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Sample records for borosilicate glass tailored

  1. Topological Principles of Borosilicate Glass Chemistry

    DEFF Research Database (Denmark)

    Smedskjær, Morten Mattrup; Mauro, J. C.; Youngman, R. E.

    2011-01-01

    Borosilicate glasses display a rich complexity of chemical behavior depending on the details of their composition and thermal history. Noted for their high chemical durability and thermal shock resistance, borosilicate glasses have found a variety of important uses from common household...... and laboratory glassware to high-tech applications such as liquid crystal displays. In this paper, we investigate the topological principles of borosilicate glass chemistry covering the extremes from pure borate to pure silicate end members. Based on NMR measurements, we present a two-state statistical...... earthborosilicate glasses that enables the accurate prediction of properties such as glass transition temperature, liquid fragility, and hardness. The modeling approach enables an understanding of the microscopic mechanisms governing macroscopic properties. The implications of the glass topology are discussed...

  2. Topological principles of borosilicate glass chemistry.

    Science.gov (United States)

    Smedskjaer, Morten M; Mauro, John C; Youngman, Randall E; Hogue, Carrie L; Potuzak, Marcel; Yue, Yuanzheng

    2011-11-10

    Borosilicate glasses display a rich complexity of chemical behavior depending on the details of their composition and thermal history. Noted for their high chemical durability and thermal shock resistance, borosilicate glasses have found a variety of important uses from common household and laboratory glassware to high-tech applications such as liquid crystal displays. In this paper, we investigate the topological principles of borosilicate glass chemistry covering the extremes from pure borate to pure silicate end members. Based on NMR measurements, we present a two-state statistical mechanical model of boron speciation in which addition of network modifiers leads to a competition between the formation of nonbridging oxygen and the conversion of boron from trigonal to tetrahedral configuration. Using this model, we derive a detailed topological representation of alkali-alkaline earth-borosilicate glasses that enables the accurate prediction of properties such as glass transition temperature, liquid fragility, and hardness. The modeling approach enables an understanding of the microscopic mechanisms governing macroscopic properties. The implications of the glass topology are discussed in terms of both the temperature and thermal history dependence of the atomic bond constraints and the influence on relaxation behavior. We also observe a nonlinear evolution of the jump in isobaric heat capacity at the glass transition when substituting SiO(2) for B(2)O(3), which can be accurately predicted using a combined topological and thermodynamic modeling approach.

  3. Damage Development in Confined Borosilicate and Soda-Lime Glasses

    Science.gov (United States)

    2011-07-11

    Elmira, NY). BF is a borosilicate glass manufactured by Schott Glass using a float process. SP float glass is a crystal clear, soda-lime glass . This...2005. 22 21. ASTM £494, "Technique for Measuring Ultrasonic Velocity in Materials", July 2001. 22. Schott Glass , Borofloat 33 Thermal Properties...21945 Damage Development in Conf"med Borosilicate and Soda-Lime Glasses Kathryn A. Dannemann1, Charles E. Anderson. Jr. 1, Sidney Chocron1, James

  4. Topological Principles of Borosilicate Glass Chemistry - An Invited Talk

    DEFF Research Database (Denmark)

    Mauro, J.C.; Smedskjær, Morten Mattrup; Youngman, R. E.

    Borosilicate glasses display a rich complexity of chemical behavior depending on the details of their composition and thermal history. We investigate the topological principles of borosilicate glass chemistry covering the extremes from pure borate to pure silicate end members. Based on NMR...... topological representation of alkali-alkaline earth-borosilicate glasses that enables the accurate prediction of properties such as glass transition temperature, liquid fragility, hardness, and configurational heat capacity. The implications of the glass topology are discussed in terms of both the temperature...

  5. Using of borosilicate glass waste as a cement additive

    Energy Technology Data Exchange (ETDEWEB)

    Han, Weiwei [State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan, Hubei 430070 (China); School of Civil Engineering and Architecture, Wuhan University of Technology, Wuhan, Hubei 430070 (China); Sun, Tao, E-mail: sunt@whut.edu.cn [State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan, Hubei 430070 (China); Key Laboratory of Roadway Bridge & Structure Engineering, Wuhan University of Technology, Wuhan, Hubei 430070 (China); Li, Xinping [Key Laboratory of Roadway Bridge & Structure Engineering, Wuhan University of Technology, Wuhan, Hubei 430070 (China); Sun, Mian [School of Materials Science and Engineering, Wuhan University of Technology, Wuhan, Hubei 430070 (China); Lu, Yani [Urban Construction Institute, Hubei Engineering University, Xiaogan, Hubei 432000 (China)

    2016-08-15

    Highlights: • Borosilicate glass waste used as cement additive can improves its radiation shielding. • When content is 14.8%, the linear attenuation coefficient is 0.2457 cm{sup −1} after 28 d. • From 0 to 22.2%, linear attenuation coefficient firstly increase and then decrease. - Abstract: Borosilicate glass waste is investigated as a cement additive in this paper to improve the properties of cement and concrete, such as setting time, compressive strength and radiation shielding. The results demonstrate that borosilicate glass is an effective additive, which not only improves the radiation shielding properties of cement paste, but also shows the irradiation effect on the mechanical and optical properties: borosilicate glass can increase the compressive strength and at the same time it makes a minor impact on the setting time and main mineralogical compositions of hydrated cement mixtures; and when the natural river sand in the mortar is replaced by borosilicate glass sand (in amounts from 0% to 22.2%), the compressive strength and the linear attenuation coefficient firstly increase and then decrease. When the glass waste content is 14.8%, the compressive strength is 43.2 MPa after 28 d and the linear attenuation coefficient is 0.2457 cm{sup −1} after 28 d, which is beneficial for the preparation of radiation shielding concrete with high performances.

  6. Relaxation Behaviour of Lithium-Borosilicate Glasses

    Directory of Open Access Journals (Sweden)

    D. B. Thombre

    2014-01-01

    Full Text Available Three systems of lithium borosilicate (LBS glasses namely SI 42.5Li2O: (57.5-x B2O3: xSiO2, SII 42.5Li2O: xB2O3 :( 57.5-x SiO2 where x=0, 5, 10, 20, and 30, and SIII (100-2x Li2O: xB2O3: xSiO2 where x=30, 28.75, 27.5, 25, and 22.5, are prepared using conventional melt quenching technique. Functional dependence of conductivity on temperature in the range from 523- 673K and frequency in the range from 10Hz to 13 MHz is studied. In order to analyze electrical conductivity the microscopic parameters such as ionic jump distance and barrier height are necessary. These parameters can be understood properly on the basis of the models proposed by Almond and Elliott. As frequency increases from 1MHz to 13MHz, the Tmin shifts towards low temperature side. According to this model the charge transfer is a thermally activated process and provides a correlation between the barrier height (W and the hopping length (R. The fitting of conductivity data into Almond-West type power law behavior σ = σ(o + Aωs yielded power law exponent(s. Electrical conductivity data fitted well in Elliott’s model, which is true only for amorphous materials. The temperature dependence of frequency exponent s exhibits a minimum (smin at a particular temperature (Tmin . . From the scaling behavior of the ac conductivity it is seen that all the curves scaled better, suggesting that s is temperature independent. It is observed that smin shifts to lower temperature, which shows that electrical conductivity of glassy solid electrolytes is the manifestation of ionic dynamic processes. The superposition of the reduced conductivity at all temperatures shows relaxation mechanism is temperature independent. Analysis of modulus formalism with a distribution of relaxation times using KWW stretched exponential function, the stretching exponent, β, is depend on temperature. The analysis of the temperature variation of the M″ peak indicates the relaxation process is thermally activated

  7. Er3+-Yb3+ codoped borosilicate glass for optical thermometry

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Infrared to green up-conversion emissions centered at the wavelengths of about 524 and 550 nm of the Er3+-Yb3+ codoped borosilicate glass are recorded,using a 978 nm semiconductor laser diode(LD) as an excitation source.The fluorescence intensity ratio(FIR) of the green up-conversion emissions at about 524 and 550 nm in the Er3+-Yb3+ codoped borosilicate glass has been studied as a function of temperature over the temperature range of 295-873 K.The maximum sensitivity and the temperature resolution derived from the FIR of the green up-conversion emissions are approximately 0.0038 K-1 and 0.2 K,respectively.It is demonstrated that the prototype optical temperature sensor based on the FIR technique from the green up-conversion emissions in the Er3+-Yb3+ codoped borosilicate glass plays a major role in temperature measurement.

  8. Using of borosilicate glass waste as a cement additive

    Science.gov (United States)

    Han, Weiwei; Sun, Tao; Li, Xinping; Sun, Mian; Lu, Yani

    2016-08-01

    Borosilicate glass waste is investigated as a cement additive in this paper to improve the properties of cement and concrete, such as setting time, compressive strength and radiation shielding. The results demonstrate that borosilicate glass is an effective additive, which not only improves the radiation shielding properties of cement paste, but also shows the irradiation effect on the mechanical and optical properties: borosilicate glass can increase the compressive strength and at the same time it makes a minor impact on the setting time and main mineralogical compositions of hydrated cement mixtures; and when the natural river sand in the mortar is replaced by borosilicate glass sand (in amounts from 0% to 22.2%), the compressive strength and the linear attenuation coefficient firstly increase and then decrease. When the glass waste content is 14.8%, the compressive strength is 43.2 MPa after 28 d and the linear attenuation coefficient is 0.2457 cm-1 after 28 d, which is beneficial for the preparation of radiation shielding concrete with high performances.

  9. 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.

  10. Ultrafast laser fabrication of submicrometer pores in borosilicate glass.

    Science.gov (United States)

    An, Ran; Uram, Jeffrey D; Yusko, Erik C; Ke, Kevin; Mayer, Michael; Hunt, Alan J

    2008-05-15

    We demonstrate rapid fabrication of submicrometer-diameter pores in borosilicate glass using femtosecond laser machining and subsequent wet-etch techniques. This approach allows direct and repeatable fabrication of high-quality pores with diameters of 400-800 nm. Such small pores coupled with the desirable electrical and chemical properties of glass enable sensitive resistive-pulse analysis to determine the size and concentration of macromolecules and nanoparticles. Plasma-enhanced chemical vapor deposition allows further reduction of pore diameters to below 300 nm.

  11. Electrical conductivity and viscosity of borosilicate glasses and melts

    DEFF Research Database (Denmark)

    Ehrt, Doris; Keding, Ralf

    2009-01-01

    , 0 to 62·5 mol% B2O3, and 25 to 85 mol% SiO2. The glass samples were characterised by different methods. Refractive indices, density and thermal expansion were measured. Phase separation effects were investigated by electron microscopy. The electrical conductivity of glasses and melts were determined...... by impedance measurements in a wide temperature range (250 to 1450°C). The activation energies were calculated by Arrhenius plots in various temperature regions: below the glass transition temperature, Tg, above the melting point, Tl, and between Tg and Tl. Viscosity measurements were carried out...... with different methods from Tg to the melt. The measured data were fitted and the activation energies calculated. Simple exponential behaviour was found only in very narrow temperature ranges. The effect of B2O3 in sodium borosilicate glasses and melts is discussed in comparison with sodium silicate glasses...

  12. Enhancement of thermal neutron shielding of cement mortar by using borosilicate glass powder.

    Science.gov (United States)

    Jang, Bo-Kil; Lee, Jun-Cheol; Kim, Ji-Hyun; Chung, Chul-Woo

    2017-05-01

    Concrete has been used as a traditional biological shielding material. High hydrogen content in concrete also effectively attenuates high-energy fast neutrons. However, concrete does not have strong protection against thermal neutrons because of the lack of boron compound. In this research, boron was added in the form of borosilicate glass powder to increase the neutron shielding property of cement mortar. Borosilicate glass powder was chosen in order to have beneficial pozzolanic activity and to avoid deleterious expansion caused by an alkali-silica reaction. According to the experimental results, borosilicate glass powder with an average particle size of 13µm showed pozzolanic activity. The replacement of borosilicate glass powder with cement caused a slight increase in the 28-day compressive strength. However, the incorporation of borosilicate glass powder resulted in higher thermal neutron shielding capability. Thus, borosilicate glass powder can be used as a good mineral additive for various radiation shielding purposes.

  13. Commercial Ion Exchange Resin Vitrification in Borosilicate Glass

    Energy Technology Data Exchange (ETDEWEB)

    Cicero-Herman, C.A.; Workman, P. [Westinghouse Savannah River Co., Aiken, SC (United States); Poole, K.; Erich, D.; Harden, J. [Clemson Environmental Technologies Laboratory, Anderson, SC (United States)

    1998-05-01

    Bench-scale studies were performed to determine the feasibility of vitrification treatment of six resins representative of those used in the commercial nuclear industry. Each resin was successfully immobilized using the same proprietary borosilicate glass formulation. Waste loadings varied from 38 to 70 g of resin/100 g of glass produced depending on the particular resin, with volume reductions of 28 percent to 68 percent. The bench-scale results were used to perform a melter demonstration with one of the resins at the Clemson Environmental Technologies Laboratory (CETL). The resin used was a weakly acidic meth acrylic cation exchange resin. The vitrification process utilized represented a approximately 64 percent volume reduction. Glass characterization, radionuclide retention, offgas analyses, and system compatibility results will be discussed in this paper.

  14. Behaviour of ruthenium dioxide particles in borosilicate glasses and melts

    Science.gov (United States)

    Pflieger, Rachel; Lefebvre, Leila; Malki, Mohammed; Allix, Mathieu; Grandjean, Agnès

    2009-06-01

    Ruthenium-glass systems are formed during the vitrification of nuclear waste. They are also widely used in micro-electronics because of their unique electrical properties. However, the interaction of this element with the glass matrix remains poorly understood. This work focuses on a RuO 2 particles-nuclear alumino-borosilicate glass system in which the electrical conductivity is known to vary considerably with the RuO 2 content and to become electronic above about 0.5-0.7 vol.% RuO 2 [R. Pflieger, M. Malki, Y. Guari, J. Larionova, A. Grandjean, J. Am. Ceram. Soc., accepted for publication]. Some RuO 2 segregation was observed in SEM/TEM investigations but no continuous chain of RuO 2 particles could be seen. Electron relays between the particles are then necessary for a low-rate percolation, such as the nanoclusters suggested by Adachi et al. [K. Adachi, S. Iida, K. Hayashi, J. Mater. Res. 9 (7) (1994) 1866; K. Adachi, H. Kuno, J. Am. Ceram. Soc. 83 (10) (2000) 2441], which could consist in dissolved ruthenium. Indeed, several observations made here clearly indicate the presence of dissolved ruthenium in the glass matrix, like the modification of the glass density in presence of RuO 2 particles or the diffusion-limited growth of RuO 2 particles in the melt.

  15. Morphological study of borosilicate glass surface irradiated by heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Wang, T. S.; Du, X.; Yuan, W.; Duan, B. H.; D. Zhang, J.; Chen, L.; Peng, H. B.; Yang, D.; Zhang, G. F.; Zhu, Z. H.

    2016-11-01

    Borosilicate glass is a candidate material for radiation waste formation and other optical applications in various fields. To understand the radiation effect of borosilicate glass, heavy ion (Arq+, Krq+ and Xeq+) irradiations were used to simulate the alpha and recoiled nuclei irradiations in this study. The surface morphology of glass has been compared to ion irradiation doses and ion energies. The surface topography evolution of irradiated samples is characterized by optical microscopy, atomic force microscopy (AFM), transmission electron microscopy (TEM) and secondary ion mass spectrometry (SIMS). Micro-bumps are observed on the sample surface after irradiationwith 5 MeV Xeq+ over 5 × 1013 ions·cm-2. The size and density of the bumps increaseswith increasing irradiation dose. At a lowdose, bumps are on the nanometer (nm) scale and rather rare.While the dose is higher than 9 × 1015 ions·cm-2, the size of bumps is on the scale of a few microns, and the density is saturated. However, the height of the bumps increases froma fewnmto over 150nmwith further irradiation. The distribution of micro-bumps is nearly homogeneous. The bumps are condensed and swell up, and there is no crystallized structure according to the TEMdiffraction pattern. Elementmigration and concentrations are observedwith SIMS imaging. The arrayed micro-bumps are a new finding, and they might be used to change the surface properties. Bump formation is caused by phase separation, and volume swelling is induced by ion irradiation.

  16. Surface Devitrification and the Growth of Cristobalite in Borofloat® (Borosilicate 8330) Glass

    NARCIS (Netherlands)

    Mogulkoc, Berker; Knowles, Kevin M.; Jansen, Henri V.; Brake, ter Marcel; Elwenspoek, Miko C.

    2010-01-01

    Borofloat® (borosilicate 8330) glass is an important type of inorganic glass, both scientifically and commercially. During prolonged heat treatment of this glass above its glass transition temperature of 525°C, heterogeneous nucleation, and growth of cristobalite crystals occur. The kinetics and mor

  17. Magnetic Glass Ceramics by Sintering of Borosilicate Glass and Inorganic Waste

    Directory of Open Access Journals (Sweden)

    Inès M. M. M. Ponsot

    2014-07-01

    Full Text Available Ceramics and glass ceramics based on industrial waste have been widely recognized as competitive products for building applications; however, there is a great potential for such materials with novel functionalities. In this paper, we discuss the development of magnetic sintered glass ceramics based on two iron-rich slags, coming from non-ferrous metallurgy and recycled borosilicate glass. The substantial viscous flow of the glass led to dense products for rapid treatments at relatively low temperatures (900–1000 °C, whereas glass/slag interactions resulted in the formation of magnetite crystals, providing ferrimagnetism. Such behavior could be exploited for applying the obtained glass ceramics as induction heating plates, according to preliminary tests (showing the rapid heating of selected samples, even above 200 °C. The chemical durability and safety of the obtained glass ceramics were assessed by both leaching tests and cytotoxicity tests.

  18. Comparison of mechanical properties of glass-bonded sodalite and borosilicate glass high-level waste forms

    Energy Technology Data Exchange (ETDEWEB)

    O' Holleran, T. P.; DiSanto, T.; Johnson, S. G.; Goff, K. M.

    2000-05-09

    Argonne National Laboratory has developed a glass-bonded sodalite waste form to immobilize the salt waste stream from electrometallurgical treatment of spent nuclear fuel. The waste form consists of 75 vol.% crystalline sodalite and 25 vol.% glass. Microindentation fracture toughness measurements were performed on this material and borosilicate glass from the Defense Waste Processing Facility using a Vickers indenter. Palmqvist cracking was confined for the glass-bonded sodalite waste form, while median-radial cracking occurred in the borosilicate glass. The elastic modulus was measured by an acoustic technique. Fracture toughness, microhardness, and elastic modulus values are reported for both waste forms.

  19. Quantification of the boron speciation in alkali borosilicate glasses by electron energy loss spectroscopy

    DEFF Research Database (Denmark)

    Cheng, Shaodong; Yang, Guang; Zhao, Yanqi;

    2015-01-01

    developed a method based on electron energy loss spectroscopy (EELS) data acquisition and analyses, which enables determination of the boron speciation in a series of ternary alkali borosilicate glasses with constant molar ratios. A script for the fast acquisition of EELS has been designed, from which...... fraction in glasses. In addition, the boron speciation of a CeO2 doped potassium borosilicate glass has been analyzed by using the time-resolved EELS spectra. The results clearly demonstrate that the BO4 to BO3 transformation induced by the electron beamirradiation can be efficiently suppressed by doping...

  20. Modelling the evaporation of boron species. Part 1: Alkali-free borosilicate glass melts

    NARCIS (Netherlands)

    Limpt, J.A.C. van; Beerkens, R.G.C.; Cook, S.; O'Connor, R.; Simon, J.

    2011-01-01

    A laboratory test facility has been used to measure the boron evaporation rates from borosilicate glass melts. The impact of furnace atmosphere composition and glass melt composition on the temperature dependent boron evaporation rates has been investigated experimentally. In Part 1 of this paper th

  1. Atomic layer deposited borosilicate glass microchannel plates for large area event counting detectors

    Science.gov (United States)

    Siegmund, O. H. W.; McPhate, J. B.; Tremsin, A. S.; Jelinsky, S. R.; Hemphill, R.; Frisch, H. J.; Elam, J.; Mane, A.; Lappd Collaboration

    2012-12-01

    Borosilicate glass micro-capillary array substrates with 20 μm and 40 μm pores have been deposited with resistive, and secondary electron emissive, layers by atomic layer deposition to produce functional microchannel plates. Device formats of 32.7 mm and 20 cm square have been fabricated and tested in analog and photon counting modes. The tests show amplification, imaging, background rate, pulse shape and lifetime characteristics that are comparable to standard glass microchannel plates. Large area microchannel plates of this type facilitate the construction of 20 cm format sealed tube sensors with strip-line readouts that are being developed for Cherenkov light detection. Complementary work has resulted in Na2KSb bialkali photocathodes with peak quantum efficiency of 25% being made on borosilicate glass. Additionally GaN (Mg) opaque photocathodes have been successfully made on borosilicate microchannel plates.

  2. Characterization of MEMS-on-tube assembly: reflow bonding of borosilicate glass (Duran ®) tubes to silicon substrates

    NARCIS (Netherlands)

    Mogulkoc, B.; Jansen, H.V.; Berenschot, J.W.; Brake, ter H.J.M.; Knowles, K.M.; Elwenspoek, M.C.

    2009-01-01

    Reflow bonding of borosilicate glass tubes to silicon wafers is a technology which has significant potential for microfluidic applications. The borosilicate glass tubes are designed to be used as an interface and package for wafer-level microfluidic devices. The strength of the resulting package has

  3. Reflow bonding of borosilicate glass tubes to silicon substrates as fluidic interconnects

    NARCIS (Netherlands)

    Mogulkoc, Berker

    2010-01-01

    The subject of the thesis was the use of borosilicate glass tubes as an interface to waferlevel microfluidic devices. The tubes are compatible with the standard fluidic connectors and can be used as a package for the so-called MEMS-on-a-tube assembly. The connections are produced by the brief reflow

  4. High-level waste borosilicate glass: A compendium of corrosion characteristics. Volume 3

    Energy Technology Data Exchange (ETDEWEB)

    Cunnane, J.C. [comp.; Bates, J.K.; Bradley, C.R. [Argonne National Lab., IL (United States)] [and others

    1994-03-01

    The objective of this document is to summarize scientific information pertinent to evaluating the extent to which high-level waste borosilicate glass corrosion and the associated radionuclide release processes are understood for the range of environmental conditions to which waste glass may be exposed in service. Alteration processes occurring within the bulk of the glass (e.g., devitrification and radiation-induced changes) are discussed insofar as they affect glass corrosion. Volume III contains a bibliography of glass corrosion studies, including studies that are not cited in Volumes I and II.

  5. Influence of Cu doping in borosilicate bioactive glass and the properties of its derived scaffolds.

    Science.gov (United States)

    Wang, Hui; Zhao, Shichang; Xiao, Wei; Xue, Jingzhe; Shen, Youqu; Zhou, Jie; Huang, Wenhai; Rahaman, Mohamed N; Zhang, Changqing; Wang, Deping

    2016-01-01

    Copper doped borosilicate glasses (BG-Cu) were studied by means of FT-IR, Raman, UV-vis and NMR spectroscopies to investigate the changes that appeared in the structure of borosilicate glass matrix by doping copper ions. Micro-fil and immunohistochemistry analysis were applied to study the angiogenesis of its derived scaffolds in vivo. Results indicated that the Cu ions significantly increased the B-O bond of BO4 groups at 980 cm(-1), while they decrease that of BO2O(-) groups at 1440-1470 cm(-1) as shown by Raman spectra. A negative shift was observed from (11)B and (29)Si NMR spectra. The (11)B NMR spectra exhibited a clear transformation from BO3 into BO4 groups, caused by the agglutination effect of the Cu ions and the charge balance of the agglomerate in the glass network, leading to a more stable glass network and lower ions release rate in the degradation process. Furthermore, the BG-Cu scaffolds significantly enhanced blood vessel formation in rat calvarial defects at 8 weeks post-implantation. Generally, it suggested that the introduction of Cu into borosilicate glass endowed glass and its derived scaffolds with good properties, and the cooperation of Cu with bioactive glass may pave a new way for tissue engineering.

  6. High-level waste borosilicate glass a compendium of corrosion characteristics. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Cunnane, J.C. [comp.; Bates, J.K.; Bradley, C.R. [Argonne National Lab., IL (United States)

    1994-03-01

    Current plans call for the United States Department of Energy (DOE) to start up facilities for vitrification of high-level radioactive waste (HLW) stored in tanks at the Savannah River Site, Aiken, South Carolina, in 1995; West Valley Demonstration Project, West Valley, New York, in 1996; and at the Hanford Site, Richland, Washington, after the year 2000. The product from these facilities will be canistered HLW borosilicate glass, which will be stored, transported, and eventually disposed of in a geologic repository. The behavior of this glass waste product, under the range of likely service conditions, is the subject of considerable scientific and public interest. Over the past few decades, a large body of scientific information on borosilicate waste glass has been generated worldwide. The intent of this document is to consolidate information pertaining to our current understanding of waste glass corrosion behavior and radionuclide release. The objective, scope, and organization of the document are discussed in Section 1.1, and an overview of borosilicate glass corrosion is provided in Section 1.2. The history of glass as a waste form and the international experience with waste glass are summarized in Sections 1.3 and 1.4, respectively.

  7. Surface Morphology and Structure of Double-Phase Magnetic Alkali Borosilicate Glasses

    Science.gov (United States)

    Andreeva, N. V.; Naberezhnov, A. A.; Tomkovich, M. V.; Nacke, B.; Kichigin, V.; Rudskoy, A. I.; Filimonov, A. V.

    2016-11-01

    The surface morphology of double-phase magnetic alkali borosilicate glasses of four types obtained by induction melting is studied by the methods of atomic-force and scanning electron microscopy. The distribution of elements over the surface and the elemental composition of the glasses are determined. It is shown that a dendritic system of interrelated channels required for formation of porous matrixes with controlled mean pore diameter may be obtained in these objects depending on the heat treatment mode.

  8. PLUTONIUM SOLUBILITY IN HIGH-LEVEL WASTE ALKALI BOROSILICATE GLASS

    Energy Technology Data Exchange (ETDEWEB)

    Marra, J.; Crawford, C.; Fox, K.; Bibler, N.

    2011-01-04

    The solubility of plutonium in a Sludge Batch 6 (SB6) reference glass and the effect of incorporation of Pu in the glass on specific glass properties were evaluated. A Pu loading of 1 wt % in glass was studied. Prior to actual plutonium glass testing, surrogate testing (using Hf as a surrogate for Pu) was conducted to evaluate the homogeneity of significant quantities of Hf (Pu) in the glass, determine the most appropriate methods to evaluate homogeneity for Pu glass testing, and to evaluate the impact of Hf loading in the glass on select glass properties. Surrogate testing was conducted using Hf to represent between 0 and 1 wt % Pu in glass on an equivalent molar basis. A Pu loading of 1 wt % in glass translated to {approx}18 kg Pu per Defense Waste Processing Facility (DWPF) canister, or about 10X the current allowed limit per the Waste Acceptance Product Specifications (2500 g/m{sup 3} of glass or about 1700 g/canister) and about 30X the current allowable concentration based on the fissile material concentration limit referenced in the Yucca Mountain Project License Application (897 g/m{sup 3}3 of glass or about 600 g Pu/canister). Based on historical process throughput data, this level was considered to represent a reasonable upper bound for Pu loading based on the ability to provide Pu containing feed to the DWPF. The task elements included evaluating the distribution of Pu in the glass (e.g. homogeneity), evaluating crystallization within the glass, evaluating select glass properties (with surrogates), and evaluating durability using the Product Consistency Test -- Method A (PCT-A). The behavior of Pu in the melter was evaluated using paper studies and corresponding analyses of DWPF melter pour samples.The results of the testing indicated that at 1 wt % Pu in the glass, the Pu was homogeneously distributed and did not result in any formation of plutonium-containing crystalline phases as long as the glass was prepared under 'well-mixed' conditions

  9. Gamma-ray shielding and structural properties of barium-bismuth-borosilicate glasses

    Science.gov (United States)

    Bootjomchai, Cherdsak; Laopaiboon, Jintana; Yenchai, Chadet; Laopaiboon, Raewat

    2012-07-01

    The attenuation coefficients of barium-bismuth-borosilicate glasses have been measured for gamma-ray photon energies of 662, 1173 and 1332 keV using a narrow beam transmission geometry. These coefficients were then used to obtain the values of mass attenuation coefficients, effective atomic number, effective electron density and mean free path. Good agreement has been observed between experimental and theoretical values of these parameters. From the obtained results it is reported here that from the barium-bismuth-borosilicate glasses are better shields to gamma-radiations in comparison to the standard radiation shielding concretes from the shielding point of view. The molar volume, FTIR and acoustic investigations have been used to study the structural properties of the prepared glass system. The obtained results reveal that the formation of non-bridging oxygens occurs at higher concentration of Bi2O3.

  10. In-vitro bioactivity of zirconia doped borosilicate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Samudrala, Rajkumar; Azeem, P. Abdul, E-mail: rk.satyaswaroop@gmail.com, E-mail: drazeem2002@yahoo.com [Department of Physics, National Institute of Technology, Warangal-506004 (India)

    2015-06-24

    Glass composition 31B{sub 2}O{sub 3}-20SiO{sub 2}-24.5Na{sub 2}O-(24.5-x) CaO-xZrO{sub 2} x=1,2,3,4,5 were prepared by melt-quenching Technique. The formation of hydroxyapatite layer on the surface of glasses after immersion in simulated body fluid (SBF) was explored through XRD, Fourier transform infrared (FTIR) and Scanning electron microscopy (SEM-EDX) analyses. In this report, we observed that hydroxyapatite formation for 5days of immersion time. Also observed that with increasing the immersion time up to 15days, higher amount of hydroxyapatite layer formation on the surface of glasses. The varying composition of zirconia in glass samples influences shown by XRD, FTIR studies. The present results indicate that, in-vitro bioactivity of glasses decreased with increasing zirconia incorporation.

  11. Influence of Cu doping in borosilicate bioactive glass and the properties of its derived scaffolds

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hui [School of Materials Science and Engineering, Tongji University, Shanghai 2001804 (China); Zhao, Shichang [Department of Orthopedic Surgery, Shanghai Sixth People' s Hospital, Shanghai Jiao Tong University, Shanghai 200233 (China); Xiao, Wei [Department of Materials Science and Engineering, and Center for Biomedical Science and Engineering, Missouri University of Science and Technology, Rolla, MO 65409-0340 (United States); Xue, Jingzhe [Department of Chemistry, Tongji University, Shanghai 200092 (China); Shen, Youqu [Department of Materials Science and Engineering, and Center for Biomedical Science and Engineering, Missouri University of Science and Technology, Rolla, MO 65409-0340 (United States); Zhou, Jie; Huang, Wenhai [School of Materials Science and Engineering, Tongji University, Shanghai 2001804 (China); Rahaman, Mohamed N. [Department of Materials Science and Engineering, and Center for Biomedical Science and Engineering, Missouri University of Science and Technology, Rolla, MO 65409-0340 (United States); Zhang, Changqing, E-mail: shzhangchangqing@163.com [Department of Orthopedic Surgery, Shanghai Sixth People' s Hospital, Shanghai Jiao Tong University, Shanghai 200233 (China); Wang, Deping, E-mail: wdpshk@tongji.edu.cn [School of Materials Science and Engineering, Tongji University, Shanghai 2001804 (China)

    2016-01-01

    Copper doped borosilicate glasses (BG–Cu) were studied by means of FT-IR, Raman, UV–vis and NMR spectroscopies to investigate the changes that appeared in the structure of borosilicate glass matrix by doping copper ions. Micro-fil and immunohistochemistry analysis were applied to study the angiogenesis of its derived scaffolds in vivo. Results indicated that the Cu ions significantly increased the B–O bond of BO{sub 4} groups at 980 cm{sup −1}, while they decrease that of BO{sub 2}O{sup −} groups at 1440–1470 cm{sup −1} as shown by Raman spectra. A negative shift was observed from {sup 11}B and {sup 29}Si NMR spectra. The {sup 11}B NMR spectra exhibited a clear transformation from BO{sub 3} into BO{sub 4} groups, caused by the agglutination effect of the Cu ions and the charge balance of the agglomerate in the glass network, leading to a more stable glass network and lower ions release rate in the degradation process. Furthermore, the BG–Cu scaffolds significantly enhanced blood vessel formation in rat calvarial defects at 8 weeks post-implantation. Generally, it suggested that the introduction of Cu into borosilicate glass endowed glass and its derived scaffolds with good properties, and the cooperation of Cu with bioactive glass may pave a new way for tissue engineering. - Highlights: • Agglutination effect of Cu{sup 2+} and charge balance of agglomerate lead to more stable glass. • Lower degradability and lower ions release were found in BG-Cu scaffolds. • Excellent angiogenesis and sustain Cu{sup 2+} release were endowed by doping Cu.

  12. Laser Induced Damage Studies in Borosilicate Glass Using nanosecond and sub nanosecond pulses

    CERN Document Server

    Rastogi, Vinay; Munda, D S

    2016-01-01

    The damage mechanism induced by laser pulse of different duration in borosilicate glass widely used for making confinement geometry targets which are important for laser driven shock multiplication and elongation of pressure pulse, is studied. We measured the front and rear surface damage threshold of borosilicate glass and their dependency on laser parameters. In this paper, we also study the thermal effects on the damage diameters, generated at the time of plasma formation. These induced damage width, geometries and microstructure changes are measured and analyzed with optical microscope, scanning electron microscope and Raman spectroscopy. The results show that at low energies symmetrical damages are found and these damage width increases nonlinearly with laser intensity. The emitted optical spectrum during the process of breakdown is also investigated and is used for the characterization of emitted plasma such as plasma temperature and free electron density. Optical emission lines from Si I at 500 nm, Si ...

  13. IR study of Pb–Sr titanate borosilicate glasses

    Indian Academy of Sciences (India)

    C R Gautam; Devendra Kumar; Om Parkash

    2010-04-01

    The infrared spectra (IR) of various glass compositions in the glass system, [(PbSr1–)O.TiO2]– [2SiO2.B2O3]–[BaO.K2O]–[La2O3], were recorded over a continuous spectral range (400–4000 cm-1) to study their structure systematically. IR spectrum of each glass composition shows a number of absorption bands. These bands are strongly influenced by the increasing substitution of SrO for PbO. Various bands shift with composition. Absorption peaks occur due to the vibrational mode of the borate network in these glasses. The vibrational modes of the borate network are seen to be mainly due to the asymmetric stretching relaxation of the B–O bond of trigonal BO3 units. More splitting is observed in strontium-rich composition.

  14. Reaction of chromalumozirconium refractory with alkali-free borosilicate glass melt

    Energy Technology Data Exchange (ETDEWEB)

    Popov, O.N.; Frolova, V.P.

    1985-03-01

    The corrosion mechanism of chromalumozirconium refractory synthesized on the base of the Cr/sub 2/O/sub 3/-Al/sub 2/O/sub 3/-ZrO/sub 2/-SiO/sub 2/ system by the alkali-free borosilicate ''E'' glass melt is investigated. It is estalished that in the process of refractory destruction the diffusion zonality is formed in it being a reflection of comparative migration activity of refractory components.

  15. Er3+–Al2O3 nanoparticles doping of borosilicate glass

    Indian Academy of Sciences (India)

    Jonathan Massera; Laeticia Petit; Joona Koponen; Benoit Glorieux; Leena Hupa; Mikko Hupa

    2015-09-01

    Novel borosilicate glasses were developed by adding in the glass batch Er3+–Al2O3 nanoparticles synthetized by using a soft chemical method. A similar nanoparticle doping with modified chemical vapour deposition (MCVD) process was developed to increase the efficiency of the amplifying silica fibre in comparison to using MCVD and solution doping. It was shown that with the melt quench technique, a Er3+–Al22O3 nanoparticle doping neither leads to an increase in the Er3+ luminescence properties nor allows one to control the rare-earth chemical environment in a borosilicate glass. The site of Er3+ in the Er3+–Al2O3 nanoparticle containing glass seems to be similar as in glasses with the same composition prepared using standard raw materials. We suspect the Er3+ ions to diffuse from the nanoparticles into the glass matrix. There was no clear evidence of the presence of Al2O3 nanoparticles in the glasses after melting.

  16. Rhenium solubility in borosilicate nuclear waste glass: implications for the processing and immobilization of technetium-99.

    Science.gov (United States)

    McCloy, John S; Riley, Brian J; Goel, Ashutosh; Liezers, Martin; Schweiger, Michael J; Rodriguez, Carmen P; Hrma, Pavel; Kim, Dong-Sang; Lukens, Wayne W; Kruger, Albert A

    2012-11-20

    The immobilization of technetium-99 ((99)Tc) in a suitable host matrix has proven to be a challenging task for researchers in the nuclear waste community around the world. In this context, the present work reports on the solubility and retention of rhenium, a nonradioactive surrogate for (99)Tc, in a sodium borosilicate glass. Glasses containing target Re concentrations from 0 to 10,000 ppm [by mass, added as KReO(4) (Re(7+))] were synthesized in vacuum-sealed quartz ampules to minimize the loss of Re from volatilization during melting at 1000 °C. The rhenium was found as Re(7+) in all of the glasses as observed by X-ray absorption near-edge structure. The solubility of Re in borosilicate glasses was determined to be ~3000 ppm (by mass) using inductively coupled plasma optical emission spectroscopy. At higher rhenium concentrations, additional rhenium was retained in the glasses as crystalline inclusions of alkali perrhenates detected with X-ray diffraction. Since (99)Tc concentrations in a glass waste form are predicted to be wastes, assuming Tc as Tc(7+) and similarities between Re(7+) and Tc(7+) behavior in this glass system.

  17. Internal modification of poly(dimethylsiloxane) microchannels with a borosilicate glass coating.

    Science.gov (United States)

    Orhan, J-B; Parashar, V K; Flueckiger, J; Gijs, M A M

    2008-08-19

    We report on an original technique for the in situ coating of poly(dimethylsiloxane) (PDMS) microchannels with borosilicate glass, starting from an active nonaqueous and alkali-free precursor solution. By chemical reaction of this active solution inside the microchannel and subsequent thermal annealing, a protective and chemically inert glass borosilicate coating is bonded to the PDMS. Attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy and nuclear magnetic resonance spectroscopy of the active solution show that it is composed of a silicon oxide network with boron connectivity. Thermal gravimetric analysis demonstrates the absence of organic content when curing is done above 150 degrees C. The borosilicate nature of the glass coating covalently bonded to the PDMS is demonstrated using ATR-FTIR spectroscopy and X-ray photoelectron spectroscopy. Atomic force microscopy and scanning electron microscopy show a smooth and crack-free coating. The latter is used as an efficient protective barrier against diffusion in PDMS of fluorescent rhodamine B dye that is dissolved either in water or in toluene. Moreover, the coating prevents swelling and consequent structural damage of the PDMS when the latter is exposed to harsh chemicals such as toluene.

  18. Reactions of chromium-aluminum-zirconium refractory with a molten alkali-free borosilicate glass

    Energy Technology Data Exchange (ETDEWEB)

    Popov, O.N.; Frolova, V.P.

    1985-08-01

    The authors consider the scope for using KhTs-45 refractory containing in mass % 45.0 Cr2O3, 5.0 Al2O3, 32.5 ZrO2, 16.0 SiO2, and 1.5 Na2O for melting alkali-free borosilicate glass E, and they also present some experimental results on the corrosion of the refractory in contact with the molten glass and on the contact mineral formation. They conclude that during the attack on the refractory diffusion zoning is formed, which reflects the relative component migration activities.

  19. Structural investigations of bismuth lead borosilicate glasses under the influence of gamma irradiation through ultrasonic studies

    Science.gov (United States)

    Bootjomchai, Cherdsak; Laopaiboon, Jintana; Laopaiboon, Raewat

    2012-04-01

    The ultrasonic velocity measurements for different compositions of irradiated bismuth lead borosilicate glasses xBi2O3-(50-x)PbO-20B2O3-30SiO2 (x=2, 4, 6, 8, and 10 mol.%) were performed at room temperature using pulse-echo technique. Densities of glass samples were measured by Archimedes' principle using n-hexane as the immersion liquid. The results from the studies show that ultrasonic velocity, elastic moduli, Poisson's ratio, microhardness, and the Debye temperature increase with increasing bismuth oxide content and increasing gamma-radiation dose (3-12 Gy).

  20. Simulation of cooling and solidification of three-dimensional bulk borosilicate glass: effect of structural relaxations

    Science.gov (United States)

    Barth, N.; George, D.; Ahzi, S.; Rémond, Y.; Joulaee, N.; Khaleel, M. A.; Bouyer, F.

    2014-02-01

    The modeling of the viscoelastic stress evolution and specific volume relaxation of a bulky glass cast is presented in this article and is applied to the experimental cooling process of an inactive nuclear waste vitrification process. The concerned borosilicate glass is solidified and cooled down to ambient temperature in a stainless steel canister, and the thermomechanical response of the package is simulated. There exists a deviant compression of the liquid core due to the large glass package compared to standard tempered glass plates. The stress load development of the glass cast is finally studied for different thermal load scenarios, where the cooling process parameters or the final cooldown rates were changed, and we found a great influence of the studied cooldown rates on the maximum stress build-up at ambient temperature.

  1. Laser ablation of borosilicate glass with high power shaped UV nanosecond laser pulses

    Science.gov (United States)

    von Witzendorff, Philipp; Bordin, Andrea; Suttmann, Oliver; Patel, Rajesh S.; Bovatsek, James; Overmeyer, Ludger

    2016-03-01

    The application of thin borosilicate glass as interposer material requires methods for separation and drilling of this material. Laser processing with short and ultra-short laser pulses have proven to enable high quality cuts by either direct ablation or internal glass modification and cleavage. A recently developed high power UV nanosecond laser source allows for pulse shaping of individual laser pulses. Thus, the pulse duration, pulse bursts and the repetition rate can be set individually at a maximum output power of up to 60 W. This opens a completely new process window, which could not be entered with conventional Q-switched pulsed laser sources. In this study, the novel pulsed UV laser system was used to study the laser ablation process on 400 μm thin borosilicate glass at different pulse durations ranging from 2 - 10 ns and a pulse burst with two 10 ns laser pulses with a separation of 10 ns. Single line scan experiments were performed to correlate the process parameters and the laser pulse shape with the ablation depth and cutting edge chipping. Increasing the pulse duration within the single pulse experiments from 2 ns to longer pulse durations led to a moderate increase in ablation depth and a significant increase in chipping. The highest material removal was achieved with the 2x10 ns pulse burst. Experimental data also suggest that chipping could be reduced, while maintaining a high ablation depth by selecting an adequate pulse overlap. We also demonstrate that real-time combination of different pulse patterns during drilling a thin borosilicate glass produced holes with low overall chipping at a high throughput rate.

  2. Structural, linear and third-order nonlinear optical properties of Cu nanocrystal in sodium borosilicate glass

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Jiasong [College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035 (China); College of Materials Science and Engineering, Tongji University, Shanghai 201804 (China); Xiang, Weidong, E-mail: xiangweidong001@126.com [College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035 (China); College of Materials Science and Engineering, Tongji University, Shanghai 201804 (China); Chen, Zhaoping; Zhao, Haijun; Liang, Xiaojuan [College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035 (China)

    2013-09-01

    Highlights: • The NBS glass containing different Cu concentrations were prepared by sol–gel method. • High dispersion and narrow distribution of Cu nanocrystals were in the form of glass. • The optical absorption spectra exhibited the typical SPR for Cu in the wavelength range of 550–600 nm. • The third-order optical properties were investigated by Z-scan technique. -- Abstract: Cu nanocrystals embedded in sodium borosilicate glass of varied Cu contents from 0.5 to 1.5 wt% have been successfully prepared through a sol–gel process. According to the results of X-ray diffraction (XRD) and the energy dispersive X-ray spectrometry (EDS), the metal Cu nanocrystals in cubic crystal system were well distributed inside glass matrix. Fourier Transform Infrared (FTIR) indicated the sodium borosilicate matrix had no major structural change for gels with different Cu contents. The optical absorption peaks due to the surface plasmon resonance of Cu particles were observed in the wavelength range of 550–600 nm. The absorption peak showed a red-shift trend with increasing Cu contents from 0.5 to 1.5 wt%. Transmission electron microscopy (TEM) revealed the existence of spherical Cu nanocrystals in the matrix. The diameter of Cu nanocrystals varied from 1 to 3.5 nm. Furthermore, the third-order nonlinear optical properties were investigated by Z-scan technique at 800 nm. Experimental results indicated the Cu nanocrystals have obvious positive refractive nonlinearities and reverse saturated absorption performance.

  3. The effect of melt infiltration of borosilicate glass on biaxial flexural strength of porcelain-veneered zirconia

    Science.gov (United States)

    Joo, Kyu Ji; Song, Kyung Woo; Jung, Jong Hyun; Ahn, Hyo Jin; Park, Il Song; Lee, Min Ho; Bae, Tae Sung

    2011-08-01

    To evaluate the effect of melt infiltration on the biaxial flexural strength of porcelain-bonded zirconia, borosilicate glasses were used in this study. Presintered yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) blocks were milled and used for disc specimens. Prior to veneering of porcelain, the infiltration of borosilicate glass on zirconia was performed at 1,100 °C for 1 h. After a biaxial flexural test with the crosshead speed of 0.1 mm/min, fractured surfaces and interfaces between zirconia and veneer porcelain were observed with a Scanning Electron Microscope (SEM). The fracture strength of sintered zirconia and veneer porcelain was significantly increased by the melt infiltration of borosilicate glass (P porcelain increased slightly. The sintered zirconia group showed a smooth fracture surface containing many pores, but the glass-infiltrated zirconia group showed a rough fracture surface.

  4. Preparation and luminescence properties of Eu3+ doped oxyfluoride borosilicate glass ceramics

    Institute of Scientific and Technical Information of China (English)

    LI Yanhong; ZHAO Li; ZHANG Yongming; MA Jing

    2012-01-01

    Oxyfluoride borosilicate glass with the molar composition of60SiO2-15B2O3-15Na2O-8CaF2-2NaF-0.25Eu2O3 was synthesized by a traditional glass melting method.Glass ceramics containing CaF2 nanocrystals were preparcd by heat treating the glass samples at a temperature in the range of 620-680℃.The results of X-ray diffraction (XRD) indicated that the average crystallite size and the lattice constant of CaF2 nanocrystals increased with the heat treatment temperature incrcasing.The luminescence spectra showed that the emission intensity of Eu3+ doped glass ceramics was stronger than that of the glass matrix,and increased with the heat treatment temperature increasing.The left edge of excitation band shifted to shorter wavelength in the glass ceramics.The local environments of Eu3+ ions in the glass and glass ceramics were different.

  5. Leach behavior of high-level borosilicate glasses under deep geological environment

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seung Soo; Chun, Kwan Sik; Park, Hyun Soo

    1998-02-01

    This report presents an overview of the activities in high-level radioactive waste glass which is considered as the most practicable form of waste, and also is intended to be used in the disposal of national high-level radioactive waste in future. Leach theory of waste glass and the leach effects of ground water, metal barrier, buffer materials and rocks on the waste glass were reviewed. The leach of waste glass was affected by various factors such as composition, pH and Eh of ground water, temperature, pressure, radiation and humic acid. The crystallization, crack, weathering and the formation of altered phases of waste glass which is expected to occur in real disposal site were reviewed. The results of leaching in laboratory and in-situ were compared. The behaviors of radioactive elements leached from waste glass and the use of basalt glass for the long-term natural analogue of waste glass were also written in this report. The appraisal of durability of borosilicate waste glass as a waste media was performed from the known results of leach test and international in-situ tests were introduced. (author). 134 refs., 15 tabs., 24 figs

  6. Synthesis, Structural and Optical Investigations of (Pb, BiTiO3 Borosilicate Glasses

    Directory of Open Access Journals (Sweden)

    Chandkiram Gautam

    2014-01-01

    Full Text Available A new series of lead bismuth titanate borosilicate glasses with addition of one percent lanthanum oxide have been synthesized using melt-quench technique. X-ray diffraction patterns have been recorded to confirm the amorphous nature of the prepared glass samples. The synthesized glasses have been characterized by using various spectroscopic techniques such as UV-visible, infrared, and Raman spectroscopy. UV-visible measurements were recorded in the wavelength range from 200 to 1100 nm whereas IR and Raman spectroscopic measurements were recorded over a continuous wavenumber range from 400 to 5000 cm−1 and 1000 to 2000 cm−1 respectively. The different absorption peaks/bands were formed in IR spectral patterns. The spectral bands appear towards the lower wavenumber sides due to the Bi and Pb, content while the bands appear towards the higher wavenumber sides due to the formation of diborate and triborate network units.

  7. Water leaching of borosilicate glasses: experiments, modeling and Monte Carlo simulations; Alteration par l'eau des verres borosilicates: experiences, modelisation et simulations Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Ledieu, A

    2004-10-15

    This work is concerned with the corrosion of borosilicate glasses with variable oxide contents. The originality of this study is the complementary use of experiments and numerical simulations. This study is expected to contribute to a better understanding of the corrosion of nuclear waste confinement glasses. First, the corrosion of glasses containing only silicon, boron and sodium oxides has been studied. The kinetics of leaching show that the rate of leaching and the final degree of corrosion sharply depend on the boron content through a percolation mechanism. For some glass contents and some conditions of leaching, the layer which appears at the glass surface stops the release of soluble species (boron and sodium). This altered layer (also called the gel layer) has been characterized with nuclear magnetic resonance (NMR) and small angle X-ray scattering (SAXS) techniques. Second, additional elements have been included in the glass composition. It appears that calcium, zirconium or aluminum oxides strongly modify the final degree of corrosion so that the percolation properties of the boron sub-network is no more a sufficient explanation to account for the behavior of these glasses. Meanwhile, we have developed a theoretical model, based on the dissolution and the reprecipitation of the silicon. Kinetic Monte Carlo simulations have been used in order to test several concepts such as the boron percolation, the local reactivity of weakly soluble elements and the restructuring of the gel layer. This model has been fully validated by comparison with the results on the three oxide glasses. Then, it has been used as a comprehensive tool to investigate the paradoxical behavior of the aluminum and zirconium glasses: although these elements slow down the corrosion kinetics, they lead to a deeper final degree of corrosion. The main contribution of this work is that the final degree of corrosion of borosilicate glasses results from the competition of two opposite mechanisms

  8. Aqueous corrosion of borosilicate glasses: experiments, modeling and Monte-Carlo simulations; Alteration par l'eau des verres borosilicates: experiences, modelisation et simulations Monte-Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Ledieu, A

    2004-10-01

    This work is concerned with the corrosion of borosilicate glasses with variable oxide contents. The originality of this study is the complementary use of experiments and numerical simulations. This study is expected to contribute to a better understanding of the corrosion of nuclear waste confinement glasses. First, the corrosion of glasses containing only silicon, boron and sodium oxides has been studied. The kinetics of leaching show that the rate of leaching and the final degree of corrosion sharply depend on the boron content through a percolation mechanism. For some glass contents and some conditions of leaching, the layer which appears at the glass surface stops the release of soluble species (boron and sodium). This altered layer (also called the gel layer) has been characterized with nuclear magnetic resonance (NMR) and small angle X-ray scattering (SAXS) techniques. Second, additional elements have been included in the glass composition. It appears that calcium, zirconium or aluminum oxides strongly modify the final degree of corrosion so that the percolation properties of the boron sub-network is no more a sufficient explanation to account for the behavior of these glasses. Meanwhile, we have developed a theoretical model, based on the dissolution and the reprecipitation of the silicon. Kinetic Monte Carlo simulations have been used in order to test several concepts such as the boron percolation, the local reactivity of weakly soluble elements and the restructuring of the gel layer. This model has been fully validated by comparison with the results on the three oxide glasses. Then, it has been used as a comprehensive tool to investigate the paradoxical behavior of the aluminum and zirconium glasses: although these elements slow down the corrosion kinetics, they lead to a deeper final degree of corrosion. The main contribution of this work is that the final degree of corrosion of borosilicate glasses results from the competition of two opposite mechanisms

  9. Deformation mechanisms during nanoindentation of sodium borosilicate glasses of nuclear interest.

    Science.gov (United States)

    Kilymis, D A; Delaye, J-M

    2014-07-07

    In this paper we analyze results of Molecular Dynamics simulations of Vickers nanoindentation, performed for sodium borosilicate glasses of interest in the nuclear industry. Three glasses have been studied in their pristine form, as well as a disordered one that is analogous to the real irradiated glass. We focused in the behavior of the glass during the nanoindentation in order to reveal the mechanisms of deformation and how they are affected by microstructural characteristics. Results have shown a strong dependence on the SiO2 content of the glass, which promotes densification due to the open structure of SiO4 tetrahedra and also due to the strength of Si-O bonds. Densification for the glasses is primarily expressed by the relative decrease of the Si-O-Si and Si-O-B angles, indicating rotation of the structural units and decrease of free volume. The increase of alkali content on the other hand results to higher plasticity of the matrix and increased shear flow. The most important effect on the deformation mechanism of the disordered glasses is that of the highly depolymerized network that will also induce shear flow and, in combination with the increased free volume, will result in the decreased hardness of these glasses, as has been previously observed.

  10. Investigation of gamma radiation induced changes in local structure of borosilicate glass by TDPAC and EXAFS

    Science.gov (United States)

    Kumar, Ashwani; Nayak, C.; Rajput, P.; Mishra, R. K.; Bhattacharyya, D.; Kaushik, C. P.; Tomar, B. S.

    2016-12-01

    Gamma radiation induced changes in local structure around the probe atom (Hafnium) were investigated in sodium barium borosilicate (NBS) glass, used for immobilization of high level liquid waste generated from the reprocessing plant at Trombay, Mumbai. The (NBS) glass was doped with 181Hf as a probe for time differential perturbed angular correlation (TDPAC) spectroscopy studies, while for studies using extended X-ray absorption fine structure (EXAFS) spectroscopy, the same was doped with 0.5 and 2 % (mole %) hafnium oxide. The irradiated as well as un-irradiated glass samples were studied by TDPAC and EXAFS techniques to obtain information about the changes (if any) around the probe atom due to gamma irradiation. TDPAC spectra of unirradiated and irradiated glasses were similar and reminescent of amorphous materials, indicating negligible effect of gamma radiation on the microstructure around Hafnium probe atom, though the quaqdrupole interaction frequency ( ω Q) and asymmetry parameter ( η) did show a marginal decrease in the irradiated glass compared to that in the unirradiated glass. EXAFS measurements showed a slight decrease in the Hf-O bond distance upon gamma irradiation of Hf doped NBS glass indicating densification of the glass matrix, while the cordination number around hafnium remains unchanged.

  11. Preparation and Optical Properties of Er3+ -Doped Gadolinium Borosilicate Glasses

    Institute of Scientific and Technical Information of China (English)

    Sun Jiangting; Zhang Jiahua; Chen Baojiu; Lu Shaozhe; Ren Xinguang; Wang Xiaojun

    2005-01-01

    Er3+-doped Gd2 O3 -SiO2 -B2 O3 -Na2O glasses were prepared, and formation range of glass of Gd2 O3 -SiO2 -B2O3 system was experimentally obtained. It is found that the glass phase can be formed only when the content of SiO2 is 0~50%(molar fraction), Gd2O3 is 0~30%(molar fraction) and B2 O3 is above 20%(molar fraction) in this glass system. The glass can also be obtained but becomes translucent at the contents of 60%(molar fraction) SiO2 and 30% Gd2O3 , or at the contents of 60%(molar fraction) SiO2 and 30%(molar fraction) B2O3. There is no glass phase formed in other glass components. Glass forming ability for Gd2O3 content of 10%, was characterized by the value of β, the parameter of crystallization tendency, which is 0.32~1.76, obtained from the differential thermal analysis. The absorption and emission cross section, the J-O parameters Ωt(2,4,6) and radiative transition probabilities were calculated by using the theory of McCumber and Judd-Ofelt. The emission properties at 1.5 μm of the samples are discussed with the product of full width at half maximum and stimulated emission cross section. It can be seen that the value of the FWHM×σepeak product in the prepared glass is more than those of germanate, silicate and phosphate glasses. Furthermore, the maximum value of the product among these glasses reported in this work is close to that of oxyfluoride silicate glass. Therefore, the Er3+-doped gadolinium borosilicate glass in this paper is a candidate for broadband erbium doped fiber amplifiers.

  12. EVALUATION OF IMPURITY EXTREMES IN A PLUTONIUM-LOADED BOROSILICATE GLASS

    Energy Technology Data Exchange (ETDEWEB)

    Marra, J; Kevin Fox, K; Charles Crawford, C; Ned Bibler, N; Elizabeth Hoffman, E; Tommy Edwards, T

    2007-11-12

    A vitrification technology utilizing a lanthanide borosilicate (LaBS) glass appears to be a viable option for the disposition of excess weapons-useable plutonium that is not suitable for processing into mixed oxide (MOX) fuel. A significant effort to develop a glass formulation and vitrification process to immobilize plutonium was completed in the mid-1990s. The LaBS glass formulation was found to be capable of immobilizing in excess of 10 wt % Pu and to be tolerant of a range of impurities. To confirm the results of previous testing with surrogate Pu feeds containing impurities, four glass compositions were selected for fabrication with actual plutonium oxide and impurities. The four compositions represented extremes in impurity type and concentration. The homogeneity and durability of these four compositions were measured. The homogeneity of the glasses was evaluated using x-ray diffraction (XRD) and scanning electron microscopy coupled with energy dispersive spectroscopy (SEM/EDS). The XRD results indicated that the glasses were amorphous with no evidence of crystalline species in the glass. The SEM/EDS analyses did show the presence of some undissolved PuO{sub 2} material. The EDS spectra indicated that some of the PuO{sub 2} crystals also contained hafnium oxide. The SEM/EDS analyses showed that there were no heterogeneities in the glass due to the feed impurities. The durability of the glasses was measured using the Product Consistency Test (PCT). The PCT results indicated that the durability of Pu impurity glasses was comparable with Pu glasses without impurities and significantly more durable than the Environmental Assessment (EA) glass used as the benchmark for repository disposition of high-level waste (HLW) glasses.

  13. High-level waste borosilicate glass: A compendium of corrosion characteristics. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Cunnane, J.C. [comp.; Bates, J.K.; Bradley, C.R. [Argonne National Lab., IL (United States)] [and others

    1994-03-01

    The objective of this document is to summarize scientific information pertinent to evaluating the extent to which high-level waste borosilicate glass corrosion and the associated radionuclide release processes are understood for the range of environmental conditions to which waste glass may be exposed in service. Alteration processes occurring within the bulk of the glass (e.g., devitrification and radiation-induced changes) are discussed insofar as they affect glass corrosion.This document is organized into three volumes. Volumes I and II represent a tiered set of information intended for somewhat different audiences. Volume I is intended to provide an overview of waste glass corrosion, and Volume 11 is intended to provide additional experimental details on experimental factors that influence waste glass corrosion. Volume III contains a bibliography of glass corrosion studies, including studies that are not cited in Volumes I and II. Volume I is intended for managers, decision makers, and modelers, the combined set of Volumes I, II, and III is intended for scientists and engineers working in the field of high-level waste.

  14. Pyrolysis of arylglycol-[beta]-propylphenyl ether lignin model in the presence of borosilicate glass fibers

    Energy Technology Data Exchange (ETDEWEB)

    Kuroda, Ken-ichi (Institute of Agricultural and Forest Engineering, University of Tsukuba, Ibaraki (Japan))

    1994-12-01

    Two [beta]-aryl ether type model compounds, guaiacylglycol- and veratrylglycol-[beta]-propyl-phenyl ethers, were copyrolyzed with borosilicate glass fibers. The results provided a better understanding of the effect of copyrolysis with the fibers on the yields of lignin-derived products from lignocellulosics.The observed products indicated the following reactions occurring in the models; (1) cleavage of the C[alpha]-aromatic ring bond, (2) cleavage of the [beta]-ether bond, (3) cleavage of the C[alpha]-C[beta] bond, (4) [alpha],[beta]-dehydration, and (5) demethylation, and others. Of these reactions, reactions (1), (2) and (4) were the main pyrolysis reactions and fully explained the increase in the total yield of lignin-derived pyrolysis products from Japanese red pine (Pinus densiflora Sieb. et Zucc.) in the presence of borosilicate glass fibers. Reaction (1) was a particularly characteristic reaction in copyrolysis with the fibers. Important reactions relating to the increase in the total yield of lignin-derived pyrolysis products were reproduced on the models used

  15. Intrinsic dosimetry. Properties and mechanisms of thermoluminescence in commercial borosilicate glass

    Energy Technology Data Exchange (ETDEWEB)

    Clark, Richard A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2012-10-01

    Intrinsic dosimetry is the method of measuring total absorbed dose received by the walls of a container holding radioactive material. By considering the total absorbed dose received by a container in tandem with the physical characteristics of the radioactive material housed within that container, this method has the potential to provide enhanced pathway information regarding the history of the container and its radioactive contents. The latest in a series of experiments designed to validate and demonstrate this newly developed tool are reported. Thermoluminescence (TL) dosimetry was used to measure dose effects on raw stock borosilicate container glass up to 70 days after gamma ray, x-ray, beta particle or ultraviolet irradiations at doses from 0.15 to 20 Gy. The TL glow curve when irradiated with 60Co was separated into five peaks: two relatively unstable peaks centered near 120 and 165°C, and three relatively stable peaks centered near 225, 285, and 360°C. Depending on the borosilicate glass source, the minimum measurable dose using this technique is 0.15-0.5 Gy, which is roughly equivalent to a 24 hr irradiation at 1 cm from a 50-165 ng source of 60Co. Differences in TL glow curve shape and intensity were observed for the glasses from different geographical origins. These differences can be explained by changes in the intensities of the five peaks. Electron paramagnetic resonance (EPR) and multivariate statistical methods were used to relate the TL intensity and peaks to electron/hole traps and compositional variations.

  16. In vitro bioactivity and cytocompatibility of porous scaffolds of bioactive borosilicate glasses

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xin; FU HaiLuo; LIU Xin; YAO AiHua; WANG DePing; HUANG WenHai; ZHAO Ying; JIANG XinQuan

    2009-01-01

    The bioactive borosilicate scaffolds (R2O-RO-B2O3-SiO2-P2O5) with four different contents of borate were fabricated by replication technique. The bioactivity,degradability and the cytotoxicity of the scaffolds were studied in this paper. The porosity of the scaffolds was found to be 73%-80%,and the pore size was in the range of 200-300 μm. The porous scaffolds immersed in 0.02 mol. L-1 K2HPO4 solution were transformed into hydroxyapatite. And it is notable that the D-AIk-2B,D-AIk-3B-scaffolds were covered by hydroxyapatite layers after 7 h-immersion,which proved their high bioactivity. In the cell adhesion test,cells could be seen growing well on the scaffolds,showing stretched morphology and obvious pseudopodia,and only the high cumulative concentration of B ions released from the D-AIk-3B-scaffold samples had an inhibition effect on cell proliferation. But the inhibition effect could be alleviated by diluting the extract solution to a certain concentration (dilution ratio:1:8). Therefore,after suitable pretreatment,the porous borosilicate bioactive glass scaffold can be e desirable candidate for bone tissue engineering.

  17. An alkali-free barium borosilicate viscous sealing glass for solid oxide fuel cells

    Science.gov (United States)

    Hsu, Jen-Hsien; Kim, Cheol-Woon; Brow, Richard K.; Szabo, Joe; Crouch, Ray; Baird, Rob

    2014-12-01

    An alkali-free, alkaline earth borosilicate glass (designated G102) has been developed as a viscous sealant for use with solid oxide fuel cells (SOFCs). The glass possesses the requisite viscosity, electrical resistivity, and thermal and chemical stability under SOFC operating conditions to act as a reliable sealant. Sandwich seals between aluminized stainless steel and a YSZ/NiO-YSZ bilayer survived 148 thermal cycles (800 °C to room temperature) in both oxidizing and reducing atmospheres at a differential pressure of ∼3.4 kPa (0.5 psi) without failure. For sandwich seals that were held at 800 °C for up to 2280 h in air, G102 resisted crystallization, there were limited interactions at the G102/YSZ interface, but BaAl2Si2O8 crystals formed at the glass/metal interface because of the reaction between the glass and the aluminized steel. Sandwich seals that were intentionally cracked by thermal shock resealed to became hermetic upon reheating to temperatures as low as 744 °C.

  18. Evolutions of Molecular Oxygen Formation and Sodium Migration in Xe Ion Irradiated Borosilicate Glasses

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Liang; Zhang, Duofei F.; Lv, Peng; Zhang, Jiandong; Du, Xing; Yuan, Wei; Nan, Shuai; Zhu, Zihua; Wang, Tieshan

    2016-07-23

    The modifications of a commercial borosilicate glass induced by Xe ion irradiation have been studied by Raman spectroscopy and ToF-SIMS depth profiling. A decrease in the average Si–O–Si angle, an increase in the population of three-membered rings and an increase of the glass polymerization are evidenced. The molecular oxygen appears in the irradiated glasses after the irradiation fluence reaches approximately 1015 ions/cm2. The O2 concentration decreaseswith the depth of irradiated glass at the ion fluence of 2 × 1016 ions/cm2. A sodiumdepleted layer at the surface and a depleted zone at around the penetration depth of 5 MeV Xe ions are observed. The thickness of the sodium depleted layer increases with the irradiation fluence. Moreover, comparing with previous results after electron and Ar ion irradiation, it can be concluded that the nuclear energy deposition can partially inhibit the formation of molecular oxygen and increase the threshold value of electron energy deposition for the molecular oxygen formation.

  19. Mechanism of RuO2 crystallization in borosilicate glass: an original in situ ESEM approach.

    Science.gov (United States)

    Boucetta, Hassiba; Podor, Renaud; Stievano, Lorenzo; Ravaux, Johann; Carrier, Xavier; Casale, Sandra; Gossé, Stéphane; Monteiro, Amélie; Schuller, Sophie

    2012-03-19

    Ruthenium, a fission product arising from the reprocessing of spent uranium oxide (UOX) fuel, crystallizes in the form of acicular RuO(2) particles in high-level waste containment glass matrices. These particles are responsible for significant modifications in the physicochemical behavior of the glass in the liquid state, and their formation mechanisms are a subject of investigation. The chemical reactions responsible for the crystallization of RuO(2) particles with acicular or polyhedral shape in simplified radioactive waste containment glass are described. In situ high-temperature environmental scanning electron microscopy (ESEM) is used to follow changes in morphology and composition of the ruthenium compounds formed by reactions at high temperature between a simplified RuO(2)-NaNO(3) precursor and a sodium borosilicate glass (SiO(2)-B(2)O(3)-Na(2)O). The key parameter in the formation of acicular or polyhedral RuO(2) crystals is the chemistry of the ruthenium compound under oxidized conditions (Ru(IV), Ru(V)). The precipitation of needle-shaped RuO(2) crystals in the melt might be associated with the formation of an intermediate Ru compound (Na(3)Ru(V)O(4)) before dissolution in the melt, allowing Ru concentration gradients. The formation of polyhedral crystals is the result of the direct incorporation of RuO(2) crystals in the melt followed by an Ostwald ripening mechanism.

  20. Evaluation of gamma-ray exposure buildup factors and neutron shielding for bismuth borosilicate glasses

    Science.gov (United States)

    Singh, Vishwanath P.; Badiger, N. M.; Chanthima, N.; Kaewkhao, J.

    2014-05-01

    Gamma-ray exposure buildup factor (EBF) values and neutron shielding effectiveness of bismuth borosilicate (BBS) glass systems in composition (50-x)SiO2:15B2O3:2Al2O3:10CaO:23Na2O:xBi2O3 (where x=0, 5, 10, 15 and 20 mol%) were calculated. The EBF values were computed for photon energy 0.015-15 MeV up to penetration depths of 40 mfp (mean free path) by the geometrical progression (G-P) method. The EBF values were found dependent upon incident photon energy, penetration and bismuth molar concentration. In low- and high-energy photon regions, the EBF values were minimum whereas maximum in the intermediate-energy region. The fast neutron removal cross sections for energy 2-12 MeV were calculated by the partial density method. The BBS glass with 20 mol% Bi2O3 is found to be superior gamma-ray and neutron transparent shielding. The EBF values of the BBS glasses were compared with steel-magnetite concrete and lead. The investigation was carried out to explore the advantages of the BBS glasses in different radiation shielding applications.

