basic residues. ATP features a marked affinity for a central region of the pore lined by two lysines and one arginine of the N-terminal helix. This cluster of residues together with a few other basic amino acids forms a "charged brush" which facilitates the passage of the anionic metabolites through the pore. All of this reveals that VDAC controls the transport of the inorganic phosphates and phosphate metabolites studied here through two different mechanisms.

  18. Performance of pineapple slips inoculated with diazotrophic phosphate-solubilizing bacteria and rock phosphate

    Directory of Open Access Journals (Sweden)

    Lílian Estrela Borges Baldotto

    2014-06-01

    Full Text Available Besides fixing N2, some diazotrophic bacteria or diazotrophs, also synthesize organic acids and are able to solubilize rock phosphates, increasing the availability of P for plants. The application of these bacteria to pineapple leaf axils in combination with rock phosphate could increase N and P availability for the crop, due to the bacterial activity of biological nitrogen fixation and phosphate solubilization. The objectives of this study were: (i to select and characterize diazotrophs able to solubilize phosphates in vitro and (ii evaluate the initial performance of the pineapple cultivars Imperial and Pérola in response to inoculation with selected bacteria in combination with rock phosphate. The experiments were conducted at Universidade Estadual do Norte Fluminense Darcy Ribeiro, in 2009. In the treatments with bacteria the leaf contents of N, P and K were higher than those of the controls, followed by an increase in plant growth. These results indicate that the combined application of diazotrophic phosphate-solubilizing bacteria Burkholderia together with Araxá rock phosphate can be used to improve the initial performance of pineapple slips.

  19. California Hydrogen Infrastructure Project

    Energy Technology Data Exchange (ETDEWEB)

    Heydorn, Edward C

    2013-03-12

    Air Products and Chemicals, Inc. has completed a comprehensive, multiyear project to demonstrate a hydrogen infrastructure in California. The specific primary objective of the project was to demonstrate a model of a real-world retail hydrogen infrastructure and acquire sufficient data within the project to assess the feasibility of achieving the nation's hydrogen infrastructure goals. The project helped to advance hydrogen station technology, including the vehicle-to-station fueling interface, through consumer experiences and feedback. By encompassing a variety of fuel cell vehicles, customer profiles and fueling experiences, this project was able to obtain a complete portrait of real market needs. The project also opened its stations to other qualified vehicle providers at the appropriate time to promote widespread use and gain even broader public understanding of a hydrogen infrastructure. The project engaged major energy companies to provide a fueling experience similar to traditional gasoline station sites to foster public acceptance of hydrogen. Work over the course of the project was focused in multiple areas. With respect to the equipment needed, technical design specifications (including both safety and operational considerations) were written, reviewed, and finalized. After finalizing individual equipment designs, complete station designs were started including process flow diagrams and systems safety reviews. Material quotes were obtained, and in some cases, depending on the project status and the lead time, equipment was placed on order and fabrication began. Consideration was given for expected vehicle usage and station capacity, standard features needed, and the ability to upgrade the station at a later date. In parallel with work on the equipment, discussions were started with various vehicle manufacturers to identify vehicle demand (short- and long-term needs). Discussions included identifying potential areas most suited for hydrogen fueling

  20. Hydrogen storage and generation system

    Science.gov (United States)

    Dentinger, Paul M.; Crowell, Jeffrey A. W.

    2010-08-24

    A system for storing and generating hydrogen generally and, in particular, a system for storing and generating hydrogen for use in an H.sub.2/O.sub.2 fuel cell. The hydrogen storage system uses the beta particles from a beta particle emitting material to degrade an organic polymer material to release substantially pure hydrogen. In a preferred embodiment of the invention, beta particles from .sup.63Ni are used to release hydrogen from linear polyethylene.

  1. Evaluation of intestinal phosphate binding to improve the safety profile of oral sodium phosphate bowel cleansing.

    Directory of Open Access Journals (Sweden)

    Stef Robijn

    Full Text Available Prior to colonoscopy, bowel cleansing is performed for which frequently oral sodium phosphate (OSP is used. OSP results in significant hyperphosphatemia and cases of acute kidney injury (AKI referred to as acute phosphate nephropathy (APN; characterized by nephrocalcinosis are reported after OSP use, which led to a US-FDA warning. To improve the safety profile of OSP, it was evaluated whether the side-effects of OSP could be prevented with intestinal phosphate binders. Hereto a Wistar rat model of APN was developed. OSP administration (2 times 1.2 g phosphate by gavage with a 12h time interval induced bowel cleansing (severe diarrhea and significant hyperphosphatemia (21.79 ± 5.07 mg/dl 6h after the second OSP dose versus 8.44 ± 0.97 mg/dl at baseline. Concomitantly, serum PTH levels increased fivefold and FGF-23 levels showed a threefold increase, while serum calcium levels significantly decreased from 11.29 ± 0.53 mg/dl at baseline to 8.68 ± 0.79 mg/dl after OSP. OSP administration induced weaker NaPi-2a staining along the apical proximal tubular membrane. APN was induced: serum creatinine increased (1.5 times baseline and nephrocalcinosis developed (increased renal calcium and phosphate content and calcium phosphate deposits on Von Kossa stained kidney sections. Intestinal phosphate binding (lanthanum carbonate or aluminum hydroxide was not able to attenuate the OSP induced side-effects. In conclusion, a clinically relevant rat model of APN was developed. Animals showed increased serum phosphate levels similar to those reported in humans and developed APN. No evidence was found for an improved safety profile of OSP by using intestinal phosphate binders.

  2. Analysis of serum phosphate control and phosphate binder utilization in incident hemodialysis patients

    Directory of Open Access Journals (Sweden)

    Farr

    2014-07-01

    Full Text Available Kimberly F Farrand,1 J Brian Copley,1 Jamie Heise,1 Moshe Fridman,2 Michael S Keith,1 Lynne Poole3 1Shire, Wayne, PA, USA; 2AMF Consulting, Los Angeles, CA, USA; 3Shire, Basingstoke, UK Abstract: The purpose of this study was to conduct a retrospective analysis of serum phosphate level variability in patients new to hemodialysis (HD and to identify patient characteristics associated with this variability. The medical records of 47,742 incident HD patients attending US outpatient dialysis centers between January 1, 2006 and March 31, 2009 were analyzed. Monthly mean serum phosphate levels determined over a 6-month evaluation period (months 4–9 after HD initiation were assigned to one of three strata: low (<1.13 mmol/L [<3.5 mg/dL]; target (1.13–1.78 mmol/L [3.5–5.5 mg/dL]; or high (>1.78 mmol/L [>5.5 mg/dL]. Patients were classified into one of six serum phosphate variability groups based on variability among monthly mean phosphate levels over the 6-month evaluation period: consistently target; consistently high; high-to-target; high-to-low; target-to-low; or consistently low. Only 15% of patients (consistently target group maintained monthly mean serum phosphate levels within the target range throughout the 6-month evaluation period. Age, Charlson comorbidity index, serum phosphate, and intact parathyroid hormone levels prior to HD initiation were strongly associated (P<0.001 with serum phosphate levels after HD initiation. Overall patient-reported phosphate binder usage increased from 35% at baseline to 52% at end of study. The low proportion of patients achieving target phosphate levels and low rates of phosphate binder usage observed during the study suggest that alternative strategies could be developed to control serum phosphate levels. Possible strategies that might be incorporated to help improve the management of hyperphosphatemia in incident HD patients include dietary modification, dialysis optimization, and earlier and sustained

  3. Energy conversion from aluminium and phosphate rich solution via ZnO activation of aluminium

    Energy Technology Data Exchange (ETDEWEB)

    Slaughter, Gymama, E-mail: gslaught@umbc.edu; Sunday, Joshua; Stevens, Brian

    2015-08-01

    Electrochemical power sources have motivated intense research efforts in the development of alternative ‘green’ power sources for ultra-low powered bioelectronic devices. Biofuel cells employ immobilized enzymes to convert the available chemical energy of organic fuels directly into electricity. However, biofuel cells are limited by short lifetime due to enzyme inactivation and frequent need to incorporate mediators to shuttle electrons to the final electron acceptor. In this context, other electrochemical power sources are necessary in energy conversion and storage device applications. Here we report on the fabrication and characterization of a membrane-free aluminium/phosphate cell based on the activation of aluminium (Al) using ZnO nanocrystal in an Al/phosphate cell as a ‘green’ alternative to the traditional enzymatic biofuel cells. The hybrid cell operates in neutral phosphate buffer solution and physiological saline buffer. The ZnO modifier in the phosphate rich electrolyte activated the pitting of Al resulting in the production of hydrogen, as the reducing agent for the reduction of H{sub 2}PO{sub 4}{sup −} ions to HPO{sub 3}{sup 2−} ions at a formal potential of −0.250 V vs. Ag/AgCl. Specifically, the fabricated cell operating in phosphate buffer and physiological saline buffer exhibit an open-circuit voltage of 0.810 V and 0.751 V and delivered a maximum power density of 0.225 mW cm{sup −2} and 1.77 mW cm{sup −2}, respectively. Our results demonstrate the feasibility of generating electricity by activating Al as anodic material in a hybrid cell supplied with phosphate rich electrolyte. Our approach simplifies the construction and operation of the electrochemical power source as a novel “green” alternative to the current anodic substrates used in enzymatic biofuel cells for low power bioelectronics applications. - Graphical abstract: Display Omitted - Highlights: • ZnO activation of metallic Al for generating electricity for

  4. TUCS/phosphate mineralization of actinides

    Energy Technology Data Exchange (ETDEWEB)

    Nash, K.L. [Argonne National Lab., IL (United States)

    1997-10-01

    This program has as its objective the development of a new technology that combines cation exchange and mineralization to reduce the concentration of heavy metals (in particular actinides) in groundwaters. The treatment regimen must be compatible with the groundwater and soil, potentially using groundwater/soil components to aid in the immobilization process. The delivery system (probably a water-soluble chelating agent) should first concentrate the radionuclides then release the precipitating anion, which forms thermodynamically stable mineral phases, either with the target metal ions alone or in combination with matrix cations. This approach should generate thermodynamically stable mineral phases resistant to weathering. The chelating agent should decompose spontaneously with time, release the mineralizing agent, and leave a residue that does not interfere with mineral formation. For the actinides, the ideal compound probably will release phosphate, as actinide phosphate mineral phases are among the least soluble species for these metals. The most promising means of delivering the precipitant would be to use a water-soluble, hydrolytically unstable complexant that functions in the initial stages as a cation exchanger to concentrate the metal ions. As it decomposes, the chelating agent releases phosphate to foster formation of crystalline mineral phases. Because it involves only the application of inexpensive reagents, the method of phosphate mineralization promises to be an economical alternative for in situ immobilization of radionuclides (actinides in particular). The method relies on the inherent (thermodynamic) stability of actinide mineral phases.

  5. Electrosprayed calcium phosphate coatings for biomedical purposes

    NARCIS (Netherlands)

    Leeuwenburgh, Sander Cornelis Gerardus

    2006-01-01

    In this thesis, the suitability of the Electrostatic Spray Deposition (ESD) technique was studied for biomedical purposes, i.e., deposition of calcium phosphate (CaP) coatings onto titanium substrates. Using ESD, which is a simple and cheap deposition method for inorganic and organic coatings, it wa

  6. Bismuth phosphates as intermediate temperature proton conductors

    DEFF Research Database (Denmark)

    Huang, Yunjie; Christensen, Erik; Shuai, Qin

    2017-01-01

    Proton conducting electrolyte materials operational in the intermediate temperature range of 200-400 °C are of special interest for applications in fuel cells and water electrolysers. Bismuth phosphates in forms of polycrystalline powders and amorphous glasses are synthesized and investigated...

  7. Superconducting oxides containing sulphate and phosphate groups

    Science.gov (United States)

    Scorzelli, R. B.; Baggio-Saitovitch, E.; Giordanengo, B.; Elmassalami, M.; Dominguez, A. B.; Bustamante Dominguez, A.

    1994-12-01

    The effects of partial substitution of Sr and Ca in Y-Ba-Cu-O related materials containing sulphate and phosphate groups have been investigated. e57Fe Mössbauer measurements were performed on samples doped with lat. % e57Fe and the spectral components related to different Cu sites and oxygen vacancies.

  8. FACTORS INFLUENCING FRICTION OF PHOSPHATE COATINGS,

    Science.gov (United States)

    surface roughness, crystalline structure , and velocity. The coefficients of friction for manganese phosphate coatings did not differ to any practical...The coefficient of friction was independent of the applied load. Velocity during dynamic testing, surface finish, and crystalline structure influenced

  9. Three-dimensionally Perforated Calcium Phosphate Ceramics

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Porous calcium phosphate ceramics were produced by compression molding using a special mold followed by sintering. The porous calcium phosphate ceramics have three-dimensional and penetrated open pores380-400μm in diameter spaced at intervals of 200μm. The layers of the linear penetration pores alternately lay perpendicular to pore direction. The porosity was 59%-65% . The Ca/P molar ratios of the porous calcium phosphate ceramics range from 1.5 to 1.85. A binder containing methyl cellulose was most effective for preparing the powder compact among vinyl acetate, polyvinyl alcohol, starch, stearic acid, methyl cellulose and their mixtures. Stainless steel, polystyrene, nylon and bamboo were used as the long columnar male dies for the penetrated open pores. When polystyrene, nylon and bamboo were used as the long columnar male dies, the dies were burned out during the sintering process. Using stainless steel as the male dies with the removal of the dies before heat treatment resulted in a higher level of densification of the calcium phosphate ceramic.

  10. Hot Hydrogen Test Facility

    Science.gov (United States)

    Swank, W. David; Carmack, Jon; Werner, James E.; Pink, Robert J.; Haggard, DeLon C.; Johnson, Ryan

    2007-01-01

    The core in a nuclear thermal rocket will operate at high temperatures and in hydrogen. One of the important parameters in evaluating the performance of a nuclear thermal rocket is specific impulse, ISP. This quantity is proportional to the square root of the propellant's absolute temperature and inversely proportional to square root of its molecular weight. Therefore, high temperature hydrogen is a favored propellant of nuclear thermal rocket designers. Previous work has shown that one of the life-limiting phenomena for thermal rocket nuclear cores is mass loss of fuel to flowing hydrogen at high temperatures. The hot hydrogen test facility located at the Idaho National Lab (INL) is designed to test suitability of different core materials in 2500°C hydrogen flowing at 1500 liters per minute. The facility is intended to test low activity uranium containing materials but is also suited for testing cladding and coating materials. In this first installment the facility is described. Automated data acquisition, flow and temperature control, vessel compatibility with various core geometries and overall capabilities are discussed.

  11. Hydrogen-selective membrane

    Science.gov (United States)

    Collins, J.P.; Way, J.D.

    1995-09-19

    A hydrogen-selective membrane comprises a tubular porous ceramic support having a palladium metal layer deposited on an inside surface of the ceramic support. The thickness of the palladium layer is greater than about 10 {micro}m but typically less than about 20 {micro}m. The hydrogen permeation rate of the membrane is greater than about 1.0 moles/m{sup 2}s at a temperature of greater than about 500 C and a transmembrane pressure difference of about 1,500 kPa. Moreover, the hydrogen-to-nitrogen selectivity is greater than about 600 at a temperature of greater than about 500 C and a transmembrane pressure of about 700 kPa. Hydrogen can be separated from a mixture of gases using the membrane. The method may include the step of heating the mixture of gases to a temperature of greater than about 400 C and less than about 1000 C before the step of flowing the mixture of gases past the membrane. The mixture of gases may include ammonia. The ammonia typically is decomposed to provide nitrogen and hydrogen using a catalyst such as nickel. The catalyst may be placed inside the tubular ceramic support. The mixture of gases may be supplied by an industrial process such as the mixture of exhaust gases from the IGCC process. 9 figs.

  12. Magnetic liquefier for hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1992-12-31

    This document summarizes work done at the Astronautics Technology Center of the Astronautics Corporation of America (ACA) in Phase 1 of a four phase program leading to the development of a magnetic liquefier for hydrogen. The project involves the design, fabrication, installation, and operation of a hydrogen liquefier providing significantly reduced capital and operating costs, compared to present liquefiers. To achieve this goal, magnetic refrigeration, a recently developed, highly efficient refrigeration technology, will be used for the liquefaction process. Phase 1 project tasks included liquefier conceptual design and analysis, preliminary design of promising configurations, design selection, and detailed design of the selected design. Fabrication drawings and vendor specifications for the selected design were completed during detailed design. The design of a subscale, demonstration magnetic hydrogen liquefier represents a significant advance in liquefaction technology. The cost reductions that can be realized in hydrogen liquefaction in both the subscale and, more importantly, in the full-scale device are expected to have considerable impact on the use of liquid hydrogen in transportation, chemical, and electronic industries. The benefits to the nation from this technological advance will continue to have importance well into the 21st century.

  13. The hydrogen laminar jet

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Sanz, M. [Departamento de Motopropulsion y Termofluidomecanica, ETSI Aeronauticos, Universidad Politecnica de Madrid, 28040 Madrid (Spain); Rosales, M. [Department Ingenieria Termica y de Fluidos, Universidad Carlos III de Madrid, 28911, Leganes (Spain); Instituto de Innovacion en Mineria y Metalurgia, Avenida del Valle 738, Santiago (Chile); Sanchez, A.L. [Department Ingenieria Termica y de Fluidos, Universidad Carlos III de Madrid, 28911, Leganes (Spain)

    2010-04-15

    Numerical and asymptotic methods are used to investigate the structure of the hydrogen jet discharging into a quiescent air atmosphere. The analysis accounts in particular for the variation of the density and transport properties with composition. The Reynolds number of the flow R{sub j}, based on the initial jet radius a, the density {rho}{sub j} and viscosity {mu}{sub j} of the jet and the characteristic jet velocity u{sub j}, is assumed to take moderately large values, so that the jet remains slender and stable, and can be correspondingly described by numerical integration of the continuity, momentum and species conservation equations written in the boundary-layer approximation. The solution for the velocity and composition in the jet development region of planar and round jets, corresponding to streamwise distances of order R{sub j}a, is computed numerically, along with the solutions that emerge both in the near field and in the far field. The small value of the hydrogen-to-air molecular weight ratio is used to simplify the solution by considering the asymptotic limit of vanishing jet density. The development provides at leading-order explicit analytical expressions for the far-field velocity and hydrogen mass fraction that describe accurately the hydrogen jet near the axis. The information provided can be useful in particular to characterize hydrogen discharge processes from holes and cracks. (author)

  14. Saga of hydrogen civilization

    Energy Technology Data Exchange (ETDEWEB)

    Veziroglu, T.N. [Univ. of Miami, Coral Gables, FL (United States). Clean Energy Research Institute

    2008-09-30

    In the 1960s, air pollution in cities became an important issue hurting the health of people. The author became interested in environmental issues in general and air pollution in particular. He started studying possible vehicle fuels, with a view of determining the fuel which would cause little or no pollution. He particularly studied methanol, ethanol, ammonia and hydrogen as well as the gasohols (i.e., the mixtures of gasoline and methanol and/or ethanol). His investigation of fuels for transportation lasted five years (1967-1972). The result was that hydrogen is the cleanest fuel, and it is also the most efficient one. It would not produce CO (carbon monoxide), CO{sub 2} (carbon dioxide), SO{sub x}, hydrocarbons, soot and particulates. If hydrogen was burned in oxygen, it would not produce NO{sub x} either. If it burned in air, there would then be some NO{sub x} produced. Since the author has always believed that engineers and scientists should strive to find solutions to the problems facing humankind and the world, he established the Clean Energy Research Institute (CERI) at the University of Miami in 1973. The mission of the Institute was to find a solution or solutions to the energy problem, so the world economy can function properly and provide humankind with high living standards. To find clean forms of energy was also the mission of the Institute, so that they would not produce pollution and damage the health of flora, fauna and humans, as well as the environment of the planet Earth as a whole. CERI looked at all of the possible primary energy sources, including solar, wind, currents, waves, tides, geothermal, nuclear breeders and thermonuclear. Although they are much cleaner and would last much longer than fossil fuels, these sources were not practical for use. They were not storable or transportable by themselves, except nuclear. They could not be used as a fuel for transportation by themselves, except nuclear for marine transportation. In order to solve

  15. Hydrogen Contractors Meeting

    Energy Technology Data Exchange (ETDEWEB)

    Fitzsimmons, Tim [Dept. of Energy (DOE), Washington DC (United States). Office of Basic Energy Sciences. Division of Materials Sciences and Engineering

    2006-05-16

    This volume highlights the scientific content of the 2006 Hydrogen Contractors Meeting sponsored by the Division of Materials Sciences and Engineering (DMS&E) on behalf of the Office of Basic Energy Sciences (BES) of the U. S. Department of Energy (DOE). Hydrogen Contractors Meeting held from May 16-19, 2006 at the Crystal Gateway Marriott Hotel Arlington, Virginia. This meeting is the second in a series of research theme-based Contractors Meetings sponsored by DMS&E held in conjunction with our counterparts in the Office of Energy Efficiency and Renewable Energy (EERE) and the first with the Hydrogen, Fuel Cells and Infrastructure Technologies Program. The focus of this year’s meeting is BES funded fundamental research underpinning advancement of hydrogen storage. The major goals of these research efforts are the development of a fundamental scientific base in terms of new concepts, theories and computational tools; new characterization capabilities; and new materials that could be used or mimicked in advancing capabilities for hydrogen storage.

