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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. Direct conversion of halogen-containing wastes to borosilicate glass

    International Nuclear Information System (INIS)

    Glass has become a preferred waste form worldwide for radioactive wastes: however, there are limitations. Halogen-containing wastes can not be converted to glass because halogens form poor-quality waste glasses. Furthermore, halides in glass melters often form second phases that create operating problems. A new waste vitrification process, the Glass Material Oxidation and dissolution System (GMODS), removes these limitations by converting halogen-containing wastes into borosilicate glass and a secondary, clean, sodium-halide stream

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

    DEFF Research Database (Denmark)

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

    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...

  4. 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

  5. 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.

  6. 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.

  7. Utilization of borosilicate glass for transuranic waste immobilization

    International Nuclear Information System (INIS)

    Incinerated transuranic waste and other low-level residues have been successfully vitrified by mixing with boric acid and sodium carbonate and heating to 10500C in a bench-scale continuous melter. The resulting borosilicate glass demonstrates excellent mechanical durability and chemical stability

  8. Effect of zeolite formation on borosilicate glass dissolution kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Fournier, Maxime; Frugier, Pierre; Gin, Stephane [CEA, DEN-Marcoule, F30207, Bagnols-sur-Ceze (France)

    2013-07-01

    This study is a preliminary work on the description and the modeling of physico-chemical mechanisms potentially causing nuclear glass alteration to accelerate, as observed under experimental specific conditions. A better understanding of the mechanisms of alteration resumption, linked to the precipitation of zeolite, is necessary to model these phenomena. Leaching tests of a nuclear borosilicate glass show guidelines for designing experiments that promote alteration resumption and evidence the role of developed crystalline surfaces and aluminum on nucleation kinetics of zeolites. (authors)

  9. Thermophysical Properties of Multiphase Borosilicate Glass-Ceramic Waste Forms

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Andrew T. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Crum, Jarrod V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Tang, Ming [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rouxel, T. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-01-22

    Multiphase borosilicate glass-ceramics represent one candidate to contain radioactive nuclear waste separated from used nuclear fuel. In this work, the thermophysical properties from room temperature to 1273 K were investigated for four different borosilicate glass-ceramic compositions containing waste loadings from 42 to 60 wt% to determine the sensitivity of these properties to waste loading, as-fabricated microstructure, and potential evolutions in microstructure brought about by temperature transients. The thermal expansion, specific heat capacity, thermal diffusivity, and thermal conductivity are presented. The impact of increasing waste loading is shown to have a small but measurable effect on the thermophysical properties between the four compositions, contrasted to a much greater impact observed when transitioning from predominantly crystalline to amorphous systems. Thermal cycling below 1273 K was not found to measurably impact the thermophysical properties of the compositions investigated here.

  10. Moessbauer spectroscopic study of potassium borosilicate glasses at low temperatures

    International Nuclear Information System (INIS)

    The Moessbauer technique at the liquid nitrogen temperature (78 K) was applied to the estimation of nonbridging oxygens in FeO4, BO4, and SiO4 units in potassium borosilicate glasses. Moessbauer spectra consist of a quadrupole doublet and a hyperfine structure due to Fe3+ ions with tetrahedral symmetry. The hyperfine structure is attributed to a relaxation effect because magnetic susceptibility measurements revealed the glasses to be paramagnetic in the temperature range 78 - 295 K. A linear decrease in the absorption area and a similar decrease in the internal magnetic field for the hyperfine structure were observed with an increase in the alkali content of glasses. The decrease is ascribed to a formation of non-bridging oxygen at the site adjacent to iron, because the mean life-time of the internal magnetic field produced by 3d-electrons of iron is considered to decrease with increasing thermal vibration of the iron and neighboring oxygens. Fractions of non-bridging oxygens obtained from the reduction rate of the absorption area of hyperfine structure are in good agreement with earlier results for borate glasses with the same K2O/B2O3 ratios, in the alkali region of 8 - 20 mol% where the borosilicate glasses are essentially considered to be borate glasses diluted with SiO2. (author)

  11. Modeling and simulation of the cooling process of borosilicate glass

    International Nuclear Information System (INIS)

    For a better understanding of the thermomechanical behavior of glasses used for nuclear waste vitrification, the cooling process of a bulk borosilicate glass is modeled using the finite element code Abaqus. During this process, the thermal gradients may have an impact on the solidification process. To evaluate this impact, the simulation was based on thermal experimental data from an inactive nuclear waste package. The thermal calculations were made within a parametric window using different boundary conditions to evaluate the variations of temperature distributions for each case. The temperature differences throughout the thickness of solidified glass were found to be significantly non-uniform throughout the package. The temperature evolution in the bulk glass was highly responsive to the external cooling rates applied; thus emphasizing the role of the thermal inertia for this bulky glass cast. (authors)

  12. Leaching of borosilicate glasses incorporating H.L. radioactive wastes

    International Nuclear Information System (INIS)

    The european community commission organized in the period 1983-84 an international round robin test aiming at the evaluation of a method for controlling the high-temperature leaching resistance of borosilicate glasses incorporating high-level radioactive wastes. The radwaste experimental processes laboratory of the COMB/MEPIS Division, in collaboration with the Analytical Chemistry Laboratory of the TIB/CHI Division, partecipated to this round robin test with other 12 european and 2 extra european laboratories. In this paper the main results obtained in thi partecipation are reported

  13. Barium borosilicate glass as a matrix for the uptake of dyes

    International Nuclear Information System (INIS)

    Barium borosilicate (BBS) and sodium borosilicate (SBS) glass samples, prepared by the conventional melt-quench method, were used for the uptake of Rhodamine 6G dye from aqueous solution. The experimental conditions were optimized to get maximum uptake and was found to be 0.4 mg of dye per gram of BBS glass sample. For the same network former to modifier ratio, barium borosilicate glasses are found to have improved extent of uptake for the dye molecules from aqueous solutions compared to sodium borosilicate glasses. Based on 29Si MAS NMR studies on these glasses, it is inferred that significantly higher number of non-bridging oxygen atoms present in barium borosilicate glasses compared to sodium borosilicate glasses is responsible for its improved uptake of Rhodamine 6G dye. 11B MAS NMR studies have confirmed the simultaneous existence of boron in BO3 and BO4 configurations in both barium borosilicate and sodium borosilicate glasses. The luminescence studies have established that the dye molecule is incorporated into the glass matrix through ion exchange mechanism by replacing the exchangeable ions like Na+/Ba2+ attached with the non-bridging oxygen atoms present in the glass.

  14. Boron Speciation in Soda-Lime Borosilicate Glasses Containing Zirconium

    International Nuclear Information System (INIS)

    Boron speciation was investigated in soda-lime borosilicate glass containing zirconium. In such compositions, competition between charge compensators (here, sodium and calcium) can occur for the compensation of tetrahedral boron or octahedral zirconium units. 11B MAS NMR is particularly suitable for obtaining data on preferential compensation behavior that directly affects the boron coordination number. In addition to the classical proportions of tri- and tetrahedral boron, additional data can be obtained on the contributions involved in these two coordination numbers. An approach is described here based on simultaneous MAS spectrum analysis of borosilicate glass with variable Zr/Si and Ca/Na ratios at two magnetic field strengths (11. 7 and 18. 8 T), with constraints arising from MQMAS spectroscopy, detailed analysis of satellite transitions, and spin-echo experiments. New possibilities of 11B NMR were presented for improving the identification and quantification of the different contributions involved in tri- and tetrahedral boron coordination. Both NMR and Raman revealed a trend of decreased tetrahedral boron proportion with the increase of Ca/Na ratio or the Zr/Si ratio. This strongly suggests that zirconium compensation takes preference over boron compensation, and that zirconium and boron are both compensated mainly by sodium rather than calcium. (authors)

  15. 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.

  16. Enhancing cerium and plutonium solubility by reduction in borosilicate glass

    Science.gov (United States)

    Cachia, J.-N.; Deschanels, X.; Den Auwer, C.; Pinet, O.; Phalippou, J.; Hennig, C.; Scheinost, A.

    2006-06-01

    High-level radioactive wastes produced by spent fuel reprocessing containing fission and activation products as well as actinides are incorporated in a borosilicate glass. To ensure optimum radionuclide containment, the resulting glass must be as homogeneous as possible. Microscopic heterogeneity can arise from various processes including the excess loading of an element above its solubility limit. The current actinide loading limit is 0.4 wt%. Work is in progress to assess the actinide solubility in these glasses, especially for plutonium. Initially the actinides were simulated by lanthanides and hafnium. The results show that trivalent elements (La, Gd) exhibit greater solubility than tetravalent elements (Pu, Hf). Cerium is an interesting element because its oxidation state varies from IV to III depending on the process conditions, such as the temperature and redox potential of the melt. In order to quantify the solubility increase, cerium-doped glass samples were melted under reducing conditions by adding a reducing agent. The solubility observed at 1473 K increased significantly from 0.95 to 13.00 wt%. Several reducing compounds have been tested. This paper deals with this study and the application to reduce Pu(IV) to Pu(III). The reduction state was characterized by X-ray absorption spectroscopy (XANES) for plutonium and by chemical analysis for cerium. The material homogeneity was verified by optical and scanning electron microscopy. Preliminary findings concerning the reduction of Pu-doped glasses fabricated in hot cells are also discussed.

  17. Borosilicate glass as a matrix for the immobilization of Savannah River Plant waste

    International Nuclear Information System (INIS)

    The reference waste form for immobilization of Savannah River Plant (SRP) waste is borosilicate glass. In the reference process, waste is mixed with glass-forming chemicals and melted in a Joule-heated ceramic melter at 11500C. Waste glass made with actual or simulated waste on a small scale and glass made with simulated waste on a large scale confirm that the current reference process and glass-former composition are able to accommodate all SRP waste compositions and can produce a glass with: high waste loading; low leach rates; good thermal stability; high resistance to radiation effects; and good impact resistance. Borosilicate glass has been studied as a matrix for the immobilization of SRP waste since 1974. This paper reviews the results of extensive characterization and performance testing of the glass product. These results show that borosilicate glass is a very suitable matrix for the immobilization of SRP waste. 18 references, 3 figures, 10 tables

  18. 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.

  19. 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.

  20. The Effect of Sm2O3 on the Chemical Stability of Borosilicate Glass and Glass Ceramics

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yongqiang; WANG Mitang; LI Mei; WANG Ming; LIU Quansheng

    2014-01-01

    Sm2O3 containing zinc-borosilicate glass and glass ceramics were prepared by melt quenching method, and the effect of Sm2O3 and micro-crystallization on the chemical stability of borosilicate glass was explored. DTA analysis showed that the endothermic peak and exothermic peak of basic glass changed from 635℃and 834℃to 630℃and 828℃respectively as a result of the doping of Sm2O3. XRD analysis showed the promoting effect of Sm2O3 on crystallization ability of this glass. The cumulative mass loss of base glass, Sm2O3 containing glass, glass ceramic and Sm2O3 containing glass ceramic was 0.289, 0.253, 0.329, 0.269 mg/mm2 respectively after 26 days corrosion in alkali solution, and 1.293, 1.290, 0.999, 1.040 mg/mm2 respectively in acidic erosion medium. Micro-crystallization decreased and improved the alkali and acid resistance of borosilicate glass respectively, the addition of Sm2O3 increased the alkali resistance of base glass and glass ceramics, and the slight effect of Sm2O3 on the acid resistance of borosilicate glass was also observed.

  1. Removal of OH Absorption Bands Due to Pyrohydrolysis Reactions in Fluoride-Containing Borosilicate Glasses

    Science.gov (United States)

    Kobayashi, Keiji

    1997-05-01

    The purpose of this study is to decrease and to remove OH ions and H2O in borosilicate glasses. Fluoride-containing borosilicate glasses followed by dry-air-bubbling showed the significant decrease of OH absorption bands around 3500 cm-1. The decrease of OH absorption bands was elucidated by the use of pyrohydrolysis reactions in these glasses where fluoride ions react with OH ions or H2O during melting. The rates of the decrease of OH absorption bands substantially depend on high valence cations of fluorides. Particularly, the decrease rates of OH absorption coefficients were in the order of ZrF4-containing glass>AlF3-containing glass>ZnF2-containing glass. ZrF4-containing glass treated by dry-air-bubbling showed a good capability to remove OH absorption band. Fluoride-containing glasses showed the low flow point in comparison with fluoride-free glasses.

  2. 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

  3. LIQUIDUS TEMPERATURE OF HIGH-LEVEL WASTE BOROSILICATE GLASSES WITH SPINEL PRIMARY PHASE

    Science.gov (United States)

    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). T...

  4. 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.

  5. Monte Carlo Simulations of Coupled Diffusion and Surface Reactions during the Aqueous Corrosion of Borosilicate Glasses

    Energy Technology Data Exchange (ETDEWEB)

    Kerisit, Sebastien N.; Pierce, Eric M.; Ryan, Joseph V.

    2015-01-01

    Borosilicate nuclear waste glasses develop complex altered layers as a result of coupled processes such as hydrolysis of network species, condensation of Si species, and diffusion. However, diffusion has often been overlooked in Monte Carlo models of the aqueous corrosion of borosilicate glasses. Therefore, three different models for dissolved Si diffusion in the altered layer were implemented in a Monte Carlo model and evaluated for glasses in the compositional range (75-x) mol% SiO2 (12.5+x/2) mol% B2O3 and (12.5+x/2) mol% Na2O, where 0 ≤ x ≤ 20%, and corroded in static conditions at a surface-to-volume ratio of 1000 m-1. The three models considered instantaneous homogenization (M1), linear concentration gradients (M2), and concentration profiles determined by solving Fick’s 2nd law using a finite difference method (M3). Model M3 revealed that concentration profiles in the altered layer are not linear and show changes in shape and magnitude as corrosion progresses, unlike those assumed in model M2. Furthermore, model M3 showed that, for borosilicate glasses with a high forward dissolution rate compared to the diffusion rate, the gradual polymerization and densification of the altered layer is significantly delayed compared to models M1 and M2. Models M1 and M2 were found to be appropriate models only for glasses with high release rates such as simple borosilicate glasses with low ZrO2 content.

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

    International Nuclear Information System (INIS)

    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

  7. 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.

  8. 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.

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

    International Nuclear Information System (INIS)

    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

  10. Chemical durability of lead borosilicate glass matrix under simulated geological conditions

    International Nuclear Information System (INIS)

    The lead borosilicate glass has been developed for vitrification of High Level Waste (HLW) stored at Trombay. This waste is contains especially high contents of sodium, uranium sulphate and iron. The glasses containing HLW are to be ultimately disposed into deep geological repositories. Long term leach rates under simulated geological conditions need to be evaluated for glass matrix. Studies were taken up to estimate the lead borosilicate glass WTR-62 matrix for chemical durability in presence of synthetic ground water. The leachant selected was based on composition of ground water sample near proposed repository site. In the first phase of these tests, the experiments were conducted for short duration of one and half month. The leaching experiments were conducted in presence of a) distilled water b) synthetic ground water c) synthetic ground water containing granite, bentonite and ferric oxide and d) synthetic ground water containing humic acid at 1000C. The leachate samples were analysed by pHmetry , ion chromatography and UV -VIS spectrophotometry. The normalised leach rates for lead borosilicate WTR- 62 glass matrix based on silica, boron and sulphate analyses of leachates were of the order of 10-3 to 10-5 gms/cm2/day for 45 days test period in presence of synthetic ground water as well as in presence of other materials likely to be present along with synthetic ground water. These rates are comparable to those of sodium borsilicate glass matrices reported in literature. It is known that the leach rates of glass matrix decrease with longer test durations due to formation of leached layer on its surface. The observed leach rates of lead borosilicate WTR- 62 glass matrix for 45 day tests under simulated geological conditions were found to be sufficiently encouraging to take up long term tests for evaluating its performances under repository conditions. (author)

  11. 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

  12. Structural aspects of barium borosilicate glasses containing thorium and uranium oxides

    International Nuclear Information System (INIS)

    Barium borosilicate glasses incorporated with 15.86 wt% ThO2 and containing different amounts of uranium oxide were prepared by conventional melt quench method. Based on 29Si and 11B magic angle spinning nuclear magnetic resonance (MAS NMR) studies, it has been confirmed that uranium oxide incorporation is associated with distortion of borosilicate network as revealed by the increase in the relative concentration of Q2 structural units of silicon as well as the increase in the quadrupolar coupling constant (C q) of BO3 structural units. The increased number of non-bridging oxygen atoms brought about by the increase in Q2 structural units of silicon facilitates the incorporation of both uranium and thorium ions in the sites created by non-bridging oxygen atoms (network modifying positions) in the glass. Uranium oxide incorporation above 7.5 wt% resulted in the phase separation of ThO2 as revealed by the X-ray diffraction studies. The present study focuses on the structural changes with the borosilicate network of barium borosilicate glasses brought about by the introduction of thorium and uranium ions

  13. 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.

  14. Fabrication of Low Noise Borosilicate Glass Nanopores for Single Molecule Sensing

    Science.gov (United States)

    Bafna, Jayesh A.; Soni, Gautam V.

    2016-01-01

    We show low-cost fabrication and characterization of borosilicate glass nanopores for single molecule sensing. Nanopores with diameters of ~100 nm were fabricated in borosilicate glass capillaries using laser assisted glass puller. We further achieve controlled reduction and nanometer-size control in pore diameter by sculpting them under constant electron beam exposure. We successfully fabricate pore diameters down to 6 nm. We next show electrical characterization and low-noise behavior of these borosilicate nanopores and compare their taper geometries. We show, for the first time, a comprehensive characterization of glass nanopore conductance across six-orders of magnitude (1M-1μM) of salt conditions, highlighting the role of buffer conditions. Finally, we demonstrate single molecule sensing capabilities of these devices with real-time translocation experiments of individual λ-DNA molecules. We observe distinct current blockage signatures of linear as well as folded DNA molecules as they undergo voltage-driven translocation through the glass nanopores. We find increased signal to noise for single molecule detection for higher trans-nanopore driving voltages. We propose these nanopores will expand the realm of applications for nanopore platform. PMID:27285088

  15. 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...

  16. In-vitro bioactivity of zirconia doped borosilicate glasses

    International Nuclear Information System (INIS)

    Glass composition 31B2O3-20SiO2-24.5Na2O-(24.5-x) CaO-xZrO2 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

  17. A kinetic approach of sulphur behaviour in borosilicate glasses and melts: implications for sulphate incorporation in nuclear waste glasses

    Energy Technology Data Exchange (ETDEWEB)

    Lenoir, Marion [Service de Confinement des Dechets et Vitrification - Laboratoire d' Etudes de Base sur les Verres, CEA Valrho, Centre de Marcoule, 30207 Bagnols sur Ceze (France); Physique des Mineraux et des Magmas, UMR 7047 - CNRS, Institut de Physique du Globe de Paris, 7 place Jussieu, 75252 Paris Cedex 05 (France); Grandjean, Agnes [Service de Confinement des Dechets et Vitrification - Laboratoire d' Etudes de Base sur les Verres, CEA Valrho, Centre de Marcoule, 30207 Bagnols sur Ceze (France); Neuville, Daniel R. [Physique des Mineraux et des Magmas, UMR 7047 - CNRS, Institut de Physique du Globe de Paris, 7 place Jussieu, 75252 Paris Cedex 05 (France)

    2008-07-01

    The kinetics of sulphate decomposition in a borosilicate melt were studied using in situ Raman spectroscopy. This technique permits the quantification of the amount of sulphate dissolved in a borosilicate glass as a function of heating time by comparison with measurements obtained by microprobe WDS (Wavelength Dispersive Spectrometry). In order to quantify the content of sulphate obtained by Raman spectroscopy, the integrated intensity of the sulphate band at 985 cm{sup -1} was scaled to the sum of the integrated bands between 800 and 1200 cm{sup -1}, bands that are assigned to Q{sup n} silica units on the basis of previous literature. Viscosities of some borosilicate glasses are also presented here in order to study the kinetics of sulphate decomposition as a function of the viscosity of the melt. This underlines the importance of variations in viscosity depending on the composition of the melt and thus shows that viscosity is an important parameter governing the kinetics of decomposition of sulphate in borosilicate glasses. (authors)

  18. Process for the fabrication of hollow core solenoidal microcoils in borosilicate glass

    International Nuclear Information System (INIS)

    We report the fabrication of solenoidal microcoils with hollow core embedded within two 100 µm thick borosilicate glass wafers. The main process steps are the reactive ion etching of borosilicate glass, anodic wafer bonding, copper metal organic chemical vapor deposition (Cu MOCVD) and electroless galvanization. Our motivation stems from the need for a reliable, precise fabrication method of microcoils for high-resolution magnetic resonance imaging (MRI). For reduced loss at high-frequency operation, glass, with a lower dielectric constant as compared to silicon, was chosen as a substrate material. Simultaneously, this offers MRI sample observation owing to its optical transparency. Further essential parameters for the coil design were the need for small coil dimensions, a high filling factor (region of interest within the coil occupied by the sample/overall coil volume), and low-loss electrical connectability to external devices. In an attempt to achieve those requirements, the reported process demonstrates the combination of front- and backside borosilicate glass RIE of small dimensional features (down to 10 µm wall thickness) with subsequent conformal metallization of the 3D solenoidal coil by means of Cu MOCV and electroless galvanization

  19. The Coordination State of B and Al of Borosilicate Glass by IR Spectra

    Institute of Scientific and Technical Information of China (English)

    WAN Junpeng; CHENG Jinshu; LU Ping

    2008-01-01

    The IR spectra of R2O-RO-B2O3-SiO2 and R2O-RO-B2O3-Al2O3-SiO2 glasses were tested for the study of coordination state of B, Al and their content. The results show that no matter Na2O/B2O3>1,=1, or<1, both [Bo3] and destroyed Si-O bond exist in glass structure; the addition of Al2O3 to borosilicate glass reduced both the number of non-bridging oxygen in the silicate network and the number of [BO4] units.

  20. 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.

  1. 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 ...

  2. Profile Control of a Borosilicate-Glass Groove Formed by Deep Reactive Ion Etching

    CERN Document Server

    Akashi, T

    2008-01-01

    Deep reactive ion etching (DRIE) of borosilicate glass and profile control of an etched groove are reported. DRIE was carried out using an anodically bonded silicon wafer as an etching mask. We controlled the groove profile, namely improving its sidewall angle, by removing excessively thick polymer film produced by carbonfluoride etching gases during DRIE. Two fabrication processes were experimentally compared for effective removal of the film : DRIE with the addition of argon to the etching gases and a novel combined process in which DRIE and subsequent ultrasonic cleaning in DI water were alternately carried out. Both processes improved the sidewall angle, and it reached 85o independent of the mask-opening width. The results showed the processes can remove excessive polymer film on sidewalls. Accordingly, the processes are an effective way to control the groove profile of borosilicate glass.

  3. 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 <10 ppm (by mass), these Re results implied that the solubility should not be a limiting factor in processing radioactive wastes, assuming Tc as Tc(7+) and similarities between Re(7+) and Tc(7+) behavior in this glass system.

  4. 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.

  5. Modeling surface area to volume effects on borosilicate glass dissolution

    International Nuclear Information System (INIS)

    We simulated the reaction of SRL-131 glass with equilibrated J-13 water in order to investigate the effects of surface area to volume ratio (SA/V) on glass dissolution. We show that glass-fluid ion exchange causes solution pH to rise to progressively higher values as SA/V increases. Because the ion exchange is rapid relative to the duration of the glass dissolution experiment, the pH effect does not scale with (SA/V)*time. Experiments compared at the same (SA/V)*time value therefore have different pHs, with higher pHs at higher SA/V ratios. Both experimental data and our simulation results show similar trends of increasing reaction rate as a function of SA/V ratio when scaled to (SA/V)*time. Glasses which react in systems of differing SA/V ratio therefore follow different reaction paths and high SA/V ratios cannot be used to generate data which accurately scales to long time periods unless the ion exchange effect is taken into account. We suggest some simple test designs which enable more reliable high. SA/V accelerated tests

  6. Thermal and structural studies on barium borosilicate glasses containing sulphate ions

    International Nuclear Information System (INIS)

    Borosilicate glasses having composition SiO2)0.416(B2O3)0.208 (Na2O)0.218(BaO)0.157 containing up to 4 mol % sulphate ions were prepared by conventional melt-quench method. Incorporation of sulphate ions in the glass has been found to weaken the glass network as revealed by the decrease in the glass transition temperatures. Based on 29Si and 11B magic angle spinning nuclear magnetic resonance (MAS NMR) studies, it has been established that the silicate network undergoes slight depolymerisation while the boron structural units remained unaffected with sulphate addition in the glass. Above 4 mol % incorporation of sulphate ions resulted in the devitrification of the glass. (author)

  7. Characteristics of borosilicate glass media fabricated by melting HEPA filter media with inorganic additives

    International Nuclear Information System (INIS)

    HEPA filters are widely used in the nuclear fields as a final off-gas cleaning unit. To assess the applicability of vitrification technology either to treat used filter media or to produce borosilicate glass medium for the solidification of alpha-contaminated wastes, various waste glasses of different compositions were fabricated by melting mixture of HEPA filter media and inorganic additives. Physicochemical properties such as microhardness, density, thermal expansion, and short-term leaching behavior were characterized. XRD analysis showed that amorphous glasses were formed for a wide range of mixing ratio. Leach resistances, measured by PCT-B leach tests, were superior to that of EA (Environmental Assessment) glass. Other properties were similar to those of glass media used for the vitrification of high-level radioactive wastes in foreign countries

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

    DEFF Research Database (Denmark)

    Cheng, D.S.; Yang, G.; Zhao, Y.Q.;

    2015-01-01

    Transmission electron microscopy and related analytical techniques have been widely used to study the microstructure of different materials. However, few research works have been performed in the field of glasses, possibly due to the electron-beam irradiation damage. In this paper, we have...... 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...

  9. Water leaching of borosilicate glasses: experiments, modeling and Monte Carlo simulations

    International Nuclear Information System (INIS)

    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

  10. Aqueous corrosion of borosilicate glasses: experiments, modeling and Monte-Carlo simulations

    International Nuclear Information System (INIS)

    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

  11. Chemical compatibility of HLW borosilicate glasses with actinides

    International Nuclear Information System (INIS)

    During liquid storage of HLLW the formation of actinide enriched sludges is being expected. Also during melting of HLW glasses an increase of top-to-bottom actinide concentrations can take place. Both effects have been studied. Besides, the vitrification of plutonium enriched wastes from Pu fuel element fabrication plants has been investigated with respect to an isolated vitrification process or a combined one with the HLLW. It is shown that the solidification of actinides from HLLW and actinide waste concentrates will set no principal problems. The leaching of actinides has been measured in salt brine at 230C and 1150C. (orig.)

  12. A critical review of radiation effects on borosilicate glasses

    International Nuclear Information System (INIS)

    Most of the experimental values have been obtained by loading the glass with alpha emitters like Cm 244 and Pu 238. The data existing in literature on stored energy, and density variation are presented and discussed. Attention is given to the variation of the leaching rate due to the radiation effect. Samples loaded with alpha emitters have given data up to 0.17 dpa and such bombarded with heavy ions show large effects due to dose rate effects. A study on defect formation has shown that under electrons irradiation, formation of bubbles is possible. (DG)

  13. Basaltic glasses from Iceland and the deep sea: Natural analogues to borosilicate nuclear waste-form glass

    International Nuclear Information System (INIS)

    The report provides a detailed analysis of the alteration process and products for natural basaltic glasses. Information of specific applicability to the JSS project include: * The identification of typical alteration products which should be expected during the long-term corrosion process of low-silica glasses. The leached layers contain a relatively high proportion of crystalline phases, mostly in the form of smectite-type clays. Channels through the layer provide immediate access of solutions to the fresh glass/alteration layer interface. Thus, glasses are not 'protected' from further corrosion by the surface layer. * Corrosion proceeds with two rates - an initial rate in silica-undersaturated environments and a long-term rate in silica-saturated environments. This demonstrates that there is no unexpected change in corrosion rate over long periods of time. The long-term corrosion rate is consistent with that of borosilicate glasses. * Precipitation of silica-containing phases can result in increased alteration of the glass as manifested by greater alteration layer thicknesses. This emphasizes the importance of being able to predict which phases form during the reaction sequence. * For natural basaltic glasses the flow rate of water and surface area of exposed glass are critical parameters in minimizing glass alteration over long periods of time. The long-term stability of basalt glasses is enhanced when silica concentrations in solution are increased. In summary, there is considerable agreement between corrosion phenomena observed for borosilicate glasses in the laboratory and those observed for natural basalt glasses of great age. (With 121 refs.) (authors)

  14. Elastic properties investigation of gamma-radiated barium lead borosilicate glass using ultrasonic technique

    International Nuclear Information System (INIS)

    Highlights: → Change in acoustical parameter due to composition effect and irradiation effect. → Changes in the structure of the glass (BO3 → BO4) due to the effect of radiation. → Structural changes in the BO3 to BO4 have a more compactness structure. - Abstract: The ultrasonic velocities were measured in barium lead borosilicate glass samples of different compositions before and after irradiation with γ-rays. Measurements were carried out at room temperature and 4 MHz frequency using ultrasonic technique. The ultrasonic velocities data of glass samples have been used to find the elastic modulus and micro-hardness. Densities of glass samples were measured by Archimedes's principle using n-hexane as immersion liquid. It was found that ultrasonic velocity, elastic modulus and micro-hardness increase with increasing barium oxide content and increasing γ-radiation dose.

  15. 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

  16. Positive and Negative Mixed Glass Former Effects in Sodium Borosilicate and Borophosphate Glasses Studied by (23)Na NMR.

    Science.gov (United States)

    Storek, Michael; Adjei-Acheamfour, Mischa; Christensen, Randilynn; Martin, Steve W; Böhmer, Roland

    2016-05-19

    Glasses with varying compositions of constituent network formers but constant mobile ion content can display minima or maxima in their ion transport which are known as the negative or the positive mixed glass former effect, MGFE, respectively. Various nuclear magnetic resonance (NMR) techniques are used to probe the ion hopping dynamics via the (23)Na nucleus on the microscopic level, and the results are compared with those from conductivity spectroscopy, which are more sensitive to the macroscopic charge carrier mobility. In this way, the current work examines two series of sodium borosilicate and sodium borophosphate glasses that display positive and negative MGFEs, respectively, in the composition dependence of their Na(+) ion conductivities at intermediate compositions of boron oxide substitution for silicon oxide and phosphorus oxide, respectively. A coherent theoretical analysis is performed for these glasses which jointly captures the results from measurements of spin relaxation and central-transition line shapes. On this basis and including new information from (11)B magic-angle spinning NMR regarding the speciation in the sodium borosilicate glasses, a comparison is carried out with predictions from theoretical approaches, notably from the network unit trap model. This comparison yields detailed insights into how a variation of the boron oxide content and thus of either the population of silicon or phosphorus containing network-forming units with different charge-trapping capabilities leads to nonlinear changes of the microscopic transport properties. PMID:27092392

  17. 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.

  18. 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

  19. 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

  20. 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.

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

    International Nuclear Information System (INIS)

    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

  2. Corrosion testing of a plutonium-loaded lanthanide borosilicate glass made with Frit B

    International Nuclear Information System (INIS)

    Laboratory tests were conducted with a lanthanide borosilicate (LaBS) glass made with Frit B and added PuO2 (the glass is referred to herein as Pu LaBS-B glass) to measure the dependence of the glass dissolution rate on pH and temperature. These results are compared with the dependencies used in the Defense HLW Glass Degradation Model that was developed to account for HLW glasses in total system performance assessment (TSPA) calculations for the Yucca Mountain repository to determine if that model can also be used to represent the release of radionuclides from disposed Pu LaBS glass by using either the same parameter values that are used for HLW glasses or parameter values specific for Pu LaBS glass. Tests were conducted by immersing monolithic specimens of Pu LaBS-B glass in six solutions that imposed pH values between about pH 3.5 and pH 11, and then measuring the amounts of glass components released into solution. Tests were conducted at 40, 70, and 90 C for 1, 2, 3, 4, and 5 days at low glass-surface-area-to-solution volume ratios. As intended, these test conditions maintained sufficiently dilute solutions that the impacts of solution feedback effects on the dissolution rates were negligible in most tests. The glass dissolution rates were determined from the concentrations of Si and B measured in the test solutions. The dissolution rates determined from the releases of Si and B were consistent with the 'V' shaped pH dependence that is commonly seen for borosilicate glasses and is included in the Defense HLW Glass Degradation Model. The rate equation in that model (using the coefficients determined for HLW glasses) provides values that are higher than the Pu LaBS-B glass dissolution rates that were measured over the range of pH and temperature values that were studied (i.e., an upper bound). Separate coefficients for the rate expression in acidic and alkaline solutions were also determined from the test results to model Pu LaBS-B glass dissolution directly. The

  3. Barium borosilicate glass - a potential matrix for immobilization of sulfate bearing high-level radioactive liquid waste

    International Nuclear Information System (INIS)

    Borosilicate glass formulations adopted worldwide for immobilization of high-level radioactive liquid waste (HLW) is not suitable for sulphate bearing HLW, because of its low solubility in such glass. A suitable glass matrix based on barium borosilicate has been developed for immobilization of sulphate bearing HLW. Various compositions based on different glass formulations were made to examine compatibility with waste oxide with around 10 wt% sulfate content. The vitrified waste product obtained from barium borosilicate glass matrix was extensively evaluated for its characteristic properties like homogeneity, chemical durability, glass transition temperature, thermal conductivity, impact strength, etc. using appropriate techniques. Process parameters like melt viscosity and pour temperature were also determined. It is found that SB-44 glass composition (SiO2: 30.5 wt%, B2O3: 20.0 wt%, Na2O: 9.5 wt% and BaO: 19.0 wt%) can be safely loaded with 21 wt% waste oxide without any phase separation. The other product qualities of SB-44 waste glass are also found to be on a par with internationally adopted waste glass matrices. This formulation has been successfully implemented in plant scale

  4. Luminescence properties of Gd{sup 3+}-doped borosilicate scintillating glass

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Chunmei [Key Laboratory of Materials for High Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); Patent Examination Cooperation HuBei Center of The Patent Office, SIPO, Wuhan, HuBei 430070 (China); Graduate School of Chinese Academy of Sciences, Beijing 100039 (China); Liu, Shuang [Key Laboratory of Materials for High Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); Graduate School of Chinese Academy of Sciences, Beijing 100039 (China); Liu, Liwan [Shanghai University, Shanghai 201800 (China); Chen, Dan Ping, E-mail: dpchen2008@aliyun.com [Key Laboratory of Materials for High Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China)

    2015-04-15

    Gd{sup 3+}-doped borosilicate glasses are prepared in different melting atmosphere. Absorption spectra, decay time, luminescence spectra under UV and X-ray excitation are investigated. With melting atmosphere changing from air to CO, the luminescence intensities of Gd{sup 3+} at 313 nm under the excitation of UV and X-ray are both enhanced. This mainly results from the reduction of Gd{sup 3+}, which is validated by electron paramagnetic resonance (EPR). The optimal Gd{sub 2}O{sub 3} content for the glasses prepared under CO atmosphere is 7.5 mol%, whose integral scintillation efficiency is 20% compared with Bi{sub 4}Ge{sub 3}O{sub 12}. - Highlights: • Glasses with various Gd{sub 2}O{sub 3} contents are prepared in the air or CO atmosphere. • The glasses show stronger photoluminescence and radioluminescence intensity. • High integral scintillation efficiency obtained for the prepared glass is 20% of BGO.

  5. 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.

  6. Silver diffusion and coloration of soda lime and borosilicate glasses, Part 1: Effect on the transmission and coloration of stained glasses

    OpenAIRE

    ABDELLAH CHORFA; NABIL BELKHIR; FAUSTO RUBIO; JUAN RUBIO

    2012-01-01

    Using the conventional method of coloration, soda lime and borosilicate glasses have been painted. Once stained, these glasses were heat treated at temperatures close to their transition temperatures (Tg). A parametric study was carried out in order to determine at first the effect of the silver concentration in the stain spread on glass. In addition, it was studied the effect of the heat treatment duration and the chemical composition of the painted glasses on the formation and size of the s...

  7. X-Ray excited and photoluminescence of CdS1-xSex nanocrystals embedded in borosilicate glass matrix

    Directory of Open Access Journals (Sweden)

    Gomonnai A.V.

    2001-03-01

    Full Text Available The performed experimental studies of X-ray excited and photoluminescence, optical absorption and Raman scattering of CdS1-xSex nanocrystals, embedded in borosilicate glass matrix, have enabled the nanocrystal parameters (chemical composition, average radius, acceptor levels energy depth, electron-hole Coulomb interaction energy is to be determined.

