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Sample records for adding glass microfilament

  1. 6. Vick Farm, interior perspective of stained glass window, added ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. Vick Farm, interior perspective of stained glass window, added as part of deck addition on west side. - Vick Farm, North side Idlewild Road, 0.2 mile northwest of Idlewild & Maplewood Drive, Burlington, Boone County, KY

  2. Method and apparatus for testing microfilaments

    DOEpatents

    Schleitweiler, P.M.; Merten, C.W. Jr.

    1995-08-01

    A method and apparatus are disclosed for testing tensile strength of microfilaments. Fibers as small as 0.001 inch in diameter and 0.04 inches in length have been tested, although the method and apparatus of the invention are capable of testing fibers of smaller diameter and length. The invention utilizes a method wherein one or both ends of a microfilament is gripped using resin which is softened sufficiently to accept an end of the microfilament and then allowed to harden. The invention also employs the use of a translation stage capable of controlled three-dimensional movement suited to facilitating gripping of the microfilament. 2 figs.

  3. Method and apparatus for testing microfilaments

    DOEpatents

    Schleitweiler, Patrick M.; Merten, Jr., Charles W.

    1995-08-01

    A method and apparatus are disclosed for testing tensile strength of microfilaments. Fibers as small as 0.001 inch in diameter and 0.04 inches in length have been tested, although the method and apparatus of the invention are capable of testing fibers of smaller diameter and length. The invention utilizes a method wherein one or both ends of a microfilament is gripped using resin which is softened sufficiently to accept an end of the microfilament and then allowed to harden. The invention also employs the use of a translation stage capable of controlled three-dimensional movement suited to facilitating gripping of the microfilament.

  4. Toughness, bonding and fluoride-release properties of hydroxyapatite-added glass ionomer cement.

    PubMed

    Lucas, Milanita E; Arita, Kenji; Nishino, Mizuho

    2003-09-01

    Improving the mechanical strength of glass ionomer cement while preserving its favorable clinical properties such as fluoride release, bonding to tooth structure and biocompatibility is desirable. In this study, hydroxyapatite was incorporated into chemically setting glass ionomer cement and its effect on the fracture toughness, bonding to dentin and fluoride release was identified. Commercial glass ionomer cement (Fuji IX GP((R)) ) was the control and base material. Eight weight percent of hydroxyapatite was added into the glass ionomer powder. Specimens were fabricated and the fracture toughness, shear bond strength and eluted fluoride ion concentration were measured. Adding hydroxyapatite into the glass ionomer cement led to significantly higher fracture toughness after 15min and 24h from mixing. The hydroxyapatite-added cement also exhibited bond strength to dentin similar to that of the control from 15min to 56 days and consistent fluoride release for 13 weeks. SEM findings showed a cohesive type of fracture in the material for all specimens in both groups. These results indicate that hydroxyapatite-added glass ionomer cement has a potential as a reliable restorative material with improved fracture toughness, long-term bonding to dentin and unimpeded ability of sustained fluoride release.

  5. Dynamic aspects of microfilament-membrane attachments.

    PubMed

    Jockusch, B M; Wiegand, C; Temm-Grove, C J; Nikolai, G

    1993-01-01

    Microfilament-membrane attachment sites are complex structures that are essential for tissue differentiation in animals. In this article, we focus on the assembly and dynamics of such contact sites as seen in two cell types differentiating in cultures of the embryonic chicken heart, cardiocytes and fibroblasts. Concentrating on the cytoplasmic domain, we refer to previous biochemical, light, and electron microscopic studies on the structure and dynamics of these regions and supplement them with our own recent data. Although many details are still to be elucidated, we would like to propose the following model. Actin, alpha-actinin and vinculin are the major structural components of all microfilament-membrane contacts. Various subtypes of junctions are characterised by additional structural components or by specific isoforms. Temporal regulation of contact sites is linked to assembly and disassembly of microfilaments and might be controlled by special regulatory proteins. Finally, the cytoplasmic domains of junctional complexes may serve as structural matrices for the positioning of proteins involved in signal transduction pathways.

  6. Nomofungin: a new microfilament disrupting agent.

    PubMed

    Ratnayake, A S; Yoshida, W Y; Mooberry, S L; Hemscheidt, T K

    2001-12-28

    A new alkaloid, nomofungin, has been isolated from the fermentation broth of an unidentified endophytic fungus obtained from the bark of Ficus microcarpa L. The structure of nomofungin was determined by application of spectroscopic methods. The absolute stereochemistry of nomofungin was assigned by using the exciton chirality method. Nomofungin disrupts microfilaments in cultured mammalian cells and is moderately cytotoxic with minimum inhibitory concentrations (MICs) of 2 and 4.5 microg/mL against LoVo and KB cells, respectively. The ring system of nomofungin is unprecedented.

  7. Microfilament distribution in protonemata of the moss Ceratodon

    NASA Technical Reports Server (NTRS)

    Walker, L. M.; Sack, F. D.

    1995-01-01

    Microfilaments were visualized in dark-grown protonemata of the moss Ceratodon to assess their possible role in tip growth and gravitropism. The relative effectiveness of rhodamine phalloidin (with or without m-maleimidobenzoyl-N-hydroxysuccinimide ester (MBS)) and of immunofluorescence (using the C4 antibody) was evaluated for actin localization in the same cell type. Using immunofluorescence, microfilaments were primarily in an axial orientation within the apical cell. However, a more complex network of microfilaments was observed using rhodamine phalloidin after MBS pretreatment, especially when viewed by confocal laser scanning microscopy. This method revealed a rich three dimensional network of fine microfilaments throughout the apical cell, including the extreme apex. Although there were numerous internal microfilaments, peripheral microfilaments were more abundant. No major redistribution of microfilaments was detected after gravistimulation. The combination of MBS, rhodamine phalloidin, and confocal laser scanning microscopy preserves and reveals microfilaments remarkably well and documents perhaps the most extensive F-actin network visualized to date in any tip-growing cell.

  8. Recycling of boiler and incinerator ash into value added glass products

    SciTech Connect

    Hnat, J.G.; Bartone, L.M.

    1996-09-01

    This paper discusses the recycling of coal-fired boiler and incinerator ashes into value added glass products via the use of a newly developed, fossil-fuel fired, high temperature melting process. The Vortec patented Cyclone Melting System (CMS{trademark}) has a number of significant advantages for recycling solid wastes including: the oxidation of organic and metal contaminants, formation of non-leachable glasses which can be sold as value added products, high melting efficiencies, multi-fuel capability, low operating and maintenance costs and low NO{sub x} emissions. This paper summarizes some of the challenges facing process industries and utilities in the recycling and reuse of industrial solid wastes. The results of laboratory and pilot scale testing with several pulverized coal-fired boiler ashes, several municipal solid waste incinerator ashes, and a sewage sludge incinerator ash are summarized. Information on ash properties, melting characteristics, system performance, toxicity characteristics leaching procedure (TCLP) testing results, flue gas emissions, recycled products, and economics are presented. The application of the CMS to the production of several value added glass and ceramic products is also discussed.

  9. Process for Converting Waste Glass Fiber into Value Added Products, Final Report

    SciTech Connect

    Hemmings, Raymond T.

    2005-12-31

    Nature of the Event: Technology demonstration. The project successfully met all of its technical objectives. Albacem has signed an exclusive licensing agreement with Vitro Minerals Inc., a specialty minerals company, to commercialize the Albacem technology (website: www.vitrominerals.com). Location: The basic research for the project was conducted in Peoria, Illinois, and Atlanta, Georgia, with third-party laboratory verification carried out in Ontario, Canada. Pilot-scale trials (multi-ton) were conducted at a facility in South Carolina. Full-scale manufacturing facilities have been designed and are scheduled for construction by Vitro Minerals during 2006 at a location in the Georgia, North Carolina, and South Carolina tri-state area. The Technology: This technology consists of a process to eliminate solid wastes generated at glass fiber manufacturing facilities by converting them to value-added materials (VCAS Pozzolans) suitable for use in cement and concrete applications. This technology will help divert up to 250,000 tpy of discarded glass fiber manufacturing wastes into beneficial use applications in the concrete construction industry. This technology can also be used for processing glass fiber waste materials reclaimed from monofills at manufacturing facilities. The addition of take-back materials and reclamation from landfills can help supply over 500,000 tpy of glass fiber waste for processing into value added products. In the Albacem process, waste glass fiber is ground to a fine powder that effectively functions as a reactive pozzolanic admixture for use in portland ce¬ment-based building materials and products, such as concrete, mortars, terrazzo, tile, and grouts. Because the waste fiber from the glass manufacturing industry is vitreous, clean, and low in iron and alkalis, the resulting pozzolan is white in color and highly consistent in chemical composition. This white pozzolan, termed VCAS Pozzolan (for Vitreous Calcium-Alumino-Silicate). is

  10. Helical Microfilaments with Alternating Imprinted Intrinsic Curvatures.

    PubMed

    Silva, Pedro Emanuel Santos; Godinho, Maria Helena

    2017-03-01

    There has been an intense research for developing techniques that can produce filaments with helical shapes, given the widespread of potential applications. In this work, how helices with different curvatures can be precisely imprinted in microfilaments is shown. It is also shown that using this technique, it is possible to produce, in a single fiber, helices with different curvatures. This striking and innovative behavior is observed when one side of the stretched filaments is irradiated with UV light, modifying the mechanical properties at surface. Upon release, the regions with higher curvature start to curl first, while regions with lower intrinsic curvature remain stretched until start to curl later. The results presented here can be important to understand why structures adopt a helical shape in general, which can be of interest in nanotechnology, biomolecular science, or even to understand why plant filaments curl.

  11. A Microfilament-eruption Mechanism for Solar Spicules

    NASA Astrophysics Data System (ADS)

    Sterling, Alphonse C.; Moore, Ronald L.

    2016-09-01

    Recent investigations indicate that solar coronal jets result from eruptions of small-scale chromospheric filaments, called minifilaments; that is, the jets are produced by scaled-down versions of typical-sized filament eruptions. We consider whether solar spicules might in turn be scaled-down versions of coronal jets, being driven by eruptions of microfilaments. Assuming a microfilament's size is about a spicule's width (∼300 km), the estimated occurrence number plotted against the estimated size of erupting filaments, minifilaments, and microfilaments approximately follows a power-law distribution (based on counts of coronal mass ejections, coronal jets, and spicules), suggesting that many or most spicules could result from microfilament eruptions. Observed spicule-base Ca ii brightenings plausibly result from such microfilament eruptions. By analogy with coronal jets, microfilament eruptions might produce spicules with many of their observed characteristics, including smooth rise profiles, twisting motions, and EUV counterparts. The postulated microfilament eruptions are presumably eruptions of twisted-core micro-magnetic bipoles that are ∼1.″0 wide. These explosive bipoles might be built and destabilized by merging and cancelation of approximately a few to 100 G magnetic-flux elements of size ≲ 0\\buildrel{\\prime\\prime}\\over{.} 5{--}1\\buildrel{\\prime\\prime}\\over{.} 0. If, however, spicules are relatively more numerous than indicated by our extrapolated distribution, then only a fraction of spicules might result from this proposed mechanism.

  12. Statoliths pull on microfilaments: experiments under microgravity.

    PubMed

    Buchen, B; Braun, M; Hejnowicz, Z; Sievers, A

    1993-01-01

    Previous videomicroscopy of Chara rhizoids during parabolic flights of rockets showed that the weightless statoliths moved basipetally. A hypothesis was offered that the removal of gravity force disturbed the initial balance between this force and the basipetally acting forces generated in a dynamic interaction of statoliths with microfilaments (MFs). The prediction of this hypothesis that the statoliths would not be displaced basipetally during the microgravity phase (MG-phase) after disorganizing the MFs was tested by videomicroscopy of a rhizoid treated with cytochalasin D (CD) immediately before the flight. The prediction was fully supported by the flight experiment. Additionally, by chemical fixation of many rhizoids at the end of the MG-phase it was shown that all rhizoids treated with CD before the flight had statoliths at the same location. i.e., sedimented an the apical cell wall, while all untreated rhizoids had statoliths considerably displaced basipetally from their normal position. Thus, a dynamical interaction involving shearing forces between MFs and statoliths appears highly probable.

  13. Microfilament Distribution in Maize Meiotic Mutants Correlates with Microtubule Organization.

    PubMed Central

    Staiger, CJ; Cande, WZ

    1991-01-01

    Microtubules and microfilaments often codistribute in plants; their presumed interaction can be tested with drugs although it is not always clear that these are without side effects. In this study, we exploited mutants defective in meiotic cell division to investigate in a noninvasive way the relationship between the two cytoskeletal elements. By staining unfixed, permeabilized cells with rhodamine-phalloidin, spatial and temporal changes in microfilament distribution during maize meiosis were examined. In wild-type microsporocytes, a microtubule array that radiates from the nucleus disappeared during spindle formation and returned at late telophase. This result differed from the complex cytoplasmic microfilament array that is present at all stages, including karyokinesis and cytokinesis. During division, a second class of microfilaments also was observed in the spindle and phragmoplast. To analyze this apparent association of microtubules and microfilaments, we examined several meiotic mutants known to have stage-specific disruptions in their microtubule arrays. Two mutations that altered the number or form of meiotic spindles also led to a dramatic reorganization of F-actin. In contrast, rearrangement of nonspindle, cytoplasmic microtubules did not lead to concomitant changes in F-actin distribution. These results suggested that microtubules and microfilaments interact in a cell cycle-specific and site-specific fashion during higher plant meiosis. PMID:12324607

  14. Depolymerization of macrophage microfilaments prevents induction and inhibits activity of nitric oxide synthase.

    PubMed

    Fernandes, P D; Araujo, H M; Riveros-Moreno, V; Assreuy, J

    1996-12-01

    We have investigated the relationship between peritoneal murine macrophage cytoskeleton and nitric oxide (NO) synthase (NOS). Activation of the cells with lipopolysaccharide plus interferon-gamma (LI) induced iNOS, detected by nitrite or by labeled L-citrulline production and by a specific antibody against macrophage iNOS. Addition of cytochalasin B (a microfilament-depolymerizing agent) caused a dose-dependent inhibition in NO production by macrophages, whereas colchicine (a microtubule depolymerizing agent) inhibited it only by 20% and not dose-dependently. Addition of cytochalasin B together with LI abolished nitrite and L-citrulline accumulation as well as the amount of iNOS antigen in activated macrophage. Moreover, addition of cytochalasin B 6 or 12 h after stimulus, also decreased the nitrite and L-citrulline production by macrophages although iNOS antigen content by Western blot was the same in the presence or in the absence of cytochalasin B added 12 h after activation. Since cytochalasin B failed to inhibit iNOS activity directly, its inhibitory effects on NO production by macrophages is likely to be indirect, through microfilament network in central regions of cells, but not in filaments seen at pseudopodia or edging processes. Our findings demonstrate that disruption of microfilaments but not of microtubules prevents the iNOS induction process and inhibits its enzymatic activity in activated macrophages.

  15. Charge Carrier Relaxation Study in Glass-Added Barium Titanate Ceramics Using Thermally Stimulated Depolarization Current

    NASA Astrophysics Data System (ADS)

    Zhang, Qian; Zhang, Yong; Liu, Xiaolin; Song, Xiaozhen; Zhu, Jia; Baturin, Ivan

    2016-08-01

    The depolarization process of glass-added barium titanate (BaTiO3) ceramics with two different glass concentrations was investigated using a thermally stimulated depolarization current (TSDC) technique. The TSDC spectra of the glass-added BaTiO3 ceramics show three peaks. The first sharp peak near the Curie temperature is due to pyroelectric current associated with ferroelectric-paraelectric phase transition. The middle temperature peak at about 200°C showed no dependence on the depolarization current peak position in the polarization field, and the activation energies of this peak were between 0.43 eV and 0.55 eV, which are attributed to the behavior of defect dipoles related to oxygen vacancies within the BaTiO3 grains. Moreover, the high temperature peak at around 300°C indicated that the depolarization current peak position depends on the polarization temperature and decreases with increasing polarization field. The activation energy of this high temperature peak was between 0.78 eV and 0.98 eV, which is similar to the activation energy for the motion of oxygen vacancies in perovskite oxides. The high temperature peak could be attributed to the migration of oxygen vacancies across grain boundaries. In this work we developed a model in which oxygen vacancies that originated from the defect within grains migrated from the anode to the cathode and some were trapped at the grain boundaries. It is presented here and successfully interprets the appearance and behavior of these peaks.

  16. Effects of adding silica particles on certain properties of resin-modified glass-ionomer cement

    PubMed Central

    Felemban, Nayef H.; Ebrahim, Mohamed I.

    2016-01-01

    Objective: This study was conducted to evaluate the effect of incorporation of silica particles with different concentrations on some properties of resin-modified glass ionomer cement (RMGIC): Microleakage, compressive strength, tensile strength, water sorption, and solubility. Materials and Methods: Silica particle was incorporated into RMGIC powder to study its effects, one type of RMGIC (Type II visible light-cured) and three concentrations of silica particles (0.06, 0.08, and 0.1% weight) were used. One hundred and twenty specimens were fabricated for measuring microleakage, compressive strength, tensile strength, water sorption, and solubility. Statistical Analysis: One-way analysis of variance and Tukey's tests were used for measuring significance between means where P ≤ 0.05. Results: RMGIC specimens without any additives showed significantly highest microleakage and lowest compressive and tensile strengths. Conclusion: Silica particles added to RMGIC have the potential as a reliable restorative material with increased compressive strength, tensile strength, and water sorption but decreased microleakage and water solubility. PMID:27095901

  17. Remedial processing of oil shale fly ash (OSFA) and its value-added conversion into glass-ceramics.

    PubMed

    Zhang, Zhikun; Zhang, Lei; Li, Aimin

    2015-12-01

    Recently, various solid wastes such as sewage sludge, coal fly ash and slag have been recycled into various products such as sintered bricks, ceramics and cement concrete. Application of these recycling approaches is much better and greener than conventional landfills since it can solve the problems of storage of industrial wastes and reduce exploration of natural resources for construction materials to protect the environment. Therefore, in this study, an attempt was made to recycle oil shale fly ash (OSFA), a by-product obtained from the extracting of shale oil in the oil shale industry, into a value-added glass-ceramic material via melting and sintering method. The influence of basicity (CaO/SiO2 ratio) by adding calcium oxide on the performance of glass-ceramics was studied in terms of phase transformation, mechanical properties, chemical resistances and heavy metals leaching tests. Crystallization kinetics results showed that the increase of basicity reduced the activation energies of crystallization but did not change the crystallization mechanism. When increasing the basicity from 0.2 to 0.5, the densification of sintering body was enhanced due to the promotion of viscous flow of glass powders, and therefore the compression strength and bending strength of glass-ceramics were increased. Heavy metals leaching results indicated that the produced OSFA-based glass-ceramics could be taken as non-hazardous materials. The maximum mechanical properties of compression strength of 186 ± 3 MPa, bending strength of 78 ± 6 MPa, good chemical resistances and low heavy metals leaching concentrations showed that it could be used as a substitute material for construction applications. The proposed approach will be one of the potential sustainable solutions in reducing the storage of oil shale fly ash as well as converting it into a value-added product.

  18. Preparation of low water-sorption lightweight aggregates from harbor sediment added with waste glass.

    PubMed

    Wei, Yu-Ling; Lin, Chang-Yuan; Ko, Kuan-Wei; Wang, H Paul

    2011-01-01

    A harbor sediment is successfully recycled at 1150 °C as low water-absorption lightweight aggregate via addition of waste glass powder. Sodium content in the waste glass is responsible for the formation of low-viscosity viscous phases during firing process to encapsulate the gases generated for bloating pellet samples. Water sorption capacity of the lightweight products can be considerably reduced from 5.6% to 1.5% with the addition of waste glass powder. Low water-absorption property of lightweight products is beneficial for preparing lightweight concrete because the water required for curing the cement would not be seized by lightweight aggregate filler, thus preventing the failure of long-term concrete strength.

  19. Calcium influx through stretch-activated channels mediates microfilament reorganization in osteoblasts under simulated weightlessness

    NASA Astrophysics Data System (ADS)

    Luo, Mingzhi; Yang, Zhouqi; Li, Jingbao; Xu, Huiyun; Li, Shengsheng; Zhang, Wei; Qian, Airong; Shang, Peng

    2013-06-01

    We have explored the role of Ca2+ signaling in microfilament reorganization of osteoblasts induced by simulated weightlessness using a random positioning machine (RPM). The RPM-induced alterations of cell morphology, microfilament distribution, cell proliferation, cell migration, cytosol free calcium concentration ([Ca2+]i), and protein expression in MG63 osteoblasts were investigated. Simulated weightlessness reduced cell size, disrupted microfilament, inhibited cellular proliferation and migration, and induced an increase in [Ca2+]i in MG63 human osteosarcoma cells. Gadolinium chloride (Gd), an inhibitor for stretch-activated channels, attenuated the increase in [Ca2+]i and microfilament disruption. Further, the expression of calmodulin was significantly increased by simulated weightlessness, and an inhibitor of calmodulin, W-7, aggravated microfilament disruption. Our findings demonstrate that simulated weightlessness induces Ca2+ influx through stretch-activated channels, then results in microfilament disruption.

  20. Effect of adding nanometre-sized heterogeneities on the structural dynamics and the excess wing of a molecular glass former

    NASA Astrophysics Data System (ADS)

    Gupta, S.; Fischer, J. K. H.; Lunkenheimer, P.; Loidl, A.; Novak, E.; Jalarvo, N.; Ohl, M.

    2016-10-01

    We present the relaxation dynamics of glass-forming glycerol mixed with 1.1 nm sized polyhedral oligomeric silsesquioxane (POSS) molecules using dielectric spectroscopy (DS) and two different neutron scattering (NS) techniques. Both, the reorientational dynamics as measured by DS and the density fluctuations detected by NS reveal a broadening of the α relaxation when POSS molecules are added. Moreover, we find a significant slowing down of the α-relaxation time. These effects are in accord with the heterogeneity scenario considered for the dynamics of glasses and supercooled liquids. The addition of POSS also affects the excess wing in glycerol arising from a secondary relaxation process, which seems to exhibit a dramatic increase in relative strength compared to the α relaxation.

  1. Effect of adding nanometre-sized heterogeneities on the structural dynamics and the excess wing of a molecular glass former

    PubMed Central

    Gupta, S.; Fischer, J. K. H.; Lunkenheimer, P.; Loidl, A.; Novak, E.; Jalarvo, N.; Ohl, M.

    2016-01-01

    We present the relaxation dynamics of glass-forming glycerol mixed with 1.1 nm sized polyhedral oligomeric silsesquioxane (POSS) molecules using dielectric spectroscopy (DS) and two different neutron scattering (NS) techniques. Both, the reorientational dynamics as measured by DS and the density fluctuations detected by NS reveal a broadening of the α relaxation when POSS molecules are added. Moreover, we find a significant slowing down of the α-relaxation time. These effects are in accord with the heterogeneity scenario considered for the dynamics of glasses and supercooled liquids. The addition of POSS also affects the excess wing in glycerol arising from a secondary relaxation process, which seems to exhibit a dramatic increase in relative strength compared to the α relaxation. PMID:27725747

  2. Selective, pulsed CVD of platinum on microfilament gas sensors

    SciTech Connect

    Manginell, R.P.; Smith, J.H.; Ricco, A.J.; Moreno, D.J.; Hughes, R.C.; Huber, R.J.; Senturia, S.D.

    1996-05-01

    A post-processing, selective micro-chemical vapor deposition (``micro-CVD``) technology for the deposition of catalytic films on surface-micromachined, nitride-passivated polysilicon filaments has been investigated. Atmospheric pressure deposition of Pt on microfilaments was accomplished by thermal decomposition of Pt acetylacetonate; deposition occurs selectively only on those filaments which are electrically heated. Catalyst morphology, characterized by SEM, can be controlled by altering deposition time, filament temperature, and through the use of pulsed heating of the filament during deposition. Morphology plays an important role in determining the sensitivity of these devices when used as combustible gas sensors.

  3. Light diffusion through composite restorations added with spherical glass mega fillers

    PubMed Central

    BASSI, M. ANDREASI; BASSI, S. ANDREASI; ANDRISANI, C.; LICO, S.; BAGGI, L.; LAURITANO, D.

    2016-01-01

    SUMMARY Purpose Evaluate how the spherical glass mega fillers (SGMFs) can positively interfere with light diffusion when incorporated in a composite restoration. Materials and methods 30 samples (Ss) were performed, applying 2 composite layers of 3 mm each: 6 were made with composite only; 6 with a layer of SGMFs of O1.5mm within the first layer of composite; 6 with 2 overlapping layers of SGMFs of O1.5mm; 6 with a layer of SGMFs of O2mm; 6 with 2 overlapping layers of SGMFs of O2mm. The curing time was set at 40s for the first layer, and 120s for the second layer, transilluminated through the first layer. Digital pictures were taken, in standardized settings, during the transillumination, and the light intensity was measured with a digital image analysis software. Results From a lateral view the Ss with a single layer of SGMFs of O1.5mm and O2mm, the relative increments of light intensity, were of 24.37% and 33.33% respectively. Concerning the Ss made with 2 layers of SGMFs, the relative increments were of 67.99% and 66.4% respectively. In front view has emerged a relative increase rate of light intensity of 53.66% and 79.58%, in the Ss with a single layer of SGMFs of O1.5mm and of O2mm respectively. Furthermore, in the Ss with two layers of SGMFs of O1.5mm and O2mm the relative increments were of 267.53 and 319.63% respectively. Conclusion The SGMFs are reliable in facilitating light diffusion within the light-curing composite resins. PMID:28280536

  4. Microfilament Depolymerization Is a Pre-requisite for Stem Cell Formation During In vitro Shoot Regeneration in Arabidopsis

    PubMed Central

    Tang, Li Ping; Li, Xiao Ming; Dong, Yu Xiu; Zhang, Xian Sheng; Su, Ying Hua

    2017-01-01

    De novo shoot regeneration is widely used in fundamental studies and agricultural applications. Actin microfilaments are involved in many aspects of plant cell division, cell morphogenesis and cell signal transduction. However, the function of actin microfilaments during de novo shoot regeneration is poorly understood. Here, we investigated the organization of actin microfilaments during this process and found that stem cell formation was associated with microfilament depolymerization. Furthermore, inhibition of microfilament depolymerization by phalloidin treatment or downregulation of actin depolymerizing factors (ADFs) restrained stem cell initiation and shoot regeneration. Inhibition of ADF expression affected the architecture of microfilaments during stem cell formation, and the polar transport and distribution of auxin were also disrupted. Together, our results demonstrate that organization of the microfilament cytoskeleton play important roles in stem cell formation and shoot meristem induction during shoot regeneration. PMID:28261231

  5. The nitrate reductase inhibitor, tungsten, disrupts actin microfilaments in Zea mays L.

    PubMed

    Adamakis, Ioannis-Dimosthenis S; Panteris, Emmanuel; Eleftheriou, Eleftherios P

    2014-05-01

    Tungsten is a widely used inhibitor of nitrate reductase, applied to diminish the nitric oxide levels in plants. It was recently shown that tungsten also has heavy metal attributes. Since information about the toxic effects of tungsten on actin is limited, and considering that actin microfilaments are involved in the entry of tungsten inside plant cells, the effects of tungsten on them were studied in Zea mays seedlings. Treatments with sodium tungstate for 3, 6, 12 or 24 h were performed on intact seedlings and seedlings with truncated roots. Afterwards, actin microfilaments in meristematic root and leaf tissues were stained with fluorescent phalloidin, and the specimens were examined by confocal laser scanning microscopy. While the actin microfilament network was well organized in untreated seedlings, in tungstate-treated ones it was disrupted in a time-dependent manner. In protodermal root cells, the effects of tungsten were stronger as cortical microfilaments were almost completely depolymerized and the intracellular ones appeared highly bundled. Fluorescence intensity measurements confirmed the above results. In the meristematic leaf tissue of intact seedlings, no depolymerization of actin microfilaments was noticed. However, when root tips were severed prior to tungstate application, both cortical and endoplasmic actin networks of leaf cells were disrupted and bundled after 24 h of treatment. The differential response of root and leaf tissues to tungsten toxicity may be due to differential penetration and absorption, while the effects on actin microfilaments could not be attributed to the nitric oxide depletion by tungsten.

  6. Effect of Adding Plasticizer on Ionic Conductivity and Glass Transition Temperature of PMMA+Lithium Iodide Complexes

    NASA Astrophysics Data System (ADS)

    Zulkepely, N. R.; Majid, S. R.; Osman, Z.

    2010-07-01

    Polymer electrolyte films based on poly-methylmethacrylate (PMMA) have been prepared using the solution casting technique. Ethylene carbonate (EC) was used as a plasticizer and lithium iodide (LiI) as a doping salt. The ionic conductivity of the films was analyzed using ac impedance spectroscopy. It can be observed that the ionic conductivity of PMMA+LiI film increased when the plasticizer was added. The conductivity-temperature dependence studies were carried out in the temperature range between 303 and 393 K. The results indicate that the conductivity is increased when the temperature is increased. The glass transition temperature, Tg of the polymer electrolyte films was measured using Differential Scanning Calorimetry (DSC). The Tg of the pure PMMA film is ˜125 °C. On addition of plasticizer, it can be observed that the Tg of PMMA+LiI film is decreased. This reveals that the plasticizer, EC has reduced the Tg of the polymer electrolyte film by increasing segmental motion of the polymer resulting in conductivity enhancement.

  7. Statolith positioning by microfilaments in Chara rhizoids and protonemata

    NASA Astrophysics Data System (ADS)

    Hodick, Dieter; Buchen, Brigitte; Sievers, Andreas

    The rhizoids of the green alga Chara are tip-growing cells with a precise positive gravitropism. In rhizoids growing downwards the statoliths never sediment upon the cell wall at the very tip but keep a minimal distance of approximately 10 μm from the cell vertex. It has been argued that this position is attained by a force acting upon the statoliths in the basal direction and that this force is generated by an interaction between actin microfilaments and myosin on the statolith membrane. This hypothesis received experimental support from (1) effects of the actin-attacking drug cytochalasin, (2) experiments under microgravity conditions, and (3) clinostat experiments. Using video-microscopy it is now shown that this basipetal force also acts on statoliths during sedimentation. As a result, many statoliths in Chara rhizoids do not simply fall along the plumb line while sedimenting during gravistimulation, but move basipetally. This statolith movement is compared to the ones occurring in the unicellular Chara protonemata during gravistimulation. Dark-grown protonemata morphologically closely resemble the rhizoids but respond negatively gravitropic. In contrast to the rhizoids a gravistimulation of the protonemata induces a transport of statoliths towards the tip. This transport is mainly along the cell axis and not parallel to the gravity vector. It is stressed that the sedimentation of statoliths in Chara rhizoids and protonemata as well as in gravity sensing cells in mosses and higher plants is accompanied by statolith movements based on interactions with the cytoskeleton. In tip-growing cells these movements direct the statoliths to a definite region of the cell where they can sediment and elicit a gravitropic curvature. In the statocytes of higher plants the interactions of the statoliths with the cytoskeleton probably do not serve primarily to move the statoliths but to transduce mechanical stresses from the sedimenting statoliths to the plasma membrane.

  8. In Vitro Bioactivity and Antimicrobial Tuning of Bioactive Glass Nanoparticles Added with Neem (Azadirachta indica) Leaf Powder

    PubMed Central

    Prabhu, M.; Ruby Priscilla, S.; Kavitha, K.; Manivasakan, P.; Rajendran, V.; Kulandaivelu, P.

    2014-01-01

    Silica and phosphate based bioactive glass nanoparticles (58SiO2-33CaO-9P2O5) with doping of neem (Azadirachta indica) leaf powder and silver nanoparticles were prepared and characterised. Bioactive glass nanoparticles were produced using sol-gel technique. In vitro bioactivity of the prepared samples was investigated using simulated body fluid. X-ray diffraction (XRD) pattern of prepared glass particles reveals amorphous phase and spherical morphology with a particle size of less than 50 nm. When compared to neem doped glass, better bioactivity was attained in silver doped glass through formation of hydroxyapatite layer on the surface, which was confirmed through XRD, Fourier transform infrared (FTIR), and scanning electron microscopy (SEM) analysis. However, neem leaf powder doped bioactive glass nanoparticles show good antimicrobial activity against Staphylococcus aureus and Escherichia coli and less bioactivity compared with silver doped glass particles. In addition, the biocompatibility of the prepared nanocomposites reveals better results for neem doped and silver doped glasses at lower concentration. Therefore, neem doped bioactive glass may act as a potent antimicrobial agent for preventing microbial infection in tissue engineering applications. PMID:25276834

  9. In vitro bioactivity and antimicrobial tuning of bioactive glass nanoparticles added with neem (Azadirachta indica) leaf powder.

    PubMed

    Prabhu, M; Ruby Priscilla, S; Kavitha, K; Manivasakan, P; Rajendran, V; Kulandaivelu, P

    2014-01-01

    Silica and phosphate based bioactive glass nanoparticles (58SiO2-33CaO-9P2O5) with doping of neem (Azadirachta indica) leaf powder and silver nanoparticles were prepared and characterised. Bioactive glass nanoparticles were produced using sol-gel technique. In vitro bioactivity of the prepared samples was investigated using simulated body fluid. X-ray diffraction (XRD) pattern of prepared glass particles reveals amorphous phase and spherical morphology with a particle size of less than 50 nm. When compared to neem doped glass, better bioactivity was attained in silver doped glass through formation of hydroxyapatite layer on the surface, which was confirmed through XRD, Fourier transform infrared (FTIR), and scanning electron microscopy (SEM) analysis. However, neem leaf powder doped bioactive glass nanoparticles show good antimicrobial activity against Staphylococcus aureus and Escherichia coli and less bioactivity compared with silver doped glass particles. In addition, the biocompatibility of the prepared nanocomposites reveals better results for neem doped and silver doped glasses at lower concentration. Therefore, neem doped bioactive glass may act as a potent antimicrobial agent for preventing microbial infection in tissue engineering applications.

  10. From pumice to obsidian: eruptive behaviors that produce tephra-flow dyads. I- The AD1100 Big Glass Mountain eruption at Medicine Lake Volcano (California).

    NASA Astrophysics Data System (ADS)

    Giachetti, T.; Shea, T.; Gonnermann, H. M.; Donnelly-Nolan, J. M.; Ramsey, D. W.

    2014-12-01

    Associations of tephra and lava flow/domes produced by eruptions involving evolved magmas are a common occurrence in various types of volcanic settings (e.g. Pu'u Wa'awa'a ~114ka, Hawaii; South Mono ~AD625, California; Newberry Big Obsidian flow ~AD700, Oregon; Big Glass Mountain ~AD1100, California; Inyo ~AD1350, California, Chaitén AD2008-2009, Chile; Cordón Caulle AD2011-2012, Chile), ejecting up to a few cubic km of material (tephra+flow/dome). Most, if not all, of these eruptions have in common the paradoxical coexistence of (1) eruptive styles which are inferred to be sustained in nature (subplinian and plinian), with (2) a pulsatory behavior displayed by the resulting fall deposits, and (3) the coeval ejection of vesicular tephra and pyroclastic obsidian. Through two case studies, we explore this apparent set of paradoxes, and their significance in understanding transitions from explosive to effusive behavior. In this first case study (also cf. Leonhardi et al., same session), we present a new detailed stratigraphy of the AD1100 Big Glass Mountain eruption (Medicine Lake Volcano), along with a series of density measurements of tephra collected from several key units identified in the proximal fall deposits. The geochemical character of pumice and obsidian clasts from both the tephra and the obsidian flow is used to trace the origins of the different lithologies involved. We find that tens of waxing and waning cycles occurred during this eruption with at least two protracted phases, and that perhaps the term (sub)plinian may not be completely adequate to describe this particular eruption style. We also review models for the formation of juvenile pyroclastic obsidian in the context of rhyolitic eruptions.

  11. Immunohistochemical evidence for an association of ribosomes with microfilaments in 3T3 fibroblasts.

    PubMed

    Hesketh, J E; Horne, Z; Campbell, G P

    1991-02-01

    Ribosome distribution in cultured fibroblasts was investigated immunohistochemically using antibodies which recognize the 60S ribosomal subunit. After treatment of cells with buffer containing 25mM KCl and 0.05% Nonidet-P40 immunostained material was present in punctate patterns and linear arrays consistent with some ribosomes being associated with the cytoskeleton. Treatment of the cells with 130mM KCl caused loss of both the beaded lines of immunostaining and micro-filaments. Double immunostaining showed ribosomes to be closely associated with microfilaments.

  12. Cortical granule translocation is microfilament mediated and linked to meiotic maturation in the sea urchin oocyte.

    PubMed

    Wessel, Gary M; Conner, Sean D; Berg, Linnea

    2002-09-01

    Cortical granules exocytose after the fusion of egg and sperm in most animals, and their contents function in the block to polyspermy by creating an impenetrable extracellular matrix. Cortical granules are synthesized throughout oogenesis and translocate en masse to the cell surface during meiosis where they remain until fertilization. As the mature oocyte is approximately 125 micro m in diameter (Lytechinus variegatus), many of the cortical granules translocate upwards of 60 micro m to reach the cortex within a 4 hour time window. We have investigated the mechanism of this coordinated vesicular translocation event. Although the stimulus to reinitiate meiosis in sea urchin oocytes is not known, we found many different ways to reversibly inhibit germinal vesicle breakdown, and used these findings to discover that meiotic maturation and cortical granule translocation are inseparable. We also learned that cortical granule translocation requires association with microfilaments but not microtubules. It is clear from endocytosis assays that microfilament motors are functional prior to meiosis, even though cortical granules do not use them. However, just after GVBD, cortical granules attach to microfilaments and translocate to the cell surface. This latter conclusion is based on organelle stratification within the oocyte followed by positional quantitation of the cortical granules. We conclude from these studies that maturation promoting factor (MPF) activation stimulates vesicle association with microfilaments, and is a key regulatory step in the coordinated translocation of cortical granules to the egg cortex.

  13. Cytoplasmic streaming emerges naturally from hydrodynamic self-organisation of a microfilament suspension

    NASA Astrophysics Data System (ADS)

    Woodhouse, Francis; Goldstein, Raymond

    2013-03-01

    Cytoplasmic streaming is the ubiquitous phenomenon of deliberate, active circulation of the entire liquid contents of a plant or animal cell by the walking of motor proteins on polymer filament tracks. Its manifestation in the plant kingdom is particularly striking, where many cells exhibit highly organised patterns of flow. How these regimented flow templates develop is biologically unclear, but there is growing experimental evidence to support hydrodynamically-mediated self-organisation of the underlying microfilament tracks. Using the spirally-streaming giant internodal cells of the characean algae Chara and Nitella as our prototype, we model the developing sub-cortical streaming cytoplasm as a continuum microfilament suspension subject to hydrodynamic and geometric forcing. We show that our model successfully reproduces emergent streaming behaviour by evolving from a totally disordered initial state into a steady characean ``conveyor belt'' configuration as a consequence of the cell geometry, and discuss applicability to other classes of steadily streaming plant cells.

  14. Mitosis in Oedogonium: spindle microfilaments and the origin of the kinetochore fiber.

    PubMed

    Schibler, M J; Pickett-Heaps, J D

    1980-10-01

    New ultrastructural observations of mitosis in the closed spindle of Oedogonium cardiacum have been made using cells fixed with glutaraldehyde and tannic acid. Fine filaments 5 to 8 nm in diameter are attached to kinetochores from prophase through anaphase. Some are free in the early division nucleus while others emanate from forming kinetochores at prophase when few if any microtubules (MTs) are inside the nucleus. During prometaphase, MTs invade the nucleus from the poles and appear to interact with the microfilaments. Early in prometaphase, numerous MTs are laterally associated with kinetochores, and the kinetochore fiber is often formed first at one kinetochore of a pair. During metaphase and anaphase, the microfilaments are interspersed among the MTs of these kinetochore fibers. There also is an ill-defined matrix concentrated in the kinetochore fiber, and MTs are often coated irregularly with osmiophilic material. Live mitotic cells of Oedogonium were studied using time lapse cinematography, and we correlate these observations with the above results. We conclude that these microfilaments may constitute one structural component of the traction apparatus that moves chromosomes during metakinesis and anaphase, and that at least some (and possibly many) of the MTs of the kinetochore fiber are derived from those entering the nucleus at prometaphase.

  15. Cloned pigmented retinal epiehtlium. The role of microfilaments in the differentiation of cell shape

    PubMed Central

    1979-01-01

    3-wk-old clones of pigmented epithelial cells from chick retina can be divided into four zones on the basis of cellular morphology and pigmentation. These zones appear to represent different stages in the re-expression of differentiation: those cells with essentially no differentiated characteristics are at the outer edge and those with the greatest number are at the center. Cells of the colony exhibit three different types of movement when analyzed by time-lapse cinephotomicrography: focal contractions, extension and retraction of apical protrusions, and undulations of the lateral membranes. All the cells of the colony contain microfilaments, 4--7 nm in Diam, which are primarily arranged as apical and basal webs. In addition, less well defined filamentous networks are found in the apical protrusions and lateral interdigitations. When colonies are treated with 10 micrograms/ml of the drug cytochalasin B (CCB), the apical microfilament arrays are disrupted and movement stops. Both phenomena are reversible upon removal of the drug. During the process of redifferentiation, the cells change their shape from squamous to cuboidal, and the greatest change is found where the colony exhibits the greatest number of focal contractions. The evidence suggests that the apical microfilament arrays are directly responsible for the observed movements, particularly the focal contractions, and that focal contractions contribute to the development of the differentiated cellular shape. Possible roles for the other movements are discussed. PMID:572829

  16. [Study of a lysis medium stabilizing microfilaments and microtubules in vitro and in vivo].

    PubMed

    Foucault, G; Raymond, M N; Coffe, G; Pudles, J

    1984-01-01

    Determination of experimental conditions which allow the evaluation of the variations in the ratio of non polymerized and polymerized forms of actin and tubulin during the reorganization of the cytoskeletal cell system is of most valuable importance. In order to prepare cell homogenates which would reflect the in vivo situation, we tested in vitro a lysis medium which stabilized both microfilaments and microtubules, which were determined by DNase inhibition assays and colchicine binding assays respectively. This lysis medium containing 10 mM potassium phosphate, 1mM magnesium chloride, 5 mM EGTA, 1 M hexylene glycol, 1% Triton X-100, pH 6.4, used at 4 degrees C a) diffused rapidly into the cells; b) did not denature actin and tubulin; c) did not displace the equilibrium between non polymerized and polymerized forms of actin and tubulin, allowing biochemical assays on cell homogenates; d) blocked the evolution of the cytoskeletal system and permitted structural studies; e) and allowed the decoration of microfilaments by heavy meromyosin.

  17. Microfilament-organizing centers in areas of cell contact: cytoskeletal interactions during cell attachment and locomotion

    PubMed Central

    Geiger, B.; Avnur, Z.; Rinnerthaler, G.; Hinssen, H.; Small, V. J.

    1984-01-01

    In this article we discuss three aspects of cell contact formation: (a) the molecular architecture of the cytomatrix in cell-to-substrate focal contacts, (b) the dynamic properties of membrane- and microfilament-associated proteins in the contact areas, and (c) the involvement of microtubules in the coordinated and directed formation of new substrate contacts during cell locomotion. We show that different microfilament-associated proteins exhibit distinct patterns of association with focal contacts: some proteins are specifically associated with focal contacts (vinculin and talin); alpha-actinin is enriched in the contact areas but also is present along the stress fibers and in the lamellipodium; actin and filamin are detected throughout the contact areas but in apparently reduced amounts compared with the associated stress fibers; and tropomyosin, myosin, and spectrin are either absent from the endofacial surfaces of contact areas or are present in only very small amounts. Fluorescence photobleaching recovery analyses performed with living cells microinjected with fluorescently labeled actin, vinculin, and alpha-actinin indicate that each of these proteins maintains a dynamic equilibrium between a soluble cytoplasmic pool and a membrane-bound fraction. Correlation of the distribution of vinculin and tubulin in motile fibroblasts to local movements of the leading edge of the same cells indicates that free-end microtubules extend into actively ruffling areas along the lamellipodium and that new vinculin-containing contacts are preferentially formed in these protruding regions. PMID:6430912

  18. Microfilament Orientation Constrains Vesicle Flow and Spatial Distribution in Growing Pollen Tubes

    PubMed Central

    Kroeger, Jens H.; Daher, Firas Bou; Grant, Martin; Geitmann, Anja

    2009-01-01

    Abstract The dynamics of cellular organelles reveals important information about their functioning. The spatio-temporal movement patterns of vesicles in growing pollen tubes are controlled by the actin cytoskeleton. Vesicle flow is crucial for morphogenesis in these cells as it ensures targeted delivery of cell wall polysaccharides. Remarkably, the target region does not contain much filamentous actin. We model the vesicular trafficking in this area using as boundary conditions the expanding cell wall and the actin array forming the apical actin fringe. The shape of the fringe was obtained by imposing a steady state and constant polymerization rate of the actin filaments. Letting vesicle flux into and out of the apical region be determined by the orientation of the actin microfilaments and by exocytosis was sufficient to generate a flux that corresponds in magnitude and orientation to that observed experimentally. This model explains how the cytoplasmic streaming pattern in the apical region of the pollen tube can be generated without the presence of actin microfilaments. PMID:19804712

  19. A single-cell correlative nanoelectromechanosensing approach to detect cancerous transformation: monitoring the function of F-actin microfilaments in the modulation of the ion channel activity

    NASA Astrophysics Data System (ADS)

    AbdolahadThe Authors With Same Contributions., Mohammad; Saeidi, Ali; Janmaleki, Mohsen; Mashinchian, Omid; Taghinejad, Mohammad; Taghinejad, Hossein; Azimi, Soheil; Mahmoudi, Morteza; Mohajerzadeh, Shams

    2015-01-01

    Cancerous transformation may be dependent on correlation between electrical disruptions in the cell membrane and mechanical disruptions of cytoskeleton structures. Silicon nanotube (SiNT)-based electrical probes, as ultra-accurate signal recorders with subcellular resolution, may create many opportunities for fundamental biological research and biomedical applications. Here, we used this technology to electrically monitor cellular mechanosensing. The SiNT probe was combined with an electrically activated glass micropipette aspiration system to achieve a new cancer diagnostic technique that is based on real-time correlation between mechanical and electrical behaviour of single cells. Our studies demonstrated marked changes in the electrical response following increases in the mechanical aspiration force in healthy cells. In contrast, such responses were extremely weak for malignant cells. Confocal microscopy results showed the impact of actin microfilament remodelling on the reduction of the electrical response for aspirated cancer cells due to the significant role of actin in modulating the ion channel activity in the cell membrane.Cancerous transformation may be dependent on correlation between electrical disruptions in the cell membrane and mechanical disruptions of cytoskeleton structures. Silicon nanotube (SiNT)-based electrical probes, as ultra-accurate signal recorders with subcellular resolution, may create many opportunities for fundamental biological research and biomedical applications. Here, we used this technology to electrically monitor cellular mechanosensing. The SiNT probe was combined with an electrically activated glass micropipette aspiration system to achieve a new cancer diagnostic technique that is based on real-time correlation between mechanical and electrical behaviour of single cells. Our studies demonstrated marked changes in the electrical response following increases in the mechanical aspiration force in healthy cells. In contrast, such

  20. Evolution of laser microfilaments in the wake of a femtosecond driving pulse

    NASA Astrophysics Data System (ADS)

    Romanov, D. A.; Levis, R. J.