  16. Impact of phosphate on glyphosate uptake and toxicity in willow.

    Science.gov (United States)

    Gomes, Marcelo Pedrosa; Le Manac'h, Sarah Gingras; Moingt, Matthieu; Smedbol, Elise; Paquet, Serge; Labrecque, Michel; Lucotte, Marc; Juneau, Philippe

    2016-03-05

    Phosphate (PO4(3-)) has been shown to increase glyphosate uptake by willow, a plant species known for its phytoremediation potential. However, it remains unclear if this stimulation of glyphosate uptake can result in an elevated glyphosate toxicity to plants (which could prevent the use of willows in glyphosate-remediation programs). Consequently, we studied the effects of PO4(3-) on glyphosate uptake and toxicity in a fast growing willow cultivar (Salix miyabeana SX64). Plants were grown in hydroponic solution with a combination of glyphosate (0, 0.001, 0.065 and 1 mg l(-1)) and PO4(3-) (0, 200 and 400 mg l(-1)). We demonstrated that PO4(3-) fertilization greatly increased glyphosate uptake by roots and its translocation to leaves, which resulted in increased shikimate concentration in leaves. In addition to its deleterious effects in photosynthesis, glyphosate induced oxidative stress through hydrogen peroxide accumulation. Although it has increased glyphosate accumulation, PO4(3-) fertilization attenuated the herbicide's deleterious effects by increasing the activity of antioxidant systems and alleviating glyphosate-induced oxidative stress. Our results indicate that in addition to the glyphosate uptake, PO4(3-) is involved in glyphosate toxicity in willow by preventing glyphosate induced oxidative stress.

  17. Phosphate recovery as struvite within a single chamber microbial electrolysis cell

    KAUST Repository

    Cusick, Roland D.

    2012-03-01

    An energy efficient method of concurrent hydrogen gas and struvite (MgNH 4PO 4·6H 2O) production was investigated based on bioelectrochemically driven struvite crystallization at the cathode of a single chamber microbial electrolysis struvite-precipitation cell (MESC). The MESC cathodes were either stainless steel 304 mesh or flat plates. Phosphate removal ranged from 20% to 40%, with higher removals obtained using mesh cathodes than with flat plates. Cathode accumulated crystals were verified as struvite using a scanning electron microscope capable of energy dispersive spectroscopy (SEM-EDS). Crystal accumulation did not affect the rate of hydrogen production in struvite reactors. The rate of struvite crystallization (g/m 2-h) and hydrogen production (m 3/m 3-d) were shown to be dependent on applied voltage and cathode material. Overall energy efficiencies (substrate and electricity) were high (73±4%) and not dependent on applied voltage. These results show that MESCs may be useful both as a method for hydrogen gas and struvite production. © 2011 Elsevier Ltd.

  18. Phosphate recovery as struvite within a single chamber microbial electrolysis cell.

    Science.gov (United States)

    Cusick, Roland D; Logan, Bruce E

    2012-03-01

    An energy efficient method of concurrent hydrogen gas and struvite (MgNH(4)PO(4)·6H(2)O) production was investigated based on bioelectrochemically driven struvite crystallization at the cathode of a single chamber microbial electrolysis struvite-precipitation cell (MESC). The MESC cathodes were either stainless steel 304 mesh or flat plates. Phosphate removal ranged from 20% to 40%, with higher removals obtained using mesh cathodes than with flat plates. Cathode accumulated crystals were verified as struvite using a scanning electron microscope capable of energy dispersive spectroscopy (SEM-EDS). Crystal accumulation did not affect the rate of hydrogen production in struvite reactors. The rate of struvite crystallization (g/m(2)-h) and hydrogen production (m(3)/m(3)-d) were shown to be dependent on applied voltage and cathode material. Overall energy efficiencies (substrate and electricity) were high (73 ± 4%) and not dependent on applied voltage. These results show that MESCs may be useful both as a method for hydrogen gas and struvite production.

  19. Thermal stability of hydroxyapatite in biphasic calcium phosphate ceramics

    CSIR Research Space (South Africa)

    Nilen, RWN

    2008-04-01

    Full Text Available Biphasic calcium phosphate ceramics (BCP) comprising a mix of non-resorbable hydroxyapatite (HA) and resorbable b-tricalcium phosphate (b-TCP) are particularly suitable materials for synthetic bone substitute applications. In this study, HA...

  20. Calcium phosphate saturation in the western Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Naik, S.; Reddy, C.V.G.

    Temperature, inorganic phosphate concentration and pH seem to be the major factors influencing the degree of saturation of calcium phosphate in sea water. Two water regions can be demarcated in the study area based on the saturation patterns...

  1. Effect of aluminium phosphate as admixture on oxychloride cement

    Indian Academy of Sciences (India)

    M P S Chandrawat; R N Yadav

    2000-02-01

    The effect of admixing of aluminium phosphate on oxychloride cement in the matrix has been investigated. It is shown that aluminium phosphate retards the setting process of the cement and improves water-tightness.

  2. Calcium phosphate saturation in seawater around the Andaman Island

    Digital Repository Service at National Institute of Oceanography (India)

    Naik, S.; Reddy, C.V.G.

    Ionic product (IP) of calcium phosphate is calculated at some stations around Andaman Island. The depthwise variations of the ionic product of calcium phosphate seem to follow a normal trend with maximum saturation value between 100 to 200 m. Using...

  3. MEASURED AND PREFORMED PHOSPHATE IN THE GULF OF MEXICO REGION.

    Science.gov (United States)

    Measured and preformed phosphate-phosphorous versus depth are presented for three recent cruises to the Gulf of Mexico region. Phosphate...are discussed for a hypothetical idealized station in the Gulf of Mexico . (Author)

  4. Iron phosphate glass containing simulated fast reactor waste: Characterization and comparison with pristine iron phosphate glass

    Science.gov (United States)

    Joseph, Kitheri; Asuvathraman, R.; Venkata Krishnan, R.; Ravindran, T. R.; Govindaraj, R.; Govindan Kutty, K. V.; Vasudeva Rao, P. R.

    2014-09-01

    Detailed characterization was carried out on an iron phosphate glass waste form containing 20 wt.% of a simulated nuclear waste. High temperature viscosity measurement was carried out by the rotating spindle method. The Fe3+/Fe ratio and structure of this waste loaded iron phosphate glass was investigated using Mössbauer and Raman spectroscopy respectively. Specific heat measurement was carried out in the temperature range of 300-700 K using differential scanning calorimeter. Isoconversional kinetic analysis was employed to understand the crystallization behavior of the waste loaded iron phosphate glass. The glass forming ability and glass stability of the waste loaded glass were also evaluated. All the measured properties of the waste loaded glass were compared with the characteristics of pristine iron phosphate glass.

  5. Performance analysis of magnesium phosphate cement mortar containing grinding dust

    OpenAIRE

    2009-01-01

    Magnesium phosphate cement materials are formed by reacting magnesium oxide with water-soluble phosphates such as monoammonium dihydrogen phosphate (ADP), which solidifies at ambient temperature through the formation of hydrated phases in the material. Cylindrical specimens of magnesium phosphate cement were molded and varying amounts (0 to 30% weight) of grinding dust were added to the ceramic matrices. The influence of the addition of grinding dust on the characteristics of the mortars in t...

  6. Novel phosphate-based cements for clinical applications

    OpenAIRE

    2012-01-01

    This Thesis aims at the development of two novel families of inorganic phosphate cements with suitable characteristics for clinical applications in hard tissue regeneration or replacement. It is organized in two distinct parts. The first part focuses at the development of silicon-doped a-tricalcium phosphate and the subsequent preparation of a silicon-doped calcium phosphate cement for bone regeneration applications. For this purpose, silicon-doped a-tricalcium phosphate was synthesized b...

  7. Magnesium for Hydrogen Storage

    DEFF Research Database (Denmark)

    Pedersen, Allan Schrøder; Kjøller, John; Larsen, B.

    1983-01-01

    A study of the hydrogenation characteristics of fine magnesium powder during repeated cycling has been performed using a high-pressure microbalance facility. No effect was found from the cycling regarding kinetics and storage capacity. The reaction rate of the absorption process was fast at tempe......A study of the hydrogenation characteristics of fine magnesium powder during repeated cycling has been performed using a high-pressure microbalance facility. No effect was found from the cycling regarding kinetics and storage capacity. The reaction rate of the absorption process was fast...... at temperatures around 600 K and above, but the reversed reaction showed somewhat slower kinetics around 600 K. At higher temperatures the opposite was found. The enthalpy and entropy change by the hydrogenation, derived from pressure-concentration isotherms, agree fairly well with those reported earlier....

  8. Conversion of Marine Structures to Calcium Phosphate Materials: Mechanisms of Conversion Using Two Different Phosphate Solutions

    OpenAIRE

    Macha, Innocent J.; Grossin, David; Ben-Nissan, Besim

    2016-01-01

    International audience; Marine structure, coralline materials were converted to calcium phosphate using twodifferent phosphate solutions. The aim was to study the conversion mechanisms under acidic andbasic environment at moderate conditions of temperature. Crystal growth and morphology ofconverted corals were characterized by XRD and SEM respectively. The results suggested thatunder acidic conditions (H3PO4), dissolution and precipitation control and direct the crystalformation and morpholog...

  9. Hydrogen vehicle fueling station

    Energy Technology Data Exchange (ETDEWEB)

    Daney, D.E.; Edeskuty, F.J.; Daugherty, M.A. [Los Alamos National Lab., NM (United States)] [and others

    1995-09-01

    Hydrogen fueling stations are an essential element in the practical application of hydrogen as a vehicle fuel, and a number of issues such as safety, efficiency, design, and operating procedures can only be accurately addressed by a practical demonstration. Regardless of whether the vehicle is powered by an internal combustion engine or fuel cell, or whether the vehicle has a liquid or gaseous fuel tank, the fueling station is a critical technology which is the link between the local storage facility and the vehicle. Because most merchant hydrogen delivered in the US today (and in the near future) is in liquid form due to the overall economics of production and delivery, we believe a practical refueling station should be designed to receive liquid. Systems studies confirm this assumption for stations fueling up to about 300 vehicles. Our fueling station, aimed at refueling fleet vehicles, will receive hydrogen as a liquid and dispense it as either liquid, high pressure gas, or low pressure gas. Thus, it can refuel any of the three types of tanks proposed for hydrogen-powered vehicles -- liquid, gaseous, or hydride. The paper discusses the fueling station design. Results of a numerical model of liquid hydrogen vehicle tank filling, with emphasis on no vent filling, are presented to illustrate the usefulness of the model as a design tool. Results of our vehicle performance model illustrate our thesis that it is too early to judge what the preferred method of on-board vehicle fuel storage will be in practice -- thus our decision to accommodate all three methods.

  10. Phosphate Rock Fertilizer in Acid Soil:Comparing Phosphate Extraction Methods for Measuring Dissolution

    Institute of Scientific and Technical Information of China (English)

    T.S.ANSUMANA-KAWA; WANGGUANGHUO

    1998-01-01

    Three phosphate extraction methods were used to investigate the dissolution,availability and transfo-mation of Kunyang phosphate rock(KPR) in two surface acid soils.Dissolution was determined by measuring the increase in the amounts of soluble and adsorbed inorganic phosphate fractions,and did not differ signifi-cantly among the three methods.Significant correlations were obtained among P fractions got by the three extraction methods.Dissolution continued until the end of the 90-day incubation period.At the end of the period,much of the applied phosphate recovered in both soils were in the Al- and Fe-P or in the hydroxide-and bicarbonate-extractable inorganic P fractions.The dissolution of KPR in the two soils was also similar: increased addition of phosphate rock resulted in decreased dissolution.The similarity in the order and extent of dissolution in the two soils was probably due to the similarity in each soil of several factors that are known to influence phosphate rock dissolution,namely low CEC,pH,P level,and base status;and high clay and free iron and aluminum oxide contents.The results suggested that KPR could be an aternative P source in the soils are not limiting.

  11. Phosphate-responsive promoter of a Pichia pastoris sodium phosphate symporter.

    Science.gov (United States)

    Ahn, Jungoh; Hong, Jiyeon; Park, Myongsoo; Lee, Hyeokweon; Lee, Eungyo; Kim, Chunsuk; Lee, Joohwan; Choi, Eui-sung; Jung, Joon-ki; Lee, Hongweon

    2009-06-01

    To develop a functional phosphate-regulated promoter in Pichia pastoris, a phosphate-responsive gene, PHO89, which encodes a putative sodium (Na(+))-coupled phosphate symporter, was isolated. Sequencing analyses revealed a 1,731-bp open reading frame encoding a 576-amino-acid polypeptide with 12 putative transmembrane domains. The properties of the PHO89 promoter (P(PHO89)) were investigated using a bacterial lipase gene as a reporter in 5-liter jar fermentation experiments. P(PHO89) was tightly regulated by phosphate and was highly activated when the cells were grown in a phosphate-limited external environment. Compared to translation elongation factor 1alpha and the glyceraldehyde-3-phosphate dehydrogenase promoter, P(PHO89) exhibited strong transcriptional activity with higher specific productivity (amount of lipase produced/cell/h). Furthermore, a cost-effective and simple P(PHO89)-based fermentation process was developed for industrial application. These results demonstrate the potential for efficient use of P(PHO89) for controlled production of recombinant proteins in P. pastoris.

  12. Polyhydride complexes for hydrogen storage

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, C.M. [Univ. of Hawaii, Honolulu, HI (United States)

    1995-09-01

    Polyhydride metal complexes are being developed for application in hydrogen storage. Efforts have focused on developing complexes with improved available hydrogen weight percentages. We have explored the possibility that complexes containing aromatic hydrocarbon ligands could store hydrogen at both the metal center and in the ligands. We have synthesized novel indenyl hydride complexes and explored their reactivity with hydrogen. The reversible hydrogenation of [IrH{sub 3}(PPh{sub 3})({eta}{sup 5}-C{sub 10}H{sub 7})]{sup +} has been achieved. While attempting to prepare {eta}{sup 6}-tetrahydronaphthalene complexes, we discovered that certain polyhydride complexes catalyze both the hydrogenation and dehydrogenation of tetrahydronaphthalene.

  13. Hydrogen production from microbial strains

    Science.gov (United States)

    Harwood, Caroline S; Rey, Federico E

    2012-09-18

    The present invention is directed to a method of screening microbe strains capable of generating hydrogen. This method involves inoculating one or more microbes in a sample containing cell culture medium to form an inoculated culture medium. The inoculated culture medium is then incubated under hydrogen producing conditions. Once incubating causes the inoculated culture medium to produce hydrogen, microbes in the culture medium are identified as candidate microbe strains capable of generating hydrogen. Methods of producing hydrogen using one or more of the microbial strains identified as well as the hydrogen producing strains themselves are also disclosed.

  14. Control of crystallinity and composition in calcium phosphate coatings

    Energy Technology Data Exchange (ETDEWEB)

    Cifuentes, M.; Cabanas, M.V.; Vallet-Regi, M. [Universidad Complutense de Madrid (Spain). Dept. de Quimica Inorganica y Bioinorganica

    2001-07-01

    Calcium phosphate coatings were prepared by the so-called pyrosol method. Both crystallinity and composition of obtained films can be controlled by modifying the composition of the precursor solution, surrounding atmosphere and substrate temperature. In this way, tricalcium phosphate, hydroxyapatite or biphasic hydroxyapatite/tricalcium phosphate with different crystallinity and microstructure have been prepared. (orig.)

  15. RAPID ASSOCIATION OF UNCONJUGATED BILIRUBIN WITH AMORPHOUS CALCIUM-PHOSPHATE

    NARCIS (Netherlands)

    VANDERVEERE, CN; SHOEMAKER, B; VANDERMEER, R; GROEN, AK; JANSEN, PLM; ELFERINK, RPJO

    1995-01-01

    The association of unconjugated bilirubin (UCB) with amorphous calcium phosphate was studied in vitro. To this end UCB, solubilized in different micellar bile salt solutions, was incubated with freshly prepared calcium phosphate precipitate. It was demonstrated that amorphous calcium phosphate (ACP)

  16. 40 CFR 721.3080 - Substituted phosphate ester (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Substituted phosphate ester (generic... Substances § 721.3080 Substituted phosphate ester (generic). (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified generically as a substituted phosphate...

  17. Osteoclastic resorption of biomimetic calcium phosphate coatings in vitro.

    NARCIS (Netherlands)

    Leeuwenburgh, S.C.G.; Layrolle, P.; Barrere, F.; Bruijn, J.G.M. de; Schoonman, J.; Blitterswijk, C.A. van; Groot, K. de

    2001-01-01

    A new biomimetic method for coating metal implants enables the fast formation of dense and homogeneous calcium phosphate coatings. Titanium alloy (Ti6Al4V) disks were coated with a thin, carbonated, amorphous calcium phosphate (ACP) by immersion in a saturated solution of calcium, phosphate, magnesi

  18. Determination of Phosphates by the Gravimetric Quimociac Technique

    Science.gov (United States)

    Shaver, Lee Alan

    2008-01-01

    The determination of phosphates by the classic quimociac gravimetric technique was used successfully as a laboratory experiment in our undergraduate analytical chemistry course. Phosphate-containing compounds are dissolved in acid and converted to soluble orthophosphate ion (PO[subscript 4][superscript 3-]). The soluble phosphate is easily…

  19. Phosphate-dependent root system architecture responses to salt stress

    NARCIS (Netherlands)

    Kawa, D.; Julkowska, M.M.; Montero Sommerfeld, H.; ter Horst, A.; Haring, M.A.; Testerink, C.

    2016-01-01

    Nutrient availability and salinity of the soil affect growth and development of plant roots. Here, we describe how phosphate availability affects root system architecture (RSA) of Arabidopsis and how phosphate levels modulate responses of the root to salt stress. Phosphate (Pi) starvation reduced ma

  20. 21 CFR 582.1781 - Sodium aluminum phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sodium aluminum phosphate. 582.1781 Section 582.1781 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Additives § 582.1781 Sodium aluminum phosphate. (a) Product. Sodium aluminum phosphate. (b) Conditions...