  1. Preparation and optical properties of sodium borosilicate glasses containing Sb nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Jiasong, E-mail: jiasongzhong@hdu.edu.cn [College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China); Ma, Xin [College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035 (China); Lu, Hongwei; Wang, Xin; Zhang, Suling [College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China); Xiang, Weidong, E-mail: xiangweidong001@126.com [College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035 (China)

    2014-09-01

    Highlights: • The Sb nanoparticles doped in Na{sub 2}O–B{sub 2}O{sub 3}–SiO{sub 2} glass were prepared by sol–gel methods. • Obtained glass was investigated by structural and optical measurements. • The glass was crystalline with a rhombohedral structure of Sb. • An absorption peak centered on 566 nm has been observed in doping glass. • The third-order optical nonlinearity was investigated by femtosecond Z-scan technique. - Abstract: Sb nanoparticles have been successfully prepared from SbCl{sub 3} in sodium borosilicate (Na{sub 2}O–B{sub 2}O{sub 3}–SiO{sub 2}) glass matrix by sol–gel method, involving metallic sodium as sodium source, boric acid as boron source and SiO{sub 2} come from hydrolysis of tetraethoxysilane. The feasibility of process conditions were analyzed by using Fourier Transform Infrared (FT-IR), thermal gravimetric (TG), and nuclear magnetic resonance (NMR). X-ray diffraction (XRD) study revealed that the rhombohedral structure of metal Sb have formed in the glass. The particle was found to be spherical shaped and highly monodispersed with an average size of about 32.63 nm as analyzed from transmission electron microscopy (TEM). The surface plasmon resonance (SPR) of Sb nanoparticle was studied from the UV–Vis absorption. The nonlinear optical properties were studied by using the Z-scan technique with a Ti:sapphire laser at 800 nm. Results showed that the third-order optical nonlinear susceptibility χ{sup (3)} of the glass was determined to be 4.85 × 10{sup −11} esu.

  2. Suppression of surface crystallization on borosilicate glass using RF plasma treatment

    Science.gov (United States)

    Yoo, Sunghyun; Ji, Chang-Hyeon; Jin, Joo-Young; Kim, Yong-Kweon

    2014-10-01

    Surface crystallization on a commercial grade borosilicate glass wafer, Borofloat® 33, is effectively prevented against 3 h of thermal reflow process at 850 °C. Surface plasma treatment with three different reactive gases, CF4, SF6, and Cl2, has been performed prior to the annealing. The effect of plasma treatment on surface ion concentration and nucleation of cristobalite were examined through optical microscope and x-ray photoemission spectroscopy. The dominant cause that suppresses crystallization was verified to be the increase of surface ion concentration of alumina during the plasma treatment. Both CF4 and SF6 treatment of no less than 30 s showed significant efficacy in suppressing crystallization by a factor of more than 112. Average surface roughness and the optical transparency were also enhanced by a factor of 15 and 3, respectively, compared to untreated sample.

  3. Experimental and computed results investigating time-dependent failure in a borosilicate glass

    Science.gov (United States)

    Chocron, Sidney; Barnette, Darrel; Holmquist, Timothy; Anderson, Charles E.; Bigger, Rory; Moore, Thomas

    2017-01-01

    Symmetric plate-impact tests of borosilicate glass were performed from low (116 m/s) to higher (351 m/s) velocities. The tests were recorded with an ultra-high-speed camera to see the shock and failure propagation. The velocity of the back of the target was also recorded with a PDV (Photon Doppler Velocimeter). The images show failure nucleation sites that trail the shock wave. Interestingly, even though the failure wave is clearly seen, the PDV never detected the expected recompression wave. The reason might be that at these low impact velocities the recompression wave is too small to be seen and is lost in the noise. This work also presents a new way to interpret the signals from the PDV. By letting part of the signal travel through the target and reflect on the impact side, it is possible to see the PDV decrease in intensity with time, probably due to the damage growth behind the shock wave.

  4. Heat accumulation during high repetition rate ultrafast laser interaction: Waveguide writing in borosilicate glass

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Haibin; Eaton, Shane M; Li, Jianzhao; Herman, Peter R [The Edward S. Rogers Sr. Department of Electrical and Computer Engineering, University of Toronto, 10 King' s College Road, Toronto, ON, M5S 3G4 (Canada)

    2007-04-15

    During high repetition rate (>200 kHz) ultrafast laser waveguide writing, visible heat modified zones surrounding the formed waveguide occur as a result of heat accumulation. The radii of the heat-modified zones increase with the laser net fluence, and were found to correlate with the formation of low-loss and cylindrically symmetric optical waveguides. A numerical thermal model based on the finite difference method is applied here to account for cumulative heating and diffusion effects. The model successfully shows that heat propagation and accumulation accurately predict the radius of the 'heat modified' zones observed in borosilicate glass waveguides formed across a wide range of laser exposure conditions. Such modelling promises better control of thermal effects for optimizing the fabrication and performance of three-dimensional optical devices in transparent materials.

  5. Radioactive waste processing: Borosilicate glasses and synthetic rocks. (Latest citations from the NTIS bibliographic database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-02-01

    The biliography contains citations concerning radioactive waste processing and disposal by incorporation in borosilicate glasses and synthetic rock materials. Formulations, leach tests and evaluations, melting characteristics, phase determinations, scaled-up processes, and process variables are considered. The Synroc process, and general preparation and evaluation studies are also included. Waste vitrification in materials other than borosilicates and synthetic rocks, and waste fixation using cements and bitumens are discussed in separate bibliographies.(Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  6. Substituted Borosilicate Glasses with Improved Osteogenic Capacity for Bone Tissue Engineering.

    Science.gov (United States)

    Fernandes, João S; Gentile, Piergiorgio; Crawford, Aileen; Pires, Ricardo A; Hatton, Paul V; Reis, Rui L

    2017-03-27

    Borosilicate bioactive glasses (BBGs) have shown the capacity to promote higher formation of new bone when compared with silicate bioactive glasses. Herein, we assessed the capacity of BBGs to induce osteogenic differentiation of bone marrow mesenchymal stem cells (BM-MSCs) as a function of their substituted divalent cations (Mg(2+), Ca(2+), Sr(2+)). To this purpose, we synthesized BBG particles by melt quenching. The cell viability, proliferation, and morphology (i.e., PrestoBlue(®), PicoGreen(®), and DAPI and Phalloidin stainings, respectively), as well as protein expression (i.e., alkaline phosphatase, ALP; osteopontin, OP; and osteocalcin, OC), of BM-MSCs in contact with BBGs were evaluated for 21 days. We observed an enhanced expression of bone-specific proteins (ALP, OP, and OC) and high mineralization of BM-MSCs under BBG-Mg and BBG-Sr-conditioned osteogenic media for concentrations of 20 and 50 mg/mL with low cytotoxic effects. Moreover, BBG-Sr, at a concentration of 50 mg/mL, was able to increase the mineralization and expression of the same bone-specific proteins even under basal medium conditions. These results indicated that the proposed BBGs improved osteogenic differentiation of BM-MSCs, therefore showing their potential as relevant biomaterials for bone tissue regeneration, not only by bonding to bone tissue but also by stimulating new bone formation.

  7. Liquidus Temperature of High-Level Waste Borosilicate Glasses with Spinel Primary Phase

    Energy Technology Data Exchange (ETDEWEB)

    Hrma, Pavel R.(BATTELLE (PACIFIC NW LAB)); Vienna, John D.(BATTELLE (PACIFIC NW LAB)); Crum, Jarrod V.(BATTELLE (PACIFIC NW LAB)); Piepel, Gregory F.(BATTELLE (PACIFIC NW LAB)); Mika, Martin (ASSOC WESTERN UNIVERSITY); Robert W. Smith; David W. Shoesmith

    2000-01-01

    Liquidus temperatures (TL) were measured for high-level waste (HLW) borosilicate glasses covering a Savannah River composition region. The primary crystallization phase for most glasses was spinel, a solid solution of trevorite (NiFe2O4) with other oxides (FeO, MnO, and Cr2O3). The TL values ranged from 859 to 1310?C. Component additions increased the TL (per mass%) as Cr2O3 261?C, NiO 85?C, TiO2 42?C, MgO 33?C, Al2O3 18?C, and Fe2O3 18?C and decreased the TL (per mass%) as Na2O -29?C, Li2O -28?C, K2O -20?C, and B2O3 -8?C. Other oxides (CaO, MnO, SiO2, and U3O8) had little effect. The effect of RuO2 is not clear.

  8. Low temperature sintering and performance of aluminum nitride/borosilicate glass

    Institute of Scientific and Technical Information of China (English)

    Hong-sheng ZHAO; Lei CHEN; Nian-zi GAO; Kai-hong ZHANG; Zi-qiang LI

    2009-01-01

    Aluminum nitride (AlN)/borosilicate glass composites were prepared by the tape casting process and hot-press sin-tered at 950 ℃ with AlN and SiO2-B2O3-ZnO-Al2O3-Li2O glass as starting materials. We characterized and analyzed the variation of the microstructure, bulk density, porosity, dielectric constant, thermal conductivity and thermal expansion coefficient (TEC) of the ceramic samples as a function of AlN content. Results show that AlN and SiO2-B2O3-ZnO-Al2O3-Li2O glass can be sintered at 950 ℃, and ZnAl2O4 and Zn2SiO4 phase precipitated to form glass-ceramic. The performance of the ceramic samples was de-termined by the composition and bulk density of the composites. Lower AlN content was found redounding to liquid phase sin-tering, and higher bulk density of composites can be accordingly obtained. With the increase of porosity, corresponding decreases were located in the dielectric constant, thermal conductivity and TEC of the ceramic samples. When the mass fraction of AlN was 40%, the ceramic samples possessed a low dielectric constant (4.5~5.0), high thermal conductivity (11.6 W/(m·K)) and a proper TEC (3.0×10K-1, which matched that of silicon). The excellent performance makes this kind of low temperature co-fired ce-ramic a promising candidate for application in the micro-electronics packaging industry.

  9. Ultrafast opacity in borosilicate glass induced by picosecond bursts of laser-driven ions

    CERN Document Server

    Dromey, B; Adams, D; Prasad, R; Kakolee, K F; Stefanuik, R; Nersisyan, G; Sarri, G; Yeung, M; Ahmed, H; Doria, D; Dzelzainis, T; Jung, D; Kar, S; Marlow, D; Romagnani, L; Correa, A A; Dunne, P; Kohanoff, J; Schleife, A; Borghesi, M; Currell, F; Riley, D; Zepf, M; Lewis, C L S

    2014-01-01

    Direct investigation of ion-induced dynamics in matter on picosecond (ps, 10-12 s) timescales has been precluded to date by the relatively long nanosecond (ns, 10-9 s) scale ion pulses typically provided by radiofrequency accelerators1. By contrast, laser-driven ion accelerators provide bursts of ps duration2, but have yet to be applied to the study of ultrafast ion-induced transients in matter. We report on the evolution of an electron-hole plasma excited in borosilicate glass by such bursts. This is observed as an onset of opacity to synchronised optical probe radiation and is characterised by the 3.0 +/- 0.8 ps ion pump rise-time . The observed decay-time of 35 +/- 3 ps i.e. is in excellent agreement with modelling and reveals the rapidly evolving electron temperature (>10 3 K) and carrier number density (>10 17cm-3). This result demonstrates that ps laser accelerated ion bursts are directly applicable to investigating the ultrafast response of matter to ion interactions and, in particular, to ultrafast pu...

  10. Characteristics of borosilicate waste glass form for high-level radioactive waste

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seung Soo; Chun, Kwan Sik; Choi, Jong Won; Kang, Chul Hyung

    2001-03-01

    Basic data, required for the design and the performance assessment of a repository of HLW, suchas the chemical composition and the characteristics of the borosilicate waste glass have been identified according to the burn-ups of spent PWR fuels. The diemnsion of waste canister is 430mm in diameter and 1135mm in length, and the canister should hold less than 2kwatts of heat from their decay of radionuclides contained in the HLW. Based on the reprocessing of 5 years-cooled spent fuel, one canister could hold about 11.5wt.% and 10.8wt.% of oxidized HLW corresponding to their burn-ups of 45,000MWD/MTU and 55,000MWD/MTU, respectively. These waste forms have been recommanded as the reference waste forms of HLW. The characteristics of these wastes as a function of decay time been evaluated. However, after a specific waste form and a specific site for the disposal would be selected, the characteristics of the waste should be reevaluated under the consideration of solidification period, loaded waste, storage condition and duration, site circumstances for the repository system and its performance assessment.

  11. Supported TiO2 on Borosilicate Glass Plates for Efficient Photocatalytic Degradation of Fenamiphos

    Directory of Open Access Journals (Sweden)

    A. El Yadini

    2014-01-01

    Full Text Available Supported titanium dioxide (TiO2 was investigated for the photodegradation of the insecticide fenamiphos in water. The photocatalyst was immobilised on borosilicate glass plates and the kinetics of degradation were studied in a stirred tank reactor under UV irradiation. Two types of TiO2, for example, Millennium PC500 (100% anatase and Degussa P25 (80% anatase, 20% rutile, were used. Their activities have been based on the rates of insecticide disappearance. Experiments were investigated to evaluate the effect of pH and initial concentrations of fenamiphos as well as catalyst doses on the photocatalytic degradation of fenamiphos. Kinetic parameters were experimentally determined and an apparent first-order kinetic was observed. For photolysis process of fenamiphos, two photoproducts were identified and characterized using high performance liquid chromatography/mass spectrometry (HPLC/MS. The plausible mechanism of photolysis involved is the oxidation of sulfonamide group. In presence of photocatalyst TiO2, photodegradation was observed. Under identical conditions, Degussa P25 shows higher photocatalytic activity in regard to PC500 Millennium and complete degradation was observed after 180 min.

  12. Reinforcement of poly-L-lactic acid electrospun membranes with strontium borosilicate bioactive glasses for bone tissue engineering

    OpenAIRE

    Fernandes, João S.; Gentile, Piergiorgio; Martins, Margarida Isabel Barros Coelho; Neves, N. M.; Miller, Cheryl; Crawford, Aileen; Pires, R. A.; Hatton, Paul; Reis, R. L.

    2016-01-01

    Herein, for the first time, we combined poly-L-lactic acid (PLLA) with a strontium borosilicate bioactive glass (BBG-Sr) using electrospinning to fabricate a composite bioactive PLLA membrane loaded with 10% (w/w) of BBG-Sr glass par- ticles (PLLA-BBG-Sr). The composites were characterised by scanning electron microscopy (SEM) and microcomputer tomography (μ-CT), and the results showed that we successfully fabricated smooth and uniform fibres (1â 3 μm in width) with a homogeneous distribut...

  13. Color-converted remote phosphor prototype of a multiwavelength excitable borosilicate glass for white light-emitting diodes

    Institute of Scientific and Technical Information of China (English)

    Tian Hua; Liu Ji-Wen; Qiu Kun; Song Jun; Wang Da-Jian

    2012-01-01

    We report a unique red light-emitting Eu-doped borosilicate glass to convert color for warm white light-emitting diodes.This glass can be excited from 394 nm-peaked near ultraviolet light,466 nm-peaked blue light,to 534 nm-peaked green light to emit the desired red light with an excellent transmission in the wavelength range of 400-700 nm which makes this glass suitable for color conversion without a great cost of luminous power loss.In particular,when assembling this glass for commercial white light-emitting diodes,the tested results show that the color rendering index is improved to 84 with a loss of luminous power by 12 percent at average,making this variety of glass promising for inorganic "remote-phosphor" color conversion.

  14. Tungsten-doped vanadium dioxide thin films on borosilicate glass for smart window application

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Zhangli, E-mail: zligthuang@foxmail.com [Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074 (China); School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074 (China); Chen, Changhong, E-mail: ch_chen@hust.edu.cn [Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074 (China); Lv, Chaohong; Chen, Sihai [Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2013-07-05

    Highlights: ► Tungsten-doped VO{sub 2} (W–VO{sub 2}) films with different annealing conditions were fabricated. ► W-VO{sub 2} films were found to exhibit a semiconductor-metal transition at 34 °C. ► The W atoms have been successfully doped into VO{sub 2} film and exist as W{sup 6+} in the films. ► W-VO{sub 2} films possess excellent infrared switching efficiency, i.e. 33%. -- Abstract: Tungsten-doped VO{sub 2} (W–VO{sub 2}) thin films with low metal–semiconductor transition temperature (T{sub t}) of 34 °C were grown on borosilicate glass substrates by reactive ion beam sputtering at room-temperature (RT) followed by a post annealing process. In order to investigate the thermal process effect, four samples S1–S4 were annealed at different temperatures of 490, 530, 570 and 610 °C, respectively. X-ray photoelectron spectroscope and Raman measurements demonstrate that the tungsten atoms have been successfully doped into VO{sub 2} films. Unlike VO{sub 2} thin films which should be annealed at critical temperature, well crystallized W–VO{sub 2} films can be annealed in a wide temperature range, i.e. 530–570 °C, as revealed by both electrical and optical property investigations. Besides, the infrared (IR) transmittance measured below/above T{sub t} illustrates that W–VO{sub 2} films possess excellent switching efficiency, i.e. 33% at 2500 nm for S3. Above all, the near RT phase transition, RT deposition, easy control of annealing process and high IR switching efficiency make the W–VO{sub 2} thin film a promising material for application of smart windows.

  15. Synthesis, electrical and magnetic properties of sodium borosilicate glasses containing Co-ferrites nanoparticles

    Science.gov (United States)

    Othman, H. A.; Eltabey, M. M.; Ibrahim, Samia. E.; El-Deen, L. M. Sharaf; Elkholy, M. M.

    2017-02-01

    Co-ferrites nanoparticles that have been prepared by the co-precipitation method were added to sodium borosilicate (Na2O-B2O3-SiO2) glass matrix by the solid solution method and they were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) and magnetization measurements. (XRD) revealed the formation of the Co-ferrite magnetic crystalline phase embedded in an amorphous matrix in all the samples. The investigated samples by (TEM) showed the formation of the cobalt ferrite nanoparticles with a spherical shape and highly monodispersed with an average size about 13 nm. IR data revealed that the BO3 and BO4 are the main structural units of these samples network. IR spectra of the investigated samples showed the characteristic vibration bands of Co-ferrite. Composition and frequency dependent dielectric properties of the prepared samples were measured at room temperature in the frequency range 100-100 kHz. The conductivity was found to increase with increasing cobalt ferrite content. The variations of conductivity and dielectric properties with frequency and composition were discussed. Magnetic hysteresis loops were traced at room temperature using VSM and values of saturation magnetization MS and coercive field HC were determined. The obtained results revealed that a ferrimagnetic behavior were observed and as Co-ferrite concentration increases the values of MS and HC increase from 2.84 to 8.79 (emu/g) and from 88.4 to 736.3 Oe, respectively.

  16. 信息动态%Spectral Analysis of Ho3+ -doped and Ho3+, Yb3+, Er3+ Co-doped Up-conversion Luminescence Borosilicate Glass

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    A series of holmium ions doped borosilicate glass, including Ho3+ -doped, Ho3+/ Er3+ -doped, Ho3+/ Y Yb3+-doped and Ho3 Yb3 YEr3+ -doped galss, have been prepared by high-temperature melting. The up-conversion excitation spectra and emission spectra of the samples decrease. The analysis result reveals that both the intensities of excitation spectra and emission spectra were weaken with the Ho3+ concentration. The spectral intensities of Ho3+/Yb3+ -doped borosilicate glass increase with the increase of Ho3+ concentration because of the sensitization of Yb3+. The excitation and emission spectra intensities of Ho3+/Yb3 +/Er3+-doped borosilicate glass are weak, and the reason is the energy transfers from Ho3+ ions to Er3+ ions through energy resonant transfer process. Meanwhile the luminescence mechanism of broadband emission peaked at 550 nm is analyzed.

  17. Multi-wavelength excitable europium-doped borosilicate glasses for orange-red emission: composition-induced structure and valence variation

    Institute of Scientific and Technical Information of China (English)

    QIU Kun; TIAN Hua; SONG Jun; MAO Zhiyong; WANG Dajian

    2012-01-01

    Europium-doped borosilicate glasses were prepared by melt-quenching procedure in the air.The mixed valence of Eu2+ and Eu3+was identified by photoluminescence spectrum and electron paramagnetic resonanoe (EPR).The existence of mixed valence was observed owing to the unequivalent substitution and de-polymerization network of the as-prepared borosilicate glasses.The variation of the glass composition in B2O3/BaO ratios changed the stability of the Eu3+ ions distinctly.In particular,as-prepared borosilicate glasses exhibited a tri-wavelength light excitable spectra centered at 397,466 and 534 nm to give the broadened orange-red emission at around 592 and 617 nm,due to supersensitive transitions of Eu3+ ions.This simultaneous tri-wavelength excitation happened to correspond with the emitting wavelength from near ultraviolet,blue AllnGaN chips and that from YAG:Ce3+.The total quantum yield (QY) of the Eu-doped glasses under 466nm excitation was evaluated to be 10%,potentially providing a versatile combination with the europium-doped borosilicate glasses for red component addition to improve the quality of white light.

  18. Study of Au/Cr multilayer thin-film surface morphology, structure and constituents on borosilicate glass, and quartz surfaces

    Science.gov (United States)

    Lavoie, John; Kemble, Eric; Senevirathne, Indrajith

    2014-03-01

    Au/Cr/substrate multilayer thin films have a wide area of applications in both industry and proof of concept investigations in device engineering. Borosilicate glass and quartz are used for substrate materials. Typically, Cr deposition on substrates give rise to Stanski-Krastonov (SK) like growth while Frank-van der Merwe (FM) like growth is desired in many engineering applications. A thermal evaporator is used to deposit Cr with a thickness of ~ 100nm on the previously mentioned substrates. The additional Au layer is then deposited via magnetron sputter deposition at 100mtorr at low deposition rates (~ 1ML/min) onto the Cr thin film. These systems were then annealed using different temperatures for various durations. After annealing these systems were characterized via Atomic Force Microscopy (AFM) probes for surface topography and structure. Further, the ambient contamination and elemental distribution/diffusion at annealing was investigated via Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray spectroscopy (EDX).

  19. Effect of composition and temperature on viscosity and electrical conductivity of borosilicate glasses for Hanford nuclear waste immobilization

    Energy Technology Data Exchange (ETDEWEB)

    Hrma, P.; Piepel, G.F.; Smith, D.E.; Redgate, P.E.; Schweiger, M.J.

    1993-04-01

    Viscosity and electrical conductivity of 79 simulated borosilicate glasses in the expected range of compositions to be produced in the Hanford Waste Vitrification Plant were measured within the temperature span from 950 to 1250[degree]C. The nine major oxide components were SiO[sub 2], B[sub 2]O[sub 3], Li[sub 2]O, Na[sub 2]O, CaO, MgO, Fe[sub 2]O[sub 3], Al[sub 2]O[sub 3], and ZrO[sub 2]. The test compositions were generated statistically. The data were fitted by Fulcher and Arrhenius equations with temperature coefficients being multilinear functions of the mass fractions of the oxide components. Mixture models were also developed for the natural logarithm of viscosity and that of electrical conductivity at 1150[degree]C. Least squares regression was used to obtain component coefficients for all the models.

  20. 3 and 4 oxidation state element solubilities in borosilicate glasses. Implement to actinides in nuclear glasses; Solubilite des elements aux degres d'oxydation (3) et (4) dans les verres de borosilicate. Application aux actinides dans les verres nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Cachia, J.N

    2005-12-15

    In order to ensure optimal radionuclides containment, the knowledge of the actinide loading limits in nuclear waste glasses and also the comprehension of the solubilization mechanisms of these elements are essential. A first part of this manuscript deals with the study of the differences in solubility of the tri and tetravalent elements (actinides and surrogates) particularly in function of the melting temperature. The results obtained indicate that trivalent elements (La, Gd, Nd, Am, Cm) exhibit a higher solubility than tetravalent elements (Hf, Th, Pu). Consequently, it was planned to reduce plutonium at the oxidation state (III), the later being essentially tetravalent in borosilicate glasses. An innovating reduction process of multi-valent elements (cerium, plutonium) using silicon nitride has been developed in a second part of this work. Reduced plutonium-bearing glasses synthesized by Si{sub 3}N{sub 4} addition made it possible to double the plutonium solubility from 2 to 4 wt% at 1200 deg C. A structural approach to investigate the differences between tri and tetravalent elements was finally undertaken. These investigations were carried out by X-rays Absorption Spectroscopy (EXAFS) and NMR. Trivalent rare earth and actinide elements seem to behave as network modifiers while tetravalent elements rather present true intermediaries' behaviour. (author)

  1. RHENIUM SOLUBILITY IN BOROSILICATE NUCLEAR WASTE GLASS IMPLICATIONS FOR THE PROCESSING AND IMMOBILIZATION OF TECHNETIUM-99 (AND SUPPORTING INFORMATION WITH GRAPHICAL ABSTRACT)

    Energy Technology Data Exchange (ETDEWEB)

    AA KRUGER; A GOEL; CP RODRIGUEZ; JS MCCLOY; MJ SCHWEIGER; WW LUKENS; JR, BJ RILEY; D KIM; M LIEZERS; P HRMA

    2012-08-13

    The immobilization of 99Tc in a suitable host matrix has proved a challenging task for researchers in the nuclear waste community around the world. At the Hanford site in Washington State in the U.S., the total amount of 99Tc in low-activity waste (LAW) is {approx} 1,300 kg and the current strategy is to immobilize the 99Tc in borosilicate glass with vitrification. In this context, the present article reports on the solubility and retention of rhenium, a nonradioactive surrogate for 99Tc, in a LAW sodium borosilicate glass. Due to the radioactive nature of technetium, rhenium was chosen as a simulant because of previously established similarities in ionic radii and other chemical aspects. The glasses containing target Re concentrations varying from 0 to10,000 ppm by mass were synthesized in vacuum-sealed quartz ampoules to minimize the loss of Re by volatilization during melting at 1000 DC. The rhenium was found to be present predominantly as Re7 + in all the glasses as observed by X-ray absorption near-edge structure (XANES). The solubility of Re in borosilicate glasses was determined to be {approx}3,000 ppm (by mass) using inductively coupled plasma-optical emission spectroscopy (ICP-OES). At higher rhenium concentrations, some additional material was retained in the glasses in the form of alkali perrhenate crystalline inclusions detected by X-ray diffraction (XRD) and laser ablation-ICP mass spectrometry (LA-ICP-MS). Assuming justifiably substantial similarities between Re7 + and Tc 7+ behavior in this glass system, these results implied that the processing and immobilization of 99Tc from radioactive wastes should not be limited by the solubility of 99Tc in borosilicate LAW glasses.

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

    Science.gov (United States)

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

    2006-07-01

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

  3. Study of optical absorption and photoluminescence of quantum dots of CdS formed in borosilicate glass matrix

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Jitender; Verma, A; Pandey, P K; Bhatnagar, P K; Mathur, P C [Department of Electronic Science, University of Delhi South Campus, Benito Juarez Road, New Delhi-110021 (India); Liu, W; Tang, S H [Department of Physics, National University of Singapore, 119243 (Singapore)], E-mail: jitender_does@yahoo.co.in

    2009-06-15

    Optical absorption and photoluminescence (PL) measurements have been made on the quantum dots (QDs) of CdS grown in a borosilicate glass matrix using a two-step annealing technique. The absorption measurements, made in the energy range of 1.3-3.2 eV, indicate the presence of nonradiative trap centers located in the forbidden gap at an energy level near 1.5 eV. The origin of these traps is attributed to the impurities present in the glass matrix. The PL measurements have been made at an excitation energy of 2.75 eV and it is concluded that the origin of PL is not due to either direct recombination of electrons and holes or deep traps, but that it is the shallow traps which are responsible for the observed PL. The shallow traps are attributed to sulfur vacancies formed at the glass-QD interface. The reason for the observed decrease in PL peak intensity with the increase of annealing time is due to the decrease of surface to volume ratio for QDs of higher size.

  4. Determination of the free enthalpies of formation of borosilicate glasses; Determination des enthalpies libres de formation des verres borosilicates. Application a l'etude de l'alteration des verres de confinement de dechets radioactifs

    Energy Technology Data Exchange (ETDEWEB)

    Linard, Y

    2000-07-01

    This work contributes to the study of the thermochemical properties of nuclear waste glasses. Results are used to discuss mechanisms and parameters integrated in alteration models of conditioning materials. Glass is a disordered material defined thermodynamically as a non-equilibrium state. Taking into account one order parameter to characterise its configurational state, the metastable equilibrium for the glass was considered and the main thermochemical properties were determined. Calorimetric techniques were used to measure heat capacities and formation enthalpies of borosilicate glasses (from 3 to 8 constitutive oxides). Formation Entropies were measured too, using the entropy theory of relaxation processes proposed by Adam and Gibbs (1965). The configurational entropy contribution were determined from viscosity measurements. This set of data has allowed the calculation of Gibb's free energies of dissolution of glasses in pure water. By comparison with leaching experiments, it has been demonstrated that the decreasing of the dissolution rate at high reaction progress cannot be associated to the approach of an equilibrium between the sound glass and the aqueous solution. The composition changes of the reaction area at the glass surface need to be considered too. To achieve a complete description of the thermodynamic stability, the equilibrium between hydrated de-alkalinized glass and/or the gel layer with the aqueous solution should also be evaluated. (author)

  5. Current Understanding and Remaining Challenges in Modeling Long-Term Degradation of Borosilicate Nuclear Waste Glasses

    Energy Technology Data Exchange (ETDEWEB)

    Vienna, John D. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Ryan, Joseph V. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Gin, Stephane [CEA Marcoule, DTCD SECM, Bagnols-sur-Ceze (France); Inagaki, Yaohiro [Dept. of Applied Quantum Physics and Nuclear Engineering, Kyushu University, Fukuoda (Japan)

    2013-12-01

    Chemical durability is not a single material property that can be uniquely measured. Instead it is the response to a host of coupled material and environmental processes whose rates are estimated by a combination of theory, experiment, and modeling. High-level nuclear waste (HLW) glass is perhaps the most studied of any material yet there remain significant technical gaps regarding their chemical durability. The phenomena affecting the long-term performance of HLW glasses in their disposal environment include surface reactions, transport properties to and from the reacting glass surface, and ion exchange between the solid glass and the surrounding solution and alteration products. The rates of these processes are strongly influenced and are coupled through the solution chemistry, which is in turn influenced by the reacting glass and also by reaction with the near-field materials and precipitation of alteration products. Therefore, those processes must be understood sufficiently well to estimate or bound the performance of HLW glass in its disposal environment over geologic time-scales. This article summarizes the current state of understanding of surface reactions, transport properties, and ion exchange along with the near-field materials and alteration products influences on solution chemistry and glass reaction rates. Also summarized are the remaining technical gaps along with recommended approaches to fill those technical gaps.

  6. Structural and crystallization behavior of (Ba,Sr)TiO3 borosilicate glasses

    Science.gov (United States)

    Yadav, Avadhesh Kumar; Gautam, C. R.; Gautam, Arvind; Mishra, Vijay Kumar

    2013-10-01

    Various glass samples were prepared by melt quench technique in the glass system [(Ba1- x Sr x ) TiO3]-[2SiO2-B2O3]-[K2O] doped with 1 mole% of La2O3. Infrared spectra show the number of absorption peaks with different spliting in the wave number range from 450 to 4000 cm-1. Absorption peaks occurs due to asymetric vibrational streching of borate by relaxation of the bond B-O of trigonal BO3. Raman spectra show the Raman bands due to ring-type metaborate anions, symmetric breathing vibrations BO3 triangles replaced by BO4 tetrahedra, and symmetric breathing vibrations of six-member rings. The differential thermal analysis of a glass sample corresponding to composition x = 0.0 shows crystallization temperature at 847°C and glass transition temperature at 688°C. X-ray diffraction (XRD) pattern of glass ceramic samples shows the major crystalline phase of BaTiO3 whereas pyrochlore phases of barium titanium silicate. Scanning electron micrographs confirm the results of XRD as barium titanate is major crystalline phase along with pyrochlore phase of barium titanium silicate.

  7. High-level nuclear waste borosilicate glass: A compendium of characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Cunnane, J.C.; Bates, J.K.; Ebert, W.L.; Feng, X.; Mazer, J.J.; Wronkiewicz, D.J. (Argonne National Lab., IL (United States)); Sproull, J. (Westinghouse Savannah River Co., Aiken, SC (United States)); Bourcier, W.L. (Lawrence Livermore National Lab., CA (United States)); McGrail, B.P. (Battelle Pacific Northwest Lab., Richland, WA (United States))

    1992-01-01

    With the imminent startup, in the United States, of facilities for vitrification of high-level nuclear waste, a document has been prepared that compiles the scientific basis for understanding the alteration of the waste glass products under the range of service conditions to which they may be exposed during storage, transportation, and eventual geologic disposal. A summary of selected parts of the content of this document is provided. Waste glass alterations in a geologic repository may include corrosion of the glass network due to groundwater and/or water vapor contact. Experimental testing results are described and interpreted in terms of the underlying chemical reactions and physical processes involved. The status of mechanistic modeling, which can be used for long-term predictions, is described and the remaining uncertainties associated with long-term simulations are summarized.

  8. High-level nuclear waste borosilicate glass: A compendium of characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Cunnane, J.C.; Bates, J.K.; Ebert, W.L.; Feng, X.; Mazer, J.J.; Wronkiewicz, D.J. [Argonne National Lab., IL (United States); Sproull, J. [Westinghouse Savannah River Co., Aiken, SC (United States); Bourcier, W.L. [Lawrence Livermore National Lab., CA (United States); McGrail, B.P. [Battelle Pacific Northwest Lab., Richland, WA (United States)

    1992-12-01

    With the imminent startup, in the United States, of facilities for vitrification of high-level nuclear waste, a document has been prepared that compiles the scientific basis for understanding the alteration of the waste glass products under the range of service conditions to which they may be exposed during storage, transportation, and eventual geologic disposal. A summary of selected parts of the content of this document is provided. Waste glass alterations in a geologic repository may include corrosion of the glass network due to groundwater and/or water vapor contact. Experimental testing results are described and interpreted in terms of the underlying chemical reactions and physical processes involved. The status of mechanistic modeling, which can be used for long-term predictions, is described and the remaining uncertainties associated with long-term simulations are summarized.

  9. Investigation of optical, structural properties of Eu3+ by Mn2+ in barium alumino borosilicate glasses

    Science.gov (United States)

    Lakshmi, P. Vijaya; Rao, T. G. V. M.; Neeraja, K.; Krishna Reddy, D. V.; Rami Reddy, M.

    2016-12-01

    The Mn2+ ions doped Eu2O3sbnd BaOsbnd Al2O3sbnd B2O3sbnd SiO2 glasses are synthesized by conventional melt quenching method. The effect of Mn2+ ions on spectroscopic, structural properties of Eu3+ ions in glass networks is analysed. An analysis of XRD traces evidently suggests the glassy nature of the prepared samples. The UV-Vis absorption and the luminescence spectra have been used to study the variations in the optical character of Eu3+ ions. In luminescence spectra five bands can be observed at about 578, 590, 612, 653 and 702 nm as a result of transitions of Eu3+ ions from 5D0→7F0, 1, 2, 3, 4 respectively. By gradual increment of MnO mol% in the glass matrix, the strong variation in the intensity of emission band are observed at about 612 nm (5D0→7F2). The non-radiative energy transfer (Mn2+ ↔ Eu3+) and concentration quenching are observed in the prepared glasses. The ESR spectra exhibit a sixtet hyperfine structure centered at g = ∼2.0047 which suggests that manganese ions predominantly occupy octahedral positions.

  10. Conceptual waste package interim product specifications and data requirements for disposal of borosilicate glass defense high-level waste forms in salt geologic repositories

    Energy Technology Data Exchange (ETDEWEB)

    1983-06-01

    The conceptual waste package interim product specifications and data requirements presented are applicable specifically to the normal borosilicate glass product of the Defense Waste Processing Facility (DWPF). They provide preliminary numerical values for the defense high-level waste form parameters and properties identified in the waste form performance specification for geologic isolation in salt repositories. Subject areas treated include containment and isolation, operational period safety, criticality control, waste form/production canister identification, and waste package performance testing requirements. This document was generated for use in the development of conceptual waste package designs in salt. It will be revised as additional data, analyses, and regulatory requirements become available.

  11. Ce(3+)/Yb(3+)/Er(3+) triply doped bismuth borosilicate glass: a potential fiber material for broadband near-infrared fiber amplifiers.

    Science.gov (United States)

    Chu, Yushi; Ren, Jing; Zhang, Jianzhong; Peng, Gangding; Yang, Jun; Wang, Pengfei; Yuan, Libo

    2016-09-20

    Erbium doped bismuth borosilicate (BBS) glasses, possessing the broadest 1.55 μm near infrared (NIR) emission band among oxide glasses, stand out as excellent fiber material for optical fiber amplifiers. In this work, we demonstrate that both broadened and enhanced NIR emission of Er(3+) can be obtained by sensibly combining the effects such as mixed glass former effect, phonon-assisted energy transfer (PAET) and de-excitation effect induced by codopant. Specially, by codoping CeO2 in a controlled manner, it leads to not only much improved optical quality of the glasses, enhanced NIR emission, but also significantly suppressed energy transfer up-conversion (ETU) luminescence which is detrimental to the NIR emission. Cerium incorporated in the glasses exists overwhelmingly as the trivalent oxidation state Ce(3+) and its effects on the luminescence properties of Er(3+) are discussed. Judd-Ofelt analysis is used to evaluate gain amplification of the glasses. The result indicates that Ce(3+)/Yb(3+)/Er(3+) triply doped BBS glasses are promising candidate for erbium doped fiber amplifiers. The strategy described here can be readily extended to other rare-earth ions (REs) to improve the performance of REs doped fiber lasers and amplifiers.

  12. Ce3+/Yb3+/Er3+ triply doped bismuth borosilicate glass: a potential fiber material for broadband near-infrared fiber amplifiers

    Science.gov (United States)

    Chu, Yushi; Ren, Jing; Zhang, Jianzhong; Peng, Gangding; Yang, Jun; Wang, Pengfei; Yuan, Libo

    2016-01-01

    Erbium doped bismuth borosilicate (BBS) glasses, possessing the broadest 1.55 μm near infrared (NIR) emission band among oxide glasses, stand out as excellent fiber material for optical fiber amplifiers. In this work, we demonstrate that both broadened and enhanced NIR emission of Er3+ can be obtained by sensibly combining the effects such as mixed glass former effect, phonon-assisted energy transfer (PAET) and de-excitation effect induced by codopant. Specially, by codoping CeO2 in a controlled manner, it leads to not only much improved optical quality of the glasses, enhanced NIR emission, but also significantly suppressed energy transfer up-conversion (ETU) luminescence which is detrimental to the NIR emission. Cerium incorporated in the glasses exists overwhelmingly as the trivalent oxidation state Ce3+ and its effects on the luminescence properties of Er3+ are discussed. Judd-Ofelt analysis is used to evaluate gain amplification of the glasses. The result indicates that Ce3+/Yb3+/Er3+ triply doped BBS glasses are promising candidate for erbium doped fiber amplifiers. The strategy described here can be readily extended to other rare-earth ions (REs) to improve the performance of REs doped fiber lasers and amplifiers. PMID:27646191

  13. Acquisition of rheological and calorimetric properties of borosilicate glass to determine the free energy of formation; Determination des energies libres de formation des verres borosilicates par des mesures calorimetriques et viscosimetriques

    Energy Technology Data Exchange (ETDEWEB)

    Linard, Y. [CEA Valrho, (DCC/DRRV/SCD), 30 - Marcoule (France)]|[Institut de Physique du Globe de Paris, Dept. des Geomateriaux, 75 - Paris (France); Advocat, Th. [CEA Valrho, (DCC/DRRV/SSCD), 30 - Marcoule (France)

    2000-07-01

    No fundamental thermodynamic data, such as the entropy {delta}{sub f}S T) and enthalpy {delta}{sub f}H T) of formation are currently available for nuclear borosilicate glasses. They are necessary to assess the glass thermodynamic stability in water, one of the most important potential long-term glass alteration vectors. Three glass composition ranges were investigated: - 8 compositions ranging from a ternary B{sub 2}O{sub 3}-SiO{sub 2}--Na{sub 2}O (BSN) glass to the simulated SON 68 industrial glass for containment of high active nuclear wastes after reprocessing spent uranium oxide fuel from light water reactors. The basic BSN glass was gradually modified with the additives: Al{sub 2}O{sub 3}, CaO, ZrO{sub 2}, Ce{sub 2}O{sub 3}, Li{sub 2}O and Fe{sub 2}O{sub 3}, and non-radioactive surrogate fission product oxides. - A second using another BSN ternary glass to which Al{sub 2}O{sub 3}, MgO and a group of non-radioactive surrogate fission product oxides, representative of natural uranium GCR fuel, were added. - A third range consisting of various BSN ternary glass compositions. All the glass specimens were fabricated by melting the oxides, carbonates anal nitrates at 1273 to 1473 K in a platinum crucible. Experimental methods based on calorimetry and viscosimetry techniques were used to determine the heat capacity Cp of each glass composition, a necessary parameter in addition to the known heat capacities of the basic glass component oxides, for calculating {delta}{sub f}S T) and {delta}{sub f}S T). The heat capacity Cp was measured between 273 K and 1480 K through a combination of three experimental devices: a low-temperature adiabatic calorimeter, a differential scanning calorimeter, and an ice calorimeter. The glass configuration entropy S{sup conf}(T{sub g}) necessary to obtain the glass entropy of formation (Eqn.(3)) was determined from tile glass rheological properties. A low-temperature viscosimeter was used to measure the strain {epsilon} of a glass specimen

  14. The application of fluorinated aromatic dimethacrylates to experimental light-cured radiopaque composite resin, containing barium-borosilicate glass filler--a progress in nonwaterdegradable properties.

    Science.gov (United States)

    Tanaka, J; Inoue, K; Masamura, H; Matsumura, K; Nakai, H; Inoue, K

    1993-06-01

    This study investigated the durability, especially the nonwaterdegradable qualities, of experimental light-cured composite resin containing barium-borosilicate glass filler. For this purpose, Bis-GMA, a typical component of base monomer in conventional composite resin, was replaced by Bis-GMA-F which is water-repellent. After over 20,000 thermal cycles, the composite resin containing Bis-GMA retained only 60 approximately 70% of its initial compressive, diametral tensile, flexural strength and flexural elastic modulus. However, the experimental composite resin containing Bis-GMA-F as a resin matrix showed no loss of compressive, diametral tensile strength or flexural elastic modulus, although flexural strength showed some deterioration. It was considered that the difference between Bis-GMA-F and Bis-GMA, as resin matrix, caused variation in the characteristics of water sorption.

  15. Atom-Probe Tomography, TEM and ToF-SIMS study of borosilicate glass alteration rim: A multiscale approach to investigating rate-limiting mechanisms

    Science.gov (United States)

    Gin, S.; Jollivet, P.; Barba Rossa, G.; Tribet, M.; Mougnaud, S.; Collin, M.; Fournier, M.; Cadel, E.; Cabie, M.; Dupuy, L.

    2017-04-01

    Significant efforts have been made into understanding the dissolution of silicate glasses and minerals, but there is still debate about the formation processes and the properties of surface layers. Here, we investigate glass coupons of ISG glass - a 6 oxide borosilicate glass of nuclear interest - altered at 90 °C in conditions close to saturation and for durations ranging from 1 to 875 days. Altered glass coupons were characterized from atomic to macroscopic levels to better understand how surface layers become protective. With this approach, it was shown that a rough interface, whose physical characteristics have been modeled, formed in a few days and then propagated into the pristine material at a rate controlled by the reactive transport of water within the growing alteration layer. Several observations such as stiff interfacial B, Na, and Ca profiles and damped profiles within the rest of the alteration layer are not consistent with the classical inter-diffusion model, or with the interfacial dissolution-precipitation model. A new paradigm is proposed to explain these features. Inter-diffusion, a process based on water ingress into the glass and ion-exchange, may only explain the formation of the rough interface in the early stage of glass corrosion. A thin layer of altered glass is formed by this process, and as the layer grows, the accessibility of water to the reactive interface becomes rate-limiting. As a consequence, only the most easily accessible species are dissolved. The others remain undissolved in the alteration layer, probably fixed in highly hydrolysis resistant clusters. A new estimation of water diffusivity in the glass when covered by the passivating layer was determined from the shift between B and H profiles, and was 10-23 m2.s-1, i.e. approximately 3 orders of magnitude lower than water diffusivity in the pristine material. Overall, in the absence of secondary crystalline phases that could consume the major components of the alteration

  16. Influence of Ce, Nd, Sm and Gd oxides on the properties of alkaline-earth borosilicate glass sealant

    Directory of Open Access Journals (Sweden)

    Nibedita Sasmal

    2016-03-01

    Full Text Available In this study, the influence of CeO2, Nd2O3, Sm2O3 and Gd2O3 on various properties of the melt-quench route derived SrO–CaO–ZnO–B2O3–SiO2 glass have been investigated. Both the precursor glasses and heat treated glasses are characterized by dilatometry, differential scanning calorimetry (DSC, X-ray diffraction (XRD, field emission scanning electron microscopy (FESEM, Fourier transformed infrared spectroscopy (FTIR and X-ray photoelectron spectroscopy (XPS. The density and coefficient of thermal expansion of the glasses varies in the range 3.557–3.804 g cm−3 and 10.5–11.2 × 10−6 K−1 (50–800 °C respectively. Decrease in crystallization tendency with increase in cationic field strength of the ions is well supported by the increasing crystallization activation energy of the glasses calculated by Kissinger, Augis–Bennett and Ozawa models. XPS study revealed the presence of both Ce3+ and Ce4+ ions and an increase in characteristic binding energy of the respective rare earth elements from their core level studies. The Knoop hardness of the glasses varies in the range 6.03–6.28 GPa. The glass transition, glass softening and crystallization temperature; density and hardness of the glasses increased with increase in cationic field strength of the incorporated ions. The thermomechanical properties of the Gd2O3 containing glass advocate its applicability as the most promising sealant in solid oxide fuel cell.

  17. Influence of Ce, Nd, Sm and Gd oxides on the properties of alkaline-earth borosilicate glass sealant

    OpenAIRE

    Nibedita Sasmal; Mrinmoy Garai; Basudeb Karmakar

    2016-01-01

    In this study, the influence of CeO2, Nd2O3, Sm2O3 and Gd2O3 on various properties of the melt-quench route derived SrO–CaO–ZnO–B2O3–SiO2 glass have been investigated. Both the precursor glasses and heat treated glasses are characterized by dilatometry, differential scanning calorimetry (DSC), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Fourier transformed infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The density and coefficient of ...

  18. Effect of focusing condition on molten area characteristics in micro-welding of borosilicate glass by picosecond pulsed laser

    Energy Technology Data Exchange (ETDEWEB)

    Nordin, I.H.W.; Okamoto, Y.; Okada, A.; Takekuni, T. [Okayama University, Graduate School of Natural Science and Technology, Okayama (Japan); Sakagawa, T. [Kataoka Corporation, Yokohama (Japan)

    2016-05-15

    The characteristics of the molten area are attributed not only by laser energy condition but also the focusing condition. In this study, a picosecond pulsed laser of 1064 nm in wavelength and 12.5 ps in pulse duration was used as a laser source for joining glass material. Influence of focusing condition on micro-welding of glasses was experimentally investigated by using an objective lens with and without spherical aberration correction, and its molten area was characterized. The usage of objective lens with spherical aberration correction led to a larger molten area inside the bulk material of glass even under the same pulse energy, which related to the efficient micro-welding of glass materials. In addition, an optical system with the spherical aberration correction led to a stable absorption of laser energy inside the bulk glass material, stabilizing the shape of molten area, which resulted in the reliable weld joint. On the other hand, breaking strength of the specimens with spherical aberration correction was higher than that without spherical aberration correction. Therefore, it is concluded that the focusing condition with spherical aberration correction led to the larger and stable molten area, which resulted in higher joining strength in micro-welding of glass materials. (orig.)

  19. Volatility mechanisms of borosilicate glasses and molten glasses of nuclear interest structural effects; Mecanismes de volatilite des verres et des fontes borosilicates d'interet nucleaire influence de la structure

    Energy Technology Data Exchange (ETDEWEB)

    Delorme, L

    1998-04-23

    This work is devoted to the study of the mechanisms which control the volatility of the reference glass used for the confinement of radioactive waste. It was conducted on simplified compositions, in the SiO{sub 2}-B{sub 2}O{sub 3}-Al{sub 2}O{sub 3}-{alpha}Na{sub 2}O-(1-alpha)Li{sub 2}O-CaO system.The structural approach carried out by NMR, from room temperature up to 1500 deg.C, shows a strong increase in the mobility of alkalis above Tg. A rapid exchange between B{sup III} and B{sup IV} sites near 700 deg.C, and the change of coordination number B{sup IV-} B{sup III} near 1100 deg.C, also seem to take place. The analysis of the vapor phase, carried out by High Temperature Mass Spectrometry coupled to Knudsen cells, reveals the presence between 780 deg.C and 830 deg.C of NaBO{sub 2}(g), LiBO{sub 2}(g) and Na{sub 2}(BO{sub 2})2(g). The calculation of the partial pressure of each species shows that the total pressure of simplified glasses is dominated by the contribution of sodium. To study the volatility of glasses at higher temperature, equipment using the Transpiration method was used. The analysis of the deposits indicate the presence at 1060 deg.C of the species quoted previously. The vaporization rate and the vapor density were determined for each composition studied in a saturated state. Thus, we show that the volatility of the reference glass can be simulated by that of a simplified glass. For {alpha}=1, the kinetic of vaporization between 1060 deg.C and 1200 deg.C reveals an evaporation from the surface associated with a mechanism of diffusion in the molten glass. This is similar to the volatility of the reference glass at 1060 deg.C. To finally explain these mechanisms on a microscopic basis, we develop a model of molecular interactions. Between 780 deg.C and 830 deg.C, these mechanisms are controlled by a strong attraction between Na{sub 2}O and Li{sub 2}O, which maintains the total vapor pressure on a quasi-constant lever up to {alpha}=0.27. (author)

  20. Ductilizing Bulk Metallic Glass Composite by Tailoring Stacking Fault Energy

    Science.gov (United States)

    Wu, Y.; Zhou, D. Q.; Song, W. L.; Wang, H.; Zhang, Z. Y.; Ma, D.; Wang, X. L.; Lu, Z. P.

    2012-12-01

    Martensitic transformation was successfully introduced to bulk metallic glasses as the reinforcement micromechanism. In this Letter, it was found that the twinning property of the reinforcing crystals can be dramatically improved by reducing the stacking fault energy through microalloying, which effectively alters the electron charge density redistribution on the slipping plane. The enhanced twinning propensity promotes the martensitic transformation of the reinforcing austenite and, consequently, improves plastic stability and the macroscopic tensile ductility. In addition, a general rule to identify effective microalloying elements based on their electronegativity and atomic size was proposed.

  1. Effects of alpha radiation on hardness and toughness of the borosilicate glass applied to radioactive wastes immobilization; Efectos de la radiacion alfa en la dureza y tenacidad de un vidrio borosilicato utilizado para inmovilizacion de residuos nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Prado, Miguel Oscar; Bernasconi, Norma B. Messi de; Bevilacqua, Arturo Miguel; Arribere, Maria Angelica; Heredia, Arturo D.; Sanfilippo, Miguel [Comision Nacional de Energia Atomica, San Carlos de Bariloche (Argentina). Centro Atomico Bariloche

    1999-11-01

    Borosilicate german glass SG7 samples, obtained by frit sintering, were irradiated with different fluences of thermal neutrons in the nucleus of a nuclear reactor. The nuclear reaction {sup 10} B(n,{alpha}){sup 7} Li, where the {sup 10} B isotope is one of the natural glass components, was used to generate alpha particles throughout the glass volume. The maximum alpha disintegration per unit volume achieved was equivalent to that accumulated in a borosilicate glass with nuclear wastes after 3.8 million years. Through Vickers indentations values for microhardness, stress for 50% fracture probability (Weibull statistics) and estimation of the toughness were obtained as a function of alpha radiation dose. Two counterbalanced effects were found: that due to the disorder created by the alpha particles in the glass and that due to the annealing during irradiation (temperature below 240 deg C). Considering the alpha radiation effect, glasses tend decrease Vickers hardness, and to increase thr 50% fracture probability stress with the dose increase. (author) 11 refs., 6 figs., 2 tabs.

  2. OXYGEN BUBBLE DEVELOPMENT ON A PLATINUM ELECTRODE IN BOROSILICATE GLASS MELT BY THE EFFECT OF ALTERNATING CURRENT

    Directory of Open Access Journals (Sweden)

    Jiri Matej

    2014-10-01

    or on alternating reduction and re-forming of oxidic layer on the electrode in the transition range, has been suggested. Start of bubble evolution at low alternating current density has also been observed in simple sodium-calcium-silicate glass melt. A relation between bubble release and platinum corrosion caused by reduced silicon has been suggested

  3. Tailoring properties of porous Poly (vinylidene fluoride) scaffold through nano-sized 58s bioactive glass.

    Science.gov (United States)

    Shuai, Cijun; Huang, Wei; Feng, Pei; Gao, Chengde; Shuai, Xiong; Xiao, Tao; Deng, Youwen; Peng, Shuping; Wu, Ping

    2016-01-01

    The biological properties of porous poly (vinylidene fluoride) (PVDF) scaffolds fabricated by selective laser sintering were tailored through nano-sized 58s bioactive glass. The results showed that 58s bioactive glass distributed evenly in the PVDF matrix. There were some exposed particles on the surface which provided attachment sites for biological response. It was confirmed that the scaffolds had highly bioactivity by the formation of bone-like apatite in simulated body fluid. And the bone-like apatite became dense with the increase in 58s bioactive glass and culture time. Moreover, the scaffolds were suitable for cell adhesion and proliferation compared with the PVDF scaffolds without 58s bioactive glass. The research showed that the PVDF/58s bioactive glass scaffolds had latent application in bone tissue engineering.

  4. β-Irradiation Effects on the Formation and Stability of CaMoO4 in a Soda Lime Borosilicate Glass Ceramic for Nuclear Waste Storage.

    Science.gov (United States)

    Patel, Karishma B; Boizot, Bruno; Facq, Sébastien P; Lampronti, Giulio I; Peuget, Sylvain; Schuller, Sophie; Farnan, Ian

    2017-02-06

    Molybdenum solubility is a limiting factor to actinide loading in nuclear waste glasses, as it initiates the formation of water-soluble crystalline phases such as alkali molybdates. To increase waste loading efficiency, alternative glass ceramic structures are sought that prove resistant to internal radiation resulting from radioisotope decay. In this study, selective formation of water-durable CaMoO4 in a soda lime borosilicate is achieved by introducing up to 10 mol % MoO3 in a 1:1 ratio to CaO using a sintering process. The resulting homogeneously dispersed spherical CaMoO4 nanocrystallites were analyzed using electron microscopy, X-ray diffraction (XRD), Raman and electron paramagnetic resonance (EPR) spectroscopies prior to and post irradiation, which replicated internal β-irradiation damage on an accelerated scale. Following 0.77 to 1.34 GGy of 2.5 MeV electron radiation CaMoO4 does not exhibit amorphization or significant transformation. Nor does irradiation induce glass-in-glass phase separation in the surrounding amorphous matrix, or the precipitation of other molybdates, thus proving that excess molybdenum can be successfully incorporated into a structure that it is resistant to β-irradiation proportional to 1000 years of storage without water-soluble byproducts. The CaMoO4 crystallites do however exhibit a nonlinear Scherrer crystallite size pattern with dose, as determined by a Rietveld refinement of XRD patterns and an alteration in crystal quality as deduced by anisotropic peak changes in both XRD and Raman spectroscopy. Radiation-induced modifications in the CaMoO4 tetragonal unit cell occurred primarily along the c-axis indicating relaxation of stacked calcium polyhedra. Concurrently, a strong reduction of Mo(6+) to Mo(5+) during irradiation is observed by EPR, which is believed to enhance Ca mobility. These combined results are used to hypothesize a crystallite size alteration model based on a combination of relaxation and diffusion

  5. Luminescence Properties of Eu/Tm/Tb-doped Borosilicate Glass%Eu/Tm/Tb掺杂硼硅酸盐玻璃的发光性能

    Institute of Scientific and Technical Information of China (English)

    石冬梅; 赵营刚

    2016-01-01

    Eu/Tm/Tb-doped singly, doubly and triply borosilicate glasses were prepared using a conventional melting-quenching method. The luminescent properties of Eu/Tm/Tb-doped samples under the UV excitation were investigated in detail by measuring the excitation and emission spectra and calculating CIE chromaticity coordinates. The results show that the sharp emission peak centered at 459 nm originating from 1 D2→3 F4 of Tm3+ is observed, and the characteristic emission intensity centered at 437 nm ascribing to the broad peak of Eu2+, 589 nm( 5 D0→7 F1 ) and 612 nm( 5 D0→7 F2 ) of Eu3+ is reduced due to the energy transfer from Eu3+,Eu2+ to Tm3+ ion. Red, green and blue light can be observed in Eu/Tm/Tb-doped triply samples simultaneously under the excitation of 377 nm. The luminescent intensity and color of borosilicate glasses might be changed by adjusting Eu2 O3 content, and the sample with CIE chromaticity coordinates(0. 33, 0. 386 7)are obtained.%采用熔融淬冷法制备了性能优越的Eu/Tm/Tb单掺、双掺和三掺的硼硅酸盐玻璃。测试了样品的激发和发射光谱,计算了CIE色坐标,研究了紫外激发下Eu/Tm/Tb掺杂的硼硅酸盐玻璃的发光性能。结果表明:在361 nm激发下,随着Tm3+加入到Eu2O3掺杂的硼硅酸盐样品中,观察到Tm3+的459 nm(1D2→3F4)锐线特征发射峰,同时由于Eu3+,Eu2+→Tm3+的能量传递的存在降低了Eu2+的437 nm宽带峰及Eu3+的589 nm(5 D0→7 F1)和612 nm(5 D0→7 F2)的特征发射峰强度。在377 nm激发下,Eu/Tm/Tb三掺样品能够同时出现红、绿和蓝光。调节 Eu2O3的含量能有效改变发光玻璃的发光强度和颜色,最终得到色坐标为(0.33,0.3867)的发光玻璃。

  6. Influence of gel morphology on the corrosion kinetics of borosilicate glass: calcium and zirconium effect; Influence de la morphologie du gel sur la cinetique d'alteration des verres borosilicates: role du calcium et du zirconium

    Energy Technology Data Exchange (ETDEWEB)

    Cailleteau, C

    2008-12-15

    This study is related to the question of the long-term behaviour of the nuclear waste confinement glass. A glass alteration layer (known as the 'gel'), formed at the glass surface in contact with water, can limit the exchanges between the glass and the solution. We studied five oxide based glasses SiO{sub 2}-B{sub 2}O{sub 3}-Na{sub 2}O-CaO-ZrO{sub 2}. Two series of glasses were synthesized by substituting CaO for Na{sub 2}O and ZrO{sub 2} for SiO{sub 2}. The leaching showed that the presence of Ca improves the reticulation of the vitreous network, inducing a decrease in the final degree of corrosion and the presence of Zr prevents the hydrolysis of silicon, which leads to a decrease of the initial dissolution rate. However, the introduction of Zr delays the drop of the alteration rate and leads to an increase in the alteration degree. In order to explain this unexpected behaviour, the gel morphology was investigated by small angle X-ray scattering. These experiments showed that the restructuring of porous network during the glass alteration process is limited by the increase of the Zr-content. Then, the restructuring of gel is at the origin of the major drop in the alteration rate observed for the low Zr-content glasses. Besides, both time-of-flight secondary-ion mass spectroscopy (ToF-SIMS) that provides an evaluation of extraneous element penetration into the gel pores and neutron scattering with index matching showed that the porosity closed during the corrosion in the glass without zirconia, but remained open in the high Zr-content glasses. These experiments, associated to simulations by a Monte Carlo method, establish a relationship between the morphologic transformations of gel and the alteration kinetics. (author)

  7. Irradiations effects on the structure of boro-silicated glasses: long term behaviour of nuclear waste glassy matrices; Effets d'irradiations sur la structure de verres borosilicates - comportement a long terme des matrices vitreuses de stockage des dechets nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Bonfils, J. de

    2007-09-15

    This work deals with the long term behaviour of R7T7-type nuclear waste glasses and more particularly of non-active boro-silicated glasses made up of 3 or 5 oxides. Radioactivity of active glasses is simulated by multi energies ions implantations which reproduce the same defects. The damages due to the alpha particles are simulated by helium ions implantations and those corresponding to the recoil nucleus are obtained with gold ions ones. Minor actinides, stemming from the used fuel, is simulated by trivalent rare-earths (Eu{sup 3+} and Nd{sup 3+}). In a first part, we have shown by macroscopic experiments (Vickers hardness - swelling) and optical spectroscopies (Raman - ATR-IR) that the structure of the glassy matrices is modified under implantations until a dose of 2,3.10{sup 13} at.cm{sup -2}, which corresponds to a R7T7 storage time estimated at 300 years. Beyond this dose, no additional modifications have been observed. The second part concerns the local environment of the rare-earth ions in glasses. Two different environments were found and identified as follows: one is a silicate rich one and the other is attributed to a borate rich one. (author)

  8. Lanthanide-activated Na{sub 5}Gd{sub 9}F{sub 32} nanocrystals precipitated from a borosilicate glass: Phase-separation-controlled crystallization and optical property

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Daqin, E-mail: dqchen@hdu.edu.cn [College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China); Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Institute of Research on the Structure of Matter, CAS, Fuzhou 350002 (China); Wan, Zhongyi; Zhou, Yang [College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China); Chen, Yan, E-mail: chenyan@hdu.edu.cn [College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China); Yu, Hua; Lu, Hongwei; Ji, Zhenguo [College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China); Huang, Ping, E-mail: phuang@fjirsm.ac.cn [Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Institute of Research on the Structure of Matter, CAS, Fuzhou 350002 (China)

    2015-03-15

    Highlights: • Na{sub 5}Gd{sub 9}F{sub 32} nanocrystals embedded glass ceramics were fabricated for the first time. • Such glass ceramics were achieved by phase-separation-controlled crystallization. • Elemental mapping evidenced the segregation of activators into the Na{sub 5}Gd{sub 9}F{sub 32} lattice. • Luminescent color could be tuned by controlling glass crystallization temperature. - Abstract: Lanthanide-activated cubic Na{sub 5}Gd{sub 9}F{sub 32} nanocrystals were precipitated from a borosilicate glass with a specifically designed composition. The precursor glass is already phase-separated after melt-quenching, which is beneficial to the realization of the controllable glass crystallization for affording desirable size, morphology and activator partition. Elemental mapping in the scanning transmission electron microscopy evidenced that the segregation of lanthanide ions into the Na{sub 5}Gd{sub 9}F{sub 32} lattice was in situ formed without the requirement of long-range ionic diffusion. Impressively, such fabricated glass ceramic co-doped with Yb{sup 3+}/Er{sup 3+} ions exhibited intense upconversion luminescence, which was about 500 times higher than that of the precursor glass, and its luminescent color could be easily tuned from red to green by controlling glass crystallization temperature. It is anticipated that such phase-separation synthesis strategy with precise control over nanostructure of glass ceramics offer a great opportunity to design other highly transparent nanocomposites with a wide range of tunable optical properties.

  9. Mechanisms of wear in single- and two-phase materials: Final report. [Cu, Pb, Al/sub 2/O/sub 3/, Pb borosilicate glass, SiC (Pb-Cu), (Pb-Al/sub 2/O/sub 3/), (glass-Cu), (glass-Al/sub 2/O/sub 3/)

    Energy Technology Data Exchange (ETDEWEB)

    Macmillan, N.H.

    1987-11-01

    A comparative study has been made of the rolling-tumbling-sliding wear and solid particle erosion behavior of four single-phase materials (Cu, Pb, Al/sub 2/O/sub 3/, and a lead borosilicate glass and of series of ductile-ductile (Pb-Cu), ductile-brittle (Pb-Al/sub 2/O/sub 3/), brittle-ductile (glass-Cu), and brittle-brittle (glass-Al/sub 2/O/sub 3/) composites prepared from them. The same irregularly shaped 600 ..mu..m WC-8 wt.% Co abrasive particles were used throughout this work. Additional erosion measurements have been made on Danto Koruntz, Abresist, and sintered ..cap alpha..-SiC, using similar particles. Some subtle influences of erosive particle wear are documented for the first time, and the inadequacy of the currently available theoretical models to describe the influence of microstructure on erosion is exposed. 77 refs., 154 figs.

  10. Ultra broadband flat dispersion tailoring on reversed-rib chalcogenide glass waveguide

    Science.gov (United States)

    Zhai, Yanfen; Qi, Renduo; Yuan, Chenzhi; Zhang, Wei; Huang, Yidong

    2016-11-01

    In this paper, we introduce a horizontal slot in the reversed-rib chalcogenide glass waveguide to tailor its dispersion characteristics. The waveguide exhibits a flat and low dispersion over a wavelength range of 1080 nm, in which the dispersion fluctuates between -10.6 ps·nm-1·km-1 and +11.14 ps·nm-1·km-1. The dispersion tailoring effect is due to the mode field transfer from the reversed-rib waveguide to the slot with the increase of wavelength, which results in the extension of the low dispersion band. Moreover, the nonlinear coefficient and the phase-matching condition of the four-wave mixing process in this waveguide are studied, showing that the waveguide has great potential in nonlinear optical applications over a wide wavelength range. Project supported by the National Basic Research Program of China (Grant Nos. 2013CB328700 and 2011CBA00303) and the National Natural Science Foundation of China (Grant Nos. 61575102 and 61321004).

  11. 球磨时间对硼硅玻璃基复相陶瓷性能的影响%Effects of grinding time on properties of borosilicate glass composite ceramics

    Institute of Scientific and Technical Information of China (English)

    王杰; 周洪庆; 韦鹏飞; 张一源; 曾风

    2011-01-01

    Low-temperature sintering borosilicate glass composite ceramics were prepared by the borosilicate glass powders with different grinding time and alumina powders. The effects of grinding time on the tape casting, sintering properties and dielectric properties (at 10 MHz) of prepared composite ceramic were investigated by XRD and SEM. The results show that the particle sizes, sintering temperature, permittivity and dielectric loss all decrease, while the density increases, as the grinding time increases. The sample grinded for 90 min and sintered at 850 ℃ possess better properties: a density of about 3.22 g · cm-3, a relative permittivity of 7.92 and a dielectric loss of 1.2 × 10-4 at 10 MHz.%采用经过不同球磨时间制备的硼硅玻璃与氧化铝复合,低温烧结制备了硼硅玻璃/氧化铝系复相陶瓷.利用XRD和SEM,研究了硼硅玻璃粉料球磨时间对流延成型及所制复相陶瓷的烧结性能、介电性能(10MHz)的影响.结果表明:随着球磨时间增加,粉料粒径减小,硼硅玻璃复相陶瓷烧结温度降低,密度增加,介电常数和介质损耗降低.球磨90 min在850℃烧结的试棒性能较佳:密度为3.22 g·cm-3,10 MHz下的相对介电常数和介质损耗分别为7.92和1.2×10-4.

