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Sample records for 2-aminoethoxydiphenyl borate 2-apb

  1. Effects of boric acid and 2-aminoethoxydiphenyl borate on necrotizing enterocolitis.

    Science.gov (United States)

    Yazıcı, Selçuk; Akşit, Hasan; Korkut, Oğuzhan; Sunay, Bahar; Çelik, Tanju

    2014-01-01

    The aim was to study the effects of boric acid (BA) and 2-aminoethoxydiphenyl borate (2-APB) on oxidative stress and inflammation in an experimental necrotizing enterocolitis (NEC) rat model. Experimental NEC was induced in 40 newborn Sprague-Dawley rats by asphyxia and hypothermia applied in 3 consecutive days. Rats were subdivided into 4 subgroups as NEC, NEC+BA, NEC+2-APB, and controls. BA and 2-APB were applied daily before the procedure. Serum total antioxidant status, superoxide dismutase (SOD), tumor necrosis factor (TNF)-α, interleukin (IL)-6, and erythrocyte glutathione (GSH) levels were measured. Pathological changes for NEC in intestinal architecture were evaluated by a grading system. Pretreatment with BA and 2-APB resulted in a decrease in NEC incidence. In all of the NEC groups, decreased serum levels of GSH and SOD were measured. Boron limited GSH consumption but had no effect on SOD levels. Total antioxidant status levels were not statistically different among groups. In our experimental NEC model, BA, but not 2-APB, prevented the increase of TNF-α. Pretreatment with BA and 2-APB downregulated the activity levels of IL-6 in NEC. In the experimental NEC model, BA and 2-APB partly prevent NEC formation, modulate the oxidative stress parameters, bring a significant decrease in GSH consumption, and enhance the antioxidant defense mechanism, but have no effect on total antioxidant status. BA inhibits the hypoxia and hypothermia-induced increase in both IL-6 and TNF-a, but 2-APB only in IL-6. Boron may be beneficial in preventing NEC.

  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)

    Wu, Ching-Ying; Hsu, Wen-Li; Wang, Chun-Hsiung; 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.

  3. 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

  4. 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.

  5. 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

  6. 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

  7. "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)

  8. 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.

  9. "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)

  10. 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"

  11. 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"

  12. 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

  13. 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.

  14. 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

  15. 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.

  16. 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

  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. 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.

  19. 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.

  20. Arecoline excites the contraction of distal colonic smooth muscle strips in rats via the M3 receptor-extracellular Ca2+ influx - Ca2+ store release pathway.

    Science.gov (United States)

    Li, Chuan-Bao; Yang, Xiao; Tang, Wen-Bo; Liu, Chuan-Yong; Xie, Dong-Ping

    2010-04-01

    Areca is a Chinese herbal medicine that is widely used for constipation. However the mechanisms of its action are not clear. We investigated the effects of arecoline, the most active component of areca, on the motility of rat distal colonic smooth muscle strips. In longitudinal muscle of distal colon (LMDC) and circular muscle of distal colon (CMDC), arecoline increased the contraction in a dose-dependent manner. Tetrodotoxin (TTX) did not inhibit the effects of arecoline. The contractile response to arecoline was completely antagonized by atropine. 4-Diphenylacetoxy-N-methylpiperidine methiodide (4-DAMP) strongly depressed the response to arecoline, but gallamine and methoctramine did not. Nifedipine, 2-aminoethoxydiphenyl borate (2-APB), and Ca2+-free Krebs solution with EGTA partly inhibited the effects of arecoline. The sum of Ca2+-free Krebs solution, EGTA, and 2-APB completely inhibited the effects of arecoline. The results show that arecoline stimulates distal colonic contraction in rats via the muscarinic (M3) receptor - extracellular Ca2+ influx - Ca2+ store release pathway. It is likely that the action of areca in relieving constipation is due to its stimulation of muscle contraction.

  1. Borate in mummification salts and bones from Pharaonic Egypt.

    Science.gov (United States)

    Kaup, Yoka; Schmid, Mirjam; Middleton, Andrew; Weser, Ulrich

    2003-03-01

    Mummification processes in Pharaonic Egypt were successful using sodium salts. Quite frequently sodium concentrations in mummified bones ranged from 300 to 4000 micromol/g. In the search for an effective inorganic conservation compound our choice fell on boric acid. The possible presence of borate in mummification salts used in Pharaonic Egypt was of special interest both historically and biochemically. In two salt samples, one from the embalming material of Tutankhamen (18th dynasty, 1336-1327 BC) and the second from Deir el-Bahari (25th dynasty, 700-600 BC) borate was found, amounting to 2.1+/-0.2 and 3.9+/-0.1 micromol/g, respectively. In five of the examined bone fragments from the Junker excavation at Giza (Old Kingdom) similar borate concentrations i.e., 1.2 micromol borate/g bone were seen. It must be emphasized that the usual borate content of contemporary autopsy is far below the detection limit. The elevated borate content in both mummification salt and ancient bone samples support the suggestion that borate-containing salt had been used. There is a striking correlation of both borate concentration and alkaline phosphatase activity. When both sodium salts and borate were essentially absent no activity at all was detectable. With increasing borate concentrations the enzyme activity rises significantly. Attributable to the distinct biochemistry of the tetrahydroxyborate anion it was of interest whether or not borate may stabilize alkaline phosphatase, an important and richly abundant bone enzyme. This enzyme was chosen, as it is known to survive more than 4000 years of mummification. In the presence of borate oligomeric species of this zinc-magnesium-glycoprotein at 400,000 Da became detectable. Attributable to this borate-dependent stabilization of the enzyme molecule a significant temperature resistant increase of the enzymic activity was measured in the presence of up to 2.5 mM borate.

  2. Structural relaxation in bismuth and lead borate glasses

    Science.gov (United States)

    Bajaj, Anu; Khanna, Atul

    2012-06-01

    Bismuth and lead borate glasses were prepared by melt quench technique. Effects of heat treatment on the density and thermal properties of bismuth and lead borate glasses was studied by annealing the glasses at 350°C for 500 h. Density of all bismuth borate glasses increases by about 0.5-0.7% with annealing and the effect is more in glasses with higher Bi2O3 concentration. In bismuth borate glasses with 50 and 55 mol % Bi2O3 we found an extraordinary large increase of Tg by 15°C after thermal annealing. All bismuth borate glasses remained completely clear and transparent on annealing. Lead borate glasses become cloudy on thermal annealing indicating occurrence of phase separation in these glasses.

  3. Interfacial reactions between titanium and borate glass

    Energy Technology Data Exchange (ETDEWEB)

    Brow, R.K. [Sandia National Labs., Albuquerque, NM (United States); Saha, S.K.; Goldstein, J.I. [Lehigh Univ., Bethlehem, PA (United States). Dept. of Materials Science

    1992-12-31

    Interfacial reactions between melts of several borate glasses and titanium have been investigated by analytical scanning electron microscopy (SEM) and x-ray photoelectron spectroscopy (XPS). A thin titanium boride interfacial layer is detected by XPS after short (30 minutes) thermal treatments. ASEM analyses after longer thermal treatments (8--120 hours) reveal boron-rich interfacial layers and boride precipitates in the Ti side of the interface.

  4. The Synthesis and Physical Properties of Magnesium Borate Mineral of Admontite Synthesized from Sodium Borates

    Directory of Open Access Journals (Sweden)

    Azmi Seyhun Kipcak

    2014-01-01

    Full Text Available Magnesium borates are significant compounds due to their advanced mechanical and thermal durability properties. This group of minerals can be used in ceramic industry, in detergent industry, and as neutron shielding material, phosphor of thermoluminescence by dint of their extraordinary specialties. In the present study, the synthesis of magnesium borate via hydrothermal method from sodium borates and physical properties of synthesized magnesium borate minerals were investigated. The characterization of the products was carried out by X-ray diffraction (XRD, Fourier transform infrared (FT-IR and Raman spectroscopies, and differential thermal analysis and thermal gravimetry (DTA/TG. The surface morphology was examined by scanning electron microscopy (SEM. B2O3 content was determined through titration. The electrical resistivity/conductivity properties of products were measured by Picoammeter Voltage Source. UV-vis spectrometer was used to investigate optical absorption characteristics of synthesized minerals in the range 200–1000 nm at room temperature. XRD results identified the synthesized borate minerals as admontite [MgO(B2O33·7(H2O] with code number “01-076-0540” and mcallisterite [Mg2(B6O7(OH62·9(H2O] with code number “01-070-1902.” The FT-IR and Raman spectra of the obtained samples were similar with characteristic magnesium borate bands. The investigation of the SEM images remarked that both nano- and microscale minerals were produced. The reaction yields were between 75.1 and 98.7%.

  5. Gypenosides Induce Apoptosis by Ca2+ Overload Mediated by Endoplasmic-Reticulum and Store-Operated Ca2+ Channels in Human Hepatoma Cells

    Science.gov (United States)

    Sun, Da-Peng; Li, Xiao-Xi; Liu, Xin-Li; Zhao, Dan; Qiu, Feng-Qi; Li, Yan

    2013-01-01

    Abstract Gypenosides (Gyps) are triterpenoid saponins contained in an extract from Gynostemma pentaphyllum Makino and reported to induce apoptosis in human hepatoma cells through Ca2+-implicated endoplasmic reticulum (ER) stress and mitochondria-dependent pathways. The mechanism underlying the Gyp-increased intracellular Ca2+ concentration ([Ca2+]i) is unclear. Here, we examined Gyp-induced necrosis and apoptosis in human hepatoma HepG2 cells. Gyp-induced apoptotic cell death was accompanied by a sustained increase in [Ca2+]i level. Gyp-increased [Ca2+]i level was partly inhibited by removal of extracellular Ca2+ by Ca2+ chelator EGTA, store-operated Ca2+ channel (SOC) inhibitor 2- aminoethoxydiphenyl borate (2-APB), and ER Ca2+-release-antagonist 3,4,5-trimethoxybenzoic acid 8-(diethylamino) octyl ester (TMB-8). The strongest inhibitory effect was observed with TMB-8. EGTA, 2-APB, and TMB-8 also protected against Gyp-induced apoptosis in HepG2 cells. The combination of 2-APB and TMB-8 almost completely abolished the Gyp-induced Ca2+ response and apoptosis. In contrast, the sarco/endoplasmic-reticulum-Ca2+-ATPase (SERCA) inhibitor thapsigargin slightly elevated Gyp-induced [Ca2+]i increase and apoptosis in HepG2 cells. Exposure to 300 μg/mL Gyp for 24 hours upregulated protein levels of inositol 1,4,5-trisphosphate receptor and SOC and downregulated that of SERCA for at least 72 hours. Thus, Gyp-induced increase in [Ca2+]i level and consequent apoptosis in HepG2 cells may be mainly due to enhanced Ca2+ release from ER stores and increased store-operated Ca2+ entry. PMID:25310348

  6. Allyl borates: a novel class of polyhomologation initiators

    KAUST Repository

    Wang, De

    2016-12-24

    Allyl borates, a new class of monofunctional polyhomologation initiators, are reported. These monofunctional initiators are less sensitive and more effective towards polymethylene-based architectures. As an example, the synthesis of α-vinyl-ω-hydroxypolymethylenes is given. By designing/synthesizing different allylic borate initiators, and using 1H and 11B NMR spectroscopy, the initiation mechanism was elucidated.

  7. Structure and Properties of Compressed Borate Glasses

    DEFF Research Database (Denmark)

    Smedskjær, Morten Mattrup; Bauer, U.; Behrens, H.;

    in a series of borate glasses. Upon isostatic compression, NMR experiments show that the fraction of tetrahedral boron increases, leading to an overall decrease of the molar volume of the network. We correlate these structural changes with changes in elastic moduli from Brillouin scattering experiments......While the influence of thermal history on the structure and properties of glasses has been thoroughly studied in the past century, the influence of pressure history has received considerably less attention. In this study, we investigate the pressure-induced changes in structure and properties...

  8. Friction and wear performances of borates and lanthanum chloride in water

    Institute of Scientific and Technical Information of China (English)

    CHEN Boshui; FANG Jianhua; WANG Jiu; LI Jia; LOU Fang

    2008-01-01

    The antiwear and friction-reducing performances of sodium borate, potassium borate and lanthanum chloride in water were evaluated on a four-ball friction tester. The topographies, element distribution and chemical characteristics of the worn surfaces were investigated by scanning electron microscope (SEM), energy dispersion of X-ray (EDX) and X-ray photoelectron spectroscope (XPS). The results indicated that sodium borate, potassium borate and lanthanum chloride increased extreme pressure, antiwear and friction-reducing capacities of water to a certain extent, of which potassium borate was the best candidate. Combination of lanthanum chloride with sodium borate and potassium borate respectively further improved antiwear and friction-reducing capacities. Scratches of worn surfaces lubricated with water containing borates and lanthanum chloride were less severe than those lubricated with water containing borates alone. A tribochemical film mainly composed of oxides of lanthanum, boron and iron reduced friction and wear for water lubricant formulated with both borates and lanthanum chloride.

  9. Rare earth separations by selective borate crystallization

    Science.gov (United States)

    Yin, Xuemiao; Wang, Yaxing; Bai, Xiaojing; Wang, Yumin; Chen, Lanhua; Xiao, Chengliang; Diwu, Juan; Du, Shiyu; Chai, Zhifang; Albrecht-Schmitt, Thomas E.; Wang, Shuao

    2017-03-01

    Lanthanides possess similar chemical properties rendering their separation from one another a challenge of fundamental chemical and global importance given their incorporation into many advanced technologies. New separation strategies combining green chemistry with low cost and high efficiency remain highly desirable. We demonstrate that the subtle bonding differences among trivalent lanthanides can be amplified during the crystallization of borates, providing chemical recognition of specific lanthanides that originates from Ln3+ coordination alterations, borate polymerization diversity and soft ligand coordination selectivity. Six distinct phases are obtained under identical reaction conditions across lanthanide series, further leading to an efficient and cost-effective separation strategy via selective crystallization. As proof of concept, Nd/Sm and Nd/Dy are used as binary models to demonstrate solid/aqueous and solid/solid separation processes. Controlling the reaction kinetics gives rise to enhanced separation efficiency of Nd/Sm system and a one-step quantitative separation of Nd/Dy with the aid of selective density-based flotation.

  10. Devitrification properties of lead borate glasses

    Science.gov (United States)

    Bajaj, Anu; Khanna, Atul; Krishnan, K.; Aggarwal, Suresh K.

    2013-06-01

    Lead borate glasses containing 30 to 60 mol% PbO were prepared by melt quenching technique and devitrified by long duration heat treament in the supercooled region. Glasses crystallized on heating above their glass transition temperature, and the crystalline phases produced on devitrification were characterized by XRD and DSC analyses. Glass with 30 mol% PbO slowly formed a solid solution of Pb6B10O21 and Pb5B8O17 crystalline phases, while glasses with 40 and 50 mol% PbO formed a mixture of Pb6B10O21, Pb5B8O17 and the remanent glassy phase. Glasses with higher PbO concentration of 56 to 60 mol% devitrified completely and produced only Pb5B8O17 crystalline phase. Lead borate glasses with PbO concentration of 40 to 50 mol% showed maximum thermal stability against devitrification, the ease of crystallization of glasses was correlated with the fraction of tetrahedral borons in them.

  11. [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.

  12. Towards modeling gadolinium-lead-borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Rada, S., E-mail: Simona.Rada@phys.utcluj.ro [Department of Physics, Technical University of Cluj-Napoca, 400641 Cluj-Napoca (Romania); Ristoiu, T. [Department of Physics, Technical University of Cluj-Napoca, 400641 Cluj-Napoca (Romania); Rada, M. [Department of Mechatronic, Technical University of Cluj-Napoca, 400641 Cluj-Napoca (Romania); Coroiu, I. [Department of Physics, Technical University of Cluj-Napoca, 400641 Cluj-Napoca (Romania); Maties, V. [Department of Mechatronic, Technical University of Cluj-Napoca, 400641 Cluj-Napoca (Romania); Culea, E. [Department of Physics, Technical University of Cluj-Napoca, 400641 Cluj-Napoca (Romania)

    2010-01-15

    Infrared spectra of gadolinium-lead-borate glasses of the xGd{sub 2}O{sub 3}.(100 - x)[3B{sub 2}O{sub 3}.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 xGd{sub 2}O{sub 3}.(1 - x)[3B{sub 2}O{sub 3}.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 Gd{sub 2}O{sub 3} 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 [BO{sub 4}] units into trigonal [BO{sub 3}] units. Then, gadolinium ions have affinity towards [BO{sub 3}] structural units which contain non-bridging oxygens necessary for the charge compensation because the more electronegative [BO{sub 3}] 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 3B{sub 2}O{sub 3}.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.

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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.

  18. 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.

  19. Borate minerals and origin of the RNA world.

    Science.gov (United States)

    Grew, Edward S; Bada, Jeffrey L; Hazen, Robert M

    2011-08-01

    The RNA World is generally thought to have been an important link between purely prebiotic (>3.7 Ga) chemistry and modern DNA/protein biochemistry. One concern about the RNA World hypothesis is the geochemical stability of ribose, the sugar moiety of RNA. Prebiotic stabilization of ribose by solutions associated with borate minerals, notably colemanite, ulexite, and kernite, has been proposed as one resolution to this difficulty. However, a critical unresolved issue is whether borate minerals existed in sufficient quantities on the primitive Earth, especially in the period when prebiotic synthesis processes leading to RNA took place. Although the oldest reported colemanite and ulexite are 330 Ma, and the oldest reported kernite, 19 Ma, boron isotope data and geologic context are consistent with an evaporitic borate precursor to 2400-2100 Ma borate deposits in the Liaoning and Jilin Provinces, China, as well as to tourmaline-group minerals at 3300-3450 Ma in the Barberton belt, South Africa. The oldest boron minerals for which the age of crystallization could be determined are the metamorphic tourmaline species schorl and dravite in the Isua complex (metamorphism between ca. 3650 and ca. 3600 Ma). Whether borates such as colemanite, ulexite and kernite were present in the Hadean (>4000 Ma) at the critical juncture when prebiotic molecules such as ribose required stabilization depends on whether a granitic continental crust had yet differentiated, because in its absence we see no means for boron to be sufficiently concentrated for borates to be precipitated.

  20. Nuclear chemistry model of borated fuel crud

    Energy Technology Data Exchange (ETDEWEB)

    Sawicki, J.A. [Atomic Energy of Canada Ltd., Chalk River, ON (Canada)

    2002-07-01

    Fuel crud deposits on Callaway Cycle 9 once-burnt high-axial offset anomaly (AOA {approx} -15%) feed assemblies revealed a complex 4-phase matted-layered morphology of a new type that is uncommon in pressurized water reactors [1-3]. The up to 140-{open_square}m-thick crud flakes consisted predominantly of insoluble needle-like particles of Ni-Fe oxy-borate Ni{sub 2}FeBO{sub 5} (bonaccordite) and granular precipitates of m-ZrO{sub 2} (baddeleyite), along with nickel oxide NiO (bunsenite) and minor amount of nickel ferrite NiFe{sub 2}O{sub 4} (trevorite). Furthermore, boron in crud flakes showed that the concentration of {sup 10}B had depleted to 10.2{+-}0.2%, as compared to its 20% natural isotopic abundance and its 17% end-of-cycle abundance in bulk coolant. The form and depth distribution of Ni{sub 2}FeBO{sub 5} and m-ZrO{sub 2} precipitates, as well as substantial {sup 10}B burn-up, point to a strongly alkaline environment at the clad surface of the high-duty fuel rods. This paper extends a nuclear chemistry model of heavily borated fuel crud deposits. The paper shows that the local nuclear heat and lithium buildup from {sup 10}B(n,{open_square}){sup 7}Li reactions may help to create hydrothermal and chemical conditions within the crud layer in favor of Ni{sub 2}FeBO{sub 5} formation and a ZrO{sub 2} dissolution-reprecipitation mechanism. Consistent with the model, the hydrothermal formation of Ni{sub 2}FeBO{sub 5} needles was recently proved to be possible in laboratory tests with aqueous NiO-Fe{sub 2}O{sub 3}-H{sub 3}BO{sub 3}-LiOH slurries, at temperatures only slightly exceeding 400 C. (author)

  1. Interaction of Lamb Waves with Domain Walls in an Iron Borate Plate

    Directory of Open Access Journals (Sweden)

    E.A. Zhukov

    2015-12-01

    Full Text Available This work presents the calculation results of the Lamb wave spectra in a plate of iron borate. Experimental data on how flexural vibrations in a borate plate influence its domain structure are provided.

  2. THz spectra of five borates crystals

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Terahertz spectral responses have been studied for five borate crystals Na5[B2P3O13](NBP),Zn3BPO (ZBP),SrB4O7(SBO),Na3La9O3(BO3)8(NLBO)and PbB4O7(PBO).It is found that the samples had good transmission in 0.25-1.5 THz region.Both SBO and NLBO have an absorption coefficient less than 10cm-1.Among them,SBO has not only the smallest absorption coefficient but also a very flat dispersion in the frequency region under investigation.Distinct resonance absorption peaks are observed for ZBP at v1=1.4 THz,v2=2.0 THz and SBO at v=2.4 THz.In the spectrum of PBO,two 8bnormal dispersions appear in the frequency regions 1.44-1.74 and 2.2-2.5 THz.The absorption coetficients and refraction indices of the five crystals are extracted from the THz time-domain(THz-TDB)spectra in 0.25-2.5 THz region.The properties and origins of the spectral responses are addressed.

  3. The tribological performance and tribochemical analysis of novel borate esters as lubricant additives in rapeseed oil

    NARCIS (Netherlands)

    Yan, J.; Zeng, X.; Heide, van der E.; Ren, T.

    2014-01-01

    Two novel borate esters, tris (4-dodecylphenyl) borate and 2-(2-(4-dodecylphenoxy)-1, 3, 6, 2-dioxazaborocan-6-yl) ethanol were synthesized and applied as anti-wear and extreme pressure additives in rapeseed oil. The borate esters possess high anti-wear and extreme pressure properties. XANES and XPS

  4. 76 FR 74831 - Aging Management of Stainless Steel Structures and Components in Treated Borated Water

    Science.gov (United States)

    2011-12-01

    ... COMMISSION Aging Management of Stainless Steel Structures and Components in Treated Borated Water AGENCY...- ISG-2011-01, ``Aging Management of Stainless Steel Structures and Components in Treated Borated Water... management of stainless steel structures and components exposed to treated borated water. In response to...

  5. 21 CFR 872.3400 - Karaya and sodium borate with or without acacia denture adhesive.

    Science.gov (United States)

    2010-04-01

    ... denture adhesive. 872.3400 Section 872.3400 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... and sodium borate with or without acacia denture adhesive. (a) Identification. A karaya and sodium borate with or without acacia denture adhesive is a device composed of karaya and sodium borate with...

  6. Barium-borate-flyash glasses: As radiation shielding materials

    Science.gov (United States)

    Singh, Sukhpal; Kumar, Ashok; Singh, Devinder; Thind, Kulwant Singh; Mudahar, Gurmel S.

    2008-01-01

    The attenuation coefficients of barium-borate-flyash glasses have been measured for γ-ray photon energies of 356, 662, 1173 and 1332 keV using narrow beam transmission geometry. The photon beam was highly collimated and overall scatter acceptance angle was less than 3°. Our results have an uncertainty of less than 3%. These coefficients were then used to obtain the values of mean free path (mfp), effective atomic number and electron density. Good agreements have been observed between experimental and theoretical values of these parameters. From the studies of the obtained results it is reported here that from the shielding point of view the barium-borate-flyash glasses are better shields to γ-radiations in comparison to the standard radiation shielding concretes and also to the ordinary barium-borate glasses.

  7. Optical properties of neodymium doped lanthanum scandium borate

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Won Kweon [Hanseo University, Seosan (Korea, Republic of); Kim, Tae Hoon; Yu, Young Moon [Korea Photonics Technology Institute, Kwangju (Korea, Republic of)

    2001-11-15

    Optical characteristics of neodymium doped lanthanium scandium borate, newly developed crystal, was investigated. Technical description of crystal growth and its dependence on optical property were investigated with comparison to other laser crystals. Its potential as commercial laser crystal for microchip laser fabrication was observed with fundamental lasing experiments. It was possible for lanthanium scandium borate to be highly doped with neodymium ion without crystal defect, and it is an advantage for microchip laser host material. The laser operation was investigated in the fundamental with microchip system.

  8. Glass-Forming Ability of Soda Lime Borate Liquids

    DEFF Research Database (Denmark)

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

    2012-01-01

    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. We have also discovered and clarified a striking thermal history dependence of the glass stability...

  9. 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.

  10. The Mechanism of Ca(2+) Movement in the Involvement of Baicalein-Induced Cytotoxicity in ZR-75-1 Human Breast Cancer Cells.

    Science.gov (United States)

    Chang, Hong-Tai; Chou, Chiang-Ting; Kuo, Daih-Huang; Shieh, Pochuen; Jan, Chung-Ren; Liang, Wei-Zhe

    2015-07-24

    Baicalein (5,6,7-trihydroxyflavone) (1) has been found to be active against a wide variety of cancer cells. However, the molecular mechanism underlying the effects of 1 on the induction of Ca(2+) movement and cytotoxicity in human breast cancer cells is unknown. This study examined the relationship between 1-induced Ca(2+) signaling and cytotoxicity in ZR-75-1 human breast cancer cells. The in vitro investigations reported herein produced the following results: (i) Compound 1 increased intracellular Ca(2+) concentration ([Ca(2+)]i) in a concentration-dependent manner. The signal was decreased by approximately 50% by removal of extracellular Ca(2+). (ii) Compound 1-triggered [Ca(2+)]i increases were significantly suppressed by store-operated Ca(2+) channel blockers 2-aminoethoxydiphenyl borate (2-APB) and the PKC inhibitor GF109203X. (iii) In Ca(2+)-free medium, compound 1-induced [Ca(2+)]i increases were also inhibited by GF109203X. Furthermore, pretreatment with the endoplasmic reticulum Ca(2+) pump inhibitor thapsigargin (TG) or 2,5-ditert-butylhydroquinone (BHQ) abolished 1-induced [Ca(2+)]i increases. Inhibition of phospholipase C (PLC) with U73122 abolished 1-induced [Ca(2+)]i increases. (iv) Compound 1 (20-40 μM) caused cytotoxicity, increased reactive oxygen species (ROS) production, and activated caspase-9/caspase-3. Furthermore, compound 1-induced apoptosis was significantly inhibited by prechelating cytosolic Ca(2+) with BAPTA-AM (1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid acetoxymethyl ester) or by decreasing ROS with the antioxidant NAC (N-acetylcysteine). Together, baicalein (1) induced a [Ca(2+)]i increase by inducing PLC-dependent Ca(2+) release from the endoplasmic reticulum and Ca(2+) entry via PKC-dependent, 2-APB-sensitive store-operated Ca(2+) channels. Moreover, baicalein (1) induced Ca(2+)-associated apoptosis involved ROS production in ZR-75-1 cells.

  11. Regulation of autophagy in cardiomyocytes by Ins(1,4,5)P(3) and IP(3)-receptors.

    Science.gov (United States)

    Wong, Albert; Grubb, David R; Cooley, Nicola; Luo, Jieting; Woodcock, Elizabeth A

    2013-01-01

    Autophagy is a process that removes damaged proteins and organelles and is of particular importance in terminally differentiated cells such as cardiomyocytes, where it has primarily a protective role. We investigated the involvement of inositol(1,4,5)trisphosphate (Ins(1,4,5)P(3)) and its receptors in autophagic responses in neonatal rat ventricular myocytes (NRVM). Treatment with the IP(3)-receptor (IP(3)-R) antagonist 2-aminoethoxydiphenyl borate (2-APB) at 5 or 20 μmol/L resulted in an increase in autophagosome content, defined as puncta labeled by antibody to microtubule associated light chain 3 (LC3). 2-APB also increased autophagic flux, indicated by heightened LC3II accumulation, which was further enhanced by bafilomycin (10nmol/L). Expression of Ins(1,4,5)P(3) 5-phosphatase (IP(3)-5-Pase) to deplete Ins(1,4,5)P(3) also increased LC3-labeled puncta and LC3II content, suggesting that Ins(1,4,5)P(3) inhibits autophagy. The IP(3)-R can act as an inhibitory scaffold sequestering the autophagic effector, beclin-1 to its ligand binding domain (LBD). Expression of GFP-IP(3)-R-LBD inhibited autophagic signaling and furthermore, beclin-1 co-immunoprecipitated with the IP(3)-R-LBD. A mutant GFP-IP(3)-R-LBD with reduced ability to bind Ins(1,4,5)P(3) bound beclin-1 and inhibited autophagy similarly to the wild type sequence. These data provide evidence that Ins(1,4,5)P(3) and IP(3)-R act as inhibitors of autophagic responses in cardiomyocytes. By suppressing autophagy, IP(3)-R may contribute to cardiac pathology.

  12. Prostaglandin E2 induces chloride secretion through crosstalk between cAMP and calcium signaling in mouse inner medullary collecting duct cells

    Science.gov (United States)

    Rajagopal, Madhumitha; Thomas, Sheela V.; Kathpalia, Paru P.; Chen, Yu

    2013-01-01

    Under conditions of high dietary salt intake, prostaglandin E2 (PGE2) production is increased in the collecting duct and promotes urinary sodium chloride (NaCl) excretion; however, the molecular mechanisms by which PGE2 increases NaCl excretion in this context have not been clearly defined. We used the mouse inner medullary collecting duct (mIMCD)-K2 cell line to characterize mechanisms underlying PGE2-regulated NaCl transport. When epithelial Na+ channels were inhibited, PGE2 exclusively stimulated basolateral EP4 receptors to increase short-circuit current (IscPGE2). We found that IscPGE2 was sensitive to inhibition by H-89 and CFTR-172, indicating that EP4 receptors signal through protein kinase A to induce Cl− secretion via cystic fibrosis transmembrane conductance regulator (CFTR). Unexpectedly, we also found that IscPGE2 was sensitive to inhibition by BAPTA-AM (Ca2+ chelator), 2-aminoethoxydiphenyl borate (2-APB) (inositol triphosphate receptor blocker), and flufenamic acid (FFA) [Ca2+-activated Cl− channel (CACC) inhibitor], suggesting that EP4 receptors also signal through Ca2+ to induce Cl− secretion via CACC. Additionally, we observed that PGE2 stimulated an increase in Isc through crosstalk between cAMP and Ca2+ signaling; BAPTA-AM or 2-APB inhibited a component of IscPGE2 that was sensitive to CFTR-172 inhibition; H-89 inhibited a component of IscPGE2 that was sensitive to FFA inhibition. Together, our findings indicate that PGE2 activates basolateral EP4 receptors and signals through both cAMP and Ca2+ to stimulate Cl− secretion in IMCD-K2 cells. We propose that these signaling pathways, and the crosstalk between them, may provide a concerted mechanism for enhancing urinary NaCl excretion under conditions of high dietary NaCl intake. PMID:24284792

  13. 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.

  14. 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.

  15. 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...

  16. Visible luminescence of dysprosium ions in oxyhalide lead borate glasses

    Science.gov (United States)

    Pisarska, Joanna; Żur, Lidia; Pisarski, Wojciech A.

    2011-08-01

    Visible luminescence of Dy 3+ ions in oxyhalide lead borate glasses was examined. Luminescence spectra show two intense bands at 480 nm and 573 nm due to 4F 9/2 → 6H 15/2 (blue) and 4F 9/2 → 6H 13/2 (yellow) transitions of Dy 3+. Luminescence decays from 4F 9/2 state and yellow-to-blue luminescence intensity ratios (Y/B) were analysed with PbX 2 (X = F, Cl) content. An introduction of PbX 2 to the borate glass results in the increasing of 4F 9/2 lifetime and the decreasing of yellow-to-blue luminescence intensity ratio, which is due to reduction of covalency between Dy 3+ and O 2-/X - ions.

  17. FTIR of binary lead borate glass: Structural investigation

    Science.gov (United States)

    Othman, H. A.; Elkholy, H. S.; Hager, I. Z.

    2016-02-01

    The glass samples were prepared according to the following formula: (100-x) B2O3 - x PbO, where x = 20-80 mol% by melt quenching method. The density of the prepared samples was measured and molar volume was calculated. IR spectra were measured for the prepared samples to investigate the glass structure. The IR spectra were deconvoluted using curves of Gaussian shape at approximately the same frequencies. The deconvoluted data were used to study the effect of PbO content on all the structural borate groups. Some structural parameters such as density, packing density, bond length and bond force constant were theoretically calculated and were compared to the obtained experimental results. Deviation between the experimental and theoretically calculated parameters reflects the dual role of PbO content on the network of borate glass.

  18. Borate esters as convenient reagents for direct amidation of carboxylic acids and transamidation of primary amides.

    Science.gov (United States)

    Starkov, Pavel; Sheppard, Tom D

    2011-03-07

    Simple borates serve as effective promoters for amide bond formation with a variety of carboxylic acids and amines. With trimethyl or tris(2,2,2-trifluoroethyl) borate, amides are obtained in good to excellent yield and high purity after a simple work-up procedure. Tris(2,2,2-trifluoroethyl) borate can also be used for the straightforward conversion of primary amides to secondary amides via transamidation.

  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. EPR and NMR studies of amorphous aluminum borates

    NARCIS (Netherlands)

    Simon, S.; Pol, A. van der; Reijerse, E.J.; Kentgens, A.P.M.; Moorsel, G.J.M.P. van; Boer, E. de

    1994-01-01

    Amorphous aluminium borates, Al2(1–x)B2xO3 with O [less-than-or-eq]x[less-than-or-eq] 0.5, prepared from mixtures of aluminium nitrate, boric acid and glycerol, have been studied by EPR and 27Al MASNMR as a function of composition and heat-treatment temperature (Tt[less-than-or-eq] 860 °C). EPR stud

  1. EPR and NMR studies of amorphous aluminum borates

    NARCIS (Netherlands)

    Simon, S.; Pol, A. van der; Reijerse, E.J.; Kentgens, A.P.M.; Moorsel, G.J.M.P. van; Boer, E. de

    1994-01-01

    Amorphous aluminium borates, Al2(1–x)B2xO3 with O [less-than-or-eq]x[less-than-or-eq] 0.5, prepared from mixtures of aluminium nitrate, boric acid and glycerol, have been studied by EPR and 27Al MASNMR as a function of composition and heat-treatment temperature (Tt[less-than-or-eq] 860 °C). EPR stud

  2. 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.

  3. Elastic Behavior of Borate Glasses Containing Lead and Bismuth Oxides

    Directory of Open Access Journals (Sweden)

    Mehrdad Khanisanij

    2014-01-01

    Full Text Available PbO and Bi2O3 binary borate glasses with different compositions, (MOX(B2O31−X (M = Pb, Bi, have been characterized and ultrasonic velocity as well as density is taken into account. In addition, the results have been compared with those of Ag, K, and Li oxide borate glasses from others. The ultrasonic velocities (both longitudinal and transverse and density for (PbOX(B2O31−X and (Bi2O3X(B2O31−X have been measured accurately and elastic moduli as well as hardness and Poisson’s ratio was determined. It has been demonstrated that density and ultrasonic velocities are enhanced by increasing PbO and Bi2O3 molar fraction with different values for each borate glass composition. However, the enhancement of ultrasonic velocities did not carry on continuously and after reaching a maximum point, they fell down dramatically. Both PbO and Bi2O3 showed almost similar glass improvement in case of density, ultrasonic velocity, and elastic moduli.

  4. Esculetin, a natural coumarin compound, evokes Ca(2+) movement and activation of Ca(2+)-associated mitochondrial apoptotic pathways that involved cell cycle arrest in ZR-75-1 human breast cancer cells.

    Science.gov (United States)

    Chang, Hong-Tai; Chou, Chiang-Ting; Lin, You-Sheng; Shieh, Pochuen; Kuo, Daih-Huang; Jan, Chung-Ren; Liang, Wei-Zhe

    2016-04-01

    Esculetin (6,7-dihydroxycoumarin), a derivative of coumarin compound, is found in traditional medicinal herbs. It has been shown that esculetin triggers diverse cellular signal transduction pathways leading to regulation of physiology in different models. However, whether esculetin affects Ca(2+) homeostasis in breast cancer cells has not been explored. This study examined the underlying mechanism of cytotoxicity induced by esculetin and established the relationship between Ca(2+) signaling and cytotoxicity in human breast cancer cells. The results showed that esculetin induced concentration-dependent rises in the intracellular Ca(2+) concentration ([Ca(2+)]i) in ZR-75-1 (but not in MCF-7 and MDA-MB-231) human breast cancer cells. In ZR-75-1 cells, this Ca(2+) signal response was reduced by removing extracellular Ca(2+) and was inhibited by the store-operated Ca(2+) channel blocker 2-aminoethoxydiphenyl borate (2-APB). In Ca(2+)-free medium, pre-treatment with the endoplasmic reticulum Ca(2+) pump inhibitor thapsigargin (TG) abolished esculetin-induced [Ca(2+)]i rises. Conversely, incubation with esculetin abolished TG-induced [Ca(2+)]i rises. Esculetin induced cytotoxicity that involved apoptosis, as supported by the reduction of mitochondrial membrane potential and the release of cytochrome c and the proteolytic activation of caspase-9/caspase-3, which were partially reversed by pre-chelating cytosolic Ca(2+) with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl ester (BAPTA-AM). Moreover, esculetin increased the percentage of cells in G2/M phase and regulated the expressions of p53, p21, CDK1, and cyclin B1. Together, in ZR-75-1 cells, esculetin induced [Ca(2+)]i rises by releasing Ca(2+) from the ER and causing Ca(2+) influx through 2-APB-sensitive store-operated Ca(2+) entry. Furthermore, esculetin activated Ca(2+)-associated mitochondrial apoptotic pathways that involved G2/M cell cycle arrest. Graphical abstract The summary of esculetin

  5. Hydrolytic stability and tribological properties of N-containing heterocyclic borate esters as lubricant additives in rapeseed oil

    NARCIS (Netherlands)

    Li, J.; Li, Zhipeng; Ren, Tianhui; Zeng, Xiangqiong; Heide, van der Emeil

    2014-01-01

    Borate ester compounds are emerging as promising materials for lubricating systems. The main drawback of borate esters however, is the susceptiblity to hydrolysis. In this work, two kinds of N-containing heterocyclic borate esters were synthesized. Their hydrolytic stability and tribological propert

  6. 76 FR 69292 - Aging Management of Stainless Steel Structures and Components in Treated Borated Water

    Science.gov (United States)

    2011-11-08

    ... COMMISSION Aging Management of Stainless Steel Structures and Components in Treated Borated Water AGENCY... Staff Guidance (LR-ISG), LR- ISG-2011-01, ``Aging Management of Stainless Steel Structures and Components in Treated Borated Water.'' This LR-ISG revises the guidance in the Standard Review Plan...

  7. 77 FR 27815 - Aging Management of Stainless Steel Structures and Components in Treated Borated Water

    Science.gov (United States)

    2012-05-11

    ... COMMISSION Aging Management of Stainless Steel Structures and Components in Treated Borated Water AGENCY..., ``Aging Management of Stainless Steel Structures and Components in Treated Borated Water.'' This LR-ISG... Power Plants (SRP-LR) and Generic Aging Lessons Learned (GALL) Report for the aging management...

  8. 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.

  9. 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.

  10. Optical properties of lead borate glasses containing Dy3+ ions

    Science.gov (United States)

    Pisarska, Joanna

    2009-07-01

    Optical properties of lead borate glasses containing Dy3+ ions were examined using absorption and luminescence measurements and theoretical calculations based on the Judd-Ofelt framework and the Inokuti-Hirayama model. The luminescence spectra show two characteristic bands at 480 and 573 nm, which are due to 4F9/2-6H15/2 (blue) and 4F9/2-6H13/2 (yellow) transitions of trivalent Dy3+ ions. The yellow/blue luminescence and its decay were analyzed as a function of activator concentration.

  11. Luminescence behavior of Dy 3+ ions in lead borate glasses

    Science.gov (United States)

    Pisarska, Joanna

    2009-10-01

    Dy-doped lead borate glasses were studied. The luminescence spectra showed two characteristic bands at 480 and 573 nm due to 4F 9/2- 6H 15/2 (blue) and 4F 9/2- 6H 13/2 (yellow) transitions of Dy 3+. The yellow/blue luminescence of trivalent dysprosium was analyzed as a function of the B 2O 3/PbO ratios, the activator (Dy 3+) and the PbX 2 (X = F, Cl, Br) content.

  12. Nuclear quadrupole resonance of boron in borate glasses

    Science.gov (United States)

    Gravina, Samuel J.; Bray, Phillip J.

    A continuous wave nuclear quadrupole resonance spectrometer that has a high sensitivity even at low frequencies has been built. Boron and aluminum NQR has been detected in the region 200 kHz to 1.4 MHz. For the first time, boron NQR has been detected in a glass. The NQR spectrum of pure B 20 3 glass is consistent with 85 ± 2% of the boron atoms belonging to boroxol rings. In sodium borate glasses, the number of borons in boroxol rings decreases with increasing sodium content, until when sodium oxide comprises 20 mol% of the glass less than 2% of the borons are in boroxol rings.

  13. Lithium conducting ionic liquids based on lithium borate salts

    Energy Technology Data Exchange (ETDEWEB)

    Zygadlo-Monikowska, E.; Florjanczyk, Z.; Sluzewska, K.; Ostrowska, J.; Langwald, N.; Tomaszewska, A. [Warsaw University of Technology, Faculty of Chemistry, ul. Noakowskiego 3, 00-664 Warsaw (Poland)

    2010-09-15

    The simple reaction of trialkoxyborates with butyllithium resulted in the obtaining of new lithium borate salts: Li{l_brace}[CH{sub 3}(OCH{sub 2}CH{sub 2}){sub n}O]{sub 3}BC{sub 4}H{sub 9}{r_brace}, containing oxyethylene substituents (EO) of n=1, 2, 3 and 7. Salts of n {>=} 2 show properties of room temperature ionic liquid (RTIL) of low glass transition temperature, T{sub g} of the order from -70 to -80 C. The ionic conductivity of the salts depends on the number of EO units, the highest conductivity is shown by the salt with n = 3; in bulk its ambient temperature conductivity is 2 x 10{sup -5} S cm{sup -1} and in solution in cyclic propylene sulfite or EC/PC mixture, conductivity increases by an order of magnitude. Solid polymer electrolytes with borate salts over a wide concentration range, from 10 to 90 mol.% were obtained and characterized. Three types of polymeric matrices: poly(ethylene oxide) (PEO), poly(trimethylene carbonate) (PTMC) and two copolymers of acrylonitrile and butyl acrylate p(AN-BuA) were used in them as polymer matrices. It has been found that for systems of low salt concentration (10 mol.%) the best conducting properties were shown by solid polymer electrolytes with PEO, whereas for systems of high salt concentration, of the polymer-in-salt type, good results were achieved for PTMC as polymer matrix. (author)

  14. Sugar-borate esters--potential chemical agents in prostate cancer chemoprevention.

    Science.gov (United States)

    Scorei, Romulus Ion; Popa, Radu

    2013-07-01

    The potential value of sugar-borate esters (SBEs) in the chemo-preventive therapy of prostate cancer has been reviewed. We propose that SBEs act as boron (B) vehicles, increasing the concentration of borate inside cancer cells relative to normal cells. Increased intracellular concentration of borate activates borate transporters, but also leads to growth inhibition and apoptosis. The effects of SBEs on normal cells are less dramatic because SBEs are naturally-occurring biochemicals, common and abundant in some fruits and vegetables, and also because borate dissociated from SBEs in natural diet doses is easily exported from normal cells. Cancer cell lines that over-express sugar transporters or under-express borate export are potential targets for SBE-based therapy. With regard to efficiency against cancer cells and drug preparation requirements, trigonal cis-diol boric monoesters will be one of the most effective class of SBEs. Because negative correlation exists between borate intake and the incidence of prostate cancer, and because most cancer cells overexpress sugar transporters, SBEs are proposed as a potential chemopreventive avenue in the fight against primary and recurrent prostate cancer.

  15. Effect of ionic interaction of chlorode-borate and iodide-borate on their absorption by Lemna minor L

    Energy Technology Data Exchange (ETDEWEB)

    Thellier, M.; Ayadi, A.; Tromeur, C.

    1967-11-27

    The effect of borate ions on the absorption of chloride and iodide ions by Lemna minor was studied by using the radioactive tracers Cl-36 at 23/sup 0/C with an illumination of 8000 Lux and I-131 at 25.5 C with 600 Lux. The absorbed quantities of the tracer elements were measured with a Geiger counter. The concentrations of sodium chloride solutions tested ranged from 0.055 to 1 mM, those of potassium iodide from 0.04 to 4 mM. While the presence of borate ions in the test solutions of NaCl inhibited the absorption of Cl ions by Lemna minor, only a mild inhibition or none at all was noted in the case of the absorption of I ions. Because of the difference of the cations (sodium in the case of Cl, potassium in the case of I) no direct comparison can be drawn between the absorption of the two halogens. The absorption of I by the plant is thought to proceed by a much simpler mechanism than that of Cl.

  16. Laser spectroscopy of rare earth ions in lead borate glasses and transparent glass-ceramics

    Science.gov (United States)

    Pisarski, W. A.; Grobelny, Ł.; Pisarska, J.; Lisiecki, R.; Dominiak-Dzik, G.; Ryba-Romanowski, W.

    2010-03-01

    Rare earth doped lead borate glasses and transparent glass-ceramics have been studied using optical spectroscopy. Based on the absorption, emission and its decay and the Judd-Ofelt calculations, several radiative and laser parameters for Ln 3+ ( Ln = Pr, Nd, Eu, Dy, Er, Tm) were evaluated. The large values of luminescence lifetime, quantum efficiency of excited state and room temperature peak stimulated emission cross-section suggest efficient laser transitions of Ln 3+ ions in lead borate glasses. The obtained results indicate that lead borate glasses and glass-ceramics containing Ln 3+ ions are promising host matrices for solid-state laser applications.

  17. 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

  18. 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.

  19. Crystal structure of borated N,N,N′,N′-tetramethyldiaminomethane

    Directory of Open Access Journals (Sweden)

    Kathrin Louven

    2015-10-01

    Full Text Available In the title compound, {[(dimethylaminomethyl]dimethylamine}trihydridoboron, C5H17BN2, the tetrahedral geometry of the N—C—N unit is slightly disorted. As a result of the bulky amine substituents, a wider N—C—N angle of 113.6 (1° is observed. The bond lengths between the N atom and methyl groups are slighly elongated to 1.481 (2 and 1.482 (2 Å at the borated N atom, whereas the distances between the other N atom and its methyl groups are only 1.461 (2 and 1.462 (2 Å. The studied crystal was twinned. The twin data refinement was subsequently carried out with a scale factor of 0.263 (1. The two lattices of the twin domains were rotated by 179.84°.

  20. 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.

  1. Recent advances in trivalent f-element borate chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Polinski, Matthew J. [Notre Dame Univ., IN (United States). Dept. of Chemistry and Biochemistry; Alekseev, Evgeny V. [Forschungszentrum Juelich GmbH (Germany). Inst. for Energy and Climate Research (IEK-6); RWTH Aachen Univ. (Germany). Inst. fuer Kristallographie; Depmeier, Wulf [Kiel Univ. (Germany). Inst. fuer Geowissenschaften; Albrecht-Schmitt, Thomas E. [Florida State Univ., Tallahassee, FL (United States). Dept. of Chemistry and Biochemistry

    2013-11-01

    The reactions of LnCl{sub 3} . 6 H{sub 2}O with molten boric acid result in the formation of three different products depending on the identity of the lanthanide metal. The analogous reactions using AnCl{sub 3} . 6 H{sub 2}O (An = Pu(III), Am(III), and Cm(III)) with molten boric acid under the same conditions do not yield the same results as those of the 4f series or of the other 5f elements. For the most part, the actinide products obtained have no lanthanide analogues making them unique compounds. Furthermore, the reactions of LnX{sub 3} . yH{sub 2}O (X = Br, I) (Ln = La-Nd) with molten boric acid results in the formation of two products. The analagous set of reactions was performed with PuX{sub 3} . yH{sub 2}O (X = Br, I) which, yet again, gave rise to completely novel compounds. All of these compounds are three-dimensional framework structures comprised of sheets. These sheets are made up of both BO{sub 3} and BO{sub 4} units which are arranged in such a manner that creates triangular holes in which the lanthanide or actinide sites reside. The borate units of the triangular holes provide six oxygen atoms that coordinate in the equatorial region resulting in unique nine- and/or ten-coordinate geometries. The similarities and differences between the 4f and 5f borate compounds are discussed with particular emphasis on the periodic trends of this system. (orig.)

  2. Structural properties of molybdenum-lead-borate glasses

    Science.gov (United States)

    Rada, M.; Rada, S.; Pascuta, P.; Culea, E.