  1. 21 CFR 182.1781 - Sodium aluminum phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium aluminum phosphate. 182.1781 Section 182.1781 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Substances § 182.1781 Sodium aluminum phosphate. (a) Product. Sodium aluminum phosphate....

  2. 21 CFR 182.6085 - Sodium acid phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium acid phosphate. 182.6085 Section 182.6085 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD... Sodium acid phosphate. (a) Product. Sodium acid phosphate. (b) Conditions of use. This substance...

  3. 21 CFR 582.6215 - Monobasic calcium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Monobasic calcium phosphate. 582.6215 Section 582.6215 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED....6215 Monobasic calcium phosphate. (a) Product. Monobasic calcium phosphate. (b) Conditions of use....

  4. 21 CFR 522.1883 - Prednisolone sodium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Prednisolone sodium phosphate. 522.1883 Section... § 522.1883 Prednisolone sodium phosphate. (a) Specifications. Each milliliter of solution contains 20 milligrams (mg) prednisolone sodium phosphate (equivalent to 14.88 mg of prednisolone). (b) Sponsor. See...

  5. 21 CFR 582.6085 - Sodium acid phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sodium acid phosphate. 582.6085 Section 582.6085 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Sodium acid phosphate. (a) Product. Sodium acid phosphate. (b) Conditions of use. This substance...

  6. 21 CFR 184.1141b - Ammonium phosphate, dibasic.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ammonium phosphate, dibasic. 184.1141b Section 184... Listing of Specific Substances Affirmed as GRAS § 184.1141b Ammonium phosphate, dibasic. (a) Ammonium phosphate, dibasic ((NH4)2HPO4, CAS Reg. No. 7783-28-0) is manufactured by reacting ammonia with...

  7. 21 CFR 182.6215 - Monobasic calcium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Monobasic calcium phosphate. 182.6215 Section 182.6215 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED....6215 Monobasic calcium phosphate. (a) Product. Monobasic calcium phosphate. (b) Conditions of use....

  8. 21 CFR 582.5697 - Riboflavin-5-phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Riboflavin-5-phosphate. 582.5697 Section 582.5697 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5697 Riboflavin-5-phosphate. (a) Product. Riboflavin-5-phosphate. (b) Conditions of...

  9. Dominant oceanic bacteria secure phosphate using a large extracellular buffer.

    Science.gov (United States)

    Zubkov, Mikhail V; Martin, Adrian P; Hartmann, Manuela; Grob, Carolina; Scanlan, David J

    2015-07-22

    The ubiquitous SAR11 and Prochlorococcus bacteria manage to maintain a sufficient supply of phosphate in phosphate-poor surface waters of the North Atlantic subtropical gyre. Furthermore, it seems that their phosphate uptake may counter-intuitively be lower in more productive tropical waters, as if their cellular demand for phosphate decreases there. By flow sorting (33)P-phosphate-pulsed (32)P-phosphate-chased cells, we demonstrate that both Prochlorococcus and SAR11 cells exploit an extracellular buffer of labile phosphate up to 5-40 times larger than the amount of phosphate required to replicate their chromosomes. Mathematical modelling is shown to support this conclusion. The fuller the buffer the slower the cellular uptake of phosphate, to the point that in phosphate-replete tropical waters, cells can saturate their buffer and their phosphate uptake becomes marginal. Hence, buffer stocking is a generic, growth-securing adaptation for SAR11 and Prochlorococcus bacteria, which lack internal reserves to reduce their dependency on bioavailable ambient phosphate.

  10. Effective removal of methyl blue by fine-structured strontium and barium phosphate nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Fan, E-mail: zhangfan0128@njau.edu.cn [College of Science, Nanjing Agricultural University, Nanjing 210095 (China); Song, Weijie [Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Lan, Jing [College of Chemistry and Pharmaceutical Sciences, Qingdao Agricultural University, Qingdao 266109 (China)

    2015-01-30

    Graphical abstract: - Highlights: • SBP nanorods have been studied for removal of methyl blue from solutions. • The high adsorption capacity was calculated to be 1691.8 mg/g. • The equilibrium reached within 10 min and obeyed the pseudo-second-order kinetics. • The mechanism was the ionic interaction, hydrogen bonds and chemical precipitation. - Abstract: In this work, the composite of strontium phosphate and barium phosphate (called SBP) nanorods have been synthesized, characterized and studied for removal of methyl blue (MB). The effects of pH, temperature, contact time, initial dye concentration on removal of MB were studied in detail. Results suggest that pH and temperature were not critical limiting factors for the removal of MB. Reaching equilibrium was very rapid (within 10 min) and the high adsorption capacity of MB by SBP nanorods was 1691.8 mg/g at initial dye concentration of 2000 mg/L. The adsorption process obeyed the pseudo-second-order kinetics model and Langmuir isotherm model. Importantly, the mechanism contributed to the MB removal was proposed to be the ionic interaction and hydrogen bonds for low dye concentration, chemical precipitation for high dye concentration. It is predicted that the SBP nanorods being an effective adsorbent for elimination of MB from colored aqueous solutions.

  11. Photoelectrochemical Hydrogen Production

    CERN Document Server

    Krol, R van de

    2012-01-01

    Photoelectrochemical Hydrogen Production describes the principles and materials challenges for the conversion of sunlight into hydrogen through water splitting at a semiconducting electrode. Readers will find an analysis of the solid state properties and materials requirements for semiconducting photo-electrodes, a detailed description of the semiconductor/electrolyte interface, in addition to the photo-electrochemical (PEC) cell. Experimental techniques to investigate both materials and PEC device performance are outlined, followed by an overview of the current state-of-the-art in PEC materia

  12. Hydrogen peroxide catalytic decomposition

    Science.gov (United States)

    Parrish, Clyde F. (Inventor)

    2010-01-01

    Nitric oxide in a gaseous stream is converted to nitrogen dioxide using oxidizing species generated through the use of concentrated hydrogen peroxide fed as a monopropellant into a catalyzed thruster assembly. The hydrogen peroxide is preferably stored at stable concentration levels, i.e., approximately 50%-70% by volume, and may be increased in concentration in a continuous process preceding decomposition in the thruster assembly. The exhaust of the thruster assembly, rich in hydroxyl and/or hydroperoxy radicals, may be fed into a stream containing oxidizable components, such as nitric oxide, to facilitate their oxidation.

  13. Hydrogen bonded supramolecular materials

    CERN Document Server

    Li, Zhan-Ting

    2015-01-01

    This book is an up-to-date text covering topics in utilizing hydrogen bonding for constructing functional architectures and supramolecular materials. The first chapter addresses the control of photo-induced electron and energy transfer. The second chapter summarizes the formation of nano-porous materials. The following two chapters introduce self-assembled gels, many of which exhibit unique functions. Other chapters cover the advances in supramolecular liquid crystals and the versatility of hydrogen bonding in tuning/improving the properties and performance of materials. This book is designed

  14. Electrocatalysts for hydrogen energy

    CERN Document Server

    Losiewicz, Bozena

    2015-01-01

    This special topic volume deals with the development of novel solid state electrocatalysts of a high performance to enhance the rates of the hydrogen or oxygen evolution. It contains a description of various types of metals, alloys and composites which have been obtained using electrodeposition in aqueous solutions that has been identified to be a technologically feasible and economically superior technique for the production of the porous electrodes. The goal was to produce papers that would be useful to both the novice and the expert in hydrogen technologies. This volume is intended to be us

  15. The hydrogen hybrid option

    Energy Technology Data Exchange (ETDEWEB)

    Smith, J.R.

    1993-10-15

    The energy efficiency of various piston engine options for series hybrid automobiles are compared with conventional, battery powered electric, and proton exchange membrane (PEM) fuel cell hybrid automobiles. Gasoline, compressed natural gas (CNG), and hydrogen are considered for these hybrids. The engine and fuel comparisons are done on a basis of equal vehicle weight, drag, and rolling resistance. The relative emissions of these various fueled vehicle options are also presented. It is concluded that a highly optimized, hydrogen fueled, piston engine, series electric hybrid automobile will have efficiency comparable to a similar fuel cell hybrid automobile and will have fewer total emissions than the battery powered vehicle, even without a catalyst.

  16. Performance of flexible capacitors based on polypyrrole/carbon fiber electrochemically prepared from various phosphate electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Wei; Han, Gaoyi, E-mail: han_gaoyis@sxu.edu.cn; Chang, Yunzhen; Li, Miaoyu; Xiao, Yaoming, E-mail: ymxiao@sxu.edu.cn; Zhou, Haihan; Zhang, Ying; Li, Yanping

    2016-11-30

    Highlights: • PPy/CFs have been fabricated by electrodepositing polypyrrole on carbon fibers. • The electrolytes in deposition solution have effect on PPy/CFs’ capacitive behavior. • Cells of PPy/CFs obtained from NaH{sub 2}PO{sub 4} electrolyte has good stability in PVA/H{sub 3}PO{sub 4}. - Abstract: In order to investigate the influence of electrolytes in electro-deposition solution on the capacitive properties of polypyrrole (PPy), we have chosen phosphoric acid, phosphate, hydrogen phosphate and dihydrogen phosphate as electrolyte in deposition solution respectively and electrochemically deposited PPy on carbon fibers (CFs) via galvanostatic method. The morphologies of the PPy/CFs samples have been characterized by scanning electron microscope. The specific capacitance of PPy/CFs samples has been evaluated in different electrolytes through three-electrode test system. The assembled flexible capacitors by using PPy/CFs as electrodes and H{sub 3}PO{sub 4}/polyvinyl alcohol as gel electrolyte have been systematically measured by cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy. The results show that the electrochemical capacitors based on PPy/CFs prepared from deposition solution containing NaH{sub 2}PO{sub 4}·2H{sub 2}O electrolyte exhibit higher specific capacitance, flexibility and excellent stability (retaining 96.8% of initial capacitance after 13,000 cycles), and that three cells connected in series can power a light-emitting diode.

  17. Performance of flexible capacitors based on polypyrrole/carbon fiber electrochemically prepared from various phosphate electrolytes

    Science.gov (United States)

    Yuan, Wei; Han, Gaoyi; Chang, Yunzhen; Li, Miaoyu; Xiao, Yaoming; Zhou, Haihan; Zhang, Ying; Li, Yanping

    2016-11-01

    In order to investigate the influence of electrolytes in electro-deposition solution on the capacitive properties of polypyrrole (PPy), we have chosen phosphoric acid, phosphate, hydrogen phosphate and dihydrogen phosphate as electrolyte in deposition solution respectively and electrochemically deposited PPy on carbon fibers (CFs) via galvanostatic method. The morphologies of the PPy/CFs samples have been characterized by scanning electron microscope. The specific capacitance of PPy/CFs samples has been evaluated in different electrolytes through three-electrode test system. The assembled flexible capacitors by using PPy/CFs as electrodes and H3PO4/polyvinyl alcohol as gel electrolyte have been systematically measured by cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy. The results show that the electrochemical capacitors based on PPy/CFs prepared from deposition solution containing NaH2PO4·2H2O electrolyte exhibit higher specific capacitance, flexibility and excellent stability (retaining 96.8% of initial capacitance after 13,000 cycles), and that three cells connected in series can power a light-emitting diode.

  18. Amorphous cobalt potassium phosphate microclusters as efficient photoelectrochemical water oxidation catalyst

    Science.gov (United States)

    Zhang, Ye; Zhao, Chunsong; Dai, Xuezeng; Lin, Hong; Cui, Bai; Li, Jianbao

    2013-12-01

    A novel amorphous cobalt potassium phosphate hydrate compound (KCoPO4·H2O) is identified to be active photocatalyst for oxygen evolution reaction (OER) to facilitate hydrogen generation from water photolysis. It has been synthesized through a facile and cost-effective solution-based precipitation method using earth-abundant materials. Its highly porous structure and large surface areas are found to be responsible for the excellent electrochemical performance featuring a low OER onset at ˜550 mVSCE and high current density in alkaline condition. Unlike traditional cobalt-based spinel oxides (Co3O4, NiCo2O4) and phosphate (Co-Pi, Co(PO3)2) electrocatalysts, with proper energy band alignment for light-assisted water oxidation, cobalt potassium phosphate hydrate also exhibits robust visible-light response, generating a photocurrent density of ˜200 μA cm-2 at 0.7 VSCE. This catalyst could thus be considered as a promising candidate to perform photoelectrochemical water splitting.

  19. Synthesis and Electrochemical Performance of a Lithium Titanium Phosphate Anode for Aqueous Lithium-Ion Batteries

    KAUST Repository

    Wessells, Colin

    2011-01-01

    Lithium-ion batteries that use aqueous electrolytes offer safety and cost advantages when compared to today\\'s commercial cells that use organic electrolytes. The equilibrium reaction potential of lithium titanium phosphate is -0.5 V with respect to the standard hydrogen electrode, which makes this material attractive for use as a negative electrode in aqueous electrolytes. This material was synthesized using a Pechini type method. Galvanostatic cycling of the resulting lithium titanium phosphate showed an initial discharge capacity of 115 mAh/g and quite good capacity retention during cycling, 84% after 100 cycles, and 70% after 160 cycles at a 1 C cycling rate in an organic electrolyte. An initial discharge capacity of 113 mAh/g and capacity retention of 89% after 100 cycles with a coulombic efficiency above 98% was observed at a C/5 rate in pH -neutral 2 M Li2 S O4. The good cycle life and high efficiency in an aqueous electrolyte demonstrate that lithium titanium phosphate is an excellent candidate negative electrode material for use in aqueous lithium-ion batteries. © 2011 The Electrochemical Society.

  20. Arginine-phosphate salt bridges between histones and DNA: Intermolecular actuators that control nucleosome architecture

    Science.gov (United States)

    Yusufaly, Tahir I.; Li, Yun; Singh, Gautam; Olson, Wilma K.

    2014-10-01

    Structural bioinformatics and van der Waals density functional theory are combined to investigate the mechanochemical impact of a major class of histone-DNA interactions, namely, the formation of salt bridges between arginine residues in histones and phosphate groups on the DNA backbone. Principal component analysis reveals that the configurational fluctuations of the sugar-phosphate backbone display sequence-specific directionality and variability, and clustering of nucleosome crystal structures identifies two major salt-bridge configurations: a monodentate form in which the arginine end-group guanidinium only forms one hydrogen bond with the phosphate, and a bidentate form in which it forms two. Density functional theory calculations highlight that the combination of sequence, denticity, and salt-bridge positioning enables the histones to apply a tunable mechanochemical stress to the DNA via precise and specific activation of backbone deformations. The results suggest that selection for specific placements of van der Waals contacts, with high-precision control of the spatial distribution of intermolecular forces, may serve as an underlying evolutionary design principle for the structure and function of nucleosomes, a conjecture that is corroborated by previous experimental studies.

  1. Enhancement of carotenoid and chlorophyll content of an edible freshwater alga (Kai: Cladophora sp. by supplementary inorganic phosphate and investigation of its biomass production

    Directory of Open Access Journals (Sweden)

    Siripen Traichaiyaporn

    2012-01-01

    Full Text Available Enhancement of the carotenoid and chlorophyll content of an edible freshwater alga (Kai:Cladophora sp. by supplementary inorganic phosphate in canteen wastewater was investigated. Themass cultivation of the alga was conducted at ambient temperature and light intensity in dilutedcanteen wastewater enhanced with dipotassium hydrogen phosphate at 5-20 mg L-1. An increase intotal carotenoid and chlorophyll was observed. However, it had no effect on biomass production. Asa result of the algal cultivation, there was a dramatic improvement in the quality of canteen wastewater.

  2. 40 CFR 422.60 - Applicability; description of the sodium phosphates subcategory.

    Science.gov (United States)

    2010-07-01

    ... sodium phosphates subcategory. 422.60 Section 422.60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS PHOSPHATE MANUFACTURING POINT SOURCE CATEGORY Sodium Phosphates Subcategory § 422.60 Applicability; description of the sodium phosphates subcategory....

  3. Regional Consumer Hydrogen Demand and Optimal Hydrogen Refueling Station Siting

    Energy Technology Data Exchange (ETDEWEB)

    Melendez, M.; Milbrandt, A.

    2008-04-01

    Using a GIS approach to spatially analyze key attributes affecting hydrogen market transformation, this study proposes hypothetical hydrogen refueling station locations in select subregions to demonstrate a method for determining station locations based on geographic criteria.

  4. Infrared-spectroscopy analysis of zinc phosphate and nickel and manganese modified zinc phosphate coatings on electrogalvanized steel

    OpenAIRE

    Fernandes,Kirlene Salgado; Alvarenga,Evandro de Azevedo; Brandão, Paulo Roberto Gomes; Lins,Vanessa de Freitas Cunha

    2011-01-01

    Hopeite-type phosphate coatings in which zinc is partially replaced by other metals like manganese and nickel are of great interest for the automotive and home appliance industries. Such industries use phosphate conversion coatings on galvanized steels in association with cataphoretic electropainting. Zinc phosphates modified with manganese and nickel are isomorphic with the hopeite, and the phase identification using X-ray diffraction is difficult. In this paper, the phosphate coatings are i...

  5. Hydrogen Embrittlement of Structural Steels

    Energy Technology Data Exchange (ETDEWEB)

    Somerday, Brian P.; San Marchi, Christopher W

    2014-08-01

    Carbon-manganese steels are candidates for the structural materials in hydrogen gas pipelines; however, it is well known that these steels are susceptible to hydrogen embrittlement. Decades of research and industrial experience have established that hydrogen embrittlement compromises the structural integrity of steel components. This experience has also helped identify the failure modes that can operate in hydrogen containment structures. As a result, there are tangible ideas for managing hydrogen embrittlement in steels and quantifying safety margins for steel hydrogen containment structures. For example, fatigue crack growth aided by hydrogen embrittlement is a well-established failure mode for steel hydrogen containment structures subjected to pressure cycling. This pressure cycling represents one of the key differences in operating conditions between current hydrogen pipelines and those anticipated in a hydrogen delivery infrastructure. Applying structural integrity models in design codes coupled with measurement of relevant material properties allows quantification of the reliability/integrity of steel hydrogen pipelines subjected to pressure cycling. Furthermore, application of these structural integrity models is aided by the development of physics-based predictive models, which provide important insights such as the effects of microstructure on hydrogen-assisted fatigue crack growth. Successful implementation of these structural integrity and physics-based models enhances confidence in the design codes and enables decisions about materials selection and operating conditions for reliable and efficient steel hydrogen pipelines.

  6. Kinetics of phosphate absorption in lactating dairy cows after enteral administration of sodium phosphate or calcium phosphate salts.

    Science.gov (United States)

    Grünberg, Walter; Dobbelaar, Paul; Breves, Gerhard

    2013-09-28

    Hypophosphataemia is frequently encountered in dairy cows during early lactation. Although supplementation of P is generally recommended, controversy exists over the suitability of oral P supplementation in animals with decreased or absent rumen motility. Since the effects of transruminal P absorption and the reticular groove reflex on the absorption kinetics of P are not well understood, it is unclear in how far treatment efficacy of oral P supplementation is affected by decreased rumen motility. Phosphate absorption was studied in six phosphate-depleted dairy cows fitted with rumen cannulas and treated with test solutions containing either NaH2PO4 or CaHPO4 with acetaminophen. Each animal was treated orally, intraruminally and intra-abomasally in randomised order. Absorption kinetics of P were studied and compared with the absorption kinetics of acetaminophen, a marker substance only absorbed from the small intestine. Intra-abomasal treatment with NaH2PO4 resulted in the most rapid and highest peaks in plasma inorganic P (Pi) concentration. Oral and intraruminal administration of NaH2PO4 resulted in similar increases in plasma Pi concentration from 4 to 7 h in both groups. Treatment with NaH2PO4 caused more pronounced peaks in plasma Pi concentration compared with CaHPO4. Neither transruminal P absorption nor the reticular groove reflex affected P absorption kinetics as determined by comparing plasma concentration–time curves of P and acetaminophen after administration of 1M-phosphate salt solutions. It is concluded that oral treatment with NaH2PO4 but not CaHPO4 is effective in supplementing P in hypophosphataemic cows with adequate rumen motility. Decreased rumen motility is likely to hamper the efficacy of oral phosphate treatment.