  12. ZrO2对高硼硅玻璃高温粘度和表面张力的影响%Effect of ZrO2 on Viscosity and Surface Tension of Borosilicate Glass

    Institute of Scientific and Technical Information of China (English)

    刘尧龙; 陆平; 程金树

    2016-01-01

    Due to the high melting temperature ,borosilicate glass erode refractory strongly .ZrO2 dissolved into the glass change viscosity and surface of mother glass , which also bring about many and various product defects .In this paper , a small amount of ZrO 2 were introduced into the mother glass .High temperature viscosity was tested by the rotating method and high temperature surface tension was tested by the sessile drop method .The results indicate that viscosity of the glass above 1530 ℃almost no change and viscosity of the glass below 1530 ℃ greatly increase with increasing ZrO 2 content .At same time , surface tension is increasing mono-tonically .Surface tension reduce as the temperature increases .%高硼硅玻璃由于熔化温度高,对耐火材料侵蚀严重,ZrO2溶解到玻璃中后使其高温粘度和表面张力发生变化,是产生玻璃缺陷的重要原因之一。通过在母体玻璃中引入少量ZrO2,采用旋转粘度法测试玻璃的高温粘度,采用静滴法测试玻璃的高温表面张力。结果表明,随着含量的增加,ZrO2对玻璃在1530℃以上的粘度影响不大,但可使1530℃以下的粘度有较大提高。玻璃的高温表面张力随着ZrO2含量的增加单调递增,随着温度的升高而降低。

  13. Structural and crystallisation study of a rare earth alumino borosilicate glass designed for nuclear waste confinement; Etude de la structure et du comportement en cristallisation d'un verre nucleaire d'aluminoborosilicate de terre rare

    Energy Technology Data Exchange (ETDEWEB)

    Quintas, A

    2007-09-15

    This work is devoted to the study of a rare earth alumino borosilicate glass, which molar composition is 61,81 SiO{sub 2} - 3,05 Al{sub 2}O{sub 3} - 8,94 B{sub 2}O{sub 3} - 14,41 Na{sub 2}O - 6,33 CaO - 1,90 ZrO{sub 2} - 3,56 Nd{sub 2}O{sub 3}, and envisaged for the immobilization of nuclear wastes originating from the reprocessing of high discharge burn up spent fuel. From a structural viewpoint, we investigated the role of the modifier cations on the arrangement of the glass network through different modifications of the glass composition: variation of the Na/Ca ratio and modification of the nature of the alkali and alkaline earth cations. The NMR and Raman spectroscopic techniques were useful to determine the distribution of modifier cations among the glass network and also to cast light on the competition phenomena occurring between alkali and alkaline earth cations for charge compensation of [AlO{sub 4}]{sup -} and [BO{sub 4}]{sup -} species. The neodymium local environment could be probed by optical absorption and EXAFS spectroscopies which enabled to better understand the insertion mode of Nd{sup 3+} ions among the silicate domains of the glass network. Concerning the crystallization behavior we were interested in how the glass composition may influence the crystallization processes and especially the formation of the apatite phase of composition Ca{sub 2}Nd{sub 8}(SiO{sub 4}){sub 6}O{sub 2}. In particular, this work underlined the important role of both alkaline earth and rare earth cations on the crystallization of the apatite phase. (author)

  14. Formation Mechanism of Multilayered Structure on Surface of Bioactive Borosilicate Glass%硼硅酸盐生物玻璃表面多层结构的形成机理

    Institute of Scientific and Technical Information of China (English)

    姚爱华; 林健; 段祥; 黄文旵; Rahaman Mohamed N

    2008-01-01

    A conversion process of a bioactive borosilieate glass to a muhilayered structure in aqueous phosphate solution was described. Microstructure, morphology and composition of the reaction product were studied using XRD,SEM and EDS analysis. It was shown that a muhilayered structure, consisting of alternating hydroxyapatite(HA) and amorphous SiO2 layers, was formed on the surface of the borosilicate glass. The formation mechanism of the muhilayered microstructure was also suggested. Compared with previous work, it was indicated that conversion kinetics and mierostructure development of conversion products mainly depended on the composition of the bioactive glass and the concentration of phosphate solution.%描述了硼硅酸盐生物活性玻璃在体外含磷溶液中的转变过程,并采用XRD、SEM和EDS对反应产物的微观结构、形貌和成分进行了分析.结果显示,产物为多层结构,由羟基磷灰石和无定型SiO2层交替排列而成.此外,提出了一个定性模型来解释层状结构的形成机制.研究证实,反应动力学及反应产物的微观结构主要取决于生物活性玻璃的成分和含磷溶液的浓度.

  15. Effect of Zn- and Ca-oxides on the structure and chemical durability of simulant alkali borosilicate glasses for immobilisation of UK high level wastes

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hua, E-mail: nzhangh@aliyun.com [Immobilisation Science Laboratory, Department of Materials Science and Engineering, The University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield S1 3JD (United Kingdom); China Institute of Atomic Energy, P.O. Box 275-93, 102413 Beijing (China); Corkhill, Claire L.; Heath, Paul G.; Hand, Russell J.; Stennett, Martin C. [Immobilisation Science Laboratory, Department of Materials Science and Engineering, The University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield S1 3JD (United Kingdom); Hyatt, Neil C., E-mail: n.c.hyatt@sheffield.ac.uk [Immobilisation Science Laboratory, Department of Materials Science and Engineering, The University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield S1 3JD (United Kingdom)

    2015-07-15

    Highlights: • Spinel crystallization incorporates ZnO from base glass, displacing Mg and Ni. • Raman spectroscopy demonstrates significant impact on glass structure by addition of ZnO to base glass. • Addition of ZnO reduces glass dissolution rate at early time periods (up to 28 days). - Abstract: Compositional modification of United Kingdom high level nuclear waste (HLW) glasses was investigated with the aim of understanding the impact of adopting a ZnO/CaO modified base glass on the vitrified product phase assemblage, glass structure, processing characteristics and dissolution kinetics. Crystalline spinel phases were identified in the vitrified products derived from the Na{sub 2}O/Li{sub 2}O and the ZnO/CaO modified base glass compositions; the volume fraction of the spinel crystallites increased with increasing waste loading from 15 to 20 wt%. The spinel composition was influenced by the base glass components; in the vitrified product obtained with the ZnO/CaO modified base glass, the spinel phase contained a greater proportion of Zn, with a nominal composition of (Zn{sub 0.60}Ni{sub 0.20}Mg{sub 0.20})(Cr{sub 1.37}Fe{sub 0.63})O{sub 4}. The addition of ZnO and CaO to the base glass was also found to significantly alter the glass structure, with changes identified in both borate and silicate glass networks using Raman spectroscopy. In particular, these glasses were characterised by a significantly higher Q{sup 3} species, which we attribute to Si–O–Zn linkages; addition of ZnO and CaO to the glass composition therefore enhanced glass network polymerisation. The increase in network polymerisation, and the presence of spinel crystallites, were found to increase the glass viscosity of the ZnO/CaO modified base glass; however, the viscosities were within the accepted range for nuclear waste glass processing. The ZnO/CaO modified glass compositions were observed to be significantly more durable than the Na{sub 2}O/Li{sub 2}O base glass up to 28 days, due to

  16. Influence of P{sub 2}O{sub 5} and Al{sub 2}O{sub 3} content on the structure of erbium-doped borosilicate glasses and on their physical, thermal, optical and luminescence properties

    Energy Technology Data Exchange (ETDEWEB)

    Bourhis, Kevin, E-mail: k.bourhis@argolight.com [Politecnico di Torino, DISAT, Istituto di Ingegneria e Fisica dei Materiali, Corso Duca degli Abruzzi 24, I-10129 Torino (Italy); Massera, Jonathan [Process Chemistry Centre, Åbo Akademi University, Biskopsgatan 8, FI-20500 Turku (Finland); Petit, Laeticia; Ihalainen, Heikki [nLIGHT Corporation, Sorronrinne 9, FI-08500 Lohja (Finland); Fargues, Alexandre; Cardinal, Thierry [CNRS, Université de Bordeaux, ISM, 351Cours de la Libération, F-33405 Talence (France); Hupa, Leena; Hupa, Mikko [Process Chemistry Centre, Åbo Akademi University, Biskopsgatan 8, FI-20500 Turku (Finland); Dussauze, Marc; Rodriguez, Vincent [CNRS, Université de Bordeaux, ICMCB, 87 Avenue du Dr Schweitzer, F-33608 Pessac (France); Boussard-Plédel, Catherine; Bureau, Bruno; Roiland, Claire [Equipe Verres et Céramiques, UMR-CNRS 6226, Inst. des Sciences chimiques de Rennes, Université de Rennes 1, 35042 Rennes CEDEX (France); Ferraris, Monica [Politecnico di Torino, DISAT, Istituto di Ingegneria e Fisica dei Materiali, Corso Duca degli Abruzzi 24, I-10129 Torino (Italy)

    2015-03-15

    Highlights: • Reorganization of the glass structure induced by the addition of P{sub 2}O{sub 5} or Al{sub 2}O{sub 3}. • Emission properties related to the presence of P or Al in the Er{sup 3+} coordination shell. • Declustering observed upon addition of P{sub 2}O{sub 5}. • No declustering upon addition of Al{sub 2}O{sub 3}. - Abstract: The effect of P{sub 2}O{sub 5} and/or Al{sub 2}O{sub 3} addition in Er-doped borosilicate glasses on the physical, thermal, optical, and luminescence properties is investigated. The changes in these glass properties are related to the glass structure modifications induced by the addition of P{sub 2}O{sub 5} and/or Al{sub 2}O{sub 3}, which were probed by FTIR, {sup 11}B MAS NMR and X-ray photoelectron spectroscopies. Variations of the polymerization degree of the silicate tetrahedra and modifications in the {sup [3]}B/{sup [4]}B ratio are explained by a charge compensation mechanism due to the formation of AlO{sub 4}, PO{sub 4} groups and the formation of Al-O-P linkages in the glass network. From the absorption and luminescence properties of the Er{sup 3+} ions at 980 nm and 1530 nm, declustering is suspected for the highest P{sub 2}O{sub 5} concentrations while for the highest Al{sub 2}O{sub 3} concentrations no declustering is observed.

  17. Modifications induced in the structural and optical properties of bismuth sodium borosilicate glass thin films by 120 MeV Ag{sup 7+} ions

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, Ravneet, E-mail: ravneet_383@yahoo.com [Department of Physics, Guru Nanak Dev University, Amritsar 143 005 (India); Singh, Surinder [Department of Physics, Guru Nanak Dev University, Amritsar 143 005 (India); Pandey, O.P. [School of Physics and Materials Science, Thapar University, Patiala 147 004 (India)

    2013-06-15

    The composition of the glass is Bi{sub 2}O{sub 3} (20%)–Na{sub 2}O (15%)–B{sub 2}O{sub 3} (50%)–SiO{sub 2} (15%) was prepared by conventional melt quench method. To study the effect of heavy ion irradiation on the glass network and structural units, thin films of the glass have been prepared by electron beam gun evaporation. The prepared films are irradiated using 120 MeV Ag{sup 7+} ions in the fluence range of 1 × 10{sup 12}–3 × 10{sup 13} ions cm{sup −2}. The optical and structural properties were investigated using UV–visible absorption spectroscopy and Fourier Transform Infrared (FTIR) spectroscopic techniques. A significant decrease in the band gap is observed after irradiation which is indicative of the fact that radiation has caused compaction in the glass structure.

  18. Why neutron guides may end up breaking down? Some results on the macroscopic behaviour of alkali-borosilicate glass support plates under neutron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Boffy, R.; Kreuz, M. [Institut Laue-Langevin, 71 avenue des Martyrs, CS 20156, F-38042 Grenoble Cedex 9 (France); Beaucour, J., E-mail: beaucour@ill.fr [Institut Laue-Langevin, 71 avenue des Martyrs, CS 20156, F-38042 Grenoble Cedex 9 (France); Köster, U. [Institut Laue-Langevin, 71 avenue des Martyrs, CS 20156, F-38042 Grenoble Cedex 9 (France); Bermejo, F.J. [Instituto de Estructura de la Materia, Consejo Superior de Investigaciones Cientificas, Serrano 123, E-20886 Madrid (Spain)

    2015-09-01

    In this paper we report on a first part of a study on the mechanisms leading to brittle fracture in neutron guides made of glass as structural element. Such devices are widely used to deliver thermal and cold neutron beams to experimental lines in most large neutron research facilities. We present results on macroscopic properties of samples of guide glass substrates which are subjected to neutron irradiation at relatively large fluences. The results show a striking dependence of some of the macroscopic properties such as density, shape or surface curvature upon the specific chemical composition of a given glass. The relevance of the present findings for the installation of either replacement guides at the existing facilities or for the deployment of instruments for ongoing projects such as the European Spallation Source is briefly discussed.

  19. 硼硅酸盐玻璃薄片CO2激光反向弯曲研究%Study on Borosilicate Glass Sheet Reverse Bending with CO2 Laser

    Institute of Scientific and Technical Information of China (English)

    吴东江; 牛方勇; 张强; 郭东明

    2009-01-01

    Experiments of borosilicate glass sheet reverse bending by CO2 CW- laser were successfully presented, and suitable processing parameters of reverse bending were given for specimen with thickness of 150μm. The influences of scanning number and specimen width on bending results were investigated, and then experimental phenomenon was analyzed by comparing with the forward bending. In view of the suitable processing parameters and experimental results, the buckling mechanism can be sited as the laser forming mechanism responsible for reverse bending of glass sheet. The reverse bending progress increases the flexibility of laser forming and provides a new way in machining for intricate parts.%利用CO2连续激光对厚度为150μm的硼硅酸盐玻璃薄片进行了反向弯曲试验,得到了适合反向弯曲的激光加工工艺参数.研究了激光扫描次数及玻璃样品宽度对反向弯曲效果的影响,并就相关试验现象结合正向弯曲成形进行了比较分析.综合考虑实现反向弯曲成形的工艺参数及试验结果,初步确定激光加工玻璃薄片实现反向弯曲的机理为翘曲机理.反向弯曲技术进一步增加了激光弯曲成形的柔性化,为复杂零件的加工提供了新的解决途径.

  20. Erbium-doped borosilicate glasses containing various amounts of P{sub 2}O{sub 5} and Al{sub 2}O{sub 3}: Influence of the silica content on the structure and thermal, physical, optical and luminescence properties

    Energy Technology Data Exchange (ETDEWEB)

    Bourhis, Kevin [Politecnico di Torino, DISAT, Istituto di Ingegneria e Fisica dei Materiali, Corso Duca degli Abruzzi 24, I-10129 Torino (Italy); Massera, Jonathan [Department of Electronics and Communications Engineering, Tampere University of Technology, Korkeakoulunkatu 3, FI-33720 Tampere (Finland); BioMediTech, Tampere (Finland); Petit, Laeticia, E-mail: laeticia.petit@nlight.net [Process Chemistry Centre, Åbo Akademi University, Biskopsgatan 8, FI-20500 Turku (Finland); nLIGHT Corporation, Sorronrinne 9, FI-08500 Lohja (Finland); Koponen, Joona [nLIGHT Corporation, Sorronrinne 9, FI-08500 Lohja (Finland); Fargues, Alexandre; Cardinal, Thierry [CNRS, Université de Bordeaux, ISM, 351 Cours de la Libération, F-33405 Talence (France); Hupa, Leena; Hupa, Mikko [Process Chemistry Centre, Åbo Akademi University, Biskopsgatan 8, FI-20500 Turku (Finland); Dussauze, Marc; Rodriguez, Vincent [CNRS, Université de Bordeaux, ICMCB, 87 Avenue du Dr Schweitzer, F-33608 Pessac (France); Ferraris, Monica [Politecnico di Torino, DISAT, Istituto di Ingegneria e Fisica dei Materiali, Corso Duca degli Abruzzi 24, I-10129 Torino (Italy)

    2015-10-15

    Highlights: • Er{sup 3+} doped borosilicate glasses were processed with different compositions and characterizations. • An increase in the SiO{sub 2} content leads to a silicate-rich environment around the Er{sup 3+} site. • An increase in the SiO{sub 2} content decreases the Er{sup 3+} absorption cross-section at 980 nm. • Glasses with 60 mol% of SiO{sub 2} exhibit a stronger emission intensity at 1530 nm than glasses with x = 50. • Highest 1.5 μm emission intensity was achieved for the Al and P containing glass with 60 mol% of SiO{sub 2}. - Abstract: The influence of the silica content on several properties of Er-doped borosilicate glasses in the presence of various amounts of P{sub 2}O{sub 5} and Al{sub 2}O{sub 3} has been investigated. The introduction of P{sub 2}O{sub 5} and/or Al{sub 2}O{sub 3} are responsible for structural modifications in the glass network through a charge-compensation mechanism related to the formation of negatively-charged PO{sub 4} and AlO{sub 4} groups or through the formation of AlPO{sub 4}-like structural units. In this paper, we show that an increase in the SiO{sub 2} content leads to a silicate-rich environment around the Er{sup 3+} site, resulting in an increased dependence of the Er{sup 3+} ions optical and luminescence properties on the P{sub 2}O{sub 5} and/or Al{sub 2}O{sub 3} concentration. The highest emission intensity at 1.5 μm was achieved for the glass with an equal proportion of P and Al in the glass system with 60 mol% of SiO{sub 2}.

  1. 涂敷含硼硅玻璃SiC涂层的C/SiC复合材料空气氧化行为%Oxidation behaviors of C/SiC composites coated with SiC coatings containing borosilicate glass

    Institute of Scientific and Technical Information of China (English)

    曹素; 刘永胜; 左新章; 张立同; 成来飞

    2011-01-01

    以2D C/SiC复合材料为基底,采用聚合物裂解工艺(Polymer plyen)制备了含硼硅玻璃SiC自愈合涂层.利用扫描电镜对含硼硅玻璃SiC涂层的2D C/SiC复合材料氧化前后的微结构形貌进行了分析.研究了含硼硅玻璃SiC涂层的C/SiC复合材料在静态空气中700℃、1000℃和1200℃下的氧化行为,并分析了涂层层数对C/SiC复合材料氧化行为的影响.结果表明:含硼硅玻璃SiC涂层在该温度下形成的玻璃相可以较好地封填表面缺陷(裂纹和孔洞);并且随温度升高及涂层层数增加,试样在氧化过程中质量减少率降低,氧化后的强度保持率提高.%SiC self-healing coatings containing borosilicate glass were prepared by polymer plyen on the 2D C/SiC composites. The microstructure morphologies of the 2D C/SiC composites with SiC coating containing borosilicate glass before and after oxidation were analyzed by SEM. The oxidation behaviors of the C/SiC composites with SiC coating containing borosilicate glass were studied at 700 ℃, 1000 ℃ and 1200 ℃ in static air and the oxidation behaviors resulted by different layers were analyzed. The results show that the glass phase produced by the SiC coating containing borosilicate glass can seal the defections (cracks and pores) existed in the coating, and with increasing the temperature and number of the coating layers, the C/SiC composites have lower mass loss during the oxidation and higher strength retention after oxidized.

  2. Feasibility and tailoring of bioactive glass-ceramic scaffolds with gradient of porosity for bone grafting.

    Science.gov (United States)

    Vitale-Brovarone, Chiara; Baino, Francesco; Verné, Enrica

    2010-05-01

    The aim of this research study is the preparation and characterization of graded glass-ceramic scaffolds that are able to mimic the structure of the natural bone tissue, formed by cortical and cancellous bone. The material chosen for the scaffolds preparation is a glass belonging to the system SiO( 2)-P(2)O(5)-CaO-MgO-Na( 2)O-K(2)O (CEL2). The glass was synthesized by a conventional melting-quenching route, ground, and sieved to obtain powders of specific size. The scaffolds were fabricated using different methods: polyethylene burn-off, sponge replication, a glazing-like technique, and combinations of these methods. The scaffolds were characterized through morphological observations, density measurements, volumetric shrinkage, mechanical tests, and in vitro bioactivity tests. The features of the scaffolds prepared using the different methods were compared in terms of morphological structure, pores content, and mechanical strength. The proposed scaffolds effectively mimic the cancellous/cortical bone system in terms of structure, porosity, and mechanical strength, and they exhibit a highly bioactive behavior. Therefore, these graded grafts have a great potential for biomedical applications and can be successfully proposed for the substitution of load-bearing bone portions.

  3. Novel systems for tailored neurotrophic factor release based on hydrogel and resorbable glass hollow fibers.

    Science.gov (United States)

    Novajra, G; Tonda-Turo, C; Vitale-Brovarone, C; Ciardelli, G; Geuna, S; Raimondo, S

    2014-03-01

    A novel system for the release of neurotrophic factor into a nerve guidance channel (NGC) based on resorbable phosphate glass hollow fibers (50P2O5-30CaO-9Na2O-3SiO2-3MgO-2.5K2O-2.5TiO2 mol%) in combination with a genipin-crosslinked agar/gelatin hydrogel (A/G_GP) is proposed. No negative effect on the growth of neonatal olfactory bulb ensheathing cell line (NOBEC) as well as on the expression of pro- and anti-apoptotic proteins was measured in vitro in the presence of fiber dissolution products in the culture medium. For the release studies, fluorescein isothiocyanate-dextran (FD-20), taken as growth factor model molecule, was solubilized in different media and introduced into the fiber lumen exploiting the capillary action. The fibers were filled with i) FD-20/phosphate buffered saline (PBS) solution, ii) FD-20/hydrogel solution before gelation and iii) hydrogel before gelation, subsequently lyophilized and then filled with the FD-20/PBS solution. The different strategies used for the loading of the FD-20 into the fibers resulted in different release kinetics. A slower release was observed with the use of A/G_GP hydrogel. At last, poly(ε-caprolactone) (PCL) nerve guides containing the hollow fibers and the hydrogel have been fabricated.

  4. Ge-As-S硫系玻璃的结构与性能调控∗%Tailoring structure and prop erty of Ge-As-S chalcogenide glass

    Institute of Scientific and Technical Information of China (English)

    杨艳; 陈云翔; 刘永华; 芮扬; 曹烽燕; 杨安平; 祖成奎; 杨志勇

    2016-01-01

    Chalcogenide glass has been considered to be a promising optical material for infrared (IR) transmission and non-linear optics because of its favorable physical properties such as wide IR transparent windows, high linear and nonlinear refractive indices, and tunable photosensitivity. In many optical designs and practical applications, the refractive index (n) and optical bandgap (Eg) are two important parameters. Aiming to evaluate the composition dependence of the n and Eg in Ge-As-S chalcogenide glasses, a series of glasses with different stoichiometric characteristics are synthesized in quartz tubes under vacuum by the melt quenching technique. The structure, n and Eg of the glass are investigated by Raman spectroscopy, ellipsometry, and diffused reflectance spectroscopy, respectively. To eliminate thermal effects on the measured Raman spectra, the data are corrected by the Bose-Einstein thermal factor. Raman spectrum analyses indicate that Ge-As-S glass has a continuous network structure with interconnected [GeS4] tetrahedra and [AsS3] pyramids forming the backbone. When S amount is excess, S chains or S8 rings emerge. When S amount is deficient, As4S4/As4S3 molecules are formed, and even a large number of As-As/Ge-Ge homopolar bonds appear in the structure. The n values at different wavelengths are obtained by fitting the ellipsometry data with the Sellmeier dispersion model. The values of molar refractivity (Ri) of Ge, As and S elements are evaluated by using the measured n and density (d) of the investigated glass. The optimal values of Ri at 2–10 µm for each element are RGe = 9.83–10.42 cm3/mol, RAs = 11.72–11.87 cm3/mol, and RS = 7.78–7.86 cm3/mol, respectively; and the values decrease with increasing wavelength. The n of Ge-As-S glass is well quantitatively correlated to the d and the Ri of constituent elements, so that its value can be predicted or tailored within 1%deviation. A method to determine reliable Eg of a glass is proposed based on

  5. Characterisation of the thermoluminescence (TL) properties of tailor-made Ge-doped silica glass fibre for applications in medical radiation therapy dosimetry

    Science.gov (United States)

    Zahaimi, N. A.; Zin, H.; Mahdiraji, G. A.; Rahman, A. L. Abdul; Bradley, D. A.; Rahman, A. T. Abdul

    2014-11-01

    We have investigated the characterisation of new fabricated material Ge doped silica glass thermoluminescence TL dosimeter (Photonic Research Centre, University of Malaya) for medical radiation dosimetry at therapy energy. Previously, the dosimeter has been studied to provide ideal dosimetry system, suitable to ensure an accurate delivery of radiation doses to tumour tissue while minimising the amount of radiation administrated to healthy tissue. Both energies of photon and electron were used in this experiment for a dose range of 1 to 5 Gy. The various sizes of core diameter Ge doped silica glass (120, 241, 362, 483 and 604 μm) were exposed by using linear accelerator at Pantai Medical Centre. For both energies, the optical fibres were found to produce a flat response to a fixed photon and electron doses to within 4% (S.D) of the mean of the TL distribution. In terms of dose response, the fibres provide linear response over the range investigated, from a fraction of 1-5 Gy. The finding shows 120 μm fibres have 1.82 greater dose response than 604 pm fibres irradiated at 6 MV photon with a fixed dose of 3 Gy. While for electron energy 12 MeV, the response shows 120 μm fibres have 1.58 greater dose response compared to 604 μm fibres. The good responses are suitable to make these tailor-made doped silica fibres a promising TL material for use as a dosimetric system in medical radiation therapy.

  6. Modelling the local atomic structure of molybdenum in nuclear waste glasses with ab initio molecular dynamics simulations.

    Science.gov (United States)

    Konstantinou, Konstantinos; Sushko, Peter V; Duffy, Dorothy M

    2016-09-21

    The nature of chemical bonding of molybdenum in high level nuclear waste glasses has been elucidated by ab initio molecular dynamics simulations. Two compositions, (SiO2)57.5-(B2O3)10-(Na2O)15-(CaO)15-(MoO3)2.5 and (SiO2)57.3-(B2O3)20-(Na2O)6.8-(Li2O)13.4-(MoO3)2.5, were considered in order to investigate the effect of ionic and covalent components on the glass structure and the formation of the crystallisation precursors (Na2MoO4 and CaMoO4). The coordination environments of Mo cations and the corresponding bond lengths calculated from our model are in excellent agreement with experimental observations. The analysis of the first coordination shell reveals two different types of molybdenum host matrix bonds in the lithium sodium borosilicate glass. Based on the structural data and the bond valence model, we demonstrate that the Mo cation can be found in a redox state and the molybdate tetrahedron can be connected with the borosilicate network in a way that inhibits the formation of crystalline molybdates. These results significantly extend our understanding of bonding in Mo-containing nuclear waste glasses and demonstrate that tailoring the glass composition to specific heavy metal constituents can facilitate incorporation of heavy metals at high concentrations.

  7. [INVITED] Tailoring the morphology of photowritten buried waveguides by helical trajectory in As2S3 glass

    Science.gov (United States)

    Caulier, Ophélie; Masselin, Pascal; Bychkov, Eugène; Coq, David Le

    2016-04-01

    This paper deals with the control of the refractive index variation (Δn) profile induced by femtosecond laser irradiation in the bulk of As2S3 glass. The writing technique consists of an original laser inscription based on a helical translation of the sample parallel to the laser beam. Instead of inscribing the core of the waveguide as usually performed, the laser beam is used to induce a negative refractive index variation and consequently to write the cladding of the waveguide. However, it should be noticed that the matter displacement resulting from local heating leads to a densification at the center of the helix which induces a positive Δn relatively to the matrix. Therefore, the structure of Δn is complex, being composed of a positive core surrounded by a negative cladding. The influence of different parameters on the Δn profiles such as the sample translation velocity, the pitch and the radius of the helical displacement, and the pulse energy are analysed. This study demonstrates that both Δn and its diameter can be varied in a wide range of values and picked independently, allowing the design of single or multimode buried infrared waveguide.

  8. Ultra-lightweight borosilicate gas-fusion mirror for cryogenic testing

    Science.gov (United States)

    Voevodsky, Michael; Wortley, Richard W.

    2003-12-01

    Hextek Corporation (Hextek) is under contract to fabricate an ultra-lightweight borosilicate mirror using its Gas-Fusion technology for cryogenic testing at NASA MSFC. Not widely known, borosilicate glass has a CTE approaching zero at the proposed cryogenic operating temperature of 30-35 degrees Kelvin. The mirror specifications are for a 250 mm diameter closed-back honeycomb sandwich mirror, slumped to a 2500 mm ROC, and a target areal density of 15 kg/m2. The paper/presentation will review the proposal objectives, technical data, and the prototype mirror. Expected significance to NASA include dramatic schedule enhancement and cost reduction for ultra-lightweight mirrors in sizes up to and beyond 1 meter for operation at cryogenic temperatures.

  9. Glasses

    DEFF Research Database (Denmark)

    Dyre, Jeppe

    2004-01-01

    The temperature dependence of the viscosity of most glassforming liquids is known to depart significantly from the classical Arrhenius behaviour of simple fluids. The discovery of an unexpected correlation between the extent of this departure and the Poisson ratio of the resulting glass could lead...... to new understanding of glass ageing and viscous liquid dynamics....

  10. Volume changes in glass induced by an electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Gavenda, Tadeáš, E-mail: gavendat@vscht.cz [Department of Glass and Ceramics, Institute of Chemical Technology, Technická 5, CZ-166 28 Prague (Czech Republic); Gedeon, Ondrej [Department of Glass and Ceramics, Institute of Chemical Technology, Technická 5, CZ-166 28 Prague (Czech Republic); Jurek, Karel [Institute of Physics, Academy of the Czech Republic, Na Slovance 2, CZ-182 21 Prague (Czech Republic)

    2014-03-01

    Three glasses (float, borosilicate float and Schott D263 glasses) were irradiated by 50 keV electron beams with doses within the range of 0.21–318.5 kC/m{sup 2}. Volume changes induced by electron bombarding were monitored by means of Atomic Force Microscopy. Incubation doses, related to mobility of alkali ions, were measured. Low doses showed compaction of all glasses while higher doses revealed volume inflation, except for borosilicate float glass. Both surfaces of float glass were irradiated and significant differences between them were found.

  11. Volume changes in glass induced by an electron beam

    Science.gov (United States)

    Gavenda, Tadeáš; Gedeon, Ondrej; Jurek, Karel

    2014-03-01

    Three glasses (float, borosilicate float and Schott D263 glasses) were irradiated by 50 keV electron beams with doses within the range of 0.21-318.5 kC/m2. Volume changes induced by electron bombarding were monitored by means of Atomic Force Microscopy. Incubation doses, related to mobility of alkali ions, were measured. Low doses showed compaction of all glasses while higher doses revealed volume inflation, except for borosilicate float glass. Both surfaces of float glass were irradiated and significant differences between them were found.

  12. Penetration Physics of Armor Glass

    Science.gov (United States)

    2009-11-30

    Penetration Response of Borosilicate Glass during Short Rod Impact”, Proc. 23rd Int. Symp. Ballistics, 2, 1251-1258, Graficas Couche, Madrid, Spain (2007...glass”, Proc. 23rd Int. Symp. Ballistics, 2, 1049-1056, Graficas Couche, Madrid, Spain (2007). 8D. R. Curran, “Comparison of Mesomechanical and

  13. Near net-shape fabrication of hydroxyapatite glass composites

    NARCIS (Netherlands)

    Zhu, Q.; With, G. de; Dortmans, L.J.M.G.; Feenstra, F.

    2004-01-01

    Near net-shape fabrication of hydroxyapatite (HA) glass composites has been attempted by infiltrating a glass into porous HA performs. Main efforts were put to develop glasses that are chemically compatible with HA at elevated temperatures. After extensive investigations in the phosphate and borosil

  14. Tailoring the refractive index of Ge-S based glass for 3D embedded waveguides operating in the mid-IR region.

    Science.gov (United States)

    Bérubé, J P; Messaddeq, S H; Bernier, M; Skripachev, I; Messaddeq, Y; Vallée, R

    2014-10-20

    The photosensitivity of GeS(x) binary glasses in response to irradiation to femtosecond pulses at 800 nm is investigated. Samples with three different molecular compositions were irradiated under different exposure conditions. The material response to laser exposure was characterized by both refractometry and micro-Raman spectroscopy. It is shown that the relative content of sulfur in the glass matrix influences the photo-induced refractive index modification. At low sulfur content, both positive and negative index changes can be obtained while at high sulfur content, only a positive index change can be reached. These changes were correlated with variations in the Raman response of exposed glass which were interpreted in terms of structural modifications of the glass network. Under optimized exposure conditions, waveguides with positive index changes of up to 7.8 x 10(-3)and a controllable diameter from 14 to 25 μm can be obtained. Direct inscription of low insertion losses (IL = 3.1 - 3.9 dB) waveguides is demonstrated in a sample characterized by a S/Ge ratio of 4. The current results open a pathway towards the use of Ge-S binary glasses for the fabrication of integrated mid-infrared photonic components.

  15. Glass viscosity calculation based on a global statistical modelling approach

    Energy Technology Data Exchange (ETDEWEB)

    Fluegel, Alex

    2007-02-01

    A global statistical glass viscosity model was developed for predicting the complete viscosity curve, based on more than 2200 composition-property data of silicate glasses from the scientific literature, including soda-lime-silica container and float glasses, TV panel glasses, borosilicate fiber wool and E type glasses, low expansion borosilicate glasses, glasses for nuclear waste vitrification, lead crystal glasses, binary alkali silicates, and various further compositions from over half a century. It is shown that within a measurement series from a specific laboratory the reported viscosity values are often over-estimated at higher temperatures due to alkali and boron oxide evaporation during the measurement and glass preparation, including data by Lakatos et al. (1972) and the recently published High temperature glass melt property database for process modeling by Seward et al. (2005). Similarly, in the glass transition range many experimental data of borosilicate glasses are reported too high due to phase separation effects. The developed global model corrects those errors. The model standard error was 9-17°C, with R^2 = 0.985-0.989. The prediction 95% confidence interval for glass in mass production largely depends on the glass composition of interest, the composition uncertainty, and the viscosity level. New insights in the mixed-alkali effect are provided.

  16. A space imaging concept based on a 4m structured spun-cast borosilicate monolithic primary mirror

    Science.gov (United States)

    West, S. C.; Bailey, S. H.; Bauman, S.; Cuerden, B.; Granger, Z.; Olbert, B. H.

    2010-07-01

    Lockheed Martin Corporation (LMC) tasked The University of Arizona Steward Observatory (UASO) to conduct an engineering study to examine the feasibility of creating a 4m space telescope based on mature borosilicate technology developed at the UASO for ground-based telescopes. UASO has completed this study and concluded that existing launch vehicles can deliver a 4m monolithic telescope system to a 500 km circular orbit and provide reliable imagery at NIIRS 7-8. An analysis of such an imager based on a lightweight, high-performance, structured 4m primary mirror cast from borosilicate glass is described. The relatively high CTE of this glass is used to advantage by maintaining mirror shape quality with a thermal figuring method. Placed in a 290 K thermal shroud (similar to the Hubble Space Telescope), the orbit averaged figure surface error is 6nm rms when earth-looking. Space-looking optical performance shows that a similar thermal conditioning scheme combined with a 270 K shroud achieves primary mirror distortion of 10 nm rms surface. Analysis shows that a 3-point bipod mount will provide launch survivability with ample margin. The primary mirror naturally maintains its shape at 1g allowing excellent end-to-end pre-launch testing with e.g. the LOTIS 6.5m Collimator. The telescope includes simple systems to measure and correct mirror shape and alignment errors incorporating technologies already proven on the LOTIS Collimator. We have sketched a notional earth-looking 4m telescope concept combined with a wide field TMA concept into a DELTA IV or ATLAS 552 EELV fairing. We have combined an initial analysis of launch and space performance of a special light-weighted honeycomb borosilicate mirror (areal density 95 kg/m2) with public domain information on the existing launch vehicles.

  17. Plasma-mediated inactivation of Pseudomonas aeruginosa biofilms grown on borosilicate surfaces under continuous culture system.

    Science.gov (United States)

    Vandervoort, Kurt G; Brelles-Mariño, Graciela

    2014-01-01

    Biofilms are microbial communities attached to a surface and embedded in a matrix composed of exopolysaccharides and excreted nucleic acids. Bacterial biofilms are responsible for undesirable effects such as disease, prostheses colonization, biofouling, equipment damage, and pipe plugging. Biofilms are also more resilient than free-living cells to regular sterilization methods and therefore it is indispensable to develop better ways to control and remove them. The use of gas discharge plasmas is a good alternative since plasmas contain a mixture of reactive agents well-known for their decontamination potential against free microorganisms. We have previously reported that Pseudomonas aeruginosa biofilms were inactivated after a 1-min plasma exposure. We determined that the adhesiveness and the thickness of Pseudomonas biofilms grown on borosilicate were reduced. We also reported sequential morphological changes and loss of viability upon plasma treatment. However, the studies were carried out in batch cultures. The use of a continuous culture results in a more homogenous environment ensuring reproducible biofilm growth. The aim of this work was to study plasma-mediated inactivation of P. aeruginosa biofilms grown on borosilicate in a continuous culture system. In this paper we show that biofilms grown on glass under continuous culture can be inactivated by using gas discharge plasma. Both biofilm architecture and cell culturability are impacted by the plasma treatment. The inactivation kinetics is similar to previously described ones and cells go through sequential changes ranging from minimal modification without loss of viability at short plasma exposure times, to major structure and viability loss at longer exposure times. We report that changes in biofilm structure leading to the loss of culturability and viability are related to a decrease of the biofilm matrix adhesiveness. To our knowledge, there has been no attempt to evaluate the inactivation

  18. Plasma-mediated inactivation of Pseudomonas aeruginosa biofilms grown on borosilicate surfaces under continuous culture system.

    Directory of Open Access Journals (Sweden)

    Kurt G Vandervoort

    Full Text Available Biofilms are microbial communities attached to a surface and embedded in a matrix composed of exopolysaccharides and excreted nucleic acids. Bacterial biofilms are responsible for undesirable effects such as disease, prostheses colonization, biofouling, equipment damage, and pipe plugging. Biofilms are also more resilient than free-living cells to regular sterilization methods and therefore it is indispensable to develop better ways to control and remove them. The use of gas discharge plasmas is a good alternative since plasmas contain a mixture of reactive agents well-known for their decontamination potential against free microorganisms. We have previously reported that Pseudomonas aeruginosa biofilms were inactivated after a 1-min plasma exposure. We determined that the adhesiveness and the thickness of Pseudomonas biofilms grown on borosilicate were reduced. We also reported sequential morphological changes and loss of viability upon plasma treatment. However, the studies were carried out in batch cultures. The use of a continuous culture results in a more homogenous environment ensuring reproducible biofilm growth. The aim of this work was to study plasma-mediated inactivation of P. aeruginosa biofilms grown on borosilicate in a continuous culture system. In this paper we show that biofilms grown on glass under continuous culture can be inactivated by using gas discharge plasma. Both biofilm architecture and cell culturability are impacted by the plasma treatment. The inactivation kinetics is similar to previously described ones and cells go through sequential changes ranging from minimal modification without loss of viability at short plasma exposure times, to major structure and viability loss at longer exposure times. We report that changes in biofilm structure leading to the loss of culturability and viability are related to a decrease of the biofilm matrix adhesiveness. To our knowledge, there has been no attempt to evaluate the

  19. Solubility of actinides and surrogates in nuclear glasses; Solubilite des actinides et de leurs simulants dans les verres nucleaires. Limites d'incorporation et comprehension des mecanismes

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, Ch

    2003-07-01

    The nuclear wastes are currently incorporated in borosilicate glass matrices. The resulting glass must be perfectly homogeneous. The work discussed here is a study of actinide (thorium and plutonium) solubility in borosilicate glass, undertaken to assess the extent of actinide solubility in the glass and to understand the mechanisms controlling actinide solubilization. Glass specimens containing; actinide surrogates were used to prepare and optimize the fabrication of radioactive glass samples. These preliminary studies revealed that actinide Surrogates solubility in the glass was enhanced by controlling the processing temperature, the dissolution kinetic of the surrogate precursors, the glass composition and the oxidizing versus reducing conditions. The actinide solubility was investigated in the borosilicate glass. The evolution of thorium solubility in borosilicate glass was determined for temperatures ranging from 1200 deg C to 1400 deg C.Borosilicate glass specimens containing plutonium were fabricated. The experimental result showed that the plutonium solubility limit ranged from 1 to 2.5 wt% PuO{sub 2} at 1200 deg C. A structural approach based on the determination of the local structure around actinides and their surrogates by EXAFS spectroscopy was used to determine their structural role in the glass and the nature of their bonding with the vitreous network. This approach revealed a correlation between the length of these bonds and the solubility of the actinides and their surrogates. (author)

  20. Patch electrode glass composition affects ion channel currents.

    OpenAIRE

    Furman, R E; Tanaka, J C

    1988-01-01

    The influence of patch electrode glass composition on macroscopic IV relations in inside-out patches of the cGMP-activated ion channel from rod photoreceptors was examined for a soda lime glass, a Kovar sealing glass, a borosilicate glass, and several soft lead glasses. In several glasses the shape or magnitude of the currents changed as the concentration of EGTA or EDTA was increased from 200 microM to 10 mM. The changes in IV response suggest that, at low concentrations of chelator, divalen...

  1. Effects of neodymium and gadolinium on weathering resistance of ZnO-B2O3-SiO2 glass

    Institute of Scientific and Technical Information of China (English)

    李雄伟; 李梅; 王觅堂; 柳召刚; 胡艳宏; 田俊虎

    2014-01-01

    The ZnO-B2O3-SiO2 glass doped with Nd2O3 and Gd2O3 was prepared by high temperature melt cooling method. The standard sample of the zinc borosilicate glass was placed in the constant temperature and humidity chamber in order to simulate the atmospheric corrosion process. The surface of the weathered glass was analyzed by scanning electron microscope and energy disper-sive spectrometry and the filtrate was analyzed by inductively coupled plasma-atomic emission spectrometry. The results showed that humidity was the most important factor influencing weathering; the morphology of glass surface of altered layer and the product on the surface was observed; the corroding degree of the zinc borosilicate glass doped with Nd or Gd was significantly lighter than that of the base glass.Adding rare earth Nd or Gd in the zinc borosilicate glass could suppress Na, Zn, Si ion release in weathering.

  2. GLASSES CONTAINING IRON (II III) OXIDES FOR IMMOBILIZATION OF RADIOACTIVE TECHNETIUM

    Energy Technology Data Exchange (ETDEWEB)

    KRUGER AA; HEO J; XU K; CHOI JK; HRMA PR; UM W

    2011-11-07

    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 {approx} 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 {approx}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.

  3. Preparation and the Third-Order Optical Nonlinearities of the Sodium Borosilicate Glass Doped with In2S3 Quantum Dots%In2S3量子点玻璃的制备及其三阶非线性光学性质

    Institute of Scientific and Technical Information of China (English)

    赵海军; 陈兆平; 向卫东; 钟家松; 杨昕宇; 郭玉清; 梁晓娟; 黄海宇; 罗洪艳; 赵秀丽

    2012-01-01

    In2S3 quantum dots glass has been synthesized by both sol-gel and atmosphere control methods in this paper. The microstructures of In2S3 quantum dots in the glass was characterized by means of X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), energy dispersion X-ray spectra (EDX), high-resolution transmission electron microscopy (HRTEM), and selected-area electron diffraction (SAED). Meanwhile, the third-order nonlinear optical properties of the glass were measured in detail by the femtosecond Z-scan technique at a wavelength of 800 nm. The results showed that In2S3 quantum dots had formed in the glass, and the sizes of these In2S3 quantum dots having the tetragonal crystalline structure range from 12 nm to 20 nm, the glass exhibited the excellent third-order nonlinear optical properties, and the third-order nonlinear optical refractive index y, absorption coefficient β and susceptibility x (3) of the glass were determined to be -2.04×l0-18 m2 ·W-1 8.26×l0-12 m·W-1, and 1.61×10"20 m2·V"2, respectively.%本文利用溶胶-凝胶法结合气氛控制合成了含In2S3量子点玻璃.利用X射线粉末衍射仪(XRD),X射线光电子能谱(XPS),透射电子显微镜(TEM),X射线能量色散谱(EDX),高分辨透射电子显微镜(HRTEM)以及选区电子衍射(SAED)对In2S3量子点在玻璃中的微结构进行了表征,同时,利用飞秒Z-scan技术详细地研究了该玻璃在800 nm处的三阶非线性光学性质.结果表明,尺寸分布在12~20 nm之间的In2S3四方晶系纳米晶已经在玻璃中形成,并且,该玻璃展示出了优异的三阶非线性光学性能,其三阶非线性光学折射率γ、吸收系数β和和极化率x(3)分别为-2.04× 10-18 m2·W-1,8.26×10-12 m·W-1,和1.61×10-20 m2·V-2.

  4. ZERODUR TAILORED for cryogenic application

    Science.gov (United States)

    Jedamzik, R.; Westerhoff, T.

    2014-07-01

    ZERODUR® glass ceramic from SCHOTT is known for its very low thermal expansion coefficient (CTE) at room temperature and its excellent CTE homogeneity. It is widely used for ground-based astronomical mirrors but also for satellite applications. Many reference application demonstrate the excellent and long lasting performance of ZERODUR® components in orbit. For space application a low CTE of the mirror material is required at cryogenic temperatures together with a good match of the thermal expansion to the supporting structure material. It is possible to optimize the coefficient of thermal expansion of ZERODUR® for cryogenic applications. This paper reports on measurements of thermal expansion of ZERODUR® down to cryogenic temperatures of 10 K performed by the PTB (Physikalisch Technische Bundesanstallt, Braunschweig, Germany, the national metrology laboratory). The ZERODUR® TAILORED CRYO presented in this paper has a very low coefficient of thermal expansion down to 70 K. The maximum absolute integrated thermal expansion down to 10 K is only about 20 ppm. Mirror blanks made from ZERODUR® TAILORED CRYO can be light weighted to almost 90% with our modern processing technologies. With ZERODUR® TAILORED CRYO, SCHOTT offers the mirror blank material for the next generation of space telescope applications.

  5. Healing of lithographically introduced flaws in glass and glass containing ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Ackler, H.D.

    1992-12-01

    The morphological evolution of cylindrical pores or channels'' and crack-like cavities in glass and glass-containing ceramics at elevated temperatures was studied. The systems studied were: Coming 7056 alkali borosilicate glass, soda-lime glass (microscope slides), a commercially available 96% Al[sub 2]O[sub 3]with [approx]5--10% intergranular glass, 96% Al[sub 2]O[sub 3] bonded to sapphire, and a model sapphire/glass/sapphire system fabricated by diffusion bonding etched and unetched pieces of sapphire onto which 30--50 nm of SiO[sub 2] had been sputter deposited. These systems span a broad range of glass contents, and permit observation of healing behavior with varying glass content. The results were compared with analytical models and results of similar studies in completely crystalline systems.

  6. Healing of lithographically introduced flaws in glass and glass containing ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Ackler, H.D.

    1992-12-01

    The morphological evolution of cylindrical pores or ``channels`` and crack-like cavities in glass and glass-containing ceramics at elevated temperatures was studied. The systems studied were: Coming 7056 alkali borosilicate glass, soda-lime glass (microscope slides), a commercially available 96% Al{sub 2}O{sub 3}with {approx}5--10% intergranular glass, 96% Al{sub 2}O{sub 3} bonded to sapphire, and a model sapphire/glass/sapphire system fabricated by diffusion bonding etched and unetched pieces of sapphire onto which 30--50 nm of SiO{sub 2} had been sputter deposited. These systems span a broad range of glass contents, and permit observation of healing behavior with varying glass content. The results were compared with analytical models and results of similar studies in completely crystalline systems.

  7. DWPF GLASS BEADS AND GLASS FRIT TRANSPORT DEMONSTRATION

    Energy Technology Data Exchange (ETDEWEB)

    Adamson, D; Bradley Pickenheim, B

    2008-11-24

    DWPF is considering replacing irregularly shaped glass frit with spherical glass beads in the Slurry Mix Evaporator (SME) process to decrease the yield stress of the melter feed (a non-Newtonian Bingham Plastic). Pilot-scale testing was conducted on spherical glass beads and glass frit to determine how well the glass beads would transfer when compared to the glass frit. Process Engineering Development designed and constructed the test apparatus to aid in the understanding and impacts that spherical glass beads may have on the existing DWPF Frit Transfer System. Testing was conducted to determine if the lines would plug with the glass beads and the glass frit slurry and what is required to unplug the lines. The flow loop consisted of vertical and horizontal runs of clear PVC piping, similar in geometry to the existing system. Two different batches of glass slurry were tested: a batch of 50 wt% spherical glass beads and a batch of 50 wt% glass frit in process water. No chemicals such as formic acid was used in slurry, only water and glass formers. The glass beads used for this testing were commercially available borosilicate glass of mesh size -100+200. The glass frit was Frit 418 obtained from DWPF and is nominally -45+200 mesh. The spherical glass beads did not have a negative impact on the frit transfer system. The transferring of the spherical glass beads was much easier than the glass frit. It was difficult to create a plug with glass bead slurry in the pilot transfer system. When a small plug occurred from setting overnight with the spherical glass beads, the plug was easy to displace using only the pump. In the case of creating a man made plug in a vertical line, by filling the line with spherical glass beads and allowing the slurry to settle for days, the plug was easy to remove by using flush water. The glass frit proved to be much more difficult to transfer when compared to the spherical glass beads. The glass frit impacted the transfer system to the point

  8. Rhenium volatilization in waste glasses

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Kai; Pierce, David A. [Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Hrma, Pavel, E-mail: pavel.hrma@pnnl.gov [Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Schweiger, Michael J. [Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Kruger, Albert A. [U.S. Department of Energy, Office of River Protection, Richland, WA 99352 (United States)

    2015-09-15

    Highlights: • Re did not volatilize from a HLW feed until 1000 °C. • Re began to volatilize from LAW feeds at ∼600 °C. • The vigorous foaming and generation of gases from salts enhanced Re evaporation in LAW feeds. • The HLW glass with less foaming and salts is a promising medium for Tc immobilization. - Abstract: We investigated volatilization of rhenium (Re), sulfur, cesium, and iodine during the course of conversion of high-level waste melter feed to glass and compared the results for Re volatilization with those in low-activity waste borosilicate glasses. Whereas Re did not volatilize from high-level waste feed heated at 5 K min{sup −1} until 1000 °C, it began to volatilize from low-activity waste borosilicate glass feeds at ∼600 °C, a temperature ∼200 °C below the onset temperature of evaporation from pure KReO{sub 4}. Below 800 °C, perrhenate evaporation in low-activity waste melter feeds was enhanced by vigorous foaming and generation of gases from molten salts as they reacted with the glass-forming constituents. At high temperatures, when the glass-forming phase was consolidated, perrhenates were transported to the top surface of glass melt in bubbles, typically together with sulfates and halides. Based on the results of this study (to be considered preliminary at this stage), the high-level waste glass with less foaming and salts appears a promising medium for technetium immobilization.

  9. sup 1 sup 1 B nutation NMR study of powdered borosilicates

    CERN Document Server

    Woo, A J; Han, D Y

    1998-01-01

    In this work, we applied the 1D sup 1 sup 1 B nutation NMR method for the analysis of the local structural environments in powdered borosilicates (SiO sub 2 -B sub 2 O sub 3). Spin dynamics during a rf irradiation for spin I=3/2 was analytically calculated with a density matrix formalism. Spectral simulation programs were written in MATLAB on a PC. Two borosilicates prepared by the sol-gel process at different stabilization temperature were used for the 1D sup 1 sup 1 B nutation NMR experiment. The sup 1 sup 1 B NMR parameters, quadrupole coupling constants (e sup 2 qQ/h) and asymmetry parameters (eta), for each borosilicate were extracted from the nonlinear least-squares fitting. The effects of heat treatments on the local structures of boron sites in borosilicates were discussed.

  10. Modelling the local atomic structure of molybdenum in nuclear waste glasses with ab initio molecular dynamics simulations

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2016-01-01

    The nature of chemical bonding of molybdenum in high level nuclear waste glasses has been elucidated by ab initio molecular dynamics simulations. Two compositions, (SiO2)57.5 – (B2O3)10 – (Na2O)15 – (CaO)15 – (MoO3)2.5 and (SiO2)57.3 – (B2O3)20 – (Na2O)6.8 – (Li2O)13.4 – (MoO3)2.5 , were considered in order to investigate the effect of ionic and covalent components on the glass structure and the formation of the crystallisation precursors (Na2MoO4 and CaMoO4). The coordination environments of Mo cations and the corresponding bond lengths calculated from our model are in excellent agreement with experimental observations. The analysis of the first coordination shell reveals two different types of molybdenum host matrix bonds in the lithium sodium borosilicate glass. Based on the structural data and the bond valence model, we demonstrate that the Mo cation can be found in a redox state and the molybdate tetrahedron can be connected with the borosilicate network in a way that inhibits the formation of crystalline molybdates. These results significantly extend our understanding of bonding in Mo-containing nuclear waste glasses and demonstrate that tailoring the glass composition to specific heavy metal constituents can facilitate incorporation of heavy metals at high concentrations. K.K. was supported through the Impact Studentship scheme at UCL co-funded by the IHI Corporation and UCL. P.V.S. thanks the Royal Society, which supported preliminary work on this project, and the Laboratory Directed Research and Development program at PNNL, a multiprogram national laboratory operated by Battelle for the U.S. Department of Energy. Via our membership of the UK's HEC Materials Chemistry Consortium, which is funded by EPSRC (EP/L000202), this work used the ARCHER UK National Supercomputing Service (http://www.archer.ac.uk).

  11. Development of a new concept for controlling the thermal expansion of glass ceramic composites with tailored flowability demonstrated on the example high-temperature fuel cells; Entwicklung eines neuen Konzepts zur Steuerung der thermischen Ausdehnung von glaskeramischen Verbundwerkstoffen mit angepasster Fliessfaehigkeit am Beispiel der Hochtemperatur-Brennstoffzelle

    Energy Technology Data Exchange (ETDEWEB)

    Wanko, Eric

    2011-09-26

    In the joining technology, composite materials based on glass, glass ceramics (GC) and glass ceramic composites (GCC) become more and more important. Due to the increasingly required multi-functionality of the sealant material (for e.g. coefficient of expansion, flow ability, etc..), the developed sealant material used today is based on glass ceramic composites. With these, a good adhesion of the joining components, a good flow ability of the sealant material during the joining process and a good electrical insulation and mechanical strength have to be achieved. The joining process has to take place at temperatures < 900 C. The operation conditions of the SOFC are: 600 - 800 C under oxidizing as well as reducing atmospheric conditions. The present Thesis shows that, based on the use of database and thermochemical methods, sealing materials can be swiftly adjusted to all process and operation requirements. In order to do this especially, with regards of the thermo-mechanical properties of the developed sealant material (coefficient of expansion and flow ability) during the joining process, a new concept has been designed. Joining tests have been achieved on sandwich samples. The starting point of this new concept is a metal/glass matrix composite where the coefficient of expansion was controlled by dispersing a metal phase in the glass matrix. The newly developed concept is based on glass as a matrix and a crystalline phase as a filler material. It is essential that the crystalline phase and the glass matrix composition consist of the same thermodynamic co-existence area of the selected oxide base system. Here, the glass matrix has a lower liquidus temperature compared to the crystalline filler material, while the crystalline phase which consist of a higher coefficient of expansion is used alone to tailor the coefficient of expansion of the joining material. By incorporating a single crystalline phase into the selected glass matrix, the coefficient of expansion of

  12. Tailored Porous Materials

    Energy Technology Data Exchange (ETDEWEB)

    BARTON,THOMAS J.; BULL,LUCY M.; KLEMPERER,WALTER G.; LOY,DOUGLAS A.; MCENANEY,BRIAN; MISONO,MAKOTO; MONSON,PETER A.; PEZ,GUIDO; SCHERER,GEORGE W.; VARTULI,JAMES C.; YAGHI,OMAR M.

    1999-11-09

    Tailoring of porous materials involves not only chemical synthetic techniques for tailoring microscopic properties such as pore size, pore shape, pore connectivity, and pore surface reactivity, but also materials processing techniques for tailoring the meso- and the macroscopic properties of bulk materials in the form of fibers, thin films and monoliths. These issues are addressed in the context of five specific classes of porous materials: oxide molecular sieves, porous coordination solids, porous carbons, sol-gel derived oxides, and porous heteropolyanion salts. Reviews of these specific areas are preceded by a presentation of background material and review of current theoretical approaches to adsorption phenomena. A concluding section outlines current research needs and opportunities.

  13. Selective adsorption and release of cationic organic dye molecules on mesoporous borosilicates

    Energy Technology Data Exchange (ETDEWEB)

    Paul, Manidipa; Pal, Nabanita; Bhaumik, Asim, E-mail: msab@iacs.res.in

    2012-08-01

    Mesoporous materials can play a pivotal role as a host material for delivery application to a specific part of a system. In this work we explore the selective adsorption and release of cationic organic dye molecules such as safranine T (ST) and malachite green (MG) on mesoporous borosilicate materials. The mesoporous silica SBA-15 and borosilicate materials (MBS) were prepared using non-ionic surfactant Pluronic P123 as template via evaporation induced self-assembly (EISA) method. After template removal the materials show high surface areas and in some cases ordered mesopores of dimensions ca. 6-7 nm. High surface area, mesoporosity and the presence of heteroatom (boron) help this mesoporous borosilicate material to adsorb high amount of cationic dye molecules at its surface from the respective aqueous solutions. Furthermore, the mesoporous borosilicate samples containing higher percentage adsorbed dyes show excellent release of ST or MG dye in simulated body fluid (SBF) solution at physiological pH = 7.4 and temperature 310 K. The adsorption and release efficiency of mesoporous borosilicate samples are compared with reference boron-free mesoporous pure silica material to understand the nature of adsorbate-adsorbent interaction at the surfaces. - Graphical abstract: Highly ordered 2D-hexagonal mesoporous borosilicate materials have been synthesized by using Pluronic P123 as template. The materials show very good adsorption and release of organic cationic dye molecules under physiological conditions. Highlights: Black-Right-Pointing-Pointer Highly ordered 2D-hexagonal mesoporous borosilicate. Black-Right-Pointing-Pointer Nonionic Pluoronic P123 templated mesoporous material. Black-Right-Pointing-Pointer Adsorption of organic dyes at the mesopore surface. Black-Right-Pointing-Pointer Controlled release of dyes under physiological pH and temperature. Black-Right-Pointing-Pointer Release of safranine T (ST) and malachite green (MG) dyes in simulated body fluids.

  14. Gamma radiation induced changes in nuclear waste glass containing Eu

    Science.gov (United States)

    Mohapatra, M.; Kadam, R. M.; Mishra, R. K.; Kaushik, C. P.; Tomar, B. S.; Godbole, S. V.

    2011-10-01

    Gamma radiation induced changes were investigated in sodium-barium borosilicate glasses containing Eu. The glass composition was similar to that of nuclear waste glasses used for vitrifying Trombay research reactor nuclear waste at Bhabha Atomic Research Centre, India. Photoluminescence (PL) and electron paramagnetic resonance (EPR) techniques were used to study the speciation of the rare earth (RE) ion in the matrix before and after gamma irradiation. Judd-Ofelt ( J- O) analyses of the emission spectra were done before and after irradiation. The spin counting technique was employed to quantify the number of defect centres formed in the glass at the highest gamma dose studied. PL data suggested the stabilisation of the trivalent RE ion in the borosilicate glass matrix both before and after irradiation. It was also observed that, the RE ion distributes itself in two different environments in the irradiated glass. From the EPR data it was observed that, boron oxygen hole centre based radicals are the predominant defect centres produced in the glass after irradiation along with small amount of E’ centres. From the spin counting studies the concentration of defect centres in the glass was calculated to be 350 ppm at 900 kGy. This indicated the fact that bulk of the glass remained unaffected after gamma irradiation up to 900 kGy.

  15. Liquidus temperature and chemical durability of selected glasses to immobilize rare earth oxides waste

    Energy Technology Data Exchange (ETDEWEB)

    Mohd Fadzil, Syazwani Binti; Hrma, Pavel R.; Schweiger, Michael J.; Riley, Brian J.

    2015-06-30

    Pyroprocessing is a reprocessing method for managing and reusing used nuclear fuel (UNF) by dissolving it in an electrorefiner with a molten alkali or alkaline earth chloride salt mixture while avoiding wet reprocessing. Pyroprocessing UNF with a LiCl-KCl eutectic salt releases the fission products from the fuel and generates a variety of metallic and salt-based species, including rare earth (RE) chlorides. If the RE-chlorides are converted to oxides, borosilicate glass is a prime candidate for their immobilization because of its durability and ability to dissolve almost any RE waste component into the matrix at high loadings. Crystallization that occurs in waste glasses as the waste loading increases may complicate glass processing and affect the product quality. This work compares three types of borosilicate glasses in terms of liquidus temperature (TL): the International Simple Glass designed by the International Working Group, sodium borosilicate glass developed by Korea Hydro and Nuclear Power, and the lanthanide aluminoborosilicate (LABS) glass established in the United States. The LABS glass allows the highest waste loadings (over 50 mass% RE2O3) while possessing an acceptable chemical durability.

  16. A critical study on borosilicate glassware and silica-based QMA's in nucleophilic substitution with [{sup 18}F]fluoride: influence of aluminum, boron and silicon on the reactivity of [{sup 18}F]fluoride

    Energy Technology Data Exchange (ETDEWEB)

    Svadberg, A., E-mail: anders.svadberg@uit.n [University of Tromso, Institute of Pharmacy, Department of Pharmaceutics and Biopharmaceutics, N-9037 Tromso (Norway); Clarke, A.; Dyrstad, K.; Martinsen, I. [GE Healthcare MDx R and D, Nycoveien 2, NO-0401 Oslo (Norway); Hjelstuen, O.K. [University of Tromso, Institute of Pharmacy, Department of Pharmaceutics and Biopharmaceutics, N-9037 Tromso (Norway); GE Healthcare MDx R and D, Nycoveien 2, NO-0401 Oslo (Norway)

    2011-02-15

    Leachables of borosilicate glassware and silica-based anion exchange columns (QMAs) may influence nucleophilic substitution with [{sup 18}F]fluoride ([{sup 18}F]F{sup -}). Aluminum, boron and silicon, all constituents of borosilicate glass, were found as water soluble leachables in a typical PET synthesis setup. Relevant ranges of the leachable quantities were studied based on an experimental design, in which species of the three elements were added to the labeling of the precursor for anti-1-amino-3-[{sup 18}F]fluorocyclobutyl-1-carboxylic acid ([{sup 18}F]FACBC). Levels of 0.4-2 ppm aluminum as AlCl{sub 3} had a strong negative influence on labeling yield while 4-20 ppm of boron as KBO{sub 2} and 50-250 ppm of silicon as Na{sub 2}SiO{sub 3} did not have a significant impact. Interesting interaction effects between the elements were observed, where particularly KBO{sub 2} reduced the negative effect of AlCl{sub 3} on labeling yield. It can be concluded that leachables of borosilicate glassware easily can influence nucleophilic substitution with n.c.a. [{sup 18}F]F{sup -} and give variable yields.

  17. A critical study on borosilicate glassware and silica-based QMA's in nucleophilic substitution with [18F]fluoride: influence of aluminum, boron and silicon on the reactivity of [18F]fluoride.

    Science.gov (United States)

    Svadberg, A; Clarke, A; Dyrstad, K; Martinsen, I; Hjelstuen, O K

    2011-02-01

    Leachables of borosilicate glassware and silica-based anion exchange columns (QMAs) may influence nucleophilic substitution with [(18)F]fluoride ([(18)F]F(-)). Aluminum, boron and silicon, all constituents of borosilicate glass, were found as water soluble leachables in a typical PET synthesis setup. Relevant ranges of the leachable quantities were studied based on an experimental design, in which species of the three elements were added to the labeling of the precursor for anti-1-amino-3-[(18)F]fluorocyclobutyl-1-carboxylic acid ([(18)F]FACBC). Levels of 0.4-2 ppm aluminum as AlCl(3) had a strong negative influence on labeling yield while 4-20 ppm of boron as KBO(2) and 50-250 ppm of silicon as Na(2)SiO(3) did not have a significant impact. Interesting interaction effects between the elements were observed, where particularly KBO(2) reduced the negative effect of AlCl(3) on labeling yield. It can be concluded that leachables of borosilicate glassware easily can influence nucleophilic substitution with n.c.a. [(18)F]F(-) and give variable yields.

  18. Raman signature modification induced by copper nanoparticles in silicate glass

    OpenAIRE

    2005-01-01

    International audience; Composite materials formed by metal nanoclusters embedded in glasses/glazes have been produced for centuries (Roman hematinum and Renaissance alassonti, Coptic lustre-painted glass and Islamic lustre ceramics). Comparisons were drawn from Raman analyses of alkali borosilicate glasses coloured by copper as “blue” Cu2+ (peak absorption at 750 nm), as “colourless” Cu+, and as “opaque red” Cu0 (peak absorptions at ~420 and 570 nm). In particular, Raman analyses of copper-r...

  19. Mesoscale Phase Field Modeling of Glass Strengthening Under Triaxial Compression

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yulan; Sun, Xin

    2016-09-30

    Recent hydraulic bomb and confined sleeve tests on transparent armor glass materials such as borosilicate glass and soda-lime glass showed that the glass strength was a function of confinement pressure. The measured stress-strain relation is not a straight line as most brittle materials behave under little or no confinement. Moreover, borosilicate glass exhibited a stronger compressive strength when compared to soda-lime glass, even though soda-lime has higher bulk and shear moduli as well as apparent yield strength. To better understand these experimental findings, a mesoscale phase field model is developed to simulate the nonlinear stress versus strain behaviors under confinement by considering heterogeneity formation under triaxial compression and the energy barrier of a micro shear banding event (referred to as pseudo-slip hereafter) in the amorphous glass. With calibrated modeling parameters, the simulation results demonstrate that the developed phase field model can quantitatively predict the pressure-dependent strength, and it can also explain the difference between the two types of glasses from the perspective of energy barrier associated with a pseudo-slip event.

  20. Tailoring of onboard system software

    Institute of Scientific and Technical Information of China (English)

    彭俊杰; 洪炳镕; 魏振华; 乔永强

    2003-01-01

    Tailoring of an operating system and an in embedded real-time operating system in particular is es-sential for both, kernel and operation. But many of current embedded real-time operating systems provide somebasic tailoring at the cost of depleting the flexibility of hardware, which causes the lack of flexibility, and de-grades their tailors. A layered modular tailoring model has been proposed together with some tailoring operationsto improve the flexibility of the systems, and algorithms have been proposed for verification of tailoring opera-tions with the current operating system.

  1. Composition-structure-property relation of oxide glasses

    DEFF Research Database (Denmark)

    Hermansen, Christian

    The composition of glass can be varied continuously within their glass-forming regions. This compositional flexibility makes it possible to tailor the properties of a glass for a variety of specific uses. In the industry such tailoring is done on a trial-and-error basis with only the intuition...... also increases such properties. Yet, these rules are not strictly followed even for the simplest binary oxide glasses, such as alkali silicates, borates and phosphates. In this thesis it is argued that the missing link between composition and properties is the glass structure. Structural models...... capable of ab initio prediction of the oxide glass properties from composition....

  2. Contributions of vitreous natural analogs to the investigation of long-term nuclear glass behavior; Apports des analogues naturels vitreux a la validation des codes de prediction du comportement a long terme des verres nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Techer, I

    1999-07-01

    This study assesses the extend of the analogy between the alteration behavior in water and in a moist clay environment of aluminosilicate volcanic glass and alumino-borosilicate nuclear containment glass. Basaltic glass alteration in water initially occurs by hydrolysis processes with an activation energy on the order of 73 kJ.mol{sup -1}. As the reaction progresses, the alteration rate drops by over four orders of magnitude from the initial rate r{sub 0}, The alteration kinetics are not governed by the alteration solution chemistry alone, the glass alteration film appears to have a major role as a diffusion barrier limiting the transfer of reaction species and products. All these aspects highlight the behavioral analogy between basaltic glass and nuclear borosilicate glass in aqueous media. Conversely, the alteration reaction of obsidian-type volcanic glass involves other mechanisms than those governing the dissolution of borosilicate glass. Basaltic glass alteration is also examined in the presence of a clay environmental material, in a study of the natural basaltic glass and argillaceous pelites system of the Salagou basin in southern France, in an approach combining mineralogical, chemical and isotopic data to assess the interactions between a basaltic glass and the argillaceous pelites. Laboratory leach test results with basaltic glass and measured data for the Salagou glass in its natural environment are modeled using a code implementing a kinetic law coupling diffusive transfer of dissolved silica with a reaction affinity law. (author)

  3. Reduction of Glass Surface Reflectance by Ion Beam Surface Modification

    Energy Technology Data Exchange (ETDEWEB)

    Mark Spitzer

    2011-03-11

    This is the final report for DOE contract DE-EE0000590. The purpose of this work was to determine the feasibility of the reduction of the reflection from the front of solar photovoltaic modules. Reflection accounts for a power loss of approximately 4%. A solar module having an area of one square meter with an energy conversion efficiency of 18% generates approximately 180 watts. If reflection loss can be eliminated, the power output can be increased to 187 watts. Since conventional thin-film anti-reflection coatings do not have sufficient environmental stability, we investigated the feasibility of ion beam modification of the glass surface to obtain reduction of reflectance. Our findings are generally applicable to all solar modules that use glass encapsulation, as well as commercial float glass used in windows and other applications. Ion implantation of argon, fluorine, and xenon into commercial low-iron soda lime float glass, standard float glass, and borosilicate glass was studied by implantation, annealing, and measurement of reflectance. The three ions all affected reflectance. The most significant change was obtained by argon implantation into both low-iron and standard soda-lime glass. In this way samples were formed with reflectance lower than can be obtained with a single-layer coatings of magnesium fluoride. Integrated reflectance was reduced from 4% to 1% in low-iron soda lime glass typical of the glass used in solar modules. The reduction of reflectance of borosilicate glass was not as large; however borosilicate glass is not typically used in flat plate solar modules. Unlike conventional semiconductor ion implantation doping, glass reflectance reduction was found to be tolerant to large variations in implant dose, meaning that the process does not require high dopant uniformity. Additionally, glass implantation does not require mass analysis. Simple, high current ion implantation equipment can be developed for this process; however, before the process

  4. Aluminum elution and precipitation in glass vials: effect of pH and buffer species.

    Science.gov (United States)

    Ogawa, Toru; Miyajima, Makoto; Wakiyama, Naoki; Terada, Katsuhide

    2015-02-01

    Inorganic extractables from glass vials may cause particle formation in the drug solution. In this study, the ability of eluting Al ion from borosilicate glass vials, and tendencies of precipitation containing Al were investigated using various pHs of phosphate, citrate, acetate and histidine buffer. Through heating, all of the buffers showed that Si and Al were eluted from glass vials in ratios almost the same as the composition of borosilicate glass, and the amounts of Al and Si from various buffer solutions at pH 7 were in the following order: citrate > phosphate > acetate > histidine. In addition, during storage after heating, the Al concentration at certain pHs of phosphate and acetate buffer solution decreased, suggesting the formation of particles containing Al. In citrate buffer, Al did not decrease in spite of the high elution amount. Considering that the solubility profile of aluminum oxide and the Al eluting profile of borosilicate glass were different, it is speculated that Al ion may be forced to leach into the buffer solution according to Si elution on the surface of glass vials. When Al ions were added to the buffer solutions, phosphate, acetate and histidine buffer showed a decrease of Al concentration during storage at a neutral range of pHs, indicating the formation of particles containing Al. In conclusion, it is suggested that phosphate buffer solution has higher possibility of forming particles containing Al than other buffer solutions.

