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Sample records for 2-aminoethoxydiphenyl borate 2-apb

  1. 2-aminoethoxydiphenyl borate or lanthanum potentiates transient receptor potential-like channels in rat CA1 hippocampal neurons

    Institute of Scientific and Technical Information of China (English)

    Fengpeng Sun; Tian-ming Gao

    2010-01-01

    Expression of transient receptor potential(TRP)channels is widespread with transcripts distributed throughout the brain.All TRP channel subunits are activated following phospholipase C activation and form cation-selective ion channels.Previous studies examining the existence of TRP channels in hippocampal CA1 pyramidal neurons were based on cultured neurons.Therefore,their relevance for living tissue remains unclear.In the present study,patch-clamp recordings were conducted from CA1 pyramidal neurons in hippocampal slices from 7-day-old rats.Whole-cell currents were obtained from CA1 hippocampal neurons with potentiation effects of 2-aminoethoxydiphenyl borate and lanthanum,revealing that recorded experimental currents were characteristic TRP-like channel currents.Identification of rat hippocampal mRNA transcripts of TRPC4,TRPC5,TRPV1,TRPV2,and TRPV3 channels further verified the expression of characteristic TRP-like channels on rat CA1hippocampal neurons.

  2. A Novel Strategy for TNF-Alpha Production by 2-APB Induced Downregulated SOCE and Upregulated HSP70 in O. tsutsugamushi-Infected Human Macrophages

    Science.gov (United States)

    Liang, Jui-Lin; Tsai, Ming-Hsien; Yen, Chia-Jung; Li, Hsiu-Wen; Chiu, Siou-Jin; Chang, Chung-Hsing; Huang, Yaw-Bin; Lin, Ming-Wei; Yoshioka, Tohru

    2016-01-01

    Orientia (O.) tsutsugamushi-induced scrub typhus is endemic across many regions of Asia and the Western Pacific, where an estimated 1 million cases occur each year; the majority of patients infected with O. tsutsugamushi end up with a cytokine storm from a severe inflammatory response. Previous reports have indicated that blocking tumor necrosis factor (TNF)-α reduced cell injury from a cytokine storm. Since TNF-α production is known to be associated with intracellular Ca2+ elevation, we examined the effect of store-operated Ca2+ entry (SOCE) inhibitors on TNF-α production in O. tsutsugamushi-infected macrophages. We found that 2-aminoethoxydiphenyl borate (2-APB), but not SKF96365, facilitates the suppression of Ca2+ mobilization via the interruption of Orai1 expression in O. tsutsugamushi-infected macrophages. Due to the decrease of Ca2+ elevation, the expression of TNF-α and its release from macrophages was repressed by 2-APB. In addition, a novel role of 2-APB was found in macrophages that causes the upregulation of heat shock protein 70 (HSP70) expression associated with ERK activation; upregulated TNF-α production in the case of knockdown HSP70 was inhibited with 2-APB treatment. Furthermore, elevated HSP70 formation unexpectedly did not help the cell survival of O. tsutsugamushi-infected macrophages. In conclusion, the parallelism between downregulated Ca2+ mobilization via SOCE and upregulated HSP70 after treatment with 2-APB against TNF-α production was found to efficiently attenuate an O. tsutsugamushi-induced severe inflammatory response. PMID:27472555

  3. TRPV3 channels mediate Ca²⁺ influx induced by 2-APB in mouse eggs.

    Science.gov (United States)

    Lee, Hoi Chang; Yoon, Sook-Young; Lykke-Hartmann, Karin; Fissore, Rafael A; Carvacho, Ingrid

    2016-01-01

    Fertilization in mammals is initiated when a sperm fuses with a mature MII oocyte, also known as egg, and triggers a plethora of finely controlled processes identified as egg activation. The completion of all events of egg activation is driven by and depends on a series of repetitive calcium (Ca(2+)) increases (Ca(2+) oscillations), which rely on Ca(2+) influx from the extracellular media. Ca(2+) channels on the egg plasma membrane (PM) are thought to mediate this influx. The TRP Ca(2+) channel TRPV3 is differentially expressed during oocyte maturation, being most active at the MII stage. Specific stimulation of TRPV3 channels promotes Ca(2+) influx sufficient to induce egg activation and parthenogenesis. Here, we explore the function and distribution dynamics of the TRPV3 channel protein during maturation. Using dsRNA, TrpV3 overexpression, and inhibitors of protein synthesis, we modified the expression levels of the channel and showed that the TRPV3 protein is synthesized and translocated to the PM during maturation. We demonstrated that 2-APB at the concentrations used here to promote Ca(2+) influx in eggs, specifically and reversibly targets TRPV3 channels without blocking IP3R1. Finally, we found that the activity of TRPV3 channels is dependent upon an intact actin cytoskeleton, suggesting an actin-based regulation of its expression and/or function on the PM. Collectively, our results show TRPV3 is a target of 2-APB in eggs, a condition that can be used to induce parthenogenesis. The need of an intact actin cytoskeleton for the function of TRPV3 channels in oocytes is a novel finding and suggests the rearrangements of actin that occur during maturation could regulate both the presence on the PM and/or the function of TRPV3 and of other Ca(2+) channels involved in oocyte maturation and fertilization. PMID:26725171

  4. The gap junction inhibitor 2-aminoethoxy-diphenyl-borate protects against acetaminophen hepatotoxicity by inhibiting cytochrome P450 enzymes and c-jun N-terminal kinase activation

    Energy Technology Data Exchange (ETDEWEB)

    Du, Kuo; Williams, C. David; McGill, Mitchell R.; Xie, Yuchao [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); Farhood, Anwar [Department of Pathology, St. David' s North Austin Medical Center, Austin, TX 78756 (United States); Vinken, Mathieu [Department of Toxicology, Center for Pharmaceutical Sciences, Vrije Universiteit Brussels, 1090 Brussels (Belgium); Jaeschke, Hartmut, E-mail: hjaeschke@kumc.edu [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States)

    2013-12-15

    Acetaminophen (APAP) hepatotoxicity is the leading cause of acute liver failure in the US. Although many aspects of the mechanism are known, recent publications suggest that gap junctions composed of connexin32 function as critical intercellular communication channels which transfer cytotoxic mediators into neighboring hepatocytes and aggravate liver injury. However, these studies did not consider off-target effects of reagents used in these experiments, especially the gap junction inhibitor 2-aminoethoxy-diphenyl-borate (2-APB). In order to assess the mechanisms of protection of 2-APB in vivo, male C56Bl/6 mice were treated with 400 mg/kg APAP to cause extensive liver injury. This injury was prevented when animals were co-treated with 20 mg/kg 2-APB and was attenuated when 2-APB was administered 1.5 h after APAP. However, the protection was completely lost when 2-APB was given 4–6 h after APAP. Measurement of protein adducts and c-jun-N-terminal kinase (JNK) activation indicated that 2-APB reduced both protein binding and JNK activation, which correlated with hepatoprotection. Although some of the protection was due to the solvent dimethyl sulfoxide (DMSO), in vitro experiments clearly demonstrated that 2-APB directly inhibits cytochrome P450 activities. In addition, JNK activation induced by phorone and tert-butylhydroperoxide in vivo was inhibited by 2-APB. The effects against APAP toxicity in vivo were reproduced in primary cultured hepatocytes without use of DMSO and in the absence of functional gap junctions. We conclude that the protective effect of 2-APB was caused by inhibition of metabolic activation of APAP and inhibition of the JNK signaling pathway and not by blocking connexin32-based gap junctions. - Highlights: • 2-APB protected against APAP-induced liver injury in mice in vivo and in vitro • 2-APB protected by inhibiting APAP metabolic activation and JNK signaling pathway • DMSO inhibited APAP metabolic activation as the solvent of 2-APB

  5. The gap junction inhibitor 2-aminoethoxy-diphenyl-borate protects against acetaminophen hepatotoxicity by inhibiting cytochrome P450 enzymes and c-jun N-terminal kinase activation

    International Nuclear Information System (INIS)

    Acetaminophen (APAP) hepatotoxicity is the leading cause of acute liver failure in the US. Although many aspects of the mechanism are known, recent publications suggest that gap junctions composed of connexin32 function as critical intercellular communication channels which transfer cytotoxic mediators into neighboring hepatocytes and aggravate liver injury. However, these studies did not consider off-target effects of reagents used in these experiments, especially the gap junction inhibitor 2-aminoethoxy-diphenyl-borate (2-APB). In order to assess the mechanisms of protection of 2-APB in vivo, male C56Bl/6 mice were treated with 400 mg/kg APAP to cause extensive liver injury. This injury was prevented when animals were co-treated with 20 mg/kg 2-APB and was attenuated when 2-APB was administered 1.5 h after APAP. However, the protection was completely lost when 2-APB was given 4–6 h after APAP. Measurement of protein adducts and c-jun-N-terminal kinase (JNK) activation indicated that 2-APB reduced both protein binding and JNK activation, which correlated with hepatoprotection. Although some of the protection was due to the solvent dimethyl sulfoxide (DMSO), in vitro experiments clearly demonstrated that 2-APB directly inhibits cytochrome P450 activities. In addition, JNK activation induced by phorone and tert-butylhydroperoxide in vivo was inhibited by 2-APB. The effects against APAP toxicity in vivo were reproduced in primary cultured hepatocytes without use of DMSO and in the absence of functional gap junctions. We conclude that the protective effect of 2-APB was caused by inhibition of metabolic activation of APAP and inhibition of the JNK signaling pathway and not by blocking connexin32-based gap junctions. - Highlights: • 2-APB protected against APAP-induced liver injury in mice in vivo and in vitro • 2-APB protected by inhibiting APAP metabolic activation and JNK signaling pathway • DMSO inhibited APAP metabolic activation as the solvent of 2-APB

  6. Effects of 2-APB on Store-operated Ca2+ Channel Currents of Hepatocytes after Hepatic Ischemia/Reperfusion Injury in Rats

    Institute of Scientific and Technical Information of China (English)

    HUANG Changzhou; ZHANG Zongming; QIU Fazu

    2005-01-01

    The effects of hepatic ischemia/reperfusion (I/R) injuries on hepatocellular viability and store-operated calcium current (Isoc) in isolated rat hepatocytes and the effects of 2-APB on storeoperated calcium current (Isoc) in isolated rat hepatocytes after hepaticischemia/reperfusion injuries were studied. Hepatic ischemia and reperfusion injury model was established and whole cell patch-clamp techniques were used to investigate the effects of 2-APB on Isoc. The results showed that ischemia/reperfusion injuries could significantly reduce hepatocellular viability and further increase Isoc in hepatocytes and 2-APB (20, 40, 60, 80, 100 μmol/L) produced a concentration-dependent decrease of Isoc with IC50 value of 64.63±10.56 μmol/L (n= 8). It was concluded that ischemia/reperfusion injuries could reduce hepatocellular viability, probably through increased Isoc in hepatocytes and 2-APB had a protective effect on ischemia/reperfusion-induced liver injury, probably though inhibiting Isoc.

  7. Analysis of zinc borates

    International Nuclear Information System (INIS)

    Methods for analyzing zinc borates: B2O3 determination in the presence of zinc ions and determination of zinc in the presence of borates are developed. Distributing effect of zinc in alcalometrical determination of B2O3 is removed using either its binding cationite KU-2 in H-form in hydrochloric acid medium or using complexone 3 masking. In the first case the results are underestimated, in the second one - are overestimated. When analyzing Zn the complexonometrical titration with sodium teraborate is carried out. Borate ions don't affect the accuracy of determination. Zinc borate samples of 0.1-0.15 g in dimesion are recommended according to the method suggested

  8. Borat vihastas ka rumeenlasi

    Index Scriptorium Estoniae

    2006-01-01

    Rumeenia mustlasküla Glod elanikud peavad endi solvamiseks viisi, kuidas neid ära kasutati Briti koomiku Sacha Baron Coheni loodud peategelasega USA filmi "Borat - kultuurialased õppetunnid Ameerikast abiks suursuguse Kasahstani riigi ülesehitamisel" võtetel

  9. Photon Interaction Parameters for Some Borate Glasses

    International Nuclear Information System (INIS)

    Some photon interaction parameters of dosimetric interest such as mass attenuation coefficients, effective atomic number, electron density and KERMA relative to air have been computed in the wide energy range from 1 keV to 100 GeV for some borate glasses viz. barium-lead borate, bismuth-borate, calcium-strontium borate, lead borate and zinc-borate glass. It has been observed that lead borate glass and barium-lead borate glass have maximum values of mass attenuation coefficient, effective atomic number and KERMA relative to air. Hence, these borate glasses are suitable as gamma ray shielding material, packing of radioactive sources etc.

  10. Photon Interaction Parameters for Some Borate Glasses

    Science.gov (United States)

    Mann, Nisha; Kaur, Updesh; Singh, Tejbir; Sharma, J. K.; Singh, Parjit S.

    2010-11-01

    Some photon interaction parameters of dosimetric interest such as mass attenuation coefficients, effective atomic number, electron density and KERMA relative to air have been computed in the wide energy range from 1 keV to 100 GeV for some borate glasses viz. barium-lead borate, bismuth-borate, calcium-strontium borate, lead borate and zinc-borate glass. It has been observed that lead borate glass and barium-lead borate glass have maximum values of mass attenuation coefficient, effective atomic number and KERMA relative to air. Hence, these borate glasses are suitable as gamma ray shielding material, packing of radioactive sources etc.

  11. Copper doped borate dosimeters revisited

    Energy Technology Data Exchange (ETDEWEB)

    Alajerami, Y.S.M. [Department of Physics, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Department of Medical Radiography, Al-Azhar University, Gaza Strip, Palestine (Country Unknown); Hashim, S., E-mail: suhairul@utm.my [Department of Physics, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Oncology Treatment Centre, Sultan Ismail Hospital, 81100 Johor Bahru (Malaysia); Ghoshal, S.K. [Department of Physics, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Bradley, D.A. [Centre for Nuclear and Radiation Physics, Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Mhareb, M. [Department of Physics, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Saleh, M.A. [Department of Physics, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); National Atomic Energy Commission (NATEC), Sana' a (Yemen)

    2014-11-15

    We render a panoramic overview on copper (Cu) doped borate dosimeters. Preparing a dosimeter by mixing specific materials with precise weights and methods is a never-ending quest. The recommended composition is highly decisive for accurate estimation of the absorbed dose, prediction of the biological outcome, determination of the treatment dose for radiation therapy and facilitation of personal monitoring. Based on these principles, the proposed dosimeter must cover a series of dosimetric properties to realize the exact results and assessment. The doped borate dosimeters indeed demonstrate attractive thermoluminescence (TL) features. Several dedicated efforts are attempted to improve the luminescence properties by doping various transition metals or rare-earth elements. The Cu ion being one of the preferred activators shows excellent TL properties as revealed via detail comparison with other dosimeters. Two oxide states of Cu (Cu{sup +} and Cu{sup ++}) with reasonable atomic number allow easy interaction with boron network. Interestingly, the intrinsic luminescent centers of borate lattice are in cross linked with that of Cu{sup +} ions. Thus, the activation of borate dosimeter with Cu ions for the enhancement of the TL sensitivity is recognized. These dosimeters reveal similar glow curves as the standard TLD-100 (LiF:Mg,Ti) one irrespective of the use of modifiers and synthesis techniques. They display high sensitivity, low fading, dose response linearity over wide range and practical minimum detectable dose. Furthermore, the effective atomic number being the most beneficial aspect (equivalent to that of human tissue) of borate dosimeters do not show any change due to Cu ion activations. The past development, major challenges, excitement, applications, recent progress and the future promises of Cu doped borate TL dosimeters are highlighted. - Highlights: • The manuscript gives a panoramic overview on copper doped borate dosimeters. • Cu ions activated

  12. "Borat" kogus tubli hulga vaatajaid

    Index Scriptorium Estoniae

    2006-01-01

    Briti koomiku Sacha Baron Coheni loodud peategelasega USA film "Borat - kultuurialased õppetunnid Ameerikast abiks suursuguse Kasahstani riigi ülesehitamisel" kogus Eesti kinolevis avanädalavahetusel 12 487 vaatajat (taasiseseisvumisaja neljas tulemus)

  13. Borate Minerals and RNA Stability

    Directory of Open Access Journals (Sweden)

    Ernesto Di Mauro

    2010-08-01

    Full Text Available The abiotic origin of genetic polymers faces two major problems: a prebiotically plausible polymerization mechanism and the maintenance of their polymerized state outside a cellular environment. The stabilizing action of borate on ribose having been reported, we have explored the possibility that borate minerals stabilize RNA. We observe that borate itself does not stabilize RNA. The analysis of a large panel of minerals tested in various physical-chemical conditions shows that in general no protection on RNA backbone is exerted, with the interesting exception of ludwigite (Mg2Fe3+BO5. Stability is a fundamental property of nucleic polymers and borate is an abundant component of the planet, hence the prebiotic interest of this analysis.

  14. Identification of TRPM7 channels in human intestinal interstitial cells of Cajal

    Institute of Scientific and Technical Information of China (English)

    Byung Joo Kim; Kyu Joo Park; Hyung Woo Kim; Seok Choi; Jae Yeoul Jun; In Youb Chang; Ju-Hong Jeon; Insuk So; Seon Jeong Kim

    2009-01-01

    AIM: To investigate the characteristics of slow electrical waves and the presence of transient receptor potential melastatin-type 7 (TRPM7) in the human gastrointestinal (GI) tract. METHODS: Conventional microelectrode techniques were used to record intracellular electrical responses from human GI smooth muscle tissue. Immunohistochemistry was used to identify TRPM7 channels in interstitial cells of Cajal (ICCs). RESULTS: The human GI tract generated slow electrical waves and had ICCs which functioned as pacemaker cells. Flufenamic acid, a nonselective cation channel blocker, and 2-APB (2-aminoethoxydiphenyl borate) and La3~+, TRPM7 channel blockers, inhibited the slow waves. Also, TRPM7 channels were expressed in ICCs in human tissue. CONCLUSION: These results suggest that the human GI tract generates slow waves and that TRPM7 channels expressed in the ICCs may be involved in the generation of the slow waves.

  15. Tere tulemast Eestisse, Borat Sagdijev! / Triin Tael

    Index Scriptorium Estoniae

    Tael, Triin

    2006-01-01

    Briti koomiku Sacha Baron Coheni loodud peategelasega USA film "Borat - kultuurialased õppetunnid Ameerikast abiks suursuguse Kasahstani riigi ülesehitamisel" esilinastub Eesti kinodes. Lisaks "Juut, kes mängib juudivihkajaid", "Borat ei taha kuningannaga seksida", "Vaene solvatud Kasahstan"

  16. Kes on Borat? / Timo Diener

    Index Scriptorium Estoniae

    Diener, Timo

    2006-01-01

    Eesti kinodesse on jõudnud briti koomiku Sacha Baron Coheni loodud peategelasega USA film "Borat - kultuurialased õppetunnid Ameerikast abiks suursuguse Kasahstani riigi ülesehitamisel" : režissöör Larry Charles. Filmi peaosalisest ja filmi seiklusrikkast võtteperioodist

  17. Conserved residues within the putative S4-S5 region serve distinct functions among thermosensitive vanilloid transient receptor potential (TRPV) channels.

    Science.gov (United States)

    Boukalova, Stepana; Marsakova, Lenka; Teisinger, Jan; Vlachova, Viktorie

    2010-12-31

    The vanilloid transient receptor potential channel TRPV1 is a tetrameric six-transmembrane segment (S1-S6) channel that can be synergistically activated by various proalgesic agents such as capsaicin, protons, heat, or highly depolarizing voltages, and also by 2-aminoethoxydiphenyl borate (2-APB), a common activator of the related thermally gated vanilloid TRP channels TRPV1, TRPV2, and TRPV3. In these channels, the conserved charged residues in the intracellular S4-S5 region have been proposed to constitute part of a voltage sensor that acts in concert with other stimuli to regulate channel activation. The molecular basis of this gating event is poorly understood. We mutated charged residues all along the S4 and the S4-S5 linker of TRPV1 and identified four potential voltage-sensing residues (Arg(557), Glu(570), Asp(576), and Arg(579)) that, when specifically mutated, altered the functionality of the channel with respect to voltage, capsaicin, heat, 2-APB, and/or their interactions in different ways. The nonfunctional charge-reversing mutations R557E and R579E were partially rescued by the charge-swapping mutations R557E/E570R and D576R/R579E, indicating that electrostatic interactions contribute to allosteric coupling between the voltage-, temperature- and capsaicin-dependent activation mechanisms. The mutant K571E was normal in all aspects of TRPV1 activation except for 2-APB, revealing the specific role of Lys(571) in chemical sensitivity. Surprisingly, substitutions at homologous residues in TRPV2 or TRPV3 had no effect on temperature- and 2-APB-induced activity. Thus, the charged residues in S4 and the S4-S5 linker contribute to voltage sensing in TRPV1 and, despite their highly conserved nature, regulate the temperature and chemical gating in the various TRPV channels in different ways.

  18. Ca2+ -regulated lysosome fusion mediates angiotensin II-induced lipid raft clustering in mesenteric endothelial cells.

    Science.gov (United States)

    Han, Wei-Qing; Chen, Wen-Dong; Zhang, Ke; Liu, Jian-Jun; Wu, Yong-Jie; Gao, Ping-Jin

    2016-04-01

    It has been reported that intracellular Ca2+ is involved in lysosome fusion and membrane repair in skeletal cells. Given that angiotensin II (Ang II) elicits an increase in intracellular Ca2+ and that lysosome fusion is a crucial mediator of lipid raft (LR) clustering, we hypothesized that Ang II induces lysosome fusion and activates LR formation in rat mesenteric endothelial cells (MECs). We found that Ang II acutely increased intracellular Ca2+ content, an effect that was inhibited by the extracellular Ca2+ chelator ethylene glycol tetraacetic acid (EGTA) and the inositol 1,4,5-trisphosphate (IP3)-induced Ca2+ release inhibitor 2-aminoethoxydiphenyl borate (2-APB). Further study showed that EGTA almost completely blocked Ang II-induced lysosome fusion, the translocation of acid sphingomyelinase (ASMase) to LR clusters, ASMase activation and NADPH (nicotinamide adenine dinucleotide phosphate) oxidase activation. In contrast, 2-APB had a slight inhibitory effect. Functionally, both the lysosome inhibitor bafilomycin A1 and the ASMase inhibitor amitriptyline reversed Ang II-induced impairment of vasodilation. We conclude that Ca2+ -regulated lysosome fusion mediates the Ang II-induced regulation of the LR-redox signaling pathway and mesenteric endothelial dysfunction.

  19. High-temperature borate crystal chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Bubnova, Rimma S. [Russian Academy of Sciences, St. Petersburg (Russian Federation). Grebenshchikov Institute of Silicate Chemistry; Saint Petersburg State Univ. (Russian Federation). Dept. of Crystallography; Filatov, Stanislav K. [Saint Petersburg State Univ. (Russian Federation). Dept. of Crystallography

    2013-10-01

    The paper presents a brief review of the present state of high-temperature borate crystal chemistry. This review summarizes the results of high- and low-temperature single crystal X-ray diffraction studies for more than 10 borate structures and high-temperature powder Xray diffraction data for about 65 borates. Thermal behavior of their crystal structures, thermal expansion, polymorphic transitions and their relationship to borate glasses are presented. These studies allow to formulate the basic principles of high-temperature borate crystal chemistry and to reveal the regularities of thermal behavior of borates. On heating, the BO{sub 3} and BO{sub 4} polyhedra and rigid groups consisting of these polyhedra, practically maintain their configuration and size, but they are able to rotate like hinges exhibiting highly anisotropic thermal expansion, including linear negative expansion. Based on these results, we generalize the term 'rigid group' and render thermal vibrations as the key ingredient for the self-assembly of borate rigid groups. (orig.)

  20. Lithium borate solid TL detectors

    International Nuclear Information System (INIS)

    A new procedure for the preparation of Li2B4O7:Cu,In and Li2B4O7:Cu,In,Ag in form of sintered pellets has been developed recently at the Institute of Nuclear Sciences Vinca, Belgrade. Very few TL materials are tissue equivalent with an effective atomic number which is very close to that of soft biological tissue (7.4). Li2B4O7 based TL dosemeters appeared to be among the most attractive, with an effective atomic number of 7.3. The thermoluminescence properties of lithium borate in form of sintered TLD pellets examined in this study include glow-curve shapes, TL sensitivity, photon dose response, minimum detectable dose, relative photon energy response, fading, reproducibility, uniformity, recommended annealing procedure and kinetic parameters. (author)

  1. Repliik filmi "Borat" kohta / Urve Kirss

    Index Scriptorium Estoniae

    Kirss, Urve

    2007-01-01

    Briti koomiku Sacha Baron Coheni loodud peategelasega USA film "Borat - kultuurialased õppetunnid Ameerikast abiks suursuguse Kasahstani riigi ülesehitamisel" : režissöör Larry Charles. Vaataja mõtteid

  2. Tribological performance of nanometer samarium borate

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Nanometer crystal samarium borate with a particle size of 20~40 nm was prepared using replacing solvent drying technique. The wear resistance and load-carrying capacity of 500SN base oil could be improved and the friction coefficient could be decreased by the addition of nanometer samarium borate. But the dosage of samarium borate nanoparticles had to be controlled at a relatively low level, a higher concentration of nanoparticles was not of beneficial to the tribological performance of the oil. The optimal dosage of nanometer samarium borate is 1.0%. Tribochemical reactions took place in the tribological process, which resulted in the formation of deposition products including diboron trioxide and disamarium trioxide. Fe2B and FeB were also found on the wear scar. The improvement of tribological properties of the oil comes from the formation of deposition layer and permeating layer.

  3. Recent progress in actinide borate chemistry.

    Science.gov (United States)

    Wang, Shuao; Alekseev, Evgeny V; Depmeier, Wulf; Albrecht-Schmitt, Thomas E

    2011-10-21

    The use of molten boric acid as a reactive flux for synthesizing actinide borates has been developed in the past two years providing access to a remarkable array of exotic materials with both unusual structures and unprecedented properties. [ThB(5)O(6)(OH)(6)][BO(OH)(2)]·2.5H(2)O possesses a cationic supertetrahedral structure and displays remarkable anion exchange properties with high selectivity for TcO(4)(-). Uranyl borates form noncentrosymmetric structures with extraordinarily rich topological relationships. Neptunium borates are often mixed-valent and yield rare examples of compounds with one metal in three different oxidation states. Plutonium borates display new coordination chemistry for trivalent actinides. Finally, americium borates show a dramatic departure from plutonium borates, and there are scant examples of families of actinides compounds that extend past plutonium to examine the bonding of later actinides. There are several grand challenges that this work addresses. The foremost of these challenges is the development of structure-property relationships in transuranium materials. A deep understanding of the materials chemistry of actinides will likely lead to the development of advanced waste forms for radionuclides present in nuclear waste that prevent their transport in the environment. This work may have also uncovered the solubility-limiting phases of actinides in some repositories, and allows for measurements on the stability of these materials. PMID:21915396

  4. Bioactive borate glass coatings for titanium alloys.

    Science.gov (United States)

    Peddi, Laxmikanth; Brow, Richard K; Brown, Roger F

    2008-09-01

    Bioactive borate glass coatings have been developed for titanium and titanium alloys. Glasses from the Na(2)O-CaO-B(2)O(3) system, modified by additions of SiO(2), Al(2)O(3), and P(2)O(5), were characterized and compositions with thermal expansion matches to titanium were identified. Infrared and X-ray diffraction analyses indicate that a hydroxyapatite surface layer forms on the borate glasses after exposure to a simulated body fluid for 2 weeks at 37 degrees C; similar layers form on 45S5 Bioglass((R)) exposed to the same conditions. Assays with MC3T3-E1 pre-osteoblastic cells show the borate glasses exhibit in vitro biocompatibility similar to that of the 45S5 Bioglass((R)). An enameling technique was developed to form adherent borate glass coatings on Ti6Al4V alloy, with adhesive strengths of 36 +/- 2 MPa on polished substrates. The results show these new borate glasses to be promising candidates for forming bioactive coatings on titanium substrates.

  5. Green colorants based on energetic azole borates.

    Science.gov (United States)

    Glück, Johann; Klapötke, Thomas M; Rusan, Magdalena; Stierstorfer, Jörg

    2014-11-24

    The investigation of green-burning boron-based compounds as colorants in pyrotechnic formulations as alternative for barium nitrate, which is a hazard to health and to the environment, is reported. Metal-free and nitrogen-rich dihydrobis(5-aminotetrazolyl)borate salts and dihydrobis(1,3,4-triazolyl)borate salts have been synthesized and characterized by NMR spectroscopy, elemental analysis, mass spectrometry, and vibrational spectroscopy. Their thermal and energetic properties have been determined as well. Several pyrotechnic compositions using selected azolyl borate salts as green colorants were investigated. Formulations with ammonium dinitramide and ammonium nitrate as oxidizers and boron and magnesium as fuels were tested. The burn time, dominant wavelength, spectral purity, luminous intensity, and luminous efficiency as well as the thermal and energetic properties of these compositions were measured. PMID:25284439

  6. Recent progress in actinide borate chemistry

    OpenAIRE

    Wang, S.; Alekseev, E .V.; Depmeier, W.; Albrecht-Schmitt, T.E.

    2011-01-01

    The use of molten boric acid as a reactive flux for synthesizing actinide borates has been developed in the past two years providing access to a remarkable array of exotic materials with both unusual structures and unprecedented properties. [ThB(5)O(6)(OH)(6)][BO(OH)(2)]·2.5H(2)O possesses a cationic supertetrahedral structure and displays remarkable anion exchange properties with high selectivity for TcO(4)(-). Uranyl borates form noncentrosymmetric structures with extraordinarily rich topol...

  7. A crystal-chemical classification of borate structures with emphasis on hydrated borates

    Science.gov (United States)

    Christ, C.L.; Clark, J.R.

    1977-01-01

    The rules governing formation of hydrated borate polyanions that were proposed by C.L. Christ in 1960 are critically reviewed and new rules added on the basis of recent crystal structure determinations. Principles and classifications previously published by others are also critically reviewed briefly. The fundamental building blocks from which borate polyanions can be constructed are defined on the basis of the number n of boron atoms, and the fully hydrated polyanions are illustrated. Known structures are grouped accordingly, and a shorthand notation using n and symbols ?? = triangle, T = tetrahedron is introduced so that the polyanions can be easily characterized. For example, 3:??+2T describes [B3O3(OH)5]2-. Correct structural formulas are assigned borates with known structures whereas borates of unknown structure are grouped separately. ?? 1977 Springer-Verlag.

  8. Structural properties of Zinc Lithium borate glass

    Science.gov (United States)

    Saidu, A.; Wagiran, H.; Saeed, M. A.; Alajerami, Y. S. M.

    2014-09-01

    Zinc Lithium Borate glasses of different composition were prepared with the aim of using it for thermoluminescence dosimetry. Melt quenching method was adopted in this process. Fourier transform Infrared (FTIR) spectroscopy and UV-vis-NIR spectroscopy techniques were employed to investigate the infrared spectra and energy band gap of different composition of Zinc Lithium Borate glasses. X-ray diffraction analysis was used to confirm the amorphous nature of the glass samples. Glass forming ability and stability of the glass was checked using Differential thermal analysis (DTA). Density, molar volume, refractive index parameters have been analyzed in the light of different concentration of the modifier. The active vibrational modes of 1200-1600 cm-1 for B-O stretching of BO3 units, 800-1200 cm-1 for B-O stretching of BO4 units and 400-800 cm-1 for bending vibration of various borate segments were detected. Addition of ZnO to lithium borate shows its influence in converting the dominant BO3 group to BO4 group. BO4 are known for creating complex defects, a situation that established deep and stable traps good for thermoluminescence phenomena. From optical data, direct and indirect energy band gap has been calculated using the data obtained from UV-vis-NIR spectroscopy. Both direct and indirect band gaps decrease with the increase of modifier Li2CO3.

  9. Dielectric Properties of Some Borate Glasses

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The dielectric constant, ε', and the dielectric loss, ε", forsome selected lead borate glasses within the frequency band 105 to 107 Hz and the temperature range (20~50)℃ were measured. The dielectric dispersion and the dielectric loss absorption bands were observed, the relaxation time,the activation enthalpy and entropy change of the dielectric relaxation were calculated. The results obtained were discussed and correlated to the internal network structure of the glasses studied.

  10. Hydrogen-ion sputtering of borated graphite

    International Nuclear Information System (INIS)

    The development and choice of material for the first wall and other energy-stressed parts of the discharge chamber are an important aspect of fusion reactor construction. In particular, carbon-graphite materials are proposed for making limiters and protective shields of the first wall and receiving plates of diverter devices. Sputtering under ion bombardment is one of the main mechanisms of material erosion; in addition, in the case of carbon-graphite materials chemical sputtering also occurs as a result of the formation of highly volatile hydrocarbon compounds during the reaction with ions of hydrogen isotopes. Sputtering MPG carbon-graphite materials and USB-15 carbon-fiber-reinforced glass ceramic has been well studied and experimental data have been obtained on the coefficients of physical and chemical sputtering. It has been determined that hydrogen-ion sputtering of USB-15 in the range from room temperature to 1070 K is less than that of MPG-8 graphite a factor of 2-10. Bulk doping of graphite with boron substantially reduces chemical sputtering. Since processes in the surface layers are crucially important in sputtering, the possibility of reducing chemical sputtering by surface boration of carbon-graphite materials has been explored. The objective of this work was to continue the experimental investigation to determine the physical processes of sputtering of surface-borated graphite under hydrogen-ion bombardment in the temperature range corresponding to maximum chemical sputtering. Surface boration of MPG-8 and USB-15 samples was carried out by vapor-phase isothermal deposition mediated by gaseous iodine at 1223 K for 4 h (the sample was placed in a pure boron stock). The mass transfer during the vapor-phase deposition is based on the difference of the chemical potentials of iodine and carbon under isothermal conditions. The samples of the initial and borated carbon-graphite materials irradiated with a poly-energetic beam of hydrogen ions

  11. Coarsening kinetics in demixed lead borate melts.

    Science.gov (United States)

    Dittmar, A; Bornhöft, H; Deubener, J

    2013-06-14

    Lead borate melts have been demixed at temperatures in range from 723 to 773 K for times up to 20 h. It is found that increasing time and temperature lead to characteristic changes in the size distribution of boron trioxide drops in the lead-rich glassy matrix (cube root time dependence of diffusion controlled coarsening. The diffusivity of the coarsening process was determined using liquid-liquid interfacial energy associated with drop deformation in glass specimens subjected to uniaxial compression. Diffusion coefficients of coarsening were found to match with those of (207)Pb and (18)O tracer ions in the lead borate system but differ up to four orders of magnitude from the Eyring diffusivity and by a factor of ≈7 from the activation energy of viscous flow. The results indicate that coarsening in demixed lead borate melts is most likely controlled by the short range dynamics of the interaction between lead cations and BO4 units, which are decoupled from the time scales of cooperative rearrangements of the glassy network at T < 1.1 Tg. PMID:23781800

  12. Geological features and genesis of Gaotaigou borate deposit, Jilin, China

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Gaotaigou borate deposit in Ji'an area, southeastern Jilin, is located in the easten end of Liaoning-Jilin (Liaoji)Proterozoic paleo-rift, which is a medium-sized deposit and makes up 67% of the total borate reserves in Jilin Province.The original borate ore bodies were formed by sedimentary exhalative process in Paleoproterozoic, but were activated and enriched by later metamorphism. In late stage of metamorphism, hydrothermal fluid of metamorphic origin made wallrocks be altered and the borate ore bodies be reformed. Ore bodies are strictly controlled by strata and their lithologies. In addition, the shape and spatial distribution of ore bodies are also defined by the Gaotaigou syncline. Combined with the ore-controlling factors and mineralizing features, it has been proposed that Gaotaigou borate deposit is a metamorphosed and hydrothermally altered sedimentary exhalative deposit.

  13. Density of mixed alkali borate glasses: A structural analysis

    Energy Technology Data Exchange (ETDEWEB)

    Doweidar, H. [Glass Research Group, Physics Department, Faculty of Science, Mansoura University, P.O. Box 83, Mansoura 35516 (Egypt)]. E-mail: hdoweidar@mans.edu.eg; El-Damrawi, G.M. [Glass Research Group, Physics Department, Faculty of Science, Mansoura University, P.O. Box 83, Mansoura 35516 (Egypt); Moustafa, Y.M. [Glass Research Group, Physics Department, Faculty of Science, Mansoura University, P.O. Box 83, Mansoura 35516 (Egypt); Ramadan, R.M. [Glass Research Group, Physics Department, Faculty of Science, Mansoura University, P.O. Box 83, Mansoura 35516 (Egypt)

    2005-05-15

    Density of mixed alkali borate glasses has been correlated with the glass structure. It is assumed that in such glasses each alkali oxide associates with a proportional quantity of B{sub 2}O{sub 3}. The number of BO{sub 3} and BO{sub 4} units related to each type of alkali oxide depends on the total concentration of alkali oxide. It is concluded that in mixed alkali borate glasses the volumes of structural units related to an alkali ion are the same as in the corresponding binary alkali borate glass. This reveals that each type of alkali oxide forms its own borate matrix and behaves as if not affected with the presence of the other alkali oxide. Similar conclusions are valid for borate glasses with three types of alkali oxide.

  14. Synthesis of borate cross-linked rhamnogalacturonan II.

    Science.gov (United States)

    Funakawa, Hiroya; Miwa, Kyoko

    2015-01-01

    In the present review, we describe current knowledge about synthesis of borate crosslinked rhamnogalacturonan II (RG-II) and it physiological roles. RG-II is a portion of pectic polysaccharide with high complexity, present in primary cell wall. It is composed of homogalacturonan backbone and four distinct side chains (A-D). Borate forms ester bonds with the apiosyl residues of side chain A of two RG-II monomers to generate borate dimerized RG-II, contributing for the formation of networks of pectic polysaccharides. In plant cell walls, more than 90% of RG-II are dimerized by borate under boron (B) sufficient conditions. Borate crosslinking of RG-II in primary cell walls, to our knowledge, is the only experimentally proven molecular function of B, an essential trace-element. Although abundance of RG-II and B is quite small in cell wall polysaccharides, increasing evidence supports that RG-II and its borate crosslinking are critical for plant growth and development. Significant advancement was made recently on the location and the mechanisms of RG-II synthesis and borate cross-linking. Molecular genetic studies have successfully identified key enzymes for RG-II synthesis and regulators including B transporters required for efficient formation of RG-II crosslinking and consequent normal plant growth. The present article focuses recent advances on (i) RG-II polysaccharide synthesis, (ii) occurrence of borate crosslinking and (iii) B transport for borate supply to RG-II. Molecular mechanisms underlying formation of borate RG-II crosslinking and the physiological impacts are discussed. PMID:25954281

  15. Synthesis of borate cross-linked rhamnogalacturonan II

    Directory of Open Access Journals (Sweden)

    Hiroya eFunakawa

    2015-04-01

    Full Text Available In the present review, we describe current knowledge about synthesis of borate crosslinked rhamnogalacturonan II (RG-II and it physiological roles. RG-II is a portion of pectic polysaccharide with high complexity, present in primary cell wall. It is composed of homogalacturonan backbone and four distinct side chains (A-D. Borate forms ester bonds with the apiosyl residues of side chain A of two RG-II monomers to generate borate dimerized RG-II, contributing for the formation of networks of pectic polysaccharides. In plant cell walls, more than 90% of RG-II are dimerized by borate under B sufficient conditions. Borate crosslinking of RG-II in primary cell walls, to our knowledge, is the only experimentally proven molecular function of boron (B, an essential trace-element. Although abundance of RG-II and B is quite small in cell wall polysaccharides, increasing evidence supports that RG-II and its borate crosslinking are critical for plant growth and development. Significant advancement was made recently on the location and the mechanisms of RG-II synthesis and borate cross-linking. Molecular genetic studies have successfully identified key enzymes for RG-II synthesis and regulators including B transporters required for efficient formation of RG-II crosslinking and consequent normal plant growth. The present article focuses recent advances on (i RG-II polysaccharide synthesis, (ii occurrence of borate crosslinking and (iii B transport for borate supply to RG-II. Molecular mechanisms underlying formation of borate RG-II crosslinking and the physiological impacts are discussed.

  16. ULTRASONIC AND HYPERSONIC BEHAVIOURS OF BORATE GLASSES

    OpenAIRE

    Carini, Giovanni; Tripodo, Gaspare; Borjesson, Lars; Zanghellini, Ezio; A BARTOLOTTA

    2007-01-01

    Abstract Comparative measurements of Brillouin light scattering and ultrasounds in (K2O)0.04(B2O3)0.96 and (Ag2O)0.14(B2O3)0.86 borate glasses as a function of temperature between 1.5 and 300 K reveal that distinct mechanisms regulate the temperature behaviours of the acoustic attenuation. In the MHz range the attenuation and the sound velocity are mainly governed by (i) quantum-mechanical tunnelling below 20 K, (ii) thermally activated relaxations between 20 and 200 K and (iii) vi...

  17. Important role of PLC-γ1 in hypoxic increase in intracellular calcium in pulmonary arterial smooth muscle cells.

    Science.gov (United States)

    Yadav, Vishal R; Song, Tengyao; Joseph, Leroy; Mei, Lin; Zheng, Yun-Min; Wang, Yong-Xiao

    2013-02-01

    An increase in intracellular calcium concentration ([Ca(2+)](i)) in pulmonary arterial smooth muscle cells (PASMCs) induces hypoxic cellular responses in the lungs; however, the underlying molecular mechanisms remain incompletely understood. We report, for the first time, that acute hypoxia significantly enhances phospholipase C (PLC) activity in mouse resistance pulmonary arteries (PAs), but not in mesenteric arteries. Western blot analysis and immunofluorescence staining reveal the expression of PLC-γ1 protein in PAs and PASMCs, respectively. The activity of PLC-γ1 is also augmented in PASMCs following hypoxia. Lentiviral shRNA-mediated gene knockdown of mitochondrial complex III Rieske iron-sulfur protein (RISP) to inhibit reactive oxygen species (ROS) production prevents hypoxia from increasing PLC-γ1 activity in PASMCs. Myxothiazol, a mitochondrial complex III inhibitor, reduces the hypoxic response as well. The PLC inhibitor U73122, but not its inactive analog U73433, attenuates the hypoxic vasoconstriction in PAs and hypoxic increase in [Ca(2+)](i) in PASMCs. PLC-γ1 knockdown suppresses its protein expression and the hypoxic increase in [Ca(2+)](i). Hypoxia remarkably increases inositol 1,4,5-trisphosphate (IP(3)) production, which is blocked by U73122. The IP(3) receptor (IP(3)R) antagonist 2-aminoethoxydiphenyl borate (2-APB) or xestospongin-C inhibits the hypoxic increase in [Ca(2+)](i). PLC-γ1 knockdown or U73122 reduces H(2)O(2)-induced increase in [Ca(2+)](i) in PASMCs and contraction in PAs. 2-APB and xestospongin-C produce similar inhibitory effects. In conclusion, our findings provide novel evidence that hypoxia activates PLC-γ1 by increasing RISP-dependent mitochondrial ROS production in the complex III, which causes IP(3) production, IP(3)R opening, and Ca(2+) release, playing an important role in hypoxic Ca(2+) and contractile responses in PASMCs.

  18. Potentiation of nerve growth factor-induced neurite outgrowth in PC12 cells by ifenprodil: the role of sigma-1 and IP3 receptors.

    Directory of Open Access Journals (Sweden)

    Tamaki Ishima

    Full Text Available In addition to both the α1 adrenergic receptor and N-methyl-D-aspartate (NMDA receptor antagonists, ifenprodil binds to the sigma receptor subtypes 1 and 2. In this study, we examined the effects of ifenprodil on nerve growth factor (NGF-induced neurite outgrowth in PC12 cells. Ifenprodil significantly potentiated NGF-induced neurite outgrowth, in a concentration-dependent manner. In contrast, the α1 adrenergic receptor antagonist, prazosin and the NMDA receptor NR2B antagonist, Ro 25-6981 did not alter NGF-induced neurite outgrowth. Potentiation of NGF-induced neurite outgrowth mediated by ifenprodil was significantly antagonized by co-administration of the selective sigma-1 receptor antagonist, NE-100, but not the sigma-2 receptor antagonist, SM-21. Similarly, ifenprodil enhanced NGF-induced neurite outgrowth was again significantly reduced by the inositol 1,4,5-triphosphate (IP(3 receptor antagonists, xestospongin C and 2-aminoethoxydiphenyl borate (2-APB treatment. Furthermore, BAPTA-AM, a chelator of intracellular Ca(2+, blocked the effects of ifenprodil on NGF-induced neurite outgrowth, indicating the role of intracellular Ca(2+ in the neurite outgrowth. These findings suggest that activation at sigma-1 receptors and subsequent interaction with IP(3 receptors may mediate the pharmacological effects of ifenprodil on neurite outgrowth.

  19. Calcium oscillations in human mesenteric vascular smooth muscle.

    Science.gov (United States)

    Navarro-Dorado, Jorge; Garcia-Alonso, Mauricio; van Breemen, Cornelis; Tejerina, Teresa; Fameli, Nicola

    2014-02-28

    Phenylephrine (PE)-induced oscillatory fluctuations in intracellular Ca(2+) concentration ([Ca(2+)]i) of vascular smooth muscle have been observed in many blood vessels isolated from a wide variety of mammals. Paradoxically, until recently similar observations in humans have proven elusive. In this study, we report for the first time observations of adrenergically-stimulated [Ca(2+)]i oscillations in human mesenteric artery smooth muscle. In arterial segments preloaded with Fluo-4 AM and mounted on a myograph on the stage of a confocal microscope, we observed PE-induced oscillations in [Ca(2+)]i, which initiated and maintained vasoconstriction. These oscillations present some variability, possibly due to compromised health of the tissue. This view is corroborated by our ultrastructural analysis of the cells, in which we found only (5 ± 2)% plasma membrane-sarcoplasmic reticulum apposition, markedly less than measured in healthy tissue from laboratory animals. We also partially characterized the oscillations by using the inhibitory drugs 2-aminoethoxydiphenyl borate (2-APB), cyclopiazonic acid (CPA) and nifedipine. After PE contraction, all drugs provoked relaxation of the vessel segments, sometimes only partial, and reduced or inhibited oscillations, except CPA, which rarely caused relaxation. These preliminary results point to a potential involvement of the sarcoplasmic reticulum Ca(2+) and inositol 1,4,5-trisphosphate receptor (IP3R) in the maintenance of the Ca(2+) oscillations observed in human blood vessels. PMID:24508261

  20. [Raman and infrared spectrograms of organic borate intercalated hydrotalcite].

    Science.gov (United States)

    Zhang, Jing-Yu; Bai, Zhi-Min; Zhao, Dong

    2013-03-01

    The pattern of X-ray diffraction, the Raman and infrared spectra of organic borate intercalated hydrotalcite were discussed. The well crystallized zinc-aluminum layered double hydroxides (Zn-Al LDHs) intercalated by carbonate ions and borate ions were respectively prepared by co-precipitation method. Patterns of X-ray diffraction showed that the (003) reflection of borate-LDHs was sharp and symmetric and shifted to lower angle than that of carbonate-LDHs. The gallery height of borate-LDHs increased from 0. 28 nm to 0.42 nm after intercalation, indicating that interlayered carbonate ions were substituted by borate anions. The Raman and IR spectra showed that specific bands of carbonate ions in the borate-LDHs disappeared, but with the presence of B3O3(OH)4- X B4O5(OH)4(2-) and B(OH)4- in the interlayer galleries. The hydroxide interlayer anions had a significant influence on the band positions in Raman and infrared spectra of modes related to the hydroxyl group. Our results indicate that single phase and pure borate-pillared LDHs can be obtained using tributyl orthoborate as intercalating agents, and the change in the structure and nature of hydrotalcite can be detected precisely by Raman spectroscopy. PMID:23705437

  1. Towards modeling gadolinium-lead-borate glasses

    International Nuclear Information System (INIS)

    Infrared spectra of gadolinium-lead-borate glasses of the xGd2O3.(100 - x)[3B2O3.PbO] system, where x = 0, 5, 10, 15, 25, 35 and 50 mol.%, have been recorded to explore the role of content of gadolinium ions behaving as glass modifier. The FTIR spectroscopy data for the xGd2O3.(1 - x)[3B2O3.PbO] glasses show the structural role of lead ions as a network-formers and of the gadolinium ions network modifiers. Adding of the rare earth ion up to 35 mol.% into the glass matrix, the IR bands characteristic to the studied glasses become sharper and more pronounced. Structural changes, as recognized by analyzing band shapes of IR spectra, revealed that Gd2O3 causes a change from the continuous borate network to the continuous lead-borate network interconnected through Pb-O-B and B-O-B bridges and the transformation of some tetrahedral [BO4] units into trigonal [BO3] units. Then, gadolinium ions have affinity towards [BO3] structural units which contain non-bridging oxygens necessary for the charge compensation because the more electronegative [BO3] structural units were implied in the formation of B-O-Gd bonds and the transformation of glass network into a glass ceramic. We propose a possible structural model of building blocks for the formation of continuous random 3B2O3.PbO network glass used by density functional theory (DFT) calculations. DFT calculations show that lead atoms occupy three different sites in the proposed model. The first is coordinated with six oxygen atoms forming distorted octahedral geometries. The second lead atom has an octahedral oxygen environment and the five longer Pb-O bonds are considered as participating in the metal coordination scheme. The third lead atom has ionic character. In agreement with the results offered by the experimental FTIR data, the theoretical IR data confirm that our proposed structure is highly possible.

  2. Borat tungib psüühesse / Rain Tolk

    Index Scriptorium Estoniae

    Tolk, Rain, 1977-

    2006-01-01

    Briti koomik Sacha Baron Cohen ja tema loodud peategelasega film "Borat - kultuurialased õppetunnid Ameerikast abiks suursuguse Kasahstani riigi ülesehitamisel", režissöör Larry Charles : Ameerika Ühendriigid 2006

  3. DVD. Borat - ühiskonna sanitar / Tiit Tuumalu

    Index Scriptorium Estoniae

    Tuumalu, Tiit, 1971-

    2007-01-01

    Lühiarvustus DVDl ilmunud filmile "Borat - kultuurialased õppetunnid Ameerikast abiks suursuguse Kasahstani riigi ülesehitamisel" : režissöör Larry Charles, peaosas Sacha Baron Cohen : Ameerika Ühendriigid 2006

  4. ІNVESTIGATION OF PECULIARITIES OF PISTON RINGS LASER BORATING

    Directory of Open Access Journals (Sweden)

    BOLSHAKOV V. I.

    2015-11-01

    Full Text Available Problem formulation. Piston rings are subject to wear while in operation. Insufficient wear resistance of materials limits the growth of machines productivity as well as the terms of their exploitation. The required complex of properties of piston rings made of cast iron cannot be always reached by applying traditional methods of heat treatment or chemical heat treatment processing. Thus, application of traditional borating methods associated with diffusion of boron into the solid phase leads to the formation of the working layer exhibiting high brittleness. Therefore, the problem of increasing the wear resistance of piston rings without embrittlement is challenging. The use oflaser heating during borating provides the formation of a new layer with special properties. However, the optimum properties can be achieved only after determining the relationship between the parameters of running a process and the depth of the borated layer. Goal of research. To determine the influence of laser heating parameters on the depth of the borated layer, as the properties of piston rings depend on the depth of the latter. Conclusions. Increase in the speed of displacing parts during laser heating reduces the depth of the borated layer, and increase of the spot diameter enhances the depth of the layer. The phases and structural components of the borated layer were interpreted by means of X-ray and metallographic methods. The results of investigations can be applied to other machine parts, which are subject to intensive wear.

  5. The cytotoxicity of NiO nanoparticle with borate capping.

    Science.gov (United States)

    Liu, Zunjing; Wang, Yongjing; Pan, Danmei; Chen, Zhi; Pan, Xiaohong; Wang, Yonghao; Lin, Zhang

    2011-11-01

    The impact of surface capping on cytotoxicity of NiO nanoparticle was investigated with Escherichia coil (E.coli) in this work. The NiO nanoparticle and NiO nanoparticle capped by borate (denoted as NiO-borate) were synthesized by hydrothermal method. The average size of both nanoparticles is about 4.0 nm. The plate experiments demonstrated that NiO-borate nanoparticles show lower cytotoxicity than NiO nanopaticles. Further spectrophotometric analysis revealed that the concentration of both extracellular and intercellular Ni2+ in NiO-borate system were lower than that of uncapped one. Intracellular ICP-AES analysis also showed the concentration of Ni element was higher than Ni2+, suggesting the NiO nanoparticles might penetrate into the cellular interior. Comprehensive AFM, SEM and TEM observation illustrated both NiO-borate and NiO nanoparticles lead to the collapse of cellular body, the convex on the cell wall and the damage of cell wall ultimately. In summary, the surface capping with borate on NiO nanopaticles will suppress the release of the Ni2+ ions and impede the contact between the NiO nanoparticle and cell wall, which ultimately decreased the cytotoxicity of NiO nanoparticles.

  6. Kinetic parameters and TL mechanism in cadmium tetra borate phosphor

    Energy Technology Data Exchange (ETDEWEB)

    Annalakshmi, O. [Radiological Safety Division, Materials Physics Division, Indira Gandhi Centre for Atomic Research, Kalpakkam-603102 (India); Jose, M.T., E-mail: mtj@igcar.gov.in [Radiological Safety Division, Materials Physics Division, Indira Gandhi Centre for Atomic Research, Kalpakkam-603102 (India); Sridevi, J. [Central Leather Research Institute, Council of Scientific and Industrial Research, Chennai 600 020, Tamilnadhu (India); Venkatraman, B. [Radiological Safety Division, Materials Physics Division, Indira Gandhi Centre for Atomic Research, Kalpakkam-603102 (India); Amarendra, G. [Materials Physics Division, Indira Gandhi Centre for Atomic Research, Kalpakkam-603102 (India); Mandal, A.B. [Central Leather Research Institute, Council of Scientific and Industrial Research, Chennai 600 020, Tamilnadhu (India)

    2014-03-15

    Polycrystalline powder samples of cadmium tetra borate were synthesized by a simple solid state sintering technique and gamma irradiated sample showed a simple Thermoluminescence (TL) glow peak around 460 K. The TL kinetic parameters of gamma irradiated phosphor were determined by initial rise (IR), isothermal decay (ID), peak shape (PS), variable heating rate (VHR) and glow curve de-convolution method. The kinetic parameters such as activation energy (E), frequency factor (s) and order of kinetics (b) were calculated by IR, ID, PS and VHR methods are in the order of ∼1.05 eV, 10{sup 9}–10{sup 12} s{sup −1} and 1.58, respectively. From the results of TL and PL emission studies carried out on the phosphor revealed that the defect centers related to TL is different from that for PL. EPR measurements were carried out to identify the defect centers formed in cadmium tetra borate phosphor on gamma irradiation. Based on EPR studies the mechanism for TL process in cadmium tetra borate is proposed in this paper -- Highlights: • Polycrystalline powder samples of undoped cadmium tetra borate synthesized. • Cadmium tetra borate phosphor exhibits a dosimetric peak at 458 K. • Kinetic parameters of the trap responsible for TL evaluated. • TL mechanism is proposed from TL to EPR correlation studies.

  7. Photon-Induced Borate Groups Transformation by Femtosecond Laser

    Institute of Scientific and Technical Information of China (English)

    杨晓燕; 余昺鲲; 姜雄伟; 曾慧丹

    2003-01-01

    In this paper, we put emphasis on the analysis the mechanism of the photon-induced frequency conversion β-BaB2O4 crystal inside a borate glass using femtosecond laser. Because of the nature of femtosecond laser's ultra-short pulse duration and high-energy density, in essence the laser-glass interaction mechanism is changed. Based on multiphoton ionization, collisional ionization and the network depolymerization in the borate glass, production of the plasma drives the microstructure rearrangement near the laser beam focusing area. From the structure of glass and crystal analysis, we conclude that the complicated borate groups containing BO3 and BO4 units inside the glass are converted into(B3O6)-3 anion rings.

  8. Lead Oxychloride Borates Obtained under Extreme Conditions.

    Science.gov (United States)

    Siidra, Oleg I; Kabbour, Houria; Mentre, Olivier; Nazarchuk, Evgeny V; Kegler, Philip; Zinyakhina, Diana O; Colmont, Marie; Depmeier, Wulf

    2016-09-01

    [Pb10O4]Pb2(B2O5)Cl12 (1) and [Pb18O12]Pb(BO2OH)2Cl10 (2) were obtained via high-temperature high-pressure experiments. [O12Pb18](12+) and [O4Pb10](12+) oxocentered structural units of different dimensionality are excised from the ideal [OPb] layer in tetragonal α-PbO. 2 is formed with an excess of lead oxide component, and 1 is formed with an excess of borate and halide reagents. The structure of 2 can be visualized as the incorporation of {Pb(10)Cl4(BO2OH)2} clusters into alternating PbO and chloride layers, with the existence of square vacancies in both. However, the structure of 1 is described as the intrusion of [O4Pb10](12+) tetramers linked by disordered Pb(B2O5) groups into a halogen three-dimensional matrix. The structure of 2 contains 10 symmetrically independent Pb positions. The 6s(2) lone electron pair is stereochemically active on Pb(1)-Pb(9) atoms, whereas it is inert on Pb(10). All of the Pb coordinations in the structure of 2, in accordance with ECCv (volume eccentricity) parameters and the density of states (DOS), can be subdivided into three groups. The current study is the first attempt to analyze this unusual behavior in structurally complex oxyhalide material with the rare case of Pb(2+) cations, demonstrating both stereochemically active and inactive behavior of the lone pair via charge and first-principle calculations. PMID:27560309

  9. Glass forming ability of soda lime borate Liquids

    OpenAIRE

    Zheng, Qiuju; Mauro, J. C.; Smedskjær, Morten Mattrup; Potuzak, M.; Keding, Ralf; Yue, Yuanzheng

    2010-01-01

    We investigate the composition dependence of glass-forming ability (GFA) of a series of iron-containing soda lime borate liquids by substituting Na2O for B2O3. We have characterized GFA by measuring the glass stability against crystallization using a differential scanning calorimeter (DSC). The results show that the GFA decreases when substituting Na2O for B2O3. Moreover, we find that there is no direct link between the kinetic fragility and GFA for the soda lime borate series studied herein....

  10. Effect of Magnesium Borates on the Fire-Retarding Properties of Zinc Borates

    Directory of Open Access Journals (Sweden)

    Azmi Seyhun Kipcak

    2014-01-01

    Full Text Available Magnesium borate (MB is a technical ceramic exhibiting high heat resistance, corrosion resistance, great mechanical strength, great insulation properties, lightweightness, high strength, and a high coefficient of elasticity. Zinc borate (ZB can be used as a multifunctional synergistic additive in addition to flame retardant additives in polymers. In this study, the raw materials of zinc oxide (ZnO, magnesium oxide (MgO, and boric acid (H3BO3 were used in the mole ratio of 1 : 1 : 9, which was obtained from preexperiments. Using the starting materials, hydrothermal synthesis was applied, and characterisation of the products was performed using X-Ray diffraction (XRD and Fourier transform infrared (FT-IR and Raman spectroscopies. The forms of Zn3B6O12·3.5H2O, MgO(B2O33·7(H2O, and Mg2(B6O7(OH62·9(H2O were synthesised successfully. Moreover, the surface morphology was investigated using scanning electron microscopy (SEM, and the B2O3 content was determined. In addition, the reaction yields were calculated. The results of the B2O3 content analysis were in compliance with the literature values. Examination of the SEM images indicated that the obtained nanoscale minerals had a reaction efficiency ranging between 63–74% for MB and 87–98% for ZB. Finally, the fire-retarding properties of the synthesised pure MBs, pure ZBs, and mixtures of MB and ZB were determined using differential thermal analysis and thermal gravimetry (DTA-TG and differential scanning calorimetry (DSC.

  11. DID WE IGNORE THE SOCIAL COMMENTARY? RESPONDING TO BORAT ON YOUTUBE

    OpenAIRE

    Mārtiņš Kaprāns

    2011-01-01

    Ever since the fictitious Kazakh journalist Borat Sagdiyev became an icon of contemporary popular culture, many questions have arisen about the reception of Borat by the general public. Namely, how have common people created a shared representation of Borat? And how is this complicated character and comedic manner undertaken by Sacha Baron Cohen being deciphered? These questions are crucial for understanding the challenges and constraints of social satire that exploits ethnically and stylisti...

  12. Synthesis and studies on microhardness of alkali zinc borate glasses

    International Nuclear Information System (INIS)

    The mixed alkali effect on zinc borate glasses have been reported. The glass systems of nominal composition 10Zn+xLi2O+yNa2O+80B2O3 (x = y = 0, 5, 10, 15 mol%) were prepared using standard melt quenching method. The structural, physical and mechanical properties of the samples have been studied using X-ray diffraction(XRD), density measurement and Vickers hardness measurement, respectively. A consistent increase in the density was observed, which explains the role of the modifiers (Li2O and Na2O) in the network modification of borate structure. The molar volume is decreasing linearly with the alkali concentration, which is attributed to the conversion of tetrahedral boron (BO4/2)− into (BO3/2)−. The microhardness studies reveals the anisotropy nature of the material. It further confirms that the samples belong to hard glass category

  13. Synthesis and studies on microhardness of alkali zinc borate glasses

    Science.gov (United States)

    Subhashini, Bhattacharya, Soumalya; Shashikala, H. D.; Udayashankar, N. K.

    2014-04-01

    The mixed alkali effect on zinc borate glasses have been reported. The glass systems of nominal composition 10Zn+xLi2O+yNa2O+80B2O3 (x = y = 0, 5, 10, 15 mol%) were prepared using standard melt quenching method. The structural, physical and mechanical properties of the samples have been studied using X-ray diffraction(XRD), density measurement and Vickers hardness measurement, respectively. A consistent increase in the density was observed, which explains the role of the modifiers (Li2O and Na2O) in the network modification of borate structure. The molar volume is decreasing linearly with the alkali concentration, which is attributed to the conversion of tetrahedral boron (BO4/2)- into (BO3/2)-. The microhardness studies reveals the anisotropy nature of the material. It further confirms that the samples belong to hard glass category.

  14. Could borate have played a role in the RNA World?

    Science.gov (United States)

    Grew, E. S.; Bada, J. L.; Hazen, R. M.

    2012-12-01

    Two scenarios have been proposed for boron to play a critical role in the stabilization of ribose and other sugars in the ribonucleic acid (RNA) World, >3.8 Ga ago. One scenario envisages oligomeric RNA being synthesized in subaerial intermountane desert valleys in which groundwater was enriched in borate from breakdown of tourmaline (Benner et al. 2012 doi: 10.1021/ar200332w). In the alternative scenario, borates are enriched in hydrothermal environments (3.8 Ma as they are today and (2) plate tectonics was the prevailing regime. The postulated non-marine borate deposits would have been associated with continental collision and subduction with volcanism releasing B, whereas in the second scenario, ocean floor caught up in an early phase of subduction is considered a favorable site for borate formation. Because borate deposits are typically ephemeral and poorly preserved, the lack of evidence in the geologic record for these scenarios does not invalidate them. For example, the oldest reported non-marine borate deposits analogous to the type postulated in first scenario are only 20 Ma, but metamorphosed borates of Precambrian age have been interpreted to have non-marine evaporite precursors, the oldest being 2.4-2.1 Ga in the Liaoning-Jilin area, China. The first B minerals so far reported in the geologic record are metamorphic dravite-schorl tourmalines in the 3.7-3.8 Ga Isua supracrustal belt (southern West Greenland), where there is good evidence for seafloor spreading and subduction. The precursors to the Isua tourmalines are reported to include B-bearing marine clay minerals and detrital tourmaline. The relatively high Li contents in zircon from Jack Hills, Australia, have been cited as evidence for the presence of granitic (s. l.) "protocontinental" crust by 4.3 Ga (Ushikuba et al. 2008 doi:10.1016/j.epsl.2008.05.032; Valley et al. 2010 Rec Geol Surv W Aust, 5-7), but the existence of conventional plate tectonics prior to 3.8 Ga remains controversial

  15. Coordination chemistry of poly(thioether)borate ligands

    OpenAIRE

    Riordan, Charles G.

    2010-01-01

    This review traces the development and application of the tris(thioether)borate ligands, tripodal ligands with highly polarizable thioether donors. Areas of emphasis include the basic coordination chemistry of the mid-to-late first row transition metals (Fe, Ni, Co, Cu), and the role of the thioether substituent in directing complex formation, the modeling of zinc thiolate protein active sites, high-spin organo-iron and organo-cobalt chemistry, the preparation of monovalent complexes of Fe, C...

  16. Potassium zinc borate, KZnB3O6

    Directory of Open Access Journals (Sweden)

    Yang Wu

    2010-05-01

    Full Text Available The title compound, KZnB3O6 contains a remarkable [B6O12]6− group (overline{1} symmetry formed by two rings linked by edge-sharing BO4 tetrahedra, a feature that has only been observed previously under high pressure conditions. These borate groups are connected through distorted ZnO4 tetrahedra in edge-shared pairs (overline{1} symmetry, forming a three-dimensional network whose cavities are filled by K+ cations.

  17. Potassium zinc borate, KZnB(3)O(6).

    Science.gov (United States)

    Wu, Yang; Yao, Ji-Yong; Zhang, Jian-Xiu; Fu, Pei-Zhen; Wu, Yi-Cheng

    2010-01-01

    The title compound, KZnB(3)O(6) contains a remarkable [B(6)O(12)](6-) group ( symmetry) formed by two rings linked by edge-sharing BO(4) tetra-hedra, a feature that has only been observed previously under high pressure conditions. These borate groups are connected through distorted ZnO(4) tetra-hedra in edge-shared pairs ( symmetry), forming a three-dimensional network whose cavities are filled by K(+) cations. PMID:21578991

  18. Glass-Forming Ability of Soda Lime Borate Liquids

    DEFF Research Database (Denmark)

    Zheng, Qiuju; Mauro, J.C.; Smedskjær, Morten Mattrup;

    2012-01-01

    ). The results show that the GFA decreases when substituting Na2O for B2O3. Moreover, we find that there is no direct link between the kinetic fragility and GFA for the soda lime borate series studied herein. We have also discovered and clarified a striking thermal history dependence of the glass stability...... by slowly cooling their melts to the glassy state, before any reheating. We explain this phenomenon in terms of the thermal history dependence of boron speciation....

  19. Infrared spectra of zinc doped lead borate glasses

    Indian Academy of Sciences (India)

    S G Motke; S P Yawale; S S Yawale

    2002-02-01

    The infrared spectra of zinc-doped lead borate glasses (10–30 mol% ZnO) were measured over a continuous spectral range (400–4000 cm–1) in an attempt to study their structure systematically. No boroxol ring formation was observed in the structure of these glasses. The formation of Zn in tetrahedral coordination was not observed. The conversion of three-fold to four-fold coordinated boron took place.

  20. DID WE IGNORE THE SOCIAL COMMENTARY? RESPONDING TO BORAT ON YOUTUBE

    Directory of Open Access Journals (Sweden)

    Mārtiņš Kaprāns

    2011-11-01

    Full Text Available Ever since the fictitious Kazakh journalist Borat Sagdiyev became an icon of contemporary popular culture, many questions have arisen about the reception of Borat by the general public. Namely, how have common people created a shared representation of Borat? And how is this complicated character and comedic manner undertaken by Sacha Baron Cohen being deciphered? These questions are crucial for understanding the challenges and constraints of social satire that exploits ethnically and stylistically sophisticated identity. To address these questions, which surely could be asked about other international media products as well, this article deals with the reception of Borat the character on YouTube. In particular, the viewers' reaction to the YouTube video titled "The Best of Borat" is analysed. This video has been viewed more than seven million times and commented on more than seven thousand times. The conceptual framework of this analysis is derived from the theory of social representations postulated by Serge Moscovici. In line with this theory two main dimensions - anchoring and objectification - are explored in order to understand how shared or divergent knowledge of Borat is created. Thus the basic socio-cognitive processes behind Borat are revealed. The results suggest that anchoring of Borat is embedded in national identification discourse, whereas objectification differentiates people according to their sense of humour. Likewise, some implications of Borat's reception for participatory culture and civic engagement are outlined.

  1. Production of fine zinc borate in industrial scale

    Directory of Open Access Journals (Sweden)

    Çakal Gaye Ö.

    2012-01-01

    Full Text Available In this study, zinc borate production in an industrial scale batch reactor was carried out at the optimum process conditions determined in the previous studies performed at the laboratory and pilot scale reactors. The production was done via the heterogeneous reaction of boric acid and zinc oxide. The samples were characterized by chemical analysis, XRD, TGA, SEM and particle size distribution. The final product which was obtained in the industrial scale reactor was 2ZnO.3B2O3.3H2O. The kinetic data for the zinc borate production reaction fit to a modified logistic model where the lag time was taken into account. As observed, the reaction time was influenced by scaling up. There was a lag time of 120 min for the industrial scale production and thus, the reaction completion time was 70 min longer compared to pilot scale. It should be emphasized that the specific reaction rate, k; as well as the average particle size and the hydration temperature of zinc borate are unaffected by scale up.

  2. Study on optical weak absorption of borate crystals

    Science.gov (United States)

    Li, Xiaomao; Hu, Zhanggui; Yue, Yinchao; Yu, Xuesong; Lin, Zheshuai; Zhang, Guochun

    2013-10-01

    Borate crystal is an important type of nonlinear optical crystals used in frequency conversion in all-solid-state lasers. Especially, LiB3O5 (LBO), CsB3O5 (CBO) and CsLiB6O10 (CLBO) are the most advanced. Although these borate crystals are all constructed by the same anionic group-(B3O7)5-, they show different nonlinear optical properties. In this study, bulk weak absorption values of three borate crystals have been studied at 1064 nm by a photothermal common-path interferometer. The bulk weak absorption values of them along [1 0 0], [0 1 0] and [0 0 1] directions were obtained, respectively, to be approximately 17.5 ppm cm-1, 15 ppm cm-1 and 20 ppm cm-1 (LBO); 80 ppm cm-1, 100 ppm cm-1 and 40 ppm cm-1 (CBO); 600 ppm cm-1, 600 ppm cm-1 and 150 ppm cm-1 (CLBO) at 1064 nm. The results showed an obvious discrepancy of the values of these crystals along three axis directions. A correlation between the bulk weak absorption property and crystal intrinsic structure was then discussed. It is found that the bulk weak absorption values strongly depend on the interstitial area surrounded by the B-O frames. The interstitial area is larger, the bulk weak absorption value is higher.

  3. Effects of ethanol on glycinergic synaptic currents in mouse spinal cord neurons

    Science.gov (United States)

    Mariqueo, Trinidad A.; Agurto, Adolfo; Muñoz, Braulio; San Martin, Loreto; Coronado, Cesar; Fernández-Pérez, Eduardo J.; Murath, Pablo; Sánchez, Andrea; Homanics, Gregg E.

    2014-01-01

    Ethanol increased the frequency of miniature glycinergic currents [miniature inhibitory postsynaptic currents (mIPSCs)] in cultured spinal neurons. This effect was dependent on intracellular calcium augmentation, since preincubation with BAPTA (an intracellular calcium chelator) or thapsigargin [a sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA) pump inhibitor] significantly attenuated this effect. Similarly, U73122 (a phospholipase C inhibitor) or 2-aminoethoxydiphenyl borate [2-APB, an inositol 1,4,5-trisphosphate (IP3) receptor (IP3R) inhibitor] reduced this effect. Block of ethanol action was also achieved after preincubation with Rp-cAMPS, inhibitor of the adenylate cyclase (AC)/PKA signaling pathway. These data suggest that there is a convergence at the level of IP3R that accounts for presynaptic ethanol effects. At the postsynaptic level, ethanol increased the decay time constant of mIPSCs in a group of neurons (30 ± 10% above control, n = 13/26 cells). On the other hand, the currents activated by exogenously applied glycine were consistently potentiated (55 ± 10% above control, n = 11/12 cells), which suggests that ethanol modulates synaptic and nonsynaptic glycine receptors (GlyRs) in a different fashion. Supporting the role of G protein modulation on ethanol responses, we found that a nonhydrolyzable GTP analog [guanosine 5′-O-(3-thiotriphosphate) (GTPγS)] increased the decay time constant in ∼50% of the neurons (28 ± 12%, n = 11/19 cells) but potentiated the glycine-activated Cl− current in most of the neurons examined (83 ± 29%, n = 7/9 cells). In addition, confocal microscopy showed that α1-containing GlyRs colocalized with Gβ and Piccolo (a presynaptic cytomatrix protein) in ∼40% of synaptic receptor clusters, suggesting that colocalization of Gβγ and GlyRs might account for the difference in ethanol sensitivity at the postsynaptic level. PMID:24572089

  4. Intracellular calcium release modulates polycystin-2 trafficking

    Directory of Open Access Journals (Sweden)

    Miyakawa Ayako

    2013-02-01

    Full Text Available Abstract Background Polycystin-2 (PC2, encoded by the gene that is mutated in autosomal dominant polycystic kidney disease (ADPKD, functions as a calcium (Ca2+ permeable ion channel. Considerable controversy remains regarding the subcellular localization and signaling function of PC2 in kidney cells. Methods We investigated the subcellular PC2 localization by immunocytochemistry and confocal microscopy in primary cultures of human and rat proximal tubule cells after stimulating cytosolic Ca2+ signaling. Plasma membrane (PM Ca2+ permeability was evaluated by Fura-2 manganese quenching using time-lapse fluorescence microscopy. Results We demonstrated that PC2 exhibits a dynamic subcellular localization pattern. In unstimulated human or rat proximal tubule cells, PC2 exhibited a cytosolic/reticular distribution. Treatments with agents that in various ways affect the Ca2+ signaling machinery, those being ATP, bradykinin, ionomycin, CPA or thapsigargin, resulted in increased PC2 immunostaining in the PM. Exposing cells to the steroid hormone ouabain, known to trigger Ca2+ oscillations in kidney cells, caused increased PC2 in the PM and increased PM Ca2+ permeability. Intracellular Ca2+ buffering with BAPTA, inositol 1,4,5-trisphosphate receptor (InsP3R inhibition with 2-aminoethoxydiphenyl borate (2-APB or Ca2+/Calmodulin-dependent kinase inhibition with KN-93 completely abolished ouabain-stimulated PC2 translocation to the PM. Conclusions These novel findings demonstrate intracellular Ca2+-dependent PC2 trafficking in human and rat kidney cells, which may provide new insight into cyst formations in ADPKD.

  5. Involvement of IP3-receptor activation in endothelin-1-induced Ca(2+) influx in rat pulmonary small artery.

    Science.gov (United States)

    Kato, K; Okamura, K; Hatta, M; Morita, H; Kajioka, S; Naito, S; Yamazaki, J

    2013-11-15

    We examined the endothelin-1 (ET-1)-induced increase in the intracellular free Ca(2+) concentration ([Ca(2+)]i) in fura-2-loaded rat pulmonary small arteries. ET-1 (30 nM) elicited a long-lasting increase in [Ca(2+)]i in physiological salt solution (PSS). In subsequent experiments, arteries were pretreated with BQ-788, an ETB-specific blocker, to allow us to focus on responses mediated via the ETA receptor, the existence of which was confirmed by immunohistochemistry. In Ca(2+)-free PSS, ET-1 evoked a small transient increase in [Ca(2+)]i, indicating Ca(2+) release from the SR (sarcoplasmic reticulum). After a switch to PSS (containing 2mM CaCl2), ET-1 elicited a long-lasting increase in [Ca(2+)]i that was not inhibited by 1 μM nicardipine, an L-type Ca(2+)-channel inhibitor, suggesting involvement of a Ca(2+)-influx pathway independent of that channel. In arteries preincubated with 30 μM cyclopiazonic acid (CPA) or 2 μM thapsigargin (TG), the ET-1-induced Ca(2+)-release was greatly reduced, and the induced Ca(2+)-influx was attenuated. U-73122, a phospholipase C (PLC) inhibitor, had inhibitory effects similar to those of CPA and TG on the ET-1-induced Ca(2+)-release and Ca(2+)-influx, whereas U-73343, an inactive analogue of U-73122, had no such effects. Two putative membrane-permeable IP3-receptor blockers, 2-aminoethoxydiphenyl borate (2APB, 50 μM) and Xestospongin C (20 μM), (a) almost completely inhibited the ET-1-induced Ca(2+)-release and Ca(2+)-influx, and (b) reduced the ET-1-induced contraction. These results indicate that in rat pulmonary small arteries, ET-1 induces receptor-operated Ca(2+) influx via the ETA receptor, and that this influx interacts with InsP3-receptor activation. PMID:24157978

  6. Conditioning highly concentrated borate solutions with calcium sulfo-aluminate cement

    International Nuclear Information System (INIS)

    The early age hydration by borate solution of 3 calcium sulfo-aluminate cements (CSA), containing respectively 0%, 10% and 20% of gypsum by weight of cement was studied using isothermal calorimetry and dynamic mode rheo-metry. XRD and TGA analysis were carried out on pastes with increasing hydration degrees (up to 90 days) to specify the mineralogy and to figure out the mechanisms of borate immobilisation. It has been shown that the retarding effect of borate anions is due to the precipitation of the amorphous calcium borate C2B3H8; borate anions were then incorporated in Aft-type phases. The macroscopic properties of hydrated binders (compressive strength, length change) were also followed during 180 days. It appears that the mechanical strength continuously increases with the hydration degree. Length changes under wet-curing and sealed bag remain moderate and seem to be stabilized after 180 days

  7. General and Localized Corrosion of Borated Stainless Steels

    Energy Technology Data Exchange (ETDEWEB)

    T.E. Lister; Ronald E. Mizia; A.W. Erickson; T.L. Trowbridge; B. S. Matteson

    2008-03-01

    The Transportation, Aging and Disposal (TAD) canister-based system is being proposed to transport and store spent nuclear fuel at the Monitored Geologic Repository (MGR) located at Yucca Mountain, Nevada. The preliminary design of this system identifies borated stainless steel as the neutron absorber material that will be used to fabricate fuel basket inserts for nuclear criticality control. This paper discusses corrosion test results for verifying the performance of this material manufactured to the requirements of ASTM A887, Grade A, under the expected repository conditions.

  8. Coordination chemistry of poly(thioether)borate ligands.

    Science.gov (United States)

    Riordan, Charles G

    2010-08-01

    This review traces the development and application of the tris(thioether)borate ligands, tripodal ligands with highly polarizable thioether donors. Areas of emphasis include the basic coordination chemistry of the mid-to-late first row transition metals (Fe, Ni, Co, Cu), and the role of the thioether substituent in directing complex formation, the modeling of zinc thiolate protein active sites, high-spin organo-iron and organo-cobalt chemistry, the preparation of monovalent complexes of Fe, Co and Ni, and dioxygen and sulfur activation by monovalent nickel complexes. PMID:20607091

  9. Production of zinc and copper borates in united process cycle

    International Nuclear Information System (INIS)

    Ecological technology permitting production of Zn3·B10O18·14H2O, 2ZnO·3B2O3·7H2O, 3CuO·2B2O3·nH2O·mNa2SO4 at a time in the single technological cycle was developed. Products was obtained during reaction of proper sulfates with borax in the presence of boric acid and sodium hydroxide. Mother liquor comprising saturated boric acid solution was used for the following preparation of zinc and copper borates

  10. Photoluminescence of a Te4+ center in zinc borate glass.

    Science.gov (United States)

    Masai, Hirokazu; Yamada, Yasuhiro; Okumura, Shun; Kanemitsu, Yoshihiko; Yoko, Toshinobu

    2013-10-01

    Photoluminescent (PL) properties related to Te(4+) species in zinc borate glasses are examined. Broad emission was observed by the excitation of the PL excitation peak of Te(4+) present at the optical absorption edge. The emission intensity of Te(4+) in 5TeO(2)-50ZnO-45B(2)O(3) glass was thermally quenched in a temperature region over 100 K, suggesting that concentration quenching preferentially occurred. The lifetime of the emission was approximately 2.5 μs, which is characteristic of relaxation from the triplet excitation state of an ns(2)-type center. PMID:24081051

  11. Photo- and thermostimulated luminescence of zinc borates, activated with manganese

    International Nuclear Information System (INIS)

    Zinc borates activated with Mn2+ have effective luminescence when exciting in the vacuum ultraviolet radiation range. It is connected with excitation energy absorption by anions. The luminescence spectra represent themselves wide bands with λmax = 540 nm for Zn4O5(BO2)6 - Mn2+ and ZnB4O7 - Mn2+, 595 nm for Zn3(BO3)2 - Mn2+. The zink orthoborate luminescence in the yellow-range of the spectra is connected with disordered tetrahedral environment of an activator

  12. Optical properties of Eu3+-doped zinc borate glasses

    International Nuclear Information System (INIS)

    Photoluminescence, absorption and optical excitation spectra of undoped and Eu3+-doped binary zinc borate glasses of varied composition prepared by the melt quenching technique in air atmosphere were investigated. From photoluminescence measurements it was found that growing Eu3+ concentration leads to gradual disappearance of the broadband glass emission in the near-UV spectral range, while the red Eu3+ emission at 613 nm shows a considerable increase. This result together with excitation spectra suggests that the Eu3+ ions are excited via energy transfer from the initially excited glassy host. The glass composition strongly affects the position of the excitation maximum in the UV energy range

  13. The Kerr nonlinearity of the beta-barium borate crystal

    DEFF Research Database (Denmark)

    Bache, Morten; Guo, Hairun; Zhou, Binbin;

    2013-01-01

    A popular crystal for ultrafast cascading experiments is beta-barium-borate (β-BaB2O4, BBO). It has a decent quadratic nonlinear coefficient, and because the crystal is anisotropie it can be birefringence phase-matched for type I (oo → e) second-harmonic generation (SHG). For femtosecond...... experiments BBO is popular because of low dispersion and a high damage threshold. The main attractive property of ultrafast cascading is that the induced cascading nonlinearity nI 2, casc can be negative, i.e. generate a self-defocusing Kerr-like nonlinearity. However, the material Kerr nonlinearity nI 2...