  7. Application of potential phosphate-solubilizing bacteria and organic acids on phosphate solubilization from phosphate rock in aerobic rice.

    Science.gov (United States)

    Panhwar, Qurban Ali; Jusop, Shamshuddin; Naher, Umme Aminun; Othman, Radziah; Razi, Mohd Ismail

    2013-01-01

    A study was conducted at Universiti Putra Malaysia to determine the effect of phosphate-solubilizing bacteria (PSB) and organic acids (oxalic & malic) on phosphate (P) solubilization from phosphate rock (PR) and growth of aerobic rice. Four rates of each organic acid (0, 10, 20, and 30 mM), and PSB strain (Bacillus sp.) were applied to aerobic rice. Total bacterial populations, amount of P solubilization, P uptake, soil pH, and root morphology were determined. The results of the study showed significantly high P solubilization in PSB with organic acid treatments. Among the two organic acids, oxalic acid was found more effective compared to malic acid. Application of oxalic acid at 20 mM along with PSB16 significantly increased soluble soil P (28.39 mg kg(-1)), plant P uptake (0.78 P pot(-1)), and plant biomass (33.26 mg). Addition of organic acids with PSB and PR had no influence on soil pH during the planting period. A higher bacterial population was found in rhizosphere (8.78 log10 cfu g(-1)) compared to the nonrhizosphere and endosphere regions. The application of organic acids along with PSB enhanced soluble P in the soil solution, improved root growth, and increased plant biomass of aerobic rice seedlings without affecting soil pH.

  8. Application of Potential Phosphate-Solubilizing Bacteria and Organic Acids on Phosphate Solubilization from Phosphate Rock in Aerobic Rice

    Directory of Open Access Journals (Sweden)

    Qurban Ali Panhwar

    2013-01-01

    Full Text Available A study was conducted at Universiti Putra Malaysia to determine the effect of phosphate-solubilizing bacteria (PSB and organic acids (oxalic & malic on phosphate (P solubilization from phosphate rock (PR and growth of aerobic rice. Four rates of each organic acid (0, 10, 20, and 30 mM, and PSB strain (Bacillus sp. were applied to aerobic rice. Total bacterial populations, amount of P solubilization, P uptake, soil pH, and root morphology were determined. The results of the study showed significantly high P solubilization in PSB with organic acid treatments. Among the two organic acids, oxalic acid was found more effective compared to malic acid. Application of oxalic acid at 20 mM along with PSB16 significantly increased soluble soil P (28.39 mg kg−1, plant P uptake (0.78 P pot−1, and plant biomass (33.26 mg. Addition of organic acids with PSB and PR had no influence on soil pH during the planting period. A higher bacterial population was found in rhizosphere (8.78 log10 cfu g−1 compared to the nonrhizosphere and endosphere regions. The application of organic acids along with PSB enhanced soluble P in the soil solution, improved root growth, and increased plant biomass of aerobic rice seedlings without affecting soil pH.

  9. The utilization of rock phosphate (natural defluorinated calcium phosphate or NDCP in laying hens diet to replace dicalcium phosphate

    Directory of Open Access Journals (Sweden)

    A.P Sinurat

    1996-06-01

    Full Text Available An experimentwas conducted to study the utilization of local rock phosphate or natural defluorinated calcium phosphate (NDCP as phosphorus source for layer chickens by using the imported dicalcium phosphate (DCP as a reference. Eight experimental diets consisted of 2 source of phosphorus (DCP and NDCP and 4 dietary total P levels (0.4, 0.5, 0.6 and 0.7% were formulated. Each diet was fed to 24 pullets (6 replicates with 4 birds each from 20 weeks of age to 14 weeks of egg production. Observations were made on feed consumption, egg production, egg weight, mortality, egg quality, Ca and P retention and ash content of tibial bones . Results showed no significant effect of different source and level of phosphorus tested on egg production (% HD, feed consumption, egg weight and mortality rates . Egg shell thickness was depressed in NDCP diet as compared with DCP, however this only occurred at firstmonth of production. It is concluded that the NDCP can be used in layers diet to replace DCP as phosphorus source. The relative biological value of phosphorus inNDCP is 96% for layers.

  10. Liquid Organic Hydrogen Carriers (LOHCs): Toward a Hydrogen-free Hydrogen Economy.

    Science.gov (United States)

    Preuster, Patrick; Papp, Christian; Wasserscheid, Peter

    2017-01-17

    The need to drastically reduce CO2 emissions will lead to the transformation of our current, carbon-based energy system to a more sustainable, renewable-based one. In this process, hydrogen will gain increasing importance as secondary energy vector. Energy storage requirements on the TWh scale (to bridge extended times of low wind and sun harvest) and global logistics of renewable energy equivalents will create additional driving forces toward a future hydrogen economy. However, the nature of hydrogen requires dedicated infrastructures, and this has prevented so far the introduction of elemental hydrogen into the energy sector to a large extent. Recent scientific and technological progress in handling hydrogen in chemically bound form as liquid organic hydrogen carrier (LOHC) supports the technological vision that a future hydrogen economy may work without handling large amounts of elemental hydrogen. LOHC systems are composed of pairs of hydrogen-lean and hydrogen-rich organic compounds that store hydrogen by repeated catalytic hydrogenation and dehydrogenation cycles. While hydrogen handling in the form of LOHCs allows for using the existing infrastructure for fuels, it also builds on the existing public confidence in dealing with liquid energy carriers. In contrast to hydrogen storage by hydrogenation of gases, such as CO2 or N2, hydrogen release from LOHC systems produces pure hydrogen after condensation of the high-boiling carrier compounds. This Account highlights the current state-of-the-art in hydrogen storage using LOHC systems. It first introduces fundamental aspects of a future hydrogen economy and derives therefrom requirements for suitable LOHC compounds. Molecular structures that have been successfully applied in the literature are presented, and their property profiles are discussed. Fundamental and applied aspects of the involved hydrogenation and dehydrogenation catalysis are discussed, characteristic differences for the catalytic conversion of

  11. Hydrogen fuel - Universal energy

    Science.gov (United States)

    Prince, A. G.; Burg, J. A.

    The technology for the production, storage, transmission, and consumption of hydrogen as a fuel is surveyed, with the physical and chemical properties of hydrogen examined as they affect its use as a fuel. Sources of hydrogen production are described including synthesis from coal or natural gas, biomass conversion, thermochemical decomposition of water, and electrolysis of water, of these only electrolysis is considered economicially and technologically feasible in the near future. Methods of production of the large quantities of electricity required for the electrolysis of sea water are explored: fossil fuels, hydroelectric plants, nuclear fission, solar energy, wind power, geothermal energy, tidal power, wave motion, electrochemical concentration cells, and finally ocean thermal energy conversion (OTEC). The wind power and OTEC are considered in detail as the most feasible approaches. Techniques for transmission (by railcar or pipeline), storage (as liquid in underwater or underground tanks, as granular metal hydride, or as cryogenic liquid), and consumption (in fuel cells in conventional power plants, for home usage, for industrial furnaces, and for cars and aircraft) are analyzed. The safety problems of hydrogen as a universal fuel are discussed, noting that they are no greater than those for conventional fuels.

  12. Electrochemical Hydrogen Evolution

    DEFF Research Database (Denmark)

    Laursen, A.B.; Varela Gasque, Ana Sofia; Dionigi, F.

    2012-01-01

    The electrochemical hydrogen evolution reaction (HER) is growing in significance as society begins to rely more on renewable energy sources such as wind and solar power. Thus, research on designing new, inexpensive, and abundant HER catalysts is important. Here, we describe how a simple experimen...

  13. A Simple Hydrogen Electrode

    Science.gov (United States)

    Eggen, Per-Odd

    2009-01-01

    This article describes the construction of an inexpensive, robust, and simple hydrogen electrode, as well as the use of this electrode to measure "standard" potentials. In the experiment described here the students can measure the reduction potentials of metal-metal ion pairs directly, without using a secondary reference electrode. Measurements…

  14. Catalytic combustor for hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Mercea, J.; Grecu, E.; Fodor, T.; Kreibik, S.

    1982-01-01

    The performance of catalytic combustors for hydrogen using platinum-supported catalysts is described. Catalytic plates of different sizes were constructed using fibrous and ceramic supports. The temperature distribution as well as the reaction efficiency as a function of the fuel input rate was determined, and a comparison between the performances of different plates is discussed.

  15. Sustainable Electrochemical Hydrogen Production

    DEFF Research Database (Denmark)

    Kibsgaard, Jakob; Jaramillo, Thomas F.; Chorkendorff, Ib

    production is through electrochemical processes coupled to renewable energy sources such as wind or solar. The hydrogen evolution reaction (HER, 2H+ + 2e− → H2) constitutes half of the water splitting reaction. To increase process efficiency, active catalysts for the HER are needed. Currently platinum...

  16. A Simple Hydrogen Electrode

    Science.gov (United States)

    Eggen, Per-Odd

    2009-01-01

    This article describes the construction of an inexpensive, robust, and simple hydrogen electrode, as well as the use of this electrode to measure "standard" potentials. In the experiment described here the students can measure the reduction potentials of metal-metal ion pairs directly, without using a secondary reference electrode. Measurements…

  17. Hydrogen storage for automobiles

    Energy Technology Data Exchange (ETDEWEB)

    Strickland, G.

    1979-01-01

    Results of an analysis of hydrogen-fueled automobiles are presented as a part of a continuing study conducted by Lawrence Livermore Laboratory (LLL) on Energy Storage Systems for Automobile Propulsion. The hydrogen is stored either as a metal hydride at moderate pressure in TiFe/sub 0/ /sub 9/Mn/sub 0/ /sub 1/H/sub x/ and at low pressure in MgH/sub x/ catalyzed with 10 wt % Ni, or it is stored in hollow glass microspheres at pressures up to about 400 atm. Improved projections are given for the two hydrides, which are used in combination to take advantage of their complementary properties. In the dual-hydride case and in the microsphere case where Ti-based hydride is used for initial operation, hydrogen is consumed in an internal-combustion engine; whereas in the third case, hydrogen from Ti-based hydride is used with air in an alkaline fuel cell/Ni-Zn battery combination which powers an electric vehicle. Each system is briefly described; and the results of the vehicle analysis are compared with those for the conventional automobile and with electric vehicles powered by Pb-acid or Ni-Zn batteries. Comparisons are made on the basis of automobile weight, initial user cost, and life-cycle cost. In this report, the results are limited to those for the 5-passenger vehicle in the period 1985-1990, and are provided as probable and optimistic values.

  18. Oxidation resistant organic hydrogen getters

    Science.gov (United States)

    Shepodd, Timothy J.; Buffleben, George M.

    2008-09-09

    A composition for removing hydrogen from an atmosphere, comprising a mixture of a polyphenyl ether and a hydrogenation catalyst, preferably a precious metal catalyst, and most preferably Pt. This composition is stable in the presence of oxygen, will not polymerize or degrade upon exposure to temperatures in excess of 200.degree. C., or prolonged exposure to temperatures in the range of 100-300.degree. C. Moreover, these novel hydrogen getter materials can be used to efficiently removing hydrogen from mixtures of hydrogen/inert gas (e.g., He, Ar, N.sub.2), hydrogen/ammonia atmospheres, such as may be encountered in heat exchangers, and hydrogen/carbon dioxide atmospheres. Water vapor and common atmospheric gases have no adverse effect on the ability of these getter materials to absorb hydrogen.

  19. Hydrogen Storage Technical Team Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    None

    2013-06-01

    The mission of the Hydrogen Storage Technical Team is to accelerate research and innovation that will lead to commercially viable hydrogen-storage technologies that meet the U.S. DRIVE Partnership goals.

  20. Trends in Hydrogen Vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Hoevenaars, A.J.; Weeda, M. [ECN Hydrogen and Clean Fossil Fuels, Petten (Netherlands)

    2009-09-15

    This report intends to provide an update of the latest developments that have recently occurred within car industry within the field of Hydrogen powered fuel cell vehicles (FCVs) to date, October 2009. In attempts to provide a clear and logical overview, the report starts with an overview of the OEMs (Original Equipment Manufacturers) that are actually active within the Hydrogen vehicle business, and provides an overview of the intensity of FCV activity per OEM. This overview shows that there is a pool of distinctively most active OEMs, and that others have tried to create exposure for themselves, but have not seriously been involved in in-house technology development in support of FCV manufacturing. Furthermore, some manufacturers chose a different path when it comes to using hydrogen for vehicle propulsion and use Hydrogen gas as a fuel for a conventional Internal Combustion Engine (ICE). In the field of FCVs, Most FCV activities are displayed by Honda, Daimler, Opel/GM, Hyundai/Kia, Toyota, Nissan and Ford. Volkswagen has given less priority to FCV development and has not been profiling itself as a very Hydrogen-prone OEM. Mazda and BMW chose to put their efforts in the development of Hydrogen fuelled ICE vehicles. Also Ford has put efforts in Hydrogen fuelled ICE vehicles. After the active OEMs are mapped, an overview is given on how active they have been in terms of cars produced. It appeared difficult to come up with reliable estimations on the basis of numbers available for public. The sum of vehicles produced by all OEMs together was estimated on about 515 vehicles. This estimation however was much lower than the figures published by Fuel Cell Today (FCT). FCT projects accumulated vehicles shipped in 2009 around 1100 units, the double of the numbers found for this study. Communication with FCT learned us that FCT has access to confidential information from the OEMs. Especially the Asian OEMs do not provide transparency when it comes to FCVs shipped, however

  1. Seed selections for crystallization of calcium phosphate for phosphorus recovery

    Institute of Scientific and Technical Information of China (English)

    SONG Yong-hui; Dietfried DONNERT; Ute BERG; Peter G. WEIDLER; Rolf NUEESCH

    2007-01-01

    Seed induces and promotes the crystallization of calcium phosphate, and acts as carrier of the recovered phosphorus (P). In order to select suitable seed for P recovery from wastewater, three seeds including Apatite (AP), Juraperle (JP) and phosphate-modified Juraperle (M-JP) were tested and compared. Batch and fixed-bed column experiments of seeded crystallization of calcium phosphate were undertaken by using synthetic wastewater with 10 mg/L P phosphate. It shows that AP has bad enduring property in the crystallization process, while JP has better performance for multiple uses, and M-JP is a hopeful seed for P recovery by crystallization of calcium phosphate.

  2. Performance analysis of magnesium phosphate cement mortar containing grinding dust

    Directory of Open Access Journals (Sweden)

    Daniel Véras Ribeiro

    2009-03-01

    Full Text Available Magnesium phosphate cement materials are formed by reacting magnesium oxide with water-soluble phosphates such as monoammonium dihydrogen phosphate (ADP, which solidifies at ambient temperature through the formation of hydrated phases in the material. Cylindrical specimens of magnesium phosphate cement were molded and varying amounts (0 to 30% weight of grinding dust were added to the ceramic matrices. The influence of the addition of grinding dust on the characteristics of the mortars in terms of microstructure (SEM, mechanical strength and capillary water absorption was verified. The results obtained proved very satisfactory for the use of this waste as an additive in magnesium phosphate mortars.

  3. Biomimetic Production of Hydrogen

    Science.gov (United States)

    Gust, Devens

    2004-03-01

    The basic reaction for hydrogen generation is formation of molecular hydrogen from two electrons and two protons. Although there are many possible sources for the protons and electrons, and a variety of mechanisms for providing the requisite energy for hydrogen synthesis, the most abundant and readily available source of protons and electrons is water, and the most attractive source of energy for powering the process is sunlight. Not surprisingly, living systems have evolved to take advantage of these sources for materials and energy. Thus, biology provides paradigms for carrying out the reactions necessary for hydrogen production. Photosynthesis in green plants uses sunlight as the source of energy for the oxidation of water to give molecular oxygen, protons, and reduction potential. Some photosynthetic organisms are capable of using this reduction potential, in the form of the reduced redox protein ferredoxin, to reduce protons and produce molecular hydrogen via the action of an hydrogenase enzyme. A variety of other organisms metabolize the reduced carbon compounds that are ultimately the major products of photosynthesis to produce molecular hydrogen. These facts suggest that it might be possible to use light energy to make molecular hydrogen via biomimetic constructs that employ principles similar to those used by natural organisms, or perhaps with hybrid "bionic" systems that combine biomimetic materials with natural enzymes. It is now possible to construct artificial photosynthetic systems that mimic some of the major steps in the natural process.(1) Artificial antennas based on porphyrins, carotenoids and other chromophores absorb light at various wavelengths in the solar spectrum and transfer the harvested excitation energy to artificial photosynthetic reaction centers.(2) In these centers, photoinduced electron transfer uses the energy from light to move an electron from a donor to an acceptor moiety, generating a high-energy charge-separated state

  4. Infrared and Raman spectroscopic characterization of the phosphate mineral fairfieldite--Ca2(Mn2+,Fe2+)2(PO4)2·2(H2O).

    Science.gov (United States)

    Frost, Ray L; Xi, Yunfei; Scholz, Ricardo; Belotti, Fernanda Maria; Lopez, Andres

    2013-04-01

    Raman spectroscopy complimented with infrared spectroscopy has been used to determine the molecular structure of the phosphate mineral fairfieldite. The Raman phosphate (PO4)(3-) stretching region shows strong differences between the fairfieldite phosphate minerals which is attributed to the cation substitution for calcium in the structure. In the infrared spectra complexity exists with multiple (PO4)2- antisymmetric stretching vibrations observed, indicating a reduction of the tetrahedral symmetry. This loss of degeneracy is also reflected in the bending modes. Strong Raman bands around 600 cm(-1) are assigned to ν4 phosphate bending modes. Multiple bands in the 400-450 cm(-1) region assigned to ν2 phosphate bending modes provide further evidence of symmetry reduction of the phosphate anion. Three broadbands for fairfieldite are found at 3040, 3139 and 3271 cm(-1) and are assigned to OH stretching bands. By using a Libowitzky empirical equation hydrogen bond distances of 2.658 and 2.730Å are estimated. Vibrational spectroscopy enables aspects of the molecular structure of the fairfieldite to be ascertained. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Saga of hydrogen civilization

    Energy Technology Data Exchange (ETDEWEB)

    Veziroglu, T.N. [Clean Energy Research Inst., Univ. of Miami, Coral Gables, Florida (United States)

    2009-07-01

    'Full text': Fossil fuels (i.e., petroleum, natural gas and coal), which meet most of the world's energy demand today, are being depleted quickly. Also, their combustion products are causing global problems such as the greenhouse effect, ozone layer depletion, acid rains and pollution, all of which are posing great danger for our environment and eventually for the life on our planet. Many engineers and scientists agree that the solution to these global problems would be to replace the existing fossil fuel system by the hydrogen energy system. Hydrogen is a very efficient and clean fuel. Its combustion will produce no greenhouse gases, no ozone layer depleting chemicals, and little or no acid rain ingredients and pollution. Hydrogen, produced from renewable energy (e.g., solar) sources, would result in a permanent energy system which we would never have to change. However, there are other energy systems proposed for the post-petroleum era, such as a synthetic fossil fuel system. In this system, synthetic gasoline and synthetic natural gas will be produced using abundant deposits of coal. In a way, this will ensure the continuation of the present fossil fuel system. The two possible energy systems for the post-fossil fuel era (i.e., the solar-hydrogen energy system and the synthetic fossil fuel system) are compared with the present fossil fuel system by taking into consideration production costs, environmental damages and utilization efficiencies. The results indicate that the solar-hydrogen energy system is the best energy system to ascertain a sustainable future, and it should replace the fossil fuel system before the end of the 21st century. (author)

  6. Photovoltaic hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Hiser, H.W.; Memory, S.B.; Veziroglu, T.N.; Padin, J. [Univ. of Miami, Coral Gables, FL (United States)

    1996-10-01

    This is a new project, which started in June 1995, and involves photovoltaic hydrogen production as a fuel production method for the future. In order to increase the hydrogen yield, it was decided to use hybrid solar collectors to generate D.C. electricity, as well as high temperature steam for input to the electrolyzer. In this way, some of the energy needed to dissociate the water is supplied in the form of heat (or low grade energy), to generate steam, which results in a reduction of electrical energy (or high grade energy) needed. As a result, solar to hydrogen conversion efficiency is increased. In the above stated system, the collector location, the collector tracking sub-system (i.e., orientation/rotation), and the steam temperature have been taken as variables. Five locations selected - in order to consider a variety of latitudes, altitudes, cloud coverage and atmospheric conditions - are Atlanta, Denver, Miami, Phoenix and Salt Lake City. Plain PV and hybrid solar collectors for a stationary south facing system and five different collector rotation systems have been analyzed. Steam temperatures have been varied between 200{degrees}C and 1200{degrees}C. During the first year, solar to hydrogen conversion efficiencies have been considered. The results show that higher steam temperatures, 2 dimensional tracking system, higher elevations and dryer climates causes higher conversion efficiencies. Cost effectiveness of the sub-systems and of the overall system will be analyzed during the second year. Also, initial studies will be made of an advanced high efficiency hybrid solar hydrogen production system.