  5. Preparation and Optical Investigations of [(Sr1-xBixTiO3]-[2SiO2B2O3]-[CeO2] Glasses

    Directory of Open Access Journals (Sweden)

    Chandkiram Gautam

    2014-01-01

    Full Text Available We are reporting synthesis and structural and optical investigation of strontium bismuth titanate borosilicate glasses with addition of one mole percent cerium oxide (CeO2. Glasses were synthesized by conventional rapid melt quench method. XRD studies of the glass samples confirm the amorphous nature. Infrared absorption spectra various strontium bismuth titanate borosilicate glass samples having glass system 60[(Sr1-xBixTiO3]-39[2SiO2B2O3]-1[CeO2] (x=0.0,0.1,0.2,0.4 were recorded over a continuous spectral range from 400 to 4000 cm−1. IR spectra were analyzed to determine and differentiate of various vibrational modes in the structural change. Raman spectroscopy of all glass samples was also carried out in the wave number range from 200 to 2000 cm−1.

  6. Effect of Thermal Treatment and Acid Leaching Process on Pore Characteristics of Nanometer Porous Glass

    Institute of Scientific and Technical Information of China (English)

    HAN Jianjun; XU Feng; LIU Jiandang; ZHAO Xiujian

    2007-01-01

    Porous glass was prepared by thermally treating sodium borosilicate glass for different time,the effect of thermal treatment on pore size distribution was discussed and the pore size of the prepared porous glass was measured by scanning electron microscopy (SEM) and differential thermal analysis (DTA). The results show that the optimum porous glass with an average diameter of 80 nm can be prepared by thermal treatment at 600 ℃ for 12 h and then acid treatment for 12 h in 2 mol· L-1 hydrochloric acid solution.

  7. The effect of chromium oxide on the properties of simulated nuclear waste glasses

    Energy Technology Data Exchange (ETDEWEB)

    Vojtech, O.; Sussmilch, J.; Urbanec, Z. [and others

    1996-02-01

    A study of the effect of chromium on the properties of selected glasses was performed in the frame of a Contract between Battelle, Pacific Northwest Laboratories and Nuclear Research Institute, ReZ. In the period from July 1994 to June 1995 two borosilicate glasses of special composition were prepared according to the PNL procedure and their physical and structural characteristics of glasses were studied. This Final Report contains a vast documentation on the properties of all glasses studied. For the preparation of the respective technology more detailed study of physico-chemical properties and crystallinity of investigated systems would be desirable.

  8. Survey of glass plutonium contents and poison selection

    Energy Technology Data Exchange (ETDEWEB)

    Plodinec, M.J.; Ramsey, W.G. [Westinghouse Savannah River Company, Aiken, SC (United States); Ellison, A.J.G.; Shaw, H. [Lawrence Livermore National Laboratory, CA (United States)

    1996-05-01

    If plutonium and other actinides are to be immobilized in glass, then achieving high concentrations in the glass is desirable. This will lead to reduced costs and more rapid immobilization. However, glasses with high actinide concentrations also bring with them undersirable characteristics, especially a greater concern about nuclear criticality, particularly in a geologic repository. The key to achieving a high concentration of actinide elements in a glass is to formulate the glass so that the solubility of actinides is high. At the same time, the glass must be formulated so that the glass also contains neutron poisons, which will prevent criticality during processing and in a geologic repository. In this paper, the solubility of actinides, particularly plutonium, in three types of glasses are discussed. Plutonium solubilities are in the 2-4 wt% range for borosilicate high-level waste (HLW) glasses of the type which will be produced in the US. This type of glass is generally melted at relatively low temperatures, ca. 1150{degrees}C. For this melting temperature, the glass can be reformulated to achieve plutonium solubilities of at least 7 wt%. This low melting temperature is desirable if one must retain volatile cesium-137 in the glass. If one is not concerned about cesium volatility, then glasses can be formulated which can contain much larger amounts of plutonium and other actinides. Plutonium concentrations of at least 15 wt% have been achieved. Thus, there is confidence that high ({ge}5 wt%) concentrations of actinides can be achieved under a variety of conditions.

  9. Effect of Uniformly and Nonuniformly Coated Al2O3 Nanoparticles over Glass Tube Heater on Pool Boiling

    Directory of Open Access Journals (Sweden)

    Nitin Doifode

    2016-01-01

    Full Text Available Effect of uniformly and nonuniformly coated Al2O3 nanoparticles over plain glass tube heater on pool boiling heat transfer was studied experimentally. A borosilicate glass tube coated with Al2O3 nanoparticle was used as test heater. The boiling behaviour was studied by using high speed camera. Result obtained for pool boiling shows enhancement in heat transfer for nanoparticle coated surface heater and compared with plain glass tube heater. Also heat transfer coefficient for nonuniformly coated nanoparticles was studied and compared with uniformly coated and plain glass tube. Coating effect of nanoparticles over glass tube increases its surface roughness and thereby creates more nucleation sites.

  10. Property Data for Simulated Americium/Curium Glasses

    Energy Technology Data Exchange (ETDEWEB)

    Riley, B.J.; Smith, D.E.; Peeler, D.K.; Reamer, I.A.; Vienna, J.D.; Schweiger, M.J.

    1999-10-20

    The authors studied the properties of mixed lanthanide-alumino-borosilicate glasses. Fifty-five glasses were designed to augment a previous, Phase I, study by systematically varying the composition of Ln{sub 2}O{sub 3} and the concentrations of Ln{sub 2}O{sub 3}, SiO{sub 2}, B{sub 2}O{sub 3}, Al{sub 2}O{sub 3}, and SrO in glass. These glasses were designed and fabricated at the Savannah River Technology Center and tested at the Pacific Northwest National Laboratory. The properties measured include the high-temperature viscosity ({eta}) as a function of temperature (T) and the liquidus temperature (T{sub L}) of Phase II test glasses.

  11. Immobilization of gadolinium in iron borophosphate glasses and iron borophosphate based glass-ceramics: Implications for the immobilization of plutonium(Ⅲ)

    Science.gov (United States)

    Wang, Fu; Liao, Qilong; Dai, Yunya; Zhu, Hanzhen

    2016-08-01

    Immobilization of gadolinium (Gd), a nonradioactive surrogate for Pu3+, in iron borophosphate glasses/glass-ceramics (IBP glasses/glass-ceramics) has been investigated. The IBP glass containing 4 mol% Gd2O3 is homogeneously amorphous. At higher Gd2O3 concentrations, additional Gd is retained in the glasses as crystalline inclusions of monazite GdPO4 crystalline phase detected with X-ray diffraction. Moreover, Gd2O3 addition increases the Tg of the IBP glasses in glass formation range, which is consistent with the structural modification of the glasses. The structure of the Gd2O3-loaded IBP glasses/glass-ceramics is mainly based on pyrophosphate units. The chemical durability of Gd2O3-loaded IBP glasses/glass-ceramics is comparable to widely used borosilicate glass waste forms and the existence of monazite GdPO4 crystalline phase does not degrade the aqueous chemical durability of the IBP glasses/glass-ceramics. The Gd-loading results imply that the solubility should not be a limiting factor in processing nuclide Pu3+ if the formed crystalline phase(s) have high chemical durability.

  12. Critical review of glass performance modeling

    Energy Technology Data Exchange (ETDEWEB)

    Bourcier, W.L. [Lawrence Livermore National Lab., CA (United States)

    1994-07-01

    Borosilicate glass is to be used for permanent disposal of high-level nuclear waste in a geologic repository. Mechanistic chemical models are used to predict the rate at which radionuclides will be released from the glass under repository conditions. The most successful and useful of these models link reaction path geochemical modeling programs with a glass dissolution rate law that is consistent with transition state theory. These models have been used to simulate several types of short-term laboratory tests of glass dissolution and to predict the long-term performance of the glass in a repository. Although mechanistically based, the current models are limited by a lack of unambiguous experimental support for some of their assumptions. The most severe problem of this type is the lack of an existing validated mechanism that controls long-term glass dissolution rates. Current models can be improved by performing carefully designed experiments and using the experimental results to validate the rate-controlling mechanisms implicit in the models. These models should be supported with long-term experiments to be used for model validation. The mechanistic basis of the models should be explored by using modern molecular simulations such as molecular orbital and molecular dynamics to investigate both the glass structure and its dissolution process.

  13. Nanoscale topographic changes on sterilized glass surfaces affect cell adhesion and spreading.

    Science.gov (United States)

    Wittenburg, Gretel; Lauer, Günter; Oswald, Steffen; Labudde, Dirk; Franz, Clemens M

    2014-08-01

    Producing sterile glass surfaces is of great importance for a wide range of laboratory and medical applications, including in vitro cell culture and tissue engineering. However, sterilization may change the surface properties of glass and thereby affect its use for medical applications, for instance as a substrate for culturing cells. To investigate potential effects of sterilization on glass surface topography, borosilicate glass coverslips were left untreated or subjected to several common sterilization procedures, including low-temperature plasma gas, gamma irradiation and steam. Imaging by atomic force microscopy demonstrated that the surface of untreated borosilicate coverslips features a complex landscape of microislands ranging from 1000 to 3000 nm in diameter and 1 to 3 nm in height. Steam treatment completely removes these microislands, producing a nanosmooth glass surface. In contrast, plasma treatment partially degrades the microisland structure, while gamma irradiation has no effect on microisland topography. To test for possible effects of the nanotopographic structures on cell adhesion, human gingival fibroblasts were seeded on untreated or sterilized glass surfaces. Analyzing fibroblast adhesion 3, 6, and 24 h after cell seeding revealed significant differences in cell attachment and spreading depending on the sterilization method applied. Furthermore, single-cell force spectroscopy revealed a connection between the nanotopographic landscape of glass and the formation of cellular adhesion forces, indicating that fibroblasts generally adhere weakly to nanosmooth but strongly to nanorough glass surfaces. Nanotopographic changes induced by different sterilization methods may therefore need to be considered when preparing sterile glass surfaces for cell culture or biomedical applications.

  14. DEVELOPMENT OF GLASS MATRICES FOR HLW RADIOACTIVE WASTES

    Energy Technology Data Exchange (ETDEWEB)

    Jantzen, C.

    2010-03-18

    Vitrification is currently the most widely used technology for the treatment of high level radioactive wastes (HLW) throughout the world. Most of the nations that have generated HLW are immobilizing in either borosilicate glass or phosphate glass. One of the primary reasons that glass has become the most widely used immobilization media is the relative simplicity of the vitrification process, e.g. melt waste plus glass forming frit additives and cast. A second reason that glass has become widely used for HLW is that the short range order (SRO) and medium range order (MRO) found in glass atomistically bonds the radionuclides and governs the melt properties such as viscosity, resistivity, sulphate solubility. The molecular structure of glass controls contaminant/radionuclide release by establishing the distribution of ion exchange sites, hydrolysis sites, and the access of water to those sites. The molecular structure is flexible and hence accounts for the flexibility of glass formulations to waste variability. Nuclear waste glasses melt between 1050-1150 C which minimizes the volatility of radioactive components such as Tc{sup 99}, Cs{sup 137}, and I{sup 129}. Nuclear waste glasses have good long term stability including irradiation resistance. Process control models based on the molecular structure of glass have been mechanistically derived and have been demonstrated to be accurate enough to control the world's largest HLW Joule heated ceramic melter in the US since 1996 at 95% confidence.

  15. Preparation of Long-Lasting Phosphorescence (LLP) Glass-Ceramic Materials

    Institute of Scientific and Technical Information of China (English)

    李成宇; 苏锵; 王淑彬

    2004-01-01

    Three kinds of glass-ceramics, i.e., Mn2+ doped zinc borosilicate, Eu2+, Dy3+ co-doped strontium aluminoborate and Eu2+, Nd3+ co-doped calcium aluminoborate were prepared, whose phosphorescence emission band peaks at 525, 516 and 464 nm, respectively. In preparation of these glass-ceramics the base glasses were gained by heating the mixed starting materials at high temperature to get the transparent glasses; then those glasses were heat-treated and turned to opaque glass-ceramics. X-ray diffraction(XRD) shows that the crystallites are ZnSiO4, SrAl2O4 and α-CaAl2B2O7, respectively. It is a useful way to get new LLP materials by the method reported in this work that may be considered as "from glass to crystal".

  16. Performance Characteristics of Waste Glass Powder Substituting Portland Cement in Mortar Mixtures

    Science.gov (United States)

    Kara, P.; Csetényi, L. J.; Borosnyói, A.

    2016-04-01

    In the present work, soda-lime glass cullet (flint, amber, green) and special glass cullet (soda-alkaline earth-silicate glass coming from low pressure mercury-discharge lamp cullet and incandescent light bulb borosilicate glass waste cullet) were ground into fine powders in a laboratory planetary ball mill for 30 minutes. CEM I 42.5N Portland cement was applied in mortar mixtures, substituted with waste glass powder at levels of 20% and 30%. Characterisation and testing of waste glass powders included fineness by laser diffraction particle size analysis, specific surface area by nitrogen adsorption technique, particle density by pycnometry and chemical analysis by X-ray fluorescence spectrophotometry. Compressive strength, early age shrinkage cracking and drying shrinkage tests, heat of hydration of mortars, temperature of hydration, X-ray diffraction analysis and volume stability tests were performed to observe the influence of waste glass powder substitution for Portland cement on physical and engineering properties of mortar mixtures.

  17. Influence of Composition of Sm2O3-Containing Rare Earth Glass on Its Absorption Spectrum

    Institute of Scientific and Technical Information of China (English)

    Zhang Qitu; Wang Tingwei; Meng Xianfeng; Shan Xiaobing; Xu Zhongzi

    2005-01-01

    Borosilicate glass with high rare earth content was fabricated by traditional method. The influence of glass compositions and rare earth content on absorption spectra was examined and discussed. With increasing Sm2O3 content, the intensity of characteristic absorption peak is increased and the absorption peak is broadened. With increasing of the ratios of SiO2/B2O3 and Al2O3/SiO2, the broadening degree of absorption peak is increased. The experimental results provide basis for making special optical glasses which have the characteristics of high absorption for special wavelength laser and high transparence for visible light.

  18. An international initiative on long-term behavior of high-level nuclear waste glass

    Directory of Open Access Journals (Sweden)

    S. Gin

    2013-06-01

    Full Text Available Nations using borosilicate glass as an immobilization material for radioactive waste have reinforced the importance of scientific collaboration to obtain a consensus on the mechanisms controlling the long-term dissolution rate of glass. This goal is deemed to be crucial for the development of reliable performance assessment models for geological disposal. The collaborating laboratories all conduct fundamental and/or applied research using modern materials science techniques. This paper briefly reviews the radioactive waste vitrification programs of the six participant nations and summarizes the current state of glass corrosion science, emphasizing the common scientific needs and justifications for on-going initiatives.

  19. An international initiative on long-term behavior of high-level nuclear waste glass

    Energy Technology Data Exchange (ETDEWEB)

    Gin, Stephane [CEA Marcoule DTCD SECM LCLT, Bagnols/Ceze (France); Abdelouas, Abdessalam [SUBATECH, Nantes (France); Criscenti, Louise J. [Sandia National Laboratories, Albuquerque, NM (United States); Ebert, W. L. [Argonne National Laboratory (ANL), Argonne, IL (United States); Ferrand, Karine [SCK·CEN, Mol (Belgium); Geisler, Thorsten [Rheinische Friedrich-Wilhelms-Univ., Bonn (Germany); Harrison, Mike T. [National Nuclear Laboratory, Sellafield, Cumbria (United Kingdom); Inagaki, Yaohiro [Kyushu Univ. (Japan). Dept. Appl. Quantum Physics and Nuclear Engineering; Mitsui, Seiichiro [Japan Atomic Energy Agency, Ibaraki (Japan); Mueller, Karl T. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States). Environmental and Molecular Science Lab.; Marra, James C. [Savannah River National Laboratory, Aiken, SC (United States); Pantano, Carlo G. [Penn State Univ., State College, PA (United States); Pierce, Eric M. [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Ryan, Joseph V. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Schofield, James M. [AMEC, Harwell Oxford (United Kingdom); Steefel, Carl I. [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). Earth Sciences Div.; Vienna, John D. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)

    2013-06-01

    Nations producing borosilicate glass as an immobilization material for radioactive wastes resulting from spent nuclear fuel reprocessing have reinforced scientific collaboration to obtain consensus on mechanisms controlling the long-term dissolution rate of glass. This goal is deemed to be crucial for the development of reliable performance assessment models for geological disposal. The collaborating laboratories all conduct fundamental and/or applied research with modern materials science techniques. The paper briefly reviews the radioactive waste vitrification programmes of the six participant nations and summarizes the state-of-the-art of glass corrosion science, emphasizing common scientific needs and justifications for on-going initiatives.

  20. Effects of phosphate buffer in parenteral drugs on particle formation from glass vials.

    Science.gov (United States)

    Ogawa, Toru; Miyajima, Makoto; Wakiyama, Naoki; Terada, Katsuhide

    2013-01-01

    The characteristics of inorganic particles generated in glass vials filled with phosphate buffer solutions were investigated. During storage, particles were visually detected in the phosphate buffer solution in particular glass vials which pass compendial tests of containers for injectable drugs. These particles were considered to be different from ordinal glass delamination, which has been reported in a number of papers because the particles were mainly composed of Al, P and O, but not Si. The formation of the particles accelerated at higher storage temperatures. Among the surface treatments tested for the glass vials, sulfur treatment showed a protective effect on the particle formation in the vials, whereas the SiO(2) coating did not have any protective effects. It was found that the elution ratio of Al and Si in the solution stored in the glass vials after the heating was similar to the ratio of Al and Si in borosilicate glass. However, the Al concentration decreased during storage (5°C, 6 months), and consequently, particle formation was observed in the solution. Adding citrate, which is a chelating agent for Al, effectively suppressed the particle formation in the heated solution. When 50 ppb and higher concentrations of Al ion were added to the phosphate buffer solution, the formation of white particles containing Al, P and O was detected. It is suggested that a phosphate buffer solution in a borosilicate glass vial has the ability to form particles due to interactions with the Al that is eluted from the glass during storage.

  1. Glass integrated nanochannel waveguide for concentration measurements

    Science.gov (United States)

    Jardinier, E.; Bucci, D.; Couston, L.; Canto, F.; Magnaldo, A.; Broquin, J.-E.

    2013-03-01

    We present a new integrated optical sensor for absorption spectroscopy in a hostile environment, based on a nanochannel waveguide structure in glass. The nanochannel waveguide is made by bonding two ion-exchanged borosilicate glass wafers, one of them being etched by reactive ion etching to create a 100 nm deep fluidic channel. Typical fluid/light interaction factors of 2.3 % can be achieved inside a 7.4 pL volume of fluid, over a 550 nm bandwidth, surmounting evanescent wave sensors in terms of confinement efficiency and allowing spectrometric measurements. Absorption measurements have been performed on hexahydrate neodymium nitrate in nitric acid solutions of various concentrations leading to a minimum detectable absorption coefficient of 0.57 cm-1, which can be further decreased by implementing low bending-loss spiral-like nanochannel waveguides.

  2. Preliminary Investigation of Sulfur Loading in Hanford LAW Glass

    Energy Technology Data Exchange (ETDEWEB)

    Vienna, John D.; Hrma, Pavel R.; Buchmiller, William C.; Ricklefs, Joel S.

    2004-04-01

    A preliminary estimate was developed for loading limits for high-sulfur low-activity waste (LAW) feeds that will be vitrified into borosilicate glass at the Hanford Site in the waste-cleanup effort. Previous studies reported in the literature were consulted to provide a basis for the estimate. The examination of previous studies led to questions about sulfur loading in Hanford LAW glass, and scoping tests were performed to help answer these questions. These results of these tests indicated that a formulation approach developed by Vienna and colleagues shows promise for maximizing LAW loading in glass. However, there is a clear need for follow-on work. The potential for significantly lowering the amount of LAW glass produced at Hanford (after the initial phase of processing) because of higher sulfur tolerances may outweigh the cost and effort required to perform the necessary testing.

  3. Microstructured apertures in planar glass substrates for ion channel research.

    Science.gov (United States)

    Fertig, Niels; George, Michael; Klau, Michèle; Meyer, Christine; Tilke, Armin; Sobotta, Constanze; Blick, Robert H; Behrends, Jan C

    2003-01-01

    We have developed planar glass chip devices for patch clamp recording. Glass has several key advantages as a substrate for planar patch clamp devices. It is a good dielectric, is well-known to interact strongly with cell membranes and is also a relatively in-expensive material. In addition, it is optically neutral. However, microstructuring processes for glass are less well established than those for silicon-based substrates. We have used ion-track etching techniques to produce micron-sized apertures into borosilicate and quartz-glass coverslips. These apertures, which can be easily produced in arrays, have been used for high resolution recording of single ion channels as well as for whole-cell current recordings from mammalian cell lines. An additional attractive application that is greatly facilitated by the combination of planar geometry with the optical neutrality of the substrate is single-molecule fluorescence recording with simultaneous single-channel measurements.

  4. RETENTION OF SULFATE IN HIGH LEVEL RADIOACTIVE WASTE GLASS

    Energy Technology Data Exchange (ETDEWEB)

    Fox, K.

    2010-09-07

    High level radioactive wastes are being vitrified at the Savannah River Site for long term disposal. Many of the wastes contain sulfate at concentrations that can be difficult to retain in borosilicate glass. This study involves efforts to optimize the composition of a glass frit for combination with the waste to improve sulfate retention while meeting other process and product performance constraints. The fabrication and characterization of several series of simulated waste glasses are described. The experiments are detailed chronologically, to provide insight into part of the engineering studies used in developing frit compositions for an operating high level waste vitrification facility. The results lead to the recommendation of a specific frit composition and a concentration limit for sulfate in the glass for the next batch of sludge to be processed at Savannah River.

  5. Towards tailored radiopeptide therapy

    Energy Technology Data Exchange (ETDEWEB)

    Radojewski, Piotr [University Hospital Bern, Institute of Nuclear Medicine, Bern (Switzerland); Dumont, Rebecca [University Hospital Basel, Institute of Nuclear Medicine, Basel (Switzerland); UCLA, Department of Radiology, David Geffen School of Medicine, Los Angeles, CA (United States); Marincek, Nicolas; Walter, Martin A. [University Hospital Bern, Institute of Nuclear Medicine, Bern (Switzerland); University Hospital Basel, Institute of Nuclear Medicine, Basel (Switzerland); Brunner, Philippe; Mueller-Brand, Jan [University Hospital Basel, Institute of Nuclear Medicine, Basel (Switzerland); Maecke, Helmut R. [University Hospital Basel, Division of Radiological Chemistry, Basel (Switzerland); Briel, Matthias [University Hospital Basel, Basel Institute for Clinical Epidemiology and Biostatistics, Basel (Switzerland)

    2015-07-15

    Somatostatin receptor-targeted radiopeptide therapy is commonly performed using single radioisotopes. We evaluated the benefits and harms of combining radioisotopes in radiopeptide therapy in patients with neuroendocrine tumor. Using multivariable-adjusted survival analyses and competing risk analyses we evaluated outcomes in patients with neuroendocrine tumor receiving {sup 90}Y-DOTATOC, {sup 177}Lu-DOTATOC or their combination. {sup 90}Y-DOTATOC plus {sup 177}Lu-DOTATOC treatment was associated with longer survival than {sup 90}Y-DOTATOC (66.1 vs. 47.5 months; n = 1,358; p < 0.001) or {sup 177}Lu-DOTATOC alone (66.1 vs. 45.5 months; n = 390; p < 0.001). {sup 177}Lu-DOTATOC was associated with longer survival than {sup 90}Y-DOTATOC in patients with solitary lesions (HR 0.3, range 0.1 - 0.7; n = 153; p = 0.005), extrahepatic metastases (HR 0.5, range 0.3 - 0.9; n = 256; p = 0.029) and metastases with low uptake (HR 0.1, range 0.05 - 0.4; n = 113; p = 0.001). {sup 90}Y-DOTATOC induced higher hematotoxicity rates than combined treatment (9.5 % vs. 4.0 %, p = 0.005) or {sup 177}Lu-DOTATOC (9.5 % vs. 1.4 %, p = 0.002). Renal toxicity was similar among the treatments. Using {sup 90}Y and {sup 177}Lu might facilitate tailoring radiopeptide therapy and improve survival in patients with neuroendocrine tumors. (orig.)

  6. Effect of host glass matrix on structural and optical behavior of glass-ceramic nanocomposite scintillators

    Science.gov (United States)

    Brooke Barta, M.; Nadler, Jason H.; Kang, Zhitao; Wagner, Brent K.; Rosson, Robert; Kahn, Bernd

    2013-12-01

    Composite scintillator systems have received increased attention in recent years due to their promise for merging the radioisotope discrimination capabilities of single crystal scintillators with the high throughput scanning capabilities of portal monitors. However, producing the high light yield required for good energy resolution has proven challenging as scintillation photons are often scattered by variations in refractive index and agglomerated scintillator crystals within the composite. This investigation sought to mitigate these common problems by using glass-ceramic nanocomposite materials systems in which nanoscale scintillating crystallites are precipitated in a controlled manner from a transparent glass matrix. Precipitating crystallites in situ precludes nanoparticle agglomeration, and limiting crystallite size to 50 nm or less mitigates the effect of refractive index mismatch between the crystals and host glass. Cerium-doped gadolinium bromide (GdBr3(Ce)) scintillating crystals were incorporated into sodium-aluminosilicate (NAS) and alumino-borosilicate (ABS) host glass matrices, and the resulting glass-ceramic structures and luminescence behavior were characterized. The as-cast glass from the ABS system displayed a highly ordered microstructure that produced the highest luminescence intensity (light yield) of the samples studied. However, heat treating to form the glass-ceramic precipitated rare-earth oxide crystallites rather than rare-earth halides. This degraded light yield relative to the unaged sample.

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

    Science.gov (United States)

    Jean, Jau-Ho; Hwang, Shiang-Po

    1994-10-01

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

  8. Natural glass analogues to alteration of nuclear waste glass: A review and recommendations for further study

    Energy Technology Data Exchange (ETDEWEB)

    McKenzie, W.F.

    1990-01-01

    The purpose of this report is to review previous work on the weathering of natural glasses; and to make recommendations for further work with respect to studying the alteration of natural glasses as it relates quantifying rates of dissolution. the first task was greatly simplified by the published papers of Jercinovic and Ewing (1987) and Byers, Jercinovic, and Ewing (1987). The second task is obviously the more difficult of the two and the author makes no claim of completeness in this regard. Glasses weather in the natural environment by reacting with aqueous solutions producing a rind of secondary solid phases. It had been proposed by some workers that the thickness of this rind is a function of the age of the glass and thus could be used to estimate glass dissolution rates. However, Jercinovic and Ewing (1987) point out that in general the rind thickness does not correlate with the age of the glass owing to the differences in time of contact with the solution compared to the actual age of the sample. It should be noted that the rate of glass dissolution is also a function of the composition of both the glass and the solution, and the temperature. Quantification of the effects of these parameters (as well as time of contact with the aqueous phase and flow rates) would thus permit a prediction of the consequences of glass-fluid interactions under varying environmental conditions. Defense high- level nuclear waste (DHLW), consisting primarily of liquid and sludge, will be encapsulated by and dispersed in a borosilicate glass before permanent storage in a HLW repository. This glass containing the DHLW serves to dilute the radionuclides and to retard their dispersion into the environment. 318 refs.

  9. Glass sealing

    Energy Technology Data Exchange (ETDEWEB)

    Brow, R.K.; Kovacic, L.; Chambers, R.S. [Sandia National Labs., Albuquerque, NM (United States)

    1996-04-01

    Hernetic glass sealing technologies developed for weapons component applications can be utilized for the design and manufacture of fuel cells. Design and processing of of a seal are optimized through an integrated approach based on glass composition research, finite element analysis, and sealing process definition. Glass sealing procedures are selected to accommodate the limits imposed by glass composition and predicted calculations.

  10. Melter Glass Removal and Dismantlement

    Energy Technology Data Exchange (ETDEWEB)

    Richardson, BS

    2000-10-31

    The U.S. Department of Energy (DOE) has been using vitrification processes to convert high-level radioactive waste forms into a stable glass for disposal in waste repositories. Vitrification facilities at the Savannah River Site (SRS) and at the West Valley Demonstration Project (WVDP) are converting liquid high-level waste (HLW) by combining it with a glass-forming media to form a borosilicate glass, which will ensure safe long-term storage. Large, slurry fed melters, which are used for this process, were anticipated to have a finite life (on the order of two to three years) at which time they would have to be replaced using remote methods because of the high radiation fields. In actuality the melters useable life spans have, to date, exceeded original life-span estimates. Initial plans called for the removal of failed melters by placing the melter assembly into a container and storing the assembly in a concrete vault on the vitrification plant site pending size-reduction, segregation, containerization, and shipment to appropriate storage facilities. Separate facilities for the processing of the failed melters currently do not exist. Options for handling these melters include (1) locating a facility to conduct the size-reduction, characterization, and containerization as originally planned; (2) long-term storing or disposing of the complete melter assembly; and (3) attempting to refurbish the melter and to reuse the melter assembly. The focus of this report is to look at methods and issues pertinent to size-reduction and/or melter refurbishment in particular, removing the glass as a part of a refurbishment or to reduce contamination levels (thus allowing for disposal of a greater proportion of the melter as low level waste).

  11. The effects of the glass surface area/solution volume ratio on glass corrosion: A critical review

    Energy Technology Data Exchange (ETDEWEB)

    Ebert, W.L. [Argonne National Lab., IL (United States). Chemical Technology Div.

    1995-03-01

    This report reviews and summarizes the present state of knowledge regarding the effects of the glass surface area/solution volume (SA/V) ratio on the corrosion behavior of borosilicate waste glasses. The SA/V ratio affects the rate of glass corrosion through the extent of dilution of corrosion products released from the glass into the leachate solution: glass corrosion products are diluted more in tests conducted at low SA/V ratios than they are in tests conducted at high SA/V ratios. Differences in the solution chemistries generated in tests conducted at different SA/V ratios then affect the observed glass corrosion behavior. Therefore, any testing parameter that affects the solution chemistry will also affect the glass corrosion rate. The results of static leach tests conducted to assess the effects of the SA/V are discussed with regard to the effects of SA/V on the solution chemistry. Test results show several remaining issues with regard to the long-term glass corrosion behavior: can the SA/V ratio be used as an accelerating parameter to characterize the advanced stages of glass corrosion relevant to long disposal times; is the alteration of the glass surface the same in tests conducted at different SA/V, and in tests conducted with monolithic and crushed glass samples; what are the effects of the SA/V and the extent of glass corrosion on the disposition of released radionuclides? These issues will bear on the prediction of the long-term performance of waste glasses during storage. The results of an experimental program conducted at ANL to address these and other remaining issues regarding the effects of SA/V on glass corrosion are described. 288 refs., 59 figs., 16 tabs.

  12. Actinide speciation in glass leach-layers: An EXAFS study

    Energy Technology Data Exchange (ETDEWEB)

    Biwer, B.M.; Soderholm, L. [Argonne National Lab., IL (United States); Greegor, R.B. [Boeing Co., Seattle, WA (United States); Lytle, F.W. [EXAFS Co., Pioche, NV (United States)

    1996-12-31

    Uranium L{sub 3} X-ray absorption data were obtained from two borosilicate glasses, which are considered as models for radioactive wasteforms, both before and after leaching. Surface sensitivity to uranium speciation was attained by a novel application of simultaneous fluorescence and electron-yield detection. Changes in speciation are clearly discernible, from U(VI) in the bulk to (UO{sub 2}){sup 2+}-uranyl in the leach layer. The leach-layer uranium concentration variations with leaching times are also determined from the data.

  13. Photowritten gratings in ion-exchanged glass waveguides.

    Science.gov (United States)

    Roman, J E; Winick, K A

    1993-05-15

    The fabrication of an ion-exchanged waveguide beam deflector containing a photowritten grating is described. The planar waveguide was fabricated by thermal K(+) exchange in a borosilicate glass. The grating was written by photobleaching an absorption defect centered at 330 am, which was created by gamma-ray irradiation of the glass. The bleaching was accomplished with the 351-nm line from an argon laser. The device achieved 35% deflection efficiency at 633 nm, which corresponded to a grating with a photoinduced index change of 2.6 x 10(-5). This is to our knowledge the first demonstration of an ion-exchanged glass waveguide device containing a permanent photowritten grating.

  14. Plutonium immobilization in glass and ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Knecht, D.A. [Lockheed Martin Idaho Technologies, Idaho Falls (United States); Murphy, W.M. [Southwest Research Institute, San Antonio, TX (United States)

    1996-05-01

    The Materials Research Society Nineteenth Annual Symposium on the Scientific Basis for Nuclear Waste Management was held in Boston on November 27 to December 1, 1995. Over 150 papers were presented at the Symposium dealing with all aspects of nuclear waste management and disposal. Fourteen oral sessions and on poster session included a Plenary session on surplus plutonium dispositioning and waste forms. The proceedings, to be published in April, 1996, will provide a highly respected, referred compilation of the state of scientific development in the field of nuclear waste management. This paper provides a brief overview of the selected Symposium papers that are applicable to plutonium immobilization and plutonium waste form performance. Waste forms that were described at the Symposium cover most of the candidate Pu immobilization options under consideration, including borosilicate glass with a melting temperature of 1150 {degrees}C, a higher temperature (1450 {degrees}C) lanthanide glass, single phase ceramics, multi-phase ceramics, and multi-phase crystal-glass composites (glass-ceramics or slags). These Symposium papers selected for this overview provide the current status of the technology in these areas and give references to the relevant literature.

  15. Structural control of the stability of nuclear waste glasses

    Science.gov (United States)

    Calas, G.; Galoisy, L.; Cormier, L.; Bergeron, B.; Jollivet, P.

    2009-05-01

    Vitrification of liquid high-level radioactive waste in borosilicate glasses has received a great attention in several countries. The fundamental properties of the waste forms are their chemical and mechanical durability. We present an overview of the local structure of inactive analogs of the French nuclear glass, using structural information obtained by a combination of X-ray absorption Fine Structure (XAFS) and Wide Angle X-ray Scattering (WAXS). We will first contrast several classes of elements, such as Zr, Mo or Zn, which give nuclear glasses peculiar positive or adverse properties for the industrial process: enhanced chemical stability, phase separation, crystal nucleation and separation. These properties may be rationalized using Pauling rules, familiar to Mineralogists, as other properties are correctly modelled in simplified glass compositions using molecular dynamics. We will also point out the importance of the melt-to-glass transition and the consequence of the glass structural properties on the resistance of glassy matrices to irradiation. Glass alteration affects the long-term stability of the glass. It is characterized by an amorphous (glass)-amorphous (gel) transformation. Depending on alteration conditions, alteration layers may have or not a protective character, which will influence radionuclide retention over time. We will present the structural modification of the surface chemistry of the glass monoliths during short-term experiments and the evolution towards a gel, which forms progressively at the expense of the glass. The protective character of the gel, observed during glass leaching under near-saturated conditions, will be rationalized by its structural properties.

  16. MoO{sub 3} incorporation in magnesium aluminosilicate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Shengheng; Ojovan, Michael I.; Hyatt, Neil C.; Hand, Russell J.

    2015-03-15

    Molybdate has a very low solubility in silicate and borosilicate glass systems and its excess presence in nuclear waste glass can cause the formation of a readily soluble “yellow phase”. In this study, the incorporation of molybdenum oxide (MoO{sub 3}) in a magnesium aluminosilicate glass system has been investigated. The prepared glasses show a higher than 90% molybdenum retention rate and up to 5.34 mol% (12.28 wt%) MoO{sub 3} can be incorporated into these glasses without causing visible phase separation. The incorporation of MoO{sub 3} increases glass density, decreases glass transition and crystallisation temperatures and intensifies Raman bands assigned to vibrations of MoO{sub 4}{sup 2−} units. When excess molybdate is added liquid–liquid phase separation and crystallisation occurs. The separated phase is spherical, 200–400 nm in diameter and randomly dispersed. Based on powder X-ray diffraction, Raman spectroscopy and transmission electron microscopy, the separated phase is identified as MgMoO{sub 4}.

  17. Strength Improvement of Glass Substrates by Using Surface Nanostructures.

    Science.gov (United States)

    Kumar, Amarendra; Kashyap, Kunal; Hou, Max T; Yeh, J Andrew

    2016-12-01

    Defects and heterogeneities degrade the strength of glass with different surface and subsurface properties. This study uses surface nanostructures to improve the bending strength of glass and investigates the effect of defects on three glass types. Borosilicate and aluminosilicate glasses with a higher defect density than fused silica exhibited 118 and 48 % improvement, respectively, in bending strength after surface nanostructure fabrication. Fused silica, exhibited limited strength improvement. Therefore, a 4-μm-deep square notch was fabricated to study the effect of a dominant defect in low defect density glass. The reduced bending strength of fused silica caused by artificial defect increased 65 % in the presence of 2-μm-deep nanostructures, and the fused silica regained its original strength when the nanostructures were 4 μm deep. In fragmentation tests, the fused silica specimen broke into two major portions because of the creation of artificial defects. The number of fragments increased when nanostructures were fabricated on the fused silica surface. Bending strength improvement and fragmentation test confirm the usability of this method for glasses with low defect densities when a dominant defect is present on the surface. Our findings indicate that nanostructure-based strengthening is suitable for all types of glasses irrespective of defect density, and the observed Weibull modulus enhancement confirms the reliability of this method.

  18. Towards tailor-made participation

    DEFF Research Database (Denmark)

    Agger, Annika

    2012-01-01

    Public participation has become an important element of governance in many Western European countries. However, among scholars and practitioners there is a recognition that participatory governance processes tend to produce systematic exclusions. Knowledge about 'who' participates and 'how......' they participate can enhance our understanding of participatory processes. This paper presents some characterisations of citizens based on a review of the literature on participation. In addition, examples of how to tailor participation for different type of citizens are provided based on studies of urban...... regeneration programmes and local environmental initiatives in Denmark. The paper concludes that in order to broaden the inclusion of affected citizens, public authorities need to be tailor participation processes by applying distinct approaches to different types of citizens...

  19. Tailored Ceramics for Laser Applications

    Energy Technology Data Exchange (ETDEWEB)

    Hollingsworth, Joel [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2007-12-10

    Transparent ceramics match or exceed the performance of single-crystal materials in laser applications, with a more-robust fabrication process. Controlling the distribution of optical dopants in transparent ceramics would allow qualitative improvements in amplifier slab design by allowing gain and loss to be varied within the material. My work aims to achieve a controlled pattern or gradient of dopant prior to sintering, in order to produce tailored ceramics.

  20. Deep drawing simulation of Tailored Blanks

    NARCIS (Netherlands)

    Berg, van den A.; Meinders, V.T.; Stokman, B.

    1998-01-01

    Tailored blanks are increasingly used in the automotive industry. A tailored blank consists of different metal parts, which are joined by a welding process. These metal parts usually have different material properties. Hence, the main advantage of using a tailored blank is to provide the right mater

  1. Surface studies on aluminized and thermally oxidized superalloy 690 substrates interacted with simulated nuclear waste and sodium borosilicate melt

    Science.gov (United States)

    Yusufali, C.; Kshirsagar, R. J.; Mishra, R. K.; Kaushik, C. P.; Sengupta, P.; Dutta, R. S.; Dey, G. K.

    2014-04-01

    Aluminized and thermally oxidized Ni-Cr-Fe based superalloy 690 substrates with Al2O3 layer on top have been exposed in nitrate based environment (simulated high level nuclear liquid waste) at 373 K for 216 hours and sodium borosilicate melt at 1248 K for 192 hours. The surfaces of exposed samples have been characterized by using Electron probe micro-analyzer (EPMA). Elemental X-ray mapping on coated specimen that exposed in simulated nuclear waste solution revealed that the surface is enriched with Ni, Cr and Al. X-ray mapping on surface of the specimen that interacted with sodium borosilicate melt indicated that the surface is composed of Al, Fe, Ni and Cr.

  2. Surface studies on aluminized and thermally oxidized superalloy 690 substrates interacted with simulated nuclear waste and sodium borosilicate melt

    Energy Technology Data Exchange (ETDEWEB)

    Yusufali, C., E-mail: yusuf@barc.gov.in; Sengupta, P.; Dutta, R. S.; Dey, G. K. [Materials Science Division, Bhabha Atomic Research Centre, Trombay, Mumbai-400085 (India); Kshirsagar, R. J. [High Pressure and Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai-400085 (India); Mishra, R. K.; Kaushik, C. P. [Waste Management Division, Bhabha Atomic Research Centre, Trombay, Mumbai-400085 (India)

    2014-04-24

    Aluminized and thermally oxidized Ni-Cr-Fe based superalloy 690 substrates with Al{sub 2}O{sub 3} layer on top have been exposed in nitrate based environment (simulated high level nuclear liquid waste) at 373 K for 216 hours and sodium borosilicate melt at 1248 K for 192 hours. The surfaces of exposed samples have been characterized by using Electron probe micro-analyzer (EPMA). Elemental X-ray mapping on coated specimen that exposed in simulated nuclear waste solution revealed that the surface is enriched with Ni, Cr and Al. X-ray mapping on surface of the specimen that interacted with sodium borosilicate melt indicated that the surface is composed of Al, Fe, Ni and Cr.

  3. Wastes based glasses and glass-ceramics

    Directory of Open Access Journals (Sweden)

    Barbieri, L.

    2001-12-01

    Full Text Available Actually, the inertization, recovery and valorisation of the wastes coming from municipal and industrial processes are the most important goals from the environmental and economical point of view. An alternative technology capable to overcome the problem of the dishomogeneity of the raw material chemical composition is the vitrification process that is able to increase the homogeneity and the constancy of the chemical composition of the system and to modulate the properties in order to address the reutilization of the waste. Moreover, the glasses obtained subjected to different controlled thermal treatments, can be transformed in semy-cristalline material (named glass-ceramics with improved properties with respect to the parent amorphous materials. In this review the tailoring, preparation and characterization of glasses and glass-ceramics obtained starting from municipal incinerator grate ash, coal and steel fly ashes and glass cullet are described.

    Realmente la inertización, recuperación y valorización de residuos que proceden de los procesos de incineración de residuos municipales y de residuos industriales son metas importantes desde el punto de vista ambiental y económico. Una tecnología alternativa capaz de superar el problema de la heterogeneidad de la composición química de los materiales de partida es el proceso de la vitrificación que es capaz de aumentar la homogeneidad y la constancia de la composición química del sistema y modular las propiedades a fin de la reutilización del residuo. En este artículo se presentan los resultados de vitrificación en que los vidrios fueron sometidos a tratamientos térmicos controlados diferentes, de manera que se transforman en materiales semicristalinos (también denominados vitrocerámicos con mejores propiedades respecto a los materiales amorfos originales. En esta revisión se muestra el diseño, preparación y caracterización de vidrios y vitrocerámicos partiendo de

  4. Recycle Glass in Foam Glass Production

    DEFF Research Database (Denmark)

    Petersen, Rasmus Rosenlund; König, Jakob; Yue, Yuanzheng

    The foam glass industry turn recycle glass into heat insulating building materials. The foaming process is relative insensitive to impurities in the recycle glass. It is therefore considered to play an important role in future glass recycling. We show and discuss trends of use of recycled glasses...... in foam glass industry and the supply sources and capacity of recycle glass....

  5. Chemical analysis of simulated high level waste glasses to support stage III sulfate solubility modeling

    Energy Technology Data Exchange (ETDEWEB)

    Fox, K. M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-03-17

    The U.S. Department of Energy (DOE), Office of Environmental Management (EM) is sponsoring an international, collaborative project to develop a fundamental model for sulfate solubility in nuclear waste glass. The solubility of sulfate has a significant impact on the achievable waste loading for nuclear waste forms within the DOE complex. These wastes can contain relatively high concentrations of sulfate, which has low solubility in borosilicate glass. This is a significant issue for low-activity waste (LAW) glass and is projected to have a major impact on the Hanford Tank Waste Treatment and Immobilization Plant (WTP). Sulfate solubility has also been a limiting factor for recent high level waste (HLW) sludge processed at the Savannah River Site (SRS) Defense Waste Processing Facility (DWPF). The low solubility of sulfate in glass, along with melter and off-gas corrosion constraints, dictate that the waste be blended with lower sulfate concentration waste sources or washed to remove sulfate prior to vitrification. The development of enhanced borosilicate glass compositions with improved sulfate solubility will allow for higher waste loadings and accelerate mission completion.The objective of the current scope being pursued by SHU is to mature the sulfate solubility model to the point where it can be used to guide glass composition development for DWPF and WTP, allowing for enhanced waste loadings and waste throughput at these facilities. A series of targeted glass compositions was selected to resolve data gaps in the model and is identified as Stage III. SHU fabricated these glasses and sent samples to SRNL for chemical composition analysis. SHU will use the resulting data to enhance the sulfate solubility model and resolve any deficiencies. In this report, SRNL provides chemical analyses for the Stage III, simulated HLW glasses fabricated by SHU in support of the sulfate solubility model development.

  6. Study of Structural Properties of Mesoporous Carbon From Fructose with Zinc Borosilicate Activator

    Directory of Open Access Journals (Sweden)

    Tutik Setianingsih

    2014-04-01

    Full Text Available Structural properties, including pore structure, functional group of carbon surface, and crystal structure of carbon built by zinc borosilicate (ZBS and ZnCl2 (Z have been investigated in this work. Physically, ZBS and ZnCl2 may act as template of carbon, whereas the Zn(II cation act as chemical activator of carbonization. All precursors of ZBS (silicagel, boric acid, and ZnCl2 may act as catalysts of caramelization. The caramelization was conducted hydrothermally at 85oC and thermally 130oC. The carbonization was conducted at 450oC. The resulted carbons were washed by using HF 48% solution, 1M HCl solution, and aquadest respectively. The solid products were characterized by using nitrogen gas adsorption, infrared spectrophotometry, X-ray diffraction, and Transmition Electron Microscopy. Result of research showed that ZBS built larger mesopore volume, larger pore domination of pore size, more hydrophobic carbon, and more amorf than ZnCl2.

  7. Physicochemical Properties of Gold Nanostructures Deposited on Glass

    Directory of Open Access Journals (Sweden)

    Zdenka Novotna

    2014-01-01

    Full Text Available Properties of gold films sputtered onto borosilicate glass substrate were studied. UV-Vis absorption spectra were used to investigate optical parameters. XRD analysis provided information about the gold crystalline nanostructure, the texture, and lattice parameter and biaxial tension was also determined by the XRD method. The surface morphology was examined by atomic force microscopy (AFM; chemical structure of sputtered gold nanostructures was examined by X-ray photoelectron spectroscopy (ARXPS. The gold crystallites are preferentially [111] oriented on the sputtered samples. Gold deposition leads to dramatic changes in the surface morphology in comparison to pristine glass substrate. Oxygen is not incorporated into the gold layer during gold deposition. Experimental data on lattice parameter were also confirmed by theoretical investigations of nanoclusters using tight-binding potentials.

  8. Time Series with Tailored Nonlinearities

    CERN Document Server

    Raeth, C

    2015-01-01

    It is demonstrated how to generate time series with tailored nonlinearities by inducing well- defined constraints on the Fourier phases. Correlations between the phase information of adjacent phases and (static and dynamic) measures of nonlinearities are established and their origin is explained. By applying a set of simple constraints on the phases of an originally linear and uncor- related Gaussian time series, the observed scaling behavior of the intensity distribution of empirical time series can be reproduced. The power law character of the intensity distributions being typical for e.g. turbulence and financial data can thus be explained in terms of phase correlations.

  9. Glass Glimpsed

    DEFF Research Database (Denmark)

    Lock, Charles

    2015-01-01

    Glass in poetry as it reflects the viewer and as its power of reflection are both reduced and enhanced by technology.......Glass in poetry as it reflects the viewer and as its power of reflection are both reduced and enhanced by technology....

  10. Cosmos & Glass

    DEFF Research Database (Denmark)

    Beim, Anne

    1996-01-01

    The article unfolds the architectural visions of glass by Bruno Taut. It refers to inspirations by Paul Sheerbart and litterature and the Crystal Chain, also it analyses the tectonic univers that can be found in the glass pavillion for the Werkbund exposition in Cologne....

  11. Silane Modification of Glass and Silica Surfaces to Obtain Equally Oil-Wet Surfaces in Glass-Covered Silicon Micromodel Applications

    Energy Technology Data Exchange (ETDEWEB)

    Grate, Jay W.; Warner, Marvin G.; Pittman, Jonathan W.; Dehoff, Karl J.; Wietsma, Thomas W.; Zhang, Changyong; Oostrom, Martinus

    2013-08-05

    The wettability of silicon and glass surfaces can be modified by silanization. However, similar treatments of glass and silica surfaces using the same silane do not necessarily yield the same wettability as determined by the oil-water contact angle. In this technical note, surface cleaning pretreatments were investigated to determine conditions that would yield oil-wet surfaces on glass with similar wettability to silica surfaces treated with the same silane, and both air-water and oil-water contact angles were determined. Air-water contact angles were less sensitive to differences between silanized silica and glass surfaces, often yielding similar values while the oil-water contact angles were quite different. Borosilicate glass surfaces cleaned with standard cleaning solution 1 (SC1) yield intermediate-wet surfaces when silanized with hexamethyldisilazane, while the same cleaning and silanization yields oil-wet surfaces on silica. However, cleaning glass in boiling concentrated nitric acid creates a surface that can be silanized to obtain oil-wet surfaces using HDMS. Moreover, this method is effective on glass with prior thermal treatment at an elevated temperature of 400oC. In this way, silica and glass can be silanized to obtain equally oil-wet surfaces using HMDS. It is demonstrated that pretreatment and silanization is feasible in silicon-silica/glass micromodels previously assembled by anodic bonding, and that the change in wettability has a significant observable effect on immiscisble fluid displacements in the pore network.

  12. Silane modification of glass and silica surfaces to obtain equally oil-wet surfaces in glass-covered silicon micromodel applications

    Science.gov (United States)

    Grate, Jay W.; Warner, Marvin G.; Pittman, Jonathan W.; Dehoff, Karl J.; Wietsma, Thomas W.; Zhang, Changyong; Oostrom, Mart

    2013-08-01

    Wettability is a key parameter influencing capillary pressures, permeabilities, fingering mechanisms, and saturations in multiphase flow processes within porous media. Glass-covered silicon micromodels provide precise structures in which pore-scale displacement processes can be visualized. The wettability of silicon and glass surfaces can be modified by silanization. However, similar treatments of glass and silica surfaces using the same silane do not necessarily yield the same wettability as determined by the oil-water contact angle. In this study, surface cleaning pretreatments were investigated to determine conditions that yield oil-wet surfaces on glass with similar wettability to silica surfaces treated with the same silane, and both air-water and oil-water contact angles were determined. Borosilicate glass surfaces cleaned with standard cleaning solution 1 (SC1) yield intermediate-wet surfaces when silanized with hexamethyldisilazane (HMDS), while the same cleaning and silanization yields oil-wet surfaces on silica. However, cleaning glass in boiling concentrated nitric acid creates a surface that can be silanized to obtain oil-wet surfaces using HMDS. Moreover, this method is effective on glass with prior thermal treatment at an elevated temperature of 400°C. In this way, silica and glass can be silanized to obtain equally oil-wet surfaces using HMDS. It is demonstrated that pretreatment and silanization is feasible in silicon-silica/glass micromodels previously assembled by anodic bonding, and that the change in wettability has a significant observable effect on immiscible fluid displacements in the pore network.

  13. SUMMARY OF FY11 SULFATE RETENTION STUDIES FOR DEFENSE WASTE PROCESSING FACILITY GLASS

    Energy Technology Data Exchange (ETDEWEB)

    Fox, K.; Edwards, T.

    2012-05-08

    This report describes the results of studies related to the incorporation of sulfate in high level waste (HLW) borosilicate glass produced at the Savannah River Site (SRS) Defense Waste Processing Facility (DWPF). A group of simulated HLW glasses produced for earlier sulfate retention studies was selected for full chemical composition measurements to determine whether there is any clear link between composition and sulfate retention over the compositional region evaluated. In addition, the viscosity of several glasses was measured to support future efforts in modeling sulfate solubility as a function of predicted viscosity. The intent of these studies was to develop a better understanding of sulfate retention in borosilicate HLW glass to allow for higher loadings of sulfate containing waste. Based on the results of these and other studies, the ability to improve sulfate solubility in DWPF borosilicate glasses lies in reducing the connectivity of the glass network structure. This can be achieved, as an example, by increasing the concentration of alkali species in the glass. However, this must be balanced with other effects of reduced network connectivity, such as reduced viscosity, potentially lower chemical durability, and in the case of higher sodium and aluminum concentrations, the propensity for nepheline crystallization. Future DWPF processing is likely to target higher waste loadings and higher sludge sodium concentrations, meaning that alkali concentrations in the glass will already be relatively high. It is therefore unlikely that there will be the ability to target significantly higher total alkali concentrations in the glass solely to support increased sulfate solubility without the increased alkali concentration causing failure of other Product Composition Control System (PCCS) constraints, such as low viscosity and durability. No individual components were found to provide a significant improvement in sulfate retention (i.e., an increase of the magnitude

  14. Modeling of Glass Making Processes for Improved Efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Thomas P. Seward III

    2003-03-31

    The overall goal of this project was to develop a high-temperature melt properties database with sufficient reliability to allow mathematical modeling of glass melting and forming processes for improved product quality, improved efficiency and lessened environmental impact. It was initiated by the United States glass industry through the NSF Industry/University Center for Glass Research (CGR) at Alfred University [1]. Because of their important commercial value, six different types/families of glass were studied: container, float, fiberglass (E- and wool-types), low-expansion borosilicate, and color TV panel glasses. CGR member companies supplied production-quality glass from all six families upon which we measured, as a function of temperature in the molten state, density, surface tension, viscosity, electrical resistivity, infrared transmittance (to determine high temperature radiative conductivity), non-Newtonian flow behavior, and oxygen partial pres sure. With CGR cost sharing, we also studied gas solubility and diffusivity in each of these glasses. Because knowledge of the compositional dependencies of melt viscosity and electrical resistivity are extremely important for glass melting furnace design and operation, these properties were studied more fully. Composition variations were statistically designed for all six types/families of glass. About 140 different glasses were then melted on a laboratory scale and their viscosity and electrical resistivity measured as a function of temperature. The measurements were completed in February 2003 and are reported on here. The next steps will be (1) to statistically analyze the compositional dependencies of viscosity and electrical resistivity and develop composition-property response surfaces, (2) submit all the data to CGR member companies to evaluate the usefulness in their models, and (3) publish the results in technical journals and most likely in book form.

  15. Reversible photoluminescence quenching of CdSe/ZnS quantum dots embedded in porous glass by ammonia vapor.

    Science.gov (United States)

    Orlova, A O; Gromova, Yu A; Maslov, V G; Andreeva, O V; Baranov, A V; Fedorov, A V; Prudnikau, A V; Artemyev, M V; Berwick, K

    2013-08-23

    The photoluminescence response of semiconductor CdSe/ZnS quantum dots embedded in a borosilicate porous glass matrix to exposure to ammonia vapor is investigated. The formation of surface complexes on the quantum dots results in quenching of the photoluminescence and a shortening of the luminescence decay time. The process is reversible, desorption of ammonia molecules from the quantum dot surface causes the photoluminescence to recover. The sensitivity of the quantum dot luminescence intensity and decay time to the interaction time and the reversibility of the photoluminescence changes make the CdSe/ZnS quantum dots in porous glass system a candidate for use as an optical sensor of ammonia.

  16. Reversible photoluminescence quenching of CdSe/ZnS quantum dots embedded in porous glass by ammonia vapor

    Science.gov (United States)

    Orlova, A. O.; Gromova, Yu A.; Maslov, V. G.; Andreeva, O. V.; Baranov, A. V.; Fedorov, A. V.; Prudnikau, A. V.; Artemyev, M. V.; Berwick, K.

    2013-08-01

    The photoluminescence response of semiconductor CdSe/ZnS quantum dots embedded in a borosilicate porous glass matrix to exposure to ammonia vapor is investigated. The formation of surface complexes on the quantum dots results in quenching of the photoluminescence and a shortening of the luminescence decay time. The process is reversible, desorption of ammonia molecules from the quantum dot surface causes the photoluminescence to recover. The sensitivity of the quantum dot luminescence intensity and decay time to the interaction time and the reversibility of the photoluminescence changes make the CdSe/ZnS quantum dots in porous glass system a candidate for use as an optical sensor of ammonia.

  17. Tailoring Magnetism in Quantum Dots

    Science.gov (United States)

    Zutic, Igor; Abolfath, Ramin; Hawrylak, Pawel

    2007-03-01

    We study magnetism in magnetically doped quantum dots as a function of particle numbers, temperature, confining potential, and the strength of Coulomb interaction screening. We show that magnetism can be tailored by controlling the electron-electron Coulomb interaction, even without changing the number of particles. The interplay of strong Coulomb interactions and quantum confinement leads to enhanced inhomogeneous magnetization which persists at substantially higher temperatures than in the non-interacting case or in the bulk-like dilute magnetic semiconductors. We predict a series of electronic spin transitions which arise from the competition between the many-body gap and magnetic thermal fluctuations. Cond-mat/0612489. [1] R. Abolfath, P. Hawrylak, I. Zuti'c, preprint.

  18. Targeted therapy: tailoring cancer treatment

    Institute of Scientific and Technical Information of China (English)

    Min Yan; Quentin Qiang Liu

    2013-01-01

    Targeted therapies include small-molecule inhibitors and monoclonal antibodies,have made treatment more tumor-specific and less toxic,and have opened new possibilities for tailoring cancer treatment.Nevertheless,there remain several challenges to targeted therapies,including molecular identification,drug resistance,and exploring reliable biomarkers.Here,we present several selected signaling pathways and molecular targets involved in human cancers including Aurora kinases,PI3K/mTOR signaling,FOXO-FOXM1 axis,and MDM2/MDM4-p53 interaction.Understanding the molecular mechanisms for tumorigenesis and development of drug resistance will provide new insights into drug discovery and design of therapeutic strategies for targeted therapies.

  19. Tailored logistics: the next advantage.

    Science.gov (United States)

    Fuller, J B; O'Conor, J; Rawlinson, R

    1993-01-01

    How many top executives have ever visited with managers who move materials from the factory to the store? How many still reduce the costs of logistics to the rent of warehouses and the fees charged by common carriers? To judge by hours of senior management attention, logistics problems do not rank high. But logistics have the potential to become the next governing element of strategy. Whether they know it or not, senior managers of every retail store and diversified manufacturing company compete in logistically distinct businesses. Customer needs vary, and companies can tailor their logistics systems to serve their customers better and more profitably. Companies do not create value for customers and sustainable advantage for themselves merely by offering varieties of goods. Rather, they offer goods in distinct ways. A particular can of Coca-Cola, for example, might be a can of Coca-Cola going to a vending machine, or a can of Coca-Cola that comes with billing services. There is a fortune buried in this distinction. The goal of logistics strategy is building distinct approaches to distinct groups of customers. The first step is organizing a cross-functional team to proceed through the following steps: segmenting customers according to purchase criteria, establishing different standards of service for different customer segments, tailoring logistics pipelines to support each segment, and creating economics of scale to determine which assets can be shared among various pipelines. The goal of establishing logistically distinct businesses is familiar: improved knowledge of customers and improved means of satisfying them.

  20. Deliberation of Effect to Glass Imprinting Analysis by Williams-Landel-Ferry Equation

    Science.gov (United States)

    Yasui, Manabu; Arai, Masahiro; Takahashi, Masaharu; Ito, Hiroaki; Ino, Tomohiro; Kaneko, Satoru; Hirabayashi, Yasuo; Maeda, Ryutaro

    The Mems-ONE is well known software which simulates thermo-viscoelastic properties in the conduct of nanoimprinting. Assuming the glass materials to be viscoelastic body, the relaxation shear modulus was measured by the creep test, Williams-Landel-Ferry (WLF) equation is applied for expressing the temperature dependence of liquid viscosity. We compared experimental with analytic results used by Mems-ONE with the condition of fixed pressure and time. Thermo-viscoelastic properties of the glass materials were estimated using unidirectional compression creep test based on traditional thermo viscoelastic theory. Glass was Borosilicate Glass (D263, Schott). Glass imprinting was carried out on Glassy Carbon (GC) mold with line & space10 μm patterns fabricated by dicing saw. The machining accuracy is most important thing as the evaluation mold. The glass imprinting temperature consulted thermo-viscoelastic properties of the glass materials. The numerical simulation was carried out on the small portion of mold and glass. The constant value of WLF equation fitting in high temperature translates the master curve of D263 with a high degree of accuracy. It caused the accuracy improvement of analysis result. In addition, we confirm that WLF equation intended to resin can use to the glass imprinting.

  1. Atomic layer deposition of alternative glass microchannel plates

    Energy Technology Data Exchange (ETDEWEB)

    O' Mahony, Aileen, E-mail: aom@incomusa.com; Craven, Christopher A.; Minot, Michael J.; Popecki, Mark A.; Renaud, Joseph M.; Bennis, Daniel C.; Bond, Justin L.; Stochaj, Michael E.; Foley, Michael R.; Adams, Bernhard W. [Incom, Inc., 294 Southbridge Road, Charlton, Massachusetts 01507 (United States); Mane, Anil U.; Elam, Jeffrey W. [Argonne National Laboratory, 9700 S. Cass Ave., Argonne, Illinois 60439 (United States); Ertley, Camden; Siegmund, Oswald H. W. [Space Sciences Laboratory, University of California, 7 Gauss Way, Berkeley, California 94720 (United States)

    2016-01-15

    The technique of atomic layer deposition (ALD) has enabled the development of alternative glass microchannel plates (MCPs) with independently tunable resistive and emissive layers, resulting in excellent thickness uniformity across the large area (20 × 20 cm), high aspect ratio (60:1 L/d) glass substrates. Furthermore, the use of ALD to deposit functional layers allows the optimal substrate material to be selected, such as borosilicate glass, which has many benefits compared to the lead-oxide glass used in conventional MCPs, including increased stability and lifetime, low background noise, mechanical robustness, and larger area (at present up to 400 cm{sup 2}). Resistively stable, high gain MCPs are demonstrated due to the deposition of uniform ALD resistive and emissive layers on alternative glass microcapillary substrates. The MCP performance characteristics reported include increased stability and lifetime, low background noise (0.04 events cm{sup −2} s{sup −1}), and low gain variation (±5%)

  2. Formability of stainless steel tailored blanks

    DEFF Research Database (Denmark)

    Bagger, Claus; Gong, Hui; Olsen, Flemming Ove

    2004-01-01

    In a number of systematic tests, the formability of tailored blanks consisting of even and different combinations of AISI304 and AISI316 in thickness of 0.8 mm and 1.5 mm have been investigated. In order to analyse the formability of tailored blanks with different sheet thickness, a method based ...

  3. Development Of Porous Glass Fiber Optic Sensors

    Science.gov (United States)

    Macedo, P. B.; Barkatt, Aa.; Feng, X.; Finger, S. M.; Hojaji, H.; Laberge, N.; Mohr, R.; Penafiel, M.; Saad, E.

    A method for producing rugged, continuous porous glass fiber optic sensors was developed. pH and temperature sensors based on this technology have been successfully produced. The sensor portion of the fiber is made porous by selective leaching of a specially formulated borosilicate glass fiber. This results in a strong, monolithic structure where the sensor portion of the fiber remains integrally attached to the rest of the fiber (which acts as a light pipe), essentially eliminating losses at the sensor-light pipe interface. Pore size in the sensor can be controllably varied by modifying heat treatment conditions, making these sensors suitable for chemical concentration measurements in liquids and gases. Appropriate dyes were chemically bonded by silanization to the large interior surface area of the porous sensors to produce the pH and temperature sensors. Cresol red and phenol red were used for pH and pinacyanol chloride was used for temperature sensing. The sensitivity of these devices can be controlled by varying the concentration of the chemically bonded dye and the length of the porous region. Optical absorbance measurements were made in the visible range. The tip of the sensors was coated with a thin, porous layer of gold to reflect the incident light, resulting in a double pass across the porous sensor. Experimental measurements were made over a pH range of 3 to 8 and a temperature range of 28-70 C. These porous glass fiber optic sensors were found to be rugged and reliable due to their monolithic structure and large interior surface area for attachment of active species. A broad range of sensors based on this technology could be developed by using different active species, such as enzymes and other biochemicals, which could be bonded to the interior surface of the porous glass sensor.

  4. Chemical Composition Measurements of LAWA44 Glass Samples

    Energy Technology Data Exchange (ETDEWEB)

    Fox, K. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Edwards, T. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Riley, W. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-11-15

    The U.S. Department of Energy (DOE) Office of River Protection (ORP) has requested that the Savannah River National Laboratory (SRNL) provide expert evaluation and experimental work in support of the River Protection Project vitrification technology development. DOE is building the Hanford Tank Waste Treatment and Immobilization Plant (WTP) at the Hanford Site in Washington to remediate 55 million gallons of radioactive waste that is temporarily stored in 177 underground tanks. The low-activity waste (LAW) fraction will be partitioned from the high-level waste (HLW). Both the LAW and HLW will then be vitrified into borosilicate glass using Joule-heated ceramic melters. Efforts are being made to increase the loading of Hanford tank wastes in the glass while conforming to processing requirements and product quality regulations. DOE-ORP has requested that SRNL support the advancement of glass formulations and process control strategies in key technical areas, as defined in the Task Technical and Quality Assurance Plan (TTQAP). One of these areas is enhancing waste glass composition/property models and broadening the compositional regions over which those models are applicable. In this report, SRNL provides chemical analysis results for several samples of a simulated LAW glass, designated LAWA44, provided by Pacific Northwest National Laboratory (PNNL) as part of an ongoing development task. The objective of the PNNL task is to determine the durability of this glass using EPA Method 1313, which will include test participants at Vanderbilt University and the University of Sheffield. A report on the compositions of similar glasses (referred to as the EPA-series glasses) was issued in March 2016.

  5. Summary Report: Glass-Ceramic Waste Forms for Combined Fission Products

    Energy Technology Data Exchange (ETDEWEB)

    Crum, Jarrod V.; Riley, Brian J.; Turo, Laura A.; Tang, Ming; Kossoy, Anna

    2011-09-23

    Glass-ceramic waste form development began in FY 2010 examining two combined waste stream options: (1) alkaline earth (CS) + lanthanide (Ln), and (2) + transition metal (TM) fission-product waste streams generated by the uranium extraction (UREX+) separations process. Glass-ceramics were successfully developed for both options however; Option 2 was selected over Option 1, at the conclusion of 2010, because Option 2 immobilized all three waste streams with only a minimal decrease in waste loading. During the first year, a series of three glass (Option 2) were fabricated that varied waste loading-WL (42, 45, and 50 mass%) at fixed molar ratios of CaO/MoO{sub 3} and B{sub 2}O{sub 3}/alkali both at 1.75. These glass-ceramics were slow cooled and characterized in terms of phase assemblage and preliminary irradiation stability. This fiscal year, further characterization was performed on the FY 2010 Option 2 glass-ceramics in terms of: static leach testing, phase analysis by transmission electron microscopy (TEM), and irradiation stability (electron and ion). Also, a new series of glass-ceramics were developed for Option 2 that varied the additives: Al{sub 2}O{sub 3} (0-6 mass%), molar ratio of CaO/MoO{sub 3} and B{sub 2}O{sub 3}/alkali (1.75 to 2.25) and waste loading (50, 55, and 60 mass%). Lastly, phase pure powellite and oxyapatite were synthesized for irradiation studies. Results of this fiscal year studies showed compositional flexibility, chemical stability, and radiation stability in the current glass-ceramic system. First, the phase assemblages and microstructure of all of the FY 2010 and 2011 glass-ceramics are very similar once subjected to the slow cool heat treatment. The phases identified in these glass-ceramics were oxyapatite, powellite, cerianite, and ln-borosilicate. This shows that variations in waste loading or additives can be accommodated without drastically changing the phase assemblage of the waste form, thus making the processing and performance

  6. Effects of alteration product precipitation on glass dissolution

    Energy Technology Data Exchange (ETDEWEB)

    Strachan, Denis M.; Neeway, James J.

