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Sample records for nickel-zinc phosphate glasses

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

    International Nuclear Information System (INIS)

    Fernandes, Kirlene Salgado; Alvarenga, Evandro de Azevedo; Lins, Vanessa de Freitas Cunha

    2011-01-01

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

  2. Spectroscopic studies of copper doped alkaline earth lead zinc phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Sastry, S. Sreehari, E-mail: sreeharisastry@yahoo.com [Department of Physics, Acharya Nagarjuna University, Nagarjunanagar 522510 (India); Rao, B. Rupa Venkateswara [Department of Physics, Acharya Nagarjuna University, Nagarjunanagar 522510 (India); Department of Physics, V.R. Siddhartha Engineering College, Vijayawada 52007 (India)

    2014-02-01

    In this paper spectroscopic investigation of Cu{sup 2+} doped alkaline earth lead zinc phosphate glasses was done through the spectroscopic techniques like X-ray diffraction, Ultra Violet (UV) absorption Spectroscopy, Electron Paramagnetic Resonance (EPR – X band), Fourier Transform Infra Red (FTIR) and Raman Spectroscopy. Alkaline earth lead zinc phosphate glasses containing 0.1% copper oxide (CuO) were prepared by the melt quenching technique. Spectroscopic studies indicated that there is a greater possibility for the copper ions to exist in Cu{sup 2+} state in these glasses. The optical absorption spectra indicated that the absorption peak of Cu{sup 2+} is a function of composition. The maxima absorption peak was reported at 862 nm for strontium lead zinc phosphate glass. Bonding parameters were calculated for the optical and EPR data. All these spectral results indicated clearly that there are certain structural changes in the present glass system with different alkaline earth contents. The IR and Raman spectra noticed the breaking of the P–O–P bonds and creating more number of new P–O–Cu bonds.

  3. Spectroscopic studies of copper doped alkaline earth lead zinc phosphate glasses

    International Nuclear Information System (INIS)

    Sastry, S. Sreehari; Rao, B. Rupa Venkateswara

    2014-01-01

    In this paper spectroscopic investigation of Cu 2+ doped alkaline earth lead zinc phosphate glasses was done through the spectroscopic techniques like X-ray diffraction, Ultra Violet (UV) absorption Spectroscopy, Electron Paramagnetic Resonance (EPR – X band), Fourier Transform Infra Red (FTIR) and Raman Spectroscopy. Alkaline earth lead zinc phosphate glasses containing 0.1% copper oxide (CuO) were prepared by the melt quenching technique. Spectroscopic studies indicated that there is a greater possibility for the copper ions to exist in Cu 2+ state in these glasses. The optical absorption spectra indicated that the absorption peak of Cu 2+ is a function of composition. The maxima absorption peak was reported at 862 nm for strontium lead zinc phosphate glass. Bonding parameters were calculated for the optical and EPR data. All these spectral results indicated clearly that there are certain structural changes in the present glass system with different alkaline earth contents. The IR and Raman spectra noticed the breaking of the P–O–P bonds and creating more number of new P–O–Cu bonds

  4. Femtosecond laser writing of waveguides in zinc phosphate glasses [Invited

    NARCIS (Netherlands)

    Fletcher, L.B.; Witcher, J.J.; Troy, N.; Reis, S.T.; Brow, R.K.; Martinez Vazquez, R.; Osellame, R.; Krol, D.M.

    2011-01-01

    We have studied the relationship between the initial glass composition and the structural changes associated with laser-induced refractive index modification in a series of Er-Yb doped and undoped zinc phosphate glasses. White light microscopy and waveguide experiments are used together with Raman

  5. Zinc phosphate conversion coatings

    Science.gov (United States)

    Sugama, Toshifumi

    1997-01-01

    Zinc phosphate conversion coatings for producing metals which exhibit enhanced corrosion prevention characteristics are prepared by the addition of a transition-metal-compound promoter comprising a manganese, iron, cobalt, nickel, or copper compound and an electrolyte such as polyacrylic acid, polymethacrylic acid, polyitaconic acid and poly-L-glutamic acid to a phosphating solution. These coatings are further improved by the incorporation of Fe ions. Thermal treatment of zinc phosphate coatings to generate .alpha.-phase anhydrous zinc phosphate improves the corrosion prevention qualities of the resulting coated metal.

  6. Investigation of alternative phosphating treatments for nickel and hexavalent chromium elimination

    International Nuclear Information System (INIS)

    Jazbinsek, Luiz Antonio Rossi

    2014-01-01

    The phosphating processes are widely used in industry as surface treatments for metals, especially for low thickness plates, improving the adhesion between the metallic surface and the paint coating, and increasing the durability of paint systems against corrosion attacks. The tricationic phosphates containing zinc, nickel and manganese are commonly applied on steel. There is much discussion about the replacement of nickel by another element in order to have an environmentally friendly phosphating process. Niobium as a replacement for nickel has been evaluated. The most significant environmental impacts of phosphating processes are related to the presence of nickel and hexavalent chromium used in the process, this last as a passivation treatment. Nickel and hexavalent chromium are harmful to human and environment leading to contamination of water and soil. In the present study phosphate layers containing zinc, manganese and niobium have been evaluated and characterized on galvanized steel, and the results were compared with phosphates containing zinc, manganese and nickel, or a bicationic phosphate layer with zinc and manganese. Although the use of hexavalent chromium is not recommended worldwide, it is still used in processes for sealing the porosity of phosphate layers. This element is carcinogenic and has been associated with various diseases. Due to the passivation characteristics of niobium, this study also evaluated the tricationic bath containing niobium ammonium oxalate as a passivation treatment. The results showed that it could act as a replacement for the hexavalent chromium. The results of the present study showed that formulations containing niobium are potential replacements for hexavalent chromium and similar corrosion protection was obtained for the phosphate containing nickel or that with niobium. The morphology observed by scanning electron microscopy, gravimetric tests, porosity and adhesion evaluation results indicated that the phosphate

  7. A comparative study of retentive strengths of zinc phosphate, polycarboxylate and glass ionomer cements with stainless steel crowns--an in vitro study.

    Science.gov (United States)

    Reddy, R; Basappa, N; Reddy, V V

    1998-03-01

    This study was conducted on 30 extracted human primary molars to assess the retentive strengths of zinc phosphate, polycarboxylate and glass ionomer cements. The teeth were embedded in resin blocks and were randomly divided into 3 groups of 10 each. The occlusal surfaces of all teeth were reduced uniformly by 1.0 to 1.5 mm. All mesial, distal undercuts were removed and sharp angles rounded. This was followed by cementing pretrimmed and precontoured stainless steel crowns on each tooth with hand pressure and storing in artificial saliva at 37 degrees C for 24 hours. Retentive strength was tested using Instron Universal Testing Machine. The load was applied starting from a zero reading and gradually increased until the cemented stainless steel crowns showed signs of movement and then the readings were recorded. It was found that retentive strengths of zinc phosphate and glass ionomer cements were statistically better (P cement. Negligible difference (0. 59 kg/cm2) was however observed between zinc phosphate and glass ionomer cements.

  8. Concentration effect on the spectroscopic behavior of Tb3+ ions in zinc phosphate glasses

    International Nuclear Information System (INIS)

    Kesavulu, C.R.; Almeida Silva, Anielle Christine; Dousti, M.R.; Dantas, Noelio Oliveira; Camargo, A.S.S. de; Catunda, Tomaz

    2015-01-01

    Zinc phosphate glasses (PZABPTb) in the compositional system: P 2 O 5 –ZnO–Al 2 O 3 –BaO–PbO doped with variable Tb 3+ concentrations (1–5 wt% Tb 2 O 3 ) were prepared and characterized through absorption, excitation, emission and intensity decay rate measurements. The Judd–Ofelt model has been adopted to evaluate the radiative properties of the 5 D 4 → 7 F 6–3 emission transitions. The effect of Tb 3+ ion concentration on the emissions from the 5 D 3,4 excited levels is discussed in detail. Analysis of the intensity decay curves corresponding to blue and green emissions from levels 5 D 3 and 5 D 4 , respectively, allowed determination of effective lifetimes, which confirmed the Tb 3+ ion concentration quenching of the blue emission in these glasses. The decay curves for the 5 D 3 level are found to be non-exponential in nature for all the studied concentrations due to ion–ion energy transfer through cross-relaxation. In an attempt to identify the origin of the energy transfer mechanism, the decay curves were well fitted to the Inokuti–Hirayama model for S=6, which indicates that the energy transfer process is of dipole–dipole type. The optical band gap energy (E opt ) has been evaluated taking into account the ultraviolet edge of absorption spectra. - Highlights: • Tb 3+ -doped zinc phosphate glasses have been prepared by melt quenching technique. • Spectroscopic parameters were evaluated using the Judd–Ofelt theory. • Effects of Tb 3+ concentration on luminescence of the glasses were studied. • Strong intense laser transition for Tb 3+ ion in PZABPTb glasses is 5 D 4 → 7 F 5 (0.54 μm). • PZABPTb glasses could be used in the development of green color display devices and solid state visible lasers

  9. A comparative study of retentive strengths of zinc phosphate, polycarboxylate and glass ionomer cements with stainless steel crowns - an in vitro study.

    Science.gov (United States)

    Raghunath Reddy, M H; Subba Reddy, V V; Basappa, N

    2010-01-01

    An in vitro study was conducted to compare the retentive strengths of zinc phosphate, polycarboxylate and glass ionomer cements using Instron universal testing machine. Thirty preformed and pretrimmed stainless steel crowns were used for cementation on 30 extracted human primary molars which were divided into three groups of 10 teeth in each group. Then the teeth were stored in artificial saliva and incubated at 37°C for 24 h. A load was applied on to the crown and was gradually increased till the crown showed dislodgement, and then the readings were recorded using Instron recorder and analyzed for statistical significance. The surface area of crown was measured by graphical method. The retentive strength was expressed in terms of kg/cm 2 , which was calculated by the equation load divided by area. Retentive strengths of zinc phosphate (ranged from a minimum of 16.93 to amaximum of 28.13 kg/cm 2 with mean of 21.28 kg/cm 2 ) and glass ionomer cement (minimum of 13.69 - 28.15 kg/cm 2 with mean of 20.69 kg/cm 2 ) were greater than that of polycarboxylate cement (minimum of 13.26 - 22.69 kg/cm 2 with mean of 16.79 kg/cm 2 ). Negligible difference (0.59 kg/cm 2 ) of retentive strength was observed between zinc phosphate (21.28 kg/cm 2 ) and glass ionomer cements (20.69 kg/cm 2 ). Glass ionomer cements can be recommended for cementation of stainless steel crowns because of its advantages and the retentive strength was almost similar to that of zinc phosphate cement.

  10. A comparative study of retentive strengths of zinc phosphate, polycarboxylate and glass ionomer cements with stainless steel crowns - An in vitro study

    Directory of Open Access Journals (Sweden)

    Raghunath Reddy M

    2010-01-01

    Full Text Available An in vitro study was conducted to compare the retentive strengths of zinc phosphate, polycarboxylate and glass ionomer cements using Instron universal testing machine. Thirty preformed and pretrimmed stainless steel crowns were used for cementation on 30 extracted human primary molars which were divided into three groups of 10 teeth in each group. Then the teeth were stored in artificial saliva and incubated at 37°C for 24 h. A load was applied on to the crown and was gradually increased till the crown showed dislodgement, and then the readings were recorded using Instron recorder and analyzed for statistical significance. The surface area of crown was measured by graphical method. The retentive strength was expressed in terms of kg/cm 2 , which was calculated by the equation load divided by area. Retentive strengths of zinc phosphate (ranged from a minimum of 16.93 to amaximum of 28.13 kg/cm 2 with mean of 21.28 kg/cm 2 and glass ionomer cement (minimum of 13.69 - 28.15 kg/cm 2 with mean of 20.69 kg/cm 2 were greater than that of polycarboxylate cement (minimum of 13.26 - 22.69 kg/cm 2 with mean of 16.79 kg/cm 2 . Negligible difference (0.59 kg/cm 2 of retentive strength was observed between zinc phosphate (21.28 kg/cm 2 and glass ionomer cements (20.69 kg/cm 2 . Glass ionomer cements can be recommended for cementation of stainless steel crowns because of its advantages and the retentive strength was almost similar to that of zinc phosphate cement.

  11. Concentration effect on the spectroscopic behavior of Tb{sup 3+} ions in zinc phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Kesavulu, C.R., E-mail: crkesavulu2005@gmail.com [Instituto de Fisica de São Carlos, Universidade de São Paulo, Avenida Trabalhador Sãocarlense 400, São Carlos, SP (Brazil); Almeida Silva, Anielle Christine [Laboratorio de Novos Materials Isolantes e Semicondutores (LNMIS), Instituto de Física, Universidade Federal de Uberândia, MG (Brazil); Dousti, M.R. [Instituto de Fisica de São Carlos, Universidade de São Paulo, Avenida Trabalhador Sãocarlense 400, São Carlos, SP (Brazil); Dantas, Noelio Oliveira [Laboratorio de Novos Materials Isolantes e Semicondutores (LNMIS), Instituto de Física, Universidade Federal de Uberândia, MG (Brazil); Camargo, A.S.S. de; Catunda, Tomaz [Instituto de Fisica de São Carlos, Universidade de São Paulo, Avenida Trabalhador Sãocarlense 400, São Carlos, SP (Brazil)

    2015-09-15

    Zinc phosphate glasses (PZABPTb) in the compositional system: P{sub 2}O{sub 5}–ZnO–Al{sub 2}O{sub 3}–BaO–PbO doped with variable Tb{sup 3+} concentrations (1–5 wt% Tb{sub 2}O{sub 3}) were prepared and characterized through absorption, excitation, emission and intensity decay rate measurements. The Judd–Ofelt model has been adopted to evaluate the radiative properties of the {sup 5}D{sub 4}→{sup 7}F{sub 6–3} emission transitions. The effect of Tb{sup 3+} ion concentration on the emissions from the {sup 5}D{sub 3,4} excited levels is discussed in detail. Analysis of the intensity decay curves corresponding to blue and green emissions from levels {sup 5}D{sub 3} and {sup 5}D{sub 4}, respectively, allowed determination of effective lifetimes, which confirmed the Tb{sup 3+} ion concentration quenching of the blue emission in these glasses. The decay curves for the {sup 5}D{sub 3} level are found to be non-exponential in nature for all the studied concentrations due to ion–ion energy transfer through cross-relaxation. In an attempt to identify the origin of the energy transfer mechanism, the decay curves were well fitted to the Inokuti–Hirayama model for S=6, which indicates that the energy transfer process is of dipole–dipole type. The optical band gap energy (E{sub opt}) has been evaluated taking into account the ultraviolet edge of absorption spectra. - Highlights: • Tb{sup 3+}-doped zinc phosphate glasses have been prepared by melt quenching technique. • Spectroscopic parameters were evaluated using the Judd–Ofelt theory. • Effects of Tb{sup 3+} concentration on luminescence of the glasses were studied. • Strong intense laser transition for Tb{sup 3+} ion in PZABPTb glasses is {sup 5}D{sub 4}→{sup 7}F{sub 5} (0.54 μm). • PZABPTb glasses could be used in the development of green color display devices and solid state visible lasers.

  12. Influence of silver and copper doping on luminescent properties of zinc-phosphate glasses after x-ray irradiation

    Science.gov (United States)

    Murashov, Alexander A.; Sidorov, Alexander I.; Shakhverdov, Teimur A.; Stolyarchuk, Maxim V.

    2017-11-01

    It is shown, experimentally, that in silver- and copper-containing zinc-phosphate glasses, metal molecular clusters are formed during the glass synthesis. X-ray irradiation of these glasses led to the considerable increase of its luminescence in visible spectral range. This effect is caused by the transformation of the charged metal molecular clusters into the neutral state. Luminescence and excitation spectra of the glass, doped with silver and copper simultaneously, change significantly in comparison with the spectra of glasses doped with one metal. The reason for this can be the formation of hybrid AgnCum molecular clusters. The computer simulation of the structure and optical properties of such clusters by the time-dependent density functional theory method is presented. It is shown that the optimal luminescent material for photonics application, in comparison with other studied materials, is glass, containing hybrid molecular clusters.

  13. Phosphate glasses, containing nitrogen

    International Nuclear Information System (INIS)

    Lisitsyna, E.A.; Khalilev, V.D.; Koryavin, A.A.; Goncharova, L.N.

    1987-01-01

    Possibilities of nitrogen-containing glass synthesis by the introduction into the charge of ammonium salts, as well as aluminium nitride, are studied. Zinc alumoyttrium phosphate glass (mol. %) Zn(PO 3 ) 2 - 4O, Al(PO 3 ) 3 - 3O, Y(PO 3 ) 3 -3O is suggested as a matrix. It is shown that the effect of amide and imide groups on the properties of the glass is less noticeable than the effect of nitride groups. Direct introduction of nitride constituent was realized using AlN, but aluminium introduction was taken into account so that the oxide was subtracted. The attempt to introduce more than 2.5 mass % of nitrogen into initial matrix by aluminium nitride has failed due to repeated restoration of glass with amorphous phosphorus isolation

  14. Electrodeposition of zinc--nickel alloys coatings

    Energy Technology Data Exchange (ETDEWEB)

    Dini, J W; Johnson, H R

    1977-10-01

    One possible substitute for cadmium in some applications is a zinc--nickel alloy deposit. Previous work by others showed that electrodeposited zinc--nickel coatings containing about 85 percent zinc and 15 percent nickel provided noticeably better corrosion resistance than pure zinc. Present work which supports this finding also shows that the corrosion resistance of the alloy deposit compares favorably with cadmium.

  15. Magnetic properties of bioactive glass-ceramics containing nanocrystalline zinc ferrite

    International Nuclear Information System (INIS)

    Singh, Rajendra Kumar; Srinivasan, A.

    2011-01-01

    Glass-ceramics with finely dispersed zinc ferrite (ZnFe 2 O 4 ) nanocrystallites were obtained by heat treatment of x(ZnO,Fe 2 O 3 )(65-x)SiO 2 20(CaO,P 2 O 5 )15Na 2 O (6≤x≤21 mole%) glasses. X-ray diffraction patterns of the glass-ceramic samples revealed the presence of calcium sodium phosphate [NaCaPO 4 ] and zinc ferrite [ZnFe 2 O 4 ] as major crystalline phases. Zinc ferrite present in nanocrystalline form contributes to the magnetic properties of the glass-ceramic samples. Magnetic hysteresis cycles of the glass-ceramic samples were obtained with applied magnetic field sweeps of ±20 kOe and ±500 Oe, in order to evaluate the potential of these glass-ceramics for hyperthermia treatment of cancer. The evolution of magnetic properties in these samples, viz., from a partially paramagnetic to fully ferrimagnetic nature has been explored using magnetometry and X-ray diffraction studies. - Research highlights: → The glass-ceramics contain bone mineral and magnetic phases. → Calcium sodium phosphate and zinc ferrite nanocrystallites have been identified in all the sample. → With an increase in ZnO and Fe2O3 content, magnetic property of samples evolved from partially paramagnetic to fully ferrimagnetic nature. → Large magnetic hysteresis loops have been obtained for samples with high ZnO+Fe2O3 content.

  16. Investigation of alternative phosphating treatments for nickel and hexavalent chromium elimination; Investigacao de tratamentos alternativos de fosfatizacao para eliminacao do niquel e cromo hexavalente

    Energy Technology Data Exchange (ETDEWEB)

    Jazbinsek, Luiz Antonio Rossi

    2014-07-01

    The phosphating processes are widely used in industry as surface treatments for metals, especially for low thickness plates, improving the adhesion between the metallic surface and the paint coating, and increasing the durability of paint systems against corrosion attacks. The tricationic phosphates containing zinc, nickel and manganese are commonly applied on steel. There is much discussion about the replacement of nickel by another element in order to have an environmentally friendly phosphating process. Niobium as a replacement for nickel has been evaluated. The most significant environmental impacts of phosphating processes are related to the presence of nickel and hexavalent chromium used in the process, this last as a passivation treatment. Nickel and hexavalent chromium are harmful to human and environment leading to contamination of water and soil. In the present study phosphate layers containing zinc, manganese and niobium have been evaluated and characterized on galvanized steel, and the results were compared with phosphates containing zinc, manganese and nickel, or a bicationic phosphate layer with zinc and manganese. Although the use of hexavalent chromium is not recommended worldwide, it is still used in processes for sealing the porosity of phosphate layers. This element is carcinogenic and has been associated with various diseases. Due to the passivation characteristics of niobium, this study also evaluated the tricationic bath containing niobium ammonium oxalate as a passivation treatment. The results showed that it could act as a replacement for the hexavalent chromium. The results of the present study showed that formulations containing niobium are potential replacements for hexavalent chromium and similar corrosion protection was obtained for the phosphate containing nickel or that with niobium. The morphology observed by scanning electron microscopy, gravimetric tests, porosity and adhesion evaluation results indicated that the phosphate

  17. Structural and luminescence studies of Ho{sup 3+}-doped zinc-aluminium-sodium-phosphate (ZANP) glasses

    Energy Technology Data Exchange (ETDEWEB)

    Brahmachary, K.; Rajesh, D.; Ratnakaram, Y. C., E-mail: ratnakaramsvu@gmail.com [Department of Physics, Sri Venkateswara University, Tirupati-517502 (India)

    2015-06-24

    Trivalent holmium doped zinc-aluminium-sodium-phosphate (ZANP) glasses were prepared by conventional melt-quenching technique and characterized for their structural and luminescence properties. The amorphous nature, elemental analysis and thermal stability of the glasses were studied by using X-ray diffraction, energy dispersive spectrum and differential scanning calorimetry analysis, respectively. The absorption and fluorescence spectra have been recorded at room temperature. Based on the absorption spectra, the Judd-Ofelt parameters and radiative parameters such as spontaneous transition probabilities (A{sub R}), branching ratios (β{sub R}), radiative lifetimes (τ{sub R}) were calculated and discussed. From the emission spectra emission peak positions (λ{sub P}), effective bandwidths (Δλ{sub eff}) and stimulated emission cross-sections (σ{sub P}) were calculated for the observed emission transitions,{sup 5}S{sub 2} ({sup 5}F{sub 4}→{sup 5}I{sub 8}) and {sup 5}F{sub 5}→{sup 5}I{sub 8} in all the glass samples. The stimulated emission cross-section is higher for ZANPHo10 glass matrix and so it may be useful for laser excitation.

  18. Electronic polarizability, optical basicity and interaction parameter for Nd2O3 doped lithium-zinc-phosphate glasses

    Science.gov (United States)

    Algradee, M. A.; Sultan, M.; Samir, O. M.; Alwany, A. Elwhab B.

    2017-08-01

    The Nd3+-doped lithium-zinc-phosphate glasses were prepared by means of conventional melt quenching method. X-ray diffraction results confirmed the glassy nature of the studied glasses. The physical parameters such as the density, molar volume, ion concentration, polaron radius, inter-ionic distance, field strength and oxygen packing density were calculated using different formulae. The transmittance and reflectance spectra of glasses were recorded in the wavelength range 190-1200 nm. The values of optical band gap and Urbach energy were determined based on Mott-Davis model. The refractive indices for the studied glasses were evaluated from optical band gap values using different methods. The average electronic polarizability of the oxide ions, optical basicity and an interaction parameter were investigated from the calculated values of the refractive index and the optical band gap for the studied glasses. The variations in the different physical and optical properties of glasses with Nd2O3 content were discussed in terms of different parameters such as non-bridging oxygen and different concentrations of Nd cation in glass system.

  19. Ac-conductivity and dielectric response of new zinc-phosphate glass/metal composites

    Energy Technology Data Exchange (ETDEWEB)

    Maaroufi, A., E-mail: maaroufi@fsr.ac.ma [University of Mohammed V, Laboratory of Composite Materials, Polymers and Environment, Department of Chemistry, Faculty of Sciences, P.B. 1014, Rabat-Agdal (Morocco); Oabi, O. [University of Mohammed V, Laboratory of Composite Materials, Polymers and Environment, Department of Chemistry, Faculty of Sciences, P.B. 1014, Rabat-Agdal (Morocco); Lucas, B. [XLIM UMR 7252 – Université de Limoges/CNRS, 123 avenue Albert Thomas, 87060 Limoges Cedex (France)

    2016-07-01

    The ac-conductivity and dielectric response of new composites based on zinc-phosphate glass with composition 45 mol%ZnO–55 mol%P{sub 2}O{sub 5}, filled with metallic powder of nickel (ZP/Ni) were investigated by impedance spectroscopy in the frequency range from 100 Hz to 1 MHz at room temperature. A high percolating jump of seven times has been observed in the conductivity behavior from low volume fraction of filler to the higher fractions, indicating an insulator – semiconductor phase transition. The measured conductivity at higher filler volume fraction is about 10{sup −1} S/cm and is frequency independent, while, the obtained conductivity for low filler volume fraction is around 10{sup −8} S/cm and is frequency dependent. Moreover, the elaborated composites are characterized by high dielectric constants in the range of 10{sup 5} for conductive composites at low frequencies (100 Hz). In addition, the distribution of the relaxation processes was also evaluated. The Debye, Cole-Cole, Davidson–Cole and Havriliak–Negami models in electric modulus formalism were used to model the observed relaxation phenomena in ZP/Ni composites. The observed relaxation phenomena are fairly simulated by Davidson–Cole model, and an account of the interpretation of results is given. - Highlights: • Composites of ZnO-P{sub 2}O{sub 5}/metal were investigated by impedance spectroscopy. • Original ac-conductivity behavior was discovered in ZnO-P{sub 2}O{sub 5}/metal composites. • High dielectric constant is measured in ZnO-P{sub 2}O{sub 5}/metal composites. • Dielectric constant as filler function is well interpreted with percolation theory. • Observed relaxation processes are well described using electric modulus formalism.

  20. Electrodeposition behavior of nickel and nickel-zinc alloys from the zinc chloride-1-ethyl-3-methylimidazolium chloride low temperature molten salt

    International Nuclear Information System (INIS)

    Gou Shiping; Sun, I.-W.

    2008-01-01

    The electrodeposition of nickel and nickel-zinc alloys was investigated at polycrystalline tungsten electrode in the zinc chloride-1-ethyl-3-methylimidazolium chloride molten salt. Although nickel(II) chloride dissolved easily into the pure chloride-rich 1-ethyl-3-methylimidazolium chloride ionic melt, metallic nickel could not be obtained by electrochemical reduction of this solution. The addition of zinc chloride to this solution shifted the reduction of nickel(II) to more positive potential making the electrodeposition of nickel possible. The electrodeposition of nickel, however, requires an overpotential driven nucleation process. Dense and compact nickel deposits with good adherence could be prepared by controlling the deposition potential. X-ray powder diffraction measurements indicated the presence of crystalline nickel deposits. Non-anomalous electrodeposition of nickel-zinc alloys was achieved through the underpotential deposition of zinc on the deposited nickel at a potential more negative than that of the deposition of nickel. X-ray powder diffraction and energy-dispersive spectrometry measurements of the electrodeposits indicated that the composition and the phase types of the nickel-zinc alloys are dependent on the deposition potential. For the Ni-Zn alloy deposits prepared by underpotential deposition of Zn on Ni, the Zn content in the Ni-Zn was always less than 50 atom%

  1. Retentive [correction of Preventive] efficacy of glass ionomer, zinc phosphate and zinc polycarboxylate luting cements in preformed stainless steel crowns: a comparative clinical study.

    Science.gov (United States)

    Khinda, V I S; Grewal, N

    2002-06-01

    This study was undertaken to assess the efficacy of three luting cements, namely, glass ionomer, zinc phosphate and zinc polycarboxylate in retainng the preformed stainless steel crowns in-vivo. Twenty subjects, with an indication for restoration of three primary molars with stainless steel crowns, were selected. Sixty teeth were taken up for the study, and twenty crowns were cemented with each of the three luting cements. After an eight month follow up the crowns were assessed for their presence/ absence or "rocking". Statistical analysis was done using Chi-square test. The results have shown no significant difference in retentivity of stainless steel crowns with the use of either of the three luting agents.

  2. Electronic polarizability, optical basicity and interaction parameter for Nd{sub 2}O{sub 3} doped lithium-zinc-phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Algradee, M.A.; Sultan, M.; Samir, O.M.; Alwany, A.E.B. [Ibb University, Department of Physics, Faculty of Science, Ibb (Yemen)

    2017-08-15

    The Nd{sup 3+}-doped lithium-zinc-phosphate glasses were prepared by means of conventional melt quenching method. X-ray diffraction results confirmed the glassy nature of the studied glasses. The physical parameters such as the density, molar volume, ion concentration, polaron radius, inter-ionic distance, field strength and oxygen packing density were calculated using different formulae. The transmittance and reflectance spectra of glasses were recorded in the wavelength range 190-1200 nm. The values of optical band gap and Urbach energy were determined based on Mott-Davis model. The refractive indices for the studied glasses were evaluated from optical band gap values using different methods. The average electronic polarizability of the oxide ions, optical basicity and an interaction parameter were investigated from the calculated values of the refractive index and the optical band gap for the studied glasses. The variations in the different physical and optical properties of glasses with Nd{sub 2}O{sub 3} content were discussed in terms of different parameters such as non-bridging oxygen and different concentrations of Nd cation in glass system. (orig.)

  3. Cathodic protection of steel by electrodeposited zinc-nickel alloy coatings

    Energy Technology Data Exchange (ETDEWEB)

    Baldwin, K.R.; Smith, C.J.E. [Defence Research Agency, Farnborough (United Kingdom). Structural Materials Centre; Robinson, M.J. [Cranfield Univ. (United Kingdom). School of Industrial and Manufacturing Science

    1995-12-01

    The ability of electrodeposited zinc-nickel alloy coatings to cathodically protect steel was studied in dilute chloride solutions. The potential distribution along steel strips partly electroplated with zinc-nickel alloys was determined, and the length of exposed steel that was held below the minimum protection potential (E{sub prot}) was taken as a measure of the level of cathodic protection (CP) provided by the alloy coatings. The level of CP afforded by zinc alloy coatings was found to decrease with increasing nickel content. When nickel content was increased to {approx} {ge} 21 wt%, no CP was obtained. Surface analysis of uncoupled zinc-nickel alloys that were immersed in sodium chloride (NaCl) solutions showed the concentration of zinc decreased in the surface layers while the concentration of nickel increased, indicating that the alloys were susceptible to dezincification. The analysis of zinc-nickel alloy coatings on partly electroplated steel strips that were immersed in chloride solution showed a significantly higher level of dezincification than that found for uncoupled alloy coatings. This effect accounted for the rapid loss of CP afforded to steel by some zinc alloy coatings, particularly those with high initial nickel levels.

  4. Anticorrosive Performance of Zinc Phosphate Coatings on Mild Steel Developed Using Galvanic Coupling

    Directory of Open Access Journals (Sweden)

    M. Arthanareeswari

    2013-01-01

    Full Text Available The anticorrosive performance of zinc phosphate coatings developed by galvanic coupling technique on mild steel substrates using the cathode materials such as titanium (Ti, copper (Cu, brass (BR, nickel (Ni, and stainless steel (SS is elucidated in this study. Thermal and chemical stability tests, immersion test in 3.5% NaCl, ARE salt droplet test, and salt spray test were carried out. The study reveals that the mild steel substrates phosphated under galvanically coupled condition showed better corrosion resistance than the one coated without coupling. The open circuit potential (OCP of phosphated mild steel panels in 3.5% NaCl was found to be a function of phosphate coating weight and porosity of the coating.

  5. Protective effects of zinc acetate toward the toxicity of nickelous acetate in rats

    International Nuclear Information System (INIS)

    Waalkes, M.P.; Kasprzak, K.S.; Ohshima, M.; Poirier, L.A.

    1985-01-01

    This study was designed to determine the effects of zinc pretreatment on the acute toxicity of nickel. Male Fischer rats received either nickel alone (i.p.), zinc alone (s.c.), zinc plus nickel, or saline (i.p. and s.c.; controls). Zinc pretreatment significantly increased the 14-day survival of nickel-related rats. Zinc did not, however, prevent the reduction in weight gain over 2 weeks seen with nickel treatment. Histopathologically, at 120 h following nickel exposure, kidneys in the group receiving nickel alone generally showed moderate nephropathy (multifocal proximal tubule degeneration with necrosis) while in the zinc plus nickel group the nephropathy was generally mild. Zinc pretreatment had no apparent effect on the pharmacokinetics of nickel over 24 h as assessed by urinary excretion, blood levels or organ distribution. Zinc pretreatment also did not alter the subcellular distribution of renal nickel 6 h after nickel exposure. Enhanced synthesis of metallothionein did not appear to play a critical role in the reduction of nickel toxicity, since renal concentrations of this metalbuilding protein, although elevated compared to control, were not different in rats receiving zinc and nickel or zinc alone. Zinc pretreatment did, however, have marked effect on nickel-induced hyperglycemia, reducing both the duration and severity of elevated blood glucose levels. Results of the study show that zinc can prevent some of the toxic effects of nickel and that the mechanism of this action does not appear to involve either metalothionein or alterations in the pharmacokinetics of nickel. (author)

  6. Hydrogen permeation inhibition by zinc-nickel alloy plating on steel XC68

    International Nuclear Information System (INIS)

    El Hajjami, A.; Gigandet, M.P.; De Petris-Wery, M.; Catonne, J.C.; Duprat, J.J.; Thiery, L.; Raulin, F.; Starck, B.; Remy, P.

    2008-01-01

    The inhibition of hydrogen permeation and barrier effect by zinc-nickel plating was investigated using the Devanathan-Stachurski permeation technique. The hydrogen permeation and hydrogen diffusion for the zinc-nickel (12-15%) plating on steel XC68 is compared with zinc and nickel. Hydrogen permeation and hydrogen diffusion were followed as functions of time at current density applied (cathodic side) and potential permanent (anodic side). The hydrogen permeation inhibition for zinc-nickel is intermediate to that of nickel and zinc. This inhibition was due to nickel-rich layer effects at the Zn-Ni alloy/substrate interface, is shown by GDOES. Zinc-nickel plating inhibited the hydrogen diffusion greater as compared to zinc. This diffusion resistance was due to the barrier effect caused by the nickel which is present at the interface and transformed the hydrogen atomic to Ni 2 H compound, as shown by GIXRD.

  7. Hydrogen permeation inhibition by zinc-nickel alloy plating on steel XC68

    Energy Technology Data Exchange (ETDEWEB)

    El Hajjami, A. [Institut UTINAM, UMR CNRS 6213, Sonochimie et Reactivite des Surfaces, Universite de Franche-Comte, 16 route de Gray, 25030 Besancon Cedex (France); Coventya S.A.S., 51 rue Pierre, 92588 Clichy Cedex (France); Gigandet, M.P. [Institut UTINAM, UMR CNRS 6213, Sonochimie et Reactivite des Surfaces, Universite de Franche-Comte, 16 route de Gray, 25030 Besancon Cedex (France)], E-mail: marie-pierre.gigandet@univ-fcomte.fr; De Petris-Wery, M. [Institut Universitaire de Technologie d' Orsay, Universite Paris XI, Plateau de Moulon, 91400 Orsay (France); Catonne, J.C. [Professeur Honoraire du Conservatoire national des arts et metiers (CNAM), Paris (France); Duprat, J.J.; Thiery, L.; Raulin, F. [Coventya S.A.S., 51 rue Pierre, 92588 Clichy Cedex (France); Starck, B.; Remy, P. [Lisi Automotive, 28 faubourg de Belfort, BP 19, 90101 Delle Cedex (France)

    2008-12-30

    The inhibition of hydrogen permeation and barrier effect by zinc-nickel plating was investigated using the Devanathan-Stachurski permeation technique. The hydrogen permeation and hydrogen diffusion for the zinc-nickel (12-15%) plating on steel XC68 is compared with zinc and nickel. Hydrogen permeation and hydrogen diffusion were followed as functions of time at current density applied (cathodic side) and potential permanent (anodic side). The hydrogen permeation inhibition for zinc-nickel is intermediate to that of nickel and zinc. This inhibition was due to nickel-rich layer effects at the Zn-Ni alloy/substrate interface, is shown by GDOES. Zinc-nickel plating inhibited the hydrogen diffusion greater as compared to zinc. This diffusion resistance was due to the barrier effect caused by the nickel which is present at the interface and transformed the hydrogen atomic to Ni{sub 2}H compound, as shown by GIXRD.

  8. Electrical properties of phosphate glasses

    International Nuclear Information System (INIS)

    Mogus-Milankovic, A; Santic, A; Reis, S T; Day, D E

    2009-01-01

    Investigation of the electrical properties of phosphate glasses where transition metal oxide such as iron oxide is the network former and network modifier is presented. Phosphate glasses containing iron are electronically conducting glasses where the polaronic conduction is due to the electron hopping from low to high iron valence state. The identification of structural defects caused by ion/polaron migration, the analysis of dipolar states and electrical conductivity in iron phosphate glasses containing various alkali and mixed alkali ions was performed on the basis of the impedance spectroscopy (IS). The changes in electrical conductivity from as-quenched phosphate glass to fully crystallized glass (glass-ceramics) by IS are analyzed. A change in the characteristic features of IS follows the changes in glass and crystallized glass network. Using IS, the contribution of glass matrix, crystallized grains and grain boundary to the total electrical conductivity for iron phosphate glasses was analyzed. It was shown that decrease in conductivity is caused by discontinuities in the conduction pathways as a result of the disruption of crystalline network where two or more crystalline phases are formed. Also, phosphate-based glasses offer a unique range of biomaterials, as they form direct chemical bonding with hard/soft tissue. The surface charges of bioactive glasses are recognized to be the most important factors in determining biological responses. The improved bioactivity of the bioactive glasses as a result of the effects of the surface charges generated by electrical polarization is discussed.

  9. Essential elucidation for preparation of supported nickel phosphide upon nickel phosphate precursor

    International Nuclear Information System (INIS)

    Liu, Xuguang; Xu, Lei; Zhang, Baoquan

    2014-01-01

    Preparation of supported nickel phosphide (Ni 2 P) depends on nickel phosphate precursor, generally related to its chemical composition and supports. Study of this dependence is essential and meaningful for the preparation of supported Ni 2 P with excellent catalytic activity. The chemical nature of nickel phosphate precursor is revealed by Raman and UV–vis spectra. It is found that initial P/Ni mole ratio ≥0.8 prohibits the Ni-O-Ni bridge bonding (i.e., nickel oxide). This chemical bonding will not result in Ni 2 P structure, verified by XRD characterization results. The alumina (namely, γ-Al 2 O 3 , θ-Al 2 O 3 , or α-Al 2 O 3 ) with distinct physiochemical properties also results in diverse chemical nature of nickel phosphate, and then different nickel phosphides. The influence of alumina support on producing Ni 2 P was explained by the theory of surface energy heterogeneity, calculated by the NLDFT method based on N 2 -sorption isotherm. The uniform surface energy of α-Al 2 O 3 results only in the nickel phosphosate precursor and thus the Ni 2 P phase. - Graphical abstract: Surface energy heterogeneity in alumina (namely α-Al 2 O 3 , θ-Al 2 O 3 , and γ-Al 2 O 3 ) supported multi-oxidic precursors with different reducibilities and thus diverse nickel phosphides (i.e., Ni 3 P, Ni 12 P 5 , Ni 2 P). - Highlights: • Preparing pure Ni 2 P. • Elucidating nickel phosphate precursor. • Associating with surface energy

  10. Study on the water durability of zinc boro-phosphate glasses doped with MgO, Fe2O3, and TiO2

    Science.gov (United States)

    Hwang, Moon Kyung; Ryu, Bong Ki

    2016-07-01

    The water durability of zinc boro-phosphate (PZB) glasses with the composition 60P2O5-20ZnO-20B2O3- xMeO ( x = 0, 2, 4, 6 and MeO = MgO, Fe2O3, or TiO2) (mol%) was measured, and PZB glass was studied in terms of its thermal properties, density, and FTIR characteristics. The surface conditions and corrosion byproducts were analyzed using scanning electron microscopy. When MgO, Fe2O3, and TiO2 were doped into the PZB glass, Q2 was decreased and Q1 was increased in the phosphate structure, while the number of BO4 structures increased with increasing MeO content. The density of the PZB glass was increased by the addition of Fe2O3 and TiO2, while the glass transition temperature ( T g ) and dilatometric softening temperature ( T d ) were increased when additional MgO, Fe2O3, and TiO2 were added. From the weight loss analysis (95 ◦ C, 96 h), TiO2 doped glass showed the lowest weight loss (1.70 × 10 -3 g/cm2) while MgO doped glass showed the highest value (2.44 × 10 -3 g/cm2), compared with PZB glass (3.07 × 10 -3 g/cm2). These results were discussed in terms of the Me n+ ions in the glass structure, and their different coordination numbers and bonding strengths.

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

    International Nuclear Information System (INIS)

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

    2014-01-01

    Detailed characterization was carried out on an iron phosphate glass waste form containing 20 wt.% of a simulated nuclear waste. High temperature viscosity measurement was carried out by the rotating spindle method. The Fe 3+ /Fe ratio and structure of this waste loaded iron phosphate glass was investigated using Mössbauer and Raman spectroscopy respectively. Specific heat measurement was carried out in the temperature range of 300–700 K using differential scanning calorimeter. Isoconversional kinetic analysis was employed to understand the crystallization behavior of the waste loaded iron phosphate glass. The glass forming ability and glass stability of the waste loaded glass were also evaluated. All the measured properties of the waste loaded glass were compared with the characteristics of pristine iron phosphate glass

  12. Optical properties and energy transfer behavior from Tb{sup 3+} to Mn{sup 2+} ions in co-doped zinc strontium phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Liang Xiaoluan [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Xing Zhongwen [Department of Materials Science and Engineering, Nanjing University, Nanjing 210093 (China); Liu Yinyao; Xu Weina; Yang Yunxia [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Chen Guorong, E-mail: grchen@ecust.edu.cn [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China)

    2011-10-17

    Highlights: {yields} We choose Tb{sup 3+} as the sensitizer to enhance the emission of Mn{sup 2+} ions in ZSP glasses. {yields} We make a serious of characterization on the optical properties of the glasses. {yields} Tb{sup 3+} can transfer its energy to the neighbor Mn{sup 2+} during excitation process. {yields} The energy transfer mechanism is dipolar-quadrupole interaction in phosphate glasses. {yields} Meanwhile, this process is taken by two modes: cross-relaxation and resonant transfer. - Abstract: In this paper, we report optical properties and energy transfer behavior between Tb and Mn in zinc strontium phosphate glasses. Electron Paramagnetic Resonance spectra indicate a stronger hyperfine interaction of Mn{sup 2+}-Mn{sup 2+} pairs with higher MnO concentrations. The co-existence of Tb{sup 3+} and Mn{sup 2+} ions in glasses is clearly evident in the transmittance spectra. Emission spectra show an obvious energy transfer from Tb{sup 3+} to Mn{sup 2+} ions in glasses. Based on Dexter's energy transfer formula and Reisfeld's approximation, the energy transfer mechanism was postulated to proceed via a dipolar-quadrupole interaction. The energy transfer carries out with resonant and cross-relaxation transfer modes with the understanding of Tb{sup 3+} and Mn{sup 2+} energy level diagrams. The decreasing in mean-duration time ({tau}{sub mean}) of Tb{sup 3+} ions obtained from the decay curves make a further evidence of energy transfer from Tb{sup 3+} to Mn{sup 2+} ions in glasses.

  13. Orange and reddish-orange light emitting phosphors: Sm{sup 3+} and Sm{sup 3+}/Eu{sup 3+} doped zinc phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Meza-Rocha, A.N., E-mail: ameza@fis.cinvestav.mx [Departamento de Física, Universidad Autónoma Metropolitana-Iztapalapa, P.O. Box 55-534, 09340 México D.F., México (Mexico); Speghini, A. [Dipartimento di Biotecnologie, Universita di Verona and INSTM, UdR Verona, Strada Le Grazie 15, I-37314 Verona (Italy); IFAC CNR, Nello Carrara Institute of Applied Physics, MDF Lab, I-50019 Sesto Fiorentino, FI (Italy); Bettinelli, M. [Dipartimento di Biotecnologie, Universita di Verona and INSTM, UdR Verona, Strada Le Grazie 15, I-37314 Verona (Italy); Caldiño, U. [Departamento de Física, Universidad Autónoma Metropolitana-Iztapalapa, P.O. Box 55-534, 09340 México D.F., México (Mexico)

    2015-11-15

    A spectroscopy study of Sm{sup 3+} and Sm{sup 3+}/Eu{sup 3+} doped zinc phosphate glasses is performed through photoluminescence spectra and decay time profile measurements. Under Sm{sup 3+} excitation at 344 nm, the Sm{sup 3+} singly doped glass shows an orange global emission with x=0.579 and y=0.414 CIE1931 chromaticity coordinates, whereas the Sm{sup 3+}/Eu{sup 3+} co-doped sample exhibits orange overall emissions (x=0.581 and y=0.398, and x=0.595 and y=0.387) and reddish-orange overall emission (x=0.634 and y=0.355) upon excitations at 344, 360 and 393 nm, respectively. Such luminescence from the co-doped sample is originated by the simultaneous emission of Sm{sup 3+} and Eu{sup 3+}. Under Sm{sup 3+} excitation at 344 and 360 nm, the Eu{sup 3+} emission is sensitized and enhanced by Sm{sup 3+} through a non-radiative energy transfer process. The non-radiative nature was inferred from the shortening of the Sm{sup 3+} lifetime observed in the Sm{sup 3+}/Eu{sup 3+} co-doped sample. An analysis of the Sm{sup 3+} emission decay time profiles using the Inokuti–Hirayama model suggests that an electric quadrupole–quadrupole interaction into Sm–Eu clusters might dominate the energy transfer process, with an efficiency of 0.17. - Highlights: • Zinc phosphate glasses are optically activated with Sm{sup 3+}/Eu{sup 3+} (ZPOSmEu). • Non-radiative energy transfer Sm{sup 3+}→Eu{sup 3+} takes place in ZPOSmEu. • ZPOSmEu overall emission can be modulated with the excitation wavelength. • ZPOSmEu might be useful as orange/reddish-orange phosphor for UV-white LEDs.

  14. Zinc-nickel alloy electrodeposits for water electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Sheela, G.; Pushpavanam, Malathy; Pushpavanam, S. [Central Electrochemical Research Inst., Karaikudi (India)

    2002-06-01

    Electrodeposited zinc-nickel alloys of various compositions were prepared. A suitable electrolyte and conditions to produce alloys of various compositions were identified. Alloys produced on electroformed nickel foils were etched in caustic to leach out zinc and to produce the Raney type, porous electro catalytic surface for hydrogen evolution. The electrodes were examined by polarisation measurements, to evaluate their Tafel parameters, cyclic voltammetry, to test the change in surface properties on repeated cycling, scanning electron microscopy to identify their microstructure and X-ray diffraction. The catalytic activity as well as the life of the electrode produced from 50% zinc alloy was found to be better than others. (Author)

  15. Corrosion inhibition by lithium zinc phosphate pigment

    International Nuclear Information System (INIS)

    Alibakhshi, E.; Ghasemi, E.; Mahdavian, M.

    2013-01-01

    Highlights: •Synthesis of lithium zinc phosphate (LZP) by chemical co-precipitation method. •Corrosion inhibition activity of pigments compare with zinc phosphate (ZP). •LZP showed superior corrosion inhibition effect in EIS measurements. •Evaluation of adhesion strength and dispersion stability. -- Abstract: Lithium zinc phosphate (LZP) has been synthesized through a co-precipitation process and characterized by XRD and IR spectroscopy. The inhibitive performances of this pigment for corrosion of mild steel have been discussed in comparison with the zinc phosphate (ZP) in the pigment extract solution by means of EIS and in the epoxy coating by means of salt spray. The EIS and salt spray results revealed the superior corrosion inhibitive effect of LZP compared to ZP. Moreover, adhesion strength and dispersion stability of the pigmented epoxy coating showed the advantage of LZP compared to ZP

  16. Histidine protects against zinc and nickel toxicity in Caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    John T Murphy

    2011-03-01

    Full Text Available Zinc is an essential trace element involved in a wide range of biological processes and human diseases. Zinc excess is deleterious, and animals require mechanisms to protect against zinc toxicity. To identify genes that modulate zinc tolerance, we performed a forward genetic screen for Caenorhabditis elegans mutants that were resistant to zinc toxicity. Here we demonstrate that mutations of the C. elegans histidine ammonia lyase (haly-1 gene promote zinc tolerance. C. elegans haly-1 encodes a protein that is homologous to vertebrate HAL, an enzyme that converts histidine to urocanic acid. haly-1 mutant animals displayed elevated levels of histidine, indicating that C. elegans HALY-1 protein is an enzyme involved in histidine catabolism. These results suggest the model that elevated histidine chelates zinc and thereby reduces zinc toxicity. Supporting this hypothesis, we demonstrated that dietary histidine promotes zinc tolerance. Nickel is another metal that binds histidine with high affinity. We demonstrated that haly-1 mutant animals are resistant to nickel toxicity and dietary histidine promotes nickel tolerance in wild-type animals. These studies identify a novel role for haly-1 and histidine in zinc metabolism and may be relevant for other animals.

  17. Use of radioactive tracers in chemical reactions. the displacement of zinc-nickel complexes with quantitative determination of nickel

    International Nuclear Information System (INIS)

    Mazzilli, B.; Saiki, M.

    1983-01-01

    The present paper presents a method for the determination of small quantities of nickel radioactive tracers. An analytical application of the displacement reaction between nickel and zinc ethylenediaminetetraacetate labeled with zinc-65 is pursued. This method is based on the extraction of radioactive zinc displaced by nickel from the zinc chelate into a dithizone-carbon tetrachloride solution and the subsequent measurement of the activity of an aliquot of the extract. The method is very sensitive and nickel can be measured in concentrations as small as 0.1 μg/ml or even less, depending on the specific activity of the radioreagent used. The precision and the accuracy of the method are determined. The problem of interferences is also investigated and an attempt is made in order to eliminate them by using masking agents or by means of a previous separation between nickel and other interfering metals. (Author) [pt

  18. Electrochemical Reduction of Zinc Phosphate

    International Nuclear Information System (INIS)

    Kim, Chang Hwan; Lee, Jung Hyun; Shin, Woon Sup

    2010-01-01

    We demonstrated first that the electrochemical reduction of zinc phosphate in neutral phosphate buffer is possible and potentially applicable to bio-compatible rechargeable battery. The actual redox component is Zn(s)/Zn phosphate(s) and the future research about the control of crystal formation for the better cyclability is required. In lead-acid battery, the electrochemical redox reaction of Pb (s) /PbSO 4(s) is used by reducing Pb(II) and oxidizing Pb(0) in sulfate rich solution. Since both reduced form and oxidized form are insoluble, they cannot diffuse to the opposite electrodes and react. It is a very common strategy to make a stable battery electrode that a metal element is reduced and oxidized in solution containing an abundance of anion readily precipitating with the metal ion. For the application of this strategy to construction of rechargeable battery using bio-compatible electrode materials and electrolytes, the use of phosphate ion can be considered as anion readily precipitating with metal ions. If phosphate buffer with neutral pH is used as electrolyte, the better bio-compatibility will be achieved than most of rechargeable battery using strong acid, strong base or organic solvent as electrolyte solution. There are many metal ions readily precipitating with phos-phate ion, and zinc is one of them

  19. Nano zinc phosphate coatings for enhanced corrosion resistance of mild steel

    International Nuclear Information System (INIS)

    Tamilselvi, M.; Kamaraj, P.; Arthanareeswari, M.; Devikala, S.

    2015-01-01

    Highlights: • Nano zinc phosphate coating on mild steel was developed. • Nano zinc phosphate coatings on mild steel showed enhanced corrosion resistance. • The nano ZnO increases the number of nucleating sites for phosphating. • Faster attainment of steady state during nano zinc phosphating. - Abstract: Nano crystalline zinc phosphate coatings were developed on mild steel surface using nano zinc oxide particles. The chemical composition and morphology of the coatings were analyzed by X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). The particles size of the nano zinc phosphate coating developed was also characterized by TEM analysis. Potentiodynamic polarization and electrochemical impedance studies were carried out in 3.5% NaCl solution. Significant variations in the coating weight, morphology and corrosion resistance were observed as nano ZnO concentrations were varied from 0.25 to 2 g/L in the phosphating baths. The results showed that nano ZnO particles in the phosphating solution yielded phosphate coatings of higher coating weight, greater surface coverage and enhanced corrosion resistance than the normal zinc phosphate coatings (developed using normal ZnO particles in the phosphating baths). Better corrosion resistance was observed for coatings derived from phosphating bath containing 1.5 g/L nano ZnO. The activation effect brought about by the nano ZnO reduces the amount of accelerator (NaNO 2 ) required for phosphating

  20. An evaluation of airborne nickel, zinc, and lead exposure at hot dip galvanizing plants.

    Science.gov (United States)

    Verma, D K; Shaw, D S

    1991-12-01

    Industrial hygiene surveys were conducted at three hot dip galvanizing plants to determine occupational exposure to nickel, zinc, and lead. All three plants employed the "dry process" and used 2% nickel, by weight, in their zinc baths. A total of 32 personal and area air samples were taken. The air samples were analyzed for nickel, zinc, and lead. Some samples were also analyzed for various species of nickel (i.e., metallic, soluble, and oxidic). The airborne concentrations observed for nickel and its three species, zinc, and lead at the three plants were all well below the current and proposed threshold limit values recommended by the American Conference of Governmental Industrial Hygienists (ACGIH).

  1. Effect of Ba in the glass characteristics of cesium loaded iron phosphate glasses

    International Nuclear Information System (INIS)

    Joseph, Kitheri; Asuvathraman, R.; Vasudeva Rao, P.R.

    2015-01-01

    Radioactive 137 Cs extracted from high level nuclear waste, when immobilized in a suitable matrix can be used as a γsource in medical industry. Iron phosphate glass (IPG) is one of a suitable matrix for the immobilization of 137 Cs prior to the immobilization of 137 Cs in IPG, it is essential to optimize the immobilization conditions using natural (inactive) cesium. Glass characteristics of inactive Cs loaded iron phosphate glasses were already explored in our earlier studies. However, the change in glass characteristics of 137 Cs loaded iron phosphate glass to 137 Ba loaded iron phosphate glass need to be studied before the immobilization of 137 Cs in iron phosphate glass as 137 Cs transforms to 137 Ba due to nuclear transmutation ( 137 Cs(β,γ) 137 Ba). This paper reports the studies on such a behaviour by incorporating inactive Ba in cesium loaded iron phosphate glasses. Cs and Ba loaded iron phosphate glasses were prepared by melt quench technique in air using appropriate amounts of Fe 2 O 3 , NH 4 H 2 PO 4 , Ba(OH) 2.8 H 2 O and Cs 2 CO 3 . The chemicals were added such that the glass formed possesses the batch composition of (a) 21.4 wt. % Fe 2 O 3 -45 wt. % Cs 2 O-5 wt % BaO-P 2 O 5 (henceforth referred as IP50Cs45Ba5); (b) 21.4 wt. % Fe 2 O 3 -25 wt. % Cs 2 O-25 wt % BaO-P 2 O5 (henceforth referred as IP50Cs25Ba25). The thermal expansion measurements were also carried out using a home-built quartz push-rod dilatometer. The data related to change in thermal expansion behaviour, glass forming ability, glass stability and structural changes in phosphate network due to the partial replacement of Cs with Ba will also be discussed. (author)

  2. Effect of shelf life on compressive strength of zinc phosphate cement

    Science.gov (United States)

    Dwiputri, D. R.; Damiyanti, M.; Eriwati, Y. K.

    2017-08-01

    Usage of zinc phosphate cements with no account of the shelf life left before the expiry date can affect its compressive strength. The aim of this study is to determine the different compressive strength values of zinc phosphate cement with different shelf lives before expiry. Three groups of zinc phosphate cement (GC Elite cement 100) with different expiry dates were tested for compressive strength using a universal testing machine (crosshead speed 1 mm/min: load cell of 250 kgF). The results showed that there was a significant difference (p<0.05) between the compressive strengths of zinc phosphate cement in group III (2 months before expiry date), group I (2 years and 5 months before expiry date), and group II (11 months before expiry date). It can be concluded that there is a significant decrease in compressive strength of zinc phosphate cement near its expiry date.

  3. Nickel-iron spherules from aouelloul glass

    Science.gov (United States)

    Chao, E.C.T.; Dwornik, E.J.; Merrill, C.W.

    1966-01-01

    Nickel-iron spherules, ranging from less than 0.2 to 50 microns in diameter and containing 1.7 to 9.0 percent Ni by weight, occur in glass associated with the Aouelloul crater. They occur in discrete bands of siliceous glass enriched in dissolved iron. Their discovery is significant tangible evidence that both crater and glass originated from terrestrial impact.

  4. Nuclear waste immobilization in iron phosphate glasses

    International Nuclear Information System (INIS)

    Garcia, D.A.; Rodriguez, Diego A.; Menghini, Jorge E.; Bevilacqua, Arturo

    2007-01-01

    Iron-phosphate glasses have become important in the nuclear waste immobilization area because they have some advantages over silicate-based glasses, such as a lower processing temperature and a higher nuclear waste load without losing chemical and mechanical properties. Structure and chemical properties of iron-phosphate glasses are determined in terms of the main components, in this case, phosphate oxide along with the other oxides that are added to improve some of the characteristics of the glasses. For example, Iron oxide improves chemical durability, lead oxide lowers fusion temperature and sodium oxide reduces viscosity at high temperature. In this work a study based on the composition-property relations was made. We used different techniques to characterize a series of iron-lead-phosphate glasses with uranium and aluminium oxide as simulated nuclear waste. We used the Arquimedes method to determine the bulk density, differential temperature analysis (DTA) to determine both glass transition temperature and crystallization temperature, dilatometric analysis to calculate the linear thermal expansion coefficient, chemical durability (MCC-1 test) and X-ray diffraction (XRD). We also applied some theoretic models to calculate activation energies associated with the glass transition temperature and crystallization processes. (author)

  5. Electrodeposition of zinc-nickel alloy from fluoborate baths - as a substitute for electrogalvanising

    Energy Technology Data Exchange (ETDEWEB)

    Ramesh Bapu, G.N.K.; Ayyapparaju, J.; Devaraj, G.

    Use of fluoborate electroytes have been investigated for depositing a suitable composition of zinc-nickel alloy on mild steel for better corrosion protection. In the present investigation, the plating and bath conditions have been optimized so that zinc-nickel alloy coating from fluoborate solutions find applications for plating wires as well as other articles advantageously in the place of zinc coatings.

  6. New greenish-yellow and yellowish-green emitting glass phosphors: Tb{sup 3+}/Eu{sup 3+} and Ce{sup 3+}/Tb{sup 3+}/Eu{sup 3+} in zinc phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Caldino, U., E-mail: cald@xanum.uam.mx [Departamento de Fisica, Universidad Autonoma Metropolitana-Iztapalapa, P.O. Box 55-534, 09340 Mexico D.F. (Mexico); Alvarez, E. [Departamento de Fisica, Universidad de Sonora (UNISON), Boulevard Luis Encinas y Rosales s/n, Hermosillo, Sonora 83000, Mexico (Mexico); Speghini, A. [Dipartimento di Biotecnologie, Universita di Verona, and INSTM, UdR Verona, Strada Le Grazie 15, I-37314 Verona (Italy); IFAC CNR, Nello Carrara Institute of Applied Physics, MDF Lab, I-50019 Sesto Fiorentino, FI (Italy); Bettinelli, M. [Dipartimento di Biotecnologie, Universita di Verona, and INSTM, UdR Verona, Strada Le Grazie 15, I-37314 Verona (Italy)

    2013-03-15

    A spectroscopic investigation of zinc phosphate glasses activated with Eu{sup 3+}, Tb{sup 3+}/Eu{sup 3+} and Ce{sup 3+}/Tb{sup 3+}/Eu{sup 3+} ions is performed through photoluminescence spectra and decay time measurements. Greenish-yellow light emission, with x=0.42 and y=0.50 CIE1931 chromaticity coordinates, is obtained in the 5.0% Tb(PO{sub 3}){sub 3}-2.0% Eu(PO{sub 3}){sub 3} codoped zinc phosphate glass upon Tb{sup 3+} excitation at 340 nm. Such greenish-yellow luminescence is generated mainly by the {sup 5}D{sub 4}{yields}{sup 7}F{sub 6,5} and {sup 5}D{sub 0}{yields}{sup 7}F{sub 1,2} emissions of Tb{sup 3+} and Eu{sup 3+}, respectively, europium being sensitized by terbium through a non-radiative energy transfer. By codoping with 0.1 Ce(PO{sub 3}){sub 3} in addition to Tb{sup 3+}/Eu{sup 3+} yellowish-green light emission with CIE1931 chromaticity coordinates, x=0.33 and y=0.48, is achieved through non-radiative energy transfer from Ce{sup 3+} to Tb{sup 3+} and from Ce{sup 3+} via Tb{sup 3+} to Eu{sup 3+} upon 280 nm excitation (peak emission wavelength of AlGaN-based LEDs). - Highlights: Black-Right-Pointing-Pointer Zn(PO{sub 3}){sub 2} glasses are optically activated with Tb{sup 3+}/Eu{sup 3+} (ZPO5Tb2Eu) and Ce{sup 3+}/Eu{sup 3+}/Tb{sup 3+} (ZPOCe5Tb2Eu). Black-Right-Pointing-Pointer Non-radiative energy transfer Tb{sup 3+}{yields}Eu{sup 3+} takes place in ZPO5Tb2Eu. Black-Right-Pointing-Pointer Greenish-yellow light is generated by ZPO5Tb2Eu pumped with 340 nm-UV light. Black-Right-Pointing-Pointer Non-radiative energy transfer Ce{sup 3+}{yields}Tb{sup 3+} and Ce{sup 3+}{yields}Eu{sup 3+} via Tb{sup 3+} takes place in ZPOCe5Tb2Eu. Black-Right-Pointing-Pointer Yellowish-green light is generated by ZPOCe5Tb2Eu pumped with 280 nm-UV light (AlGaN-LEDs).

  7. Studies on influence of zinc immersion and fluoride on nickel electroplating on magnesium alloy AZ91D

    International Nuclear Information System (INIS)

    Zhang Ziping; Yu Gang; Ouyang Yuejun; He Xiaomei; Hu Bonian; Zhang Jun; Wu Zhenjun

    2009-01-01

    The effect of zinc immersion and the role of fluoride in nickel plating bath were mainly investigated in nickel electroplating on magnesium alloy AZ91D. The state of zinc immersion, the composition of zinc film and the role of fluoride in nickel plating bath were explored from the curves of open circuit potential (OCP) and potentiodynamic polarization, the images of scanning electron microscopy (SEM) and the patterns of energy dispersive X-ray (EDX). Results show that the optimum zinc film mixing small amount of Mg(OH) 2 and MgF 2 is obtained by zinc immersion for 30-90 s. The corrosion potential of magnesium alloy substrate attached zinc film will be increased in nickel plating bath and the quantity of MgF 2 sandwiched between magnesium alloy substrate and nickel coating will be reduced, which contributed to produce nickel coating with good performance. Fluoride in nickel plating bath serves as an activator of nickel anodic dissolution and corrosion inhibitor of magnesium alloy substrate. 1.0-1.5 mol dm -3 of F - is the optimum concentration range for dissolving nickel anode and protecting magnesium alloy substrate from over-corrosion in nickel plating bath. The nickel coating with good adhesion and high corrosion resistance on magnesium alloy AZ91D is obtained by the developed process of nickel electroplating. This nickel layer can be used as the rendering coating for further plating on magnesium alloys.

  8. Radiation induced traps of zinc phosphate and phosphide

    International Nuclear Information System (INIS)

    Murali, K.R.; Rao, D.R.

    1980-01-01

    Thermoluminescence (TL) glow curve (TGC) method has been used to study the traps produced by X-irradiation in Zn 3 (PO 4 ) 2 and Zn 3 P 2 . Prominent TL glow peaks were observed at 100 0 and 360 0 C for zinc phosphate while for zinc phosphide only one glow peak at 245 0 C was observed, and in the latter case the TL output was in general quite low compared to zinc phosphate. The TL spectra for both the glow peaks of zinc phosphate indicated emission band in the region around 560 nm, while for zinc phosphide the emission occurred at 575 nm (in the temperature region 200-270 0 C). The low temperature glow peaks below 270 0 C were less stable compared to those above 300 0 C and were completely destroyed when the irradiated samples were stored in darkness for 24 hr at room temperature. Shining by 470 nm light however produced preferential bleaching of the two TL peaks at 100 and 360 0 C with no effect on the 245 0 C glow peak of zinc phosphide. It is concluded that during heat treatment large numbers of Zn-vacancies are formed due to which complexes like Zn-P are produced by irradiation and the TL traps destroyed in a radiative recombination process are related with these complexes. (author)

  9. Monte Carlo Simulations of Phosphate Polyhedron Connectivity in Glasses

    Energy Technology Data Exchange (ETDEWEB)

    ALAM,TODD M.

    1999-12-21

    Monte Carlo simulations of phosphate tetrahedron connectivity distributions in alkali and alkaline earth phosphate glasses are reported. By utilizing a discrete bond model, the distribution of next-nearest neighbor connectivities between phosphate polyhedron for random, alternating and clustering bonding scenarios was evaluated as a function of the relative bond energy difference. The simulated distributions are compared to experimentally observed connectivities reported for solid-state two-dimensional exchange and double-quantum NMR experiments of phosphate glasses. These Monte Carlo simulations demonstrate that the polyhedron connectivity is best described by a random distribution in lithium phosphate and calcium phosphate glasses.

  10. Iron phosphate glasses: Bulk properties and atomic scale structure

    Energy Technology Data Exchange (ETDEWEB)

    Joseph, Kitheri; Stennett, Martin C.; Hyatt, Neil C.; Asuvathraman, R.; Dube, Charu L.; Gandy, Amy S.; Govindan Kutty, K. V.; Jolley, Kenny; Vasudeva Rao, P. R.; Smith, Roger

    2017-10-01

    Bulk properties such as glass transition temperature, density and thermal expansion of iron phosphate glass compositions, with replacement of Cs by Ba, are investigated as a surrogate for the transmutation of 137Cs to 137Ba, relevant to the immobilisation of Cs in glass. These studies are required to establish the appropriate incorporation rate of 137Cs in iron phosphate glass. Density and glass transition temperature increases with the addition of BaO indicating the shrinkage and reticulation of the iron phosphate glass network. The average thermal expansion coefficient reduces from 19.8 × 10-6 K-1 to 13.4 × 10-6 K-1, when 25 wt. % of Cs2O was replaced by 25 wt. % of BaO in caesium loaded iron phosphate glass. In addition to the above bulk properties, the role of Ba as a network modifier in the structure of iron phosphate glass is examined using various spectroscopic techniques. The FeII content and average coordination number of iron in the glass network was estimated using Mössbauer spectroscopy. The FeII content in the un-doped iron phosphate glass and barium doped iron phosphate glasses was 20, 21 and 22 ± 1% respectively and the average Fe coordination varied from 5.3 ± 0.2 to 5.7 ± 0.2 with increasing Ba content. The atomic scale structure was further probed by Fe K-edge X-ray absorption spectroscopy. The average coordination number provided by extended X-ray absorption fine structure spectroscopy and X-ray absorption near edge structure was in good agreement with that given by the Mössbauer data.

  11. Fabrication of optical fiber of zinc tin borophosphate glass with zero photoelastic constant

    Science.gov (United States)

    Saitoh, Akira; Oba, Yuya; Takebe, Hiromichi

    2015-10-01

    An optical fiber made of zinc tin boro-phosphate glass having a zero photoelastic constant, good water durability, and excluding hazardous elements was drawn from a prepared preform for use in a fiber-type current sensor device. The proposed cladding compositions enable single-mode propagation for a wavelength of 1550 nm, which is estimated from the difference in the refractive index between the core and cladding compositions. The drawing conditions should be controlled since the multiple-component glass is very sensitive to changes in viscosity and crystal precipitation during the heat-treated stretching of the preform. The temperature dependence of viscosity in the core and cladding reveals the feasibility of drawing.

  12. Characterization of iron phosphate glasses prepared by microwave heating

    International Nuclear Information System (INIS)

    Almeida, Fabio Jesus Moreira de

    2006-01-01

    Phosphate glasses have been investigated since the fifties, because they are relatively easy to prepare, have low melting temperatures (1000 deg C - 1200 deg C and low glass transition. However, these glasses were very sensitive to humidity, showing a very low chemical durability. Iron phosphate glasses have been prepared by melting inorganic precursors in conventional electric furnaces and induction furnaces. By adding iron, phosphate glasses became chemical resistant and were thought to be used as nuclear waste forms or mechanical resistance fibers. The use of microwaves has been investigated because it makes possible a fast and homogeneous heating of the materials. Microwave promotes the self-heating of the material by the interaction of the external electromagnetic field with the molecules and ions of the material. Niobium phosphate glasses was also produced already through the heating of precursors in microwave ovens. Other glasses containing iron in theirs structure was produced by conventional furnaces and they had your structures analyzed. But even so, it was not still published synthesis of iron phosphate glasses starting from the melting of precursors materials in microwave ovens. In the present work mixtures of (NH 4 ) 2 HPO 4 and Fe 3 O 4 or (NH 4 ) 2 HPO 4 and Fe 2 O 3 were exposed to microwave energy with electromagnetic waves of 2,45 GHz. It was proposed that the absorption of this radiation for the material causes the heating from room temperature to melting temperature. The obtained iron phosphate glasses was analyzed by X-ray diffraction, Moessbauer spectroscopy, and Differential Thermal Analysis. Iron phosphate glasses were also produced in electrical furnaces for comparison. (author)

  13. Characterization of iron phosphate glasses prepared by microwave heating

    International Nuclear Information System (INIS)

    Almeida, Fabio Jesus Moreira de

    2006-01-01

    Phosphate glasses have been investigated since the fifties, because they are relatively easy to prepare, have low melting temperatures (1000 deg C - 1200 deg C), and low glass transition. However, these glasses were very sensitive to humidity, showing a very low chemical durability. Iron phosphate glasses have been prepared by melting inorganic precursors in conventional electric furnaces and induction furnaces. By adding iron, phosphate glasses became chemical resistant and were thought to be used as nuclear waste forms or mechanical resistance fibers. The use of microwaves has been investigated because it makes possible a fast and homogeneous heating of the materials. Microwave promotes the self-heating of the material by the interaction of the external electromagnetic field with the molecules and ions of the material. Niobium phosphate glasses was also produced already through the heating of precursors in microwave ovens. Other glasses containing iron in theirs structure was produced by conventional furnaces and they had your structures analyzed. But even so, it was not still published synthesis of iron phosphate glasses starting from the melting of precursors materials in microwave ovens. In the present work mixtures of (NH 4 ) 2 HPO 4 and Fe 3 O 4 or (NH 4 ) 2 HPO 4 and Fe 2 O 3 were exposed to microwave energy with electromagnetic waves of 2,45 GHz. It was proposed that the absorption of this radiation for the material causes the heating from room temperature to melting temperature. The obtained iron phosphate glasses was analyzed by X-ray diffraction, Moessbauer spectroscopy, and Differential Thermal Analysis. Iron phosphate glasses were also produced in electrical furnaces for comparison. (author)

  14. Zinc-Nickel Codeposition in Sulfate Solution Combined Effect of Cadmium and Boric Acid

    Directory of Open Access Journals (Sweden)

    Y. Addi

    2011-01-01

    Full Text Available The combined effect of cadmium and boric acid on the electrodeposition of zinc-nickel from a sulfate has been investigated. The presence of cadmium ion decreases zinc in the deposit. In solution, cadmium inhibits the zinc ion deposition and suppresses it when deposition potential value is more negative than −1.2 V. Low concentration of CdSO4 reduces the anomalous nature of Zn-Ni deposit. Boric acid decreases current density and shifts potential discharge of nickel and hydrogen to more negative potential. The combination of boric acid and cadmium increases the percentage of nickel in the deposit. Boric acid and cadmium.

  15. Benefits and drawbacks of zinc in glass ionomer bone cements

    International Nuclear Information System (INIS)

    Brauer, Delia S; Hill, Robert G; Gentleman, Eileen; Stevens, Molly M; Farrar, David F

    2011-01-01

    Glass polyalkenoate (ionomer) cements (GPCs) based on poly(acrylic acid) and fluoro-alumino-silicate glasses are successfully used in a variety of orthopaedic and dental applications; however, they release small amounts of aluminium, which is a neurotoxin and inhibits bone mineralization in vivo. Therefore there has been significant interest in developing aluminium-free glasses containing zinc for forming GPCs because zinc can play a similar structural role in the glass, allowing for glass degradation and subsequent cement setting, and is reported to have beneficial effects on bone formation. We created zinc-containing GPCs and characterized their mechanical properties and biocompatibility. Zinc-containing cements showed adhesion to bone close to 1 MPa, which was significantly greater than that of zinc-free cements ( 2+ or more resulted in cell death. In summary, we demonstrate that while zinc-containing GPCs possess excellent mechanical properties, they fail basic biocompatibility tests, produce an acute cytotoxic response in vitro, which may preclude their use in vivo.

  16. Electrodeposited zinc/nickel coatings. A review

    Energy Technology Data Exchange (ETDEWEB)

    Shoeib, Madiha A. [Central Metallurgical Research and Development Institute (CMRDI), Helwan, Cairo (Egypt). Surface Coating Dept.

    2011-10-15

    In recent years, the use of electrodeposited zinc-nickel coatings has significantly increased, mainly because of their superior corrosion resistance as compared with zinc. An additional strength of the process is that the proportion of the two metals, and thus the coating properties, can be varied. Initially, these alloy deposits were relatively brittle, with a tendency to crack-formation. More recently, ductile coatings have been developed. Now, as in the past, the emphasis has been on the cathodic corrosion protection which these coatings provide. Their properties can be further enhanced by post-treatment where additional developments have taken place. (orig.)