  7. Task D: Hydrogen safety analysis

    Energy Technology Data Exchange (ETDEWEB)

    Swain, M.R.; Sievert, B.G. [Univ. of Miami, Coral Gables, FL (United States); Swain, M.N. [Analytical Technologies, Inc., Miami, FL (United States)

    1996-10-01

    This report covers two topics. The first is a review of codes, standards, regulations, recommendations, certifications, and pamphlets which address safety of gaseous fuels. The second is an experimental investigation of hydrogen flame impingement. Four areas of concern in the conversion of natural gas safety publications to hydrogen safety publications are delineated. Two suggested design criteria for hydrogen vehicle fuel systems are proposed. It is concluded from the experimental work that light weight, low cost, firewalls to resist hydrogen flame impingement are feasible.

  8. Recent progress in hydrogen storage

    Directory of Open Access Journals (Sweden)

    Ping Chen

    2008-12-01

    Full Text Available The ever-increasing demand for energy coupled with dwindling fossil fuel resources make the establishment of a clean and sustainable energy system a compelling need. Hydrogen-based energy systems offer potential solutions. Although, in the long-term, the ultimate technological challenge is large-scale hydrogen production from renewable sources, the pressing issue is how to store hydrogen efficiently on board hydrogen fuel-cell vehicles1,2.

  9. Hydrogen Fire Spectroscopy Issues Project

    Science.gov (United States)

    Youngquist, Robert C. (Compiler)

    2014-01-01

    The detection of hydrogen fires is important to the aerospace community. The National Aeronautics and Space Administration (NASA) has devoted significant effort to the development, testing, and installation of hydrogen fire detectors based on ultraviolet, near-infrared, mid-infrared, andor far-infrared flame emission bands. Yet, there is no intensity calibrated hydrogen-air flame spectrum over this range in the literature and consequently, it can be difficult to compare the merits of different radiation-based hydrogen fire detectors.

  10. Probing potential medium effects on phosphate ester bonds using 18O isotope shifts on 31P NMR.

    Science.gov (United States)

    Sorensen-Stowell, Kerensa; Hengge, Alvan C

    2005-10-14

    Dipolar aprotic cosolvents, such as DMSO and acetonitrile, accelerate the rates of hydrolysis of phosphate monoester dianions. It has been speculated that the rate acceleration arises from the disruption of hydrogen bonding to the phosphoryl group. An aqueous solvation shell can stabilize the dianionic phosphoryl group by forming hydrogen bonds to the phosphoryl oxygens, whereas solvents such as DMSO are incapable of forming such bonds. It has been proposed that the loss of stabilization could result in a weakened P-OR ester bond, contributing to the observed faster rate of hydrolysis. Computational results support this notion. We have used the 18O-induced perturbation to the 31P chemical shift to ascertain whether solvent changes result in alterations to the P-O(R) bond. We have studied 16O18O-labeled methyl, ethyl, phenyl, p-nitrophenyl, diethyl p-nitrophenyl, triphenyl, and di-tert-butyl ethyl phosphate in the solvents water, methanol, chloroform, acetonitrile, dioxane, and DMSO. The results suggest no significant solvent-induced weakening of the phosphate ester bonds in any of the solvents tested, and this is unlikely to be a significant source for the acceleration of hydrolysis in mixed solvents.

  11. Aluminum phosphate ceramics for waste storage

    Science.gov (United States)

    Wagh, Arun; Maloney, Martin D

    2014-06-03

    The present disclosure describes solid waste forms and methods of processing waste. In one particular implementation, the invention provides a method of processing waste that may be particularly suitable for processing hazardous waste. In this method, a waste component is combined with an aluminum oxide and an acidic phosphate component in a slurry. A molar ratio of aluminum to phosphorus in the slurry is greater than one. Water in the slurry may be evaporated while mixing the slurry at a temperature of about 140-200.degree. C. The mixed slurry may be allowed to cure into a solid waste form. This solid waste form includes an anhydrous aluminum phosphate with at least a residual portion of the waste component bound therein.

  12. Preparation and characterization of calcium phosphate biomaterials.

    Science.gov (United States)

    Calafiori, A R; Di Marco, G; Martino, G; Marotta, M

    2007-12-01

    Calcium phosphate cement (CPC) samples have been prepared with a mixture of monocalciumphosphate monohydrate (MCPM) and calcium carbonate (CC) powders, in stechiometric moles ratio 1:2.5 to obtain a Ca/P ratio of about 1.67 typical of hydroxyapatite (HAp), with or without addition of HAp. All specimens are incubated at 30 degrees C in a steam saturated air environment for 3, 6 and 15 days respectively, afterwards dried and stored under nitrogen. The calcium phosphate samples have been characterized by X-ray diffraction (XRD), Vickers hardness test (HV), diametral compression (d.c.), strength compression, and porosity evaluation. MCPM/CC mixture has a 30% HAp final concentration and is characterized by higher porosity (amount 78%) and mechanical properties useful as filler in bone segments without high mechanical stress.

  13. Infrared spectroscopy of different phosphates structures.

    Science.gov (United States)

    Jastrzębski, W; Sitarz, M; Rokita, M; Bułat, K

    2011-08-15

    Infrared (IR) spectroscopic studies of mineral and synthetic phosphates have been presented. The interpretation of the spectra has been preceded by the isolated [PO(4)](3-) tetrahedron spectra analyse. The K(3)PO(4) saturated aqueous solution was measured in the special cell for liquids. The obtained IR results have been compared with the theoretical number of IR-active modes. The number and positions of the bands due to P-O vibrations have been established. The phase composition of the phosphates has been determined using XRD and IR spectroscopy methods. The influence of non-tetrahedral cations on the shape of the spectra and the positions of bands has been analysed and the crystalline field splitting effect has been discussed.

  14. Polyhexanide and hydrogen peroxide inhibit proteoglycan synthesis of human chondrocytes.

    Science.gov (United States)

    Röhner, Eric; Hoff, Paula; Winkler, Tobias; von Roth, Philipp; Seeger, Jörn Bengt; Perka, Carsten; Matziolis, Georg

    2011-03-01

    The use of local antiseptics is a common method in septic joint surgery. We tested polyhexanide and hydrogen peroxide, two of the most frequently used antiseptics with high efficacy and low toxicity. The purpose of this study was to evaluate the effects of both antiseptics on the extracellular cartilaginous matrix synthesis of human chondrocytes. Chondrocytes were isolated from donated human knee joints, embedded in alginate beads, and incubated for 10 and 30 minutes with polyhexanide (0.04%), hydrogen peroxide (3%), or phosphate-buffered saline (PBS) for control. Cartilaginous matrix production was quantified through light microscopic analysis of Alcian blue staining. Cell number and morphology were detected by histological analysis. Chondrocytes showed a decreased intensity of blue colouring after antiseptic treatment versus PBS. In contrast to that, neither the cell number per view field nor the cell morphology differed between the groups. Polyhexanide has more toxic potential than hydrogen peroxide. Based on the fact that the cell number and morphology was not altered by the substances at the examined concentrations, the lower intensity of Alcian blue staining of treated chondrocytes indicates a decreased cartilage-specific matrix synthesis by polyhexanide more than by hydrogen peroxide and control.

  15. Zinc phosphating of 6061-Al alloy using REN as additive

    Institute of Scientific and Technical Information of China (English)

    ZHANG Shenglin; ZHANG Xiaolin; ZHANG Mingming

    2008-01-01

    Zinc phosphate coating formed on 6061-Al alloy was studied with the help of electrochemical measurements, Fourier Transform Infrared (FTIR), and Scanning Electron Microscopy (SEM), after dipping it in phosphating solutions containing different concentrations of Rare Earth Nitrate (REN). REN, which acted as an accelerator in the phosphating solution, could catalyze the surface reaction and accelerate the phosphating process. REN mainly enabled the P in the phosphate coating to exist in the form of PO43- and promoted the hydrolysis of phosphatic acid in a liquid layer at the cathodes. This resulted in the evolution of H2 at the cathodes, which increased the local pH value and in turn drove the precipitation of the phosphate coating. Additionally, REN was adsorbed on the surface of the aluminum substrates to form a gel during the phosphating process. These gel particles were good crystal seeds, which helped to form phosphate crystal nuclei and possess the function of a nucleation agent that could decrease the phosphate crystal size. The corrosion resistance of the formed zinc phosphate coatings was improved.

  16. Co-adsorption of perfluorooctane sulfonate and phosphate on boehmite: Influence of temperature, phosphate initial concentration and pH.

    Science.gov (United States)

    Qian, Jin; Shen, Mengmeng; Wang, Peifang; Wang, Chao; Hu, Jing; Hou, Jun; Ao, Yanhui; Zheng, Hao; Li, Kun; Liu, Jingjing

    2017-03-01

    The co-presence of perfluorooctane sulfonate (PFOS) and phosphate in wastewater of various industries has been detected. Removing PFOS and phosphate simultaneously before discharging sewage into natural water can decrease effectively the environmental risk caused by the combined pollution of PFOS and phosphate. In this study, laboratory batch experiments were conducted for investigating the co-adsorption of PFOS and phosphate on boehmite and the influences of temperature, phosphate initial concentration and pH on the co-adsorption. The adsorption thermodynamics and kinetics of PFOS and phosphate on boehmite were also investigated completely and systematically. The results showed that lower temperature favored the co-adsorptions of PFOS and phosphate. The adsorption of PFOS and phosphate on boehmite agreed well with the Langmuir isotherm and the adsorption parameters of thermodynamics are ΔH=-16.9 and -20.0kJmol(-1) (PFOS and phosphate), ΔS=-5.69 and -7.63Jmol(-1) K(-1) (PFOS and phosphate) and ΔG adsorption of PFOS and phosphate on boehmite is a spontaneously exothermic process. Moreover, the co-adsorption process can be described well by a pseudo-second-order kinetic model. With increasing phosphate initial concentration, more phosphate could be adsorbed on boehmite, while the adsorption of PFOS decreased at phosphate initial concentration of less than 30mgL(-1) and increased at that of larger than 30mgL(-1). In the co-adsorption process, the adsorption amount of PFOS decreased with pH increasing, but that of phosphate changed little.

  17. Simulating pH and hydrogen sulfide in a distributed collection system

    DEFF Research Database (Denmark)

    Vollertsen, Jes; Le Guennec, Anne; Nielsen, Asbjørn Haaning

    2013-01-01

    , and ventilation. The presented concept includes the major buffer systems, namely carbonate, ammonia, amine groups, hydrogen sulfides, phosphates, acetic acid, and propionic acid. It furthermore includes water-gas mass transfer between phases and ventilation of sewer gas into the urban atmosphere. The model....... The pH decreased from 7.80 of fresh wastewater entering the nodes to 7.30 at the treatment plant. This decrease could be attributed to the processes of anaerobic fermentation and hydrogen sulfide formation in the network....

  18. Removal of phosphate from aqueous solution with blast furnace slag.

    Science.gov (United States)

    Oguz, Ensar

    2004-10-18

    Blast furnace slag was used to remove phosphate from aqueous solutions. The influence of pH, temperature, agitation rate, and blast furnace slag dosage on phosphate removal was investigated by conducting a series of batch adsorption experiments. In addition, the yield and mechanisms of phosphate removal were explained on the basis of the results of X-ray spectroscopy, measurements of zeta potential of particles, specific surface area, and images of scanning electron microscopy (SEM) of the particles before and after adsorption. The specific surface area of the blast furnace slag was 0.4m(2)g(-1). The removal of phosphate predominantly has taken place by a precipitation mechanism and weak physical interactions between the surface of adsorbent and the metallic salts of phosphate. In this study, phosphate removal in excess of 99% was obtained, and it was concluded that blast furnace slag is an efficient adsorbent for the removal of phosphate from solution.

  19. Phosphate sensing and signalling in Arabidopsis thaliana

    OpenAIRE

    2013-01-01

    Phosphate (Pi) deficiency is a global problem for food production. Plants have evolved complex mechanisms to adapt to low Pi. We focused on the initial aspects of adaptation to low Pi - perception and immediate-early responses to changes in external Pi. To examine whether a labile repressor controls expression of the high affinity Pi transporter, Pht1;1, we performed electrophoretic mobility shift assays (EMSA) but observed only weak protein-DNA binding activity using extrac...

  20. HYDROGEN VACANCY INTERACTION IN MOLYBDENUM

    NARCIS (Netherlands)

    Abd El Keriem, M.S.; van der Werf, D.P.; Pleiter, F

    1993-01-01

    Vacancy-hydrogen interaction in molybdenum was investigated by means of the perturbed angular correlation technique, using the isotope In-111 as a probe. The complex InV2 turned out to trap up to two hydrogen atoms: trapping of a single hydrogen atom gives rise to a decrease of the quadrupole

  1. Single element hydrogen sensing material

    NARCIS (Netherlands)

    Dam, B.; Boelsma, C.

    2015-01-01

    The present invention relates to a single element thin-film device, to a method for producing a thin-film device, to a single element for detecting hydrogen absorption, to a hydrogen sensor, to an apparatus for detecting hydrogen and to an electro-magnetic transformer comprising said sensor. A thin-

  2. Hydrogen storage: beyond conventional methods.

    Science.gov (United States)

    Dalebrook, Andrew F; Gan, Weijia; Grasemann, Martin; Moret, Séverine; Laurenczy, Gábor

    2013-10-09

    The efficient storage of hydrogen is one of three major hurdles towards a potential hydrogen economy. This report begins with conventional storage methods for hydrogen and broadly covers new technology, ranging from physical media involving solid adsorbents, to chemical materials including metal hydrides, ammonia borane and liquid precursors such as alcohols and formic acid.

  3. Waste/By-Product Hydrogen

    Science.gov (United States)

    2011-01-13

    By‐ product Hydrogen Fuel Flexibility Biogas : generated from organic waste �Wastewater treatment plants can provide multiple MW of renewable... Waste /By product Hydrogen Waste H2 sources include: � Waste bio‐mass: biogas to high temp fuel cells to produce H2 – there are over two dozen sites...13 Waste /By product Hydrogen ‐ Biogas

  4. Direct determination of phosphate esters in concentrated nitrate media by capillary zone electrophoresis.

    Science.gov (United States)

    Rivasseau, C; Lando, L; Rey-Gaurez, F; Bisel, I; Sans, D; Faucon, M; Adnet, J M

    2003-10-10

    The potential of capillary zone electrophoresis (CZE) for the determination of dibutyl phosphate (DBP) and monobutyl phosphate (MBP), two degradation products of the tributyl phosphate extractant used in the nuclear fuel reprocessing industry, was evaluated. Analysis conditions were optimised, taking particularly into account that many determinations had to be performed in concentrated aqueous nitrate or nitric acid solutions. Separations were therefore carried out using the counter-electroosmotic mode with cathodic detection in a pH 8.3 electrolyte containing a suitably selected chromophore, salicylate, to ensure the indirect UV detection of the analytes. Various aspects of the method, including its sensitivity, working range, repeatability, and rapidity, were examined. Quantification of both phosphate esters was achieved in less than 3 min at concentrations ranging from 2 x 10(-6) to 10(-3) mol l(-1) in samples containing no macro-component. The lower end of this range increased to 5 x 10(-6) mol l(-1) for MBP and 1.5 x 10(-5) mol l(-1) for DBP in samples containing 5 x 10(-2) mol l(-1) of sodium nitrate, thus enabling their determination in solutions containing nitrate or nitric acid at concentrations up to, respectively, 10,000 and 3000 times higher than the target analyte concentration. This simple, fast and reliable method is routinely applicable to aqueous samples with no other preliminary treatment than a proper dilution; analysis was also performed in organic matrices after a prior extraction. The method was validated by an excellent correlation with the standard DBP analysis technique, gas chromatography (GC). In order to develop appropriate chemical treatments to destroy these compounds, the method was applied to the monitoring of DBP and MBP degradation by hydrogen peroxide in 1 mol l(-1) nitric acid solutions.

  5. Pulsed electrodeposition for the synthesis of strontium-substituted calcium phosphate coatings with improved dissolution properties

    Energy Technology Data Exchange (ETDEWEB)

    Drevet, Richard, E-mail: richard.drevet@univ-reims.fr; Benhayoune, Hicham

    2013-10-15

    Strontium-substituted calcium phosphate coatings are synthesized by pulsed electrodeposition on titanium alloy (Ti6Al4V) substrates. Experimental conditions of the process are optimized in order to obtain a coating with a 5% atomic substitution of calcium by strontium which corresponds to the best observations on the osteoblast cells activity and on the osteoclast cells proliferation. The physical and chemical characterizations of the obtained coating are carried out by scanning electron microscopy associated to energy dispersive X-ray spectroscopy (EDXS) for X-ray microanalysis and the structural characterization of the coating is carried out by X-ray diffraction. The in vitro dissolution/precipitation properties of the coated substrates are investigated by immersion into Dulbecco's Modified Eagle Medium (DMEM) from 1 h to 14 days. The calcium, phosphorus and strontium concentrations variations in the biological liquid are assessed by Induced Coupled Plasma - Atomic Emission Spectroscopy for each immersion time. The results show that under specific experimental conditions, the electrodeposition process is suitable to synthesize strontium-substituted calcium phosphate coatings. Moreover, the addition of hydrogen peroxide (H{sub 2}O{sub 2}) into the electrolytic solution used in the process allows us to observe a control of the strontium release during the immersion of the prosthetic materials into DMEM. - Highlights: • Strontium-substituted calcium phosphate coatings are successfully electrodeposited. • The strontium is homogeneously distributed in the synthesized prosthetic coating. • This divalent cation modifies the calcium phosphate structure. • H{sub 2}O{sub 2} addition in the electrolyte allows to control the coating's stoichiometry. • This implies a control of the strontium release in the physiological environment.