    2014-06-01

    Understanding the mechanisms that control the durability of nuclear waste glass is paramount if reliable models are to be constructed so that the glass dissolution rate in a given geological repository can be calculated. Presently, it is agreed that (boro)silicate glasses dissolve in water at a rate dependent on the solution concentration of orthosilicic acid (H4SiO4) with higher [H4SiO4] leading to lower dissolution rates. Once the reaction has slowed as a result of the buildup of H4SiO4, another increase in the rate has been observed that corresponds to the precipitation of certain silica-bearing alteration products. However, it has also been observed that the concentration of silica-bearing solution species does not significantly decrease, indicating saturation, while other glass tracer elements concentrations continue to increase, indicating that the glass is still dissolving. In this study, we have used the Geochemist’s Workbench code to investigate the relationship between glass dissolution rates and the precipitation rate of a representative zeolitic silica-bearing alteration product, analcime [Na(AlSi2O6)∙H2O]. To simplify the calculations, we suppressed all alteration products except analcime, gibbsite (Al(OH)3), and amorphous silica. The pseudo-equilibrium-constant matrix for amorphous silica was substituted for the glass pseudo-equilibrium-constant matrix because it has been shown that silicate glasses act as a silica-only solid with respect to kinetic considerations. In this article, we present the results of our calculations of the glass dissolution rate at different values for the analcime precipitation rate constant and the effects of varying the glass dissolution rate constant at a constant analcime precipitation rate constant. From the simulations we conclude, firstly, that the rate of glass dissolution is dependent on the kinetics of

  7. Low-loss waveguides fabricated in BK7 glass by high repetition rate femtosecond fiber laser.

    Science.gov (United States)

    Eaton, Shane M; Ng, Mi Li; Bonse, Jörn; Mermillod-Blondin, Alexandre; Zhang, Haibin; Rosenfeld, Arkadi; Herman, Peter R

    2008-04-20

    For the first time femtosecond-laser writing has inscribed low-loss optical waveguides in Schott BK7 glass, a commercially important type of borosilicate widely used in optical applications. The use of a variable repetition rate laser enabled the identification of a narrow processing window at 1 MHz repetition rate with optimal waveguides exhibiting propagation losses of 0.3 dB/cm and efficient mode matching to standard optical fibers at a 1550 nm wavelength. The waveguides were characterized by complementary phase contrast and optical transmission microscopy, identifying a micrometer-sized guiding region within a larger complex structure of both positive and negative refractive index variations.

  8. Evaluation of Photocatalytic Active Coatings on Sintered Glass Tubes by Methylene Blue

    Directory of Open Access Journals (Sweden)

    Colin Awungacha Lekelefac

    2013-01-01

    Full Text Available A comparative study between ten different photocatalytic active coatings was done. The effectiveness and photocatalytic activity of the coatings were studied by degradation experiments of methylene blue (MB dye under UV light illumination. The reactor design consisting of sintered glass packed in a borosilicate tube placed between two planar dielectric barrier discharge lamps (Osram Planon is reported for the first time. The coatings consisted of either titania, silica, or zinc on sintered borosilicate glass. The advantage of sol-gel in catalyst preparation was exploited to combine catalyst to act as cocatalyst. TiO2-P25 widely applied in suspension systems was effectively immobilized on sintered glass support with the aid of tetraethylorthosilicate (TEOS solution which acted as support material. Results indicated that TiO2-P25+SiO2, TiO2-P25+SiO2+Pt, and TiOSO4_30,6wt% films showed highest degradation rates close to 100% after 90 min illumination with degradation rates exceeding 50% after 30 minutes. TTIP+Pt showed lowest degradation rate.

  9. Sulfur incorporation in high level nuclear waste glass: A S K-edge XAFS investigation

    Science.gov (United States)

    Brendebach, B.; Denecke, M. A.; Roth, G.; Weisenburger, S.

    2009-11-01

    We perform X-ray absorption fine structure (XAFS) spectroscopy measurements at the sulfur K-edge to elucidate the electronic and geometric bonding of sulfur atoms in borosilicate glass used for the vitrification of high level radioactive liquid waste. The sulfur is incorporated as sulfate, most probably as sodium sulfate, which can be deduced from the X-ray absorption near edge structure (XANES) by fingerprint comparison with reference compounds. This finding is backed up by Raman spectroscopy investigation. In the extended XAFS data, no second shell beyond the first oxygen layer is visible. We argue that this is due to the sulfate being present as small clusters located into voids of the borosilicate network. Hence, destructive interference of the variable surrounding prohibits the presence of higher shell signals. The knowledge of the sulfur bonding characteristics is essential for further optimization of the glass composition and to balance the requirements of the process and glass quality parameters, viscosity and electrical resistivity on one side, waste loading and sulfur uptake on the other side.

  10. Green-white-yellow tunable luminescence from doped transparent glass ceramics containing nanocrystals

    Science.gov (United States)

    Wang, X. F.; Yan, X. H.; Xuan, Y.; Zheng, J.; He, W. Y.

    2013-10-01

    , , and doped transparent ceramics containing nanocrystals were fabricated by a melt-quenching method and subsequent heating. Tetragonal phase spheres with 20 nm size are homogeneously precipitated among a borosilicate glass matrix. The photoluminescence spectrum of single doped transparent ceramics shows white light emission under 382 nm UV excitation. The emission color of co-doped transparent glass ceramics is tuned from green to white through energy transfer from to , and the emission color of co-doped transparent ceramics is tuned from white to yellow through energy transfer from to . CIE chromaticity and color temperature measurements show that the resulting transparent glass ceramics may be a candidate as a warm-white LED material pumped by a UV InGaN chip.

  11. A novel processing route for carbon nanotube reinforced glass-ceramic matrix composites

    Science.gov (United States)

    Dassios, Konstantinos G.; Bonnefont, Guillaume; Fantozzi, Gilbert; Matikas, Theodore E.

    2015-03-01

    The current study reports the establishment of a novel feasible way for processing glass- and ceramic- matrix composites reinforced with carbon nanotubes (CNTs). The technique is based on high shear compaction of glass/ceramic and CNT blends in the presence of polymeric binders for the production of flexible green bodies which are subsequently sintered and densified by spark plasma sintering. The method was successfully applied on a borosilicate glass / multi-wall CNT composite with final density identical to that of the full-dense ceramic. Preliminary non-destructive evaluation of dynamic mechanical properties such as Young's and shear modulus and Poisson's ratio by ultrasonics show that property improvement maximizes up to a certain CNT loading; after this threshold is exceeded, properties degrade with further loading increase.

  12. Fabrication of self-sealed circular nano/microfluidic channels in glass substrates.

    Science.gov (United States)

    Wong, Chee Chung; Agarwal, Ajay; Balasubramanian, N; Kwong, Dim Lee

    2007-04-04

    We realized self-sealing fluidics channels with circular cross-sections having diameters ranging between 30 and 2000 nm on a 200 mm glass wafer through CMOS compatible processes. Lateral voids were narrowed and sealed with non-conformal plasma enhanced chemical vapour deposition (PECVD) of phospho silicate glass (PSG) along silicon oxide trenches on silicon wafers. Leveraging on the reflow properties of PSG, circular profiled-channels were formed after undergoing high temperature annealing. These devices were subsequently transferred onto a borosilicate glass substrate through anodic bonding, and a fully transparent microfluidic device was achieved with the complete removal of the handle silicon substrate. The process offers a means of integrating electrochemical and optical sensing on the same platform, for biological research.

  13. Hollow glass for insulating layers

    Science.gov (United States)

    Merticaru, Andreea R.; Moagar-Poladian, Gabriel

    1999-03-01

    Common porous materials, some of which will be considered in the chapters of this book, include concrete, paper, ceramics, clays, porous semiconductors, chromotography materials, and natural materials like coral, bone, sponges, rocks and shells. Porous materials can also be reactive, such as in charcoal gasification, acid rock dissolution, catalyst deactivation and concrete. This study continues the investigations about the properties of, so-called, hollow glass. In this paper is presented a computer simulation approach in which the thermo-mechanical behavior of a 3D microstructure is directly computed. In this paper a computer modeling approach of porous glass is presented. One way to test the accuracy of the reconstructed microstructures is to computed their physical properties and compare to experimental measurement on equivalent systems. In this view, we imagine a new type of porous type of glass designed as buffer layer in multilayered printed boards in ICs. Our glass is a variable material with a variable pore size and surface area. The porosity could be tailored early from the deposition phases that permitting us to keep in a reasonable balance the dielectric constant and thermal conductivity.

  14. Functionally graded bioactive glass coating on magnesia partially stabilized zirconia (Mg-PSZ) for enhanced biocompatibility.

    Science.gov (United States)

    Rahaman, Mohamed N; Li, Yadong; Bal, B Sonny; Huang, Wenhai

    2008-06-01

    The coating of magnesia partially stabilized zirconia (Mg-PSZ) with a bioactive glass was investigated for enhancing the bioactivity and bone-bonding ability of Mg-PSZ orthopedic implants. Individual coatings of three different bioactive glasses were prepared by depositing a concentrated suspension of the glass particles on Mg-PSZ substrates, followed by sintering at temperatures between 750 degrees C and 850 degrees C. Two silicate-based glass compositions (designated 13-93 and 6P68), and a borosilicate glass composition (H12) were investigated. The microstructure and adhesive strength of the coatings were characterized, and the in vitro bioactivity of the glasses was compared by measuring their conversion kinetics to hydroxyapatite in an aqueous phosphate solution at 37 degrees C. The 6P68 glass provided the highest adhesive strength (40 +/- 2 MPa) but showed very limited bioactivity, whereas the H12 glass had lower adhesive strength (18 +/- 2 MPa) but the highest bioactivity. A functionally graded coating, consisting of a 6P68 interfacial layer and an H12 surface layer, was developed to provide a coating with high adhesive strength coupled with rapid in vitro bioactivity.

  15. Radiopaque strontium fluoroapatite glass-ceramics

    Directory of Open Access Journals (Sweden)

    Wolfram eHöland

    2015-10-01

    expansion (CTE. These glass-ceramics allow optical properties, especially the translucency and color, to be tailored to the needs of biomaterials for dental applications.The authors conclude that it is possible to use twofold crystallization processes to develop glass-ceramic biomaterials featuring different properties, such as specific radiopacity values, CTEs and optical characteristics.

  16. Dilute condition corrosion behavior of glass-ceramic waste form

    Science.gov (United States)

    Crum, Jarrod V.; Neeway, James J.; Riley, Brian J.; Zhu, Zihua; Olszta, Matthew J.; Tang, Ming

    2016-12-01

    Borosilicate glass-ceramics are being developed to immobilize high-level waste generated by aqueous reprocessing into a stable waste form. The corrosion behavior of this multiphase waste form is expected to be complicated by multiple phases and crystal-glass interfaces. A modified single-pass flow-through test was performed on polished monolithic coupons at a neutral pH (25 °C) and 90 °C for 33 d. The measured glass corrosion rates by micro analysis in the samples ranged from 0.019 to 0.29 g m-2 d-1 at a flow rate per surface area = 1.73 × 10-6 m s-1. The crystal phases (oxyapatite and Ca-rich powellite) corroded below quantifiable rates, by micro analysis. While, Ba-rich powellite corroded considerably in O10 sample. The corrosion rates of C1 and its replicate C20 were elevated an order of magnitude by mechanical stresses at crystal-glass interface caused by thermal expansion mismatch during cooling and unique morphology (oxyapatite clustering).

  17. Characterization of the Italian glasses and their interaction with clay

    Energy Technology Data Exchange (ETDEWEB)

    Cantale, C.; Castelli, S.; Donato, A.; Traverso, D.M.; Kaijun, L.

    1989-10-01

    The objective of this research is to select a borosilicate glass composition suitable for the solidification of the HLM stream coming from the treatment of all the high level wastes stored in Italy (MTR, CANDU and ELK RIVER) and to characterize it with reference to geological disposal. This research work is based on a pre-treatment of the waste, in order to concentrate the HLW fraction and to simplify the vitrification process by separating the greater part of the inert salts. After MCE waste pre-treatment, the resulting HLW streams are to be vitrified. Some glass compositions have been prepared and preliminary characterized. The glass named BAZ has been finally selected. The complete characterization of this glass is in progress. This paper presents the results of the physical-chemical and chemical characterizations with reference to the MCC-1 static leach test at 90 C and at a surface area to volume ratio of 10 m/sup minus 1/. Two leaching systems are being used: distilled water and synthetic interstitial claywater.

  18. Characterization of all-glass photonic band gap fiber

    Science.gov (United States)

    Buczynski, Ryszard; Kujawa, Ireneusz; Lusawa, Marzenna; Pysz, Dariusz; Martynkien, Tadeusz; Berghmans, Francis; Nasilowski, Tomasz; Thienpont, Hugo; Stepien, Ryszard

    2008-12-01

    In this paper we report on the fabrication and characterization of a double glass micro-structured fiber with low index core and photonic cladding made of high index micro-rods. Micro rods are made of lead-oxide F2 commercially available glass (SCHOTT Inc.) with a refractive index nD=1.619, while as background we use a borosilicate NC21 glass with a refractive index nD=1.533. The fiber cladding is composed of 8 rings of F2 glass micro rods ordered in hexagonal lattice. A core is created by replacement of seven F2 rods with NC21 rods. A fabricated fiber has a linear filling factor of 0.75 and micro rods diameter of 1.2 μm. A core has a diameter of 3.7 μm while cladding and total fiber diameter are 42,6μm and 120 μm, respectively. Using supercontinuum source we have measured transmission properties of the fabricated fiber. Based on measurements of the fiber samples of 18-80 cm long we have identified two photonic band gaps. Fist band gap is localized in visible range at 610 nm central wavelength. The second broadband photonic band gap is localized in near infrared and it is 80 nm wide at 840 nm central wavelength.

  19. Bioactive glass-ceramics coatings on alumina

    Energy Technology Data Exchange (ETDEWEB)

    Vitale Brovarone, C.; Verne, E.; Lupo, F. [Politecnico di Torino (Italy). Materials Science and Chemical Eng. Dept.; Moisescu, C. [Jena Univ. (Germany). Otto-Schott-Inst. fuer Glaschemie; Zanardi, L.; Bosetti, M.; Cannas, M. [Eastern Piemont Univ., Novara (Italy). Medical Science Dept.

    2001-07-01

    In this work, aiming to combine the mechanical performances of alumina with the surface properties of a bioactive material, we coated full density alumina substrates by a bioactive glass-ceramic GC. This latter was specially tailored, in term of costituents and specific quantity to have a thermal expansion coefficient close to that of alumina (8.5-9{sup *}10{sup -6}/ C) which is lower than most of the bioactive glasses and glass-ceramics already in use. In this way, we sought to avoid, as much as possible, the crack formation and propagation due to residual stresses generated by the thermal expansion coefficients mismatch. Furthermore, the high reactivity of alumina toward the glass-ceramic was carefully controlled to avoid deep compositional modification of the GC that will negatively affect its bioactivity. At this purpose, an intermediate layer of an appropriate glass G was coated prior to coat the bioactive glass-ceramic. On the materials obtained, preliminary biological tests have been done to evaluate glass-ceramic biocompatibility respect to alumina. (orig.)

  20. Tailor made preservation strategies : Food Innovation Concepts

    NARCIS (Netherlands)

    Blankestijn, J.

    2013-01-01

    High quality, long shelf life, clean label, less salt: food must comply with many requirements. From genomics and mild preservation to a ‘Quick Scan’ for process hygiene, TNO helps manufacturers to develop a tailor made preservation strategy.

  1. User-tailored Inter-Widget Communication

    NARCIS (Netherlands)

    Drachsler, Hendrik; Hoisl, Bernhard; Waglecher, Christoph

    2010-01-01

    Drachsler, H., Hoisl, B., & Wagenlecher, C. (2010, 16 September). User-tailored Inter-Widget Communication. Extending the Shared Data Interface for the Apache Wookie Engine, International Conference on Interactive Computer Aided Learning 2010, Hasselt, Belgium.

  2. Glass-water interaction: Effect of high-valence cations on glass structure and chemical durability

    Science.gov (United States)

    Hopf, J.; Kerisit, S. N.; Angeli, F.; Charpentier, T.; Icenhower, J. P.; McGrail, B. P.; Windisch, C. F.; Burton, S. D.; Pierce, E. M.

    2016-05-01

    Borosilicate glass is a durable solid, but it dissolves when in contact with aqueous fluids. The dissolution mechanism, which involves a variety of sequential reactions that occur at the solid-fluid interface, has important implications for the corrosion resistance of industrial and nuclear waste glasses. In this study, spectroscopic measurements, dissolution experiments, and Monte Carlo simulations were performed to investigate the effect of high-valence cations (HVC) on the mechanisms of glass dissolution under dilute and near-saturated conditions. Raman and NMR spectroscopy were used to determine the structural changes that occur in glass, specifically network formers (e.g., Al, Si, and B), with the addition of the HVC element hafnium in the Na2O-Al2O3-B2O3-HfO2-SiO2 system (e.g., Na/[Al + B] = 1.0 and HfO2/SiO2 from 0.0 to 0.42). Spectroscopic measurements revealed that increasing hafnium content decreases N4 (tetrahedral boron/total boron) and increases the amount of Si-O-Hf moieties in the glass. Results from flow-through experiments conducted under dilute and near-saturated conditions show a decrease of approximately 100× or more in the dissolution rate over the series from 0 to 20 mol% HfO2. Comparing the average steady-state rates obtained under dilute conditions to the rates obtained for near-saturated conditions reveals a divergence in the magnitude between the average steady state rates measured in these different conditions. The reason for this divergence was investigated more thoroughly using Monte Carlo simulations. Simulations indicate that the divergence in glass dissolution behavior under dilute and near-saturated conditions result from the stronger binding of Si sites that deposit on the surface from the influent when Hf is present in the glass. As a result, the residence time at the glass surface of these newly-formed Si sites is longer in the presence of Hf, which increases the density of anchor sites from which altered layers with higher Si

  3. Understanding of the mechanical and structural changes induced by alpha particles and heavy ions in the French simulated nuclear waste glass

    Science.gov (United States)

    Karakurt, G.; Abdelouas, A.; Guin, J.-P.; Nivard, M.; Sauvage, T.; Paris, M.; Bardeau, J.-F.

    2016-07-01

    Borosilicate glasses are considered for the long-term confinement of high-level nuclear wastes. External irradiations with 1 MeV He+ ions and 7 MeV Au5+ ions were performed to simulate effects produced by alpha particles and by recoil nuclei in the simulated SON68 nuclear waste glass. To better understand the structural modifications, irradiations were also carried out on a 6-oxides borosilicate glass, a simplified version of the SON68 glass (ISG glass). The mechanical and macroscopic properties of the glasses were studied as function of the deposited electronic and nuclear energies. Alpha particles and gold ions induced a volume change up to -0.7% and -2.7%, respectively, depending on the glass composition. Nano-indentations tests were used to determine the mechanical properties of the irradiated glasses. A decrease of about -22% to -38% of the hardness and a decrease of the reduced Young's modulus by -8% were measured after irradiations. The evolution of the glass structure was studied by Raman spectroscopy, and also 11B and 27Al Nuclear Magnetic Resonance (MAS-NMR) on a 20 MeV Kr irradiated ISG glass powder. A decrease of the silica network connectivity after irradiation with alpha particles and gold ions is deduced from the structural changes observations. NMR spectra revealed a partial conversion of BO4 to BO3 units but also a formation of AlO5 and AlO6 species after irradiation with Kr ions. The relationships between the mechanical and structural changes are also discussed.

  4. Platinoids and molybdenum in nuclear waste containment glasses: a structural study; Les platinoides et le molybdene dans des verres d'interet nucleaires: etude structurale

    Energy Technology Data Exchange (ETDEWEB)

    Le Grand, M. [CEA/VALRHO - site de Marcoule, Dept. de Recherche en Retraitement et en Vitrification (DRRV), 30 - Marcoule (France)]|[Paris-7 Univ., 75 (France)

    2000-07-01

    This work deals with the structure of borosilicate nuclear glasses and with some relationships between structure and macroscopic properties. Two types of elements which may disturb the industrial process - platinoids (Ru and Pd) and molybdenum - are central to this work. Platinoids induce weak modifications on the structure of the glass, causing a depolymerization of the glassy network, an increase of the {sup [3]}B/{sup [4]}B ratio and a modification of the medium range order around Si between 3.3 and 4.5 angstrom. The modifications of viscosity and density induced by platinoids in the glass are not due to the structural effect of the platinoids. The increase of viscosity is attributed to needle shaped RuO{sub 2}. It can be moderated by imposing reducing conditions during the elaboration of the glass. The slight difference between experimental and calculated densities is due to the increase of the volume percentage of bubbles in the glass with increasing platinoid content. Mo is either present in the glass as molybdic groupings, or mobilized in chemically complex molybdic crystalline phases. The chemical composition and mineralogy of these phases has been obtained using electronic microprobe data and XRD with Rietveld analysis. The distribution of the different elements between the crystalline phases and the glass is strongly influenced by the structural role of the various cations in the glass. The Mo present in the glass appears as MoO{sub 4} tetrahedra, independent of the borosilicate network. The formation of the crystalline phases can be explained by the existence of a precursor in which the MoO{sub 4} tetrahedra are concentrated in rich alkali and earth-alkali bearing areas of the glass. (author)

  5. Fs Laser Fabrication of Photonic Structures in Glass: the Role of Glass Composition

    Energy Technology Data Exchange (ETDEWEB)

    Krol, D M; Chan, J W; Huser, T R; Risbud, S H; Hayden, J S

    2004-06-16

    The use of fs lasers to directly write photonic structures inside a glass has great potential as a fabrication method for three-dimensional all-optical integrated components. The ability to use this technique with different glass compositions--specifically tailored for a specific photonics application--is critical to its successful exploitation. Consequently, it is important to understand how glass composition effects waveguide fabrication with fs laser pulses and how different glasses are structurally modified after exposure to fs laser pulses. We have used confocal laser spectroscopy to monitor the changes in glass structure that are associated with waveguide fabrication. Using a low power continuous wave (cw) Ar laser as excitation source we have measured both Raman and fluorescence spectra of the modified regions. Raman spectroscopy provides us with information on the network structure, whereas fluorescence measurements reveal the presence of optically active point defects in the glass. In this paper we review our work on fs-laser fabrication and characterization of photonic structures in glass and discuss the effect of glass composition on processing parameters and structural modification.

  6. The chemical durability of glass and graphite-glass composite doped with cesium oxide

    Energy Technology Data Exchange (ETDEWEB)

    Hamodi, Nasir H., E-mail: nasirhamodi@yahoo.co.uk [School of Mechanical, Aerospace and Civil Engineering (MACE)/University of Manchester, Pariser Building, F-floor, Manchester M13 9PL (United Kingdom); Abram, Timothy J. [School of Mechanical, Aerospace and Civil Engineering (MACE)/University of Manchester, Pariser Building, F-floor, Manchester M13 9PL (United Kingdom); Lowe, Tristan; Cernik, Robert J. [Henry Mosley Imaging Facility, Material Science Centre, University of Manchester, Manchester M13 9PL (United Kingdom); Lopez-Honorato, Eddie [Centro de Investigacion y Estudios Avanzados del IPN (CINVESTAV), Unidad Saltillo. Carretera Saltillo-Monterrey km 13.5, 25900 Ramos Arizpe, Coahuila (Mexico)

    2013-01-15

    The role of temperature in determining the chemical stability of a waste form, as well as its leach rate, is very complex. This is because the dissolution kinetics is dependent both on temperature and possibility of different rate-controlling mechanisms that appear at different temperature regions. The chemical durability of Alumina-Borosilicate Glass (ABG) and Glass-Graphite Composite (GGC), bearing Tristructural Isotropic (TRISO) fuel particles impregnated with cesium oxide, were compared using a static leach test. The purpose of this study is to examine the chemical durability of glass-graphite composite to encapsulate coated fuel particles, and as a possible alternative for recycling of irradiated graphite. The test was based on the ASTM C1220-98 methodology, where the leaching condition was set at a temperature varying from 298 K to 363 K for 28 days. The release of cesium from ABG was in the permissible limit and followed the Arrhenius's law of a surface controlled reaction; its activation energy (E{sub a}) was 65.6 {+-} 0.5 kJ/mol. Similar values of Ea were obtained for Boron (64.3 {+-} 0.5) and Silicon (69.6 {+-} 0.5 kJ/mol) as the main glass network formers. In contrast, the dissolution mechanism of cesium from GGC was a rapid release, with increasing temperature, and the activation energy of Cs (91.0 {+-} 5 kJ/mol) did not follow any model related to carbon kinetic dissolution in water. Microstructure analysis confirmed the formation of Crystobalite SiO{sub 2} as a gel layer and Cs{sup +1} valence state on the ABG surface.

  7. Glass for parenteral products: a surface view using the scanning electron microscope.

    Science.gov (United States)

    Roseman, T J; Brown, J A; Scothorn, W W

    1976-01-01

    The scanning electron microscope was utilized to explore the internal surface of glass ampuls and vials used in parenteral products. The surface topography of USP Type I borosilicate glass containers was viewed after exposure to "sulfur," ammonium bifluoride, and sulfuric acid treatments. The scanning electron micrographs showed startling differences in the appearance of the surface regions. "Sulfur treatment" of ampuls was associated with a pitting of the surface and the presence of sodium sulfate crystals. The sulfur treatment of vials altered the glass surface in a characteristically different manner. The dissimilarity between the surface appearances was attributed to the method of sulfur treatment. Ampuls exposed to sulfuric acid solutions at room temperature did not show the pitting associated with the sulfur treatment. Scanning electron micrographs of ammonium bifluoride-treated ampuls showed a relief effect, suggesting that the glass was affected by the bifluoride solution but that sufficient stripping of the surface layer did not occur to remove the pits associated with the sulfur treatment. Flakes emanating from the glass were identified with the aid of the electron microprobe. Scanning electron micrographs showed that these vitreous flakes resulted from a delamination of a thin layer of the glass surface. It is concluded that the scanning electron microscope, in conjunction with other analytical techniques, is a valuable tool in assessing the quality of glass used for parenteral products. The techniques studied should be of particular importance to the pharmaceutical industry where efforts are being made to reduce the levels of particulate matter in parenteral dosage forms.

  8. Dynamic fracture of inorganic glasses by hard spherical and conical projectiles.

    Science.gov (United States)

    Chaudhri, M Munawar

    2015-03-28

    In this article, high-speed photographic investigations of the dynamic crack initiation and propagation in several inorganic glasses by the impact of small spherical and conical projectiles are described. These were carried out at speeds of up to approximately 2×10(6) frames s(-1). The glasses were fused silica, 'Pyrex' (a borosilicate glass), soda lime and B(2)O(3). The projectiles were 0.8-2 mm diameter spheres of steel, glass, sapphire and tungsten carbide, and their velocities were up to 340 m s(-1). In fused silica and Pyrex, spherical projectiles' impact produced Hertzian cone cracks travelling at terminal crack velocities, whereas in soda-lime glass fast splinter cracks were generated. No crack bifurcation was observed, which has been explained by the nature of the stress intensity factor of the particle-impact-generated cracks, which leads to a stable crack growth. Crack bifurcation was, however, observed in thermally tempered glass; this bifurcation has been explained by the tensile residual stress and the associated unstable crack growth. A new explanation has been proposed for the decrease of the included angle of the Hertzian cone cracks with increasing impact velocity. B(2)O(3) glass showed dynamic compaction and plasticity owing to impact with steel spheres. Other observations, such as total contact time, crack lengths and response to oblique impacts, have also been explained.

  9. Tailoring thermal interfaces with nanomaterials

    Science.gov (United States)

    Seshadri, Indira

    mobility via pre-cure gelation, and hinder crosslinking. This thesis also demonstrates novel techniques to create tailored nanowires and networks for high k nanocomposites. Branched Ag nanowires are synthesized via controlled interruptions to microwave-stimulated polyvinylpyrrolidone-directed polyol-reduction of silver nitrate. Microwave exposure results in micrometer-long nanowires passivated with polyvinylpyrrolidone. Cooling the reaction mixture by interrupting microwave exposure promotes nanocrystal nucleation at low-surfactant coverage sites. The nascent nuclei grow into nanowire branches upon further microwave exposure. Dispersions of low fractions of the branched nanowires in polydimethylsiloxane yield up to 60 % higher thermal conductivity than that obtained using unbranched nanowire fillers. A forty-fold thermal conductivity increase is obtained by in situ welding of silver nanowire fillers inside polydimethylsiloxane using microwaves. Even for ≤ 0.04 filler volume fractions, welding facilitates nanowire networking that counteracts thermal transport bottlenecks associated with the low polymer thermal conductivity and high polymer-filler interface thermal resistances. The transparency of the polymer to microwaves precludes thermal degradation, and the composites retain high mechanical compliance as indicated by thesis further explores the use of external stimuli in the form of magnetic fields to reversibly induce nanoparticle networking and gate heat transport at interfaces, a requirement in many emerging applications. It is demonstrated that magnetic field actuation of ~ 3 - 16 vol. % of magnetite or cobalt-ferrite nanoparticles in a fluid matrix yields ~16 times enhancement of the no field effective thermal conductivity, but only in a gradient magnetic field. Heat transfer modeling shows that the enhancement arises from magnetic field gradient driven bulk convection, rather than the expected nanoparticle network formation.

  10. Glass/ceramic coatings for implants

    Science.gov (United States)

    Tomsia, Antoni P.; Saiz, Eduardo; Gomez-Vega, Jose M.; Marshall, Sally J.; Marshall, Grayson W.

    2011-09-06

    Glass coatings on metals including Ti, Ti6A14V and CrCo were prepared for use as implants. The composition of the glasses was tailored to match the thermal expansion of the substrate metal. By controlling the firing atmosphere, time, and temperature, it was possible to control the reactivity between the glass and the alloy and to fabricate coatings (25-150 .mu.m thick) with excellent adhesion to the substrate. The optimum firing temperatures ranged between 800 and 840.degree. C. at times up to 1 min in air or 15 min in N.sub.2. The same basic technique was used to create multilayered coatings with concentration gradients of hydroxyapatite (HA) particles and SiO.sub.2.

  11. Sorption of polycyclic aromatic hydrocarbons (PAHs) on glass surfaces.

    Science.gov (United States)

    Qian, Yuan; Posch, Tjorben; Schmidt, Torsten C

    2011-02-01

    Sorption of polycyclic aromatic hydrocarbons (PAHs) to glass commonly used in laboratories was studied. Sorption coefficients (Kd) of five selected PAHs to borosilicate glass surfaces were measured using column chromatography. A linear relationship between log Kd and the corresponding water solubility of the subcooled liquid (log Sw) of the investigated PAHs was observed. Based on the determined sorption coefficients our data revealed that mass loss caused by sorption on glass walls strongly depends on the ratio of solution volume to contacted surface area (V/S). The influence of solution chemistry such as ionic strength, solution pH, presence of cosolvent, and the influence of temperature on the sorption process were investigated. In the presence of ionic strength, sorption coefficients concurrently increased but less than a factor of 2 up to 0.005 M calcium chloride concentration. However, further increasing ionic strength had no influence on Kd. The cosolvent reduced sorption at a concentration of methanol in water above 0.5% (v/v); however, for benzo[a]pyrene even with 10% (v/v) methanol the mass loss would be still higher than 10% (with a V/S ratio less than 0.25). Significant effects of the solution pH and temperature were not observed. These results suggest that van der Waal's forces dominate the sorption process. In the analysis of highly hydrophobic PAHs in aqueous samples, mass loss due to sorption on glass walls should be accounted for in the final result if untreated glass is used. The presented relationship between log Kd and log Sw may help to decide if such a correction is necessary. Furthermore, the frequently used silanization of glass surfaces may not be sufficient to suppress sorption for large PAHs.

  12. Bioactive and thermally compatible glass coating on zirconia dental implants.

    Science.gov (United States)

    Kirsten, A; Hausmann, A; Weber, M; Fischer, J; Fischer, H

    2015-02-01

    The healing time of zirconia implants may be reduced by the use of bioactive glass coatings. Unfortunately, existing glasses are either bioactive like Bioglass 45S5 but thermally incompatible with the zirconia substrate, or they are thermally compatible but exhibit only a very low level of bioactivity. In this study, we hypothesized that a tailored substitution of alkaline earth metals and alkaline metals in 45S5 can lead to a glass composition that is both bioactive and thermally compatible with zirconia implants. A novel glass composition was analyzed using x-ray fluorescence spectroscopy, dilatometry, differential scanning calorimetry, and heating microscopy to investigate its chemical, physical, and thermal properties. Bioactivity was tested in vitro using simulated body fluid (SBF). Smooth and microstructured glass coatings were applied using a tailored spray technique with subsequent thermal treatment. Coating adhesion was tested on implants that were inserted in bovine ribs. The cytocompatibility of the coating was analyzed using L929 mouse fibroblasts. The coefficient of thermal expansion of the novel glass was shown to be slightly lower (11.58 · 10(-6) K(-1)) than that of the zirconia (11.67 · 10(-6) K(-1)). After storage in SBF, the glass showed reaction layers almost identical to the bioactive glass gold standard, 45S5. A process window between 800 °C and 910 °C was found to result in densely sintered and amorphous coatings. Microstructured glass coatings on zirconia implants survived a minimum insertion torque of 60 Ncm in the in vitro experiment on bovine ribs. Proliferation and cytotoxicity of the glass coatings was comparable with the controls. The novel glass composition showed a strong adhesion to the zirconia substrate and a significant bioactive behavior in the SBF in vitro experiments. Therefore, it holds great potential to significantly reduce the healing time of zirconia dental implants.

  13. Temperature-dependent evolution of RbBSi{sub 2}O{sub 6} glass into crystalline Rb-boroleucite according to X-ray diffraction data

    Energy Technology Data Exchange (ETDEWEB)

    Levin, Aleksandr A. [Technische Univ. Dresden (Germany). Inst. fuer Strukturphysik; Max-Planck-Institut fuer Chemische Physik fester Stoffe, Dresden (Germany); Filatov, Stanislav K.; Krzhizhanovskaya, Maria G. [Sankt-Peterburgskij Univ., St. Petersburg (Russian Federation). Dept. of Crystallography; Paufler, Peter [Technische Univ. Dresden (Germany). Inst. fuer Strukturphysik; Bubnova, Rimma S. [Sankt-Peterburgskij Univ., St. Petersburg (Russian Federation). Dept. of Crystallography; Russian Academy of Sciences, St. Petersburg (Russian Federation). Grebenshchikov Institute of Silicate Chemistry; Meyer, Dirk C. [Technische Univ. Dresden (Germany). Inst. fuer Strukturphysik; Technische Univ. Bergakademie Freiberg (Germany). Inst. fuer Experimentelle Physik

    2013-07-01

    The temperature-dependent evolution of the glass into a crystalline phase is studied for a rubidium borosilicate glass of composition 16.7 Rb{sub 2}O . 16.7 B{sub 2}O{sub 3} . 66.6 SiO{sub 2} employing X-ray diffraction (XRD) data. A glass sample was prepared by melt quenching from 1500 within 0.5 hour. The glass sample was step-wise annealed at 13 distinct temperatures from 300 C up to 900 C for 1 h at every annealing step. To investigate changes in the glass structure, angle-dispersive XRD was applied by using an energy-resolving semiconductor detector. The radial distribution functions (RDFs) were calculated at every stage. For polycrystalline states the crystal structure of the samples with different thermal history was refined using the Rietveld method. Comparing correlation distances estimated from RDFs of glass and polycrystalline samples and mean interatomic distances calculated for polycrystalline samples by using atomic coordinates after Rietveld refinement, it is concluded that the borosilicate glass under study is converted into the crystalline state in the temperature range of 625-750 C (i.e. in the temperature range close to the glass transition range 620-695 C as determined by differential scanning calorimetry by using of heating rate of 20 K/min) at an average heating rate of about 0.35 K/min. When the heating rate is increased up to 10 or 20 K/min, the crystallisation temperature shifts sharply up to 831-900 C and 878-951 C, respectively. XRD data give evidence that distinctive traces of cubic RbBSi{sub 2}O{sub 6} appear from glass at about 625 C and a two-phase range exists up to 750 C. After annealing at higher temperatures (800-900 C) the crystal structure practically does not change any more. (orig.)

  14. Mechanisms and application of the Excimer laser doping from spin-on glass sources for USJ fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Coutanson, S. [InESS, 23 rue du Loess BP20 CR, F-67037 Strasbourg Cedex 2 (France); Fogarassy, E. [InESS, 23 rue du Loess BP20 CR, F-67037 Strasbourg Cedex 2 (France); Venturini, J. [SOPRA-SA, 26 rue Pierre Joigneaux, 92270 Bois-Colombes (France)

    2006-04-30

    In this work was investigated numerically and experimentally a simple laser doping method employing borosilicate (BSG) glass films as dopant sources which are deposited onto Si by the spin-coating technique. Both short (20 ns) and long (200 ns) pulse duration Excimer laser beams were used to deposit a large amount of energy in short time onto the near-surface region. Under suitable conditions, the irradiation leads to surface melting and dopant incorporation by liquid phase diffusion from the surface. Boron distribution profiles in the two-pulse duration regimes were studied as well as their electrical properties, and the junction formation of less than 25 nm in depth was demonstrated.

  15. Structure and dynamics of iron doped and undoped silicate glasses

    Science.gov (United States)

    Santos, Cristiane N.; Meneses, Domingos D. S.; Echegut, Patrick; Lecomte, Emmanuel

    2010-03-01

    The optical properties of common silicate glass compositions are well known at room temperature. However, their radiative properties and structural evolution of these glasses with temperature are still largely unexplored. In this work we have measured the emissivity of a set of iron doped and undoped silicate and borosilicate glasses over an unprecedented temperature (up to 1700 K) and spectral range (40 -- 20000 cm-1). This was achieved by means of a home-made apparatus composed of a CO2 laser as the heat source, a black-body reference and two spectrometers. The optical functions were assessed using a dielectric function model [1], and the structure and dynamics of the glassy network, as well the absorption of iron species in different redox states were evidenced. We believe that these new data will help to understand the heat transfer in molten silicates. [4pt] [1] D. D. S. Meneses, G. Gruener, M. Malki, and P. Echegut, J. Non-Cryst. Solids 351, 124 (2005)

  16. The effects of CdS processing and glass substrates on the performance of CdTe solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Ferekides, C.S.; Dugan, K.; Ceekala, V.; Killian, J.; Oman, D.; Swaminathan, R.; Morel, D.L. [Univ. of South Florida, Tampa, FL (United States). Dept. of Electrical Engineering

    1994-12-31

    Cadmium Sulfide films prepared by rf sputtering and close spaced sublimation (CSS) have been used for the fabrication of CdTe/CdS thin film solar cells on borosilicate glass substrates. The CdTe layer was prepared by CSS at high processing temperatures (600 C). CdS films prepared by the chemical bath deposition process (CBD) were deposited on tin oxide coated soda lime glass substrates. For these devices the CSS CdTe films were prepared at low substrate temperatures (< 550 C). Devices prepared at low processing temperatures (CdTe-CSS/CdS-CBD) on soda lime glass substrates exhibited efficiencies in excess of 13% as measured under AM 1.5 conditions at the National Renewable Energy Laboratory.

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

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, J.H.

    1996-05-14

    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{sup 3} have been made and methods for continuous melting laser glass are under development.

  18. A completely transparent, adhesively bonded soda-lime glass block masonry system

    Directory of Open Access Journals (Sweden)

    F. Oikonomopoulou

    2015-01-01

    Full Text Available A pioneering, all transparent, self-supporting glass block facade is presented in this paper. Previously realized examples utilize embedded metal components in order to obtain the desired structural performance despite the fact that these elements greatly affect the facade’s overall transparency level. Undeniably, the oxymoron ‘transparency and strength’ remains the prime concern in such applications. In this paper, a new, innovative structural system for glass block facades is described, which demonstrably meets both criteria. The structure is exclusively constructed by monolithic glass blocks, bonded with a colourless, UV-curing adhesive, obtaining thus a maximum transparency. In addition, the desired structural performance is achieved solely through the masonry system, without any opaque substructure. Differing from previous realized projects, solid soda-lime glass blocks are used rather than borosilicate ones. This article provides an overview of the integrated architectural and structural design and discusses the choice of materials. The structural verification of the system is demonstrated. The results show that the adhesively bonded glass block structure has the required self-structural behaviour, but only if strict tolerances are met in the geometry of the glass blocks.

  19. Photoactive transparent nano-crystalline glass-ceramic for remazole red dye degradation

    Energy Technology Data Exchange (ETDEWEB)

    Gad-Allah, Tarek A., E-mail: tareqabdelshafy@yahoo.ca [Water Pollution Research Department, National Research Centre, Cairo 12311 (Egypt); Margha, Fatma H. [Department of Glass Research, National Research Centre, Cairo 12311 (Egypt)

    2012-12-15

    Graphical abstract: Display Omitted Highlights: ► Preparation and characterization of novel transparent nanocrystalline glass-ceramic. ► Precipitation of photoactive phases by using controlled heat-treatment. ► Conservation of transparency along with photoactivity. ► Using the prepared nanocrystalline glass-ceramic in water purification. -- Abstract: Transparent glass ceramic material was prepared from alkali-borosilicate glass containing titania by proper heat treatment scheme. The prepared samples were characterized using differential thermal analysis, X-ray diffraction, transmission electron microscope, selected area electron diffraction and UV–visible spectroscopy. The applied heat treatment program allowed the crystallization of nano-crystalline anatase, rutile, barium titanate, titanium borate and silicate phases while maintaining the transparency. The precipitated nano-crystalline anatase and rutile phases were responsible for the observed high photocatalytic activity of the prepared samples. Samples of 24.29 and 32.39 TiO{sub 2} wt% showed better efficiency for the decolorization of remazole red dye compared with commercial-TiO{sub 2} used in preparation of glass-ceramic. The reuse of prepared glass-ceramic photocatalyst with nearly same efficiency for different times was also proved.

  20. A statistical approach for identifying nuclear waste glass compositions that will meet quality and processability requirements

    Energy Technology Data Exchange (ETDEWEB)

    Piepel, G.F.

    1990-09-01

    Borosilicate glass provides a solid, stable medium for the disposal of high-level radioactive wastes resulting from the production of nuclear materials for United States defense needs. The glass must satisfy various quality and processability requirements on properties such as chemical durability, viscosity, and electrical conductivity. These properties depend on the composition of the waste glass, which will vary during production due to variations in nuclear waste composition and variations in the glass-making process. This paper discusses the experimentally-based statistical approach being used in the Hanford Waste Vitrification Plant (HWVP) Composition Variability Study (CVS). The overall goal of the CVS is to identify the composition region of potential HWVP waste glasses that satisfy with high confidence the applicable quality and processability requirements. This is being accomplished by melting and obtaining property data for simulated nuclear waste glasses of various compositions, and then statistically developing models and other tools needed to meet the goal. 6 refs., 1 fig., 5 tabs.

  1. Irradiation of ionic liquid ion beams on silicon and glass substrates

    Energy Technology Data Exchange (ETDEWEB)

    Takeuchi, Mitsuaki, E-mail: m-takeuchi@kuee.kyoto-u.ac.jp; Hamaguchi, Takuya; Ryuto, Hiromichi; Takaoka, Gikan H.

    2013-11-15

    Irradiation of an ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate (BMIM-PF{sub 6}) ion beam on borosilicate glass and single crystalline Si(100) surface was demonstrated by using an ionic liquid ion source we developed. Surface smoothing on the glass substrates was produced by the irradiations at an acceleration voltage of 4 kV with both positive and negative ion beams, which include cation–anion pairs attached to a single ion of either polarity. Water contact angle measurements and X-ray photoelectron spectroscopy indicated that the surface smoothing was probably caused by surface modification involving nano-ordered chemical etching by Si–F reaction, implantation and deposition of P, N and C.

  2. Highly Nonlinear Luminescence Induced by Gold Nanoparticles on Glass Surfaces with Continuous-Wave Laser Illumination

    CERN Document Server

    Wu, Yong; Toro, Ligia; Stefani, Enrico

    2015-01-01

    We report on highly nonlinear luminescence being observed from individual spherical gold nanoparticles immobilized on a borosilicate glass surface and illuminated by continuous-wave (CW) lasers with relatively low power. The nonlinear luminescence shows optical super-resolution beyond the diffraction limit in three dimensions compared to the scatting of the excitation laser light. The luminescence intensity from most nanoparticles is proportional to the 5th--7th power of the excitation laser power and has wide excitation and emission spectra across the visible wavelength range. Strong nonlinear luminescence is only observed near the glass surface. High optical nonlinearity excited by low CW laser power is related to a long-lived dark state of the gold nanoparticles, where the excitation light is strongly absorbed. This phenomenon has potential biological applications in super-resolution and deep tissue imaging.

  3. Subcritical Crack-Growth and Lifetime Behavior of Glass and SiC under Static Load

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Crack initiation and subcritical crack growth in glass sheet and SiC bar specimen under static loading were investigated to study the failure process. It has been demonstrated that the lifetime process of brittle materials involves three possible forms of crack growth: subcritical crack growth,partly subcritical crack growth and instantaneous fracture without subcritical crack growth.Curves of v-K obtained in step-by-step static fatigue tests and in constant loading rate tests showed different trends for borosilicate glass sheet. α-SiC that is generally considered immune to mechanical fatigue effect and environmental attack was also tested under static loading and the lifetime was measured. The results showed that the threshold load to damage effect was over 80% of the initial strength for the SiC.

  4. Tunable Room Temperature Second Harmonic Generation in Glasses Doped with CuCI Nanocrystalline Quantum Dots

    Energy Technology Data Exchange (ETDEWEB)

    Thantu, Napoleon; Schley, Robert Scott; B. L. Justus

    2003-05-01

    Two-photon excited emission centered at 379-426 nm in photodarkening borosilicate glass doped with CuCl nanocrystalline quantum dots at room temperature has been observed. The emission is detected in the direction of the fundamental near-infrared beam. Time- and frequency-resolved measurements at room temperature and 77 K indicate that the emission is largely coherent light characteristic of second harmonic generation (SHG). An average conversion efficiency of ~10-10 is obtained for a 2 mm thick sample. The observed SHG can originate in the individual noncentrosymmetric nanocrystals, leading to a bulk-like contribution, and at the nanocrystal-glass interface, leading to a surface contribution. The bulk-like conversion efficiency is estimated using previously reported values of coherence length (5m) and bulk nonlinear susceptibility. This bulk-like conversion efficiency estimate is found to be smaller than the measured value, suggesting a more prominent surface contribution.

  5. Glass Fibers: Quo Vadis?

    Directory of Open Access Journals (Sweden)

    Edith Mäder

    2017-02-01

    Full Text Available Since the early 1930s, the process of melting glass and subsequently forming fibers, in particular discontinuous fiber glass or continuous glass filaments, evolved into commercial-scale manufacturing.[...

  6. Fabrication, photoluminescence, and potential application in white light emitting diode of Dy3+-Tm3+ doped transparent glass ceramics containing GdSr2F7 nanocrystals

    Science.gov (United States)

    Wang, X. F.; Yan, X. H.; Bu, Y. Y.; Zhen, J.; Xuan, Y.

    2013-08-01

    Dy3+-Tm3+ doped transparent glass ceramics containing GdSr2F7 nanocrystals were fabricated successfully by a melt-quenching method and subsequent heating. X-ray diffraction and transmission electron microscopy analyses show that tetragonal GdSr2F7 nanocrystals are homogeneously precipitated among the borosilicate glass matrix. If excited with 354 nm UV light, the photoluminescence spectrum of Dy3+ single-doped transparent glass ceramics shows white-light emission. With doping of Tm3+, the overall emission color of Tm3+-Dy3+ co-doped transparent glass ceramics can be tuned from white to blue through energy transfer between Dy3+ and Tm3+. CIE chromaticity and color temperature measurements show that the resulting TGCS may be a candidate as a white LED material pumped by a UV InGaN chip.

  7. Effect of low dose electron beam irradiation on the alteration layer formed during nuclear glass leaching

    Science.gov (United States)

    Mougnaud, S.; Tribet, M.; Renault, J.-P.; Jollivet, P.; Panczer, G.; Charpentier, T.; Jégou, C.

    2016-12-01

    This investigation concerns borosilicate glass leaching mechanisms and the evolution of alteration layer under electron beam irradiation. A simple glass doped with rare earth elements was selected in order to access mechanistic and structural information and better evaluate the effects of irradiation. It was fully leached in initially pure water at 90 °C and at high glass surface area to solution volume ratio (S/V = 20 000 m-1) in static conditions. Under these conditions, the system quickly reaches the residual alteration rate regime. A small particle size fraction (2-5 μm) was sampled in order to obtain a fairly homogeneous altered material enabling the use of bulk characterization methods. External irradiations with 10 MeV electrons up to a dose of 10 MGy were performed either before or after leaching, to investigate respectively the effect of initial glass irradiation on its alteration behavior and the irradiation stability of the alteration layer. Glass dissolution rate was analyzed by regular leachate samplings and the alteration layer structure was characterized by Raman, luminescence (continuous or time-resolved), and 29Si MAS NMR and EPR spectroscopy. It was shown that the small initial glass evolutions under irradiation did not induce any modification of the leaching kinetic nor of the structure of the alteration layer. The alteration process seemed to "smooth over" the created defects. Otherwise, the alteration layer and initial glass appeared to have different behaviors under irradiation. No Eu3+ reduction was detected in the alteration layer after irradiation and the defect creation efficiency was much lower than for initial glass. This can possibly be explained by the protective role of pore water contained in the altered material (∼20%). Moreover, a slight depolymerization of the silicon network of the altered glass under irradiation with electrons was evidenced, whereas in the initial glass it typically repolymerizes.

  8. CRYSTALLIZATION IN MULTICOMPONENT GLASSES

    Energy Technology Data Exchange (ETDEWEB)

    KRUGER AA; HRMA PR

    2009-10-08

    In glass processing situations involving glass crystallization, various crystalline forms nucleate, grow, and dissolve, typically in a nonuniform temperature field of molten glass subjected to convection. Nuclear waste glasses are remarkable examples of multicomponent vitrified mixtures involving partial crystallization. In the glass melter, crystals form and dissolve during batch-to-glass conversion, melter processing, and product cooling. Crystals often agglomerate and sink, and they may settle at the melter bottom. Within the body of cooling glass, multiple phases crystallize in a non-uniform time-dependent temperature field. Self-organizing periodic distribution (the Liesegnang effect) is common. Various crystallization phenomena that occur in glass making are reviewed.

  9. Space and Missile Systems Center Tailoring: Tailoring Instructions for MIL-STD-882E

    Science.gov (United States)

    2012-11-30

    Space Command SPACE AND MISSILE SYSTEMS CENTER TAILORING TAILORING INSTRUCTIONS FOR MIL- STD -882E APPROVED FOR PUBLIC RELEASE...for MIL- STD -882E 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT...THIS PAGE unclassified Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 SMC Tailoring of MIL- STD -882E, System Safety FOREWORD This

  10. Understanding tailoring in communicating about health

    NARCIS (Netherlands)

    Hawkins, Robert P.; Kreuter, Matthew; Resnicow, Kenneth; Fishbein, Martin; Dijkstra, Arie

    2008-01-01

    'Tailoring' refers to any of a number of methods for creating communications individualized for their receivers, with the expectation that this individualization will lead to larger intended effects of these communications. Results so far have been generally positive but not consistently so, and thi

  11. Tailoring group velocity by topology optimization

    DEFF Research Database (Denmark)

    Stainko, Roman; Sigmund, Ole

    2007-01-01

    The paper describes a systematic method for the tailoring of dispersion properties of slab-based photonic crystal waveguides. The method is based on the topology optimization method which consists in repeated finite element frequency domain analyses. The goal of the optimization process is to come...

  12. Tailoring endocrine treatment for early breast cancer

    NARCIS (Netherlands)

    Fontein, Duveken Berthe Yvonne

    2014-01-01

    This thesis describes several important aspects of adjuvant endocrine therapy for postmenopausal women with endocrine-sensitive, early-stage breast cancer. In our ongoing efforts to tailor treatment so as to provide the best possible care to each of our patients, we studied the influence of various

  13. Achieving tailorable magneto-caloric effect in the Gd-Co binary amorphous alloys

    Directory of Open Access Journals (Sweden)

    C. Wu

    2016-03-01

    Full Text Available Tailorable magnetic properties and magneto-caloric effect were achieved in the Gd-Co binary amorphous alloys. It was found that the Curie temperature (Tc of the GdxCo100-x (x=50, 53, 56, 58, 60 metallic glasses can be tuned by changing the concentration of Gd as Tc =708.8-8.83x, and the mechanism involved was investigated. On the other hand, a linear correlation between the peak value of magnetic entropy change (-Δ Smpeak and Tc-2/3 is found in the amorphous alloys with a linear correlation coefficients of above 0.992. Therefore, the -ΔSmpeak of the Gd-Co binary amorphous alloys under different magnetic fields can be easily tailored by adjusting the composition of the alloy.

  14. Recycling of Glass

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Damgaard, Anders

    2011-01-01

    Glass is used for many purposes, but in the waste system glass is predominantly found in terms of beverage and food containers with a relatively short lifetime before ending up in the waste. Furthermore there is a large amount of flat glass used in building materials which also ends up in the waste...... system; this glass though has a long lifetime before ending up in the waste. Altogether these product types add up to 82% of the production of the European glass industry (IPCC, 2001). Recycling of glass in terms of cleaning and refilling of bottles as well as the use of broken glass in the production...... of new glass containers is well established in the glass industry. This chapter describes briefly howglass is produced and howwaste glass is recycled in the industry. Quality requirements and use of recycled products are discussed, as are the resource and environmental issues of glass recycling....

  15. Direct laser writing of topographic features in semiconductor-doped glass

    Science.gov (United States)

    Smuk, Andrei Y.

    2000-11-01

    Patterning of glass and silica surfaces is important for a number of modern technologies, which depend on these materials for manufacturing of both final products, such as optics, and prototypes for casting and molding. Among the fields that require glass processing on microscopic scale are optics (lenses and arrays, diffractive/holographic elements, waveguides), biotechnology (capillary electrophoresis chips and biochemical libraries) and magnetic media (landing zones for magnetic heads). Currently, standard non-laser techniques for glass surface patterning require complex multi-step processes, such as photolithography. Work carried out at Brown has shown that semiconductor- doped glasses (SDG) allow a single-step patterning process using low power continuous-wave visible lasers. SDG are composite materials, which consist of semiconductor crystallites embedded into glass matrix. In this study, borosilicate glasses doped with CdSxSe1-x nanocrystals were used. Exposure of these materials to a low-power above- the-energy gap laser beam leads to local softening, and subsequent expansion and rapid solidification of the exposed volume, resulting in a nearly spherical topographic feature on the surface. The effects of the incident power, beam configuration, and the exposure time on the formation and final parameters of the microlens were studied. Based on the numerical simulation of the temperature distribution produced by the absorbed Gaussian beam, and the ideas of viscous flow at the temperatures around the glass transition point, a model of lens formation is suggested. The light intensity distribution in the near-field of the growing lens is shown to have a significant effect on the final lens height. Fabrication of dense arrays of microlenses is shown, and the thermal and structural interactions between the neighboring lenses were also studied. Two-dimensional continuous-profile topographic features are achieved by exposure of the moving substrates to the writing

  16. Tailored Trustworthy Spaces: Solutions for the Smart Grid

    Data.gov (United States)

    Networking and Information Technology Research and Development, Executive Office of the President — The NITRD workshop on Tailored Trustworthy Spaces: Solutions for the Smart Grid was conceived by the Federal government to probe deeper into how Tailored Trustworthy...

  17. [INVITED] Laser welding of glasses at high repetition rates - Fundamentals and prospects

    Science.gov (United States)

    Richter, Sören; Zimmermann, Felix; Tünnermann, Andreas; Nolte, Stefan

    2016-09-01

    We report on the welding of various glasses with ultrashort laser pulses. Femtosecond laser pulses at repetition rates in the MHz range are focused at the interface between two substrates, resulting in multiphoton absorption and heat accumulation from successive pulses. This leads to local melting and subsequent resolidification which can be used to weld the glasses. The fundamental interaction process was studied using an in-situ micro Raman setup to measure the laser induced temperature distribution and its temporal decay. The induced network changes were analyzed by Raman spectrocopy identifying an increase of three and four membered silicon rings within the laser irradiated area. In order to determine the stability of the laser welded samples a three point bending test was used. Thereby, we identified that the maximal achievable breaking strength is limited by laser induced stress surrounding the modified material. To minimize the amount of stress bursts of laser pulses or an post processing annealing step can be applied. Besides fused silica, we welded borosilicate glasses and glasses with a low thermal expansion coefficient. Even the welding of different glass combinations is possible demonstrating the versatility of ultrashort pulse induced laser welding.

  18. Refractive index change mechanisms in different glasses induced by femtosecond laser irradiation

    Science.gov (United States)

    Fuerbach, A.; Gross, S.; Little, D.; Arriola, A.; Ams, M.; Dekker, P.; Withford, M.

    2016-07-01

    Tightly focused femtosecond laser pulses can be used to alter the refractive index of virtually all optical glasses. As the laser-induced modification is spatially limited to the focal volume of the writing beam, this technique enables the fabrication of fully three-dimensional photonic structures and devices that are automatically embedded within the host material. While it is well understood that the laser-material interaction process is initiated by nonlinear, typically multiphoton absorption, the actual mechanism that results in an increase or sometimes decrease of the refractive index of the glass strongly depends on the composition of the material and the process parameters and is still subject to scientific studies. In this paper, we present an overview of our recent work aimed at uncovering the physical and chemical processes that contribute to the observed material modification. Raman microscopy and electron microprobe analysis was used to study the induced modifications that occur within the glass matrix and the influence of atomic species migration forced by the femtosecond laser writing beam. In particular, we concentrate on borosilicate, heavy metal fluoride and phosphate glasses. We believe that our results represent an important step towards the development of engineered glass types that are ideally suited for the fabrication of photonic devices via the femtosecond laser direct write technique.

  19. Evaluation of the surface strength of glass plates shaped by hot slumping process

    Science.gov (United States)

    Proserpio, Laura; Basso, Stefano; Borsa, Francesco; Citterio, Oberto; Civitani, Marta; Ghigo, Mauro; Pareschi, Giovanni; Salmaso, Bianca; Sironi, Giorgia; Spiga, Daniele; Tagliaferri, Gianpiero; D'Este, Alberto; Dall'Igna, Roberto; Silvestri, Mirko; Parodi, Giancarlo; Martelli, Francesco; Bavdaz, Marcos; Wille, Eric

    2014-08-01

    Hot slumping technology is under development by several research groups in the world for the realization of grazing-incidence segmented mirrors for x-ray astronomy, based on thin glass plates shaped over a mold at temperatures above the transformation point. The performed thermal cycle and related operations might have effects on the strength of the glass, with consequences for the structural design of the elemental optical modules and, consequently, on the entire x-ray optic for large astronomical missions such as IXO and ATHENA. The mechanical strength of glass plates after they underwent the slumping process was tested through destructive double-ring tests in the context of a study performed by the Astronomical Observatory of Brera with the collaboration of Stazione Sperimentale del Vetro and BCV Progetti. The entire study was done on more than 200 D263 Schott borosilicate glass specimens of dimensions 100 mm×100 mm and a thickness 0.4 mm, either flat or bent at a radius of curvature of 1000 mm through the pressure-assisted hot slumping process developed by INAF-OAB. The collected experimental data have been compared with nonlinear finite element model analyses and treated with the Weibull statistic to assess the current IXO glass x-ray telescope design, in terms of survival probability, when subjected to static and acoustic loads characteristic of the launch phase. The paper describes the activities performed and presents the obtained results.

  20. Synthesis, IR, crystallization and dielectric study of (Pb, Sr)TiO3 borosilicate glass–ceramics

    Indian Academy of Sciences (India)

    C R Gautam; D Kumar; O Parkash; Prabhakar Singh

    2013-06-01

    Eleven glass compositions were prepared by melt and quench method with progressive substitution of SrO for PbO (0 ≤ ≤ 1.0) with a step-wise increment of 0.10 in the glass [(PbSr1−)OTiO2]–[(2SiO2B2O3)]–[BaO.K2O].Nb2O5 (mol percentage) system. The infrared spectra (IR) of various glass compositions in the above mentioned glass system was recorded over a continuous spectral range 400–4000 cm-1 to study their different oxides structure systematically. Differential thermal analysis (DTA) was recorded from room temperature (∼27 °C) to 1400 °C employing a heating rate of 10 °C/min to determine glass transition temperature, g and crystallization temperature, c. The melting temperature, m, of these glass compositions was found to be in the range 597–1060 °C depending on the composition under normal atmospheric conditions. g and m of glasses were found to increase with increasing SrO content. X-ray diffraction analysis of these glass–ceramic samples shows that major crystalline phase of the glass–ceramic sample with ≤ 0.5 was found to have cubic structure similar to SrTiO3 ceramic. Scanning electron microscopy has been carried out to see the surface morphology of the crystallites dispersed in the glassy matrix.

  1. Gust response of aeroelastically tailored wind turbines

    Science.gov (United States)

    Scott, S.; Capuzzi, M.; Langston, D.; Bossanyi, E.; McCann, G.; Weaver, PM; Pirrera, A.

    2016-09-01

    Some interesting challenges arise from the drive to build larger, more durable rotors that produce cheaper energy. The rationale is that, with current wind turbine designs, the power generated is theoretically proportional to the square of blade length. One enabling technology is aeroelastic tailoring that offers enhanced combined energy capture and system durability. The design of two adaptive, aeroelastically tailored blade configurations is considered here. One uses material bend-twist coupling; the other combines both material and geometric coupling. Each structural design meets a predefined coupling distribution, whilst approximately matching the stiffness of an uncoupled baseline blade. A gust analysis shows beneficial flapwise load alleviation for both adaptive blades, with the additional benefits of smoothing variations in electrical power and rotational speed.

  2. All-optical bandwidth-tailorable radar

    CERN Document Server

    Zou, Weiwen; Long, Xin; Zhang, Siteng; Cui, Yuanjun; Chen, Jianping

    2015-01-01

    Radar has been widely used in military, security, and rescue. Metamaterial cloak is employed in stealth targets to evade radar detection. Hence modern radar should be reconfigurable at multi-bands for detecting stealth targets, which might be realized based on microwave photonics. Here, we demonstrate an all-optical bandwidth-tailorable radar architecture. It is a coherent system utilizing one mode-locked laser for both signal generation and reception. Heterodyning of two individually filtered optical pulses that are pre-chirped via wavelength-to-time mapping generates wideband linearly-chirped radar signal. The working bands can be flexibly tailored with desired bandwidth at user-preferred carrier frequency. After modulated onto the pre-chirped optical pulse, radar echoes are time-stretched and frequency-compressed by several times. The digitization becomes much easier without loss of detection ability. We believe that the demonstration can innovate the radar's architecture with ultra-high range resolution.

  3. Metamaterials with tailored nonlinear optical response.

    Science.gov (United States)

    Husu, Hannu; Siikanen, Roope; Mäkitalo, Jouni; Lehtolahti, Joonas; Laukkanen, Janne; Kuittinen, Markku; Kauranen, Martti

    2012-02-08

    We demonstrate that the second-order nonlinear optical response of noncentrosymmetric metal nanoparticles (metamolecules) can be efficiently controlled by their mutual ordering in an array. Two samples with minor change in ordering have nonlinear responses differing by a factor of up to 50. The results arise from polarization-dependent plasmonic resonances modified by long-range coupling associated with metamolecular ordering. The approach opens new ways for tailoring the nonlinear responses of metamaterials and their tensorial properties.

  4. Tailored Training in Vehicle Maintenance Courses

    Science.gov (United States)

    2014-07-01

    G. A., Wampler, R. L., & Dyer, J. L. (2007). Techniques and practices in the training of digital operator skills . (Research Report 1878...occur in technical, functional courses where graduates must be proficient in clearly defined skills , based on specified performance standards, upon...tailored training in the Army is most likely to occur in technical, functional courses where graduates must be proficient in clearly defined skills

  5. Lay Health Influencers: How They Tailor Brief Tobacco Cessation Interventions

    Science.gov (United States)

    Yuan, Nicole P.; Castaneda, Heide; Nichter, Mark; Nichter, Mimi; Wind, Steven; Carruth, Lauren; Muramoto, Myra

    2012-01-01

    Interventions tailored to individual smoker characteristics have increasingly received attention in the tobacco control literature. The majority of tailored interventions are generated by computers and administered with printed materials or web-based programs. The purpose of this study was to examine the tailoring activities of community lay…

  6. Medical imaging scintillators from glass-ceramics using mixed rare-earth halides

    Science.gov (United States)

    Beckert, M. Brooke; Gallego, Sabrina; Ding, Yong; Elder, Eric; Nadler, Jason H.

    2016-10-01

    Recent years have seen greater interest in developing new luminescent materials to replace scintillator panels currently used in medical X-ray imaging systems. The primary areas targeted for improvement are cost and image resolution. Cost reduction is somewhat straightforward in that less expensive raw materials and processing methods will yield a less expensive product. The path to improving image resolution is more complex because it depends on several properties of the scintillator material including density, transparency, and composition, among others. The present study focused on improving image resolution using composite materials, known as glass-ceramics that contain nanoscale scintillating crystallites formed within a transparent host glass matrix. The small size of the particles and in-situ precipitation from the host glass are key to maintaining transparency of the composite scintillator, which ensures that a majority of the light produced from absorbed X-rays can actually be used to create an image of the patient. Because light output is the dominating property that determines the image resolution achievable with a given scintillator, it was used as the primary metric to evaluate performance of the glass-ceramics relative to current scintillators. Several glass compositions were formulated and then heat treated in a step known as "ceramization" to grow the scintillating nanocrystals, whose light output was measured in response to a 65 kV X-ray source. Performance was found to depend heavily on the thermal history of the glass and glass-ceramic, and so additional studies are required to more precisely determine optimal process temperatures. Of the compositions investigated, an alumino-borosilicate host glass containing 56mol% scintillating rare-earth halides (BaF2, GdF3, GdBr3, TbF3) produced the highest recorded light output at nearly 80% of the value recorded using a commercially-available GOS:Tb panel as a reference.

  7. The effect of boron oxide on the composition, structure, and adsorptivity of glass surfaces

    Science.gov (United States)

    Schaut, Robert A.

    Boron oxide has been added to commercial silicate glasses for many years to aid in lowering melting temperatures, lowering thermal expansion, and controlling chemical durability. The fact that simple borate glasses have rather high thermal expansion and low chemical durability attests to the unique influence of boron oxide additions upon the properties of silicate glasses. However, the impact of boron oxide additions upon surface properties of multicomponent borosilicates such as adsorption and reactivity is not yet well understood. In particular, the presence of multiple coordination states for boron is expected to introduce adsorption sites with different acidic or basic behavior, but their existence is yet unproven. To investigate these effects, multicomponent sodium aluminosilicate glasses have been prepared with varying sodium and boron concentrations and drawn into moderately high-surface-area continuous filament fibers. A relatively new technique, boron K-edge Near-Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy is applied to study the local boron coordination at fracture and melt-derived fiber surfaces of these glasses. This structural information is combined with surface compositional information by X-ray Photoelectron Spectroscopy (XPS) to characterize the local atomic structure of boron at the as-formed glass surface. Finally, this information is used to interpret the adsorptivity of these as-formed and leached surfaces toward short-chain alcohol molecules through a new Inverse Gas Chromatography---Temperature Programmed Desorption (IGC-TPD) experiment. The results clearly show that boron additions to alkali-free glass surfaces introduce a unique adsorption site which is not present on boron-free glass surfaces and is easily removed by leaching in acidic solutions.

  8. Biocompatible glass-ceramic materials for bone substitution.

    Science.gov (United States)

    Vitale-Brovarone, Chiara; Verné, Enrica; Robiglio, Lorenza; Martinasso, Germana; Canuto, Rosa A; Muzio, Giuliana

    2008-01-01

    A new bioactive glass composition (CEL2) in the SiO(2)-P(2)O(5)-CaO-MgO-K(2)O-Na(2)O system was tailored to control pH variations due to ion leaching phenomena when the glass is in contact with physiological fluids. CEL2 was prepared by a traditional melting-quenching process obtaining slices that were heat-treated to obtain a glass-ceramic material (CEL2GC) that was characterized thorough SEM analysis. Pre-treatment of CEL2GC with SBF was found to enhance its biocompatibility, as assessed by in vitro tests. CEL2 powder was then used to synthesize macroporous glass-ceramic scaffolds. To this end, CEL2 powders were mixed with polyethylene particles within the 300-600 microm size-range and then pressed to obtain crack-free compacted powders (green). This was heat-treated to remove the organic phase and to sinter the inorganic phase, leaving a porous structure. The biomaterial thus obtained was characterized by X-ray diffraction, SEM equipped with EDS, density measurement, image analysis, mechanical testing and in vitro evaluation, and found to be a glass-ceramic macroporous scaffold with uniformly distributed and highly interconnected porosity. The extent and size-range of the porosity can be tailored by varying the amount and size of the polyethylene particles.