  17. Structural and luminescence properties of Mn2+ ions doped calcium zinc borophosphate glasses

    International Nuclear Information System (INIS)

    Wan, Ming Hua; Wong, Poh Sum; Hussin, Rosli; Lintang, Hendrik O.; Endud, Salasiah

    2014-01-01

    Highlights: • FT-IR revealed that the network structures are from borate and phosphate network. • The PL spectrum exhibits a green emission band at 582 nm ( 4 T 1g → 6 A 1g ). • As the concentration of Mn 2+ ions is increased, the emission band had been red shifted. • These glasses are found to have potential applications as luminescent optical materials. - Abstract: Calcium zinc borophosphate glasses (CaZnBP) doped with various concentrations of Mn 2+ ions and borate and phosphate as variable were prepared using conventional melt quenching technique. The structure of obtained glasses were examined by means of use: X-ray diffraction (XRD) and fourier transform infrared (FT-IR). XRD analysis confirmed amorphous nature of glass samples. The FT-IR spectra reveals the presence of both borate and phosphate vibrational modes in the prepared glasses. The doping of Mn 2+ ions (2–10 mol%) shows no significant changes in the main IR vibrational bands. Optical properties were studied by measuring the near infrared photoluminescence (PL) spectra. CaZnBP glasses exhibited intense green emission peak (582 nm) (tetrahedral symmetry), which is assigned to a transition from the upper 4 T 1g → 6 A 1g ground state of Mn 2+ ions. As the concentration of Mn 2+ ions increases, the emission band increases from 582 nm to 650 nm and exhibited a red light emission (octahedral symmetry). The decay curves of 4 T 1g level were examined for all concentrations and the measured lifetimes are found to depend strongly on Mn 2+ concentrations. From the emission characteristic parameters of 6 A 1g (S) level, it shows that the CaZnBP glasses could have potential applications as luminescent optical materials, visible lasers and fluorescent display devices

  18. Benefits and drawbacks of zinc in glass ionomer bone cements

    Energy Technology Data Exchange (ETDEWEB)

    Brauer, Delia S; Hill, Robert G [Unit of Dental Physical Sciences, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); Gentleman, Eileen; Stevens, Molly M [Department of Materials, Imperial College London, Exhibition Road, London SW7 2AZ (United Kingdom); Farrar, David F, E-mail: d.brauer@qmul.ac.uk [Smith and Nephew Research Centre, York Science Park, Heslington YO10 5DF (United Kingdom)

    2011-08-15

    Glass polyalkenoate (ionomer) cements (GPCs) based on poly(acrylic acid) and fluoro-alumino-silicate glasses are successfully used in a variety of orthopaedic and dental applications; however, they release small amounts of aluminium, which is a neurotoxin and inhibits bone mineralization in vivo. Therefore there has been significant interest in developing aluminium-free glasses containing zinc for forming GPCs because zinc can play a similar structural role in the glass, allowing for glass degradation and subsequent cement setting, and is reported to have beneficial effects on bone formation. We created zinc-containing GPCs and characterized their mechanical properties and biocompatibility. Zinc-containing cements showed adhesion to bone close to 1 MPa, which was significantly greater than that of zinc-free cements (<0.05 MPa) and other currently approved biological adhesives. However, zinc-containing cements produced significantly lower metabolic activity in mouse osteoblasts exposed to cell culture medium conditioned with the cements than controls. Results show that although low levels of zinc may be beneficial to cells, zinc concentrations of 400 {mu}M Zn{sup 2+} or more resulted in cell death. In summary, we demonstrate that while zinc-containing GPCs possess excellent mechanical properties, they fail basic biocompatibility tests, produce an acute cytotoxic response in vitro, which may preclude their use in vivo.

  19. Ultraviolet optical absorptions of semiconducting copper phosphate glasses

    Science.gov (United States)

    Bae, Byeong-Soo; Weinberg, Michael C.

    1993-01-01

    Results are presented of a quantitative investigation of the change in UV optical absorption in semiconducting copper phosphate glasses with batch compositions of 40, 50, and 55 percent CuO, as a function of the Cu(2+)/Cu(total) ratio in the glasses for each glass composition. It was found that optical energy gap, E(opt), of copper phosphate glass is a function of both glass composition and Cu(2+)/Cu(total) ratio in the glass. E(opt) increases as the CuO content for fixed Cu(2+)/Cu(total) ratio and the Cu(2+)/Cu(total) ratio for fixed glass composition are reduced.

  20. Chromium, Nickel and Zinc Induced Histopathological Alterations in ...

    African Journals Online (AJOL)

    Michael Horsfall

    fish, Labeo rohita to chlorides of chromium, nickel and zinc for 30 days. However ... toxicants such as salts of heavy metals, acids, organic matter ... nutritional supply becomes excessive. ... action), petrochemicals, and fertilizers and in steam.

  1. Investigation of lead-iron-phosphate glass for SRP waste

    International Nuclear Information System (INIS)

    Jantzen, C.M.

    1986-10-01

    The search for a host solid for the immobilization of nuclear waste has focused on various vitreous waste forms. Recently, lead-iron-phosphate (LIP) glasses have been proposed for solidification of all types of HLLW. Investigation of this glass for vitrification of SRP waste demonstrated that the phosphate glass is incompatible with the current borosilicate glass technology. The durability of LIP glasses in deionized water was comparable to current borosilicate waste glass formulations, and the LIP glass has a low melt temperature. However, many of the defense waste constituents have low solubility in the phosphate melt, producing an inhomogeneous product. Also, the LIP melt is highly corrosive which prevents the use of current melter materials, in particular Inconel 690, and thus requires more exotic materials of construction such as platinum

  2. Theoretical Studies of the Spin Hamiltonian Parameters and Local Distortions for Cu2+ in Alkaline Earth Lead Zinc Phosphate Glasses

    Science.gov (United States)

    Wang, Bo-Kun; Wu, Shao-Yi; Yuan, Zi-Yi; Liu, Zi-Xuan; Jiang, Shi-Xin; Liu, Zheng; Yao, Zi-Jian; Teng, Bao-Hua; Wu, Ming-He

    2016-08-01

    The spin Hamiltonian parameters and local structures are theoretically studied for Cu2+-doped alkaline earth lead zinc phosphate (RPPZ, R=Mg, Ca, Sr, and Ba) glasses based on the high-order perturbation calculations for a tetragonally elongated octahedral 3d9 cluster. The relative elongation ratios are found to be ρ≈3.2%, 4.4%, 4.6%, and 3.3% for R=Mg, Ca, Sr, and Ba, respectively, because of the Jahn-Teller effect. The whole decreasing crystal-field strength Dq and orbital reduction factor k from Mg to Sr are ascribed to the weakening electrostatic coulombic interactions and the increasing probability of productivity of nonbridge oxygen (and hence increasing Cu2+-O2- electron cloud admixtures) under PbO addition, respectively, with increasing alkali earth ionic radius. The anomalies (the largest Dq and the next highest k among the systems) for R=Ba are attributed to the cross linkage of this large cation in the network. The overall increasing order (Mg≤Bacontaining copper dopants.

  3. The electrical properties of semiconducting vanadium phosphate glasses

    International Nuclear Information System (INIS)

    Moridi, G.R.; Hogarth, C.A.; Hekmat Shooar, N.H.

    1984-01-01

    Vanadium phosphate glasses are a group of oxide glasses which show the semiconducting behaviour. In contrast to the conventional glasses, the conduction mechanism in these glasses is electronic, rather than being ionic. Since 1954, when the first paper appeared on the semiconducting properties of these glasses, much work has been carried out on transition-metal-oxide glasses in general, and vanadium phosphate glasses in particular. The mechanism of conduction is basicaly due to the transport of electrons between the transition-metal ions in different valency states. In the present paper, we have reviewed the previous works on the electrical characteristics of P 2 O 5 -V 2 O 5 glasses and also discussed the current theoretical ideas relevant for the interpretation of the experimental data

  4. Magnesium-phosphate-glass cements with ceramic-type properties

    Science.gov (United States)

    Sugama, T.; Kukacka, L.E.

    1982-09-23

    Rapid setting magnesium phosphate (Mg glass) cementitious materials consisting of magnesium phosphate cement paste, polyborax and water-saturated aggregate, exhibits rapid setting and high early strength characteristics. The magnesium glass cement is prepared from a cation-leachable powder and a bivalent metallic ion-accepting liquid such as an aqueous solution of diammonium phosphate and ammonium polyphosphate. The cation-leachable powder includes a mixture of two different magnesium oxide powders processed and sized differently which when mixed with the bivalent metallic ion-accepting liquid provides the magnesium glass cement consisting primarily of magnesium ortho phosphate tetrahydrate, with magnesium hydroxide and magnesium ammonium phosphate hexahydrate also present. The polyborax serves as a set-retarder. The resulting magnesium mono- and polyphosphate cements are particularly suitable for use as a cementing matrix in rapid repair systems for deteriorated concrete structures as well as construction materials and surface coatings for fireproof structures.

  5. Magnesium phosphate glass cements with ceramic-type properties

    Science.gov (United States)

    Sugama, Toshifumi; Kukacka, Lawrence E.

    1984-03-13

    Rapid setting magnesium phosphate (Mg glass) cementitious materials consisting of magnesium phosphate cement paste, polyborax and water-saturated aggregate exhibiting rapid setting and high early strength characteristics. The magnesium glass cement is prepared from a cation-leachable powder and a bivalent metallic ion-accepting liquid such as an aqueous solution of diammonium phosphate and ammonium polyphosphate. The cation-leachable powder includes a mixture of two different magnesium oxide powders processed and sized differently which when mixed with the bivalent metallic ion-accepting liquid provides the magnesium glass cement consisting primarily of magnesium ortho phosphate tetrahydrate, with magnesium hydroxide and magnesium ammonium phosphate hexahydrate also present. The polyborax serves as a set-retarder. The resulting magnesium mono- and polyphosphate cements are particularly suitable for use as a cementing matrix in rapid repair systems for deteriorated concrete structures as well as construction materials and surface coatings for fireproof structures.

  6. Radiophotoluminescence from silver-doped phosphate glass

    International Nuclear Information System (INIS)

    Miyamoto, Y.; Takei, Y.; Nanto, H.; Kurobori, T.; Konnai, A.; Yanagida, T.; Yoshikawa, A.; Shimotsuma, Y.; Sakakura, M.

    2011-01-01

    Glass dosimeter utilizing radiophotoluminescence (RPL) is one of accumulation type solid state dosimeters, which is based on luminescence phenomenon of silver (Ag + ions)-doped phosphate glass exposed to ionizing radiation. In this study, to clarify the emission mechanism of yellow and blue RPL peaks, optical properties of Ag + -doped glass, such as optical absorption spectrum, RPL excitation spectrum before and after X-ray irradiation as well as the lifetime of both RPL peaks are measured. From the results, we discuss the emission mechanism of yellow (peaked at 2.21 eV) and blue (peaked at 2.70 eV) RPL using a proposed energy band diagram for RPL emission and excitation in Ag + -doped phosphate glass. It is found that the radiative lifetime of blue RPL is three orders of magnitude faster than that of yellow RPL.

  7. Langmuir Isotherm application to the competitive adsorption of Cadmium, Nickel and Zinc on a Bentonite

    International Nuclear Information System (INIS)

    Silva Giraldo, German Dario; Pinzon Bello, Jorge Alejo

    1999-01-01

    In the present work, it was studied the simultaneous adsorption of binary and ternary mixtures of cadmium, nickel and zinc ions in aqueous solution at 25oC over a bentonite from the Cauca Valley, in its native state as well as in its sodium homo ionic form. The Langmuir isotherm, initially introduced by Murali and Aylmore for the competitive adsorption of various adsorbents, adequately describes the simultaneous adsorption of the three ions over the studied bentonite. The lineal correlation coefficient is greater than 0.900 in the major part of the systems. The competitive effect was interpreted by means of the thermodynamic distribution coefficient, Kdm. The degree of adsorption in the binary mixtures is nickel > zinc, cadmium over the natural bentonite, and nickel > cadmium > zinc over the sodium homo ionic form, whereas in the ternary mixture the order Nickel > Cadmium > Zinc is found over both adsorbents

  8. Research, development and demonstration of nickel-zinc batteries for electric vehicle propulsion. Annual report for 1978

    Energy Technology Data Exchange (ETDEWEB)

    1979-10-01

    This is the first annual report describing progress in the 33-month cooperative program between Argonne National Laboratory and Gould Inc.'s Nickel-Zinc/Electric Vehicle Project. The purpose of the program is to demonstrate the technical and economic feasibility of the nickel-zinc battery for electric vehicle propulsion. The successful completion of the program will qualify the nickel-zinc battery for use in the Department of Energy's demonstration program under the auspices of Public Law 94-413.

  9. Chromium, Nickel and Zinc Levels from Canned and Non-Canned ...

    African Journals Online (AJOL)

    Heavy metals (Chromium, Nickel and Zinc) were determined from both canned and non-canned beverages sold in Samaru, Zaria, Kaduna State, Nigeria. Concentration of Chromium was found to range from 0.528 - 1.509mg/L for canned and 0.176 - 1.358mg/L for non-canned beverages, Nickel concentration was found to ...

  10. Lithium-aluminum-zinc phosphate glasses activated with Tb3+ and Tb3+/Eu3+ for green laser medium, reddish-orange and white phosphor applications

    Science.gov (United States)

    Francisco-Rodriguez, H. I.; Lira, A.; Soriano-Romero, O.; Meza-Rocha, A. N.; Bordignon, S.; Speghini, A.; Lozada-Morales, R.; Caldiño, U.

    2018-05-01

    A spectroscopic analysis of Tb3+ and Tb3+/Eu3+ doped lithium-aluminum-zinc phosphate glasses is performed through their absorbance and photoluminescence spectra, and decay time profiles. Laser parameter values (stimulated emission cross section, effective bandwidth, gain bandwidth and optical gain) were obtained for the terbium 5D4 → 7F5 green emission from the Tb3+ singly-doped glass (LAZT) excited at 350 nm to judge the suitability of the glass phosphor for fiber lasers. A quantum yield of (47.68 ± 0.49)% was measured for the 5D4 level luminescence. Upon 350 nm excitation the LAZT glass phosphor emits green light with a color purity of 65.6% and chromaticity coordinates (0.285, 0.585) very close to those (0.29, 0.60) of European Broadcasting Union illuminant green. The Tb3+/Eu3+codoped glass emission color can be tuned from reddish-orange of 1865 K upon 318 nm excitation to warm white of 3599 K and neutral white of 4049 K upon 359 and 340 nm excitations, respectively. Upon Tb3+ excitation at 340 nm Eu3+ is sensitized by Tb3+ through a non-radiative energy transfer with an efficiency of 0.23-0.26. An electric dipole-dipole interaction might be the dominant mechanism in the Tb3+ to Eu3+ energy transfer taking place into Tb3+ - Eu3+ clusters.

  11. THE EFFECT OF SINGLE NICKEL AND COMBINED NICKEL AND ZINC PERORAL ADMINISTRATION ON HAEMATOLOGICAL PARAMETERS IN RABBITS

    Directory of Open Access Journals (Sweden)

    Jana Emrichová

    2013-06-01

    Full Text Available The aim of this study was to determine the effect of single nickel (NiCl2 and nickel in combination with zinc (ZnCl2 on selected haematological parameters of rabbits: white blood cell, red blood cell, haemoglobin, haematocrit, mean corpuscular volume, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration, platelets, mean platelet volume, red cell distribution width, lymphocytes, monocytes, eosinophils, neutrophils, basophils. Twenty rabbits of broiler line Californian were used in this experiment. The animals were divided into the five groups, four animals in each ones (control group K and experimental groups E1, E2, E3 and E4. Animals were fed ad libitum using KKV1 feeding mixture (FM with or without nickel and zinc addition for 90 days follows: group E1 received 17.5 g of NiCl2.100 kg-1 FM; group E2 35 g NiCl2.100 kg-1 FM; group E3 17.5 g NiCl2 + 30 g ZnCl2.100 kg-1 FM and group E4 35 g NiCl2 + 30 g ZnCl2.100 kg-1 FM. The parameters were analysed using Advia – 120. Blood was collected into tubes containing anticoagulant agents K – EDTA. Statistical analyse showed a significant changes (P 0.05. Nickel has negative effect on some haematological parameters, but zinc can eliminates its influence.

  12. Wustite-based photoelectrodes with lithium, hydrogen, sodium, magnesium, manganese, zinc and nickel additives

    Science.gov (United States)

    Carter, Emily Ann; Toroker, Maytal Caspary

    2017-08-15

    A photoelectrode, photovoltaic device and photoelectrochemical cell and methods of making are disclosed. The photoelectrode includes an electrode at least partially formed of FeO combined with at least one of lithium, hydrogen, sodium, magnesium, manganese, zinc, and nickel. The electrode may be doped with at least one of lithium, hydrogen, and sodium. The electrode may be alloyed with at least one of magnesium, manganese, zinc, and nickel.

  13. Nickel/zinc-catalyzed decarbonylative addition of anhydrides to alkynes: a DFT study.

    Science.gov (United States)

    Meng, Qingxi; Li, Ming

    2013-10-01

    Density functional theory (DFT) was used to investigate the nickel- or nickel(0)/zinc- catalyzed decarbonylative addition of phthalic anhydrides to alkynes. All intermediates and transition states were optimized completely at the B3LYP/6-31+G(d,p) level. Calculated results indicated that the decarbonylative addition of phthalic anhydrides to alkynes was exergonic, and the total free energy released was -87.6 kJ mol(-1). In the five-coordinated complexes M4a and M4b, the insertion reaction of alkynes into the Ni-C bond occurred prior to that into the Ni-O bond. The nickel(0)/zinc-catalyzed decarbonylative addition was much more dominant than the nickel-catalyzed one in whole catalytic decarbonylative addition. The reaction channel CA→M1'→T1'→M2'→T2'→M3a'→M4a'→T3a1'→M5a1' →T4a1'→M6a'→P was the most favorable among all reaction pathways of the nickel- or nickel(0)/zinc- catalyzed decarbonylative addition of phthalic anhydrides to alkynes. And the alkyne insertion reaction was the rate-determining step for this channel. The additive ZnCl2 had a significant effect, and it might change greatly the electron and geometry structures of those intermediates and transition states. On the whole, the solvent effect decreased the free energy barriers.

  14. Improvement of acid and base resistance of nickel phosphate pigment by the addition of lanthanum cation

    International Nuclear Information System (INIS)

    Onoda, Hiroaki; Matsui, Hironori; Tanaka, Isao

    2007-01-01

    Transition metal phosphates are used as inorganic pigments, however these materials had a weak point for acid and base resistance. Because lanthanum phosphate is insoluble in acidic and basic solution, the addition of lanthanum cation was tried for the improvement of the acid and base resistance of nickel phosphate pigment. The lanthanum-doped nickel phosphates were prepared from phosphoric acid, nickel nitrate, and lanthanum nitrate solution. The additional effects of lanthanum cation were studied on the chemical composition, particle shape and size distribution, specific surface area, color, acid and base resistance of the precipitations and their thermal products

  15. Structure determination of electrodeposited zinc-nickel alloys: thermal stability and quantification using XRD and potentiodynamic dissolution

    International Nuclear Information System (INIS)

    Fedi, B.; Gigandet, M.P.; Hihn, J-Y; Mierzejewski, S.

    2016-01-01

    Highlights: • Quantification of zinc-nickel phases between 1,2% and 20%. • Coupling XRD to partial potentiodynamic dissolution. • Deconvolution of anodic stripping curves. • Phase quantification after annealing. - Abstract: Electrodeposited zinc-nickel coatings obtained by electrodeposition reveal the presence of metastable phases in various quantities, thus requiring their identification, a study of their thermal stability, and, finally, determination of their respective proportions. By combining XRD measurement with partial potentiodynamic dissolution, anodic peaks were indexed to allow their quantification. Quantification of electrodeposited zinc-nickel alloys approximately 10 μm thick was thus carried out on nickel content between 1.2% and 20%, and exhibited good accuracy. This method was then extended to the same set of alloys after annealing (250 °C, 2 h), thus bringing the structural organization closer to its thermodynamic equilibrium. The result obtained ensures better understanding of crystallization of metastable phases and of phase proportion evolution in a bi-phasic zinc-nickel coating. Finally, the presence of a monophase γ and its thermal stability in the 12% to 15% range provides important information for coating anti-corrosion behavior.

  16. Nickel hydrogen and silver zinc battery cell modeling at the Aerospace Corporation

    Energy Technology Data Exchange (ETDEWEB)

    Zimmerman, A.H.

    1996-02-01

    A nickel hydrogen battery cell model has been fully developed and implemented at The Aerospace Corporation. Applications of this model to industry needs for the design of better cells, power system design and charge control thermal management, and long-term performance trends will be described. Present efforts will be described that are introducing the silver and zinc electrode reactions into this model architecture, so that the model will be able to predict performance for not only silver zinc cells, but also nickel zinc, silver hydrogen, and silver cadmium cells. The silver zinc cell modeling effort is specifically designed to address the concerns that arise most often in launch vehicle applications: transient response, power-on voltage regulation, hot or cold operation, electrolyte spewing, gas venting, self-discharge, separator oxidation, and oxalate crystal growth. The specific model features that are being employed to address these issues will be described.

  17. Optical, physical and structural studies of boro-zinc tellurite glasses

    International Nuclear Information System (INIS)

    Gayathri Pavani, P.; Sadhana, K.; Chandra Mouli, V.

    2011-01-01

    To investigate the modification effect of the modifier ZnO on boro-tellurite glass, a series of glasses with compositions 50B 2 O 3 -(50-x)ZnO-xTeO 2 have been prepared by conventional melt quenching technique. Amorphous nature of the samples was confirmed through X-ray diffraction technique. Optical absorption and IR structural studies are carried out on the glass system. The optical absorption studies revealed that the cutoff wavelength increases while optical band gap (E opt ) and Urbach energy decreases with an increase of ZnO content. Refractive index evaluated from E opt was found to increase with an increase of ZnO content. The compositional dependence of different physical parameters such as density, molar volume, oxygen packing density, optical basicity, have been analyzed and discussed. The IR studies showed that the structure of glass consists of TeO 4 , TeO 3 /TeO 3+1 , BO 3 , BO 4 and ZnO 4 units. -- Research highlights: → Novel boro-zinc tellurite ternary glasses that can compete with boro-tellurite and zinc tellurite glasses are successfully prepared. → Boro-zinc tellurite ternary glasses are of higher refractive index compared with zinc tellurite glasses. → Optical, physical and structural properties of the novel ternary glass system are explained.→ At 30 mol% of ZnO, TeO 4 is replaced by ZnO 4 indicating the presence of ZnO 4 network.

  18. Rechargeable nickel-3D zinc batteries: An energy-dense, safer alternative to lithium-ion.

    Science.gov (United States)

    Parker, Joseph F; Chervin, Christopher N; Pala, Irina R; Machler, Meinrad; Burz, Michael F; Long, Jeffrey W; Rolison, Debra R

    2017-04-28

    The next generation of high-performance batteries should include alternative chemistries that are inherently safer to operate than nonaqueous lithium-based batteries. Aqueous zinc-based batteries can answer that challenge because monolithic zinc sponge anodes can be cycled in nickel-zinc alkaline cells hundreds to thousands of times without undergoing passivation or macroscale dendrite formation. We demonstrate that the three-dimensional (3D) zinc form-factor elevates the performance of nickel-zinc alkaline cells in three fields of use: (i) >90% theoretical depth of discharge (DOD Zn ) in primary (single-use) cells, (ii) >100 high-rate cycles at 40% DOD Zn at lithium-ion-commensurate specific energy, and (iii) the tens of thousands of power-demanding duty cycles required for start-stop microhybrid vehicles. Copyright © 2017, American Association for the Advancement of Science.

  19. Structural and luminescence properties of Mn{sup 2+} ions doped calcium zinc borophosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Wan, Ming Hua, E-mail: wanminghua819@gmail.com [Phosphor Research Group, Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, Skudai 81310, Johor (Malaysia); Wong, Poh Sum, E-mail: pohsumwong@gmail.com [Phosphor Research Group, Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, Skudai 81310, Johor (Malaysia); Hussin, Rosli, E-mail: roslihussin@utm.my [Phosphor Research Group, Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, Skudai 81310, Johor (Malaysia); Lintang, Hendrik O., E-mail: hendrik@ibnusina.utm.my [Catalytic Science and Technology (CST) Research Group, Ibnu Sina Institute for Fundamental Science Studies, Universiti Teknologi Malaysia, Skudai 81310, Johor (Malaysia); Endud, Salasiah, E-mail: salasiah@kimia.fs.utm.my [Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor (Malaysia)

    2014-05-15

    Highlights: • FT-IR revealed that the network structures are from borate and phosphate network. • The PL spectrum exhibits a green emission band at 582 nm ({sup 4}T{sub 1g} → {sup 6}A{sub 1g}). • As the concentration of Mn{sup 2+} ions is increased, the emission band had been red shifted. • These glasses are found to have potential applications as luminescent optical materials. - Abstract: Calcium zinc borophosphate glasses (CaZnBP) doped with various concentrations of Mn{sup 2+} ions and borate and phosphate as variable were prepared using conventional melt quenching technique. The structure of obtained glasses were examined by means of use: X-ray diffraction (XRD) and fourier transform infrared (FT-IR). XRD analysis confirmed amorphous nature of glass samples. The FT-IR spectra reveals the presence of both borate and phosphate vibrational modes in the prepared glasses. The doping of Mn{sup 2+} ions (2–10 mol%) shows no significant changes in the main IR vibrational bands. Optical properties were studied by measuring the near infrared photoluminescence (PL) spectra. CaZnBP glasses exhibited intense green emission peak (582 nm) (tetrahedral symmetry), which is assigned to a transition from the upper {sup 4}T{sub 1g} → {sup 6}A{sub 1g} ground state of Mn{sup 2+} ions. As the concentration of Mn{sup 2+} ions increases, the emission band increases from 582 nm to 650 nm and exhibited a red light emission (octahedral symmetry). The decay curves of {sup 4}T{sub 1g} level were examined for all concentrations and the measured lifetimes are found to depend strongly on Mn{sup 2+} concentrations. From the emission characteristic parameters of {sup 6}A{sub 1g} (S) level, it shows that the CaZnBP glasses could have potential applications as luminescent optical materials, visible lasers and fluorescent display devices.

  20. Characterization of Fe -doped silver phosphate glasses

    Indian Academy of Sciences (India)

    ... to their several spe- cial properties such as large thermal expansion coefficients, ... increase the conductivity of these glasses is to increase the modifier or dopant ... phosphate glasses were measured by the a.c. impedance spectroscopic .... and Fe2O3-doped Ag2O–P2O5 glasses were determined from. DSC curves and ...

  1. Research, development and demonstration of nickel-zinc batteries for electric vehicle propulsion. Annual report, 1978

    Energy Technology Data Exchange (ETDEWEB)

    1979-10-01

    The work carried out under the Yardney Contract with ANL for R, D and D on nickel zinc batteries over the past year was directed in three major areas: (1) elucidating the failure modes of the nickel-zinc battery system; (2) improving performance of the system; and (3) effecting a cost reduction program. Progress on the three areas is reported. (TFD)

  2. Theoretical studies of the spin Hamiltonian parameters and local distortions for Cu{sup 2+} in alkaline earth lead zinc phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Bo-Kun; Yuan, Zi-Yi; Liu, Zi-Xuan; Jiang, Shi-Xin; Liu, Zheng; Yao, Zi-Jian [University of Electronic Science and Technology of China, Chengdu (China). School of Yingcai Honors; Wu, Shao-Yi; Teng, Bao-Hua; Wu, Ming-He [University of Electronic Science and Technology of China, Chengdu (China). Dept. of Applied Physics

    2016-11-01

    The spin Hamiltonian parameters and local structures are theoretically studied for Cu{sup 2+}-doped alkaline earth lead zinc phosphate (RPPZ, R=Mg, Ca, Sr, and Ba) glasses based on the high-order perturbation calculations for a tetragonally elongated octahedral 3d{sup 9} cluster. The relative elongation ratios are found to be ρ ∼ 3.2%, 4.4%, 4.6%, and 3.3% for R=Mg, Ca, Sr, and Ba, respectively, because of the Jahn-Teller effect. The whole decreasing crystal-field strength Dq and orbital reduction factor k from Mg to Sr are ascribed to the weakening electrostatic coulombic interactions and the increasing probability of productivity of nonbridge oxygen (and hence increasing Cu{sup 2+}-O{sup 2-} electron cloud admixtures) under PbO addition, respectively, with increasing alkali earth ionic radius. The anomalies (the largest Dq and the next highest k among the systems) for R=Ba are attributed to the cross linkage of this large cation in the network. The overall increasing order (Mg≤Baglasses containing copper dopants.

  3. Spectroscopic properties of highly Nd-doped lead phosphate glass

    Energy Technology Data Exchange (ETDEWEB)

    Novais, A.L.F. [Instituto de Física, Universidade Federal de Alagoas, Grupo de Fotônica e Fluidos Complexos, 57072-970 Maceió, AL (Brazil); Dantas, N.O. [Laboratório de Novos Materiais Isolantes e Semicondutores (LNMIS), Instituto de Física, Universidade Federal de Uberlândia, 38400-902 Uberlândia, MG (Brazil); Guedes, I. [Departamento de Física, Universidade Federal do Ceará, Campus do PICI, Caixa Postal 6030, 60455-760 Fortaleza, CE (Brazil); Vermelho, M.V.D., E-mail: vermelho@fis.ufal.br [Instituto de Física, Universidade Federal de Alagoas, Grupo de Fotônica e Fluidos Complexos, 57072-970 Maceió, AL (Brazil)

    2015-11-05

    The spectroscopic characteristics of highly Nd{sup 3+}-doped lead phosphate glasses (xNd:Pb{sub 3}(PO{sub 4}){sub 2}) have been investigated. The X-ray spectra show that the matrices are glassy up to 25 wt% of Nd{sup 3+} doping. From the Judd–Ofelt analysis we observe that while the Ω{sub (2)} parameter remains constant indicating that the 4f{sup N} and 4f{sup N−1}5 d{sup 1} configurations are not affected by the Nd{sup 3+} doping, the behavior of both Ω{sub (4)} and Ω{sub (6)} changes for 15 wt% of Nd{sup 3+} doping. The reduction of the Ω{sub (6)} parameter is related to the increase of the covalence bonding between the ligands and the Nd{sup 3+} ions. At this particular concentration, the radiative lifetime has a four-fold enhancement. Such behaviors are likely to be related to a modification in the glass structure for high Nd{sup 3+} concentrations. - Graphical abstract: Highly doped lead-phosphate glass matrix, with nominal concentration of up to 25 wt%, maintain the spectroscopic properties without deterioration. The analysis concerning the point of view of Nd{sup 3+} ions showed that high concentrations only affects the rare earth electronic charge density distribution. - Highlights: • Spectroscopic characterization of Nd{sub 2}O{sub 3} highly doped lead phosphate glasses. • Phosphate glass doped with Nd{sup 3+} for applications in photonic devices. • Judd–Ofelt analysis in phosphate glasses doped with Neodymium.

  4. Structure and properties of calcium iron phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Qian, Bin [School of Science, Southwest University of Science and Technology, Mianyang 621010 (China); Liang, Xiaofeng, E-mail: xfliangswust@gmail.com [Analytical and Testing Center, Southwest University of Science and Technology, Mianyang 621010 (China); School of Materials Science and Engineering, Southwest University of Science and Technology, Mianyang 621010 (China); Wang, Cuiling; Yang, Shiyuan [School of Materials Science and Engineering, Southwest University of Science and Technology, Mianyang 621010 (China)

    2013-11-15

    The structural properties of xCaO–(100 − x) (0.4Fe{sub 2}O{sub 3}–0.6P{sub 2}O{sub 5}) (x = 0, 10, 20, 30, 40, 50 mol%) glasses have been investigated by XRD, DTA, IR and Raman spectroscopy. XRD analysis has confirmed that the majority of samples are X-ray amorphous, and EDS analysis indicates that the glass matrix can accommodate ≈30 mol% CaO. IR and Raman spectra show that the glass structure consists predominantly of pyrophosphate (Q{sup 1}) units. IR spectra indicate that the phosphate network is depolymerized with the addition of CaO content. The density and glass transition temperature (T{sub g}) increase with increasing CaO content for the glasses. This behavior indicates that the addition of CaO improves the strength of the cross-links between the phosphate chains of the glass.

  5. Structure and spectroscopy of rare earth – Doped lead phosphate glasses

    International Nuclear Information System (INIS)

    Pisarski, Wojciech A.; Żur, Lidia; Goryczka, Tomasz; Sołtys, Marta; Pisarska, Joanna

    2014-01-01

    Highlights: • Lead phosphate glasses doped with rare earth ions were prepared. • The local structure was examined using X-ray diffraction and spectroscopic methods. • Different structural phosphate groups are present in lead phosphate glasses. • The electron–phonon coupling strength and phonon energy of the glass host was determined. • Several observed emission bands are due to 4f–4f electronic transitions of rare earth ions. -- Abstract: Lead–gallium phosphate glasses doped with rare the earth ions (Eu 3+ , Dy 3+ , Tb 3+ , Er 3+ ) were synthesized. The structure of obtained glasses was examined by means of use: X-ray diffraction (XRD), nuclear magnetic resonance ( 207 Pb and 31 P NMR), fourier transform infrared (FT-IR) and Raman spectroscopy. In contrast to fully amorphous Ln-doped samples (Ln = Eu, Dy, Tb), in Er-doped sample the GaPO 4 crystalline phase was identified. It was found from the NMR, FT-IR and Raman spectroscopic techniques that, different structural phosphate groups were present in lead phosphate glasses. Based on absorption measurements, the UV–VIS cut-off wavelength for lead phosphate glass was determined and its value is close to 305 nm. Excitation and emission spectra of rare earths were also detected. From excitation spectra of Eu 3+ the electron–phonon coupling strength and phonon energy of the glass host were determined. Due to 4f 6 –4f 6 (Eu 3+ ), 4f 8 –4f 8 (Tb 3+ ), 4f 9 –4f 9 (Dy 3+ ) and 4f 11 –4f 11 (Er 3+ ) electronic transitions of trivalent rare earth ions several luminescence bands were stated

  6. Communication between the Zinc and Nickel Sites in Dimeric HypA: Metal Recognition and pH Sensing

    Energy Technology Data Exchange (ETDEWEB)

    Herbst, R.; Perovic, I; Martin-Diaconescu, V; O’Brien, K; Chivers, P; Sondej Pochapsky, S; Pochapsky, T; Maroney, M

    2010-01-01

    Helicobacter pylori, a pathogen that colonizes the human stomach, requires the nickel-containing metalloenzymes urease and NiFe-hydrogenase to survive this low pH environment. The maturation of both enzymes depends on the metallochaperone, HypA. HypA contains two metal sites, an intrinsic zinc site and a low-affinity nickel binding site. X-ray absorption spectroscopy (XAS) shows that the structure of the intrinsic zinc site of HypA is dynamic and able to sense both nickel loading and pH changes. At pH 6.3, an internal pH that occurs during acid shock, the zinc site undergoes unprecedented ligand substitutions to convert from a Zn(Cys){sub 4} site to a Zn(His){sub 2}(Cys){sub 2} site. NMR spectroscopy shows that binding of Ni(II) to HypA results in paramagnetic broadening of resonances near the N-terminus. NOEs between the {beta}-CH{sub 2} protons of Zn cysteinyl ligands are consistent with a strand-swapped HypA dimer. Addition of nickel causes resonances from the zinc binding motif and other regions to double, indicating more than one conformation can exist in solution. Although the structure of the high-spin, 5-6 coordinate Ni(II) site is relatively unaffected by pH, the nickel binding stoichiometry is decreased from one per monomer to one per dimer at pH = 6.3. Mutation of any cysteine residue in the zinc binding motif results in a zinc site structure similar to that found for holo-WT-HypA at low pH and is unperturbed by the addition of nickel. Mutation of the histidines that flank the CXXC motifs results in a zinc site structure that is similar to holo-WT-HypA at neutral pH (Zn(Cys){sub 4}) and is no longer responsive to nickel binding or pH changes. Using an in vitro urease activity assay, it is shown that the recombinant protein is sufficient for recovery of urease activity in cell lysate from a HypA deletion mutant, and that mutations in the zinc-binding motif result in a decrease in recovered urease activity. The results are interpreted in terms of a model

  7. Communication between the Zinc and Nickel Sites in Dimeric HypA: Metal Recognition and pH Sensing

    International Nuclear Information System (INIS)

    Herbst, R.; Perovic, I.; Martin-Diaconescu, V.; O'Brien, K.; Chivers, P.; Sondej Pochapsky, S.; Pochapsky, T.; Maroney, M.

    2010-01-01

    Helicobacter pylori, a pathogen that colonizes the human stomach, requires the nickel-containing metalloenzymes urease and NiFe-hydrogenase to survive this low pH environment. The maturation of both enzymes depends on the metallochaperone, HypA. HypA contains two metal sites, an intrinsic zinc site and a low-affinity nickel binding site. X-ray absorption spectroscopy (XAS) shows that the structure of the intrinsic zinc site of HypA is dynamic and able to sense both nickel loading and pH changes. At pH 6.3, an internal pH that occurs during acid shock, the zinc site undergoes unprecedented ligand substitutions to convert from a Zn(Cys) 4 site to a Zn(His) 2 (Cys) 2 site. NMR spectroscopy shows that binding of Ni(II) to HypA results in paramagnetic broadening of resonances near the N-terminus. NOEs between the β-CH 2 protons of Zn cysteinyl ligands are consistent with a strand-swapped HypA dimer. Addition of nickel causes resonances from the zinc binding motif and other regions to double, indicating more than one conformation can exist in solution. Although the structure of the high-spin, 5-6 coordinate Ni(II) site is relatively unaffected by pH, the nickel binding stoichiometry is decreased from one per monomer to one per dimer at pH = 6.3. Mutation of any cysteine residue in the zinc binding motif results in a zinc site structure similar to that found for holo-WT-HypA at low pH and is unperturbed by the addition of nickel. Mutation of the histidines that flank the CXXC motifs results in a zinc site structure that is similar to holo-WT-HypA at neutral pH (Zn(Cys) 4 ) and is no longer responsive to nickel binding or pH changes. Using an in vitro urease activity assay, it is shown that the recombinant protein is sufficient for recovery of urease activity in cell lysate from a HypA deletion mutant, and that mutations in the zinc-binding motif result in a decrease in recovered urease activity. The results are interpreted in terms of a model wherein HypA controls the

  8. A comparative property investigation of lithium phosphate glass

    Indian Academy of Sciences (India)

    The present study addresses the application of microwave (MW) energy for melting lithium phosphate glass. Acomparative analysis of the properties is presented with glasses melted in conventional resistance heating adopting standardmethods of characterization. The density of the glass was found less in MW heating.

  9. Research, development, and demonstration of nickel-zinc batteries for electric vehicle propulsion. Annual report for 1980

    Energy Technology Data Exchange (ETDEWEB)

    1981-03-01

    Progress in the development of nickel-zinc batteries for electric vehicles is reported. Information is presented on nickel electrode preparation and testing; zinc electrode preparation with additives and test results; separator development and the evaluation of polymer-blend separator films; sealed Ni-Zn cells; and the optimization of electric vehicle-type Ni-Zn cells. (LCL)

  10. Electrochemical assessing corrosion inhibiting effects of zinc aluminum polyphosphate (ZAPP) as a modified zinc phosphate pigment

    International Nuclear Information System (INIS)

    Naderi, R.; Attar, M.M.

    2008-01-01

    Undesirable anti-corrosion performance of zinc phosphate pigment, the classical chromate replacement, has led researchers to take modification into account. Polyphosphate-based anti-corrosion pigments as a result of modification of zinc orthophosphate have been found to function much more efficiently. This study aimed to evaluate performance of steel samples immersed in 3.5% NaCl aqueous solution-containing zinc aluminum polyphosphate (ZAPP) pigment extract compared to those involving conventional zinc phosphate (ZP) pigment extract and also no pigment (blank) using electrochemical tests such as electrochemical impedance spectroscopy (EIS) and linear polarization (LP) as well as surface analysis. Impedance spectra and polarization curves revealed two different trends, showing the superiority of ZAPP pigment. Based on the results of scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX), presence of a precipitated layer on the surface was confirmed when steel sample was immersed into the solution-containing ZAPP

  11. High-Strength / High Alkaline Resistant Fe-Phosphate Glass Fibers as Concrete Reinforcement

    Energy Technology Data Exchange (ETDEWEB)

    Mariano Velez

    2008-03-31

    Calcium-iron-phosphate glasses were developed whose chemical durabilities in alkaline solutions (pH 13) were comparable or superior to those of commercial alkaline-resistant (AR) silica-based glasses. However, the tensile strength of Ca-Fe-phosphate fibers, after being exposed to alkaline environments, including wet Portland cement pastes, is lower than that of current AR silicate fibers. Another series of Ca-Fe-phosphate glasses were developed with excellent chemical durability in strong acidic solutions (H2SO4, HF), indicating potential applications where silica-based fibers degrade very quickly, including E-glass. The new Ca-Fe-phosphate glasses can be melted and processed 300 to 500°C lower than silica-based glasses. This offers the possibility of manufacturing glass fibers with lower energy costs by 40-60% and the potential to reduce manufacturing waste and lower gas emissions. It was found that Ca-Fe-phosphate melts can be continuously pulled into fibers depending on the slope of the viscosity-temperature curve and with viscosity ~100 poise, using multi-hole Pt/Rh bushings.

  12. Structure and properties of gadolinium loaded calcium phosphate glasses

    International Nuclear Information System (INIS)

    Wang, Cuiling; Liang, Xiaofeng; Li, Haijian; Yu, Huijun; Li, Zhen; Yang, Shiyuan

    2014-01-01

    The glass samples with composition xGd 2 O 3 –(50 − x)CaO–50P 2 O 5 (0 ⩽ x ⩽ 9 mol%) were prepared by the conventional melt quench method. The structure and properties of gadolinium loaded in calcium phosphate glasses were investigated using XRD, SEM, DTA, IR and Raman spectroscopy. The XRD and SEM analysis for the samples show that the majority of samples are amorphous, and crystallization occurs when the content of Gd 2 O 3 containing is up to 6 mol%. Two main crystalline phases, Ca 2 P 2 O 7 and Gd 3 (P 2 O 7 ) 3 , are embedded in an amorphous matrix. IR and Raman data indicate that glass structure consists of predominantly metaphosphate (Q 2 ) units and the depolymerization of phosphate network with the addition of Gd 2 O 3 . Both the chemical durability and the glass transition temperature (T g ) are improved with the increase of Gd 2 O 3 , which suggests that the Gd acts a role of strengthening the cross-links between the phosphate chains of the glass

  13. Electrochemical evaluation of zinc effect on the corrosion of nickel alloy in PWR solutions with increasing temperature

    International Nuclear Information System (INIS)

    Alvial M, Gaston; Neves, Celia F.C.; Schvartzman, Monica M.A.M.; Quinan, Marco Antonio D.

    2007-01-01

    The main objective for the addition of zinc acetate to the reactor coolant system of PWRs is to effect radiation dose rate reductions. However, zinc is also added as an approach to mitigate the occurrence or severity of primary water stress corrosion cracking of nickel alloy 600. The mechanism by which zinc affects the corrosion of austenitic nickel-base alloys is by incorporation of zinc into the spinel oxide corrosion films. The purpose of this work is to evaluate the influence of zinc on the corrosion behavior of the nickel alloy 600 in PWR chemical environment (1200 ppm B, 2.2 ppm Li, deoxygenated water) with increasing temperature at room pressure. Electrochemical tests (anodic potentiodynamic polarization and electrochemical impedance spectroscopy) were used to characterize the alloy 600. Two conditions were applied: 0 and 100 ppb zinc and the temperature range was 50 - 90 deg C, at ambient pressure. Potentiodynamic polarization was inefficient to present conclusive results. Impedance measurements showed single semicircle in the Nyquist plane suggesting reduction of the charge transference resistance in zinc-containing solutions. This effect is evident at 90 deg C suggesting prejudicial influence of zinc for the alloy 600 at room pressure. (author)

  14. Molecular Dynamics Simulation of the Structure and Properties of Lithium Phosphate Glasses

    Energy Technology Data Exchange (ETDEWEB)

    Liang, J-J; Cygan, R.T.; Alam, T.M.

    1999-07-09

    A new forcefield model was developed for the computer simulation of phosphate materials that have many important applications in the electronics and biomedical industries. The model provides a fundamental basis for the evaluation of phosphate glass structure and thermodynamics. Molecular dynamics simulations of a series of lithium phosphate glass compositions were performed using the forcefield model. A high concentration of three-membered rings (P{sub 3}O{sub 3}) occurs in the glass of intermediate composition (0.2 Li{sub 2}O {center_dot} 0.8P{sub 2}O{sub 5}) that corresponds to the minimum in the glass transition temperature curve for the compositional series. Molecular orbital calculations of various phosphate ring clusters indicate an increasing stabilization of the phosphate ring structure going from two- to four-membered rings.

  15. Structure-solubility relationships in fluoride-containing phosphate based bioactive glasses

    Science.gov (United States)

    Shaharyar, Yaqoot

    The dissolution of fluoride-containing bioactive glasses critically affects their biomedical applications. Most commercial fluoride-releasing bioactive glasses have been designed in the soda-lime-silica system. However, their relatively slow chemical dissolution and the adverse effect of fluoride on their bioactivity are stimulating the study of novel biodegradable materials with higher bioactivity, such as biodegradable phosphate-based bioactive glasses, which can be a viable alternative for applications where a fast release of active ions is sought. In order to design new biomaterials with controlled degradability and high bioactivity, it is essential to understand the connection between chemical composition, molecular structure, and solubility in physiological fluids.Accordingly, in this work we have combined the strengths of various experimental techniques with Molecular Dynamics (MD) simulations, to elucidate the impact of fluoride ions on the structure and chemical dissolution of bioactive phosphate glasses in the system: 10Na2O - (45-x) CaO - 45P2O5 - xCaF2, where x varies between 0 -- 10 mol.%. NMR and MD data reveal that the medium-range atomic-scale structure of thse glasses is dominated by Q2 phosphate units followed by Q1 units, and the MD simulations further show that fluoride tends to associate with network modifier cations to form alkali/alkaline-earth rich ionic aggregates. On a macroscopic scale, we find that incorporating fluoride in phosphate glasses does not affect the rate of apatite formation on the glass surface in simulated body fluid (SBF). However, fluoride has a marked favorable impact on the glass dissolution in deionized water. Similarly, fluoride incorporation in the glasses results in significant weight gain due to adsorption of water (in the form of OH ions). These macroscopic trends are discussed on the basis of the F effect on the atomistic structure of the glasses, such as the F-induced phosphate network re-polymerization, in a

  16. Zinc in calcium phosphate mediates bone induction: in vitro and in vivo model

    NARCIS (Netherlands)

    Luo, Xiaoman; Barbieri, D.; Davison, N.; Yan, Y.; de Bruijn, Joost Dick; Yuan, Huipin

    2014-01-01

    Zinc-containing tricalcium phosphate (Zn-TCP) was synthesized to investigate the role of zinc in osteoblastogenesis, osteoclastogenesis and in vivo bone induction in an ectopic implantation model. Zinc ions were readily released in the culture medium. Zn-TCP with the highest zinc content enhanced

  17. Evaluation of lead-iron-phosphate glass as a high-level waste form

    International Nuclear Information System (INIS)

    Chick, L.A.; Bunnell, L.R.; Strachan, D.M.; Kissinger, H.E.; Hodges, F.N.

    1986-01-01

    The lead-iron-phosphate nuclear waste glass developed at Oak Ridge National Laboratory (ORNL) was evaluated for its potential as an improvement over the current reference waste form, borosilicate glass. Vitreous lead-iron-phosphate glass appears to have substantially better chemical durability than borosilicate glass. However, severe crystallization leading to deteriorated chemical durability would result if this glass were poured into large canisters as is presently done with borosilicate glass. Cesium leach rates from this crystallized material are orders of magnitude greater than those from borosilicate glass. Therefore, in order to realize the performance advantages of the lead-iron-phosphate material in a nuclear waste form, it would be necessary to process it so that it is rapidly cooled, thus retaining its vitreous structure. 22 refs., 4 figs., 4 tabs

  18. Synthesis and characterization of niobium and iron phosphate glasses for U3O8 immobilization

    International Nuclear Information System (INIS)

    Ghussn, Luciana

    2005-01-01

    Niobium and iron phosphate glasses were produced by melting inorganic compound mixtures in electric furnaces and microwave ovens. The chemical durability was compared among niobium phosphate glasses produced by both processes, and equivalent results were obtained. Leaching tests were also performed to compare the chemical durability among monolithic glass blocks and sintered glasses. The glass transition, crystallization and melting temperatures as well the Hruby parameter (K H ) and the activation energy for crystallization were determined from differential thermal analysis of niobium phosphate glasses produced in electric furnaces. Niobium phosphate glasses are thermally more stable (K H =0.82 +- 0.04) than iron phosphate glasses (K H = 0.42 +- 0.03). Sintered glasses were produced from particles with different particle size distributions and sintering temperatures in the range of 720 - 800 deg C for niobium phosphate and 530 - 680 deg C for iron phosphate glasses. The sintering process was suitable because a glass with composition 37P 2 O 5 -23K 2 O-40Nb 2 O 5 showing leaching rate of 10 -6 g.cm -2 .d -1 , 99 % of the monolithic density and none crystalline phases was obtained. This glass only crystallizes itself after re heating at temperatures above 800 deg C , showing two crystalline phases identified as KNb 3 O 8 e K 3 NbP 2 O 9 . The activation energies for crystallization are 496 +- 7 kJ/mol and 513 +- 14 kJ/mol. Niobium phosphate sintered glasses are better densified than sintered iron phosphate glasses. The leaching rate of sintered glasses that show open porosity is higher than monolithic glass blocks. This effect is related to an increase of the surface area associated to open porous and, a correction of the value of the surface area used to calculate the leaching rate is required. A model was proposed based on the surface area of spherical porous to take in account that effect. Even after correcting the surface area, the leaching rates of sintered

  19. A model for phosphate glass topology considering the modifying ion sub-network

    DEFF Research Database (Denmark)

    Hermansen, Christian; Mauro, J.C.; Yue, Yuanzheng

    2014-01-01

    In the present paper we establish a temperature dependent constraint model of alkali phosphate glasses considering the structural and topological role of the modifying ion sub-network constituted by alkali ions and their non-bonding oxygen coordination spheres. The model is consistent with availa......In the present paper we establish a temperature dependent constraint model of alkali phosphate glasses considering the structural and topological role of the modifying ion sub-network constituted by alkali ions and their non-bonding oxygen coordination spheres. The model is consistent...... with available structural data by NMR and molecular dynamics simulation and dynamic data such glass transition temperature (Tg) and liquid fragility (m). Alkali phosphate glasses are exemplary systems for developing constraint model since the modifying cation network plays an important role besides the primary...... phosphate network. The proposed topological model predicts the changing trend of the Tg and m with increasing alkali oxide content for alkali phosphate glasses, including an anomalous minimum at around 20 mol% alkali oxide content. We find that the minimum in Tg and m is caused by increased connectivity...

  20. Development of nano SiO2 incorporated nano zinc phosphate coatings on mild steel

    International Nuclear Information System (INIS)

    Tamilselvi, M.; Kamaraj, P.; Arthanareeswari, M.; Devikala, S.; Selvi, J. Arockia

    2015-01-01

    Highlights: • Nano SiO 2 incorporated nano zinc phosphate coating on mild steel was developed. • Coatings showed enhanced corrosion resistance. • The nano SiO 2 is adsorbed on mild steel surface and become nucleation sites. • The nano SiO 2 accelerates the phosphating process. - Abstract: This paper reports the development of nano SiO 2 incorporated nano zinc phosphate coatings on mild steel at low temperature for achieving better corrosion protection. A new formulation of phosphating bath at low temperature with nano SiO 2 was attempted to explore the possibilities of development of nano zinc phosphate coatings on mild steel with improved corrosion resistance. The coatings developed were studied by Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDX), X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and Electrochemical measurements. Significant variation in the coating weight, morphology and corrosion resistance was observed as nano SiO 2 concentrations varied from 0.5–4 g/L. The results showed that, the nano SiO 2 in the phosphating solution changed the initial potential of the interface between mild steel substrate and phosphating solution and reduce the activation energy of the phosphating process, increase the nucleation sites and yielded zinc phosphate coatings of higher coating weight, greater surface coverage and enhanced corrosion resistance. Better corrosion resistance was observed for coatings derived from phosphating bath containing 1.5 g/L nano SiO 2 . The new formulation reported in the present study was free from Ni or Mn salts and had very low concentration of sodium nitrite (0.4 g/L) as accelerator

  1. EBSD and EDS of nickel sulfide inclusions in glass

    International Nuclear Information System (INIS)

    Miflin, G.E.; Barry, J.C.

    2002-01-01

    Full text: A delayed phase transformation in small nickel sulfide inclusions can cause spontaneous fracture in toughened glass. Typically, a phase transformation within a 5 ?g nickel sulphide inclusion may break a window which weighs more than 50 kg. In most cases the nickel sulfide inclusions are detected only after window failure, although it is possible to detect the inclusions within intact glass. It is known that only type three nickel sulphide inclusions, that is, inclusions with a composition in the range Ni 7 S 6 to NiS 1.03 , break the glass. The solid-state phase transformation of alpha Ni 1-x S to beta NiS which induces a 2.5% volume increase has been given as the main reason for the spontaneous fracture. The aim of this present study is to investigate the crystal structure of phases within the type three inclusions using scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD). With EBSD it is possible to map regions of alpha Ni 1-x S and to distinguish those regions from regions with beta Ni 1-x S when the elemental compositions of the two regions are identical. The inclusions of this study came from two sources. One set of inclusions were found at initiation-of-fracture in glass windows that had failed by spontaneous fracture, while the other set were found in intact windows. All of the inclusions came from windows on buildings in the Brisbane area. The EBSD analysis was done at 20kV with the stage tilted to 70 degrees on a Philips XL30 SEM with LaB 6 filament, and with attached Oxford/Link Opal camera and software. EBSD mapping was done for alpha nickel sulfide (Ni 1-x S), beta nickel sulphide (NiS), heazelwoodite (Ni 3 S 2 ), and godlevskite (Ni 9 S 8 ). The integration time was 1.3 seconds for each point. Colour coded crystal phase and grain orientation maps were produced. EDS analysis was also done on the Philips XL30 with attached EDAX EDS detector. We found that although the EBSD technique is successful in identifying alpha

  2. Structural features of silver-doped phosphate glasses in zone of femtosecond laser-induced modification

    Science.gov (United States)

    Vasileva, A. A.; Nazarov, I. A.; Olshin, P. K.; Povolotskiy, A. V.; Sokolov, I. A.; Manshina, A. A.

    2015-10-01

    Femtosecond (fs) laser writing of two-dimensional microstructures (waveguides) is demonstrated in bulk phosphate glasses doped with silver ions. Silver-content phosphate and silver-content niobium-phosphate glasses with high concentration of silver oxide 55 mol% were used as samples for fs laser writing. The chemical network structure of the synthesized samples is analyzed through Raman spectroscopy and was found to be strongly sensitive to Nb incorporation. It was found that the direct laser writing process enables not only reorganization of glass network, but also formation of color centers and silver nanoparticles that are revealed in appearance of luminescence signal and plasmon absorption. The process of NPs' formation is more efficient for Nb-phosphate glass, while color centers are preferably formed in phosphate glass.

  3. Down-shifting by energy transfer in Tb{sup 3+}/Dy{sup 3+} co-doped zinc phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Caldiño, U., E-mail: cald@xanum.uam.mx [Departamento de Física, Universidad Autónoma Metropolitana-Iztapalapa, P.O. Box 55-534, México, D.F. 09340 (Mexico); Muñoz H, G.; Camarillo, I. [Departamento de Física, Universidad Autónoma Metropolitana-Iztapalapa, P.O. Box 55-534, México, D.F. 09340 (Mexico); Speghini, A. [Dipartimento di Biotecnologie, Università di Verona, and INSTM, UdR Verona, Strada Le Grazie 15, I-37314 Verona (Italy); IFAC CNR, Nello Carrara Institute of Applied Physics, MDF Lab, I-50019 Sesto Fiorentino, FI (Italy); Bettinelli, M. [Dipartimento di Biotecnologie, Università di Verona, and INSTM, UdR Verona, Strada Le Grazie 15, I-37314 Verona (Italy)

    2015-05-15

    An optical spectroscopy investigation of zinc phosphate glasses activated with Tb{sup 3+}/Dy{sup 3+} ions is carried out through photoluminescence spectra and decay time measurements. The emission color can be adjusted from yellow–green light, with CIE1931 chromaticity coordinates (0.36,0.44), toward the white light region (0.35,0.39) by decreasing the Tb{sup 3+} content from 1.0 to 0.1 mol% of Tb(PO{sub 3}){sub 3} upon Dy{sup 3+} excitation at 423 nm. Such visible region luminescence is generated by {sup 5}D{sub 4}→{sup 7}F{sub 5} and {sup 5}D{sub 4}→{sup 7}F{sub 3} emissions of Tb{sup 3+} in addition to {sup 4}I{sub 15/2}→{sup 6}H{sub 15/2}, {sup 4}F{sub 9/2}→{sup 6}H{sub 15/2}, {sup 4}F{sub 9/2}→{sup 6}H{sub 13/2} and {sup 4}F{sub 9/2}→{sup 6}H{sub 11/2} emissions of Dy{sup 3+}, so that Tb{sup 3+} emission is sensitized by Dy{sup 3+} through a non-radiative resonant energy transfer. A dominant {sup 5}D{sub 4}→{sup 7}F{sub 5} green emission is observed in detriment of the {sup 5}D{sub 3}→{sup 7}F{sub J} blue emissions upon 282 nm excitation, as well as an extended excitation range (280–500 nm), due to multiple Dy{sup 3+} and Tb{sup 3+} transitions, which might contribute to enhance the spectral response of solar photovoltaic cells by down-shifting of the incident solar spectrum. - Highlights: • Zn(PO{sub 3}){sub 2} glasses are optically activated with Tb{sup 3+}/Dy{sup 3+} (ZPTbDy). • Non-radiative resonant energy transfer takes place between Tb{sup 3+} and Dy{sup 3+}. • Luminescence can be adjusted from yellow–green light toward the white light region. • ZPTbDy phosphor exhibits spectroscopic properties for photovoltaic applications.

  4. Lead iron phosphate glass as a containment medium for disposal of high-level nuclear waste

    International Nuclear Information System (INIS)

    Boatner, L.A.; Sales, B.C.

    1989-01-01

    This patent describes lead-iron phosphate glasses containing a high level of Fe 2 O 3 for use as a storage medium for high-level radioactive nuclear waste. By combining lead-iron phosphate glass with various types of simulated high-level nuclear waste, a highly corrosion resistant, homogeneous, easily processed glass can be formed. For corroding solutions at 90 0 C, with solution pH values in the range between 5 and 9, the corrosion rate of the lead-iron phosphate nuclear waste glass is at least 10 2 to 10 3 times lower than the corrosion rate of a comparable borosilicate nuclear waste glass. The presence of Fe 2 O 3 in forming the lead-iron phosphate glass is critical. The lead-iron phosphate waste glasses can be prepared with minimal modification of the technology developed for processing borosilicate glass nuclear wasteforms

  5. Third-order nonlinearity of Er3+-doped lead phosphate glass

    Energy Technology Data Exchange (ETDEWEB)

    Santos, C. C. [Universidade Federal do Ceara, Ceara, Brazil; Guedes Da Silva, Ilde [ORNL; Siqueira, J. P. [Instituto de Física de São Carlos, Universidade de São Paulo, Brazil; Misoguti, L. [Instituto de Física de São Carlos, Universidade de São Paulo, Brazil; Zilio, S. C. [Instituto de Física de São Carlos, Universidade de São Paulo, Brazil; Boatner, Lynn A [ORNL

    2010-01-01

    The third-order optical susceptibility and dispersion of the linear refractive index of Er3+-doped lead phosphate glass were measured in the wavelength range between 400 and 1940 nm by using the spectrally resolved femtosecond Maker fringes technique. The nonlinear refractive index obtained from the third-order susceptibility was found to be five times higher than that of silica, indicating that Er3+-doped lead phosphate glass is a potential candidate to be used as the base component for the fabrication of photonic devices. For comparison purposes, the Z-scan technique was also employed to obtain the values of the nonlinear refractive index of E-doped lead phosphate glass at several wavelengths, and the values obtained using the two techniques agree to within 15%.

  6. 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.

  7. Research, development and demonstration of nickel-zinc batteries for electric vehicle propulsion

    Science.gov (United States)

    1980-06-01

    The feasibility of the nickel zinc battery for electric vehicle propulsion is discussed. The program is divided into seven distinct but highly interactive tasks collectively aimed at the development and commercialization of nickel zinc technology. These basic technical tasks are separator development, electrode development, product design and analysis, cell/module battery testing, process development, pilot manufacturing, and thermal manufacturing, and thermal management. Significant progress has been made in the understanding of separator failure mechanisms, and a generic category of materials has been specified for the 300+ deep discharge applications. Shape change has been reduced significantly. Progress in the area of thermal management was significant, with the development of a model that accurately represents heat generation and rejection rates during battery operation.

  8. Effect of Zinc Phosphate on the Corrosion Behavior of Waterborne Acrylic Coating/Metal Interface.

    Science.gov (United States)

    Wan, Hongxia; Song, Dongdong; Li, Xiaogang; Zhang, Dawei; Gao, Jin; Du, Cuiwei

    2017-06-14

    Waterborne coating has recently been paid much attention. However, it cannot be used widely due to its performance limitations. Under the specified conditions of the selected resin, selecting the function pigment is key to improving the anticorrosive properties of the coating. Zinc phosphate is an environmentally protective and efficient anticorrosion pigment. In this work, zinc phosphate was used in modifying waterborne acrylic coatings. Moreover, the disbonding resistance of the coating was studied. Results showed that adding zinc phosphate can effectively inhibit the anode process of metal corrosion and enhance the wet adhesion of the coating, and consequently prevent the horizontal diffusion of the corrosive medium into the coating/metal interface and slow down the disbonding of the coating.

  9. Structure and properties of gadolinium loaded calcium phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Cuiling [Analytical and Testing Center, Southwest University of Science and Technology, Mianyang 621010 (China); State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, Southwest University of Science and Technology, Mianyang 621010 (China); Liang, Xiaofeng, E-mail: XFLiang@swust.edu.cn [Analytical and Testing Center, Southwest University of Science and Technology, Mianyang 621010 (China); State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, Southwest University of Science and Technology, Mianyang 621010 (China); Li, Haijian; Yu, Huijun; Li, Zhen [Analytical and Testing Center, Southwest University of Science and Technology, Mianyang 621010 (China); State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, Southwest University of Science and Technology, Mianyang 621010 (China); Yang, Shiyuan [State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, Southwest University of Science and Technology, Mianyang 621010 (China)

    2014-10-15

    The glass samples with composition xGd{sub 2}O{sub 3}–(50 − x)CaO–50P{sub 2}O{sub 5} (0 ⩽ x ⩽ 9 mol%) were prepared by the conventional melt quench method. The structure and properties of gadolinium loaded in calcium phosphate glasses were investigated using XRD, SEM, DTA, IR and Raman spectroscopy. The XRD and SEM analysis for the samples show that the majority of samples are amorphous, and crystallization occurs when the content of Gd{sub 2}O{sub 3} containing is up to 6 mol%. Two main crystalline phases, Ca{sub 2}P{sub 2}O{sub 7} and Gd{sub 3}(P{sub 2}O{sub 7}){sub 3}, are embedded in an amorphous matrix. IR and Raman data indicate that glass structure consists of predominantly metaphosphate (Q{sup 2}) units and the depolymerization of phosphate network with the addition of Gd{sub 2}O{sub 3}. Both the chemical durability and the glass transition temperature (T{sub g}) are improved with the increase of Gd{sub 2}O{sub 3}, which suggests that the Gd acts a role of strengthening the cross-links between the phosphate chains of the glass.

  10. Immobilization of Uranium Silicide in Sintered Iron-Phosphate Glass

    International Nuclear Information System (INIS)

    Mateos, Patricia; Russo, Diego; Rodriguez, Diego; Heredia, A; Sanfilippo, M.; Sterba, Mario

    2003-01-01

    This work is a continuation of a previous one performed in vitrification of uranium silicide in borosilicate and iron-silicate glasses, by sintering.We present the results obtained with an iron-phosphate glass developed at our laboratory and we compare this results with those obtained with the above mentioned glasses. The main objective was to develop a method as simple as possible, so as to get a monolithic glass block with the appropriate properties to be disposed in a deep geological repository.The thermal transformation of the uranium silicide was characterized by DTA/TG analysis and X-ray diffraction.We determined the evolution of the crystalline phases and the change in weight.Calcined uranium silicide was mixed with natural U 3 O 8 , the amount of U 3 O 8 was calculated to simulate an isotopic dilution of 4%.This material was mixed with powdered iron-phosphate glass (in wt.%: 64,9 P 2 O 5 ; 22,7 Fe 2 O 3 ; 8,1 Al 2 O 3 ; 4,3 Na 2 O) in different proportions (in wt%): 7%, 10% y 15%.The powders were pressed and sintered at temperatures between 585 y 670 °C. Samples of the sintered pellet were prepared for the lixiviation tests (MCC-1P: monolithic samples; deionised water; 90° C; 7, 14 and 28 days).The samples showed a quite good durability (0,6 g.m -2 .day -1 ), similar to borosilicate glasses.The microstructure of the glass samples showed that the uranium particles are much better integrated to the glass matrix in the iron-phosphate glasses than in the borosilicate or iron-silicate glasses.We can conclude that the sintered product obtained could be a good alternative for the immobilization of nuclear wastes with high content of uranium, as the ones arising from the conditioning of research reactors spent fuels

  11. Structure and Degradation Behaviour of Calcium Phosphate Glasses

    International Nuclear Information System (INIS)

    Silva, A M B; Correia, R N; Fernandes, M H V; Oliveira, J M M

    2011-01-01

    Some studies have shown a relationship between glass structure and in vitro mineralization, generally associated with the rate of glass degradation, nature of released ions and subsequent Ca-P precipitation on glass surfaces when immersed in a Simulated Body Fluid (SBF). The knowledge of the ionic species distribution in glasses and of the involved bond strengths can be used to assess the in vitro behaviour of a glass. The role of ions such as silicon or titanium is of major importance for the development of new compositions and also for the control of glass degradation behaviour. A comparative study with two calcium phosphate glasses series was performed: Both glasses series - one with Si and another with Ti - include P 2 O 5 and alkaline earth ions in their compositions. Surface reactivity of glasses from the SiO 2 -containing system have been studied in SBF showing the precipitation of a Ca-P surface layer that increases with increasing MgO/CaO ratio. In glasses from the TiO 2 -containing series it is shown that the increase of TiO 2 contributes for the stabilization of the glass network thus allowing the control of their degradation rate when immersed in SBF. The relationship between structural features of these calcium-phosphate glasses and their degradation behaviour in SBF is discussed in terms of the structural role of Si and Ti ions. It is concluded that glasses with less interconnected species favour the Ca-P surface precipitation. The understanding of this relationship in synthetic physiological fluids is expected to allow the tailoring of glass degradation rates in complex biological systems.

  12. short communication binding of nickel and zinc ions with activated

    African Journals Online (AJOL)

    a

    Equilibrium sorption of nickel and zinc ions by the activated carbon was studied using a range of ... their toxicity, accumulative behaviour and effects on human health, heavy metal pollution has become ... The determination of the total surface charge was made .... These values suggest high efficiency of the activated carbon,.

  13. Characterization of Fe 3 + -doped silver phosphate glasses

    Indian Academy of Sciences (India)

    The relationship among the composition, structure and selected properties for five series of silver phosphate glasses containing 0, 5, 10, 15 and 20wt% Fe 2 O 3 has been investigated. The synthesized glasses have been characterized using different experimental techniques. X-ray diffraction studies revealed that the ...

  14. Observation of spin-glass behavior in nickel adsorbed few layer graphene

    International Nuclear Information System (INIS)

    Mitra, Sreemanta; Mondal, Oindrila; Banerjee, Sourish; Chakravorty, Dipankar

    2013-01-01

    Nickel-adsorbed graphene was prepared by first synthesizing graphite oxide (GO) by modified Hummers' method and then reducing a solution containing both GO and Ni 2+ . Energy dispersive X-ray spectroscopy analysis showed 31 at. % nickel was present. Magnetization measurements under both dc and ac magnetic fields were carried out in the temperature range 2 K to 300 K. The zero field cooled and field cooled magnetization data showed a pronounced irreversibility at a temperature around 20 K. The analysis of the ac susceptibility data was carried out by both Vogel-Fulcher as well as power law. From dynamic scaling analysis, the microscopic flipping time τ 0 ∼10 −13 s and critical exponent zν=5.9±0.1 were found, indicating the presence of conventional spin glass in the system. The spin glass transition temperature was estimated as 19.5 K. Decay of thermoremanent magnetization was explained by stretched exponential function with a value of the exponent as 0.6. From the results, it is concluded that nickel adsorbed graphene behaves like a spin-glass.

  15. Observation of spin-glass behavior in nickel adsorbed few layer graphene

    Energy Technology Data Exchange (ETDEWEB)

    Mitra, Sreemanta [MLS Professor of Physics' Unit, Indian Association for the Cultivation of Science, Kolkata-700032 (India); Department of Physics, University of Calcutta, Kolkata-700009 (India); Mondal, Oindrila [Department of Physics, M.U.C. Woman' s College, Burdwan (India); Banerjee, Sourish [Department of Physics, University of Calcutta, Kolkata-700009 (India); Chakravorty, Dipankar [MLS Professor of Physics' Unit, Indian Association for the Cultivation of Science, Kolkata-700032 (India)

    2013-01-14

    Nickel-adsorbed graphene was prepared by first synthesizing graphite oxide (GO) by modified Hummers' method and then reducing a solution containing both GO and Ni{sup 2+}. Energy dispersive X-ray spectroscopy analysis showed 31 at. % nickel was present. Magnetization measurements under both dc and ac magnetic fields were carried out in the temperature range 2 K to 300 K. The zero field cooled and field cooled magnetization data showed a pronounced irreversibility at a temperature around 20 K. The analysis of the ac susceptibility data was carried out by both Vogel-Fulcher as well as power law. From dynamic scaling analysis, the microscopic flipping time {tau}{sub 0}{approx}10{sup -13}s and critical exponent z{nu}=5.9{+-}0.1 were found, indicating the presence of conventional spin glass in the system. The spin glass transition temperature was estimated as 19.5 K. Decay of thermoremanent magnetization was explained by stretched exponential function with a value of the exponent as 0.6. From the results, it is concluded that nickel adsorbed graphene behaves like a spin-glass.

  16. Material and Energy Flows Associated with Select Metals in GREET 2. Molybdenum, Platinum, Zinc, Nickel, Silicon

    Energy Technology Data Exchange (ETDEWEB)

    Benavides, Pahola T. [Argonne National Lab. (ANL), Argonne, IL (United States); Dai, Qiang [Argonne National Lab. (ANL), Argonne, IL (United States); Sullivan, John L. [Argonne National Lab. (ANL), Argonne, IL (United States); Kelly, Jarod C. [Argonne National Lab. (ANL), Argonne, IL (United States); Dunn, Jennifer B. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-09-01

    In this work, we analyzed the material and energy consumption from mining to production of molybdenum, platinum, zinc, and nickel. We also analyzed the production of solar- and semiconductor-grade silicon. We described new additions to and expansions of the data in GREET 2. In some cases, we used operating permits and sustainability reports to estimate the material and energy flows for molybdenum, platinum, and nickel, while for zinc and silicon we relied on information provided in the literature.

  17. Laser properties of an improved average-power Nd-doped phosphate glass

    International Nuclear Information System (INIS)

    Payne, S.A.; Marshall, C.D.; Bayramian, A.J.

    1995-01-01

    The Nd-doped phosphate laser glass described herein can withstand 2.3 times greater thermal loading without fracture, compared to APG-1 (commercially-available average-power glass from Schott Glass Technologies). The enhanced thermal loading capability is established on the basis of the intrinsic thermomechanical properties (expansion, conduction, fracture toughness, and Young's modulus), and by direct thermally-induced fracture experiments using Ar-ion laser heating of the samples. This Nd-doped phosphate glass (referred to as APG-t) is found to be characterized by a 29% lower gain cross section and a 25% longer low-concentration emission lifetime

  18. Mechanical Coating of Zinc Particles with Bi2O3-Li2O-ZnO Glasses as Anode Material for Rechargeable Zinc-Based Batteries

    Directory of Open Access Journals (Sweden)

    Tobias Michlik

    2018-02-01

    Full Text Available The electrochemical performance of zinc particles with 250 μm and 30 μm diameters, coated with Bi2O3-Li2O-ZnO glass is investigated and compared with noncoated zinc particles. Galvanostatic investigations were conducted in the form of complete discharge and charging cycles in electrolyte excess. Coated 30 μm zinc particles provide the best rechargeability after complete discharge. The coatings reached an average charge capacity over 20 cycles of 113 mAh/g compared to the known zero rechargeability of uncoated zinc particles. Proposed reasons for the prolonged cycle life are effective immobilization of discharge products in the glass layer and the formation of percolating metallic bismuth and zinc phases, forming a conductive network through the glass matrix. The coating itself is carried out by mechanical ball milling. Different coating parameters and the resulting coating quality as well as their influence on the passivation and on the rechargeability of zinc–glass composites is investigated. Optimized coating qualities with respect to adhesion, homogeneity and compactness of the glass layer are achieved at defined preparation conditions, providing a glass coating content of almost 5 wt % for 250 μm zinc particles and almost 11 wt % for 30 μm zinc particles.

  19. Factors that Affect the Content of Cadmium, Nickel, Copper and Zinc in Tissues of the Knee Joint.

    Science.gov (United States)

    Roczniak, Wojciech; Brodziak-Dopierała, Barbara; Cipora, Elżbieta; Jakóbik-Kolon, Agata; Kluczka, Joanna; Babuśka-Roczniak, Magdalena

    2017-08-01

    Osteoarthritis causes the degradation of the articular cartilage and periarticular bones. Trace elements influence the growth, development and condition of the bone tissue. Changes to the mineral composition of the bone tissue can cause degenerative changes and fractures. The aim of the research was to determine the content of cadmium (Cd), nickel (Ni), copper (Cu) and zinc (Zn) in the tibia, the femur and the meniscus in men and women who underwent a knee replacement surgery. Samples were collected from 50 patients, including 36 women and 14 men. The determination of trace elements content were performed by ICP-AES method, using Varian 710-ES. Average concentration in the tissues of the knee joint teeth amounted for cadmium 0.015, nickel 0.60, copper 0.89 and zinc 80.81 mg/kg wet weight. There were statistically significant differences in the content of cadmium, copper and zinc in different parts of the knee joint. There were no statistically significant differences in the content of cadmium, nickel, copper and zinc in women and men in the examined parts of the knee joint. Among the elements tested, copper and nickel showed a high content in the connective tissue (the meniscus) compared to the bone tissue (the tibia and the femur).