    2010-11-01

    Glasses and glass ceramics in the system xMoO 3·(100 - x)[3B 2O 3·PbO] with 0 ≤ x ≤ 30 mol% have been prepared from melt quenching method and characterized by means of X-ray diffraction, FTIR, UV-VIS and EPR spectroscopy. We have examined and analyzed the effects of systematic molybdenum ions intercalation on lead-borate glasses and glass ceramics with interesting results. The observations present in these mechanisms show the lead ions bonded ionic have a strong affinity towards [BO 3] units containing non-bridging oxygens and [MoO 4] 2- molybdate units. The pronounced affinity towards molybdate anions yields the formation of the PbMoO 4 crystalline phase. Then, the excess of oxygen can be supported into the glass network by the formation of [MoO 6] and [Mo 2O 7] structural units. Pb 2+ ions with 6s 2 configuration show strong absorption in the ultraviolet due to parity allowed s 2-sp transition and yield an absorption band centered at about 310 nm. The changes in the features of the absorption bands centered at about 310 nm can be explained as a consequence of the appearance of additional absorption shoulder due to photoinduced color centers in the glass such as the formation of borate-molybdate and lead-molybdate paramagnetic defect centers in the glasses. The concentration of molybdenum ions influences the shape and width of the EPR signals located at g ˜ 1.86, 1.91 and 5.19. The microenvironment of molybdenum ions in glasses is expected to have mainly sixfold coordination. However, there is a possibility of reduction of a part of molybdenum ions from the Mo 6+ to the Mo 5+ and Mo 4+ to the Mo 3+ states.

  3. "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

  4. "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

  5. Treatment of timber products with gaseous borate esters, Part 1: factors influencing the treatment process

    CSIR Research Space (South Africa)

    Turner, P

    1995-08-01

    Full Text Available Several factors which influence the treatment of timber products with vapour phase preservatives such as borate esters are considered. Gas flow rate through the substrate was found to be a significant factor limiting both preservative penetration...

  6. 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.

  7. Preparation and Characterization of Low-Dielectric Glass Composite with Aluminum Borate

    Science.gov (United States)

    Jean, Jau-Ho; Hwang, Shiang-Po

    1994-10-01

    The effect of aluminum borate ( Al18B4O33) on crystallization and thermal expansion of Pyrex borosilicate glass has been studied. X-ray diffraction (XRD) results show that with 40 vol% aluminum borate, the precipitation of cristobalite in the Pyrex borosilicate glass is completely inhibited. This result is further evidenced by the linear thermal expansion measurement in which, in contrast to the system without aluminum borate, the thermal expansion coefficient remains unchanged with sintering time and is close to that of silicon, 3×10-6 K-1. Moreover, the composite with 40 vol% aluminum borate has a dielectric constant of 5.2 and a dielectric loss of 0.8% at 1 MHz.

  8. Radiation Shielding Properties Comparison of Pb-Based Silicate, Borate, and Phosphate Glass Matrices

    OpenAIRE

    Suwimon Ruengsri

    2014-01-01

    Theoretical calculations of mass attenuation coefficients, partial interactions, atomic cross-section, and effective atomic numbers of PbO-based silicate, borate, and phosphate glass systems have been investigated at 662 keV. PbO-based silicate glass has been found with the highest total mass attenuation coefficient and then phosphate and borate glasses, respectively. Compton scattering has been the dominate interaction contributed to the different total attenuation coefficients in each of th...

  9. Optical absorption and fluorescence properties of $Er^{3+}$ in sodium borate glass

    OpenAIRE

    Ratnakaram, YC; J.Lakshmi; Chakradhar, RPS

    2005-01-01

    Spectroscopic properties of $Er^{3+}$ ions in sodium borate glass have been studied. The indirect and direct optical band gaps $(E_{opt})$ and energy level parameters (Racah $(E^{1}, E^{2} and E^{3})$, spin-orbit $(\\xi_{4f})$ and configurational interaction (\\alpha)) are evaluated. Spectral intensities for various absorption bands of $Er^{3+}$ doped sodium borate glass are calculated. Using Judd-Ofelt intensity parameters $(\\Omega_{2},\\Omega_{4}, \\Omega_{6})$, radiative transition probabiliti...

  10. 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.

  11. Efficacy of 2-APB (2-Aminoethyldiphenylborate) in Rescuing Neurons After Soman-Induced Brain Injury

    Science.gov (United States)

    2005-08-01

    processing, respectively. H&E stained brain sections were assessed for classical histopathological damage to the piriform cortex. Damage was scored...staining (i.e., necrosis [Ballough et al., 1995; Hicks et al., 1995]) in piriform cortex and contiguous brain regions (e.g., amygdaloid nuclei and...perirhinal cortex) was performed according to the procedure of Ballough et al. (1995). Previous studies have shown that the piriform cortex (with

  12. A novel method for preparing ultra-fine alumina-borate oxide fibres via an electrospinning technique

    Science.gov (United States)

    Dai, Hongqin; Gong, Jian; Kim, Hakyong; Lee, Doukrae

    2002-10-01

    Alumina-borate/PVA composite fibres were prepared using sol-gel processing and an electrospinning technique. After calcination of the thin fibres, ultra-fine fibres of alumina-borate oxide with a diameter of about 550 nm could be prepared. The fibres were characterized by SEM, XRD and FT-IR. The results showed that the crystalline phase and morphology of alumina-borate fibres were largely influenced by the calcination temperature.

  13. 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

  14. Primary pathways of intracellular Ca(2+) mobilization by nanosecond pulsed electric field.

    Science.gov (United States)

    Semenov, Iurii; Xiao, Shu; Pakhomov, Andrei G

    2013-03-01

    Permeabilization of cell membranous structures by nanosecond pulsed electric field (nsPEF) triggers transient rise of cytosolic Ca(2+) concentration ([Ca(2+)](i)), which determines multifarious downstream effects. By using fast ratiometric Ca(2+) imaging with Fura-2, we quantified the external Ca(2+) uptake, compared it with Ca(2+) release from the endoplasmic reticulum (ER), and analyzed the interplay of these processes. We utilized CHO cells which lack voltage-gated Ca(2+) channels, so that the nsPEF-induced [Ca(2+)](i) changes could be attributed primarily to electroporation. We found that a single 60-ns pulse caused fast [Ca(2+)](i) increase by Ca(2+) influx from the outside and Ca(2+) efflux from the ER, with the E-field thresholds of about 9 and 19kV/cm, respectively. Above these thresholds, the amplitude of [Ca(2+)](i) response increased linearly by 8-10nM per 1kV/cm until a critical level between 200 and 300nM of [Ca(2+)](i) was reached. If the critical level was reached, the nsPEF-induced Ca(2+) signal was amplified up to 3000nM by engaging the physiological mechanism of Ca(2+)-induced Ca(2+)-release (CICR). The amplification was prevented by depleting Ca(2+) from the ER store with 100nM thapsigargin, as well as by blocking the ER inositol-1,4,5-trisphosphate receptors (IP(3)R) with 50μM of 2-aminoethoxydiphenyl borate (2-APB). Mobilization of [Ca(2+)](i) by nsPEF mimicked native Ca(2+) signaling, but without preceding activation of plasma membrane receptors or channels. NsPEF stimulation may serve as a unique method to mobilize [Ca(2+)](i) and activate downstream cascades while bypassing the plasma membrane receptors.

  15. 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.

  16. Calcium transient evoked by TRPV1 activators is enhanced by tumor necrosis factor-{alpha} in rat pulmonary sensory neurons.

    Science.gov (United States)

    Hu, Youmin; Gu, Qihai; Lin, Ruei-Lung; Kryscio, Richard; Lee, Lu-Yuan

    2010-10-01

    TNFα, a proinflammatory cytokine known to be involved in the pathogenesis of allergic asthma, has been shown to induce hyperalgesia in somatic tissue via a sensitizing effect on dorsal root ganglion neurons expressing transient receptor potential vanilloid type 1 receptor (TRPV1). Because TRPV1-expressing pulmonary sensory neurons play an important role in regulating airway function, this study was carried out to determine whether TNFα alters the sensitivity of these neurons to chemical activators. Responses of isolated nodose and jugular ganglion neurons innervating the rat lungs were determined by measuring the transient increase in intracellular Ca(2+) concentration ([Ca(2+)](i)). Our results showed the following. 1) A pretreatment with TNFα (50 ng/ml) for ∼24 h increased significantly the peak Δ[Ca(2+)](i) evoked by capsaicin (Cap) in these neurons. A pretreatment with the same concentration of TNFα for a longer duration (∼48 h) did not further increase the response, but pretreatment for a shorter duration (1 h) or with a lower concentration (25 ng/ml, 24 h) failed to enhance the Cap sensitivity. 2) The same TNFα pretreatment also induced similar but less pronounced and less uniform increases in the responses to acid (pH 6.5-5.5), 2-aminoethoxydiphenyl borate (2-APB), a common activator of TRPV1, V2, and V3 channels, and allyl isothiocyanate (AITC), a selective activator of TRPA1 channel. 3) In sharp contrast, the responses to ATP, ACh, and KCl were not affected by TNFα. 4) The TNFα-induced hypersensitivity to Cap was not prevented by pretreatment with indomethacin (30 μM). 5) The immunoreactivity to both TNF receptor types 1 and 2 were detected in rat vagal pulmonary sensory neurons. In conclusion, prolonged treatment with TNFα induces a pronounced potentiating effect on the responses of isolated pulmonary sensory neurons to TRPV1 activators. This action of TNFα may contribute in part to the airway hyperresponsiveness induced by this cytokine.

  17. TGFβ1 downregulates neurite outgrowth, expression of Ca2+ transporters, and mitochondrial dynamics of in vitro cerebellar granule cells.

    Science.gov (United States)

    Jaskova, Katarina; Pavlovicova, Michaela; Cagalinec, Michal; Lacinova, Lubica; Jurkovicova, Dana

    2014-03-26

    Acute injury to central nervous system (CNS) triggers neurodegenerative processes that can result in serious damage or complete loss of function. After injury, production of transforming growth factor β1 (TGFβ1) increases and initiates creation of a fibrotic scar that prevents normal growth, plasticity, and recovery of damaged neurons. Administration of TGFβ1 antagonists can prevent its pathological effects. To define consequences of increased TGFβ1 release on calcium signaling, neuronal plasticity, excitability, and mitochondrial dynamics in CNS neurons we directly exposed a rat primary culture of cerebellar granule neurons to TGFβ1. We focused on changes in expression of intracellular calcium transporters, especially inositol-1,4,5-trisphosphate receptor (IP3R) type 1, mitochondrial dynamics, and membrane excitability. TGFβ1 significantly decreased the gene and protein expression of inositol-1,4,5-trisphosphate receptor type 1 and the gene expression of additional intracellular Ca transporters such as IP3R2, ryanodine receptor type 1 (RyR1), RyR2, and SERCA2. Altered calcium signaling suppressed neurite outgrowth and significantly decreased the length of the mitochondria and the frequency of mitochondrial fusion. The resting membrane potential of cerebellar granule neurons was hyperpolarized and slow after depolarization of single action potential was suppressed. LY364947, a blocker of TGFβ1 receptor I, prevented these effects, and IP3 receptor blocker 2-aminoethoxydiphenyl borate (2APB) mimicked them. After CNS injury TGFβ1 downregulates intracellular Ca levels and alters Ca signaling within injured neurons. We suggest that in our model TGFβ1 may trigger both neurodegenerative and neuroprotective events through IP3-induced Ca signaling.

  18. 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

  19. Calcium Uptake via Mitochondrial Uniporter Contributes to Palmitic Acid-induced Apoptosis in Mouse Podocytes.

    Science.gov (United States)

    Yuan, Zeting; Cao, Aili; Liu, Hua; Guo, Henjiang; Zang, Yingjun; Wang, Yi; Wang, Yunman; Wang, Hao; Yin, Peihao; Peng, Wen

    2017-02-09

    Podocytes are component cells of the glomerular filtration barrier, and their loss by apoptosis is the main cause of proteinuria that leads to diabetic nephropathy (DN). Therefore, insights into podocyte apoptosis mechanism would allow a better understanding of DN pathogenesis and thus help develop adequate therapeutic strategies. Here, we investigated the molecular mechanism of palmitic acid-inhibited cell death in mouse podocytes, and found that palmitic acid increased cell death in a dose- and time-dependent manner. Palmitic acid induces apoptosis in podocytes through up-regulation of cytosolic and mitochondrial Ca(2+) , mitochondrial membrane potential (MMP), cytochrome c release and depletion of endoplasmic reticulum (ER) Ca(2+) , The intracellular calcium chelator, 1,2-bis (2-aminophenoxy) ethane-N,N,N, N'-tetraacetic acid tetrakis acetoxymethyl ester (BAPTA-AM), partially prevented this up-regulation whereas 2-aminoethoxydiphenyl borate (2-APB), an inositol 1,4,5-triphosphate receptor (IP3R) inhibitor; dantrolene, a ryanodine receptor (RyR) inhibitor; and 4,4'-diisothiocyanatostibene-2,2'-disulfonic acid (DIDS), an anion exchange inhibitor, had no effect. Interestingly, ruthenium red and Ru360, both inhibitors of the mitochondrial Ca(2+) uniporter (MCU), blocked palmitic acid-induced mitochondrial Ca(2+) elevation, cytochrome c release from mitochondria to cytosol, and apoptosis. siRNA to MCU markedly reduced curcumin-induced apoptosis. These data indicate that Ca(2+) uptake via mitochondrial uniporter contributes to palmitic acid-induced apoptosis in mouse podocytes. This article is protected by copyright. All rights reserved.

  20. Dissecting the Ca²⁺ entry pathways induced by rotavirus infection and NSP4-EGFP expression in Cos-7 cells.

    Science.gov (United States)

    Díaz, Yuleima; Peña, Franshelle; Aristimuño, Olga Carolina; Matteo, Lorena; De Agrela, Marisela; Chemello, Maria Elena; Michelangeli, Fabian; Ruiz, Marie Christine

    2012-08-01

    Rotavirus infection modifies Ca(2+) homeostasis provoking an increase in Ca(2+) permeation, cytoplasmic Ca(2+) concentration ([Ca(2+)](cyto)), total Ca(2+) pools and, a decrease of Ca(2+) response to agonists. These effects are mediated by NSP4. The mechanism by which NSP4 deranges Ca(2+) homeostasis is not yet known. It has been proposed that the increase in [Ca(2+)](cyto) is the result of Ca(2+) release from intracellular stores, thereby activating store-operated Ca(2+) entry (SOCE). We studied the mechanisms involved in the changes of Ca(2+) permeability of the plasma membrane elicited by rotavirus infection and NSP4 expression in Cos-7 cells loaded with fura-2 or fluo-4, using inhibitors and activators of different pathways. Total depletion of ER Ca(2+) stores induced by thapsigargin or ATP was not able to elicit Ca(2+) entry in mock-infected cells to the level attained with infection or NSP4-EGFP expression. The pathway induced by NSP4-EGFP expression or infection shows properties shared by SOCE: it can be inactivated by high [Ca(2+)](cyto), is permeable to Mn(2+) and inhibited by La(3+) and the SOC inhibitor 2-aminoethoxydiphenyl borate (2-APB). Contribution of the agonist-operated channels (AOCs) to Ca(2+) entry is small and not modified by infection. The plasma membrane permeability to Ca(2+) in rotavirus infected or NSP4-EGFP expressing cells is also blocked by KB-R7943, an inhibitor of the plasma membrane Na(+)/Ca(2+) exchanger (NCX), operating in its reverse mode. In conclusion, the expression of NSP4 in infected Cos-7 cells appears to activate the NCX in reverse mode and the SOCE pathway to induce increased Ca(2+) entry.

  1. Structure modeling of terbium doped strontium-lanthanum borate

    Institute of Scientific and Technical Information of China (English)

    A. Shyichuk; S. Lis; G. Meinrath

    2014-01-01

    Terbium doped strontium-lanthanum borate, Sr3La2(BO3)4:Tb (SLB), was studied by semi-empirical computational ap-proaches using PM6 parametrization and the SPARKLE model for lanthanide(III) (Ln(III)) cations. The focus of interest was on structural aspects, e.g. the cell parameters and distribution of dopant ions between various sites as a function of dopant concentration. The cell linear dimensions were calculated to decrease linearly with increasing dopant molar concentration. SLB offered two sites for the dopant. Calculations predicted that one of these sites should be preferred by the Tb(III) dopant. The optimized cell dimensions as well as the total energies differed for structures with dopant exclusively in site 1 or site 2. Computational predictions were tested against experimental results obtained for SLB synthesized by sol-gel method varying the dopant concentration. The agreement be-tween experimental and computational results was found sufficiently promising to continue the computational studies.

  2. 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.

  3. The local structure of europium-lead-borate glass ceramics

    Science.gov (United States)

    Rada, S.; Pascuta, P.; Culea, M.; Maties, V.; Rada, M.; Barlea, M.; Culea, E.

    2009-04-01

    Glass ceramics in the xEu 2O 3(100 - x)[3B 2O 3·PbO] system with 0 ⩽ x ⩽ 50 mol% have been prepared using the melt quenching method, succeeded by heat treatment applied at 625 °C and 675 °C, respectively, for 48 h. The influence of europium ions on structural behavior of the lead-borate glass ceramics has been investigated using infrared spectroscopy and DFT calculations. The addition of europium ions into the host glass ceramics matrix leads to an increase of the glass network polymerization due to the replacement of B sbnd O sbnd B bonds by the more resistant B sbnd O sbnd Pb bonds. The structural evolution of the studied glass ceramics with the gradual increase of the europium oxide content up to 50 mol% could be explained by considering that the excess of oxygen may be accommodated by the formation of [PbO 4] structural units. Then, the formation of different ionic complexes of the lead ions will decrease the rate of crystal growth and the conversion of the glass into crystalline material becomes more difficult, in agreement to the X-ray data.

  4. Structure-property relations in lanthanide borate glasses

    Science.gov (United States)

    Chakraborty, I. N.; Day, D. E.; Lapp, J. C.; Shelby, J. E.

    1985-01-01

    Glass formation in the system Ln2O3-B2O3 (Ln = Nd, Sm) was studied. Glasses could be formed in the range from 0 to 28 mol pct rare-earth oxide (Ln2O3), but liquid immiscibility in these systems limits the range of homogeneous glasses to 0 to 1.5 and 25 to 28 mol pct Ln2O3. The infrared spectra indicate that the rare-earth-rich glasses are structurally similar to rare-earth metaborates (LnB3O6) which contain (B3O6)-infinity chains. The variation in density, transformation temperature, thermal expansion coefficient, and transformation-range viscosity of these glasses with the size of the rare-earth ion is discussed. Glasses near the metaborate composition have a transformation temperature of about 700 C, which is high for binary borate glasses. Glasses could not be formed in the systems Eu2O3-, Gd2O3-, Ho2O3-, and Er2O3-B2O3, even by quenching at 1300 C/s. The sudden lack of glass formation in the system Ln2O3-B2O3 with Ln(3+) ions smaller than Sm(3+) is explained on the basis of the size effect of the Ln(3+) ion on the stability of (B3O6)-infinity chains in these metaborates.

  5. Crystal chemical characterization of mullite-type aluminum borate compounds

    Science.gov (United States)

    Hoffmann, K.; Hooper, T. J. N.; Zhao, H.; Kolb, U.; Murshed, M. M.; Fischer, M.; Lührs, H.; Nénert, G.; Kudějová, P.; Senyshyn, A.; Schneider, H.; Hanna, J. V.; Gesing, Th. M.; Fischer, R. X.

    2017-03-01

    Al-rich aluminum borates were prepared by different synthesis routes using various Al/B ratios, characterized by diffraction methods, spectroscopy and prompt gamma activation analysis. The 11B NMR data show a small amount of BO4 species in all samples. The chemical analysis indicates a trend in the Al/B ratio instead of a fixed composition. Both methods indicate a solid solution Al5-xB1+xO9 where Al is substituted by B in the range of 1-3%. The structure of B-rich Al4B2O9 (C2/m, a=1488 pm, b=553 pm, c=1502 pm, ß=90.6°), was re-investigated by electron diffraction methods, showing that structural details vary within a crystallite. In most of the domains the atoms are orderly distributed, showing no signal for the postulated channel oxygen atom O5. The absence of O5 is supported by density functional theory calculations. Other domains show a probable disordered configuration of O5 and O10, indicated by diffuse scattering along the b direction.

  6. Polarized localization and borate-dependent degradation of the Arabidopsis borate transporter BOR1 in tobacco BY-2 cells [v1; ref status: indexed, http://f1000r.es/kv

    Directory of Open Access Journals (Sweden)

    Noboru Yamauchi

    2013-09-01

    Full Text Available In Arabidopsis the borate transporter BOR1, which is located in the plasma membrane, is degraded in the presence of excess boron by an endocytosis-mediated mechanism. A similar mechanism was suggested in rice as excess boron decreased rice borate transporter levels, although in this case whether the decrease was dependent on an increase in degradation or a decrease in protein synthesis was not elucidated. To address whether the borate-dependent degradation mechanism is conserved among plant cells, we analyzed the fate of GFP-tagged BOR1 (BOR1-GFP in transformed tobacco BY-2 cells. Cells expressing BOR1-GFP displayed GFP fluorescence at the plasma membrane, especially at the membrane between two attached cells. The plasma membrane signal was abolished when cells were incubated in medium with a high concentration of borate (3 to 5 mM. This decrease in BOR1-GFP signal was mediated by a specific degradation of the protein after internalization by endocytosis from the plasma membrane. Pharmacological analysis indicated that the decrease in BOR1-GFP largely depends on the increase in degradation rate and that the degradation was mediated by a tyrosine-motif and the actin cytoskeleton. Tyr mutants of BOR1-GFP, which has been shown to inhibit borate-dependent degradation in Arabidopsis root cells, did not show borate-dependent endocytosis in tobacco BY-2 cells. These findings indicate that the borate-dependent degradation machinery of the borate transporter is conserved among plant species.

  7. 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.

  8. A new nanosensor composed of laminated samarium borate and immobilized laccase for phenol determination

    Science.gov (United States)

    Hu, Ping; Zhou, Xinlin; Wu, Qingsheng

    2014-02-01

    A new nanosensor composed of laminated samarium borate and immobilized laccase was developed for phenol determination. The laminated samarium borate was synthesized by a mild solid-state-hydrothermal (S-S-H) method without any surfactant or Template. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) were used to characterize the samples. The morphology of the as-prepared materials was characterized by SEM, which shows that laminated samarium borate are uniform nanosheets with a layer-by-layer self-assembled single-crystal structure. These laminated samarium borate have typical diameters of 3 ~ 5 μm and the thickness of each layer is in the range of 10 ~ 80 nm. And then, these SmBO3 multilayers were used to immobilize the laccase. The proposed nanosensor composed of laminated samarium borate and immobilized laccase was successfully developed for phenol determination. Cyclic voltammetry were used to study the nanosensor. The proposed nanosensor displayed high sensitivity toward phenolic compounds. The linearity of the nanosensor for the detection of hydroquinone was obtained from 1 to 50 μM with a detection limit of 3 × 10-7 M (based on the S/N = 3).

  9. 77 FR 74883 - Aging Management of Stainless Steel Structures and Components in Treated Borated Water; Revision 1

    Science.gov (United States)

    2012-12-18

    ... COMMISSION Aging Management of Stainless Steel Structures and Components in Treated Borated Water; Revision 1... corrects License Renewal Interim Staff Guidance, LR-ISG-2011-01, ``Aging Management of Stainless Steel Structures and Components in Treated Borated Water,'' which was announced in the Federal Register on May...

  10. 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

  11. Echinacea-induced cytosolic Ca2+ elevation in HEK293.

    Science.gov (United States)

    Wu, Lankun; Rowe, Eric W; Jeftinija, Ksenija; Jeftinija, Srdija; Rizshsky, Ludmila; Nikolau, Basil J; McKay, Jodi; Kohut, Marian; Wurtele, Eve Syrkin

    2010-11-23

    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. 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. 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 components thought to be responsible for the major

  12. Radiation Shielding Properties Comparison of Pb-Based Silicate, Borate, and Phosphate Glass Matrices

    Directory of Open Access Journals (Sweden)

    Suwimon Ruengsri

    2014-01-01

    Full Text Available Theoretical calculations of mass attenuation coefficients, partial interactions, atomic cross-section, and effective atomic numbers of PbO-based silicate, borate, and phosphate glass systems have been investigated at 662 keV. PbO-based silicate glass has been found with the highest total mass attenuation coefficient and then phosphate and borate glasses, respectively. Compton scattering has been the dominate interaction contributed to the different total attenuation coefficients in each of the glass matrices. The silicate and phosphate glass systems are more appropriate choices as lead-based radiation shielding glass than the borate glass system. Moreover, comparison of results has shown that the glasses possess better shielding properties than standard shielding concretes, suggesting a smaller size requirement in addition to transparency in the visible region.

  13. Esterification of Carboxylic Acids and Diacids by Trialkyl Borate under Solvent- and Catalyst-Free Conditions

    Institute of Scientific and Technical Information of China (English)

    MANSOORI Yagoub; TATAROGLU SEYIDOV Firdovsi; BOHLOOLI Shahrbanoo; ZAMANLOO Mohammad Reza; IMANZADEH Gholam Hassan

    2007-01-01

    Esterification or transesterification reactions are usually carried out in the presence of homogeneous or heterogeneous catalysts.However,recently a new method was reported for the esterification of carboxylic acids by tributyl borate under solvent- and catalyst-free conditions.In order to show the synthetic ability of trialkyl borate esters in the esterification reactions,here,the esterification of other carboxylic acids and diacids by tributyl-,triisoamyl-,and tribenzyl borate under the same conditions were reported.Some of the prepared ester and diester products have found wide applications as plasticizers and synthetic ester base lubricants.The esterification reactions have been cleanly carried out in the absence of any solvent under catalyst-free conditions.The maximum rate belongs to isoamyl trichloroacetate (Ⅵb) which reached about 76% within about 6.5 h.On the basis of obtained findings,it seems that electron withdrawing groups on carboxylic acid facilitate the esterification reaction.

  14. Dopant Concentration and Effective Atomic Number of Copper-Doped Potassium Borate Glasses

    Directory of Open Access Journals (Sweden)

    I. Hossain

    2013-01-01

    Full Text Available Copper-doped (0.5 mol% and undoped potassium borate glasses have been prepared by the composition of (100-xH3BO3 + xK2CO3, where 10 ≤ x ≤ 30 mol % by the traditional melting quenching method. The structural pattern of glasses with different composition has been identified by X-ray diffraction (XRD. The glow curves were analysed to determine various characterizations of the TLDs. Identification of the compositions and concentrations and effective atomic number of undoped and doped potassium borate glass was carried out using scanning electron microscope analysis (SEM. The dopant concentrations are found to be 0.25 mol%, while Zeff are 11.42 and 10.48 for Cu-doped and undoped potassium borate glasses, respectively.

  15. 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.

  16. 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.

  17. 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

  18. 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

  19. Structural and acoustical studies of lead sodium borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Saddeek, Yasser B. [Physics Department, Faculty of Science, Al-Azhar University, Assiut P.O. 71452 (Egypt)], E-mail: ysaddeek@gmail.com

    2009-01-07

    Glasses in the system Na{sub 2-2x}B{sub 4-4x}Pb{sub x}O{sub 7-6x}, 0 {<=} x {<=} 0.8, have been prepared by the melt quenching technique. Elastic properties and Debye temperature have been investigated using sound velocity measurements at 4 MHz. The ultrasonic parameters along with the IR spectroscopic studies have been employed to study the role of PbO on the structure of Na{sub 2}B{sub 4}O{sub 7} glass. The density, the molar volume, and the ultrasonic parameters of these samples have been found to be compositional dependent. The results indicate that PbO acts as a network modifier in the range 0 {<=} x {<=} 0.4, while beyound x = 0.4, PbO acts as a network former which affects the diborate units that mainly consist the strong borate network. These results are interpreted in terms of the IR analysis that indicates the transformation of the structural units BO{sub 3} into BO{sub 4}, the increase in the number of non-bridging oxygen atoms, and the substitution of longer Pb-O bond length, in place of shorter B-O bond. The observed compositional dependence of the elastic moduli is interpreted in terms of the effect of PbO on the boron-coordination number of the glass structure and to the relatively large electron-phonon anharmonic interactions. A good correlation was observed between the experimentally determined elastic moduli and those computed according to Makishima-Mackenzie model.

  20. Removal of borate by coprecipitation with Mg/Al layered double hydroxide

    Science.gov (United States)

    Kurashina, Masashi; Inoue, Tatsuki; Tajima, Chihiro; Kanezaki, Eiji

    2015-03-01

    Borate has been used for various industrial products and excessive dose of boron is harmful to humans. We investigated the removal of borate by direct coprecipitation with Mg/Al layered double hydroxide. In this study, the maximum removal of boron was 90% when Mg 30 mmol and Al 15 mmol at pH = 10 were used for 498 mg/l as B. The boron adsorption isotherms could be fitted to Langmuir model. The calculated constant Ws, saturation limit of boron adsorption, is 25 ± 2 mg/g and it is larger than that of ion exchange reaction (Ws = 15±1 mg/g).

  1. On the Anionic Group Approximation to the Borate Nonlinear Optical Materials

    Directory of Open Access Journals (Sweden)

    Rukang Li

    2017-02-01

    Full Text Available In this mini-review type of article, a brief summary of the anionic group approximation as it relates to the borate nonlinear optical (NLO crystals, an idea firstly proposed by Professor Chen, is presented.The basic idea, calculation method, tabulated coefficients of various common borate, as well as nitrate or carbonate groups, in their ideal geometries will be presented. New practices reveal that those parameters can still give very accurate predicted NLO coefficients for recently found NLO crystals without any adjustment of parameters.

  2. Structural and optical properties of niobium doped silver-lead-borate glasses

    Science.gov (United States)

    Sathish, M.; Eraiah, B.

    2013-06-01

    Nb2O5 doped silver lead borate glasses with the chemical composition (29—x)PbO-1Ag2O-70B2O3-xNb2O5 (where x=0.1mol % and 0.5 mol %) have prepared by conventional melt quenching method. FTIR and UV absorption technique have been used in order to obtain the information concerning network structure. As Nb2O5 concentration increased, the borate glass network is shown to change three coordinated to four coordinated boron system. SEM technique confines glassy nature of the prepared samples. The calculated optical band gap increases with increase Nb2O5 concentration.

  3. Evaluation of borated aluminum products for criticality control in 235-F

    Energy Technology Data Exchange (ETDEWEB)

    Crouch, W. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2003-04-01

    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-O1 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 10-8 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 strengths (yield and ultimate) of the borated

  4. Evaluation of borated aluminum products for criticality control in 235-F

    Energy Technology Data Exchange (ETDEWEB)

    Duncan, A. [Savannah River Site (SRS), Aiken, SC (United States); Sindelar, R. [Savannah River Site (SRS), Aiken, SC (United States)

    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

  5. 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.

  6. General and Localized corrosion of Austenitic and Borated Stainless Steels in Simulated Concentrated Ground Waters

    Energy Technology Data Exchange (ETDEWEB)

    D. Fix; J. Estill; L. Wong; R. Rebak

    2004-05-28

    Boron containing stainless steels are used in the nuclear industry for applications such as spent fuel storage, control rods and shielding. It was of interest to compare the corrosion resistance of three borated stainless steels with standard austenitic alloy materials such as type 304 and 316 stainless steels. Tests were conducted in three simulated concentrated ground waters at 90 C. Results show that the borated stainless were less resistant to corrosion than the witness austenitic materials. An acidic concentrated ground water was more aggressive than an alkaline concentrated ground water.

  7. General and Localized Corrosion of Austenitic And Borated Stainless Steels in Simulated Concentrated Ground Waters

    Energy Technology Data Exchange (ETDEWEB)

    Estill, J C; Rebak, R B; Fix, D V; Wong, L L

    2004-03-11

    Boron containing stainless steels are used in the nuclear industry for applications such as spent fuel storage, control rods and shielding. It was of interest to compare the corrosion resistance of three borated stainless steels with standard austenitic alloy materials such as type 304 and 316 stainless steels. Tests were conducted in three simulated concentrated ground waters at 90 C. Results show that the borated stainless were less resistant to corrosion than the witness austenitic materials. An acidic concentrated ground water was more aggressive than an alkaline concentrated ground water.

  8. Unusual stoichiometry control in the atomic layer deposition of manganese borate films from manganese bis(tris(pyrazolyl)borate) and ozone

    Energy Technology Data Exchange (ETDEWEB)

    Klesko, Joseph P.; Bellow, James A.; Saly, Mark J.; Winter, Charles H., E-mail: chw@chem.wayne.edu [Department of Chemistry, Wayne State University, Detroit, Michigan 48202 (United States); Julin, Jaakko; Sajavaara, Timo [Department of Physics, University of Jyväskylä, 40014 Jyväskylä (Finland)

    2016-09-15

    The atomic layer deposition (ALD) of films with the approximate compositions Mn{sub 3}(BO{sub 3}){sub 2} and CoB{sub 2}O{sub 4} is described using MnTp{sub 2} or CoTp{sub 2} [Tp = tris(pyrazolyl)borate] with ozone. The solid state decomposition temperatures of MnTp{sub 2} and CoTp{sub 2} are ∼370 and ∼340 °C, respectively. Preparative-scale sublimations of MnTp{sub 2} and CoTp{sub 2} at 210 °C/0.05 Torr afforded >99% recoveries with <0.1% nonvolatile residues. Self-limited ALD growth was demonstrated at 325 °C for MnTp{sub 2} or CoTp{sub 2} with ozone as the coreactant. The growth rate for the manganese borate process was 0.19 Å/cycle within the ALD window of 300–350 °C. The growth rate for the cobalt borate process was 0.39–0.42 Å/cycle at 325 °C. X-ray diffraction of the as-deposited films indicated that they were amorphous. Atomic force microscopy of 35–36 nm thick manganese borate films grown within the 300–350 °C ALD window showed root mean square surface roughnesses of 0.4–0.6 nm. Film stoichiometries were assessed by x-ray photoelectron spectroscopy and time of flight-elastic recoil detection analysis. The differing film stoichiometries obtained from the very similar precursors MnTp{sub 2} and CoTp{sub 2} are proposed to arise from the oxidizing ability of the intermediate high valent manganese oxide layers and lack thereof for cobalt.

  9. Optical properties of Eu2+-doped strontium borate glasses containing F- and Li+ ions

    Institute of Scientific and Technical Information of China (English)

    HUANG Yanlin; JANG Kiwan; WANG Xigang; JIANG Chuanfang

    2008-01-01

    In this experiment, strontium borate glasses were prepared using the conventional quenching method in air atmosphere. Optical absorption, photoluminescence excitation and emission spectra, X-ray excited luminescence (XEL), and luminescence decay curve of the as-prepared glasses were investigated at room temperature. The as-prepared glasses had two kinds of Eu ions, i.e., Eu2+ and Eu3+. Compared with the reported results of strontium borate glasses, Eu2+ luminescence was enhanced in the studied strontium borate glasses coprepared with F- and Li+ ions. The coexisting of Li+ or F- in the borate glasses could create more negative defect VSr″ and stabilize Eu2+ ions, which might act as donor of electrons;For the F- doping, the new center of B(O, F)4 (or BO3F) and BO2F2 units could be considered to be the distorted (BO4), which were needed as a rigid framework to stabilize the divalent rare earth ions.

  10. Preparation of α-Bromoketones Involving the Reaction of Enol Triethyl Borates with N-Bromosuccinimide

    Directory of Open Access Journals (Sweden)

    Izabella Jastrzebska

    2013-01-01

    Full Text Available The ketones (5α- and 5β-cholestan-3-one and (1S,7aS-1-tert-butoxy-hexahydro-7a-methyl-1H-inden-5-one were efficiently α-monobrominated by treatment of the corresponding enol triethyl borates with N-bromosuccinimide (NBS.

  11. 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)

  12. Synthesis and study on the luminescence properties of cadmium borate phosphors

    Energy Technology Data Exchange (ETDEWEB)

    Annalakshmi, O. [Radiological Safety Division, Indira Gandhi Center for Atomic Research, Kalpakkam 603102, Tamilnadu (India); Jose, M.T., E-mail: mtjosein@yahoo.co.in [Radiological Safety Division, Indira Gandhi Center for Atomic Research, Kalpakkam 603102, Tamilnadu (India); Venkatraman, B. [Radiological Safety Division, Indira Gandhi Center for Atomic Research, Kalpakkam 603102, Tamilnadu (India); Amarendra, G. [Materials Physics Division, Indira Gandhi Center for Atomic Research, Kalpakkam 603102, Tamilnadu (India)

    2014-02-01

    Highlights: • Cadmium borate synthesized by solid state sintering technique. • Neutron sensitivity of the material ten times that of TLD-600. • Gamma sensitivity is found to be twice that of TLD-100. • Gamma response is linear from 0.1 to 10{sup 3} mGy. - Abstract: Cadmium borate compound prepared through wet chemical reaction from the starting chemicals followed by high temperature solid state synthesis below the melting point to get the final TL phosphor powder. Phase purity and bond details of cadmium borate crystals are characterized using X-ray diffraction technique and infrared spectroscopy. Feasibility of these materials for radiation dosimetry applications was studied after gamma and neutron irradiation. Gamma irradiation of undoped phosphors show a single peak around 185 °C whereas doping with gadolinium and silver, new more intense peak observed at 290 °C. Irradiation to thermal neutrons revealed single peak around 170 °C for all the phosphors. TL emission spectra and photoluminescence (PL) studies were also carried out on the phosphors. These borate materials are found to be highly sensitive to neutrons and hence can be used for neutron detection. Neutron sensitivity of the material is about ten times that of TLD-600.

  13. Characterization and Neutron Shielding Behavior of Dehydrated Magnesium Borate Minerals Synthesized via Solid-State Method

    Directory of Open Access Journals (Sweden)

    Azmi Seyhun Kipcak

    2013-01-01

    Full Text Available Magnesium borates are one of the major groups of boron minerals that have good neutron shielding performance. In this study, dehydrated magnesium borates were synthesized by solid-state method using magnesium oxide (MgO and boron oxide (B2O3, in order to test their ability of neutron shielding. After synthesizing the dehydrated magnesium borates, characterizations were done by X-ray Diffraction (XRD, fourier transform infrared (FT-IR, Raman spectroscopy, and scanning electron microscopy (SEM. Also boron oxide (B2O3 contents and reaction yields (% were calculated. XRD results showed that seven different types of dehydrated magnesium borates were synthesized. 1000°C reaction temperature, 240 minutes of reaction time, and 3 : 2, 1 : 1 mole ratios of products were selected and tested for neutron transmission. Also reaction yields were calculated between 84 and 88% for the 3 : 2 mole ratio products. The neutron transmission experiments revealed that the 3 : 2 mole ratio of MgO to B2O3 neutron transmission results (0.618–0.655 was better than the ratio of 1 : 1 (0.772–0.843.

  14. Tetrakis(1-imidazolyl) borate (BIM4) based zwitterionic and related molecules used as electron injection layers

    Science.gov (United States)

    Li, Huaping; Xu, Yunhua; Bazan, Guillermo C

    2013-02-05

    Tetrakis(1-imidazolyl)borate (BIm4) based zwitterionic and/or related molecules for the fabrication of PLEDs is provided. Device performances with these materials approaches that of devices with Ba/Al cathodes for which the cathode contact is ohmic. Methods of producing such materials, and electron injection layers and devices containing these materials are also provided.

  15. 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.

  16. Crystallization of Reduced Strontium and Barium Niobate Perovskites from Borate Fluxes.

    NARCIS (Netherlands)

    Hessen, B.; Sunshine, S.A.; Siegrist, T.; Jimenez, R.

    1991-01-01

    Single crystals of three AxNbO3 (A = Sr, Ba) reduced niobate cubic perovskites have been obtained by recrystallization of reduced ternary ceramic precursors from borate fluxes under high-vacuum. Product formation could be influenced by variation of the alkaline-earth metal oxide content of the flux,

  17. STRUCTURE AND DYNAMICS OF ALKALI BORATE GLASSES - A MOLECULAR-DYNAMICS STUDY

    NARCIS (Netherlands)

    VERHOEF, AH; DENHARTOG, HW

    1995-01-01

    Structural and dynamical properties of lithium, cesium and mixed alkali (i.e., lithium and cesium) borate glasses have been studied by the molecular dynamics method. The calculations yield glass structures consisting of planar BO3 triangles and BO4 tetrahedrons with no sixfold ring structures at all

  18. 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.

  19. 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)

  20. Pressure-Induced Phase Transitions In Gadolinium Iron Borate

    Science.gov (United States)

    Kharlamova, S. A.; Struzhkin, V. V.; Sinogeikin, S. V.; Gavriliuk, A. G.; Brown, D.; Toellner, T.; Zhao, J.; Lerche, M.; Lyubutin, I. S.; Ovchinnikov, S. G.; Alp, E. E.; Sturhahn, W.

    2007-12-01

    An understanding of spin crossover (SC) dynamics is relevant to understanding of a role or participation of SC in natural systems including lower Mantle minerals, heme proteins as well as from fundamental science of view. For example, pressure-induced electronic spin transitions of Fe2+ and Fe3+ iron occur in magnesiowustite, silicate perovskite and post-perovskite which are abundant minerals in the Earth's lower mantle [1-3]. Such a SC phenomenon has recently been observed in a number of magnetic minerals FeBO3 [4, 5], BiFeO3 [6], Fe2O3 [7], and Y3Fe5O12 [8], (La, Pr)FeO3 [9, 10]. In those cases, iron ions are in the trivalent state Fe3+ and the high-spin-low-spin (HS-LS) crossover is manifested as the collapse of the local magnetic moment and as the transition of the antiferromagnet to a paramagnetic state. For example, in FeBO3 at low temperatures a spin-crossover and some magnetic transitions with two triple points were found [4, 5]. Gadolinium iron borate, GdFe3(BO3)4 is also a system with SEC and recently, we have reported on phase transitions induced by high pressures in this material [11, 12]. We studied the structural and magnetic behavior of GdFe573(BO3)4 at high pressures and temperatures using a diamond anvil cell and a Synchrotron Mossbauer Spectroscopy technique. The hyperfine parameters and results obtained from the experiments are discussed. Based on our experimental data and theoretical calculation a tentative magnetic P-T phase diagram and an equation of states of GdFe573(BO3)4 are proposed. Important features of the phase diagram are a spin crossover, insulator-semiconductor transition and possible presence of two triple points where magnetic and paramagnetic phases of the high-spin and low-spin states coexist. 1. J. Badro, J.-P. Rueff, G. Vankó, et al., Science 305, 383 (2004). 2. J. M. Jackson, W. Sturhahn, G. Shen, et al., American Mineralogist 90, 199 (2005). 3. J.Li, V.V. Struzhkin, H.-K. Mao, et al., PNAS 101, 14027 (2004). 4. I.A. Troyan

  1. The effects of borate minerals on the synthesis of nucleic acid bases, amino acids and biogenic carboxylic acids from formamide.

    Science.gov (United States)

    Saladino, Raffaele; Barontini, Maurizio; Cossetti, Cristina; Di Mauro, Ernesto; Crestini, Claudia

    2011-08-01

    The thermal condensation of formamide in the presence of mineral borates is reported. The products afforded are precursors of nucleic acids, amino acids derivatives and carboxylic acids. The efficiency and the selectivity of the reaction was studied in relation to the elemental composition of the 18 minerals analyzed. The possibility of synthesizing at the same time building blocks of both genetic and metabolic apparatuses, along with the production of amino acids, highlights the interest of the formamide/borate system in prebiotic chemistry.

  2. 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

  3. NMR and Nqr Study of Atomic Order in Alkali Borate Glasses.

    Science.gov (United States)

    Gravina, Samuel John

    A modified Robinson oscillator circuit was built for the detection of nuclear quadrupole resonance (NQR) in the 200 to 10,000 kHz region. The circuit demonstrates near ideal performance with the detected noise limited only by the sample temperature. The use of computer controlled data acquisition and a carefully designed sample probe allows for the use of an integrating time constant of up to 6 hours. This spectrometer has been used to detect ^{10}B and ^{11 }B NQR in lithium and sodium borate glasses and crystals. In pure boron oxide glass two distinct boron sites are found. By comparing this experiment with previous NMR and Raman spectroscopy studies, one of the sites, which comprises 85% of the total boron, can be attributed to boron atoms in boroxol rings. As sodium is added to the glass the abundance of boroxol rings decreases. At 20 mol% sodium oxide less than 2% of the boron atoms are found in boroxol rings. The dipole-dipole interaction between lithium cations and four-coordinated boron atoms (B_4 units) has been measured. It is found that every B_4 unit has one lithium cation next to it at an average distance of 2.82 A. A comparison with lithium borate crystals shows that diborate groups do not occur in significant quantities. Both high field and low field NMR studies of the boron quadrupole interaction in a B_4 unit also show that diborate groups are not found in the glass. A ^{23}Na and ^6Li NMR MASS study of lithium and sodium borate glasses shows that ^{23 }Na chemical shifts can distinguish sodium cations bound to non-bridging oxygens from sodium cations bound to bridging oxygens. The chemical shifts measured in lithium-sodium borate glasses are identical to those measured in lithium borate or sodium borate glasses, indicating similar alkali-oxygen coordination. A significant narrowing of the ^6Li NMR spectrum in a mixed alkali glass can be understood as a decrease in the entropy of the lithium cations. This result is consistent with the weak

  4. Low-spin hexacoordinate Mn(III): synthesis and spectroscopic investigation of homoleptic tris(pyrazolyl)borate and tris(carbene)borate complexes.

    Science.gov (United States)

    Forshaw, Adam P; Smith, Jeremy M; Ozarowski, Andrew; Krzystek, J; Smirnov, Dmitry; Zvyagin, S A; Harris, T David; Karunadasa, Hemamala I; Zadrozny, Joseph M; Schnegg, Alexander; Holldack, Karsten; Jackson, Timothy A; Alamiri, Ahmad; Barnes, Diane M; Telser, Joshua

    2013-01-07

    Three complexes of Mn(III) with "scorpionate" type ligands have been investigated by a variety of physical techniques. The complexes are [Tp(2)Mn]SbF(6) (1), [Tp(2)*Mn]SbF(6) (2), and [{PhB(MeIm)(3)}(2)Mn](CF(3)SO(3)) (3a), where Tp(-) = hydrotris(pyrazolyl)borate anion, Tp*(-) = hydrotris(3,5-dimethylpyrazolyl)borate anion, and PhB(MeIm)(3)(-) = phenyltris(3-methylimidazol-2-yl)borate anion. The crystal structure of 3a is reported; the structures of 1 and 2 have been previously reported, but were reconfirmed in this work. The synthesis and characterization of [{PhB(MeIm)(3)}(2)Mn]Cl (3b) are also described. These complexes are of interest in that, in contrast to many hexacoordinate (pseudo-octahedral) complexes of Mn(III), they exhibit a low-spin (triplet) ground state, rather than the high-spin (quintet) ground state. Solid-state electronic absorption spectroscopy, SQUID magnetometry, and high-frequency and -field electron paramagnetic resonance (HFEPR) spectroscopy were applied. HFEPR, in particular, was useful in characterizing the S = 1 spin Hamiltonian parameters for complex 1, D = +19.97(1), E = 0.42(2) cm(-1), and for 2, D = +15.89(2), E = 0.04(1) cm(-1). In addition, frequency domain Fourier-transform THz-EPR spectroscopy, using coherent synchrotron radiation, was applied to 1 only and gave results in good agreement with HFEPR. Variable-temperature dc magnetic susceptibility measurements of 1 and 2 were also in good agreement with the HFEPR results. This magnitude of zero-field splitting (zfs) is over 4 times larger than that in comparable hexacoordinate Mn(III) systems with S = 2 ground states. Complexes 3a and 3b (i.e., regardless of counteranion) have a yet much larger magnitude zfs, which may be the result of unquenched orbital angular momentum so that the spin Hamiltonian model is not appropriate. The triplet ground state is rationalized in each complex by ligand-field theory (LFT) and by quantum chemistry theory, both density functional theory and

  5. 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.

  6. Fast Decomposition Procedure of Solid Samples by Lithium Borates Fusion Employing Salicylic Acid.

    Science.gov (United States)

    Trdin, Miha; Nečemer, Marijan; Benedik, Ljudmila

    2017-03-07

    A new fast decomposition procedure for solid samples was developed. In this study, we investigated decomposition of samples by lithium borates fusion in combination with salicylic acid. The method described shortens the time required for the sample to be digested and loaded to a resin to up to 2 h, and it was especially suitable for alpha spectrometry measurements in emergency situations. Additionally, the method results in high radiochemical recoveries and when compared to other digestion methods (classical digestion utilizing mineral acids, microwave digestion, and lithium borates fusion in combination with polyethylene glycol (PEG)) gives comparable activity concentration values. The method used was applied to various reference materials with inorganic and organic matrices as well as widely varying amounts of uranium radioisotopes content. The results obtained were compared with reference and literature values and show that the proposed method can be successfully implemented on various types of samples.

  7. 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.

  8. Structural systematic and crystal chemistry of novel borates with REE, Pb, Sr, and alkali metals

    Energy Technology Data Exchange (ETDEWEB)

    Belokoneva, E.L. [Moscow State Univ., Moscow (Russian Federation). Dept. of Crystallography and Crystal Chemistry

    2013-11-01

    Crystal structures of novel borates with REE, Pb, Sr and alkali metals were analyzed using classical fundamental buildings blocks approach. It is demonstrated that hexa-, penta-, tetra-, tri- and diborates subdivisions in systematic are real families of structures with the common peculiarities. According to the symmetrical way and the degree of FBB condensation structural-generic rows exist in every of subdivisions. Mega- or polyborates subdivision is valid for the structures with the different types of simplest FBB. In all new complex borates it is possible to separate FBB of equal or different types which are presented in isolated form or are connected into chains, layers or frameworks, and to find unexpected correlation between structures. The possibility to recognize and to visualize in this approach the polarity or non-polarity of the structural units and correspondingly the polarity or nonpolarity of the structures in the whole is very important for the conclusion on structure-properties relation. (orig.)