  14. Synthesis and characterization of cadmium doped lead–borate glasses

    Indian Academy of Sciences (India)

    A A Alemi; H Sedghi; A R Mirmohseni; V Golsanamlu

    2006-02-01

    Cadmium doped lead–borate glasses were prepared from the melts in appropriate proportions of PbO2, H3BO3 and (15–40 mol%) CdO mixture in the temperature range 700–950°C. The infrared spectra of the glasses in the range 400–4000 cm-1 show their structures. No boroxol ring formation was observed in the structure of these glasses. Furthermore, doped cadmium atoms were not seen in tetrahedral coordination. But the conversion of three-fold to four-fold coordination of boron atoms in the structure of glasses was observed.

  15. Synthesis, characterisation, electrical and optical properties of copper borate compounds

    Energy Technology Data Exchange (ETDEWEB)

    Kipcak, Azmi Seyhun; Senberber, Fatma Tugce [Department of Chemical Engineering, Faculty of Chemical and Metallurgical Engineering, Yildiz Technical University, Istanbul (Turkey); Aydin Yuksel, Sureyya [Department of Physics, Faculty of Arts and Science, Yildiz Technical University, Istanbul (Turkey); Derun, Emek Moroydor, E-mail: moroydor@gmail.com [Department of Chemical Engineering, Faculty of Chemical and Metallurgical Engineering, Yildiz Technical University, Istanbul (Turkey); Piskin, Sabriye [Department of Chemical Engineering, Faculty of Chemical and Metallurgical Engineering, Yildiz Technical University, Istanbul (Turkey)

    2015-10-15

    Highlights: • Cu(BO{sub 2}){sub 2} was synthesized at the form of with pdf number of “00-001-0472”. • Particle sizes were found between 162.72 and 56.44 nm and 195.76 and 75.73 nm at CuSNaH. • Reaction yields were 90.4 ± 0.84, 96.9 ± 0.78 and 78.9 ± 0.76% for CuST, CuSB and CuSNaH. • The resistivity of CuST, CuSB and CuSNaH are 1.10 × 10{sup 7}, 7.02 × 10{sup 6} and 8.62 × 10{sup 5} Ωm. • The optical energy gap was 3.76 eV. - Abstract: The hydrothermal synthesis of copper borate compounds [Cu(BO{sub 2}){sub 2}] was studied, and several parameters were found to affect the synthesis. Raw materials, including CuSO{sub 4}·5H{sub 2}O, Na{sub 2}B{sub 4}O{sub 7}·5H{sub 2}O, Na{sub 2}B{sub 4}O{sub 7}·10H{sub 2}O, NaOH and H{sub 3}BO{sub 3}, were used. Reaction temperatures and reaction times between 40 °C and 100 °C and 15 and 240 min, respectively, were used. The as-synthesised copper borate was analysed using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The yields of the reactions were also calculated. Single-phase, nanoparticulate copper borate compounds (Cu(BO{sub 2}){sub 2}) possessing high XRD crystal scores were obtained; the reactions used to obtain these materials were highly efficient. Electrical resistivity and optical absorbance measurements were carried out on the compounds obtained from the highest yielding reactions. The results of this study showed that even using a reaction time of 15 min, copper borate formation was successfully achieved.

  16. The Kerr nonlinearity of the beta-barium borate crystal

    OpenAIRE

    Bache, Morten; Guo, Hairun; Zhou, Binbin; Zeng, Xianglong

    2013-01-01

    A popular crystal for ultrafast cascading experiments is beta-barium-borate (β-BaB2O4, BBO). It has a decent quadratic nonlinear coefficient, and because the crystal is anisotropie it can be birefringence phase-matched for type I (oo → e) second-harmonic generation (SHG). For femtosecond experiments BBO is popular because of low dispersion and a high damage threshold. The main attractive property of ultrafast cascading is that the induced cascading nonlinearity nI 2, casc can be negative, i.e...

  17. Crystal chemistry and structure refinement of five hydrated calcium borates

    Science.gov (United States)

    Clark, J.R.; Appleman, D.E.; Christ, C.L.

    1964-01-01

    The crystal structures of the five known members of the series Ca2B6O11??xH2O (x = 1, 5, 5, 7, 9, and 13) have been refined by full-matrix least-squares techniques, yielding bond distances and angles with standard errors of less than 0??01 A?? and 0??5??, respectively. The results illustrate the crystal chemical principles that govern the structures of hydrated borate compounds. The importance of hydrogen bonding in the ferroelectric transition of colemanite is confirmed by more accurate proton assignments. ?? 1964.

  18. Third order nonlinear optical properties of bismuth zinc borate glasses

    International Nuclear Information System (INIS)

    Third order nonlinear optical characterization of bismuth zinc borate glasses are reported here using different laser pulse durations. Bismuth zinc borate glasses with compositions xBi2O3-30ZnO-(70-x) B2O3 (where x = 30, 35, 40, and 45 mol. %) have been prepared by melt quenching method. These glasses were characterized by Raman, UV-Vis absorption, and Z scan measurements. Raman and UV-Vis spectroscopic results indicate that non-bridging oxygens increase with increase of bismuth content in the glass. Nonlinear absorption and refraction behavior in the nanosecond (ns), picosecond (ps), and femtosecond (fs) time domains were studied in detail. Strong reverse saturable absorption due to dominant two-photon absorption (TPA) was observed with both ps and fs excitations. In the case of ns pulse excitations, TPA and free-carrier absorption processes contribute for the nonlinear absorption. Two-photon absorption coefficient (β) and the absorption cross section due to free carriers (σe) are estimated by theoretical fit of the open aperture Z-scan measurements and found to be dependent on the amount of bismuth oxide in the glass composition. In both ns and fs regimes the sign and magnitude of the third order nonlinearity are evaluated, and the optical limiting characteristics are also reported

  19. Third order nonlinear optical properties of bismuth zinc borate glasses

    Science.gov (United States)

    Shanmugavelu, B.; Ravi Kanth Kumar, V. V.; Kuladeep, R.; Narayana Rao, D.

    2013-12-01

    Third order nonlinear optical characterization of bismuth zinc borate glasses are reported here using different laser pulse durations. Bismuth zinc borate glasses with compositions xBi2O3-30ZnO-(70-x) B2O3 (where x = 30, 35, 40, and 45 mol. %) have been prepared by melt quenching method. These glasses were characterized by Raman, UV-Vis absorption, and Z scan measurements. Raman and UV-Vis spectroscopic results indicate that non-bridging oxygens increase with increase of bismuth content in the glass. Nonlinear absorption and refraction behavior in the nanosecond (ns), picosecond (ps), and femtosecond (fs) time domains were studied in detail. Strong reverse saturable absorption due to dominant two-photon absorption (TPA) was observed with both ps and fs excitations. In the case of ns pulse excitations, TPA and free-carrier absorption processes contribute for the nonlinear absorption. Two-photon absorption coefficient (β) and the absorption cross section due to free carriers (σe) are estimated by theoretical fit of the open aperture Z-scan measurements and found to be dependent on the amount of bismuth oxide in the glass composition. In both ns and fs regimes the sign and magnitude of the third order nonlinearity are evaluated, and the optical limiting characteristics are also reported.

  20. Synthesis and studies on microhardness of alkali zinc borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Subhashini,, E-mail: subhashini.p.p@gmail.com; Bhattacharya, Soumalya, E-mail: subhashini.p.p@gmail.com; Shashikala, H. D., E-mail: subhashini.p.p@gmail.com; Udayashankar, N. K., E-mail: subhashini.p.p@gmail.com [Department of Physics, National Institute of Technology Karnataka, Surathkal-575025 (India)

    2014-04-24

    The mixed alkali effect on zinc borate glasses have been reported. The glass systems of nominal composition 10Zn+xLi{sub 2}O+yNa{sub 2}O+80B{sub 2}O{sub 3} (x = y = 0, 5, 10, 15 mol%) were prepared using standard melt quenching method. The structural, physical and mechanical properties of the samples have been studied using X-ray diffraction(XRD), density measurement and Vickers hardness measurement, respectively. A consistent increase in the density was observed, which explains the role of the modifiers (Li{sub 2}O and Na{sub 2}O) in the network modification of borate structure. The molar volume is decreasing linearly with the alkali concentration, which is attributed to the conversion of tetrahedral boron (BO{sub 4/2}){sup −} into (BO{sub 3/2}){sup −}. The microhardness studies reveals the anisotropy nature of the material. It further confirms that the samples belong to hard glass category.

  1. Third order nonlinear optical properties of bismuth zinc borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Shanmugavelu, B.; Ravi Kanth Kumar, V. V., E-mail: ravi.phy@pondiuni.edu.in [Department of Physics, Pondicherry University, Puducherry 605 014 (India); Kuladeep, R.; Narayana Rao, D. [School of Physics, University of Hyderabad, Hyderabad 500046, Andhra Pradesh (India)

    2013-12-28

    Third order nonlinear optical characterization of bismuth zinc borate glasses are reported here using different laser pulse durations. Bismuth zinc borate glasses with compositions xBi{sub 2}O{sub 3}-30ZnO-(70-x) B{sub 2}O{sub 3} (where x = 30, 35, 40, and 45 mol. %) have been prepared by melt quenching method. These glasses were characterized by Raman, UV-Vis absorption, and Z scan measurements. Raman and UV-Vis spectroscopic results indicate that non-bridging oxygens increase with increase of bismuth content in the glass. Nonlinear absorption and refraction behavior in the nanosecond (ns), picosecond (ps), and femtosecond (fs) time domains were studied in detail. Strong reverse saturable absorption due to dominant two-photon absorption (TPA) was observed with both ps and fs excitations. In the case of ns pulse excitations, TPA and free-carrier absorption processes contribute for the nonlinear absorption. Two-photon absorption coefficient (β) and the absorption cross section due to free carriers (σ{sub e}) are estimated by theoretical fit of the open aperture Z-scan measurements and found to be dependent on the amount of bismuth oxide in the glass composition. In both ns and fs regimes the sign and magnitude of the third order nonlinearity are evaluated, and the optical limiting characteristics are also reported.

  2. Echinacea-induced cytosolic Ca2+ elevation in HEK293

    Directory of Open Access Journals (Sweden)

    Nikolau Basil J

    2010-11-01

    Full Text Available Abstract Background With a traditional medical use for treatment of various ailments, herbal preparations of Echinacea are now popularly used to improve immune responses. One likely mode of action is that alkamides from Echinacea bind to cannabinoid type 2 (CB2 receptors and induce a transient increase in intracellular Ca2+. Here, we show that unidentified compounds from Echinacea purpurea induce cytosolic Ca2+ elevation in non-immune-related cells, which lack CB2 receptors and that the Ca2+ elevation is not influenced by alkamides. Methods A non-immune human cell line, HEK293, was chosen to evaluate E. purpurea root extracts and constituents as potential regulators of intracellular Ca2+ levels. Changes in cytosolic Ca2+ levels were monitored and visualized by intracellular calcium imaging. U73122, a phospholipase C inhibitor, and 2-aminoethoxydiphenyl borate (2-APB, an antagonist of inositol-1,4,5-trisphosphate (IP3 receptor, were tested to determine the mechanism of this Ca2+ signaling pathway. E. purpurea root ethanol extracts were fractionated by preparative HPLC, screened for bioactivity on HEK293 cells and by GC-MS for potential constituent(s responsible for this bioactivity. Results A rapid transient increase in cytosolic Ca2+ levels occurs when E. purpurea extracts are applied to HEK293 cells. These stimulatory effects are phospholipase C and IP3 receptor dependent. Echinacea-evoked responses could not be blocked by SR 144528, a specific CB2 receptor antagonist, indicating that CB2 is not involved. Ca2+ elevation is sustained after the Echinacea-induced Ca2+ release from intracellular Ca2+ stores; this longer-term effect is abolished by 2-APB, indicating a possible store operated calcium entry involvement. Of 28 HPLC fractions from E. purpurea root extracts, six induce cytosolic Ca2+ increase. Interestingly, GC-MS analysis of these fractions, as well as treatment of HEK293 cells with known individual and combined chemicals, indicates the

  3. Optimization of the boration and dilution process due to power variations

    International Nuclear Information System (INIS)

    During power variations in a PWR reactor, Xenon and Samarium concentration changes occurs, carrying reactivity changes that must be compensated to keep constant the reactor criticality. That compensation is made by the addition of boron (Boration) or water (Dilution) into the core coolant. Both processes have significant costs, which is a motivation to make a power variation programming taking care to Boration and Dilution processes. In this work we present a method to optimize Boron utilization or borated water storage by choosing the best power reactor variation. (author)

  4. Transition and post-transition metal ions in borate glasses: Borate ligand speciation, cluster formation, and their effect on glass transition and mechanical properties

    Science.gov (United States)

    Möncke, D.; Kamitsos, E. I.; Palles, D.; Limbach, R.; Winterstein-Beckmann, A.; Honma, T.; Yao, Z.; Rouxel, T.; Wondraczek, L.

    2016-09-01

    A series of transition and post-transition metal ion (Mn, Cu, Zn, Pb, Bi) binary borate glasses was studied with special consideration of the cations impact on the borate structure, the cations cross-linking capacity, and more generally, structure-property correlations. Infrared (IR) and Raman spectroscopies were used for the structural characterization. These complementary techniques are sensitive to the short-range order as in the differentiation of tetrahedral and trigonal borate units or regarding the number of non-bridging oxygen ions per unit. Moreover, vibrational spectroscopy is also sensitive to the intermediate-range order and to the presence of superstructural units, such as rings and chains, or the combination of rings. In order to clarify band assignments for the various borate entities, examples are given from pure vitreous B2O3 to meta-, pyro-, ortho-, and even overmodified borate glass compositions. For binary metaborate glasses, the impact of the modifier cation on the borate speciation is shown. High field strength cations such as Zn2+ enhance the disproportionation of metaborate to polyborate and pyroborate units. Pb2+ and Bi3+ induce cluster formation, resulting in PbOn- and BiOn-pseudophases. Both lead and bismuth borate glasses show also a tendency to stabilize very large superstructural units in the form of diborate polyanions. Far-IR spectra reflect on the bonding states of modifier cations in glasses. The frequency of the measured cation-site vibration band was used to obtain the average force constant for the metal-oxygen bonding, FM-O. A linear correlation between glass transition temperature (Tg) and FM-O was shown for the metaborate glass series. The mechanical properties of the glasses also correlate with the force constant FM-O, though for cations of similar force constant the fraction of tetrahedral borate units (N4) strongly affects the thermal and mechanical properties. For paramagnetic Cu- and Mn-borate glasses, N4 was determined

  5. Structural investigation of Zn doped sodium bismuth borate glasses

    Science.gov (United States)

    Bhatia, V.; Kumar, D.; Singh, D.; Singh, S. P.

    2016-05-01

    A series of Bismuth Borate Oxide Glass samples with composition x(ZnO):(15-x)Na2O:15Bi2O3:70B2O3 (variation in x is from 6 to 12 mole %) have been prepared by conventional melt quenching technique. All the chemicals used were of Analytical Grade. In order to verify the amorphous nature of the prepared samples the X-Ray Diffraction (XRD) was done. The physical and structural properties have been explored by using the techniques such as density, molar volume and FTIR in order to understand the effect of alkali and transition metal ions on the structure of these glasses. The results obtained by these techniques are in good agreement to one another and with literature as well. With the increase in the content of ZnO, the increase in density and some variations in structural coordination (ratio of BO3 & BO4 structural units) have been observed.

  6. Elastic properties of Li+ doped lead zinc borate glasses

    Science.gov (United States)

    Rajaramakrishna, R.; Lakshmikantha, R.; Anavekar, R. V.

    2014-04-01

    Glasses in the system 0.25PbO-(0.25-x) ZnO-0.5B2O3-xLi2O have been prepared by the melt quenching technique. Elastic properties, DSC studies have been employed to study the role of Li2O in the present glass system. Elastic properties and Debye temperature have been determined using pulsed echo ultrasonic interferometer operating at 10MHz. Sound velocities Vl, Vt and elastic moduli decrease up to 5 mol% and then gradually increase with increase in Li2O concentration. Debye temperature and the glass transition temperature decreases with increase in Li2O. Densities remains almost constant up to 15 mol% Li2O concentration and increases monotonically while the molar volume decreases with the increase of Li2O concentration. The results are discussed in view of the borate structural network and dual role of Zn and Pb in these glasses.

  7. Thermal, structural and electrical studies of bismuth zinc borate glasses

    Science.gov (United States)

    Shanmugavelu, B.; Ravi Kanth Kumar, V. V.

    2013-06-01

    Bismuth Zinc Borate glasses with compositions xBi2O3-30ZnO-(70 - x)B2O3 (where x = 30, 35, 40 and 45 mol %) have been prepared by melt quenching method. These glasses were characterized by X-ray diffraction (XRD), Differential Thermal Analysis (DTA), Fourier Transform Infrared Spectrometer (FTIR) and Broad Band Dielectric Spectrometer (BDS). DTA and FTIR analysis reveals that Non-Bridging Oxygens (NBOs) increase with increase of bismuth content in the glass. Electrical data have been analyzed in the framework of impedance and modulus formalisms. The activation energy for dc conductivity decreases with increase of bismuth concentration. The imaginary part of modulus spectra has been fitted to non-exponential Kohlrausch-Williams-Watts (KWW) function and the value of the stretched exponent (β) is found to be almost independent of temperature but slightly dependent on composition.

  8. A facile electrodeposition of hydroxyapatite onto borate passivated surgical grade stainless steel

    International Nuclear Information System (INIS)

    Highlights: → Successful deposition of hydroxyapatite on 316L SS by a facile electrolytic Method. → Improvement of bio-resistivity of the alloy by increasing the time of borate Passivation. → Evolution of stable, bio-resistive hydroxyapatite coatings on borate passivated 316L SS. - Abstract: This paper reports a successful electrodeposition method for coating hydroxyapatite (HAP) onto surgical grade stainless steel (SS). Pure HAP coatings could be achieved at -1400 mV vs SCE and the coating resistivity was assessed by potentiodynamic polarization and impedance techniques which showed that HAP coatings deposited onto the borate passivated-SS specimens possess maximum bioresistivity in Ringer's solution. The coatings were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM) and Atomic force microscopy (AFM). The results have showed that the borate passivation followed by HAP coating performed on 316L SS could enhance the longevity of the alloy in Ringer's solution.

  9. Influence of sodium borate on the early age hydration of calcium sulfoaluminate cement

    Energy Technology Data Exchange (ETDEWEB)

    Champenois, Jean-Baptiste; Dhoury, Mélanie [CEA, DEN, DTCD, SPDE, F-30207 Bagnols-sur-Cèze Cedex (France); Cau Dit Coumes, Céline, E-mail: celine.cau-dit-coumes@cea.fr [CEA, DEN, DTCD, SPDE, F-30207 Bagnols-sur-Cèze Cedex (France); Mercier, Cyrille [LMCPA, Université de Valenciennes et du Hainaut Cambrésis, 59600 Maubeuge (France); Revel, Bertrand [Centre Commun de Mesure RMN, Université Lille1 Sciences Technologies, Cité Scientifique, 59655 Villeneuve d' Ascq Cedex (France); Le Bescop, Patrick [CEA, DEN, DPC, SECR, F-91192 Gif-sur-Yvette (France); Damidot, Denis [Ecole des Mines de Douai, LGCgE-GCE, 59508 Douai (France)

    2015-04-15

    Calcium sulfoaluminate (CSA) cements are potential candidates for the conditioning of radioactive wastes with high sodium borate concentrations. This work thus investigates early age hydration of two CSA cements with different gypsum contents (0 to 20%) as a function of the mixing solution composition (borate and NaOH concentrations). Gypsum plays a key role in controlling the reactivity of cement. When the mixing solution is pure water, increasing the gypsum concentration accelerates cement hydration. However, the reverse is observed when the mixing solution contains sodium borate. Until gypsum exhaustion, the pore solution pH remains constant at ~ 10.8, and a poorly crystallized borate compound (ulexite) precipitates. A correlation is established between this transient precipitation and the hydration delay. Decreasing the gypsum content in the binder, or increasing the sodium content in the mixing solution, are two ways of reducing the stability of ulexite, thus decreasing the hydration delay.

  10. Influence of sodium borate on the early age hydration of calcium sulfoaluminate cement

    International Nuclear Information System (INIS)

    Calcium sulfoaluminate (CSA) cements are potential candidates for the conditioning of radioactive wastes with high sodium borate concentrations. This work thus investigates early age hydration of two CSA cements with different gypsum contents (0 to 20%) as a function of the mixing solution composition (borate and NaOH concentrations). Gypsum plays a key role in controlling the reactivity of cement. When the mixing solution is pure water, increasing the gypsum concentration accelerates cement hydration. However, the reverse is observed when the mixing solution contains sodium borate. Until gypsum exhaustion, the pore solution pH remains constant at ~ 10.8, and a poorly crystallized borate compound (ulexite) precipitates. A correlation is established between this transient precipitation and the hydration delay. Decreasing the gypsum content in the binder, or increasing the sodium content in the mixing solution, are two ways of reducing the stability of ulexite, thus decreasing the hydration delay

  11. "Kasahhi ajakirjanik" Borat : tapvad kultuurierinevused on pööraselt naljakad / Margus Välja

    Index Scriptorium Estoniae

    Välja, Margus, 1958-

    2006-01-01

    Briti koomiku Sacha Baron Coheni loodud peategelasega USA film "Borat - kultuurialased õppetunnid Ameerikast abiks suursuguse Kasahstani riigi ülesehitamisel" : režissöör Larry Charles. Film jooksis ka Haapsalu kultuurikeskuses

  12. Interaction of lead-borate glass with aluminium and iron-nickel alloys

    International Nuclear Information System (INIS)

    Interaction of aluminium (AMG-6) and iron-nickel (47ND) alloys with lead-borate glass of PbO-73, BeO3-12, ZnO-10, Al2O3-3, SiO2-2 (mas. %) composition is investigated. It is determined that components of both soldered alloys interact actively with lead-borate glass melt that allows to obtain strong cohesion of glass with AMG-6 and 47ND metal alloys

  13. Process for the storage of borate containing radioactive wastes by vitrification

    International Nuclear Information System (INIS)

    For storage of radioactive waste by vitrification the radioactive waste concentrates from borate-containing liquids are mixed with glass-forming aggregates. The borates make up a major part of the glass product. A glass product with good chemical and physical properties for storage is produced by heating to produce a glass-forming melt. Lead oxides and silicates in particular are considered suitable aggregate materials. (orig.)

  14. Dosimetric properties of dysprosium doped lithium borate glass irradiated by 6 MV photons

    International Nuclear Information System (INIS)

    Undoped and dysprosium doped lithium borate glass system with empirical formula (70–x) B2O3–30 Li2O–(x) Dy2O3 (x=0.1, 0.3, 0.5, 0.7, 1.0 mol%) were prepared using the melt-quenching technique. The dosimetric measurements were performed by irradiating the samples to 6 MV photon beam using linear accelerator (LINAC) over a dose range of 0.5–5.0 Gy. The glass series of dysprosium doped lithium borate glass produced the best thermoluminescence (TL) glow curve with the highest intensity peak from sample with 1.0 mol% Dy2O3 concentration. Minimum detectable dose was detected at 2.24 mGy, good linearity of regression coefficient, high reproducibility and high sensitivity compared to the undoped glass are from 1.0 mol% dysprosium doped lithium borate glass. The results indicated that the series of dysprosium doped lithium glasses have a great potential to be considered as a thermoluminescence dosimetry (TLD). - Highlights: • TL response of undoped and dysprosium doped lithium borate glass subjected to 6 MV photons irradiation at low dose range. • TL linear response of dysprosium doped lithium borate glass. • The sensitivity of dysprosium doped lithium borate glass is approximately 93 times higher than undoped glass

  15. Synthesis and Characterization of Zinc Borate Nanowhiskers and Their Inflaming Retarding Effect in Polystyrene

    Directory of Open Access Journals (Sweden)

    Pingqiang Gao

    2015-01-01

    Full Text Available Zinc borate nanowhiskers 4ZnO·B2O3·H2O were in situ successfully synthesized via one-step precipitation reaction. A set of experiments was performed to evaluate the influence of reaction temperature. Increasing the temperature up to 70°C led to the high purity of zinc borate nanowhiskers with a monoclinic crystal structure measuring 50 nm to 100 nm in diameter and approximately 1 µm in length. However, higher temperature decreases the crystallization due to the emergence of other styles of zinc borate. Flame-resistant nanocomposites of polystyrene and zinc borate nanowhiskers were also successfully synthesized. The samples were investigated by XRD, FESEM, FTIR, and TG. The mechanical properties of the composites were also tested. The incorporation of zinc borate nanowhiskers improved the thermal and mechanical properties for polystyrene. FESEM images show that zinc borate nanowhiskers increased the smoothness of composites. The composites presented good responsive behavior in relation to LOI (limiting oxygen index allowing them to be suitable for green flame retardants.

  16. Spectrophotometric determination of boron in complex matrices by isothermal distillation of borate ester into curcumin

    International Nuclear Information System (INIS)

    In situ distillation of borate ester into the curcumin solution has been developed for the spectrophotometric determination of boron in a variety of complex matrixes. A polypropylene vessel containing the sample solution was placed inside a vessel (PP) containing 10 ml of curcumin solution and the distillation was carried out at room temperature/on a water bath. The borate ester collected in to the curcumin solution was evaporated to dryness on the water bath, taken in acetone and the absorbance was measured at 550 nm. In situ distillation of borate ester directly into the chromogenic reagent eliminates tedious sample treatment (before and/or after borate separation), use of methanol, complicated quartz set up, possible loss of boron and reduces the analysis time significantly. In situ dehydration of sample solution by ethanolic vapour in the absence of dehydrating acid prevents the formation of fluoborate and co-distillation of potential anionic interferents (nitrate and fluoride). This developed method has been applied for the determination of traces of boric acid in boron powder by the distillation of methyl borate at room temperature. For other matrixes (water, uranium oxide, uranyl nitrate, fluoride salt, etc.) distillation of ethyl borate was carried out on the water bath. LOD (3σ) was 5 ng g-1 for water and 30 ng g-1 for solid samples

  17. Ion-conductivity of thin film Li-Borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Abouzari, M.R.S.

    2007-12-17

    In this thesis, the specific conductivity of ion-sputtered lithium borate thin films is studied. To this end, lithium borate glasses of the composition yLi{sub 2}O.(1-y)B{sub 2}O{sub 3} with y=0.15, 0.20, 0.25, and 0.35 were produced as sputter targets. Films with thicknesses between 7 nm and 700 nm are deposited on silicon substrate between two AlLi electrodes. Conductivity spectra have been taken over a frequency range of 5 Hz to 2 MHz. The measurements were performed at different temperatures between 40 C and 350 C depending on the thickness and the composition of the films. The following results are derived by studying the conductivities of the films: i) The specific dc conductivity of layers with thicknesses larger than 150 nm is independent of their thicknesses; we call these layers 'thick films' and consider their conductivity as the 'base conductivity'. ii) The specific dc conductivity of layers with thicknesses smaller than 150 nm, called 'thin films', depends on the layer thickness. A nontrivial enhancement of the specific dc conductivity about three orders of magnitude for y=0.15, 0.2, and 0.25 is observed. iii) The base conductivity depends on y and at 120 C it varies between 4 x 10{sup -10} {omega}{sup -1}cm{sup -1} and 2.5 x 10{sup -6} {omega}{sup -1}cm{sup -1} when y varies between 0.15 and 0.35, whereas the maximum value of the specific dc conductivity of extremely thin films (with a thickness of some nanometre) seems to be independent of y and equals to the specific dc conductivity of layers with y= 0.35. Furthermore, we found in this work a physical interpretation of the so-called 'Constant Phase Element' (CPE) which is widely used in equivalent circuits for ionic conductors. This element describes correctly the depressed impedance semicircles observed in impedance spectroscopy. So far, this effect is sometimes attributed to the surface roughness. We have shown not only the invalidity of this approach, but

  18. Spectroscopic properties of the Ce-doped borate glasses

    Science.gov (United States)

    Kindrat, I. I.; Padlyak, B. V.; Mahlik, S.; Kukliński, B.; Kulyk, Y. O.

    2016-09-01

    The EPR, optical absorption and photoluminescence (emission and excitation) spectra as well as decay kinetics of a series of the Ce-doped glasses with Li2B4O7, LiKB4O7, CaB4O7, and LiCaBO3 compositions have been investigated and analysed. The borate glasses were obtained from the corresponding polycrystalline compounds in the air atmosphere, using standard glass technology. The EPR signals of the isolated Ce3+ and pair Ce3+-Ce3+ centres, coupled by magnetic dipolar and exchange interactions were registered at liquid helium temperatures. The characteristic for glass host broad bands corresponding to the 4f → 5d transitions of the Ce3+centres have been observed in the optical absorption and photoluminescence (emission and excitation) spectra. The obtained luminescence decay curves can be satisfactory described by exponential function with lifetimes in the 19.8-26.1 ns range, which depend on the basic glass composition. The local structure of Ce3+ centres in the investigated glasses has been considered and discussed.

  19. Researches on the electrolysis of metal oxides dissolved in boric anhydride or in melt borates. New methods of preparation of amorphous boron, borides and some metals

    International Nuclear Information System (INIS)

    This research thesis reports the investigation of the electrolysis of alkaline borates, alkaline earth borates and magnesium borate, and the investigation of mixtures containing a metal oxide dissolved in a bath formed by a tetraborate and a fluoride. The author more particularly studies the chemical products separated at the cathode level, i.e. boron (more or less pure), borates and other metals (zinc, tungsten, molybdenum)

  20. Syrthesis and properties of nickel borate acylate as a new rubber-steel cord adhesion promoter

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The synthetic method of nickel borate acylate (NBA), a kind of rubber-steel cord adhesion promoter (AP), through nickel carbonate, borate and mixed carboxylic acid was studied. The preparation of nickel carbonate could be performed through reaction of nickel sulfate with sodium carbonate in aqueous solution,in which fractional conversion of nickel was more than 99.9%. The mixed nickel carboxylate was prepared by the reaction of nicke carbonate with isooctanoic acid and acetic acid, under strong stirring for 2 h, the mole ratio of these chemicals were 1: 1: 1.1 respectively, and water should be removed completely by adding of inert organic solvent after reaction was finished so as to avoid hydrolysis of tributyl borate in the second reaction.NBA was synthesizec by reaction of mixed nickel carboxylate with tributyl borate under strong stirring at 200-250 ℃ for 6 h. By detection and comparison with 680C product from Manobond Company of England, the NBA synthesized through isooctanoic acid and tributyl borate was very similar to product 680C in IR data,300% fixed extension strength, tensile strength, hardness and cure curve, and was slightly lower than those ofproduct 680C in tensile failure extensibility and hot air aging. The experimental results show that the preparedNBA can be used as robber-steel cord AP.

  1. Effect of modifying agents on the hydrophobicity and yield of zinc borate synthesized by zinc oxide

    Science.gov (United States)

    Acarali, Nil Baran; Bardakci, Melek; Tugrul, Nurcan; Derun, Emek Moroydor; Piskin, Sabriye

    2013-06-01

    The aim of this study was to synthesize zinc borate using zinc oxide, reference boric acid, and reference zinc borate (reference ZB) as the seed, and to investigate the effects of modifying agents and reaction parameters on the hydrophobicity and yield, respectively. The reaction parameters include reaction time (1-5 h), reactant ratio (H3BO3/ZnO by mass: 2-5), seed ratio (seed crystal/(H3BO3+ZnO) by mass: 0-2wt%), reaction temperature (50-120°C), cooling temperature (10-80°C), and stirring rate (400-700 r/min); the modifying agents involve propylene glycol (PG, 0-6wt%), kerosene (1wt%-6wt%), and oleic acid (OA, 1wt%-6wt%) with solvents (isopropyl alcohol (IPA), ethanol, and methanol). The results of reaction yield obtained from either magnetically or mechanically stirred systems were compared. Zinc borate produced was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and contact angle tests to identify the hydrophobicity. In conclusion, zinc borate is synthesized successfully under the optimized reaction conditions, and the different modifying agents with various solvents affect the hydrophobicity of zinc borate.

  2. Synthesis of hydrophobic zinc borate nanoflakes and its effect on flame retardant properties of polyethylene

    International Nuclear Information System (INIS)

    Zinc borate (2ZnO.3B2O3.3.5H2O) has relatively high dehydration on-set temperature which property permits processing in a wide range of polymer system. But zinc borate particles are hardly dispersed in a polymer matrix so that they prevent their using in industry. To address this problem, we synthesized hydrophobic zinc borate (2ZnO.3B2O3.3.5H2O) nanoflakes by employing solid-liquid reaction of zinc oxide (ZnO) and boric acid (H3BO3) in the presence of oleic acid. This method does not bring pollution. By conducting morphological and microscopic analyses, we found that this compound displayed nanoflake morphology with particle size of around 100-200 nm, thickness less than 100 nm and there were uniform mesopores with the diameter about 10 nm within the particles. Furthermore, our products had an effect on flame retardant of polyethylene, especially when the zinc borate was modified by oleic acid. - Graphical abstract: The contact angle of hydrophobic zinc borate nanoflakes is 129.02 deg. with added 2.0 wt% of oleic acid.

  3. 77 FR 74883 - Aging Management of Stainless Steel Structures and Components in Treated Borated Water; Revision 1

    Science.gov (United States)

    2012-12-18

    ... Treated Borated Water,'' in the Federal Register on May 11, 2012 (77 FR 27815). As issued, LR-ISG-2011-01... COMMISSION Aging Management of Stainless Steel Structures and Components in Treated Borated Water; Revision 1..., 2012 (77 FR 27815). Revision 1 of this document corrects the identification numbers for...

  4. Complexation Between Borate ion and Hydroxyl Groups of Phenol-Formaldehyde Resol Resin

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The complexation reaction between borate ions and phenol-formaldehyde resol resin in aqueous solution was studied by pH measurement, small model molecules and infrared spectroscopy.The results show that the complexation can proceed completely and rapidly at room temperature.Borate ion attacks phenol hydroxyl groups and adjacent position hydroxymethyl groups on the phenol ring of the resin, and forms the coordinate bond between boron atom in borate ion and oxygen atom in the hydroxyl groups. The complexation is a quantitative reaction. The complex is a six member ring containing two oxygens and one boron. The complexation can release hydrogen ions resulting in the decreasing pH in the resin solution.

  5. Vibrational spectroscopy of the borate mineral kotoite Mg₃(BO₃)₂.

    Science.gov (United States)

    Frost, Ray L; Xi, Yunfei

    2013-02-15

    Vibrational spectroscopy has been used to assess the structure of kotoite a borate mineral of magnesium which is isostructural with jimboite. The mineral is orthorhombic with point group: 2/m 2/m 2/m. The mineral has the potential as a new memory insulator material. The mineral has been characterised by a combination of Raman and infrared spectroscopy. The Raman spectrum is dominated by a very intense band at 835 cm(-1), assigned to the symmetric stretching mode of tetrahedral boron. Raman bands at 919, 985 and 1015 cm(-1) are attributed to the antisymmetric stretching modes of tetrahedral boron. Kotoite is strictly an hydrous borate mineral. An intense Raman band observed at 3559 cm(-1) is attributed to the stretching vibration of hydroxyl units, more likely to be associated with the borate mineral hydroxyborate. The lack of observation of water bending modes proves the absence of water in the kotoite structure. PMID:23257343

  6. Rheological Properties of Konjac Glucomannan/SiO_2 /Organic-Borate Gels

    Institute of Scientific and Technical Information of China (English)

    WU Lili; ZHANG Chaocan; GUO Jinming; GAO Shanjun

    2009-01-01

    A series of thermoreversible konjac glucomannan gels crosslinked by organic bo-rate were prepared.Required amount of hydrophilic SiO_2 was added into the konjac glucomannan solutions before the crosslinking reaction.The gel network was formed through the crosslinking reac-tion between borate ions dissociated from organic borate and the cis-diol hydroxyl groups on the mannose units of polysaccharide chains.The rheological properties of the complex gels were studied by dynamic viscoelastic measurement.The gelation kinetics of the complex gels was studied and the critical gelation points of the gels were exactly determined by the Winter-Chambon criterion.The ef-fects of temperature and composite ratio on the shear storage modulus(G'),the loss modulus(G") and the sol-gel transition points were investigated.

  7. Luminescence properties of the Sm-doped borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Kindrat, I.I. [University of Zielona Góra, Institute of Physics, Division of Spectroscopy of Functional Materials, 4a Szafrana Street, 65-516 Zielona Góra (Poland); Padlyak, B.V., E-mail: B.Padlyak@if.uz.zgora.pl [University of Zielona Góra, Institute of Physics, Division of Spectroscopy of Functional Materials, 4a Szafrana Street, 65-516 Zielona Góra (Poland); Vlokh Institute of Physical Optics, 23 Dragomanov Street, 79-005 Lviv (Ukraine); Drzewiecki, A. [University of Zielona Góra, Institute of Physics, Division of Spectroscopy of Functional Materials, 4a Szafrana Street, 65-516 Zielona Góra (Poland)

    2015-10-15

    The optical absorption and photoluminescence (emission and excitation) spectra as well as decay kinetics of a series of the Sm-doped glasses with Li{sub 2}B{sub 4}O{sub 7}, LiKB{sub 4}O{sub 7}, CaB{sub 4}O{sub 7}, and LiCaBO{sub 3} compositions were investigated and analysed. The Li{sub 2}B{sub 4}O{sub 7}:Sm, LiKB{sub 4}O{sub 7}:Sm, CaB{sub 4}O{sub 7}:Sm, and LiCaBO{sub 3}:Sm glasses of high optical quality have been obtained from the corresponding polycrystalline compounds in the air atmosphere, using a standard glass technology. On the basis of electron paramagnetic resonance (EPR) and optical spectra analysis it was shown that the samarium impurity is incorporated into the glass network as Sm{sup 3+} (4f{sup 5}, {sup 6}H{sub 5/2}) ions, exclusively. All observed 4f – 4f transitions of the Sm{sup 3+} centres in the optical absorption and luminescence spectra of the investigated glasses are identified. Most intense emission band of the Sm{sup 3+} ions peaked about 598 nm ({sup 4}G{sub 5/2} → {sup 6}H{sub 7/2} transition) is characterised by a single exponential decay with typical lifetime values, which depend on the basic glass composition as well as concentration and local structure of the Sm{sup 3+} luminescence centres. The quantum efficiency has been evaluated for observed transitions of the Sm{sup 3+} centres using obtained experimental lifetimes and radiative lifetimes calculated by Judd–Ofelt theory. The calculated high quantum efficiencies and measured quantum yields of luminescence show that the investigated borate glasses are perspective luminescence materials. Energy transfer from the Ce{sup 3+} non-controlled impurity and intrinsic luminescence centres to the Sm{sup 3+} centres has been observed. Peculiarities of the Sm{sup 3+} local structure in the network of investigated glasses have been discussed based on the obtained spectroscopic results and structural data. - Highlights: • The Sm-doped Li{sub 2}B{sub 4}O{sub 7}, LiKB{sub 4}O{sub 7}, Ca

  8. Mass and Energy Balances for Black Liquor Gasification with Borate Autocausticization

    Energy Technology Data Exchange (ETDEWEB)

    Arosenius, Anna-Karin

    2007-01-15

    Gasification of black liquor is considered to be a promising alternative technique for recovery of black liquor in kraft pulping. Compared to the conventional recovery process, i.e. combustion of black liquor in a recovery boiler, the primary advantage of gasification is the potential to produce biofuels and chemicals. The causticizing demand is though higher for the gasification technology. If the existing lime kiln can not handle the extra load, partial borate autocausticizing may be an alternative. In this work, the energy balance for a kraft pulp mill using black liquor gasification and partial borate autocausticization is compared with a mill using gasification and extended lime causticizing and also with a mill having a conventional recovery cycle. Additionally, the chemical costs for the partial borate autocausticizing is compared to the investment cost of the larger lime kiln. Mass and energy balances are based on the updated reference mill in the MISTRA Research Program, 'The Eco-Cyclic Pulp Mill', producing 2000 ADt of pulp per day. The results show that less energy is released to steam production in a gasifier than in a recovery boiler and instead energy is released in chemical form in the produced syn gas. Using partial borate autocausticizing, the demand of external energy is lowered in the lime kiln compared to extended lime causticization. The borate autocausticization, taking place in the gasifier with black liquor as energy source, only demands a third of the energy saved in the lime kiln. On the other hand the chemical costs for the borate autocausticization exceeds the investment cost for a larger lime kiln after five years.

  9. AFM studies of swift heavy ion and electron irradiated mixed barium strontium borate nonlinear optical crystal

    International Nuclear Information System (INIS)

    Single crystals of novel nonlinear optical material of mixed barium strontium borate is grown in our laboratory by employing the low-temperature solution technique. Equal proportion (1:1 molar ratio) of AR grade barium borate and strontium borate are mixed together in double distilled water to prepare a supersaturated solution. The solution is allowed to evaporate at constant temperature (30 deg. C) in a Petri dish for about a week which resulted in the formation of seed crystals. These seed crystals are used to grow larger crystals by suspending them using fine silk thread in the supersaturated mother solution. The solution is allowed to evaporate at constant temperature. This resulted in the growth of good transparent crystals of dimension 15 mmx10 mmx1 mm after about one month. These crystals show good second harmonic generation (SHG) efficiency. The mixed barium strontium borate crystal is found to be a promising nonlinear optical crystal, which possibly can be used for fabrication of photonic devices. The single crystals of mixed barium strontium borate are irradiated by 120 MeV Ag+13 swift heavy ions (SHI) of fluence 5x1011 ions/cm2 at Nuclear Science Centre, New Delhi and also by electrons of 8 MeV energy with a fluence 5.7x109/cm2 using Microtron accelerator at Mangalore University. Surface morphology studies of these crystals are carried out using atomic force microscope. The AFM topographical images of these SHI/electron irradiated single crystals of mixed barium strontium borate are obtained from different frames of the sample taken at different magnifications using atomic force microscope. An attempt is made to explain the surface damage caused due to SHI/electron irradiation using the observed AFM images

  10. Chemical and boron isotopic compositions of tourmaline from the Paleoproterozoic Houxianyu borate deposit, NE China: Implications for the origin of borate deposit

    Science.gov (United States)

    Yan, Xue-long; Chen, Bin

    2014-11-01

    The Houxianyu borate deposit in northeastern China is one of the largest boron sources of China, hosted mainly in the Paleoproterozoic meta-volcanic and sedimentary rocks (known as the Liaohe Group) that are characterized by high boron concentrations. The borate ore-body has intimate spatial relationship with the Mg-rich carbonates/silicates of the Group, with fine-grained gneisses (meta-felsic volcanic rocks) as main country rocks. The presence of abundant tourmalinites and tourmaline-rich quartz veins in the borate orebody provides an opportunity to study the origin of boron, the nature of ore-forming fluids, and possible mineralization mechanism. We report the chemical and boron isotopic compositions of tourmalines from the tourmaline-rich rocks in the borate deposit and from the tourmaline-bearing fine-grained gneisses. Tourmalines from the fine-grained gneisses are chemically homogeneous, showing relatively high Fe and Na and low Mg, with δ11B values in a narrow range from +1.22‰ to +2.63‰. Tourmalines from the tourmaline-rich rocks, however, commonly show compositional zoning, with an irregular detrital core and a euhedral overgrowth, and have significantly higher Mg, REE (and more pronounced positive Eu anomalies), V (229-1852 ppm) and Sr (208-1191 ppm) than those from the fine-grained gneisses. They show varied B isotope values ranging from +4.51‰ to +12.43‰, which plot intermediate between those of the terrigenous sediments and arc rocks with low boron isotope values (as represented by the δ11B = +1.22‰ to +2.63‰ of the fine-grained gneisses of this study) and those of marine carbonates and evaporates with high boron isotope values. In addition, the rim of the zoned tourmaline shows notably higher Mg, Ti, V, Sn, and Pb, and REE (particularly LREEs), but lower Fe, Co, Cr, Ni, Zn, Mn, and lower δ11B values than the core. These data suggest that (1) the sources of boron of the borate ore-body are mainly the Paleoproterozoic meta-volcanic and

  11. Study of the microstructural transformations of borate glass and barium metaborate crystals induced by femtosecond laser

    Institute of Scientific and Technical Information of China (English)

    Chen Bin; Yu Bing-Kun; Yan Xiao-Na; Qiu Jian-Rong; Jiang Xiong-Wei; Zhu Cong-Shan

    2004-01-01

    This paper describes the microstructural transformations of borate glass and barium metaborate crystals induced by femtosecond laser. Such structural transformations were verified by Raman spectroscopy. The borate glass is transformed into low temperature (LT) phase of barium metaborate (BaB2O4) crystals after being irradiated for 10 min by a femtosecond laser. In addition, after 20 min of irradiation, high temperature (HT) phase of BaB2O4 crystals is also produced. Further studies demonstrate that LT phase BaB2O4 crystals are formed in the HT phase BaB2O4 crystals after femtosecond laser irradiation for 10 s.

  12. Moessbauer spectroscopic study of the thermal neutron irradiated potassium borate glasses

    International Nuclear Information System (INIS)

    Moessbauer study was performed for thermal neutron irradiated potassium borate glasses containing 7 mol % of ferric oxide. The alkali contents of the glasses were changed from 10 to 40 mol %. The decrease of isomer shift was observed by the irradiation of the glasses when the alkali content was higher than 20 mol %. The increase of the quadrupole splitting was also observed in the low alkali content region. These results were discussed in connection with the nuclear reaction of 10B(n,α)7Li and the network structure of the borate glasses. (author)

  13. Luminescence properties of manganese doped zinc-borates with different structure

    International Nuclear Information System (INIS)

    A study was made on spectral-luminescent characteristics of zinc-borates with different structure, activated by Mn2+ ions, as well as on prospects of their practical use in gas-discharge indication panels (GIP). Spectral characteristics of zinc metaborate Zn4O(BO2)6 and zinc orthoborate Zn3(BO3)2 under VUV-excitation were investigated. The presented spectral-luminescent characteristics of zinc-borates, activated by Mn2 ions, testify to the promising character of their use in GIP

  14. EVALUATION OF BORATED ALUMINUM PRODUCTS FOR CRITICALITY CONTROL IN 235-F

    Energy Technology Data Exchange (ETDEWEB)

    Duncan, A.; Sindelar, R.

    2003-05-06

    Plutonium-containing materials are destined for storage in the 235-F vault. The projected amount of stored materials will require the presence of neutron absorber materials. The leading design concept is for the neutron absorber materials to be in non-load-bearing borated aluminum plates lining the walls of the vault. A comprehensive evaluation of the borated aluminum plate materials was performed to identify a suitable material, and verify that these materials would remain effective as neutron absorbers under normal service conditions and for design-basis events, including the fire accident scenario, throughout a 20-year service life. Aluminum 1100 with boron additions is the recommended neutron absorber material for plutonium material storage in the 235-F vault based on boron loading capacity and durability in the storage environment. Borated aluminum 1100 is commercially available up to 4.5 wt. % boron. A detailed comparison was made of the physical, mechanical, and corrosion properties of borated aluminum alloy 1100 to standard alloy 1100-O (-O designating the fully annealed condition) to demonstrate near-equivalency in properties and to justify application of alloy 1100-O properties to the borated product as needed for the degradation analysis. The expected degradation of the borated aluminum is extremely low for storage conditions, including the bounding scenario of an aggressive atmospheric condition. A maximum loss of 0.00029 inches/year would be expected under potentially aggressive atmospheric conditions and would result in a fractional loss of only 0.42 wt. % of the boron present in a 7mm plate for a 20-year storage period. The fraction of Boron-10 consumption by spontaneous neutrons is expected to be less than 10{sup -8} for the 20-year storage in 235-F fully loaded with Pu materials. The borated aluminum alloy 1100 will be thermally stable and unaltered up to near-melt temperature (643°C). Mechanical testing data at elevated temperatures show that the

  15. Bone bonding ability of some borate bio-glasses and their corresponding glass-ceramic derivatives

    OpenAIRE

    Fatma H. Margha; Amr M. Abdelghany

    2012-01-01

    Ternary borate glasses from the system Na2O·CaO·B2O3 together with soda-lime-borate samples containing 5 wt.% of MgO, Al2O3, SiO2 or P2O5 were prepared. The obtained glasses were converted to their glass-ceramic derivatives by controlled heat treatment. X-ray diffraction was employed to investigate the separated crystalline phases in glass-ceramics after heat treatment of the glassy samples. The glasses and corresponding glass-ceramics after immersion in water or diluted phosphate solution f...

  16. Geochemical characteristics of Kırka (Sarıkaya) borate deposit, northwestern Anatolia, Turkey

    Indian Academy of Sciences (India)

    İ Koçak; Ş Koç

    2016-02-01

    The Kırka borate deposit was deposited in a Miocene lacustrine basin which is closely associated with volcanic activity which lasted from Paleogene to the beginning of Quaternary. Borate mineralization alternates with claystone, mudstone, tuff and fine-layered limestone and mostly shows a lenticular structure. The mineral paragenesis is composed of borax, tincalconite, ulexite, kurnakovite, probertite, tunellite, colemanite, dolomite, smectite group minerals, illite and some firstly reported minerals for the Kırka deposit including hydrochloroborite, brianroulstonite, hilgardite-4M and searlesite minerals. In comparison to average values of earth crust, concentrations of Cs, Sr, Li, As and Se were significantly enriched with respective rates of 21, 15, 14, 3 and 188 folds. Regarding KY, KS1 and KS2 locations, there are differences in both element abundances and their geochemical tendencies which are attributed to variations in discharge regime and physico-chemical conditions of the depositional environment. Independent behaviour of B2O3 might indicate that boron is not associated with clays and carbonates and, therefore, most part of boron must be derived from volcanic activity (hydrothermal solutions, gases). REE data indicate that the Kırka borate deposit was formed in a sedimentary environment where highly alkaline (high pH) hydrothermal solutions also took part in borate precipitation process.

  17. Low-energy collisionally activated dissociation of pentose-borate complexes

    Science.gov (United States)

    Pepi, Federico; Garzoli, Stefania; Tata, Alessandra; Giacomello, Pierluigi

    2010-01-01

    Pentose-borate 1:1 complexes were generated in the ESI source of a triple quadrupole and ion trap mass spectrometer by electrospray ionization of Na2B4O7 and pentose (arabinose, lyxose, ribose, xylose) 2:1 solution in CH3CN/H2O. The study of their low-energy collisionally activated dissociation (CAD) demonstrated that ribose and lyxose are preferentially complexed at the C2-C3 cis-diol function whereas arabinose and xylose are esterified at the C1-C2 hydroxyl groups. No evidence was found of the stronger affinity for ribose to borate. The ribose probiotic rule can be explained by considering its peculiar capability, among the investigated pentoses, to almost totally complex the borate anion at the C2-C3 hydroxyl group, thus enabling the subsequent stages of nucleotide assembly, such as phosphorylation and linkage to the nucleobases. Finally, the differences observed in the pentose-borate complex CAD spectra can be used for the mass spectrometric discrimination of isomeric pentoses in complex mixtures.

  18. Synthesis and properties of rubber-steel cord adhesion promoter nickel borate acylate

    Institute of Scientific and Technical Information of China (English)

    李晓如; 吴海鹰; 成本诚

    2002-01-01

    The synthesis of nickel borate acylate (NBA), a kind of rubber-steel cord adhesion promoter (AP), through nickel carbonate, borate and mixed carboxylic acid was studied. Nickel carbonate could be prepared by the reaction of nickel sulfate with sodium carbonate in aqueous solution. After strong stirring for 2h, the mixed nickel carboxylate could be synthesized by the reaction of nickel carbonate with isooctanoic acid and acetic acid. The mole ratio of these chemicals was 1∶1∶1.1. NBA was synthesized by reaction of mixed nickel carboxylate with tributyl borate under strong stirring at 200~250℃ for 6h. By detecting and comparing with 680C product from Manobond Company of England, the NBA synthesized through isooctanoic acid and tributyl borate is very similar with 680C in IR data, 300% fixed extension strength, tensile strength, hardness and cure curve. However, tensile failure extensibility and hot air aging of NBA are a little lower than those of 680C. The experimental results show that NBA can be used as rubber-steel cord AP.

  19. Modification of the sanitary ware body by fluxes containing zinc borate

    International Nuclear Information System (INIS)

    The influence of fluxes containing zinc borate on the sintering process and on the resulting sanitary ware properties was investigate. It was stated that these fluxes could diminish the firing temperature of the experimental bodies by 100-150 C, and assure a small increase in their bending strength and as well in their thermal shock resistance. (author). 7 refs, 3 figs, 3 tabs

  20. DVD-d. "Borat", "United 93", "Must Daalia", "Vimm 2" / Andres Laasik

    Index Scriptorium Estoniae

    Laasik, Andres, 1960-2016

    2007-01-01

    Uued mängufilmide DVD-d : Larry Charlesi "Borat" (peaosas Sacha Baron Cohen; USA 2006), Paul Greengrassi "United 93" (USA 2006), Brian De Palma "Must Daalia" ("The Black Dahlia", USA 2006), Takashi Shimizu "Vimm 2" ("The Grudge 2", USA 2006)

  1. 76 FR 74831 - Aging Management of Stainless Steel Structures and Components in Treated Borated Water

    Science.gov (United States)

    2011-12-01

    ...: On November 8, 2011 (76 FR 69292) the U.S. Nuclear Regulatory Commission (NRC) published in the.... FOR FURTHER INFORMATION CONTACT: Dr. John Wise, Division of License Renewal, Office of Nuclear Reactor... components exposed to treated borated water. Specifically, for pressurized water reactors, the...

  2. Bis(pyrazolyl)(thioimidazolyl)borate ligands: the missing member in the N3...S3 scorpionate series.

    Science.gov (United States)

    Benkmil, Boumahdi; Ji, Mian; Vahrenkamp, Heinrich

    2004-12-27

    The anionic bis(pyrazolyl)(thioimidazolyl)borate ligands BpMt(R) with R = tert-butyl and isopropyl were obtained as their potassium salts by reacting potassium tris(pyrazolyl)borate with the corresponding thioimidazoles in the melt at 150 degrees C. They were applied to form some tetrahedral zinc complexes and identified by the crystal structures of (BpMt(t-Bu))ZnCl and (BpMt(i-Pr))Zn-SC(6)H(4)-p-Cl. PMID:15606159

  3. Synthesis and properties of bis(p-aminosalicyl)borates of the 2 group metals of periodic system

    International Nuclear Information System (INIS)

    Potassium, zinc and cadmium bis(n-aminosalicyl) borates of the Me[N2C14H10O6B]2xnH2O composition have been obtained. The densities and crystal lattice plane spacings have been determined and the IR absorption spectra have been recorded. A tentative structure of the bis(n-aminosalicyl) borates is suggested on the basis of analysis of the IR spectra

  4. Borate cross-linked graphene oxide-chitosan as robust and high gas barrier films

    Science.gov (United States)

    Yan, Ning; Capezzuto, Filomena; Lavorgna, Marino; Buonocore, Giovanna G.; Tescione, Fabiana; Xia, Hesheng; Ambrosio, Luigi

    2016-05-01

    Chitosan (CS) is one of the most promising polymers due to its biocompatibility, biodegradability, and natural abundance. However, its poor mechanical and barrier properties make it difficult to satisfy a wide range of applications. Herein, borate ions, originating from the hydrolysis of sodium tetraborate decahydrate (borax), have been used to crosslink chitosan and graphene oxide (GO) nanocomposites. Chitosan films consisting of 1.0 wt% boron and 1.0 wt% GO exhibit a significant improvement in both the toughness and oxygen barrier properties compared to pristine chitosan. In particular the tensile strength of the samples after thermal treatment increases by ~160% compared to pristine chitosan, whereas their oxygen permeability reduces by ~90%. This is ascribed to the chemical crosslinking between chitosan and GO nanoplatelets through borate ions, as well as the formation of a layered morphology with graphene nanoplatelets oriented parallel to the sample surface. The exceptional robust and high gas barrier film has promising application in the packaging industry. The borate-crosslinking chemistry represents the potential strategy for improving properties of other polymer nanocomposites.Chitosan (CS) is one of the most promising polymers due to its biocompatibility, biodegradability, and natural abundance. However, its poor mechanical and barrier properties make it difficult to satisfy a wide range of applications. Herein, borate ions, originating from the hydrolysis of sodium tetraborate decahydrate (borax), have been used to crosslink chitosan and graphene oxide (GO) nanocomposites. Chitosan films consisting of 1.0 wt% boron and 1.0 wt% GO exhibit a significant improvement in both the toughness and oxygen barrier properties compared to pristine chitosan. In particular the tensile strength of the samples after thermal treatment increases by ~160% compared to pristine chitosan, whereas their oxygen permeability reduces by ~90%. This is ascribed to the chemical

  5. Bone bonding ability of some borate bio-glasses and their corresponding glass-ceramic derivatives

    Directory of Open Access Journals (Sweden)

    Fatma H. Margha

    2012-12-01

    Full Text Available Ternary borate glasses from the system Na2O·CaO·B2O3 together with soda-lime-borate samples containing 5 wt.% of MgO, Al2O3, SiO2 or P2O5 were prepared. The obtained glasses were converted to their glass-ceramic derivatives by controlled heat treatment. X-ray diffraction was employed to investigate the separated crystalline phases in glass-ceramics after heat treatment of the glassy samples. The glasses and corresponding glass-ceramics after immersion in water or diluted phosphate solution for extended times were characterized by the grain method (adopted by several authors and recommended by ASTM and Fourier-transform infrared spectra to justify the formation of hydroxyapatite as an indication of the bone bonding ability. The influence of glass composition on bioactivity potential was discussed too.

  6. Optical absorption and fluorescence properties of Er3+ in sodium borate glass

    Indian Academy of Sciences (India)

    Y C Ratnakaram; J Lakshmi; R P S Chakradhar

    2005-08-01

    Spectroscopic properties of Er3+ ions in sodium borate glass have been studied. The indirect and direct optical band gaps (opt) and energy level parameters (Racah (1, 2 and 3), spin-orbit (4f) and configurational interaction ()) are evaluated. Spectral intensities for various absorption bands of Er3+ doped sodium borate glass are calculated. Using Judd–Ofelt intensity parameters (2, 4, 6), radiative transition probabilities (), branching ratios () and integrated absorption cross sections ( ) are reported for certain transitions. The radiative lifetimes (R) for different excited states are estimated. From the fluorescence spectra, the emission cross section (p) for the transition, ${}^{4}I_{13/2} \\rightarrow {}^{4}I_{15/2}$ is reported.

  7. Computational investigation of the neutron shielding and activation characteristics of borated concrete with polyethylene aggregate

    Energy Technology Data Exchange (ETDEWEB)

    Park, S.J.; Jang, J.G.; Lee, H.K., E-mail: leeh@kaist.ac.kr

    2014-09-15

    This paper presents the result of a computational study to investigate the neutron shielding and activation characteristics of concretes containing boron carbide and polyethylene. Various mixes were considered with changes in the contents of boron carbide and polyethylene aggregate. The Monte Carlo simulation code MCNP-5 was utilized to determine the transmission of neutron through concrete at different energies from 0.1 eV to 1 MeV, and ORIGEN-S code was then used to predict activation characteristics of the concretes. It was shown that the replacement of polyethylene in borated concrete greatly enhanced the shielding efficiency of the concrete, and total activity levels of the concrete were considerably decreased with this replacement. Furthermore, double-layered structures having the first layer of polyethylene aggregate-replaced concrete and the second layer of 2 wt% borated concrete are shown to improve shielding efficiency more significantly than monolithic structures.

  8. Preparation of Chromium Oxide Coatings on Aluminum Borate Whiskers by a Hydrothermal Deposition Process

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Aluminum borate whiskers (9Al2O32B2O3) can be used to reinforce aluminum alloys to produce light and strong composites. However, the adverse interfacial reactions between the whiskers and the aluminum alloys inhibit their practical uses; therefore, a protective coating is needed on whiskers. In this work, aluminum borate whiskers were coated with chromium-coating deposits in a hydrothermal solution containing CrCl3, Na2C4H4O6, NaPH2O2, and H3BO3. The presence of the impurity P in the hydrothermal deposits can be avoided by reducing the amount of NaPH2O2 in the coating solution. Thermodynamic analysis was used to discuss the behavior of ions in the coating process. The subsequent heating of the hydrothermal products in air at 800 ℃ yielded smooth Cr2O3 films with a thickness of 0.060.07 μm.

  9. Molecular design of nanometric zinc borate-containing polyimide as a route to flame retardant materials

    International Nuclear Information System (INIS)

    Zinc borate (Zn2B6O11.3H2O) nanoparticles were successfully prepared by using an emulsion liquid membrane (W/O/W emulsion) to control the size of particles with Na2B4O7.10H2O, boric acid and ZnSO4.7H2O as raw materials. All materials were dispersed with the polyimide (PI) precursor, poly (amic acid). Using a combination of dissolving the poly (amic acid) and mixing fatty acid surfactant-coated zinc borate nanoparticles; we have demonstrated the formation of nanocomposites with uniform nanoparticles dispersion. We report the first deposition of nanocomposite polyimides from solution using spin-coating. The microstructures and morphology of the as-obtained samples were studied by X-ray diffraction (XRD), infrared spectra (IR), scanning electron microscopy (SEM) equipped with an energy-dispersive X-ray spectrometer (EDX), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA)

  10. Physical and optical characterization of Er3+ doped lead-zinc-borate glass.

    Science.gov (United States)

    Sooraj Hussain, N; Cardoso, P J; Hungerford, G; Gomes, M J M; Ali, Nasar; Santos, J D; Buddhudu, S

    2009-06-01

    This paper reports on the systematic optical characterization of Er3+ (1.0%) doped lead-zinc-borate glass from the measured absorption, luminescence and fluorescence lifetime decay curve profiles. By the application of the Judd-Ofelt theory, spectral intensities of the absorption bands have been analysed and these absorption results have been used in evaluating the luminescence properties of the Er3+ doped lead-zinc-borate glass. Stimulated emission cross-sections (sigmapE) of the measured emission transitions have been computed. Based on the measured glass density, and refractive indices, other related physical parameters have also been evaluated. Further, the structural and morphology of the glass material have also been investigated from X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy analysis. PMID:19504881

  11. Fluorescence properties of Eu3+ ions doped borate and fluoroborate glasses containing lithium, zinc and lead.

    Science.gov (United States)

    Venkatramu, V; Babu, P; Jayasankar, C K

    2006-02-01

    The influence of glass composition on the fluorescence properties of Eu3+ ions doped borate and fluoroborate glasses modified with Li+, Zn2+ and Pb2+ cations have been investigated. The magnitude of splittings of 7F1 levels are analyzed using crystal-field (CF) analysis. The relative intensities of 5D0 --> 7F2 to 5D0 --> 7F1 transitions, crystal-field strength parameters and decay times of the 5D0 level have been determined and are found to be lower for Pb based glasses than those of Zn/Li based glasses. The lifetimes of 5D0 level are found to increase when borate glasses are modified with pure fluorides than with oxides and oxyfluorides. The fluorescence decay of 5D0 level fits perfect single exponential in the Eu3+:glass systems studied which indicates the absence of energy transfer between Eu3+ ions in these glasses. PMID:15979397

  12. Synergistic effects of zinc borate and aluminium trihydroxide on flammability behaviour of aerospace epoxy system

    Directory of Open Access Journals (Sweden)

    2009-06-01

    Full Text Available The flame retardancy of mono-component epoxy resin (RTM6, widely used for aerospace composites, treated with zinc borate (ZB, aluminium trihydroxide (ATH and their mixtures at different concentrations have been investigated by morphological and thermal characterization. Cone calorimeter data reveal that combustion behaviour, heat release rate peak (PHRR and heat release rate average (HRR Average of RTM6 resin decrease substantially when synergistic effects of zinc borate and aluminium trihydroxide intervene. Thermogravimetric (TGA results and analysis of the residue show that addition higher than 20% w/w of ZB, ATH, and their mixture greatly promotes RTM6 char formation acting as a barrier layer for the fire development. Depending upon the different used flame additives, SEM micrographs indicate that the morphology of residual char could vary from a compact amalgam-like structure, for the RTM6+ZB system, to a granular structure, characterized by very small particles of degraded resin and additive for the ATH.

  13. Moessbauer spectroscopic study of the formation of non-bridging oxygen in the potassium borate glasses

    International Nuclear Information System (INIS)

    Moessbauer spectroscopic study was performed to investigate the formation of non-bridging oxygen in the potassium borate glasses denoted by the formula of x K2O(100 - x) B2O3 x 7 Fe2O3 (0 3+ decreased continuously with the concentration of the alkali oxide in the glass, showing the increase of the symmetry around the Fe3+ ions. The isomer shift value also decreased in almost the same x region. The drastic decrease of Moessbauer parameters was attributed to the formation of non-bridging oxygen at the adjacent site of the Fe3+ ions. In the region of lower alkali content (less than 10 mol%), Moessbauer spectra only showed the absorption due to α-Fe2O3. X-ray powder diffraction patterns also displayed the existence of α-Fe2O3, together with the microcrystal of potassium borate. (orig.)

  14. Structural, optical and glass transition studies on Nd3+-doped lead bismuth borate glasses

    International Nuclear Information System (INIS)

    Nd3+-doped lead bismuth borate (PbO-Bi2O3-B2O3) glasses were prepared with different concentrations of Nd3+. The structural studies were done through FTIR spectral analysis. The glass transition studies were done through differential scanning calorimetry. The optical analysis was done by using Judd-Ofelt theory. The structural study reveals that the glass has [BiO3], BO4, BO3 and PbO4 units as the local structures

  15. High electric field and switching phenomena in some borate and vanadate glasses

    International Nuclear Information System (INIS)

    The study of conduction mechanism, high-field characteristics and switching phenomena of borate and vanadate glasses have been extended to high electric fields of the order of 5.7·104 V cm-1 or higher (beyond the ohmic region), when memory switching phenomena are observed in thin blown films of ZnO-B2O3 and in thicker BaO-V2O5 glasses. Typical voltage-current characteristics are given and explained

  16. Growth Kinetics and Electronic Properties of Passive Film of Zinc in Borate Buffer Solution

    International Nuclear Information System (INIS)

    We have investigated the growth kinetics and electronic properties of passive film of zinc in borate buffer solution. The oxide film formed in passivation process of zinc has showed the electronic properties of n-type semiconductor based on the Mott-Schottky equation. And it was found out that the oxide film consisted ZnO and Zn(OH)2 was composed of deep and shallow donors

  17. Optical characterization of TCO films on borate glasses for high efficiency solar cells

    Science.gov (United States)

    Steudel, Franziska; Miclea, Paul-Tiberiu; Teuscher, Nico; Heilmann, Andreas; Schweizer, Stefan

    2012-06-01

    Two different transparent conductive oxides (TCO) were deposited by magnetron sputtering on borate glasses. The influence of sputtering conditions on optical, electrical and microstructural properties was much higher for indium tin oxide (ITO) than for aluminium-doped zinc oxide (AZO) films. Specific resistivity values obtained from simulation of the optical spectra are in good agreement with values obtained from four-point probe measurements.

  18. Thermal Properties of Borate Crystals for High Power Optical Parametric Chirped-Pulse Amplification

    OpenAIRE

    Riedel, Robert; Rothhardt, J.; Tünnermann, A.; Prandolini, Mark; Tavella, F.; Beil, K.; Gronloh, B.; Klenke, A.; Höppner, H.; M. Schulz; Teubner, U.; Kraenkel, Christian; Limpert, J.

    2014-01-01

    The potential of borate crystals, BBO, LBO and BiBO, for high average power scaling of optical parametric chirped-pulse amplifiers is investigated. Up-to-date measurements of the absorption coefficients at 515 nm and the thermal conductivities are presented. The measured absorption coefficients are a factor of 10–100 lower than reported by the literature for BBO and LBO. For BBO, a large variation of the absorption coefficients was found between crystals from different manufacturers. The line...

  19. Surprising coordination for plutonium in the first plutonium(III) borate.

    Science.gov (United States)

    Wang, Shuao; Alekseev, Evgeny V; Depmeier, Wulf; Albrecht-Schmitt, Thomas E

    2011-03-21

    The first plutonium(III) borate, Pu(2)[B(12)O(18)(OH)(4)Br(2)(H(2)O)(3)]·0.5H(2)O, has been prepared by reacting plutonium(III) with molten boric acid under strictly anaerobic conditions. This compound contains a three-dimensional polyborate network with triangular holes that house the plutonium(III) sites. The plutonium sites in this compound are 9- and 10-coordinate and display atypical geometries.

  20. Establishment of PCP composition diagrams for cementations of borate wastes using response surface methodology

    International Nuclear Information System (INIS)

    For the purpose of quality assurance, it is requested by the regulatory authority in the solidification of low-level radioactive waste (LLRW) to implement the 'process control program (PCP)', in which the condition of solidification should be decided in advance of solidification according to the so-called 'PCP composition diagrams', to assure that the condition of solidification is within established process parameters and that the quality of solidified LLRW meets quality criteria. In this paper, PCP composition diagrams for the cementation of radioactive liquid borate wastes were established with response surface methodology, including using the simplex centroid design to allocate experimental conditions and statistical curve-fitting techniques to construct quality models. The constructed models were verified to have a confidence level higher than 95% by doing the lack-of-fit test on them. Quality contours of solidified borate wastes were thus established based on mathematical and statistical principles and have been used as composition diagrams in the process control program of radioactive borate wastes solidification at Ma-An-Shan nuclear power station of Taiwan Power Company. The solidification agent used in this study was a mixture of Portland type-II cement and lime powder with a weight ratio of 1/0.22. Quality contours for solidified borate wastes including free-standing water content, compressive strength, water resistance, thawing and freezing resistance, irradiation resistance, and leaching resistance were established. Characteristics of these quality contours were also discussed. With these contours, the performance of the final waste form can be assured and consequently a volume reduction will also be achieved, when the PCP is implemented. (author)

  1. Process and plant for the treatment of radioactive residues from borate containing sewage

    International Nuclear Information System (INIS)

    Radioactive residues from borate-containing waste water can be concentrated in an evapouration plant. The concentrate is further processed by the addition of sodium hydroxide giving molar proportions of sodium to boron of approx. 0.7 or 0.3. The concentrates are then boiled down in a heatable container to at least twice the original solid matter content and then filled into transport containers which are then removed for safe intermediate storage. (orig.)

  2. Comparison of Lithium Gadolinium Borate Crystal Shards in Scintillating and Nonscintillating Plastic Matrices

    OpenAIRE

    Kazkaz, Kareem; Bowden, Nathaniel S.; Pedretti, Marisa

    2011-01-01

    We present a method for detecting neutrons using scintillating lithium gadolinium borate crystal shards in a plastic matrix while maintaining high gamma rejection. We have procured two cylindrical detectors, 5"\\times5", containing 1% crystal by mass. Crystal shards have a typical dimension of 1 mm. One detector was made with scintillating plastic, and one with nonscintillating plastic. Pulse shape analysis was used to reject gamma ray backgrounds. The scintillating detector was measured to ha...

  3. Decoupling of uranium metal with borated plaster using 252Cf nose analysis methods

    International Nuclear Information System (INIS)

    The use of borated plaster to isolate uranium (93.2 wt % 235U) metal was studied in a series of subcritical experiments with uranium metal cylinders (7.0 in. diam, 2.0 in. thick) and slabs (approx.1.4 x approx.5.4 x approx.10.1 in. dimensions). In the cylindrical experiments, the thickness of borated plaster was varied up to 10 in. and the subcriticality measured using the 252Cf-source-driven neutron noise analysis method. In the experiments with the uranium slabs, an array of slabs 3 wide and 8 high was assembled in steps to demonstrate the subcriticality of this array with 3.75-in.-thick borated plaster as an isolating material between all uranium slabs. In the slab experiments, both noise analysis and source neutron multiplication measurements were performed. Before assembly of the slab array the presence of boron in the plaster was verified by neutron transmission and gamma-ray spectrometry measurements

  4. Thermal stability and spectroscopic properties of Ho3+doped tellurite-borate glasses

    Institute of Scientific and Technical Information of China (English)

    杨艳民; 刘延洲; 蔡培庆; Ramzi Maalej; Hyo Jin Seo

    2015-01-01

    Ho3+ions doped tellurite-borate glass samples with varying compositions were prepared. The compositional dependence on phenomenological Judd-Ofelt parameters was compared in different kinds of rare earth ions doped tellurite-borate glasses. Two methods were used to obtain radiative transition probability of 5I7 level with the aim of assuring the fitting quality. The integral ab-sorption cross-sections and line shapes corresponding to 5I8→5G6 and 5I8→5I7 transition of Ho3+ions were investigated in tellurite-borate glasses. The obtained data indicated that the integral absorption cross-sections corresponding to 5I8→5G6 transition of Ho3+ions mainly depended on phenomenological Judd-Ofelt parameter,Ω2, because 5I8→5G6 transition belonged to hypersensitive transitions, which led to a largerΩ2 value. The change of line shapes of absorption spectra corresponding to 5I8→5G6 and 5I8→5I7 transitions of Ho3+ions came from the lower energy regions, which could be attributed to the changed distribution of Stark levels and thermal population.

  5. Evaluation of borate bioactive glass scaffolds with different pore sizes in a rat subcutaneous implantation model.

    Science.gov (United States)

    Deliormanli, Aylin M; Liu, Xin; Rahaman, Mohamed N

    2014-01-01

    Borate bioactive glass has been shown to convert faster and more completely to hydroxyapatite and enhance new bone formation in vivo when compared to silicate bioactive glass (such as 45S5 and 13-93 bioactive glass). In this work, the effects of the borate glass microstructure on its conversion to hydroxyapatite (HA) in vitro and its ability to support tissue ingrowth in a rat subcutaneous implantation model were investigated. Bioactive borate glass scaffolds, designated 13-93B3, with a grid-like microstructure and pore widths of 300, 600, and 900 µm were prepared by a robocasting technique. The scaffolds were implanted subcutaneously for 4 weeks in Sprague Dawley rats. Silicate 13-93 glass scaffolds with the same microstructure were used as the control. The conversion of the scaffolds to HA was studied as a function of immersion time in a simulated body fluid. Histology and scanning electron microscopy were used to evaluate conversion of the bioactive glass implants to hydroxyapatite, as well as tissue ingrowth and blood vessel formation in the implants. The pore size of the scaffolds was found to have little effect on tissue infiltration and angiogenesis after the 4-week implantation.

  6. Dosimetric properties of dysprosium doped calcium magnesium borate glass subjected to Co-60 gamma ray

    International Nuclear Information System (INIS)

    Thermoluminescence (TL) dosimetric properties of dysprosium doped calcium magnesium borate (CMB:Dy) glass are presented. This study is deemed to understand the application of calcium as the modifier in magnesium borate glass with the presence of dysprosium as the activator to be performed as TL dosimeter (TLD). The study provides fundamental knowledge of a glass system that may lead to perform new TL glass dosimetry application in future research. Calcium magnesium borate glass systems of (70-y) B2O3 − 20 CaO – 10 MgO-(y) Dy2O3 with 0.05  mol % ≤ y ≤ 0.7  mol % of dyprosium were prepared by melt-quenching technique. The amorphous structure and TL properties of the prepared samples were determined using powder X-ray diffraction (XRD) and TL reader; model Harshaw 4500 respectively. The samples were irradiated to Co-60 gamma source at a dose of 50 Gy. Dosimetric properties such as annealing procedure, time temperature profile (TTP) setting, optimization of Dy2O3 concentration of 0.5 mol % were determined for thermoluminescence dosimeter (TLD) reader used

  7. Corrosion mechanism and bioactivity of borate glasses analogue to Hench’s bioglass

    Directory of Open Access Journals (Sweden)

    Mona A. Ouis

    2012-09-01

    Full Text Available Bioactive borate glasses (from the system Na2O-CaO-B2O3-P2O5 and corresponding glass-ceramics as a new class of scaffold material were prepared by full replacement of SiO2 with B2O3 in Hench patented bioactive glass. The prepared samples were investigated by differential thermal analysis (DTA, Fourier transform infrared (FTIR spectroscopy and X-ray diffraction (XRD analysis. The DTA data were used to find out the proper heat treatment temperatures for preparation of the appropriate glass-ceramics with high crystallinity. The prepared crystalline glass-ceramics derivatives were examined by XRD to identify the crystalline phases that were precipitated during controlled thermal treatment. The FTIR spectroscopy was used to justify the formation of hydroxyapatite as an indication of the bioactivity potential or activity of the studied ternary borate glasses or corresponding glass-ceramics after immersion in aqueous phosphate solution. The corrosion results are interpreted on the basis of suggested recent views on the corrosion mechanism of such modified borate glasses in relation to their composition and constitution.

  8. Borate-treated strand board from southern wood species: Resistance against decay and mold fungi

    Directory of Open Access Journals (Sweden)

    Xinwu Xu

    2013-02-01

    Full Text Available Combined decay and mold resistance of zinc borate-(ZB and calcium borate-(CB treated oriented strand board (OSB from southern mixed hardwood (MHW and southern yellow pine (SYP was investigated. Tests were done with a brown-rot fungus, Gloeophyllum trabeum, and a white-rot fungus, Trametes versicolor, for 8 and 12 weeks, respectively. Wood species and fungus type had significant influence on the decay resistance. Decay caused by the brown-rot fungus was evident for all untreated SYP and mixed MHW controls. White-rot fungus did not cause significant sample weight loss for either species group. In the SYP OSB control inoculated with G. trabeum, the hyphae were abundant in wood rays and cell walls where they primarily penetrated through bordered and simple pits. The incorporation of ZB and CB into OSB provided significant protection against the fungi with no significant weight loss observed in the treated OSB. Microscopic analysis showed distinct evidence of fungal colonization and a thinning pattern of cell wall material. Untreated OSB samples from MHW and commercial OSBs were most susceptible to mold growth after 6 weeks. The borate-modified OSB from MHW and SYP effectively prevented the mold growth.

  9. VO2+ ions in zinc lead borate glasses studied by EPR and optical absorption techniques.

    Science.gov (United States)

    Prakash, P Giri; Rao, J Lakshmana

    2005-09-01

    Electron paramagnetic resonance (EPR) and optical absorption spectra of vanadyl ions in zinc lead borate (ZnO-PbO-B2O3) glass system have been studied. EPR spectra of all the glass samples exhibit resonance signals characteristic of VO2+ ions. The values of spin-Hamiltonian parameters indicate that the VO2+ ions in zinc lead borate glasses were present in octahedral sites with tetragonal compression and belong to C4V symmetry. The spin-Hamiltonian parameters g and A are found to be independent of V2O5 content and temperature but changing with ZnO content. The decrease in Deltag( parallel)/Deltag( perpendicular) value with increase in ZnO content indicates that the symmetry around VO2+ ions is more octahedral. The decrease in intensity of EPR signal above 10 mol% of V2O5 is attributed to a fall in the ratio of the number of V4+ ions (N4) to the number of V5+ ions (N5). The number of spins (N) participating in resonance was calculated as a function of temperature for VO2+ doped zinc lead borate glass sample and the activation energy was calculated. From the EPR data, the paramagnetic susceptibility was calculated at various temperatures and the Curie constant was evaluated from the 1/chi-T graph. The optical absorption spectra show single absorption band due to VO2+ ions in tetragonally distorted octahedral sites. PMID:16043053

  10. Microwave and conventional preparation of Zinc borate glass: Eu{sup 3+} ion as luminescent probe

    Energy Technology Data Exchange (ETDEWEB)

    Mandal, Ashis K., E-mail: ashis@cgcri.res.in; Balaji, S., E-mail: sbalaji@cgcri.res.in; Sen, Ranjan, E-mail: rsen@cgcri.res.in

    2014-12-05

    Highlights: • IR transparent Zinc borate glass is prepared using microwave heating. • Glass transition temperature of microwave melted glass is found higher than that of glass prepared in conventional melting. • Low OH concentration in glass can be prepared in microwave heating. • We report higher reduction of Eu{sup 3+} to Eu{sup 2+} in microwave processing of Zinc borate glass. - Abstract: Transparent Zinc borate glass is melted using microwave energy as an alternative heating route to conventional resistive heating. A comparative study of the properties of the glasses prepared by both the methods is conducted by adopting X-ray diffraction (XRD), Differential scanning calorimetry (DSC), UV–VIS–NIR spectroscopy, Fourier transform infrared (FTIR) spectroscopy, Refractive Indices (RI). Amorphous nature of samples is confirmed by X-ray diffraction study. Glass transition temperature (T{sub g}) of microwave melted glass is found ∼7–9 °C higher than that of glass prepared in conventional melting. OH content is found less than 250 ppm in microwave melted glass whereas it is above 330 ppm in conventional melted glasses. Photoluminescence study of Eu{sub 2}O{sub 3} doped glass prepared in microwave heating indicates higher reduction of Eu{sup 3+} → Eu{sup 2+} than the glass melted in conventional route. Thus, microwave processing can be an alternative energy efficient, time saving, environmental friendly glass preparation method.