  6. Inositol phosphates induce DAPI fluorescence shift.

    Science.gov (United States)

    Kolozsvari, Bernadett; Parisi, Federica; Saiardi, Adolfo

    2014-06-15

    The polymer inorganic polyP (polyphosphate) and inositol phosphates, such as IP6 (inositol hexakisphosphate; also known as phytic acid), share many biophysical features. These similarities must be attributed to the phosphate groups present in these molecules. Given the ability of polyP to modify the excitation-emission spectra of DAPI we decided to investigate whether inositol phosphates possess the same property. We discovered that DAPI-IP6 complexes emit at approximately 550 nm when excited with light of wavelength 410-420 nm. IP5 (inositol pentakisphosphate) is also able to induce a similar shift in DAPI fluorescence. Conversely, IP3 (inositol trisphosphate) and IP4 (inositol tetrakisphosphate) are unable to shift DAPI fluorescence. We have employed this newly discovered feature of DAPI to study the enzymatic activity of the inositol polyphosphate multikinase and to monitor phytase phosphatase reactions. Finally, we used DAPI-IP6 fluorescence to determine the amount of IP6 in plant seeds. Using an IP6 standard curve this straight-forward analysis revealed that among the samples tested, borlotti beans possess the highest level of IP6 (9.4 mg/g of dry mass), whereas the Indian urad bean the lowest (3.2 mg/g of dry mass). The newly identified fluorescence properties of the DAPI-IP5 and DAPI-IP6 complexes allow the levels and enzymatic conversion of these two important messengers to be rapidly and reliably monitored.

  7. Frozen delivery of brushite calcium phosphate cements.

    Science.gov (United States)

    Grover, Liam M; Hofmann, Michael P; Gbureck, Uwe; Kumarasami, Balamurgan; Barralet, Jake E

    2008-11-01

    Calcium phosphate cements typically harden following the combination of a calcium phosphate powder component with an aqueous solution to form a matrix consisting of hydroxyapatite or brushite. The mixing process can be very important to the mechanical properties exhibited by cement materials and consequently when used clinically, since they are usually hand-mixed their mechanical properties are prone to operator-induced variability. It is possible to reduce this variability by pre-mixing the cement, e.g. by replacing the aqueous liquid component with non-reactive glycerol. Here, for the first time, we report the formation of three different pre-mixed brushite cement formulations formed by freezing the cement pastes following combination of the powder and liquid components. When frozen and stored at -80 degrees C or less, significant degradation in compression strength did not occur for the duration of the study (28 days). Interestingly, in the case of the brushite cement formed from the combination of beta-tricalcium phosphate with 2 M orthophosphoric acid solution, freezing the cement paste had the effect of increasing mean compressive strength fivefold (from 4 to 20 MPa). The increase in compression strength was accompanied by a reduction in the setting rate of the cement. As no differences in porosity or degree of reaction were observed, strength improvement was attributed to a modification of crystal morphology and a reduction in damage caused to the cement matrix during manipulation.

  8. Phosphate phosphors for solid-state lighting

    Energy Technology Data Exchange (ETDEWEB)

    Shinde, Kartik N. [N.S. Science and Arts College, Bhadrawati (India). Dept. of Physics; Swart, H.C. [University of the Orange Free State, Bloemfontein (South Africa). Dept. of Physics; Dhoble, S.J. [R.T.M. Nagpur Univ. (India). Dept. of Physics; Park, Kyeongsoon [Sejong Univ., Seoul (Korea, Republic of). Faculty of Nanotechnology and Advanced Materials Engineering

    2012-07-01

    Essential information for students in researchers working towards new and more efficient solid-state lighting. Comprehensive survey based on the authors' long experience. Useful both for teaching and reference. The idea for this book arose out of the realization that, although excellent surveys and a phosphor handbook are available, there is no single source covering the area of phosphate based phosphors especially for lamp industry. Moreover, as this field gets only limited attention in most general books on luminescence, there is a clear need for a book in which attention is specifically directed toward this rapidly growing field of solid state lighting and its many applications. This book is aimed at providing a sound introduction to the synthesis and optical characterization of phosphate phosphor for undergraduate and graduate students as well as teachers and researchers. The book provides guidance through the multidisciplinary field of solid state lighting specially phosphate phosphors for beginners, scientists and engineers from universities, research organizations, and especially industry. In order to make it useful for a wide audience, both fundamentals and applications are discussed, together.

  9. Phosphate valorization by dry chlorination route

    Directory of Open Access Journals (Sweden)

    Kanari N.

    2016-01-01

    Full Text Available This work deals with the extraction of phosphorus chlorinated compounds from phosphate materials using chlorination with gaseous chlorine. An industrial sample of dicalcium phosphate dihydrate, after transformation into calcium pyrophosphate (Ca2P2O7, is subjected to reactions with Cl2+CO+N2 and Cl2+C+N2 at temperatures ranging from 625 to 950°C using boat experiments. Gathering results of the thermodynamic predictions and TG/DT analysis with those of SEM and XRD examinations of the chlorinated residues allowed the interpretation of phenomena and reactions mechanism occurring during the calcium pyrophosphate carbochlorination. Reaction rate of Ca2P2O7 by Cl2+CO+N2 at 950°C is slowed down due to the formation of a CaCl2 liquid layer acting as a barrier for the diffusion of the reactive gases and further reaction progress. While, the carbochlorination with Cl2+C+N2 led to almost full chlorination of Ca2P2O7 at 750°C and the process proceeds with an apparent activation energy of about 104 kJ/mol between 625 and 750°C. Carbochlorination technique can be considered as an alternative and selective route for the valorization of low grade phosphates and for the phosphorus extraction from its bearing materials.

  10. Hydrothermal method for preparing calcium phosphate monoliths

    Directory of Open Access Journals (Sweden)

    García Carrodeguas Raúl

    2003-01-01

    Full Text Available A new hydrothermal route for preparing biphasic calcium phosphate monoliths is proposed. Firstly, a slurry of beta-tricalcium phosphate/ortho-phosphoric acid (b-TCP/H3PO4 is cast into the desired final shape and size to obtain a block composed of dicalcium phosphate dihydrate (DCPD and b-TCP. This block is then treated in 1.0 M Na2HPO4 at 60 °C in order to hydrolyze the DCPD into Ca10-x(HPO4x(PO4 6-x(OH2-x (CDHA and Ca8H2(PO46 .5H2O (OCP. The result is a monolithic piece which preserves the initial shape and size, but which is composed instead of CDHA, OCP, and b-TCP. During the initial stage, when the pH is slightly alkaline, the product of DCPD hydrolysis is CDHA. However, when a neutral or slightly acidic pH is reached OCP is formed. Test samples processed by this method showed complete conversion of DCPD into CDHA and OCP after 112 h of hydrolysis, and with a compressive strength of 16.2 MPa, similar to cancellous bone.

  11. Phosphate adsorption on lanthanum loaded biochar.

    Science.gov (United States)

    Wang, Zhanghong; Shen, Dekui; Shen, Fei; Li, Tianyu

    2016-05-01

    To attain a low-cost and high-efficient phosphate adsorbent, lanthanum (La) loaded biochar (La-BC) prepared by a chemical precipitation method was developed. La-BC and its pristine biochar (CK-BC) were comparatively characterized using zeta potential, BET surface area, scanning electron microscopy/energy dispersive spectrometer (SEM-EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FT-IR). The adsorption ability and the mechanisms during adsorption process for the La-BC samples were also investigated. La loaded on the surface of biochar can be termed as La-composites (such as LaOOH, LaONO3 and La(OH)3), leading to the decrease of negative charge and surface area of biochar. La-BC exhibited the high adsorption capacity to phosphate compared to CK-BC. Adsorption isotherm and adsorption kinetic studies showed that the Langmuir isotherm and second order model could well describe the adsorption process of La-BC, indicating that the adsorption was dominated by a homogeneous and chemical process. The calculated maximum adsorption capacity was as high as 46.37 mg g(-1) (computed in P). Thermodynamic analysis revealed that the adsorption was spontaneous and endothermic. SEM, XRD, XPS and FT-IR analysis suggested that the multi-adsorption mechanisms including precipitation, ligand exchange and complexation interactions can be evidenced during the phosphate adsorption process by La-composites in La-BC.

  12. Phosphate removal from wastewater using red mud.

    Science.gov (United States)

    Huang, Weiwei; Wang, Shaobin; Zhu, Zhonghua; Li, Li; Yao, Xiangdong; Rudolph, Victor; Haghseresht, Fouad

    2008-10-01

    Red mud, a waste residue of alumina refinery, has been used to develop effective adsorbents to remove phosphate from aqueous solution. Acid and acid-thermal treatments were employed to treat the raw red mud. The effects of different treatment methods, pH of solution and operating temperature on adsorption have been examined in batch experiments. It was found that all activated red mud samples show higher surface area and total pore volume as well as higher adsorption capacity for phosphate removal. The red mud with HCl treatment shows the highest adsorption capacity among all the red mud samples, giving adsorption capacity of 0.58 mg P/g at pH 5.5 and 40 degrees C. The adsorption capacity of the red mud adsorbents decreases with increase of pH. At pH 2, the red mud with HCl treatment exhibits adsorption of 0.8 mg P/g while the adsorption can be lowered to 0.05 mg P/g at pH 10. However, the adsorption is improved at higher temperature by increasing 25% from 30 to 40 degrees C. The kinetic studies of phosphate adsorption onto red mud indicate that the adsorption mainly follows the parallel first-order kinetics due to the presence of two acidic phosphorus species, H(2)PO(4)(-) and HPO(4)(2-). An analysis of the adsorption data indicates that the Freundlich isotherm provides a better fitting than the Langmuir model.

  13. Method for phosphate-accelerated bioremediation

    Science.gov (United States)

    Looney, Brian B.; Lombard, Kenneth H.; Hazen, Terry C.; Pfiffner, Susan M.; Phelps, Tommy J.; Borthen, James W.

    1996-01-01

    An apparatus and method for supplying a vapor-phase nutrient to contaminated soil for in situ bioremediation. The apparatus includes a housing adapted for containing a quantity of the liquid nutrient, a conduit in fluid communication with the interior of the housing, means for causing a gas to flow through the conduit, and means for contacting the gas with the liquid so that a portion thereof evaporates and mixes with the gas. The mixture of gas and nutrient vapor is delivered to the contaminated site via a system of injection and extraction wells configured to the site. The mixture has a partial pressure of vaporized nutrient that is no greater than the vapor pressure of the liquid. If desired, the nutrient and/or the gas may be heated to increase the vapor pressure and the nutrient concentration of the mixture. Preferably, the nutrient is a volatile, substantially nontoxic and nonflammable organic phosphate that is a liquid at environmental temperatures, such as triethyl phosphate or tributyl phosphate.

  14. Hydrogen attack - Influence of hydrogen sulfide. [on carbon steel

    Science.gov (United States)

    Eliezer, D.; Nelson, H. G.

    1978-01-01

    An experimental study is conducted on 12.5-mm-thick SAE 1020 steel (plain carbon steel) plate to assess hydrogen attack at room temperature after specimen exposure at 525 C to hydrogen and a blend of hydrogen sulfide and hydrogen at a pressure of 3.5 MN/sq m for exposure times up to 240 hr. The results are discussed in terms of tensile properties, fissure formation, and surface scales. It is shown that hydrogen attack from a high-purity hydrogen environment is severe, with the formation of numerous methane fissures and bubbles along with a significant reduction in the room-temperature tensile yield and ultimate strengths. However, no hydrogen attack is observed in the hydrogen/hydrogen sulfide blend environment, i.e. no fissure or bubble formation occurred and the room-temperature tensile properties remained unchanged. It is suggested that the observed porous discontinuous scale of FeS acts as a barrier to hydrogen entry, thus reducing its effective equilibrium solubility in the iron lattice. Therefore, hydrogen attack should not occur in pressure-vessel steels used in many coal gasification processes.

  15. Electrochemical Hydrogen Peroxide Generator

    Science.gov (United States)

    Tennakoon, Charles L. K.; Singh, Waheguru; Anderson, Kelvin C.

    2010-01-01

    Two-electron reduction of oxygen to produce hydrogen peroxide is a much researched topic. Most of the work has been done in the production of hydrogen peroxide in basic media, in order to address the needs of the pulp and paper industry. However, peroxides under alkaline conditions show poor stabilities and are not useful in disinfection applications. There is a need to design electrocatalysts that are stable and provide good current and energy efficiencies to produce hydrogen peroxide under acidic conditions. The innovation focuses on the in situ generation of hydrogen peroxide using an electrochemical cell having a gas diffusion electrode as the cathode (electrode connected to the negative pole of the power supply) and a platinized titanium anode. The cathode and anode compartments are separated by a readily available cation-exchange membrane (Nafion 117). The anode compartment is fed with deionized water. Generation of oxygen is the anode reaction. Protons from the anode compartment are transferred across the cation-exchange membrane to the cathode compartment by electrostatic attraction towards the negatively charged electrode. The cathode compartment is fed with oxygen. Here, hydrogen peroxide is generated by the reduction of oxygen. Water may also be generated in the cathode. A small amount of water is also transported across the membrane along with hydrated protons transported across the membrane. Generally, each proton is hydrated with 3-5 molecules. The process is unique because hydrogen peroxide is formed as a high-purity aqueous solution. Since there are no hazardous chemicals or liquids used in the process, the disinfection product can be applied directly to water, before entering a water filtration unit to disinfect the incoming water and to prevent the build up of heterotrophic bacteria, for example, in carbon based filters. The competitive advantages of this process are: 1. No consumable chemicals are needed in the process. The only raw materials

  16. Fabrications of zinc-releasing biocement combining zinc calcium phosphate to calcium phosphate cement.

    Science.gov (United States)

    Horiuchi, Shinya; Hiasa, Masahiro; Yasue, Akihiro; Sekine, Kazumitsu; Hamada, Kenichi; Asaoka, Kenzo; Tanaka, Eiji

    2014-01-01

    Recently, zinc-releasing bioceramics have been the focus of much attention owing to their bone-forming ability. Thus, some types of zinc-containing calcium phosphate (e.g., zinc-doped tricalcium phosphate and zinc-substituted hydroxyapatite) are examined and their osteoblastic cell responses determined. In this investigation, we studied the effects of zinc calcium phosphate (ZCP) derived from zinc phosphate incorporated into calcium phosphate cement (CPC) in terms of its setting reaction and MC3T3-E1 osteoblast-like cell responses. Compositional analysis by powder X-ray diffraction analysis revealed that HAP crystals were precipitated in the CPC containing 10 or 30wt% ZCP after successfully hardening. However, the crystal growth observed by scanning electron microscopy was delayed in the presence of additional ZCP. These findings indicate that the additional zinc inhibits crystal growth and the conversion of CPC to the HAP crystals. The proliferation of the cells and alkaline phosphatase (ALP) activity were enhanced when 10wt% ZCP was added to CPC. Taken together, ZCP added CPC at an appropriate fraction has a potent promotional effect on bone substitute biomaterials.

  17. Radiological impact of natural radioactivity in Egyptian phosphate rocks, phosphogypsum and phosphate fertilizers.

    Science.gov (United States)

    El-Bahi, S M; Sroor, A; Mohamed, Gehan Y; El-Gendy, N S

    2017-05-01

    In this study, the activity concentrations of the natural radionuclides in phosphate rocks and its products were measured using a high- purity germanium detector (HPGe). The obtained activity results show remarkable wide variation in the radioactive contents for the different phosphate samples. The average activity concentration of (235)U, (238)U, (226)Ra, (232)Th and (40)K was found as (45, 1031, 786, 85 and 765Bq/kg) for phosphate rocks, (28, 1234, 457, 123 and 819Bq/kg) for phosphate fertilizers, (47, 663, 550, 79 and 870Bq/kg) for phosphogypsum and (25, 543, 409, 54 and 897Bq/kg) for single super phosphate respectively. Based on the measured activities, the radiological parameters (activity concentration index, absorbed gamma dose rate in outdoor and indoor and the corresponding annual effective dose rates and total excess lifetime cancer risk) were estimated to assess the radiological hazards. The total excess lifetime cancer risk (ELCR) has been calculated and found to be high in all samples, which related to high radioactivity, representing radiological risk for the health of the population.

  18. Hydrogen diffusion in Zircon

    Science.gov (United States)

    Ingrin, Jannick; Zhang, Peipei

    2016-04-01

    Hydrogen mobility in gem quality zircon single crystals from Madagascar was investigated through H-D exchange experiments. Thin slices were annealed in a horizontal furnace flushed with a gas mixture of Ar/D2(10%) under ambient pressure between 900 ° C to 1150 ° C. FTIR analyses were performed on oriented slices before and after each annealing run. H diffusion along [100] and [010] follow the same diffusion law D = D0exp[-E /RT], with log D0 = 2.24 ± 1.57 (in m2/s) and E = 374 ± 39 kJ/mol. H diffusion along [001] follows a slightly more rapid diffusion law, with log D0 = 1.11 ± 0.22 (in m2/s) and E = 334 ± 49 kJ/mol. H diffusion in zircon has much higher activation energy and slower diffusivity than other NAMs below 1150 ° C even iron-poor garnets which are known to be among the slowest (Blanchard and Ingrin, 2004; Kurka et al. 2005). During H-D exchange zircon incorporates also deuterium. This hydration reaction involves uranium reduction as it is shown from the exchange of U5+ and U4+ characteristic bands in the near infrared region during annealing. It is the first time that a hydration reaction U5+ + OH- = U4+ + O2- + 1/2H2, is experimentally reported. The kinetics of deuterium incorporation is slightly slower than hydrogen diffusion, suggesting that the reaction is limited by hydrogen mobility. Hydrogen isotopic memory of zircon is higher than other NAMs. Zircons will be moderately retentive of H signatures at mid-crustal metamorphic temperatures. At 500 ° C, a zircon with a radius of 300 μm would retain its H isotopic signature over more than a million years. However, a zircon is unable to retain this information for geologically significant times under high-grade metamorphism unless the grain size is large enough. Refrences Blanchard, M. and Ingrin, J. (2004) Hydrogen diffusion in Dora Maira pyrope. Physics and Chemistry of Minerals, 31, 593-605. Kurka, A., Blanchard, M. and Ingrin, J. (2005) Kinetics of hydrogen extraction and deuteration in

  19. Development of an Accelerated Hydrogen Embrittlement Test for Manganese Phosphated Steels

    Science.gov (United States)

    2011-05-01

    Testing Systems) and lot (HT/ HTP ) were used. See Appendix B for the certifications for lots HT/ HTP . Note: lot HTP is...long as 432 hrs., and testing after furnace bakeout. The majority of testing was performed on the same lot of material (RSL Lot HT/ HTP ) and coated by...slower ISL tests were performed. Figure 14. ISL  test  specimen RSL  HTP  #089  tested

  20. Preparation of Hydrogenated Nitrile Rubber

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ Hydrogenated nitrile rubber is an oil and solvent resistant rubber and particularly give more resistant to heat, ozone, light. It is generally prepared from nitrile rubber by selective hydrogenation using a suitable catalyst system. In the present work a prepared method was adapted for the hydrogenation reaction of nitrile rubber using homogeneous tris(tri-phenlphosphine)chlorhodium(I) catalyst (RhCl(PPh3)) system. The hydrogenation reaction was carriedout at different temperature, pressure, time and catalyst concentration, the concentration, the conditions of hydrogenation are stated in table 1.

  1. Preparation of Hydrogenated Nitrile Rubber

    Institute of Scientific and Technical Information of China (English)

    LIU; ZhiCai

    2001-01-01

    Hydrogenated nitrile rubber is an oil and solvent resistant rubber and particularly give more resistant to heat, ozone, light. It is generally prepared from nitrile rubber by selective hydrogenation using a suitable catalyst system. In the present work a prepared method was adapted for the hydrogenation reaction of nitrile rubber using homogeneous tris(tri-phenlphosphine)chlorhodium(I) catalyst (RhCl(PPh3)) system.  The hydrogenation reaction was carriedout at different temperature, pressure, time and catalyst concentration, the concentration, the conditions of hydrogenation are stated in table 1.  ……

  2. [1-(Carboxymethylcyclohexyl]methanaminium dihydrogen phosphate

    Directory of Open Access Journals (Sweden)

    Syed Naeem Razzaq

    2010-05-01

    Full Text Available In the title salt, C9H18NO2+·H2PO4−, the cyclohexane ring is puckered, the total puckering amplitude QT being 0.555 (4 Å, and an intramolecular N—H...O hydrogen bond generates an S(7 ring. In the crystal structure, intermolecular N—H...O and O—H...O hydrogen bonds lead to R22(14, R33(8 and R42(8 rings, generating a two-dimensional layer.