    2013-06-01

    A theoretical model for subnanosecond evolution of a nonequilibrium, inhomogeneous free-electron gas in a laser filament or microfilament wake channel is presented. The spatial distributions of electron density and temperature calculated in axially symmetric geometry as a function of time reveal dynamics on the picosecond time scale that is principally driven by a combination of thermal conduction in the electron gas and impact ionization of residual neutral atoms. At high laser intensity, the electron density evolves into a widened distribution with a sharp edge while the temperature distribution evolves to a central peak surrounded by a wide plateau. At low laser intensity, little change is seen in the electron density while the temperature again evolves to a wide plateau. The calculations show that the homogeneous electron-density approximation becomes progressively invalid at higher laser intensity. Pump-probe experiments addressing Fraunhofer diffraction patterns, four-wave mixing, and dynamic Rabi sidebands are proposed for experimental verification of the results.

  1. Controlling the reaction between boron-containing sealing glass and a lanthanum-containing cathode by adding Nb2O5

    NASA Astrophysics Data System (ADS)

    Zhao, Dandan; Fang, Lihua; Tang, Dian; Zhang, Teng

    2016-09-01

    In solid oxide fuel cell (SOFC) stacks, the volatile boron species present in the sealing glass often react with the lanthanum-containing cathode, degrading the activity of the cathode (this phenomenon is known as boron poisoning). In this work, we report that this detrimental reaction can be effectively reduced by doping bismuth-containing borosilicate sealing glass-ceramic with a niobium dopant. The addition of Nb2O5 not only condenses the [SiO4] structural units in the glass network, but also promotes the conversion of [BO3] to [BO4]. Moreover, the Nb2O5 dopant enhances the formation of boron-containing phases (Ca3B2O6 and CaB2Si2O8), which significantly reduces the volatility of boron compounds in the sealing glass, suppressing the formation of LaBO3 in the reaction couple between the glass and the cathode. The reported results provide a new approach to solve the problem of boron poisoning.

  2. The association of peroxisomes with the developing cell plate in dividing onion root cells depends on actin microfilaments and myosin.

    PubMed

    Collings, David A; Harper, John D I; Vaughn, Kevin C

    2003-12-01

    We have investigated changes in the distribution of peroxisomes through the cell cycle in onion ( Allium cepa L.) root meristem cells with immunofluorescence and electron microscopy, and in leek ( Allium porrum L.) epidermal cells with immunofluorescence and peroxisomal-targeted green fluorescent protein. During interphase and mitosis, peroxisomes distribute randomly throughout the cytoplasm, but beginning late in anaphase, they accumulate at the division plane. Initially, peroxisomes occur within the microtubule phragmoplast in two zones on either side of the developing cell plate. However, as the phragmoplast expands outwards to form an annulus, peroxisomes redistribute into a ring immediately inside the location of the microtubules. Peroxisome aggregation depends on actin microfilaments and myosin. Peroxisomes first accumulate in the division plane prior to the formation of the microtubule phragmoplast, and throughout cytokinesis, always co-localise with microfilaments. Microfilament-disrupting drugs (cytochalasin and latrunculin), and a putative inhibitor of myosin (2,3-butanedione monoxime), inhibit aggregation. We propose that aggregated peroxisomes function in the formation of the cell plate, either by regulating hydrogen peroxide production within the developing cell plate, or by their involvement in recycling of excess membranes from secretory vesicles via the beta-oxidation pathway. Differences in aggregation, a phenomenon which occurs in onion, some other monocots and to a lesser extent in tobacco BY-2 suspension cells, but which is not obvious in the roots of Arabidopsis thaliana (L.) Heynh., may reflect differences within the primary cell walls of these plants.

  3. MicroFilament Analyzer identifies actin network organizations in epidermal cells of Arabidopsis thaliana roots

    PubMed Central

    Jacques, Eveline; Lewandowski, Michal; Buytaert, Jan; Fierens, Yves; Verbelen, Jean-Pierre; Vissenberg, Kris

    2013-01-01

    The plant cytoskeleton plays a crucial role in the cells’ growth and development during different developmental stages and it undergoes many rearrangements. In order to describe the arrangements of the F-actin cytoskeleton in root epidermal cells of Arabidopsis thaliana, the recently developed software MicroFilament Analyzer (MFA) was exploited. This software enables high-throughput identification and quantification of the orientation of filamentous structures on digital images in a highly standardized and fast way. Using confocal microscopy and transgenic GFP-FABD2-GFP plants the actin cytoskeleton was visualized in the root epidermis. MFA analysis revealed that during the early stages of cell development F-actin is organized in a mainly random pattern. As the cells grow, they preferentially adopt a longitudinal organization, a pattern that is also preserved in the largest cells. In the evolution from young to old cells, an approximately even distribution of transverse, oblique or combined orientations is always present besides the switch from random to a longitudinal oriented actin cytoskeleton. PMID:23656865

  4. Two classes of actin microfilaments are associated with the inner cytoskeleton of axons

    PubMed Central

    1988-01-01

    The distribution and length of actin microfilaments (MF) was determined in axoplasm extruded from the giant axons of the squid (Loligo pealeii). Extruded axoplasm that was separated from the axonal cortex contains approximately 92% of the total axonal actin, and 60% of this actin is polymerized (Morris, J., and R. Lasek. 1984. J. Cell Biol. 98:2064-2076). Localization of MF with rhodamine-phalloidin indicated that the MF were organized in fine columns oriented longitudinally within the axoplasm. In the electron microscope, MF were surrounded by a dense matrix and they were associated with the microtubule domains of the axoplasm. The surrounding matrix tended to obscure the MF which may explain why MF have rarely been recognized before in the inner regions of the axon. The axoplasmic MF are relatively short (number average length of 0.55 micron). Length measurements of MF prepared either in the presence or absence of the actin-filament stabilizing drug phalloidin indicate that axoplasm contains two populations of MF: stable MF (number average length of 0.79 micron) and metastable MF (number average length of 0.41 micron). Although individual axonal MF are much shorter than axonal microtubules, the combined length of the total MF is twice that of the total microtubules. Apparently, these numerous short MF have an important structural role in the architecture of the inner axonal cytoskeleton. PMID:3417765

  5. The Role of Microfilaments in Early Meiotic Maturation of Mouse Oocytes

    NASA Astrophysics Data System (ADS)

    Calarco, Patricia G.

    2005-04-01

    Mouse oocyte microfilaments (MF) were perturbed by depolymerization (cytochalasin B) or stabilization (jasplakinolide) and correlated meiotic defects examined by confocal microscopy. MF, microtubules, and mitochondria were vitally stained; centrosomes ([gamma]-tubulin), after fixation. MF depolymerization by cytochalasin in culture medium did not affect central migration of centrosomes, mitochondria, or nuclear breakdown (GVBD); some MF signal was localized around the germinal vesicle (GV). In maturation-blocking medium (containing IBMX), central movement was curtailed and cortical MF aggregations made the plasma membrane wavy. Occasional long MF suggested that not all MF were depolymerized. MF stabilization by jasplakinolide led to MF aggregations throughout the cytoplasm. GVBD occurred (unless IBMX was present) but no spindle formed. Over time, most oocytes constricted creating a dumbbell shape with MF concentrated under one-half of the oocyte cortex and on either side of the constriction. In IBMX medium, the MF-containing half of the dumbbell over time sequestered the GV, MF, mitochondria, and one to two large cortical centrosomes; the non-MF half appeared empty. Cumulus processes contacted the oocyte surface (detected by microtubule content) and mirrored MF distribution. Results demonstrated that MF play an essential role in meiosis, primarily through cortically mediated events, including centrosome localization, spindle (or GV) movement to the periphery, activation of (polar body) constriction, and establishment of oocyte polarity. The presence of a cortical “organizing pole” is hypothesized.

  6. Cytoplasmic streaming in plant cells emerges naturally by microfilament self-organization.

    PubMed

    Woodhouse, Francis G; Goldstein, Raymond E

    2013-08-27

    Many cells exhibit large-scale active circulation of their entire fluid contents, a process termed cytoplasmic streaming. This phenomenon is particularly prevalent in plant cells, often presenting strikingly regimented flow patterns. The driving mechanism in such cells is known: myosin-coated organelles entrain cytoplasm as they process along actin filament bundles fixed at the periphery. Still unknown, however, is the developmental process that constructs the well-ordered actin configurations required for coherent cell-scale flow. Previous experimental works on streaming regeneration in cells of Characean algae, whose longitudinal flow is perhaps the most regimented of all, hint at an autonomous process of microfilament self-organization driving the formation of streaming patterns during morphogenesis. Working from first principles, we propose a robust model of streaming emergence that combines motor dynamics with both microscopic and macroscopic hydrodynamics to explain how several independent processes, each ineffectual on its own, can reinforce to ultimately develop the patterns of streaming observed in the Characeae and other streaming species.

  7. Microfilament regulatory protein MENA increases activity of RhoA and promotes metastasis of hepatocellular carcinoma.

    PubMed

    Lin, Ling; Yang, Xiao-Mei; Li, Jun; Zhang, Yan-Li; Qin, Wenxin; Zhang, Zhi-Gang

    2014-09-10

    Mammalian enabled (MENA), usually known as a direct regulator of microfilament polymerization and bundling, promotes metastasis in various cancers. Here we focus on the role of MENA in hepatocellular carcinoma (HCC) metastasis and the relevant mechanism from the view of RhoA activity regulation. By HCC tissue microarray analysis, we found that MENA expression was positively associated with satellite lesions (P<0.01) and vascular invasion (P<0.01). Cases with membrane reinforcement of MENA staining in HCC tissues had significantly higher rates of early recurrence in the intermediate MENA expression group. Knockdown of MENA significantly suppressed HCC cell migration and invasion in vitro, as well as their intrahepatic and distant metastasis in vivo. Knockdown of MENA also decreased filopodia and stress fibers in SMMC-7721 cells. Furthermore, a decrease of RhoA activity was detected by a pull-down assay in SMMC-7721-shMENA cells. The ROCK inhibitor, Y-27632, suppressed migration of both MENA knockdown SMMC-7721 cells and control cells, but diminished their difference. Thus, our findings suggest that MENA promotes HCC cell motility by activating RhoA.

  8. Microtubules and Microfilaments in Fixed and Permeabilized Cells are Selectively Decorated by Nerve Growth Factor

    NASA Astrophysics Data System (ADS)

    Nasi, S.; Cirillo, D.; Naldini, L.; Marchisio, P. C.; Calissano, P.

    1982-02-01

    A specific antibody against nerve growth factor (NGF) and indirect immunofluorescence microscopy have been used to follow the in vitro binding of NGF to cells made permeable to large molecules. All cells tested, both target (sensory neurons and PC12 cells) and nontarget (3T3, BKH 2I, C6 glioma cells), revealed a decoration of cytoskeletal structures which on the basis of their form, reactivity with antibodies, and sensitivity to specific drugs may be identified as microtubules (MTs) and microfilaments (MFs). The decoration of either structure depends on the fixation and permeabilization conditions: MFs, in the form of stress fibers, are stained by NGF when the plasma membrane is permeabilized with methanol/acetone; MTs become intensely stained when the plasma membrane is solubilized with a nonionic detergent in the presence of a MT-stabilizing medium. The two procedures do not affect the staining of these structures with specific antibodies. Binding of 125I-labeled NGF to PC12 cells was not competitively inhibited by a 100-fold excess of several positively charged proteins but it was markedly decreased in the presence of DNase I. 125I-Labeled NGF interacted with MTs and F-actin (fixed with paraformaldehyde) in a range of concentrations similar to that used for their cellular localization with NGF-anti-NGF. Our studies show that the specificity and affinity of NGF binding to MTs and MFs is in the range of that of antibodies against tubulin and actin. The possible relevance of these findings to the mechanism of action of NGF in target cells is discussed.

  9. Ezrin: a regulator of actin microfilaments in cell junctions of the rat testis

    PubMed Central

    Gungor-Ordueri, N Ece; Celik-Ozenci, Ciler; Cheng, C Yan

    2015-01-01

    Ezrin, radixin, moesin and merlin (ERM) proteins are highly homologous actin-binding proteins that share extensive sequence similarity with each other. These proteins tether integral membrane proteins and their cytoplasmic peripheral proteins (e.g., adaptors, nonreceptor protein kinases and phosphatases) to the microfilaments of actin-based cytoskeleton. Thus, these proteins are crucial to confer integrity of the apical membrane domain and its associated junctional complex, namely the tight junction and the adherens junction. Since ectoplasmic specialization (ES) is an F-actin-rich testis-specific anchoring junction-a highly dynamic ultrastructure in the seminiferous epithelium due to continuous transport of germ cells, in particular spermatids, across the epithelium during the epithelial cycle-it is conceivable that ERM proteins are playing an active role in these events. Although these proteins were first reported almost 25 years and have since been extensively studied in multiple epithelia/endothelia, few reports are found in the literature to examine their role in the actin filament bundles at the ES. Studies have shown that ezrin is also a constituent protein of the actin-based tunneling nanotubes (TNT) also known as intercellular bridges, which are transient cytoplasmic tubular ultrastructures that transport signals, molecules and even organelles between adjacent and distant cells in an epithelium to coordinate cell events that occur across an epithelium. Herein, we critically evaluate recent data on ERM in light of recent findings in the field in particular ezrin regarding its role in actin dynamics at the ES in the testis, illustrating additional studies are warranted to examine its physiological significance in spermatogenesis. PMID:25652626

  10. Evaluation of the effect of adding micro-hydroxyapatite and nano-hydroxyapatite on the microleakage of conventional and resin-modified Glass-ionomer Cl V restorations

    PubMed Central

    Sharafeddin, Farahnaz

    2017-01-01

    Background Pulpal reaction to restorative materials depends on marginal microleakage, which is a dynamic phenomenon that allows bacteria and fluids to traverse across the tooth-restoration interface. Glass-ionomer cement (GIC) exhibits low microleakage due to direct bonding to tooth structures. Hydroxyapatite (HAP) based on the similarity with tooth structure may decrease the microleakage. The aim of this in vitro study was to evaluate marginal microleakage of a mixture of conventional and resin-modified glass-ionomer (RMGI) with micro- and nano-HAP. Material and Methods In this in vitro study, 30 non-carious extracted human third molar teeth were used. Standard Cl V cavities were prepared on the buccal and lingual surfaces. The cavities were restored in six experimental groups as follows: group 1, conventional glass-ionomer cement (CGIC); group 2, CGIC with micro-HAP; group 3, CGIC with nano-HAP; group 4, RMGI; group 5, RMGI with micro-HAP; group 6, RMGI with nano-HAP. The restorations were finished and polished. The teeth were coated with nail polish, sealed with sticky wax, thermocycled and placed in a solution of 2% basic fuchsine for 24 hours. The teeth were sectioned and microleakage was measured. Kruskal-Wallis, Man-Whitney and Wilcoxon tests were used for data analysis (P<0.05). Results The data analysis revealed significantly lower microleakage in groups 5 and 6 at both occlusal and gingival margins. Also in these two groups the gingival microleakage was significantly lower than occlusal margin (P=0.009 and P=0.001 respectively), but in groups 1(CGIC) and 3(CGIC+ nano-HAP) and 4(RMGI) the microleakage of occlusal margin were significantly lower than that of gingival margin (P=0.001, P=0.007 and P=0.001 respectively). Conclusions Mixing RMGI with nano-HAP and micro-HAP resulted in lower microleakage. Key words:Glass-ionomer, micro-hydroxyapatite, microleakage, nano-hydroxyapatite. PMID:28210443

  11. A genetic screen for suppressors and enhancers of the Drosophila cdk1-cyclin B identifies maternal factors that regulate microtubule and microfilament stability.

    PubMed Central

    Ji, Jun-Yuan; Haghnia, Marjan; Trusty, Cory; Goldstein, Lawrence S B; Schubiger, Gerold

    2002-01-01

    Coordination between cell-cycle progression and cytoskeletal dynamics is important for faithful transmission of genetic information. In early Drosophila embryos, increasing maternal cyclin B leads to higher Cdk1-CycB activity, shorter microtubules, and slower nuclear movement during cycles 5-7 and delays in nuclear migration to the cortex at cycle 10. Later during cycle 14 interphase of six cycB embryos, we observed patches of mitotic nuclei, chromosome bridges, abnormal nuclear distribution, and small and large nuclei. These phenotypes indicate disrupted coordination between the cell-cycle machinery and cytoskeletal function. Using these sensitized phenotypes, we performed a dosage-sensitive genetic screen to identify maternal proteins involved in this process. We identified 10 suppressors classified into three groups: (1) gene products regulating Cdk1 activities, cdk1 and cyclin A; (2) gene products interacting with both microtubules and microfilaments, Actin-related protein 87C; and (3) gene products interacting with microfilaments, chickadee, diaphanous, Cdc42, quail, spaghetti-squash, zipper, and scrambled. Interestingly, most of the suppressors that rescue the astral microtubule phenotype also reduce Cdk1-CycB activities and are microfilament-related genes. This suggests that the major mechanism of suppression relies on the interactions among Cdk1-CycB, microtubule, and microfilament networks. Our results indicate that the balance among these different components is vital for normal early cell cycles and for embryonic development. Our observations also indicate that microtubules and cortical microfilaments antagonize each other during the preblastoderm stage. PMID:12454065

  12. Enrichment of distinct microfilament-associated and GTP-binding-proteins in membrane/microvilli fractions from lymphoid cells

    PubMed Central

    Hao, Jian-Jiang; Wang, Guanghui; Pisitkun, Trairak; Patino-Lopez, Genaro; Nagashima, Kunio; Knepper, Mark A.; Shen, Rong-Fong; Shaw, Stephen

    2008-01-01

    Summary Lymphocyte microvilli mediate initial adhesion to endothelium during lymphocyte transition from blood into tissue but their molecular organization is incompletely understood. We modified a shear-based procedure to prepare biochemical fractions enriched for membrane/microvilli (MMV) from both human peripheral blood T-lymphocytes (PBT) and a mouse pre-B lymphocyte line (300.19). Enrichment of proteins in MMV relative to post nuclear lysate was determined by LC/MS/MS analysis and label-free quantitation. Subsequent analysis emphasized the 291 proteins shared by PBT and 300.19 and estimated by MS peak area to be highest abundance. Validity of the label-free quantitation was confirmed by many internal consistencies and by comparison with Western blot analyses. The MMV fraction was enriched primarily for subsets of cytoskeletal proteins, transmembrane proteins and G-proteins, with similar patterns in both lymphoid cell types. The most enriched cytoskeletal proteins were microfilament-related proteins NHERF1, Ezrin/Radixin/Moesin (ERMs), ADF/cofilin and Myosin1G. Other microfilament proteins such as talin, gelsolin, myosin II and profilin were markedly reduced in MMV, as were intermediate filament- and microtubule-related proteins. Heterotrimeric G-proteins and some small G-proteins (especially Ras and Rap1) were enriched in the MMV preparation. Two notable general observations also emerged. There was less overlap between the two cells in their transmembrane proteins than in other classes of proteins, consistent with a special role of plasma membrane proteins in differentiation. Second, unstimulated primary T-lymphocytes have an unusually high concentration of actin and other microfilament related proteins, consistent with the singular role of actin-mediated motility in the immunological surveillance performed by these primary cells. Lymphocyte microvilli initiate adhesion to endothelium during movement from blood into tissue. Using LC/MS/MS and label

  13. Low-temperature sintering and microwave dielectric properties of Ca[(Li1/3Nb2/3)0.8Ti0.2]3- δ with glass frit added

    NASA Astrophysics Data System (ADS)

    In, Chi-Seung; Yeo, Dong-Hun; Shin, Hyo-Soon; Nahm, Sahn; Choi, Won-Youl

    2015-04-01

    In accordance with the trend for mobile terminals to be high intensity and to have thinner layers, low temperature co-fired ceramics (LTCC) materials with outstanding dielectric loss characteristics and diverse dielectric constants have been in demand, and the need for high-strength materials that can withstand external shocks has increased. Ca[(Li1/3Nb2/3)1- x Ti x ]O3- δ (CLNT) has a quality factor over 14,000 and τ f ≤ 10 when the dielectric constant is 41 ˜ 46, but its sintering temperature is high at 1150 °C. Therefore, it cannot be used as a LTCC component. This study aimed to lower the sintering temperature to 900 °C by adding a low-melting-point glass such as B2O3·SiO2·BaO and B2O3·SiO2·Al2O3. As the glass content in CLNT was increased from 10 wt% to 20 wt%, the density and the Q·f0 property decreased, and the dielectric constant rose. When B2O3·SiO2·BaO was added to CLNT at 15 wt%, the dielectric constant was found to be 27, the Q·f0 property to be 3470, and the τ f to be -18 ppm/°C. When B2O3·SiO2·Al2O3 was added to CLNT at 10 wt%, the dielectric constant was 20, the Q·f0 property was 3990, and the τ f was -15 ppm/°C. As such, in both cases, excellent dielectric properties were observed.

  14. Quantitative analysis of changes in actin microfilament contribution to cell plate development in plant cytokinesis

    PubMed Central

    Higaki, Takumi; Kutsuna, Natsumaro; Sano, Toshio; Hasezawa, Seiichiro

    2008-01-01

    Background Plant cells divide by the formation of new cross walls, known as cell plates, from the center to periphery of each dividing cell. Formation of the cell plate occurs in the phragmoplast, a complex structure composed of membranes, microtubules (MTs) and actin microfilaments (MFs). Disruption of phragmoplast MTs was previously found to completely inhibit cell plate formation and expansion, indicative of their crucial role in the transport of cell plate membranes and materials. In contrast, disruption of MFs only delays cell plate expansion but does not completely inhibit cell plate formation. Despite such findings, the significance and molecular mechanisms of MTs and MFs remain largely unknown. Results Time-sequential changes in MF-distribution were monitored by live imaging of tobacco BY-2 cells stably expressing the GFP-actin binding domain 2 (GFP-ABD2) fusion protein, which vitally co-stained with the endocytic tracer, FM4-64, that labels the cell plate. During cytokinesis, MFs accumulated near the newly-separated daughter nuclei towards the emerging cell plate, and subsequently approached the expanding cell plate edges. Treatment with an actin polymerization inhibitor caused a decrease in the cell plate expansion rate, which was quantified using time-lapse imaging and regression analysis. Our results demonstrated time-sequential changes in the contribution of MFs to cell plate expansion; MF-disruption caused about a 10% decrease in the cell plate expansion rate at the early phase of cytokinesis, but about 25% at the late phase. MF-disruption also caused malformation of the emerging cell plate at the early phase, indicative of MF involvement in early cell plate formation and expansion. The dynamic movement of endosomes around the cell plate was also inhibited by treatment with an actin polymerization inhibitor and a myosin ATPase inhibitor, respectively. Furthermore, time-lapse imaging of the endoplasmic reticulum (ER) revealed that MFs were involved in

  15. A stochastic thermostat algorithm for coarse-grained thermomechanical modeling of large-scale soft matters: Theory and application to microfilaments

    SciTech Connect

    Li, Tong; Gu, YuanTong

    2014-04-15

    As all-atom molecular dynamics method is limited by its enormous computational cost, various coarse-grained strategies have been developed to extend the length scale of soft matters in the modeling of mechanical behaviors. However, the classical thermostat algorithm in highly coarse-grained molecular dynamics method would underestimate the thermodynamic behaviors of soft matters (e.g. microfilaments in cells), which can weaken the ability of materials to overcome local energy traps in granular modeling. Based on all-atom molecular dynamics modeling of microfilament fragments (G-actin clusters), a new stochastic thermostat algorithm is developed to retain the representation of thermodynamic properties of microfilaments at extra coarse-grained level. The accuracy of this stochastic thermostat algorithm is validated by all-atom MD simulation. This new stochastic thermostat algorithm provides an efficient way to investigate the thermomechanical properties of large-scale soft matters.

  16. Photoprotection: clothing and glass.

    PubMed

    Almutawa, Fahad; Buabbas, Hanan

    2014-07-01

    Ultraviolet (UV) radiation (UVR) has well-known adverse effects on the skin and eyes. Little attention is given to physical means of photoprotection, namely glass, window films, sunglasses, and clothing. In general, all types of glass block UV-B. For UV-A, the degree of transmission depends on the type, thickness, and color of the glass. Adding window films to glass can greatly decrease the transmission of UV-A. Factors that can affect the transmission of UVR through cloth include tightness of weave, thickness, weight, type of fabrics, laundering, hydration, stretch, fabric processing, UV absorbers, color, and fabric-to-skin distance.

  17. Developing photorefractive glass composites

    NASA Astrophysics Data System (ADS)

    Duignan, Jason P.; Taylor, Lesley L.; Cook, Gary

    2002-01-01

    The production of a transparent photorefractive glass composite would offer a useful alternative to bulk crystal materials. We aim to produce such a material by incorporating single domain photorefractive Fe:LiNbO3 particles into a refractive index matched glass host. This glass host is also required to be chemically compatible with the photorefractive material. This compatibility will ensure that the Fe:LiNbO3 particles added to the host glass will remain in the intended crystalline phase and not simply dissolve in the glass. Due to the high refractive index of the Fe:LiNbO3 (no equals 2.35 532 nm), producing a chemically compatible and refractive index matched glass host is technically challenging. By examining common Tellurite, Bismuthate, and Gallate glasses as a starting point and then developing new and hybrid glasses, we have succeeded in producing a chemically compatible glass host and also a refractive index matched glass host. We have produced preliminary glass composite samples which contain a large amount of Fe:LiNbO3. We are currently able to retain nearly 90% of the incorporated Fe:LiNbO3 in the correct crystalline phase, a substantial improvement over previous work conducted in this area in recent years. In this paper we present our progress and findings in this area.

  18. Effects of Phorbol Esters and Lipopolysaccharide on Endothelial Cell Microfilaments: Laser Scanning Confocal Microscopy and Quantitative Morphometry of Dose Dependent Changes

    DTIC Science & Technology

    1988-11-29

    the same ECmo (1-5 nM) for both biochemical and morphological processes. -PDB was less potent in inducing the disruption of microfilament structure...but the agent was less potent than PMA, with an ECmo of about 80 nM. The agent 4a-phorbol, which is not a tumor-promoter, had no effect on the

  19. A novel anti-microfilament antibody, anti-135 kD, is associated with Raynaud's disease, undifferentiated connective tissue disease and systemic autoimmune diseases.

    PubMed

    Girard, D; Senécal, J L

    1996-01-01

    We report herein the characterization of a human IgG antibody reactive with a nonmuscle 135 kD microfilament-associated protein, anti-135 kD. Using nonmuscle epithelial PtK2 cells as substrate in indirect immunofluorescence, we identified a distinctive pattern of reactivity with microfilaments in sera from 12 of 165 (7.3%) patients investigated for systemic autoimmune diseases and in only 2 of 171 (1.2%) normal and rheumatic disease controls (P < 0.006, 95% Cl 1.46 to 30.1). An association between anti-135 kD and Raynaud's phenomenon (n = 12/14, 85.7%) with or without an associated systemic autoimmune disease was noted. The anti-135 kD specificity was established by several criteria. (1) The fluorescence was periodically distributed along microfilaments and concentrated at focal adhesions for all sera (n = 14). (2) On immunoblots, the 14 sera reacted with a PtK2 polypeptide of 135 kD. (3) IgG purified by blot-affinity from the 135 kD band (alpha-135) reproduced the fluorescent pattern of the original sera while IgG purified from other bands did not. (4) Double immunofluorescence with alpha-135 and anti-alpha-actinin mAb indicated absence of antibody fluorescence at ruffling membranes where a-actinin was distributed. (5) IgG subclass analysis of anti-135 kD revealed that 12 (85.7%) sera are of IgG3 isotype and 2 (14.3%) are of IgG1 isotype while the light chain expression was kappa restricted. This is the first report of an antibody to a 135 kD microfilament protein. Anti-135 kD expand the repertoire of anti-microfilament and anticytoskeletal antibodies in human sera.

  20. Enhancing the value of commodity polymers: Part 1. Structure-property relationships in composite materials based on maleated polypropylene/inorganic phosphate glasses. Part 2. New value-added applications for polyesters

    NASA Astrophysics Data System (ADS)

    Gupta, Mohit

    The first part of the thesis (Chapters 2 & 3) describes a new class of organic polymer/inorganic glass composite materials with property improvements that are impossible to achieve with classical polymer blends or composites. These materials exhibit good processability, superior mechanical performance, good thermal stability, and have excellent gas barrier properties. Low glass transition temperature phosphate glasses (Pglass) are used as inorganic fillers and slightly maleated polypropylene is used as the organic polymer matrix. The Pglass, which was dispersed as spherical droplets in the unoriented composites can be elongated into high aspect ratio platelets during the biaxial stretching process. Biaxially oriented films exhibited a brick wall type microstructure with highly aligned inorganic platelets in a ductile organic matrix and the oxygen barrier properties are significantly improved due to presence of Pglass platelets as impermeable inclusions. Mechanical properties of the biaxially oriented films showed significant improvements compared to neat polymer due to uniform dispersion of the Pglass platelets. Properly dispersed and aligned platelets have proven to be very effective for increasing the composite modulus. These developed materials therefore show promise to help fulfill the ever increasing demand for new advanced materials for a wide variety of advanced packaging applications because of their gas barrier properties, flexibility, transparency, mechanical strength and performance under humid conditions. The second part of the thesis (Chapters 4 & 5) describes new value-added applications for polyesters. Chapter 4 reports a novel process for the decolorization of green and blue colored PET bottle flakes using hydrogen peroxide. The decolorized flakes were characterized for color, intrinsic viscosity values. Decolorized flakes exhibited color values similar to those of colorless recycled PET and even though IV values decreased, bleached flakes still

  1. Containerless Manufacture of Glass Optical Fibers

    NASA Technical Reports Server (NTRS)

    Naumann, R. J.; Ethridge, E. C.

    1985-01-01

    Contamination and crystallization reduced in proposed process. Solid optical fiber drawn from an acoustically levitated lump of molten glass. New material added in solid form, melted and then moved into main body of molten glass. Single axis acoustic levitation furnances levitate glass melts at temperature up to about 700 degrees C. Processing in unit limited to low-melting temperature glasses.

  2. Hairy AdS solitons

    NASA Astrophysics Data System (ADS)

    Anabalón, Andrés; Astefanesei, Dumitru; Choque, David

    2016-11-01

    We construct exact hairy AdS soliton solutions in Einstein-dilaton gravity theory. We examine their thermodynamic properties and discuss the role of these solutions for the existence of first order phase transitions for hairy black holes. The negative energy density associated to hairy AdS solitons can be interpreted as the Casimir energy that is generated in the dual filed theory when the fermions are antiperiodic on the compact coordinate.

  3. Display innovations through glass

    NASA Astrophysics Data System (ADS)

    Hamilton, Lori L.

    2016-03-01

    Prevailing trends in thin, lightweight, high-resolution, and added functionality, such as touch sensing, continue to drive innovation in the display market. While display volumes grow, so do consumers’ need for portability, enhanced optical performance, and mechanical reliability. Technical advancements in glass design and process have enabled display innovations in these areas while supporting industry growth. Opportunities for further innovation remain open for glass manufacturers to drive new applications, enhanced functionality, and increased demand.

  4. Metallic glass composition

    DOEpatents

    Kroeger, Donald M.; Koch, Carl C.

    1986-01-01

    A metallic glass alloy that is either iron-based or nickel-based or based on a mixture of iron and nickel, containing lesser amounts of elements selected from the group boron, silicon carbon and phosphorous to which is added an amount of a ductility enhancing element selected from the group cerium, lanthanum, praseodymium and neodymium sufficient to increase ductility of the metallic glass upon annealing.

  5. The mammalian G protein rhoC is ADP-ribosylated by Clostridium botulinum exoenzyme C3 and affects actin microfilaments in Vero cells.

    PubMed

    Chardin, P; Boquet, P; Madaule, P; Popoff, M R; Rubin, E J; Gill, D M

    1989-04-01

    Clostridium botulinum C3 is a recently discovered exoenzyme that ADP-ribosylates a eukaryotic GTP-binding protein of the ras superfamily. We show now that the bacterially-expressed product of the human rhoC gene is ADP-ribosylated by C3 and corresponds in size, charge and behavior to the dominant C3 substrate of eukaryotic cells. C3 treatment of Vero cells results in the disappearance of microfilaments and in actinomorphic shape changes without any apparent direct effect upon actin. Thus the ADP-ribosylation of a rho protein seems to be responsible for microfilament disassembly and we infer that the unmodified form of a rho protein may be involved in cytoskeletal control.

  6. Fabrication of glass microspheres with conducting surfaces

    DOEpatents

    Elsholz, W.E.

    1982-09-30

    A method for making hollow glass microspheres with conducting surfaces by adding a conducting vapor to a region of the glass fabrication furnace. As droplets or particles of glass forming material pass through multiple zones of different temperature in a glass fabrication furnace, and are transformed into hollow glass microspheres, the microspheres pass through a region of conducting vapor, forming a conducting coating on the surface of the microspheres.

  7. Fabrication of glass microspheres with conducting surfaces

    DOEpatents

    Elsholz, William E.

    1984-01-01

    A method for making hollow glass microspheres with conducting surfaces by adding a conducting vapor to a region of the glass fabrication furnace. As droplets or particles of glass forming material pass through multiple zones of different temperature in a glass fabrication furnace, and are transformed into hollow glass microspheres, the microspheres pass through a region of conducting vapor, forming a conducting coating on the surface of the microspheres.

  8. Added Sugars

    MedlinePlus

    ... need sugar to function properly. Added sugars contribute zero nutrients but many added calories that can lead to extra pounds or even obesity, thereby reducing heart health. If you think of your daily calorie needs as a budget, you want to “spend” ...

  9. Value Added?

    ERIC Educational Resources Information Center

    UCLA IDEA, 2012

    2012-01-01

    Value added measures (VAM) uses changes in student test scores to determine how much "value" an individual teacher has "added" to student growth during the school year. Some policymakers, school districts, and educational advocates have applauded VAM as a straightforward measure of teacher effectiveness: the better a teacher,…

  10. The force induced by organelles' weight in the microfilament is in the range of 0.1-1 pN

    NASA Astrophysics Data System (ADS)

    Yang, Chun; Wei, Dong; Zhuang, Feng Y.

    It has been well documented that a microgravity environment can bring about many changes in cell metabolism. Can mammalian cells feel the gravity directly? At present, arguments surrounding the problem are difficult to be answered through experiments. However, using finite element simulation to estimate the force exerted on the microfilament meshwork model, we demonstrated a possible way through which gravity acts on the cytoskeleton system. This system, which includes microfilaments, microtubules, and intermediate filaments, is responsible for the retention of cell shape and plays a role in many aspects related to cell proliferation and function. Many organelles, such as ribosomes and nucleus, are deposited, hinged, or attached on the cytoskeleton system. The weight of organelles can deform the cytoskeleton system and can induce force in it. Simulation results showed that the force induced by organelles' weight in the microfilament is in the range of 0.1-1 pN. The magnitude of the force is near the single Van der Waals bond force between the proteins, which is large enough to influence the hinge motion of proteins.

  11. Single microfilaments mediate the early steps of microtubule bundling during preprophase band formation in onion cotyledon epidermal cells.

    PubMed

    Takeuchi, Miyuki; Karahara, Ichirou; Kajimura, Naoko; Takaoka, Akio; Murata, Kazuyoshi; Misaki, Kazuyo; Yonemura, Shigenobu; Staehelin, L Andrew; Mineyuki, Yoshinobu

    2016-06-01

    The preprophase band (PPB) is a cytokinetic apparatus that determines the site of cell division in plants. It originates as a broad band of microtubules (MTs) in G2 and narrows to demarcate the future division site during late prophase. Studies with fluorescent probes have shown that PPBs contain F-actin during early stages of their development but become actin depleted in late prophase. Although this suggests that actins contribute to the early stages of PPB formation, how actins contribute to PPB-MT organization remains unsolved. To address this question, we used electron tomography to investigate the spatial relationship between microfilaments (MFs) and MTs at different stages of PPB assembly in onion cotyledon epidermal cells. We demonstrate that the PPB actins observed by fluorescence microscopy correspond to short, single MFs. A majority of the MFs are bound to MTs, with a subset forming MT-MF-MT bridging structures. During the later stages of PPB assembly, the MF-mediated links between MTs are displaced by MT-MT linkers as the PPB MT arrays mature into tightly packed MT bundles. On the basis of these observations, we propose that the primary function of actins during PPB formation is to mediate the initial bundling of the PPB MTs.

  12. VLN2 Regulates Plant Architecture by Affecting Microfilament Dynamics and Polar Auxin Transport in Rice[OPEN

    PubMed Central

    Wu, Shengyang; Xie, Yurong; Guo, Xiuping; Sheng, Peike; Wang, Juan; Wu, Chuanyin; Wang, Haiyang; Wan, Jianmin

    2015-01-01

    As a fundamental and dynamic cytoskeleton network, microfilaments (MFs) are regulated by diverse actin binding proteins (ABPs). Villins are one type of ABPs belonging to the villin/gelsolin superfamily, and their function is poorly understood in monocotyledonous plants. Here, we report the isolation and characterization of a rice (Oryza sativa) mutant defective in VILLIN2 (VLN2), which exhibits malformed organs, including twisted roots and shoots at the seedling stage. Cellular examination revealed that the twisted phenotype of the vln2 mutant is mainly caused by asymmetrical expansion of cells on the opposite sides of an organ. VLN2 is preferentially expressed in growing tissues, consistent with a role in regulating cell expansion in developing organs. Biochemically, VLN2 exhibits conserved actin filament bundling, severing and capping activities in vitro, with bundling and stabilizing activity being confirmed in vivo. In line with these findings, the vln2 mutant plants exhibit a more dynamic actin cytoskeleton network than the wild type. We show that vln2 mutant plants exhibit a hypersensitive gravitropic response, faster recycling of PIN2 (an auxin efflux carrier), and altered auxin distribution. Together, our results demonstrate that VLN2 plays an important role in regulating plant architecture by modulating MF dynamics, recycling of PIN2, and polar auxin transport. PMID:26486445

  13. Single microfilaments mediate the early steps of microtubule bundling during preprophase band formation in onion cotyledon epidermal cells

    PubMed Central

    Takeuchi, Miyuki; Karahara, Ichirou; Kajimura, Naoko; Takaoka, Akio; Murata, Kazuyoshi; Misaki, Kazuyo; Yonemura, Shigenobu; Staehelin, L. Andrew; Mineyuki, Yoshinobu

    2016-01-01

    The preprophase band (PPB) is a cytokinetic apparatus that determines the site of cell division in plants. It originates as a broad band of microtubules (MTs) in G2 and narrows to demarcate the future division site during late prophase. Studies with fluorescent probes have shown that PPBs contain F-actin during early stages of their development but become actin depleted in late prophase. Although this suggests that actins contribute to the early stages of PPB formation, how actins contribute to PPB-MT organization remains unsolved. To address this question, we used electron tomography to investigate the spatial relationship between microfilaments (MFs) and MTs at different stages of PPB assembly in onion cotyledon epidermal cells. We demonstrate that the PPB actins observed by fluorescence microscopy correspond to short, single MFs. A majority of the MFs are bound to MTs, with a subset forming MT-MF-MT bridging structures. During the later stages of PPB assembly, the MF-mediated links between MTs are displaced by MT-MT linkers as the PPB MT arrays mature into tightly packed MT bundles. On the basis of these observations, we propose that the primary function of actins during PPB formation is to mediate the initial bundling of the PPB MTs. PMID:27053663

  14. Glass sealing

    SciTech Connect

    Brow, R.K.; Kovacic, L.; Chambers, R.S.

    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.

  15. Characterization of Glass Fiber Separator Material for Lithium Batteries

    NASA Technical Reports Server (NTRS)

    Subbarao, S.; Frank, H.

    1984-01-01

    Characterization studies were carried out on a glass fiber paper that is currently employed as a separator material for some LiSOCl2 primary cells. The material is of the non-woven type made from microfilaments of E-type glass and contains an ethyl acrylate binder. Results from extraction studies and tensile testing revealed that the binder content and tensile strength of the paper were significantly less than values specified by the manufacturer. Scanning electron micrographs revealed the presence of clusters of impurities many of which were high in iron content. Results of emission spectroscopy revealed high overall levels of iron and leaching, followed by atomic absorption measurements, revealed that essentially all of this iron is soluble in SOCl2.

  16. Analysis of early medieval glass beads - Glass in the transition period

    NASA Astrophysics Data System (ADS)

    Šmit, Žiga; Knific, Timotej; Jezeršek, David; Istenič, Janka

    2012-05-01

    Glass beads from graves excavated in Slovenia and dated archaeologically to the 7th-10th century AD were analysed by the combined PIXE-PIGE method. The results indicate two groups of glass; natron glass made in the Roman tradition and glass made with alkalis from the ash of halophytic plants, which gradually replaced natron glass after c. 800 AD. The alkalis used in the second group of glass seem to be in close relation to a variant of the Venetian white glass that appeared several centuries later. The origin of this glass may be traced to glass production in Mesopotamia and around the Aral Sea. All the mosaic beads with eye decoration, as well as most of the drawn-segmented and drawn-cut beads analysed, are of plant-ash glass, which confirms their supposed oriental origin.

  17. Adding Value.

    ERIC Educational Resources Information Center

    Orsini, Larry L.; Hudack, Lawrence R.; Zekan, Donald L.

    1999-01-01

    The value-added statement (VAS), relatively unknown in the United States, is used in financial reports by many European companies. Saint Bonaventure University (New York) has adapted a VAS to make it appropriate for not-for-profit universities by identifying stakeholder groups (students, faculty, administrators/support personnel, creditors, the…

  18. Crystallization of a barium-aluminosilicate glass

    NASA Technical Reports Server (NTRS)

    Drummond, C. H., III; Lee, W. E.; Bansal, N. P.; Hyatt, M. J.

    1989-01-01

    The crystallization of a celsian glass composition was investigated as a possible high-temperature ceramic matrix material. Heat treatments invariably resulted in crystallization of the hexaclesian phase unless a flux, such as lithia, was added or a nucleating agent used (e.g., celsian seeds). TEM analysis revealed complex microstructures. Glasses with Mo additions contained hexacelsian, mullite, and an Mo-rich glass. Li2O additions stabilized celsian but mullite and Mo-rich glass were still present.

  19. Glass recycling

    SciTech Connect

    Dalmijn, W.L.; Houwelingen, J.A. van

    1995-12-31

    Glass recycling in the Netherlands has grown from 10,000 to 300,000 tonnes per annum. The various advantages and problems of the glass cycle with reference to the state of the art in the Netherlands is given. Special attention is given to new technologies for the automated sorting of cullet with detection systems. In Western Europe the recycling of glass has become a success story. Because of this, the percentage of glass cullet used in glass furnaces has increased. To meet the quality demands of the glass industry, automated sorting for the removal of stones, non-ferrous metals and other impurities had to be developed and incorporated in glass recycling plants. In Holland, Germany and other countries, the amount of glass collected has reached a level that color-sorting becomes necessary to avoid market saturation with mixed cullet. Recently, two systems for color-sorting have been developed and tested for the separation of bottles and cullet in the size range of 20--50 mm. With the increased capacity of the new glass recycling plants, 120,000--200,000 tpy, the quality systems have also to be improved and automated. These quality control systems are based on the automated sorting technology developed earlier for the glass recycling plants. The data obtained are automatically processed and printed. The sampling system and its relation to the theory of Gy will be described. Results of both developments in glass recycling plants will be described.