  11. Microwave and conventional preparation of Zinc borate glass: Eu3+ ion as luminescent probe

    International Nuclear Information System (INIS)

    Highlights: • IR transparent Zinc borate glass is prepared using microwave heating. • Glass transition temperature of microwave melted glass is found higher than that of glass prepared in conventional melting. • Low OH concentration in glass can be prepared in microwave heating. • We report higher reduction of Eu3+ to Eu2+ in microwave processing of Zinc borate glass. - Abstract: Transparent Zinc borate glass is melted using microwave energy as an alternative heating route to conventional resistive heating. A comparative study of the properties of the glasses prepared by both the methods is conducted by adopting X-ray diffraction (XRD), Differential scanning calorimetry (DSC), UV–VIS–NIR spectroscopy, Fourier transform infrared (FTIR) spectroscopy, Refractive Indices (RI). Amorphous nature of samples is confirmed by X-ray diffraction study. Glass transition temperature (Tg) of microwave melted glass is found ∼7–9 °C higher than that of glass prepared in conventional melting. OH content is found less than 250 ppm in microwave melted glass whereas it is above 330 ppm in conventional melted glasses. Photoluminescence study of Eu2O3 doped glass prepared in microwave heating indicates higher reduction of Eu3+ → Eu2+ than the glass melted in conventional route. Thus, microwave processing can be an alternative energy efficient, time saving, environmental friendly glass preparation method

  12. The structural analysis of zinc borate glass by laboratory EXAFS and X-ray diffraction measurements

    International Nuclear Information System (INIS)

    The structure of zinc borate glass has been investigated by laboratory EXAFS and X-ray diffraction measurement as preliminary investigations for the detailed study in SPring-8. The zinc borate glass was prepared in the range from 40 to 65 mol% of zinc oxide content. The X-ray diffraction was measured by horizontal θ-θ goniometer with 60 kV and 300 mA output of Mo target. The EXAFS of zinc borate glass was measured by laboratory EXAFS system with 20 kV, 100 mA output of Mo target for the K absorption edge of zinc atom. From the X-ray diffraction and the EXAFS measurements, it is found that the zinc ion is surrounded by four oxygen atoms and formed a tetrahedral structure whose (Zn-O) distance is about 2 A and that the structure is unchanged with the zinc oxide content. The diffraction data show that the neighboring structure of boron atom transforms from BO4 tetrahedra to BO3 tetragonal planar structure with increasing of the zinc oxide content. (author)

  13. Dosimetric properties of dysprosium doped calcium magnesium borate glass subjected to Co-60 gamma ray

    Science.gov (United States)

    Omar, R. S.; Wagiran, H.; Saeed, M. A.

    2016-01-01

    Thermoluminescence (TL) dosimetric properties of dysprosium doped calcium magnesium borate (CMB:Dy) glass are presented. This study is deemed to understand the application of calcium as the modifier in magnesium borate glass with the presence of dysprosium as the activator to be performed as TL dosimeter (TLD). The study provides fundamental knowledge of a glass system that may lead to perform new TL glass dosimetry application in future research. Calcium magnesium borate glass systems of (70-y) B2O3 - 20 CaO - 10 MgO-(y) Dy2O3 with 0.05 mol % ≤ y ≤ 0.7 mol % of dyprosium were prepared by melt-quenching technique. The amorphous structure and TL properties of the prepared samples were determined using powder X-ray diffraction (XRD) and TL reader; model Harshaw 4500 respectively. The samples were irradiated to Co-60 gamma source at a dose of 50 Gy. Dosimetric properties such as annealing procedure, time temperature profile (TTP) setting, optimization of Dy2O3 concentration of 0.5 mol % were determined for thermoluminescence dosimeter (TLD) reader used.

  14. Dosimetric properties of dysprosium doped calcium magnesium borate glass subjected to Co-60 gamma ray

    Energy Technology Data Exchange (ETDEWEB)

    Omar, R. S., E-mail: ratnasuffhiyanni@gmail.com; Wagiran, H., E-mail: husin@utm.my; Saeed, M. A. [Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, 81310 Johor Bahru (Malaysia)

    2016-01-22

    Thermoluminescence (TL) dosimetric properties of dysprosium doped calcium magnesium borate (CMB:Dy) glass are presented. This study is deemed to understand the application of calcium as the modifier in magnesium borate glass with the presence of dysprosium as the activator to be performed as TL dosimeter (TLD). The study provides fundamental knowledge of a glass system that may lead to perform new TL glass dosimetry application in future research. Calcium magnesium borate glass systems of (70-y) B{sub 2}O{sub 3} − 20 CaO – 10 MgO-(y) Dy{sub 2}O{sub 3} with 0.05  mol % ≤ y ≤ 0.7  mol % of dyprosium were prepared by melt-quenching technique. The amorphous structure and TL properties of the prepared samples were determined using powder X-ray diffraction (XRD) and TL reader; model Harshaw 4500 respectively. The samples were irradiated to Co-60 gamma source at a dose of 50 Gy. Dosimetric properties such as annealing procedure, time temperature profile (TTP) setting, optimization of Dy{sub 2}O{sub 3} concentration of 0.5 mol % were determined for thermoluminescence dosimeter (TLD) reader used.

  15. Low temperature phase barium borate: A new optical limiter in continuous wave and nano pulsed regime

    Science.gov (United States)

    Babeela, C.; Girisun, T. C. Sabari

    2015-11-01

    Low temperature phase barium borate was synthesized by hydrothermal method. XRD analysis confirms the formation of γ-BBO or hydrated barium polyborate (Ba3B6O9(OH)6) which crystallizes in monoclinic system in the P2/c space group. The molecular structure analysis shows the presence of dominant BO4 unit and the hydrated nature of material. γ-BBO exhibits sharp absorption edge at 202 nm and highly transparency in the UV-Visible-NIR region. The peak at 347 nm in the emission spectrum is due to the presence of self-trapped exciton. The third order nonlinear optical properties and limiting behavior of low temperature barium borate in both pulsed and continuous wave regime were studied. The effective 2PA absorption coefficient of γ-BBO under ns pulse excitation is estimated to be 0.38 × 10-10 m/W. The nonlinear absorption coefficient, refractive index and optical susceptibility of the material in cw regime were found to be in the order of 10-5 m W-1, 10-12 m2 W-1, 10-6 esu respectively. In both regimes, low temperature phase barium borate exhibits better optical limiting properties than high temperature phase β-BBO.

  16. TRPM7 channel regulates PDGF-BB-induced proliferation of hepatic stellate cells via PI3K and ERK pathways

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Ling, E-mail: fangling_1984@126.com; Zhan, Shuxiang; Huang, Cheng; Cheng, Xi; Lv, Xiongwen; Si, Hongfang; Li, Jun, E-mail: lj@ahmu.edu.cn

    2013-11-01

    TRPM7, a non-selective cation channel of the TRP channel superfamily, is implicated in diverse physiological and pathological processes including cell proliferation. Recently, TRPM7 has been reported in hepatic stellate cells (HSCs). Here, we investigated the contribution role of TRPM7 in activated HSC-T6 cell (a rat hepatic stellate cell line) proliferation. TRPM7 mRNA and protein were measured by RT-PCR and Western blot in rat model of liver fibrosis in vivo and PDGF-BB-activated HSC-T6 cells in vitro. Both mRNA and protein of TRPM7 were dramatically increased in CCl{sub 4}-treated rat livers. Stimulation of HSC-T6 cells with PDGF-BB resulted in a time-dependent increase of TRPM7 mRNA and protein. However, PDGF-BB-induced HSC-T6 cell proliferation was inhibited by non-specific TRPM7 blocker 2-aminoethoxydiphenyl borate (2-APB) or synthetic siRNA targeting TRPM7, and this was accompanied by downregulation of cell cycle proteins, cyclin D1, PCNA and CDK4. Blockade of TRPM7 channels also attenuated PDGF-BB induced expression of myofibroblast markers as measured by the induction of α-SMA and Col1α1. Furthermore, the phosphorylation of ERK and AKT, associated with cell proliferation, decreased in TRPM7 deficient HSC-T6 cells. These observations suggested that TRPM7 channels contribute to perpetuated fibroblast activation and proliferation of PDGF-BB induced HSC-T6 cells via the activation of ERK and PI3K pathways. Therefore, TRPM7 may constitute a useful target for the treatment of liver fibrosis. - Highlights: • Upregulation of TRPM7 mRNA and protein in the fibrotic livers from CCl{sub 4}-treated rats. • Increasing expression of TRPM7 mRNA and protein during HSC activation. • Blockade of TRPM7 inhibited the PDGF-BB induced proliferation of HSC-T6 cells. • Blockade of TRPM7 decreased α-SMA and Col1α1 expressions in activated HSC-T6 cells. • TRPM7 up-regulation contributes to the activation of ERK and AKT pathways.

  17. Two chromogranin a-derived peptides induce calcium entry in human neutrophils by calmodulin-regulated calcium independent phospholipase A2.

    Directory of Open Access Journals (Sweden)

    Dan Zhang

    Full Text Available BACKGROUND: Antimicrobial peptides derived from the natural processing of chromogranin A (CgA are co-secreted with catecholamines upon stimulation of chromaffin cells. Since PMNs play a central role in innate immunity, we examine responses by PMNs following stimulation by two antimicrobial CgA-derived peptides. METHODOLOGY/PRINCIPAL FINDINGS: PMNs were treated with different concentrations of CgA-derived peptides in presence of several drugs. Calcium mobilization was observed by using flow cytometry and calcium imaging experiments. Immunocytochemistry and confocal microscopy have shown the intracellular localization of the peptides. The calmodulin-binding and iPLA2 activating properties of the peptides were shown by Surface Plasmon Resonance and iPLA2 activity assays. Finally, a proteomic analysis of the material released after PMNs treatment with CgA-derived peptides was performed by using HPLC and Nano-LC MS-MS. By using flow cytometry we first observed that after 15 s, in presence of extracellular calcium, Chromofungin (CHR or Catestatin (CAT induce a concentration-dependent transient increase of intracellular calcium. In contrast, in absence of extra cellular calcium the peptides are unable to induce calcium depletion from the stores after 10 minutes exposure. Treatment with 2-APB (2-aminoethoxydiphenyl borate, a store operated channels (SOCs blocker, inhibits completely the calcium entry, as shown by calcium imaging. We also showed that they activate iPLA2 as the two CaM-binding factors (W7 and CMZ and that the two sequences can be aligned with the two CaM-binding domains reported for iPLA2. We finally analyzed by HPLC and Nano-LC MS-MS the material released by PMNs following stimulation by CHR and CAT. We characterized several factors important for inflammation and innate immunity. CONCLUSIONS/SIGNIFICANCE: For the first time, we demonstrate that CHR and CAT, penetrate into PMNs, inducing extracellular calcium entry by a CaM-regulated i

  18. Synthesis, structure, and properties of low-spin manganese(III)-poly(pyrazolyl)borate complexes.

    Science.gov (United States)

    Hossain, Ferdaus; Rigsby, Matthew A; Duncan, Cole T; Milligan, Paul L; Lord, Richard L; Baik, Mu-Hyun; Schultz, Franklin A

    2007-04-01

    The manganese(III)-bis[poly(pyrazolyl)borate] complexes, Mn(pzb)2SbF6, where pzb- = tetrakis(pyrazolyl)borate (pzTp) (1), hydrotris(pyrazolyl)borate (Tp) (2), or hydrotris(3,5-dimethylpyrazolyl)borate (Tp*) (3), have been synthesized by oxidation of the corresponding Mn(pzb)2 compounds with NOSbF6. The Mn(III) complexes are low-spin in solution and the solid state (microeff = 2.9-3.8 microB). X-ray crystallography confirms their uncommon low-spin character. The close conformity of mean Mn-N distances of 1.974(4), 1.984(5), and 1.996(4) A in 1, 2, and 3, respectively, indicates absence of the characteristic Jahn-Teller distortion of a high-spin d4 center. N-Mn-N bite angles of slightly less than 90 degrees within the facially coordinated pzb- ligands produce a small trigonal distortion and effective D3d symmetry in 1 and 2. These angles increase to 90.0(4)degrees in 3, yielding an almost perfectly octahedral disposition of N donors in Mn(Tp*)2+. Examination of structural data from 23 metal-bis(pzb) complexes reveals systematic changes within the metal-(pyrazolyl)borate framework as the ligand is changed from pzTp to Tp to Tp*. These deformations consist of significant increases in M-N-N, N-B-N, and N-N-B angles and a minimal increase in Mn-N distance as a consequence of the steric demands of the 3-methyl groups. Less effective overlap of pyrazole lone pairs with metal atom orbitals resulting from the M-N-N angular displacement is suggested to contribute to the lower ligand field strength of Tp* complexes. Mn(pzb)2+ complexes undergo electrochemical reduction and oxidation in CH3CN. The electrochemical rate constant (ks,h) for reduction of t2g4 Mn(pzb)2+ to t2g3eg2 Mn(pzb)2 (a coupled electron-transfer and spin-crossover reaction) is 1-2 orders of magnitude smaller than that for oxidation of t2g4 Mn(pzb)2+ to t2g3 Mn(pzb)22+. ks,h values decrease as Tp* > pzTp > Tp for the Mn(pzb)2+/0 electrode reactions, which contrasts with the behavior of the comparable Fe(pzb)2

  19. Spectroscopic and ultrasonic investigations on structural characterization of borate glass specimen doped with transition metal ions.

    Science.gov (United States)

    Sathish, K; Thirumaran, S

    2015-08-01

    The present work describes the glass samples of composition (x% V₂O₅-(80-x)% B₂O₃-20% Na₂CO₃) VBS glass system and (x%MnO₂-(80-x)% B₂O₃-20% Na₂CO₃) in MBS glass system with mol% ranging from x=3, 6, 9, 12, 15 and 18 in steps of 3 mol% are prepared by melt quenching technique. For these prepared glass systems, sound velocity (longitudinal and shear velocities) and density have been measured. The sound velocity (longitudinal and shear) was measured by using pulse-echo technique at 5 MHz. The XRD study was carried to out to ascertain the amorphous nature of the glass specimen. Using these measured values, the elastic moduli, Poisson's ratio, Debye temperature, acoustic impedance and thermal expansion coefficient of the two glass systems were evaluated. The elastic and mechanical properties of the prepared glass systems are analyzed from ultrasonic study and the structural characterization from spectroscopic study. The effects due to the doping of transition metal ions with borate have been discussed. In the V₂O₅ doped glass system,(VBS glass system) the sound velocity, density and elastic moduli, steeply increases after 12 mol% comparatively with MnO₂ doped glass system (VBS glass system). The present study critically observes the doping of V₂O₅ with borate enhances the strengthening of network linkage and hardening of the glassy network structure than MnO₂. The IR spectral analysis reveals depolymerization of the borate network and conversion of BO₃ or BO4 units with the formation of non-bridging oxygen. The FTIR spectral studies confirm the presence of various functional groups of the sample. FTIR spectrum of sample exhibits broad absorption bands indicating the wide distribution of borate structural units. The effect of Na₂CO₃, V₂O₅ and MnO₂ contents on the structures of borate glass is evaluated from the FTIR spectra. The topological aspects of the prepared glass samples are exhaustively reported from SEM micrographs

  20. Spectroscopic and ultrasonic investigations on structural characterization of borate glass specimen doped with transition metal ions

    Science.gov (United States)

    Sathish, K.; Thirumaran, S.

    2015-08-01

    The present work describes the glass samples of composition (x% V2O5-(80-x)% B2O3-20% Na2CO3) VBS glass system and (x% MnO2-(80-x)% B2O3-20% Na2CO3) in MBS glass system with mol% ranging from x = 3, 6, 9, 12, 15 and 18 in steps of 3 mol% are prepared by melt quenching technique. For these prepared glass systems, sound velocity (longitudinal and shear velocities) and density have been measured. The sound velocity (longitudinal and shear) was measured by using pulse-echo technique at 5 MHz. The XRD study was carried to out to ascertain the amorphous nature of the glass specimen. Using these measured values, the elastic moduli, Poisson's ratio, Debye temperature, acoustic impedance and thermal expansion coefficient of the two glass systems were evaluated. The elastic and mechanical properties of the prepared glass systems are analyzed from ultrasonic study and the structural characterization from spectroscopic study. The effects due to the doping of transition metal ions with borate have been discussed. In the V2O5 doped glass system, (VBS glass system) the sound velocity, density and elastic moduli, steeply increases after 12 mol% comparatively with MnO2 doped glass system (VBS glass system). The present study critically observes the doping of V2O5 with borate enhances the strengthening of network linkage and hardening of the glassy network structure than MnO2. The IR spectral analysis reveals depolymerization of the borate network and conversion of BO3 or BO4 units with the formation of non-bridging oxygen. The FTIR spectral studies confirm the presence of various functional groups of the sample. FTIR spectrum of sample exhibits broad absorption bands indicating the wide distribution of borate structural units. The effect of Na2CO3, V2O5 and MnO2 contents on the structures of borate glass is evaluated from the FTIR spectra. The topological aspects of the prepared glass samples are exhaustively reported from SEM micrographs.

  1. Visualizing the Microdistribution of Zinc Borate in Oriented Strand Board Using X-Ray Microcomputed Tomography and SEM-EDX

    Directory of Open Access Journals (Sweden)

    Philip D. Evans

    2015-01-01

    Full Text Available Oriented strand board (OSB is an important wood composite used in situations where fungal decay and termite attack can occur. To counter these threats, powdered zinc borate biocide is commonly added to OSB. The effectiveness of biocides depends on their even distribution within composites and resistance to leaching, but little is known about the distribution of zinc borate in OSB. Zinc is denser than wood and it should be possible to map its distribution in OSB using X-ray micro-CT. We test this hypothesis and chemically register zinc in OSB using SEM-EDX. Zinc borate particles aggregated at the wood-adhesive interface in OSB, creating interrupted lines of zinc oriented in the x-y plane. Zinc borate particles were also found in the lumens of wood cells. Zinc was distributed throughout OSB, although slightly less was present in the core of the composite than in surface layers. A network of zinc remained in OSB after leaching in water. The resistance of zinc to leaching may be due to its incorporation in glue-lines within OSB, in addition to its low water-solubility. We conclude that X-ray micro-CT is a powerful tool for studying the distribution of zinc in OSB and other wood composites containing zinc borate.

  2. Investigations on the passivity of iron in borate and phosphate buffers, pH 8.4

    Energy Technology Data Exchange (ETDEWEB)

    Sieber, I.V. [University of Erlangen-Nuremberg, Department of Materials Science, Chair for Surface Science and Corrosion, D-91058 Erlangen (Germany)]. E-mail: irina.sieber@ww.uni-erlangen.de; Hildebrand, H. [University of Erlangen-Nuremberg, Department of Materials Science, Chair for Surface Science and Corrosion, D-91058 Erlangen (Germany); Virtanen, S. [University of Erlangen-Nuremberg, Department of Materials Science, Chair for Surface Science and Corrosion, D-91058 Erlangen (Germany); Schmuki, P. [University of Erlangen-Nuremberg, Department of Materials Science, Chair for Surface Science and Corrosion, D-91058 Erlangen (Germany)

    2006-11-15

    In the present work surface analytical experiments (XPS and AES) on the passive film on iron formed in borate and phosphate buffers (pH 8.4) have been carried out. In the passive film formed in phosphate buffer a significant amount of phosphates is found in the outer part of the film. Boron species are not significantly incorporated in the passive film formed in borate buffer. The mechanism of the reduction of the passive film depends strongly on the electrolyte composition. In borate buffer, cathodic polarization leads to reductive dissolution of the passive film whereas in phosphate buffer the passive film is converted into metallic iron without dissolution but via laterally inhomogeneously formation of an intermediate Fe(II) phosphate layer.

  3. Energy response of graphite-mixed magnesium borate TLDs to low energy x-rays

    DEFF Research Database (Denmark)

    Pelliccioni, M.; Prokic, M.; Esposito, A.;

    1991-01-01

    Graphite-mixed sintered magnesium borate TL dosemeters are attractive for beta/gamma dosimetry because they combine a low energy dependence to beta-rays with near tissue or air equivalence to photon irradiations and a high sensitivity. In this paper results from the experimental measurements...... of the energy response to very low energy x-rays are presented and evidence of agreement between experimental and calculated conversion coefficient H'(0.07, alpha = 0-degrees)/Ka is also shown. A monochromatized x-ray beam from a synchrotron radiation source in the energy range from 3 to 12 keV has been...

  4. Experience with certifying borated stainless steel as a shipping cask basket material

    Energy Technology Data Exchange (ETDEWEB)

    Abbott, D.G. (EG and G Idaho, Inc., Idaho Falls, ID (USA)); Nickell, R.E. (Applied Science and Technology, Inc., Poway, CA (USA))

    1990-01-01

    The original cask designs for a cask demonstration project featured fuel baskets constructed of borated stainless steel (bss) as a structural material. The project is intended to demonstrate casks that can be used for both shipping and storing spent nuclear fuel assemblies. The baskets were intended to maintain the fuel assemblies in a subcritical array for both normal and accident conditions. The Nuclear Regulatory Commission, however, judged bss to be unacceptable as a structural material. The cask designs were subsequently modified. The knowledge gained during this cask demonstration project may be applicable to development of bss as a basket material in future cask design. 6 refs., 2 figs., 2 tabs.

  5. Experience with certifying borated stainless steel as a shipping cask basket material

    Energy Technology Data Exchange (ETDEWEB)

    Abbott, D.G. [Idaho National Engineering Lab., Idaho Falls, ID (United States); Nickell, R.E. [Applied Science and Technology, Poway, CA (United States)

    1990-10-01

    This paper discusses the original cask designs for a cask demonstration project that has featured fuel baskets constructed of borated stainless steel (bss) as a structural material. The project is intended to demonstrate casks that can be used for both shipping and storing spent nuclear fuel assemblies. The baskets were intended to maintain the fuel assemblies in a subcritical array for both normal and accident conditions. The Nuclear Regulatory Commission, judged bss to be unacceptable as a structural material. The cask designs were subsequently modified. The knowledge gained during this cask demonstration project may be applicable to development of bss as a basket material in future cask design.

  6. Using a Borated Panel to Form a Dual Neutron-Gamma Detector

    Energy Technology Data Exchange (ETDEWEB)

    Scott Wilde; Raymond Keegan

    2008-06-20

    A borated polyethylene plane placed between a neutron source and a gamma spectrometer is used to form a dual neutron-gamma detection system. The polyethylene thermalizes the source neutrons so that they are captured by {sup 10}B to produce a flux of 478 keV gamma-rays that radiate from the plane. This results in a buildup of count rate in the detector over that from a disk of the same diameter as the detector crystal (same thickness as the panel). Radiation portal systems are a potential application of this technique.

  7. Cobalt tris(mercaptoimidazolyl)borate complexes: synthetic studies and the structure of the first cobaltaboratrane.

    Science.gov (United States)

    Mihalcik, David J; White, Jennifer L; Tanski, Joseph M; Zakharov, Lev N; Yap, Glenn P A; Incarvito, Christopher D; Rheingold, Arnold L; Rabinovich, Daniel

    2004-05-21

    The paramagnetic complexes (TmtBu)CoX (X = Cl, Br, I) have been readily prepared and structurally characterized and provide a convenient entry into cobalt(II) tris(mercaptoimidazolyl)borate chemistry. A number of derivatives, including mononuclear triphenylphosphine adducts [(TmtBu)Co(PPh3)]X and dinuclear compounds [Co2(TmtBu)2X]Y, have been prepared in order to ascertain whether cobalt is a reliable surrogate for zinc in biological systems, particularly in sulfur-rich coordination environments. The structure of the first cobaltaboratrane is also reported. PMID:15252613

  8. Effect of zinc borate on the thermal degradation of ammonium polyphosphate

    International Nuclear Information System (INIS)

    The thermal behaviour of a mixture containing an ammonium polyphosphate based compound (AP760) and zinc borate (ZB) is investigated. After an investigation of the degradation of the pure components, the interactions between them are examined by thermogravimetry. Then, X-ray diffraction (XRD) and 11B and 31P solid-state nuclear magnetic resonance (NMR) measurements have been carried out on residues of mixtures of AP760 and FBZB heat treated at different characteristic temperatures. It reveals the nature of the interactions taking place between the two components. It is demonstrated that reactions lead to the formation of zinc phosphate and of borophosphates. Mechanisms of thermal degradation are proposed

  9. Optical properties of Dy3+ doped bismuth zinc borate glass and glass ceramics

    Science.gov (United States)

    Shanmugavelu, B.; Kanth Kumar, V. V. Ravi

    2012-06-01

    Dy3+ doped bismuth zinc borate transparent glasses were prepared by melt quenching technique and these glasses were used precursor to obtain transparent glass ceramics by heat treatment method. XRD pattern of the glass ceramic shows the formation of the β-BiB3O6 and Bi2ZnOB2O6 phases. The visible emission intensity of the glass ceramics is stronger than the glass. This can be due to the formation of nano nonlinear optical crystallites in glass matrix.

  10. LaZnB(5)O(10), the first lanthanum zinc borate.

    Science.gov (United States)

    Jiao, Zhi-Wei; Wang, Ru-Ji; Wang, Xiao-Qing; Shen, De-Zhong; Shen, Guang-Qiu

    2009-01-01

    Lanthanum zinc penta-borate, LaZnB(5)O(10), was synthesized by flux-supported solid-state reaction. It is a member of the LnMB(5)O(10) (Ln = rare earth ion and M = divalent metal ion) structure type. The crystal shows a three-dimensional structure constructed from two-dimensional {[B(5)O(10)](5-)}(n) layers with the lanthanum (coordination number nine) and zinc (coordination number six) ions filling in the inter-layers. PMID:21579905

  11. Three-wave mixing mediated femtosecond pulse compression in β-barium borate.

    Science.gov (United States)

    Grün, A; Austin, Dane R; Cousin, Seth L; Biegert, J

    2015-10-15

    Nonlinear pulse compression mediated by three-wave mixing is demonstrated for ultrashort Ti:sapphire pulses in a type II phase-matched β-barium borate (BBO) crystal using noncollinear geometry. 170 μJ pulses at 800 nm with a pulse duration of 74 fs are compressed at their sum frequency to 32 fs with 55 μJ of pulse energy. Experiments and computer simulations demonstrate the potential of sum-frequency pulse compression to match the group velocities of the interacting waves to crystals that were initially not considered in the context of nonlinear pulse compression.

  12. Dispersive waves induced by self-defocusing temporal solitons in a beta-barium-borate crystal

    DEFF Research Database (Denmark)

    Zhou, Binbin; Bache, Morten

    2015-01-01

    We experimentally observe dispersive waves in the anomalous dispersion regime of a beta-barium-borate (BBO) crystal, induced by a self-defocusing few-cycle temporal soliton. Together the soliton and dispersive waves form an energetic octave-spanning supercontinuum. The soliton was excited...... in the normal dispersion regime of BBO through a negative cascaded quadratic nonlinearity. Using pump wavelengths from 1.24 to 1.4 μm, dispersive waves are found from 1.9 to 2.2 μm, agreeing well with calculated resonant phasematching wavelengths due to degenerate four-wave mixing to the soliton. We also...

  13. Thermal Stress-Induced Birefringence in Borate Glass Irradiated by Femtosecond Laser Pulses

    Institute of Scientific and Technical Information of China (English)

    DAI Ye; YU Bing-Kun; LU Bo; QIU Jian-Rong; YAN Xiao-Na; JIANG Xiong-Wei; ZHU Cong-Shan

    2005-01-01

    @@ Thermal stress-induced birefringence in borate glass which has been irradiated by 800-nm femtosecond laser pulses is observed under cross-polarized light. Due to the high temperature and pressure formed in the focal volume, the material at the edge of the micro-modified region is compressed between the expanding region and the unheated one, then stress emerges. Raman spectroscopy is used to investigate the stress distribution in the micro-modified region and indicates the redistributions of density and refractive index by Raman peak shift. We suggest that this technique can develop waveguide polarizers and Fresnel zone plates in integrated optics.

  14. SYNTHESIS, STRUCTURE AND SPECTRAL PROPERTIES OF POTASSIUMALUMINA- BORATE GLASS WITH NANOCRYSTALS OF MANGANESE FERRITE

    Directory of Open Access Journals (Sweden)

    D. I. Sobolev

    2016-07-01

    Full Text Available Subject of Research.The paper presents research results of optical properties of potassium-alumina-borate glass, activated with ions of iron and manganese. The formation process of nanocrystals of manganese ferrite MnFe2O4 in potassium-alumina-borate glass host was studied. Magneto-optical characteristics were analyzed. Method. The studied glasses were synthesized by the method of charge melting in the crucible. Potassium-alumina-borate glass system was used (K2O-Al2O3-B2O3 proposed by S.A. Stepanov (Vavilov State Institute. Glass system was doped by 3 wt% of Fe2O3 and 2 wt% MnO by weight (composition 1 and 2 wt% Fe2O3 and 1 wt% MnO by weight (composition 2. The glass transition temperature was 430 °C. Segregating of the crystal phase of manganese ferrite MnFe2O4 occurred during heat treatment at 550 °C for 2 hours in a programmable muffle furnace. The absorption spectrum in the wavelength range 200-2000 nm was recorded with Perkin Elmer Lambda 650 and Varian Cary 500 spectrophotometers. The XRD patterns were obtained on Rigaku Ultima IV X-ray diffractometer by copper anode with a wavelength λ (Cu = 0.15418 nm. Magneto-optical Verde constant was measured by the angle of polarization plane rotation of the passing light through the sample when the sample is placed in magnetic field. Main Results. New technological modes of potassium-alumina-borate glass synthesis doped with ions of iron and manganese were developed and studied. It is established that during heat treatment nanocrystals of manganese ferrites are evolved with an average size of 18 nm. These glasses have a Verde constant equal to 0.9 arc.min/(cm·Oe. It is shown that obtained glasses possess high absorbance in ultra-violet and visible light spectrum. Practical Relevance. Proposed and analyzed nanoglass-ceramics could be accepted as a basis for creation of sensing environments for sensors current and magnetic field and for creation of optical isolators based on the Faraday effect.

  15. Molecular dynamics simulations of silicate and borate glasses and melts : structure, diffusion dynamics and vibrational properties

    OpenAIRE

    Scherer, Christoph

    2015-01-01

    Molecular dynamics simulations of silicate and borate glasses and melts: Structure, diffusion dynamics and vibrational properties. In this work computer simulations of the model glass formers SiO2 and B2O3 are presented, using the techniques of classical molecular dynamics (MD) simulations and quantum mechanical calculations, based on density functional theory (DFT). The latter limits the system size to about 100−200 atoms. SiO2 and B2O3 are the two most important network formers for industri...

  16. Three-wave mixing mediated femtosecond pulse compression in β-barium borate.

    Science.gov (United States)

    Grün, A; Austin, Dane R; Cousin, Seth L; Biegert, J

    2015-10-15

    Nonlinear pulse compression mediated by three-wave mixing is demonstrated for ultrashort Ti:sapphire pulses in a type II phase-matched β-barium borate (BBO) crystal using noncollinear geometry. 170 μJ pulses at 800 nm with a pulse duration of 74 fs are compressed at their sum frequency to 32 fs with 55 μJ of pulse energy. Experiments and computer simulations demonstrate the potential of sum-frequency pulse compression to match the group velocities of the interacting waves to crystals that were initially not considered in the context of nonlinear pulse compression. PMID:26469593

  17. Optical spectroscopy of low-dimensional rare-earth iron borates

    Science.gov (United States)

    Popova, M. N.

    2009-04-01

    The family of RFe 3(BO 3) 4 borates (R=Pr, Nd, Eu-Er, Y) was studied by high-resolution optical absorption and Raman spectroscopies. Structural and magnetic phase transitions were detected and the types of magnetic structure were determined. Energy of crystal-field (CF) levels and exchange splitting of the ground state of the R 3+ ion were obtained from the analysis of optical spectra. CF calculations were carried out. Effective magnetic field at the R 3+ site was found, using the calculated value of the magnetic g-factor. Some peculiarities of modeling the paramagnetic susceptibility of NdFe 3(BO 3) 4 are discussed.

  18. Structural, optical and microhardness studies of pure and lanthanum doped ammonium penta borate (APB) single crystals

    International Nuclear Information System (INIS)

    Rare earth metal doped ammonium penta borate (MB) single crystals has been synthesized from slow solvent evaporation technique. The grown crystal has been subjected to single crystal X-ray diffraction analysis to identify the cell parameters and corresponding crystal system. The presence of lanthanum is confirmed by ICP analysis. The Kurtz's-Perry powder SHG efficiency was determined for both pure and lanthanum doped APB crystals as 1.6 and 2.2 times than that of pure KDP. The creation of weak lattice stress is confirmed by Vicker's microhardness test. (author)

  19. Visualizing the Microdistribution of Zinc Borate in Oriented Strand Board Using X-Ray Microcomputed Tomography and SEM-EDX

    OpenAIRE

    Evans, Philip D.; Vinicius Lube; Holger Averdunk; Ajay Limaye; Michael Turner; Andrew Kingston; Senden, Timothy J.

    2015-01-01

    Oriented strand board (OSB) is an important wood composite used in situations where fungal decay and termite attack can occur. To counter these threats, powdered zinc borate biocide is commonly added to OSB. The effectiveness of biocides depends on their even distribution within composites and resistance to leaching, but little is known about the distribution of zinc borate in OSB. Zinc is denser than wood and it should be possible to map its distribution in OSB using X-ray micro-CT. We test ...

  20. In vivo and in vitro studies of borate based glass micro-fibers for dermal repairing.

    Science.gov (United States)

    Zhou, Jie; Wang, Hui; Zhao, Shichang; Zhou, Nai; Li, Le; Huang, Wenhai; Wang, Deping; Zhang, Changqing

    2016-03-01

    Full-thickness skin defects represent urgent clinical problem nowadays. Wound dressing materials are hotly needed to induce dermal reconstruction or to treat serious skin defects. In this study, the borate bioactive glass (BG) micro-fibers were fabricated and compared with the traditional material 45S5 Bioglass(®) (SiG) micro-fibers. The morphology, biodegradation and bioactivity of BG and SiG micro-fibers were investigated in vitro. The wound size reduction and angiogenic effects of BG and SiG micro-fibers were evaluated by the rat full-thickness skin defect model and Microfil technique in vivo. Results indicated that the BG micro-fibers showed thinner fiber diameter (1 μm) and better bioactivity than the SiG micro-fibers did. The ionic extracts of BG and SiG micro-fibers were not toxic to human umbilical vein endothelial cells (HUVECs). In vivo, the BG micro-fiber wound dressings obviously enhanced the formation of blood vessel, and resulted in a much faster wound size reduction than the SiG micro-fibers, or than the control groups, after 9 days application. The good skin defect reconstruction ability of BG micro-fibers contributed to the B element in the composition, which results in the better bioactivity and angiogenesis. As shown above, the novel bioactive borate glass micro-fibers are expected to provide a promising therapeutic alternative for dermal reconstruction or skin defect repair.

  1. Durability and shielding performance of borated Ceramicrete coatings in beta and gamma radiation fields

    International Nuclear Information System (INIS)

    Highlights: • It incorporates all suggestions by the reviewers. • Explanation to each new term is provided and suitable references are given. • Sample identities have been streamlined by revising the text and the tables. • Some figures have been redrawn. - Abstract: Ceramicrete™, a chemically bonded phosphate ceramic, was developed for nuclear waste immobilization and nuclear radiation shielding. Ceramicrete products are fabricated by an acid–base reaction between magnesium oxide and mono potassium phosphate. Fillers are used to impart desired properties to the product. Ceramicrete’s tailored compositions have resulted in several commercial structural products, including corrosion- and fire-protection coatings. Their borated version, called Borobond™, has been studied for its neutron shielding capabilities and is being used in structures built for storage of nuclear materials. This investigation assesses the durability and shielding performance of borated Ceramicrete coatings when exposed to gamma and beta radiations to predict the composition needed for optimal shielding performance in a realistic nuclear radiation field. Investigations were conducted using experimental data coupled with predictive Monte Carlo computer model. The results show that it is possible to produce products for simultaneous shielding of all three types of nuclear radiations, viz., neutrons, gamma-, and beta-rays. Additionally, because sprayable Ceramicrete coatings exhibit excellent corrosion- and fire-protection characteristics on steel, this research also establishes an opportunity to produce thick coatings to enhance the shielding performance of corrosion and fire protection coatings for use in high radiation environment in nuclear industry

  2. Preparation of photoluminescent PMMA doped with tris(pyrazol-1-yl)borate lanthanide complexes

    Energy Technology Data Exchange (ETDEWEB)

    Bortoluzzi, Marco, E-mail: markos@unive.it [Dipartimento di Scienze Molecolari e Nanosistemi, Universita Ca' Foscari di Venezia, Dorsoduro 2137, 30123 Venezia (Italy); Paolucci, Gino, E-mail: paolucci@unive.it [Dipartimento di Scienze Molecolari e Nanosistemi, Universita Ca' Foscari di Venezia, Dorsoduro 2137, 30123 Venezia (Italy); Gatto, Mattia; Roppa, Stefania [Dipartimento di Scienze Molecolari e Nanosistemi, Universita Ca' Foscari di Venezia, Dorsoduro 2137, 30123 Venezia (Italy); Enrichi, Francesco [CIVEN, Coordinamento Interuniversitario Veneto per le Nanotecnologie, Via delle Industrie 5, 30175 Marghera (Venezia) (Italy); Ciorba, Serena; Richards, Bryce S. [School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS (United Kingdom)

    2012-09-15

    The neutral homoleptic Ln(III) complex Ln(Tp){sub 3} (Ln=Sm, Eu, Tb, Yb; Tp=hydrotris(pyrazol-1-yl)borate) were used as dopants for the preparation of novel photoluminescent poly(methyl methacrylate) glasses indicated as Ln(Tp){sub 3}-PMMA. The doped polymers containing samarium, europium and terbium derivatives showed emission associated to f-f transitions in the visible range upon excitation with UV light, while a NIR emission was obtained from Yb(Tp){sub 3}-PMMA. The maximum incident wavelength able to induce emissions from the Ln(Tp){sub 3}-doped polymers depends upon the choice of the lanthanide ion. No meaningful antenna-effect was instead observed using dysprosium as metal centre. - Highlights: Black-Right-Pointing-Pointer Polymers doped with photoluminescent lanthanide complexes. Black-Right-Pointing-Pointer Hydrotris(pyrazol-1-yl)borate (Tp) as antenna-ligand for Sm(III), Eu(III), Tb(III) and Yb(III). Black-Right-Pointing-Pointer Emission associated to f-f transitions upon excitation with UV light. Black-Right-Pointing-Pointer No antenna-effect for dysprosium derivative. Black-Right-Pointing-Pointer Photoluminescence excitation spectra are dependent upon the lanthanide ion.

  3. Effect of pH on the Electrochemical Behavior of Tantalum in Borate Buffer Solutions

    Science.gov (United States)

    Attarzadeh, F. R.; Attarzadeh, N.; Vafaeian, S.; Fattah-Alhosseini, A.

    2016-08-01

    In this research, various electrochemical methods were used to investigate the electrochemical behavior of tantalum in borate buffer solutions of various pH values, ranging from 9.0 to 6.5. Potentiodynamic polarization curves revealed that tantalum showed excellent passive behavior in borate buffer solutions. The potentiodynamic polarization and electrochemical impedance spectroscopy results showed that the passive film formed on tantalum offered its best protective behavior when the pH is 8.0, with the passivity undergoing a drastic change as the pH moved toward higher values. The semiconductive behavior of the passive films formed on tantalum was investigated by employing Mott-Schottky analysis in conjunction with a point defect model. The results indicated that the passive film exhibited n-type semiconductive behavior and that donor densities were in the range of 1.958-7.242 × 1020 cm-3. Moreover, this analysis showed that the donor density and flat band potential were quite sensitive to the pH.

  4. Durability and shielding performance of borated Ceramicrete coatings in beta and gamma radiation fields

    Science.gov (United States)

    Wagh, Arun S.; Sayenko, S. Yu.; Dovbnya, A. N.; Shkuropatenko, V. A.; Tarasov, R. V.; Rybka, A. V.; Zakharchenko, A. A.

    2015-07-01

    Ceramicrete™, a chemically bonded phosphate ceramic, was developed for nuclear waste immobilization and nuclear radiation shielding. Ceramicrete products are fabricated by an acid-base reaction between magnesium oxide and mono potassium phosphate. Fillers are used to impart desired properties to the product. Ceramicrete's tailored compositions have resulted in several commercial structural products, including corrosion- and fire-protection coatings. Their borated version, called Borobond™, has been studied for its neutron shielding capabilities and is being used in structures built for storage of nuclear materials. This investigation assesses the durability and shielding performance of borated Ceramicrete coatings when exposed to gamma and beta radiations to predict the composition needed for optimal shielding performance in a realistic nuclear radiation field. Investigations were conducted using experimental data coupled with predictive Monte Carlo computer model. The results show that it is possible to produce products for simultaneous shielding of all three types of nuclear radiations, viz., neutrons, gamma-, and beta-rays. Additionally, because sprayable Ceramicrete coatings exhibit excellent corrosion- and fire-protection characteristics on steel, this research also establishes an opportunity to produce thick coatings to enhance the shielding performance of corrosion and fire protection coatings for use in high radiation environment in nuclear industry.

  5. Effect of pH on the Electrochemical Behavior of Tantalum in Borate Buffer Solutions

    Science.gov (United States)

    Attarzadeh, F. R.; Attarzadeh, N.; Vafaeian, S.; Fattah-Alhosseini, A.

    2016-10-01

    In this research, various electrochemical methods were used to investigate the electrochemical behavior of tantalum in borate buffer solutions of various pH values, ranging from 9.0 to 6.5. Potentiodynamic polarization curves revealed that tantalum showed excellent passive behavior in borate buffer solutions. The potentiodynamic polarization and electrochemical impedance spectroscopy results showed that the passive film formed on tantalum offered its best protective behavior when the pH is 8.0, with the passivity undergoing a drastic change as the pH moved toward higher values. The semiconductive behavior of the passive films formed on tantalum was investigated by employing Mott-Schottky analysis in conjunction with a point defect model. The results indicated that the passive film exhibited n-type semiconductive behavior and that donor densities were in the range of 1.958-7.242 × 1020 cm-3. Moreover, this analysis showed that the donor density and flat band potential were quite sensitive to the pH.

  6. The structural, optical and magnetic parameter of manganese doped strontium zinc borate glasses

    International Nuclear Information System (INIS)

    Glasses with composition 10SrO:(30−x)ZnO:60B2O3:xMnO, 0≤x≤0.9 (all compositions in wt%) have been prepared and investigated by X-ray diffraction, EPR, Optical absorption and FT-IR spectroscopic techniques. The XRD pattern of all the glasses confirmed the formation of an amorphous structure. The EPR spectra of all glass samples exhibit resonance signals at g≈2.0 with a sextet of hyperfine lines. The spin concentration (N) and temperature dependence of EPR signals were studied for Mn2+ ions in strontium zinc borate glass samples. The zero-field splitting parameter D has been evaluated from the intensities of the allowed hyperfine lines. The paramagnetic susceptibility (χ) was calculated from EPR data at different temperatures and the Curie temperature (θp) was calculated from the 1/χ verses T graph. The optical absorption spectra exhibit a single broad band near 470 nm and this has been attributed to the spin-allowed 5Eg→5T2g transition of Mn3+ ions in octahedral symmetry. The theoretical optical basicity (Λth) of these glasses have also been evaluated. The FTIR studies show BO3 and BO4 structural units in strontium zinc borate glasses

  7. The structural, optical and magnetic parameter of manganese doped strontium zinc borate glasses

    Science.gov (United States)

    Sumalatha, B.; Omkaram, I.; Rajavardhana Rao, T.; Linga Raju, Ch.

    2013-02-01

    Glasses with composition 10SrO:(30-x)ZnO:60B2O3:xMnO, 0≤x≤0.9 (all compositions in wt%) have been prepared and investigated by X-ray diffraction, EPR, Optical absorption and FT-IR spectroscopic techniques. The XRD pattern of all the glasses confirmed the formation of an amorphous structure. The EPR spectra of all glass samples exhibit resonance signals at g≈2.0 with a sextet of hyperfine lines. The spin concentration (N) and temperature dependence of EPR signals were studied for Mn2+ ions in strontium zinc borate glass samples. The zero-field splitting parameter D has been evaluated from the intensities of the allowed hyperfine lines. The paramagnetic susceptibility (χ) was calculated from EPR data at different temperatures and the Curie temperature (θp) was calculated from the 1/χ verses T graph. The optical absorption spectra exhibit a single broad band near 470 nm and this has been attributed to the spin-allowed 5Eg→5T2g transition of Mn3+ ions in octahedral symmetry. The theoretical optical basicity (Λth) of these glasses have also been evaluated. The FTIR studies show BO3 and BO4 structural units in strontium zinc borate glasses.

  8. The structural, optical and magnetic parameter of manganese doped strontium zinc borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Sumalatha, B. [Department of Physics, Acharya Nagarjuna University, Guntur 522510, Andhra Pradesh (India); Omkaram, I. [Department of Physics, Sri Venkateswara University, Tirupati 517502, Andhra Pradesh (India); Rajavardhana Rao, T. [Department of Physics, Acharya Nagarjuna University, Guntur 522510, Andhra Pradesh (India); Linga Raju, Ch., E-mail: drchlraj_phy@yahoo.com [Department of Physics, Acharya Nagarjuna University, Guntur 522510, Andhra Pradesh (India)

    2013-02-15

    Glasses with composition 10SrO:(30−x)ZnO:60B{sub 2}O{sub 3}:xMnO, 0≤x≤0.9 (all compositions in wt%) have been prepared and investigated by X-ray diffraction, EPR, Optical absorption and FT-IR spectroscopic techniques. The XRD pattern of all the glasses confirmed the formation of an amorphous structure. The EPR spectra of all glass samples exhibit resonance signals at g≈2.0 with a sextet of hyperfine lines. The spin concentration (N) and temperature dependence of EPR signals were studied for Mn{sup 2+} ions in strontium zinc borate glass samples. The zero-field splitting parameter D has been evaluated from the intensities of the allowed hyperfine lines. The paramagnetic susceptibility (χ) was calculated from EPR data at different temperatures and the Curie temperature (θ{sub p}) was calculated from the 1/χ verses T graph. The optical absorption spectra exhibit a single broad band near 470 nm and this has been attributed to the spin-allowed {sup 5}E{sub g}→{sup 5}T{sub 2g} transition of Mn{sup 3+} ions in octahedral symmetry. The theoretical optical basicity (Λ{sub th}) of these glasses have also been evaluated. The FTIR studies show BO{sub 3} and BO{sub 4} structural units in strontium zinc borate glasses.

  9. Zinc containing borate glasses and glass-ceramics: Search for biomedical applications

    Directory of Open Access Journals (Sweden)

    Amr M. Abdelghany

    2014-12-01

    Full Text Available Ternary soda lime borate glass and samples with ZnO replacing CaO up to 10 mol% were prepared and studied for their bone bonding ability. Fourier transform infrared (FTIR absorption spectra of the prepared glasses before and after immersion in simulated body fluid (SBF, for one or two weeks, showed the appearance of calcium phosphate (hydroxyapatite (HA which is an indication of bone bonding ability. X-ray diffraction patterns were measured for the glasses and indicated the presence of small peaks related to hydroxyapatite in the samples immersed in SBF. The glasses were heat treated with controlled two-step regime to convert them to their corresponding glass-ceramic derivatives. FTIR and X-ray diffraction measurements of the glass-ceramic samples (before and after immersion in SBF confirmed the appearance of HA which is influenced by ZnO content. The overall data are explained on the basis of current views about the corrosion behaviour of borate glasses including hydrolysis and direct dissolution mechanism.

  10. Decomposition mechanism of melamine borate in pyrolytic and thermo-oxidative conditions

    Energy Technology Data Exchange (ETDEWEB)

    Hoffendahl, Carmen; Duquesne, Sophie; Fontaine, Gaëlle; Bourbigot, Serge, E-mail: serge.bourbigot@ensc-lille.fr

    2014-08-20

    Highlights: • Decomposition of melamine borate in pyrolytic and thermo-oxidative conditions was investigated. • With increasing temperature, orthoboric acid forms boron oxide releasing water. • Melamine decomposes evolving melamine, ammonia and other fragments. • Boron oxide is transformed into boron nitride and boron nitride-oxide structures through presence of ammonia. - Abstract: Decomposition mechanism of melamine borate (MB) in pyrolytic and thermo-oxidative conditions is investigated in the condensed and gas phases using solid state NMR ({sup 13}C and {sup 11}B), X-ray photoelectron spectroscopy (XPS), pyrolysis-gas chromatography–mass spectrometry (py-GCMS) and thermogravimetric analysis coupled with a Fourier transform infrared spectrometer (TGA–FTIR). It is evidenced that orthoboric acid dehydrates to metaboric and then to boron oxide. The melamine is partially sublimated. At the same time, melamine condensates, i.e., melem and melon are formed. Melon is only formed in thermo-oxidative conditions. At higher temperature, melem and melon decompose releasing ammonia which reacts with the boron oxide to form boron nitride (BN) and BNO structures.

  11. Mixed polaronic-ionic conduction in lithium borate glasses and glass-ceramics containing copper oxide

    Science.gov (United States)

    Khalil, M. M. I.

    2007-03-01

    The effect of electric field strength on conduction in lithium borate glasses doped with CuO with different concentration was studied and the value of the jump distance of charge carrier was calculated. The conductivity measurements indicate that the conduction is due to non-adiabatic hopping of polarons and the activation energies are found to be temperature and concentration dependent. Lithium borate glasses are subjected to carefully-programmed thermal treatments which cause the nucleation and growth of crystalline phases. X-ray diffraction analysis confirmed the amorphous nature for the investigated glass sample and the formation of crystalline phase for annealed samples at 650 °C. The main separated crystalline phase is Li2B8O13. The scanning electron micrographs of some selected glasses showed a significant change in the morphology of the films investigated due to heat treatment of the glass samples. It was found that the dc-conductivity decreases with an increase of the HT temperature. The decrease of dc conductivity, with an increase of the HT temperature, can be related to the decrease in the number of free ions in the glass matrix. There is deviation from linearity at high temperature regions in the logσ-1/T plots for all investigated doped samples at a certain temperature at which the transition from polaronic to ionic conduction occurs. The hopping of small polarons is dominant at low temperatures, whereas the hopping of Li+ ions dominates at high temperatures.

  12. Mixed polaronic-ionic conduction in lithium borate glasses and glass-ceramics containing copper oxide

    Energy Technology Data Exchange (ETDEWEB)

    Khalil, M.M.I. [National Center for Radiation Research and Technology, Radiation Physics Department, Cairo (Egypt)

    2007-03-15

    The effect of electric field strength on conduction in lithium borate glasses doped with CuO with different concentration was studied and the value of the jump distance of charge carrier was calculated. The conductivity measurements indicate that the conduction is due to non-adiabatic hopping of polarons and the activation energies are found to be temperature and concentration dependent. Lithium borate glasses are subjected to carefully-programmed thermal treatments which cause the nucleation and growth of crystalline phases. X-ray diffraction analysis confirmed the amorphous nature for the investigated glass sample and the formation of crystalline phase for annealed samples at 650 C. The main separated crystalline phase is Li{sub 2}B{sub 8}O{sub 13}. The scanning electron micrographs of some selected glasses showed a significant change in the morphology of the films investigated due to heat treatment of the glass samples. It was found that the dc-conductivity decreases with an increase of the HT temperature. The decrease of dc conductivity, with an increase of the HT temperature, can be related to the decrease in the number of free ions in the glass matrix. There is deviation from linearity at high temperature regions in the log{sigma}-1/T plots for all investigated doped samples at a certain temperature at which the transition from polaronic to ionic conduction occurs. The hopping of small polarons is dominant at low temperatures, whereas the hopping of Li{sup +} ions dominates at high temperatures. (orig.)

  13. Development of biomimetic coatings on Sm oxide doped ELB (Eu-Li-borate) glasses

    International Nuclear Information System (INIS)

    The in-vitro biomineralization of Eu/Li-borate glasses containing Sm2O3 was investigated by immersion in simulated body fluid (SBF) up to 72 h. Back scattering scanning electron microscope supplemented with EDX was used to follow the development of the phosphatic layer post 72 h SBF immersion. Biochemical analyses of calcium and inorganic phosphorus (Ca2+ and iP) ions were conducted using relevant biochemical kits and spectrophotometer. Spectra of TF-X-ray analyses and Fourier transform infrared were obtained for the samples post 72 h immersion and compared to the host one. The role of Sm2O3 in the biomineralization and crystallinity of the (ELB) borate glasses is proved by the developed rounded nano particles and the presence of elemental Eu and Sm in the formed layer beside Ca and P as presented by EDX. The continuous reduced values of ionic iP accompanying the adsorption and release of Ca ions in SBF with time assured the biolayer formation. The formed phosphatic layer presented shifted XRD peaks due to ionic incorporations especially of Sm3+. FT-IR proved the selectivity of BO3 group for phosphatic deposition. Deconvolution of ν4 and ν3 regions, for carbonates and phosphates, respectively, proved the enhanced peak areas with increased Sm3+ content.

  14. Durability and shielding performance of borated Ceramicrete coatings in beta and gamma radiation fields

    Energy Technology Data Exchange (ETDEWEB)

    Wagh, Arun S., E-mail: asw@anl.gov [Environmental Science Division, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439 (United States); Sayenko, S.Yu.; Dovbnya, A.N.; Shkuropatenko, V.A.; Tarasov, R.V.; Rybka, A.V.; Zakharchenko, A.A. [National Science Center, Kharkov Institute of Physics and Technology, Kharkov (Ukraine)

    2015-07-15

    Highlights: • It incorporates all suggestions by the reviewers. • Explanation to each new term is provided and suitable references are given. • Sample identities have been streamlined by revising the text and the tables. • Some figures have been redrawn. - Abstract: Ceramicrete™, a chemically bonded phosphate ceramic, was developed for nuclear waste immobilization and nuclear radiation shielding. Ceramicrete products are fabricated by an acid–base reaction between magnesium oxide and mono potassium phosphate. Fillers are used to impart desired properties to the product. Ceramicrete’s tailored compositions have resulted in several commercial structural products, including corrosion- and fire-protection coatings. Their borated version, called Borobond™, has been studied for its neutron shielding capabilities and is being used in structures built for storage of nuclear materials. This investigation assesses the durability and shielding performance of borated Ceramicrete coatings when exposed to gamma and beta radiations to predict the composition needed for optimal shielding performance in a realistic nuclear radiation field. Investigations were conducted using experimental data coupled with predictive Monte Carlo computer model. The results show that it is possible to produce products for simultaneous shielding of all three types of nuclear radiations, viz., neutrons, gamma-, and beta-rays. Additionally, because sprayable Ceramicrete coatings exhibit excellent corrosion- and fire-protection characteristics on steel, this research also establishes an opportunity to produce thick coatings to enhance the shielding performance of corrosion and fire protection coatings for use in high radiation environment in nuclear industry.

  15. Structures of potassium, sodium and lithium bis(oxalato)borate salts from powder diffraction data

    International Nuclear Information System (INIS)

    The crystal structures of the alkali-metal bis(oxalato)borate salts A[B(C2O4)2] (A = K, Na, Li) have been determined ab initio using powder diffraction data obtained from a laboratory diffractometer. The K compound crystallizes in the orthorhombic space group Cmcm and its structure has been solved by direct methods applied to the integrated intensities from full pattern decomposition. The Na compound is isostructural with the K salt, while the crystal structure of the highly hydroscopic Li compound differs from the other two. It has an orthorhombic lattice, space group Pnma, and its structure was solved by the global optimization method using a parallel tempering approach. In the K and Na structures the metal ions and complex borate ions form chains with m2m symmetry. Metal-oxygen bonding between the chains links them into a layer and then a framework with square tunnels. The coordination number of both K and Na is eight. The Li compound also contains chains that have.m. symmetry and are bound together into a three-dimensional framework. The coordination polyhedron of the Li atom is a square pyramid with Li lying in its base. This square pyramidal coordination leads to its high reactivity with moisture to give Li[B(C2O4)2]H2O with lithium in six coordination. (orig.)

  16. Luminescent borate glass for efficiency enhancement of CdTe solar cells

    International Nuclear Information System (INIS)

    Rare-earth (RE) doped borate glasses are investigated for their potential as photon down-shifting cover glass for CdTe solar cells. The barium borate base glass is doped with trivalent rare-earth ions such as Sm3+, Eu3+, and Tb3+ showing an intense luminescence in the red (Sm3+, Eu3+) and green (Tb3+) spectral range upon excitation in the ultraviolet and blue. Additionally, the glasses are double-doped with two RE ions for a broad-band absorption. The gain in short-circuit current density of CdTe solar cells with different thicknesses of the CdS buffer layer is calculated. Though the single-doped glasses already reveal a slight increase in short-circuit current density, the double-doped glasses allow for higher efficiency gains since a significant broader spectral range is covered for absorption. For a Tb3+/Eu3+ double-doped glass with a RE doping level of 1 at% each, an efficiency increase of 1.32% can be achieved. - Highlights: • Rare-earth doped front glass for high efficiency CdTe solar cells were prepared. • Double-doping allows for higher efficiency gains than single-doping. • Efficiency enhancement of 1.32% can be achieved with Tb3+/Eu3+ doped front glass

  17. Optical and Physical Properties of Bismuth Borate Glasses Doped With Dy3+

    Directory of Open Access Journals (Sweden)

    P. Limsuwan

    2011-01-01

    Full Text Available This study reports on physical and optical properties of Dy3+ doped bismuth borate glass. The glasses containing Dy3+ in (70-xB2O3:30Bi2O3:xDy2O3 (where x = 0.0-2.5 mol% have been prepared by melt-quenching method. In order to understand the role of Dy2O3 in these glasses, the density, molar volume and optical spectra were investigated. The results show that molar volume of the glasses increase with the increasing of Dy2O3 concentration and consequently generating more non-bridging oxygen (NBOs into glass matrix. The absorption spectra of Dy3+ doped in bismuth borate glass correspond with several bands, which are assigned from the ground state, 6H15/2 to 6F3/2(761 nm, 6F5/2(806 nm, 6F7/2(907 nm, (6H7/2, 6F9/2(1099 nm, (6F11/2, 6H9/2 (1283 nm and 6H11/2(1695 nm. Moreover, the optical basicities were also theoretically determined.

  18. Inorganic pigments doped with tris(pyrazol-1-yl)borate lanthanide complexes: A photoluminescence study

    International Nuclear Information System (INIS)

    The inorganic pigments malachite, Egyptian blue, Ercolano blue and chrome yellow have been doped with the neutral homoleptic Ln(III) complex Ln(Tp)3 (Ln=Eu, Tb; Tp=hydrotris(pyrazol-1-yl)borate) in the presence of arabic gum or acrylic emulsion as binders, in order to obtain photoluminescent materials of interest for cultural heritage restoration. The doped pigments have shown emissions associated to f–f transitions in the visible range upon excitation with UV light. Thermal and UV-light ageings have been carried out. In all the cases the photoluminescent behaviour is maintained, but in the cases of acrylic-based paints emission spectra and lifetimes are strongly influenced by thermal treatments. The choice of binder and pigments influences the photoluminescent behaviour of the corresponding film paints. -- Highlights: • Inorganic pigments doped with photoluminescent lanthanide complexes. • Hydrotris(pyrazol-1-yl)borate (Tp) as antenna-ligand for Eu(III) and Tb(III). • Emission associated to f–f transitions upon excitation with UV light. • Photoluminescence of paints influenced by the choice of binder and pigments. • Photoluminescence after ageing depending upon the type of binder

  19. Conversion of borate-based glass scaffold to hydroxyapatite in a dilute phosphate solution.

    Science.gov (United States)

    Liu, Xin; Pan, Haobo; Fu, Hailuo; Fu, Qiang; Rahaman, Mohamed N; Huang, Wenhai

    2010-02-01

    Porous scaffolds of a borate-based glass (composition in mol%: 6Na2O, 8K2O, 8MgO, 22CaO, 36B2O3, 18SiO2, 2P2O5), with interconnected porosity of approximately 70% and pores of size 200-500 microm, were prepared by a polymer foam replication technique. The degradation of the scaffolds and conversion to a hydroxyapatite-type material in a 0.02 M K2HPO4 solution (starting pH = 7.0) at 37 degrees C were studied by measuring the weight loss of the scaffolds, as well as the pH and the boron concentration of the solution. X-ray diffraction, scanning electronic microscopy and energy dispersive x-ray analysis showed that a hydroxyapatite-type material was formed on the glass surface within 7 days of immersion in the phosphate solution. Cellular response to the scaffolds was assessed using murine MLO-A5 cells, an osteogenic cell line. Scanning electron microscopy showed that the scaffolds supported cell attachment and proliferation during the 6 day incubation. The results indicate that this borate-based glass could provide a promising degradable scaffold material for bone tissue engineering applications. PMID:20057014

  20. Conversion of borate-based glass scaffold to hydroxyapatite in a dilute phosphate solution

    Energy Technology Data Exchange (ETDEWEB)

    Liu Xin; Huang Wenhai [Institute of Bioengineering and Information Technology Materials, Tongji University, Shanghai 200092 (China); Pan Haobo [Department of Orthopaedics and Traumatology, University of Hong Kong, 999077 (Hong Kong); Fu Hailuo; Fu Qiang; Rahaman, Mohamed N, E-mail: tsliuxin@hotmail.co, E-mail: whhuang@tongji.edu.c [Department of Materials Science and Engineering, and Center for Bone and Tissue Repair and Regeneration, Missouri University of Science and Technology, MO 65409 (United States)

    2010-02-15

    Porous scaffolds of a borate-based glass (composition in mol%: 6Na{sub 2}O, 8K{sub 2}O, 8MgO, 22CaO, 36B{sub 2}O{sub 3}, 18SiO{sub 2}, 2P{sub 2}O{sub 5}), with interconnected porosity of {approx}70% and pores of size 200-500{mu}m, were prepared by a polymer foam replication technique. The degradation of the scaffolds and conversion to a hydroxyapatite-type material in a 0.02 M K{sub 2}HPO{sub 4} solution (starting pH = 7.0) at 37 deg. C were studied by measuring the weight loss of the scaffolds, as well as the pH and the boron concentration of the solution. X-ray diffraction, scanning electronic microscopy and energy dispersive x-ray analysis showed that a hydroxyapatite-type material was formed on the glass surface within 7 days of immersion in the phosphate solution. Cellular response to the scaffolds was assessed using murine MLO-A5 cells, an osteogenic cell line. Scanning electron microscopy showed that the scaffolds supported cell attachment and proliferation during the 6 day incubation. The results indicate that this borate-based glass could provide a promising degradable scaffold material for bone tissue engineering applications.

  1. Effect of copper oxide on structure and physical properties of lithium lead borate glasses

    Science.gov (United States)

    Kashif, I.; Ratep, A.

    2015-09-01

    Copper-doped Lead lithium borate glass samples with the composition of (35- x) Pb3O4- xCuO-65Li2B4O7, where x = 5, 10, 15 or 20 mol%, have been prepared by melt quenching technique. Glass-forming ability, density, electrical conductivity, magnetic susceptibility and structural properties of lead lithium borate glasses have been investigated. IR spectroscopic data show that the copper ions play the role of glass modifier. Addition of CuO influences BO3 ↔ BO4 conversion. Density is expressed in terms of the structural modifications that take place in glass matrix. The increase in Tg reflects an increase in bond strength, and samples obtain more rigid glass structure. Electrical conductivity and magnetic susceptibility χ data show a variable behavior with the increase in the copper content in two valance states Cu+ and Cu+2. In addition, optical properties depend on the change of the role of copper ions in the samples' structure. Optical energy band gap E opt and Urbach energy E tail are determined. The increase in E opt and UV cutoff with an increase in CuO content is due to the decrease in non-bridging oxygen concentration. The decrease in E tail at higher concentrations is attributed to the copper ion accumulation in the interstitial positions and to the formation of orthoborate groups. These samples are suitable for the green light longpass filters.

  2. Moessbauer study of the fraction of non-bridging oxygens in potassium borate glasses

    International Nuclear Information System (INIS)

    A Moessbauer study was performed to find the fraction of non-bridging oxygens in potassium borate glasses containing a small amount of iron. The borate glasses with alkali contents of 15, 20, 25, 30 and 40 mol% were irradiated with 60Co-γ rays at room temperature in a nitrogen atmosphere. The Moessbauer absorption area for the irradiation-induced Fe2+ increased with the total γ-ray dose in the range of 1 x 106 - 2 x 108 R, and became constant after irradiation ranging from 2 x 108 R - 1 x 109 R. The absorption area for the Fe2+ at the saturated region was correlated with the difference in the glass structure, i.e., the fraction of the non-bridging oxygens was estimated from the increased absorption area for the Fe2+ as a function of the alkali content of the glasses. The fraction of the non-bridging oxygen increased with the alkali content of the glasses in the alkali region above 20 mol%, and about 14% of the fraction was obtained for an alkali content of 40 mol%. (orig.)

  3. Luminescent borate glass for efficiency enhancement of CdTe solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Steudel, Franziska, E-mail: franziska.steudel@iwmh.fraunhofer.de [Fraunhofer Application Center for Inorganic Phosphors, Branch Lab of Fraunhofer Institute for Mechanics of Materials IWM, Lübecker Ring 2, 59494 Soest (Germany); Loos, Sebastian [Department of Electrical Engineering, South Westphalia University of Applied Sciences, Lübecker Ring 2, 59494 Soest (Germany); Ahrens, Bernd; Schweizer, Stefan [Fraunhofer Application Center for Inorganic Phosphors, Branch Lab of Fraunhofer Institute for Mechanics of Materials IWM, Lübecker Ring 2, 59494 Soest (Germany); Department of Electrical Engineering, South Westphalia University of Applied Sciences, Lübecker Ring 2, 59494 Soest (Germany)

    2015-08-15

    Rare-earth (RE) doped borate glasses are investigated for their potential as photon down-shifting cover glass for CdTe solar cells. The barium borate base glass is doped with trivalent rare-earth ions such as Sm{sup 3+}, Eu{sup 3+}, and Tb{sup 3+} showing an intense luminescence in the red (Sm{sup 3+}, Eu{sup 3+}) and green (Tb{sup 3+}) spectral range upon excitation in the ultraviolet and blue. Additionally, the glasses are double-doped with two RE ions for a broad-band absorption. The gain in short-circuit current density of CdTe solar cells with different thicknesses of the CdS buffer layer is calculated. Though the single-doped glasses already reveal a slight increase in short-circuit current density, the double-doped glasses allow for higher efficiency gains since a significant broader spectral range is covered for absorption. For a Tb{sup 3+}/Eu{sup 3+} double-doped glass with a RE doping level of 1 at% each, an efficiency increase of 1.32% can be achieved. - Highlights: • Rare-earth doped front glass for high efficiency CdTe solar cells were prepared. • Double-doping allows for higher efficiency gains than single-doping. • Efficiency enhancement of 1.32% can be achieved with Tb{sup 3+}/Eu{sup 3+} doped front glass.

  4. Enhanced ionic conductivity in borate ester plasticized Polyacrylonitrile electrolytes for lithium battery application

    International Nuclear Information System (INIS)

    The effect of low molecular weight borate ester on the ionic conductivity of polyacrylonitrile (PAN) was systematically investigated by means of measuring conductivity using the impedance technique. Gel polymer electrolyte (SPE) films consisting of PAN as host polymer, LiCF3SO3 and LiBF4 as ionic salts, and poly (ethylene glycol) borate ester (PEGB), ethylene carbonate/propylene carbonate (EC/PC) as plasticizers were prepared by physical blending method. All measurements were performed on electrolyte samples with various contents. Fourier transform infrared spectroscopy (FT-IR) gave evidence of the interactions among PAN, plasticizers and lithium salt. The surface morphology of the electrolytes was investigated by scanning electron microscopy (SEM). Thermal properties of these materials were searched with thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Conductivity studies of these blend polymer electrolytes were carried out in the temperature range 20–100 °C. The maximum ionic conductivity values of 1.8 × 10−3 and 1.4 × 10−4 S cm−1 were measured for the film containing 4PAN-10EC/PC-4LiBF4 and 4PAN-10PEGB-4LiCF3SO3, respectively, at room temperature. These films have a good conductivity, better dimensional stability and wide electrochemical stability window. These unique properties make the composite gel membranes suitable for application as electrolyte in rechargeable Li-ion batteries

  5. Mixed alkali effect on the spectroscopic properties of alkali-alkaline earth oxide borate glasses

    Science.gov (United States)

    Srinivas, G.; Ramesh, B.; Shareefuddin, Md.; Chary, M. N.; Sayanna, R.

    2016-05-01

    The mixed alkali and alkaline earth oxide borate glass with the composition xK2O - (25-x) Li2O-12.5BaO-12.5MgO-50B2O3 (x = 0, 5, 10, 15, 20 and 25mol %) and doped with 1mol% CuO were prepared by the melt quenching technique. From the optical absorption spectra the optical band gap, electronic polarizability(α02-), interaction parameter (A), theoretical and experimental optical basicity (Λ) values were evaluated. From the Electron Paramagnetic Resonance (EPR) spectral data the number of spins (N) and susceptibility (χ) were evaluated. The values of (α02-), and (Λ) increases with increasing of K2O content and electronic polarizability and interaction parameter show opposite behaviuor which may be due to the creation of non-bridging oxygens and expansion of borate network. The reciprocal of susceptibility (1/χ) and spin concentration (N) as a function of K2O content, varied nonlinearly which may be due to creation of non-bridging oxygens in the present glass system. This may be attributed to mixed alkali effect (MAE).

  6. Synthesis and characterization of borate based and AgGaS{sub 2} materials

    Energy Technology Data Exchange (ETDEWEB)

    Dhanasekaran, R, E-mail: rdhanasekaran@annauniv.edu [Crystal Growth Centre, Anna University-Chennai, Chennai 600 025 (India)

    2009-07-15

    In recent years, there has been tremendous development in the fabrication of suitable materials for optoelectronic, laser, photovoltaic devices, acousto-optic, sonar and infrared detectors applications. Mastering in synthesis, growth and characterization is an essential requirement for fully realizing the potential applications of the materials technology for the construction of novel devices for Laser, microwave, optoelectronic and other applications. The anisotropy in the crystals gives them enhanced properties as required in the field of non-linear optics. With the advent of laser sources, a nonlinear optical phenomenon has got tremendous interest and nonlinear optical (NLO) materials play a key role in the development of laser technology. Because of the variety and complexity of the material systems involved, several approaches towards synthesis, growth and characterization have been developed during the past decades. Laser materials can be classified into Inorganic, Organic and Semi organic categories. Urea, DAST, mNA, POM, NPP, MAP are examples of organic family crystals where as L-Arginine phosphate (LAP), Zinc tris thiourea sulphate (ZTS), BTCC, ZCTC belongs to semi organic class. Inorganic NLO crystals are Potassium titanyl phosphate (KTP), GdYCOB, KAB, Beta Barium Borate (BBO), LBO, KDP and LiNbO{sub 3}. Synthesis and characterization of technologically important Borate based materials for NLO applications will be reviewed. The raising demand for UV lasers has led to the development of various NLO materials. A series of borate materials - Rare earth calcium oxy borate (RECOB) with the general chemical formula RECa{sub 4}O(BO{sub 3}){sub 3} with RE=Y,Gd, Nd, Sm, etc. are reported to be synthesized from their repective melts. The RECOB crystals are excellent NLO materials and when doped with 'laser-active' ions (Nd{sup 3+}, Yb{sup 3+}), they become efficient laser-host crystals. The single crystals of YCOB were grown by flux technique using boron

  7. Improved green-light-emitting pyrotechnic formulations based on tris(2,2,2-trinitroethyl)borate and boron carbide.

    Science.gov (United States)

    Klapötke, Thomas M; Krumm, Burkhard; Rusan, Magdalena; Sabatini, Jesse J

    2014-08-28

    Green-light-emitting pyrotechnic compositions based on tris(2,2,2-trinitroethyl)borate (TNEB) and boron carbide have been investigated. The best performing formulations were found to be insensitive to various ignition stimuli, and exhibited very high spectral purities and luminosities compared to previously reported green-light-emitting formulations.

  8. Synthesis and vibrational circular dichroism of enantiopure chiral oxorhenium(V) complexes containing the hydrotris(1-pyrazolyl)borate ligand

    DEFF Research Database (Denmark)

    Lassen, Peter Rygaard

    2006-01-01

    The infrared and vibrational circular dichroism (VCD) spectra of six chiral oxorhenium(V) complexes, bearing a hydrotris(1-pyrazolyl)borate (Tp) ligand, have been investigated. These complexes are promising candidates for observation of parity violation (symmetry breaking due to the weak nuclear ...

  9. The Tribological Chemistry of a Novel Borate Ester Additive and Its Interaction with ZDDP Using XANES and XPS

    NARCIS (Netherlands)

    Zhang, Yawen; Zeng, Xiangqiong; Wu, Hua; Li, Zhipeng; Ren, Tianhui; Zhao, Yidong

    2014-01-01

    A novel borate ester containing heterocyclic group, 2,5-bis((2-((6-octadecyl-1,3,6,-dioxazaborocan-2-yl)oxy)propyl)thio)-1,3,4-thiadiazole (BDOT), was prepared and characterized. Its tribological properties and synergistic effect with zinc dialkyl dithiophosphate were evaluated using a four-ball tri

  10. Local structure of alkalis in mixed-alkali borate glass to elucidate the origin of mixed-alkali effect

    Directory of Open Access Journals (Sweden)

    Yomei Tokuda

    2015-12-01

    Full Text Available We report the structural analysis of Na+ and Cs+ in sodium cesium borate crystals and glasses using 23Na and 133Cs magic-angle spinning nuclear magnetic resonance (MAS NMR spectroscopy. The composition dependence of NMR spectra of the borate was similar to that of the silicate: (1 the peak position of cesium borate crystals shifted to upfield for structures with larger Cs+ coordination numbers, (2 the MAS NMR spectra of xNa2O-yCs2O-3B2O3 (x = 0, 0.25, 0.5, 0.75, 1.0, x + y = 1 glass showed that the average coordination number (CN of both the alkali cations decreases with increasing Cs+/(Na+ + Cs+ ratio. However, the degree of decrement in borates is much smaller than that in silicates. We have considered that the small difference in CN is due to 4-coordinated B, because it is electrically compensated by the alkali metal ions resulting in the restriction of having various coordinations of O to alkali metal.

  11. Synthesis and characterization of cerium- and gallium-containing borate bioactive glass scaffolds for bone tissue engineering.

    Science.gov (United States)

    Deliormanlı, Aylin M

    2015-02-01

    Bioactive glasses are widely used in biomedical applications due to their ability to bond to bone and even to soft tissues. In this study, borate based (13-93B3) bioactive glass powders containing up to 5 wt% Ce2O3 and Ga2O3 were prepared by the melt quench technique. Cerium (Ce+3) and gallium (Ga+3) were chosen because of their low toxicity associated with bacteriostatic properties. Bioactive glass scaffolds were fabricated using the polymer foam replication method. In vitro degradation and bioactivity of the scaffolds were evaluated in SBF under static conditions. Results revealed that the cerium- and gallium-containing borate glasses have much lower degradation rates compared to the bare borate glass 13-93B3. In spite of the increased chemical durability, substituted glasses exhibited a good in vitro bioactive response except when the Ce2O3 content was 5 wt%. Taking into account the high in vitro hydroxyapatite forming ability, borate glass scaffolds containing Ce+3 and Ga+3 therapeutic ions are promising candidates for bone tissue engineering applications. PMID:25631259

  12. Study of neodymium oxide inclusion on the structure of a borate glass

    International Nuclear Information System (INIS)

    The structure of borate glass has been well studied by many different authors using a variety of techniques. When other compounds are added to the glass which accommodates them, the structural environment of the inclusions will depend on the type of included elements. Given the large number of applications of borate glasses, a study of the factors that determine the surrounding structure of an included ion in a glass is thus of much relevance. As a first step in such studies, a single ion-type viz. neodymium oxide ( Nd2O3 ) was incorporated in a borate host glass at varying mole percentages of the dopant from 10% to 25%. These glasses were melt-quenched in air from 1450 oC. Transparent bubble-free purple glass beads were obtained and subsequently crushed into fine powders for the X-ray and neutron diffraction measurements. The glass transition temperature was approximately 750 oC. An incident wavelength of 1.54 Å ( CuKα ) was used in the X-ray diffraction studies. Neutron diffraction measurements were made on the High Q diffractometer at Dhruva Reactor, B.A.R.C., Mumbai in the Q range of 0.3 to 15 Å-1 . The diffraction patterns from both techniques showed some trends with concentration in the higher Q regions of S(Q). The real space correlation functions viz. T(r) and number density function N(r) gave clear indications of changes of nearestneighbour coordination number of O around B (at 1.366 Å) as a function of Nd2O3 molar concentration in the glass. Thus in the first peak, the fraction due to tetrahedral BO4 units increases from 28% to 41% with dopant level at the expense of BO3 triangles. From an analysis of the second peak in T(r), super-structural units such as diborate and di-pentaborate units surround the Nd ion at lower dopant levels while the coordination is octahedral at higher levels of dopant. These findings are in keeping with a model that the overall structure of the host glass is affected by the concentration of the dopant ion.

  13. Generation of ultraviolet radiation with wide angular tolerance in cesium lithium borate crystal

    Indian Academy of Sciences (India)

    Gopal C Bhar; Pathik Kumbhakar; Anil K Chaudhary

    2000-09-01

    Tangential phase-matching has been realised in cesium lithium borate (CLBO) crystal for the first time for the generation of fourth harmonic (266 nm) of Nd:YAG and third harmonic (226.7 nm) of a dye laser radiation by second harmonic generation and sum-frequency mixing with the angular tolerance as large as 22 mrad and 21 mrad respectively, over one of the interacting beams. An energy conversion efficiency of 15% for fourth harmonic generation is obtained with a 5.5 mm thick crystal and with the average pump powers only 170 and 70 mW. A set of Sellmeier dispersion equations for the CLBO crystal have also been formulated.

  14. Production and characterization of hydrophobic zinc borate by using palm oil

    Institute of Scientific and Technical Information of China (English)

    Nil Baran Acarali; Nurcan Tugrul; Emek Moroydor Derun; Sabriye Piskin

    2013-01-01

    Zinc borate (ZB) was synthesized using zinc oxide, boric acid synthesized from colemanite, and reference ZB as seed. The eff ects of reaction parameters such as reaction time, reactant ratio, and seed ratio on its yield were examined. Then, the eff ects of palm oil with solvents (isopropyl alcohol (IPA), ethanol, and methanol) added to the reaction on its hydrophobicity were explored. Reactions were carried out under determined reaction conditions with magnetically and mechanically stirred systems. The produced ZB was characterized by X-ray diff raction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and measurements of contact angle identified hydrophobicity. The results showed that hydrophobic ZB was successfully produced under determined reaction conditions. The change of process parameters influenced its yield and the usage of palm oil provided hydrophobicity.

  15. Effect of beam oscillation on borated stainless steel electron beam welds

    International Nuclear Information System (INIS)

    Borated stainless steels are used in nuclear power plants to control neutron criticality in reactors as control rods, shielding material, spent fuel storage racks and transportation casks. In this study, bead on plate welds were made using gas tungsten arc welding (GTAW) and electron beam welding (EBW) processes. Electron beam welds made using beam oscillation technique exhibited higher tensile strength values compared to that of GTA welds. Electron beam welds were found to show fine dendritic microstructure while GTA welds exhibited larger dendrites. While both processes produced defect free welds, GTA welds are marked by partially melted zone (PMZ) where the hardness is low. EBW obviate the PMZ failure due to low heat input and in case of high heat input GTA welding process failure occurs in the PMZ.