  9. 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.

  10. EFFECT OF UV LASER ON SPECTRAL PROPERTIES OF BORATE GLASSES DOPED WITH COPPER CHLORIDE NANOCRYSTALS

    Directory of Open Access Journals (Sweden)

    A. N. Babkina

    2017-01-01

    Full Text Available We present the results of the pulsed ultraviolet laser effect on the spectral properties of the potassium-aluminium-borate glasses doped with the copper chloride nanocrystals with the average size of 3.1-6.3 nm. We have studied the changes of the exciton absorption spectra of the CuCl nanocrystals induced by different duration of the laser exposure. The results show the possibility of the laser-induced crystallization and growth of the nanocrystals. For the first time the effect of the irreversible photochromism has been obtained in the potassium-aluminium-borate glasses doped with the copper chloride nanocrystals. The effect is associated with the formation of the temperature stable Cu0n colloidal color centers.

  11. Synthesis, characterization, thermal and antioxidant studies of potassium dihydrobisphenothiazinyl borate and its transition metal complexes.

    Science.gov (United States)

    Nami, Shahab A A; Alam, Mahboob; Husain, Ahmad; Parveen, Mehtab

    2012-10-01

    The bidentate borate anion H(2)B(ptz)(2)(-) and its transition metal complexes have been synthesized and characterized by elemental analyses, magnetic susceptibility, electronic, IR, (1)H and (13)C NMR data. The molar conductance of 10(-3) M solution for all the complexes supports their non-ionic nature. The TGA profile of borate anion shows a single stage unlike that of two stage decomposition plot of the metal complexes. On the basis of spectroscopic studies the geometry of all the complexes have been proposed to be distorted-tetrahedral. The in vitro antioxidant and lipid oxidation inhibition of the ligand and its complexes have also been studied. The Cu[B(ptz)(2)](2) complex was found to be most effective in all the studies.

  12. Rare earth-doped lead borate glasses and transparent glass-ceramics: structure-property relationship.

    Science.gov (United States)

    Pisarski, W A; Pisarska, J; Mączka, M; Lisiecki, R; Grobelny, Ł; Goryczka, T; Dominiak-Dzik, G; Ryba-Romanowski, W

    2011-08-15

    Correlation between structure and optical properties of rare earth ions in lead borate glasses and glass-ceramics was evidenced by X-ray-diffraction, Raman, FT-IR and luminescence spectroscopy. The rare earths were limited to Eu(3+) and Er(3+) ions. The observed BO(3)↔BO(4) conversion strongly depends on the relative PbO/B(2)O(3) ratios in glass composition, giving important contribution to the luminescence intensities associated to (5)D(0)-(7)F(2) and (5)D(0)-(7)F(1) transitions of Eu(3+). The near-infrared luminescence and up-conversion spectra for Er(3+) ions in lead borate glasses before and after heat treatment were measured. The more intense and narrowing luminescence lines suggest partial incorporation of Er(3+) ions into the orthorhombic PbF(2) crystalline phase, which was identified using X-ray diffraction analysis.

  13. 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.

  14. Fluorescence properties of Eu 3+ 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 Eu 3+ ions doped borate and fluoroborate glasses modified with Li +, Zn 2+ and Pb 2+ cations have been investigated. The magnitude of splittings of 7F 1 levels are analyzed using crystal-field (CF) analysis. The relative intensities of 5D 0 → 7F 2 to 5D 0 → 7F 1 transitions, crystal-field strength parameters and decay times of the 5D 0 level have been determined and are found to be lower for Pb based glasses than those of Zn/Li based glasses. The lifetimes of 5D 0 level are found to increase when borate glasses are modified with pure fluorides than with oxides and oxyfluorides. The fluorescence decay of 5D 0 level fits perfect single exponential in the Eu 3+:glass systems studied which indicates the absence of energy transfer between Eu 3+ ions in these glasses.

  15. Erbium-doped oxide and oxyhalide lead borate glasses for near-infrared broadband optical amplifiers

    Science.gov (United States)

    Pisarski, Wojciech A.; Pisarska, Joanna; Lisiecki, Radosław; Grobelny, Łukasz; Dominiak-Dzik, Grażyna; Ryba-Romanowski, Witold

    2009-04-01

    Near-infrared luminescence spectra at 1.53 μm due to main 4I 13/2- 4I 15/2 laser transition of Er 3+ ions in oxide and oxyhalide lead borate glasses were examined. Spectroscopic parameters like spectral linewidth and luminescence lifetime were analyzed with PbX 2 (X = F, Cl or Br) doping. An introduction of lead halide to the borate glass results in the reduction of spectral linewidth and the increase of luminescence lifetime of Er 3+. The luminescence decay from the 4I 13/2 upper state of Er 3+ is longer for glass sample with PbF 2 than PbX 2 (X = Cl or Br).

  16. Intense upconversion fluorescence in Tm 3+/Yb3+ codoped alumina lead borate glasses

    Science.gov (United States)

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

    2016-09-01

    The Tm3+/Yb3+ codoped alumina lead borate glasses were prepared by the conventional melt quenching technique. Optical absorption and FTIR spectra were recorded. The upconversion fluorescence spectra exhibited weak blue (480 nm) and intense red (660 nm) emissions due to 1G4 → 3H6 and 1G4 → 3H4 transitions, respectively. The results concluded that both emissions are due to three photon absorption process. It has been observed that in the upconversion efficiency increases with the increase in the concentration of Yb3+ ions. The strong red upconversion fluorescence indicate that Tm3+/Yb3+ codoped alumina lead borate glasses can be used as potential host material for upconversion lasers.

  17. Structural role of europium ions in lead -borate glasses inferred from spectroscopic and DFT studies

    Science.gov (United States)

    Rada, S.; Culea, M.; Neumann, M.; Culea, E.

    2008-07-01

    Glasses in the system xEu 2O 3 · (100 - x)[3B 2O 3·PbO] with 0 ⩽ x ⩽ 35 mol% have been prepared from melt quenching method. Structural changes, as recognized by analyzing band shapes of IR spectra, revealed that Eu 2O 3 causes a change from the continuous borate network to the continuous lead-borate network, interconnected through Pb-O-B and B-O-B bridges. DFT calculations show that lead atoms occupy three different sites in the proposed model. Comparing the theoretical and experimental data, we conclude that the performance of the method/basis sets used on the prediction of the structural data and vibrational modes is good.

  18. Rare earth-doped lead borate glasses and transparent glass-ceramics: Structure-property relationship

    Science.gov (United States)

    Pisarski, W. A.; Pisarska, J.; Mączka, M.; Lisiecki, R.; Grobelny, Ł.; Goryczka, T.; Dominiak-Dzik, G.; Ryba-Romanowski, W.

    2011-08-01

    Correlation between structure and optical properties of rare earth ions in lead borate glasses and glass-ceramics was evidenced by X-ray-diffraction, Raman, FT-IR and luminescence spectroscopy. The rare earths were limited to Eu 3+ and Er 3+ ions. The observed BO 3 ↔ BO 4 conversion strongly depends on the relative PbO/B 2O 3 ratios in glass composition, giving important contribution to the luminescence intensities associated to 5D 0- 7F 2 and 5D 0- 7F 1 transitions of Eu 3+. The near-infrared luminescence and up-conversion spectra for Er 3+ ions in lead borate glasses before and after heat treatment were measured. The more intense and narrowing luminescence lines suggest partial incorporation of Er 3+ ions into the orthorhombic PbF 2 crystalline phase, which was identified using X-ray diffraction analysis.

  19. Structure and Properties of Reduced Barium Niobium Oxide Single Crystals Obtained from Borate Fluxes

    NARCIS (Netherlands)

    Hessen, B.; Sunshine, S.A.; Siegrist, T.; Fiory, A.T.; Waszczak, J.V.

    1991-01-01

    Single crystals of the reduced niobate Ba2Nb15O32 are produced by heating NbO2 in BaO·3B2O3 under high-vacuum conditions. The borate acts both as a source of BaO and as a flux for crystallization. The compound Ba2Nb15O32 crystallizes in space group R3 (a = 7.777 (1) Å, c = 35.518 (6) Å) and contains

  20. Ultrasonic and Thermal Properties of Borate and Phosphate Glasses Containing Bismuth and Lead

    Science.gov (United States)

    Aziz, Sidek Hj. Abd.; Ahmad, Hamezan; Wahab, Zaidan A.; Sulaiman, Zainal Abidin; Talib, Zainal Abidin; Shaari, A. Halim; Senin, H. B.

    2007-05-01

    Systematic series of (B2O3,P2O5)-Bi2O3-PbO glasses have been successfully prepared by using the rapid quenching technique in which each oxide content changes for every series on the basis of its weight percentage. Their amorphous natures were confirmed earlier by the x-ray diffraction technique. The experimental results show that the density of both glasses, determined by using the Archimedes principle, increases with the glass modifier content. This is due to the replacement of Bi2O3 and PbO in the borate and phosphate glassy networks. The molar volume for borate glass increases with the addition of bismuth and lead oxides, but a reverse trend occurs for the phosphate glass. The longitudinal and shear ultrasound velocities, determined by the MBS 8000 system, of both lead bismuth borate and phosphate glasses show a decreasing trend as more PbO and Bi2O3 are added to the glass system. The increase in PbO/Bi2O3 content was probably related to the progressive increase in the concentration of non-bridging oxygen (NBOs). Thermal studies of the glass, using the Labsys DTA-Setaram machine, show that the value of the glass transition temperature (Tg) is closely related to the chemical bond in the system. In lead bismuth borate glasses, the addition of more Pb2+ and Bi3+ results in a more dominant ionic bond character in the system and hence decreases Tg of the sample. However, in lead bismuth phosphate glasses, the addition of Pb2+ and Bi3+ not only failed to weaken the covalent character in P-O-P bonds, but strengthened it further, leading to an increment in the values of Tg.

  1. Structural studies of lead lithium borate glasses doped with silver oxide

    Science.gov (United States)

    Coelho, João; Freire, Cristina; Hussain, N. Sooraj

    2012-02-01

    Silver oxide doped lead lithium borate (LLB) glasses have been prepared and characterized. Structural and composition characterization were accessed by XRD, FTIR, Raman, SEM and EDS. Results from FTIR and Raman spectra indicate that Ag 2O acts as a network modifier even at small quantities by converting three coordinated to four coordinated boron atoms. Other physical properties, such as density, molar volume and optical basicity are also evaluated. Furthermore, they are also affected by the silver oxide composition.

  2. Spectroscopic studies of lead antimony borate glasses doped with erbium ions

    Science.gov (United States)

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

    2013-06-01

    Antimony borate glasses of the composition 30PbO-25Sb2O3-(45-x)B2O3-xEr2O3 with x = 0 to 1.0 in steps of 0.2 were prepared by the melt-quenching method. Various physical parameters. radiative parameters, transition probability A, branching ratio β and the radiative life time τ for different emission levels of Er3+ ions, have been evaluated.

  3. The prediction of borate mineral equilibria in natural waters: Application to Searles Lake, California

    Science.gov (United States)

    Felmy, Andrew R.; Weare, John H.

    1986-12-01

    The chemical equilibrium model of HARVIEet al. (1984) has been extended to include borate species. The model is based upon the semi-empirical equations of PITZER (1973) and coworkers and is valid to high ionic strength (≈14 m) and high borate concentration. Excellent agreement with the existing emf, isopiestic and solubility data in the system (Na-K-Ca-Mg-H-Cl-SO4-CO2-B(OH)4-H2O) is obtained. Calculated mineral solubilities are in general within 10% of their experimental values, even at high ionic strengths. The model was applied to the multicomponent, high ionic strength (I ~ 10) and high borate concentration (BT ~ 0.5 m) Searles Lake evaporite deposit. Utilizing the chemical composition of the interstitial brine, the model predicts equilibrium between the brine and only those minerals which are known to be in contact with the brine. These calculations clearly demonstrate the applicability of the model to high ionic strength, high borate concentration natural waters. The model was also utilized to calculate the mineral sequences which should result from evaporation of the major source of water for Searles Lake, the Owens River. The geochemical conditions necessary for the formation of the most recent mud and saline units are examined. The final results indicate that the mineral sequences found in the most recent saline unit in Searles Lake can be produced by evaporation of a water close in composition to present Owens River water, provided primary dolomite formation is delayed and back reaction between the Parting Mud and the Upper Salt is inhibited.

  4. 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.

  5. Synthesis of zwitterionic cobaltocenium borate and borata-alkene derivatives from a borole-radical anion.

    Science.gov (United States)

    Bauer, Jürgen; Braunschweig, Holger; Hörl, Christian; Radacki, Krzysztof; Wahler, Johannes

    2013-09-27

    Chemical single-electron reduction of 1-mesityl-2,3,4,5-tetraphenylborole (3) gave a stable radical anion [CoCp*2 ][3] as shown in earlier investigations. Herein, we present the reaction of [CoCp*2 ][3] with the 2,2,6,6-tetramethylpiperidine-N-oxyl radical (TEMPO), a common radical trap. Instead of radical recombination, the reaction proceeds through a redox pathway involving oxidation of the borole radical anion combined with reduction of TEMPO. This electron-transfer process is accompanied by a deprotonation reaction of the cobaltocenium counterion by the base TEMPO(-) to give TEMPO-H and a neutral cobalt(I) fulvene complex (7). The latter was not observed directly during the reaction, because it instantaneously reacts as a nucleophile attacking at the boron center of the in situ generated borole 3 to give the borate 6. However, 7 was synthesized independently by deprotonation of [CoCp*2 ][PF6 ]. In addition, the obtained zwitterionic cobaltocenium borate 6 undergoes a photolytic rearrangement to form the borata-alkene derivative 9 that thermally transforms to the chiral cobaltocenium borate 12. Our investigations are based on spectroscopic evidence, X-ray crystallography, elemental analysis, as well as DFT calculations. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. In vitro evaluation of cytotoxicity of silver-containing borate bioactive glass.

    Science.gov (United States)

    Luo, Shi-Hua; Xiao, Wei; Wei, Xiao-Juan; Jia, Wei-Tao; Zhang, Chang-Qing; Huang, Wen-Hai; Jin, Dong-Xu; Rahaman, Mohamed N; Day, Delbert E

    2010-11-01

    The cytotoxicity of silver-containing borate bioactive glass was evaluated in vitro from the response of osteoblastic and fibroblastic cells in media containing the dissolution products of the glass. Glass frits containing 0-2 weight percent (wt %) Ag were prepared by a conventional melting and quenching process. The amount of Ag dissolved from the glass into a simulated body fluid (SBF), measured using atomic emission spectroscopy, increased rapidly within the first 48 h, but slowed considerably at longer times. Structural and microchemical analysis showed that the formation of a hydroxyapatite-like layer on the glass surface within 14 days of immersion in the SBF. The response of MC3T3-E1 and L929 cells to the dissolution products of the glass was evaluated using SEM observation of cell morphology, and assays of MTT hydrolysis, lactate dehydrogenase release, and alkaline phosphatase activity after incubation for up to 48 h. Cytotoxic effects were found for the borate glass containing 2 wt % Ag, but not for 0.75 and 1 wt % Ag. This borate glass containing up to ∼1 wt % Ag could provide a coating material for bacterial inhibition and enhanced bioactivity of orthopaedic implant materials such as titanium.

  7. Compositional-dependent lead borate based glasses doped with Eu3+ ions: Synthesis and spectroscopic properties

    Science.gov (United States)

    Pisarski, W. A.; Pisarska, J.; Dominiak-Dzik, G.; Mączka, M.; Ryba-Romanowski, W.

    2006-12-01

    New multicomponent lead borate based glasses with various PbO/B2O3 weight ratio were prepared. The glass samples were analyzed in detail by using Raman and IR absorption spectroscopy. Optical properties of Eu3+ ions have been investigated in lead borate based systems, in which PbO/B2O3 weight ratios were changed from 1:2 to 8:1 in glass composition. The values of the phonon energy of the host and 5D0 lifetime of Eu3+ decrease, whereas absorption and emission intensities, as well as bonding parameter increase with increasing PbO concentration. Additionally, spectral lines are shifted in direction to the lower frequency region. Non-monotonic dependence of the fluorescence intensity ratio R (5D0 7F2/5D0 7F1) upon PbO/B2O3 content has been observed in contrast to bonding parameter that is also non-linear but monotonic. Some structural and spectroscopic aspects for Eu-doped lead borate based glasses are presented.

  8. VO 2+ 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-B 2O 3) glass system have been studied. EPR spectra of all the glass samples exhibit resonance signals characteristic of VO 2+ ions. The values of spin-Hamiltonian parameters indicate that the VO 2+ ions in zinc lead borate glasses were present in octahedral sites with tetragonal compression and belong to C 4V symmetry. The spin-Hamiltonian parameters g and A are found to be independent of V 2O 5 content and temperature but changing with ZnO content. The decrease in Δ g∥/Δ g⊥ value with increase in ZnO content indicates that the symmetry around VO 2+ ions is more octahedral. The decrease in intensity of EPR signal above 10 mol% of V 2O 5 is attributed to a fall in the ratio of the number of V 4+ ions ( N4) to the number of V 5+ ions ( N5). The number of spins ( N) participating in resonance was calculated as a function of temperature for VO 2+ 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/ χ- T graph. The optical absorption spectra show single absorption band due to VO 2+ ions in tetragonally distorted octahedral sites.

  9. Laser spectroscopy of Nd 3+ and Dy 3+ ions in lead borate glasses

    Science.gov (United States)

    Pisarska, Joanna; Pisarski, Wojciech A.; Ryba-Romanowski, Witold

    2010-07-01

    The spectroscopic and laser properties of Nd 3+ and Dy 3+ ions in lead borate glass were studied. Luminescence spectra recorded in the near-infrared and visible ranges correspond to 4F 3/2- 4I J/2 ( J=9, 11, 13) transitions of Nd 3+ and 4F 9/2- 6H J/2 ( J=11, 13, 15) transitions of Dy 3+, respectively. Luminescence decay curves were analyzed as a function of activator concentration. Luminescence quenching is observed, which is due to Ln-Ln interaction increasing. Several spectroscopic parameters relevant to laser potential of Ln 3+ ions (Ln=Nd, Dy) in lead borate glass were determined. The relatively large values of the quantum efficiency and the room-temperature emission cross-section for the 4F 3/2- 4I 11/2 transition of Nd 3+ at 1061 nm and the 4F 9/2- 6H 13/2 transition of Dy 3+ at 573 nm imply that Ln-doped lead borate glasses can be considered as promising solid-state materials for laser applications.

  10. Borate glasses with high lanthanide oxids solubility for the cold crucible induction melter(CCIM) applications

    Energy Technology Data Exchange (ETDEWEB)

    Kim, M.; Heo, J. [POSTECH, Pohang (Korea, Republic of)

    2016-05-15

    Pyro-processing is being investigated to reuse radioactive uranium and trans-uranium elements from the spent fuels. Previous researches regarding waste forms for rare-earth oxides waste generated from pyro-processing reported low elemental release (< 10{sup 4} g/m2) of RE ions at the product consistency test (PCT). Current work reports the continuing effort on the enhancement of the waste loading and process-ability using cold crucible induction melter(CCIM). Borate glasses are well-known for their low melting temperatures with high rare-earth oxide solubility compared to silicate glasses. Borate glasses were investigated as potential waste forms with high waste loading for immobilization of lanthanide ion wastes produced by pyro-processing. Process-ability of them was investigated by characterizing several important processing parameters for cold crucible induction melter (CCIM) process. Borate glasses containing 0 - 20 mol% Nd{sub 2}O{sub 3} were fabricated by melting the starting powders at 1300 .deg. C for 30 min with maximum loading of 56.8 wt % (22 mol %). The released concentration of Nd were < 0.1 ppm. Crystallization did not appear at the temperature below 800 .deg. C. Viscosity and electric conductivity of these glasses meet requirements to apply to CCIM.

  11. 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.

  12. 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.

  13. Enhancing mechanical properties of ceramic papers loaded with zeolites using borate compounds as binders

    Directory of Open Access Journals (Sweden)

    Juan P. Cecchini

    2013-02-01

    Full Text Available NaY zeolite-containing ceramic papers were prepared by a papermaking technique with a dual polyelectrolyte retention system that implied the use of cationic and anionic polymers. To improve their mechanical properties, we found that some borate compounds could be successfully used as ceramic binders. Three types of sodium and/or calcium borates were tested as binders: colemanite, nobleite, and anhydrous ulexite. The improvement in the mechanical properties depends both on the borate used and on the calcination temperature. By XRD it was determined that the faujasite structure collapsed after calcination at 700°C, which limited the final calcination temperature of zeolitic ceramic papers. Different amounts of NaY zeolite were added to ceramic papers and, as observed by SEM, faujasite particles were well distributed throughout the ceramic paper structure. Ceramic papers containing 1.2 wt.% zeolite after calcination at 650°C resulted in structured catalysts that were easy-to-handle, and which can be adapted to different conformations.

  14. Protonolysis and thermolysis reactions of functionalised NHC-carbene boranes and borates.

    Science.gov (United States)

    Arnold, Polly L; Bell, Nicola L; Marr, Isobel H; She, Siyi; Hamilton, Jonathan; Fraser, Craig; Wang, Kai

    2014-11-07

    A set of β-ketoimidazolium and β-ketoimidazolinium salts of the general formula [R(1)C(O)CH2{CH[NCR(3)CR(3)N(R(2))]}]X (R(1) = (t)Bu, naphth; R(2) = (i)Pr, Mes, (t)Bu; R(3) = H, Me, (H)2; X = Cl, Br) show contrasting reactivity with superhydride bases MHBEt3; two are reduced to chiral β-alcohol carbene-boranes R(1)CH(OH)CH2{C(BEt3)[NCR(3)CR(3)N(R(2))]} 2 (R(1) = (t)Bu; R(2) = (i)Pr, Mes; R(3) = H), two with bulky R(2) substituents are reduced to chiral β-borate imidazolium salts [R(1)CH(OBEt3)CH2{CH[NCR(3)CR(3)N(R(2))]}]X 3 (R(1) = (t)Bu, naphth; R(2) = Mes, (t)Bu; R(3) = H, Me; X = Cl, Br), and the two saturated heterocycle derivatives remain unreduced but form carbene-borane adducts R(1)C(O)CH2{C(BEt3)[NCR(3)CR(3)N(R(2))]} 4 (R(1) = (t)Bu, naphth; R(2) = Mes; R(3) = (H)2). Heating solutions of the imidazolium borates 3 results in the elimination of ethane, in the first example of organic borates functioning as Brønsted bases and forming carbene boranes R(1)CH(OBEt2)CH2{C[NCR(3)CR(3)N(R(2))]} 5 (R(1) = naphth; R(2) = Mes; R(3) = Me). The 'abnormal' carbene borane of the form 2 R(1)CH(OH)CH2{CH[NC(BEt3)CR(3)N(R(2))]} (R(1) = (t)Bu; R(2) = (t)Bu; R(3) = H), is also accessible by thermolysis of 3, suggesting that the carbene-borane alcohol is a more thermodynamically stable combination than the zwitterionic imidazolium borate. High-temperature thermolysis also can result in complete cleavage of the alcohol arm, eliminating tert-butyloxirane and forming the B-N bound imidazolium borate 7. The strong dependence of reaction products on the steric and electronic properties of each imidazole precursor molecule is discussed.

  15. Calibration of the borated ion chamber at NIST reactor thermal column.

    Science.gov (United States)

    Wang, Z; Hertel, N E; Lennox, A

    2007-01-01

    In boron neutron capture therapy and boron neutron capture enhanced fast neutron therapy, the absorbed dose of tissue due to the boron neutron capture reaction is difficult to measure directly. This dose can be computed from the measured thermal neutron fluence rate and the (10)B concentration at the site of interest. A borated tissue-equivalent (TE) ion chamber can be used to directly measure the boron dose in a phantom under irradiation by a neutron beam. Fermilab has two Exradin 0.5 cm(3) Spokas thimble TE ion chambers, one loaded with boron, available for such measurements. At the Fermilab Neutron Therapy Facility, these ion chambers are generally used with air as the filling gas. Since alpha particles and lithium ions from the (10)B(n,alpha)(7)Li reactions have very short ranges in air, the Bragg-Gray principle may not be satisfied for the borated TE ion chamber. A calibration method is described in this paper for the determination of boron capture dose using paired ion chambers. The two TE ion chambers were calibrated in the thermal column of the National Institute of Standards and Technology (NIST) research reactor. The borated TE ion chamber is loaded with 1,000 ppm of natural boron (184 ppm of (10)B). The NIST thermal column has a cadmium ratio of greater than 400 as determined by gold activation. The thermal neutron fluence rate during the calibration was determined using a NIST fission chamber to an accuracy of 5.1%. The chambers were calibrated at two different thermal neutron fluence rates: 5.11 x 10(6) and 4.46 x 10(7)n cm(-2) s(-1). The non-borated ion chamber reading was used to subtract collected charge not due to boron neutron capture reactions. An optically thick lithium slab was used to attenuate the thermal neutrons from the neutron beam port so the responses of the chambers could be corrected for fast neutrons and gamma rays in the beam. The calibration factor of the borated ion chamber was determined to be 1.83 x 10(9) +/- 5.5% (+/- 1sigma) n

  16. In vitro stimulation of vascular endothelial growth factor by borate-based glass fibers under dynamic flow conditions.

    Science.gov (United States)

    Chen, Sisi; Yang, Qingbo; Brow, Richard K; Liu, Kun; Brow, Katherine A; Ma, Yinfa; Shi, Honglan

    2017-04-01

    Bioactive borate glass has been recognized to have both hard and soft tissue repair and regeneration capabilities through stimulating both osteogenesis and angiogenesis. However, the underlying biochemical and cellular mechanisms remain unclear. In this study, dynamic flow culturing modules were designed to simulate the micro-environment near the vascular depletion and hyperplasia area in wound-healing regions, thus to better investigate the mechanisms underlying the biocompatibility and functionality of borate-based glass materials. Glass fibers were dosed either upstream or in contact with the pre-seeded cells in the dynamic flow module. Two types of borate glasses, doped with (1605) or without (13-93B3) CuO and ZnO, were studied along with the silicate-based glass, 45S5. Substantial fiber dissolution in cell culture medium was observed, leading to the release of ions (boron, sodium and potassium) and the deposition of a calcium phosphate phase. Different levels of vascular endothelial growth factor secretion were observed from cells exposed to these three glass fibers, and the copper/zinc containing borate 1605 fibers exhibited the most positive influence. These results indicate that dynamic studies of in vitro bioactivity provide useful information to understand the in vivo response to bioactive borate glasses. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Development of Natural Anthocyanin Dye-Doped Silica Nanoparticles for pH and Borate-Sensing Applications

    Science.gov (United States)

    Ha, Chu T.; Lien, Nghiem T. Ha; Anh, Nguyen D.; Lam, Nguyen L.

    2017-08-01

    Anthocyanin belongs to a large group of phenolic compounds called flavonoids. It is found primarily in fruits, flowers, roots and other parts of higher plants. Within the black carrot, it has been found that the cyanidin component 1,2 diol was the major anthocyanine. Since the terminal thiols potentially display chemical interactions with borate additives, anthocyanin from the black carrot can act as a sensing material for detecting borate in the environment. As a natural dye, anthocyanin responds to pH change of the medium. Here, we present an application of black carrot dyes for pH sensing and for the detection of borate additives within meats. The dyes were encapsulated within a mesoporous silica (SiO2) matrix in order to prevent the sensing materials from dissolution into the aqueous medium. The encapsulation was done in situ during preparation of silica nanoparticles (size from 100 nm to 500 nm) following an advanced Stöber method. These anthocyanin-encapsulated silica nanoparticles show a clear color change from green in an aqueous solution free of borate to GRAY-red in the presence of borate additive and red (pH 2) to green (pH 10).

  18. HP-CsB5O8 : synthesis and characterization of an outstanding borate exhibiting the simultaneous linkage of all structural units of borates.

    Science.gov (United States)

    Sohr, Gerhard; Többens, Daniel M; Schmedt Auf der Günne, Jörn; Huppertz, Hubert

    2014-12-15

    The new cesium pentaborate HP-CsB5 O8 is synthesized under high-pressure/high-temperature conditions of 6 GPa and 900 °C in a Walker-type multianvil apparatus. The compound crystallizes in the orthorhombic space group Pnma (Z=4) with the parameters a=789.7(1), b=961.2(1), c=836.3(1) pm, V=0.6348(1) nm(3) , R1 =0.0359 and wR2 =0.0440 (all data). The new structure type of HP-CsB5 O8 exhibits the simultaneous linkage of trigonal BO3 groups, corner-sharing BO4 tetrahedra, and edge-sharing BO4 tetrahedra including the presence of threefold-coordinated oxygen atoms. With respect to the rich structural chemistry of borates, HP-CsB5 O8 is the second structure type possessing this outstanding combination of the main structural units of borates in one compound. The structure consists of corrugated chains of corner- and edge-sharing BO4 tetrahedra interconnected through BO3 groups forming octagonal channels. Inside these channels, cesium is 13+3-fold coordinated by oxygen atoms. (11) B MQMAS NMR spectra are analyzed to estimate the isotropic chemical shift values and quadrupolar parameters. IR and Raman spectra are obtained and compared to the calculated vibrational frequencies at the Γ-point. The high-temperature behavior is examined by means of temperature-programmed powder diffraction.

  19. 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.

  20. Infrared and Raman spectroscopic studies on alkali borate glasses: evidence of mixed alkali effect.

    Science.gov (United States)

    Padmaja, G; Kistaiah, P

    2009-03-19

    A lithium-potassium-borate glass system containing manganese and iron cations has been thoroughly investigated in order to obtain information about the mixed alkali effect and the structural role of both the manganese and iron in such glass hosts. Mixed alkali borate glasses of the (30 - x)Li(2)O - xK(2)O - 10CdO/ZnO - 59B(2)O(3) (x = 0, 10, 15, 20, and 30) doped with 1MnO(2)/1Fe(2)O(3) system were prepared by a melt quench technique. The amorphous phase of the prepared glass samples was confirmed from their X-ray diffraction. The spectroscopic properties of glass samples were studied using infrared (IR) and Raman spectroscopic techniques. The density of all the prepared glasses was measured using Archimedes principle. Molar volumes were estimated from the density data. IR spectra of these glasses revealed a dramatic variation of three- and four-coordinated boron structures as a function of mixed alkali concentration. The vibrations due to Li-O, K-O, and MnO(4)/FeO(4) arrangements are consistent in all the compositions and show a nonlinear variation in the intensity with alkali content. Raman spectra of different alkali combinations with CdO and ZnO present drastic changes in the intensity of various Raman bands. The observation of disappearance and reappearance of IR and Raman bands as a function of various alkali concentrations is an important result pertaining to the mixed alkali effect in borate glasses. Acting as complementary spectroscopic techniques, both types of measurements, IR and Raman, revealed that the network structure of the studied glasses is mainly based on BO(3) and BO(4) units placed in different structural groups, the BO(3) units being dominant. The measured IR and Raman spectra of different glasses are used to clarify the optical properties of the present glasses correlating them with their structure and composition.

  1. Energy transfer and luminescence studies of Pr 3+ , Yb 3+ co-doped lead borate glass

    Science.gov (United States)

    Wen, Hongli; Tanner, Peter A.

    2011-09-01

    Lead borate glass samples doped with the tripositive lanthanide ions Pr 3+ and Yb 3+ were synthesized by the conventional melting-quenching method. The luminescence properties and energy transfer process from Pr 3+ to Yb 3+ were investigated. Upon ultraviolet excitation, the room temperature luminescence decay curve of a sample containing only a low concentration of Pr 3+ exhibited monoexponential decay from 1D 2 with the lifetime 37 μs, without emission from 3P 0. The room temperature Pr 3+ emission intensity decreased with the increase of Yb 3+ mole ratio in the glass. Under the excitation of 454.5 nm at 10 K, a broad red emission band centered at 605 nm, and an NIR emission band at 995 nm were observed in the co-doped lead borate glass, originating from Pr 3+ and Yb 3+ ions, respectively. The decay curves of the 1D 2 emission from Pr 3+ with addition of Yb 3+ in lead borate glass show non-monoexponential character, and are best described by a stretched exponential function. The average 1D 2 decay time decreases considerably with the addition of Yb 3+ in the glass. Decay curve fitting using a modified Inokuti-Hirayama expression indicates dipole-dipole energy transfer from Pr 3+ to Yb 3+, which is consistent with the expected cross-relaxation scheme. There is a good agreement of the estimated overall energy transfer efficiency obtained from the integrals under the normalized decay curves, or from the lifetimes fitted by the stretched exponential function, or from the average decay times.

  2. Compositional dependence of optical band gap and refractive index in lead and bismuth borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Mallur, Saisudha B.; Czarnecki, Tyler; Adhikari, Ashish; Babu, Panakkattu K.

    2015-08-15

    Highlights: • Refractive indices increase with increasing PbO/Bi{sub 2}O{sub 3} content. • Optical band gap arises due to direct forbidden transition. • Optical band gaps decrease with increasing PbO/Bi{sub 2}O{sub 3} content. • New empirical relation between the optical band gap and the refractive index. - Abstract: We prepared a series of lead and bismuth borate glasses by varying PbO/Bi{sub 2}O{sub 3} content and studied refractive index and optical band gap as a function of glass composition. Refractive indices were measured very accurately using a Brewster’s angle set up while the optical band gaps were determined by analyzing the optical absorption edge using the Mott–Davis model. Using the Lorentz–Lorentz method and the effective medium theory, we calculated the refractive indices and then compared them with the measured values. Bismuth borate glasses show better agreement between the calculated values of the refractive index and experimental values. We used a differential method based on Mott–Davis model to obtain the type of transition and optical band gap (E{sub opt}) which in turn was compared with the value of E{sub opt} obtained using the extinction coefficient. Our analysis shows that in both lead and bismuth borate glasses, the optical band gap arises due to direct forbidden transition. With increasing PbO/Bi{sub 2}O{sub 3} content, the absorption edge shifts toward longer wavelengths and the optical band gap decreases. This behavior can be explained in terms of changes to the Pb−O/Bi−O chemical bonds with glass composition. We obtained a new empirical relation between the optical band gap and the refractive index which can be used to accurately determine the electronic oxide polarizability in lead and bismuth oxide glasses.

  3. Gamma rays interactions with WO{sub 3}-doped lead borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    ElBatal, H.A. [Glass Research Department, National Research Center, Dokki, Cairo (Egypt); Abdelghany, A.M., E-mail: a.m_abdelghany@yahoo.com [Spectroscopy Department, Physics Division, National Research Center, Dokki, Cairo (Egypt); ElBatal, F.H. [Glass Research Department, National Research Center, Dokki, Cairo (Egypt); EzzElDin, F.M. [National Center for Radiation Research and Technology, Nasr City, Cairo (Egypt)

    2012-05-15

    Highlights: Black-Right-Pointing-Pointer Some ternary borate glasses of varying compositions were prepared. Black-Right-Pointing-Pointer Effect of successive gamma ray irradiation in prepared glass structure was studied. Black-Right-Pointing-Pointer FTIR, UV measurement before and after successive gamma irradiation were studied. Black-Right-Pointing-Pointer UV spectra reveal some changes with different gamma doses, which are discussed. - Abstract: Optical and FT infrared spectral properties of tungsten ions in a host lead borate glass with composition PbO 55%, B{sub 2}O{sub 3} 45% (wt%) were studied. The same spectral properties were re-measured after subjecting the samples to successive gamma irradiation. The work was undertaken to justify the state of tungsten ions in such glass system by combined spectral investigations. Optical and FTIR spectral studies were confirmed by investigating electron spin resonance (ESR) of the undoped and WO{sub 3}-doped samples before and after gamma irradiation. The optical spectrum of the undoped glass exhibits strong and wide UV absorption bands, which are related to the combined UV spectra of trace iron impurities (Fe{sup 3+} ions) and that from divalent lead (Pb{sup 2+}) ions. Optical studies of WO{sub 3}-doped sample indicate the presence of tungsten ions mostly in the hexavalent W{sup 6+} state. The presence of tungsten ions as structural groups was obtained by comparing the FTIR spectra of the undoped and WO{sub 3}-doped samples. ESR spectra confirm the optical and FTIR spectral studies. The studied host lead borate glass has been found to show obvious shielding behavior towards successive gamma irradiation as revealed by the constancy of optical absorption spectral curves.

  4. 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.

  5. 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.

  6. 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.

  7. Electrochemical characterization of electrolytes for lithium-ion batteries based on lithium difluoromono(oxalato)borate

    Energy Technology Data Exchange (ETDEWEB)

    Zugmann, Sandra; Moosbauer, Dominik; Amereller, Marius; Schreiner, Christian; Wudy, Franz; Gores, Heiner Jakob [Workgroup ' ' Electrochemistry and Electrolytes' ' , Institute of Physical and Theoretical Chemistry, University of Regensburg, Universtaetsstr. 31, D-93040 Regensburg, Bavaria (Germany); Schmitz, Rene; Schmitz, Raphael; Isken, Philipp; Dippel, Christian; Mueller, Romek; Kunze, Miriam; Lex-Balducci, Alexandra; Winter, Martin [Institute of Physical Chemistry, Westfaelische Wilhelms-University Muenster, Corrensstrasse 28/30, 48149 Muenster (Germany)

    2011-02-01

    The salt lithium difluoromono(oxalato)borate (LiDFOB) showed some promising results for lithium-ion-cells. It was synthesized via a new synthetic route that avoids chloride impurities. Here we report the properties of its solutions solvent blend ethylene carbonate/diethyl carbonate (3:7, mass ratio), including its conductivity, cationic transference number, hydrolysis, Al-current collector corrosion-protection ability and its cycling performance with some electrode materials. Some Al-corrosion studies were also performed with the help of our recently developed computer controlled impedance scanning electrochemical quartz crystal microbalance (EQCM) that proofed to be a useful tool for battery material investigations. (author)

  8. Lithium tri borate (LiB3O5) embedded polymer electret for mechanical sensing application

    Science.gov (United States)

    Murugan, S.; Praveen, E.; Prasad, M. V. N.; Jayakumar, K.

    2017-05-01

    Lithium tri borate (LiB3O5) particles were synthesized by precipitation assisted high temperature solid state reaction. The particles were embedded in chitosan polymer and used as an electret. This electret was characterized for the suitability as a sensing element in vibration accelerometer. It is observed that LiB3O5 embedded electret exhibiting piezoelectric property. The electret is also giving an isolation of > 999 MΩ at 100 Vdc, 250 Vdc, 500 Vdc and 1kVdc confirms compatible for intrinsically safe sensing alternative in vibration accelerometer.

  9. Growth of new borate crystals with fiber shape by the micro-pulling down technique

    Science.gov (United States)

    Assi, Farah; Ferriol, Michel; Aillerie, Michel; Cochez, Marianne

    2017-07-01

    Borate-based materials are of high interest to generate an UV laser light from a crystal. Fiber-shaped crystals combining the advantages of fiber lasers and crystalline lasers, we have investigated the growing conditions required to obtain usable fibers of Bi2ZnB2O7 (BZBO) and LaBGeO5 (LBGO). For BZBO, the major drawback was the pronounced color of the fibers and for LBGO, it was the high viscosity of its melt leading to use a flux. This paper presents our state of the art to obtain good quality BZBO and LBGO crystal fibers.

  10. 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...

  11. 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.

  12. 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.

  13. The new silver borate Ag{sub 3}B{sub 5}O{sub 9}

    Energy Technology Data Exchange (ETDEWEB)

    Sohr, Gerhard; Falkowski, Viktoria; Huppertz, Hubert, E-mail: hubert.huppertz@uibk.ac.at

    2015-05-15

    Single crystals of Ag{sub 3}B{sub 5}O{sub 9} were obtained via high-pressure synthesis at 3 GPa and 600 °C, using a Walker-type multianvil high-pressure device. Ag{sub 3}B{sub 5}O{sub 9} crystalizes with a=674.7(2), b=943.5(2), c=1103.5(2) pm, V=0.7025(2) nm{sup 3}, and Z=4 in the noncentrosymmetric space group P2{sub 1}2{sub 1}2{sub 1} (no. 19). The orthorhombic structure was refined from 3740 independent reflections with R1=0.0496 and wR2=0.587 (all data). It is built up from infinite corner-sharing chains of BO{sub 4} tetrahedra along the a axis, which are interconnected by BO{sub 3} groups to form a network. In the structure, three crystallographically independent sites are occupied with Ag{sup +} cations exhibiting argentophillic interactions. The synthetic conditions as well as the results of the single crystal structure analysis are presented. - Graphical abstract: Noncentrosymmetric silver borate: During investigations in the system Ag–B–O, a new noncentrosymmetric silver borate Ag{sub 3}B{sub 5}O{sub 9} was discovered. The new structure type is built up from corner-sharing BO{sub 3} and BO{sub 4} groups, forming a network. Argentophillic interactions are clearly indicated by the Ag{sup +}⋯Ag{sup +} distances present in the structure. - Highlights: • A noncentrosymmetric borate Ag{sub 3}B{sub 5}O{sub 9} is accessible via high-pressure synthesis. • Ag{sub 3}B{sub 5}O{sub 9} is the second high-pressure silver borate. • Ag{sup +}⋯Ag{sup +} distances in Ag3B5O9 clearly indicate the presence of argentophillic interactions.

  14. 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.

  15. An electrochemical study of tin oxide thin film in borate buffer solutions

    Directory of Open Access Journals (Sweden)

    Díaz Raül

    2003-01-01

    Full Text Available The electrochemical behavior of tin polycrystals in borate buffer solutions at pH 7.5 was systematically investigated using cyclic voltammetry, EC-STM and electrochemical impedance measurements. A systematic shift to more negative values of the potentials corresponding either to the major reduction peak either to the hydrogen evolution was measured when the anodization potential used for film growth was increased. A discussion about the different oxides there formed was included and a reassignation of tin oxidation and tin oxides reduction processes was given.

  16. Femtosecond broadband fluorescence spectroscopy by down- and up-conversion in β-barium borate crystals

    Science.gov (United States)

    Sajadi, M.; Quick, M.; Ernsting, N. P.

    2013-10-01

    Broadband transient fluorescence spectroscopy is performed by difference- and sum-frequency generation in β-barium borate crystals at a fixed geometry. Phase matching is spectrally broadened by using (i) 1340 nm gate pulses, (ii) a fluorescence angle of ˜4° extended at the crystal, and (iii) angular dispersion of the fluorescence in a calcite prism. The latter provides 1° angular separation between the two spectral wings of the fluorescence. By combining down- and up-conversion processes, a 26 000 cm-1 wide multiplex window is realized with ˜100 fs time resolution.

  17. 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

    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......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...

  18. 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.

  19. Structural, optical and glass transition studies on Nd{sup 3+}-doped lead bismuth borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Karthikeyan, B.; Mohan, S

    2003-07-01

    Nd{sup 3+}-doped lead bismuth borate (PbO-Bi{sub 2}O{sub 3}-B{sub 2}O{sub 3}) glasses were prepared with different concentrations of Nd{sup 3+}. 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 [BiO{sub 3}], BO{sub 4}, BO{sub 3} and PbO{sub 4} units as the local structures.

  20. Absorption of light by lead silicate borate glasses containing gadolinium tellurite

    Energy Technology Data Exchange (ETDEWEB)

    Ivanchenko, L.A.; Obolonchik, V.A.; Ovcharenko, N.V.; Frankfurt, V.M.; Serdyuk, V.A.; Zaletilo, L.S.

    1987-03-01

    The authors investigate how the properties of lead silicate borate glasses change when rare-earth tellurites are added to them. The choice of glasses based on PbO was prompted by the fact that they are low-melting and will dissolve large amounts of compounds of type Ln/sub 2/Te/sub 3/O/sub 9/. The compositions of the resultant glasses are shown. The refractive indices and absorption edge in the visible region of the spectrum is also presented. The dependences of the absorptive index of glasses in both visible and in IR regions are shown, as is the reflection spectra in the IR.

  1. Optical properties of lead borate glasses containing Dy{sup 3+} ions

    Energy Technology Data Exchange (ETDEWEB)

    Pisarska, Joanna [Department of Materials Science, Silesian University of Technology, Krasinskiego 8, 40-019 Katowice (Poland)], E-mail: Joanna.Pisarska@polsl.pl

    2009-07-15

    Optical properties of lead borate glasses containing Dy{sup 3+} ions were examined using absorption and luminescence measurements and theoretical calculations based on the Judd-Ofelt framework and the Inokuti-Hirayama model. The luminescence spectra show two characteristic bands at 480 and 573 nm, which are due to {sup 4}F{sub 9/2}-{sup 6}H{sub 15/2} (blue) and {sup 4}F{sub 9/2}-{sup 6}H{sub 13/2} (yellow) transitions of trivalent Dy{sup 3+} ions. The yellow/blue luminescence and its decay were analyzed as a function of activator concentration.

  2. Electrochemical characterization of electrolytes for lithium-ion batteries based on lithium difluoromono(oxalato)borate

    Science.gov (United States)

    Zugmann, Sandra; Moosbauer, Dominik; Amereller, Marius; Schreiner, Christian; Wudy, Franz; Schmitz, René; Schmitz, Raphael; Isken, Philipp; Dippel, Christian; Müller, Romek; Kunze, Miriam; Lex-Balducci, Alexandra; Winter, Martin; Gores, Heiner Jakob

    The salt lithium difluoromono(oxalato)borate (LiDFOB) showed some promising results for lithium-ion-cells. It was synthesized via a new synthetic route that avoids chloride impurities. Here we report the properties of its solutions (solvent blend ethylene carbonate/diethyl carbonate (3:7, mass ratio), including its conductivity, cationic transference number, hydrolysis, Al-current collector corrosion-protection ability and its cycling performance with some electrode materials. Some Al-corrosion studies were also performed with the help of our recently developed computer controlled impedance scanning electrochemical quartz crystal microbalance (EQCM) that proofed to be a useful tool for battery material investigations.

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

    Energy Technology Data Exchange (ETDEWEB)

    Gheno, Giulia, E-mail: giulia.gheno@unive.it [Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari di Venezia, Dorsoduro 2137, 30123 Venezia (Italy); Bortoluzzi, Marco; Ganzerla, Renzo [Dipartimento di Scienze Molecolari e Nanosistemi, Università 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)

    2014-01-15

    The inorganic pigments malachite, Egyptian blue, Ercolano blue and chrome yellow have been doped with the neutral homoleptic Ln(III) complex Ln(Tp){sub 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.

  4. 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.

  5. Influence of the crystal structure on the stability of Ln{sup 2+} in strontium borates

    Energy Technology Data Exchange (ETDEWEB)

    Dotsenko, V.P. [Physico-Chemical Institute, Ukrainian Academy of Sciences, 86 Lustdorfskaya str., 65080 Odesa (Ukraine)], E-mail: ssclab@ukr.net; Berezovskaya, I.V.; Efryushina, N.P. [Physico-Chemical Institute, Ukrainian Academy of Sciences, 86 Lustdorfskaya str., 65080 Odesa (Ukraine); Voloshinovskii, A.S.; Stryganyuk, G.B. [Ivan Franko National University of Lviv, 8 Kyryla i Mefodiya str., 29005 Lviv (Ukraine)

    2007-04-15

    The results of luminescence measurements on Ln (Eu, Yb) doped alkaline earth (M=Ca,Sr) borates M{sub 3}(BO{sub 3}){sub 2}, MB{sub 2}O{sub 4}, M{sub 2}B{sub 5}O{sub 9}X(X=Cl,Br), MB{sub 6}O{sub 10}, MB{sub 4}O{sub 7} after high-temperature annealing in various atmospheres are reported and discussed. The stability of Ln{sup 2+}(Ln=Eu,Yb) is found to increase in the sequence Sr{sub 3}(BO{sub 3}){sub 2}borates.

  6. 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.

  7. 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.

  8. Characterization and optical properties of Pr$_2$O$_3$-doped molybdenum lead-borate glasses

    Indian Academy of Sciences (India)

    SANGEETA B KOLAVEKAR; N H AYACHIT; R V ANAVEKAR

    2017-06-01

    Pr$^{3+}$ doped molybdenum lead-borate glasses with the chemical composition 75PbO−[25–($x+y$)B$_2$O$_3$]–$y$MoO$_3$–$x$Pr$_2$O$_3$ (where $x = 0.5$ and 1.0 mol% and y = 0 and 5 mol%) were prepared by conventional melt-quenching technique. Thermal, optical and structural analyses are carried out using DSC, UV and FTIR spectra. The physical parameters,like glass transition ($T_g$), stability factor ($\\Delta T$), optical energy band gap ($E_{gopt}$), of these glasses have been determined as a function of dopant concentration. The $T_g$ and optical energy gaps of these glasses were found to be in the range of 290–350$^{\\circ}$C and 2.45–2.7 eV, respectively. Stability of the glass doped with Pr$^{3+}$ is found to be moderate ($\\sim$40). The results are discussed using the structural model of Mo–lead-borate glass

  9. 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.