  9. lead glass brick

    CERN Multimedia

    When you look through the glass at a picture behind, the picture appears raised up because light is slowed down in the dense glass. It is this density (4.06 gcm-3) that makes lead glass attractive to physicists. The refractive index of the glass is 1.708 at 400nm (violet light), meaning that light travels in the glass at about 58% its normal speed. At CERN, the OPAL detector uses some 12000 blocks of glass like this to measure particle energies.

  10. Glasses for immobilization of low- and intermediate-level radioactive waste

    Science.gov (United States)

    Laverov, N. P.; Omel'yanenko, B. I.; Yudintsev, S. V.; Stefanovsky, S. V.; Nikonov, B. S.

    2013-03-01

    Reprocessing of spent nuclear fuel (SNF) for recovery of fissionable elements is a precondition of long-term development of nuclear energetics. Solution of this problem is hindered by the production of a great amount of liquid waste; 99% of its volume is low- and intermediate-level radioactive waste (LILW). The volume of high-level radioactive waste (HLW), which is characterized by high heat release, does not exceed a fraction of a percent. Solubility of glasses at an elevated temperature makes them unfit for immobilization of HLW, the insulation of which is ensured only by mineral-like matrices. At the same time, glasses are a perfect matrix for LILW, which are distinguished by low heat release. The solubility of borosilicate glass at a low temperature is so low that even a glass with relatively low resistance enables them to retain safety of under-ground LILW depositories without additional engineering barriers. The optimal technology of liquid confinement is their concentration and immobilization in borosilicate glasses, which are disposed in shallow-seated geological repositories. The vitrification of 1 m3 liquid LILW with a salt concentration of ˜300 kg/m3 leaves behind only 0.2 m3 waste, that is, 4-6 times less than by bitumen impregnation and 10 times less than by cementation. Environmental and economic advantages of LILW vitrification result from (1) low solubility of the vitrified LILW in natural water; (2) significant reduction of LILW volume; (3) possibility to dispose the vitrified waste without additional engineering barriers under shallow conditions and in diverse geological media; (4) the strength of glass makes its transportation and storage possible; and finally (5) reliable longterm safety of repositories. When the composition of the glass matrix for LILW is being chosen, attention should be paid to the factors that ensure high technological and economic efficiency of vitrification. The study of vitrified LILW from the Kursk nuclear power plant

  11. Radiopaque Strontium Fluoroapatite Glass-Ceramics

    Science.gov (United States)

    Höland, Wolfram; Schweiger, Marcel; Dittmer, Marc; Ritzberger, Christian

    2015-01-01

    expansion (CTE). These glass-ceramics allow optical properties, especially the translucency and color, to be tailored to the needs of biomaterials for dental applications. The authors conclude that it is possible to use twofold crystallization processes to develop glass-ceramic biomaterials featuring different properties, such as specific radiopacity values, CTEs, and optical characteristics. PMID:26528470

  12. Radiopaque Strontium Fluoroapatite Glass-Ceramics.

    Science.gov (United States)

    Höland, Wolfram; Schweiger, Marcel; Dittmer, Marc; Ritzberger, Christian

    2015-01-01

    glass-ceramics allow optical properties, especially the translucency and color, to be tailored to the needs of biomaterials for dental applications. The authors conclude that it is possible to use twofold crystallization processes to develop glass-ceramic biomaterials featuring different properties, such as specific radiopacity values, CTEs, and optical characteristics.

  13. The performance of Inconel 693 electrodes for processing an iron phosphate glass melt containing 26 wt.% of a simulated low activity waste

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Jen-Hsien; Newkirk, Joseph W. [Department of Material Science and Engineering, Missouri University of Science and Technology, 101 Straumanis-James Hall 401 W. 16th St., Rolla, MO 65409-0330 (United States); Kim, Cheol-Woon [MO-SCI Corporation, 4040 HyPoint North, Rolla, MO 65401 (United States); Brow, Richard K., E-mail: brow@mst.edu [Department of Material Science and Engineering, Missouri University of Science and Technology, 101 Straumanis-James Hall 401 W. 16th St., Rolla, MO 65409-0330 (United States); Schlesinger, Mark E.; Ray, Chandra S.; Day, Delbert E. [Department of Material Science and Engineering, Missouri University of Science and Technology, 101 Straumanis-James Hall 401 W. 16th St., Rolla, MO 65409-0330 (United States)

    2014-01-15

    Iron phosphate glass is a candidate fixation medium for storing radioactive waste. The Department of Energy supported a program to assess the viability of using Fe-phosphate glass for vitrifying low activity waste in a Joule Heated Melter (JHM). In this study, Inconel 693 electrodes were tested in a research-scale joule-heated melter (RSM) at Pacific Northwest National Laboratory. After a 10-day test at 1030 °C that yielded 124 kg of glass, the electrodes exhibited a dimensional loss rate of ∼1.6 mm/year, which is comparable to that of Inconel 690 electrodes used in a JHM for processing borosilicate melts. Microstructural changes occurred within the outermost 700 μm of the electrodes and are consistent with an earlier study of Inconel coupons in Fe-phosphate melts. The results indicate that Inconel 693 should have an acceptable corrosion resistance as the electrode for JHM processing of iron phosphate melts.

  14. Preparation and characterization of novel glass-ceramic tile with microwave absorption properties from iron ore tailings

    Science.gov (United States)

    Yao, Rui; Liao, SongYi; Dai, ChangLu; Liu, YuChen; Chen, XiaoYu; Zheng, Feng

    2015-03-01

    A novel glass-ceramic tile consisting of one glass-ceramic layer (GC) attaining microwave absorption properties atop ceramic substrate was prepared through quench-heat treatment route derived from iron ore tailings (IOTs) and commercial raw materials (purity range 73-99%). X-ray diffraction (XRD), SEM, Energy dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), Physical property measurement system (PPMS) and Vector network analyzer (VNA) measurements were carried out to investigate phase, microstructure, magnetic and microwave absorption aspects of the glass-ceramic layer. Roughly 80.6±1.7 wt% borosilicate glass and 19.4±1.7 wt% spinel ferrite with chemical formula of (Zn2+0.17Fe3+0.83)[Fe3+1.17Fe2+0.06Ni2+0.77]O4 were found among the tested samples. Absorption of Electromagnetic wave by 3 mm thick glass-ceramic layer at frequency of 2-18 GHz reached peak reflection loss (RL) of -17.61 dB (98.27% microwave absorption) at 10.31 GHz. Altering the thickness of the glass-ceramic layer can meet the requirements of different level of microwave absorption.

  15. Tunable integrated optical filter made of a glass ion-exchanged waveguide and an electro-optic composite holographic grating.

    Science.gov (United States)

    d'Alessandro, Antonio; Donisi, Domenico; De Sio, Luciano; Beccherelli, Romeo; Asquini, Rita; Caputo, Roberto; Umeton, Cesare

    2008-06-23

    We report the fabrication and the optical characterization of a hybrid tunable integrated optical filter. It consists of a diffused ion-exchanged channel waveguide on a borosilicate glass substrate with a cover of the same glass to form a gap filled with a holographic grating. The grating morphology, called POLICRYPS (POlymer LIquid CRYstal Polymer Slices), is made of alternating stripes of polymer and liquid crystal acting as overlayer for the underneath waveguide. The filter structure includes aluminum coplanar electrodes to electrically control the grating properties, allowing the tunability of the filter. The electric driving power required to tune the filter obtained was in the range of submilliwatts due to the efficient liquid crystal electro-optic effect.

  16. Nonlinear Optical Properties and Femtosecond Laser Micromachining of Special Glasses

    OpenAIRE

    Almeida,Juliana M. P.; Gustavo F. B. Almeida; Boni, Leonardo De; Cleber R. Mendonça

    2015-01-01

    Materials specially designed for photonics have been at the vanguard of chemistry, physics and materials science, driven by the development of new technologies. One particular class of materials investigated in this context are glasses, that in principle should exhibit high third order optical nonlinearities and fast response time, whose optical properties can be tailored by compositional changes, such as, for instance, the incorporation of metallic nanoparticles to explore plasmon resonances...

  17. Tailored antireflective biomimetic nanostructures for UV applications

    Energy Technology Data Exchange (ETDEWEB)

    Morhard, Christoph; Pacholski, Claudia; Spatz, Joachim P [Department of New Materials and Biosystems, Max Planck Institute for Metals Research, Heisenbergstrasse 3, D-70569 Stuttgart (Germany); Lehr, Dennis; Brunner, Robert; Helgert, Michael [Carl Zeiss Jena GmbH, Technology Center, Carl-Zeiss-Promenade 10, D-07745 Jena (Germany); Sundermann, Michael, E-mail: Pacholski@mf.mpg.de [Carl Zeiss Jena GmbH, Technology Center, Carl-Zeiss-Strasse 56, D-73447 Oberkochen (Germany)

    2010-10-22

    Antireflective surfaces composed of biomimetic sub-wavelength structures that employ the 'moth eye principle' for reflectance reduction are highly desirable in many optical applications such as solar cells, photodetectors and laser optics. We report an efficient approach for the fabrication of antireflective surfaces based on a two-step process consisting of gold nanoparticle mask generation by micellar block copolymer nanolithography and a multi-step reactive ion etching process. Depending on the RIE process parameters nanostructured surfaces with tailored antireflective properties can easily be fabricated that show optimum performance for specific applications.

  18. Microstructuring of glasses

    CERN Document Server

    Hülsenberg, Dagmar; Bismarck, Alexander

    2008-01-01

    As microstructured glass becomes increasingly important for microsystems technology, the main application fields include micro-fluidic systems, micro-analysis systems, sensors, micro-actuators and implants. And, because glass has quite distinct properties from silicon, PMMA and metals, applications exist where only glass devices meet the requirements. The main advantages of glass derive from its amorphous nature, the precondition for its - theoretically - direction-independent geometric structurability. Microstructuring of Glasses deals with the amorphous state, various glass compositions and their properties, the interactions between glasses and the electromagnetic waves used to modify it. Also treated in detail are methods for influencing the geometrical microstructure of glasses by mechanical, chemical, thermal, optical, and electrical treatment, and the methods and equipment required to produce actual microdevices.

  19. Toward Molecular Engineering of Polymer Glasses

    Energy Technology Data Exchange (ETDEWEB)

    Freed, Karl F [Univ. of Chicago, IL (United States); Xu, Wen-Sheng [Univ. of Chicago, IL (United States); Dudowicz, Jacek B [Univ. of Chicago, IL (United States); Douglas, Jack F [National Inst. of Standards and Technology (NIST), Boulder, CO (United States)

    2017-04-05

    Glass formation has been central to fabrication technologies since the dawn of civilization. Glasses not only encompass window panes, the insulation in our homes, the optical fibers supplying our cable TV, and vessels for eating and drinking, but they also include a vast array of ‘‘plastic’’ polymeric materials. Glasses find applications in high technology (e.g., producing microelectronic materials, etc., amorphous semiconductors), and recent advances have created ‘‘plastic metallic glasses’’ that are promising for fabricating everyday structural materials. Many commercially relevant systems, such as microemulsions and colloidal suspensions, have complex molecular structures and thus solidify by glass formation. Despite the importance of understanding the fundamental nature of glass formation for the synthesis of new materials, a predictive molecular theory has been lacking. Much of our understanding of glass formation derives from the analysis of experimental data, a process that has uncovered a number of interesting universal behaviors, namely, relations between properties that are independent of molecular details. However, these empirically derived relations and their limitations remain to be understood on the basis of theories, and, more importantly, there is strong need for theories of the explicit variation with molecular system to enable the rational design and tailoring of new materials. We have recently developed the generalized entropy theory, the only analytic, theory that enables describing the dependence of the properties of glass-formation on monomer molecular structures. These properties include the two central quantities of glass formation, the glass transition temperature and the glass fragility parameter, material dependent properties that govern how a material may be processed (e.g., by extrusion, ink jet, molding, etc.) Our recent works, which are further described below, extend the studies of glass formation in polymer systems

  20. Glass-clad semiconductor core optical fibers

    Science.gov (United States)

    Morris, Stephanie Lynn

    Glass-clad optical fibers comprising a crystalline semiconductor core have garnered considerable recent attention for their potential utility as novel waveguides for applications in nonlinear optics, sensing, power delivery, and biomedicine. As research into these fibers has progressed, it has become evident that excessive losses are limiting performance and so greater understanding of the underlying materials science, coupled with advances in fiber processing, is needed. More specifically, the semiconductor core fibers possess three performance-limiting characteristics that need to be addressed: (a) thermal expansion mismatches between crystalline core and glass cladding that lead to cracks, (b) the precipitation of oxide species in the core upon fiber cooling, which results from partial dissolution of the cladding glass by the core melt, and (c) polycrystallinity; all of which lead to scattering and increased transmission losses. This dissertation systematically studies each of these effects and develops both a fundamental scientific understanding of and practical engineering methods for reducing their impact. With respect to the thermal expansion mismatch and, in part, the dissolution of oxides, for the first time to our knowledge, oxide and non-oxide glass compositions are developed for a series of semiconductor cores based on two main design criteria: (1) matching the thermal expansion coefficient between semiconductor core and glass cladding to minimize cracking and (2) matching the viscosity-temperature dependences, such that the cladding glass draws into fiber at a temperature slightly above the melting point of the semiconductor in order to minimize dissolution and improve the fiber draw process. The x[Na 2O:Al2O3] + (100 - 2x)SiO2 glass compositional family was selected due to the ability to tailor the glass properties to match the aforementioned targets through slight variations in composition and adjusting the ratios of bridging and non-bridging oxygen

  1. Laser cutting of sheets for Tailored Blanks

    DEFF Research Database (Denmark)

    Bagger, Claus; Olsen, Flemming Ove

    1999-01-01

    Over the past few years there has been an enormous increase in the use of tailored blanks, especially in the automotive industry. Often the sheets for tailored blanks are shear cut, but results have been reported that the allowable sheet gap distance should not exceed 0.1 mm in order to obtain...... sound welds. Laser cutting the sheets may therefore be an alternative to shear cutting, if the cut kerf squareness can be kept below 0.05 mm.In a number of systematic laboratory experiments the effects of the major process parameters in laser cutting have been investigated. Each cut was quantified...... by the squareness, the surface roughness and the burr height. Mild steel as well as high strength steel with and with out galvanisation with thickness' of 0.7(5) and 1.25 were used.In the tests the difference in cut quality between a 5" and a 7.5" focusing lens were tested and the effect of using pulsed mode laser...

  2. SUMMARY OF FY11 SULFATE RETENTION STUDIES FOR DEFENSE WASTE PROCESSING FACILITY GLASS

    Energy Technology Data Exchange (ETDEWEB)

    Fox, K.; Edwards, T.

    2012-05-08

    This report describes the results of studies related to the incorporation of sulfate in high level waste (HLW) borosilicate glass produced at the Savannah River Site (SRS) Defense Waste Processing Facility (DWPF). A group of simulated HLW glasses produced for earlier sulfate retention studies was selected for full chemical composition measurements to determine whether there is any clear link between composition and sulfate retention over the compositional region evaluated. In addition, the viscosity of several glasses was measured to support future efforts in modeling sulfate solubility as a function of predicted viscosity. The intent of these studies was to develop a better understanding of sulfate retention in borosilicate HLW glass to allow for higher loadings of sulfate containing waste. Based on the results of these and other studies, the ability to improve sulfate solubility in DWPF borosilicate glasses lies in reducing the connectivity of the glass network structure. This can be achieved, as an example, by increasing the concentration of alkali species in the glass. However, this must be balanced with other effects of reduced network connectivity, such as reduced viscosity, potentially lower chemical durability, and in the case of higher sodium and aluminum concentrations, the propensity for nepheline crystallization. Future DWPF processing is likely to target higher waste loadings and higher sludge sodium concentrations, meaning that alkali concentrations in the glass will already be relatively high. It is therefore unlikely that there will be the ability to target significantly higher total alkali concentrations in the glass solely to support increased sulfate solubility without the increased alkali concentration causing failure of other Product Composition Control System (PCCS) constraints, such as low viscosity and durability. No individual components were found to provide a significant improvement in sulfate retention (i.e., an increase of the magnitude

  3. The Production of Advanced Glass Ceramic HLW Forms using Cold Crucible Induction Melter

    Energy Technology Data Exchange (ETDEWEB)

    Veronica J Rutledge; Vince Maio

    2013-10-01

    Cold Crucible Induction Melters (CCIMs) will favorably change how High-Level radioactive Waste (from nuclear fuel recovery) is treated in the 21st century. Unlike the existing Joule-Heated Melters (JHMs) currently in operation for the glass-based immobilization of High-Level Waste (HLW), CCIMs offer unique material features that will increase melt temperatures, increase throughput, increase mixing, increase loading in the waste form, lower melter foot prints, eliminate melter corrosion and lower costs. These features not only enhance the technology for producing HLW forms, but also provide advantageous attributes to the waste form by allowing more durable alternatives to glass. This paper discusses advantageous features of the CCIM, with emphasis on features that overcome the historical issues with the JHMs presently utilized, as well as the benefits of glass ceramic waste forms over borosilicate glass waste forms. These advantages are then validated based on recent INL testing to demonstrate a first-of-a-kind formulation of a non-radioactive ceramic-based waste form utilizing a CCIM.

  4. Structural and optical properties of ZnSe quantum dots in glass nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Dey, Chirantan [Glass Science and Technology Section, Glass Division, CSIR – Central Glass and Ceramic Research Institute, 196, Raja S. C. Mullick Road, 700032 Kolkata (India); Goswami, Madhumita [Glass and Advanced Materials Division, Bhaba Atomic Research Centre, Trombay, 400085 Mumbai (India); Karmakar, Basudeb, E-mail: basudebk@cgcri.res.in [Glass Science and Technology Section, Glass Division, CSIR – Central Glass and Ceramic Research Institute, 196, Raja S. C. Mullick Road, 700032 Kolkata (India)

    2015-08-01

    Zinc selenide (ZnSe) quantum dots (QDs) were synthesized in a dielectric (borosilicate glass) matrix for the first time by melt-quenching process followed by thermal treatment. Sizes of the quantum dots were varied by post thermal treatment. UV–Vis optical absorption spectroscopy, transmission electron microscopy (TEM) and Raman spectroscopy were deployed to investigate the ZnSe QDs. TEM analysis reveals QD sizes of the order of 2–4 nm and relatively larger nanocrystals having sizes of the order of 15–26 nm. The sizes of the QDs have also been verified with the help of effective mass approximation model and optical absorption spectroscopy. The quantum confinement effect has been observed for both variation of heat treatment temperature and time. The Raman spectra of the nanocomposites reveal blue-shifted Raman peaks of ZnSe at 295 and 315 cm{sup −1} due to phonon confinement effect. The decrease in Raman intensity with heat treatment indicates increase in size of the QDs. Red luminescence from the ZnSe-glass nanocomposites peaking at 708 nm due to the size related as well as traps related states makes their applications towards luminescent solar concentrators (LSCs). - Highlights: • ZnSe quantum dots embedded glass-nanocomposites were synthesized. • Nanocrystal sizes were controlled by the heat treatment schedule. • Structure and optical properties of nano-sized ZnSe in glass were investigated. • Strong visible red photoluminescence was obtained from these nanocomposites.

  5. First-order model for durability of Hanford waste glasses as a function of composition

    Energy Technology Data Exchange (ETDEWEB)

    Hrma, P.; Piepel, G.F.; Schweiger, M.J.; Smith, D.E.

    1992-04-01

    Two standard chemical durability tests, the static leach test MCC-1 and product consistency test PCT, were conducted on simulated borosilicate glasses that encompass the expected range of compositions to be produced in the Hanford Waste Vitrification Plant (HWVP). A first-order empirical model was fitted to the data from each test method. The results indicate that glass durability is increased by addition of Al{sub 2}O{sub 3}, moderately increased by addition of ZrO{sub 2} and SiO{sub 2}, and decreased by addition of Li{sub 2}O, Na{sub 2}O, B{sub 2}O{sub 3}, and MgO. Addition of Fe{sub 2}O{sub 3} and CaO produce an indifferent or reducing effect on durability according to the test method. This behavior and a statistically significant lack of fit are attributed to the effects of multiple chemical reactions occurring during glass-water interaction. Liquid-liquid immiscibility is suspected to be responsible for extremely low durability of some glasses.

  6. Laser welding of glasses using a nanosecond pulsed Nd:YAG laser

    Science.gov (United States)

    de Pablos-Martín, A.; Höche, Th.

    2017-03-01

    This work reports on laser welding of two 1 mm thickness borosilicate glasses through the irradiation with a nanosecond pulsed laser, as a novel alternative to the use of ultrashort pulsed lasers for welding of transparent materials. Two different methodologies were investigated and compared in terms of interface quality. In a first approach, the glasses were joined without any absorbing intermediate layer. However, the bond interface possesses defects. To improve the resulting bond interface, the use of a titanium ultrathin intermediate layer was proposed to weld the glasses substrates, acting as a sealant between them. The laser parameters were optimized to achieve the best joining conditions of the Ti film. The use of the Ti layer gives rise to a bond interface more homogeneous and free of damages. As a further step, thin glasses of 86 μm thickness, of great technological value, were joined through the Ti film as well. The joined interfaces were inspected through optical microscopy and scanning electron microscopy (SEM) while the bond quality was evaluated by Scanning Acoustic Microscopy (SAM).

  7. Evaluation of the surface strength of glass plates shaped by hot slumping process

    CERN Document Server

    Proserpio, L; Borsa, F; Citterio, O; Civitani, M; Ghigo, M; Pareschi, G; Salmaso, B; Sironi, G; Spiga, D; Tagliaferri, G; D'Este, A; Dall'Igna, R; Silvestri, M; Parodi, G; Martelli, F; Bavdaz, M; Wille, E

    2014-01-01

    The Hot Slumping Technology is under development by several research groups in the world for the realization of grazing-incidence segmented mirrors for X-ray astronomy, based on thin glass plates shaped over a mould at temperatures above the transformation point. The performed thermal cycle and related operations might have effects on the strength characteristics of the glass, with consequences on the structural design of the elemental optical modules and consecutively on the entire X-ray optic for large astronomical missions like IXO and ATHENA. The mechanical strength of glass plates after they underwent the slumping process was tested through destructive double-ring tests in the context of a study performed by the Astronomical Observatory of Brera with the collaboration of Stazione Sperimentale del Vetro and BCV Progetti. The entire study has been realized on more than 200 D263 Schott borosilicate glass specimens of dimension 100 mm x 100 mm and thickness 0.4 mm, either flat or bent at a Radius of Curvatur...

  8. Femtosecond laser writing of Bragg grating waveguide bundles in bulk glass.

    Science.gov (United States)

    Thiel, Markus; Flachenecker, Günter; Schade, Wolfgang

    2015-04-01

    Waveguide bundles in bulk glass materials, consisting of several parallel scans of refractive index modifications, have been generated with a low-repetition femtosecond laser. Additionally, Bragg grating (BG) structures for 840 and 1550 nm have been introduced by segmentation of the central scan. A spectral loss in the transmission signal of >36  dB was achieved at 1550 nm with a second-order Bragg grating waveguide (BGW) in fused silica, which corresponds to an intrinsic grating efficiency of >16  dB/cm. This is to our knowledge the strongest BG structure realized in glass with a femtosecond laser. The BGW were proven to be stable up to a temperature of 250°C in fused silica. The diameter of the waveguide bundles can be adapted very easily for a broad range of wavelengths and have been demonstrated for diameters between 1 and 50 μm. The transmission properties of the waveguide bundles are affected minorly by the insertion of BG structures, which opens the ability for adjusting the BGW for a broad range of wavelength in single-mode or multimode optical circuits. BGW have been realized successfully in fused silica, borosilicate glass (BOROFLOAT 33), and AF 32 eco Thin Glass from Schott.

  9. Analysis of Optical and Morphological Properties of Aluminium Induced Texture Glass Superstrates

    Science.gov (United States)

    Wang, Juan; Venkataraj, Selvaraj; Battaglia, Corsin; Vayalakkara, Premachandran; Aberle, Armin G.

    2012-10-01

    Texturing the glass surface is a promising method for improving the light trapping properties of superstrate thin-film silicon solar cells, as it enables thinner absorber layers and, possibly, higher cell efficiencies. In this paper we present the optical and morphological properties of borosilicate glass superstrates textured with the aluminium induced texture (AIT) method. High haze values are achieved without any reduction in the total optical transmission of the glass sheets after the AIT process. Scanning electron microscope and atomic force microscope (AFM) measurements reveal a laterally uniform surface morphology of the AIT texture. We demonstrate that the surface roughness and thus the transmission haze can be controlled by adjusting the AIT process parameters. From the AFM images, we extract histograms of the local height and angle distributions of the texture. Samples with a wide angle distribution are shown to produce the highest optical haze. The results of this analysis provide a better understanding of the correlation between the AIT process parameters and the resulting surface morphology. This analysis is further extended to an amorphous silicon pin solar cell deposited onto the textured glass substrate.

  10. Development and modification of glass membranes for aggressive gas separations

    Energy Technology Data Exchange (ETDEWEB)

    Lindbraaten, Arne

    2004-07-01

    Chlorine as a chemical is widespread in industry and found in a great variety of processes ranging from water purification to plastic production. In this thesis, a magnesium production factory was chosen as an example because it involved both chlorine - air separation and hydrogen -hydrogen chloride separation. Previously, various types of membrane materials have been tested out for their applicability in the chosen process. The materials previously tested either lacked sufficient membrane performance or sufficient membrane stability. As an attempt to improve both the membrane performance and stability, glass membranes are used in this thesis. Glass membranes are prepared from a borosilicate glass, via a phase separation followed by an acid leaching route. By choosing the appropriate phase separation temperature and acid to glass ratio, the membrane can be produced with an average pore diameter of 2 nm (or 4 nm). However, the 2 nm average pore size is still too large to separate gases with separation selectivities beyond the selectivities predicted from Knudsen diffusion theory. If the pores are narrowed, the selectivity may be raised while the flux hopefully is maintained. The narrowing of the pores was done by a silane coupling to the surface OH-groups on the glass. The silane coupling agent is of the dimethyl-acyl-chlorosilane type, where the length of the acyl chain varies from 1 carbon up to 18 carbons. Glass fibres are also tested in this work, which are produced without phase separation and their average pore size is smaller than the surface-modified glasses. To be able to compare the performance of the various membranes, performance measurements are performed and these measurements are evaluated by the separation power (product of the selectivity and the permeability of the fastest permeating compound). Because of the harsh chlorine or hydrogen chloride environment, to which the membranes are exposed in this work, the membrane stability is at least as

  11. Comparison of glass vessels and plastic bags for enclosing living plant parts for headspace analysis.

    Science.gov (United States)

    Stewart-Jones, Alex; Poppy, Guy M

    2006-04-01

    Plants release volatile chemicals into their surrounding air space that can affect the physiology of neighboring plants and influence the behavior of insects. In studying these interactions, it is desirable to collect volatiles from plants that have not been excised and are growing under as natural conditions as possible. We compared a vessel of borosilicate glass and Nylon-6 or polyester [poly(ethyleneterephthalate) or PET] cooking bags for enclosing plants during collection of volatiles. A push-pull airflow system was used, and volatiles were trapped on Tenax TA and analyzed by gas chromatography after thermal desorption. Low levels of impurities were found for the glass vessel and polyester bags. Nylon bags contained higher levels and more impurities. Recoveries of standards of 10 plant volatiles were measured in static and dynamic systems. In a static air system, there was good recovery only from the glass vessel. In a dynamic system, there was generally good recovery from both the glass vessel and polyester bags. Recoveries of alpha-pinene and (Z)-jasmone were poor throughout. The former was shown to have a very low breakthrough volume on the Tenax TA adsorbent, and the latter may be strongly adsorbed on glass. All three materials were essentially transparent in the IR and visible (photosynthetic) range but with significantly different absorptions in the UV range. In a simulated dynamic entrainment in full sunlight, internal vessel temperatures were higher than ambient by up to 9.5 degrees C in the glass vessel and 7.5 degrees C in the polyester bag. Lower increases in temperature relative to ambient (bag were similar. Polyester bags are recommended as more convenient than glass vessels for the enclosure of plants during the collection of volatiles.

  12. Deep Drawing of High-Strength Tailored Blanks by Using Tailored Tools

    Directory of Open Access Journals (Sweden)

    Thomas Mennecart

    2016-01-01

    Full Text Available In most forming processes based on tailored blanks, the tool material remains the same as that of sheet metal blanks without tailored properties. A novel concept of lightweight construction for deep drawing tools is presented in this work to improve the forming behavior of tailored blanks. The investigations presented here deal with the forming of tailored blanks of dissimilar strengths using tailored dies made of two different materials. In the area of the steel blank with higher strength, typical tool steel is used. In the area of the low-strength steel, a hybrid tool made out of a polymer and a fiber-reinforced surface replaces the steel half. Cylindrical cups of DP600/HX300LAD are formed and analyzed regarding their formability. The use of two different halves of tool materials shows improved blank thickness distribution, weld-line movement and pressure distribution compared to the use of two steel halves. An improvement in strain distribution is also observed by the inclusion of springs in the polymer side of tools, which is implemented to control the material flow in the die. Furthermore, a reduction in tool weight of approximately 75% can be achieved by using this technique. An accurate finite element modeling strategy is developed to analyze the problem numerically and is verified experimentally for the cylindrical cup. This strategy is then applied to investigate the thickness distribution and weld-line movement for a complex geometry, and its transferability is validated. The inclusion of springs in the hybrid tool leads to better material flow, which results in reduction of weld-line movement by around 60%, leading to more uniform thickness distribution.

  13. Fluoride glass fiber optics

    CERN Document Server

    Aggarwal, Ishwar D

    1991-01-01

    Fluoride Glass Fiber Optics reviews the fundamental aspects of fluoride glasses. This book is divided into nine chapters. Chapter 1 discusses the wide range of fluoride glasses with an emphasis on fluorozirconate-based compositions. The structure of simple fluoride systems, such as BaF2 binary glass is elaborated in Chapter 2. The third chapter covers the intrinsic transparency of fluoride glasses from the UV to the IR, with particular emphasis on the multiphonon edge and electronic edge. The next three chapters are devoted to ultra-low loss optical fibers, reviewing methods for purifying and

  14. Prize for a Faculty Member for Research in an Undergraduate Institution Lecture: Studies of the Structure and Properties of Oxide Glasses with Applications

    Science.gov (United States)

    Affatigato, Mario

    2013-03-01

    This presentation will summarize the research work carried out by Prof. Affatigato and his undergraduate students over the past eighteen years. It will focus on some highlighted projects, namely: the determination of glass structure using laser ionization time of flight mass spectrometry; studies of glass modification by laser irradiation; bactericidal glass; and, most recently, glass manufacturing by aerolevitation and glasses for particle detection. The work on mass spectrometry will cover a broad range of oxide glass systems, including the borates, borosilicates, germanate, and gallate families. It has provided novel insights into the structure of glasses at intermediate length scales, measurements that are hard to obtain by any other techniques. The studies of glass structure modification will primarily center on vanadate glasses, which also form the basis for more recent electronic conductivity work at the heart of new particle calorimeter detectors. This project shows the power of serendipity and the strong capabilities of undergraduate students involved in advanced work and state of the art instrumentation. Bactericidal glass illustrates a nice collaborative project that involved simple borate glasses and helped pioneer their use in the human body--work that has led to significant medical developments by other colleagues and researchers. Finally, the aerolevitation project gives new insight into the crystallization and property behavior of glasses and melts at very high temperatures (from 2000 °C to 3000 °C). The work by Prof. Affatigato and his students has been supported by grants from the Research Corporation, the Petroleum Research Fund, and, primarily, by the U.S. National Science Foundation.

  15. INTERNATIONAL STUDY OF ALUMINUM IMPACTS ON CRYSTALLIZATION IN U.S. HIGH LEVEL WASTE GLASS

    Energy Technology Data Exchange (ETDEWEB)

    Fox, K; David Peeler, D; Tommy Edwards, T; David Best, D; Irene Reamer, I; Phyllis Workman, P; James Marra, J

    2008-09-23

    O{sub 2} in all glasses due to the low solubility of RuO{sub 2} in borosilicate glass. These particles tended to form agglomerates with varying sizes and shapes that were located close to the bottom of crucibles. The results of this study provide further insight into the ability of borosilicate waste glass to incorporate increased (>16 wt %) concentrations of aluminum. The glass composition and properties data will be incorporated into a database of glass composition-property relationships (ComPro) to support further optimization of waste glass compositions at DOE sites.

  16. Development of lightweight, glass mirror segments for the Large Deployable Reflector

    Science.gov (United States)

    Melugin, R. K.; Miller, J. H.; Angel, J. R. P.; Wangsness, P. A. A.; Parks, R. E.

    1986-01-01

    Accomplishments in the development of lightweight, honeycomb-core, sandwich mirror blanks made of borosilicate and high-silica glasses at the University of Arizona for the Large Deployable Reflector program are described. In this paper, work spanning the last 2 years is reported, highlighting a new mirror blank fabrication technique that permits the fabrication of the honeycomb core integrally with the front and back plates of the blank in a single furnace cycle. Two types of mirror blanks made by this method, an off-axis, aspheric segment and a smaller Vycor circular piece, are described. The fabrication of two off-axis, aspheric mirror segments is also described. Cryogenic test results are included on the test of a 38-cm diameter, lightweight, honeycomb core, sandwich mirror made of Pyrex.

  17. Synthesis of Glass Nanofibers Using Femtosecond Laser Radiation Under Ambient Condition

    Directory of Open Access Journals (Sweden)

    Venkatakrishnan K

    2009-01-01

    Full Text Available Abstract We report the unique growth of nanofibers in silica and borosilicate glass using femtosecond laser radiation at 8 MHz repetition rate and a pulse width of 214 fs in air at atmospheric pressure. The nanofibers are grown perpendicular to the substrate surface from the molten material in laser-drilled microvias where they intertwine and bundle up above the surface. The fibers are few tens of nanometers in thickness and up to several millimeters in length. Further, it is found that at some places nanoparticles are attached to the fiber surface along its length. Nanofiber growth is explained by the process of nanojets formed in the molten liquid due to pressure gradient induced from the laser pulses and subsequently drawn into fibers by the intense plasma pressure. The attachment of nanoparticles is due to the condensation of vapor in the plasma.

  18. Low Velocity Sphere Impact of a Soda Lime Silicate Glass

    Energy Technology Data Exchange (ETDEWEB)

    Wereszczak, Andrew A [ORNL; Fox, Ethan E [ORNL; Morrissey, Timothy G [ORNL; Vuono, Daniel J [ORNL

    2011-10-01

    This report summarizes TARDEC-sponsored work at Oak Ridge National Laboratory (ORNL) during the FY11 involving low velocity (< 30 m/s or < 65 mph) ball impact testing of Starphire soda lime silicate glass. The intent was to better understand low velocity impact response in the Starphire for sphere densities that bracketed that of rock. Five sphere materials were used: borosilicate glass, soda-lime silicate glass, steel, silicon nitride, and alumina. A gas gun was fabricated to produce controlled velocity delivery of the spheres against Starphire tile targets. Minimum impact velocities to initiate fracture in the Starphire were measured and interpreted in context to the kinetic energy of impact and the elastic property mismatch between the any of the five sphere-Starphire-target combinations. The primary observations from this low velocity (< 30 m/s or < 65 mph) testing were: (1) Frictional effects contribute to fracture initiation. (2) Spheres with a lower elastic modulus require less force to initiate fracture in the Starphire than spheres with a higher elastic modulus. (3) Contact-induced fracture did not initiate in the Starphire SLS for impact kinetic energies < 150 mJ. Fracture sometimes initiated or kinetic energies between {approx} 150-1100 mJ; however, it tended to occur when lower elastic modulus spheres were impacting it. Contact-induced fracture would always occur for impact energies > 1100 mJ. (4) The force necessary to initiate contact-induced fracture is higher under dynamic or impact conditions than it is under quasi-static indentation conditions. (5) Among the five used sphere materials, silicon nitride was the closest match to 'rock' in terms of both density and (probably) elastic modulus.

  19. SON68 glass dissolution driven by magnesium silicate precipitation

    Science.gov (United States)

    Fleury, Benjamin; Godon, Nicole; Ayral, André; Gin, Stéphane

    2013-11-01

    Experimental results are reported on the effect of magnesium silicate precipitation on the mechanisms and rate of borosilicate glass dissolution. Leaching experiments with SON68 glass, a borosilicate containing no Mg, were carried out in initially deionized water at 50 °C with a glass-surface-area-to-solution-volume ratio of 20,000 m-1. After 29 days of alteration the experimental conditions were modified by the addition of Mg to trigger the precipitation of Mg-silicate. Additional experiments were conducted to investigate the importance of other parameters such as pH or dissolved silica on the mechanisms of precipitation of Mg-silicates and their consequences on the glass dissolution rate. Mg-silicates precipitate immediately after Mg is added. The amount of altered glass increases with the quantity of added Mg, and is smaller when silicon is added in solution. A time lag is observed between the addition of magnesium and the resumption of glass alteration because silicon is first provided by partial dissolution of the previously formed alteration gel. It is shown that nucleation does not limit Mg-silicate precipitation. A pH above 8 is necessary for the phase to precipitate under the investigated experimental conditions. On the other hand the glass alteration kinetics limits the precipitation if the magnesium is supplied in solution at a non-limiting rate. The concentration of i in solution was analyzed as well as that of boron. The quantity of i released from the glass is estimated with the assumption that i and B are released congruently at the glass dissolution front. The remained quantity of the element i is then supposed to be in the gel or in the secondary phase. In this paper, we do not make a difference between gel and hydrated glass using the same word 'gel' whereas Gin et al. [40] makes this difference. Recent papers [40,41] discussed about different key issues related to the passivation properties of the alteration layer including the hydrated glass

  20. Tailoring superradiance to design artificial quantum systems

    Science.gov (United States)

    Longo, Paolo; Keitel, Christoph H.; Evers, Jörg

    2016-03-01

    Cooperative phenomena arising due to the coupling of individual atoms via the radiation field are a cornerstone of modern quantum and optical physics. Recent experiments on x-ray quantum optics added a new twist to this line of research by exploiting superradiance in order to construct artificial quantum systems. However, so far, systematic approaches to deliberately design superradiance properties are lacking, impeding the desired implementation of more advanced quantum optical schemes. Here, we develop an analytical framework for the engineering of single-photon superradiance in extended media applicable across the entire electromagnetic spectrum, and show how it can be used to tailor the properties of an artificial quantum system. This “reverse engineering” of superradiance not only provides an avenue towards non-linear and quantum mechanical phenomena at x-ray energies, but also leads to a unified view on and a better understanding of superradiance across different physical systems.

  1. Tailored Patient Information Some Issues and Questions

    CERN Document Server

    Reiter, E R; Reiter, Ehud; Osman, Liesl

    1997-01-01

    Tailored patient information (TPI) systems are computer programs which produce personalised heath-information material for patients. TPI systems are of growing interest to the natural-language generation (NLG) community; many TPI systems have also been developed in the medical community, usually with mail-merge technology. No matter what technology is used, experience shows that it is not easy to field a TPI system, even if it is shown to be effective in clinical trials. In this paper we discuss some of the difficulties in fielding TPI systems. This is based on our experiences with 2 TPI systems, one for generating asthma-information booklets and one for generating smoking-cessation letters.

  2. Tailoring Accelerating Beams in Phase Space

    CERN Document Server

    Wen, Yuanhui; Zhang, Yanfeng; Chen, Hui; Yu, Siyuan

    2016-01-01

    An appropriate design of wavefront will enable light fields propagating along arbitrary trajectories thus forming accelerating beams in free space. Previous ways of designing such accelerating beams mainly rely on caustic methods, which start from diffraction integrals and only deal with two-dimensional fields. Here we introduce a new perspective to construct accelerating beams in phase space by designing the corresponding Wigner distribution function (WDF). We find such a WDF-based method is capable of providing both the initial field distribution and the angular spectrum in need by projecting the WDF into the real space and the Fourier space respectively. Moreover, this approach applies to the construction of both two- and three-dimensional fields, greatly generalizing previous caustic methods. It may therefore open up a new route to construct highly-tailored accelerating beams and facilitate applications ranging from particle manipulation and trapping to optical routing as well as material processing.

  3. Tailoring superradiance to design artificial quantum systems.

    Science.gov (United States)

    Longo, Paolo; Keitel, Christoph H; Evers, Jörg

    2016-03-24

    Cooperative phenomena arising due to the coupling of individual atoms via the radiation field are a cornerstone of modern quantum and optical physics. Recent experiments on x-ray quantum optics added a new twist to this line of research by exploiting superradiance in order to construct artificial quantum systems. However, so far, systematic approaches to deliberately design superradiance properties are lacking, impeding the desired implementation of more advanced quantum optical schemes. Here, we develop an analytical framework for the engineering of single-photon superradiance in extended media applicable across the entire electromagnetic spectrum, and show how it can be used to tailor the properties of an artificial quantum system. This "reverse engineering" of superradiance not only provides an avenue towards non-linear and quantum mechanical phenomena at x-ray energies, but also leads to a unified view on and a better understanding of superradiance across different physical systems.

  4. [Tailor-made strategy in HCV treatment].

    Science.gov (United States)

    Watanabe, Tsunamasa; Tanaka, Yasuhito

    2012-04-01

    Hepatitis C virus (HCV) infection is a global health problem and a leading cause of end-stage liver disease and hepatocellular carcinoma. Treatment of HCV infection with pegylated interferon-alpha and ribavirin can eradicate chronic HCV infection in approximately 50% of patients infected with high viremia of HCV genotype 1, and spontaneous viral clearance was observed in approximately 30% of individuals with acute infection. These findings were strongly expected to reflect variations of the host genome. Significant breakthrough by the genome-wide association study (GWAS) approach led to the discovery of genetic polymorphisms playing a major role in the evolution of infection, as well as on treatment response and adverse effects. Herein, we present current evidence with regard to the relationship between host variations and clinical outcome of hepatitis C, and focus on the potential clinical implications with respect to tailor-made therapy for chronic hepatitis C.

  5. Tailored nanoporous gold for ultrahigh fluorescence enhancement.

    Science.gov (United States)

    Lang, X Y; Guan, P F; Fujita, T; Chen, M W

    2011-03-07

    We report molecular fluorescence enhancement of free-standing nanoporous gold in which the nanoporosity can be arbitrarily tailored by the combination of dealloying and electroless gold plating. The nanoporous gold fabricated by this facile method possesses unique porous structures with large gold ligaments and very small pores, and exhibits significant improvements in surface enhanced fluorescence as well as structure rigidity. It demonstrates that the confluence effect of improved quantum yield and excitation of fluorophores is responsible for the large fluorescence enhancement due to the near-field enhancement of nanoporous gold, which arises from the strong electromagnetic coupling between neighboring ligaments and the weakening of plasmon damping of the large ligaments because of the small pore size and large ligament size, respectively.

  6. Structure, crystallization and dielectric resonances in 2-13 GHz of waste-derived glass-ceramic

    Science.gov (United States)

    Yao, Rui; Liao, SongYi; Chen, XiaoYu; Wang, GuangRong; Zheng, Feng

    2016-12-01

    Structure, kinetics of crystallization, and dielectric resonances of waste-derived glass-ceramic prepared via quench-heating route were studied as a function of dosage of iron ore tailing (IOT) within 20-40 wt% using X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and vector network analyzer (VNA) measurements. The glass-ceramic mainly consisted of ferrite crystals embedded in borosilicate glass matrix. Crystallization kinetics and morphologies of ferrite crystals as well as coordination transformation of boron between [BO4] and [BO3] in glass network were adjustable by changing the amount of IOT. Dielectric resonances in 6-13 GHz were found to be dominated by oscillations of Ca2+ cations in glass network with [SiO4] units on their neighboring sites. Ni2+ ions made a small contribution to those resonances. Diopside formed when IOT exceeded 35 wt%, which led to weakening of the resonances.

  7. The effects of glass doping, temperature and time on the morphology, composition, and iron redox of spinel crystals

    Energy Technology Data Exchange (ETDEWEB)

    Matyas, Josef [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Amonette, James E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kukkadapu, Ravi K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Schreiber, Daniel K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kruger, Albert A. [Office of River Protection, Richland, WA (United States)

    2014-10-31

    Precipitation of large crystals/agglomerates of spinel and their accumulation in the pour spout riser of a Joule-heated ceramic melter during idling can plug the melter and prevent pouring of molten glass into canisters. Thus, there is a need to understand the effects of spinel-forming components, temperature, and time on the growth of crystals in connection with an accumulation rate. In our study, crystals of spinel [Fe, Ni, Mn, Zn, Sn][Fe, Cr]₂O₄ were precipitated from simulated high-level waste borosilicate glasses containing different concentrations of Ni, Fe, and Cr by heat treating at 850 and 900°C for different times. These crystals were extracted from the glasses and analyzed with scanning electron microscopy and image analysis for size and shape, with inductively coupled plasma-atomic emission spectroscopy and atom probe tomography for concentration of spinel-forming components, and with wet colorimetry and Mössbauer spectroscopy for Fe²⁺/Fetotal ratio. High concentrations of Ni, Fe, and Cr in glasses resulted in the precipitation of crystals larger than 100 µm in just two days. Crystals were a solid solution of NiFe₂O₄, NiCr₂O₄, and -Fe₂O₃ (identified only in the high-Ni-Fe glass) and also contained small concentrations of less than 1 at% of Li, Mg, Mn, and Al.

  8. Defense Waste Processing Facility (DWPF) Viscosity Model: Revisions for Processing High TiO2 Containing Glasses

    Energy Technology Data Exchange (ETDEWEB)

    Jantzen, C. M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Edwards, T. B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-08-30

    Radioactive high level waste (HLW) at the Savannah River Site (SRS) has successfully been vitrified into borosilicate glass in the Defense Waste Processing Facility (DWPF) since 1996. Vitrification requires stringent product/process (P/P) constraints since the glass cannot be reworked once it is poured into ten foot tall by two foot diameter canisters. A unique “feed forward” statistical process control (SPC) was developed for this control rather than statistical quality control (SQC). In SPC, the feed composition to the DWPF melter is controlled prior to vitrification. In SQC, the glass product would be sampled after it is vitrified. Individual glass property-composition models form the basis for the “feed forward” SPC. The models transform constraints on the melt and glass properties into constraints on the feed composition going to the melter in order to guarantee, at the 95% confidence level, that the feed will be processable and that the durability of the resulting waste form will be acceptable to a geologic repository.

  9. Liquid Glass: A Facile Soft Replication Method for Structuring Glass.

    Science.gov (United States)

    Kotz, Frederik; Plewa, Klaus; Bauer, Werner; Schneider, Norbert; Keller, Nico; Nargang, Tobias; Helmer, Dorothea; Sachsenheimer, Kai; Schäfer, Michael; Worgull, Matthias; Greiner, Christian; Richter, Christiane; Rapp, Bastian E

    2016-06-01

    Liquid glass is a photocurable amorphous silica nanocomposite that can be structured using soft replication molds and turned into glass via thermal debinding and sintering. Simple polymer bonding techniques allow the fabrication of complex microsystems in glass like microfluidic chips. Liquid glass is a step toward prototyping of glass microstructures at low cost without requiring cleanroom facilities or hazardous chemicals.

  10. Radiation effects in glasses

    Energy Technology Data Exchange (ETDEWEB)

    Ehrt, D.; Vogel, W. (Otto-Schott-Inst., Chemische Fakultaet, Friedrich-Schiller-Univ., Jena (Germany))

    1992-03-01

    Glass was produced by man about 4000 years ago. The scientific exploration of glass is very young and closely connected with Jena. Fraunhofer, Goethe, Dobereiner, Abbe, Zeiss and Schott are famous names on this field. Both crystals and glasses are solids. However, there are fundamental differences in their properties and behavior. Glass is a thermodynamically unstable state and has a defect structure compared to the crystal. Glass and its properties are subject to a variety of changes under the influence of high energy radiation. In general, effects extend from the reduction of specific ions to the collapse of the entire network. Ultraviolet and X-ray radiation effects on UV-transmitting glasses will be discussed. (orig.).

  11. Homogeneity of Inorganic Glasses

    DEFF Research Database (Denmark)

    Jensen, Martin; Zhang, L.; Keding, Ralf;

    2011-01-01

    Homogeneity of glasses is a key factor determining their physical and chemical properties and overall quality. However, quantification of the homogeneity of a variety of glasses is still a challenge for glass scientists and technologists. Here, we show a simple approach by which the homogeneity...... of different glass products can be quantified and ranked. This approach is based on determination of both the optical intensity and dimension of the striations in glasses. These two characteristic values areobtained using the image processing method established recently. The logarithmic ratio between...... the dimension and the intensity is used to quantify and rank the homogeneity of glass products. Compared with the refractive index method, the image processing method has a wider detection range and a lower statistical uncertainty....

  12. Glass melter off-gas system pluggages: Cause, significance, and remediation

    Energy Technology Data Exchange (ETDEWEB)

    Jantzen, C.M.

    1991-03-01

    Liquid high-level nuclear waste will be immobilized at the Savannah River Site (SRS) by vitrification in borosilicate glass. The glass will be produced in the Defense Waste Processing Facility (DWPF) where the glass will be poured into stainless steel canisters for eventual disposal in a geologic repository. Experimental glass melters used to develop the vitrification process for immobilization of the waste have experienced problems with pluggage of the off-gas line with solid deposits. Off-gas deposits from the DWPF 1/2 Scale Glass Melter (SGM) and the 1/10th scale Integrated DWPF Melter System (IDMS) were determined to be mixtures of alkali rich chlorides, sulfates, borates, and fluorides with entrained Fe{sub 2}O{sub 3}, spinel, and frit particles. The distribution and location of the alkali deposits throughout the off-gas system indicate that the deposits form by vapor-phase transport and condensation. Condensation of the alkali-rich phases cement the entrained particulates causing off-gas system pluggages. The identification of vapor phase transport as the operational mechanism causing off-gas system pluggage indicates that deposition can be effectively eliminated by increasing the off-gas velocity. Scale glass melter operating experience indicates that a velocity of >50 fps is necessary in order to transport the volatile species to the quencher to prevent having condensation occur in the off-gas line. Hotter off-gas line temperatures would retain the alkali compounds as vapors so that they would remain volatile until they reach the quencher. However, hotter off-gas temperatures can only be achieved by using less air/steam flow at the off-gas entrance, e.g. at the off-gas film cooler (OGFC). This would result in lower off-gas velocities. Maintaining a high velocity is, therefore, considered to be a more important criterion for controlling off-gas pluggage than temperature control. 40 refs., 16 figs., 5 tabs.

  13. Effects of tailoring health messages on physical activity

    NARCIS (Netherlands)

    T. Smeets (Tamara); J. Brug (Hans); H. de Vries (Hein)

    2008-01-01

    textabstractComputer-tailored printed education can be a promising way of promoting physical activity. The present study tested whether computer-tailored feedback on physical activity is effective and whether there are differences between respondents with low and high motivation to change. Responden

  14. Tailored cognitive-behavioral therapy for fibromyalgia: two case studies.

    NARCIS (Netherlands)

    Koulil, S. van; Lankveld, W. van; Kraaimaat, F.W.; Helmond, T. van; Vedder, A.; Hoorn, H. van; Cats, H.; Riel, P.L.C.M. van; Evers, A.W.

    2008-01-01

    OBJECTIVE: To illustrate a multidisciplinary group treatment for patients with fibromyalgia (FM) tailored to the patient's cognitive-behavioral pattern. METHOD: In a case-study design the tailored treatment approaches of two FM patients were described. One patient characterized by avoidance behavior

  15. Free-solution electrophoretic separations of DNA-drag-tag conjugates on glass microchips with no polymer network and no loss of resolution at increased electric field strength.

    Science.gov (United States)

    Albrecht, Jennifer Coyne; Kerby, Matthew B; Niedringhaus, Thomas P; Lin, Jennifer S; Wang, Xiaoxiao; Barron, Annelise E

    2011-05-01

    Here, we demonstrate the potential for high-resolution electrophoretic separations of ssDNA-protein conjugates in borosilicate glass microfluidic chips, with no sieving media and excellent repeatability. Using polynucleotides of two different lengths conjugated to moderately cationic protein polymer drag-tags, we measured separation efficiency as a function of applied electric field. In excellent agreement with prior theoretical predictions of Slater et al., resolution is found to remain constant as applied field is increased up to 700 V/cm, the highest field we were able to apply. This remarkable result illustrates the fundamentally different physical limitations of free-solution conjugate electrophoresis (FSCE)-based DNA separations relative to matrix-based DNA electrophoresis. ssDNA separations in "gels" have always shown rapidly declining resolution as the field strength is increased; this is especially true for ssDNA > 400 bases in length. FSCE's ability to decouple DNA peak resolution from applied electric field suggests the future possibility of ultra-rapid FSCE sequencing on chips. We investigated sources of peak broadening for FSCE separations on borosilicate glass microchips, using six different protein polymer drag-tags. For drag-tags with four or more positive charges, electrostatic and adsorptive interactions with poly(N-hydroxyethylacrylamide)-coated microchannel walls led to appreciable band-broadening, while much sharper peaks were seen for bioconjugates with nearly charge-neutral protein drag-tags.

  16. Diamond turning of glass

    Energy Technology Data Exchange (ETDEWEB)

    Blackley, W.S.; Scattergood, R.O.

    1988-12-01

    A new research initiative will be undertaken to investigate the critical cutting depth concepts for single point diamond turning of brittle, amorphous materials. Inorganic glasses and a brittle, thermoset polymer (organic glass) are the principal candidate materials. Interrupted cutting tests similar to those done in earlier research are Ge and Si crystals will be made to obtain critical depth values as a function of machining parameters. The results will provide systematic data with which to assess machining performance on glasses and amorphous materials

  17. Raman Spectra of Glasses

    Science.gov (United States)

    1986-11-30

    17), Raman spectra, plus a , . theoretical treatment of the data, f complex fluorozirconate 14 I anions in ZBLAN glasses and melts (16), and...based ZBLAN glasses ) 17. ICORS (International Conference on Raman Spectroscopy) Proceedings, London, England. Conferencf 5-9 Sep 88. (Molten silica...RESEARCH FINAL REPORT DTIC CONTRACT N00014-81-K-0501 &JELECTE 1 MAY 81 -- 30 NOV 86 EJJAN041989 V "RAMAN SPECTRA OF GLASSES " 0 During the five years of the

  18. Letter report on PCT/Monolith glass ceramic corrosion tests

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, Charles L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-09-24

    The Savannah River National Laboratory (SRNL) is collaborating with personnel from Pacific Northwest National Laboratory (PNNL) to study advanced waste form glass ceramics for immobilization of waste from Used Nuclear Fuel (UNF) separations processes. The glass ceramic waste forms take advantage of both crystalline and glassy phases where ‘troublesome’ elements (e.g., low solubility in glass or very long-lived) partition to highly durable ceramic phases with the remainder of elements residing in the glassy phase. The ceramic phases are tailored to create certain minerals or unique crystalline structures that can host the radionuclides by binding them in their specific crystalline network while not adversely impacting the residual glass network (Crum et al., 2011). Glass ceramics have been demonstrated using a scaled melter test performed in a pilot scale (1/4 scale) cold crucible induction melter (CCIM) (Crum et al., 2014; Maio et al., 2015). This report summarizes recent results from both Phase I and Phase II bench scale tests involving crucible fabrication and corrosion testing of glass ceramics using the Product Consistency Test (PCT). Preliminary results from both Phase I and Phase II bench scale tests involving statistically designed matrices have previously been reported (Crawford, 2013; Crawford, 2014).

  19. Metal Halide Optical Glasses.

    Science.gov (United States)

    1988-01-01

    while some of the multi- component "modified" glasses (e.g., ZBLAN ) could easily be cast into pieces several mm thick. 23 The difference between the...energy. 7-1 0 Typical plots pf 24 of log Iqi versus ]/Tf for ZB-I, ZBL, ZBLA, ZBLAN and ZBLALi glasses are presented in Fig. 3. These plots are linear... ZBLAN glasses are more resistant to devitrification than the corresponding ZBLLi or ZBLN glasses , although this does not appear to be manifested in

  20. High Performance Optical Coatings Utilizing Tailored Refractive Index Nanoporous Thin Films

    Science.gov (United States)

    Poxson, David J.

    fabricated by oblique-angle deposition techniques have been restricted to rigid and planar substrates such as silicon and glass. This limitation greatly constrains the applicability, tailorability, functionality and even the economic viability of such nanoporous films. As another avenue into extending the applicability of such films, here we demonstrate a novel nanoporous film / polymer substrate composite system fabricated by utilizing oblique-angle electron-beam methodology. This unique composite system exhibits several favorable characteristics, namely i) fine-tuned control over film nano-porosity and thickness, ii) excellent adhesion between the nanoporous film and polymer substrate, iii) and ability to withstand significant and repeated bending as well as three dimensional molding, all the while closely retaining the composite system's designed nanostructure and optical properties. These newly available characteristics show promise to greatly extend the range of applications and functionalities of such nanoporous films.

  1. Does tailoring really make a difference? : the development and evaluation of tailored interventions aimed at benzodiazepine cessation

    NARCIS (Netherlands)

    Wolde, Geeske Brecht ten

    2008-01-01

    Because of the problems associated with chronic benzodiazepine use, there is impetus to prevent and reduce chronic benzodiazepine use. The overall aim was to develop a 'tailor-made' intervention in order to reduce chronic use. Before developing tailored patient education, it is first of all importan

  2. Microstructural analysis of interfaces between lanthanum contained glass and two different electrolytes for SOFC applications

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, G.; Pandey, O.P.; Singh, K. [School of Physics and Materials Science, Thapar University, Punjab (India)

    2012-10-15

    The diffusion couples of lanthanum based strontium borosilicate glass with two different (high and low temperature) electrolytes have been heat-treated at 850 and 800 C, respectively, for 5, 100, and 750 h to understand the mechanism of interface formation and growth. These prepared diffusion couples have been characterized using various techniques like X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray dot mapping, and electron probe microanalysis (EPMA). XRD revealed no detrimental phase formation. Other thermodynamic parameters like frequency factor, crystallization constants, free volume, and bulk thermal expansion coefficients have been calculated to understand the behavior of glass under the influence of temperature. These theoretical parameters will enable to understand the interfacial growth observed in heat-treated couple for its end application in SOFC. The observed results indicate that lanthanum containing glass exhibit stable and smooth interface with yttria-stabilized zirconia (high-temperature electrolyte) as compared to doped bismuth vanadate (low temperature electrolyte). (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  3. A laser-engraved glass duplicating the structure, mechanics and performance of natural nacre.

    Science.gov (United States)

    Valashani, Seyed Mohammad Mirkhalaf; Barthelat, Francois

    2015-03-30

    Highly mineralized biological materials such as nacre (mother of pearl), tooth enamel or conch shell boast unique and attractive combinations of stiffness, strength and toughness. The structures of these biological materials and their associated mechanisms are now inspiring new types of advanced structural materials. However, despite significant efforts, no bottom up fabrication method could so far match biological materials in terms of microstructural organization and mechanical performance. Here we present a new 'top down' strategy to tackling this fabrication problem, which consists in carving weak interfaces within a brittle material using a laser engraving technique. We demonstrate the method by fabricating and testing borosilicate glasses containing nacre-like microstructures infiltrated with polyurethane. When deformed, these materials properly duplicate the mechanisms of natural nacre: combination of controlled sliding of the tablets, accompanied with geometric hardening, strain hardening and strain rate hardening. The nacre-like glass is composed of 93 volume % (vol%) glass, yet 700 times tougher and breaks at strains as high as 20%.

  4. Contribution of Monte-Carlo modeling for understanding long-term behavior of nuclear glasses

    Energy Technology Data Exchange (ETDEWEB)

    Minet, Y.; Ledieu, A.; Devreux, F.; Barboux, P.; Frugier, P.; Gin, S

    2004-07-01

    Monte-Carlo methods have been developed at CEA and Ecole Polytechnique to improve our understanding of the basic mechanisms that control glass dissolution kinetics. The models, based on dissolution and recondensation rates of the atoms, can reproduce the observed alteration rates and the evolutions of the alteration layers on simplified borosilicate glasses (based on SiO{sub 2}-B{sub 2}O{sub 3}-Na{sub 2}O) over a large range of compositions and alteration conditions. The basic models are presented, as well as their current evolutions to describe more complex glasses (introduction of Al, Zr, Ca oxides) and to take into account phenomena which may be predominant in the long run (such as diffusion in the alteration layer or secondary phase precipitation). The predictions are compared with the observations performed by techniques giving structural or textural information on the alteration layer (e.g. NMR, Small Angle X-ray Scattering). The paper concludes with proposals for further evolutions of Monte-Carlo models towards integration into a predictive modeling framework. (authors)

  5. Computer tailored nutrition education: Mediterranean diet.

    Science.gov (United States)

    del Balzo, V; Vitiello, V; Dernini, S; Zicari, S; Giusti, A M; Donini, L M; Pinto, A; Cannella, C

    2012-01-01

    Goal of this work is to promote via on-line applications the knowledge of the Italian Weekly Pyramid, which is based on the concept of WI (Well Being Index) as a unit for a correct lifestyle. On the website www.piramideitaliana.it the user can verify his/her weekly lifestyle by participating in a "game" based on the introduction, for seven consecutive days, of food and beverages consumption and time assigned to physical activity. At the end of the seven days it is possible to access the page with an evaluation of dietary habits together with the possible suggestions for a correct lifestyle. On the basis of the data collected through this web game, a statistical analysis has been developed to evaluate the food habits and the level of physical activity. In the period between September 2005-January 2010 16,546 participants have completed the game. The data collected compare actual WI consumption for each food group with the one suggested by the Pyramid. The sample eating pattern appears almost varied; all the food groups were consumed daily, albeit in much lower quantities with regard to the suggested portions. It is pointed out that some differences in the nutritional habits are related to differences in age groups and in the school degree of the sample analyzed. This work highlights the importance of web-based tailored interventions on population food habits: many people can be reached to promote the knowledge of the guidelines leading to a healthy lifestyle.

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

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, J.H.

    1996-05-01

    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 4 cm{sup 3} have been made and methods for continuous melting laser glass are under development.

  7. Dielectric and impedance spectroscopic studies of (Sr1–Pb)TiO2 glass ceramics with addition of Nb2O5

    Indian Academy of Sciences (India)

    C R Gautam; Devendra Kumar; Om Parkash

    2011-12-01

    Glasses were made by melt-quench method in the system [(Sr1–Pb)O.TiO2]–[2SiO2.B2O3]–5[K2O–BaO] (0.0 ≤ ≤ 0.4) with addition of 1 mol% Nb2O5. Perovskite strontium lead titanate in solid solution phase has been crystallized in borosilicate glassy matrix with suitable choice of composition and heat treatment schedule. Addition of 1 mol% of Nb2O5 enhances the crystallization of lead strontium titanate phase in the glassy matrix. Scanning electron microscopy (SEM) is performed to study the surface morphology of the crystallites and crystalline interface to the glass. Dielectric properties of these glass ceramics were studied by measuring capacitance and dissipation factor as a function of temperature at a few selected frequencies. Nb2O5 doped strontium lead titanate glass ceramic shows a high value of dielectric constant. It is of the order of 10,000 while the dielectric constant of undoped glass ceramic sample is of the order of 500. Complex impedance and modulus spectroscopic techniques were used to find out the contributions of polarization of crystallites and glass crystal interfaces to the resulting dielectric behaviour.

  8. Lanthanoides in Glass and Glass Ceramics

    Science.gov (United States)

    Meinhardt, Jürgen; Kilo, Martin; Somorowsky, Ferdinand; Hopp, Werner

    2017-03-01

    Many types of glass contain lanthanoides; among them, special glass for optical applications is the one with the highest content of lanthanoides. The precise determination of the lanthanoides' concentration is performed by inductively coupled plasma-optical emission spectrometry (ICP-OES). However, up to now, there are no established standard processes guaranteeing a uniform approach to the lanthanoide analysis. The knowledge of the lanthanoides' concentrations is necessary on the microscale in some cases, especially if a suitable separation and recycling procedure is to be applied. Here, the analysis is performed by energy-dispersive X-ray (EDX) or wavelength-dispersive X-ray (WDX) analytics in the scanning electron microscope.

  9. Understanding the effects of alpha self-irradiation on the glass structure by coupling spectroscopic studies and atomistic modeling; Comprehension structurale des effets d'auto-irradiation alpha dans les verre: couplage entre etudes spectroscopiques et modelisation atomistique

    Energy Technology Data Exchange (ETDEWEB)

    Bureau, G.

    2008-12-15

    Our objective was to assess irradiation effects on nuclear containment glass in order to guarantee glass performance when subjected to high alpha decay doses. Experimental studies and molecular dynamics modeling provided a better understanding of the impact of cumulative alpha decay on the structural behavior of complex nuclear glass formulations and of simplified glass models. A mechanism typical of sodium borosilicate glass was identified in response to nuclear interactions or ballistic collisions. The glass local order is slightly modified by the conversion of a fraction of the boron atoms from coordination number IV to III, releasing charge-compensating alkali ions that become available as network modifiers, and resulting in a slight increase in the number of non bridging oxygen atoms. The medium-range order shifts toward increasing disorder in the glass as indicated by broadening of the angular, radial, and size distributions. A model of accumulated quasi-thermal quenching is proposed to account for these changes, based on the two steps describing the reaction of the glass to the alpha decay recoil nucleus: a cascade generates a ballistic phase that completely destabilizes the glass structure with no short and medium-range order, resulting in the loss of the initial structure; glass reconstruction is controlled only by the 'quenching rate' in the displacement cascade, i.e. by its thermal history and the corresponding relaxation options. From this standpoint the final glass structure is the consequence of the ballistic changes and the regenerative capacity of the glass structure, resulting in a higher fictive-temperature glass corresponding to the structural changes identified in this study. (author)

  10. lead glass brick

    CERN Multimedia

    As well as accelerators to boost particles up to high energy, physicists need detectors to see what happens when those particles collide. This lead glass block is part of a CERN detector called OPAL. OPAL uses some 12 000 blocks of glass like this to measure particle energies.

  11. Getting Started with Glass

    Science.gov (United States)

    White, Heather

    2007-01-01

    The metamorphosis of glass when heated is a magical process to students, yet teachers are often reluctant to try it in class. The biggest challenge in working with glass in the classroom is to simplify procedures just enough to ensure student success while maintaining strict safety practices so no students are injured. Project concepts and safety…

  12. Glass Sword of Damocles

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    A string of accidents draws attention to the safety of the gleaming glass-walled skyscrapers, now common in China’s major cities On July 8, as 19-year-old Zhu Yiyi was walking past a 23-story building in Hangzhou, east China’s Zhejiang Province, shards of glass falling

  13. Glasses for photonic applications

    NARCIS (Netherlands)

    Richardson, K.; Krol, D.M.; Hirao, K.

    2010-01-01

    Recent advances in the application of glassy materials in planar and fiber-based photonic structures have led to novel devices and components that go beyond the original thinking of the use of glass in the 1960s, when glass fibers were developed for low-loss, optical communication applications. Expl

  14. Electric glass capturing markets

    Energy Technology Data Exchange (ETDEWEB)

    Wikman, K.; Wikstroem, T.

    1996-11-01

    Electric glass has found its place on the construction market. In public buildings, electrically heatable windows are becoming the leading option for large glass walls. Studies on detached houses, both new and renovated, show that floor heating combined with electrically heatable windowpanes is the best choice with respect to resident`s comfort. (orig.)

  15. Tailoring electronic structure of polyazomethines thin films

    Directory of Open Access Journals (Sweden)

    J. Weszka

    2010-09-01

    Full Text Available Purpose: The aim of this work is to show how electronic properties of polyazomethine thin films deposited by chemical vapor deposition method (CVD can be tailored by manipulating technological parameters of pristine films preparation as well as modifying them while the as-prepared films put into iodine atmosphere.Design/methodology/approach: The recent achievements in the field of designing and preparation methods to be used while preparing polymer photovoltaic solar cells or optoelectronic devices.Findings: The method used allow for pure pristine polymer thin films to be prtepared without any unintentional doping taking place during prepoaration methods. This is a method based on polycondensation process, where polymer chain developing is running directly due to chemical reaction between molecules of bifunctional monomers. The method applied to prepare thin films of polyazomethines takes advantage of monomer transporting by mreans of neutral transport agent as pure argon is.Research limitations/implications: The main disadvantage of alternately conjugated polymers seems to be quite low mobility of charge carrier that is expected to be a consequence of their backbone being built up of sp2 hybridized carbon and nitrogen atoms. Varying technological conditions towards increasing reagents mass transport to the substrate is expected to give such polyazomethine thin films organization that phenylene rin stacking can result in special π electron systems rather than linear ones as it is the case.Originality/value: Our results supply with original possibilities which can be useful in ooking for good polymer materials for optoelectronic and photovoltaic applications. These results have been gained on polyazomethine thin films but their being isoelectronic counterpart to widely used poly p-phenylene vinylene may be very convenient to develop high efficiency polymer solar cells

  16. Defense HLW Glass Degradation Model

    Energy Technology Data Exchange (ETDEWEB)

    D. Strachan

    2004-10-20

    The purpose of this report is to document the development of a model for calculating the release rate for radionuclides and other key elements from high-level radioactive waste (HLW) glasses under exposure conditions relevant to the performance of the repository. Several glass compositions are planned for the repository, some of which have yet to be identified (i.e., glasses from Hanford and Idaho National Engineering and Environmental Laboratory). The mechanism for glass dissolution is the same for these glasses and the glasses yet to be developed for the disposal of DOE wastes. All of these glasses will be of a quality consistent with the glasses used to develop this report.