  20. Nanoparticles of nickel oxide: growth and organization on zinc-substituted anionic clay matrix by one-pot route at room temperature

    International Nuclear Information System (INIS)

    Carja, Gabriela; Nakajima, Akira; Dranca, Cristian; Okada, Kiyoshi

    2010-01-01

    A room temperature nanocarving strategy is developed for the fabrication of nanoparticles of nickel oxide on zinc-substituted anionic clay matrix (Ni/ZnLDH). It is based on the growth and organization of nanoparticles of nickel oxide which occur during the structural reconstruction of the layered structure of the anionic clay in NiSO 4 aqueous solution. No organic compounds are used during the fabrication. The described material was characterized by X-ray diffraction (XRD), IR spectroscopy (FTIR), transmission electron microscopy (TEM), field-emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) spectroscopy, and X-ray photoelectron spectroscopy (XPS). Results show that the nickel-clay nanoarchitecture consists of small nanoparticles of nickel oxide (average size 7 nm) deposited on the larger nanoparticles (average size 90 nm) of zinc-substituted clay. The optical properties of the new nickel-zinc formulation are studied by UV-Vis.

  1. Nanoparticles of nickel oxide: growth and organization on zinc-substituted anionic clay matrix by one-pot route at room temperature

    Science.gov (United States)

    Carja, Gabriela; Nakajima, Akira; Dranca, Cristian; Okada, Kiyoshi

    2010-10-01

    A room temperature nanocarving strategy is developed for the fabrication of nanoparticles of nickel oxide on zinc-substituted anionic clay matrix (Ni/ZnLDH). It is based on the growth and organization of nanoparticles of nickel oxide which occur during the structural reconstruction of the layered structure of the anionic clay in NiSO4 aqueous solution. No organic compounds are used during the fabrication. The described material was characterized by X-ray diffraction (XRD), IR spectroscopy (FTIR), transmission electron microscopy (TEM), field-emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) spectroscopy, and X-ray photoelectron spectroscopy (XPS). Results show that the nickel-clay nanoarchitecture consists of small nanoparticles of nickel oxide (average size 7 nm) deposited on the larger nanoparticles (average size 90 nm) of zinc-substituted clay. The optical properties of the new nickel-zinc formulation are studied by UV-Vis.

  2. Novel selenium containing boro-phosphate glasses: preparation and structural study.

    Science.gov (United States)

    Ciceo-Lucacel, R; Radu, T; Ponta, O; Simon, V

    2014-06-01

    We synthesized a new boro-phosphate glass system with different %mol SeO2 content by conventional melt quenching technique. All samples were obtained in a glassy state with the vitreous structure confirmed by X-ray diffraction analysis. Scanning electron microscopy (SEM) revealed some non-homogeneous domains on the glasses surface, and their tendency to link each other once the selenium oxide content increases. Energy-dispersive X-ray analysis (EDAX) indicated similar elemental composition in different regions of each sample. X-ray photoelectron spectroscopy (XPS) was used to determine the nature of chemical bonding and the elemental composition at the sample surfaces, and Fourier transform infrared (FT-IR) spectroscopy was used to determine the structural groups in the obtained glass structure. Based on FT-IR results, the glass structure at short range order consists mainly of small phosphate units such as pyrophosphate (i.e. P2O7(4-) dimmers or terminating groups at the end of phosphate chains) and some metaphosphate (i.e. PO3(-) middle groups in the phosphate chains) units. The boron atoms are mainly placed in three-coordinated sites in BØ3 or BØ2O(-) units. A small contribution of BØ4(-) units was also detected from the FT-IR spectra of glasses. For SeO2 content higher than 5mol%, the modifier role of selenium ions is strongly reflected on the local structure dominated in this case by pyrophosphate units. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Lead iron phosphate glass as a containment medium for disposal of high-level nuclear waste

    Science.gov (United States)

    Boatner, Lynn A.; Sales, Brian C.

    1989-01-01

    Lead-iron phosphate glasses containing a high level of Fe.sub.2 O.sub.3 for use as a storage medium for high-level radioactive nuclear waste. By combining lead-iron phosphate glass with various types of simulated high-level nuclear waste, a highly corrosion resistant, homogeneous, easily processed glass can be formed. For corroding solutions at 90.degree. C., with solution pH values in the range between 5 and 9, the corrosion rate of the lead-iron phosphate nuclear waste glass is at least 10.sup.2 to 10.sup.3 times lower than the corrosion rate of a comparable borosilicate nuclear waste glass. The presence of Fe.sub.2 O.sub.3 in forming the lead-iron phosphate glass is critical. Lead-iron phosphate nuclear waste glass can be prepared at temperatures as low as 800.degree. C., since they exhibit very low melt viscosities in the 800.degree. to 1050.degree. C. temperature range. These waste-loaded glasses do not readily devitrify at temperatures as high as 550.degree. C. and are not adversely affected by large doses of gamma radiation in H.sub.2 O at 135.degree. C. The lead-iron phosphate waste glasses can be prepared with minimal modification of the technology developed for processing borosilicate glass nuclear wasteforms.

  4. Investigation of alumino-phosphate glasses for iodine conditioning

    International Nuclear Information System (INIS)

    Lemesle, T.

    2013-01-01

    Iodine 129 is a long-lived intermediate level radioactive waste, which is currently managed by isotopic dilution. In view of an alternative management by geological disposal, we aimed at developing phosphate glasses of the AgI-Ag 2 O-P 2 O 5 -Al 2 O 3 system, elaborated at low temperature and without iodine volatilization. Alumina is expected to induce crosslinking of the phosphate network and thus to improve the thermal and chemical properties. To define a glass composition that meets the specifications, we varied the level of iodine, the Ag 2 O/P 2 O 5 ratio and alumina content. For 1 g.cm -3 of iodine, SEM-EDS observations indicate that alumina solubility is limited to 0.5% mol., independently of Ag 2 O/P 2 O 5 ratio. The structural study by 31 P, 27 Al and 109 Ag MAS NMR, shows that aluminum adopts an octahedral coordination that effectively contributes to the crosslinking of the glassy network and iodine is incorporated without clustering. 31 P- 27 Al NMR correlations confirmed the presence of an alumino-phosphate network, and 31 P- 31 P correlations indicate that iodine does not change the connectivity of the glass network. The glass composition 28,8AgI-44,2Ag 2 O-26,5P 2 O 5 -0,5Al 2 O 3 presents the best compromise between the level of incorporation of iodine and the chemical durability, has a glass transition temperature of 123 C and an initial alteration rate in pure water at 50 C of 6 g.m -2 .d -1 . The long-term behavior of this glass is controlled by a post-alteration structure based on pyrophosphate, which holds nearly 80% of the initial iodine. (author) [fr

  5. Electrochemical and spectroscopic in situ techniques for the investigation of the phosphating of zinc coated steel

    International Nuclear Information System (INIS)

    Tomandl, A.

    2003-05-01

    In this work spectroscopic and electrochemical techniques were developed for the investigation of surface treatments used in steel industry. ICP-atomic emission spectroscopy (ICP-AES), Raman spectroscopy and the Quartz crystal microbalance (QCM) were applied to the investigation of the kinetics of phosphating as well as the properties of phosphate layers. Phosphating of zinc coated steel leads to the formation of a crystalline layer consisting of zinc phosphate and is employed to enhance paint adhesion and corrosion protection. For the high reaction rates necessary in industrial production lines, oxidation agents are added to the phosphating bathes to accelerate the reaction. The oxidation agents provide an additional reduction reaction beside the hydrogen formation and therefore decrease the number of gas bubbles, which would block the zinc surface and reduce the rate of phosphating. With addition of H2O2 or nitrates the rate of layer formation is distinctly increased. In a combined experiment of ICP-AES with QCM and potential transients, it was shown that the presence of these accelerators in the phosphating bath increases the rate of zinc dissolution and hence leads to a faster formation of the phosphate layer. In under paint corrosion of painted, zinc coated steel phosphate layers are exposed to a highly alkaline environment. The stability of a phosphate layer against alkaline attack is therefore essential for its performance in corrosion protection. To enhance the alkaline stability Mn and Ni are added to modern phosphating bathes. The incorporation of these elements reduces the dissolution rate in 0.1 M NaOH proportional to their concentration in the phosphate layer. The dissolution of Zn, P, Mn and Ni was determined quantitatively with ICP-AES. Raman spectroscopy showed the formation of a Mn-hydroxide layer during alkaline attack, which protects the phosphate layer and reduces further dissolution. On basis of these results the reaction of phosphate layers

  6. Preparation method and thermal properties of samarium and europium-doped alumino-phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Sava, B.A., E-mail: savabogdanalexandru@yahoo.com [National Institute of Research and Development for Optoelectronics, Department for Optospintronics, 409 Atomistilor Street, P.O. Box MG – 5, RO-77125 Magurele (Romania); Elisa, M., E-mail: astatin18@yahoo.com [National Institute of Research and Development for Optoelectronics, Department for Optospintronics, 409 Atomistilor Street, P.O. Box MG – 5, RO-77125 Magurele (Romania); Boroica, L., E-mail: boroica_lucica@yahoo.com [National Institute for Lasers, Plasma and Radiation Physics, 77125 Magurele (Romania); Monteiro, R.C.C., E-mail: rcm@fct.unl.pt [Center of Materials Research/Institute for Nanostructures, Nanomodelling and Nanofabrication, (CENIMAT/I3N), Department of Materials Sciences, Faculty of Sciences and Technology, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal)

    2013-12-01

    Highlights: • Improved preparation method of rare-earth-doped phosphate glasses was done. • Working and annealing temperatures were lower than for undoped phosphate glass. • Doped glass viscosity is also lower and has quasi-linear variation with temperature. • Exothermic peak appears at about 555 °C and 685 °C, due to devitrification in glass. -- Abstract: The present work investigates alumino-phosphate glasses from Li{sub 2}O–BaO–Al{sub 2}O{sub 3}–La{sub 2}O{sub 3}–P{sub 2}O{sub 5} system containing Sm{sup 3+} and Eu{sup 3+} ions, prepared by two different ways: a wet raw materials mixing route followed by evaporation and melt-quenching, and by remelting of shards. The linear thermal expansion coefficient measured by dilatometry is identical for both rare-earth-doped phosphate glasses. Comparatively to undoped phosphate glass the linear thermal expansion coefficient increases with 2 × 10{sup −7} K{sup −1} when dopants are added. The characteristic temperatures very slowly decrease but can be considered constant with atomic weight, atomic number and f electrons number of the doping ions in the case of T{sub g} (vitreous transition temperature) and T{sub sr} (high annealing temperature) but slowly increase in the case of T{sub ir} (low annealing temperature–strain point) and very slowly increase, being practically constant in the case of T{sub D} (dilatometric softening temperature). Comparatively to undoped phosphate glass the characteristic temperatures of Sm and Eu-doped glasses present lower values. The higher values of electrical conductance for both doped glasses, comparatively to usual soda-lime-silicate glass, indicate a slightly reduced stability against water. The viscosity measurements, showed a quasi-linear variation with temperature the mean square deviation (R{sup 2}) being ranged between 0.872% and 0.996%. The viscosity of doped glasses comparatively to the undoped one is lower at the same temperature. Thermogravimetric

  7. Effects of titanium nanoparticles on self-cleaning and structural features of zinc-magnesium-phosphate glass

    International Nuclear Information System (INIS)

    Ismail, S.F.; Sahar, M.R.; Ghoshal, S.K.

    2016-01-01

    Graphical abstract: Water contact angle for sample S2, S3, S4 and S5. The water contact angle increased with increased the titanium NPs content (mol%). - Highlights: • ZnO–MgO–P_2O_5 embedded TiO_2 NPs prepared by conventional melt-quenching method. • The amorphous nature is confirmed by X-ray diffraction spectroscopy. • The structural characteristics of glasses is investigated using FTIR and Raman. • Wettability of the glasses surface by water contact angle. - Abstract: The loss of glass transparency on surface pollutants contamination unless inhibited not only causes vision obscurity but also responsible for major aesthetic damages of cultural heritage. It is due to the sticking of fine dirt particles on wetting layers, a complex process with several possible ramifications still to be clarified. We report the influence of titanium dioxide or titania (TiO_2) nanoparticles (NPs) on the structural and self-cleaning properties of zinc–magnesium–phosphate glasses. Following melt-quenching method glass samples of optimized composition (42 − x)P_2O_5–8MgO–50ZnO–xTiO_2 with x = 0, 1, 2, 3 and 4 mol% are prepared. XRD patterns verified their amorphous nature and TEM images revealed the nucleation of TiO_2 NPs of average diameter ≈4.05 ± 0.01 nm. Fourier transform infrared (FTIR) spectra displayed four absorption band centred at 1618–3438 cm"−"1, 902– 931 cm"−"1, 757–762 cm"−"1 and 531–560 cm"−"1. Raman spectra exhibited four peaks each accompanied by a blue-shift. Water contact angle is found to increase with the increase of titanium NPs concentration into the amorphous matrix. This knowledge can be used to set up strategies and selective treatments to preventing glass transparency loss via the modification of self-cleaning attributes.

  8. Effects of titanium nanoparticles on self-cleaning and structural features of zinc-magnesium-phosphate glass

    Energy Technology Data Exchange (ETDEWEB)

    Ismail, S.F.; Sahar, M.R., E-mail: mrahim057@gmail.com; Ghoshal, S.K.

    2016-02-15

    Graphical abstract: Water contact angle for sample S2, S3, S4 and S5. The water contact angle increased with increased the titanium NPs content (mol%). - Highlights: • ZnO–MgO–P{sub 2}O{sub 5} embedded TiO{sub 2} NPs prepared by conventional melt-quenching method. • The amorphous nature is confirmed by X-ray diffraction spectroscopy. • The structural characteristics of glasses is investigated using FTIR and Raman. • Wettability of the glasses surface by water contact angle. - Abstract: The loss of glass transparency on surface pollutants contamination unless inhibited not only causes vision obscurity but also responsible for major aesthetic damages of cultural heritage. It is due to the sticking of fine dirt particles on wetting layers, a complex process with several possible ramifications still to be clarified. We report the influence of titanium dioxide or titania (TiO{sub 2}) nanoparticles (NPs) on the structural and self-cleaning properties of zinc–magnesium–phosphate glasses. Following melt-quenching method glass samples of optimized composition (42 − x)P{sub 2}O{sub 5}–8MgO–50ZnO–xTiO{sub 2} with x = 0, 1, 2, 3 and 4 mol% are prepared. XRD patterns verified their amorphous nature and TEM images revealed the nucleation of TiO{sub 2} NPs of average diameter ≈4.05 ± 0.01 nm. Fourier transform infrared (FTIR) spectra displayed four absorption band centred at 1618–3438 cm{sup −1}, 902– 931 cm{sup −1}, 757–762 cm{sup −1} and 531–560 cm{sup −1}. Raman spectra exhibited four peaks each accompanied by a blue-shift. Water contact angle is found to increase with the increase of titanium NPs concentration into the amorphous matrix. This knowledge can be used to set up strategies and selective treatments to preventing glass transparency loss via the modification of self-cleaning attributes.

  9. Modelling aqueous corrosion of nuclear waste phosphate glass

    Energy Technology Data Exchange (ETDEWEB)

    Poluektov, Pavel P.; Schmidt, Olga V.; Kascheev, Vladimir A. [Bochvar All-Russian Scientific Research Institute for Inorganic Materials (VNIINM), Moscow (Russian Federation); Ojovan, Michael I., E-mail: m.ojovan@sheffield.ac.uk [Immobilisation Science Laboratory, Department of Materials Science and Engineering, University of Sheffield, Mappin Street, Sheffield, S1 3JD (United Kingdom)

    2017-02-15

    A model is presented on nuclear sodium alumina phosphate (NAP) glass aqueous corrosion accounting for dissolution of radioactive glass and formation of corrosion products surface layer on the glass contacting ground water of a disposal environment. Modelling is used to process available experimental data demonstrating the generic inhibiting role of corrosion products on the NAP glass surface. - Highlights: • The radionuclides yield is determined by the transport from the glass through the surface corrosion layer. • Formation of the surface layer is due to the dissolution of the glass network and the formation of insoluble compounds. • The model proposed accounts for glass dissolution, formation of corrosion layer, specie diffusion and chemical reactions. • Analytical solutions are found for corrosion layer growth rate and glass components component leaching rates.

  10. Study of Cadmium adsorption of Nickel and Zinc on a natural bentonite and homo ionic of sodium

    International Nuclear Information System (INIS)

    Silva Giraldo, German Dario; Pinzon Bello, Jorge Alejo

    1999-01-01

    It was studied the adsorption of cadmium, nickel and zinc in aqueous solution at 25oC over a bentonite from the Cauca Valley, in its native state as well as in its sodium homo ionic form. The Langmuir isotherm adequately describes the adsorption of these metal ions over both bentonites, and the thermodynamic distribution coefficient, Kdm, which allow quantifying the degree of adsorption, can be calculated. Baeyens-bradbury model correlates well the adsorption of the metal ions over both bentonites but Kdm cannot be calculated from it. The adsorption data do not adjust to freundlich isotherm or B.E.T. As well as they do to the previously mentioned models. The sodium homo ionic bentonite adsorbs nickel and zinc better than the native bentonite, whereas there are not significant differences in cadmium adsorption. The order of adsorption over both bentonites, Cadmium > Zinc > Nickel, follow the HSAB principle

  11. Spectral-luminescence properties of trivalent titanium in aluminum-sodium phosphate glass

    International Nuclear Information System (INIS)

    Sukhanov, S.B.; Batyaev, I.M.

    1992-01-01

    Since development of the first crystal laser, Al 2 O 3 crystals remain the most widely used in quantum electronics. In the present work, the aluminum-sodium phosphate glass, Al 2 O 3 -Na 2 O 3 -P 2 O 5 , was studied with different proportions of components. A luminescence medium is obtained based on phosphate glass doped by Ti 3+ ions with intense emission in the 700-900-nm spectral range. This glass is a promising lasing medium for tunable solid-state lasers. 12 refs., 2 figs

  12. Lithium-Ion Mobility in Quaternary Boro-Germano-Phosphate Glasses.

    Science.gov (United States)

    Moguš-Milanković, Andrea; Sklepić, Kristina; Mošner, Petr; Koudelka, Ladislav; Kalenda, Petr

    2016-04-28

    Effect of the structural changes, electrical conductivity, and dielectric properties on the addition of a third glass-former, GeO2, to the borophosphate glasses, 40Li2O-10B2O3-(50 - x)P2O5-xGeO2, x = 0-25 mol %, has been studied. Introduction of GeO2 causes the structural modifications in the glass network, which results in a continuous increase in electrical conductivity. Glasses with low GeO2 content, up to 10 mol %, show a rapid increase in dc conductivity as a result of the interlinkage of slightly depolymerized phosphate chains and negatively charged [GeO4](-) units, which enhances the migration of Li(+) ions. The Li(+) ions compensate these delocalized charges connecting both phosphate and germanium units, which results in reduction of both bond effectiveness and binding energy of Li(+) ions and therefore enables their hop to the next charge-compensating site. For higher GeO2 content, the dc conductivity increases slightly, tending to approach a maximum in Li(+) ion mobility caused by the incorporation of GeO2 units into phosphate network combined with conversion of GeO4 to GeO6 units. The strong cross-linkage of germanium and phosphate units creates heteroatomic P-O-Ge bonds responsible for more effectively trapped Li(+) ions. A close correspondence between dielectric and conductivity parameters at high frequencies indicates that the increase in conductivity indeed is controlled by the modification of structure as a function of GeO2 addition.

  13. Some aspects of nanocrystalline nickel and zinc ferrites processed using microemulsion technique

    NARCIS (Netherlands)

    Misra, RDK; Kale, A; Kooi, BJ; De Hosson, JTM

    2003-01-01

    Nanocrystalline nickel and zinc ferrites synthesised using a microemulsion technique were characterised by high resolution transmission electron microscopy and vibrating sample magnetometry. A narrow and uniform distribution of crystals of size range 5-8 nm, distinguished by a clear lack of

  14. In Vitro Comparison of Zinc Phosphate and Glass Ionomers Ability to Inhibit Decalcification under and Adjacent to Orthodontic Bands.

    Science.gov (United States)

    1985-08-01

    confer the ability to leach fluoride ions into the surrounding tooth enamel . Kidd 3 7 using an artifical caries tec- hnique with a diffusion controlled...5 - Enamel Changes Scoring System- 1. NONE: No color change evident 2. MILD: Slight change in enamel color 3.MODERATE: Definate whitening of enamel ...to adhere to stainless steel and to tooth enamel with a chemical bond 51 . Zinc phosphate, on the other hand, does not chemically adhere to enamel or

  15. Structure of cesium loaded iron phosphate glasses: An infrared and Raman spectroscopy study

    International Nuclear Information System (INIS)

    Joseph, Kitheri; Premila, M.; Amarendra, G.; Govindan Kutty, K.V.; Sundar, C.S.; Vasudeva Rao, P.R.

    2012-01-01

    The structure of cesium loaded iron phosphate glasses (IPG) was investigated using infrared and Raman spectroscopy. The spectra of the cesium doped samples revealed a structural modification of the parent glass owing to the incorporation of cesium. The structural changes could be correlated with the variation observed in the glass transition temperature of these glasses. Increased Cs-mediated cationic cross linking appears to be the reason for the initial rise in glass transition temperature up to 21 mol% Cs 2 O in IPG; while, breakdown of the phosphate network with increasing cesium content, brings down the glass transition temperature.

  16. Novel selenium containing boro-phosphate glasses: Preparation and structural study

    Energy Technology Data Exchange (ETDEWEB)

    Ciceo-Lucacel, R.; Radu, T., E-mail: teodora.radu@phys.ubbcluj.ro; Ponta, O.; Simon, V.

    2014-06-01

    We synthesized a new boro-phosphate glass system with different %mol SeO{sub 2} content by conventional melt quenching technique. All samples were obtained in a glassy state with the vitreous structure confirmed by X-ray diffraction analysis. Scanning electron microscopy (SEM) revealed some non-homogeneous domains on the glasses surface, and their tendency to link each other once the selenium oxide content increases. Energy-dispersive X-ray analysis (EDAX) indicated similar elemental composition in different regions of each sample. X-ray photoelectron spectroscopy (XPS) was used to determine the nature of chemical bonding and the elemental composition at the sample surfaces, and Fourier transform infrared (FT-IR) spectroscopy was used to determine the structural groups in the obtained glass structure. Based on FT-IR results, the glass structure at short range order consists mainly of small phosphate units such as pyrophosphate (i.e. P{sub 2}O{sub 7}{sup 4−} dimmers or terminating groups at the end of phosphate chains) and some metaphosphate (i.e. PO{sub 3}{sup −} middle groups in the phosphate chains) units. The boron atoms are mainly placed in three-coordinated sites in BØ{sub 3} or BØ{sub 2}O{sup −} units. A small contribution of BØ{sub 4}{sup −} units was also detected from the FT-IR spectra of glasses. For SeO{sub 2} content higher than 5 mol%, the modifier role of selenium ions is strongly reflected on the local structure dominated in this case by pyrophosphate units. - Highlights: • New P{sub 2}O{sub 5}-CaO-B{sub 2}O{sub 3}-SeO{sub 2} glasses synthesized by conventional melt quenching method. • Evidences for the Se ions modifier role in the local structure by FT-IR and XPS. • Significant advances in understanding the structural properties of the new system.

  17. Novel selenium containing boro-phosphate glasses: Preparation and structural study

    International Nuclear Information System (INIS)

    Ciceo-Lucacel, R.; Radu, T.; Ponta, O.; Simon, V.

    2014-01-01

    We synthesized a new boro-phosphate glass system with different %mol SeO 2 content by conventional melt quenching technique. All samples were obtained in a glassy state with the vitreous structure confirmed by X-ray diffraction analysis. Scanning electron microscopy (SEM) revealed some non-homogeneous domains on the glasses surface, and their tendency to link each other once the selenium oxide content increases. Energy-dispersive X-ray analysis (EDAX) indicated similar elemental composition in different regions of each sample. X-ray photoelectron spectroscopy (XPS) was used to determine the nature of chemical bonding and the elemental composition at the sample surfaces, and Fourier transform infrared (FT-IR) spectroscopy was used to determine the structural groups in the obtained glass structure. Based on FT-IR results, the glass structure at short range order consists mainly of small phosphate units such as pyrophosphate (i.e. P 2 O 7 4− dimmers or terminating groups at the end of phosphate chains) and some metaphosphate (i.e. PO 3 − middle groups in the phosphate chains) units. The boron atoms are mainly placed in three-coordinated sites in BØ 3 or BØ 2 O − units. A small contribution of BØ 4 − units was also detected from the FT-IR spectra of glasses. For SeO 2 content higher than 5 mol%, the modifier role of selenium ions is strongly reflected on the local structure dominated in this case by pyrophosphate units. - Highlights: • New P 2 O 5 -CaO-B 2 O 3 -SeO 2 glasses synthesized by conventional melt quenching method. • Evidences for the Se ions modifier role in the local structure by FT-IR and XPS. • Significant advances in understanding the structural properties of the new system

  18. Properties and structure of high erbium doped phosphate glass for short optical fibers amplifiers

    International Nuclear Information System (INIS)

    Seneschal, Karine; Smektala, Frederic; Bureau, Bruno; Floch, Marie Le; Jiang Shibin; Luo, Tao; Lucas, Jacques; Peyghambarian, Nasser

    2005-01-01

    New phosphate glasses have been developed in order to incorporate high rare-earth ions concentrations. These glasses present a great chemical stability and a high optical quality. The phosphate glass network is open, very flexible, with a linkage of the tetrahedrons very disordered and contains a larger number of non-bridging oxygens (66%). The great stability and resistance against crystallization associated with the possibility to incorporate high doping concentration of rare-earth ions in these phosphate glasses make them very good candidates for the realization of ultra short single mode amplifiers with a high gain at 1.55 μm

  19. The therapeutic effect on bone mineral formation from biomimetic zinc containing tricalcium phosphate (ZnTCP in zinc-deficient osteoporotic mice.

    Directory of Open Access Journals (Sweden)

    Joshua Chou

    Full Text Available The aim of this study was to evaluate the therapeutic efficacy of biomimetic zinc-containing tricalcium phosphate (ZnTCP produced by hydrothermally converting calcium carbonate exoskeletons from foraminifera, in the treatment of osteoporotic mice. X-Ray powder diffraction showed crystallographic structures matching JCPDS profile for tricalcium phosphate. Mass spectroscopy used to calculate total composition amount showed similar amount of calcium (5×10(4 µg/g and phosphate (4×10(4 ppm after conversion and the presence of zinc (5.18×10(3 µg/g. In vitro zinc release showed no release in PBS buffer and <1% zinc release in 7 days. In vivo evaluation was done in ovariectomized mice by implanting the ZnTCP samples in the soft tissues near the right femur bone for four weeks. Thirty ddY mice (5 weeks old, average weight of 21 g were divided into six experimental groups (normal, sham, OVX, β-TCP, ZnTCP and direct injection of zinc. CT images were taken every two weeks where the bone mineral density (BMD and bone mineral content (BMC were calculated by software based on CT images. The ZnTCP group exhibits cortical and cancellous bone growth of 45% and 20% respectively. While sham, OVX and β-TCP suffered from bone loss. A correlation was made between the significant body weight increase in ZnTCP with the significant increase in plasma zinc level compared with OVX. The presented results indicate that biomimetic ZnTCP were effective in preventing and treating bone loss in osteoporotic mice model.

  20. Short-term in vivo evaluation of zinc-containing calcium phosphate using a normalized procedure

    Energy Technology Data Exchange (ETDEWEB)

    Calasans-Maia, Monica, E-mail: monicacalasansmaia@gmail.com [Dental Clinical Research Center, Dentistry School, Fluminense Federal University, Niteroi, Rio de Janeiro (Brazil); Calasans-Maia, José, E-mail: josecalasans@gmail.com [Dental Clinical Research Center, Dentistry School, Fluminense Federal University, Niteroi, Rio de Janeiro (Brazil); Santos, Silvia, E-mail: silviaquimica@gmail.com [LABIOMAT, Brazilian Center for Physics Research, CBPF, Rio de Janeiro (Brazil); Mavropoulos, Elena, E-mail: elena@cbpf.br [LABIOMAT, Brazilian Center for Physics Research, CBPF, Rio de Janeiro (Brazil); Farina, Marcos, E-mail: mfarina@anato.ufrj.br [Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro (Brazil); Lima, Inayá, E-mail: inayacorrea@gmail.com [Nuclear Instrumentation Laboratory, Nuclear Engineering Program, COPPE, Federal University of Rio de Janeiro, Rio de Janeiro (Brazil); Lopes, Ricardo Tadeu [Nuclear Instrumentation Laboratory, Nuclear Engineering Program, COPPE, Federal University of Rio de Janeiro, Rio de Janeiro (Brazil); Rossi, Alexandre, E-mail: rossi@cbpf.br [LABIOMAT, Brazilian Center for Physics Research, CBPF, Rio de Janeiro (Brazil); Granjeiro, José Mauro, E-mail: jmgranjeiro@gmail.com [Dental Clinical Research Center, Dentistry School, Fluminense Federal University, Niteroi, Rio de Janeiro (Brazil); Bioengineering Division, National Institute of Metrology, Quality and Technology, Duque de Caxias, Rio de Janeiro (Brazil)

    2014-08-01

    The effect of zinc-substituted calcium phosphate (CaP) on bone osteogenesis was evaluated using an in vivo normalized ISO 10993-6 protocol. Zinc-containing hydroxyapatite (ZnHA) powder with 0.3% by wt zinc (experimental group) and stoichiometric hydroxyapatite (control group) were shaped into cylindrical implants (2 × 6 mm) and were sintered at 1000 °C. Thermal treatment transformed the ZnHA cylinder into a biphasic implant that was composed of Zn-substituted HA and Zn-substituted β-tricalcium phosphate (ZnHA/βZnTCP); the hydroxyapatite cylinder was a highly crystalline and poorly soluble HA implant. In vivo tests were performed in New Zealand White rabbits by implanting two cylinders of ZnHA/βZnTCP in the left tibia and two cylinders of HA in the right tibia for 7, 14 and 28 days. Incorporation of 0.3% by wt zinc into CaP increased the rate of Zn release to the biological medium. Microfluorescence analyses (μXRF-SR) using synchrotron radiation suggested that some of the Zn released from the biomaterial was incorporated into new bone near the implanted region. In contrast with previous studies, histomorphometric analysis did not show significant differences between the newly formed bone around ZnHA/βZnTCP and HA due to the dissolution profile of Zn-doped CaP. Despite the great potential of Zn-containing CaP matrices for future use in bone regeneration, additional in vivo studies must be conducted to explain the mobility of zinc at the CaP surface and its interactions with a biological medium. - Highlights: • We produced a hydroxyapatite containing a low concentration (0.3 wt.%) of zinc. • The biomaterial underwent characterization before and after in vivo implant. • In vivo tests were performed according to ISO 10993-6. • Zinc-containing calcium phosphate promotes osteoconduction and bone regeneration. • Zinc-containing calcium phosphate may be useful for clinical applications.

  1. Short-term in vivo evaluation of zinc-containing calcium phosphate using a normalized procedure

    International Nuclear Information System (INIS)

    Calasans-Maia, Monica; Calasans-Maia, José; Santos, Silvia; Mavropoulos, Elena; Farina, Marcos; Lima, Inayá; Lopes, Ricardo Tadeu; Rossi, Alexandre; Granjeiro, José Mauro

    2014-01-01

    The effect of zinc-substituted calcium phosphate (CaP) on bone osteogenesis was evaluated using an in vivo normalized ISO 10993-6 protocol. Zinc-containing hydroxyapatite (ZnHA) powder with 0.3% by wt zinc (experimental group) and stoichiometric hydroxyapatite (control group) were shaped into cylindrical implants (2 × 6 mm) and were sintered at 1000 °C. Thermal treatment transformed the ZnHA cylinder into a biphasic implant that was composed of Zn-substituted HA and Zn-substituted β-tricalcium phosphate (ZnHA/βZnTCP); the hydroxyapatite cylinder was a highly crystalline and poorly soluble HA implant. In vivo tests were performed in New Zealand White rabbits by implanting two cylinders of ZnHA/βZnTCP in the left tibia and two cylinders of HA in the right tibia for 7, 14 and 28 days. Incorporation of 0.3% by wt zinc into CaP increased the rate of Zn release to the biological medium. Microfluorescence analyses (μXRF-SR) using synchrotron radiation suggested that some of the Zn released from the biomaterial was incorporated into new bone near the implanted region. In contrast with previous studies, histomorphometric analysis did not show significant differences between the newly formed bone around ZnHA/βZnTCP and HA due to the dissolution profile of Zn-doped CaP. Despite the great potential of Zn-containing CaP matrices for future use in bone regeneration, additional in vivo studies must be conducted to explain the mobility of zinc at the CaP surface and its interactions with a biological medium. - Highlights: • We produced a hydroxyapatite containing a low concentration (0.3 wt.%) of zinc. • The biomaterial underwent characterization before and after in vivo implant. • In vivo tests were performed according to ISO 10993-6. • Zinc-containing calcium phosphate promotes osteoconduction and bone regeneration. • Zinc-containing calcium phosphate may be useful for clinical applications

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

    International Nuclear Information System (INIS)

    Mandal, Ashis K.; Balaji, S.; Sen, Ranjan

    2014-01-01

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

  3. Cadmium ban spurs interest in zinc-nickel coating for corrosive aerospace environments

    Energy Technology Data Exchange (ETDEWEB)

    Bates, J. (Pure Coatings Inc., West Palm Beach, FL (United States))

    1994-02-01

    OSHA recently reduced the permissible exposure level for cadmium. The new standard virtually outlaws cadmium production and use, except in the most cost-insensitive applications. Aerospace manufacturers, which use cadmium extensively in coatings applications because of the material's corrosion resistance, are searching for substitutes. The most promising alternative found to date is a zinc-nickel alloy. Tests show that the alloy outperforms cadmium without generating associated toxicity issues. As a result, several major manufacturing and standards organizations have adopted the zinc-nickel compound as a standard cadmium replacement. The basis for revising the cadmium PEL -- which applies to occupational exposure in industrial, agricultural and maritime occupations -- is an official OSHA determination that employees exposed to cadmium under the existing PEL face significant health risks from lung cancer and kidney damage. In one of its principal uses, cadmium is electroplated to steel, where it acts as an anticorrosive agent.

  4. Phosphate-enhanced cytotoxicity of zinc oxide nanoparticles and agglomerates.

    Science.gov (United States)

    Everett, W Neil; Chern, Christina; Sun, Dazhi; McMahon, Rebecca E; Zhang, Xi; Chen, Wei-Jung A; Hahn, Mariah S; Sue, H-J

    2014-02-10

    Zinc oxide (ZnO) nanoparticles (NPs) have been found to readily react with phosphate ions to form zinc phosphate (Zn3(PO4)2) crystallites. Because phosphates are ubiquitous in physiological fluids as well as waste water streams, it is important to examine the potential effects that the formation of Zn3(PO4)2 crystallites may have on cell viability. Thus, the cytotoxic response of NIH/3T3 fibroblast cells was assessed following 24h of exposure to ZnO NPs suspended in media with and without the standard phosphate salt supplement. Both particle dosage and size have been shown to impact the cytotoxic effects of ZnO NPs, so doses ranging from 5 to 50 μg/mL were examined and agglomerate size effects were investigated by using the bioinert amphiphilic polymer polyvinylpyrrolidone (PVP) to generate water-soluble ZnO ranging from individually dispersed 4 nm NPs up to micron-sized agglomerates. Cell metabolic activity measures indicated that the presence of phosphate in the suspension media can led to significantly reduced cell viability at all agglomerate sizes and at lower ZnO dosages. In addition, a reduction in cell viability was observed when agglomerate size was decreased, but only in the phosphate-containing media. These metabolic activity results were reflected in separate measures of cell death via the lactate dehydrogenase assay. Our results suggest that, while higher doses of water-soluble ZnO NPs are cytotoxic, the presence of phosphates in the surrounding fluid can lead to significantly elevated levels of cell death at lower ZnO NP doses. Moreover, the extent of this death can potentially be modulated or offset by tuning the agglomerate size. These findings underscore the importance of understanding how nanoscale materials can interact with the components of surrounding fluids so that potential adverse effects of such interactions can be controlled. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  5. Lead-iron phosphate glass: a stable storage medium for high-level nuclear waste

    International Nuclear Information System (INIS)

    Sales, B.C.; Boatner, L.A.

    1984-01-01

    Results are presented which show that lead-iron phosphate glasses are a promising new waste form for the safe immobilization of both high-level defense and high-level commercial radioactive waste. Relative to the borosilicate nuclear waste glasses that are currently the ''reference'' waste form for the long-term disposal of nuclear waste, lead-iron phosphate glasses have several distinct advantages: (1) an aqueous corrosion rate that is about 1000 times lower, (2) a processing temperature that is 100 0 to 250 0 C lower and, (3) a much lower melt viscosity in the temperature range from 800 0 to 1000 0 C. Most significantly, the lead-iron phosphate waste form can be processed using a technology similar to that developed for borosilicate nuclear waste glasses

  6. Structural features of silver-doped phosphate glasses in zone of femtosecond laser-induced modification

    International Nuclear Information System (INIS)

    Vasileva, A.A.; Nazarov, I.A.; Olshin, P.K.; Povolotskiy, A.V.; Sokolov, I.A.; Manshina, A.A.

    2015-01-01

    Femtosecond (fs) laser writing of two-dimensional microstructures (waveguides) is demonstrated in bulk phosphate glasses doped with silver ions. Silver-content phosphate and silver-content niobium–phosphate glasses with high concentration of silver oxide 55 mol% were used as samples for fs laser writing. The chemical network structure of the synthesized samples is analyzed through Raman spectroscopy and was found to be strongly sensitive to Nb incorporation. It was found that the direct laser writing process enables not only reorganization of glass network, but also formation of color centers and silver nanoparticles that are revealed in appearance of luminescence signal and plasmon absorption. The process of NPs' formation is more efficient for Nb-phosphate glass, while color centers are preferably formed in phosphate glass. - Graphical abstract: Formation of silver NPs on the surface of 0.5Ag 2 O–0.4P 2 O 5 –0,1Nb 2 O 5 glass induced by CW laser irradiation. - Highlights: • The structure of 0.5Ag 2 O–0.1Nb 2 O 5 –0.4P 2 O 5 and 0.55Ag 2 O–0.45P 2 O 5 glasses was investigated by Raman spectroscopy. • Fs laser writing induces formation of silver NPs in investigated glasses. • Surface plasmon resonance in the absorption spectra confirms the formation of NP. • The possibility of CW laser induced formation of silver NPs on the surface of sample with niobium is shown

  7. Alkaline resistant phosphate glasses and method of preparation and use thereof

    Science.gov (United States)

    Brow, Richard K.; Reis, Signo T.; Velez, Mariano; Day, Delbert E.

    2010-01-26

    A substantially alkaline resistant calcium-iron-phosphate (CFP) glass and methods of making and using thereof. In one application, the CFP glass is drawn into a fiber and dispersed in cement to produce glass fiber reinforced concrete (GFRC) articles having the high compressive strength of concrete with the high impact, flexural and tensile strength associated with glass fibers.

  8. Binding of nickel and zinc ions with activated carbon prepared from ...

    African Journals Online (AJOL)

    Activated carbon was prepared from sugar cane fibre by carbonizing at 500 oC for 30 minutes. This was followed by activation with ammonium chloride. The activated carbon was characterised in terms of pH, bulk density, ash content, surface area and surface charge. Equilibrium sorption of nickel and zinc ions by the ...

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

    International Nuclear Information System (INIS)

    Kajinami, Akihiko; Harada, Yasushi; Inoue, Shinsuke; Deki, Shigehito; Umesaki, Norimasa

    1999-01-01

    The structure of zinc borate glass has been investigated by laboratory EXAFS and X-ray diffraction measurement as preliminary investigations for the detailed study in SPring-8. The zinc borate glass was prepared in the range from 40 to 65 mol% of zinc oxide content. The X-ray diffraction was measured by horizontal θ-θ goniometer with 60 kV and 300 mA output of Mo target. The EXAFS of zinc borate glass was measured by laboratory EXAFS system with 20 kV, 100 mA output of Mo target for the K absorption edge of zinc atom. From the X-ray diffraction and the EXAFS measurements, it is found that the zinc ion is surrounded by four oxygen atoms and formed a tetrahedral structure whose (Zn-O) distance is about 2 A and that the structure is unchanged with the zinc oxide content. The diffraction data show that the neighboring structure of boron atom transforms from BO 4 tetrahedra to BO 3 tetragonal planar structure with increasing of the zinc oxide content. (author)

  10. Mechanical behaviour of degradable phosphate glass fibres and composites-a review.

    Science.gov (United States)

    Colquhoun, R; Tanner, K E

    2015-12-23

    Biodegradable materials are potentially an advantageous alternative to the traditional metallic fracture fixation devices used in the reconstruction of bone tissue defects. This is due to the occurrence of stress shielding in the surrounding bone tissue that arises from the absence of mechanical stimulus to the regenerating bone due to the mismatch between the elastic modulus of bone and the metal implant. However although degradable polymers may alleviate such issues, these inert materials possess insufficient mechanical properties to be considered as a suitable alternative to current metallic devices at sites of sufficient mechanical loading. Phosphate based glasses are an advantageous group of materials for tissue regenerative applications due to their ability to completely degrade in vivo at highly controllable rates based on the specific glass composition. Furthermore the release of the glass's constituent ions can evoke a therapeutic stimulus in vivo (i.e. osteoinduction) whilst also generating a bioactive response. The processing of these materials into fibres subsequently allows them to act as reinforcing agents in degradable polymers to simultaneously increase its mechanical properties and enhance its in vivo response. However despite the various review articles relating to the compositional influences of different phosphate glass systems, there has been limited work summarising the mechanical properties of different phosphate based glass fibres and their subsequent incorporation as a reinforcing agent in degradable composite materials. As a result, this review article examines the compositional influences behind the development of different phosphate based glass fibre compositions intended as composite reinforcing agents along with an analysis of different potential composite configurations. This includes variations in the fibre content, matrix material and fibre architecture as well as other novel composites designs.

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

    OpenAIRE

    Ruengsri, Suwimon

    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...

  12. Structural features of silver-doped phosphate glasses in zone of femtosecond laser-induced modification

    Energy Technology Data Exchange (ETDEWEB)

    Vasileva, A.A., E-mail: anvsilv@gmail.com [Saint-Petersburg State University, Institute of Chemistry, Saint-Petersburg (Russian Federation); Nazarov, I.A. [Saint-Petersburg State University, Department of Physics, Saint-Petersburg (Russian Federation); Olshin, P.K.; Povolotskiy, A.V. [Saint-Petersburg State University, Institute of Chemistry, Saint-Petersburg (Russian Federation); Sokolov, I.A. [St.Petersburg State Polytechnical University, St.Petersburg (Russian Federation); LTD “AtomTjazhMash”, St.Petersburg (Russian Federation); Manshina, A.A. [Saint-Petersburg State University, Institute of Chemistry, Saint-Petersburg (Russian Federation)

    2015-10-15

    Femtosecond (fs) laser writing of two-dimensional microstructures (waveguides) is demonstrated in bulk phosphate glasses doped with silver ions. Silver-content phosphate and silver-content niobium–phosphate glasses with high concentration of silver oxide 55 mol% were used as samples for fs laser writing. The chemical network structure of the synthesized samples is analyzed through Raman spectroscopy and was found to be strongly sensitive to Nb incorporation. It was found that the direct laser writing process enables not only reorganization of glass network, but also formation of color centers and silver nanoparticles that are revealed in appearance of luminescence signal and plasmon absorption. The process of NPs' formation is more efficient for Nb-phosphate glass, while color centers are preferably formed in phosphate glass. - Graphical abstract: Formation of silver NPs on the surface of 0.5Ag{sub 2}O–0.4P{sub 2}O{sub 5}–0,1Nb{sub 2}O{sub 5} glass induced by CW laser irradiation. - Highlights: • The structure of 0.5Ag{sub 2}O–0.1Nb{sub 2}O{sub 5}–0.4P{sub 2}O{sub 5} and 0.55Ag{sub 2}O–0.45P{sub 2}O{sub 5} glasses was investigated by Raman spectroscopy. • Fs laser writing induces formation of silver NPs in investigated glasses. • Surface plasmon resonance in the absorption spectra confirms the formation of NP. • The possibility of CW laser induced formation of silver NPs on the surface of sample with niobium is shown.

  13. Structural and thermochemical properties of sodium magnesium phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Oueslati Omrani, Refka [Université de Tunis El Manar, Faculté des Sciences de Tunis, Chemistry Department, LR01SE10 Applied Thermodynamics Laboratory, 2092 Tunis (Tunisia); Kaoutar, Abdeltif; El Jazouli, Abdelaziz [LCMS, URAC 17, Faculté des Sciences Ben M’Sik, UH2MC, Casablanca (Morocco); Krimi, Saida [LPCMI, Faculté des Sciences Aïn Chok, UH2C, Casablanca (Morocco); Khattech, Ismail, E-mail: ismail.khattech@fst.rnu.tn [Université de Tunis El Manar, Faculté des Sciences de Tunis, Chemistry Department, LR01SE10 Applied Thermodynamics Laboratory, 2092 Tunis (Tunisia); Jemal, Mohamed [Université de Tunis El Manar, Faculté des Sciences de Tunis, Chemistry Department, LR01SE10 Applied Thermodynamics Laboratory, 2092 Tunis (Tunisia); Videau, Jean-Jacques [ICMCB, Institut de Chimie de la matière condensée, Université de Bordeaux 1 (France); Couzi, Michel [Institut des Sciences Moléculaires, CNRS-Université de Bordeaux 1 (France)

    2015-05-25

    Highlights: • Phosphate glasses were prepared by met quenching technique. • Structural study is investigated using FTIR, Raman and {sup 31}PNMR spectroscopy. • A 4.5% weight of H{sub 3}PO{sub 4} solution has use for glass dissolution. • Dissolution is endothermic for lower MgO content and becomes exothermic when x rises. - Abstract: Ternary phosphate based glasses with the general formula (50−x/2)Na{sub 2}O–xMgO–(50−x/2)P{sub 2}O{sub 5} (0 ⩽ x ⩽ 42.8 mol%), where the O/P ratio was varied from 3 to 3.75, have been prepared using a conventional melt quenching technique. Samples were investigated by means of density measurements, Fourier-transformed infrared (FTIR), Raman and {sup 31}P solid state magic angle spinning nuclear magnetic resonance (MAS-NMR) spectroscopies, differential scanning calorimetry (DSC), inductively coupled plasma atomic emission spectroscopy (ICP/AES) analysis and calorimetric dissolution. The depolymerization of metaphosphate chains are described by the decrease of Q{sup 2} tetrahedral sites allowing the formation of pyrophosphate groups (Q{sup 1}) revealed by spectroscopic investigations. As a result, the increase of density and glass transition temperature when x rises. Calorimetric study shows that the dissolution phenomenon is endothermic for a lower MgO content and becomes exothermic when magnesium oxide is gradually incorporated, suggesting the disruption of phosphate chains with increasing O/P ratio.

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

    International Nuclear Information System (INIS)

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

    2007-01-01

    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

  15. A simple method for tuning the glass transition process in inorganic phosphate glasses

    Science.gov (United States)

    Fulchiron, René; Belyamani, Imane; Otaigbe, Joshua U.; Bounor-Legaré, Véronique

    2015-02-01

    The physical modification of glass transition temperature (Tg) and properties of materials via blending is a common practice in industry and academia and has a large economic advantage. In this context, simple production of hitherto unattainable new inorganic glass blends from already existing glass compositions via blending raises much hope with the potential to provide new glasses with new and improved properties, that cannot be achieved with classical glass synthesis, for a plethora of applications such as computers screens, glass-to-metal seals, and storage materials for nuclear wastes. Here, we demonstrate that blends of the specific glass compositions studied are miscible in all proportions, an unreported phenomenon in hard condensed matter like glass. Interestingly, excellent agreement was found between the obtained data and calculated Tgs from theoretical equations (Supplementary information) for predicting the composition dependence of Tg for miscible blends with weak but significant specific interactions between the blend components. That this blending method is at present not applied to inorganic glasses reflects the fact that water and chemically resistant phosphate glasses with relatively low Tgs have become available only recently.

  16. A new paramagnetic center of copper ion γ-irradiated phosphate glasses

    International Nuclear Information System (INIS)

    Bogomolova, L.D.; Fedorov, A.G.; Jachkin, V.A.; Lazukin, V.N.; Pavlushkina, T.K.

    1981-01-01

    In the present paper are shown the results of EPR and optical absorption investigations of copper ions in γ-irradiated sodium-phosphate glasses and in MO-P 2 O 5 glasses (M = MG,Ca, Sr, Zn, Ba) containing copper and comparisons are made with the data for sodium-silicate glasses. (orig./HOF)

  17. Charge-discharge characteristics of nickel/zinc battery with polymer hydrogel electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Iwakura, Chiaki; Murakami, Hiroki; Nohara, Shinji; Furukawa, Naoji; Inoue, Hiroshi [Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Sakai, Osaka 599-8531 (Japan)

    2005-12-01

    A new nickel/zinc (Ni/Zn) battery was assembled by using polymer hydrogel electrolyte prepared from cross-linked potassium poly(acrylate) and KOH aqueous solution, and its charge-discharge characteristics were investigated. The experimental Ni/Zn cell with the polymer hydrogel electrolyte exhibited well-defined charge-discharge curves and remarkably improved charge-discharge cycle performance, compared to that with a KOH aqueous solution. Moreover, it was found that dendritic growth hardly occurred on the zinc electrode surface during charge-discharge cycles in the polymer hydrogel electrolyte. These results indicate that the polymer hydrogel electrolyte can successfully be used in Ni/Zn batteries as an electrolyte with excellent performance. (author)

  18. Charge-discharge characteristics of nickel/zinc battery with polymer hydrogel electrolyte

    Science.gov (United States)

    Iwakura, Chiaki; Murakami, Hiroki; Nohara, Shinji; Furukawa, Naoji; Inoue, Hiroshi

    A new nickel/zinc (Ni/Zn) battery was assembled by using polymer hydrogel electrolyte prepared from cross-linked potassium poly(acrylate) and KOH aqueous solution, and its charge-discharge characteristics were investigated. The experimental Ni/Zn cell with the polymer hydrogel electrolyte exhibited well-defined charge-discharge curves and remarkably improved charge-discharge cycle performance, compared to that with a KOH aqueous solution. Moreover, it was found that dendritic growth hardly occurred on the zinc electrode surface during charge-discharge cycles in the polymer hydrogel electrolyte. These results indicate that the polymer hydrogel electrolyte can successfully be used in Ni/Zn batteries as an electrolyte with excellent performance.

  19. Eco-physiological studies on the uptake of the pollutants, copper, zinc and phosphate, by certain algae

    Energy Technology Data Exchange (ETDEWEB)

    Rana, B C; Kumar, H D

    1974-01-01

    Certain algae isolated from polluted and nonpolluted habitats were studied for their capacity to absorb copper, zinc, and phosphate from the ambient medium. They were found to possess a high gleaning capacity for these pollutants. The uptake of copper does not seem to require much metabolic energy and is independent of the growth of the alga, but the uptake of zinc seems to depend directly on its growth. Anacystis nidulans and Chlorella vulgaris are fast growing algae; they can absorb high amounts of phosphate and can be gainfully employed for retrieving the phosphate from the medium. However, the algae must be harvested before they excrete some of the phosphates back into the medium.

  20. Formation of cellular films consisting of wurtzite-type zinc oxide nanosheets by mediation of phosphate anions

    International Nuclear Information System (INIS)

    Yamabi, Satoshi; Yahiro, Junko; Iwai, Satoko; Imai, Hiroaki

    2005-01-01

    We successfully prepared a wide variety of wurtzite-type zinc oxide films exhibiting columnar, cellular and densely packed morphologies in a simple aqueous solution system containing phosphate anions. As the phosphate concentration increased, the shape of crystalline units composing the films varied from hexagonal needles into seaweed-like sheets. A novel type of open cellular structures was obtained by assembly of nanoscale zinc oxide sheets covered with phosphate. Specific adsorption of phosphate anions on (001) of the wurtzite-type crystal flattened the crystal grains, and then induced the structural evolution into a cellular form. A blue shift of the absorption edge suggested that the quantum size effect occurred in the nanoscale platy crystals composing the cellular films

  1. Study of multicomponent fluoro-phosphate based glasses: Ho3+ as a luminescence center

    International Nuclear Information System (INIS)

    Babu, S.; Seshadri, M.; Balakrishna, A.; Reddy Prasad, V.; Ratnakaram, Y.C.

    2015-01-01

    The multicomponent 49.5P 2 O 5 –10AlF 3 –10BaF 2 –10SrF 2 –10PbO–10M (M=Li 2 O, Na 2 O, K 2 O, ZnO and Bi 2 O 3 ) glasses doped with 0.5 mol% holmium were prepared by melt quenching technique. Their thermal behavior was examined from differential scanning calorimetry (DSC). It is found that bismuth fluoro-phosphate glass matrix has good thermal stability. Their structures were characterized by the X-ray diffraction with SEM analysis, fourier transform infrared (FTIR), Raman spectroscopy and magic angle spinning (MAS) nuclear magnetic resonance (NMR) techniques. It was found that the phosphate network of these glasses was composed mainly of Q 2 and Q 3 phosphate tetrahedral units. The Judd–Ofelt parameters (J–O) (Ω 2 , Ω 4 and Ω 6 ) were evaluated from the intensities of the energy levels through optical absorption spectra. The most intense transitions are observed in the visible region of the spectrum. It is observed that the transition 5 I 8 → 5 G 6 is the hypersensitive transition for Ho 3+ ion. With these J–O parameters, various radiative properties like the probabilities of radiative transitions, radiative lifetimes and branching ratios have been calculated for different fluoro-phosphate glasses. The luminescence kinetics from excited holmium levels have been studied upon selective excitation through photoluminescence measurements. Holmium produces two visible laser emissions i.e. one is green ( 5 F 4 ( 5 S 2 )→ 5 I 8 ) and another one is red ( 5 F 5 → 5 I 8 ). The lifetimes of these levels have been experimentally determined through decay profile studies. The above results suggest that the prepared bismuth fluoro-phosphate glass system could be a suitable candidate for using it as a green laser source ( 5 F 4 ( 5 S 2 )→ 5 I 8 ) in the visible region of the spectrum. - Highlights: • Holmium doped different fluoro-phosphate glasses were prepared and characterized. • Structural, thermal and spectroscopic properties have been studied

  2. Ferric oxide quantum dots in stable phosphate glass system and their magneto-optical study

    Energy Technology Data Exchange (ETDEWEB)

    Garaje, Sunil N.; Apte, Sanjay K. [Nanocomposite Group, Centre for Materials for Electronics Technology (C-MET), Department of Electronics and Information Technology (DeitY), Government of India, Panchawati, Off Pashan Road, Pune 411008 (India); Kumar, Ganpathy [Department of Electrical and Computer Engineering, Tennessee Technological University, 1 William L. Jones Drive, Cookeville, TN 38505 (United States); Panmand, Rajendra P.; Naik, Sonali D. [Nanocomposite Group, Centre for Materials for Electronics Technology (C-MET), Department of Electronics and Information Technology (DeitY), Government of India, Panchawati, Off Pashan Road, Pune 411008 (India); Mahajan, Satish M., E-mail: smahajan@tntech.edu [Department of Electrical and Computer Engineering, Tennessee Technological University, 1 William L. Jones Drive, Cookeville, TN 38505 (United States); Chand, Ramesh [Ministry of Communications and Information Technology, Department of Electronics and Information Technology (DeitY), Electronics Niketan, 6, CGO Complex, New Delhi 110003 (India); Kale, Bharat B., E-mail: bbkale@cmet.gov.in [Nanocomposite Group, Centre for Materials for Electronics Technology (C-MET), Department of Electronics and Information Technology (DeitY), Government of India, Panchawati, Off Pashan Road, Pune 411008 (India)

    2013-02-15

    Graphical abstract: We report synthesis of ferric oxide embedded low melting phosphate glass nanocomposite and also the effect of ferric oxide nanoparticles (NCs) content on the optical and magneto-optical properties of the glasses. Faraday rotation of the glass nanocomposites was measured and showed variation in Verdet constant with concentration of ferric oxide. Interestingly, the host glass itself showed fairly good Verdet constant (11.5°/T cm) and there is a threefold enhancement in the Verdet constant of ferric oxide quantum dot-glass nanocomposite. Highlights: ► We synthesize ferric oxide embedded low melting stable phosphate glass nanocomposite. ► Glasses doped with 0.25 and 2% ferric oxide show particle size in the range of 4–12 nm. ► The host phosphate glass itself shows fairly good Verdet constant (11.5°/T cm). ► Glasses doped with 0.25% ferric oxide show high Verdet constant (30.525°/T cm). ► The as synthesis glasses may have potential application in magneto optical devices. -- Abstract: Herein, we report the synthesis of ferric oxide embedded low melting phosphate glass nanocomposite and also the effect of ferric oxide nanoparticles content on the optical and magneto-optical properties of the glasses. The optical study clearly showed red shift in optical cut off with increasing ferric oxide concentration. The band gap of the host glass was observed to be 3.48 eV and it shifted to 3.14 eV after doping with ferric oxide. The glasses doped with 0.25 and 2% ferric oxide showed particle size of 4–6 nm and 8–12 nm, respectively. Faraday rotation of the glass nanocomposites was measured and showed variation in the Verdet constant as per increasing concentration of ferric oxide. Interestingly, the host glass itself showed fairly good Verdet constant (11.5°/T cm) and threefold enhancement was observed in the Verdet constant of ferric oxide quantum dot-glass nanocomposite.

  3. A Review of Iron Phosphate Glasses and Recommendations for Vitrifying Hanford Waste

    Energy Technology Data Exchange (ETDEWEB)

    Delbert E. Ray; Chandra S. Ray

    2013-11-01

    This report contains a comprehensive review of the research conducted, world-wide, on iron phosphate glass over the past ~30 years. Special attention is devoted to those iron phosphate glass compositions which have been formulated for the purpose of vitrifying numerous types of nuclear waste, with special emphasis on the wastes stored in the underground tanks at Hanford WA. Data for the structural, chemical, and physical properties of iron phosphate waste forms are reviewed for the purpose of understanding their (a) outstanding chemical durability which meets all current DOE requirements, (b) high waste loadings which can exceed 40 wt% (up to 75 wt%) for several Hanford wastes, (c) low melting temperatures, can be as low as 900°C for certain wastes, and (d) high tolerance for “problem” waste components such as sulfates, halides, and heavy metals (chromium, actinides, noble metals, etc.). Several recommendations are given for actions that are necessary to smoothly integrate iron phosphate glass technology into the present waste treatment plans and vitrification facilities at Hanford.

  4. Influence de la phosphatation au zinc sur la résistance a la ...

    African Journals Online (AJOL)

    Zinc phosphatation influence on the resistance to corrosion of a carbonbased steel in marine medium. In the frame of the present investigation, we have showed that the profile of the cathodic curves of a non phosphated metal, plead in favour to a kinetic profile essentially monitored by a pure diffusion. The corrosion rate ...

  5. The influence of SrO and CaO in silicate and phosphate bioactive glasses on human gingival fibroblasts.

    Science.gov (United States)

    Massera, J; Kokkari, A; Närhi, T; Hupa, L

    2015-06-01

    In this paper, we investigate the effect of substituting SrO for CaO in silicate and phosphate bioactive glasses on the human gingival fibroblast activity. In both materials the presence of SrO led to the formation of a CaP layer with partial Sr substitution for Ca. The layer at the surface of the silicate glass consisted of HAP whereas at the phosphate glasses it was close to the DCPD composition. In silicate glasses, SrO gave a faster initial dissolution and a thinner reaction layer probably allowing for a continuous ion release into the solution. In phosphate glasses, SrO decreased the dissolution process and gave a more strongly bonded reaction layer. Overall, the SrO-containing silicate glass led to a slight enhancement in the activity of the gingival fibroblasts cells when compared to the SrO-free reference glass, S53P4. The cell activity decreased up to 3 days of culturing for all phosphate glasses containing SrO. Whereas culturing together with the SrO-free phosphate glass led to complete cell death at 7 days. The glasses containing SrO showed rapid cell proliferation and growth between 7 and 14 days, reaching similar activity than glass S53P4. The addition of SrO in both silicate and phosphate glasses was assumed beneficial for proliferation and growth of human gingival fibroblasts due to Sr incorporation in the reaction layer at the glass surface and released in the cell culture medium.

  6. Effect of various parameters on the efficiency of zinc phosphate ...

    African Journals Online (AJOL)

    ... and CMG852 showed enhanced solubilization in presence of 1% sodium chloride. 1% glucose is required for the solubilization of zinc phosphate and no solubilization was appeared in presence of 0.1% glucose. CMG851 (A. lwoffi), CMG 860 (pseudomonas aeruginosa) CMG 857 (Bacillus thuringiensis) were found to be ...

  7. Nanoscale mechanochemical wear of phosphate laser glass against a CeO{sub 2} particle in humid air

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Jiaxin, E-mail: yujiaxin@swust.edu.cn [Key Laboratory of Testing Technology for Manufacturing Process, Ministry of Education, Southwest University of Science and Technology, Mianyang 621010 (China); He, Hongtu; Zhang, Yafeng [Key Laboratory of Testing Technology for Manufacturing Process, Ministry of Education, Southwest University of Science and Technology, Mianyang 621010 (China); Hu, Hailong [Analysis and Testing Center, Southwest University of Science and Technology, Mianyang 621010 (China)

    2017-01-15

    Highlights: • Friction components of phosphate glass/CeO{sub 2} pair in humid air were quantified to understand the friction mechanism. • Severe nanoscale wear was directly observed by AFM topography on both phosphate glass and CeO{sub 2} particle in humid air. • The wearless behaviors of phosphate glass in vacuum were confirmed by the AFM phase image. • Capillary water bridge induced corrosion plays an important role in the mechanochemical wear of phosphate glass in air. - Abstract: Using an atomic force microscope, the friction and wear of phosphate laser glass against a CeO{sub 2} particle were quantitatively studied both in humid air and in vacuum, to reveal the water molecules induced mechanochemical wear mechanism of phosphate laser glass. The friction coefficient of the glass/CeO{sub 2} pair in air was found to be 5–7 times higher than that in vacuum due to the formation of a capillary water bridge at the friction interface, with a contribution of the capillary-related friction to the total friction coefficient as high as 65–79%. The capillary water bridge further induced a serious material removal of glass and CeO{sub 2} particle surfaces, while supplying both a local liquid water environment to corrode the glass surface and a high shearing force to assist the stretching of the Ce−O−P bond, accelerating the reaction between water and the glass/CeO{sub 2} pair. In vacuum, however, no discernable wear phenomena were observed, but the phase images captured by AFM tapping mode suggested the occurrence of potential strain hardening in the friction area of the glass surface.

  8. Zinc bioaccumulation by microbial consortium isolated from nickel smelter sludge disposal site

    Directory of Open Access Journals (Sweden)

    Kvasnová Simona

    2017-06-01

    Full Text Available Heavy metal pollution is one of the most important environmental issues of today. Bioremediation by microorganisms is one of technologies extensively used for pollution treatment. In this study, we investigated the heavy metal resistance and zinc bioaccumulation by microbial consortium isolated from nickel sludge disposal site near Sereď (Slovakia. The composition of consortium was analyzed based on MALDI-TOF MS of cultivable bacteria and we have shown that the consortium was dominated by bacteria of genus Arthrobacter. While consortium showed very good growth in the zinc presence, it was able to remove only 15 % of zinc from liquid media. Selected members of consortia have shown lower growth rates in the zinc presence but selected isolates have shown much higher bioaccumulation abilities compared to whole consortium (up to 90 % of zinc removal for NH1 strain. Bioremediation is frequently accelerated through injection of native microbiota into a contaminated area. Based on data obtained in this study, we can conclude that careful selection of native microbiota could lead to the identification of bacteria with increased bioaccumulation abilities.

  9. WO.sub.3./sub.-doped zinc borophosphate glasses

    Czech Academy of Sciences Publication Activity Database

    Šubčík, J.; Koudelka, L.; Mošner, P.; Gregora, Ivan; Montagne, L.; Revel, B.

    2009-01-01

    Roč. 50, č. 4 (2009), 243-248 ISSN 1753-3562 R&D Projects: GA AV ČR KAN301370701 Institutional research plan: CEZ:AV0Z10100520 Keywords : tungstate zinc borophosphate glasses * Raman spectroscopy * temperature * NMR Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.553, year: 2009

  10. Biological performance of titania containing phosphate-based glasses for bone tissue engineering applications

    International Nuclear Information System (INIS)

    Abou Neel, Ensanya Ali; Chrzanowski, Wojciech; Knowles, Jonathan Campbell

    2014-01-01

    The interplay between glass chemistry, structure, degradation kinetics, and biological activity provides flexibility for the development of scaffolds with highly specific cellular response. The aim of this study was therefore to investigate the role of titania inclusion into the phosphate-based glass on its ability to stimulate osteoblast-like human osteosarcoma (HOS) cells to adhere, proliferate and differentiate. In depth morphological and biochemical characterisation was performed on HOS cells cultured on the surface of glass discs. Cell proliferation was also studied in the presence of the glass extract. Cell differentiation, through osteoblast phenotype genes, alkaline phosphatase (ALP) activity and osteocalcin production, was carried out using normal or osteogenic media. Both Thermanox® and titania free glass were used as controls. The data demonstrated that titania inclusion provides desired cytocompatible surface that supported initial cell attachment, sustained viability, and increased cell proliferation similar or significantly higher than Thermanox®. The modified glasses regulated osteoblastic cell differentiation as detected by osteoblast phenotype gene transcription and upregulated ALP and osteocalcin expression. Using osteogenic media had no significant effect on ALP activity and osteocalcin expression. Therefore, titania modified phosphate glasses may have future use as bone tissue engineering scaffolds. - Highlights: • This study investigated the role of titania on the biological response of phosphate glasses. • Incorporation of titania improved HOS cell attachment, viability and proliferation. • Titania modified glasses regulated osteoblastic cell differentiation. • Using osteogenic media had no significant effect on cell differentiation. • Titania modified glasses may have future use as bone tissue engineering scaffolds

  11. Simulation of alpha decay of actinides in iron phosphate glasses by ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Dube, Charu L., E-mail: dubecharu@gmail.com; Stennett, Martin C.; Gandy, Amy S.; Hyatt, Neil C.

    2016-03-15

    Highlights: • Alpha decay of actinides in iron phosphate glasses is simulated by employing ion irradiation technique. • FTIR and Raman spectroscopic measurements confirm modification of glass network. • The depolymerisation of glass network after irradiation is attributed to synergetic effect of nuclear and electronic losses. - Abstract: A surrogate approach of ion beam irradiation is employed to simulate alpha decay of actinides in iron phosphate nuclear waste glasses. Bismuth and helium ions of different energies have been selected for simulating glass matrix modification owing to radiolysis and ballistic damage due to recoil atoms. Structural modification and change in coordination number of network former were probed by employing Reflectance Fourier-Transform Infrared (FT-IR), and Raman spectroscopies as a consequence of ion irradiation. Depolymerisation is observed in glass sample irradiated at intermediate energy of 2 MeV. Helium blisters of micron size are seen in glass sample irradiated at low helium ion energy of 30 keV.

  12. Role of lead as modifier on the properties of lead iron phosphate nuclear waste glasses

    International Nuclear Information System (INIS)

    Hazra, G.; Mitra, P.; Das, T.

    2011-01-01

    Lead-iron phosphate glasses are a promising new waste form for the safe immobilization of both high level defence and high level commercial radioactive waste for long term disposal. Lead iron phosphate glasses have several advantages such as lower aqueous corrosion rate, lower processing temperature etc. (author)

  13. Photo-Electrochemical Effect of Zinc Addition on the Electrochemical Corrosion Potentials of Stainless Steels and Nickel Alloys in High Temperature Water

    International Nuclear Information System (INIS)

    Lee, Yi-Ching; Fong, Clinton; Fang-Chu, Charles; Chang, Ching

    2012-09-01

    Hydrogen water chemistry (HWC) is one of the main mitigating methods for stress corrosion cracking problem of reactor core stainless steel and nickel based alloy components. Zinc is added to minimize the radiation increase associated with HWC. However, the subsequently formed zinc-containing surface oxides may exhibit p-type semiconducting characteristics. Upon the irradiation of Cherenkov and Gamma ray in the reactor core, the ECP of stainless steels and nickel based alloys may shift in the anodic direction, possibly offsetting the beneficial effect of HWC. This study will evaluate the photo-electrochemical effect of Zinc Water Chemistry on SS304 stainless steel and Alloy 182 nickel based weld metal under simulated irradiated BWR water environments with UV illumination. The experimental results reveal that Alloy 182 nickel-based alloy generally possesses n-type semiconductor characteristics in both oxidizing NWC and reducing HWC conditions with zinc addition. Upon UV irradiation, the ECP of Alloy 182 will shift in the cathodic direction. In most conditions, SS304 will also exhibit n-type semiconducting properties. Only under hydrogen water chemistry, a weak p-type property may emerge. Only a slight upward shift in the anodic direction is detected when SS304 is illuminated with UV light. The potential influence of p-type semiconductor of zinc containing surface oxides is weak and the mitigation effect of HWC on the stress corrosion cracking is not adversely affected. (authors)

  14. Studies on the synthesis and characterization of cesium-containing iron phosphate glasses

    Science.gov (United States)

    Joseph, Kitheri; Govindan Kutty, K. V.; Chandramohan, P.; Vasudeva Rao, P. R.

    2009-02-01

    Isotopes of cesium and strontium can be utilized as radiation source for various industrial and medical applications after their separation from high level nuclear waste. However, these elements need to be immobilized in a suitable matrix. In the present work, a systematic approach has been made to immobilize inactive cesium into iron phosphate glass. Up to 36 mol% of Cs 2O has been loaded successfully without crystallization. The glass transition temperature of the cesium loaded glass was found to increase initially and then decrease as a function of Cs 2O content. Mössbauer studies show that the concentration of Fe 3+ ions in the cesium loaded glasses is >95%. Volatilization experiments at 1263 K show that the weight loss is >0.5% for a period of 4 h. The 36 mol% of Cs 2O loaded iron phosphate glass with high Fe 3+ content described in this paper is reported for the first time.

  15. Environmental implications of element emissions from phosphate-processing operations in southeastern Idaho

    Science.gov (United States)

    Severson, R.C.; Gough, L.P.

    1979-01-01

    In order to assess the contribution to plants and soils of certain elements emitted by phosphate processing, we sampled sagebrush, grasses, and A- and C-horizon soils along upwind and downwind transects at Pocatello and Soda Springs, Idaho. Analyses for 70 elements in plants showed that, statistically, the concentration of 7 environmentally important elements, cadmium, chromium, fluorine, selenium, uranium, vanadium, and zinc, were related to emissions from phosphate-processing operations. Two additional elements, lithium and nickel, show probable relationships. The literature on the effects of these elements on plant and animal health is briefly surveyed. Relations between element content in plants and distance from the phosphate-processing operations were stronger at Soda Springs than at Pocatello and, in general, stronger in sagebrush than in the grasses. Analyses for 58 elements in soils showed that, statistically, beryllium, fluorine, iron, lead, lithium, potassium, rubidium, thorium, and zinc were related to emissions only at Pocatello and only in the A horizon. Moreover, six additional elements, copper, mercury, nickel, titanium, uranium, and vanadium, probably are similarly related along the same transect. The approximate amounts of elements added to the soils by the emissions are estimated. In C-horizon soils, no statistically significant relations were observed between element concentrations and distance from the processing sites. At Soda Springs, the nonuniformity of soils at the sampling locations may have obscured the relationship between soil-element content and emissions from phosphate processing.

  16. Ytterbium-Phosphate Glass for Microstructured Fiber Laser

    Directory of Open Access Journals (Sweden)

    Ryszard Stępień

    2014-06-01

    Full Text Available In the paper, we report on the development of a synthesis and melting method of phosphate glasses designed for active microstructured fiber manufacturing. Non-doped glass synthesized in a P2O5-Al2O3-BaO-ZnO-MgO-Na2O oxide system served as the matrix material; meanwhile, the glass was doped with 6 mol% (18 wt% of Yb2O3, as fiber core. The glasses were well-fitted in relation to optical (refractive index and thermal proprieties (thermal expansion coefficient, rheology. The fiber with the Yb3+-doped core, with a wide internal photonic microstructure for a laser pump, as well as with a high relative hole size in the photonic outer air-cladding, was produced. The laser built on the basis of this fiber enabled achieving 8.07 W of output power with 20.5% slope efficiency against the launched pump power, in single-mode operation M2 = 1.59, from a 53 cm-long cavity.

  17. Comparative investigation on the spectroscopic properties of Pr3+-doped boro-phosphate, boro-germo-silicate and tellurite glasses

    Science.gov (United States)

    Zhang, Liaolin; Dong, Guoping; Peng, Mingying; Qiu, Jianrong

    We report on the spectroscopic properties of Pr3+-doped boro-phosphate, boro-germo-silicate and tellurite glasses. The stimulated absorption and emission cross sections were estimated. Only one emission at 596 nm and 605 nm is observed in Pr3+-doped boro-phosphate and boro-germo-silicate glasses, respectively, while three emissions at 605 nm, 612 nm and 645 nm are observed in Pr3+-doped tellurite glass when excited at 467 nm. The fluorescence lifetime at 600 nm in Pr3+-doped boro-phosphate, boro-germo-silicate and tellurite glasses is 137 μs, 73 μs and 51 μs, respectively. The emissions from Pr3+-doped boro-phosphate, boro-germo-silicate and tellurite glasses show different decay behaviors and can be well explained by multiphonon relaxation theory.

  18. Preparation and structural characterization of vulcanized natural rubber nanocomposites containing nickel-zinc ferrite nanopowders.

    Science.gov (United States)

    Bellucci, F S; Salmazo, L O; Budemberg, E R; da Silva, M R; Rodríguez-Pérez, M A; Nobre, M A L; Job, A E

    2012-03-01

    Single-phase polycrystalline mixed nickel-zinc ferrites belonging to Ni0.5Zn0.5Fe2O4 were prepared on a nanometric scale (mean crystallite size equal to 14.7 nm) by chemical synthesis named the modified poliol method. Ferrite nanopowder was then incorporated into a natural rubber matrix producing nanocomposites. The samples were investigated by means of infrared spectroscopy, X-ray diffraction, scanning electron microscopy and magnetic measurements. The obtained results suggest that the base concentration of nickel-zinc ferrite nanoparticles inside the polymer matrix volume greatly influences the magnetic properties of nanocomposites. A small quantity of nanoparticles, less than 10 phr, in the nanocomposite is sufficient to produce a small alteration in the semi-crystallinity of nanocomposites observed by X-ray diffraction analysis and it produces a flexible magnetic composite material with a saturation magnetization, a coercivity field and an initial magnetic permeability equal to 3.08 emu/g, 99.22 Oe and 9.42 x 10(-5) respectively.

  19. The effects of uranium on the structure of iron phosphate glasses

    International Nuclear Information System (INIS)

    Badyal, Y.; Karabulut, M.; Marasinghe, K.; Saboungi, M.L.; Haeffner, D.; Shastri, S.; Day, D.E.; Ray, C.S.