  20. Glass Artworks

    NASA Technical Reports Server (NTRS)

    1988-01-01

    Several NASA technologies have played part in growth and cost containment of studio glass art, among them a foam type insulation developed to meet a need for lightweight material that would reduce flame spread in aircraft fire. Foam comes in several forms and is widely used by glass artists, chiefly as an insulator for the various types of ovens used in glass working. Another Spinoff is alumina crucibles to contain molten glass. Before alumina crucibles were used, glass tanks were made of firebrick which tended to erode under high temperatures and cause impurities; this not only improved quality but made the process more cost effective. One more NASA technology that found its way into glass art working is a material known as graphite board, a special form of graphite originally developed for rocket motor applications. This graphite is used to exact compound angles and creates molds for poured glass artworks of dramatic design.

  1. Inhibition of myosin/moesin phosphatase by expression of the phosphoinhibitor protein CPI-17 alters microfilament organization and retards cell spreading.

    PubMed

    Eto, M; Wong, L; Yazawa, M; Brautigan, D L

    2000-07-01

    Cell migration and cytokinesis require reorganization of the cytoskeleton, involving phosphorylation and dephosphorylation of proteins such as myosin II and moesin. Myosin and moesin bind directly to a regulatory subunit of myosin/moesin phosphatase (MMP) that contains a protein type-1 phosphatase (PP1) catalytic subunit. Here we examined the role of MMP in cytoskeletal dynamics using a phosphorylation-dependent inhibitor protein specific for MMP, called CPI-17. Fibroblasts do not express CPI-17, making them a null background to study effects of expression. Wild type CPI-17 in rat embryo fibroblasts caused (1) abnormal accumulation of cortical F-actin fibers, distinct from the stress fibers induced by expression of active RhoA; (2) progressive contraction of cell area, leaving behind filamentous extensions that stained for F-actin and moesin, but not myosin; and (3) significantly retarded spreading of fibroblasts on fibronectin with elevated myosin II light chain phosphorylation. A phosphorylation site mutant CPI-17(T38A) and inhibitor-2 (Inh2), another PP1-specific inhibitor protein, served as controls and did not elicit these same responses when expressed at the same level as CPI-17. Inhibition of myosin light chain kinase by ML-9 prevented the abnormal accumulation of cortical microfilaments by CPI-17, but did not reverse shrinkage in area, whereas kinase inhibitors HA1077 and H7 prevented CPI-17-induced changes in microfilament distribution and cell contraction. These results highlight the physiological importance of myosin/moesin phosphatase regulation to dynamic remodeling of the cytoskeleton.

  2. The P6 protein of Cauliflower mosaic virus interacts with CHUP1, a plant protein which moves chloroplasts on actin microfilaments.

    PubMed

    Angel, Carlos A; Lutz, Lindy; Yang, Xiaohua; Rodriguez, Andres; Adair, Adam; Zhang, Yu; Leisner, Scott M; Nelson, Richard S; Schoelz, James E

    2013-09-01

    The gene VI product, protein 6 (P6), of Cauliflower mosaic virus (CaMV) assembles into large, amorphous inclusion bodies (IBs) that are considered sites for viral protein synthesis and viral genome replication and encapsidation. P6 IBs align with microfilaments and require them for intracellular trafficking, a result implying that P6 IBs function to move virus complexes or virions within the cell to support virus physiology. Through a yeast two-hybrid screen we determined that CHUP1, a plant protein allowing chloroplast transport through an interaction with chloroplast and microfilament, interacts with P6. The interaction between CHUP1 and P6 was confirmed through colocalization in vivo and co-immunoprecipitation assays. A truncated CHUP1 fused with enhanced cyan fluorescent protein, unable to transport chloroplasts, inhibited intracellular movement of P6-Venus inclusions. Silencing of CHUP1 in N. edwardsonii impaired the ability of CaMV to infect plants. The findings suggest that CHUP1 supports CaMV infection through an interaction with P6.

  3. Glass Research

    NASA Technical Reports Server (NTRS)

    Weinberg, M. C.

    1985-01-01

    Research efforts span three general areas of glass science: glass refining, gel-derived glasses, and nucleation and crystallization of glasses. Gas bubbles which are present in a glass product are defects which may render the glass totally useless for the end application. For example, optical glasses, laser host glasses, and a variety of other specialty glasses must be prepared virtually defect free to be employable. Since a major mechanism of bubble removal, buoyant rise, is virtually inoperative in microgravity, glass fining will be especially difficult in space. On the other hand, the suppression of buoyant rise and the ability to perform containerless melting experiments in space allows the opportunity to carry out several unique bubble experiments in space. Gas bubble dissolution studies may be performed at elevated temperatures for large bubbles with negligible bubble motion. Also, bubble nucleation studies may be performed without the disturbing feature of heterogeneous bubble nucleation at the platinum walls. Ground based research efforts are being performed in support of these potential flight experiments.

  4. The Cauliflower Mosaic Virus Protein P6 Forms Motile Inclusions That Traffic along Actin Microfilaments and Stabilize Microtubules1[W][OA

    PubMed Central

    Harries, Phillip A.; Palanichelvam, Karuppaiah; Yu, Weichang; Schoelz, James E.; Nelson, Richard S.

    2009-01-01

    The gene VI product (P6) of Cauliflower mosaic virus (CaMV) is a multifunctional protein known to be a major component of cytoplasmic inclusion bodies formed during CaMV infection. Although these inclusions are known to contain virions and are thought to be sites of translation from the CaMV 35S polycistronic RNA intermediate, the precise role of these bodies in the CaMV infection cycle remains unclear. Here, we examine the functionality and intracellular location of a fusion between P6 and GFP (P6-GFP). We initially show that the ability of P6-GFP to transactivate translation is comparable to unmodified P6. Consequently, our work has direct application for the large body of literature in which P6 has been expressed ectopically and its functions characterized. We subsequently found that P6-GFP forms highly motile cytoplasmic inclusion bodies and revealed through fluorescence colocalization studies that these P6-GFP bodies associate with the actin/endoplasmic reticulum network as well as microtubules. We demonstrate that while P6-GFP inclusions traffic along microfilaments, those associated with microtubules appear stationary. Additionally, inhibitor studies reveal that the intracellular movement of P6-GFP inclusions is sensitive to the actin inhibitor, latrunculin B, which also inhibits the formation of local lesions by CaMV in Nicotiana edwardsonii leaves. The motility of P6 along microfilaments represents an entirely new property for this protein, and these results imply a role for P6 in intracellular and cell-to-cell movement of CaMV. PMID:19028879

  5. GLASS FIBER REINFORCED PLASTICS,

    DTIC Science & Technology

    Contents: Fibrous glass fillers Binders used in the glass plastic industry Method of manufacturing glass plastics and glass plastic articles Properties of fiberglass Primary areas for use of glass fibre reinforced plastics

  6. Glass corrosion in natural environments

    NASA Technical Reports Server (NTRS)

    Thorpe, Arthur N.; Barkatt, Aaron

    1992-01-01

    Experiments carried out during the progress period are summarized. Experiments carried out involving glass samples exposed to solutions of Tris have shown the appearance of 'spikes' upon monitoring glass dissolution as a function of time. The periodic 'spikes' observed in Tris-based media were interpreted in terms of cracking due to excessive stress in the surface region of the glass. Studies of the interactions of silicate glasses with metal ions in buffered media were extended to systems containing Al. Caps buffer was used to establish the pH. The procedures used are described and the results are given. Preliminary studies were initiated as to the feasibility of adding a slowly dissolving solid compound of the additive to the glass-water system to maintain a supply of dissolved additive. It appears that several magnesium compounds have a suitable combination of solubility and affinity towards silicate glass surfaces to have a pronounced retarding effect on the extraction of uranium from the glass. These preliminary findings raise the possibility that introducing a magnesium source into geologic repositories for nuclear waste glass in the form of a sparingly soluble Mg-based backfill material may cause a substantial reduction in the extent of long-term glass corrosion. The studies described also provide mechanistic understanding of the roles of various metal solutes in the leachant. Such understanding forms the basis for developing long-term predictions of nuclear waste glass durability under repository conditions. From what is known about natural highly reduced glasses such as tektites, it is clear that iron is dissolved as ferrous iron with little or no ferric iron. The reducing conditions were high enough to cause metallic iron to exsolve out of the glass in the form of submicroscopic spherules. As the nuclear waste glass is much less reduced, a study was initiated on other natural glasses in addition to the nuclear waste glass. Extensive measurements were

  7. Orientifolded locally AdS3 geometries

    NASA Astrophysics Data System (ADS)

    Loran, F.; Sheikh-Jabbari, M. M.

    2011-01-01

    Continuing the analysis of [Loran F and Sheikh-Jabbari M M 2010 Phys. Lett. B 693 184-7], we classify all locally AdS3 stationary axi-symmetric unorientable solutions to AdS3 Einstein gravity and show that they are obtained by applying certain orientifold projection on AdS3, BTZ or AdS3 self-dual orbifold, respectively, O-AdS3, O-BTZ and O-SDO geometries. Depending on the orientifold fixed surface, the O-surface, which is either a space-like 2D plane or a cylinder, or a light-like 2D plane or a cylinder, one can distinguish four distinct cases. For the space-like orientifold plane or cylinder cases, these geometries solve AdS3 Einstein equations and are hence locally AdS3 everywhere except at the O-surface, where there is a delta-function source. For the light-like cases, the geometry is a solution to Einstein equations even at the O-surface. We discuss the causal structure for static, extremal and general rotating O-BTZ and O-SDO cases as well as the geodesic motion on these geometries. We also discuss orientifolding Poincaré patch AdS3 and AdS2 geometries as a way to geodesic completion of these spaces and comment on the 2D CFT dual to the O-geometries.

  8. Tempered glass

    SciTech Connect

    Bunnell, L.R.

    1991-11-01

    This document describes a demonstration for making tempered glass using minimal equipment. The demonstration is intended for a typical student of materials science, at the high school level or above. (JL)

  9. DEVELOPMENT OF CRYSTAL-TOLERANT WASTE GLASSES

    SciTech Connect

    Matyas, Josef; Vienna, John D.; Kimura, Akihiko; Schaible, Micah J.; Tate, Rachel M.

    2010-10-26

    The loading of high-level waste in borosilicate glasses is limited by crystallinity constraints that cannot prevent crystal accumulation on the melter bottom and in the glass discharge riser of the melter. Pacific Northwest National Laboratory is studying variations in composition that are designed to constrain high-level waste glass compositions and develop the crystal-tolerant high-level waste glasses. These glasses will allow high waste loading without decreasing the lifetime of the melter by keeping the small spinel crystals suspended in the molten glass. Adding ~1 wt% of NiO to the baseline glass caused large spinel crystals to form up to 210 µm in size and resulted in the highest accumulation rate, ~ 227 mm/year, of all tested glasses. Noble metals that were added to high-Ni glass prevented large spinel crystals from forming and decreased the accumulation rate ~ 8.5 times. Adding ~5 wt% of Fe2O3 to the baseline glass resulted in a high number density of ~10-μm spinel crystals that remained suspended in the glass melt even after 17 days at 850°C. The accumulation rate of spinel crystals in high-chromia crucibles was only slightly higher compared with the accumulation rate in double crucibles. Only baseline glass exhibited about 2.6 times faster accumulation rate because of increased number of bigger crystals. These crystals were the result of glass enrichment with chromium that was leached out from the walls of high-chromia crucibles.

  10. Warped AdS3 black holes

    NASA Astrophysics Data System (ADS)

    Anninos, Dionysios; Li, Wei; Padi, Megha; Song, Wei; Strominger, Andrew

    2009-03-01

    Three dimensional topologically massive gravity (TMG) with a negative cosmological constant -l-2 and positive Newton constant G admits an AdS3 vacuum solution for any value of the graviton mass μ. These are all known to be perturbatively unstable except at the recently explored chiral point μl = 1. However we show herein that for every value of μl ≠ 3 there are two other (potentially stable) vacuum solutions given by SL(2,Bbb R) × U(1)-invariant warped AdS3 geometries, with a timelike or spacelike U(1) isometry. Critical behavior occurs at μl = 3, where the warping transitions from a stretching to a squashing, and there are a pair of warped solutions with a null U(1) isometry. For μl > 3, there are known warped black hole solutions which are asymptotic to warped AdS3. We show that these black holes are discrete quotients of warped AdS3 just as BTZ black holes are discrete quotients of ordinary AdS3. Moreover new solutions of this type, relevant to any theory with warped AdS3 solutions, are exhibited. Finally we note that the black hole thermodynamics is consistent with the hypothesis that, for μl > 3, the warped AdS3 ground state of TMG is holographically dual to a 2D boundary CFT with central charges c_R-formula and c_L-formula.

  11. Warped AdS3 black holes

    NASA Astrophysics Data System (ADS)

    Song, Wei; Anninos, Dionysios; Li, Wei; Padi, Megha; Strominger, Andrew

    2009-03-01

    Three dimensional topologically massive gravity (TMG) with a negative cosmological constant -ell-2 and positive Newton constant G admits an AdS3 vacuum solution for any value of the graviton mass μ. These are all known to be perturbatively unstable except at the recently explored chiral point μell = 1. However we show herein that for every value of μell ≠ 3 there are two other (potentially stable) vacuum solutions given by SL(2,Bbb R) × U(1)-invariant warped AdS3 geometries, with a timelike or spacelike U(1) isometry. Critical behavior occurs at μell = 3, where the warping transitions from a stretching to a squashing, and there are a pair of warped solutions with a null U(1) isometry. For μell > 3, there are known warped black hole solutions which are asymptotic to warped AdS3. We show that these black holes are discrete quotients of warped AdS3 just as BTZ black holes are discrete quotients of ordinary AdS3. Moreover new solutions of this type, relevant to any theory with warped AdS3 solutions, are exhibited. Finally we note that the black hole thermodynamics is consistent with the hypothesis that, for μell > 3, the warped AdS3 ground state of TMG is holographically dual to a 2D boundary CFT with central charges c_R-formula and c_L-formula.

  12. Modification of resin modified glass ionomer cement by addition of bioactive glass nanoparticles.

    PubMed

    Valanezhad, Alireza; Odatsu, Tetsuro; Udoh, Koichi; Shiraishi, Takanobu; Sawase, Takashi; Watanabe, Ikuya

    2016-01-01

    In the present study, sol-gel derived nanoparticle calcium silicate bioactive glass was added to the resin-modified light cure glass-ionomer cement to assess the influence of additional bioactive glass nanoparticles on the mechanical and biological properties of resin-modified glass-ionomer cement. The fabricated bioactive glass nanoparticles added resin-modified glass-ionomer cements (GICs) were immersed in the phosphate buffer solution for 28 days to mimic real condition for the mechanical properties. Resin-modified GICs containing 3, 5 and 10 % bioactive glass nanoparticles improved the flexural strength compared to the resin-modified glass-ionomer cement and the samples containing 15 and 20 % bioactive glass nanoparticles before and after immersing in the phosphate buffer solution. Characterization of the samples successfully expressed the cause of the critical condition for mechanical properties. Cell study clarified that resin-modified glass-ionomer cement with high concentrations of bioactive glass nanoparticles has higher cell viability and better cell morphology compare to control groups. The results for mechanical properties and toxicity approved that the considering in selection of an optimum condition would have been a more satisfying conclusion for this study.

  13. Segmented strings in AdS 3

    NASA Astrophysics Data System (ADS)

    Callebaut, Nele; Gubser, Steven S.; Samberg, Andreas; Toldo, Chiara

    2015-11-01

    We study segmented strings in flat space and in AdS 3. In flat space, these well known classical motions describe strings which at any instant of time are piecewise linear. In AdS 3, the worldsheet is composed of faces each of which is a region bounded by null geodesics in an AdS 2 subspace of AdS 3. The time evolution can be described by specifying the null geodesic motion of kinks in the string at which two segments are joined. The outcome of collisions of kinks on the worldsheet can be worked out essentially using considerations of causality. We study several examples of closed segmented strings in AdS 3 and find an unexpected quasi-periodic behavior. We also work out a WKB analysis of quantum states of yo-yo strings in AdS 5 and find a logarithmic term reminiscent of the logarithmic twist of string states on the leading Regge trajectory.

  14. Prediction of glass durability as a function of environmental conditions

    SciTech Connect

    Jantzen, C M

    1988-01-01

    A thermodynamic model of glass durability is applied to natural, ancient, and nuclear waste glasses. The durabilities of over 150 different natural and man-made glasses, including actual ancient Roman and Islamic glasses (Jalame ca. 350 AD, Nishapur 10-11th century AD and Gorgon 9-11th century AD), are compared. Glass durability is a function of the thermodynamic hydration free energy, ..delta..G/sub hyd/, which can be calculated from glass composition and solution pH. The durability of the most durable nuclear waste glasses examined was /approximately/10/sup 6/ years. The least durable waste glass formulations were comparable in durability to the most durable simulated medieval window glasses of /approximately/10/sup 3/ years. In this manner, the durability of nuclear waste glasses has been interpolated to be /approximately/10/sup 6/ years and no less than 10/sup 3/ years. Hydration thermodynamics have been shown to be applicable to the dissolution of glass in various natural environments. Groundwater-glass interactions relative to geologic disposal of nuclear waste, hydration rind dating of obsidians, andor other archeological studies can be modeled, e.g., the relative durabilities of six simulated medieval window glasses have been correctly predicted for both laboratory (one month) and burial (5 years) experiments. Effects of solution pH on glass dissolution has been determined experimentally for the 150 different glasses and can be predicted theoretically by hydration thermodynamics. The effects of solution redox on dissolution of glass matrix elements such as SI and B have shown to be minimal. The combined effects of solution pH and Eh have been described and unified by construction of thermodynamically calculated Pourbaix (pH-Eh) diagrams for glass dissolution. The Pourbaix diagrams have been quantified to describe glass dissolution as a function of environmental conditions by use of the data derived from hydration thermodynamics. 56 refs., 7 figs.

  15. Pinhole Glasses

    ERIC Educational Resources Information Center

    Colicchia, Giuseppe; Hopf, Martin; Wiesner, Hartmut; Zollman, Dean

    2008-01-01

    Eye aberrations are commonly corrected by lenses that restore vision by altering rays before they pass through the cornea. Some modern promoters claim that pinhole glasses are better than conventional lenses in correcting all kinds of refractive defects such as myopia (nearsighted), hyperopia (farsighted), astigmatisms, and presbyopia. Do pinhole…

  16. Raman and Infrared Spectroscopy of Yttrium Aluminum Borate Glasses and Glass-ceramics

    NASA Technical Reports Server (NTRS)

    Bradley, J.; Brooks, M.; Crenshaw, T.; Morris, A.; Chattopadhyay, K.; Morgan, S.

    1998-01-01

    Raman spectra of glasses and glass-ceramics in the Y2O3-Al2O3-B2O3 system are reported. Glasses with B2O3 contents ranging from 40 to 60 mole percent were prepared by melting 20 g of the appropriate oxide or carbonate powders in alumina crucibles at 1400 C for 45 minutes. Subsequent heat treatments of the glasses at temperatures ranging from 600 to 800 C were performed in order to induce nucleation and crystallization. It was found that Na2CO3 added to the melt served as a nucleating agent and resulted in uniform bulk crystallization. The Raman spectra of the glasses are interpreted primarily in terms of vibrations of boron - oxygen structural groups. Comparison of the Raman spectra of the glass-ceramic samples with spectra of aluminate and borate crystalline materials reveal that these glasses crystallize primarily as yttrium aluminum borate, YAl3(BO3)4.

  17. Reinforcement of conventional glass-ionomer restorative material with short glass fibers.

    PubMed

    Hammouda, Ibrahim M

    2009-01-01

    This study investigated the strengthening effect of glass fibers when added to conventional glass-ionomer restorative material. Glass fibers were incorporated into glass-ionomer powder in 3 wt% and 5 wt%. The fibers used had 1 mm length and 10 microm thickness. These criteria of fiber length, diameter, and concentration represent a new approach for reinforcing conventional glass-ionomer [Medifill, conventional restorative glass-ionomer]. The mechanical properties tested were diametral tensile strength, hardness, flexural strength, flexural modulus and fracture toughness after 24-h and 7-days of storage in deionized water. Glass short fibers were mixed thoroughly into the glass-ionomer powder before mixing with the cement liquid. Samples of specific dimensions were prepared for each time interval and fiber loading according to the manufacturer's instructions and international standards. Hardness was measured using a micro-hardness tester at 100 gram applied load for 15 s. The other mechanical properties were measured using a Lloyd universal testing machine. The results showed increased diametral tensile strength, flexural strength, flexural modulus, and fracture toughness by the addition of glass fibers. There was an appreciable increase of the tested mechanical properties of glass-ionomer restorative material as a result of increasing fiber loading and water storage for 1 week. It was concluded that conventional glass-ionomer can be reinforced by the addition of short glass fibers.

  18. Electrochromic Glasses.

    DTIC Science & Technology

    1980-07-31

    Li20-B203 and Na20-B203 or Te02 . These glasses exhibit for the first time, electrochromic and photochromic behaviour and have potential for use in...the complete spectral distribution of the absorption at levels of 10- cm- I for the first time. In the past, it was only possible to measure low...distribution of the absorption at levels at 10 -cm it was possible, for the first time, to identify extrinsic impurities in highly transparent solids. This

  19. AdS duals of matrix strings

    NASA Astrophysics Data System (ADS)

    Morales, Jose F.; Samtleben, Henning

    2003-06-01

    We review recent work on the holographic duals of type II and heterotic matrix string theories described by warped AdS3 supergravities. In particular, we compute the spectra of Kaluza-Klein primaries for type I, II supergravities on warped AdS3 × S7 and match them with the primary operators in the dual two-dimensional gauge theories. The presence of non-trivial warp factors and dilaton profiles requires a modification of the familiar dictionary between masses and 'scaling' dimensions of fields and operators. We present these modifications for the general case of domain wall/QFT correspondences between supergravities on warped AdSd+1 × Sq geometries and super Yang-Mills theories with 16 supercharges.

  20. Actin microfilaments participate in the regulation of the COL1A1 promoter activity in ROS17/2.8 cells under simulated microgravity

    NASA Astrophysics Data System (ADS)

    Dai, Zhongquan; Li, Yinghui; Ding, Bai; Zhang, Xiaoyou; Tan, Yingjun; Wan, Yumin

    2006-01-01

    IntroductionMicrogravity is thought to decrease osteoblastic activity and induce osteoporosis during spaceflight, but the mechanisms, particularly the attendant changes in gene expression, are not well understood. It is suspected that the cytoskeletal system is involved in the manifold changes of cell shape, function, and signaling under microgravity conditions. MethodsWe constructed cell lines stably transfected with pJI36EGFP and pJI23EGFP, which contained a 3.6 and a 2.3 kb fragment, respectively, of the α1(I) collagen gene (COL1A1) promoter fused with the enhanced green fluorescence protein (EGFP) reporter gene. We then developed a semi-quantitative analysis of EGFP fluorescence intensity to evaluate the effects of clinorotation and/or cytochalasin B on the activity of the COL1A1 promoter. Simultaneously, we assessed the collagen type I protein content versus total protein content in clinorotated or control osteoblasts, using immunocytochemistry and the Bradford method, respectively. ResultsThe fluorescence intensity analysis revealed that the expression of COL1A1-EGFP increased in GFP-ROS cells clinorotated for 24 or 48 h, as compared with stationary control cultures. We observed a similar trend in collagen type I content, as assessed by immunocytochemistry. We found that the osteoblast microfilaments tended to disassemble and show a reduction in stress fibers under space flight and clinorotation. Treatment with cytochalasin B in normal gravity resulted in a dose-dependent increase of EGFP fluorescence intensity, indicating that disruption of the actin system was associated with increased activity of the COL1A1 promoter. ConclusionOur study demonstrates that disrupting the actin cytoskeleton by treatment with cytochalasin B and real or simulated microgravity conditions led to altered COL1A1 promoter activity. Together, these results suggest that actin may participate in the regulation of the COL1A1 promoter activity under microgravity conditions.

  1. [Characteristics of chemical composition of glass finds from the Qiemo tomb sites on the Silk Road].

    PubMed

    Cheng, Qian; Guo, Jin-Long; Wang, Bo; Cui, Jian-Feng

    2012-07-01

    Qiemo was an ancient country on the south branch of the Silk Road. The Zagunluke tomb site is located at the Qiemo County of the Xinjiang Uygur Autonomous Region. Glass beads and only colourless glass cup were excavated from the 3rd cultural layer of the tomb site M133 and M49, dated between the 1st AD-6th AD. LA-ICP-AES was applied to analyse chemical composition of these glass finds with the corning glass as reference. According to the result, characteristics of chemical composition are very similar to typical soda-lime glass, which indicates the glasses were imported productions from the west. These soda-lime glasses were divided into two groups in terms of flux source: natron glass and plant ash glass. This analytical research indicates the history of glass trade and communication between the East and the West on the Silk Road.

  2. Adsorption of monoclonal antibodies to glass microparticles.

    PubMed

    Hoehne, Matthew; Samuel, Fauna; Dong, Aichun; Wurth, Christine; Mahler, Hanns-Christian; Carpenter, John F; Randolph, Theodore W

    2011-01-01

    Microparticulate glass represents a potential contamination to protein formulations that may occur as a result of processing conditions or glass types. The effect of added microparticulate glass to formulations of three humanized antibodies was tested. Under the three formulation conditions tested, all three antibodies adsorbed irreversibly at near monolayer surface coverages to the glass microparticles. Analysis of the secondary structure of the adsorbed antibodies by infrared spectroscopy reveal only minor perturbations as a result of adsorption. Likewise, front-face fluorescence quenching measurements reflected minimal tertiary structural changes upon adsorption. In contrast to the minimal effects on protein structure, adsorption of protein to suspensions of glass microparticles induced significant colloidal destabilization and flocculation of the suspension.

  3. GlassForm

    SciTech Connect

    2011-09-16

    GlassForm is a software tool for generating preliminary waste glass formulas for a given waste stream. The software is useful because it reduces the number of verification melts required to develop a suitable additive composition. The software includes property models that calculate glass properties of interest from the chemical composition of the waste glass. The software includes property models for glass viscosity, electrical conductivity, glass transition temperature, and leach resistance as measured by the 7-day product consistency test (PCT).

  4. Strength of inorganic glass

    SciTech Connect

    Kurkjian, C.R.

    1985-01-01

    This book presents information on the following topics: a look at the history of glass strength; atomistic theory of fracture; surface chemistry in relation to the strength and fracture of silicate glasses; high-speed photographic investigations of the dynamic localized loading of some oxide glasses; a correction for measurements of contact area using Newton's rings; envionmentally enhanced crack growth; fatigue in glass; behavior of flaws in fused silica fibers; fracture toughness of chalcogenide glasses and glass-ceramics; fracture analysis of glass surfaces; and fracture mechanics parameters for glasses - a compilation and correlation.

  5. CRYSTALLIZATION IN MULTICOMPONENT GLASSES

    SciTech Connect

    KRUGER AA; HRMA PR

    2009-10-08

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

  6. IMPACT STRENGTH OF GLASS AND GLASS CERAMIC

    SciTech Connect

    Bless, S.; Tolman, J.

    2009-12-28

    Strength of glass and glass ceramic was measured with a bar impact technique. High-speed movies show regions of tensile and compressive failure. The borosilicate glass had a compressive strength of at least 2.2 GPa, and the glass ceramic at least 4 GPa. However, the BSG was much stronger in tension than GC. In ballistic tests, the BSG was the superior armor.

  7. An AdS Crunch in Supergravity

    NASA Astrophysics Data System (ADS)

    Hertog, Thomas

    2004-12-01

    We review some properties of N=8 gauged supergravity in four dimensions with modified, but AdS invariant boundary conditions on the m2 = -2 scalars. There is a one-parameter class of asymptotic conditions on these fields and the metric components, for which the full AdS symmetry group is preserved. The generators of the asymptotic symmetries are finite, but acquire a contribution from the scalar fields. For a large class of such boundary conditions, we find there exist black holes with scalar hair that are specified by a single conserved charge. Since Schwarschild-AdS is a solution too for all boundary conditions, this provides an example of black hole non-uniqueness. We also show there exist solutions where smooth initial data evolve to a big crunch singularity. This opens up the possibility of using the dual conformal field theory to obtain a fully quantum description of the cosmological singularity, and we report on a preliminary study of this.

  8. Enhancement effect of pre-reacted glass on strength of glass-ionomer cement.

    PubMed

    Monmaturapoj, Naruporn; Soodsawang, Wiwaporn; Tanodekaew, Siriporn

    2012-02-03

    In this paper, we report on the enhanced strength of glass ionomer cement (GIC) by using the process of pre acid-base reaction and spray drying in glass preparation. The pre acid-base reaction was induced by prior mixing of the glass powder with poly(alkenoic acid). The weight ratios of glass powder to poly(alkenoic acid) were varied to investigate the extent of the pre acid-base reaction of the glass. The effect of the spray drying process which produced spherical glass particles on cement strength was also studied and discussed. The results show that adding 2%-wt of poly(alkenoic acid) liquid in the pre-reacted step improved cement strength. GICs prepared using a mixture of pre-reacted glass with both spherical and irregular powders at 60:40 by weight exhibited the highest compressive strength at 138.64±7.73 MPa. It was concluded that glass ionomer cements containing pre-reacted glass with mixed glass morphology using both spherical and irregular forms are promising as restorative dental materials with improved mechanical properties and handling characteristics.

  9. Chemical Principles Revisited: The Chemistry of Glass.

    ERIC Educational Resources Information Center

    Kolb, Doris; Kolb, Kenneth E.

    1979-01-01

    Presents a detailed discussion on the chemistry of glass. Topics discussed include: natural glass, early history, modern glass composition, raw materials for glass melting, chemically modified glasses, modern glass forming, glass ceramics, and new developments in glass research. (BT)

  10. Inverted glass harp

    NASA Astrophysics Data System (ADS)

    Quinn, Daniel B.; Rosenberg, Brian J.

    2015-08-01

    We present an analytical treatment of the acoustics of liquid-filled wine glasses, or "glass harps." The solution is generalized such that under certain assumptions it reduces to previous glass harp models, but also leads to a proposed musical instrument, the "inverted glass harp," in which an empty glass is submerged in a liquid-filled basin. The versatility of the solution demonstrates that all glass harps are governed by a family of solutions to Laplace's equation around a vibrating disk. Tonal analyses of recordings for a sample glass are offered as confirmation of the scaling predictions.

  11. Glass-silicon column

    DOEpatents

    Yu, Conrad M.

    2003-12-30

    A glass-silicon column that can operate in temperature variations between room temperature and about 450.degree. C. The glass-silicon column includes large area glass, such as a thin Corning 7740 boron-silicate glass bonded to a silicon wafer, with an electrode embedded in or mounted on glass of the column, and with a self alignment silicon post/glass hole structure. The glass/silicon components are bonded, for example be anodic bonding. In one embodiment, the column includes two outer layers of silicon each bonded to an inner layer of glass, with an electrode imbedded between the layers of glass, and with at least one self alignment hole and post arrangement. The electrode functions as a column heater, and one glass/silicon component is provided with a number of flow channels adjacent the bonded surfaces.

  12. Glass fiber addition strengthens low-density ablative compositions

    NASA Technical Reports Server (NTRS)

    Chandler, H. H.

    1974-01-01

    Approximately 15% of E-glass fibers was added to compositions under test and greatly improved char stability. Use of these fibers also reduced thermal strains which, in turn, minimized char shrinkage and associated cracks, subsurface voids, and disbonds. Increased strength allows honeycomb core reinforcement to be replaced by equivalent amount of glass fibers.

  13. AdS3: the NHEK generation

    NASA Astrophysics Data System (ADS)

    Bena, Iosif; Heurtier, Lucien; Puhm, Andrea

    2016-05-01

    It was argued in [1] that the five-dimensional near-horizon extremal Kerr (NHEK) geometry can be embedded in String Theory as the infrared region of an infinite family of non-supersymmetric geometries that have D1, D5, momentum and KK monopole charges. We show that there exists a method to embed these geometries into asymptotically- {AdS}_3× {S}^3/{{Z}}_N solutions, and hence to obtain infinite families of flows whose infrared is NHEK. This indicates that the CFT dual to the NHEK geometry is the IR fixed point of a Renormalization Group flow from a known local UV CFT and opens the door to its explicit construction.

  14. AdS2 holographic dictionary

    NASA Astrophysics Data System (ADS)

    Cvetič, Mirjam; Papadimitriou, Ioannis

    2016-12-01

    We construct the holographic dictionary for both running and constant dilaton solutions of the two dimensional Einstein-Maxwell-Dilaton theory that is obtained by a circle reduction from Einstein-Hilbert gravity with negative cosmological constant in three dimensions. This specific model ensures that the dual theory has a well defined ultraviolet completion in terms of a two dimensional conformal field theory, but our results apply qualitatively to a wider class of two dimensional dilaton gravity theories. For each type of solutions we perform holographic renormalization, compute the exact renormalized one-point functions in the presence of arbitrary sources, and derive the asymptotic symmetries and the corresponding conserved charges. In both cases we find that the scalar operator dual to the dilaton plays a crucial role in the description of the dynamics. Its source gives rise to a matter conformal anomaly for the running dilaton solutions, while its expectation value is the only non trivial observable for constant dilaton solutions. The role of this operator has been largely overlooked in the literature. We further show that the only non trivial conserved charges for running dilaton solutions are the mass and the electric charge, while for constant dilaton solutions only the electric charge is non zero. However, by uplifting the solutions to three dimensions we show that constant dilaton solutions can support non trivial extended symmetry algebras, including the one found by Compère, Song and Strominger [1], in agreement with the results of Castro and Song [2]. Finally, we demonstrate that any solution of this specific dilaton gravity model can be uplifted to a family of asymptotically AdS2 × S 2 or conformally AdS2 × S 2 solutions of the STU model in four dimensions, including non extremal black holes. The four dimensional solutions obtained by uplifting the running dilaton solutions coincide with the so called `subtracted geometries', while those obtained

  15. Lead recovery and high silica glass powder synthesis from waste CRT funnel glasses through carbon thermal reduction enhanced glass phase separation process.

    PubMed

    Xing, Mingfei; Fu, Zegang; Wang, Yaping; Wang, Jingyu; Zhang, Zhiyuan

    2017-01-15

    In this study, a novel process for the removal of toxic lead from the CRT funnel glass and synchronous preparation of high silica glass powder was developed by a carbon-thermal reduction enhanced glass phase separation process. CRT funnel glass was remelted with B2O3 in reducing atmosphere. In the thermal process, a part of PbO contained in the funnel glass was reduced into metallic Pb and detached from the glass phase. The rest of PbO and other metal oxides (including Na2O, K2O, Al2O3, BaO and CaO) were mainly concentrated in the boric oxide phase. The metallic Pb phase and boric oxide phase were completely leached out by 5mol/L HNO3. The lead removal rate was 99.80% and high silica glass powder (SiO2 purity >95wt%) was obtained by setting the temperature, B2O3 added amount and holding time at 1000°C, 20% and 30mins, respectively. The prepared high silicate glass powders can be used as catalyst carrier, semipermeable membranes, adsorbents or be remelted into high silicate glass as an ideal substitute for quartz glass. Thus this study proposed an eco-friendly and economical process for recycling Pb-rich electronic glass waste.

  16. Chalcogenide-mold interactions during precision glass molding (PGM) of GeAsSe glasses

    NASA Astrophysics Data System (ADS)

    Gleason, B.; Wachtel, P.; Musgraves, J. D.; Steinkopf, R.; Eberhardt, R.; Richardson, K.

    2013-09-01

    Five chalcogenide glasses in the GeAsSe ternary glass system were melted, fabricated into flats, and molded between planar, uncoated, binderless WC molds using a laboratory-scale precision glass molding machine. The five glasses originate at the binary arsenic triselenide (As40Se60) and are modified by replacing As with Se in 5 mol% increments, or by locking the As:Se ratio and adding Ge, also in 5 mol% increments. The glasses are separated into two groups, one for the Ge-free compositions and the other for the Ge-containing compositions. This effort analyzes the differences between the Ge-containing and the Ge-free glasses on the post-molded glass and mold surface behavior, as well as the mold lifetime. Fabrication features, such as scratch and/or dig marks were present on the glass and mold surfaces prior to the PGM process. White light interferometry analysis of the surfaces shows an overall reduction in the RMS roughness of the glass after molding, and an increase of the roughness of the molds, after 15 molding cycles. After molding, the quantity of observable defects, primarily deposits and dig marks are increased for both the glass and mold surfaces. Deposits found on the WC molds and glasses were analyzed using Electron Dispersive X-ray Spectroscopy (EDS) and showed no evidence of being due to material transfer between the WC molds and the glass constituents. In general the main observable difference in the analysis of the two post molded sets, despite the changes in chemistry, is the quantity of molding induced defects near the edge of the GeAsSe samples.

  17. Picture Wall (Glass Structures)

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Photo shows a subway station in Toronto, Ontario, which is entirely glass-enclosed. The all-glass structure was made possible by a unique glazing concept developed by PPG Industries, Pittsburgh, Pennsylvania, one of the largest U.S. manufacturers of flat glass. In the TVS glazing system, transparent glass "fins" replace conventional vertical support members used to provide support for wind load resistance. For stiffening, silicone sealant bonds the fins to adjacent glass panels. At its glass research center near Pittsburgh, PPG Industries uses the NASTRAN computer program to analyze the stability of enclosures made entirely of glass. The company also uses NASTRAN to simulate stresses on large containers of molten glass and to analyze stress effects of solar heating on flat glass.

  18. Glasses in the D'Orbigny angrite

    NASA Astrophysics Data System (ADS)

    Varela, Maria Eugenia; Kurat, Gero; Zinner, Ernst; Métrich, Nicole; Brandstätter, Franz; Ntaflos, Theodoros; Sylvester, Paul

    2003-12-01

    The angrites are a small and heterogeneous group of achondritic meteorites with highly unusual chemical and mineralogical features. The abundant presence of glasses in D'Orbigny makes this rock a unique member of the angrite group. Glasses fill open spaces, form pockets, and occur as inclusions in olivines. Their physical settings exclude an incorporation from an external source. Major and trace element (rare earth elements [REE], Li, B, Be, transition elements, N and C) contents of these glasses and host olivines were measured combining laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), secondary-ion mass spectrometry (SIMS), Nuclear Reaction Analysis (NRA), and EMP techniques. Based on the major element composition, glasses filling voids could represent either a melt formed by melting an angritic rock or a melt from which angrites could have crystallized. Trace element contents of these glasses strongly indicate a direct link to the D'Orbigny bulk meteorite. They are incompatible with the formation of the glasses by partial melting of a chondritic source rock or by shock melting. The refractory elements (e.g., Al, Ti, Ca) have about 10 × CI abundances with CaO/TiO 2 and FeO/MnO ratios being approximately chondritic. Trace element abundances in the glasses appear to be governed by volatility and suggest that the refractory elements in the source had chondritic relative abundances. Although the glasses (and the whole rock) lack volatile elements such as Na and K, they are rich in some moderately volatile elements such as B, V, Mn, Fe (all with close to CI abundances), and Li (about 3-5 × CI). These elements likely were added to the glass in a sub-solidus metasomatic elemental exchange event. We have identified a novel mechanism for alteration of glass and rock compositions based on an exchange of Al and Sc for Fe and other moderately volatile elements in addition to the well-known metasomatic exchange reactions (e.g., Ca-Na and Mg

  19. Bioactive glasses and glass-ceramics.

    PubMed

    Rawlings, R D

    1993-01-01

    Bioactive materials are designed to induce a specific biological activity; in most cases the desired biological activity is one that will give strong bonding to bone. A range of materials has been assessed as being capable of bonding to bone, but this paper is solely concerned with bioactive glasses and glass-ceramics. Firstly, the structure and processing of glasses and glass-ceramics are described, as a basic knowledge is essential for the understanding of the development and properties of the bioactive materials. The effect of composition and structure on the bioactivity is then discussed, and it will be shown that bioactivity is associated with the formation of an apatite layer on the surface of the implant. A survey of mechanical performance demonstrates that the structure and mechanical properties of glass-ceramics depend upon whether the processing involves casting or sintering and that the strength and toughness of glass-ceramics are superior to those of glasses. Attempts to further improve the mechanical performance by the use of non-monolithic components, i.e. bioactive coatings on metal substrates and glass and glass-ceramic matrix composites, are also reviewed and are shown to have varying degrees of success. Finally, some miscellaneous applications, namely bioactive bone cements and bone fillers, are briefly covered.

  20. Reaction cured glass and glass coatings

    NASA Technical Reports Server (NTRS)

    Goldstein, H. E.; Leiser, D. B.; Katvala, V. W. (Inventor)

    1978-01-01

    The invention relates to reaction cured glass and glass coatings prepared by reacting a compound selected from the group consisting of silicon tetraboride, silicon hexaboride, other boron silicides, boron and mixtures with a reactive glass frit composed of a porous high silica borosilicate glass and boron oxide. The glassy composites of the present invention are useful as coatings on low density fibrous porous silica insulations used as heat shields and for articles such as reaction vessels that are subjected to high temperatures with rapid heating and cooling and that require resistance to temperature and repeated thermal shock at temperatures up to about 1482C (2700PF).

  1. Structure and Properties of Rare Earth Aluminosilicate Glasses.

    NASA Astrophysics Data System (ADS)

    Kohli, Jeffrey Todd

    1991-02-01

    Rare earth aluminosilicate (REAS) glasses have been formed using conventional melting techniques. The glass-forming regions of six different ternary systems have been defined with praseodymium, neodymium, samarium, terbium, erbium, or ytterbium oxides, with alumina and silica. The glass-forming regions systematically decreased in size as the atomic number of the particular rare earth in the ternary systems increased. Glasses, of the molar composition 2R_2O_3 -2Al_2O_3 -6SiO_2, were formed with twelve of the fourteen true rare earth oxides in order to investigate further effects related to the identity of the rare earth ion in the glasses. Several properties of the rare earth aluminosilicate glasses were measured. These properties include: thermal expansion, glass transformation temperature, dilatometric softening point, density, molar volume, index of refraction, Vicker's hardness, magnetic susceptibility and the Faraday rotatory response. The structures of rare earth aluminosilicate glasses were investigated using infrared and Raman spectroscopies as well as magic angle spinning nuclear magnetic resonance (MAS-NMR). MAS-NMR provided information regarding the local environments of silicon and aluminum ions in yttrium aluminosilicate (YAS) glasses. Since the size and valence of the yttrium ion are similar to the true rare earth ions, and the properties of the REAS and YAS glasses are similar, it is believed that the structures of yttrium aluminosilicate glasses are similar to those of the true rare earth aluminosilicate glasses. Several rare earth aluminogermanate glasses, having the molar formula 2R_2O _3-2Al_2O _3-6GeO_2, were also formed using conventional melting techniques. The properties of these glasses were compared and contrasted with those of the REAS glasses. Finally, a chapter on the study of magnetic susceptibility in common insulator glasses was added to the thesis. Several techniques used to measure magnetic susceptibility are reviewed in this chapter

  2. 6. Looking glass aircraft in the project looking glass historic ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. Looking glass aircraft in the project looking glass historic district. View to north. - Offutt Air Force Base, Looking Glass Airborne Command Post, Looking Glass Avenue between Comstat Drive & Nightwatch Avenue, Offutt Air Force Base, Bellevue, Sarpy County, NE

  3. Oxynitride glass fibers

    NASA Technical Reports Server (NTRS)

    Patel, Parimal J.; Messier, Donald R.; Rich, R. E.

    1991-01-01

    Research at the Army Materials Technology Laboratory (AMTL) and elsewhere has shown that many glass properties including elastic modulus, hardness, and corrosion resistance are improved markedly by the substitution of nitrogen for oxygen in the glass structure. Oxynitride glasses, therefore, offer exciting opportunities for making high modulus, high strength fibers. Processes for making oxynitride glasses and fibers of glass compositions similar to commercial oxide glasses, but with considerable enhanced properties, are discussed. We have made glasses with elastic moduli as high as 140 GPa and fibers with moduli of 120 GPa and tensile strengths up to 2900 MPa. AMTL holds a U.S. patent on oxynitride glass fibers, and this presentation discusses a unique process for drawing small diameter oxynitride glass fibers at high drawing rates. Fibers are drawn through a nozzle from molten glass in a molybdenum crucible at 1550 C. The crucible is situated in a furnace chamber in flowing nitrogen, and the fiber is wound in air outside of the chamber, making the process straightforward and commercially feasible. Strengths were considerably improved by improving glass quality to minimize internal defects. Though the fiber strengths were comparable with oxide fibers, work is currently in progress to further improve the elastic modulus and strength of fibers. The high elastic modulus of oxynitride glasses indicate their potential for making fibers with tensile strengths surpassing any oxide glass fibers, and we hope to realize that potential in the near future.

  4. Economic manufacturing of bulk metallic glass compositions by microalloying

    DOEpatents

    Liu, Chain T.

    2003-05-13

    A method of making a bulk metallic glass composition includes the steps of:a. providing a starting material suitable for making a bulk metallic glass composition, for example, BAM-11; b. adding at least one impurity-mitigating dopant, for example, Pb, Si, B, Sn, P, to the starting material to form a doped starting material; and c. converting the doped starting material to a bulk metallic glass composition so that the impurity-mitigating dopant reacts with impurities in the starting material to neutralize deleterious effects of the impurities on the formation of the bulk metallic glass composition.

  5. Glass tube splitting tool

    NASA Technical Reports Server (NTRS)

    Klein, J. A.; Murray, C. D.; Stein, J. A.