  17. Comparing tailored and untailored text messages for smoking cessation

    DEFF Research Database (Denmark)

    Skov-Ettrup, Lise; Ringgaard, L W; Dalum, Peter

    2014-01-01

    the entire study population, as well as those opting for text messages (n = 1619). In intention-to-treat analysis with multiple imputation of missing data, the odds ratio for 30-day point abstinence was 1.28 (95% CI 0.91-2.08) for the tailored compared with untailored messages. When restricting the analysis...... to those who had chosen to receive text messages, the corresponding odds ratio was 1.45 (95% CI 1.01-2.08). The higher long-term quit rates in the group receiving the tailored text messages compared with untailored text messages in the restricted analysis indicated that tailoring and higher frequency...

  18. Low-temperature bonding process for the fabrication of hybrid glass-membrane organ-on-a-chip devices

    Science.gov (United States)

    Pocock, Kyall J.; Gao, Xiaofang; Wang, Chenxi; Priest, Craig; Prestidge, Clive A.; Mawatari, Kazuma; Kitamori, Takehiko; Thierry, Benjamin

    2016-10-01

    The integration of microfluidics with living biological systems has paved the way to the exciting concept of "organs-on-a-chip," which aims at the development of advanced in vitro models that replicate the key features of human organs. Glass-based devices have long been utilized in the field of microfluidics but the integration of alternative functional elements within multilayered glass microdevices, such as polymeric membranes, remains a challenge. To this end, we have extended a previously reported approach for the low-temperature bonding of glass devices that enables the integration of a functional polycarbonate porous membrane. The process was initially developed and optimized on specialty low-temperature bonding equipment (μTAS2001, Bondtech, Japan) and subsequently adapted to more widely accessible hot embosser units (EVG520HE Hot Embosser, EVG, Austria). The key aspect of this method is the use of low temperatures compatible with polymeric membranes. Compared to borosilicate glass bonding (650°C) and quartz/fused silica bonding (1050°C) processes, this method maintains the integrity and functionality of the membrane (Tg 150°C for polycarbonate). Leak tests performed showed no damage or loss of integrity of the membrane for up to 150 h, indicating sufficient bond strength for long-term cell culture. A feasibility study confirmed the growth of dense and functional monolayers of Caco-2 cells within 5 days.

  19. IgG1 adsorption to siliconized glass vials-influence of pH, ionic strength, and nonionic surfactants.

    Science.gov (United States)

    Höger, Kerstin; Mathes, Johannes; Frieß, Wolfgang

    2015-01-01

    In this study, the adsorption of an IgG1 antibody to siliconized vials was investigated with focus on the formulation parameters pH, ionic strength, and nonionic surfactants. Electrophoretic mobility measurements were performed to investigate the charge characteristics of protein and siliconized glass particles at different pH values. Calculation of the electrokinetic charge density allowed further insight into the energetic conditions in the protein-sorbent interface. Maximum adsorption of IgG1 was found at acidic pH values and could be correlated with energetically favorable minimal ion incorporation into the interface. The importance of electrostatic interactions for IgG1 adsorption at acidic pH values was also confirmed by the efficient adsorption reduction at decreased solution ionic strength. A second adsorption maximum around the pI of the protein was assigned to hydrophobic interactions with the siliconized surface. Addition of the nonionic surfactants poloxamer 188 or polysorbate 80 resulted in almost complete suppression of adsorption at pH 7.2, and a strong but less efficient effect at pH 4 on siliconized glass vials. This adsorption suppression was much less pronounced on borosilicate glass vials. From these results, it can be concluded that electrostatic interactions contribute substantially to IgG1 adsorption to siliconized glass vials especially at acidic formulation pH.

  20. Performance of laser bonded glass/polyimide microjoints in cerebrospinal fluid.

    Science.gov (United States)

    Mian, A; Newaz, G; Georgiev, D G; Rahman, N; Vendra, L; Auner, G; Witte, R; Herfurth, H

    2007-03-01

    In this paper, laser bonded microjoints between glass and polyimide is considered to examine their potential applicability in encapsulating neural implants. To facilitate bonding between polyimide and glass, a thin titanium film with a thickness of 2 microm was deposited on borosilicate glass plates by a physical vapor deposition (PVD) process. Titanium coated glass was then joined with polyimide by using a cw fiber laser emitting at a wavelength of 1.1 microm (1.0 W) to prepare several tensile samples. Some of the samples were exposed to artificial cerebrospinal fluid (aCSF) at 37 degrees C for two weeks to assess long-term integrity of the joints. Both the as-received and aCSF soaked samples were subjected to uniaxial tensile loads for bond strengths measurements. The bond strengths for the as-received and aCSF soaked samples were measured to be 7.31 and 5.33 N/mm, respectively. Although the long-term exposure of the microjoints to aCSF has resulted in 26% reduction of bond strength, the samples still retain considerably high strength as compared with the titanium-polyimide samples. The failed glass/polyimide samples were also analyzed using optical microscopy, and failure mechanisms are discussed. In addition, a two dimensional finite element analysis (FEA) was conducted to understand the stress distribution within the substrate materials while the samples are in tension. The FEA results match reasonably well with the experimental load-displacement curves for as-received samples. Detailed discussion on various stress contours is presented in the paper, and the failure mechanisms observed from the experiment are shown in good agreement with the FEA predicted ones.

  1. HLW glass dissolution in the presence of magnesium carbonate: Diffusion cell experiment and coupled modeling of diffusion and geochemical interactions

    Energy Technology Data Exchange (ETDEWEB)

    Debure, Mathieu, E-mail: mathieu.debure@gmail.com [CEA Marcoule, DTCD/SECM/LCLT, BP 17171, 30207 Bagnols-sur-Cèze Cedex (France); Geosciences Dept., Mines-ParisTech, 35 Rue St-Honoré, 77305 Fontainebleau (France); De Windt, Laurent [Geosciences Dept., Mines-ParisTech, 35 Rue St-Honoré, 77305 Fontainebleau (France); Frugier, Pierre; Gin, Stéphane [CEA Marcoule, DTCD/SECM/LCLT, BP 17171, 30207 Bagnols-sur-Cèze Cedex (France)

    2013-11-15

    Highlights: •Diffusion of dissolved elements in pore water impacts nuclear glass alteration. •The glass/magnesium carbonate system has been studied in diffusion cells. •Glass alteration is enhanced by Mg–silicates precipitation but slowed down by diffusion. •Coupling between dissolution, diffusion and secondary phases controls the glass alteration. •The ability of reactive transport models to simulate the whole processes is investigated. -- Abstract: The influence of diffusion of reactive species in aqueous solutions on the alteration rate of borosilicate glass of nuclear interest in the presence of magnesium carbonate (hydromagnesite: 4MgCO{sub 3}·Mg(OH){sub 2}·4H{sub 2}O) is investigated together with the ability of coupled chemistry/transport models to simulate the processes involved. Diffusion cells in which the solids are separated by an inert stainless steel sintered filter were used to establish parameters for direct comparison with batch experiments in which solids are intimately mixed. The chemistry of the solution and solid phases was monitored over time by various analytical techniques including ICP-AES, XRD, and SEM. The primary mechanism controlling the geochemical evolution of the system remains the consumption of silicon from the glass by precipitation of magnesium silicates. The solution chemistry and the dissolution and precipitation of solid phases are correctly described by 2D modeling with the GRAAL model implemented in the HYTEC reactive transport code. The spatial symmetry of the boron concentrations in both compartments of the cells results from dissolution coupled with simple diffusion, whereas the spatial asymmetry of the silicon and magnesium concentrations is due to strong coupling between dissolution, diffusion, and precipitation of secondary phases. A sensitivity analysis on the modeling of glass alteration shows that the choice of these phases and their thermodynamic constants have only a moderate impact whereas the

  2. Thermal Conductivity of Foam Glass

    DEFF Research Database (Denmark)

    Petersen, Rasmus Rosenlund; König, Jakob; Yue, Yuanzheng

    with different gas compositions. The foam glasses were characterised concerning densities, open/closed porosity and crystallinity. We find out, through analytical calculations and experiments, how the thermal conductivity of foam glass depends on density, glass composition and gas composition. Certain glass......Due to the increased focus on energy savings and waste recycling foam glass materials have gained increased attention. The production process of foam glass is a potential low-cost recycle option for challenging waste, e.g. CRT glass and industrial waste (fly ash and slags). Foam glass is used...... as thermal insulating material in building and chemical industry. The large volume of gas (porosity 90 – 95%) is the main reason of the low thermal conductivity of the foam glass. If gases with lower thermal conductivity compared to air are entrapped in the glass melt, the derived foam glass will contain...

  3. Structurally-Tailorable, Nonlinear, Snap-Through Spring

    Science.gov (United States)

    Starnes, James H., Jr.; Farley, Gary L.; Mantay, Wayne R.

    1989-01-01

    Abrupt change in load/deflection response controllable and predictable. Structurally-tailorable, nonlinear, snap-through spring (STNSTS) exhibits controllable and predictable abrupt change in load/deflection response and based upon known phenomenon of snap-through structural response. Composed of pin-connected two-bar linkage which depicts combined tension/compression springs. As load applied to STNSTS, stiffness is function of internal spring and bending stiffness of pin-connected bars. As load increases, bars deform laterally until they collapse and snap through. Has application in passively-tailored rotor-blade flap, pitch, and lag response, to improve aerodynamic performance and stability characteristics of rotors; in aerodynamically- and aeroelastically-tailored wing spars and ribs, to produce tailored deformation state for improved effectiveness in maneuvering, aerodynamic performance, and stability characteristics; and in energy absorbers for automobile bumpers and aircraft land

  4. Recent Results for the Ferritics Isotopic Tailoring (FIST) Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Gelles, David S.; Hamilton, Margaret L.; Oliver, Brian M.; Greenwood, Lawrence R.; Ohnuki, Somei; Shiba, K.; Kohno, Y.; Kohyama, Akira; Robertson, J. P.

    2001-10-01

    The results of shear punch testing, microstructural examination, and hydrogen and helium analyses performed on irradiated isotopically tailored alloys are reported for specimens irradiated in the HFIR JP20 experiment.

  5. Past, present, and future of computer-tailored nutrition education

    NARCIS (Netherlands)

    J. Brug (Hans); A. Oenema (Anke); M.K. Campbell (Marci)

    2003-01-01

    textabstractComputer-tailored nutrition education is an innovative and promising tool to motivate people to make healthy dietary changes. It provides respondents with individualized feedback about their dietary behaviors, motivations, attitudes, norms, and skills and mimics the pro

  6. Tailoring Magnetic Properties in Bulk Nanostructured Solids

    Science.gov (United States)

    Morales, Jason Rolando

    Important magnetic properties and behaviors such as coercivity, remanence, susceptibility, energy product, and exchange coupling can be tailored by controlling the grain size, composition, and density of bulk magnetic materials. At nanometric length scales the grain size plays an increasingly important role since magnetic domain behavior and grain boundary concentration determine bulk magnetic behavior. This has spurred a significant amount of work devoted to developing magnetic materials with nanometric features (thickness, grain/crystallite size, inclusions or shells) in 0D (powder), 1D (wires), and 2D (thin films) materials. Large 3D nanocrystalline materials are more suitable for many applications such as permanent magnets, magneto-optical Faraday isolators etc. Yet there are relatively few successful demonstrations of 3D magnetic materials with nanoscale influenced properties available in the literature. Making dense 3D bulk materials with magnetic nanocrystalline microstructures is a challenge because many traditional densification techniques (HIP, pressureless sintering, etc.) move the microstructure out of the "nano" regime during densification. This dissertation shows that the Current Activated Pressure Assisted Densification (CAPAD) method, also known as spark plasma sintering, can be used to create dense, bulk, magnetic, nanocrystalline solids with varied compositions suited to fit many applications. The results of my research will first show important implications for the use of CAPAD for the production of exchange-coupled nanocomposite magnets. Decreases in grain size were shown to have a significant role in increasing the magnitude of exchange bias. Second, preferentially ordered bulk magnetic materials were produced with highly anisotropic material properties. The ordered microstructure resulted in changing magnetic property magnitudes (ex. change in coercivity by almost 10x) depending on the relative orientation (0° vs. 90°) of an externally

  7. Tailored Materials for High Efficiency CIDI Engines

    Energy Technology Data Exchange (ETDEWEB)

    Grant, G.J.; Jana, S.

    2012-03-30

    The overall goal of the project, Tailored Materials for High Efficiency Compression Ignition Direct Injection (CIDI) Engines, is to enable the implementation of new combustion strategies, such as homogeneous charge compression ignition (HCCI), that have the potential to significantly increase the energy efficiency of current diesel engines and decrease fuel consumption and environmental emissions. These strategies, however, are increasing the demands on conventional engine materials, either from increases in peak cylinder pressure (PCP) or from increases in the temperature of operation. The specific objective of this project is to investigate the application of a new material processing technology, friction stir processing (FSP), to improve the thermal and mechanical properties of engine components. The concept is to modify the surfaces of conventional, low-cost engine materials. The project focused primarily on FSP in aluminum materials that are compositional analogs to the typical piston and head alloys seen in small- to mid-sized CIDI engines. Investigations have been primarily of two types over the duration of this project: (1) FSP of a cast hypoeutectic Al-Si-Mg (A356/357) alloy with no introduction of any new components, and (2) FSP of Al-Cu-Ni alloys (Alloy 339) by physically stirring-in various quantities of carbon nanotubes/nanofibers or carbon fibers. Experimental work to date on aluminum systems has shown significant increases in fatigue lifetime and stress-level performance in aluminum-silicon alloys using friction processing alone, but work to demonstrate the addition of carbon nanotubes and fibers into aluminum substrates has shown mixed results due primarily to the difficulty in achieving porosity-free, homogeneous distributions of the particulate. A limited effort to understand the effects of FSP on steel materials was also undertaken during the course of this project. Processed regions were created in high-strength, low-alloyed steels up to 0.5 in

  8. Semiconductor quantum optics with tailored photonic nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Laucht, Arne

    2011-06-15

    single photon emission into the waveguide. The results obtained during the course of this thesis contribute significantly to the understanding of coupling phenomena between excitons in self-assembled quantum dots and optical modes of tailored photonic nanostructures realized on the basis of two-dimensional photonic crystals. While we highlight the potential for advanced applications in the direction of quantum optics and quantum computation, we also identify some of the challenges which will need to be overcome on the way. (orig.)

  9. Second harmonic generation and two-photon luminescence upconversion in glasses doped with ZnSe nanocrystalline quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Thantu, Napoleon [Idaho National Engineering and Environmental Laboratory, 2525 Fremont Avenue, Idaho Falls, ID 83415 (United States)]. E-mail: Napoleon.Thantu@ngc.com

    2005-01-01

    We report two-photon excited emission in borosilicate glasses doped with ZnSe nanocrystalline quantum dots. The emission, predominantly near the two-photon energy and detected in the direction of the excitation beam, is in the visible, and the fundamental excitation is the near-infrared output of a tunable femtosecond laser. Depending on the two-photon energy, time- and frequency-resolved measurements at room temperature reveal that the emission largely consists of second harmonic generation (SHG) and two-photon luminescence upconversion, and a much smaller luminescence from redshifted, low-lying trap states and other trap levels residing near the semiconductor band edge. We discuss the SHG origin in terms of bulk-like and surface contributions from the nanocrystals and the two-photon resonant enhancement near the excitonic absorption.

  10. Tailoring of the luminescent ions local environment in optical fibers, and applications

    CERN Document Server

    Dussardier, Bernard; Peterka, P

    2012-01-01

    The chapter is situated in the fields of fiber materials sciences and technologies (particularly dealing with the fiber glass compositions and luminescent ion doping, and transparent glass ceramic optical fibers), and applications such as fiber lasers and amplifiers. We propose to present a review of research activities on rare-earth (RE) and transition metals (TM) doped silica-based optical fibers, aiming at understanding theier spectral properties, and particularly some of their optical transitions that will allow interesting and alternative applications. Silica, as opposed to alternative, low temperature materials, is chosen for practical and economical reasons. Selected RE and TM ions are studied both as probes of their local environment and for their application potentials. In this chapter, we will focus on erbium (Er) ions for the potential spectral 'tailoring' of its gain curve at 1.55 $\\mu$m, thulium (Tm) as local environment probe along both near infrared transitions around 0.8 and 1.47 $\\mu$m, and c...

  11. Glass Stronger than Steel

    Science.gov (United States)

    Yarris, Lynn

    2011-03-28

    A new type of damage-tolerant metallic glass, demonstrating a strength and toughness beyond that of steel or any other known material, has been developed and tested by a collaboration of researchers from Berkeley Lab and Caltech.

  12. Shattering the Glass Ceiling

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    @@ "Shattering the Glass Ceiling: the Myths, Opportunities and Chal lenges of Women in Corporate China" was the theme of CEIBS'first Women in Management Forum held on December l 1 on the school's main campus in Shanghai.

  13. Mechanically reinforced glass beams

    DEFF Research Database (Denmark)

    Nielsen, Jens Henrik; Olesen, John Forbes

    2007-01-01

    to breakage without any warning or ductility, which can be catastrophic if no precautions are taken. One aspect of this issue is treated here by looking at the possibility of mechanically reinforcing glass beams in order to obtain ductile failure for such a structural component. A mechanically reinforced...... the mechanical behavior of the beam is explained. Finally, some design criterions for reinforced glass beams are discussed....

  14. Baseline LAW Glass Formulation Testing

    Energy Technology Data Exchange (ETDEWEB)

    Kruger, Albert A. [USDOE Office of River Protection, Richland, WA (United States); Mooers, Cavin [The Catholic University of America, Washington, DC (United States). Vitreous State Lab.; Bazemore, Gina [The Catholic University of America, Washington, DC (United States). Vitreous State Lab; Pegg, Ian L. [The Catholic University of America, Washington, DC (United States). Vitreous State Lab; Hight, Kenneth [The Catholic University of America, Washington, DC (United States). Vitreous State Lab; Lai, Shan Tao [The Catholic University of America, Washington, DC (United States). Vitreous State Lab; Buechele, Andrew [The Catholic University of America, Washington, DC (United States). Vitreous State Lab; Rielley, Elizabeth [The Catholic University of America, Washington, DC (United States). Vitreous State Lab; Gan, Hao [The Catholic University of America, Washington, DC (United States). Vitreous State Lab; Muller, Isabelle S. [The Catholic University of America, Washington, DC (United States). Vitreous State Lab; Cecil, Richard [The Catholic University of America, Washington, DC (United States). Vitreous State Lab

    2013-06-13

    The major objective of the baseline glass formulation work was to develop and select glass formulations that are compliant with contractual and processing requirements for each of the LAW waste streams. Other objectives of the work included preparation and characterization of glasses with respect to the properties of interest, optimization of sulfate loading in the glasses, evaluation of ability to achieve waste loading limits, testing to demonstrate compatibility of glass melts with melter materials of construction, development of glass formulations to support ILAW qualification activities, and identification of glass formulation issues with respect to contract specifications and processing requirements.

  15. Preparation, heat treatment and photoluminescence properties of V-doped ZnO-SiO{sub 2}-B{sub 2}O{sub 3} glasses

    Energy Technology Data Exchange (ETDEWEB)

    Hamnabard, Zohreh, E-mail: zhamnabard@nrcam.org [Materials Research School, Ceramic Group, P.O. Box 14395-836, Alborz (Iran, Islamic Republic of); Khalkhali, Zahra, E-mail: khalkhali_z@yahoo.com [Department of Material Science, Ceramic Division, Iran University of Science and Technology, Tehran (Iran, Islamic Republic of); Qazvini, Shamsi Sadat Alavi, E-mail: IRUH81@yahoo.com [Faculty of Materials Engineering, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Baghshahi, Saeid, E-mail: s.baghshahi@ikiu.ac.ir [Faculty of Engineering and Technology, I.K.I. University, Qazvin (Iran, Islamic Republic of); Maghsoudipour, Amir, E-mail: a_maghsoudi@merc.ac.ir [Ceramic Division, Materials and Energy Research Center, Alborz (Iran, Islamic Republic of)

    2012-05-15

    Four glasses in ZnO-SiO{sub 2}-B{sub 2}O{sub 3} ternary system were prepared by the melt quenching method with the objective of optimizing sub-nanosecond emission over the UV region of zinc borosilicate glasses used in superfast scintillators. The effect of vanadium addition and heat treatment on phase formation, microstructure and photoluminescence properties of the glasses was characterized by means of DTA, XRD, SEM and fluorescence spectrophotometer. Vanadium contributed to the near-band-edge emission in two ways, by introducing donor levels in the energy band of ZnO particles and by facilitating the precipitation of ZnO and willemite crystals. Furthermore, nucleation of willemite and zinc oxide phases, which are both the origins of the intense emission bands in the UV region, was facilitated with increasing either the time or temperature of heat treatments. Photoluminescence spectra showed the elimination of the visible emission band which is favorable in scintillating glasses. - Highlights: Black-Right-Pointing-Pointer Phase analysis, thermal behavior, microstructure and photoluminescence properties. Black-Right-Pointing-Pointer Crystallization driving forces and mechanisms. Black-Right-Pointing-Pointer Optical basicity of ZnO-SiO{sub 2}-B{sub 2}O{sub 3} glasses.

  16. Controlling the reaction between boron-containing sealing glass and a lanthanum-containing cathode by adding Nb2O5

    Science.gov (United States)

    Zhao, Dandan; Fang, Lihua; Tang, Dian; Zhang, Teng

    2016-09-01

    In solid oxide fuel cell (SOFC) stacks, the volatile boron species present in the sealing glass often react with the lanthanum-containing cathode, degrading the activity of the cathode (this phenomenon is known as boron poisoning). In this work, we report that this detrimental reaction can be effectively reduced by doping bismuth-containing borosilicate sealing glass-ceramic with a niobium dopant. The addition of Nb2O5 not only condenses the [SiO4] structural units in the glass network, but also promotes the conversion of [BO3] to [BO4]. Moreover, the Nb2O5 dopant enhances the formation of boron-containing phases (Ca3B2O6 and CaB2Si2O8), which significantly reduces the volatility of boron compounds in the sealing glass, suppressing the formation of LaBO3 in the reaction couple between the glass and the cathode. The reported results provide a new approach to solve the problem of boron poisoning.

  17. A glass capillary based microfluidic electromembrane extraction of basic degradation products of nitrogen mustard and VX from water.

    Science.gov (United States)

    Tak, Vijay; Kabra, Ankur; Pardasani, Deepak; Goud, D Raghavender; Jain, Rajeev; Dubey, D K

    2015-12-24

    In this work, a glass capillary based microfluidic electromembrane extraction (μ-EME) was demonstrated for the first time. The device was made by connecting an auxillary borosilicate glass tubing (O.D. 3mm, I.D. 2mm) perpendicular to main borosilicate glass capillary just below one end of the capillary (O.D. 8mm, I.D. 1.2mm). It generated the distorted T-shaped device with inlet '1' and inlet '2' for the introduction of sample and acceptor solutions, respectively. At one end of this device (inlet '2'), a microsyringe containing acceptor solution along with hollow fiber (O.D. 1000μm) was introduced. This configuration creates the micro-channel between inner wall of glass capillary and outer surface of hollow fiber. Sample solution was pumped into the system through another end of glass capillary (inlet '1'), with a micro-syringe pump. The sample was in direct contact with the supported liquid membrane (SLM), consisted of 20% (w/w) di-(2-ethylhexyl)phosphate in 2-nitrophenyl octyl ether immobilized in the pores of the hollow fiber. In the lumen of the hollow fiber, the acceptor phase was present. The driving force for extraction was direct current (DC) electrical potential sustained over the SLM. Highly polar (logP=-2.5 to 1.4) basic degradation products of nitrogen mustard and VX were selected as model analytes. The influence of chemical composition of SLM, extraction time, voltage and pH of donor and acceptor phase were investigated. The model analytes were extracted from 10μL of pure water with recoveries ranging from 15.7 to 99.7% just after 3min of operation time. Under optimized conditions, good limits of detection (2-50ngmL(-1)), linearity (from 5-1000 to 100-1000ngmL(-1)), and repeatability (RSDs below 11.9%, n=3) were achieved. Applicability of the proposed μ-EME was proved by recovering triethanolamine (31.3%) from 10μL of five times diluted original water sample provided by the Organization for the Prohibition of Chemical Weapons during 28th official

  18. Glass microsphere lubrication

    Science.gov (United States)

    Geiger, Michelle; Goode, Henry; Ohanlon, Sean; Pieloch, Stuart; Sorrells, Cindy; Willette, Chris

    1991-01-01

    The harsh lunar environment eliminated the consideration of most lubricants used on earth. Considering that the majority of the surface of the moon consists of sand, the elements that make up this mixture were analyzed. According to previous space missions, a large portion of the moon's surface is made up of fine grained crystalline rock, about 0.02 to 0.05 mm in size. These fine grained particles can be divided into four groups: lunar rock fragments, glasses, agglutinates (rock particles, crystals, or glasses), and fragments of meteorite material (rare). Analysis of the soil obtained from the missions has given chemical compositions of its materials. It is about 53 to 63 percent oxygen, 16 to 22 percent silicon, 10 to 16 percent sulfur, 5 to 9 percent aluminum, and has lesser amounts of magnesium, carbon, and sodium. To be self-supporting, the lubricant must utilize one or more of the above elements. Considering that the element must be easy to extract and readily manipulated, silicon or glass was the most logical choice. Being a ceramic, glass has a high strength and excellent resistance to temperature. The glass would also not contaminate the environment as it comes directly from it. If sand entered a bearing lubricated with grease, the lubricant would eventually fail and the shaft would bind, causing damage to the system. In a bearing lubricated with a solid glass lubricant, sand would be ground up and have little effect on the system. The next issue was what shape to form the glass in. Solid glass spheres was the only logical choice. The strength of the glass and its endurance would be optimal in this form. To behave as an effective lubricant, the diameter of the spheres would have to be very small, on the order of hundreds of microns or less. This would allow smaller clearances between the bearing and the shaft, and less material would be needed. The production of glass microspheres was divided into two parts, production and sorting. Production includes the

  19. Optimized Synthesis of Foam Glass from Recycled CRT Panel Glass

    DEFF Research Database (Denmark)

    Petersen, Rasmus Rosenlund; König, Jakob; Yue, Yuanzheng

    Most of the panel glass from cathode ray tubes (CRTs) is landfilled today. Instead of landfilling, the panel glass can be turned into new environment-friendly foam glass. Low density foam glass is an effective heat insulating material and can be produced just by using recycle glass and foaming...... additives. In this work we recycle the CRT panel glass to synthesize the foam glass as a crucial component of building and insulating materials. The synthesis conditions such as foaming temperature, duration, glass particle size, type and concentrations of foaming agents, and so on are optimized...... by performing systematic experiments. In particular, the concentration of foaming agents is an important parameter that influences the size of bubbles and the distribution of bubbles throughout the sample. The foam glasses are characterised regarding density and open/closed porosity. Differential scanning...

  20. Glass–water interaction: Effect of high-valence cations on glass structure and chemical durability

    Energy Technology Data Exchange (ETDEWEB)

    Hopf, J.; Kerisit, Sebastien N.; Angeli, F.; Charpentier, Thibault M.; Icenhower, Jonathan P.; McGrail, Bernard P.; Windisch, Charles F.; Burton, Sarah D.; Pierce, Eric M.

    2016-05-15

    Borosilicate glass is a durable solid, but it dissolves when in contact with aqueous fluids. The dissolution mechanism, which involves a variety of sequential reactions that occur at the solid-fluid interface, has important implications for the corrosion resistance of industrial and nuclear waste glasses. In this study, spectroscopic measurements, dissolution experiments, and Monte Carlo simulations were performed to investigate the effect of high–valence cations (HVC) on the mechanisms of glass dissolution under dilute and near-saturated conditions. Raman and NMR spectroscopy were used to determine the structural changes that occur in glass, specifically network formers (e.g., Al, Si, and B), with the addition of the HVC element hafnium in the Na2O–Al2O3–B2O3–HfO2–SiO2 system (e.g., Na/[Al+B] = 1.0 and HfO2/SiO2 from 0.0 to 0.42). Spectroscopic measurements revealed that increasing hafnium content decreases N4 (tetrahedral boron/total boron) and increases the amount of Si—O—Hf moieties in the glass. Results from flow–through experiments conducted under dilute and near–saturated conditions show a decrease of approximately 100× or more in the dissolution rate over the series from 0 to 20 mol% HfO2. Comparing the average steady-state rates obtained under dilute conditions to the rates obtained for near-saturated conditions reveals a divergence in the magnitude between the average steady state rates measured in these different conditions. The reason for this divergence was investigated more thoroughly using Monte Carlo simulations. Simulations indicate that the divergence in glass dissolution behavior under dilute and near-saturated conditions result from the stronger binding of Si sites that deposit on the surface from the influent when Hf is present in the glass. As a result, the residence time at the glass surface of these newly-formed Si sites is longer in the presence of Hf, which increases the density of anchor sites from which altered layers

  1. An overview of the effects of thermal processing on bioactive glasses

    Directory of Open Access Journals (Sweden)

    Bellucci D.

    2010-01-01

    Full Text Available Bioglass® 45S5 is widely used in biomedical applications due to its ability to bond to bone and even to soft tissues. The sintering ability of Bioglass® powders is a key factor from a technological point of view, since its govern the production of advanced devices, ranging from highly porous scaffolds to functionalized coatings. Unfortunately this particular glass composition is prone to crystallize at the temperature required for sintering and this may impair the bioactivity of the original glass. For these reasons, a prerequisite to tailor the fabrication of Bioglass®-derived implants is to understand the interaction between sintering, crystallization and bioactivity. In this work the structural transformations which occur during the heat treatment of Bioglass® are reviewed and a special attention is paid to the sintering and crystallization processes. Moreover the bioactivity of the final glass-ceramics is discussed and some alternative glass formulations are reported.

  2. White light emitting Ho{sup 3+}-doped CdS nanocrystal ingrained glass nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Dey, Chirantan; Karmakar, Basudeb, E-mail: basudebk@cgcri.res.in [Glass Science and Technology Section, Glass Division, CSIR-Central Glass and Ceramic Research Institute, 196, Raja S. C. Mullick Road, Kolkata 700032 (India); Goswami, Madhumita [Glass and Advanced Materials Division, Bhaba Atomic Research Centre, Trombay, Mumbai 400085 (India)

    2015-02-23

    We report the generation of white light from Ho{sup 3+} ion doped CdS nanocrystal ingrained borosilicate glass nanocomposites prepared by the conventional melt-quench method. Near visible 405 nm diode laser excited white light emission is produced by tuning the blue emission from the Ho{sup 3+} ions, green band edge, and orange-red surface-state emissions of the nanocrystalline CdS, which are further controlled by the size of the nanocrystals. The absorption and emission spectra evidenced the excitation of Ho{sup 3+} ions by absorption of photons emitted by the CdS nanocrystals. The high color rendering index (CRI = 84–89) and befitting chromaticity coordinates (x = 0.308–0.309, y = 0.326–0.338) of white light emission, near visible harmless excitation wavelength (405 nm), and high absorbance values at excitation wavelength point out that these glass nanocomposites may serve as a prominent candidate for resin free high power white light emitting diodes.

  3. Transport properties of microwave sintered pure and glass added MgCuZn ferrites

    Energy Technology Data Exchange (ETDEWEB)

    Madhuri, W., E-mail: madhuriw12@gmail.com [School of Advanced Sciences, VIT University, Vellore 632 014 (India); Penchal Reddy, M.; Kim, Il Gon [Department of Physics, Changwon National University, Changwon 641 773 (Korea, Republic of); Rama Manohar Reddy, N. [Department of Materials Science and Nanotechnology, Yogi Vemana University, Kadapa 516 227 (India); Siva Kumar, K.V. [Ceramic Composites Materials Laboratory, Sri Krishnadevaraya University, Anantapur 515 055 (India); Murthy, V.R.K. [Microwave Laboratory, IIT Madras, Chennai 600 036 (India)

    2013-07-01

    Highlights: • MgCuZn ferrite was successfully prepared by novel microwave sintering (MS) method. • The sintering temperature was notably reduced from 1150 °C to 950 °C for MS. • Temperature dependence of DC conductivity and AC conductivity are studied. • 1 wt% PBS glass added MS MgCuZn ferrite samples are suitable for core materials in multilayer chip inductors (MLCI). -- Abstract: A series of pure stoichiometric and 1 wt% lead borosilicate (PBS) glass added MgCuZn ferrite with the general formula Mg{sub 0.5}Cu{sub x}Zn{sub 0.5−x}Fe{sub 2}O{sub 4} with x = 0.05, 0.1, 0.15, 0.2, 0.25 and 0.3 were synthesized by microwave sintering technique. Single phase spinel structure is exhibited by the XRD patterns of these ferrites. DC and AC conductivity were investigated as a function of composition, temperature and frequency. DC conductivities were also estimated using the impedance spectroscopy analysis of Cole–Cole plots. The DC conductivities thus obtained are in good agreement with the experimental results. All the investigated samples exhibited two regions of conductivity one in the low temperature and the second in the high temperature region. It is observed that PBS glass added samples have lower conductivities than pure samples. Due to their lower conductivities and sintering temperatures the 1 wt% PBS glass added samples are suitable for multilayer chip inductor (MLCI) and high definition TV deflection yoke material application.

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

    Energy Technology Data Exchange (ETDEWEB)

    Huang, W. [School of Materials Science and Engineering, Tongji Univ., Shanghai, SH (China); Day, D.E.; Ray, C.S.; Kim, C.W.; Reis, S.T.D. [Univ. of Missouri-Rolla (United States). Graduate Center for Materials Research

    2004-10-01

    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{sub 2}O{sub 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{sup -9} g/(cm{sup 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 <0.1 g/(m{sup 2} . d) after 7 d at 200 C by the vapor hydration test (VHT). The solubility limit for Cr{sub 2}O{sub 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{sub 2}O{sub 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{sub 2}O{sub 3} which is at least three times larger than that for borosilicate glasses. (orig.)

  5. Shape-Tailored Features and their Application to Texture Segmentation

    KAUST Repository

    Khan, Naeemullah

    2014-04-01

    Texture Segmentation is one of the most challenging areas of computer vision. One reason for this difficulty is the huge variety and variability of textures occurring in real world, making it very difficult to quantitatively study textures. One of the key tools used for texture segmentation is local invariant descriptors. Texture consists of textons, the basic building block of textures, that may vary by small nuisances like illumination variation, deformations, and noise. Local invariant descriptors are robust to these nuisances making them beneficial for texture segmentation. However, grouping dense descriptors directly for segmentation presents a problem: existing descriptors aggregate data from neighborhoods that may contain different textured regions, making descriptors from these neighborhoods difficult to group, leading to significant errors in segmentation. This work addresses this issue by proposing dense local descriptors, called Shape-Tailored Features, which are tailored to an arbitrarily shaped region, aggregating data only within the region of interest. Since the segmentation, i.e., the regions, are not known a-priori, we propose a joint problem for Shape-Tailored Features and the regions. We present a framework based on variational methods. Extensive experiments on a new large texture dataset, which we introduce, show that the joint approach with Shape-Tailored Features leads to better segmentations over the non-joint non Shape-Tailored approach, and the method out-performs existing state-of-the-art.

  6. Effects of tailoring health messages on physical activity.

    Science.gov (United States)

    Smeets, Tamara; Brug, J; de Vries, H

    2008-06-01

    Computer-tailored printed education can be a promising way of promoting physical activity. The present study tested whether computer-tailored feedback on physical activity is effective and whether there are differences between respondents with low and high motivation to change. Respondents (n = 487) were randomly assigned to a tailored intervention group or a no information control group. Physical activity and determinants were measured at baseline and after 3 months. At post-test, the motivated respondents in the control group were more likely not to meet the recommendation for physical activity than to meet it, and motivated respondents in the experimental group were more likely to engage in transport-related activities and showed more improvement over time for the total activity score than respondents in the control group (beta = 0.24, P = 0.02). Both groups improved their behaviour over time. No group differences in physical activity were found for the unmotivated respondents. The results showed that the effects of the tailored feedback were restricted to respondents who had a positive motivation to change at baseline. Possible explanations could be that unmotivated respondents were unwilling to read and process the information because they felt 'no need to change'. Alternatively, one tailored feedback letter may not have been sufficient for this unmotivated group.

  7. Sol-Gel Glasses

    Science.gov (United States)

    Mukherjee, S. P.

    1985-01-01

    Multicomponent homogeneous, ultrapure noncrystalline gels/gel derived glasses are promising batch materials for the containerless glass melting experiments in microgravity. Hence, ultrapure, homogeneous gel precursors could be used to: (1) investigate the effect of the container induced nucleation on the glass forming ability of marginally glass forming compositions; and (2) investigate the influence of gravity on the phase separation and coarsening behavior of gel derived glasses in the liquid-liquid immiscibility zone of the nonsilicate systems having a high density phase. The structure and crystallization behavior of gels in the SiO2-GeO2 as a function of gel chemistry and thermal treatment were investigated. As are the chemical principles involved in the distribution of a second network former in silica gel matrix being investigated. The procedures for synthesizing noncrystalline gels/gel-monoliths in the SiO2-GeO2, GeO2-PbO systems were developed. Preliminary investigations on the levitation and thermal treatment of germania silicate gel-monoliths in the Pressure Facility Acoustic Levitator were done.

  8. Characterization of the Italian glasses and their interaction with clay Task 3 Characterization of radioactive waste forms a series of final reports (1985-89) No 23

    Energy Technology Data Exchange (ETDEWEB)

    Cantale, C.; Castelli, S.; Donato, A.; Traverso, D.M. [ENEA, Casaccia (IT)

    1991-12-31

    The objective of this research work was the selection of a borosilicate glass composition suitable for the solidification of the HLW stream coming from the treatment of all the high-level wastes stored in Italy (MTR, Candu and Elk River) and the characterization of this glass with reference to the geological disposal. This research work was part of an Italian research project named `Ulisse project`, whose goal was the development and the demonstration of an integrated treatment of all the HLW stored in Italy, after their mixing (resulting waste: MCE waste). The main concept is to carry out a pre-treatment of the wastes, in order to concentrate the HLW fraction and to simplify the vitrification process, separating the most part of the inert salts. The research work concerning the separation process and pilot plant demonstration of the pre-treatment process were carried out in the framework of the CEC R and D programme (Contract No Fl1W-0011-lS). The laboratory studies concerning the vitrification of the resulting HLW streams and the vitrification demonstration in the Italian full-scale, inactive IVET plant complete the `Ulisse project`. Some glass compositions were prepared and preliminarily characterized. The glass named BAZ was finally selected. A complete characterization of this glass was carried out in order to evaluate its mechanical, physical and physico-chemical properties. The chemical durability was evaluated by the MCC-1 static leach test at 90{sup 0}C, using three different leachants and two surface-area to leachant-volume ratios. The same characterization programme was applied to the BAZ glass produced in the IVET plant during the plant vitrification demonstration programme. A comparison between the two glasses and a critical evaluation of their performances with respect to other nuclear waste glasses` durability was performed. 25 refs.; 46 figs.; 20 tabs.

  9. The descent into glass formation in polymer fluids.

    Science.gov (United States)

    Freed, Karl F

    2011-03-15

    -Fulcher equation, whereas pressure and concentration analogs of the Vogel-Fulcher expression follow naturally from the theory with no additional assumptions. The computed dependence of T(g) and fragility on the length of the side group in poly(α-olefins) agrees quite well with observed trends, demonstrating that the theory can be utilized, for instance, to guide the tailoring of T(g) and the fragility of glass-forming polymer fluids in the fabrication of new materials. Our calculations also elucidate the molecular characteristics of small-molecule diluents that promote antiplasticization, a lowering of T(g) and a toughening of the material.

  10. Self-quenching of spontaneous emission in Sm 3+ doped lead-borate glass

    Science.gov (United States)

    Manoj Kumar, G.; Shivakiran Bhaktha, B. N.; Narayana Rao, D.

    2006-08-01

    The lifetimes of Sm 3+ doped in a binary glass are studied as a function of the complex refractive index of the glass. The local field effect has been taken into account and a real cavity around the emitter is assumed. The results are analyzed in the framework of the quantum electrodynamical equation to obtain a parameter that is related to the radius of cavity around Sm 3+. The knowledge of this parameter is crucial in tailoring the lifetimes and has been found to be 1.48 nm.

  11. Magneto-Optical and Magnetic Studies of Co-Rich Glass-Covered Microwires

    Directory of Open Access Journals (Sweden)

    Alexander Chizhik

    2012-01-01

    Full Text Available The magnetization reversal process in the surface and volume areas of Co-rich glass-covered microwires has been investigated. The study has been performed in the wide series of microwires with chemical composition, geometry (thickness of glass coating with the purpose of the tailoring of the giant magnetoimpedance effect. The comparative analysis of the magnetoelectric, magnetic, and magneto-optical experiments permits to optimise the giant magnetoimpedance ratio and elucidate the main properties of the magnetization reversal process in the different parts of the Co-rich microwire.

  12. Fascinating properties of bioactive templated glasses: A new generation of nanostructured bioceramics

    Science.gov (United States)

    Izquierdo-Barba, Isabel; Vallet-Regí, María

    2011-04-01

    This review article, dedicated to Prof. Osamu Terasaki, is focused on current trends in nanostructured bioceramics in the field of bone repair and regeneration. This communication overviews the main characteristics of so called "templated glasses" recently described which exhibit an outstanding bioactive behavior compared with conventional bioactive glasses. A deep study regarding the control of textural, structural and compositional properties in the nanometric scale in relation to the charming bioactivity properties described for these nanostructured materials is herein discussed. The possibility to tailor such properties offers a wide range of reactivity/bioactivity depending on the medical application requested.

  13. Bio-Glasses An Introduction

    CERN Document Server

    Jones, Julian

    2012-01-01

    This new work is dedicated to glasses and their variants which can be used as biomaterials to repair diseased and damaged tissues. Bio-glasses are superior to other biomaterials in many applications, such as healing bone by signaling stem cells to become bone cells.   Key features:  First book on biomaterials to focus on bio-glassesEdited by a leading authority on bio-glasses trained by one of its inventors, Dr Larry HenchSupported by the International Commission on Glass (ICG)Authored by members of the ICG Biomedical Glass Committee, with the goal of creating a seamless textb

  14. Glass strengthening and patterning methods

    Science.gov (United States)

    Harper, David C; Wereszczak, Andrew A; Duty, Chad E

    2015-01-27

    High intensity plasma-arc heat sources, such as a plasma-arc lamp, are used to irradiate glass, glass ceramics and/or ceramic materials to strengthen the glass. The same high intensity plasma-arc heat source may also be used to form a permanent pattern on the glass surface--the pattern being raised above the glass surface and integral with the glass (formed of the same material) by use of, for example, a screen-printed ink composition having been irradiated by the heat source.

  15. Glass formation - A contemporary view

    Science.gov (United States)

    Uhlmann, D. R.

    1983-01-01

    The process of glass formation is discussed from several perspectives. Particular attention is directed to kinetic treatments of glass formation and to the question of how fast a given liquid must be cooled in order to form a glass. Specific consideration is paid to the calculation of critical cooling rates for glass formation, to the effects of nucleating heterogeneities and transients in nucleation on the critical cooling rates, to crystallization on reheating a glass, to the experimental determination of nucleation rates and barriers to crystal nucleation, and to the characteristics of materials which are most conducive to glass formation.

  16. Tailorable Stimulated Brillouin Scattering in Nanoscale Silicon Waveguides

    CERN Document Server

    Shin, Heedeuk; Jarecki, Robert; Cox, Jonathan A; Olsson, Roy H; Starbuck, Andrew; Wang, Zheng; Rakich, Peter T

    2013-01-01

    While nanoscale modal confinement radically enhances a variety of nonlinear light-matter interactions within silicon waveguides, traveling-wave stimulated Brillouin scattering nonlinearities have never been observed in silicon nanophotonics. Through a new class of hybrid photonic-phononic waveguides, we demonstrate tailorable traveling-wave forward stimulated Brillouin scattering in nanophotonic silicon waveguides for the first time, yielding 3000 times stronger forward SBS responses than any previous waveguide system. Simulations reveal that a coherent combination of electrostrictive forces and radiation pressures are responsible for greatly enhanced photon-phonon coupling at nano-scales. Highly tailorable Brillouin nonlinearities are produced by engineering the structure of a membrane-suspended waveguide to yield Brillouin resonances from 1 to 18 GHz through high quality-factor (>1000) phonon modes. Such wideband and tailorable stimulated Brillouin scattering in silicon photonics could enable practical real...

  17. Goal Model Integration for Tailoring Product Line Development Processes

    Directory of Open Access Journals (Sweden)

    Arfan Mansoor

    2016-07-01

    Full Text Available Many companies rely on the promised benefits of product lines, targeting systems between fully custom made software and mass products. Such customized mass products account for a large number of applications automatically derived from a product line. This results in the special importance of product lines for companies with a large part of their product portfolio based on their product line. The success of product line development efforts is highly dependent on tailoring the development process. This paper presents an integrative model of influence factors to tailor product line development processes according to different project needs, organizational goals, individual goals of the developers or constraints of the environment. This model integrates goal models, SPEM models and requirements to tailor development processes.

  18. Building Tailorable Hypermedia Systems: The embedded-interpreter approach

    DEFF Research Database (Denmark)

    Grønbæk, Kaj; Malhotra, Jawahar

    1994-01-01

    This paper discusses an approach for developing dynamically tailorable hypermedia systems in an object-oriented environment. The approach is aimed at making applications developed in compiled languages like Beta and C++ tailorable at run-time. The approach is based on use of: 1) a hypermedia...... application framework (DEVISE Hyper-media), and 2) an embeddable interpreter for the framework language. A specific hypermedia system is instantiated from the framework with the interpreter embedded in the executable. The specific hypermedia system has a number of “open points” which can be filled via......-type. The paper describes the framework and illustrates how the interpreter is integrated. It describes steps involved in tailoring a specific hypermedia system with a new drawing media-type, where graphical objects can be endpoints for links. Since the hypermedia framework uses a persistent object...

  19. Tailoring the energy distribution and loss of 2D plasmons

    CERN Document Server

    Lin, Xiao; López, Josué J; Kaminer, Ido; Chen, Hongsheng; Soljačić, Marin

    2016-01-01

    The ability to tailor the energy distribution of plasmons at the nanoscale has many applications in nanophotonics, such as designing plasmon lasers, spasers, and quantum emitters. To this end, we analytically study the energy distribution and the proper field quantization of 2D plasmons with specific examples for graphene plasmons. We find that the portion of the plasmon energy contained inside graphene (energy confinement factor) can exceed 50%, despite graphene being infinitely thin. In fact, this very high energy confinement can make it challenging to tailor the energy distribution of graphene plasmons just by modifying the surrounding dielectric environment or the geometry, such as changing the separation distance between two coupled graphene layers. However, by adopting concepts of parity-time symmetry breaking, we show that tuning the loss in one of the two coupled graphene layers can simultaneously tailor the energy confinement factor and propagation characteristics, causing the phenomenon of loss-indu...

  20. Tailoring the energy distribution and loss of 2D plasmons

    Science.gov (United States)

    Lin, Xiao; Rivera, Nicholas; López, Josué J.; Kaminer, Ido; Chen, Hongsheng; Soljačić, Marin

    2016-10-01

    The ability to tailor the energy distribution of plasmons at the nanoscale has many applications in nanophotonics, such as designing plasmon lasers, spasers, and quantum emitters. To this end, we analytically study the energy distribution and the proper field quantization of 2D plasmons with specific examples for graphene plasmons. We find that the portion of the plasmon energy contained inside graphene (energy confinement factor) can exceed 50%, despite graphene being infinitely thin. In fact, this very high energy confinement can make it challenging to tailor the energy distribution of graphene plasmons just by modifying the surrounding dielectric environment or the geometry, such as changing the separation distance between two coupled graphene layers. However, by adopting concepts of parity-time symmetry breaking, we show that tuning the loss in one of the two coupled graphene layers can simultaneously tailor the energy confinement factor and propagation characteristics, causing the phenomenon of loss-induced plasmonic transparency.

  1. Thermodynamical modeling of nuclear glasses: coexistence of amorphous phases; Modelisation thermodynamique des verres nucleaires: coexistence entre phases amorphes

    Energy Technology Data Exchange (ETDEWEB)

    Adjanor, G

    2007-11-15

    Investigating the stability of borosilicate glasses used in the nuclear industry with respect to phase separation requires to estimate the Gibbs free energies of the various phases appearing in the material. In simulation, using current computational resources, a direct state-sampling of a glassy system with respect to its ensemble statistics is not ergodic and the estimated ensemble averages are not reliable. Our approach consists in generating, at a given cooling rate, a series of quenches, or paths connecting states of the liquid to states of the glass, and then in taking into account the probability to generate the paths leading to the different glassy states in ensembles averages. In this way, we introduce a path ensemble formalism and calculate a Landau free energy associated to a glassy meta-basin. This method was validated by accurately mapping the free energy landscape of a 38-atom glassy cluster. We then applied this approach to the calculation of the Gibbs free energies of binary amorphous Lennard-Jones alloys, and checked the correlation between the observed tendencies to order or to phase separate and the computed Gibbs free energies. We finally computed the driving force to phase separation in a simplified three-oxide nuclear glass modeled by a Born-Mayer-Huggins potential that includes a three-body term, and we compared the estimated quantities to the available experimental data. (author)

  2. Ultra-thin porous glass membranes--an innovative material for the immobilization of active species for optical chemosensors.

    Science.gov (United States)

    Müller, R; Anders, N; Titus, J; Enke, D

    2013-03-30

    In addition to polymers, porous glasses can be used for the immobilization of indicators, chromoionophores or enzymes. Advantages of these materials include, among others, the photochemical and thermal stability. Porous glass membranes (CPG) based on phase-separated alkali borosilicate glasses with thicknesses of 250-300 μm and dimensions of approximately 9-13 mm² were used in this work. The average pore diameter was found to be between 12 and 112 nm. Initially, the membrane permeability for water was determined. Furthermore, the absorption spectra for the water-soaked membranes were recorded optically. CPG membranes which are pH-sensitive were prepared based on the covalent immobilization of thymol blue and a derivative of styryl acridine. In each case, the absorption spectra of the immobilized indicators are shown. The t90-times vary between 4 and 20 min and were determined for the thermodynamic equilibrium. The influence of the ionic strength on the characteristic curve is discussed and detailed results are given. After the storage time of about 900 days a pH-sensitivity for a CPG membrane styryl acridine derivative sample was still detectable.

  3. Effect of particle size of starting materials on the structure and properties of biogenic hydroxyapatite/glass composites

    Directory of Open Access Journals (Sweden)

    Oleksandr Parkhomey

    2016-03-01

    Full Text Available The work is devoted to investigation of porous glass-ceramic composite materials on the basis of biogenic hydroxyapatite and sodium borosilicate glass prepared from starting powders with different particle sizes (<50 µm and <160 µm. Starting hydroxyapatite/glass weight ratio was 1.0/0.46 and sintering temperature was ∼800 °C. Microstructural characterization of the surface and fracture of the samples revealed a decrease in sizes of grains and pores with decreasing the particle size of the precursor powder. However, porosity of the composites practically did not depend on the particle size and was equal to 32.5–33.0%. The same tendency was observed for the compression strength (66–67 MPa. However, investigation of structural-mechanical properties using an indentation method, where dominant load is applied to the surface layers of sample, showed up the effect of the particle size of the starting powder on the mechanical properties of the composites: the smaller particle size, the higher mechanical properties.

  4. Heavy Metal Fluoride Glasses.

    Science.gov (United States)

    1987-04-01

    i 2N E ihhhhh1112h MEmhhhhEEEohhhhE I.’....momo 111111111’-20 LA ’Ll2. AFWL-TR-86-37 AFWL-TR- 86-37 oT C ,l C ’-’ N HEAVY METAL FLUORIDE GLASSES 0nI...Secwrit CkasmfcationJ HEAVY METAL FLUORIDE GLASSES 12. PERSONAL AUTHOR(S) Reisfield, Renata; and Eyal, Mrek 13. TYPE OF REPORT 113b. TIME COVERED 114...glasses containing about 50 mole% of ZrF4 [which can be replaced by HfF 4 or TIF 4 (Refs. 1-3) or heavy metal fluorides based on PbF2 and on 3d-group

  5. Perspectives on spin glasses

    CERN Document Server

    Contucci, Pierluigi

    2013-01-01

    Presenting and developing the theory of spin glasses as a prototype for complex systems, this book is a rigorous and up-to-date introduction to their properties. The book combines a mathematical description with a physical insight of spin glass models. Topics covered include the physical origins of those models and their treatment with replica theory; mathematical properties like correlation inequalities and their use in the thermodynamic limit theory; main exact solutions of the mean field models and their probabilistic structures; and the theory of the structural properties of the spin glass phase such as stochastic stability and the overlap identities. Finally, a detailed account is given of the recent numerical simulation results and properties, including overlap equivalence, ultrametricity and decay of correlations. The book is ideal for mathematical physicists and probabilists working in disordered systems.

  6. Aeroelastic Tailoring of Transport Wings Including Transonic Flutter Constraints

    Science.gov (United States)

    Stanford, Bret K.; Wieseman, Carol D.; Jutte, Christine V.

    2015-01-01

    Several minimum-mass optimization problems are solved to evaluate the effectiveness of a variety of novel tailoring schemes for subsonic transport wings. Aeroelastic stress and panel buckling constraints are imposed across several trimmed static maneuver loads, in addition to a transonic flutter margin constraint, captured with aerodynamic influence coefficient-based tools. Tailoring with metallic thickness variations, functionally graded materials, balanced or unbalanced composite laminates, curvilinear tow steering, and distributed trailing edge control effectors are all found to provide reductions in structural wing mass with varying degrees of success. The question as to whether this wing mass reduction will offset the increased manufacturing cost is left unresolved for each case.

  7. Methotrexate in juvenile idiopathic arthritis: towards tailor-made treatment.

    Science.gov (United States)

    Ćalasan, Maja Bulatović; Wulffraat, Nico M

    2014-07-01

    Methotrexate (MTX) is the key treatment in juvenile idiopathic arthritis (JIA). Nevertheless, MTX is not always sufficiently efficacious and can lead to adverse effects, which compromises complete disease control. In such cases, combination therapies with biologicals are given, even at MTX start, before knowing the patients' MTX response. Ideally, clinicians should be able to practice precision medicine by knowing before or early after MTX start, which patients will benefit from MTX only and which patients will not, thus requiring addition of biologicals. To make such tailor-made treatment decisions, clinicians require tools to optimize MTX treatment. In this review, we focus on tools for tailor-made MTX treatment in JIA.

  8. Doping influence by some transition elements on the irradiation effects in nuclear waste glasses; Influence du dopage par certains elements de transition sur les effets d'irradiation dans des verres d'interet nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    Florent, Olivier

    2006-06-15

    High-level waste glasses are submitted to auto-irradiation. Modelling it using external irradiations on simple glasses revealed defects production and non negligible structural changes. This thesis aims at determining the impact of a more complex composition on these effects, especially the influence of adding polyvalent transition metals. Silicate, soda-lime and alumino-borosilicate glasses are doped with different iron, chromium and manganese concentrations then {beta} irradiated at different doses up to 10{sup 9} Gy. Non doped glasses show an increase of their density and polymerisation coupled with a molecular oxygen and point defects production. Adding 0.16 mol% Fe decreases the amount of defects by 85 % and all irradiation effects. A Fe{sup 3+} reduction is also observed by EPR, optical absorption and indirectly by Raman spectroscopy. A higher than 0.32 mol% Fe concentration causes complete blockage of the evolution of polymerisation, density and defect production. The same results are obtained on chromium or manganese doped glasses. An original in situ optical absorption device shows the quick decrease of Fe{sup 3+} amount to a 25 % lower level during irradiation. Stopping irradiation causes a lower decrease of 65 %, suggesting a dynamic (h{sup 0}/e-) consuming equilibrium. He{sup +} and Kr{sup 3+} ions and {gamma} irradiated glasses tend to confirm these phenomena for all kind of irradiation with electronic excitations. (author)

  9. Mechanism for formation of NaBH4 proposed as low-pressure process for storing hydrogen in borosilicate glass–sodium solid system: a hydrogen storage material

    Indian Academy of Sciences (India)

    Aysel Kantürk Figen; Sabriye Pişkin

    2012-04-01

    The mechanism for the formation of sodium borohydride (NaBH4) was investigated for its ability to store hydrogen in the borosilicate glass–sodium (BSG–Na) solid system under low hydrogen pressure. BSG, which was prepared by melting borax with silica, was used as the starting material in the BSG–Na system that would be prepared to store hydrogen. It was observed that the mechanism for storing hydrogen in the BSG–Na solid system consisted of six steps and when the BSG–Na system was heated under a pressure of 4 atm, which was created through the use of hydrogen atmosphere, the storage of hydrogen occurred at nearly 480°C for approximate duration of 200 min, with the excellent yield (97%). In addition, the hydrogen storage capacity of the NaBH4 sample was measured using the Au–PS structure, which was designed as a mini-hydrogen cell. It was determined that the minimum amount of NaBH4 to generate the maximum volume of hydrogen gas was 12 mg/ml at 270 mV.

  10. Glass as matter

    DEFF Research Database (Denmark)

    Beim, Anne

    2000-01-01

    Refraiming the Moderns - Substitute Windows and Glass. In general terms, the seminar has contributed to the growing interest in the problems concerning the restoration of Modern Movement architecture. More particularly, it has of course drawn our attention to modern windows, which are increasingly...

  11. Stained-Glass Pastels

    Science.gov (United States)

    Laird, Shirley

    2009-01-01

    The author has always liked the look of stained-glass windows. Usually the designs are simplified and the shapes are easier for younger students to draw. This technique seemed to be the perfect place for her fifth-graders to try their hand at color mixing. The smaller spaces and simple shapes were just what she needed for this group. Her students…

  12. Microchips on glass

    NARCIS (Netherlands)

    Keulemans, M.

    2007-01-01

    Microchips on glass. What about a mobile phone that uses a single microchip to receive all the available frequency bands, plus extras such as television, gps, and Internet access? Or, in due time, see-though implants that will monitor your state of health, and equipment that will let you see through

  13. "Stained Glass" Landscape Windows

    Science.gov (United States)

    Vannata, Janine

    2008-01-01

    Both adults and children alike marvel at the grand vivid stained-glass windows created by American artist Louis Comfort Tiffany. Today he is commonly recognized as one of America's most influential designers and artists throughout the last nineteenth and early twentieth century. In the lesson described in this article, students created their own…

  14. Supercooled Liquids and Glasses

    OpenAIRE

    1999-01-01

    In these lectures, which were presented at "Soft and Fragile Matter, Nonequilibrium Dynamics, Metastability and Flow" University of St. Andrews, 8 July - 22 July, 1999, I give an introduction to the physics of supercooled liquids and glasses and discuss some computer simulations done to investigate these systems.

  15. Shattering women's glass ceiling

    OpenAIRE

    Camilleri Podesta, Marie Therese; Duca, Edward

    2013-01-01

    The role of women in academia has always greatly interested me. Several years ago, when I was asked to become Gender Issues Committee chairperson at the University of Malta, I readily accepted. http://www.um.edu.mt/think/shattering-womens-glass-ceiling/

  16. Stained Glass and Flu

    Centers for Disease Control (CDC) Podcasts

    2017-02-01

    Dr. Robert Webster, an Emeritus member of the Department of Infectious Diseases at St. Jude Children's Research Hospital, discusses his cover art story on stained glass and influenza.  Created: 2/1/2017 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 2/1/2017.

  17. Stained Glass and Flu

    Centers for Disease Control (CDC) Podcasts

    2016-02-01

    Dr. Robert Webster, an Emeritus member of the Department of Infectious Diseases at St. Jude Children's Research Hospital, discusses his cover art story on stained glass and influenza.  Created: 2/1/2016 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 2/1/2016.

  18. Yesterday's Trash Makes Tomorrow's "Glass"

    Science.gov (United States)

    Wayne, Dale

    2010-01-01

    In this article, the author describes a glass art project inspired by Dale Chihuly. This project uses two-liter plastic soda bottles which are cut apart and trimmed. Applying heat using a hair dryer, the plastic curls and takes an uneven blown-glass quality. The "glass" is then painted using acrylic paint. (Contains 2 resources and 1 online…

  19. Molecular Mobility in Sugar Glasses

    NARCIS (Netherlands)

    Dries, van den I.J.

    2000-01-01

    Glasses are liquids that exhibit solid state behavior as a result of their extremely high viscosity. Regarding their application to foods, glasses play a role in the preservation of foods, due to their high viscosity and the concomitant low molecular mobility. This thesis focuses on sugar glasses. S

  20. Analysis of glass fibre sizing

    DEFF Research Database (Denmark)

    Petersen, Helga Nørgaard; Kusano, Yukihiro; Brøndsted, Povl

    2014-01-01

    . Soxhlet extraction was used to extract components of the sizing from the glass fibres. The glass fibres, their extracts and coated glass plates were analysed by Thermo-Gravimetric Analysis combined with a mass spectrometer (TGA-MS), and Attenuated Total Reflectance Fourier Transform Infrared (ATR...

  1. Glass for Solid State Devices

    Science.gov (United States)

    Bailey, R. F.

    1982-01-01

    Glass film has low intrinsic compressive stress for isolating active layers of magnetic-bubble and other solid-state devices. Solid-state device structure incorporates low-stress glasses as barrier and spacer layers. Glass layers mechanically isolate substrate, conductor, and nickel/iron layers.

  2. MELT RATE ENHANCEMENT FOR HIGH ALUMINUM HLW (HIGH LEVEL WASTE) GLASS FORMULATION FINAL REPORT 08R1360-1

    Energy Technology Data Exchange (ETDEWEB)

    KRUGER AA; MATLACK KS; KOT W; PEGG IL; JOSEPH I; BARDAKCI T; GAN H; GONG W; CHAUDHURI M

    2010-01-04

    This report describes the development and testing of new glass formulations for high aluminum waste streams that achieve high waste loadings while maintaining high processing rates. The testing was based on the compositions of Hanford High Level Waste (HLW) with limiting concentrations of aluminum specified by the Office of River Protection (ORP). The testing identified glass formulations that optimize waste loading and waste processing rate while meeting all processing and product quality requirements. The work included preparation and characterization of crucible melts and small scale melt rate screening tests. The results were used to select compositions for subsequent testing in a DuraMelter 100 (DM100) system. These tests were used to determine processing rates for the selected formulations as well as to examine the effects of increased glass processing temperature, and the form of aluminum in the waste simulant. Finally, one of the formulations was selected for large-scale confirmatory testing on the HLW Pilot Melter (DM1200), which is a one third scale prototype of the Hanford Tank Waste Treatment and Immobilization Plant (WTP) HLW melter and off-gas treatment system. This work builds on previous work performed at the Vitreous State Laboratory (VSL) for Department of Energy (DOE) to increase waste loading and processing rates for high-iron HLW waste streams as well as previous tests conducted for ORP on the same high-aluminum waste composition used in the present work and other Hanford HLW compositions. The scope of this study was outlined in a Test Plan that was prepared in response to an ORP-supplied statement of work. It is currently estimated that the number of HLW canisters to be produced in the WTP is about 13,500 (equivalent to 40,500 MT glass). This estimate is based upon the inventory of the tank wastes, the anticipated performance of the sludge treatment processes, and current understanding of the capability of the borosilicate glass waste form

  3. DM100 AND DM1200 MELTER TESTING WITH HIGH WASTE LOADING GLASS FORMULATIONS FOR HANFORD HIGH-ALUMINUM HLW STREAMS

    Energy Technology Data Exchange (ETDEWEB)

    KRUGER AA; MATLACK KS; KOT WK; PEGG IL; JOSEPH I

    2009-12-30

    This Test Plan describes work to support the development and testing of high waste loading glass formulations that achieve high glass melting rates for Hanford high aluminum high level waste (HLW). In particular, the present testing is designed to evaluate the effect of using low activity waste (LAW) waste streams as a source of sodium in place ofchemical additives, sugar or cellulose as a reductant, boehmite as an aluminum source, and further enhancements to waste processing rate while meeting all processing and product quality requirements. The work will include preparation and characterization of crucible melts in support of subsequent DuraMelter 100 (DM 100) tests designed to examine the effects of enhanced glass formulations, glass processing temperature, incorporation of the LAW waste stream as a sodium source, type of organic reductant, and feed solids content on waste processing rate and product quality. Also included is a confirmatory test on the HLW Pilot Melter (DM1200) with a composition selected from those tested on the DM100. This work builds on previous work performed at the Vitreous State Laboratory (VSL) for Department of Energy's (DOE's) Office of River Protection (ORP) to increase waste loading and processing rates for high-iron HLW waste streams as well as previous tests conducted for ORP on the same waste composition. This Test Plan is prepared in response to an ORP-supplied statement of work. It is currently estimated that the number of HLW canisters to be produced in the Hanford Tank Waste Treatment and Immobilization Plant (WTP) is about 12,500. This estimate is based upon the inventory ofthe tank wastes, the anticipated performance of the sludge treatment processes, and current understanding of the capability of the borosilicate glass waste form. The WTP HLW melter design, unlike earlier DOE melter designs, incorporates an active glass bubbler system. The bubblers create active glass pool convection and thereby improve heat

  4. Tailor-made blanks for the aircraft industry

    NARCIS (Netherlands)

    Zad Poor, A.A.

    2010-01-01

    Tailor-Made Blanks (TMBs) are hybrid assemblies made of sheet metals with different materials and/or thicknesses that are joined together prior to forming. Alternatively, a monolithic sheet can be machined to create required thickness variations (machined TMBs). The possibility of having several thi

  5. Tailoring Small IT Projects in the Project Planning Phase

    Science.gov (United States)

    Mulhearn, Michael F.

    2011-01-01

    Project management (PM) and systems engineering (SE) are essential skills in information technology (IT). There is an abundance of information available detailing the comprehensive bodies of knowledge, standards, and best practices. Despite the volume of information, there is surprisingly little information about how to tailor PM and SE tasks for…

  6. Tailor-Made Peer-Therapy Groups for Children.

    Science.gov (United States)

    Clement, Paul W.

    A child's peers may influence his behavior for better or for worse. By involving a child's peers in his therapy, their influence can be made to be consistently positive. By establishing tailor-made peer-therapy groups, the child psychologist will increase his therapeutic impact. Among the possible formats for involving peers in a child's treatment…

  7. LPWA using supersonic gas jet with tailored density profile

    Science.gov (United States)

    Kononenko, O.; Bohlen, S.; Dale, J.; D'Arcy, R.; Dinter, M.; Erbe, J. H.; Indorf, G.; di Lucchio, L.; Goldberg, L.; Gruse, J. N.; Karstensen, S.; Libov, V.; Ludwig, K.; Martinez de La Ossa, A.; Marutzky, F.; Niroula, A.; Osterhoff, J.; Quast, M.; Schaper, L.; Schwinkendorf, J.-P.; Streeter, M.; Tauscher, G.; Weichert, S.; Palmer, C.; Horbatiuk, Taras

    2016-10-01

    Laser driven plasma wakefield accelerators have been explored as a potential compact, reproducible source of relativistic electron bunches, utilising an electric field of many GV/m. Control over injection of electrons into the wakefield is of crucial importance in producing stable, mono-energetic electron bunches. Density tailoring of the target, to control the acceleration process, can also be used to improve the quality of the bunch. By using gas jets to provide tailored targets it is possible to provide good access for plasma diagnostics while also producing sharp density gradients for density down-ramp injection. OpenFOAM hydrodynamic simulations were used to investigate the possibility of producing tailored density targets in a supersonic gas jet. Particle-in-cell simulations of the resulting density profiles modelled the effect of the tailored density on the properties of the accelerated electron bunch. Here, we present the simulation results together with preliminary experimental measurements of electron and x-ray properties from LPWA experiments using gas jet targets and a 25 TW, 25 fs Ti:Sa laser system at DESY.