    1999-01-01

    Because of their high chemical durability and waste loading capacity, iron phosphate glasses are a natural candidate for a nuclear waste disposal medium. The authors have studied the effects of uranium on the structure of iron phosphate glasses with both neutron and high-energy x-ray diffraction. The results of neutron scattering, which is mostly sensitive to pair correlations involving light atoms, i.e., O-O, Fe-O and P-O, indicate the main structural features of the base glass are largely unaffected by the addition of UO 2 . The nearest-neighbor P-O, Fe-O and O-O peaks remain at the same position in real space and their intensities scale approximately with concentration. These findings are consistent with earlier results using Raman scattering and EXAFS on the Fe-K edge, where in both cases the spectra remain similar to the base glass. The results of high-energy x-ray scattering, which is sensitive to correlations involving the heavier atoms and thus complements the neutron measurements, are also consistent with the overall picture of uranium occupying interstitial sites in the relatively undisturbed base glass structure. Combining the neutron and x-ray data for a 10 mol% UO 2 glass suggests the intriguing possibility of a U 6+ uranyl ion configuration although further work is needed to establish the precise local structure and valence state of uranium in these glasses

  20. Mutual effect of zinc (2) and cadmium (2) during extraction with tributil phosphate from lithium chloride solutions

    International Nuclear Information System (INIS)

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

    1980-01-01

    Mutual effect of zinc and cadmium chlorides during extraction with tributyl phosphate at 5, 25 and 45 deg C from LiCl solutions is studied. The conclusion about the suppression of zinc and cadmium extraction by extracting macroelement (cadmium and zinc correspondingly) as the result of manifestation of general ion effect (lithium ion) in the extraction systems is made. It is established that the suppression of zink and cadmium extraction increases with the temperature decrease. On the base of the obtained experimental data the different type of extraction element distribution curves at the extraction from the muriatic solutions and lithium chloride solutions with tributyl phosphate is discussed

  1. Chitosan–Zinc(II Complexes as a Bio-Sorbent for the Adsorptive Abatement of Phosphate: Mechanism of Complexation and Assessment of Adsorption Performance

    Directory of Open Access Journals (Sweden)

    Maryam Roza Yazdani

    2017-12-01

    Full Text Available This study examines zinc(II–chitosan complexes as a bio-sorbent for phosphate removal from aqueous solutions. The bio-sorbent is prepared and is characterized via Fourier Transform Infrared Spectroscopy (FT-IR, Scanning Electron Microscopy (SEM, and Point of Zero Charge (pHPZC–drift method. The adsorption capacity of zinc(II–chitosan bio-sorbent is compared with those of chitosan and ZnO–chitosan and nano-ZnO–chitosan composites. The effect of operational parameters including pH, temperature, and competing ions are explored via adsorption batch mode. A rapid phosphate uptake is observed within the first three hours of contact time. Phosphate removal by zinc(II–chitosan is favored when the surface charge of bio-sorbent is positive/or neutral e.g., within the pH range inferior or around its pHPZC, 7. Phosphate abatement is enhanced with decreasing temperature. The study of background ions indicates a minor effect of chloride, whereas nitrate and sulfate show competing effect with phosphate for the adsorptive sites. The adsorption kinetics is best described with the pseudo-second-order model. Sips (R2 > 0.96 and Freundlich (R2 ≥ 0.95 models suit the adsorption isotherm. The phosphate reaction with zinc(II–chitosan is exothermic, favorable and spontaneous. The complexation of zinc(II and chitosan along with the corresponding mechanisms of phosphate removal are presented. This study indicates the introduction of zinc(II ions into chitosan improves its performance towards phosphate uptake from 1.45 to 6.55 mg/g and provides fundamental information for developing bio-based materials for water remediation.

  2. Lead-iron phosphate glass as a containment medium for the disposal of high-level nuclear wastes

    Science.gov (United States)

    Boatner, L.A.; Sales, B.C.

    1984-04-11

    Disclosed are lead-iron phosphate glasses containing a high level of Fe/sub 2/O/sub 3/ for use as a storage medium for high-level radioactive nuclear waste. By combining lead-iron phosphate glass with various types of simulated high-level nuclear waste

  3. Modeling of excimer laser radiation induced defect generation in fluoride phosphate glasses

    International Nuclear Information System (INIS)

    Natura, U.; Ehrt, D.

    2001-01-01

    Fluoride phosphate (FP) glasses with low phosphate content are high-transparent in the deep ultraviolet (UV) range and attractive candidates for UV-optics. Their optical properties are complementary to fluoride crystals. The anomalous partial dispersion makes them desirable for optical lens designs to reduce the secondary spectrum. Their UV transmission is limited by trace impurities introduced by raw materials and decreases when exposed to UV-radiation (lamps, lasers). The experiments of the paper published previously in this journal were used in order to separate radiation induced absorption bands in the fluoride phosphate glass FP10. In this paper the generation mechanism of the phosphorus-oxygen related hole center POHC 2 is investigated in detail in glasses of various compositions (various phosphate and impurity contents) in order to predict the transmission loss in case of long-time irradiation. Experiments were carried out using ArF- and KrF-excimer lasers (ns-pulses). POHC 2 generation strongly depends on the phosphate content and on the content of Pb 2+ . A model was developed on these terms. Rate equations are formulated, incorporating the influence of the Pb 2+ -content on the defect generation, a two-step creation term including an energy transfer process and a one-photon bleaching term. This results in a set of coupled nonlinear differential equations. Absorption coefficients and lifetimes of the excited states were calculated as well. Experimental results compared well with the numerical analysis of the theoretical rate equations

  4. AN ALTERNATIVE HOST MATRIX BASED ON IRON PHOSPHATE GLASSES FOR THE VITRIFICATION OF SPECIALIZED WASTE FORMS

    International Nuclear Information System (INIS)

    Day, Delbert D.

    2000-01-01

    As mentioned above, the overall goal of this research project was to collect the scientific information essential to develop iron phosphate glass based nuclear wasteforms. The specific objectives of the project were: (1) Investigate the structure of binary iron phosphate glasses and it's dependence on the composition and melting atmosphere: Understand atomic arrangements and nature of the bonding. Establish structure-property relationships. Determine the compositions and melting conditions which optimize the critical properties of the base glass. (2) Understand the structure of iron phosphate wasteforms and it's dependence on the composition and melting atmosphere: Investigate how the waste elements are bonded and coordinated within the glass structure. Establish structure-property relationships for the waste glasses. Determine the compositions and melting atmosphere for which the critical properties of the waste forms would be optimum. (3) Determine the role(s) played by the valence states of iron ions and it's dependence on the composition and melting atmosphere: Understand the different roles of iron(II) and iron(III) ions in determining the critical properties of the base glass and the waste forms. Investigate how the iron valence and its significance depend on the composition and melting atmosphere. (4) Investigate glass forming and crystallization processes of the iron phosphate glasses and their waste forms: Understand the dependence of the glass forming and crystallization characteristics on overall glass composition and valence states of iron ions. Identify the products of devitrification and investigate the critical properties of these crystalline compounds which may adversely affect the chemical and physical properties of the waste forms

  5. Praseodymium ion doped phosphate glasses for integrated broadband ion-exchanged waveguide amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Shen, L.F. [School of Textile and Material Engineering, Dalian Polytechnic University, Dalian 116034 (China); Department of Electronic Engineering, City University of Hong Kong, Kowloon, Hong Kong (China); Chen, B.J. [Department of Electronic Engineering, City University of Hong Kong, Kowloon, Hong Kong (China); Lin, H., E-mail: lhai8686@yahoo.com [School of Textile and Material Engineering, Dalian Polytechnic University, Dalian 116034 (China); Department of Electronic Engineering, City University of Hong Kong, Kowloon, Hong Kong (China); Pun, E.Y.B. [Department of Electronic Engineering, City University of Hong Kong, Kowloon, Hong Kong (China)

    2015-02-15

    Highlights: • Effective near-infrared emission (1380-1525 nm) is observed in Pr{sup 3+}-doped phosphate glasses. • Effective bandwidth of {sup 1}D{sub 2} → {sup 1}G{sub 4} transition emission is obtained to be 124 nm. • Channel waveguides have been fabricated by K{sup +}-Na{sup +} ion-exchange method. • Pr{sup 3+}-doped phosphate glasses are promising in developing integrated broadband waveguide amplifier. - Abstract: Effective near-infrared emission covering the fifth optical telecommunication window (1380-1525 nm) has been observed in Pr{sup 3+}-doped phosphate (NMAP) glasses. Judd-Ofelt parameters Ω{sub 2} (6.38 × 10{sup −20} cm{sup 2}), Ω{sub 4} (20.30 × 10{sup −20} cm{sup 2}) and Ω{sub 6} (0.40 × 10{sup −20} cm{sup 2}) indicate a high inversion asymmetrical and strong covalent environment in the optical glasses. The effective bandwidth (Δλ{sub eff}) of the corresponding {sup 1}D{sub 2} → {sup 1}G{sub 4} transition emission is obtained to be 124 nm, and the maximum stimulated emission cross-section (σ{sub em-max}) at 1468 nm is derived to be 1.14 × 10{sup −20} cm{sup 2}. Channel waveguide was fabricated successfully by K{sup +}-Na{sup +} ion-exchange method with mode field diameter of 8.8 μm in the horizontal direction and 6.7 μm in the vertical direction. Broad effective bandwidth, large emission cross-section and perfect thermal ion-exchangeability indicate that Pr{sup 3+}-doped NMAP phosphate glasses are promising in developing integrated broadband waveguide amplifier, especially operating at E- and S-bands which belong to the fifth optical telecommunication window.

  6. The superspin glass transition in zinc ferrite nanoparticles

    Czech Academy of Sciences Publication Activity Database

    Kaman, Ondřej; Kořínková, T.; Jirák, T.; Maryško, Miroslav; Veverka, Miroslav

    2015-01-01

    Roč. 117, č. 17 (2015), "17C706-1"-"17C706-4" ISSN 0021-8979 R&D Projects: GA ČR(CZ) GAP108/11/0807; GA ČR GAP204/10/0035 Institutional support: RVO:68378271 Keywords : superspin glass * zinc ferrite * doped magnetite * magnetic nanoparticles * thermal decomposition Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.101, year: 2015

  7. On the mechanism of ion exchange in zirconium phosphates

    International Nuclear Information System (INIS)

    Clearfield, A.; Kalnins, J.M.

    1978-01-01

    The exchange of transition metal (M 2+ ) ions from manganese through cobalt, nickel, copper to zinc with γ-zirconium phosphate was examined. By using acetate salts the hydrogen ion concentration is kept low enough to achieve high loadings. The fully loaded solids have the composition ZrM(PO 4 ) 2 .4H 2 O. Near quantitative uptakes are achieved at 100 0 C. The interlayer spacings change very little with loading indicating that γ-zirconium phosphate is able to accommodate cations and water molecules without appreciable increase in volume. The copper exchanged phase readily forms an acetylacetonate when shaken with 2,4-pentanedione. (author)

  8. Spectroscopic identification of rare earth elements in phosphate glass

    Science.gov (United States)

    Devangad, Praveen; Tamboli, Maktum; Muhammed Shameem, K. M.; Nayak, Rajesh; Patil, Ajeetkumar; Unnikrishnan, V. K.; Santhosh, C.; Kumar, G. A.

    2018-01-01

    In this work, rare earth-doped phosphate glasses were synthesized and characterized using three different spectroscopic techniques. The absorption spectra of the prepared praseodymium (Pr) and samarium (Sm) doped glasses, recorded by a UV-VIS-NIR spectrophotometer, show the characteristic absorption bands of these elements. To confirm this inference, laser-induced fluorescence spectra of Pr and Sm were obtained at a laser excitation of 442 nm. Their emission bands are reported here. The elemental analysis of these samples was carried out using a laser-induced breakdown spectroscopy (LIBS) system. Characteristic emission lines of Pr and Sm have been identified and reported by the recorded LIBS spectra of glass samples. Results prove that using these three complimentary spectroscopic techniques (absorption, fluorescence and LIBS), we can meaningfully characterize rare earth-doped glass samples.

  9. In vitro study of nano-sized zinc doped bioactive glass

    Energy Technology Data Exchange (ETDEWEB)

    Goh, Yi-Fan; Alshemary, Ammar Z.; Akram, Muhammad [Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM skudai, Johor Darul Ta' zim (Malaysia); Abdul Kadir, Mohammed Rafiq [Medical Implant Technology Group, Faculty of Biomedical Engineering and Health Science, Universiti Teknologi Malaysia, 81310 UTMJohor Bahru (Malaysia); Hussain, Rafaqat, E-mail: rafaqat@kimia.fs.utm.my [IbnuSina Institute for Fundamental Science Studies, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor DarulTa' zim (Malaysia)

    2013-01-15

    Surface reactivity in physiological fluid has been linked to bioactivity of a material. Past research has shown that bioactive glass containing zinc has the potential in bone regeneration field due to its enhanced bioactivity. However, results from literature are always contradictory. Therefore, in this study, surface reactivity of bioactive glass containing zinc was evaluated through the study of morphology and composition of apatite layer formed after immersion in simulated body fluid (SBF). Nano-sized bioactive glass with 5 and 10 mol% zinc were synthesized through quick alkali sol-gel method. The synthesized Zn-bioglass was characterized using field emission scanning electron microscope (FESEM), energy dispersive X-ray spectrometer (EDX), X-ray diffractometer (XRD) and Fourier transform infrared spectrometer (FTIR). Samples after SBF immersion were characterized using scanning electron microscope (SEM) and EDX. Morphological study through SEM showed the formation of spherical apatite particles with Ca/P ratio closer to 1.67 on the surface of 5 mol% Zn-bioglass. Whereas, the 10 mol% Zn-bioglass samples induced the formation of flake-like structure of calcite in addition to the spherical apatite particles with much higher Ca/P ratio. Our results suggest that the higher Zn content increases the bioactivity through the formation of bone-bonding calcite as well as the spherical apatite particles. -- Highlights: Black-Right-Pointing-Pointer Nano-sized bioactive glasses were synthesized through quick alkali sol-gel method. Black-Right-Pointing-Pointer 5 and 10 mol% Zn-bioglass induced the formation of spherical particles in SBF test. Black-Right-Pointing-Pointer 10 mol% Zn-bioglass also induced the formation of flake-like structure. Black-Right-Pointing-Pointer The flake-like structure is calcium carbonate; spherical particles are apatite. Black-Right-Pointing-Pointer High Zn contents negatively influence the chemical composition of the apatite layer.

  10. Effects of the zinc and zinc-nickel alloys electroplating on the corrodibility of reinforced concrete rebars

    Directory of Open Access Journals (Sweden)

    F. A. CEDRIM

    Full Text Available Abstract This paper shows the analysis performed on the corrosion parameters of three groups of reinforcing steel bars, two of these coated by electroplating process with Zinc (Zn and Zinc-Nickel (Zn-Ni, and the other without any coating. It was used reinforced concrete specimens, which ones were grouped and then subjected to two different corrosion accelerating methods: aging wetting/drying cycles and salt spray exposure. Corrosion potential was measured to qualitative monitoring of the process and, after the end of the tests, corrosion rate was estimated by measuring the mass loss, to quantitative analyses. As it was expected, coated bars presented a better performance than the average bars regarding the corrosion resistance in chloride ions containing environments. It was also observed that the drying/ NaCl solution wetting cycles seems to be more severe than salt spray fog apparatus with respect to the acceleration of corrosion process.

  11. Optical and structural characterization of rare earth doped niobium phosphate glasses

    International Nuclear Information System (INIS)

    Sene, F.F.; Martinelli, J.R.; Gomes, L.

    2004-01-01

    Phosphate glasses containing up to 45mol% of niobium were obtained. X-ray diffraction, infrared, Raman, and optical absorption spectroscopy were used to analyze those materials. The refractive index varies from 1.70 to 1.85 as the amount of Nb increases. Niobium phosphate glasses with optical transparence in the (400-2500nm) range were produced. The cut off varied from 342nm to 378nm as a function of the Nb concentration. The cut off is due to the charge transfer O 2 ->Nb 5+ . Glasses containing 10mol% of Nb 2 O 5 are the most promising materials to be used as rare-earth ions hosts because they are chemically resistant, and show optical transparency in the spectral range of visible to infrared. Doping the glasses with 1-5mol% of Er, Ho, Pr, and Yb ions does not change the glass structure, as measured by X-ray diffraction, infrared, and Raman spectroscopy. The fluorescence lifetimes were determined for Nd, Yb, and Er, and the absorption cross-section were determined for all ions. The energy transfer in co-doped Yb-Er system was measured, and the lifetime of excited states and the luminescence efficiency were determined to be 91% for the Er 4 I 11/2 level, in the Yb-Er co-doped glasses

  12. Immobilization of {sup 99}Tc (Re) using Iron-Phosphate Glasses

    Energy Technology Data Exchange (ETDEWEB)

    Heo, Jong; Xu, Kai; Um, Woo Yong; Hrma, Pavel [Pohang Univ. of Science and Technology, Pohang (Korea, Republic of)

    2012-05-15

    Technetium-99 ({sup 99}Tc) is a fission product artificially generated during the irradiation of {sup 235}U for commercial power production or {sup 239}Pu for nuclear weapons. Under oxidizing conditions, the dominant species of Tc, the pertechnetate anion (TcO{sub 4} {sup -}), is highly soluble in ground water and thus easily transports through the geologic systems. In addition, because of its high fission yield ({approx}6 %) and long half-life (2.1x10{sup 5} yr), immobilization of {sup 99}Tc has been investigated for decades. Several waste forms such as metallic alloys, sintered titanate ceramics and chemically bonded phosphate ceramics have been proposed to encapsulate {sup 99}Tc. They have not yet been realized in the industrial-scale, mostly either due to the high volatilization of {sup 99}Tc during high temperature process (>1300 .deg. C), or the low {sup 99}Tc loading. Iron-phosphate (FeP) glasses have been developed as alternative waste forms because of their chemical durability equivalent to borosilicate glasses. Additionally, vitrification of radioactive waste by FeP glasses can be done at a relatively low temperature ({approx}1000 .deg. C) and the low-temperature process can reduce the volatilization of {sup 99}Tc significantly. Thus, this work reports the immobilization of {sup 99}Tc by FeP glasses using rhenium (Re) as a surrogate. We also examine the chemical durability of Re-containing FeP glasses using product consistency test (PCT). Experimental results reveal that FeP glass can become a promising candidate for immobilizing {sup 99}Tc

  13. Red light emission from europium doped zinc sodium bismuth borate glasses

    Science.gov (United States)

    Hegde, Vinod; Viswanath, C. S. Dwaraka; Upadhyaya, Vyasa; Mahato, K. K.; Kamath, Sudha D.

    2017-12-01

    Zinc sodium bismuth borate (ZNBB) glasses doped with different concentrations of europium were prepared by conventional melt quenching method and characterized through the measurements of density, refractive index, X-ray diffraction (XRD), Fourier Transform Infrared (FTIR) spectra, optical absorption, luminescence and radiative lifetimes. FTIR spectra showed seven characteristic peaks of bismuth and borate functional groups in the range of 400-1600 cm-1. The optical band gap and bonding parameters have been calculated from absorption spectra. Photoluminescence spectra recorded in the visible region with 394 nm excitation are used to calculate the Judd-Ofelt (JO) intensity parameters (Ω2 and Ω4). The JO intensity parameters have been used to calculate the radiative parameters such as branching ratio (β), stimulated emission cross-section (σse), transition probability (A) for the fluorescent level of 5D0→7F2. Decay rates through single exponential are used to calculate the lifetime (τm) of the meta-stable state 5D0 of (Eu3+ ion) these glasses. The radiative parameters measured for all these glasses show 0.7 mol% europium doped zinc sodium bismuth borate glass 5D0→7F2 transition has the potential for red laser applications. The quality of the colour emitted by the present glasses are estimated quantitatively by CIE chromaticity coordinates, which confirms the suitability of these glasses as a red emitting material for field emission technologies and LEDs.

  14. Sol-Gel Synthesis of Phosphate-Based Glasses for Hydrophilic Enamel Applications

    International Nuclear Information System (INIS)

    Kim, Dae-Sung; Ryu, Bong-ki

    2017-01-01

    In this study, quaternary phosphate-based sol-gel derived glasses were synthesized from a P 2 O 5 -CaO-Na 2 O-TiO 2 system with a high TiO 2 content of up to 50 mol%. The sol-gel method was chosen because incorporating a high percentage of titanium into a phosphate network via traditional melt-quench methods is non-trivial. The structure and thermal properties of the obtained stabilized sol-gel glasses were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and differential scanning calorimetry (DSC). The XRD results confirmed the amorphous nature of all of the stabilized sol–gel derived glasses. The FTIR results revealed that added TiO 2 enters the network as (TiO 6 ), which likely acts as a modifier oxide. Consequently, the number of terminal oxygen atoms increases, leading to an increase in the number of P-OH bonds. In addition, DSC results confirmed a decrease in glass transition and crystallization temperatures with increasing TiO 2 content. This is the first report of a sol-gel synthesis strategy combined with enameling to prepare glass at low processing temperatures and the first use of such a system for both hydrophilic and chemical resistance purposes.

  15. Sol-Gel Synthesis of Phosphate-Based Glasses for Hydrophilic Enamel Applications

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dae-Sung; Ryu, Bong-ki [Pusan National University, Busan (Korea, Republic of)

    2017-04-15

    In this study, quaternary phosphate-based sol-gel derived glasses were synthesized from a P{sub 2}O{sub 5}-CaO-Na{sub 2}O-TiO{sub 2} system with a high TiO{sub 2} content of up to 50 mol%. The sol-gel method was chosen because incorporating a high percentage of titanium into a phosphate network via traditional melt-quench methods is non-trivial. The structure and thermal properties of the obtained stabilized sol-gel glasses were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and differential scanning calorimetry (DSC). The XRD results confirmed the amorphous nature of all of the stabilized sol–gel derived glasses. The FTIR results revealed that added TiO{sub 2} enters the network as (TiO{sub 6}), which likely acts as a modifier oxide. Consequently, the number of terminal oxygen atoms increases, leading to an increase in the number of P-OH bonds. In addition, DSC results confirmed a decrease in glass transition and crystallization temperatures with increasing TiO{sub 2} content. This is the first report of a sol-gel synthesis strategy combined with enameling to prepare glass at low processing temperatures and the first use of such a system for both hydrophilic and chemical resistance purposes.

  16. Immobilisation of radio cesium loaded ammonium molybdo phosphate in glass matrices

    International Nuclear Information System (INIS)

    Yalmali, Vrunda S.; Singh, I.J.; Sathi Sasidharan, N.; Deshingkar, D.S.

    2004-11-01

    Long half life and easy availability from high level wastes make 137 Cesium most economical radiation source. High level liquid waste processing for 137 Cesium removal has become easier due to development of Cesium specific granulated ammonium molybdophosphate (AMP) composite. In such applications, resulting spent composite AMP itself represents high active solid waste and immobilization of these materials in cement may not be acceptable. Studies on immobilization of 137 Cs loaded AMP were taken up in order to achieve twin goals of increasing safety and minimizing processing costs of the final matrix. Studies indicated that phosphate modified sodium borosilicate SPNM glasses prepared under usual oxidizing conditions are not suitable for immobilization of 137 Cs loaded on AMP .Phosphate glasses containing Na 2 O, P 2 O 5 , B 2 O 3 , Fe 2 O 3 , Al 2 O 3 and SiO 2 as major constituents are capable of incorporating 6 to 8 % AMP. The Normalized Leach rates of these glasses for sodium, cesium, boron and silica are 10 -4 to 10 -6 gm/cm 2 /day which are comparable to or better than those reported for NBS glasses incorporating HLW. Homogeneity of the final matrix was confirmed by x-ray diffraction analysis. Further studies on characterization of these glasses would establish their acceptability. (author)

  17. Synthesis, characterisation and anion exchange properties of copper, magnesium, zinc and nickel hydroxy nitrates

    Science.gov (United States)

    Biswick, Timothy; Jones, William; Pacuła, Aleksandra; Serwicka, Ewa

    2006-01-01

    Anion exchange reactions of four structurally related hydroxy salts, Cu 2(OH) 3NO 3, Mg 2(OH) 3NO 3, Ni 2(OH) 3NO 3 and Zn 3(OH) 4(NO 3) 2 are compared and trends rationalised in terms of the strength of the covalent bond between the nitrate group and the matrix cation. Powder X-ray diffraction (PXRD), Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA) and elemental analysis are used to characterise the materials. Replacement of the nitrate anions in the zinc and copper salts with benzoate anions is possible although exchange of the zinc salt is accompanied by modification of the layer structure from one where zinc is exclusively six-fold coordinated to a structure where there is both six- and four-fold zinc coordination. Magnesium and nickel hydroxy nitrates, on the other hand, hydrolyse to their respective metal hydroxides.

  18. Effect of soluble zinc additions on the SCC performance of nickel alloys in deaerated hydrogenated water

    International Nuclear Information System (INIS)

    Morton, D.S.; Thompson, C.D.; Gladding, D.; Schurman, M.K.

    1997-08-01

    Stress corrosion crack growth rates (SCCGR) of alloy 600, EN82H and X-750 were measured in deaerated hydrogenated water to determine if soluble zinc mitigates SCCGR. Constant load compact tension specimen tests were conducted. Two test strategies were used to discern a possible zinc effect. The first strategy employed separate SCCGR tests in zinc and non-zinc environments and compared the resulting crack growth rates. The second strategy varied zinc levels at the midterm of single specimen SCCGR tests and characterized the resulting crack growth rate effect through an electrical potential drop in-situ crack monitor. Results from the direct comparison and midterm changing chemistry tests did not discern a zinc influence; any apparent zinc influence is within test to test variability (∼1.5x change in crack growth rate). AEM, AUGER and ESCA crack tip fracture surface studies identified that zinc was not incorporated within crack tip oxides. These studies identified nickel rich crack tip oxides and spinel, with incorporated zinc, (∼5 atom percent) bulk surface oxides

  19. Phosphate-based glass fiber vs. bulk glass: Change in fiber optical response to probe in vitro glass reactivity.

    Science.gov (United States)

    Massera, J; Ahmed, I; Petit, L; Aallos, V; Hupa, L

    2014-04-01

    This paper investigates the effect of fiber drawing on the thermal and structural properties as well as on the glass reactivity of a phosphate glass in tris(hydroxymethyl)aminomethane-buffered (TRIS) solution and simulated body fluid (SBF). The changes induced in the thermal properties suggest that the fiber drawing process leads to a weakening and probable re-orientation of the POP bonds. Whereas the fiber drawing did not significantly impact the release of P and Ca, an increase in the release of Na into the solution was noticed. This was probably due to small structural reorientations occurring during the fiber drawing process and to a slight diffusion of Na to the fiber surface. Both the powders from the bulk and the glass fibers formed a Ca-P surface layer when immersed in SBF and TRIS. The layer thickness was higher in the calcium and phosphate supersaturated SBF than in TRIS. This paper for the first time presents the in vitro reactivity and optical response of a phosphate-based bioactive glass (PBG) fiber when immersed in SBF. The light intensity remained constant for the first 48h after which a decrease with three distinct slopes was observed: the first decrease between 48 and 200h of immersion could be correlated to the formation of the Ca-P layer at the fiber surface. After this a faster decrease in light transmission was observed from 200 to ~425h in SBF. SEM analysis suggested that after 200h, the surface of the fiber was fully covered by a thin Ca-P layer which is likely to scatter light. For immersion times longer than ~425h, the thickness of the Ca-P layer increased and thus acted as a barrier to the dissolution process limiting further reduction in light transmission. The tracking of light transmission through the PBG fiber allowed monitoring of the fiber dissolution in vitro. These results are essential in developing new bioactive fiber sensors that can be used to monitor bioresponse in situ. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. The peculiarity of the formation of zinc films on a glass substrate

    Energy Technology Data Exchange (ETDEWEB)

    Tomaev, V. V., E-mail: tvaza@mail.ru [Saint Petersburg State University, 198504, Russia, Saint-Petersburg, Petrodvorets, Universitetskii pr. 26 (Russian Federation); Saint Petersburg Mining University, Russia, 199106, St. Petersburg, V.O., 21-st line, 2 (Russian Federation); Polishchuk, V. A., E-mail: vpvova2010@yandex.ru [St. Petersburg University of Information Technologies, Mechanics, and Optics, 197101, Russia, St. Petersburg, Kronverksky Pr., 49 (Russian Federation); Borisov, E. N., E-mail: enbor@bk.ru [Saint Petersburg State University, 198504, Russia, Saint-Petersburg, Petrodvorets, Universitetskii pr. 26 (Russian Federation)

    2016-06-17

    Thin Nanocrystalline films of the zinc have been fabricated by thermal spraying on the glass substrate. Morphologies and structure of the films had been investigated by the methods X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). It is found that the surface of the films has a different types of the nanocrystals zinc. Were detected intergrowths of two or more the nanocrystals, hexagonal shape. Using the theory of homogeneous and heterogeneous nucleation of a new phase, had been evaluated the geometrical and thermodynamic parameters nanocrystals zinc.

  1. Recent advances in phosphate laser glasses for high power applications

    International Nuclear Information System (INIS)

    Campbell, J.H.

    1996-01-01

    Recent advances in Nd-doped phosphate laser glasses for high-peak-power and high-average-power applications are reviewed. Compositional studies have progressed to the point that glasses can be tailored to have specific properties for specific applications. Non-radiative relaxation effects can be accurately modeled and empirical expressions have been developed to evaluate both intrinsic (structural) and extrinsic (contamination induced) relaxation effects. Losses due to surface scattering and bulk glass absorption have been carefully measured and can be accurately predicted. Improvements in processing have lead to high damage threshold (e.g. Pt inclusion free) and high thermal shock resistant glasses with improved edge claddings. High optical quality pieces up to 79 x 45 x 4cm 3 have been made and methods for continuous melting laser glass are under development

  2. Thermodynamic Study of the Nickel Addition in Zinc Hot-Dip Galvanizing Baths

    Science.gov (United States)

    Pistofidis, N.; Vourlias, G.

    2010-01-01

    A usual practice during zinc hot-dip galvanizing is the addition of nickel in the liquid zinc which is used to inhibit the Sandelin effect. Its action is due to the fact that the ζ (zeta) phase of the Fe-Zn system is replaced by the Τ (tau) phase of the Fe-Zn-Ni system. In the present work an attempt is made to explain the formation of the Τ phase with thermodynamics. For this reason the Gibbs free energy changes for Τ and ζ phases were calculated. The excess free energy for the system was calculated with the Redlich-Kister polyonyme. From this calculation it was deduced that the Gibbs energy change for the tau phase is negative. As a result its formation is spontaneous.

  3. Optimization of microwave assisted digestion procedure for the determination of zinc, copper and nickel in tea samples employing flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Soylak, Mustafa; Tuzen, Mustafa; Souza, Anderson Santos; Korn, Maria das Gracas Andrade; Ferreira, Sergio Luis Costa

    2007-01-01

    The present paper describes the development of a microwave assisted digestion procedure for the determination of zinc, copper and nickel in tea samples employing flame atomic absorption spectrometry (FAAS). The optimization step was performed using a full factorial design (2 3 ) involving the factors: composition of the acid mixture (CMA), microwave power (MP) and radiation time (RT). The experiments of this factorial were carried out using a certified reference material of tea GBW 07605 furnished by National Research Centre for Certified Reference Materials, China, being the metal recoveries considered as response. The relative standard deviations of the method were found below 8% for the three elements. The procedure proposed was used for the determination of copper, zinc and nickel in several samples of tea from Turkey. For 10 tea samples analyzed, the concentration achieved for copper, zinc and nickel varied at 6.4-13.1, 7.0-16.5 and 3.1-5.7 (μg g -1 ), respectively

  4. Phosphates nanoparticles doped with zinc and manganese for sunscreens

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, T.S. de, E-mail: tatiana.araujo@ifs.edu.br [Departamento de Fisica, Universidade Federal de Sergipe, Sergipe (Brazil); Instituto Federal de Ciencias e Tecnologia de Sergipe, Sergipe (Brazil); Souza, S.O. de [Departamento de Fisica, Universidade Federal de Sergipe, Sergipe (Brazil); Miyakawa, W. [Divisao de Fotonica - Instituto de Estudos Avancados, Sao Jose dos Campos (Brazil); Sousa, E.M.B. de [Centro de Desenvolvimento de Tecnologia Nuclear - CDTN/CNEN, Minas Gerais (Brazil)

    2010-12-01

    The crescent number of skin cancer worldwide gives impulse to the development of sunscreen that can both prevent skin cancer and also permit gradual tanning. In this work, the synthesis of hydroxyapatite and tricalcium phosphate nanocrystalline powders was investigated in order to obtain materials with optical properties and appropriate size for sunscreen. Pure, Zn{sup 2+}-doped and Mn{sup 2+}-doped hydroxyapatite (HAP) and tricalcium phosphate ({beta}-TCP) were produced by the wet precipitation process using diammonium phosphate, calcium nitrate, ammonium hydroxide, zinc nitrate and manganese nitrate as reagents. The pure and doped HAP precipitates were calcined at 500 deg. C for 1 h, while the {beta}-TCP (pure and doped) were calcined at 800 deg. C for 2 h. The powder samples were characterized by X-ray diffraction (XRD), energy dispersive X-ray fluorescence (EDX), atomic force microscopy (AFM) and ultraviolet (UV)-vis spectroscopy. XRD and EDX showed the formation of the expected materials (HAP and {beta}-TCP) without toxic components. AFM micrographs showed aggregated ellipsoidal particles with dimensions smaller than 120 nm. Optical absorption spectra showed that the calcium phosphate produced in this work absorbs in the UV region. The obtained materials presented structural, morphological and optical properties that allow their use as the active centers in sunscreens.

  5. Phosphates nanoparticles doped with zinc and manganese for sunscreens

    International Nuclear Information System (INIS)

    Araujo, T.S. de; Souza, S.O. de; Miyakawa, W.; Sousa, E.M.B. de

    2010-01-01

    The crescent number of skin cancer worldwide gives impulse to the development of sunscreen that can both prevent skin cancer and also permit gradual tanning. In this work, the synthesis of hydroxyapatite and tricalcium phosphate nanocrystalline powders was investigated in order to obtain materials with optical properties and appropriate size for sunscreen. Pure, Zn 2+ -doped and Mn 2+ -doped hydroxyapatite (HAP) and tricalcium phosphate (β-TCP) were produced by the wet precipitation process using diammonium phosphate, calcium nitrate, ammonium hydroxide, zinc nitrate and manganese nitrate as reagents. The pure and doped HAP precipitates were calcined at 500 deg. C for 1 h, while the β-TCP (pure and doped) were calcined at 800 deg. C for 2 h. The powder samples were characterized by X-ray diffraction (XRD), energy dispersive X-ray fluorescence (EDX), atomic force microscopy (AFM) and ultraviolet (UV)-vis spectroscopy. XRD and EDX showed the formation of the expected materials (HAP and β-TCP) without toxic components. AFM micrographs showed aggregated ellipsoidal particles with dimensions smaller than 120 nm. Optical absorption spectra showed that the calcium phosphate produced in this work absorbs in the UV region. The obtained materials presented structural, morphological and optical properties that allow their use as the active centers in sunscreens.

  6. Enhanced Luminescent Properties in Tm3+/Dy3+ Co-doped Transparent Phosphate Glass Ceramic

    OpenAIRE

    Yao L. Q.; Chen G. H.; Zhong H. J.; Cui S. C.; Li F.; Gan J.Y.

    2016-01-01

    Novel Tm3+/Dy3+ co-doped phosphate glass and glass ceramic samples for white light emitting diodes were prepared by melt quenching method. Under 353 nm excitation, the colors of the luminescence of the glass and glass ceramic samples are white. The CIE chromaticity coordinates (0.338, 0.328) of the emission from the glass ceramic is close to the standard white-light illumination (0.333, 0.333). Compared to the glass, the fluorescence intensity in the glass ceramic is greatly enhanced.

  7. The effects of element Cu on the electrochemical performances of Zinc-Aluminum-hydrotalcites in Zinc/Nickel secondary battery

    International Nuclear Information System (INIS)

    Wen, Xing; Yang, Zhanhong; Xie, Xiaoe; Feng, Zhaobin; Huang, Jianhang

    2015-01-01

    Zn-Cu-Al-CO_3 layered double hydroxides (LDHs) have been successfully synthesized by using the method of constant pH co-precipitation. And it also has been proposed as a novel anodic material in Zinc-Nickel secondary batteries. The X-ray diffraction (XRD) patterns and scanning electron microscopy (SEM) images of the as-prepared sample exhibit that the samples are well crystallized and have hexagon structure. The electrochemical performances of Zn-Al-LDHs and Zn-Cu-Al-LDHs with different Zn/Cu/Al molar ratios are investigated by the measurements such as galvanostatic charge-discharge, cyclic voltammogram and electrochemical impedance spectroscopy (EIS). Comparing with the pure Zn-Al-LDHs, Zn-Cu-Al-LDHs show more stable cycling performance, exhibit better reversibility and display lower charge-transfer resistance. Especially, the Zn-Cu-Al-LDHs with the Zn/Cu/Al molar ratio being 2.8:0.2:1 exhibits the best electrochemical properties than other samples. After 800 cell cycles, the specific discharge capacity of Zn-Cu-Al-LDHs with the Zn/Cu/Al molar ratio of 2.8:0.2:1is 345 mA h g"−"1, while that of pure Zn-Al-LDHs is only 177 mA h g"−"1. Based on these observations, the prepared Zn-Cu-Al-LDHs may be a promising anode active material for Zinc/Nickel secondary batteries.

  8. Structural and spectroscopic characteristics of Eu3+-doped tungsten phosphate glasses

    Science.gov (United States)

    Dousti, M. Reza; Poirier, Gael Yves; de Camargo, Andrea Simone Stucchi

    2015-07-01

    Tungsten based phosphate glasses are interesting non-crystalline materials, commonly known for photochromic and electrochromic effects, but also promising hosts for luminescent trivalent rare earth ions. Despite very few reports in the literature, association of the host´s functionalities with the efficient emissions of the dopant ions in the visible and near-infrared spectra could lead to novel applications. This work reports the preparation and characterization of glasses with the new composition 4(Sb2O3)96-x(50WO3 50NaPO3)xEu2O3 where x = 0, 0.1, 0.25, 0.5 and 1.0 mol%, obtained by the melt quenching technique. The glasses present large density (∼4.6 g cm-3), high glass transition temperature (∼480 °C) and high thermal stability against crystallization. Upon excitation at 464 nm, the characteristic emissions of Eu3+ ions in the red spectral region are observed with high intensity. The Judd-Ofelt intensity parameters Ω2 = 6.86 × 10-20, Ω4 = 3.22 × 10-20 and Ω6 = 8.2 × 10-20 cm2 were calculated from the emission spectra and found to be higher than those reported for other phosphate glass compositions. An average excited state lifetime value of 1.2 ms, was determined by fitting the luminescence decay curves with single exponential functions and it is comparable or higher than those of other oxide glasses.

  9. Research, development, and demonstration of nickel-zinc batteries for electric-vehicle propulsion. Annual report for 1980

    Energy Technology Data Exchange (ETDEWEB)

    1981-03-01

    Progress in work at Exide in three main development areas, i.e., battery design and development, nickel cathode study, and electrochemical studies is reported. Battery design and development concentrated on the optimization of design parameters, including electrode spacing, charging methods, electrolyte concentration, the design and fabrication of prototype cells and modules, and testing to verify these parameters. Initial experiments indicated that an interelectrode spacing of 2.5 mm was optimum when normal (D.C.) charging is used. It was during these experiments that a high rate charging technique was developed to deposit a dense active zinc which did not shed during vibration. A 4 cell - 300 Ah experimental module was built and sent to NBTL for testing. Initial testing on this module and a 300 Ah cell are reported. Experiments on electrolyte concentration indicate that higher concentrations of KOH (8M, 9M or 10M) are beneficial to capacity maintenance. Available nickel cathodes were evaluated for possible use in the VIBROCEL. These included pocket, sintered plaque impregnated, nickel plated steel wool impregnated, plastic bonded and CMG (multifoil) electrodes. These electrodes have Coulombic densities ranging from 70 Ah/Kg for pocket plates to 190 Ah/Kg for CMG electrodes. Detailed test data are presented for each type including rate capability, effect of zincate on performance, and capacity maintenance with cycling. Work on zinc deposition emphasized the special charging technique. This is a deposition using special waveforms of charging current, to deposit dense crystalline zinc on the anode substrate.

  10. Comprehensive thermal and structural characterization of antimony-phosphate glass

    Science.gov (United States)

    Moustafa, S. Y.; Sahar, M. R.; Ghoshal, S. K.

    For the first time, we prepare new ternary glass systems of composition (95-x)Sb2O3-xP2O5-5MgO, where x = 45, 40, 35 mol%; (85-x)Sb2O3-xP2O5-15MgO, where x = 55, 35, 25 mol%; (75-x)Sb2O3-xP2O5-25MgO, where x = 45, 35, 25 mol%; and 60Sb2O3-(40-x)P2O5-xMgO, where x = 10, 20 mol% via melt-quenching method. Synthesized glasses are characterized using XRD, FESEM, EDX, and TG/DTA measurements. The influence of varying modifier concentrations on their thermal properties is evaluated. The XRD patterns confirmed the amorphous nature of samples. SEM images demonstrated interesting phase formation with ribbons-like texture. Five crystalline phases are evidenced in the ternary diagram which are antimony phosphate and antimony orthophosphate as major phases as well as magnesium phosphate, magnesium cyclo-tetraphosphate and cervantite as minor phases. EDX spectra detected the right elemental traces. Detailed thermal analysis of these glasses revealed their high-molecular polymer character for Sb2O3 content greater than 50 mol%. Three different glass transition temperatures are achieved around 276, 380-381 and 422-470 °C depending on the composition. Furthermore, the solidus and liquidus temperature are found to decrease with increasing Sb2O3 and increases for MgO contents till 15 mol% and then decrease, where the lowest recorded solidus temperature is 426 °C. This observation may open up new research avenues for antimony based ternary glasses and an exploitation of the derived results for optoelectronics applications, photonic devices and non-linear optical devices.

  11. Mechanisms of postradiation transformations in alkaline-phosphate glasses activated by copper

    International Nuclear Information System (INIS)

    Vil'chinskaya, N.N.; Dmitryuk, A.V.; Ignat'ev, E.G.; Karapetyan, G.O.; Petrovskij, G.T.

    1984-01-01

    Lithium aluminophosphate glasses activated by copper served as the object under investigation. Copper content varied from 0 up to 0.13 mass.%. It is shown that pole redistribution among PO 4 2- and Cu(2) centers takes place in alkaline -phosphate glasses activated by Cu(1). This process prevails for copper content of above 0.1%. Therefore the possibility appears to evaluate the quantum yield of colour center formation

  12. Mechanisms of postradiation transformations in alkaline-phosphate glasses activated by copper

    Energy Technology Data Exchange (ETDEWEB)

    Vil' chinskaya, N.N.; Dmitryuk, A.V.; Ignat' ev, E.G.; Karapetyan, G.O.; Petrovskij, G.T. (Gosudarstvennyj Opticheskij Inst., Leningrad (USSR))

    1984-01-01

    Lithium aluminophosphate glasses activated by copper served as the object under investigation. Copper content varied from 0 up to 0.13 mass.%. It is shown that pole redistribution among PO/sub 4//sup 2 -/ and Cu(2) centers takes place in alkaline -phosphate glasses activated by Cu(1). This process prevails for copper content of above 0.1%. Therefore the possibility appears to evaluate the quantum yield of colour center formation.

  13. Experimental Investigation of the Electro Co-deposition of (Zinc-Nickel Alloy

    Directory of Open Access Journals (Sweden)

    Ekhlas Abdulrahman Salman

    2018-02-01

    Full Text Available abstract An experimental investigation has been carried out for zinc-nickel (Zn-Ni electro-deposition using the constant applied current technique. Weight difference approach method was used to determine the cathode current efficiency and deposit thickness. Also, the influence effect of current density on the deposition process, solderability, and porosity of the plating layer in microelectronic applications were examined. The bath temperature effect on nickel composition and the form of the contract was studied using Scanning Electron Microscope (SEM. Moreover, elemental nature of the deposition was analyzed by Energy Dispersive X-Ray (EDX. It has been found that the best bath temperature was 40˚C, specifically at a concentration of 73 g/L of NiCl2.6H2O, has a milestone influence on the nickel composition and structure of the deposits. The potential is a major factor influencing the deposition coating alloy which is adjusted by the operations of the cathodic polarization; rather than the standard potential of the two metals as determined by the e.m.f. series. The anomalous deposition was obtained at a current density lower than 0.8 A/dm2, while normal deposition occurred at current densities less than 1.2 A/dm2. Corrosion behavior was exhibited by the bath and for performance was carried out, and it shows that the best corrosion performance was for nickel composition of 10-12.6 wt%.

  14. Comparative investigation on the spectroscopic properties of Pr³⁺-doped boro-phosphate, boro-germo-silicate and tellurite glasses.

    Science.gov (United States)

    Zhang, Liaolin; Dong, Guoping; Peng, Mingying; Qiu, Jianrong

    2012-07-01

    We report on the spectroscopic properties of Pr(3+)-doped boro-phosphate, boro-germo-silicate and tellurite glasses. The stimulated absorption and emission cross sections were estimated. Only one emission at 596 nm and 605 nm is observed in Pr(3+)-doped boro-phosphate and boro-germo-silicate glasses, respectively, while three emissions at 605 nm, 612 nm and 645 nm are observed in Pr(3+)-doped tellurite glass when excited at 467 nm. The fluorescence lifetime at 600 nm in Pr(3+)-doped boro-phosphate, boro-germo-silicate and tellurite glasses is 137 μs, 73 μs and 51 μs, respectively. The emissions from Pr(3+)-doped boro-phosphate, boro-germo-silicate and tellurite glasses show different decay behaviors and can be well explained by multiphonon relaxation theory. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. Effects of Nanodiamond Abrasive Friability in Experimental MR Fluids with Phosphate Laser Glass LHG-8 and Other Optical Glasses

    Energy Technology Data Exchange (ETDEWEB)

    DeGroote, J.E.; Marino, A.E.; Wilson, J.P.; Spencer, K.E.; Jacobs, S.D.

    2005-09-22

    Research is currently being conducted to better understand the role that nanodiamond abrasives play in the removal process of Magnetorheological Finishing (MRF). The following presents removal rate data for a set of six optical glasses that were spotted (not polished out) with four different MR fluids, as well as texturing/smoothing data for phosphate laser glass LHG-8.

  16. Phosphate-based glasses: Prediction of acoustical properties

    Science.gov (United States)

    El-Moneim, Amin Abd

    2016-04-01

    In this work, a comprehensive study has been carried out to predict the composition dependence of bulk modulus and ultrasonic attenuation coefficient in the phosphate-based glass systems PbO-P2O5, Li2O-TeO2-B2O3-P2O5, TiO2-Na2O-CaO-P2O5 and Cr2O3-doped Na2O-ZnO-P2O5 at room temperature. The prediction is based on (i) Makishima-Mackenzie theory, which correlates the bulk modulus with packing density and dissociation energy per unit volume, and (ii) Our recently presented semi-empirical formulas, which correlate the ultrasonic attenuation coefficient with the oxygen density, mean atomic ring size, first-order stretching force constant and experimental bulk modulus. Results revealed that our recently presented semi-empirical formulas can be applied successfully to predict changes of ultrasonic attenuation coefficient in binary PbO-P2O5 glasses at 10 MHz frequency and in quaternary Li2O-TeO2-B2O3-P2O5, TiO2-Na2O-CaO-P2O5 and Cr2O3-Na2O-ZnO-P2O5 glasses at 5 MHz frequency. Also, Makishima-Mackenzie theory appears to be valid for the studied glasses if the effect of the basic structural units that present in the glass network is taken into account.

  17. Etude multi-échelle des mécanismes d'élaboration de revêtements d'alliage zinc-nickel à base d'électrolytes alcalins : germination, complexation et structures cristallines

    OpenAIRE

    Fedi , Baptiste

    2016-01-01

    The present work aims to deepen the understanding of the mechanisms of zinc-nickelelectrodeposition in alkaline baths. Zinc-nickel deposits containing between 12% and 16%nickel known for their anti-corrosion performance. Complexing agents are required toobtain soluble and reactive nickel forms, and to stabilize the electrolytes. A study ofthe complexing mechanisms has improved the understanding of their respective role andbehavior, and their influence on the stability and the morphology and c...

  18. Highly Doped Phosphate Glass Fibers for Compact Lasers and Amplifiers: A Review

    Directory of Open Access Journals (Sweden)

    Nadia Giovanna Boetti

    2017-12-01

    Full Text Available In recent years, the exploitation of compact laser sources and amplifiers in fiber form has found extensive applications in industrial and scientific fields. The fiber format offers compactness, high beam quality through single-mode regime and excellent heat dissipation, thus leading to high laser reliability and long-term stability. The realization of devices based on this technology requires an active medium with high optical gain over a short length to increase efficiency while mitigating nonlinear optical effects. Multicomponent phosphate glasses meet these requirements thanks to the high solubility of rare-earth ions in their glass matrix, alongside with high emission cross-sections, chemical stability and high optical damage threshold. In this paper, we review recent advances in the field thanks to the combination of highly-doped phosphate glasses and innovative fiber drawing techniques. We also present the main performance achievements and outlook both in continuous wave (CW and pulsed mode regimes.

  19. The antimicrobial activity of as-prepared silver-loaded phosphate glasses and zirconium phosphate

    International Nuclear Information System (INIS)

    Jing, Wang; Jiang, Ji Zhi; Yang, Yang; Yan, Zhao Chun; Yan, Wang Xiao; He, Shui Zhong

    2016-01-01

    The antimicrobial activities of silver-loaded zirconium phosphate (JDG) and silver-loaded phosphate glasses (ZZB) against Escherichia coli were studied. Although the silver content in JDG was higher than that in ZZB, ZZB suspensions showed better antimicrobial property than JDG suspensions, especially at low concentrations. The antimicrobial activity was analyzed using minimum inhibitory concentrations, bacterial inhibition ring tests, and detection of silver ions in the suspensions. Furthermore, the amounts of silver ions in suspensions with/without bacterial cells were analyzed. Results revealed that only a portion of released silver ions could be adsorbed by E. coli cells, which are critical to cell death. The damaged microstructures of E. coli cells observed by transmission electron microscopy may further prove that the adsorbed silver ions play an important role in the antimicrobial process.

  20. Structural characterization of hog iron oxide content glasses obtained from zinc hydrometallurgy wastes

    International Nuclear Information System (INIS)

    Romero, M.; Rincon, J.M.; Musik, S.; Kozhujharov, W.

    1997-01-01

    It has been carried out the structural characterization of high oxide content glasses obtained by melting of a goethite industrial waste from the zinc hydrometallurgy with other raw materials as dolomite and glass cullet. The structural characterization has been carried out by X-ray Diffraction (XRD), X-Ray Diffraction by Amorphous Dispersion (RDF) and Mossbauer spectroscopy. It has been determined the interatomic distance, the oxidation state and the coordination of iron atoms in these glasses. (Author) 16 refs

  1. Response of nickel to zinc cells to electric vehicle chopper discharge waveforms

    Science.gov (United States)

    Cataldo, R. L.

    1981-01-01

    The preliminary results of simulated electric vehicle chopper controlled discharge of a Nickel/Zinc battery shows delivered energy increases of 5 to 25 percent compared to constant current discharges of the same average current. The percentage increase was a function of chopper frequency, the ratio of peak to average current, and the magnitude of the discharge current. Because the chopper effects are of a complex nature, electric vehicle battery/speed controller interaction must be carefully considered in vehicle design to optimize battery performance.

  2. Evaluation of lead-iron-phosphate glass as a high-level waste form

    International Nuclear Information System (INIS)

    Chick, L.A.; Bunnell, L.R.; Strachan, D.M.; Kissinger, H.E.; Hodges, F.N.

    1986-01-01

    The lead-iron-phosphate (Pb-Fe-P) nuclear waste glass developed at Oak Ridge National Laboratory (ORNL) was evaluated for its potential as an improvement over the current reference waste form, borosilicate (B-Si) glass. Vitreous Pb-Fe-P glass appears to have substantially better chemical durability than B-Si glass. However, severe crystallization leading to deteriorated chemical durability would result if this glass were poured into large canisters, as is presently done with B-Si glass. Cesium leach rates from this crystallized material are orders of magnitude greater than those from B-Si glass. Therefore, to realize the performance advantages of the Pb-Fe-P material in a nuclear waste form, it would be necessary to process it so that it is cooled rapidly, thus retaining its vitreous structure

  3. Structure and properties of MoO.sub.3./sub.-containing zinc borophosphate glasses

    Czech Academy of Sciences Publication Activity Database

    Šubčík, J.; Koudelka, L.; Mošner, P.; Montagne, L.; Revel, B.; Gregora, Ivan

    2009-01-01

    Roč. 355, 16-17 (2009), 970-975 ISSN 0022-3093 R&D Projects: GA AV ČR KAN301370701 Institutional research plan: CEZ:AV0Z10100520 Keywords : glass formation * glass es * phosphates * structure Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.252, year: 2009

  4. Research, development, and demonstration of nickel-zinc batteries for electric vehicle propulsion. Annual report for 1980

    Energy Technology Data Exchange (ETDEWEB)

    1981-03-01

    Progress in developing nickel-zinc batteries for propelling electric vehicles is reported. Information is included on component design, battery fabrication, and module performance testing. Although full scale hardware performance has fallen short of the contract cycle life goals, significant progress has been made to warrant further development. (LCL)

  5. Cytotoxicity Comparison of Harvard Zinc Phosphate Cement Versus Panavia F2 and Rely X Plus Resin Cements on Rat L929-fibroblasts.

    Science.gov (United States)

    Mahasti, Sahabi; Sattari, Mandana; Romoozi, Elham; Akbar-Zadeh Baghban, Alireza

    2011-01-01

    Resin cements, regardless of their biocompatibility, have been widely used in restorative dentistry during the recent years. These cements contain hydroxy ethyl methacrylate (HEMA) molecules which are claimed to penetrate into dentinal tubules and may affect dental pulp. Since tooth preparation for metal ceramic restorations involves a large surface of the tooth, cytotoxicity of these cements would be more important in fixed prosthodontic treatments. The purpose of this study was to compare the cytotoxicity of two resin cements (Panavia F2 and Rely X Plus) versus zinc phosphate cement (Harvard) using rat L929-fibroblasts in vitro. In this experimental study, ninety hollow glass cylinders (internal diameter 5-mm, height 2-mm) were made and divided into three groups. Each group was filled with one of three experimental cements; Harvard Zinc Phosphate cement, Panavia F2 resin cement and Rely X Plus resin cement. L929- Fibroblast were passaged and subsequently cultured in 6-well plates of 5×10(5) cells each. The culture medium was RPMI_ 1640. All samples were incubated in CO2. Using enzyme-linked immune-sorbent assay (ELISA) and (3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) (MTT) assay, the cytotoxicity of the cements was investigated at 1 hour, 24 hours and one week post exposure. Statistical analyses were performed via two-way ANOVA and honestly significant difference (HSD) Tukey tests. This study revealed significant differences between the three cements at the different time intervals. Harvard cement displayed the greatest cytotoxicity at all three intervals. After 1 hour Panavia F2 showed the next greatest cytotoxicity, but after 24-hours and oneweek intervals Rely X Plus showed the next greatest cytotoxicity. The results further showed that cytotoxicity decreased significantly in the Panavia F2 group with time (pHarvard cement group failed to showed no noticeable change in cytotoxicity with time. Although this study has limitations, it provides

  6. Properties and solubility of chrome in iron alumina phosphate glasses containing high level nuclear waste

    International Nuclear Information System (INIS)

    Huang, W.; Day, D.E.; Ray, C.S.; Kim, C.W.; Reis, S.T.D.

    2004-01-01

    Chemical durability, glass formation tendency, and other properties of iron alumina phosphate glasses containing 70 wt% of a simulated high level nuclear waste (HLW), doped with different amounts of Cr 2 O 3 , have been investigated. All of the iron alumina phosphate glasses had an outstanding chemical durability as measured by their small dissolution rate (1 . 10 -9 g/(cm 2 . min)) in deionized water at 90 C for 128 d, their low normalized mass release as determined by the product consistency test (PCT) and a barely measurable corrosion rate of 2 . d) after 7 d at 200 C by the vapor hydration test (VHT). The solubility limit for Cr 2 O 3 in the iron phosphate melts was estimated at 4.1 wt%, but all of the as-annealed melts contained a few percent of crystalline Cr 2 O 3 that had no apparent effect on the chemical durability. The chemical durability was unchanged after deliberate crystallization, 48 h at 650 C. These iron phosphate waste forms, with a waste loading of at least 70 wt%, can be readily melted in commercial refractory crucibles at 1250 C for 2 to 4 h, are resistant to crystallization, meet all current US Department of Energy requirements for chemical durability, and have a solubility limit for Cr 2 O 3 which is at least three times larger than that for borosilicate glasses. (orig.)

  7. Retention of dental custom cast posts using zinc phosphate cement: A Systematic Review of Literature

    Directory of Open Access Journals (Sweden)

    Marzieh Alikhasi

    2018-03-01

    Conclusion: Our review showed that the retention of cast posts cemented with zinc phosphate in controlled condition is moderate and factors including post material and length could influence the retention of the post.

  8. The heat storage material based on paraffin-modified multilayer carbon nanotubes with Nickel-zinc ferrite

    Science.gov (United States)

    Shchegolkov, A.; Shchegolkov, A.; Dyachkova, T.; Semenov, A.

    2018-02-01

    The paper presents an investigation of magnetically controlled heat-storage material based on paraffin, modified with multilayer carbon nanotubes with nickel-zinc ferrite. The technology of obtaining nanomodified material capable of interacting with magnetic field is presented. The study of the heat-exchange processes of charge/discharge with the help of magnetic field are carried out.

  9. Experimental and theoretical approach on the optical properties of zinc borotellurite glass doped with dysprosium oxide

    Science.gov (United States)

    Halimah, M. K.; Ami Hazlin, M. N.; Muhammad, F. D.

    2018-04-01

    A series of glass samples with chemical formula {[(TeO2)0.7(B2O3)0.3]0.7(ZnO)0.3}1 - x(Dy2O3)x where x = 0.01, 0.02, 0.03, 0.04 and 0.05 M fraction were synthesized through conventional melt-quenching method. The most common way to fabricate a glass material is by fusion of two or more component oxides followed by their quenching. This technique is known as melt-quenching technique. Kaur et al. (2016) [1] highlighted that the melt-quenching method able to enhance the mechanical properties like hardness and flexural strength of the material. The nature of the glass systems is proven to be amorphous based on the XRD pattern. The FTIR spectra of the glass systems confirm the existence of five bands which are assigned for the BO4, BO3, TeO4 and TeO3 vibrational groups. The density of the glass systems is increased with the addition of Dy2O3 while the molar volume is found to be inversely proportional to the density of the proposed glass. The optical properties of the glasses are determined through the absorption spectra obtained from the UV-VIS spectrophotometer. From the absorption spectra, the indirect and direct optical band gaps and the Urbach energy are found to be inversely proportional to each other. As the molar fraction of the Dy2O3 increased, the optical band gaps are observed to increase as opposed to the Urbach energy. For this glass system, the values of refractive index, electronic polarizability, oxide ion polarizability and the optical basicity are found to decrease as the addition of the dysprosium oxide is increased. From the emission spectra, two intense blue and yellow emission bands are observed, which correspond to the 4F9/2 → 6H15/2 and 4F9/2 → 6H13/2 transitions of Dy3 + ions respectively. The CIE chromaticity coordinates of the zinc borotellurite glass systems are found to be located in the white light region. Generation of white light The generation of the white light can be achieved by using two emission bands which comprise of the yellow

  10. Development of novel strontium containing bioactive glass based calcium phosphate cement.

    Science.gov (United States)

    D'Onofrio, A; Kent, N W; Shahdad, S A; Hill, R G

    2016-06-01

    The aim of this study was to investigate the effect on properties of increasing strontium substitution for calcium in bioactive glasses used as precursors for novel calcium phosphate cements. Glasses were produced by progressively substituting strontium for calcium. Cements were prepared by mixing the glass powder with Ca(H2PO4)2 powder with a 2.5% solution of Na2HPO4. Setting times and compressive strength were measured after 1h, 1 day, 7 days and 28 days immersion in Tris buffer solution. X-ray diffraction (XRD), Fourier transform infrared spectroscopy and radiopacity were measured and crystal morphology was assessed using scanning electron microscopy. A correlation between the phases formed, morphology of the crystallites, setting time and compressive strength were analyzed. Setting time increased proportionally with strontium substitution in the glass up to 25%, whereas for higher substitutions it decreased. Compressive strength showed a maximum value of 12.5MPa and was strongly influenced by the interlocking of the crystals and their morphology. XRD showed that the presence of strontium influenced the crystal phases formed. Octacalcium phosphate (Ca8H2(PO4)6·5H2O, OCP) was the main phase present after 1h and 1 day whereas after 28 days OCP was completely transformed to strontium-containing hydroxyapatite (SrxCa(10-x)(PO4)6(OH)2, SrHA). Radiopacity increased proportionally to strontium substitution in the glass. A novel method to develop a bone substitute forming in vitro SrHA as a final product by using a bioactive glass as a precursor was shown. These novel injectable bioactive glass cements are promising materials for dental and orthopedic applications. Further in vivo characterizations are being conducted. Copyright © 2016 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  11. Thermal, structural and magnetic properties of some zinc phosphate glasses doped with manganese ions

    International Nuclear Information System (INIS)

    Pascuta, Petru; Bosca, Maria; Borodi, Gheorghe; Culea, Eugen

    2011-01-01

    Research highlights: → MnO) x .(P 2 O 5 ) 40 .(ZnO) 60-x glasses (0 ≤ x ≤ 20 mol%) were prepared by the melt-quenching technique. → The DTA data indicate a good thermal stability of the studied glasses. → EPR spectra shows isolated Mn 2+ ions in octahedral symmetric sites or to associated ones when the Mn 2+ ions are involved in dipole-dipole and/or superexchange interactions. → The magnetic susceptibility data revealed superexchange magnetic interactions involving manganese ions, antiferromagnetically coupled for the sample containing 20 mol% MnO. - Abstract: (MnO) x .(P 2 O 5 ) 40 .(ZnO) 60-x glasses containing different concentrations of MnO ranging from 0 to 20 mol% were prepared by the melt-quenching technique. The samples had a fixed P 2 O 5 content of 40 mol% and the MnO:ZnO ratio was varied. The thermal, structural and magnetic properties of these glasses were investigated by means of differential thermal analysis (DTA), electron paramagnetic resonance (EPR) and magnetic susceptibility measurements. Compositional dependence of the glass transition (T g ), crystallization (T p ) and melting temperatures were determined by DTA investigations. From the dependence of the T g on the heating rate (a), the activation energy of the glass transition (E g ) was calculated. The fragility index (F) for the studied glasses was determined to see whether these materials are obtained from kinetically strong-glass-forming (KS) or kinetically fragile-glass forming (KF) liquids. The EPR spectra of the studied glasses revealed absorptions centered at g ∼ 2.0, 3.3 and 4.3. The compositional variations of the intensity and line width of these absorption lines was interpreted in terms of the variation in the concentration of the Mn 2+ and Mn 3+ ions in the glass and the interaction between the manganese ions. EPR and magnetic susceptibility data reveal that both Mn 2+ and Mn 3+ ions are present in the studied glasses, their relative concentration being dependent on

  12. Eu{sup 3+} emission in phosphate glasses with high UV transparency

    Energy Technology Data Exchange (ETDEWEB)

    Silva, G.H. [Laboratório de Espectroscopia de Materiais (LEM), Departamento de Física, Universidade Federal de Juiz de Fora, CEP 36036-900 Juiz de Fora, MG (Brazil); Anjos, V., E-mail: virgilio@fisica.ufjf.br [Laboratório de Espectroscopia de Materiais (LEM), Departamento de Física, Universidade Federal de Juiz de Fora, CEP 36036-900 Juiz de Fora, MG (Brazil); Bell, M.J.V. [Laboratório de Espectroscopia de Materiais (LEM), Departamento de Física, Universidade Federal de Juiz de Fora, CEP 36036-900 Juiz de Fora, MG (Brazil); Carmo, A.P. [Instituto Federal Fluminense-Campus Cabo Frio, CP 112015, CEP 28909-971 Cabo Frio, RJ (Brazil); Pinheiro, A.S.; Dantas, N.O. [Laboratório de Novos Materiais Isolantes e Semicondutores (LNMIS), Instituto de Física, Universidade Federal de Uberlândia, CP 593, CEP 38400-902 Uberlândia, MG (Brazil)

    2014-10-15

    We report a study of the phosphate glass PZABP (P{sub 2}O{sub 5}–ZnO–Al{sub 2}O{sub 3}–BaO–PbO) doped with europium (Eu{sup 3+}) in different concentrations. Absorption, photoluminescence and time resolved photoluminescence were used to investigate the influence of increasing Eu{sup 3+} concentrations. The present glass exhibits Eu{sup 3+} absorption bands in the ultraviolet region (about 300 nm) due to the high transparency of the system compared to other phosphate glasses. In this way, it was possible to obtain the Judd–Ofelt parameters from the emission and absorption spectra. Moreover, a strong red emission attributed to the transition {sup 5}D{sub 0}→{sup 7}F{sub 2} of Eu{sup 3+} (611 nm) was observed. It was found that the radiative lifetime and the quantum efficiency of the Eu{sup 3+} level, {sup 5}D{sub 0}, do not suffer a significant change as the concentration of Eu{sup 3+} ions increases. - Highlights: • UV transparent glass matrix is used for Eu{sup 3+} doping. • Judd–Ofelt parameters from the emission and absorption spectra were obtained. • Red emission attributed to the transition {sup 5}D{sub 0}→{sup 7}F{sub 2} of Eu{sup 3+} (611 nm) was observed.

  13. Structure and Dynamics on Superionic Conducting Phosphate Glasses By Neutron Scattering

    International Nuclear Information System (INIS)

    Kartini, E.; Kennedy, S.J.; Itoh, K.; Arai, M.; Mezei, F.; Nakamura, M.

    2005-01-01

    Full text: A series of Neutron Diffraction and Inelastic scattering experiments have been performed on superionic conducting phosphate glasses, MX-MPO 3 (M=Ag; X=I,S) and AgI-Ag 2 S-AgPO 3 . These materials are used for solid state battery, due to high conductivity up to 10 -2 S.cm -1 at ambient temperature. The conductivity of the insulator glass AgPO 3 ∼ 10 -7 S.cm -1 . Interestingly, the structure factor S(Q) exhibits a prepeak at very low Q∼0.7 Aangstroem -1 related to the IRO ∼ 10-12 Aangstroem and the Radial Distribution Function gives an extra peak ∼ 2.8 Aangstroem -1 that corresponds to Ag-I correlation. The dynamic structure factor S(Q,ω), shows a Boson peak at low energy ∼ 2.5 meV that increases with composition and temperature. These behaviors seem to be universal for the AgI doped glasses, but the origin remains not well understood. Increasing mobility of the Ag ions, due to expansion of the phosphate network plays a dominant role on raising the ionic conductivity, prepeak and Boson peak. (authors)

  14. Effect of the melting conditions on the properties of radiation color centers in lanthanum phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Karapetyan, G.O.; Rusan, V.V.; Yashchurzhinskaya, O.A.

    1986-01-01

    The authors investigate the spatial effects of ionizing radiation on the radiation processes in phosphate glasses to make a comparative estimate of the radiation yield from the radiation color centers (RCC) of different types. A study is made of their behavior under thermal decoloration. The results of a comparison of the integrated intensities of the ESR signal from trapping centers are given. The ESR spectrum of the glasses are presented--one differs slightly from the others. On the basis of the result of processing the ESR and optical spectra of gamma-irradiated lanthanum phosphate glasses synthesized under various conditions, the radiation yield of the RCC and the behavior of the intensity of their absorption under thermodecoloration are significantly affected by the conditions of synthesis of the glass.

  15. Micro-Raman spectroscopy studies of the phase separation mechanisms of transition-metal phosphate glasses

    International Nuclear Information System (INIS)

    Mazali, Italo Odone; Alves, Oswaldo Luiz; Gimenez, Iara de Fatima

    2009-01-01

    Glass-ceramics are prepared by controlled separation of crystal phases in glasses, leading to uniform and dense grain structures. On the other hand, chemical leaching of soluble crystal phases yields porous glass-ceramics with important applications. Here, glass/ceramic interfaces of niobo-, vanado- and titano-phosphate glasses were studied by micro-Raman spectroscopy, whose spatial resolution revealed the multiphase structures. Phase-separation mechanisms were also determined by this technique, revealing that interface composition remained unchanged as the crystallization front advanced for niobo- and vanadophosphate glasses (interface-controlled crystallization). For titanophosphate glasses, phase composition changed continuously with time up to the equilibrium composition, indicating a spinodal-type phase separation. (author)

  16. Mechanical characterization and single asperity scratch behaviour of dry zinc and manganese phosphate coatings

    NARCIS (Netherlands)

    Ernens, D.; de Rooij, M. B.; Pasaribu, H. R.; van Riet, E.J.; van Haaften, W.M.; Schipper, D. J.

    The goal of this study is to characterise the mechanical properties of zinc and manganese phosphate coatings before and after running in. The characterization is done with nano-indentation to determine the individual crystal hardness and single asperity scratch tests to investigate the deformation

  17. Electroplating U-0.75 Ti, 105-mm, XM774 penetrators with nickel and zinc

    International Nuclear Information System (INIS)

    Dini, J.W.; Johnson, H.R.

    1976-06-01

    Procedures were developed and utilized whereby 105-mm U-Ti penetrators were plated with 1.0 mil of nickel and 0.2 mil of zinc and then chromated. Twenty-three full-size penetrators were coated to demonstrate the feasibility of the system and to provide parts for ballistic tests. Dimensional inspection of the parts before and after etching and plating revealed the coating process to be viable and repeatable

  18. Adhesive bonding of super-elastic titanium-nickel alloy castings with a phosphate metal conditioner and an acrylic adhesive.

    Science.gov (United States)

    Matsumura, H; Tanoue, N; Yanagida, H; Atsuta, M; Koike, M; Yoneyama, T

    2003-06-01

    The purpose of the current study was to evaluate the bonding characteristics of super-elastic titanium-nickel (Ti-Ni) alloy castings. Disk specimens were cast from a Ti-Ni alloy (Ti-50.85Ni mol%) using an arc centrifugal casting machine. High-purity titanium and nickel specimens were also prepared as experimental references. The specimens were air-abraded with alumina, and bonded with an adhesive resin (Super-Bond C & B). A metal conditioner containing a phosphate monomer (Cesead II Opaque Primer) was also used for priming the specimens. Post-thermocycling average bond strengths (MPa) of the primed groups were 41.5 for Ti-Ni, 30.4 for Ti and 19.5 for Ni, whereas those of the unprimed groups were 21.6 for Ti, 19.3 for Ti-Ni and 9.3 for Ni. Application of the phosphate conditioner elevated the bond strengths of all alloy/metals (P elastic Ti-Ni alloy castings can be achieved with a combination of a phosphate metal conditioner and a tri-n-butylborane-initiated adhesive resin.

  19. Synthesis, characterization and bioactivity of a calcium-phosphate glass-ceramics obtained by the sol-gel processing method

    International Nuclear Information System (INIS)

    Jmal, Nouha; Bouaziz, Jamel

    2017-01-01

    In this work, a calcium-phosphate glass-ceramics was successfully obtained by heat treatment of a mixture of 26.52 in wt.% of fluorapatite (Fap) and 73.48 in wt.% of 77S (77 SiO 2 −14 CaO−9 P 2 O 5 in wt.%) gel. The calcium phosphate-glass-ceramics was prepared by sol-gel process with tetraethyl orthosilicate (TEOS), triethyl phosphate (TEP), calcium nitrate and fluorapatite. The synthesized powders were characterized by some commonly used tools such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), 31 P magic angle spinning nuclear magnetic resonance (MAS-NMR), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and thin-film X-ray diffraction (TF-XRD). The obtained results seemed to confirm the nucleation and growth of hydroxyapatite (Hap) nano-phase in the glass. Moreover, an in-vitro evaluation of the glass-ceramic was performed. In addition, to assess its bioactive capacity, it was soaked in simulated body fluid (SBF) at different time intervals. The SEM, EDS and TF-XRD analyses showed the deposition of hydroxyapatite on the surface of the specimens after three days of immersion in SBF solution. The mechanical properties of the obtained material such as rupture strength, Vickers hardness and elastic modulus were measured. In addition, the friction coefficient of calcium phosphate-glass-ceramics was tested. The values of the composite of rupture strength (24 MPa), Vickers hardness (214 Hv), Young's modulus (52.3 GPa), shear modulus (19 GPa) and friction coefficient (0.327) were obtained. This glass-ceramics can have useful applications in dental prostheses. Indeed, this material may have promising applications for implants because of its content of fluorine, the effective protector against dental caries. - Highlights: • A novel three phases Fap-Hap-glass-ceramics is prepared by sol–gel route. • Results showed a nucleation and growth of hydroxyapatite nano-phase in the glass. • Fap-Hap-glass

  20. 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.

  1. Thermal properties and surface reactivity in simulated body fluid of new strontium ion-containing phosphate glasses.

    Science.gov (United States)

    Massera, J; Petit, L; Cardinal, T; Videau, J J; Hupa, M; Hupa, L

    2013-06-01

    In this paper, we investigate the effect of SrO substitution for CaO in 50P₂O₅-10Na₂-(40-x)CaO-xSrO glass system (x from 0 to 40) on the thermal and structural properties and also on the glass reactivity in simulated body fluid (SBF) in order to find new glass candidates for biomedical glass fibers. The addition of SrO at the expense of CaO seems to restrain the leaching of phosphate ions in the solution limiting the reduction of the solution pH. We observed the formation of an apatite layer at the surface of the glasses when in contact with SBF. SrO and MgO were found in the apatite layer of the strontium ion-containing glasses, the concentration of which increases with an increase of SrO content. We think that it is the presence of MgO and SrO in the layer which limits the leaching of phosphate in the solution and thus the glass dissolution in SBF.