    1971-01-01

    Tool accurately splits glass tubing so cuts are aligned 180 deg apart and reassembled tube forms low pressure, gastight enclosure. Device should interest industries using cylindrical closed glass containers.

  6. Failure in glass

    NASA Technical Reports Server (NTRS)

    Keeton, S. C.

    1972-01-01

    Review of state of the art concerning glass failure mechanisms and fatigue theories discusses brittle fracture in glass, fatigue mechanisms, fatigue behavior, environmental effects on failure rate, and aging.

  7. AD(H)D.

    PubMed

    Harrison, Christopher; Charles, Janice; Britt, Helena

    2008-06-01

    The BEACH program (Bettering the Evaluation and Care of Health) shows that management of attention deficit (hyperactivity) disorder (AD(H)D) was rare in general practice, occurring only six times per 1,000 encounters with children aged 5-17 years, between April 2000 and December 2007. This suggests that general practitioners manage AD(H)D about 46,000 times for this age group nationally each year.

  8. ADS pilot program Plan

    NASA Technical Reports Server (NTRS)

    Clauson, J.; Heuser, J.

    1981-01-01

    The Applications Data Service (ADS) is a system based on an electronic data communications network which will permit scientists to share the data stored in data bases at universities and at government and private installations. It is designed to allow users to readily locate and access high quality, timely data from multiple sources. The ADS Pilot program objectives and the current plans for accomplishing those objectives are described.

  9. Glass powder blended cement hydration modelling

    NASA Astrophysics Data System (ADS)

    Saeed, Huda

    The use of waste materials in construction is among the most attractive options to consume these materials without affecting the environment. Glass is among these types of potential waste materials. In this research, waste glass in powder form, i.e. glass powder (GP) is examined for potential use in enhancing the characteristics of concrete on the basis that it is a pozzolanic material. The experimental and the theoretical components of the work are carried out primarily to prove that glass powder belongs to the "family" of the pozzolanic materials. The chemical and physical properties of the hydrated activated glass powder and the hydrated glass powder cement on the microstructure level have been studied experimentally and theoretically. The work presented in this thesis consists of two main phases. The first phase contains experimental investigations of the reaction of glass powder with calcium hydroxide (CH) and water. In addition, it includes experiments that are aimed at determining the consumption of water and CH with time. The reactivity, degree of hydration, and nature of the pore solution of the glass powder-blended cement pastes and the effect of adding different ratios of glass powder on cement hydration is also investigated. The experiments proved that glass powder has a pozzolanic effect on cement hydration; hence it enhances the chemical and physical properties of cement paste. Based on the experimental test results, it is recommended to use a glass powder-to-cement ratio (GP/C) of 10% as an optimum ratio to achieve the best hydration and best properties of the paste. Two different chemical formulas for the produced GP C-S-H gel due to the pure GP and GP-CH pozzolanic reaction hydration are proposed. For the pure GP hydration, the produced GP C-S-H gel has a calcium-to-silica ratio (C/S) of 0.164, water-to-silica ratio (H/S) of 1.3 and sodium/silica ratio (N/S) of 0.18. However, for the GP-CH hydration, the produced GP C-S-H gel has a C/S ratio of 1

  10. Weakly supervised glasses removal

    NASA Astrophysics Data System (ADS)

    Wang, Zhicheng; Zhou, Yisu; Wen, Lijie

    2015-03-01

    Glasses removal is an important task on face recognition, in this paper, we provide a weakly supervised method to remove eyeglasses from an input face image automatically. We choose sparse coding as face reconstruction method, and optical flow to find exact shape of glasses. We combine the two processes iteratively to remove glasses more accurately. The experimental results reveal that our method works much better than these algorithms alone, and it can remove various glasses to obtain natural looking glassless facial images.

  11. Evaluation of Glass Fiber Reinforced Concrete Panels for Use in Military Construction.

    DTIC Science & Technology

    1984-06-01

    AD-A158 134 UNCLASSIFIED EVALUATION OF GLASS FIBER REINFORCED CONCRETE PANELS FOR USE IN MILITARY. . (U) CONSTRUCTION ENGINEERING RESEARCH LAB...Construction Engineering Research Laboratory i=h-C=iU. TECHNICAL REPORT M-85/15 June 1985 AD-A158 134 0~- 8 Evaluation of Glass Fiber ...Reinforced Concrete Panels for Use in Military Construction by Gilbert R. Williamson Glass fiber reinforced concrete (GFRC) materials are investigated

  12. Technique for Machining Glass

    NASA Technical Reports Server (NTRS)

    Rice, S. H.

    1982-01-01

    Process for machining glass with conventional carbide tools requires a small quantity of a lubricant for aluminum applied to area of glass to be machined. A carbide tool is then placed against workpiece with light pressure. Tool is raised periodically to clear work of glass dust and particles. Additional lubricant is applied as it is displaced.

  13. Glass in Class

    ERIC Educational Resources Information Center

    Greaves, Neville

    2005-01-01

    Glass is reviewed from fabrication to application, laying emphasis on the wide-ranging physics involved. This begins with liquids and solids and the way in which glasses are defined and can be demonstrated in the classroom. At the atomic level the regular structure of crystals and their irregular counterparts in glasses are explained through…

  14. Making MgO/SiO2 Glasses By The Sol-Gel Process

    NASA Technical Reports Server (NTRS)

    Bansal, Narottam P.

    1989-01-01

    Silicon dioxide glasses containing 15 mole percent magnesium oxide prepared by sol-gel process. Not made by conventional melting because ingredients immiscible liquids. Synthesis of MgO/SiO2 glass starts with mixing of magnesium nitrate hexahydrate with silicon tetraethoxide, both in alcohol. Water added, and transparent gel forms. Subsequent processing converts gel into glass. Besides producing glasses of new composition at lower processing temperatures, sol-gel method leads to improved homogeneity and higher purity.

  15. Radiation coloration resistant glass

    DOEpatents

    Tomozawa, M.; Watson, E.B.; Acocella, J.

    1986-11-04

    A radiation coloration resistant glass is disclosed which is used in a radiation environment sufficient to cause coloration in most forms of glass. The coloration resistant glass includes higher proportions by weight of water and has been found to be extremely resistant to color change when exposed to such radiation levels. The coloration resistant glass is free of cerium oxide and has more than about 0.5% by weight water content. Even when exposed to gamma radiation of more than 10[sup 7] rad, the coloration resistant glass does not lose transparency. 3 figs.

  16. Radiation coloration resistant glass

    DOEpatents

    Tomozawa, Minoru; Watson, E. Bruce; Acocella, John

    1986-01-01

    A radiation coloration resistant glass is disclosed which is used in a radiation environment sufficient to cause coloration in most forms of glass. The coloration resistant glass includes higher proportions by weight of water and has been found to be extremely resistant to color change when exposed to such radiation levels. The coloration resistant glass is free of cerium oxide and has more than about 0.5% by weight water content. Even when exposed to gamma radiation of more than 10.sup.7 rad, the coloration resistant glass does not lose transparency.

  17. Oxynitride glass production procedure

    DOEpatents

    Weidner, Jerry R.; Schuetz, Stanley T.; O'Brien, Michael H.

    1991-01-01

    The invention is a process for the preparation of high quality oxynitride glasses without resorting to high pressures. Nitrogen-containing compounds such as Si.sub.3 N.sub.4 are first encapsulated in a low melting temperature glass. Particles of the encapsulated nitrogen-containing compound are mixed with other oxide glass-formers and melted in an atmosphere of flowing nitrogen and in the presence of buffering gas to form the oxynitride glass. Glasses containing up to 15 at % nitrogen have been prepared by this method.

  18. Acoustics of glass harmonicas

    NASA Astrophysics Data System (ADS)

    Rossing, Thomas D.

    2004-05-01

    Glass musical instruments are probably as old as glassmaking. At least as early as the 17th century it was discovered that wine glasses, when rubbed with a wet finger, produced a musical tone. A collection of glasses played in this manner is called a glass harp. Another type of glass harmonica, called the armonica by its inventor Benjamin Franklin, employs glass bowls or cups turned by a horizontal axle, so the performer need only touch the rim of the bowls as they rotate to set them into vibration. We discuss the modes of vibration of both types of glass harmonica, and describe the different sounds that are emitted by rubbing, tapping, or bowing them. Rubbing with a wet finger tends to excite only the (2,0) mode and its harmonics through a ``stick-slip'' process, while tapping excites the other modes as well.

  19. Mechanical evaluation of SiC particle reinforced oxynitride glass and glass-ceramic composites

    SciTech Connect

    Rouxel, T.; Lavelle, C. . Lab. de Materiaux Ceramiques et Traitements de Surface); Garnier, C.; Verdier, P.; Laurent, Y. . Lab. de Chimie des Materiaux)

    1994-07-01

    In silicon oxynitride glasses, the nitrogen occupies anion sites and is bonded to three silicons. Hence, replacement of divalent oxygen ions by trivalent nitrogen ones results in a considerable improvement of the mechanical resistance. In this exploratory work, the authors investigate some basic mechanical properties at room temperature of composite materials prepared by adding some SiC particles to a highly refractory Y-Mg-Si-Al-O-N oxynitride glass. Taking advantage of both constituents, the brittle particulate composites exhibit much better fracture strength and toughness and higher elastic moduli than the glassy matrix. Due to the easy crystallization of the selected glass, a further improvement is attainable through a crystallization treatment of the matrix. Fracture toughness and Young's modulus as high as 5.4 MPa.m[sup 0.5] and 215 GPa respectively have been measured on the glass-ceramic composite containing 50 vol.% SiC.

  20. Adding and Deleting Images

    EPA Pesticide Factsheets

    Images are added via the Drupal WebCMS Editor. Once an image is uploaded onto a page, it is available via the Library and your files. You can edit the metadata, delete the image permanently, and/or replace images on the Files tab.

  1. What Value "Value Added"?

    ERIC Educational Resources Information Center

    Richards, Andrew

    2015-01-01

    Two quantitative measures of school performance are currently used, the average points score (APS) at Key Stage 2 and value-added (VA), which measures the rate of academic improvement between Key Stage 1 and 2. These figures are used by parents and the Office for Standards in Education to make judgements and comparisons. However, simple…

  2. ADS in a Nutshell

    NASA Astrophysics Data System (ADS)

    Demleitner, M.; Eichhorn, G.; Grant, C. S.; Accomazzi, A.; Murray, S. S.; Kurtz, M. J.

    1999-05-01

    The bibliographic databases maintained by the NASA Astrophysics Data System are updated approximately biweekly with records gathered from over 125 sources all over the world. Data are either sent to us electronically, retrieved by our staff via semi-automated procedures, or entered in our databases through supervised OCR procedures. PERL scripts are run on the data to convert them from their incoming format to our standard format so that they can be added to the master database at SAO. Once new data has been added, separate index files are created for authors, objects, title words, and text word, allowing these fields to be searched for individually or in combination with each other. During the indexing procedure, discipline-specific knowledge is taken into account through the use of rule-based procedures performing string normalization, context-sensitive word translation, and synonym and stop word replacement. Once the master text and index files have been updated at SAO, an automated procedure mirrors the changes in the database to the ADS mirror site via a secure network connection. The use of a public domain software tool called rsync allows incremental updating of the database files, with significant savings in the amount of data being transferred. In the past year, the ADS Abstract Service databases have grown by approximately 30%, including 50% growth in Physics, 25% growth in Astronomy and 10% growth in the Instrumentation datasets. The ADS Abstract Service now contains over 1.4 million abstracts (475K in Astronomy, 430K in Physics, 510K in Instrumentation, and 3K in Preprints), 175,000 journal abstracts, and 115,000 full text articles. In addition, we provide links to over 40,000 electronic HTML articles at other sites, 20,000 PDF articles, and 10,000 postscript articles, as well as many links to other external data sources.

  3. Origin of broad NIR photoluminescence in bismuthate glass and Bi-doped glasses at room temperature.

    PubMed

    Peng, Mingying; Zollfrank, Cordt; Wondraczek, Lothar

    2009-07-15

    Bi-doped glasses with broadband photoluminescence in the near-infrared (NIR) spectral range are presently receiving significant consideration for potential applications in telecommunications, widely tunable fiber lasers and spectral converters. However, the origin of NIR emission remains disputed. Here, we report on NIR absorption and emission properties of bismuthate glass and their dependence on the melting temperature. Results clarify that NIR emission occurs from the same centers as it does in Bi-doped glasses. The dependence of absorption and NIR emission of bismuthate glasses on the melting temperature is interpreted as thermal dissociation of Bi(2)O(3) into elementary Bi. Darkening of bismuthate glass melted at 1300 °C is due to the agglomeration of Bi atoms. The presence of Bi nanoparticles is confirmed by transmission electron microscopy, high-resolution energy dispersive x-ray spectroscopy and element distribution mapping. By adding antimony oxide as an oxidation agent to the glass, NIR emission centers can be eliminated and Bi(3+) is formed. By comparing with atomic spectral data, absorption bands at ∼320 , ∼500 , 700 , 800 and 1000 nm observed in Bi-doped glasses are assigned to Bi(0) transitions [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text], respectively, and broadband NIR emission is assigned to the transition [Formula: see text].

  4. High chloride content calcium silicate glasses.

    PubMed

    Chen, Xiaojing; Karpukhina, Natalia; Brauer, Delia S; Hill, Robert G

    2017-03-08

    Chloride is known to volatilize from silicate glass melts and until now, only a limited number of studies on oxychloride silicate glasses have been reported. In this paper we have synthesized silicate glasses that retain large amounts of CaCl2. The CaCl2 has been added to the calcium metasilicate composition (CaO·SiO2). Glasses were produced via a melt quench route and an average of 70% of the chloride was retained after melting. Up to 31.6 mol% CaCl2 has been successfully incorporated into these silicate glasses without the occurrence of crystallization. (29)Si MAS-NMR spectra showed the silicon being present mainly as a Q(2) silicate species. This suggests that chloride formed Cl-Ca(n) species, rather than Si-Cl bonds. Upon increasing the CaCl2 content, the Tg reduced markedly from 782 °C to 370 °C. Glass density and glass crystallization temperature decreased linearly with an increase in the CaCl2 content. However, both linear regressions revealed a breakpoint at a CaCl2 content just below 20 mol%. This might be attributed to a significant change in the structure and is also correlated with the nature of the crystallizing phases formed upon heat treatment. The glasses with less than 19.2 mol% CaCl2 crystallized to wollastonite, whilst the compositions with CaCl2 content equal to or greater than 19.2 mol% are thought to crystallize to CaCl2. In practice, the crystallization of CaCl2 could not occur until the crystallization temperature fell below the melting point of CaCl2. The implications of the results along with the high chloride retention are discussed.

  5. Devitrification of colloidal glasses in real space.

    PubMed

    Simeonova, Nikoleta B; Dullens, Roel P A; Aarts, Dirk G A L; de Villeneuve, Volkert W A; Lekkerkerker, Henk N W; Kegel, Willem K

    2006-04-01

    Confocal scanning laser microscopy has been used to quantitatively analyze the structure and dynamics of concentrated suspensions of spherical colloids in which the magnitude of the short-range attractive potential is increased by adding nonadsorbing polymers. These systems undergo a reentrant glass transition upon increasing polymer concentration. We find that melting of the glass is accompanied by significant changes in the displacement distribution and its moments. However, no significant variations have been detected in the shapes of the displacement distributions. Moreover, structural correlation functions and the magnitude of local density fluctuations do not vary significantly between the glass states and the fluid. Considering our experimental setup, these observations imply that local density fluctuations cannot be larger than a few percent of the average density.

  6. Reversing Glass Wettability

    NASA Technical Reports Server (NTRS)

    Frazier, D. O.; Smith, J. E., Jr.; Kaukler, W. F.

    1985-01-01

    Treatment reverses wettability of glassware: Liquids that normally wet glass no longer do, and those that do not wet glass are made to do so. Useful in research on container effects in nucleation and growth of secondary phase from solution. Treatment consists of spreading 3 percent (by weight) solution of silicone oil in hexane isomers over glass, drying in air, and curing at 300 degrees C in vacuum for one hour.

  7. Diamond turning of glass

    SciTech Connect

    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

  8. Drugstore Reading Glasses

    NASA Astrophysics Data System (ADS)

    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.

  9. Chalcogenide glass microsphere laser.

    PubMed

    Elliott, Gregor R; Murugan, G Senthil; Wilkinson, James S; Zervas, Michalis N; Hewak, Daniel W

    2010-12-06

    Laser action has been demonstrated in chalcogenide glass microsphere. A sub millimeter neodymium-doped gallium lanthanum sulphide glass sphere was pumped at 808 nm with a laser diode and single and multimode laser action demonstrated at wavelengths between 1075 and 1086 nm. The gallium lanthanum sulphide family of glass offer higher thermal stability compared to other chalcogenide glasses, and this, along with an optimized Q-factor for the microcavity allowed laser action to be achieved. When varying the pump power, changes in the output spectrum suggest nonlinear and/or thermal effects have a strong effect on laser action.

  10. Apollo 15 green glasses.

    NASA Technical Reports Server (NTRS)

    Ridley, W. I.; Reid, A. M.; Warner, J. L.; Brown, R. W.

    1973-01-01

    The samples analyzed include 28 spheres, portions of spheres, and angular fragments from soil 15101. Emerald green glasses from other soils are identical to those from 15101. The composition of the green glass is unlike that of any other major lunar glass group. The Fe content is comparable to that in mare basalts, but Ti is much lower. The Mg content is much higher than in most lunar materials analyzed to date, and the Cr content is also high. The low Al content is comparable to that of mare basalt glasses.

  11. Glass--Sand + Imagination

    NASA Astrophysics Data System (ADS)

    Kolb, Kenneth E.; Kolb, Doris K.

    2000-07-01

    Glass is older than recorded history, and yet it is as new as tomorrow! How, when, or where man first learned to make glass is not known, but we do know that the ancient Egyptians were making glass articles as early as 2,600 B.C.E. (The making of glass beads may have begun as much as 3000 years earlier.) They used it to make jewelry and luxury items, such as decorative bowls and perfume bottles, available only to the wealthy.

  12. High-Intensity Plasma Glass Melter Final Technical Report

    SciTech Connect

    Gonterman, J. Ronald; Weinstein, Michael A.

    2006-10-27

    The purpose of this project was to demonstrate the energy efficiency and reduced emissions that can be obtained with a dual torch DC plasma transferred arc-melting system. Plasmelt Glass Technologies, LLC was formed to solicit and execute the project, which utilize a full-scale test melter system. The system is similar to the one that was originally constructed by Johns Manville, but Plasmelt has added significant improvements to the torch design and melter system that has extended the original JM short torch lives. The original JM design has been shown to achieve melt rates 5 to 10 times faster than conventional gas or electric melting, with improved energy efficiency and reduced emissions. This project began on 7/28/2003 and ended 7/27/06. A laboratory scale melter was designed, constructed, and operated to conduct multiple experimental melting trials on various glass compositions. Glass quality was assessed. Although the melter design is generic and equally applicable to all sectors within the glass industry, the development of this melter has focused primarily on fiberglass with additional exploratory melting trials of frits, specialty, and minerals-melting applications. Throughput, energy efficiency, and glass quality have been shown to be heavily dependent on the selected glass composition. During this project, Plasmelt completed the proof-of-concept work in our Boulder, CO Lab to show the technical feasibility of this transferred-arc plasma melter. Late in the project, the work was focused on developing the processes and evaluating the economic viability of plasma melting aimed at the specific glasses of interest to specific client companies. Post project work is on going with client companies to address broader non-glass materials such as refractories and industrial minerals. Exploratory melting trials have been conducted on several glasses of commercial interest including: C-glass, E-glass, S-Glass, AR-Glass, B-glass, Lighting Glass, NE-Glass, and various

  13. Determination of chemical speciations of cerium in nuclear waste glasses

    SciTech Connect

    Gong, Meiling; Li, Hong

    1996-12-31

    Cerium oxides have been widely used as a surrogate for plutonium in the investigation of the melt and durability behavior of simulated nuclear waste glasses. It is well known that there is a cerous-ceric equilibrium in silicate glasses under normal melting conditions. The position of this equilibrium depends on glass composition, melting temperature, furnace atmosphere, and possibly the total amounts of cerium in glass. The oxidation state of cerium affects total solubility of cerium in glass, solubilities of other components in glass, viscosities and liquidus temperatures of the melts, and the chemical durability of the glasses. A procedure was developed for the determination of the ceric and cerous distribution. The glass was ground to small particles of less than 300 meshes and was dissolved in mixture of HF and H{sub 2}SO{sub 4}. The ceric oxide was graduately reduced to cerous species in the presence of HF acid during the dissolution. To compensate the change of the equilibrium during the dissolution, a calibration curve is made with a mixture of standard solution of ceric sulphate and one gram of glass of the same composition containing no cerium. Boric acid was added to complex the fluoride ions, and the resultant solution was titrated potentiometrically with 0.01 N ferrous ammonium sulphate solution. The corrected ceric concentration was obtained on the calibration curve. The total cerium content in the above solution was analyzed using ICP-AES and the cerous content was the difference between the total Ce and Ce(+4).

  14. Potential for energy conservation in the glass industry

    SciTech Connect

    Garrett-Price, B.A.; Fassbender, A.G.; Bruno, G.A.

    1986-06-01

    While the glass industry (flat glass, container glass, pressed and blown glass, and insulation fiber glass) has reduced its specific energy use (Btu/ton) by almost 30% since 1972, significant potential for further reduction still remains. State-of-the-art technologies are available which could lead to incremental improvements in glass industry energy productivity; however, these technologies must compete for capital with projects undertaken for other reasons (e.g., capacity expansion, equipment rebuild, labor cost reduction, product quality improvement, or compliance with environmental, health or safety regulations). Narrowing profit margins in the large tonnage segments of the glass industry in recent years and the fact that energy costs represent less than 25% of the value added in glass manufacture have combined to impede the widespread adoption of many state-of-the-art conservation technologies. Savings in energy costs alone have not provided the incentive to justify the capital expenditures required to realize the energy savings. Beyond implementation of state-of-the-art technologies, significant potential energy savings could accrue from advanced technologies which represent a radical departure from current glass making technology. Long-term research and development (R and D) programs, which address the technical and economic barriers associated with advanced, energy-conserving technologies, offer the opportunity to realize this energy-saving potential.

  15. Metallic glass composition. [That does not embrittle upon annealing

    DOEpatents

    Kroeger, D.M.; Koch, C.C.

    1984-09-14

    This patent pertains to a metallic glass alloy that is either iron-based or nickel-based or based on a mixture of iron and nickel, containing lesser amounts of elements selected from the group boron, silicon, carbon and phosphorous to which is added an amount of a ductility-enhancing element selected from the group cerium, lanthanum, praseodymium and neodymium sufficient to increase ductility of the metallic glass upon annealing.

  16. Rare Earth Phosphate Glass and Glass-Ceramic Proton Conductors

    SciTech Connect

    De Jonghe, Lutgard C.; Ray, Hannah L.; Wang, Ruigang

    2008-12-03

    The structure and conductivity of cerium and lanthanum phosphate glasses and glass-ceramics were investigated. The effects of varying the metal to phosphate ratio in the glasses, doping LaP3O9 glasses with Ce, and recrystallization of CeP3O9 glasses, on the glasses' microstructure and total conductivity were investigated using XRD, SEM, and AC impedance techniques. Strong increases in conductivity occurred when the glasses were recrystallized: the conductivity of a cerium metaphosphate glass increased conductivity after recrystallization from 10-7.5 S/cm to 10-6 S/cm at 400oC.

  17. Lanthanoides in Glass and Glass Ceramics

    NASA Astrophysics Data System (ADS)

    Meinhardt, Jürgen; Kilo, Martin; Somorowsky, Ferdinand; Hopp, Werner

    2017-03-01

    Many types of glass contain lanthanoides; among them, special glass for optical applications is the one with the highest content of lanthanoides. The precise determination of the lanthanoides' concentration is performed by inductively coupled plasma-optical emission spectrometry (ICP-OES). However, up to now, there are no established standard processes guaranteeing a uniform approach to the lanthanoide analysis. The knowledge of the lanthanoides' concentrations is necessary on the microscale in some cases, especially if a suitable separation and recycling procedure is to be applied. Here, the analysis is performed by energy-dispersive X-ray (EDX) or wavelength-dispersive X-ray (WDX) analytics in the scanning electron microscope.

  18. Getting Started with Glass

    ERIC Educational Resources Information Center

    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…

  19. Glasses and Contact Lenses

    MedlinePlus

    ... about special eyewear you can wear on the field. With glasses, you'll also want to find out how to clean them properly. And it helps if you have a glasses case and put them in it when you're not wearing them. The last thing you want is to sit on your ...

  20. Glasses and Contact Lenses

    MedlinePlus

    ... dientes Video: Getting an X-ray Glasses and Contact Lenses KidsHealth > For Kids > Glasses and Contact Lenses Print A A A What's in this ... together the way they should. But eyeglasses or contact lenses, also called corrective lenses, can help most ...

  1. Surface Conductive Glass.

    ERIC Educational Resources Information Center

    Tanaka, John; Suib, Steven L.

    1984-01-01

    Discusses the properties of surface-conducting glass and the chemical nature of surface-conducting stannic (tin) oxide. Also provides the procedures necessary for the preparation of surface-conducting stannic oxide films on glass substrates. The experiment is suitable for the advanced inorganic chemistry laboratory. (JN)

  2. Dramatic Stained Glass.

    ERIC Educational Resources Information Center

    Prater, Michael

    2002-01-01

    Describes an art project that is appropriate for students in fifth through twelfth grade in which they create Gothic-style stained-glass windows. Discusses how college students majoring in elementary education created stained-glass windows. Addresses how to adapt this lesson for younger students. (CMK)

  3. Indium fluoride glass fibers

    NASA Astrophysics Data System (ADS)

    Saad, Mohammed

    2012-03-01

    Fluoride glasses are the only material that transmit light from ultraviolet to mid-infrared and can be drawn into industrial optical fibers. The mechanical and optical properties of new indium fluoride glass fibers have been investigated. Multimode fiber 190 microns, has very high mechanical strength greater than 100 kpsi and optical loss as low as 45 dB/km between 2 and 4 microns. Unlike chalcogenide glass fibers, indium fluoride fiber has a wide transmission window from 0.3 to 5.5 microns without any absorption peak. Indium fluoride glass fibers are the technology of choice for all application requiring transmission up to 5 micron such as infrared contour measure (IRCM) and chemical sensing. Furthermore, Indium fluoride glasses have low phonon energy and can be heavily doped and co-doped whit rare-earth elements. Therefore they are very promising candidates for infrared fiber lasers.

  4. Photoprotection by window glass, automobile glass, and sunglasses.

    PubMed

    Tuchinda, Chanisada; Srivannaboon, Sabong; Lim, Henry W

    2006-05-01

    In daily activity, much time is spent indoors and in vehicles. Although the adverse effect of ultraviolet (UV) radiation is now well recognized and active public education programs on photoprotection have been undertaken, the role of window glass in photoprotection has been rarely addressed. It has been known for some time that window glass filters out UVB and transmits UVA and visible light. Recent developments in the glass industry have resulted in glass that provides broad UV protection without the historically associated loss of visible light transmission. Factors affecting UV-protective properties of glass are glass type, glass color, interleave between glass, and glass coating. In this article, photoprotection by window glass, automobile glass, and sunglasses is reviewed.

  5. Defense HLW Glass Degradation Model

    SciTech Connect

    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.

  6. Supersymmetry of AdS and flat IIB backgrounds

    NASA Astrophysics Data System (ADS)

    Beck, S.; Gutowski, J.; Papadopoulos, G.

    2015-02-01

    We present a systematic description of all warped AdS n × w M 10- n and IIB backgrounds and identify the a priori number of supersymmetries N preserved by these solutions. In particular, we find that the AdS n backgrounds preserve for n ≤ 4 and for 4 < n ≤ 6 supersymmetries and for suitably restricted. In addition under some assumptions required for the applicability of the maximum principle, we demonstrate that the Killing spinors of AdS n backgrounds can be identified with the zero modes of Dirac-like operators on M 10- n establishing a new class of Lichnerowicz type theorems. Furthermore, we adapt some of these results to backgrounds with fluxes by taking the AdS radius to infinity. We find that these backgrounds preserve for 2 < n ≤ 4 and for 4 < n ≤ 7 supersymmetries. We also demonstrate that the Killing spinors of AdS n × w M 10- n do not factorize into Killing spinors on AdS n and Killing spinors on M 10- n .

  7. [Value-Added--Adding Economic Value in the Food Industry].

    ERIC Educational Resources Information Center

    Welch, Mary A., Ed.

    1989-01-01

    This booklet focuses on the economic concept of "value added" to goods and services. A student activity worksheet illustrates how the steps involved in processing food are examples of the concept of value added. The booklet further links food processing to the idea of value added to the Gross National Product (GNP). Discussion questions,…

  8. Effect of different glasses in glass bonded zeolite

    SciTech Connect

    Lewis, M.A.; Ackerman, J.P.; Verma, S.

    1995-05-01

    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.

  9. Redox-Dependent Solubility of Technetium in Low Activity Waste Glass

    SciTech Connect

    Soderquist, Chuck Z.; Schweiger, Michael J.; Kim, Dong-Sang; Lukens, Wayne W.; Mccloy, John S.

    2014-03-01

    The solubility of technetium was measured in a Hanford low activity waste glass simulant. The simulant glass was melted, quenched and pulverized to make a stock of powdered glass. A series of glass samples were prepared using the powdered glass and varying amounts of solid potassium pertechnetate. Samples were melted at 1000°C in sealed fused quartz ampoules. After cooling, the bulk glass and the salt phase above the glass (when present) were sampled for physical and chemical characterization. Technetium was found in the bulk glass up to 2000 ppm (using the glass as prepared) and 3000 ppm (using slightly reducing conditions). The chemical form of technetium obtained by x-ray absorption near edge spectroscopy can be mainly assigned to isolated Tc(IV), with a minority of Tc(VII) in some glasses and TcO2 in two glasses. The concentration and speciation of technetium depends on glass redox and amount of technetium added. Solid crystals of pertechnetate salts were found in the salt cake layer that formed at the top of some glasses during the melt.

  10. Development of Chemically and Thermally Robust Lithium Fast Ion Conducting Chalcogenide Glasses

    NASA Technical Reports Server (NTRS)

    Martin, Steve W.; Hagedorn, Norman (Technical Monitor)

    2002-01-01

    In this project, a new research thrust into the development of an entirely new class of FIC glasses has begun that may lead to a new set of optimized thin-film lithium ion conducting materials. New chemically robust FIC glasses are being prepared that are expected to exhibit unusually high chemical and electrochemical stability. New thermally robust FIC glasses are being prepared that exhibit softening points in excess of 500 C which will dramatically expand the usable operating temperature range of batteries, fuel-cells, and sensors using such electrolytes. Glasses are being explored in the general compositional series xLi2S+ yGa2S3 + (1-x-y)GeS2. Li2S is added as the source of the conductive lithium ions. GeS2 is the base glass-forming phase and the trivalent sulfides, Ga2S3, is added to increase the "refractoniness" of the glass, that is to significantly increase the softening point of the glass as well as its chemical stability. By optimizing the composition of the glass, new glasses and glass-ceramic FIC materials have been prepared with softening points in excess of 500 C and conductivities above 10(exp -3)/Ohm cm at room temperature. These latter attributes are currently not available in any FIC glasses to date.

  11. Glass electrolyte composition

    DOEpatents

    Kucera, Gene H.; Roche, Michael F.

    1985-01-01

    An ionically conductive glass is disclosed for use as electrolyte in a high temperature electrochemical cell, particularly a cell with sodium anode and sulfur cathode. The glass includes the constituents Na.sub.2 O, ZrO.sub.2, Al.sub.2 O.sub.3 and SiO.sub.2 in selected proportions to be a single phase solid solution substantially free of crystalline regions and undissolved constituents. Other advantageous properties are an ionic conductivity in excess of 2.times.10.sup.-3 (ohm-cm).sup.-1 at 300.degree. C. and a glass transition temperature in excess of 500.degree. C.

  12. Glass electrolyte composition

    DOEpatents

    Kucera, G.H.; Roche, M.F.

    1985-01-08

    An ionically conductive glass is disclosed for use as electrolyte in a high temperature electrochemical cell, particularly a cell with sodium anode and sulfur cathode. The glass includes the constituents Na/sub 2/O, ZrO/sub 2/, Al/sub 2/O/sub 3/ and SiO/sub 2/ in selected proportions to be a single phase solid solution substantially free of crystalline regions and undissolved constituents. Other advantageous properties are an ionic conductivity in excess of 2 x 10/sup -3/ (ohm-cm)/sup -1/ at 300/sup 0/C and a glass transition temperature in excess of 500/sup 0/C.

  13. Sodalite as a vehicle to increase Re retention in waste glass simulant during vitrification

    SciTech Connect

    Luksic, Steven A.; Riley, Brian J.; Parker, Kent E.; Hrma, Pavel

    2016-10-01

    Technetium retention during Hanford waste vitrification can be increased by inhibiting technetium volatility from the waste glass melter. Incorporating technetium into a mineral phase, such as sodalite, is one way to achieve this. Rhenium-bearing sodalite was tested as a vehicle to transport perrhenate (ReO4-), a nonradioactive surrogate for pertechnetate (TcO4-), into high-level (HLW) and low-activity waste (LAW) glasses. After melting feeds of these two glasses, the retention of rhenium was measured and compared with the rhenium retention in glass prepared from a feed containing Re2O7 as a standard. The rhenium retention was 21% higher for HLW glass and 85% higher for LAW glass when added to samples in the form of sodalite as opposed to when it was added as Re2O7, demonstrating the efficacy of this type of an approach.

  14. AdS3 Solutions of IIB Supergravity

    SciTech Connect

    Kim, Nakwoo

    2005-12-02

    We consider pure D3-brane configurations of IIB string theory which lead to supergravity solutions containing an AdS3 factor. They can provide new examples of AdS3/CFT2 examples on D3-branes whose worldvolume is partially compactified. When the internal 7 dimensional space is non-compact, they are related to fluctuations of higher dimensional AdS/CFT duality examples, thus dual to the BPS operators of D = 4 superconformal field theories. We find that supersymmetry requires the 7 dimensional space is warped Hopf-fibration of (real) 6 dimensional Kahler manifolds.

  15. A-thermal elastic behavior of silicate glasses

    NASA Astrophysics Data System (ADS)

    Rabia, Mohammed Kamel; Degioanni, Simon; Martinet, Christine; Le Brusq, Jacques; Champagnon, Bernard; Vouagner, Dominique

    2016-02-01

    Depending on the composition of silicate glasses, their elastic moduli can increase or decrease as function of the temperature. Studying the Brillouin frequency shift of these glasses versus temperature allows the a-thermal composition corresponding to an intermediate glass to be determined. In an intermediate glass, the elastic moduli are independent of the temperature over a large temperature range. For sodium alumino-silicate glasses, the a-thermal composition is close to the albite glass (NaAlSi3O8). The structural origin of this property is studied by in situ high temperature Raman scattering. The structure of the intermediate albite glass and of silica are compared at different temperatures between room temperature and 600 °C. When the temperature increases, it is shown that the high frequency shift of the main band at 440 cm-1 in silica is a consequence of the cristobalite-like alpha-beta transformation of 6-membered rings. This effect is stronger in silica than bond elongation (anharmonic effects). As a consequence, the elastic moduli of silica increase as the temperature increases. In the albite glass, the substitution of 25% of Si4+ ions by Al3+ and Na+ ions decreases the proportion of SiO2 6-membered rings responsible for the silica anomaly. The effects of the silica anomaly balance the anharmonicity in albite glass and give rise to an intermediate a-thermal glass. Different networks, formers or modifiers, can be added to produce different a-thermal glasses with useful mechanical or chemical properties.

  16. Action growth for AdS black holes

    NASA Astrophysics Data System (ADS)

    Cai, Rong-Gen; Ruan, Shan-Ming; Wang, Shao-Jiang; Yang, Run-Qiu; Peng, Rong-Hui

    2016-09-01

    Recently a Complexity-Action (CA) duality conjecture has been proposed, which relates the quantum complexity of a holographic boundary state to the action of a Wheeler-DeWitt (WDW) patch in the anti-de Sitter (AdS) bulk. In this paper we further investigate the duality conjecture for stationary AdS black holes and derive some exact results for the growth rate of action within the Wheeler-DeWitt (WDW) patch at late time approximation, which is supposed to be dual to the growth rate of quantum complexity of holographic state. Based on the results from the general D-dimensional Reissner-Nordström (RN)-AdS black hole, rotating/charged Bañados-Teitelboim-Zanelli (BTZ) black hole, Kerr-AdS black hole and charged Gauss-Bonnet-AdS black hole, we present a universal formula for the action growth expressed in terms of some thermodynamical quantities associated with the outer and inner horizons of the AdS black holes. And we leave the conjecture unchanged that the stationary AdS black hole in Einstein gravity is the fastest computer in nature.

  17. Super ionic conductive glass

    DOEpatents

    Susman, S.; Volin, K.J.

    Described is an ionically conducting glass for use as a solid electrolyte in a power or secondary cell containing an alkali metal-containing anode and a cathode separated by an alkali metal ion conducting glass having an ionic transference number of unity and the general formula: A/sub 1 + x/D/sub 2-x/3/Si/sub x/P/sub 3 - x/O/sub 12 - 2x/3/, wherein A is a network modifier for the glass and is an alkali metal of the anode, D is an intermediate for the glass and is selected from the class consisting of Zr, Ti, Ge, Al, Sb, Be, and Zn and X is in the range of from 2.25 to 3.0. Of the alkali metals, Na and Li are preferred and of the intermediate, Zr, Ti and Ge are preferred.

  18. Super ionic conductive glass

    DOEpatents

    Susman, Sherman; Volin, Kenneth J.

    1984-01-01

    An ionically conducting glass for use as a solid electrolyte in a power or secondary cell containing an alkali metal-containing anode and a cathode separated by an alkali metal ion conducting glass having an ionic transference number of unity and the general formula: A.sub.1+x D.sub.2-x/3 Si.sub.x P.sub.3-x O.sub.12-2x/3, wherein A is a network modifier for the glass and is an alkali metal of the anode, D is an intermediate for the glass and is selected from the class consisting of Zr, Ti, Ge, Al, Sb, Be, and Zn and X is in the range of from 2.25 to 3.0. Of the alkali metals, Na and Li are preferred and of the intermediate, Zr, Ti and Ge are preferred.

  19. Seeing Glass Contractors Clearly.

    ERIC Educational Resources Information Center

    Deliberato, Jerry

    2003-01-01

    Offers seven tips for finding and working with an effective glass contractor. For example, schools should consider the company's reputation and longevity of service, and whether it has in-house engineering capabilities. (EV)

  20. Glass formation in microgravity

    NASA Technical Reports Server (NTRS)

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

    1987-01-01

    An account is given of containerless glass-forming experiments conducted aboard the Space Shuttle in 1985, using a single-axis acoustic levitator furnace apparatus. An attempt was made to obtain quantitative evidence for the suppression of heterogeneous nucleation/crystallization in containerless melts under microgravity conditions, as well as to study melt homogenization in the absence of gravity-driven convection and assess the feasibility of laser fusion target glass microsphere preparation with a microgravity apparatus of the present type. A ternary calcia-gallia-silica glass thus obtained indicated a 2-3-fold increase in glass-formation tendency for this material composition in microgravity, by comparison with 1g.

  1. Glass Stronger than Steel

    DOE R&D Accomplishments Database

    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. Value Added in English Schools

    ERIC Educational Resources Information Center

    Ray, Andrew; McCormack, Tanya; Evans, Helen

    2009-01-01

    Value-added indicators are now a central part of school accountability in England, and value-added information is routinely used in school improvement at both the national and the local levels. This article describes the value-added models that are being used in the academic year 2007-8 by schools, parents, school inspectors, and other…

  3. Constructing the AdS dual of a Fermi liquid: AdS black holes with Dirac hair

    NASA Astrophysics Data System (ADS)

    Čubrović, Mihailo; Zaanen, Jan; Schalm, Koenraad

    2011-10-01

    We provide evidence that the holographic dual to a strongly coupled charged Fermi liquid has a non-zero fermion density in the bulk. We show that the pole-strength of the stable quasiparticle characterizing the Fermi surface is encoded in the AdS probability density of a single normalizable fermion wavefunction in AdS. Recalling Migdal's theorem which relates the pole strength to the Fermi-Dirac characteristic discontinuity in the number density at ω F , we conclude that the AdS dual of a Fermi liquid is described by occupied on-shell fermionic modes in AdS. Encoding the occupied levels in the total spatially averaged probability density of the fermion field directly, we show that an AdS Reissner-Nordström black holein a theory with charged fermions has a critical temperature, at which the system undergoes a first-order transition to a black hole with a non-vanishing profile for the bulk fermion field. Thermodynamics and spectral analysis support that the solution with non-zero AdS fermion-profile is the preferred ground state at low temperatures.

  4. Development of a Specialized Pack for Shipping Water Specimens in Glass Bottles.

    DTIC Science & Technology

    1982-08-01

    AD-R120 514 DEVELOPMENT OF A SPECIALIZED PACK FOR SHIPPING WATER ji’j SPECIMENS IN GLASS BOTTLES (U) AIR FORCE PACKAGING EVALUATION AGENCY WRIGHT...787-4519 immi Commercial (513) 257-4234 DIVIUCINT (W A SPICIALIZED PACK FOR SHIPING MATh SPECIMUS IN GLASS BOTTLS • S I) Air Force Packaging...breakage, during shipment, of glass bottles filled with water specimens. A prototype of the specialized container, employing the proposed Poly-Foam

  5. Frangible glass canisters

    NASA Technical Reports Server (NTRS)

    Seifert, R.

    1972-01-01

    The need for a canister that can release its contents without disturbing the contents dynamically is discussed. The solution of this problem by the use of a frangible glass canister is considered. The basic theory applicable to frangible glass and the method of initiating a command flaw are discussed. A brief description of the test program and the results of a flight test are presented.

  6. Method for making glass nonfogging

    DOEpatents

    Lord, David E.; Carter, Gary W.; Petrini, Richard R.

    1979-01-01

    A method for rendering glass nonfogging (to condensation fog) by sandwiching the glass between two electrodes such that the glass functions as the dielectric of a capacitor, a large alternating current (AC) voltage is applied across the electrodes for a selected time period causing the glass to absorb a charge, and the electrodes are removed. The glass absorbs a charge from the electrodes rendering it nonfogging. The glass surface is undamaged by application of the AC voltage, and normal optical properties are unaffected. This method can be applied to optical surfaces such as lenses, auto windshields, mirrors, etc., wherever condensation fog on glass is a problem.

  7. Baseline LAW Glass Formulation Testing

    SciTech Connect

    Kruger, Albert A.; Mooers, Cavin; Bazemore, Gina; Pegg, Ian L.; Hight, Kenneth; Lai, Shan Tao; Buechele, Andrew; Rielley, Elizabeth; Gan, Hao; Muller, Isabelle S.; Cecil, Richard

    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.

  8. Molecular dynamics simulation of alkali borate glass using coordination dependent potential

    SciTech Connect

    Park, B.; Cormack, A.N.

    1997-12-31

    The structure of sodium borate glass was investigated by molecular dynamics simulation using coordination dependent potential model. The simulated alkali borate glass consists of basic units, BO{sub 3} triangle, BO{sub 4} tetrahedra and structural groups such as boroxol ring and triborate units. The coordination of boron is converted from 3 to 4 by adding alkali oxide.

  9. Containerless synthesis of interesting glasses

    NASA Technical Reports Server (NTRS)

    Weinberg, Michael C.

    1990-01-01

    One aspect of containerless glass experimentation was thoroughly examined: glass forming ability. It is argued that although containerless processing will abet glass formation, other ground-based methods can do the job better. However, these methods have limitations, such as sample dimensions and concomitant ability to make property measurements. Most importantly, perhaps, is the observation that glass properties are a function of preparation procedure. Thus, it seems as though there still is an argument for use of containerless processing for glass forming.

  10. On the strength of glasses

    PubMed Central

    Wisitsorasak, Apiwat; Wolynes, Peter G.

    2012-01-01

    The remarkable strength of glasses is examined using the random first order transition theory of the glass transition. The theory predicts that strength depends on elastic modulus but also on the configurational energy frozen in when the glass is prepared. The stress catalysis of cooperative rearrangements of the type responsible for the supercooled liquid’s high viscosity account quantitatively for the measured strength of a range of metallic glasses, silica, and a polymer glass. PMID:22988070

  11. AdS-Carroll branes

    NASA Astrophysics Data System (ADS)

    Clark, T. E.; ter Veldhuis, T.

    2016-11-01

    Coset methods are used to determine the action of a co-dimension one brane (domain wall) embedded in (d + 1)-dimensional AdS space in the Carroll limit in which the speed of light goes to zero. The action is invariant under the non-linearly realized symmetries of the AdS-Carroll spacetime. The Nambu-Goldstone field exhibits a static spatial distribution for the brane with a time varying momentum density related to the brane's spatial shape as well as the AdS-C geometry. The AdS-C vector field dual theory is obtained.