  16. Synthesis and Crystal Structure of Borate Oxide Co3BO5

    Institute of Scientific and Technical Information of China (English)

    张浩; 程文旦; 黄子祥

    2001-01-01

    A mix-charge cation solid-state borate oxide Co3BO5 has beensynthesized and its structure has been determined by single-crystal X-ray methods. It crystallizes in the orthorhombic~space group Pbam with cell parameters a=9.2963(2), b=11.948(2), c=2.9737(6) Å, V=330.30(12)Å3, Z=4, Mr=267.60, F(000)=504, μ=14.733, Dcalcd=5.381g/cm3. The structure was determined from 853 unique reflections and refined to the final residuals R=0.0633 and wR=0.1457. It has two kinds of Co cations, Co2+ and Co3+. It is composed of highly distorted [CoO4] squares and triangular [BO3] groups that are connected to form infinite two-dimensional layers.

  17. Structural, dielectric and AC conductivity properties of Co2+ doped mixed alkali zinc borate glasses

    Science.gov (United States)

    Madhu, B. J.; Banu, Syed Asma; Harshitha, G. A.; Shilpa, T. M.; Shruthi, B.

    2013-02-01

    The Co2+ doped 19.9ZnO+5Li2CO3+25Na2CO3+50B2O3 (ZLNB) mixed alkali zinc borate glasses have been prepared by a conventional melt quenching method. The structural (XRD & FT-IR), dielectric and a.c. conductivity (σac) properties have been investigated. Amorphous nature of these glasses has been confirmed from their XRD pattern. The dielectric properties and electrical conductivity (σac) of these glasses have been studied from 100Hz to 5MHz at the room temperature. Based on the observed trends in the a.c. conductivities, the present glass samples are found to exhibit a non-Debye behavior.

  18. Method of volume-reducing for radioactive sodium borate liquid wastes and its device

    International Nuclear Information System (INIS)

    Purpose: To easily obtain glass solidification products with efficient volume-reducing effect and high water-proofness from liquid wastes discharged from PWR type reactors. Method: Sodium borate liquid wastes pre-condensated and adjusted to pH 8 - 9 are incorporated with ZnO (or inorganic ZnO compound being capable of converting into ZnO after melting) or a mixture of ZnO with Al2O3 or CaO, irradiated by microwaves into glass solidification products (B2O3-Na2O-ZnO). The molar ratio of Na2O to B2O3 contained in liquid wastes is adjusted to between 0.1 - 0.6. The ZnO content is set to 10 - 40 mol%. (Ikeda, J.)

  19. Wavelength interdependence assessment of all-optical switching in zinc borate glasses

    Science.gov (United States)

    Abdel-Baki, Manal; Abdel-Wahab, Fathy; El-Diasty, Fouad

    2012-08-01

    Lithium tungsten borate photonic glass is prepared by the conventional melt-quench technique. Due to semiconductor-like behavior of zinc oxide, the glass is doped by ZnO to adapt its optical nonlinearity. Fresnel-based spectrophotometric measurements and Lorentz dispersion theory are applied to study (in a very wide range of photon energy from 0.5 to 6.2 eV) the dispersion of second-order refractive index, two-photon absorption coefficient, and third-order optical susceptibility of the glass. The figure of merit (FOM) needed for optical switching applications is estimated. We reveal the importance of determining the dispersion of the optical nonlinear parameters to find out the appropriate operating wavelength for optimum FOM of the glass.

  20. Production and characterization of hydrophobic zinc borate by using palm oil

    Science.gov (United States)

    Acarali, Nil Baran; Tugrul, Nurcan; Derun, Emek Moroydor; Piskin, Sabriye

    2013-11-01

    Zinc borate (ZB) was synthesized using zinc oxide, boric acid synthesized from colemanite, and reference ZB as seed. The effects of reaction parameters such as reaction time, reactant ratio, and seed ratio on its yield were examined. Then, the effects of palm oil with solvents (isopropyl alcohol (IPA), ethanol, and methanol) added to the reaction on its hydrophobicity were explored. Reactions were carried out under determined reaction conditions with magnetically and mechanically stirred systems. The produced ZB was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and measurements of contact angle identified hydrophobicity. The results showed that hydrophobic ZB was successfully produced under determined reaction conditions. The change of process parameters influenced its yield and the usage of palm oil provided hydrophobicity.

  1. Electrochemical passivation behaviour of nanocrystalline Fe80Si20 coating in borate buffer solution

    Indian Academy of Sciences (India)

    G Gupta; A P Moon; K Mondal

    2013-02-01

    Passivation behaviour of nanocrystalline coating (Fe80Si20) obtained by in situ mechanical alloying route is studied and compared with that of the commercial pure iron and cast Fe80Si20 in sodium borate buffer solution at two different pH values (7.7 and 8.4). The coating reveals single passivation at a pH of 7.7 and double stage passivity at a pH of 8.4. The first passive layer is due to the dissolution mechanism and second passivity is related to stable passivation. The cast sample shows single stage passivity in the solution of pH 8.4. The difference in the passivation behaviour for the cast alloy (Fe80Si20) and the coating is related to the presence of highly iron-enriched localized regions, formed during the processing stage of coating.

  2. Study of the reduction of particle emissions and borate black liquor gasification in bioenergy systems

    Energy Technology Data Exchange (ETDEWEB)

    Leduc, Sylvain

    2004-11-01

    zone of the boiler. The results from the simulations were validated against measurements. The temperature field was well described and the velocity field was predicted with acceptable accuracy. Chemical reactions were not included in these simulations. Turbulence was modelled using the RNG k-{epsilon} model, which is relatively easy to use. This thesis also performs a study on a new model of black liquor gasification with borate autocausticizing, which has the potential to improve the production performance of pulp mills. The earlier model from Jansson did not have the efficiency expected, and was found unacceptable as a means of replacing the lime cycle. The new process has a real advantage compared to earlier borate autocausticizing processes; it can theoretically be led either on a full scale or as a part of the process to an ordinary causticizing and with moderate borate setting. The booster gasifier is studied. The material and energy balance is formulated for a sulphate- recycling block with this process and is compared with the conventional techniques. The results of the usual black liquor gasification were very close to reality and very promising. Regarding the black liquor gasification with borate, lack of data for the orthoborate, like the Gibbs free energy, did not enable good accuracy of the results. The model is so far a good start in black liquor gasification, but it needs to be improved as soon as some new data are available.

  3. Characterization of berkelium(III) dipicolinate and borate compounds in solution and the solid state.

    Science.gov (United States)

    Silver, Mark A; Cary, Samantha K; Johnson, Jason A; Baumbach, Ryan E; Arico, Alexandra A; Luckey, Morgan; Urban, Matthew; Wang, Jamie C; Polinski, Matthew J; Chemey, Alexander; Liu, Guokui; Chen, Kuan-Wen; Van Cleve, Shelley M; Marsh, Matthew L; Eaton, Teresa M; van de Burgt, Lambertus J; Gray, Ashley L; Hobart, David E; Hanson, Kenneth; Maron, Laurent; Gendron, Frédéric; Autschbach, Jochen; Speldrich, Manfred; Kögerler, Paul; Yang, Ping; Braley, Jenifer; Albrecht-Schmitt, Thomas E

    2016-08-26

    Berkelium is positioned at a crucial location in the actinide series between the inherently stable half-filled 5f(7) configuration of curium and the abrupt transition in chemical behavior created by the onset of a metastable divalent state that starts at californium. However, the mere 320-day half-life of berkelium's only available isotope, (249)Bk, has hindered in-depth studies of the element's coordination chemistry. Herein, we report the synthesis and detailed solid-state and solution-phase characterization of a berkelium coordination complex, Bk(III)tris(dipicolinate), as well as a chemically distinct Bk(III) borate material for comparison. We demonstrate that berkelium's complexation is analogous to that of californium. However, from a range of spectroscopic techniques and quantum mechanical calculations, it is clear that spin-orbit coupling contributes significantly to berkelium's multiconfigurational ground state. PMID:27563098

  4. Broad-spectrum antibacterial properties of metal-ion doped borate bioactive glasses for clinical applications

    Science.gov (United States)

    Ottomeyer, Megan

    Bioactive glasses with antimicrobial properties can be implemented as coatings on medical devices and implants, as well as a treatment for tissue repair and prevention of common hospital-acquired infections such as MRSA. A borate-containing glass, B3, is also undergoing clinical trials to assess wound-healing properties. The sensitivities of various bacteria to B3, B3-Ag, B3-Ga, and B3-I bioactive glasses were tested. In addition, the mechanism of action for the glasses was studied by spectroscopic enzyme kinetics experiments, Live-Dead staining fluorescence microscopy, and luminescence assays using two gene fusion strains of Escherichia coli. It was found that gram-positive bacteria were more sensitive to all four glasses than gram negative bacteria, and that a single mechanism of action for the glasses is unlikely, as the rates of catalysis for metabolic enzymes as well as membrane permeability were altered after glass exposure.

  5. Thermal properties of borate crystals for high power optical parametric chirped-pulse amplification.

    Science.gov (United States)

    Riedel, R; Rothhardt, J; Beil, K; Gronloh, B; Klenke, A; Höppner, H; Schulz, M; Teubner, U; Kränkel, C; Limpert, J; Tünnermann, A; Prandolini, M J; Tavella, F

    2014-07-28

    The potential of borate crystals, BBO, LBO and BiBO, for high average power scaling of optical parametric chirped-pulse amplifiers is investigated. Up-to-date measurements of the absorption coefficients at 515 nm and the thermal conductivities are presented. The measured absorption coefficients are a factor of 10-100 lower than reported by the literature for BBO and LBO. For BBO, a large variation of the absorption coefficients was found between crystals from different manufacturers. The linear and nonlinear absorption coefficients at 515 nm as well as thermal conductivities were determined for the first time for BiBO. Further, different crystal cooling methods are presented. In addition, the limits to power scaling of OPCPAs are discussed. PMID:25089381

  6. Dispersive waves induced by self-defocusing temporal solitons in a beta-barium-borate crystal.

    Science.gov (United States)

    Zhou, Binbin; Bache, Morten

    2015-09-15

    We experimentally observe dispersive waves in the anomalous dispersion regime of a beta-barium-borate (BBO) crystal, induced by a self-defocusing few-cycle temporal soliton. Together the soliton and dispersive waves form an energetic octave-spanning supercontinuum. The soliton was excited in the normal dispersion regime of BBO through a negative cascaded quadratic nonlinearity. Using pump wavelengths from 1.24 to 1.4 μm, dispersive waves are found from 1.9 to 2.2 μm, agreeing well with calculated resonant phase-matching wavelengths due to degenerate four-wave mixing to the soliton. We also observe resonant radiation from nondegenerate four-wave mixing between the soliton and a probe wave, which was formed by leaking part of the pump spectrum into the anomalous dispersion regime. We confirm the experimental results through simulations.

  7. Mechanical and thermal properties of denture PMMA reinforced with silanized aluminum borate whiskers.

    Science.gov (United States)

    Zhang, Xinjing; Zhang, Xiuyin; Zhu, Bangshang; Lin, Kaili; Chang, Jiang

    2012-01-01

    The aim of this study was to investigate the mechanical and thermal properties of denture polymethyl methacrylate (PMMA) reinforced with aluminum borate whiskers (ABWs). To improve bonding between ABWs and PMMA matrix, the surface of ABWs was modified with a silane coupling agent. Varied contents of silanized ABWs -ranging between 1 and 20 wt%- were mixed into the PMMA resin matrix to prepare ABW/PMMA composites, which were subjected to three-point bending test, Vickers hardness test, and thermal analysis. Silanized ABWs improved the flexural strength, surface hardness, and thermal stability of PMMA. Optimal amount of ABWs in the PMMA matrix was 5 wt%, which provided the ABW/PMMA with maximum reinforcement.

  8. Corrosion and Passivation of Nickel Rotating Disk Electrode in Borate Buffer Solution

    International Nuclear Information System (INIS)

    The electrochemical corrosion and passivation of Ni rotating disk electrod in borate buffer solution was studied with potentiodynamic and electrochemical impedance spectroscopy. The mechanisms of both the active dissolution and passivation of nickel and the hydrogen evolution in reduction reaction were hypothetically established while utilizing the Tafel slope, impedance data, the rotation speed of Ni-RDE and the pH dependence of corrosion potential and current. Based on the EIS data, an equivalent circuit was suggested. In addition, carefully measured were the electrochemical parameters for specific anodic dissolution regions. It can be concluded from the data collected that the Ni(OH)2 oxide film, which is primarily formed by passivation, is converted to NiO by dehydration under the influence of an electrical field

  9. Thermal properties of borate crystals for high power optical parametric chirped-pulse amplification.

    Science.gov (United States)

    Riedel, R; Rothhardt, J; Beil, K; Gronloh, B; Klenke, A; Höppner, H; Schulz, M; Teubner, U; Kränkel, C; Limpert, J; Tünnermann, A; Prandolini, M J; Tavella, F

    2014-07-28

    The potential of borate crystals, BBO, LBO and BiBO, for high average power scaling of optical parametric chirped-pulse amplifiers is investigated. Up-to-date measurements of the absorption coefficients at 515 nm and the thermal conductivities are presented. The measured absorption coefficients are a factor of 10-100 lower than reported by the literature for BBO and LBO. For BBO, a large variation of the absorption coefficients was found between crystals from different manufacturers. The linear and nonlinear absorption coefficients at 515 nm as well as thermal conductivities were determined for the first time for BiBO. Further, different crystal cooling methods are presented. In addition, the limits to power scaling of OPCPAs are discussed.

  10. Optical properties of down-shifting barium borate glass for CdTe solar cells

    Science.gov (United States)

    Loos, Sebastian; Steudel, Franziska; Ahrens, Bernd; Schweizer, Stefan

    2015-03-01

    CdTe thin film solar cells have a poor response in the ultraviolet and blue spectral range, mainly due to absorption and thermalization losses in the CdS buffer layer. To overcome this efficiency drop in the short wavelength range trivalent rare-earth doped barium borate glass is investigated for its potential as frequency down-shifting cover glass on top of the cell. The glass is doped with either Tb3+ or Eu3+ up to a level of 2.5 at.% leading to strong absorption in the ultraviolet/blue spectral range. Tb3+ shows intense emission bands in the green spectral range while Eu3+ emits in the orange/red spectral range. Based on rare-earth absorption and luminescence quantum efficiency the possible gain in short-circuit current density is calculated.

  11. The corrosion behaviour of rare-earth containing magnesium alloys in borate buffer solution

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, R. [ICEMS, Instituto Superior Tecnico, Technical University of Lisbon (Portugal); Ferreira, M.G.S. [ICEMS, Instituto Superior Tecnico, Technical University of Lisbon (Portugal); CICECO, Universidade de Aveiro (Portugal); Carmezim, M.J. [ICEMS, Instituto Superior Tecnico, Technical University of Lisbon (Portugal); Instituto Politecnico de Setubal, ESTSetubal, DEM (Portugal); Montemor, M.F., E-mail: mfmontemor@ist.utl.p [ICEMS, Instituto Superior Tecnico, Technical University of Lisbon (Portugal)

    2011-01-01

    In this work, the corrosion behaviour of magnesium alloys ZK31, EZ33 and WE54 was studied in sodium borate buffer solution at pH 9.2. The electrochemical processes were studied by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The composition and morphology of the alloys and corrosion products formed were studied by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The experimental findings highlighted the differences in the corrosion mechanisms of the different alloys tested. The results showed that the presence of rare-earth elements (RE) only increases the corrosion resistance when present in solid solution, as is the case of the WE54 alloy. At pH 9.2, an amorphous yttrium oxide/hydroxide thick film was formed, which possesses greater stability when compared to magnesium oxide/hydroxide. The role of RE in the corrosion mechanism was discussed.

  12. The passivity of Type 316L stainless steel in borate buffer solution

    International Nuclear Information System (INIS)

    The passivity of Type 316 SS in borate buffer solution (pH 8.35), in the steady-state, has been explored using a variety of electrochemical techniques, including potentiostatic polarization, Mott Schottky analysis, and electrochemical impedance spectroscopy. The study shows that the passive film is an n-type semiconductor with a donor density that is essentially independent of voltage across the passive state. The passive current density is also found to be voltage-independent, but the thickness of the barrier layer depends linearly on the applied voltage. These observations are consistent with the predictions of the Point Defect Model, noting that the point defects within the barrier layer of the passive film are metal interstitials or oxygen vacancies, or both. No evidence for p-type behavior was obtained, indicating that cation vacancies do not have a significant population density in the film compared with the two donors (cation interstitials and oxygen vacancies)

  13. Highly active cobalt phosphate and borate based oxygen evolving catalysts operating in neutral and natural waters

    Energy Technology Data Exchange (ETDEWEB)

    Esswein, AJ; Surendranath, Y; Reece, SY; Nocera, DG

    2011-02-01

    A high surface area electrode is functionalized with cobalt-based oxygen evolving catalysts (Co-OEC = electrodeposited from pH 7 phosphate, Pi, pH 8.5 methylphosphonate, MePi, and pH 9.2 borate electrolyte, Bi). Co-OEC prepared from MePi and operated in Pi and Bi achieves a current density of 100 mA cm(-2) for water oxidation at 442 and 363 mV overpotential, respectively. The catalyst retains activity in near-neutral pH buffered electrolyte in natural waters such as those from the Charles River (Cambridge, MA) and seawater (Woods Hole, MA). The efficacy and ease of operation of anodes functionalized with Co-OEC at appreciable current density together with its ability to operate in near neutral pH buffered natural water sources bodes well for the translation of this catalyst to a viable renewable energy storage technology.

  14. Dispersive waves induced by self-defocusing temporal solitons in a beta-barium-borate crystal.

    Science.gov (United States)

    Zhou, Binbin; Bache, Morten

    2015-09-15

    We experimentally observe dispersive waves in the anomalous dispersion regime of a beta-barium-borate (BBO) crystal, induced by a self-defocusing few-cycle temporal soliton. Together the soliton and dispersive waves form an energetic octave-spanning supercontinuum. The soliton was excited in the normal dispersion regime of BBO through a negative cascaded quadratic nonlinearity. Using pump wavelengths from 1.24 to 1.4 μm, dispersive waves are found from 1.9 to 2.2 μm, agreeing well with calculated resonant phase-matching wavelengths due to degenerate four-wave mixing to the soliton. We also observe resonant radiation from nondegenerate four-wave mixing between the soliton and a probe wave, which was formed by leaking part of the pump spectrum into the anomalous dispersion regime. We confirm the experimental results through simulations. PMID:26371910

  15. Long Lasting Phosphorescence in Eu2+ and Ce3+ Co-Doped Strontium Borate Glasses

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Long lasting phosphorescence (LLP) was observed in Eu2+, Ce3+ co-doped strontium borate glasses prepared under the reducing atmosphere due to the emission of both Eu2+ and Ce3+. The methods of photoluminescence, thermoluminescence and phosphorescence were used to study the samples, and possible mechanism was suggested. The co-doping of Ce3+ ions poisoned the phosphorescence emission of Eu2+ because of the competition to obtain the trapped electron. The phosphorescence of Ce3+ in the sample decays more quickly than that of Eu2+, which is suggested for the reason that the emission energy of Ce3+ is higher or the distance between Ce3+ and electron traps of the glasses is longer.

  16. The passivity of Type 316L stainless steel in borate buffer solution

    Science.gov (United States)

    Nicic, Igor; Macdonald, Digby D.

    2008-09-01

    The passivity of Type 316 SS in borate buffer solution (pH 8.35), in the steady-state, has been explored using a variety of electrochemical techniques, including potentiostatic polarization, Mott Schottky analysis, and electrochemical impedance spectroscopy. The study shows that the passive film is an n-type semiconductor with a donor density that is essentially independent of voltage across the passive state. The passive current density is also found to be voltage-independent, but the thickness of the barrier layer depends linearly on the applied voltage. These observations are consistent with the predictions of the Point Defect Model, noting that the point defects within the barrier layer of the passive film are metal interstitials or oxygen vacancies, or both. No evidence for p-type behavior was obtained, indicating that cation vacancies do not have a significant population density in the film compared with the two donors (cation interstitials and oxygen vacancies).

  17. Nonlinear optical properties of silver nanoparticles prepared in Ag doped borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Adamiv, V.T. [Institute of Physical Optics, Dragomanov str. 23, Lviv 79005 (Ukraine); Bolesta, I.M. [Ivan Franko National University, Dragomanov str. 50, Lviv 79005 (Ukraine); Burak, Ya.V., E-mail: burak@ifo.lviv.ua [Institute of Physical Optics, Dragomanov str. 23, Lviv 79005 (Ukraine); Gamernyk, R.V.; Karbovnyk, I.D.; Kolych, I.I.; Kovalchuk, M.G.; Kushnir, O.O.; Periv, M.V. [Ivan Franko National University, Dragomanov str. 50, Lviv 79005 (Ukraine); Teslyuk, I.M. [Institute of Physical Optics, Dragomanov str. 23, Lviv 79005 (Ukraine)

    2014-09-15

    Nonlinear properties of Li{sub 2}B{sub 4}O{sub 7}:Ag borate glasses with “Li{sub 2}B{sub 4}O{sub 7}:Ag nanoparticles” interface region formed by thermal treatment in hydrogen atmosphere and in vacuum are investigated. From the results of plasmon absorption and normalized transmission measurements in Z-scan regime it was ascertained that “Li{sub 2}B{sub 4}O{sub 7}:AgNPs” interface region changes the character of nonlinear refraction of Li{sub 2}B{sub 4}O{sub 7}:Ag glass from negative to positive, and, due to plasmon resonance, increases significantly its nonlinear properties. In particular, the observed growth of nonlinear refractive index n{sub 2} is more than four orders of magnitude.

  18. In situ hydroxyapatite nanofiber growth on calcium borate silicate ceramics in SBF and its structural characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Pu, Yinfu; Huang, Yanlin; Qi, Shuyun [College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123 (China); Chen, Cuili [Department of Physics and Interdisciplinary Program of Biomedical, Mechanical & Electrical Engineering, Pukyong National University, Busan 608-737 (Korea, Republic of); Seo, Hyo Jin, E-mail: hjseo@pknu.ac.kr [Department of Physics and Interdisciplinary Program of Biomedical, Mechanical & Electrical Engineering, Pukyong National University, Busan 608-737 (Korea, Republic of)

    2015-10-01

    A novel calcium silicate borate Ca{sub 11}Si{sub 4}B{sub 2}O{sub 22} ceramic was firstly prepared by the conventional solid-state reaction. In vitro hydroxyapatite mineralization was investigated by soaking the ceramics in simulated body fluid (SBF) solutions at body temperature (37 °C) for various time periods. Scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD) measurements were applied to investigate the samples before and after the immersion of ceramics in SBF solution. The elemental compositions of a hydroxyapatite layer on the ceramics during the mineralization were confirmed by X-ray energy-dispersive spectra (EDS). Meanwhile, the bending strength and elastic modulus of Ca{sub 11}Si{sub 4}B{sub 2}O{sub 22} ceramics were also measured, which indicate that the biomaterials based on Ca{sub 11}Si{sub 4}B{sub 2}O{sub 22} ceramics possess bioactivity and might be a potential candidate as biomaterials for hard tissue repair. The bioactive mineralization ability was evaluated on the base of its crystal structural characteristics, i.e., silanol (Si–OH) and B–OH groups can be easily induced on the surface of Ca{sub 11}Si{sub 4}B{sub 2}O{sub 22} ceramics soaked in SBF solutions. - Highlights: • Calcium silicate borate Ca{sub 11}Si{sub 4}B{sub 2}O{sub 22} ceramics were developed as a new biomaterial. • Ca{sub 11}Si{sub 4}B{sub 2}O{sub 22} shows a superior in vitro bioactivity by inducing bone-like apatite. • Ca{sub 11}Si{sub 4}B{sub 2}O{sub 22} has good mechanical properties as potential candidate biomaterials. • The structure with SiO{sub 4} and BO{sub 3} groups is favorable for hydroxyapatite formation.

  19. In situ hydroxyapatite nanofiber growth on calcium borate silicate ceramics in SBF and its structural characteristics

    International Nuclear Information System (INIS)

    A novel calcium silicate borate Ca11Si4B2O22 ceramic was firstly prepared by the conventional solid-state reaction. In vitro hydroxyapatite mineralization was investigated by soaking the ceramics in simulated body fluid (SBF) solutions at body temperature (37 °C) for various time periods. Scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD) measurements were applied to investigate the samples before and after the immersion of ceramics in SBF solution. The elemental compositions of a hydroxyapatite layer on the ceramics during the mineralization were confirmed by X-ray energy-dispersive spectra (EDS). Meanwhile, the bending strength and elastic modulus of Ca11Si4B2O22 ceramics were also measured, which indicate that the biomaterials based on Ca11Si4B2O22 ceramics possess bioactivity and might be a potential candidate as biomaterials for hard tissue repair. The bioactive mineralization ability was evaluated on the base of its crystal structural characteristics, i.e., silanol (Si–OH) and B–OH groups can be easily induced on the surface of Ca11Si4B2O22 ceramics soaked in SBF solutions. - Highlights: • Calcium silicate borate Ca11Si4B2O22 ceramics were developed as a new biomaterial. • Ca11Si4B2O22 shows a superior in vitro bioactivity by inducing bone-like apatite. • Ca11Si4B2O22 has good mechanical properties as potential candidate biomaterials. • The structure with SiO4 and BO3 groups is favorable for hydroxyapatite formation

  20. Spectroscopic properties and luminescence behavior of Nd3+ doped zinc alumino bismuth borate glasses

    Science.gov (United States)

    Mahamuda, Sk.; Swapna, K.; Srinivasa Rao, A.; Jayasimhadri, M.; Sasikala, T.; Pavani, K.; Rama Moorthy, L.

    2013-09-01

    Zinc Alumino Bismuth Borate (ZnAlBiB) glasses doped with different concentrations of neodymium are prepared by using the melt quenching technique to study their physical, absorption and luminescence properties to understand the lasing potentialities of these glasses. From the absorption spectra various spectroscopic parameters and Judd-Ofelt (JO) parameters are evaluated. These JO parameters are used to calculate the transition probability (A), radiative lifetime (τR), and branching ratios (βR) for most of the fluorescent levels of Nd3+. The emission spectra recorded for these glasses gives three prominent transitions 4F3/2→4I9/2, 4F3/2→4I11/2 and 4F3/2→4I13/2 for which effective band widths (ΔλP) and stimulated emission cross-sections (σse) are evaluated. Branching ratios and stimulated emission cross-sections measured for all these glasses show that the 4F3/2→4I11/2 transition under investigation has the potential for laser applications. The intensity of Nd3+ emission spectra increases with increasing concentrations of Nd3+ up to 1 mol% and beyond 1 mol% the concentration quenching is observed. The high stimulated emission cross-section and branching ratios from the present glasses suggests their potential for infrared lasers. From the absorption and emission spectral studies it was found that, 1 mol% of Nd3+ ion concentration is optimum for Zinc Alumino Bismuth Borate glasses to generate a strong laser emission at 1060 nm.

  1. Conductivity and modulus formulation in lithium modified bismuth zinc borate glasses

    Science.gov (United States)

    Dahiya, Sajjan; Punia, R.; Murugavel, S.; Maan, A. S.

    2016-05-01

    The conductivity and modulus formulation in lithium modified bismuth zinc borate glasses with compositions xLi2O-(50-x) Bi2O3-10ZnO-40B2O3 has been studied in the frequency range 0.1 Hz-1.5 × 105 Hz in the temperature range 573 K-693 K. The temperature and frequency dependent conductivity is found to obey Jonscher's universal power law for all the studied compositions, the dc conductivity (σdc), crossover frequency (ωH), and frequency exponent (s) have been estimated from the fitting of the experimental data of ac conductivity with Jonscher's universal power law. Enthalpy to dissociate the cation from its original site next to a charge compensating centre (Hf) and enthalpy of migration (Hm) have been estimated. It has been observed that number of charge carriers and ac conductivity in the lithium modified bismuth zinc borate glasses increases with increase in Li2O content. Further, the conduction mechanism in the glass sample with x = 0 may be due to overlapping large polaron tunneling, whereas, conduction mechanism in other studied glass samples more or less follows diffusion controlled relaxation model. The ac conductivity is scaled using σdc and ωH as the scaling parameter and is found that these are suitable scaling parameter for conductivity scaling. Non-Debye type relaxation is found prevalent in the studied glass system. Scaling of ac conductivity as well as electric modulus confirms the presence of different type of conduction mechanism in the glass samples with x = 0 and 5 from other studied samples. The activation energy of relaxation (ER) and dc conductivity (Edc) are almost equal, suggesting that polarons/ions have to overcome same barrier while relaxing and conducting.

  2. Kinetics of fluorescence properties of Eu3+ion in strontium-aluminium-bismuth-borate glasses

    Institute of Scientific and Technical Information of China (English)

    M. Dhamodhara Naidu; D. Rajesh; A. Balakrishna; Y.C. Ratnakaram

    2014-01-01

    Eu3+doped strontium-aluminium-bismuth-borate glasses with the chemical composition (50–x)B2O3+20Bi2O3+7AlF3+8SrO+15SrF2+xEu2O3 (where x=0.1 mol.%, 0.5 mol.%, 1.0 mol.%and 1.5 mol.%) were prepared by the conventional melt quenching technique. Structural properties of the prepared glasses were analysed through X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and Raman spectral techniques. Thermal stability of glass was analysed by differential thermal analysis (DTA) curve. Photoluminescence characteristics were studied using excitation, emission spectra and decay curves of Eu3+doped strontium-aluminium-bismuth-borate glasses. The Judd-Ofelt (J-O) intensity parameters,Ωλ(λ=2, 4 and 6) were obtained using emission spectra and was used to identify the nature of Eu3+ions with their surrounding ligands. Using J-O parameters the tran-sition probabilities (A), stimulated emission cross-sections σEp , branching ratios (βR) and radiative lifetimes (τmeas and τcal) were evaluated for the 5D0→7FJ (J=0, 1, 2, 3 and 4) transition of Eu3+ions in the present glasses. The decay profiles were found to be non exponential for all the concentrations and the measured lifetimes (τmeas) were obtained from the decay profiles. The higher values of A,σEp ,βR and quantum efficiency (η) for 5D0→7F2 emission transition at 617 nm confirmed the present glass was as active medium for red laser emission applications.

  3. Interstitial incorporation of plutonium into a low-dimensional potassium borate.

    Science.gov (United States)

    Wang, Shuao; Diwu, Juan; Simonetti, Antonio; Booth, Corwin H; Albrecht-Schmitt, Thomas E

    2011-11-01

    The molten boric acid flux reaction of PuBr(3) with KBO(2) at 200 °C results in the formation of large light-yellow crystals of K[B(5)O(7)(OH)(2)]·H(2)O:Pu(4+). Single-crystal X-ray diffraction experiments on the Pu-doped K[B(5)O(7)(OH)(2)]·H(2)O demonstrate two features: (1) K[B(5)O(7)(OH)(2)]·H(2)O:Pu(4+) adopts a one-dimensional borate chain structure with void spaces between the chains. (2) The doping plutonium atoms do not reside on the potassium sites. The latter are not fully occupied. Both laser-ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and energy-dispersive spectrometry analyses indicate that plutonium atoms are uniformly distributed in crystals of K[B(5)O(7)(OH)(2)]·H(2)O with an atomic K:Pu ratio of approximately 65:1 measured by LA-ICP-MS. UV-vis-NIR spectra taken from both freshly made and one day old crystals show that the plutonium present within the crystals is predominantly characterized by Pu(IV). A small amount of Pu(III) is also present initially, but slowly oxidized to Pu(IV) via interaction with oxygen in the air. X-ray absorption near-edge structure and extended X-ray absorption fine structure spectroscopic measurements confirm that plutonium is mainly present as a form similar to that of a PuO(2) cluster. The combined results suggest that the clusters containing Pu(IV) ions are uniformly distributed in the void spaces between the borate chains.

  4. Advanced Detection Technology of Trace-level Borate for SG Leakage Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seban; Kang, Dukwon; Kim, Seungil; Kim, Hyunki; Heo, Jun; Sung, Jinhyun [Radiation Eng. Center, Shihung (Korea, Republic of); Lee, Dongbum [Academic Support Dept., Seoul (Korea, Republic of)

    2013-05-15

    Many studies have been reported for monitoring technology of steam generator, however, all of these methods have their own limitations. The leakage monitoring technology of steam generator of PWR has also got a limit due to the adoption of specific radionuclides (N-16, Ar-41, H-3, Xe, etc.) generated by nuclear fission, which are available only when reactor output is 20% or more. Most of domestic NPPs apply the N-16 technique for monitoring tube leakage but it has some problem that it is difficult to calculate the leakage rate because neutron flux are not completely formed during low power operation. For example, tube leakage of steam generator occurred in the Uljin nuclear power plant in 2002 during coast down operation for periodic plant maintenance. This plant could not prevent a rupture accident in advance because N-16 method is not possible the leak monitoring less than 20% reactor power. The development of excellent alternative monitoring technology that can monitor the real-time leakage is required under a variety of operating conditions like start-up and abnormal conditions of NPPs. This study was performed to lay a foundation in monitoring the leakage of steam generator coping with the lower output and low power operational condition using trace level of boron which is non-radioactive nuclide to inject control neutron injection. In this study, non-radioactive nuclide boron ion, which existed in the secondary system water, as leakage monitoring indicator was investigated for the separation of complex cation and anion phase. Borate was detected by using borate concentrator column coupled with the ion-exclusion column analytical column, revealing the problem of overlapped peak between fluoride and boron ions. Meanwhile, ion-exchange column could confirm the possibility as a leakage monitoring indicator of steam generator, despite the peak of glycolic acid salts was slightly overlapped. It will be needed for further research regarding the selectivity of the

  5. High-Pressure Synthesis and Characterization of the Actinide Borate Phosphate U2[BO4][PO4].

    Science.gov (United States)

    Hinteregger, Ernst; Wurst, Klaus; Perfler, Lukas; Kraus, Florian; Huppertz, Hubert

    2013-10-14

    A new actinide borate phosphate, U2[BO4][PO4], was synthesized in a Walker-type multianvil apparatus at 12.5 GPa and 1000 °C. The crystal structure was determined from single-crystal X-ray diffraction data collected at room temperature. U2[BO4][PO4] crystallizes in the monoclinic space group P21/c with four formula units per unit cell and the lattice parameters a = 854.6(2), b = 775.3(2), c = 816.3(2) pm, and β = 102.52(3)°. The structure consists of double layers of linked uranium-oxygen polyhedra parallel to [100]. The borate tetrahedra are located between the uranium-oxygen layers inside the double layer. The phosphate groups link the double layers. PMID:24611029

  6. Hydrotris(triazolyl)borate complexes as functional models for Cu nitrite reductase: the electronic influence of distal nitrogens.

    Science.gov (United States)

    Kumar, Mukesh; Dixon, Natalie A; Merkle, Anna C; Zeller, Matthias; Lehnert, Nicolai; Papish, Elizabeth T

    2012-07-01

    Hydrotris(triazolyl)borate (Ttz) ligands form CuNO(x) (x = 2, 3) complexes for structural and functional models of copper nitrite reductase. These complexes have distinct properties relative to complexes of hydrotris(pyrazolyl)borate (Tp) and neutral tridentate N-donor ligands. The electron paramagnetic resonance spectra of five-coordinate copper complexes show rare nitrogen superhyperfine couplings with the Ttz ligand, indicating strong σ donation. The copper(I) nitrite complex [PPN](+)[(Ttz(tBu,Me))Cu(I)NO(2)](-) has been synthesized and characterized and allows for the stoichiometric reduction of NO(2)(-) to NO with H(+) addition. Anionic Cu(I) nitrite complexes are unusual and are stabilized here for the first time because Ttz is a good π acceptor. PMID:22671968

  7. Agrobacterium-mediated transformation of kabocha squash (Cucurbita moschata Duch) induced by wounding with aluminum borate whiskers.

    Science.gov (United States)

    Nanasato, Yoshihiko; Konagaya, Ken-ichi; Okuzaki, Ayako; Tsuda, Mai; Tabei, Yutaka

    2011-08-01

    An efficient genetic transformation method for kabocha squash (Cucurbita moschata Duch cv. Heiankogiku) was established by wounding cotyledonary node explants with aluminum borate whiskers prior to inoculation with Agrobacterium. Adventitious shoots were induced from only the proximal regions of the cotyledonary nodes and were most efficiently induced on Murashige-Skoog agar medium with 1 mg/L benzyladenine. Vortexing with 1% (w/v) aluminum borate whiskers significantly increased Agrobacterium infection efficiency in the proximal region of the explants. Transgenic plants were screened at the T(0) generation by sGFP fluorescence, genomic PCR, and Southern blot analyses. These transgenic plants grew normally and T(1) seeds were obtained. We confirmed stable integration of the transgene and its inheritance in T(1) generation plants by sGFP fluorescence and genomic PCR analyses. The average transgenic efficiency for producing kabocha squashes with our method was about 2.7%, a value sufficient for practical use.

  8. In-situ Quasi-Instantaneous e-beam Driven Catalyst-Free Formation Of Crystalline Aluminum Borate Nanowires

    OpenAIRE

    Ignacio G. Gonzalez-Martinez; Thomas Gemming; Rafael Mendes; Alicja Bachmatiuk; Viktor Bezugly; Jens Kunstmann; Jürgen Eckert; Gianaurelio Cuniberti; Rümmeli, Mark H

    2016-01-01

    The catalyst-assisted nucleation and growth mechanisms for many kinds of nanowires and nanotubes are pretty well understood. At times, though, 1D nanostructures form without a catalyst and the argued growth modes have inconsistencies. One such example is the catalyst-free growth of aluminium borate nanowires. Here we develop an in-situ catalyst-free room temperature growth route for aluminium nanowires using the electron beam in a transmission electron microscope. We provide strong experiment...

  9. Borate cross-linking chitosan/graphene oxide films: Toward the simultaneous enhancement of gases barrier and mechanical properties

    Science.gov (United States)

    Yan, Ning; Capezzuto, Filomena; Buonocore, Giovanna G.; Tescione, Fabiana; Lavorgna, Marino; Xia, Hesheng; Ambrosio, Luigi

    2015-12-01

    Borate adducts, originated from hydrolysis of sodium tetraborate decahydrate (borax), have been used to crosslink chitosan (CS) and graphene oxide (GO) nanosheets for the production of innovative composite sustainable materials. CS/GO film consisting of 10wt% borax and 1wt% GO exhibits a significant improvement of both toughness and oxygen barrier properties in comparison to pristine chitosan. In particular the tensile strength increases by about 100% and 150% after thermal annealing of samples at 90°C for 50min whereas the oxygen permeability reduces of about 90% compared to pristine chitosan. The enhancement of both mechanical and barrier properties is ascribed to the formation of a resistant network due to the chemical crosslinking, including borate orthoester bonds and hydroxyl moieties complexes, formed among borate ions, chitosan, and GO nanoplatelets. The crosslinked graphene-based chitosan material with its enhanced mechanical and barrier properties may significantly broad the range of applications of chitosan based-materials which presently are very limited and addressed only to packaging.

  10. Boron isotope composition of geothermal fluids and borate minerals from salar deposits (central Andes/NW Argentina)

    Science.gov (United States)

    Kasemann, Simone A.; Meixner, Anette; Erzinger, Jörg; Viramonte, José G.; Alonso, Ricardo N.; Franz, Gerhard

    2004-06-01

    We have measured the boron concentration and isotope composition of regionally expansive borate deposits and geothermal fluids from the Cenozoic geothermal system of the Argentine Puna Plateau in the central Andes. The borate minerals borax, colemanite, hydroboracite, inderite, inyoite, kernite, teruggite, tincalconite, and ulexite span a wide range of δ11B values from -29.5 to -0.3‰, whereas fluids cover a range from -18.3 to 0.7‰. The data from recent coexisting borate minerals and fluids allow for the calculation of the isotope composition of the ancient mineralizing fluids and thus for the constraint of the isotope composition of the source rocks sampled by the fluids. The boron isotope composition of ancient mineralizing fluids appears uniform throughout the section of precipitates at a given locality and similar to values obtained from recent thermal fluids. These findings support models that suggest uniform and stable climatic, magmatic, and tectonic conditions during the past 8 million years in this part of the central Andes. Boron in fluids is derived from different sources, depending on the drainage system and local country rocks. One significant boron source is the Paleozoic basement, which has a whole-rock isotopic composition of δ11B=-8.9±2.2‰ (1 SD); another important boron contribution comes from Neogene-Pleistocene ignimbrites ( δ11B=-3.8±2.8‰, 1 SD). Cenozoic andesites and Mesozoic limestones ( δ11B≤+8‰) provide a potential third boron source.

  11. Social and political perceptions of the Borat phenomenon in Kazakhstan: evidence from a case study of university students

    Directory of Open Access Journals (Sweden)

    Donnacha Ó Beacháin

    2011-11-01

    Full Text Available This article begins by chronicling and evaluating the reaction of the government of Kazakhstan to Sacha Baron Cohen’s film Borat—Cultural Learnings of America for Make Benefit Glorious Nation of Kazakhstan. It then compares and contrasts the official government reaction with the expressed attitudes of local members of Kazakhstan’s young English-speaking elites. This study is based on the results of a survey of almost five hundred young university students conducted in March 2007 at the Kazakhstan Institute of Management, Economics and Strategic Research (KIMEP, the most prestigious university in the country. The sample gives a snapshot of those most likely to have been aware of Borat – the young, internet-savvy, educated urban elite – and inter alia provides insights into how respondents in Kazakhstan thought the movie impacted their country and would influence how they were treated abroad. The survey results suggest that while responses to Borat were heterogeneous, most students accepted that the choice of Kazakhstan as a target for satire was coincidental rather than conspiratorial. Despite official efforts to ban the movie, a majority of the respondents had seen the film and believed that the ban was a mistake. Also, while recognising that Borat would raise Kazakhstan’s profile in the world, respondents doubted it would increase knowledge, and some feared a change in their treatment when travelling abroad.

  12. Scale-up synthesis of zinc borate from the reaction of zinc oxide and boric acid in aqueous medium

    Science.gov (United States)

    Kılınç, Mert; Çakal, Gaye Ö.; Yeşil, Sertan; Bayram, Göknur; Eroğlu, İnci; Özkar, Saim

    2010-11-01

    Synthesis of zinc borate was conducted in a laboratory and a pilot scale batch reactor to see the influence of process variables on the reaction parameters and the final product, 2ZnO·3B 2O 3·3.5H 2O. Effects of stirring speed, presence of baffles, amount of seed, particle size and purity of zinc oxide, and mole ratio of H 3BO 3:ZnO on the zinc borate formation reaction were examined at a constant temperature of 85 °C in a laboratory (4 L) and a pilot scale (85 L) reactor. Products obtained from the reaction in both reactors were characterized by chemical analysis, X-ray diffraction, particle size distribution analysis, thermal gravimetric analysis and scanning electron microscopy. The kinetic data for the zinc borate production reaction was fit by using the logistic model. The results revealed that the specific reaction rate, a model parameter, decreases with increase in particle size of zinc oxide and the presence of baffles, but increases with increase in stirring speed and purity of zinc oxide; however, it is unaffected with the changes in the amount of seed and reactants ratio. The reaction completion time is unaffected by scaling-up.

  13. In vitro study of improved wound-healing effect of bioactive borate-based glass nano-/micro-fibers.

    Science.gov (United States)

    Yang, Qingbo; Chen, Sisi; Shi, Honglan; Xiao, Hai; Ma, Yinfa

    2015-10-01

    Because of the promising wound-healing capability, bioactive glasses have been considered as one of the next generation hard- and soft-tissue regeneration materials. The lack of understanding of the substantial mechanisms, however, indicates the need for further study on cell-glass interactions to better interpret the rehabilitation capability. In the present work, three bioactive glass nano-/micro-fibers, silicate-based 45S5, borate-based 13-93B3 and 1605 (additionally doped with copper oxide and zinc oxide), were firstly compared for their in vitro soaking/conversion rate. The results of elemental monitoring and electron microscopic characterization demonstrated that quicker ion releasing and glass conversion occurred in borate-based fibers than that of silicate-based one. This result was also reflected by the formation speed of hydroxyapatite (HA). This process was further correlated with original boron content and surrounding rheological condition. We showed that an optimal fiber pre-soaking time (or an ideal dynamic flow rate) should exist to stimulate the best cell proliferation and migration ability. Moreover, 13-93B3 and 1605 fibers showed different glass conversion and biocompatibility properties as well, indicating that trace amount variation in composition can also influence fiber's bioactivity. In sum, our in vitro rheological module closely simulated in vivo niche environment and proved a potentially improved wound-healing effect by borate-based glass fibers, and the results shall cast light on future improvement in bioactive glass fabrication. PMID:26117744

  14. Investigation of Gamma and Neutron Shielding Parameters for Borate Glasses Containing NiO and PbO

    Directory of Open Access Journals (Sweden)

    Vishwanath P. Singh

    2014-01-01

    Full Text Available The mass attenuation coefficients, μ/ρ, half-value layer, HVL, tenth-value layer, TVL, effective atomic numbers, ZPIeff, and effective electron densities, Ne,eff, of borate glass sample systems of (100-x-y Na2B4O7 : xPbO : yNiO (where x and y=0, 2, 4, 6, 8, and 10 weight percentage containing PbO and NiO, with potential gamma ray and neutron shielding applications, have been investigated. The gamma ray interaction parameters, μ/ρ, HVL, TVL, ZPIeff, and Ne,eff, were computed for photon energy range 1 keV–100 GeV. The macroscopic fast neutron removal cross-sections (ΣR have also been calculated. Appreciable variations were noted for all the interaction parameters by varying the photon energy and the chemical composition of the glass samples. The better shielding properties of borate glass samples containing PbO were found. These results indicated that borate glass samples are a good radiation shielding material.

  15. Structure and lattice dynamics in non-centrosymmetric borates; Struktur und Gitterdynamik in azentrischen Boraten

    Energy Technology Data Exchange (ETDEWEB)

    Stein, W.D.R.

    2007-04-23

    This thesis deals with a study of structural and lattice dynamical properties of some noncentrosymmetric borates with outstanding non-linear optical properties. The focus was on the compound bismuth triborate (BiB{sub 3}O{sub 6}). The structure of the tetraborates MB{sub 4}O{sub 7} (M=Pb,Sr,Ba) was also investigated. The structural investigations in bismuth triborate include powder and single crystal diffraction experiments on X-ray and neutron sources. The crystal structure was under examination in the temperature range from 100 K to room temperature and the lattice constants in the temperature range from 20 K to 800 K. The lattice constants show a nearly linear dependency from temperature. Our observations are in good agreement with investigations of the thermal expansion, which shows a strong anisotropy within the layer-like structure of bismuth triborate. Within the borate layers, along the polar axis a strong positive and in the orthogonal direction a negative thermal expansion is observed. This effect can be explained by a zig-zag effect within the borate layers. The lone electron pair at the bismuth atom is discussed to be possibly the origin of the temperature dependency of the coordination environment of the bismuth atom. The influence of the lone electron pair on the crystal structure is raising by lowering the temperature. At the bismuth atom distinct anharmonic effects are observed, where the maximum points along the direction of the polar axis and therefore along the direction of the lone electron pair. The phonon dispersion of bismuth triborate has been investigated by inelastic neutron scattering. The low symmetry of the crystal structure depicts to be a special challenge. The dispersion was observed along the three reciprocal lattice constants. Along the polar axis the dispersion could be characterized to a maximum energy of 20 THz. The low energy acoustic branch along the polar axis shows a softening at the zone boundary. In the orthogonal

  16. Overview of ultraviolet and infrared spectroscopic properties of Yb{sup 3+} doped borate and oxy-borates compounds; De l'ultraviolet a l'infrarouge: caracterisation spectroscopique de materiaux type borate et oxyborate dopes a l'ytterbium trivalent

    Energy Technology Data Exchange (ETDEWEB)

    Sablayrolles, J

    2006-12-15

    The trivalent ytterbium ion can give rise to two emissions with different spectroscopic properties: the first one, with a short lifetime, in the ultraviolet (charge transfer emission) is used in detectors such as scintillators, and the other one, with a long lifetime, in the infrared (4f-4f emission) for laser applications. The strong link between material structure and properties is illustrated through ytterbium luminescence study, in the ultraviolet and infrared, inserted in the borate Li{sub 6}Y(BO{sub 3}){sub 3} and two oxy-borates: LiY{sub 6}O{sub 5}(BO{sub 3}){sub 3} and Y{sub 17,33}B{sub 8}O{sub 38}. For the first time an ytterbium charge transfer emission in oxy-borates has been observed. The calculation of the single configurational coordinate diagram, as well as the thermal quenching, has been conducted under a fundamental approach on the ytterbium - oxygen bond. The study of the ytterbium infrared spectroscopy in these compounds has been realised and an energy level attribution is proposed in the particular case of the borate Li{sub 6}Y(BO{sub 3}){sub 3}: Yb{sup 3+}. An original approach is introduced with the study of the charge transfer states for the three compounds by looking at the infrared emission. The first laser performances in three operating modes (continuous wave, Q-switch and mode locking) of a Li{sub 6}Y(BO{sub 3}){sub 3}: Yb{sup 3+} crystal are reported. (author)

  17. Role of oxygen on the optical properties of borate glass doped with ZnO

    International Nuclear Information System (INIS)

    Lithium tungsten borate glass (0.56-x)B2O3-0.4Li2O-xZnO-0.04WO3 (0≤x≤0.1 mol%) is prepared by the melt quenching technique for photonic applications. Small relative values of ZnO are used to improve the glass optical dispersion and to probe as well the role of oxygen electronic polarizability on its optical characteristics. The spectroscopic properties of the glass are determined in a wide spectrum range (200-2500 nm) using a Fresnel-based spectrophotometric technique. Based on the Lorentz-Lorenz theory, as ZnO content increases on the expense of B2O3 the glass molar polarizability increased due to an enhanced unshared oxide ion 2p electron density, which increases ionicity of the chemical bonds of glass. The role of oxide ion polarizability is explained in accordance with advanced measures and theories such as optical basicity, O 1s binding energy, the outer most cation binding energy in Yamashita-Kurosawa's interionic interaction parameter and Sun's average single bond strength. FT-IR measurements confirm an increase in bridging oxygen bonds, as a result of replacement of ZnO by B2O3, which increase the UV glass transmission window and transmittance. - Graphical abstract: O1s, Yamashita-Kurosawa's parameter and average single bond strength of charge overlapping between electronic shells are used to explain enhanced oxide ion 2p electron density, which increases refractive index of glasses. Highlights: → New borate glass for photonic application is prepared. → The dispersion property of the glass is effectively controlled using small amounts of ZnO. → ZnO is used to probe the glass structure and investigate the role of oxygen on the obtained optical properties of the glasses. → Modern theories are used to explain enhanced unshared oxide ion 2p electron density, which increases ionicity of chemical bonds of the glass.

  18. The ameliorative effect of grape seed extract(GSE) on sodium borate-inducing kidney injury of male albino rats

    International Nuclear Information System (INIS)

    Borax (sod-borate) is a toxic compound that is implicated daily to environmental pollutant, so occupational exposure leading to adverse effects on functions of some organs causing their damage as nephrotoxicity, neurotoxicity, hepatotoxicity and testicular atrophy . In particularly, kidney is the most organ that is affected by borax exposure due to continuous exposure with slow rate of excretion leading to accumulation in the renal tissue. Supplementation with high potent antioxidant grape seed extract may alleviate the worse damage effects induced in the kidney as a result of continual exposure of borax in our daily life. The current study aimed to evaluate the ameliorative effect of grape seed extract on renal injury of male albino rats intoxicated with sod-borate. Twenty eight male albino rats were classified to 4 groups(GI and II and III and IV).GI served as a control, group GII was a group intoxicated with sod-borate for 45 days, where as rats in GIII supplemented with GSE beside sod-borate for 45 days , GIV was a group supplemented with GSE only. Serum and kidney samples were collected for biochemical, histopathological and DNA examinations. Significant elevation in the levels of blood urea and creatinine in GII were observed when compared to control group(GI). Significant decline were prominent in biochemical kidney functions when intoxicated group supplemented with GSE(GIII) , where as non significant changes were observed between control group and group supplemented with GSE only (GIV). Significant increase in both cytokines TNF-α and IL-6 was observed in group intoxicated with sod-borate(GII) when compared to control rats(GI). Oral supplementation with high potent antioxidant GSE (GIII) caused alleviation in the kidney injury leading to the reduction of both pro-inflammatory mediator cytokines TNF-α and IL-6. DNA% fragment migration showed that worse significant migration of DNA fragements were observed in toxicated group(GII) followed by increase in

  19. Melting and freezing of spherical bismuth nanoparticles confined in a homogeneous sodium borate glass

    Science.gov (United States)

    Kellermann, G.; Craievich, A. F.

    2008-08-01

    The melting temperature and the crystallization temperature of Bi nanoclusters confined in a sodium borate glass were experimentally determined as functions of the cluster radius. The results indicate that, on cooling, liquid Bi nanodroplets exhibit a strong undercooling effect for a wide range of radii. The difference between the melting temperature and the freezing temperature decreases for decreasing radius and vanishes for Bi nanoparticles with a critical radius R=1.9nm . The magnitude of the variation in density across the melting and freezing transitions for Bi nanoparticles with R=2nm is 40% smaller than for bulk Bi. These experimental results support a basic core-shell model for the structure of Bi nanocrystals consisting of a central crystalline volume surrounded by a structurally disordered shell. The volume fraction of the crystalline core decreases for decreasing nanoparticle radius and vanishes for R=1.9nm . Thus, on cooling, the liquid nanodroplets with R<1.9nm preserve, across the liquid-to-solid transformation, their homogeneous and disordered structure without crystalline core.

  20. Ethylene glycol assisted low-temperature synthesis of boron carbide powder from borate citrate precursors

    Directory of Open Access Journals (Sweden)

    Rafi-ud-din

    2014-09-01

    Full Text Available B4C powders were synthesized by carbothermal reduction of ethylene glycol (EG added borate citrate precursors, and effects of EG additions (0–50 mol% based on citric acid on the morphologies and yields of synthesized B4C powders were investigated. The conditions most suitable for the preparation of precursor were optimized and optimum temperature for precursor formation was 650 °C. EG additions facilitated low-temperature synthesis of B4C at 1350 °C, which was around 100–300 °C lower temperature compared to that without EG additions. The lowering of synthesis temperature was ascribed to the enlargement of interfacial area caused by superior homogeneity and dispersibility of precursors enabling the diffusion of reacting species facile. The 20% EG addition was optimal with free residual carbon lowered to 4%. For smaller EG additions, the polyhedral and rod-like particles of synthesized product co-existed. With higher EG additions, the morphology of synthesized product was transformed into needle and blade-like structure.

  1. Effect of V2O5 on the dc conductivity of sodium bismuth borate glasses

    International Nuclear Information System (INIS)

    Transition metal doped quaternary glass system with composition 20Na2O-30Bi2O3-(50- x)B2O3-xV2O5 (where x = 0, 0.2, 0.3, 0.5, 2.0 mol%) has been prepared by normal melt-quench technique using analytical grade Na2CO3, Bi2O3, H3BO3, V2O5 chemicals. The main objective of present study is to investigate the effect of transition metal oxide on the conductivity mechanism of ternary alkali bismuth borate glasses. Density (D) and molar volume (VM) of each glass sample was calculated using Archimedes method. Differential scanning calorimetry (DSC) measurements were carried out at a heating rate of 10K/min for the determination of glass transition temperature Tg using Q10 DSC (TA Instruments). The values of dc conductivity and activation energy for conductivity and relaxation time have been calculated for all samples using sample dimensions. (author)

  2. Study of structural, electrical, and dielectric properties of phosphate-borate glasses and glass-ceramics

    Science.gov (United States)

    Melo, B. M. G.; Graça, M. P. F.; Prezas, P. R.; Valente, M. A.; Almeida, A. F.; Freire, F. N. A.; Bih, L.

    2016-08-01

    In this work, phosphate-borate based glasses with molar composition 20.7P2O5-17.2Nb2O5-13.8WO3-34.5A2O-13.8B2O3, where A = Li, Na, and K, were prepared by the melt quenching technique. The as-prepared glasses were heat-treated in air at 800 °C for 4 h, which led to the formation of glass-ceramics. These high chemical and thermal stability glasses are good candidates for several applications such as fast ionic conductors, semiconductors, photonic materials, electrolytes, hermetic seals, rare-earth ion host solid lasers, and biomedical materials. The present work endorses the analysis of the electrical conductivity of the as-grown samples, and also the electrical, dielectric, and structural changes established by the heat-treatment process. The structure of the samples was analyzed using X-Ray powder Diffraction (XRD), Raman spectroscopy, and density measurements. Both XRD and Raman analysis confirmed crystals formation through the heat-treatment process. The electrical ac and dc conductivities, σac and σdc, respectively, and impedance spectroscopy measurements as function of the temperature, varying from 200 to 380 K, were investigated for the as-grown and heat-treated samples. The impedance spectroscopy was measured in the frequency range of 100 Hz-1 MHz.

  3. Reddish-orange emission from Pr3+ doped zinc alumino bismuth borate glasses

    International Nuclear Information System (INIS)

    Praseodymium doped Zinc Alumino Bismuth Borate (ZnAlBiB) glasses were prepared by melt quenching technique and characterized by optical absorption and emission studies. The glassy nature of these glasses has been confirmed through XRD spectral measurements. From the absorption spectra, the Judd–Ofelt intensity parameters Ωλ (λ=2, 4 and 6) and other radiative properties like transition probability (AR), radiative lifetimes (τR) and branching ratios (βR) have been evaluated. Emission spectra were measured for different concentrations of Pr3+ ions doped glasses by exciting the glasses at 445 nm. The intensity of Pr3+ emission spectra increases from 0.1 to 1 mol% and beyond 1 mol% concentration quenching is observed. The suitable concentration of Pr3+ ions in ZnAlBiB glasses to act as a good lasing material at reddish-orange wavelength (604 nm) region has been discussed by measuring the emission cross-sections for the intense emission transition 1D2→3H4. The CIE chromaticity co-ordinates were also evaluated from the emission spectra for all the glasses to understand the suitability of these materials for reddish-orange emission. From the measured emission cross-sections and CIE chromaticity co-ordinates, it was found that 1 mol% of Pr3+ is aptly suitable for the development of visible reddish-orange lasers

  4. Optical characterization of Eu3+ and Tb3+ ions doped zinc lead borate glasses.

    Science.gov (United States)

    Thulasiramudu, A; Buddhudu, S

    2007-02-01

    This paper reports on the spectral analysis of Eu3+ or Tb3+ ions (0.5 mol%) doped heavy metal oxide (HMO) based zinc lead borate glasses from the measurement of their absorption, emission spectra and also different physical properties. From the XRD, DSC profiles, the glass nature and glass thermal properties have been studied. The measured emission spectrum of Eu3+ glass has revealed five transitions (5D0-->7F0, 7F1, 7F2, 7F3 and 7F4) at 578, 591, 613, 654 and 702 nm, respectively, with lambdaexci=392 nm (7F0-->5L6). In the case of Tb3+:ZLB glass, four emission transitions such as (5D4-->7F6, 7F5, 7F4 and 7F3) that are located at 489, 542, 585 and 622 nm, respectively, have been measured with lambdaexci=374 nm. For all these emission bands decay curves have been plotted to evaluate their lifetimes and the emission processes that arise in the glasses have been explained in terms of energy level schemes. PMID:16843052

  5. Gamma radiation shielding and optical properties measurements of zinc bismuth borate glasses

    International Nuclear Information System (INIS)

    Highlights: • 10ZnO:xBi2O3:(90−x)B2O3, (ZBB) glasses were prepared. • Radiation shielding and optical properties were investigated. • Higher 25 mol% of Bi2O3 show better shielding property compared with concretes. • ZBB glasses can develop as a Pb-free radiation shielding material. - Abstract: In this work, the zinc bismuth borate (ZBB) glasses of the composition 10ZnO:xBi2O3:(90−x)B2O3 (where x = 15, 20, 25 and 30 mol%) were prepared by the melt quenching technique. Their radiation shielding and optical properties were investigated and compared with theoretical calculations. The mass attenuation coefficients of ZBB glasses have been measured at different energies obtained from a Compton scattering technique. The results show a decrease of the mass attenuation coefficient, effective atomic number and effective electron density values with increasing of gamma-ray energies; and good agreements between experimental and theoretical values. The glass samples with Bi2O3 concentrations higher than 25 mol% (25 and 30 mol%) were observed with lower mean free path (MFP) values than all the standard shielding concretes studied. These results are indications that the ZBB glasses in the present study may be developed as a lead-free radiation shielding material in the investigated energy range

  6. Reddish-orange emission from Pr3+ doped zinc alumino bismuth borate glasses

    Science.gov (United States)

    Mahamuda, Sk.; Swapna, K.; Srinivasa Rao, A.; Sasikala, T.; Rama Moorthy, L.

    2013-11-01

    Praseodymium doped Zinc Alumino Bismuth Borate (ZnAlBiB) glasses were prepared by melt quenching technique and characterized by optical absorption and emission studies. The glassy nature of these glasses has been confirmed through XRD spectral measurements. From the absorption spectra, the Judd-Ofelt intensity parameters Ωλ (λ=2, 4 and 6) and other radiative properties like transition probability (AR), radiative lifetimes (τR) and branching ratios (βR) have been evaluated. Emission spectra were measured for different concentrations of Pr3+ ions doped glasses by exciting the glasses at 445 nm. The intensity of Pr3+ emission spectra increases from 0.1 to 1 mol% and beyond 1 mol% concentration quenching is observed. The suitable concentration of Pr3+ ions in ZnAlBiB glasses to act as a good lasing material at reddish-orange wavelength (604 nm) region has been discussed by measuring the emission cross-sections for the intense emission transition 1D2→3H4. The CIE chromaticity co-ordinates were also evaluated from the emission spectra for all the glasses to understand the suitability of these materials for reddish-orange emission. From the measured emission cross-sections and CIE chromaticity co-ordinates, it was found that 1 mol% of Pr3+ is aptly suitable for the development of visible reddish-orange lasers.

  7. Optical studies of Sm³⁺ ions doped zinc alumino bismuth borate glasses.

    Science.gov (United States)

    Swapna, K; Mahamuda, Sk; Srinivasa Rao, A; Shakya, S; Sasikala, T; Haranath, D; Vijaya Prakash, G

    2014-05-01

    Zinc Alumino Bismuth Borate (ZnAlBiB) glasses doped with different concentrations of samarium (Sm(3+)) ions were prepared by using melt quenching technique and characterized for their lasing potentialities in visible region by using the techniques such as optical absorption, emission and emission decay measurements. Radiative properties for various fluorescent levels of Sm(3+) ions were estimated from absorption spectral information using Judd-Ofelt (JO) analysis. The emission spectra and con-focal photoluminescence images obtained by 410 nm laser excitation demonstrates very distinct and intense orange-red emission for all the doped glasses. The suitable concentration of Sm(3+) ions in these glasses to act as an efficient lasing material has been discussed by measuring the emission cross-section and branching ratios for the emission transitions. The quantum efficiencies were also been estimated from emission decay measurements recorded for the (4)G5/2 level of Sm(3+) ions. From the measured emission cross-sections, branching ratios, strong photoluminescence features and CIE chromaticity coordinates, it was found that 1 mol% of Sm(3+) ions doped ZnAlBiB glasses are most suitable for the development of visible orange-red lasers. PMID:24530709

  8. Optical studies of Sm3+ ions doped Zinc Alumino Bismuth Borate glasses

    Science.gov (United States)

    Swapna, K.; Mahamuda, Sk.; Srinivasa Rao, A.; Shakya, S.; Sasikala, T.; Haranath, D.; Vijaya Prakash, G.

    Zinc Alumino Bismuth Borate (ZnAlBiB) glasses doped with different concentrations of samarium (Sm3+) ions were prepared by using melt quenching technique and characterized for their lasing potentialities in visible region by using the techniques such as optical absorption, emission and emission decay measurements. Radiative properties for various fluorescent levels of Sm3+ ions were estimated from absorption spectral information using Judd-Ofelt (JO) analysis. The emission spectra and con-focal photoluminescence images obtained by 410 nm laser excitation demonstrates very distinct and intense orange-red emission for all the doped glasses. The suitable concentration of Sm3+ ions in these glasses to act as an efficient lasing material has been discussed by measuring the emission cross-section and branching ratios for the emission transitions. The quantum efficiencies were also been estimated from emission decay measurements recorded for the 4G5/2 level of Sm3+ ions. From the measured emission cross-sections, branching ratios, strong photoluminescence features and CIE chromaticity coordinates, it was found that 1 mol% of Sm3+ ions doped ZnAlBiB glasses are most suitable for the development of visible orange-red lasers.

  9. Precipitation of ZnO in Al 2O 3-doped zinc borate glass ceramics

    Science.gov (United States)

    Masai, Hirokazu; Ueno, Takahiro; Takahashi, Yoshihiro; Fujiwara, Takumi

    2011-10-01

    Crystallization behavior of the oxide semiconductor ZnO in zinc borate glass was investigated. The precipitated crystalline phase of glass ceramics containing a small amount of Al 2O 3 was α-Zn 3B 2O 6 whereas that of the glass ceramics containing a large amount of Al 2O 3 was ZnO. It was found that the c-oriented precipitation of ZnO in a glass ceramic was brought about by the in-plane crystal growth of needle-like ZnO crystallites along the a-axis. Amount of Al 2O 3 that can make glass network affected the coordination state of B 2O 3 in the glass, and a three-coordinated BO 3 unit was preferentially formed in the glass containing a higher amount of Al 2O 3. The present results suggest that crystallization of ZnO from multi-component glass is dominated by the local coordination state of the mother glass.

  10. Waveguides and nonlinear index of refraction of borate glass doped with transition metals

    Science.gov (United States)

    Almeida, Juliana M. P.; Fonseca, Ruben D.; De Boni, Leonardo; Diniz, Andre Rosa S.; Hernandes, Antonio C.; Ferreira, Paulo H. D.; Mendonca, Cleber R.

    2015-04-01

    The ability to write 3D waveguides by femtosecond laser micromachining and the nonlinear refractive index (n2) spectrum of a new borate glass matrix, containing zinc and lead oxides - (BZP) have been investigated. The transparent matrix was doped with transition metals (CdCl2, Fe2O3, MnO2 and CoO) in order to introduce electronic transitions in visible spectrum, aiming to evaluate their influence on the waveguides and n2 spectrum. We observed that n2 is approximately constant from 600 to 1500 nm, exhibiting an average value of 4.5 × 10-20 m2/W, which is about twice larger than the one for fused silica. The waveguide profile is influenced by the self-focusing effect of the matrix owing to its positive nonlinear index of refraction in the wavelength used for micromachining. A decrease in the waveguide loss of approximately four times was observed for the sample doped with Fe in comparison to the other ones, which may be associated with the change in the optical gap energy.

  11. Tris(thioimidazolyl)borate-zinc-thiolate complexes for the modeling of biological thiolate alkylations.

    Science.gov (United States)

    Ibrahim, Mohamed M; Seebacher, Jan; Steinfeld, Gunther; Vahrenkamp, Heinrich

    2005-11-14

    The S3Zn-SR coordination of thiolate-alkylating enzymes such as the Ada DNA repair protein was reproduced in tris(thioimidazolyl)borate-zinc-thiolate complexes Tti(R)Zn-SR'. Four different Tti(R) ligands and nine different thiolates were employed, yielding a total of 12 new complexes. In addition, one Tti(R)Zn-SH complex and two thiolate-bridged [Tti(R)-SEt-Tti(R)]+ complexes were obtained. A selection of six thiolate complexes was converted with methyl iodide to the corresponding methyl thioethers and Tti(R)Zn-I. According to a kinetic analysis these reactions are second-order processes, which implies that the alkylations are likely to occur at the zinc-bound thiolates. They are much faster than the alkylations of zinc thiolates with N3 or N2S tripod ligands. The most reactive thiolate, Tti(Xyl)Zn-SEt, reacts slowly with trimethyl phosphate in a nonpolar medium at room temperature, yielding methyl-ethyl-thioether and Tti(Xyl)Zn-OPO(OMe)2 which can be converted back to the thiolate complex with NaSEt. This is the closest reproduction of the Ada repair process so far. PMID:16270993

  12. The Preparation and Characterization of Nd2O3 Doped Borate Glass

    International Nuclear Information System (INIS)

    The Nd3+ doped borate glass of Nd2O3-MgO-ZnO-B2O3 glass system is successfully been prepared by melt-quenched technique. Batches of 15g were prepared from certified reagent grades of B2O3(99.95% purity), MgO (97%), ZnO (98% purity), and Nd2O3(99.99%). The measured glass densities are found varies from 5683.2 kgm-3 to 5724.0 kgm-3. The increment in density implies that an addition of Nd2O3 with higher atomic masses than B2O3 tend to increase the packing density of the glass structures since the atomic masses of B2O3 and Nd2O3 are 69.62 and 336.42 respectively. From the density values obtained, the molar volume of glasses was calculated. From the results, it is found that the molar volume of these glasses decreases slightly from 22.50 cm3 to 27.54 cm3 with respect to Nd2O3 content.

  13. Absorption and emission properties of Ho3+ doped lead-zinc-borate glasses

    International Nuclear Information System (INIS)

    This paper reports on the affect of lead content on the absorption and emission spectra of the Ho3+ ion doped lead-zinc-borate glasses in the composition (mol%) of (20 - x)PbO-20ZnO-(59 + x)B2O3-1.0Ho2O3 where x 0, 5,10,15 of PbO content with λ exc = 405 nm. The experimental absorption band energies have satisfactorily been correlated with the theoretical results with an r.m.s deviation of zero with the following correction factors obtained by a least square fit analysis: ΔE 1 348.495936 cm-1, ΔE 2 = 1.436043 cm-1, ΔE 3 = 46.481575 cm-1, Δξ 4f = - 28.512979 cm-1, Δα = 55.508936 cm-1, Δβ = - 1394.339908 cm-1 and Δγ 1208.424336 cm-1. By applying the Judd-Ofelt intensity parameter Ω 2 has been found to be linearly decreasing with the PbO content from 5 to 10 mol% and then increasing. And also radiative (A, A T, β, τ r) characteristic factors of the luminescent transitions (5I8 5F3,4,5 and 5S2) of the glasses have been evaluated. Stimulated emission cross-sections (σ pE) of the measured emission transitions of holmium glasses have also been computed

  14. Dosimetric and kinetic parameters of lithium cadmium borate glasses doped with rare earth ions

    Directory of Open Access Journals (Sweden)

    J. Anjaiah

    2014-10-01

    Full Text Available Thermoluminescence (TL characteristics of X-ray irradiated pure and doped with four different rare earth ions (viz., Pr3+, Nd3+, Sm3+ and Eu3+ Li2O–Cdo–B2O3 glasses have been studied in the temperature range 303–573 K; the pure glass has exhibited single TL peak at 466 K. When this glass is doped with different rare earth ions no additional peaks are observed but the glow peak temperature of the existing glow peak shifted gradually towards higher temperatures with gain in intensity of TL light output. The area under the glow curve is found to be maximum for Eu3+ doped glasses. The trap depth parameters associated with the observed TL peaks have been evaluated using Chen's formulae. The possible use of these glasses in radiation dosimetry has been described. The result clearly showed that europium doped cadmium borate glass has a potential to be considered as the thermoluminescence dosimeter.

  15. Influence of europium (Eu3+) ions on the optical properties of silver lead borate glasses

    Indian Academy of Sciences (India)

    K Keshavamurthy; B Eraiah

    2015-09-01

    The influence of europium (Eu3+) ions on the optical properties of silver lead borate glasses of the Eu2O3–(1 – )Ag2O–29PbO–70B2O3 ( = 0, 0.1, 0.2, 0.3, 0.4 and 0.5 mol%) glass system prepared by the conventional melt quenching technique and their physical and optical properties were investigated. The UV absorption spectra were recorded at room temperature in the wavelength range of 200–600 nm. From the absorption edge data, it is found that both the direct and indirect transitions and their values are ranging from 3.19 to 3.54 and 2.50 to 3.07 eV, respectively. The Urbach energy values for these glasses were found to be in the range of 0.39–0.52 eV. The refractive indices have also been evaluated with respect to different molar concentrations of Eu2O3 and their calculated values are ranging from 1.598 to 1.654.

  16. Comparison of Lithium Gadolinium Borate Crystal Shards in Scintillating and Nonscintillating Plastic Matrices

    CERN Document Server

    Kazkaz, Kareem; Pedretti, Marisa

    2011-01-01

    We present a method for detecting neutrons using scintillating lithium gadolinium borate crystal shards in a plastic matrix while maintaining high gamma rejection. We have procured two cylindrical detectors, 5"\\times5", containing 1% crystal by mass. Crystal shards have a typical dimension of 1 mm. One detector was made with scintillating plastic, and one with nonscintillating plastic. Pulse shape analysis was used to reject gamma ray backgrounds. The scintillating detector was measured to have an intrinsic fast fission neutron efficiency of 0.4% and a gamma sensitivity of less than 2.3 \\times 10-9, while the nonscintillating detector had a neutron efficiency of 0.7% and gamma sensitivity of (4.75\\pm3.94)\\times10-9. We determine that increasing the neutron detection efficiency by a factor of 2 will make the detector competitive with moderated 3He tubes, and we discuss several simple and straightforward methods for obtaining or surpassing such an improvement. We end with a discussion of possible applications, ...

  17. Luminescence properties of Tm3+/Yb3+ codoped lead alumina bismuth borate glasses

    Science.gov (United States)

    Goud, K. Krishna Murthy; Reddy, M. Chandra Shekhar; Rao, B. Appa

    2016-05-01

    This paper reports on the spectroscopic properties of Yb3+ and Tm3+ codoped lead alumina bismuth borate glasses. Optical absorption spectra of these Samples were recorded at room temperature in the wavelength range 350-2000 nm. The absorption spectra exhibited the bands at 658 nm (3H6→3F2), 686 nm (3H6→3F3), 792 nm (3H6→3H4), 1211 nm (3H6→3H5) and 1663 nm (3H6→3F4) due to Tm3+ ions. The band at 977 nm (2F7/2→2F5/2) is due to Yb3+ ions. Optical band gap (Eopt) and Urbach energy (ΔE) values were calculated from the spectra. It was observed that the value of optical band gap decreases with increase in the concentration of Tm3+ ions. The upconversion luminescence spectra were measured under excitation of 980 nm laser diode, and the intense blue (470 nm) and green (656 nm) emission were simultaneously observed at room temperature. A proposed upconversion mechanism involving energy transfer from Yb3+ to Tm3+ has been presented.

  18. Tribological characteristics of monodispersed cerium borate nanospheres in biodegradable rapeseed oil lubricant

    Science.gov (United States)

    Boshui, Chen; Kecheng, Gu; Jianhua, Fang; Jiang, Wu; Jiu, Wang; Nan, Zhang

    2015-10-01

    Stearic acid-capped cerium borate composite nanoparticles, abbreviated as SA/CeBO3, were prepared by hydrothermal method. The morphologies, element compositions, size distributions, crystal and chemical structures, hydrophobic characteristics, of SA/CeBO3 were characterized by scanning electron microscope, energy dispersive X-ray spectrometer, dynamic laser particle size analyzer, X-ray diffraction, and Fourier transform infrared spectrometer, respectively. The friction and wear performances of SA/CeBO3 as a lubricating additive in a rapeseed oil were evaluated on a four-ball tribo-tester. The tribochemical characteristics of the worn surfaces were investigated by X-ray photoelectron spectroscopy. The results showed that the hydrophobic SA/CeBO3 were monodispersed nanospheres with an average diameter of 8 nm, and exhibited excellent dispersing stability in rapeseed oil. Meanwhile, SA/CeBO3 nanospheres were outstanding in enhancing friction-reducing and anti-wear capacities of rapeseed oil. The prominent tribological performances of SA/CeBO3 in rapeseed oil were attributed to the formation of a composite boundary lubrication film mainly composed of lubricous tribochemical species of B2O3, CeO2 and Fe2O3, and the adsorbates of SA/CeBO3 and rapeseed oil, on the tribo-surfaces.

  19. Response of a lithium gadolinium borate scintillator in monoenergetic neutron fields.

    Science.gov (United States)

    Williams, A M; Beeley, P A; Spyrou, N M

    2004-01-01

    Accurate estimation of neutron dose requires knowledge of the neutron energy distribution in the working environment. Existing neutron spectrometry systems, Bonner spheres for example, are large and bulky, and require long data acquisition times. A portable system that could indicate the approximate neutron energy spectrum in a short time would be extremely useful in radiation protection. A composite scintillator, consisting of lithium gadolinium borate crystals in a plastic scintillator matrix, produced by Photogenics is being tested for this purpose. A prototype device based on this scintillator and digital pulse processing electronics has been calibrated using quasi-monoenergetic neutron fields at the low-scatter facility of the UK National Physical Laboratory (NPL). Energies selected were 144, 250, 565, 1400, 2500 and 5000 keV, with correction for scattered neutrons being made using the shadow cone technique. Measurements were also made in the NPL thermal neutron field. Pulse distributions collected with the digitiser in capture-gated mode are presented, and detection efficiency and energy resolution derived. For comparison, neutron spectra were also collected using the commercially available Microspec N-Probe from Bubble Technology Industries, which consists of an NE213 scintillator and a 3He proportional counter.

  20. Ultrasonic investigations of some bismuth borate glasses doped with Al2O3

    Indian Academy of Sciences (India)

    Yasser B Saddeek; Moenis A Azooz; Amr Bakr Saddek

    2015-02-01

    The velocities of longitudinal and transverse ultrasonic waves in different compositions of 5Al2O3–29Na2O–(66−)B2O$_{3}−x$Bi2O3 glass system were measured at 4 MHz at room temperature using the pulse-echo technique. The velocity data were used to determine the elastic moduli and the dimensionality of the studied glasses. The observed changes in the elastic moduli of the glasses were related to the modifier role of Bi2O3 content. The results revealed that the density increased with increasing Bi2O3 content, which was attributed to the increase in the compactness and packing of the glass network. The ultrasonic data were analysed in terms of creation of new bonds of Bi2O3 attached to the structural units of the borate network. The new bonds decreased the average crosslink density and the number of network bonds per unit volume along with a weakening of the different modes of vibrations, which in its turn decreased the ultrasonic velocity. Quantitative analysis was carried out using Makishima–Mackenzie model in order to obtain more information about the rigidity of these glasses.

  1. New High Capacity Cathode Materials for Rechargeable Li-ion Batteries: Vanadate-Borate Glasses

    Science.gov (United States)

    Afyon, Semih; Krumeich, Frank; Mensing, Christian; Borgschulte, Andreas; Nesper, Reinhard

    2014-11-01

    V2O5 based materials are attractive cathode alternatives due to the many oxidation state switches of vanadium bringing about a high theoretical specific capacity. However, significant capacity losses are eminent for crystalline V2O5 phases related to the irreversible phase transformations and/or vanadium dissolution starting from the first discharge cycle. These problems can be circumvented if amorphous or glassy vanadium oxide phases are employed. Here, we demonstrate vanadate-borate glasses as high capacity cathode materials for rechargeable Li-ion batteries for the first time. The composite electrodes of V2O5 - LiBO2 glass with reduced graphite oxide (RGO) deliver specific energies around 1000 Wh/kg and retain high specific capacities in the range of ~ 300 mAh/g for the first 100 cycles. V2O5 - LiBO2 glasses are considered as promising cathode materials for rechargeable Li-ion batteries fabricated through rather simple and cost-efficient methods.

  2. Production of Zinc Borate for Pilot-Scale Equipment and Effects of Reaction Conditions on Yield

    Directory of Open Access Journals (Sweden)

    Melek BARDAKCI

    2013-05-01

    Full Text Available In this study, zinc borate (ZB was synthesized by reacting zinc oxide and boric acid in the presence of standard ZB (w/w, in terms of boric acid in order to promote crystallization. The effects of seed, H3BO3/ZnO (boric acid/zinc oxide ratio, reaction time, water volume, reaction temperature and cooling temperature on yield were investigated for pilot-scale equipment. The results indicated that the addition of seed (w/w to a saturated solution of reactants increased the yield of the reaction. The results of reaction yields obtained from either magnetically or mechanically stirred systems were compared. At various reaction times, the optimal yield was 86.78 % in a saturated aqueous solution. The products were characterized by X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FT-IR and Thermogravimetric / Differential Thermal Analysis (TG/DTA. The results displayed that ZB was successfully produced under the optimized reaction conditions and the product synthesized had high thermal stability.DOI: http://dx.doi.org/10.5755/j01.ms.19.2.4432

  3. Infrared luminescence and thermoluminescence of lithium borate glasses doped with Sm3+ ions

    Directory of Open Access Journals (Sweden)

    Anjaiah J.