  2. Preparation and characterization of phosphate glasses containing titanium and vanadium

    Energy Technology Data Exchange (ETDEWEB)

    Kaoua, S. [Laboratoire de Chimie du Solide, Faculte des Sciences Ain Chock, Casablanca (Morocco); Krimi, S. [Laboratoire de Chimie du Solide, Faculte des Sciences Ain Chock, Casablanca (Morocco)]. E-mail: krimisaida@yahoo.fr; El Jazouli, A. [Laboratoire de Chimie des Materiaux Solides, Faculte des Sciences Ben M' Sik, Casablanca (Morocco); Hlil, E.K. [Laboratoire de Cristallographie du CNRS, Grenoble (France)]. E-mail: hlil@grenoble.cnrs.fr; Waal, D. de [Department of Chemistry, University of Pretoria, 0002 Pretoria (South Africa)

    2007-02-21

    Na{sub 5-x}Ti{sub 1-x}V {sub x}(PO{sub 4}){sub 3} (0 {<=} x {<=} 1) phosphates glasses have been obtained in air by direct fusion of Na{sub 2}CO{sub 3}, TiO{sub 2}, V{sub 2}O{sub 5} and (NH{sub 4}){sub 2}HPO{sub 4}. Vitreous Na{sub 5}Ti(PO{sub 4}){sub 3} is colourless while the glasses containing vanadium are green, due to the reduction of V{sup 5+} to V{sup 4+}. Glass transition and crystallization temperatures (T {sub g}, T {sub c}) decrease when the amount of vanadium increases. EPR, Raman and UV-vis spectra have been investigated. The results are consistent with the presence of V{sup 4+} ions in distorted octahedra with very strong V-O bond.

  3. Characterization of iron phosphate glasses prepared by microwave heating; Obtencao de vidros fosfatos contendo ferro por meio do aquecimento em fornos de microondas

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Fabio Jesus Moreira de

    2006-07-01

    Phosphate glasses have been investigated since the fifties, because they are relatively easy to prepare, have low melting temperatures (1000 deg C - 1200 deg C), and low glass transition. However, these glasses were very sensitive to humidity, showing a very low chemical durability. Iron phosphate glasses have been prepared by melting inorganic precursors in conventional electric furnaces and induction furnaces. By adding iron, phosphate glasses became chemical resistant and were thought to be used as nuclear waste forms or mechanical resistance fibers. The use of microwaves has been investigated because it makes possible a fast and homogeneous heating of the materials. Microwave promotes the self-heating of the material by the interaction of the external electromagnetic field with the molecules and ions of the material. Niobium phosphate glasses was also produced already through the heating of precursors in microwave ovens. Other glasses containing iron in theirs structure was produced by conventional furnaces and they had your structures analyzed. But even so, it was not still published synthesis of iron phosphate glasses starting from the melting of precursors materials in microwave ovens. In the present work mixtures of (NH{sub 4}){sub 2}HPO{sub 4} and Fe{sub 3}O{sub 4} or (NH{sub 4}){sub 2}HPO{sub 4} and Fe{sub 2}O{sub 3} were exposed to microwave energy with electromagnetic waves of 2,45 GHz. It was proposed that the absorption of this radiation for the material causes the heating from room temperature to melting temperature. The obtained iron phosphate glasses was analyzed by X-ray diffraction, Moessbauer spectroscopy, and Differential Thermal Analysis. Iron phosphate glasses were also produced in electrical furnaces for comparison. (author)

  4. Radioactivity of Ore Sites of Lead, Zinc and Phosphate in Serbia

    International Nuclear Information System (INIS)

    Todorovic, D.; Jankovic, M.; Nikolic, J.; Kosutic, D.

    2011-01-01

    Natural resources such as ores contain radioactive nuclides at various concentrations. Therefore it is important to investigate the radioactivity in these resources as well as in the soil at the locations of ore deposits. For that reason we conducted preliminary measurements in the soil samples taken from the locations of lead and zinc ore deposits (Bosilegrad and Raska) and from the locations of phosphate ore deposits of phosphate (Bosilegrad). The activity concentrations of radionuclides in soil samples were determined by gamma spectrometry (HPGe detector, relative efficiency 23 %). Results showed the presence of natural radionuclides 226Ra, 232Th, 40K, 235U, 238U as well as the produced radionuclide 137Cs (from the Chernobyl accident). Ambient gamma radiation dose rate in ground level air was also measured. (author)

  5. Raman scattering boson peak and differential scanning calorimetry studies of the glass transition in tellurium-zinc oxide glasses.

    Science.gov (United States)

    Stavrou, E; Tsiantos, C; Tsopouridou, R D; Kripotou, S; Kontos, A G; Raptis, C; Capoen, B; Bouazaoui, M; Turrell, S; Khatir, S

    2010-05-19

    Raman scattering and differential scanning calorimetry (DSC) measurements have been carried out on four mixed tellurium-zinc oxide (TeO(2))(1 - x)(ZnO)(x) (x = 0.1, 0.2, 0.3, 0.4) glasses under variable temperature, with particular attention being given to the respective glass transition region. From the DSC measurements, the glass transition temperature T(g) has been determined for each glass, showing a monotonous decrease of T(g) with increasing ZnO content. The Raman study is focused on the low-frequency band of the glasses, the so-called boson peak (BP), whose frequency undergoes an abrupt decrease at a temperature T(d) very close to the respective T(g) values obtained by DSC. These results show that the BP is highly sensitive to dynamical effects over the glass transition and provides a means for an equally reliable (to DSC) determination of T(g) in tellurite glasses and other network glasses. The discontinuous temperature dependence of the BP frequency at the glass transition, along with the absence of such a behaviour by the high-frequency Raman bands (due to local atomic vibrations), indicates that marked changes of the medium range order (MRO) occur at T(g) and confirms the correlation between the BP and the MRO of glasses.

  6. Raman scattering boson peak and differential scanning calorimetry studies of the glass transition in tellurium-zinc oxide glasses

    International Nuclear Information System (INIS)

    Stavrou, E; Tsiantos, C; Tsopouridou, R D; Kripotou, S; Kontos, A G; Raptis, C; Capoen, B; Bouazaoui, M; Turrell, S; Khatir, S

    2010-01-01

    Raman scattering and differential scanning calorimetry (DSC) measurements have been carried out on four mixed tellurium-zinc oxide (TeO 2 ) 1-x (ZnO) x (x = 0.1, 0.2, 0.3, 0.4) glasses under variable temperature, with particular attention being given to the respective glass transition region. From the DSC measurements, the glass transition temperature T g has been determined for each glass, showing a monotonous decrease of T g with increasing ZnO content. The Raman study is focused on the low-frequency band of the glasses, the so-called boson peak (BP), whose frequency undergoes an abrupt decrease at a temperature T d very close to the respective T g values obtained by DSC. These results show that the BP is highly sensitive to dynamical effects over the glass transition and provides a means for an equally reliable (to DSC) determination of T g in tellurite glasses and other network glasses. The discontinuous temperature dependence of the BP frequency at the glass transition, along with the absence of such a behaviour by the high-frequency Raman bands (due to local atomic vibrations), indicates that marked changes of the medium range order (MRO) occur at T g and confirms the correlation between the BP and the MRO of glasses.

  7. Improved ionic conductivity of lithium-zinc-tellurite glass-ceramic electrolytes

    Directory of Open Access Journals (Sweden)

    W. Widanarto

    Full Text Available An enhancement in the secondary battery safety demands the optimum synthesis of glass-ceramics electrolytes with modified ionic conductivity. To achieve improved ionic conductivity and safer operation of the battery, we synthesized Li2O included zinc-tellurite glass-ceramics based electrolytes of chemical composition (85-xTeO2·xLi2O·15ZnO, where x = 0, 5, 10, 15 mol%. Samples were prepared using the melt quenching method at 800 °C followed by thermal annealing at 320 °C for 3 h and characterized. The effects of varying temperature, alternating current (AC frequency and Li2O concentration on the structure and ionic conductivity of such glass-ceramics were determined. The SEM images of the annealed glass-ceramic electrolytes displayed rough surface with a uniform distribution of nucleated crystal flakes with sizes less than 1 μm. X-ray diffraction analysis confirmed the well crystalline nature of achieved electrolytes. Incorporation of Li2O in the electrolytes was found to generate some new crystalline phases including hexagonal Li6(TeO6, monoclinic Zn2Te3O8 and monoclinic Li2Te2O5. The estimated crystallite size of the electrolyte was ranged from ≈40 to 80 nm. AC impedance measurement revealed that the variation in the temperatures, Li2O contents, and high AC frequencies have a significant influence on the ionic conductivity of the electrolytes. Furthermore, electrolyte doped with 15 mol% of Li2O exhibited the optimum performance with an ionic conductivity ≈2.4 × 10−7 S cm−1 at the frequency of 54 Hz and in the temperature range of 323–473 K. This enhancement in the conductivity was attributed to the sizable alteration in the ions vibration and ruptures of covalent bonds in the electrolytes network structures. Keywords: Zinc-tellurite, Glass-ceramics, X-ray diffraction, Ionic conductivity, Lithium oxide

  8. Synthesis and characterization of tricalcium phosphate ceramics doped with zinc

    International Nuclear Information System (INIS)

    Kai, K.C.; Marchi, J.; Ussui, V.; Bressiani, A.H.A.

    2011-01-01

    Due to its biocompatibility, the tricalcium phosphate (TCP) is used as a biomaterial for bone replacement and reconstruction. Zinc (Zn) can replace calcium in the crystal structure of TCP to be added in small quantities, can result in stimulatory effects on bone formation in vitro and in vivo. In this work, pure TCP and Zn-TCP, with general formula (Ca_1_-_xZn_x)_3 (PO_4)_2 and 0 ≤ x ≤ 0.0225, were prepared by wet synthesis, from precursors Ca(OH)_2, H_3PO_4 and ZnO, after calcinated at 800 deg C and characterized by X-ray diffraction, specific surface area, agglomerate size distribution, differential thermal analysis and scanning electron microscopy. The results showed that the addition of small amounts of Zn resulted in TCP with suitable densification and higher specific surface area, may be promising as biomaterial due to the stimulatory effects of zinc associated with suitable mechanical properties of the final material. (author)

  9. Electrophoretic deposition of nickel zinc ferrite nanoparticles into microstructured patterns

    Directory of Open Access Journals (Sweden)

    Stefan J. Kelly

    2016-05-01

    Full Text Available Using DC electric fields, nickel-zinc ferrite (Ni0.5Zn0.5Fe2O4 nanoparticles (Dh =16.6 ± 3.6 nm are electrophoretically deposited onto silicon substrates to form dense structures defined by photoresist molds. Parameters such as electric field, bath composition, and deposition time are tuned to produce films ranging in thickness from 177 to 805 nm. The deposited films exhibit soft magnetic properties with a saturation magnetization of 60 emu/g and a coercivity of 2.6 kA/m (33 Oe. Additionally, the influence of the photoresist mold on the deposit profile is studied, and patterned films with different shapes (lines, squares, circles, etc. are demonstrated with feature sizes down to 5 μm.

  10. Evaluation of lead-iron-phosphate glass as a high-level waste form

    International Nuclear Information System (INIS)

    Chick, L.A.; Bunnell, L.R.; Strachan, D.M.; Kissinger, H.E.; Hodges, F.N.

    1986-09-01

    The lead-iron-phosphate (Pb-Fe-P) glass developed at Oak Ridge National Laboratory was evaluated for its potential as an improvement over the current reference nuclear waste form, borosilicate (B-Si) glass. The evaluation was conducted as part of the Second Generation HLW Technology Subtask of the Nuclear Waste Treatment Program at Pacific Northwest Laboratory. The purpose of this work was to investigate possible alternatives to B-Si glass as second-generation waste forms. While vitreous Pb-Fe-P glass appears to have substantially better chemical durability than B-Si glass, severe crystallization or devitrification leading to deteriorated chemical durability would result if this glass were poured into large canisters as is the procedure with B-Si glass. Cesium leach rates from this crystallized material are orders of magnitude greater than those from B-Si glass. Therefore, to realize the potential performance advantages of the Pb-Fe-P material in a nuclear waste form, the processing method would have to cool the material rapidly to retain its vitreous structure

  11. Adhesion strength of nickel and zinc coatings with copper base electroplated in conditions of external stimulation by laser irradiance

    Directory of Open Access Journals (Sweden)

    V. V. Dudkina

    2013-04-01

    Full Text Available Purpose. The investigation of laser irradiance influence on the adhesion strength of nickel and zinc coatings with copper base and the research of initial stages of crystallization for nickel and zinc films. Methodology. Electrodeposition of nickel and zinc films from the standard sulphate electrolyte solutions was carried out on the laser-electrolytic installations, built on the basis of gas discharge CO2-laser and solid ruby laser KVANT-12. The adhesion strength of metal coatings with copper base are defined not only qualitatively using the method of meshing and by means of multiple bending, but also quantitatively by means of indention of diamond pyramid into the border line between coating and base of the side section. Spectrum microanalysis of the element composition of the border line “film and base” is carried out using the electronic microscope REMMA-102-02. Findings. Laser irradiance application of the cathode region in the process of electroplating of metal coatings enables the adhesion strength improvement of coating with the base. Experimental results of adhesive strength of the films and the spectrum analysis of the element composition for the border line between film and base showed that during laser-assisted electroplating the diffusion interaction between coating elements and the base metal surface takes place. As a result of this interaction the coating metal diffuses into the base metal, forming transition diffused layer, which enhances the improvement of adhesion strength of the coatings with the base. Originality. It is found out that ion energy increase in the double electric layer during interaction with laser irradiance affects cathode supersaturation at the stage of crystallization. Hence, it also affects the penetration depth of electroplated material ions into the base metal, which leads to the adhesion strength enhancement. Practical value. On the basis of research results obtained during the laser

  12. Optical bistability in Er-Yb codoped phosphate glass microspheres at room temperature

    NARCIS (Netherlands)

    Warda, Jonathan M.; O'Shea, Danny G.; Shortt, Brian J.; Chormaic, Sile Nic

    2007-01-01

    We experimentally demonstrate optical bistability in Er(3+)-Yb(3+) phosphate glass microspheres at 295 K. Bistability is associated with both Er(3+) fluorescence and lasing behavior, and chromatic switching. The chromatic switching results from an intrinsic mechanism exploiting the thermal coupling

  13. Synthesis, characterization and bioactivity of a calcium-phosphate glass-ceramics obtained by the sol-gel processing method

    Energy Technology Data Exchange (ETDEWEB)

    Jmal, Nouha, E-mail: jmalnouha@gmail.com; Bouaziz, Jamel

    2017-02-01

    In this work, a calcium-phosphate glass-ceramics was successfully obtained by heat treatment of a mixture of 26.52 in wt.% of fluorapatite (Fap) and 73.48 in wt.% of 77S (77 SiO{sub 2}−14 CaO−9 P{sub 2}O{sub 5} in wt.%) gel. The calcium phosphate-glass-ceramics was prepared by sol-gel process with tetraethyl orthosilicate (TEOS), triethyl phosphate (TEP), calcium nitrate and fluorapatite. The synthesized powders were characterized by some commonly used tools such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), {sup 31}P magic angle spinning nuclear magnetic resonance (MAS-NMR), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and thin-film X-ray diffraction (TF-XRD). The obtained results seemed to confirm the nucleation and growth of hydroxyapatite (Hap) nano-phase in the glass. Moreover, an in-vitro evaluation of the glass-ceramic was performed. In addition, to assess its bioactive capacity, it was soaked in simulated body fluid (SBF) at different time intervals. The SEM, EDS and TF-XRD analyses showed the deposition of hydroxyapatite on the surface of the specimens after three days of immersion in SBF solution. The mechanical properties of the obtained material such as rupture strength, Vickers hardness and elastic modulus were measured. In addition, the friction coefficient of calcium phosphate-glass-ceramics was tested. The values of the composite of rupture strength (24 MPa), Vickers hardness (214 Hv), Young's modulus (52.3 GPa), shear modulus (19 GPa) and friction coefficient (0.327) were obtained. This glass-ceramics can have useful applications in dental prostheses. Indeed, this material may have promising applications for implants because of its content of fluorine, the effective protector against dental caries. - Highlights: • A novel three phases Fap-Hap-glass-ceramics is prepared by sol–gel route. • Results showed a nucleation and growth of hydroxyapatite nano-phase in the glass.

  14. Zinc electrode - its behaviour in the nickel oxide-zinc accumulator

    Energy Technology Data Exchange (ETDEWEB)

    1984-01-01

    Certain aspects of zinc electrode reaction and behavior are investigated in view of their application to batteries. The properties of the zinc electrode in a battery system are discussed, emphasizing porous structure. Shape change is emphasized as the most important factor leading to limited battery cycle life. It is shown that two existing models of shape change based on electroosmosis and current distribution are unable to consistently describe observed phenomena. The first stages of electrocrystallization are studied and the surface reactions between the silver substrate and the deposited zinc layer are investigated. The reaction mechanism of zinc and amalgamated zinc in an alkaline electrolyte is addressed, and the batter system is studied to obtain information on cycling behavior and on the shape change phenomenon. The effect on cycle behavior of diferent amalgamation techniques of the zinc electrode and several additives is addressed. Impedance measurements on zinc electrodes are considered, and battery behavior is correlated with changes in the zinc electrode during cycling. 193 references.

  15. Hierarchical one-dimensional ammonium nickel phosphate microrods for high-performance pseudocapacitors

    CSIR Research Space (South Africa)

    Raju, K

    2015-12-01

    Full Text Available :17629 | DOI: 10.1038/srep17629 www.nature.com/scientificreports Hierarchical One-Dimensional Ammonium Nickel Phosphate Microrods for High-Performance Pseudocapacitors Kumar Raju1 & Kenneth I. Ozoemena1,2 High-performance electrochemical capacitors... OPEN w w w . n a t u r e . c o m / s c i e n t i f i c r e p o r t s / 2S C I E N T I F I C REPORTS | 5:17629 | DOI: 10.1038/srep17629 Hierarchical 1-D and 2-D materials maximize the supercapacitive properties due to their unique ability to permit ion...

  16. Microstructural effects on the initiation of zinc phosphate coatings on 2024-T3 aluminum alloy

    International Nuclear Information System (INIS)

    Susac, D.; Sun, X.; Li, R.Y.; Wong, K.C.; Wong, P.C.; Mitchell, K.A.R.; Champaneria, R.

    2004-01-01

    The initiation of coatings deposited on to 2024-T3 aluminum alloy from supersaturated zinc phosphating solutions has been studied using scanning Auger microscopy (SAM), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The alloy microstructure, especially associated with the second-phase particles, strongly affects the formation stages of the coating process, where etching of the substrate has a significant role. At the start, zinc phosphate (ZPO) crystals form on the Al-Cu-Mg second-phase particles, rather than on the matrix or on the Al-Cu-Fe-Mn particles, with the initial nucleation appearing at interfaces between Al-Cu-Mg particles and the matrix. In contrast, the formation of the ZPO coating is delayed on the cathodic Al-Cu-Fe-Mn particles, compared to those of the Al-Cu-Mg composition. When the coating process is completed, the whole sample surface is covered with ZPO although its thickness varies at the different micro-regions

  17. Zinc, nickel, and cobalt ions removal from aqueous solution and plating plant wastewater by modified Aspergillus flavus biomass: A dataset

    Directory of Open Access Journals (Sweden)

    Rauf Foroutan

    2017-06-01

    Full Text Available The biomass of Aspergillus flavus was modified by calcium chloride to achieve a bioadsorbent for treating nickel, cobalt, and zinc ions from aqueous solutions. The information of pH, bioadsorbent dose, contact time, and temperature effect on the removal efficiency are presented. The data of Freundlich and Langmuir isotherm and pseudo-first-order and pseudo-second-order kinetic models are also depicted. The data showed that the maximum bioadsorption capacity of nickel, cobalt, and zinc ions is 32.26, 31.06 and 27.86 mg/g, respectively. The suitability of the bioadsorbent in heavy metals removal at field condition was tested with a real wastewater sample collected from a plating plant in the final part of this dataset. Based on the findings, the bioadsorbent was shown to be an affordable alternative for the removal of metals in the wastewater.

  18. Cadmium and zinc in soil solution extracts following the application of phosphate fertilizers.

    Science.gov (United States)

    Lambert, Raphaël; Grant, Cynthia; Sauvé, Sébastien

    2007-06-01

    This study investigated the solubility of cadmium and zinc in soils after the application of phosphate fertilizers containing those two metals. The solubility of cadmium and zinc was assessed by measuring their concentration in soil water extracts. Three monoammonium phosphate fertilizers containing various amounts of metals were applied on cultivated fields for 3 years at three different rates. In order to investigate the effects of long-term applications of fertilizers on the solubility of Cd and Zn, a similar design was used to apply contaminated fertilizers to soils in a laboratory experiment using a single fertilizer addition equivalent to 15 years of application. Phosphate fertilizers increased the concentration of Cd in soil extracts compared to control in 87% and 80% of the treatments in field and laboratory experiments respectively. Both increasing the rate of application and using fertilizer containing more Cd lead to higher Cd concentrations in extracts for the field and the laboratory experiments. The addition of the equivalent of 15 years of fertilizer application in the laboratory results in higher Cd concentration in extracts compared to the field experiment. For Zn, the fertilizer treatments enhanced the metal solution concentration in 83% of field treatments, but no significant correlations could be found between Zn inputs and its concentration in solution. In the laboratory, fertilizer additions increase the Zn concentrations in 53% of the treatments and decrease it in most of the other treatments. The decrease in Zn concentrations in the laboratory trial is attributed to the higher phosphate concentrations in the soil solution; which is presumed to have contributed to the precipitation of Zn-phosphates. For both trials, the metal concentrations in soil extracts cannot be related to the Zn concentration in the fertilizer or the rate of application. The high Zn to Cd ratio is presumably responsible for the Cd increase in the soil extracts due to

  19. Protein-adsorption and Ca-phosphate formation on chitosan-bioactive glass composite coatings

    Science.gov (United States)

    Wagener, V.; Boccaccini, A. R.; Virtanen, S.

    2017-09-01

    In the last years, chitosan-bioactive glass (BG) composites have been developed and investigated as bioactive coatings for orthopedic applications. The increase of bioactivity occurs due to the stimulation of calcium-phosphate/hydroxyapatite formation on the surface while the coating is degrading. In the present work, protein adsorption and its influence on calcium-phosphate precipitation was studied for the first time on such composite coatings. The experiments involved coating of 316L stainless steel substrates with chitosan (Ch) and chitosan-bioactive glass (Ch-BG) and immersion of the coated samples in two different bovine serum albumin (BSA) containing solutions, namely DI H2O (with pH adjusted to about 7.2 with diluted NaOH) and simulated body fluid (SBF). In order to investigate the influence of protein adsorption on calcium-phosphate precipitation, samples were also immersed in DI H2O and in SBF without BSA. Samples were analyzed by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). Surface analysis revealed that adsorption of BSA takes place on all studied samples and that protein adsorption is influenced by the presence of Ca2+ and PO43- ions. Bioactivity in the form of hydroxyapatite pre-stage formation is significantly increased on Ch-BG composite coating as compared with bare stainless steel surface. However, calcium-phosphate precipitation in SBF is reduced by the presence of BSA.

  20. The effects of uranium oxide high-level waste on the structure of iron phosphate glasses

    International Nuclear Information System (INIS)

    Badyal, Y.

    1998-01-01

    Because of their unusually good chemical durability, iron phosphate glasses are a natural candidate for a nuclear waste disposal glass. We have studied the effects of UO 2 high-level waste on the structure of iron phosphate glasses with both neutron and high-energy x-ray diffraction using the GLAD instrument of the Intense Pulsed Neutron Source and the 1-BM bending magnet beamline of the Advanced Photon Source, respectively. The results of neutron scattering, which is mostly sensitive to correlations involving light atoms i.e. O-O, Fe-O and P-O, suggest the main structural features of the base glass are largely unaffected by the addition of UO 2 . The nearest-neighbor P-O, Fe-O and O-O peaks remain at the same position in real space and their intensities scale approximately with concentration. These findings are consistent with the earlier results of Raman scattering and EXAFS on the Fe-K edge wherein both cases the spectra remain similar to the base glass. High-energy x-ray scattering which is sensitive to correlations involving the heavier atoms and thus complements the neutron measurements, is also consistent with uranium occupying interstitial sites in the relatively undisturbed base glass structure. However, important questions remain as to the precise local structure and oxidation state of uranium in these glasses

  1. Phosphate content influence on structural, spectroscopic, and lasing properties of Er,Yb-doped potassium-lanthanum phosphate glasses

    Czech Academy of Sciences Publication Activity Database

    Šulc, J.; Švejkar, R.; Jelínková, H.; Nejezchleb, K.; Nitsch, Karel; Cihlář, Antonín; Král, Robert; Ledinský, Martin; Fejfar, Antonín; Rodová, Miroslava; Zemenová, Petra; Nikl, Martin

    2016-01-01

    Roč. 55, č. 4 (2016), 1-10, č. článku 047102. ISSN 0091-3286 R&D Projects: GA ČR GAP204/12/0805 Institutional support: RVO:68378271 Keywords : erbium laser s * infrared laser s * laser materials modification * phosphate glass * diode -pumped eye-safe solid state laser Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.082, year: 2016

  2. The effect of zinc injection into PWR primary coolant on the reduction of radiation buildup and corrosion control. The solubilities of zinc, nickel and cobalt spinel oxides

    International Nuclear Information System (INIS)

    Miyajima, Kaori; Hirano, Hideo

    1999-01-01

    The use of zinc injection into PWR primary coolant to reduce radiation buildup has been widely studied, and te reduction effect has been experimentally confirmed. However, some items, such as the optimal concentration of zinc required to reduce radiation buildup, the corrosion control effect of zinc injection, and the influence of zinc injection on the integrity of fuel cladding, have not been clarified yet. In particular, the corrosion suppression effect of zinc remains unconfirmed. Therefore, it is necessary to measure and calculate the solubilities of zinc and nickel spinel oxides, which are formed on the surface of Ni-based alloys in PWR primary systems. In this study, in order to assess the effectiveness of zinc injection in the reduction of radiation buildup and the corrosion control of Ni-based alloy, the potential-pH diagrams for Zn-Cr-H 2 O, Ni-Cr-H 2 O, and Co-Cr-H 2 O systems at 300degC were constructed and the solubilities of Zn-Cr, Ni-Cr, and Co-Cr spinel oxides were calculated. It is concluded that under pH conditions for which NiCr 2 O 4 is stable, zinc injection is effective in corrosion control as well as in reducing radiation buildup. (author)

  3. Infrared and Raman investigation of rare-earth phosphate glasses for potential use as radioactive waste forms

    International Nuclear Information System (INIS)

    Morgan, S.H.

    1989-01-01

    This project was designed to investigate the properties of the rare-earth phosphate glass systems CeO 2 -P 2 O 5 and Pr 2 O 3 -P 2 O 5 for potential use as radioactive waste glasses. The glass-forming region and optimum processing parameters of these glass systems were investigated. The structure of the host glasses and glassed loaded with simulated waste elements was investigated using Raman and infrared spectroscopy. Because of the radical differences in the spectra of the molybdenum-loaded glasses, the structure of the MoO 3 -P 2 O 5 glass system was also investigated. 29 refs., 8 figs., 2 tabs

  4. Research, development and demonstration of nickel-zinc batteries for electric vehicle propulsion. Annual report, 1978

    Energy Technology Data Exchange (ETDEWEB)

    1979-10-01

    This is the first annual report of progress achieved under ANL Contract 31-109-38-4248. It covers the report period from 15 March 1978 to 15 August 1978. The nickel electrode development program is directed at the optimization of the electrical performance, specifically, in terms of increased cycle life. The work concentrated upon both the development of pilot plant facilities to produce nickel hydroxide and upon optimizing the manufacturing processes to produce nickel hydroxide which has high electrochemical utilization. The primary goal of the zinc electrode studies is to increase the cycle life of this electrode. This effort is primarily concentrating on the effect of additives upon shape change and cycle performance and on the mechanistic processes involved in the shape change. The separator effort has as its major goal the development of a low-cost separator which exhibits stability in the electrolyte, has uniform pores which are of a sufficiently small size to impede the growth of zinc dendrites, and exhibits low electrical resistance and good flexibility. The process itself is now optimized for pilot plant manufacture; hundreds of formulations have been produced and subsequently screened in both the laboratory and in actual cells. Promising formulations are presently being subjected to additional characterization tests and life cycles. The goal of the sealed cell studies is to determine the feasibility of sealed-cell operation. Large numbers of 20-Ah cells have been subjected to accelerated testing. These cells incorporated separator variations, active material additives, and internal design variations. Cycle lives up to 150 deep cycles were achieved. Cell failure modes are analyzed. 51 figures, 20 tables.

  5. UV-visible, Raman and E.S.R. studies of gamma-irradiated NiO-doped sodium metaphosphate glasses.

    Science.gov (United States)

    ElBatal, Fatma H; Morsi, Reham M; Ouis, Mona A; Marzouk, Samir Y

    2010-11-01

    UV-visible spectroscopic measurements of Ni-doped sodium phosphate glasses were carried out before and after successive gamma irradiation. The undoped glass reveals strong UV absorption originating from trace iron impurities. NiO-doped glasses show characteristic absorption bands due mainly to octahedral coordination of Ni(2+) ions. Gamma irradiation produces induced bands generated from intrinsic defects and extrinsic defects. The changes in the spectroscopic data are discussed in relation to the structural evolution caused by the changes in composition and coordination state of nickel ions. The change in the growth behaviour of the induced bands is related to the annihilation or approach saturation of these characteristic induced bands. Raman and E.S.R. spectroscopic measurements confirm the presence of nickel as Ni(2+) ions in octahedral state. Copyright © 2010 Elsevier B.V. All rights reserved.

  6. Calcium phosphate glass-ceramics for bioactive coating on a β-titanium alloy

    International Nuclear Information System (INIS)

    Kasuga, T.; Nogami, M.; Niinomi, M.

    2003-01-01

    The formation of a porous coating is the decisive feature for the bio-compatibility of silica-free calcium phosphate glass ceramics on alloy surfaces like the β-Ti structured Ti-29Nb-13Ta-4.6Zr used in this work. The ceramic composition is highly important: 50CaO-40P 2 O 5 -7Na 2 O-3TiO 2 glass powder produces a pore-free coating unable to bind hydroxyapatite, whereas 60CaO-30P 2 O 5 -7Na 2 O-3TiO 2 glass incorporates pores from which a crystalline hydroxyapatite phase can grow over the surface from simulated body fluid (see Figure). (Abstract Copyright [2003], Wiley Periodicals, Inc.)

  7. Concentration dependent spectroscopic properties of Dy3+ ions doped boro-phosphate glasses

    Science.gov (United States)

    Mariyappan, M.; Marimuthu, K.

    2016-05-01

    Dy3+ ions doped boro-phosphate glasses have been synthesized by melt quenching method and characterized through FTIR, absorption and luminescence spectral measurements. The presence of various stretching and bending vibrations of different borate and phosphate groups were identified from the FTIR spectra. In order to examine the electronic band structure of the studied glasses, Optical energy gap (Eopt) and Urbach energy (ΔE) values were estimated from the absorption spectra. The Judd-Ofelt (JO) intensity parameters were calculated to examine the symmetry of the ligand environment around the Dy3+ ions site. The emission spectra exhibit two intense emission bands at around 482 nm (blue) and 574 nm (yellow) corresponding to the 4F9/2→6H15/2 and 4F9/2→6H13/2 transitions respectively. The emission spectra were characterized through Commission International d'Eclairage (CIE) 1931 chromaticity diagram to explore its suitability for WLED applications.

  8. Higher Fe{sup 2+}/total Fe ratio in iron doped phosphate glass melted by microwave heating

    Energy Technology Data Exchange (ETDEWEB)

    Mandal, Ashis K., E-mail: ashis@cgcri.res.in [CSIR-Central Glass and Ceramic Research Institute, 196 Raja S.C. Mullick Road, Kolkata 700032 (India); Sinha, Prasanta K. [CSIR-Central Glass and Ceramic Research Institute, 196 Raja S.C. Mullick Road, Kolkata 700032 (India); Das, Dipankar [UGC-DAE Consortium for Scientific Research, Kolkata 700098 (India); Guha, Chandan [Department of Chemical Engineering, Jadavpur University, Kolkata 700032 (India); Sen, Ranjan [CSIR-Central Glass and Ceramic Research Institute, 196 Raja S.C. Mullick Road, Kolkata 700032 (India)

    2015-03-15

    Highlights: • Iron doped phosphate glasses prepared using microwave heating and conventional heating under air and reducing atmosphere. • Presence of iron predominantly in the ferrous oxidation state in all the glasses. • Significant concentrations of iron in the ferrous oxidation state on both octahedral and tetrahedral sites in all the glasses. • Ratio of Fe{sup 2+} with total iron is found higher in microwave prepared glasses in comparison to conventional prepared glasses. - Abstract: Iron doped phosphate glasses containing P{sub 2}O{sub 5}–MgO–ZnO–B{sub 2}O{sub 3}–Al{sub 2}O{sub 3} were melted using conventional resistance heating and microwave heating in air and under reducing atmosphere. All the glasses were characterised by UV–Vis–NIR spectroscopy, Mössbauer spectroscopy, thermogravimetric analysis and wet colorimetry analysis. Mössbauer spectroscopy revealed presence of iron predominantly in the ferrous oxidation state on two different sites in all the glasses. The intensity of the ferrous absorption peaks in UV–Vis–NIR spectrum was found to be more in glasses prepared using microwave radiation compared to the glasses prepared in a resistance heating furnace. Thermogravimetric analysis showed increasing weight gain on heating under oxygen atmosphere for glass corroborating higher ratio of FeO/(FeO + Fe{sub 2}O{sub 3}) in glass melted by direct microwave heating. Wet chemical analysis also substantiated the finding of higher ratio Fe{sup +2}/ΣFe in microwave melted glasses. It was found that iron redox ratio was highest in the glasses prepared in a microwave furnace under reducing atmosphere.

  9. Investigations of the luminescence of phosphate glasses with respect to their application as solid dosemeters

    International Nuclear Information System (INIS)

    Regulla, D.F.

    1977-03-01

    A comprehensive presentation of the luminescent properties of phosphate glass is worked out. The extensive investigations show an essential enlargement of the knowledge on the luminescence of phosphate glass existing hitherto. These results form the basis for a detailed discussion of the luminescence mechanism. By applying additional results of measurements concerning optical and paramagnetic absorption, enabling the access to the atomic effect, propositions were developed for models of absorption, excitation and luminous centers relevant for dosimetry for which Ag ++ was found to be the constituent determining the centers. The interpretation of the luminescence phenomena within the frame of these models leads to considerable corrections on the existing concepts. At the same time the comparability of Ag-doped phosphate glasses and alkali halogenides is shown with respect to their luminescence behaviour, and with it an argument for the existence of crystal-like short-order regions in the amorphous glass is provided. This result serves as a basis for a discussion of the centers in the band model. Further investigations dealt with the quantities of influence for the practical application of the dosemeter. By interpretation of these results explanations are given for the effect of irradiation and evaluation temperatures, of LET, the dose, and UV light on the measuring signal. The phenomenon of 'pre-dose', for which especially surface effects have been detected as cause, is discussed under the aspect of a boundary layer theory. (orig./HP) [de

  10. Development of large scale production of Nd-doped phosphate glasses for megajoule-scale laser systems

    International Nuclear Information System (INIS)

    Ficini, G.; Campbell, J.H.

    1996-01-01

    Nd-doped phosphate glasses are the preferred gain medium for high-peak-power lasers used for Inertial Confinement Fusion research because they have excellent energy storage and extraction characteristics. In addition, these glasses can be manufactured defect-free in large sizes and at relatively low cost. To meet the requirements of the future mega-joule size lasers, advanced laser glass manufacturing methods are being developed that would enable laser glass to be continuously produced at the rate of several thousand large (790 x 440 x 44 mm 3 ) plates of glass per year. This represents more than a 10 to 100-fold improvement in the scale of the present manufacturing technology

  11. Fabrication of planar optical waveguides by 6.0 MeV silicon ion implantation in Nd-doped phosphate glasses

    Science.gov (United States)

    Shen, Xiao-Liang; Dai, Han-Qing; Zhang, Liao-Lin; Wang, Yue; Zhu, Qi-Feng; Guo, Hai-Tao; Li, Wei-Nan; Liu, Chun-Xiao

    2018-04-01

    We report the fabrication of a planar optical waveguide by silicon ion implantation into Nd-doped phosphate glass at an energy of 6.0 MeV and a dose of 5.0 × 1014 ions/cm2. The change in the surface morphology of the glass after the implantation can be clearly observed by scanning electron microscopy. The measurement of the dark mode spectrum of the waveguide is conducted using a prism coupler at 632.8 nm. The refractive index distribution of the waveguide is reconstructed by the reflectivity calculation method. The near-field optical intensity profile of the waveguide is measured using an end-face coupling system. The waveguide with good optical properties on the glass matrix may be valuable for the application of the Nd-doped phosphate glass in integrated optical devices.

  12. Mechanical, degradation and cytocompatibility properties of magnesium coated phosphate glass fibre reinforced polycaprolactone composites.

    Science.gov (United States)

    Liu, Xiaoling; Hasan, Muhammad S; Grant, David M; Harper, Lee T; Parsons, Andrew J; Palmer, Graham; Rudd, Chris D; Ahmed, Ifty

    2014-11-01

    Retention of mechanical properties of phosphate glass fibre reinforced degradable polyesters such as polycaprolactone and polylactic acid in aqueous media has been shown to be strongly influenced by the integrity of the fibre/polymer interface. A previous study utilising 'single fibre' fragmentation tests found that coating with magnesium improved the fibre and matrix interfacial shear strength. Therefore, the aim of this study was to investigate the effects of a magnesium coating on the manufacture and characterisation of a random chopped fibre reinforced polycaprolactone composite. Short chopped strand non-woven phosphate glass fibre mats were sputter coated with degradable magnesium to manufacture phosphate glass fibre/polycaprolactone composites. The degradation behaviour (water uptake, mass loss and pH change of the media) of these polycaprolactone composites as well as of pure polycaprolactone was investigated in phosphate buffered saline. The Mg coated fibre reinforced composites revealed less water uptake and mass loss during degradation compared to the non-coated composites. The cations released were also explored and a lower ion release profile for all three cations investigated (namely Na(+), Mg(2+) and Ca(2+)) was seen for the Mg coated composite samples. An increase of 17% in tensile strength and 47% in tensile modulus was obtained for the Mg coated composite samples. Both flexural and tensile properties were investigated and a higher retention of mechanical properties was obtained for the Mg coated fibre reinforced composite samples up to 10 days immersion in PBS. Cytocompatibility study showed both composite samples (coated and non-coated) had good cytocompatibility with human osteosarcoma cell line. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  13. Nonlinear optical characterization of phosphate glasses based on ZnO using the Z-scan technique

    International Nuclear Information System (INIS)

    Mojdehi Masoumeh Shokati; Yunus Wan Mahmood Mat; Talib Zainal Abidin; Tamchek, N.; Fhan Khor Shing

    2013-01-01

    The nonlinear optical properties of a phosphate vitreous system [(ZnO) x − (MgO) 30−x − (P 2 O 5 ) 70 ], where x = 8, 10, 15, 18, and 20 mol% synthesized through the melt-quenching technique have been investigated by using the Z-scan technique. In the experiment, a continuous-wave laser with a wavelength of 405 nm was utilized to determine the sign and value of the nonlinear refractive (NLR) index and the absorption coefficient with closed and opened apertures of the Z-scan setup. The NLR index was found to increase with the ZnO concentration in the glass samples by an order of 10 −10 cm 2 ·W −1 . The real and imaginary parts of the third-order nonlinear susceptibility were calculated by referring to the NLR index (n 2 ) and absorption coefficient (β) of the samples. The value of the third-order nonlinear susceptibility was presented by nonlinear refractive or absorptive behavior of phosphate glasses for proper utilization in nonlinear optical devices. Based on the measurement, the positive sign of the NLR index shows a self-focusing phenomenon. The figures of merit for each sample were calculated to judge the potential of phosphate glasses for application in optical switching

  14. Effect of MnO2 doped on physical, structure and optical properties of zinc silicate glasses from waste rice husk ash

    Directory of Open Access Journals (Sweden)

    Ali Jabbar Abed Al-Nidawi

    Full Text Available In this study, an investigation was conducted to explore and synthesize silicate (SiO2 glass from waste rice husk ash (RHA. MnO2 doped zinc silicate glasses with chemical formula [(ZnO55 + (WRHA45]100-X[MnO2]X, (where X = 0, 1, 3 and 5 wt% was prepared by conventional melt quenching technique. The glass samples were characterized using energy dispersive X-ray fluorescence (EDXRF, X-ray diffraction (XRD, field emission scanning electron microscopy (FESEM, Fourier transform infrared (FTIR spectroscopy, and ultraviolet–visible (UV–Vis spectroscopy. The results revealed that by increasing the concentration of MnO2, the color of glass samples changed from colorless to brown and the density of glass increased. XRD results showed that a broad halo peak which centered on the low angle (2θ = 30° indicated the amorphous nature of the glass. FTIR results showed basic structural units of Si-O-Si in non-bridging oxygen, Si-O and Mn-O in the glass network. FESEM result showed a decreasing porosity with an increasing MnO2 content, which was attributed to the Mn ions resort to occupy interstitial sites inside the pores of glass. Besides, the absorption intensity of glass increased and the band gap value decreased with increasing the MnO2 percentage. In this synthesized glass system of MnO2 doped zinc silicate glasses using RHA as a source of silica, the MnO2 affect most of the properties of the glass system under investigation. Keywords: Rice husk, Manganese dioxide, Glass, Zinc silicate, Sintering, Optical properties

  15. Effect of reducing conditions of synthesis on the character of the crystallization of phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Alekseeva, I.P.; Karapetyan, G.O.; Milyukov, E.M.; Rusan, V.V.

    1986-03-01

    The authors investigate the effect of synthesis conditions on the properties of phosphate glasses with a high concentration of rare-earth elements (REE) which are promising materials for quantum electronics. Particular attention was paid to the character of the crystallization of the glasses. A model glass of the composition La/sub 2/O/sub 3/ X 3P/sub 2/O/sub 5/ was studied which is transparent in the visible and near-IR regions of the spectrum and produced commercially.

  16. Calcium phosphate glass-ceramics for bioactive coating on a {beta}-titanium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Kasuga, T.; Nogami, M. [Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan); Niinomi, M. [Department of Production Systems Engineering, Toyohashi University of Technology, Tenpaku-cho, Toyohashi 441-8580 (Japan)

    2003-07-01

    The formation of a porous coating is the decisive feature for the bio-compatibility of silica-free calcium phosphate glass ceramics on alloy surfaces like the {beta}-Ti structured Ti-29Nb-13Ta-4.6Zr used in this work. The ceramic composition is highly important: 50CaO-40P{sub 2}O{sub 5}-7Na{sub 2}O-3TiO{sub 2} glass powder produces a pore-free coating unable to bind hydroxyapatite, whereas 60CaO-30P{sub 2}O{sub 5}-7Na{sub 2}O-3TiO{sub 2} glass incorporates pores from which a crystalline hydroxyapatite phase can grow over the surface from simulated body fluid (see Figure). (Abstract Copyright [2003], Wiley Periodicals, Inc.)

  17. Effect of radiative trapping on measurement of the spectroscopic properties of Yb sup 3 sup + :phosphate glasses

    CERN Document Server

    Dai Shi Xun; Wen Lei; Hu Li Li; Jiang Zhong Hon

    2003-01-01

    The effect of radiative trapping on measurement of the spectroscopic properties of Yb sup 3 sup + -doped phosphate glasses was investigated as a function of Yb sup 3 sup + concentration at different thicknesses. It was found that radiative trapping exists generally in Yb sup 3 sup + :phosphate glasses, even at low concentration. As a result, the measured lifetime of Yb sup 3 sup + in phosphate glasses is usually larger than the calculated one. The maximum discrepancies between them at high concentration are found to be <42%. The calculated lifetime should be used as a reference in determining the true value of the measured lifetime because of it being lengthened largely by radiative trapping. On the other hand, the shape of fluorescence spectrum exhibits remarkable changes due to the radiative trapping. What is more, the intensity increase of DELTA lambda sub e sub f sub f at high concentration is greater than that of low doping. The DELTA lambda sub e sub f sub f increases 36% from 53 to 72 nm with thickn...

  18. Fe++/Fe+++ concentration relationship and mechanical properties of phosphate glasses useful for wastes immobilization

    International Nuclear Information System (INIS)

    Garcia, D.A.; Prado, Miguel O.

    2007-01-01

    Under different melting conditions, glasses with different Fe(II)/Fe(III) concentration relationship were prepared within each type of glass 43Fe 2 O 3 -57P 2 O 5 and 33,33Fe 2 O 3 - 66,67P 2 O 5 . Using Moessbauer spectroscopy Fe(II)/Fe(III) concentration values were determined. Vickers and Knoop indentations were used for determining their hardness, toughness, Young modulus and brittleness. The same measurements were carried on some silicate and aluminosilicate glasses. Also Weibull statistics was done to determine the characteristics (Weibull modulus and and fracture probability) of glass fracture. We found that silicate glasses (SG) are harder than phosphate glasses (PG). Toughness values for PG, are in the same range than for SG, although for the same density exhibit larger values or smaller brittleness than silicate glasses. For one of the glasses it was found that the mechanical load P 0 needed for a fracture probability of 63% increases with the Fe(II) content. (author)

  19. Lead-iron phosophate glass

    International Nuclear Information System (INIS)

    Sales, B.C.; Boatner, L.A.

    1988-01-01

    The lead-iron phosphate nuclear waste glasses (LIPNWG) are the subject of the present chapter. They were discovered in 1984 while the authors were attempting to find a sintering aid for certain types of crystalline monazite ceramic high-level nuclear waste forms. In the present chapter, the term waste glass is synonymous with nuclear waste glass (NWG), and the acronym LIP is often used for lead-iron phosphate. Lead-iron phosphate glasses, like many of the previously studied phosphate glasses, are corrosion resistant in aqueous solutions at temperatures below 100 degrees C, and they can be melted and poured at temperatures that are relatively low in comparison with the processing temperatures required for current silicate glass compositions. Unlike the phosphate glasses investigated previously, however, LIPNWGs do not suffer from alteration due to devitrification during realistic and readily, achievable cooling periods. Additionally, lead-iron phosphate glass melts are not nearly as corrosive as the sodium phosphate melts investigated during the 1960s; and, therefore, they can be melted and processed using crucibles made from a variety of materials

  20. Determination of copper, manganese, nickel and zinc in different cigarette brands available in pakistan

    International Nuclear Information System (INIS)

    Siddiqui, I.; Hashmi, D.R.; Khan, F.A.

    2008-01-01

    Mean values of copper, manganese, nickel and zinc in different cigarette brands sold in Pakistan were found to be in the range of 8.61 to 94.67 macro g/g, 26.40 to 98.20 macro g/g, 0.61 to 8.58 macro g/g and 16.92 to 99.60 macro g/g, respectively, through Atomic Absorption Spectrophotometer (AAS). The results are discussed with reference to and in comparison with the mean average concentration of these elements reported in the cigarettes of other countries. (author)

  1. Effect of zinc-containing β-tricalcium phosphate nano particles injection on jawbone mineral density and mechanical strength of osteoporosis model rats

    International Nuclear Information System (INIS)

    Tokudome, Yoshihiro; Otsuka, Makoto; Ito, Atsuo

    2011-01-01

    Zinc-containing β-tricalcium phosphate (ZnTCP) nano particles were injected into zinc-deficient rats to promote osteogenesis. Sprague-Dawley (SD) rats (4 weeks old, average weight of 70 g) were divided into four groups: Normal rats (not ovariectomized (OVX)), Control rats (OVX), and OVX rats injected with a suspension of ZnTCP nano particles or ZnSO 4 . The ZnTCP contained 6.17% zinc. The suspensions (0.6 mg as a zinc volume/0.2 ml) were injected around the jaw bone once a week for 12 weeks. Local effects on the bone mineral content (BMC) of jawbone, and systemic effects on body weight, the BMC of both femurs determined by X-ray computed tomography, and bone mechanical strength (BMS) measured by the three-point bending method, were examined. The BMC of jaw bone was significantly higher in the ZnTCP-treated group than un-treated or ZnSO 4 -treated group. Body weight, the BMC of femurs, and BMS were also significantly higher in the ZnTCP treated-group. The zinc-containing β-tricalcium phosphate nano particles were effective at preventing bone loss induced by ovariectomy in rats and have potential uses for treating periodontitis. (author)

  2. Linear Optical Properties of Zinc Borotellurite Glass Doped with Lanthanum Oxide Nanoparticles for Optoelectronic and Photonic Application

    Directory of Open Access Journals (Sweden)

    Faznny Mohd Fudzi

    2017-01-01

    Full Text Available Enhancing the optical properties of glasses for the sake of optical application in various fields is an ongoing challenge in materials science and technology. Thus, the optical properties of zinc borotellurite glass doped with lanthanum oxide nanoparticles (La2O3 NPs with the chemical composition of {[(TeO20.7(B2O30.3]0.7(ZnO0.3}1−x (La2O3 NPsx, where x = 0.01, 0.02, 0.03, 0.04, and 0.05 molar fraction, have been investigated. Characterization techniques such as x-ray diffraction, Fourier Transform Infrared Spectroscopy, and Ultraviolet-Visible Spectroscopy are employed to yield the structural properties and optical parameter of the glass. The amorphous nature of the fabricated glasses is confirmed with the presence of a broad hump via XRD diffraction pattern. The decreasing amount of high polarizable nonbridging oxygen as the concentration of La2O3 NPs increases has contributed to the increasing trend of energy band gap in the range of 2.70 to 3.52 eV and decreasing value of refractive index between 2.34 and 2.48. The fabricated glasses that have a higher refractive index than the widely used fiber material, pure silica glass, indicate that zinc borotellurite glass doped with lanthanum nanoparticles is a promising material to be applied as optical fibers.

  3. Physical and optical properties of calcium sulfate ultra-phosphate glass-doped Er2O3

    Science.gov (United States)

    Aliyu, Aliyu Mohammed; Hussin, R.; Deraman, Karim; Ahmad, N. E.; Danmadami, Amina M.; Yamusa, Y. A.

    2018-03-01

    The influence of erbium on physical and optical properties of calcium sulfate ultra-phosphate glass was investigated using conventional melt quench process. Selected samples of composition 20CaSO4 (80 - x) P2O5- xEr2O3 with 0.1 ≤x ≤ 0.9 mol.% were prepared and assessed. X-ray diffraction (XRD) techniques were used to confirm the amorphous nature of the said samples. The structural units of phosphate-based glass were assessed from Raman spectra as ultra-(Q3), meta-(Q2), pyro-(Q1) and orthophosphate (Q0) units. Depolymerization process of the glasses was testified for higher calcium oxide content and UV-visible for optical measurement. Thermal analysis have been investigated by means of thermogravimetric analysis. The results show the decomposition of materials in the temperature range of 25∘C-1000∘C. Er3+ absorption spectra were measured in the range of 400-1800nm. PL measurement was carried out in order to obtain the excitation and emission spectra of the samples. The emission spectra excited at 779nm comprises of 518nm, 550nm and 649nm of transition 4F9/2, 4S3/2 and 2H11/2 excited states to 4I15/2 ground state. In physical properties, the density calculated using Archimedes method is inversely proportional to molar volume with increase in Er3+ ions. Optical bandgap (Eg) were determined using Tauc’s plots for direct transitions where Eg (direct) decreases with increase in erbium content. The refractive index increases with decreasing molar volume; this may have a tendency for larger optical bandgap. The result obtained from the glass matrix indicates that erbium oxide-doped calcium sulfate ultra-phosphate may give important information for wider development of functional glasses.

  4. Development of phosphate glass microspheres containing holmium for selective internal radiotherapy

    International Nuclear Information System (INIS)

    Barros Filho, Eraldo Cordeiro

    2016-01-01

    The selective internal radiotherapy is an alternative for some kinds of cancer as the hepatocellular carcinoma (HCC) or primary liver cancer treatment. In this treatment, glass or polymer microspheres containing radionuclides inside their structure are introduced in the liver through hepatic artery and trapped at the arterioles that feed the tumor. In this work, the development of phosphate glasses containing holmium for production of microspheres and their application in Brazil are proposed. The developed glasses presented suitable chemical durability, density of 2,7(3) g/cm 3 , high thermal stability and the impurities contained therein do not preclude the treatment. The microspheres were produced by the flame method and the gravitational fall method, and were characterized by means of several techniques to evaluate shape, average particle size, activity and biocompatibility suitable for selective internal radiotherapy. Based in the main results, the submission to in vivo tests is proposed. (author)

  5. Shear-peel strength comparison of orthodontic band cements including novel calcium silicate

    DEFF Research Database (Denmark)

    Leo, Mariantonietta; Løvschall, Henrik

    calcium silicate with fluoride and fast-setting, Glass ionomer, and Zinc phosphate cement, used for luting of orthodontic bands on molars kept one month in phosphate buffering solution (PBS). Materials and methods: The roots of 35 extracted human molars were embedded in acryl. Three groups were allocated....... An orthodontic band (AO) was fitted on the free crown. Each group of the teeth (n>10) was cemented with novel calcium silicate (Protooth), Glass ionomer (Orthocem), or Zinc phosphate (DeTrey Zinc). The cements were mixed according to the manufacturers instructions. Samples were stored at 37ºC in humid chamber...... Silicate (Protooth) and Zinc phosphate cement (DeTrey Zinc) were significantly higher than Glass ionomer cement (Orthocem) when looking for the force (N, p

  6. Effect of composition and temperature on the second harmonic generation in silver phosphate glasses

    Science.gov (United States)

    Konidakis, I.; Psilodimitrakopoulos, S.; Kosma, K.; Lemonis, A.; Stratakis, E.

    2018-01-01

    We herein employ nonlinear laser imaging microscopy to explicitly study the dynamics of second harmonic generation (SHG) in silver iodide phosphate glasses. While glasses of this family have gained extensive scientific attention over the years due to their superior conducting properties, considerably less attention has been paid to their unique nonlinear optical characteristics. In the present study, firstly, it is demonstrated that SHG signal intensity is enhanced upon increasing silver content due to the random formation of silver microstructures within the glass network. Secondly, the SHG temperature dynamics were explored near the glass transition temperature (Tg) regime, where significant glass relaxation phenomena occur. It is found that heating towards the Tg improves the SHG efficiency, whereas above Tg, the capacity of glasses to generate second harmonic radiation is drastically suppressed. The novel findings of this work are considered important in terms of the potential employment of these glasses for the realization of advanced photonic applications like optical-switches and wavelength conversion devices.

  7. Concentration dependent spectroscopic properties of Dy{sup 3+} ions doped boro-phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Mariyappan, M.; Marimuthu, K., E-mail: mari-ram2000@yahoo.com [Department of Physics, Gandhigram Rural Institute - Deemed University, Gandhigram – 624 302 (India)

    2016-05-23

    Dy{sup 3+} ions doped boro-phosphate glasses have been synthesized by melt quenching method and characterized through FTIR, absorption and luminescence spectral measurements. The presence of various stretching and bending vibrations of different borate and phosphate groups were identified from the FTIR spectra. In order to examine the electronic band structure of the studied glasses, Optical energy gap (E{sub opt}) and Urbach energy (ΔE) values were estimated from the absorption spectra. The Judd-Ofelt (JO) intensity parameters were calculated to examine the symmetry of the ligand environment around the Dy{sup 3+} ions site. The emission spectra exhibit two intense emission bands at around 482 nm (blue) and 574 nm (yellow) corresponding to the {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} transitions respectively. The emission spectra were characterized through Commission International d’Eclairage (CIE) 1931 chromaticity diagram to explore its suitability for WLED applications.

  8. Optical basicity and electronic polarizability of zinc borotellurite glass doped La3+ ions

    Directory of Open Access Journals (Sweden)

    M.K. Halimah

    Full Text Available Zinc borotellurite glasses doped with lanthanum oxide were successfully prepared through melt-quenching technique. The amorphous nature of the glass system was validated by the presence of a broad hump in the XRD result. The refractive index of the prepared glass samples was calculated by using the equation proposed by Dimitrov and Sakka. The theoretical value of molar refraction, electronic polarizability, oxide ion polarizability and metallization criterion were calculated by using Lorentz-Lorenz equation. Meanwhile, expression proposed by Duffy and Ingram for the theoretical value of optical basicity of multi-component glasses were applied to obtain energy band gap based optical basicity and refractive index based optical basicity. The optical basicity of prepared glasses decreased with the increasing concentration of lanthanum oxide. Metallization criterion on the basis of refractive index showed an increasing trend while energy band gap based metallization criterion showed a decreasing trend. The small metallization criterion values of the glass samples represent that the width of the conduction band becomes larger which increase the tendency for metallization of the glasses. The results obtained indicates that the fabricated glasses have high potential to be applied on optical limiting devices in photonic field. Keywords: Borotellurite glasses, Refractive index, Electronic polarizability, Oxide ion polarizability, Optical basicity, Metallization criterion

  9. Electrical conductivity and modulus formulation in zinc modified bismuth boro-tellurite glasses

    Science.gov (United States)

    Dhankhar, Sunil; Kundu, R. S.; Dult, Meenakshi; Murugavel, S.; Punia, R.; Kishore, N.

    2016-09-01

    The ac conductivity of zinc modified tellurium based quaternary glasses having composition 60 TeO2-10 B2O3-(30 - x) Bi2O3-x ZnO; x = 10, 15, 20, 25 and 30 has been investigated in the frequency range 10-1-105 Hz and in temperature range 483-593 K. Frequency and temperature dependent ac conductivity found to obey Jonscher power law modified by Almond-West. DC conductivity, crossover frequency and frequency exponent have been estimated from the fitting of the experimental data of conductivity with Jonscher power law modified by Almond-West. The ac conductivity and its frequency exponent have been analyzed by various theoretical models. In presently studied glasses ac conduction takes place via tunneling of overlapping large polaron tunneling. Activation energy is found to be increased with increase in zinc content and dc conduction takes place via variable range hopping proposed by Mott with some modification suggested by Punia et al. The value of the stretched exponent ( β) obtained by fitting of M^' ' }} reveals the presence of non-Debye type relaxation. Scaling spectra of ac conductivity and electric modulus collapse into a single master curve for all compositions and temperatures, reveals the presence of composition and temperature independent conduction and relaxation process in these glasses. Activation energy of conduction ( W) and electric modulus ( E R ) are nearly equal, indicating that polaron have to overcome the same energy barrier during conduction as well as relaxation processes.

  10. Novel adaptations to zinc-silicate glass polyalkenoate cements: the unexpected influences of germanium based glasses on handling characteristics and mechanical properties.

    Science.gov (United States)

    Dickey, B T; Kehoe, S; Boyd, D

    2013-07-01

    Aluminum-free glass polyalkenoate cements (GPC) have been hindered for use as injectable bone cements by their inability to balance handling characteristics with mechanical integrity. Currently, zinc-based, aluminum-free GPCs demonstrate compression strengths in excess of 60MPa, but set in c. 1-2 min. Previous efforts to extend the setting reaction have remained clinically insufficient and are typically accompanied by a significant drop in strength. This work synthesized novel glasses based on a zinc silicate composition with the inclusion of GeO2, ZrO2, and Na2O, and evaluated the setting reaction and mechanical properties of the resultant GPCs. Germanium based GPCs were found to have working times between 5 and 10 min, setting times between 14 and 36 min, and compression strengths in excess of 30 MPa for the first 30 days. The results of this investigation have shown that the inclusion of GeO2, ZrO2, and Na2O into the glass network have produced, for the first time, an aluminum-free GPC that is clinically viable as injectable bone cements with regards to handling characteristics and mechanical properties. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  11. 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.

  12. An alternative host matrix based on iron phosphate glasses for the vitrification of specialized nuclear waste forms. Annual progress report, September 15, 1996 - September 14, 1997

    International Nuclear Information System (INIS)

    Day, D.E.; Marasinghe, K.; Ray, C.S.

    1997-01-01

    'Objectives of this project are to: (1) investigate the glass composition and processing conditions that yield optimum properties for iron phosphate glasses for vitrifying radioactive waste, (2) determine the atomic structure of iron phosphate glasses and the structure-property relationships, (3) determine how the physical and structural properties of iron phosphate glasses are affected by the addition of simulated high level nuclear waste components, and (4) investigate the process and products of devitrification of iron phosphate waste forms. The glass forming ability of about 125 iron phosphate melts has been investigated in different oxidizing to reducing atmospheres using various iron oxide raw materials such as Fe 2 O 3 , FeO, Fe 3 O 4 , and FeC 2 O 4 2H 2 O. The chemical durability, redox equilibria between Fe(II) and Fe(III), crystallization behavior and structural features for these glasses and their crystalline forms have been investigated using a variety of techniques including Mossbauer spectroscopy, X-ray absorption spectroscopy (XAS), X-ray photoelectron spectroscopy (XPS), Extended x-ray absorption fine structure (EXAFS) and X-ray absorption near edge structure (XANES) analysis, differential thermal and thermogravimetric analysis (DTA/TGA), and X-ray and neutron diffraction.'

  13. Raman and DSC studies of fragility in tellurium-zinc oxide glass formers

    International Nuclear Information System (INIS)

    Stavrou, Elissaios; Kripotou, Sotiria; Raptis, Constantine; Turrell, Sylvia; Syassen, Karl

    2011-01-01

    Raman scattering and differential scanning calorimetry (DSC) measurements have been carried out in four mixed (TeO 2 ) 1-x (ZnO) x (x = 0.1, 0.2, 0.3, 0.4) glasses at high temperatures (Raman and DSC through the glass transition) and high pressures (Raman) with the aim of determining the fragility of these glass forming oxides. Four different criteria, corresponding to four parameters, were applied to assess the fragility of the glasses. From the DSC studies, we have obtained the fragility parameter m which corresponds to the slopes of Arrhenius (lnQ vs. 1/T g , were Q is the heating rate) plots, and the glass transition width ΔT g . Also, from the low-frequency Raman scattering, and in particular the boson peak intensity of the glasses at T g , we have estimated the fragility ratio r R (T g ) = I min /I max whose value serves as another (empirical) fragility criterion. Finally, from high pressure Raman measurements on the glasses, we have estimated the Grueneisen parameter γ T for each glass, which constitutes the fourth fragility parameter adopted in this work. Considering the four parameters ΔT g , m, r (T g ) and γ T and the generally accepted (empirical) fragility criteria, we conclude that the mixed tellurium-zinc oxides constitute strong-to-intermediate glass formers (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  14. Color tunability of Sm{sup 3+} doped antimony–phosphate glass phosphors showing broadband fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, P. [School of Textile and Material Engineering, Dalian Polytechnic University, Dalian 116034 (China); Zhang, J.J., E-mail: zhangjj@dlpu.edu.cn [School of Textile and Material Engineering, Dalian Polytechnic University, Dalian 116034 (China); Shen, L.F. [Department of Electronic Engineering and State Key Laboratory of Millimeter Waves, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Wang, Z.Q. [School of Textile and Material Engineering, Dalian Polytechnic University, Dalian 116034 (China); Pun, E.Y.B. [Department of Electronic Engineering and State Key Laboratory of Millimeter Waves, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Lin, H., E-mail: lhai8686@yahoo.com [School of Textile and Material Engineering, Dalian Polytechnic University, Dalian 116034 (China); Department of Electronic Engineering and State Key Laboratory of Millimeter Waves, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China)

    2016-10-15

    Sm{sup 3+} doped multicomponent antimony phosphate (MSP) luminescent glasses were prepared and tunable white fluorescence has been investigated. Broad visible emission depending on excitation wavelength is validated to be dominated by discrepant Sb{sup 3+} emitting centers. Group of narrow emissions from Sm{sup 3+} is beneficial to adding yellow and red components in Sm{sup 3+} doped MSP glasses, which is strengthened by effective energy transfer from Sb{sup 3+} to Sm{sup 3+}. Excitation wavelength selection and Sm{sup 3+} concentration adjustment are two feasible routes to optimize luminescence color in Sm{sup 3+} doped MSP glasses and the color tunability of fluorescence indicates that amorphous Sm{sup 3+} doped MSP glass phosphors possess potential for ideal white light devices.

  15. Investigation of structural transformations in surface layer of phosphate glasses incorporating radiactive wastes

    International Nuclear Information System (INIS)

    Aloj, A.S.; Kolycheva, T.I.; Trofimenko, A.V.; Shashukov, E.A.

    1985-01-01

    The objective of the paper was to clarify possibilities of detection of structural transformations initial stages on the surface of phosphate glasses using the method of infrared reflection spectroscopy. Phase composition of crystalline compounds formed in surface glass layer is determined by the method of X-ray diffraction. All experiments were performed using sodium alumophosphate glass comprising the model mixture of fission product of the following compostion (mass%): Na 2 O-22.0, Al 2 O 3 -14.0, P 2 O 5 -50.0, Fe 2 O 3 -3.5, Cs 2 O-3.5, SrO-3.0, Ln 2 O 3 -4.0, where Ln 2 O 3 is a mixture of cerium, lanthanum and europium oxides. Sample preparation were carried out by molten glass deposition on platinum forms 15mm in diameter and 4mm thick. Glasses were treated within the 600-400deg.C temperature range. Fixing of processes accompanied by structural transformations was accomplished the method of rapid cooling. It has been shown that phase transformations, taking place in investigated phosphate glasses under the action of heat, result in deterioration of chemical properties. Analysis of IR spectra has revealed that emergence of structural transformations in surface layer of investigated glasses results in variation of a ratio of 1060 and 1140cm - 1 reflection band intensities. Experimental dependences of the time of beginning of variation of 1060 and 1140cm - 1 bands relative intensity on temperature are presented. Insemilogarithmic coordinates this dependence has a straight line form within the 600-400 deg C temperature range and is desc ribed by the following formular: lg r=-7.41+5.70x10 3 x1/T, where r is the time of process beginning, h. Extrapolation of established to the region of low temperature is shown. Competence of such extrapolation may be confirmed in the course of further experiments

  16. Iron Phosphate Glass for Vitrifying Hanford AZ102 LAW in Joule Heated and Cold Crucible Induction Melters - 12240

    Energy Technology Data Exchange (ETDEWEB)

    Day, Delbert E.; Brow, Richard K.; Ray, Chandra S.; Reis, Signo T. [Missouri University of Science and Technology, 1870 Miner Circle, Rolla, MO 65409 (United States); Kim, Cheol-Woon [MO-SCI Corporation, 4040 HyPoint North, Rolla, MO 65401 (United States); Vienna, John D.; Sevigny, Gary [Pacific North West National Laboratory, Battelle Blvd., Richland, WA 99352 (United States); Peeler, David; Johnson, Fabienne C.; Hansen, Eric K. [Savannah River National Laboratory, Savannah River Site, 999-W, Aiken, SC 29803 (United States); Soelberg, Nick [Idaho National Laboratory, 2525 Fremont Avenue, Idaho Falls, ID 83415 (United States); Pegg, Ian L.; Gan, Hao [Catholic University of America, 620 Michigan Avenue, N.E., Washington, DC 20064 (United States)

    2012-07-01

    An iron phosphate composition for vitrifying a high sulfate (∼17 wt%) and high alkali (∼80 wt%) Hanford low activity waste (LAW), known as AZ-102 LAW, has been developed for processing in a Joule Heated Melter (JHM) or a Cold Crucible Induction Melter (CCIM). This composition produced a glass waste form, designated as MS26AZ102F-2, with a waste loading of 26 wt% of the AZ-102 which corresponded to a total alkali and sulfate (represented as SO{sub 3}) content of 21 and 4.4 wt%, respectively. A slurry (7 M Na{sup +}) of MS26AZ102F-2 simulant was melted continuously at temperatures between 1030 and 1090 deg. C for 10 days in a small JHM at PNNL and for 70 hours in a CCIM at INL. The as-cast glasses produced in both melters and in trial laboratory experiments along with their canister centerline cooled (CCC) counterparts met the requirements for the Product Consistency Test (PCT) and the Vapor Hydration Test (VHT) responses in the Hanford Tank Waste Treatment and Immobilization Plant (WTP) Contract. These glass waste forms retained up to 77 % of the SO{sub 3} (3.3 wt%), 100% of the Cesium, and 33 to 44% of the rhenium (used as a surrogate for Tc) all of which either exceeded or were comparable to the retention limit for these species in borosilicate glass nuclear waste form. Analyses of commercial K-3 refractory lining and the Inconel 693 metal electrodes used in JHM indicated only minimum corrosion of these components by the iron phosphate glass. This is the first time that an iron phosphate composition was melted continuously in a slurry fed JHM and in the US, thereby, demonstrating that iron phosphate glasses can be used as alternative hosts for vitrifying nuclear waste. The following conclusions are drawn from the results of the present work. (1) An iron phosphate composition, designated as MS26AZ102F-2, containing 26 wt% of the simulated high sulfate (17 wt%), high alkali (80 wt%) Hanford AZ-102 LAW meets all the criteria for processing in a JHM and CCIM. This

  17. The structure of phosphate glass biomaterials from neutron diffraction and 31P nuclear magnetic resonance data

    International Nuclear Information System (INIS)

    Pickup, D M; Ahmed, I; Guerry, P; Knowles, J C; Smith, M E; Newport, R J

    2007-01-01

    Neutron diffraction and 31 P nuclear magnetic resonance spectroscopy were used to probe the structure of phosphate glass biomaterials of general composition (CaO) 0.5-x (Na 2 O) x (P 2 O 5 ) 0.5 (x = 0, 0.1 and 0.5). The results suggest that all three glasses have structures based on chains of Q 2 phosphate groups. Clear structural differences are observed between the glasses containing Na 2 O and CaO. The P-O bonds to bridging and non-bridging oxygens are less well resolved in the neutron data from the samples containing CaO, suggesting a change in the nature of the bonding as the field strength of the cation increases Na + → Ca 2+ . In the (CaO) 0.5 (P 2 O 5 ) 0.5 glass most of the Ca 2+ ions are present in isolated CaO x polyhedra whereas in the (Na 2 O) 0.5 (P 2 O 5 ) 0.5 glass the NaO x polyhedra share edges leading to a Na-Na correlation. The results of the structural study are related to the properties of the (CaO) 0.4 (Na 2 O) 0.1 (P 2 O 5 ) 0.5 biomaterial

  18. Optical properties of zinc borotellurite glass doped with trivalent dysprosium ion

    Science.gov (United States)

    Ami Hazlin, M. N.; Halimah, M. K.; Muhammad, F. D.; Faznny, M. F.

    2017-04-01

    The zinc borotellurite doped with dysprosium oxide glass samples with chemical formula {[(TeO2) 0 . 7(B2O3) 0 . 3 ] 0 . 7(ZnO) 0 . 3 } 1 - x(Dy2O3)x (where x=0.01, 0.02, 0.03, 0.04 and 0.05 M fraction) were prepared by using conventional melt quenching technique. The structural and optical properties of the proposed glass systems were characterized by using X-ray diffraction (XRD) spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, and UV-VIS spectroscopy. The amorphous nature of the glass systems is confirmed by using XRD technique. The infrared spectra of the glass systems indicate three obvious absorption bands which are assigned to BO3 and TeO4 vibrational groups. Based on the absorption spectra obtained, the direct and indirect optical band gaps, as well as the Urbach energy were calculated. It is observed that both the direct and indirect optical band gaps increase with the concentration of Dy3+ ions. On the other hand, the Urbach energy is observed to decrease as the concentration of Dy3+ ions increases.

  19. Microstructure and spectroscopic investigations of calcium zinc bismuth phosphate glass ceramics doped with manganese ions

    Science.gov (United States)

    Suneel Kumar, A.; Sambasiva Rao, M. V.; Chinna Ram, G.; Krishna Rao, D.

    2018-01-01

    Multi-component 10CaF2-20ZnO-(15 - x)Bi2O3-55P2O5:xMnO (0 ≤ x ≤ 2.5) glass ceramics were synthesised by melt quenching technique and heat treatment. The prepared glass ceramics were characterised by XRD, DTA, EDS and SEM. Spectroscopic studies such as optical absorption, EPR, FTIR and Raman were also carried out on these glass ceramics. The XRD and SEM studies have indicated that ceramic samples contain well defined and randomly distributed grains of different crystalline phases. The observed increase of enthalpy from DTA patterns up to 1 mol% of MnO indicates that the crystallisation starts initially from the surface of the material then gradually it is extended to the volume of the material and this influence is meagre at higher concentrations of MnO. The absorption spectra of manganese doped glass ceramics have exhibited two types of conventional bands; one due to Mn2+ ions and other due to Mn3+ ions. The EPR spectra of MnO doped glass ceramics showed a resonance signal around g2 = 2.023 with a six line hyperfine structure and another signal at about g1 = 4.314. The relative intensity and half-width of these two signals are observed to increase with the increase in the concentration of manganese ions up to 1 mol% beyond this concentration it is found to decrease. Such observation indicates the conversion of part of Mn2+ ions into Mn3+ ions in the glass ceramic matrix. The observed increase in the intensity of symmetrical structural units at the expense of asymmetrical structural units from the FTIR and Raman spectra at higher concentration of MnO indicating that Mn2+ ions occupy the network forming positions in the glass ceramic structure.

  20. Continuous monitoring of the zinc-phosphate acid-base cement setting reaction by proton nuclear magnetic relaxation

    International Nuclear Information System (INIS)

    Apih, T.; Lebar, A.; Pawlig, O.; Trettin, R.

    2001-01-01

    Proton nuclear magnetic relaxation is a well-established technique for continuous and non destructive monitoring of hydration of conventional Portland building cements. Here, we demonstrate the feasibility of nuclear magnetic resonance (NMR) monitoring of the setting reaction of zinc-phosphate acid-base dental cements, which harden in minutes as compared to days, as in the case of Portland cements. We compare the setting of cement powder (mainly, zinc oxide) prepared with clinically used aluminum-modified orthophosphoric acid solution with the setting of a model system where cement powder is mixed with pure orthophosphoric acid solution. In contrast to previously published NMR studies of setting Portland cements, where a decrease of spin-lattice relaxation time is attributed to enhanced relaxation at the growing internal surface, spin-lattice relaxation time T 1 increases during the set of clinically used zinc-phosphate cement. Comparison of these results with a detailed study of diffusion, viscosity, and magnetic-field dispersion of T 1 in pure and aluminum-modified orthophosphoric acid demonstrates that the increase of T 1 in the setting cement is connected with the increase of molecular mobility in the residual phosphoric acid solution. Although not taken into account so far, such effects may also significantly influence the relaxation times in setting Portland cements, particularly when admixtures with an effect on water viscosity are used. [copyright] 2001 American Institute of Physics

  1. Quantum and dielectric confinements of sub-10 nm gold in dichroic phosphate glass nanocomposites

    International Nuclear Information System (INIS)

    Singh, Shiv Prakash; Nath, Mithun; Karmakar, Basudeb

    2014-01-01

    Blue shifts of the surface plasmon resonance band of sub-10 nm gold in dichroic phosphate glass nanocomposites are observed with increase in both size of gold nanoparticles and refractive index of the medium, which are contrary to the common trends. These phenomena have been enlightened with the electrodynamics theories (Mie and Drude models) and happened due to quantum and dielectric confinements. Nanocomposites have been synthesized by in-situ thermochemical reduction technique in reducing phosphate glass matrices. The plasmon bands are characterized by the UV–vis spectrophotometer, and shape and size of the nanogold by the transmission electron microscopy. All the nanocomposites are dichroic in nature. - Highlights: • We fabricated Au 0 embedded nanocomposites in P 2 O 5 –SnO–ZnO glass matrix. • Au 0 synthesized by a single step in-situ thermochemical reduction technique. • We have reported the blue shifts of the SPR band of sub-10 nm Au 0 NPs. • The optical property has been explained on the basis of electrodynamics theories

  2. Health risk assessment of heavy metals (cadmium, nickel, lead and zinc in withdrawed parsley vegetable from some farms in Hamedan city

    Directory of Open Access Journals (Sweden)

    M Cheraghi

    2014-11-01

    Results: Average concentration of cadmium, nickel, lead and zinc in parsley vegetable is in the order of 1/14, 2/56, 16/65 and 25/23 mg/kg and average concentration of this metals in soil is in the order of 0/23, 23/51, 20/85 and 57/5 mg/kg. Results of this study showed that average concentration of Cadmium and Leadin parsley is above WHO/FAO whereas average concentration of Nickel and Zink in parsleywas assessed less than WHO/FAO. Also the average concentration of every four metals in soil of farms was less than WHO/FAO levels.On the other hand the amount of risk and health index (HRI in parsley for lead metal was above 1 and for cadmium, nickel and zinc metals was less than 1. Conclusion: According to the studing results, cultivated parsley in this area was polluted to the heavy metalsCadmium and Lead, and the results indicates the very easy transferring of this metals from soil to parsley that was not healthy for human daily consumption and risk and health index (HRI that was above 1 for lead metal shows the hygienic potential risk of this metal in relation to the polluted parsley consumption in human daily alimentary diet.