  8. 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.

  9. Sol–gel synthesis and optical properties of CuGaS2 quantum dots embedded in sodium borosilicate glass

    International Nuclear Information System (INIS)

    Highlights: • The CuGaS2 quantum dots doped sodium borosilicate glass was prepared by sol–gel methods. • The obtained glass was investigated by XRD, (S)TEM and XPS. • Tetragonal crystalline phase of CuGaS2 quantum dots with spherical shape were formed uniformly in the glass matrix. • The third-order optical nonlinearity was investigated by Z-scan technique. - Abstract: I–III–VI2 ternary semiconductor CuGaS2 quantum dots embedded in sodium borosilicate glass matrix were synthesized by combining the sol–gel process and heat treatment in H2S gas. The structure and morphology of the obtained glass were studied by using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The results showed that tetragonal crystalline phase of CuGaS2 quantum dots with spherical shape were formed uniformly in the sodium borosilicate glass matrix, and the sizes ranged from 5 to 25 nm with an average particle size of 12.75 nm. The optical nonlinearity was studied using Z-scan technique employing 200 fs at the wavelength of 800 nm. The glass doped with CuGaS2 quantum dots exhibited large third-order optical nonlinear susceptibility χ(3) of 1.60 × 10−9 esu

  10. Optical properties of 3d transition metal ion-doped sodium borosilicate glass

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Hongli [School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, Guangdong (China); Tanner, Peter A., E-mail: peter.a.tanner@gmail.com [Department of Science and Environmental Studies, The Hong Kong Institute of Education, 10 Lo Ping Road, Tai Po, N.T., Hong Kong Special Administrative Region (Hong Kong)

    2015-03-15

    Graphical abstract: Photographs of undoped (SiO{sub 2}){sub 50} (Na{sub 2}O){sub 25} (B{sub 2}O{sub 3}){sub 25} (SiNaB) glass and transition metal ion-doped (TM){sub 0.5} (SiO{sub 2}){sub 49.5} (Na{sub 2}O){sub 25} (B{sub 2}O{sub 3}){sub 25} glass samples. - Highlights: • 3d transition metal ion (from Ti to Zn) doped SiO{sub 2}-Na{sub 2}O-B{sub 2}O{sub 3} glasses. • Optical properties of doped glasses investigated. • V(IV,V); Cr(III, VI); Mn(II,III); Fe(II,III); Co(II); Ni(II); Cu(II) by XANES, DRS. • Strong visible absorption but only vanadium ion gives strong emission in glass. - Abstract: SiO{sub 2}-Na{sub 2}O-B{sub 2}O{sub 3} glasses doped with 3d-transition metal species from Ti to Zn were prepared by the melting-quenching technique and their optical properties were investigated. The X-ray absorption near edge spectra of V, Cr, and Mn-doped glasses indicate that the oxidation states of V(IV, V), Cr(III, VI) and Mn(II, III) exist in the studied glasses. The oxidation states revealed from the diffuse reflectance spectra of the glasses are V(IV, V), Cr(III, VI), Mn(III), Fe(II, III), Co(II), Ni(II), and Cu(II). Most of the 3d transition element ions exhibit strong absorption in the visible spectral region in the glass. Under ultraviolet excitation, the undoped sodium borosilicate glass produces weak and broad emission, while doping of vanadium introduces strong and broad emission due to the V(V) charge transfer transition. Only weak emission is observed from Ti(IV), Mn(II), Fe(III) and Cu(II), partly resulting from the strong electron–phonon coupling of the 3d-electrons and the relatively high phonon energy of the studied glass host, with the former leading to dominant nonradiative relaxation based on multiphonon processes for most of the 3d excited states.

  11. Influence of bicarbonate ions and redox conditions on the surface composition of a leached borosilicate glass

    International Nuclear Information System (INIS)

    A serie of short leaching tests have been performed on a borosilicate glass (I117) up to a maximum of 40 days. The tests were performed in a closed system in oxic and anoxic conditions and in presence of bicarbonate ions. The bicarbonate ions do not influence the mass losses while the oxic condition gives rise to an higher mass losses. Surface analysis was performed on the surface layer for the elements uranium and iron. Uranium is always depleted at the surface of the samples. It appears that adsorption and diffusion in the layer play an important part in the uranium released. Iron on the contrary is enriched so that solubility of the formed species are responsible of its concentration

  12. 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)

  13. Investigation of local environment around rare earths (La and Eu) by fluorescence line narrowing during borosilicate glass alteration

    Energy Technology Data Exchange (ETDEWEB)

    Molières, Estelle [CEA – DEN-DTCD-LCV-SECM Laboratoire d' études du Comportement à Long Terme, 30207 Bagnols-sur-Cèze (France); Panczer, Gérard; Guyot, Yannick [Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon, 69622 Villeurbanne cedex (France); Jollivet, Patrick [CEA – DEN-DTCD-LCV-SECM Laboratoire d' études du Comportement à Long Terme, 30207 Bagnols-sur-Cèze (France); Majérus, Odile; Aschehoug, Patrick; Barboux, Philippe [Laboratoire de Chimie de la Matière Condensée de Paris, UMR-CNRS 7574, École Nationale Supérieure de Chimie de Paris (ENSCP Chimie-ParisTech), 11 rue Pierre et Marie Curie, 75231 Paris (France); Gin, Stéphane [CEA – DEN-DTCD-LCV-SECM Laboratoire d' études du Comportement à Long Terme, 30207 Bagnols-sur-Cèze (France); Angeli, Frédéric, E-mail: frederic.angeli@cea.fr [CEA – DEN-DTCD-LCV-SECM Laboratoire d' études du Comportement à Long Terme, 30207 Bagnols-sur-Cèze (France)

    2014-01-15

    The local environment of europium in soda-lime borosilicate glasses with a range of La{sub 2}O{sub 3} content was probed by continuous luminescence and Fluorescence Line Narrowing (FLN) to investigate the local environment of rare earth elements in pristine and leached glass. After aqueous leaching at 90 °C at pH 7 and 9.5, rare earths were fully retained and homogeneously distributed in the amorphous alteration layer (commonly called gel). Two separate silicate environments were observed in pristine and leached glasses regardless of the lanthanum content and the leaching conditions. A borate environment surrounding europium was not observed in pristine and leached glasses. During glass alteration, OH groups were located around the europium environment, which became more organized (higher symmetry) in the first coordination shell. -- Highlights: • No borate environment surrounding europium was detected in pristine borosilicate glasses. • Up to 12 mol% of REE2O3 in glass, local environment of europium does not significantly change. • Europium environment becomes more ordered and symmetric in gels than in pristine glasses. • Two distinct silicate sites were observed, as well in pristine glass as in gels (leached glasses). • In altered glasses, OH groups were located around europium.

  14. Structural and luminescent investigation of Eu3+ doped lead borosilicate glasses

    Science.gov (United States)

    Babu, M. Reddi; Rao, N. Madhusudhana; Babu, A. Mohan; Jaidass, N.; Moorthy, C. Krishna; Ramamoorthy, L.

    2016-05-01

    Lead borosilicate (LBS) glasses incorporated with europium (Eu3+) ions were synthesized using various chemical constituents. The structure of the glass matrix has been studied by experimental techniques such as X-ray diffraction (XRD), Fourier transform infrared (FTIR), optical absorption (OA) and photoluminescence (PL) spectroscopy. From the XRD spectrum, several crystalline phases of LBS glass host were identified. The FTIR spectrum of the LBS glass host was recorded to investigate the local structural and functional groups. Due to the different characteristic nature of the Eu3+ ion, the absorption bands were observed from the ground (7F0) and the first excited (7F1) states. Further, Judd-Ofelt theory has been applied to compute the intensity parameters (Ωλ, λ = 2, 4 and 6) from the absorption intensities of 7F0 → 5D2 and 7F0 → 5L6 transitions, respectively. Characteristic emission bands are observed at 578, 592, 613,653 and 701 nm corresponding to 5D0 → 7F0, 7F1, 7F2, 7F3 and 7F4 transitions, respectively. The radiative and laser characteristic parameters like stimulated emission cross-section (σe) and branching ratios (βR) of the 5D0 excited level are computed. From the magnitude of stimulated emission cross-section (σe) and branching ratios (βR) obtained for 5D0 → 7F2 transition revealed that, Eu3+: LBS glasses are suitable for good laser action in the visible region.

  15. Nanoindentation of the pristine and irradiated forms of a sodium borosilicate glass: Insights from molecular dynamics simulations

    Science.gov (United States)

    Kilymis, D. A.; Delaye, J.-M.; Ispas, S.

    2016-07-01

    We have carried out classical molecular dynamics simulations in order to get insight into the atomistic mechanisms of the deformation during nanoindentation of the pristine and irradiated forms of a sodium borosilicate glass. In terms of the glass hardness, we have found that the primary factor affecting the decrease of hardness after irradiation is depolymerization rather than free volume, and we argue that this is a general trend applicable to other borosilicate glasses with similar compositions. We have analyzed the changes of the short- and medium-range structures under deformation and found that the creation of oxygen triclusters is an important mechanism in order to describe the deformation of highly polymerized borosilicate glasses and is essential in the understanding of the folding of large rings under stress. We have equally found that the less polymerized glasses present a higher amount of relative densification, while the analysis of bond-breaking during the nanoindentation has showed that shear flow is more likely to appear around sodium atoms. The results provided in this study can be proven to be useful in the interpretation of experimental results.

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

    Directory of Open Access Journals (Sweden)

    Ashis Kumar Mandal

    2015-05-01

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

  17. 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.

  18. Dissolution of borosilicate glasses under repository conditions of pressure and temperature

    International Nuclear Information System (INIS)

    This paper described laboratory experimental work in progress in the UK to examine the mechanisms of fluid buffered interactions of materials at possible repository temperatures and pressures and aims at proposing limiting temperature values for a disposal facility from the geochemist's viewpoint. At present work is concentrated on reconnaissance experiments on dissolution rates of the vitrified waste form and the changes in near-field granite surface chemistry and fissure properties which will have a bearing on nuclide adsorption immediately after release. The major conclusions: in all of the experiments the fluid state remained as liquid since temperatures never exceeded 3740C, under these subcritical conditions pressure decreases dissolution rate; the ability to extrapolate dissolution rate from values of 1000C to about 2000C, together with the maintenance of physical integrity indicate that the glasses studied are likely to be stable and predictable in leach behavior to temperatures well in excess of those currently being considered for disposal; Glass 209 dissolves more slowly over a wide pressure and temperature spectrum than does glass 189, although the latter is easier to fabricate; dissolution rate decreases with increasing time. The principal conclusions of this study so far is that experimental application of realistic repository hydrothermal PT conditions indicate for the first time that current formulations of borosilicate glass would appear to provide for an adequate waste disposal medium which would maintain stability and predictable behavior over a wider pressure and temperature spectrum than previously realized, allowing sme latitude in both pre-disposal storage period and eventual loading at the time of disposal

  19. A kinetic model for borosilicate glass dissolution based on the dissolution affinity of a surface alteration layer

    International Nuclear Information System (INIS)

    A kinetic model for the dissolution of borosilicate glass is used to predict the dissolution rate of a nuclear waste glass. In the model, the glass dissolution rate is controlled by the rate of dissolution of an alkali-depleted amorphous surface (gel) layer. Our model predicts that all components concentrated in the surface layer, affect glass dissolution rates. The good agreement between predicted and observed elemental dissolution rates suggests that the dissolution rate of the gel layer limits the overall rate of glass dissolution. The model predicts that the long-term rate of glass dissolution will depend mainly on ion concentrations in solution, and therefore on the secondary phases which precipitate and control ion concentrations. 10 refs., 5 figs., 1 tab

  20. Preparation, characterization and standard molar enthalpy of formation of BaO containing sodium borosilicate glasses and its comparison with international standard glass

    International Nuclear Information System (INIS)

    High level radioactive liquid waste (HLW) generated during reprocessing of spent nuclear fuel is immobilized in sodium borosilicate (NBS) glasses. Addition of BaO in NBS glass helps to improve the solubility of ThO2 in glass matrix. The knowledge of thermodynamic stability of glasses used for immobilization of HLW is important in predicting their long term stability. Several BaO substituted NBS glass samples were prepared by melt-quench technique and characterized by XRD, DTA, MAS-NMR. The standard molar enthalpy of formation of BaO substituted NBS glasses and the International Standard Glass (ISG) were determined. This work is done with an understanding that even though the above glass matrices are metastable in nature and meaningful measurement of equilibrium thermodynamic data is difficult; the information on relative thermodynamic stability data of NBS glasses with varying compositions prepared exactly in similar fashion will be helpful in deciding the most stable matrix for nuclear waste disposal

  1. Glass transition and crystallization kinetics of a barium borosilicate glass by a non-isothermal method

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Andreia A. S.; Soares, Roque S.; Lima, Maria M. A.; Monteiro, Regina C. C., E-mail: rcm@fct.unl.pt [Department of Materials Science, CENIMAT/I3N, Faculty of Sciences and Technology, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal)

    2014-01-28

    The glass transition and crystallization kinetics of a glass with a molar composition 60BaO-30B{sub 2}O{sub 3}-10SiO{sub 2} were investigated by differential scanning calorimetry (DSC) under non-isothermal conditions. DSC curves exhibited an endothermic peak associated with the glass transition and two partially overlapped exothermic peaks associated with the crystallization of the glass. The dependence of the glass transition temperature (T{sub g}) and of the maximum crystallization temperature (T{sub p}) on the heating rate was used to determine the activation energy associated with the glass transition (E{sub g}), the activation energy for crystallization (E{sub c}), and the Avrami exponent (n). X-ray diffraction (XRD) revealed that barium borate (β-BaB{sub 2}O{sub 4}) was the first crystalline phase to be formed followed by the formation of barium silicate (Ba{sub 5}Si{sub 8}O{sub 21}). The variations of activation energy for crystallization and of Avrami exponent with the fraction of crystallization (χ) were also examined. When the crystallization fraction (χ) increased from 0.1 to 0.9, the value of local activation energy (E{sub c}(χ)) decreased from 554 to 458 kJ/mol for the first exothermic peak and from 1104 to 831 kJ/mol for the second exothermic peak. The value determined for the Avrami exponent was near 2 indicating a similar one-dimensional crystallization mechanism for both crystalline phases. This was confirmed by the morphological studies performed by scanning electron microscopy (SEM) on glass samples heat-treated at the first and at the second crystallization temperatures.

  2. 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.

  3. 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.

  4. 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...

  5. Synthesis, characterization, and third-order nonlinear optical properties of copper quantum dots embedded in sodium borosilicate glass

    International Nuclear Information System (INIS)

    Highlights: ► The sodium borosilicate glass doped Cu quantum dots have been prepared by sol–gel route. ► The crystal structure and composition of as-prepared glass were investigated by XRD and XPS. ► Size and distribution of indium nanocrystals was determined by TEM and STEM. ► The third-order optical nonlinearity was investigated by using Z-scan technique. - Abstract: Copper quantum dots embedded in sodium borosilicate glass matrix were fabricated and analyzed in terms of their structural, chemical, and optical properties. X-ray powder diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses revealed that copper quantum dots were in face-centered-cubic crystalline phase and in the metallic state. Size and distribution of the quantum dots were measured by transmission electron microscopy (TEM) as well as high-resolution transmission electron microscopy (HRTEM). The results showed spherical shape have formed uniformly in the glass, and the size of these quantum dots were range from 1.5 to 5 nm with the average particle size about 2.7 nm. The third-order nonlinear optical properties of copper quantum dots doped glass were investigated by using Z-scan technique at the wavelength of 800 nm with femtosecond Ti: sapphire laser radiation. The value of third-order optical nonlinear susceptibility χ(3) of the glass was estimated to be 2.41 × 10−11 esu.

  6. 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.

  7. Release of boron and cesium or uranium from simulated borosilicate waste glasses through a compacted Ca-bentonite layer

    Science.gov (United States)

    Chun, K. S.; Kim, S. S.; Kang, C. H.

    2001-09-01

    The long-term release behavior of some elements from simulated borosilicate waste glasses (S-, K- and A-glass) in contact with a domestic compacted Ca-bentonite block and synthetic granitic groundwater at 80°C under argon atmosphere has been studied by dynamic leach tests since 1997 at KAERI. S- and K-glass differ mainly in their aluminum content, and A-glass contains 19.35 wt% UO 2 instead of fission product elements. Up to the present, the mass loss is almost the same as the normalized boron loss. This means that boron is an indicator on the dissolution of borosilicate waste glass. The leach rates of boron from K- and S-glasses after 861 days were approximately 3.1×10 -2 and 3.0×10 -2 g/ m2 day, respectively. However, the release rates of cesium through the bentonite block from K- and S-glasses were about 1/10th of the release rate of boron, which were almost the same around 2.5×10 -3 g/ m2 day. This may be due to their adsorption on the bentonite. The leach rate of boron from the A-glass was about 5.4×10 -2, but the leach rate of uranium from the A-glass specimen was quite low, below 4×10 -7 g/ m2 day. The low concentration of uranium in the leachates suggests that it hardly moves in a compacted bentonite block. By the EPMA, a yellowish uranium compound was deposited on the surface of the bentonite in contact with the A-glass specimen. The species of this phase should be identified to understand the release mechanism of uranium.

  8. Effects of magnesium minerals representative of the Callovian-Oxfordian clay-stone on borosilicate glass alteration

    International Nuclear Information System (INIS)

    Borosilicate glasses dissolution has been studied in presence of magnesium minerals. Those minerals (dolomite, illite, smectite...) belong to the Callovo-Oxfordian (COx) clay-stone layer, studied in France as a potential site for nuclear waste disposal. Such minerals contain magnesium, an element able to sustain glass alteration when it is available in solution. In the confined media of the wastes disposal, the solids reactivity controls the solution composition and can be the driving force of nuclear glass alteration. Experiments show that magnesium carbonates (hydro-magnesite and dolomite) increase in the glass alteration: the precipitation of magnesium silicates consumes silicon which slows down the formation of the glass passivating layer. The lower the magnesium mineral solubility, the lower the glass alteration. The purified clay phases (illite, smectite...) from the COx layer increase the glass alteration. Half the magnesium was replaced by sodium during the purification process. In such conditions, the effect of clay phases on glass alteration is in part due to the acidic pH-buffering effect of the clay fraction. The GRAAL model implemented in the geochemical transport code HYTEC has confirmed and quantified the mechanisms put in evidence in the experiments. Cells diffusion experiments where the two solids were separated by an inert diffusion barrier allow to valid reactive transport modelling. Such experiments are more representative of the glass package which will be separated from the COx by corrosion products. They show that glass alteration rate is reduced when solids are not close. (author)

  9. Visible to deep ultraviolet range optical absorption of electron irradiated borosilicate glass

    Science.gov (United States)

    Wang, Tie-Shan; Duan, Bing-Huang; Tian, Feng; Peng, Hai-Bo; Chen, Liang; Zhang, Li-Min; Yuan, Wei

    2015-07-01

    To study the room-temperature stable defects induced by electron irradiation, commercial borosilicate glasses were irradiated by 1.2 MeV electrons and then ultraviolet (UV) optical absorption (OA) spectra were measured. Two characteristic bands were revealed before irradiation, and they were attributed to silicon dangling bond (E’-center) and Fe3+ species, respectively. The existence of Fe3+ was confirmed by electron paramagnetic resonance (EPR) measurements. After irradiation, the absorption spectra revealed irradiation-induced changes, while the content of E’-center did not change in the deep ultraviolet (DUV) region. The slightly reduced OA spectra at 4.9 eV was supposed to transform Fe3+ species to Fe2+ species and this transformation leads to the appearance of 4.3 eV OA band. By calculating intensity variation, the transformation of Fe was estimated to be about 5% and the optical absorption cross section of Fe2+ species is calculated to be 2.2 times larger than that of Fe3+ species. Peroxy linkage (POL, ≡Si-O-O-Si≡), which results in a 3.7 eV OA band, is speculated not to be from Si-O bond break but from Si-O-B bond, Si-O-Al bond, or Si-O-Na bond break. The co-presence defect with POL is probably responsible for 2.9-eV OA band. Project supported by the Fundamental Research Funds for the Central Universities of China (Grant No. lzujbky-2014-16).

  10. Structure, thermal stability and resistance under external irradiation of rare earths and molybdenum-rich alumino-borosilicate glasses

    International Nuclear Information System (INIS)

    In France, the highly radioactive nuclear liquid wastes arising from spent nuclear fuel reprocessing (fission products + minor actinides (FPA)) are currently immobilized in an alumino-borosilicate glass called 'R7T7'. In the future, the opportunity of using new alumino-borosilicate glass compositions (HTC glasses) is considered in order to increase the waste loading in glasses and thus significantly decrease the number of glass canisters. However, the increase of the concentration of FPA could lead to the crystallization of rare-earth-rich phases (Ca2RE8(SiO4)6O2) or molybdenum-rich phases (CaMoO4, Na2MoO4) during melt cooling, which can modify the confinement properties of the glass (chemical durability, self-irradiation resistance..), particularly if they can incorporate radionuclides α or β in their structure. This thesis can be divided into two parts: The first part deals with studying the relationship that can occur between the composition, the structure and the crystallization tendency of simplified seven oxides glasses, belonging to the SiO2-B2O3-Al2O3-Na2O-CaO-MoO3-Nd2O3 system and derived from the composition of the HTC glass at 22,5 wt. % in FPA. The impact of the presence of platinoid elements (RuO2 in our case) on the crystallization of the different phases is also studied. The second part deals with the effect of actinides α decays and more particularly of nuclear interactions essentially coming from recoil nuclei (simulated here by heavy ions external irradiations) on the behaviour under irradiation of an alumino-borosilicate glass containing apatite Ca2Nd8(SiO4)6O2 crystals, that can incorporate actinides in their structure. Two samples containing apatite crystals with different size are studied, in order to understand the impact of microstructure on the irradiation resistance of this kind of material. (author)

  11. Impact of soda-lime borosilicate glass composition on water penetration and water structure at the first time of alteration

    International Nuclear Information System (INIS)

    In this study, the impact of soda-lime borosilicate glass composition and particularly the effect of charge compensators such Ca and Na and, of network formers such Si and Zr, on water penetration and water structure at the first time of alteration were investigated. Two non-destructive techniques were combined: the Fourier transform infrared spectroscopy in attenuated total reflection geometry to precise the predominant alteration mechanisms and assess the water structure in altered zone and the grazing incidence X-ray reflectometry to determine the thickness of the altered glass zone allowing to calculate the water diffusion coefficients through the glasses. The results of glass alteration at pH = 3 and 30 degrees C have shown that hydrolysis was the predominant mechanism after few seconds for glass having a high amount of non-binding oxygen. For the other glasses, which for the diffusion was the limiting reaction, the calculated water diffusion coefficients were comprised between 10-21 and 10-19 m2.s-1 and vary as a function of glass composition. An activation energy of 76.9 kJ.mol-1 was calculated and appears to be higher than inert gas diffusion through the glass highlighting that water molecules strongly interact with the glass matrix. (authors)

  12. High thermal neutron flux effects on structural and macroscopic properties of alkali-borosilicate glasses used as neutron guide substrate

    Science.gov (United States)

    Boffy, R.; Peuget, S.; Schweins, R.; Beaucour, J.; Bermejo, F. J.

    2016-05-01

    The behaviour of four alkali-borosilicate glasses under homogeneous thermal neutron irradiation has been studied. These materials are used for the manufacturing of neutron guides which are installed in most facilities as devices to transport neutrons from intense sources such as nuclear reactors or spallation sources up to scientific instruments. Several experimental techniques such as Raman, NMR, SANS and STEM have been employed in order to understand the rather different macroscopic behaviour under irradiation of materials that belong to a same glass family. The results have shown that the remarkable glass shrinking observed for neutron doses below 0.5 ·1018 n/cm2 critically depends upon the presence of domains where silicate and borate network do not mix.

  13. Mechanical and structural studies on sodium borosilicate glasses doped with Er2O3 using ultrasonic velocity and FTIR spectroscopy

    International Nuclear Information System (INIS)

    Sodium borosilicate glasses doped with different mol% content of Er2O3 have been prepared by rapid-quenching method. Ultrasonic velocities (both longitudinal and shear) measurements have been carried out at room temperature and at ultrasonic frequency of 4 MHz. Elastic moduli, Debye temperature, softening temperature, and Poisson's ratio have been obtained as a function of Er2O3 modifier content. Results show that the above-mentioned parameters have very slight change with the change of Er2O3 mol% content. Based on FTIR spectroscopy and theoretical (bond compression) model, quantitative analysis has been carried out in order to obtain more information about the structure of these glasses. The study indicated that the structure of these glasses is mainly composed of SiO4 units with four bridging oxygens (Q4), and with three bridging and one nonbridging oxygens (Q3)

  14. Comparative transportation risk assessment for borosilicate-glass and ceramic forms for immobilization of SRP Defense waste

    International Nuclear Information System (INIS)

    It is currently planned to immobilize the SRP high-level nuclear waste in solid form and then ship it from SRP to a federal repository. This report compared transportation operations and risks for SRP high-level waste in a borosilicate glass form and in a ceramic form. Radiological and nonradiological impacts from normal transport and from potential accidents during transit were determined using the Defense Waste Process Facility Environmental Impact Statement (DWPF EIS) as the source of basic data. Applicable regulations and some current regulatory uncertainties are also discussed

  15. 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.

  16. A comparative study by Molecular Dynamics of the ballistic effects and the thermal quenching effects in a sodium borosilicate glass

    International Nuclear Information System (INIS)

    The understanding of the aging under irradiation of nuclear glasses requires to study the induced changes at the atomic scale. A sodium borosilicate glass has been modeled by molecular dynamics and then submitted to low energies (4 keV) cascades series. Between each cascade, the structural evolutions have been analyzed and have shown a linear correlation between the glass swelling and its polymerization degree. The deep analysis of the different units constituting the glass shows that the lattice depolymerization instigated by the damage is mainly induced by the BO4 units conversion to BO3 and by the increase of the non bridging oxygen number. On account of the established structural changes, a comparison of the structural effects induced by irradiation to those generated by thermal quenching has been carried out. For that, the same glass has been prepared with various quench velocities (5*1012 and 1014 k.s-1) and the different structures obtained have been analyzed. It has been shown an increase of the BO3 units to the detriment of the BO4 units when the quench velocity increases, as well the non-bridging oxygen number. Thus qualitatively, the irradiation effects lead to structural consequences equivalent to those induced by thermal quenching effects. (O.M.)

  17. Calcium-borosilicate glass-ceramics wasteforms to immobilize rare-earth oxide wastes from pyro-processing

    Science.gov (United States)

    Kim, Miae; Heo, Jong

    2015-12-01

    Glass-ceramics containing calcium neodymium(cerium) oxide silicate [Ca2Nd8-xCex(SiO4)6O2] crystals were fabricated for the immobilization of radioactive wastes that contain large portions of rare-earth ions. Controlled crystallization of alkali borosilicate glasses by heating at T ≥ 750 °C for 3 h formed hexagonal Ca-silicate crystals. Maximum lanthanide oxide waste loading was >26.8 wt.%. Ce and Nd ions were highly partitioned inside Ca-silicate crystals compared to the glass matrix; the rare-earth wastes are efficiently immobilized inside the crystalline phases. The concentrations of Ce and Nd ions released in a material characterization center-type 1 test were below the detection limit (0.1 ppb) of inductively coupled plasma mass spectroscopy. Normalized release values performed by a product consistency test were 2.64·10-6 g m-2 for Ce ion and 2.19·10-6 g m-2 for Nd ion. Results suggest that glass-ceramics containing calcium neodymium(cerium) silicate crystals are good candidate wasteforms for immobilization of lanthanide wastes generated by pyro-processing.

  18. Irradiations effects on the structure of boro-silicated glasses: long term behaviour of nuclear waste glassy matrices

    International Nuclear Information System (INIS)

    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 (Eu3+ and Nd3+). 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 2,3.1013 at.cm-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)

  19. Incorporation of Fines and Noble Metals into HLW Borosilicate Glass: Industrial Responses to a Challenging Issue - 13056

    Energy Technology Data Exchange (ETDEWEB)

    Chauvin, E.; Chouard, N.; Prod' homme, A. [AREVA, AREVA NC, Paris (France); Boudot, E. [AREVA, AREVA NC, La Hague (France); Gruber, Ph.; Pinet, O. [CEA Marcoule LCV, France (France); Grosman, R. [AREVA, SGN, Paris (France)

    2013-07-01

    During the early stages of spent fuel reprocessing, the fuel rods are cut and dissolved to separate the solid metallic parts of the rods (cladding and end pieces) from the radioactive nitric acid solution containing uranium, plutonium, minor actinides and fission products (FP). This solution contains small, solid particles produced during the shearing process. These small particles, known as 'fines', are then separated from the liquid by centrifugation. At the La Hague plant in France, the fines solution is transferred to the vitrification facilities to be incorporated into borosilicate glass along with the highly radioactive FP solution. These fines are also composed of Zr, Mo and other noble metals (i.e. Ru, Pd, Rh, etc.) that are added before vitrification to the the FP solution that already contained noble metals. As noble metals has the potential to modify the glass properties (including viscosity, electrical conductivity, etc.) and to be affected by sedimentation inside the melter, their behavior in borosilicate glass has been studied in depth over the years by the AREVA and CEA teams which are now working together in the Joint Vitrification Laboratory (LCV). At La Hague, the R7 vitrification facility started operation in 1989 using induction-heated metallic melter technology and was quickly followed by the T7 vitrification facility in 1992. Incorporating the fines into glass has been a challenge since operation began, and has given rise to several R and D studies resulting in a number of technological enhancements to improve the mixing capability of the melters (multiple bubbling technology and mechanical stirring in the mid-90's). Nowadays, the incorporation of fines into R7T7 glass is well understood and process adaptations are deployed in the La Hague facilities to increase the operating flexibility of the melters. The paper will briefly describe the fines production mechanisms, give details of the resulting fines characteristics, explain

  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. Silver diffusion and coloration of soda lime and borosilicate glasses, Part 1: Effect on the transmission and coloration of stained glasses

    Directory of Open Access Journals (Sweden)

    ABDELLAH CHORFA

    2012-03-01

    Full Text Available Using the conventional method of coloration, soda lime and borosilicate glasses have been painted. Once stained, these glasses were heat treated at temperatures close to their transition temperatures (Tg. A parametric study was carried out in order to determine at first the effect of the silver concentration in the stain spread on glass. In addition, it was studied the effect of the heat treatment duration and the chemical composition of the painted glasses on the formation and size of the silver nanoparticles, the silver diffusion depth and also the glasses coloration. The characterization was made using UV-Vis spectroscopy, Raman confocal spectroscopy, SEM, EDX Technique and Abbe Refractometer. The obtained results shows that the coloration intensity of both glass types painted by the conventional method differs and depends essentially on the proportion of alkali ions in the glass. Moreover, it was found that the effect of the silver concentration in the stain is primordial and the heat treatment duration has a limited effect.

  2. The geochemical interactions of simulated borosilicate waste glass, granite and water at 100-3500C and 50MPa

    International Nuclear Information System (INIS)

    Four interactions experiments involving a simulated borosilicate waste glass, granite and deionised water have been carried out at 1000, 1500, 2000 and 3500C at a total pressure of 50 MPa to simulate the near-field geochemistry of a high level waste repository in granite. Experiments were conducted in gold-titanium cell, direct sampling autoclaves for run durations of 200 days (1000, 1500 and 2000C) and 30 days (3500C), during which time solution samples were extracted for the analysis of 25 chemical species. Solid phases retrieved at the end of the experiments were examined using X-ray diffraction and scanning electron microscopy. The high temperature speciation characteristics and degrees of mineral saturation of the fluids were investigated using the geochemical software packages, EQ3 and SOLMNEQ. (author)

  3. 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).

  4. Interaction of borosilicate glass and granodiorite at 1000C, 50 MPa: implications for models of radionuclide release

    International Nuclear Information System (INIS)

    The interaction of a simulated borosilicate waste glass, granodiorite and deionized water at 1000C, 50 MPa under closed system experimental conditions has revealed the rapid achievement of steady-state fluid concentrations for many chemical components of interest, (e.g., SiO2, La) and their rates of release from the near-field would be most appropriately modelled by a function of solubility and groundwater flow-rate. The conversion of these solubilities into conventional leach-rates has shown over five orders of magnitude range in relative release rates and emphasizes the need for source-term models to consider each radionuclide separately in terms of mechanisms of release

  5. Rhenium Solubility In Borosilicate Nuclear Waste Glass Implications For The Processing And Immobilization Of Technetium-99 (And Supporting Information With Graphical Abstract)

    International Nuclear Information System (INIS)

    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 ∼ 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 ∼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.

  6. 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.

  7. Study of phase separation and crystallization phenomena in soda-lime borosilicate glass enriched in MoO3

    International Nuclear Information System (INIS)

    Molybdenum oxide immobilization (MoO3, as fission product) is one of the major challenges in the nuclear glass formulation issues for high level waste solutions conditioning since many years, these solutions arising from spent nuclear fuel reprocessing. Phase separation and crystallisation processes may arise in molten glass when the MoO3 content is higher than its solubility limit that may depend on glass composition. Molybdenum combined with other elements such as alkali and alkaline-earth may form crystalline molybdates, known as 'yellow phases' in nuclear glasses which may decrease the glass durability. In order to confine high level wastes (HLW) such as the fission product solutions arising from the reprocessing of high burn-up UOX-type nuclear spent fuels, a new glass composition (HLW glass) is being optimized. This work is devoted to the study of the origin and the mechanism of phase separation and crystallization phenomena induced by molybdenum oxide incorporation in the HLW glass. From microstructural and structural point of view, the molybdenum oxide behavior was studied in glass compositions belonging to the SiO2-B2O3- Na2O-CaO simplified system which constituted basis for the HLW glass formulation. The structural role of molybdenum oxide in borosilicate network explaining the phase separation and crystallization tendency was studied through the coupling of structural (95Mo, 29Si, 11B, 23Na MAS NMR, XRD) and microstructural (SEM, HRTEM) analysis techniques. The determination of phase separation (critical temperature) and crystallization (liquidus temperature) appearance temperatures by in situ viscosimetry and Raman spectroscopy experiments allowed us to propose a transformation scenario during melt cooling. These processes and the nature of the crystalline phases formed (CaMoO4, Na2MoO4) that depend on the evolution of MoO3, CaO and B2O3 contents were correlated with changes of sodium and calcium cations proportions in the environment of molybdate

  8. First investigations of the influence of IVB elements (Ti, Zr, and Hf) on the chemical durability of soda-lime borosilicate glasses

    International Nuclear Information System (INIS)

    The influence of IVB elements (Zr, Ti, and Hf) on the glass structure and on the alteration kinetics of soda-lime borosilicate glasses has been studied at various stages of glass leaching corresponding to the initial dissolution rate, rate drop, and residual rate regimes. The effect of these elements on the limiting mechanisms of the glass durability as well as the chemistry of both solution and alteration layer are inter-related, depending on the reaction progress. The effect of IVB elements on the glass structure was investigated using 11B MAS NMR. The IVB elements are compensated primarily by Na rather than Ca, at the expense of tetra-coordinated boron. The addition of HfO2 or ZrO2 decreases the initial dissolution rate in a similar way. Moreover, adding ZrO2 limits the rate drop in saturated media. The initial dissolution rate decrease is less significant when Ti is added, and a quick drop of the dissolution rate is observed up to 4 mol% TiO2. At low IVB element concentration, glasses containing Ti and Zr show different residual rates arising from the precipitation of magadiite (Na2Si14O29 center dot 11H2O), at the surface of Ti-bearing glasses. The influence of IVB elements on glass alteration indicates that, unlike Ti, Zr and Hf plays a similar role in the structure of borosilicate glasses. (authors)

  9. 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)

  10. A dynamic fatigue study of soda-lime silicate and borosilicate glasses using small scale indentation flaws

    International Nuclear Information System (INIS)

    The dynamic fatigue characteristics of two glasses, soda-lime silicate and borosilicate, in water have been studied using a controlled indentation flaw technique. It is argued that the indentation approach offers several advantages over more conventional fatigue testing procedures: (i) the reproducibility of data is relatively high, eliminating statistics as a basis of analysis: (ii) the flaw ultimately responsible for failure is well defined and may be conveniently characterised before and after (and during, if necessary) the strength test; (iii) via adjustment of the indentation load, the size of the flaw can be suitably predetermined. Particular attention is devoted to the third point because of the facility it provides for systematic investigation of the range of flaw sizes over which macroscopic crack behaviour remains applicable. The first part of the paper summarises the essential fracture mechanics theory of the extension of an indentation flaw to failure. In the next part of the paper the results of dynamic fatigue tests on glass rods in distilled water are described. Data are obtained for Vickers indentation loads in the range 0.05 to 100 N, corresponding to contact dimensions of 2 to 100 μm. Finally, the implications of the results in relation to the response of 'natural' flaws are discussed. (author)

  11. The Structural Role of Zr within Alkali Borosilicate Glasses for Nuclear Waste Immobilisation

    Energy Technology Data Exchange (ETDEWEB)

    A Connelly; N Hyatt; K Travis; R Hand; E Maddrell; R Short

    2011-12-31

    Zirconium is a key constituent element of High Level nuclear Waste (HLW) glasses, occurring both as a fission product and a fuel cladding component. As part of a wider research program aimed at optimizing the solubility of zirconium in HLW glasses, we have investigated the structural chemistry of zirconium in such materials using X-ray Absorption Spectroscopy (XAS). Zirconium K-edge XAS data were acquired from several inactive simulant and simplified waste glass compositions, including a specimen of blended Magnox/UO{sub 2} fuel waste glass. These data demonstrate that zirconium is immobilized as (octahedral) six-fold coordinate ZrO{sub 6} species in these glasses, with a Zr-O contact distance of 2.09 {angstrom}. The next nearest neighbors of the Zr species are Si at 3.42 {angstrom} and possibly Na at 3.44 {angstrom}, no next nearest neighbor Zr could be resolved.