  12. ADS Based on Linear Accelerators

    NASA Astrophysics Data System (ADS)

    Pan, Weimin; Dai, Jianping

    An accelerator-driven system (ADS), which combines a particle accelerator with a subcritical core, is commonly regarded as a promising device for the transmutation of nuclear waste, as well as a potential scheme for thorium-based energy production. So far the predominant choice of the accelerator for ADS is a superconducting linear accelerator (linac). This article gives a brief overview of ADS based on linacs, including the motivation, principle, challenges and research activities around the world. The status and future plan of the Chinease ADS (C-ADS) project will be highlighted and discussed in depth as an example.

  13. AdS spacetimes from wrapped D3-branes

    NASA Astrophysics Data System (ADS)

    Gauntlett, Jerome P.; MacConamhna, Oisín A. P.

    2007-12-01

    We derive a geometrical characterization of a large class of AdS3 and AdS2 supersymmetric spacetimes in type IIB supergravity with non-vanishing five-form flux using G-structures. These are obtained as special cases of a class of supersymmetric spacetimes with an {{\\bb R}}^{1,1} or {{\\bb R}} (time) factor that are associated with D3 branes wrapping calibrated two or three cycles, respectively, in manifolds with SU(2), SU(3), SU(4) and G2 holonomy. We show how two explicit AdS solutions, previously constructed in gauged supergravity, satisfy our more general G-structure conditions. For each explicit solution, we also derive a special holonomy metric which, although singular, has an appropriate calibrated cycle. After analytic continuation, some of the classes of AdS spacetimes give rise to known classes of BPS bubble solutions with {{\\bb R}}\\times {\\it SO}(4)\\times {\\it SO}(4), {{\\bb R}}\\times {\\it SO}(4)\\times U(1) and {{\\bb R}}\\times {\\it SO}(4) symmetry. These have 1/2, 1/4 and 1/8 supersymmetry, respectively. We present a new class of 1/8 BPS geometries with {{\\bb R}}\\times {\\it SU}(2) symmetry, obtained by analytic continuation of the class of AdS spacetimes associated with D3-brane wrapped on associative three cycles.

  14. Glass microsphere lubrication

    NASA Technical Reports Server (NTRS)

    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

  15. DWPF GLASS BEADS AND GLASS FRIT TRANSPORT DEMONSTRATION

    SciTech Connect

    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

  16. Revisiting the thermodynamic relations in AdS /CMT models

    NASA Astrophysics Data System (ADS)

    Hyun, Seungjoon; Park, Sang-A.; Yi, Sang-Heon

    2017-03-01

    Motivated by the recent unified approach to the Smarr-like relation of anti-de Sitter (AdS) planar black holes in conjunction with the quasilocal formalism on conserved charges, we revisit the quantum statistical and thermodynamic relations of hairy AdS planar black holes. By extending the previous results, we identify the hairy contribution in the bulk and show that the holographic computation can be improved so that it is consistent with the bulk computation. We argue that the first law can be retained in its universal form and that the relation between the on-shell renormalized Euclidean action and its free energy interpretation in gravity may also be undeformed even with the hairy contribution in hairy AdS black holes.

  17. Entanglement entropy for free scalar fields in AdS

    NASA Astrophysics Data System (ADS)

    Sugishita, Sotaro

    2016-09-01

    We compute entanglement entropy for free massive scalar fields in anti-de Sitter (AdS) space. The entangling surface is a minimal surface whose boundary is a sphere at the boundary of AdS. The entropy can be evaluated from the thermal free energy of the fields on a topological black hole by using the replica method. In odd-dimensional AdS, exact expressions of the Rényi entropy S n are obtained for arbitrary n. We also evaluate 1-loop corrections coming from the scalar fields to holographic entanglement entropy. Applying the results, we compute the leading difference of entanglement entropy between two holographic CFTs related by a renormalization group flow triggered by a double trace deformation. The difference is proportional to the shift of a central charge under the flow.

  18. Solutions of free higher spins in AdS

    NASA Astrophysics Data System (ADS)

    Lü, H.; Shao, Kai-Nan

    2011-11-01

    We consider free massive and massless higher integer spins in AdS backgrounds in general D dimensions. We obtain the solutions corresponding to the highest-weight state of the spin-ℓ representations of the SO (2 , D - 1) isometry groups. The solution for the spin-ℓ field is expressed recursively in terms of that for the spin- (ℓ - 1). Thus starting from the explicit spin-0, all the higher-spin solutions can be obtained. These solutions allow us to derive the generalized Breitenlohner-Freedman bound, and analyze the asymptotic falloffs. In particular, solutions with negative mass square in general have falloffs slower than those of the Schwarzschild AdS black holes in the AdS boundaries.

  19. Origin of broad NIR photoluminescence in bismuthate glass and Bi-doped glasses at room temperature

    NASA Astrophysics Data System (ADS)

    Peng, Mingying; Zollfrank, Cordt; Wondraczek, Lothar

    2009-07-01

    Bi-doped glasses with broadband photoluminescence in the near-infrared (NIR) spectral range are presently receiving significant consideration for potential applications in telecommunications, widely tunable fiber lasers and spectral converters. However, the origin of NIR emission remains disputed. Here, we report on NIR absorption and emission properties of bismuthate glass and their dependence on the melting temperature. Results clarify that NIR emission occurs from the same centers as it does in Bi-doped glasses. The dependence of absorption and NIR emission of bismuthate glasses on the melting temperature is interpreted as thermal dissociation of Bi2O3 into elementary Bi. Darkening of bismuthate glass melted at 1300 °C is due to the agglomeration of Bi atoms. The presence of Bi nanoparticles is confirmed by transmission electron microscopy, high-resolution energy dispersive x-ray spectroscopy and element distribution mapping. By adding antimony oxide as an oxidation agent to the glass, NIR emission centers can be eliminated and Bi3+ is formed. By comparing with atomic spectral data, absorption bands at ~320 , ~500 , 700 , 800 and 1000 nm observed in Bi-doped glasses are assigned to Bi0 transitions {}^{4}\\mathrm {S_{3/2}} \\to {}^{2}\\mathrm {P_{3/2}} , {}^{4}\\mathrm {S_{3/2}}\\to {}^{2}\\mathrm {P_{1/2}} , {}^{4}\\mathrm {S_{3/2}}\\to {}^{2}\\mathrm {D_{5/2}} , {}^{4}\\mathrm {S_{3/2}}\\to {}^{2}\\mathrm {D_{3/2}}(2) and {}^{4}\\mathrm {S_{3/2}}\\to {}^{2}\\mathrm {D_{3/2 }}(1) , respectively, and broadband NIR emission is assigned to the transition {}^{2}\\mathrm {D_{3/2}(1)}\\to {}^{4}\\mathrm {S_{3/2}} .

  20. Influence of Alumina Additions on the Physical and Chemical Properties of Lithium-iron-phosphate Glasses

    NASA Astrophysics Data System (ADS)

    Liu, Huali; Yang, Ruijuan; Wang, Yinghui; Liu, Shiquan

    Alumina improves the properties and depresses the devitrification of soda-lime-silicate glasses. Herein, the influence of alumina on the glass transition temperature, density, chemical durability, crystallization of lithium-iron-phosphate (LIP) glass has been investigated. As alumina was added to replace the iron oxide in a base LIP glass with the molar composition of Li2O:Fe2O3:P2O5=30:20:50, the alumina-containing glasses have increased Tg, densities and chemical stabilities than the base glass. When the amount of alumina is increased from 2 to 6 mol, the Tg value slightly increases, whereas the density decreases. However, the smallest weight loss is shown for the glass containing 3.2 mol of alumina. The variations of the properties with alumina are explained based on the infrared structure analysis results. In addition, it is found the either the base or the alumina-containing glasses have surface crystallization upon heat-treatments. Under the same treatment conditions, the base glass exhibits a thin layer of crystallization with LiFeP2O7 as the main phase. In contrast, alumina-containing glasses show much higher degree of crystallization, which is further increased with the amount of alumina. This trend is opposite to that of silicate glass. Besides the LiFeP2O7 main phase, Fe7(PO4) phase is also identified in the crystallized alumina-containing glasses.

  1. Diffusion and chaos from near AdS2 horizons

    NASA Astrophysics Data System (ADS)

    Blake, Mike; Donos, Aristomenis

    2017-02-01

    We calculate the thermal diffusivity D = κ/c ρ and butterfly velocity v B in holographic models that flow to AdS2 × R d fixed points in the infra-red. We show that both these quantities are governed by the same irrelevant deformation of AdS2 and hence establish a simple relationship between them. When this deformation corresponds to a universal dilaton mode of dimension Δ = 2 then this relationship is always given by D = v B 2 /(2 πT).

  2. Towards modeling gadolinium-lead-borate glasses

    SciTech Connect

    Rada, S.; Ristoiu, T.; Rada, M.; Coroiu, I.; Maties, V.; Culea, E.

    2010-01-15

    Infrared spectra of gadolinium-lead-borate glasses of the xGd{sub 2}O{sub 3}.(100 - x)[3B{sub 2}O{sub 3}.PbO] system, where x = 0, 5, 10, 15, 25, 35 and 50 mol.%, have been recorded to explore the role of content of gadolinium ions behaving as glass modifier. The FTIR spectroscopy data for the xGd{sub 2}O{sub 3}.(1 - x)[3B{sub 2}O{sub 3}.PbO] glasses show the structural role of lead ions as a network-formers and of the gadolinium ions network modifiers. Adding of the rare earth ion up to 35 mol.% into the glass matrix, the IR bands characteristic to the studied glasses become sharper and more pronounced. Structural changes, as recognized by analyzing band shapes of IR spectra, revealed that Gd{sub 2}O{sub 3} causes a change from the continuous borate network to the continuous lead-borate network interconnected through Pb-O-B and B-O-B bridges and the transformation of some tetrahedral [BO{sub 4}] units into trigonal [BO{sub 3}] units. Then, gadolinium ions have affinity towards [BO{sub 3}] structural units which contain non-bridging oxygens necessary for the charge compensation because the more electronegative [BO{sub 3}] structural units were implied in the formation of B-O-Gd bonds and the transformation of glass network into a glass ceramic. We propose a possible structural model of building blocks for the formation of continuous random 3B{sub 2}O{sub 3}.PbO network glass used by density functional theory (DFT) calculations. DFT calculations show that lead atoms occupy three different sites in the proposed model. The first is coordinated with six oxygen atoms forming distorted octahedral geometries. The second lead atom has an octahedral oxygen environment and the five longer Pb-O bonds are considered as participating in the metal coordination scheme. The third lead atom has ionic character. In agreement with the results offered by the experimental FTIR data, the theoretical IR data confirm that our proposed structure is highly possible.

  3. Glass ceramic toughened with tetragonal zirconia

    DOEpatents

    Keefer, K.D.

    1984-02-10

    A phase transformation-toughened glass ceramic and a process for making it are disclosed. A mixture of particulate network-forming oxide, network-modifying oxide, and zirconium oxide is heated to yield a homogeneous melt, and this melt is then heat treated to precipitate an appreciable quantity of tetragonal zirconia, which is retained at ambient temperature to form a phase transformation-toughened glass ceramic. Nuclearing agents and stabilizing agents may be added to the mixture to facilitate processing and improve the ceramic's properties. Preferably, the mixture is first melted at a temperature from 1200 to 1700/sup 0/C and is then heat-treated at a temperature within the range of 800 to 1200/sup 0/C in order to precipitate tetragonal ZrO/sub 2/. The composition, as well as the length and temperature of the heat treatment, must be carefully controlled to prevent solution of the precipitated tetragonal zirconia and subsequent conversion to the monoclinic phase.

  4. Glass matrix armor

    DOEpatents

    Calkins, Noel C.

    1991-01-01

    An armor system which utilizes glass. A plurality of constraint cells are mounted on a surface of a substrate, which is metal armor plate or a similar tough material, such that the cells almost completely cover the surface of the substrate. Each constraint cell has a projectile-receiving wall parallel to the substrate surface and has sides which are perpendicular to and surround the perimeter of the receiving wall. The cells are mounted such that, in one embodiment, the substrate surface serves as a sixth side or closure for each cell. Each cell has inside of it a plate, termed the front plate, which is parallel to and in contact with substantially all of the inside surface of the receiving wall. The balance of each cell is completely filled with a projectile-abrading material consisting of glass and a ceramic material and, in certain embodiments, a polymeric material. The glass may be in monolithic form or particles of ceramic may be dispersed in a glass matrix. The ceramic material may be in monolithic form or may be in the form of particles dispersed in glass or dispersed in said polymer.

  5. Sol-Gel Glasses

    NASA Technical Reports Server (NTRS)

    Mukherjee, S. P.

    1985-01-01

    Multicomponent homogeneous, ultrapure noncrystalline gels/gel derived glasses are promising batch materials for the containerless glass melting experiments in microgravity. Hence, ultrapure, homogeneous gel precursors could be used to: (1) investigate the effect of the container induced nucleation on the glass forming ability of marginally glass forming compositions; and (2) investigate the influence of gravity on the phase separation and coarsening behavior of gel derived glasses in the liquid-liquid immiscibility zone of the nonsilicate systems having a high density phase. The structure and crystallization behavior of gels in the SiO2-GeO2 as a function of gel chemistry and thermal treatment were investigated. As are the chemical principles involved in the distribution of a second network former in silica gel matrix being investigated. The procedures for synthesizing noncrystalline gels/gel-monoliths in the SiO2-GeO2, GeO2-PbO systems were developed. Preliminary investigations on the levitation and thermal treatment of germania silicate gel-monoliths in the Pressure Facility Acoustic Levitator were done.

  6. Novel Ge-Ga-Te-CsBr glass system with ultrahigh resolvability of halide.

    PubMed

    Cheng, Ci; Wang, Xunsi; Xu, Tiefeng; Zhu, Qingde; Sun, Lihong; Pan, Zhanghao; Nie, Qiuhua; Zhang, Peiqing; Wu, Yuehao; Dai, Shixun; Shen, Xiang; Zhang, Xianghua

    2015-11-05

    CO2 molecule, one of the main molecules to create new life, should be probed accurately to detect the existence of life in exoplanets. The primary signature of CO2 molecule is approximately 15 μm, and traditional S- and Se-based glass fibers are unsuitable. Thus, Te-based glass is the only ideal candidate glass for far-infrared detection. In this study, a new kind of Te-based chalcohalide glass system was discovered with relatively stable and large optical band gap. A traditional melt-quenching method was adopted to prepare a series of (Ge15Ga10Te75)100-x (CsBr)x chalcogenide glass samples. Experiment results indicate that the glass-forming ability and thermal properties of glass samples were improved when CsBr was added in the host of Ge-Ga-Te glass. Ge-Ga-Te glass could remarkably dissolve CsBr content as much as 85 at.%, which is the highest halide content in all reports for Te-based chalcohalide glasses. Moreover, ΔT values of these glass samples were all above 100 °C. The glass sample (Ge15Ga10Te75)65 (CsBr)35 with ΔT of 119 °C was the largest, which was 7 °C larger than that of Ge15Ga10Te75 host glass. The infrared transmission spectra of these glasses show that the far-infrared cut-off wavelengths of (Ge15Ga10Te75)100-x (CsBr)x chalcogenide glasses were all beyond 25 μm. In conclusion, (Ge15Ga10Te75)100-x (CsBr)x chalcogenide glasses are potential materials for far-infrared optical application.

  7. Sub-Tg features of glasses formed by cooling glycerol under pressure - Additional incompatibility of vibrational with configurational states in the depressurized, high density glass

    NASA Astrophysics Data System (ADS)

    Andersson, Ove; Johari, G. P.

    2016-11-01

    The vibrational state of a glass is naturally incompatible with its configurational state, which makes the glass structurally unstable. When a glass is kept at constant temperature, both the vibrational and configurational states of a glass change with time until it becomes metastable (equilibrium) liquid and the two states become compatible. The process, known as structural relaxation, occurs at a progressively higher rate during heating, and the properties of a glass change accordingly. We add to this incompatibility by depressurizing a glass that had been formed by cooling a liquid under a high pressure, p, and then investigate the effects of the added incompatibility by studying thermal conductivity, κ , and the heat capacity per unit volume ρ Cp of the depressurized glass. We use glycerol for the purpose and study first the changes in the features of κ and of ρ Cp during glass formation on cooling under a set of different p. We then partially depressurize the glass and study the effect of the p-induced instability on the features of κ and ρ Cp as the glass is isobarically heated to the liquid state. At a given low p, the glass configuration that was formed by cooling at high-p had a higher κ than the glass configuration that was formed by cooling at a low p. The difference is more when the glass is formed at a higher p and/or is depressurized to a lower p. On heating at a low p, its κ decreases before its glass-liquid transition range is reached. The effect is the opposite of the increase in κ observed on heating a glass at the same p under which it was formed. It is caused by thermally assisted loss of the added incompatibility of configurational and vibrational states of a high-p formed glass kept at low p. If a glass formed under a low-p is pressurized and then heated under high p, it would show the opposite effect, i.e., its κ would first increase to its high p value before its glass-to-liquid transition range.

  8. Mystery cloud of AD 536

    NASA Technical Reports Server (NTRS)

    Stothers, R. B.

    1984-01-01

    The possible cause of the densest and most persistent dry fog on record, which was observed in Europe and the Middle East during AD 536 and 537, is discussed. The fog's long duration toward the south and the high sulfuric acid signal detected in Greenland in ice cores dated around AD 540 support the theory that the fog was due to the explosion of the Rabaul volcano, the occurrence of which has been dated at about AD 540 by the radiocarbon method.

  9. Bacterial diversity of weathered terrestrial Icelandic volcanic glasses.

    PubMed

    Kelly, Laura C; Cockell, Charles S; Piceno, Yvette M; Andersen, Gary L; Thorsteinsson, Thorsteinn; Marteinsson, Viggo

    2010-11-01

    The diversity of microbial communities inhabiting two terrestrial volcanic glasses of contrasting mineralogy and age was characterised. Basaltic glass from a <0.8 Ma hyaloclastite deposit (Valafell) harboured a more diverse Bacteria community than the younger rhyolitic glass from ∼150-300 AD (Dόmadalshraun lava flow). Actinobacteria dominated 16S rRNA gene clone libraries from both sites, however, Proteobacteria, Acidobacteria and Cyanobacteria were also numerically abundant in each. A significant proportion (15-34%) of the sequenced clones displayed <85% sequence similarities with current database sequences, thus suggesting the presence of novel microbial diversity in each volcanic glass. The majority of clone sequences shared the greatest similarity to uncultured organisms, mainly from soil environments, among these clones from Antarctic environments and Hawaiian and Andean volcanic deposits. Additionally, a large number of clones within the Cyanobacteria and Proteobacteria were more similar to sequences from other lithic environments, included among these Icelandic clones from crystalline basalt and rhyolite, however, no similarities to sequences reported from marine volcanic glasses were observed. PhyloChip analysis detected substantially greater numbers of phylotypes at both sites than the corresponding clone libraries, but nonetheless also identified the basaltic glass community as the richer, containing approximately 29% unique phylotypes compared to rhyolitic glass.

  10. Parametric effects on glass reaction in the unsaturated test method

    SciTech Connect

    Woodland, A.B.; Bates, J.K.; Gerding, T.J.

    1991-12-01

    The Unsaturated Test Method has been applied to study glass reaction under conditions that may be present at the potential Yucca Mountain site, currently under evaluation for storage of reprocessed high-level nuclear waste. The results from five separate sets of parametric experiments are presented wherein test parameters ranging from water contact volume to sensitization of metal in contact with the glass were examined. The most significant effect was observed when the volume of water, as controlled by the water inject volume and interval period, was such to allow exfoliation of reacted glass to occur. The extent of reaction was also influenced to a lesser extent by the degree of sensitization of the 304L stainless steel. For each experiment, the release of cations from the glass and alteration of the glass were examined. The major alteration product is a smectite clay that forms both from precipitation from solution and from in-situ alteration of the glass itself. It is this clay that undergoes exfoliation as water drips from the glass. A comparison is made between the results of the parametric experiments with those of static leach tests. In the static tests the rates of release become progressively reduced through 39 weeks while, in contrast, they remain relatively constant in the parametric experiments for at least 300 weeks. This differing behavior may be attributable to the dripping water environment where fresh water is periodically added and where evaporation can occur.

  11. Glass strengthening and patterning methods

    DOEpatents

    Harper, David C; Wereszczak, Andrew A; Duty, Chad E

    2015-01-27

    High intensity plasma-arc heat sources, such as a plasma-arc lamp, are used to irradiate glass, glass ceramics and/or ceramic materials to strengthen the glass. The same high intensity plasma-arc heat source may also be used to form a permanent pattern on the glass surface--the pattern being raised above the glass surface and integral with the glass (formed of the same material) by use of, for example, a screen-printed ink composition having been irradiated by the heat source.

  12. Glass formation - A contemporary view

    NASA Technical Reports Server (NTRS)

    Uhlmann, D. R.

    1983-01-01

    The process of glass formation is discussed from several perspectives. Particular attention is directed to kinetic treatments of glass formation and to the question of how fast a given liquid must be cooled in order to form a glass. Specific consideration is paid to the calculation of critical cooling rates for glass formation, to the effects of nucleating heterogeneities and transients in nucleation on the critical cooling rates, to crystallization on reheating a glass, to the experimental determination of nucleation rates and barriers to crystal nucleation, and to the characteristics of materials which are most conducive to glass formation.

  13. Coffee-rings and glasses: Colloids out of equilibrium

    NASA Astrophysics Data System (ADS)

    Yunker, Peter Joseph

    observed that the size of these collective rearrangements increases. Thus, the slowing dynamics of aging appear governed by growing correlated domains of particles required for relaxation. Using the same microgel particles, the transformation of a crystal into a glass due to added disorder was investigated by adding smaller particles into a quasi-two-dimensional colloidal crystal. The crystal-glass transition bears structural signatures similar to those of the crystal-fluid transition, but also exhibits a sharp change in dynamic heterogeneity which ``turns-on'' abruptly as a function of increasing disorder. Finally, we investigated the influence of morphology and size on the vibrational properties of disordered clusters of colloidal particles. Spectral features of cluster vibrational modes are found to depend strongly on the average number of nearest neighbors but only weakly on the number of particles in each glassy cluster. The scaling of the median phonon frequency with nearest neighbor number is reminiscent of athermal simulations of the jamming transition.

  14. Waste glass melting stages

    SciTech Connect

    Anderson, L.D.; Dennis, T.; Elliott, M.L.; Hrma, P.

    1993-04-01

    Three different simulated nuclear waste glass feeds, consisting of dried waste and glass frit, were heat treated for 1 hour in a gradient furnace at temperatures ranging from approximately 600[degrees]C--1000[degrees]C. Simulated melter feeds from the Hanford Waste Vitrification Plant (HWVP), the Defense Waste Processing Facility (DWPF), and Kernforschungszentrum Karlsruhe (KfK) in Germany were used. The samples were thin-sectioned and examined by optical microscopy to investigate the stages of the conversion from feed to glass. Various phenomena were seen, such as frit softening, bubble formation, foaming, bubble motion and removal, convective mixing, and homogenization. Behavior of different feeds was similar, although the degree of gas generation and melt homogenization varied.

  15. Waste glass melting stages

    SciTech Connect

    Anderson, L.D.; Dennis, T.; Elliott, M.L.; Hrma, P.

    1993-04-01

    Three different simulated nuclear waste glass feeds, consisting of dried waste and glass frit, were heat treated for 1 hour in a gradient furnace at temperatures ranging from approximately 600{degrees}C--1000{degrees}C. Simulated melter feeds from the Hanford Waste Vitrification Plant (HWVP), the Defense Waste Processing Facility (DWPF), and Kernforschungszentrum Karlsruhe (KfK) in Germany were used. The samples were thin-sectioned and examined by optical microscopy to investigate the stages of the conversion from feed to glass. Various phenomena were seen, such as frit softening, bubble formation, foaming, bubble motion and removal, convective mixing, and homogenization. Behavior of different feeds was similar, although the degree of gas generation and melt homogenization varied.

  16. Coset construction of AdS particle dynamics

    NASA Astrophysics Data System (ADS)

    Heinze, Martin; Jorjadze, George; Megrelidze, Luka

    2017-01-01

    We analyze the dynamics of the AdSN+1 particle realized on the coset SO(2, N)/SO (1,N). Hamiltonian reduction provides the physical phase space in terms of the coadjoint orbit obtained by boosting a timelike element of 𝔰𝔬(2, N). We show equivalence of this approach to geometric quantization and to the SO(N) covariant oscillator description, for which the boost generators entail a complicated operator ordering. As an alternative scheme, we introduce dual oscillator variables and derive their algebra at the classical and the quantum levels. This simplifies the calculations of the commutators for the boost generators and leads to unitary irreducible representations of 𝔰𝔬(2, N) for all admissible values of the mass parameter. We furthermore discuss an SO(N) covariant supersymmetric extension of the oscillator quantization, with its realization for superparticles in AdS2 and AdS3 given by recent works.

  17. Entanglement temperature and perturbed AdS3 geometry

    NASA Astrophysics Data System (ADS)

    Levine, G. C.; Caravan, B.

    2016-06-01

    Generalizing the first law of thermodynamics, the increase in entropy density δ S (x ) of a conformal field theory (CFT) is proportional to the increase in energy density, δ E (x ) , of a subsystem divided by a spatially dependent entanglement temperature, TE(x ) , a fixed parameter determined by the geometry of the subsystem, crossing over to thermodynamic temperature at high temperatures. In this paper we derive a generalization of the thermodynamic Clausius relation, showing that deformations of the CFT by marginal operators are associated with spatial temperature variations, δ TE(x ) , and spatial energy correlations play the role of specific heat. Using AdS/CFT duality we develop a relationship between a perturbation in the local entanglement temperature of the CFT and the perturbation of the bulk AdS metric. In two dimensions, we demonstrate a method through which direct diagonalizations of the boundary quantum theory may be used to construct geometric perturbations of AdS3 .

  18. AdS5 backgrounds with 24 supersymmetries

    NASA Astrophysics Data System (ADS)

    Beck, S.; Gutowski, J.; Papadopoulos, G.

    2016-06-01

    We prove a non-existence theorem for smooth AdS 5 solutions with connected, compact without boundary internal space that preserve strictly 24 supersymmetries. In particular, we show that D = 11 supergravity does not admit such solutions, and that all such solutions of IIB supergravity are locally isometric to the AdS 5 × S 5 maximally supersymmetric background. Furthermore, we prove that (massive) IIA supergravity also does not admit such solutions, provided that the homogeneity conjecture for massive IIA supergravity is valid. In the context of AdS/CFT these results imply that if gravitational duals for strictly mathcal{N}=3 superconformal theories in 4-dimensions exist, they are either singular or their internal spaces are not compact.

  19. Crystallization of fluorozirconate glasses

    NASA Technical Reports Server (NTRS)

    Bansal, Narottam P.; Doremus, Robert H.; Bruce, A. J.; Moynihan, C. T.

    1984-01-01

    The crystallization of a number of glasses of the fluorozirconate family has been studied (using powder X-ray diffraction and DSC) as a function of time and temperature of heating. The main crystalline phases were beta BaZrF6 and beta BaZr2F10. Stable and metastble transformations to the low-temperature alpha phases were also investigated. The size of crystallites in fully devitrified glasses was calculated (from line broadening of the X-ray diffraction peaks) to be about 60 nm.

  20. Glass-reinforced hydroxyapatite: a comprehensive study of the effect of glass composition on the crystallography of the composite.

    PubMed

    Lopes, M A; Santos, J D; Monteiro, F J; Knowles, J C

    1998-02-01

    Glass-reinforced HA composites were produced using phosphate-based glasses, and a structure refinement was carried out to determine the effect of the glass on the structure of the residual HA. Quantitative phase analysis showed that the glass causes some of the HA to decompose to beta-TCP and, at higher temperatures, to alpha-TCP. It also was indicated that when three phases were present, the formation of the alpha-TCP arose from decomposition of the beta-TCP and not from further decomposition of HA to alpha-TCP. The unit cell dimensions showed a decrease in the a axis and an increase in the c axis, giving an overall unit cell decrease in volume. There also was a significant effect based on the amount of glass added. The changes found in the composite containing the 4 wt% glass were attributed to the loss of carbonate and loss of hydroxyl. This was expected to cause shrinkage in the unit cell; however this was not seen, and therefore the major changes in the unit cell were attributed to the ions from the glass taking an interstitial role in the HA structure, thus not allowing the unit cell to shrink as much as expected.

  1. Degradation of glass artifacts: application of modern surface analytical techniques.

    PubMed

    Melcher, Michael; Wiesinger, Rita; Schreiner, Manfred

    2010-06-15

    attack on glass ("weathering") is much more complex due to the multiphase system (atmosphere, water film, glass surface, and bulk glass) and added complexities (such as relative humidity and atmospheric pollutant concentration). Weathered medieval stained glass objects, as well as artifacts under controlled museum conditions, typically have less transparent or translucent surfaces, often with a thick weathering crust on top, consisting of sulfates of the glass constituents K, Ca, Na, or Mg. In this Account, we try to answer questions about glass analysis and weathering in three main categories. (i) Which chemical reactions are involved in the weathering of glass surfaces? (ii) Which internal factors (such as the glass composition or surface properties) play a dominant role for the weathering process? Can certain environmental or climatic factors be identified as more harmful for glasses than others? Is it possible to set up a quantitative relationship or at least an approximation between the degree of weathering and the factors described above? (iii) What are the consequences for the restoration and conservation strategies of endangered glass objects? How can a severe threat to precious glass objects be avoided, or at least minimized, to preserve these artifacts of our cultural heritage for future generations?

  2. Lorentzian AdS geometries, wormholes, and holography

    SciTech Connect

    Arias, Raul E.; Silva, Guillermo A.; Botta Cantcheff, Marcelo

    2011-03-15

    We investigate the structure of two-point functions for the quantum field theory dual to an asymptotically Lorentzian Anti de Sitter (AdS) wormhole. The bulk geometry is a solution of five-dimensional second-order Einstein-Gauss-Bonnet gravity and causally connects two asymptotically AdS spacetimes. We revisit the Gubser-Klebanov-Polyakov-Witten prescription for computing two-point correlation functions for dual quantum field theories operators O in Lorentzian signature and we propose to express the bulk fields in terms of the independent boundary values {phi}{sub 0}{sup {+-}} at each of the two asymptotic AdS regions; along the way we exhibit how the ambiguity of normalizable modes in the bulk, related to initial and final states, show up in the computations. The independent boundary values are interpreted as sources for dual operators O{sup {+-}} and we argue that, apart from the possibility of entanglement, there exists a coupling between the degrees of freedom living at each boundary. The AdS{sub 1+1} geometry is also discussed in view of its similar boundary structure. Based on the analysis, we propose a very simple geometric criterion to distinguish coupling from entanglement effects among two sets of degrees of freedom associated with each of the disconnected parts of the boundary.

  3. Use of natural raw material for the production of photochromic glasses

    SciTech Connect

    Kiyan, V.I.; Artamonova, M.V.; Solinov, V.F.

    1986-07-01

    The authors investigated the possibility of using natural raw materials as replacements for soda and alumina for obtaining photochromic glasses and to determine their properties. Glasses of the sodium aluminoborosilicate system were studied. The characteristics of the batches and some of the properties of the glasses are given in a table. Sodium oxide was added to batches Nos. 1 and 2 as soda or borax. Composition Nos. 3, 4, and 5 were prepared using acid, basic, and neutral rocks by means of which the oxides of sodium and aluminum were added. The glasses were synthesized in SiC-heater furnaces. The differential thermal analysis of compositions Nos. 1 and 5 showed that the presence of natural materials leads to the formation of a liquid phase at lower temperatures which helps to intensify the processes of silicate- and glass-formation.

  4. Containerless processing of fluoride glass

    NASA Technical Reports Server (NTRS)

    Doremus, Robert H.

    1990-01-01

    Ground-based experiments on glass formation, crystallization, surface tension, vaporization, and chemical durability of a zirconium-barium-lanthanum (ZBL) fluoride glass are summarized. In a container large, columnar grains grew out from the container-glass interface during cooling. The main crystalline phase was alpha BaZrF6. A ZBL glass sphere was levitated acoustically during Shuttle flight STS-11. The glass was melted and then cooled while being levitated (containerless). Crystallization in the recovered sample was very fine and mainly beta BaZr2F10, showing the influence of the container on the nucleation and microstructure of crystallization in the glass. Glass formation should be easier for a containerless glass than in a container.

  5. Characterizing glass frits for slurries

    NASA Technical Reports Server (NTRS)

    Nakano, H. N.

    1979-01-01

    Glass frit can be mixed with consistently reproducible properties even from different batches of glass frit using technique to measure one quantity that determines integrated properties of frit for combination with given liquid.

  6. Barstow heliostat mirror glass characterization

    NASA Astrophysics Data System (ADS)

    Lind, M. A.; Buckwalter, C. Q.

    1980-09-01

    The technical analysis performed on the special run of low iron float glass for a ten megawatt solar thermal/electric pilot power plant is discussed. The topics that are addressed include the optical properties and the relative durability of the glass. Two optical parameters, solar transmittance and optical flatness, were measured as referenced in the specification and found to be better than the stated tolerances. The average solar transmittance exceeded 0.890 transmittance units. The glass also exhibited optical angular flatness deviations less than + or - 1.0 mrad as required. Both qualitative and quantitative accelerated weathering tests were performed on the glass in order to compare its durability to other soda lime float glass and alternate composition glasses of interest to the solar community. In both the quantitative leaching experiments and the more qualitative room temperature and elevated temperature water vapor exposure experiments the heliostat glass exhibited the same characteristics as the other soda lime silicate float glasses.

  7. Advanced Doubling Adding Method for Radiative Transfer in Planetary Atmospheres

    NASA Astrophysics Data System (ADS)

    Liu, Quanhua; Weng, Fuzhong

    2006-12-01

    The doubling adding method (DA) is one of the most accurate tools for detailed multiple-scattering calculations. The principle of the method goes back to the nineteenth century in a problem dealing with reflection and transmission by glass plates. Since then the doubling adding method has been widely used as a reference tool for other radiative transfer models. The method has never been used in operational applications owing to tremendous demand on computational resources from the model. This study derives an analytical expression replacing the most complicated thermal source terms in the doubling adding method. The new development is called the advanced doubling adding (ADA) method. Thanks also to the efficiency of matrix and vector manipulations in FORTRAN 90/95, the advanced doubling adding method is about 60 times faster than the doubling adding method. The radiance (i.e., forward) computation code of ADA is easily translated into tangent linear and adjoint codes for radiance gradient calculations. The simplicity in forward and Jacobian computation codes is very useful for operational applications and for the consistency between the forward and adjoint calculations in satellite data assimilation.

  8. Making Highly Pure Glass Rods

    NASA Technical Reports Server (NTRS)

    Naumann, R. J.

    1986-01-01

    Proposed quasi-containerless method for making glass rods or fibers minimizes contact between processing equipment and product. Method allows greater range of product sizes and shapes than achieved in experiments on containerless processing. Molten zone established in polycrystalline rod. Furnace sections separated, and glass rod solidifies between them. Clamp supports solid glass as it grows in length. Pulling clamp rapidly away from melt draws glass fiber. Fiber diameter controlled by adjustment of pulling rate.

  9. CADMIUM PHOSPHATE GLASS

    DOEpatents

    Carpenter, H.W.; Johnson, P.D.

    1963-04-01

    A method of preparing a cadmium phosphate glass that comprises providing a mixture of solid inorganic compounds of cadmuim and phosphate having vaporizable components and heating the resulting composition to a temperature of at least 850 un. Concent 85% C is presented. (AEC)

  10. "Stained Glass" Landscape Windows

    ERIC Educational Resources Information Center

    Vannata, Janine

    2008-01-01

    Both adults and children alike marvel at the grand vivid stained-glass windows created by American artist Louis Comfort Tiffany. Today he is commonly recognized as one of America's most influential designers and artists throughout the last nineteenth and early twentieth century. In the lesson described in this article, students created their own…

  11. Shimmering Stained Glass.

    ERIC Educational Resources Information Center

    Simon, Gail Murray

    1998-01-01

    Presents an art lesson for fifth- and sixth-graders where they create a translucent design of colored cellophane on black paper inspired by the stained-glass windows of the Middle Ages and the artwork of Lewis Comfort Tiffany. Enables the students to become crafts people rather than just observers of the past. (CMK)

  12. Stained-Glass Pastels

    ERIC Educational Resources Information Center

    Laird, Shirley

    2009-01-01

    The author has always liked the look of stained-glass windows. Usually the designs are simplified and the shapes are easier for younger students to draw. This technique seemed to be the perfect place for her fifth-graders to try their hand at color mixing. The smaller spaces and simple shapes were just what she needed for this group. Her students…

  13. Yesterday's Trash Makes Tomorrow's "Glass"

    ERIC Educational Resources Information Center

    Wayne, Dale

    2010-01-01

    In this article, the author describes a glass art project inspired by Dale Chihuly. This project uses two-liter plastic soda bottles which are cut apart and trimmed. Applying heat using a hair dryer, the plastic curls and takes an uneven blown-glass quality. The "glass" is then painted using acrylic paint. (Contains 2 resources and 1 online…

  14. Barstow heliostat mirror glass characterization

    SciTech Connect

    Lind, M.A.; Buckwalter, C.Q.

    1980-09-01

    The technical analysis performed on the special run of low iron float glass procured from the Ford Glass Division for the ten megawatt solar thermal/electric pilot power plant to be constructed at Barstow, California is discussed. The topics that are addressed include the optical properties and the relative durability of the glass. Two optical parameters, solar transmittance and optical flatness, were measured as referenced in the specification and found to be better than the stated tolerances. The average solar transmittance exceeded 0.890 transmittance units. The glass also exhibited optical angular flatness deviations less than +-1.0 mrad as required. Both qualitative and quantitative accelerated weathering tests were performed on the glass in order to compare its durability to other soda lime float glass and alternate composition glasses of interest to the solar community. In both the quantitative leaching experiments and the more qualitative room temperature and elevated temperature water vapor exposure experiments the heliostat glass exhibited the same characteristics as the other soda-lime silicate float glasses. As a final test for mirroring compatability, selected samples of the production run of the glass were sent to four different commercial manufacturers for mirror coating. None of the manufacturers reported any difficulty silvering the glass. Based on the tests performed, the glass meets or exceeds all optical specifications for the Barstow heliostat field.

  15. A deformation of AdS5 × S5

    NASA Astrophysics Data System (ADS)

    Gauntlett, Jerome P.; Gutowski, Jan B.; Suryanarayana, Nemani V.

    2004-11-01

    We analyse a one-parameter family of supersymmetric solutions of type IIB supergravity that includes AdS5 × S5. For small values of the parameter the solutions are causally well behaved, but beyond a critical value closed timelike curves (CTCs) appear. The solutions are holographically dual to {\\cal N}=4 supersymmetric Yang Mills theory on a non-conformally flat background with non-vanishing R-currents. We compute the holographic energy momentum tensor for the spacetime and show that it remains finite even when the CTCs appear. The solutions, as well as the uplift of some recently discovered AdS5 black-hole solutions, are shown to preserve precisely two supersymmetries.

  16. Supersymmetric AdS_6 solutions of type IIB supergravity

    NASA Astrophysics Data System (ADS)

    Kim, Hyojoong; Kim, Nakwoo; Suh, Minwoo

    2015-10-01

    We study the general requirement for supersymmetric AdS_6 solutions in type IIB supergravity. We employ the Killing spinor technique and study the differential and algebraic relations among various Killing spinor bilinears to find the canonical form of the solutions. Our result agrees precisely with the work of Apruzzi et al. (JHEP 1411:099, 2014), which used the pure spinor technique. Hoping to identify the geometry of the problem, we also computed four-dimensional theory through the dimensional reduction of type IIB supergravity on AdS_6. This effective action is essentially a non-linear sigma model with five scalar fields parametrizing {SL}(3,{R})/{SO}(2,1), modified by a scalar potential and coupled to Einstein gravity in Euclidean signature. We argue that the scalar potential can be explained by a subgroup CSO(1,1,1) subset {SL}(3,{R}) in a way analogous to gauged supergravity.

  17. Universal isolation in the AdS landscape

    NASA Astrophysics Data System (ADS)

    Danielsson, U. H.; Dibitetto, G.; Vargas, S. C.

    2016-12-01

    We study the universal conditions for quantum nonperturbative stability against bubble nucleation for pertubatively stable AdS vacua based on positive energy theorems. We also compare our analysis with the preexisting ones in the literature carried out within the thin-wall approximation. The aforementioned criterion is then tested in two explicit examples describing massive type IIA string theory compactified on S3 and S3×S3, respectively. The AdS landscape of both classes of compactifications is known to consist of a set of isolated points. The main result is that all critical points respecting the Breitenlohner-Freedman (BF) bound also turn out be stable at a nonperturbative level. Finally, we speculate on the possible universal features that may be extracted from the above specific examples.

  18. Tachyon inflation in an AdS braneworld with backreaction

    NASA Astrophysics Data System (ADS)

    Bilić, Neven; Dimitrijevic, Dragoljub D.; Djordjevic, Goran S.; Milosevic, Milan

    2017-02-01

    We analyze the inflationary scenario based on the tachyon field coupled with the radion of the second Randall-Sundrum model (RSII). The tachyon Lagrangian is derived from the dynamics of a 3-brane moving in the five-dimensional bulk. The AdS5 geometry of the bulk is extended to include the radion. Using the Hamiltonian formalism we find four nonlinear field equations supplemented by the modified Friedmann equations of the RSII braneworld cosmology. After a suitable rescaling we reduce the parameters of our model to only one free parameter related to the brane tension and the AdS5 curvature. We solve the equations numerically assuming a reasonably wide range of initial conditions determined by physical considerations. Varying the free parameter and initial conditions we confront our results with the Planck 2015 data.

  19. Ambitwistors, oscillators and massless fields on AdS5

    NASA Astrophysics Data System (ADS)

    Uvarov, D. V.

    2016-11-01

    Positive energy unitary irreducible representations of SU (2 , 2) can be constructed with the aid of bosonic oscillators in (anti)fundamental representation of SU(2)L × SU(2)R that are closely related to Penrose twistors. Starting with the correspondence between the doubleton representations, homogeneous functions on projective twistor space and on-shell generalized Weyl curvature SL (2 , C) spinors and their low-spin counterparts, we study in the similar way the correspondence between the massless representations, homogeneous functions on ambitwistor space and, via the Penrose transform, with the gauge fields on Minkowski boundary of AdS5. The possibilities of reconstructing massless fields on AdS5 and some applications are also discussed.

  20. Generalised structures for N=1 AdS backgrounds

    NASA Astrophysics Data System (ADS)

    Coimbra, André; Strickland-Constable, Charles

    2016-11-01

    We expand upon a claim made in a recent paper [arXiv:1411.5721] that generic minimally supersymmetric AdS backgrounds of warped flux compactifications of Type II and M theory can be understood as satisfying a straightforward weak integrability condition in the language of {E}_{d(d)}× {R}+ generalised geometry. Namely, they are spaces admitting a generalised G-structure set by the Killing spinor and with constant singlet generalised intrinsic torsion.

  1. Volcanic glass as a natural analog for borosilicate waste glass

    SciTech Connect

    Morgenstein, M.E.; Shettel, D.L.

    1994-12-31

    Obsidian and basaltic glass are opposite end-members of natural volcanic glass compositions. Syngenetic and diagenetic tensile failure in basaltic glass (low silica glass) is pervasive and provides abundant alteration fronts deep into the glass structure. Perlitic fracturing in obsidian (high silica glass) limits the alteration zones to an {open_quotes}onion skin{close_quotes} geometry. Borosilicate waste glass behaves similarly to the natural analog of basaltic glass (sideromelane). During geologic time, established and tensile fracture networks form glass cells (a three-dimensional reticulated pattern) where the production of new fracture surfaces increases through time by geometric progression. This suggests that borosilicate glass monoliths will eventually become rubble. Rates of reaction appear to double for every 12C{degrees} of temperature increase. Published leach rates suggest that the entire inventory of certain radionuclides may be released during the 10,000 year regulatory time period. Steam alteration prior to liquid attack combined with pervasive deep tensile failure behavior may suggest that the glass waste form is not license defensible without a metallic- and/or ceramic-type composite barrier as an overpack.

  2. Monolithically integrated solid state laser and waveguide using spin-on glass

    DOEpatents

    Ashby, Carol I. H.; Hohimer, John P.; Neal, Daniel R.; Vawter, G. Allen

    1995-01-01

    A monolithically integrated photonic circuit combining a semiconductor source of excitation light with an optically active waveguide formed on the substrate. The optically active waveguide is preferably formed of a spin-on glass to which are added optically active materials which can enable lasing action, optical amplification, optical loss, or frequency conversion in the waveguide, depending upon the added material.

  3. On information loss in AdS3/CFT2

    DOE PAGES

    Fitzpatrick, A. Liam; Kaplan, Jared; Li, Daliang; ...

    2016-05-18

    We discuss information loss from black hole physics in AdS3, focusing on two sharp signatures infecting CFT2 correlators at large central charge c: ‘forbidden singularities’ arising from Euclidean-time periodicity due to the effective Hawking temperature, and late-time exponential decay in the Lorentzian region. We study an infinite class of examples where forbidden singularities can be resolved by non-perturbative effects at finite c, and we show that the resolution has certain universal features that also apply in the general case. Analytically continuing to the Lorentzian regime, we find that the non-perturbative effects that resolve forbidden singularities qualitatively change the behavior ofmore » correlators at times t ~SBH, the black hole entropy. This may resolve the exponential decay of correlators at late times in black hole backgrounds. By Borel resumming the 1/c expansion of exact examples, we explicitly identify ‘information-restoring’ effects from heavy states that should correspond to classical solutions in AdS3. Lastly, our results suggest a line of inquiry towards a more precise formulation of the gravitational path integral in AdS3.« less

  4. Shock Wave Collisions and Thermalization in AdS_5

    NASA Astrophysics Data System (ADS)

    Kovchegov, Y. V.