  10. A new low temperature route to uranyl borates with structural variations

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Shijun [Kiel Univ. (Germany). Inst. fuer Geowissenschaften; Chinese Academy of Sciences, Guangzhou (China). Guangzhou Inst. of Geochemistry; Forschungszentrum Juelich GmbH (Germany). Inst. fuer Energie- und Klimaforschung (IEK-6); Wang, Shuao [Notre Dame Univ., IN (United States). Dept. of Civil Engineering and Geological Sciences; Notre Dame Univ., IN (United States). Dept. of Chemistry and Biochememistry; Lawrence Berkeley Lab., Berkeley, CA (United States). Actinide Chemistry Group; California Univ., Berkeley, CA (United States). Dept. of Chemistry; Polinski, Matthew J. [Notre Dame Univ., IN (United States). Dept. of Civil Engineering and Geological Sciences; Notre Dame Univ., IN (United States). Dept. of Chemistry and Biochememistry; Depmeier, Wulf [Kiel Univ. (Germany). Inst. fuer Geowissenschaften; Albrecht-Schmitt, Thomas E. [Florida State Univ., Tallahassee, FL (United States). Dept. of Chemistry and Biochemistry; Alekseev, Evgeny V. [Forschungszentrum Juelich GmbH (Germany). Inst. fuer Energie- und Klimaforschung (IEK-6); RWTH Aachen Univ. (Germany). Inst. fuer Kristallographie

    2013-10-01

    Three new uranyl borates, K(UO{sub 2})(BO{sub 3}) (1), Rb(UO{sub 2})(BO{sub 3}) (2) and Cs(UO{sub 2})(BO{sub 3}) (3) have been prepared using B{sub 2}O{sub 3} fluxes at 1000 C. 1 and 3 can also be synthesized using potassium tetraborate tetrahydrate as a molten flux at 290 C, which provides a new low temperature route to prepare actinide borates. 1 possesses an a-uranophane anion sheet topology identical to that in the previously reported compounds Li(UO{sub 2})(BO{sub 3}) and Na(UO{sub 2})(BO3). 2 and 3 display a new [UO{sub 5}]{sub 1{infinity}} anion topology with a basic building block of edge-sharing dimers comprised of (UO{sub 7}){sub 2} polyhedra. The A(UO{sub 2})(BO{sub 3}) (A = alkali metal) series shows a systematic structural evolution, which will be discussed in the main text. (orig.)

  11. 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.

  12. 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.

  13. 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.)

  14. 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.

  15. Effect of TeO{sub 2} on the elastic moduli of sodium borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Saddeek, Y.B.; Abd El Latif, Lamia

    2004-05-01

    Sodium borate glass containing tellurite as Te{sub x}Na{sub 2-2x}B{sub 4-4x}O{sub 7-5x} with x=0, 0.05, 0.15, 0.25 and 0.35 have been prepared by rapid quenching. Ultrasonic velocity (both longitudinal and shear) measurements have been made using a transducer operated at the fundamental frequency of 4 MHz at room temperature. The density was measured by the conventional Archimedes method. The elastic moduli, the Debye temperature, Poisson's ratio, and the parameters derived from the Makishima-Mackenzie model and the bond compression model have been obtained as a function of TeO{sub 2} content. The monotonic decrease in the velocities and the elastic moduli, and the increase in the ring diameter and the ratio K{sub bc}/K{sub e} as a function of TeO{sub 2} modifier content reveals the loose packing structure, which is attributed to the increase in the molar volume and the reduction in the vibrations of the borate lattice. The observed results confirm that the addition of TeO{sub 2} changes the rigid character of Na{sub 2}B{sub 4}O{sub 7} to a matrix of ionic behaviour bonds (NBOs). This is due to the creation of more and more discontinuities and defects in the glasses, thus breaking down the borax structure.

  16. New High-Pressure Gallium Borate Ga2B3O7(OH) with Photocatalytic Activity.

    Science.gov (United States)

    Vitzthum, Daniela; Schauperl, Michael; Strabler, Christof M; Brüggeller, Peter; Liedl, Klaus R; Griesser, Ulrich J; Huppertz, Hubert

    2016-01-19

    The new high-pressure gallium borate Ga2B3O7(OH) was synthesized in a Walker-type multianvil apparatus under high-pressure/high-temperature conditions of 10.5 GPa and 700 °C. For the system Ga-B-O-H, it is only the second known compound next to Ga9B18O33(OH)15·H3B3O6·H3BO3. The crystal structure of Ga2B3O7(OH) was determined by single-crystal X-ray diffraction data collected at room temperature. Ga2B3O7(OH) crystallizes in the orthorhombic space group Cmce (Z = 8) with the lattice parameters a = 1050.7(2) pm, b = 743.6(2) pm, c = 1077.3(2) pm, and V = 0.8417(3) nm(3). Vibrational spectroscopic methods (Raman and IR) were performed to confirm the presence of the hydroxyl group. Furthermore, the band gap of Ga2B3O7(OH) was estimated via quantum-mechanical density functional theory calculations. These results led to the assumption that our gallium borate could be a suitable substance to split water photocatalytically, which was tested experimentally.

  17. In situ derivatization of metals and organometallics using borate reagents in gas chromatographic speciation studies.

    Science.gov (United States)

    Zachariadis, George A

    2013-06-28

    Development of sensitive and selective analytical methods is required for trace metal and metalloids speciation analysis, including their alkyl-, phenyl- or other organometallic species. Gas chromatography is one of the most suitable techniques for effective separation of the above compounds however it requires that the analytes are volatile or semi-volatile. Today very popular derivatization methods make use of borate reagents for in situ derivatization of elements like Hg, Pb, Sn, Se, As, etc. Tetrahydroborates are suitable for hydride generation and alkylborates for alkylation of the inorganic ions of the above elements, as well as of several partially alkylated ones. This almost immediate reaction can be done in aqueous solutions and produces fully alkylated products of higher volatility suitable for separation by gas chromatography and measured by various detectors. The number of papers published in this field is constantly high, including many applications to various types of matrices, like biological, environmental, industrial, food, polymers, etc. For this reason, many articles of the last two decades are reviewed in this paper and emphasis is given to the use of borate reagents and the relative microreactions for selected elements.

  18. 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.

  19. Ag-Pb Interaction and Enhanced Fluorescence Emission of Pb^2+ in Lead Borate Glasses

    Science.gov (United States)

    Mallur, Saisudha; Giri, Prakash; Dc, Mahendra; Babu, P. K.

    2012-06-01

    We carried out Pb^2+ fluorescence measurements in lead borate glasses and studied the effect of adding Ag into the base glass. Lead borate glasses containing Ag (0 and 3 mol%) were prepared by the usual melt quench method. The prepared glasses were then annealed near the glass transition temperature (400 ^oC) at 5, 10, 20 and 30h. Fluorescence spectra of all these samples were obtained using different excitation wavelengths. In general, Pb^2+ monomers are expected to have emission at wavelength less than 400nm. However, no emission in this region was observed due to the base glass absorption. The emission observed at 450nm is attributed to ^3P1->^1S0 transition of Pb^2+ ions in dimer centers. Addition of Ag enhances the Pb^2+ luminescence intensity at 450 nm which also shows an increase with the annealing time. The possible mechanisms for the fluorescence enhancement in the present glass could be the energy transfer from isolated Ag particles and local field effects due to the difference between the dielectric functions of the glass matrix and the silver particles.

  20. 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.

  1. Effect of Ag Particles on the Fluorescence Properties of Eu Ions in Lead Borate Glasses

    Science.gov (United States)

    Giri, Prakash; Dc, Mahendra; Mallur, Saisudha; Babu, P. K.

    2011-11-01

    We have investigated the effect of Ag particles on the fluorescence of trivalent Eu ions in lead borate glasses. Lead borate glasses were prepared with varying Ag content (0 to 3 mol%) and sizes of Ag particles were controlled by varying the duration of annealing near the glass transition temperature. Fluorescence spectra of all these samples were obtained at two different excitation wavelengths (395 nm and 464 nm). Glass samples with Ag particles show an increase in the intensities for the major peaks in the Eu fluorescence spectra, appearing near 589 nm and 613 nm. Detailed analysis show that the enhancement effects clearly depend on the duration of annealing and the concentration of Ag. Fluorescence intensity enhancement is readily observed at relatively shorter annealing time (5 h) for samples with higher Ag concentration whereas a much longer annealing time (25 h) is required to observe any significant enhancement in fluorescence intensity for lower concentration of Ag. For higher concentrations of Ag, a broad feature is seen around 450 nm due to the emission from Ag particles and the effect of Ag is more pronounced for the fluorescence peak at 589 nm.

  2. 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.

  3. 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.

  4. Facile synthesis of calcium borate nanoparticles and the annealing effect on their structure and size.

    Science.gov (United States)

    Erfani, Maryam; Saion, Elias; Soltani, Nayereh; Hashim, Mansor; Abdullah, Wan Saffiey B Wan; Navasery, Manizheh

    2012-11-08

    Calcium borate nanoparticles have been synthesized by a thermal treatment method via facile co-precipitation. Differences of annealing temperature and annealing time and their effects on crystal structure, particle size, size distribution and thermal stability of nanoparticles were investigated. The formation of calcium borate compound was characterized by X-ray diffraction (XRD) and Fourier Transform Infrared spectroscopy (FTIR), Transmission electron microscopy (TEM), and Thermogravimetry (TGA). The XRD patterns revealed that the co-precipitated samples annealed at 700 °C for 3 h annealing time formed an amorphous structure and the transformation into a crystalline structure only occurred after 5 h annealing time. It was found that the samples annealed at 900 °C are mostly metaborate (CaB(2)O(4)) nanoparticles and tetraborate (CaB(4)O(7)) nanoparticles only observed at 970 °C, which was confirmed by FTIR. The TEM images indicated that with increasing the annealing time and temperature, the average particle size increases. TGA analysis confirmed the thermal stability of the annealed samples at higher temperatures.

  5. Facile Synthesis of Calcium Borate Nanoparticles and the Annealing Effect on Their Structure and Size

    Directory of Open Access Journals (Sweden)

    Manizheh Navasery

    2012-11-01

    Full Text Available Calcium borate nanoparticles have been synthesized by a thermal treatment method via facile co-precipitation. Differences of annealing temperature and annealing time and their effects on crystal structure, particle size, size distribution and thermal stability of nanoparticles were investigated. The formation of calcium borate compound was characterized by X-ray diffraction (XRD and Fourier Transform Infrared spectroscopy (FTIR, Transmission electron microscopy (TEM, and Thermogravimetry (TGA. The XRD patterns revealed that the co-precipitated samples annealed at 700 °C for 3 h annealing time formed an amorphous structure and the transformation into a crystalline structure only occurred after 5 h annealing time. It was found that the samples annealed at 900 °C are mostly metaborate (CaB2O4 nanoparticles and tetraborate (CaB4O7 nanoparticles only observed at 970 °C, which was confirmed by FTIR. The TEM images indicated that with increasing the annealing time and temperature, the average particle size increases. TGA analysis confirmed the thermal stability of the annealed samples at higher temperatures.

  6. 硼酸盐润滑油添加剂的研究现状和进展%Current status and progress of research on borate lubricant additives

    Institute of Scientific and Technical Information of China (English)

    王焕敏; 张治军

    2011-01-01

    综述了国内外硼酸盐润滑油添加剂的研究现状,介绍了针对其合成和作用机制研究的进展,并对其前景进行了展望.指出硼酸盐已成为近年来绿色润滑油添加剂研究领域的热点之一,有机硼酸盐润滑油添加剂克服了无机硼酸盐分散稳定性差的弱点,代表了综合性能优良的硼酸盐润滑油添加剂的发展方向.%A review is provided of the current status of research on borate lubricant additives at home and abroad. The research progress about synthesis and action mechanism of borate lubricant additives are briefed, and prospects are proposed concerning the development of borate lubricant additives in future. It is pointed out that borate has become a hot spot in the research field of green lubricant additives. Particularly, organic borates as lubricating oil additives have no shortcomings like poor dispersion stability of conventional inorganic borates, representing the development directions of novel borate lubricant additives with excellent comprehensive properties.

  7. Near-Zero Thermal Expansion and High Ultraviolet Transparency in a Borate Crystal of Zn4 B6 O13.

    Science.gov (United States)

    Jiang, Xingxing; Molokeev, Maxim S; Gong, Pifu; Yang, Yi; Wang, Wei; Wang, Shuaihua; Wu, Shaofan; Wang, Yingxia; Huang, Rongjin; Li, Laifeng; Wu, Yicheng; Xing, Xianran; Lin, Zheshuai

    2016-09-01

    Intrinsic isotropic near-zero thermal expansion is discovered in borate crystal Zn4 B6 O13 with high transparency in the ultraviolet region. First-principles calculations demonstrate that the very low thermal expansion originates mainly from the invariability of the solid [B24 O48 ] truncated octahedra that are fixed by the [Zn4 O13 ] clusters in the ZBO structure.

  8. Effect of borates on thermal degradation and flame retardancy of epoxy resins using polyhedral oligomeric silsesquioxane as a curing agent

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Hongyu [State Key Laboratory of Fire Science, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026 (China); Department of Building and Construction, City University of Hong Kong and USTC-CityU Joint Advanced Research Centre, Suzhou (China); Suzhou Key Laboratory of Urban Public Safety, Suzhou Institute of University of Science and Technology of China, Suzhou (China); Wang, Xin; Yu, Bin; Song, Lei [State Key Laboratory of Fire Science, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026 (China); Hu, Yuan, E-mail: yuanhu@ustc.edu.cn [State Key Laboratory of Fire Science, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026 (China); Suzhou Key Laboratory of Urban Public Safety, Suzhou Institute of University of Science and Technology of China, Suzhou (China); Yuen, Richard K.K. [Department of Building and Construction, City University of Hong Kong and USTC-CityU Joint Advanced Research Centre, Suzhou (China)

    2012-05-10

    Highlights: Black-Right-Pointing-Pointer Flame retarded epoxy resins with borates were prepared using POSS as a curing agent. Black-Right-Pointing-Pointer Borates and POSS exhibited a synergistic effect on flame retardancy of epoxy resins. Black-Right-Pointing-Pointer Incorporation of borates and POSS significantly reduced the heat release rate. - Abstract: A series of flame-retardant epoxy resins containing boron and silicon were obtained through a crosslinking reaction, using tris (2-hydroxypropyl) borate (THPB) together with octaaminophenyl POSS (OapPOSS) as the curing agents. The limiting oxygen index (LOI) reached 30.5% when the contents of boron and silicon in the cured system were 1.5% and 0.5%, respectively, indicating that THPB and OapPOSS exhibited good flame retardant effect on epoxy resins (EP). Microscale combustion calorimetry (MCC) results indicated that the peak heat release rate (PHRR) and total heat release (THR) of the cured systems were reduced by 69% and 46%, respectively, compared to those of pure EP. Moreover, the thermal degradation process and flame retardant mechanism of the composites were investigated by TGA, real time FTIR and TG-FTIR. The chemical components of the char residues were explored by XPS.

  9. Breaker concentrations required to improve the permeability of proppant packs damaged by concentrated linear and borate-crosslinked fracturing fluids

    Energy Technology Data Exchange (ETDEWEB)

    Brannon, H. (BJ Services (United States)); Pulsinelli, R.J. (Dowell Schlumberger, Tulsa, OK (United States))

    1992-11-01

    This paper reports on the concentrations of an oxidative breaker required to reduce significantly the proppant-pack permeability damage caused by aqueous hydraulic fracturing fluids. Long-term, proppant-pack permeability testing was used to evaluate linear and borate-crosslinked gels. Results indicate that increasing the breaker concentration can reduce proppant-pack permeability damage very effectively.

  10. The tribological behaviour and tribochemical study of B-N type borate esters in rapeseed oil—compound versus salt

    NARCIS (Netherlands)

    Yan, J.; Zeng, X.; Heide, van der E.; Ren, T.; Zhao, Y.D.

    2014-01-01

    Two novel borate ester additives, (2-(2-(bis(2-hydroxyethyl)amino)ethoxy)-1,3,2-dioxaborolan-4-yl)methyl oleate and a tris(2-hydroxyethyl)amine salt of (2-hydroxy-1,3,2-dioxaborolan-4-yl)methyl oleate were prepared and used as anti-wear and extreme pressure agents in rapeseed oil. The tribological p

  11. 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.

  12. 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...

  13. 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.

  14. Electron magnetic resonance and magnetooptical studies of nanoparticle-containing borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Kliava, Janis, E-mail: j.kliava@cpmoh.u-bordeaux1.f [CPMOH, UMR 5798, Universite Bordeaux 1-CNRS, 351 Cours de la Liberation, 33405 Talence Cedex (France); Edelman, Irina; Ivanova, Oxana; Ivantsov, Ruslan; Petrakovskaja, Eleonora [L.V. Kirensky Institute of Physics, Siberian Branch of the RAS, 660036 Krasnoyarsk (Russian Federation); Hennet, Louis [CEMHTI, UPR3079 CNRS et Universite d' Orleans, 1D Avenue de la Recherche Scientifique, 45071 Orleans Cedex 2 (France); Thiaudiere, Dominique [Synchrotron SOLEIL, L' Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette Cedex (France); Saboungi, Marie-Louise [CRMD, UMR 6619, Universite d' Orleans-CNRS, 1b Rue de la Ferollerie, 45071 Orleans Cedex 2 (France)

    2011-03-15

    We report electron magnetic resonance (EMR) and magnetooptical studies of borate glasses of molar composition 22.5K{sub 2}O-22.5Al{sub 2}O{sub 3}-55B{sub 2}O{sub 3} co-doped with low concentrations of Fe{sub 2}O{sub 3} and MnO. In as-prepared samples the paramagnetic ions, as a rule, are in diluted state. However, in the case where the ratio of the iron and manganese oxides in the charge is 3/2, magnetic nanoparticles with characteristics close to those of manganese ferrite are formed already at the first stage of the glass preparation, as evidenced by both magnetic circular dichroism (MCD) and EMR. After thermal treatment all glasses show characteristic MCD and EMR spectra, attesting to the presence of magnetic nanoparticles, predominantly including iron ions. Preliminary EXAFS measurements at the Fe K-absorption edge show an emergence of nanoparticles with a structure close to MnFe{sub 2}O{sub 4} after annealing the glasses at 560 {sup o}C. By computer simulating the EMR spectra at variable temperatures, a superparamagnetic nature of relatively broad size and shape distribution with the average diameter of ca. 3-4 nm. The characteristic temperature-dependent shift of the apparent resonance field is explained by a strong temperature dependence of the magnetic anisotropy in the nanoparticles. The formation of magnetic nanoparticles confers to the potassium-alumina-borate glasses magnetic and magneto-optical properties typical of magnetically ordered substances. At the same time, they remain transparent in a part of the visible and near infrared spectral range and display a high Faraday rotation value. - Research Highlights: >Magnetic nanoparticles are formed in borate glasses co-doped with Fe{sub 2}O{sub 3} and MnO. >The nanoparticle structure is close to that of manganese ferrite. > The particles have large morphological distributions with mean size of 3-4 nm. > These glasses remain transparent in a part of visible and near infrared range. > The glasses show

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

    Energy Technology Data Exchange (ETDEWEB)

    Boshui, Chen, E-mail: boshuichen@163.com; Kecheng, Gu; Jianhua, Fang; Jiang, Wu; Jiu, Wang; Nan, Zhang

    2015-10-30

    Graphical abstract: - Highlights: • Monodispersed stearic acid-capped cerium borate composite nanoparticles were prepared by hydrothermal method. Their morphologies, element compositions, size distributions, crystal and chemical structures, hydrophobic characteristics were also characterized. • The surface-capped cerium borate nanoparticles exhibited excellent dispersing stability in rapeseed oil. As new lubricating additives, they were also outstanding in enhancing friction-reducing and anti-wear capacities of rapeseed oil in biodegradable rapeseed oil. The results presented in this paper would be of important significance for developing green lubricants and lubricant additives. • The prominent tribological performances of SA/CeBO{sub 3} in rapeseed oil were investigated and attributed to the formation of a composite boundary lubrication film mainly composed of lubricous tribochemical species on the tribo-surfaces. - Abstract: Stearic acid-capped cerium borate composite nanoparticles, abbreviated as SA/CeBO{sub 3}, were prepared by hydrothermal method. The morphologies, element compositions, size distributions, crystal and chemical structures, hydrophobic characteristics, of SA/CeBO{sub 3} 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/CeBO{sub 3} 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/CeBO{sub 3} were monodispersed nanospheres with an average diameter of 8 nm, and exhibited excellent dispersing stability in rapeseed oil. Meanwhile, SA/CeBO{sub 3} nanospheres were outstanding in enhancing friction-reducing and anti-wear capacities of rapeseed oil. The prominent

  16. Emission properties of Ce3+ centers in barium borate glasses prepared from different precursor materials

    Science.gov (United States)

    Torimoto, Aya; Masai, Hirokazu; Okada, Go; Kawaguchi, Noriaki; Yanagida, Takayuki; Ohkubo, Takahiro

    2017-10-01

    The photoluminescence (PL) and X-ray induced luminescence properties of Ce-doped barium borate glasses prepared from different precursor materials have been investigated. Oxidation of Ce3+ takes place during the melting process performed using a pre-vitrified non-doped glass. Residual groups originated from the precursor materials, such as fluorine atoms and OH groups, are found to affect the optical and emission properties of the glasses. Moreover, both the PL and the X-ray induced luminescence properties of the glasses depend on the precursor materials used for their synthesis. Based on a thorough analysis of the emission properties, we conclude that the best synthesis conditions involve melting a batch containing Ce(CH3COO)3·H2O, BaCO3, and B2O3 in Ar atmosphere.

  17. Lithium ion conductivity of gel polymer electrolytes containing insoluble lithium tetrakis(pentafluorobenzenethiolato) borate

    Energy Technology Data Exchange (ETDEWEB)

    Aoki, Takahiro; Ohta, Takayuki; Fujinami, Tatsuo [Department of Materials Science and Chemical Engineering, Faculty of Engineering, Shizuoka University, 3-5-1, Johoku, Hamamatsu 432-8561 (Japan)

    2006-06-01

    Lithium ion conducting gel polymer electrolytes composed of insoluble lithium tetrakis(pentafluorobenzenethiolato) borate (LiTPSB), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and ethylene carbonate-propylene carbonate mixed solvent (EC-PC) were prepared and their ionic conductivities and electrochemical stabilities were investigated. Ionic conductivity was largely dependent on the contents of EC-PC and LiTPSB. Gel polymer electrolyte containing optimized content of 50 (LiTPSB)-50 (PVDF-HFP/EC-PC (13:87wt.%)) exhibited ionic conductivity of 4x10{sup -4}Scm{sup -1} at 30{sup o}C, lithium ion transference number of 0.33 and anodic oxidation potential of 4.2V. (author)

  18. Lithium ion conductivity of gel polymer electrolytes containing insoluble lithium tetrakis(pentafluorobenzenethiolato) borate

    Science.gov (United States)

    Aoki, Takahiro; Ohta, Takayuki; Fujinami, Tatsuo

    Lithium ion conducting gel polymer electrolytes composed of insoluble lithium tetrakis(pentafluorobenzenethiolato) borate (LiTPSB), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and ethylene carbonate-propylene carbonate mixed solvent (EC-PC) were prepared and their ionic conductivities and electrochemical stabilities were investigated. Ionic conductivity was largely dependent on the contents of EC-PC and LiTPSB. Gel polymer electrolyte containing optimized content of 50 (LiTPSB)-50 (PVDF-HFP/EC-PC (13:87 wt.%)) exhibited ionic conductivity of 4 × 10 -4 S cm -1 at 30 °C, lithium ion transference number of 0.33 and anodic oxidation potential of 4.2 V.

  19. Polymer electrolytes composed of lithium tetrakis(pentafluorobenzenethiolato) borate and poly(fluoroalkylcarbon)s

    Energy Technology Data Exchange (ETDEWEB)

    Aoki, Takahiro; Konno, Akinori; Fujinami, Tatsuo [Department of Materials Science and Chemical Engineering, Faculty of Engineering, Shizuoka University, 3-5-1, Johoku, Hamamatsu 432-8561 (Japan)

    2005-08-26

    Lithium ion conducting polymer electrolytes were prepared by mixing insoluble lithium tetrakis(pentafluorobenzenethiolato) borate (LiTPSB) with poly(vinylidene fluoride) (PVDF) or poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP). Their films were prepared by hot pressing and are investigated for ionic conductivity and thermal properties. LiTPSB is insoluble in PVDF. Ionic conductivity was largely dependent on the salt content for LiTPSB-PVDF composite polymer electrolytes, and exhibited higher ionic conductivity than homogeneous LiTFSI-PVDF based polymer electrolytes. Melting point and crystallinity of PVDF were independent on LiTPSB content, resulting in no difference for melting point and crystallinity between pure PVDF and LiTPSB-PVDF. Ionic conductivity was effectively improved by incorporation of 18-crown-6 or kryptofix222 for LiTPSB-PVDF based polymer electrolytes. (author)

  20. Growth and characterization of semiorganic nonlinear optical rubidium bis-DL-malato borate single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Balasubramanian, D. [Post Graduate and Research Department of Physics, Pachaiyappa' s College, Chennai 600030 (India); Sankar, R. [Crystal Growth Centre, Anna University, Chennai 600025 (India); Shankar, V. Siva [Post Graduate and Research Department of Physics, Pachaiyappa' s College, Chennai 600030 (India); Murugakoothan, P. [Post Graduate and Research Department of Physics, Pachaiyappa' s College, Chennai 600030 (India)], E-mail: pmurugakoothan@yahoo.com; Arulmozhichelvan, P. [Post Graduate and Research Department of Physics, Pachaiyappa' s College, Chennai 600030 (India); Jayavel, R. [Crystal Growth Centre, Anna University, Chennai 600025 (India)

    2008-01-15

    A new semiorganic nonlinear optical rubidium bis-DL-malato borate (RBMB) has been synthesized and single crystals were grown by slow cooling technique from aqueous solution. The grown crystals have been characterized by X-ray diffraction (single crystal XRD) to confirm the formation of the crystalline phases. FT-IR and FT-Raman spectroscopic analyses confirm the presence of all the functional groups in the grown crystals. TG-DTA studies reveal that the material is stable up to 230 deg. C. The UV-vis transmission spectrum shows a lower cutoff wavelength of 230 nm. The emission of SHG using Nd:YAG laser is confirmed by a modified Kurtz and Perry powder setup.

  1. 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.

  2. Efficiency of a blast furnace slag cement for immobilizing simulated borate radioactive liquid waste.

    Science.gov (United States)

    Guerrero, A; Goñi, S

    2002-01-01

    The efficiency of a blast furnace slag cement (Spanish CEM III/B) for immobilizing simulated radioactive borate liquid waste [containing H3BO3, NaCl, Na2SO4 and Na(OH)] has been evaluated by means of a leaching attack in de-mineralized water at the temperature of 40 degrees C over 180 days. The leaching was carried out according to the ANSI/ANS-16.1-1986 test. Moreover, changes of the matrix microstructure were characterized through porosity and pore-size distribution analysis carried out by mercury intrusion porosimetry (MIP), X-ray diffraction (XRD) and thermal analysis (TG). The results were compared with those obtained from a calcium aluminate cement matrix, previously published.

  3. 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.

  4. 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.

  5. 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.

  6. 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...... 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. 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.

  8. 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.

  9. 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.

  10. Novel Preparation of Calcium Borate/Graphene Oxide Nanocomposites and Their Tribological Properties in Oil

    Science.gov (United States)

    Li, Wei; Cheng, Zhi-Lin; Liu, Zan

    2017-01-01

    The calcium borate/graphene oxide (CB/GO) nanocomposites have been successfully prepared by a liquid phase-based ultrasonic-assisted stripping method, which were subsequently explored as lubricant additive. The structure and morphology of the as-prepared nanocomposites were characterized by FT-IR, XRD, Raman, TEM, EDS and TGA, revealing that CB nanoparticles were uniformly loaded on GO surfaces. The nanocomposites were highly dispersed into the base oil by sand milling. The tribological properties of CB/GO nanocomposites as lubricating oil additive were investigated using a four-ball machine, and the wear scar surfaces were observed by the 3D Laser Scanning Microscope. The results indicated that CB/GO nanocomposites were of excellent antifriction, antiwear ability and load-carrying capacity.

  11. 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.

  12. 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.

  13. Synthesis and characterization of holmium oxide doped cadmium lead borate glasses

    Science.gov (United States)

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

    Holmium doped cadmium lead borate glasses were prepared from melting in appropriate proportions of a mixture of CdO, PbO2, H3BO3 and (1-2 mol %) Ho2O3 in the temperature range of 800-850 °C. The density of glass samples was measured using Archimedes Principle. The infrared spectra of the glasses in the range of 400-4000 cm-1 showed their structure systematically. No boroxol ring formation was observed in the structure of these glasses, but the conversion of 3-fold to 4-fold coordination of boron atoms in the structure of glasses was observed. The glass transition studies were done through differential scanning calorimetry. The optical analysis is done by using the Judd-Ofelt theory.

  14. Structural and time resolved emission spectra of Er 3+: Silver lead borate glass

    Science.gov (United States)

    Coelho, João; Hungerford, Graham; Hussain, N. Sooraj

    2011-08-01

    The structural properties of Er 3+: silver lead borate glass is assessed by means of SEM, X-ray mapping, EDS and Raman analysis. In order to verify the time dependency of emission spectra, steady-state luminescence spectroscopy (SSLS) and time-resolved emission spectroscopy (TRES) studies have been performed. The stimulated emission cross-sections for the NIR emission transition 4I 13/2 → 4I 15/2 (1535 nm) at 970 nm excitation are reported. The decay times were obtained by fitting one ( τm = 0.301 ms) and two ( τm1 = 0.141 ms, τm2 = 0.368 ms) distributions for the NIR transition. Furthermore, by making use of TRES measurements the decay associated spectra were obtained allowing the time dependency for the different emission bands to be elucidated.

  15. Novel Preparation of Calcium Borate/Graphene Oxide Nanocomposites and Their Tribological Properties in Oil

    Science.gov (United States)

    Li, Wei; Cheng, Zhi-Lin; Liu, Zan

    2016-11-01

    The calcium borate/graphene oxide (CB/GO) nanocomposites have been successfully prepared by a liquid phase-based ultrasonic-assisted stripping method, which were subsequently explored as lubricant additive. The structure and morphology of the as-prepared nanocomposites were characterized by FT-IR, XRD, Raman, TEM, EDS and TGA, revealing that CB nanoparticles were uniformly loaded on GO surfaces. The nanocomposites were highly dispersed into the base oil by sand milling. The tribological properties of CB/GO nanocomposites as lubricating oil additive were investigated using a four-ball machine, and the wear scar surfaces were observed by the 3D Laser Scanning Microscope. The results indicated that CB/GO nanocomposites were of excellent antifriction, antiwear ability and load-carrying capacity.

  16. Transient receptor potential A1 is involved in cold-induced contraction in the isolated rat colon smooth muscle.

    Science.gov (United States)

    Dong, Yang; Shi, Hai-Lian; Shi, Jian-Rong; Wu, Da-Zheng

    2010-08-25

    Transient receptor potential (TRP) A1, a member of TRP channel family, is activated by noxious cold. The aims of this study were to determine if TRPA1 contributed to cold-induced contractions in the isolated rat colon preparations and explore the potential mechanisms. The colon smooth muscle layers were surgically isolated from the male Wistar rats and changes in isotonic tension of longitudinal muscle under various treatments were recorded as colonic motilities. Cold stimuli were obtained by the reperfusion with Krebs-Henseleit solution at given temperature using Constant Flow Pump. The mRNA expressions of TRPA1, TRPV1 and TRPM8 in rat colon smooth muscle layer were examined by using reverse transcription-polymerase chain reaction (RT-PCR) techniques. The results showed that the contractions induced by cold stimuli (from 37 degrees C to 12 degrees C stepwise) were inversely proportional to the temperature with a maximum contraction at 17 degrees C in both proximal and distal colons (Pcolon smooth muscle layers. Cold-induced colonic contractions were specially inhibited by TRPA1 blocker, ruthenium red (30 μmol/L), in the proximal and distal colon (Pcolons (both PCA, 1 mmol/L). Extracellular calcium removal (EGTA, 1 mmol/L), PLC blocker (U73122, 10 μmol/L) and IP(3) receptor blocker (2-aminoethoxydiphenyl borate, 2-APB, 30 μmol/L) all decreased the contractions evoked by the cooling at 17 degrees C in the proximal and distal colon (PCa(2+) channels blocker nifedipine (1 μmol/L) and neurotoxin tetrodotoxin (TTX, 2 μmol/L) decreased the contractile response in the distal colon (Pcolon. In conclusion, TRPA1 contributes to cold-induced contractions of the rat colon smooth muscle, and the mechanism of TRPA1 activation involves PLC/IP(3)/Ca(2+) pathway. L-type Ca(2+) channel and neurogenic mechanism other than muscarinic receptor might be partially involved in cold-induced contraction of the distal colon, which probably resulted in higher contraction of distal colon

  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. 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.

  19. 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.

  20. 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.

  1. 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.

  2. Silver lead borate glasses doped with europium ions for phosphors applications

    Indian Academy of Sciences (India)

    K KESHAVAMURTHY; B ERAIAH

    2017-08-01

    Europium (Eu$^{3+}$) doped silver lead borate glasses with the composition of $x$Eu$_2$O$_3$−($1 − x$)Ag$_2$O−29PbO−70B$_2$O$_3$ ($x = 0$, 0.1, 0.2, 0.3, 0.4 and 0.5 mol%) have been successfully prepared by conventional meltquenching method. Thermal, structural and luminescence properties have been studied using thermograms, transmittance,excitation and emission spectra. From the differential scanning calorimetry studies, the glass transition temperatures ($T_g$)have been investigated and their values are ranging from 449 to 458$^{\\circ}$C. The investigation of Fourier transformer infraredspectra shows the presence of boron atoms in both BO$_3$ and BO$_4$ units in the glass network. In addition, it was foundthat new structural groups were present, such as boroxyl rings, pyro and dipenta-borate. Photoluminescence spectroscopywas used to examine down conversion emission under 394 nm excitation, which exhibits five emission bands centred at577, 590, 612, 650 and 697 nm corresponding to ${}^5$D$_0$−${}^7$F$_0$, ${}^5$D$_0$−${}^7$F$_1$, ${}^5$D$_0$−${}^7$F$_2$, ${}^5$D$_0$−${}^7$F$_3$ and ${}^5$D$_0$−${}^7$F$_40$ transitions ofEu$^{3+}$ ions, respectively. The Commission International de I’Eclairage France 1931 chromaticity coordinates estimatedfrom the emission spectra; it was shown that a 0.5 mol% Eu$_2$O$_3$ doped glass is quite suitable for efficient red phosphors application.

  3. Luminescence spectroscopy of rare earth-doped oxychloride lead borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Pisarski, Wojciech A., E-mail: Wojciech.Pisarski@us.edu.p [University of Silesia, Institute of Chemistry, Szkolna 9, 40-007 Katowice (Poland); Pisarska, Joanna [University of Silesia, Institute of Chemistry, Szkolna 9, 40-007 Katowice (Poland); Lisiecki, RadosLaw [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Okolna 2, 50-422 WrocLaw (Poland); Grobelny, Lukasz [University of Silesia, Institute of Chemistry, Szkolna 9, 40-007 Katowice (Poland); Dominiak-Dzik, Grazyna; Ryba-Romanowski, Witold [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Okolna 2, 50-422 WrocLaw (Poland)

    2011-04-15

    Ln-doped oxychloride lead borate glasses were studied using luminescence spectroscopy. Rare earth ions were limited to trivalent Pr{sup 3+}, Tm{sup 3+}, Eu{sup 3+} and Er{sup 3+}. Luminescence spectra were registered, which correspond to {sup 3}P{sub 0}-{sup 3}H{sub 4} and {sup 1}D{sub 2}-{sup 3}H{sub 4} transitions of Pr{sup 3+}, {sup 1}G{sub 4}-{sup 3}H{sub 5} and {sup 1}G{sub 4}-{sup 3}F{sub 4} transitions of Tm{sup 3+}, {sup 5}D{sub 0}-{sup 7}F{sub J} (J=0, 1, 2, 3, 4) transitions of Eu{sup 3+} and {sup 4}S{sub 3/2},{sup 2}H{sub 11/2}-{sup 4}I{sub 15/2} and {sup 4}I{sub 13/2}-{sup 4}I{sub 15/2} transitions of Er{sup 3+}. Luminescence decays from the excited states of Ln{sup 3+} ions were analyzed in detail. The experimental results indicate that relatively high phonon energy of the host gives important contribution to the excited state relaxation of rare earth ions. - Research Highlights: {yields}Lead borate glasses modified by PbCl{sub 2} were synthesized. {yields}Luminescence of Pr{sup 3+}, Tm{sup 3+}, Eu{sup 3+} and Er{sup 3+} ions in multicomponent oxychloride glasses was registered. {yields}From decay curves luminescence lifetimes for the excited states of rare earth ions were determined. {yields}The relatively high phonon energy of the host gives important contribution to the excited state relaxation of rare earth ions.

  4. 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.

  5. 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

  6. To immobilize polyethylene glycol-borate ester/lithium fluoride in graphene oxide/poly(vinyl alcohol) for synthesizing new polymer electrolyte membrane of lithium-ion batteries

    OpenAIRE

    Huang, Y.F.; Zhang, M. Q.; M. Z. Rong; W. H. Ruan

    2017-01-01

    Polymer electrolyte membranes (PEMs) are potentially applicable in lithium-ion batteries with high safety, low cost and good performance. Here, to take advantages of ionic conductivity and selectivity of borate ester-functionalized small molecules as well as structural properties of polymer nanocomposite, a strategy of immobilizing as-synthesized polyethylene glycol-borate ester/lithium fluoride (B-PEG/LiF) in graphene oxide/poly(vinyl alcohol) (GO/PVA) to prepare a PEM is put forward. Chemic...

  7. Ca3Na4LiBe4B10O24F: a new beryllium borate with a unique beryl borate ∞(2)[Be8B16O40F2] layer intrabridged by [B12O24] groups.

    Science.gov (United States)

    Luo, Siyang; Yao, Wenjiao; Gong, Pifu; Yao, Jiyong; Lin, Zheshuai; Chen, Chuangtian

    2014-08-18

    A novel beryllium borate, Ca3Na4LiBe4B10O24F, has been discovered. It possesses a unique ∞(2)[Be8B16O40F2] layer composed of two opposite parallel [Be4B4O12F]∞ layers bridged with [B12O24] polyborates. The linkage of [B12O24] to other structural units is first found in anhydrous borates. In the ∞(2)[Be8B16O40F2] layer, multiple tunnels are arranged along different directions resided by the alkali and alkaline-earth cations. The compound remains stable in an ambient atmosphere from room temperature to the melting point at 830 °C and melts incongruently.

  8. Influence des ions lithium et borate sur l'hydratation de ciments sulfo-alumineux : application au conditionnement de résines échangeuses d'ions boratées

    OpenAIRE

    2015-01-01

    In pressurized water reactors, a solution of boric acid, the pH of which is controlled by the addition of lithium hydroxide, is injected in the primary circuit. Boron acts as a neutron moderator and helps controlling the fission reactions. The primary coolant is purified by flowing through columns of ion exchange resins. These resins are periodically renewed and constitute a low-level radioactive waste. In addition to radionuclides, they mainly contain borate and lithium ions. They are curren...

  9. 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

    2013-01-01

    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

  10. Infrared-to-visible conversion luminescence of Er 3+ ions in lead borate transparent glass-ceramics

    Science.gov (United States)

    Pisarski, Wojciech A.; Pisarska, Joanna; Lisiecki, Radosław; Grobelny, Łukasz; Dominiak-Dzik, Grażyna; Ryba-Romanowski, Witold

    2009-10-01

    Transparent glass-ceramics were successfully prepared during controlled heat treatment of lead borate glasses. The PbF 2 particles were dispersed into a borate glass matrix which was evidenced by X-ray diffraction analysis. The phase identification revealed that crystalline peaks can be related to the orthorhombic PbF 2 phase. Green up-conversion luminescence due to the 4S 3/2- 4I 15/2 transition of Er 3+ ions was registered. In comparison to the precursor glass the luminescence intensity was considerably higher, whereas the luminescence linewidth slightly decreased in the studied oxyfluoride transparent glass-ceramics. It indicated that a part of the trivalent erbium was incorporated into the PbF 2 crystalline phase.

  11. Molecular Dynamics Simulation of Lead Borate and Related Glasses in Multicomponent Systems for Low Melting Vitrification of Nuclear Wastes

    Science.gov (United States)

    Kato, S.; Sakida, S.; Benino, Y.; Nanba, T.

    2011-03-01

    Glasses based on lead oxide have excellent properties in general such as low melting point, high chemical durability and high stability of glassy form, which are suitable for the preservation of volatile nuclear wastes in a permanent vitrified form. In order to confirm the long-term performance of lead borate based glasses it is necessary to establish dissolution and diffusion processes based on a reliable model of the glass structure. In the present study molecular dynamics (MD) simulation of lead borate based glasses was carried out introducing a dummy negative point charge to reproduce asymmetric PbOn units. Parameters for the dummy charge were optimized based on the comparison between calculated radial distribution function and experimental one. Asymmetric coordination around Pb, for example trigonal bipyramid, was successfully reproduced in the MD simulated binary and ternary glass models. The simple model using the dummy charge was confirmed to be valid for further simulations of multicomponent glasses containing nuclear wastes and heavy elements.

  12. 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.

  13. 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.

  14. The Kramer deposit of southern California--Preliminary insights on the origins of zoned lacustrine evaporite borate deposits

    Energy Technology Data Exchange (ETDEWEB)

    Swihart, G.H. (Memphis State Univ., TN (United States). Dept. of Geological Sciences); McBay, E.H.; Smith, D.H. (Oak Ridge National Lab., TN (United States)); Siefke, J.W. (Borax and Chemical Corp., Boron, CA (United States))

    1992-01-01

    Lacustrine evaporite borate deposits span the range from mineralogically unzoned or poorly zoned to concentrically or complexly zoned types. Deposits often contain an inner ulexite or probertite (Na-Ca borates) zone and an outer colemanite (Ca borate) zone. A few deposits contain an innermost borax (Na borate) zone. Boron isotopic analyses of core material from the zoned borax-ulexite-colemanite Kramer deposit have been made with the aim of providing a better understanding of the processes of zone formation. Samples from 6 depths over a 63 foot interval in the borax zone yield a [delta] B-11 range of +0.1 to +2.3 permil. Two samples in the portion of the ulexite zone below the borax zone, vertically separated from one another by 20 feet, yield identical results of [delta]B-11 = [minus]2.1 permit. Three ulexite samples from a 10 foot interval above the borax zone produced results in the range [delta]B-11 = [minus]4.6 to [minus]5.5 permil. A number of possible origins for ulexite at Kramer have been proposed: (1) primary precipitation from the lake brines; (2) postdepositional alteration of the borax zone margin by Ca-rich groundwater; (3) mixing of seeping lake brines and Ca-rich groundwater in muds around the lake. Given the small variation in B isotopic composition exhibited in the borax zone, mechanisms 1 and 2 would produce upper and lower portions of the ulexite zone with similar isotopic compositions. In the third scenario, the difference in composition of the upper and lower ulexites could be due to distance from the lake and relative proportions of seeped lake brine (B-11-rich) and clay adsorbed B (B-10-rich). Furthermore, the cotton ball form of the ulexite in this core is identical to that of ulexite forming today just beneath the surface of dry lakes in NV and CA.

  15. Shielding behavior of V{sub 2}O{sub 5} doped lead borate glasses towards gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Ghoneim, N.A.; ElBatal, H.A. [Glass Research Department, National Research Center, Dokki, Cairo (Egypt); Abdelghany, A.M., E-mail: a.m_abdelghany@yahoo.com [Spectroscopy Department, National Research Center, Dokki, Cairo (Egypt); Ali, I.S. [High Institute for Optics Technology, Dokki, Cairo (Egypt)

    2011-06-16

    Highlights: > Base lead borate glass together with samples of the same composition doped with varying V{sub 2}O{sub 5} contents were prepared. > UV-visible and infrared spectroscopy were measured before and after successive gamma irradiation. > Glass samples are observed to absorb strongly in the UV. > Infrared absorption spectra indicate the presence of both triangular and tetrahedral borate groups besides the sharing of lead ions in network forming and network modifying sites. - Abstract: Undoped lead borate glass of the composition PbO 70%-B{sub 2}O{sub 3} 30% together with samples of the same composition and doped with varying V{sub 2}O{sub 5} contents were prepared. UV-visible absorption spectra were measured out in the range 200-1500 nm before and after successive gamma irradiation. Infrared absorption measurements within the range 4000-400 cm{sup -1} were carried out for the undoped and V{sub 2}O{sub 5} doped samples before gamma irradiation and after being irradiated with a dose of 6 Mrad. All the glass samples are observed to absorb strongly in the UV region due to the combined contributions of absorption due to trace iron impurities and that from the divalent lead Pb{sup 2+} ions. The V{sub 2}O{sub 5}-doped glasses reveal extra visible absorption bands which are attributed to the existence of V{sup 3+} ions in measurable content but not neglecting the other valence states of vanadium ions (V{sup 4+}, V{sup 5+}). Infrared absorption spectra indicate the presence of both triangular and tetrahedral borate groups besides the sharing of lead ions in network forming and network modifying sites.

  16. Effects of varying base glass composition on the optical properties of lead borate glasses doped with rare earth ions

    Science.gov (United States)

    Heidorn, William D.

    Rare Earth (RE) doped lead borate glasses are expected to exhibit a compositional dependence in their optical properties due to the changes induced by variations in the structure of the base glass with increasing lead oxide content. A series of lead borate glasses with the composition xPbO:(99.5 - x)B2O 3 (x = 29.5 to 69.5 in steps of 10 mol%) doped with 0.5 mol% Sm2O3, Er2O3, and Ho2O3 were prepared using the melt quench technique followed by 3 hours of annealing near the glass transition temperature. Optical absorption and fluorescence spectra of these RE doped lead borate glasses were analyzed using Judd-Ofelt theory. The compositional dependence of Judd-Ofelt intensity parameters, O t (t = 2, 4, 6), were determined and were then used to calculate the radiative transition probability of the excited states, the total radiative transition probability, branching ratios, and radiative lifetime of the glasses. From the fluorescence spectra the stimulated emission cross section, and Stark splitting of the excited states were calculated as a function of glass composition. A fourth set of samples with composition xPbO:(99 - x)B2O 3(x = 29 to 69 in steps of 10 mol%) co-doped with 0.5 mol% Er2 O3 and Ho2O3 were also prepared and the effects of co-doping on the absorption and fluorescence were analyzed. In all the glass systems studied, it was found that the optical properties are strongly influenced by structural changes arising from compositional variation. Er3+ transitions exhibit large stimulated cross section suggesting the possible utilization of these materials in laser applications. Keywords: Lead and bismuth borate glasses, fluorescence, optical absorption, Sm3+, Ho3+, Er3+ ions, Judd-Ofelt intensity parameters, stimulated emission cross section.

  17. 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.

  18. Luminescence investigations of rare earth doped lead-free borate glasses modified by MO (M = Ca, Sr, Ba)

    Energy Technology Data Exchange (ETDEWEB)

    Janek, Joanna, E-mail: janek.joanna@gmail.com; Sołtys, Marta; Żur, Lidia; Pietrasik, Ewa; Pisarska, Joanna; Pisarski, Wojciech A.

    2016-09-01

    Series of lead-free borate glasses with different oxide modifiers and lanthanide ions were prepared. The effect of oxide modifiers MO (M = Ca, Sr, Ba) on spectroscopic properties of trivalent Ln{sup 3+} (Ln = Eu, Er, Pr) were systematically investigated. Especially, the luminescence spectra of Ln{sup 3+}-doped lead-free borate glasses are presented and discussed in relation to the impact of selective components (CaO, SrO and BaO). Several spectroscopic parameters, such as the fluorescence intensity ratio R/O (Eu{sup 3+}) and measured luminescence lifetimes for the {sup 5}D{sub 0} (Eu{sup 3+}), {sup 4}I{sub 13/2} (Er{sup 3+}) and {sup 1}D{sub 2} (Pr{sup 3+}) excited states of lanthanide ions were analyzed in details. The research proved that spectroscopic properties of trivalent Ln{sup 3+} depend significantly on kind of presence oxide modifiers MO (M = Ca, Sr, Ba) in glass host matrices. - Highlights: • Luminescence of Ln{sup 3+}-doped borate glasses was presented and discussed. • Effect of glass modifiers on spectroscopic properties of rare earths was studied. • Measured luminescence lifetimes of Ln{sup 3+} (Ln = Eu, Er, Pr) were analyzed. • Luminescence intensity ratios R/O (Eu{sup 3+}) were determined.