  12. FTIR and optical assessment of zinc doped calcium phospho-borosilicate sol-gel glasses/glass-ceramics

    Science.gov (United States)

    Kumar, V.; Arora, N.; Pandey, O. P.; Kaur, G.

    2015-08-01

    CaO-P2O5-ZnO-SiO2-B2O3 glasses with varying compositions of calcium oxide and phosphorous oxide are synthesized using sol-gel technique. The glasses are heat-treated for a duration of 10 h at 500°C to obtain the glass-ceramics. The glass-ceramics and glasses are characterized using Fourier transform infrared spectroscopy (FTIR) and UV-Visible spectroscopy. Extinction coefficients, attenuation coefficients and dielectric constant have been obtained for all the glasses as well as glass ceramics. The results are discussed in light of non-bridging oxygens (NBO) and heat-treatment of glasses. In addition to this, the effect of calcium and phosphorous on the infra-red spectra has been analysed thoroughly.

  13. Compositional-tailoring of optical properties in IR transparent chalcogenide glasses for precision glass molding

    Science.gov (United States)

    Gleason, B.; Wachtel, P.; Musgraves, J. D.; Qiao, A.; Anheier, N.; Richardson, K.

    2013-09-01

    The structural and optical properties of AsSe chalcogenide glass, starting with As40Se60, were studied as a function of Ge or Se additions. These elements provide broad glass forming options when combined with the host matrix to allow for compositional tuning of properties. Optimization of glass composition has been shown to produce bulk glasses with a thermoptic coefficient (dn/dT) equal to zero, as well as a composition which could demonstrate a net zero change in index after precision glass molding (PGM). The bulk glass density, coefficient of thermal expansion (CTE), refractive index, and dn/dT were measured for all bulk compositions, as was the refractive index after PGM. For the bulk glasses examined, both the refractive index (measured at discrete laser wavelengths from 3.4 to10.6 μm) and dn/dT were observed to decrease as the molecular percentage of either Ge or Se is increased. Compared to the starting glass' network, additions of either Ge or Se lead to a deviation from the "optimally constrained" binary glass' average coordination number = 2.4. Additions of Se or Ge serve to decrease or increase the average coordination number (CN) of the glass, respectively, while also changing the network's polarizability. After a representative PGM process, glasses exhibited an "index drop" consistent with that seen for oxide glasses.1 Based on our evaluation, both the Gecontaining and Ge-free tielines show potential for developing unique compositions with either a zero dn/dT for the unmolded, bulk glass, as well as the potential for a glass that demonstrates a net zero "index drop" after molding. Such correlation of glass chemistry, network, physical and optical properties will enable the tailoring of novel compositions suitable for prototyping towards targeted molding behavior and final properties.

  14. 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.

  15. Long-term aqueous alteration kinetics of an alpha-doped SON68 borosilicate glass

    OpenAIRE

    TRIBET M.; ROLLAND Séverine; S. Peuget; Magnin, Magali; BROUDIC Véronique; JANSSEN ARNE; Wiss, Thierry; JEGOU C.; Toulhoat, Pierre

    2013-01-01

    The long-term behavior of nuclear glass subjected to alpha radiation by minor actinides must be investigated with a view to geological disposal. This study focuses on the effect of alpha radiation on the chemical reactivity of R7T7 glass with pure water, mainly on the residual alteration rate regime. A glass specimen doped with 0.85 wt% 239PuO2 (α emitter) is leached under static conditions in argon atmosphere at 90°C and at a high surface-area-to-volume ratio (S/V = 20 cm-1). The alteration ...

  16. Effect of cerium oxide addition on electrical and physical properties of alkali borosilicate glasses

    International Nuclear Information System (INIS)

    The study of electrical conductivity, density and coefficient of thermal expansion (CTE) of Na2O:K2O:B2O3:SiO2:BaO glass samples with addition of cerium oxide has been carried out. It has been observed that the addition of cerium oxide affects the electrical conductivity, density and CTE. The results have been explained on the basis of the variation in number of bridging oxygens (BOs) and non-bridging oxygens (NBOs) present in the glass. In general, the glass with more NBOs has a weak network which exhibits higher electrical conductivity. The weakening of the network has been supported by the observed decrease in density and increase in CTE for the glasses.

  17. Experimental Study and Monte Carlo Modeling of Calcium Borosilicate Glasses Leaching

    International Nuclear Information System (INIS)

    During aqueous alteration of glass an alteration layer appears on the glass surface. The properties of this alteration layer are of great importance for understanding and predicting the long-term behavior of high-level radioactive waste glasses. Numerical modeling can be very useful for understanding the impact of the glass composition on its aqueous reactivity and long-term properties but it is quite difficult to model these complex glasses. In order to identify the effect of the calcium content on glass alteration, seven oxide glass compositions (57SiO2 17B2O3 (22-x)Na2OxCaO 4ZrO2; 0 < x < 11) were investigated and a Monte Carlo model was developed to describe their leaching behavior. The specimens were altered at constant temperature (T = 90 deg. C) at a glass-surface-area-to-solution-volume (SA/V) ratio of 15 cm-1 in a buffered solution (pH 9.2). Under these conditions all the variations observed in the leaching behavior are attributable to composition effects. Increasing the calcium content in the glass appears to be responsible for a sharp drop in the final leached boron fraction. In parallel with this experimental work, a Monte Carlo model was developed to investigate the effect of calcium content on the leaching behavior especially on the initial stage of alteration. Monte Carlo simulations performed with this model are in good agreement with the experimental results. The dependence of the alteration rate on the calcium content can be described by a quadratic function: fitting the simulated points gives a minimum alteration rate at about 7.7 mol% calcium. This value is consistent with the figure of 8.2 mol% obtained from the experimental work. The model was also used to investigate the role of calcium in the glass structure and it pointed out that calcium act preferentially as a network modifier rather than a charge compensator in this kind of glasses. (authors)

  18. Deep wet etching of borosilicate glass and fused silica with dehydrated AZ4330 and a Cr/Au mask

    International Nuclear Information System (INIS)

    This research highlights a superior glass-wet-etch technique which enables a glass wafer to be etched for more than 20 h in 49 wt% hydrofluoric acid (HF) only with Cr/Au film and a common positive photoresist, AZ4330. We demonstrated that pits on the wet-etched glass wafer were generated not only due to HF diffusion through the Cr/Au film but also due to pinholes on the Cr/Au films created by the diffusion of the Cr/Au etchant through a photoresist etching-mask during the Cr/Au wet etching process. These two types of diffusion, HF diffusion and Cr/Au etchant diffusion, were eliminated by the thermal curing of a photoresist (PR), AZ4330, before the Cr/Au wet etching process. The curing process allowed the PR to dehydrate, increased the hydrophobicity, and prevented the diffusion of the hydrophilic HF and Cr/Au etchant. Optimization of the curing process was performed, showing that curing at 130 °C for 20 min was the proper condition. With the optimized process, a 525 µm thick borosilicate glass wafer was penetrated with 49%wt HF. A fused silica wafer 525 µm thick was also wet-etched and penetrated with 49 wt% HF at 10 h. Moreover, no pits were found in wet etching of the fused silica for 20 h in 49 wt% HF. These findings demonstrate that the proposed technique allows the wet etching of a glass wafer for more than 20 h in 49%wt HF, the best result thus far. We fabricated a glass substrate with a 217.0 µm deep cavity and a penetrating through-via using the proposed technique, proving the feasibility of the product as an optical component with a surface roughness of 45.5 Å in the cavity. (paper)

  19. Molecular dynamics study of structural changes versus deposited energy dose in a sodium borosilicate glass

    Energy Technology Data Exchange (ETDEWEB)

    Bureau, G.; Delaye, J.M.; Peuget, S. [DEN/DTCD/SECM, CEA Marcoule, BP 17171, Bagnols-sur-Ceze cedex, 30207 (France); Calas, G. [IMPMC, 140 rue de Lourmel, Paris, 75015 (France)

    2008-07-01

    Assessing the long-term behavior of nuclear glass implies evaluating the impact of cumulative alpha decay induced by the minor actinides it contains. When subjected to alpha decay ({sup 244}Cm-doped glass specimens) or to external ion irradiation, some macroscopic properties vary appreciably with the dose. Above a given dose level, the properties do not evolve any more. To improve our understanding of these modifications, studies are carried out on simplified glass compositions (three oxides SiO{sub 2}, B{sub 2}O{sub 3}, Na{sub 2}O), modeled by molecular dynamics in which irradiation effects are simulated by accelerating uranium projectiles. Accumulation of displacements cascades have been performed up to 4.5*10{sup 20} keV/cm{sup 3} nuclear energy deposited in the glass. The density variations observed in actinide-doped materials is qualitatively reproduced. At high doses, the swelling tends to stabilize. Marples model is used to fit the glass swelling versus the deposited energy dose, giving the volume damaged per projectile. This volume approximates the cascade core volume, suggesting that the underlying mechanisms of volume expansion are contained in the cascade core and are thus related to the highest energy events: atom ejection and thermal quenching. On the contrary, the volumetric parameter of the Marples model applied to the other structural properties is related to a volume corresponding to the core + periphery of the cascades. (authors)

  20. Effect of boron oxide addition on the Nd3+ environment in a Nd-rich soda-lime alumino-borosilicate glass

    International Nuclear Information System (INIS)

    The environment of Nd3+ ions has been studied using optical absorption spectroscopy and EXAFS at the Nd-L3-edge, in a series of soda lime alumino-borosilicate glasses with increasing B2O3 content. The proportion of BO4 units has been determined by 11B MAS NMR in an equivalent glass series with La3+ ions replacing the majority of Nd3+ ions, and complementary information has been obtained by measuring the Nd3+ decay fluorescence times in these latter glasses. In these glasses with low Al2O3 content, the R' ratio, with R' = [Na2O(exc)]/[B2O3] and [Na2O(exc)] = [Na2O] - [Al2O3] - [ZrO2], plays a key role in controlling the structural organization and crystallization resistance, in a similar way as the R ratio in the Dell and Bray model of sodium borosilicate glasses. At R'≥ 0.5, the Nd3+ ions are located in a mixed silicate-borate environment and, by slow cooling of the melt, they tend to crystallize within a silicate apatite phase close to the Ca2Nd8(SiO4)6O2 composition. At R' ≤ 0.5, the structural results are compatible with Nd3+ ions located in a borate-type environment (not excluding Si neighbors), and, by slow cooling of the melt, they segregate with Ca2+ ions within a Si-depleted separated borosilicate phase. (authors)

  1. Lanthanide-activated Na5Gd9F32 nanocrystals precipitated from a borosilicate glass: Phase-separation-controlled crystallization and optical property

    International Nuclear Information System (INIS)

    Highlights: • Na5Gd9F32 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 Na5Gd9F32 lattice. • Luminescent color could be tuned by controlling glass crystallization temperature. - Abstract: Lanthanide-activated cubic Na5Gd9F32 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 Na5Gd9F32 lattice was in situ formed without the requirement of long-range ionic diffusion. Impressively, such fabricated glass ceramic co-doped with Yb3+/Er3+ 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

  2. A Comparison of Modifications Induced by Li3+ and Ag14+ Ion Beam in Spectroscopic Properties of Bismuth Alumino-Borosilicate Glass Thin Films

    Directory of Open Access Journals (Sweden)

    Ravneet Kaur

    2013-01-01

    Full Text Available Ion irradiation effects on the glass network and structural units have been studied by irradiating borosilicate glass thin film samples with 50 MeV Li3+ and 180 MeV Ag14+ swift heavy ions (SHI at different fluence rates ranging from 1012 ions/cm2 to 1014 ions/cm2. Glass of the composition (65-x Bi2O3-10Al2O3-(65-y B2O3-25SiO2 (x = 45, 40; y = 20, 25 has been prepared by melt quench technique. To study the effects of ionizing radiation, the glass thin films have been prepared from these glasses and characterized using XRD, FTIR, and UV-Vis spectroscopic techniques. IR spectra are used to study the structural arrangements in the glass before and after irradiation. The values of optical band gap, Urbach energy, and refractive index have been calculated from the UV-Vis measurements. The variation in optical parameters with increasing Bi2O3 content has been analyzed and discussed in terms of changes occurring in the glass network. A comparative study of the influence of Li3+ ion beam on structural and optical properties of the either glass system with Ag14+ ion is done. The results have been explained in the light of the interaction that SHI undergo on entering the material.

  3. Intense upconversion luminescence of Er3+/Yb3+ codoped oxyfluoride borosilicate glass ceramics containing Ba2GdF7 nanocrystals

    Institute of Scientific and Technical Information of China (English)

    ZHAO

    2010-01-01

    Er3+/Yb3+-codoped transparent oxyfluoride borosilicate glass ceramics containing Ba2GdF7 nanocrystals were prepared and spectroscopic properties of rare earth ions were investigated.Fluoride nanocrystals Ba2GdF7 were successfully precipitated in glass matrix,which was confirmed by X-ray diffraction(XRD)and transmission electron microscopy(TEM)results.In comparison with the as-made precursor,significant enhancement ofupconversion luminescence was observed in the Er3+/Yb3+codoped oxyfluoride glass ceramics,which may be due to the variation of coordination environment around Er3+and Yb3+ions after crystallization.The transition mechanisms of the green and red upconversion luminescence were ascribed to a two-photon process,and that of the blue upconversion luminescence was a three-photon process.

  4. Elaboration and experimental study of the Borosilicate glass GP 98/12 for the vitrification of the radioactive wastes of KfKarlsruhe Centre (R.F.A.)

    International Nuclear Information System (INIS)

    The transformation into a vitrified block of highly radioactive liquid wastes is actually the best solution for the storage in long run. In West Germany, the research institute in the field of nuclear energy (KfK) has been oriented in this way by developing industrial processes of vitrification and by following studies on the behaviour of the final products. For the fission products, the chosen glasses present good stability characteristics and are used as a first barrier during confinement. Our work, which is part of the research program on radioactive waste vitrification, consists of preparing borosilicate glass GP 98/12 and studying physical and chemical characteristics. We have also contributed to the development and the realization of glass blocks sampling system prepared at pilot scale

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

    International Nuclear Information System (INIS)

    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

  6. 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.

  7. Dielectric Properties of La2O3 Doped Composite (PbxSr1−xTiO3 Borosilicate Glass Ceramic

    Directory of Open Access Journals (Sweden)

    C. R. Gautam

    2013-01-01

    Full Text Available Ferroelectric (PbxSr1−xTiO3 (PST perovskite phase has been crystallized in borosilicate glassy matrix with a suitable choice of composition and heat treatment schedule. La2O3 is a donor dopant for PST and can make it semiconducting. Dispersion of semiconducting perovskite phase in insulating glassy matrix in glass-ceramic samples may lead to the formation of space charge polarization around crystal-glass interface, leading to a high value of effective dielectric constant, εr. Therefore, with the aim of the developing glass ceramics with high dielectric constant, glasses in the system 64[(PbxSr1−xO·TiO2]-25[2SiO2·B2O3]-5[K2O]-5[BaO]-1[La2O3] have been prepared (0.5≤x≤1. It is found that the addition of La2O3 strongly affected the crystallization and dielectric behavior of glass-ceramic with PST perovskite phase. All glass ceramic samples show a diffuse broad Curie peak in their εr versus T plots. Curie peak temperature, Tc, depends on compositions of the glass-ceramic samples as well as frequency of measurements.

  8. 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.

  9. 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

  10. Studies of local structure of Cm3+ in borosilicate glass using laser and x-ray spectroscopic methods and computational modeling

    International Nuclear Information System (INIS)

    The local environment of Cm3+ in a borosilicate glass has been probed by a combination of laser spectroscopy, structural modeling, and extended x-ray absorption fine structure (EXAFS) spectroscopy. The Stark splitting for the Cm f-f state transitions is significantly larger than the inhomogeneous line broadening that results from the disordered environment. As a result, the Cm optical spectrum can be fit using an effective operator Hamiltonian to obtain a set of crystal-field parameters. The fitting procedure, which requires the use of a descent-in-symmetry approach, provides a set of parameters for a best fit within tetragonal symmetry. These parameters are then linked to the local environment of Cm through exchange-charge modeling (ECM) of crystal field interactions. Cm in our borosilicate glass is best modeled with six oxygen ions with approximately tetragonal symmetry, and at an average distance of 2.31 (3) Aa. The results of crystal-field modeling are supported by EXAFS results. (c) 2000 American Institute of Physics

  11. Influence of zirconium on the structure of pristine and leached soda-lime borosilicate glasses: towards a quantitative approach by 17O MQMAS NMR

    International Nuclear Information System (INIS)

    17O MQMAS NMR was used to characterize the influence of zirconium on the structural organization of soda-lime borosilicate glasses. A new method of quantitative analysis of the 17O MQMAS spectra is presented, by a direct fit of the two-dimensional MQMAS spectrum which provides the resolution of all the structural groups in glasses containing up to five oxides. Additional data were also obtained from the quantitative deconvolution of the 11B MAS NMR spectra, with the help of the direct fit of MQMAS data as well. Excess of non-bridging oxygen is clearly identified in these glasses. Six-folded zirconium is preferentially compensated rather than the tetrahedral boron and calcium only partially compensate the tetrahedral boron. Alteration gels arising from glass leaching were probed by oxygen-17 supplied by the alteration solution. Most of the zirconium is inserted in the silicate network forming Si-O-Zr bonds with the same configuration in the glass and in the gel. During leaching, calcium clearly remains in the alteration gel, either near non-bridging oxygen or as a zirconium charge compensator. This quantitative approach applied to 17O MQMAS spectra demonstrates its potential for investigating the structure of increasingly complex glass and gel compositions. (authors)

  12. Silicate, borosilicate, and borate bioactive glass scaffolds with controllable degradation rate for bone tissue engineering applications. I. Preparation and in vitro degradation.

    Science.gov (United States)

    Fu, Qiang; Rahaman, Mohamed N; Fu, Hailuo; Liu, Xin

    2010-10-01

    Bioactive glass scaffolds with a microstructure similar to that of dry human trabecular bone but with three different compositions were evaluated for potential applications in bone repair. The preparation of the scaffolds and the effect of the glass composition on the degradation and conversion of the scaffolds to a hydroxyapatite (HA)-type material in a simulated body fluid (SBF) are reported here (Part I). The in vitro response of osteogenic cells to the scaffolds and the in vivo evaluation of the scaffolds in a rat subcutaneous implantation model are described in Part II. Scaffolds (porosity = 78-82%; pore size = 100-500 microm) were prepared using a polymer foam replication technique. The glasses consisted of a silicate (13-93) composition, a borosilicate composition (designated 13-93B1), and a borate composition (13-93B3), in which one-third or all of the SiO2 content of 13-93 was replaced by B2O3, respectively. The conversion rate of the scaffolds to HA in the SBF increased markedly with the B2O3 content of the glass. Concurrently, the pH of the SBF also increased with the B2O3 content of the scaffolds. The compressive strengths of the as-prepared scaffolds (5-11 MPa) were in the upper range of values reported for trabecular bone, but they decreased markedly with immersion time in the SBF and with increasing B2O3 content of the glass. The results show that scaffolds with a wide range of bioactivity and degradation rate can be achieved by replacing varying amounts of SiO(2) in silicate bioactive glass with B2O3. PMID:20544804

  13. 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.

  14. Optical parameters of Nd3+:Er3+:Yb3+co-doped borosilicate glasses and their energy transfers at high temperature

    Institute of Scientific and Technical Information of China (English)

    Li Cheng-Ben; Li Shu-Feng; Dong Bin; Cheng Yu-Qi; Yin Hai-Tao; Yang Jing; Chen Yu

    2011-01-01

    This paper reports that a series of Nd3+:Er3+:yb3+ co-doped borosilicate glasses have been prepared and their absorption spectra measured. The J-O intensity parameters Ωk (k = 2, 4, 6), spontaneous radiative lifetime Τrad,spontaneous transition probability A, fluorescence branching ratio β and oscillator strength fed of the Nd3+ ions at room temperature are calculated based on Judd-Ofelt (J-O) theory. The temperature dependence of the up-conversion photoluminescence characteristics in a Nd3+:Er3+:yb3+ co-doped sample is studied under a 978 nm semiconductor laser excitation, and the energy transfer mechanisms among Yb3+, Er3+ and Nd3+ ions are analysed. The results show that the J-O intensity parameters Ω2 increase when the Nd3+ concentration of the Nd3+:Er3+:yb3+ co-doped boresilicate glasses increases. The possibility of spontaneous transition is small and lifetimes are long at levels of 4F5/2and 4F3/2. The intensity of Nd3+ emissions at 595, 691, 753, 813 and 887 nm are markedly enhanced when the sample temperature exceeds 400 K. The reasons being the cooperation of the secondary sensitization from Er3+ to Nd3+ and the contribution of a multi-phonon.

  15. Effect of X-ray irradiation on the optical absorption of SdSe1−xTex nanocrystals embedded in borosilicate glass

    International Nuclear Information System (INIS)

    The effect of X-ray irradiation on the optical absorption spectra of CdSe1−xTex nanocrystals embedded in a borosilicate matrix is studied. The observed blue shift of the absorption edge and bleaching of the confinement-related features in the spectra are related to X-ray induced negative ionization of the nanocrystals with charge transfer across the nanocrystal/matrix interface. The radiation-induced changes are observed to recover after longer post-irradiation storage at room temperature. - Highlights: ► Absorption edge of glass-embedded CdSe1−x Tex nanocrystals is blue shifted under X-ray irradiation. ► Radiation-induced bleaching bands appear at the position of HOMO-LUMO transitions. ► The reason is charge transfer between the nanocrystals and radiation-induced centres in the glass. ► Contrary to photoionization, this is a long-lived process (over 2000 h).

  16. 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.

  17. 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.)

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

    Science.gov (United States)

    Nordin, I. H. W.; Okamoto, Y.; Okada, A.; Takekuni, T.; Sakagawa, T.

    2016-05-01

    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.

  19. 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

  20. 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。

  1. Chalcogenide glass fibers: Optical window tailoring and suitability for bio-chemical sensing

    Science.gov (United States)

    Lucas, Pierre; Coleman, Garrett J.; Jiang, Shibin; Luo, Tao; Yang, Zhiyong

    2015-09-01

    Glassy materials based on chalcogen elements are becoming increasingly prominent in the development of advanced infrared sensors. In particular, infrared fibers constitute a desirable sensing platform due to their high sensitivity and versatile remote collection capabilities for in-situ detection. Tailoring the transparency window of an optical material to the vibrational signature of a target molecule is important for the design of infrared sensor, and particularly for fiber evanescent wave spectroscopy. Here we review the basic principles and recent developments in the fabrication of chalcogenide glass infrared fibers for application as bio-chemical sensors. We emphasize the challenges in designing materials that combine good rheological properties with chemical stability and sufficiently wide optical windows for bio-chemical sensing. The limitation in optical transparency due to higher order overtones of the amorphous network vibrations is established for this family of glasses. It is shown that glasses with wide optical window suffer from higher order overtone absorptions. Compositional engineering with heavy elements such as iodine is shown to widen the optical window but at the cost of lower chemical stability. The optical attenuations of various families of chalcogenide glass fibers are presented and weighed for their applications as chemical sensors. It is then shown that long-wave infrared fibers can be designed to optimize the collection of selective signal from bio-molecules such as cells and tissues. Issues of toxicity and mechanical resistance in the context of bio-sensing are also discussed.

  2. 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)

  3. 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.

  4. Effects of alpha, gamma, and alpha-recoil radiation on borosilicate glass containing Savannah River Plant defense high-level nuclear waste. [Lead ions-250 keV; xenon ions-160 keV

    Energy Technology Data Exchange (ETDEWEB)

    Bibler, N.E.

    1981-01-01

    At the Savannah River Plant, the reference process for the immobilization of defense high-level waste (DHLW) for geologic storage is vitrification into borosilicate glass. During geologic storage for 10/sup 6/ y, the glass would be exposed to approx. 3 x 10/sup 10/ rad of ..beta.. radiation, approx. 10/sup 10/ rad of ..gamma.. radiation, and 10/sup 18/ particles/g glass for both ..cap alpha.. and ..cap alpha..-recoil radiation. This paper discusses tests of the effect of these radiations on the leachability and density of the glass. Even though the doses were large, no effect of the radiations was detected that reduced the effectiveness of the glass for long-term storage of DHLW even at doses corresponding to 10/sup 6/ years storage for the actual glass. For the tests, glass containing simulated DHLW was prepared from frit of the reference composition. Three methods were used to irradiate the glass: external irradiations with beams of approx. 200 keV Xe or Pb ions, internal irradiations with Cm-244 doped glass, and external irradiations with Co-60 ..gamma.. rays. Results with both Xe and Pb ions indicate that a dose of 3 x 10/sup 13/ ions/cm/sup 2/ (simulating > 10/sup 6/ years storage) does not significantly increase the leachability of the glass in deionized water. Tests with Cm-244 doped glass show no increase in leach rate in water or brine up to a dose of 10/sup 18/ ..cap alpha.. and ..cap alpha..-recoils/g glass. Results of larger doses are being examined. The density of the Cm-244 doped glass has decreased by 1% at a dose of 10/sup 18/ particles/g glass. With ..gamma..-radiation, the density has changed by < 0.05% at a dose of 8.5 x 10/sup 10/ rad. Results of leach tests in deionized water and brine indicated that this very large dose of ..gamma..-radiation increased the leach rate by only 20%. Also, the leach rates are lower in brine.

  5. Liquid phase sintering of 20Bi(Zn0.5Ti0.5)O 3-80BaTiO3 dielectrics with bismuth-zinc-borate and bismuth borosilicate glasses

    Science.gov (United States)

    Shahin, David I.

    Dielectrics in the Bi(Zn0.5Ti0.5)O3-BaTiO 3 system (specifically 20BZT-80BT, in mol%) are promising candidates for high energy density capacitor applications due to broad temperature-dependent dielectric constant maxima and a relatively field-independent permittivity. Bulk samples require sintering temperatures of greater than 1180°C to reach useful densities. Due to incompatibility of Bi with low-pO2 processing, BZT-BT-based multilayer capacitors must utilize noble metal electrodes that resist oxidation during sintering. Sintering temperatures must be reduced to allow use of less expensive electrode materials (Cu, etc.). This work studies the reduced temperature sintering behavior and dielectric properties of BZT-BT sintered with 30Bi2O3-30ZnO-40B 2O3 and 50Bi2O3-25B2O 3-25SiO2 (mol%) liquid phase formers. Dielectrics sintered with 1v% borate additions and 5v% additions of either the borate or borosilicate achieved relative densities greater than 95% after sintering at 1000°C for four hours. All compositions retained the relaxor behavior exhibited by pure 20BZT-80BT. Increased borate additions led to greater dielectric constant reductions, while increased borosilicate additions yielded no clear trend in the dielectric constant reduction. Energy densities were estimated between 0.3-0.5 J/cm3; smaller glass additions typically led to larger energy densities. Dielectrics sintered with 1v% borate additions are of interest due to their high relative densities (approx. 96%) and energy densities of approximately 0.5 J/cm3 under 100kV/cm electric fields. Studies of BZT-BT/glass interfaces revealed the formation of crystalline interfacial layers less than 10 microns thick. The borate formed a bismuth titanate phase (likely Bi4Ti3O12) during heating to 700°C, whereas the borosilicate formed a barium silicate phase (likely BaSiO3) during processing to 800°C. Similar phases are expected to be present in the liquid phase sintered dielectrics and likely affect the BZT

  6. 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)

  7. 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

  8. 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.

  9. Tailoring the size and distribution of Ag nanoparticles in silica glass by defects

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yitao, E-mail: yangyt@impcas.ac.cn [Materials Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Zhang, Chonghong; Song, Yin; Gou, Jie; Zhang, Liqing [Materials Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Zhang, Hengqing; Liu, Juan; Xian, Yongqiang [Materials Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Ma, Yizhun [Materials Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)

    2014-02-15

    The composites embedded with metallic nanoparticles show large nonlinear optical susceptibility and strong surface plasmon resonance absorption, which enable potential application in opto-electronics. Ion implantation has been proven to be a powerful technique of synthesis of metallic nanoparticles due to its versatility and compatibility. However, the synthesis of nanoparticles by ion implantation inevitably leads to a broad size distribution due to Ostwald ripening process. The broad size distribution has a negative effect on improving the figure of merits for nonlinear optics. In this paper, we tried to introduce defects in silica glass to act as pre-nucleation centers to mediate the size and distribution of Ag nanoparticles. In experiment, the silica glass samples were pre-irradiated by 200 keV Ar ions to fluences of 0.8, 2.0 and 5.0 × 10{sup 16} ions/cm{sup 2}, and then 200 keV Ag ions were implanted into the pre-irradiated samples to fluence of 2.0 × 10{sup 16} ions/cm{sup 2}. UV–VIS results show that the absorbance intensity of Ag SPR peak initially increases and then decreases with pre-irradiation fluence, which implies the change in size and density of Ag nanoparticles in samples. TEM results verify that Ag nanoparticles in the sample pre-irradiated to the fluence of 0.8 × 10{sup 16} ions/cm{sup 2} grow bigger and distribute in a relatively narrow region comparing with that without pre-irradiation. With further increase of pre-irradiation fluence, the size of Ag nanoparticles shows a depth dependent distribution. A boundary can be clear seen at the depth of 110 nm, larger Ag nanoparticles disperse in region shallower than 110 nm, and smaller Ag nanoparticles disperse in the region deeper than 110 nm. The average size of Ag nanoparticles initially increases and then decreases with pre-irradiation fluence. Therefore, the introduction of defects by pre-irradiation could be an effective way to tailor the size and distribution of metallic nanoparticles in

  10. Single-pulse laser ablation threshold of borosilicate, fused silica, sapphire, and soda-lime glass for pulse widths of 500  fs, 10  ps, 20  ns.

    Science.gov (United States)

    Nieto, Daniel; Arines, Justo; O'Connor, Gerard M; Flores-Arias, María Teresa

    2015-10-10

    In this work, we report a comparative study of the laser ablation threshold of borosilicate, fused silica, sapphire, and soda-lime glass as a function of the pulse width and for IR laser wavelengths. We determine the ablation threshold for three different pulse durations: τ=500  fs, 10 ps, and 20 ns. Experiments have been performed using a single laser pulse per shot in an ambient (air) environment. The results show a significant difference, of two orders of magnitude, between the group of ablation thresholds obtained for femtosecond, picosecond, and nanosecond pulses. This difference is reduced to 1 order of magnitude in the soda-lime substrate with tin impurities, pointing out the importance of the incubation effect. The morphology of the marks generated over the different glass materials by one single pulse of different pulse durations has been analyzed using a scanning electron microscope (FESEM ULTRA Plus). Our results are important for practical purposes, providing the ablation threshold data of four commonly used substrates at three different pulse durations in the infrared regime (1030-1064 nm) and complete data for increasing the understanding of the differences in the mechanism's leading ablation in the nanosecond, picosecond, and femtosecond regimes. PMID:26479792

  11. Spherical gold nanoparticles and SiO{sub 2}/Au core/shell microparticles under intense femtosecond laser excitation: relaxation dynamics of gold nanoparticles and nanostructuring of borosilicate glass using SiO{sub 2}/Au microparticles

    Energy Technology Data Exchange (ETDEWEB)

    Shakhov, A M; Astaf' ev, A A; Gostev, F E; Shelaev, I V; Titov, A N; Nadtochenko, V A [N N Semenov Institute of Chemical Physics, Russian Academy of Sciences, Moscow (Russian Federation); Denisov, N N [Institute of Problems of Chemical Physics, Russian Academy of Sciences, Chernogolovka, Moscow Region (Russian Federation)

    2014-09-30

    This paper reports surface nanostructuring of borosilicate glass covered with a water layer and the production of ∼150 nm diameter pits using SiO{sub 2}/Au core/shell microparticles under excitation with 50 fs pulses (λ = 780 nm) using the optical scheme of an inverted microscope with a 100{sup ×}, NA = 1.4 objective. We compare the thresholds for hole formation in glass with the use of SiO{sub 2}/Au and uncoated SiO{sub 2} microparticles. The threshold is 0.7 J cm{sup -2} for SiO{sub 2}/Au and 2.9 J cm{sup -2} for SiO{sub 2} microparticles, which coincides with the threshold for nanostructuring by a focused femtosecond pulse without microparticles: 3 J cm{sup -2}. Femtosecond pump – probe spectroscopy has been used to study the relaxation dynamics of laser pulse energy absorbed in a Au nanoparticle and the dynamics of energy dissipation to the ambient medium. The threshold for cavitation bubble formation in water with SiO{sub 2}/Au has been determined to be 0.06 mJ cm{sup -2}, which is a factor of 30 lower than the bubble formation threshold in the case of uncoated SiO{sub 2} microparticles. (nanostructures)

  12. Phase separation and crystallization in soda-lime borosilicate glass enriched in MoO3 studied by in situ Raman spectroscopy at high temperature

    OpenAIRE

    Magnin, Magali; Schuller, Sophie; Caurant, Daniel; Majérus, Odile; De Ligny, Dominique; Advocat, Thierry

    2008-01-01

    Phase separation and crystallisation processes may arise in molten glass when the MoO3 content exceeds its solubility limit. Molybdenum combined with other elements such as alkali and alkaline-earth may form crystalline molybdates, known as "yellow phases" in nuclear glasses. In order to establish the sequence of phase separation and crystallization processes occurring during the cooling of the melt, a non-radioactive simplified glass composition was chosen in the SiO2-B2O3Na2O-CaO system, wi...

  13. 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.

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

    International Nuclear Information System (INIS)

    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

  15. Phosphate glass fibre scaffolds: Tailoring of the properties and enhancement of the bioactivity through mesoporous glass particles.

    Science.gov (United States)

    Novajra, G; Boetti, N G; Lousteau, J; Fiorilli, S; Milanese, D; Vitale-Brovarone, C

    2016-10-01

    Novel bone glass fibre scaffolds were developed by thermally bonding phosphate glass fibres belonging to the P2O5-CaO-Na2O-SiO2-MgO-K2O-TiO2 system (TiPS2.5 glass). Scaffolds with fibres of 85 or 110μm diameter were fabricated, showing compressive strength in the range of 2-3.5MPa, comparable to that of the trabecular bone. The effect of different thermal treatments and fibre diameters and length on the final scaffold structure was investigated by means of micro-CT analysis. The change of the sintering time from 30 to 60min led to a decrease in the scaffold overall porosity from 58 to 21vol.% for the 85μm fibre scaffold and from 50 to 40vol.% when increasing the sintering temperature from 490 to 500°C for the 110μm fibre scaffold. The 85μm fibres resulted in an increase of the scaffold overall porosity, increased pore size and lower trabecular thickness; the use of different fibre diameters allowed the fabrication of a scaffold showing a porosity gradient. In order to impart bioactive properties to the scaffold, for the first time in the literature the introduction in these fibre scaffolds of a bioactive phase, a melt-derived bioactive glass (CEL2) powder or spray-dried mesoporous bioactive glass particles (SD-MBG) was investigated. The scaffold bioactivity was assessed through soaking in simulated body fluid. CEL2/glass fibre scaffold did not show promising results due to particle detachment from the fibres during soaking in simulated body fluid. Instead the use of mesoporous bioactive powders showed to be an effective way to impart bioactivity to the scaffold and could be further exploited in the future through the ability of mesoporous particles to act as systems for the controlled release of drugs. PMID:27287156

  16. Alteration layer formation of Ca- and Zn-oxide bearing alkali borosilicate glasses for immobilisation of UK high level waste: A vapour hydration study

    Science.gov (United States)

    Cassingham, N. J.; Corkhill, C. L.; Stennett, M. C.; Hand, R. J.; Hyatt, N. C.