    2015-03-01

    Full Text Available Thermoluminescence (TL characteristics of X-ray irradiated pure and doped with Sm3+ ions Li2O-MO-B2O3 (where MO=ZnO, CaO, CdO glasses have been studied in the temperature range of 303 to 573 K. All the pure glasses exhibited single TL peaks at 382 K, 424 K and 466 K. When these glasses were doped with Sm3+ ions no additional peaks have been observed but the glow peak temperature of the existing glow peak shifted gradually towards higher temperatures with gain in intensity of TL light output. The area under the glow curve was found to be maximum for Sm3+ doped glasses mixed with cadmium oxide as a modifier. The trap depth parameters associated with the observed TL peaks have been evaluated using Chen’s formulae. The possible use of these glasses in radiation dosimetry has been described. The results clearly showed that samarium doped cadmium borate glass has a potential to be considered as a thermoluminescence dosimeter.

  4. Low-Temperature Sintering and Microwave Dielectric Properties of Zn2SiO4 Ceramic Added with Crystalline Zinc Borate

    Science.gov (United States)

    Chaware, Varsha; Deshmukh, Ravindra; Sarode, Chetan; Gokhale, Suresh; Phatak, Girish

    2015-07-01

    The physical and dielectric properties of composites of known microwave materials, Zn2SiO4 and Zn3B2O6, prepared by solid-state reaction, were investigated with the purpose of developing a low-loss dielectric material for low-temperature co-fired ceramic applications. An off-stoichiometric phase of Zn2SiO4 with extra SiO2 was used to avoid the occurrence of unreacted ZnO. During sintering, zinc borate was found to partially react with residual SiO2 to form Zn2SiO4. The residual zinc borate was converted to a boron-rich glassy phase which helped to reduce the sintering temperature of the composite. Good relative sintering density (>90%) at temperatures below the melting temperature of zinc borate is indicative of a sintering mechanism of diffusion-based mass transfer. Composites containing 15 wt.% zinc borate, 2.5 wt.% lithium carbonate and 20 wt.% zinc borate in zinc silicate had dielectric constants of 6.8 and 6.1, quality factors (Q×f) of 48,800 and 94,300 GHz when sintered at 900°C and 950°C, respectively. These quality factor results are close to the best values reported for zinc silicate at these sintering temperatures.

  5. Structural insights for the design of new borate-phosphates: synthesis, crystal structure and optical properties of Pb₄O(BO₃)(PO₄) and Bi₄O₃(BO₃)(PO₄).

    Science.gov (United States)

    Wang, Ying; Pan, Shilie; Huang, Shengshi; Dong, Lingyun; Zhang, Min; Han, Shujuan; Wang, Xian

    2014-09-14

    Two new metal borate-phosphates, Pb4O(BO3)(PO4) (1) and Bi4O3(BO3)(PO4) (2), have been successfully designed and synthesized. The structures of the title compounds were determined by single-crystal X-ray diffraction. The title compounds have similar crystal structures consisting of oxygen-centered (OPb4) or (OBi4) tetrahedra as well as isolated BO3 and PO4 groups. Structural comparison and the Madelung energy calculation indicate that the title compounds also exhibit a strong correlation with the known metal borates and phosphates. In addition, a strategy of BO3-PO4 substitution is proposed for designing new borate-phosphates. Thermal analyses, IR spectroscopy and UV-vis-NIR diffuse reflectance spectroscopy have also been performed. PMID:25020047

  6. Photon-Induced Borate Groups Transformation by Femtosecond Laser%飞秒激光诱导硼酸盐基团的转变

    Institute of Scientific and Technical Information of China (English)

    杨晓燕; 余昺鲲; 姜雄伟; 曾慧丹

    2003-01-01

    In this paper, we put emphasis on the analysis the mechanism of the photon-induced frequency conversionβ-BaB2O4 crystal inside a borate glass using femtosecond laser. Because of the nature of femtosecond laser's ultra-short pulse duration and high-energy deusity, in essence the laser-glass interaction mechanism is changed. Based on multiphoton ionization, collisional ionization and the network depolymerization in the borate glass, production of the plasma drives the microstructure rearrangement near the laser beam focusing area. From the structure of glass and crystal analysis, we conclude that the complicated borate groups containing BO3 and BO4 units inside the glass are converted into(B3O6) 3 anion rings.

  7. Effect of TiO2 on the optical, structural and crystallization behavior of barium borate glasses

    Science.gov (United States)

    Marzouk, M. A.; ElBatal, F. H.; ElBatal, H. A.

    2016-07-01

    Collective characterizations of prepared binary barium borate glass (50 mol % BaO - 50 mol % B2O3) together with samples containing increasing added TiO2 contents (5% → 30%) were carried out by optical and FT infrared absorption measurements. FT infrared and X-ray diffraction analysis were done for heat treated glass - ceramic derivatives prepared through two step regime process. Optical spectra of the glasses reveal the presence of titanium ions mainly in the tetravalent state imparting additional UV band beside strong UV absorption due to trace iron impurity. IR spectral studies indicate the presence of triangular and tetrahedral borate groups through the modification of BaO to some BO3 to BO4 groups beside the presence of titanium ions as interfering or overlapping TiO4 or Bsbnd Osbnd Ti groupings in the glassy network. Crystalline X-ray diffraction results indicate the separation of crystalline barium borate of the composition (2BaO.5 B2O3) as a main constituent together with some crystalline alkali titanates confirming the role of TiO2 of both as nucleating agent beside acting as structural forming through reaction with alkali oxides to form crystalline titanates. The optical band gap values reveal progressive decrease and increase of Urbach energy with TiO2 content and the same for the refractive index values and all these parameters are correlated with the proposed changes in the glass constitution with the introduction of TiO2. The additional thermal expansion measurements indicate the peculiar characteristic negative expansion up to 300 °C and after which an increase in the coefficient of thermal expansion is identified with the increase in temperature. The thermal parameters are also correlated with the modification of the glass structure by the introduction of titanium ions.

  8. Comparative study on lithium borates as corrosion inhibitors of aluminum current collector in lithium bis(fluorosulfonyl)imide electrolytes

    Science.gov (United States)

    Park, Kisung; Yu, Sunghun; Lee, Chulhaeng; Lee, Hochun

    2015-11-01

    Lithium bis(fluorosulfonyl)imide (LiFSI) is a promising salt that can possibly overcome the limitations of lithium hexafluorophosphate (LiPF6) in current Li-ion batteries (LIBs). Aluminum (Al) corrosion issue, however, is a major bottleneck for the wide use of LiFSI. This study investigates lithium borate salts as Al corrosion inhibitors in LiFSI electrolytes. Through a systematic comparison among lithium tetrafluoroborate (LiBF4), lithium bis(oxalato)borate (LiBOB), and lithium difluoro(oxalato)borate (LiDFOB), and LiPF6, the inhibition ability of the additives is revealed to be in the following order: LiDFOB > LiBF4 ≈ LiPF6 > LiBOB. In particular, the inhibition effect of LiDFOB is outstanding; the anodic behavior of Al in 0.8 M LiFSI + 0.2 M LiDFOB ethylene carbonate (EC)-based electrolyte is comparable to that of corrosion-free 1 M LiPF6 solution. The superior inhibition ability of LiDFOB is attributed to the formation of a passive layer composed of Al-F, Al2O3, and B-O species, as evidenced by X-ray photoelectron spectroscopy (XPS) measurements. A LiCoO2/graphite cell with 0.8 M LiFSI + 0.2 M LiDFOB electrolyte exhibits a rate capability comparable to a cell with 1 M LiPF6 solution, whereas a cell with 0.8 M LiFSI solution without LiDFOB suffers from poor power performance resulting from severe Al corrosion.

  9. Reflectance spectroscopy of low atomic weight and Na-rich minerals: Borates, hydroxides, nitrates, nitrites, and peroxides

    Science.gov (United States)

    Cloutis, E.; Berg, B.; Mann, P.; Applin, D.

    2016-01-01

    We have measured reflectance spectra (0.35-20 μm) of a suite of minerals and synthetic compounds that contain low-Z (⩽Na) elements as the major cation and/or the major anion in oxides/oxyhydroxides, and are relevant to planetary geology and astrobiology. The suite comprises Na-borates, Na-, K-, Ca-hydroxides, nitrates, nitrites, and peroxides. Na-borate spectra exhibit B-O fundamental vibrations between 7 and 14 μm, and overtones/combinations of these bands in the 1.55, 1.75, 2.15, and 2.25 μm regions. Na-, K-, and Ca-hydroxide reflectance spectra are characterized by OH and metal-OH fundamental vibrations near 3, 8, and 18 μm, and a number of overtone and combination absorption bands at shorter wavelengths, and a characteristic metal-OH band near 2.35 μm. The nitrate and nitrite spectra exhibit fundamental N-O vibrations in the 7-14 μm region and numerous combinations and overtones that are still detectable to as low as ∼1.8 μm. Na-peroxide is largely spectrally featureless below 24 μm, making its detection problematic, while H-peroxide has many OH-related absorption features below 2.5 μm that differ in position from those of H2O ice and liquid. The results of this study indicate that the borates, hydroxides, nitrates, nitrite, and hydrogen peroxide can all be uniquely identified using characteristic absorption features that are present below 2.5 μm. However, some of these features are weak, and their detectability will depend on the types and abundances of any accessory phases that may be present.

  10. Synthesis, structural characterization and optical properties of a new cesium aluminum borate, Cs2Al2B2O7

    International Nuclear Information System (INIS)

    A new borate, Cs2Al2B2O7, was synthesized by solid-state reaction. It crystallizes in the monoclinic space group P21/c with a=6.719(1) Å, b=7.121(1) Å, c=9.626(3) Å, β=115.3(1)°, and Z=2. In the structure, two AlO4 tetrahedra and two BO3 planar triangles are connected alternately by corner-sharing to from nearly planar [Al2B2O10] rings, which are further linked via common O1 atom to generate layers in the bc plane. These layers then share the O3 atoms lying on a center of inversion to form a three-dimensional framework with Cs atoms residing in the channels. The IR spectrum confirms the presence of both BO3 and AlO4 groups and the UV–vis–IR diffuse reflectance spectrum indicates a band gap of about 4.13(2) eV. - Graphical abstract: A new borate, Cs2Al2B2O7, was synthesized. In the structure, BO3 triangles and AlO4 tetrahedra are connected to form a three-dimensional framework with Cs+ in the channels.▪ Highlights: ► A new borate Cs2Al2B2O7 was synthesized and crystals were obtained by flux method. ► Cs2Al2B2O7 crystallizes in a new structure type. ► Two AlO4 and two BO3 generate a [Al2B2O10] ring in the structure. ► Rings are linked to form a three-dimensional framework with Cs+ in the channels. ► Optical band gap is about 4.13 eV.

  11. Geochemical analysis of brine samples for exploration of Borate deposits in the South of Sabzevar

    Directory of Open Access Journals (Sweden)

    Mahdi Bemani

    2016-07-01

    Full Text Available Introduction Mohammad-abad Oryan is the only potential source of borate in the North-east of Iran located in 50 km South of Sabzevar. The area is located in tuff marl, tuffaceous marl, volcanic braccia and tuff braccia structures. Remote sensing techniques, geological studies and integration of this data in GIS were applied in an area of about 600 square kilometers to locate the promising areas of borate mineralization for detailed studies (Bemani, 2012. The aim of this detailed geochemical study is to confine the anomaly areas for exploratory drilling and trenching. Materials and methods Field studies were carried out in 9 geological traverses, mainly in Tonakar and Borje Kharkan area and 126 brine samples were taken from hydrothermal springs and 13 rock samples were taken from trenches. All the samples were analyzed for four elements, including B, K, Li and Mg. In order to determine the threshold quantities of the samples and isolation of anomaly, the data were analyzed using statistical methods including classical statistics, fractal geometry and EDA methods (Bemani, 2012. Result Initial data analysis showed that there were no censored data. Also, by applying statistical hypothesis testing, no significant relation was observed between the elements in the two areas (except for Li. Therefore, all the statistical analyses were carried out separately. After outlier correction, based on the amount of skewedness and histograms and probability plots of different elements, it became clear that none of the elements in the raw data distribution were normal and required to be transformed to be close to normal. In this study, logarithmic and three-parameter logarithm transformation were used in order to normalize the data . Based on the mean values, standard deviation of the normalized data, and background value and threshold, probable and possible anomalies were obtained and geochemical anomaly maps were drawn to identify the promising areas. With the

  12. Influence of zinc borate on the mechanical properties, inflammability and dripping behavior on carbonization of radiation cross linked PVC cable insulation

    International Nuclear Information System (INIS)

    Radiation cross linked flame retardant PVC cable insulation was developed utilizing suspension PVC as resin, and by incorporating the additives namely TMPTMA, TBLS, zinc stearate, a lubricant and antimony trioxide. Vacuum package insulated wires were the exposed to gamma irradiation to achieve the desired cross linking at doses varying 40 kGy to 80 kGy. Whereas limiting oxygen index (LOI) was higher than 30 and mechanical properties of the insulation irradiated to 60 and 80 kGy were in conformity with the international standards, the insulation on carbonization demonstrated dripping behavior. To introduce anti dripping characteristic zinc borate was selected as additive because of its known ability to impart anti dripping property presumably through the information of char. It was expected that the borate might as well exert some synergistic effect on the LOI of the resultant formulation. The influence of addition of varying amount of zinc borate was thus explored on the properties mentioned and anti dripping characteristic of the radiation cross linked insulation. No detrimental or adverse effect on mechanical properties of modified formulation was observed on addition of the borate. However, a steady increase in the LOI with the absence of any flare was observed with corresponding increase in the amount of the borate. The insulation also exhibited anti dripping property at the addition of 3 phr of zinc borate and above. The formulation also has enormous market opportunities for clothing, automobile seats and interior covering where dripping of ignited materials can ignite the other floor coverings etc especially in complex, high rise and underground buildings. (Author)

  13. Thermoluminescence and defect centres in Tb doped lithium magnesium borate phosphor

    Energy Technology Data Exchange (ETDEWEB)

    Menon, S.N., E-mail: sanju_n_m@yahoo.com [Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Trombay, Mumbai (India); Kadam, Sonal [Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Trombay, Mumbai (India); Watanabe, S.; Gundu Rao, T.K. [Institute of Physics, University of Sao Paulo, 05508-090 Sao Paulo, SP (Brazil); Kulkarni, M.S.; Babu, D.A.R. [Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Trombay, Mumbai (India)

    2015-11-15

    Terbium doped lithium magnesium borate phosphor exhibits thermoluminescence (TL) peaks at about 140 °C, 200 °C, 225 °C and 370 °C. The phosphor was characterized by X-ray powder diffraction and photoluminescence studies. Electron Spin Resonance (ESR) studies were carried out to identify the defect centres responsible for the TL peaks. Room temperature ESR spectrum of irradiated phosphor appears to be a superposition of two distinct centres. One of the centres (centre I) with principal g-value 2.0108 is identified as an O{sup −} ion and the centre correlates with the TL peak at 200 °C. Centre II with an isotropic g-factor 2.0029 is assigned to an F{sup +}-type centre (singly ionized oxygen vacancy) and is the likely recombination centre for the TL peaks at 200 °C and 225 °C. An additional defect centre is observed during thermal annealing experiments and this centre (assigned to F{sup +} centre) seems to originate from an F centre (oxygen vacancy with two electrons). This F centre may be related to the observed high temperature 370 °C TL peak in LiMgBO{sub 3}:Tb phosphor. - Highlights: • Powder phosphor of LiMgBO{sub 3}:Tb{sup 3+} was prepared by solid state diffusion method. • The phosphor exhibits a dominant emission at 545 nm ({sup 5}D{sub 4}→{sup 7}F{sub 5}) of the Tb{sup 3+} ion. • Electron Spin Resonance studies have been carried out to identify the defect centres responsible for the observed thermoluminescence peaks.

  14. Effect of CeO2 addition on electrical and optical properties of lithium borate glasses

    International Nuclear Information System (INIS)

    Rare earth (RE) ions play an important role in modern technology as an active ion in many optical materials. RE-doped glasses were used in many optical devices because of abundant number of the absorption and emission bands arising from the transitions between the RE elements energy levels. Among all rare earth, glasses containing CeO2 are extensively studied for scintillating applications. Radiation length of CeO2 containing lithium silicate glasses decreases and absorption edge in transmittance shift towards longer wavelength. In the present study an attempt has been made to verify similar results in borate containing glasses. Therefore glass series 15Li2O-xCeO2-(85''x)B2O3 where x= 0.25, 0.5, 0.75, 1 mol% was prepared by conventional melt quench technique. Their electrical and optical properties have been investigated. It is observed that the conductivity of these glasses decreases while density, glass transition temperature and refractive index increases with the addition of CeO2. The conductivity of the glasses is mostly controlled by the activation energy. Since the lithium fraction in the present series is kept constant, the decrease in conductivity for glasses may be attributed to the reduction in the number of available vacant sites for the mobile lithium ions when boron is substituted with CeO2. The radiation length was determined using density values and it was found to decrease with the addition of CeO2. The absorption coefficient a were determined near the absorption edge of different photon energy for all glass samples and plot of (αhν)1/2 Vs. hν (Tauc's plot) is shown. It is observed that the optical band gap energy (EgOpt) decreases with the addition of CeO2

  15. Visible luminescence characteristics of Sm{sup 3+} doped Zinc Alumino Bismuth Borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Swapna, K.; Mahamuda, Sk. [Department of Physics, K L University, Green Fields, Vaddeswaram 522502, AP (India); Rao, A. Srinivasa, E-mail: drsrallam@yahoo.co.in [Department of Physics, K L University, Green Fields, Vaddeswaram 522502, AP (India); Department of Applied Physics, Delhi Technological University, Delhi 110042 (India); Sasikala, T.; Moorthy, L. Rama [Department of Physics, S V University, Tirupathi 517502, AP (India)

    2014-02-15

    Zinc Alumino Bismuth Borate (ZnAlBiB) glasses at different compositions doped with 1 mol% of Sm{sup 3+} ions were prepared by using the melt quenching technique and investigated by XRD, optical absorption, emission and decay curve analysis to understand the visible luminescence of these glasses. From the absorption spectra the JO parameters are evaluated and are used to calculate the radiative properties such as transition probability, radiative lifetime, branching ratio and absorption cross-sections for various fluorescent levels of Sm{sup 3+} ions. The emission spectra of Sm{sup 3+} ions doped ZnAlBiB glasses show two intense emission bands {sup 4}G{sub 5/2}→{sup 6}H{sub 7/2} (orange) and {sup 4}G{sub 5/2}→{sup 6}H{sub 9/2} (red) for which the stimulated emission cross-section and branching ratios are evaluated to understand the potentiality of these materials as visible lasers. The decay profiles for the {sup 4}G{sub 5/2} fluorescent level of Sm{sup 3+} doped ZnAlBiB glasses have been recorded to measure the quantum efficiency (η) of these glasses. The strong visible emissions, large stimulated emission cross-sections, high branching ratios and good quantum efficiencies observed for the present ZnAlBiB glasses suggest the suitability of these glasses as laser and photonic devices operating in visible region. -- Highlights: • Sm{sup 3+} doped ZnAlBiB glasses have been synthesised using melt quenching technique. • JO theory has been applied to evaluate the radiative properties of Sm{sup 3+} doped ZnAlBiB glasses. • Emission cross-sections have been evaluated for the intense emission transitions. • Quantum efficiency of the ZnAlBiB glasses was measured to understand the suitability of these glasses for lasers.

  16. Reddish-orange emission from Pr{sup 3+} doped zinc alumino bismuth borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Mahamuda, Sk., E-mail: mahamuda.ss@gmail.com [Department of Physics, KL University, Green Fields, Vaddeswaram 522502, AP (India); Swapna, K., E-mail: kswapna80@gmail.com [Department of Physics, KL University, Green Fields, Vaddeswaram 522502, AP (India); Srinivasa Rao, A., E-mail: drsrallam@yahoo.co.in [Department of Physics, KL University, Green Fields, Vaddeswaram 522502, AP (India); Department of Applied Physics, Delhi Technological University, New Delhi 110042 (India); Sasikala, T.; Rama Moorthy, L. [Department of Physics, SV University, Tirupathi 517502, AP (India)

    2013-11-01

    Praseodymium doped Zinc Alumino Bismuth Borate (ZnAlBiB) glasses were prepared by melt quenching technique and characterized by optical absorption and emission studies. The glassy nature of these glasses has been confirmed through XRD spectral measurements. From the absorption spectra, the Judd–Ofelt intensity parameters Ω{sub λ} (λ=2, 4 and 6) and other radiative properties like transition probability (A{sub R}), radiative lifetimes (τ{sub R}) and branching ratios (β{sub R}) have been evaluated. Emission spectra were measured for different concentrations of Pr{sup 3+} ions doped glasses by exciting the glasses at 445 nm. The intensity of Pr{sup 3+} emission spectra increases from 0.1 to 1 mol% and beyond 1 mol% concentration quenching is observed. The suitable concentration of Pr{sup 3+} ions in ZnAlBiB glasses to act as a good lasing material at reddish-orange wavelength (604 nm) region has been discussed by measuring the emission cross-sections for the intense emission transition {sup 1}D{sub 2}→{sup 3}H{sub 4}. The CIE chromaticity co-ordinates were also evaluated from the emission spectra for all the glasses to understand the suitability of these materials for reddish-orange emission. From the measured emission cross-sections and CIE chromaticity co-ordinates, it was found that 1 mol% of Pr{sup 3+} is aptly suitable for the development of visible reddish-orange lasers.

  17. Visible luminescence characteristics of Sm3+ doped Zinc Alumino Bismuth Borate glasses

    International Nuclear Information System (INIS)

    Zinc Alumino Bismuth Borate (ZnAlBiB) glasses at different compositions doped with 1 mol% of Sm3+ ions were prepared by using the melt quenching technique and investigated by XRD, optical absorption, emission and decay curve analysis to understand the visible luminescence of these glasses. From the absorption spectra the JO parameters are evaluated and are used to calculate the radiative properties such as transition probability, radiative lifetime, branching ratio and absorption cross-sections for various fluorescent levels of Sm3+ ions. The emission spectra of Sm3+ ions doped ZnAlBiB glasses show two intense emission bands 4G5/2→6H7/2 (orange) and 4G5/2→6H9/2 (red) for which the stimulated emission cross-section and branching ratios are evaluated to understand the potentiality of these materials as visible lasers. The decay profiles for the 4G5/2 fluorescent level of Sm3+ doped ZnAlBiB glasses have been recorded to measure the quantum efficiency (η) of these glasses. The strong visible emissions, large stimulated emission cross-sections, high branching ratios and good quantum efficiencies observed for the present ZnAlBiB glasses suggest the suitability of these glasses as laser and photonic devices operating in visible region. -- Highlights: • Sm3+ doped ZnAlBiB glasses have been synthesised using melt quenching technique. • JO theory has been applied to evaluate the radiative properties of Sm3+ doped ZnAlBiB glasses. • Emission cross-sections have been evaluated for the intense emission transitions. • Quantum efficiency of the ZnAlBiB glasses was measured to understand the suitability of these glasses for lasers

  18. Tb3+ doped Zinc Alumino Bismuth Borate glasses for green emitting luminescent devices

    International Nuclear Information System (INIS)

    Zinc Alumino Bismuth Borate (ZnAlBiB) glasses doped with terbium (Tb3+) ions with a chemical composition 20ZnO–10Al2O3–(10−x)Bi2O3–60B2O3−xTb2O3 (x=0.1, 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 mol%) were prepared by a conventional melt quenching method and studied their optical absorption, photoluminescence and decay spectral properties. The Judd–Ofelt (J–O) parameters evaluated from the experimental oscillator strengths were used to measure the radiative properties for the prominent luminescent transitions of Tb3+ ions such as 5D4→7F6, 7F5, 7F4 and 7F3. The effect of Tb3+ ion concentration on the luminescence process observed in the visible region was discussed in detail. The emission spectra recorded for all the ZnAlBiB glasses doped with Tb3+ ions, show an intense peak in green region at 542 nm. The stimulated emission cross-section, branching ratios and quantum efficiency values evaluated for green emission (5D4→7F5) suggests the utility of these glasses for green luminescence applications. It was found that, within the concentration range investigated, 2.5 mol% of Tb3+ doped ZnAlBiB glass is most suitable for green luminescence applications at 542 nm in principle. - Highlights: • ZnAlBiB glasses doped with Tb3+ ions were prepared by a conventional melt quenching technique. • Judd–Ofelt and radiative properties are measured from the emission spectra. • Quantum efficiency of the ZnAlBiB glasses is measured by using radiative and measured lifetimes. • CIE Chromaticity co-ordinates are evaluated from emission spectra

  19. Luminescence characterization of Eu3+ doped Zinc Alumino Bismuth Borate glasses for visible red emission applications

    International Nuclear Information System (INIS)

    Zinc Alumino Bismuth Borate (ZnAlBiB) glasses doped with different concentrations of Eu3+ ions have been prepared by rapid melt quenching technique and characterized for their luminescence behavior through various spectroscopic techniques such as absorption, excitation, emission, decay profiles and confocal image measurements at room temperature. From the measured absorption spectra, the bonding parameters (δ) were evaluated to find the nature of bonding between Eu3+ ions with its surrounding ligands in these ZnAlBiB glasses. The emission spectra of Eu3+ ions in ZnAlBiB glasses excited at 410 nm (CW laser) show the characteristic of Eu3+ ions with more intense visible red emission corresponding to 5D0→7F2 transition. This intense visible red emission is further confirmed by the confocal luminescence images recorded for all the ZnAlBiB glasses. Judd–Ofelt (J–O) parameters estimated from the emission spectral information are used to estimate the important radiative properties such as transition probability (AR), branching ratios (βR) and emission-cross sections for the prominent emission levels. The large stimulated emission cross-sections and branching ratios observed for ZnAlBiB glasses suggest the utility of these glasses in visible red region of the electromagnetic spectrum. The CIE chromaticity coordinates evaluated from the emission spectra and the confocal images recorded for all the ZnAlBiB glasses also indicates that, these glasses at higher concentration of Eu3+ ions are aptly suitable for intense red emission at 613 nm corresponding to 5D0→7F2 transition. - Highlights: • ZnAlBiB glasses doped with Eu3+ ions were prepared by conventional melt quenching technique. • Radiative properties are measured from the emission spectra. • Quantum efficiency of the ZnAlBiB glasses is measured by using radiative and measured lifetimes. • CIE Chromaticity coordinates are evaluated from emission spectra

  20. Optical and thermal investigations on vanadyl doped zinc lithium borate glasses

    Directory of Open Access Journals (Sweden)

    Seema Dalal

    2015-09-01

    Full Text Available Using standard melt-quench technique, transition metal oxide (2 mol% of V2O5 doped glasses having composition xZnO·(30 − xLi2O·70B2O3 (x = 0, 2, 5, 7 and 10 are prepared. The density (D is measured using buoyancy and found to be lying between 2.21 and 2.45 g/cm3 with an increasing trend on substituting ZnO contents in place of Li2O. The theoretical optical basicity (Λth is calculated and found to increase with increasing inclusion of ZnO indicating an increase in the ionic character. The molar refraction (Rm, refractive index (nr and molar polarizability (αm are calculated and explained on the basis of structural changes. The optical absorption spectra have been used to evaluate the values of optical band gap (Eopt and band tailing parameter (B. It is observed that Eopt decreases with the increasing contents of ZnO in base glass matrix. The decrease in Eopt is an evidence of enhancement in the number of non-bridging oxygen atoms (NBOs thereby increasing the four-coordinated boron atoms. The as-quenched samples in bulk form are subjected to differential thermal analysis (DTA to assess the glass transition temperature (Tg, which is 476 °C for pure lithium borate glass. The variations suggest that the structure is being modified by the substitution of ZnO.

  1. Spectroscopic and structural investigations of Er3+ doped zinc bismuth borate glasses

    International Nuclear Information System (INIS)

    Highlights: ► Spectral properties of Er3+ doped zinc bismuth borate glasses have been analyzed. ► Judd–Ofelt intensity parameters have been evaluated from absorption bands. ► Red shift in peak wavelength with Bi2O3 is attributed to the nephlauxetic effect. ► The large value of σT reflects the suitability of glasses in amplifier devices. ► These glasses have high radiative quantum efficiency. - Abstract: Erbium doped glasses having composition 20ZnO·xBi2O3·(79.5 − x)B2O3 (15 ≤ x ≤ 35, x in mol%) were prepared by melt-quench technique. The spectroscopic properties were investigated using optical absorption and fluorescence spectra. The Judd–Ofelt intensity parameters, Ωλ (λ = 2, 4, 6) were determined from the spectral intensities of absorption bands in order to calculate the radiative transition probability (AR), radiative life time (τR), branching ratio (βR) for various excited luminescent states. Using the emission spectra, full width at half maximum (FWHM), stimulated emission cross-section (σe) and figure of merit (FOM) were evaluated. The high values of Judd–Ofelt parameters indicate a substantial mixing of other electronic configuration into the 4fN configuration by the random crystal field in the glasses. All the intensity parameters (Ωλ) decrease with increase in Bi2O3 content and the effect is found to be most pronounced for Ω2 values. The structural investigations of the glasses were carried out by recording the IR transmission spectra. A correlation between the network forming units with the multi-phonon relaxation rate and hence with the possibility of radiative quantum efficiency has been made. In addition, various physical and optical parameters have been determined from the measured density and refractive index values.

  2. Preparation and Tribological Behavior of Hydrophobic Lanthanum Borate Nanosheets in Rapeseed Oil

    Institute of Scientific and Technical Information of China (English)

    Gu Kecheng; Chen Boshui; Xue Ming; Wang Jiu; Fang Jianhua; Wu Jiang

    2016-01-01

    Oleic acid-capped lanthanum borate (abbreviated as OA/LaBO3·H2O) nanosheets were prepared by the hydrothermal method. The microstructures of as-prepared OA/LaBO3·H2O were characterized by means of SEM, TEM, EDS, FTIR and XRD, respectively. Moreover, the friction and wear properties of OA/LaBO3·H2O as a lubricant additive in rapeseed oil were evaluated on a four-ball tribotester. The tribochemical characteristics of worn surfaces were investigated by SEM and XPS. The results showed that the hydrophobic OA/LaBO3·H2O nanosheets exhibited their morphology with a diameter in the range of 100 nm to 300 nm and a thickness of about 25 nm, and displayed excellent dispersing stability in rapeseed oil. In the meantime, the rapeseed oil doped with OA/LaBO3·H2O nanosheets markedly decreased the friction and wear of steel balls, and the optimal friction-reducing and antiwear ability of rapeseed oil was obtained at an OA/LaBO3·H2O content of 1.0%. The outstanding tribological performance of OA/LaBO3·H2O in rapeseed oil was attributed to the formation of a composite boundary lubrication iflm mainly composed of lubricious tribochemical species of B2O3, La2O3 and Fe2O3, and deposits of OA/LaBO3·H2O nanosheets as well as the adsorbates of rapeseed oil on rubbed surfaces.

  3. INVESTIGATION OF STRUCTURE-FORMATION MECHANISMS IN DIFFUSION BORATING OF WASTES WHILE PRODUCING STEEL AND IRON SHOT

    Directory of Open Access Journals (Sweden)

    E. F. Panteleenko

    2009-01-01

    Full Text Available The paper describes development of new composite self-fluxing powders made of waste products while  producing  cast steel and iron shot.  Structure  and  properties  of  initial  and  borated  powders, dependence of boride layer thickness growth on chemical and thermal treatment time have been investigated in the paper. The paper proposes for the first time a description of structure-formation mechanism in the diffusion alloying process on the basis of the obtained data.

  4. INVESTIGATION OF STRUCTURE-FORMATION MECHANISMS IN DIFFUSION BORATING OF WASTES WHILE PRODUCING STEEL AND IRON SHOT

    OpenAIRE

    E. F. Panteleenko

    2014-01-01

    The paper describes development of new composite self-fluxing powders made of waste products while  producing  cast steel and iron shot.  Structure  and  properties  of  initial  and  borated  powders, dependence of boride layer thickness growth on chemical and thermal treatment time have been investigated in the paper. The paper proposes for the first time a description of structure-formation mechanism in the diffusion alloying process on the basis of the obtained data.

  5. In vitro study of improved wound-healing effect of bioactive borate-based glass nano-/micro-fibers

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Qingbo [Department of Chemistry, Missouri University of Science and Technology, Rolla, MO 65409 (United States); Center for Biomedical Science and Engineering (CBSE), Missouri University of Science and Technology, Rolla, MO 65409 (United States); Center for Single Nanoparticle, Single Cell and Single Molecule Monitoring (CS3M), Missouri University of Science and Technology, Rolla, MO 65409 (United States); Chen, Sisi [Department of Chemistry, Missouri University of Science and Technology, Rolla, MO 65409 (United States); Center for Biomedical Science and Engineering (CBSE), Missouri University of Science and Technology, Rolla, MO 65409 (United States); Shi, Honglan [Department of Chemistry, Missouri University of Science and Technology, Rolla, MO 65409 (United States); Center for Biomedical Science and Engineering (CBSE), Missouri University of Science and Technology, Rolla, MO 65409 (United States); Center for Single Nanoparticle, Single Cell and Single Molecule Monitoring (CS3M), Missouri University of Science and Technology, Rolla, MO 65409 (United States); Xiao, Hai [Department of Electrical and Computer Engineering, Clemson University, Clemson, SC 29634 (United States); Ma, Yinfa, E-mail: yinfa@mst.edu [Department of Chemistry, Missouri University of Science and Technology, Rolla, MO 65409 (United States); Center for Biomedical Science and Engineering (CBSE), Missouri University of Science and Technology, Rolla, MO 65409 (United States); Center for Single Nanoparticle, Single Cell and Single Molecule Monitoring (CS3M), Missouri University of Science and Technology, Rolla, MO 65409 (United States)

    2015-10-01

    Because of the promising wound-healing capability, bioactive glasses have been considered as one of the next generation hard- and soft-tissue regeneration materials. The lack of understanding of the substantial mechanisms, however, indicates the need for further study on cell–glass interactions to better interpret the rehabilitation capability. In the present work, three bioactive glass nano-/micro-fibers, silicate-based 45S5, borate-based 13-93B3 and 1605 (additionally doped with copper oxide and zinc oxide), were firstly compared for their in vitro soaking/conversion rate. The results of elemental monitoring and electron microscopic characterization demonstrated that quicker ion releasing and glass conversion occurred in borate-based fibers than that of silicate-based one. This result was also reflected by the formation speed of hydroxyapatite (HA). This process was further correlated with original boron content and surrounding rheological condition. We showed that an optimal fiber pre-soaking time (or an ideal dynamic flow rate) should exist to stimulate the best cell proliferation and migration ability. Moreover, 13-93B3 and 1605 fibers showed different glass conversion and biocompatibility properties as well, indicating that trace amount variation in composition can also influence fiber's bioactivity. In sum, our in vitro rheological module closely simulated in vivo niche environment and proved a potentially improved wound-healing effect by borate-based glass fibers, and the results shall cast light on future improvement in bioactive glass fabrication. - Highlights: • Bioactive glass nano-/micro-materials were effectively used for tissue wound healing. • The wound-healing effects of silicate-based 45S5, borate-based 13-93B3 and 1605 fibers were investigated. • Glass conversion rates were compared under either static or dynamic-flow modes. • Glass compositions and flow rates greatly influenced bioactivity and cell migration. • These results can

  6. Luminescent thermochromism in potassium-alumina-borate glass with copper-containing molecular clusters at elevated temperatures

    Science.gov (United States)

    Babkina, Anastasiya N.; Nikonorov, Nikolaij V.; Shakhverdov, Teimur A.; Shirshnev, Pavel S.; Sidorov, Alexander I.

    2014-02-01

    It is experimentally shown that a considerable luminescent thermochromic effect occurs in potassium-alumina-borate (PAB) glasses with copper-containing molecular clusters. This effect is manifested in a reversible blue spectral shift of luminescence band about 100 nm and its narrowing, with negligible change of luminescence amplitude in maximum during heating from 20 up to 300 °C. Luminescence and excitation spectra of PAB glass at different temperatures are presented. It is shown that the temperature rise results in a red spectral shift of excitation bands and in their broadening.

  7. Bismuth and zinc double borate in Bi2O3-B2O3-ZnO system

    International Nuclear Information System (INIS)

    On the basis of DTA and X-ray phase analysis data phase diagram of 2Bi2O3xB2O3-ZnO system is plotted. Bismuth and zinc double borate 2Bi2O3xZnOxB2O3 is stated to be formed. It belongs to a monoclinic crystal system. All elementary cell parameters: a=16.43(8), b=10.27(6), c=5.607(3) A, β=95 ± 1, z=4 are determined

  8. In vitro study of improved wound-healing effect of bioactive borate-based glass nano-/micro-fibers

    International Nuclear Information System (INIS)

    Because of the promising wound-healing capability, bioactive glasses have been considered as one of the next generation hard- and soft-tissue regeneration materials. The lack of understanding of the substantial mechanisms, however, indicates the need for further study on cell–glass interactions to better interpret the rehabilitation capability. In the present work, three bioactive glass nano-/micro-fibers, silicate-based 45S5, borate-based 13-93B3 and 1605 (additionally doped with copper oxide and zinc oxide), were firstly compared for their in vitro soaking/conversion rate. The results of elemental monitoring and electron microscopic characterization demonstrated that quicker ion releasing and glass conversion occurred in borate-based fibers than that of silicate-based one. This result was also reflected by the formation speed of hydroxyapatite (HA). This process was further correlated with original boron content and surrounding rheological condition. We showed that an optimal fiber pre-soaking time (or an ideal dynamic flow rate) should exist to stimulate the best cell proliferation and migration ability. Moreover, 13-93B3 and 1605 fibers showed different glass conversion and biocompatibility properties as well, indicating that trace amount variation in composition can also influence fiber's bioactivity. In sum, our in vitro rheological module closely simulated in vivo niche environment and proved a potentially improved wound-healing effect by borate-based glass fibers, and the results shall cast light on future improvement in bioactive glass fabrication. - Highlights: • Bioactive glass nano-/micro-materials were effectively used for tissue wound healing. • The wound-healing effects of silicate-based 45S5, borate-based 13-93B3 and 1605 fibers were investigated. • Glass conversion rates were compared under either static or dynamic-flow modes. • Glass compositions and flow rates greatly influenced bioactivity and cell migration. • These results can

  9. Investigation of Gamma and Neutron Shielding Parameters for Borate Glasses Containing NiO and PbO

    OpenAIRE

    Singh, Vishwanath P.; Badiger, N. M.

    2014-01-01

    The mass attenuation coefficients, μ/ρ, half-value layer, HVL, tenth-value layer, TVL, effective atomic numbers, ZPIeff, and effective electron densities, Ne,eff, of borate glass sample systems of (100-x-y) Na2B4O7 : xPbO : yNiO (where x and y=0, 2, 4, 6, 8, and 10 weight percentage) containing PbO and NiO, with potential gamma ray and neutron shielding applications, have been investigated. The gamma ray interaction parameters, μ/ρ, HVL, TVL, ZPIeff, and Ne,eff, were computed for photon energ...

  10. Preparation and Anti-wear and Friction-reducing Properties of Barium Borate Modified with Dodecoxyl Group

    Institute of Scientific and Technical Information of China (English)

    Zeng Xiaojun; Li Fenfang; Zhou Maolin

    2007-01-01

    A novel lubricating oil additive dodecoxyl barium borate was synthesized.The product was characterized by FTIR,elemental analysis,thermo-gravimetric analysis(TGA),and scanning electron microscopy(SEM).Four-ball tests showed that the addition of a certain concentration of the additive to rapeseed oil could effectively increase both the load-carrying capacity(PB value),resistance to wear,and friction-reducing abilities.SEM observations confirmed that the additive could result in a reduced diameter of the wear scar.

  11. Caractérisation de nouveaux borates pour le doublage de fréquence aux longueurs d'ondes VUV : endommagement optique

    OpenAIRE

    Bourezzou, Mourad

    2013-01-01

    The purpose of my thesis, performed within the program of the ANR UV-Borate, was integrated in the UV-Conversion project certified by 2 poles of competitiveness (Matériala - Lorraine - and Route des lasers - Aquitaine -). The project concerned the study of borates YxLaySc4-(x+y)(BO3)4 (LYSB) and YAl3(BO3)4 (YAB), Non-Linear Optical (NLO) crystals which have the same crystallographic structure (R32). The growth of the crystals was realized by industrials and academics collaborators of the ANR....

  12. In vitro evaluation of borate-based bioactive glass scaffolds prepared by a polymer foam replication method

    International Nuclear Information System (INIS)

    Borate-based bioactive glass scaffolds with a microstructure similar to that of human trabecular bone were prepared using a polymer foam replication method, and evaluated in vitro for potential bone repair applications. The scaffolds (porosity = 72 ± 3%; pore size = 250-500 μm) had a compressive strength of 6.4 ± 1.0 MPa. The bioactivity of the scaffolds was confirmed by the formation of a hydroxyapatite (HA) layer on the surface of the glass within 7 days in 0.02 M K2HPO4 solution at 37 deg. C. The biocompatibility of the scaffolds was assessed from the response of cells to extracts of the dissolution products of the scaffolds, using assays of MTT hydrolysis, cell viability, and alkaline phosphatase activity. For boron concentrations below a threshold value (0.65 mM), extracts of the glass dissolution products supported the proliferation of bone marrow stromal cells, as well as the proliferation and function of murine MLO-A5 cells, an osteogenic cell line. Scanning electron microscopy showed attachment and continuous increase in the density of MLO-A5 cells cultured on the surface of the glass scaffolds. The results indicate that borate-based bioactive glass could be a potential scaffold material for bone tissue engineering provided that the boron released from the glass could be controlled below a threshold value.

  13. Chemical stability of seven years aged cement-PET composite waste form containing radioactive borate waste simulates

    Energy Technology Data Exchange (ETDEWEB)

    Saleh, H.M., E-mail: hosamsaleh70@yahoo.com [Radioisotope Department, Atomic Energy Authority, Dokki (Egypt); Tawfik, M.E. [Department of Polymers and Pigments, National Research Center, Dokki (Egypt); Bayoumi, T.A. [Radioisotope Department, Atomic Energy Authority, Dokki (Egypt)

    2011-04-15

    Different samples of radioactive borate waste simulate [originating from pressurized water reactors (PWR)] have been prepared and solidified after mixing with cement-water extended polyester composite (CPC). The polymer-cement composite samples were prepared from recycled poly (ethylene terephthalate) (PET) waste and cement paste (water/cement ratio of 40%). The prepared samples were left to set at room temperature (25 deg. C {+-} 5) under humid conditions. After 28 days curing time the obtained specimens were kept in their molds to age for 7 years under ambient conditions. Cement-polymer composite waste form specimens (CPCW) have been subjected to leach tests for both {sup 137}Cs and {sup 60}Co radionuclides according to the method proposed by the International Atomic Energy Agency (IAEA). Leaching tests were justified under various factors that may exist within the disposal site (e.g. type of leachant, surrounding temperature, leachant behavior, the leachant volume to CPCW surface area...). The obtained data after 260 days of leaching revealed that after 7 years of aging the candidate cement-polymer composite (CPC) containing radioactive borate waste samples are characterized by adequate chemical stability required for the long-term disposal process.

  14. Er-doped lead borate glasses and transparent glass ceramics for near-infrared luminescence and up-conversion applications.

    Science.gov (United States)

    Pisarski, Wojciech A; Goryczka, Tomasz; Pisarska, Joanna; Ryba-Romanowski, Witold

    2007-03-15

    Lead borate based glasses have been analyzed using Raman and infrared spectroscopy. The formation of different borate groups and the direction of BO3 BO4 conversion strongly depends on the PbO- and/or PbF2-to-B2O3 ratio in chemical composition. PbF2-PbO-B2O3 based glasses containing Er3+ ions have been studied after annealing. The orthorhombic PbF2 crystallites are formed during thermal treatment, which was evidenced by X-ray diffraction analysis. Near-infrared luminescence at 1530 nm and green up-conversion at 545 nm have been registered for samples before and after annealing. The luminescence bands correspond to 4I13/2-4I15/2 and 4S3/2-4I15/2 transitions of Er3+ ions, respectively. In comparison to the precursor glasses, the luminescence intensities are higher in the studied transparent oxyfluoride glass ceramics. Simultaneously, the half-width of the luminescence lines slightly decreases. It can be the evidence that a small amount of the Er3+ ions is incorporated into the orthorhombic PbF2 phase. PMID:17302452

  15. Formation of Rhamnogalacturonan II-Borate Dimer in Pectin Determines Cell Wall Thickness of Pumpkin Tissue1

    Science.gov (United States)

    Ishii, Tadashi; Matsunaga, Toshiro; Hayashi, Noriko

    2001-01-01

    Boron (B) deficiency results in inhibition of pumpkin (Cucurbia moschata Duchesne) growth that is accompanied by swelling of the cell walls. Monomeric rhamnogalacturonan II (mRG-II) accounted for 80% to 90% of the total RG-II in B-deficient walls, whereas the borate ester cross-linked RG-II dimer (dRG-II-B) accounted for more than 80% of the RG-II in control plants. The results of glycosyl residue and glycosyl linkage composition analyses of the RG-II from control and B-deficient plants were similar. Thus, B deficiency does not alter the primary structure of RG-II. The addition of 10B-enriched boric acid to B-deficient plants resulted within 5 h in the conversion of mRG-II to dRG-II-10B. The wall thickness of the 10B-treated plants and control plants was similar. The formation and possible functions of a borate ester cross-linked RG-II in the cell walls are discussed. PMID:11500567

  16. The effect of V 2O 5 on alkaline earth zinc borate glasses studied by EPR and optical absorption

    Science.gov (United States)

    Sumalatha, B.; Omkaram, I.; Rajavardhana Rao, T.; Linga Raju, Ch.

    2011-12-01

    10 wt% SrO:30 wt% ZnO:60 wt% B 2O 3 incorporated with different vanadyl concentrations were studied by means of electron paramagnetic resonance (EPR) and optical absorption techniques. The spin-Hamiltonian parameters ( g and A), bonding parameters ( α2 and β2∗2) and Fermi contact interaction parameter K have been calculated. The values of spin-Hamiltonian parameters indicate that the VO 2+ ions in strontium zinc borate glasses were present in octahedral sites with tetragonal compression. The spin concentration ( N) participating in resonance was calculated as a function of temperature (93-273 K) for strontium zinc borate glass sample containing 0.9 wt% of VO 2+ ions and the activation energy ( Ea) was calculated. From the EPR data, the paramagnetic susceptibility ( χ) was calculated at various temperatures and the Curie constant ( C) was evaluated from the 1/ χ- T graph. The optical absorption spectra of VO 2+ ions in these glasses show two bands corresponding to the transitions 2B 2g → 2B 1g and 2B 2g → 2E g in the order of decreasing energy respectively. The optical band gap energies ( Eopt) and Urbach energy (Δ E) have been determined from their ultraviolet edges. The theoretical values of optical basicity ( Λth) of these glasses have also been evaluated.

  17. Microwave Absorption of Barium Borosilicate, Zinc Borate, Fe-Doped Alumino-Phosphate Glasses and Its Raw Materials

    Directory of Open Access Journals (Sweden)

    Ashis Kumar Mandal

    2015-05-01

    Full Text Available This study presents microwave absorption of raw materials used in barium borosilicate, Fe-doped alumina phosphate and zinc borate glass. Microwave absorption was investigated for the raw materials SiO2, Na2CO3, BaCO3, BPO4, Al(PO33, Mg(PO32, Al(OH3, TiO2. The study shows that SiO2 could be heated directly above 1000 °C within 30 min at 1.5 kW microwave output (MW power and 0.8 kW MW power is necessary to initiate heating (from 260 °C. Microwave heating of material with low dielectric loss has been investigated by increasing MW power. Microwave absorption of above glass systems has also been investigated. Dielectric properties such as loss tangent of glass as a function of temperature are presented. Glass melting under direct microwave heating was demonstrated for the studied glass systems. Temperature-Microwave power-Time (T-P-t profiles for the three glasses indicate maximum MW output power ~1 kW, 0.65 kW and ~1 kW for barium borosilicate, zinc borate glass and alumino-phosphate glass for 60 g glass melting.

  18. In-situ Quasi-Instantaneous e-beam Driven Catalyst-Free Formation Of Crystalline Aluminum Borate Nanowires.

    Science.gov (United States)

    Gonzalez-Martinez, Ignacio G; Gemming, Thomas; Mendes, Rafael; Bachmatiuk, Alicja; Bezugly, Viktor; Kunstmann, Jens; Eckert, Jürgen; Cuniberti, Gianaurelio; Rümmeli, Mark H

    2016-01-01

    The catalyst-assisted nucleation and growth mechanisms for many kinds of nanowires and nanotubes are pretty well understood. At times, though, 1D nanostructures form without a catalyst and the argued growth modes have inconsistencies. One such example is the catalyst-free growth of aluminium borate nanowires. Here we develop an in-situ catalyst-free room temperature growth route for aluminium nanowires using the electron beam in a transmission electron microscope. We provide strong experimental evidence that supports a formation process that can be viewed as a phase transition in which the generation of free-volume induced by the electron beam irradiation enhances the atomic mobility within the precursor material. The enhanced atomic mobility and specific features of the crystal structure of Al5BO9 drive the atomic rearrangement that results in the large scale formation of highly crystalline aluminium borate nanowires. The whole formation process can be completed within fractions of a second. Our developed growth mechanism might also be extended to describe the catalyst-free formation of other nanowires. PMID:26934833

  19. Simultaneous pollutant removal and electricity generation in denitrifying microbial fuel cell with boric acid-borate buffer solution.

    Science.gov (United States)

    Chen, Gang; Zhang, Shaohui; Li, Meng; Wei, Yan

    2015-01-01

    A double-chamber denitrifying microbial fuel cell (MFC), using boric acid-borate buffer solution as an alternative to phosphate buffer solution, was set up to investigate the influence of buffer solution concentration, temperature and external resistance on electricity generation and pollutant removal efficiency. The result revealed that the denitrifying MFC with boric acid-borate buffer solution was successfully started up in 51 days, with a stable cell voltage of 205.1 ± 1.96 mV at an external resistance of 50 Ω. Higher concentration of buffer solution favored nitrogen removal and electricity generation. The maximum power density of 8.27 W/m(3) net cathodic chamber was obtained at a buffer solution concentration of 100 mmol/L. An increase in temperature benefitted electricity generation and nitrogen removal. A suitable temperature for this denitrifying MFC was suggested to be 25 °C. Decreasing the external resistance favored nitrogen removal and organic matter consumption by exoelectrogens.

  20. On the role of the network modifier PbO in Sm{sup 3+}-doped borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Krause, S., E-mail: stephan.krause@csp.fraunhofer.de [Fraunhofer Center for Silicon Photovoltaics CSP, Otto-Eißfeldt-Straße 12, 06120 Halle (Saale) (Germany); Pfau, C. [Centre for Innovation Competence SiLi-nano, Martin Luther University of Halle-Wittenberg, Karl-Freiherr-von-Fritsch-Straße 3, 06120 Halle (Saale) (Germany); Dyrba, M. [Fraunhofer Center for Silicon Photovoltaics CSP, Otto-Eißfeldt-Straße 12, 06120 Halle (Saale) (Germany); Centre for Innovation Competence SiLi-nano, Martin Luther University of Halle-Wittenberg, Karl-Freiherr-von-Fritsch-Straße 3, 06120 Halle (Saale) (Germany); Miclea, P.-T. [Fraunhofer Center for Silicon Photovoltaics CSP, Otto-Eißfeldt-Straße 12, 06120 Halle (Saale) (Germany); Institute of Physics, Martin Luther University of Halle-Wittenberg, 06120 Halle (Saale) (Germany); Schweizer, S. [Fraunhofer Center for Silicon Photovoltaics CSP, Otto-Eißfeldt-Straße 12, 06120 Halle (Saale) (Germany); Department of Electrical Engineering, South Westphalia University of Applied Sciences, Lübecker Ring 2, 59494 Soest (Germany)

    2014-07-01

    A series of Sm{sup 3+}-doped lead borate glasses with a lead oxide (PbO) content varying from 20 mol% to 80 mol% and a samarium oxide (Sm{sub 2}O{sub 3}) content of 1 mol% is investigated. In addition to the network changes in the glass structure, the lead doping has a significant influence on the fluorescence properties of Sm{sup 3+} and on the tuneable intrinsic fluorescence of Pb{sup 2+} itself. The Pb{sup 2+} excitation band shifts monotonously to lower energies; its intensity is significantly reduced for a PbO content of 50 mol% and more. For a concentration of 30 mol%, the Pb{sup 2+} emission overlaps with the intense {sup 6}H{sub 5/2} to {sup 6}P{sub 5/2} Sm{sup 3+} excitation band enabling for radiative and non-radiative energy transfers. Lifetime measurements of excited Sm{sup 3+} show in all cases non-single exponential decay and were fitted by the Inokuti–Hirayama model indicating non-radiative dipole–dipole interaction between neighbouring Sm{sup 3+} ions. - Highlights: • Tunable intrinsic fluorescence in lead borate glasses. • Energy transfer between the network modifier Pb{sup 2+} and Sm{sup 3+}. • Cut-off energy shifts with increasing PbO content.

  1. In vitro evaluation of borate-based bioactive glass scaffolds prepared by a polymer foam replication method

    Energy Technology Data Exchange (ETDEWEB)

    Fu Hailuo, E-mail: fuhailuo@hotmail.com [Department of Materials Science and Engineering, Missouri University of Science and Technology, Rolla, MO 65409 (United States); Institute of Bio-Engineering and IT Materials, Tongji University, Shanghai 200092 (China); Fu Qiang, E-mail: fuharry@hotmail.com [Department of Materials Science and Engineering, Missouri University of Science and Technology, Rolla, MO 65409 (United States); Zhou Nai [Institute of Bio-Engineering and IT Materials, Tongji University, Shanghai 200092 (China); Huang Wenhai, E-mail: whhuang@mail.tongji.edu.cn [Institute of Bio-Engineering and IT Materials, Tongji University, Shanghai 200092 (China); Rahaman, Mohamed N. [Department of Materials Science and Engineering, Missouri University of Science and Technology, Rolla, MO 65409 (United States); Wang Deping [Institute of Bio-Engineering and IT Materials, Tongji University, Shanghai 200092 (China); Liu Xin [Department of Materials Science and Engineering, Missouri University of Science and Technology, Rolla, MO 65409 (United States); Institute of Bio-Engineering and IT Materials, Tongji University, Shanghai 200092 (China)

    2009-08-31

    Borate-based bioactive glass scaffolds with a microstructure similar to that of human trabecular bone were prepared using a polymer foam replication method, and evaluated in vitro for potential bone repair applications. The scaffolds (porosity = 72 {+-} 3%; pore size = 250-500 {mu}m) had a compressive strength of 6.4 {+-} 1.0 MPa. The bioactivity of the scaffolds was confirmed by the formation of a hydroxyapatite (HA) layer on the surface of the glass within 7 days in 0.02 M K{sub 2}HPO{sub 4} solution at 37 deg. C. The biocompatibility of the scaffolds was assessed from the response of cells to extracts of the dissolution products of the scaffolds, using assays of MTT hydrolysis, cell viability, and alkaline phosphatase activity. For boron concentrations below a threshold value (0.65 mM), extracts of the glass dissolution products supported the proliferation of bone marrow stromal cells, as well as the proliferation and function of murine MLO-A5 cells, an osteogenic cell line. Scanning electron microscopy showed attachment and continuous increase in the density of MLO-A5 cells cultured on the surface of the glass scaffolds. The results indicate that borate-based bioactive glass could be a potential scaffold material for bone tissue engineering provided that the boron released from the glass could be controlled below a threshold value.

  2. Investigation of luminescence and spectroscopic properties of Nd3+ions in cadmium alkali borate glasses

    Science.gov (United States)

    Mohan, Shaweta; Thind, Kulwant Singh

    2016-07-01

    Neodymium doped cadmium alkali borate glasses having composition 20CdOsbnd 20R2Osbnd 59.5H3BO3sbnd 0.5Nd2O3; (R = Li, Na and K) were prepared by conventional melt-quenching technique. The amorphous nature of the glasses was confirmed by X-ray diffraction studies. The physical properties such as density, refractive index, molar volume, rare earth ion concentration etc. were determined. Optical absorption and fluorescence spectra were recorded. The Judd-Ofelt theory was applied on the optical absorption spectra of the glasses to evaluate the three phenomenological intensity parameters Ω2, Ω4 and Ω6. These parameters were in turn used to predict the radiative properties such as the radiative transition probability (A), radiative lifetime (τR) and branching ratio (βR) for the fluorescent levels of Nd3+ ion in the present glass series. The lasing efficiency of the prepared glasses has been characterized by the spectroscopic quality factor (Ω4/Ω6), the value of which is in the range of 0.2-1.5, typical for Nd3+ in different laser hosts. The variation of Ω2 with the change in alkali oxide has been attributed to the changes in the asymmetry of the ligand field at the rare earth ion site. The shift of the hypersensitive bands, study of the oscillator strengths and the variation of the spectral profile of the transition 4I9/2 → 4F7/2 + 4S3/2 indicate a maximum covalency of Ndsbnd O bond for glass with potassium ions. From the fluorescence spectra, peak wavelength (λp), effective line widths (Δλeff) and stimulated emission cross-section (σp) have been obtained for the three transitions 4F3/2 → 4I9/2,4F3/2 → 4I11/2 and4F3/2 → 4I13/2 of Nd3+ ion. The relatively high values of σp obtained for Nd3+ in present glass system suggest that these materials can be considered as suitable candidates for laser applications. The glass with potassium ions shows the highest value of the stimulated emission cross-section.

  3. Tb{sup 3+} doped Zinc Alumino Bismuth Borate glasses for green emitting luminescent devices

    Energy Technology Data Exchange (ETDEWEB)

    Swapna, K.; Mahamuda, Sk. [Department of Physics, K L University, Green Fields, Vaddeswaram, Guntur (Dt), Andhra Pradesh 522502 (India); Rao, A. Srinivasa, E-mail: drsrallam@gmail.com [Department of Physics, K L University, Green Fields, Vaddeswaram, Guntur (Dt), Andhra Pradesh 522502 (India); Department of Applied Physics, Delhi Technological University, Bawana Road, New Delhi 110042 (India); Jayasimhadri, M. [Department of Applied Physics, Delhi Technological University, Bawana Road, New Delhi 110042 (India); Shakya, Suman; Prakash, G. Vijaya [Nanophotonics Laboratory, Department of Physics, Indian Institute of Technology-Delhi, Hauz Khas, New Delhi 110016 (India)

    2014-12-15

    Zinc Alumino Bismuth Borate (ZnAlBiB) glasses doped with terbium (Tb{sup 3+}) ions with a chemical composition 20ZnO–10Al{sub 2}O{sub 3}–(10−x)Bi{sub 2}O{sub 3}–60B{sub 2}O{sub 3}−xTb{sub 2}O{sub 3} (x=0.1, 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 mol%) were prepared by a conventional melt quenching method and studied their optical absorption, photoluminescence and decay spectral properties. The Judd–Ofelt (J–O) parameters evaluated from the experimental oscillator strengths were used to measure the radiative properties for the prominent luminescent transitions of Tb{sup 3+} ions such as {sup 5}D{sub 4}→{sup 7}F{sub 6}, {sup 7}F{sub 5}, {sup 7}F{sub 4} and {sup 7}F{sub 3.} The effect of Tb{sup 3+} ion concentration on the luminescence process observed in the visible region was discussed in detail. The emission spectra recorded for all the ZnAlBiB glasses doped with Tb{sup 3+} ions, show an intense peak in green region at 542 nm. The stimulated emission cross-section, branching ratios and quantum efficiency values evaluated for green emission ({sup 5}D{sub 4}→{sup 7}F{sub 5}) suggests the utility of these glasses for green luminescence applications. It was found that, within the concentration range investigated, 2.5 mol% of Tb{sup 3+} doped ZnAlBiB glass is most suitable for green luminescence applications at 542 nm in principle. - Highlights: • ZnAlBiB glasses doped with Tb{sup 3+} ions were prepared by a conventional melt quenching technique. • Judd–Ofelt and radiative properties are measured from the emission spectra. • Quantum efficiency of the ZnAlBiB glasses is measured by using radiative and measured lifetimes. • CIE Chromaticity co-ordinates are evaluated from emission spectra.

  4. Synthesis, thermoluminescence and dosimetric properties of La-doped zinc borates

    Energy Technology Data Exchange (ETDEWEB)

    Kucuk, Nil, E-mail: nilkoc@uludag.edu.tr [Physics Department, Faculty of Arts and Sciences, Uludag University, Gorukle Campus, 16059 Bursa (Turkey); Kucuk, Ilker; Cakir, Merve [Physics Department, Faculty of Arts and Sciences, Uludag University, Gorukle Campus, 16059 Bursa (Turkey); Kaya Keles, Sule [Institute of Nuclear Science, Ankara University, Tandogan Campus, 06550 Ankara (Turkey)

    2013-07-15

    Dependence on the dose of beta radiation of undoped and La-doped ZnB{sub 2}O{sub 4} powder samples at 1%, 2%, 3%, 4%, 5% and 10% (by weight) was investigated by thermoluminescence technique. Powder samples were synthesized by the nitric acid method using the starting oxides [zinc oxide (ZnO), boric acid (H{sub 3}BO{sub 3}) and doped element oxide (La{sub 2}O{sub 3})]. The samples were characterized by X-ray diffraction (XRD). The thermoluminescence (TL) properties of the powder samples were measured with Risø TL/OSL DA-20 reader. TL glow curves were obtained with heating at a constant heating rate of 5 °C/s up to 450 °C. The dose response curves of the powder samples exposed to {sup 90}Sr beta radiation (40 mCi) were obtained in the dose range from 143 mGy to 60 Gy. Dose responses and minimum detectable dose (MDD) values for increasing radiation doses of the powder samples were determined. The dose responses of all the samples have shown a quite linear response to beta radiation. MDD value of 10% La-doped ZnB{sub 2}O{sub 4} powder sample which shows a high temperature peak at 207 °C was determined as 4 mGy. MDD values for 1%, 2%, 3%, 4% and 5% La-doped ZnB{sub 2}O{sub 4} powder samples were also determined as 10 mGy, 50 mGy, 10 mGy, 10 mGy and 30 mGy, respectively. Luminescence intensities of the powder samples were shown to be likely to be used for low radiation doses. Highlights: ► Powder samples of undoped and La-doped zinc borate were prepared by the nitric acid method. ► TL properties and dependence on the dose of beta radiation of the samples have been investigated. ► The dose responses of the powder samples showed good linearity. ► The results showed that ZnB{sub 2}O{sub 4}:La sample can be a promising TLD material for dosimetric applications.

  5. Synthesis, thermoluminescence and dosimetric properties of La-doped zinc borates

    International Nuclear Information System (INIS)

    Dependence on the dose of beta radiation of undoped and La-doped ZnB2O4 powder samples at 1%, 2%, 3%, 4%, 5% and 10% (by weight) was investigated by thermoluminescence technique. Powder samples were synthesized by the nitric acid method using the starting oxides [zinc oxide (ZnO), boric acid (H3BO3) and doped element oxide (La2O3)]. The samples were characterized by X-ray diffraction (XRD). The thermoluminescence (TL) properties of the powder samples were measured with Risø TL/OSL DA-20 reader. TL glow curves were obtained with heating at a constant heating rate of 5 °C/s up to 450 °C. The dose response curves of the powder samples exposed to 90Sr beta radiation (40 mCi) were obtained in the dose range from 143 mGy to 60 Gy. Dose responses and minimum detectable dose (MDD) values for increasing radiation doses of the powder samples were determined. The dose responses of all the samples have shown a quite linear response to beta radiation. MDD value of 10% La-doped ZnB2O4 powder sample which shows a high temperature peak at 207 °C was determined as 4 mGy. MDD values for 1%, 2%, 3%, 4% and 5% La-doped ZnB2O4 powder samples were also determined as 10 mGy, 50 mGy, 10 mGy, 10 mGy and 30 mGy, respectively. Luminescence intensities of the powder samples were shown to be likely to be used for low radiation doses. Highlights: ► Powder samples of undoped and La-doped zinc borate were prepared by the nitric acid method. ► TL properties and dependence on the dose of beta radiation of the samples have been investigated. ► The dose responses of the powder samples showed good linearity. ► The results showed that ZnB2O4:La sample can be a promising TLD material for dosimetric applications

  6. Structural, absorption and fluorescence spectral analysis of Pr3+ ions doped zinc bismuth borate glasses

    International Nuclear Information System (INIS)

    Highlights: → 20ZnO.xBi2O3.(79.5-x)B2O3.0.5Pr6O11 (15 ≤ x ≤ 35) glasses were prepared by melt quench technique. → The Judd-Ofelt parameters Ωλ (λ = 2, 4, 6) and other radiative properties like radiative transition probability, radiative life time, branching ratio and stimulated emission cross-section of the prepared glasses have been calculated. → The branching ratio for 3P0 → 3F2 transition of Pr3+ doped glasses is 42% and the predicted spontaneous radiative transition probability rates are fairly high. - Abstract: Glasses having composition 20ZnO.xBi2O3.(79.5 - x)B2O3.0.5Pr6O11 were prepared by melt quench technique. The amorphous nature of the prepared glass samples was confirmed by X-ray diffraction. The spectroscopic properties of these glasses were investigated by recording optical absorption and fluorescence spectra. The structural investigations of the glasses were carried out by recording the IR spectra. The optical properties of Pr3+ ions doped zinc borate glasses with varying concentration of bismuth oxide have been studied. The Judd-Ofelt intensity parameters Ωλ (λ = 2, 4, 6) and other radiative properties like radiative transition probability, radiative life time, branching ratio and stimulated emission cross-section of the prepared glasses have been calculated. The variation of Ω2 with Bi2O3 content has been attributed to changes in the asymmetry of the ligand field at the rare earth ion site and to the changes in their rare earth oxygen (RE-O) covalency. The branching ratio for 3P0 → 3F2 transition is 42% and the predicted spontaneous radiative transition probability rates are fairly high (14,347-14,607 s-1). This is beneficial for lasing emission. The stimulated emission cross-section for all the emission bands has been calculated.

  7. Effect of halides addition on the ligand field of chromium in alkali borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Hassan, M.A., E-mail: moukhtar_hassan@yahoo.com

    2013-10-15

    Highlights: •The 10 KM–64.7 B{sub 2}O{sub 3}–25 Na{sub 2}O–0.3 Cr{sub 2}O{sub 3} (M = Cl, Br and I) glassy system was prepared by a quenching method. •Optical basicity, ligand field theory optical band gap energy, refractive index, ESR and IR were studied. •The electronegativity plays an important role in deforming the crystal field around the transition metal ions. •The crystal-field sites of KCl or KBr sample are very strong compared to the very weak one in the KI sample. -- Abstract: Borate oxide glass system of composition 10 KM–64.7 B{sub 2}O{sub 3}–25 Na{sub 2}O–0.3 Cr{sub 2}O{sub 3} (M = Cl, Br and I) was prepared by conventional melt quenching technique. The amorphous nature of the investigated glasses was checked by the X-ray diffraction (XRD) technique. The optical basicity of the system has been calculated, and was found to increase by going from KCl to KBr and to KI. Optical absorption spectra were recorded in the UV–visible range. Through a careful analysis of the data, the ligand field parameters (crystal field strength Dq, Racah parameters B and nephelauxetic functions h) and the optical parameters (optical band gap, Urbach tail band width, and refractive index) have been estimated. The obtained results reveal a strong correlation between that ligand field parameters and the type of halogen atom; the crystal-field strength of KCl or KBr samples are very pronounced but it is rather weak in the KI sample. Electron spin resonance (ESR) has been used to probe the valency of the Chromium ions. The resulting ESR parameters revealed that chromium ions are predominantly in the trivalent state with traces of hexavalent state. Using Infrared spectroscopy (IR) information on the boron structural units has been obtained. The N{sub 4} ratio increases by replacing the KCl by KBr or KI, and it was found that the tetrahedral coordination of Cr{sup +} ions becomes preferential in the host glasses with increasing the optical basicity.

  8. Hydrothermal synthesis and characterization of the first mixed alkali borate-nitrate K3Na[B6O9(OH)3]NO3

    International Nuclear Information System (INIS)

    The first mixed alkali borate-nitrate K3Na[B6O9(OH)3]NO3 was synthesized under hydrothermal conditions from Na2B4O7·10H2O and K2B4O7·4H2O using KNO3 as a nitrate source. The compound crystallizes in the space group Pnnm (no. 58) with the lattice parameters a=1320.8(3), b=910.7(2), and c=1232.5(3) pm (Z=4). Isolated Sechserrings formed by BO4 and BO3 groups are linked through hydrogen bridges to form a three-dimensional network. - Graphical abstract: The first mixed alkali borate-nitrate K3Na[B6O9(OH)3]NO3 was synthesized under hydrothermal conditions from Na2B4O7·10H2O and K2B4O7·4H2O using KNO3 as a nitrate source. - Highlights: • The first mixed alkali borate-nitrate K3Na[B6O9(OH)3]NO3 is reported. • Hydrothermal conditions (240 °C, 3d) were used for the synthesis of K3Na[B6O9(OH)3]NO3. • Borate Sechserrings are interconnected through hydrogen-bonding

  9. Effect of zinc-borate glass addition on the thermal properties of the cordierite/Al2O3 composites containing nano-sized spinel crystal.

    Science.gov (United States)

    Jo, Sinae; Kang, Seunggu

    2013-11-01

    Low-melting zinc-borate glass was added to the cordierite/Al2O3 composite in order to improve the sintering facility of Al2O3 and formation of nano-sized spinel crystal of high thermal conductivity. Increasing the ZnO/B2O3 ratio in the zinc-borate glass increased the ZnAl2O4 spinel and decreased the Al4B2O9 crystal peak intensities in X-ray diffraction pattern. The XRD peak intensities of the ZnAl2O4 spinel and Al4B2O9 crystals in the specimen containing 10 wt% zinc-borate glass (10G series) are higher than that of the specimen containing 5 wt% zinc-borate glass (5G series). The microstructures of most 10G series specimens had the flower-shaped crystal which was composed of 50 nm wide and 250 nm long needle-like crystals and identified as ZnAl2O4 spinel phase. The thermal conductivity of the 10G series specimen was higher than that of the 5G series in any ZnO/B2O3 ratio due to the formation of plenty of nano-sized ZnAl2O4 spinel of high thermal conductivity. Particularly, the thermal conductivity of the cordierite/Al2O3 composite containing 10 wt% zinc-borate glass of ZnO/B2O3 weight ratio = 1.5 was 3.8 W/Km which is much higher than that of the published value (3.0 W/Km). PMID:24245313

  10. Structure and optical properties of a noncentrosymmetric borate RbSr{sub 4}(BO{sub 3}){sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Xia, M.J. [Beijing Center for Crystal Research and Development, Key Laboratory of Functional Crystals and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Li, R.K., E-mail: rkli@mail.ipc.ac.cn [Beijing Center for Crystal Research and Development, Key Laboratory of Functional Crystals and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China)

    2013-01-15

    A new noncentrosymmetric borate, RbSr{sub 4}(BO{sub 3}){sub 3} (abbreviated as RSBO), has been grown from Rb{sub 2}O--B{sub 2}O{sub 3}--RbF flux and its crystal structure was determined by single crystal x-ray diffraction. It crystallizes in space group Ama2 with cell parameters of a=11.128(10) A, b=12.155(15) A, c=6.952(7) A, Z=4. The basic structural units are isolated planar BO{sub 3} groups. Second harmonic generation (SHG) test of the title compound by the Kurtz-Perry method shows that RSBO can be phase matchable with an effective SHG coefficient about two-thirds as large as that of KH{sub 2}PO{sub 4} (KDP). Finally, based on the anionic group approximation, the optical properties of the title compound are compared with those of the structure-related apatite-like compounds with the formula 'A{sub 5}(TO{sub n}){sub 3}X'. - Graphical abstract: RbSr{sub 4}(BO{sub 3}){sub 3} and some other borate NLO compounds, namely Ca{sub 5}(BO{sub 3}){sub 3}F RCa{sub 4}(BO{sub 3}){sub 3}O (R=Y or Gd) and Na{sub 3}La{sub 2}(BO{sub 3}){sub 3} can be viewed as the derivatives of apatite. They have similar formula composed of five cations and three anion groups (we call them 5/3 structures). The detailed SHG coefficients and optical properties of the apatite-like NLO crystals were compared and summarized. Highlights: Black-Right-Pointing-Pointer A new noncentrosymmetric borate RbSr{sub 4}(BO{sub 3}){sub 3} was grown from flux. Black-Right-Pointing-Pointer The RbSr{sub 4}(BO{sub 3}){sub 3} can be viewed as a derivative of the apatite-like structure. Black-Right-Pointing-Pointer The structure and its relationship to the optical properties of RbSr{sub 4}(BO{sub 3}){sub 3} are compared with other NLO crystals with apatite-like structures. Black-Right-Pointing-Pointer The basic structural units are the planar BO{sub 3} groups in the structure. Black-Right-Pointing-Pointer Second harmonic generation (SHG) test shows that RbSr{sub 4}(BO{sub 3}){sub 3} can be phase matchable

  11. Structural and optical characteristics of Eu3+ ions in sodium-lead-zinc-lithium-borate glass system

    Science.gov (United States)

    Rajagukguk, J.; Kaewkhao, J.; Djamal, M.; Hidayat, R.; Suprijadi; Ruangtaweep, Y.

    2016-10-01

    Structural and optical properties of Eu3+-doped sodium-lead-zinc-lithium-borate glasses (65-x)B2O3sbnd 15Na2Osbnd 10PbOsbnd 5ZnOsbnd 5Li2Osbnd xEu2O3 (where x = 0, 0.05, 0.1, 0.5, 1.0, 2.0 and 4.0) have been measured and analyzed by varying the Eu3+ ion concentrations. The physical parameters such as polaron radius, field strength and inter nuclear distance have been determined from measurements of densities and refractive indices. The structural properties of the prepared borate glasses were analyzed based on X-ray diffraction (XRD) and FTIR instruments. The diffraction spectra show no characteristic peaks in these glasses, which indicates the amorphous nature of the glasses. The infrared spectrum of the Eu3+-doped sodium-lead-zinc-lithium-borate glass systems show three disparate regions for active absorption band around 830-860 cm-1, 1020-1040 cm-1 and 1170-1180 cm-1. The electronic transitions in the UV-vis and NIR regions are assigned to the 7F0 → 5D4, 7F0 → 5G2, 7F0 → 5L6, 7F0 → 5D3, 7F0 → 5D2, 7F0 → 5D1, 7F0 → 5D07F1 → 5D07F0 → 7F6 and 7F1 → 7F6 levels centered at 362 nm, 380 nm, 395 nm, 414 nm, 465 nm, 533 nm, 583 nm, 590 nm 2092 nm and 2202 nm respectively. Five transition bands of luminescence spectra have been observed by using an excited wavelength of 395 nm. The luminescence intensity ratio (R) of 5D0 → 7F2 (electric dipole) transition to 5D0 → 7F1 (magnetic dipole) transition has been determined to obtain the strength of the covalent/ionic bond between the Eu3+ ions and the surrounding ligands. Radiative life time and emission color of the glasses were estimated and compared with other literature data by varying Eu3+ concentrations. The experimental lifetime of the 5D0 level was found to increase with increasing Eu3+ ion content, suggesting higher non-radiative energy transfer among Eu3+ ions in the glasses.

  12. Pb2 BO3 Cl: A Tailor-Made Polar Lead Borate Chloride with Very Strong Second Harmonic Generation.

    Science.gov (United States)

    Zou, Guohong; Lin, Chensheng; Jo, Hongil; Nam, Gnu; You, Tae-Soo; Ok, Kang Min

    2016-09-19

    A meticulously designed, polar, non-centrosymmetric lead borate chloride, Pb2 BO3 Cl, was synthesized using KBe2 BO3 F2 (KBBF) as a model. Single-crystal X-ray diffraction revealed that the structure of Pb2 BO3 Cl consists of cationic [Pb2 (BO3 )](+) honeycomb layers and Cl(-) anions. Powder second harmonic generation (SHG) measurements on graded polycrystalline Pb2 BO3 Cl indicated that the title compound is phase-matchable (type I) and exhibits a remarkably strong SHG response, which is approximately nine times stronger than that of potassium dihydrogen phosphate, and the largest efficiency observed in materials with structures similar to KBBF. Further characterization suggested that the compound melts congruently at high temperature and has a wide transparency window from the near-UV to the mid-IR region. PMID:27555114

  13. Synthesis and photoluminescence properties of Pb2+ doped inorganic borate phosphor NaSr4(BO3)3

    Science.gov (United States)

    Chauhan, A. O.; Koparkar, K. A.; Bajaj, N. S.; Omanwar, S. K.

    2016-05-01

    A series of Inorganic borate phosphors NaSr4(BO3)3 doped with Pb2+ was successfully synthesized by modified solid state diffusion method. The crystal structure and the phase purity of sample were characterized by powder X-ray diffraction (XRD). The photoluminescence properties of synthesized materials were investigated using spectrofluorometer at room temperature. The phosphor show strong broad band emission spectra in UVA region maximum at 370 nm under the excitation of 289 nm. The dependence of the emission intensity on the Pb2+ concentration for the NaSr4(BO3)3 were studied in details. The concentration quenching of Pb2+ doped NaSr4(BO3)3 was observed at 0.02 mol. The Stokes shifts of NaSr4(BO3)3: Pb2+ phosphor was calculated to be 7574 cm-1.

  14. One-photon band gap engineering of borate glass doped with ZnO for photonics applications

    International Nuclear Information System (INIS)

    Lithium tungsten borate glass of the composition (0.56-x)B2O3-0.4Li2O-xZnO-0.04WO3 (0 ≤x≤ 0.1 mol. %) is prepared for photonics applications. The glass is doped with ZnO to tune the glass absorption characteristics in a wide spectrum range (200-2500 nm). Chemical bond approach, including chemical structure, electronegativity, bond ionicity, nearest-neighbor coordination, and other chemical bonding aspect, is used to analyze and to explain the obtained glass properties such as: transmittance, absorption, electronic structure parameters (bandgap, Fermi level, and Urbach exciton-phonon coupling), Wannier free excitons excitation (applying Elliott's model), and two-photon absorption coefficient as a result of replacement of B2O3 by ZnO.

  15. Effect of Co(2+) and Ni(2+)-doped zinc borate nano crystalline powders by co-precipitation method.

    Science.gov (United States)

    Shim, Jaesool; Venkata Reddy, Ch; Sarma, G V S S; Narayana Murthy, P; Ravikumar, R V S S N

    2015-05-01

    A simple co-precipitation method has been used for the synthesis of Co(2+) and Ni(2+)-doped zinc borate nanopowders. X-ray diffraction (XRD), Fourier transform infrared (FT-IR), UV/Vis absorption, Scanning electron microscope (SEM) with EDS and photoluminescence (PL) spectroscopies techniques has been employed for their characterization. Powder X-ray diffraction data reveals that the crystal structure belongs to monoclinic for both as-prepared samples. SEM images showed surface morphology of the prepared samples. Optical absorption spectra showed the characteristic bands of doped ions in octahedral site symmetry. From the optical absorption data crystal field and inter-electronic repulsion parameters are evaluated. The FT-IR spectra showed the characteristic vibrational bands related to ZnO, BO3 and BO4 molecules. Photoluminescence spectra exhibited the emission bands in ultraviolet and blue regions. PMID:25706597

  16. Effect of Co2+ and Ni2+-doped zinc borate nano crystalline powders by co-precipitation method

    Science.gov (United States)

    Shim, Jaesool; Venkata Reddy, Ch.; Sarma, G. V. S. S.; Narayana Murthy, P.; Ravikumar, R. V. S. S. N.

    2015-05-01

    A simple co-precipitation method has been used for the synthesis of Co2+ and Ni2+-doped zinc borate nanopowders. X-ray diffraction (XRD), Fourier transform infrared (FT-IR), UV/Vis absorption, Scanning electron microscope (SEM) with EDS and photoluminescence (PL) spectroscopies techniques has been employed for their characterization. Powder X-ray diffraction data reveals that the crystal structure belongs to monoclinic for both as-prepared samples. SEM images showed surface morphology of the prepared samples. Optical absorption spectra showed the characteristic bands of doped ions in octahedral site symmetry. From the optical absorption data crystal field and inter-electronic repulsion parameters are evaluated. The FT-IR spectra showed the characteristic vibrational bands related to ZnO, BO3 and BO4 molecules. Photoluminescence spectra exhibited the emission bands in ultraviolet and blue regions.