  19. Mo{sub 2}B{sub 4}O{sub 9} - connecting borate and metal-cluster chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, Martin K.; Huppertz, Hubert [Institut fuer Allgemeine, Anorganische und Theoretische Chemie, Universitaet Innsbruck (Austria); Janka, Oliver; Poettgen, Rainer [Institut fuer Anorganische und Analytische Chemie, Universitaet Muenster (Germany); Benndorf, Christopher [Institut fuer Anorganische und Analytische Chemie, Universitaet Muenster (Germany); Institut fuer Physikalische Chemie, Universitaet Muenster (Germany); Institut fuer Mineralogie, Kristallographie und Materialwissenschaften, Universitaet Leipzig (Germany); Oliveira, Marcos de Jr. [Sao Carlos Institute of Physics, University of Sao Paulo, Sao Carlos (Brazil); Eckert, Hellmut [Institut fuer Physikalische Chemie, Universitaet Muenster (Germany); Sao Carlos Institute of Physics, University of Sao Paulo, Sao Carlos (Brazil); Pielnhofer, Florian; Tragl, Amadeus-Samuel [Institut fuer Anorganische Chemie, Universitaet Regensburg (Germany); Weihrich, Richard [Institut fuer Materials Resource Management, Universitaet Augsburg (Germany); Joachim, Bastian [Institut fuer Mineralogie und Petrographie, Universitaet Innsbruck (Austria); Johrendt, Dirk [Department Chemie, Ludwig-Maximilians-Universitaet Muenchen (Germany)

    2017-06-01

    We report on the first thoroughly characterized molybdenum borate, which was synthesized in a high-pressure/high-temperature experiment at 12.3 GPa/1300 C using a Walker-type multianvil apparatus. Mo{sub 2}B{sub 4}O{sub 9} incorporates tetrahedral molybdenum clusters into an anionic borate crystal structure - a structural motif that has never been observed before in the wide field of borate crystal chemistry. The six bonding molecular orbitals of the [Mo{sub 4}] tetrahedron are completely filled with 12 electrons, which are fully delocalized over the four molybdenum atoms. This finding is in agreement with the results of the magnetic measurements, which confirmed the diamagnetic character of Mo{sub 2}B{sub 4}O{sub 9}. The two four-coordinated boron sites can be differentiated in the {sup 11}B MAS-NMR spectrum because of the strongly different degrees of local distortions. Experimentally obtained IR and Raman bands were assigned to vibrational modes based on DFT calculations. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. 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

  1. Structural influence of mixed transition metal ions on lithium bismuth borate glasses

    Science.gov (United States)

    Yadav, Arti; Dahiya, Manjeet S.; Hooda, A.; Chand, Prem; Khasa, S.

    2017-08-01

    Lithium bismuth borate glasses containing mixed transition metals having composition 7CoO·23Li2O·20Bi2O3·50B2O3 (CLBB), 7V2O5·23Li2O·20Bi2O3·50B2O3 (VLBB) and x(2CoO·V2O5)·(30 - x)Li2O·20Bi2O3·50B2O3 (x = 0.0 (LBB) and x = 2.0, 5.0, 7.0, 10.0 mol% (CVLBB1-4)) are synthesized via melt quench route. The synthesized compositions are investigated for their physical properties using density (D) and molar volume (Vm), thermal properties by analyzing DSC/TG thermo-graphs, structural properties using IR absorption spectra in the mid-IR range and optical properties using UV-Vis-NIR spectroscopy. The Electron Paramagnetic Resonance (EPR) spectra of vanadyl and cobalt ion have been analyzed to study compositional effects on spin-Hamiltonian parameters. The non linear variations in physical properties depict a strong structural influence of Co/V- oxides on the glassy matrix. The compositional variations in characteristic temperatures (glass transition temperature Tg, glass crystallization temperature Tp and glass melting temperature Tm) reveals that Tg for glass samples CLBB is relatively less than that of pure lithium bismuth borate (LBB) glass sample wherein Tg for sample VLBB is higher than that of LBB. The increase in Tg (as compared with LBB) with an enhanced substitution of mixed transition metal oxides (2CoO·V2O5) shows a progressive structure modification of bismuth borate matrix. These predictions are very well corroborated by corresponding compositional trends of Tp and Tm. FTIR studies reveal that Co2+& VO2+ ions lead to structural rearrangements through the conversion of three-coordinated boron into four coordinated boron and thereby reducing number of non-bridging oxygen atoms. Bismuth is found to exist in [BiO6] octahedral units only, whereas boroxol rings are not present in the glass network. The theoretical values of optical basicity (Λth) and corresponding oxide ion polarizability (αo2-) have also been calculated to investigate oxygen covalency of

  2. 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)

  3. Effect of La2O3 on the structure and the properties of strontium borate glasses

    Directory of Open Access Journals (Sweden)

    Smiljanić Sonja V.

    2016-01-01

    Full Text Available The selected lanthanum-strontium-borate glasses were prepared by a conventional melt-quenching technique. The compositions of the investigated glasses were chosen to be: 5.7, 9.5, 14.3, 19.1 mol % for La2O3, 22.9, 19.1, 14.3, 9.5 for mol % SrO and 71.4 mol % for B2O3. The density, molar volume, oxygen molar volume, oxygen packing density, oxygen/boron ratios and structural transformations in the glass network were investigated according to the substitution of SrO by La2O3. The density and the molar volume increased in parallel with La2O3 content increase. Simultaneously, oxygen molar volume values increased while the oxygen packing density values decreased. A hot stage microscope (HSM and a differential thermal analysis (DTA were used to determine the characteristic temperatures. By increasing the content of lanthanum, the glass transition temperatures, changed with the same trend as the molar volume. Glass stability parameters were calculated from the temperatures obtained by DTA and HSM. The HSM results were used to obtain the viscosity curves by applying Vogel-Fulcher-Tamman (VFT equation. [Projekat Ministarstva nauke Republike Srbije, br. 172004 i br. 34001

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Luminescence features of dysprosium and phosphorus oxide co-doped lithium magnesium borate glass

    Science.gov (United States)

    Hashim, S.; Mhareb, M. H. A.; Ghoshal, S. K.; Alajerami, Y. S. M.; Saripan, M. I.; Bradley, D. A.

    2017-08-01

    Lithium magnesium borate (LMB) glass system co-doped with the oxides of dysprosium (Dy2O3) and phosphorus (P2O5) were synthesized using melt-quenching method. Prepared samples were characterized using various techniques to determine the effects of co-dopants concentration variation on their thermoluminescence (TL) and photoluminescence (PL) properties. TL glow curves of LMB:0.5Dy sample revealed a single prominent peak at Tm=190 °C, where TL intensity was enhanced by a factor of 2.5 with the increase of P2O5 concentration up to 1 mol%. This enhancement was accompanied by a shift in Tm towards higher temperature. Good linearity in the range of 1-100 Gy with linear correlation coefficient of 0.998 was achieved. PL spectra displayed two significant peaks centred at 481 nm and 573 nm. These attractive luminescence features of the proposed glass system may be useful for the development of radiation dosimetry.

  9. 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.

  10. Spectroscopic Study on Eu3+ Doped Borate Glasses Containing Ag Nanoparticles and Ag Aggregates.

    Science.gov (United States)

    Fu, Shaobo; Zheng, Hui; Zhang, Jinsu; Li, Xiangping; Sun, Jiashi; Hua, Ruinian; Dong, Bin; Xia, Haiping; Chen, Baojiu

    2015-01-01

    Transparent Eu(3+)-doped borate glasses containing Ag nanoparticles and Ag aggregates with composition (40 - x) CaO-59.5B2O3-0.5Eu2O3-xAgNO3 were prepared by a simple one-step melt-quenching technique. The X-ray diffraction (XRD) patterns of the glasses reveal amorphous structural properties and no diffraction peaks belonging to metal Ag particles. Ag particles and Ag aggregates were observed from the absorption spectra. Effective energy transfers from the Ag aggregates to the Eu3+ ions were observed in the excitation spectra from monitoring the intrinsic emission of Eu3+x .5D0 --> 7F2. The glasses with higher Ag content can be effectively excited by light in a wide wavelength region, indicating that these glasses have potential application in the solid state lighting driven by semiconductor light emitting diodes (LEDs). The emission spectra of the samples with higher Ag contents exhibit plenteous spectral components covering the full visible region from violet to red, thus indicating that these glass materials possess an excellent and tunable color rendering index. The color coordinates for all the glass samples were calculated by using the intensity-corrected emission spectra and the standard data issued by the CIE (Commission International de l' Eclairage) in 1931. It was found that the color coordinates for most samples with higher Ag contents fall into the white region in the color space.

  11. Dy3+ doped Lithium Sodium Bismuth Borate Glasses for Yellow Luminescent Photonic Applications

    Directory of Open Access Journals (Sweden)

    M. Parandamaiah,

    2015-08-01

    Full Text Available Lithium sodium bismuth borate glasses-doped with trivalent dysprosium (Dy3+ ions (LSBiB have been prepared by conventional melt-quenching technique and characterized by structural, thermal and spectroscopic measurements. XRD pattern of the host glass confirms its amorphous nature. Morphological and elemental analysis has also been carried out for Dy3+doped LSBiB glass matrix. FTIR spectral analysis confirms the glass formation of the host glass. Optical absorption spectral analysis has been carried out for 0.8 mol% Dy3+ doped LSBiB glass sample. Well defined optical absorption bands are assigned with corresponding electronic transitions. Photoluminescence spectra shows two prominent emission bands centered at 482 nm and 575 nm corresponds to the 4 F9/2 → 6H15/2 and 4 F9/2 → 6H13/2 respectively under the excitation of 452 nm. Among all the concentrations of Dy3+ ions, at 0.8 mol% Dy3+ contained glass sample exhibits prominent yellow emission at 575 nm. Lifetime decay dynamics have been systematically analyzed for all the glasses, higher lifetime is found to be 0.47 ms for 0.8 mol% Dy3+ ions doped glass. From the photoluminescence analysis, Dy3+ contained glass samples could be suggested as potential yellow luminescent glass matrix for several photonic device applications.

  12. 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.

  13. 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.

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

    Science.gov (United States)

    Abdel-Baki, Manal; El-Diasty, Fouad

    2011-10-01

    Lithium tungsten borate glass (0.56- x)B 2O 3-0.4Li 2O- xZnO-0.04WO 3 (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 B 2O 3 the glass molar polarizability increased due to an enhanced unshared oxide ion 2 p 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 1 s 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 B 2O 3, which increase the UV glass transmission window and transmittance.

  15. Microstructure characteristics of high borated stainless steel fabricated by hot-pressing sintering

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Xuan; Wang, Mingjia, E-mail: mingjiawangysu@126.com; Zhao, Hongchang

    2016-04-25

    The present study investigated the microstructure of powder metallurgy (P/M) high borated stainless steel through hot-pressing sintering in a temperature range of 1000–1150 °C within 30 min under 30 MPa. Microstructure and phase examinations were carried out by applying scanning electron microscope, electron backscatter diffraction and X-ray diffraction analysis. The results of as-atomized powders demonstrated that many powders kept egg-type structure with an austenite outer layer and the eutectic borides were much finer than those in traditional cast products. Microstructure studies revealed that borides suffered Ostwald ripening and were significantly influenced by the sintering temperature. Orientation maps indicated that the inter-particle contact areas consisted of equiaxed grains and the regions consisting of large elongated grains partly inherited the microstructure characteristics of as-atomized powder particles. Furthermore, the mechanisms governing the morphological changes in microstructure were discussed. - Highlights: • Near-complete densification could be obtained through hot-pressing sintering. • There was no phase transformation and present phases were M{sub 2}B and austenite. • Borides suffered Ostwald ripening and were significantly influenced by temperature. • Inter-particle contact areas consisted of equiaxed grains for recrystallization. • Deformation-free zones exhibited elongated grains for dendritic arms coarsening.

  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. Complexation of Nickel Ions by Boric Acid or (Poly)borates.

    Science.gov (United States)

    Graff, Anais; Barrez, Etienne; Baranek, Philippe; Bachet, Martin; Bénézeth, Pascale

    2017-01-01

    An experiment based on electrochemical reactions and pH monitoring was performed in which nickel ions were gradually formed by oxidation of a nickel metal electrode in a solution of boric acid. Based on the experimental results and aqueous speciation modeling, the evolution of pH showed the existence of significant nickel-boron complexation. A triborate nickel complex was postulated at high boric acid concentrations when polyborates are present, and the equilibrium constants were determined at 25, 50 and 70 °C. The calculated enthalpy and entropy at 25 °C for the formation of the complex from boric acid and Ni(2+) ions are respectively equal to (65.6 ± 3.1) kJ·mol(-1) and (0.5 ± 11.1) J·K(-1)·mol(-1). The results of this study suggest that complexation of nickel ions by borates can significantly enhance the solubility of nickel metal and nickel oxide depending on the concentration of boric acid and pH. First principles calculations were investigated and tend to show that the complex is thermodynamically stable and the nickel cation in solution should interact more strongly with the [Formula: see text] than with boric acid.

  18. 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

  19. Thermoluminescence properties of lithium magnesium borate glasses system doped with dysprosium oxide.

    Science.gov (United States)

    Mhareb, M H A; Hashim, S; Ghoshal, S K; Alajerami, Y S M; Saleh, M A; Razak, N A B; Azizan, S A B

    2015-12-01

    We report the impact of dysprosium (Dy(3+)) dopant and magnesium oxide (MgO) modifier on the thermoluminescent properties of lithium borate (LB) glass via two procedures. The thermoluminescence (TL) glow curves reveal a single prominent peak at 190 °C for 0.5 mol% of Dy(3+). An increase in MgO contents by 10 mol% enhances the TL intensity by a factor of 1.5 times without causing any shift in the maximum temperature. This enhancement is attributed to the occurrence of extra electron traps created via magnesium and the energy transfer to trivalent Dy(3+) ions. Good linearity in the range of 0.01-4 Gy with a linear correlation coefficient of 0.998, fading as low as 21% over a period of 3 months, excellent reproducibility without oven annealing and tissue equivalent effective atomic numbers ~8.71 are achieved. The trap parameters, including geometric factor (μg), activation energy (E) and frequency factor (s) associated with LMB:Dy are also determined. These favorable TL characteristics of prepared glasses may contribute towards the development of Li2O-MgO-B2O3 radiation dosimeters.

  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. Use of borated polyethylene to improve low energy response of a prompt gamma based neutron dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Priyada, P.; Ashwini, U.; Sarkar, P.K., E-mail: pradip.sarkar@manipal.edu

    2016-05-21

    The feasibility of using a combined sample of borated polyethylene and normal polyethylene to estimate neutron ambient dose equivalent from measured prompt gamma emissions is investigated theoretically to demonstrate improvements in low energy neutron dose response compared to only polyethylene. Monte Carlo simulations have been carried out using the FLUKA code to calculate the response of boron, hydrogen and carbon prompt gamma emissions to mono energetic neutrons. The weighted least square method is employed to arrive at the best linear combination of these responses that approximates the ICRP fluence to dose conversion coefficients well in the energy range of 10{sup −8} MeV to 14 MeV. The configuration of the combined system is optimized through FLUKA simulations. The proposed method is validated theoretically with five different workplace neutron spectra with satisfactory outcome. - Highlights: • An improved method is proposed for estimating H⁎(10) using prompt gamma emissions. • A combination of BHDPE and HDPE cylinders is used as a sample. • Linear combination of prompt gamma intensities approximates ICRP-DCC closely. • Feasibility of the method was tested theoretically using workplace neutron spectra.

  2. Magnetoelectric effect in ytterbium aluminum borate YbAl3(BO3)4

    Science.gov (United States)

    Ivanov, V. Yu.; Kuzmenko, A. M.; Mukhin, A. A.

    2017-04-01

    The anisotropic magnetoelectric properties of an ytterbium aluminum borate YbAl (BO single crystal having noncentrosymmetric crystal structure (space group R32) are studied, including the orientational, field, and temperature dependences of the polarization in magnetic fields up to 5 T in the temperature range of 2-300 K. It has been shown experimentally for the first time that the symmetry of the observed magnetoelectric effects exactly corresponds to the trigonal structure of the crystal and is characterized by two quadratic magnetoelectric constants. The polarization in the basal plane P a, b is a quadratic function of the field at low fields and reaches 250-300 μC/m2 in a field of 5 T at a temperature of 2 K, almost an order of magnitude exceeding the previously reported values. A theoretical model based on the spin Hamiltonian of the ground Kramers doublet of Yb3+ ions in the crystal field is proposed including magnetoelectric interactions allowed by the symmetry. This model makes it possible to quantitatively describe all observed magnetic and magnetoelectric properties of YbAl3(BO3)4.

  3. 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.

  4. Fabrication and characterization of poly (bisphenol A borate) with high thermal stability

    Science.gov (United States)

    Wang, Shujuan; Wang, Xiao; Jia, Beibei; Jing, Xinli

    2017-01-01

    In this work, poly (bisphenol A borate) (PBAB), which has excellent thermal resistance and a high char yield, was synthesized via a convenient A2 + B3 strategy by using bisphenol A (BPA) and boric acid (BA). The chemical reaction between BPA and BA and the chemical structure of PBAB were investigated. The results demonstrate that PBAB consists of aromatic, Ph-O-B and B-O-B structures, as well as a small number of boron hydroxyl groups and phenolic hydroxyl groups. The thermal properties of PBAB were studied by DMA and TGA. The results indicate that the glass transition temperature and char yield are gradually enhanced by increasing the boron content, where the char yield of PBAB at 800 °C in nitrogen (N2) reaches up to 71.3%. It is of particular importance that PBAB show excellent thermal resistance in N2 and air atmospheres. By analysing the pyrolysis of PBAB, the high char yield of PBAB can be attributed to the formation of boron oxide and boron carbide at high temperatures, which reduced the release of volatile carbon dioxide and improved the thermal stability of the carbonization products. This study provides a new perspective on the design of novel boron-containing polymers and possesses significant potential for the improvement of the comprehensive performance of thermosetting resins to broaden their applicability in the field of advanced composites.

  5. Optical and shielding behavior studies of vanadium-doped lead borate glasses

    Science.gov (United States)

    Abdelghany, A. M.; ElBatal, H. A.; Marei, L. K.

    2012-01-01

    A glass sample of composition PbO 42.1%- B2O3 57.9 mol% B2O3 together with samples of the same composition doped with varying V2O5 contents was prepared via melt annealing technique. X-ray diffraction technique was applied to prove the amorphous nature of the prepared glasses. UV-visible absorption spectra were measured in the range 200-1500 nm before and after successive gamma irradiation, which were applied to evaluate optical properties, including direct and indirect optical energy band gaps before and after gamma irradiation. Undoped glass sample is observed to exhibit strong UV absorption; due to the combined contributions of absorption of both Pb2+ ions and trace iron impurities. The presence of V3+ ions together with the other vanadium valence states (V4+, V5+) was proved by the appearance of extra visible absorption bands. Infrared absorption spectra were measured in the range 4000-400 cm-1 which revealed the presence of both triangular and tetrahedral borate groups besides the sharing of lead ions.

  6. Optical characterization of Cu2+ ion-doped zinc lead borate glasses

    Science.gov (United States)

    Thulasiramudu, A.; Buddhudu, S.

    2006-01-01

    We have developed a new series of zinc lead borate (ZLB) glasses by varying ZnO content, to enhance UV transmission, in the chemical composition of xZnO 15PbO (85-x)B2O3, where x=0, 5, 10, 15, 20, 25, 30, 35, 40 and 45 mol% ZnO. From the measurement of UV absorption spectra both the direct and indirect band gaps have been evaluated. Also different physical properties of a reference glass of 45ZnO 15PbO 40B2O3 have been studied. From the measurement of refractive indices at six different wavelengths, Cauchy's constants (A=1.578743209; B=131832.33nm and C=-0.77756×10nm) have been computed and a satisfactory correlation has been achieved between the theoretical and the experimental results. Absorption spectra of Cu2+(45-x)ZnO 15PbO 40B2O3 (where x=0.1, 0.2, 0.5 and 1.0 mol%) have shown two absorption bands at 428 nm (2B1g→2Eg) and 777 nm (2B1g→2B2g). Emission spectra of (1.0 mol%) Cu2+:ZLB have revealed two emission transitions at 400 and 493 nm with excitations at 288 and 316 nm.

  7. 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.

  8. Role of iron addition on structure and electrical and magnetic properties of lithium lead borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Farouk, H. [Al-Azhar Univ, Cairo (Egypt). Dept. of Phys.; Solimani, A.A. [Ain Shams Univ., Cairo (Egypt). Dept. of Physics; Aly, S.A. [Al-Azhar Univ, Cairo (Egypt). Dept. of Phys.; El-Deen, H.Z. [Al-Azhar Univ, Cairo (Egypt). Dept. of Phys.; Kashif, I. [Al-Azhar Univ, Cairo (Egypt). Dept. of Phys.; Sanad, A.M. [Al-Azhar Univ, Cairo (Egypt). Dept. of Phys.

    1996-04-01

    The effect of iron oxide addition on the structure and electrical and magnetic properties of lithium lead borate glasses was studied using IR transmission spectra, optical absorption techniques, electrical conductivity, magnetic susceptibility measurements and differential thermal analysis (DTA). IR transmission spectra showed that the addition of up to 3 mol.% iron oxide to the samples introduced as modifiers at the expense of Pb ions. When the amount of iron oxide is increased to more than 3 mol.%, the iron enters the glass structure as network former with an FeO{sub 4} structure. The optical absorption properties of glass samples containing different amounts of iron oxide indicated that the oxidation state and the coordination of the doping ions are octahedral. At high contents of iron oxide, some of the iron ions exist in a tetrahedral form. The electrical conductivities as a function of temperature for glass samples containing different amounts of iron oxide up to 10 mol.% Fe{sub 2}O{sub 3} have similar behaviours, from which we deduced the activation energy for each sample. The investigation of the magnetic susceptibility as a function of Fe{sub 2}O{sub 3} concentration concluded that, for high amounts of iron ions, the iron ions exist in an octahedral coordination rather then in a tetrahedral coordination. DTA showed that the samples containing up to 5 mol.% iron oxide are characterized by one crystallization temperature, while samples containing 10 mol.% iron oxide have two crystallization temperatures. (orig.)

  9. Optical characterization of Eu 3+ and Tb 3+ 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 Eu 3+ or Tb 3+ 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 Eu 3+ glass has revealed five transitions ( 5D 0 → 7F 0, 7F 1, 7F 2, 7F 3 and 7F 4) at 578, 591, 613, 654 and 702 nm, respectively, with λexci = 392 nm ( 7F 0 → 5L 6). In the case of Tb 3+:ZLB glass, four emission transitions such as ( 5D 4→ 7F 6, 7F 5, 7F 4 and 7F 3) that are located at 489, 542, 585 and 622 nm, respectively, have been measured with λexci = 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.

  10. Optical absorption and fluorescence properties of Er3+/Yb3+ codoped lead bismuth alumina borate glasses

    Science.gov (United States)

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

    2014-04-01

    Lead bismuth alumina borate glasses codoped with Er3+/Yb3+ were prepared by melt quenching technique. Optical absorption, FTIR and photoluminescence spectra of these glasses have been studied. Judd-Ofelt theory has been applied to to the f ↔ f transitions for evaluating Ω2, Ω4 and Ω6 parameters. Radiative properties like branching ratio βr and the radiative life time τR have been determined on the basis of Judd-Ofelt theory. Upconversion emissions have been observed under 980nm laser excitation at room temperature. Green and red up-conversion emissions are centered at 530, 550 and 656 nm corresponding to 2H11/2→4I15/2, 4S3/2→4I15/2 and 4F9/2→4I15/2 transitions of Er3+ respectively. The results obtained are discussed quantitatively based on the energy transfer between Yb3+ and Er3+.

  11. Ho3+-doped strontium-aluminium-bismuth-borate glasses for green light emission.

    Science.gov (United States)

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

    2014-11-01

    Strontium-aluminium-bismuth-borate glasses (SAlBiB) doped with different concentrations of Ho(3+) were prepared using conventional melt quenching technique and their structural and optical properties investigated. X-ray diffraction and scanning electron microscopy analysis were used to study the structural properties. Optical properties were studied by measuring the optical absorption and visible luminescence spectra. The Judd-Ofelt (J-O) theory was applied to evaluate J-O intensity parameters, Ω(λ) (λ = 2, 4 and 6). Using J-O intensity parameters, radiative properties such as spontaneous transition probabilities (A(R)), branching ratios (β(R)) and radiative lifetimes (τ(R)) were determined. From the emission spectra, a strong green emission nearly at 549 nm corresponding to the transition, (5)S2 ((5)F4)→(5)I(8) was observed. Emission peak positions (λ(P)), effective bandwidths (Δλ(eff)) and stimulated emission cross-sections (σ(p)) were calculated for the observed emission transitions, (5)F3 →(5)I(8), (5)S2((5)F4)→(5)I(8) and (5)F5 →(5)I(8) of Ho(3+) in all the glass matrices. Chromaticity color coordinates were calculated using the emission spectra. The experimental results suggest that SAlBiB glass matrix with 1.5 mol% of Ho(3+) has better emission properties.

  12. 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

  13. FTIR AND SOME PHYSICAL PROPERTIES OF ALKALINE EARTH BORATE GLASSES CONTAINING HEAVY METAL OXIDES

    Directory of Open Access Journals (Sweden)

    RAMADEVUDU.G

    2011-09-01

    Full Text Available The FTIR spectra of heavy metal oxide doped borate glasses with the general formula RO-MO-B2O3 (RO= MgO, CaO, SrO and BaO, MO=ZnO, TeO2, PbO and Bi2O3 were studied in the spectral range 400-4400cm-1 toobtain information about the influence of the glass composition on the spectra. The FTIR studies revealed that MO acted differently in RO-B2O3 glass matrix and produced small variations in the glass structure. RO oxides also affected the glass structure slightly due to mixed oxide effect. However the structural groupings present ineach series of glasses are not much affected by the composition. The effect of composition on some physical properties like density, molar volume was also carried out. The increase in the values of physical parameters such as density and glass transition temperature is attributed to conversion of [BO3]3- triangular units into BO4-tetrahedral units.

  14. Oxidation of ethyl ether on borate glass: chemiluminescence, mechanism, and development of a sensitive gas sensor.

    Science.gov (United States)

    Hu, Jing; Xu, Kailai; Jia, Yunzhen; Lv, Yi; Li, Yubao; Hou, Xiandeng

    2008-11-01

    A gas sensor was developed by using the chemiluminescence (CL) emission from the oxidation of ethyl ether by oxygen in the air on the surface of borate glass. Theoretical calculation, together with experimental investigation, revealed the main CL reactions: ethyl ether is first oxidized to acetaldehyde and then to acetic acid, during which main luminous intermediates such as CH 3CO (*) are generated and emit light with a peak at 493 nm. At a reaction temperature of 245 degrees C, the overall maximal emission was found at around 460 nm, and the linear range of the CL intensity versus the concentration of ethyl ether was 0.12-51.7 microg mL (-1) ( R = 0.999, n = 7) with a limit of detection (3sigma) of 0.04 microg mL (-1). Interference from foreign substances including alcohol (methanol, ethanol and isopropanol), acetone, ethyl acetate, n-hexane, cyclohexane, dichloromethane, or ether ( n-butyl ether, tetrahydrofuran, propylene oxide, isopropyl ether and methyl tert-butyl ether) was not significant except a minimal signal from n-butyl ether (ethyl ether.

  15. Substituted benzotriazoles as inhibitors of copper corrosion in borate buffer solutions

    Science.gov (United States)

    Agafonkina, M. O.; Andreeva, N. P.; Kuznetsov, Yu. I.; Timashev, S. F.

    2017-08-01

    The adsorption of substituted 1,2,3-benzotriazoles (R-BTAs) onto copper is measured via ellipsometry in a pure borate buffer (pH 7.4) and satisfactorily described by Temkin's isotherm. The adsorption free energy (-Δ G a 0 ) values of these azoles are determined. The (-Δ G a 0 ) values are found to rise as their hydrophobicity, characterized by the logarithm of the partition coefficient of a substituted BTA in a model octanol-water system (log P), grows. The minimum concentration sufficient for the spontaneous passivation of copper ( C min) and a shift in the potential of local copper depassivation with chlorides ( E pt) after an azole is added to the solution (i.e., Δ E = E pt in - E pt backgr characterizing the ability of its adsorption to stabilize passivation) are determined in the same solution containing a corrosion additive (0.01M NaCl) for each azole under study. Both criteria of the passivating properties of azoles (log C min and Δ E) are shown to correlate linearly with log P, testifying to the role played by surface activity of this family of organic inhibitors in protecting copper in an aqueous solution.

  16. 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.

  17. High-Pressure Synthesis of Cd(NH₃)₂[B₃O₅(NH₃)]₂: Pioneering the Way to the Substance Class of Ammine Borates.

    Science.gov (United States)

    Sohr, Gerhard; Ciaghi, Nina; Schauperl, Michael; Wurst, Klaus; Liedl, Klaus R; Huppertz, Hubert

    2015-05-18

    To date, the access to the substance class of borates containing nitrogen, for example, nitridoborates, oxonitridoborates, or amine borates, was an extreme effort owing to the difficult starting materials and reaction conditions. Although a number of compounds containing boron and nitrogen are known, no adduct of ammonia to an inorganic borate has been observed so far. A new synthetic approach starting from the simple educts CdO, B2O3, and aqueous ammonia under conditions of 4.7 GPa and 800 °C led to the synthesis of Cd(NH3)2[B3O5(NH3)]2 as the first ammine borate. We thoroughly characterized this compound on the basis of low-temperature single-crystal and powder X-ray diffraction data, IR and Raman spectroscopy, and by quantum theoretical calculations. This contribution shows that the adduct of NH3 to the BO3 group of a complex B-O network can be stabilized, opening up a fundamentally new synthetic route to nitrogen-containing borates.

  18. REVIEW OF THE OCCURRENCE OF TWO NEW MINERALS IN THE EMET BORATE DEPOSIT, TURKEY: EMETITE, Ca7Na3K(SO4)9, and FONTARNAUITE, Na2Sr(SO4)[B5O8(OH)](H2O)2

    OpenAIRE

    Helvaci, Cahit

    2015-01-01

    The Emet borate deposit is situated in the middle of the known borate deposits of western Anatolia. Emet is the world biggest colemanite-probertite deposit which is located in the upper section of the volcano-sedimentary sequence of the Emet basin. Emet borate deposit is unique and has unusual mineral associations. The principal minerals in the Emet borate deposit are colemanite with minor probertite, ulexite and hydroboracite. In addition, rare species such as meyerhofferite, veatchite-A, tu...

  19. Kombinasi Boraks dan Asam Borat sebagai Bahan Penghambat Api dan Antirayap Pada Kayu Meranti Merah

    Directory of Open Access Journals (Sweden)

    Mahdi Santoso

    2015-01-01

    Full Text Available Kayu mempunyai sifat yang mudah terbakar dan sebagian besar mempunyai keawetan alami yang rendah. Perbaikan kualitas kayu dilakukan untuk mengatasi kelemahan tersebut, salah satunya dengan mengimpregnasikan bahan kimia yang bersifat menghambat api dan beracun terhadap organisme perusak kayu. Tujuan penelitian ini adalah melihat kemampuan boraks:asam borat (1:1 untuk meningkatkan ketahanan kayu meranti merah terhadap api dan rayap kayu kering dan mengetahui proses pengawetan yang efektif. Penelitian ini menggunakan kayu meranti merah (Shorea spp berukuran 6 x 15 x 500 cm. Waktu pengawetan adalah 1, 2, dan 3 jam serta konsentrasi bahan pengawet 7% dalam 5 ulangan. Metode pengawetan menggunakan metode sel kosong dengan tekanan 12 kg/cm2 . Pengujian ketahanan terhadap api mengacu pada ASTM E 69-02 prosedur B, pengujian ketahanan terhadap rayap kayu kering mengacu pada metode rayap makan tanpa pilihan. Parameter yang diamati ialah absorpsi, retensi aktual, intensitas bakar, suhu pembakaran maksimal, lama pembaraan, mortalitas rayap kayu kering, pengurangan berat contoh uji, derajat kerusakan dan kondisi fisik sampel setelah uji bakar. Hasil penelitian menunjukkan bahwa kombinasi boraks:asam borat (1:1 memiliki efektivitas yang tinggi untuk meningkatkan ketahanan kayu meranti merah terhadap api dan rayap kayu kering. Proses pengawetan yang paling efektif adalah lama penekanan 2 jam dengan absorpsi 331 kg/m3 ; retensi aktual 28,8 kg/m3 ; intensitas bakar 10,9%; suhu pembakaran maksimal 140ºC; lama pembaraan 1,03 menit; mortalitas rayap kayu kering 100%; pengurangan berat contoh uji 0,002%; serta derajat kerusakan kategori ringan. Katakunci: penghambat api, anti rayap, boraks, Shorea spp, Cryptotermes cynocephalus   Borax and Boric Acid Combination As Fire Retardant and Anti-termite Agents on Red Meranti Wood Abstract Woods have properties which are easy to be ignited by fire and most of them have a low natural durability. Therefore, it is required to

  20. 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.

  1. Study of structural and spectroscopic behavior of Sm3+ ions in lead-zinc borate glasses containing alkali metal ions

    Science.gov (United States)

    Sasi Kumar, M. V.; Babu, S.; Rajeswara Reddy, B.; Ratnakaram, Y. C.

    2017-06-01

    High luminescence behavior of rare earth inorganic glasses have a variety of uses in the industry. In the past few decades, rare earth ions with characteristic photonics applications are being hosted by heavy metal oxide glasses. Among the rare earth ions Sm3+ ion has features which make it apt for high density optical storage. The authors of the paper have experimented to synthesize Sm3+ doped glasses. In this regard a new series of borate glasses doped with 1 mol% Sm3+ ion are developed by using melt-quenching technique. XRD, FTIR, optical absorption, luminescence techniques are used to study the various characteristics of Sm3+ ion in the present glass matrices. The XRD spectra confirms the amorphous nature of glasses. Further, the researchers have used differential thermal analysis to study the glass transition temperature. The structural groups in the prepared glasses are studied using Fourier transform infrared spectra. From the measurement of its optical absorption, three phenomenological Judd-Ofelt intensity parameters (Ω2, Ω4 and Ω6) have been computed. Based on these Judd-Ofelt intensity parameters, radiative properties such as radiative probabilities (Arad), branching ratios (β), and radiative life time (τR) are calculated. The excitation spectra of Sm3+ doped lithium heavy metal borate glass matrix is recorded under the emission wavelength of 600 nm. The emission spectra are recorded under 404 nm excitation wavelength. From various emission transitions, 4G5/2 → 6H7/2 and 4G5/2 → 6H9/2 bands could be of interest for various applications. The decay profiles of 4G5/2 level exhibit single exponential nature in all the prepared glass matrices. The potassium glass matrix exhibits higher quantum efficiency than the other glass matrices. Finally, by going through these several spectroscopic characterizations, it is concluded that the prepared Sm3+ doped lead-zinc borate glasses might be useful for visible light applications.

  2. High-Pressure Synthesis and Characterization of New Actinide Borates, AnB4O8 (An=Th, U)

    Science.gov (United States)

    Hinteregger, Ernst; Hofer, Thomas S; Heymann, Gunter; Perfler, Lukas; Kraus, Florian; Huppertz, Hubert

    2013-01-01

    New actinide borates ThB4O8 and UB4O8 were synthesized under high-pressure, high-temperature conditions (5.5 GPa/1100 °C for thorium borate, 10.5 GPa/1100 °C for the isotypic uranium borate) in a Walker-type multianvil apparatus from their corresponding actinide oxide and boron oxide. The crystal structure was determined on basis of single-crystal X-ray diffraction data that were collected at room temperature. Both compounds crystallized in the monoclinic space group C2/c (Z=4). Lattice parameters for ThB4O8: a=1611.3(3), b=419.86(8), c=730.6(2) pm; β=114.70(3)°; V=449.0(2) Å3; R1=0.0255, wR2=0.0653 (all data). Lattice parameters for UB4O8: a=1589.7(3), b=422.14(8), c=723.4(2) pm; β=114.13(3)°; V=443.1(2) Å3; R1=0.0227, wR2=0.0372 (all data). The new AnB4O8 (An=Th, U) structure type is constructed from corner-sharing BO4 tetrahedra, which form layers in the bc plane. One of the four independent oxygen atoms is threefold-coordinated. The actinide cations are located between the boron–oxygen layers. In addition to Raman spectroscopic investigations, DFT calculations were performed to support the assignment of the vibrational bands. PMID:24123698

  3. High-pressure synthesis and characterization of new actinide borates, AnB4O8 (An=Th, U).

    Science.gov (United States)

    Hinteregger, Ernst; Hofer, Thomas S; Heymann, Gunter; Perfler, Lukas; Kraus, Florian; Huppertz, Hubert

    2013-11-18

    New actinide borates ThB4O8 and UB4O8 were synthesized under high-pressure, high-temperature conditions (5.5 GPa/1100 °C for thorium borate, 10.5 GPa/1100 °C for the isotypic uranium borate) in a Walker-type multianvil apparatus from their corresponding actinide oxide and boron oxide. The crystal structure was determined on basis of single-crystal X-ray diffraction data that were collected at room temperature. Both compounds crystallized in the monoclinic space group C2/c (Z=4). Lattice parameters for ThB4O8: a=1611.3(3), b=419.86(8), c=730.6(2) pm; β=114.70(3)°; V=449.0(2) Å(3); R1=0.0255, wR2=0.0653 (all data). Lattice parameters for UB4O8: a=1589.7(3), b=422.14(8), c=723.4(2) pm; β=114.13(3)°; V=443.1(2) Å(3); R1=0.0227, wR2=0.0372 (all data). The new AnB4O8 (An=Th, U) structure type is constructed from corner-sharing BO4 tetrahedra, which form layers in the bc plane. One of the four independent oxygen atoms is threefold-coordinated. The actinide cations are located between the boron-oxygen layers. In addition to Raman spectroscopic investigations, DFT calculations were performed to support the assignment of the vibrational bands.

  4. Report of the key comparison APMP.QM-K19. APMP comparison on pH measurement of borate buffer

    Science.gov (United States)

    Hioki, Akiharu; Asakai, Toshiaki; Maksimov, Igor; Suzuki, Toshihiro; Miura, Tsutomu; Obromsook, Krairerk; Tangpaisarnkul, Nongluck; Rodruangthum, Patumporn; Wong, Siu-Kay; Lam, Wai-Hing; Zakaria, Osman; Anuar Mohd. Amin, Khirul; Thanh, Ngo Huy; Máriássy, Michal; Vyskocil, Leos; Hankova, Zuzana; Fisicaro, Paola; Stoica, Daniela; Singh, Nahar; Soni, Daya; Ticona Canaza, Galia; Kutovoy, Viatcheslav; Barbieri Gonzaga, Fabiano; Dias, Júlio Cesar; Vospelova, Alena; Bakovets, Nickolay; Zhanasbayeva, Bibinur

    2015-01-01

    The APMP.QM-K19 was organised by TCQM of APMP to test the abilities of the national metrology institutes in the APMP region to measure a pH value of a borate buffer. This APMP comparison on pH measurement was proposed by the National Metrology Institute of Japan (NMIJ) and the National Institute of Metrology (Thailand) (NIMT) at the APMP-TCQM meeting held 26-27 November 2012. After approval by TCQM, the comparison has been conducted by NMIJ and NIMT. The comparison is a key comparison following CCQM-K19 and CCQM-K19.1. The comparison material was a borate buffer of pH around 9.2 and the measurement temperatures were 15 °C, 25 °C and 37 °C. This is the second APMP key comparison on pH measurement and the fourth APMP comparison on pH measurement following APMP.QM-P06 (two phosphate buffers) in 2004, APMP.QM-P09 (a phthalate buffer) in 2006 and APMP.QM-K9/APMP.QM-P16 (a phosphate buffer) in 2010-2011. The results can be used further by any participant to support its CMC claim at least for a borate buffer. That claim will concern the pH method employed by the participant during this comparison and will cover the used temperature(s) or the full temperature range between 15°C and 37 °C for the participant which measured pH values at the three temperatures. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  5. 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.

  6. Optical properties of dy doped lead and bismuth borate glasses - effect of glass composition, metal and semiconducting nanoparticles

    Science.gov (United States)

    Ooi, Hio Giap

    The optical properties of Dy3+ ions in lead borate and bismuth borate glasses are studied as a function of glass composition with PbO content (29.5 to 69.5mol%) and Bi2O3 content (29.5 to 59.5 mol%). We also studied the effect of metal and semiconducting nanoparticles on the absorption and fluorescence emission of Dy3+ ions in both lead and bismuth borate glasses. The absorption coefficient at each wavelength is obtained from the optical absorption spectrum of a glass sample, and the number density of rare-earth (RE) ions is calculated from the measurement of the glass density. These two parameters are then used to calculate the oscillator strength of each transition using Judd-Ofelt theory. Using the oscillator strength for each transition, we obtained the intensity parameters which represent changes in the symmetry of the ligand field at the Dy 3+ site (due to structural group changes and changes in Dy-O covalency). Radiative transition probabilities, the radiative lifetime of the excited states and the branching ratios are then obtained from these intensity parameters. The fluorescence spectra, obtained using 355 nm and 458 nm laser excitation, are analyzed by determining the area ratio of yellow/blue (Y/B) peaks and the wavelength of the hypersensitive transition (HST). The compositional dependence and effect of nanoparticles on the stimulated emission cross-section (sigmap), are then evaluated using radiative transition probability, the refractive index of the host glass, effective fluorescence linewidth, and the position of the band. In all of the glass systems, it was found that the optical properties are strongly influenced by structural changes arising from compositional variation and size of nanoparticles. Dy 3+ transitions exhibit large sigmap suggesting the possible utilization of these materials in laser applications.

  7. Study of structural and spectroscopic behavior of Sm3+ ions in lead-zinc borate glasses containing alkali metal ions

    Science.gov (United States)

    Sasi Kumar, M. V.; Babu, S.; Rajeswara Reddy, B.; Ratnakaram, Y. C.

    2017-02-01

    High luminescence behavior of rare earth inorganic glasses have a variety of uses in the industry. In the past few decades, rare earth ions with characteristic photonics applications are being hosted by heavy metal oxide glasses. Among the rare earth ions Sm3+ ion has features which make it apt for high density optical storage. The authors of the paper have experimented to synthesize Sm3+ doped glasses. In this regard a new series of borate glasses doped with 1 mol% Sm3+ ion are developed by using melt-quenching technique. XRD, FTIR, optical absorption, luminescence techniques are used to study the various characteristics of Sm3+ ion in the present glass matrices. The XRD spectra confirms the amorphous nature of glasses. Further, the researchers have used differential thermal analysis to study the glass transition temperature. The structural groups in the prepared glasses are studied using Fourier transform infrared spectra. From the measurement of its optical absorption, three phenomenological Judd-Ofelt intensity parameters (Ω2, Ω4 and Ω6) have been computed. Based on these Judd-Ofelt intensity parameters, radiative properties such as radiative probabilities (Arad), branching ratios (β), and radiative life time (τR) are calculated. The excitation spectra of Sm3+ doped lithium heavy metal borate glass matrix is recorded under the emission wavelength of 600 nm. The emission spectra are recorded under 404 nm excitation wavelength. From various emission transitions, 4G5/2 → 6H7/2 and 4G5/2 → 6H9/2 bands could be of interest for various applications. The decay profiles of 4G5/2 level exhibit single exponential nature in all the prepared glass matrices. The potassium glass matrix exhibits higher quantum efficiency than the other glass matrices. Finally, by going through these several spectroscopic characterizations, it is concluded that the prepared Sm3+ doped lead-zinc borate glasses might be useful for visible light applications.

  8. Bone regeneration in rat calvarial defects implanted with fibrous scaffolds composed of a mixture of silicate and borate bioactive glasses.

    Science.gov (United States)

    Gu, Yifei; Huang, Wenhai; Rahaman, Mohamed N; Day, Delbert E

    2013-11-01

    Previous studies have evaluated the capacity of porous scaffolds composed of a single bioactive glass to regenerate bone. In the present study, scaffolds composed of a mixture of two different bioactive glasses (silicate 13-93 and borate 13-93B3) were created and evaluated for their response to osteogenic MLO-A5 cells in vitro and their capacity to regenerate bone in rat calvarial defects in vivo. The scaffolds, which have similar microstructures (porosity=58-67%) and contain 0, 25, 50 and 100 wt.% 13-93B3 glass, were fabricated by thermally bonding randomly oriented short fibers. The silicate 13-93 scaffolds showed a better capacity to support cell proliferation and alkaline phosphatase activity than the scaffolds containing borate 13-93B3 fibers. The amount of new bone formed in the defects implanted with the 13-93 scaffolds at 12 weeks was 31%, compared to values of 25, 17 and 20%, respectively, for the scaffolds containing 25, 50 and 100% 13-93B3 glass. The amount of new bone formed in the 13-93 scaffolds was significantly higher than in the scaffolds containing 50 and 100% 13-93B3 glass. While the 13-93 fibers were only partially converted to hydroxyapatite at 12 weeks, the 13-93B3 fibers were fully converted and formed a tubular morphology. Scaffolds composed of an optimized mixture of silicate and borate bioactive glasses could provide the requisite architecture to guide bone regeneration combined with a controllable degradation rate that could be beneficial for bone and tissue healing.

  9. Spectroscopic investigation on europium doped heavy metal borate glasses for red luminescent application

    Energy Technology Data Exchange (ETDEWEB)

    Hegde, Vinod; Wagh, Akshatha; Kamath, Sudha D. [Manipal University, Department of Physics, Manipal Institute of Technology, Manipal (India); Hegde, Hemanth [Manipal University, Department of Chemistry, Manipal Institute of Technology, Manipal (India); Vishwanath, C.S.D. [Sri Venkateswara University, Department of Physics, Tirupati (India)

    2017-05-15

    The present study explores a new borate family glasses based on 10ZnO-5Na{sub 2}O-10Bi{sub 2}O{sub 3}-(75 - x) B{sub 2}O{sub 3}-xEu{sub 2}O{sub 3} (x = 0, 0.1, 0.5, 1, 1.5, 2, 3 mol%) composition, synthesized by rapid melt quench technique. Prepared glasses were subjected to the density and refractive index measurements and their values were used to calculate other physical properties of the glass matrix as a function of Eu{sup 3+} concentration. XRD confirmed amorphous nature of the glasses. FTIR spectra in the absorption mode were recorded in the 400-4000 cm{sup -1} region to identify different functional groups in the glass matrix. Deconvoluted FTIR spectra showed increase in BO{sub 4} units with rise in europium content which confirmed the 'network strengthener' role of europium ions by creating bridging oxygens (BOs). Optical properties were investigated for their luminescence behavior through various spectroscopic techniques such as UV-Vis-NIR absorption, excitation, emission, decay profiles, and color measurements at room temperature. Lasing properties of the glasses like total radiative life time, branching ratio, emission cross section, and optical gain were obtained from the calculated Judd-Ofelt (Ω{sub 2},Ω{sub 4}) intensity parameters. From the measured values of emission, cross sections, branching ratios, life times, strong photoluminescence features, and CIE chromaticity coordinates, 0.5 mol% of Eu{sup 3+} ions doped ZnNaBiB glasses showed optimum performance and are potential candidate for red light generation at 613 nm. (orig.)

  10. Hydrogen Storage Characteristics of Metal Hydro-Borate and Transition Element-Added Magnesium Hydride

    Energy Technology Data Exchange (ETDEWEB)

    Song, Myoung Youp; Kwak, Young Jun [Chonbuk National University, Jeonju (Korea, Republic of); Park, Hye Ryoung [Chonnam National University, Gwangju (Korea, Republic of)

    2016-07-15

    A metal hydro-borate Zn(BH{sub 4}){sub 2} was prepared by milling ZnCl{sub 2} and NaBH{sub 4} in a planetary ball mill in an Ar atmosphere. This sample contained NaCl. 95 wt% MgH{sub 2}-2.5 wt% Zn(BH{sub 4}){sub 2}-2.5 wt% Ni samples [named MgH{sub 2}-2.5Zn(BH{sub 4}){sub 2}-2.5Ni] were then prepared by milling in a planetary ball mill in a hydrogen atmosphere. The hydrogen absorption and release properties of the prepared samples were investigated. In particular, variations in the initial hydriding and dehydriding rates with temperature were examined. MgH{sub 2}-2.5Zn(BH{sub 4}){sub 2}-2.5Ni dehydrided at the fourth cycle contained Mg, MgO, and small amounts of β-MgH2 and Mg2Ni. The sample after hydriding-dehydriding cycling had a slightly smaller average particle size and a larger BET specific surface area than the sample after milling. Increasing the temperature from 573 K to 623 K led to a decrease in the initial hydriding rate. The initial dehydriding rate increased as the temperature increased from 573 K to 643 K. At 573 K under 12 bar H{sub 2}, the sample absorbed 3.85 wt% H for 2.5 min, 4.60 wt% H for 5 min, 4.64 wt% H for 10 min, and 4.80 wt% H for 60 min. The MgH{sub 2}-2.5Zn(BH{sub 4}){sub 2}-2.5Ni had an effective hydrogen storage capacity (the quantity of hydrogen absorbed for 60 min) of near 5 wt% (4.96 wt% at 593 K).

  11. Spectroscopic investigation on europium doped heavy metal borate glasses for red luminescent application

    Science.gov (United States)

    Hegde, Vinod; Wagh, Akshatha; Hegde, Hemanth; Vishwanath, C. S. Dwaraka; Kamath, Sudha D.