    2016-10-01

    The UK high level nuclear waste glass modified with CaO/ZnO was investigated using the vapour phase hydration test, performed at 200 °C, with the aim of understanding the impact of the modification on the chemical composition and microstructure of the alteration layer. Experiments were undertaken on non-modified and CaO/ZnO-modified base glass, with or without 25 wt% of simulant Magnox waste calcine. The modification resulted in a dramatic reduction in gel layer thickness and also a reduction in the reaction rate, from 3.4 ± 0.3 g m-2 d-1 without CaO/ZnO modification to 0.9 ± 0.1 g m-2 d-1 with CaO/ZnO. The precipitated phase assemblage for the CaO/ZnO-modified compositions was identified as hydrated Ca- and Zn-bearing silicate phases, which were absent from the non-modified counterpart. These results are in agreement with other recent studies showing the beneficial effects of ZnO additions on glass durability.

  17. Tailoring Cell Behavior on Polymers by the Incorporation of Titanium Doped Phosphate Glass Filler

    OpenAIRE

    W. Chrzanowski; Abou Neel, E. A.; Lee, K. Y.; Bismarck, A.; Young, A. M.; Hart, A. D.; Dalby, M. J.; Knowles, J. C.

    2010-01-01

    Understanding tissue response to materials, to enable modulation and guided tissue regeneration is one of the main challenges in biomaterials science. Nowadays polymers, glasses, and metals dominate as biomaterials. Often native properties of those materials are not sufficient and there is a need to combine them, so as to modify and adjust their properties to the application. The primary aim of this study was to improve cell response to polymer (PLDL) using phosphate glass as filler (titanium...

  18. Tailored spectroscopic and optical properties in rare earth-activated glass-ceramics planar waveguides

    Science.gov (United States)

    Ristic, Davor; Van Tran, Thi Thanh; Dieudonné, Belto; Cristina, Armellini; Berneschi, Simone; Chiappini, Andrea; Chiasera, Alessandro; Varas, Stefano; Carpentiero, Alessandro; Mazzola, Maurizio; Nunzi Conti, Gualtiero; Pelli, Stefano; Speranza, Giorgio; Feron, Patrice; Duverger Arfuso, Claire; Cibiel, Gilles; Turrell, Sylvia; Tran Ngoc, Khiem; Boulard, Brigitte; Righini, Giancarlo C.; Ferrari, Maurizio

    2013-03-01

    Glass ceramic activated by rare earth ions are nanocomposite systems that exhibit specific morphologic, structural and spectroscopic properties allowing to develop interesting new physical concepts, for instance the mechanism related to the transparency, as well as novel photonic devices based on the enhancement of the luminescence. At the state of art the fabrication techniques based on bottom-up and top-down approaches appear to be viable although a specific effort is required to achieve the necessary reliability and reproducibility of the preparation protocols. In particular, the dependence of the final product on the specific parent glass and on the employed synthesis still remain an important task of the research in material science. Glass-ceramic waveguides overcome some of the efficiency problems experienced with conventional waveguides. These two-phase materials are composed of nanocrystals embedded in an amorphous matrix. The respective volume fractions of the crystalline and amorphous phases determine the properties of the glass ceramic. They also represent a valid alternative to widely used glass hosts such as silica as an effective optical medium for light propagation and luminescence enhancement. Looking to application, the enhanced spectroscopic properties typical of glass ceramic in respect to those of the amorphous structures constitute an important point for the development of integrated optics devices, including optical amplifiers, monolithic waveguide laser, novel sensors, coating of spherical microresonators, and up and down converters for solar energy exploitation.

  19. Synthesis and thermophysical property measurements on various types of glasses for nuclear waste immobilization

    International Nuclear Information System (INIS)

    Borosilicate glasses (BSG) are worldwide known host matrices for immobilization of radioactive High Level Waste (HLW). Different types of borosilicate glasses were prepared by changing the modifier concentrations and compositions to know the efficacy of the resulting glass in terms of glass formation, durability towards various waste elements, stability at higher temperatures, mobility of ionic species etc. towards nuclear applications. In this study BSG, Aluminium borosilicate glass (AlBSG), Barium borosilicate glass (BaBSG) and Lead borosilicate glasses (PbBSG) were prepared and characterised to confirm the glass formations. Percentage linear thermal expansion and glass transition temperatures were measured by dilatometric techniques

  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. Effect of ZnO and CaO on Alkali Borosilicate Glass Waste-form Immobilizing Simulated Mixed HLW%ZnO 和 CaO对模拟高放废液硅酸盐玻璃固化体性能的影响研究

    Institute of Scientific and Technical Information of China (English)

    张华; N.C.Hyatt; J.R.Stevens; R.Hand

    2015-01-01

    针对有些高放废液含有较多Fe、Cr、Ni过渡金属元素,在玻璃固化工艺过程中易于形成晶体,导致熔融玻璃体的黏度增加、化学稳定性变差以及工艺过程中易出现出料口堵塞等问题,研究了废物包容量为15%和20%、添加ZnO (5.6%)和CaO (1.75%)的配方对形成的4种玻璃固化体的物理性能(密度、硬度、断裂韧性)、化学性能(产品一致性测试和蒸汽腐蚀测试)和结构(X射线衍射析晶分析、拉曼光谱分析)的影响。研究分析显示,提高废物包容量至20%以及添加ZnO和CaO均可促进硼硅酸盐玻璃固化体网络结构的稳定性和化学稳定性,并增强玻璃体的密度,提高硬度;但玻璃固化体的高温黏度升高,断裂韧性下降。%Since the transit metals ,such as Fe ,Cr and Ni ,contained in some kinds of mixed HLW ,can likely to form crystal ,increase the melt viscosity ,destroy the chemi‐cal durability and block the discharge port .T he results obtained from investigating four glass waste‐forms ,including the alkali borosilicate glass matrix and alkali borosilicate glass matrix doped with 5.6% ZnO and 1.75% CaO in base matrixes ,immobilizing the simulated mixed HLW with 15% and 20% waste loadings aiming to determinate the effect of ZnO on the alkali borosilicate glass chemical durability with waste loading increasing ,were presented in this paper .Glass samples were characterized with XRD and Raman spectroscopy .The chemical durability was investigated using the standard protocols PCT and VHT .The XRD analysis results show that spinel crystal appears and grows in glass samples at the waste loading in 20% without ZnO addition and waste loading in 15% and 20% added ZnO .T he Raman spectroscopy analysis results indicate that ZnO and CaO can enhance the glass network connective ,and the chemical durability test results display that the addition of ZnO and CaO can improve the short term

  2. Influence of (Na2O-Al2O3)/B2O3 on Viscosity and Thermal Properties of Silica-rich Borosilicate Glasses%(Na2O-Al2O3)/B2O3对高硼硅酸盐玻璃粘度和热学性能的影响

    Institute of Scientific and Technical Information of China (English)

    何峰; 平财明; 郑媛媛; 乔勇

    2013-01-01

    采用熔融冷却法制备了不同R’系数的高硼硅酸盐玻璃,其中R’=(Na2O-Al2O3)/B2O3.利用红外光谱、高温旋转粘度计和热膨胀仪等对玻璃的结构和性能进行表征.结果表明:高温段粘度-温度关系符合阿伦尼乌斯定律;R’值的增大导致非桥氧的增加,高温粘度和熔制温度呈显著降低.当R’>0.5时,热膨胀系数近似线性增大,玻璃化转变温度增大至590℃基本维持不变.R’值影响结构中的[BO3]与[BO4]的比例及硅氧网络的完整程度,从而决定高硼硅酸盐玻璃的性能.%Silica-rich sodium borosilicate glasses with varying R' values have been prepared using conventional melt quenching method,where R' represents the ratio of (Na2O-Al2O3) and B2O3.The structure and properties have been investigated by the FTIR spectra,rotating crucible viscometer and thermal expanse dilatometer.The results show that the viscosity dependence of temperature is accord with Arrhenius law in the high temperature range.The non-bridging oxygen increases due to the increase of R',which leads to obvious decease of high temperature viscosity and melting temperature.Thermal expanse coefficient increases linearly with R' when R' exceeds 0.5,and the glass transformation temperature increases to 590 ℃.The fraction of [BO3] and [BO4] and the integrity of Si-O network are controlled mainly by R',then decide properties of borosilicate glasses.

  3. Introduction - Acid decomposition of borosilicate ores

    International Nuclear Information System (INIS)

    The complex processing of mineral raw materials is an effective way for the extraction of valuable components. One of these raw materials are borosilicate ores from which the boric acid, aluminium and iron salts and building materials can be obtained. In the Institute of Chemistry of the Academy of Sciences of the Republic of Tajikistan the flowsheets of the processing of borosilicate raw materials by acid and chloric methods were elaborated. The acid methods of decomposition of borosilicate ores of Ak-Arkhar Deposit were considered in present monograph. The carried out researches on elaboration of physicochemical aspects and technological acid methods allowed to define the optimal ways of extraction of valuable products from borosilicate raw materials of Tajikistan.

  4. Optically transparent, mechanically durable, nanostructured superhydrophobic surfaces enabled by spinodally phase-separated glass thin films

    Science.gov (United States)

    Aytug, Tolga; Simpson, John T.; Lupini, Andrew R.; Trejo, Rosa M.; Jellison, Gerald E.; Ivanov, Ilia N.; Pennycook, Stephen J.; Hillesheim, Daniel A.; Winter, Kyle O.; Christen, David K.; Hunter, Scott R.; Haynes, J. Allen

    2013-08-01

    We describe the formation and properties of atomically bonded, optical quality, nanostructured thin glass film coatings on glass plates, utilizing phase separation by spinodal decomposition in a sodium borosilicate glass system. Following deposition via magnetron sputtering, thermal processing and differential etching, these coatings are structurally superhydrophilic (i.e., display anti-fogging functionality) and demonstrate robust mechanical properties and superior abrasion resistance. After appropriate chemical surface modification, the surfaces display a stable, non-wetting Cassie-Baxter state and exhibit exceptional superhydrophobic performance, with water droplet contact angles as large as 172°. As an added benefit, in both superhydrophobic and superhydrophilic states these nanostructured surfaces can block ultraviolet radiation and can be engineered to be anti-reflective with broadband and omnidirectional transparency. Thus, the present approach could be tailored toward distinct coatings for numerous markets, such as residential windows, windshields, specialty optics, goggles, electronic and photovoltaic cover glasses, and optical components used throughout the US military.

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

    International Nuclear Information System (INIS)

    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. Comparison of glass and crystalline nuclear waste forms

    International Nuclear Information System (INIS)

    Nuclear waste forms may be divided into two broad categories: single phase glasses with minor crystalline components (e.g., borosilicate glasses) and crystalline waste forms, either single phase (e.g., monazite) or polyphase (e.g., SYNROC). This paper reviews the materials properties data that are available for each of these two types of waste forms. The principal data include: physical, thermal and mechanical properties, chemical durability; and radiation damage effects. Complete data are only available for borosilicate glasses and SYNROC; therefore, this comparison focuses on the performance assessment of borosilicate glass and SYNROC

  7. 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....

  8. Tailoring the sealing properties of TiO2-CaO-SrO-B2O3-SiO2 glass-ceramic seals: Thermal properties, chemical compatibility and electrical property

    Science.gov (United States)

    Chen, Jialin; Zou, Qi; Zeng, Fanrong; Wang, Shaorong; Tang, Dian; Yang, Hsiwen; Zhang, Teng

    2013-11-01

    In this paper, TiO2 is added to CaO-SrO-B2O3-SiO2 sealing system to tailor the sealing properties of glass-ceramic seals. The coefficient of thermal expansion (CTE) of quenched glasses and glass-ceramics (held at 750 °C for 100 h) does not change significantly with the addition of TiO2; whereas, the glass stability (ΔTxg = Tx - Tg) decreases systematically with increasing TiO2. The addition of TiO2 accelerates the crystallization of sealing glasses. The formation of Sr-containing phase, e.g., Sr(TiO3), contributes to the improved chemical compatibility as well as the increase in conductivity of sealing glasses (e.g., from 7.9 × 10-8 S cm-1 to 6.9 × 10-5 S cm-1 at 800 °C). In addition, the good bonding is observed at the interface between Cr-containing interconnect (430SS) and glasses containing 4-8 mole % TiO2, held at 750 °C for 100 h.

  9. Spent fuel from nuclear research reactors immobilized in sintered glass

    International Nuclear Information System (INIS)

    Different kinds of glasses, borosilicates, Iron borosilicates and Iron phosphates, were tested in order to determine its capability to immobilize calcined uranium silicide in a sintering process. Iron phosphate glass developed in our laboratory showed the best results in SEM analysis. Also its gravimetric leaching rate is less than 0.45 g.m-2 .day-1 for 7 and 10% loading which is lower than any previously studied for us. (author)

  10. Volume changes in glass induced by an electron beam

    International Nuclear Information System (INIS)

    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

  11. Phase Stability Determinations of DWPF Waste Glasses

    Energy Technology Data Exchange (ETDEWEB)

    Marra, S.L.

    1999-10-22

    Liquid high-level nuclear waste will be immobilized at the Savannah River Site (SRS) by vitrification in borosilicate glass. To fulfill this requirement, glass samples were heat treated at various times and temperatures. These results will provide guidance to the repository program about conditions to be avoided during shipping, handling and storage of DWPF canistered waste forms.

  12. Fabrication of Silicon Nitride Dental Core Ceramics with Borosilicate Veneering material

    Science.gov (United States)

    Wananuruksawong, R.; Jinawath, S.; Padipatvuthikul, P.; Wasanapiarnpong, T.

    2011-10-01

    Silicon nitride (Si3N4) ceramic is a great candidate for clinical applications due to its high fracture toughness, strength, hardness and bio-inertness. This study has focused on the Si3N4 ceramic as a dental core material. The white Si3N4 was prepared by pressureless sintering at relative low sintering temperature of 1650 °C in nitrogen atmosphere. The coefficient of thermal expansion (CTE) of Si3N4 ceramic is lower than that of Zirconia and Alumina ceramic which are popular in this field. The borosilicate glass veneering was employed due to its compatibility in thermal expansion. The sintered Si3N4 specimens represented the synthetic dental core were paintbrush coated by a veneer paste composed of borosilicate glass powder (veneer on the Si3N4 specimens, the firing was performed in electric tube furnace between 1000-1200°C. The veneered specimens fired at 1100°C for 15 mins show good bonding, smooth and glossy without defect and crazing. The veneer has thermal expansion coefficient as 3.98×10-6 °C-1, rather white and semi opaque, due to zirconia addition, the Vickers hardness as 4.0 GPa which is closely to the human teeth.

  13. Study of the possibilities of using nuclear methods for characterizing the surface region of glasses

    International Nuclear Information System (INIS)

    Following a review of the different methods used for the analysis of surfaces, we give a detailed description of charged particle elastic backscattering and the experimental devices. We then apply this method to the study of the lixiviation of borosilicate glasses in aqueous media and to the characterization of two heavy elements, cerium and thorium and their possible interaction in simple borosilicates

  14. Luminescence of powdered uranium glasses

    Science.gov (United States)

    Eubanks, A. G.; Mcgarrity, J. M.; Silverman, J.

    1974-01-01

    Measurement of cathodoluminescence and photoluminescence efficiencies in powdered borosilicate glasses having different particle size and different uranium content. Excitation with 100 to 350 keV electrons and with 253.7 nm light was found to produce identical absolute radiant exitance spectra in powdered samples. The most efficient glass was one containing 29.4 wt% B2O3, 58.8 wt% SiO2, 9.8 wt% Na2O and 2.0 wt% UO2.

  15. Excimer laser-induced material modification to create nanometer high smooth patterns in glass using mask projection

    Energy Technology Data Exchange (ETDEWEB)

    Rudolph, Thomas; Zimmer, Klaus; Boehme, Rico; Ruthe, David [Leibniz-Institut fuer Oberflaechenmodifizierung e.V., Permoserstrasse 15, D-04318 Leipzig (Germany)

    2007-04-15

    Laser swelling of borosilicate and soda-lime glass is shown for wavelengths of 193 and 248 nm. Very smooth patterns up to 45 nm high were generated by KrF laser (248 nm) irradiation of borosilicate glass at a fluence of 1.5 J/cm{sup 2}. At 193 nm laser wavelength, lower heights (up to 13 nm) and lower swelling threshold fluences (0.1 J/cm{sup 2}) were observed due to higher material absorption. For the less absorbing soda-lime glass higher fluences than for the borosilicate glass are needed to establish elevated structures. Gratings in borosilicate glass with sub-micron periodicity demonstrate the high resolution of the method. The results can be explained by a thermo-physical model based on the change of the glass transition temperature due to fast cooling after the pulsed laser irradiation.

  16. Feasibility Study for Preparation and Use of Glass Grains as an Alternative to Glass Nodules for Vitrification of Nuclear Waste

    International Nuclear Information System (INIS)

    High level nuclear liquid waste (HLW) is immobilized using borosilicate glass matrix. Presently joule heated ceramic melter is being employed for vitrification of HLW in India. Preformed nodules of base glass are fed to melter along with liquid waste in predetermined ratio. In order to reduce the cost incurred for production of glass nodules of base glass, an alternative option of using glass grains was evaluated for its preparation and its suitability for the melter operation. (author)

  17. Tailored ceramics

    International Nuclear Information System (INIS)

    In polyphase tailored ceramic forms two distinct modes of radionuclide immobilization occur. At high waste loadings the radionuclides are distributed through most of the ceramic phases in dilute solid solution, as indicated schematically in this paper. However, in the case of low waste loadings, or a high loading of a waste with low radionuclide content, the ceramic can be designed with only selected phases containing the radionuclides. The remaining material forms nonradioactive phases which provide a degree of physical microstructural isolation. The research and development work with polyphase ceramic nuclear waste forms over the past ten years is discussed. It has demonstrated the critical attributes which suggest them as a waste form for future HLW disposal. From a safety standpoint, the crystalline phases in the ceramic waste forms offer the potential for demonstrable chemical durability in immobilizing the long-lived radionuclides in a geologic environment. With continued experimental research on pure phases, analysis of mineral analogue behavior in geochemical environments, and the study of radiation effects, realistic predictive models for waste form behavior over geologic time scales are feasible. The ceramic forms extend the degree of freedom for the economic optimization of the waste disposal system

  18. Method for making glass

    International Nuclear Information System (INIS)

    A method for making better quality molten (borosilicate and other) glass in a glass melter, the glass having the desired viscosity and, preferably, also the desired resistivity so that the glass melt can be established effectively and the product of the glass melter will have the desired level of quality. The method includes the adjustment of the composition of the a ass constituents that are fed into the melterin accordance with certain correlations that reliably predict the viscosity and resistivity from the melter temperature and the melt composition, then heating the ingredients to the melter's operating temperature until they melt and homogenize. The equations include the calculation of a ''non-bridging oxygen'' term from the numbers of moles of the various ingredients, and then the determination of the viscosity and resistivity from the operating temperature of the melter and the non-bridging oxygen term

  19. Fabrication of Silicon Nitride Dental Core Ceramics with Borosilicate Veneering material

    Energy Technology Data Exchange (ETDEWEB)

    Wananuruksawong, R; Jinawath, S; Wasanapiarnpong, T [Research Unit of Advanced Ceramic, Department of Materials Science, Faculty of Science, Chulalongkorn University, Bangkok (Thailand); Padipatvuthikul, P, E-mail: raayaa_chula@hotmail.com [Faculty of Dentistry, Srinakharinwirot University, Bangkok (Thailand)

    2011-10-29

    Silicon nitride (Si{sub 3}N{sub 4}) ceramic is a great candidate for clinical applications due to its high fracture toughness, strength, hardness and bio-inertness. This study has focused on the Si{sub 3}N{sub 4} ceramic as a dental core material. The white Si{sub 3}N{sub 4} was prepared by pressureless sintering at relative low sintering temperature of 1650 deg. C in nitrogen atmosphere. The coefficient of thermal expansion (CTE) of Si{sub 3}N{sub 4} ceramic is lower than that of Zirconia and Alumina ceramic which are popular in this field. The borosilicate glass veneering was employed due to its compatibility in thermal expansion. The sintered Si{sub 3}N{sub 4} specimens represented the synthetic dental core were paintbrush coated by a veneer paste composed of borosilicate glass powder (<150 micrometer, Pyrex) with 5 wt% of zirconia powder (3 wt% Y{sub 2}O{sub 3} - partial stabilized zirconia) and 30 wt% of polyvinyl alcohol (5 wt% solution). After coating the veneer on the Si{sub 3}N{sub 4} specimens, the firing was performed in electric tube furnace between 1000-1200 deg. C. The veneered specimens fired at 1100 deg. C for 15 mins show good bonding, smooth and glossy without defect and crazing. The veneer has thermal expansion coefficient as 3.98x10{sup -6} deg. C{sup -1}, rather white and semi opaque, due to zirconia addition, the Vickers hardness as 4.0 GPa which is closely to the human teeth.

  20. Radiolysis of hexane absorbing on borosilicate surface research

    International Nuclear Information System (INIS)

    The radiolysis process of hexane absorbing on borosilicate with various hydration degree is being investigated. Samples of borosilicate were treated by thermal vacuum at and T=493 K and P=1.33·10-4 Pa. The absorption of water and hexane was carried out on manometric equipment at 77 K temperature. An irradiation was conducted by γ-rays from 60Co source in the sealed in ampoules at 77 K with 10 kGy dose. In the irradiated samples the ESR spectrum with wide range that is characteristic for irradiated alkanes in the absorbing condition was observed. With increase of temperature of registration narrowing lines and improved sanction connected to recombination processes of radicals was observed. With increase of a hydration of a surface the redistribution and reduction of intensity separate component of a spectrum was observed. It specifies formation and stabilization bonding of radicals at smaller filling of a surface borosilicate. To reveal structure of radiolysis products IR spectra of desorbed from a borosilicate surface gas products were received at 333 K. In the field of low-frequency deformation of fluctuations CH2-groups the doublet strip with maxima was observed at 790 cm-1 and 770 cm-1 which is referred to low-molecular of radiolysis products

  1. First principles process-product models for vitrification of nuclear waste: Relationship of glass composition to glass viscosity, resistivity, liquidus temperature, and durability

    International Nuclear Information System (INIS)

    Borosilicate glasses will be used in the USA and in Europe to immobilize radioactive high level liquid wastes (HLLW) for ultimate geologic disposal. Process and product quality models based on glass composition simplify the fabrication of the borosilicate glass while ensuring glass processability and quality. The process model for glass viscosity is based on a relationship between the glass composition and its structural polymerization. The relationship between glass viscosity and electrical resistivity is also shown to relate to glass polymerization. The process model for glass liquidus temperature calculates the solubility of the liquidus phases based on the free energies of formation of the precipitating species. The durability product quality model is based on the calculation of the thermodynamic hydration free energy from the glass composition

  2. 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.

  3. 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)

  4. 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

  5. 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

  6. Development of a glass matrix for vitrification of sulphate bearing high level radioactive liquid waste

    International Nuclear Information System (INIS)

    High level radioactive liquid waste (HLW) is generated during reprocessing of spent nuclear fuel. In the earlier reprocessing flow sheet ferrous sulphamate has been used for valancy adjustment of Pu from IV to III for effective separation. This has resulted in generation of HLW containing significance amount of sulphate. Internationally borosilicate glass matrix has been adopted for vitrification of HLW. The first Indian vitrification facility at Waste Immobilislition Plant (WIP), Tarapur a five component borosilicate matrix (SiO2 :B2O3 :Na2O : MnO : TiO2) has been used for vitrification of waste. However at Trombay HLW contain significant amount of sulphate which is not compatible with standard borosilicate formulation. Extensive R and D efforts were made to develop a glass formulation which can accommodate sulphate and other constituents of HLW e.g., U, Al, Ca, etc. This report deals with development work of a glass formulations for immobilization of sulphate bearing waste. Different glass formulations were studied to evaluate the compatibility with respect to sulphate and other constituents as mentioned above. This includes sodium, lead and barium borosilicate glass matrices. Problems encountered in different glass matrices for containment of sulphate have also been addressed. A glass formulation based on barium borosilicate was found to be effective and compatible for sulphate bearing high level waste. (author)

  7. Glasses and ceramics for immobilisation of radioactive wastes for disposal

    International Nuclear Information System (INIS)

    The U.K. Research Programme on Radioactive Waste Management includes the development of processes for the conversion of high level liquid reprocessing wastes from thermal and fast reactors to borosilicate glasses. The properties of these glasses and their behaviour under storage and disposal conditions have been examined. Methods for immobilising activity from other wastes by conversion to glass or ceramic forms is described. The U.K. philosophy of final solutions to waste management and disposal is presented. (author)

  8. 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...

  9. Glasses and nuclear waste vitrification

    International Nuclear Information System (INIS)

    Glass is an amorphous solid material which behaves like an isotropic crystal. Atomic structure of glass lacks long-range order but possesses short and most probably medium range order. Compared to crystalline materials of the same composition glasses are metastable materials however crystallisation processes are kinetically impeded within times which typically exceed the age of universe. The physical and chemical durability of glasses combined with their high tolerance to compositional changes makes glasses irreplaceable when hazardous waste needs immobilisation for safe long-term storage, transportation and consequent disposal. Immobilisation of radioactive waste in glassy materials using vitrification has been used successfully for several decades. Nuclear waste vitrification is attractive because of its flexibility, the large number of elements which can be incorporated in the glass, its high corrosion durability and the reduced volume of the resulting wasteform. Vitrification involves melting of waste materials with glass-forming additives so that the final vitreous product incorporates the waste contaminants in its macro- and micro-structure. Hazardous waste constituents are immobilised either by direct incorporation into the glass structure or by encapsulation when the final glassy material can be in form of a glass composite material. Both borosilicate and phosphate glasses are currently used to immobilise nuclear wastes. In addition to relatively homogeneous glasses novel glass composite materials are used to immobilise problematic waste streams. (author)

  10. Glasses and Glass-Ceramic Components from Inorganic Waste and Novel Processing

    OpenAIRE

    Ponsot, Inès

    2015-01-01

    Thanks to European environmental rules and regulations establishment, waste recycling has become a more and more relevant problematic. For manufacturing plants, especially those producing hazardous wastes, expenses linked to waste production have drastically increased over the last decades. In the proposed work, various hazardous and non-hazardous wastes, among: soda-lime and borosilicate glass cullet, cathode ray tubes glass, exhausted lime from fume abatement systems residues, sludge and sl...

  11. Solubility of actinide surrogates in nuclear glasses

    International Nuclear Information System (INIS)

    This paper discusses the results of a study of actinide surrogates in a nuclear borosilicate glass to understand the effect of processing conditions (temperature and oxidizing versus reducing conditions) on the solubility limits of these elements. The incorporation of cerium oxide, hafnium oxide, and neodymium oxide in this borosilicate glass was investigated. Cerium is a possible surrogate for tetravalent and trivalent actinides, hafnium for tetravalent actinides, and neodymium for trivalent actinides. The material homogeneity was studied by optical, scanning electron microscopy. Cerium LIII XANES spectroscopy showed that the Ce3+/Cetotal ratio increased from about 0.5 to 0.9 as the processing temperature increased from 1100 to 1400 deg. C. Cerium LIII XANES spectroscopy also confirmed that the increased Ce solubility in glasses melted under reducing conditions was due to complete reduction of all the cerium in the glass. The most significant results pointed out in the current study are that the solubility limits of the actinide surrogates increases with the processing temperature and that Ce3+ is shown to be more soluble than Ce4+ in this borosilicate glass

  12. 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.

  13. 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.

  14. Ultraflat-top midinfrared coherent broadband supercontinuum using all normal As2S5-borosilicate hybrid photonic crystal fiber

    Science.gov (United States)

    Ben Salem, Amine; Diouf, Mbaye; Cherif, Rim; Wague, Ahmadou; Zghal, Mourad

    2016-06-01

    We report more than two octave spanning mid-IR flat-top supercontinuum (SC) generation using all normal As2S5-borosilicate hybrid photonic crystal fiber. Our design is based on a chalcogenide As2S5 photonic crystal fiber (PCF), where the first ring composed of six air holes is made by borosilicate glass. By injecting 50-fs pulses with 1.6 nJ energy at 2.5 μm in the all normal dispersion (ANDi) regime, a flat-top broadband SC extending from 1 to 5 μm with high-spectral flatness of 8 dB is obtained in only 4-mm fiber length. To the best of our knowledge, we present the broadest flat mid-IR spectrum generated in the ANDi regime of an optical fiber. The self-phase modulation and the optical wave breaking are identified as the main broadening mechanisms. The obtained broadband light source can be potentially used in the field of spectroscopy and in high-resolution optical coherent tomography owing to the high-spectral SC flatness generated by our designed fiber.

  15. Contributions of vitreous natural analogs to the investigation of long-term nuclear glass behavior

    International Nuclear Information System (INIS)

    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-1. As the reaction progresses, the alteration rate drops by over four orders of magnitude from the initial rate r0, 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)

  16. 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.

  17. 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.

  18. Property Data for Simulated Americium/Curium Glasses

    International Nuclear Information System (INIS)

    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 Ln2O3 and the concentrations of Ln2O3, SiO2, B2O3, Al2O3, 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 (η) as a function of temperature (T) and the liquidus temperature (TL) of Phase II test glasses

  19. 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

  20. Effects of beta/gamma radiation on nuclear waste glasses

    Energy Technology Data Exchange (ETDEWEB)

    Weber, W.J. [Pacific Northwest National Lab., Richland, WA (United States)

    1997-07-01

    A key challenge in the disposal of high-level nuclear waste (HLW) in glass waste forms is the development of models of long-term performance based on sound scientific understanding of relevant phenomena. Beta decay of fission products is one source of radiation that can impact the performance of HLW glasses through the interactions of the emitted {beta}-particles and g-rays with the atoms in the glass by ionization processes. Fused silica, alkali silicate glasses, alkali borosilicate glasses, and nuclear waste glasses are all susceptible to radiation effects from ionization. In simple glasses, defects (e.g., non-bridging oxygen and interstitial molecular oxygen) are observed experimentally. In more complex glasses, including nuclear waste glasses, similar defects are expected, and changes in microstructure, such as the formation of bubbles, have been reported. The current state of knowledge regarding the effects of {beta}/{gamma} radiation on the properties and microstructure of nuclear waste glasses are reviewed. (author)

  1. Effects of beta/gamma radiation on nuclear waste glasses

    International Nuclear Information System (INIS)

    A key challenge in the disposal of high-level nuclear waste (HLW) in glass waste forms is the development of models of long-term performance based on sound scientific understanding of relevant phenomena. Beta decay of fission products is one source of radiation that can impact the performance of HLW glasses through the interactions of the emitted β-particles and g-rays with the atoms in the glass by ionization processes. Fused silica, alkali silicate glasses, alkali borosilicate glasses, and nuclear waste glasses are all susceptible to radiation effects from ionization. In simple glasses, defects (e.g., non-bridging oxygen and interstitial molecular oxygen) are observed experimentally. In more complex glasses, including nuclear waste glasses, similar defects are expected, and changes in microstructure, such as the formation of bubbles, have been reported. The current state of knowledge regarding the effects of β/γ radiation on the properties and microstructure of nuclear waste glasses are reviewed. (author)

  2. 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.

  3. Synthesis and characterization of acidic mesoporous borosilicate thin films.

    Science.gov (United States)

    Xiu, Tongping; Liu, Qian; Wang, Jiacheng

    2009-02-01

    Work on the synthesis and characterization of acidic wormhole-like ordered mesoporous borosilicate thin films (MBSTFs) on silicon wafers is described in this paper. The MBSTFs coated by the dip-coating method were prepared through an evaporation-induced self-assembly (EISA) process using nonionic block copolymers as structure-directing agents. Fourier transform infrared (FT-IR) spectroscopy confirmed the formation of borosiloxane bonds (Si-O-B). High-resolution transmission electron microscopy (HRTEM) and N2 sorption evidenced a wormhole-like mesoporous structure in the MBSTFs obtained. Scanning electron microscopy (SEM) images of the cross sections and surfaces of the samples showed that MBSTFs on silicon wafers were continuous, homogeneous and did not crack. The acidic properties of the MBSTFs were characterized by FT-IR spectra of chemisorbed pyridine. The MBSTFs thus prepared may find their future applications in many fields including chemical sensors, catalysis, optical coating, molecule separation, etc. PMID:19441565

  4. 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.

  5. 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

  6. Long term corrosion of glasses in salt brines

    OpenAIRE

    Roggendorf, Hans; Schmidt, Helmut K.

    1989-01-01

    Borosilicate glasses are supposed to be a suitable matrix for the fixation of calcined radioactive wastes. For the safety assessment of the disposal of these glasses in geological formations like carnallite or rock salt, their chemical durability in saturated salt brines has been investigated. Temperatures up to 200° C, pressures up to 130 bar, and corrosion times up to 5 years were applied. Special attention was given to the long term corrosion which is mainly characterized by the saturation...

  7. 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

  8. Mechanical Strength and Broadband Transparency Improvement of Glass Wafers via Surface Nanostructures

    Science.gov (United States)

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

    2016-01-01

    In this study, we mechanically strengthened a borosilicate glass wafer by doubling its bending strength and simultaneously enhancing its transparency using surface nanostructures for different applications including sensors, displays and panels. A fabrication method that combines dry and wet etching is used for surface nanostructure fabrication. Specifically, we improved the bending strength of plain borosilicate glass by 96% using these surface nanostructures on both sides. Besides bending strength improvement, a limited optical transmittance enhancement of 3% was also observed in the visible light wavelength region (400–800 nm). Both strength and transparency were improved by using surface nanostructures of 500 nm depth on both sides of the borosilicate glass without affecting its bulk properties or the glass manufacturing process. Moreover, we observed comparatively smaller fragments during the breaking of the nanostructured glass, which is indicative of strengthening. The range for the nanostructure depth is defined for different applications with which improvements of the strength and transparency of borosilicate glass substrate are obtained. PMID:27322276

  9. Mechanical Strength and Broadband Transparency Improvement of Glass Wafers via Surface Nanostructures.

    Science.gov (United States)

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

    2016-01-01

    In this study, we mechanically strengthened a borosilicate glass wafer by doubling its bending strength and simultaneously enhancing its transparency using surface nanostructures for different applications including sensors, displays and panels. A fabrication method that combines dry and wet etching is used for surface nanostructure fabrication. Specifically, we improved the bending strength of plain borosilicate glass by 96% using these surface nanostructures on both sides. Besides bending strength improvement, a limited optical transmittance enhancement of 3% was also observed in the visible light wavelength region (400-800 nm). Both strength and transparency were improved by using surface nanostructures of 500 nm depth on both sides of the borosilicate glass without affecting its bulk properties or the glass manufacturing process. Moreover, we observed comparatively smaller fragments during the breaking of the nanostructured glass, which is indicative of strengthening. The range for the nanostructure depth is defined for different applications with which improvements of the strength and transparency of borosilicate glass substrate are obtained. PMID:27322276

  10. The role of nuclear analytical techniques in the study of aqueous corrosion of glasses

    International Nuclear Information System (INIS)

    Direct observation of resonant nuclear reactions, backscattering spectrometry and X ray microanalysis with a nuclear microprobe were used to determine elementary depth profiles in the near surface region of leached glasses. Some computing programs required to interpretate the analytical information detected were built. Experimental conditions to characterize glass samples without secondary effects were defined; and the influence of some leaching parameters was studied to describe the first stages of aqueous corrosion of borosilicate glasses

  11. The Silicon-To-Silicon Anodic Bonding Using Sputter Deposited Intermediate Glass Layer

    OpenAIRE

    TIWARI, R; Chandra, S.