  3. Europe - the first hydrogen economy?

    Energy Technology Data Exchange (ETDEWEB)

    Hart, D. [TH Huxley School, Imperial College, London, (United Kingdom)

    1999-12-01

    An examination of the state of research relating to hydrogen production and utilization indicates that interest in hydrogen from major companies in Europe has increased by several orders of magnitude in recent years. Of the three major areas where a hydrogen economy could be expected to start, namely, Japan, the United States and Europe, the latter may have advantages in diversity of resources, attitudes towards environmental issues and specific fiscal and regulatory structures. Examples of ongoing research and development projects in Europe include Norway`s hydrogen combustion turbine to run on hydrogen from decarbonised natural gas, a project in the Netherlands involving mixing hydrogen and methane in the natural gas grid and a variety of projects involving liquid hydrogen refuelling, hydrogen aircraft, hydrogen fuelling stations and fuel cell vehicle development. There are also ongoing projects in carbon sequestration and hydrogen production for power generation and vehicle use. The author`s main contention is that the combination of natural surroundings, environmental problems and attitudes, and business and government frameworks strongly suggest that Europe may be the first to have a hydrogen-based economy. 8 refs.

  4. Europe - the first hydrogen economy?

    Energy Technology Data Exchange (ETDEWEB)

    Hart, D. [TH Huxley School, Imperial College, London, (United Kingdom)

    1999-07-01

    An examination of the state of research relating to hydrogen production and utilization indicates that interest in hydrogen from major companies in Europe has increased by several orders of magnitude in recent years. Of the three major areas where a hydrogen economy could be expected to start, namely, Japan, the United States and Europe, the latter may have advantages in diversity of resources, attitudes towards environmental issues and specific fiscal and regulatory structures. Examples of ongoing research and developmentprojects in Europe include Norway's hydrogen combustion turbine to run on hydrogen from decarbonised natural gas, a project in the Netherlands involving mixing hydrogen and methane in the natural gas grid and a variety of projects involving liquid hydrogen refuelling, hydrogen aircraft, hydrogen fuelling stations and fuel cell vehicle development. There are also ongoing projects in carbon sequestration and hydrogen production for power generation and vehicle use. The author's main contention is that the combination of natural surroundings, environmental problems and attitudes, and business and government frameworks strongly suggest that Europe may be the first to have a hydrogen-based economy. 8 refs.

  5. Proton transport properties of tin phosphate, chromotropic acid anchored onto tin phosphate and tin phenyl phosphonate

    Indian Academy of Sciences (India)

    Chithra Sumej; P P Sharmila; Nisha J Tharayil; S Suma

    2013-02-01

    Tin (IV) phosphates of the class of tetravalent metal acid (TMA) salts have been synthesized by sol–gel method. The functionalized materials of tin (IV) phosphate (SnP) like chromotropic acid anchored tin phosphate (SnPCA) and tin phenyl phosphonate (SnPP) were also synthesized. These materials have been characterized for elemental analysis (ICP–AES), thermal analysis, X-ray analysis and FTIR spectroscopy. Chemical resistivity of these materials has been accessed in acidic, basic and organic solvent media. The proton present in the structural hydroxyl groups indicates good potential for TMA salts to exhibit solid-state proton conduction. The transport properties of these materials have been explored by measuring specific proton conductance at different temperatures. Based on the specific conduction data and Arrhenius plots, a suitable mechanism has been proposed.

  6. Concomitant rock phosphate dissolution and lead immobilization by phosphate solubilizing bacteria (Enterobacter sp.).

    Science.gov (United States)

    Park, Jin Hee; Bolan, Nanthi; Megharaj, Mallavarapu; Naidu, Ravi

    2011-04-01

    This paper examines the potential value of phosphate solubilizing bacteria (Enterobacter cloacae) in the dissolution of rock phosphate (RP) and subsequent immobilization of lead (Pb) in both bacterial growth medium and soils. Enterobacter sp. showed resistance to Pb and the bacterium solubilized 17.5% of RP in the growth medium. Enterobacter sp. did not enhance Pb immobilization in solution because of acidification of bacterial medium, thereby inhibiting the formation of P-induced Pb precipitation. However, in the case of soil, Enterobacter sp. increased Pb immobilization by 6.98, 25.6 and 32.0% with the RP level of 200, 800 and 1600 mg P/kg, respectively. The immobilization of Pb in Pb-spiked soils was attributed to pyromorphite formation as indicated by XRD analysis. Inoculation of phosphate solubilizing bacteria with RP in soil can be used as an alternative technique to soluble P compounds which can cause eutrophication of surface water.

  7. New approaches to hydrogen storage.

    Science.gov (United States)

    Graetz, Jason

    2009-01-01

    The emergence of a Hydrogen Economy will require the development of new media capable of safely storing hydrogen in a compact and light weight package. Metal hydrides and complex hydrides, where hydrogen is chemically bonded to the metal atoms in the bulk, offer some hope of overcoming the challenges associated with hydrogen storage. The objective is to find a material with a high volumetric and gravimetric hydrogen density that can also meet the unique demands of a low temperature automotive fuel cell. Currently, there is considerable effort to develop new materials with tunable thermodynamic and kinetic properties. This tutorial review provides an overview of the different types of metal hydrides and complex hydrides being investigated for on-board (reversible) and off-board (non-reversible) hydrogen storage along with a few new approaches to improving the hydrogenation-dehydrogenation properties.

  8. Hydrogen Exchange Mass Spectrometry.

    Science.gov (United States)

    Mayne, Leland

    2016-01-01

    Hydrogen exchange (HX) methods can reveal much about the structure, energetics, and dynamics of proteins. The addition of mass spectrometry (MS) to an earlier fragmentation-separation HX analysis now extends HX studies to larger proteins at high structural resolution and can provide information not available before. This chapter discusses experimental aspects of HX labeling, especially with respect to the use of MS and the analysis of MS data.

  9. Molecular and Metallic Hydrogen

    Science.gov (United States)

    1977-05-01

    interaction between hydroge , molecules. Fortunately, theoretical calculation of the pair potential from first principles at small intermolecular...three- ,’ody effect is a general phenomenon for all highly condensed states of molecular hydroger The effect of t’ ,ree-body contribution to the...parameters of metallic hydroge -. have given more consis- tent results than those for the molecular hydrogen. For example, the r-sults of the earliest

  10. Effectiveness of a rock phosphate solubilizing fungus to increase soil solution phosphate impaired by the soil phosphate sorption capacity

    Directory of Open Access Journals (Sweden)

    Nelson Walter Osorio Vega

    2015-06-01

    Full Text Available Available phosphate (P deficiency in tropical soils has been recognized as a major factor that limits soil quality and plant performance. To overcome this, it is necessary to add high amounts of soluble P-fertilizers; however, this is inefficient and costly. Alternatively, rock phosphates (RP can be used, but their low reactivity limits their use. Phosphate solubilizing microorganisms (PSM can enhance RP dissolution and, thus, improve the RP agronomic effectiveness as fertilizer. Nonetheless, their effectiveness may be impaired by the soil P fixation capacity. An experiment was carried out to assess the in vitro effectiveness of the fungus Mortierella sp. to dissolve RP in an axenic culture medium and, thus, enhance the solution P concentration in the presence of aliquots of soils with contrasting P fixation capacity. The results showed that the fungus was capable of lowering the medium pH from 7.7 to 3.0 and, thus, dissolving the RP. The presence of soil aliquots in the medium controlled the effectiveness of the fungus to increase the concentration of the soluble P. In the presence of soils with a low or medium P sorption capacity, the concentration of the soluble P was high (63.8-146.6 mg L-1 in comparison with the inoculated (soilless treatment (50.0 mg L-1 and the uninoculated control (0.7 mg L-1. By contrast, with very-high P fixing soil aliquots, the concentration of the soluble P was very low (3.6-33.1 mg L-1; in addition, in these soils, the fungus immobilized more P into its mycelia than in soils with a low or medium P fixation capacity. The capacity of a soil to fix P seems to be a good predictor for the effectiveness of this fungus to increase the soluble P concentration via RP dissolution.

  11. Phosphates sensing: two polyamino-phenolic zinc receptors able to discriminate and signal phosphates in water.

    Science.gov (United States)

    Ambrosi, Gianluca; Formica, Mauro; Fusi, Vieri; Giorgi, Luca; Guerri, Annalisa; Macedi, Eleonora; Micheloni, Mauro; Paoli, Paola; Pontellini, Roberto; Rossi, Patrizia

    2009-07-06

    Two Zn(II)-dinuclear systems were studied as receptors for phosphates; they were obtained by using the two polyamino-phenolic ligands 3,3'-bis[N,N-bis(2-aminoethyl)aminomethyl]-2,2'-dihydroxybiphenyl (L1) and 2,6-bis[N,N-bis(2-aminoethyl)aminomethyl]phenol (L2) in which the difference lies in the spacers between the two dien units, biphenol or phenol in L1 and L2, respectively. The metallo-receptors obtained are able to selectively discriminate phosphate (Pi) from pyrophosphate (PPi) and vice versa in aqueous solution in a wide range of pH (6 phosphate in a bridge disposition, fit in a different way with the different guests. Furthermore, NMR studies supported the model of interaction proposed between guests and receptors, highlighting that they are also able to bind biological phosphates such as G6P and ATP at physiological pH. Fluorescence studies showed that the receptor system based on L1 is able to signal the presence in solution of Pi and PPi at physiological pH; the presence of Pi is detected by a quenching of the emission, that of PPi by an enhancement of it. With the aid of an external colored sensor (PCV), the receptors were then used to produce simple signaling systems for phosphates based on the displacement method; the two chemosensors obtained are able to signal and quantify these anions at physiological pH, preserving the selectivity between phosphate and pyrophosphate and extending it to G6P and ATP.

  12. MSW to hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Pasternak, A.D.; Richardson, J.H.; Rogers, R.S.; Thorsness, C.B.; Wallman, H. [Lawrence Livermore National Lab., CA (United States); Richter, G.N.; Wolfenbarger, J.K. [Texaco Inc., Montebello, CA (United States). Montebello Research Lab.

    1994-04-19

    LLNL and Texaco are cooperatively developing a physical and chemical treatment method for the preparation and conversion of municipal solid waste (MSW) to hydrogen by gasification and purification. The laboratory focus will be on pretreatment of MSW waste in order to prepare a slurry of suitable viscosity and heating value to allow efficient and economical gasification and hydrogen production. Initial pretreatment approaches include (1) hydrothermal processing at saturated conditions around 300 C with or without chemical/pH modification and (2) mild dry pyrolysis with subsequent incorporation into an appropriate slurry. Initial experiments will be performed with newspaper, a major constituent of MSW, prior to actual work with progressively more representative MSW samples. Overall system modeling with special attention to energy efficiency and waste water handling of the pretreatment process will provide overall guidance to critical scale-up parameters. Incorporation of additional feed stock elements (e.g., heavy oil) will be evaluated subject to the heating value, viscosity, and economics of the MSW optimal slurry for hydrogen production. Ultimate scale-up of the optimized process will provide sufficient material for demonstration in the Texaco pilot facility; additional long term objectives include more detailed economic analysis of the process as a function of technical parameters and development of a measure/control system to ensure slagging ash for variable MSW feed stocks. Details of the overall project plan and initial experimental and modeling results are presented.

  13. Hydrogen molecules in semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Joerg [Technische Universitaet Dresden, 01062 Dresden (Germany)], E-mail: joerg.weber@tu-dresden.de; Hiller, Martin; Lavrov, Edward V. [Technische Universitaet Dresden, 01062 Dresden (Germany)

    2007-12-15

    Molecular hydrogen, the simplest of all molecules, allows a direct insight into the fundamental properties of quantum mechanics. In the case of H{sub 2}, the Pauli principle leads to two different species, para-H{sub 2} and ortho-H{sub 2}. A conversion between these species is prohibited. Vibrational mode spectra reflect the fundamental properties and allow an unambiguous identification of the H{sub 2} molecules. Today, we have experimental evidence for the trapping of hydrogen molecules in the semiconductors Si, Ge and GaAs at the interstitial sites, within hydrogen-induced platelets, in voids and at impurities (interstitial oxygen in Si). Interstitial H{sub 2} is a nearly free rotor with a surprisingly simple behavior. We review on interstitial H{sub 2} in semiconductors and report on the unexpected preferential disappearance of the para-H{sub 2} or ortho-D{sub 2} species. The origin of the detected ortho-para conversion will be discussed.

  14. Photoelectrochemical hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Rocheleau, R.E.; Miller, E.; Zhang, Z. [Univ. of Hawaii, Honolulu, HI (United States)

    1995-09-01

    The large-scale production of hydrogen utilizing energy provided by a renewable source to split water is one of the most ambitious long-term goals of the U.S. Department of Energy`s Hydrogen Program. Photoelectrochemical devices-direct photoconversion systems utilizing a photovoltaic-type structure coated with water-splitting catalysts-represent a promising option to meet this goal. Direct solar-to-chemical conversion efficiencies greater than 7% and photoelectrode lifetimes of up to 30 hours in 1 molar KOH have been demonstrated in our laboratory using low-cost, amorphous-silicon-based photoelectrodes. Loss analysis models indicate that the DOE`s goal of 10% solar-to-chemical conversion can be met with amorphous-silicon-based structures optimized for hydrogen production. In this report, we describe recent progress in the development of thin-film catalytic/protective coatings, improvements in photoelectrode efficiency and stability, and designs for higher efficiency and greater stability.

  15. How to assess the efficacy of phosphate binders.

    Science.gov (United States)

    Caravaca, Francisco; Caravaca-Fontán, Fernando; Azevedo, Lilia; Luna, Enrique

    The efficacy of phosphate binders is difficult to be estimated clinically. This study analyzes the changes in serum phosphate and urinary phosphate excretion after the prescription of phosphate binders (PB) in patients with chronic kidney disease stage 4-5 pre-dialysis, and the usefulness of the ratio between total urinary phosphate and protein catabolic rate (Pu/PCR) for estimating the efficacy of PB. This retrospective observational cohort study included adult chronic kidney disease patients. Biochemical parameters were determined baseline and after 45-60 days on a low phosphate diet plus PB ("binder" subgroup=260 patients) or only with dietary advice ("control" subgroup=79 patients). Phosphate load (total urinary excretion) per unit of renal function (Pu/GFR) was the best parameter correlated with serum phosphate levels (R(2)=0.61). Mean±SD level of Pu/PCR was 8.2±2.3mg of urinary phosphate per each g of estimated protein intake. After treatment with PB, serum phosphate levels decreased by 11%, urinary phosphate 22%, protein catabolic rate 7%, and Pu/PCR 15%. In the control subgroup, Pu/PCR increased by 20%. Urinary phosphate and urea nitrogen excretion correlated strongly, both baseline and after PB or dietary advice. The proposed parameter Pu/PCR may reflect the rate of intestinal phosphate absorption, and therefore, its variations after PB prescription may be a useful tool for estimating the pharmacological efficacy of these drugs. Copyright © 2016 Sociedad Española de Nefrología. Published by Elsevier España, S.L.U. All rights reserved.

  16. Improved hydrogen production under microaerophilic conditions by overexpression of polyphosphate kinase in Enterobacter aerogenes.

    Science.gov (United States)

    Lu, Yuan; Zhang, Chong; Lai, Qiheng; Zhao, Hongxin; Xing, Xin-Hui

    2011-02-08

    Effects of different microaerophilic conditions on cell growth, glucose consumption, hydrogen production and cellular metabolism of wild Enterobacter aerogenes strain and polyphosphate kinase (PPK) overexpressing strain were systematically studied in this paper, using NaH(2)PO(4) as the phosphate sources. Under different microaerophilic conditions, PPK-overexpressing strain showed better cell growth, glucose consumption and hydrogen production than the wild strain. In the presence of limited oxygen (2.1%) and by PPK overexpression, the hydrogen production per liter of culture, the hydrogen production per cell and the hydrogen yield per mol of glucose increased by 20.1%, 12.3% and 10.8%, respectively, compared with the wild strain under strict anaerobic conditions. Metabolic analysis showed that the increase of the total hydrogen yield was attributed to the improvement of NADH pathway. The result of more reductive cellular oxidation state balance also further demonstrated that, under proper initial microaerophilic conditions and by PPK overexpression, the cell could adjust the cellular redox states and make more energy flow into hydrogen production pathways.

  17. Deposition of calcium phosphate coatings using condensed phosphates (P2O7(4-) and P3O10(5-)) as phosphate source through induction heating.

    Science.gov (United States)

    Zhou, Huan; Hou, Saisai; Zhang, Mingjie; Yang, Mengmeng; Deng, Linhong; Xiong, Xinbo; Ni, Xinye

    2016-12-01

    In present work condensed phosphates (P2O7(4-) and P3O10(5-)) were used as phosphate source in induction heating to deposit calcium phosphate coatings. The phase, morphology, and composition of different phosphate-related coatings were characterized and compared using XRD, FTIR, and SEM analyses. Results showed that P2O7(4-)formed calcium pyrophosphate hydrate coatings with interconnected cuboid-like particles. The as-deposited calcium tripolyphosphate hydrate coating with P3O10(5-) was mainly composed of flower-like particles assembled by plate-like crystals. The bioactivity and cytocompatibility of the coatings were also studied. Moreover, the feasibility of using hybrid phosphate sources for preparing and depositing coatings onto magnesium alloy was investigated.

  18. Activation of pyrophosphate:fructose-6-phosphate 1-phosphotransferase by fructose 2,6-bisphosphate stimulates conversion of hexose phosphates to triose phosphates but does not influence accumulation of carbohydrates in phosphate-deficient tobacco cells.

    Science.gov (United States)

    Fernie, Alisdair R; Roscher, Albrecht; Ratcliffe, R. George; Kruger, Nicholas J

    2002-02-01

    The aim of this work was to investigate the contribution of fructose 2,6-bisphosphate to the regulation of carbohydrate metabolism under phosphate stress. The study exploited heterotrophic tobacco callus lines expressing a modified mammalian 6-phosphofructo-2-kinase/fructose 2,6-bisphosphatase that increased the fructose 2,6-bisphosphate content of the tissue. The phosphate status of two transgenic and one untransformed cell line was perturbed by incubation with 2-deoxyglucose, a phosphate-sequestering agent, and by growth of callus on phosphate-depleted media. 31P-NMR spectroscopy confirmed that both treatments decreased cellular levels of inorganic phosphate and phosphorylated metabolites. Despite large decreases in the amounts of phosphate esters, UDPglucose and adenylates in response to phosphate deficiency, the fructose 2,6-bisphosphate content of each line was unaffected by 2-deoxyglucose and increased during growth on phosphate-limited media. Short-term treatment of callus with 2-deoxyglucose had only minor effects on the carbohydrate status of each line, whereas long-term phosphate deficiency caused an increase in starch and a decrease in soluble sugar content in both transgenic and control lines. There were no consistent differences between the three callus lines in metabolism of [U-14C]glucose in response to incubation with 2-deoxyglucose. In contrast, there was a decrease in partitioning of label into glycolytic products (particularly organic acids) in untransformed callus during growth on phosphate-depleted medium. This decrease was greatly attenuated in the transgenic lines with increased fructose 2,6-bisphosphate content. This suggests that the conversion of hexose phosphates to triose phosphates is constrained under phosphate-deficient conditions, and that this restriction can be relieved by activation of pyrophosphate:fructose-6-phosphate 1-phosphotransferase. However, since the transgenic and control lines did not differ in the extent to which the

  19. Structural Diversity Within the Mononuclear and Binuclear Active Sites of N-Acetyl-D-Glucosamine-6-Phosphate Deacetylase

    Energy Technology Data Exchange (ETDEWEB)

    Hall,R.; Brown, S.; Fedorov, A.; Fedorov, E.; Xu, C.; Babbitt, P.; Almo, S.; Raushel, F.