    2017-05-01

    The present study explores a new borate family glasses based on 10ZnO-5Na2O-10Bi2O3-(75 - x) B2O3- xEu2O3 ( x = 0, 0.1, 0.5, 1, 1.5, 2, 3 mol%) composition, synthesized by rapid melt quench technique. Prepared glasses were subjected to the density and refractive index measurements and their values were used to calculate other physical properties of the glass matrix as a function of Eu3+ concentration. XRD confirmed amorphous nature of the glasses. FTIR spectra in the absorption mode were recorded in the 400-4000 cm-1 region to identify different functional groups in the glass matrix. Deconvoluted FTIR spectra showed increase in BO4 units with rise in europium content which confirmed the `network strengthener' role of europium ions by creating bridging oxygens (BOs). Optical properties were investigated for their luminescence behavior through various spectroscopic techniques such as UV-Vis-NIR absorption, excitation, emission, decay profiles, and color measurements at room temperature. Lasing properties of the glasses like total radiative life time, branching ratio, emission cross section, and optical gain were obtained from the calculated Judd-Ofelt (Ω2,Ω4) intensity parameters. From the measured values of emission, cross sections, branching ratios, life times, strong photoluminescence features, and CIE chromaticity coordinates, 0.5 mol% of Eu3+ ions doped ZnNaBiB glasses showed optimum performance and are potential candidate for red light generation at 613 nm.

  12. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Melo, B. M. G.; Graça, M. P. F., E-mail: mpfg@ua.pt; Prezas, P. R.; Valente, M. A. [Physics Department (I3N), Aveiro University, Campus Universitário de Santiago, Aveiro (Portugal); Almeida, A. F.; Freire, F. N. A. [Mechanics Engineering Department, Ceará Federal University, Fortaleza (Brazil); Bih, L. [Equipe Physico-Chimie la Matière Condensée, Faculté des Sciences de Meknès, Meknès (Morocco)

    2016-08-07

    In this work, phosphate-borate based glasses with molar composition 20.7P{sub 2}O{sub 5}–17.2Nb{sub 2}O{sub 5}–13.8WO{sub 3}–34.5A{sub 2}O–13.8B{sub 2}O{sub 3}, 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, σ{sub ac} and σ{sub dc}, 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.

  15. Composition-structure-properties relationship of strontium borate glasses for medical applications.

    Science.gov (United States)

    Hasan, Muhammad S; Werner-Zwanziger, Ulrike; Boyd, Daniel

    2015-07-01

    We have synthesized TiO2 doped strontium borate glasses, 70B2O3-(30-x)SrO-xTiO2 and 70B2 O3 -20SrO(10-x)Na2 O-xTiO2 . The composition dependence of glass structure, density, thermal properties, durability, and cytotoxicity of degradation products was studied. Digesting the glass in mineral acid and detecting the concentrations of various ions using an ICP provided the actual compositions that were 5-8% deviated from the theoretical values. The structure was investigated by means of (11)B magic angle spinning (MAS) NMR spectroscopy. DSC analyses provided the thermal properties and the degradation rates were measured by measuring the weight loss of glass disc-samples in phosphate buffered saline at 37°C in vitro. Finally, the MTT assay was used to analyze the cytotoxicity of the degradation products. The structural analysis revealed that replacing TiO2 for SrO or Na2 O increased the BO3/BO4 ratio suggesting the network-forming role of TiO2 . Thermal properties, density, and degradation rates also followed the structural changes. Varying SrO content predominantly controlled the degradation rates, which in turn controlled the ion release kinetics. A reasonable control (2-25% mass loss in 21 days) over mass loss was achieved in current study. Even though, very high concentrations (up to 5500 ppm B, and 1200 ppm Sr) of ions were released from the ternary glass compositions that saturated the degradation media in 7 days, the degradation products from ternary glass system was found noncytotoxic. However, quaternary glasses demonstrated negative affect on cell viability due to very high (7000 ppm) Na ion concentration. All the glasses investigated in current study are deemed fast degrading with further control over degradation rates, release kinetics desirable.

  16. Absorption and emission properties of Ho{sup 3+} doped lead-zinc-borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Sooraj Hussain, N. [DEMM, Faculty of Eng. University of Porto, Rua Dr. Roberto Frias, 4200-465, Porto (Portugal) and INEB-Instituto de Engenharia Biomedica, Rua Campo Alegre, 823, 4150-180, Porto (Portugal)]. E-mail: sooraj@fe.up.pt; Ali, N. [Department of Mechanical Engineering, University of Aveiro, 3810-193 Aveiro (Portugal); Dias, A.G. [DEMM, Faculty of Eng. University of Porto, Rua Dr. Roberto Frias, 4200-465, Porto (Portugal); INEB-Instituto de Engenharia Biomedica, Rua Campo Alegre, 823, 4150-180, Porto (Portugal); Lopes, M.A. [DEMM, Faculty of Eng. University of Porto, Rua Dr. Roberto Frias, 4200-465, Porto (Portugal); INEB-Instituto de Engenharia Biomedica, Rua Campo Alegre, 823, 4150-180, Porto (Portugal); Santos, J.D. [DEMM, Faculty of Eng. University of Porto, Rua Dr. Roberto Frias, 4200-465, Porto (Portugal); INEB-Instituto de Engenharia Biomedica, Rua Campo Alegre, 823, 4150-180, Porto (Portugal); Buddhudu, S. [Department of Physics, S.V. University, Tirupati, 517502-AP (India)

    2006-09-25

    This paper reports on the affect of lead content on the absorption and emission spectra of the Ho{sup 3+} ion doped lead-zinc-borate glasses in the composition (mol%) of (20 - x)PbO-20ZnO-(59 + x)B{sub 2}O{sub 3}-1.0Ho{sub 2}O{sub 3} where x 0, 5,10,15 of PbO content with {lambda} {sub 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: {delta}E {sup 1} 348.495936 cm{sup -1}, {delta}E {sup 2} = 1.436043 cm{sup -1}, {delta}E {sup 3} = 46.481575 cm{sup -1}, {delta}{xi} {sub 4f} = - 28.512979 cm{sup -1}, {delta}{alpha} = 55.508936 cm{sup -1}, {delta}{beta} = - 1394.339908 cm{sup -1} and {delta}{gamma} 1208.424336 cm{sup -1}. By applying the Judd-Ofelt intensity parameter {omega} {sub 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 {sub T}, {beta}, {tau} {sub r}) characteristic factors of the luminescent transitions ({sup 5}I{sub 8} <- {sup 5}F{sub 3,4,5} and {sup 5}S{sub 2}) of the glasses have been evaluated. Stimulated emission cross-sections ({sigma} {sub p} {sup E}) of the measured emission transitions of holmium glasses have also been computed.

  17. 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.

  18. 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.

  19. Temperature effects on structure and dynamics in borate and borosilicate liquids: High-resolution and high-temperature NMR results

    Energy Technology Data Exchange (ETDEWEB)

    Stebbins, J.F.; Ellsworth, S.E. [Stanford Univ., Stanford, CA (United States)

    1996-09-01

    The fictive temperature dependence of the relative abundances of three- and four-coordinated boron was investigated in several sodium borate and borosilicate glasses using high-resolution {sup 11}B nuclear magnetic resonance (NMR). In the compositions with low sodium/boron ratios, no effect was observed, but in the borosilicates, the fraction of the tetrahedral species decreased significantly as the fictive temperature increased because of the higher content of nonbridging oxygens. In situ, high-temperature magic-angle spinning NMR demonstrated the exchange of the two species at a rate comparable to the shear relaxation rate, indicating a close link between B-O bond breaking and viscous flow.

  20. Optical stability of 3d transition metal ions doped-cadmium borate glasses towards γ-rays interaction

    Science.gov (United States)

    Marzouk, M.; ElBatal, H.; Eisa, W.

    2016-07-01

    This work reports the preparation of glasses of binary cadmium borate with the basic composition (mol% 45 CdO 55 B2O3) and samples of the same composition containing 0.2 wt% dopants of 3d transition metal (TM) oxides (TiO2 → CuO). The glasses have been investigated by combined optical and Fourier Transform infrared spectroscopic measurements before and after being subjected to gamma irradiation with a dose of 8 Mrad (8 × 104 Gy). Optical absorption of the undoped glass before irradiation reveals strong charge transfer UV absorption which is related to the presence of unavoidable contaminated trace iron impurities (mainly Fe3+) within the raw materials used for the preparation of the base cadmium borate glass. The optical spectra of the 3d TM ions exhibit characteristic bands which are related the stable oxidation state of the 3d TM ions within the host glass. Gamma irradiation produces some limited variations in the optical spectra due to the stability of the host glass containing high percent 45 mol% of heavy metal oxide (CdO) which causes some shielding effects towards irradiation. From the absorption edge data, the values of the optical band gap Eopt and Urbach energy (∆E) have been calculated. The values of the optical energy gap are found to be dependent on the glass composition. Infrared absorption spectral measurements reveal characteristic absorption bands due to both triangular and tetrahedral borate groups with the BO3 units vibrations more intense than BO4 units due to the known limit value for the change of BO3 to BO4 groups. The introduction of 3d TM ions with the doping level (0.2 wt%) causes no changes in the number or position of the IR bands because of the presence of TM ions in modifying sites in the glass network. It is observed that gamma irradiation causes some limited changes in the FT-IR spectral bands due to the stability of the host heavy cadmium borate glass.

  1. 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

  2. Dependence of the emission electric dipole line strength of Eu~(3+) on the composition of lead borate glasses

    Institute of Scientific and Technical Information of China (English)

    江莎; 刘子怡; 夹国华; 段昌奎

    2009-01-01

    Lead borate glasses xB2O3+(99-x)PbO+0.5Eu2O3(x=70,60,...,10) were prepared by melt-quenching method.The luminescent properties were characterized with excitation and emission spectra.The emission intensities for 5D0-7FJ(J=0-4) were analyzed to give variation of the relative electric dipole line strengths with the composition of glasses so as to examine the crucial implicit assumption of independent electric dipole line strength on the composition of glass in the Phys.Rev.Lett.2003,91,203903 paper studying l...

  3. Effect of lead oxide on optical properties of Pr{sup 3+} doped some borate based glasses

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, P.; Rai, S.B.; Rai, D.K

    2004-04-14

    The optical properties of Pr{sup 3+} ions in some borate based glasses with varying concentration of lead oxide have been studied. The concentration of lead oxide has been varied from 0 to 50 mol%. The Judd-Ofelt intensity parameters ({omega}{sub {lambda}}) and other radiative properties for the glasses have been calculated. Variations of Judd-Ofelt intensity parameters are discussed on the basis of structural analysis. It is observed from fluorescence spectra that the fluorescence yield increases with addition of lead oxide and is about five times greater at 40% PbO than that at 0% PbO.

  4. 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.

  5. 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.

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

    Science.gov (United States)

    Saleh, H. M.; Tawfik, M. E.; Bayoumi, T. A.

    2011-04-01

    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 °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 137Cs and 60Co 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.

  7. 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.

  8. Inhibition of boric acid and sodium borate on the biological activity of microorganisms in an aerobic biofilter.

    Science.gov (United States)

    Güneş, Y

    2013-01-01

    The aim of this work was to study the inhibition effect of boric acid and sodium borate on the treatment of boron containing synthetic wastewater by a down flow aerobic fixed bed biofilm reactor at various chemical oxygen demand (COD)/boron ratios (0.47-20.54). The inhibitory effect of boron on activated sludge was evaluated on the basis of COD removal during the experimental period. The biofilter (effective volume = 2.5 L) was filled with a ring of plastic material inoculated with acclimated activated sludge. The synthetic wastewater composed of glucose, urea, KH2PO4, MgSO4, Fe2 SO4, ZnSO4 x 7H20, KCl, CaCl2, and di-sodium tetraborate decahydrate or boric acid (B = 100-2000 mg L(-1)). The biological treatment of boron containing wastewater resulted in a low treatment removal rate due to the reduced microbial activity as a result of toxic effects of high boron concentrations. The decrease in the COD removal rate by the presence of either boric acid or sodium borate was practically indistinguishable. It was observed from the experiments that about 90-95% of COD removal was possible at high COD/boron ratios.

  9. High-pressure synthesis and characterization of the first cerium fluoride borate CeB2O4F☆

    Science.gov (United States)

    Hinteregger, Ernst; Wurst, Klaus; Tribus, Martina; Huppertz, Hubert

    2013-01-01

    CeB2O4F is the first cerium fluoride borate, which is exclusively built up of one-dimensional, infinite chains of condensed trigonal-planar [BO3]3− groups. This new cerium fluoride borate was synthesized under high-pressure/high-temperature conditions of 0.9 GPa and 1450 °C in a Walker-type multianvil apparatus. The compound crystallizes in the orthorhombic space group Pbca (No. 61) with eight formula units and the lattice parameters a=821.63(5), b=1257.50(9), c=726.71(6) pm, V=750.84(9) Å3, R1=0.0698, and wR2=0.0682 (all data). The structure exhibits a 9+1 coordinated cerium ion, one three-fold coordinated fluoride ion and a one-dimensional chain of [BO3]3− groups. Furthermore, IR spectroscopy, Electron Micro Probe Analysis and temperature-dependent X-ray powder diffraction measurements were performed. PMID:23935215

  10. High-pressure synthesis and characterization of the first cerium fluoride borate CeB2O4F.

    Science.gov (United States)

    Hinteregger, Ernst; Wurst, Klaus; Tribus, Martina; Huppertz, Hubert

    2013-08-01

    CeB2O4F is the first cerium fluoride borate, which is exclusively built up of one-dimensional, infinite chains of condensed trigonal-planar [BO3](3-) groups. This new cerium fluoride borate was synthesized under high-pressure/high-temperature conditions of 0.9 GPa and 1450 °C in a Walker-type multianvil apparatus. The compound crystallizes in the orthorhombic space group Pbca (No. 61) with eight formula units and the lattice parameters a=821.63(5), b=1257.50(9), c=726.71(6) pm, V=750.84(9) Å(3), R1=0.0698, and wR2=0.0682 (all data). The structure exhibits a 9+1 coordinated cerium ion, one three-fold coordinated fluoride ion and a one-dimensional chain of [BO3](3-) groups. Furthermore, IR spectroscopy, Electron Micro Probe Analysis and temperature-dependent X-ray powder diffraction measurements were performed.

  11. Visible and infrared spectroscopy of Pr{sup 3+} and Tm{sup 3+} ions in lead borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Pisarski, W A [University of Silesia, Institute of Materials Science, Bankowa 12, 40-007, Katowice (Poland); Pisarska, J [Silesian University of Technology, Department of Materials Science, 40-019 Katowice (Poland); Dominiak-Dzik, G [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, 50-422 Wroclaw (Poland); Ryba-Romanowski, W [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, 50-422 Wroclaw (Poland)

    2004-09-01

    The visible luminescence of Pr{sup 3+} and Tm{sup 3+} ions in lead borate glasses has been investigated as a function of activator concentration. The Judd-Ofelt analysis and the Inokuti-Hirayama model for energy transfer between activator ions have been applied for investigations of the radiative and non-radiative relaxation of the Pr and Tm excited states. Based on the luminescence decay curve analysis, the concentration quenching of the {sup 1}D{sub 2} emission of Pr{sup 3+} and {sup 1}G{sub 4} emission of Tm{sup 3+} ions has been attributed to cross-relaxation processes. The infrared spectroscopic measurements provide information on structural changes in the borate network initiated by optically active (Pr or Tm) ions. Contrary to the praseodymium ions, the thulium ions play an additional role as a glass-modifier in the PbO-B{sub 2}O-Al{sub 2}O{sub 3}-WO{sub 3} composition.

  12. Molecular Dynamics Simulation of Lead Borate and Related Glasses in Multicomponent Systems for Low Melting Vitrification of Nuclear Wastes

    Energy Technology Data Exchange (ETDEWEB)

    Kato, S; Benino, Y; Nanba, T [Graduate School of Environmental Science, Okayama University, 3-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530 (Japan); Sakida, S, E-mail: benino@cc.okayama-u.ac.jp [Environmental Management Center, Okayama University, 3-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530 (Japan)

    2011-03-15

    Glasses based on lead oxide have excellent properties in general such as low melting point, high chemical durability and high stability of glassy form, which are suitable for the preservation of volatile nuclear wastes in a permanent vitrified form. In order to confirm the long-term performance of lead borate based glasses it is necessary to establish dissolution and diffusion processes based on a reliable model of the glass structure. In the present study molecular dynamics (MD) simulation of lead borate based glasses was carried out introducing a dummy negative point charge to reproduce asymmetric PbO{sub n} units. Parameters for the dummy charge were optimized based on the comparison between calculated radial distribution function and experimental one. Asymmetric coordination around Pb, for example trigonal bipyramid, was successfully reproduced in the MD simulated binary and ternary glass models. The simple model using the dummy charge was confirmed to be valid for further simulations of multicomponent glasses containing nuclear wastes and heavy elements.

  13. Detecting non-bridging oxygens: non-resonant inelastic X-ray scattering in crystalline lithium borates.

    Science.gov (United States)

    Lelong, Gérald; Radtke, Guillaume; Cormier, Laurent; Bricha, Hanane; Rueff, Jean-Pascal; Ablett, James M; Cabaret, Delphine; Gélébart, Frédéric; Shukla, Abhay

    2014-10-20

    Probing the local environment of low-Z elements, such as oxygen, is of great interest for understanding the atomic-scale behavior in materials, but it requires experimental techniques allowing it to work with versatile sample environments. In this paper, the local environment of lithium borate crystals is investigated using non-resonant inelastic X-ray scattering (NRIXS) at energy losses corresponding to the oxygen K-edge. Large variations of the spectral features are observed close to the edge onset in the 535-540 eV energy range when varying the Li2O content. Calculations allow identification of contributions associated with bridging oxygen (BO) and non-bridging oxygen (NBO) atoms. The main result resides in the observed core-level shift of about 1.7 eV in the spectral signatures of the BO and NBO. The clear signature at 535 eV in the O K-edge NRXIS spectrum is thus an original way to probe the presence of NBOs in borates, with the great advantage of making possible the use of complex environments such as a high-pressure cell or high-temperature device for in situ measurements.

  14. 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.

  15. 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.

  16. 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 in the literat...

  17. High-pressure synthesis and characterization of the first cerium fluoride borate CeB{sub 2}O{sub 4}F

    Energy Technology Data Exchange (ETDEWEB)

    Hinteregger, Ernst; Wurst, Klaus [Institut für Allgemeine, Anorganische und Theoretische Chemie, Leopold-Franzens-Universität Innsbruck, Innrain 80-82, A-6020 Innsbruck (Austria); Tribus, Martina [Institut für Mineralogie und Petrographie, Leopold-Franzens-Universität Innsbruck, Innrain 52 f, A-6020 Innsbruck (Austria); Huppertz, Hubert, E-mail: hubert.huppertz@uibk.ac.at [Institut für Allgemeine, Anorganische und Theoretische Chemie, Leopold-Franzens-Universität Innsbruck, Innrain 80-82, A-6020 Innsbruck (Austria)

    2013-08-15

    CeB{sub 2}O{sub 4}F is the first cerium fluoride borate, which is exclusively built up of one-dimensional, infinite chains of condensed trigonal-planar [BO{sub 3}]{sup 3−} groups. This new cerium fluoride borate was synthesized under high-pressure/high-temperature conditions of 0.9 GPa and 1450 °C in a Walker-type multianvil apparatus. The compound crystallizes in the orthorhombic space group Pbca (No. 61) with eight formula units and the lattice parameters a=821.63(5), b=1257.50(9), c=726.71(6) pm, V=750.84(9) Å{sup 3}, R{sub 1}=0.0698, and wR{sub 2}=0.0682 (all data). The structure exhibits a 9+1 coordinated cerium ion, one three-fold coordinated fluoride ion and a one-dimensional chain of [BO{sub 3}]{sup 3−} groups. Furthermore, IR spectroscopy, Electron Micro Probe Analysis and temperature-dependent X-ray powder diffraction measurements were performed. - Graphical abstract: A new rare-earth fluoride borate CeB{sub 2}O{sub 4}F could be synthesized under high-pressure/high-temperature conditions of 0.9 °GPa and 1450 °Cin a Walker-type multianvil apparatus. The crystal structure represents a new structure type in the class of rare-earth fluoride borates. The structure exhibits a 9+1 coordinated cerium ion, one three-fold coordinated fluoride ion and a one-dimensional chain of [BO{sub 3}]{sup 3−} groups. A closer view on the ac-plane shows an interesting wave-like modulation of the borate chains. Highlights: • CeB{sub 2}O{sub 4}F is the first fluoride borate exclusively built up of one-dimensional, infinite chains of condensed trigonal-planar [BO{sub 3}]{sup 3−} groups. • CeB{sub 2}O{sub 4}F is the first cerium fluoride borate. • High-pressure conditions were necessary to synthesize CeB{sub 2}O{sub 4}F.

  18. 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

  19. Citrus bergamia Risso Elevates Intracellular Ca2+ in Human Vascular Endothelial Cells due to Release of Ca2+ from Primary Intracellular Stores

    Directory of Open Access Journals (Sweden)

    Purum Kang

    2013-01-01

    , which was partially inhibited by a nonselective Ca2+ channel blocker La3+. In Ca2+-free extracellular solutions, BEO increased [Ca2+]i in a concentration-dependent manner, suggesting that BEO mobilizes intracellular Ca2+. BEO-induced [Ca2+]i increase was partially inhibited by a Ca2+-induced Ca2+ release inhibitor dantrolene, a phospholipase C inhibitor U73122, and an inositol 1,4,5-triphosphate (IP3-gated Ca2+ channel blocker, 2-aminoethoxydiphenyl borane (2-APB. BEO also increased [Ca2+]i in the presence of carbonyl cyanide m-chlorophenylhydrazone, an inhibitor of mitochondrial Ca2+ uptake. In addition, store-operated Ca2+ entry (SOC was potentiated by BEO. These results suggest that BEO mobilizes Ca2+ from primary intracellular stores via Ca2+-induced and IP3-mediated Ca2+ release and affect promotion of Ca2+ influx, likely via an SOC mechanism.

  20. 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.

  1. Establishment and identification of a Tet-on HeLa cell model of CX26/CX32 gap junction%CX26/CX32缝隙连接蛋白的Tet-on HeLa细胞模型的建立及鉴定

    Institute of Scientific and Technical Information of China (English)

    杨燕; 吴穷; 郑荣生; 汪子书; 王俊斌; 汪蕊; 陶亮

    2013-01-01

    Objective To establish a specific cell model in vitro for fast and efficient measuring the effect of candidate drug on gap junction (GJ),which may provide an ideal experimental tool for both drug discovery targeting GJ and the specific research for GJ.Methods The bidirectional vector pBI plasmid under the control of a bidirectional doxycycline-inducible promoter was constructed.The Tet-on HeLa cells were transfected with CX26/CX32 cDNA and the cell model stably expressing CX26/CX32 and functional heteromeric GJ channels was established.Cells were cultured in the presence or absence of doxycycline (Dox,1 μg/mL),the expression of CX26 mRNA and protein in Tet-on HeLa cell were assayed by RT-PCR and Western blot,respectively.The GJ function between adjacent HeLa cells was detected by dye transfer assay,and the proliferation of HeLa cells was measured using sulforhodamine B (SRB) assay.Upon the above cell model,the effects of GJ inhibitor,2-aminoethoxydiphenyl borate (2-APB),and activator,retinoid acid (RA),on the function of GJ were also observed.Results HeLa cells expressed no endogenous CX,and the expression of CX26 mRNA and protein in Tet-on HeLa cells was induced by Dox in the culture medium.Formation of functional GJ due to CX induction by Dox was observed as evidenced by the dye transfer assay.2-APB (50 μmol/L) decreased dye spread through GJs composed of CX26/CX32 in HeLa cells with a GJ inhibition rate of 51.3% (P <0.01) ; while RA (10 μmol/L) increased dye spread through GJs between adjacent HeLa cells with a GJ enhancement rate of 60.3% (P < 0.01).Conclusions Tet-on HeLa cell model stably expressing CX26/CX32 induced by Dox is successfully established,providing an useful technology for both the drug discovery targeting GJ and the specific research of GJ modulation by candidate drugs.%目的 体外建立一种特异性快速有效观察药物对细胞缝隙连接(GJ)作用的特异性细胞模型,为发现作用于GJ的药物以及GJ的特异性研

  2. Physical and optical absorption studies of Fe{sup 3+} - ions doped lithium borate glasses containing certain alkaline earths

    Energy Technology Data Exchange (ETDEWEB)

    Bhogi, Ashok [VNR Vignana Jyothi Institute of Engineering and Technology, Hyderabad, Telangana (India); Kumar, R. Vijaya [School of Physics, University of Hyderabad, Hyderabad, Telangana (India); Kistaiah, P., E-mail: pkistaiah@yahoo.com [Department of Physics, Osmania University, Hyderabad, Telangana (India)

    2016-05-23

    Iron ion doped lithium borate glasses with the composition 15RO-25Li{sub 2}O-59B{sub 2}O{sub 3}-1Fe{sub 2}O{sub 3} (where R= Ca, Sr and Ba) have been prepared by the conventional melt quenching technique and characterized to investigate the physical and optical properties using XRD, density, molar volume and UV-Visible spectroscopy. The optical absorption spectra exhibit a band at around 460 nm which is assigned to {sup 6}A{sub 1g}(S) → 4E{sub g} (G) of Fe{sup 3+} ions with distorted octahedral symmetry. From ultraviolet absorption edges, the optical band gap and Urbach energies have been evaluated. The effect of alkaline earths on these properties is discussed.

  3. X-ray diffraction, spectroscopic and thermal studies on a potential semiorganic NLO material: lithium bis- L-malato borate

    Science.gov (United States)

    Dhanuskodi, S.; Vasantha, K.

    2005-06-01

    A semiorganic nonlinear optical material, lithium bis- L-malato borate (LBMB) (molecular formula C 8H 8BLiO 10), has been synthesized, and single crystals grown from an aqueous solution, by the method of slow evaporation at 30 °C. Crystals of size up to 7 mm × 3 mm × 2 mm were harvested and characterized by powder and single crystal X-ray diffraction and Fourier transform infrared techniques to confirm the identity of the compound formed. The TG-DTA results establish the good thermal stability of the material. The UV-Vis-NIR spectral study reveals that the material has a wide transparency window (230-1500 nm) with a lower cutoff at 230 nm. Kurtz powder test with a Nd:YAG laser indicates the production of SHG output.

  4. 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.

  5. Physical and optical absorption studies of Fe3+ - ions doped lithium borate glasses containing certain alkaline earths

    Science.gov (United States)

    Bhogi, Ashok; Kumar, R. Vijaya; Kistaiah, P.

    2016-05-01

    Iron ion doped lithium borate glasses with the composition 15RO-25Li2O-59B2O3-1Fe2O3 (where R= Ca, Sr and Ba) have been prepared by the conventional melt quenching technique and characterized to investigate the physical and optical properties using XRD, density, molar volume and UV-Visible spectroscopy. The optical absorption spectra exhibit a band at around 460 nm which is assigned to 6A1g(S) → 4Eg (G) of Fe3+ ions with distorted octahedral symmetry. From ultraviolet absorption edges, the optical band gap and Urbach energies have been evaluated. The effect of alkaline earths on these properties is discussed.

  6. In Situ Synthesis Aluminum Borate Whiskers Reinforced TiB2 Matrix Composites for Application in Aluminum Reduction Cells

    Science.gov (United States)

    Zhang, Gang; Yang, Jianhong

    2013-11-01

    The TiB2 matrix ceramics reinforced by aluminum borate whiskers (Al18B4O33 w) had been prepared by the pressureless sintering method. The mechanical properties and densification behavior of the TiB2 matrix ceramics were investigated. The results showed that Al18B4O33 w was in situ synthesized by the reaction of boehmite (AlOOH) and TiB2 powders during the sintering process. Increasing the sintering temperature had benefited for densification of the TiB2 matrix ceramics. Al18B4O33 w could increase the flexural strength and Vicker's hardness. It is obtained that the maximum value Vicker's hardness with 1.81 GPa and flexural strength with 82 MPa for samples sintered at 1600°C.

  7. 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.

  8. 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.

  9. Assessment study for multi-barrier system used in radioactive borate waste isolation based on Monte Carlo simulations.

    Science.gov (United States)

    Bayoumi, T A; Reda, S M; Saleh, H M

    2012-01-01

    Radioactive waste generated from the nuclear applications should be properly isolated by a suitable containment system such as, multi-barrier container. The present study aims to evaluate the isolation capacity of a new multi-barrier container made from cement and clay and including borate waste materials. These wastes were spiked by (137)Cs and (60)Co radionuclides to simulate that waste generated from the primary cooling circuit of pressurized water reactors. Leaching of both radionuclides in ground water was followed and calculated during ten years. Monte Carlo (MCNP5) simulations computed the photon flux distribution of the multi-barrier container, including radioactive borate waste of specific activity 11.22KBq/g and 4.18KBq/g for (137)Cs and (60)Co, respectively, at different periods of 0, 15.1, 30.2 and 302 years. The average total flux for 100cm radius of spherical cell was 0.192photon/cm(2) at initial time and 2.73×10(-4)photon/cm(2) after 302 years. Maximum waste activity keeping the surface radiation dose within the permissible level was calculated and found to be 56KBq/g with attenuation factors of 0.73cm(-1) and 0.6cm(-1) for cement and clay, respectively. The average total flux was 1.37×10(-3)photon/cm(2) after 302 years. Monte Carlo simulations revealed that the proposed multi-barrier container is safe enough during transportation, evacuation or rearrangement in the disposal site for more than 300 years. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. 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.

  11. Synthesis and spectral analysis of Sm:BaB{sub 4}O{sub 7} microfibers embedded in borate glass

    Energy Technology Data Exchange (ETDEWEB)

    Dwivedi, Y., E-mail: yashjidwivedi@gmail.com [Instituto de Física de São Carlos, Universidade de São Paulo, CP 369, 13560-970 São Carlos, SP (Brazil); Physics Department, National Institute of Technology Kurukshetra, Kurukshetra, Haryana 136119 (India); Zilio, S.C. [Instituto de Física de São Carlos, Universidade de São Paulo, CP 369, 13560-970 São Carlos, SP (Brazil); Rai, S.B. [Laser and Spectroscopy Laboratory, Physics Department, Banaras Hindu University, Varanasi, UP221005 (India)

    2014-11-15

    The present article reports synthesis and spectroscopic analysis of Sm:BaB{sub 4}O{sub 7} microfibers embedded in borate glass. Structural analysis, using TEM, XRD techniques, revealed the formation of fibre shaped BaB{sub 4}O{sub 7} crystals. A bright red dominated orange–red emission was observed, on 355 nm and 532 nm excitations, in ceramic sample. Higher emission and absorption higher cross-sections were observed in the ceramic sample than its glass counterpart. We have monitored 45% enhancement in emission intensity ratio ({sup 4}G{sub 5/2}→{sup 6}H{sub 9/2}/G{sub 5/2}→{sup 6}H{sub 5/2}) in glass–ceramic sample due to significant increment in electric dipole transition. Time resolved analysis explored a significant alteration in the excited state relaxation process due to annealing. Several radiative parameters like stimulated emission cross-section, branching ratio, quantum efficiency etc. were estimated to explore lasing possibility in glass and ceramic samples. We found that the quantum efficiency increases from 60.4% in glass to 62.7% in Sm:BaB{sub 4}O{sub 7} microfibers embedded in glass. - Highlights: • Synthesis of fibre shaped surface crystallized Sm:BaB{sub 4}O{sub 7} reported in borate glass. • Strong red PL reported at various physical conditions on 532 and 355 nm excitations. • Effect of fibre growth on absorption, PL, decay dynamics was investigated. • J–O model used to calculate branching ratio, radiative lifetime, quantum efficiency. • Stimulated emission cross-section, bandwidth, gain enhances several times in fibres.

  12. Detection and Assay of Vitamin B-2 (Riboflavin) in Alkaline Borate Buffer with UV/Visible Spectrophotometry.

    Science.gov (United States)

    Bartzatt, Ronald; Wol, Tasloach

    2014-01-01

    The detection and assay of vitamin B-2 (riboflavin) was accomplished under aqueous conditions using sodium borate buffering at pH 7.52 conditions. The absorbance spectrum of riboflavin was determined at different pH values utilizing several buffers. The buffer at pH at 7.52 is followed by accurate and sensitive assay of riboflavin by spectrophotometer at 440 nm wavelength. Where indicated an origin solution (stock) was employed by dissolving sufficient vitamin to make a stock solution of 1.403 × 10(-4) molar concentrations. Measurements of various aqueous solutions containing riboflavin were accomplished that included aqueous test samples, vitamin capsules/tablets, and water vitamin mixtures. A standard curve extended from 7.97 × 10(-7) molar to 1.23 × 10(-4) molar (a 154x folds spread in concentration). The equation of the line was y = 12545x (intercept at origin) with Pearson r correlation of 1.000 (R (2) = 1.000). Concentration of riboflavin assayed ranged from 3.00 × 10(-4) gram per liter (0.30 ppm) to 0.0463 gram per liter (46.35 ppm). The B vitamin riboflavin can be assayed by UV/VIS spectrophotometer at 440 nm in aqueous media and using sodium borate buffer at pH 7.52. The assay can reach as low as 0.30 parts per million with high levels of accuracy and sensitivity.

  13. Studies on Effect of Tri(2-hydroxypropyl), Tri(2-hydroxybutyl) and Tri(hydroxythiodiethylene) Borates on Thermal and Heat Properties of Rigid Polyurethane-Polyisocyanurate Foams

    Institute of Scientific and Technical Information of China (English)

    CZUPRYNSKI, Boguslaw; PACIOREK-SADOWSKA, Joanna; LISZKOWSKA, Joanna

    2006-01-01

    Effect of tri(2-hydroxypropyl), tri(2-hydroxybutyl) and tri(hydroxythiodiethylene) borates (BT2HB, BT2HP and BTHET) on the thermal and heat properties of the rigid polyurethane-polyisocyanurate (PUR-PIR) foams was investigated. Increasing amounts of BT2HB and BT2HP in the foam composition, from 0.05 to 0.4 of chemical equivalent, caused increases in the softening point, the temperature of the first mass loss, the extrapolated temperature of the main mass loss foam and temperature of the highest rate of the mass loss. In the case when BTHTE was added to the foam compositions, the lower increase in the mentioned above characteristic temperatures was observed as compared to those of standard foam (without borate added).

  14. Spectroscopy and energy transfer in lead borate glasses doubly doped with Dy3+-Tb3+ and Tb3+-Eu3+ ions

    Science.gov (United States)

    Pisarska, Joanna; Kos, Agnieszka; Pisarski, Wojciech A.

    2014-08-01

    Lead borate glasses doubly doped with Dy3+-Tb3+ and Tb3+-Eu3+ were investigated using optical spectroscopy. Luminescence spectra of rare earths were detected under various excitation wavelengths. The main green emission band due to 5D4 → 7F5 transition of Tb3+ is observed under excitation of Dy3+, whereas the main red emission band related to 5D0 → 7F2 transition of Eu3+ is successfully observed under direct excitation of Tb3+. In both cases, the energy transfer processes from Dy3+ to Tb3+ and from Tb3+ to Eu3+ in lead borate glasses occur through a nonradiative processes with efficiencies up to 16% and 18%, respectively. The presence of energy transfer process was also confirmed by excitation spectra measurements.

  15. Solid Phase Synthesis of Anhydrous Zinc Borate from Zinc and Boron Oxide and Utilization as a Flame Retardant in Dye and Textile

    OpenAIRE

    AYAR, Barış; GÜRÜ, Metin; ÇAKANYILDIRIM, Çetin

    2014-01-01

    Durability of materials to flame and stability at high temperatures are very important in order to increase the field of use. Non-flammability is not the only requirement materials should not have toxic gas products during the burning, also. Anhydrous zinc borate was chosen as flame retardant due to its advantages, such as; light weight, high melting point, low thermal expansion, and intrinsic smoke suppressant and corrosion resistance properties. For the synthesis, metallic zinc and anhydrou...

  16. Occurrence of a new sulphate mineral: Ca7Na3K(SO4)9 in the Emet borate deposits, western Anatolia (Turkey)

    OpenAIRE

    García-Veigas, Francisco Javier; Ortí Cabo, Federico; Rosell, Laura (Rosell i Ortiz); Gündogan, Ibrahim; Helvaci, Cahit

    2010-01-01

    This paper is a preliminary report on the petrographic and geochemical characteristics of a new sulphate mineral associated with lacustrine glauberite layers. This mineral is present in two boreholes recently drilled in the Emet borate district (Mio-cene; western Anatolia , Turkey). The evaporitic succession in these boreholes is mainly formed of a glauber ite-probertiteal-ternation. We suggest the name"emetite", after the town of Emet, for the new sulphate mineral, although the fine crystal ...

  17. 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. Copyright © 2010 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  18. Silica-Based and Borate-Based, Titania-Containing Bioactive Coatings Characterization: Critical Strain Energy Release Rate, Residual Stresses, Hardness, and Thermal Expansion.

    Science.gov (United States)

    Rodriguez, Omar; Matinmanesh, Ali; Phull, Sunjeev; Schemitsch, Emil H; Zalzal, Paul; Clarkin, Owen M; Papini, Marcello; Towler, Mark R

    2016-12-01

    Silica-based and borate-based glass series, with increasing amounts of TiO₂ incorporated, are characterized in terms of their mechanical properties relevant to their use as metallic coating materials. It is observed that borate-based glasses exhibit CTE (Coefficient of Thermal Expansion) closer to the substrate's (Ti6Al4V) CTE, translating into higher mode I critical strain energy release rates of glasses and compressive residual stresses and strains at the coating/substrate interface, outperforming the silica-based glasses counterparts. An increase in the content of TiO₂ in the glasses results in an increase in the mode I critical strain energy release rate for both the bulk glass and for the coating/substrate system, proving that the addition of TiO₂ to the glass structure enhances its toughness, while decreasing its bulk hardness. Borate-based glass BRT3, with 15 mol % TiO₂ incorporated, exhibits superior properties overall compared to the other proposed glasses in this work, as well as 45S5 Bioglass(®) and Pyrex.

  19. Determination of major, minor and trace elements in rock samples by laser ablation inductively coupled plasma mass spectrometry: Progress in the utilization of borate glasses as targets

    Science.gov (United States)

    Leite, Tácito Dantas F.; Escalfoni, Rainério, Jr.; da Fonseca, Teresa Cristina O.; Miekeley, Norbert

    2011-05-01

    The present work is a continuation of a research study performed at our laboratory aiming at the multielement analysis of rock samples (basalts and shale) by inductively coupled plasma mass spectrometry in combination with laser ablation using borate glasses as analytical targets. Argon, nitrogen-argon mixtures and helium were evaluated as cell gases, the latter confirming its better performance. Different operational parameters of the laser, such as gas flow, energy, focus, scanning speed and sampling frequency were optimized. External calibration was made with standards prepared by fusion of geological reference materials (basalts 688 and BCR-2, obsidian SRM 278, and shale SGR-1) of different mass fractions in the meta-tetra borate matrix. Coefficients of determination ( R2) were > 0.99 for 30 elements from o total of 40 determined. Method validation was then performed using additional certified reference materials (BHVO-2, BIR-1, SCo-1) produced as borate targets in a similar way. Accuracies were better than 10% for most of the elements studied and analytical precisions, calculated from the residual standard deviations of calibration curves were, typically, between 6% and 10%. Additionally, the semiquantitative TotalQuant® technique was applied, which gave, within the expected uncertainty for this calibration technique, concordant results when compared to the quantitative external calibration procedure. Both methods were then used for the analysis of marine shale samples, which are of great geological interest in petroleum prospecting.

  20. 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.

  1. Determination of major, minor and trace elements in rock samples by laser ablation inductively coupled plasma mass spectrometry: Progress in the utilization of borate glasses as targets

    Energy Technology Data Exchange (ETDEWEB)

    Leite, Tacito Dantas F. [Departmento de Quimica da Pontificia Universidade Catolica do Rio de Janeiro, Rua Marques de Sao Vicente 225, 22451-900 Rio de Janeiro (Brazil); Universidade Estadual de Goias (UEG) (Brazil); Instituto Federal de Educacao, Ciencia e Tecnologia de Brasilia (IFB) (Brazil); Escalfoni, Rainerio [Departmento de Quimica da Pontificia Universidade Catolica do Rio de Janeiro, Rua Marques de Sao Vicente 225, 22451-900 Rio de Janeiro (Brazil); Centro de Pesquisas Leopoldo A. Miguez de Mello da Petrobras (CENPES) (Brazil); Fonseca, Teresa Cristina O. da [Centro de Pesquisas Leopoldo A. Miguez de Mello da Petrobras (CENPES) (Brazil); Miekeley, Norbert, E-mail: miekeley@puc-rio.br [Departmento de Quimica da Pontificia Universidade Catolica do Rio de Janeiro, Rua Marques de Sao Vicente 225, 22451-900 Rio de Janeiro (Brazil)

    2011-05-15

    The present work is a continuation of a research study performed at our laboratory aiming at the multielement analysis of rock samples (basalts and shale) by inductively coupled plasma mass spectrometry in combination with laser ablation using borate glasses as analytical targets. Argon, nitrogen-argon mixtures and helium were evaluated as cell gases, the latter confirming its better performance. Different operational parameters of the laser, such as gas flow, energy, focus, scanning speed and sampling frequency were optimized. External calibration was made with standards prepared by fusion of geological reference materials (basalts 688 and BCR-2, obsidian SRM 278, and shale SGR-1) of different mass fractions in the meta-tetra borate matrix. Coefficients of determination (R{sup 2}) were > 0.99 for 30 elements from o total of 40 determined. Method validation was then performed using additional certified reference materials (BHVO-2, BIR-1, SCo-1) produced as borate targets in a similar way. Accuracies were better than 10% for most of the elements studied and analytical precisions, calculated from the residual standard deviations of calibration curves were, typically, between 6% and 10%. Additionally, the semiquantitative TotalQuant (registered) technique was applied, which gave, within the expected uncertainty for this calibration technique, concordant results when compared to the quantitative external calibration procedure. Both methods were then used for the analysis of marine shale samples, which are of great geological interest in petroleum prospecting.

  2. 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

  3. 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.

  4. Prediction for pitting corrosion of AISI type 403 stainless steel in chloride-containing borate buffer solution

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Yancheng [Pennsylvania State Univ. (United States); Macdonald, D.D. [Pennsylvania State Univ. (United States). Center for Electrochemical Science and Technology; Urquidi-Macdonald, M. [Pennsylvania State Univ. (United States). Engineering Science and Mechanics; Engelhardt, G.R. [OLI Systems, Inc. (United States); Dooley, R.B. [Electric Power Research Inst., Palo Alto, CA (United States). Materials and Chemistry Performance Dept.

    2007-07-15

    The prediction of pitting corrosion damage on low-pressure steam turbine (LPST) blade surfaces has been investigated experimentally and the results have been interpreted in terms of the Point Defect Model (PDM) for passivity breakdown and the nucleation of pits. Experimental relationships between the critical breakdown potential (Vc) and the chloride activity aCl- and pH have demonstrated the applicability of the PDM for describing passivity breakdown on AISI Type 403 stainless steel (SS), a commonly employed blade alloy in LPSTs, in chloride-containing borate buffer solutions. The model parameter values, as determined by optimization of the PDM on passivity breakdown data, may be used to predict the nucleation and accumulation of pitting damage on LPST blades under simulated turbine shutdown conditions. In order to evaluate the predictions, integral damage functions (IDFs) and extreme value distributions in pit depth have been measured on samples taken from failed blades recovered from the field (Texas Genco). These data are being used to test the predictions of Damage Function Analysis (DFA), which is based on the PDM and on deterministic models for pit growth and delayed repassivation. However, the success of this analysis critically depends on our ability to define the corrosion evolutionary path. (orig.)

  5. Physical, thermal, structural and optical absorption studies of vanadyl doped magnesium oxy-chloride bismo-borate glasses

    Directory of Open Access Journals (Sweden)

    M.S. Dahiya

    2015-06-01

    Full Text Available Oxy-chloride bismuth-borate glasses with composition xMgCl2·(30 − xMgO·20Bi2O3·50B2O3 containing 2 mol% doping of V2O5 (x = 12, 15, 20, 25 and 30 are prepared by melt-quenching technique. The structural, thermal and optical behaviors are explained by analyzing the data obtained from density (D, molar volume (Vm, theoretical optical basicity (Λth, differential scanning calorimetry (DSC, FTIR and UV–vis results. A decrease in D and increase in Vm (except for sample MBV3 for which D is maximum on increasing chloride content suggests the formation of non-bridging oxygen atoms. Maximum glass transition temperature (Tg and crystallization temperature (Tx have been observed for sample MBV3. The glass stability (S and stability ratio (S/Tg have been calculated from the values of Tg and Tx and both are having maximum values for sample MBV3. Study of the FTIR spectra in the mid-IR range reveals the presence of both triangular and tetrahedral coordinated boron. The optical studies through UV–vis spectral analysis show non-sharp edge. The optical band gap (Eg is also maximum for sample MBV3.

  6. High Boron-induced Ubiquitination Regulates Vacuolar Sorting of the BOR1 Borate Transporter in Arabidopsis thaliana*

    Science.gov (United States)

    Kasai, Koji; Takano, Junpei; Miwa, Kyoko; Toyoda, Atsushi; Fujiwara, Toru

    2011-01-01

    Boron homeostasis is important for plants, as boron is essential but is toxic in excess. Under high boron conditions, the Arabidopsis thaliana borate transporter BOR1 is trafficked from the plasma membrane (PM) to the vacuole via the endocytic pathway for degradation to avoid excess boron transport. Here, we show that boron-induced ubiquitination is required for vacuolar sorting of BOR1. We found that a substitution of lysine 590 with alanine (K590A) in BOR1 blocked degradation. BOR1 was mono- or diubiquitinated within several minutes after applying a high concentration of boron, whereas the K590A mutant was not. The K590A mutation abolished vacuolar transport of BOR1 but did not apparently affect polar localization to the inner PM domains. Furthermore, brefeldin A and wortmannin treatment suggested that Lys-590 is required for BOR1 translocation from an early endosomal compartment to multivesicular bodies. Our results show that boron-induced ubiquitination of BOR1 is not required for endocytosis from the PM but is crucial for the sorting of internalized BOR1 to multivesicular bodies for subsequent degradation in vacuoles. PMID:21148314

  7. Redox-active nickel and cobalt tris(pyrazolyl)borate dithiocarbamate complexes: air-stable Co(II) dithiocarbamates.

    Science.gov (United States)

    Harding, David J; Harding, Phimphaka; Dokmaisrijan, Supaporn; Adams, Harry

    2011-02-14

    A series of new cobalt(II) and nickel(II) tris(3,5-diphenylpyrazolyl)borate (Tp(Ph2)) dithiocarbamate complexes [Tp(Ph2)M(dtc)] (M = Co, dtc = S₂CNEt₂ 1, S₂CNBz₂ 2 and S₂CN(CH₂)₄ 3; M = Ni, dtc = S₂CNEt₂ 4, S₂CNBz₂ 5 and S₂CN(CH₂)₄ 6) have been prepared by the reaction of [Tp(Ph2)MBr] with Nadtc in CH₂Cl₂. IR spectroscopy indicates that the Tp(Ph2) ligand is κ³ coordinated while the dithiocarbamate ligand is κ² coordinated. ¹H NMR and UV-Vis spectroscopy are consistent with high spin, five-coordinate metal centres. X-ray crystallographic studies of 1, 3 and 6 confirm the κ³ coordination of the Tp(Ph2) ligand and reveal an intermediate five-coordinate geometry with an asymmetrically coordinated dithiocarbamate ligand. Electrochemical studies of 1-6 reveal a metal centred reversible one-electron oxidation to M(III). Attempted oxidation of [Tp(Ph2)Co(dtc)] with [FeCpCp(COMe)]BF₄ yields [Co(dtc)₃], Hpz(Ph2) and a further product which may be [Tp(Ph2)CoBp(Ph2)]. DFT calculations indicate that the low redox potentials in these complexes result from a strongly antibonding M-S σ* HOMO.

  8. Growth and characterization studies of sodium Di(L-Malato) borate bulk single crystal: A promising nonlinear optical material

    Science.gov (United States)

    Senthil, A.; Loganayaki, M.; Lenin, M.; Ramasamy, P.

    2012-06-01

    A semi-organic nonlinear optical material, sodium di(L-malato) borate (NaDMB) has been synthesized. Optically good quality bulk single crystal of NaDMB was successfully grown by slow evaporation solution technique (SEST) and Sankaranarayanan-Ramasamy (SR) method at 36 °C. Transparent, colourless crystal of size 22 mm X 8 mm X 6 mm with well defined morphology was grown by SEST and oriented unidirectional bulk single crystal of size 48 mm length and 16 mm diameter was grown by SR method. The grown crystals were subjected to single crystal X-ray diffraction studies. The crystal belongs to monoclinic structure with space group P21. The grown crystals were characterized by UV-vis studies. The structural perfection of the grown crystal has been analyzed by high-resolution X-ray diffraction (HRXRD) rocking curve measurements. The differential thermal (DTA) and thermogravimetric (TG) analysis traces reveal the thermal stability of the sample. The second-harmonic generation efficiency was estimated by Kurtz and Perry powder technique.