    2011-01-01

    Glass-to-silicon anodic bonding is an attractive process for packaging of microelectronics devices and Micro-electro-mechanical Systems (MEMS). Silicon to silicon anodic bonding can also be accomplished by incorporating an intermediate glass layer. In the present work, silicon-to-silicon anodic bonding has been studied with an intermediate borosilicate glass layer deposited by RF magnetron sputtering process. The bonding was carried out at low dc voltage of about 48 V at 400 °C. Surface rough...

  12. UK program: glasses and ceramics for immobilization of radioactive wastes for disposal

    International Nuclear Information System (INIS)

    The UK Research Program on Radioactive Waste Management includes the development of processes for the conversion of high-level-liquid-reprocessing wastes from thermal and fast reactors to borosilicate glasses. The properties of these glasses and their behavior under storage and disposal conditions have been examined. Methods for immobilizing activity from other wastes by conversion to glass or ceramic forms are described. The UK philosophy of final solutions to waste management and disposal is presented

  13. The relationship between glass viscosity and composition: A first principles model for vitrification of nuclear waste

    International Nuclear Information System (INIS)

    The Defense Waste Processing Facility will incorporate high-level liquid waste into borosilicate glass for stabilization and permanent disposal in a geologic repository. The viscosity of the melt determines the rate of melting of the raw feed, the rate of gas bubble release due to foaming and fining, the rate of homogenization, and thus, the quality of the glass produced. The viscosity of the glass is in turn, a function of both glass composition and temperature. A model describing the viscosity dependence on composition, temperature, and glass structure (bonding) has been derived for glasses ranging from pure frits to frit plus 35 wt % simulated waste. 17 refs., 37 figs

  14. Challenges in commercial manufacture of radiation shielding glasses

    International Nuclear Information System (INIS)

    Radioactive hot-cells employ Radiation Shielding Windows (RSWs), assembled from specialty glasses, developed exclusively for nuclear industry. RSWs serve the twin purpose of direct viewing and shielding protection to the operator and use various types of radiation resistant and optically compatible glasses, such as low-density borosilicate glass; medium-density glass with up to 45% Lead and high-density glass with over 70% lead. Some glasses are Ceria-doped for enhancing their resistance threshold to radiation browning. A clear view of future requirement, capital and environmental costs could be the driving force towards bringing about changes in melting practices, encourage melting development, and enhancing collaboration. With DAE and CGCRI working in tandem, production of the entire range of RSW glasses by an Indian glass industry participant may no longer be a distant dream

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

    International Nuclear Information System (INIS)

    This work is a continuation of a previous one performed in vitrification of uranium silicide in borosilicate and iron-silicate glasses, by sintering.We present the results obtained with an iron-phosphate glass developed at our laboratory and we compare this results with those obtained with the above mentioned glasses. The main objective was to develop a method as simple as possible, so as to get a monolithic glass block with the appropriate properties to be disposed in a deep geological repository.The thermal transformation of the uranium silicide was characterized by DTA/TG analysis and X-ray diffraction.We determined the evolution of the crystalline phases and the change in weight.Calcined uranium silicide was mixed with natural U3O8, the amount of U3O8 was calculated to simulate an isotopic dilution of 4%.This material was mixed with powdered iron-phosphate glass (in wt.%: 64,9 P2O5; 22,7 Fe2O3; 8,1 Al2O3; 4,3 Na2O) in different proportions (in wt%): 7%, 10% y 15%.The powders were pressed and sintered at temperatures between 585 y 670 °C. Samples of the sintered pellet were prepared for the lixiviation tests (MCC-1P: monolithic samples; deionised water; 90° C; 7, 14 and 28 days).The samples showed a quite good durability (0,6 g.m-2.day-1), similar to borosilicate glasses.The microstructure of the glass samples showed that the uranium particles are much better integrated to the glass matrix in the iron-phosphate glasses than in the borosilicate or iron-silicate glasses.We can conclude that the sintered product obtained could be a good alternative for the immobilization of nuclear wastes with high content of uranium, as the ones arising from the conditioning of research reactors spent fuels

  16. The generalized Tailor Problem

    NARCIS (Netherlands)

    Roerdink, J.B.T.M.; Maragos, P; Schafer, RW; Butt, MA

    1996-01-01

    The so-called 'Tailor Problem' concerns putting a number of sets within another set by translation, such that the translated sets do not overlap. In this paper we consider a generalization of this problem in which also rotations of the sets are allowed.

  17. 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.

  18. 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.

  19. 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.

  20. Defense Waste Processing Facility (DWPF) startup test program: Glass characterization

    International Nuclear Information System (INIS)

    Liquid high-level nuclear waste will be immobilized at the Savannah River Site (SRS) by vitrification in borosilicate glass. The glass will be processed in the Defense Waste Processing Facility (DWPF) and poured into stainless steel canisters for eventual geologic disposal. Six simulated glass compositions will be processed in the DWPF during initial startup. The glass in 86 of the first 106 full sized canisters will be sampled and characterized. Extensive glass characterization will determine the following: (1) sampling frequency for radioactive operation, (2) verification of the compositionally dependent process-product models, (3) verification of melter mixing, (4) representativeness of the glass from the canister throat sampler, and (5) homogeneity of the canister glass

  1. Glasses for nuclear waste immobilization

    International Nuclear Information System (INIS)

    Vitrification of nuclear wastes is attractive because of its flexibility, the large number of elements which can be incorporated in the glass, its high corrosion durability and the reduced volume of the resulting waste form. Vitrification is a mature technology and has been used for high level nuclear waste (HLW) immobilisation for more than 40 years in France, Germany and Belgium, Russia, UK, Japan and the USA. Vitrification involves melting of waste materials with glass-forming additives so that the final vitreous product incorporates the waste contaminants in its macro- and micro-structure. Hazardous waste constituents are immobilised either by direct incorporation into the glass structure or by encapsulation when the final glassy material can be in form of a glass composite material (GCM). Both borosilicate and phosphate glasses are currently used to immobilise nuclear wastes, moreover in addition to relatively homogeneous glasses novel GCM are used to immobilise problematic waste streams. The spectrum of wastes which are currently vitrified increases from HLW to low and intermediate wastes (LILW) such as legacy wastes in Hanford, USA and nuclear power plant operational wastes in Russia and Korea. (authors)

  2. Comparison of costs for solidification of high-level radioactive waste solutions: glass monoliths vs metal matrices

    International Nuclear Information System (INIS)

    A comparative economic analysis was made of four solidification processes for liquid high-level radioactive waste. Two processes produced borosilicate glass monoliths and two others produced metal matrix composites of lead and borosilicate glass beads and lead and supercalcine pellets. Within the uncertainties of the cost (1979 dollars) estimates, the cost of the four processes was about the same, with the major cost component being the cost of the primary building structure. Equipment costs and operating and maintenance costs formed only a small portion of the building structure costs for all processes

  3. Reference commercial high-level waste glass and canister definition

    International Nuclear Information System (INIS)

    This report presents technical data and performance characteristics of a high-level waste glass and canister intended for use in the design of a complete waste encapsulation package suitable for disposal in a geologic repository. The borosilicate glass contained in the stainless steel canister represents the probable type of high-level waste product that will be produced in a commercial nuclear-fuel reprocessing plant. Development history is summarized for high-level liquid waste compositions, waste glass composition and characteristics, and canister design. The decay histories of the fission products and actinides (plus daughters) calculated by the ORIGEN-II code are presented

  4. Graphite fiber reinforced glass matrix composites for aerospace applications

    Science.gov (United States)

    Prewo, K. M.; Bacon, J. F.; Dicus, D. L.

    1979-01-01

    The graphite fiber reinforced glass matrix composite system is described. Although this composite is not yet a mature material, it possesses low density, attractive mechanical properties at elevated temperatures, and good environmental stability. Properties are reported for a borosilicate glass matrix unidirectionally reinforced with 60 volume percent HMS graphite fiber. The flexural strength and fatigue characteristics at room and elevated temperature, resistance to thermal cycling and continuous high temperature oxidation, and thermal expansion characteristics of the composite are reported. The properties of this new composite are compared to those of advanced resin and metal matrix composites showing that graphite fiber reinforced glass matrix composites are attractive for aerospace applications.

  5. Mechanisms of dissolution of radioactive waste storage glasses and cesium migration from a granite repository

    International Nuclear Information System (INIS)

    Experimental and theoretical data are used to compare the effect of three possible leach mechanisms for borosilicate glass waste buried in a granite host-rock on the release and subsequent migration of 135Cs. Protracted release episodes and variations of up to an order of magnitude in groundwater transport times and five orders in output concentrations are possible. 4 figures

  6. 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.

  7. 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.

  8. Tailored reflectors for illumination.

    Science.gov (United States)

    Jenkins, D; Winston, R

    1996-04-01

    We report on tailored reflector design methods that allow the placement of general illumination patterns onto a target plane. The use of a new integral design method based on the edge-ray principle of nonimaging optics gives much more compact reflector shapes by eliminating the need for a gap between the source and the reflector profile. In addition, the reflectivity of the reflector is incorporated as a design parameter. We show the performance of design for constant irradiance on a distant plane, and we show how a leading-edge-ray method may be used to achieve general illumination patterns on nearby targets. PMID:21085288

  9. Preparation of bioactive glasses with controllable degradation behavior and their bioactive characterization

    Institute of Scientific and Technical Information of China (English)

    YAO AiHua; WANG DePing; FU Qiang; HUANG WenHai; Mohamed N. RAHAMAN

    2007-01-01

    Bioactive glasses and ceramics have been widely investigated for bone repair because of their excellent bioactive characteristics. However, these biomaterials undergo incomplete conversion into a bone-like material, which severely limits their biomedical application. In this paper, borosilicate bioactive glasses were prepared by traditional melting process. The results showed that borosilicate glasses possessed high biocompatibility and bioactivity. In addition, when immersed in a 0.02 mol/L K2HPO4 solution, particles of a borate glass were fully converted to HA. The desirable conversion rate to HA may be achieved through the adjustment of the B2O3/SiO2 ratio. The results of XRD and FTIR analysis indicated that the degradation product was carbonate-substituted hydroxyapatite, which was similar to the inorganic component of bone.

  10. High-Temperature Viscosity Of Commercial Glasses

    Energy Technology Data Exchange (ETDEWEB)

    Hrma, Pavel R; See, Clem A; Lam, Oanh P; Minister, Kevin B

    2005-01-01

    Viscosity was measured for six types of commercial glasses: low-expansion-borosilicate glasses, E glasses, fiberglass wool glasses, TV panel glasses, container glasses, and float glasses. Viscosity data were obtained with rotating spindle viscometers within the temperature range between 900°C and 1550°C; the viscosity varied from 1 Pa∙s to 750 Pa∙s. Arrhenius coefficients were calculated for individual glasses and linear models were applied to relate them to the mass fractions of 11 major components (SiO2, CaO, Na2O, Al2O3, B2O3, BaO, SrO, K2O, MgO, PbO, and ZrO2) and 12 minor components (Fe2O3, ZnO, Li2O, TiO2, CeO2, F, Sb2O3, Cr2O3, As2O3, MnO2, SO3, and Co3O4). The models are recommended for glasses containing 42 to 84 mass% SiO2 to estimate viscosities or temperatures at a constant viscosity for melts within both the temperature range from 1100°C to 1550°C and viscosity range from 10 to 400 Pas.

  11. Decontamination of DWPF canisters by glass frit blasting

    International Nuclear Information System (INIS)

    High-level radioactive waste at the Savannah River Plant will be incorporated in borosilicate glass for permanent disposal. The waste glass will be encapsulated in a 304L stainless steel canister. During the filling operation the outside of the canister will become contaminated. This contamination must be reduced to an accepable level before the canister leaves the Defense Waste Processing Facility (DWPF). Tests with contaminated coupons have demonstrated that this decontamination can be accomplished by blasting the surface with glass frit. The contaminated glass frit byproduct of this operation is used as a feedstock for the waste glass process, so no secondary waste is created. Three blasting techniques, using glass frit as the blasting medium, were evaluated. Air-injected slurry blasting was the most promising and was chosen for further development. The optimum parametric values for this process were determined in tests using coupon weight loss as the output parameter. 1 reference, 13 figures, 3 tables

  12. 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

  13. 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)

  14. 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.

  15. 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. PMID:24261406

  16. 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.

  17. 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.

  18. Evolution of mechanical properties of silicate glasses: Impact of the chemical composition and effects of irradiation

    International Nuclear Information System (INIS)

    This thesis examines: (1) how the chemical composition changes the hardness, toughness, and stress corrosion cracking behavior in model pristine and (2) how external irradiation impact these properties. It is to be incorporated in the context of the storage of nuclear waste in borosilicate glass matrix, the structural integrity of which should be assessed. Eight simplified borosilicate glasses made of 3 oxides with modulated proportions (SiO2-B2O3-Na2O (SBN) have been selected and their hardness, toughness, and stress corrosion cracking behavior have been characterized prior and after irradiation. The comparative study of the non-irradiated SBN glasses provides the role played by the chemical composition. The sodium content is found to be the key parameter: As it increases, the glass plasticity increases, leading to changes in the mechanical response to strain. Hardness (Hv) and toughness (Kc) decrease since the flow under indenter increases. The analysis of the stress corrosion behavior evidences a clear shift of the SCC curves linked also to the glass plasticity. Four of the 8 simplified SBN glass systems highlight the influence of electron, light and heavy ions irradiations on the mechanical properties. Once again, the sodium content is a key parameter. It is found to inhibit the glass modification: Glasses with high sodium content are more stable. Ions irradiations highlight the predominant role of nuclear interaction in changing the glass properties. Finally, electronic interaction induced by helium and electron irradiation does not lead to the same structural/mechanical glasses variations. (author)

  19. Atomic layer deposition of alternative glass microchannel plates

    International Nuclear Information System (INIS)

    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 cm2). 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−2 s−1), and low gain variation (±5%)

  20. Investigation of crystallization in glasses containing fission products

    International Nuclear Information System (INIS)

    Five potential solidification products for high-level waste (four borosilicate glasses and one celsian glass ceramic) have been investigated in terms of crystallization. In all glasses and in the glass ceramic, crystallization, and recrystallization, respectively, were observed by heating above 7730K, however, at very different periods of time (0.1d greater than or equal to 100d). The noble metals precipitated into various phases. Crystal growth proceeded at the phase boundary glass-noble metal. In all products rare earth phases crystallized. Silicate phases rarely formed. The leach resistance (by the grain titration and Soxhlet tests) decreased after heat treatment in all cases. The changes were found to be within one order of magnitude for all products. 2 figures, 4 tables

  1. Iron Phosphate Glasses: An Alternative for Vitrifying Certain Nuclear Wastes

    International Nuclear Information System (INIS)

    Vitrification of nuclear waste in a glass is currently the preferred process for waste disposal. DOE currently approves only borosilicate (BS) type glasses for such purposes. However, many nuclear wastes, presently awaiting disposal, have complex and diverse chemical compositions, and often contain components that are poorly soluble or chemically incompatible in BS glasses. Such problematic wastes can be pre-processed and/or diluted to compensate for their incompatibility with a BS glass matrix, but both of these solutions increases the wasteform volume and the overall cost for vitrification. Direct vitrification using alternative glasses that utilize the major components already present in the waste is preferable, since it avoids pre-treating or diluting the waste, and, thus, minimizes the wasteform volume and overall cost

  2. 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.

  3. Critical review of glass performance modeling

    International Nuclear Information System (INIS)

    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

  4. 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.)

  5. Fiber reinforced glasses and glass-ceramics for high performance applications

    Science.gov (United States)

    Prewo, K. M.; Brennan, J. J.; Layden, G. K.

    1986-01-01

    The development of fiber reinforced glass and glass-ceramic matrix composites is described. The general concepts involved in composite fabrication and resultant composite properties are given for a broad range of fiber and matrix combinations. It is shown that composite materials can be tailored to achieve high levels of toughness, strength, and elastic stiffness, as well as wear resistance and dimensional stability.

  6. 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.

  7. 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.

  8. Engineering Property Prediction Tools for Tailored Polymer Composite Structures

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Ba Nghiep; Foss, Peter; Wyzgoski, Michael; Trantina, Gerry; Kunc, Vlastimil; Schutte, Carol; Smith, Mark T.

    2009-12-23

    This report summarizes our FY 2009 research activities for the project titled:"Engineering Property Prediction Tools for Tailored Polymer Composite Structures." These activities include (i) the completion of the development of a fiber length attrition model for injection-molded long-fiber thermoplastics (LFTs), (ii) development of the a fatigue damage model for LFTs and its implementation in ABAQUS, (iii) development of an impact damage model for LFTs and its implementation in ABAQUS, (iv) development of characterization methods for fatigue testing, (v) characterization of creep and fatigue responses of glass-fiber/polyamide (PA6,6) and glass-fiber/polypropylene (PP), (vi) characterization of fiber length distribution along the flow length of glass/PA6,6 and glass-fiber/PP, and (vii) characterization of impact responses of glass-fiber/PA6,6. The fiber length attrition model accurately captures the fiber length distribution along the flow length of the studied glass-fiber/PP material. The fatigue damage model is able to predict the S-N and stiffness reduction data which are valuable to the fatigue design of LFTs. The impact damage model correctly captures damage accumulation observed in experiments of glass-fiber/PA6,6 plaques.Further work includes validations of these models for representative LFT materials and a complex LFT part.

  9. Performance evaluation of vitrified waste product based on barium-borosilicate matrix deployed for vitrification of sulphate bearing high level radioactive liquid waste

    International Nuclear Information System (INIS)

    Aqueous waste of various categories (viz., low, intermediate and high level depending on the concentration of radionuclides) is generated at different stages of the nuclear fuel cycle. Most of the radioactivity generated in entire nuclear fuel cycle is concentrated in high level radioactive liquid waste (HLW). Since the radioactivity of the waste is to be isolated from the human-environment for extended period of time, a three stage approach has been adopted for management of HLW. This involves (i) immobilization of waste oxides in stable and inert solid matrices, (ii) interim retrievable storage of conditioned waste packages under cooling and surveillance and (iii) deep underground disposal in suitable geological formulations. Composition of HLW depends on various factors like type of fuel and its cladding, off reactor cooling, reprocessing flow sheet etc. Compositional changes in HLW necessitate modification in glass formulations, so as to get the conditioned product of desired characteristics. This report describes the experimental studies and results obtained for performance evaluation of the vitrified waste product made from barium borosilicate glass matrix accommodating sulphate bearing chemically simulated HLW. Product characteristics like chemical durability, homogeneity, phase separation, thermal conductivity, impact strength etc have been evaluated and discussed in the report. (author)

  10. 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.

  11. 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.

  12. NMR Studies of Permanent Compression in Oxide Glasses

    DEFF Research Database (Denmark)

    Youngman, Randall E.; Svenson, Mouritz Nolsøe; Mauro, John C.;

    Pressure-induced structural rearrangement in oxide glasses is manifested by modification of both short- and intermediate-range structures, including changes to the local coordination numbers of network forming cations and alteration of the modifier environment. NMR spectroscopy is an especially...... of the network modifying sodium atoms, will be discussed. Such changes in network structure aid in understanding the pressure-induced properties of these glasses, such as density, elastic moduli, hardness and crack resistance....... useful tool for examining these changes in network structure, especially for boron-containing glasses, which are particularly sensitive to permanent compression. Here we describe studies based on hot isostatic compression of several different borate and borosilicate glasses, where changes in short...

  13. 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.

  14. 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.

  15. 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.

  16. DWPF glass transition temperatures: What they are and why they are important

    Energy Technology Data Exchange (ETDEWEB)

    Marra, S.L.; Jantzen, C.M.; Ramsey, A.A.

    1991-12-31

    The Defense Waste Processing Facility (DWPF) at the Savannah River Site will immobilize high-level radioactive liquid waste in borosilicate glass. The glass will be poured into stainless steel canisters for eventual disposal in a geologic repository. The Department of Energy has defined a set of requirements for the DWPF canistered waste form which must be met in order to assure compatibility with, and acceptance by, the repository. These requirements are the Waste Acceptance Preliminary Specifications (WAPS). The WAPS require DWPF to report glass transition temperatures for the projected range of compositions. This information will be used by the repository to establish waste package design limits.

  17. DWPF glass transition temperatures: What they are and why they are important

    Energy Technology Data Exchange (ETDEWEB)

    Marra, S.L.; Jantzen, C.M.; Ramsey, A.A.

    1991-01-01

    The Defense Waste Processing Facility (DWPF) at the Savannah River Site will immobilize high-level radioactive liquid waste in borosilicate glass. The glass will be poured into stainless steel canisters for eventual disposal in a geologic repository. The Department of Energy has defined a set of requirements for the DWPF canistered waste form which must be met in order to assure compatibility with, and acceptance by, the repository. These requirements are the Waste Acceptance Preliminary Specifications (WAPS). The WAPS require DWPF to report glass transition temperatures for the projected range of compositions. This information will be used by the repository to establish waste package design limits.

  18. 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.

  19. 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.

  20. Reaction of glass during gamma irradiation in a saturated tuff environment. Part 1. SRL 165 glass

    International Nuclear Information System (INIS)

    The influence of gamma irradiation on the reaction of actinide-doped borosilicate glass (SRL 165) in a saturated tuff environment has been studied in a series of tests lasting up to 56 days. The following conclusions were reached. The reaction of, and subsequent actinide release from, the glass depends on the dynamic interaction between radiolysis effects, which cause the solution pH to become more acidic; glass reaction, which drives the pH more basic; and test component interactions that may extract glass components from solution. The use of large gamma irradiation dose rates to accelerate reactions that may occur in an actual repository radiation field may affect this dynamic balance by unduly influencing the mechanism of the glass-water reaction. Comparisons between the present results and data obtained by reacting similar glasses using MCC-1 and NNWSI rock cup procedures indicate that the irradiation conditions used in the present experiments do not dramatically influence the reaction rate of the glass. 8 figs., 9 tabs

  1. Development and radiation stability of glasses for highly radioactive wastes

    International Nuclear Information System (INIS)

    The variation of formation temperature, crystallizing behaviour and leach resistance with composition changes for sodium-lithium borosilicate glasses suitable for vitrifying Magnox waste are discussed. Viscosities have been measured between 400 and 10500C. The principal crystal phases which occur have been identified as magnesium silicate, magnesium borate and ceria. The leach rate of polished discs in pure water at 1000C does not decrease with time if account is taken of the fragile siliceous layer that is observed to occur. The effect of 100 years' equivalent α- and β-irradiation on glass properties is discussed. Stored energy release experiments demonstrated that energy is released over a wide temperature range so that it cannot be triggered catastrophically. Temperatures required to release energy are dependent upon the original storage temperature. Helium release is by Fick's diffusion law up to at least 30% of the total inventory, with diffusion coefficients similar to those for comparable borosilicate glasses. Leach rates were not measurably affected by α-radiation. β-radiation in a Van de Graaff accelerator did not change physical properties, but irradiation in an electron microscope caused minute bubbles in lithium-containing glasses above 2000C. (author)

  2. 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.

  3. Radiation effects in glass and glass-ceramic waste forms for the immobilization of CANDU UO2 fuel reprocessing waste

    International Nuclear Information System (INIS)

    AECL has investigated three waste forms for the immobilization of high-level liquid wastes that would arise if used CANDU fuels were reprocessed at some time in the future to remove fissile materials for the fabrication of new power reactor fuel. These waste forms are borosilicate glasses, aluminosilicate glasses and titanosilicate glass-ceramics. This report discusses the potential effects of alpha, beta and gamma radiation on the releases of radionuclides from these waste forms as a result of aqueous corrosion by groundwaters that would be present in an underground waste disposal vault. The report discusses solid-state damage caused by radiation-induced atomic displacements in the waste forms as well as irradiation of groundwater solutions (radiolysis), and their potential effects on waste-form corrosion and radionuclide release. The current literature on radiation effects on borosilicate glasses and in ceramics is briefly reviewed, as are potential radiation effects on specialized waste forms for the immobilization of 129I, 85Kr and 14C. (author). 104 refs., 9 tabs., 5 figs

  4. Annual progress report to Battelle Pacific Northwest National Laboratories on prediction of phase separation of simulated nuclear waste glasses

    International Nuclear Information System (INIS)

    The objective of this research is to predict the immiscibility boundaries of multi-component borosilicate glasses, on which many nuclear waste glass compositions are based. The method used is similar to the prediction method of immiscibility boundaries of multi-component silicate glass systems successfully made earlier and is based upon the superposition of immiscibility boundaries of simple systems using an appropriate parameter. This method is possible because many immiscibility boundaries have similar shapes and can be scaled by a parameter. In the alkali and alkaline earth binary silicate systems, for example, the critical temperature and compositions were scaled using the Debye-Hueckel theory. In the present study on borosilicate systems, first, immiscibility boundaries of various binary alkali and alkaline borate glass systems (e.g. BaO-B2O3) were examined and their critical temperatures were evaluated in terms of Debye-Hueckel theory. The mixing effects of two alkali and alkaline-earth borate systems on the critical temperature were also explored. Next immiscibility boundaries of ternary borosilicate glasses (e.g. Na2O-SiO2-B2O3, K2O-SiO2-B2O3, Rb2O-SiO2-B2O3, and Cs2O-SiO2-B2O3) were examined. Their mixing effects are currently under investigation

  5. Morphology of altered layers of glasses

    International Nuclear Information System (INIS)

    The alteration of the french nuclear waste glass R7T7 has been studied through chemical analysis, thermo-poro-metry and X-ray scattering. Pseudo-dynamic leaching was used, with daily renewal of the leaching solution. The behavior of the R77 glass has been compared to cesium borosilicate glasses with small amounts of Ca and Zr added. As compared to these simplified compositions, the R7T7 glass has a quasi-congruent leaching of Na, B and Si and strongly retains Ca and Zr. The altered layers are very porous (porosity > 40% ). The pore size increases with time to reach a constant value that is independent of the nature of the glass but that strongly depends on the method used for leaching. The pore radii are about 4 nm in pseudo-dynamic mode and 2 nm in static conditions. X-ray scattering indicate that the pores are compact with a sharp interface. Their origin is related to the quasi-equilibrium reaction of hydrolysis redeposition of silica. (authors)

  6. Chemical durability of soda-lime-aluminosilicate glass for radioactive waste vitrification

    International Nuclear Information System (INIS)

    Vitrification has been identified as one of the most viable waste treatment alternatives for nuclear waste disposal. Currently, the most popular glass compositions being selected for vitrification are the borosilicate family of glasses. Another popular type that has been around in glass industry is the soda-lime-silicate variety, which has often been characterized as the least durable and a poor candidate for radioactive waste vitrification. By replacing the boron constituent with a cheaper substitute, such as silica, the cost of vitrification processing can be reduced. At the same time, addition of network intermediates such as Al2O3 to the glass composition increases the environmental durability of the glass. The objective of this study is to examine the ability of the soda-lime-aluminosilicate glass as an alternative vitrification tool for the disposal of radioactive waste and to investigate the sensitivity of product chemical durability to variations in composition

  7. 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).

  8. 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.

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

    International Nuclear Information System (INIS)

    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

  10. A Glass-Ceramic Waste Forms for the Immobilization of Rare Earth Oxides from the Pyroprocessing Waste salt

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Byung-Gil; Park, Hwan-Seo; Kim, Hwan-Young; Kim, In-Tae [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2008-05-15

    The fission product of rare earth (RE) oxide wastes are generates during the pyroprocess . Borosilicate glass or some ceramic materials such as monazite, apatite or sodium zirconium phosphate (NZP) have been a prospective host matrix through lots of experimental results. Silicate glasses have long been the preferred waste form for the immobilization of HLW. In immobilization of the RE oxides, the developed process on an industrial scale involves their incorporation into a glass matrix, by melting under 1200 {approx} 1300 .deg. C. Instead of the melting process, glass powder sintering is lower temperature ({approx} 900 .deg. C) required for the process which implies less demanding conditions for the equipment and a less evaporation of volatile radionuclides. This study reports the behaviors, direct vitrification of RE oxides with glass frit, glass powder sintering of REceramic with glass frit, formation of RE-apatite (or REmonazite) ceramic according to reaction temperature, and the leach resistance of the solidified waste forms.

  11. 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.

  12. The precision of product consistency tests conducted with a glass-bonded ceramic waste form

    Science.gov (United States)

    Ebert, W. L.; Lewis, M. A.; Johnson, S. G.

    2002-09-01

    The product consistency test (PCT) that is used for qualification of borosilicate high-level radioactive waste (HLW) glasses for disposal can be used for the same purpose in the qualification of the glass-bonded sodalite ceramic waste form (CWF). The CWF was developed to immobilize radioactive salt wastes generated during the electrometallurgical treatment of spent sodium-bonded nuclear fuels. An interlaboratory study was conducted to measure the precision of PCTs conducted with the CWF for comparison with the precision of PCTs conducted with HLW glasses. The six independent sets of triplicate PCT results generated in the study were used to calculate the intralaboratory and interlaboratory consistency based on the concentrations of Al, B, Na, and Si in the test solutions. The results indicate that PCTs can be conducted as precisely with the CWF as with HLW glasses. For example, the values of the reproducibility standard deviation for Al, B, Na, and Si were 1.36, 0.347, 3.40, and 2.97 mg/l for PCT with CWF. These values are within the range of values measured for borosilicate glasses, including reference HLW glasses.

  13. 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.

  14. Composition-structure-property relation of oxide glasses

    DEFF Research Database (Denmark)

    Hermansen, Christian

    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 are......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 of a...... proposed based on topological selection rules and experimentally verified. The relation between structure and properties is evaluated using topological constraint theory, which in its essence is a theory that quantifies the two intuitions of the glass scientist. The end result is a quantitative model...

  15. 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

  16. 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.

  17. Immobilization of nuclear waste: Raman Spectroscopic probing of structural changes in glass matrix

    International Nuclear Information System (INIS)

    Barium borosilicate glass used for immobilization of sulphate containing simulated high level radioactive liquid waste was prepared using conventional melt and quench method. Conventional leach test under total reflux method was used for the assessment of chemical durability of waste glass. The leaching was carried out using a conventional boiling water unit wherein powdered and screened glass sample of -16+25 BSS (850 micron) grain size was exposed to boiling distilled water for 2 years. Exposed glass specimens were subjected to Raman spectroscopic investigations to understand the structural modifications, if any, during leaching experiments. The results revealed that the leaching leads to a redistribution of bridged and non-bridged oxygen in glass. The redistribution is tentatively assigned to the possible release of structure breaking ions/atoms from the vitreous waste. (author)

  18. Spin-polarized lithium diffusion in a glass hot-vapor cell

    Science.gov (United States)

    Ishikawa, Kiyoshi

    2016-08-01

    We report diffusion coefficients of optically pumped lithium atoms in helium buffer gas. The free-induction decay and the spin-echo signals of ground-state atoms were optically detected in an external magnetic field with the addition of field gradient. Lithium hot vapor was produced in a borosilicate-glass cell at a temperature between 290 and 360°C. The simple setup using the glass cells enabled lithium atomic spectroscopy in a similar way to other alkali-metal atoms and study of the collisional properties of lithium atoms in a hot-vapor phase.

  19. Melting Hanford LAW into Iron-Phosphate Glass in a CCIM

    Energy Technology Data Exchange (ETDEWEB)

    Nick Soelberg; Sharna Rossberg

    2011-09-01

    A vitrification test has been conducted using the cold crucible induction melter (CCIM) test system at the Idaho National Laboratory. The test was conducted to demonstrate the vitrification of a Hanford low activity waste (LAW) that contains relatively large amounts of sulfate and sodium, compared to other radioactive Hanford waste streams. The high sulfate content limits the potential loading of this waste stream in conventional borosilicate glass, so this test demonstrated how this waste stream could be vitrified in an iron-phosphate glass that can tolerate higher levels of sulfate.

  20. Decontamination glass

    International Nuclear Information System (INIS)

    Glass for the decontamination of the furnace for vitrification of radioactive wastes contains 50 to 60 wt.% of waste glass, 15 to 30 wt.% of calcium oxide, 1 to 6 wt.% sodium oxide, 1 to 5 wt.% phosphorus pentoxide and 5 to 20 wt.% boron oxide. The melting furnace is flushed with the glass such that it melts in the furnace for at least 60 mins and is then poured out of the furnace. After the furnace has cooled down the settled glass spontaneously cracks and peels off the walls leaving a clean surface. The glass may be used not only for decontamination of the furnace but also for decontamination of melting crucibles and other devices contaminated with radioactive glass. (J.B.)

  1. The Fate Of Silicon During Glass Corrosion Under Alkaline Conditions: A Mechanistic And Kinetic Study With The International Simple Glass

    Energy Technology Data Exchange (ETDEWEB)

    Gin, Stephane; Jollivet, Patrick; Fournie, Maxime; Berthon, Claude; Wang, Zhaoying; Mitroshkov, Alexandre V.; Zhu, Zihua; Ryan, Joseph V.

    2015-02-01

    International Simple Glass - a six oxide borosilicate glass selected by the international nuclear glass community to improve the understanding of glass corrosion mechanisms and kinetics - was altered at 90°C in a solution initially saturated with respect to amorphous 29-SiO2. The pH90°C, was fixed at 9 at the start of the experiment and raised to 11.5 after 209 d by the addition of KOH. Isotope sensitive analytical techniques were used to analyze the solution and altered glass samples, helping to understand the driving forces and rate limiting processes controlling long-term glass alteration. At pH 9, the corrosion rate continuously drops and the glass slowly transforms into a uniform, homogeneous and isovolumic amorphous alteration layer. The mechanisms responsible for this transformation are water diffusion through the growing alteration layer and ion exchange. We demonstrate that this amorphous alteration layer is not a precipitate resulting from the hydrolysis of the silicate network; it inherits from the glass structure from which the most weakly bonded cations (Na, Ca and B) have been released. At pH 11.5, the alteration process is very different: the high solubility of glass network formers (Si, Al, Zr) triggers the rapid and complete dissolution of the glass (dissolution becomes congruent) and precipitation of amorphous and crystalline phases. Unlike at pH 9 where glass corrosion rate decreased by 3 orders of magnitude likely due to transport-limiting phenomenon within the amorphous alteration layer, the rate at pH 11.5 is maintained at a value close to the forward rate due to both the hydrolysis of the silicate network and the precipitation of CSH and zeolites. This study provides key information for a unified model for glass dissolution.

  2. 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

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

    OpenAIRE

    Thomas Mennecart; Hamad ul Hassan; Alper Güner; Noomane Ben Khalifa; Mohamad Hosseini

    2016-01-01

    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, t...

  4. Recycle Glass in Foam Glass Production

    OpenAIRE

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

    2014-01-01

    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. 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....

  6. Thermochemical study of rare earth and nitrogen incorporation in glasses

    Science.gov (United States)

    Zhang, Yahong

    Rare earth containing aluminosilicate, borosilicate, aluminate and nitrogen containing aluminosilicate glasses are technically important materials. They have extraordinary physical and chemical properties such as high glass transition temperature, very low electrical conductivity, and excellent chemical stability. These unique properties lead to applications as coatings on metals and ceramics, optical fibers, semiconductors, and nuclear waste containment materials. In addition, such systems contain the most widely used additives for sintering of Si3N4, SiAlON and SiC ceramics for high temperature applications. Thermodynamic properties and the relations among energetics, structure and bonding are essential to controlling processing parameters to synthesize, at lower cost, materials having better properties. Earlier investigations mainly pertained to specific physical properties of rare-earth doped oxide and oxynitride glasses. Work on the thermodynamic stability and materials compatibility has been very sparse. High temperature solution calorimetry in molten oxide solvents is a powerful tool for the thermodynamic study of refractory materials. With implementation and improvement, this technique has been applied to the first measurement of enthalpies of formation of RE-Si-Al-O glasses, REAlO3 glasses, RE-Si-Al-O-N glasses, and Si3N 4 and Ge3N4 with high pressure spinel structure. The first successful synthesis of REAlO3 glasses has been achieved by containerless melting. Their large enthalpies of crystallization confirm that they are reluctant glass formers. For glasses along the 2REAlO3 -3SiO2 join, the strongly negative heats of mixing support the absence of miscibility gaps except possibly at very high silica content. Energetic evidence has been presented for incipient phase-ordered regions in Gd- or Hf-containing sodium alumino-borosilicate glasses for plutonium immobilization. Linear relations between enthalpies of formation of RESiAlON glasses from elements and

  7. Glass packages in interim storage; Les verres dans les stockages

    Energy Technology Data Exchange (ETDEWEB)

    Jacquet-Francillon, N.