  8. Genomic markers to tailor treatments: waiting or initiating?

    NARCIS (Netherlands)

    P. Tajik; P.M. Bossuyt

    2011-01-01

    The decade since the publication of the Human Genome Project draft has ended with the discovery of hundreds of genomic markers related to diseases and phenotypes. However, the project has not yet delivered on its promise to tailor treatments for individuals. The number of genomic markers in clinical

  9. Aeroelastic tailoring in wind-turbine blade applications

    Energy Technology Data Exchange (ETDEWEB)

    Veers, P.; Lobitz, D. [Sandia National Labs., Albuquerque, NM (United States); Bir, G. [National Renewable Energy Lab., Golden, CO (United States). National Wind Technology Center

    1998-04-01

    This paper reviews issues related to the use of aeroelastic tailoring as a cost-effective, passive means to shape the power curve and reduce loads. Wind turbine blades bend and twist during operation, effectively altering the angle of attack, which in turn affects loads and energy production. There are blades now in use that have significant aeroelastic couplings, either on purpose or because of flexible and light-weight designs. Since aeroelastic effects are almost unavoidable in flexible blade designs, it may be desirable to tailor these effects to the authors advantage. Efforts have been directed at adding flexible devices to a blade, or blade tip, to passively regulate power (or speed) in high winds. It is also possible to build a small amount of desirable twisting into the load response of a blade with proper asymmetric fiber lay up in the blade skin. (Such coupling is akin to distributed {delta}{sub 3} without mechanical hinges.) The tailored twisting can create an aeroelastic effect that has payoff in either better power production or in vibration alleviation, or both. Several research efforts have addressed different parts of this issue. Research and development in the use of aeroelastic tailoring on helicopter rotors is reviewed. Potential energy gains as a function of twist coupling are reviewed. The effects of such coupling on rotor stability have been studied and are presented here. The ability to design in twist coupling with either stretching or bending loads is examined also.

  10. Towards tailored and targeted adherence assessment to optimise asthma management

    NARCIS (Netherlands)

    van Boven, Job F. M.; Trappenburg, Jaap C. A.; van der Molen, Thys; Chavannes, Niels H.

    2015-01-01

    In this paper, we aim to emphasise the need for a more comprehensive and tailored approach to manage the broad nature of non-adherence, to personalise current asthma management. Although currently several methods are available to measure the extent of asthma patients' adherence, the vast majority do

  11. Tailoring Dispersion properties of photonic crystal waveguides by topology optimization

    DEFF Research Database (Denmark)

    Stainko, Roman; Sigmund, Ole

    2007-01-01

    based design updates. The goal of the optimization process is to come up with slow light, zero group velocity dispersion photonic waveguides or photonic waveguides with tailored dispersion properties for dispersion compensation purposes. Two examples concerning reproduction of a specific dispersion...

  12. Information Tailoring Enhancements for Large-Scale Social Data

    Science.gov (United States)

    2016-06-15

    1 Work Performed within This Reporting Period .................................................... 2 1.1 Enhanced Named Entity Recognition (NER...Social Data Progress Report No. 3 Reporting Period: March 16, 2016 – June 15, 2016 Contract No. N00014-15-P-5138 Sponsored by ONR...Automation Incorporated Progress Report No. 3 Information Tailoring Enhancements for Large-Scale Social Data Submitted in accordance with

  13. Automated Finite Element Analysis of Elastically-Tailored Plates

    Science.gov (United States)

    Jegley, Dawn C. (Technical Monitor); Tatting, Brian F.; Guerdal, Zafer

    2003-01-01

    A procedure for analyzing and designing elastically tailored composite laminates using the STAGS finite element solver has been presented. The methodology used to produce the elastic tailoring, namely computer-controlled steering of unidirectionally reinforced composite material tows, has been reduced to a handful of design parameters along with a selection of construction methods. The generality of the tow-steered ply definition provides the user a wide variety of options for laminate design, which can be automatically incorporated with any finite element model that is composed of STAGS shell elements. Furthermore, the variable stiffness parameterization is formulated so that manufacturability can be assessed during the design process, plus new ideas using tow steering concepts can be easily integrated within the general framework of the elastic tailoring definitions. Details for the necessary implementation of the tow-steering definitions within the STAGS hierarchy is provided, and the format of the ply definitions is discussed in detail to provide easy access to the elastic tailoring choices. Integration of the automated STAGS solver with laminate design software has been demonstrated, so that the large design space generated by the tow-steering options can be traversed effectively. Several design problems are presented which confirm the usefulness of the design tool as well as further establish the potential of tow-steered plies for laminate design.

  14. Heliostat glass survey and evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Lind, M. A.; Russin, J. M.

    1978-01-01

    The glass characterization and specification task included a comprehensive survey of both foreign and domestic sources of low distortion, low iron, .125 nominal flat glass for use in heliostat applications. PNL attempted to determine the availability of production lines, estimate industry interest, lead times, and costs for producing glass for second surface heliostat mirrors for the Barstow pilot plant and future commercial plants. Glass samples representative of the industry production capability were collected and characterized. The results of the survey and analysis were used to generate a specification for the Barstow Pilot Plant glass procurement.

  15. Ceramic nanoparticle assemblies with tailored shapes and tailored chemistries via biosculpting and shape-preserving inorganic conversion.

    Science.gov (United States)

    Dickerson, M B; Naik, R R; Sarosi, P M; Agarwal, G; Stone, M O; Sandhage, K H

    2005-01-01

    A novel biosynthetic paradigm is introduced for fabricating three-dimensional (3-D) ceramic nanoparticle assemblies with tailored shapes and tailored chemistries: biosculpting and shape-preserving inorganic conversion (BaSIC). Biosculpting refers to the use of biomolecules that direct the precipitation of ceramic nanoparticles to form a continuous 3-D structure with a tailored shape. We used a peptide derived from a diatom (a type of unicellular algae) to biosculpt silica nanoparticle based assemblies that, in turn, were converted into a new (nonsilica) composition via a shape-preserving gas/silica displacement reaction. Interwoven, microfilamentary silica structures were prepared by exposing a peptide, derived from the silaffin-1A protein of the diatom Cylindrotheca fusiformis, to a tetramethylorthosilicate solution under a linear shear flow condition. Subsequent exposure of the silica microfilaments to magnesium gas at 900 degrees C resulted in conversion into nanocrystalline magnesium oxide microfilaments with a retention of fine (submicrometer) features. Fluid(gas or liquid)/silica displacement reactions leading to a variety of other oxides have also been identified. This hybrid (biogenic/synthetic) approach opens the door to biosculpted ceramic microcomponents with multifarious tailored shapes and compositions for a wide range of environmental, aerospace, biomedical, chemical, telecommunications, automotive, manufacturing, and defense applications.

  16. Stedim 6 and Clearflex, two new multilayer materials for infusion containers. Comparative study of their compatibility with five drugs versus glass flasks and polyvinyl chloride bags.

    Science.gov (United States)

    Tchiakpé, L; Airaudo, C B; Abdelmalik, O M; Gayte-Sorbier, A; Verdier, M; Guerri, J

    1995-01-01

    Stedim 6 and Clearflex, two new polyethylene-lined materials for infusion bags, were studied for their compatibility with disodium clodronate, chlorpromazine and maprotiline hydrochlorides, diazepam, and clorazepate dipotassium salt, comparatively with borosilicate glass flasks and polyvinyl chloride bags. Diazepam, the only drug to exhibit a marked sorption in PVC bags (the loss reached 25% of the initial concentration after a contact duration of 72 h), showed lower sorption in Stedim 6 bags (loss about 11% under the same conditions) and none in Clearflex bags. No significant difference was observed between the infusion solutions used as vehicles of the drugs (5% dextrose and 0.9% sodium chloride isotonic solutions). The results are discussed in terms of lipophilicity of the drugs and crystallinity of the polymers.

  17. Low thermal expansion glass ceramics

    CERN Document Server

    1995-01-01

    This book is one of a series reporting on international research and development activities conducted by the Schott group of companies With the series, Schott aims to provide an overview of its activities for scientists, engineers, and managers from all branches of industry worldwide where glasses and glass ceramics are of interest Each volume begins with a chapter providing a general idea of the current problems, results, and trends relating to the subjects treated This volume describes the fundamental principles, the manufacturing process, and applications of low thermal expansion glass ceramics The composition, structure, and stability of polycrystalline materials having a low thermal expansion are described, and it is shown how low thermal expansion glass ceramics can be manufactured from appropriately chosen glass compositions Examples illustrate the formation of this type of glass ceramic by utilizing normal production processes together with controlled crystallization Thus glass ceramics with thermal c...

  18. Production of glass or glass-ceramic to metal seals with the application of pressure

    Science.gov (United States)

    Kelly, M.D.; Kramer, D.P.

    1985-01-04

    In a process for preparing a glass or glass-ceramic to metal seal comprising contacting the glass with the metal and heat-treating the glass and metal under conditions whereby the glass to metal seal is effected and, optionally, the glass is converted to a glass-ceramic, an improvement comprises carrying out the heat-treating step using hot isostatic pressing.

  19. Breaking the glass ceiling.

    Science.gov (United States)

    Lazarus, A

    1997-03-01

    The glass ceiling is a form of organizational bias and discrimination that prevents qualified professionals from achieving positions of top governance and leadership. This article examines glass ceiling barriers that keep physicians from the upper reaches of management. While these factors apply mainly to women and minority physicians in academia, and are attributable to sexual harassment and discrimination, physicians as a class are frequently denied executive management positions. Such denial results from inadequate preparation for a career in health care administration. Important issues in the professional development of physician executives include mentoring, training and education, administrative experience, and cultural and personality factors. All of those must be considered when making the transition from medicine to management.

  20. Glasses for Mali

    CERN Multimedia

    PH Department

    2008-01-01

    We are collecting old pairs of glasses to take out to Mali, where they can be re-used by people there. The price for a pair of glasses can often exceed 3 months salary, so they are prohibitively expensive for many people. If you have any old spectacles you can donate, please put them in the special box in the ATLAS secretariat, Bldg.40-4-D01 before the Christmas closure on 19 December so we can take them with us when we leave for Africa at the end of the month. (more details in ATLAS e-news edition of 29 September 2008: http://atlas-service-enews.web.cern.ch/atlas-service-enews/news/news_mali.php) many thanks! Katharine Leney co-driver of the ATLAS car on the Charity Run to Mali

  1. Low-loss, high performance hybrid photonics devices enabled by ion-exchanged glass waveguides

    Science.gov (United States)

    Araci, Ismail Emre

    Robust ion-exchanged glass waveguides exhibit low optical losses in a broad spectral range and they allow integration of several devices on the same chip due to their planar structure. Consequently, they can be a low cost alternative to semiconductors for fabricating various integrated optical devices. Two high performance photonic devices were designed and realized, demonstrating the potential of glass waveguides. The well-controlled silver-film ion-exchange process allowed the fabrication of: i) a highly sensitive biosensor based on optical absorption and, ii) a low loss hybrid electro-optic (EO) polymer modulator with a narrow coplanar electrode gap. The single-mode, channel integrated optical ion-exchange waveguide on borosilicate glass (Corning 0211) is described for broad spectral band (400-650 nm) detection and analysis of heme-containing protein films at a glass/water interface. The evanescent wave interaction is improved significantly by fabricating ion-exchange waveguides with a step-like index profile. Silver nano-particle formation is reduced in order to achieve low loss in the Soret-band (˜400 nm). Unlike other surface-specific techniques (e.g. SPR, interferometry) that probe local refractive-index changes and therefore are susceptible to temperature fluctuations, the integrated optical waveguide absorption technique probes molecular-specific transition bands and is expected to be less vulnerable to environmental perturbations. The hybrid integration of phosphate glass (IOG-1) and EO polymer is realized for the first time. The critical alignment steps which are typically required for hybrid optoelectronic devices are eliminated with a simple alignment-free fabrication technique. The low loss adiabatic transition from glass to EO polymer waveguide is enabled by gray scale patterning of the novel EO polymer, AJLY. Total insertion loss of 5 dB and electrode gap of 8 mum is obtained for an optimized device design. EO polymer poling at 135 °C and 75 V

  2. Supersymmetric Spin Glass

    CERN Document Server

    Gukov, S G

    1997-01-01

    The evidently supersymmetric four-dimensional Wess-Zumino model with quenched disorder is considered at the one-loop level. The infrared fixed points of a beta-function form the moduli space $M = RP^2$ where two types of phases were found: with and without replica symmetry. While the former phase possesses only a trivial fixed point, this point become unstable in the latter phase which may be interpreted as a spin glass phase.

  3. Exploration and Modeling of Structural changes in Waste Glass Under Corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Pantano, Carlos; Ryan, Joseph; Strachan, Denis

    2013-11-10

    Vitrification is currently the world-wide treatment of choice for the disposition of high-level nuclear wastes. In glasses, radionuclides are atomistically bonded into the solid, resulting in a highly durable product, with borosilicate glasses exhibiting particularly excellent durability in water. Considering that waste glass is designed to retain the radionuclides within the waste form for long periods, it is important to understand the long-term stability of these materials when they react in the environment, especially in the presence of water. Based on a number of previous studies, there is general consensus regarding the mechanisms controlling the initial rate of nuclear waste glass dissolution. Agreement regarding the cause of the observed decrease in dissolution rate at extended times, however, has been elusive. Two general models have been proposed to explain this behavior, and it has been concluded that both concepts are valid and must be taken into account when considering the decrease in dissolution rate. Furthermore, other processes such as water diffusion, ion exchange, and precipitation of mineral phases onto the glass surface may occur in parallel with dissolution of the glass and can influence long-term performance. Our proposed research will address these issues through a combination of aqueous-phase dissolution/reaction experiments and probing of the resulting surface layers with state-of-the-art analytical methods. These methods include solid-state nuclear magnetic resonance (SSNMR) and time-of-flight secondary ion mass spectrometry (TOF-SIMS). The resulting datasets will then be coupled with computational chemistry and reaction-rate modeling to address the most persistent uncertainties in the understanding of glass corrosion, which indeed have limited the performance of the best corrosion models to date. With an improved understanding of corrosion mechanisms, models can be developed and improved that, while still conservative, take advantage of

  4. Structural and magnetic properties of "thick" microwires produced by the modernized Ulitovsky-Tailor method

    Science.gov (United States)

    Shalygina, E. E.; Kharlamova, A. M.; Shalygin, A. N.; Molokanov, V. V.; Umnov, P. P.; Umnova, N. V.; Chueva, T. R.

    2016-10-01

    In this article the results on the detailed investigation of the structural, elastic and magnetic properties of the "thick" Fe73,5Si13,5B9Nb3Cu1 and Fe31Co34Ni10(SiB)25 amorphous microwires with the glass shell, produced by the modernized Ulitovsky-Tailor method, are presented. The diameter of the metallic core of microwires was varied from 50 to 200 μm. It was found that the core has the stable geometric parameters along the microwire length and the smooth (almost without defects) surface. The studied samples are characterized by the weak dispersion of magnetic anisotropy of the near-surface layers and the high homogeneity of the near-surface local magnetic properties. Furthermore, the microwires exhibit the high plasticity and strength. They are not destroyed even after their full tightening into a knot. The strong influence of tensile stress and torsion on the magnetic properties of the microwires was discovered. The comparison of magneto-field behavior of the studied samples was performed.

  5. Defense Waste Processing Facility (DWPF) Durability-Composition Models and the Applicability of the Associated Reduction of Constraints (ROC) Criteria for High TiO2 Containing Glasses

    Energy Technology Data Exchange (ETDEWEB)

    Jantzen, C. M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Edwards, T. B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Trivelpiece, C. L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-08-30

    Radioactive high level waste (HLW) at the Savannah River Site (SRS) has successfully been vitrified into borosilicate glass in the DWPF since 1996. Vitrification requires stringent product/process (P/P) constraints since the glass cannot be reworked once it has been poured into ten foot tall by two foot diameter canisters. A unique “feed forward” statistical process control (SPC) was developed for this control rather than relying on statistical quality control (SQC). In SPC, the feed composition to the DWPF melter is controlled prior to vitrification. In SQC, the glass product would be sampled after it is vitrified. Individual glass property-composition models form the basis for the “feed forward” SPC. The models transform constraints on the melt and glass properties into constraints on the feed composition going to the melter in order to determine, at the 95% confidence level, that the feed will be processable and that the durability of the resulting waste form will be acceptable to a geologic repository.

  6. Transferability of glass lens molding

    Science.gov (United States)

    Katsuki, Masahide

    2006-02-01

    Sphere lenses have been used for long time. But it is well known that sphere lenses theoretically have spherical aberration, coma and so on. And, aspheric lenses attract attention recently. Plastic lenses are molded easily with injection machines, and are relatively low cost. They are suitable for mass production. On the other hand, glass lenses have several excellent features such as high refractive index, heat resistance and so on. Many aspheric glass lenses came to be used for the latest digital camera and mobile phone camera module. It is very difficult to produce aspheric glass lenses by conventional process of curve generating and polishing. For the solution of this problem, Glass Molding Machine was developed and is spreading through the market. High precision mold is necessary to mold glass lenses with Glass Molding Machine. The mold core is ground or turned by high precision NC aspheric generator. To obtain higher transferability of the mold core, the function of the molding machine and the conditions of molding are very important. But because of high molding temperature, there are factors of thermal expansion and contraction of the mold and glass material. And it is hard to avoid the factors. In this session, I introduce following items. [1] Technology of glass molding and the machine is introduced. [2] The transferability of glass molding is analyzed with some data of glass lenses molded. [3] Compensation of molding shape error is discussed with examples.

  7. Dopant concentration and thermoluminescence (TL) properties of tailor-made Ge-doped SiO2 fibres

    Science.gov (United States)

    Zahaimi, Nurul Arina; Ooi Abdullah, Mohd Haris Ridzuan; Zin, Hafiz; Abdul Rahman, Ahmad Lutfi; Hashim, Suhairul; Saripan, Mohd Iqbal; Paul, Mukul Chandra; Bradley, D. A.; Abdul Rahman, Ahmad Taufek

    2014-11-01

    Study focuses on characterisation of diverse concentrations of Ge-doped SiO2 fibre as a potential thermoluminescence (TL) system for radiotherapy dosimetry. Irradiations were made using a linear accelerator providing 6 MV and 10 MV photon beams. Investigation has been done on various doped core diameter Ge-doped SiO2 glass fibres such as commercial telecommunication fibres of 8 μm and 9 μm (CorActive High Tech, Canada), tailor-made fibres of 23 and 50 μm produced by the Central Glass and Ceramic Research Institute Kolkata, and tailor-made fibres of 11 μm produced by the University of Malaya Photonics Research Centre. The fibres have been characterised for TL sensitivity, reproducibility, dose- and energy-dependence. The area under the TL glow curve increases with increasing core diameter. For repeat irradiations at a fixed dose the dosimeter produces a flat response better than 4% (1SD) of the mean of the TL distribution. Minimal TL signal fading was found, less than 0.5% per day post irradiation. Linearity of TL has been observed with a correlation coefficient (r2) of better than 0.980 (at 95% confidence level). For particular dopant concentrations, the least square fits show the change in TL yield, in counts per second per unit mass, obtained from 50 μm core diameter fibres irradiated at 6 MV of photon to be 8 times greater than that of 8 μm core diameter fibre. With respect to energy response, the TL yield at 10 MV decreases by~5% compared to that at 6 MV, primarily due to the lower mass energy absorption coefficient at higher photon energy. These early results indicate that selectively screened fibres can be developed into a promising TL system, offering high spatial resolution capability and, with this, verification of complex radiotherapy dose distributions.

  8. Analytical Plan for Roman Glasses

    Energy Technology Data Exchange (ETDEWEB)

    Strachan, Denis M.; Buck, Edgar C.; Mueller, Karl T.; Schwantes, Jon M.; Olszta, Matthew J.; Thevuthasan, Suntharampillai; Heeren, Ronald M.

    2011-01-01

    Roman glasses that have been in the sea or underground for about 1800 years can serve as the independent “experiment” that is needed for validation of codes and models that are used in performance assessment. Two sets of Roman-era glasses have been obtained for this purpose. One set comes from the sunken vessel the Iulia Felix; the second from recently excavated glasses from a Roman villa in Aquileia, Italy. The specimens contain glass artifacts and attached sediment or soil. In the case of the Iulia Felix glasses quite a lot of analytical work has been completed at the University of Padova, but from an archaeological perspective. The glasses from Aquileia have not been so carefully analyzed, but they are similar to other Roman glasses. Both glass and sediment or soil need to be analyzed and are the subject of this analytical plan. The glasses need to be analyzed with the goal of validating the model used to describe glass dissolution. The sediment and soil need to be analyzed to determine the profile of elements released from the glass. This latter need represents a significant analytical challenge because of the trace quantities that need to be analyzed. Both pieces of information will yield important information useful in the validation of the glass dissolution model and the chemical transport code(s) used to determine the migration of elements once released from the glass. In this plan, we outline the analytical techniques that should be useful in obtaining the needed information and suggest a useful starting point for this analytical effort.

  9. Endometrial adenocarcinoma, adjuvant radiotherapy tailored to prognostic factors.

    Science.gov (United States)

    Meerwaldt, J H; Hoekstra, C J; van Putten, W L; Tjokrowardojo, A J; Koper, P C

    1990-02-01

    The optimal adjuvant radiotherapy for surgically treated endometrial cancer has not yet been defined. We report on 389 patients treated between 1970 and 1985 with adjuvant radiotherapy. The treatment was tailored to the known prognostic factors: myometrial invasion and grade of differentiation of the tumor. Ten-year overall survival was 67%, 10-year relapse-free survival 77%; 23% relapse, of which 21% distant and 6% locoregional relapse. In a multivariate analysis, stage (pT), grade, and myometrial invasion were prognostic factors. The number of locoregional failures was very small (n = 23). This small number, the fact that radiation treatment was tailored to prognostic factors, and the absence of a nontreated control group precluded an analysis of the effect of the adjuvant irradiation. Large randomized studies with a control (no treatment) arm should be performed to determine the value of adjuvant radiotherapy.

  10. PULSED MODE LASER CUTTING OF SHEETS FOR TAILORED BLANKS

    DEFF Research Database (Denmark)

    Bagger, Claus; Olsen, Flemming Ove

    1999-01-01

    This paper describes how the laser cutting process can be optimised in such a way that the cut sheets can subsequently be used to laser weld tailored blanks. In a number of systematic laboratory experiments the effect of cutting speed, assist gas pressure, average laser power and pulse energy...... was analysed. For quality assessment the squareness, roughness and dross attachment of laser cut blanks were measured. In all tests, the medium strength steel GA 260 with a thickness of 1.8 mm was used. In this work it has been successfully demonstrated that the squareness of a cut can be used as a quality...... item for parameter optimisation of laser cut sheets used for tailored blanks. It was concluded that high quality cut edges with a squareness as small as 0.015 mm may be obtained. Such edges are well suited for subsequent laser welding....

  11. FSW of Aluminum Tailor Welded Blanks across Machine Platforms

    Energy Technology Data Exchange (ETDEWEB)

    Hovanski, Yuri; Upadhyay, Piyush; Carlson, Blair; Szymanski, Robert; Luzanski, Tom; Marshall, Dustin

    2015-02-16

    Development and characterization of friction stir welded aluminum tailor welded blanks was successfully carried out on three separate machine platforms. Each was a commercially available, gantry style, multi-axis machine designed specifically for friction stir welding. Weld parameters were developed to support high volume production of dissimilar thickness aluminum tailor welded blanks at speeds of 3 m/min and greater. Parameters originally developed on an ultra-high stiffness servo driven machine where first transferred to a high stiffness servo-hydraulic friction stir welding machine, and subsequently transferred to a purpose built machine designed to accommodate thin sheet aluminum welding. The inherent beam stiffness, bearing compliance, and control system for each machine were distinctly unique, which posed specific challenges in transferring welding parameters across machine platforms. This work documents the challenges imposed by successfully transferring weld parameters from machine to machine, produced from different manufacturers and with unique control systems and interfaces.

  12. Highly tailorable thiol-ene based emulsion-templated monoliths

    DEFF Research Database (Denmark)

    Lafleur, J. P.; Kutter, J. P.

    2014-01-01

    The attractive surface properties of thiol-ene polymers combined with their ease of processing make them ideal substrates in many bioanalytical applications. We report the synthesis of highly tailorable emulsion-templated porous polymers and beads in microfluidic devices based on off-stoichiometr......The attractive surface properties of thiol-ene polymers combined with their ease of processing make them ideal substrates in many bioanalytical applications. We report the synthesis of highly tailorable emulsion-templated porous polymers and beads in microfluidic devices based on off......-stoichiometry thiolene chemistry. The method allows monolith synthesis and anchoring inside thiol-ene microchannels in a single step. Variations in the monomer stoichiometric ratios and/or amount of porogen used allow for the creation of extremely varied polymer morphologies, from foam-like materials to dense networks...

  13. The effect of laser pulse tailored welding of Inconel 718

    Science.gov (United States)

    Mccay, T. Dwayne; Mccay, Mary Helen; Sharp, C. Michael; Womack, Michael G.

    1990-01-01

    Pulse tailored laser welding has been applied to wrought, wrought grain grown, and cast Inconel 718 using a CO2 laser. Prior to welding, the material was characterized metallographically and the solid state transformation regions were identified using Differential Scanning Calorimetry and high temperature x-ray diffraction. Bead on plate welds (restrained and unrestrained) were then produced using a matrix of pulse duty cycles and pulsed average power. Subsequent characterization included heat affected zone width, penetration and underbead width, the presence of cracks, microfissures and porosity, fusion zone curvature, and precipitation and liquated region width. Pedigree welding on three selected processing conditions was shown by microstructural and dye penetrant analysis to produce no microfissures, a result which strongly indicates the viability of pulse tailored welding for microfissure free IN 718.

  14. A tailorable infrastructure to enhance mobile seamless learning

    DEFF Research Database (Denmark)

    Malandrino, Delfina; Manno, Ilaria; Palmieri, Giuseppina

    2015-01-01

    The widespread use of mobile devices is leading towards their adoption in the learning process, even if some pedagogical challenges are still not fully addressed when integrating mobile-assisted activities into regular curricula activities. In this paper, we first define some guidelines to design...... a general, tailorable, and platform-independent mobile learning system. Second, we present the aCME system, a mobile infrastructure, developed by adhering to the defined guidelines, to provide a general-purpose system, easy to start up with and friendly to user, and finally, tailorable, i.e., that can...... be easily adapted to the needs of different learning environments. The aCME system has been implemented as a Web-based architecture, to provide content and functionalities for different contexts, accessible from any location and by using any communication device. Finally, we describe a tool, deployed into a...

  15. Tailor-made fructan synthesis in plants: a review.

    Science.gov (United States)

    van Arkel, Jeroen; Sévenier, Robert; Hakkert, Johanna C; Bouwmeester, Harro J; Koops, Andries J; van der Meer, Ingrid M

    2013-03-01

    Fructan, a fructose polymer, is produced by many bacteria and plants. Fructan is used as carbohydrate reserve, and in bacteria also as protective outside layer. Chicory is a commercial fructan producing crop. The disadvantage of this crop is its fructan breakdown before harvest. Studies using genetically modification showed that fructan biosynthesis is difficult to steer in chicory. Alternatives for production of tailor-made fructan, fructan with a desired polymer length and linkage type, are originally non-fructan-accumulating plants expressing introduced fructosyltransferase genes. The usage of bacterial fructosyltransferases hindered plant performance, whereas plant-derived fructan genes can successfully be used for this purpose. The polymer length distribution and the yield are dependent on the origin of the fructan genes and the availability of sucrose in the host. Limitations seen in chicory for the production of tailor-made fructan are lacking in putative new platform crops like sugar beet and sugarcane and rice.

  16. Tailoring self-assembled monolayers at the electrochemical interface

    Indian Academy of Sciences (India)

    S Varatharajan; Sheela Berchmans; V Yegnaraman

    2009-09-01

    The main focus of this review is to illustrate the amenability of self-assembled monolayers (SAMs) for functionalisation with different receptors, catalytic materials, biomolecules, enzymes, antigen-antibody, etc for various applications. The review discusses initially about the preparation and characterization of SAMs and tailoring of SAMs by incorporation of suitable recognition elements. A description of how the molecular recognition is achieved through forces like electrostatic, covalent and host-guest interactions is included in the review.

  17. Glass ceramic ZERODUR enabling nanometer precision

    Science.gov (United States)

    Jedamzik, Ralf; Kunisch, Clemens; Nieder, Johannes; Westerhoff, Thomas

    2014-03-01

    The IC Lithography roadmap foresees manufacturing of devices with critical dimension of glass ceramic ZERODUR® is a well-established material in critical components of microlithography wafer stepper and offered with an extremely low coefficient of thermal expansion (CTE), the tightest tolerance available on market. SCHOTT is continuously improving manufacturing processes and it's method to measure and characterize the CTE behavior of ZERODUR® to full fill the ever tighter CTE specification for wafer stepper components. In this paper we present the ZERODUR® Lithography Roadmap on the CTE metrology and tolerance. Additionally, simulation calculations based on a physical model are presented predicting the long term CTE behavior of ZERODUR® components to optimize dimensional stability of precision positioning devices. CTE data of several low thermal expansion materials are compared regarding their temperature dependence between - 50°C and + 100°C. ZERODUR® TAILORED 22°C is full filling the tight CTE tolerance of +/- 10 ppb / K within the broadest temperature interval compared to all other materials of this investigation. The data presented in this paper explicitly demonstrates the capability of ZERODUR® to enable the nanometer precision required for future generation of lithography equipment and processes.

  18. Laser driven self-assembly of shape-controlled potassium nanoparticles in porous glass

    CERN Document Server

    Marmugi, L; Burchianti, A; Veronesi, S; Moi, L; Marinelli, C

    2014-01-01

    We observe growth of shape-controlled potassium nanoparticles inside a random network of glass nanopores, exposed to low-power laser radiation. Visible laser light plays a dual role: it increases the desorption probability of potassium atoms from the inner glass walls and induces the self-assembly of metastable metallic nanoparticles along the nanopores. By probing the sample transparency and the atomic light-induced desorption flux into the vapour phase, the dynamics of both cluster formation/evaporation and atomic photo-desorption processes are characterized. Results indicate that laser light not only increases the number of nanoparticles embedded in the glass matrix but also influences their structural properties. By properly choosing the laser frequency and the illumination time, we demonstrate that it is possible to tailor the nanoparticles'shape distribution. Furthermore, a deep connection between the macroscopic behaviour of atomic desorption and light-assisted cluster formation is observed. Our result...

  19. Properties of glass/carbon fiber reinforced epoxy hybrid polymer composites

    Science.gov (United States)

    Patel, R. H.; Sevkani, V. R.; Patel, B. R.; Patel, V. B.

    2016-05-01

    Composite Materials are well known for their tailor-made properties. For the fabrication of composites different types of reinforcements are used for different applications. Sometimes for a particular application, one type of reinforcement may not fulfill the requirements. Therefore, more than one type of reinforcements may be used. Thus, the idea of hybrid composites arises. Hybrid composites are made by joining two or more different reinforcements with suitable matrix system. It helps to improve the properties of composite materials. In the present work glass/carbon fiber reinforcement have been used with a matrix triglycidyl ether of tris(m-hydroxy phenyl) phosphate epoxy resin using amine curing agent. Different physical and mechanical properties of the glass, carbon and glass/carbon fiber reinforced polymeric systems have been found out.

  20. Evaluating Psychosocial and Behavioral Mechanisms of Change in a Tailored Communication Intervention

    Science.gov (United States)

    Elder, John P.; Ayala, Guadalupe X.; Slymen, Donald J.; Arredondo, Elva M.; Campbell, Nadia R.

    2009-01-01

    This study examined the impact of a tailored nutrition intervention at 3 and 6 months postintervention. In all, 357 Latinas were randomly assigned to one of three conditions: (1) a control condition comprised of previously developed Spanish language targeted materials, (2) tailored print materials, or (3) tailored print materials accompanied by…

  1. Noise tailoring for scalable quantum computation via randomized compiling

    Science.gov (United States)

    Wallman, Joel J.; Emerson, Joseph

    2016-11-01

    Quantum computers are poised to radically outperform their classical counterparts by manipulating coherent quantum systems. A realistic quantum computer will experience errors due to the environment and imperfect control. When these errors are even partially coherent, they present a major obstacle to performing robust computations. Here, we propose a method for introducing independent random single-qubit gates into the logical circuit in such a way that the effective logical circuit remains unchanged. We prove that this randomization tailors the noise into stochastic Pauli errors, which can dramatically reduce error rates while introducing little or no experimental overhead. Moreover, we prove that our technique is robust to the inevitable variation in errors over the randomizing gates and numerically illustrate the dramatic reductions in worst-case error that are achievable. Given such tailored noise, gates with significantly lower fidelity—comparable to fidelities realized in current experiments—are sufficient to achieve fault-tolerant quantum computation. Furthermore, the worst-case error rate of the tailored noise can be directly and efficiently measured through randomized benchmarking protocols, enabling a rigorous certification of the performance of a quantum computer.

  2. Tailor cutting of crystalline solar cells by laser micro jet

    Science.gov (United States)

    Bruckert, F.; Pilat, E.; Piron, P.; Torres, P.; Carron, B.; Richerzhagen, B.; Pirot, M.; Monna, R.

    2012-03-01

    Coupling a laser into a hair thin water micro jet (Laser Micro Jet, LMJ) for cutting applications offers a wide range of processes that are quite unique. As the laser beam is guided by internal reflections inside of a liquid cylinder, the cuts are naturally straight and do not reflect any divergence as otherwise occurs with an unguided laser beam. Furthermore, having a liquid media at the point of contact ensures a fast removal of heat and eventual debris ensuring clean cuts, which are free of any burrs. Many applications have indeed been developed for a large variety of materials, which are as different as e.g. diamond, silicon, aluminum, ceramic and hard metals. The photovoltaic industry has enjoyed in the last decades tremendous growth rates, which are still projected into the future. We focus here on the segment of Building Integrated PV (BIPV), which requests tailored solutions to actual buildings and not-one-fits-it-all standardized modules. Having the option to tailor cut solar cells opens a new field of BIPV applications. For the first time, finished crystalline solar cells have been LMJ cut into predetermined shapes. First results show that the cut is clean and neat. Preliminary solar performance measurements are positive. This opens a new avenue of tailored made modules instead of having to rely on the one-fits-alloy approach used so far.

  3. Manganite/Cuprate Superlattice as Artificial Reentrant Spin Glass

    KAUST Repository

    Ding, Junfeng

    2016-05-04

    Emerging physical phenomena at the unit-cell-controlled interfaces of transition-metal oxides have attracted lots of interest because of the rich physics and application opportunities. This work reports a reentrant spin glass behavior with strong magnetic memory effect discovered in oxide heterostructures composed of ultrathin manganite La0.7Sr0.3MnO3 (LSMO) and cuprate La2CuO4 (LCO) layers. These heterostructures are featured with enhanced ferromagnetism before entering the spin glass state: a Curie temperature of 246 K is observed in the superlattice with six-unit-cell LSMO layers, while the reference LSMO film with the same thickness shows much weaker magnetism. Furthermore, an insulator-metal transition emerges at the Curie temperature, and below the freezing temperature the superlattices can be considered as a glassy ferromagnetic insulator. These experimental results are closely related to the interfacial spin reconstruction revealed by the first-principles calculations, and the dependence of the reentrant spin glass behavior on the LSMO layer thickness is in line with the general phase diagram of a spin system derived from the infinite-range SK model. The results of this work underscore the manganite/cuprate superlattices as a versatile platform of creating artificial materials with tailored interfacial spin coupling and physical properties. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Low Thermal Expansion Glass Ceramics

    CERN Document Server

    Bach, Hans

    2005-01-01

    This book appears in the authoritative series reporting the international research and development activities conducted by the Schott group of companies. This series provides an overview of Schott's activities for scientists, engineers, and managers from all branches of industry worldwide in which glasses and glass ceramics are of interest. Each volume begins with a chapter providing a general idea of the current problems, results, and trends relating to the subjects treated. This new extended edition describes the fundamental principles, the manufacturing process, and applications of low thermal expansion glass ceramics. The composition, structure, and stability of polycrystalline materials having a low thermal expansion are described, and it is shown how low thermal expansion glass ceramics can be manufactured from appropriately chosen glass compositions. Examples illustrate the formation of this type of glass ceramic by utilizing normal production processes together with controlled crystallization. Thus g...

  5. Photolithography-free laser-patterned HF acid-resistant chromium-polyimide mask for rapid fabrication of microfluidic systems in glass

    Science.gov (United States)

    Zamuruyev, Konstantin O.; Zrodnikov, Yuriy; Davis, Cristina E.

    2017-01-01

    Excellent chemical and physical properties of glass, over a range of operating conditions, make it a preferred material for chemical detection systems in analytical chemistry, biology, and the environmental sciences. However, it is often compromised with SU8, PDMS, or Parylene materials due to the sophisticated mask preparation requirements for wet etching of glass. Here, we report our efforts toward developing a photolithography-free laser-patterned hydrofluoric acid-resistant chromium-polyimide tape mask for rapid prototyping of microfluidic systems in glass. The patterns are defined in masking layer with a diode-pumped solid-state laser. Minimum feature size is limited to the diameter of the laser beam, 30 µm minimum spacing between features is limited by the thermal shrinkage and adhesive contact of the polyimide tape to 40 µm. The patterned glass substrates are etched in 49% hydrofluoric acid at ambient temperature with soft agitation (in time increments, up to 60 min duration). In spite of the simplicity, our method demonstrates comparable results to the other current more sophisticated masking methods in terms of the etched depth (up to 300 µm in borosilicate glass), feature under etch ratio in isotropic etch (~1.36), and low mask hole density. The method demonstrates high yield and reliability. To our knowledge, this method is the first proposed technique for rapid prototyping of microfluidic systems in glass with such high performance parameters. The proposed method of fabrication can potentially be implemented in research institutions without access to a standard clean-room facility.

  6. INCONEL 690 CORROSION IN WTP (WASTE TREATMENT PLANT) HLW (HIGH LEVEL WASTE) GLASS MELTS RICH IN ALUMINUM & BISMUTH & CHROMIUM OR ALUMINUM/SODIUM

    Energy Technology Data Exchange (ETDEWEB)

    KRUGER AA; FENG Z; GAN H; PEGG IL

    2009-11-05

    Metal corrosion tests were conducted with four high waste loading non-Fe-limited HLW glass compositions. The results at 1150 C (the WTP nominal melter operating temperature) show corrosion performance for all four glasses that is comparable to that of other typical borosilicate waste glasses, including HLW glass compositions that have been developed for iron-limited WTP streams. Of the four glasses tested, the Bi-limited composition shows the greatest extent of corrosion, which may be related to its higher phosphorus content. Tests at higher suggest that a moderate elevation of the melter operating temperature (up to 1200 C) should not result in any significant increase in Inconel corrosion. However, corrosion rates did increase significantly at yet higher temperatures (1230 C). Very little difference was observed with and without the presence of an electric current density of 6 A/inch{sup 2}, which is the typical upper design limit for Inconel electrodes. The data show a roughly linear relationship between the thickness of the oxide scale on the coupon and the Cr-depletion depth, which is consistent with the chromium depletion providing the material source for scale growth. Analysis of the time dependence of the Cr depletion profiles measured at 1200 C suggests that diffusion of Cr in the Ni-based Inconel alloy controls the depletion depth of Cr inside the alloy. The diffusion coefficient derived from the experimental data agrees within one order of magnitude with the published diffusion coefficient data for Cr in Ni matrices; the difference is likely due to the contribution from faster grain boundary diffusion in the tested Inconel alloy. A simple diffusion model based on these data predicts that Inconel 690 alloy will suffer Cr depletion damage to a depth of about 1 cm over a five year service life at 1200 C in these glasses.

  7. TIME-TEMPERATURE-TRANSFORMATION DIAGRAMS FOR THE SLUDGE BATCH 3 - FRIT 418 GLASS SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Billings, A; Tommy Edwards, T

    2009-03-03

    As a part of the Waste Acceptance Product Specifications (WAPS) for Vitrified High-Level Waste Forms defined by the Department of Energy - Office of Environmental Management, the phase stability must be determined for each of the projected high-level waste (HLW) types at the Savannah River Site (SRS). Specifically, WAPS 1.4.1 requires the glass transition temperature (Tg) to be defined and time-temperature-transformation (TTT) diagrams to be developed. The Tg of a glass is an indicator of the approximate temperature where the supercooled liquid converts to a solid on cooling or conversely, where the solid begins to behave as a viscoelastic solid on heating. A TTT diagram identifies the crystalline phases that can form as a function of time and temperature for a given waste type or more specifically, the borosilicate glass waste form. In order to assess durability, the Product Consistency Test (PCT) was used and the durability results compared to the Environmental Assessment (EA) glass. The measurement of glass transition temperature and the development of TTT diagrams have already been performed for the seven Defense Waste Processing Facility (DWPF) projected compositions as defined in the Waste Form Compliance Plan (WCP). These measurements were performed before DWPF start-up and the results were incorporated in Volume 7 of the Waste Form Qualification Report (WQR). Additional information exists for other projected compositions, but overall these compositions did not consider some of the processing scenarios now envisioned for DWPF to accelerate throughput. Changes in DWPF processing strategy have required this WAPS specification to be revisited to ensure that the resulting phases have been bounded. Frit 418 was primarily used to process HLW Sludge Batch 3 (SB3) at 38% waste loading (WL) through the DWPF. The Savannah River National Laboratory (SRNL) fabricated a cache of glass from reagent grade oxides to simulate the SB3-Frit 418 system at a 38 wt % WL for glass

  8. Fiberglass goes green: Developing phosphate glass for use in biodegradable composites

    Science.gov (United States)

    Arendt, Christina Lee

    Composite materials, such as the glass fiber reinforced polyester thermosets known as "fiberglass," are used in many applications. However, recycling processes for these materials are inefficient and not widely available. Specially engineered degradable polymers offer an opportunity to redesign these composites. Additionally, the composite could be tailored to be multi-use, such that upon degradation, the resulting products could be used as part of a zeoponic substrate (artificial soil) for growing plants. Such a material would be beneficial for long-duration space missions, terraforming, or in other agricultural applications. The research presented in this dissertation focuses on developing phosphate glass for use as the fiber reinforcement for such a composite. Due to the under-utilization of phosphate systems, there is a lack of thermodynamic data on these systems. The modified associate species method of phase diagram calculation was used in an attempt to gain more information about the desired system, as it is a good predictor of the phase relations in oxide melts, slags, and glasses and requires less data than other methods. Further research into the thermodynamic properties of phosphates is still needed to develop accurate phase diagrams and melting temperatures for this system. Seventeen glass formulations were developed and melted. Six of these formulations were chosen for dissolution testing. Of these six, Glass 17 was chosen for intensive testing and characterization. This glass was tested in water, hydrochloric acid solutions, and citric acid solutions. The weight loss was measured and ICP-OES was performed on the leachate solution. Scanning electron microscopy (SEM) and X-ray diffraction were performed on the tested specimens. Shrinking-core models were fit to the dissolution data. Fibers were drawn from the glass and characterized using SEM. The data shows that this glass is not dissolving congruently, as is expected of phosphate glasses. Instead

  9. Effect of winding layer and speed on kenaf/glass fiber hybrid reinforced acrylonitrile butadiene styrene (ABS) composites

    Science.gov (United States)

    Khoni, Norizzahthul Ainaa Abdul; Sharifah Shahnaz S., B.; Ghazali, Che Mohd Ruzaidi

    2016-07-01

    The usage of natural fiber is becoming significant in composite industries due to their good performance. Single and continuous natural fibers have relatively high mechanical properties; especially their young modulus can be as high as glass fibers. Filament winding is a method to produce technically aligned composites which have high fibers content. The properties of filament winding can be tailored to meet the end product requirements. This research studied the compression properties of kenaf/glass fibers hybrid reinforced composites. Kenaf/glass fibers hybrid composite samples were fabricated by filament winding technique and their properties were compared with the properties of neat kenaf fiber and glass fibers composites. The kenaf/glass fiber hybrid composites exhibited higher strength compared to the neat glass fibers composites. Composites of helical pattern, which produced at low winding speed showed better compression resistance than hoop pattern winding, which produced at high winding speed. As predicted, kenaf composite showed highest water absorption; followed by kenaf/glass fiber hybrid composites while neat glass fiber has lowest water absorption capability.

  10. Advances in Glass Ionomer Cements

    OpenAIRE

    KAYA, Dt. Tuğba; TİRALİ, Yard. Doç. Dr. Resmiye Ebru

    2013-01-01

    In recent years there have been a number of innovations and developments with respect to glass ionomer cements and their applications in clinical dentistry. This article considers some of the recent outstanding studies regarding the field of glass ionomer cement applications, adhesion and setting mechanisms, types, advantage and disadvantages among themselves and also to enhance the physical and antibacterial properties under the title of 'Advances in Glass Ionomer Cements'. As their biologic...

  11. Structural color from colloidal glasses

    Science.gov (United States)

    Magkiriadou, Sofia

    When a material has inhomogeneities at a lengthscale comparable to the wavelength of light, interference can give rise to structural colors: colors that originate from the interaction of the material's microstructure with light and do not require absorbing dyes. In this thesis we study a class of these materials, called photonic glasses, where the inhomogeneities form a dense and random arrangement. Photonic glasses have angle-independent structural colors that look like those of conventional dyes. However, when this work started, there was only a handful of colors accessible with photonic glasses, mostly hues of blue. We use various types of colloidal particles to make photonic glasses, and we study, both theoretically and experimentally, how the optical properties of these glasses relate to their structure and constituent particles. Based on our observations from glasses of conventional particles, we construct a theoretical model that explains the scarcity of yellow, orange, and red photonic glasses. Guided by this model, we develop novel colloidal systems that allow a higher degree of control over structural color. We assemble glasses of soft, core-shell particles with scattering cores and transparent shells, where the resonant wavelength can be tuned independently of the reflectivity. We then encapsulate glasses of these core-shell particles into emulsion droplets of tunable size; in this system, we observe, for the first time, angle-independent structural colors that cover the entire visible spectrum. To enhance color saturation, we begin experimenting with inverse glasses, where the refractive index of the particles is lower than the refractive index of the medium, with promising results. Finally, based on our theoretical model for scattering from colloidal glasses, we begin an exploration of the color gamut that could be achieved with this technique, and we find that photonic glasses are a promising approach to a new type of long-lasting, non-toxic, and

  12. Toughness of Bulk Metallic Glasses

    Directory of Open Access Journals (Sweden)

    Shantanu V. Madge

    2015-07-01

    Full Text Available Bulk metallic glasses (BMGs have desirable properties like high strength and low modulus, but their toughness can show much variation, depending on the kind of test as well as alloy chemistry. This article reviews the type of toughness tests commonly performed and the factors influencing the data obtained. It appears that even the less-tough metallic glasses are tougher than oxide glasses. The current theories describing the links between toughness and material parameters, including elastic constants and alloy chemistry (ordering in the glass, are discussed. Based on the current literature, a few important issues for further work are identified.

  13. Reactance to a tailored multimedia intervention encouraging teachers to promote cover-the-cough.

    Science.gov (United States)

    David, Prabu; Henry, Aletheia; Srivastava, Jatin; Orcena, Jason; Thrush, Jennifer

    2012-01-01

    Teachers were presented tailored multimedia messages encouraging them to offer cover-the-cough instruction to their students. Messages were tailored by grade level (elementary, higher grade) and stage of change (preaction, action). Among teachers in the action stages, message tailoring did not make a difference. Among teachers in the preaction stages, tailored messages were rated lower than were nontailored messages. The lower ratings of the tailored messages, seemingly a reactance response, did not carry over to postintervention self-efficacy. The intervention was effective in improving self-efficacy in elementary school teachers, particularly among those in the preaction stages.

  14. Light-induced atom desorption from glass surfaces characterized by X-ray photoelectron spectroscopy

    Science.gov (United States)

    Kumagai, Ryo; Hatakeyama, Atsushi

    2016-07-01

    We analyzed the surfaces of vitreous silica (quartz) and borosilicate glass (Pyrex) substrates exposed to rubidium (Rb) vapor by X-ray photoelectron spectroscopy (XPS) to understand the surface conditions of alkali metal vapor cells. XPS spectra indicated that Rb atoms adopted different bonding states in quartz and Pyrex. Furthermore, Rb atoms in quartz remained in the near-surface region, while they diffused into the bulk in Pyrex. For these characterized surfaces, we measured light-induced atom desorption (LIAD) of Rb atoms. Clear differences in time evolution, photon energy dependence, and substrate temperature dependence were found; the decay of LIAD by continuous ultraviolet irradiation for quartz was faster than that for Pyrex, a monotonic increase in LIAD with increasing photon energy from 1.8 to 4.3 eV was more prominent for quartz, and LIAD from quartz was more efficient at higher temperatures in the range from 300 to 580 K, while that from Pyrex was almost independent of temperature.

  15. Joints in Tempered Glass Using Glass Dowel Discs

    DEFF Research Database (Denmark)

    Nielsen, Jens Henrik; Poulsen, Peter Noe

    transparency of the glass. This is achieved by using a dowel disc made entirely of tempered glass. The concept of the joint is proved by pilot tests and numerical models. From the work it is seen that the load-carrying capacity of such a connection is similar to what is found for traditionally in-plane loaded...

  16. Comparison of Leaching Rates of Glass-Ceramic and Glass

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>With the increase of the burn-up of the nuclear fuel, the amounts of the long-lived radionuclides increase. The solubility of actinides such as plutonium in glass is very limited. Glass-ceramic as the new

  17. POROUS WALL, HOLLOW GLASS MICROSPHERES

    Energy Technology Data Exchange (ETDEWEB)

    Sexton, W.

    2012-06-30

    Hollow Glass Microspheres (HGM) is not a new technology. All one has to do is go to the internet and Google{trademark} HGM. Anyone can buy HGM and they have a wide variety of uses. HGM are usually between 1 to 100 microns in diameter, although their size can range from 100 nanometers to 5 millimeters in diameter. HGM are used as lightweight filler in composite materials such as syntactic foam and lightweight concrete. In 1968 a patent was issued to W. Beck of the 3M{trademark} Company for 'Glass Bubbles Prepared by Reheating Solid Glass Particles'. In 1983 P. Howell was issued a patent for 'Glass Bubbles of Increased Collapse Strength' and in 1988 H. Marshall was issued a patent for 'Glass Microbubbles'. Now Google{trademark}, Porous Wall, Hollow Glass Microspheres (PW-HGMs), the key words here are Porous Wall. Almost every article has its beginning with the research done at the Savannah River National Laboratory (SRNL). The Savannah River Site (SRS) where SRNL is located has a long and successful history of working with hydrogen and its isotopes for national security, energy, waste management and environmental remediation applications. This includes more than 30 years of experience developing, processing, and implementing special ceramics, including glasses for a variety of Department of Energy (DOE) missions. In the case of glasses, SRS and SRNL have been involved in both the science and engineering of vitreous or glass based systems. As a part of this glass experience and expertise, SRNL has developed a number of niches in the glass arena, one of which is the development of porous glass systems for a variety of applications. These porous glass systems include sol gel glasses, which include both xerogels and aerogels, as well as phase separated glass compositions, that can be subsequently treated to produce another unique type of porosity within the glass forms. The porous glasses can increase the surface area compared to &apos

  18. Foam-like scaffolds for bone tissue engineering based on a novel couple of silicate-phosphate specular glasses: synthesis and properties.

    Science.gov (United States)

    Vitale-Brovarone, Chiara; Baino, Francesco; Bretcanu, Oana; Verne, Enrica

    2009-11-01

    Glass-ceramic scaffolds mimicking the structure of cancellous bone were produced via sponge replication technique by using a polyurethane foam as template and glass powder below 30 lm as inorganic phase. Specifically, a SiO₂-based glass of complex composition and its corresponding P₂O₅-based "specular" glass were used as materials for scaffolding. The polymeric sponge was thermally removed and the glass powders were sintered to obtain a replica of the template structure. The scaffolds were investigated and compared from a structural, morphological and mechanical viewpoint by assessing their crystalline phases, volumetric shrinkage, pores content and interconnection, mechanical strength. In addition, the scaffolds were soaked in acellular simulated body fluid to investigate their in vitro behaviour. The produced scaffolds have a great potential for bone reconstructive surgery because their features, such as shape, strength, bioactivity and bioresorption, can be easily tailored according to the end use.

  19. INORGANIC PHOSPHORS IN GLASS BASED ON LEAD SILICATE GLASSES

    Directory of Open Access Journals (Sweden)

    V. A. Aseev

    2014-09-01

    Full Text Available We created and synthesized luminescent composite of the "phosphor in glass" type, based on the lead-silicate matrix and fine-dispersed powder of cerium-activated yttrium-aluminum garnet crystal. Lead-silicate system (40SiO2- 20PbO-(40-x PbF2-xAlF3, x = 0-25 was chosen as the glassy matrix. Initial glass was reduced to powder (frit for "phosphor in glass" composite with a particle size about 50 µm. Glass frit and powder of commercial YAG:Ce3+ phosphor were mixed in a ratio of 30 to 70 (wt %. Then this composite was pressed in a tablet and sintered on a quartz substrate at 823 К for 30 minutes. Thus, the plane parallel sheet for composite of the "phosphor in glass" was obtained with a diameter equal to 10 mm. For the purpose to reduce the loss of light in the presence of dispersion at a glass-phosphor boundary, optimization of glass mixture was done by adjusting the refractive index. X-ray phase and spectral-luminescent analysis of the derived composite were done. The results of these studies showed that there was no degradation of YAG: Ce powder during sintering. Dependence of luminescence intensity from temperature in the range from room temperature to 473 К was studied. It was shown, that with the phosphor in glass usage thermal quenching of luminescence was reduced in comparison with the silicone. The model of white LED was created with the "phosphor in glass" composite based on lead-silicate glasses with low temperature of vitrifying. The derived LED emits white light with a color temperature of 4370 K, and the luminous efficiency is equal to 58 lm/W. The developed luminescent composite based on the lead-silicate matrix can be used for the production of high-power white light LED.

  20. Methods of fiber surface grafting for interphase design and tailored composite response

    Science.gov (United States)

    Arnold, Jesse Judson

    1997-11-01

    The objective of this research was to develop methods of fiber surface grafting for interphase formation, and to experimentally evaluate and model these interphases in order to further elucidate their role in fiber-reinforced composites. Surface modification by sp{60}Co gamma irradiation was used initially to graft acrylic polymers on the surface of ultra-high modulus (UHMPE) fibers. This technique utilized low dose rates and low total doses, and achieved grafting with retention of the exceptional UHMPE properties. The surface properties of the fibers were evaluated using fourier transform infra-red spectroscopy (FTIR), electron spectroscopy for chemical analysis (ESCA), and mechanical tests and dynamic mechanical spectrometry (DMS) of discontinuous fiber composites. Depending on the glass transition temperature, Tg, and chemical structure of the graft, the fiber/matrix adhesion and the interfacial failure mechanism was tailored to provide either enhanced reinforcement or toughening. Using a three-phase block model, the DMS characteristics of the composites were modeled and the reinforcement efficiencies extrapolated as a function of surface treatment. The model successfully predicts the tan delta response of the composite and the appearance of additional loss dispersions associated with the interphase. However, the interactions between the high-energy gamma radiation and the fiber and grafts yield interphases that are difficult to characterize and control. The hydroperoxidation grafting method was subsequently developed, which permitted the grafting of tethered, linear chains by a free radical-type polymerization. Poly(styrene-stat-acrylonitrile) was grafted initially, in which the nitrogen in acrylonitrile was used as a marker to verify grafting and to estimate the grafting efficiency by ESCA analysis. Tapping modesp{TM} atomic force microscopy (TMAFM) images of the grafted fibers revealed a nodular surface topography with dimensions that were correlated to the

  1. Glasses in the D'Orbigny Angrite

    Science.gov (United States)

    Varela, M. E.; Kurat, G.; Brandstätter, F.; Bonnin-Mosbah, M.; Metrich, N.

    2001-03-01

    The D'Orbigny angrite contains abundant glasses, a phase which has not been previously reported from any other angrite. Glasses fill in part open druses and intersticial spaces between major silicates, or occur as glass inclusions in olivine.

  2. Holder for rotating glass body

    Science.gov (United States)

    Kolleck, Floyd W.

    1978-04-04

    A device is provided for holding and centering a rotating glass body such as a rod or tube. The device includes a tubular tip holder which may be held in a lathe chuck. The device can utilize a variety of centering tips each adapted for a particular configuration, such as a glass O-ring joint or semi-ball joint.

  3. OPAL Various Lead Glass Blocks

    CERN Multimedia

    These lead glass blocks were part of a CERN detector called OPAL (one of the four experiments at the LEP particle detector). OPAL uses some 12 000 blocks of glass like this to measure particle energies in the electromagnetic calorimeter. This detector measured the energy deposited when electrons and photons were slowed down and stopped.

  4. International Congress on Glass XII

    Energy Technology Data Exchange (ETDEWEB)

    Doremus, R H; LaCourse, W C; Mackenzie, J D; Varner, J R; Wolf, W W [eds.

    1980-01-01

    A total of 158 papers are included under nine headings: structure and glass formation; optical properties; electrical and magnetic properties; mechanical properties and relaxation; mass transport; chemical durability and surfaces; nucleation; crystallization; and glass ceramics; processing; and automatic controls. Separate abstracts were prepared for eight papers; four of the remaining papers had been processed previously for the data base. (DLC)

  5. Fullerene-doped porous glasses

    Science.gov (United States)

    Joshi, M. P.; Kukreja, L. M.; Rustagi, K. C.

    We report the doping of C60 in porous glass by diffusion in solution phase at room temperature. The presence of C60 in the doped porous glass was confirmed spectroscopically. We also report the changes in optical absorption spectrum and intensity-dependent transmission of 30 ns laser pulses at 527 nm in these materials.

  6. Fullerene-doped porous glasses

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, M.P. [Center for Adv. Technol., Indore (India). Nonlinear Optics Group; Kukreja, L.M. [Center for Adv. Technol., Indore (India). Nonlinear Optics Group; Rustagi, K.C. [Center for Adv. Technol., Indore (India). Nonlinear Optics Group

    1997-07-01

    We report the doping of C{sub 60} in porous glass by diffusion in solution phase at room temperature. The presence of C{sub 60} in the doped porous glass was confirmed spectroscopically. We also report the changes in optical absorption spectrum and intensity-dependent transmission of 30 ns laser pulses at 527 nm in these materials. (orig.)

  7. Tailor-made force fields for crystal-structure prediction.

    Science.gov (United States)

    Neumann, Marcus A

    2008-08-14

    A general procedure is presented to derive a complete set of force-field parameters for flexible molecules in the crystalline state on a case-by-case basis. The force-field parameters are fitted to the electrostatic potential as well as to accurate energies and forces generated by means of a hybrid method that combines solid-state density functional theory (DFT) calculations with an empirical van der Waals correction. All DFT calculations are carried out with the VASP program. The mathematical structure of the force field, the generation of reference data, the choice of the figure of merit, the optimization algorithm, and the parameter-refinement strategy are discussed in detail. The approach is applied to cyclohexane-1,4-dione, a small flexible ring. The tailor-made force field obtained for cyclohexane-1,4-dione is used to search for low-energy crystal packings in all 230 space groups with one molecule per asymmetric unit, and the most stable crystal structures are reoptimized in a second step with the hybrid method. The experimental crystal structure is found as the most stable predicted crystal structure both with the tailor-made force field and the hybrid method. The same methodology has also been applied successfully to the four compounds of the fourth CCDC blind test on crystal-structure prediction. For the five aforementioned compounds, the root-mean-square deviations between lattice energies calculated with the tailor-made force fields and the hybrid method range from 0.024 to 0.053 kcal/mol per atom around an average value of 0.034 kcal/mol per atom.

  8. Higher-order polarization singularitites in tailored vector beams

    Science.gov (United States)

    Otte, E.; Alpmann, C.; Denz, C.

    2016-07-01

    Higher-order polarization singularities embedded in tailored vector beams are introduced and experimentally realized. As holographic modulation allows to define order and location of any vectorial singularity, the surrounding vector field can be dynamically shaped. We demonstrate light fields associated with flowers or spider webs due to regular and even irregular patterns of the orientation of polarization ellipses. Beyond that, not yet investigated hybrid structures are introduced that allow generating networks of flowers and webs in very close vicinity. Our results pave the way to applications of singular optics in spatially extended, optimized optical tweezing and high-resolution imaging.

  9. Improving changeover time: a tailored SMED approach for welding cells

    OpenAIRE

    Guzmán, Ferradás P; Salonitis, Konstantinos

    2013-01-01

    Short changeover times have always been critical in manufacturing business. Set-up duration reduction initiatives have been associated with Shingós ‘Single Minute Exchange of Die' (SMED) method. Although a great number of companies have initiated SMED, some failed on implementation. The main reason is that strict application of Shingós SMED methodology is not the most efficient way to reduce set-up times in all situations. In the present study a tailored methodology is presented that has been...

  10. Tailored Optical Polarization in Nano-Structured Metamaterials

    CERN Document Server

    Mendoza, Bernardo S

    2016-01-01

    A very efficient method for the calculation of the effective optical response of nano-structured composite systems allows the design of metamaterials tailored for specific optical polarization properties. We use our method to design 2D periodic arrays of sub-wavelength dielectric inclusions within nanometric supported metallic thin films which behave as either an almost perfect linearly dichroic system, as a controllable source of circular polarized light, as a system with a large circular dichroism, or as a circular polarizer. All of these systems may be tuned over a wide energy range.

  11. Reducing phase singularities in speckle interferometry by coherence tailoring

    CERN Document Server

    Mantel, Klaus

    2016-01-01

    Speckle interferometry is an established optical metrology tool for the characterization of rough objects. The raw phase, however, is impaired by the presence of phase singularities, making the unwrapping procedure ambiguous. In a Michelson setup, we tailor the spatial coherence of the light source, achieving a physical averaging of independent, mutually incoherent speckle fields. In the resulting raw phase, the systematic phase is preserved while the number of phase singularities is greatly reduced. Both interferometer arms are affected by the averaging. The reduction is sufficient to even allow the use of a standard unwrapping algorithm originally developed for smooth surfaces only.

  12. Interactive Multimedia Tailored to Improve Diabetes Self-Management.

    Science.gov (United States)

    Wood, Felecia G; Alley, Elizabeth; Baer, Spencer; Johnson, Rebecca

    2015-09-01

    A pilot program was initiated to improve self-management of type 2 diabetes by rural adults. Using an iOS-based, individually tailored pre-/postintervention to improve diabetes self-management, undergraduate students developed a native mobile application to help participants effectively manage their diabetes. Brief quizzes assessed diabetes knowledge. A diabetes dictionary and physical activity assessment provided additional support to users of the app. On completion of the pilot, data analysis indicated increased diabetes knowledge and self-efficacy, and ease of use of the technology. Native app technology permits ready access to important information for those living with type 2 diabetes.

  13. Design and Implementation of Company Tailored Automated Material Handling

    DEFF Research Database (Denmark)

    Langer, Gilad; Bilberg, Arne

    1996-01-01

    This article focuses on the problems of analysing automation of material handling systems in order to develop an efficient automated solution that is specifically tailored to the company. The research has resulted in development of new methods for evaluating factory automation from design...... for their application with computer aided information processing tools. The framework is named the "Automated Material Handling (AMH) Preference GuideLine". The research has been carried out in close co-operation with Danish and European industry, where implementations of automation can be referred to. It is our...

  14. Tailoring spin-orbit torque in diluted magnetic semiconductors

    KAUST Repository

    Li, Hang

    2013-05-16

    We study the spin orbit torque arising from an intrinsic linear Dresselhaus spin-orbit coupling in a single layer III-V diluted magnetic semiconductor. We investigate the transport properties and spin torque using the linear response theory, and we report here: (1) a strong correlation exists between the angular dependence of the torque and the anisotropy of the Fermi surface; (2) the spin orbit torque depends nonlinearly on the exchange coupling. Our findings suggest the possibility to tailor the spin orbit torque magnitude and angular dependence by structural design.

  15. Design of an aeroelastically tailored 10 MW wind turbine rotor

    DEFF Research Database (Denmark)

    Zahle, Frederik; Tibaldi, Carlo; Pavese, Christian;

    2016-01-01

    This work presents an integrated multidisciplinary wind turbine optimization framework utilizing state-of-the-art aeroelastic and structural tools, capable of simultaneous design of the outer geometry and internal structure of the blade. The framework is utilized to design a 10 MW rotor constrained...... not to exceed the design loads of an existing reference wind turbine. The results show that through combined geometric tailoring of the internal structure and aerodynamic shape of the blade it is possible to achieve significant passive load alleviation that allows for a 9% longer blade with an increase in AEP...

  16. Optimal Path Planning for Mobile Robot Using Tailored Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Dong Xiao Xian

    2013-07-01

    Full Text Available During routine inspecting, mobile robot may be requested to visit multiple locations to execute special tasks occasionally. This study aims at optimal path planning for multiple goals visiting task based on tailored genetic algorithm. The proposed algorithm will generate an optimal path that has the least idle time, which is proven to be more effective on evaluating a path in our previous work. In proposed algorithm, customized chromosome representing a path and genetic operators including repair and cut are developed and implemented. Afterwards, simulations are carried out to verify the effectiveness and applicability. Finally, analysis of simulation results is conducted and future work is addressed.

  17. Microstructural gradients in thin hard coatings -- tailor-made

    DEFF Research Database (Denmark)

    Pantleon, Karen; Oettel, Heinrich

    1998-01-01

    ) alternating sputtering with and without substrate voltage and (c) pulsed bias voltage. On the basis of X-ray diffraction measurements, it is demonstrated that residual stress gradients and texture gradients can be designed tailor-made. Furthermore, results of microhardness measurements and scratch tests......Microstructural modifications resulting from time dependent variations of the bias voltage during the deposition of thin hard coatings are discussed. TiN-coatings are produced by reactive magnetron sputtering in several modes: (a) stepwise increase of the bias voltage during the deposition, (b...

  18. Database and Interim Glass Property Models for Hanford HLW Glasses

    Energy Technology Data Exchange (ETDEWEB)

    Hrma, Pavel R; Piepel, Gregory F; Vienna, John D; Cooley, Scott K; Kim, Dong-Sang; Russell, Renee L

    2001-07-24

    The purpose of this report is to provide a methodology for an increase in the efficiency and a decrease in the cost of vitrifying high-level waste (HLW) by optimizing HLW glass formulation. This methodology consists in collecting and generating a database of glass properties that determine HLW glass processability and acceptability and relating these properties to glass composition. The report explains how the property-composition models are developed, fitted to data, used for glass formulation optimization, and continuously updated in response to changes in HLW composition estimates and changes in glass processing technology. Further, the report reviews the glass property-composition literature data and presents their preliminary critical evaluation and screening. Finally the report provides interim property-composition models for melt viscosity, for liquidus temperature (with spinel and zircon primary crystalline phases), and for the product consistency test normalized releases of B, Na, and Li. Models were fitted to a subset of the screened database deemed most relevant for the current HLW composition region.

  19. Energetics of glass fragmentation: Experiments on synthetic and natural glasses

    Science.gov (United States)

    Kolzenburg, S.; Russell, J. K.; Kennedy, L. A.

    2013-11-01

    Natural silicate glasses are an essential component of many volcanic rock types including coherent and pyroclastic rocks; they span a wide range of compositions, occur in diverse environments, and form under a variety of pressure-temperature conditions. In subsurface volcanic environments (e.g., conduits and feeders), melts intersect the thermodynamically defined glass transition temperature to form glasses at elevated confining pressures and under differential stresses. We present a series of room temperature experiments designed to explore the fundamental mechanical and fragmentation behavior of natural (obsidian) and synthetic glasses (Pyrex™) under confining pressures of 0.1-100 MPa. In each experiment, glass cores are driven to brittle failure under compressive triaxial stress. Analysis of the load-displacement response curves is used to quantify the storage of energy in samples prior to failure, the (brittle) release of elastic energy at failure, and the residual energy stored in the post-failure material. We then establish a relationship between the energy density within the sample at failure and the grain-size distributions (D-values) of the experimental products. The relationship between D-values and energy density for compressive fragmentation is significantly different from relationships established by previous workers for decompressive fragmentation. Compressive fragmentation is found to have lower fragmentation efficiency than fragmentation through decompression (i.e., a smaller change in D-value with increasing energy density). We further show that the stress storage capacity of natural glasses can be enhanced (approaching synthetic glasses) through heat treatment.

  20. Glass science tutorial: Lecture No. 7, Waste glass technology for Hanford

    Energy Technology Data Exchange (ETDEWEB)

    Kruger, A.A.

    1995-07-01

    This paper presents the details of the waste glass tutorial session that was held to promote knowledge of waste glass technology and how this can be used at the Hanford Reservation. Topics discussed include: glass properties; statistical approach to glass development; processing properties of nuclear waste glass; glass composition and the effects of composition on durability; model comparisons of free energy of hydration; LLW glass structure; glass crystallization; amorphous phase separation; corrosion of refractories and electrodes in waste glass melters; and glass formulation for maximum waste loading.