  17. Photoannealing of radiation induced colour centers in sodium borate glasses with group 2B-5B metal oxides

    International Nuclear Information System (INIS)

    Using the methods of microsecond pulse radiolysis (PR), optical and ESR-spectroscopy, the processes of photoannealing of radiation induced colour centres (RICC) on the basis of metal ions in unstable oxidation states (MIUOS) in 2S1/2 electron state in sodium-borate glasses (SBG) in a wide time range have been investigated. Absorption spectra of the RICC are determined. It is shown that the effectiveness of RICC destruction depends both on the intensity and spectral composition of the affecting light. It is ascertained that the energy of optical transitions in the maxima of absorption bands (AB) and effectiveness of MIUOS destruction with an increase in the oxidation degree of ions Z decrease regularly in isoelectron series

  18. Photoannealing of radiation color centers in sodium borate glasses with oxides of metals from groups IIB-VB

    International Nuclear Information System (INIS)

    The processes resulting in the photoannealing of radiation color centers based on ions of metals in unstable oxidation states in the 2S1/2 electronic state in sodium borate glasses have been investigated by microsecond pulse radiolysis, optical spectroscopy, and ESR spectroscopy over a broad range of times. The absorption spectra of these radiation color centers have been determined. It has been shown that the efficiency of the destruction of the radiation color centers depends both on the intensity and on the spectroscopic composition of the light used. It has been established that the energy of the optical transitions at the maxima of the absorption bands and the efficiency of the destruction of the metal ions in unstable oxidation states undergo regular decreases along isoelectronic series as the oxidation number of the ions Z is increased

  19. Luminescence properties of Dy3+ ions in a variety of borate and fluoroborate glasses containing lithium, zinc, and lead

    International Nuclear Information System (INIS)

    The fluorescence properties of Dy3+ ions, with two concentrations (1.0 and 0.1 mol%), have been investigated in a variety of borate and fluoroborate glasses modified with lithium, zinc, and/or lead. The fluorescence spectra and lifetimes of 4F9/2 level of Dy3+ ions in these glasses have been measured using the 457.9 nm line of argon ion laser as an excitation source. Decreasing trend in lifetimes has been observed when the glass compositions contain modifiers in the order of LiF→Li2O→ZnO→PbO. Decay curves for these glasses are found to be single exponential and non-exponential for 0.1 and 1.0 mol% concentrations, respectively. The non-exponential decay curves have been well fitted with the Inokuti-Hirayama (I-H) model for dipole-dipole interaction

  20. Broadly tunable, beta-barium-borate-based, pulsed optical parametric oscillators and their potential applications in medicine

    Science.gov (United States)

    Sobey, Mark S.; Clark, Jim; Johnson, Bertram C.

    1995-05-01

    With the recent availability of Beta Barium Borate (BBO) crystals in useful sizes at acceptable market prices, the promise of Optical Parametric Oscillators (OPOs) becoming practical tunable systems is finally being realized. Wavelength coverage from such systems extends from 420 nm to over 2400 nm when pumped in the UV. For medical applications their usage will be limited in the near term to low repetition rates (tattoo removal or treating vascular lesions. For such high energy devices peak powers necessitate the use of articulating arms for beam delivery. For high repetition rate systems, energy outputs will be in the range of 100 to 500 (mu) J at kHz frequencies (up to 1 W average power). Peak powers are low enough that fiber optic delivery is possible. These systems may find selective absorption applications in ophthalmology.

  1. One-photon band gap engineering of borate glass doped with ZnO for photonics applications

    Energy Technology Data Exchange (ETDEWEB)

    Abdel-Baki, Manal [Glass Department, National Research Centre, Dokki 12311 Giza (Egypt); Abdel-Wahab, Fathy A.; El-Diasty, Fouad [Physics Department, Faculty of Science, Ain Shams University, Abbasia, 11566 Cairo (Egypt)

    2012-04-01

    Lithium tungsten borate glass of the composition (0.56-x)B{sub 2}O{sub 3}-0.4Li{sub 2}O-xZnO-0.04WO{sub 3} (0 {<=}x{<=} 0.1 mol. %) is prepared for photonics applications. The glass is doped with ZnO to tune the glass absorption characteristics in a wide spectrum range (200-2500 nm). Chemical bond approach, including chemical structure, electronegativity, bond ionicity, nearest-neighbor coordination, and other chemical bonding aspect, is used to analyze and to explain the obtained glass properties such as: transmittance, absorption, electronic structure parameters (bandgap, Fermi level, and Urbach exciton-phonon coupling), Wannier free excitons excitation (applying Elliott's model), and two-photon absorption coefficient as a result of replacement of B{sub 2}O{sub 3} by ZnO.

  2. Beam patterns in an optical parametric oscillator set-up employing walk-off compensating beta barium borate crystals

    Science.gov (United States)

    Kaucikas, M.; Warren, M.; Michailovas, A.; Antanavicius, R.; van Thor, J. J.

    2013-02-01

    This paper describes the investigation of an optical parametric oscillator (OPO) set-up based on two beta barium borate (BBO) crystals, where the interplay between the crystal orientations, cut angles and air dispersion substantially influenced the OPO performance, and especially the angular spectrum of the output beam. Theory suggests that if two BBO crystals are used in this type of design, they should be of different cuts. This paper aims to provide an experimental manifestation of this fact. Furthermore, it has been shown that air dispersion produces similar effects and should be taken into account. An x-ray crystallographic indexing of the crystals was performed as an independent test of the above conclusions.

  3. STUDIES OF A.C. CONDUCTIVITY OF POLY(VINYL BORATE) AND ITS CALCIUM DERIVATIVE IN SOLID STATE

    Institute of Scientific and Technical Information of China (English)

    Prafulla Chetri; Neelotpal Sen Sarma; Narendra Nath Dass

    2008-01-01

    An attempt has been made in the present work to prepare poly(vinyl borate), PVBO and its calcium derivative by homogeneous esterification of PVA with boric acid in non-aqueous medium in the presence of a catalyst ethyl nitrate dimethyl sulfoxide. The compounds were characterized by IR and 1H-NMR spectra. Conductivities were determined from 30℃ to 90℃ in solid state within a frequency range of 42 Hz to 100 kHz. The compounds so formed showed ionic conductivity and their conductivities were dependent on frequencies used. It is found that the addition of Ca2+ ion increases the ionic conductivity of PVBO appreciably. The conductivity of PVBO-Ca increases rapidly after 50℃. The total ionic transport number and activation energy of the copolymers were also determined.

  4. 硼酸锌的阻燃机理及其纳米化制备研究进展%Inflaming Retarding Mechanism and Preparation Methods of Zinc Borate Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    袁光辉

    2011-01-01

    硼酸锌作为一种环保无机阻燃剂,具有无毒、无污染、阻燃及抑烟的优良性能。综述了硼酸锌阻燃剂的主要性质、阻燃机理和纳米硼酸锌的制备方法,指出硼酸锌的纳米化制备是目前合成工艺的研究重点。%Zinc borate is an inorganic flare retardant with environmental protection function. Its characteristics are good-stabillty, low-toxicity and no-smoke. This article summarizes the main property, the inflaming retarding mechanism of zinc borate and the preparing processes of zinc borate nanoparticles. The preparation of zinc borate nanoparticles is the emphasis of current research.

  5. Antiquenching effect of modifying cations on samarium clustering: Physical, structural and luminescent behavior of heavy metal borate glass systems

    Science.gov (United States)

    Kaur, Simranpreet; Kaur, Parvinder; Pal Singh, Gurinder; Kumar, Sunil; Singh, D. P.

    2015-09-01

    In this paper an attempt has been made to correlate the structural modifications and luminescence efficiencies by changing the environment of the glass network by modifying oxides. Sm3+ doped lead borate (SPB) and lead cadmium alumino borate (SCPB) glasses have been fabricated by melt quench technique at high temperature. The glass samples are characterized by XRD, FTIR, optical absorptions, fluorescence and density measurements. The effect of Sm3+ ion and glass host interaction on the emission spectra has been discussed in the view of the ionicity and covalency of hosts. The ratio of the intensities of electric to magnetic dipole emissions are calculated by varying both the concentration of the Sm3+ ion and the composition of the glass matrix. The XRD profile of all the glasses confirms their amorphous nature and FTIR spectrum shows the presence of BO3 and BO4 groups. These glasses have shown strong absorption bands in the visible (VIS and NIR) region and emit strong orange red wavelengths when excited by ultraviolet light. The concentration quenching has been noticed and ascribed to energy transfer through cross-relaxation between Sm3+ ions. Shifting of UV absorption edge towards longer wavelength with addition of Sm2O3 concentration has been observed. Incorporation of Al2O3 and CdO in 2nd glass system is responsible for strong effect on luminescence of the present glass system. Based on these results, an attempt has been made to throw some light on the relationship between the structural modifications and luminescence efficiencies in two different glass hosts as a laser active medium in the visible region. Moreover the optical basicity values were theoretically determined along with covalent behavior of two glass systems.

  6. Optical absorption and luminescence characteristics of Dy3+ doped Zinc Alumino Bismuth Borate glasses for lasing materials and white LEDs

    International Nuclear Information System (INIS)

    Good optical quality Dy3+ doped Zinc Alumino Bismuth Borate (ZnAlBiB) glasses were prepared by the conventional melt quenching technique and characterized by optical absorption and luminescence studies. The glassy nature of these materials has been confirmed through XRD measurements. From the absorption spectra, the three phenomenological JO parameters Ωλ (λ=2,4 and 6) have been determined from the absorption spectral intensities by using the JO theory. Luminescence spectra were measured for different concentrations of Dy3+ ions doped glasses by exciting the glasses at 387 nm. The intensity of Dy3+ emission spectra increases from 0.5 mol% to 1 mol % and beyond 1 mol % the concentration quenching is observed. The suitable concentration of Dy3+ ions for ZnAlBiB glassy material to act as good lasing material has been discussed by measuring the branching ratios and emission cross-sections for two strong emission transitions such as 4F9/2→6H15/2 and 4F9/2→6H13/2 observed in visible region. By exciting these glassy materials at various excitation wavelengths in n-UV region, the CIE chromaticity coordinates were evaluated for the two sharp emissions observed in blue (4F9/2→6H15/2) and yellow (4F9/2→6H13/2) regions to understand the suitability of these materials for white light generation. -- Highlights: ► Successfully synthesized the transparent Zinc Alumino Bismuth Borate glasses. ► Measured the absorption and luminescence properties. ► Discussed the spectroscopic properties by using Judd–Ofelt analysis for ZnAlBiB glasses. ► Finally, suitability of these glasses for lasers and white LEDs has been discussed

  7. Structural,Electronic Properties and Chemical Bonding of Borate Li4CaB2O6 under High Pressure:an Ab Initio Investigation

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hong; TANG Jin; CHENG Xin-Lu

    2008-01-01

    We calculate structural,electromc properties and chemical bonding of borate Li4CaB2O6 under high pressure by means of the local density-functional pseudopotential approach.The equilibrium lattice constants,density of states,Mulliken population,bond lengths,bond angles as well as the pressure dependence of the band gap are presented.Analysis of the simulated high pressure band structure suggests that borate Li4CaB2O6 can be used as the semi-conductor optical material.Based on the Mulliken population analysis,it is found that the electron transfer of the Li atom is very different from that of other atoms in the studied range of high pressures.The charge populations of the Li atom decrease with the pressure up to 60GPa,then increase with the pressure.

  8. Thermoluminescence characteristics of zinc lithium borate glass activated with Cu+ (ZnO-Li2O-B2O3:Cu+) for radiation dosimetry

    International Nuclear Information System (INIS)

    Copper doped zinc lithium borate glass was prepared by solid state melt quenching method and characterized using X-ray diffractometry. The effect of varying concentration of dopant CuO on thermoluminescence (TL) properties of zinc lithium borate is reported in this paper. The best annealing temperature and time were found to be 300 deg C and 30 min respectively. While the optimal heating rate was 3 deg C. Glow curves with single peaks for all concentrations were obtained. The TL intensity increases with the increase of dopant concentration and radiation dose from 0.5 to 4 Gy. Time-base thermal fading was stable. Attractive reusability and kinetic parameters of the phosphor were also achieved. These outstanding features show that our dosimeter has the potential ability to use for radiation processing dosimetry. (author)

  9. Corrosion studies of thermally sensitised AGR fuel element brace in pH7 and pH9.2 borate solutions

    International Nuclear Information System (INIS)

    Brace and cladding of AGR fuel elements sensitised in reactor are susceptible to intergranular and crevice corrosion, which may initiate in the pH7 borate pond storage environment of CEGB/SSEB stations. This report considers the benefit in corrosion control that is provided by raising the pond solution pH to 9.2, whilst maintaining the boron level at 1250 gm-3. The greater corrosion protection provided by pH9.2 solution compared to the pH7 borate solution is demonstrated by a series of tests with non-active laboratory sensitised brace samples exposed to solutions dosed with chloride or sulphate in order to promote localised corrosion. The corrosion tests undertaken consisted of 5000 hour immersions at 320C and shorter term electrochemically monitored experiments (rest potential, impedance, anodic current) generally conducted at 220C. The pH9.2 solution effectively inhibited the initiation of crevice and intergranular corrosion in the presence of low levels of chloride and sulphate, whereas the pH7 solution did not always do so. However, the pH9.2 solution, dosed with 40 gm-3 chloride, failed to suppress fully crevice corrosion initiated in unborated 40 gm-3 chloride solution at 220C. Fluoride is not deleterious at low levels ∼ 10 gm-3 in the borate solutions. The significant improvement in corrosion control demonstrated for the change from pH7 to pH9.2 borate solution on laboratory sensitised brace samples should ideally be confirmed using complete irradiated AGR fuel elements. (U.K.)

  10. The Properties, Preparation and Utilization of Aluminium Borate Whisker%硼酸铝晶须的性质、制备和开发前景

    Institute of Scientific and Technical Information of China (English)

    李武

    2000-01-01

    无机材料在国民经济和国防建设中均占有重要地位。简单介绍了一种重要的新型无机功能材料——硼酸铝晶须的性能、制备和应用前景。%The properties, preparation methods and utilization of Aluminium borate whisker was briefly introduced.

  11. Crystal growth, structure, infrared spectroscopy, and luminescent properties of rare-earth gallium borates RGa3(BO3)4, R = Nd, Sm-Er, Y

    Science.gov (United States)

    Borovikova, Elena Yu.; Boldyrev, Kirill N.; Aksenov, Sergey M.; Dobretsova, Elena A.; Kurazhkovskaya, Victoria S.; Leonyuk, Nikolay I.; Savon, Alexander E.; Deyneko, Dina V.; Ksenofontov, Dmitry A.

    2015-11-01

    Crystals of the rare-earth gallium borates RGa3(BO3)4, where R = Nd, Sm-Er, or Y, were grown by the flux method. The crystal structures of RGa3(BO3)4 (R = Eu, Ho) were studied on the basis of single-crystal X-ray diffraction measurements. The hexagonal unit-cell parameters are a = 9.4657(1) Å, c = 7.4667(1) Å and a = 9.4394(2) Å, c = 7.4322(1) Å for EuGa3(BO3)4 and HoGa3(BO3)4, respectively, space group R32. Structure model was determined by "charge flipping" method and refined to R = 1.93% [EuGa3(BO3)4] and R = 1.89% [HoGa3(BO3)4] in anisotropic approximation. All grown gallium borates were investigated by infrared (IR) spectroscopy technique in a middle and far IR region. IR spectra of rare-earth gallium borates correspond to a pure rhombohedral (R32) polytype structure. Small inclusions of a monoclinic phase were detected only in Eu and Nd compounds. Luminescence of Eu and Ho gallium borates was studied at room temperature. The measured decay times for the most intensive emission lines of EuGa3(BO3)4 (∼614 nm) and HoGa3(BO3)4 (434 nm) are 940 μs and 140 μs, respectively. The scheme of crystal-field energy levels of Eu3+ in EuGa3(BO3)4 was built on the basis of the temperature-dependent optical transmission measurements combined with the luminescence data. The measured UV absorption edge for RGa3(BO3)4 is at about 300 nm.

  12. Use of a new borate raw material for glaze formulation; Utilizacion de una nueva materia prima boracica para la formulacion de esmaltes

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Tena, M. P.; Moreno, A.; Bou, E.; Cook, S.; Galindo, M.

    2010-07-01

    The Rio Tinto Minerals company has developed a new borate (E-4972), which can be used in glaze formulation (patent WO 2007/148101). This new borate, synthesised by low-temperature calcination, fundamentally contributes five oxides: silicon oxide (SiO{sub 2}), aluminium oxide (Al{sub 2}O{sub 3}), boron oxide (B{sub 2}O{sub 3}), calcium oxide (CaO), and sodium oxide (Na{sub 2}O), its content in B{sub 2}O{sub 3} being between 10 and 11% by weight. It is largely amorphous, and quartz is the major crystalline phase present. The characteristics of this new borate, such as its low solubility and ability readily to form glassy phase, enable it to be used as a raw material in glaze compositions. Its suitability for glaze formulation has been the result of several years research in collaboration with the Instituto de Tecnologia Ceramica. In this paper, the feasibility has been studied of fabricating ceramic glazes by using a new synthetic borate raw material that contributes boron to the glaze composition without this needing to be done in fritted form. It has been possible to obtain fired glazes with similar technical and aesthetics characteristics to those obtained from industrial glaze compositions that contain typical frits in their compositions, thus enabling glazes to be formulated by using the new synthetic boron raw material. The results obtained show that this new raw material (E-4972) is particularly appropriate for use in producing glazes with low gloss at high temperature. (Author) 15 refs.

  13. Les trifluoro(organo)borates de potassium : nouvelles perspectives pour la formation de liaisons carbone-carbone à l'aide de complexes du rhodium

    OpenAIRE

    Pucheault, Mathieu

    2004-01-01

    This manuscript describes the use of potassium trifluoro(organo)borates in rhodiumcatalyzed carbon-carbon bond forming reactions. These easy to purify and very stable reagents turned out to constitute a valuable alternative to other boron reagents commonly used in transition metal catalyzed reactions. Asymmetric rhodium-catalyzed 1,4-additions of trifluoroborates were developed with the use of a chiral diphosphine which allowed a good control of the enantioselectivity. Under neutral condition...

  14. Nonclinical safety evaluation of boric acid and a novel borate-buffered contact lens multi-purpose solution, Biotrue™ multi-purpose solution.

    Science.gov (United States)

    Lehmann, David M; Cavet, Megan E; Richardson, Mary E

    2010-12-01

    Multipurpose solutions (MPS) often contain low concentrations of boric acid as a buffering agent. Limited published literature has suggested that boric acid and borate-buffered MPS may alter the corneal epithelium; an effect attributed to cytotoxicity induced by boric acid. However, this claim has not been substantiated. We investigated the effect of treating cells with relevant concentrations of boric acid using two cytotoxicity assays, and also assessed the impact of boric acid on corneal epithelial barrier function by measuring TEER and immunostaining for tight junction protein ZO-1 in human corneal epithelial cells. Boric acid was also assessed in an in vivo ocular model when administered for 28 days. Additionally, we evaluated Biotrue multi-purpose solution, a novel borate-buffered MPS, alone and with contact lenses for ocular compatibility in vitro and in vivo. Boric acid passed both cytotoxicity assays and did not alter ZO-1 distribution or corneal TEER. Furthermore, boric acid was well-tolerated on-eye following repeated administration in a rabbit model. Finally, Biotrue multi-purpose solution demonstrated good ocular biocompatibility both in vitro and in vivo. This MPS was not cytotoxic and was compatible with the eye when administered alone and when evaluated with contact lenses. We demonstrate that boric acid and a borate-buffered MPS is compatible with the ocular environment. Our findings provide evidence that ocular effects reported for some borate-buffered MPS may be incorrectly attributed to boric acid and are more likely a function of the unique combination of ingredients in the MPS formulation tested.

  15. The thermal stability and pyrolysis mechanism of boron-containing phenolic resins: The effect of phenyl borates on the char formation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shujuan; Wang, Yong; Bian, Cheng; Zhong, Yuhu [Department of Applied Chemistry, School of Science, Xi’an Jiaotong University, Xi’an 710049, People’ s Republic of China (China); Jing, Xinli, E-mail: rgfp-jing@mail.xjtu.edu.cn [Department of Applied Chemistry, School of Science, Xi’an Jiaotong University, Xi’an 710049, People’ s Republic of China (China); MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, Xi’an, 710049, People’ s Republic of China (China)

    2015-03-15

    Graphical abstract: - Highlights: • The thermal stability and pyrolysis mechanism of cured BPR are investigated. • The high char yield of BPR results from the formed phenyl borates during curing. • Boron oxide is formed on the surface of carbonized product during pyrolysis. • The formed boron oxide revealed the cleavage of O–C bonds from phenyl borates. • The graphitization degree and graphite crystallites of PR are improved by introducing boron. - Abstract: Boron-containing phenolic resin (BPR) is a kind of the ablative resins with high-performance. Due to the lack of the exact knowledge concerning the pyrolysis mechanism of BPR, its development and application are greatly impeded. In the present paper, the chemical structure of the cured BPR and its structural evolution at high temperatures are investigated to clarify the reason for the high char yield of BPR. The results indicate that the high char yield of BPR is mainly attributed to the phenyl borates formed during curing, which can block parts of phenolic hydroxyl groups, and effectively inhibit their thermal decomposition reaction. Boron oxide is formed on the surface of carbonization products by the cleavage of O–C bonds from phenyl borates via pyrolysis, which avoids the release of volatile carbon dioxide and reduces the development of micro-structural defects of carbonization products. Introducing boron into PR improves the graphitization degree and graphite crystallites of carbonization products, which promotes the formation of a more ordered glassy carbon during pyrolysis. This study provides a new vision for the understanding of the high char yield of BPR, which makes it possible to develop a new ablative resin through molecular design.

  16. Flame retardancy mechanisms of bisphenol A bis(diphenyl phosphate) in combination with zinc borate in bisphenol A polycarbonate/acrylonitrile-butadiene-styrene blends

    International Nuclear Information System (INIS)

    Bisphenol A polycarbonate/acrylonitrile-butadiene-styrene (PC/ABS) with and without bisphenol A bis(diphenyl phosphate) (BDP) and 5 wt.% zinc borate (Znb) were investigated. The pyrolysis was studied by thermogravimetry (TG), TG-FTIR and NMR, the fire behaviour with a cone calorimeter applying different heat fluxes, LOI and UL 94. Fire residues were examined with NMR. BDP affects the decomposition of PC/ABS and acts as a flame retardant in the gas and condensed phases. The addition of Znb results in an additional hydrolysis of PC. The fire behaviour is similar to PC/ABS, aside from a slightly increased LOI and a reduced peak heat release rate, both caused by borates improving the barrier properties of the char. In PC/ABS + BDP + Znb, the addition of Znb yields a borate network and amorphous phosphates. Znb also reacts with BDP to form alpha-zinc phosphate and borophosphates that suppress the original flame retardancy mechanisms of BDP. The inorganic-organic residue formed provides more effective flame retardancy, in particular at low irradiation in the cone calorimeter, and a clear synergy in LOI, whereas for more developed fires BDP + Znb become less effective than BDP in PC/ABS with respect to the total heat evolved.

  17. Beneficial effect of propane sultone and tris(trimethylsilyl) borate as electrolyte additives on the cycling stability of the lithium rich nickel manganese cobalt (NMC) oxide

    Science.gov (United States)

    Birrozzi, Agnese; Laszczynski, Nina; Hekmatfar, Maral; von Zamory, Jan; Giffin, Guinevere A.; Passerini, Stefano

    2016-09-01

    This study reports the investigation of several compounds as electrolyte additives for Li[Li0.2Mn0.56 Ni0.16 Co0.08]O2 (a.k.a lithium rich NMC) cathode material. Among the compounds investigated via electrochemical and ex-situ analytical techniques, i.e. XRD, XPS and RAMAN spectroscopy, only 1,3-propane sultone and tris(trimethylsilyl) borate show a beneficial effect on the capacity retention and coulombic efficiency of the layered cathode. The results suggest that the improved capacity retention of the cells containing the two above-mentioned additives mainly originates from their participation in the formation of the cathode passive layer, which prevents the dissolution of the metals from the cathode material. Additionally, the borate additive reduces the lithium consumption upon the passive layer formation thus leaving a higher amount of lithium available in the electrolyte. Graphite/Li[Li0.2Mn0.56 Ni0.16 Co0.08]O2 cells containing the borate additive in the electrolyte showed 85% capacity retention after 485 cycles, confirming the feasibility of its employment for practical applications.

  18. Transition metal complexes of oxazolinylboranes and cyclopentadienyl-bis(oxazolinyl)borates: Catalysts for asymmetric olefin hydroamination and acceptorless alcohol decarbonylation

    Energy Technology Data Exchange (ETDEWEB)

    Manna, Kuntal [Ames Lab., Ames, IA (United States)

    2012-12-17

    The research presented and discussed in this dissertation involves the synthesis of transition metal complexes of oxazolinylboranes and cyclopentadienyl-bis(oxazolinyl)borates, and their application in catalytic enantioselective olefin hydroamination and acceptorless alcohol decarbonylation. Neutral oxazolinylboranes are excellent synthetic intermediates for preparing new borate ligands and also developing organometallic complexes. Achiral and optically active bis(oxazolinyl)phenylboranes are synthesized by reaction of 2-lithio-2-oxazolide and 0.50 equiv of dichlorophenylborane. These bis(oxazolinyl)phenylboranes are oligomeric species in solid state resulting from the coordination of an oxazoline to the boron center of another borane monomer. The treatment of chiral bis(oxazolinyl)phenylboranes with sodium cyclopentadienide provide optically active cyclopentadienyl-bis(oxazolinyl)borates H[PhB(C5H5)(OxR)2] [OxR = Ox4S-iPr,Me2, Ox4R-iPr,Me2, Ox4S-tBu]. These optically active proligands react with an equivalent of M(NMe2)4 (M = Ti, Zr, Hf) to afford corresponding cyclopentadienyl-bis(oxazolinyl)borato group 4 complexes {PhB(C5H4)(OxR)2}M(NMe2)2 in high yields. These group 4 compounds catalyze cyclization of aminoalkenes at room temperature or below, providing pyrrolidine, piperidine, and azepane with enantiomeric excesses up to 99%. Our mechanistic investigations suggest a non-insertive mechanism involving concerted C-N/C-H bond formation in the turnover limiting step of the catalytic cycle. Among cyclopentadienyl-bis(oxazolinyl)borato group 4 catalysts, the zirconium complex {PhB(C5H4)(Ox4S-iPr,Me2)2}Zr(NMe2)2 ({S-2}Zr(NMe2)2) displays highest activity and enantioselectivity. Interestingly, S-2

  19. Sm{sup 3+}-doped alkaline earth borate glasses as UV→visible photon conversion layer for solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Shen, L.F. [School of Textile and Material Engineering, Dalian Polytechnic University, Dalian 116034 (China); Department of Electronic Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Chen, B.J.; Pun, E.Y.B. [Department of Electronic Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Lin, H., E-mail: lhai8686@yahoo.com [School of Textile and Material Engineering, Dalian Polytechnic University, Dalian 116034 (China); Department of Electronic Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China)

    2015-04-15

    Intense multi-peak red fluorescence emissions of Sm{sup 3+} are exhibited in alkaline-earth borate (LKZBSB) glasses under UV radiation. The spontaneous emission probabilities A{sub rad} corresponding to the {sup 4}G{sub 5/2}→{sup 6}H{sub J} (J=5/2, 7/2, 9/2 and 11/2) transitions are derived to be 24.74, 129.72, 117.03 and 32.23 s{sup −1}, respectively, and the relevant stimulated emission cross-sections σ{sub em} are 0.77×10{sup −22}, 4.46×10{sup −22}, 5.05×10{sup −22} and 1.38×10{sup −22} cm{sup 2}, confirming the effectiveness of red luminescence in Sm{sup 3+}-doped LKZBSB glasses. Quantitative characterization through the evaluation of absolute spectral parameters reveals that the quantum yield of Sm{sup 3+}-doped LKZBSB glasses is as high as 13.29%. Furthermore, with the introduction of Ce{sup 3+}, the effective excitation wavelength range and the emission intensity of Sm{sup 3+} in LKZBSB glasses are remarkably expanded and improved by a maximum sensitization factor of 9.02 in the UVB region. These results demonstrate that the present glass system has promising potential as an efficient UV→visible photon conversion layer for the enhancement of solar cell efficiency, including appealing applications in outer space. - Highlights: • Intense multi-peak red fluorescence emissions of Sm{sup 3+} are exhibited under UV radiation. • Effectiveness of red luminescence is confirmed by stimulated emission cross-sections. • Quantum yield of Sm{sup 3+}-doped LKZBSB glasses is 13.29% by quantitative characterization. • Effective excitation wavelength range and emission intensity are improved with Ce{sup 3+} doping. • Alkaline-earth borate glass has potential as solar cell UV→Vis photon conversion layer.

  20. The Development Status and Application of Borate Coupling Agent%硼酸酯偶联剂的发展现状及应用前景

    Institute of Scientific and Technical Information of China (English)

    赵园; 周莉; 李玉玲; 徐新宇

    2011-01-01

    硼酸酯偶联剂是一种新型的偶联剂,和传统的偶联剂相比,它具有很多新的特点.硼酸酯偶联剂以硼原子为中心原子,可以应用于含硼无机物填料的表面改性,改善含硼无机填料和聚合物之间的相容性.硼酸酯偶联剂具有硼-氧骨架,可以和硼酸盐晶须间产生良好的物理吸附作用.在改性硼酸盐晶须方面,硼酸酯偶联剂具有较好的改性效果.近年来,国内各院校对于硼酸酯偶联剂的合成与应用已有很大进展,主要用于复合材料的制备上.主要概述了硼酸酯偶联剂现阶段的发展现状及在复合材料中的应用,并介绍了硼酸酯偶联剂的应用前景.%The borate coupling agent is a new-style coupling agent. Compared with traditional coupling agents, it has many new features. Boric acid ester coupling agent, which centers on boron atom, can be applied to surface modification of inorganic fillers containing boron and improve the compatibility of inorganic filler containing boron and polymer. It possesses the boron-oxygen skeleton,which can present great physical sorption capacity to borate whisker. In terms of modification borate whisker,boric acid ester coupling agent has a good modification effect. In recent years, domestic institutions have gained great progress in the synthesis and application of boric acid ester coupling agent, which is mainly used for the preparation of composite materials. The development status of borate coupling agent and the application in composite material at the present time is summarized. Further more, the application prospect of borate coupling agent is introduced.

  1. 硼酸镁晶须应用研究新进展%New Progress in Research on Application of Magnesium Borate Whisker

    Institute of Scientific and Technical Information of China (English)

    魏珂瑶; 周莉; 李玉玲

    2012-01-01

    硼酸镁晶须是继硼酸铝晶须后的又一高性能低成本的晶须,其原料广,具有成本低廉、良好的机械强度和电绝缘性以及无毒无害无污染等优异性能,可作为增强增韧材料添加到其他材料中,是一种应用前景广阔的晶须材料.随着社会对轻质、高效材料的需求越来越大,以及对硼酸镁晶须理论问题的不断深入研究和制备技术的不断开发与完善,可以预见,硼酸镁晶须产品将会展现出极为广阔的应用前景.综述了硼酸镁晶须表面改性问题及其做为填充材料增强金属、树脂、陶瓷等的应用.%The magnesium borate whisker is a high performance and low cost whisker following the aluminum borate whisker. It has large sources of raw materials, low cost, good mechanical strength and electrical insulation as well as non-toxic, pollution-free and other excellent properties which can be used as a reinforcing material to be added to other materials, and it is a whisker material of vast application prospect. Along with the more and more demands of the society for the light-weight and high-performance materials, the further study on the principle of magnesium borate whisker and the continuous development and improvement of preparation technology, it is predicted that the magnesium borate whisker products will exhibit a very broad application prospects. The surface modification of magnesium borate whisker is reviewed, as well as its applications in reinforcing metal, resin and ceramic as a filler material.

  2. 硼酸镁晶须在聚丙烯中的应用%Application of Magnesium Borate Whisker in Polypropylene

    Institute of Scientific and Technical Information of China (English)

    周莉; 徐新宇; 李玉玲; 赵园

    2012-01-01

    以硼酸、乙醇胺、甲基丙烯酰氯为主要原料,合成了新型可聚合硼酸酯偶联剂BE-1.利用BE-1在硼酸镁晶须表面引发聚合形成有机涂层,并用改性后的硼酸镁晶须制备了硼酸镁晶须/聚丙烯(PP)复合材料.检测结果如下:由红外测试结果可以推断,合成产物即为可聚合硼酸酯偶联剂BE-1;在水解稳定性测试中BE-1稳定时间大于960h,BE-1具有良好的溶解性及贮存性能;有机涂层形成的最佳反应温度为78℃,最佳反应时间为6h;BE-1改性硼酸镁晶须/PP复合材料拉伸强度、弯曲强度、热变形温度分别比纯PP提高了30%、40%和104%,分别比未改性硼酸镁晶须/PP复合材料提高了11.05%、23.52%、15.29%.%A novel polymerizable borate ester coupling agent (BE-1) was prepared by boric acid, eth-anolamine, and methacryloyl chloride. BE-1 was used in the magnesium borate whisker surface that formed the organic coatings by the polymerization, and PP/magnesium borate whisker composites were prepared by the modified magnesium borate whisker. The results revealed that IR test results can be inferred that synthetic product was boric acid ester polymer coupling agent BE-1. The hydrolytic stabilization time of BE-1 was longer than 960 h and the solubility and storage capacity of BE-1 was well. The best reaction temperature and time of organic coating was 78 X, and 6 h. Tensile strength, flexural strength, heat distortion temperature of the BE-1 modified whisker composites increased respectively by 30% , 40% and 104% compared with polypropylene which was increased respectively by 11.05%, 23.52% and 15.29% compared with unmodified magnesium borate whisker/PP.

  3. Photon-conversion and sensitization evaluation of Eu³⁺ in a borate glass system.

    Science.gov (United States)

    Tian, Y M; Shen, L F; Pun, E Y B; Lin, H

    2016-02-20

    Photon conversion is exhibited in a borate (LKZBSB) glass system containing Eu(3+), and the enhanced characteristic emissions of Eu(3+) with the codoping of Ce(3+) have been verified. A large Judd-Ofelt intensity parameter Ω2 of Eu(3+) indicates a high asymmetrical and strong covalent environment around rare-earth (RE) ions in LKZBSB glasses and spontaneous emission probability and a maximum emission cross section of the dominant 5D0→7F2 transition were derived to be 370  s(-1) and 1.28×10(-21)  cm2, respectively, revealing the potential UV→visible photon-conversion capacity of Eu(3+). Absolutely quantitative evaluation illustrates that Eu(3+) is a favorable photon-conversion center to achieve high photon-conversion efficiency. The addition of Ce(3+) is beneficial to realizing effective red emission of Eu(3+), which possesses commercial value by decreasing the dopant of expensive europium compounds. As an expectation, this photon-conversion LKZBSB glass system can promote the development of a photon downconversion layer for solar cells, which are particularly used in outer space with intense UV radiation. PMID:26906599

  4. Role of SrO on the bioactivity behavior of some ternary borate glasses and their glass ceramic derivatives.

    Science.gov (United States)

    Abdelghany, A M; Ouis, M A; Azooz, M A; ElBatal, H A; El-Bassyouni, G T

    2016-01-01

    Borate glasses containing SrO substituting both CaO and NaO were prepared and characterized for their bioactivity or bone bonding ability. Glass ceramic derivatives were prepared by thermal heat treatment process. FTIR, XRD and SEM measurements for the prepared glass and glass-ceramics before and after immersion in sodium phosphate solution for one and two weeks were carried out. The appearance of two IR peaks within the range 550-680cm(-1) after immersion in phosphate solution indicates the formation of hydroxyapatite or equivalent Sr phosphate layer. X-ray diffraction data agree with the FTIR spectral analysis. The solubility test was carried out for both glasses and glass ceramics derivatives in the same phosphate solution. The introduction of SrO increases the solubility for both glasses and glass ceramics and this is assumed to be due to the formation of Sr phosphate which is more soluble than calcium phosphate (hydroxyapatite). SEM images reveal varying changes in the surfaces of glass ceramics after immersion according to the SrO content.

  5. In vitro bioactivity of soda lime borate glasses with substituted SrO in sodium phosphate solution

    Directory of Open Access Journals (Sweden)

    Mohamed A. Marzouk

    2014-09-01

    Full Text Available Borate glasses with the basic composition 0.6B2O3·0.2Na2O·0.2CaO and SrO progressively substituting CaO were prepared and characterized for their bone-bonding ability. The obtained glasses were thermally treated and converted to their glass-ceramic derivatives. In this study, FTIR spectral analyses were done for the prepared glasses and glass-ceramics before and after immersion in a sodium phosphate solution for extended times. The appearance of two IR bands within the spectral range 550–680 cm-1 after immersion confirms the formation of hydroxyapatite. X-ray diffraction studies and scanning electron microscope analysis supported the obtained infrared spectroscopy results. The solubility test (measurements of the weight loss in aqueous sodium phosphate solution was conducted for measuring the dissolution of both glassy and crystalline derivatives to find out the role of SrO. The corrosion behaviour of the glasses and glass-ceramics indicate the increase of weight loss with the increase of SrO content. Different suggested proposals were introduced to explain this abnormal behaviour.

  6. Role of SrO on the bioactivity behavior of some ternary borate glasses and their glass ceramic derivatives

    Science.gov (United States)

    Abdelghany, A. M.; Ouis, M. A.; Azooz, M. A.; ElBatal, H. A.; El-Bassyouni, G. T.

    2016-01-01

    Borate glasses containing SrO substituting both CaO and NaO were prepared and characterized for their bioactivity or bone bonding ability. Glass ceramic derivatives were prepared by thermal heat treatment process. FTIR, XRD and SEM measurements for the prepared glass and glass-ceramics before and after immersion in sodium phosphate solution for one and two weeks were carried out. The appearance of two IR peaks within the range 550-680 cm-1 after immersion in phosphate solution indicates the formation of hydroxyapatite or equivalent Sr phosphate layer. X-ray diffraction data agree with the FTIR spectral analysis. The solubility test was carried out for both glasses and glass ceramics derivatives in the same phosphate solution. The introduction of SrO increases the solubility for both glasses and glass ceramics and this is assumed to be due to the formation of Sr phosphate which is more soluble than calcium phosphate (hydroxyapatite). SEM images reveal varying changes in the surfaces of glass ceramics after immersion according to the SrO content.

  7. Structural studies of some phospho-borate glasses using ultrasonic pulse-echo technique, DSC and IR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Gaafar, M.S., E-mail: mohamed_s_gaafar@hotmail.co [Ultrasonic Laboratory, National Institute for Standards, Tersa Street, P.O. Box 136, El-Haram, El-Giza 12211 (Egypt); Afifi, H.A. [Ultrasonic Laboratory, National Institute for Standards, Tersa Street, P.O. Box 136, El-Haram, El-Giza 12211 (Egypt); Mekawy, M.M. [Thermometry Laboratory, National Institute for Standards, Tersa Street, P.O. Box 136, El-Haram, El-Giza 12211 (Egypt)

    2009-06-01

    Glasses in the system (95-x) [0.25 Na{sub 2}O-0.75 B{sub 2}O{sub 3}]-x P{sub 2}O{sub 5}-5 Fe{sub 2}O{sub 3} (0<=x<=15 mol%), have been prepared by the melt quenching technique. Elastic properties and FT-IR spectroscopic studies have been employed to study the role of P{sub 2}O{sub 5} on the structure of the glass system. Elastic properties Poisson's ratio, micro-hardness and Debye temperature have been investigated using sound wave velocity measurements at 4 MHz (both longitudinal and shear) at room temperature. The results showed that the density and the molar volume increase as both sound velocities and the determined glass transition temperatures decrease with increasing the contents of P{sub 2}O{sub 5}. Infrared spectra of the glasses reveal that the borate network consists of diborate units and is affected by the increase in the concentration of P{sub 2}O{sub 5} content as a second network former. These results are interpreted in terms of the replacement of the diborate units with B-O-B bridges by phosphate units with non-bridging oxygens (NBOs). Therefore, the elastic moduli are observed to decrease with the increase in P{sub 2}O{sub 5} content.

  8. Compatibility of lithium difluoro(sulfato)borate-based electrolyte for LiMn2O4 cathode

    Science.gov (United States)

    Li, Shiyou; Liu, Jinliang; Li, Lingxia; Li, Xiaopeng; Jing, Jie; Cui, Xiaoling

    2015-03-01

    Lithium difluoro(sulfato)borate (LiBF2SO4) is investigated as a lithium salt for non-aqueous electrolytes for LiMn2O4 cathode in lithium-ion batteries. Inductively coupled plasma-atomic emission spectrometry analysis is used to analyze the Mn dissolution. Scanning electron microscopy and AC impedance measurements analysis are used to analyze the formation of the surface film on the surface of LiMn2O4 cathode. These results demonstrate that LiBF2SO4-based electrolyte favourably facilitates the formation of an effective and conductive interface film on the cathode surface to improve the stabilization of cathode/electrolyte interface. Besides, LiMn2O4 cells using LiBF2SO4-based electrolyte exerts several advantages, such as stable cycling performance, low cell impedance, low polarization resistance, and good rate performance. It suggests that LiBF2SO4-based electrolyte has good compatibility with LiMn2O4 cathode, and LiBF2SO4 would be a very promising lithium salt for LiMn2O4 cathode in lithium-ion batteries.

  9. Repassivation behavior of 316L stainless steel in borate buffer solution: Kinetics analysis of anodic dissolution and film formation

    Science.gov (United States)

    Xu, Haisong; Sun, Dongbai; Yu, Hongying

    2015-12-01

    The repassivation behavior of metals or alloys after oxide film damage determines the development of local corrosion and corrosion resistance. In this work, the repassivation kinetics of 316L stainless steel (316L SS) are investigated in borate buffer solution (pH 9.1) by using the abrading electrode technique. The current densities flowing from bare 316L SS surface are measured by potentiostatic method and analyzed to characterize repassivation kinetics. The initial stages of current decay (t Avrami kinetics. Then the two independent components are analyzed individually. The film formation rate and the thickness of film are compared in different applied potential. It is shown that anodic dissolution dominates the repassivation for a short time during the early times, and a higher applied potential will promote the anodic dissolution of metal. The film growth rate increases slightly with increasing in potential. Correspondingly, increase in applied potential from 0 VSCE to 0.8 VSCE results in thicker monolayer, which covers the whole bare surface at the time of θ = 1. The electric field strengths through the thin passive film could reach 3.97 × 106 V cm-1.

  10. Magnetoelectric and magnetic properties of aluminum borates Ho1 - x Nd x Al3(BO3)4

    Science.gov (United States)

    Volkov, N. V.; Gudim, I. A.; Demidov, A. A.; Eremin, E. V.

    2015-03-01

    The magnetoelectric and magnetic properties of substituted aluminum borates Ho1 - x Nd x Al3(BO3)4 have been studied experimentally and theoretically. A large magnetoelectric effect exceeding all known values in isostructural compounds except for HoAl3(BO3)4 has been found. The magnetoelectric polarization of Ho0.8Nd0.2Al3(BO3)4 and Ho0.5Nd0.5Al3(BO3)4 at T = 5 K in a field of 9 T is Δ P ab ( B b ) ≈ -2630 and 1380 μC/m2, respectively. A theoretical consideration based on the crystal field model for the rare-earth ion made it possible to interpret all measured properties within the unified approach. The crystal field parameters have been determined. The temperature (3-300 K) and field (up to 9 T) dependences of the magnetization and the temperature (5-100 K) and field (up to 9 T) dependences of the polarization have been described. The studied properties of Ho1 - x Nd x Al3(BO3)4 have been compared with those of HoAl3(BO3)4 demonstrating record-high polarization values.

  11. Corrosion Behavior of Ultra-fine Grained 1050 Aluminum Alloy Fabricated by ARB Process in a Buffer Borate Solution

    Science.gov (United States)

    Fattah-alhosseini, A.; Gashti, S. O.

    2015-09-01

    Accumulative roll bonding (ARB) has been used as a severe plastic deformation process for the industrial production of ultra-fine grained (UFG) and nano-crystalline sheets with excellent mechanical properties. In the present study, the effect of the ARB process on the corrosion behavior of UFG and nano-crystalline 1050 aluminum alloy in a buffer borate solution (pH 5.5) has been investigated. The result of microhardness tests revealed that microhardness values increase with an increasing number of ARB cycles. A sharp increase in microhardness is seen after three ARB cycles, whereas moderate additional increases are observed afterward for up to nine cycles. Also, the XRD results showed that the mean crystallite size decreased to about 91 nm after nine cycles. The potentiodynamic plots show that as a result of ARB, the corrosion behavior of the UFG and nano-crystalline specimens improves, compared to the annealed 1050 aluminum alloy. Moreover, electrochemical impedance spectroscopy measurements showed that the polarization resistance increases with an increasing number of ARB cycles.

  12. "Third-Generation"-Type Functional Tris(2-pyridyl)borate Ligands and Their Transition-Metal Complexes.

    Science.gov (United States)

    Jeong, So Yi; Lalancette, Roger A; Lin, Huina; Lupinska, Patrycja; Shipman, Patrick O; John, Alexandra; Sheridan, John B; Jäkle, Frieder

    2016-04-01

    Phenyltris(2-pyridyl)borates (Tpyb) are a promising class of tripodal "scorpionate"-type ligands with potential utility in the development of transition-metal complexes with interesting optical, electronic, or magnetic properties and as building blocks to metallosupramolecular polymers. We report here a new class of "third-generation"-type Tpyb ligands that contain different functional groups attached to the boron-bound aryl moiety. The synthesis, characterization, and metal-ion complexation behavior of ligands with iodo and trimethylsilyl groups are discussed. The electrochemical and absorption characteristics of the corresponding low-spin iron(II) and ruthenium(II) complexes are compared. We demonstrate the further elaboration of iodo derivatives with alkynes via Sonogashira-Hagihara coupling, a process that proceeds with high yield for the iron(II) and ruthenium(II) complexes but not for the free ligand. Borylation of the silyl-substituted ruthenium(II) complex with BBr3 was also investigated. In addition to the expected borylation product Ru(Tpyb-Bpin)2, the replacement of one (major product) or two phenyl groups is observed, suggesting that electrophilic borylation occurs at both the C(Ph)-Si and the C(Ph)-B aromatic carbon atoms. The successful attachment of a range of different functional groups at the periphery of the Tpyb metal complexes is expected to provide opportunities to access new polymeric materials via C-C coupling or click-type reactions. PMID:26991520

  13. Thermal and optical properties of Nd{sup 3+} doped lead zinc borate glasses—Influence of alkali metal ions

    Energy Technology Data Exchange (ETDEWEB)

    Sasi Kumar, M.V.; Rajesh, D.; Balakrishna, A. [Department of Physics, Sri Venkateswara University, Tirupati 517502 (India); Ratnakaram, Y.C., E-mail: ratnakaramsvu@gmail.com [Department of Physics, Sri Venkateswara University, Tirupati 517502 (India)

    2013-04-15

    In the present investigation a new series of six different Nd{sup 3+} doped alkali and mixed alkali (Li, Na, K, Li–Na, Li–K and Na–K) heavy metal (PbO and ZnO) borate glasses were prepared using the melt quenching technique. The amorphous nature of the glass systems has been identified based on the X-ray diffraction analysis. The glass transition studies were carried out using differential scanning calorimetry (DSC). Optical properties were studied by measuring the optical absorption and near infrared luminescence spectra. The Judd–Ofelt (J–O) theory has been applied to calculate J–O intensity parameters, Ω{sub λ} (λ=2, 4 and 6) and in turn used to estimate radiative properties of certain transitions. Spectroscopic parameters such as transition probabilities (A{sub T}), branching ratios (β), radiative lifetimes (τ{sub R}) and integrated absorption cross-sections (Σ) were calculated using J–O intensity parameters for all transitions. Using emission spectra, experimental branching ratios and stimulated emission cross-sections (σ{sub P}) are obtained for all the observed emission transitions.

  14. Judd-Ofelt analysis and spectral properties of Dy3+ ions doped niobium containing tellurium calcium zinc borate glasses

    Science.gov (United States)

    Ravi, O.; Reddy, C. Madhukar; Reddy, B. Sudhakar; Deva Prasad Raju, B.

    2014-02-01

    Niobium containing tellurium calcium zinc borate (TCZNB) glasses doped with different concentrations of Dy3+ ions were prepared by the melt quenching method and their optical properties have been studied. The Judd-Ofelt (J-O) intensity parameters Ωt (t=2, 4 and 6) were calculated using the least square fit method. Based on the magnitude of Ω2 parameter the hypersensitivity of 6H15/2→6F11/2 has also been discussed. From the evaluated J-O intensity parameters as well as from the emission and lifetime measurements, radiative transition properties such as radiative transition probability rates and branching ratios were calculated for 4F9/2 excited level. It is found that for Dy3+ ion, the transition 4F9/2→6H13/2 shows highest emission cross-section at 1.0 mol% TCZNB glass matrix. From the visible luminescence spectra, yellow to blue (Y/B) intensity ratios and chromaticity color coordinates were also estimated. The TCZNB glasses exhibit good luminescence properties and are suitable for generation of white light.

  15. Thermal and optical properties of Nd3+ doped lead zinc borate glasses—Influence of alkali metal ions

    Science.gov (United States)

    Sasi Kumar, M. V.; Rajesh, D.; Balakrishna, A.; Ratnakaram, Y. C.

    2013-04-01

    In the present investigation a new series of six different Nd3+ doped alkali and mixed alkali (Li, Na, K, Li-Na, Li-K and Na-K) heavy metal (PbO and ZnO) borate glasses were prepared using the melt quenching technique. The amorphous nature of the glass systems has been identified based on the X-ray diffraction analysis. The glass transition studies were carried out using differential scanning calorimetry (DSC). Optical properties were studied by measuring the optical absorption and near infrared luminescence spectra. The Judd-Ofelt (J-O) theory has been applied to calculate J-O intensity parameters, Ωλ (λ=2, 4 and 6) and in turn used to estimate radiative properties of certain transitions. Spectroscopic parameters such as transition probabilities (AT), branching ratios (β), radiative lifetimes (τR) and integrated absorption cross-sections (Σ) were calculated using J-O intensity parameters for all transitions. Using emission spectra, experimental branching ratios and stimulated emission cross-sections (σP) are obtained for all the observed emission transitions.

  16. Thermal and optical properties of Nd3+ doped lead zinc borate glasses—Influence of alkali metal ions

    International Nuclear Information System (INIS)

    In the present investigation a new series of six different Nd3+ doped alkali and mixed alkali (Li, Na, K, Li–Na, Li–K and Na–K) heavy metal (PbO and ZnO) borate glasses were prepared using the melt quenching technique. The amorphous nature of the glass systems has been identified based on the X-ray diffraction analysis. The glass transition studies were carried out using differential scanning calorimetry (DSC). Optical properties were studied by measuring the optical absorption and near infrared luminescence spectra. The Judd–Ofelt (J–O) theory has been applied to calculate J–O intensity parameters, Ωλ (λ=2, 4 and 6) and in turn used to estimate radiative properties of certain transitions. Spectroscopic parameters such as transition probabilities (AT), branching ratios (β), radiative lifetimes (τR) and integrated absorption cross-sections (Σ) were calculated using J–O intensity parameters for all transitions. Using emission spectra, experimental branching ratios and stimulated emission cross-sections (σP) are obtained for all the observed emission transitions

  17. Strong-Coupled Cobalt Borate Nanosheets/Graphene Hybrid as Electrocatalyst for Water Oxidation Under Both Alkaline and Neutral Conditions.

    Science.gov (United States)

    Chen, Pengzuo; Xu, Kun; Zhou, Tianpei; Tong, Yun; Wu, Junchi; Cheng, Han; Lu, Xiuli; Ding, Hui; Wu, Changzheng; Xie, Yi

    2016-02-12

    Developing highly active catalysts for the oxygen evolution reaction (OER) is of paramount importance for designing various renewable energy storage and conversion devices. Herein, we report the synthesis of a category of Co-Pi analogue, namely cobalt-based borate (Co-Bi ) ultrathin nanosheets/graphene hybrid by a room-temperature synthesis approach. Benefiting from the high surface active sites exposure yield, enhanced electron transfer capacity, and strong synergetic coupled effect, this Co-Bi NS/G hybrid shows high catalytic activity with current density of 10 mA cm(-2) at overpotential of 290 mV and Tafel slope of 53 mV dec(-1) in alkaline medium. Moreover, Co-Bi NS/G electrocatalysts also exhibit promising performance under neutral conditions, with a low onset potential of 235 mV and high current density of 14.4 mA cm(-2) at 1.8 V, which is the best OER performance among well-developed Co-based OER electrocatalysts to date. Our finding paves a way to develop highly active OER electrocatalysts. PMID:26757358

  18. Separation of boron from borated paraffin wax by pyrohydrolysis and alkali extraction methods and its determination using ion chromatography.

    Science.gov (United States)

    Raut, Vaibhavi Vishwajeet; Jeyakumar, Subbiah; Shah, Dipti Jayesh; Thakur, Uday Kumar; Tomar, Bhupendra Singh; Ramakumar, Karanam Lakshminarayana

    2015-01-01

    A method based on the pyrohydrolysis extraction of boron and its quantification with ion chromatography was proposed for paraffin waxes borated with H3BO3 and B4C. The optimum pyrohydrolysis conditions were identified. Wax samples were mixed with U3O8, which prevents the sample from flare up, and also accelerates the extraction of boron. Pyrohydrolysis was carried out with moist O2 at 950°C for 60 and 90 min for wax with H3BO3 and wax with B4C, respectively. Two simple methods of separation based on alkali extraction and melting wax in alkali were also developed exclusively for wax with H3BO3. In all the separations, the recovery of B was above 98%. During IC separation, B was separated as boron-mannitol anion complex. Linear calibration was obtained it between 0.1 and 50 ppm of B, and LOD was calculated as 5 ppb (S/N = 3). The reproducibility was better than 5% (RSD). PMID:25765277

  19. Hybrid effects of zirconia nanoparticles with aluminum borate whiskers on mechanical properties of denture base resin PMMA.

    Science.gov (United States)

    Zhang, Xiu-Yin; Zhang, Xin-Jing; Huang, Zhuo-Li; Zhu, Bang-Shang; Chen, Rong-Rong

    2014-01-01

    The aim of this study was to investigate the hybrid effects of ZrO₂ nanoparticles (nano-ZrO₂) and aluminum borate whiskers (ABWs) on flexural strength and surface hardness of denture base resin, polymethyl methacrylate (PMMA). Both nano-ZrO₂ and ABWs were modified by silane coupling agent (Z6030) before being mixed with PMMA. Various amounts of silanized nano-ZrO₂ and ABWs were mixed with PMMA to prepare ZrO₂-ABW/PMMA composites. Flexural strength and surface hardness were evaluated using three- point bending test and Vickers hardness test respectively. Fractured surfaces were also observed by scanning electron microscopy (SEM). The mechanical behaviors of silanized ZrO₂-ABW/PMMA composites were significantly improved. Flexural strength reached a maximum value of 108.01 ± 5.54 MPa when 2 wt% of nano-ZrO₂ was mixed with ABWs at a ZrO₂/ABW ratio of 1:2, amounting to an increase of 52% when compared with pure PMMA. Surface hardness achieved a maximum value of 22.50 ± 0.86 MPa when 3 wt% of nano-ZrO₂ was mixed with ABWs at the same ZrO₂/ABW ratio, which was an increase of 27% when compared with pure PMMA.

  20. Effect of Surfactants on the Structure and Morphology of Magnesium Borate Hydroxide Nanowhiskers Synthesized by Hydrothermal Route

    Directory of Open Access Journals (Sweden)

    Kulkarni Shrinivas

    2009-01-01

    Full Text Available Abstract Magnesium borate hydroxide (MBH nanowhiskers were synthesized using a one step hydrothermal process with different surfactants. The effect surfactants have on the structure and morphology of the MBH nanowhiskers has been investigated. The X-ray diffraction profile confirms that the as-synthesized material is of single phase, monoclinic MgBO2(OH. The variations in the size and shape of the different MBH nanowhiskers have been discussed based on the surface morphology analysis. The annealing of MBH nanowhiskers at 500 °C for 4 h has significant effect on the crystal structure and surface morphology. The UV–vis absorption spectra of the MBH nanowhiskers synthesized with and without surfactants show enhanced absorption in the low-wavelength region, and their optical band gaps were estimated from the optical band edge plots. The photoluminescence spectra of the MBH nanowhiskers produced with and without surfactants show broad emission band with the peak maximum at around 400 nm, which confirms the dominant contribution from the surface defect states.

  1. Synthesis of luminescent ethynyl-extended regioisomers of borate complexes based on 2-(2'-hydroxyphenyl)benzoxazole.

    Science.gov (United States)

    Massue, Julien; Frath, Denis; Retailleau, Pascal; Ulrich, Gilles; Ziessel, Raymond

    2013-04-22

    A series of thirteen luminescent tetrahedral borate complexes based on the 2-(2'-hydroxyphenyl)benzoxazole (HBO) core is presented. Their synthesis includes the incorporation of an ethynyl fragment by Sonogashira cross-coupling reaction, with the goal of extending the conjugation and consequently redshifting their emission wavelength. Different regioisomers, substituted in the 3-, 4-, or 5-position of the phenolate side of the HBO core, were studied in order to compare their photophysical properties. The complexes were characterized by X-ray diffraction and NMR, UV/Vis, and emission spectroscopy in solution and in the solid state. In all cases, complexation to boron leads to a donor-acceptor character that impacts their photophysical properties. Complexes with a 3- or 5-substituted fragment display mild to pronounced internal charge transfer (ICT), a feature strengthened by the presence of p-dibutylaminophenylacetylene in the molecular structure, protonation of the nitrogen atom of which leads to a significant blueshift and an increase in quantum yield. On the contrary, when the ethynyl module is grafted on the 4-position, narrow, structured, symmetrical absorption/emission bands are observed. Moreover, the fact that protonation has little effect on the emission maximum wavelength reveals singlet excited-state decay. Solid-state emission properties reveal a redshift compared to solution, explained by tight packing of the π-conjugated systems and the high planarity of the dyes. Subsequent connection of these complexes to other photoactive subunits (BODIPY, Boranil) provides dyads in which efficient cascade energy transfer is observed.

  2. Poly(vinyl Alcohol) Borate Gel Polymer Electrolytes Prepared by Electrodeposition and Their Application in Electrochemical Supercapacitors.

    Science.gov (United States)

    Jiang, Mengjin; Zhu, Jiadeng; Chen, Chen; Lu, Yao; Ge, Yeqian; Zhang, Xiangwu

    2016-02-10

    Gel polymer electrolytes (GPEs) have been studied for preparing flexible and compact electrochemical energy storage devices. However, the preparation and use of GPEs are complex, and most GPEs prepared through traditional methods do not have good wettability with the electrodes, which retard them from achieving their performance potential. In this study, these problems are addressed by conceiving and implementing a simple, but effective, method of electrodepositing poly(vinyl alcohol) potassium borate (PVAPB) GPEs directly onto the surfaces of active carbon electrodes for electrochemical supercapacitors. PVAPB GPEs serve as both the electrolyte and the separator in the assembled supercapacitors, and their scale and shape are determined solely by the geometry of the electrodes. PVAPB GPEs have good bonding to the active electrode materials, leading to excellent and stable electrochemical performance of the supercapacitors. The electrochemical performance of PVAPB GPEs and supercapacitors can be manipulated simply by adjusting the concentration of KCl salt used during the electrodeposition process. With a 0.9 M KCl concentration, the as-prepared supercapacitors deliver a specific capacitance of 65.9 F g(-1) at a current density of 0.1 A g(-1) and retain more than 95% capacitance after 2000 charge/discharge cycles at a current density of 1 A g(-1). These supercapacitors also exhibit intelligent high voltage self-protection function due to the electrolysis-induced cross-linking effect of PVAPB GPEs. PMID:26788748

  3. Structural studies of some phospho-borate glasses using ultrasonic pulse-echo technique, DSC and IR spectroscopy

    International Nuclear Information System (INIS)

    Glasses in the system (95-x) [0.25 Na2O-0.75 B2O3]-x P2O5-5 Fe2O3 (0≤x≤15 mol%), have been prepared by the melt quenching technique. Elastic properties and FT-IR spectroscopic studies have been employed to study the role of P2O5 on the structure of the glass system. Elastic properties Poisson's ratio, micro-hardness and Debye temperature have been investigated using sound wave velocity measurements at 4 MHz (both longitudinal and shear) at room temperature. The results showed that the density and the molar volume increase as both sound velocities and the determined glass transition temperatures decrease with increasing the contents of P2O5. Infrared spectra of the glasses reveal that the borate network consists of diborate units and is affected by the increase in the concentration of P2O5 content as a second network former. These results are interpreted in terms of the replacement of the diborate units with B-O-B bridges by phosphate units with non-bridging oxygens (NBOs). Therefore, the elastic moduli are observed to decrease with the increase in P2O5 content.

  4. Secondary neutron dose measurement for proton eye treatment using an eye snout with a borated neutron absorber

    International Nuclear Information System (INIS)

    We measured and assessed ways to reduce the secondary neutron dose from a system for proton eye treatment. Proton beams of 60.30 MeV were delivered through an eye-treatment snout in passive scattering mode. Allyl diglycol carbonate (CR-39) etch detectors were used to measure the neutron dose in the external field at 0.00, 1.64, and 6.00 cm depths in a water phantom. Secondary neutron doses were measured and compared between those with and without a high-hydrogen–boron-containing block. In addition, the neutron energy and vertices distribution were obtained by using a Geant4 Monte Carlo simulation. The ratio of the maximum neutron dose equivalent to the proton absorbed dose (H(10)/D) at 2.00 cm from the beam field edge was 8.79 ± 1.28 mSv/Gy. The ratio of the neutron dose equivalent to the proton absorbed dose with and without a high hydrogen-boron containing block was 0.63 ± 0.06 to 1.15 ± 0.13 mSv/Gy at 2.00 cm from the edge of the field at depths of 0.00, 1.64, and 6.00 cm. We found that the out-of-field secondary neutron dose in proton eye treatment with an eye snout is relatively small, and it can be further reduced by installing a borated neutron absorbing material

  5. ORIGIN OF THE BORATE DEPOSITS UNDER THE CONDITION OF HYPERGENESIS%表生作用条件下硼酸盐矿床的形成问题

    Institute of Scientific and Technical Information of China (English)

    孙大鹏; 高章洪; 马育华; 蔡克勤; 帅开业; 高建华

    2002-01-01

    沉积硼酸盐矿床在自然界分布相当广泛,主要见于南、北美和我国青藏高原的盐湖中、美国和土耳其某些第三纪沉积盆地中,以及欧洲某些古代海相盐矿床中.为了研究其形成问题,从70年代开始,我们利用青藏高原盐湖卤水和泉水进行了许多模拟实验工作.从40~50个样品中获得了大量钠硼酸盐、纳钙硼酸盐、镁硼酸盐和含氯化镁的镁硼酸盐复盐.这对于阐明表生作用条件下硼酸盐矿床的形成是非常重要的.实验和研究结果证明:1)与地热和火山活动有关的水体是硼酸盐矿床形成的物质来源;2)硼酸盐矿床可形成于Na、K、Mg//Cl、SO4·H2O和Na、K//Cl、SO4、HCO3、CO3·H2O不同水盐平衡体系的不同富硼水体中(盐度:1.27~41.4%,B2O3含量:0.05~2.97%);3)硼酸盐矿床通常形成于稳定平衡条件下,而不是介稳平衡条件下(蒸发过程中);4)低温条件有利于硼酸盐自水体中析出;5)硼酸盐矿床的形成与水体的化学类型、pH值和硼含量有密切关系;6)我们实验中所获的硼酸盐反映了天然硼酸盐矿床形成的原始条件.不仅揭示了大陆盐湖硼酸盐矿床的形成,也揭示了古代海相盐矿床硼酸盐的成因.%Abstract: The distribution of sedimentary boron deposits is relatively widespread in nature,They are mainly found in recent salt lakes of the North and South America and the Qinghai-Xizang(Tibet) plateau in China,some Tertiary sedimentary basins in United States of America and Turkey and in some old salt deposits in Europe.However,their origins have not been studied in detail yet.In order to investigate their formation,a lot of simulating experiments have been done using the natural brines and spring water of the saline lakes on Qinghai-Xizang plateau from1970s.Na-borate,Na-Ca borate,Mg-borates and Mg-borate contained MgCl2 have been obtained from 40-50 experimental samples.It is very important for illustrating the origins of the

  6. Stability and electronic properties of groups IIB to VB metal ions in unusual oxidation states and the 2S /SUB 1/2/ electronic state in lithium borate glasses

    International Nuclear Information System (INIS)

    The authors study lithium borate glasses containing groups IIB to VB metal oxides. Chemically pure reagents were used to synthesize the glasses which were subjected to gamma-rays at 77 and 300 K with doses of up to 100 kR. The EST spectra were recorded on a Varian E-12 spectrometer in the 3 cm CW frequency region with a 100 kHz magnetic field modulation. It was established that after gamma-irradiation at 77 and 300 K of the lithium borate glass system containing up to 10% of cadmium, tin, thalium, and lead oxides, additional ESR lines arise in the free electron g factor region. The authors have determined the missing ESR spectra for nonactivated lithium borate glasses by studying glasses with additions of Zn, Ge, and Sb oxides

  7. Cálculo del Costo Comparativo de la Obtención de Concentrados de Boratos Comparative Cost Calculation in the Obtaining of Borate Concentrates

    Directory of Open Access Journals (Sweden)

    Horacio R Flores

    2008-01-01

    Full Text Available Este trabajo muestra la similitud existente entre los diagramas de flujo, balances de materia y equipos empleados en la concentración de boratos para obtener refinados y boratos de alto valor agregado. Se usa una planilla de cálculo para determinar el costo de producción para distintas condiciones de operación, a fin de determinar la oportunidad y conveniencia de cambiar el producto final, empleando la misma planta productora. Se analiza un caso particular que compara la producción de 10 tn/hr de concentrado de ulexita o de hidroboracita. Se obtiene un costo de producción por tonelada de B2O3 de 94.3 US dólares para la concentración de ulexita, que se reduce a 67.5 US dólares para la concentración de hidroboracita. Se concluye que el método propuesto es una herramienta que facilita el análisis económico del proceso productivo estudiado.This paper presents the similitude found between flow sheets, material balances and equipments employed in the concentration of borates, to obtain base refined borates and to obtain high added value borates. Spread sheet calculations are used to determine the production costs for different operating conditions and to analyze the opportunity and convenience of changing the final product, using the same process plant. A study case is considered in which 10 tn/hr of ulexite concentrate or the same amount of hydroboracite are produced. The cost per ton of B2O3 was 94.3 US dollars for the concentrated ulexite and 67.5 US dollars for concentrated hydroboracite. It is concluded that the proposed method is an useful tool for the economic analysis of the productive process considered in this study.

  8. Simultaneous determination of trace amounts of borate, chloride and fluoride in nuclear fuels employing ion chromatography (IC) after their extraction by pyrohydrolysis.

    Science.gov (United States)

    Jeyakumar, S; Raut, Vaibhavi V; Ramakumar, K L

    2008-09-15

    An accurate and sensitive method based on the combination of pyrohydrolysis-ion chromatography (PH-IC) is proposed for the simultaneous separation and determination of boron as borate, chloride and fluoride in nuclear fuels such as U(3)O(8), (Pu,U)C and Pu-alloys. The determination is based on the initial pyrohydrolytic extraction of B, Cl and F from the samples as boric acid, HCl and HF, respectively, which are subsequently separated by ion chromatography (IC). The proposed method significantly improves the existing analytical methodology as it combines the determination of boron, a critical trace constituent in nuclear materials, along with F(-) and Cl(-) for chemical quality control measurements. Various experimental parameters were optimized to achieve maximum recoveries of the analytes during the pyrohydrolysis and to get better ion chromatographic (IC) separation of borate, F(-) and Cl(-) along with other anions such as CH(3)COO(-), NO(2)(-), NO(3)(-), Br(-), PO(4)(3-) and SO(4)(2-). Recoveries of more than 93% could be obtained for all the analytes in the sample (0.5-1.5 g) at 1200+/-25K and distilled with pre-heated steam at the flow rate of 0.3 mL/min. An isocratic elution with a mobile phase of 0.56 M d-mannitol in 6.5mM NaHCO(3) was used for the IC separation. The detection limits for B (as borate), F(-) and Cl(-) were 24, 13 and 25 microgL(-1), respectively. Precision of about 5% was achieved for determination of boron, Cl(-) and F(-) in the samples containing 1-5 ppm(w) of boron, and 10-25 ppm(w) of Cl and F. The method was validated with reference materials and successfully applied to the nuclear fuels. The methodology is easy to adapt on routine basis. PMID:18761185

  9. Buffering Capacity of Fast-Growing Species and Curing Time of UF Resin Modified With Zinc Borate and Monoammonium Phosphate

    Directory of Open Access Journals (Sweden)

    Izran Kamal

    2010-01-01

    Full Text Available Problem statement: Occupying a suitable hot pressing time for particleboard fabrication seems very tricky for manufacturers of the wood-based panel. Longer or shorter pressing times can affect physical and mechanical properties of the produced particleboards and that is why extra care should be given on this matter. Longer pressing time can cause resin in a particleboard to over-cure whereas shorter pressing time can cause insufficient curing of the resin. Determination of hot pressing time is influenced by the type of filler and chemical used. The acidity or alkalinity of a filler and chemical can lengthen or shorten the time taken by the resin to cure. These parameters are usually assessed using buffering capacity test and curing time test. In this study, the two analyses were occupied to assess acidity or alkalinity of kenaf, Shorea macrophylla and Acacia mangium as well as the effect of fire retardants (zinc borate and monoammonium phosphate to the curing rate of urea formaldehyde resin. Determine acidity or alkalinity of the wood particles through buffering capacity test. The effect of the fire retardants to the curing of Urea Formaldehyde (UF resin was also studied. Approach: For buffering capacity test, the wood particles were extracted. Then, the extracts were separated into two parts. One part was tested with sodium hydroxide (NaOH and another part was tested with sulphuric acid (H2SO4. Sodium hydroxide was added into the extracts until they reached pH 11. The other part was added with sulphuric acid until they reached pH 3. The pH value was recorded each time 5 mL chemicals added. The acidity of the plants was observed by looking at the volume of sulphuric acid needed to reduce their pH to 3, whereas alkalinity was evaluated by looking at the volume of sodium hydroxide used to increase their pH to 11. Curing times of UF resin added or not added with fire retardants were calculated in second (sec. Results: Buffering capacity study

  10. Compatibility of lithium difluoro(sulfato)borate-based electrolyte for LiMn{sub 2}O{sub 4} cathode

    Energy Technology Data Exchange (ETDEWEB)

    Li, Shiyou; Liu, Jinliang; Li, Lingxia; Li, Xiaopeng; Jing, Jie; Cui, Xiaoling, E-mail: xlcuilw@163.com

    2015-03-01

    Highlights: • LiBF{sub 2}SO{sub 4} was investigated as a novel salt for advanced lithium-ion batteries. • LiBF{sub 2}SO{sub 4}-EC/DEC shows excellent film-forming characteristic on the surface of LiMn{sub 2}O{sub 4}. • LiBF{sub 2}SO{sub 4}-based electrolyte has good compatibility with LiMn{sub 2}O{sub 4} cathode. - Abstract: Lithium difluoro(sulfato)borate (LiBF{sub 2}SO{sub 4}) is investigated as a lithium salt for non-aqueous electrolytes for LiMn{sub 2}O{sub 4} cathode in lithium-ion batteries. Inductively coupled plasma-atomic emission spectrometry analysis is used to analyze the Mn dissolution. Scanning electron microscopy and AC impedance measurements analysis are used to analyze the formation of the surface film on the surface of LiMn{sub 2}O{sub 4} cathode. These results demonstrate that LiBF{sub 2}SO{sub 4}-based electrolyte favourably facilitates the formation of an effective and conductive interface film on the cathode surface to improve the stabilization of cathode/electrolyte interface. Besides, LiMn{sub 2}O{sub 4} cells using LiBF{sub 2}SO{sub 4}-based electrolyte exerts several advantages, such as stable cycling performance, low cell impedance, low polarization resistance, and good rate performance. It suggests that LiBF{sub 2}SO{sub 4}-based electrolyte has good compatibility with LiMn{sub 2}O{sub 4} cathode, and LiBF{sub 2}SO{sub 4} would be a very promising lithium salt for LiMn{sub 2}O{sub 4} cathode in lithium-ion batteries.

  11. The effect of the cation alkyl chain length on density and diffusion in dialkylpyrrolidinium bis(mandelato)borate ionic liquids.

    Science.gov (United States)

    Filippov, Andrei; Taher, Mamoun; Shah, Faiz Ullah; Glavatskih, Sergei; Antzutkin, Oleg N

    2014-12-28

    The physicochemical properties of ionic liquids are strongly affected by the selective combination of the cations and anions comprising the ionic liquid. In particular, the length of the alkyl chains of ions has a clear influence on the ionic liquid's performance. In this paper, we study the self-diffusion of ions in a series of halogen-free boron-based ionic liquids (hf-BILs) containing bis(mandelato)borate anions and dialkylpyrrolidinium cations with long alkyl chains CnH2n+1 with n from 4 to 14 within a temperature range of 293-373 K. It was found that the hf-BILs with n = 4-7 have very similar diffusion coefficients, while hf-BILs with n = 10-14 exhibit two liquid sub-phases in almost the entire temperature range studied (293-353 K). Both liquid sub-phases differ in their diffusion coefficients, while values of the slower diffusion coefficients are close to those of hf-BILs with shorter alkyl chains. To explain the particular dependence of diffusion on the alkyl chain length, we examined the densities of the hf-BILs studied here. It was shown that the dependence of the density on the number of CH2 groups in long alkyl chains of cations can be accurately described using a "mosaic type" model, where regions of long alkyl chains of cations (named 'aliphatic' regions) and the residual chemical moieties in both cations and anions (named 'ionic' regions) give additive contributions. Changes in density due to an increase in temperature and the number of CH2 groups in the long alkyl chains of cations are determined predominantly by changes in the free volume of the 'ionic' regions, while 'aliphatic' regions are already highly compressed by van der Waals forces, which results in only infinitesimal changes in their free volumes with temperature. PMID:25372279

  12. Theoretical investigation, biological evaluation and VEGFR2 kinase studies of metal(II) complexes derived from hydrotris(methimazolyl)borate.

    Science.gov (United States)

    Jayakumar, S; Mahendiran, D; Srinivasan, T; Mohanraj, G; Kalilur Rahiman, A

    2016-02-01

    The reaction of soft tripodal scorpionate ligand, sodium hydrotris(methimazolyl)borate with M(ClO4)2·6H2O [MMn(II), Ni(II), Cu(II) or Zn(II)] in methanol leads to the cleavage of B-N bond followed by the formation of complexes of the type [M(MeimzH)4](ClO4)2·H2O (1-4), where MeimzH=methimazole. All the complexes were fully characterized by spectro-analytical techniques. The molecular structure of the zinc(II) complex (4) was determined by X-ray crystallography, which supports the observed deboronation reaction in the scorpionate ligand with tetrahedral geometry around zinc(II) ion. The electronic spectra of complexes suggested tetrahedral geometry for manganese(II) and nickel(II) complexes, and square-planar geometry for copper(II) complex. Frontier molecular orbital analysis (HOMO-LUMO) was carried out by B3LYP/6-31G(d) to understand the charge transfer occurring in the molecules. All the complexes exhibit significant antimicrobial activity against Gram (-ve) and Gram (+ve) bacterial as well as fungal strains, which are quite comparable to standard drugs streptomycin and clotrimazole. The copper(II) complex (3) showed excellent free radical scavenging activity against DPPH in all concentration with IC50 value of 30μg/mL, when compared to the other complexes. In the molecular docking studies, all the complexes showed hydrophobic, π-π and hydrogen bonding interactions with BSA. The cytotoxic activity of the complexes against human hepatocellular liver carcinoma (HepG2) cells was assessed by MTT assay, which showed exponential responses toward increasing concentration of complexes. PMID:26735002

  13. NIR fluorescence spectroscopic investigations of Er{sup 3+}-ions doped borate based tellurium calcium zinc niobium oxide glasses

    Energy Technology Data Exchange (ETDEWEB)

    Ravi, O. [Department of Instrumentation, Sri Venkateswara University, Tirupati 517502 (India); Dhoble, S.J. [Department of Physics, RTM Nagpur University, Nagpur 440033 (India); Ramesh, B.; Devarajulu, G. [Department of Physics, Sri Venkateswara University, Tirupati 517502 (India); Reddy, C. Madhukar [Department of Physics, AP Model School, Yerravaripalem 517194 (India); Linganna, K. [Department of Physics, Sri Venkateswara University, Tirupati 517502 (India); Reddy, G. Rajasekhar [Department of Instrumentation, Sri Venkateswara University, Tirupati 517502 (India); Raju, B. Deva Prasad, E-mail: drdevaprasadraju@gmail.com [Department of Physics, Sri Venkateswara University, Tirupati 517502 (India); Department of Future Studies, Sri Venkateswara University, Tirupati 517502 (India)

    2015-08-15

    A series of Er{sup 3+} ions doped tellurium calcium zinc niobium borate glasses were prepared by the melt quenching technique. The prepared samples were investigated by optical absorption and near infrared fluorescence spectroscopic studies. The obtained Judd–Ofelt intensity parameters Ω{sub λ} (λ=2, 4 and 6) were determined through experimental and calculated oscillator strengths obtained from absorption spectra and their results are studied and compared with reported literature. The stark-level energies of {sup 4}I{sub 13/2} excited and {sup 4}I{sub 15/2} ground states were evaluated by using both the absorption and emission measurements. The effect of Er{sup 3+} ion concentration on the emission intensity of {sup 4}I{sub 13/2}→{sup 4}I{sub 15/2} transition was discussed. Intense and broad 1.53 µm infrared fluorescence is observed at 980 nm diode laser excitation. Photoluminescence (PL) and its decay behavior studies were carried out for the transition {sup 4}I{sub 13/2}→{sup 4}I{sub 15/2} at 1.53 µm emission. The broad emission together with higher values of the bandwidth (81 nm), stimulated emission cross-section (32.25×10{sup −22} cm{sup 2}) and lifetime (530 µs for 1.0 mol% of Er{sup 3+}) of level {sup 4}I{sub 13/2} make these glasses attractive for broadband amplifiers. From the analysis of spectroscopic data, the present glass is a prospective photonic material for practical applications in the visible and NIR region. - Highlights: • In this study we prepared TCZNB glasses doped with Er{sup 3+} ions. • Glasses are characterized with absorption, emission and lifetime analysis. • Judd–Ofelt theory is used to calculate radiative properties. • TCZNB glasses could be used as NIR lasers.

  14. Synthesis, structural and vibrational analysis of Li M B O3 ortho borates (M=Mg, Co, Zn)

    International Nuclear Information System (INIS)

    The structure of Li Zn B O3 obtained by low temperature hydrothermal reaction has been determined previously in single crystals. We calculated the crystallographic cell of the phases obtained by solid-state reaction without melting by indexing their X-ray powder diffraction patterns. We found evidence that the structure of Li Zn B O3 depends on the preparation method. The two structures found are monoclinic probably with the same Li-Zn cationic disorder, as evidence by vibrational behavior. The cell parameters for the phase prepared at high temperature are a = 7.9286(6), b = 5.0934(3), c 6.1464(5) A, β = 104.3(5)deg., Z = 4. The magnesium and cobalt compounds are isomorphous and form a total solid solution. Their monoclinic cells is not related to the cells of the zinc derivative. The parameters of the unit cell are a = 9.9155(8), b = 8.88847(11), c = 5.1577(4) A, β 91.231(8)deg., Z = 8 for the magnesium compound and a = 10.1100(7), b 8.8518(8), c = 5.1311(6) A, β = 91.358(7)deg., Z = 8 for the cobalt compound. The lithium cobalt borate is not very thermally stable and it is best synthesized by a two-step procedure. The effect of the lithium isotopic substitution on the vibrational frequencies shows that this cation is in tetrahedral coordination in all the phases. (authors). 6 refs., 3 figs., 5 tabs

  15. NIR fluorescence spectroscopic investigations of Er3+-ions doped borate based tellurium calcium zinc niobium oxide glasses

    International Nuclear Information System (INIS)

    A series of Er3+ ions doped tellurium calcium zinc niobium borate glasses were prepared by the melt quenching technique. The prepared samples were investigated by optical absorption and near infrared fluorescence spectroscopic studies. The obtained Judd–Ofelt intensity parameters Ωλ (λ=2, 4 and 6) were determined through experimental and calculated oscillator strengths obtained from absorption spectra and their results are studied and compared with reported literature. The stark-level energies of 4I13/2 excited and 4I15/2 ground states were evaluated by using both the absorption and emission measurements. The effect of Er3+ ion concentration on the emission intensity of 4I13/2→4I15/2 transition was discussed. Intense and broad 1.53 µm infrared fluorescence is observed at 980 nm diode laser excitation. Photoluminescence (PL) and its decay behavior studies were carried out for the transition 4I13/2→4I15/2 at 1.53 µm emission. The broad emission together with higher values of the bandwidth (81 nm), stimulated emission cross-section (32.25×10−22 cm2) and lifetime (530 µs for 1.0 mol% of Er3+) of level 4I13/2 make these glasses attractive for broadband amplifiers. From the analysis of spectroscopic data, the present glass is a prospective photonic material for practical applications in the visible and NIR region. - Highlights: • In this study we prepared TCZNB glasses doped with Er3+ ions. • Glasses are characterized with absorption, emission and lifetime analysis. • Judd–Ofelt theory is used to calculate radiative properties. • TCZNB glasses could be used as NIR lasers

  16. Visible red, NIR and Mid-IR emission studies of Ho3+ doped Zinc Alumino Bismuth Borate glasses

    Science.gov (United States)

    Mahamuda, Sk.; Swapna, K.; Packiyaraj, P.; Srinivasa Rao, A.; Vijaya Prakash, G.