    1994-10-01

    This report summarize the current state of knowledge concerning the behavior of type C waste packages consisting of vitrified high-level solutions produced by reprocessing spent fuel. The composition and the physical and chemical properties of the feed solutions are reviewed, and the vitrification process is described. Sodium alumino-borosilicate glass compositions are generally employed - the glass used at la Hague for LWR fuel solutions, for example, contains 45 % SiO{sub 2}. The major physical, chemical, mechanical and thermal properties of the glass are reviewed. In order to allow their thermal power to diminish, the 3630 glass packages produced (as of January 1993) in the vitrification facilities at Marcoule and La Hague are placed in interim storage for several decades. The actual interim storage period has not been defined, as it is closely related to the concept and organization selected for the final destination of the packages: a geological repository. The glass behavior under irradiation is described. Considerable basic and applied research has been conducted to assess the aqueous leaching behavior of nuclear containment glass. The effects of various repository parameters (temperature, flow rate, nature of the environmental materials) have been investigated. The experimental findings have been used to specify a model describing the kinetics of aqueous corrosion of the glass. More generally all the ``source term`` models developed in France by the CEA or by ANDRA are summarized. (author). 152 refs., 33 figs.

  8. 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. PMID:27194443

  9. Iron phosphate glass for immobilization of 99Tc

    International Nuclear Information System (INIS)

    Highlights: •99Tc (surrogated by Re) was immobilized in an iron phosphate glass. •∼1.1 mass% Re was retained, possibly dissolved, in the iron phosphate glass. •The 7-day PCT normalized release of Re was −2 g/m2. •Re concentration in the glass rapidly decreased with increasing melting temperature and duration. -- Abstract: Technetium-99 (99Tc) can bring serious environmental threats because of its long half-life (τ1/2 = ∼2.1 × 105 years), high fission yield (∼6%), and high solubility and mobility in the ground water. The high volatility makes it difficult to immobilize 99Tc in continuous melters vitrifying 99Tc-containing nuclear wastes in borosilicate glasses. This work explores a possibility of incorporating a high concentration of 99Tc, surrogated by the non-radioactive Re, in an iron phosphate glass by melting mixtures of iron phosphate glass frits with 1.5–6 mass% KReO4 at ∼1000 °C. The retention of Re achieved was ∼1.1 mass%. The normalized Re release by the 7-day Product Consistency Test was −2 g/m2. Surprisingly, the Re escaped from the melt within a short time of heating, especially when the temperature was increased. Therefore, 99Tc volatilization would still be a challenging task for its immobilization in iron phosphate glasses

  10. 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}.

  11. Nuclear glass durability: new insight into alteration layer properties

    International Nuclear Information System (INIS)

    We have performed TEM, Raman microspectroscopy, and Nano-SIMS characterization of borosilicate glass samples altered for nearly 26 years at 90 degrees C in a confined granitic medium in order to better understand the rate-limiting mechanisms under conditions representative of a deep geological repository for vitrified radioactive waste. For the first time, we show a thick interphase that behaves like a diffusion barrier between the pristine glass and the other alteration products (porous gel and crystalline phases). Our findings indicate that the glass undergoes two distinct irreversible reactions: (i) hydration of the pristine glass controlled by water diffusion with a diffusion coefficient of 2 * 10-21 m2/s and (ii) transformation of the hydrated glass into a macroporous gel with major structural changes. Both materials are nonstoichiometric and metastable. A final reversible reaction leads to the formation of crystalline phases that consume elements forming the gel layer and the hydrated glass. All these reactions must be combined in a model to predict long-term rates of nuclear glass in natural environments. (authors)

  12. 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.......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....

  13. 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.

  14. Effect of Kovar alloy oxidized in simulated N2/H2O atmosphere on its sealing with glass

    Institute of Scientific and Technical Information of China (English)

    Dawei Luo; Wenbo Leng; Zhuoshen Shen

    2008-01-01

    The effect of Kovar alloy oxidized in simulated field atmosphere on its sealing with glass was studied in this article. After Kovar plates and pins were preoxidized in N2 with 0℃, 10℃ and 20℃ dew points at 1000℃ for different times, Fe3O4 and Fe2O3 existed in the oxidation products on Kovar surface, and the quantity of Fe2O3 increased with increasing dew point and oxidation time.Then they were sealed with borosilicate glass insulator at 1030℃ for 20 min. The results indicated that the type and quantity of oxidation products would directly influence the quality of glass-to-metal seals. With the increase of oxidation products, gas bubbles in the glass insulator were more serious, the climbing height of glass along the pins was higher, and corrosion of Kovar pins caused from the molten glass was transformed from uniform to the localized.

  15. R7T7-type HLW glass alteration under irradiation. Study of the residual alteration rate regime

    International Nuclear Information System (INIS)

    In France, fission products and minor actinides remaining after reprocessing of spent nuclear fuel are confined in a borosilicate glass matrix, named R7T7, for disposal in a geological repository. However, in these conditions, after several thousand years, water could arrive in contact with glass and be radio-lysed. In this work, we investigated the irradiation influence and especially the influence of the energy deposition on the residual glass alteration rate regime in pure water. Two types of leaching tests have been carried out. The first were performed on radioactive glass and the second on a SON68 glass (nonradioactive surrogate of R7T7 glass) under external irradiation γ. (author)

  16. 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....

  17. Spin glasses

    CERN Document Server

    Bovier, Anton

    2007-01-01

    Spin glass theory is going through a stunning period of progress while finding exciting new applications in areas beyond theoretical physics, in particular in combinatorics and computer science. This collection of state-of-the-art review papers written by leading experts in the field covers the topic from a wide variety of angles. The topics covered are mean field spin glasses, including a pedagogical account of Talagrand's proof of the Parisi solution, short range spin glasses, emphasizing the open problem of the relevance of the mean-field theory for lattice models, and the dynamics of spin glasses, in particular the problem of ageing in mean field models. The book will serve as a concise introduction to the state of the art of spin glass theory, usefull to both graduate students and young researchers, as well as to anyone curious to know what is going on in this exciting area of mathematical physics.

  18. 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.

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

    International Nuclear Information System (INIS)

    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.

  20. 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.

  1. Molecular tailoring of solid surfaces

    CERN Document Server

    Evenson, S A

    1997-01-01

    The overall performance of a material can be dramatically improved by tailoring its surface at the molecular level. The aim of this project was to develop a universal technique for attaching dendrimers (well-defined, nanoscale, functional polymers) and Jeffamines (high molecular weight polymer chains) to the surface of any shaped solid substrate. This desire for controlled functionalization is ultimately driven by the need to improve material compatibility in various biomedical applications. Atomic force microscopy (AFM) was used initially to study the packing and structure of Langmuir-Blodgett films on surfaces, and subsequently resulted in the first visualization of individual, spherically shaped, nanoscopic polyamidoamine dendrimers. The next goal was to develop a methodology for attaching such macromolecules to inert surfaces. Thin copolymer films were deposited onto solid substrates to produce materials with a fixed concentration of surface anhydride groups. Vapor-phase functionalization reactions were t...

  2. Chemical states of molybdenum in radioactive waste glass

    International Nuclear Information System (INIS)

    In order to confirm an expectation that the chemical state of molybdenum in glass reflects the phase separation tendency of the yellow solid from the melt of borosilicate glass, simulated waste glasses were prepared, and ESCA analysis was performed using a commercially available electron spectrometer (PHI550 E) with an excitation source consisting of Mg Kα-ray. The effects of the concentration of Mo and FE2O3 and the melting atmosphere (oxidizing or reducing) in which the samples were prepared on the chemical state of Mo and the solubility of MoO3 were examined. From the observation of Mo spectra, it was shown that Mo in waste glass had several valencies, e.g., Mo(3), Mo(4), Mo(5) and Mo(6), while Mo in the yellow solid separated from the melts exhibited hexa-valent state, the peak intensity of higher valencies increased relatively with the increase of MoO3 concentration, but the chemical state of Mo did not change remarkably around the solubility limit of MoO3, the melting atmosphere influenced on the Mo state in the waste glass, the peak intensity of Mo(6) increased relatively with the increasing Fe2O3 concentration, and Mo in devitrified glass exhibited hexa-valent state. (Yoshitake, I.)

  3. Rare earth impact on glass structure and alteration kinetics

    International Nuclear Information System (INIS)

    This work is related to the question of the geological deep repository of high-level waste glass. These wastes include fission products and minor actinides, elements which can be simulated by rare earths. As new glass compositions could enable increased rare earth concentrations, it is crucial to know and understand rare earth impact on glass structure on the one hand, and on glass alteration kinetics or their incorporation into an altered layer. This work studied simplified borosilicate glasses in order to limit synergetic effects between rare earths and other elements. Various complementary techniques were used to characterize pristine and altered glasses (solid-high resolution NMR, Raman spectroscopy, fluorescence, SIMS, SAXS). Firstly, the structural role of a rare earth is discussed and is compared to a calcium cation. The local environment of rare earths is also probed. Secondly, rare earth (nature and concentration) impact on several alteration regimes was studied (initial rate, rate drop). Then, after alteration, rare earth elements being retained within the altered layer, the structural impact of rare earth elements (and their local environment) in this alteration layer was also investigated. (author)

  4. 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. PMID:10126157

  5. 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.

  6. 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.

  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. Recent developments in glasses for fiber and fusion lasers

    International Nuclear Information System (INIS)

    The optical properties of rare earth ions and their variations with composition were investigated in a wide range of simple and complex oxide and fluoride glasses. In addition, site to site variations in spectroscopic properties which affect the laser gain profile and extraction efficiency were investigated using a combination of optical spectroscopy, x-ray absorption fine structure (EXAFS), and computer simulations of glass structure. Results of these studies, ability to tailor optical properties by changing glass composition, and the applications of glass for fiber and inertial confinement fusion lasers are discussed

  9. 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 ...

  10. Development and adoption of low sodium glass frit for vitrification of high level radioactive liquid waste at Tarapur

    International Nuclear Information System (INIS)

    High level Liquid Waste (HLW) is generated during the reprocessing of spent nuclear fuel which is used to recover uranium and plutonium. More than 99% of the fission product activity generated during the burning of nuclear fuel in the reactor is present in HLW. For the efficient management of HLW by vitrification, sodium borosilicate glass has been adopted worldwide. Sodium oxide acts as modifier in glass matrix and variation in its concentration may vary the properties of the glass and hence the melter parameters. The HLW presently used for vitrification has higher concentration of sodium. As the composition of the base glass is fixed the concentration of Na in the HLW is one of the limiting factors for the waste loading for the vitrification process. Present article gives a brief account of the formulation of a base glass frit with lower sodium content and the feedback after implementing in the vitrification plant. (author)

  11. Fabrication and characterization of MCC [Materials Characterization Center] approved testing material---ATM-2, ATM-3, and ATM-4 glasses

    International Nuclear Information System (INIS)

    Materials Characterization Center glasses ATM-2, ATM-3, and ATM-4 are designed to simulate high-level waste glasses that are likely to result from the reprocessing of commercial nuclear reactor fuels. The three Approved Testing Materials (ATMs) are borosilicate glasses based upon the MCC-76-68 glass composition. One radioisotope was added to form each ATM. The radioisotopes added to form ATM-2, ATM-3, and ATM-4 were 241Am, 237Np, and 239Pu, respectively. Each of the ATM lots was produced in a nominal lot size of 450 g from feed stock melted in a nitrogen-atmosphere glove box at 1200/degree/C in a platinum crucible. Each ATM was then cast into bars. Analyzed compositions of these glasses are listed. The nonradioactive elements were analyzed by inductively coupled argon plasma atomic emission spectroscopy (ICP), and the radioisotope analyses were done by alpha energy analysis. Results are discussed. 7 refs., 3 figs., 5 tabs

  12. The preparation of uranium-doped glass reference materials for environmental measurements

    Science.gov (United States)

    Raptis, K.; Ingelbrecht, C.; Wellum, R.; Alonso, A.; De Bolle, W.; Perrin, R.

    2002-03-01

    Seven different uranium glass powders containing 5 mass% uranium with 235U abundances from natural to highly enriched have been prepared for the IRMM support programme to the International Atomic Energy Agency (IAEA) and for the IRMM external NUSIMEP quality control programme (Nuclear Signatures Interlaboratory Measurement Evaluation Programme). The particles will be primarily used, blended with (inactive) matrix glass powder in various ratios to simulate environmental samples containing "hot" particles in order to assess the performance of various separation and measurement techniques. High-purity borosilicate glass was prepared by blending of powders, melting and grinding by ball milling and jet milling to a powder of about 12 μm. A quantity of this glass was then blended with U 3O 8, melted and milled to powder. Laser diffraction measurements were made to ensure that the particle size distribution of the uranium glass matched that of the matrix glass in order to ensure homogeneous blending. The final yield was 30-40 g of each uranium glass and 1 kg of matrix glass. The glasses have been certified as reference materials for isotope abundances of uranium.

  13. 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%)

  14. 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.

  15. Effect of glass composition on waste form durability: A critical review

    Energy Technology Data Exchange (ETDEWEB)

    Ellison, A.J.G.; Mazer, J.J.; Ebert, W.L. [Argonne National Lab., IL (United States). Chemical Technology Div.

    1994-11-01

    This report reviews literature concerning the relationship between the composition and durability of silicate glasses, particularly glasses proposed for immobilization of radioactive waste. Standard procedures used to perform durability tests are reviewed. It is shown that tests in which a low-surface area sample is brought into contact with a very large volume of solution provide the most accurate measure of the intrinsic durability of a glass composition, whereas high-surface area/low-solution volume tests are a better measure of the response of a glass to changes in solution chemistry induced by a buildup of glass corrosion products. The structural chemistry of silicate and borosilicate glasses is reviewed to identify those components with the strongest cation-anion bonds. A number of examples are discussed in which two or more cations engage in mutual bonding interactions that result in minima or maxima in the rheologic and thermodynamic properties of the glasses at or near particular optimal compositions. It is shown that in simple glass-forming systems such interactions generally enhance the durability of glasses. Moreover, it is shown that experimental results obtained for simple systems can be used to account for durability rankings of much more complex waste glass compositions. Models that purport to predict the rate of corrosion of glasses in short-term durability tests are evaluated using a database of short-term durability test results for a large set of glass compositions. The predictions of these models correlate with the measured durabilities of the glasses when considered in large groupings, but no model evaluated in this review provides accurate estimates of durability for individual glass compositions. Use of these models in long-term durability models is discussed. 230 refs.

  16. Effect of glass composition on waste form durability: A critical review

    International Nuclear Information System (INIS)

    This report reviews literature concerning the relationship between the composition and durability of silicate glasses, particularly glasses proposed for immobilization of radioactive waste. Standard procedures used to perform durability tests are reviewed. It is shown that tests in which a low-surface area sample is brought into contact with a very large volume of solution provide the most accurate measure of the intrinsic durability of a glass composition, whereas high-surface area/low-solution volume tests are a better measure of the response of a glass to changes in solution chemistry induced by a buildup of glass corrosion products. The structural chemistry of silicate and borosilicate glasses is reviewed to identify those components with the strongest cation-anion bonds. A number of examples are discussed in which two or more cations engage in mutual bonding interactions that result in minima or maxima in the rheologic and thermodynamic properties of the glasses at or near particular optimal compositions. It is shown that in simple glass-forming systems such interactions generally enhance the durability of glasses. Moreover, it is shown that experimental results obtained for simple systems can be used to account for durability rankings of much more complex waste glass compositions. Models that purport to predict the rate of corrosion of glasses in short-term durability tests are evaluated using a database of short-term durability test results for a large set of glass compositions. The predictions of these models correlate with the measured durabilities of the glasses when considered in large groupings, but no model evaluated in this review provides accurate estimates of durability for individual glass compositions. Use of these models in long-term durability models is discussed. 230 refs

  17. 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.

  18. 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.

  19. Aeroelastic Tailoring via Tow Steered Composites

    Science.gov (United States)

    Stanford, Bret K.; Jutte, Christine V.

    2014-01-01

    The use of tow steered composites, where fibers follow prescribed curvilinear paths within a laminate, can improve upon existing capabilities related to aeroelastic tailoring of wing structures, though this tailoring method has received relatively little attention in the literature. This paper demonstrates the technique for both a simple cantilevered plate in low-speed flow, as well as the wing box of a full-scale high aspect ratio transport configuration. Static aeroelastic stresses and dynamic flutter boundaries are obtained for both cases. The impact of various tailoring choices upon the aeroelastic performance is quantified: curvilinear fiber steering versus straight fiber steering, certifiable versus noncertifiable stacking sequences, a single uniform laminate per wing skin versus multiple laminates, and identical upper and lower wing skins structures versus individual tailoring.

  20. 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.

  1. 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

  2. Welding of tailored blanks of different materials

    OpenAIRE

    Suban, Marjan; Tušek, Janez; Kampuš, Zlatko

    2015-01-01

    This paper treats welding of tailored blanks made of different materials. In general, fusion welding and welding with pressure, practically without fusion, are described. Fusion welding may be carried out with or without the addition of filler material. In Section 3, general characteristics of tailored blanks are described. In Section 4, MIG welding and laser welding of austenitic stainless steel with ferrite non-stainless steel are described. After welding, hardness of the welded joints was ...

  3. Transmission electron microscopy of simulated DWPF high level nuclear waste glasses following gamma irradiation

    International Nuclear Information System (INIS)

    In the near future the Defense Waste Processing Facility (DWPF) at the Savannah River Site (SRS) will begin stabilizing high-level radioactive waste using borosilicate glass. The molten waste glass will be poured into stainless steel canisters which, after cooling, will be sealed shut to produce the canistered waste forms. Following interim storage at SRS, the glass-filled canisters will be shipped to an appropriate geologic repository for final disposal. As a result of radioactive decay in the waste, the glasses will absorb large doses of alpha, beta, gamma, neutron, and alpha recoil radiation which raises issues regarding the stability of the canistered waste forms. Thermal analysis testing revealed slight weight changes, which were a function of gamma irradiation, in a highly reduced DWPF simulated waste glass. Transmission electron microscopy (TEM) was performed on these glasses to see if the weight change corresponded to microstructural variations. TEM analyses showed that no microstructural changes were attributable to gamma irradiation. Exposure of the samples to the electron beam in the TEM did result in some changes in the glass microstructures in some cases. These changes were likely due to localized heating of the glass due to interactions with the transmitted electrons

  4. Tailored ceramic consolidation forms for ICPP waste compositions

    International Nuclear Information System (INIS)

    This paper reports a polyphase tailored ceramic developed for the consolidation of simulated ICPP (Idaho Chemical Processing Plant)-type high Zr content high-level waste (HLW) calcines. The ceramic is specifically designed to provide chemically stable host phases for each species present in the HLW and to maximize waste volume reduction through high loadings and form density. The ceramic is designed for a 73 wt% waste loading with a density of 3.35 ± 0.05 (g/cm3). The major phase in the ceramic is a high-silica glass, which contains the neutron poison boron as well as the majority of the nonrefractory species in the waste. The primary crystalline phases are calcium fluoride, calcium-yttrium stabilized cubic zirconia, a hexagonal apatite type silicate containing the plutonium simulant Ce, and a Cd metal phase. Minor phases include zircon, zirconolite, and a sphene-type. Leaching testing and microscopic analysis shows the ceramic form to be chemically durable, with only the glass phase showing any detectable dissolution in deionized water at 90 degrees C

  5. High rate operation of micro-strip gas chambers on diamond-coated glass

    CERN Document Server

    Bouclier, Roger; Million, Gilbert; Ropelewski, Leszek; Sauli, Fabio; Temmel, T; Cooke, R A; Donnel, S; Sastri, S A; Sonderer, N

    1996-01-01

    Very high rate operation of micro­strip gas chambers can be achieved using slightly conducting substrates. We describe preliminary measurements realized with detectors manufactured on boro-silicate glass coated, before the photo-lithographic processing, with a diamond layer having a surface resistivity of around 1014 ‡/o. Stable medium-term operation, and a rate capability largely exceeding the one obtained with identical plates manufactured on uncoated glass are demonstrated. If these results are confirmed by long-term measurements the diamond coating technology appears very attractive since it allows, with a moderate cost overhead, to use thin, commercially available glass with the required surface quality for the large-scale production of gas micro-strip detectors.

  6. 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.

  7. 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.

  8. Immobilization of Pu-containing wastes into glass and ceramics: Results of US-Russia collaboration

    Science.gov (United States)

    Anderson, E. B.; Aloy, A. S.; Burakov, B. E.; Jardine, L. J.

    2000-07-01

    This continuing collaboration between the V.G. Khlopin Radium Institute (KRI) in St. Petersberg, Russia, and Lawrence Livermore National Laboratory (LLNL) in the United States was initiated in 1997. The collaboration is focused on plutonium immobilization to support the disposition of excess weapons plutonium in the US and Russia. Our work consists primarily of laboratory-scale experiments and studies of borosilicate and phosphate Pu-doped glasses and zircon/zirconia, mono-zirconia, and pyrochlore ceramics. The results were used to compare and evaluate the use of these various materials in Pu immobilization.

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

    International Nuclear Information System (INIS)

    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

  10. Optical and structural properties of ZnO-PbO-B2O3 and ZnO-PbO-B2O3-SiO2 glasses

    International Nuclear Information System (INIS)

    Borate and borosilicate glasses with compositions of xZnO-2xPbO-(1-3x)B2O3 and xZnO-2xPbO-1/2(1-3x)B2O3-1/2(1-3x)SiO2 with x varying from 0.1 to 0.26 mole fraction were prepared by the conventional melt quench technique. Optical and structural properties have been determined by using ultraviolet-visible (UV/vis) and Fourier transform infrared (FTIR) spectroscopic techniques. Decreases in the band gap from 3.57 to 2.62 eV for borate glasses and from 3.00 to 2.35 eV for borosilicate glasses with an increase in the metal oxide content is observed. The density and molar volume has also been measured. Increases in density from 3.994 to 6.339 g cm-3 for borate and from 4.221 to 6.548 g cm-3 for borosilicate glasses are observed with an increase in metal oxide (PbO, ZnO or PbO+ZnO) content. Changes in the atomic structure with composition are observed due to the formation of BO4- units

  11. Long-term performance assessment of nuclear waste and natural glasses in the geological repository: a geochemical modelling

    International Nuclear Information System (INIS)

    Nuclear waste loaded and natural (analogue) glasses were studied to understand neo-formed mineral species, formed in equilibrium with the physico-chemical conditions existing in the geological repository. To predict alteration-phases, dissolution equations for average vitrification system (AVS), barium borosilicate (BBS) and obsidian glasses were calculated, considering glass composition, pressure, temperature and pH conditions. Progress of reaction plotted against saturation index indicates saturation with solid phases - chamosite, chalcedony and Ca-beidellite in obsidian; greenalite and fayalite in AVS; and coffinite in BBS glass. Activities and molalities of aqueous species together with the number of moles of each mineral species produced and degenerated during the progress of the reaction (as a function of time) are discussed here. (author)

  12. 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.

  13. 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.

  14. 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

  15. Small-scale, joule-heated melting of Savannah River Plant waste glass. I. Factors affecting large-scale vitrification tests

    International Nuclear Information System (INIS)

    A promising method of immobilizing SRP radioactive waste solids is incorporation in borosilicate glass. In the reference vitrification process, called joule-heated melting, a mixture of glass frit and calcined waste is heated by passage of an electric current. Two problems observed in large-scale tests are foaming and formation of an insoluble slag. A small joule-heated melter was designed and built to study problems such as these. This report describes the melter, identifies factors involved in foaming and slag formation, and proposes ways to overcome these problems

  16. 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.

  17. 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.

  18. 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)

  19. 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.

  20. 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.

  1. Light management in flexible glass by wood cellulose coating.

    Science.gov (United States)

    Fang, Zhi-Qiang; Zhu, Hong-Li; Li, Yuan-Yuan; Liu, Zhen; Dai, Jia-Qi; Preston, Colin; Garner, Sean; Cimo, Pat; Chai, Xin-Sheng; Chen, Gang; Hu, Liang-Bing

    2014-01-01

    Ultra-thin flexible glass with high transparency is attractive for a broad range of display applications; however, substrates with low optical haze are not ideal for thin film solar cells, since most of the light will go through the semiconductor layer without scattering, and the length of light travelling path in the active layer is small. By simply depositing a layer of TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical)-oxidized wood fibers (TOWFs), we are able to tailor the optical properties of flexible glass dramatically from exhibiting low haze (glass is investigated. As the average fiber length decreases, the transmission haze of TOWF-coated flexible glass illustrates a decreasing trend. Earth-abundant natural materials for transparent, hazy, and flexible glass have tremendous applicability in the fabrication of flexible optoelectronics with tunable light scattering effects by enabling inexpensive and large-scale processes. PMID:25068486

  2. Tailoring group velocity by topology optimization

    DEFF Research Database (Denmark)

    Stainko, Roman; Sigmund, Ole

    2007-01-01

    up with slow light, zero group velocity dispersion photonic waveguides or photonic waveguides with tailored dispersion properties for dispersion compensation purposes. An example concerning the design of a wide bandwidth, constant low group velocity waveguide demonstrate the e±ciency of the method....

  3. Dispersion-tailored active-fiber solitons

    Science.gov (United States)

    van Tartwijk, Guido H. M.; Essiambre, René-Jean; Agrawal, Govind P.

    1996-12-01

    We show analytically that tailoring the fiber dispersion appropriately can cause optical solitons to propagate unperturbed, without emission of dispersive waves, in a distributed-gain fiber amplifier with a nonuniform gain profile. We apply our scheme to a bidirectionally pumped fiber amplifier and discuss the importance of higher-order nonlinear and dispersive effects for short solitons.

  4. Recycling of Glass

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Damgaard, Anders

    2011-01-01

    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....

  5. DEVELOPMENT OF GLASS AND CRYSTALLINE CERAMIC FORMS FOR DISPOSITION OF EXCESS PLUTONIUM

    Energy Technology Data Exchange (ETDEWEB)

    Marra, James; Cozzi, A; Crawford, C.; Herman, C.; Marra, John; Peeler, D.

    2009-09-10

    In the aftermath of the Cold War, the United States Department of Energy (DOE) has identified up to 50 metric tons of excess plutonium that needs to be dispositioned. The bulk of the material is slated to be blended with uranium and fabricated into a Mixed Oxide (MOX) fuel for subsequent burning in commercial nuclear reactors. Excess plutonium-containing impurity materials making it unsuitable for fabrication into MOX fuel will need to be dispositioned via other means. Glass and crystalline ceramics have been developed and studied as candidate forms to immobilize these impure plutonium feeds. A titanate-based ceramic was identified as an excellent actinide material host. This composition was based on Synroc compositions previously developed for nuclear waste immobilization. These titanate ceramics were found to be able to accommodate extremely high quantities of fissile material and exhibit excellent aqueous durability. A lanthanide borosilicate (LaBS) glass was developed to accommodate high concentrations of plutonium and to be very tolerant of impurities yet still maintain good aqueous durability. Recent testing of alkali borosilicate compositions showed promise of using these compositions to disposition lower concentrations of plutonium using existing high level waste vitrification processes. The developed waste forms all appear to be suitable for Pu disposition. Depending on the actual types and concentrations of the Pu residue streams slated for disposition, each waste form offers unique advantages.

  6. 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.)

  7. Fracture strength of glass chips for high-pressure microfluidics

    Science.gov (United States)

    Andersson, Martin; Hjort, Klas; Klintberg, Lena

    2016-09-01

    High-pressure microfluidics exposes new areas in chemistry. In this paper, the reliability of transparent borosilicate glass chips is investigated. Two designs of circular cavities are used for fracture strength tests, either 1.6 mm wide with rounded corners to the fluid inlets, or 2.0 mm wide with sharp inlet corners. Two kinds of tests are done, either short-term, e.g. pressurization to fracture at room temperature, or long-term, with fracture at constant pressurization for up to one week, in the temperature region 11–125 °C. The speed of crack fronts is measured using a high-speed camera. Results show fracture stresses in the range of 129 and 254 MPa for short-term measurements. Long-term measurements conclude the presences of a temperature and stress dependent delayed fracture. For a reliability of one week at 11–38 °C, a pressure limit is found at the lower end of the short-term measurements, or 15% lower than the average. At 80 °C, this pressure limit is 45% lower. Crack speeds are measured to be 10‑5 m s‑1 during short-term fracture. These measurements are comparable with estimations based on slow crack growth and show that the growth affects the reliability of glass chips. This effect is strongly affected by high temperatures, thus lowers the operating window of high-pressure glass microfluidic devices.

  8. 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.

  9. Process control and glass product quality assessment applied in the VEK plant

    International Nuclear Information System (INIS)

    Vitrification of about 60 m3 of high-level liquid waste (HLLW) with a total activity of 7.7E17 Bq has been a major step within the decommissioning program of the former WAK pilot reprocessing plant. The immobilization in borosilicate glass was carried out in a new vitrification plant designated VEK using a liquid-fed ceramic-lined melter as melting technique. Approval of the waste glass canisters produced by VEK required the accordance with a set of 16 specified final disposal-relevant parameters/properties. To meet these specified parameters, an appropriate process and product control strategy has been used. Main focus has been laid on control of the melter feed streams (HLLW, glass frit) as they are decisive for the glass composition and, therefore, for a major part of the mentioned properties. As a result of these control steps all 140 glass canisters produced by VEK have passed the check and have been released for final disposal. The examination of the respective canister specification was performed by experts on behalf of the German federal government. The paper describes the method of process and product control of VEK and depicts the compliance of the generated waste glass properties with the required specification. (author)

  10. Analysis of one year in-situ burial of nuclear waste glasses in Stripa

    International Nuclear Information System (INIS)

    Alkali borosilicate (ABS) glasses have been under development for many years for use in the solidification of high-level radioactive wastes. Many laboratory studies of the leach behavior of ABS glasses have been conducted, and the results show excellent resistance of the latest generation of ABS nuclear waste glasses to attack by water at temperatures up to 900C. However, international plans for geologic storage of nuclear waste glasses invariably involve use of a multibarrier storage system in order to further minimize risks within the first few hundred years, or thermal period, of storage. Very few data are available regarding the behavior of ABS nuclear waste glasses in the presence of a variety of storage system components. It is also generally recognized that laboratory tests at best only approximate the actual chemical and oxidation characteristics of a geologic repository site. Consequently, in order to test possible synergistic interactions of the materials in a nuclear waste storage system under real repository conditions, an in situ burial experiment in the Stripa mine in Sweden was initiated several years ago. Two nuclear waste glasses containing 9% simulated waste, ABS 39 and ABS 41, were selected for the burial experiment because their compositions were close to that to be used for commercial solidification operations in France

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

    Directory of Open Access Journals (Sweden)

    Faidra Oikonomopoulou

    2015-06-01

    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.  

  12. 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.

  13. Why do certain glasses with a high dissolution rate undergo a low degree of corrosion?

    International Nuclear Information System (INIS)

    Two series of borosilicate glasses were prepared for studying the influence of the substitution of (i) CaO for Na2O and (ii) ZrO2 for SiO2 on glass durability. They were corroded in buffered aqueous solution at pH 6.9 and pH 8.0. An inverse correlation was found between the initial dissolution rate and the final degree of corrosion in the saturation regime. It was observed as a function of pH for a given glass as well as a function of glass composition at a fixed pH. A ToF-SIMS study of the permeation of foreign ions in the corrosion layer, SAXS characterization of the layer reorganization, and Monte Carlo simulations of the corrosion provide the key to this paradoxical behavior: glasses with a fast dissolution rate undergo a fast restructuring of the corroded layer into a passivating film, which rapidly stops corrosion by porosity closure; on the contrary, the slow restructuring of glasses with a slow dissolution rate leads to a higher degree of corrosion. (authors)

  14. Encapsulation of TRISO particle fuel in durable soda-lime-silicate glasses

    International Nuclear Information System (INIS)

    Tri-Structural Isotropic (TRISO) coated particle-fuel is a key component in designs for future high temperature nuclear reactors. This study investigated the suitability of three soda lime silicate glass compositions, for the encapsulation of simulant TRISO particle fuel. A cold press and sinter (CPS) methodology was employed to produce TRISO particle–glass composites. Composites produced were determined to have an aqueous durability, fracture toughness and Vickers’ hardness comparable to glasses currently employed for the disposal of high level nuclear wastes. Sintering at 700 °C for 30 min was found to remove all interconnected porosity from the composite bodies and oxidation of the outer pyrolytic carbon layer during sintering was prevented by processing under a 5% H2/N2 atmosphere. However, the outer pyrolytic carbon layer was not effectively wetted by the encapsulating glass matrix. The aqueous durability of the TRISO particle–glass composites was investigated using PCT and MCC-1 tests combined with geochemical modelling. It was found that durability was dependent on silicate and calcium solution saturation. This study provides significant advancements in the preparation of TRISO particle encapsulant waste forms. The potential for the use of non-borosilicate sintered glass composites for TRISO particle encapsulation has been confirmed, although further refinements are required

  15. Fabrication and characterization of MCC approved testing material - ATM-8 glass

    Energy Technology Data Exchange (ETDEWEB)

    Wald, J.W.

    1985-10-01

    The Materials Characterization Center (MCC) Approved Testing Material ATM-8 is a borosilicate glass that incorporates elements typical of high-level waste (HLW) resulting from the reprocessing of commercial nuclear reactor fuel. Its composition is based upon the simulated HLW glass type 76-68 (Mendel, J.E. et al., 1977, Annual Report of the Characteristics of High-Level Waste Glasses, BNWL-2252, Pacific Northwest Laboratory, Richland, Washington), to which depleted uranium, technetium-99, neptunium-237 and plutonium-239 have been added at moderate to low levels. The glass was requested by the Nevada Nuclear Waste Storage Investigations (NNWSI) Project. It was produced by the MCC at the Pacific Northwest Laboratory (PNL) operated for the Department of Energy (DOE) by Battelle Memorial Institute. ATM-8 glass was produced in April of 1984, and is the second in a series of testing materials for NNWSI. This report discusses its fabrication (starting materials, batch and glass preparation, measurement and testing equipment, other equipment, procedures, identification system and materials availability and storage, and characterization (bulk density) measurements, chemical analysis, microscopic examination, and x-ray diffraction analysis. 4 refs., 2 figs., 10 tabs.

  16. Doping influence by some transition elements on the irradiation effects in nuclear waste glasses

    International Nuclear Information System (INIS)

    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 β irradiated at different doses up to 109 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 Fe3+ 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 Fe3+ amount to a 25 % lower level during irradiation. Stopping irradiation causes a lower decrease of 65 %, suggesting a dynamic (h0/e-) consuming equilibrium. He+ and Kr3+ ions and γ irradiated glasses tend to confirm these phenomena for all kind of irradiation with electronic excitations. (author)

  17. Band gap and FTIR studies for copper-zinc sol-gel glasses

    Science.gov (United States)

    Kaur, G.; Kaur, Navneet; Rawat, Mohit; Singh, K.; Kumar, Vishal

    2016-05-01

    Sol-gel technique was used for synthesis of Calcium phosphorous Borosilicate (CaO-SiO2-B2O3-P2O5-CuO-ZnO) glasses by varying composition of Copper oxide and Zinc oxide. Sol-gel route uses organic precursors which provide better homogeneity and uniform particle size compared to melt quenched glass. Four different glass stoichiometries were characterised using UV-visible spectroscopy and Fourier transforms infra-red spectroscopy (FTIR). Infra-red spectrum of transmittance of powdered glass samples is obtained by FTIR which measure the transmittance of wavelength in them and it also determines the presence of different functional group. Band gap has been obtained using UV-visible spectroscopy for all the glasses so as to study the effect of increasing ZnO content in glass composition. The change in band gap with ZnO content is indication of the change in number of non-bridging oxygen's (NBO).

  18. Intrinsic single- and multiple-pulse laser-induced damage in silicate glasses in the femtosecond-to-nanosecond region

    International Nuclear Information System (INIS)

    We show that the threshold power density of the intrinsic laser-induced damage in borosilicate glass at ∼1 μm wavelength does not depend on pulse duration from 2x10-13 to 3x10-8 s and has the same value for both single- and multiple-pulse exposure of the sample. This indicates that the mechanism of the intrinsic damage in glasses involves a collective response of a certain volume in the dielectric as a whole, such as 'dielectric-metal' phase transition, rather than a process of individual generation and accumulation of electrons, such as multiphoton, tunneling, or avalanche. Also, we demonstrate that under femtosecond exposure the threshold of the plasma formation in transparent glasses is considerably higher than the threshold of the residual change of medium parameters

  19. Observation of Supercontinuum Generation and Darkening Effect in Bro-Silicate Glass under 800 nm Femtosecond Irradiations

    Science.gov (United States)

    Abdolahpour, D.; Jamshidi-Ghaleh, K.