    2007-01-01

    NagA catalyzes the hydrolysis of N-acetyl-D-glucosamine-6-phosphate to D-glucosamine-6-phosphate and acetate. X-ray crystal structures of NagA from Escherichia coli were determined to establish the number and ligation scheme for the binding of zinc to the active site and to elucidate the molecular interactions between the protein and substrate. The three-dimensional structures of the apo-NagA, Zn-NagA, and the D273N mutant enzyme in the presence of a tight-binding N-methylhydroxyphosphinyl-D-glucosamine-6-phosphate inhibitor were determined. The structure of the Zn-NagA confirms that this enzyme binds a single divalent cation at the beta-position in the active site via ligation to Glu-131, His-195, and His-216. A water molecule completes the ligation shell, which is also in position to be hydrogen bonded to Asp-273. In the structure of NagA bound to the tight binding inhibitor that mimics the tetrahedral intermediate, the methyl phosphonate moiety has displaced the hydrolytic water molecule and is directly coordinated to the zinc within the active site. The side chain of Asp-273 is positioned to activate the hydrolytic water molecule via general base catalysis and to deliver this proton to the amino group upon cleavage of the amide bond of the substrate. His-143 is positioned to help polarize the carbonyl group of the substrate in conjunction with Lewis acid catalysis by the bound zinc. The inhibitor is bound in the {alpha}-configuration at the anomeric carbon through a hydrogen bonding interaction of the hydroxyl group at C-1 with the side chain of His-251. The phosphate group of the inhibitor attached to the hydroxyl at C-6 is ion paired with Arg-227 from the adjacent subunit. NagA from Thermotoga maritima was shown to require a single divalent cation for full catalytic activity.

  20. GTI's hydrogen programs: hydrogen production, storage, and applications

    Institute of Scientific and Technical Information of China (English)

    范钦柏

    2006-01-01

    The use of hydrogen as an energy carrier could help address our concerns about energy security, global climate change,and air quality. Fuel cells are an important enabling technology for the Hydrogen Future and have the potential to revolutionize theway we power our nation, offering cleaner, more-efficient alternatives to the combustion of gasoline and other fossil fuels.For over 45 years, GTI has been active in hydrogen energy research, development and demonstration. The Institute has extensive experience and on-going work in all aspects of the hydrogen energy economy including production, delivery, infrastructure,use, safety and public policy. This paper discusses the recent GTI programs in hydrogen production, hydrogen storage, and proton exchange membrane fuel cells (PEMFC) and solid oxide fuel cells (SOFC).

  1. Photoinduced hydrogen-bonding dynamics.

    Science.gov (United States)

    Chu, Tian-Shu; Xu, Jinmei

    2016-09-01

    Hydrogen bonding dynamics has received extensive research attention in recent years due to the significant advances in femtolaser spectroscopy experiments and quantum chemistry calculations. Usually, photoexcitation would cause changes in the hydrogen bonding formed through the interaction between hydrogen donor and acceptor molecules on their ground electronic states, and such transient strengthening or weakening of hydrogen bonding could be crucial for the photophysical transformations and the subsequent photochemical reactions that occurred on a time scale from tens of femtosecond to a few nanoseconds. In this article, we review the combined experimental and theoretical studies focusing on the ultrafast electronic and vibrational hydrogen bonding dynamics. Through these studies, new mechanisms and proposals and common rules have been put forward to advance our understanding of the hydrogen bondings dynamics in a variety of important photoinduced phenomena like photosynthesis, dual fluorescence emission, rotational reorientation, excited-state proton transfer and charge transfer processes, chemosensor fluorescence sensing, rearrangements of the hydrogen-bond network including forming and breaking hydrogen bond in water. Graphical Abstract We review the recent advances on exploring the photoinduced hydrogen bonding dynamics in solutions through a joint approach of laser spectroscopy and theoretical calculation. The reviewed studies have put forward a new mechanism, new proposal, and new rule for a variety of photoinduced phenomena such as photosynthesis, dual fluorescence emission, rotational reorientation, excited-state proton transfer and charge transfer, chemosensor fluorescence sensing, and rearrangements of the hydrogen-bond network in water.

  2. Topotactic exchange and intercalation of calcium phosphate

    Science.gov (United States)

    Lima, Cicero B. A.; Airoldi, Claudio

    2004-11-01

    The precursor (NH 4) 2Ca(H 2PO 4) 2ṡH 2O (CaAP) compound was obtained by combining a calcium chloride solution with dibasic ammonium phosphate. After submitting it to a thermal treatment, crystalline calcium phosphate, Ca(H 2PO 4) 2ṡH 2O (CaP) was isolated. X-ray diffraction patterns for this compound indicated good crystallinity, with a peak at 2θ=12.8°, to give an interlamellar distance of 697 pm, which changed to 1550 pm, when the reaction employed phenylphosphonic acid, and to 1514 pm when intercalated with methylamine. Phosphorus and calcium analysis from colorimetric and gravimetric methods gave for CaP 24.2 and 15.8%, respectively, to yield a P:Ca molar ratio equal to two. The phosphorus nuclear magnetic resonance presented a peak centered at -1.23 ppm, in agreement with the existence of phosphate groups in protonated form. CaAP showed a mass loss of 21.2% in the 466 to 541 K interval due to ammonia and water elimination to yield Ca(PO 3) 3, and CaP can be dehydrated at 440 K for 6 h. A topotactical exchange occurred when CaP is intercalated with methylamine or reacted with phenylphosphonic acid to yield the phosphonate compound and the infrared spectrum of the resulting compound clearly showed the presence of PO 4 and PO 3 groups. The topotactic exchange was also demonstrated by X-ray diffractometry in following the stages of decomposition from 527 to 973 K.

  3. Nucleotides and inorganic phosphates as potential antioxidants.

    Science.gov (United States)

    Richter, Yael; Fischer, Bilha

    2006-11-01

    Highly reactive OH radicals, formed in an iron-ion catalyzed Fenton reaction, are implicated in many pathological conditions. The quest for Fenton reaction inhibitors, either radical scavenger or metal-ion chelator antioxidants, spans the previous decades. Purine nucleotides were previously studied as natural modulators of the Fenton reaction; however, the modulatory role of purine nucleotides remained in dispute. Here, we have resolved this long-standing dispute and demonstrated a concentration-dependent biphasic modulation of the Fenton reaction by nucleotides. By electron spin resonance measurements with 0.1 mM Fe(II), we observed an increase of *OH production at low purine nucleotide concentrations (up to 0.15 mM), while at higher nucleotide concentrations, an exponential decay of *OH concentration was observed. We found that the phosphate moiety, not the nucleoside, determines the pro/antioxidant properties of a nucleotide, suggesting a chelation-based modulation. Furthermore, the biphasic modulation mode is probably due to diverse nucleotide-Fe(II) complexes formed in a concentration-dependent manner. At ATP concentrations much greater than Fe(II) concentrations, multiligand chelates are formed which inhibit the Fenton reaction owing to a full Fe(II) coordination sphere. In addition to natural nucleotides, we investigated a series of base- or phosphate-modified nucleotides, dinucleotides, and inorganic phosphates, as potential biocompatible antioxidants. Ap5A, inorganic thiophosphate and ATP-gamma-S proved highly potent antioxidants with IC50 values of 40, 30, and 10 microM, respectively. ATP-gamma-S proved 100 and 20 times more active than ATP and the potent antioxidant Trolox, respectively. In the presence of 30 microM ATP-gamma-S no *OH was detected after 5 min in the Fenton reaction mixture. The most potent antioxidants identified inhibit the Fenton reaction by forming full coordination sphere chelates.

  4. Phosphate solubilizing bacteria and their role in plant growth promotion.

    Science.gov (United States)

    Rodríguez, H; Fraga, R

    1999-10-01

    The use of phosphate solubilizing bacteria as inoculants simultaneously increases P uptake by the plant and crop yield. Strains from the genera Pseudomonas, Bacillus and Rhizobium are among the most powerful phosphate solubilizers. The principal mechanism for mineral phosphate solubilization is the production of organic acids, and acid phosphatases play a major role in the mineralization of organic phosphorous in soil. Several phosphatase-encoding genes have been cloned and characterized and a few genes involved in mineral phosphate solubilization have been isolated. Therefore, genetic manipulation of phosphate-solubilizing bacteria to improve their ability to improve plant growth may include cloning genes involved in both mineral and organic phosphate solubilization, followed by their expression in selected rhizobacterial strains. Chromosomal insertion of these genes under appropriate promoters is an interesting approach.

  5. Factors determining rock phosphate solubilization by microorganisms isolated from soil.

    Science.gov (United States)

    Nahas, E

    1996-11-01

    Forty two soil isolates (31 bacteria and 11 fungi) were studied for their ability to solubilize rock phosphate and calcium phosphate in culture medium. Eight bacteria and 8 fungi possessed solubilizing ability. Pseudomonas cepacia and Penicillium purpurogenum showed the highest activity. There was a correlation between final pH value and titratable acidity (r=-0.29 to -0.87) and between titratable acidity and soluble phosphate (r=0.22 to 0.99). Correlation values were functions of insoluble phosphate and of the group of microorganisms considered. A high correlation was observed between final pH and soluble phosphate only for the rock phosphates inoculated with the highest concentration of solubilizing bacteria (r=-0.73 to -0.98).

  6. Preparation of Porous Calcium Phosphate Bioceramic

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Porous calcium phosphate ceramics were prepared by slip casting and molding method respectively. By these two different methods, different microstructures can be got. By slip casting method, the pore size was 100- 350μm and 20- 80μm; pores were opened, interconnected and ball-like; the grain size was 2- 4 μm.By molding method, the pore size was 100-500 μm and 1-10μm; the grain size was 2-8μm. By slip casting method regular and interconnected pores can be got. By molding method the porosity and strength can be adjusted easily.

  7. Root architecture remodeling induced by phosphate starvation.

    Science.gov (United States)

    Sato, Aiko; Miura, Kenji

    2011-08-01

    Plants have evolved efficient strategies for utilizing nutrients in the soil in order to survive, grow, and reproduce. Inorganic phosphate (Pi) is a major macroelement source for plant growth; however, the availability and distribution of Pi are varying widely across locations. Thus, plants in many areas experience Pi deficiency. To maintain cellular Pi homeostasis, plants have developed a series of adaptive responses to facilitate external Pi acquisition, limit Pi consumption, and adjust Pi recycling internally under Pi starvation conditions. This review focuses on the molecular regulators that modulate Pi starvation-induced root architectural changes.

  8. The pentose phosphate pathway and cancer.

    Science.gov (United States)

    Patra, Krushna C; Hay, Nissim

    2014-08-01

    The pentose phosphate pathway (PPP), which branches from glycolysis at the first committed step of glucose metabolism, is required for the synthesis of ribonucleotides and is a major source of NADPH. NADPH is required for and consumed during fatty acid synthesis and the scavenging of reactive oxygen species (ROS). Therefore, the PPP plays a pivotal role in helping glycolytic cancer cells to meet their anabolic demands and combat oxidative stress. Recently, several neoplastic lesions were shown to have evolved to facilitate the flux of glucose into the PPP. This review summarizes the fundamental functions of the PPP, its regulation in cancer cells, and its importance in cancer cell metabolism and survival.

  9. Biogenesis of the mitochondrial phosphate carrier

    OpenAIRE

    Zara, Vincenzo; Rassow, Joachim; Wachter, Elmar; Tropschug, Maximilian; Palmieri, Ferdinando; Neupert, Walter; Pfanner, Nikolaus

    1991-01-01

    The mitochondrial phosphate carrier (PiC) is a member of the family of inner-membrane carrier proteins which are generally synthesized without a cleavable presequence. Surprisingly, the cDNA sequences of bovine and rat PiC suggested the existence of an amino-terminal extension sequence in the precursor of PiC. By expressing PiC in vitro, we found that PiC is indeed synthesized as a larger precursor. This precursor was imported and proteolytically processed by mitochondria, whereby the correct...

  10. Handheld hydrogen - a new concept for hydrogen storage

    DEFF Research Database (Denmark)

    Johannessen, Tue; Sørensen, Rasmus Zink

    2005-01-01

    A method of hydrogen storage using metal ammine complexes in combination with an ammonia decomposition catalyst is presented. This dense hydrogen storage material has high degree of safety compared to all the other available alternatives. This technology reduces the safety hazards of using liquid...... ammonia and benefits from the properties of ammonia as a fuel. The system can be used as a safe, reversible, low-cost hydrogen carrier....

  11. Hydrogen solubility in rare earth based hydrogen storage alloys

    Energy Technology Data Exchange (ETDEWEB)

    Uchida, Hirohisa [Tokai Univ., Kanagawa (Japan). School of Engineering; Kuji, Toshiro [Mitsui Mining and Smelting Co. Ltd., Saitama (Japan)

    1999-09-01

    This paper reviews significant results of recent studies on the hydrogen storage properties of rare earth based AB{sub 5} (A: rare earth element, B: transition element) alloys The hydrogen solubility and the hydride formation, typically appeared in pressure-composition isotherms (PCT), are strongly dependent upon alloy composition, structure, morphology and even alloy particle size. Typical experimental results are shown to describe how these factors affect the hydrogen solubility and storage properties.

  12. Handheld hydrogen - a new concept for hydrogen storage

    DEFF Research Database (Denmark)

    Johannessen, Tue; Sørensen, Rasmus Zink

    2005-01-01

    A method of hydrogen storage using metal ammine complexes in combination with an ammonia decomposition catalyst is presented. This dense hydrogen storage material has high degree of safety compared to all the other available alternatives. This technology reduces the safety hazards of using liquid...... ammonia and benefits from the properties of ammonia as a fuel. The system can be used as a safe, reversible, low-cost hydrogen carrier....

  13. Hydrogen-bonded sheets in benzylmethylammonium hydrogen maleate.

    Science.gov (United States)

    Santacruz, Lynay; Abonia, Rodrigo; Cobo, Justo; Low, John N; Glidewell, Christopher

    2007-10-01

    In the title compound, C(8)H(12)N(+).C(4)H(3)O(4)(-), there is a short and almost linear but asymmetric O-H...O hydrogen bond in the anion. The ions are linked into C(2)(2)(6) chains by two short and nearly linear N-H...O hydrogen bonds and the chains are further weakly linked into sheets by a single C-H...O hydrogen bond.

  14. Preparation and Characterization of Porous Calcium Phosphate Bioceramics

    Institute of Scientific and Technical Information of China (English)

    Honglian Dai; Xinyu Wang; Yinchao Han; Xin Jiang; Shipu Li

    2011-01-01

    β-tricalcium phosphate (β-TCP) powder and Na2O-CaO-MgO-P2O5 glass binder were synthesized and mixed, and then the biodegradable porous calcium phosphate ceramics were successfully prepared by foaming and sintering at 850℃. The as-prepared ceramics possess a high porosity with partial three-dimension interconnected macro- and micro-pores. As in vitro experiment testified, the calcium phosphate ceramics (CPCs) has good degradability.

  15. Preparation and characterization of bioceramics produced from calcium phosphate cements

    Energy Technology Data Exchange (ETDEWEB)

    Andriotis, O.; Katsamenis, O.L. [Department of Materials Science, University of Patras, 26504, Patras (Greece); Mouzakis, D.E. [Technological Educational Institute of Larisa, Department of Mechanical Engineering, T.E.I of Larissa, 411 10, Larissa (Greece); Bouropoulos, N. [Foundation for Research and Technology, Hellas, Institute of Chemical Engineering and High Temperature Chemical Processes, FORTH/ICE-HT, P.O. Box 1414, 26504 Rio Patras (Greece)

    2010-03-15

    The present work reports a method for preparing calcium phosphate ceramics by calcination of calcium phosphate cements composed mainly of calcium deficient hydroxyapatite (CDHA). It was found that hardened cements calcinied at temperatures from to 600 to 1300 C were transformed to tricalcium phosphates. Moreover the compressive strength was determined and porosity was estimated as a function of the calcination temperature. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  16. PROCESS FOR THE RECOVERY OF URANIUM FROM PHOSPHATIC ORE

    Science.gov (United States)

    Long, R.L.

    1959-04-14

    A proccss is described for the recovery of uranium from phosphatic products derived from phosphatic ores. It has been discovered that certain alkyl phosphatic, derivatives can be employed in a direct solvent extraction operation to recover uranium from solid products, such as superphosphates, without first dissolving such solids. The organic extractants found suitable include alkyl derivatives of phosphoric, pyrophosphoric, phosof the derivative contains from 4 to 7 carbon atoms. A diluent such as kerosene is also used.

  17. Sorbents for phosphate removal from agricultural drainage water

    DEFF Research Database (Denmark)

    Lyngsie, Gry

    -through cells. Further, in order to improve our understanding of phosphate sorption reactions and kinetics for different types of commercial available PSMs, three different types were studied by means of isothermal titration calorimetry, sorption isotherms, sequential extractions and SEM-EDS. In conclusion......, of the materials investigated the results from phosphate sorption and desorption studies clearly demonstrate that regarding phosphate sorption affinity, capacity and reactivity, iron oxide based PSM is superior as a filter material compared to the other tested materials....

  18. Enriching vermicompost by nitrogen fixing and phosphate solubilizing bacteria.

    Science.gov (United States)

    Kumar, V; Singh, K P

    2001-01-01

    The effect of inoculation of vermicompost with nitrogen-fixing Azotobacter chroococcum strains, Azospirillum lipoferum and the phosphate solubilizing Pseudomonas striata on N and P contents of the vermicompost was assessed. Inoculation of N2 fixing bacteria into vermicompost increased contents of N and P. Enriching vermicompost with rock phosphate improved significantly the available P when inoculated with P. striata. During the incubation period, the inoculated bacterial strains proliferated rapidly, fixed N and solubilized added and native phosphate.

  19. Calcium phosphate precipitation modeling in a pellet reactor

    OpenAIRE

    Montastruc, Ludovic; Azzaro-Pantel, Catherine; Cabassud, Michel; Biscans, Béatrice

    2002-01-01

    The calcium phosphate precipitation in a pellet reactor can be evaluated by two main parameters: the phosphate conversion ratio and the phosphate removal efficiency. The conversion ratio depends mainly on the pH. The pellet reactor efficiency depends not only on pH but also on the hydrodynamical conditions. An efficiency model based on a thermochemical precipitation approach and an orthokinetic aggregation model is presented. In this paper, the results show that optimal conditions for pellet ...

  20. Solar hydrogen production: renewable hydrogen production by dry fuel reforming

    Science.gov (United States)

    Bakos, Jamie; Miyamoto, Henry K.

    2006-09-01

    SHEC LABS - Solar Hydrogen Energy Corporation constructed a pilot-plant to demonstrate a Dry Fuel Reforming (DFR) system that is heated primarily by sunlight focusing-mirrors. The pilot-plant consists of: 1) a solar mirror array and solar concentrator and shutter system; and 2) two thermo-catalytic reactors to convert Methane, Carbon Dioxide, and Water into Hydrogen. Results from the pilot study show that solar Hydrogen generation is feasible and cost-competitive with traditional Hydrogen production. More than 95% of Hydrogen commercially produced today is by the Steam Methane Reformation (SMR) of natural gas, a process that liberates Carbon Dioxide to the atmosphere. The SMR process provides a net energy loss of 30 to 35% when converting from Methane to Hydrogen. Solar Hydrogen production provides a 14% net energy gain when converting Methane into Hydrogen since the energy used to drive the process is from the sun. The environmental benefits of generating Hydrogen using renewable energy include significant greenhouse gas and criteria air contaminant reductions.