  3. Effect of zinc from zinc sulfate on trace mineral concentrations of milk ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-11-16

    Nov 16, 2009 ... It suggests that supplementation of ewes diet with zinc sulfate could be an effective way to increase zinc ... alkaline phosphates activity. Zinc supplements were .... Similar results have been reported previously when dairy cows.

  4. Spectroscopic investigation of zinc tellurite glasses doped with Yb3 + and Er3 + ions

    Science.gov (United States)

    Bilir, Gökhan; Kaya, Ayfer; Cinkaya, Hatun; Eryürek, Gönül

    2016-08-01

    This paper presents a detailed spectroscopic investigation of zinc tellurite glasses with the compositions (0.80 - x - y) TeO2 + (0.20) ZnO + xEr2O3 + yYb2O3 (x = 0, y = 0; x = 0.004, y = 0; x = 0, y = 0.05 and x = 0.004, y = 0.05 per moles). The samples were synthesized by the conventional melt quenching method. The optical absorption and emission measurements were conducted at room temperature to determine the spectral properties of lanthanides doped zinc tellurite glasses and, to study the energy transfer processes between dopant lanthanide ions. The band gap energies for both direct and indirect possible transitions and the Urbach energies were measured from the absorption spectra. The absorption spectra of the samples were analyzed by using the Judd-Ofelt approach. The effect of the ytterbium ions on the emission properties of erbium ions was investigated and the energy transfer processes between dopant ions were studied by measuring the up-conversion emission properties of the materials. The color quality parameters of obtained visible up-conversion emission were also determined as well as possibility of using the Er3 + glasses as erbium doped fiber amplifiers at 1.55 μm in infrared emission region.

  5. Effect of Erbium Nanoparticles on Optical Properties of Zinc Borotellurite Glass System

    Directory of Open Access Journals (Sweden)

    Azlan Muhammad Noorazlan

    2013-01-01

    Full Text Available Erbium nanoparticles (NPs doped zinc borotellurite glasses have been prepared by conventional melt-quenching technique with the chemical composition {[(TeO20.70(B2O30.30]1-x(ZnOx}1-y(Er3O2y (where y=0.005,0.01,0.02,0.03,0.04,0.05. The structural properties of the prepared glasses were determined via X-ray diffraction (XRD analysis and FTIR analysis. It was confirmed that the prepared glasses are amorphous. The bonding parameters of the glasses were analyzed by using FTIR analysis and were confirmed to be ionic in nature. The refractive index increases as the content of erbium NPs increases. The optical absorption spectra revealed that fundamental absorption edge shifts to longer wavelength as the content of erbium NPs increases. The value of band gap had been calculated and shown to be decreased with an increase content of erbium NPs. The Urbach energy was shown to be linearly increased with an increase content of erbium NPs oxides.

  6. Characterization of radiative properties of Nd{sub 2}O{sub 3} doped phosphate and silicate glasses for solid state laser

    Energy Technology Data Exchange (ETDEWEB)

    Nandi, P., E-mail: pnandi@barc.gov.in; Shukla, R., E-mail: pnandi@barc.gov.in; Goswami, M., E-mail: pnandi@barc.gov.in [Glass and Advanced Materials Division, Bhabha Atomic Research Centre, Mumbai-400085 (India); Sudarsan, V. [Chemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai-400085 (India)

    2014-04-24

    Nd{sub 2}O{sub 3} doped calcium aluminium phosphate and calcium aluminium silicate glasses prepared to compare their absorption and emission properties. Radiative lifetime of the excited state {sup 4}F{sub 3/2} derived by Judd-Ofelt theory applied to the absorption spectra. Using the photoluminescence spectrometer the steady state emission and relaxation time from excited energy level recorded under green light excitation. Phosphate glass has higher emission cross-section, higher radiative lifetime but less quantum efficiency due to non-radiative quenching through hydroxyl ions compared to silicate glass for Nd{sup 3+}:{sup 4}F{sub 3/2}→{sup 4}I{sub 9/2} emission.

  7. Erbium-doped phosphate glass waveguide on silicon with 4.1 dB/cm gain at 1.535 µm

    Science.gov (United States)

    Yan, Y. C.; Faber, A. J.; de Waal, H.; Kik, P. G.; Polman, A.

    1997-11-01

    Erbium-doped multicomponent phosphate glass waveguides were deposited by rf sputtering techniques. The Er concentration was 5.3×1020cm-3. By pumping the waveguide at 980 nm with a power of ˜21 mW, a net optical gain of 4.1 dB at 1.535 μm was achieved. This high gain per unit length at low pump power could be achieved because the Er-Er cooperative upconversion interactions in this heavily Er-doped phosphate glass are very weak [the upconversion coefficient is (2.0±0.5)×10-18 cm3/s], presumably due to the homogeneous distribution of Er in the glass and due to the high optical mode confinement in the waveguide which leads to high pump power density at low pump power.

  8. Investigating the use of coupling agents to improve the interfacial properties between a resorbable phosphate glass and polylactic acid matrix.

    Science.gov (United States)

    Hasan, Muhammad Sami; Ahmed, Ifty; Parsons, Andrew J; Rudd, Chris D; Walker, Gavin S; Scotchford, Colin A

    2013-09-01

    Eight different chemicals were investigated as potential candidate coupling agents for phosphate glass fibre reinforced polylactic acid composites. Evidence of reaction of the coupling agents with phosphate glass and their effect on surface wettability and glass degradation were studied along with their principle role of improving the interface between glass reinforcement and polymer matrix. It was found that, with an optimal amount of coupling agent on the surface of the glass/polymer, interfacial shear strength improved by a factor of 5. Evidence of covalent bonding between agent and glass was found for three of the coupling agents investigated, namely: 3-aminopropyltriethoxysilane; etidronic acid and hexamethylene diisocyanate. These three coupling agents also improved the interfacial shear strength and increased the hydrophobicity of the glass surface. It is expected that this would provide an improvement in the macroscopic properties of full-scale composites fabricated from the same materials which may also help to retain these properties for the desired length of time by retarding the breakdown of the fibre/matrix interface within these composites.

  9. Development, characterisation and biocompatibility testing of a cobalt-containing titanium phosphate-based glass for engineering of vascularized hard tissues

    Energy Technology Data Exchange (ETDEWEB)

    Lee, In-Ho [Department of Nanobiomedical Science and WCU Research Center of Nanobiomedical Science, Dankook University, Chungnam 330-714 (Korea, Republic of); Yu, Hye-sun [Department of Nanobiomedical Science and WCU Research Center of Nanobiomedical Science, Dankook University, Chungnam 330-714 (Korea, Republic of); Department of Biochemical Engineering, University College London, Torrington Place, London, WC1E 7JE (United Kingdom); Lakhkar, Nilay J. [Division of Biomaterials and Tissue Engineering, Eastman Dental Institute, University College London, 256 Gray' s Inn Road, London WC1X 8LD (United Kingdom); Kim, Hae-Won [Department of Nanobiomedical Science and WCU Research Center of Nanobiomedical Science, Dankook University, Chungnam 330-714 (Korea, Republic of); Institute of Tissue Regeneration Engineering (ITREN), Dankook University, Cheonan 330-714 (Korea, Republic of); Department of Biomaterials Science, College of Dentistry, Dankook University, Cheonan 330-714 (Korea, Republic of); Gong, Myoung-Seon [Department of Nanobiomedical Science and WCU Research Center of Nanobiomedical Science, Dankook University, Chungnam 330-714 (Korea, Republic of); Institute of Tissue Regeneration Engineering (ITREN), Dankook University, Cheonan 330-714 (Korea, Republic of); Knowles, Jonathan C. [Department of Nanobiomedical Science and WCU Research Center of Nanobiomedical Science, Dankook University, Chungnam 330-714 (Korea, Republic of); Division of Biomaterials and Tissue Engineering, Eastman Dental Institute, University College London, 256 Gray' s Inn Road, London WC1X 8LD (United Kingdom); Wall, Ivan B., E-mail: i.wall@ucl.ac.uk [Department of Nanobiomedical Science and WCU Research Center of Nanobiomedical Science, Dankook University, Chungnam 330-714 (Korea, Republic of); Department of Biochemical Engineering, University College London, Torrington Place, London, WC1E 7JE (United Kingdom)

    2013-05-01

    There is a continuing need to develop scaffold materials that can promote vascularisation throughout the tissue engineered construct. This study investigated the effect of cobalt oxide (CoO) doped into titanium phosphate glasses on material properties, biocompatibility and vascular endothelial growth factor (VEGF) secretion by osteoblastic MG63 cells. Glasses composed of (P{sub 2}O{sub 5}){sub 45}(Na{sub 2}O){sub 20}(TiO{sub 2}){sub 05}(CaO){sub 30−x}(CoO){sub x}(x = 0, 5, 10, and 15 mol%) were fabricated and the effect of Co on physicochemical properties including density, glass transition temperature (T{sub g}), degradation rate, ion release, and pH changes was assessed. The results showed that incorporation of CoO into the glass system produced an increase in density with little change in T{sub g}. It was then confirmed that the pH did not change significantly when CoO was incorporated in the glass, and stayed constant at around 6.5–7.0 throughout the dissolution study period of 336 h. Ion release results followed a specific pattern with increasing amounts of CoO. In general, although incorporation of CoO into a titanium phosphate glass increased its density, other bulk and surface properties of the glass did not show any significant changes. Cell culture studies performed using MG63 cells over a 7-day period indicated that the glasses provide a stable surface for cell attachment and are biocompatible. Furthermore, VEGF secretion was significantly enhanced on all glasses compared with standard tissue culture plastic and Co doping enhanced this effect further. In conclusion, the developed Co-doped glasses are stable and biocompatible and thus offer enhanced potential for engineering vascularized tissue. - Highlights: ► Phosphate-based glasses can be successfully doped with cobalt oxide. ► The resulting glass is highly stable with low degradation rate. ► Co-doped glasses are biocompatible but do not favour cell proliferation. ► Osteoblastic MG63 cells

  10. Zinc and nickel removal in limestone based treatment of acid mine drainage: The relative role of adsorption and co-precipitation

    International Nuclear Information System (INIS)

    Miller, Andrew; Wildeman, Thomas; Figueroa, Linda

    2013-01-01

    Highlights: • Limestone treatment of mining impacted water was simulated in batch reactors. • Zinc and nickel removals were quantified/characterized with a sequential extraction. • Removals were described with a surface complexation and a surface precipitation model. • Extraction/modeling results imply mechanisms beyond adsorption dominate metal removal. - Abstract: Mining influenced water may contain high metal and sulfate loads, and have low pH (acid mine drainage). Removal of these metals prior to environmental discharge is critical to maintain ecosystem vitality. Limestone based passive treatment systems are commonly used for pH neutralization. The same conditions that lead to pH neutralization may also remove a substantial amount of metals from solution, but the connection between treatment conditions and metal removal are not well understood. In this study, zinc and nickel removals are quantified in batch reactor simulated limestone treatment of acid mine drainage. The resulting solid phase is characterized with a sequential extraction procedure, and the removals are interpreted using surface complexation and surface precipitation models. Zinc and nickel removals are closely linked to the initial iron concentration in the mine water, but are also affected by pH, alkalinity, calcium and sulfate concentrations. The surface complexation model was based on literature descriptions of hydrous ferric oxide. In order to obtain a sufficient fit to the data, the surface site density was increased to an unrealistically high value. Uptake data was also fit to an existing surface precipitation model. The values used are similar to those found in previous studies. Both models indicate that adsorption is not the dominant removal process in the treatment system. Using adsorption only models will generally underpredict metal removals within limestone based treatment systems

  11. Influence of core-finishing intervals on tensile strength of cast posts-and-cores luted with zinc phosphate cement

    Directory of Open Access Journals (Sweden)

    Michele Andrea Lopes Iglesias

    2012-08-01

    Full Text Available The core finishing of cast posts-and-cores after luting is routine in dental practice. However, the effects of the vibrations produced by the rotary cutting instruments over the luting cements are not well-documented. This study evaluated the influence of the time intervals that elapsed between the cementation and the core-finishing procedures on the tensile strength of cast posts-and-cores luted with zinc phosphate cement. Forty-eight bovine incisor roots were selected, endodontically treated, and divided into four groups (n = 12: GA, control (without finishing; GB, GC, and GD, subjected to finishing at 20 minutes, 60 minutes, and 24 hours after cementation, respectively. Root canals were molded, and the resin patterns were cast in copper-aluminum alloy. Cast posts-and-cores were luted with zinc phosphate cement, and the core-finishing procedures were applied according to the groups. The tensile tests were performed at a crosshead speed of 0.5 mm/min for all groups, 24 hours after the core-finishing procedures. The data were subjected to one-way analysis of variance (ANOVA and Tukey's test (α = 0.05. No significant differences were observed in the tensile strengths between the control and experimental groups, regardless of the time interval that elapsed between the luting and finishing steps. Within the limitations of the present study, it was demonstrated that the core-finishing procedures and time intervals that elapsed after luting did not appear to affect the retention of cast posts-and-cores when zinc phosphate cement was used.

  12. Microstructural characterization of dental zinc phosphate cements using combined small angle neutron scattering and microfocus X-ray computed tomography

    Czech Academy of Sciences Publication Activity Database

    Viani, Alberto; Sotiriadis, Konstantinos; Kumpová, Ivana; Mancini, L.; Appavou, M.-S.

    2017-01-01

    Roč. 33, č. 4 (2017), s. 402-417 ISSN 0109-5641 R&D Projects: GA MŠk(CZ) LO1219 Keywords : zinc phosphate cements * small angle neutron scattering * X-ray micro-computed tomography * X-ray powder diffraction * zinc oxide * acid-base cements Subject RIV: JJ - Other Materials OBOR OECD: Composites (including laminates, reinforced plastics, cermets, combined natural and synthetic fibre fabrics Impact factor: 4.070, year: 2016 https://www.sciencedirect.com/science/article/pii/S0109564116305127

  13. X-ray absorption spectroscopy on phosphoric-salt pellets. Determination of the geometric and electronic structure of metal-oxide doped sodium-phosphate glasses

    International Nuclear Information System (INIS)

    Brendebach, B.

    2004-02-01

    Sodium metaphosphate glasses doped with transition metal oxides show characteristic colors. X-ray absorption spectroscopy (XAS) investigations provide information whether the coloration stems from different electronic transitions or changes in the geometrical structure of the glasses. Even though the violet color of MnO y -doped glasses is considered as an evidence for Mn 3+ -ions, Mn K-XAS reveals that the majority of the manganese ions are in the oxidation state +II and have a mixed coordination of four and six oxygen atoms, respectively. The oxygen coordination around the nickel ions in NiO-doped glasses with different metall oxide concentrations is always six. The change of color from citreous to auburn with increasing nickel oxide content is attributed to a systematic change in the bonding characteristic from mainly ionic-like to a small but significant contribution of covalent-like bonding. Analysis of higher coordination shells provides no indication of the formation of metal oxide clusters. (orig.)

  14. Effect of AlF3 on the Density and Elastic Properties of Zinc Tellurite Glass Systems

    Science.gov (United States)

    Sidek, Haji Abdul Aziz; Rosmawati, Shaharuddin; Halimah, Mohamed Kamari; Matori, Khamirul Amin; Talib, Zainal Abidin

    2012-01-01

    This paper presents the results of the physical and elastic properties of the ternary zinc oxyfluoro tellurite glass system. Systematic series of glasses (AlF3)x(ZnO)y(TeO2)z with x = 0–19, y = 0–20 and z = 80, 85, 90 mol% were synthesized by the conventional rapid melt quenching technique. The composition dependence of the physical, mainly density and molar volume, and elastic properties is discussed in term of the AlF3 modifiers addition that are expected to produce quite substantial changes in their physical properties. The absence of any crystalline peaks in the X-ray diffraction (XRD) patterns of the present glass samples indicates the amorphous nature. The addition of AlF3 lowered the values of the densities in ternary oxyfluorotellurite glass systems. The longitudinal and transverse ultrasonic waves propagated in each glass sample were measured using a MBS8020 ultrasonic data acquisition system. All the velocity data were taken at 5 MHz frequency and room temperature. The longitudinal modulus (L), shear modulus (G), Young’s modulus (E), bulk modulus (K) and Poisson’s ratio (σ) are obtained from both velocities data and their respective density. Experimental data shows the density and elastic moduli of each AlF3-ZnO-TeO2 series are found strongly depend upon the glass composition. The addition of AlF3 modifiers into the zinc tellurite causes substantial changes in their density, molar volume as well as their elastic properties.

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

    International Nuclear Information System (INIS)

    Yasaka, P.; Pattanaboonmee, N.; Kim, H.J.; Limkitjaroenporn, P.; Kaewkhao, J.

    2014-01-01

    Highlights: • 10ZnO:xBi 2 O 3 :(90−x)B 2 O 3 , (ZBB) glasses were prepared. • Radiation shielding and optical properties were investigated. • Higher 25 mol% of Bi 2 O 3 show better shielding property compared with concretes. • ZBB glasses can develop as a Pb-free radiation shielding material. - Abstract: In this work, the zinc bismuth borate (ZBB) glasses of the composition 10ZnO:xBi 2 O 3 :(90−x)B 2 O 3 (where x = 15, 20, 25 and 30 mol%) were prepared by the melt quenching technique. Their radiation shielding and optical properties were investigated and compared with theoretical calculations. The mass attenuation coefficients of ZBB glasses have been measured at different energies obtained from a Compton scattering technique. The results show a decrease of the mass attenuation coefficient, effective atomic number and effective electron density values with increasing of gamma-ray energies; and good agreements between experimental and theoretical values. The glass samples with Bi 2 O 3 concentrations higher than 25 mol% (25 and 30 mol%) were observed with lower mean free path (MFP) values than all the standard shielding concretes studied. These results are indications that the ZBB glasses in the present study may be developed as a lead-free radiation shielding material in the investigated energy range

  16. A Solid-State NMR Experiment: Analysis of Local Structural Environments in Phosphate Glasses

    Science.gov (United States)

    Anderson, Stanley E.; Saiki, David; Eckert, Hellmut; Meise-Gresch, Karin

    2004-01-01

    An experiment that can be used to directly study the local chemical environments of phosphorus in solid amorphous materials is demonstrated. The experiment aims at familiarizing the students of chemistry with the principles of solid-state NMR, by having them synthesize a simple phosphate glass, and making them observe the (super 31)P NMR spectrum,…

  17. Effect of ZnO on phase emergence, microstructure and surface modifications of calcium phosphosilicate glass/glass-ceramics having iron oxide

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, K.; Dixit, A.; Bhattacharya, S.; Jagannath [Technical Physics and Prototype Engineering Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Deo, M.N. [High Pressure Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Kothiyal, G.P., E-mail: gpkoth@barc.gov.in [Technical Physics and Prototype Engineering Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)

    2010-03-01

    The effect of ZnO on phase emergence and microstructure properties of glass and glass-ceramics with composition 25SiO{sub 2}-50CaO-15P{sub 2}O{sub 5}-(10 - x)Fe{sub 2}O{sub 3}-xZnO (where x = 0, 2, 5, 7 mol%) has been studied. They have been characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). Surface modifications of these glass-ceramics in simulated body fluid have been studied using Fourier transform infrared reflection spectroscopy (FTIR), XPS and SEM. Results have shown a decrease in the fraction of non-bridging oxygen with increase in zinc oxide content. Emergence of crystalline phases in glass-ceramics at different heat treatment temperatures was studied using XRD. When glass is heat treated at 800 deg. C calcium phosphate, hematite and magnetite are developed as major phases in the glass-ceramics samples with ZnO up to 5 mol%. In addition to these, calcium silicate (Ca{sub 3}Si{sub 2}O{sub 7}) phase is also observed when glass is heat treated at 1000 deg. C. The microstructure of the glass-ceramics heat treated at 800 deg. C exhibits the formation of nano-size (40-50 nm) grains. On heat treatment at 1000 deg. C crystallites grow to above 50 nm size and more than one phase are observed in the microstructure. The formation of thin flake-like structure with coarse particles is observed at high zinc oxide concentration (x = 7 mol%). In vitro studies have shown the surface modifications and formation of Ca-P-rich layer on the glass-ceramics when immersed in simulated body fluids (SBF) for different durations. The bioactive response was found to depend on ZnO content.

  18. Effect of ZnO on phase emergence, microstructure and surface modifications of calcium phosphosilicate glass/glass-ceramics having iron oxide

    International Nuclear Information System (INIS)

    Sharma, K.; Dixit, A.; Bhattacharya, S.; Jagannath; Deo, M.N.; Kothiyal, G.P.

    2010-01-01

    The effect of ZnO on phase emergence and microstructure properties of glass and glass-ceramics with composition 25SiO 2 -50CaO-15P 2 O 5 -(10 - x)Fe 2 O 3 -xZnO (where x = 0, 2, 5, 7 mol%) has been studied. They have been characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). Surface modifications of these glass-ceramics in simulated body fluid have been studied using Fourier transform infrared reflection spectroscopy (FTIR), XPS and SEM. Results have shown a decrease in the fraction of non-bridging oxygen with increase in zinc oxide content. Emergence of crystalline phases in glass-ceramics at different heat treatment temperatures was studied using XRD. When glass is heat treated at 800 deg. C calcium phosphate, hematite and magnetite are developed as major phases in the glass-ceramics samples with ZnO up to 5 mol%. In addition to these, calcium silicate (Ca 3 Si 2 O 7 ) phase is also observed when glass is heat treated at 1000 deg. C. The microstructure of the glass-ceramics heat treated at 800 deg. C exhibits the formation of nano-size (40-50 nm) grains. On heat treatment at 1000 deg. C crystallites grow to above 50 nm size and more than one phase are observed in the microstructure. The formation of thin flake-like structure with coarse particles is observed at high zinc oxide concentration (x = 7 mol%). In vitro studies have shown the surface modifications and formation of Ca-P-rich layer on the glass-ceramics when immersed in simulated body fluids (SBF) for different durations. The bioactive response was found to depend on ZnO content.

  19. Removal of Cadmium, Zinc, Lead and Copper by Sorption on Leaching Residue from Nickel Production

    Directory of Open Access Journals (Sweden)

    Miroslava Václavíková

    2006-12-01

    Full Text Available A leaching resudue from the nickel production (LRNi, was used to study the removal of selected bivalent cations (Cd, Pb, Cu and Zn from model aqueous solutions. Batch-type experiments have been performed in solutions with initial concentrations of heavy metals in the range of 20-400 mg.L-1 and the adsorbent dosage 2 g.L-1. All adsorption experiments were carried out at ambient temperature (22+1°C in orbital shaker. The experimental data were modeled with Langmuir and Freundlich isotherms. The relatively high uptake indicated that LRNi can adsorb considerable amounts of cadmium and zinc (maximum uptake capacity for cadmium: 25 mg/g at pH 7.2 and ca. 40 mg/g for zinc at pH 7. A significant uptake was also observed for copper and lead at pH 5.8 and 6 respectively, which was attributed to the precipitation of the respective insoluble hydroxides.

  20. Mg- and/or Sr-doped tricalcium phosphate/bioactive glass composites: Synthesis, microstructure and biological responsiveness

    Energy Technology Data Exchange (ETDEWEB)

    Bellucci, Devis, E-mail: devis.bellucci@unimore.it [Department of Engineering “E. Ferrari”, University of Modena and Reggio Emilia, Via Vignolese 905, 41125 Modena (Italy); Sola, Antonella [Department of Engineering “E. Ferrari”, University of Modena and Reggio Emilia, Via Vignolese 905, 41125 Modena (Italy); Cacciotti, Ilaria [University of Rome " Niccolò Cusano" , UdR INSTM, Via Don Carlo Gnocchi 3, 00166, Rome (Italy); Bartoli, Cristina; Gazzarri, Matteo [Department of Chemistry and Industrial Chemistry, University of Pisa, UdR INSTM — Pisa, Via Risorgimento 35, 56127 Pisa (Italy); Bianco, Alessandra [Department of Enterprise Engineering, INSTM RU “Rome-Tor Vergata”, Via del Politecnico 1, 00133 Roma (Italy); Chiellini, Federica [Department of Chemistry and Industrial Chemistry, University of Pisa, UdR INSTM — Pisa, Via Risorgimento 35, 56127 Pisa (Italy); Cannillo, Valeria [Department of Engineering “E. Ferrari”, University of Modena and Reggio Emilia, Via Vignolese 905, 41125 Modena (Italy)

    2014-09-01

    Presently, there is an increasing interest towards the composites of calcium phosphates, especially β-tricalcium phosphate (TCP), and bioactive glasses. In the present contribution, the recently developed BG{sub C}a/Mix glass has been used because its low tendency to crystallize allows to sinter the composites at relatively low temperature (i.e. 850 °C), thus minimizing the glass devitrification and the interaction with TCP. A further improvement is the introduction of lab-produced TCP powders doped with specific ions instead of non-doped commercial powders, since the biological properties of materials for bone replacement can be modulated by doping them with certain metallic ions, such as Mg and Sr. Therefore, novel binary composites have been produced by sintering the BG{sub C}a/Mix glass with the addition of pure, Mg-substituted, Sr-substituted or Mg/Sr bisubstituted TCP powders. After an accurate characterization of the starting TCP powders and of the obtained samples, the composites have been used as three-dimensional supports for the culture of mouse calvaria-derived pre-osteoblastic cells. The samples supported cell adhesion and proliferation and induced promising mechanisms of differentiation towards an osteoblastic phenotype. In particular, the Mg/Sr bi-doped samples seemed to better promote the differentiation process thus suggesting a combined stimulatory effect of Mg{sup 2+} and Sr{sup 2+} ions.

  1. Mg- and/or Sr-doped tricalcium phosphate/bioactive glass composites: Synthesis, microstructure and biological responsiveness

    International Nuclear Information System (INIS)

    Bellucci, Devis; Sola, Antonella; Niccolò Cusano, UdR INSTM, Via Don Carlo Gnocchi 3, 00166, Rome (Italy))" data-affiliation=" (University of Rome Niccolò Cusano, UdR INSTM, Via Don Carlo Gnocchi 3, 00166, Rome (Italy))" >Cacciotti, Ilaria; Bartoli, Cristina; Gazzarri, Matteo; Bianco, Alessandra; Chiellini, Federica; Cannillo, Valeria

    2014-01-01

    Presently, there is an increasing interest towards the composites of calcium phosphates, especially β-tricalcium phosphate (TCP), and bioactive glasses. In the present contribution, the recently developed BG C a/Mix glass has been used because its low tendency to crystallize allows to sinter the composites at relatively low temperature (i.e. 850 °C), thus minimizing the glass devitrification and the interaction with TCP. A further improvement is the introduction of lab-produced TCP powders doped with specific ions instead of non-doped commercial powders, since the biological properties of materials for bone replacement can be modulated by doping them with certain metallic ions, such as Mg and Sr. Therefore, novel binary composites have been produced by sintering the BG C a/Mix glass with the addition of pure, Mg-substituted, Sr-substituted or Mg/Sr bisubstituted TCP powders. After an accurate characterization of the starting TCP powders and of the obtained samples, the composites have been used as three-dimensional supports for the culture of mouse calvaria-derived pre-osteoblastic cells. The samples supported cell adhesion and proliferation and induced promising mechanisms of differentiation towards an osteoblastic phenotype. In particular, the Mg/Sr bi-doped samples seemed to better promote the differentiation process thus suggesting a combined stimulatory effect of Mg 2+ and Sr 2+ ions

  2. Catalytic CO Oxidation over Au Nanoparticles Loaded Nanoporous Nickel Phosphate Composite

    Directory of Open Access Journals (Sweden)

    Xiaonan Leng

    2015-01-01

    Full Text Available Au/nickel phosphate-5 (Au/VSB-5 composite with the noble metal loading amount of 1.43 wt.% is prepared by using microporous VSB-5 nanocrystals as the support. Carbon monoxide (CO oxidation reaction is carried out over the sample with several catalytic cycles. Complete conversion of CO is achieved at 238°C over the catalyst at the first catalytic cycle. The catalytic activity improved greatly at the second cycle with the complete conversion fulfilled at 198°C and preserved for the other cycles. A series of experiments such as X-ray diffraction (XRD, high resolution transmission electron microscopy (HRTEM, ultraviolet-visible (UV-vis spectroscopy, and X-ray photoelectron spectroscopy (XPS are carried out to characterize the catalysts before and after the reaction to study the factors influencing this promotion at the second cycle.

  3. Glass containing radioactive nuclear waste

    International Nuclear Information System (INIS)

    Boatner, L.A.; Sales, B.C.

    1985-01-01

    Lead-iron phosphate glasses containing a high level of Fe 2 O 3 for use as a storage medium for high-level-radioactive nuclear waste. By combining lead-iron phosphate glass with various types of simulated high-level nuclear waste, a highly corrosion resistant, homogeneous, easily processed glass can be formed. For corroding solutions at 90 C, with solution pH values in the range between 5 and 9, the corrosion rate of the lead-iron phosphate nuclear waste glass is at least 10 2 to 10 3 times lower than the corrosion rate of a comparable borosilicate nuclear waste glass. The presence of Fe 2 O 3 in forming the lead-iron phosphate glass is critical. Lead-iron phosphate nuclear waste glass can be prepared at temperatures as low as 800 C, since they exhibit very low melt viscosities in the 800 to 1050 C temperature range. These waste-loaded glasses do not readily devitrify at temperatures as high as 550 C and are not adversely affected by large doses of gamma radiation in H 2 O at 135 C. The lead-iron phosphate waste glasses can be prepared with minimal modification of the technology developed for processing borosilicate glass nuclear waste forms. (author)

  4. Spectroscopic investigation of zinc tellurite glasses doped with Yb(3+) and Er(3+) ions.

    Science.gov (United States)

    Bilir, Gökhan; Kaya, Ayfer; Cinkaya, Hatun; Eryürek, Gönül

    2016-08-05

    This paper presents a detailed spectroscopic investigation of zinc tellurite glasses with the compositions (0.80-x-y) TeO2+(0.20) ZnO+xEr2O3+yYb2O3 (x=0, y=0; x=0.004, y=0; x=0, y=0.05 and x=0.004, y=0.05 per moles). The samples were synthesized by the conventional melt quenching method. The optical absorption and emission measurements were conducted at room temperature to determine the spectral properties of lanthanides doped zinc tellurite glasses and, to study the energy transfer processes between dopant lanthanide ions. The band gap energies for both direct and indirect possible transitions and the Urbach energies were measured from the absorption spectra. The absorption spectra of the samples were analyzed by using the Judd-Ofelt approach. The effect of the ytterbium ions on the emission properties of erbium ions was investigated and the energy transfer processes between dopant ions were studied by measuring the up-conversion emission properties of the materials. The color quality parameters of obtained visible up-conversion emission were also determined as well as possibility of using the Er(3+) glasses as erbium doped fiber amplifiers at 1.55μm in infrared emission region. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Spectroscopic properties of Ho{sup 3+}-doped K-Sr-Al phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Linganna, K.; Rathaiah, M.; Venkatramu, V. [Yogi Vemana University, Department of Physics, Kadapa (India); Jayasankar, C.K. [Sri Venkateswara University, Department of Physics, Tirupati (India)

    2014-05-15

    Trivalent holmium-doped K-Sr-Al phosphate glasses (P{sub 2}O{sub 5}-K{sub 2}O-SrO-Al{sub 2}O{sub 3}-Ho{sub 2}O{sub 3}) were prepared, and their spectroscopic properties have been evaluated using absorption, emission, and excitation measurements. The Judd-Ofelt theory has been used to derive spectral intensities of various absorption bands from measured absorption spectrum of 1.0 mol% Ho{sub 2}O{sub 3}-doped K-Sr-Al phosphate glass. The Judd-Ofelt intensity parameters (Ω{sub λ}, x 10{sup -20} cm{sup 2}) have been determined of the order of Ω{sub 2} = 11.39, Ω{sub 4} = 3.59, and Ω{sub 6} = 2.92, which in turn used to derive radiative properties such as radiative transition probability, radiative lifetime, branching ratios, etc. for excited states of Ho{sup 3+} ions. The radiative lifetimes for the {sup 5}F{sub 4}, {sup 5}S{sub 2}, and {sup 5}F{sub 5} levels of Ho{sup 3+} ions are found to be 169, 296, and 317 μs, respectively. The stimulated emission cross-section for 2.05-μm emission was calculated by the McCumber theory and found to be 9.3 x 10{sup -21} cm{sup 2}. The wavelength-dependent gain coefficient with population inversion rate has been evaluated. The results obtained in the titled glasses are discussed systematically and compared with other Ho{sup 3+}-doped systems to assess the possibility for visible and infrared device applications. (orig.)

  6. Influence of triethyl phosphate on phosphatase activity in shooting range soil: Isolation of a zinc-resistant bacterium with an acid phosphatase.

    Science.gov (United States)

    Story, Sandra; Brigmon, Robin L

    2017-03-01

    Phosphatase-mediated hydrolysis of organic phosphate may be a viable means of stabilizing heavy metals via precipitation as a metal phosphate in bioremediation applications. We investigated the effect of triethyl phosphate (TEP) on soil microbial-phosphatase activity in a heavy-metal contaminated soil. Gaseous TEP has been used at subsurface sites for bioremediation of organic contaminants but not applied in heavy-metal contaminated areas. Little is known about how TEP affects microbial activity in soils and it is postulated that TEP can serve as a phosphate source in nutrient-poor groundwater and soil/sediments. Over a 3-week period, TEP amendment to microcosms containing heavy-metal contaminated soil resulted in increased activity of soil acid-phosphatase and repression of alkaline phosphatase, indicating a stimulatory effect on the microbial population. A soil-free enrichment of microorganisms adapted to heavy-metal and acidic conditions was derived from the TEP-amended soil microcosms using TEP as the sole phosphate source and the selected microbial consortium maintained a high acid-phosphatase activity with repression of alkaline phosphatase. Addition of 5mM zinc to soil-free microcosms had little effect on acid phosphatase but inhibited alkaline phosphatase. One bacterial member from the consortium, identified as Burkholderia cepacia sp., expressed an acid-phosphatase activity uninhibited by high concentrations of zinc and produced a soluble, indigo pigment under phosphate limitation. The pigment was produced in a phosphate-free medium and was not produced in the presence of TEP or phosphate ion, indicative of purple acid-phosphatase types that are pressed by bioavailable phosphate. These results demonstrate that TEP amendment was bioavailable and increased overall phosphatase activity in both soil and soil-free microcosms supporting the possibility of positive outcomes in bioremediation applications. Copyright © 2016. Published by Elsevier Inc.

  7. Spatially selective Au nanoparticle growth in laser-quality glass controlled by UV-induced phosphate-chain cross-linkage

    International Nuclear Information System (INIS)

    Sigaev, Vladimir N; Savinkov, Vitaly I; Lotarev, Sergey V; Shakhgildyan, Georgiy Yu; Paleari, Alberto; Lorenzi, Roberto

    2013-01-01

    Herein we describe how UV excitation of localized electronic states in phosphate glasses can activate structural rearrangements that influence the kinetics of Au nanoparticle (NP) thermal growth in Au-doped glass. The results suggest a novel strategy to address the problem of controlling nano-assembly processes of metal NP patterns in fully inorganic and chemically stable hard materials, such as laser-quality glasses. We show that the mechanism is promoted by opening and subsequent cross-linkage of phosphate chains under UV excitation of non-bridging groups in the amorphous network of the glass, with a consequent modification of Au diffusion and metal NP growth. Importantly, the micro-Raman mapping of the UV-induced modifications demonstrates that the process is restricted within the beam waist region of the focused UV laser beam. This fact is consistent with the need for more than one excitation event, close in time and in space, in order to promote structural cross-linkage and Au diffusion confinement. The stability of the photo-induced modifications makes it possible to design new metal patterning approaches for the fabrication of three-dimensional metal structures in laser-quality materials for high-power nonlinear applications. (paper)

  8. Spatially selective Au nanoparticle growth in laser-quality glass controlled by UV-induced phosphate-chain cross-linkage.

    Science.gov (United States)

    Sigaev, Vladimir N; Savinkov, Vitaly I; Lotarev, Sergey V; Shakhgildyan, Georgiy Yu; Lorenzi, Roberto; Paleari, Alberto

    2013-06-07

    Herein we describe how UV excitation of localized electronic states in phosphate glasses can activate structural rearrangements that influence the kinetics of Au nanoparticle (NP) thermal growth in Au-doped glass. The results suggest a novel strategy to address the problem of controlling nano-assembly processes of metal NP patterns in fully inorganic and chemically stable hard materials, such as laser-quality glasses. We show that the mechanism is promoted by opening and subsequent cross-linkage of phosphate chains under UV excitation of non-bridging groups in the amorphous network of the glass, with a consequent modification of Au diffusion and metal NP growth. Importantly, the micro-Raman mapping of the UV-induced modifications demonstrates that the process is restricted within the beam waist region of the focused UV laser beam. This fact is consistent with the need for more than one excitation event, close in time and in space, in order to promote structural cross-linkage and Au diffusion confinement. The stability of the photo-induced modifications makes it possible to design new metal patterning approaches for the fabrication of three-dimensional metal structures in laser-quality materials for high-power nonlinear applications.

  9. Zinc electrode shape change II. Process and mechanism

    NARCIS (Netherlands)

    Einerhand, R.E.F.; Visscher, W.; de Goeij, J.J.M.; Barendrecht, E.

    1991-01-01

    The process and mechanism of zinc electrode shape change is investigated with the radiotracer technique. It is shownthat during repeated cycling of the nickel oxide/zinc battery zinc material is transported over the zinc electrode via the battery electrolyte. During charge as well as during

  10. Fluorescence properties of Yb3+-Er3+ co-doped phosphate glasses containing silver nanoparticles

    Science.gov (United States)

    Martínez Gámez, Ma A.; Vallejo H, Miguel A.; Kiryanov, A. V.; Licea-Jiménez, L.; Lucio M, J. L.; Pérez-García, S. A.

    2018-04-01

    Er3+-Yb3+ co-doped phosphate glasses containing silver nitrate (SN), were fabricated. Transmission electron microscopy (TEM) and x-ray photoelectron spectroscopy (XPS) analyses were used to evidence the nucleation and presence of silver nanoparticles (SNP). The basic parameters of the glasses were inspected by means of absorption and fluorescence spectra, and fluorescence lifetimes under excitation at 916 nm (in-band of Yb3+), and at 406 nm (in-band of surface plasmon resonance given by the presence of SNP). The spectra as well as estimates for the basic parameters defining the lasing/amplifying potential of the glasses were studied as a function of SN concentration. The experimental results indicate that by increasing the SN content an enhancement of Er3+/Yb3+ fluorescence takes place.

  11. Kinetics of copper nanoparticle precipitation in phosphate glass: an isothermal plasmonic approach.

    Science.gov (United States)

    Sendova, Mariana; Jiménez, José A; Smith, Robert; Rudawski, Nicholas

    2015-01-14

    The kinetics of copper nanoparticle (NP) precipitation in melt-quenched barium-phosphate glass has been studied by in situ isothermal optical micro-spectroscopy. A spectroscopically based approximation technique is proposed to obtain information about the activation energies of nucleation and growth in a narrow temperature range (530-570 °C). Pre-plasmonic and plasmonic NP precipitation stages are identified separated in time. The process as a whole is discussed employing classical nucleation/growth theory and the Kolmogorov-Johnson-Mehl-Avrami phase change model. Activation energies of 3.9(7) eV and 2.6(5) eV have been estimated for the pre-plasmonic and plasmonic spectroscopically assessed stages, respectively. High resolution transmission electron microscopy, differential scanning calorimetry, and Raman spectroscopy were used as complementary techniques for studying the nanoparticulate phase and glass host structure. An empirical linear dependence of the diffusion activation energy on the glass transition temperature with broad applicability is suggested.

  12. Investigations on optical properties of Sm3+ ion doped boro-phosphate glasses

    Science.gov (United States)

    Vijayakumar, R.; Suthanthirakumar, P.; Karthikeyan, P.; Marimuthu, K.

    2015-06-01

    The Sm3+ doped Boro-phosphate glasses with the chemical composition 60H3BO3+20Li2CO3+10ZnO+(10-x) H6NO4P+xSm2O3 (where x= 0.1, 0.5, 1 and 2 in wt%) have been prepared by melt quenching technique. The prepared glasses were characterized through optical absorption and luminescence spectral measurements. The band gap energies corresponding to the direct and indirect allowed transitions and the Urbach's energy values were estimated from the absorption spectra. Judd-Ofelt intensity parameters have been derived to predict the radiative properties of the various emission transitions. In order to identify the emission color of the prepared glasses, the emission intensities were analyzed using CIE 1931 color chromaticity diagram. The energy transfer process takes place between Sm3+-Sm3+ ions through cross-relaxation mechanism have also been investigated and the results were discussed and reported.

  13. Role of lithium ions on the physical, structural and optical properties of zinc boro tellurite glasses

    Science.gov (United States)

    Rani, S.; Ahlawat, N.; Parmar, R.; Dhankhar, S.; Kundu, R. S.

    2018-01-01

    Lithium zinc boro tellurite glasses with compositions xLi2O-(100-x) [0.25ZnO-0.15B2O3-0.60TeO2] [where x = 0, 5, 10, 15 and 20 mol%] have been prepared by melt-quench technique. The amorphous nature of the prepared system is ascertained by X-ray diffraction. The density and molar volume are found to decrease with the increase in concentration of Li2O. The differential scanning calorimetry is used to calculate the glass transition temperature (Tg) and the observed values are found to be decreased. The IR and Raman spectra indicate that Li2O acts as a network modifier in the glass matrix. In the present system, tellurium exists as TeO4 and TeO3, B2O3 in the form of BO4 and BO3 and zinc oxide exists as ZnO4 structural units. The values of the optical band gap are estimated from the fitting of Mott and Davis's and model. A better convergence is achieved between experimental observed spectra of absorption coefficient and hydrogenic excitonic model. The optical band gap energy increases, whereas refractive index and molar refractivity follow the reverse trend with Li2O. The range of metallization criterion suggests that these glasses may be a potential candidate for nonlinear optical materials.

  14. Effects of CuO co-doping on γ-ray irradiation resistance of active ions doped phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zhihuan [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); ENEA-UTTMAT, Via Anguillarese 301, 00123 Rome (Italy); Baccaro, Stefania; Cemmi, Alessia [ENEA-UTTMAT, Via Anguillarese 301, 00123 Rome (Italy); Shen, Wei [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Chen, Guorong, E-mail: grchen@ecust.edu.cn [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China)

    2013-09-15

    The effect of copper ion doping on the γ-ray irradiation resistance of Mn{sup 2+} and Pr{sup 3+} doped phosphate glasses has been studied. UV–visible transmission spectra and photoluminescence spectra have been measured before and after γ-irradiation to characterize the radiation-induced defects. The electron paramagnetic resonance spectra of the irradiated samples with, and without Cu ions have been compared to show the ability of Cu ions to suppress the generation of radiation-induced color centers. The differential transmission spectra and the radiation-induced absorption coefficients have also been calculated for discussion of the observed phenomena. The much improved γ-irradiation resistance of Mn{sup 2+} and Pr{sup 3+} doped phosphate glasses has been demonstrated through CuO co-doping.

  15. Hydrothermal synthesis and characterization of a two-dimensional piperazinium cobalt–zinc phosphate via a metastable one-dimensional phase

    International Nuclear Information System (INIS)

    Torre-Fernández, Laura; Khainakova, Olena A.; Espina, Aránzazu; Amghouz, Zakariae; Khainakov, Sergei A.; Alfonso, Belén F.; Blanco, Jesús A.; García, José R.; García-Granda, Santiago

    2015-01-01

    A two-dimensional piperazinium cobalt–zinc phosphate, formulated as (C 4 N 2 H 12 ) 1.5 (Co 0.6 Zn 0.4 ) 2 (HPO 4 ) 2 (PO 4 )·H 2 O (2D), was synthesized under hydrothermal conditions. The crystal structure was determined using single-crystal X-ray diffraction data (monoclinic P2 1 /c, a=8.1165(3) Å, b=26.2301(10) Å, c=8.3595(4) Å, and β=110.930(5)°) and the hydrogen atom positions were optimized by DFT calculations. A single-crystal corresponding to one-dimensional metastable phase, (C 4 N 2 H 12 )Co 0.3 Zn 0.7 (HPO 4 ) 2 ·H 2 O (1D), was also isolated and the crystal structure was determined (monoclinic P2 1 /c, a=8.9120(6) Å, b=14.0290(1) Å, c=12.2494(5) Å, and β=130.884(6)°). The bulk was characterized by chemical (C–H–N) analysis, powder X-ray diffraction (PXRD), powder X-ray thermodiffractometry (HT-XRD), transmission electron microscopy (STEM(DF)-EDX and EFTEM), and thermal analysis (TG/SDTA-MS), including activation energy data of its thermal decomposition. The magnetic susceptibility and magnetization measurements show no magnetic ordering down to 4 K. - Graphical abstract: Hydrothermal synthesis and structural characterization of a two-dimensional piperazinium cobalt–zinc phosphate, (C 4 N 2 H 12 ) 1.5 (Co 0.6 Zn 0.4 ) 2 (HPO 4 ) 2 (PO 4 )·H 2 O (2D), have been reported. The crystal structure of a one-dimensional piperazinium cobalt–zinc phosphate, (C 4 N 2 H 12 )Co 0.3 Zn 0.7 (HPO 4 ) 2 ·H 2 O (1D) a metastable phase during the hydrothermal synthesis, was also determined. The thermal behavior of 2D compound is strongly dependent on the selected heating rate and the magnetic susceptibility and magnetization measurements show no magnetic ordering down to 4 K. - Highlights: • A 2D piperazinium cobalt–zinc phosphate has been synthesized and characterized. • Crystal structure of 1D metastable phase was also determined. • Thermal behavior of 2D compound is strongly dependent on the selected heating rate. • Magnetic

  16. The influence of green microstructure and sintering parameters on precipitation process during copper-nickel-zinc ferrites sintering

    International Nuclear Information System (INIS)

    Barba, A.; Clausell, C.; Jarque, J. C.; Monzo, M.

    2014-01-01

    Microstructural changes that occur during heat treatment of copper-nickel-zinc ferrites have been studied. The process of precipitation of the two types of crystals that occur during the sintering process has been analyzed. It is found that this process depends on dry relative density of the press specimens and on the following sintering parameters: sintering temperature, sintering time and cooling rate of the thermal cycle. Crystal precipitates characterization have been done by scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) analysis, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). These techniques have allowed to determine the nature of these crystals, which in this case correspond to zinc and copper oxides. It has been used two chemical reactions to explain the bulk precipitation and subsequent re-dissolution of these crystal precipitates during sintering. (Author)

  17. High emittance black nickel coating on copper substrate for space applications

    Energy Technology Data Exchange (ETDEWEB)

    Somasundaram, Soniya, E-mail: jrf0013@isac.gov.in; Pillai, Anju M., E-mail: anjum@isac.gov.in; Rajendra, A., E-mail: rajendra@isac.gov.in; Sharma, A.K., E-mail: aks@isac.gov.in

    2015-09-15

    Highlights: • High emittance black nickel coating is obtained on copper substrate. • The effect of various process parameters on IR emittance is studied systematically. • Process parameters are optimized to develop a high emittance black nickel coating. • Coating obtained using the finalized parameters exhibited an emittance of 0.83. • SEM and EDAX are used for coating characterization. - Abstract: Black nickel, an alloy coating of zinc and nickel, is obtained on copper substrate by pulse electrodeposition from a modified Fishlock bath containing nickel sulphate, nickel ammonium sulphate, zinc sulphate and ammonium thiocyanate. A nickel undercoat of 4–5 μm thickness is obtained using Watts bath to increase the corrosion resistance and adhesion of the black nickel coating. The effect of bath composition, temperature, solution pH, current density and plating time on the coating appearance and corresponding infra-red emittance of the coating is investigated systematically. Process parameters are optimized to develop a high emittance space worthy black nickel coating to improve the heat radiation characteristics. The effect of the chemistry of the plating bath on the coating composition was studied using energy dispersive X-ray analysis (EDAX) of the coatings. The 5–6 μm thick uniform jet black zinc–nickel alloy coating obtained with optimized process exhibited an emittance of 0.83 and an absorbance of 0.92. The zinc to nickel ratio of black nickel coatings showing high emittance and appealing appearance was found to be in the range 2.3–2.4.

  18. Incorporation of casein phosphopeptide-amorphous calcium phosphate into a glass-ionomer cement.

    Science.gov (United States)

    Mazzaoui, S A; Burrow, M F; Tyas, M J; Dashper, S G; Eakins, D; Reynolds, E C

    2003-11-01

    Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) nanocomplexes have been shown to prevent demineralization and promote remineralization of enamel subsurface lesions in animal and in situ caries models. The aim of this study was to determine the effect of incorporating CPP-ACP into a self-cured glass-ionomer cement (GIC). Incorporation of 1.56% w/w CPP-ACP into the GIC significantly increased microtensile bond strength (33%) and compressive strength (23%) and significantly enhanced the release of calcium, phosphate, and fluoride ions at neutral and acidic pH. MALDI mass spectrometry also showed casein phosphopeptides from the CPP-ACP nanocomplexes to be released. The release of CPP-ACP and fluoride from the CPP-ACP-containing GIC was associated with enhanced protection of the adjacent dentin during acid challenge in vitro.

  19. Optical properties of highly Er{sup 3+}-doped sodium-aluminium-phosphate glasses for broadband 1.5 {mu}m emission

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, A. Amarnath [Nanophotonics Laboratory, Department of Physics, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016 (India); Babu, S. Surendra [Laser Instrumentation Design Centre, Instrument Research and Development Establishment, Dehradun 248008 (India); Pradeesh, K. [Nanophotonics Laboratory, Department of Physics, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016 (India); Otton, C.J. [Valencia Nanophotonics Technology Center, Universidad Politecnica de Valencia, 46022 Valencia (Spain); Vijaya Prakash, G., E-mail: prakash@physics.iitd.ac.in [Nanophotonics Laboratory, Department of Physics, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016 (India)

    2011-03-03

    Research highlights: > Highly Er{sup 3+} doped phosphate glasses for the 1.54 {mu}m laser emission were explored. > Emission from these doped glasses shows larger lifetimes and quantum efficiencies. > Optical amplifier parameters are greater than other reported phosphate glasses. > The durability and obtained results are most favourable for short-length amplifiers. - Abstract: Erbium-doped Na{sub 3}Al{sub 2}P{sub 3}O{sub 12} (NAP) glasses with compositions 92NAP-(8-x)Al{sub 2}O{sub 3}-(x)Er{sub 2}O{sub 3} (where x = 2-8) were prepared and characterized for absorption, visible and NIR emission and decay time properties. Judd-Ofelt analysis has been carried out to predict radiative properties of luminescent levels of Er{sup 3+} ions. Comparatively larger photoluminescence lifetimes (7.86 ms) and larger quantum efficiencies (74%) for the laser transition, {sup 4}I{sub 13/2} {yields} {sup 4}I{sub 15/2} (at 1.54 {mu}m) are observed. The moisture insensitivity, large Er{sup 3+} ion doping capability and relatively high-gain and broad emission at 1.5 {mu}m are the most notable features of these glasses to realize efficient short-length optical amplifiers.

  20. Role of SrO on the bioactivity behavior of some ternary borate glasses and their glass ceramic derivatives

    Science.gov (United States)

    Abdelghany, A. M.; Ouis, M. A.; Azooz, M. A.; ElBatal, H. A.; El-Bassyouni, G. T.

    2016-01-01

    Borate glasses containing SrO substituting both CaO and NaO were prepared and characterized for their bioactivity or bone bonding ability. Glass ceramic derivatives were prepared by thermal heat treatment process. FTIR, XRD and SEM measurements for the prepared glass and glass-ceramics before and after immersion in sodium phosphate solution for one and two weeks were carried out. The appearance of two IR peaks within the range 550-680 cm-1 after immersion in phosphate solution indicates the formation of hydroxyapatite or equivalent Sr phosphate layer. X-ray diffraction data agree with the FTIR spectral analysis. The solubility test was carried out for both glasses and glass ceramics derivatives in the same phosphate solution. The introduction of SrO increases the solubility for both glasses and glass ceramics and this is assumed to be due to the formation of Sr phosphate which is more soluble than calcium phosphate (hydroxyapatite). SEM images reveal varying changes in the surfaces of glass ceramics after immersion according to the SrO content.

  1. 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.

  2. Production of zinc pellets

    Science.gov (United States)

    Cooper, J.F.

    1996-11-26

    Uniform zinc pellets are formed for use in batteries having a stationary or moving slurry zinc particle electrode. The process involves the cathodic deposition of zinc in a finely divided morphology from battery reaction product onto a non-adhering electrode substrate. The mossy zinc is removed from the electrode substrate by the action of gravity, entrainment in a flowing electrolyte, or by mechanical action. The finely divided zinc particles are collected and pressed into pellets by a mechanical device such as an extruder, a roller and chopper, or a punch and die. The pure zinc pellets are returned to the zinc battery in a pumped slurry and have uniform size, density and reactivity. Applications include zinc-air fuel batteries, zinc-ferricyanide storage batteries, and zinc-nickel-oxide secondary batteries. 6 figs.

  3. Effect of MnO2 doped on physical, structure and optical properties of zinc silicate glasses from waste rice husk ash

    Science.gov (United States)

    Al-Nidawi, Ali Jabbar Abed; Matori, Khamirul Amin; Zakaria, Azmi; Mohd Zaid, Mohd Hafiz

    In this study, an investigation was conducted to explore and synthesize silicate (SiO2) glass from waste rice husk ash (RHA). MnO2 doped zinc silicate glasses with chemical formula [(ZnO)55 + (WRHA)45]100-X[MnO2]X, (where X = 0, 1, 3 and 5 wt%) was prepared by conventional melt quenching technique. The glass samples were characterized using energy dispersive X-ray fluorescence (EDXRF), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Fourier transform infrared (FTIR) spectroscopy, and ultraviolet-visible (UV-Vis) spectroscopy. The results revealed that by increasing the concentration of MnO2, the color of glass samples changed from colorless to brown and the density of glass increased. XRD results showed that a broad halo peak which centered on the low angle (2θ = 30°) indicated the amorphous nature of the glass. FTIR results showed basic structural units of Si-O-Si in non-bridging oxygen, Si-O and Mn-O in the glass network. FESEM result showed a decreasing porosity with an increasing MnO2 content, which was attributed to the Mn ions resort to occupy interstitial sites inside the pores of glass. Besides, the absorption intensity of glass increased and the band gap value decreased with increasing the MnO2 percentage. In this synthesized glass system of MnO2 doped zinc silicate glasses using RHA as a source of silica, the MnO2 affect most of the properties of the glass system under investigation.

  4. Multi-layer porous fiber-reinforced composites for implants: in vitro calcium phosphate formation in the presence of bioactive glass.

    Science.gov (United States)

    Nganga, Sara; Zhang, Di; Moritz, Niko; Vallittu, Pekka K; Hupa, Leena

    2012-11-01

    Glass-fiber-reinforced composites (FRCs), based on bifunctional methacrylate resin, have recently shown their potential for use as durable cranioplasty, orthopedic and oral implants. In this study we suggest a multi-component sandwich implant structure with (i) outer layers out of porous FRC, which interface the cortical bone, and (ii) inner layers encompassing bioactive glass granules, which interface with the cancellous bone. The capability of Bioglass(®) 45S5 granules (100-250μm) to induce calcium phosphate formation on the surface of the FRC was explored by immersing the porous FRC-Bioglass laminates in simulated body fluid (SBF) for up to 28d. In both static (agitated) and dynamic conditions, bioactive glass granules induced precipitation of calcium phosphate at the laminate surfaces as confirmed by scanning electron microscopy. The proposed dynamic flow system is useful for the in vitro simulation of bone-like apatite formation on various new porous implant designs containing bioactive glass and implant material degradation. Copyright © 2012 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  5. Structural study and DC conductivity of vanadyl doped zinc lithium borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Seema [Physics Department, Deenbandhu Chhotu Ram University of Science & Technology, Murthal-131039 (India); Physics Department, Baba Mast Nath University, Asthal Bohr, Rohtak-124001 (India); Khasa, S., E-mail: skhasa@rediff.com; Dahiya, M. S.; Yadav, Arti [Physics Department, Deenbandhu Chhotu Ram University of Science & Technology, Murthal-131039 (India); Agarwal, A. [Applied Physics Department, Guru Jambheshwar University of Science & Technology, Hisar-125001 (India); Dahiya, S. [Physics Department, Baba Mast Nath University, Asthal Bohr, Rohtak-124001 (India)

    2015-06-24

    Glasses with composition xZnO⋅(30 − x)⋅Li{sub 2}O⋅70B{sub 2}O{sub 3} containing 2 mol% of V{sub 2}O{sub 5} (x = 0, 2, 5, 7 and 10) were prepared by standard melt-quench technique. The amorphous nature of the glass samples was confirmed by using x-ray diffraction. The structural changes in these glasses have been investigated by employing IR spectroscopy in the mid-IR range. The infrared spectroscopic analysis confirms the presence of both triangular and tetraheldral coordinated boron units and absence of boroxol ring. It also shows that metal-oxide vibrations are present which are due to the bonding of lithium and zinc ions with oxygen. The dc conductivity was measured in the temperature range 353-523 K. The dc conductivity results show that conductivity decreases and activation energy increases when Li{sub 2}O is replaced by ZnO, keeping the concentration of B{sub 2}O{sub 3} constant. Decrease in conductivity and increase in activation energy shows that addition of ZnO to the glass matrix shows a “blocking effect” on the overall mobility of alkali ions, but at higher concentration the hopping effect was also observed.

  6. Doping of low-T{sub g} phosphate glass with Al{sub 2}O{sub 3}, B{sub 2}O{sub 3} and SiO{sub 2}: Part I- effect on glass property and stability

    Energy Technology Data Exchange (ETDEWEB)

    Rajbhandari, P., E-mail: p.rajbhandari@sheffield.ac.uk [UCCS UMR-CNRS 8181, Universite de Lille1, Villeneuve d' Ascq (France); Montagne, L. [UCCS UMR-CNRS 8181, Universite de Lille1, Villeneuve d' Ascq (France); Tricot, G. [UCCS UMR-CNRS 8181, Universite de Lille1, Villeneuve d' Ascq (France); LASIR UMR-CNRS 8516, Universite de Lille1, Villeneuve d' Ascq (France)

    2016-11-01

    A zinc alkali pyrophosphate system 46.6ZnO-20Na{sub 2}O-33.5P{sub 2}O{sub 5} presenting low-T{sub g} (339 °C) and good thermal stability has been doped with (1–4) mol% of Al{sub 2}O{sub 3}, B{sub 2}O{sub 3} and SiO{sub 2} to improve the stability of the glass with a minimal increase in glass transition temperature (T{sub g}). XRD and 1D {sup 31}P solid state NMR were used to monitor the isothermal crystallization process occurring at 130 °C above T{sub g}. If the Al{sub 2}O{sub 3} and B{sub 2}O{sub 3} doping significantly improved thermal stability, this property was marginally affected by SiO{sub 2} doping. Viscosity measurements were performed to observe the crystallization effects induced by the doping. It is noteworthy that the T{sub g} values of all the doped compositions with improved stability presented in this work are below 400 °C. Raman spectroscopy, 1D {sup 31}P, {sup 27}Al, {sup 11}B and {sup 29}Si solid state NMR were carried out to determine the structural modifications and coordination states of the doping elements all along the composition line. - Highlights: • Low-Tg phosphate glasses doped with Al{sub 2}O{sub 3}, B{sub 2}O{sub 3} and SiO{sub 2} have been formulated. • Thermal stability of the glass has been improved significantly. • The structural modification induced by doping elements has been studied by employing solid state NMR technique.

  7. Silicate glasses

    International Nuclear Information System (INIS)

    Lutze, W.

    1988-01-01

    Vitrification of liquid high-level radioactive wastes has received the greatest attention, world-wide, compared to any other HLW solidification process. The waste form is a borosilicate-based glass. The production of phosphate-based glass has been abandoned in the western world. Only in the Soviet Union are phosphate-based glasses still being developed. Vitrification techniques, equipment and processes and their remote operation have been developed and studied for almost thirty years and have reached a high degree of technical maturity. Industrial demonstration of the vitrification process has been in progress since 1978. This chapter is a survey of world-wide research and development efforts in nuclear waste glasses and its production technology. The principal glasses considered are silicate glasses which contain boron, i.e., borosilicate glasses

  8. ACUTE TOXICITY OF METALS: NICKEL AND ZINC TO PARAMECIUM BURSARIA AND ITS ENDOSYMBIONTS

    Directory of Open Access Journals (Sweden)

    Patrycja Zagata

    2015-02-01

    Full Text Available Paramecium bursaria is an unicellular organism, widely distributed in the freshwater environment, where heavy metals are common contaminants. The ciliates, also including Paramecium bursaria, are a very abundant group in aquatic ecosystems, what makes them effective biological indicators of water pollutants. Paramecium bursaria is the only Paramecium which has evolved a mutualistic relationship with algae and it harbors these endosymbionts in its own cytoplasm. The algae are also very effective bioindicators of some pollutants because of their ability to biosorption and bioaccumulation of heavy metals. The aim of this study was to determine the acute toxicity of two metals’ compounds: nickel chloride (NiCl2 and zinc chloride (ZnCl2 to Paramecium bursaria and its endosymbionts. The ciliates were incubated in solutions with 5x10-8 to 5x10-2g/dm3 of NiCl2 and with 5x10-8 to 5x10-2g/dm3 of ZnCl2, at the temperature of 180C, in the light/dark conditions (12L/12D. Microscopic observations of cell divisions rate, cell shape changes as well as the swimming behavior, were conducted after 24, 48, 72 and 120 hours of incubation in the tested solutions and were compared to the control sample. Microscopic observations revealed the lethal doses for both compounds, for nickel chloride 5x10-5g/dm3 and for zinc chloride 5x10-3. These observations also revealed that in lesser concentrations than the lethal one, the slowdown and characteristic movements occur after metal addition. The PEA measurements of Fv/Fm parameter were carried out within 4 days, the first one after 24 hours of incubations. The results of this investigation has given us a view of a fluorescence efficiency by revealing that both compounds solutions can have the stimulating effect on Photosystem II, because the lowest fluorescence efficiency was measured in control samples.

  9. Structural and physico-chemical analysis of calcium/strontium substituted, near-invert phosphate based glasses for biomedical applications.

    Science.gov (United States)

    Patel, U; Moss, R M; Hossain, K M Z; Kennedy, A R; Barney, E R; Ahmed, I; Hannon, A C

    2017-09-15

    Neutron diffraction, 23 Na and 31 P NMR, and FTIR spectroscopy have been used to investigate the structural effects of substituting CaO with SrO in a 40P 2 O 5 ·(16-x)CaO·20Na 2 O·24MgO·xSrO glass, where x is 0, 4, 8, 12 and 16mol%. The 31 P solid-state NMR results showed similar amounts of Q 1 and Q 2 units for all of the multicomponent glasses investigated, showing that the substitution of Sr for Ca has no effect on the phosphate network. The M-O coordinations (M=Mg, Ca, Sr, Na) were determined for binary alkali and alkaline earth metaphosphates using neutron diffraction and broad asymmetric distributions of bond length were observed, with coordination numbers that were smaller and bond lengths that were shorter than in corresponding crystals. The Mg-O coordination number was determined most reliably as 5.0(2). The neutron diffraction results for the multicomponent glasses are consistent with a structural model in which the coordination of Ca, Sr and Na is the same as in the binary metaphosphate glass, whereas there is a definite shift of Mg-O bonds to longer distance. There is also a small but consistent increase in the Mg-O coordination number and the width of the distribution of Mg-O bond lengths, as Sr substitutes for Ca. Functional properties, including glass transition temperatures, thermal processing windows, dissolution rates and ion release profiles were also investigated. Dissolution studies showed a decrease in dissolution rate with initial addition of 4mol% SrO, but further addition of SrO showed little change. The ion release profiles followed a similar trend to the observed dissolution rates. The limited changes in structure and dissolution rates observed for substitution of Ca with Sr in these fixed 40mol% P 2 O 5 glasses were attributed to their similarities in terms of ionic size and charge. Phosphate based glasses are extremely well suited for the delivery of therapeutic ions in biomedical applications, and in particular strontium plays an

  10. Effect of nanosecond UV laser irradiation on luminescence and absorption in silver- and copper-containing phosphate glasses

    Science.gov (United States)

    Murashov, A. A.; Sidorov, A. I.; Stoliarchuk, M. V.

    2018-03-01

    Experimental evidence is presented that nanosecond UV laser irradiation of silver- and copper-containing barium phosphate glasses leads to luminescence quenching in the visible range. Subsequent heat treatment induces an absorption in the range 350–500 nm. These effects are due to the ionisation and fragmentation of subnanometre molecular clusters by laser radiation and subsequent (heat treatment-induced) formation of nanoparticles possessing plasmon resonance. Our numerical modelling results demonstrate the feasibility of producing stable AgnCum hybrid molecular clusters in glass. Local modification of the optical properties of glass by laser light can be used for optical information recording.

  11. Characterization and spectroscopic studies of multi-component calcium zinc bismuth phosphate glass ceramics doped with iron ions

    Science.gov (United States)

    Kumar, A. Suneel; Narendrudu, T.; Suresh, S.; Ram, G. Chinna; Rao, M. V. Sambasiva; Tirupataiah, Ch.; Rao, D. Krishna

    2018-04-01

    Glass ceramics with the composition 10CaF2-20ZnO-(15-x)Bi2O3-55P2O5:x Fe2O3(0≤x≤2.5) were synthesized by melt-quenching technique and heat treatment. These glass ceramics were characterized by XRD and SEM. Spectroscopic studies such as optical absorption, EPR were also carried out on these glass ceramics. From the absorption spectra the observed bands around 438 and 660nm are the octahedral transitions of Fe3+ (d5) ions and another band at about 536 nm is the tetrahedral transition of Fe3+ (d5) ions. The absorption spectrum also consist of a band around 991 nm and is attributed to the octahedral transition of Fe2+ ions. The EPR spectra of the prepared glass ceramics have exhibited two resonance signals one at g1=4.32 and another signal at g2=2.008. The observed decrease in band gap energy up to 2 mol% Fe2O3 doped glass ceramics is an evidence for the change of environment around iron ions and ligands from more covalent to less covalent (ionic) and induces higher concentration of NBOs which causes the depolymerization of the glass ceramic network.

  12. Crystallization characteristics of iron-rich glass ceramics prepared from nickel slag and blast furnace slag

    Science.gov (United States)

    Wang, Zhong-Jie; Ni, Wen; Li, Ke-Qing; Huang, Xiao-Yan; Zhu, Li-Ping

    2011-08-01

    The crystallization process of iron-rich glass-ceramics prepared from the mixture of nickel slag (NS) and blast furnace slag (BFS) with a small amount of quartz sand was investigated. A modified melting method which was more energy-saving than the traditional methods was used to control the crystallization process. The results show that the iron-rich system has much lower melting temperature, glass transition temperature ( T g), and glass crystallization temperature ( T c), which can result in a further energy-saving process. The results also show that the system has a quick but controllable crystallization process with its peak crystallization temperature at 918°C. The crystallization of augite crystals begins from the edge of the sample and invades into the whole sample. The crystallization process can be completed in a few minutes. A distinct boundary between the crystallized part and the non-crystallized part exists during the process. In the non-crystallized part showing a black colour, some sphere-shaped augite crystals already exist in the glass matrix before samples are heated to T c. In the crystallized part showing a khaki colour, a compact structure is formed by augite crystals.

  13. Characterization of zinc–nickel alloy electrodeposits obtained from ...

    Indian Academy of Sciences (India)

    Zinc alloy offers superior sacrificial protection to steel as the alloy dissolves more slowly than pure zinc. The degree of protection and the rate of dissolution depend on the alloying metal and its composition. Zinc-nickel alloy may also serve as at less toxic substitute for cadmium. In this paper the physico-chemical ...

  14. High temperature oxidation and crystallization behavior of phosphate glass compositions

    International Nuclear Information System (INIS)

    Russo, Diego; Rodriguez, Diego; Grumbaum, N.; Gonzalez Oliver, Carlos

    2003-01-01

    We analyzed the thermal transformation of three iron phosphate glasses having the following nominal compositions: M4 [70% P 2 O 5 , 30% Fe 2 O 3 ], M5 [85% M4, 15% UO 2 ] y M7 [69.7% P 2 O 5 , 28.6% Fe 2 O 3 , 1,7% Al 2 O 3 ]. Thermogravimetric analysis, DTA (differential thermal analysis) and SAXS (Small Angle X-ray Scattering) were performed.It was observed that it is easily possible to produce glasses in these systems having very low crystallinity.We could determine the final stable crystalline phases [Fe 4 (P 2 O 7 ) 3 , Fe(PO 3 ) 3 and Fe 3 (P 2 O 7 ) 2 ].The presence of uranium ions affects not only the redox effects but also the crystallization of the system.SAXS data obtained during the heating in vacuum up to ∼600degC, gave some variation of scattering intensities vs. scattering vector suggesting the development of an extra phase or some kind inhomogeneities that seems to disappear on heating

  15. Quantum efficiency and excited-state relaxation dynamics in neodymium-doped phosphate laser glasses

    International Nuclear Information System (INIS)

    Caird, J.A.; Ramponi, A.J.; Staver, P.R.

    1991-01-01

    Radiometrically calibrated spectroscopic techniques employing an integrating-sphere detection system have been used to determine the fluorescence quantum efficiencies for two commercially available Nd 3+ -doped phosphate laser glasses, LG-750 and LG-760. Quantum efficiencies and fluorescence lifetimes were measured for samples with various neodymium concentrations. It is shown that the effects of concentration quenching are accurately described when both resonant nonradiative excitation hopping (the Burshtein model) and annihilation by cross relaxation are accounted for by Foerster--Dexter dipole--dipole energy-transfer theory. The Foerster--Dexter critical range for nonradiative excitation hopping was found to be R DD =11 A, while the critical range for cross relaxation was close to R DA =4 A in these glasses. The quantum efficiency at low Nd 3+ concentrations was (92±5)%, implying a nonradiative relaxation rate of 210±150 s -1 for isolated ions. Improved values for the radiative lifetimes and the stimulated emission cross sections for these glasses were also deduced from the measurements

  16. Structural and electrical properties of iron molybdenum phosphate glasses

    International Nuclear Information System (INIS)

    De Oliveira, R.S.; Quixada-Ceara, Univ. Estadual do Ceara; De Paiva, J.A.C.; De Araujo, M.A.B.; Sombra, A. S.B.