    2007-04-01

    In this paper, we report the experimental observations of supercontinuum generation and darkening effect in bro-silicate glasses under 200 femtosecond pulses at wavelength of 800 nm. The spectrum of supercontinuum emission from the sample is recorded in the UV wavelength range. The length of filamentation or white light and darkening are investigated at different incident laser pulse energies. The begging position of the generated white light and darkening moves inside glass bulk with decreasing of incident pulse energy. The pulse energy threshold for supercontinuum generation and the laser-induced darkening in this material has been measured. By controlling of the laser-induced darkening in borosilicate glasses prepares a promising technique for designing optical devices.

  20. 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.

  1. Fabrication and characterization of MCC approved testing material - ATM-12 glass

    Energy Technology Data Exchange (ETDEWEB)

    Wald, J.W.

    1985-10-01

    The Materials Characterization Center (MCC) Approved Testing Material ATM-12 is a borosilicate glass that incorporates elements typical of high-level waste (HLW) resulting from the reprocessing of commercial nuclear reactor fuels. The composition has been adjusted to match that predicted for HLW type 76-68 glass at an age of 300 y. Radioactive constituents contained in this glass include depleted uranium, {sup 99}Tc, {sup 237}Np, {sup 239}Pu, and {sup 241}Am. The glass was produced by the MCC at the Pacific Northwest Laboratory (PNL). ATM-12 glass ws produced from July to November of 1984 at the request of the Nevada Nuclear Waste Site Investigations (NNWSI) Program and is the third in a series of glasses produced for NNWSI. Most of the glass produced was in the form of cast bars; special castings and crushed material were also produced. Three kilograms of ATM-12 glass were produced from a feedstock melted in a nitrogen-atmosphere glove box at 1150{sup 0}C in a platinum crucible, and formed into stress-annealed rectangular bars and the special casting shapes requested by NNWSI. Bars of ATM-12 were nominally 1.9 x 1.9 x 10 cm, with an average mass of 111 g each. Nineteen bars and 37 special castings were made. ATM-12 glass has been provided to the NNWSI Program, in the form of bars, crushed powder and special castings. As of August 1985 approximately 590 g of ATM-12 is available for distribution. Requests for materials or services related to this glass should be directed to the Materials Characterization Center Program Office, PNL.

  2. 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.

  3. Observation of the transition state for pressure-induced BO₃→ BO₄ conversion in glass.

    Science.gov (United States)

    Edwards, Trenton; Endo, Takatsugu; Walton, Jeffrey H; Sen, Sabyasachi

    2014-08-29

    A fundamental mechanistic understanding of the pressure- and/or temperature-induced facile transformation of the coordination environment of boron is important for changing the physical properties of glass. We have used in situ high-pressure (up to 2 gigapascals) boron-11 solid-state nuclear magnetic resonance spectroscopy in combination with ab initio calculations to investigate the nature of the transition state for the pressure-induced BO3→ BO4 conversion in a borosilicate glass at ambient temperature. The results indicate an anisotropic elastic deformation of the BO3 planar triangle, under isotropic stress, into a trigonal pyramid that likely serves as a precursor for the subsequent formation of a BO4 tetrahedron. PMID:25170146

  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. Cd And Se Atomic Environments During the Growth of CdSe Nanoparticles in Glass

    Energy Technology Data Exchange (ETDEWEB)

    Hayes, T.M.; Persans, P.D.; Filin, A.; Peng, C.; Huang, W.

    2006-10-27

    Thermal treatment of Cd and Se doped borosilicate glass yields CdSe nanoparticles that are interesting for applied and fundamental studies of quantum and size effects in semiconductors. Using x-ray absorption spectroscopy at both the Cd and Se K-edges, we have studied the local atomic structure for each of these reactants at several stages of particle growth. When the doped glass is quenched from 1050 C, the Cd neighbor is mostly oxygen and the Se neighbor is mostly Zn. With heat treatment at 600-750 C, the concentration of nearest neighbor Cd-Se bonds increases and becomes dominant while the optical spectrum evolves toward that of a composite containing CdSe.

  6. Spectroscopic investigations on Er3+/yb3+-doped oxyfluoride glass ceramicscontaining YOF nanocrystals

    Institute of Scientific and Technical Information of China (English)

    ZHENG Fei; XU Shiqing; ZHAO Shilong; DENG Degang; HUA Youjie; WANG Huanping

    2012-01-01

    Spectroscopic properties of Er3+/yb3+-doped transparent oxyfluoride borosilicate glass ceramics containing YOF nanocrystals were systematically investigated.X-ray diffraction (XRD) confirmed the formation of YOF nanocrystals in the glassy matrix.Based on the Judd-Ofelt theory,the intensity parameters Ω(i) (i=2,4,6),spontaneous emission probability,radiative lifetime,radiative quantum efficiency and the effective emission bandwidth were investigated.The upconversion luminescence intensity ofEr3+ ions in the glass ceramics increased significantly with the increasing crystallization temperature.The transition mechanisms of the green and red upeonversion luminescence were ascribed to a two-photon process,and the blue upconversion luminescence was a three-photon absorption process.

  7. 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.

  8. 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...

  9. Multiscale Surface-Attached Hydrogel Thin Films with Tailored Architecture.

    Science.gov (United States)

    Chollet, Benjamin; Li, Mengxing; Martwong, Ekkachai; Bresson, Bruno; Fretigny, Christian; Tabeling, Patrick; Tran, Yvette

    2016-05-11

    A facile route for the fabrication of surface-attached hydrogel thin films with well-controlled chemistry and tailored architecture on wide range of thickness from nanometers to micrometers is reported. The synthesis, which consists in cross-linking and grafting the preformed and ene-reactive polymer chains through thiol-ene click chemistry, has the main advantage of being well-controlled without the addition of initiators. As thiol-ene click reaction can be selectively activated by UV-irradiation (in addition to thermal heating), micropatterned hydrogel films are easily synthesized. The versatility of our approach is illustrated by the possibility to fabricate various chemical polymer networks, like stimuli-responsive hydrogels, on various solid substrates, such as silicon wafers, glass, and gold surfaces. Another attractive feature is the development of new complex hydrogel films with targeted architecture. The fabrication of various architectures for polymer films is demonstrated: multilayer hydrogel films in which single-networks are stacked one onto the other, interpenetrating networks films with mixture of two networks in the same layer, and nanocomposite hydrogel films where nanoparticles are stably trapped inside the mesh of the network. Thanks to its simplicity and its versatility this novel approach to surface-attached hydrogel films should have a strong impact in the area of polymer coatings. PMID:27008162

  10. Tailoring Patterns of Surface-Attached Multiresponsive Polymer Networks.

    Science.gov (United States)

    Chollet, Benjamin; D'Eramo, Loïc; Martwong, Ekkachai; Li, Mengxing; Macron, Jennifer; Mai, Thuy Quyen; Tabeling, Patrick; Tran, Yvette

    2016-09-21

    A new strategy for the fabrication of micropatterns of surface-attached hydrogels with well-controlled chemistry is reported. The "grafting onto" approach is preferred to the "grafting from" approach. It consists of cross-linking and grafting preformed and functionalized polymer chains through thiol-ene click chemistry. The advantage is a very good control without adding initiators. A powerful consequence of thiol-ene click reaction by UV irradiation is the facile fabrication of micropatterned hydrogel thin films by photolithography. It is achieved either with photomasks using common UV lamp or without photomasks by direct drawing due to laser technology. Our versatile approach allows the fabrication of various chemical polymer networks on various solid substrates. It is demonstrated here with silicon wafers, glass and gold surfaces as substrates, and two responsive hydrogels, poly(N-isopropylacrylamide) for its responsiveness to temperature and poly(acrylic acid) for its pH-sensitivity. We also demonstrate the fabrication of stable hydrogel multilayers (or stacked layers) in which each elementary layer height can widely range from a few nanometers to several micrometers, providing an additional degree of freedom to the internal architecture of hydrogel patterns. This facile route for the synthesis of micrometer-resolute hydrogel patterns with tailored architecture and multiresponsive properties should have a strong impact. PMID:27560306

  11. Dissolution of tailored ceramic nuclear waste forms

    International Nuclear Information System (INIS)

    Dissolution experiments on polyphase, high alumina tailored ceramic nuclear waste forms developed for the chemical immobilization of Savannah River Plant nuclear waste are described. Three forms of leach tests have been adopted; bulk samples conforming to the Materials Characterization Center Static Leach Test (MCC-1), a powdered sample leach test, and a leach test performed on transmission electron microscope thin foil samples. From analysis of these tests the crystalline phases that preferentially dissolve on leaching and the product phases formed are identified and related to the tailoring and processing schemes used in forming the ceramics. The thin foil sample leaching enables the role of intergranular amorphous phases as short-circuit leaching paths in polyphase ceramics to be investigated

  12. 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.

  13. Tailored Security and Safety for Pervasive Computing

    Science.gov (United States)

    Blass, Erik-Oliver; Zitterbart, Martina

    Pervasive computing makes high demands on security: devices are seriously resource-restricted, communication takes place spontaneously, and adversaries might control some of the devices. We claim that 1.) today’s research, studying traditional security properties for pervasive computing, leads to inefficient, expensive, and unnecessary strong and unwanted security solutions. Instead, security solutions tailored to the demands of a user, the scenario, or the expected adversary are more promising. 2.) Today’s research for security in pervasive computing makes naive, inefficient, and unrealistic assumptions regarding safety properties, in particular the quality of basic communication. Therefore, future security research has to consider safety characteristics and has to jointly investigate security and safety for efficient, tailored solutions.

  14. A Tailor Made Concrete Solution for Tunneling

    OpenAIRE

    Río, Olga; Arciniegas, Carlos

    2010-01-01

    Thc develoment of tailor made materials by using a performance based approach are attracting research interest in different construction areas due to the advantages of having solutions that should perform according to the specified needs. If focus is put on concrete and on the fitness of Its functional requirements. the rational procedure would be to state the required main structural, durability and executíon indicators (PI) and subindicators (PSI). i.e. mechanical strength al different age ...

  15. A Propulsion System Tailored to Cubesat Applications

    OpenAIRE

    Platt, Donald

    2007-01-01

    Cubesats and other nano- and pico-satellite platforms have traditionally not had the capability of on-board propulsion. A complete propulsion system tailored to cubesat and other nano-picosat applications is presented in this paper. This system has been demonstrated and is ready for use in cubesat missions. A diaphragm positive expulsion tank or integral structure/bladder tank has been developed for propellant storage and feed to the thrusters. Propellant systems available include hydrogen pe...

  16. Different approaches to tailoring chemical pulp fibres

    OpenAIRE

    El-Sharkawy, Khalil

    2008-01-01

    The objective of this thesis work was to examine different approaches to tailor chemical fibres of different raw materials. The focus in searching for new approaches was on pressure screen fractionation, selective treatment of each fraction, mechanical pre-treatment before refining, refiner loadability and its link to fibre properties and filling design, and on-line quality control of fibre properties. The evaluation is based on the impacts on fibre properties, filtration, refining and the re...

  17. Microstructural studies on some silicate and phosphate based glass-ceramics

    International Nuclear Information System (INIS)

    Recent developments have made it possible to make a new class of ceramic materials called glass-ceramics with tailored expansion coefficients and improved thermo-mechanical and corrosion resistance properties. Since these are formed by controlled crystallization in which crystallites are embedded in the glassy matrix, it is possible to make nano glass-ceramics having pronounced effect of particle size on various properties such as transparency, bioactivity, etc. In this talk, some of the recent results on micro-structural properties of a few glass-ceramic-to-metal sealants and bio-glass-ceramics are discussed

  18. Recycling glass packaging

    OpenAIRE

    Monica Delia DOMNICA; Leila BARDAªUC

    2015-01-01

    From the specialized literature it follows that glass packaging is not as used as other packages, but in some industries are highly needed. Following, two features of glass packaging will become important until 2017: the shape of the glass packaging and glass recycling prospects in Romania. The recycling of glass is referred to the fact that it saves energy, but also to be in compliance with the provisions indicating the allowable limit values for the quantities of lead and cadmium.

  19. Effect of leaching in Na{sub 2}O-Al{sub 2}O{sub 3}-B{sub 2}O{sub 3}-SiO{sub 2} system glass on borate anomaly

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Myeong Jeong; Lee, Byung Chul; Ryu, Bong Ki [Pusan National Univ., Pusan(Korea, Republic of); Choi, Jong Rak; Kim, Cheon Woo; Park, Jong Kil; Shin, Sang Woon; Ha, Jong Hyun; Song, Myung Jae [Korea Hydro and Nuclear Power Co., Taejon (Korea, Republic of)

    2003-07-01

    Vitrification is an attractive approach for treatment of the radioactive waste from nuclear power plants. The borosilicate glass has received major consideration as the primary waste form for the disposal of the radioactive waste. In this study, we examined Na{sub 2}O-Al{sub 2}O{sub 3}-B{sub 2}O{sub 3}-SiO{sub 2} system glass as radioactive waste glass. The quantitative analysis by ICP for leached solution has shown that the more SiO{sub 2} in glass decrease the leaching rate from the glass. It was found that higher BO{sub 4} tetrahedra structure leads to increase the chemical durability.

  20. Analyses of high level radioactive glasses and sludges at the Savannah River Site

    International Nuclear Information System (INIS)

    Reliable analyses of high level radioactive glass and sludge are necessary for successful operation of the Defense Waste Processing Facility (DWPF) at the Savannah River Site (SRS). This facility will convert the radioactive waste sludges at SRS into durable borosilicate glasses for final disposal in a geologic repository. Analyses that are crucial to DWPF operation and repository acceptance of the glass are measurement of the radioactive and nonradioactive composition of the waste sludges and final glasses and measurement of the Fe(II)/Fe(III) ratio in a vitrified sample of melter feed. These measurements are based on the remote dissolutions of the glass and sludge followed by appropriate chemical analyses. Glasses are dissolved by a peroxide fusion method and a method using HF, HNO3, H3BO3, and HCl acids where the solutions are heated in a microwave oven. The resulting solutions are analyzed by inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and atomic absorption spectroscopy (AAS) for nonradioactive elements and appropriate counting techniques for radioactive elements. Results of replicate samples of a standard simulated nuclear waste glass indicate a precision of 5% or better for the major components. The results agree well with the standard values indicating good accuracy. Results for two radioactive glasses containing actual radioactive waste are also presented. Sludges are dissolved by the Na2O2 fusion method and an aqua regia method. Analyses of replicate sludge samples indicate that the results have a precision of nominally 5% or better for the major components. Standard sludges are not available to test the accuracy of the methods; however, results of the standard glass analyzed concurrently indicate that the analyses are accurate. The two methods for the sludge are in excellent agreement indicating that they are reliable and accurate. 8 refs., 4 tabs

  1. Biological Impact of Bioactive Glasses and Their Dissolution Products.

    Science.gov (United States)

    Hoppe, Alexander; Boccaccini, Aldo R

    2015-01-01

    For many years, bioactive glasses (BGs) have been widely considered for bone tissue engineering applications due to their ability to bond to hard as well as soft tissue (a property termed bioactivity) and for their stimulating effects on bone formation. Ionic dissolution products released during the degradation of the BG matrix induce osteogenic gene expression leading to enhanced bone regeneration. Recently, adding bioactive metallic ions (e.g. boron, copper, cobalt, silver, zinc and strontium) to silicate (or phosphate and borate) glasses has emerged as a promising route for developing novel BG formulations with specific therapeutic functionalities, including antibacterial, angiogenic and osteogenic properties. The degradation behaviour of BGs can be tailored by adjusting the glass chemistry making these glass matrices potential carrier systems for controlled therapeutic ion release. This book chapter summarises the fundamental aspects of the effect of ionic dissolution products from BGs on osteogenesis and angiogenesis, whilst discussing novel BG compositions with controlled therapeutic ion release. PMID:26201273

  2. High content silicate porous glasses used for radioactive wastes storage: preparation and characterization of the spinodal decomposition

    International Nuclear Information System (INIS)

    The phase separation behavior via spinodal decomposition of two sodium borosilicate glasses has been studied having the following compositions in weight %: Glass A: 8% Na2 O - 32% B2O3 - 60% Si O2 Glass 8% B: Na2 O -27% B2 O3 - 65% Si O2. The growth of the mean size r of the minor phase microstructure has been determined as a function of both the time length (0-100 hours) and the heat treatment by analyzing temperature 580, 6000 C of the glass sample images obtained with a Scanning Electron Microscope. The results are in good agreement with the theory of Lifshitz-Slyozov which predict a growth of the minor phase microstructure via a diffusion controlled process through the insoluble phase such that r-bar = Ao t e - ΔE/R T. The activation energy ΔE and the pre-exponential factor Ao of the diffusion process were found ΔE = 58,8 kCal/mol; Ao = 8,42 x 1021 Angstrom3/h for the glass A and ΔE = 92,6 kCal/mol; Ao = 4,84 x 1029 Angstrom3/h for the glass B. The distribution curves of the microstructure size allowed to suggest for the glasses under study the most adequate heat treatments to absorbs after the leaching of the soluble phase. (author)

  3. Determination of long-lived fission products and actinides in Savannah River site HLW sludge and glass for waste acceptance

    International Nuclear Information System (INIS)

    Savannah River Site (SRS) is currently immobilizing the radioactive, caustic, high-level waste sludge in Tank 51 into a borosilicate glass for disposal in a geologic repository. A requirement for repository acceptance is that SRS report the concentrations of certain fission product and actinide radionuclides in the glass. This paper presents measurements of many of these concentrations in both Tank 51 sludge and the final glass. The radionuclides were measured by inductively coupled plasma - mass spectrometry and α, β, and γ counting methods. Examples of the radionuclides are Sr-90, Cs-137, U-238, Pu-239, and Cm-244. Concentrations in the glass are 3.1 times lower due to dilution of the sludge with a nonradioactive glass forming frit in the vitrification process. Results also indicated that in both the sludge and glass the relative concentrations of the long lived fission products insoluble in caustic area in proportion to their yields from the fission of U-235 in the SRS reactors. This allowed the calculation of a fission yield scaling factor. This factor in addition to the sludge dilution factor can be used to estimate concentrations of waste acceptance radionuclides that cannot be measured in the glass

  4. Determination of long-lived fission products and actinides in Savannah River Site HLW sludge and glass for waste acceptance

    International Nuclear Information System (INIS)

    Savannah River Site (SRS) is immobilizing the radioactive, high-level waste sludge in Tank 51 into a borosilicate glass for disposal in a geologic repository. A requirement for repository acceptance is that SRS report the concentrations of certain fission product and actinide radionuclides in the glass. This paper presents measurements of many of these concentrations in both Tank 51 sludge and the final glass. The radionuclides were measured by inductively coupled plasma mass spectrometry and α, β, and γ counting methods. Examples of the radionuclides are 90Sr, 137Cs, 238U and , 239Pu. Concentrations in the glass are 3.1 times lower due to dilution of the sludge with a nonradioactive glass forming frit in the vitrification process. Results also indicated that in both the sludge and glass the relative concentrations of the long lived fission products insoluble in caustic are in proportion to their yields from the fission of 235U waste in the SRS reactors. This allowed the calculation of a fission yield scaling factor. This factor in addition to the sludge dilution factor can be used to estimate concentrations of waste acceptance radionuclides that cannot be measured in the glass. Examples of these radionuclides are 79Se, 93Zr, and 107Pd. (author)

  5. [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.

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

    International Nuclear Information System (INIS)

    Long half life and easy availability from high level wastes make 137Cesium most economical radiation source. High level liquid waste processing for 137 Cesium removal has become easier due to development of Cesium specific granulated ammonium molybdophosphate (AMP) composite. In such applications, resulting spent composite AMP itself represents high active solid waste and immobilization of these materials in cement may not be acceptable. Studies on immobilization of 137Cs loaded AMP were taken up in order to achieve twin goals of increasing safety and minimizing processing costs of the final matrix. Studies indicated that phosphate modified sodium borosilicate SPNM glasses prepared under usual oxidizing conditions are not suitable for immobilization of 137Cs loaded on AMP .Phosphate glasses containing Na2O, P2O5, B2O3, Fe2O3, Al2O3 and SiO2 as major constituents are capable of incorporating 6 to 8 % AMP. The Normalized Leach rates of these glasses for sodium, cesium, boron and silica are 10-4 to 10-6 gm/cm2/day which are comparable to or better than those reported for NBS glasses incorporating HLW. Homogeneity of the final matrix was confirmed by x-ray diffraction analysis. Further studies on characterization of these glasses would establish their acceptability. (author)

  7. Radiation stability test on multiphase glass ceramic and crystalline ceramic waste forms

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Ming; Kossoy, Anna; Jarvinen, G. D.; Crum, Jarrod V.; Turo, Laura A.; Riley, Brian J.; Brinkman, Kyle; Fox, Kevin M.; Amoroso, Jake; Marra, James C.

    2014-02-03

    A radiation stability study was performed on glass ceramic and crystalline ceramic waste forms. These materials are candidate host materials for immobilizing alkali/alkaline earth (Cs/Sr-CS) + lanthanide (LN) + transition metal (TM) fission product waste streams from nuclear fuel reprocessing. In this study, glass ceramics were fabricated using a borosilicate glass as a matrix in which to incorporate CS/LN/TM combined waste streams. The major phases in these multiphase materials are powellite, oxyaptite, pollucite, celsian, and durable residual glass phases. Al2O3 and TiO2 were combined with these waste components to produce multiphase crystalline ceramics containing hollandite-type phases, perovskites, pyrochlores and other minor metal titanate phases. For the radiation stability test, selected glass ceramic and crystalline ceramic samples were exposed to different irradiation environments including low fluxes of high-energy (~1–5 MeV) protons and alpha particles generated by an ion accelerator, high fluxes of low-energy (hundreds of keV) krypton particles generated by an ion implanter, and in-situ electron irradiations in a transmission electron microscope. These irradiation experiments were performed to simulate self-radiation effects in a waste form. Ion irradiation-induced microstructural modifications were examined using X-ray diffraction and transmission electron microscopy. Our preliminary results reveal different radiation tolerance in different crystalline phases under various radiation damage environments. However, their stability may be rate dependent which may limit the waste loading that can be achieved.

  8. Radiation stability test on multiphase glass ceramic and crystalline ceramic waste forms

    Science.gov (United States)

    Tang, Ming; Kossoy, Anna; Jarvinen, Gordon; Crum, Jarrod; Turo, Laura; Riley, Brian; Brinkman, Kyle; Fox, Kevin; Amoroso, Jake; Marra, James

    2014-05-01

    A radiation stability study was performed on glass ceramic and crystalline ceramic waste forms. These materials are candidate host materials for immobilizing alkali/alkaline earth (Cs/Sr-CS) + lanthanide (LN) + transition metal (TM) fission product waste streams from nuclear fuel reprocessing. In this study, glass ceramics were fabricated using a borosilicate glass as a matrix in which to incorporate CS/LN/TM combined waste streams. The major phases in these multiphase materials are powellite, oxyaptite, pollucite, celsian, and durable residual glass phases. Al2O3 and TiO2 were combined with these waste components to produce multiphase crystalline ceramics containing hollandite-type phases, perovskites, pyrochlores and other minor metal titanate phases. For the radiation stability test, selected glass ceramic and crystalline ceramic samples were exposed to different irradiation environments including low fluxes of high-energy (∼1-5 MeV) protons and alpha particles generated by an ion accelerator, high fluxes of low-energy (hundreds of keV) krypton particles generated by an ion implanter, and in-situ electron irradiations in a transmission electron microscope. These irradiation experiments were performed to simulate self-radiation effects in a waste form. Ion irradiation-induced microstructural modifications were examined using X-ray diffraction and transmission electron microscopy. Our preliminary results reveal different radiation tolerance in different crystalline phases under various radiation damage environments. However, their stability may be rate dependent which may limit the waste loading that can be achieved.

  9. Effects of radionuclide decay on waste glass behavior: A critical review

    Energy Technology Data Exchange (ETDEWEB)

    Wronkiewicz, D.J.

    1993-12-01

    This paper is an extension of a chapter in an earlier report [1] that provides an updated review on the status of radiation damage problems in nuclear waste glasses. This report will focus on radiation effects on vitrified borosilicate nuclear waste glasses under conditions expected in the proposed Yucca mountain repository. Radiation effects on high-level waste glasses and their surrounding repository environment are important considerations for radionuclide immobilization because of the potential to alter the glass stability and thereby influence the radionuclide retentive properties of this waste form. The influence of radionuclide decay on vitrified nuclear waste may be manifested by several changes, including volume, stored energy, structure, microstructure, mechanical properties, and phase separation. Radiation may also affect the composition of aqueous fluids and atmospheric gases in relatively close proximity to the waste form. What is important to the radionuclide retentive properties of the repository is how these radiation effects collectively or individually influence the durability and radionuclide release from the glass in the event of liquid water contact.

  10. Polyphase ceramic and glass-ceramic forms for immobilizing ICPP high-level nuclear waste

    International Nuclear Information System (INIS)

    Polyphase ceramic and glass-ceramic forms have been consolidated from simulated Idaho Chemical Processing Plant wastes by hot isostatic pressing calcined waste and chemical additives by 10000C or less. The ceramic forms can contain over 70 wt% waste with densities ranging from 3.5 to 3.85 g/cm3, depending upon the formulation. Major phases are CaF2, CaZrTi207, CaTiO3, monoclinic ZrO2, and amorphous intergranular material. The relative fraction of the phases is a function of the chemical additives (TiO2, CaO, and SiO2) and consolidation temperature. Zirconolite, the major actinide host, makes the ceramic forms extremely leach resistant for the actinide simulant U238. The amorphous phase controls the leach performance for Sr and Cs which is improved by the addition of SiO2. Glass-ceramic forms were also consolidated by HIP at waste loadings of 30 to 70 wt% with densities of 2.73 to 3.1 g/cm3 using Exxon 127 borosilicate glass frit. The glass-ceramic forms contain crystalline CaF2, Al203, and ZrSi04 (zircon) in a glass matrix. Natural mineral zircon is a stable host for 4+ valent actinides. 17 references, 3 figures, 5 tables

  11. 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.

  12. Effects of radionuclide decay on waste glass behavior: A critical review

    International Nuclear Information System (INIS)

    This paper is an extension of a chapter in an earlier report [1] that provides an updated review on the status of radiation damage problems in nuclear waste glasses. This report will focus on radiation effects on vitrified borosilicate nuclear waste glasses under conditions expected in the proposed Yucca mountain repository. Radiation effects on high-level waste glasses and their surrounding repository environment are important considerations for radionuclide immobilization because of the potential to alter the glass stability and thereby influence the radionuclide retentive properties of this waste form. The influence of radionuclide decay on vitrified nuclear waste may be manifested by several changes, including volume, stored energy, structure, microstructure, mechanical properties, and phase separation. Radiation may also affect the composition of aqueous fluids and atmospheric gases in relatively close proximity to the waste form. What is important to the radionuclide retentive properties of the repository is how these radiation effects collectively or individually influence the durability and radionuclide release from the glass in the event of liquid water contact

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. Properties of the pultruded composites reinforced with glass fibers

    OpenAIRE

    Srebrenkoska, Vineta; Luceski, Nikola; Bogoeva-Gaceva, Gordana

    2004-01-01

    The paper presents the pultrusion technology with a special overview of the properties and benefits of usage of pultruded products. Composites based on polyester, epoxy and vinylester resins reinforced with glass fibers, are produced by pultrusion process. The physical, mechanical and thermal properties of the composites are analyzed. The test results has shown that the main advantage of pultruded composites is the possibility of tailoring of their properties by changing the ratio of the comp...

  18. Dissolution of oxide glasses: A process driven by surface generation

    International Nuclear Information System (INIS)

    Grazing incident X-ray scattering (GISAXS) has been used to study in situ the alteration of sodium borosilicate glass monoliths in water. The treatment used to extract the pore volume and the specific surface from the disordered porous media is first introduced and validated by comparing results in other geometries (powders). In the same time, the plane geometry of the GISAXS experiments allows an accurate measurement of the alteration depth. It is shown that the alteration results in the formation of a porous layer, the thickness and porosity of which can be quantitatively assigned to the difference of dissolution between silicon on the one side and boron and sodium on the other. The in situ experiments reveal that a large specific surface develops very rapidly in the layer. No gradient of structure throughout the depth of the altered layer could be observed. Introduction of zirconium promotes a strong increase of the glass durability but increases the specific surface area of the altered layer. (authors)

  19. 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.

  20. Structural Roles of Boron and Silicon in the CaO-SiO2-B2O3 Glasses Using FTIR, Raman, and NMR Spectroscopy

    Science.gov (United States)

    Sun, Yongqi; Zhang, Zuotai

    2015-08-01

    The present paper provided not only a deep insight of network structures of borosilicate glasses but also a basic linkage between the network structures and the viscous flow behaviors of many borosilicate melts. The structures of a ternary system of CaO-SiO2-B2O3 were characterized using Fourier transformation infrared (FTIR), Raman, and magic angular spinning nuclear magnetic resonance spectroscopy. The results of FTIR and Raman spectra complementally verified that the main Si-related units were SiO4 tetrahedral with zero, one, two, and three bridging oxygens [Q0(Si), Q1(Si), Q2(Si), and Q3(Si)]; the added B2O3 leaded to an increase of Q3(Si) at the cost of Q0(Si) and Q2(Si), and therefore an increasing degree of polymerization (DOP) was induced. Additionally, the 11B NMR spectra demonstrated that the dominant B-related groups were BO3 trigonal and BO4 tetrahedral, while an increasing B2O3 content facilitated the existence of BO4 tetrahedral. Moreover, there was a competitive effect between the enhanced DOP and the presence of BO3 trigonal and BO4 tetrahedral in the networks, which therefore resulted in a decreasing viscosity of borosilicate melts in numerous studies.

  1. 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.

  2. 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.

  3. 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

  4. Tailoring complex optical fields via anisotropic microstructures (Presentation Recording)

    Science.gov (United States)

    Lu, Yan-Qing; Hu, Wei; Cui, Guo-Xin

    2015-10-01

    In recent years, complex optical fields with spatially inhomogeneous phases, polarizations and optical singularities have drawn many research interests. Many novel effects have been predicted and demonstrated for light beams with these unconventional states in both linear and nonlinear optics regimes. Although local optical phase could be controlled directly or through hologram structures in isotropic materials such as glasses, optical anisotropy is still required for manipulating polarization states and wavelengths. The anisotropy could be either intrinsic such as in crystals/liquid crystals (LCs) or the induced birefringence from dielectric or metallic structures. In this talk, we will briefly review some of our attempts in tailoring complex optical fields via anisotropic microstructures. We developed a micro-photo-patterning system that could generate complex micro-images then further guides the arbitrary local LC directors. Due to the electro-optically (EO) tunable anisotropy of LC, various reconfigurable complex optical fields such as optical vortices (OVs), multiplexed OVs, OV array, Airy beams and vector beams are obtained. Different LC modes such as homogeneous alignment nematic, hybrid alignment nematic and even blue phase LCs are adopted to optimize the static and dynamic beam characteristics depending on application circumstances. We are also trying to extend our approaches to new wavelength bands, such as mid-infrared and even THz ranges. Some preliminary results are obtained. In addition, based on our recently developed local poling techniques for ferroelectric crystals, we will also discuss and demonstrate the nonlinear complex optical field conversion in Lithium Niobate wafers with patterned ferroelectric domain structures.

  5. 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

  6. Growth and properties of CdS/CdTe heterojunctions on soda lime glass substrates

    International Nuclear Information System (INIS)

    Polycrystalline thin films of CdTe grown on glass/SnO2/CdS substrates are studied using X-ray diffraction, atomic force microscopy, and time resolved photoluminescence decay techniques. CdS films were deposited by chemical solution. CdTe films were grown by close-spaced sublimation at substrate temperatures between 475--625 degree C. CdTe thin films deposited at temperatures higher than 525 degree C show preferential orientation in the left-angle 111 right-angle direction. The Grain size of the films increases with substrate temperature and the films are faceted for all the temperatures. The PL decay constant increases with substrate temperature up to 575 degree C for as-deposited films on soda-lime substrates. Films on borosilicate substrates show an increase up to the highest temperature used (625 degree C). There is systematic increase in the PL decay constant after CdCl2 heat treatment, and the range of values is 1--1.5 nsec for soda-lime samples and 1--2 nsec for borosilicate samples

  7. 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

  8. 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.

  9. Betatron radiation from density tailored plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Ta Phuoc, Kim; Esarey, E.; Leurent, V.; Cormier-Michel, E.; Geddes, C.G.R.; Schroeder, C.B.; Rousse, A.; Leemans, W.P.

    2009-04-11

    In laser wakefield accelerators, electron motion is driven by intense forces that depend on the plasma density. Transverse oscillations in the accelerated electron orbits produce betatron radiation. The electron motion and the resulting betatron radiation spectrum can therefore be controlled by shaping the plasma density along the orbit of the electrons. Here, a method based on the use of a plasma with a longitudinal density variation (density depression or step) is proposed to increase the transverse oscillation amplitude and the energy of the electrons accelerated in a wakefield cavity. For fixed laser parameters, by appropriately tailoring the plasma profile, the betatron radiation emitted by these electrons is significantly increased in both flux and energy.

  10. Tailored vacuum chambers for ac magnets

    International Nuclear Information System (INIS)

    The proposed LAMPF-II accelerator has a 60-Hz booster synchrotron and a 3-Hz main ring. To provide a vacuum enclosure inside the magnets with low eddy-current losses and minimal field distortion, yet capable of carrying rf image currents and providing beam stabilization, we propose an innovative combination pipe. Structurally, the enclosure is high-purity alumina ceramic, which is strong, radiation resistant, and has good vacuum properties. Applied to the chamber are thin, spaced, silver conductors using adapted thick-film technology. The conductor design can be tailored to the stabilization requirements, for example, longitudinal conductors for image currents, circumferential for transverse stabilization. The inside of the chamber has a thin, resistive coating to avoid charge build-up. The overall 60-Hz power loss is less than 100 W/m

  11. 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.

  12. 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.

  13. 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.

  14. The behavior of silicon and boron in the surface of corroded nuclear waste glasses: an EFTEM study

    International Nuclear Information System (INIS)

    Using electron energy-loss filtered transmission electron microscopy (EFTEM), we have observed the formation of silicon-rich zones on the corroded surface of a West Valley (WV6) glass. This layer is approximately 100-200 nm thick and is directly underneath a precipitated smectite clay layer. Under conventional (C)TEM illumination, this layer is invisible; indeed, more commonly used analytical techniques, such as x-ray energy dispersive spectroscopy (EDS), have failed to describe fully the localized changes in the boron and silicon contents across this region. Similar silicon-rich and boron-depleted zones were not found on corroded Savannah River Laboratory (SRL) borosilicate glasses, including SRL-EA and SRL-51, although they possessed similar-looking clay layers. This study demonstrates a new tool for examining the corroded surfaces of materials

  15. 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

  16. 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.

  17. 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.

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

    International Nuclear Information System (INIS)

    This paper discusses two standard chemical durability tests, the static leach test (MCC-1) and product consistency test (PCT), which were conducted on simulated borosilicate glasses that encompass the expected range of compositions to be produced in the Hanford Waste Vitrification Plant. 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 Al2O3, moderately increased by addition of ZrO2 and SiO2, and decreased by addition of Li2O, Na2O, B2O3, and MgO. Additions of CaO and Fe2O3 reduce MCC-1 durability and produce a moderately positive (CaO) or indifferent (Fe2O3) effect on PCT durability. The first-order models show a statistically significant lack-of-fit, which is 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

  19. 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

  20. 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...

  1. 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.

  2. 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.

  3. 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

  4. Up- and down-conversion luminescence in the oxyfluoride glass ceramics containing Ba2+1.5xYb1−xF7:Tb3+ nanocrystals

    International Nuclear Information System (INIS)

    Transparent oxyfluoride borosilicate glass ceramics containing Ba2+1.5xYb1−xF7:Tb3+ nanocrystals were successfully prepared by a melt-quenching method with subsequent heat treatment. The precipitated crystalline phase in the glass matrix changed gradually from BaF2 to Ba2+1.5xYb1−xF7 with the increase of YbF3 content, which was confirmed by the results of XRD, HRTEM and EDX measurements. The ultraviolet and visible up-conversion and near-infrared quantum cutting down-conversion emissions were observed and interpreted. These materials could be used to modify the solar spectrum and enhance the silicon solar cell efficiency by the up-conversion and down-conversion luminescence of Tb3+–Yb3+ couples in the oxyfluoride borosilicate glass ceramics. -- Highlights: ► Oxyfluoride glass ceramics containing Ba2+1.5xYb1−xF7:Tb nanocrystals were prepared. ► The precipitated crystal phase changed from BaF2 to Ba2+1.5xYb1−xF7. ► Strong up-conversion and down-conversion emissions were observed and interpreted.