    2013-12-01

    Zinc Alumino Bismuth Borate (ZnAlBiB) glasses doped with different concentrations of Holmium were prepared by conventional melt quenching technique. The glassy nature of these glasses has been confirmed through the XRD spectral measurements. The FTIR spectra recorded for undoped glass revealed the information related to the functional groups involved in the host glass. Optical absorption, excitation and photoluminescence spectra of these glasses have been recorded at room temperature. The Judd-Ofelt theory has been applied successfully to characterize the absorption spectra of the ZnAlBiB glasses. From this theory various radiative properties such as radiative transition probability (AR), radiative lifetimes (τR), branching ratios (βR) and spectroscopic quality factor (χ) for the prominent emission levels 5F5 → 5I7, 5F5 → 5I8 and 5I7 → 5I8 have been evaluated. The photoluminescence spectra revealed the quenching of luminescence intensity beyond 1.0 mol% of Ho3+ ion concentration in ZnAlBiB glasses. To investigate the lasing potentiality of 5F5 → 5I7, 5F5 → 5I8 and 5I7 → 5I8 transitions, the effective band width (Δλp) and the stimulated emission cross-section (σse) were determined. The CIE chromaticity co-ordinates were also evaluated from the emission spectra for all the glasses to understand the suitability of these materials for visible red laser emission in principle.

  17. Controllable fabrication of zinc borate hierarchical nanostructure on brucite surface for enhanced mechanical properties and flame retardant behaviors.

    Science.gov (United States)

    Wang, Xuesong; Pang, Hongchang; Chen, Wendan; Lin, Yuan; Zong, Lishuai; Ning, Guiling

    2014-05-28

    A novel and efficient halogen-free composite flame retardant (CFR) consisting of a brucite core and a fine zinc borate [Zn6O(OH)(BO3)3] hierarchical nanostructure shell was designed and synthesized via a facile nanoengineering route. It had been demonstrated that this unique hybrid structure possessed a high BET specific surface area (65 m(2)/g) and could significantly enhance the interfacial interaction when mixing with ethylene-vinyl acetate (EVA). This improved the transfer of stress between CFR particles and EVA matrix and increased the viscosity of EVA/EVA blends, which was beneficial for droplet inhibition and char forming. The mechanical properties and flammability behaviors of the EVA/CFR blends had been compared with the EVA/physical mixture (PM, with the given proportion of brucite and Zn6O(OH)(BO3)3). The mechanical properties of EVA/CFR blends, especially the tensile strength (TS), presented a remarkable increase reaching at least a 20% increment. Meanwhile, with the same 45 wt % of fillers, the EVA/CFR formulation could achieve a limiting oxygen index (LOI) value of 33 (37.5 % higher than that of EVA/PM blends) and UL-94 V-0 rating. Moreover, the heat release rate (HRR), peak heat release rate (PHRR), total heat released (THR), smoke production rate (SPR) and mass loss rate (MLR) were considerably reduced, especially PHRR and SPR for EVA/CFR blends were reduced to 32%. According to this study, the design of fine structure might pave the way for the future development of halogen-free flame retardants combining both enhanced mechanical properties and excellent flame retardant behaviors. PMID:24813539

  18. Synthesis of luminescent ethynyl-extended regioisomers of borate complexes based on 2-(2'-hydroxyphenyl)benzoxazole.

    Science.gov (United States)

    Massue, Julien; Frath, Denis; Retailleau, Pascal; Ulrich, Gilles; Ziessel, Raymond

    2013-04-22

    A series of thirteen luminescent tetrahedral borate complexes based on the 2-(2'-hydroxyphenyl)benzoxazole (HBO) core is presented. Their synthesis includes the incorporation of an ethynyl fragment by Sonogashira cross-coupling reaction, with the goal of extending the conjugation and consequently redshifting their emission wavelength. Different regioisomers, substituted in the 3-, 4-, or 5-position of the phenolate side of the HBO core, were studied in order to compare their photophysical properties. The complexes were characterized by X-ray diffraction and NMR, UV/Vis, and emission spectroscopy in solution and in the solid state. In all cases, complexation to boron leads to a donor-acceptor character that impacts their photophysical properties. Complexes with a 3- or 5-substituted fragment display mild to pronounced internal charge transfer (ICT), a feature strengthened by the presence of p-dibutylaminophenylacetylene in the molecular structure, protonation of the nitrogen atom of which leads to a significant blueshift and an increase in quantum yield. On the contrary, when the ethynyl module is grafted on the 4-position, narrow, structured, symmetrical absorption/emission bands are observed. Moreover, the fact that protonation has little effect on the emission maximum wavelength reveals singlet excited-state decay. Solid-state emission properties reveal a redshift compared to solution, explained by tight packing of the π-conjugated systems and the high planarity of the dyes. Subsequent connection of these complexes to other photoactive subunits (BODIPY, Boranil) provides dyads in which efficient cascade energy transfer is observed. PMID:23447429

  19. Investigation of a novel ternary electrolyte based on dimethyl sulfite and lithium difluoromono(oxalato)borate for lithium ion batteries

    Science.gov (United States)

    Chen, Renjie; Zhu, Lu; Wu, Feng; Li, Li; Zhang, Rong; Chen, Shi

    2014-01-01

    Lithium difluoromono(oxalato)borate (LiODFB) has been used as a novel lithium salt for battery in recent studies. In this study, a series of novel electrolytes has been prepared by adding 30 vol% dimethyl sulfite (DMS) or dimethyl carbonate (DMC) as co-solvent into an ethylene carbonate (EC)/ethyl methyl carbonate (EMC) + LiX mixture, in which the LiX could be LiClO4, LiODFB, LiBOB, LiTFSI, or LiCF3SO3. These ternary electrolytes have been investigated for use in lithium ion batteries. FT-IR spectroscopy analysis shows that characteristic functional groups (-CO3, -SO3) undergo red-shift or blue-shift with the addition of different lithium salts. The LiODFB-EC/EMC/DMS electrolyte exhibits high ionic conductivity, which is mainly because of the low melting point of DMS, and LiODFB possessing high solubility. The Li/MCMB cells containing this novel electrolyte exhibit high capacities, good cycling performance, and excellent rate performance. These performances are probably because both LiODFB and DMS can assist in the formation of SEI films by reductive decomposition. Additionally, the discharge capacity of Li/LiCoO2 half cell containing LiODFB-EC/EMC/DMS electrolyte is 130.9 mAh g-1 after 50 cycles, and it is very comparable with the standard-commercial electrolyte. The results show that this study produces a promising electrolyte candidate for lithium ion batteries.

  20. Synthesis, structure, and electronic structure calculation of a new centrosymmetric borate Pb2O[BO2(OH)] based on anion-centered OPb4 tetrahedra

    Science.gov (United States)

    Sun, Feng; Wang, Li; Stoumpos, Constantinos C.

    2016-08-01

    The synthesis, structure, and characterization of a new centrosymmetric borate Pb2O[BO2(OH)] based on anion-centered OPb4 tetrahedra are reported. Pb2O[BO2(OH)] crystallizes in monoclinic space group C2/m with a=12.725(7) Å, b=5.698(3) Å, c=7.344(4) Å, β=116.277(6)°. The electronic band structure and density of states of Pb2O[BO2(OH)] have been calculated via the density functional theory (DFT). Electron density difference calculation indicates that lone-pair electrons of Pb2+ cation should be stereoactive.

  1. The anisotropic Kerr nonlinear refractive index of the beta-barium borate (β-BaB2O4) nonlinear crystal

    DEFF Research Database (Denmark)

    Bache, Morten; Guo, Hairun; Zhou, Binbin;

    2013-01-01

    We study the anisotropic nature of the Kerr nonlinear response in a beta-barium borate (β-BaB2O4, BBO) nonlinear crystal. The focus is on determining the relevant χ(3) cubic tensor components that affect interaction of type I cascaded second-harmonic generation. Various experiments...... a complete list that we propose as reference of the four major cubic tensor components in BBO. We finally discuss the impact of using the cubic anisotropic response in ultrafast cascading experiments in BBO....

  2. The anisotropic Kerr nonlinear refractive index of the beta-barium borate (β-BaB2O4) nonlinear crystal

    OpenAIRE

    Bache, Morten; Guo, Hairun; Zhou, Binbin; Zeng, Xianglong

    2013-01-01

    We study the anisotropic nature of the Kerr nonlinear response in a beta-barium borate (β-BaB2O4, BBO) nonlinear crystal. The focus is on determining the relevant χ(3) cubic tensor components that affect interaction of type I cascaded second-harmonic generation. Various experiments in the literature are analyzed and we correct the data from some of the experiments for contributions from cascading as well as for updated material parameters. We also perform an additional experimental measuremen...

  3. Transition metal complexes of oxazolinylboranes and cyclopentadienyl-bis(oxazolinyl)borates: Catalysts for asymmetric olefin hydroamination and acceptorless alcohol decarbonylation

    Energy Technology Data Exchange (ETDEWEB)

    Manna, Kuntal [Ames Lab., Ames, IA (United States)

    2012-12-17

    The research presented and discussed in this dissertation involves the synthesis of transition metal complexes of oxazolinylboranes and cyclopentadienyl-bis(oxazolinyl)borates, and their application in catalytic enantioselective olefin hydroamination and acceptorless alcohol decarbonylation. Neutral oxazolinylboranes are excellent synthetic intermediates for preparing new borate ligands and also developing organometallic complexes. Achiral and optically active bis(oxazolinyl)phenylboranes are synthesized by reaction of 2-lithio-2-oxazolide and 0.50 equiv of dichlorophenylborane. These bis(oxazolinyl)phenylboranes are oligomeric species in solid state resulting from the coordination of an oxazoline to the boron center of another borane monomer. The treatment of chiral bis(oxazolinyl)phenylboranes with sodium cyclopentadienide provide optically active cyclopentadienyl-bis(oxazolinyl)borates H[PhB(C5H5)(OxR)2] [OxR = Ox4S-iPr,Me2, Ox4R-iPr,Me2, Ox4S-tBu]. These optically active proligands react with an equivalent of M(NMe2)4 (M = Ti, Zr, Hf) to afford corresponding cyclopentadienyl-bis(oxazolinyl)borato group 4 complexes {PhB(C5H4)(OxR)2}M(NMe2)2 in high yields. These group 4 compounds catalyze cyclization of aminoalkenes at room temperature or below, providing pyrrolidine, piperidine, and azepane with enantiomeric excesses up to 99%. Our mechanistic investigations suggest a non-insertive mechanism involving concerted C-N/C-H bond formation in the turnover limiting step of the catalytic cycle. Among cyclopentadienyl-bis(oxazolinyl)borato group 4 catalysts, the zirconium complex {PhB(C5H4)(Ox4S-iPr,Me2)2}Zr(NMe2)2 ({S-2}Zr(NMe2)2) displays highest activity and enantioselectivity. Interestingly, S-2

  4. Green-emitting nanoscaled borate phosphors Sr{sub 3}RE{sub 2}(BO{sub 3}){sub 4}:Tb{sup 3+}

    Energy Technology Data Exchange (ETDEWEB)

    Shyichuk, A.; Lis, S., E-mail: blis@amu.edu.pl

    2013-07-15

    Three Tb{sup 3+} doped mixed strontium – rare earths borate phosphors of general formula Sr{sub 3}RE{sub 2}(BO{sub 3}){sub 4}:Tb{sup 3+} (RE = Y, La or Gd) of 25–40 nm particle size were obtained by the Pechini sol–gel method, using citric acid and ethylene glycol as gel-forming agents. The structures of prepared materials were confirmed and characterized using X-ray powder diffraction and transmission electron microscopy. Photoluminescence properties, such as emission and excitation spectra and luminescence lifetimes of the phosphors, were measured. Excitation of the phosphors using different wavelengths in the UV range is possible. Lifetimes measured for the phosphors ranged from 2.2 to 2.7 ms. All of the Tb{sup 3+}-doped phosphors show excellent luminescent properties, with a bright emission of green light under UV excitation. The color coordinates of emitted light on CIE1931 chromaticity diagram are close to those of National Television Standards Committee (NTSC) standard of green. - Graphical abstract: Display Omitted - Highlights: • Mixed strontium-rare earths borate Tb{sup 3+}-doped nanoluminophors were obtained for the first time. • Optimal conditions for the synthesis of Sr{sub 3}RE{sub 2}(BO{sub 3}){sub 4}:Tb{sup 3+} were found. • Photoluminescence properties of well-emitting products are discussed. • The color CIE coordinates of the nanosized (40 nm) particles were determined.

  5. The effect of Cu-rich sub-layer on the increased corrosion resistance of Cu-xZn alloys in chloride containing borate buffer

    International Nuclear Information System (INIS)

    The electrochemical behaviour of Cu-xZn alloys, as well as their constituent metals, in a borate buffer containing chloride ions in the molar range from 0.01 to 1 M are studied. Characteristics of these materials under anodic polarization are compared and the composition and morphology of the corrosion products formed in the course of polarization experiment are analysed by SEM and EDS. X-ray photoelectron spectroscopy and electrochemical impedance measurements are used for characterization of the surface layers formed on Cu, Zn and Cu-40Zn alloy during 2-h immersion at E oc in a borate buffer containing two different concentrations of chloride ions. New aspects of the behaviour of brass under E oc condition are revealed. The improved corrosion resistance of brass in chloride media, if compared to zinc metal, is attributed to a Cu-rich layer formed by the selective dissolution of zinc. Based on the results, a structural model describing the improved corrosion resistance of Cu-40Zn alloy with respect to Zn metal is proposed

  6. Tris(triazolyl)borate ligands of intermediate steric bulk for the synthesis of biomimetic structures with hydrogen bonding and solubility in hydrophilic solvents.

    Science.gov (United States)

    Gardner, Sean R; Papish, Elizabeth T; Monillas, Wesley H; Yap, Glenn P A

    2008-12-01

    Tris(triazolyl)borate ligands (Ttz) of intermediate steric bulk were synthesized to investigate their potential for hydrogen bonding and improved solubility in hydrophilic solvents as applied to biomimetic chemistry. The crystal structure of 3-phenyl-5-methyl-1,2,4-triazole (Htz(Ph,Me)) revealed hydrogen bonding and pi stacking interactions. The new ligand salt, potassium tris(3-phenyl-5-methyl-1,2,4-triazolyl)borate (KTtz(Ph,Me)) was synthesized as the first example of a Ttz ligand of intermediate steric bulk. Metathesis between KTtz(Ph,Me) and NaCl followed by recrystallization produced [NaTtz(Ph,Me)].6CH3OH in which the geometry around the sodium is octahedral with an unusual N(3)O(3) donor set; this structure also shows that a hydrogen bonding network is formed by methanol molecules and triazole nitrogens. (Ttz(Ph,Me))ZnCl was synthesized and characterized crystallographically as [(Ttz(Ph,Me))ZnCl].0.5CH3OH in which the zinc is tetrahedral and the triazole rings are within hydrogen bonding distance of CH(3)OH. All of these new compounds are methanol soluble to varying degrees and Htz(Ph,Me) and KTtz(Ph,Me) are soluble in methanol/water mixtures. PMID:18848725

  7. Coordination and ion-ion interactions of chromium centers in alkaline earth zinc borate glasses probed by electron paramagnetic resonance and optical spectroscopy

    Science.gov (United States)

    Sumalatha, B.; Omkaram, I.; Rajavardana Rao, T.; Linga Raju, Ch

    2013-05-01

    Electron paramagnetic resonance (EPR), optical absorption and FT-IR studies have been carried out on chromium ions incorporated in alkaline earth zinc borate glasses. The EPR spectra exhibit two resonance signals with effective g values at g ≈ 1.99 and ≈1.97. The resonance signal at g ≈ 1.99 is attributed to the contribution from both the exchange coupled Cr3+-Cr3+ ion pairs and the isolated Cr3+ ions and the resonance signal at g ≈ 1.97 is due to Cr5+ ions. The paramagnetic susceptibility (χ) was calculated from the EPR data at various (123-303 K) temperatures and the Curie temperature (θp) was calculated from the 1/χ-T graph. The optical absorption spectra exhibit three bands at ˜360 nm, ˜440 nm and a broad band at ˜615 nm characteristic of Cr3+ ions in an octahedral symmetry. From the observed band positions, the crystal-field splitting parameter Dq and the Racah parameters (B and C) have been evaluated. From the ultraviolet edges, the optical band gap energies (Eopt) and Urbach energy (ΔE) are calculated. The theoretical optical basicity (Λth) of these glasses has also been evaluated. Chromium ions doped alkaline earth zinc borate glasses show BO3 and BO4 structural units in the FT-IR studies.

  8. Coordination and ion–ion interactions of chromium centers in alkaline earth zinc borate glasses probed by electron paramagnetic resonance and optical spectroscopy

    International Nuclear Information System (INIS)

    Electron paramagnetic resonance (EPR), optical absorption and FT-IR studies have been carried out on chromium ions incorporated in alkaline earth zinc borate glasses. The EPR spectra exhibit two resonance signals with effective g values at g ≈ 1.99 and ≈1.97. The resonance signal at g ≈ 1.99 is attributed to the contribution from both the exchange coupled Cr3+–Cr3+ ion pairs and the isolated Cr3+ ions and the resonance signal at g ≈ 1.97 is due to Cr5+ ions. The paramagnetic susceptibility (χ) was calculated from the EPR data at various (123–303 K) temperatures and the Curie temperature (θp) was calculated from the 1/χ–T graph. The optical absorption spectra exhibit three bands at ∼360 nm, ∼440 nm and a broad band at ∼615 nm characteristic of Cr3+ ions in an octahedral symmetry. From the observed band positions, the crystal-field splitting parameter Dq and the Racah parameters (B and C) have been evaluated. From the ultraviolet edges, the optical band gap energies (Eopt) and Urbach energy (ΔE) are calculated. The theoretical optical basicity (Λth) of these glasses has also been evaluated. Chromium ions doped alkaline earth zinc borate glasses show BO3 and BO4 structural units in the FT-IR studies. (paper)

  9. Halogen-free bis(imidazolium)/bis(ammonium)-di[bis(salicylato)borate] ionic liquids as energy-efficient and environmentally friendly lubricant additives.

    Science.gov (United States)

    Gusain, Rashi; Gupta, Piyush; Saran, Sandeep; Khatri, Om P

    2014-09-10

    Bis(imidazolium)- and bis(ammonium)-di[bis(salicylato)borate] ionic liquids with variable alkyl chain and cyclic ring structures, were synthesized and then evaluated them as potential lubricant additives. The copper strip test results revealed noncorrosive properties of these ionic liquids. Introduction of halogen content in bis(imidazolium) ionic liquid by replacement of bis(salicylato)borate (BScB) anion with hexafluorophosphate (PF6(-)), severely corroded the copper strip. Thermogravimetric results showed that bis(imidazolium) ionic liquids exhibited higher thermal stability than bis(ammonium) ionic liquids owing to compact structure provided by imidazolium rings, higher intermolecular interactions, smaller free volume and low steric hindrance. The lubrication properties of these ionic liquids as additives to synthetic lubricant poly(ethylene) glycol (PEG 200) were evaluated for steel balls. Results showed that bis(ammonium)- and bis(imidazolium)-(BScB)2 ionic liquids as additives significantly reduced both friction coefficient and wear of PEG 200. The structure of cations, particularly the variation in substituted alkyl chain length monitored the degree of reduction in friction and wear. The excellent lubrication properties were attributed to the formation of adsorbed tribo-thin film and tribochemical product during the tribo-contact. Being halogen-, phosphorus-, and sulfur-free, these ionic liquids (a) protects contact surfaces from tribo-corrosive events, (b) reduces the friction and wear, and (c) keep environment green and clean.

  10. Ferromagnetic resonance in a single crystal of iron borate and magnetic field tuning of hybrid oscillations in a composite structure with a dielectric: Experiment and theory

    International Nuclear Information System (INIS)

    The high-frequency properties of a composite resonator comprised single crystal iron borate (FeBO3), a canted antiferromagnet with a weak ferromagnetic moment, and a polycrystalline dielectric were investigated at 9–10 GHz. Ferromagnetic resonance in this frequency range was observed in FeBO3 for bias magnetic fields of ∼250 Oe. In the composite resonator, the magnetic mode in iron borate and dielectric mode are found to hybridize strongly. It is shown that the hybrid mode can be tuned with a static magnetic field. Our studies indicate that coupling between the magnetic mode and the dielectric resonance can be altered from maximum hybridization to a minimum by adjusting the position of resonator inside the waveguide. Magnetic field tuning of the resonance frequency by a maximum of 145 MHz and a change in the transmitted microwave power by as much as 16 dB have been observed for a bias field of 250 Oe. A model is discussed for the magnetic field tuning of the composite resonator and theoretical estimates are in reasonable agreement with the data. The composite resonator with a weak ferromagnet and a dielectric is of interest for application in frequency agile devices with electronically tunable electrodynamic characteristics for the mm and sub-mm wave bands

  11. Role of anions and reaction conditions in the preparation of uranium(VI), neptunium(VI), and plutonium(VI) borates.

    Science.gov (United States)

    Wang, Shuao; Villa, Eric M; Diwu, Juan; Alekseev, Evgeny V; Depmeier, Wulf; Albrecht-Schmitt, Thomas E

    2011-03-21

    U(VI), Np(VI), and Pu(VI) borates with the formula AnO(2)[B(8)O(11)(OH)(4)] (An = U, Np, Pu) have been prepared via the reactions of U(VI) nitrate, Np(VI) perchlorate, or Pu(IV) or Pu(VI) nitrate with molten boric acid. These compounds are all isotypic and consist of a linear actinyl(VI) cation, AnO(2)(2+), surrounded by BO(3) triangles and BO(4) tetrahedra to create an AnO(8) hexagonal bipyramidal environment. The actinyl bond lengths are consistent with actinide contraction across this series. The borate anions bridge between actinyl units to create sheets. Additional BO(3) triangles and BO(4) tetrahedra extend from the polyborate layers and connect these sheets together to form a three-dimensional chiral framework structure. UV-vis-NIR absorption and fluorescence spectroscopy confirms the hexavalent oxidation state in all three compounds. Bond-valence parameters are developed for Np(VI). PMID:21291194

  12. Ferromagnetic resonance in a single crystal of iron borate and magnetic field tuning of hybrid oscillations in a composite structure with a dielectric: Experiment and theory

    Science.gov (United States)

    Popov, M. A.; Zavislyak, I. V.; Chumak, H. L.; Strugatsky, M. B.; Yagupov, S. V.; Srinivasan, G.

    2015-07-01

    The high-frequency properties of a composite resonator comprised single crystal iron borate (FeBO3), a canted antiferromagnet with a weak ferromagnetic moment, and a polycrystalline dielectric were investigated at 9-10 GHz. Ferromagnetic resonance in this frequency range was observed in FeBO3 for bias magnetic fields of ˜250 Oe. In the composite resonator, the magnetic mode in iron borate and dielectric mode are found to hybridize strongly. It is shown that the hybrid mode can be tuned with a static magnetic field. Our studies indicate that coupling between the magnetic mode and the dielectric resonance can be altered from maximum hybridization to a minimum by adjusting the position of resonator inside the waveguide. Magnetic field tuning of the resonance frequency by a maximum of 145 MHz and a change in the transmitted microwave power by as much as 16 dB have been observed for a bias field of 250 Oe. A model is discussed for the magnetic field tuning of the composite resonator and theoretical estimates are in reasonable agreement with the data. The composite resonator with a weak ferromagnet and a dielectric is of interest for application in frequency agile devices with electronically tunable electrodynamic characteristics for the mm and sub-mm wave bands.

  13. Luminescence characterization of Eu{sup 3+} doped Zinc Alumino Bismuth Borate glasses for visible red emission applications

    Energy Technology Data Exchange (ETDEWEB)

    Swapna, K.; Mahamuda, Sk. [Department of Physics, K L University, Green Fields, Vaddeswaram, 522 502 Guntur District, Andhra Pradesh (India); Rao, A. Srinivasa, E-mail: drsrallam@gmail.com [Department of Physics, K L University, Green Fields, Vaddeswaram, 522 502 Guntur District, Andhra Pradesh (India); Department of Applied Physics, Delhi Technological University, Bawana Road, New Delhi 110 042 (India); Sasikala, T. [Department of Physics, SV University, Tirupathi 517 502, Andhra Pradesh (India); Packiyaraj, P. [Nanophotonics Laboratory, Department of Physics, Indian Institute of Technology-Delhi, Hauz Khaz, New Delhi 110 016 (India); Moorthy, L. Rama [Department of Physics, SV University, Tirupathi 517 502, Andhra Pradesh (India); Prakash, G. Vijaya [Nanophotonics Laboratory, Department of Physics, Indian Institute of Technology-Delhi, Hauz Khaz, New Delhi 110 016 (India)

    2014-12-15

    Zinc Alumino Bismuth Borate (ZnAlBiB) glasses doped with different concentrations of Eu{sup 3+} ions have been prepared by rapid melt quenching technique and characterized for their luminescence behavior through various spectroscopic techniques such as absorption, excitation, emission, decay profiles and confocal image measurements at room temperature. From the measured absorption spectra, the bonding parameters (δ) were evaluated to find the nature of bonding between Eu{sup 3+} ions with its surrounding ligands in these ZnAlBiB glasses. The emission spectra of Eu{sup 3+} ions in ZnAlBiB glasses excited at 410 nm (CW laser) show the characteristic of Eu{sup 3+} ions with more intense visible red emission corresponding to {sup 5}D{sub 0}→{sup 7}F{sub 2} transition. This intense visible red emission is further confirmed by the confocal luminescence images recorded for all the ZnAlBiB glasses. Judd–Ofelt (J–O) parameters estimated from the emission spectral information are used to estimate the important radiative properties such as transition probability (A{sub R}), branching ratios (β{sub R}) and emission-cross sections for the prominent emission levels. The large stimulated emission cross-sections and branching ratios observed for ZnAlBiB glasses suggest the utility of these glasses in visible red region of the electromagnetic spectrum. The CIE chromaticity coordinates evaluated from the emission spectra and the confocal images recorded for all the ZnAlBiB glasses also indicates that, these glasses at higher concentration of Eu{sup 3+} ions are aptly suitable for intense red emission at 613 nm corresponding to {sup 5}D{sub 0}→{sup 7}F{sub 2} transition. - Highlights: • ZnAlBiB glasses doped with Eu{sup 3+} ions were prepared by conventional melt quenching technique. • Radiative properties are measured from the emission spectra. • Quantum efficiency of the ZnAlBiB glasses is measured by using radiative and measured lifetimes. • CIE Chromaticity

  14. Structure-function correlations in Iron(II) tris(pyrazolyl)borate spin-state crossover complexes.

    Science.gov (United States)

    Reger, Daniel L; Gardinier, James R; Elgin, J Derek; Smith, Mark D; Hautot, Dimitri; Long, Gary J; Grandjean, Fernande

    2006-10-30

    Iron(II) poly(pyrazolyl)borate complexes have been investigated to determine the impact of substituent effects, intramolecular ligand distortions, and intermolecular supramolecular structures on the spin-state crossover (SCO) behavior. The molecular structure of Fe[HB(3,4,5-Me3pz)3]2 (pz = pyrazolyl ring), a complex known to remain high spin when the temperature is lowered, reveals that this complex has an intramolecular ring-twist distortion that is not observed in analogous complexes that do exhibit a SCO at low temperatures, thus indicating that this distortion greatly influences the properties of these complexes. The structure of Fe[B(3-(cy)Prpz)4]2.(CH3OH) ((cy)Pr = cyclopropyl ring) at 294 K has two independent molecules in the unit cell, both of which are high spin; only one of these high-spin iron(II) sites, the site with the lesser ring-twist distortion, is observed to be low-spin iron(II) in the 90 K structure. A careful evaluation of the supramolecular structures of these complexes and several similar complexes reported previously revealed no strong correlation between the supramolecular packing forces and their SCO behavior. Magnetic and Mössbauer spectral measurements on Fe[B(3-(cy)Prpz)4]2 and Fe[HB(3-(cy)Prpz)3]2 indicate that both complexes exhibit a partial SCO from fully high-spin iron(II) at higher temperatures, respectively, to a 50:50 high-spin/low-spin mixture of iron(II) below 100 K. These results may be understood, in the former case, by the differences in ring-twisting and, in the latter case, by a phase transition; in all complexes in which a phase transition is observed, this change dominates the SCO behavior. A comparison of the Mössbauer spectral properties of these two complexes and of Fe[HB(3-Mepz)3]2 with that of other complexes reveals correlations between the Mössbauer-effect isomer shift and the average Fe-N bond distance and between the quadrupole splitting and the average FeN-NB intraligand dihedral torsion angles and the

  15. Paramagnetic oxotungsten(V) complexes containing the hydrotris(3,5-dimethylpyrazol-1-yl)borate ligand.

    Science.gov (United States)

    Sproules, Stephen; Eagle, Aston A; Taylor, Michelle K; Gable, Robert W; White, Jonathan M; Young, Charles G

    2011-05-16

    Sky-blue Tp*WOCl(2) has been synthesized from the high-yielding reaction of Tp*WO(2)Cl with boron trichloride in refluxing toluene. Dark-red Tp*WOI(2) was prepared via thermal decarbonylation followed by aerial oxidation of Tp*WI(CO)(3) in acetonitrile. From these precursors, an extensive series of mononuclear tungstenyl complexes, Tp*WOXY [X = Cl(-), Y = OPh(-), SPh(-); X = Y = OPh(-), 2-(n-propyl)phenolate (PP(-)), SPh(-), SePh(-); XY = toluene-3,4-dithiolate (tdt(2-)), quinoxaline-2,3-dithiolate (qdt(2-)), benzene-1,2-diselenolate (bds(2-)); Tp* = hydrotris(3,5-dimethylpyrazol-1-yl)borate], was prepared by metathesis with the respective alkali-metal salt of X(-)/XY(2-) or (NHEt(3))(2)(qdt). The complexes were characterized by microanalysis, mass spectrometry, electrochemistry, IR, electron paramagnetic resonance (EPR), and electronic absorption spectroscopies, and X-ray crystallography (for X = Y = OPh(-), PP(-), SPh(-); XY = bds(2-)). The six-coordinate, distorted-octahedral tungsten centers are coordinated by terminal oxo [W≡O = 1.689(6)-1.704(3) Å], tridentate Tp*, and monodentate or bidentate O/S/Se-donor ligands. Spin Hamiltonian parameters derived from the simulation of fluid-solution X-band EPR spectra revealed that the soft-donor S/Se ligand complexes had larger g values and smaller (183)W hyperfine coupling constants than the less covalent hard-donor O/Cl species. The former showed low-energy ligand-to-metal charge-transfer bands in the near-IR region of their electronic absorption spectra. These oxotungsten(V) complexes display lower reduction potentials than their molybdenum counterparts, underscoring the preference of tungsten for higher oxidation states. Furthermore, the protonation of the pyrazine nitrogen atoms of the qdt(2-) ligand has been examined by spectroelectrochemistry; the product of the one-electron reduction of [Tp*WO(qdtH)](+) revealed usually intense low-energy bands. PMID:21495687

  16. Caveats for poly(methimazolyl)borate chemistry: the novel inorganic heterocycles [H2C(mt)2BR2]Cl (mt = methimazolyl; BR2 = BH2, BH(mt), 9-BBN).

    Science.gov (United States)

    Crossley, Ian R; Hill, Anthony F; Humphrey, Elizabeth R; Smith, Matthew K; Tshabang, Never; Willis, Anthony C

    2004-08-21

    Whilst frequently used for reactions of poly(methimazolyl)borates, dichloromethane is not an innocent solvent, but rather slowly forms heterocyclic salts [H(2)C(mt)(2)BR(2)]Cl, three examples of which (BR(2) = BH(2), BH(mt), 9-borabicyclononyl) have been structurally characterised to confirm the unprecedented B(NCS)(2)C connectivity. PMID:15306929

  17. Interaction of Ln(III) and An(III)/IV/V/VI) with borate in dilute to concentrated NaCl, CaCl2 and MgCl2 solutions

    OpenAIRE

    Hinz, Katja

    2015-01-01

    Die Wechselwirkung von Ln(III) und An(III,IV,V,VI) mit Borat wurde mit umfassenden Löslichkeitsexperimenten, Festphasencharakterisierung und spektroskopischen Studien in verdünnt bis konzentrierten NaCl-, CaCl2- und MgCl2-Lösungen untersucht.

  18. Effects of Borate Impregnation on the Color and Mechanical Properties of Heat-treated Rubber Wood%硼预处理对橡胶木热改性材颜色和力学性能的影响

    Institute of Scientific and Technical Information of China (English)

    李晓文; 李民; 秦韶山; 李家宁

    2011-01-01

    研究硼琢处理对橡胶木热改性材颜色和力学性能的影响。结果显示,1%浓度硼砂溶液预处理,对热改性材的颜色没有影响,当硼砂浓度增加到4%或8%时,木材材色有偏红的趋势。在185℃的热改性条件下,经硼预处理的热改性材的抗弯强度高于对照,在200℃条件下热改性后则无此规律。分析认为,硼预处理对热改性过程有一定影响,但并不是影响热改性材颜色和力学性能的主要因素。%The color and strength of heat-treated rubber wood which were impregnated by sodium borate were evaluated. Wood treated with 1% sodium borate solution showed no significant difference compared with control samples; when treated with 4% or 8% sodium borate solution, the color of wood turned red slightly. When the temperature of heat treatment was at 185℃, borate impregnation had a positive effect on wood strength, but when the temperature of heat treatment went as high as 200℃, the positive effect could not be observed. Borate impregnation affected the property of heat-treated wood, but it was not one of the fatal factors.

  19. Synthesis and crystal structure of the rhodium(I) cyclooctadiene complex with bis(3-tert-butylimidazol-2-ylidene)borate ligand

    International Nuclear Information System (INIS)

    The rhodium(I) cyclooctadiene complex with the bis(3-tert-butylimidazol-2-ylidene)borate ligand [H2B(ImtBu)2]Rh(COD) C22H36BN4Rh, has been prepared, and its crystal structure is determined by X-ray diffraction. Complex exhibits slightly distorted square planar configurations around the metal center, which is coordinated by the bidentate H2B(ImtBu)2 and one cyclooctadiene group. The Rh–Ccarbene bond lengths are 2.043(4) and 2.074(4) Å, and the bond angle C–Rh1–C is 82.59°. The dihedral angle between two imidazol-2-ylidene rings is 67.30°

  20. Nano-pit corrosion of the tabs in aluminum electrolytic capacitor: Polarization characteristics of the tabs in ethyleneglycol-borate solution with chloride ions

    Energy Technology Data Exchange (ETDEWEB)

    Xue Rong; Qian Yuanyuan; Liu Keke; Jiang Xiaoxing; Zhu Junjie [Key Lab of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093 (China); Zhang Jianrong [Key Lab of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093 (China)], E-mail: jrzhang@nju.edu.cn

    2008-10-15

    To evaluate the corrosion behavior of the anode tab in aluminum electrolytic capacitor, we performed some electrochemical and morphology analysis using the polarization curves in conjunction with atomic force microscope (AFM), scanning electronic microscope (SEM) and optical microscope (OM). The results suggest that the current oscillation was found to be associated with nano-pit, which is defined as the rectangular pit ({beta}) with a depth less than 55 nm and a width no more than 100 nm. Furthermore, elevation of Cl{sup -} concentration widened the crevices caused by electrolytic tension, enlarged the nano-pit area, and accelerated the electrochemical reaction rate of the anode tab in ethyleneglycol-borate solution. These findings may have implications for the failure of aluminum electrolytic capacitor.

  1. Effect of ZnSe and CdSe nanoparticles on the fluorescence and optical band gap of Sm3+ doped lead borate glasses

    Science.gov (United States)

    Fatokun, Stephen O.

    For the first part of this work, we prepared a series of Sm-doped lead borate (PbO-B2O3) glasses containing zinc selenide (ZnSe) and cadmium selenide (CdSe) nanoparticles (NPs) and studied the Sm 3+ fluorescence by varying the glass composition and size of the NPs. We have chosen these heavy metal oxide glasses to incorporate Sm3+ ions because they have large glass forming region, high refractive index, and good physical and thermal stability. Lead borate glasses with the following compositions xPbO:(96.5-x)B2O 3:0.5Sm2O3:3ZnSe/CdSe, x=36.5 and 56.5 mol%) are prepared using the melt-quenching method. Transmission electron microscopy characterization was done to confirm both nucleation and growth of the NPs for different annealing times. Fluorescence spectra of these samples are obtained with the excitation wavelengths at 403 and 477nm. Three fluorescence transitions are observed at 563 nm, 598 nm and 646 nm. The transition at 646 nm is a electric dipole (ED) transition that strongly depends on the covalency of the Sm-O bond and the asymmetry of the crystal field at the Sm3+ site. The 646 nm/598 nm fluorescence intensity ratio has been studied for different annealing times and PbO concentration for both ZnSe and CdSe samples. Longer annealing times tend to make the crystal field at the Sm3+ site more symmetric in nature for these glasses. The presence of CdSe NPs is seen to produce the greatest influence on the fluorescence intensity ratio. This is believed to be due to the larger size of the CdSe nanoparticles and its stronger influence on Sm3+ ions. The second part of this work was dedicated to the understanding of the optical band gap of samarium doped lead borate glasses with and without ZnSe/CdSe NPs. Optical absorption spectra for all these glass samples show their absorption edge in the ultraviolet region. Detailed analysis of the absorption edge was carried out using the Mott-Davis model and the optical band gap and the width of the tail in the band gap

  2. cis-Bis(2,2'-bipyridine-κN,N')bis-(dimethyl sulfoxide-κO)zinc bis-(tetra-phenyl-borate) dimethyl sulfoxide monosolvate.

    Science.gov (United States)

    Tomyn, Stefania; Gumienna-Kontecka, Elżbieta; Usenko, Natalia I; Iskenderov, Turganbay S; Prisyazhnaya, Elena V

    2011-12-01

    In the mononuclear title complex, [Zn(C(10)H(8)N(2))(2)(C(2)H(6)OS)(2)](C(24)H(20)B)(2)·C(2)H(6)OS, the Zn(II) ion is coordinated by four N atoms of two bidentate 2,2'-bipyridine mol-ecules and by the O atoms of two cis-disposed dimethyl sulfoxide mol-ecules in a distorted octa-hedral geometry. The S atom and the methyl groups of one of the coordinated dimethyl sulfoxide mol-ecules are disordered in a 0.509 (2):0.491 (2) ratio. The crystal packing is stabilized by C-H⋯O hydrogen bonds between the dimethyl sulfoxide solvent mol-ecules and tetra-phenyl-borate anions. PMID:22199567

  3. Effect of co-doped SnO{sub 2} nanoparticles on photoluminescence of cu-doped potassium lithium borate glass

    Energy Technology Data Exchange (ETDEWEB)

    Namma, Haydar Aboud; Wagiran, H.; Hussin, R.; Ariwahjoedi, B. [Department of Physics, Universiti Teknologi Malaysia, Skudai 81310, Malaysia and Baghdad College of Economic Sciences University (Iraq); Fundamental and Applied Sciences Department, Universiti Teknologi PETRONAS, 31750 Tronoh (Malaysia)

    2012-09-26

    The SnO{sub 2} co-doped lithium potassium borate glasses doped with 0.05, 0.10, 0.25 and 0.50 mol% of Cu were synthesized by the melt quenching technique. The SnO{sub 2} co-dope was added to the compounds in the amounts of 0.05, 0.10, and 0.20 mol%. The photoluminescent spectrum for different concentrations of copper was studied. It was observed that the intensity of blue emission (450, 490 nm) varies with concentration mol%. In addition, with different concentration of SnO{sub 2} to 0.10 mol% Cu, the influence of the luminescence has been observed to enhance intensity and shifted to blue and red (490, 535 nm) emissions.

  4. 新型锂盐--双乙二酸硼酸锂%A New Lithium Salt--Lithium Bis(oxalato)borate

    Institute of Scientific and Technical Information of China (English)

    余碧涛; 仇卫华; 李福燊

    2005-01-01

      介绍了新型锂盐--双乙二酸硼酸锂(LiBOB)的基本性质及其电解液在锂离子电池中的应用研究,并与现在常用的产业化锂盐LiPF6进行比较,总结了LiBOB的优缺点,指出了其进一步的研究方向。%  The reseaches of lithium bis(oxalato)borate (LiBOB) as a salt for lithium-ion batteries are summarized. Its physical and chemical properties and LiBOB-based electrolytes have been introduced in detail and compared with those of LiPF6. The advantages and disadvantages of LiBOB and its research emphases in future are also pointed out.

  5. Synthesis and crystal structure of the rhodium(I) cyclooctadiene complex with bis(3-tert-butylimidazol-2-ylidene)borate ligand

    Energy Technology Data Exchange (ETDEWEB)

    Chen, F.; Shao, K.-J.; Xiao, Y.-C.; Pu, X.-J.; Zhu, B., E-mail: zhubao-999@126.com [Affiliated Wuxi Peoples Hospital, Department of Nuclear Medicine, Nanjing Medical University (China); Jiang, M.-J., E-mail: jmj16888@126.com [Affiliated Wuxi Peoples Hospital, Department of Clinical Laboratory Science, Nanjing Medical University (China)

    2015-12-15

    The rhodium(I) cyclooctadiene complex with the bis(3-tert-butylimidazol-2-ylidene)borate ligand [H{sub 2}B(Im{sup t}Bu){sup 2}]Rh(COD) C{sup 22}H{sup 36}BN{sup 4}Rh, has been prepared, and its crystal structure is determined by X-ray diffraction. Complex exhibits slightly distorted square planar configurations around the metal center, which is coordinated by the bidentate H{sup 2}B(Im{sup t}Bu){sub 2} and one cyclooctadiene group. The Rh–C{sub carbene} bond lengths are 2.043(4) and 2.074(4) Å, and the bond angle C–Rh1–C is 82.59°. The dihedral angle between two imidazol-2-ylidene rings is 67.30°.

  6. RE2B8O15 (RE = La, Pr, Nd). Syntheses of three new rare earth borates isotypic to Ce2B8O15

    International Nuclear Information System (INIS)

    The rare earth borates RE2B8O15 (RE = La, Pr, Nd) were synthesized in a Walker-type multianvil apparatus under conditions of 5.5 GPa and 1100 C. Starting from the corresponding rare earth oxides and boron oxide, the syntheses yielded crystalline products of all new compounds that allowed crystal structure analyses based on single-crystal X-ray diffraction data for La2B8O15 and Nd2B8O15. The compound Pr2B8O15 could be characterized via X-ray powder diffractometry. The results show that the new compounds crystallize isotypically to Ce2B8O15 in the monoclinic space group P2/c. The infrared spectra of RE2B8O15 (RE = La, Pr, Nd) have also been studied.

  7. Study on borate glass system containing with Bi 2O 3 and BaO for gamma-rays shielding materials: Comparison with PbO

    Science.gov (United States)

    Kaewkhao, J.; Pokaipisit, A.; Limsuwan, P.

    2010-04-01

    In this work, the mass attenuation coefficients and shielding parameters of borate glass matrices containing with Bi 2O 3 and BaO have been investigated at 662 keV, and compare with PbO in same glass structure. The theoretical values were calculated by WinXCom software and compare with experiential data. The results found that the mass attenuation coefficients were increased with increasing of Bi 2O 3, BaO and PbO concentration, due to increase photoelectric absorption of all glass samples. However, Compton scattering gives dominant contribution to the total mass attenuation coefficients for studied glass samples. Moreover the half value layers (HVL) of glass samples were also better than ordinary concretes and commercial window glass. These results reflecting that the Bi-based glass can use replace Pb in radiation shielding glass. In the case of Ba, may be can use at appropriate energy such as X-rays or lower.

  8. Multi-beam second-harmonic generation in beta barium borate with a spatial light modulator and application to internal structuring in poly(methyl methacrylate)

    Science.gov (United States)

    Liu, D.; Perrie, W.; Kuang, Z.; Scully, P. J.; Baum, A.; Liang, S.; Edwardson, S. P.; Fearon, E.; Dearden, G.; Watkins, K. G.

    2012-06-01

    Parallel beam frequency doubling of 170 fs, NIR pulses is demonstrated by placing a thin beta barium borate (BBO) nonlinear crystal after a spatial light modulator. Computer-generated holograms applied to the spatial light modulator create 18 parallel diffracted beams at the fundamental wavelength λ=775 nm, then frequency doubled to λ=387 nm and focussed inside the poly(methyl methacrylate) (PMMA) substrate for refractive index structuring. This procedure, demonstrated for the first time in PMMA, requires careful attention to phase matching of multiple beams and opens up dynamic parallel processing at UV wavelengths where nematic liquid crystal devices are more sensitive to optical damage. By overlapping filamentary modifications, an efficient, stable volume phase grating with dimensions 5×5×2.0 mm3 and pitch Λ=15 μm was fabricated in 18 minutes and reached a first-order diffraction efficiency of 70 % at the Bragg angle.

  9. Photoluminescence properties of nanosized strontium-yttrium borate phosphor Sr3Y2(BO3)4:Eu3+ obtained by the sol-gel Pechini method

    Institute of Scientific and Technical Information of China (English)

    A.A. Shyichuk; S. Lis

    2011-01-01

    Mixed strontium-yttrium borate phosphor Sr3Y2(BO3)4 doped with Eu3+ ions was obtained by the sol-gel Pechini method.Crystal structure of the synthesized compound was analyzed by X-ray powder diffraction.Optimal conditions for the synthesis were found.Photophysical properties of the phosphor samples were investigated by collecting excitation and luminescence spectra as well as measuring luminescence lifetime.Judd-Ofelt analysis showed that Eu3+ ions occupied Y3+ sites in the crystalline network.The studied compound showed a red emission with the quantum yield of 54%-55% and can be potentially used as phosphor for plasma display panels and luminescent tubes.

  10. The pore size of non-graminaceous plant cell walls is rapidly decreased by borate ester cross-linking of the pectic polysaccharide rhamnogalacturonan II

    Energy Technology Data Exchange (ETDEWEB)

    Fleischer, A.; O' Neill, M.A.; Ehwald, R.

    1999-11-01

    The walls of suspension-cultured Chenopodium album L. cells grown continually for more than 1 year on B-deficient medium contained monomeric rhamnogalacturonan (mRG-II) but not the borate ester cross-linked RG II dimer (dRG-II-B). The walls of these cells had an increased size limit for dextran permeation, which is a measure of wall pore size. Adding boric acid to growing B-deficient cells resulted in B binding to the wall, the formation of dRG-II-B from mRG-II, and a reduction in wall pore size within 10 min. The wall pore size of denatured B-grown cells was increased by treatment at pH {le} 2.0 or by treatment with Ca{sup 2+}-chelating agents. The acid-mediated increase in wall pore size was prevented by boric acid alone at pH 2.0 and by boric acid together with Ca{sup 2+}, but not by Na{sup +} or Mg{sup 2+} ions at pH 1.5. The Ca{sup 2+}-chelator-mediated increase in pore size was partially reduced by boric acid. Their results suggest that B-mediated cross-linking of RG-II in the walls of living plant cells generates a pectin network with a decreased size exclusion limit for polymers. The formation, stability, and possible functions of a borate ester cross-linked pectic network in the primary walls of nongraminaceous plant cells are discussed.

  11. Generation of boron-deficiency-tolerant tomato by overexpressing an Arabidopsis thaliana borate transporter AtBOR1

    Directory of Open Access Journals (Sweden)

    Shimpei eUraguchi

    2014-04-01

    Full Text Available Nutrient deficiency in soil poses a widespread agricultural problem. Boron (B is an essential micronutrient in plants, and its deficiency causes defects in both vegetative and reproductive growth in various crops in the field. In Arabidopsis thaliana, increased expression of a major borate transporter gene AtBOR1 or boric acid channel gene AtNIP5;1 improves plant growth under B-deficient conditions. In this study, we examined whether high expression of a borate transporter gene increases B accumulation in shoots and improves the growth of tomato plant, a model of fruit-bearing crops, under B-deficient conditions. We established three independent transgenic tomato plants lines expressing AtBOR1 using Agrobacterium-mediated transformation of tomato (Solanum lycopersicum L. cv. Micro-Tom. Reverse transcription-polymerase chain reaction (RT-PCR analysis confirmed that two lines (Line 1 and Line 2 more strongly expressed AtBOR1 than Line 3. Wild-type plants and the transgenic plants were grown hydroponically under B-sufficient and B-deficient conditions. Wild-type and Line 3 (weakly expressing transgenic line showed a defect in shoot growth under B-deficient conditions, especially in the development of new leaves. However, seedlings of Line 1 and Line 2, the transgenic lines showing strong AtBOR1 expression, did not show the B-deficiency phenotype in newly developing leaves. In agreement with this phenotype, shoot biomass under low-B conditions was higher in the strongly expressing AtBOR1 line. B concentrations in leaves or fruits were also higher in Line 2 and Line 1. The present study demonstrates that strong expression of AtBOR1 improved growth in tomato under B-deficient conditions.

  12. Structural and mechanical properties of "peelable" organoaqueous dispersions with partially hydrolyzed poly(vinyl acetate)-borate networks: applications to cleaning painted surfaces.

    Science.gov (United States)

    Natali, Irene; Carretti, Emiliano; Angelova, Lora; Baglioni, Piero; Weiss, Richard G; Dei, Luigi

    2011-11-01

    The preparation and structural characterization of a family of viscoelastic dispersions of borate cross-linked, 80% hydrolyzed poly(vinyl acetate) (80PVAc) in aqueous-organic liquids are presented. Correlations between mechanical properties (from rheological measurements) and the degree and nature of cross-linking (from (11)B NMR spectroscopy) are reported, and the results are used to assess their potential as low-impact cleaning agents for the surfaces of paintings. Because the dispersions can be prepared at room temperature by simple procedures from readily available materials and can contain up to 50% (w/w) of an organic liquid, they offer important advantages over previously described cleaning agents that are based on fully hydrolyzed PVAc (i.e., poly(vinyl alcohol). The mechanical properties of the various aqueous-organic dispersions, as determined quantitatively by rheological investigations and qualitatively by their ease of removal from a solid surface (i.e., the so-called "peel-off" ability) have been tuned systematically by varying the amount of organic liquid, its structure, and the concentrations of borax and 80PVAc. The (11)B NMR studies demonstrate that the concentration of borate ions actively participating in cross-linking increases significantly with the amount of organic liquid in the mixture. The degree of cross-linking remains constant when the 80PVAc and borax concentrations are varied, as long as their ratios are kept constant. Some of the 80PVAc-borax dispersions have been tested successfully as cleaning agents on the surface of a 16th-17th century oil-on-wood painting by Lodovico Cardi, "Il Cigoli", that was covered by a brown patina and on the surface of a Renaissance wall painting by Vecchietta in Santa Maria della Scala, Siena, Italy, that had a degraded polyacrylate coating from a previous conservation treatment. PMID:21749078

  13. Verification of effectiveness of borated water shield for a cyclotron type self-shielded; Verificacao da eficacia da blindagem de agua borada construida para um acelerador ciclotron do tipo autoblindado

    Energy Technology Data Exchange (ETDEWEB)

    Videira, Heber S.; Burkhardt, Guilherme M.; Santos, Ronielly S., E-mail: heber@cyclopet.com.br [Cyclopet Radiofarmacos Ltda., Curitiba, PR (Brazil); Passaro, Bruno M.; Gonzalez, Julia A.; Santos, Josefina; Guimaraes, Maria I.C.C. [Universidade de Sao Paulo (HCFMRP/USP), Sao Paulo, SP (Brazil). Faculdade de Medicina. Hospital das Clinicas; Lenzi, Marcelo K. [Universidade Federal do Parana (UFPR), Curitina (Brazil). Programa de Pos-Graduacao em Engenharia Quimica

    2013-04-15

    The technological advances in positron emission tomography (PET) in conventional clinic imaging have led to a steady increase in the number of cyclotrons worldwide. Most of these cyclotrons are being used to produce {sup 18}F-FDG, either for themselves as for the distribution to other centers that have PET. For there to be safety in radiological facilities, the cyclotron intended for medical purposes can be classified in category I and category II, ie, self-shielded or non-shielded (bunker). Therefore, the aim of this work is to verify the effectiveness of borated water shield built for a cyclotron accelerator-type Self-shielded PETtrace 860. Mixtures of water borated occurred in accordance with the manufacturer’s specifications, as well as the results of the radiometric survey in the vicinity of the self-shielding of the cyclotron in the conditions established by the manufacturer showed that radiation levels were below the limits. (author)

  14. 磷酸三聚氰胺复配硼酸锌阻燃中密度纤维板的燃烧性能%Combustion Performance of Medium Density Fiberboard Treated with Melamine Phosphate and Zinc Borate

    Institute of Scientific and Technical Information of China (English)

    陈志林; 纪磊; 傅峰

    2011-01-01

    Melamine phosphate and zinc borate were selected as the main ingredients to develop a fire retardant for medium density fiberboard (MDF). A cone calorimeter was used to evaluate the combustion effects of MDF samples treated with the fire retardant. The results showed that melamine phosphate and zinc borate improved overall MDF fire retardant performance. By increasing zinc borate in the composition, MDF fire resistance and smoke suppression was improved.%选用磷酸三聚氰胺与硼酸锌复配,制备阻燃中密度纤维板(MDF),并采用锥形量热仪测试其燃烧性能,分析复配阻燃剂对板材燃烧性能的影响.结果表明:复配阻燃剂可有效提高MDF试材的阻燃抑烟性能,降低其热释放速率、总热释放量、产烟速率、总产烟量、CO及CO2生成速率,以磷酸三聚氰胺和硼酸锌等质量复配时,MDF试材的阻燃效果最优.

  15. Lithium Organic Borate Salt and Sulfite Functional Electrolytes%有机硼酸锂盐及亚硫酸酯类功能电解质材料

    Institute of Scientific and Technical Information of China (English)

    陈人杰; 何舟影; 吴锋

    2011-01-01

    随着锂离子电池对高安全性、高容量、高功率等性能的技术需求,新型功能电解质材料的研究开发成为锂离子电池新材料领域研发工作的重点.本文对面向锂离子电池应用的功能电解质材料锂盐和添加剂的最新研究进展作了较为全面的阐述,其中重点介绍了本研究团队近年来在面向改善锂离子电池安全性能、提高其温度适应性、增强电解质与电极材料相容特性等方面研究开发的系列基于双草酸硼酸锂[LiBOB]及二氟草酸硼酸锂[LiODFB]等有机硼酸锂盐和亚硫酸酯类等添加剂的新型功能电解质材料,其表现出高的热稳定性和良好的电化学性能.而且,其中的有机硼酸锂盐和亚硫酸酯还可以作为SEI成膜材料进行应用,其在石墨电极表面可形成稳定的SEI膜,有利于改善电池的循环寿命、自放电、库仑效率和不可逆容量衰减.最后,本文探讨了当前存在的问题及未来的研究方向,并对其应用前景进行了展望.%With the rapid development of lithium ion batteries with higher energy density, higher power density and high security, the research of new functional electrolytes has attracted considerable attention in novel materials field for lithium ion batteries.In this paper, the recent research advances of key technologies on the application of lithium salts and additive functional electrolytes in lithium ion batteries are reviewed, especially on the results of our research team focusing on new functional electrolytes based on lithium organic borate salt, such as lithium bis(oxalato) borate [LiBOB]and lithium oxalyldifluoroborate [LiODFB], and sulfite additives for the purpose of improving security, temperature adaptability and the compatibility between electrolytes and electrodes of lithium ion batteries.These electrolytes exhibit high thermal stability and good electrochemical properties.Moreover, lithium organic borate salt and sulfite have been

  16. Optical absorption and luminescence characteristics of Dy{sup 3+} doped Zinc Alumino Bismuth Borate glasses for lasing materials and white LEDs

    Energy Technology Data Exchange (ETDEWEB)

    Swapna, K.; Mahamuda, Sk. [Department of Physics, K.L. University, Green Fields, Vaddeswaram 522502, A.P. (India); Srinivasa Rao, A., E-mail: drsrallam@yahoo.co.in [Department of Physics, K.L. University, Green Fields, Vaddeswaram 522502, A.P. (India); Department of Applied Physics, Delhi Technological University, Delhi 110042 (India); Jayasimhadri, M. [Department of Applied Physics, Delhi Technological University, Delhi 110042 (India); Sasikala, T.; Rama Moorthy, L. [Department of Physics, S.V. University, Tirupathi 517502, A.P. (India)

    2013-07-15

    Good optical quality Dy{sup 3+} doped Zinc Alumino Bismuth Borate (ZnAlBiB) glasses were prepared by the conventional melt quenching technique and characterized by optical absorption and luminescence studies. The glassy nature of these materials has been confirmed through XRD measurements. From the absorption spectra, the three phenomenological JO parameters Ω{sub λ} (λ=2,4 and 6) have been determined from the absorption spectral intensities by using the JO theory. Luminescence spectra were measured for different concentrations of Dy{sup 3+} ions doped glasses by exciting the glasses at 387 nm. The intensity of Dy{sup 3+} emission spectra increases from 0.5 mol% to 1 mol % and beyond 1 mol % the concentration quenching is observed. The suitable concentration of Dy{sup 3+} ions for ZnAlBiB glassy material to act as good lasing material has been discussed by measuring the branching ratios and emission cross-sections for two strong emission transitions such as {sup 4}F{sub 9/2}→{sup 6}H{sub 15/2} and {sup 4}F{sub 9/2}→{sup 6}H{sub 13/2} observed in visible region. By exciting these glassy materials at various excitation wavelengths in n-UV region, the CIE chromaticity coordinates were evaluated for the two sharp emissions observed in blue ({sup 4}F{sub 9/2}→{sup 6}H{sub 15/2}) and yellow ({sup 4}F{sub 9/2}→{sup 6}H{sub 13/2}) regions to understand the suitability of these materials for white light generation. -- Highlights: ► Successfully synthesized the transparent Zinc Alumino Bismuth Borate glasses. ► Measured the absorption and luminescence properties. ► Discussed the spectroscopic properties by using Judd–Ofelt analysis for ZnAlBiB glasses. ► Finally, suitability of these glasses for lasers and white LEDs has been discussed.

  17. Liquid phase sintering of 20Bi(Zn0.5Ti0.5)O 3-80BaTiO3 dielectrics with bismuth-zinc-borate and bismuth borosilicate glasses

    Science.gov (United States)

    Shahin, David I.

    Dielectrics in the Bi(Zn0.5Ti0.5)O3-BaTiO 3 system (specifically 20BZT-80BT, in mol%) are promising candidates for high energy density capacitor applications due to broad temperature-dependent dielectric constant maxima and a relatively field-independent permittivity. Bulk samples require sintering temperatures of greater than 1180°C to reach useful densities. Due to incompatibility of Bi with low-pO2 processing, BZT-BT-based multilayer capacitors must utilize noble metal electrodes that resist oxidation during sintering. Sintering temperatures must be reduced to allow use of less expensive electrode materials (Cu, etc.). This work studies the reduced temperature sintering behavior and dielectric properties of BZT-BT sintered with 30Bi2O3-30ZnO-40B 2O3 and 50Bi2O3-25B2O 3-25SiO2 (mol%) liquid phase formers. Dielectrics sintered with 1v% borate additions and 5v% additions of either the borate or borosilicate achieved relative densities greater than 95% after sintering at 1000°C for four hours. All compositions retained the relaxor behavior exhibited by pure 20BZT-80BT. Increased borate additions led to greater dielectric constant reductions, while increased borosilicate additions yielded no clear trend in the dielectric constant reduction. Energy densities were estimated between 0.3-0.5 J/cm3; smaller glass additions typically led to larger energy densities. Dielectrics sintered with 1v% borate additions are of interest due to their high relative densities (approx. 96%) and energy densities of approximately 0.5 J/cm3 under 100kV/cm electric fields. Studies of BZT-BT/glass interfaces revealed the formation of crystalline interfacial layers less than 10 microns thick. The borate formed a bismuth titanate phase (likely Bi4Ti3O12) during heating to 700°C, whereas the borosilicate formed a barium silicate phase (likely BaSiO3) during processing to 800°C. Similar phases are expected to be present in the liquid phase sintered dielectrics and likely affect the BZT

  18. Intracellular signalling pathways in the vasoconstrictor response of mouse afferent arterioles to adenosine

    DEFF Research Database (Denmark)

    Hansen, Pernille B. Lærkegaard; Friis, Ulla Glenert; Uhrenholt, Torben Rene;

    2007-01-01

    calcium from the sarcoplasmic reticulum (SR), stimulated presumably by IP(3), is involved in the adenosine contraction mechanism of the afferent arteriole. In agreement with this notion is the observation that 2 aminoethoxydiphenyl borate (100 microM) blocked the adenosine-induced constriction whereas the...... protein kinase C inhibitor calphostin C had no effect. The calcium-activated chloride channel inhibitor IAA-94 (30 microM) inhibited the adenosine-mediated constriction. Patch clamp experiments showed that adenosine treatment induced a depolarizing current in preglomerular smooth muscle cells which was....... METHODS AND RESULTS: Adenosine (10(-7) M) significantly increased the intracellular calcium concentration in mouse isolated afferent arterioles measured by fura-2 fluorescence. Pre-treatment with thapsigargin (2 microM) blocked the vasoconstrictor action of adenosine (10(-7) M) indicating that release of...

  19. Complex actions of ionomycin in cultured cerebellar astrocytes affecting both calcium-induced calcium release and store-operated calcium entry

    DEFF Research Database (Denmark)

    Müller, Margit S; Obel, Linea Lykke Frimodt; Waagepetersen, Helle S;

    2013-01-01

    The polyether antibiotic ionomycin is a common research tool employed to raise cytosolic Ca(2+) in almost any cell type. Although initially thought to directly cause physicochemical translocation of extracellular Ca(2+) into the cytosol, a number of studies have demonstrated that the mechanism of......(2+), consisting of an initial peak and a subsequent sustained plateau. The response was dependent on concentration and exposure time. While the plateau phase was abolished in the absence of extracellular Ca(2+), the peak phase persisted. The peak amplitude could be lowered significantly...... by application of dantrolene, demonstrating involvement of Ca(2+)-induced Ca(2+)-release (CICR). The plateau phase was markedly reduced when store-operated Ca(2+)-entry (SOCE) was blocked with 2-aminoethoxydiphenyl borate. Our results show that ionomycin directly affects internal Ca(2+) stores in astrocytes...

  20. Be2BO3F: A Phase of Beryllium Fluoride Borate Derived from KBe2BO3F2 with Short UV Absorption Edge.

    Science.gov (United States)

    Guo, Shu; Liu, Lijuan; Xia, Mingjun; Kang, Lei; Huang, Qian; Li, Chao; Wang, Xiaoyang; Lin, Zheshuai; Chen, Chuangtian

    2016-07-01

    A phase of beryllium fluoride borate Be2BO3F (BBF) was successfully developed and grown by spontaneous nucleation from high temperature solution. The crystal belongs to the trigonal space group of R3̅c (No. 167), with lattice parameters a = 4.442(1) Å, c = 24.956(5) Å, and Z = 2. It is constructed by the infinite planar [Be2BO3F2]∞ layers, in which the planar triangle [BO3](3-) and the tetrahedral [BeO3F](5-) anionic groups are arranged in parallel via corner-sharing O atoms in each ab plane. BBF is an incongruent compound and decomposes at about 650 °C. The deep-ultraviolet (DUV) transmittance spectrum reveals that its UV cutoff wavelength is down to ∼150 nm. Theoretical calculations show that BBF has a large birefringence (Δn = 0.13 at 200 nm), which mainly originates from the infinite planar [Be2BO3F2]∞ layers. In conclusion, BBF may be served as a potential DUV birefringent material. PMID:27332696

  1. PERFORMANCE OF ZINC BORATE-TREATED ORIENTED STRUCTURAL STRAW BOARD AGAINST MOLD FUNGI, DECAY FUNGI, AND TERMITES – A PRELIMINARY TRIAL

    Directory of Open Access Journals (Sweden)

    Guangping Han,

    2012-05-01

    Full Text Available The performance of zinc borate (ZB-treated oriented structural straw board (OSSB against mold fungi, decay fungi, and termites was examined in standard laboratory evaluations. OSSB was fabricated with split wheat straw strands and diphenylmethane diisocyante (pMDI resin. The ZB was added during panel manufacture to achieve preservative levels (wt.% of 1.0%, 1.5%, 2.0%, and 3.0%. It was observed that after a four-week exposure to mold fungi all samples had some mold coverage, but the coverage on the ZB-treated samples was significantly lighter compared to the untreated OSSB. Decay test showed that the weight losses of ZB-treated OSSB blocks at 1.0% and 1.5% levels were significantly reduced compared to the untreated OSSB and solid wood controls, indicating superior performance of ZB-treated OSSB against decay fungi. The termite mortality indicated that none of the termites were alive at the conclusion of the test for ZB-treated OSSB. The results from these specific laboratory studies demonstrated that ZB retentions of 1.5% and greater provide performance against decay fungi and termites for OSSB panels. In addition, untreated OSSB has high susceptibility to mold due to the chemical features of wheat straw and incomplete removal of kernels.

  2. Lithium difluoro(oxalate)borate and LiBF4 blend salts electrolyte for LiNi0.5Mn1.5O4 cathode material

    Science.gov (United States)

    Zhou, Hongming; Xiao, Kaiwen; Li, Jian

    2016-01-01

    The electrochemical behaviors of lithium difluoro(oxalate)borate (LiODFB) and LiBF4 blend salts in ethylene carbonate + dimethyl carbonate + ethyl(methyl) carbonate (EC + DMC + EMC, 1:1:1, by wt.) have been investigated for LiNi0.5Mn1.5O4 cathode in lithium-ion batteries. The electric conductivity tests are utilized to examine the relationship among solution conductivity, the electrolyte composition and temperature. Through cyclic voltammetry, charge-discharge test and AC impedance measurements, we compare the capacity and cycling efficiency of LNMO cathode in different electrolyte systems at different temperatures and discharge current rates. Scanning electron microscopy (SEM) analysis and X-ray photoelectron spectroscopy (XPS) are served to analyze the surface nature of LNMO cathode after cycles at elevated temperature. These results demonstrate that LNMO cathode can exert excellent electrochemical performance with the increase of LiODFB concentration at room temperature and elevated temperature and it is found that just slight LiBF4, mixed with LiODFB as blend salts, can strikingly improve the cyclability at -20 °C, especially in high-rate cycling. Grouped together, the optimum LiODFB/LiBF4 molar ratio is around 4:1, which can present an excellent affinity to LNMO cathode in a wide electrochemical window.

  3. The Kinetics of Anodic Dissolution and Repassivation on 316L Stainless Steel in Borate Buffer Solution Studied by Abrading Electrode Technique

    Energy Technology Data Exchange (ETDEWEB)

    Xu, H. S.; Sun, D. B.; Yu, H. Y.; Meng, H. M. [University of Science and Technology Beijing, Beijing (China)

    2015-12-15

    The capacity of passive metal to repassivate after film damage determines the development of local corrosion and the resistance to corrosion failures. In this work, the repassivation kinetics of 316L stainless steel (316L SS) was investigated in borate buffer solution (pH 9.1) using a novel abrading electrode technique. The repassivation kinetics was analyzed in terms of the current density flowing from freshly bare 316L SS surface as measured by a potentiostatic method. During the early phase of decay (t < 2 s), according to the Avrami kinetics-based film growth model, the transient current was separated into anodic dissolution (i{sub diss}) and film formation (i{sub film}) components and analyzed individually. The film reformation rate and thickness were compared according to applied potential. Anodic dissolution initially dominated the repassivation for a short time, and the amount of dissolution increased with increasing applied potential in the passive region. Film growth at higher potentials occurred more rapidly compared to at lower potentials. Increasing the applied potential from 0 V{sub SCE} to 0.8 V{sub SCE} resulted in a thicker passive film (0.12 to 0.52 nm). If the oxide monolayer covered the entire bare surface (θ=1), the electric field strength through the thin passive film reached 1.6 x 10{sup 7} V/cm.

  4. Gd{sub 4}(BO{sub 2})O{sub 5}F. A gadolinium borate fluoride oxide comprising a linear BO{sub 2} moiety

    Energy Technology Data Exchange (ETDEWEB)

    Hoeppe, Henning A. [Augsburg Univ. (Germany). Inst. fuer Physik

    2015-07-01

    Gadolinium borate fluoride oxide Gd{sub 4}(BO{sub 2})O{sub 5}F crystallises in space group Pmmm (No. 59, a = 1574.6(4), b = 381.42(7), c = 660.88(11) pm, 565 refl., 28 parameters, R{sub 1} = 0.039, wR{sub 2} = 0.128, twin refinement) and comprises linear BO{sub 2}{sup -} anions between closely packed [GdO] layers formed by OGd{sub 4} tetrahedra and terminated by oxygen and fluorine atoms. The crystal structure's relationship with the NiAs type is illustrated. The Raman spectrum recorded on a single crystal of Gd{sub 4}(BO{sub 2})O{sub 5}F comprises a single peak at 1364 cm{sup -1} assigned to the only Raman-active vibrational mode ν{sub s} of the linear triatomic O-B-O units besides very weak peaks at 805 and 2084 cm{sup -1} (presumably the respective δ and ν{sub as} modes).

  5. Elastic properties and structural studies on some zinc-borate glasses derived from ultrasonic, FT-IR and X-ray techniques

    International Nuclear Information System (INIS)

    Glasses in the system (1 - x) [29Na2O- 4Al2O3- 67B2O3]- xZnO (0 ≤ x ≤ 35 mol%), have been prepared by the melt quenching technique. Elastic properties, X-ray and FT-IR spectroscopic studies have been employed to study the role of ZnO on the structure of the investigated glass system. Elastic properties and Debye temperature have been investigated using sound wave velocity measurements at 4 MHz at room temperature. The results showed that the density increases and the molar volume decreases while both sound velocities and the determined glass transition temperatures decrease with increase in x. X-ray and infrared spectra of the glasses reveal that the borate network consists of diborate units and is affected by the increase in the concentration of ZnO content. These results are interpreted in terms of the decrease in the N4 values (fraction of tetrahedral coordinated boron atoms), and substitution of longer bond lengths of Zn-O in place of shorter B-O bond. The results indicate that Zinc ions have been substituted for boron ions as tetrahedral network former ions. The elastic moduli are observed to increase with the increase of ZnO content.

  6. Low temperature lithium borate fusion's and the dissolution of sphalerite and stibnite - keeping the volatiles in the melt and the Pt/Au ware from destruction

    International Nuclear Information System (INIS)

    Full text: To achieve accuracy and precision better than 1% relative, analytical chemists in the mineral processing industry use lithium borate fusion - XRF spectrometry. For geological materials, cements, mineral sands, iron ores, this relatively quick and easy procedure is the procedure of choice. In recent times chemists have sort to fuse more difficult materials such as plant materials, coals, metallic powders, plastics and sulphides. Pressed powder pellets for sulphides in particular, are difficult to make and XRF data is poor. In these cases, pre-oxidation with nitrates followed by low temperature fusion usually works. In this presentation the fusion of sphalerite (ZnS) and stibnite (Sb2S3) concentrates are look at. These sulphides are the feed stock for preparing the oxides, ZnO and Sb2O3, which are mainly used in paints and plastics industry. Sb2O3 is also used as a flame inhibitor. Using the diagnostic tools of both visual inspection and X-ray diffraction, problems in preparing good quality fused beads and thus achieving the accuracy and precision required, will be investigated. Statistical data is presented on the fusion-XRF work done to date. Copyright (1999) Australian X-ray Analytical Association Inc

  7. An acentric calcium borate Ca2[B5O9]·(OH)·H2O: synthesis, structure, and nonliner optical property.

    Science.gov (United States)

    Wei, Qi; Cheng, Jian-Wen; He, Chao; Yang, Guo-Yu

    2014-11-01

    A novel noncentrosymmetric calcium borate, Ca2[B5O9]·(OH)·H2O (1), was synthesized under solvothermal condition using mixed solvents of pyridine and H2O. Compound 1 crystallizes in the monoclinic space group Cc. Its structure contains [B5O12] units and features a three-dimensional (3D) pcu net with nine-membered ring (9-MR) channels along the b-axis, where the Ca(2+) cations, OH(-) ions, and H2O molecules are located. Each Ca polyhedron shares three edges and one vertex with four neighbors to form a 3D dia Ca-O network. The pcu B-O net and dia Ca-O net are further interpenetrated to give the final denser net. The second harmonic generation (SHG) measurement shows that compound 1 is a type I phase-matchable material with a strong SHG response of ∼3 times that of KH2PO4. In addition, it exhibits a wide transparency range with a short UV cutoff edge below 200 nm. These results reveal that the compound is a potential deep-UV nonlinear optical material. The Vienna ab initio theoretical studies indicate the good SHG response is derived from the synergistic effect of the π-conjugated systems of BO3 groups and distorted CaO9 polyhedra. PMID:25317482

  8. Enthalpies of formation of CaAl4O7 and CaAl12O19 (hibonite) by high temperature, alkali borate solution calorimetry

    Science.gov (United States)

    Geiger, C. A.; Kleppa, O. J.; Grossman, L.; Mysen, B. O.; Lattimer, J. M.

    1988-01-01

    Enthalpies of formation were determined for two calcium aluminate phases, CaAl4O7 and CaAl12O19, using high-temperature alkali borate solution calorimetry. The aluminates were synthesized by multiple-cycle heating and grinding stoichiometric mixtures of CaCO3 and Al2O3, and the products were characteized by X-ray diffraction and SEM microbeam analysis. The data on impurities (CaAl4O7 was found to be about 89.00 percent pure by weight and the CaAl12O19 samples about 91.48 percent pure) were used to correct the heat of solution values of the synthetic products. The enthalpies of formation, at 1063 K, from oxides, were found to be equal to -(25.6 + or - 4.7) kJ/g.f.w. for CaAl4O7 and -(33.0 + or - 9.7) kJ/g.f.w. for CaAl12O19; the respective standard enthalpies of formation from elements, at 298 K, were estimated to be -4007 + or - 5.2 kJ/g.f.w. and -10,722 + or - 12 kJ/g.f.w.

  9. New inorganic (an)ion exchangers with a higher affinity for arsenate and a competitive removal capacity towards fluoride, bromate, bromide, selenate, selenite, arsenite and borate

    KAUST Repository

    Chubar, Natalia

    2011-12-01

    Highly selective materials and effective technologies are needed to meet the increasingly stronger drinking water standards for targeted ionic species. Inorganic ion exchangers based on individual and mixed-metal hydrous oxides (or mixed adsorbents that contain inorganic ion exchangers in their composition) are adsorptive materials that are capable of lowering the concentrations of anionic contaminants, such as H 2AsO 4 -, H 3AsO 3, F -, Br -, BrO 3 -, HSeO 4 -, HSeO 3 - and H 3BO 3, to 10 μg/L or less. To achieve a higher selectivity towards arsenate, a new ion exchanger based on Mg-Al hydrous oxides was developed by a novel, cost-effective and environmentally friendly synthesis method via a non-traditional (alkoxide-free) sol-gel approach. The exceptional adsorptive capacity of the Mg-Al hydrous oxides towards H 2AsO 4 - (up to 200 mg[As]/gdw) is due to the high affinity of this sorbent towards arsenate (steep equilibrium isotherms) and its fast adsorption kinetics. Because of the mesoporous (as determined by N 2 adsorption and SEM) and layered (as determined by XRD and FTIR) structure of the ion-exchange material as well as the abundance of anion exchange sites (as determined by XPS and potentiometric titration) on its surface the material demonstrated very competitive (or very high) removal capacity towards other targeted anions, including fluoride, bromide, bromate, selenate, selenite, and borate. © 2011 IWA Publishing.

  10. Synthesis, Characterization and Antimicrobial Activity of Potassium Hydro(benzoyl)(phthalyl)borate and Its Cobalt(Ⅱ), Nickel(Ⅱ), and Copper(Ⅱ) Complexes

    Institute of Scientific and Technical Information of China (English)

    SHARMA, Guruaribam, Shashikumar; SHEIKH, Rayees, Ahmad; SHREAZ, Sheikh; HASHMI, Athar, Adil; KHAN, Luqrnan, Ahmad

    2009-01-01

    A new organoborate ligand, hydro(benzoyl)(phthalyl)borate has been synthesized as its potassium salt (KL) and M=Cu(Ⅱ)]. All compounds were characterized by elemental analysis, DTIR, 1H NMR, ESI MS, UV-Vis techniques, conductivity and magnetic data measurements. Spectroscopic results suggest a square planar geometry in the Cu(Ⅱ) complex, while the Co(Ⅱ) and Ni(Ⅱ) complexes possess an octahedral geometry. Antibacterial activities (in vitro) of the ligand and its metal complexes were studied against two Gram positive (B. subtillis and B. magterium) and two Gram negative bacteria (E. Coli and S. boydi) at a single concentration (75 μg/mL) by using the Disc diffusion method. Antifungal activities (in vitro) were also checked for the compounds by using the same method against Candida albicans 10261, Penicillium sp. and Asperjillius niger., at a single concentration (50 μg/mL). The results showed that all the metal complexes, specially the nickel(Ⅱ) complex, have higher antibacterial and antifungal ac- tivities than the corresponding potassium salt.

  11. 硼酸三甲酯无“三废”合成工艺%Synthesis Process of Trimethyl borate

    Institute of Scientific and Technical Information of China (English)

    刘道明; 周章凯; 杨成

    2011-01-01

    以硼酸、甲醇为原料,用甲酰胺对产物进行萃取提纯,合成硼酸三甲酯,探索了最佳工艺条件。利用气相色谱、色谱-质谱联用、红外光谱等分析表征手段,鉴定反应产物,最佳工艺条件:n硼酸:n甲醇=1∶3.5;回流时间为4 h。此工艺无"三废"排放,有利于工业化生产。%Trimethyl borate was synthesized as raw material with boric acid and methly alcohol and formamide as extrac-tive,and the optimum condition was chosen by experiments.By means of gas chromatography,mass spectrometry and IR spectrum,the product was confirmed.The optimum conditions were that n(acid)∶n(alcohol)=1∶3.5 for 4 h This craft which has no"three wastes"the emissions is advantageous in the industrialization production.

  12. Tri(ethylene glycol)-substituted trimethylsilane/lithium bis(oxalate)borate electrolyte for LiMn2O4/graphite system

    Science.gov (United States)

    Kusachi, Yuki; Dong, Jian; Zhang, Zhengcheng; Amine, Khalil

    2011-10-01

    Silane-based electrolyte is a promising candidate for safer electrochemical energy storage devices because it is thermally and electrochemical stable, less flammable and environmental benign. In this paper, electrochemical properties of one of the silane-based electrolytes, tri(ethylene glycol)-substituted trimethylsilane (1NM3)-lithium bis(oxalate)borate (LiBOB) was studied using LiMn2O4 as cathode and MAG graphite as anode. When combined with LiBOB as lithium salt, the 1NM3-LiBOB electrolyte can provide solid electrolyte interface (SEI) formation due to the reductive decomposition of LiBOB at first charging cycle. Compared to the electrolyte used in the conventional lithium-ion batteries, 1NM3-LiBOB electrolyte showed compatible battery performance in LiMn2O4/MAG chemistry. The AC impedance measurement indicates that the activation energy (Ea) obtained from the charge transfer impedance for 1NM3-LiBOB was higher than that of the state-of-the-art electrolyte. Due to its low conductivity, the rate capability of 1NM3-LiBOB electrolyte needs to be improved.