    1998-01-01

    iron molybdenum phosphate glasses (xMoO 3 ·(0.6 - x)P 2 O 5 ·0.4Li 2 O) : yFe 2 O 2 with 0≤x≤ 0.6 and y = 0.03 (mol%) prepared in ambient atmosphere using the melt quenching technique were studied by using DC electrical conductivity, 57 Fe Moessbauer and infrared spectroscopies. The Dc conductivity depends on the MoO 3 concentration x. It was observed that, with increasing x, the ratio Fe 2+ /(Fe 3+ + Fe 2+ ) and the Dc conductivity increase. Infrared spectroscopy and X-ray powder diffraction indicate that a Li 2 MoO 4 crystalline phase is present for high MoO 3 content samples (x = 0.5, 0.6)

  17. Hydrothermal synthesis and characterization of a two-dimensional piperazinium cobalt–zinc phosphate via a metastable one-dimensional phase

    Energy Technology Data Exchange (ETDEWEB)

    Torre-Fernández, Laura; Khainakova, Olena A. [Departamentos de Química Física y Analítica y Química Orgánica e Inorgánica, Universidad de Oviedo-CINN, 33006 Oviedo (Spain); Espina, Aránzazu [Servicios Científico Técnicos, Universidad de Oviedo, 33006 Oviedo (Spain); Amghouz, Zakariae, E-mail: amghouz.uo@uniovi.es [Servicios Científico Técnicos, Universidad de Oviedo, 33006 Oviedo (Spain); Khainakov, Sergei A. [Servicios Científico Técnicos, Universidad de Oviedo, 33006 Oviedo (Spain); Alfonso, Belén F.; Blanco, Jesús A. [Departamento de Física, Universidad de Oviedo, 33007 Oviedo (Spain); García, José R.; García-Granda, Santiago [Departamentos de Química Física y Analítica y Química Orgánica e Inorgánica, Universidad de Oviedo-CINN, 33006 Oviedo (Spain)

    2015-05-15

    A two-dimensional piperazinium cobalt–zinc phosphate, formulated as (C{sub 4}N{sub 2}H{sub 12}){sub 1.5}(Co{sub 0.6}Zn{sub 0.4}){sub 2}(HPO{sub 4}){sub 2}(PO{sub 4})·H{sub 2}O (2D), was synthesized under hydrothermal conditions. The crystal structure was determined using single-crystal X-ray diffraction data (monoclinic P2{sub 1}/c, a=8.1165(3) Å, b=26.2301(10) Å, c=8.3595(4) Å, and β=110.930(5)°) and the hydrogen atom positions were optimized by DFT calculations. A single-crystal corresponding to one-dimensional metastable phase, (C{sub 4}N{sub 2}H{sub 12})Co{sub 0.3}Zn{sub 0.7}(HPO{sub 4}){sub 2}·H{sub 2}O (1D), was also isolated and the crystal structure was determined (monoclinic P2{sub 1}/c, a=8.9120(6) Å, b=14.0290(1) Å, c=12.2494(5) Å, and β=130.884(6)°). The bulk was characterized by chemical (C–H–N) analysis, powder X-ray diffraction (PXRD), powder X-ray thermodiffractometry (HT-XRD), transmission electron microscopy (STEM(DF)-EDX and EFTEM), and thermal analysis (TG/SDTA-MS), including activation energy data of its thermal decomposition. The magnetic susceptibility and magnetization measurements show no magnetic ordering down to 4 K. - Graphical abstract: Hydrothermal synthesis and structural characterization of a two-dimensional piperazinium cobalt–zinc phosphate, (C{sub 4}N{sub 2}H{sub 12}){sub 1.5}(Co{sub 0.6}Zn{sub 0.4}){sub 2}(HPO{sub 4}){sub 2}(PO{sub 4})·H{sub 2}O (2D), have been reported. The crystal structure of a one-dimensional piperazinium cobalt–zinc phosphate, (C{sub 4}N{sub 2}H{sub 12})Co{sub 0.3}Zn{sub 0.7}(HPO{sub 4}){sub 2}·H{sub 2}O (1D) a metastable phase during the hydrothermal synthesis, was also determined. The thermal behavior of 2D compound is strongly dependent on the selected heating rate and the magnetic susceptibility and magnetization measurements show no magnetic ordering down to 4 K. - Highlights: • A 2D piperazinium cobalt–zinc phosphate has been synthesized and characterized. • Crystal

  18. Fluorescent nuclear track images of Ag-activated phosphate glass irradiated with photons and heavy charged particles

    Energy Technology Data Exchange (ETDEWEB)

    Kurobori, Toshio, E-mail: kurobori@staff.kanazawa-u.ac.jp [Graduate School of Natural Science and Technology, Kanazawa University, Kakuma, Kanazawa 920-1192 (Japan); Yanagida, Yuka [Oarai Research Center, Chiyoda Technol Corporation, Oarai-machi, Ibaraki 311-1313 (Japan); Kodaira, Satoshi [National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Shirao, Taichi [Nikon Instech Co., Ltd., Tanakanishi, Sakyo-ku, Kyoto 606-8221 (Japan)

    2017-05-21

    In this paper we report about the demonstration of the nuclear track imaging capabilities of Ag-activated phosphate glass. A 375 nm laser and confocal laser scanning microscopy (CLSM) were respectively used for track excitation and detection. Specifically, the blue and orange radiophotoluminescent (RPL) tracks and dose distributions observed after irradiation with soft X-rays, gamma rays and heavy charged particles (HCPs) are examined. In addition, the origins of the reductions in RPL efficiency for high-dose X-ray irradiation and for irradiation with HCPs with high linear energy transfer (LET) values are investigated via a CLSM and a conventional fluorescent reader and discussed. - Highlights: • 3D track images are demonstrated using a confocal laser microscopy. • Fluorescent track detectors are based on RPL Ag-doped phosphate glass. • The dose distributions are examined for X-ray, gamma ray and HCP irradiations. • The origins of the reduction in RPL efficiency are investigated and discussed.

  19. Fluorescent nuclear track images of Ag-activated phosphate glass irradiated with photons and heavy charged particles

    International Nuclear Information System (INIS)

    Kurobori, Toshio; Yanagida, Yuka; Kodaira, Satoshi; Shirao, Taichi

    2017-01-01

    In this paper we report about the demonstration of the nuclear track imaging capabilities of Ag-activated phosphate glass. A 375 nm laser and confocal laser scanning microscopy (CLSM) were respectively used for track excitation and detection. Specifically, the blue and orange radiophotoluminescent (RPL) tracks and dose distributions observed after irradiation with soft X-rays, gamma rays and heavy charged particles (HCPs) are examined. In addition, the origins of the reductions in RPL efficiency for high-dose X-ray irradiation and for irradiation with HCPs with high linear energy transfer (LET) values are investigated via a CLSM and a conventional fluorescent reader and discussed. - Highlights: • 3D track images are demonstrated using a confocal laser microscopy. • Fluorescent track detectors are based on RPL Ag-doped phosphate glass. • The dose distributions are examined for X-ray, gamma ray and HCP irradiations. • The origins of the reduction in RPL efficiency are investigated and discussed.

  20. Applicability of iron phosphate glass medium for loading NaCl originated from seawater used for cooling the stricken power reactors

    International Nuclear Information System (INIS)

    Amamoto, Ippei; Kobayashi, Hidekazu; Yokozawa, Takuma; Yamashita, Teruo; Nagai, Takayuki; Kitamura, Naoto; Takebe, Hiromichi; Mitamura, Naoki; Tsuzuki, Tatsuya

    2013-01-01

    As the part of investigation for immobilization of the sludge as one of the radioactive wastes arising from the treatment of contaminated water at Fukushima Dai-ichi nuclear power plant, applicability of vitrification method has been evaluated as a candidate technique. The aim of this study is to evaluate the influence of NaCl as one of the main constituents of sludge, on glass formation and glass properties. Two kinds of iron phosphate glass (IPG) media in the xFe 2 O 3 -(100-x)P 2 O 5 , with x=30 and 35 (mol%) were chosen and the glass formation, structure and properties including density, coefficient of thermal expansion, glass transition temperature, onset crystallization temperature and chemical durability of NaCl-loaded IPG were studied. The results are summarized as follows. Sodium chloride, NaCl could be loaded into IPG medium as Na 2 O and Cl contents and their loading ratio could be up to 19 and 15 mol%, respectively. Majority of Cl content of raw material NaCl was thought to be volatilized during glass melting. Loading NaCl into IPG induces to de-polymerize glass network of phosphate chains, leads to decrease both glass transition and onset crystallization temperatures, and to increase coefficient of thermal expansion. NaCl-loaded IPG indicated good chemical durability in case of using 35Fe 2 O 3 - 65P 2 O 5 medium. (authors)

  1. Mixed mobile ion effect in fluorozincate glasses

    International Nuclear Information System (INIS)

    Ghosh, S; Ghosh, A

    2005-01-01

    The mixed mobile ion effect has been investigated for the first time in zinc fluoride glasses where in addition to alkali cations fluorine anions also participate in the diffusion process, unlike mixed alkali oxide glasses. The minimum in the conductivity, conductivity relaxation frequency, crossover frequency and decoupling index indicates the existence of the mixed mobile ion effect in these fluoride glasses. It has been observed that the non-exponential parameter and the frequency exponent are independent of temperature. It has been established that alkali ions and fluorine anions exhibit lower dimensionality of the conduction pathways in mixed alkali zinc fluoride glasses than that in the single alkali lithium based zinc fluoride glasses while they are migrating. From the scaling of the conductivity spectra, it has been established that the relaxation dynamics in mixed alkali zinc fluoride glasses is independent of temperature and composition

  2. Structural and luminescence properties of Sm3+ -doped bismuth phosphate glass for orange-red photonic applications.

    Science.gov (United States)

    Damodaraiah, S; Reddy Prasad, V; Ratnakaram, Y C

    2018-05-01

    In the present study, the effect of bismuth oxide (Bi 2 O 3 ) content on the structural and optical properties of 0.5Sm 3+ -doped phosphate glass and the effect of concentration on structural and optical properties of Sm 3+ -doped bismuth phosphate (BiP) glass were studied. Structural characterization was accomplished using X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), Fourier transform infrared (FTIR) spectroscopy and 31 P nuclear magnetic resonance (NMR) spectroscopy. Optical properties were studied using absorption, photoluminescence and decay measurements. Using optical absorption spectra, Judd-Ofelt parameters were derived to determine the local structure and bonding in the vicinity of Sm 3+ ions. The emission spectra of Sm 3+ -doped BiP glass showed two intense emission bands, 4 G 5/2 → 6 H 7/2 (orange) and 4 G 5/2 → 6 H 9/2 (red) for which the stimulated emission cross-sections (σ e ) and branching ratios (β) were found to be higher. The quantum efficiencies were also calculated from decay measurements recorded for the 4 G 5/2 level of Sm 3+ ions. The suitable combination of Bi 2 O 3 (10 mol%) and Sm 3+ (0.5 mol%) ions in these glasses acted as an efficient lasing material and might be suitable for the development of visible orange-red photonic materials. Copyright © 2018 John Wiley & Sons, Ltd.

  3. Magnesium Coated Bioresorbable Phosphate Glass Fibres: Investigation of the Interface between Fibre and Polyester Matrices

    Directory of Open Access Journals (Sweden)

    Xiaoling Liu

    2013-01-01

    Full Text Available Bioresorbable phosphate glass fibre reinforced polyester composites have been investigated as replacement for some traditional metallic orthopaedic implants, such as bone fracture fixation plates. However, composites tested revealed loss of the interfacial integrity after immersion within aqueous media which resulted in rapid loss of mechanical properties. Physical modification of fibres to change fibre surface morphology has been shown to be an effective method to improve fibre and matrix adhesion in composites. In this study, biodegradable magnesium which would gradually degrade to Mg2+ in the human body was deposited via magnetron sputtering onto bioresorbable phosphate glass fibres to obtain roughened fibre surfaces. Fibre surface morphology after coating was observed using scanning electron microscope (SEM. The roughness profile and crystalline texture of the coatings were determined via atomic force microscope (AFM and X-ray diffraction (XRD analysis, respectively. The roughness of the coatings was seen to increase from 40±1 nm to 80±1 nm. The mechanical properties (tensile strength and modulus of fibre with coatings decreased with increased magnesium coating thickness.

  4. Spectroscopic and radiative properties study of Nd3+ doped cadmium-phosphate glasses

    International Nuclear Information System (INIS)

    Mahmoud, K.H.

    2010-01-01

    A spectroscopic investigation is performed on Nd 3+ doped cadmium-phosphate glasses. The Judd-Ofelt analysis is applied to the glass system in order to evaluate their potential as both glass laser and amplifier materials. The phenomenological Judd-Ofelt parameters Ω (2) , Ω (4) , and Ω (6) are determined, their values are 4.80x10 -20 , 6.18x10 -20 , and 7.14x10 -20 cm -2 , respectively. The quality factor for glass system is 0.86. Predicted radiative decay rates and branching ratios of transitions from Nd 3+4 F 3/2 state to the 4 I J manifolds are determined and analyzed. The calculated lifetime of the 4 F 3/2 metastable state of Nd 3+ is 31 μs. The results showed that 4 F 3/2 to 4 I 11/2 transition, with fluorescence at 1056 nm, has the most potential for laser application. Photoluminescence up-conversion under excitation at 488 nm laser light exhibits three emission bands of Nd 3+ ions at 541 (green), 601 (orange), and 677 nm (red). These emission bands are assigned to 4 G 7/2 → 4 I 9/2 , 4 G 7/2 → 4 I 11/2 , and 4 G 7/2 → 4 I 13/2 transitions, respectively. Analysis of luminescence spectra enhances the use of glass system in optical displays, lasers, and optical memory devices.

  5. Novel resorbable glass-ceramic scaffolds for hard tissue engineering: from the parent phosphate glass to its bone-like macroporous derivatives.

    Science.gov (United States)

    Bretcanu, Oana; Baino, Francesco; Verné, Enrica; Vitale-Brovarone, Chiara

    2014-05-01

    One of the major challenges of hard tissue engineering research focuses on the development of scaffolds that can match the mechanical properties of the host bone and resorb at the same rate as the bone is repaired. The aim of this work was the synthesis and characterization of a resorbable phosphate glass, as well as its application for the fabrication of three dimensional (3-D) scaffolds for bone regeneration. The glass microstructure and behaviour upon heating were analysed by X-ray diffraction, differential scanning calorimetry and hot stage microscopy. The glass solubility was investigated according to relevant ISO standards using distilled water, simulated body fluid (SBF) and Tris-HCl as testing media. The glass underwent progressive dissolution over time in all three media but the formation of a hydroxyapatite-like layer was also observed on the samples soaked in SBF and Tris-HCl, which demonstrated the bioactivity of the material. The glass powder was used to fabricate 3-D macroporous bone-like glass-ceramic scaffolds by adopting polyethylene particles as pore formers: during thermal treatment, the polymer additive was removed and the sintering of glass particles was allowed. The obtained scaffolds exhibited high porosity (87 vol.%) and compressive strength around 1.5 MPa. After soaking for 4 months in SBF, the scaffolds mass loss was 76 wt.% and the pH of the solution did not exceed the 7.55 value, thereby remaining in a physiological range. The produced scaffolds, being resorbable, bioactive, architecturally similar to trabecular bone and exhibiting interesting mechanical properties, can be proposed as promising candidates for bone repair applications.

  6. Steric Effects on the Binding of Phosphate and Polyphosphate Anions by Zinc(II) and Copper(II) Dinuclear Complexes of m-Xylyl-bis-cyclen.

    Science.gov (United States)

    Esteves, Catarina V; Esteban-Gómez, David; Platas-Iglesias, Carlos; Tripier, Raphaël; Delgado, Rita

    2018-05-11

    The triethylbenzene-bis-cyclen (cyclen = 1,4,7,10-tetraazacyclododecane) compound (tbmce) was designed with an imposed structural rigidity at the m-xylyl spacer to be compared to a less restrained and known parent compound (bmce). The framework of both compounds differs only in the substituents of the m-xylyl spacer. The study was centered in the differences observed in the acid-base reactions of both compounds, their copper(II) and zinc(II) complexation behaviors, as well as in the uptake of phosphate and polyphosphate anions (HPPi 3- , ATP 4- , ADP 3- , AMP 2- , PhPO 4 2- , and HPO 4 2- ). On the one hand, the acid-base reactions showed lower values for the third and fourth protonation constants of tbmce than for bmce, suggesting that the ethyl groups of the spacer in tbmce force the two cyclen units to more conformational restricted positions. On the other hand, the stability constant values for copper(II) and zinc(II) complexes revealed that bmce is a better chelator than tbmce pointing out to additional conformational restraints imposed by the triethylbenzene spacer. The binding studies of phosphates by the dinuclear copper(II) and zinc(II) complexes showed much smaller effective association constants for the dicopper complexes. Single-crystal X-ray and computational (density functional theory) studies suggest that anion binding promotes the formation of tetranuclear entities in which anions are bridging the metal centers. Our studies also revealed the dinuclear zinc(II) complex of bmce as a promising receptor for phosphate anions, with the largest effective association constant of 5.94 log units being observed for the formation of [Zn 2 bmce(HPPi)] + . Accordingly, a colorimetric study via an indicator displacement assay to detect phosphates in aqueous solution found that the [Zn 2 bmce] 4+ complex acts as the best receptor for pyrophosphate displaying a detection limit of 2.5 nM by changes visible to naked eye.

  7. Iron phosphate glass: a promising matrix for the immobilization of Cs and Mo

    International Nuclear Information System (INIS)

    Hemadevi, V.; Joseph, Kitheri

    2015-01-01

    Presently, borosilicate glass (BSG) is the acceptable vitrification matrix for the immobilization of high level waste. The solubility of Mo in BSG is limited in the presence of Cs. As per the literature, solubility of Mo in BSG is about 2.5 wt. % in the presence of Cs. Hence it is difficult to immobilize nuclear waste rich in Cs and Mo in borosilicate glass. It is observed that the composition of Cs and Mo expressed as oxides are 10.4 and 14.7 wt. % respectively in simulated fast reactor waste. Iron phosphate glass containing 20 wt. % simulated fast reactor waste (referred as IP20FRW) was synthesized and characterized. IP20FRW contains ~ 3 wt. % of molybdenum oxide along with 2 wt. % cesium oxide. IPG is a suitable matrix for the immobilization of Cs and Mo separately. Hence it is essential to understand the glass characteristics of IPG containing both Cs and Mo. This paper explores systematic loading of both Cs and Mo such that the final composition corresponds to 10.5 wt. % Cs 2 O-15 wt. % MoO 3 -31.9 wt. % Fe 2 O 3 -42.6 wt. % P 2 O 5 . In addition to synthesis, the present study also includes understanding the change in glass characteristics of IPG containing both Cs and Mo. The possibility of higher percent loading of both Cs and Mo in IPG demonstrates the better glass forming characteristics of IPG. The synthesis and characterization of Cs-Mo loaded glasses will be discussed in this paper. (author)

  8. Role of glass structure in defining the chemical dissolution behavior, bioactivity and antioxidant properties of zinc and strontium co-doped alkali-free phosphosilicate glasses.

    Science.gov (United States)

    Kapoor, Saurabh; Goel, Ashutosh; Tilocca, Antonio; Dhuna, Vikram; Bhatia, Gaurav; Dhuna, Kshitija; Ferreira, José M F

    2014-07-01

    We investigated the structure-property relationships in a series of alkali-free phosphosilicate glass compositions co-doped with Zn(2+) and Sr(2+). The emphasis was laid on understanding the structural role of Sr(2+) and Zn(2+) co-doping on the chemical dissolution behavior of glasses and its impact on their in vitro bioactivity. The structure of glasses was studied using molecular dynamics simulations in combination with solid state nuclear magnetic resonance spectroscopy. The relevant structural properties are then linked to the observed degradation behavior, in vitro bioactivity, osteoblast proliferation and oxidative stress levels. The apatite-forming ability of glasses has been investigated by X-ray diffraction, infrared spectroscopy and scanning electron microscopy-energy-dispersive spectroscopy after immersion of glass powders/bulk in simulated body fluid (SBF) for time durations varying between 1h and 14 days, while their chemical degradation has been studied in Tris-HCl in accordance with ISO 10993-14. All the glasses exhibit hydroxyapatite formation on their surface within 1-3h of their immersion in SBF. The cellular responses were observed in vitro on bulk glass samples using human osteosarcoma MG63 cell line. The dose-dependent cytoprotective effect of glasses with respect to the concentration of zinc and strontium released from the glasses is also discussed. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  9. Zinc-phosphate nanoparticles with reversibly attached TNF-α analogs: an interesting concept for potential use in active immunotherapy

    International Nuclear Information System (INIS)

    Hribar, Gorazd; Žnidaršič, Andrej; Bele, Marjan; Maver, Uroš; Caserman, Simon; Gaberšček, Miran; Gaberc-Porekar, Vladka

    2011-01-01

    The authors’ intention was to prepare nanometer-sized zinc-phosphate nanoparticles that would be capable of binding histidine-rich TNF-α analogs onto their surface via a coordinative bond. Zinc-phosphate nanoparticles with a size of around 60 nm were prepared by a wet precipitation method and characterized using SEM, EDX, XRD, and DLS. First, BSA was bound as a testing protein, afterward two TNF-α analogs with decreased activity were bound to the described nanoparticles. The efficiency of binding and the existence of coordinative bond were confirmed with SDS-PAGE analysis. During binding, particle storage, and release experiments, the prepared TNF-α analogs retained their biological activity—hence the epitopes necessary for formation of antibodies stayed intact. The particle size did not change within a period of 2 weeks. No significant agglomeration was observed, the particles could be quickly dispersed in ultrasound. The present nanoparticles and the general approach of coordinative binding are widely applicable for natural and engineered histidine-rich proteins. The nanoparticles bearing appropriate TNF-α analogs could also be potentially used for active immunotherapy to tackle the chronic inflammatory diseases associated with pathogenically elevated levels of TNF-α.

  10. Effect of the addition of Na2O on the thermal properties and chemical durability of glasses of iron and uranium phosphates

    International Nuclear Information System (INIS)

    Arboleda Zuluaga, P.A; Rodriguez, D.S; Gonzalez Oliver, C; Rincon Lopez, J.M; Soldera, F

    2012-01-01

    A series of glass compositions including (54,6-73,5P 2 O 5 .14-22Fe 2 O 3.x Na 2 O.2,8-4,25 UO 2 ) %mol. x=0-28,4 were studied in function of sodium oxide content for the thermal properties and chemical durability. By means differential dilatometer measurements was possible establish the variation of Tg, and α Tsoft and analysis of the kinetics of sintering by means of High Temperature Microscopy (MAT) and dilatometric data of pressed pellets. The presence of modifier oxides in the structure of iron phosphate glasses causes slightly onset sintering anticipation in almost 25 o C The chemical durability was estimated performing the named Product Consistency Test (PCT-B) focused on determining the resistance of glasses for nuclear wastes. These glasses exhibit good chemical durability but it is significant impaired by the addition of x≥6wt%Na 2 O. It is aimed to achieve more stable compositions and get glass matrixes able to contain more uranium oxides allowing evaluating the potential application of these iron phosphate glasses for special, industrial and nuclear waste immobilization

  11. Characterization of Porous Phosphate Coatings Enriched with Magnesium or Zinc on CP Titanium Grade 2 under DC Plasma Electrolytic Oxidation

    Directory of Open Access Journals (Sweden)

    Krzysztof Rokosz

    2018-02-01

    Full Text Available The aim of the paper is to study and determine the effect of voltage increasing from 500 up to 650 VDC on chemical and electrochemical properties of the obtained porous coatings with plasma electrolytic oxidation (PEO processes, known also as micro arc oxidation (MAO. In the present paper, the chemical and electrochemical characterization of porous phosphate coatings enriched with magnesium or zinc on commercially pure (CP Titanium Grade 2 under DC-PEO obtained in electrolytes based on concentrated 85% analytically pure H3PO4 (98 g/mole acid with additions of 500 g·L−1 of zinc nitrate Zn(NO32∙6H2O or magnesium nitrate Mg(NO32∙6H2O, are described. These materials were characterized using scanning electron microscope (SEM with energy-dispersive X-ray spectroscopy (EDS, X-ray photoelectron spectroscopy (XPS and glow discharge optical emission spectroscopy (GDOES. It was found that the voltage of PEO process has influence on the chemical composition and thickness of the obtained porous coatings as well as on their electrochemical behavior. The higher the potential of PEO treatment, the higher the amount of zinc-to-phosphorus ratio for zinc enriched coatings was obtained, whereas in magnesium enriched coatings, the average amount of magnesium detected in PEO coating is approximately independent of the PEO voltages. Based on XPS studies, it was found out that most likely the top 10 nm of porous coatings is constructed of titanium (Ti4+, magnesium (Mg2+, zinc (Zn2+, and phosphates PO43− and/or HPO42− and/or H2PO4− and/or P2O74−. On the basis of GDOES studies, a four-sub-layer model of PEO coatings is proposed. Analysis of the potentiodynamic corrosion curves allowed to conclude that the best electrochemical repeatability was noted for magnesium and zinc enriched coatings obtained at 575 VDC.

  12. Application of Cu{sub 2}O-doped phosphate glasses for bandpass filter

    Energy Technology Data Exchange (ETDEWEB)

    Elhaes, H. [Physics Department, Faculty of Women for Arts, Science and Education, Ain Shams University, 11757 Cairo (Egypt); Attallah, M., E-mail: m_atallah94@yahoo.com [Basic Science Department, Higher Technological Institute, 10th of Ramadan City (Egypt); Elbashar, Y.; El-Okr, M. [Physics Department, Faculty of Science, Al Azhar University, Cairo (Egypt); Ibrahim, M. [Spectroscopy Department, National Research Centre, 12311 Dokki, Cairo (Egypt)

    2014-09-15

    Phosphate glasses doped with copper ions having general composition 42P{sub 2}O{sub 5}–39ZnO–(18−x) Na{sub 2}O–1CaO–xCu{sub 2}O [x=2, 4, 6, 8, 10 mol%] were prepared using a conventional melt-quench technique. Physical and chemical properties of the glasses were investigated using X-ray diffraction technique and UV–visible optical absorption. The density was measured by Archimedes' method, and molar volume (V{sub M}) was calculated. It is found that density and molar volume show opposite trend by increasing Cu{sub 2}O content. Absorbance and transmittance at the normal incidence are measured by a spectrophotometer in the spectral range of 190–1100 nm. Analyses of the obtained results were considered in the frame of current theories. Absorption data were used for absorption coefficient, the optical band gap (E{sub opt}), the cutoff in UV and IR bands to the bandpass filter, which confirmed the optical properties of this type of filter. E{sub opt} values for different glass samples are found to decrease with increasing Cu{sub 2}O content.

  13. Effect of incorporation of zinc oxide nanoparticles on mechanical properties of conventional glass ionomer cements.

    Science.gov (United States)

    Panahandeh, Narges; Torabzadeh, Hassan; Aghaee, Mohammadamin; Hasani, Elham; Safa, Saeed

    2018-01-01

    The aim of this study is to investigate the physical properties of conventional and resin-modified glass ionomer cements (GICs) compared to GICs supplemented with zinc oxide (ZnO) nanofiller particles at 5% (w/w). In this in vitro study, ZnO nanoparticles of different morphologies (nanospherical, nanorod, and nanoflower) were incorporated to glass ionomer powder. The samples were subjected to the flexural strength ( n = 20) and surface hardness test ( n = 12) using a universal testing machine and a Vickers hardness machine, respectively. Surface analysis and crystal structure of samples were performed with scanning electron microscope and X-radiation diffraction, respectively. The data were analyzed using one-way ANOVA, Shapiro-Wilk, and Tukey's tests ( P glass ionomer containing nanoparticles was not significantly different from the control group ( P > 0.05). The surface hardness of the glass ionomer containing nanospherical or nanoflower ZnO was significantly lower than the control group ( P glass ionomer containing nanorod ZnO was not significantly different from the control group ( P = 0.868). Incorporation of nanospherical and nanoflower ZnO to glass ionomer decreased their surface hardness, without any changes on their flexural strength. Incorporation of nanorod ZnO particles caused no effect on the mechanical properties.

  14. Influence of samarium ions (Sm3+) on the optical properties of lithium zinc phosphate glasses

    Science.gov (United States)

    Shwetha, M.; Eraiah, B.

    2018-05-01

    New glass samples with composition xSm2O3-(15-x) Li2O-45ZnO-40P2O5, where x= 0, 0.1, 0.3 and 0.5 mol % are prepared by conventional melt-quenching method. X-ray Diffraction measurements were performed to confirm their amorphous nature. Densities of these glasses were measured by Archimedes method. Optical properties were studied using optical absorption spectra which was recorded at room temperature in the UV-Vis region. Electronic transitions specific to the rare earth ion were observed from the UV-Visible spectroscopy. Optical direct band gap and indirect band gap energies were measured and their values were found to be between 4.23-4.74 eV and 3.02-3.67 eV, respectively. Refractive index has been measured with respect to different concentrations of Sm2O3. Polaron radius, inter-nuclear distance, field strength, dielectric constant and polarizability of oxide ions have been calculated. Fluorescence spectroscopy measurements have been performed by excitation in the UV-Visible range, which resulted in the significant fluorescence peaks. The luminescence color of the glass system has been characterized using Commission International de l'Eclairage de France 1931 chromaticity diagram.

  15. Effect of natural and magnetic convections on the structure of electrodeposited zinc-nickel alloy

    Energy Technology Data Exchange (ETDEWEB)

    Levesque, A., E-mail: alexandra.levesque@univ-reims.fr [LACMDTI URCA, BP 1039, 51687 Reims Cedex2 (France); Chouchane, S. [Faculte des Sciences, Universite Badji Mokhtar, Annaba (Algeria); Douglade, J. [LACMDTI URCA, BP 1039, 51687 Reims Cedex2 (France); Rehamnia, R. [Faculte des Sciences, Universite Badji Mokhtar, Annaba (Algeria); Chopart, J.-P. [LACMDTI URCA, BP 1039, 51687 Reims Cedex2 (France)

    2009-06-30

    The effects of a magnetic field applied in a direction parallel or perpendicular to the cathode substrate plane, during electrodeposition process of Zn-Ni alloy have been investigated by means of chronoamperometric measurements, X-ray diffraction and EDX analysis. The modification of crystal orientation of the alloy by the superimposition of a high magnetic field is discussed for alloys with a content of nickel range 6-13 at%. Whatever the phase composition obtained without magnetic field, either {gamma}-Ni{sub 5}Zn{sub 21} or a mixture of the {gamma} and zinc phases, which depends on the concentration of Ni{sup 2+} in the electrolyte bath, the preferential orientation (1 0 1) of the zinc phase is always favoured with perpendicular and parallel magnetic field. There is no saturation of this effect with amplitude of B up to 8 T. A study of different geometric configurations of the cathode, which induce more or less natural convection, consolidates these results. The structural modifications of Zn-Ni alloy electrodeposits are thus probably due to a magnetohydrodynamic effect. An additional phenomenon is observed in presence of a perpendicular applied magnetic field since the (3 3 0) preferential orientation of the {gamma}-Ni{sub 5}Zn{sub 21} disappears with high values of B.

  16. Effect of natural and magnetic convections on the structure of electrodeposited zinc-nickel alloy

    International Nuclear Information System (INIS)

    Levesque, A.; Chouchane, S.; Douglade, J.; Rehamnia, R.; Chopart, J.-P.

    2009-01-01

    The effects of a magnetic field applied in a direction parallel or perpendicular to the cathode substrate plane, during electrodeposition process of Zn-Ni alloy have been investigated by means of chronoamperometric measurements, X-ray diffraction and EDX analysis. The modification of crystal orientation of the alloy by the superimposition of a high magnetic field is discussed for alloys with a content of nickel range 6-13 at%. Whatever the phase composition obtained without magnetic field, either γ-Ni 5 Zn 21 or a mixture of the γ and zinc phases, which depends on the concentration of Ni 2+ in the electrolyte bath, the preferential orientation (1 0 1) of the zinc phase is always favoured with perpendicular and parallel magnetic field. There is no saturation of this effect with amplitude of B up to 8 T. A study of different geometric configurations of the cathode, which induce more or less natural convection, consolidates these results. The structural modifications of Zn-Ni alloy electrodeposits are thus probably due to a magnetohydrodynamic effect. An additional phenomenon is observed in presence of a perpendicular applied magnetic field since the (3 3 0) preferential orientation of the γ-Ni 5 Zn 21 disappears with high values of B.

  17. Improved ionic conductivity of lithium-zinc-tellurite glass-ceramic electrolytes

    Science.gov (United States)

    Widanarto, W.; Ramdhan, A. M.; Ghoshal, S. K.; Effendi, M.; Cahyanto, W. T.; Warsito

    An enhancement in the secondary battery safety demands the optimum synthesis of glass-ceramics electrolytes with modified ionic conductivity. To achieve improved ionic conductivity and safer operation of the battery, we synthesized Li2O included zinc-tellurite glass-ceramics based electrolytes of chemical composition (85-x)TeO2·xLi2O·15ZnO, where x = 0, 5, 10, 15 mol%. Samples were prepared using the melt quenching method at 800 °C followed by thermal annealing at 320 °C for 3 h and characterized. The effects of varying temperature, alternating current (AC) frequency and Li2O concentration on the structure and ionic conductivity of such glass-ceramics were determined. The SEM images of the annealed glass-ceramic electrolytes displayed rough surface with a uniform distribution of nucleated crystal flakes with sizes less than 1 μm. X-ray diffraction analysis confirmed the well crystalline nature of achieved electrolytes. Incorporation of Li2O in the electrolytes was found to generate some new crystalline phases including hexagonal Li6(TeO6), monoclinic Zn2Te3O8 and monoclinic Li2Te2O5. The estimated crystallite size of the electrolyte was ranged from ≈40 to 80 nm. AC impedance measurement revealed that the variation in the temperatures, Li2O contents, and high AC frequencies have a significant influence on the ionic conductivity of the electrolytes. Furthermore, electrolyte doped with 15 mol% of Li2O exhibited the optimum performance with an ionic conductivity ≈2.4 × 10-7 S cm-1 at the frequency of 54 Hz and in the temperature range of 323-473 K. This enhancement in the conductivity was attributed to the sizable alteration in the ions vibration and ruptures of covalent bonds in the electrolytes network structures.

  18. Investigations on optical properties of Sm{sup 3+} ion doped boro-phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Vijayakumar, R.; Suthanthirakumar, P.; Karthikeyan, P.; Marimuthu, K., E-mail: mari-ram2000@yahoo.com [Department of Physics, Gandhigram Rural Institute – Deemed University, Gandhigram – 624302 (India)

    2015-06-24

    The Sm{sup 3+} doped Boro-phosphate glasses with the chemical composition 60H{sub 3}BO{sub 3}+20Li{sub 2}CO{sub 3}+10ZnO+(10−x) H{sub 6}NO{sub 4}P+xSm{sub 2}O{sub 3} (where x= 0.1, 0.5, 1 and 2 in wt%) have been prepared by melt quenching technique. The prepared glasses were characterized through optical absorption and luminescence spectral measurements. The band gap energies corresponding to the direct and indirect allowed transitions and the Urbach’s energy values were estimated from the absorption spectra. Judd-Ofelt intensity parameters have been derived to predict the radiative properties of the various emission transitions. In order to identify the emission color of the prepared glasses, the emission intensities were analyzed using CIE 1931 color chromaticity diagram. The energy transfer process takes place between Sm{sup 3+}−Sm{sup 3+} ions through cross-relaxation mechanism have also been investigated and the results were discussed and reported.

  19. Effect of PbO on the elastic behavior of ZnO–P2O5 glass systems

    Directory of Open Access Journals (Sweden)

    H.A.A. Sidek

    Full Text Available A series of ternary phosphate glasses in the form of 40(P2O5–(60 − xZnO–xPbO and 50(P2O5–(50 − xZnO–xPbO where x = 0–60 mol%, have been successfully prepared by conventional melt quenching technique. Both longitudinal and shear ultrasonic velocities were measured in different compositions of PbO using the MBS8000 ultrasonic data acquisition system at 10 MHz frequency and at room temperature. The ultrasonic velocity data, the density and the calculated elastic moduli are found to be composition dependent and discussed in terms of PbO modifiers. The correlation of elastic moduli with the atomic packing density of these glasses was discussed. To predict the compositional dependence of elastic moduli of this glass system, the interpretation of the variation in the experimental elastic behavior observed has been studied based on various of the bond compression and the Makishima–Mackenzie models. Keywords: Elastic moduli, Glasses, Zinc phosphate, Bond compression, Makishima–Mackenzie models

  20. Silver-zinc: status of technology and applications

    Energy Technology Data Exchange (ETDEWEB)

    Karpinski, A.P.; Makovetski, B.; Russell, S.J.; Serenyi, J.R.; Williams, D.C. [Yardney Technical Products, Pawcatuck, CT (United States)

    1999-07-01

    Michel Yardney and Professor Henri Andre developed the first practical silver-zinc battery more than 55 years ago. Since then, primary and rechargeable silver-zinc batteries have attracted a variety of applications due to their high specific energy/energy density, proven reliability and safety, and the highest power output per unit weight and volume of all commercially available batteries. Although significant improvements have been achieved on traditional systems such as lead-acid and nickel/cadmium, and in spite of the advent of new electrochemistries such as lithium-ion and nickel/metal hydride, many users still rely on silver-zinc to satisfy their most demanding and critical requirements. Over the past few years, several of the internal components have been subject to many studies which resulted in significant improvements in the battery wet life and cycle life. Specifically, these include new separator materials which offer an alternative to the cellulosic membranes, improvements to the zinc electrode that include additives that help reduce shape-change and dendritic growth, and to a lesser extent, process changes to the silver electrode and additives to the electrolyte. In comparison, the commonly used secondary systems are lead-acid, nickel/cadmium, nickel/metal hydride, and lithium-ion. Each has attributes which make them desirable for certain applications. Where low cost, high voltage, and high rate capability is required, the lead-acid battery is an obvious choice whenever size and weight are not critical. For applications requiring longer wet life, moderate rate capability, and high cycle life, nickel/cadmium or nickel/metal hydride can be used in spite of their poor charge retention and higher costs. Relatively newer systems are also available such as lithium-ion or lithium polymer technology which are preferred for their high voltage and excellent cycle life. Among the disadvantages of these systems are higher costs, limited configurations (usually

  1. Phosphate glass fibre scaffolds: Tailoring of the properties and enhancement of the bioactivity through mesoporous glass particles.

    Science.gov (United States)

    Novajra, G; Boetti, N G; Lousteau, J; Fiorilli, S; Milanese, D; Vitale-Brovarone, C

    2016-10-01

    Novel bone glass fibre scaffolds were developed by thermally bonding phosphate glass fibres belonging to the P2O5-CaO-Na2O-SiO2-MgO-K2O-TiO2 system (TiPS2.5 glass). Scaffolds with fibres of 85 or 110μm diameter were fabricated, showing compressive strength in the range of 2-3.5MPa, comparable to that of the trabecular bone. The effect of different thermal treatments and fibre diameters and length on the final scaffold structure was investigated by means of micro-CT analysis. The change of the sintering time from 30 to 60min led to a decrease in the scaffold overall porosity from 58 to 21vol.% for the 85μm fibre scaffold and from 50 to 40vol.% when increasing the sintering temperature from 490 to 500°C for the 110μm fibre scaffold. The 85μm fibres resulted in an increase of the scaffold overall porosity, increased pore size and lower trabecular thickness; the use of different fibre diameters allowed the fabrication of a scaffold showing a porosity gradient. In order to impart bioactive properties to the scaffold, for the first time in the literature the introduction in these fibre scaffolds of a bioactive phase, a melt-derived bioactive glass (CEL2) powder or spray-dried mesoporous bioactive glass particles (SD-MBG) was investigated. The scaffold bioactivity was assessed through soaking in simulated body fluid. CEL2/glass fibre scaffold did not show promising results due to particle detachment from the fibres during soaking in simulated body fluid. Instead the use of mesoporous bioactive powders showed to be an effective way to impart bioactivity to the scaffold and could be further exploited in the future through the ability of mesoporous particles to act as systems for the controlled release of drugs. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. The effects to the structure and electrochemical behavior of zinc phosphate conversion coatings with ethanolamine on magnesium alloy AZ91D

    International Nuclear Information System (INIS)

    Li Qing; Xu Shuqiang; Hu Junying; Zhang Shiyan; Zhong Xiankang; Yang Xiaokui

    2010-01-01

    This paper discussed a zinc phosphate conversion coating formed on magnesium alloy AZ91D from the phosphating bath with varying amounts of ethanolamine (MEA). The effects of MEA on the form, structure, phase composition and electrochemical behavior of the phosphate coatings were examined using an scanning electron microscopy (SEM), X-ray diffraction (XRD) potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS) measurements. Interpretations of the electrical elements of the equivalent circuit were obtained from the SEM structure of the coatings, assumed to be formed of two layers: an outer porous crystal layer and an inner flat amorphous layer. The result showed that adding MEA refined the microstructure of the crystal layer and that the phosphate coating, derived at the optimal content of 1.2 g/L, with the most uniform and compact outer crystal layer provided the best corrosion protection.

  3. Structural characterizations and optical properties of new Li–Sr–Nb-phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yi-Mu [Department of Electronic Engineering, National United University, Miao-Li 36003, Taiwan, ROC (China); Hsu, S.M. [Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei 11221, Taiwan, ROC (China); Yung, S.W., E-mail: hwyang@nuu.edu.tw [Department of Material Science and Engineering, National United University, Miao-Li 36003, Taiwan, ROC (China); Zhang, T. [Institute for Materials Research, Fuzhou University, Fujian (China); Huang, Y.S.; Wu, J.J. [Department of Material Science and Engineering, National United University, Miao-Li 36003, Taiwan, ROC (China); Hsu, C.H. [Department of Electrical Engineering, National United University, Miao-Li 36003, Taiwan, ROC (China); Chin, T.S. [Department of Materials Science and Engineering, Feng Chia University, Taichung, Taiwan, ROC (China)

    2014-04-01

    A new Li{sub 2}O–SrO–Nb{sub 2}O{sub 5}–P{sub 2}O{sub 5} glass system was prepared by a high-temperature alumina crucible, and structural characterization and optical properties were investigated. Proper content of Li{sub 2}O and Nb{sub 2}O{sub 5} was employed to replace partial SrO and P{sub 2}O{sub 5} to improve the optical properties. It was observed that the enhancement of the refractive index from 1.75 to 1.85 is mainly due to the Nb{sub 2}O{sub 5} content. An addition of Li{sub 2}O significantly increases the optical transmittance; optical transparency can be enhanced from 60% to higher than 85% in the UV–visible region with addition of 20–40 mol% Li{sub 2}O species. However, optical transmittance is monotonically decreased from about 90% to 80% under 10–30 mol% Nb{sub 2}O{sub 5} addition. The 40P{sub 2}O{sub 5}–20Nb{sub 2}O{sub 5}–20SrO–20Li{sub 2}O glasses demonstrate the optimum refractive index (n > 1.75) and high optical transparency (>80%) in the UV–visible region. Furthermore, the effect of Nb{sub 2}O{sub 5} on the structural transition was focused on the (60 − y)P{sub 2}O{sub 5}–yNb{sub 2}O{sub 5}–20SrO–20Li{sub 2}O vitreous system since the transition of FTIR spectra reveals that the Nb{sub 2}O{sub 5} has more pronounced effect than Li{sub 2}O in the glass network due to the higher covalent extent and electronegativity. Addition of Nb{sub 2}O{sub 5} generates Nb–O bonds by dissociating P–O chains and results in the decrease in the intensity of the (PO{sub 2}), (POP), and (PO{sub 3}) absorption bands. The O1s-XPS analysis shows that Nb{sub 2}O{sub 5} addition dissociates symmetric bridging oxygens in P–O–P bonding and forms asymmetric bridging oxygens in P–O–Nb and non-bridging Nb–O{sup -} bonds, in which octahedral [NbO{sub 6}] unit is eventually substituted by [NbO{sub 4}] tetrahedral unit in the Li–Sr–Nb phosphate glasses. - Highlights: • The prepared glasses demonstrate great optical properties

  4. Effect of ultrasonic instrumentation on the bond strength of crowns cemented with zinc phosphate cement to natural teeth. An in vitro study

    Directory of Open Access Journals (Sweden)

    Antonio Braulino de Melo Filho

    2008-09-01

    Full Text Available Several studies have reported the benefits of sonic and/or ultrasonic instrumentation for root debridement, with most of them focusing on changes in periodontal clinical parameters. The present study investigated possible alterations in the tensile bond strength of crowns cemented with zinc phosphate cement to natural teeth after ultrasonic instrumentation. Forty recently extracted intact human third molars were selected, cleaned and stored in physiologic serum at 4°C. They received standard preparations, at a 16º convergence angle, and AgPd alloy crowns. The crowns were cemented with zinc phosphate cement and then divided into four groups of 10 teeth each. Each group was then subdivided into two subgroups, with one of the subgroups being submitted to 5,000 thermal cycles ranging from 55 ± 2 to 5 ± 2°C, while the other was not. Each group was submitted to ultrasonic instrumentation for different periods of time: group 1 - 0 min (control, group 2 - 5 min, group 3 - 10 min, and group 4 - 15 min. Tensile bond strength tests were performed with an Instron testing machine (model 4310. Statistical analysis was performed using ANOVA and Tukey's test at the 5% level of significance. A significant reduction in the tensile bond strength of crowns cemented with zinc phosphate and submitted to thermal cycles was observed at 15 min (196.75 N versus 0 min = 452.01 N, 5 min = 444.23 N and 10 min = 470.85 N. Thermal cycling and ultrasonic instrumentation for 15 min caused a significant reduction in tensile bond strength (p < .05.

  5. Leachates analysis of glass from black and white and color televisions sets

    Directory of Open Access Journals (Sweden)

    Radovan Kukla

    2012-01-01

    Full Text Available The aim of work was to determine the content of selected elements in the glass from color and black and white television (TV sets. The amount of back taken TV sets in the Czech Republic increases annualy, which is associated with higher production of the waste glass. Currently there is 1.4 television sets for each household and the number of it should increase in future, because of higher standard of living and new technologies used. Waste glass treatment or landfilling may present, because of composition of the waste glass threat to the environment. One of the indicators of the polution from waste glass is leachate analysis, which can show us the content of hazardous substances in the waste glass, which can be released to the environment. A qualitative analysis of leachate samples was carried out by UV-VIS spectrophotometer. The results showed concentration of potencionaly hazardous substances contained in leachate samples. This was especially content of aluminum, cadmium, chromium, copper, molybdenum, nickel, lead, tin and zinc. Results of analyzes of the aqueous extract of glass were confronted with the limits specified in the currently valid legislation. Based on the results there is clear that in the case of landfilling of the glass from television sets, there is possibility of the contamination of landfill leachate by the elements, which are presented in the glass.

  6. Glass formation and structure of calcium antimony phosphate glasses and those doped with tellurium oxide

    Science.gov (United States)

    Li, Jun; Zhang, Yin; Nian, Shangjiu; Wu, Zhenning; Cao, Weijing; Zhou, Nianying; Wang, Danian

    2017-03-01

    An approximate glass-forming region in the P2O5-Sb2O3-CaO ternary system was determined. The properties and structure of two compositional series of (A) (75- x)P2O5- xSb2O3-25CaO ( x = 20, 25, 30, 35 mol%) and (B) 45P2O5-30Sb2O3-(25- x)CaO- xTeO2 ( x = 5, 10, 15, 20 mol%) were studied systematically. Thermal properties were investigated by means of differential scanning calorimetry (DSC). The densities of all samples were measured by Archimedes' method using distilled water as the immersion liquid. The water durability of the glasses was described by their dissolution rate (DR) in the distilled water at 90 °C for some time periods. Density, thermal stability and water durability were improved with the addition of Sb2O3 and TeO2. Structural studies were carried out by X-ray diffraction (XRD), infrared spectroscopy and Raman spectroscopy. The phosphate chain depolymerization occurred with the increase of Sb2O3 and the Q2 structural units transformed to the Q1 and Q0 structural units with the addition of TeO2.

  7. Ductile polyelectrolyte macromolecule-complexed zinc phosphate conversion crystal pre-coatings and topcoatings embodying a laminate

    Science.gov (United States)

    Sugama, Toshifumi; Kukacka, Lawrence E.; Carciello, Neal R.

    1987-01-01

    This invention relates to a precoat, laminate, and method for ductile coatings on steel and non-ferrous metals which comprises applying a zinc phosphating coating solution modified by a solid polyelectrolyte selected from polyacrylic acid (PAA), polymethacrylic acid (PMA), polyitaconic acid (PIA), and poly-L-glutamic acid. The contacting of the resin with the phosphating solution is made for a period of up to 20 hours at about 80.degree. C. The polyelectrolyte or the precoat is present in about 0.5-5.0% by weight of the total precoat composition and after application, the precoat base is dried for up to 5 hours at about 150.degree. C. to desiccate. Also, a laminate may be formed where polyurethane (PU) is applied as an elastomeric topcoating or polyfuran resin is applied as a glassy topcoating. It has been found that the use of PAA at a molecular weight of about 2.times.10.sup.5 gave improved ductility modulus effect.

  8. Towards modular bone tissue engineering using Ti-Co-doped phosphate glass microspheres: cytocompatibility and dynamic culture studies.

    Science.gov (United States)

    Peticone, Carlotta; De Silva Thompson, David; Owens, Gareth J; Kim, Hae-Won; Micheletti, Martina; Knowles, Jonathan C; Wall, Ivan

    2017-09-01

    The production of large quantities of functional vascularized bone tissue ex vivo still represent an unmet clinical challenge. Microcarriers offer a potential solution to scalable manufacture of bone tissue due to their high surface area-to-volume ratio and the capacity to be assembled using a modular approach. Microcarriers made of phosphate bioactive glass doped with titanium dioxide have been previously shown to enhance proliferation of osteoblast progenitors and maturation towards functional osteoblasts. Furthemore, doping with cobalt appears to mimic hypoxic conditions that have a key role in promoting angiogenesis. This characteristic could be exploited to meet the clinical requirement of producing vascularized units of bone tissue. In the current study, the human osteosarcoma cell line MG-63 was cultured on phosphate glass microspheres doped with 5% mol titanium dioxide and different concentrations of cobalt oxide (0%, 2% and 5% mol), under static and dynamic conditions (150 and 300 rpm on an orbital shaker). Cell proliferation and the formation of aggregates of cells and microspheres were observed over a period of two weeks in all glass compositions, thus confirming the biocompatibility of the substrate and the suitability of this system for the formation of compact micro-units of tissue. At the concentrations tested, cobalt was not found to be cytotoxic and did not alter cell metabolism. On the other hand, the dynamic environment played a key role, with moderate agitation having a positive effect on cell proliferation while higher agitation resulting in impaired cell growth. Finally, in static culture assays, the capacity of cobalt doping to induce vascular endothelial growth factor (VEGF) upregulation by osteoblastic cells was observed, but was not found to increase linearly with cobalt oxide content. In conclusion, Ti-Co phosphate glasses were found to support osteoblastic cell growth and aggregate formation that is a necessary precursor to tissue

  9. Zinc chloride modified electronic transport and relaxation studies in barium-tellurite glasses

    Science.gov (United States)

    Dhankhar, Sunil; Kundu, R. S.; Rani, Sunita; Sharma, Preeti; Murugavel, S.; Punia, Rajesh; Kishore, N.

    2017-09-01

    The ac conductivity of halide based tellurium glasses having composition 70 TeO2-(30-x) BaO-x ZnCl2; x = 5, 10, 15, 20 and 25 has been investigated in the frequency range 10-1 Hz to 105Hz and in the temperature range 453 K to 553 K. The frequency and temperature dependent ac conductivity show mixed behaviour with increase in halide content and found to obey Jonscher's universal power law. The values of dc conductivity, crossover frequency and frequency exponent have been estimated from the fitting of experimental data of ac conductivity with Jonscher's universal power law. For determining the conduction mechanism in studied glass system, frequency exponent has been analyzed by various theoretical models. In presently studied glasses, the ac conduction takes place via overlapping large polaron tunneling (OLPT). The values of activation energy for dc conduction (W) and the one associated with relaxation process ( E R) are found to increase with increase in x up to glass sample with x = 15 and thereafter it decrease with increase in zinc chloride content. DC conduction takes place via variable range hopping (VRH) as proposed by Mott with some modification suggested by Punia et al. The value of real part of modulus ( M') is observed to decrease with increase in temperature. The value of stretched exponent (β) obtained from fitting of M'' reveals the presence of non-Debye type of relaxation in presently studied glass samples. Scaling spectra of ac conductivity and values of electric modulus ( M' and M'') collapse into a single master curve for all the compositions and temperatures. The values of relaxation energy ( E R) for all the studied glass compositions are almost equal to W, suggesting that polarons have to overcome same barrier while relaxing and conducting. The conduction and relaxation processes in the studied glass samples are composition and temperature independent. [Figure not available: see fulltext.

  10. Raman and optical absorption spectroscopic investigation of Yb-Er codoped phosphate glasses containing SiO2

    Institute of Scientific and Technical Information of China (English)

    Youkuo Chen; Lei Wen; Lili Hu; Wei Chen; Y. Guyot; G. Boulon

    2009-01-01

    Yb-Er codoped Na2O-Al2O3-P2Os-xSiO2 glasses containing 0 鈥? 20 mol% SiO2 were prepared successfully. The addition of SiO2 to the phosphate glass not only lengthens the bond between P5+ and non-bridging oxygen but also reduces the number of P=O bond. In contrast with silicate glass in which there is only four-fold coordinated Si4+, most probably there coexist [SiO4] tetrahedron and [SiO6] octahedron in our glasses. Within the range of 0 鈥? 20 mol% SiO2 addition, the stimulated emission cross-section of Er3+ ion only decreases no more than 10%. The Judd-Ofelt intensity parameters of Er3+, 惟.2 does not change greatly, but 惟74 and 惟6 decrease obviously with increasing SiO2 addition, because the bond between Er + and O2- is more strongly covalently bonded.

  11. Corrosion and solubility in a TSP-buffered chemical environment following a loss of coolant accident: Part 2 – Zinc

    International Nuclear Information System (INIS)

    Pease, David; LaBrier, Daniel; Ali, Amir; Blandford, Edward D.; Howe, Kerry J.

    2016-01-01

    Highlights: • Zinc release is limited to less than 1 mg/L in TSP-buffered solution under a variety of conditions (pH, temperature, zinc source). • Zinc release in high-temperature non-TSP-buffered environment is approximately 25 mg/L. • Long-term zinc release is controlled by passivation (without TSP) and zinc solubility (with TSP). • Precipitation and solubility of zinc phosphate limit the release of zinc. - Abstract: Bench experiments were conducted to investigate the effect of the presence of trisodium phosphate (TSP) on the corrosion and release of zinc from metallic zinc-bearing surfaces under conditions representative of the containment pool following a postulated loss of coolant accident (LOCA) at a nuclear power generating facility. The experiments showed that in non-buffered (acidic) environments, measurable quantities of zinc are released from zinc-bearing surfaces. Precipitation and solubility of phosphate-based corrosion products, such as zinc phosphate, limit the release of zinc from zinc-bearing surfaces. These experiments have found that under a variety of conditions, including variations of temperature, pH, and across different zinc-bearing surfaces, the release of zinc into solution is limited to <1 mg/L when phosphate is present. When phosphate is not present, zinc release is instead bounded by a markedly higher saturation limit which is a strong function of the solution temperature.

  12. Surface characterization of the cement for retention of implant supported dental prostheses: In vitro evaluation of cement roughness and surface free energy

    Energy Technology Data Exchange (ETDEWEB)

    Brajkovic, Denis [Clinic for Dentistry, Department of Maxillofacial Surgery, Faculty of Medical Sciences, University of Kragujevac, Svetozara Markovica 69, 34000 Kragujevac (Serbia); Antonijevic, Djordje; Milovanovic, Petar [Laboratory for Anthropology, Institute of Anatomy, School of Medicine, University of Belgrade, Dr. Subotica 4/2, 11000 Belgrade (Serbia); Kisic, Danilo [Laboratory for Atomic Physics, Institute of Nuclear Sciences “Vinca”, University of Belgrade, Belgrade (Serbia); Zelic, Ksenija; Djuric, Marija [Laboratory for Anthropology, Institute of Anatomy, School of Medicine, University of Belgrade, Dr. Subotica 4/2, 11000 Belgrade (Serbia); Rakocevic, Zlatko, E-mail: zlatkora@vinca.rs [Laboratory for Atomic Physics, Institute of Nuclear Sciences “Vinca”, University of Belgrade, Belgrade (Serbia)

    2014-08-30

    Graphical abstract: - Highlights: • Surface free energy and surface roughness influence bacterial adhesion. • Bacterial colonization causes periimplantitis and implant loss. • Zinc-based, glass-ionomers and resin-cements were investigated. • Glass-ionomers-cements present the lowest values of surface free energy and roughness. • Glass-ionomer-cements surface properties result with reduced bacterial adhesion. - Abstract: Background: Material surface free energy and surface roughness strongly influence the bacterial adhesion in oral cavity. The aim of this study was to analyze these two parameters in various commercial luting agents used for cementation of implant restorations. Materials and methods: Zinc-based, glass-ionomers, resin modified glass-ionomer and resin-cements were investigated. Contact angle and surface free energy were measured by contact angle analyzer using Image J software program. Materials’ average roughness and fractal dimension were calculated based on Atomic Force Microscope topography images. Results: Zinc phosphate cements presented significantly higher total surface free energy and significantly lower dispersive component of surface free energy compared to other groups, while resin-cements showed significantly lower polar component than other groups. The surface roughness and fractal dimension values were statistically the highest in the zinc phosphate cements and the lowest for the glass-ionomers cements. Conclusion: Glass-ionomers-cements presented lower values of surface free energy and surface roughness than zinc phosphate and resin cements, indicating that their surfaces are less prone to biofilm adhesion. Practical implications: Within limitations of an in vitro trial, our results indicate that glass-ionomers-cements could be the cements of choice for fixation of cement retained implant restorations due to superior surface properties compared to zinc phosphate and resin cements, which may result in reduced plaque formation

  13. Surface characterization of the cement for retention of implant supported dental prostheses: In vitro evaluation of cement roughness and surface free energy

    International Nuclear Information System (INIS)

    Brajkovic, Denis; Antonijevic, Djordje; Milovanovic, Petar; Kisic, Danilo; Zelic, Ksenija; Djuric, Marija; Rakocevic, Zlatko

    2014-01-01

    Graphical abstract: - Highlights: • Surface free energy and surface roughness influence bacterial adhesion. • Bacterial colonization causes periimplantitis and implant loss. • Zinc-based, glass-ionomers and resin-cements were investigated. • Glass-ionomers-cements present the lowest values of surface free energy and roughness. • Glass-ionomer-cements surface properties result with reduced bacterial adhesion. - Abstract: Background: Material surface free energy and surface roughness strongly influence the bacterial adhesion in oral cavity. The aim of this study was to analyze these two parameters in various commercial luting agents used for cementation of implant restorations. Materials and methods: Zinc-based, glass-ionomers, resin modified glass-ionomer and resin-cements were investigated. Contact angle and surface free energy were measured by contact angle analyzer using Image J software program. Materials’ average roughness and fractal dimension were calculated based on Atomic Force Microscope topography images. Results: Zinc phosphate cements presented significantly higher total surface free energy and significantly lower dispersive component of surface free energy compared to other groups, while resin-cements showed significantly lower polar component than other groups. The surface roughness and fractal dimension values were statistically the highest in the zinc phosphate cements and the lowest for the glass-ionomers cements. Conclusion: Glass-ionomers-cements presented lower values of surface free energy and surface roughness than zinc phosphate and resin cements, indicating that their surfaces are less prone to biofilm adhesion. Practical implications: Within limitations of an in vitro trial, our results indicate that glass-ionomers-cements could be the cements of choice for fixation of cement retained implant restorations due to superior surface properties compared to zinc phosphate and resin cements, which may result in reduced plaque formation

  14. Controllable synthesis of Ln3+ (Ln = Tb, Eu) doped zinc phosphate nano-/micro-structured materials: phase, morphology and luminescence properties

    Science.gov (United States)

    Yue, Dan; Lu, Wei; Li, Chunyang; Zhang, Xinlei; Liu, Chunxia; Wang, Zhenling

    2014-01-01

    Ln3+ (Ln = Tb, Eu) doped zinc phosphate tetrahydrate (ZPT:Ln3+) and ammonium zinc phosphate (AZP:Ln3+) nano-/micro-structured materials were synthesized in aqueous solution without the addition of any structure-directing agent. The phase structures, morphologies and luminescence properties of the as-synthesized samples were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), photoluminescence (PL) spectroscopy and lifetime. These investigations indicate that different phosphate sources MnH(3-n)PO4 (M = NH4+ or Na+, n = 1, 2, 3) can lead to the altering of morphology from nanosheet to microflower, but have no significant effect on the phase structure of the samples. The microlump, nanosheet, and microflower (constructed by the primary microlumps or nanosheets) of orthorhombic ZPT:Ln3+ could be selectively prepared by adjusting the pH value from 3.5 to 7.0. A mixture of orthorhombic ZPT:Ln3+ and monoclinic AZP:Ln3+ with a microflower morphology was obtained when the pH value was adjusted to 8.0. Monoclinic AZP:Ln3+ microplate, microcube and nanoparticle morphologies were obtained at pH values of 8.5, 9.0 and 11.0 respectively. The phase transformation and growth mechanism of the diverse morphologies were proposed, and ZPT:Ln3+ (Ln3+ = Eu or Tb) samples exhibit red or green emission under the excitation of UV light.Ln3+ (Ln = Tb, Eu) doped zinc phosphate tetrahydrate (ZPT:Ln3+) and ammonium zinc phosphate (AZP:Ln3+) nano-/micro-structured materials were synthesized in aqueous solution without the addition of any structure-directing agent. The phase structures, morphologies and luminescence properties of the as-synthesized samples were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), photoluminescence (PL) spectroscopy and lifetime. These

  15. Nanoparticles of zinc sulfide doped with manganese, nickel and copper as nanophotocatalyst in the degradation of organic dyes

    International Nuclear Information System (INIS)

    Pouretedal, Hamid Reza; Norozi, Abbas; Keshavarz, Mohammad Hossein; Semnani, Abolfazl

    2009-01-01

    Nanoparticles of zinc sulfide as undoped and doped with manganese, nickel and copper were used as photocatalyst in the photodegradation of methylene blue and safranin as color pollutants. Photoreactivity of doped zinc sulfide was varied with dopant, mole fraction of dopant to zinc ion, pH of solution, dosage of photocatalyst and concentration of dye. The characterization of nanoparticles was studied using X-ray powder diffraction (XRD) patterns and UV-vis spectra. The maximum degradation efficiency was obtained in the presence of Zn 0.98 Mn 0.02 S, Zn 0.94 Ni 0.06 S and Zn 0.90 Cu 0.10 S as nanophotocatalyst. The effect of dosage of photocatalyst was studied in the range of 20-250 mg/L. It was seen that 150.0 mg/L of photocatacyst is an optimum value for the dosage of photocatalyst. The most degradation efficiency was obtained in alkaline pH of 11.0 with study of photodegradation in pH amplitude of 2-12. The degradation efficiency was decreased in dye concentrations above of 5.0 mg/L for methylene blue and safranin dyes. In the best conditions, the degradation efficiency was obtained 87.3-95.6 and 85.4-93.2 for methylene blue and safranin, respectively

  16. Hydrogen permeation resistant phosphate coatings

    International Nuclear Information System (INIS)

    McGuire, J.C.

    1979-01-01

    A method for reducing hydrogen diffusion through metal wherein the metal is coated with a phosphate-radical-containing, phosphate-glass-forming material on at least one surface thereof. The coating is then heated to at least 350 0 C to form a phosphate glass. This method is especially applicable to nuclear reactors to minimize tritium diffusion. The coating is preferably formed with a solution of phosphoric acid which may also contain compounds such as MnSO 4 , SiO 2 and Na 2 Cr 2 0 7 . (author)

  17. Hydrogen permeation resistant phosphate coatings

    International Nuclear Information System (INIS)

    McGuire, J.C.

    1979-01-01

    A method for reducing hydrogen diffusion through metal is described. The metal is coated with a phosphate-radical-containing, phosphate-glass-forming material on at least one surface. The coating is then heated to at least 350 0 C to form a phosphate glass. This method is especially applicable to nuclear reactors to minimize tritium diffusion. The coating is preferably formed with a solution of phosphoric acid which may also contain compounds such as MnSO 4 , SiO 2 and Na 2 Cr 2 O 7 . (author)

  18. Sodium aluminum-iron phosphate glass-ceramics for immobilization of lanthanide oxide wastes from pyrochemical reprocessing of spent nuclear fuel

    Science.gov (United States)

    Stefanovsky, S. V.; Stefanovsky, O. I.; Kadyko, M. I.; Nikonov, B. S.

    2018-03-01

    Sodium aluminum (iron) phosphate glass ceramics containing of up to 20 wt.% rare earth (RE) oxides simulating pyroprocessing waste were produced by melting at 1250 °C followed by either quenching or slow cooling to room temperature. The iron-free glass-ceramics were composed of major glass and minor phosphotridymite and monazite. The iron-bearing glass-ceramics were composed of major glass and minor monazite and Na-Al-Fe orthophosphate at low waste loadings (5-10 wt.%) and major orthophosphate and minor monazite as well as interstitial glass at high waste loadings (15-20 wt.%). Slowly cooled samples contained higher amount of crystalline phases than quenched ones. Monazite is major phase for REs. Leach rates from the materials of major elements (Na, Al, Fe, P) are 10-5-10-7 g cm-2 d-1, RE elements - lower than 10-5 g cm-2 d-1.

  19. Flame retardancy mechanisms of bisphenol A bis(diphenyl phosphate) in combination with zinc borate in bisphenol A polycarbonate/acrylonitrile-butadiene-styrene blends

    International Nuclear Information System (INIS)

    Pawlowski, Kristin H.; Schartel, Bernhard; Fichera, Mario A.; Jaeger, Christian

    2010-01-01

    Bisphenol A polycarbonate/acrylonitrile-butadiene-styrene (PC/ABS) with and without bisphenol A bis(diphenyl phosphate) (BDP) and 5 wt.% zinc borate (Znb) were investigated. The pyrolysis was studied by thermogravimetry (TG), TG-FTIR and NMR, the fire behaviour with a cone calorimeter applying different heat fluxes, LOI and UL 94. Fire residues were examined with NMR. BDP affects the decomposition of PC/ABS and acts as a flame retardant in the gas and condensed phases. The addition of Znb results in an additional hydrolysis of PC. The fire behaviour is similar to PC/ABS, aside from a slightly increased LOI and a reduced peak heat release rate, both caused by borates improving the barrier properties of the char. In PC/ABS + BDP + Znb, the addition of Znb yields a borate network and amorphous phosphates. Znb also reacts with BDP to form alpha-zinc phosphate and borophosphates that suppress the original flame retardancy mechanisms of BDP. The inorganic-organic residue formed provides more effective flame retardancy, in particular at low irradiation in the cone calorimeter, and a clear synergy in LOI, whereas for more developed fires BDP + Znb become less effective than BDP in PC/ABS with respect to the total heat evolved.

  20. On the reflectivity of nickel neutron mirrors

    Energy Technology Data Exchange (ETDEWEB)

    Adib, M.; Maayouf, R.M.A.; Abdel-Kawy, A.; Habib, N. (Atomic Energy Establishment, Cairo (Egypt). Reactor and Neutron Physics Dept.); Kenawy, M.A.; Wahba, M.; Ashry, A.H. (Ain Shams Univ., Cairo (Egypt))

    1991-02-01

    Neutron reflectivities were determined for 300 nm thick films of natural nickel and nickel 58 coated on glass plates. The measurements were performed at glancing angles between 40' and 60'. The incident neutron beam from one of the ET-RR-1 reactor horizontal channels covered neutron wavelengths between 0.55 and 0.80 nm. It was found that nickel 58, because of the high value of its critical glancing angle, is more efficient as a neutron mirror than natural nickel. (orig.).

  1. Influence of silver nanoparticles on the spectroscopic properties of Sm3+ doped boro-phosphate glasses

    Science.gov (United States)

    Suthanthirakumar, P.; Marimuthu, K.

    2016-05-01

    The Sm3+ doped novel boro-phosphate glasses containing silver nanoparticles (NPs) (SmBPxA) have been prepared following the melt quenching technique and their structural and spectroscopic behavior were studied through HR-TEM, optical absorption and photoluminescence spectral measurements. The TEM analysis validates the existence of Ag NPs with an average diameter of ~8 nm. The Surface plasmon resonance (SPR) band of silver NPs was found at around 600 nm from the absorption spectrum of the Sm3+ ions free glass sample. The optical band gap energy (Eopt) corresponding to the direct and indirect allowed transitions and the Urbach energy (ΔE) values were determined from the absorption spectral measurements. The luminescence intensity is found to get enhance when the Ag NPs were embedded along with the Sm3+ ions in the prepared glasses due to the local electric field effect around the rare earth (RE) ion site produced by the SPR of Ag NPs.

  2. Gamma rays shielding and sensing application of some rare earth doped lead-alumino-phosphate glasses

    Science.gov (United States)

    Kaur, Preet; Singh, Devinder; Singh, Tejbir

    2018-03-01

    Seven rare earth (Sm3+, Eu3+ and Nd3+) doped lead alumino phosphate glasses were prepared. The protective and sensing measures from gamma rays were analysed in terms of parameters viz. density (ρ), refractive index, energy band gap (Eg), mean free path (mfp), effective atomic number (Zeff) and buildup factors (energy absorption EABF as well as exposure buildup factor EBF). The energy dependent parameters (mfp, Zeff, EABF and EBF) were investigated in the energy region from 15 keV to 15 MeV. EABF and EBF values were observed to be maximum in the intermediate energy region. Besides, the EABF and EBF values for the prepared samples are shown to have strong dependence on chemical composition of the glass at lower energy, whereas, it is almost independent of chemical composition in higher energy region. The prepared glass samples are found to have potential applications in radiation shielding as well as radiation sensing, which further find numerous applications in the field of medicine and industry.

  3. Thermo-physical and structural studies of sodium zinc borovanadate glasses in the region of high concentration of modifier oxides

    Energy Technology Data Exchange (ETDEWEB)

    Chethana, B.K. [Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560 012 (India); Reddy, C. Narayana [Maharani' s Science College for Women, Bangalore 560 001 (India); Rao, K.J., E-mail: kalyajrao@yahoo.co.in [Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560 012 (India)

    2012-07-15

    Highlights: ► Highly modified sodium zinc borovanadate glasses. ► Structural model for borovanadate glasses. ► Network forming tendency of ZnO in borovanadate glasses. ► Fragility can be limited to NBO concentration in borovanadate glasses. -- Abstract: This paper reports investigation of Na{sub 2}O and ZnO modified borovanadate glasses in the highly modified regime of compositions. These glasses have been prepared by microwave route. Ultraviolet (UV) and visible, infrared (IR), Magic Angle Spinning Nuclear Magnetic Resonance (MAS NMR) and Electron Paramagnetic Resonance (EPR) spectroscopies have been used to characterize the speciation in the glasses. Together with the variation of properties such as molar volume and glass transition temperatures, spectroscopic data indicate that at high levels of modification, ZnO tends to behave like network former. It is proposed that the observed variation of all the properties can be reasonably well understood with a structural model. The model considers that the modification and speciation in glasses are strongly determined by the hierarchy of group electronegativities. Further, it is proposed that the width of the transitions of glasses obtained under same condition reflects the fragility of the glasses. An empirical expression has been suggested to quantify fragility on the basis of width of the transition regions.

  4. Structural and luminescence studies on Dy3+ doped lead boro-telluro-phosphate glasses

    Science.gov (United States)

    Selvi, S.; Venkataiah, G.; Arunkumar, S.; Muralidharan, G.; Marimuthu, K.

    2014-12-01

    This paper reports results obtained on the structural and luminescence properties of Dy3+doped lead boro-telluro-phosphate glasses prepared following the melt quenching technique. FTIR spectra exhibit the presence of B-O vibrations, P-O-P symmetric vibrations and Te-O stretching modes of TeO3 and TeO6 units. The metal-ligand bond was identified through UV-vis-NIR absorption spectra and to determine the band tailing parameter, direct and indirect band gap energy of the prepared glasses. The Judd-Ofelt (JO) intensity parameters (Ω2, Ω4 and Ω6), experimental and theoretical oscillator strengths were also determined and reported. Luminescence measurements were made to determine the transition probability (A), stimulated emission cross-section (σPE) and branching ratio (βR) for the transitions that include 4F9/2→6H11/2, 6H13/2 and 6H15/2 bands. The effect of Dy3+ ion concentration on the intensity ratio of yellow to blue emission bands has also been studied and reported. The lifetime corresponding to the 4F9/2 level of the title glasses has been found to decrease with the increase in Dy3+ ion concentration. The chromaticity coordinates (x,y) have been estimated from the luminescence spectra and the suitability of title glasses for white light applications has been analyzed using CIE chromaticity diagram. The variation of optical properties with the concentration of dysprosium oxide content in the glasses have been studied and reported.

  5. Single-step fabrication of stressed waveguides with tubular depressed-cladding in phosphate glasses using ultrafast vortex laser beams

    Directory of Open Access Journals (Sweden)

    Cheng Guanghua

    2013-11-01

    Full Text Available We report on the fabrication of the stressed optical waveguide with tubular depressed-refractive-index cladding in phosphate glasses by use of femtosecond vortex beam. Strained regions were emerged in domains surrounding the tubular track. Waveguiding occurs mainly within the tube induced by femtosecond laser.

  6. Synthesis and Tribological Performance of Different Particle-Sized Nickel-Ion-Exchanged α-Zirconium Phosphates

    Science.gov (United States)

    Zhang, Xiaosheng; Xu, Hong; Dong, Jinxiang

    2018-03-01

    Nickel-ion-exchanged α-zirconium phosphate (Ni-α-ZrP) was synthesized by a mild hydrothermal synthesis method. Different raw material ratios (NaF/H3PO4/Ni(CH3COO)2·4H2O) influence the particle size of the Ni-α-ZrP samples. The grain size could be controlled and distributed from 20 to 600 nm. Ni-α-ZrP was evaluated as an additive in lithium grease in a four-ball test. A 3.0 wt.% addition of Ni-α-ZrP to lithium grease yielded maximum non-seizure load values of 1235 N, and the wear scar diameter on the lower balls is 0.42 mm at 294 N. Compared with smaller particles, the addition of Ni-α-ZrP with a larger particle size to grease yields a better load-carrying capacity.

  7. Structure and properties of ZnO-B{sub 2}O{sub 3}-P{sub 2}O{sub 5}-TeO{sub 2} glasses

    Energy Technology Data Exchange (ETDEWEB)

    Mosner, Petr, E-mail: petr.mosner@upce.cz [Department of General and Inorganic Chemistry, University of Pardubice, Faculty of Chemical Technology, 53210 Pardubice (Czech Republic); Vosejpkova, Katerina; Koudelka, Ladislav [Department of General and Inorganic Chemistry, University of Pardubice, Faculty of Chemical Technology, 53210 Pardubice (Czech Republic); Montagne, Lionel; Revel, Bertrand [Unite de Catalyse et de Chimie du Solide - UCCS, Univ Lille Nord de France, F-59000, CNRS UMR 8181, USTL F-59655, ENSCL F-59652, Villeneuve d' Ascq (France)

    2010-11-01

    Zinc borophosphate glasses doped with TeO{sub 2} were studied in the compositional series (100 - x)[0.5ZnO-0.1B{sub 2}O{sub 3}-0.4P{sub 2}O{sub 5}]-xTeO{sub 2} in a broad concentration range of x = 0-80 mol% TeO{sub 2}. The structure of the glasses was studied by Raman and IR spectroscopy and by {sup 31}P and {sup 11}B MAS NMR spectroscopy. According to the Raman and IR spectra, TeO{sub 2} is incorporated in the structural network in the form of TeO{sub 3}, TeO{sub 3+1} and TeO{sub 4} structural units. The ratio of TeO{sub 4}/TeO{sub 3} increases with increasing TeO{sub 2} content in the glasses. The incorporation of TeO{sub x} units into the glass network is associated with the depolymerisation of phosphate chains, as revealed by Raman spectroscopy. The incorporation of TeO{sub 2} modifies also the coordination of boron atoms, where B(OP){sub 4} structural units are gradually replaced by B(OP){sub 4-n}(OTe){sub n} units. The addition of TeO{sub 2} to the parent zinc borophosphate glass results in a decrease of glass transition temperature associated with the replacement of stronger P-O and B-O bonds by weaker Te-O bonds. Chemical durability of glasses reveals a minimum at the glass containing 10 mol% TeO{sub 2}, but with further additions of TeO{sub 2} it improves and the glasses with a high TeO{sub 2} content reveal better durability than the parent zinc borophosphate glass.

  8. Structural characterization of the nickel thin film deposited by glad technique

    Directory of Open Access Journals (Sweden)

    Potočnik J.

    2013-01-01

    Full Text Available In this work, a columnar structure of nickel thin film has been obtained using an advanced deposition technique known as Glancing Angle Deposition. Nickel thin film was deposited on glass sample at the constant emission current of 100 mA. Glass sample was positioned 15 degrees with respect to the nickel vapor flux. The obtained nickel thin film was characterized by Force Modulation Atomic Force Microscopy and by Scanning Electron Microscopy. Analysis indicated that the formation of the columnar structure occurred at the film thickness of 1 μm, which was achieved for the deposition time of 3 hours. [Projekat Ministarstva nauke Republike Srbije, br. III45005

  9. Metal complex derivatives of hydrogen uranyl phosphate

    International Nuclear Information System (INIS)

    Grohol, D.; Blinn, E.L.