  5. Up- and down-conversion luminescence in the oxyfluoride glass ceramics containing Ba{sub 2+1.5x}Yb{sub 1-x}F{sub 7}:Tb{sup 3+} nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Xin, Fengxia [College of Materials Science and Engineering, China Jiliang University, Hangzhou 310018 (China); Zhao, Shilong, E-mail: shilong_zhao@hotmail.com [College of Materials Science and Engineering, China Jiliang University, Hangzhou 310018 (China); Jia, Guohua; Huang, Lihui; Deng, Degang; Wang, Huanping [College of Materials Science and Engineering, China Jiliang University, Hangzhou 310018 (China); Xu, Shiqing, E-mail: sxucjlu@hotmail.com [College of Materials Science and Engineering, China Jiliang University, Hangzhou 310018 (China)

    2012-11-15

    Transparent oxyfluoride borosilicate glass ceramics containing Ba{sub 2+1.5x}Yb{sub 1-x}F{sub 7}:Tb{sup 3+} nanocrystals were successfully prepared by a melt-quenching method with subsequent heat treatment. The precipitated crystalline phase in the glass matrix changed gradually from BaF{sub 2} to Ba{sub 2+1.5x}Yb{sub 1-x}F{sub 7} with the increase of YbF{sub 3} content, which was confirmed by the results of XRD, HRTEM and EDX measurements. The ultraviolet and visible up-conversion and near-infrared quantum cutting down-conversion emissions were observed and interpreted. These materials could be used to modify the solar spectrum and enhance the silicon solar cell efficiency by the up-conversion and down-conversion luminescence of Tb{sup 3+}-Yb{sup 3+} couples in the oxyfluoride borosilicate glass ceramics. -- Highlights: Black-Right-Pointing-Pointer Oxyfluoride glass ceramics containing Ba{sub 2+1.5x}Yb{sub 1-x}F{sub 7}:Tb nanocrystals were prepared. Black-Right-Pointing-Pointer The precipitated crystal phase changed from BaF{sub 2} to Ba{sub 2+1.5x}Yb{sub 1-x}F{sub 7}. Black-Right-Pointing-Pointer Strong up-conversion and down-conversion emissions were observed and interpreted.

  6. 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.

  7. Tailorable software architectures in the accelerator control system environment

    Science.gov (United States)

    Mejuev, Igor; Kumagai, Akira; Kadokura, Eiichi

    2001-08-01

    Tailoring is further evolution of an application after deployment in order to adapt it to requirements that were not accounted for in the original design. End-user tailorability has been extensively researched in applied computer science from HCl and software engineering perspectives. Tailorability allows coping with flexibility requirements, decreasing maintenance and development costs of software products. In general, dynamic or diverse software requirements constitute the need for implementing end-user tailorability in computer systems. In accelerator physics research the factor of dynamic requirements is especially important, due to frequent software and hardware modifications resulting in correspondingly high upgrade and maintenance costs. In this work we introduce the results of feasibility study on implementing end-user tailorability in the software for accelerator control system, considering the design and implementation of distributed monitoring application for 12 GeV KEK Proton Synchrotron as an example. The software prototypes used in this work are based on a generic tailoring platform (VEDICI), which allows decoupling of tailoring interfaces and runtime components. While representing a reusable application-independent framework, VEDICI can be potentially applied for tailoring of arbitrary compositional Web-based applications.

  8. 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

  9. 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 appl...

  10. 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.

  11. Mechanically reinforced glass beams

    DEFF Research Database (Denmark)

    Nielsen, Jens Henrik; Olesen, John Forbes

    2007-01-01

    The use of glass as a load carrying material in structural elements is rarely seen even though glass is a popular material for many architects. This is owed to the unreliable and low tensile strength, which is due to surface flaws and high brittleness of the material. These properties lead...... 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...... laminated float glass beam is constructed and tested in four-point bending. The beam consist of 4 layers of glass laminated together with a slack steel band glued onto the bottom face of the beam. The glass parts of the tested beams are \\SI{1700}{mm} long and \\SI{100}{mm} high, and the total width of one...

  12. 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.).

  13. 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....

  14. 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

  15. 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.

  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. 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. Toward Tailored All-Spin Molecular Devices.

    Science.gov (United States)

    Bazarnik, Maciej; Bugenhagen, Bernhard; Elsebach, Micha; Sierda, Emil; Frank, Annika; Prosenc, Marc H; Wiesendanger, Roland

    2016-01-13

    Molecular based spintronic devices offer great potential for future energy-efficient information technology as they combine ultimately small size, high-speed operation, and low-power consumption. Recent developments in combining atom-by-atom assembly with spin-sensitive imaging and characterization at the atomic level have led to a first prototype of an all-spin atomic-scale logic device, but the very low working temperature limits its application. Here, we show that a more stable spintronic device could be achieved using tailored Co-Salophene based molecular building blocks, combined with in situ electrospray deposition under ultrahigh vacuum conditions as well as control of the surface-confined molecular assembly at the nanometer scale. In particular, we describe the tools to build a molecular, strongly bonded device structure from paramagnetic molecular building blocks including spin-wires, gates, and tails. Such molecular device concepts offer the advantage of inherent parallel fabrication based on molecular self-assembly as well as an order of magnitude higher operation temperatures due to enhanced energy scales of covalent through-bond linkage of basic molecular units compared to substrate-mediated coupling schemes employing indirect exchange coupling between individual adsorbed magnetic atoms on surfaces. PMID:26704349

  20. Facile Preparation of Optically Tailored Hybrid Nanocomposite

    Directory of Open Access Journals (Sweden)

    Susana Fernández de Ávila

    2014-01-01

    Full Text Available Lead sulfide nanoparticles (PbS NPs have been synthesized directly in poly[2-methoxy-5-(3′,7′-dimethyloctyloxy-1,4-phenylenevinylene] (MDMO-PPV semiconducting polymer by a simple low temperature method. Hybrid solutions with different concentrations of PbS with respect to the polymer have been prepared and characterized first in solution and then as thin film nanocomposites deposited on quartz substrates by spin coating. Quenching of photoluminescence emission is observed both in solutions and thin films when the ratio of PbS NPs increases with respect to the polymer, suggesting the occurrence of Dexter energy transfer from the polymer to the PbS NPs. Optical absorption is markedly increased for hybrid solutions compared to pure polymer. In thin nanocomposite films an enhancement of absorbance is observed with increasing PbS NPs concentration, which is more pronounced below 400 nm. The reported results could lead to the development of a method for tailoring the optical response of devices based on PbS NP-polymer nanocomposite by controlling the PbS NP concentration inside the polymer matrix.

  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. Drugstore Reading Glasses

    Science.gov (United States)

    Erlichson, Herman

    2006-03-01

    The occasion for this paper was my reading of a paper in the February 2005 issue of TPT. As one gets older the near point of the eye begins to recede.2 This is called presbyopia.3 An alternative to purchasing glasses from an optometrist is to purchase an inexpensive pair of reading glasses in a pharmacy. The pharmacy has these glasses ordered by diopters corresponding to the strength of the lens needed for a particular presbyopic eye. The glasses are, of course, not available for myopic eyes.

  3. Tailoring dietary approaches for weight loss.

    Science.gov (United States)

    Gardner, C D

    2012-07-01

    Although the 'Low-Fat' diet was the predominant public health recommendation for weight loss and weight control for the past several decades, the obesity epidemic continued to grow during this time period. An alternative 'low-carbohydrate' (Low-Carb) approach, although originally dismissed and even vilified, was comparatively tested in a series of studies over the past decade, and has been found in general to be as effective, if not more, as the Low-Fat approach for weight loss and for several related metabolic health measures. From a glass half full perspective, this suggests that there is more than one choice for a dietary approach to lose weight, and that Low-Fat and Low-Carb diets may be equally effective. From a glass half empty perspective, the average amount of weight lost on either of these two dietary approaches under the conditions studied, particularly when followed beyond 1 year, has been modest at best and negligible at worst, suggesting that the two approaches may be equally ineffective. One could resign themselves at this point to focusing on calories and energy intake restriction, regardless of macronutrient distributions. However, before throwing out the half-glass of water, it is worthwhile to consider that focusing on average results may mask important subgroup successes and failures. In all weight-loss studies, without exception, the range of individual differences in weight change within any particular diet groups is orders of magnitude greater than the average group differences between diet groups. Several studies have now reported that adults with greater insulin resistance are more successful with weight loss on a lower-carbohydrate diet compared with a lower-fat diet, whereas adults with greater insulin sensitivity are equally or more successful with weight loss on a lower-fat diet compared with a lower-carbohydrate diet. Other preliminary findings suggest that there may be some promise with matching individuals with certain genotypes to

  4. 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.

  5. The determination of the Fe sup 2+ /Fe sup 3+ ratio in simulated nuclear waste glass by ion chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Jantzen, C.M.

    1990-10-01

    Liquid high-level nuclear waste will be immobilized at the Savannah River Site (SRS) by vitrification in borosilicate glass in the Defense Waste Processing Facility (DWPF). In this facility, control of the oxidation/reduction (redox) equilibrium in the glass melter is critical for processing of the nuclear waste. Therefore, the development of a rapid and reliable analytical method for the determination of the redox equilibrium is of considerable interest. Redox has been determined by measuring the ratio of ferrous to ferric ions in the glass melt. Two analytical techniques for glass redox measurement have been investigated for the DWPF: Mossbauer Spectroscopy which may be subject to interferences from the radiation in actual waste, and a rapid and simple chemical dissolution/spectrophotometric technique. Comparisons of these techniques have been made at several laboratories including Clemson University. In the study attached, the determination of the redox ratio by Ion Chromatography (IC) was investigated as a potential new technology. Clemson University performed IC analyses on the same glasses as previously examined by wet chemical and Mossbauer techniques. Results from all three techniques were highly correlated and IC was reported to be a promising new technology for redox measurement. 19 refs., 19 figs., 5 tabs.

  6. X-ray absorption fine structure of aged, Pu-doped glass and ceramic waste forms

    Science.gov (United States)

    Hess, N. J.; Weber, W. J.; Conradson, S. D.

    1998-04-01

    X-ray absorption spectroscopic (XAS) studies were performed on three compositionally identical, Pu-doped, borosilicate glasses prepared 15 years ago at different α-activities by varying the 239Pu/ 238Pu isotopic ratio. The resulting α-activities ranged from 1.9×10 7 to 4.2×10 9 Bq/g and have current, accumulated doses between 8.8×10 15 to 1.9×10 18 α-decays/g. Two ceramic, polycrystalline zircon (ZrSiO 4) samples prepared 16 years ago with 10.0 wt% Pu was also investigated. Varying the 239Pu/ 238Pu isotopic ratio in these samples resulted in α-activities of 2.5×10 8 and 5.6×10 10 Bq/g and current, accumulated doses of 1.2×10 17 and 2.8×10 19 α-decays/g. The multicomponent composition of the waste forms permitted XAS investigations at six absorption edges for the borosilicate glass and at three absorption edges for the polycrystalline zircons. For both waste forms, analysis of extended X-ray absorption fine structure (EXAFS) and X-ray absorption near edge structure (XANES) spectra indicates that the local environment around the cations exhibits different degrees of disorder as a result of the accumulated α-decay dose. In general, cations with short cation-oxygen bonds show little effect from self-radiation whereas cations with long cation-oxygen bonds show a greater degree of disorder with accumulated α-decay dose.

  7. An efficient method for supercontinuum generation in dispersion-tailored Lead-silicate fiber taper

    Science.gov (United States)

    Chen, Z.; Ma, S.; Dutta, N. K.

    2010-08-01

    In this paper we theoretically study the broadband mid-IR supercontinuum generation (SCG) in a lead-silicate microstructured fiber (the glass for simulation is SF57). The total dispersion of the fiber can be tailored by changing the core diameter of the fiber so that dispersion profiles with two zero dispersion wavelengths (ZDWs) can be obtained. Numerical simulations of the SCG process in a 4 cm long SF57 fiber/fiber taper seeded by femto-second pulses at telecommunications wavelength of 1.55 µm are presented. The results show that a fiber taper features a continuous shift of the longer zero dispersion wavelength. This extends the generated continuum to a longer wavelength region compared to fibers with fixed ZDWs. The phase-matching condition (PMC) is continuously modified in the fiber taper and the bandwidth of the generated dispersive waves (DWs) is significantly broadened.

  8. 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.

  9. Thin tailored composite wing for civil tiltrotor

    Science.gov (United States)

    Rais-Rohani, Masoud

    1994-01-01

    The tiltrotor aircraft is a flight vehicle which combines the efficient low speed (i.e., take-off, landing, and hover) characteristics of a helicopter with the efficient cruise speed of a turboprop airplane. A well-known example of such vehicle is the Bell-Boeing V-22 Osprey. The high cruise speed and range constraints placed on the civil tiltrotor require a relatively thin wing to increase the drag-divergence Mach number which translates into lower compressibility drag. It is required to reduce the wing maximum thickness-to-chord ratio t/c from 23% (i.e., V-22 wing) to 18%. While a reduction in wing thickness results in improved aerodynamic efficiency, it has an adverse effect on the wing structure and it tends to reduce structural stiffness. If ignored, the reduction in wing stiffness leads to susceptibility to aeroelastic and dynamic instabilities which may consequently cause a catastrophic failure. By taking advantage of the directional stiffness characteristics of composite materials the wing structure may be tailored to have the necessary stiffness, at a lower thickness, while keeping the weight low. The goal of this study is to design a wing structure for minimum weight subject to structural, dynamic and aeroelastic constraints. The structural constraints are in terms of strength and buckling allowables. The dynamic constraints are in terms of wing natural frequencies in vertical and horizontal bending and torsion. The aeroelastic constraints are in terms of frequency placement of the wing structure relative to those of the rotor system. The wing-rotor-pylon aeroelastic and dynamic interactions are limited in this design study by holding the cruise speed, rotor-pylon system, and wing geometric attributes fixed. To assure that the wing-rotor stability margins are maintained a more rigorous analysis based on a detailed model of the rotor system will need to ensue following the design study. The skin-stringer-rib type architecture is used for the wing

  10. 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...

  11. 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

  12. Precise tailoring of acoustic velocity in optical fibers by hydrogenation and UV exposure.

    Science.gov (United States)

    Kong, Fanting; Dong, Liang

    2012-12-01

    Tailoring of acoustic properties in solids has many potential applications in both acoustics, i.e. acoustic gratings and waveguides, and photon-phonon interactions, i.e. stimulated Brillouin scattering (SBS). One immediate application is in the area of SBS suppression in optical fibers. We demonstrate, for the first time, a post-processing technique where hydrogen is diffused in to a fiber core and then locally and permanently bonded to core glass by a subsequent UV exposure. It is discovered that local acoustic velocity can be altered by as much as ~2% this way, with strong potential for much further improvements with an increased hydrogen pressure. It is also found that the large change in acoustic velocity is primarily due to a reduction in bulk modulus, possibly as a result of network bonds being broken up by the addition of OH bonds. It is possible to use this technique to precisely tailor acoustic velocity along a fiber for more optimized SBS suppression in a fiber amplifier. Change in Brillouin Stokes frequency of ~320MHz at 1.064μm was observed. PMID:23262726

  13. 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

  14. 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…

  15. 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.)

  16. Glasses for Children

    Science.gov (United States)

    ... difficulties in the classroom. Most children who have difficulty with reading do not need glasses, but this can be ... have had cataract surgery usually need bifocals or reading glasses. Will ... normal vision development can be adversely affected. What are some things ...

  17. 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.

  18. 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

  19. Biocorrosion of Archaeological Glass

    OpenAIRE

    Shelley, William L.

    2016-01-01

    This research investigates the physical manifestation and chemical mechanisms andprocesses of biologically-induced corrosion of archaeological glass. Archaeological glasssamples from Greece and Cyprus suspected to have undergone biocorrosion wereanalyzed to characterize the composition and surface topography and to determine thedifference in the chemistry and microstructure between the glass surface and the bulk.Microscopic and analytical techniques employed include digital microscopy, polari...

  20. 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 aim was to compare the effectiveness of untailored text messages for smoking cessation to tailored text messages delivered at a higher frequency. From February 2007 to August 2009, 2030 users of an internet-based smoking cessation program with optional text message support aged 15-25 years were...... consecutively randomized to versions of the program that offered either tailored or untailored text messages. Thirty-day point abstinence from smoking was measured self-reportedly at 12-months follow-up. Response rates were 36.3% and 38.1% in the tailored and untailored group, respectively. We analyzed...

  1. USACE FUSRAP Maywood Team Identifies Challenges and Initiates Alternate Solutions Relating to the Radiochemical Analysis of Borosilicate Fiber Filters for Isotopes of Uranium and Thorium

    International Nuclear Information System (INIS)

    This presentation discusses the primary purposes of particulate radionuclide air monitoring at the US Army Corps of Engineers (USACE) Formerly Utilized Sites Remediation Program (FUSRAP) Maywood Superfund Site (FMSS), the challenges encountered by the team when standard radiochemistry analytical methods are attempted on borosilicate fiber filter samples, the surrogate evaluations used when sample specific isotopic analysis is unsuccessful, and current strategies for overcoming radiochemistry method deficiencies. Typical borosilicate fiber filter sample preparation procedures including tracer spike and digestion methods and their impact on uranium and thorium data quality are of particular interest. Analytes discussed include isotopic uranium (U-234, U-235, and U-238) and isotopic thorium (Th-228, Th-230, and Th-232). Efforts to obtain reproducible and defensible results also included discussions with commercial laboratory radiochemistry managers as well as industry experts. This presentation may benefit sites that use similar sample collection and analysis techniques, utilize data that may have unidentified method-related issues with diminished data quality, or have a similar isotopic signature. (authors)

  2. Development of Glass and Ceramic Matrices for the Immobilization of High-level Radioactive Waste from Fast Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Govindan Kutty, K.V.; Kitheri, Joseph; Asuvathraman, R.; Raja Madhavan, R.; Vasudeva Rao, P.R.; Baldev, Raj [Liquid Metals And Structural Chemistry Division, Indira Gandhi Centre For Atomic Research - IGCAR, Kalpakkam, Tamil Nadu 603 102 (India)

    2009-06-15

    Borosilicate glass is a favoured matrix worldwide for the immobilization of high-level waste (HLW). The HLW from the reprocessing of fast reactor fuels contains higher concentrations of actinide elements and noble metals than that from thermal reactors. These elements have poor solubility in borosilicate glass, leading to phase segregation and consequent loss of chemical durability. Alternate glass and crystalline ceramic matrices thus need to be developed for the long-term disposal of fast reactor HLW. In this context, we have undertaken work on simulated waste forms based on three different systems, viz., iron phosphate glass (IPG), SYNROC, and monazites. IPG is known to be a versatile host matrix for radioactive wastes. An IPG waste form with 20 wt% simulated HLW expected from the FBTR after a burnup of 150 GWD/T, was found to form readily at 1323 K in air. The glass transition temperature of the waste-loaded glass was found to be similar to that of bare IPG. The ease of glass formation and favourable physico-chemical properties make IPG a candidate matrix for fixing radioactive wastes of fast reactor origin. Among the crystalline ceramic matrices for HLW immobilization, SYNROC is a well known system. The flexibility of the conventional titanate phase assemblage to incorporate fast reactor wastes was investigated. SYNROC precursor powders were synthesized using an inexpensive nano-anatase reagent as the main ingredient. High-density simulated waste forms were then fabricated by hot pressing or hot isostatic pressing at 1373-1473 K. Monoliths of near-theoretical density were obtained, and thermophysical and chemical durability measurements were carried out on them. In contrast to the poly-phase SYNROC, monazite is known to be a single-phase orthophosphate waste form. Monazite (CePO{sub 4}) can accommodate widely different elements in its crystal structure due to the irregular oxygen coordination around the metal ions. The phase can be formed at low temperatures

  3. Defense HLW Glass Degradation Model

    International Nuclear Information System (INIS)

    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

  4. 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.

  5. Immobilization of high-level wastes into sintered glass: 2

    International Nuclear Information System (INIS)

    High level radioactive wastes are immobilized into borosilicate glasses. Experiences with the variety VG 98/12 (SiO2, TiO2, Al2O3, B2O3, MgO, CaO, Na2O) are described. The pressing was performed in a matrix of 12.7 mm diameter, the walls of which were lubricated with sterotex dissolved in Cl4C. The sintering was made in an horizontal electric furnace in air atmosphere at temperatures between 500 and 600 deg C. It was observed that the maximum density occurs at 605 deg C. Comparing both the hot and the cold pressing process, it is concluded that: 1) In spite of requiring more complex equipment the hot pressing process has the advantage that lower pressures are applied, with the consequent obtainment of waste blocks with larger diameters, and 2) it is advisable that pressing process should be performed in the definitive can. (M.E.L.)

  6. 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.

  7. 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

  8. 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%.

  9. A laser-engraved glass duplicating the structure, mechanics and performance of natural nacre.

    Science.gov (United States)

    Valashani, Seyed Mohammad Mirkhalaf; Barthelat, Francois

    2015-04-01

    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%. PMID:25822595

  10. 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

  11. 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.)

  12. Semiconductor quantum optics with tailored photonic nanostructures

    International Nuclear Information System (INIS)

    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.)

  13. Insights in the Efficacy of Computer-tailored Nutrition Education

    OpenAIRE

    Kroeze, Willemieke

    2008-01-01

    textabstractSaturated fat intake is an important risk factor for cardiovascular diseases, one of the main burdens of disease worldwide. Therefore it is important to use population-wide health promotion efforts to target this risk behavior. Computer-tailored nutrition education has been found to be a very promising health education strategy that can be applied in population health promotion. However, several questions remained unanswered on why, where and for whom computer-tailored (nutrition)...

  14. Low-loss and bendable THz fiber with tailored dispersion

    DEFF Research Database (Denmark)

    Nielsen, Kristian; Rasmussen, Henrik K.; Adam, Aurèle J. L.;

    2009-01-01

    A polymer THz fiber made of Topas and having a Photonic Crystal Fiber structure is demonstrated. It has low broadband loss and the dispersion of the fiber can be tailored by adjusting the structural parameters.......A polymer THz fiber made of Topas and having a Photonic Crystal Fiber structure is demonstrated. It has low broadband loss and the dispersion of the fiber can be tailored by adjusting the structural parameters....

  15. Tailoring Dispersion properties of photonic crystal waveguides 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 analyzes, analytical sensitivity analyzes and gradient...... 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...

  16. 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.

  17. Effect of different glasses in glass bonded zeolite

    International Nuclear Information System (INIS)

    A mineral waste form has been developed for chloride waste salt generated during the pyrochemical treatment of spent nuclear fuel. The waste form consists of salt-occluded zeolite powders bound within a glass matrix. The zeolite contains the salt and immobilizes the fission products. The zeolite powders are hot pressed to form a mechanically stable, durable glass bonded zeolite. Further development of glass bonded zeolite as a waste form requires an understanding of the interaction between the glass and the zeolite. Properties of the glass that enhance binding and durability of the glass bonded zeolite need to be identified. Three types of glass, boroaluminosilicate, soda-lime silicate, and high silica glasses, have a range of properties and are now being investigated. Each glass was hot pressed by itself and with an equal amount of zeolite. MCC-1 leach tests were run on both. Soda-lime silicate and high silica glasses did not give a durable glass bonded zeolite. Boroaluminosilicate glasses rich in alkaline earths did bind the zeolite and gave a durable glass bonded zeolite. Scanning electron micrographs suggest that the boroaluminosilicate glasses wetted the zeolite powders better than the other glasses. Development of the glass bonded zeolite as a waste form for chloride waste salt is continuing

  18. New fluoroindate glass compositions

    OpenAIRE

    Messaddeq, Younes; Delben, A. A. S. T.; Boscolo, M.; Michel A. Aegerter; Soufiane, A.; Poulain, M.

    1993-01-01

    Fluoroindate glasses are potential new materials for the fabrication of IR fibers with extended spectral range. InF3SrF2BaF2ZnF2X glass compositions, where X = PbF2, CdF2, NaF and CaF2, have been prepared in a glove box using a conventional method and their phase diagrams have been determined. The addition of small quantities of GdF3 improves the stability of these compositions. Optical and thermal properties of these glasses are reported. © 1993.

  19. 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...

  20. Proceedings of the national symposium on materials and processing: functional glass/glass-ceramics, advanced ceramics and high temperature materials

    International Nuclear Information System (INIS)

    With the development of materials science it is becoming increasingly important to process some novel materials in the area of glass, advanced ceramics and high temperature metals/alloys, which play an important role in the realization of many new technologies. Such applications demand materials with tailored specifications. Glasses and glass-ceramics find exotic applications in areas like radioactive waste storage, optical communication, zero thermal expansion coefficient telescopic mirrors, human safety gadgets (radiation resistance windows, bullet proof apparels, heat resistance components etc), biomedical (implants, hyperthermia treatment, bone cement, bone grafting etc). Advanced ceramic materials have been beneficial in biomedical applications due to their strength, biocompatibility and wear resistance. Non-oxide ceramics such as carbides, borides, silicides, their composites, refractory metals and alloys are useful as structural and control rod components in high temperature fission/ fusion reactors. Over the years a number of novel processing techniques like selective laser melting, microwave heating, nano-ceramic processing etc have emerged. A detailed understanding of the various aspects of synthesis, processing and characterization of these materials provides the base for development of novel technologies for different applications. Keeping this in mind and realizing the need for taking stock of such developments a National Symposium on Materials and Processing -2012 (MAP-2012) was planned. The topics covered in the symposium are ceramics, glass/glass-ceramics and metals and materials. Papers relevant to INIS are indexed separately

  1. 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.

  2. 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.

  3. THE COLOR GLASS CONDENSATE.

    Energy Technology Data Exchange (ETDEWEB)

    MCLERRAN,L.

    2001-08-26

    The Color Glass Condensate is a state of high density gluonic matter which controls the high energy limit of hadronic interactions. Its properties are important for the initial conditions for matter produced at RHIC.

  4. Microanalysis of colloids and suspended particles from nuclear waste glass alteration

    International Nuclear Information System (INIS)

    Fully radioactive and non-radioactive Savannah River Laboratory (SRL) borosilicate glasses were reacted with water under static conditions at glass surface area to leachant volume (S/V) ratios of 340 m-1, 2000 m-1, and 20,000m-1 for times varying from several days to several years at 90C. A radioactive SRL 200 glass was also reacted under intermittent flow conditions at 90C. Colloidal and suspended glass alteration particles present in the leachates of these tests were examined with analytical transmission electron microscopy (AEM). The major colloidal phase identified in all tests was partially crystalline dioctahedral smectite clay. At 20andpuncsp; omitted000 m-1, the clay colloids flocculate and sediment, becoming attached to available surfaces when the ionic strength reached a value of about 0.3-0.5 mol·kg-1. Clay colloids remained stable in the solution for the duration of the experiment in tests conducted at S/V values of 2000 m-1 and 340 m-1. Calcite, dolomite, and transition metal oxide particles were more common in the intermittent flow tests but were also found in the static tests. Layered, Mn-bearing minerals, birnessite and asbolane, were found exclusively in the intermittent flow tests. Weeksite and a U-Ti phase were found exclusively in the static tests. Partially crystalline rare earth-bearing calcium phosphate colloids, structurally related to rhabdophane, were found in both types of tests. These particles exhibited a negative Ce anomaly. The affinity of phosphate for Pu was investigated through geochemical modeling. The results from this study and others were used to form a picture of colloidal development in the leachate from waste glass testing. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  5. Radiation stability test on multiphase glass ceramic and crystalline ceramic waste forms

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Ming, E-mail: mtang@lanl.gov [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Kossoy, Anna; Jarvinen, Gordon [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Crum, Jarrod; Turo, Laura; Riley, Brian [Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Brinkman, Kyle; Fox, Kevin; Amoroso, Jake; Marra, James [Savannah River National Laboratory, Aiken, SC 29808 (United States)

    2014-05-01

    A radiation stability study was performed on glass ceramic and crystalline ceramic waste forms. These materials are candidate host materials for immobilizing alkali/alkaline earth (Cs/Sr-CS) + lanthanide (LN) + transition metal (TM) fission product waste streams from nuclear fuel reprocessing. In this study, glass ceramics were fabricated using a borosilicate glass as a matrix in which to incorporate CS/LN/TM combined waste streams. The major phases in these multiphase materials are powellite, oxyaptite, pollucite, celsian, and durable residual glass phases. Al{sub 2}O{sub 3} and TiO{sub 2} were combined with these waste components to produce multiphase crystalline ceramics containing hollandite-type phases, perovskites, pyrochlores and other minor metal titanate phases. For the radiation stability test, selected glass ceramic and crystalline ceramic samples were exposed to different irradiation environments including low fluxes of high-energy (∼1–5 MeV) protons and alpha particles generated by an ion accelerator, high fluxes of low-energy (hundreds of keV) krypton particles generated by an ion implanter, and in-situ electron irradiations in a transmission electron microscope. These irradiation experiments were performed to simulate self-radiation effects in a waste form. Ion irradiation-induced microstructural modifications were examined using X-ray diffraction and transmission electron microscopy. Our preliminary results reveal different radiation tolerance in different crystalline phases under various radiation damage environments. However, their stability may be rate dependent which may limit the waste loading that can be achieved.

  6. 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.

  7. Low-temperature bonded glass-membrane microfluidic device for in vitro organ-on-a-chip cell culture models

    Science.gov (United States)

    Pocock, Kyall J.; Gao, Xiaofang; Wang, Chenxi; Priest, Craig; Prestidge, Clive A.; Mawatari, Kazuma; Kitamori, Takehiko; Thierry, Benjamin

    2015-12-01

    The integration of microfluidics with living biological systems has paved the way to the exciting concept of "organson- 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 utilised in the field of microfluidics but the integration of alternative functional elements within multi-layered 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 optimised 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 hours, 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.

  8. Mechanical properties of oxide-fiber reinforced glass matrix composites with BN or SnO2 interfaces

    International Nuclear Information System (INIS)

    With the aim of developing optomechanical inorganic materials, boron nitride-coated NextelTM 440 fibers and tin oxide-coated ZenTronTM glass fibers were used for manufacturing continuous and short fiber reinforced borosilicate glass matrix composites. No evident loss in tensile strength occurred for the BN-coated NextelTM fibers whereas coating the ZenTronTM fiber with tin oxide caused a significant strength decrease. Composites with ≤12 vol% of short or continuous fibers were fabricated by a standard slurry infiltration and hot-pressing process. The mechanical properties of the composites were investigated by uni- and biaxial flexural strength tests. NextelTM 440 short fiber reinforced composites with boron nitride interfaces demonstrated 'quasi'-ductile fracture behaviour under biaxial stress loading with biaxial fracture strength values of up to 88 MPa. The boron nitride layers caused fiber pull-out during fracture of long fiber reinforced composites, leading to a fracture toughness (K ic) value of 3.3 MPa m1/2. In contrast to this, the ZenTronTM glass fiber reinforced glass matrix composites with SnO2 interface exhibited brittle fracture behaviour

  9. 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

  10. 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

  11. 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.

  12. Tailoring information to enhance quitting in smokers with low motivation to quit: three basic efficacy questions.

    Science.gov (United States)

    Dijkstra, A; De Vries, H; Roijackers, J; van Breukelen, G

    1998-11-01

    Tailoring information to a target individual's features is a promising line of development in self-help interventions. In this article, 752 smokers with explicit low intention to quit were randomly assigned to 1 of 5 conditions: (a) multiple tailored letters with self-help guide, (b) multiple tailored letters only, (c) a single tailored letter with a self-help guide, (d) a single tailored letter only, or (e) a nontailored intervention. Follow-up assessment took place 4 months after the intervention. Results indicated that the single tailored intervention only had no surplus value compared with a nontailored look-alike intervention. The addition of a self-help guide to a tailored intervention was only useful in highly dependent smokers, and multiple tailoring was more effective than single tailoring. It remains important to elucidate why and for whom certain tailored interventions are more effective. PMID:9848801

  13. 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.

  14. MAGNOX:BUTEX URANIUM BEARING GLASSES PHYSICAL AND CHEMICAL ANALYSIS DATA PACKAGE

    Energy Technology Data Exchange (ETDEWEB)

    Peeler, D.; Imrich, K.; Click, D.

    2011-03-08

    Sellafield Ltd (United Kingdom) has requested technical support from the Savannah River National Laboratory (SRNL) to characterize a series of uranium-bearing, mixed alkali borosilicate glasses [WFO (2010)]. The specific glasses to be characterized are based on different blends of Magnox (WRW17 simulant) and Butex (or HASTs 1 and 2) waste types as well as different incorporation rates (or waste loadings) of each blend. Specific Magnox:Butex blend ratios of interest include: 75:25, 60:40, and 50:50. Each of these waste blend ratios will be mixed with a base glass additive composition targeting waste loadings (WLs) of 25, 28, and 32% which will result in nine different glasses. The nine glasses are to be fabricated and physically characterized to provide Sellafield Ltd with the technical data to evaluate the impacts of various Magnox:Butex blend ratios and WLs on key glass properties of interest. It should be noted that the use of 'acceptable' in the Work for Other (WFO) was linked to the results of a durability test (more specifically the Soxhlet leach test). Other processing (e.g., viscosity ({eta}), liquidus temperature (T{sub L})) or product performance (e.g., Product Consistency Test (PCT) results - in addition to the Soxhlet leach test) property constraints were not identified. For example, a critical hold point in the classification of an 'acceptable glass' prior to processing high-level waste (HLW) through the Defense Waste Processing Facility (DWPF) is an evaluation of specific processing and product performance properties against pre-defined constraints. This process is referred to as Slurry Mix Evaporator (SME) acceptability in which predicted glass properties (based on compositional measurements) are compared to predefined constraints to determine whether the glass is acceptable [Brown and Postles (1995)]. As an example, although the nominal melter temperature at DWPF is 1150 C, there is a T{sub L} constraint (without uncertainties

  15. 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.

  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. 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...

  18. The bearable lightness of all glass structures

    OpenAIRE

    Nijsse, R

    2015-01-01

    This paper is new developments in structural engineering related especially to the use of the material glass. After a philosophical discussion about why glass is the material for the Future, all glass elements and related techniques are presented from which an all glass building can be assembled. To conclude this paper ,all glass structures like a glass bridge, glass columns, a glass brick wall and a corrugated glass faced are shown in realised projects.

  19. The Future of all glass structures

    OpenAIRE

    Nijsse, R

    2015-01-01

    This paper is new developments in structural engineering related especially to the use of the material glass. After a philosophical discussion about why glass is the material for the Future, all glass elements and related techniques are presented from which an all glass building can be assembled. To conclude this paper ,all glass structures like a glass bridge, glass columns, a glass brick wall and a corrugated glass faced are shown in realised projects.

  20. Validation of Design and Analysis Techniques of Tailored Composite Structures

    Science.gov (United States)

    Jegley, Dawn C. (Technical Monitor); Wijayratne, Dulnath D.

    2004-01-01

    Aeroelasticity is the relationship between the elasticity of an aircraft structure and its aerodynamics. This relationship can cause instabilities such as flutter in a wing. Engineers have long studied aeroelasticity to ensure such instabilities do not become a problem within normal operating conditions. In recent decades structural tailoring has been used to take advantage of aeroelasticity. It is possible to tailor an aircraft structure to respond favorably to multiple different flight regimes such as takeoff, landing, cruise, 2-g pull up, etc. Structures can be designed so that these responses provide an aerodynamic advantage. This research investigates the ability to design and analyze tailored structures made from filamentary composites. Specifically the accuracy of tailored composite analysis must be verified if this design technique is to become feasible. To pursue this idea, a validation experiment has been performed on a small-scale filamentary composite wing box. The box is tailored such that its cover panels induce a global bend-twist coupling under an applied load. Two types of analysis were chosen for the experiment. The first is a closed form analysis based on a theoretical model of a single cell tailored box beam and the second is a finite element analysis. The predicted results are compared with the measured data to validate the analyses. The comparison of results show that the finite element analysis is capable of predicting displacements and strains to within 10% on the small-scale structure. The closed form code is consistently able to predict the wing box bending to 25% of the measured value. This error is expected due to simplifying assumptions in the closed form analysis. Differences between the closed form code representation and the wing box specimen caused large errors in the twist prediction. The closed form analysis prediction of twist has not been validated from this test.