  13. High-pressure syntheses and characterization of the rare-earth fluoride borates RE{sub 2}(BO{sub 3})F{sub 3} (RE = Tb, Dy, Ho)

    Energy Technology Data Exchange (ETDEWEB)

    Hinteregger, Ernst; Pitscheider, Almut; Wurst, Klaus; Heymann, Gunter; Huppertz, Hubert [Innsbruck Univ. (Austria). Inst. fuer Allgemeine, Anorganische und Theoretische Chemie; Enders, Michael [Innsbruck Univ. (Austria). Inst. fuer Pharmazie

    2013-11-15

    The new rare-earth fluoride borates RE{sub 2}(BO{sub 3})F{sub 3} (RE = Tb, Dy, Ho) were synthesized under high-pressure/high-temperature conditions of 1.5 GPa/1200 C for Tb{sub 2}(BO{sub 3})F{sub 3} and 3.0 GPa/900 C for Dy{sub 2}(BO{sub 3})F{sub 3} and Ho{sub 2}(BO{sub 3})F{sub 3} in a Walker-type multianvil apparatus from the corresponding rare-earth sesquioxides, rare-earth fluorides, and boron oxide. The single-crystal structure determinations revealed that the new compounds are isotypic to the known rare-earth fluoride borate Gd{sub 2}(BO{sub 3})F{sub 3}. The new rare-earth fluoride borates crystallize in the monoclinic space group P2{sub 1}/c (Z = 8) with the lattice parameters a = 16.296(3), b = 6.197(2), c = 8.338(2) A, {beta} = 93.58(3) for Tb{sub 2}(BO{sub 3})F{sub 3}, a = 16.225(3), b = 6.160(2), c = 8.307(2) A, {beta} = 93.64(3) for Dy{sub 2}(BO{sub 3})F{sub 3}, and a = 16.189(3), b = 6.124(2), c = 8.282(2) A, {beta} = 93.69(3) for Ho{sub 2}(BO{sub 3})F{sub 3}. The four crystallographically different rare-earth cations (CN = 9) are surrounded by oxygen and fluoride anions. All boron atoms form isolated trigonal-planar [BO{sub 3}]{sup 3-} groups. The six crystallographically different fluoride anions are in a nearly planar coordination by three rare-earth cations. (orig.)

  14. Determination of Fluoride Borate in Film-Forming Agent for Aluminum Surface by Spectrophotometry%分光光度法测定铝表面成膜剂中的氟硼酸根

    Institute of Scientific and Technical Information of China (English)

    陈泽民; 路品; 侯海平; 张新丽

    2011-01-01

    氟硼酸根能与苯羟乙酸以氢键结合,再与Fe(Phen)3]2+结合生成具有较大疏水基团的化合物,其具有可被有机试剂萃取的性质.萃取后,采用分光光度法测Fe2+,进而确定氟硼酸根的浓度.通过实验确定了最佳条件:萃取剂为1,2--氯乙烷,Fe(Phen)3]2+3.0 mL,1,2-二氯乙烷4.0mL,pH值为7.5,萃取振荡和静置时间分别为5 min和10 min,最大吸收波长为512 nm.该方法操作简单,共存因素无干扰,用于铝材成膜剂中氟硼酸根的测定,结果令人满意.%Fluoride borate can combine hydroxylated acid with hydrogen bonds, then further combine [Fe(Phen)3]2+ to form a compound with a big hydrophobic group, which can be extracted by organic reagent. After extraction, Fe2+ can be determined by spectrophotometry, and then the concentration of fluoride borate can be determined. The optimal conditions are determined by experiments: extractant is 1,2-dichloroethane, [Fe(Phen)3]2+ 3. 0 mL, 1,2-dichloroethane 4. 0 mL, pH 7. 5, vibrating time 5 min, vibrating laying time 10 min and maximum of wavelength absorbance 512 nm. This method is easy in operation with no interference by co-factors. It is satisfactory to use this method to determine fluoride borate in aluminum film former.

  15. Crystal structures and magnetic properties of lanthanide containing borates LnM(BO{sub 3}){sub 2} (Ln=Y, Ho–Lu; M=Sc, Cr)

    Energy Technology Data Exchange (ETDEWEB)

    Doi, Yoshihiro, E-mail: doi@sci.hokudai.ac.jp; Satou, Tatsuya; Hinatsu, Yukio

    2013-10-15

    The synthesis, crystal structures and magnetic properties of LnM(BO{sub 3}){sub 2} (Ln=Y, Ho–Lu; M=Sc, Cr) were investigated. The LnCr(BO{sub 3}){sub 2} compounds crystallize in the dolomite-type structure with space group R3{sup ¯}, in which the Ln and Cr ions occupy two octahedral sites. From the result of structural analysis, it was found that there is an anti-site disorder between these two sites and its chemical formula is more exactly Ln{sub 1−r}Cr{sub r}[Cr{sub 1−r}Ln{sub r}](BO{sub 3}){sub 2}. On the other hand, the LnSc(BO{sub 3}){sub 2} adopt the calcite-type structure with space group R3{sup ¯}c. The Ln and Sc ions randomly occupy an octahedral site and the chemical formula is represented as (Ln{sub 0.5}Sc{sub 0.5})BO{sub 3}. From the magnetic susceptibility and specific heat measurements, we found that all the LnCr(BO{sub 3}){sub 2} show an antiferromagnetic transition at 6.1–8.1 K. This transition is mainly due to the ordering of Cr{sup 3+} magnetic moments. Among the compounds with magnetic Ln{sup 3+} ions, only YbCr(BO{sub 3}){sub 2} shows an antiferromagnetic ordering of Ln{sup 3+} ion at 2.1 K. - Graphical abstract: The lanthanide containing borates LnM(BO{sub 3}){sub 2} (Ln=Y, Ho–Lu; M=Sc, Cr) have the dolomite-type (Ln=Cr) and calcite-type (Ln=Sc) structures. Both structures are similar to each other except for the difference in the partially or fully disordered arrangements of octahedral sites. At low temperatures, the LnCr(BO{sub 3}){sub 2} compounds show an antiferromagnetic transition due to a long-range ordering of Cr{sup 3+} moments. Among them only YbCr(BO{sub 3}){sub 2} shows an antiferromagnetic ordering of Ln{sup 3+} ion at 2.1 K. Display Omitted - Highlights: • Lanthanide containing borates LnM(BO{sub 3}){sub 2} (Ln=Y, Ho–Lu; M=Sc, Cr) have been synthesized. • LnCr(BO{sub 3}){sub 2} has the dolomite-type structure with an anti-site disorder between Ln and Cr sites. • LnSc(BO{sub 3}){sub 2} has the calcite

  16. Evolutionary Divergence of Plant Borate Exporters and Critical Amino Acid Residues for the Polar Localization and Boron-Dependent Vacuolar Sorting of AtBOR1.

    Science.gov (United States)

    Wakuta, Shinji; Mineta, Katsuhiko; Amano, Taro; Toyoda, Atsushi; Fujiwara, Toru; Naito, Satoshi; Takano, Junpei

    2015-05-01

    Boron (B) is an essential micronutrient for plants but is toxic when accumulated in excess. The plant BOR family encodes plasma membrane-localized borate exporters (BORs) that control translocation and homeostasis of B under a wide range of conditions. In this study, we examined the evolutionary divergence of BORs among terrestrial plants and showed that the lycophyte Selaginella moellendorffii and angiosperms have evolved two types of BOR (clades I and II). Clade I includes AtBOR1 and homologs previously shown to be involved in efficient transport of B under conditions of limited B availability. AtBOR1 shows polar localization in the plasma membrane and high-B-induced vacuolar sorting, important features for efficient B transport under low-B conditions, and rapid down-regulation to avoid B toxicity. Clade II includes AtBOR4 and barley Bot1 involved in B exclusion for high-B tolerance. We showed, using yeast complementation and B transport assays, that three genes in S. moellendorffii, SmBOR1 in clade I and SmBOR3 and SmBOR4 in clade II, encode functional BORs. Furthermore, amino acid sequence alignments identified an acidic di-leucine motif unique in clade I BORs. Mutational analysis of AtBOR1 revealed that the acidic di-leucine motif is required for the polarity and high-B-induced vacuolar sorting of AtBOR1. Our data clearly indicated that the common ancestor of vascular plants had already acquired two types of BOR for low- and high-B tolerance, and that the BOR family evolved to establish B tolerance in each lineage by adapting to their environments. PMID:25619824

  17. 亚微米硼酸锌(Firebrake415)的制备及表征%The Preparation, Characterization and Application of the Zinc Borates (FB415)

    Institute of Scientific and Technical Information of China (English)

    陈志玲; 孙雪峰; 李耀庭; 王和平

    2011-01-01

    Firebrake415, also called heat resistant boacic zinc, is now being advocated as a kind of new style boacic product. Its initial dehydration temperature is above 415 ℃, so it can be used as engineering plastics with very high processing temperature. The samples are prepared by electrical heating and microwave heating methods using ZnO and H3BO3 as raw materials, The samples synthesized by electrical heating with 5 hours treatment are stick crystal with diameter of 0. 2~0. 4 μm,and length of 2~6 μm; The samples synthesized by microwave heating with 20 minutes are submicron floury boacic zinc with diameter of less than 0. 2 μm . The zinc borate samples were analyzed with XRD, SEM, TEM and TG-DTA.%Firebrake415(也叫耐热硼酸锌)失水温度在415℃以上,可用于加工温度极高的工程塑料,是目前提倡使用的一种新型硼酸锌产品.以氧化锌、硼酸为原料,通过传统加热和微波辅助加热两种方法合成出产品Firebrake415,采用化学分析、XRD、SEM、TEM、TG-DTA对实验样品进行了分析表征,结果表明:传统加热5 h得到直径为0.2~0.5 μm,长度为2~6μm棒状晶体;微波加热20 min可得到产品粒径小于0.2 μm的亚微米级硼酸锌粉体.

  18. The effect of semiconducting CdSe and ZnSe nanoparticles on the fluorescence of Sm3+ in lead borate glasses

    Science.gov (United States)

    Mallur, Saisudha; Fatokun, Stephen; Babu, P. K.

    2015-03-01

    We studied the fluorescence spectra of Sm3+ doped lead borate glasses containing zinc selenide (ZnSe) and cadmium selenide (CdSe) nanoparticles with the following compositions (x PbO: 96.5-x B2O3:0.5 Sm2O3:3ZnSe/CdSe, x =36.5 and 56.5 mol%). These glass samples are prepared using the melt-quenching technique. Each sample is annealed just below the glass transition temperature at 400°C for 3 hrs and 6 hrs. We have chosen PbO-B2O3 glasses to incorporate Sm3+ ions because they have large glass forming region, high refractive index, and good physical and thermal stability. Fluorescence spectra of these samples are obtained with the excitation wavelength at 477 nm. Four fluorescence transitions are observed at 563 nm, 598 nm, 646 nm and 708 nm. The transition at 646 nm is found to be a hypersensitive transition that strongly depends on the covalency of the Sm-O bond and the asymmetry of the crystal field at Sm site. The 646 nm/598 nm fluorescence intensity ratio has been studied for different annealing times and PbO concentration for both ZnSe and CdSe samples. The presence of CdSe nanoparticles is seen to produce the greatest influence on the fluorescence intensity ratio. This could be due to the size of the CdSe nanoparticles and covalency of the Sm-O bond.

  19. The passive oxide films growth on 316L stainless steel in borate buffer solution measured by real-time spectroscopic ellipsometry

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Haisong; Wang, Lu; Sun, Dongbai [National Center for Materials Service Safety (NCMS), University of Science and Technology Beijing, Beijing 100083 (China); Yu, Hongying, E-mail: hyyu@ustb.edu.cn [Institute of Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083 (China)

    2015-10-01

    Highlights: • The optical properties of passive oxide films on 316L stainless steel were studied. • The thickness of the oxide films (1.5–2.6 nm) increased linearly with the potentials. • The growth of passive film followed high electric field ion conduction model. • Selective solubility of oxide induced compositional change of passive film. - Abstract: Passive film growth on 316L stainless steel was investigated in borate buffer electrolyte (pH = 9.1) by real-time spectroscopic ellipsometry (SE) and the composition was estimated by X-ray photoelectron spectroscopy (XPS). Anodic passivation of 316L SS was carried out in the potential range from 0 V{sub SCE} to 0.9 V{sub SCE}, after potentiostatic polarization for 1800s, the current density decayed from 10{sup −2} A cm{sup −2} to 10{sup −6} A cm{sup −2}. The passive film thickness was simulated from Frenel and Drude reflection equations, the average complex refractive index was assumed to be N = 2.3 − j0.445. The estimated thickness increased linearly with potential from 1.5 nm at 0 V to 2.6 nm at 0.8 V. The growth of passive film followed high electric field ion conduction model. The passive film mainly contained the oxide/hydroxide of iron and chromium. The selective solubility of oxide in passive film explained the change of iron and chromium content at different potentials. Few nickel and molybdenum also contributed to the passive film with a constant content.

  20. Evolutionary divergence of plant borate exporters and critical amino acid residues for the polar localization and boron-dependent vacuolar sorting of AtBOR1

    KAUST Repository

    Wakuta, Shinji

    2015-01-24

    Boron (B) is an essential micronutrient for plants but is toxic when accumulated in excess. The plant BOR family encodes plasma membrane-localized borate exporters (BORs) that control translocation and homeostasis of B under a wide range of conditions. In this study, we examined the evolutionary divergence of BORs among terrestrial plants and showed that the lycophyte Selaginella moellendorffii and angiosperms have evolved two types of BOR (clades I and II). Clade I includes AtBOR1 and homologs previously shown to be involved in efficient transport of B under conditions of limited B availability. AtBOR1 shows polar localization in the plasma membrane and high-B-induced vacuolar sorting, important features for efficient B transport under low-B conditions, and rapid down-regulation to avoid B toxicity. Clade II includes AtBOR4 and barley Bot1 involved in B exclusion for high-B tolerance. We showed, using yeast complementation and B transport assays, that three genes in S. moellendorffii, SmBOR1 in clade I and SmBOR3 and SmBOR4 in clade II, encode functional BORs. Furthermore, amino acid sequence alignments identified an acidic di-leucine motif unique in clade I BORs. Mutational analysis of AtBOR1 revealed that the acidic di-leucine motif is required for the polarity and high-B-induced vacuolar sorting of AtBOR1. Our data clearly indicated that the common ancestor of vascular plants had already acquired two types of BOR for low- and high-B tolerance, and that the BOR family evolved to establish B tolerance in each lineage by adapting to their environments. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists.

  1. The passive oxide films growth on 316L stainless steel in borate buffer solution measured by real-time spectroscopic ellipsometry

    International Nuclear Information System (INIS)

    Highlights: • The optical properties of passive oxide films on 316L stainless steel were studied. • The thickness of the oxide films (1.5–2.6 nm) increased linearly with the potentials. • The growth of passive film followed high electric field ion conduction model. • Selective solubility of oxide induced compositional change of passive film. - Abstract: Passive film growth on 316L stainless steel was investigated in borate buffer electrolyte (pH = 9.1) by real-time spectroscopic ellipsometry (SE) and the composition was estimated by X-ray photoelectron spectroscopy (XPS). Anodic passivation of 316L SS was carried out in the potential range from 0 VSCE to 0.9 VSCE, after potentiostatic polarization for 1800s, the current density decayed from 10−2 A cm−2 to 10−6 A cm−2. The passive film thickness was simulated from Frenel and Drude reflection equations, the average complex refractive index was assumed to be N = 2.3 − j0.445. The estimated thickness increased linearly with potential from 1.5 nm at 0 V to 2.6 nm at 0.8 V. The growth of passive film followed high electric field ion conduction model. The passive film mainly contained the oxide/hydroxide of iron and chromium. The selective solubility of oxide in passive film explained the change of iron and chromium content at different potentials. Few nickel and molybdenum also contributed to the passive film with a constant content

  2. Silicate, borosilicate, and borate bioactive glass scaffolds with controllable degradation rate for bone tissue engineering applications. I. Preparation and in vitro degradation.

    Science.gov (United States)

    Fu, Qiang; Rahaman, Mohamed N; Fu, Hailuo; Liu, Xin

    2010-10-01

    Bioactive glass scaffolds with a microstructure similar to that of dry human trabecular bone but with three different compositions were evaluated for potential applications in bone repair. The preparation of the scaffolds and the effect of the glass composition on the degradation and conversion of the scaffolds to a hydroxyapatite (HA)-type material in a simulated body fluid (SBF) are reported here (Part I). The in vitro response of osteogenic cells to the scaffolds and the in vivo evaluation of the scaffolds in a rat subcutaneous implantation model are described in Part II. Scaffolds (porosity = 78-82%; pore size = 100-500 microm) were prepared using a polymer foam replication technique. The glasses consisted of a silicate (13-93) composition, a borosilicate composition (designated 13-93B1), and a borate composition (13-93B3), in which one-third or all of the SiO2 content of 13-93 was replaced by B2O3, respectively. The conversion rate of the scaffolds to HA in the SBF increased markedly with the B2O3 content of the glass. Concurrently, the pH of the SBF also increased with the B2O3 content of the scaffolds. The compressive strengths of the as-prepared scaffolds (5-11 MPa) were in the upper range of values reported for trabecular bone, but they decreased markedly with immersion time in the SBF and with increasing B2O3 content of the glass. The results show that scaffolds with a wide range of bioactivity and degradation rate can be achieved by replacing varying amounts of SiO(2) in silicate bioactive glass with B2O3. PMID:20544804

  3. Spectroscopic, thermodynamic, kinetic studies and oxidase/antioxidant biomimetic catalytic activities of tris(3,5-dimethylpyrazolyl)borate Cu(II) complexes.

    Science.gov (United States)

    Shaban, Shaban Y; Ramadan, Abd El-Motaleb M; Ibrahim, Mohamed M; Mohamed, Mahmoud A; van Eldik, Rudi

    2015-08-21

    A series of copper(ii) complexes, viz. [Tp(MeMe)Cu(Cl)(H2O)] (), [Tp(MeMe)Cu(OAc)(H2O)] (), [Tp(MeMe)Cu(NO3)] () and [Tp(MeMe)Cu(ClO4)] () containing tris(3,5-dimethylpyrazolyl)borate (KTp(MeMe)), have been synthesized and fully characterized. The substitution reaction of with thiourea was studied under pseudo-first-order conditions as a function of concentration, temperature and pressure in methanol and acetonitrile as solvents. Two reaction steps that both depended on the nucleophile concentration were observed for both solvents. Substitution of coordinated methanol is about 40 times faster than the substitution of chloride. In acetonitrile, the rate constant for the displacement of coordinated acetonitrile was more than 20 times faster than the substitution of chloride. The reported activation parameters indicate that both reaction steps follow a dissociative mechanism in both solvents. On going from methanol to acetonitrile, the rate constant for the displacement of the solvent becomes more than 200 times faster due to the more labile acetonitrile, but the substitution mechanism remained to have a dissociative character. The antioxidant activities of were evaluated for superoxide dismutase (SOD), glutathione-s-transferase (GST0 and glutathione reduced (GSH-Rd) activity. and were found to show (p < 0.05) the highest antioxidant activity in comparison to and , which can be ascribed to the geometric configuration as well as the nature of the co-ligand. showed catechol oxidase activity with turnover numbers of 20 min(-1) and a coordination affinity for 3,5-DTBC of K1, = 31 mM(-1). K1 is rather large and seems to be typical for faster biomimetic models, and also for the enzyme itself (25 mM(-1)). The reaction rate depended linearly on the complex concentration, indicating a first-order dependence on the catalyst concentration. PMID:26172408

  4. Enhanced charging capability of lithium metal batteries based on lithium bis(trifluoromethanesulfonyl)imide-lithium bis(oxalato)borate dual-salt electrolytes

    Science.gov (United States)

    Xiang, Hongfa; Shi, Pengcheng; Bhattacharya, Priyanka; Chen, Xilin; Mei, Donghai; Bowden, Mark E.; Zheng, Jianming; Zhang, Ji-Guang; Xu, Wu

    2016-06-01

    Rechargeable lithium (Li) metal batteries with conventional LiPF6-carbonate electrolytes have been reported to fail quickly at charging current densities of about 1.0 mA cm-2 and above. In this work, we demonstrate the rapid charging capability of Li||LiNi0.8Co0.15Al0.05O2 (NCA) cells can be enabled by a dual-salt electrolyte of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and lithium bis(oxalato)borate (LiBOB) in a carbonate solvent mixture. The cells using the LiTFSI-LiBOB dual-salt electrolyte significantly outperform those using the LiPF6 electrolyte at high charging current densities. At the charging current density of 1.50 mA cm-2, the Li||NCA cells with the dual-salt electrolyte can still deliver a discharge capacity of 131 mAh g-1 and a capacity retention of 80% after 100 cycles. The Li||NCA cells with the LiPF6 electrolyte start to show fast capacity fading after the 30th cycle and only exhibit a low capacity of 25 mAh g-1 and a low retention of 15% after 100 cycles. The reasons for the good chargeability and cycling stability of the cells using the LiTFSI-LiBOB dual-salt electrolyte can be attributed to the good film-formation ability of the electrolyte on the Li metal anode and the highly conductive nature of the sulfur-rich interphase layer.

  5. Thermodynamic properties of two zinc borates: 3ZnO·3B2O3·3.5H2O and 6ZnO·5B2O3·3H2O

    International Nuclear Information System (INIS)

    Highlights: • Two zinc borates 3ZnO·3B2O3·3.5H2O and 6ZnO·5B2O3·3H2O have been synthesized and characterized. • Enthalpies of solution of both zinc borates were measured by microcalorimeter. • Enthalpies of solution of ZnO were also measured by microcalorimeter. • ΔfHmθ for both zinc borates were obtained by thermochemical cycles. - Abstract: Two pure zinc borates with microporous structure 3ZnO·3B2O3·3.5H2O and 6ZnO·5B2O3·3H2O have been synthesized and characterized by XRD, FT-IR, TG techniques and chemical analysis. The molar enthalpies of solution of 3ZnO·3B2O3·3.5H2O(s) and 6ZnO·5B2O3·3H2O(s) in 1 mol · dm−3 HCl(aq) were measured by microcalorimeter at T = 298.15 K, respectively. The molar enthalpies of solution of ZnO(s) in the mixture solvent of 2.00 cm3 of 1 mol · dm−3 HCl(aq) in which 5.30 mg of H3BO3 were added were also measured. With the incorporation of the previously determined enthalpy of solution of H3BO3(s) in 1 mol · dm−3 HCl(aq), together with the use of the standard molar enthalpies of formation for ZnO(s), H3BO3(s), and H2O(l), the standard molar enthalpies of formation of −(6115.3 ± 5.0) kJ · mol−1 for 3ZnO·3B2O3·3.5H2O and −(9606.6 ± 8.5) kJ · mol−1 for 6ZnO·5B2O3·3H2O at T = 298.15 K were obtained on the basis of the appropriate thermochemical cycles

  6. Rotameric transformations in the photochemistry of TpM(CO)2(η(3)-C3H4R), where Tp = tris(pyrazolyl)borate, M = Mo or W, and R = H or Me.

    Science.gov (United States)

    Thornley, Wyatt A; Bitterwolf, Thomas E

    2015-05-01

    Low energy photolysis of TpM(CO)2(η(3)-C3H4R), where Tp = tris(pyrazolyl)borate, M = Mo or W, and R = 2-H or 2-Me in PVC matrices at 85 K results in exo/gauche isomerism of the allyl ligand. This transformation comes in contrast to the behaviour observed in cyclopentadienyl analogues which undergo exo/endo isomerism. DFT computations reveal an η(3) → η(1)* → η(3) mechanism for the allyl rotameric interconversion where the η(1)*-allyl intermediate is generated upon MLCT excitation.

  7. Bis-Indole Derivatives for Polysaccharide Compositional Analysis and Chiral Resolution of D-, L-Monosaccharides by Ligand Exchange Capillary Electrophoresis Using Borate-Cyclodextrin as a Chiral Selector

    Directory of Open Access Journals (Sweden)

    Wen-Bin Yang

    2011-02-01

    Full Text Available A series of aldo-bis-indole derivatives (aldo-BINs was prepared by aromatic C-alkylation reactions of aldoses and indole in acetic acid solution. Common monosaccharides such as glucose, mannose, galactose, fucose, xylose, rhamnose, ribose, arabinose and N-acetylglucosamine were smoothly derivatized to form the UV absorbing aldo-BINs. The use of a capillary electrophoretic method to separate these novel aldo-BIN derivatives was established. The capillary electrophoresis conditions were set by using borate buffer (100 mM at high pH (pH 9.0. The limit of determination was assessed to be 25 nM. The enantioseparation of D, L-pairs of aldo-BINs based on chiral ligand-exchange capillary electrophoresis technology was also achieved by using modified hydroxypropyl-β-cyclodextrin as the chiral selector in the presence of borate buffer. This aldose labeling method was applied successfully to the compositional and configurational analysis of saccharides, exemplified by a rapid and efficient method to simultaneously analyze the composition and configuration of saccharides from the medicinal herbs Cordyceps sinensis and Dendrobium huoshanense.

  8. DPAB对中密度纤维板性能的影响%Influence of Didecyl Polyoxyethyl Ammonium Borate(DPAB) on Properties of Medium Density Fiberboard

    Institute of Scientific and Technical Information of China (English)

    王星; 曹金珍; 崔福通

    2013-01-01

    用二癸基二羟乙基硼酸铵(DPAB)与酚醛树脂胶黏剂混合制备中密度纤维板,并与未添加DPAB的酚醛树脂制备的中密度纤维板的物理力学性能和阻燃性能进行比较.结果表明:DPAB添加量低于1.2%时对中密度纤维板的静曲强度和弹性模量无显著影响,且随着添加量的增加氧指数增大,残炭量也有一定的增加,说明DPAB的添加对中密度纤维板的阻燃性能有一定的改善.由DSC分析得知,DPAB的添加使酚醛树脂固化更完全,但DPAB的亲水性使改性中密度纤维板的吸水性和吸水厚度膨胀率与未改性中密度纤维板相比有所增大.%The mechanical and fire-retarding properties of medium density fiberboard ( MDF) prepared by u-sing phenol formaldehyde resin mixed with didecyl polyoxyethyl ammonium borate ( DPAB) were compared with MDF control without DPAB. The results showed that there was no significant effect on modulus of rupture (MOR) nor modulus of elasticity (MOE) of the MDF when the dosage of DPAB added was below 1.2%. The oxygen index as well as the residual carbon content were increased with the increment of DPAB dosage, suggesting that the addition of DPAB could improve the fire retardation of MDF. Compared to MDF control, DPAB adding made the resin cure more completely according to the results of DSC analyses. However, the water uptake and swelling ratio of MDF upon water absorption were also increased with the DPAB loading due to the hydrophilic property of DPAB.

  9. Synthesis, characterization, and electrochemistry of cis-oxothio- and cis-bis(thio)tungsten(VI) complexes of hydrotris(3,5-dimethylpyrazol-1-yl)borate.

    Science.gov (United States)

    Eagle, A A; Tiekink, E R; George, G N; Young, C G

    2001-08-27

    The complexes TpWO2X react with sulfiding agents such as B2S3 or P4S10 to give the oxothio- and bis(thio)tungsten(VI) complexes TpWOSX (X = Cl(-)) and TpWS2X [X = Cl(-), S2PPh2(-); Tp = hydrotris(3,5-dimethylpyrazol-1-yl)borate]. The reaction of TpWS2Cl with (i) PPh3 in pyridine and (ii) dimethyl sulfoxide affords TpWOSCl in good overall yield. The chloro complexes undergo metathesis with alkali metal salts to yield species of the type TpWOSX and TpWS2X [X = OPh(-), SPh(-), SePh(-), (-)-mentholate]. The diamagnetic complexes exhibit NMR spectra indicative of C(1) (TpWOSX) or C(s) (TpWS2X) symmetry and IR spectra consistent with terminal oxo and thio ligation (nu(W=O), 940-925 cm(-1); nu(W=S) or nu(WS2), 495-475 cm(-1)). Crystals of (R,S)-TpWOS[(-)-mentholate] are monoclinic, space group P2(1), with a = 11.983(2) A, b = 18.100(3) A, c = 13.859(3) A, beta = 91.60(2) degrees, V = 3004.6(8) A(3), and Z = 4. Crystals of TpWS2(OPh)-CH2Cl2 are orthorhombic, space group Pbca, with a = 16.961(4) A, b = 33.098(7) A, c = 9.555(2) A, V = 5364(2) A(3), and Z = 8. The mononuclear, distorted-octahedral tungsten centers are coordinated by a tridentate Tp ligand, an alkoxy or aryloxy ligand, and two terminal chalcogenide ligands. The average W=O and W=S distances are 1.726(7) and 2.125(2) A, respectively, and the O=W=S and S=W=S angles 102.9(3) and 102.9(1) degrees, respectively. The tungsten and sulfur X-ray absorption spectra of TpWOSCl and TpWS2Cl are consistent with the presence of terminal pi-bonded thio ligands in both complexes. The thio complexes generally undergo a reversible one-electron reduction at potentials significantly more positive than their oxo analogues. The chemical, spectroscopic, and electrochemical properties of the complexes are heavily influenced by the presence of W=S pi frontier orbitals.

  10. 硼酸双甘油葡萄糖苷月桂酸酯的合成及性能研究%Synthesis and properties of double-glycerol glycosides borate laurate surfactant

    Institute of Scientific and Technical Information of China (English)

    韩冰; 吕彤; 梁婧宇

    2012-01-01

    Doiihle-glycerol glycosides borate laurate surfactant is prepared by taking glycerol glucoside boric acid, lauric acid as main materials, and it is analyzed and characterized by IR and 1H-NMR. The experimental results show that double—glycerol glucoside borate ester as an intermediate, which is reacted with lauric acid, catalysed by paratoluenesulfonic acid, the double-glycerol borate laurate glycosides is obtained with the total amount of catalyst for the reaction of 0.5%, 30 mL of acetonitrile as solvent and reaction time 150 mm. Besides,the critical micelle concentration and the corresponding surface tension of the target product are 1.16×10 2 mol/L and 36.0 mN/m(20 ℃), respectively. The target product shows good emulsifiability.%以甘油葡萄糖苷、硼酸为原料,以对甲苯磺酸做催化剂,与月桂酸经酯化反应合成硼酸双甘油葡萄糖苷月桂酸酯表面活性剂,并采用红外光谱仪、核磁共振谱仪表征产物结构.实验结果表明:硼酸双甘油葡萄糖苷酯作为中间体与月桂酸进行反应,以用量为反应物总质量0.5%的对甲苯磺酸为催化剂,用30mL的乙腈作为溶剂,在80℃下反应150min,得到目标产物;其表面活性剂的表面张力为36.0mN/m(20℃),临界胶束浓度为1.16×10-2mol/L,并显示出良好的乳化性能.

  11. Study on Properties of Hydrophobic Zinc Borate and Magnesium Hydroxide Synergistically Flame-retarded EVA%疏水硼酸锌与氢氧化镁协同阻燃EVA的性能研究

    Institute of Scientific and Technical Information of China (English)

    徐建中; 唐婷婷; 屈红强; 尚俊敏; 牛世杰

    2012-01-01

    使用硫酸锌、硼砂为原料,油酸为改性剂,采用一步法制备疏水硼酸锌(Zn2B6O11·3H2O)。用x射线衍射仪、傅里叶变换红外光谱仪、扫描电子显微镜、接触角测定仪等设备对样品的物相、形貌、疏水性进行了分析。结果表明,所制备的硼酸锌直径为1~2μm,片层厚度为0.1μm,接触角为105.1°;将硼酸锌与氢氧化镁[Mg(OH)2]复配用于乙烯-醋酸乙烯共聚物(EVA)阻燃时具有很好的协同阻燃作用,极限氧指数达到了38.5%;在EVA配方中加入疏水硼酸锌,复合材料的力学性能下降较慢,且优于加入相同量市售硼酸锌的复合材料。%Hydrophohic zinc borate (Zn2g6O11·3H2O) was prepared via a one-step wet synthesis from zinc sulfate and sodium borate, with oleic acid as the surfactant. The morphology and hydrophobic property of the products were analyzed by means of X-ray diffraction, Fourier transform infrated spectroscopy, contact angle analyzer, and scanning electron microscope. It indicated that the diameter and thickness of the products were 1-2μm and 0. 1 μm, respectively; the water contact angle was 105.1°. The prepared hydrophobic zinc borate was introduced into EVA/ Mg(OH)2 composites as a flame retardant. A synergetic effect was observed, the value of limited oxygen index reached 38. 5%, and the mechanical properties were only moderately decreased.

  12. AP/RDX/AI/HTPB推进剂用硼酸酯键合剂的合成与应用研究%Synthesis and application of borate bonding agents for AP/RDX/Al/HTPB propellant

    Institute of Scientific and Technical Information of China (English)

    崔瑞禧; 张炜; 陈浪

    2012-01-01

    Aiming at the existing problems of processing property and mechanical property of high-energy hydroxyl-terminated polybutadiene propellant, the new borate-ester bonding agents wa9 synthesized. With the dieihanolamine,l-bromobutane,acryloni-trile.and glacial acetic acid as raw materials,the intermediates N.N-two hydroxyethyl n-butyl amine,N-(2-cyanoethyl) dielhano-lamine.and N.N-two hydroxyethyl ethyl amide were synthesized. The reaction product of diethanolamine and acrylonitrile was analyzed by using IR and CC-MS method. It has been testified that the product is target compound. Four kinds of new borate-ester bonding agents were synthesized by utilizing the synthesized intermediates as well as the methyldiethanolamine and tributyl borate. By u-sing the formula of high-energy hydroxyl-terminated polybutadiene propellant, it has been verified that all the newly synthesized bonding agents could improve the flow of the slurry, and among them, BA-3, BA-4 have good bonding effects, which significantly improve the mechanical properties of the propellants.%针对丁羟四组元推进剂存在的工艺性能与力学性能的问题,设计合成了新型硼酸酯键合剂.选用二乙醇胺、1-溴代正丁烷、丙烯腈、冰乙酸为原料,合成了N,N-二羟乙基正丁胺、N-(2-腈乙基)二乙醇胺、N,N-二羟乙基乙酰胺中间体.对二乙醇胺和丙烯腈反应的产物做了红外和气-质联用分析,证实合成产物为目标化合物.利用所合成的中间体及甲基二乙醇胺与硼酸三正丁酯,合成了4种新型硼酸酯键合剂,采用丁羟四组元推进剂配方装药,验证了它们的使用效果.结果表明,新合成的4种键合剂都能明显改善药浆流动流平性,其中BA-3和BA-4具有很好的键合效果,显著提升了推进剂的力学性能.

  13. Acoustooptic Diffraction in Borate Crystals

    CERN Document Server

    Martynyuk-Lototska, I; Krupych, O; Adamiv, V; Smirnov, Ye; Vlokh, R

    2004-01-01

    The efficiency of acoustooptic (AO) diffraction in a-BaB2O4 and Li2B4O7 crystals is studied experimentally. The crystals are shown to be quite good AO materials. The efficiency of AO diffraction in a-BaB2O4 reaches h=30% at the electric signal power of P=0.7W for the transverse acoustic wave and 15% at the power of P=0.56W for the longitudinal wave. The same parameter for Li2B4O7 reaches h=21% at P=0,81W for the longitudinal acoustic wave.

  14. Heterometal cubane-type MFe(3)S(4) clusters (M = Mo, V) trigonally symmetrized with hydrotris(pyrazolyl)borate(1-) and tris(pyrazolyl)methanesulfonate(1-) capping ligands.

    Science.gov (United States)

    Fomitchev, Dmitry V; McLauchlan, Craig C; Holm, R H

    2002-02-25

    previously reported double cubanes of higher charge. Trigonally symmetric single cubanes eliminate isomers in the formation of double cubanes and other cluster structures, and may be of considerable value in the preparation of new types of M-Fe-S clusters. (Tpms = tris(pyrazolyl)methanesulfonate(1-); Tp = hydrotris(pyrazolyl)borate(1-).)

  15. Synthesis and Characterization of Network Single Ion Conductors(NSIC) Based On Comb-Branched Polyepoxide Ethers and LithiumBis(allylmalonato)borate

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Xiao-Guang; Kerr, John B.

    2004-07-11

    Network single ion conductors (NSICs) based on comb-branch polyepoxide ethers and lithium bis(allylmalonato) borate have been synthesized and thoroughly characterized by means of ionic conductivity measurements, electrochemical impedance and by dynamic mechanical analysis (DMA). The materials have been tested as battery electrolytes by cycling in symmetrical Li/Li half cells and in Li/V{sub 6}O{sub 13} full cells in which the NSIC was used as both binder and electrolyte in the cathode electrode and as the electrolyte separator membrane,. The substitution of the trimethylene oxide (TMO) unit into the side chains in place of ethylene oxide (EO) units increased the polymerion mobility (lower glass transition temperature). However, the ionic conductivity was nearly one and half orders of magnitude lower than the corresponding pure EO based single ion conductor at the same salt concentration. This effect may be ascribed to the lower dielectric constant of the TMO side chains that result in a lower concentration of free conducting lithium cations. For a highly cross-linked system (EO/Li=20), only 47 wt% plasticizing solvent (ethylene carbonate (EC)/ethyl methyl carbonate (EMC), 1/1 by wt) could be taken up and the ionic conductivity was only increased by one order of magnitude over the dry polyelectrolyte while for a less densely crosslinked system (EO/Li=80), up to 75 wt% plasticizer could be taken up and the ionic conductivity was increased by nearly two orders of magnitude. A Li/Li symmetric cell that was cycled at 85 C at a current density of 25{micro}Acm{sup -2} showed no concentration polarization or diffusional relaxation, consistent with a lithium ion transference number of one. However, both the bulk and interfacial impedances increased after 20 cycles, apparently due to continued cross-linking reactions within the membrane and on the surface of the lithium electrodes. A Li/V{sub 6}O{sub 13} full cell constructed using a single ion conductor gel (propylene

  16. Unusually slow formation of ion-pair charge-transfer complex between 4,4'-bipyridinium and tetrakis(3,5-bis(trifluoromethyl)-phenyl)borate in organic solutions

    Energy Technology Data Exchange (ETDEWEB)

    Nagamura, T.; Sakai, K. (Kyushu Univ., Fukuoka (Japan). Dept. of Molecular Science and Technology)

    1988-06-01

    4,4'-Bipyridinium salts with tetrakis(3,5-bis(trifluoromethyl)-phenyl)borate anion (abbreviated to TFPB{sup -}) showed a charge-transfer (CT) absorption above 350 nm with a discrete peak at about 475 nm in 1,2-dimethoxyethane and at 420 nm in methanol. The absorbance of a CT band increased very gradually to the equilibrium dependent on temperature. The CT fluorescence showed similar very slow growth. The observed time-dependences of absorbance and fluorescence were well explained by the temperature-dependent formation and dissociation of CT complexes. Very slow growth was attributed to the unusually small pre-exponential factor, which was most probably due to the extraordinary bulkiness of TFPB{sup -}. (orig.).

  17. Theoretical Investigation of the Structures of Borate Esters and Their Bonding Interaction with RDX%硼酸酯键合剂分子结构及其与RDX晶面相互作用的理论研究

    Institute of Scientific and Technical Information of China (English)

    崔瑞禧; 张炜

    2012-01-01

    运用量子化学方法计算了5种硼酸酯键合剂(BEBA)的分子结构和分子轨道,发现5种BEBA分子硼原子所处空轨道的能级较高.利用晶面吸附模型和分子动力学方法研究了上述键合剂与RDX(210)、RDX(200)晶面之间的相互作用能,发现键合剂在不同RDX晶面上的结合模式不同且具有选择性.键合剂与RDX(200)晶面的结合能大于其与RDX(210)晶面的结合能.BEBA_1和BEBA_2能够在两个晶面上获得较好的结合能力.BEBA 5在RDX(210)和RDX(200)晶面上相对结合能力相反,即在RDX(210)/BEBA_5中结合最好.推测由于RDX (200)晶面最表层氧原子含量相对较少,有利于甲酰丙酮基上的羰基与RDX上的NO2产生诱导效应,产生很强的结合作用,抵消并补偿了由于BEBA_5中胺氮负电荷减少而造成结合能的降低.%Theoretical calculation was used to investigate the molecular structures and orbitals of five BEBA molecules. Relative to trimethyl borate, the lowest unoccupied molecular orbital ( LUMO) images of five BEBAs (1 -5 ) molecules show that the orbitals do not appear around borate groups, and their energy levels of those unoccupied molecular orbitals around boron atom are higher. Molecular dynamics simulation was performed to investigate the interaction between title borate esters and RDX(210) as well as RDX(210) crystal faces. An obvious binding selectivity of these borate esters on RDX crystal surfaces is found. The binding energies of RDX (200 )/BEBAs are higher than that of RDX ( 210 )/BEBA ( 1 -5). The theoretical evaluation for the binding performances of BEBA1 and BEBA_2 with RDX are good enough, whereas the binding performances of RDX(210) /BEBA_5 and RDX(200)/BEBA_5 are contrary. It is speculated that less oxygen content of the most superficial surface of RDX(200) is benefit of forming induced effects between carbonyl of BEBA_5 and NO2 in RDX. Such a strong combination between them offsets or even compensates the lowering of binding

  18. 硼酸镧纳米棒的制备及其在植物油中的抗磨减摩性能%Preparation,friction reducing and anti-wear properties of lanthanum borate nanorods in vegetable oil

    Institute of Scientific and Technical Information of China (English)

    谷科城; 陈波水; 陈勇; 闫忠意; 韦友亮

    2014-01-01

    Lanthanum borate nanorods were prepared via hydrothermal method using Na2B4O7·10H2O and La(NO3)3·6H2O as raw materials,and oleic acid as the modifying agent. The microstructure of as-prepared samples was characterized by X-ray diffraction (XRD),Fourier transform infrared spectrometry(FT-IR),scanning electron microscope(SEM)and energy-dispersive X-ray spec-trometer(EDS). In the meantime,friction reducing and anti-wear properties of lanthanum borate as lubricant additives in vegetable oil were evaluated with a four-ball friction and wear tester. The morphology as well as elemental composition of worn steel surfaces were investigated by SEM and EDS. Results showed that as-prepared lanthanum borate displayed nanorod morphology with diameters of 50 nm and lengths up to 500 nm. Moreover,the lanthanum borate nanorods could obviously improve the anti-wear and frictiong re-ducing properties of vegetable oil. The optimal anti-wear and friction reducing abilities were obtained at an additive content of 1 wt.%. XPS analysis showed that the formation of a lubrication film mainly composed of the oxides of iron,boron and lanthanum as well as the formation of an adsorption film of oleic acid on the rubbing surfaces,which provided the vegetable oil with good lubrica-ting properties.%以Na2B4O7·10H2O和La(NO3)3·6H2O作原料,油酸作改性剂,采用水热法制备了硼酸镧纳米棒。利用X-衍射仪、FT-IR光谱仪、扫描电镜及能谱仪对其结构进行了表征,采用四球摩擦试验机考察了其在植物油中的抗磨减摩性能,利用扫描电镜观察了钢球表面磨斑的形貌,X射线光电子能谱测定了磨斑的元素组成。结果表明,硼酸镧呈纳米棒结构,其直径为50 nm、长达500 nm。硼酸镧纳米棒能显著提高植物油的抗磨、减摩性能,当添加剂的含量为1wt.%时,植物油的抗磨、减摩性能达到最佳。 XPS分析结果表明,在钢球表面形成了一层含油酸的吸附膜和一层含Fe2 O3、B2 O3

  19. Combustion synthesis and optical properties of Oxy-borate phosphors YCa{sub 4}O(BO{sub 3}){sub 3}:RE{sup 3+} (RE = Eu{sup 3+}, Tb{sup 3+}) under UV, VUV excitation

    Energy Technology Data Exchange (ETDEWEB)

    Ingle, J.T. [Department of Physics, J.D. Institute of Engineering and Technology, Yavatmal (India); Gawande, A.B. [Department of Physics, G.S. Science, Arts and Commerce College, Khamgaon (India); Sonekar, R.P., E-mail: sonekar_rp@yahoo.com [Department of Physics, G.S. Science, Arts and Commerce College, Khamgaon (India); Omanwar, S.K. [Department of Physics, S.G.B. Amravati University, Amravati (India); Wang, Yuhua; Zhao, Lei [Department of Materials Science, School of Physical Science and Technology, Lanzhou University, Lanzhou (China)

    2014-02-05

    Graphical abstract: VUV Photoluminescence of YCa{sub 4}O(BO{sub 3}){sub 3}: Eu{sup 3+} and YCa{sub 4}O(BO{sub 3}){sub 3}: Tb{sup 3+} for PDPs applications. Highlights: • Inorganic Oxy-borate phosphors YCa{sub 4}O(BO{sub 3}){sub 3}:Eu{sup 3+},Tb{sup 3+} was synthesized by novel solution combustion synthesis. • This single host produces efficient and intense Red and Green color for display applications. • Good agreement with CIE co-ordinates as prescribes by NTCL, for flat panel, PDP display color. • Synthesized materials were characterized using powder XRD, FE-SEM, UV and VUV Spectophotometer. -- Abstract: The inorganic Oxy-borate host phosphors YCa{sub 4}O(BO{sub 3}){sub 3}:RE{sup 3+} (RE = Eu{sup 3+},Tb{sup 3+}) were synthesized by a novel solution combustion technique. The synthesis is based on the exothermic reaction between the fuel (Urea) and Oxidizer (Ammonium nitrate). The heat generated in reaction is use for auto combustion of precursors. The structures of the prepared samples were confirmed by powder XRD technique. The photoluminescence properties of the powder samples were investigated under UV and VUV excitation; “The phosphor YCa{sub 4}O(BO{sub 3}){sub 3}:Eu{sup 3+}and YCa{sub 4}O(BO{sub 3}){sub 3}:Tb{sup 3+} shows strong absorption in UV and VUV region and exhibits intense red and green emission upon excited by 254 nm UV and 147 nm VUV radiation”.

  20. 阻燃剂低水硼酸锌的微波水热合成与表征%Microwave hydrothermal synthesis and characterization of flame retardant low-hydrated zinc borate

    Institute of Scientific and Technical Information of China (English)

    刘霞; 丁长增; 李杨; 李柯宏; 张晗; 张丽芳; 荣华

    2013-01-01

    Low-hydrated zinc borate (2ZnO·3B2O3·3H2O) was prepared by microwave hydrothermal method with ZnO and H3BO3 as raw materials.The structure, properties, and morphology of the prepared zinc borate were characterized by means of X-ray powder diffraction (XRD),thermogravimetric (TG-DTA) ,and scanning electron microscopy (SEM) etc..At the same time, different factors affecting the microwave hydrothermal process were discussed.The suitable synthesis conditions were confirmed through optimized experiments.Experimental results showed that the XRD spectrum of the obtained product was in agreement with the standard spectrum of 2ZnO·3B2O3·3H2O,the dehydration temperature of the sample was above 360 ℃, and the grain size was at 1~2 μm after aging.%以氧化锌、硼酸为原料,利用微波水热法制备了低水硼酸锌(2ZnO· 3B2O3· 3H2O).借助X射线衍射(XBD)、热重-差热(TG-DTA)、扫描电镜(SEM)等分析测试手段,对合成的低水硼酸锌粉体的结构、性质和形貌进行了表征,并讨论了影响微波水热合成的诸因素,确定了适宜的合成条件.结果表明:所得产物的XRD谱图与2ZnO·3B2O3· 3H2O一致,脱水温度高于360℃,经陈化后粒径为1~2 μm.

  1. Influence of structural distortions upon photoluminescence properties of Eu{sup 3+} and Tb{sup 3+} activated Na{sub 3}Ln(BO{sub 3}){sub 2} (Ln=Y, Gd) borates

    Energy Technology Data Exchange (ETDEWEB)

    Asiri Naidu, S. [Laboratoire CRISMAT (CNRS UMR6508), ENSICAEN, Universite de Caen, 6 Bd Marechal Juin, 14050 Caen Cedex (France); Boudin, S., E-mail: sophie.boudin@ensicaen.fr [Laboratoire CRISMAT (CNRS UMR6508), ENSICAEN, Universite de Caen, 6 Bd Marechal Juin, 14050 Caen Cedex (France); Varadaraju, U.V. [Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036 (India); Raveau, B. [Laboratoire CRISMAT (CNRS UMR6508), ENSICAEN, Universite de Caen, 6 Bd Marechal Juin, 14050 Caen Cedex (France)

    2012-06-15

    The comparative study of the structure and photoluminescence (PL) properties of the Eu{sup 3+} and Tb{sup 3+} activated Na{sub 3}Ln(BO{sub 3}){sub 2}, with Ln=Y, Gd, showed the important role of the host lattice structure upon PL. Higher emission intensities of Eu{sup 3+} and Tb{sup 3+} are observed for Na{sub 3}Gd(BO{sub 3}){sub 2} than for Na{sub 3}Y(BO{sub 3}){sub 2}, through direct Eu{sup 3+} excitation at 395 nm for Eu{sup 3+} doped borates, and through Gd{sup 3+} excitation around 280 nm for Tb{sup 3+} doped borates. This higher performance for Na{sub 3}Gd(BO{sub 3}){sub 2} is due to the less regular environment of Eu{sup 3+} (Tb{sup 3+}) in the Gd sites than in the Y sites and to energy transfer from Gd{sup 3+} to Eu{sup 3+}(Tb{sup 3+}). The smaller critical concentration in Na{sub 3}Ln{sub 1-x}Tb{sub x}(BO{sub 3}){sub 2} observed for Ln=Gd, x=0.5, compared to x=0.6 for Ln=Y, is explained by shorter Ln-Ln distances (4.11 A for Gd-Gd vs. 4.59 A for Y-Y). Both Na{sub 3}Y{sub 0.4}Tb{sub 0.6}(BO{sub 3}){sub 2} and Na{sub 3}Gd{sub 0.5}Tb{sub 0.5}(BO{sub 3}){sub 2} show intense green emission under UV excitation. - Graphical abstract: The PL properties of Eu{sup 3+} and Tb{sup 3+} are studied in Na{sub 3}Ln(BO{sub 3}){sub 2} (Ln=Y, Gd) borates. Eu{sup 3+} and Tb{sup 3+}exhibits higher emission intensity in Na{sub 3}Gd(BO{sub 3}){sub 2} compared to Na{sub 3}Y(BO{sub 3}){sub 2} due to the less regular environment of the Gd{sup 3+} ion. Energy transfer from Gd{sup 3+} to Tb{sup 3+} is observed. Highlights: Black-Right-Pointing-Pointer Crystal structure of Na{sub 3}Gd(BO{sub 3}){sub 2} by X-ray powder diffraction. Black-Right-Pointing-Pointer Photoluminescence properties of Eu{sup 3+} and Tb{sup 3+} doped Na{sub 3}Ln(BO{sub 3}){sub 2} (Ln=Y, Gd). Black-Right-Pointing-Pointer Higher Eu{sup 3+} and Tb{sup 3+} emission for Na{sub 3}Gd(BO{sub 3}){sub 2} due to an irregular environment of Gd{sup 3+}. Black-Right-Pointing-Pointer Higher Eu{sup 3+} and Tb{sup 3+} emission

  2. PARTICLES ASSOCIATION STUDY OF A BORATE SAMPLE FROM SIJES DISTRICT, ARGENTINA ESTUDIO DE LA ASOCIACIÓN DE PARTÍCULAS DE UNA MUESTRA DE BORATOS DEL DISTRITO SIJES, ARGENTINA

    Directory of Open Access Journals (Sweden)

    Rosa M Torres Sánchez

    2007-04-01

    Full Text Available The increasing range of borate uses, mainly in the ceramic frit market, led borate producers to improve competitiveness through concentration and/or purification steps in the mill circuit as well as in the characterization of high content B2O3 minerals. Minerals coming from Sijes, Salta Province, Argentina, mainly identified as colemanite and hydroboracite, with 50.84 % and 50.54 % B2O3 respectively, are potentially interesting from an industrial point of view. The desliming purification technique in hydrocyclones used to upgrade B2O3 and downgrade undesirable impurities to the borate market (Rietveld method mainly iron oxides, chlorides and sulphates not only eliminates slimes but it also generates pores, through a decrease of the specific surface of the particles. Two samples under different purification steps were analyzed: deslimed and without desliming. The chemical and mineralogical analyses of both samples indicate a decreasing percentage of colemanite, smectite and illite in the deslimed sample with a small increase of hibroracite. The parameters of surface electric charge (PZC and IEP match the observations made with the electronic microscopy, reveal mineral associations only in the sample without desliming.La ampliación de los mercados que utilizan borato, principalmente el de la producción de fritas cerámicas, ha llevado a los productores de dicho mineral a mejorar su competitividad a través de su concentración y/o purificación tanto por medio de su molienda así como mediante la caracterización de minerales con alto contenido en B2O3. En los minerales provenientes de Sijes, Provincia de Salta, Argentina, se han identificado principalmente colemanita e hidroboracita, con 50.84% y 50.54% en B2O3, respectivamente, lo cual los hace potencialmente interesantes para su utilización industrial. La técnica de purificación por deslamado en hidrociclón para purificar B2O3, permite la disminución de impurezas indeseables para la

  3. 锌硼玻璃基低温共烧陶瓷的微波介电性能研究%Microwave dielectric properties of zinc borate glass-based low temperature co-fired ceramics

    Institute of Scientific and Technical Information of China (English)

    周东祥; 孙荣光; 胡云香

    2011-01-01

    Zinc borate glass/ceramic composites for low temperature co-fired ceramics (LTCC) were prepared from the mixtures of zinc borate glass, Al203 and TiO2. The effects of the mass ratio of TiO2 to Al203 on the phase evolution and dielectric properties of prepared composites were investigated. The results show that the content of ZnAl2O4, TiO2 and 4ZnO · 3B203 in the composites increases, decreases,remains essentially unchanged respectively with the decrease of the mass ratio of TiO2 to Al203. The permittivity and dielectric loss of these composites increase significantly with the increase of the mass ratio of TiO2 to Al203. A near-zero temperature coefficient of resonant frequency of the composite is obtained when the mass fraction ofTiO2 is 8%.%采用3ZnO-2B2O3玻璃与Al2O3和TiO2复合烧结制备了锌硼玻璃基低温共烧陶瓷复合材料,研究了TiO2/Al2O3质量比对所制复合材料相组成和微波介电性能的影响.结果表明:随着TiO2/Al2O3质量比减少,复合材料中ZnAl2O4相含量增多,TiO2相含量减少,4ZnO·3B2O3相的含量基本不变.随着TiO2/Al2O3质量比增大,复合材料的介电常数和介质损耗增大.当TiO2的质量分数为8%时,复合材料的谐振频率温度系数接近于零.

  4. Influence of Zinc Borates(ZB)on Property of Halogen-free Flame-Retarded Poly(Vinyl Chloride)%ZB对无卤阻燃PVC体系性能的影响

    Institute of Scientific and Technical Information of China (English)

    魏方明; 王庭慰; 邵海彬

    2011-01-01

    研究氢氧化铝(ATH)对聚氯乙烯力学性能的影响,并在此基础上研究硼酸锌(ZB)对无卤阻燃聚氯乙烯体系的力学性能、阻燃性能以及电学性能的影响.结果表明:随着硼酸锌的加入,体系的力学性能先提高后降低,硼酸锌与ATH有协同阻燃抑烟作用,体积电阻率在整个过程中呈下降的趋势.%Influence of aluminium hydroxide (ATH) on properties for poly (vinyl chloride) (PVC) were studied, on which basis the effects of zinc borates (ZB) on mechanical, flame retardant and electrical properties of halogen-free flameretarded poly (vinyl chloride) were researched. The results showed that as ZB content increasing, the mechanical property of halogen-free flame-retarded system increased but declined after, ZB could be used as synergistic flame retardant agents with ATH, and volume resistance presented declining trend with ZB content increasing.

  5. 硼酸锌与蒙脱土对阻燃聚氨酯硬泡抑烟作用的比较%Research on Zinc Borate and Montmorillonite as Smoke Suppression Agent of Rigid Polyurethane Foams

    Institute of Scientific and Technical Information of China (English)

    谢松明; 糜婧; 张广耀; 杜建新; 郝建薇; 王希安

    2015-01-01

    比较了硼酸锌(ZB)与蒙脱土(MMT)在添加了磷酸三(β⁃氯异丙基)酯(TCPP)和可膨胀石墨( EG)的硬质聚氨酯泡沫塑料( RPUF)中的阻燃、抑烟、抑制热释放及CO释放量的差异,使用氧指数、建材烟密度和锥形量热分析进行了表征。研究表明,在RPUF/EG/TCPP 体系中,ZB更有利于降低材料的产烟量和热释放速率,而MMT更有利于降低材料的CO释放量。%The difference of limiting oxygen index ( LOI ) , maximum smoke density ( MSD ) , total smoke pro⁃duction(TSP),heat release rate(HRR) and carbon monoxide production(COP) between zinc borate(ZB) and montmorillonite( MMT) in flame⁃retardant rigid polyurethane foams( RPUF) was compared. The results showed that ZB had the better fire smoke suppression effect than MMT in RPUF/EG/TCPP system, while MMT showed better suppression effect on CO production.

  6. RE{sub 2}B{sub 8}O{sub 15} (RE = La, Pr, Nd). Syntheses of three new rare earth borates isotypic to Ce{sub 2}B{sub 8}O{sub 15}

    Energy Technology Data Exchange (ETDEWEB)

    Glaetzle, Matthias; Hoerder, Gregor J.; Huppertz, Hubert [Innsbruck Univ. (Austria). Inst. fuer Allgemeine, Anorganische und Theoretische Chemie

    2016-08-01

    The rare earth borates RE{sub 2}B{sub 8}O{sub 15} (RE = La, Pr, Nd) were synthesized in a Walker-type multianvil apparatus under conditions of 5.5 GPa and 1100 C. Starting from the corresponding rare earth oxides and boron oxide, the syntheses yielded crystalline products of all new compounds that allowed crystal structure analyses based on single-crystal X-ray diffraction data for La{sub 2}B{sub 8}O{sub 15} and Nd{sub 2}B{sub 8}O{sub 15}. The compound Pr{sub 2}B{sub 8}O{sub 15} could be characterized via X-ray powder diffractometry. The results show that the new compounds crystallize isotypically to Ce{sub 2}B{sub 8}O{sub 15} in the monoclinic space group P2/c. The infrared spectra of RE{sub 2}B{sub 8}O{sub 15} (RE = La, Pr, Nd) have also been studied.

  7. Chemistry of borate in salt lake brine (XXXIV)-- Phase diagram of thermodynamic nonequilibrium state of MgO-B2O3-18%MgCl2-H2O system at 20℃

    Institute of Scientific and Technical Information of China (English)

    GAO; Shiyang; (高世扬); ZHU; Lixia; (朱黎霞); HAO; Zhixian; (郝志显); XIA; Shuping; (夏树屏)

    2002-01-01

    The crystallization processes of hydrated Mg-borates, boric, magnesium hydroxide and Mg-oxychloride from MgO-B2O3-18%MgCl2-H2O supersaturated solution at 20℃ have been studied by kinetic method. The crystallization solid phases were characterized by X-ray powder diffraction, IR spectra, thermal analysis and chemical analysis. The liquid-solid phase diagram of thermodynamic nonequilibrium state has been given. In this phase diagram, there exist eight crystallization fields, boric acid(H3BO3), trigomagneborite(MgO*3B2O3*7.5H2O, MgO*3B2O3*7H2O), hungchaoite(MgO*2B2O3*9H2O), inderite(2MgO*3B2O3*15H2O), chloropinnoite(2MgO*2B2O3*MgCl2*14H2O), magnesium hydroxide(Mg(OH)2) and magnesium oxychloride (5Mg(OH)2*MgCl2*8H2O).

  8. Mixed alkali effect in borate glasses - electron paramagnetic resonance and optical absorption studies in Cu sup 2 sup + doped xNa sub 2 O- (30 - x)K sub 2 O- 70B sub 2 O sub 3 glasses

    CERN Document Server

    Chakradhar, R P S; Rao, J L; Ramakrishna, J

    2003-01-01

    The mixed alkali borate glasses xNa sub 2 O-(30 - x)K sub 2 O-70B sub 2 O sub 3 (5 sup sup 2 B sub 2 sub g) and a weak band on the higher energy side at 22 115 cm sup - sup 1 corresponding to the transition ( sup 2 B sub 1 sub g -> sup 2 E sub g). With x > 5, the higher energy band disappears and the lower energy band shifts slightly to the lower energy side. By correlating the EPR and optical absorption data, the molecular orbital coefficients alpha sup 2 and beta sub 1 sup 2 are evaluated for the different glasses investigated. The values indicate that the in-plane sigma bonding is moderately covalent while the in-plane pi bonding is significantly ionic in nature; these exhibit a minimum with x = 15, showing the MAE. The theoretical values of optical basicity of the glasses have also been evaluated. From optical absorption edges, the optical bandgap energies have been calculated and are found to lie in the range 3.00-3.40 eV. The physical properties of the glasses studied have also been evaluated with respe...

  9. Solvothermal Syntheses and Crystal Structures of Two New Nonmetal Borates: C4H10N2·B6O8(OH)2 and (NH3CH2CH2NH3)B5O8(OH)

    Institute of Scientific and Technical Information of China (English)

    Lü Gui-Qin; YANG Xin; LI Min; SHI Heng-Zhen

    2007-01-01

    Two new borate compounds, C4H10N2·B6O8(OH)2 1 and (NH3CH2CH2NH3)B5O8(OH)2, have been solvothermally synthesized and structurally characterized by single-crystal X-ray diffraction, IR, elemental analysis and thermal analysis. Compound 1 crystallizes in the monoclinic system, space group P21/c, with a = 8.3318(17), b = 6.2118(12), c = 12.479(3) (A), β = 108.96(3)°, V = 610.8(2) (A)3, Mr = 313.02, Z = 2, Dc= 1.702 g/cm3, μ = 0.150 mm-1, F(000) = 320, R = 0.0387and wR = 0.0924. Its layered structure is linked by infinite covalently coordinated neutral sheets with 3,20-membered window system, which are built up from alternative B6O8(OH)2 subunits donated by two piperzazine nitrogen donors. 2 crystallizes in monoclinic, space group Cc, with a =6.7207(13), b = 11.481(2), c = 12.564(3) (A),β = 95.25(3)°, V= 965.4(3) (A)3, Mr= 261.18, Z= 4, Dc=1.797 g/cm3, μ = 0.164 mm-1, F(000) = 536, R = 0.0396 and wR = 0.0752. Its oxoborate structure is generated from the sheets of 3,9-membered boron rings bonded diamine molecules through electrostatic and H-bonding interactions to form a two-dimensional layered network.

  10. Structure-composition relationships and optical properties in cerium-substituted (Sr,Ba)3(Y,La)(BO3)3 borate phosphors

    Energy Technology Data Exchange (ETDEWEB)

    Denault, Kristin A.; Cheng, Zhiyuan; Brgoch, Jakoah; DenBaars, Steven P.; Seshadri, Ram [UCSB

    2013-12-04

    Relationships between the structure and composition, and their influence on the optical properties, of a family of cerium-substituted borate compounds with formula A3RE(BO3)3 (A = Ba, Sr; RE = Y, La) are studied using a combination of high resolution synchrotron X-ray powder diffraction and photoluminescence. Examination of the coordination environment of the Ce3+ active site polyhedra coupled with photoluminescence at 77 K reveal three distinct excitation bands corresponding to Ce3+ located on three distinct crystallographic sites. Comparing the position of these excitation bands with crystal field splitting effects due to changes in polyhedral volumes and distortions suggest an assignment of the three excitation bands. These compounds are efficiently excited by UV light (≈340 nm) with blue emission at a maximum wavelength of 413 nm for Ba3Y(BO3)3:Ce3+,Na+, 422 nm for Sr3Y(BO3)3:Ce3+,Na+, and 440 nm for Sr3La(BO3)3:Ce3+,Na+. The most efficient compound was determined to be Sr3La(BO3)3:Ce3+,Na+ with a quantum yield of 50%.

  11. EPR of Nd{sup 3+} and Er{sup 3+} ions in aluminum borates YAl{sub 3}(BO{sub 3}){sub 4} and EuAl{sub 3}(BO{sub 3}){sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Prokhorov, A.D. [A. A. Galkin Donetsk Physico-Technical Institute, NANU, 83114 Donetsk, R. Luxembourg Street 72 (Ukraine); Prokhorov, A.A., E-mail: prohorov@pr.fti.ac.donetsk.ua [A. A. Galkin Donetsk Physico-Technical Institute, NANU, 83114 Donetsk, R. Luxembourg Street 72 (Ukraine); Chernysh, L.F. [A. A. Galkin Donetsk Physico-Technical Institute, NANU, 83114 Donetsk, R. Luxembourg Street 72 (Ukraine); Aleshkevich, P. [Institute of Physics, PAS, 02-668 Warsaw, Al. Lotnikow 32/46 (Poland); Dyakonov, V. [A. A. Galkin Donetsk Physico-Technical Institute, NANU, 83114 Donetsk, R. Luxembourg Street 72 (Ukraine); Institute of Physics, PAS, 02-668 Warsaw, Al. Lotnikow 32/46 (Poland); Szymczak, H. [Institute of Physics, PAS, 02-668 Warsaw, Al. Lotnikow 32/46 (Poland)

    2013-01-15

    EPR spectra of impurity Nd{sup 3+} and Er{sup 3+} ions in aluminum borates YAl{sub 3}(BO{sub 3}){sub 4} and EuAl{sub 3}(BO{sub 3}){sub 4} have been studied. Dependences of g-factors and linewidth as a function of temperature are established, and the hyperfine interaction constants are determined. Temperature dependences of linewidth of Nd{sup 3+} and Er{sup 3+} ions in both crystals are identical. The absorption line broadening with increasing temperature is caused by strong spin-phonon interaction and is described by the Orbach-Aminov process. Unlike Nd{sup 3+} ion, an anisotropy of temperature dependence of Er{sup 3+} ion linewidth is observed. The relaxation velocity of Er{sup 3+} ions is lower then that of Nd{sup 3+} ions. The anisotropy of spin-lattice relaxation observed for Er{sup 3} ion is due to a large g-factor anisotropy which is larger in the EuAl{sub 3}(BO{sub 3}){sub 4} crystal than in YAl{sub 3}(BO{sub 3}){sub 4} one. A decrease of g-factor of Er{sup 3+} ion in both crystals with increasing temperature is shown to result from spin-phonon interaction. - Highlights: Black-Right-Pointing-Pointer The absorption lines broadening is described by the Orbach-Aminov process. Black-Right-Pointing-Pointer A decrease of g-factor of Er{sup 3+} ion in crystals is caused by spin-phonon interaction. Black-Right-Pointing-Pointer The hyperfine interaction constants are determined. Black-Right-Pointing-Pointer The relaxation velocity of Er{sup 3+} ions is lower than that of Nd{sup 3+} ions.

  12. Preparation of oleic diethanolamide borate and its application in synthetic cutting fluid%油酸二乙醇酰胺硼酸酯的制备及在全合成切削液中的应用

    Institute of Scientific and Technical Information of China (English)

    刘军; 宋扬扬

    2015-01-01

    Oleic diethanolamide was prepared by using oleic acid reacted with diethanolamine in the presence of methylbenzene as water carrying agent, by testing the amine value of reactants at different temperature, appro-priate reaction temperature is 150℃.Oleic diethanolamide borate was prepared by using oleic diethanolamide re-acted with boric acid and n-butyl alcohol at 180℃, which as the main anti-rust agent applied in synthetic cutting fluid. With laminated antirust test for examining the basis, main composition ratio of cutting fluid are optimized by the orthogonal test, products meet the GB/T 6144-2010.%本文以油酸、二乙醇胺反应,甲苯为带水剂制备油酸二乙醇酰胺,通过在不同反应温度下测定反应物胺值,得出适宜的反应温度为150℃.将制备的油酸二乙醇酰胺与硼酸、正丁醇在180℃下反应制备油酸二乙醇酰胺硼酸酯.将其做为主要防锈剂应用于全合成切削液中,以叠片防锈试验为考察依据,通过正交试验优化切削液主要成分配比,产品符合GB/T6144-2010.

  13. Self-discharge suppression of 4.9 V LiNi0.5Mn1.5O4 cathode by using tris(trimethylsilyl)borate as an electrolyte additive

    Science.gov (United States)

    Liao, Xiaolin; Huang, Qiming; Mai, Shaowei; Wang, Xianshu; Xu, Mengqing; Xing, Lidan; Liao, Youhao; Li, Weishan

    2014-12-01

    In this paper, tris(trimethylsilyl)borate (TMSB) is evaluated as an electrolyte additive for the self-discharge suppression of 4.9 V LiNi0.5Mn1.5O4 cathode for lithium ion battery. The effect of TMSB on the surface properties of LiNi0.5Mn1.5O4 is investigated via linear sweep voltammetry (LSV), cyclic voltammetry (CV), chronoamperometry (CA), charge-discharge test, electrochemical impedance spectra (EIS), scanning electron microscopy (SEM), X-ray diffraction (XRD), inductively coupled plasma atomic emission spectrometer (ICP-AES) and Fourier transform infrared spectroscopy (FTIR). It is found that the LiNi0.5Mn1.5O4 cathode charged to 4.9 V (vs. Li/Li+) suffers a serious self-discharge in 1 mol L-1 LiPF6-EC/DMC (1:2, in weight), which can be suppressed effectively by adding 1 wt.% TMSB into the electrolyte. After storage for 20 days, the voltage of the charged cathode decreases from 4.7 to 0.5 V (vs. Li/Li+) in the additive-free electrolyte, while that remains almost unchanged in the TMSB-containing electrolyte. The self-discharge suppression of the charged LiNi0.5Mn1.5O4 cathode results from the preferential oxidation of TMSB and the subsequent formation of a protective solid electrolyte interphase film, which prevents electrolyte decomposition and protects LiNi0.5Mn1.5O4 from destruction.

  14. Identification of Lys49-PLA2 from crude venom of Crotalus atrox as a human neutrophil-calcium modulating protein.

    Science.gov (United States)

    Sultan, Md Tipu; Li, Hong-Mei; Lee, Yong Zu; Lim, Soon Sung; Song, Dong-Keun

    2016-03-01

    We fortuitously observed a human neutrophil intracellular free-calcium concentration ([Ca(2+)]i) increasing activity in the commercially available phosphodiesterase I (PDE I), which is actually dried crude venom of Crotalus atrox. As this activity was not observed with another commercially available pure PDE I, we tried to find out the causative molecule(s) present in 'crude' PDE, and identified Lys49-phospholipase A2 (Lys49-PLA2 or K49-PLA2), a catalytically inactive protein which belongs to the phospholipase A2 family, by activity-driven three HPLC (reverse phase, size exclusion, reverse phase) steps followed by SDS-PAGE and LC-MS/MS. K49-PLA2 induced Ca(2+) infl ux in human neutrophils without any cytotoxic eff ect. Two calcium channel inhibitors, 2-aminoetoxydiphenyl borate (2-APB) (30 µM) and SKF-96365 (20 µM) signifi cantly inhibited K49-PLA2-induced [Ca(2+)]i increase. These results suggest that K49-PLA2 modulates [Ca(2+)]i in human neutrophils via 2-APB- and SKF-96365-sensitive calcium channels without causing membrane disruption.

  15. Preparation and characterization of low hydrated zinc borate Zn6O (OH) (BO3)3%低水合硼酸锌Zn6O(OH)(BO3)3的制备与表征

    Institute of Scientific and Technical Information of China (English)

    王浩宇; 叶俊伟; 周亚蓉; 贡卫涛; 林源; 宁桂玲

    2012-01-01

    以工业硼砂和七水硫酸锌为主要原料,采用沉淀法制备了低水合硼酸锌Zn6O(OH) (BO3)3.使用X射线粉末衍射(XRD)、扫描电子显微镜(SEM)、傅里叶变换红外光谱(FT-IR)、热重分析(TGA)等对产物的结构和形貌进行了表征.考察了反应体系pH、反应温度、反应时间、反应物料配比等因素对产物结构和组成的影响,得出制备Zn6O(OH) (BO3)3的条件:工业硼砂与七水硫酸锌物质的量比为1:1,反应pH为7.5~8.0,反应温度为90℃,反应时间为6h.此条件下产品收率达到83%.%Low hydrated zinc borate Zn6O(OH) (BO3)3 was prepared with industrial borax and zinc sulfate heptahydrate as raw materials by precipitation process.Structure and morphology of the product were characterized by means of X-ray powder diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) ,and thermo gravimetric analysis (TGA) etc.The influences of reaction pH, reaction temperature, reaction time, and mix ratio of reactants on the structure and composition of product were investigated.The conditions of synthesizing Zn6O (OH) (BO3)3 were obtained as follows: amount-of-substance ratio of industrial borax to zinc sulfate heptahydrate was 1:1, reaction pH was at 7.5~8.0, reaction temperature was 90 ℃, and reaction time was 6 h.The yield of the product was 83% under those condtions.

  16. Modification of intracellular free calcium in cultured A10 vascular smooth muscle cells by exogenous phosphatidic acid.

    Science.gov (United States)

    Bhugra, Praveen; Xu, Yan-Jun; Rathi, Satyajeet; Dhalla, Naranjan S

    2003-06-15

    Exogenous phosphatidic acid (PA) was observed to produce a concentration-dependent increase in [Ca(2+)](i) in cultured A10 vascular smooth muscle cells. Preincubation of cells with sarcoplasmic reticulum Ca(2+)-ATPase inhibitors (cyclopiazonic acid and thapsigargin), a phospholipase C inhibitor (2-nitro-4-carboxyphenyl-N,N-diphenylcarbamate), inositol 1,4,5-trisphosphate receptor antagonists (2-aminoethoxydiphenyl borate and xestospongin), and an activator of protein kinase C (PKC) (phorbol 12-myristate 13-acetate) depressed the PA-evoked increase in [Ca(2+)](i). Although EGTA, an extracellular Ca(2+) chelator, decreased the PA-induced increase in [Ca(2+)](i), sarcolemmal Ca(2+)-channel blockers (verapamil or diltiazem) did not alter the action of PA. On the other hand, inhibitors of PKC (bisindolylmaleimide I) and G(i)-protein (pertussis toxin) potentiated the increase in [Ca(2+)](i) evoked by PA significantly. These results suggest that the PA-induced increase in [Ca(2+)](i) in vascular smooth muscle cells may occur upon the activation of phospholipase C and the subsequent release of Ca(2+) from the inositol 1,4,5-trisphosphate-sensitive Ca(2+) pool in the sarcoplasmic reticulum. This action of PA may be mediated through the involvement of PKC. PMID:12787890

  17. Loss of responsiveness of circular smooth muscle cells from the guinea pig ileum is associated with changes in gap junction coupling.

    Science.gov (United States)

    Carbone, Simona E; Wattchow, David A; Spencer, Nick J; Brookes, Simon J H

    2012-06-15

    Gap junction coupling and neuromuscular transmission to smooth muscle were studied in the first 4 h after preparations were set up in vitro. Intracellular recordings were made from smooth muscle cells of guinea pig ileum. Fast inhibitory junction potentials (IJPs) were small (1.3 ± 1.0 mV) in the first 30 min but increased significantly over the first 120 min to 15.8 ± 0.9 mV (n = 12, P potentials were also observed. During the same period, resting membrane potential depolarized from -58.8 ± 1.4 to -47.2 ± 0.4 mV (n = 12, P potentials, increased input resistance, and reduced dye coupling. Local application of ATP (10 mM) mimicked IJPs and showed comparable increases in amplitude over the first 120 min; carbenoxolone and 2-aminoethoxydiphenyl borate significantly reduced ATP-evoked hyperpolarizations in coupled cells. In contrast, synaptic transmission between myenteric neurons was not suppressed during the first 30 min. Gap junction coupling between circular smooth muscle cells in isolated preparations was initially disrupted but recovered over the next 120 min to a steady level. This was associated with potent effects on neuromuscular transmission and responses to exogenous ATP.

  18. Activation of TRPV2 negatively regulates the differentiation of mouse brown adipocytes.

    Science.gov (United States)

    Sun, Wuping; Uchida, Kunitoshi; Takahashi, Nobuyuki; Iwata, Yuko; Wakabayashi, Shigeo; Goto, Tsuyoshi; Kawada, Teruo; Tominaga, Makoto

    2016-09-01

    Transient receptor potential vanilloid 2 (TRPV2) acts as a Ca(2+)-permeable non-selective cation channel that has been reported to be sensitive to temperature, mechanical force, and some chemicals. We recently showed that TRPV2 is critical for maintenance of the thermogenic function of brown adipose tissue in mice. However, the involvement of TRPV2 in the differentiation of brown adipocytes remains unexplored. We found that the expression of TRPV2 was dramatically increased during the differentiation of brown adipocytes. Non-selective TRPV2 agonists (2-aminoethoxydiphenyl borate and lysophosphatidylcholine) inhibited the differentiation of brown adipocytes in a dose-dependent manner during the early stage of differentiation of brown adipocytes. The inhibition was rescued by a TRPV2-selective antagonist, SKF96365 (SKF). Mechanical force, which activates TRPV2, also inhibited the differentiation of brown adipocytes in a strength-dependent manner, and the effect was reversed by SKF. In addition, the inhibition of adipocyte differentiation by either TRPV2 ligand or mechanical stimulation was significantly smaller in the cells from TRPV2KO mice. Moreover, calcineurin inhibitors, cyclosporine A and FK506, partially reversed TRPV2 activation-induced inhibition of brown adipocyte differentiation. Thus, we conclude that TRPV2 might be involved in the modulation of brown adipocyte differentiation partially via a calcineurin pathway. PMID:27318696

  19. Modification of intracellular free calcium in cultured A10 vascular smooth muscle cells by exogenous phosphatidic acid.

    Science.gov (United States)

    Bhugra, Praveen; Xu, Yan-Jun; Rathi, Satyajeet; Dhalla, Naranjan S

    2003-06-15

    Exogenous phosphatidic acid (PA) was observed to produce a concentration-dependent increase in [Ca(2+)](i) in cultured A10 vascular smooth muscle cells. Preincubation of cells with sarcoplasmic reticulum Ca(2+)-ATPase inhibitors (cyclopiazonic acid and thapsigargin), a phospholipase C inhibitor (2-nitro-4-carboxyphenyl-N,N-diphenylcarbamate), inositol 1,4,5-trisphosphate receptor antagonists (2-aminoethoxydiphenyl borate and xestospongin), and an activator of protein kinase C (PKC) (phorbol 12-myristate 13-acetate) depressed the PA-evoked increase in [Ca(2+)](i). Although EGTA, an extracellular Ca(2+) chelator, decreased the PA-induced increase in [Ca(2+)](i), sarcolemmal Ca(2+)-channel blockers (verapamil or diltiazem) did not alter the action of PA. On the other hand, inhibitors of PKC (bisindolylmaleimide I) and G(i)-protein (pertussis toxin) potentiated the increase in [Ca(2+)](i) evoked by PA significantly. These results suggest that the PA-induced increase in [Ca(2+)](i) in vascular smooth muscle cells may occur upon the activation of phospholipase C and the subsequent release of Ca(2+) from the inositol 1,4,5-trisphosphate-sensitive Ca(2+) pool in the sarcoplasmic reticulum. This action of PA may be mediated through the involvement of PKC.

  20. Zinc-induced neurotoxicity mediated by transient receptor potential melastatin 7 channels.

    Science.gov (United States)

    Inoue, Koichi; Branigan, Deborah; Xiong, Zhi-Gang

    2010-03-01

    Transient receptor potential melastatin 7 (TRPM7) channels are novel Ca(2+)-permeable non-selective cation channels ubiquitously expressed. Activation of TRPM7 channels has been shown to be involved in cellular Mg(2+) homeostasis, diseases caused by abnormal magnesium absorption, and in Ca(2+)-mediated neuronal injury under ischemic conditions. Here we show strong evidence suggesting that TRPM7 channels also play an important role in cellular Zn(2+) homeostasis and in Zn(2+)-mediated neuronal injury. Using a combination of fluorescent Zn(2+) imaging, small interfering RNA, pharmacological analysis, and cell injury assays, we show that activation of TRPM7 channels augmented Zn(2+)-induced injury of cultured mouse cortical neurons. The Zn(2+)-mediated neurotoxicity was inhibited by nonspecific TRPM7 blockers Gd(3+) or 2-aminoethoxydiphenyl borate, and by knockdown of TRPM7 channels with small interfering RNA. In addition, Zn(2+)-mediated neuronal injury under oxygen-glucose deprivation conditions was also diminished by silencing TRPM7. Furthermore, we show that overexpression of TRPM7 channels in HEK293 cells increased intracellular Zn(2+) accumulation and Zn(2+)-induced cell injury, while silencing TRPM7 by small interfering RNA attenuated the Zn(2+)-mediated cell toxicity. Thus, TRPM7 channels may represent a novel target for neurological disorders where Zn(2+) toxicity plays an important role. PMID:20048154