    We study heavy ion collisions at strong 't Hooft coupling usingAdS/CFT correspondence. According to the AdS/CFT dictionary heavy ion collisions correspond to gravitational shock wave collisions in AdS_5. We construct the metric in the forward light cone after the collision perturbatively through expansion of Einstein equations in graviton exchanges. We obtain an analytic expression for the metric including all-order graviton exchanges with one shock wave, while keeping the exchanges with another shock wave at the lowest order. We read off the corresponding energy-momentum tensor of the produced medium. Unfortunately this energy-momentum tensor does not correspond to ideal hydrodynamics, indicating that higher order graviton exchanges are needed to construct the full solution of the problem. We also show that shock waves must completely stop almost immediately after the collision in AdS_5, which, on the field theory side, corresponds to complete nuclear stopping due to strong coupling effects, likely leading to Landau hydrodynamics. Finally, we perform trapped surface analysis of the shock wave collisions demonstrating that a bulk black hole, corresponding to ideal hydrodynamics on the boundary, has to be created in such collisions, thus constructing a proof of thermalization in heavy ion collisions at strong coupling.

  5. Potential utilization of glass experiments in space

    NASA Technical Reports Server (NTRS)

    Kreidl, N. J.

    1984-01-01

    Materials processing in space utilizing the microgravity environment is discussed; glass processing in particular is considered. Attention is given to the processing of glass shells, critical cooling rate and novel glasses, gel synthesis of glasses, immiscibility, surface tension, and glass composites. Soviet glass experiments in space are also enumerated.

  6. Effect of CaF{sub 2} addition on optical properties of barium phosphate glasses

    SciTech Connect

    Kumar, N. Manoj Rao, G. Venkateswara Akhila, B. E. Shashikala, H. D.

    2014-04-24

    Ternary barium phosphate glasses, (50−X)BaO−XCaF{sub 2}−50P{sub 2}O{sub 5} have been prepared by adding 0-10 mol% of CaF{sub 2} to binary barium phosphate glasses. The amorphous nature of the prepared glasses was confirmed by X-ray diffraction technique. The UV-Visible absorption spectra have been recorded, optical band gap energy Eopt and Urbach energy Etail were determined. Shift in Eopt and Etail with increase in concentration of CaF{sub 2} is noted. FTIR analysis was carried out to investigate the short and intermediate-range orders in glasses. Shift of (P-O-P) band to higher wave number with the substitution of BaO with CaF{sub 2} shows the shortening of the phosphate chains. Hardness and density of glass samples were measured and correlated with the composition of glasses.

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

    PubMed

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

    2017-05-01

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

  8. Properties of crystalline phase in waste glass

    SciTech Connect

    Usami, T.; Uruga, K.; Tsukada, T.; Miura, Y.; Komamine, S.; Ochi, E.

    2013-07-01

    Depending on the operating conditions of the vitrification process of high-level liquid waste, some crystalline phases can be present. The crystalline phase exists as molten salt at glass melting temperature. In this study, the chemical and physical properties of the crystalline phase were determined. Two samples rich in Mo and a sample rich in Re were examined. One of the samples rich in Mo was obtained from simulated waste solution and glass beads in a middle scale melter, while two other samples were made from mixed reagents. The chemical forms of the constituents were determined by XRD and SEM-EDX. When Mo is dominant, the crystal is mainly composed of molybdates of Na, Li, Ba and Ca, Na{sub 2}SO{sub 4} and CsReO{sub 4}. When Re is dominant, (Na{sub x}Cs{sub 1-x})ReO{sub 4} and NaLiMoO{sub 4} are added. The characteristic temperature and the heat of transition were determined by differential scanning calorimetry. The density of the molten salt at high temperature was measured from buoyancy. The density of the molten salt is larger than that of molten glass, and increases with Re content. (authors)

  9. The generalized added mass revised

    NASA Astrophysics Data System (ADS)

    De Wilde, Juray

    2007-05-01

    The reformulation of the generalized or apparent added mass presented by De Wilde [Phys. Fluids 17, 113304 (2005)] neglects the presence of a drag-type force in the gas and solid phase momentum equations. Reformulating the generalized added mass accounting for the presence of a drag-type force, an apparent drag force appears next to the apparent distribution of the filtered gas phase pressure gradient over the phases already found by De Wilde in the above-cited reference. The reformulation of the generalized added mass and the evaluation of a linear wave propagation speed test then suggest a generalized added mass type closure approach to completely describe filtered gas-solid momentum transfer, that is, including both the filtered drag force and the correlation between the solid volume fraction and the gas phase pressure gradient.

  10. HIGH ALUMINUM HLW GLASSES FOR HANFORDS WTP

    SciTech Connect

    KRUGER AA; JOSEPH I; BOWMAN BW; GAN H; KOT W; MATLACK KS; PEGG IL

    2009-08-19

    the achievements of this program with emphasis on the recent enhancements in Al{sub 2}O{sub 3} loadings in HLW glass and its processing characteristics. Glass formulation development included crucible-scale preparation and characterization of glass samples to assess compliance with all melt processing and product quality requirements, followed by small-scale screening tests to estimate processing rates. These results were used to down-select formulations for subsequent engineering-scale melter testing. Finally, further testing was performed on the DM1200 vitrification system installed at VSL, which is a one-third scale (1.20 m{sup 2}) pilot melter for the WTP HLW melters and which is fitted with a fully prototypical off-gas treatment system. These tests employed glass formulations with high waste loadings and Al{sub 2}O{sub 3} contents of {approx}25 wt%, which represents a near-doubling of the present WTP baseline maximum Al{sub 2}O{sub 3} loading. In addition, these formulations were processed successfully at glass production rates that exceeded the present requirements for WTP HLW vitrification by up to 88%. The higher aluminum loading in the HLW glass has an added benefit in that the aluminum leaching requirements in pretreatment are reduced, thus allowing less sodium addition in pretreatment, which in turn reduces the amount of LAW glass to be produced at the WTP. The impact of the results from this ORP program in reducing the overall cost and schedule for the Hanford waste treatment mission will be discussed.

  11. Profiles in garbage glass containers

    SciTech Connect

    Miller, C.

    1997-09-01

    Glass containers are made from sand, limestone, soda ash, cullet (crushed bottles), and various additives, including those used to color brown, green, or blue bottles. Sixty percent of the glass used in the US is clear (flint) and one-fourth is brown (amber). Almost half of the green bottles are imported wind and beer bottles. Other glass products include flat glass such as windows; fiberglass insulation; and glassware. These products use different manufacturing processes and different additives than container glass. This profile covers only container glass. Glass bottles are commonly collected in curb-side programs. Losses due to breakage and the abrasiveness of glass during collection and processing offset their low collection and processing costs. Breakage solutions include installation of interior baffles or nets in the collection trucks, special glass-only truck compartments, and limiting the number of times glass is transferred after collection before final processing. Ten states require deposits on glass bottles for beer and soft drinks and related items.

  12. Fluoride glass: Crystallization, surface tension

    NASA Technical Reports Server (NTRS)

    Doremus, R. H.

    1988-01-01

    Fluoride glass was levitated acoustically in the ACES apparatus on STS-11, and the recovered sample had a different microstructure from samples cooled in a container. Further experiments on levitated samples of fluoride glass are proposed. These include nucleation, crystallization, melting observations, measurement of surface tension of molten glass, and observation of bubbles in the glass. Ground experiments are required on sample preparation, outgassing, and surface reactions. The results should help in the development and evaluation of containerless processing, especially of glass, in the development of a contaminent-free method of measuring surface tensions of melts, in extending knowledge of gas and bubble behavior in fluoride glasses, and in increasing insight into the processing and properties of fluoride glasses.

  13. AD-1 aircraft in flight

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The Ames-Dryden (AD)-1 was a research aircraft designed to investigate the concept of an oblique (or pivoting) wing. The movie clip runs about 17 seconds and has two air-to-air views of the AD-1. The first shot is from slightly above as the wing pivots to 60 degrees. The other angle is almost directly below the aircraft when the wing is fully pivoted.

  14. Immobilization of radioactive iodine in silver aluminophosphate glasses.

    PubMed

    Lemesle, Thomas; Méar, François O; Campayo, Lionel; Pinet, Olivier; Revel, Bertrand; Montagne, Lionel

    2014-01-15

    Silver aluminophosphate glasses have been investigated as matrices for the immobilization of radioactive iodine. In this study, up to 28mol% AgI have been incorporated without volatilization thanks to a low temperature synthesis protocol. Alumina was added in the composition in order to increase the glass transition temperature for a better thermal stability in a repository conditions. Two series of glasses have been investigated, based on AgPO3 and Ag5P3O10 compositions, and with 0-5mol% Al2O3. We report (31)P, (27)Al and (109)Ag NMR study of these glasses, including advanced measurement of the connectivities through {(27)Al}-(31)P cross-polarization and (31)P-(31)P double-quantum correlation. We confirm that AgI is inserted in the aluminophosphate glasses and does not form clusters. AgI does not induce any modification of the glass polymerization but only an expansion of the network. Despite no evidence for crystallization could be obtained from XRD, NMR revealed that the introduction of AgI induces an exclusion of alumina from the network, leading to the crystallization of aluminophosphate phases such as Al(PO3)3 or AlPO4. As a consequence, despite NMR gives evidence for the presence of aluminophosphate bonds, only a limited effect of alumina addition on thermal properties is observed.

  15. Production of glass or glass-ceramic to metal seals with the application of pressure

    DOEpatents

    Kelly, M.D.; Kramer, D.P.

    1985-01-04

    In a process for preparing a glass or glass-ceramic to metal seal comprising contacting the glass with the metal and heat-treating the glass and metal under conditions whereby the glass to metal seal is effected and, optionally, the glass is converted to a glass-ceramic, an improvement comprises carrying out the heat-treating step using hot isostatic pressing.

  16. Production of glass or glass-ceramic to metal seals with the application of pressure

    DOEpatents

    Kelly, Michael D.; Kramer, Daniel P.

    1987-11-10

    In a process for preparing a glass or glass-ceramic to metal seal comprising contacting the glass with the metal and heat-treating the glass and metal under conditions whereby the glass to metal seal is effected and, optionally, the glass is converted to a glass-ceramic, an improvement comprises carrying out the heat-treating step using hot isostatic pressing.

  17. Spin Glass Patch Planting

    NASA Technical Reports Server (NTRS)

    Wang, Wenlong; Mandra, Salvatore; Katzgraber, Helmut G.

    2016-01-01

    In this paper, we propose a patch planting method for creating arbitrarily large spin glass instances with known ground states. The scaling of the computational complexity of these instances with various block numbers and sizes is investigated and compared with random instances using population annealing Monte Carlo and the quantum annealing DW2X machine. The method can be useful for benchmarking tests for future generation quantum annealing machines, classical and quantum mechanical optimization algorithms.

  18. Polyamorphism in metalic glass.

    SciTech Connect

    Sheng, H. W.; Liu, H. Z.; Cheng, Y. Q.; Wen, J.; Lee, P.L.; Luo, W.K.; Shastri, S.D.; Ma, E.; X-Ray Science Division; Johns Hopkins Univ.; Chinese Academy of Sciences

    2007-03-01

    A metal, or an alloy, can often exist in more than one crystal structure. The face-centered-cubic and body-centered-cubic forms of iron (or steel) are a familiar example of such polymorphism. When metallic materials are made in the amorphous form, is a parallel 'polyamorphism' possible? So far, polyamorphic phase transitions in the glassy state have been observed only in glasses involving directional and open (such as tetrahedral) coordination environments. Here, we report an in situ X-ray diffraction observation of a pressure-induced transition between two distinct amorphous polymorphs in a Ce{sub 55}Al{sub 45} metallic glass. The large density difference observed between the two polyamorphs is attributed to their different electronic and atomic structures, in particular the bond shortening revealed by ab initio modeling of the effects of f-electron delocalization. This discovery offers a new perspective of the amorphous state of metals, and has implications for understanding the structure, evolution and properties of metallic glasses and related liquids. Our work also opens a new avenue towards technologically useful amorphous alloys that are compositionally identical but with different thermodynamic, functional and rheological properties due to different bonding and structural characteristics.

  19. Picritic glasses from Hawaii

    USGS Publications Warehouse

    Clague, D.A.; Weber, W.S.; Dixon, J.E.

    1991-01-01

    ESTIMATES of the MgO content of primary Hawaiian tholeiitic melts range from 8wt% to as high as 25wt% (refs 1, 2). In general, these estimates are derived from analysis of the whole-rock composition of lavas, coupled with the compositions of the most magnesian olivine phenocrysts observed. But the best estimate of magma composition comes from volcanic glass, as it represents the liquid composition at the time of quenching; minimal changes occur during the quenching process. Here we report the discovery of tholeiitic basalt glasses, recovered offshore of Kilauea volcano, that contain up to 15.0 wt% MgO. To our knowledge, these are the most magnesian glasses, and have the highest eruption temperatures (??? 1,316 ??C), yet found. The existence of these picritic (high-MgO) liquids provides constraints on the temperature structure of the upper mantle, magma transport and the material and thermal budgets of the Hawaiian volcanoes. Furthermore, picritic melts are affected little by magma-reservoir processes, and it is therefore relatively straightforward to extrapolate back to the composition of the primary melt and its volatile contents.

  20. Trapping and wiggling: elastohydrodynamics of driven microfilaments.

    PubMed Central

    Wiggins, C H; Riveline, D; Ott, A; Goldstein, R E

    1998-01-01

    We present an analysis of the planar motion of single semiflexible filaments subject to viscous drag or point forcing. These are the relevant forces in dynamic experiments designed to measure biopolymer bending moduli. By analogy with the "Stokes problems" in hydrodynamics (motion of a viscous fluid induced by that of a wall bounding the fluid), we consider the motion of a polymer, one end of which is moved in an impulsive or oscillatory way. Analytical solutions for the time-dependent shapes of such moving polymers are obtained within an analysis applicable to small-amplitude deformations. In the case of oscillatory driving, particular attention is paid to a characteristic length determined by the frequency of oscillation, the polymer persistence length, and the viscous drag coefficient. Experiments on actin filaments manipulated with optical traps confirm the scaling law predicted by the analysis and provide a new technique for measuring the elastic bending modulus. Exploiting this model, we also present a reanalysis of several published experiments on microtubules. PMID:9533717

  1. Trapping and wiggling: elastohydrodynamics of driven microfilaments.

    PubMed

    Wiggins, C H; Riveline, D; Ott, A; Goldstein, R E

    1998-02-01

    We present an analysis of the planar motion of single semiflexible filaments subject to viscous drag or point forcing. These are the relevant forces in dynamic experiments designed to measure biopolymer bending moduli. By analogy with the "Stokes problems" in hydrodynamics (motion of a viscous fluid induced by that of a wall bounding the fluid), we consider the motion of a polymer, one end of which is moved in an impulsive or oscillatory way. Analytical solutions for the time-dependent shapes of such moving polymers are obtained within an analysis applicable to small-amplitude deformations. In the case of oscillatory driving, particular attention is paid to a characteristic length determined by the frequency of oscillation, the polymer persistence length, and the viscous drag coefficient. Experiments on actin filaments manipulated with optical traps confirm the scaling law predicted by the analysis and provide a new technique for measuring the elastic bending modulus. Exploiting this model, we also present a reanalysis of several published experiments on microtubules.

  2. IMPACT OF URANIUM AND THORIUM ON HIGH TIO2 CONCENTRATION NUCLEAR WASTE GLASSES

    SciTech Connect

    Fox, K.; Edwards, T.

    2012-01-11

    This study focused on the potential impacts of the addition of Crystalline Silicotitanate (CST) and Monosodium Titanate (MST) from the Small Column Ion Exchange (SCIX) process on the Defense Waste Processing Facility (DWPF) glass waste form and the applicability of the DWPF process control models. MST from the Salt Waste Processing Facility (SWPF) is also considered in the study. The KT08-series of glasses was designed to evaluate any impacts of the inclusion of uranium and thorium in glasses containing the SCIX components. All but one of the study glasses were found to be amorphous by X-ray diffraction (XRD). One of the slowly cooled glasses contained a small amount of trevorite, which is typically found in DWPF-type glasses and had no practical impact on the durability of the glass. The measured Product Consistency Test (PCT) responses for the study glasses and the viscosities of the glasses were well predicted by the current DWPF models. No unexpected issues were encountered when uranium and thorium were added to the glasses with SCIX components.

  3. Demonstration of sulfur solubility determinations in high waste loading, low-activity waste glasses

    SciTech Connect

    Fox, K. M.

    2016-04-25

    A method recommended by Pacific Northwest National Laboratory (PNNL) for sulfate solubility determinations in simulated low-activity waste glasses was demonstrated using three compositions from a recent Hanford high waste loading glass study. Sodium and sulfate concentrations in the glasses increased after each re-melting step. Visual observations of the glasses during the re-melting process reflected the changes in composition. The measured compositions showed that the glasses met the targeted values. The amount of SO3 retained in the glasses after washing was relatively high, ranging from 1.6 to 2.6 weight percent (wt %). Measured SnO2 concentrations were notably low in all of the study glasses. The composition of the wash solutions should be measured in future work to determine whether SnO2 is present with the excess sulfate washed from the glass. Increases in batch size and the amount of sodium sulfate added did not have a measureable impact on the amount of sulfate retained in the glass, although this was tested for only a single glass composition. A batch size of 250 g and a sodium sulfate addition targeting 7 wt %, as recommended by PNNL, will be used in future experiments.

  4. Euclidean and Noetherian entropies in AdS space

    SciTech Connect

    Dutta, Suvankar; Gopakumar, Rajesh

    2006-08-15

    We examine the Euclidean action approach, as well as that of Wald, to the entropy of black holes in asymptotically AdS spaces. From the point of view of holography these two approaches are somewhat complementary in spirit and it is not obvious why they should give the same answer in the presence of arbitrary higher derivative gravity corrections. For the case of the AdS{sub 5} Schwarzschild black hole, we explicitly study the leading correction to the Bekenstein-Hawking entropy in the presence of a variety of higher derivative corrections studied in the literature, including the Type IIB R{sup 4} term. We find a nontrivial agreement between the two approaches in every case. Finally, we give a general way of understanding the equivalence of these two approaches.

  5. Silicate release from glass for pharmaceutical preparations.

    PubMed

    Bohrer, Denise; Bortoluzzi, Fabiana; Nascimento, Paulo Cícero; Carvalho, Leandro Machado; Ramirez, Adrian Gustavo

    2008-05-01

    Glass is made of polymeric silica and other minor components, which are necessary for turning the silica into a material more easily moldable and resistant to temperature changes. Glass containers for pharmaceutical usage are classified according to their resistance to a chemical attack, a test carried out in the presence of water and heat. The test is designed to show the released alkalinity, a variable dependent on the amount of sodium oxide, one of the minor components added to the glass mass. In this work, the release of silica from glass by action of constituents from pharmaceutical formulations was investigated. The study included products used in large volumes and usually stored in glass containers. Solutions of amino acids, electrolytes, glucose, oligoelements and others such as heparin and sodium bicarbonate were individually stored in glass containers and heated at 121 degrees C for 30min, as in the water attack test. The test was also carried out only with water, where the pH varied from 2 to 12. The released silicate was measured either by photometry or atomic absorption spectrometry, depending on the nature of the sample. The results showed that silicate is released during the heating cycle even if the contact is with pure water only. The pH exerts a considerable influence on the release, being that the higher the pH, the higher the silica dissolved. An elevated pH, however, is not the only factor responsible for silica dissolution. While in the solutions of NaCl, KCl, Mg Cl2 and ZnSO4 and in most of the amino acids, the concentration of silicate was as high as in pure water (0.1-1.0mg Si/L). In the solutions of sodium acetate, bicarbonate and gluconate, its concentration was much higher, over 30mg Si/L. These results were confirmed by the analysis of commercial products, where in solutions of amino acids the level of silicate ranged from 0.14 to 0.19mg Si/L. On the other hand, calcium gluconate, sodium bicarbonate and potassium phosphate presented

  6. New Features in ADS Labs

    NASA Astrophysics Data System (ADS)

    Accomazzi, Alberto; Kurtz, M. J.; Henneken, E. A.; Grant, C. S.; Thompson, D.; Di Milia, G.; Luker, J.; Murray, S. S.

    2013-01-01

    The NASA Astrophysics Data System (ADS) has been working hard on updating its services and interfaces to better support our community's research needs. ADS Labs is a new interface built on the old tried-and-true ADS Abstract Databases, so all of ADS's content is available through it. In this presentation we highlight the new features that have been developed in ADS Labs over the last year: new recommendations, metrics, a citation tool and enhanced fulltext search. ADS Labs has long been providing article-level recommendations based on keyword similarity, co-readership and co-citation analysis of its corpus. We have now introduced personal recommendations, which provide a list of articles to be considered based on a individual user's readership history. A new metrics interface provides a summary of the basic impact indicators for a list of records. These include the total and normalized number of papers, citations, reads, and downloads. Also included are some of the popular indices such as the h, g and i10 index. The citation helper tool allows one to submit a set of records and obtain a list of top 10 papers which cite and/or are cited by papers in the original list (but which are not in it). The process closely resembles the network approach of establishing "friends of friends" via an analysis of the citation network. The full-text search service now covers more than 2.5 million documents, including all the major astronomy journals, as well as physics journals published by Springer, Elsevier, the American Physical Society, the American Geophysical Union, and all of the arXiv eprints. The full-text search interface interface allows users and librarians to dig deep and find words or phrases in the body of the indexed articles. ADS Labs is available at http://adslabs.org

  7. Heavy quark potential from deformed AdS5 models

    NASA Astrophysics Data System (ADS)

    Zhang, Zi-qiang; Hou, De-fu; Chen, Gang

    2017-04-01

    In this paper, we investigate the heavy quark potential in some holographic QCD models. The calculation relies on a modified renormalization scheme mentioned in a previous work of Albacete et al. After studying the heavy quark potential in Pirner-Galow model and Andreev-Zakharov model, we extend the discussion to a general deformed AdS5 case. It is shown that the obtained potential is negative definite for all quark-antiquark separations, differs from that using the usual renormalization scheme.

  8. The AdS central charge in string theory

    NASA Astrophysics Data System (ADS)

    Troost, Jan

    2011-11-01

    We evaluate the vacuum expectation value of the central charge operator in string theory in an AdS3 vacuum. Our calculation provides a rare non-zero one-point function on a spherical worldsheet. The evaluation involves the regularization both of a worldsheet ultraviolet divergence (associated to the infinite volume of the conformal Killing group), and a space-time infrared divergence (corresponding to the infinite volume of space-time). The two divergences conspire to give a finite result, which is the classical general relativity value for the central charge, corrected in bosonic string theory by an infinite series of tree level higher derivative terms.

  9. Internal structure of charged AdS black holes

    NASA Astrophysics Data System (ADS)

    Bhattacharjee, Srijit; Sarkar, Sudipta; Virmani, Amitabh

    2016-06-01

    When an electrically charged black hole is perturbed, its inner horizon becomes a singularity, often referred to as the Poisson-Israel mass inflation singularity. Ori constructed a model of this phenomenon for asymptotically flat black holes, in which the metric can be determined explicitly in the mass inflation region. In this paper we implement the Ori model for charged AdS black holes. We find that the mass function inflates faster than the flat space case as the inner horizon is approached. Nevertheless, the mass inflation singularity is still a weak singularity: Although spacetime curvature becomes infinite, tidal distortions remain finite on physical objects attempting to cross it.

  10. Mixed polyanion glass cathodes: Glass-state conversion reactions

    DOE PAGES

    Kercher, Andrew K.; Kolopus, James A.; Carroll, Kyler; ...

    2015-01-01

    Mixed polyanion (MP) glasses can undergo glass-state conversion (GSC) reactions to provide an alternate class of high-capacity cathode materials. GSC reactions have been demonstrated in phosphate/vanadate glasses with Ag, Co, Cu, Fe, and Ni cations. These MP glasses provided high capacity and good high power performance, but suffer from moderate voltages, large voltage hysteresis, and significant capacity fade with cycling. Details of the GSC reaction have been revealed by x-ray absorption spectroscopy, electron microscopy, and energy dispersive x-ray spectroscopy of ex situ cathodes at key states of charge. Using the Open Quantum Materials Database (OQMD), a computational thermodynamic model hasmore » been developed to predict the near-equilibrium voltages of glass-state conversion reactions in MP glasses.« less

  11. Laser Glass Frit Sealing for Encapsulation of Vacuum Insulation Glasses

    NASA Astrophysics Data System (ADS)

    Kind, H.; Gehlen, E.; Aden, M.; Olowinsky, A.; Gillner, A.

    Laser glass frit sealing is a joining method predestined in electronics for the sealing of engineered materials housings in dimensions of some 1 mm2 to several 10 mm2. The application field ranges from encapsulation of display panels to sensor housings. Laser glass frit sealing enables a hermetical closure excluding humidity and gas penetration. But the seam quality is also interesting for other applications requiring a hermetical sealing. One application is the encapsulation of vacuum insulation glass. The gap between two panes must be evacuated for reducing the thermal conductivity. Only an efficient encapsulating technique ensures durable tight joints of two panes for years. Laser glass frit sealing is an alternative joining method even though the material properties of soda lime glass like sensitivity to thermal stresses are much higher as known from engineered materials. An adapted thermal management of the process is necessary to prevent the thermal stresses within the pane to achieve crack free and tight glass frit seams.

  12. Mixed polyanion glass cathodes: Glass-state conversion reactions

    SciTech Connect

    Kercher, Andrew K.; Kolopus, James A.; Carroll, Kyler; Unocic, Raymond R.; Kirklin, S.; Wolverton, C.; Stooksbury, Shelby L.; Boatner, Lynn A.; Dudney, Nancy J.

    2015-01-01

    Mixed polyanion (MP) glasses can undergo glass-state conversion (GSC) reactions to provide an alternate class of high-capacity cathode materials. GSC reactions have been demonstrated in phosphate/vanadate glasses with Ag, Co, Cu, Fe, and Ni cations. These MP glasses provided high capacity and good high power performance, but suffer from moderate voltages, large voltage hysteresis, and significant capacity fade with cycling. Details of the GSC reaction have been revealed by x-ray absorption spectroscopy, electron microscopy, and energy dispersive x-ray spectroscopy of ex situ cathodes at key states of charge. Using the Open Quantum Materials Database (OQMD), a computational thermodynamic model has been developed to predict the near-equilibrium voltages of glass-state conversion reactions in MP glasses.

  13. Analytical Plan for Roman Glasses

    SciTech Connect

    Strachan, Denis M.; Buck, Edgar C.; Mueller, Karl T.; Schwantes, Jon M.; Olszta, Matthew J.; Thevuthasan, Suntharampillai; Heeren, Ronald M.

    2011-01-01

    Roman glasses that have been in the sea or underground for about 1800 years can serve as the independent “experiment” that is needed for validation of codes and models that are used in performance assessment. Two sets of Roman-era glasses have been obtained for this purpose. One set comes from the sunken vessel the Iulia Felix; the second from recently excavated glasses from a Roman villa in Aquileia, Italy. The specimens contain glass artifacts and attached sediment or soil. In the case of the Iulia Felix glasses quite a lot of analytical work has been completed at the University of Padova, but from an archaeological perspective. The glasses from Aquileia have not been so carefully analyzed, but they are similar to other Roman glasses. Both glass and sediment or soil need to be analyzed and are the subject of this analytical plan. The glasses need to be analyzed with the goal of validating the model used to describe glass dissolution. The sediment and soil need to be analyzed to determine the profile of elements released from the glass. This latter need represents a significant analytical challenge because of the trace quantities that need to be analyzed. Both pieces of information will yield important information useful in the validation of the glass dissolution model and the chemical transport code(s) used to determine the migration of elements once released from the glass. In this plan, we outline the analytical techniques that should be useful in obtaining the needed information and suggest a useful starting point for this analytical effort.

  14. Impact resistance of bar glasses.

    PubMed

    Shepherd, J P; Huggett, R H; Kidner, G

    1993-12-01

    Bar glasses are often used as weapons in interpersonal violence. Violence often erupts spontaneously and assailants use objects close to hand as weapons. After an initial national Accident and Emergency Department study to identify glass designs most often implicated in interpersonal violence, the impact resistance of 1-pint beer glasses was tested in a materials laboratory with a Zwick 5102 pendulum impact tester. Both straight-sided (nonik) glasses (annealed and tempered) and handled tankards (annealed) were tested to destruction. The impact resistance of new glasses was compared with that of glasses subjected to wear. The mean impact resistance of new annealed noniks did not differ significantly although new glasses were significantly more resistant than worn glasses (p < 0.01). It was not possible to break any of the tempered glasses with the pendulum used (maximum impact energy, 4 J). When noniks had been scratched at the rim to mimic wear, tempered glasses also had the highest impact resistance (p < 0.01) whereas the mean resistance of the annealed noniks was not significantly different. When tempered glasses failed during testing, they all disintegrated into relatively harmless cubes of glass, particularly the thicker bases of glasses. In contrast, annealed designs fractured leaving sharp shards although the thicker bases remained intact. The mean impact resistance of new annealed noniks was 0.5 J, of worn annealed noniks 0.08 J, of tempered new noniks > 4 J, of worn tempered noniks 0.18 J, and of tankards, 1.7 J.(ABSTRACT TRUNCATED AT 250 WORDS)

  15. Bioactive glass in tissue engineering

    PubMed Central

    Rahaman, Mohamed N.; Day, Delbert E.; Bal, B. Sonny; Fu, Qiang; Jung, Steven B.; Bonewald, Lynda F.; Tomsia, Antoni P.

    2011-01-01

    This review focuses on recent advances in the development and use of bioactive glass for tissue engineering applications. Despite its inherent brittleness, bioactive glass has several appealing characteristics as a scaffold material for bone tissue engineering. New bioactive glasses based on borate and borosilicate compositions have shown the ability to enhance new bone formation when compared to silicate bioactive glass. Borate-based bioactive glasses also have controllable degradation rates, so the degradation of the bioactive glass implant can be more closely matched to the rate of new bone formation. Bioactive glasses can be doped with trace quantities of elements such as Cu, Zn and Sr, which are known to be beneficial for healthy bone growth. In addition to the new bioactive glasses, recent advances in biomaterials processing have resulted in the creation of scaffold architectures with a range of mechanical properties suitable for the substitution of loaded as well as non-loaded bone. While bioactive glass has been extensively investigated for bone repair, there has been relatively little research on the application of bioactive glass to the repair of soft tissues. However, recent work has shown the ability of bioactive glass to promote angiogenesis, which is critical to numerous applications in tissue regeneration, such as neovascularization for bone regeneration and the healing of soft tissue wounds. Bioactive glass has also been shown to enhance neocartilage formation during in vitro culture of chondrocyte-seeded hydrogels, and to serve as a subchondral substrate for tissue-engineered osteochondral constructs. Methods used to manipulate the structure and performance of bioactive glass in these tissue engineering applications are analyzed. PMID:21421084

  16. Introducing ADS 2.0

    NASA Astrophysics Data System (ADS)

    Accomazzi, Alberto; Kurtz, M. J.; Henneken, E. A.; Grant, C. S.; Thompson, D.; Luker, J.; Chyla, R.; Murray, S. S.

    2014-01-01

    In the spring of 1993, the Smithsonian/NASA Astrophysics Data System (ADS) first launched its bibliographic search system. It was known then as the ADS Abstract Service, a component of the larger Astrophysics Data System effort which had developed an interoperable data system now seen as a precursor of the Virtual Observatory. As a result of the massive technological and sociological changes in the field of scholarly communication, the ADS is now completing the most ambitious technological upgrade in its twenty-year history. Code-named ADS 2.0, the new system features: an IT platform built on web and digital library standards; a new, extensible, industrial strength search engine; a public API with various access control capabilities; a set of applications supporting search, export, visualization, analysis; a collaborative, open source development model; and enhanced indexing of content which includes the full-text of astronomy and physics publications. The changes in the ADS platform affect all aspects of the system and its operations, including: the process through which data and metadata are harvested, curated and indexed; the interface and paradigm used for searching the database; and the follow-up analysis capabilities available to the users. This poster describes the choices behind the technical overhaul of the system, the technology stack used, and the opportunities which the upgrade is providing us with, namely gains in productivity and enhancements in our system capabilities.

  17. SON68 glass dissolution driven by magnesium silicate precipitation

    NASA Astrophysics Data System (ADS)

    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

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

    PubMed

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

    2013-01-01

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

  19. Mixed polyanion glass cathodes: Iron phosphate vanadate glasses

    SciTech Connect

    Kercher, Andrew K; Ramey, Joanne Oxendine; Carroll, Kyler J; Kiggans Jr, James O; Veith, Gabriel M; Meisner, Roberta; Boatner, Lynn A; Dudney, Nancy J

    2014-01-01

    Mixed polyanion (MP) glasses have been investigated for use as cathodes in lithium ion batteries. MP glass cathodes are similar in composition to theoretically promising crystalline polyanionic (CP) cathodes (e.g., lithium cobalt phosphate, lithium manganese silicate), but with proper polyanion substitution, they can be designed to overcome the key shortcomings of CP cathodes, such as poor electrical conductivity and irreversible phase changes. Iron phosphate/vanadate glasses were chosen as a first demonstration of the MP glass concept. Polyanion substitution with vanadate was shown to improve the intercalation capacity of an iron phosphate glass from almost zero to full theoretical capacity. In addition, the MP glass cathodes also exhibited an unexpected second high-capacity electrochemical reaction. X-ray absorption near-edge structure (XANES) and x-ray diffraction (XRD) of cathodes from cells having different states of charge suggested that this second electrochemical reaction is a glass-state conversion reaction. With a first demonstration established, MP glass materials utilizing an intercalation and/or glass-state conversion reaction are promising candidates for future high-energy cathode research.

  20. Primordial fluctuations from complex AdS saddle points

    SciTech Connect

    Hertog, Thomas; Woerd, Ellen van der E-mail: ellen@itf.fys.kuleuven.be

    2016-02-01

    One proposal for dS/CFT is that the Hartle-Hawking (HH) wave function in the large volume limit is equal to the partition function of a Euclidean CFT deformed by various operators. All saddle points defining the semiclassical HH wave function in cosmology have a representation in which their interior geometry is part of a Euclidean AdS domain wall with complex matter fields. We compute the wave functions of scalar and tensor perturbations around homogeneous isotropic complex saddle points, turning on single scalar field matter only. We compare their predictions for the spectra of CMB perturbations with those of a different dS/CFT proposal based on the analytic continuation of inflationary universes to real asymptotically AdS domain walls. We find the predictions of both bulk calculations agree to first order in the slow roll parameters, but there is a difference at higher order which, we argue, is a signature of the HH state of the fluctuations.

  1. Conserved charges in timelike warped AdS3 spaces

    NASA Astrophysics Data System (ADS)

    Donnay, L.; Fernández-Melgarejo, J. J.; Giribet, G.; Goya, A.; Lavia, E.

    2015-06-01

    We consider the timelike version of warped anti-de Sitter space (WAdS), which corresponds to the three-dimensional section of the Gödel solution of four-dimensional cosmological Einstein equations. This geometry presents closed timelike curves (CTCs), which are inherited from its four-dimensional embedding. In three dimensions, this type of solution can be supported without matter provided the graviton acquires mass. Here, among the different ways to consistently give mass to the graviton in three dimensions, we consider the parity-even model known as new massive gravity (NMG). In the bulk of timelike WAdS3 space, we introduce defects that, from the three-dimensional point of view, represent spinning massive particlelike objects. For this type of source, we investigate the definition of quasilocal gravitational energy as seen from infinity, far beyond the region where the CTCs appear. We also consider the covariant formalism applied to NMG to compute the mass and the angular momentum of spinning particlelike defects and compare the result with the one obtained by means of the quasilocal stress tensor. We apply these methods to special limits in which the WAdS3 solutions coincide with locally AdS3 and locally AdS2×R spaces. Finally, we make some comments about the asymptotic symmetry algebra of asymptotically WAdS3 spaces in NMG.

  2. AdS nonlinear instability: moving beyond spherical symmetry

    NASA Astrophysics Data System (ADS)

    Dias, Óscar J. C.; Santos, Jorge E.

    2016-12-01

    Anti-de Sitter (AdS) is conjectured to be nonlinear unstable to a weakly turbulent mechanism that develops a cascade towards high frequencies, leading to black hole formation (Dafermos and Holzegel 2006 Seminar at DAMTP (University of Cambridge) available at https://dpmms.cam.ac.uk/~md384/ADSinstability.pdf, Bizon and Rostworowski 2011 Phys. Rev. Lett. 107 031102). We give evidence that the gravitational sector of perturbations behaves differently from the scalar one studied by Bizon and Rostworowski. In contrast with Bizon and Rostworowski, we find that not all gravitational normal modes of AdS can be nonlinearly extended into periodic horizonless smooth solutions of the Einstein equation. In particular, we show that even seeds with a single normal mode can develop secular resonances, unlike the spherically symmetric scalar field collapse studied by Bizon and Rostworowski. Moreover, if the seed has two normal modes, more than one resonance can be generated at third order, unlike the spherical collapse of Bizon and Rostworowski. We also show that weak turbulent perturbative theory predicts the existence of direct and inverse cascades, with the former dominating the latter for equal energy two-mode seeds.

  3. Strings on AdS wormholes and nonsingular black holes

    NASA Astrophysics Data System (ADS)

    Lü, H.; Vázquez-Poritz, Justin F.; Zhang, Zhibai

    2015-01-01

    Certain AdS black holes in the STU model can be conformally scaled to wormhole and black hole backgrounds which have two asymptotically AdS regions and are completely free of curvature singularities. While there is a delta-function source for the dilaton, classical string probes are not sensitive to this singularity. According to the AdS/CFT correspondence, the dual field theory lives on the union of the disjoint boundaries. For the wormhole background, causal contact exists between the two boundaries and the structure of certain correlation functions is indicative of an interacting phase for which there is a coupling between the degrees of freedom living at each boundary. The nonsingular black hole describes an entangled state in two non-interacting identical conformal field theories. By studying the behavior of open strings on these backgrounds, we extract a number of features of the ‘quarks’ and ‘anti-quarks’ that live in the field theories. In the interacting phase, we find that there is a maximum speed with which the quarks can move without losing energy, beyond which energy is transferred from a quark in one field theory to a quark in the other. We also compute the rate at which moving quarks within entangled states lose energy to the two surrounding plasmas. While a quark-antiquark pair within a single field theory exhibits Coulomb interaction for small separation, a quark in one field theory exhibits spring-like confinement with an anti-quark in the other field theory. For the entangled states, we study how the quark-antiquark screening length depends on temperature and chemical potential.

  4. Waste product profile: Glass containers

    SciTech Connect

    Miller, C.

    1995-09-01

    In 1992, Waste Age initiated the Waste Product Profile series -- brief, factual listings of the solid waste management characteristics of materials in the solid waste stream. This popular series of profiles high-lighted a product, explained how it fit into integrated waste management systems, and provided current data on recycling and markets for the product. Glass containers are made from sand, limestone, soda ash, cullet (crushed bottles), and various additives, including those used to produce green, brown, and blue glass. Other glass products include flat glass, such as windows, and fiberglass products, such as insulation and glassware. These products are manufactured using different processes and different additives than container glass. This profile covers only glass containers.

  5. Fracture mechanics of cellular glass

    NASA Technical Reports Server (NTRS)

    Zwissler, J. G.; Adams, M. A.

    1981-01-01

    The fracture mechanics of cellular glasses (for the structural substrate of mirrored glass for solr concentrator reflecting panels) are discussed. Commercial and developmental cellular glasses were tested and analyzed using standard testing techniques and models developed from linear fracture mechanics. Two models describing the fracture behavior of these materials were developed. Slow crack growth behavior in cellular glass was found to be more complex than that encountered in dense glasses or ceramics. The crack velocity was found to be strongly dependent upon water vapor transport to the tip of the moving crack. The existence of a static fatigue limit was not conclusively established, however, it is speculated that slow crack growth behavior in Region 1 may be slower, by orders of magnitude, than that found in dense glasses.

  6. DSC and Raman studies of silver borotellurite glasses

    NASA Astrophysics Data System (ADS)

    Kaur, Amandeep; Khanna, Atul; Gonzàlez, Fernando

    2016-05-01

    Silver borotellurite glasses of composition: xAg2O-yB2O3-(100-x-y)TeO2 (x=20-mol%, y = 0, 10, 20 and 30-mol%) were prepared and characterized by density, X-ray diffraction (XRD), differential scanning calorimetry, and Raman spectroscopy. XRD confirmed the amorphous structure of all samples. Density of glasses decreases while the glass transition temperature increases with increase in B2O3 content from 10 to 30-mol%. Raman study shows that coordination number of Te with oxygen decreases steadily from 3.42 to 3.18 on adding B2O3 due to the transformation of TeO4 into TeO3 units.

  7. PLZT capacitor on glass substrate

    DOEpatents

    Fairchild, Manuel Ray; Taylor, Ralph S.; Berlin, Carl W.; Wong, Celine Wk; Ma, Beihai; Balachandran, Uthamalingam

    2016-03-29

    A lead-lanthanum-zirconium-titanate (PLZT) capacitor on a substrate formed of glass. The first metallization layer is deposited on a top side of the substrate to form a first electrode. The dielectric layer of PLZT is deposited over the first metallization layer. The second metallization layer deposited over the dielectric layer to form a second electrode. The glass substrate is advantageous as glass is compatible with an annealing process used to form the capacitor.

  8. PLZT capacitor on glass substrate

    DOEpatents

    Fairchild, M. Ray; Taylor, Ralph S.; Berlin, Carl W.; Wong, Celine W. K.; Ma, Beihai; Balachandran, Uthamalingam

    2016-01-05

    A lead-lanthanum-zirconium-titanate (PLZT) capacitor on a substrate formed of glass. The first metallization layer is deposited on a top side of the substrate to form a first electrode. The dielectric layer of PLZT is deposited over the first metallization layer. The second metallization layer deposited over the dielectric layer to form a second electrode. The glass substrate is advantageous as glass is compatible with an annealing process used to form the capacitor.

  9. Recycled Glass and Dredged Materials

    DTIC Science & Technology

    2007-03-01

    stations, and is either source-separated or co-mingled with plastics , aluminum cans, ceramics, or colored glass containers. In the United States in...cullet (for new bottles and other containers) or non-container glass cullet (all other uses), and non-container processed cullet production is...aggregates (i.e. opposition to change), cost, and regulations. Contamination and Safety Issues. Recycled container glass may contain debris (defined as

  10. Space processing of chalcogenide glass

    NASA Technical Reports Server (NTRS)

    Larsen, D. C.; Ali, M. I.

    1977-01-01

    The manner in which the weightless, containerless nature of in-space processing can be successfully utilized to improve the quality of infrared transmitting chalcogenide glasses is determined. The technique of space processing chalcogenide glass was developed, and the process and equipment necessary to do so was defined. Earthbound processing experiments with As2S3 and G28Sb12Se60 glasses were experimented with. Incorporated into these experiments is the use of an acoustic levitation device.

  11. The structure and properties of ternary zinc phosphate glasses for optical applications

    NASA Astrophysics Data System (ADS)

    Smith, Charmayne Elizabeth

    This dissertation focuses on the properties and structures of ternary zinc phosphate glasses that have recently been investigated as substrates for femto-second (fs) laser writing. Although these glasses have potential for use as optical substrates, their poor chemical properties limit their applications. In this work, ternary zinc phosphate glasses were studied to find compositions with enhanced chemical durability and the properties and structures of the investigated glasses are reported. Paper 1 and Paper 2 include the first systematic studies of the properties, structures of zinc aluminophosphate (ZAP) glasses and phase relationships in the ZnO-Al2O3-P2O5 system, respectively. Adding alumina to a Zn-metaphosphate glass reduces dissolution rates in water by 4 orders of magnitude and increases the glass transition temperatures. The average Al coordination number can be predicted from a structural model that considers the number of non-bridging oxygens to coordinate metal cations, and this work is the first reported use of this model for a ternary phosphate glass. Paper 3 is the first systematic study of how the properties and structures of zinc magnesium polyphosphate glasses change when MgO replaces ZnO for compositions with fixed O/P ratios. The Mg2+ and Zn2+ ions have similar field strengths, but have much different effects on glass properties that are discussed in terms of relative polarizabilities (refractivities) and electron configurations of the Mg2+ and Zn2+ ions. In Paper 4, the creation of electronic defects in zinc phosphate glasses by exposure to ultraviolet and x-ray radiation is described. The nature of the defects formed is dependent on the glass composition and similar defects are created when these glasses are exposed to femto-second laser radiation.

  12. Glass corrosion in natural environment

    NASA Technical Reports Server (NTRS)

    Thorpe, Arthur N.

    1989-01-01

    A series of studies of the effects of solutes which appear in natural aqueous environments, specifically Mg and Al, under controlled conditions, permit characterization of the retardation of silicate glass leaching in water containing such solutes. In the case of Mg the interaction with the glass appears to consist of exchange with alkali ions present in the glass to a depth of several microns. The effect of Al can be observed at much lower levels, indicating that the mechanism in the case of Al involves irreversible formation of aluminosilicate species at the glass surface.

  13. Crystallization of copper metaphosphate glass

    NASA Technical Reports Server (NTRS)

    Bae, Byeong-Soo; Weinberg, Michael C.