    1994-01-01

    Derivatives of hydrogen uranyl phosphate were prepared by incorporating transition metal complexes into the uranyl phosphate matrix. The transition metal complexes employed include bis(ethylenediamine)copper(II), bis(1,3-propanediamine)copper(II) chloride, (triethylenetetramine)copper(II), (1,4,8,11-tetraazacyclotetradecane)copper(II), (1,4,8,12-tetraazacyclopentadecane)copper(II), (1,4,8,11-tetraazacyclotetradecane)nickel(II) chloride, (triethylenetetramine)nickel(II) and others. The chemical analyses of these derivatives indicated that the incorporation of the transition metal complexes into the uranyl phosphate matrix via ion exchange was not stoichiometric. The extent of ion exchange is dependent on the size and structure of the transition metal complex. All complexes were characterized by X-ray powder diffractometry, electronic and infrared spectra, thermal analyses and chemical analysis. An attempt was made to correlate the degree of quenching of the luminescence of the uranyl ion to the spacing between the uranyl phosphate layers in the derivatives

  10. Bone Regeneration of Rat Tibial Defect by Zinc-Tricalcium Phosphate (Zn-TCP Synthesized from Porous Foraminifera Carbonate Macrospheres

    Directory of Open Access Journals (Sweden)

    Joshua Chou

    2013-12-01

    Full Text Available Foraminifera carbonate exoskeleton was hydrothermally converted to biocompatible and biodegradable zinc-tricalcium phosphate (Zn-TCP as an alternative biomimetic material for bone fracture repair. Zn-TCP samples implanted in a rat tibial defect model for eight weeks were compared with unfilled defect and beta-tricalcium phosphate showing accelerated bone regeneration compared with the control groups, with statistically significant bone mineral density and bone mineral content growth. CT images of the defect showed restoration of cancellous bone in Zn-TCP and only minimal growth in control group. Histological slices reveal bone in-growth within the pores and porous chamber of the material detailing good bone-material integration with the presence of blood vessels. These results exhibit the future potential of biomimetic Zn-TCP as bone grafts for bone fracture repair.

  11. Sorption of phosphate and zinc onto hematite and magnetite as mechanism of attenuation of contamination in agricultural soils

    OpenAIRE

    Martínez Martínez, María del Rosario; Martí, Vicens; Giménez Izquierdo, Francisco Javier

    2014-01-01

    Excess of natural and synthetic fertilizers applied to agricultural soils is a well-known source of contamination of nitrates and potential source of contamination of metals (copper and zinc) and phosphates (Alloway 2010). Mineral phases such as iron oxides, are present in agricultural soils and they might play a main role in the retardation of the transport of different contaminants (Giménez et al. 2007). The present communication shows the experimental study of sorption of phosp...

  12. Near-UV sensitized 1.06 μm emission of Nd{sup 3+} ions via monovalent copper in phosphate glass

    Energy Technology Data Exchange (ETDEWEB)

    Jiménez, José A., E-mail: jose.jimenez@unf.edu [Department of Chemistry, University of North Florida, Jacksonville, FL 32224 (United States); Sendova, Mariana [Optical Spectroscopy & Nano-Materials Lab, New College of Florida, Sarasota, FL 34243 (United States)

    2015-07-15

    Monovalent copper ions effectively incorporated in Nd-containing phosphate glass by a single-step melt-quench method have been established as near-ultraviolet (UV) sensitizers of Nd{sup 3+} ions, resulting in a remarkable {sup 4}F{sub 3/2} → {sup 4}I{sub 11/2} emission at 1.06 μm. The spectroscopic data indicates an efficient energy conversion process. The Cu{sup +} ions first absorb photons broadly around 360 nm, and subsequently transfer the energy from the Stokes-shifted emitting states to resonant Nd{sup 3+} energy levels in the visible. Ultimately, the Nd{sup 3+} electronic excited states decay and the upper lasing state {sup 4}F{sub 3/2} is populated, leading to the enhanced emission at 1.06 μm. The characteristic features of the Cu{sup +} visible emission spectra and the reduced lifetime of the corresponding Cu{sup +} donor states indicate an efficient non-radiative transfer. The Cu{sup +}/Nd{sup 3+} co-doped phosphate glass appears suitable as solid-state laser material with enhanced pump range in the near-UV part of the spectrum and for solar spectral conversion in photovoltaic cells. - Graphical abstract: Display Omitted - Highlights: • Monovalent copper ions effectively stabilized in Nd{sup 3+}-containing phosphate glass. • Enhanced Nd{sup 3+} near-infrared emission observed upon the Cu{sup +} ions incorporation. • Cu{sup +} → Nd{sup 3+} non-radiative energy transfer efficiencies and likely energy transfer pathways evaluated. • Potential for solid-state lasers and solar spectral conversion suggested.

  13. Chemically durable iron phosphate glasses for vitrifying sodium bearing waste (SBW) using conventional and cold crucible induction melting (CCIM) techniques

    Energy Technology Data Exchange (ETDEWEB)

    Kim, C.W. E-mail: cheol@umr.edu; Ray, C.S.; Zhu, D.; Day, D.E.; Gombert, D.; Aloy, A.; Mogus-Milankovic, A.; Karabulut, M

    2003-11-01

    A simulated sodium bearing waste (SBW) was successfully vitrified in iron phosphate glasses (IPG) at a maximum waste loading of 40 wt% using conventional and cold crucible induction melting (CCIM) techniques. No sulfate segregation or crystalline phases were detectable in the IPG when examined by SEM and XRD. The IPG wasteforms containing 40 wt% SBW satisfy current DOE requirements for aqueous chemical durability as evaluated from their bulk dissolution rate (D{sub R}), product consistency test, and vapor hydration test. The fluid IPG wasteforms can be melted at a relatively low temperature (1000 deg. C) and for short times (<6 h). These properties combined with a significantly higher waste loading, and the feasibility of CCIM melting offer considerable savings in time, energy, and cost for vitrifying the SBW stored at the Idaho National Engineering and Environmental Laboratory in iron phosphate glasses.

  14. Synthesis and different optical properties of Gd2O3 doped sodium zinc tellurite glasses

    Science.gov (United States)

    Samanta, Buddhadev; Dutta, Dibakar; Ghosh, Subhankar

    2017-06-01

    A series of Gd2O3 doped sodium zinc tellurite [xGd2O3-(0.8-x) TeO2-0.1Na2O-0.1ZnO] glasses are prepared by the conventional melt quenching method and their optical properties have been studied. UV-vis spectrophotometric studies within the wavelength range from 230 nm-800 nm are carried out in the integrating sphere mode to study the effect of Gd2O3 doping on the optical band gap (Eg), refractive index (n), dielectric constant (εr) and susceptibility (χ). Other physical properties like molar volume, molar refraction, polarizability, metallization criterion, number density of rare-earth ions (N), polaron radius (rp), inter ionic distance (ri), molar cation polarizability (∑αi), number of oxide ions in chemical composition (NO2-), optical band gap based electronic oxide ion polarizability (αO2-) and optical basicity (Λ) of glass samples have been studied on the basis of UV-vis spectra and density profile of the different glasses.

  15. Optical spectroscopy and luminescence properties of Ho3+ doped zinc fluorophosphate (ZFP) glasses for green luminescent device applications

    Science.gov (United States)

    Reddy Prasad, V.; Damodaraiah, S.; Ratnakaram, Y. C.

    2018-04-01

    Ho3+ doped zinc fluorophosphate (ZFP) glasses with molar chemical compositions, (60-x) NH4H2PO4+20ZnO+10BaF2+10NaF+xHo2O3 (where x = 0.1, 0.3, 0.5, 1.0 and 1.5 mol%) were prepared by melt quenching technique. These glasses were characterized through physical, structural, optical, excitation, luminescence and decay curve analysis. From the absorption spectra, spectral intensities (fexp and fcal), Judd-Ofelt intensity parameters (Ω2, Ω4 and Ω6), radiative transition probabilities (AT), radiative lifetimes (τR) and branching ratios (βR) were evaluated for all Ho3+ doped ZFP glass matrices. From the photoluminescence spectra, peak stimulated emission cross-sections (σP) were calculated for all Ho3+ doped ZFP glasses. The Ho3+ doped ZFP glasses show strong green emission at 545 nm and red emission at 656 nm under excitation, 450 nm. The measured lifetimes (τmeas) of (5S2)5F4 level of Ho3+ doped ZFP glasses were obtained from decay profiles. The CIE color coordinates of Ho3+ doped ZFP glasses were calculated from emission spectra and 1.0 mol% of Ho3+ doped ZFP glass matrix gives green emission. Hence, these results confirm that the Ho3+ doped ZFP glasses could be considered as a promising candidate for visible green laser applications.

  16. Crystal growth in zinc borosilicate glasses

    Science.gov (United States)

    Kullberg, Ana T. G.; Lopes, Andreia A. S.; Veiga, João P. B.; Monteiro, Regina C. C.

    2017-01-01

    Glass samples with a molar composition (64+x)ZnO-(16-x)B2O3-20SiO2, where x=0 or 1, were successfully synthesized using a melt-quenching technique. Based on differential thermal analysis data, the produced glass samples were submitted to controlled heat-treatments at selected temperatures (610, 615 and 620 °C) during various times ranging from 8 to 30 h. The crystallization of willemite (Zn2SiO4) within the glass matrix was confirmed by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM). Under specific heat-treatment conditions, transparent nanocomposite glass-ceramics were obtained, as confirmed by UV-vis spectroscopy. The influence of temperature, holding time and glass composition on crystal growth was investigated. The mean crystallite size was determined by image analysis on SEM micrographs. The results indicated an increase on the crystallite size and density with time and temperature. The change of crystallite size with time for the heat-treatments at 615 and 620 °C depended on the glass composition. Under fixed heat-treatment conditions, the crystallite density was comparatively higher for the glass composition with higher ZnO content.

  17. Spectroscopic study of biologically active glasses

    Science.gov (United States)

    Szumera, M.; Wacławska, I.; Mozgawa, W.; Sitarz, M.

    2005-06-01

    It is known that the chemical activity phenomenon is characteristic for some inorganic glasses and they are able to participate in biological processes of living organisms (plants, animals and human bodies). An example here is the selective removal of silicate-phosphate glass components under the influence of biological solutions, which has been applied in designing glasses acting as ecological fertilizers of controlled release rate of the nutrients for plants. The structure of model silicate-phosphate glasses containing the different amounts of the glass network formers, i.e. Ca 2+ and Mg 2+, as a binding components were studied. These elements besides other are indispensable of the normal growth of plants. In order to establish the function and position occupied by the particular components in the glass structure, the glasses were examined by FTIR spectroscopy (with spectra decomposition) and XRD methods. It has been found that the increasing amount of MgO in the structure of silicate-phosphate glasses causes the formation of domains the structure of which changes systematically from a structure of the cristobalite type to a structure corresponding to forsterite type. Whilst the increasing content of CaO in the structure of silicate-phosphate glasses causes the formation of domains the structure of which changes from a structure typical for cristobalite through one similar to the structure of calcium orthophosphate, to a structure corresponding to calcium silicates. The changing character of domains structure is the reason of different chemical activity of glasses.

  18. Research, development and demonstration of nickel-zinc batteries for electric vehicle propulsion. Annual report, 1979

    Energy Technology Data Exchange (ETDEWEB)

    1980-06-01

    Progress achieved under ANL Contract No. 31-109-38-4248 from 16 August 1978 to 16 August 1979 is reported. The first segment of the overall program, component development, consists of four basic tasks proceeding in parallel: nickel electrode development, zinc electrode development, separator development, and sealed cell development. Each of these tasks is reported herein on a self-contained basis. System engineering is the second major subdivision of the effort. It includes the design and testing of all cells, the investigation of charge control devices and techniques, and the complete analysis of all cells for failure modes. It also encompasses the accelerated testing of 20-Ah cells. To date, large numbers of these cells (incorporating separator variations, active material additives and internal design variations) have been subjected to this type of testing. 48 figures, 47 tables. (RWR)

  19. Silver aggregates and twofold-coordinated tin centers in phosphate glass: A photoluminescence study

    International Nuclear Information System (INIS)

    Jimenez, J.A.; Lysenko, S.; Liu, H.; Fachini, E.; Resto, O.; Cabrera, C.R.

    2009-01-01

    The optical properties of silver species in various oxidation and aggregation states and of tin centers in melt-quenched phosphate glasses have been assessed by optical absorption and photoluminescence (PL) spectroscopy. Glasses containing silver and tin, or either dopant, were studied. Emission and excitation spectra along with time-resolved and temperature-dependent PL measurements were employed in elucidating the different emitting centers observed and investigating on their interactions. In regard to silver, the data suggests the presence of luminescent single Ag + ions, Ag + -Ag + and Ag + -Ag 0 pairs, and nonluminescent Ag nanoparticles (NPs), where Ag + -Ag 0 →Ag + -Ag + energy transfer is indicated. Tin optical centers appear as twofold-coordinated Sn centers displaying PL around 400 nm ascribed to triplet-to-singlet electronic transitions. The optically active silver centers were observed in glasses where 8 mol% of both Ag 2 O and SnO, and 4 mol% of Ag 2 O were added. Heat treatment (HT) of the glass with the high concentration of silver and tin leads to chemical reduction of ionic silver species resulting in a large volume fraction of silver NPs and the vanishing of silver PL features. Further characterization of such heat-treated glass by transmission electron microscopy and X-ray photoelectron spectroscopy appears consistent with silver being present mainly in nonoxidized form after HT. On the other hand, HT of the glass containing only silver results in the quenching of Ag + -Ag 0 pairs emission that is ascribed to nonradiative energy transfer to Ag NPs due to the positioning of the pairs near the surface of NPs during HT. In this context, an important finding is that a faster relaxation was observed for this nanocomposite in relation to a heat-treated glass containing both silver and tin (no silver pairs) as revealed by degenerate four-wave mixing spectroscopy. Such result is attributed to Ag NP→Ag + -Ag 0 plasmon resonance energy transfer. The

  20. Zinc, nickel and cadmium in carambolas marketed in Guangzhou and Hong Kong, China: Implication for human health

    International Nuclear Information System (INIS)

    Li, J.T.; Liao, B.; Lan, C.Y.; Qiu, J.W.; Shu, W.S.

    2007-01-01

    Carambola (Averrhoa carambola L.) is a popular juicy fruit throughout the tropical and subtropical world. This study was designed to quantify the levels of zinc (Zn), nickel (Ni) and cadmium (Cd) in carambolas marketed in southern China, and further to evaluate the potential health risk of human consumption of carambola. Zinc concentrations, ranging from 1.471 to 2.875 mg/kg (on fresh weight basis), were below the maximum permissible concentration for Zn in fruit of China (5 mg/kg). However, Ni concentrations (0.134-0.676 mg/kg) were considerably higher than the related recommendation values. Furthermore, Cd concentrations in 51% of the carambolas purchased from Guangzhou exceeded the maximum permissible concentration for Cd in fruit of China (0.03 mg/kg). Our results implicated that the consumption of 0.385 kg carambola contaminated by Cd per day would cause the tolerable daily intake (TDI) of Cd by the consumer to be exceeded. In addition, the remarkably high Ni concentrations in carambolas should also be of concern. The status of heavy metal contamination of carambola products marketed in the other regions and their implications for human health should be identified urgently by in-depth studies

  1. Zinc, nickel and cadmium in carambolas marketed in Guangzhou and Hong Kong, China: Implication for human health

    Energy Technology Data Exchange (ETDEWEB)

    Li, J.T.; Liao, B.; Lan, C.Y. [School of Life Sciences and State Key Laboratory of Biocontrol, Sun Yat-sen (Zhongshan) University, Guangzhou 510275, Guangdong (China); Qiu, J.W. [Deparment of Biology, Hong Kong Baptist University, Kowloon, Hong Kong (China); Shu, W.S. [School of Life Sciences and State Key Laboratory of Biocontrol, Sun Yat-sen (Zhongshan) University, Guangzhou 510275, Guangdong (China)], E-mail: shuws@mail.sysu.edu.cn

    2007-12-15

    Carambola (Averrhoa carambola L.) is a popular juicy fruit throughout the tropical and subtropical world. This study was designed to quantify the levels of zinc (Zn), nickel (Ni) and cadmium (Cd) in carambolas marketed in southern China, and further to evaluate the potential health risk of human consumption of carambola. Zinc concentrations, ranging from 1.471 to 2.875 mg/kg (on fresh weight basis), were below the maximum permissible concentration for Zn in fruit of China (5 mg/kg). However, Ni concentrations (0.134-0.676 mg/kg) were considerably higher than the related recommendation values. Furthermore, Cd concentrations in 51% of the carambolas purchased from Guangzhou exceeded the maximum permissible concentration for Cd in fruit of China (0.03 mg/kg). Our results implicated that the consumption of 0.385 kg carambola contaminated by Cd per day would cause the tolerable daily intake (TDI) of Cd by the consumer to be exceeded. In addition, the remarkably high Ni concentrations in carambolas should also be of concern. The status of heavy metal contamination of carambola products marketed in the other regions and their implications for human health should be identified urgently by in-depth studies.

  2. Zinc, nickel and cadmium in carambolas marketed in Guangzhou and Hong Kong, China: implication for human health.

    Science.gov (United States)

    Li, J T; Liao, B; Lan, C Y; Qiu, J W; Shu, W S

    2007-12-15

    Carambola (Averrhoa carambola L.) is a popular juicy fruit throughout the tropical and subtropical world. This study was designed to quantify the levels of zinc (Zn), nickel (Ni) and cadmium (Cd) in carambolas marketed in southern China, and further to evaluate the potential health risk of human consumption of carambola. Zinc concentrations, ranging from 1.471 to 2.875 mg/kg (on fresh weight basis), were below the maximum permissible concentration for Zn in fruit of China (5 mg/kg). However, Ni concentrations (0.134-0.676 mg/kg) were considerably higher than the related recommendation values. Furthermore, Cd concentrations in 51% of the carambolas purchased from Guangzhou exceeded the maximum permissible concentration for Cd in fruit of China (0.03 mg/kg). Our results implicated that the consumption of 0.385 kg carambola contaminated by Cd per day would cause the tolerable daily intake (TDI) of Cd by the consumer to be exceeded. In addition, the remarkably high Ni concentrations in carambolas should also be of concern. The status of heavy metal contamination of carambola products marketed in the other regions and their implications for human health should be identified urgently by in-depth studies.

  3. Effect of molybdenum on the severity of toxicity symptoms in flax induced by an excess of either manganese, zinc, copper, nickel or cobalt in the nutrient solution

    Energy Technology Data Exchange (ETDEWEB)

    Millikan, C R

    1947-01-01

    The addition of molybdenum to solutions containing an excess of either manganese, zinc, copper, nickel or cobalt respectively, resulted in decreases in the severity of iron deficiency symptoms which normally occurred when flax was grown in solutions containing the same concentrations of any of these elements, but without molybdenum. The efficacy of molybdenum in this regard increased with increasing concentration up to 25 parts per million. However, concentrations of 0.5 to 2 parts per million of molybdenum had little effect on the severity of iron deficiency symptoms at the concentrations of heavy metals used. Molybdenum 5, 10 or 25 parts per million also retarded the date of appearance and reduced the severity of lower leaf necrosis which is another characteristic symptom of the presence of excess manganese (25 to 100 parts per million) in the nutrient solution. It is concluded that an essential function of molybdenum is intimately associated with the regulation of the deleterious effect of manganese, zinc, copper, nickel or cobalt on the physiological availability of iron to the plant. 46 references, 3 figures.

  4. Excitation light source dependence of emission in Sn2+-Ce3+ codoped ZnO-P2O5 glasses

    OpenAIRE

    Masai, Hirokazu; Hino, Yusuke; Yanagida, Takayuki; Fujimoto, Yutaka; Fukuda, Kentaro; Yoko, Toshinobu

    2013-01-01

    Correlation between excitation light source and the emission property of Sn^{2+}-Ce^{3+} co-doped zinc phosphate glasses is examined. Although photoluminescence (PL) peaks of both Sn^{2+}and Ce^{3+} shifted with increasing amount of Ce^{3+}, there was little energy resonance between Sn^{2+} and Ce^{3+} emission centers. On the other hand, radioluminescence (RL) spectra excited by X-ray was independent of the Ce concentration, indicating that emission was mainly observed from Sn^{2+} emission ...

  5. Glasses Containing Iron (II, III) Oxides For Immobilization Of Radioactive Technetium

    International Nuclear Information System (INIS)

    Kruger, A.A.; Heo, J.; Xu, K.; Choi, J.K.; Hrma, P.R.; Um, W.

    2011-01-01

    Technetium-99 (Tc-99) has posed serious environmental threats as US Department of Energy's high-level waste. This work reports the vitrification of Re, as surrogate for Tc-99, by iron-borosilicate and iron-phosphate glasses, respectively. Iron-phosphate glasses can dissolve Re as high as ∼ 1.2 wt. %, which can become candidate waste forms for Tc-99 disposal, while borosilicate glasses can retain less than 0.1 wt. % of Re due to high melting temperature and long melting duration. Vitrification of Re as Tc-99's mimic was investigated using iron-borosilicate and iron-phosphate glasses. The retention of Re in borosilicate glasses was less than 0.1 wt. % and more than 99 wt. % of Re were volatilized due to high melting temperature and long melting duration. Because the retention of Re in iron-phosphate glasses is as high as 1.2 wt. % and the volatilization is reduced down to ∼50 wt. %, iron-phosphate glasses can be one of the glass waste form candidates for Tc (or Re) disposal. The investigations of chemical durability and leaching test of iron-phosphate glasses containing Re are now underway to test the performance of the waste form.

  6. Heat accumulation regime of femtosecond laser writing in fused silica and Nd:phosphate glass

    Energy Technology Data Exchange (ETDEWEB)

    Bukharin, M.A. [Moscow Institute of Physics and Technology, Moscow Region (Russian Federation); Optosystems Ltd., Troitsk, Moscow (Russian Federation); Khudyakov, D.V. [Optosystems Ltd., Troitsk, Moscow (Russian Federation); Physics Instrumentation Center of the General Physics Institute, Troitsk, Moscow (Russian Federation); Vartapetov, S.K. [Physics Instrumentation Center of the General Physics Institute, Troitsk, Moscow (Russian Federation)

    2015-04-01

    We investigated refractive index induced by direct femtosecond laser writing inside fused silica and Nd:phosphate glass in heat accumulation regime. Spatial profile and magnitude of induced refractive index were investigated at various pulse repetition rates and translation velocities. It was shown that the magnitude of induced refractive index significantly rises with decreasing in time interval between successive laser pulses below the time for thermal diffusion. Going from nonthermal regime to heat accumulation regime, we achieved induced refractive index growth from 4 x 10{sup -3} up to 6.5 x 10{sup -3} in fused silica and from -6 x 10{sup -3} to -9 x 10{sup -3} in Nd:phosphate glass. Aspect ratio of treated area decreased from 2.1 down to less than 1.5 without correcting optical elements. It was shown that in heat accumulation regime, the treated area was surrounded by region of alternatively changed refractive index with significant magnitude up to -2 x 10{sup -3}. Wide regions of decreased refractive index enable fabrication of depressed cladding waveguides. We demonstrated low-loss (0.3 dB/cm) tubular waveguide inside fused silica. For orthogonal polarizations of guiding light, we achieved a small difference between losses as 0.1 dB/cm using highly symmetric written tracks forming the cladding. The desired structure was simulated with the beam propagation method, and the results were in good agreement with experiment data. (orig.)

  7. Removal of phosphate from water by amine-functionalized copper ferrite chelated with La(III).

    Science.gov (United States)

    Gu, Wei; Li, Xiaodi; Xing, Mingchao; Fang, Wenkan; Wu, Deyi

    2018-04-01

    Eutrophication has become a worldwide environmental problem and removing phosphorus from water/wastewater before discharge is essential. The purpose of our present study was to develop an efficient material in terms of both phosphate adsorption capacity and magnetic separability. To this end, we first compared the performances of four spinel ferrites, including magnesium, zinc, nickel and copper ferrites. Then we developed a copper ferrite-based novel magnetic adsorbent, by synthesizing 1,6-hexamethylenediamine-functionalized copper ferrite(CuFe 2 O 4 ) via a single solvothermal synthesis process followed by LaCl 3 treatment. The materials were characterized with X-ray diffraction, transmission electron microscope, vibrating sample magnetometer, Fourier transform infrared spectra and N 2 adsorption-desorption. The maximum adsorption capacity of our material, calculated from the Langmuir adsorption isotherm model, attained 32.59mg/g with a saturation magnetization of 31.32emu/g. Data of adsorption kinetics were fitted well to the psuedo-second-order model. Effects of solution pH and coexisting anions (Cl - , NO 3 - , SO 4 2- ) on phosphate adsorption were also investigated, showing that our material had good selectivity for phosphate. But OH - competed efficiently with phosphate for adsorption sites. Furthermore, increasing both NaOH concentration and temperature resulted in an enhancement of desorption efficiency. Thus NaOH solution could be used to desorb phosphate adsorbed on the material for reuse, by adopting a high NaOH concentration and/or a high temperature. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Alkali-free bioactive glasses for bone regeneration =

    Science.gov (United States)

    Kapoor, Saurabh

    Bioactive glasses and glass-ceramics are a class of third generation biomaterials which elicit a special response on their surface when in contact with biological fluids, leading to strong bonding to living tissues. The purpose of the present study was to develop diopside based alkali-free bioactive glasses in order to achieve good sintering behaviour, high bioactivity, and a dissolution/ degradation rates compatible with the target applications in bone regeneration and tissue engineering. Another aim was to understand the structure-property relationships in the investigated bioactive glasses. In this quest, various glass compositions within the Diopside (CaMgSi2O6) - Fluorapatite (Ca5(PO4)3F) - Tricalcium phosphate (3CaO•P2O5) system have been investigated. All the glasses were prepared by melt-quenching technique and characterized by a wide array of complementary characterization techniques. The glass-ceramics were produced by sintering of glass powders compacts followed by a suitable heat treatment to promote the nucleation and crystallization phenomena. Furthermore, selected parent glass compositions were doped with several functional ions and an attempt to understand their effects on the glass structure, sintering ability and on the in vitro bio-degradation and biomineralization behaviours of the glasses was made. The effects of the same variables on the devitrification (nucleation and crystallization) behaviour of glasses to form bioactive glass-ceramics were also investigated. Some of the glasses exhibited high bio-mineralization rates, expressed by the formation of a surface hydroxyapatite layer within 1-12 h of immersion in a simulated body fluid (SBF) solution. All the glasses showed relatively lower degradation rates in comparison to that of 45S5 Bioglass. Some of the glasses showed very good in vitro behaviour and the glasses co-doped with zinc and strontium showed an in vitro dose dependent behaviour. The as-designed bioactive glasses and glass

  9. Site-selective electroless nickel plating on patterned thin films of macromolecular metal complexes.

    Science.gov (United States)

    Kimura, Mutsumi; Yamagiwa, Hiroki; Asakawa, Daisuke; Noguchi, Makoto; Kurashina, Tadashi; Fukawa, Tadashi; Shirai, Hirofusa

    2010-12-01

    We demonstrate a simple route to depositing nickel layer patterns using photocross-linked polymer thin films containing palladium catalysts, which can be used as adhesive interlayers for fabrication of nickel patterns on glass and plastic substrates. Electroless nickel patterns can be obtained in three steps: (i) the pattern formation of partially quaterized poly(vinyl pyridine) by UV irradiation, (ii) the formation of macromolecular metal complex with palladium, and (iii) the nickel metallization using electroless plating bath. Metallization is site-selective and allows for a high resolution. And the resulting nickel layered structure shows good adhesion with glass and plastic substrates. The direct patterning of metallic layers onto insulating substrates indicates a great potential for fabricating micro/nano devices.

  10. Study of the surface crystallization and resistance to dissolution of niobium phosphate glasses for nuclear waste immobilization

    International Nuclear Information System (INIS)

    Vieira, Heveline

    2008-01-01

    The surface crystallization and the dissolution rate of three phosphate glass compositions containing different amounts of niobium oxide were studied. The glasses were named Nb30, Nb37, and Nb44 according to the nominal content of niobium oxide in the glass composition. The three compositions were evaluated keeping the P 2 O 5 /K 2 O ratio constant and varying the amount of Nb 2 O 5 . These glasses were produced by melting appropriate chemical compounds at 1500 deg C for 0.5 hour. The crystalline phases which were nucleated on the glass surface after heat treatment were determined by X-ray diffraction. The crystalline structures depend on the amount of niobium oxide in the glass composition. The crystal morphologies were observed by using an optical microscope, and their characteristics are specific for each kind of crystalline phase. The crystal growth rate and the surface nuclei density were determined for each glass composition, and they depend on each crystalline phase nucleated on the surface. From the differential thermal analysis curves it was determined that the Nb44 glass containing 46.5 mol por cent of niobium oxide is the most thermally stable against crystallization when compared to the Nb30 and Nb37 glasses. According to the activation energies determined for crystal growth on the surface of each glass type, the Nb44 glass can also be considered the most resistant one against crystallization. The dissolution rate for the Nb44 glass after 14 days immersed in an aqueous solution with pH equals to 7 at 90 deg C is the lowest (9.0 x 10 -7 g. cm -2 . day -1 ) when compared to the other two glass compositions. The dissolution rates in acidic and neutral solutions of all studied glasses meet the international standards for materials which can be used in the immobilization of nuclear wastes. (author)

  11. Influence of silver nanoparticles on the spectroscopic properties of Sm{sup 3+} doped boro-phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Suthanthirakumar, P.; Marimuthu, K., E-mail: emari-ram2000@yahoo.com [Department of Physics, Gandhigram Rural University, Gandhigram - 624 302 (India)

    2016-05-23

    The Sm{sup 3+} doped novel boro-phosphate glasses containing silver nanoparticles (NPs) (SmBPxA) have been prepared following the melt quenching technique and their structural and spectroscopic behavior were studied through HR-TEM, optical absorption and photoluminescence spectral measurements. The TEM analysis validates the existence of Ag NPs with an average diameter of ~8 nm. The Surface plasmon resonance (SPR) band of silver NPs was found at around 600 nm from the absorption spectrum of the Sm{sup 3+} ions free glass sample. The optical band gap energy (E{sub opt}) corresponding to the direct and indirect allowed transitions and the Urbach energy (ΔE) values were determined from the absorption spectral measurements. The luminescence intensity is found to get enhance when the Ag NPs were embedded along with the Sm{sup 3+} ions in the prepared glasses due to the local electric field effect around the rare earth (RE) ion site produced by the SPR of Ag NPs.

  12. Research, development and demonstration of nickel-zinc batteries for electric vehicle propulsion. Annual report, 1979. [70 W/lb

    Energy Technology Data Exchange (ETDEWEB)

    1980-06-01

    This second annual report under Contract No. 31-109-39-4200 covers the period July 1, 1978 through August 31, 1979. The program demonstrates the feasibility of the nickel-zinc battery for electric vehicle propulsion. The program is divided into seven distinct but highly interactive tasks collectively aimed at the development and commercialization of nickel-zinc technology. These basic technical tasks are separator development, electrode development, product design and analysis, cell/module battery testing, process development, pilot manufacturing, and thermal management. A Quality Assurance Program has also been established. Significant progress has been made in the understanding of separator failure mechanisms, and a generic category of materials has been specified for the 300+ deep discharge (100% DOD) applications. Shape change has been reduced significantly. A methodology has been generated with the resulting hierarchy: cycle life cost, volumetric energy density, peak power at 80% DOD, gravimetric energy density, and sustained power. Generation I design full-sized 400-Ah cells have yielded in excess of 70 W/lb at 80% DOD. Extensive testing of cells, modules, and batteries is done in a minicomputer-based testing facility. The best life attained with electric vehicle-size cell components is 315 cycles at 100% DOD (1.0V cutoff voltage), while four-cell (approx. 6V) module performance has been limited to about 145 deep discharge cycles. The scale-up of processes for production of components and cells has progressed to facilitate component production rates of thousands per month. Progress in the area of thermal management has been significant, with the development of a model that accurately represents heat generation and rejection rates during battery operation. For the balance of the program, cycle life of > 500 has to be demonstrated in modules and full-sized batteries. 40 figures, 19 tables. (RWR)

  13. Luminescence properties of Dy3+ doped lithium zinc borosilicate glasses for photonic applications

    Directory of Open Access Journals (Sweden)

    N. Jaidass

    2018-03-01

    Full Text Available Different concentrations of Dy3+ ions doped lithium zinc borosilicate glasses of chemical composition (30-x B2O3 - 25 SiO2 -10 Al2O3 -30 LiF - 5 ZnO - x Dy2O3 (x = 0, 0.1, 0.5, 1.0 and 2.0 mol% were prepared by the melt quenching technique. The prepared glasses were investigated through X-ray diffraction, optical absorption, photoluminescence and decay measurements. Intensities of absorption bands expressed in terms of oscillator strengths (f were used to determine the Judd-Ofelt (J-O intensity parameters Ωλ (λ = 2, 4 and 6. The evaluated J-O parameters were used to determine the radiative parameters such as transition probabilities (AR, total transition probability rate (AT, radiative lifetime (τR and branching ratios (βR for the excited 4F9/2 level of Dy3+ ions. The chromaticity coordinates determined from the emission spectra were found to be located in the white light region of CIE chromaticity diagram. Keywords: Condensed matter physics, Engineering, Materials science

  14. Phosphate recycling in the phosphorus industry

    NARCIS (Netherlands)

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

    2001-01-01

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

  15. Glass microspheres for medical applications

    Science.gov (United States)

    Conzone, Samuel David

    Radioactive dysprosium lithium borate glass microspheres have been developed as biodegradable radiation delivery vehicles for the radiation synovectomy treatment of rheumatoid arthritis. Once injected into a diseased joint, the microspheres deliver a potent dose of radiation to the diseased tissue, while a non-uniform chemical reaction converts the glass into an amorphous, porous, hydrated dysprosium phosphate reaction product. The non-radioactive, lithium-borate component is dissolved from the glass (up to 94% weight loss), while the radioactive 165Dy reacts with phosphate anions in the body fluids, and becomes "chemically" trapped in a solid, dysprosium phosphate reaction product that has the same size as the un-reacted glass microsphere. Ethylene diamine tetraacetate (EDTA) chelation therapy can be used to dissolve the dysprosium phosphate reaction product after the radiation delivery has subsided. The dysprosium phosphate reaction product, which formed in vivo in the joint of a Sprague-Dawley rat, was dissolved by EDTA chelation therapy in 100 Gy) of localized beta radiation to a treatment site within the body, followed by complete biodegradability. The non-uniform reaction process is a desirable characteristic for a biodegradable radiation delivery vehicle, but it is also a novel material synthesis technique that can convert a glass to a highly porous materials with widely varying chemical composition by simple, low-temperature, glass/solution reaction. The reaction product formed by nonuniform reaction occupies the same volume as the un-reacted glass, and after drying for 1 h at 300°C, has a specific surface area of ≈200 m2/g, a pore size of ≈30 nm, and a nominal crushing strength of ≈10 MPa. Finally, rhenium glass microspheres, composed of micron-sized, metallic rhenium particles dispersed within a magnesium alumino borate glass matrix were produced by sintering ReO2 powder and glass frit at 1050°C. A 50 mg injection of radioactive rhenium glass

  16. Nickel removal from nickel plating waste water using a biologically active moving-bed sand filter.

    Science.gov (United States)

    Pümpel, Thomas; Macaskie, Lynne E; Finlay, John A; Diels, Ludo; Tsezos, Marios

    2003-12-01

    Efficient removal of dissolved nickel was observed in a biologically active moving-bed 'MERESAFIN' sand filter treating rinsing water from an electroless nickel plating plant. Although nickel is fully soluble in this waste water, its passage through the sand filter promoted rapid removal of approximately 1 mg Ni/l. The speciation of Ni in the waste water was modelled; the most probable precipitates forming under the conditions in the filter were predicted using PHREEQC. Analyses of the Ni-containing biosludge using chemical, electron microscopical and X-ray spectroscopic techniques confirmed crystallisation of nickel phosphate as arupite (Ni3(PO4)2 x 8H2O), together with hydroxyapatite within the bacterial biofilm on the filter sand grains. Biosorption contributed less than 1% of the overall sequestered nickel. Metabolising bacteria are essential for the process; the definitive role of specific components of the mixed population is undefined but the increase in pH promoted by metabolic activity of some microbial components is likely to promote nickel desolubilisation by others.

  17. Homocoupling of benzyl halides catalyzed by POCOP-nickel pincer complexes

    KAUST Repository

    Chen, Tao

    2012-08-01

    Two types of POCOP-nickel(II) pincer complexes were prepared by mixing POCOP pincer ligands and NiX 2 in toluene at reflux. The resulting nickel complexes efficiently catalyze the homocoupling reactions of benzyl halides in the presence of zinc. The coupled products were obtained in excellent to quantitative yields. © 2012 Elsevier Ltd. All rights reserved.

  18. Lid heater for glass melter

    International Nuclear Information System (INIS)

    Phillips, T.D.

    1993-01-01

    A glass melter having a lid electrode for heating the glass melt radiantly. The electrode comprises a series of INCONEL 690 tubes running above the melt across the melter interior and through the melter walls and having nickel cores inside the tubes beginning where the tubes leave the melter interior and nickel connectors to connect the tubes electrically in series. An applied voltage causes the tubes to generate heat of electrical resistance for melting frit injected onto the melt. The cores limit heat generated as the current passes through the walls of the melter. Nickel bus connection to the electrical power supply minimizes heat transfer away from the melter that would occur if standard copper or water-cooled copper connections were used between the supply and the INCONEL 690 heating tubes. 3 figures

  19. Manganese activated phosphate glass for dosimetry

    International Nuclear Information System (INIS)

    Regulla, D.

    1975-01-01

    A measuring element comprises a metaphosphate glass doped with manganese as an activator. The manganese activated metaphosphate glass can detect and determine radiation doses in the range between milliroentgens and more than 10 megaroentgens. (auth)

  20. Red light generation through the lead boro-telluro-phosphate glasses activated by Eu3+ ions

    Science.gov (United States)

    Selvi, S.; Marimuthu, K.; Suriya Murthy, N.; Muralidharan, G.

    2016-09-01

    Lead boro-telluro-phosphate glasses containing 0.05 to 2.0 wt% of Eu3+ ions were prepared through melt quenching technique. Structural characteristics of title glasses were identified through XRD, FTIR and Raman studies. The optical properties of the prepared glasses were studied using UV-Vis-NIR absorption and photoluminescence spectra. From the resultant spectra, we have obtained the bonding parameters (δ), nephelauxetic ratio (β), direct and indirect band gaps and Urbach energy (ΔE) values. A deep red luminescence due to 5D0 → 7F2 transition of Eu3+ ions could be observed for the title glasses. The local site symmetry around the Eu3+ ions and the degree of Eu3+-O2- covalence were assessed from the luminescence intensity ratio of 5D0 → 7F2/5D0 → 7F1 transitions. Judd-Ofelt intensity parameters, calculated from the luminescence spectra, were used to estimate the radiative parameters like transition probability (A), branching ratio (βexp, βcal) and stimulated emission cross-section (σPE) concerning the 5D0 → 7FJ (J = 0, 1, 2, 3 and 4) transitions. The important laser parameters, gain bandwidth and optical gain are also estimated. The decay curves associated with the transition from 5D0 state was found to be single-exponential at all Eu3+ ion concentrations. CIE colour coordinates and colour purity of the prepared glasses were estimated from the CIE chromaticity diagram.

  1. Chromium, Nickel and Zinc Levels from Canned and Non-Canned ...

    African Journals Online (AJOL)

    DR. AMINU

    2013-06-01

    Jun 1, 2013 ... Water soluble nickel salts do not readily enter cell. Therefore, these compounds are generally not carcinogenic in animals and, to a large extent, have not been considered potent human carcinogens, although recent studies have suggested an increase in cancer in nickel refinery areas where exposure to ...

  2. Accelerated bone ingrowth by local delivery of Zinc from bioactive ...

    African Journals Online (AJOL)

    2015-10-19

    Oct 19, 2015 ... Aims: This study aims to evaluate in vivo the performance therapy of zinc-doped bioactive glass (BG-Zn) and ... Keywords: zinc metallic ion; bioactive glass; osteoporosis; trabecular bone architecture; mechanical property; oxidative stress ..... Ducheyne P, Qiu Q. Bioactive ceramics: the effect of surface.

  3. The structure of phosphate and borosilicate glasses and their structural evolution at high temperatures as studied with solid state NMR spectroscopy: Phase separation, crystallisation and dynamic species exchange

    International Nuclear Information System (INIS)

    Wegner, S.; Van Wullen, L.; Tricot, G.; Tricot, G.

    2010-01-01

    In this contribution we present an in-depth study of the network structure of different phosphate based and borosilicate glasses and its evolution at high temperatures. Employing a range of advanced solid state NMR methodologies, complemented by the results of XPS, the structural motifs on short and intermediate length scales are identified. For the phosphate based glasses, at temperatures above the glass transition temperature Tg, structural relaxation processes and the devitrification of the glasses were monitored in situ employing MAS NMR spectroscopy and X-ray diffraction. Dynamic species exchange involving rapid P-O-P and P-O-Al bond breaking and reforming was observed employing in situ 27 Al and 31 P MAS NMR spectroscopy and could be linked to viscous flow. For the borosilicate glasses, an atomic scale investigation of the phase separation processes was possible in a combined effort of ex situ NMR studies on glass samples with different thermal histories and in situ NMR studies using high temperature MAS NMR spectroscopy including 11 B MAS, 29 Si MAS and in situ 29 Si{ 11 B} REAPDOR NMR spectroscopy. (authors)

  4. Development and evaluation of holmium doped phosphate glass microspheres for selective internal radiotherapy

    International Nuclear Information System (INIS)

    Barros Filho, Eraldo C.; Martinelli, Jose Roberto; Squair, Peterson L; Osso Junior, Joao A.; Sene, Frank Ferrer

    2013-01-01

    Selective Internal Radiotherapy is used to treat hepatocellular carcinoma. In this treatment 90 Y -doped aluminosilicate glass microspheres are introduced in the hepatic artery and they migrate to the liver near to the tumor where they are trapped in the arterioles. The radiation β- emitted by the decay of 90 Y annihilates the cancer cells. A macroaggregate of albumin containing technetium is previously used to monitor the lung shunt and to prevent the spreading of 90 Y during the treatment. In the present work, 165 Ho- doped phosphate glass microspheres were developed aiming that application. 165 Ho has high cross section for neutron capture (64 bars) and 166 Ho decays emitting β- radiation with appropriate energy for killing cancer cells, and gamma rays with low energy which can be used to obtain images of the microspheres location and to check possible occurrence of lung shunt. Holmium also is highly paramagnetic and can be used to obtain images whereby NMR. The glass matrix consists of (P 2 O 5 ) tetrahedrons and can be produced by a relatively lower melting temperature of chemical compounds. The 31 P decays by emitting β- radiation and contributes to the absorbed dose, helping to annihilate the cancer cells. The microspheres were produced by using two methods: the flame and the gravitation falling methods to obtain microspheres with appropriate properties. (author)

  5. Non-thiolate ligation of nickel by nucleotide-free UreG of Klebsiella aerogenes

    Energy Technology Data Exchange (ETDEWEB)

    Martin-Diaconescu, Vlad; Joseph, Crisjoe A.; Boer, Jodi L.; Mulrooney, Scott B.; Hausinger, Robert P.; Maroney, Michael J.

    2016-12-21

    Nickel-dependent ureases are activated by a multiprotein complex that includes the GTPase UreG. Prior studies showed that nucleotide-free UreG from Klebsiella aerogenes is monomeric and binds one nickel or zinc ion with near-equivalent affinity using an undefined binding site, whereas nucleotide-free UreG from Helicobacter pylori selectively binds one zinc ion per dimer via a universally conserved Cys-Pro-His motif in each protomer. Iodoacetamide-treated K. aerogenes UreG was nearly unaffected in nickel binding compared to non-treated sample, suggesting the absence of thiolate ligands to the metal. X-ray absorption spectroscopy of nickel-bound UreG showed the metal possessed four-coordinate geometry with all O/N donor ligands including one imidazole, thus confirming the absence of thiolate ligation. The nickel site in Strep-tag II-modified protein possessed six-coordinate geometry, again with all O/N donor ligands, but now including two or three imidazoles. An identical site was noted for the Strep-tag II-modified H74A variant, substituted in the Cys-Pro-His motif, ruling out coordination by this His residue. These results are consistent with metal binding to both His6 and a His residue of the fusion peptide in Strep-tagged K. aerogenes UreG. We conclude that the nickel- and zinc-binding site in nucleotide-free K. aerogenes UreG is distinct from that of nucleotide-free H. pylori UreG and does not involve the Cys-Pro-His motif. Further, we show the Strep-tag II can perturb metal coordination of this protein.

  6. Diffusion of alloying elements in liquid nickel

    International Nuclear Information System (INIS)

    Ershov, G.S.; Majboroda, V.P.; Permyakova, T.V.

    1990-01-01

    Values of diffusion coefficients for chromium, vanadium, zinc, silicon, tin, antimony, lead and zirconium in liquid nickel are determined within 1500-1700 deg C temperature range using annular gap technique. The data obtained are explained concerning microheterogeneous structure of metallic melts

  7. Structural and luminescence studies on Dy{sup 3+} doped lead boro–telluro-phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Selvi, S. [Department of Physics, Gandhigram Rural University, Gandhigram 624302 (India); Venkataiah, G. [Department of Physics, Sri Venkateswara University, Tirupati 517502 (India); Arunkumar, S.; Muralidharan, G. [Department of Physics, Gandhigram Rural University, Gandhigram 624302 (India); Marimuthu, K., E-mail: mari_ram2000@yahoo.com [Department of Physics, Gandhigram Rural University, Gandhigram 624302 (India)

    2014-12-01

    This paper reports results obtained on the structural and luminescence properties of Dy{sup 3+}doped lead boro−telluro-phosphate glasses prepared following the melt quenching technique. FTIR spectra exhibit the presence of B−O vibrations, P−O−P symmetric vibrations and Te−O stretching modes of TeO{sub 3} and TeO{sub 6} units. The metal–ligand bond was identified through UV−vis−NIR absorption spectra and to determine the band tailing parameter, direct and indirect band gap energy of the prepared glasses. The Judd−Ofelt (JO) intensity parameters (Ω{sub 2}, Ω{sub 4} and Ω{sub 6}), experimental and theoretical oscillator strengths were also determined and reported. Luminescence measurements were made to determine the transition probability (A), stimulated emission cross-section (σ{sub P}{sup E}) and branching ratio (β{sub R}) for the transitions that include {sup 4}F{sub 9/2}→{sup 6}H{sub 11/2}, {sup 6}H{sub 13/2} and {sup 6}H{sub 15/2} bands. The effect of Dy{sup 3+} ion concentration on the intensity ratio of yellow to blue emission bands has also been studied and reported. The lifetime corresponding to the {sup 4}F{sub 9/2} level of the title glasses has been found to decrease with the increase in Dy{sup 3+} ion concentration. The chromaticity coordinates (x,y) have been estimated from the luminescence spectra and the suitability of title glasses for white light applications has been analyzed using CIE chromaticity diagram. The variation of optical properties with the concentration of dysprosium oxide content in the glasses have been studied and reported.

  8. Stressed waveguides with tubular depressed-cladding inscribed in phosphate glasses by femtosecond hollow laser beams.

    Science.gov (United States)

    Long, Xuewen; Bai, Jing; Zhao, Wei; Stoian, Razvan; Hui, Rongqing; Cheng, Guanghua

    2012-08-01

    We report on the single-step fabrication of stressed optical waveguides with tubular depressed-refractive-index cladding in phosphate glasses by the use of focused femtosecond hollow laser beams. Tubelike low index regions appear under direct exposure due to material rarefaction following expansion. Strained compacted zones emerged in domains neighboring the tubular track of lower refractive index, and waveguiding occurs mainly within the tube core fabricated by the engineered femtosecond laser beam. The refractive index profile of the optical waveguide was reconstructed from the measured transmitted near-field intensity.

  9. Imbalance of morphofunctional responses of Jurkat T lymphoblasts at short-term culturing with relief zinc- or copper-containing calcium phosphate coating on titanium.

    Science.gov (United States)

    Litvinova, L S; Shupletsova, V V; Dunets, N A; Khaziakhmatova, O G; Yurova, K A; Khlusova, M Yu; Slepchenko, G B; Cherempey, E G; Sharkeev, Yu P; Komarova, E G; Sedelnikova, M B; Khlusov, I A

    2017-01-01

    Morphofunctional response of Jurkat T cells that were cultured for 24 h on substrates prepared from commercially pure titanium with relief microarc bilateral calcium phosphate coating containing copper or zinc was studied. Changes in the concentration of essential trace elements contained in this coating can cause significant imbalance of molecular processes of differentiation, secretion, apoptosis, and necrosis and reduce tumor cell survival.

  10. Characterization of aqueous interactions of copper-doped phosphate-based glasses by vapour sorption.

    Science.gov (United States)

    Stähli, Christoph; Shah Mohammadi, Maziar; Waters, Kristian E; Nazhat, Showan N

    2014-07-01

    Owing to their adjustable dissolution properties, phosphate-based glasses (PGs) are promising materials for the controlled release of bioinorganics, such as copper ions. This study describes a vapour sorption method that allowed for the investigation of the kinetics and mechanisms of aqueous interactions of PGs of the formulation 50P2O5-30CaO-(20-x)Na2O-xCuO (x=0, 1, 5 and 10mol.%). Initial characterization was performed using (31)P magic angle spinning nuclear magnetic resonance and attenuated total reflectance-Fourier transform infrared spectroscopy. Increasing CuO content resulted in chemical shifts of the predominant Q(2) NMR peak and of the (POP)as and (PO(-)) Fourier transform infrared absorptions, owing to the higher strength of the POCu bond compared to PONa. Vapour sorption and desorption were gravimetrically measured in PG powders exposed to variable relative humidity (RH). Sorption was negligible below 70% RH and increased exponentially with RH from 70 to 90%, where it exhibited a negative correlation with CuO content. Vapour sorption in 0% and 1% CuO glasses resulted in phosphate chain hydration and hydrolysis, as evidenced by protonated Q(0)(1H) and Q(1)(1H) species. Dissolution rates in deionized water showed a linear correlation (R(2)>0.99) with vapour sorption. Furthermore, cation release rates could be predicted based on dissolution rates and PG composition. The release of orthophosphate and short polyphosphate species corroborates the action of hydrolysis and was correlated with pH changes. In conclusion, the agreement between vapour sorption and routine characterization techniques in water demonstrates the potential of this method for the study of PG aqueous reactions. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  11. Phosphate-bonded composite electrodes for hydrogen evolution

    Energy Technology Data Exchange (ETDEWEB)

    Potvin, E.; Menard, H.; Lalancette, J.M. (Sherbrooke Univ., PQ (Canada). Dept. de Chimie); Brossard, L. (Institut de Recherche d' Hydro-Quebec, Varennes, PQ (Canada))

    1990-03-01

    A new process of cementing metallic powders to produce high surface area cathodes for alkaline water electrolysis is described. The binding compound is a tridimensional polymer of aluminium phosphate (AlPO{sub 4}). Phosphate-bonded composite electrodes give a low-polarization performance for hydrogen evolution in 1 M KOH aqueous solution in the case of 95wt% Pt and 98wt%Ni. When electrode materials are prepared with nickel powder, the electrocatalytic activity for the hydrogen evolution reaction, the chemical stability and the electrical conductivity depend on the Ni content and morphology of the electrode. The best performance and chemical stability with Ni as the starting material are obtained for spiky filamentary particles produced by the decomposition of nickel carbonyl. (author).

  12. Soft solution synthesis and intense visible photoluminescence of lamellar zinc oxide hybrids

    International Nuclear Information System (INIS)

    Sağlam, Özge

    2013-01-01

    Graphical abstract: -- In this study, we demonstrate the synthesis of layered zinc oxide films intercalated with dodecyl sulphate ions by a simple soft solution process. The presence of potassium (K + ) and lithium (Li + ) ions in the precursor solution of layered zinc hydroxide resulted in lamellar hybrid zinc oxide films instead of layered zinc hydroxides. On the other hand, the addition of nickel phthalocyanine induces zinc hydroxide host layers which exhibit an intense blue emission. This is also promoted by K + and Li + ions

  13. The Impact of Hydrocalumites Additives on the Electrochemical Performance of Zinc-Nickel Secondary Cells

    International Nuclear Information System (INIS)

    Wen, Xing; Yang, Zhanhong; Xiao, Xiang; Yang, Huan; Xie, Xiaoe; Huang, Jianhang

    2016-01-01

    Hydrocalumites additives are synthesized and proposed as an anodic additive for Zinc/Nickel alkaline secondary batteries. The as-prepared additives are characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). And the results illustrate that hydrocalumites additives are successfully prepared and have the typical structure of layered double hydroxides (LDHs). The effects of hydrocalumites additives on electrochemical performances of ZnO have been investigated by cyclic voltammetry (CV), tafel polarization tests, electrochemical impedance spectroscopy (EIS) and galvanostatic charge and discharge. Compared to the electrode with pure ZnO, the electrodes containing hydrocalumites additives show better reversibility, reveal better anti-corrosion property and exhibit more stable cycle performance. Especially when the electrode added with 12% (wt.) hydrocalumites, it exhibits the best cycle performance than the other electrodes. And its discharge capacity is about 450 mAh g −1 all the time, and hardly declines over all the 400 cycles. Based on these observations, the prepared hydrocalumites may be a promising and efficient additive for the ZnO electrode.

  14. Photoluminescence properties of Er{sup 3+}-doped alkaline earth titanium phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Murthy, D.V.R.; Babu, A. Mohan [Department of Physics, Sri Venkateswara University, Tirupati 517 502 (India); Jamalaiah, B.C. [Department of Physics, Sree Vidyanikethan Engineering College, Tirupati, 517 102 (India); Moorthy, L. Rama, E-mail: lrmphysics@yahoo.co.i [Department of Physics, Sri Venkateswara University, Tirupati 517 502 (India); Jayasimhadri, M.; Jang, Kiwan; Lee, Ho Sueb [Department of Physics, Changwon National University, Changwon 641-773 (Korea, Republic of); Yi, Soung Soo [Department of Photonics, Silla University, Pusan 617-736 (Korea, Republic of); Jeong, Jung Hyun [Department of Physics, Pukyong National University, Pusan 608-737 (Korea, Republic of)

    2010-02-18

    Er{sup 3+}-doped alkaline earth titanium phosphate (RTP) glasses with molar composition of 24 (NaPO{sub 3}){sub 6} + 30 KH{sub 2}PO{sub 4} + 25 TiO{sub 2} + 20 RCl{sub 2} + 1 Er{sub 2}O{sub 3} were prepared by melt quenching technique. Judd-Ofelt intensity parameters ({Omega}{sub 2,4,6}) were determined from the experimental oscillator strengths (f{sub exp}) of absorption bands. From these parameters spontaneous emission probabilities (A{sub R}), luminescence branching ratios ({beta}{sub R}) and radiative lifetimes ({tau}{sub R}) have been calculated. Visible and near infrared photoluminescence spectra has been recorded by exciting the samples at 380 and 970 nm respectively. An intense broad emission band at 1.53 {mu}m was observed corresponding to {sup 4}I{sub 13/2} {yields} {sup 4}I{sub 15/2} transition. McCumber theory has been applied to determine the emission cross-sections ({sigma}{sub e}) of the {sup 4}I{sub 13/2} {yields} {sup 4}I{sub 15/2} transition using the absorption cross-sections ({sigma}{sub a}). The lifetimes of {sup 4}S{sub 3/2} level were measured for the glasses by exciting the samples at 540 nm wavelength and the quantum efficiencies were also determined.

  15. ynthesis, theoretical study on Zinc (II and Ni(II complexes of 5-methoxyisatin 3-[N-(4-chlorophenyl thiosemicarbazone

    Directory of Open Access Journals (Sweden)

    Fatma Kandemirli

    2012-03-01

    Full Text Available Zinc(II and nickel(II-complexes of 5-methoxyisatin 3-[N-(4-chlorophenyl thiosemicarbazone] (H2MICP were synthesized and characterized by infrared, ultraviolet and 1H-NMR spectroscopies as well as elemental analysis. Model of H2MICP and its zinc(II and nickel(II-complexes were optimized with B3LYP method using 6-31G(d,p, 6-311G(d,p, 6-311++G(d,p, 6-311++G(2d,2p basis sets. The calculated 1H-NMR, UV and IR spectra data were compared with experimental results. In addition to the Natural Bond Orbital (NBO analysis of H2MICP and its Zinc(II and Nickel(II complexes, Fukui functions of H2MICP were also reported.

  16. Electrical and optical properties of zinc oxide: thin films

    International Nuclear Information System (INIS)

    Zuhairusnizam Md Darus; Abdul Jalil Yeop Majlis; Anis Faridah Md Nor; Burhanuddin Kamaluddin

    1992-01-01

    Zinc oxide films have been prepared by high temperature oxidation of thermally evaporated zinc films on glass substrates. The resulting films are characterized using X-ray diffraction, optical absorption and electrical conductivity measurements. These zinc oxide films are very transparent and photoconductive

  17. The optimization of the analysis of nickel-63 in urine

    International Nuclear Information System (INIS)

    Kramer, G.H.

    1981-05-01

    A method has been developed that separates nickel-63 from urine. The subsequent estimation of activity is by liquid scintillation counting. The urine is wet ashed by a new procedure which is much faster than conventional ashing methods. Interfering phosphates are removed prior to a precipitation of Ni as the dimethylglyoxime complex. The effects of the carrier weight, the pH of the phosphate removal step and the pH of the dimethylglyoxime precipiation have been investigated and optimized to give a mean recovery of 97 +- 8% for nickel-63. The detection limit is estimated to be 1.5 pCi (55 mBq) per sample. (author)

  18. Micropatterning of nanocomposite polymer scaffolds using sacrificial phosphate glass fibers for tendon tissue engineering applications.

    Science.gov (United States)

    Alshomer, Feras; Chaves, Camilo; Serra, Tiziano; Ahmed, Ifty; Kalaskar, Deepak M

    2017-04-01

    This study presents a simple and reproducible method of micropatterning the novel nanocomposite polymer (POSS-PCU) using a sacrificial phosphate glass fiber template for tendon tissue engineering applications. The diameters of the patterned scaffolds produced were dependent on the diameter of the glass fibers (15 μm) used. Scaffolds were tested for their physical properties and reproducibility using various microscopy techniques. For the first time, we show that POSS-PCU supports growth of human tenocytes cells. Furthermore, we show that cellular alignment, their biological function and expression of various tendon related proteins such as scleraxis, collagen I and III, tenascin-C are significantly elevated on the micropatterned polymer surfaces compared to flat samples. This study demonstrated a simple, reproducible method of micropatterning POSS-PCU nanocomposite polymer for novel tendon repair applications, which when provided with physical cues could help mimic the microenvironment of tenocytes cells. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Raman and FTIR spectra of CeO{sub 2} and Gd{sub 2}O{sub 3} in iron phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Lai, Yuanming, E-mail: laiyuanming@ipm.com.cn [State Key Laboratory of Advanced Technologies for Comprehensive Utilization of Platinum Metals, Kunming Institute of Precious Metals, Kunming 650106 (China); State Key Laboratory Cultivation Base for Nonmetal Composite and Functional Materials, Southwest University of Science and Technology, Mianyang 621010 (China); Liang, Xiaofeng; Yang, Shiyuan [State Key Laboratory Cultivation Base for Nonmetal Composite and Functional Materials, Southwest University of Science and Technology, Mianyang 621010 (China); Liu, Pei; Zeng, Yiming; Hu, Changyi [State Key Laboratory of Advanced Technologies for Comprehensive Utilization of Platinum Metals, Kunming Institute of Precious Metals, Kunming 650106 (China)

    2014-12-25

    Highlights: • The structure of the studied samples has been investigated by Raman and FTIR spectroscopy. • The structure for the all samples has similar features. • The structure consists of predominantly Q{sup 1} with a fraction of Q{sup 0} and Q{sup 2} units. • The Ce and Gd enters in the structure of studied glasses as a network modifier. - Abstract: In the present work, multicomponent oxide samples of composition x(CeO{sub 2} + Gd{sub 2}O{sub 3})–(40 − x)Fe{sub 2}O{sub 3}–60P{sub 2}O{sub 5} (0 ⩽ x ⩽ 8 mol%) were produced by conventional melting method. The samples were investigated to examine the effect of the CeO{sub 2} and Gd{sub 2}O{sub 3} composition on the structure of the iron phosphate glasses system. The X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM) for the x ⩽ 6 mol% samples show all the samples formed homogeneous glass, but for the x = 8 mol% samples show the presence of randomly distributed crystalline phase embedded in an amorphous matrix. The x(CeO{sub 2} + Gd{sub 2}O{sub 3})–(40 − x)Fe{sub 2}O{sub 3}–60P{sub 2}O{sub 5} glass containing 8 mol% CeO{sub 2} and Gd{sub 2}O{sub 3} partially crystallized during annealing and Ce/Gd-rich were identified by EDS in the crystalline phase. The structure of the studied samples has been investigated using Raman and Fourier transform infrared spectroscopy (FTIR). The Raman and FTIR spectra for the samples have analogous spectral features. The Raman and FTIR spectra suggest that the structure is mainly constituted by the pyrophosphate glass based structure, with a part proportion of metaphosphate and orthophosphate structure. Raman and FTIR spectra allowed us to identify the structural units which appear in the structural network of these phosphate glasses and also the network modifier role of cerium and gadolinium ions.

  20. Corrosion protection of metals by phosphate coatings and ecologically beneficial alternatives. Properties and mechanisms

    International Nuclear Information System (INIS)

    Weng Duan.

    1995-01-01

    The corrosion and protection characteristics of inorganic zinc and manganese phosphate coatings in aqueous solution have been examined by physical methods, accelerated corrosion tests and electrochemical polarization and impedance measurements. Some water-soluble organic films have been evaluated for the temporary protection of metal parts as the ecologically beneficial alternatives to phosphate coatings. The results show that zinc phosphate is a better insulator than manganese phosphate, but the porosity of the former is inferior to that of the latter. In neutral and alkaline solutions the anodic current of both zinc and manganese phosphates decreases and their open potential moves in a positive direction. In acidic medium both the polarization current and the open potential are close to those of the substrate. Confirmed by the impedance measurements, the corrosion of phosphated steel in acidic solution is controlled by a dissolution reaction, in neutral medium is first reaction controlled then diffusion controlled, and in alkaline environment only diffusion controlled. The insulation of acrylate+copolymer, epoxy and inhibitor+bonding materials is superior to that of zinc or manganese phosphates. In general, most of the alternatives can afford a better temporary protection for metal parts compared to inorganic phosphate coatings. The corrosion failure of inorganic phosphate coatings is mainly induced by the electrochemical dissolution of the substrate. This electrochemical process initiates at the bottom of the pores within the coating. In neutral solution, the hydrolysis of corrosion products decrease the pH value of the solution in the anodic zone, resulting in an acidic dissolution of phosphate coatings. At the same time, the depolarization of oxygen increases the pH value in the cathodic zone, causing an alkaline hydrolysis of phosphates. (author) figs., tabs., 149 refs

  1. A simple method for tuning the glass transition process in inorganic phosphate glasses

    OpenAIRE

    Fulchiron, Ren?; Belyamani, Imane; Otaigbe, Joshua U.; Bounor-Legar?, V?ronique

    2015-01-01

    The physical modification of glass transition temperature (Tg ) and properties of materials via blending is a common practice in industry and academia and has a large economic advantage. In this context, simple production of hitherto unattainable new inorganic glass blends from already existing glass compositions via blending raises much hope with the potential to provide new glasses with new and improved properties, that cannot be achieved with classical glass synthesis, for a plethora of ap...

  2. Bioleaching of Primary Nickel Ore Using Acidithiobacillus ferrooxidans LR Cells Immobilized in Glass Beads

    Directory of Open Access Journals (Sweden)

    Ellen Cristine Giese

    2015-06-01

    Full Text Available Sulphide minerals are one of the most important sources of value metals. For several years, a large number of hydrometallurgical and biotechnological processes have been developed to leach low-grade sulphide ores and the conditions are well established. However, the management of microorganisms in the bioleaching process is not easy to handle. In this paper, the use of immobilized cells of Acidithiobacillus ferrooxidans LR in glass beads in bioleaching of primary nickel ore was evaluated. The column experiments inoculated with immobilized cells of A. ferrooxidans LR showed the same efficiency than the conventional method using free cells and is promising for application on a larger scale as it ensuring integrity and activity of biomining microorganisms and reduce process costs. DOI: http://dx.doi.org/10.17807/orbital.v7i2.698 

  3. 40 CFR 302.6 - Notification requirements.

    Science.gov (United States)

    2010-07-01

    ..., phosphate, tin, zircon, hafnium, vanadium, monazite, and rare earth mines. Land disturbance incidental to..., chromium, copper, lead, nickel, selenium, silver, thallium, or zinc is not required if the mean diameter of...

  4. Luminescence studies on Dy3+ and Dy3+:Eu3+ co-doped boro-phosphate glasses for WLED applications

    Science.gov (United States)

    Vijayakumar, M.; Uma, V.; Arunkumar, S.; Marimuthu, K.

    2015-06-01

    Dy3+ and Dy3+:Eu3+ co-doped boro-phosphate glasses have been prepared and optically characterized using absorption, luminescence and decay measurements. The Nephelauxetic ratios (β), Bonding parameters (δ) and Judd-Ofelt (JO) intensity parameters Ωλ (λ = 2, 4 and 6) were calculated to study the nature of the environment around the RE3+ ions in the prepared glasses. The yellow to blue (Y/B) intensity ratio and the chromaticity color coordinates were calculated from the luminescence measurements. The lifetimes of the 4F9/2 excited level were measured using decay curves and is found to decrease in the Dy3+:Eu3+ co-doped glass due to the occurrence of resonant energy transfer between Dy3+-Eu3+ ions and the non-exponential decay rates have been fitted with Inokuti-Hirayama (IH) model. The decay curves are well fitted for S= 6 suggesting that the interaction between active ions for the energy transfer is of dipole-dipole nature.

  5. Tris(trimethylsilyl)phosphate as electrolyte additive for self-discharge suppression of layered nickel cobalt manganese oxide

    International Nuclear Information System (INIS)

    Liao, Xiaolin; Zheng, Xiongwen; Chen, Jiawei; Huang, Ziyu; Xu, Mengqing; Xing, Lidan; Liao, Youhao; Lu, Qilun; Li, Xiangfeng; Li, Weishan

    2016-01-01

    Highlights: • TMSP is effective for self-discharge suppression of the charged NCM under 4.5 V. • TMSP oxidizes preferentially forming protective cathode interface film on NCM. • The film suppresses electrolyte decomposition and prevents NCM destruction. - Abstract: Application of layered nickel cobalt manganese oxide as cathode under higher potential than conventional 4.2 V yields a significant improvement in energy density of lithium ion battery. However, the cathode fully charged under high potential suffers serious self-discharge, in which the interaction between the cathode and electrolyte proceeds without potential limitation. In this work, we use tris(trimethylsilyl)phosphate (TMSP) as an electrolyte additive to solve this problem. A representative layered nickel cobalt manganese oxide, LiNi 1/3 Co 1/3 Mn 1/3 O 2 , is considered. The effect of TMSP on self-discharge behavior of LiNi 1/3 Co 1/3 Mn 1/3 O 2 is evaluated by physical and electrochemical methods. It is found that the self-discharge of charged LiNi 1/3 Co 1/3 Mn 1/3 O 2 can be suppressed significantly by using TMSP. TMSP is oxidized preferentially in comparison with the standard electrolyte during initial charging process forming a protective cathode interface film, which avoids the interaction between cathode and electrolyte at any potential and thus prevents electrolyte decomposition and protects LiNi 1/3 Co 1/3 Mn 1/3 O 2 from structure destruction.

  6. Evaluation of chemical phenomena that could have an effect on the performance of recirculation strainers in a Ringhals PWR

    International Nuclear Information System (INIS)

    Liljenzin, Jan-Olov

    2005-01-01

    An evaluation has been made of the various chemical phenomena that could have an effect on the performance of recirculation strainers after a LOCA in a PWR. Values of pH and concentrations in the water at the bottom of the containment have been calculated as functions of time and temperature for a postulated LOCA. The behaviour of glass wool insulation, its dissolution, and precipitation of amorphous silic acid have been evaluated. Also the corrosion of galvanized surfaces has been considered. Dissolution of zinc by hot boric acid solution can lead to a later precipitation of amorphous zinc hydroxide or phosphate when pH increases and temperature drops. Also a possible growth of microorganisms is discussed. A rough classification of the various phenomena possible along a simplified time scale yields the following conclusions: Hours after the beginning of the LOCA: Precipitation of zinc hydroxide and/or phosphate. Dissolution of glass wool giving rise to an increasing concentration of silic acid in the water. Days after the beginning of the LOCA: Continued dissolution of glass wool and increasing concentration of silica in the water. Perhaps a precipitation of phosphates or carbonates of the metal ions released during dissolution of glass wool. Weeks after the beginning of the LOCA: Continued slow dissolution of glass wool leading to a risk of precipitation of amorphous silica. Perhaps a precipitation of phosphates or carbonates of the metal ions released during dissolution of glass wool. Initial growth of microorganisms in the water and on surfaces after mutations and adaptation to the existing environment. Months after the beginning of the LOCA: Continued slow dissolution of glass wool leading to a risk of precipitation of amorphous silica. Perhaps a precipitation of phosphates or carbonates of the metal ions released during dissolution of glass wool. Continued growth of adapted microorganisms

  7. Effect of phosphate-based glass fibre surface properties on thermally produced poly(lactic acid) matrix composites.

    Science.gov (United States)

    Mohammadi, Maziar Shah; Ahmed, Ifty; Muja, Naser; Rudd, Christopher D; Bureau, Martin N; Nazhat, Showan N

    2011-12-01

    Incorporation of soluble bioactive glass fibres into biodegradable polymers is an interesting approach for bone repair and regeneration. However, the glass composition and its surface properties significantly affect the nature of the fibre-matrix interface and composite properties. Herein, the effect of Si and Fe on the surface properties of calcium containing phosphate based glasses (PGs) in the system (50P(2)O(5)-40CaO-(10-x)SiO(2)-xFe(2)O(3), where x = 0, 5 and 10 mol.%) were investigated. Contact angle measurements revealed a higher surface energy, and surface polarity as well as increased hydrophilicity for Si doped PG which may account for the presence of surface hydroxyl groups. Two PG formulations, 50P(2)O(5)-40CaO-10Fe(2)O(3) (Fe10) and 50P(2)O(5)-40CaO-5Fe(2)O(3)-5SiO(2) (Fe5Si5), were melt drawn into fibres and randomly incorporated into poly(lactic acid) (PLA) produced by melt processing. The ageing in deionised water (DW), mechanical property changes in phosphate buffered saline (PBS) and cytocompatibility properties of these composites were investigated. In contrast to Fe10 and as a consequence of the higher surface energy and polarity of Fe5Si5, its incorporation into PLA led to increased inorganic/organic interaction indicated by a reduction in the carbonyl group of the matrix. PLA chain scission was confirmed by a greater reduction in its molecular weight in PLA-Fe5Si5 composites. In DW, the dissolution rate of PLA-Fe5Si5 was significantly higher than that of PLA-Fe10. Dissolution of the glass fibres resulted in the formation of channels within the matrix. Initial flexural strength was significantly increased through PGF incorporation. After PBS ageing, the reduction in mechanical properties was greater for PLA-Fe5Si5 compared to PLA-Fe10. MC3T3-E1 preosteoblasts seeded onto PG discs, PLA and PLA-PGF composites were evaluated for up to 7 days indicating that the materials were generally cytocompatible. In addition, cell alignment along the PGF

  8. Long-term progress prediction for the carbon steel corrosion in diluted artificial seawater with and without zinc / sodium carbonate mixed phosphate

    International Nuclear Information System (INIS)

    Fujii, Kazumi; Ishioka, Shinichi; Iwanami, Masaru; Kaneko, Tetsuji; Tanaka, Norihiko; Kawaharada, Yoshiyuki; Yokoyama, Yutaka; Umehara, Ryuji; Kato, Chiaki; Ueno, Fumiyoshi; Fukaya, Yuichi; Kumaga, Katsuhiko

    2017-01-01

    The Fukushima Daiichi Nuclear Power Plants (1F) were damaged by an unprecedented severe accident in the great east Japan earthquake on 11th, March, 2011, and seawater and fresh water were injected as an emergency countermeasure for the core cooling. The primary containment vessels (PCVs), made of carbon steel, were exposed to seawater and fresh water, and have had the possibility of corrosion. The PCVs of 1F are the most important equipment for the core cooling and removal of the fuel debris, the structural integrity of the PCV must be maintained until decommissioning. Therefore, evaluation of PCV carbon steel corrosion behavior is important, as well as evaluation of corrosion inhibitors as one of the corrosion protection methods. In this study, long-term immersion corrosion tests for up to 10000 hours were performed in diluted artificial seawater simulating 1F with and without zinc / sodium carbonate mixed phosphate. Based on the long-term immersion corrosion test results, diagnosis method of the reduction in plate thickness of the nuclear vessel was examined. The validity of the existing corrosion progress models following parabolic rate law was confirmed. The corrosion progress models were also applicable to the corrosion inhibited condition adding zinc / sodium carbonate mixed phosphate. It was found that the corrosion rate of carbon steel drastically fell down by adding this corrosion inhibitor. (author)

  9. Investigations into Recycling Zinc from Used Metal Oxide Varistors via pH Selective Leaching: Characterization, Leaching, and Residue Analysis

    Science.gov (United States)

    Gutknecht, Toni; Gustafsson, Anna; Forsgren, Christer; Steenari, Britt-Marie

    2015-01-01

    Metal oxide varistors (MOVs) are a type of resistor with significantly nonlinear current-voltage characteristics commonly used in power lines to protect against overvoltages. If a proper recycling plan is developed MOVs can be an excellent source of secondary zinc because they contain over 90 weight percent zinc oxide. The oxides of antimony, bismuth, and to a lesser degree cobalt, manganese, and nickel are also present in varistors. Characterization of the MOV showed that cobalt, nickel, and manganese were not present in the varistor material at concentrations greater than one weight percent. This investigation determined whether a pH selective dissolution (leaching) process can be utilized as a starting point for hydrometallurgical recycling of the zinc in MOVs. This investigation showed it was possible to selectively leach zinc from the MOV without coleaching of bismuth and antimony by selecting a suitable pH, mainly higher than 3 for acids investigated. It was not possible t