  9. Incorporation of Boron Atoms on Graphene Grown by Chemical Vapor Deposition Using Triisopropyl Borate as a Single Precursor

    Directory of Open Access Journals (Sweden)

    E. C. Romani

    2017-01-01

    Full Text Available We synthesized single-layer graphene from a liquid precursor (triisopropyl borate using a chemical vapor deposition. Optical microscopy, scanning electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy measurements were used for the characterization of the samples. We investigated the effects of the processing temperature and time, as well as the vapor pressure of the precursor. The B1s core-level XPS spectra revealed the presence of boron atoms incorporated into substitutional sites. This result, corroborated by the observed upshift of both G and 2D bands in the Raman spectra, suggests the p-doping of single-layer graphene for the samples prepared at 1000°C and pressures in the range of 75 to 25 mTorr of the precursor vapor. Our results show that, in optimum conditions for single-layer graphene growth, that is, 1000°C and 75 mTorr for 5 minutes, we obtained samples presenting the coexistence of pristine graphene with regions of boron-doped graphene.

  10. [Effect of amount of silane coupling agent on flexural strength of dental composite resins reinforced with aluminium borate whisker].

    Science.gov (United States)

    Zhu, Ming-yi; Zhang, Xiu-yin

    2015-06-01

    To evaluate the effect of amount of silane coupling agent on flexural strength of dental composite resins reinforced with aluminium borate whisker (ABW). ABW was surface-treated with 0%, 1%, 2%, 3% and 4% silan coupling agent (γ-MPS), and mixed with resin matrix to synthesize 5 groups of composite resins. After heat-cured at 120 degrees centigrade for 1 h, specimens were tested in three-point flexure to measure strength according to ISO-4049. One specimen was selected randomly from each group and observed under scanning electron microscope (SEM). The data was analyzed with SAS 9.2 software package. The flexural strength (117.93±11.9 Mpa) of the group treated with 2% silane coupling agent was the highest, and significantly different from that of the other 4 groups (α=0.01). The amount of silane coupling agent has impact on the flexural strength of dental composite resins reinforced with whiskers; The flexual strength will be reduced whenever the amount is higher or lower than the threshold. Supported by Research Fund of Science and Technology Committee of Shanghai Municipality (08DZ2271100).

  11. 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.

  12. 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.

  13. 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.

  14. 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

    2016-01-05

    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. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. 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.

  16. 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).

  17. Effect of Bi2O3 on spectroscopic and structural properties of Er3+ doped cadmium bismuth borate glasses.

    Science.gov (United States)

    Sanghi, S; Pal, I; Agarwal, A; Aggarwal, M P

    2011-12-01

    Glasses with composition 20CdO·xBi(2)O(3)·(79.5-x)B(2)O(3) (15≤x≤35, x in mol%) containing 0.5 mol% of Er(3+) ions were prepared by melt-quench technique (1150°C in air). The amorphous nature of the glasses was confirmed by X-ray diffraction. The spectroscopic properties of the glasses were investigated using optical absorption spectra and fluorescence spectra. The phenomenological Judd-Ofelt intensity parameters Ω(λ) (λ=2, 4, 6) were determined from the spectral intensities of absorption bands in order to calculate the radiative transition probability (A(R)), radiative life time (τ(R)), branching ratios (β(R)) for various excited luminescent states. Using the near infrared emission spectra, full width at half maxima (FWHM), stimulated emission cross-section (σ(e)) and figure of merit (FOM) were evaluated and compared with other hosts. Especially, the numerical values of these parameters indicate that the emission transition (4)I(13/2)→(4)I(15/2) at 1.506 μm in Er(3+)-doped cadmium bismuth borate glasses may be useful in optical communication.

  18. Dosimetric properties of germanium doped calcium borate glass subjected to 6 MV and 10 MV X-ray irradiations

    Energy Technology Data Exchange (ETDEWEB)

    Tengku Kamarul Bahri, T.N.H., E-mail: tnhidayah2@gmail.com [Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru (Malaysia); Wagiran, H.; Hussin, R.; Saeed, M.A. [Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru (Malaysia); Hossain, I. [Department of Physics, College of Science and Arts, King Abdul Aziz University, 21911 Rabigh (Saudi Arabia); Ali, H. [Department of Radiotherapy and Oncology, Hospital Sultan Ismail, 81100 Johor Bahru (Malaysia)

    2014-10-01

    Highlights: •The TL properties of 29.9CaO–70B{sub 2}O{sub 3}: 0.1GeO{sub 2} glass has been investigated. •We exposed glass samples to 6 MV and 10 MV in a dose range of 0.5–4.0 Gy. •This glass has a potential material to be used for application in radiotherapy. -- Abstract: Germanium doped calcium borate glasses are investigated in term of thermoluminescence properties to seek their possibility to use as glass radiation dosimeter. The samples were exposed to 6 MV, and 10 MV photon beams in a dose range of 0.5–4.0 Gy. There is a single and broad thermoluminescence glow curve that exhibits its maximum intensity at about 300 °C. Linear dose response behavior has been found in this dose range for the both photon energies. Effective atomic number, TL sensitivity, and reproducibility have also been studied. It is found that the sensitivity of germanium doped sample at 6 MV is only 1.28% and it is superior to the sensitivity at 10 MV. The reproducibility of germanium doped sample is good with a percentage of relative error less than 10%. The results indicate that this glass has a potential to be used as a radiation dosimetry, especially for application in radiotherapy.

  19. 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.

  20. Optical absorption and fluorescence properties of Er{sup 3+}/Yb{sup 3+} codoped lead bismuth alumina borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Goud, K. Krishna Murthy, E-mail: krishnamurthy.phy@gmail.com; Reddy, M. Chandra Shekhar, E-mail: krishnamurthy.phy@gmail.com; Rao, B. Appa, E-mail: krishnamurthy.phy@gmail.com [Dept. of Physics, Osmania University, Hyderabad-500007, Andhra Pradesh (India)

    2014-04-24

    Lead bismuth alumina borate glasses codoped with Er{sup 3+}/Yb{sup 3+} were prepared by melt quenching technique. Optical absorption, FTIR and photoluminescence spectra of these glasses have been studied. Judd-Ofelt theory has been applied to to the f ↔ f transitions for evaluating Ω{sub 2}, Ω{sub 4} and Ω{sub 6} parameters. Radiative properties like branching ratio β{sub r} and the radiative life time τ{sub R} have been determined on the basis of Judd-Ofelt theory. Upconversion emissions have been observed under 980nm laser excitation at room temperature. Green and red up-conversion emissions are centered at 530, 550 and 656 nm corresponding to {sup 2}H{sub 11/2}→{sup 4}I{sub 15/2}, {sup 4}S{sub 3/2}→{sup 4}I{sub 15/2} and {sup 4}F{sub 9/2}→{sup 4}I{sub 15/2} transitions of Er{sup 3+} respectively. The results obtained are discussed quantitatively based on the energy transfer between Yb{sup 3+} and Er{sup 3+}.

  1. 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.

  2. Spectroscopic investigations on Pr³+ and Nd³+ doped strontium-lithium-bismuth borate glasses.

    Science.gov (United States)

    Rajesh, D; Balakrishna, A; Seshadri, M; Ratnakaram, Y C

    2012-11-01

    Spectroscopic investigations on different concentrations (0.1, 0.5, 1.0, 1.5 and 2.0mol%) of Pr(3+) and Nd(3+) doped strontium lithium bismuth borate glasses have been done. X-ray diffraction, SEM with EDS, absorption and luminescence spectra were recorded for all the glass matrices and analyzed. X-ray diffraction profiles and SEM images conformed amorphous nature of investigated glass samples. EDS spectra of host glass and Pr(3+)doped glass matrices gave information about the chemical composition of glass samples. From the absorption spectra of Pr(3+) and Nd(3+) ions, Judd-Ofelt (J-O) intensity parameters (Ω(λ),λ=2, 4 and 6) have been calculated and compared with other glass matrices. The emission characteristics such as radiative lifetimes (τ(R)), measured and calculated branching ratios (β) and stimulated emission cross-sections (σ(P)) have been obtained for the observed emission transitions of Pr(3+) and Nd(3+) ions in the above glass matrix for all the concentrations. From the emission spectra of Pr(3+) and Nd(3+) doped glass matrices, the effect of concentration on the quenching of intensity of (1)D(2)→(3)H(4) transition of Pr(3+) ion and (4)F(3/2)→(4)I(9/2), (4)I(11/2) and (4)I(13/2) transitions of Nd(3+) have been studied and discussed.

  3. Controlled preparation of aluminum borate powders for the development of defect-related phosphors for warm white LED lighting

    Science.gov (United States)

    Guimarães, Vinicius F.; Salaün, Mathieu; Burner, Pauline; Maia, Lauro J. Q.; Ferrier, Alban; Viana, Bruno; Gautier-Luneau, Isabelle; Ibanez, Alain

    2017-03-01

    The optimization of the elaboration conditions of a new family of highly emissive white phosphors based on glassy yttrium aluminum borates (g-YAB) compositions is presented. Their preparation from solutions is based on the polymeric precursor method (modified Pechini process), involving non-toxic and low cost precursors. The resulting resins were first dried at moderate temperatures followed by two-step annealing treatments of the obtain powders under controlled atmospheres: a first pyrolysis under nitrogen followed by a calcination under oxygen. This favored the gradual oxidation of organic moieties coming from starting materials, avoiding uncontrolled self-combustion reactions, which generate localized hot spots. This prevented phase segregations and the formation of pyrolytic carbon or carbonates, which are strongly detrimental to the luminescence properties. Thus, coupled chemical analyses and luminescence characterizations showed the high chemical homogeneity of the resulting powders and their intense emissions in the whole visible range. These emissions can be tuned from blue to warm white by adjusting the calcination temperature that is an important advantage for the development of LED devices. We showed that impurities of monovalent and divalent cations act as quenching emission centers for these phosphors. Therefore, by increasing the purity grade, we significantly enhanced the PL emissions leading to high internal quantum yields (80-90%). Finally, cathodoluminescence emissions showed the homogeneous dispersion of emitting centers in the g-YAB matrix.

  4. Synthesis of new type titanium borate from borax and titanyl sulfate%由硼砂和硫酸氧钛合成新型硼酸钛

    Institute of Scientific and Technical Information of China (English)

    王珊珊; 仲剑初; 王洪志

    2013-01-01

    A new type of titanium borate was synthesized by wet chemistry method with titanyl sulfate and borax as raw materials.The effects of reactant mix ratio,reactant concentration,and reaction time etc.on the synthesis of titanium borate were investigated.The suitable synthetic conditions of titanium borate were obtained,i.e.room temperature,borax solution concentration of 1 mol/L,titanyl sulfate concentration of 0.9 mol/L,n (Ti):n (B) =1:5,and time of 15~20 min.The contents of B2O3,TiO2,and H2O of the product were determined through chemical analysis,ICP,and TG/DTG,respectively.IR,and Raman spectra of the product showed the BO33-existed in the form of(B2O5)4-group.The molecular formula of titanium borate (TiO)2B2O5 ·4H2O was confirmed by calculation.The purity of titanium borate was 82%.The product was characterized by XRD and SEM,and results showed that titanium borate was block-like amorphous particles with a particle size at 1~10 μm.%以硫酸氧钛和硼砂为原料采用湿化学法合成一种新型硼酸钛,考察了反应物配比、反应物浓度和反应时间等因素对硼酸钛合成的影响.适宜的合成条件:室温,硼砂溶液浓度为1 mol/L,硫酸氧钛溶液浓度为0.9 mol/L,钛与硼物质的量比为1∶5,反应时间为15~20 min.通过化学分析、电感耦合等离子发射光谱(ICP)以及热重分析(TG-DTG)等表征手段确定硼酸钛中氧化硼、二氧化钛和水的含量;产物的红外(IR)和拉曼(Raman)光谱分析表明硼酸根以(B2O5)4-基团形式存在;经计算得出硼酸钛分子式为(TiO)2B2O5· 4H2O,纯度为82%.对硼酸钛进行了X射线衍射(XRD)、扫描电镜(SEM)表征,表明合成的硼酸钛为颗粒尺寸在1~10 μm的块状非晶态粉体.

  5. 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

  6. Crystal structure of a new polar borate Na2Ce2[BO2(OH)][BO3]2 · H2O with isolated boron triangles

    Science.gov (United States)

    Topnikova, A. P.; Belokoneva, E. L.; Dimitrova, O. V.; Volkov, A. S.

    2016-11-01

    Crystals of a new polar borate Na2Ce2[BO2(OH)][BO3]2 · H2O were prepared by hydrothermal synthesis. The crystals are orthorhombic, a = 7.2295(7) Å, b = 11.2523(8) Å, c = 5.1285(6) Å, Z = 2, sp. gr. C2 mm ( Amm2), R = 0.0253. The formula of the compound was derived from the structure determination. The Ce and Na atoms are coordinated by nine and six O atoms, respectively. The Ce position is split, and a small amount of Ce is incorporated into the Na1 site with the isomorphous substitution for Na. The anionic moieties exist as isolated BO3 and BO2(OH) triangles. The planes of the BO2(OH) triangles with mm2 symmetry are parallel to the ab plane. The planes of the BO3 triangles with m symmetry are perpendicular to the ab plane and are rotated in a diagonal way. The splitting of the Ce positions and the polar arrangement of the BO2(OH) triangles, water molecules, and Na atoms are observed along the polar a axis. The new structure is most similar to the new borate NaCa4[BO3]3 (sp. gr. Ama2), in which triangles of one type are arranged in a polar fashion along the c axis. Weak nonlinear-optical properties of both polar borates are attributed to the quenching of the second-harmonic generation due to the mutually opposite orientation of two-thirds of B triangles in the unit cell.

  7. Kinetics and mechanisms of the conversion of silicate (45S5), borate, and borosilicate glasses to hydroxyapatite in dilute phosphate solutions.

    Science.gov (United States)

    Huang, Wenhai; Day, Delbert E; Kittiratanapiboon, Kanisa; Rahaman, Mohamed N

    2006-07-01

    Bioactive glasses with controllable conversion rates to hydroxyapatite (HA) may provide a novel class of scaffold materials for bone tissue engineering. The objective of the present work was to comprehensively characterize the conversion of a silicate bioactive glass (45S5), a borate glass, and two intermediate borosilicate glass compositions to HA in a dilute phosphate solution at 37 degrees Celsius. The borate glass and the borosilicate glasses were derived from the 45S5 glass by fully or partially replacing the SiO(2) with B(2)O(3). Higher B(2)O(3) content produced a more rapid conversion of the glass to HA and a lower pH value of the phosphate solution. Whereas the borate glass was fully converted to HA in less than 4 days, the silicate (45S5) and borosilicate compositions were only partially converted even after 70 days, and contained residual SiO(2) in a Na-depleted core. The concentration of Na(+) in the phosphate solution increased with reaction time whereas the PO(4) (3-) concentration decreased, both reaching final limiting values at a rate that increased with the B(2)O(3) content of the glass. However, the Ca(2+) concentration in the solution remained low, below the detection limit of atomic absorption, throughout the reaction. Immersion of the glasses in a mixed solution of K(2)HPO(4) and K(2)CO(3) produced a carbonate-substituted HA but the presence of the K(2)CO(3) had little effect on the kinetics of conversion to HA. The kinetics and mechanisms of the conversion process of the four glasses to HA are compared and used to develop a model for the process.

  8. 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.

  9. A density functional theory study of the carbon-coating effects on lithium iron borate battery electrodes.

    Science.gov (United States)

    Loftager, Simon; García-Lastra, Juan María; Vegge, Tejs

    2017-01-18

    Lithium iron borate (LiFeBO3) is a promising cathode material due to its high theoretical specific capacity, inexpensive components and small volume change during operation. Yet, challenges related to severe air- and moisture-induced degradation have prompted the utilization of a protective coating on the electrode which also improves the electronic conductivity. However, not much is known about the preferential geometries of the coating as well as how these coating-electrode interfaces influence the lithium diffusion between the coating and the electrode. Here, we therefore present a density functional theory (DFT) study of the anchoring configurations of carbon coating on the LiFeBO3 electrode and its implications on the interfacial lithium diffusion. Due to large barriers associated with Li-ion diffusion through a parallel-oriented pristine graphene coating on the FeBO3 and LiFeBO3 electrode surfaces, large structural defects in the graphene coating are required for fast Li-ion diffusion. However, such defects are expected to exist only in small concentrations due to their high formation energies. Alternative coating geometries were therefore investigated, and the configuration in which the coating layers were anchored normal to the electrode surface at B and O atoms was found to be most stable. Nudged elastic band (NEB) calculations of the lithium diffusion barriers across the interface between the optimally oriented coating layers and the electrode show no kinetic limitations for lithium extraction and insertion. Additionally, this graphite-coating configuration showed partial blocking of electrode-degrading species.

  10. Structure and optical properties of a new borate K2Ba4Ga4Li2B6O21

    Science.gov (United States)

    Gao, X.; Li, R. K.

    2014-10-01

    A new borate crystal, K2Ba4Ga4Li2B6O21, was successfully synthesized and grown by the spontaneous crystallization with K2O-B2O3-LiF flux. It belongs to a hexagonal space group P 6 bar 2c with cell parameters of a = 8.6544(4) Å, c = 16.9226(16) Å, and Z = 2. The fundamental building units in the structure are the planar BO3 triangle, tetrahedral GaO4 and LiO4 anionic groups. These anions jointed together by corner-sharing O atoms to form a ∞2[Ga2Li(BO3)3 ]2- layer. The neighboring layers are linked with apical O atoms of GaO4 and LiO4 groups in the c direction to build up a three-dimensional framework. The structure is closely related to that of the nonlinear optical crystal K2Al2B2O7 with two Ga and one Li atoms occupying the three Al sites and simultaneously a mixed K+/Ba2+ and a pure Ba2+ cation replacing the two K sites in an ordered fashion. Second-harmonic generation (SHG) test indicates that the SHG signal of K2Ba4Ga4Li2B6O21 crystal is about half as large as that of KDP standard. The UV-Vis-NIR diffuse reflectance spectra shows that the crystal has a high transmission ranging from 400 nm to 1200 nm with a UV cut-off edge at 226 nm.

  11. 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.

  12. Spectroscopic studies of Sm3+ ions activated lithium lead alumino borate glasses for visible luminescent device applications

    Science.gov (United States)

    Deopa, Nisha; Rao, A. S.

    2017-10-01

    Photoluminescence (PL) characterization of Lithium Lead Alumino Borate (LiPbAlB) glasses doped with Sm3+ ions at varying concentrations have been studied by using absorption, excitation, emission, time resolved and confocal image measurements. From the absorption spectra, Judd-Ofelt (J-O) intensity parameters were evaluated and in turn used to estimate various radiative parameters for the fluorescent levels of Sm3+ ion doped LiPbAlB glasses. The PL spectra of Sm3+ ions exhibit three emission bands corresponding to the transitions 4G5/2 → 6H5/2, 6H7/2 and 6H9/2, for which the emission cross-sections and branching ratios were evaluated to know the potentialities of these materials as visible luminescent devices. The decay spectral profiles measured for 4G5/2 → 6H7/2 transition level were used to estimate quantum efficiency of the as-prepared glasses. The non-exponential decay curves observed for higher Sm3+ ion concentrations were well fitted to Inokuti-Hirayama model to understand the predominant energy transfer mechanism involved in the as-prepared glasses. CIE chromaticity coordinates and correlated color temperatures (CCT) were evaluated to understand the utility of the titled glasses in cool white light generation. The confocal images captured under 405 nm CW laser excitation show intense reddish-orange color. From the evaluated radiative parameters, emission cross-sections, quantum efficiency, CIE co-ordinates, CCT temperatures and confocal images, it was observed that LiPbAlB glass with 0.5 mol% Sm3+ ions are more suitable for w-LEDs and reddish-orange luminescent device applications.

  13. Multimodal emissions from Tb3+/Yb3+ co-doped lithium borate glass: Upconversion, downshifting and quantum cutting

    Science.gov (United States)

    Bahadur, A.; Yadav, R. S.; Yadav, R. V.; Rai, S. B.

    2017-02-01

    This paper reports the optical properties of Tb3+/Yb3+ co-doped lithium borate (LB) glass prepared by melt quench method. The absorption spectrum of the Yb3+ doped LB glass contains intense NIR band centered at 976 nm due to 2F7/2→2F5/2 transition. The emission spectra of the prepared glasses have been monitored on excitation with 266, 355 and 976 nm. The Yb3+ doped glass emits a broad NIR band centered at 976 nm whereas the Tb3+ doped glass gives off visible bands on excitations with 266 and 355 nm. When the Tb3+ and Yb3+ ions are co-doped together, the emission intensity in the visible region decreases whereas it increases in the NIR region significantly. The increase in the emission intensity in the NIR region is due to efficient cooperative energy transfer (CET) from Tb3+ to Yb3+ ions. The quantum cutting efficiency for Tb3+/Yb3+ co-doped glass has been calculated and compared for 266 and 355 nm excitations. The quantum cutting efficiency is larger for 355 nm excitation (137%). The Tb3+/Yb3+ co-doped LB glass also emits upconverted visible bands on excitation with 976 nm. The mechanisms involved in the energy transfer have been discussed using schematic energy level diagram. The Tb3+/Yb3+ co-doped LB glass may be used in the optical devices and in solar cell for solar spectral conversion and behaves as a multi-modal photo-luminescent material.

  14. Effect of pyrophosphate ions on the conversion of calcium-lithium-borate glass to hydroxyapatite in aqueous phosphate solution.

    Science.gov (United States)

    Fu, Hailuo; Rahaman, Mohamed N; Day, Delbert E; Huang, Wenhai

    2010-10-01

    The conversion of glass to a hydroxyapatite (HA) material in an aqueous phosphate solution is used as an indication of the bioactive potential of the glass, as well as a low temperature route for preparing biologically useful materials. In this work, the effect of varying concentrations of pyrophosphate ions in the phosphate solution on the conversion of a calcium-lithium-borate glass to HA was investigated. Particles of the glass (150-355 μm) were immersed for up to 28 days in 0.25 M K(2)HPO(4) solution containing 0-0.1 M K(4)P(2)O(7). The kinetics of degradation of the glass particles and their conversion to HA were monitored by measuring the weight loss of the particles and the ionic concentration of the solution. The structure and composition of the conversion products were analyzed using X-ray diffraction, scanning electron microscopy, and Fourier transform infrared spectroscopy. For K(4)P(2)O(7) concentrations of up to 0.01 M, the glass particles converted to HA, but the time for complete conversion increased from 2 days (no K(4)P(2)O(7)) to 10 days (0.01 M K(4)P(2)O(7)). When the K(4)P(2)O(7) concentration was increased to 0.1 M, the product consisted of an amorphous calcium phosphate material, which eventually crystallized to a pyrophosphate product (predominantly K(2)CaP(2)O(7) and Ca(2)P(2)O(7)). The consequences of the results for the formation of HA materials and devices by the glass conversion route are discussed.

  15. 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.

  16. 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.

  17. Mixed alkali and alkaline-earth borate Li2Sr4B12O23 single crystal

    Science.gov (United States)

    Reshak, A. H.

    2015-10-01

    A comprehensive theoretical investigation of the electronic band structure, density of states, electron charge density distribution and the optical properties for mixed alkali and alkaline-earth borate Li2Sr4B12O23 (LSBO) single crystals were performed. The experimental geometrical structure was optimized by minimizing the forces acting on each atom. Calculations were performed using the full potential linear augmented plane wave plus local orbitals (FPLAPW + lo) method within the local density approximation (LDA), generalized gradient approximation (GGA) and the recently modified Becke-Johnson potential (mBJ). Our calculations show that LSBO crystal is a direct band gap semiconductor. The calculated band gap is 4.64 eV (LDA), 4.92 eV (GGA) and 5.51 eV (mBJ). An earlier calculation using the CASTEP code within LDA obtained a band gap of about 4.66 eV. To overcome the well-known LDA underestimation of the energy gap we have used GGA and mBJ . We find that mBJ succeed by large amount in bringing the calculated bond lengths in good agreement with the experimental data. Also we found that using mBJ to calculate the optical properties gives a birefringence of about 0.068 (at λ = 586.5 nm) in excellent agreement with the experimental data (0.068 at λ = 586.5 nm). Therefore, we believe that the mBJ calculations reported here show excellent agreement with the experimental data.

  18. 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....

  19. Synthesis and Application of Borate Ester Coupling Agent%硼酸酯偶联剂的合成与应用研究

    Institute of Scientific and Technical Information of China (English)

    郑俊良

    2014-01-01

    Using boric acid, isopropanol and octadecanol as main raw materials, strong acid ion exchange resin DNW-1 as catalyst, the borate ester coupling agent was prepared in N2 atmosphere condition. The influence of water carrying agent and mole ratio of raw materials on esterification rate was studied, and the borate ester coupling agent was characterized by IR and1H NMR. The results show that the best reaction conditions of the esterification reaction are as follows: the best water carrying agent is the mixture of benzol and toluene,n(boric acid):n(octadecanol):n(isopropanol)= 0.9: 2.0: 1.2; under above conditions, the esterification rate can reach to 94.57%.And the borate ester coupling agent prepared was used in the composite of brucite/HDPE. The result shows that the tensile strength of modified brucite/HDPE is better than the unmodified brucite/HDPE; when dosage of the borate ester coupling agent is 50%, the tensile strength of modified brucite/HDPE can increase by about 3.1%, and the value of LOI is 24.5.%以硼酸、异丙醇和十八醇为主要原料,催化剂是采用DNW-1强酸性离子交换树脂,在氮气保护下合成了硼酸酯偶联剂。考察了带水剂及物料摩尔比对酯化率的影响,并用红外光谱和1H NMR对硼酸酯进行了表征。研究发现:在n(硼酸)∶n(十八醇)∶n(异丙醇)=0.9∶2.0∶1.2的条件下,并采用苯和甲苯混合带水剂时,酯化率可达到94.57%。利用所合成的硼酸酯偶联剂应用于水镁石/HDPE 复合体系中,结果表明:改性水镁石/HDPE体系的拉伸强度高于未改性水镁石/HDPE体系的拉伸强度。添加量为50%时,改性水镁石的拉伸性能比未改性前提高了3.1%,LOI值为24.5。

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

    Science.gov (United States)

    Ortner, Teresa S.; Wurst, Klaus; Perfler, Lukas; Tribus, Martina; Huppertz, Hubert

    2015-01-01

    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.

  1. Pyrazole cleavage of tris(3,5-dimethylpyrazolyl)borate with Ruthenium(II) complexes: Synthesis, structural characterization and DFT studies

    Science.gov (United States)

    Kharbani, Donkupar; Deb, Debojit Kumar; Mawnai, Ibaniewkor L.; Kurbah, Sunshine D.; Sarkar, Biplab; Rymmai, E. K.

    2017-04-01

    The reaction of [Ru(H)(Cl)(CO)(PPh3)3] (1) with KTp* (KTp* = Potassium tris(3,5-dimethylpyrazolyl)borate) in a refluxing toluene yields a mixture of [RuTp*(H)(CO)(PPh3)] (2), [Ru(H)(Cl)(pz*H)(CO)(PPh3)2] (3), and [H(pz*)B(μ-pz*)2B(pz*)H] (4) (pz*H = 3,5-dimethylpyrazole). The products (3) and (4) were obtained by the degradation of the scorpionate ligand, Tp*. These complexes were characterised by IR, 1H NMR, UV, X-ray crystallography and DFT calculations.

  2. 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

  3. Molecular Interactions of the Difluoro(oxalato)borate Anion and Its Application for Lithium Ion Battery Electrolytes

    Science.gov (United States)

    Allen, Joshua Lee

    Understanding the molecular interactions within electrolyte mixtures is essential for designing next generation electrolyte materials for high-voltage lithium ion (Li-ion) battery applications. Despite significant advancements in Li-ion battery electrode materials, which have theoretically enabled cell operation in excess of 5 V (vs. Li/Li+), the state-of-the-art electrolyte formulation has remained largely unchanged over two decades after its initial commercialization. To optimize the electrolyte properties, it is crucial to understand and relate the molecular-level interactions to the measured bulk properties. In the present study, these interactions have been explored through the use of the following techniques: phase diagrams (DSC analysis), X-ray single crystal structural determination, spectroscopic vibrational analysis (Raman) of the solvent and anion bands, and other techniques for determining electrolyte physical and electrochemical properties (density, viscosity and ionic conductivity). The primary focus of the present work is on the difluoro(oxalato)borate (DFOB--) anion and how the properties of this anion differ from other anions used in Li-ion battery electrolyte mixtures. The synthesis of highly pure LiDFOB is reported, along with the X-ray single crystal structural analysis of the neat salt and its dihydrate (LiDFOB·2H2O). The ion coordination behavior of the DFOB-- anion is compared with the structurally similar BF4 . and lithium bis(oxalato)borate (BOB --) anions. The decomposition mechanism and Raman vibrational band assignments for the LiDFOB salt are also compared with those for LiBF 4 and LiBOB. The carbonate-based solvents ethylene carbonate (EC) and propylene carbonate (PC) are of extraordinary importance due to their applications in state-of-the-art electrolytes. The Raman analysis of EC- and PC-based electrolyte mixtures to determine solvation numbers, without appropriate correction factors, is inherently flawed due to varying Raman

  4. To immobilize polyethylene glycol-borate ester/lithium fluoride in graphene oxide/poly(vinyl alcohol for synthesizing new polymer electrolyte membrane of lithium-ion batteries

    Directory of Open Access Journals (Sweden)

    Y. F. Huang

    2017-01-01

    Full Text Available Polymer electrolyte membranes (PEMs are potentially applicable in lithium-ion batteries with high safety, low cost and good performance. Here, to take advantages of ionic conductivity and selectivity of borate ester-functionalized small molecules as well as structural properties of polymer nanocomposite, a strategy of immobilizing as-synthesized polyethylene glycol-borate ester/lithium fluoride (B-PEG/LiF in graphene oxide/poly(vinyl alcohol (GO/PVA to prepare a PEM is put forward. Chemical structure of the PEM is firstly characterized by 1H-, 11B- and 19F-nuclear magnetic resonance spectra, and Fourier transform infrared spectroscopy spectra, respectively, and then is further investigated under consideration of the interactions among PVA, B-PEG and LiF components. The immobilization of B-PEG/LiF in PVA-based structure is confirmed. As the interactions within electrolyte components can be further tuned by GO, ionic conductivity (~10–3 S·cm–1, lithium-ion transfer number (~0.49, and thermal (~273 °C/electrochemical (>4 V stabilities of the PEM can be obtained, and the feasibility of PEMs applied in a lithium-ion battery is also confirmed. It is believed that such PEM is a promising candidate as a new battery separator.

  5. Identification of ε-Fe{sub 2}O{sub 3} nano-phase in borate glasses doped with Fe and Gd

    Energy Technology Data Exchange (ETDEWEB)

    Ivanova, O.S.; Ivantsov, R.D. [L.V. Kirensky Institute of Physics, Siberian Branch of RAS, 660036 Krasnoyarsk (Russian Federation); Edelman, I.S., E-mail: ise@iph.krasn.ru [L.V. Kirensky Institute of Physics, Siberian Branch of RAS, 660036 Krasnoyarsk (Russian Federation); Petrakovskaja, E.A. [L.V. Kirensky Institute of Physics, Siberian Branch of RAS, 660036 Krasnoyarsk (Russian Federation); Velikanov, D.A. [L.V. Kirensky Institute of Physics, Siberian Branch of RAS, 660036 Krasnoyarsk (Russian Federation); Siberian Federal University, 660036 Krasnoyarsk (Russian Federation); Zubavichus, Y.V. [NRC “Kurchatov Institute”, 123182 Moscow (Russian Federation); Zaikovskii, V.I. [Boreskov Institute of Catalysis, Siberian Branch of RAS, 630090 Novosibirsk (Russian Federation); Novosibirsk State University, 630090 Novosibirsk (Russian Federation); Stepanov, S.A. [Vavilov State Optical Institute, All-Russia Research Center, 192371 Petersburg (Russian Federation)

    2016-03-01

    A new type of magnetic nanoparticles was revealed in borate glasses co-doped with low contents of iron and gadolinium. Structure and magnetic properties of the particles differ essentially from that of the α-Fe{sub 2}O{sub 3}, γ-Fe{sub 2}O{sub 3}, or Fe{sub 3}O{sub 4} nanoparticles which were detected earlier in similar glass matrices. Transmission electron microscopy including STEM-HAADF and EDX, synchrotron radiation-based XRD, static magnetic measurements, magnetic circular dichroism, and electron magnetic resonance studies allow referring the nanoparticles to the iron oxide phase-ε-Fe{sub 2}O{sub 3}. Analysis of the data set has shown that it is Gd atoms that govern the process of nanoparticles’ nucleation and its incorporation into the particles in different proportions can be used to adjust their magnetic and magneto-optical characteristics. - Highlights: • Alumina-potassium-borate glasses co-doped with Fe and Gd are studied. • Magnetic nanoparticles with structure close to ε-Fe{sub 2}O{sub 3} are shown to arise in glasses • Magnetic hysteresis loops and EMR evidence on the ferromagnetic and paramagnetic nano-phases coexistence. • Magnetic circular dichroism for ε-Fe{sub 2}O{sub 3} is studied for the first time.

  6. 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.

  7. Spectroscopic properties of Pr3+ and Er3+ ions in lead-free borate glasses modified by BaF2

    Science.gov (United States)

    Pisarska, Joanna; Pisarski, Wojciech A.; Dorosz, Dominik; Dorosz, Jan

    2015-09-01

    Lead-free oxyfluoride borate glasses singly doped with Pr3+ and Er3+ were prepared and next investigated using absorption and luminescence spectroscopy. In the studied glass system, barium oxide was substituted by BaF2. Two luminescence bands of Pr3+ located at visible spectral region are observed, which correspond to 3P0-3H4 (blue) and 1D2-3H4 (reddish orange) transitions, respectively. The luminescence bands due to 1D2-3H4 transition of Pr3+ are shifted to shorter wavelengths, when BaO was substituted by BaF2. Near-infrared luminescence spectra of Er3+ ions in lead-free borate glasses modified by BaF2 correspond to 4I13/2-4I15/2 transition. Their spectral linewidths increase with increasing BaF2 concentration. The changes in measured lifetimes of rare earth ions are well correlated with the bonding parameters calculated from the optical absorption spectra.

  8. 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

  9. 过氧化硼酸钾对脊髓灰质炎病毒灭活效果的研究%STUDY ON THE INACTIVATION EFFECT OF POTASSIUM BORATE PEROXIDE ON POLIOVIRUS

    Institute of Scientific and Technical Information of China (English)

    陈微娜; 张馨心; 王炜红; 曹原; 杨晶雪; 林玲

    2013-01-01

    目的 研究过氧化硼酸钾对脊髓灰质炎病毒的灭活效果.方法 采用病毒悬液定量灭活试验方法,对该过氧化硼酸钾灭活脊髓灰质炎病毒的效果进行了实验室观察.结果 用浓度为2 000 mg/L过氧化硼酸钾溶液作用时间3h,对悬液内脊髓灰质炎病毒的灭活对数值均≥4.00.结论 该过氧化硼酸钾对脊髓灰质炎病毒具有一定灭活作用.%Objective To study the inactivation effect of potassium borate peroxide on poliovirus. Methods The suspension quantitative inactivation test was used to study the inactivation effect of potassium borate peroxide on poliovirus in the laboratory. Results When the concentration of potassium borate peroxide solution was 2 000 mg/L and the duration time of action was 3 h, the inactivation logarithm values of poliovirus in suspension were all greater than or equal to 4. Conclusion The potassium borate peroxide has certain action on inactivating poliovirus.

  10. Thallium(I) complexes of fluorinated bis- and tris(pyrazolyl)borate ligands: [H2B{3,5-(CF3)2pz}2]Tl and [HB{3,5-(CF3)2pz}3]Tl.

    Science.gov (United States)

    Dias, H V Rasika; Thankamani, Jose

    2013-09-01

    X-ray crystal structural data at 100 (2) K for the thallium(I) complex of a fluorinated bis(pyrazolyl)borate, {bis[3,5-bis(trifluoromethyl)-1H-pyrazol-1-yl-κN(2)]borato}thallium(I), [Tl(C10H4BF12N4)], abbreviated as [H2B{3,5-(CF3)2pz}2]Tl, and the related tris(pyrazolyl)borate, {tris[3,5-bis(trifluoromethyl)-1H-pyrazol-1-yl-κN(2)]borato}thallium(I), [Tl(C15H4BF18N6)], abbreviated as [HB{3,5-(CF3)2pz}3]Tl, are reported. [H2B{3,5-(CF3)2pz}2]Tl features a two-coordinate Tl(I) atom with a bent geometry and a boat-shaped bis(pyrazolyl)borate ligand. It also has several additional inter- and intramolecular Tl···H and Tl···F contacts in the solid state. The tris(pyrazolyl)borate analogue [HB{3,5-(CF3)2pz}3]Tl has a trigonal-pyramidal thallium centre and features inter- and intramolecular Tl···F contacts.

  11. 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.

  12. FTIR, DTA and XRD study of sphene (CaTiSiO5)crystallization in a ceramic frit and a non-borate base glass

    Science.gov (United States)

    Chen, S. K.; Liu, H. S.

    1994-06-01

    The primary objective of this study has been the application of Fourier transform infrared (FTi.r.) absorption spectroscopy for both qualitative and quantitative characterization of sphene CaTiSiO5 crystallization in test materials; namely, a CaO-TiO2-B2O3 bearing ceramic frit-S and a similar non-borate base glass-S. Differential thermal analysis (DTA), x ray diffraction (XRD) and scanning electron microscope/electron probe x ray microanalysis (SEM/EPMA) techniques have also been used. FTi.r. absorption spectra have been shown to be capable of providing both qualitative and quantitative characterizations of crystal nucleation and growth in a frit-S and glass-S, being annealed between 800-1100 C. CaTiSiO5 appears as the dominant phase and alpha-cristobalite as the transitional phase in frit-S; whereas, beta-CaSiO3 is dominant, CaTiSiO5 being a minor phase in the non-borate glass-S. As given by DTA data, the intense stage of crystal growth for frit-S is about 120-125 C lower than that of glass-S. B2O3 content and the relative amounts of CaO and TiO2 in the test specimens have been shown to give different modes of phase evolution and the onset temperature of nucleation. The activation energies, E(sub c), of crystal nucleation/growth was estimated by two different methods, namely, via DTA data and FTi.r. absorption spectra under the dominant surface nucleation mode for powder pellet specimens. E(sub c) for CaTiSiO5, beta-CaSiO3 and alpha-cristobalite in the frit-S and the non-borate base glass-S were estimated to be 219.6, 107.2 and 51.5 kJ/mol respectively, parallel to the decreasing order of chemical complexity of the glass-forming system. Similar quantitative FTi.r. studies in the determination of E(sub c) for a broader scope of glass compositions, and compared with that based on XRD and DTA data, are to be encouraged so that the application of FTi.r. spectroscopy in glass-ceramics may be advanced.

  13. 水溶性硼酸酯的摩擦学性能研究%STUDY ON THE TRIBOLOGICAL PROPERTIES OF WATERSOLUBLE BORATE

    Institute of Scientific and Technical Information of China (English)

    黄伟九; 陈波水; 董浚修

    2001-01-01

    The tribological properties of water-soluble borate are evaluated using four-ball machine and HQ-1 block-on-ring tribotester. The rubbed surface is investigated using X-ray photoelectron spectroscopy and electronic probe analysis. The tribological test results show that the water-soluble borate has good lubricating performance and load-carrying capacity. The surface analyses show that the content of element boron, nitrogen and sulphur in wear scar surface is well-distributed. The borate reacted with the metal surface in friction process and produced a complex film composed of organic nitrogen, boric acid, boron oxide, iron disulfide, ferrous sulfate and tribopolymer, which is effective on improving the antiwear, friction-reduction and load-carrying capacity of water-based fluid.%利用四球机和环块试验机考察了一种水溶性硼酸酯在水中的摩擦学性能,并用X射线光电子能谱仪(XPS)和电子探针(EPMA)对摩擦表面进行了分析。摩擦学试验表明:水溶性硼酸酯在水中具有良好的润滑性能和承载能力。表面分析证明元素S,N和B在磨斑表面分布比较均匀,且B和S元素发生了摩擦化学反应。水溶性硼酸酯的抗磨作用机理是其在摩擦过程中发生了摩擦化学反应,生成了含硼酸、三氧化二硼、有机氮、二硫化亚铁、硫酸亚铁及摩擦聚合物等的复合膜,有效地提高了水基液的减摩抗磨性能。

  14. Wound dressings composed of copper-doped borate bioactive glass microfibers stimulate angiogenesis and heal full-thickness skin defects in a rodent model.

    Science.gov (United States)

    Zhao, Shichang; Li, Le; Wang, Hui; Zhang, Yadong; Cheng, Xiangguo; Zhou, Nai; Rahaman, Mohamed N; Liu, Zhongtang; Huang, Wenhai; Zhang, Changqing

    2015-01-01

    There is a need for better wound dressings that possess the requisite angiogenic capacity for rapid in situ healing of full-thickness skin wounds. Borate bioactive glass microfibers are showing a remarkable ability to heal soft tissue wounds but little is known about the process and mechanisms of healing. In the present study, wound dressings composed of borate bioactive glass microfibers (diameter = 0.4-1.2 μm; composition 6Na2O, 8K2O, 8MgO, 22CaO, 54B2O3, 2P2O5; mol%) doped with 0-3.0 wt.% CuO were created and evaluated in vitro and in vivo. When immersed in simulated body fluid, the fibers degraded and converted to hydroxyapatite within ∼7 days, releasing ions such as Ca, B and Cu into the medium. In vitro cell culture showed that the ionic dissolution product of the fibers was not toxic to human umbilical vein endothelial cells (HUVECs) and fibroblasts, promoted HUVEC migration, tubule formation and secretion of vascular endothelial growth factor (VEGF), and stimulated the expression of angiogenic-related genes of the fibroblasts. When used to treat full-thickness skin defects in rodents, the Cu-doped fibers (3.0 wt.% CuO) showed a significantly better capacity to stimulate angiogenesis than the undoped fibers and the untreated defects (control) at 7 and 14 days post-surgery. The defects treated with the Cu-doped and undoped fibers showed improved collagen deposition, maturity and orientation when compared to the untreated defects, the improvement shown by the Cu-doped fibers was not markedly better than the undoped fibers at 14 days post-surgery. These results indicate that the Cu-doped borate glass microfibers have a promising capacity to stimulate angiogenesis and heal full-thickness skin defects. They also provide valuable data for understanding the role of the microfibers in healing soft tissue wounds. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Synthesis and characterization of the lead borate Pb{sub 6}B{sub 12}O{sub 21}(OH){sub 6}

    Energy Technology Data Exchange (ETDEWEB)

    Schoenegger, Sandra; Ortner, Teresa S.; Wurst, Klaus; Heymann, Gunter; Huppertz, Hubert [Innsbruck Univ. (Austria). Inst. fuer Allgemeine, Anorganische und Theoretische Chemie

    2016-11-01

    A lead borate with the composition Pb{sub 6}B{sub 12}O{sub 21}(OH){sub 6} was synthesized through a hydrothermal synthesis, using lead metaborate in combination with sodium nitrate and potassium nitrate. The compound crystallizes in the trigonal, non-centrosymmetric space group P3{sub 2} (no. 145) with the lattice parameters a = 1176.0(4), c = 1333.0(4) pm, and V = 0.1596(2) nm{sup 3}. Interestingly, the data of Pb{sub 6}B{sub 12}O{sub 21}(OH){sub 6} correct the structure of a literature known lead borate with the composition ''Pb{sub 6}B{sub 11}O{sub 18}(OH){sub 9}''. For the latter compound, nearly identical lattice parameters of a = 1176.91(7) and c = 1333.62(12) pm were reported, possessing a crystal structure, in which the localization and refinement of one boron atom was obviously overlooked. The structure of Pb{sub 6}B{sub 12}O{sub 21}(OH){sub 6} is built up from trigonal planar BO{sub 3} and tetrahedral BO{sub 4} groups forming complex chains. The Pb{sup 2+} cations are located between neighboring polyborate chains. The here reported compound Pb{sub 6}B{sub 12}O{sub 21}(OH){sub 6} and ''Pb{sub 6}B{sub 11}O{sub 18}(OH){sub 9}'' were, however, produced under different synthesis conditions. While ''Pb{sub 6}B{sub 11}O{sub 18}(OH){sub 9}'' was synthesized via a hydrothermal synthesis including ethylenediamine and acetic acid, the here reported lead borate Pb{sub 6}B{sub 12}O{sub 21}(OH){sub 6} could be obtained under moderate hydrothermal conditions (240 C) without the addition of organic reagents.

  16. 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.

  17. Temperature measurements using a projection to latent structures of fluorescence spectra of potassium-aluminum borate glasses with copper-containing molecular clusters

    Science.gov (United States)

    Babkina, A. N.; Khodasevich, M. A.; Shirshnev, P. S.

    2017-02-01

    Luminescence spectra of a potassium-aluminum borate glass with copper-containing molecular clusters are presented in the temperature range of 295-624 K. Two methods of temperature measurement are compared with the aim of evaluating the possibility of their further application in optical temperature sensors: specifically, the classical method of measuring a temperature based on the spectral position of the fluorescence band peak and the measurement method based on projection to latent structures of fluorescence spectra in the visible range. It is shown that, concerning the accuracy of measuring a temperature, the fourdimensional space of latent structures is preferred for the case under consideration; it allows one to determine (using a training set of fluorescence spectra) a temperature with the relative error of no more than 1.2%.

  18. 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.

  19. Polarity and Chirality in Uranyl Borates: Insights into Understanding the Vitrification of Nuclear Waste and the Development of Nonlinear Optical Materials

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shuao; Alekseev, Evgeny V.; Ling, Jie; Liu, Guokui; Depmeier, Wulf; Albrecht-Schmitt, Thomas E.

    2010-03-23

    Four new sodium uranyl borates, α-Na[(UO{sub 2}){sub 2}B{sub 10}O{sub 15}(OH){sub 5})] (NaUBO-1), β-Na[(UO{sub 2}){sub 2}B{sub 10}O{sub 15}(OH){sub 5}] (NaUBO-2), Na[(UO{sub 2}){sub 2}B{sub 10}O{sub 15}(OH){sub 5}]·3H{sub 2}O (NaUBO-3), and Na[(UO{sub 2})B{sub 6}O{sub 10}(OH)]·2H{sub 2}O (NaUBO-4), and four new thallium uranyl borates, α-Tl{sub 2}[(UO{sub 2}){sub 2}B{sub 11}O{sub 18}(OH){sub 3}] (TlUBO-1), β-Tl{sub 2}[(UO{sub 2}){sub 2}B{sub 11}O{sub 18}(OH){sub 3}] (TlUBO-2), Tl[(UO{sub 2}){sub 2}B{sub 10}O{sub 16}(OH){sub 3}] (TlUBO-3), and Tl{sub 2}[(UO{sub 2}){sub 2}B{sub 11}O{sub 19}(OH)] (TlUBO-4), have been prepared via the reaction of sodium nitrate or thallium nitrate, uranyl nitrate, and excess boric acid at 190 °C. These compounds share a common structural motif consisting of a linear uranyl, UO{sub 2}{sup 2+}, cation surrounded by BO{sub 3} triangles and BO{sub 4} tetrahedra to create a UO{sub 8} hexagonal bipyramidal environment around uranium. The borate anions bridge between uranyl units to create sheets. Additional BO{sub 3} triangles extend from the polyborate layers and are directed approximately perpendicular to the sheets. In some compounds, these units can link the layers together to yield three-dimensional networks with large pores to house the Na{sup +} or Tl{sup+} cations and water molecules. The structures are all noncentrosymmetric and are either polar or chiral. While the uranyl borate layers are noncentrosymmetric in and of themselves, there is also twisting of the interlayer BO{sub 3} groups to reduce the interlayer spacing, producing helical features in some structures. Na[(UO{sub 2})B{sub 6}O{sub 10}(OH)]·2H{sub 2}O and β-Tl{sub 2}[(UO{sub 2}){sub 2}B{sub 11}O{sub 18}(OH){sub 3}], which can be obtained as pure phases, display second-harmonic generation of 532 nm light from 1064 nm light.

  20. 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.

  1. Anhydrous lithium borate, Li{sub 3}B{sub 11}O{sub 18}, crystal structure, phase transition and thermal expansion

    Energy Technology Data Exchange (ETDEWEB)

    Sennova, Natalia [Techinsche Univ. Darmstadt (Germany). Eduard-Zintl-Inst. fuer Anorganische und Physikalische Chemie; St. Petersburg State Univ. (Russian Federation). Dept. of Crystallographie; Albert, Barbara [Techinsche Univ. Darmstadt (Germany). Eduard-Zintl-Inst. fuer Anorganische und Physikalische Chemie; Bubnova, Rimma [St. Petersburg State Univ. (Russian Federation). Dept. of Crystallographie; Russian Academy of Science, St. Petersburg (Russian Federation). Inst. of Silicate Chemistry; Krzhizhanovskaya, Maria; Filatov, Stanislav [St. Petersburg State Univ. (Russian Federation). Dept. of Crystallographie

    2014-10-01

    A new lithium borate, Li{sub 3}B{sub 11}O{sub 18}, was synthesized by crystallization from glass, containing an excess of B{sub 2}O{sub 3}. The compound crystallizes monoclinic, P2{sub 1}/a, Z=4, a=9.766(5) Aa, b=7.849(5) Aa, c=17.899(9) Aa, β=100.96(5) circle, V=1347.0(13) Aa{sup 3} (R=0.06, wR=0.12). The structure is based upon two interpenetrating frameworks formed by triborate and pentaborate groups. The thermal behaviour of Li{sub 3}B{sub 11}O{sub 18} was studied using DTA, DSC, and high-temperature XRD. Highly anisotropic thermal expansion and a new high-temperature phase were observed.