    1993-01-01

    The effect of the valence state of copper in copper metaphosphate glass on the crystallization behavior and glass transition temperature has been investigated. The crystallization of copper metaphosphate is initiated from the surface and its main crystalline phase is copper metaphosphate (Cu(PO)3),independent of the (Cu sup 2+)/(Cu(total)). However, the crystal morphology, the relative crystallization rates, and their temperature dependences are affected by the (Cu sup 2+)/(Cu (total)) ratio in the glass. On the other hand, the totally oxidized glass crystallizes from all over the surface. The relative crystallization rate of the reduced glass to the totally oxidized glass is large at low temperature, but small at high temperature. The glass transition temperature of the glass increases as the (Cu sup 2+)/(Cu(total)) ratio is raised. It is also found that the atmosphere used during heat treatment does not influence the crystallization of the reduced glass, except for the formation of a very thin CuO surface layer when heated in air.

  14. POLYESTER GLASS PLASTICS FOR SHIPBUILDING,

    DTIC Science & Technology

    POLYESTER PLASTICS , SHIP HULLS), (*SHIP HULLS, POLYESTER PLASTICS ), GLASS TEXTILES, REINFORCING MATERIALS, SHIP STRUCTURAL COMPONENTS, COMPOSITE MATERIALS, PROCESSING, CHEMISTRY, HANDBOOKS, BINDERS, USSR

  15. THERMAL STABILITY OF GLASS PLASTICS.

    DTIC Science & Technology

    COMPOSITE MATERIALS, THERMAL STABILITY), (* GLASS TEXTILES, THERMAL STABILITY), (*LAMINATED PLASTICS , THERMAL STABILITY), HEATING, COOLING, MECHANICAL PROPERTIES, FATIGUE(MECHANICS), FLEXURAL STRENGTH, THERMAL STRESSES, USSR

  16. Halide laser glasses

    SciTech Connect

    Weber, M.J.

    1982-01-14

    Energy storage and energy extraction are of prime importance for efficient laser action and are affected by the line strengths and linewidths of optical transitions, excited-state lifetimes, nonradiative decay processes, spectroscopic inhomogeneities, nonlinear refractive index, and damage threshold. These properties are all host dependent. To illustrate this, the spectroscopic properties of Nd/sup 3 +/ have been measured in numerous oxide, oxyhalide, and halide glasses. A table summarizes the reported ranges of stimulated emission cross sections, peak wavelengths, linewidths, and radiative lifetimes associated with the /sup 4/F/sub 3/2/ ..-->.. /sup 4/I/sub 11/2/ lasing transition.

  17. Glass rupture disk

    DOEpatents

    Glass, S. Jill; Nicolaysen, Scott D.; Beauchamp, Edwin K.

    2002-01-01

    A frangible rupture disk and mounting apparatus for use in blocking fluid flow, generally in a fluid conducting conduit such as a well casing, a well tubing string or other conduits within subterranean boreholes. The disk can also be utilized in above-surface pipes or tanks where temporary and controllable fluid blockage is required. The frangible rupture disk is made from a pre-stressed glass with controllable rupture properties wherein the strength distribution has a standard deviation less than approximately 5% from the mean strength. The frangible rupture disk has controllable operating pressures and rupture pressures.

  18. Solarization of heliostat glasses

    NASA Astrophysics Data System (ADS)

    Vitko, J., Jr.; Shelby, J. E.

    1980-09-01

    A solar-induced decrease in Fe(2+) absorption was observed in heliostat glasses from the solar furnace at Odeillo, France. This decrease occurs throughout the sample and is of sufficient magnitude to result in an increase of 2.5% in solar transmittance in a period of nine years. Optical and ESR studies did not detect a corresponding increase in Fe(3+) concentration. The effect of these results on a microscopic model for the observed solarization is discussed. Solar simulation studies produced changes of magnitude and sign similar to those observed in the field exposed samples, and offer attractive means for screening samples for solarization tendencies.

  19. Separating Growth from Value Added

    ERIC Educational Resources Information Center

    Yeagley, Raymond

    2007-01-01

    This article discusses Rochester's two academic models that offer different tools for different purposes--measuring individual learning and measuring what affects learning. The main focus of currently available growth measures is formative assessment--providing data to inform instructional planning. Value-added assessment is not a student…

  20. Adding Value to Indiana's Commodities.

    ERIC Educational Resources Information Center

    Welch, Mary A., Ed.

    1995-01-01

    Food processing plants are adding value to bulk and intermediate products to sell overseas. The Asian Pacific Rim economies constituted the largest market for consumer food products in 1993. This shift toward consumer food imports in this area is due to more women working outside the home, the internationalization of populations, and dramatic…

  1. Courtship American Style: Newspaper Ads

    ERIC Educational Resources Information Center

    Cameron, Catherine; And Others

    1977-01-01

    This study investigated an increasing social phenomenon--newspaper advertising for dating or marital partners--in terms of the bargaining process involved. Content analysis of personal ads in a popular "respectable" singles newspaper revealed a pattern of offers and requests reminiscent of a heterosexual stock market. (Author)

  2. Compositional threshold for Nuclear Waste Glass Durability

    SciTech Connect

    Kruger, Albert A.; Farooqi, Rahmatullah; Hrma, Pavel R.

    2013-04-24

    Within the composition space of glasses, a distinct threshold appears to exist that separates "good" glasses, i.e., those which are sufficiently durable, from "bad" glasses of a low durability. The objective of our research is to clarify the origin of this threshold by exploring the relationship between glass composition, glass structure and chemical durability around the threshold region.

  3. Method for heating a glass sheet

    DOEpatents

    Boaz, P.T.

    1998-07-21

    A method for heating a glass sheet includes the steps of heating a glass sheet to a first predetermined temperature and applying microwave energy to the glass sheet to heat the glass sheet to at least a second predetermined temperature to allow the glass sheet to be formed. 5 figs.

  4. Method for heating a glass sheet

    DOEpatents

    Boaz, Premakaran Tucker

    1998-01-01

    A method for heating a glass sheet includes the steps of heating a glass sheet to a first predetermined temperature and applying microwave energy to the glass sheet to heat the glass sheet to at least a second predetermined temperature to allow the glass sheet to be formed.

  5. Examination of glass-silicon and glass-glass bonding techniques for microfluidic systems

    SciTech Connect

    Raley, N.F.; Davidson, J.C.; Balch, J.W.

    1995-10-23

    We report here on the results of experiments concerning particular bonding processes potentially useful for ultimate miniaturization of microfluidic systems. Direct anodic bonding of continuous thin pyrex glass of 250 {mu}m thickness to silicon substrates gives multiple, large voids in the glass. Etchback of thick glass of 1200 {mu}m thickness bonded to silicon substrates gives thin continuous glass layers of 189 {mu}m thickness without voids over areas of 5 cm {times} 12 cm. Glass was also successfully bonded to glass by thermal bonding at 800{degrees}C over a 5 cm {times} 7 cm area. Anticipated applications include microfabricated DNA sequencing, flow injection analysis, and liquid and gas chromatography microinstruments.

  6. Production of coloured glass-ceramics from incinerator ash using thermal plasma technology.

    PubMed

    Cheng, T W; Huang, M Z; Tzeng, C C; Cheng, K B; Ueng, T H

    2007-08-01

    Incineration is a major treatment process for municipal solid waste in Taiwan. It is estimated that over 1.5 Mt of incinerator ash are produced annually. This study proposes using thermal plasma technology to treat incinerator ash. Sintered glass-ceramics were produced using quenched vitrified slag with colouring agents added. The experimental results showed that the major crystalline phases developed in the sintered glass-ceramics were gehlenite and wollastonite, but many other secondary phases also appeared depending on the colouring agents added. The physical/mechanical properties, chemical resistance and toxicity characteristic leaching procedure of the coloured glass-ceramics were satisfactory. The glass-ceramic products obtained from incinerator ash treated with thermal plasma technology have great potential for building applications.

  7. An investigation of AdS2 backreaction and holography

    NASA Astrophysics Data System (ADS)

    Engelsöy, Julius; Mertens, Thomas G.; Verlinde, Herman

    2016-07-01

    We investigate a dilaton gravity model in AdS2 proposed by Almheiri and Polchinski [1] and develop a 1d effective description in terms of a dynamical boundary time with a Schwarzian derivative action. We show that the effective model is equivalent to a 1d version of Liouville theory, and investigate its dynamics and symmetries via a standard canonical framework. We include the coupling to arbitrary conformal matter and analyze the effective action in the presence of possible sources. We compute commutators of local operators at large time separation, and match the result with the time shift due to a gravitational shockwave interaction. We study a black hole evaporation process and comment on the role of entropy in this model.

  8. Supersymmetry Properties of AdS Supergravity Backgrounds

    NASA Astrophysics Data System (ADS)

    Beck, Samuel; Gutowski, Jan; Papadopoulos, George

    2017-01-01

    Anti-de Sitter supergravity backgrounds are of particular interest in light of the AdS/CFT correspondence, which relates them to dual conformal field theories on the boundary of the anti-de Sitter space. We have investigated the forms of the supersymmetries these backgrounds preserve by solving the Killing spinor equations on the anti-de Sitter components of these spaces. We have found that a supersymmetric AdSn background necessarily preserves 2⌊n/2⌋ k supersymmetries for n <= 4 and 2 ⌊n/2 ⌋ + 1 k supersymmetries for 4 < n <= 7 , k ∈N> 0 . Additionally, we have found that the Killing spinors of each background are exactly the zeroes of a Dirac-like operator constructed from the Killing spinor equations.

  9. The Massive Wave Equation in Asymptotically AdS Spacetimes

    NASA Astrophysics Data System (ADS)

    Warnick, C. M.

    2013-07-01

    We consider the massive wave equation on asymptotically AdS spaces. We show that the timelike F behaves like a finite timelike boundary, on which one may impose the equivalent of Dirichlet, Neumann or Robin conditions for a range of (negative) mass parameter which includes the conformally coupled case. We demonstrate well posedness for the associated initial-boundary value problems at the H 1 level of regularity. We also prove that higher regularity may be obtained, together with an asymptotic expansion for the field near F. The proofs rely on energy methods, tailored to the modified energy introduced by Breitenlohner and Freedman. We do not assume the spacetime is stationary, nor that the wave equation separates.

  10. On jordanian deformations of AdS5 and supergravity

    NASA Astrophysics Data System (ADS)

    Hoare, Ben; van Tongeren, Stijn J.

    2016-10-01

    We consider various homogeneous Yang-Baxter deformations of the {{AdS}}5× {{{S}}}5 superstring that can be obtained from the η-deformed superstring and related models by singular boosts. The jordanian deformations we obtain in this way behave similarly to the η-deformed model with regard to supergravity: T dualizing the classical sigma model it is possible to find corresponding solutions of supergravity, which, however, have dilatons that prevent T dualizing back. Hence the backgrounds of these jordanian deformations are not solutions of supergravity. Still, they do satisfy a set of recently found modified supergravity equations which implies that the corresponding sigma models are scale invariant. The abelian models that we obtain by singular boosts do directly correspond to solutions of supergravity. In addition to our main results we consider contraction limits of our main example, which do correspond to supergravity solutions.

  11. Aspects of warped AdS3/CFT2 correspondence

    NASA Astrophysics Data System (ADS)

    Chen, Bin; Zhang, Jia-Ju; Zhang, Jian-Dong; Zhong, De-Liang

    2013-04-01

    In this paper we apply the thermodynamics method to investigate the holographic pictures for the BTZ black hole, the spacelike and the null warped black holes in three-dimensional topologically massive gravity (TMG) and new massive gravity (NMG). Even though there are higher derivative terms in these theories, the thermodynamics method is still effective. It gives consistent results with the ones obtained by using asymptotical symmetry group (ASG) analysis. In doing the ASG analysis we develop a brute-force realization of the Barnich-Brandt-Compere formalism with Mathematica code, which also allows us to calculate the masses and the angular momenta of the black holes. In particular, we propose the warped AdS3/CFT2 correspondence in the new massive gravity, which states that quantum gravity in the warped spacetime could holographically dual to a two-dimensional CFT with {c_R}={c_L}=24 /{Gm{β^2√{{2( {21-4{β^2}} )}}}}.

  12. POROUS WALL, HOLLOW GLASS MICROSPHERES

    SciTech Connect

    Sexton, W.

    2012-06-30

    Hollow Glass Microspheres (HGM) is not a new technology. All one has to do is go to the internet and Google{trademark} HGM. Anyone can buy HGM and they have a wide variety of uses. HGM are usually between 1 to 100 microns in diameter, although their size can range from 100 nanometers to 5 millimeters in diameter. HGM are used as lightweight filler in composite materials such as syntactic foam and lightweight concrete. In 1968 a patent was issued to W. Beck of the 3M{trademark} Company for 'Glass Bubbles Prepared by Reheating Solid Glass Particles'. In 1983 P. Howell was issued a patent for 'Glass Bubbles of Increased Collapse Strength' and in 1988 H. Marshall was issued a patent for 'Glass Microbubbles'. Now Google{trademark}, Porous Wall, Hollow Glass Microspheres (PW-HGMs), the key words here are Porous Wall. Almost every article has its beginning with the research done at the Savannah River National Laboratory (SRNL). The Savannah River Site (SRS) where SRNL is located has a long and successful history of working with hydrogen and its isotopes for national security, energy, waste management and environmental remediation applications. This includes more than 30 years of experience developing, processing, and implementing special ceramics, including glasses for a variety of Department of Energy (DOE) missions. In the case of glasses, SRS and SRNL have been involved in both the science and engineering of vitreous or glass based systems. As a part of this glass experience and expertise, SRNL has developed a number of niches in the glass arena, one of which is the development of porous glass systems for a variety of applications. These porous glass systems include sol gel glasses, which include both xerogels and aerogels, as well as phase separated glass compositions, that can be subsequently treated to produce another unique type of porosity within the glass forms. The porous glasses can increase the surface area compared to 'normal glasses of a 1 to 2 order of

  13. Systematics of Coupling Flows in AdS Backgrounds

    SciTech Connect

    Goldberger, Walter D.; Rothstein, Ira Z.

    2003-03-18

    We give an effective field theory derivation, based on the running of Planck brane gauge correlators, of the large logarithms that arise in the predictions for low energy gauge couplings in compactified AdS}_5 backgrounds, including the one-loop effects of bulk scalars, fermions, and gauge bosons. In contrast to the case of charged scalars coupled to Abelian gauge fields that has been considered previously in the literature, the one-loop corrections are not dominated by a single 4D Kaluza-Klein mode. Nevertheless, in the case of gauge field loops, the amplitudes can be reorganized into a leading logarithmic contribution that is identical to the running in 4D non-Abelian gauge theory, and a term which is not logarithmically enhanced and is analogous to a two-loop effect in 4D. In a warped GUT model broken by the Higgs mechanism in the bulk,we show that the matching scale that appears in the large logarithms induced by the non-Abelian gauge fields is m_{XY}^2/k where m_{XY} is the bulk mass of the XY bosons and k is the AdS curvature. This is in contrast to the UV scale in the logarithmic contributions of scalars, which is simply the bulk mass m. Our results are summarized in a set of simple rules that can be applied to compute the leading logarithmic predictions for coupling constant relations within a given warped GUT model. We present results for both bulk Higgs and boundary breaking of the GUT gauge

  14. Holography beyond conformal invariance and AdS isometry?

    SciTech Connect

    Barvinsky, A. O.

    2015-03-15

    We suggest that the principle of holographic duality be extended beyond conformal invariance and AdS isometry. Such an extension is based on a special relation between functional determinants of the operators acting in the bulk and on its boundary, provided that the boundary operator represents the inverse propagators of the theory induced on the boundary by the Dirichlet boundary value problem in the bulk spacetime. This relation holds for operators of a general spin-tensor structure on generic manifolds with boundaries irrespective of their background geometry and conformal invariance, and it apparently underlies numerous O(N{sup 0}) tests of the AdS/CFT correspondence, based on direct calculation of the bulk and boundary partition functions, Casimir energies, and conformal anomalies. The generalized holographic duality is discussed within the concept of the “double-trace” deformation of the boundary theory, which is responsible in the case of large-N CFT coupled to the tower of higher-spin gauge fields for the renormalization group flow between infrared and ultraviolet fixed points. Potential extension of this method beyond the one-loop order is also briefly discussed.

  15. Quinary metallic glass alloys

    DOEpatents

    Lin, X.; Johnson, W.L.

    1998-04-07

    At least quinary alloys form metallic glass upon cooling below the glass transition temperature at a rate less than 10{sup 3}K/s. Such alloys comprise zirconium and/or hafnium in the range of 45 to 65 atomic percent, titanium and/or niobium in the range of 4 to 7.5 atomic percent, and aluminum and/or zinc in the range of 5 to 15 atomic percent. The balance of the alloy compositions comprise copper, iron, and cobalt and/or nickel. The composition is constrained such that the atomic percentage of iron is less than 10 percent. Further, the ratio of copper to nickel and/or cobalt is in the range of from 1:2 to 2:1. The alloy composition formula is: (Zr,Hf){sub a}(Al,Zn){sub b}(Ti,Nb){sub c}(Cu{sub x}Fe{sub y}(Ni,Co){sub z}){sub d} wherein the constraints upon the formula are: a ranges from 45 to 65 atomic percent, b ranges from 5 to 15 atomic percent, c ranges from 4 to 7.5 atomic percent, d comprises the balance, d{hor_ellipsis}y is less than 10 atomic percent, and x/z ranges from 0.5 to 2.

  16. Quinary metallic glass alloys

    DOEpatents

    Lin, Xianghong; Johnson, William L.

    1998-01-01

    At least quinary alloys form metallic glass upon cooling below the glass transition temperature at a rate less than 10.sup.3 K/s. Such alloys comprise zirconium and/or hafnium in the range of 45 to 65 atomic percent, titanium and/or niobium in the range of 4 to 7.5 atomic percent, and aluminum and/or zinc in the range of 5 to 15 atomic percent. The balance of the alloy compositions comprise copper, iron, and cobalt and/or nickel. The composition is constrained such that the atomic percentage of iron is less than 10 percent. Further, the ratio of copper to nickel and/or cobalt is in the range of from 1:2 to 2:1. The alloy composition formula is: (Zr,Hf).sub.a (Al,Zn).sub.b (Ti,Nb).sub.c (Cu.sub.x Fe.sub.y (Ni,Co).sub.z).sub.d wherein the constraints upon the formula are: a ranges from 45 to 65 atomic percent, b ranges from 5 to 15 atomic percent, c ranges from 4 to 7.5 atomic percent, d comprises the balance, d.multidot.y is less than 10 atomic percent, and x/z ranges from 0.5 to 2.

  17. Spheroidization of glass powders for glass ionomer cements.

    PubMed

    Gu, Y W; Yap, A U J; Cheang, P; Kumar, R

    2004-08-01

    Commercial angular glass powders were spheroidized using both the flame spraying and inductively coupled radio frequency plasma spraying techniques. Spherical powders with different particle size distributions were obtained after spheroidization. The effects of spherical glass powders on the mechanical properties of glass ionomer cements (GICs) were investigated. Results showed that the particle size distribution of the glass powders had a significant influence on the mechanical properties of GICs. Powders with a bimodal particle size distribution ensured a high packing density of glass ionomer cements, giving relatively high mechanical properties of GICs. GICs prepared by flame-spheroidized powders showed low strength values due to the loss of fine particles during flame spraying, leading to a low packing density and few metal ions reacting with polyacrylic acid to form cross-linking. GICs prepared by the nano-sized powders showed low strength because of the low bulk density of the nano-sized powders and hence low powder/liquid ratio of GICs.

  18. Mechanical failure and glass transition in metallic glasses

    SciTech Connect

    Egami, Takeshi

    2011-01-01

    The current majority view on the phenomenon of mechanical failure in metallic glasses appears to be that it is caused by the activity of some structural defects, such as free-volumes or shear transformation zones, and the concentration of such defects is small, only of the order of 1%. However, the recent results compel us to revise this view. Through molecular dynamics simulation it has been shown that mechanical failure is the stress-induced glass transition. According to our theory the concentration of the liquid-like sites (defects) is well over 20% at the glass transition. We suggest that the defect concentration in metallic glasses is actually very high, and percolation of such defects causes atomic avalanche and mechanical failure. In this article we discuss the glass transition, mechanical failure and viscosity from such a point of view.

  19. Glasses in the D'Orbigny Angrite

    NASA Astrophysics Data System (ADS)

    Varela, M. E.; Kurat, G.; Brandstätter, F.; Bonnin-Mosbah, M.; Metrich, N.

    2001-03-01

    The D'Orbigny angrite contains abundant glasses, a phase which has not been previously reported from any other angrite. Glasses fill in part open druses and intersticial spaces between major silicates, or occur as glass inclusions in olivine.

  20. Degradable borate glass polyalkenoate cements.

    PubMed

    Shen, L; Coughlan, A; Towler, M; Hall, M

    2014-04-01

    Glass polyalkenoate cements (GPCs) containing aluminum-free borate glasses having the general composition Ag2O-Na2O-CaO-SrO-ZnO-TiO2-B2O3 were evaluated in this work. An initial screening study of sixteen compositions was used to identify regions of glass formation and cement compositions with promising rheological properties. The results of the screening study were used to develop four model borate glass compositions for further study. A second round of rheological experiments was used to identify a preferred GPC formulation for each model glass composition. The model borate glasses containing higher levels of TiO2 (7.5 mol %) tended to have longer working times and shorter setting times. Dissolution behavior of the four model GPC formulations was evaluated by measuring ion release profiles as a function of time. All four GPC formulations showed evidence of incongruent dissolution behavior when considering the relative release profiles of sodium and boron, although the exact dissolution profile of the glass was presumably obscured by the polymeric cement matrix. Compression testing was undertaken to evaluate cement strength over time during immersion in water. The cements containing the borate glass with 7.5 mol % TiO2 had the highest initial compressive strength, ranging between 20 and 30 MPa. No beneficial aging effect was observed-instead, the strength of all four model GPC formulations was found to degrade with time.

  1. Method of determining glass durability

    DOEpatents

    Jantzen, C.M.; Pickett, J.B.; Brown, K.G.; Edwards, T.B.

    1998-12-08

    A process is described for determining one or more leachate concentrations of one or more components of a glass composition in an aqueous solution of the glass composition by identifying the components of the glass composition, including associated oxides, determining a preliminary glass dissolution estimator, {Delta}G{sub p}, based upon the free energies of hydration for the component reactant species, determining an accelerated glass dissolution function, {Delta}G{sub a}, based upon the free energy associated with weak acid dissociation, {Delta}G{sub a}{sup WA}, and accelerated matrix dissolution at high pH, {Delta}G{sub a}{sup SB} associated with solution strong base formation, and determining a final hydration free energy, {Delta}G{sub f}. This final hydration free energy is then used to determine leachate concentrations for elements of interest using a regression analysis and the formula log{sub 10}(N C{sub i}(g/L))=a{sub i} + b{sub i}{Delta}G{sub f}. The present invention also includes a method to determine whether a particular glass to be produced will be homogeneous or phase separated. The present invention is also directed to methods of monitoring and controlling processes for making glass using these determinations to modify the feedstock materials until a desired glass durability and homogeneity is obtained. 4 figs.

  2. Method of determining glass durability

    DOEpatents

    Jantzen, Carol Maryanne; Pickett, John Butler; Brown, Kevin George; Edwards, Thomas Barry

    1998-01-01

    A process for determining one or more leachate concentrations of one or more components of a glass composition in an aqueous solution of the glass composition by identifying the components of the glass composition, including associated oxides, determining a preliminary glass dissolution estimator, .DELTA.G.sub.p, based upon the free energies of hydration for the component reactant species, determining an accelerated glass dissolution function, .DELTA.G.sub.a, based upon the free energy associated with weak acid dissociation, .DELTA.G.sub.a.sup.WA, and accelerated matrix dissolution at high pH, .DELTA.G.sub.a.sup.SB associated with solution strong base formation, and determining a final hydration free energy, .DELTA.G.sub.f. This final hydration free energy is then used to determine leachate concentrations for elements of interest using a regression analysis and the formula log.sub.10 (N C.sub.i (g/L))=a.sub.i +b.sub.i .DELTA.G.sub.f. The present invention also includes a method to determine whether a particular glass to be produced will be homogeneous or phase separated. The present invention is also directed to methods of monitoring and controlling processes for making glass using these determinations to modify the feedstock materials until a desired glass durability and homogeneity is obtained.

  3. Space processing of chalcogenide glass

    NASA Technical Reports Server (NTRS)

    Firestone, R. F.; Schramm, S. W.

    1978-01-01

    A program was conducted to develop the technique of space processing for chalcogenide glass, and to define the process and equipment necessary. In the course of this program, successful long term levitation of objects in a 1-g environment was achieved. Glass beads 4 mm diameter were containerless melted and fused together.

  4. Training Guidelines: Glass Furnace Operators.

    ERIC Educational Resources Information Center

    Ceramics, Glass, and Mineral Products Industry Training Board, Harrow (England).

    Technological development in the glass industry is constantly directed towards producing high quality glass at low operating costs. Particularly, changes have taken place in melting methods which mean that the modern furnace operator has greater responsibilities than any of his predecessors. The complexity of control systems, melting rates, tank…

  5. Refractory Glass Seals for SOFC

    SciTech Connect

    Chou, Y. S.; Stevenson, Jeffry W.

    2011-07-01

    One of the critical challenges facing planar solid oxide fuel cell (SOFC) technology is the need for reliable sealing technology. Seals must exhibit long-term stability and mechanical integrity in the high temperature SOFC environment during normal and transient operation. Several different approaches for sealing SOFC stacks are under development, including glass or glass-ceramic seals, metallic brazes, and compressive seals. Among glass seals, rigid glass-ceramics, self-healing glass, and composite glass approaches have been investigated under the SECA Core Technology Program. The U.S. Department of Energy's Pacific Northwest National Laboratory (PNNL) has developed the refractory glass approach in light of the fact that higher sealing temperatures (e.g., 930-1000 degrees C) may enhance the ultimate in-service bulk strength and electrical conductivity of contact materials, as well as the bonding strength between contact materials and adjacent SOFC components, such as interconnect coatings and electrodes. This report summarizes the thermal, chemical, mechanical, and electrical properties of the refractory sealing glass.

  6. Making a Better Beer Glass.

    ERIC Educational Resources Information Center

    Hoffer, Alan R.

    1982-01-01

    A class activity is detailed in which alternative designs for glasses are examined. The goal is to design a glass which is built tilted, so that beer can be poured in without creating a foam problem. The activity is viewed as one leading to interesting questions. (MP)

  7. Holder for rotating glass body

    DOEpatents

    Kolleck, Floyd W.

    1978-04-04

    A device is provided for holding and centering a rotating glass body such as a rod or tube. The device includes a tubular tip holder which may be held in a lathe chuck. The device can utilize a variety of centering tips each adapted for a particular configuration, such as a glass O-ring joint or semi-ball joint.

  8. International Congress on Glass XII

    SciTech Connect

    Doremus, R H; LaCourse, W C; Mackenzie, J D; Varner, J R; Wolf, W W

    1980-01-01

    A total of 158 papers are included under nine headings: structure and glass formation; optical properties; electrical and magnetic properties; mechanical properties and relaxation; mass transport; chemical durability and surfaces; nucleation; crystallization; and glass ceramics; processing; and automatic controls. Separate abstracts were prepared for eight papers; four of the remaining papers had been processed previously for the data base. (DLC)

  9. Realizing "value-added" metrology

    NASA Astrophysics Data System (ADS)

    Bunday, Benjamin; Lipscomb, Pete; Allgair, John; Patel, Dilip; Caldwell, Mark; Solecky, Eric; Archie, Chas; Morningstar, Jennifer; Rice, Bryan J.; Singh, Bhanwar; Cain, Jason; Emami, Iraj; Banke, Bill, Jr.; Herrera, Alfredo; Ukraintsev, Vladamir; Schlessinger, Jerry; Ritchison, Jeff

    2007-03-01

    The conventional premise that metrology is a "non-value-added necessary evil" is a misleading and dangerous assertion, which must be viewed as obsolete thinking. Many metrology applications are key enablers to traditionally labeled "value-added" processing steps in lithography and etch, such that they can be considered integral parts of the processes. Various key trends in modern, state-of-the-art processing such as optical proximity correction (OPC), design for manufacturability (DFM), and advanced process control (APC) are based, at their hearts, on the assumption of fine-tuned metrology, in terms of uncertainty and accuracy. These trends are vehicles where metrology thus has large opportunities to create value through the engineering of tight and targetable process distributions. Such distributions make possible predictability in speed-sorts and in other parameters, which results in high-end product. Additionally, significant reliance has also been placed on defect metrology to predict, improve, and reduce yield variability. The necessary quality metrology is strongly influenced by not only the choice of equipment, but also the quality application of these tools in a production environment. The ultimate value added by metrology is a result of quality tools run by a quality metrology team using quality practices. This paper will explore the relationships among present and future trends and challenges in metrology, including equipment, key applications, and metrology deployment in the manufacturing flow. Of key importance are metrology personnel, with their expertise, practices, and metrics in achieving and maintaining the required level of metrology performance, including where precision, matching, and accuracy fit into these considerations. The value of metrology will be demonstrated to have shifted to "key enabler of large revenues," debunking the out-of-date premise that metrology is "non-value-added." Examples used will be from critical dimension (CD

  10. Scattering States in AdS/CFT

    SciTech Connect

    Fitzpatrick, A.Liam; Kaplan, Jared; /SLAC

    2012-02-14

    We show that suitably regulated multi-trace primary states in large N CFTs behave like 'in' and 'out' scattering states in the flat-space limit of AdS. Their transition matrix elements approach the exact scattering amplitudes for the bulk theory, providing a natural CFT definition of the flat space S-Matrix. We study corrections resulting from the AdS curvature and particle propagation far from the center of AdS, and show that AdS simply provides an IR regulator that disappears in the flat space limit.

  11. Glass-An Environmental Protector

    SciTech Connect

    MARRA, JAMES

    2004-11-01

    From asbestos abatement to lead paint removal to nuclear waste stabilization and even to heavy metal removal using microorganisms, glass has great potential as a solution to many environmental problems. The ability to accommodate an array of chemical elements within the glass structure has facilitated the use of glass as a medium for the stabilization of numerous hazardous substances. The resulting glasses have proven to be durable enough for direct land disposal. In many cases, the stabilized forms have been deemed suitable for re-use in other applications. As recycling and hazardous material treatment become even more important in the global materials cycle, it is a certainty that glass will assume a prominent role.

  12. Relaxation in quantum glasses

    NASA Astrophysics Data System (ADS)

    Ancona Torres, Carlos E.

    The Ising model in transverse field provides the simplest description of a quantum glass. I study two systems that are realizations of the Ising model in transverse field, LiHoxY1-- xF4 and Rb1-- x(NH4)xH2PO 4. In the spin glass LiHoxY1-- xF4, applying a magnetic field Ht transverse to the Ising direction introduces tunneling between the bare Ising eigenstates. In addition, the coupling between the transverse dipolar interaction and the transverse field introduces entanglement or tunable random fields depending on the concentration. By comparing the classical and quantum transitions in LiHo0.198Y0.802F4 and LiHo 0.167Y0.833F4, I characterize the crossover from random field dominated behavior in the 19.8% sample to entanglement dominated behavior in the 16.7% sample. The quantum transition in the 19.8% sample is dominated by the limit on its correlation length caused by the random fields, while the dominant effect in the 16.7% sample is the enhanced tunneling rate introduced by entanglement. The proton glass Rb1--x(NH 4)xH2PO4 relaxes through tunneling of protons in the hydrogen bonds of the crystal, yielding an effective Ising model in transverse field. Since this field cannot be tuned directly, I combine bulk dielectric susceptibility measurements with neutron Compton scattering measurements of the local tunneling potential in two different concentrations, x = 35% and 72%. I find that tunneling drives the fastest relaxation processes at temperatures as high as 20 K and explicitly calculate the tunneling rate from the tunneling potential of the hydrogen bond. Moreover, the structural mechanism for the glassy relaxation allows a real-space picture of the relaxation dynamics to be correlated to the free energy description of aging. I find that the glassy relaxation is driven by the sequential diffusion of defects called Takagi configurations with a classical to quantum crossover in the relaxation at 3 K. I relate the relaxation rate to the quantum action of tunneling

  13. From Christmas Ornament to Glass Electrode

    NASA Astrophysics Data System (ADS)

    da Rocha, Rogério T.; Gutz, Ivano G. R.; Do Lago, Claudimir L.

    1995-12-01

    In potentiometric techniques, pH measurements require a costly and fragile accessory: the glass electrode. A glass electrode is difficult to make because the wall of the sensing glass bulb must be very thin, and glass of special composition is required. Although the glass bulb may be made by a skilled glazier, we choose a more impressive and simple way. The glass bulb can be made from a Christmas-tree ornamental ball.

  14. Fabrication and characterization of MCC approved testing material: ATM-9 glass

    SciTech Connect

    Wald, J.W.

    1986-06-01

    The Materials Characterization Center ATM-9 glass is designed to be representative of glass to be produced by the Defense Waste Processing Facility at the Savannah River Plant, Aiken, South Carolina. ATM-9 glass contains all of the major components of the DWPF glass and corresponds to a waste loading of 29 wt %. The feedstock material for this glass was supplied by Savannah River Laboratory, Aiken, SC, as SRL-165 Black Frit to which was added Ba, Cs, Md, Nd, Zr, as well as /sup 99/Tc, depleted U, /sup 237/Np, /sup 239 +240/Pu, and /sup 243/Am. The glass was produced under reducing conditions by the addition of 0.7 wt % graphite during the final melting process. Three kilograms of the glass were produced from April to May of 1984. On final melting, the glass was formed into stress-annealed rectangular bars of two sizes: 1.9 x 1.9 x 10 cm and 1.3 x 1.3 x 10 cm. Seventeen bars of each size were made. The analyzed composition of ATM-9 glass is listed. Examination by optical microscopy of a single transverse section from one bar showed random porosity estimated at 0.36 vol % with nominal pore diameters ranging from approx. 5 ..mu..m to 200 ..mu..m. Only one distinct second phase was observed and it was at a low concentraction level in the glass matrix. The phase appeared as spherical metallic particles. X-ray diffraction analysis of this same sample did not show any diffraction peaks from crystalline components, indicating that the glass contained less than 5 wt % of crystalline devitrification products. The even shading on the radiograph exposure indicated a generally uniform distribution of radioactivity throughout the glass matrix, with no distinct high-concentration regions.

  15. Modification of polyester resins during molding of glass-fiber-reinforced plastics

    NASA Astrophysics Data System (ADS)

    Yakushin, V.; Jansons, J.; Bulmanis, V.; Cabulis, U.; Bulmanis, A.

    2013-11-01

    The effect of addition of two new urethane prepolymers on the mechanical properties of unsaturated polyester resins and glass-fiber-reinforced plastics based on them is investigated. The effect of concentration of these additives on the elastic modulus, elongation at break, and flexural strength of hardened orthophthalic resins is evaluated. A significant increase in the strength of the binders and glass-fiber-reinforced plastics (GFRPs) based on them is observed upon adding urethane prepolymers to the resins. The properties of laminated and randomly reinforced glass-fiber plastics with the modified orthophthalic resins are compared with those of similar GFRPs based on popular brands of industrial resins.

  16. Method of glass selection for color correction in optical system design.

    PubMed

    de Albuquerque, Bráulio Fonseca Carneiro; Sasian, Jose; de Sousa, Fabiano Luis; Montes, Amauri Silva

    2012-06-18

    A method of glass selection for the design of optical systems with reduced chromatic aberration is presented. This method is based on the unification of two previously published methods adding new contributions and using a multi-objective approach. This new method makes it possible to select sets of compatible glasses suitable for the design of super-apochromatic optical systems. As an example, we present the selection of compatible glasses and the effective designs for all-refractive optical systems corrected in five spectral bands, with central wavelengths going from 485 nm to 1600 nm.

  17. Retrospective Determination of Radon Exposure to Glass Using Liquid Scintillation Counting

    NASA Astrophysics Data System (ADS)

    Jones, Rodger Ferguson

    A method is introduced whereby glass samples exposed to known levels of ^{222}Rn are analyzed for ^{210}Pb build-up by liquid scintillation counting. This retrospective radon detector relies on the phenomena of recoil of the decaying nuclide on emission of an alpha -particle into the substrate of the glass. Simple liquid scintillation counting is then used to measure the activity of the ^{210}Pb. The surface of the glass containing the decay products is etched with hydrofluoric acid and then added to a scintillant. The method is useful for exposures up from around 250 PCi.l ^{-1}-years giving a correlation of.97 in a controlled laboratory experiment.

  18. 1.8 μm emission of highly thulium doped fluorophosphate glasses

    NASA Astrophysics Data System (ADS)

    Tian, Ying; Xu, Rongrong; Zhang, Liyan; Hu, Lili; Zhang, Junjie

    2010-10-01

    A new type of fluorophosphate glasses with high thulium doping concentration (up to 10 mol % Tm3+) is investigated. The intensive 1.8 μm fluorescence is demonstrated with lower concentration quenching. On the basis of the measured Raman spectroscopy, it is revealed that the glass structure will be changed when adding Tm3+ ions into fluorophosphate glasses. Besides, the Judd-Ofelt parameters and radiative properties are calculated and discussed based on Judd-Ofelt theory. And the absorption and emission cross-sections of F34→H36 transition are also calculated by using McCumber and Beer-Lambert theories.

  19. Glass Ceramic Formulation Data Package

    SciTech Connect

    Crum, Jarrod V.; Rodriguez, Carmen P.; McCloy, John S.; Vienna, John D.; Chung, Chul-Woo

    2012-06-17

    A glass ceramic waste form is being developed for treatment of secondary waste streams generated by aqueous reprocessing of commercial used nuclear fuel (Crum et al. 2012b). The waste stream contains a mixture of transition metals, alkali, alkaline earths, and lanthanides, several of which exceed the solubility limits of a single phase borosilicate glass (Crum et al. 2009; Caurant et al. 2007). A multi-phase glass ceramic waste form allows incorporation of insoluble components of the waste by designed crystallization into durable heat tolerant phases. The glass ceramic formulation and processing targets the formation of the following three stable crystalline phases: (1) powellite (XMoO4) where X can be (Ca, Sr, Ba, and/or Ln), (2) oxyapatite Yx,Z(10-x)Si6O26 where Y is alkaline earth, Z is Ln, and (3) lanthanide borosilicate (Ln5BSi2O13). These three phases incorporate the waste components that are above the solubility limit of a single-phase borosilicate glass. The glass ceramic is designed to be a single phase melt, just like a borosilicate glass, and then crystallize upon slow cooling to form the targeted phases. The slow cooling schedule is based on the centerline cooling profile of a 2 foot diameter canister such as the Hanford High-Level Waste canister. Up to this point, crucible testing has been used for glass ceramic development, with cold crucible induction melter (CCIM) targeted as the ultimate processing technology for the waste form. Idaho National Laboratory (INL) will conduct a scaled CCIM test in FY2012 with a glass ceramic to demonstrate the processing behavior. This Data Package documents the laboratory studies of the glass ceramic composition to support the CCIM test. Pacific Northwest National Laboratory (PNNL) measured melt viscosity, electrical conductivity, and crystallization behavior upon cooling to identify a processing window (temperature range) for melter operation and cooling profiles necessary to crystallize the targeted phases in the

  20. Energetics of glass fragmentation: Experiments on synthetic and natural glasses

    NASA Astrophysics Data System (ADS)

    Kolzenburg, S.; Russell, J. K.; Kennedy, L. A.

    2013-11-01

    Natural silicate glasses are an essential component of many volcanic rock types including coherent and pyroclastic rocks; they span a wide range of compositions, occur in diverse environments, and form under a variety of pressure-temperature conditions. In subsurface volcanic environments (e.g., conduits and feeders), melts intersect the thermodynamically defined glass transition temperature to form glasses at elevated confining pressures and under differential stresses. We present a series of room temperature experiments designed to explore the fundamental mechanical and fragmentation behavior of natural (obsidian) and synthetic glasses (Pyrex™) under confining pressures of 0.1-100 MPa. In each experiment, glass cores are driven to brittle failure under compressive triaxial stress. Analysis of the load-displacement response curves is used to quantify the storage of energy in samples prior to failure, the (brittle) release of elastic energy at failure, and the residual energy stored in the post-failure material. We then establish a relationship between the energy density within the sample at failure and the grain-size distributions (D-values) of the experimental products. The relationship between D-values and energy density for compressive fragmentation is significantly different from relationships established by previous workers for decompressive fragmentation. Compressive fragmentation is found to have lower fragmentation efficiency than fragmentation through decompression (i.e., a smaller change in D-value with increasing energy density). We further show that the stress storage capacity of natural glasses can be enhanced (approaching synthetic glasses) through heat treatment.

  1. Database and Interim Glass Property Models for Hanford HLW Glasses

    SciTech Connect

    Hrma, Pavel R.; Piepel, Gregory F.; Vienna, John D.; Cooley, Scott K.; Kim, Dong-Sang; Russell, Renee L.

    2001-07-24

    The purpose of this report is to provide a methodology for an increase in the efficiency and a decrease in the cost of vitrifying high-level waste (HLW) by optimizing HLW glass formulation. This methodology consists in collecting and generating a database of glass properties that determine HLW glass processability and acceptability and relating these properties to glass composition. The report explains how the property-composition models are developed, fitted to data, used for glass formulation optimization, and continuously updated in response to changes in HLW composition estimates and changes in glass processing technology. Further, the report reviews the glass property-composition literature data and presents their preliminary critical evaluation and screening. Finally the report provides interim property-composition models for melt viscosity, for liquidus temperature (with spinel and zircon primary crystalline phases), and for the product consistency test normalized releases of B, Na, and Li. Models were fitted to a subset of the screened database deemed most relevant for the current HLW composition region.

  2. LUBRICATING AND SIZING AGENT FOR GLASS FIBER,

    DTIC Science & Technology

    GLASS TEXTILES, SURFACE PROPERTIES), (*LUBRICANTS, GLASS TEXTILES), FIBERS , POLYVINYL ALCOHOL, STEARATES, CHROMIUM COMPOUNDS, ALUMINUM COMPOUNDS, MIXTURES, LACTATES, TITANIUM COMPOUNDS, MECHANICAL PROPERTIES, USSR

  3. Containerless glass fiber processing

    NASA Technical Reports Server (NTRS)

    Ethridge, E. C.; Naumann, R. J.

    1986-01-01

    An acoustic levitation furnace system is described that was developed for testing the feasibility of containerless fiber pulling experiments. It is possible to levitate very dense materials such as platinum at room temperature. Levitation at elevated temperatures is much more difficult. Samples of dense heavy metal fluoride glass were levitated at 300 C. It is therefore possible that containerless fiber pulling experiments could be performed. Fiber pulling from the melt at 650 C is not possible at unit gravity but could be possible at reduced gravities. The Acoustic Levitation Furnace is described, including engineering parameters and processing information. It is illustrated that a shaped reflector greatly increases the levitation force aiding the levitation of more dense materials.

  4. Fluoride removal performance of glass derived hydroxyapatite

    SciTech Connect

    Liang, Wen; Zhan, Lei; Piao, Longhua; Russel, Christian

    2011-02-15

    Research highlights: {yields} Novel sodium calcium borate glass derived hydroxyapatite (G-HAP) is prepared. {yields} Micro-G-HAP adsorbs F{sup -} ions in solutions more effectively than commercial nano-HAP. {yields} The adsorption kinetics and isotherms are well fitted by a second order kinetic model and Freundlich isotherm model. -- Abstract: A novel sodium calcium borate glass derived hydroxyapatite (G-HAP) with different ranges of particle size was prepared by immersion sodium calcium borate glass in 0.1 M K{sub 2}HPO{sub 4} solution by the ratio of 50 g L{sup -1} for 7 days. The unique advantage of G-HAP for the adsorption of fluoride ions in solutions was studied. The effects of size and quantity of particles, pH value and adsorption time on adsorption performance were investigated. The maximum adsorption capacity was 17.34 mg g{sup -1} if 5 g L{sup -1}, <100 {mu}m G-HAP was added to a solution with an initial pH value of 6.72 and the adsorption time was 12 h. The results showed that the micro-G-HAP could immobilize F{sup -} in solution more effectively than commercial nano-HAP, which makes potential application of the G-HAP in removing the fluoride ions from wastewater. The adsorption kinetics and isotherms for F{sup -} could be well fitted by a second order kinetic model and Freundlich isotherm model respectively, which could be used to describe the adsorption behavior. The mechanism of G-HAP in immobilizing F{sup -} from aqueous solutions was investigated by the X-ray diffraction (XRD), infrared spectra (IR) and scanning electron microscopy (SEM).

  5. Glass science tutorial: Lecture No. 7, Waste glass technology for Hanford

    SciTech Connect

    Kruger, A.A.

    1995-07-01

    This paper presents the details of the waste glass tutorial session that was held to promote knowledge of waste glass technology and how this can be used at the Hanford Reservation. Topics discussed include: glass properties; statistical approach to glass development; processing properties of nuclear waste glass; glass composition and the effects of composition on durability; model comparisons of free energy of hydration; LLW glass structure; glass crystallization; amorphous phase separation; corrosion of refractories and electrodes in waste glass melters; and glass formulation for maximum waste loading.

  6. [Some glass instruments of Arabic alchemy].