  2. Assessment of an Increase in Boron and Arsenic Concentrations at the Discharge Area of Na-Borate Mine (Kirka-Eskisehir, Turkey

    Directory of Open Access Journals (Sweden)

    Galip Yuce Didem Ugurluoglu Yasin

    2012-01-01

    Full Text Available The Province of Kirka (Eskisehir, Turkey, located in the catchment of the Seydisuyu Plain, has one of the largest Na-borate deposits in the world. However, boron concentrations in surface and ground waters downstream of Kirka Province, the Seyitgazi Plain, have increased over the past twenty years. Seyitgazi plain has been widely irrigated from groundwater and Seydisuyu River. In this respect, quality of the river water directly affects groundwater quality in the Seyitgazi Plain since river water is the main supplier for irrigation water in the Seyitgazi plain in addition to groundwater which is extracted from the wells drilled in the Seyitgazi Plain. Thus, any mining activity built in the catchment area of groundwater poses potential risk for the quality of groundwater in the discharge area.

  3. Interference-free coulometric titration of water in lithium bis(oxalato)borate using Karl Fischer reagents based on N-methylformamide.

    Science.gov (United States)

    Larsson, William; Panitz, Jan-Christoph; Cedergren, Anders

    2006-03-15

    A non-alcoholic coulometric reagent based on N-methylformamide (NMF) was shown to eliminate the severe interference effect caused by the alcohol component of the conventional Karl Fischer (KF) reagent on the battery electrolyte lithium bis(oxalato)borate (LiBOB). For sample amounts up to 240 microg of water, the stoichiometry of the KF reaction deviated only slightly from the ideal 1:1 ratio for the best reagent composition. Both solid and dissolved (in acetonitrile, tetrahydrofuran (THF), and ethylene carbonate/ethyl methyl carbonate) LiBOB were titrated successfully using a Metrohm 756 KF Coulometer with a diaphragm cell. The detection limit was estimated to be 0.5-1 microg of water using 100ml of reagent in this system.

  4. Dual role of the six-coordinated molybdenum and lead ions in novel of photochromic properties of the molybdenum-lead-borate glasses

    Science.gov (United States)

    Rada, M.; Maties, V.; Culea, M.; Rada, S.; Culea, E.

    2010-02-01

    Transparent glasses were prepared by conventional melting-quenching method in the xMoO 3·(100 - x)[3B 2O 3·PbO] system where 0 ≤ x ≤ 15 mol%. By increasing the MoO 3 content up to 20 mol% the PbMoO 4 crystalline phase appears. These systems exhibit a photochromic effect which can be induced through laser exposures ( λ = 633 nm) directly on the bulk sample. Structural investigations by FTIR spectroscopy show that the photosensitive effect is due to a reduction of Mo 6+ to Mo 4+ and/or Mo 5+ promoted by the oxidation of Pb 2+ and some structural changes of the borate network.

  5. Luminescence properties of Dy{sup 3+} ions in a variety of borate and fluoroborate glasses containing lithium, zinc, and lead

    Energy Technology Data Exchange (ETDEWEB)

    Jayasankar, C.K.; Venkatramu, V.; Surendra Babu, S.; Babu, P

    2004-07-14

    The fluorescence properties of Dy{sup 3+} 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 {sup 4}F{sub 9/2} level of Dy{sup 3+} 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{yields}Li{sub 2}O{yields}ZnO{yields}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.

  6. 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

  7. Characterization of Al{sub 2}O{sub 3} ceramic coatings on 6063 aluminum alloy prepared in borate electrolytes by micro-arc oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Li, H.X. [MOE Key Laboratory of Mechanical Manufacture and Automation, Zhejiang University of Technology, No. 6, Zhaohui District, Hangzhou 310014 (China); Rudnev, V.S. [Institute of Chemistry FEB RAS, Pr. 100 let Vladivostok, Vladivostok 690022 (Russian Federation); Zheng, X.H. [MOE Key Laboratory of Mechanical Manufacture and Automation, Zhejiang University of Technology, No. 6, Zhaohui District, Hangzhou 310014 (China); Yarovaya, T.P. [Institute of Chemistry FEB RAS, Pr. 100 let Vladivostok, Vladivostok 690022 (Russian Federation); Song, R.G. [MOE Key Laboratory of Mechanical Manufacture and Automation, Zhejiang University of Technology, No. 6, Zhaohui District, Hangzhou 310014 (China)], E-mail: songrg@zjut.edu.cn

    2008-08-25

    Al{sub 2}O{sub 3} ceramic coatings were directly prepared on 6063 aluminum alloy in borate electrolytes by micro-arc oxidation technique. The microstructure, phase composition, elemental distribution, and micro-hardness of Al{sub 2}O{sub 3} ceramic coatings were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and micro-hardness test. The fabricated samples were almost composed of {alpha}-Al{sub 2}O{sub 3} and {gamma}-Al{sub 2}O{sub 3}, also there existed pores and cracks on the surface of the coatings. Micro-hardness test shows that the prepared coatings are of high hardness, which can satisfy the requirements for the mechanical application.

  8. Magnetic Relaxation Switch Detecting Boric Acid or Borate Ester through One-Pot Synthesized Poly(vinyl alcohol) Functionalized Nanomagnetic Iron Oxide.

    Science.gov (United States)

    Zhang, Guilong; Lu, Shiyao; Qian, Junchao; Zhong, Kai; Yao, Jianming; Cai, Dongqing; Cheng, Zhiliang; Wu, Zhengyan

    2015-08-05

    We developed a highly efficient magnetic relaxation switch (MRS) system based on poly(vinyl alcohol) functionalized nanomagnetic iron oxide (PVA@NMIO) particles for the detection of boric acid or borate ester (BA/BE). It was found that the addition of BA/BE induced the aggregation of PVA@NMIO particles, resulting in a measurable change in the T2 relaxation time in magnetic resonance measurements. The main mechanism was proposed that the electron-deficient boron atoms of BA/BE caused the aggregation of PVA@NMIO particles through covalent binding to the hydroxyl groups of PVA. This novel detection system displayed excellent selectivity, high sensitivity, and rapid detection for BA/BE. Thus, this system may provide a great application prospect for detection of BA/BE.

  9. 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.

  10. X-ray diffraction, X-ray photoelectron spectra, crystal structure, and optical properties of centrosymmetric strontium borate Sr2B16O26.

    Science.gov (United States)

    Reshak, Ali Hussain; Auluck, S; Kityk, I V; Chen, Xuean

    2009-07-09

    We report results of X-ray diffraction (XRD) and valence band X- ray photoelectron (VB-XPS) spectra for strontium borate Sr(2)B(16)O(26). The X-ray structural analysis shows that the single crystals of Sr(2)B(16)O(26) crystallize in the monoclinic space group P2(1)/c with a = 8.408(1) A, b = 16.672(1) A, c = 13.901(2) A, beta = 106.33(1) degrees , and Z = 4. The crystal structure consists of a 3D network of the complex borate anion [B(16)O(20)O(12/2)](4-), formed by 12 BO(3) triangles and four BO(4) tetrahedra, which can be viewed as three linked [B(3)O(3)O(4/2)](-) triborate groups bonded to one pentaborate [B(5)O(6)O(4/2)](-) group and two BO(3) triangles. Using this structure, we have performed theoretical calculations using the all-electron full potential linearized augmented plane wave (FP-LAPW) method for the band structure, density of states, electron charge density, and the frequency-dependent optical properties. Our experimental VB-XPS of Sr(2)B(16)O(26) is compared with results of our FP-LAPW calculations. Our calculations show that the valence band maximum (VBM) and conduction band minimum (CBM) are located at Gamma of the Brillouin zone (BZ) resulting in a direct energy gap of about 5.31 eV. Our measured VB-XPS show reasonable agreement with our calculated total density of states for the valence band that is attributed to the use of the full potential method.

  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. 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)

  13. Hydrothermal synthesis and characterization of the first mixed alkali borate-nitrate K{sub 3}Na[B{sub 6}O{sub 9}(OH){sub 3}]NO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Ortner, Teresa S.; Wurst, Klaus [Institut für Allgemeine, Anorganische und Theoretische Chemie, Leopold-Franzens-Universität Innsbruck, Innrain 80-82, A-6020 Innsbruck (Austria); Perfler, Lukas; Tribus, Martina [Institut für Mineralogie und Petrographie, Leopold-Franzens-Universität Innsbruck, Innrain 52, A-6020 Innsbruck (Austria); Huppertz, Hubert, E-mail: Hubert.Huppertz@uibk.ac.at [Institut für Allgemeine, Anorganische und Theoretische Chemie, Leopold-Franzens-Universität Innsbruck, Innrain 80-82, A-6020 Innsbruck (Austria)

    2015-01-15

    The first mixed alkali borate-nitrate K{sub 3}Na[B{sub 6}O{sub 9}(OH){sub 3}]NO{sub 3} was synthesized under hydrothermal conditions from Na{sub 2}B{sub 4}O{sub 7}·10H{sub 2}O and K{sub 2}B{sub 4}O{sub 7}·4H{sub 2}O using KNO{sub 3} 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 BO{sub 4} and BO{sub 3} groups are linked through hydrogen bridges to form a three-dimensional network. - Graphical abstract: The first mixed alkali borate-nitrate K{sub 3}Na[B{sub 6}O{sub 9}(OH){sub 3}]NO{sub 3} was synthesized under hydrothermal conditions from Na{sub 2}B{sub 4}O{sub 7}·10H{sub 2}O and K{sub 2}B{sub 4}O{sub 7}·4H{sub 2}O using KNO{sub 3} as a nitrate source. - Highlights: • The first mixed alkali borate-nitrate K{sub 3}Na[B{sub 6}O{sub 9}(OH){sub 3}]NO{sub 3} is reported. • Hydrothermal conditions (240 °C, 3d) were used for the synthesis of K{sub 3}Na[B{sub 6}O{sub 9}(OH){sub 3}]NO{sub 3}. • Borate Sechserrings are interconnected through hydrogen-bonding.

  14. Highly efficient aldol additions of DHA and DHAP to N-Cbz-amino aldehydes catalyzed by L-rhamnulose-1-phosphate and L-fuculose-1-phosphate aldolases in aqueous borate buffer.

    Science.gov (United States)

    Garrabou, Xavier; Calveras, Jordi; Joglar, Jesús; Parella, Teodor; Bujons, Jordi; Clapés, Pere

    2011-12-21

    Aldol addition reactions of dihydroxyacetone (DHA) to N-Cbz-amino aldehydes catalyzed by L-rhamnulose-1-phosphate aldolase (RhuA) in the presence of borate buffer are reported. High yields of aldol adduct (e.g. 70-90%) were achieved with excellent (>98 : 2 syn/anti) stereoselectivity for most S or R configured acceptors, which compares favorably to the reactions performed with DHAP. The stereochemical outcome was different and depended on the N-Cbz-amino aldehyde enantiomer: the S acceptors gave the syn (3R,4S) aldol adduct whereas the R ones gave the anti (3R,4R) diastereomer. Moreover, the tactical use of Cbz protecting group allows simple and efficient elimination of borate and excess of DHA by reverse phase column chromatography or even by simple extraction. This, in addition to the use of unphosphorylated donor nucleophile, makes a useful and expedient methodology for the synthesis of structurally diverse iminocyclitols. The performance of aldol additions of dihydroxyacetone phosphate (DHAP) to N-Cbz-amino aldehydes using RhuA and L-fuculose-1-phosphate aldolase (FucA) catalyst in borate buffer was also evaluated. For FucA catalysts, including FucA F131A, the initial velocity of the aldol addition reactions using DHAP were between 2 and 10 times faster and the yields between 1.5 and 4 times higher than those in triethanolamine buffer. In this case, the retroaldol velocities measured for some aldol adducts were lower than those without borate buffer indicating some trapping effect that could explain the improvement of yields.

  15. Synthesis, single-crystal structure determination, and vibrational spectroscopy of the europium borate Eu[B{sub 6}O{sub 8}(OH){sub 5}].H{sub 3}BO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Ortner, Teresa S.; Wurst, Klaus; Huppertz, Hubert [Institut fuer Allgemeine, Anorganische und Theoretische Chemie, Leopold-Franzens-Universitaet Innsbruck (Austria); Seibald, Markus [OSRAM GmbH, Corporate Innovation, Schwabmuenchen (Germany); Joachim, Bastian [Institut fuer Mineralogie und Petrographie, Leopold-Franzens-Universitaet Innsbruck (Austria)

    2016-07-15

    The new europium borate Eu[B{sub 6}O{sub 8}(OH){sub 5}].H{sub 3}BO{sub 3} was obtained by hydrothermal synthesis from europium nitrate hydrate and boric acid. The compound crystallizes in the triclinic space group P1 (no. 2) with the lattice parameters a = 681.59(3), b = 714.17(3), c = 1271.88(6) pm, α = 96.02(1), β = 98.60(1), γ = 101.73(1) (Z = 2). The structure of Eu[B{sub 6}O{sub 8}(OH){sub 5}].H{sub 3}BO{sub 3} is isotypic to that of the samarium borate Sm[B{sub 6}O{sub 8}(OH){sub 5}].H{sub 3}BO{sub 3} and is built up from tetrahedral BO{sub 4} and trigonal-planar BO{sub 3} units, both of which are protonated at terminal and bridging oxygen positions. Boric acid molecules reside between the borate layers. Through hydrogen bonding, the structure forms a three-dimensional network. In channels down [110], the Eu{sup 3+} cations are eightfold coordinated by oxygen ions. The compound was also characterized by IR and Raman spectroscopy, and it shows typical Eu{sup 3+} line emission. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. The influence of CdSe and ZnSe nanoparticles on the optical properties of Sm3+ ions in lead borate glasses

    Science.gov (United States)

    Mallur, Saisudha B.; Heidorn, William D.; Fatokun, Stephen O.; Joshi, Krishna D.; Bista, Sandip S.; Babu, Panakkattu K.

    2017-03-01

    The effect of glass composition and the presence of CdSe/ZnSe nanoparticles (NPs) on the optical absorption and fluorescence of Sm-doped lead borate glasses are studied. Three sets of glass samples xPbO:(99.5-x) B2O3:0.5Sm2O3, x = 29.5-69.5 mol%, xPbO:(96.5-x) B2O3:0.5Sm2O3: 3CdSe/ZnSe, x = 36.5, and 56.5 mol% are prepared. NPs are grown by annealing these glasses just below the glass transition temperature. Average size of both types of NPs increases with annealing time; however, CdSe NPs grew to a larger size range (2 to 20 nm) compared to ZnSe NPs (1 to 16 nm). We analyzed the hypersensitive transition, intensity parameters, radiative transition probability, stimulated emission cross section (σp), and the area ratio of the electric dipole/magnetic dipole transitions of Sm3+. The intensity parameters show a minimum at 11 h annealing for 36.5 mol% and a maximum for the same annealing duration in 56.5 mol% PbO containing CdSe NPs. The σp for 56.5 mol% of PbO with CdSe NPs is found to be a maximum when the average NP size is around 14 nm. ZnSe NPs containing glasses also show significant changes in σp when the average particle size is 16 nm, for 36.5 mol% PbO. Our results suggest that the optical properties of Sm3+ in lead borate glasses are sensitive to its electronic environment which can be modified by varying the base glass composition and/or incorporating large NPs of CdSe/ZnSe. The large σp values that we observe for some of the glass compositions make them attractive materials for photonic devices and photovoltaic applications.

  17. 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.

  18. 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.

  19. Characterisation of passive films formed on low carbon steel in borate buffer solution (pH 9.2) by electrochemical impedance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Hamadou, L. [Laboratoire de Materiaux, Electrochimie et Corrosion, Universite Mouloud MAMMERI de, Tizi-Ouzou, B.P. 17 (15000) (Algeria)]. E-mail: lamhama@yahoo.fr; Kadri, A. [Laboratoire de Materiaux, Electrochimie et Corrosion, Universite Mouloud MAMMERI de, Tizi-Ouzou, B.P. 17 (15000) (Algeria); Benbrahim, N. [Laboratoire de Materiaux, Electrochimie et Corrosion, Universite Mouloud MAMMERI de, Tizi-Ouzou, B.P. 17 (15000) (Algeria)

    2005-12-15

    The comprehension of passivity and its protective character against corrosion is closely connected with the electronic properties of passive films. Passive films formed anodically on carbon steel in borate/boric acid solution, pH 9.2, have been characterised by electrochemical impedance spectroscopy (EIS). Mott-Schottky plots and impedance measurements were made on films formed at different potentials and times. The investigation allowed the determination of the semiconductive properties of the films. The results of the capacitance response indicate that the passive films behave like highly doped n-type semiconductors, showing that the passive film properties are dominated by iron. The value of donors density (N {sub D}) for the passive film is of the order of 10{sup 21} cm{sup -3} and decreases with increasing formation time and potential, indicating that defects decrease with increasing film thickness. Based on the information about the physical phenomena, an equivalent circuit is proposed to fit the experimental data, leading to determination of anodic film capacitance and film resistance.

  20. 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 reaction rate depended linearly on the complex concentration, indicating a first-order dependence on the catalyst concentration.

  1. 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.

  2. 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.

  3. Substitution disorder and photoluminescent property of a new rare-earth borate: K{sub 3}TbB{sub 6}O{sub 12}

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Dan; Ma, Fa-Xue; Huang, Min; Chen, Peng-Fei; Zhang, Rong-Hua [Henan Polytechnic Univ., Jiaozuo (China). College of Chemistry and Chemical Engineering; Zhang, Rui-Juan [Henan Polytechnic University, Jiaozuo (China). Academic Affairs Office; Wei, Wei [Capital Normal Univ., Beijing (China). Dept. of Chemistry

    2016-11-01

    A new rare-earth borate K{sub 3}TbB{sub 6}O{sub 12} has been prepared using the high temperature molten salt method and was structurally determined by single crystal X-ray diffraction analyses. The structure features a three-dimensional (3D) framework which is composed of isolated B{sub 5}O{sub 10}, KO{sub 6}, KO{sub 8} and TbO{sub 6} groups. An atom site in the 3{sub 2} screw axis is shared by K and Tb atoms with the molar ratio of 1:1. The self-activated photoluminescence (PL) property of K{sub 3}TbB{sub 6}O{sub 12} was studied. Under the excitation of 378 nm, the emission spectrum exhibits an intense green emission centered at 543-548 nm with the chromaticity coordinates (0.342, 0.590), which can be assigned to the {sup 5}D{sub 4} → {sup 7}F{sub 5} transition of Tb{sup 3+}. The excitation spectra cover a wide range from 330 to 385 nm, which suggests that the K{sub 3}TbB{sub 6}O{sub 12} phosphors can be effectively excited by a near-UV light source. One may expect that compound K{sub 3}TbB{sub 6}O{sub 12} can be used as a green phosphor pumped by near-UV LED chips.

  4. 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.

  5. The high-pressure cadmium borate Cd{sub 6}B{sub 22}O{sub 39} . H{sub 2}O

    Energy Technology Data Exchange (ETDEWEB)

    Sohr, Gerhard; Ciaghi, Nina; Wurst, Klaus; Huppertz, Hubert [Innsbruck Univ. (Austria). Inst. fuer Allgemeine, Anorganische und Theoretische Chemie

    2015-06-01

    Single crystals of the hydrous cadmium borate Cd{sub 6}B{sub 22}O{sub 39} . H{sub 2}O were obtained through a high-pressure/high-temperature experiment at 4.7 GPa and 1000 C using a Walker-type multianvil apparatus. CdO and partially hydrolyzed B{sub 2}O{sub 3} were used as starting materials. A single crystal X-ray diffraction study has revealed that the structure of Cd{sub 6}B{sub 22}O{sub 39} . H{sub 2}O is similar to that of the type M{sub 6}B{sub 22}O{sub 39} . H{sub 2}O (M=Fe, Co). Layers of corner-sharing BO{sub 4} groups are interconnected by BO{sub 3} groups to form channels containing the metal cations, which are six- and eight-fold coordinated by oxygen atoms. The compound crystallizes in the space group Pnma (no. 62) [R1=0.0379, wR2=0.0552 (all data)] with the unit cell dimensions a=1837.79(5), b=777.92(2), c=819.08(3) pm, and V=1171.00(6) Aa{sup 3}. The IR and Raman spectra reflect the structural characteristics of Cd{sub 6}B{sub 22}O{sub 39} . H{sub 2}O.

  6. High-pressure synthesis and characterization of the rare-earth fluoride borate LaB{sub 2}O{sub 4}F

    Energy Technology Data Exchange (ETDEWEB)

    Hinteregger, Ernst; Kocsis, Krisztina; Hofer, Thomas S.; Heymann, Gunter; Huppertz, Hubert [Innsbruck Univ. (Austria). Inst. fuer Allgemeine, Anorganische und Theoretische Chemie; Perfler, Lukas [Innsbruck Univ. (Austria). Inst. fuer Mineralogie und Petrographie

    2013-09-15

    The rare-earth fluoride borate LaB{sub 2}O{sub 4}F was synthesized under high-pressure/high-temperature conditions of 1.1 GPa and 1300 C in a Walker-type multianvil apparatus from lanthanum oxide, lanthanum fluoride, and boron oxide. The single-crystal structure determination revealed that LaB{sub 2}O{sub 4}F is isotypic to CeB{sub 2}O{sub 4}F. The compound crystallizes in the orthorhombic space group Pbca (no. 61) with eight formula units and the lattice parameters a = 8.2493(9), b = 12.6464(6), c = 7.3301(5) A, V = 764.7(2) A{sup 3}, R{sub 1} = 0.0354, and wR{sub 2} = 0.0474 (all data). The structure exhibits a 9+1 coordinated lanthanum cation, one threefold coordinated fluoride ion and a chain of corner-sharing [BO{sub 3}]{sup 3-} groups. In addition to the IR- and Raman-spectroscopic investigations, DFT calculations were performed to support the assignment of the vibrational bands. (orig.)

  7. High-pressure synthesis and crystal structure of the borate Sc{sub 3}B{sub 5}O{sub 12}

    Energy Technology Data Exchange (ETDEWEB)

    Neumair, Stephanie C.; Huppertz, Hubert [Inst. fuer Allgemeine, Anorganische und Theoretische Chemie, Leopold-Franzens-Univ. Innsbruck (Austria)

    2009-11-15

    The rare-earth borate Sc{sub 3}B{sub 5}O{sub 12} was synthesized under high-pressure/high-temperature conditions of 6 GPa and 1100 C in a Walker-type multianvil apparatus. The single-crystal structure determination revealed an isotypy to RE{sub 3}B{sub 5}O{sub 12} (RE = Er-Lu). Sc{sub 3}B{sub 5}O{sub 12} crystallizes in the rare space group Pmna (Z = 4) with the parameters a = 1245.4(3), b = 443.46(9), c = 1222.1 (2) pm, V = 0.675(1) nm{sup 3}, R{sub 1} = 0.0520, and wR{sub 2} = 0.0860 (all data). The structure of Sc{sub 3}B{sub 5}O{sub 12} is composed of layers of condensed BO{sub 4} tetrahedra, separated by eight-fold coordinated scandium ions. (orig.)

  8. High-pressure synthesis and characterization of the fluoride borate Tm{sub 5}(BO{sub 3}){sub 2}F{sub 9}

    Energy Technology Data Exchange (ETDEWEB)

    Haberer, Almut; Enders, Michael; Huppertz, Hubert [Inst. fuer Allgemeine, Anorganische und Theoretische Chemie, Leopold-Franzens-Univ., Innsbruck (Austria); Kaindl, Reinhard [Inst. fuer Mineralogie und Petrographie, Leopold-Franzens-Univ. Innsbruck (Austria)

    2010-10-15

    The rare earth fluoride borate Tm{sub 5}(BO{sub 3}){sub 2}F{sub 9} was synthesized from Tm{sub 2}O{sub 3}, B{sub 2}O{sub 3}, and TmF{sub 3} under high-pressure/high-temperature conditions of 5 GPa and 900 C in a Walker-type multianvil apparatus. The single-crystal structure determination revealed that Tm{sub 5}(BO{sub 3}){sub 2}F{sub 9} is isotypic to the compounds RE{sub 5}(BO{sub 3}){sub 2}F{sub 9} (RE = Er, Yb). Tm{sub 5}(BO{sub 3}){sub 2}F{sub 9} crystallizes in the space group C2/c (Z = 4) with the parameters a = 2030.9(4), b = 606.2(2), c = 822.6(2) pm, {beta} = 100.5(1) , V = 995.7(3) A{sup 3}, R{sub 1} = 0.0341, and wR{sub 2} = 0.0724 (all data). The structure is composed of isolated BO{sub 3} groups, ninefold coordinated thulium cations, and fluoride anions. Infrared and Raman spectroscopic data of Tm{sub 5}(BO{sub 3}){sub 2}F{sub 9} are compared to the data of RE{sub 5}(BO{sub 3}){sub 2}F{sub 9} (RE = Er, Yb). (orig.)

  9. 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.

  10. Mechanisms for electrochemical performance enhancement by the salt-type electrolyte additive, lithium difluoro(oxalato)borate, in high-voltage lithium-ion batteries

    Science.gov (United States)

    Cha, Jiho; Han, Jung-Gu; Hwang, Jaeseong; Cho, Jaephil; Choi, Nam-Soon

    2017-07-01

    Lithium difluoro(oxalato)borate (LiDFOB) with one oxalate moiety bonded to a central boron core was employed as a salt-type additive to enhance the interfacial stabilities of high-voltage Li-rich cathodes and graphite anodes. Our investigation revealed that the LiDFOB additive modified the surface film on the electrodes and effectively restrained degradation of the cycling performance of the electrodes. Investigation of the surface chemistries of the electrodes confirmed that LiDFOB produces a LiF-less surface film on the Li-rich cathode and a LiF-rich surface film on the graphite anode. Moreover, the use of 1% LiDFOB drastically improved the rate capabilities of Li-rich cathodes and graphite anodes. Within 100 cycles at a rate of C/2 at 25 °C, only 45.8% of the initial discharge capacity of a high-voltage Li-rich/graphite full cell was delivered in the baseline electrolyte, while the LiDFOB-containing electrolyte retained 82.7%.

  11. Intense white light luminescent Dy3+ doped lithium borate glasses for W-LED: A correlation between physical, thermal, structural and optical properties

    Science.gov (United States)

    Pawar, P. P.; Munishwar, S. R.; Gedam, R. S.

    2017-02-01

    In this article the physical, thermal structural and optical properties of Dy3+ doped lithium borate glasses have been studied for white LED application. The emission spectra shows two intense emission bands at around 483 nm and 574 nm corresponds to the 4F9/2 → 6H15/2 and 4F9/2 → 6H13/2 transitions along with one feeble band at 663 nm corresponds to 4F9/2 → 6H11/2 transition. The average lifetime of Dy3+ were found to be about 2.95 and 4.94 ns for blue and yellow emission bands respectively. CIE chromaticity diagram shows glass LBD-4 containing 0.5 mol% Dy2O3 with colour co-ordinates x = 0.33 and y = 0.37 have highest emission intensity. These glasses having emission in the white region and thus can be used for bright white LED's and modern white LED bulbs.

  12. Study on visible luminescence of the Tm 3 + : 1D 2 → 3 F 4 emission state in lead borate titanate aluminumfluoride glasses

    Science.gov (United States)

    Suhasini, T.; Jamalaiah, B. C.; Sasikala, T.; Reddy, G. V. Lokeswara; Moorthy, L. Rama

    2012-03-01

    This paper reports the visible luminescence properties of 1D 2 state of Tm 3 + -doped lead borate titanate aluminumfluoride (LBTAFTm) glasses. The absorption and luminescence was analyzed within the frame work of Judd-Ofelt model. The reliability of J-O intensity parameters obtained from the experimental oscillator strengths have satisfactorily been correlated with the calculated oscillator strengths with small r.m.s deviation of ± 0.12 × 10 -6 by the least square fit analysis. Upon 359 nm excitation, the luminescence spectra show only one emission band at 458 nm (blue) corresponding to the 1D 2 → 3 F 4 transition in the spectral region 400-500 nm. No luminescence quenching has been observed with the increase of Tm 3 + concentration. The decay profiles of the 1D 2 level have shown single-exponential nature for all the concentrations and the decay times were found to decrease with the increase of concentration. The stimulated emission cross-section ( σe) for the observed emission transition has also been computed. The large quantum efficiency (η) of the 1D 2 level suggests the utility of LBTAFTm glass as a potential host for optical device applications at 458 nm emission wavelength.

  13. Luminescence properties of Er3+ ions doped bismuth borate glasses for 1.53 \\xB5m broadband optical amplifiers

    Science.gov (United States)

    Mariyappan, M.; Suthanthirakumar, P.; Arunkumar, S.; Marimuthu, K.

    2017-05-01

    A new series of Er3+ ions doped bismuth borate glasses were prepared with the composition (40—x)B2O3 + 20Bi2O3+20Na2O+20CaF2+xEr2O3 (where x= 0.1, 0.25, 0.5, 1 and 2 in wt%). The spectroscopic behaviors of the titled glasses have been examined through absorption, luminescence and decay spectral analysis. Luminescence spectra along with the JO intensity parameters have been used to determine the various radiative properties like transition probability (A), stimulated emission cross-section (σp), lifetimes (τcal, τexp), branching ratios (βR) and effective bandwidth (Δλeff) for the 4S3/2 →4I15/2 and 4I13/2→4I15/2 emission transitions and the results were discussed and reported. By employing the McCumbar theory, absorption and emission cross-sections for the 4I13/2→4I15/2 transition (1.53 μm) were calculated for all the titled glasses. The decay curves of the 4I13/2 level have been measured and the fall in lifetime value with the increase in Er3+ ion content have been studied through the energy transfer process takes place between the nearby Er3+ ions.

  14. Brain Damage from Soman-Induced Seizures Is Greatly Exacerbated by Dimethyl sulfoxide (DMSO): Modest Neuroprotection by 2-Aminoethyl diphenylborinate (2- APB), a Transient Receptor Potential Channel Inhibitor and Inositol 1,4,5-triphosphate Receptor Antagonist

    Science.gov (United States)

    2008-03-04

    subcutaneous (s.c.) xylocaine was administered for local analgesia . Placement of screw electrodes was performed in accordance with the procedure... dental cement. On the morning of the fifth or sixth day following surgeries, electrode-implanted animals were connected to an ECoG recording

  15. 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.)

  16. 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.

  17. Borate-aided anion exchange high-performance liquid chromatography of uridine diphosphate-sugars in brain, heart, adipose and liver tissues.

    Science.gov (United States)

    Oikari, Sanna; Venäläinen, Tuula; Tammi, Markku

    2014-01-03

    In this paper we describe a method optimized for the purification of uridine diphosphate (UDP)-sugars from liver, adipose tissue, brain, and heart, with highly reproducible up to 85% recoveries. Rapid tissue homogenization in cold ethanol, lipid removal by butanol extraction, and purification with a graphitized carbon column resulted in isolation of picomolar quantities of the UDP-sugars from 10 to 30mg of tissue. The UDP-sugars were baseline separated from each other, and from all major nucleotides using a CarboPac PA1 anion exchange column eluted with a gradient of acetate and borate buffers. The extraction and purification protocol produced samples with few unidentified peaks. UDP-N-acetylglucosamine was a dominant UDP-sugar in all the rat tissues studied. However, brain and adipose tissue showed high UDP-glucose levels, equal to that of UDP-N-acetylglucosamine. The UDP-N-acetylglucosamine showed 2.3-2.7 times higher levels than UDP-N-acetylgalactosamine in all tissues, and about the same ratio was found between UDP-glucose and UDP-galactose in adipose tissue and brain (2.6 and 2.8, respectively). Interestingly, the UDP-glucose/UDP-galactose ratio was markedly lower in liver (1.1) and heart (1.7). The UDP-N-acetylglucosamine/UDP-glucuronic acid ratio was also constant, between 9.7 and 7.7, except in liver with the ratio as low as 1.8. The distinct UDP-glucose/galactose ratio, and the abundance of UDP-glucuronic acid may reflect the specific role of liver in glycogen synthesis, and metabolism of hormones and xenobiotics, respectively, using these UDP-sugars as substrates.

  18. New Dihydro OO'Bis(Salicylidene 2,2' Aminobenzothiazolyl Borate Complexes: Kinetic and Voltammetric Studies of Dimethyltin Copper Complex with Guanine, Adenine, and Calf Thymus DNA

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available The newly synthesized ligand, dihydro OO'bis(salicylidene 2,2' aminobenzothiazolyl borate (2, was derived from the reaction of Schiff base of 2-aminobenzothiazole and salicylaldehyde with KBH 4 . Cu II (3 and Zn II (4 complexes of (2 were synthesized and further metallated with dimethyltindichloride to yield heterobimetallic complexes (5 and (6. All complexes have been thoroughly characterized by elemental analysis, and IR, NMR, EPR, and UV-Vis spectroscopy and conductance measurements. The spectroscopic data support square planar environment around the Cu II atom, while the Sn IV atom acquires pentacoordinate geometry. The interaction of complex (5 with guanine, adenine, and calf thymus DNA was studied by spectrophotometric, electrochemical, and kinetic methods. The absorption spectra of complex (5 exhibit a remarkable "hyperchromic effect" in the presence of guanine and calf thymus DNA. Indicative of strong binding of the complex to calf thymus DNA preferentially binds through N 7 position of guanine base, while the adenine shows binding to a lesser extent. The kinetic data were obtained from the rate constants, k obs , values under pseudo-first-order conditions. Cyclic voltammetry was employed to study the interaction of complex (5 with guanine, adenine, and calf thymus DNA. The CV of complex (5 in the absence and in the presence of guanine and calf thymus DNA altered drastically, with a positive shift in formal peak potential E pa and E pc values and a significant increase in peak current. The positive shift in formal potentials with increase in peak current favours strong interaction of complex (5 with calf thymus DNA. The net shift in E 1/2 has been used to estimate the ratio of equilibrium constants for the binding of Cu(II and Cu(I complexes to calf thymus DNA.

  19. New Dihydro OO'Bis(Salicylidene) 2,2' Aminobenzothiazolyl Borate Complexes: Kinetic and Voltammetric Studies of Dimethyltin Copper Complex with Guanine, Adenine, and Calf Thymus DNA.

    Science.gov (United States)

    Arjmand, Farukh; Mohani, Bhawana; Parveen, Shamima

    2006-01-01

    The newly synthesized ligand, dihydro OO'bis(salicylidene) 2,2' aminobenzothiazolyl borate (2), was derived from the reaction of Schiff base of 2-aminobenzothiazole and salicylaldehyde with KBH(4). Cu(II) (3) and Zn(II) (4) complexes of (2) were synthesized and further metallated with dimethyltindichloride to yield heterobimetallic complexes (5) and (6). All complexes have been thoroughly characterized by elemental analysis, and IR, NMR, EPR, and UV-Vis spectroscopy and conductance measurements. The spectroscopic data support square planar environment around the Cu(II) atom, while the Sn(IV) atom acquires pentacoordinate geometry. The interaction of complex (5) with guanine, adenine, and calf thymus DNA was studied by spectrophotometric, electrochemical, and kinetic methods. The absorption spectra of complex (5) exhibit a remarkable "hyperchromic effect" in the presence of guanine and calf thymus DNA. Indicative of strong binding of the complex to calf thymus DNA preferentially binds through N(7) position of guanine base, while the adenine shows binding to a lesser extent. The kinetic data were obtained from the rate constants, k(obs), values under pseudo-first-order conditions. Cyclic voltammetry was employed to study the interaction of complex (5) with guanine, adenine, and calf thymus DNA. The CV of complex (5) in the absence and in the presence of guanine and calf thymus DNA altered drastically, with a positive shift in formal peak potential E(pa) and E(pc) values and a significant increase in peak current. The positive shift in formal potentials with increase in peak current favours strong interaction of complex (5) with calf thymus DNA. The net shift in E(1/2) has been used to estimate the ratio of equilibrium constants for the binding of Cu(II) and Cu(I) complexes to calf thymus DNA.

  20. Spectral properties and dynamics of luminescent states of Pr{sup 3+} and Tm{sup 3+} in lead borate glasses modified by PbF{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Dominiak-Dzik, G. [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, ul. Okolna 2, 50-950 Wroclaw (Poland)]. E-mail: G.Dominiak-Dzik@int.pan.wroc.pl; Ryba-Romanowski, W. [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, ul. Okolna 2, 50-950 Wroclaw (Poland); Pisarska, J. [Department of Materials Science, Silesian University of Technology, 40-019 Katowice (Poland); Pisarski, W.A. [Institute of Materials Science, University of Silesia, 40-007 Katowice (Poland)

    2007-01-15

    A heavy metal oxide borate glass with composition (70-x)PbO-18B{sub 2}O{sub 3}-6Al{sub 2}O{sub 3}-3WO{sub 3} (wt%) was modified by variable content of PbF{sub 2} (x=9, 36 and 72wt%) and doped with 1wt% of Pr{sup 3+} or Tm{sup 3+} ions. The influence of the PbF{sub 2} content on optical properties and luminescence dynamics has been observed through the variation of an effective line width of {sup 1}D{sub 2}->{sup 3}H{sub 4} and {sup 1}G{sub 4}->{sup 3}F{sub 4} emissions as well as the {sup 1}D{sub 2} and {sup 1}G{sub 4} lifetimes of Pr{sup 3+} and Tm{sup 3+}, respectively. It was observed that the increase of PbF{sub 2} content leads to narrowing of the {sup 1}D{sub 2}->{sup 3}H{sub 4} band from 680 to 590cm{sup -1}. This effect was not observed for the {sup 1}G{sub 4}->{sup 3}F{sub 4} thulium emission. The variation of luminescence kinetics was observed both for Pr{sup 3+}- and Tm{sup 3+}-doped samples; the increase of the PbF{sub 2} content has changed the {sup 1}D{sub 2} lifetime from 13.8 to 16.5{mu}s and from 34 to 43{mu}s for the {sup 1}G{sub 4} level.

  1. 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.

  2. Spectral assignments and NMR parameter-structure relationships in borates using high-resolution 11B NMR and density functional theory.

    Science.gov (United States)

    Alderman, Oliver L G; Iuga, Dinu; Howes, Andrew P; Pike, Kevin J; Holland, Diane; Dupree, Ray

    2013-06-07

    High-resolution, solid-state (11)B NMR spectra have been obtained at high magnetic fields for a range of polycrystalline borates using double-rotation (DOR), multiple-quantum magic angle spinning and isotopic dilution. DOR linewidths can be less than 0.2 ppm in isotopically diluted samples, allowing highly accurate values for the isotropic chemical shift, δiso, and electric field gradient to be obtained. The experimental values are used as a test of density functional calculations using both projector augmented wave based CASTEP and WIEN2k. The CASTEP calculations of δiso are generally in very good agreement with experiment, having r.m.s. deviation 0.40 ppm. WIEN2k calculations of electric field gradient magnitude, CQ, and asymmetry, η, are also in excellent agreement with experiment, with r.m.s. deviations 0.038 MHz and 0.042 respectively. However, whilst CASTEP gives a similar deviation for η (0.043) it overestimates CQ by ∼15%. After scaling of the calculated electric field gradient by 0.842 the deviation in CQ is practically identical to that of the WIEN2k calculations. The spectral assignments that follow from the experimental and computational results allow identification of correlations between δiso and (a) the average B-O-B bond angle, θ[combining overline], for both three and four coordinated boron, giving δiso(B(III)) = (185.1 -θ[combining overline])/3.42 ppm and δiso(B(IV)) = (130.2 -θ[combining overline])/5.31 ppm; and (b) the ring-site T(3) unit trigonal planar angular deviation, Stri, giving δiso(T(3)(ring)) = (1.642 × 10(-2)-Stri)/(8.339 × 10(-4)) ppm.

  3. 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.

  4. A chiral alkyltris(pyrazolyl)borate ligand: synthesis of [(Ipc)B(pz)3Mn(CO)3] and [(Ipc)B(pz)3Ru(p-cymene)]PF6 (Ipc = Isopinocampheyl).

    Science.gov (United States)

    Bailey, Philip J; Pinho, Pedro; Parsons, Simon

    2003-12-29

    The application of the reagent (Ipc)BCl(2) (Ipc = isopinocampheyl) in the synthesis of a new tris(pyrazolyl)borate ligand having an Ipc substituent on boron is described. The sodium salt is a convenient precursor for the preparation of the complexes [(Ipc)tris(pyrazolyl)borato]tricarbonylmanganese and [[(Ipc)tris(pyrazolyl)borato](p-cymene)ruthenium](+), whose X-ray crystal structures are reported. While little distortion of the B(pz)(3)M unit is observed in these complexes, steric interaction between the Ipc group and the 3-positions of the pyrazolyl rings is noted to lead to distortion of the angles around the B-C bond.

  5. 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.

  6. 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.

  7. XRD and FTIR studies the effect of heat treatment and doping the transition metal oxide on LiNbO3 and LiNb3O8 nano-crystallite phases in lithium borate glass system.

    Science.gov (United States)

    Kashif, Ismail; Soliman, Ashia A; Sakr, Elham M; Ratep, Asmaa

    2013-09-01

    Glasses of various compositions in the system 90 Li2B4O7-10 Nb2O5 mixed with T.M ions (where T.M is the transition metal) were prepared by quenching technique. Heat-treatment of the parent glasses was performed at 540, 570 and 620 °C, for 5 and 16 h. The glass structure evolution during the controlled crystallization was examined by XRD and FT-IR spectroscopy analysis. The crystalline phases present in the glass ceramics were identified via X-ray diffraction as a function of heat treatment. The FT-IR data propose for these glasses and heat-treated glass network structures mainly built by: di-, tri-, tetra-, penta-and ortho-borate groups. It was found that the quantitative evolution of these various borate species in the glass structures is influenced by the transition metal. A detailed discussion relating to the N4 evolution with the T.M content was made.

  8. Oxonium ions substituting cesium ions in the structure of the new high-pressure borate HP-Cs(1-x)(H(3)O)(x)B(3)O(5) (x=0.5-0.7).

    Science.gov (United States)

    Sohr, Gerhard; Neumair, Stephanie C; Heymann, Gunter; Wurst, Klaus; Schmedt auf der Günne, Jörn; Huppertz, Hubert

    2014-04-07

    The new high-pressure borate HP-Cs1-x (H3 O)x B3 O5 (x=0.5-0.7) was synthesized under high-pressure/high-temperature conditions of 6 GPa/900 °C in a Walker-type multianvil apparatus. The compound crystallizes in the monoclinic space group C2/c (Z=8) with the parameters a=1000.6(2), b=887.8(2), c=926.3(2) pm, β=103.1(1)°, V=0.8016(3) nm(3) , R1=0.0452, and wR2=0.0721 (all data). The boron-oxygen network is analogous to those of the compounds HP-MB3 O5 , (M=K, Rb) and exhibits all three structural motifs of borates-BO3 groups, corner-sharing BO4 tetrahedra, and edge-sharing BO4 tetrahedra-at the same time. Channels inside the boron-oxygen framework contain the cesium and oxonium ions, which are disordered on a specific site. Estimating the amount of hydrogen by solid-state NMR spectroscopy and X-ray diffraction led to the composition HP-Cs1-x (H3 O)x B3 O5 (x=0.5-0.7), which implies a nonzero phase width.

  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. 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.

  12. 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-).)

  13. 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

  14. Optical absorption, luminescence, and energy transfer processes studies for Dy3+/Tb3+-codoped borate glasses for solid-state lighting applications

    Science.gov (United States)

    Lakshminarayana, G.; Kaky, Kawa M.; Baki, S. O.; Lira, A.; Caldiño, U.; Kityk, I. V.; Mahdi, M. A.

    2017-10-01

    By using melt quenching technique, good optical quality singly doped Dy3+ or Tb3+ and Dy3+/Tb3+-codoped borate glasses were synthesized and studied by optical absorption, excitation, emission and decay lifetimes curve analysis. Following the absorption spectrum, the evaluated Judd-Ofelt (J-O) intensity parameters (Ωλ (λ = 2, 4 and 6)) were used to calculate the transition probability (AR), the branching ratio (βR), and the radiative lifetime (τR) for different luminescent transitions such as 4I15/2 → 6H15/2, 4F9/2 → 6H15/2, 4F9/2 → 6H13/2, 4F9/2 → 6H11/2 and 4F9/2 → 6H9/2,6F11/2 for the 0.5 mol % singly Dy3+-doped glass. The βR calculated (65%) indicates that for lasing applications, 4F9/2 → 6H13/2 emission transition is highly suitable. For all the Dy3+/Tb3+-codoped glasses, Tb3+: 5D3→7F6 emission decay lifetime curves are found to be non-exponential in nature for different concentrations of Dy3+ codoping. Using the Inokuti-Hirayama model, these nonexponential decay curves were analyzed to identify the nature of the energy transfer (ET) processes and here the electric dipole-dipole interaction is dominant for the ET. Based on the excitation and emission spectra and decay lifetimes curve analysis, the cross relaxation and ET processes between Dy3+ and Tb3+ were confirmed. For the 0.5 mol % Tb3+ and 2.0 mol % Dy3+-codoped glass, the evaluated Tb3+→Dy3+ ET efficiency (η) is found to be 45% under 369 nm excitation. Further, for Tb3+/Dy3+ -codoped glasses, an enhancement of Tb3+ green emission is observed up to 1.5 mol % Dy3+ codoping, and this is due to the non-radiative resonant ET from Dy3+ to Tb3+ upon 395 nm excitation. For singly 0.5 mol % Dy3+ or 0.5 mol % Tb3+-doped glass, the calculated color coordinates (x,y) and correlated color temperatures (CCT) represent the neutral white or warm white light regions, whereas Dy3+/Tb3+-codoped glasses (x,y) and CCT values fall in the yellowish green region with respect to the different Dy3

  15. Luminescence de l'europium divalent dans les borates doubles BaLnB9O16(Ln=La, Gd, Y) et de l'europium trivalent dans les phosphates d'Yttrium et de gadolinium en vue d'application à la visualisation

    OpenAIRE

    Cong Tuan, Dinh

    2000-01-01

    En vue d'application à l'éclairage ou dans les dispositifs de visualisation à plama, on a étudié la luminescence de l'ion Eu2+ dans les borates BaLnB9O16 (Ln = La, Ce, Gd, Y) et de l'ion Eu3+ dans les diverses phases des systèmes Gd2O3-P2O5 et Y2O3-P2O5. Des informations sur les structures des réseaux-hôtes lorsqu'elles étaient inconnues, ont pu être obtenues par diffraction X et spectroscopie Raman. Pour Ln = Y, Gd, les borates BaLnB9O16:Eu2+ présentent une émission dans le bleu stable...; n...

  16. Vitrovariation et régénération par embryogenèse somatique à partir d'embryons mûrs de blé tendre (Triticum aestivum L. var. 'Nesma' 149 : effet du borate de sodium, de la fragmentation et du scutellum

    Directory of Open Access Journals (Sweden)

    Karim, R.

    2011-01-01

    Full Text Available Vitrovariation and regeneration by somatic embryogenesis from mature embryos of common wheat (Triticum aestivum L. Var. 'Nesma' 149: effect of the borate of sodium, the fragmentation and the scutellum. The combined effects of the scutellum, the fragmentation and sodium borate, on the embryogenic capacity of ripe zygotic embryos of common wheat (Triticum aestivum L. var. 'Nesma' 149 were studied. The morphological characters and yield of the regenerated plants differ from control plants and indicate somaclonales variations. The mediums containing borax (0.75 g.l-1 and comprising explants resulting from the longitudinal fragmentation of the zygotic embryos with scutellum, initiated high percentages of embryogenic callus and of regeneration over one long period of culture, with large size somatic embryos as well as a weak somaclonale variation and one very low necrosis of callus. Whereas the mediums containing less or no borax and explants resulting from transversely cut zygotic embryos and without scutellum show opposite results.

  17. 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

  18. 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...

  19. 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.

  20. Synthesis of aluminium borate-boron oxide and binary titanium-boron and zirconium-boron oxides from metal alkoxides and (MeO)3B3O3 in non-aqueous solvents.

    Science.gov (United States)

    Beckett, Michael A; Rugen-Hankey, Martin P; Timmis, James L; Varma, K Sukumar

    2008-03-21

    The reaction of metal alkoxides M(OR)4 (M = Ti, Zr; R = organyl) with (MeO)3B3O3 (1 : 0.67) in dry propan-2-one at room temperature led to gels which when dried and calcined in air for 24 h at 500-1000 degrees C afforded bi-phased mixed-oxide materials formulated as 4TiO2 x 3B2O3 and ZrO2 x B2O3 in high ceramic yields and purity; the B2O3 phases of these materials were amorphous. The materials remained amorphous upon calcination at lower temperatures. The TiO2 phase of the 4TiO2 x 3B2O3 was crystalline when calcined at higher temperatures with either anatase (600 degrees C) or rutile (>800 degrees C) being obtained. The ZrO2 phase of the ZrO2 x B2O3 was crystalline when calcined at higher temperatures and was obtained as a metastable tetragonal phase (800 degrees C). In a similar reaction, Al(O(i)Pr)3 (2 : 1) gave a bi-phased aluminium borate-boron oxide (Al18B4O(33).7B2O3) after calcination at >700 degrees C. The dried gels and oxide materials were all characterized by elemental analysis, TGA-DSC, and powder XRD.