    PubMed

    Kurzmann, Peter

    2009-01-01

    From an as yet unpublished collection, kept in the Linden Museum, Stuttgart, of some 20 Islamic glass items, 12 objects with an alchemical background have been selected and studied in detail. The most important items are two alchemical still heads which, according to an alchemical manuscript of al-Kindī, a significant 9th century Arabian philosopher, natural scientist, mathematician, physician and musician, are identified as still heads for the watersteam distillation of camphor in particular. Additionally the publication presented here features a medical utensil (probably recent), a measuring jug, a funnel, a mortar, a pestle, a test tube most probably 19th century and four small bottles--probably for perfume. Most of the objects originate in Iran, but some are from Egypt, Afghanistan and Palestine and date mainly from the 9th to the 13th century AD. Some misinterpretations and ambiguities to be found in the literature have been corrected and eliminated.

  7. Glass ceramic toughened with tetragonal zirconia

    DOEpatents

    Keefer, Keith D.; Michalske, Terry A.

    1986-01-01

    A phase transformation-toughened glass ceramic and a process for making it are disclosed. A mixture of particulate network-forming oxide, network-modifying oxide, and zirconium oxide is heated to yield a homogeneous melt, and this melt is then heat-treated to precipitate an appreciable quantity of tetragonal zirconia, which is retained at ambient temperature to form a phase transformation-toughened glass ceramic. Nucleating agents and stabilizing agents may be added to the mixture to facilitate processing and improve the ceramic's properties. Preferably, the mixture is first melted at a temperature from 1200.degree. to 1700.degree. C. and is then heat-treated at a temperature within the range of 800.degree. to 1200.degree. C. in order to precipitate tetragonal ZrO.sub.2. The composition, as well as the length and temperature of the heat-treatment, must be carefully controlled to prevent solution of the precipitated tetragonal zirconia and subsequent conversion to the monoclinic phase.

  8. Stability of charged global AdS4 spacetimes

    NASA Astrophysics Data System (ADS)

    Arias, Raúl; Mas, Javier; Serantes, Alexandre

    2016-09-01

    We study linear and nonlinear stability of asymptotically AdS4 solutions in Einstein-Maxwell-scalar theory. After summarizing the set of static solutions we first examine thermodynamical stability in the grand canonical ensemble and the phase transitions that occur among them. In the second part of the paper we focus on nonlinear stability in the microcanonical ensemble by evolving radial perturbations numerically. We find hints of an instability corner for vanishingly small perturbations of the same kind as the ones present in the uncharged case. Collapses are avoided, instead, if the charge and mass of the perturbations come to close the line of solitons. Finally we examine the soliton solutions. The linear spectrum of normal modes is not resonant and instability turns on at extrema of the mass curve. Linear stability extends to nonlinear stability up to some threshold for the amplitude of the perturbation. Beyond that, the soliton is destroyed and collapses to a hairy black hole. The relative width of this stability band scales down with the charge Q, and does not survive the blow up limit to a planar geometry.

  9. AdS4/CFT3 squashed, stretched and warped

    NASA Astrophysics Data System (ADS)

    Klebanov, Igor R.; Klose, Thomas; Murugan, Arvind

    2009-03-01

    We use group theoretic methods to calculate the spectrum of short multiplets around the extremum of Script N = 8 gauged supergravity potential which possesses Script N = 2 supersymmetry and SU(3) global symmetry. Upon uplifting to M-theory, it describes a warped product of AdS4 and a certain squashed and stretched 7-sphere. We find quantum numbers in agreement with those of the gauge invariant operators in the Script N = 2 superconformal Chern-Simons theory recently proposed to be the dual of this M-theory background. This theory is obtained from the U(N) × U(N) theory through deforming the superpotential by a term quadratic in one of the superfields. To construct this model explicitly, one needs to employ monopole operators whose complete understanding is still lacking. However, for the U(2) × U(2) gauge theory we make a proposal for the form of the monopole operators which has a number of desired properties. In particular, this proposal implies enhanced symmetry of the U(2) × U(2) ABJM theory for k = 1,2; it makes its similarity to and subtle difference from the BLG theory quite explicit.

  10. The ADS All Sky Survey

    NASA Astrophysics Data System (ADS)

    Goodman, Alyssa

    We will create the first interactive sky map of astronomers' understanding of the Universe over time. We will accomplish this goal by turning the NASA Astrophysics Data System (ADS), widely known for its unrivaled value as a literature resource, into a data resource. GIS and GPS systems have made it commonplace to see and explore information about goings-on on Earth in the context of maps and timelines. Our proposal shows an example of a program that lets a user explore which countries have been mentioned in the New York Times, on what dates, and in what kinds of articles. By analogy, the goal of our project is to enable this kind of exploration-on the sky-for the full corpus of astrophysical literature available through ADS. Our group's expertise and collaborations uniquely position us to create this interactive sky map of the literature, which we call the "ADS All-Sky Survey." To create this survey, here are the principal steps we need to follow. First, by analogy to "geotagging," we will "astrotag," the ADS literature. Many "astrotags" effectively already exist, thanks to curation efforts at both CDS and NED. These efforts have created links to "source" positions on the sky associated with each of the millions of articles in the ADS. Our collaboration with ADS and CDS will let us automatically extract astrotags for all existing and future ADS holdings. The new ADS Labs, which our group helps to develop, includes the ability for researchers to filter article search results using a variety of "facets" (e.g. sources, keywords, authors, observatories, etc.). Using only extracted astrotags and facets, we can create functionality like what is described in the Times example above: we can offer a map of the density of positions' "mentions" on the sky, filterable by the properties of those mentions. Using this map, researchers will be able to interactively, visually, discover what regions have been studied for what reasons, at what times, and by whom. Second, where

  11. Glass ceramic seals to inconel

    DOEpatents

    McCollister, Howard L.; Reed, Scott T.

    1983-11-08

    A glass ceramic composition prepared by subjecting a glass composition comprising, by weight, 65-80% SiO.sub.2, 8-16%, Li.sub.2 O, 2-8% , Al.sub.2 O.sub.3, 1-8% K.sub.2 O, 1-5% P.sub.2 O.sub.5 and 1.5-7% B.sub.2 O.sub.3, to the following processing steps of heating the glass composition to a temperature sufficient to crystallize lithium metasilicate therein, holding the glass composition at a temperature and for a time period sufficient to dissolve the lithium metasilicate therein thereby creating cristobalite nucleii, cooling the glass composition and maintaining the composition at a temperature and for a time period sufficient to recrystallize lithium metasilicate therein, and thermally treating the glass composition at a temperature and for a time period sufficient to cause growth of cristobalite and further crystallization of lithium metasilicate producing a glass ceramic composition having a specific thermal expansion coefficient and products containing said composition.

  12. Fracture mechanics of cellular glass

    SciTech Connect

    Zwissler, J.G.; Adams, M.A.

    1981-02-01

    Cellular glasses are prime candidate materials for the structural substrate of mirrored glass for solar concentrator reflecting panels. These materials are brittle, however, and susceptible to mechanical failure from slow crack growth caused by a stress corrosion mechanism. The results are detailed of one part of a program established to develop improved cellular glasses and to characterize the behavior of these and commercially available materials. Commercial and developmental cellular glasses were tested and analyzed using standard testing techniques and models developed from linear fracture mechanics. Two models describing the fracture behavior of these materials are developed. Slow crack growth behavior in cellular glass was found to be more complex than that encountered in dense glasses or ceramics. The crack velocity was found to be strongly dependent upon water vapor transport to the tip of the moving crack. The existence of a static fatigue limit was not conclusively established, however, it is speculated that slow crack growth behavior in Region I may be slower, by orders of magnitude, than that found in dense glasses.

  13. [Respiratory function in glass blowers].

    PubMed

    Zuskin, E; Butković, D; Mustajbegović, J

    1992-01-01

    The prevalence of chronic and acute respiratory symptoms and diseases and changes in lung function in a group of 80 glass blowers have been investigated. In addition a group of 80 not exposed workers was used as a control group for respiratory symptoms and diseases. In glass blowers, there was significant increase in prevalence of chronic bronchitis, nasal catarrh, and sinusitis than in the controls. Glass blowers exposed for more and less than 10 years had similar prevalences of respiratory symptoms. A large number of glass blowers complained of acute across-shift symptoms. Significant increase in FVC, FEF50 and FEF25 was documented at the end of the work shift. Comparison with predicted normal values showed that glass blowers had FVC and FEF25 significantly lower than predicted. RV and RV/TLC were significantly increased compared with the predicted normal values. DLCO was within the normal values in most glass blowers. It is concluded that work in the glass blower industry is likely to lead the development of chronic respiratory disorders.

  14. Glass Ceramic Waste Forms for Combined CS+LN+TM Fission Products Waste Streams

    SciTech Connect

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

    2010-09-23

    In this study, glass ceramics were explored as an alternative waste form for glass, the current baseline, to be used for immobilizing alkaline/alkaline earth + lanthanide (CS+LN) or CS+LN+transition metal (TM) fission-product waste streams generated by a uranium extraction (UREX+) aqueous separations type process. Results from past work on a glass waste form for the combined CS+LN waste streams showed that as waste loading increased, large fractions of crystalline phases precipitated upon slow cooling.[1] The crystalline phases had no noticeable impact on the waste form performance by the 7-day product consistency test (PCT). These results point towards the development of a glass ceramic waste form for treating CS+LN or CS+LN+TM combined waste streams. Three main benefits for exploring glass ceramics are: (1) Glass ceramics offer increased solubility of troublesome components in crystalline phases as compared to glass, leading to increased waste loading; (2) The crystalline network formed in the glass ceramic results in higher heat tolerance than glass; and (3) These glass ceramics are designed to be processed by the same melter technology as the current baseline glass waste form. It will only require adding controlled canister cooling for crystallization into a glass ceramic waste form. Highly annealed waste form (essentially crack free) with up to 50X lower surface area than a typical High-Level Waste (HLW) glass canister. Lower surface area translates directly into increased durability. This was the first full year of exploring glass ceramics for the Option 1 and 2 combined waste stream options. This work has shown that dramatic increases in waste loading are achievable by designing a glass ceramic waste form as an alternative to glass. Table S1 shows the upper limits for heat, waste loading (based on solubility), and the decay time needed before treatment can occur for glass and glass ceramic waste forms. The improvements are significant for both combined waste

  15. Glass Frit Clumping And Dusting

    SciTech Connect

    Steimke, J. L.

    2013-09-26

    DWPF mixes a slurry of glass frit (Frit 418) and dilute (1.5 wt%) formic acid solution with high level waste in the Slurry Mix Evaporator (SME). There would be advantages to introducing the frit in a non-slurry form to minimize water addition to the SME, however, adding completely dry frit has the potential to generate dust which could clog filters or condensers. Prior testing with another type of frit, Frit 320, and using a minimal amount of water reduced dust generation, however, the formation of hard clumps was observed. To examine options and behavior, a TTQAP [McCabe and Stone, 2013] was written to initiate tests that would address these concerns. Tests were conducted with four types of glass frit; Frit 320, DWPF Frit 418, Bekeson Frit 418 and Multi-Aspirator Frit 418. The last two frits are chemically identical to DWPF Frit 418 but smaller particles were removed by the respective vendors. Test results on Frit Clumping and Dusting are provided in this report. This report addresses the following seven questions. Short answers are provided below with more detailed answers to follow. 1. Will the addition of a small amount of water, 1.5 wt%, to dry DWPF Frit 418 greatly reduce the dust generation during handling at DWPF? a. Yes, a small scale test showed that adding a little water to the frit greatly reduced dust generation during handling. 2. Will the addition of small amounts of water to the frit cause clumping that will impair frit handling at DWPF? a. No, not with Frit 418. Although clumps were observed to form when 1.5 wt% water was mixed with DWPF Frit 418, then compressed and air-dried overnight, the clumps were easily crushed and did not form the hardened material noted when Frit 320 was tested. 3. What is the measured size distribution of dust generated when dry frit is handled? (This affects the feasibility and choice of processing equipment for removing the dust generating fraction of the frit before it is added to the SME.) a. The size distribution for

  16. Glass microspheres for medical applications

    NASA Astrophysics Data System (ADS)

    Conzone, Samuel David

    Radioactive dysprosium lithium borate glass microspheres have been developed as biodegradable radiation delivery vehicles for the radiation synovectomy treatment of rheumatoid arthritis. Once injected into a diseased joint, the microspheres deliver a potent dose of radiation to the diseased tissue, while a non-uniform chemical reaction converts the glass into an amorphous, porous, hydrated dysprosium phosphate reaction product. The non-radioactive, lithium-borate component is dissolved from the glass (up to 94% weight loss), while the radioactive 165Dy reacts with phosphate anions in the body fluids, and becomes "chemically" trapped in a solid, dysprosium phosphate reaction product that has the same size as the un-reacted glass microsphere. Ethylene diamine tetraacetate (EDTA) chelation therapy can be used to dissolve the dysprosium phosphate reaction product after the radiation delivery has subsided. The dysprosium phosphate reaction product, which formed in vivo in the joint of a Sprague-Dawley rat, was dissolved by EDTA chelation therapy in <1 week, without causing any detectable joint damage. The combination of dysprosium lithium borate glass microspheres and EDTA chelation therapy provides an unique "tool" for the medical community, which can deliver a large dose (>100 Gy) of localized beta radiation to a treatment site within the body, followed by complete biodegradability. The non-uniform reaction process is a desirable characteristic for a biodegradable radiation delivery vehicle, but it is also a novel material synthesis technique that can convert a glass to a highly porous materials with widely varying chemical composition by simple, low-temperature, glass/solution reaction. The reaction product formed by nonuniform reaction occupies the same volume as the un-reacted glass, and after drying for 1 h at 300°C, has a specific surface area of ≈200 m2/g, a pore size of ≈30 nm, and a nominal crushing strength of ≈10 MPa. Finally, rhenium glass

  17. Zirconia solubility in boroaluminosilicate glass

    SciTech Connect

    Raman, S.V.; Bopp, R.; Batcheller, T.A.; Yan, Q.

    1995-12-31

    In the Idaho Chemical Processing Plant (ICPP) waste streams, zirconia is often the waste load limiting species. It modifies the glass network, enhances durability, increases viscosity and induces crystallization. The limits of its dissolution in boroaluminosilicate glass, with magnesia and soda additions were experimentally determined. A ternary compositional surface is evolved to present the isothermal regimes of liquid, liquid + zircon, liquid + forsterite, and liquid phase sintered ceramic. The potential of partitioning the transuranics, transition elements and solutes in these regimes is discussed. The visible Raman spectroscopic results are presented to elucidate the dependence among glass composition, structure and chemical durability.

  18. Method for manufacturing glass frit

    DOEpatents

    Budrick, Ronald G.; King, Frank T.; Nolen, Jr., Robert L.; Solomon, David E.

    1977-01-01

    A method of manufacturing a glass frit for use in the manufacture of uniform glass microspheres to serve as containers for laser fusion fuel to be exposed to laser energy which includes the formation of a glass gel which is then dried, pulverized, and very accurately sized to particles in a range of, for example, 125 to 149 micrometers. The particles contain an occluded material such as urea which expands when heated. The sized particles are washed, dried, and subjected to heat to control the moisture content prior to being introduced into a system to form microspheres.

  19. Recent developments in laser glasses

    SciTech Connect

    Weber, M.J.

    1983-01-10

    The past decade has witnessed a proliferation of new glass-forming compositions including oxides, halides, oxyhalides, and chalcogenides. Many of these glasses are applicable to lasers and have greatly expanded the range of optical properties and spectroscopic parameters available to the laser designer. Our knowledge and understanding of many properties of interest for laser action - transparency, linear and nonlinear refractive indices, and damage threshold of the host glass and the absorption spectrum, radiative and nonradiative transition probabilities, fluorescence wavelength, stimulated emission cross section, and spectroscopic inhomogeneities of the lasing ion Nd/sup 3 +/ - are reviewed.

  20. The inside outs of AdS3/CFT2: exact AdS wormholes with entangled CFT duals

    NASA Astrophysics Data System (ADS)

    Mandal, Gautam; Sinha, Ritam; Sorokhaibam, Nilakash

    2015-01-01

    We present the complete family of solutions of 3D gravity (Λ < 0) with two asymptotically AdS exterior regions. The solutions are constructed from data at the two boundaries, which correspond to two independent and arbitrary stress tensors T R , , and T L , . The two exteriors are smoothly joined on to an interior region through a regular horizon. We find CFT duals of these geometries which are entangled states of two CFT's. We compute correlators between general operators at the two boundaries and find perfect agreement between CFT and bulk calculations. We calculate and match the CFT entanglement entropy (EE) with the holographic EE which involves geodesics passing through the wormhole. We also compute a holographic, non-equilibrium entropy for the CFT using properties of the regular horizon. The construction of the bulk solutions here uses an exact version of Brown-Henneaux type diffeomorphisms which are asymptotically nontrivial and transform the CFT states by two independent unitary operators on the two sides. Our solutions provide an infinite family of explicit examples of the ER=EPR relation of Maldacena and Susskind [1].

  1. Galactic Hearts of Glass

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Click on image for larger graph

    This artist's concept shows delicate greenish crystals sprinkled throughout the violent core of a pair of colliding galaxies. The white spots represent a thriving population of stars of all sizes and ages. NASA's Spitzer Space Telescope detected more than 20 bright and dusty galactic mergers like the one depicted here, all teeming with the tiny gem-like crystals.

    When galaxies collide, they trigger the birth of large numbers of massive stars. Astronomers believe these blazing hot stars act like furnaces to produce silicate crystals in the same way that glass is made from sand. The stars probably shed the crystals as they age, and as they blow apart in supernovae explosions.

    At the same time the crystals are being churned out, they are also being destroyed. Fast-moving particles from supernova blasts easily convert silicates crystals back to their amorphous, or shapeless, form.

    How is Spitzer seeing the crystals if they are rapidly disappearing? Astronomers say that, for a short period of time at the beginning of galactic mergers, massive stars might be producing silicate crystals faster than they are eliminating them. When our own galaxy merges with the Andromeda galaxy in a few billion years, a similar burst of massive stars and silicate crystals might occur.

    Crystal Storm in Distant Galaxy The graph (see inset above) of infrared data from NASA's Spitzer Space Telescope tells astronomers that a distant galaxy called IRAS 08752+3915 is experiencing a storm of tiny crystals made up of silicates. The crystals are similar to the glass-like grains of sand found on Earth's many beaches.

    The data were taken by Spitzer's infrared spectrograph, which splits light open to reveal its rainbow-like components. The resulting spectrum shown here reveals the signatures of both crystalline (green) and non-crystalline (brown) silicates.

    Spitzer detected the same

  2. Comparative Evaluation of the Antimicrobial Properties of Glass Ionomer Cements with and without Chlorhexidine Gluconate

    PubMed Central

    Jampanapalli, Sharada Reddy; Konda, Suhasini; Inguva, Hema Chandrika; Chimata, Vamsi Krishna

    2016-01-01

    ABSTRACT Background: Chlorhexidine gluconate is a widely used antimicrobial agent. Adding chlorhexidine and quaternary ammonium compounds to filling materials, such as composite resins, acrylic resins, and glass ionomer cements increases the antibacterial property of restorative materials. This study includes antibacterial property of glass ionomer restorative cements with chlorhexidine gluconate. Aim: The primary objective of our study was to compare the antimicrobial properties of two commercially available glass ionomer cements with and without chlorhexidine gluconate on strains of mutans streptococci. Materials and methods: Two glass ionomers (Fuji II Conventional and Fuji IX) were used. Chlorhexidine gluconate was mixed with glass ionomer cements, and antimicrobial properties against mutans streptococci were assessed by agar diffusion. The tested bacterial strain was inhibited and the antimicrobial properties decreased with time. Results: The highest amount of antimicrobial activity with mean inhibitory zone was found in Fuji II with chlorhexidine gluconate followed by Fuji IX with chlorhexidine gluconate, Fuji II without chlorhexidine gluconate, and Fuji IX without chlorhexidine gluconate. Conclusion: The results of the study confirmed that the addition of 5% chlorhexidine gluconate to Fuji II and Fuji IX glass ionomer cements resulted in a restorative material that had increased antimicrobial properties over the conventional glass ionomer cements alone for Streptococcus mutans. How to cite this article: Yadiki JV, Jampanapalli SR , Konda S, Inguva HC, Chimata VK. Comparative Evaluation of the Antimicrobial Properties of Glass Ionomer Cements with and without Chlorhexidine Gluconate. Int J Clin Pediatr Dent 2016;9(2):99-103. PMID:27365927

  3. [The production of optical glass in France and the experiences of Ruggiero Boscovich for the production of lead glass (Part One)].

    PubMed

    Proverbio, Edoardo

    The experiences that in 1758 led John Dollond to create the first achromatic telescope highlighted the serious difficulties related to the production of lenses with a correction for chromatic aberration. These difficulties were due to the lack of suitable tools for measuring the refraction index and for verifying the curvatures of the lenses of such optical instruments. To this was added what was perhaps the greatest difficulty: i.e., that of acquiring the kinds of glass, the so-called "common" (crown) glass and "lead" (flint) glass, of which the lenses had to be made. If the theoretical works of Alexis Clairaut, of Samuel Klingenstierna, and of Ruggiero Boscovich furnished the theoretical basis for producing such lenses, and subsequently--after Boscovich's discovery of the role of the eyepieces--for creating also achromatic eyepieces, the greatest challenge from the practical point of view was that of the availability of the flint glass. In this first part of the article there is then a study of the numerous attempts and directions pursued by Clairaut and his valid collaborators--Anthéaulme, George father and son, Charles François de l'Etang, and Claude Siméon Passemant--in order to find common glass and lead glass, and to produce the first achromatic lenses and binoculars in France. An analysis follows of the experiences conducted by Boscovich, first in Vienna, and then in Milan and Venice-Murano, addressed to the production of flint glass.

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

    SciTech Connect

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

    2007-05-09

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

  5. Leaching Tc-99 from SRP glass in simulated tuff and salt groundwaters

    SciTech Connect

    Bibler, N E; Jurgensen, A R

    1987-01-01

    Results of leach tests with Tc-99 doped SRP borosilicate waste glass are presented. The glass was prepared by melting a mixture of SRP 165 powdered frit doped with a carrier free solution of Tc-99 at 1150{sup 0}C. Dissolution of portions of the resulting glass indicated that the Tc-99 was distributed homogeneously throughout the glass. Static leach tests up to 90 days were performed at 90{sup 0}C in J-13 tuff groundwater or WIPP brine A at a SA/V of 100m{sup -1}. Normalized mass losses were calculated for Tc-99 as well as all the major elements in the glass. Results indicated that under ambient oxidizing conditions Tc-99 leached no faster than the glass-forming elements of the glass. In J-13 water, Tc-99 leached congruently with B. In WIPP brine A, it leached congruently with Si. Leach rates for Li were higher in both groundwaters, probably due to a contribution from an ion exchange mechanism. Leach tests were performed under reducing conditions in J-13 water by adding Zn/Hg amalgam to the leachate. In these tests the pH increased significantly, probably because of the reaction of the amalgam with the water. In a 21-day test, the pH increased to 13 and leach rates for the glass were very high. Even though there was signifcant dissolution of the glass, the normalized mass loss based on Tc-99 was only 0.02g/m{sup 2}. This result and the fact that reducing conditions at normal pH values do not significantly affect the dissolution of the glass, indicate that the low concentrations for Tc-99 obtained under reducing conditions are due to is solubility and not due to an increased durability of the glass. 14 refs., 2 figs., 5 tabs.

  6. 7 CFR 2902.30 - Glass cleaners.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 15 2011-01-01 2011-01-01 false Glass cleaners. 2902.30 Section 2902.30 Agriculture... Glass cleaners. (a) Definition. Cleaning products designed specifically for use in cleaning glass... qualifying biobased glass cleaners. By that date, Federal agencies that have the responsibility for...

  7. EVA-glass interface bond stability

    NASA Technical Reports Server (NTRS)

    Koenig, J. L.

    1984-01-01

    The ethylene vinyl acetate/glass interface bond stability was investigated. Special methods to determine the structure of polymer/glass interface were developed. Structural changes related to hydrothermal degradation of polymer/glass interface are examined. Methods to inhibit the degradation reaction which occur at polymer/glass interface are developed.

  8. Synthesis and Crystallization Behavior of Fluoride Glasses

    DTIC Science & Technology

    1989-08-22

    metal fluoride glasses. Exploration of synthesis conditions for converting precursors to multicomponent oxide gels for conversion to heavy metal fluoride...glasses. Exploration of chemistries and conditions for converting multicomponent oxide gels to heavy metal fluoride glasses. Exploration of...chemical approaches to passivating the surfaces of heavy metal fluoride glasses. Exploration of the possibility of developing a computer model to describe

  9. 7 CFR 2902.30 - Glass cleaners.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Glass cleaners. 2902.30 Section 2902.30 Agriculture... Glass cleaners. (a) Definition. Cleaning products designed specifically for use in cleaning glass... qualifying biobased glass cleaners. By that date, Federal agencies that have the responsibility for...

  10. Properties Of Soda/Yttria/Silica Glasses

    NASA Technical Reports Server (NTRS)

    Angel, Paul W.; Hann, Raiford E.

    1994-01-01

    Experimental study of glass-formation compositional region of soda/ yttria/silicate system and of selected physical properties of glasses within compositional region part of continuing effort to identify glasses with high coefficients of thermal expansion and high softening temperatures, for use as coatings on superalloys and as glass-to-metal seals.

  11. Apollo applications of beta fiber glass

    NASA Technical Reports Server (NTRS)

    Naimer, J.

    1971-01-01

    The physical characteristics of Beta fiber glass are discussed. The application of Beta fiber glass for fireproofing the interior of spacecraft compartments is described. Tests to determine the flammability of Beta fiber glass are presented. The application of Beta fiber glass for commercial purposes is examined.

  12. Kinetics of the glass transition of fragile soft colloidal suspensions.

    PubMed

    Saha, Debasish; Joshi, Yogesh M; Bandyopadhyay, Ranjini

    2015-12-07

    Microscopic relaxation time scales are estimated from the autocorrelation functions obtained by dynamic light scattering experiments for Laponite suspensions with different concentrations (CL), added salt concentrations (CS), and temperatures (T). It has been shown in an earlier work [D. Saha, Y. M. Joshi, and R. Bandyopadhyay, Soft Matter 10, 3292 (2014)] that the evolutions of relaxation time scales of colloidal glasses can be compared with molecular glass formers by mapping the waiting time (tw) of the former with the inverse of thermodynamic temperature (1/T) of the latter. In this work, the fragility parameter D, which signifies the deviation from Arrhenius behavior, is obtained from fits to the time evolutions of the structural relaxation time scales. For the Laponite suspensions studied in this work, D is seen to be independent of CL and CS but is weakly dependent on T. Interestingly, the behavior of D corroborates the behavior of fragility in molecular glass formers with respect to equivalent variables. Furthermore, the stretching exponent β, which quantifies the width w of the spectrum of structural relaxation time scales, is seen to depend on tw. A hypothetical Kauzmann time tk, analogous to the Kauzmann temperature for molecular glasses, is defined as the time scale at which w diverges. Corresponding to the Vogel temperature defined for molecular glasses, a hypothetical Vogel time tα (∞) is also defined as the time at which the structural relaxation time diverges. Interestingly, a correlation is observed between tk and tα (∞), which is remarkably similar to that known for fragile molecular glass formers. A coupling model that accounts for the tw-dependence of the stretching exponent is used to analyse and explain the observed correlation between tk and tα (∞).

  13. Kinetics of the glass transition of fragile soft colloidal suspensions

    NASA Astrophysics Data System (ADS)

    Saha, Debasish; Joshi, Yogesh M.; Bandyopadhyay, Ranjini

    2015-12-01

    Microscopic relaxation time scales are estimated from the autocorrelation functions obtained by dynamic light scattering experiments for Laponite suspensions with different concentrations (CL), added salt concentrations (CS), and temperatures (T). It has been shown in an earlier work [D. Saha, Y. M. Joshi, and R. Bandyopadhyay, Soft Matter 10, 3292 (2014)] that the evolutions of relaxation time scales of colloidal glasses can be compared with molecular glass formers by mapping the waiting time (tw) of the former with the inverse of thermodynamic temperature (1/T) of the latter. In this work, the fragility parameter D, which signifies the deviation from Arrhenius behavior, is obtained from fits to the time evolutions of the structural relaxation time scales. For the Laponite suspensions studied in this work, D is seen to be independent of CL and CS but is weakly dependent on T. Interestingly, the behavior of D corroborates the behavior of fragility in molecular glass formers with respect to equivalent variables. Furthermore, the stretching exponent β, which quantifies the width w of the spectrum of structural relaxation time scales, is seen to depend on tw. A hypothetical Kauzmann time tk, analogous to the Kauzmann temperature for molecular glasses, is defined as the time scale at which w diverges. Corresponding to the Vogel temperature defined for molecular glasses, a hypothetical Vogel time tα ∞ is also defined as the time at which the structural relaxation time diverges. Interestingly, a correlation is observed between tk and tα ∞ , which is remarkably similar to that known for fragile molecular glass formers. A coupling model that accounts for the tw-dependence of the stretching exponent is used to analyse and explain the observed correlation between tk and tα ∞ .

  14. Fiber glass pulling. [in space

    NASA Technical Reports Server (NTRS)

    Workman, Gary L.

    1987-01-01

    Experiments were conducted to determine the viability of performing containerless glass fiber pulling in space. The optical transmission properties and glass-forming capabilities of the heavy metal fluorides are reviewed and the acoustic characteristics required for a molten glass levitation system are examined. The design limitations of, and necessary modifications to the acoustic levitation furnace used in the experiments are discussed in detail. Acoustic levitator force measurements were performed and a thermal map of the furnace was generated from thermocouple data. It was determined that the thermal capability of the furnace was inadequate to melt a glass sample in the center. The substitution of a 10 KW carbon monoxide laser for the original furnace heating elements resulted in improved melt heating.

  15. Inorganic glass ceramic slip rings

    NASA Technical Reports Server (NTRS)

    Glossbrenner, E. W.; Cole, S. R.

    1972-01-01

    Prototypes of slip rings have been fabricated from ceramic glass, a material which is highly resistant to deterioration due to high temperature. Slip ring assemblies were not structurally damaged by mechanical tests and performed statisfactorily for 200 hours.

  16. 2012 Problem 13: Misty Glass

    NASA Astrophysics Data System (ADS)

    Huang, Shan; Li, Xiao; Gao, Wenli; Zhou, Huijun

    2015-10-01

    Based on diffraction theory, we propose a model to explain the formation of colorful rings created by a misty glass. The model is verified by examining the relation between the size of the ring and size of the droplets.

  17. Fluoride Glass Fibres For Telecommunications

    NASA Astrophysics Data System (ADS)

    Maze, Gwenael; Cardin, Vincent; Poulain, Marcel

    1983-09-01

    Zirconium fluoride glasses are the best known and the most stable beryllium-free glasses. They offer numerous potential uses for I.R.-transmitting fibres and ultra-long repeaterless optical wave-guides. Various problems arise in the manufacturing of fluoride glass fibres, essentially because of the steep viscosity profile and the devitrification phenomena. This paper discusses the processes for manufacturing step-index preforms and for drawing fibres. Optical quality preforms have been obtained and fibres have been drawn over more than 1 km. A spectral loss measurement system has been constructed using fluoride glass optical components. Several curves showing the optical attenuation versus wavelength are presented and discussed. These fibres are now available for optical transmission in infra-red systems.

  18. All-glass solar collector

    NASA Technical Reports Server (NTRS)

    Wisnewski, J. P.

    1980-01-01

    Proposed all tempered glass solar collector uses black collection fluid and mirrored bottom to reduce energy loss and overall costs associated with conventional collectors. Collector is more efficient and practically maintenance-free.

  19. High Tech Art: Chameleon Glass

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Dichroic Glass is a technology wherein extremely thin films of metal are vacuum deposited on a glass surface. The coated glass shields spacecraft instruments from cosmic radiation and protects human vision from unfiltered sunlight in space. Because the coating process allows some wavelengths of light and color to reflect and others to pass through, a chameleon effect is produced. Murray Schwartz, a former aerospace engineer, has based his business KROMA on this NASA optical technology. He produces dichroic stained glass windows, mobiles and jewelry. The technique involves deposition of super thin layers of metal oxides applied one layer at a time in a specific order and thickness for the desired effect. His product line is unique and has been very successful.

  20. Glass-formers vs. Assemblers

    NASA Astrophysics Data System (ADS)

    Glotzer, Sharon

    2015-03-01

    In most instances, the formation of a glass signifies an inability of the constituents of a system to self-organize into a well-defined, thermodynamically preferred ordered structure. Thus good ''assemblers'' may make poor glass-formers, and good glass-formers tend to be poor assemblers. How good or bad a system is in assembling or vitrifying/jamming depends on many features of the constituent building blocks, including shape and interactions. In many cases, building blocks whose shapes make them good glass-formers can, through almost imperceptible perturbations, become good assemblers, and vice versa. We examine these issues through consideration of several model systems, including colloidal ''rocks'' and foldable nets. *with E.R. Chen, P. Damasceno, P. Dodd, M. Engel, A.S. Keys, D. Klotsa, E. Teich, and G. van Anders

  1. Fast Crystals and Strong Glasses

    SciTech Connect

    Weitz, David

    2009-11-04

    This talk describes new results on model colloid systems that provide insight into the behavior of fundamental problems in colloid physics, and more generally, for other materials as well. By visualizing the nucleation and growth of colloid crystals, we find that the incipient crystallites are much more disordered than expected, leading to a larger diversity of crystal morphologies. When the entropic contribution of these diverse morphologies is included in the free energy, we are able to describe the behavior very well, and can predict the nucleation rate surprisingly accurately. The talk also describes the glass transition in deformable colloidal particles, and will show that when the internal elasticity of the particles is included, the colloidal glass transition mimics that of molecular glass formers much more completely. These results also suggest that the elasticity at the scale of the fundamental unit, either colloid particle or molecule, determines the nature of the glass transition, as described by the "fragility."

  2. Injuring potential of drinking glasses.

    PubMed

    Sterzik, Vera; Kneubuehl, Beat P; Ropohl, Dirk; Bohnert, Michael

    2008-08-06

    At a party of a sports club, an argument started between two groups of young men, in the course of which one of the persons involved threw a beer glass hitting a young man of the other group, who collapsed with a profusely bleeding wound. Although resuscitation measures were initiated immediately, the victim died at the scene due to exsanguination from the completely severed left external carotid artery in combination with the aspiration of blood. Tests with drinking glasses thrown at a skull-neck model suggested that an undamaged beer glass thrown at the head of the victim could not cause the fatal injuries on the neck because of its splintering behaviour. In fact, it seemed that the beer glass had been damaged prior to throwing it and that its sharp edges perforated the skin on hitting the neck.

  3. Surface reactions of natural glasses

    SciTech Connect

    White, A.F.

    1986-12-31

    Reactions at natural glass surfaces are important in studies involving nuclear waste transport due to chemical control on ground water in host rocks such as basalt and tuff, to potential diffusion into natural hydrated glass surfaces and as natural analogs for waste glass stability. Dissolution kinetics can be described by linear surface reaction coupled with cation interdiffusion with resulting rates similar to those of synthetic silicate glasses. Rates of Cs diffusion into hydrated obsidian surfaces between 25{sup 0} and 75{sup 0}C were determined by XPS depth profiles and loss rates from aqueous solutions. Calculated diffusion coefficients were ten others of magnitude more rapid than predicted from an Arrhenius extrapolation of high temperature tracer diffusion data due to surface hydration reactions.

  4. Turning nuclear waste into glass

    SciTech Connect

    Pegg, Ian L.

    2015-02-15

    Vitrification has emerged as the treatment option of choice for the most dangerous radioactive waste. But dealing with the nuclear waste legacy of the Cold War will require state-of-the-art facilities and advanced glass formulations.

  5. TiO2 effect on crystallization mechanism and physical properties of nano glass-ceramics of MgO-Al2O3-SiO2 glass system.

    PubMed

    Jo, Sinae; Kang, Seunggu

    2013-05-01

    The effect of TiO2 on the degree of crystallization, thermal properties and microstructure for MgO-Al2O3-SiO2 glass-ceramics system containing 0-13 wt% TiO2 and 0-1.5 wt% B2O3 in which the cordierite is the main phase was studied. Using Kissinger and Augis-Bennett equations, the activation energy, 510 kJ/mol and Avrami constant, 1.8 were calculated showing the surface-oriented crystallization would be preferred. The alpha-cordierite phase was generated in the glass-ceramics of containing TiO2 of 0-5.6 wt%. However, for the glass-ceramics of TiO2 content above 7 wt%, an alpha-cordierite disappeared and micro-cordierite phase was formed. The glass-ceramics of no TiO2 added had spherical crystals of few tens nanometer size spread in the matrix. As TiO2 content increased up to 5.6 wt%, a lump of dendrite was formed. In the glass-ceramics containing TiO2 7-13 wt%, in which the main phase is micro-cordierite, the dendrite crystal disappeared and a few hundred nanometer sized crystal particles hold tightly each other were generated. The thermal conductivity of glass-ceramics of both a-cordierite and micro-cordierite base decreased with TiO2 contend added. The thermal conductivity of glass-ceramics of 1.5 wt% TiO2 added was 3.4 W/mK which is 36% higher than that of glass-ceramics of no TiO2 added. The sintering temperature for 1.5 wt% TiO2 glass-ceramics was 965 degrees C which could be concluded as to apply to LTCC process for LED packaging.

  6. Driving bubbles out of glass

    NASA Technical Reports Server (NTRS)

    Mattox, D. M.

    1981-01-01

    Surface tension gradient in melt forces gas bubbles to surface, increasing glass strength and transparency. Conventional chemical and buoyant fining are extremely slow in viscous glasses, but tension gradient method moves 250 um bubbles as rapidly as 30 um/s. Heat required for high temperature part of melt is furnished by stationary electrical or natural-gas heater; induction and laser heating are also possible. Method has many applications in industry processes.

  7. Multimegajoule laser design. [Glass lasers

    SciTech Connect

    Manes, K.R.; Ozarski, R.G.; Hagen, W.F.; Holzrichtr, J.F.

    1985-08-01

    New technologies make multimegajoule glass lasers economically feasible. We have devised new laser architectures using harmonic switchout, target-plane holographic injection, phase conjugation, continuous apodization, and higher amplifier efficiencies. Our plan for building a multimegajoule laser for a recurring cost under $300 million relies on the following manufacturing economies of scale: high-volume glass production, rapid harmonic-crystal growth, capacitor sizing and packing to increase energy capacity, and part standardization.

  8. Luminescence of powdered uranium glasses

    NASA Technical Reports Server (NTRS)

    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.

  9. Stability and compatibility of antitumor agents in glass and plastic containers.

    PubMed

    Benvenuto, J A; Anderson, R W; Kerkof, K; Smith, R G; Loo, T L

    1981-12-01

    The stability of methotrexate, fluorouracil, cytarabine, dactinomycin, doxorubicin, bleomycin sulfate, mitomycin, mithramycin, vincristine sulfate, vinblastine sulfate, cyclophosphamide, dacarbazine, carmustine, and leucovorin calcium in underfilled plastic and glass administration containers was determined. Drugs were reconstituted according to manufacturers' instructions and added to 5% dextrose injection 50 ml in both polyvinyl chloride bags and glass partial-fill bottles. In addition, mitomycin was added to 0.9% sodium chloride injection 50 ml in both polyvinyl chloride bags and glass partial-fill bottles. All admixtures were stored at room temperature, not protected from light. Stability was determined over 24 hours (48 hours for doxorubicin and fluorouracil) by high-pressure liquid chromatography, except for cyclophosphamide (analyzed by mass spectrometry) and carmustine (analyzed by spectrophotometry). Methotrexate, leucovorin calcium, cytarabine, dactinomycin, mithramycin, vinblastine sulfate, cyclophosphamide, and dacarbazine were equally stable (10% or less change in concentration over 24 hours) in glass and plastic containers. Doxorubicin and fluorouracil were more stable in plastic containers than glass containers. The T90 value for doxorubicin in glass was 40 hours; there was no apparent decrease in plastic even after 48 hours. The T90 value for fluorouracil in glass was seven hours and in plastic, 43 hours. Vincristine sulfate, bleomycin sulfate, and carmustine were more stable in glass than plastic. The T90 value for vincristine sulfate in plastic was 10 hours. The T90 value for bleomycin sulfate in plastic was 0.7 hour. The T90 value for carmustine in plastic was 0.6 hour. Mitomycin dissolved in 0.9% sodium chloride injection was more stable in plastic. Mitomycin dissolved in 5% dextrose injection was not stable. Carmustine and bleomycin sulfate should be administered only in glass containers. Continuous infusions of doxorubicin and fluorouracil are

  10. Fabrication and characterization of poly-(ε)-caprolactone and bioactive glass composites for tissue engineering applications.

    PubMed

    Mohammadkhah, Ali; Marquardt, Laura M; Sakiyama-Elbert, Shelly E; Day, Delbert E; Harkins, Amy B

    2015-04-01

    Much work has focused on developing synthetic materials that have tailored degradation profiles and physical properties that may prove useful in developing biomaterials for tissue engineering applications. In the present study, three different composite sheets consisting of biodegradable poly-ε-caprolactone (PCL) and varying types of bioactive glass were investigated. The three composites were composed of 50wt.% PCL and (1) 50wt.% 13-93 B3 borate glass particles, (2) 50wt.% 45S5 silicate glass particles, or (3) a blend of 25wt.% 13-93 B3 and 25wt.% 45S5 glass particles. Degradation profiles determined for each composite showed the composite that contained only 13-93 B3 borate glass had a higher degradation rate compared to the composite containing only 45S5 silicate glass. Uniaxial tensile tests were performed on the composites to determine the effect of adding glass to the polymer on mechanical properties. The peak stress of all of the composites was lower than that of PCL alone, but 100% PCL had a higher stiffness when pre-reacted in cell media for 6weeks, whereas composite sheets did not. Finally, to determine whether the composite sheets would maintain neuronal growth, dorsal root ganglia isolated from embryonic chicks were cultured on composite sheets, and neurite outgrowth was measured. The bioactive glass particles added to the composites showed no negative effects on neurite extension, and neurite extension increased on PCL:45S5 PCL:13-93 B3 when pre-reacted in media for 24h. This work shows that composite sheets of PCL and bioactive glass particles provide a flexible biomaterial for neural tissue engineering applications.

  11. AD, the ALICE diffractive detector

    NASA Astrophysics Data System (ADS)

    Tello, Abraham Villatoro

    2017-03-01

    ALICE is one of the four large experiments at the CERN Large Hadron Collider (LHC). As a complement to its Heavy-Ion physics program, ALICE started during Run 1 of LHC an extensive program dedicated to the study of proton-proton diffractive processes. In order to optimize its trigger efficiencies and purities in selecting diffractive events, the ALICE Collaboration installed a very forward AD detector during the Long Shut Down 1 of LHC. This new forward detector system consists of two stations made of two layers of scintillator pads, one station on each side of the interaction point. With this upgrade, ALICE has substantially increased its forward physics coverage, including the double rapidity gap based selection of central production, as well as the measurements of inclusive diffractive cross sections.

  12. Comparison of Macedon and Darwin glass

    USGS Publications Warehouse

    Chapman, D.R.; Keil, Klaus; Annell, C.

    1967-01-01

    Chemical analyses are presented for major and minor elements in two specimens of natural glass reported from Macedon, Victoria, and are compared with new analyses of glass from Mt. Darwin, Tasmania. One specimen of Macedon glass is dark, the other light; both are spongy with relatively large cavities of size uncommon in Darwin glass. Some of the new analyses of Darwin glass extend considerably the compositional range previously reported for Mg, Ni and Co. The chemical composition of Macedon glass cannot be distinguished from that of Darwin glass for any of twenty-five elements investigated. It appears possible that the two specimens of glass reported from Macedon may represent either two mislabelled pieces of Darwin glass, or else a separate natural occurrence of Darwin glass 560 km north of Mt. Darwin. ?? 1967.

  13. Space processing of chalcogenide glass

    NASA Technical Reports Server (NTRS)

    Ali, M. A.; Larsen, D. C.

    1976-01-01

    The manner in which the weightless, containerless nature of in-space processing can be successfully utilized to improve the quality of infrared transmitting chalcogenide glasses was investigated. The following conclusions were reached: (1) Laboratory experiments have established the techniques, processes and equipment necessary for the production of high purity chalcogenide glasses. (2) Processing techniques have been successfully adopted for Ge28Sb12Se60 glass in a 1-g environment. (3) The Ge28Sb12Se60 glasses that have been processed have optical transmission around 63% (5 mm thick). (4) Laboratory experiments have established that the use of precursor materials in powdered form increases the oxygen contamination of the processed glass. This indicates that high purity precursor materials in bar or pellet form should be used. (5) Modifications were made on the MSFC acoustic levitator in an attempt to improve levitation stability during long-time experiments. Room temperature experiments on As2S3 glasses and high temperature experiments on polystyrene were conducted.

  14. BNFL Report Glass Formers Characterization

    SciTech Connect

    Schumacher, R.F.

    2000-07-27

    The objective of this task was to obtain powder property data on candidate glass former materials, sufficient to guide conceptual design and estimate the cost of glass former handling facilities as requested under Part B1 of BNFL Technical and Development Support. Twenty-nine glass forming materials were selected and obtained from vendors for the characterization of their physical properties, durability in caustic solution, and powder flow characteristics. A glass former was selected based on the characterization for each of the ten oxide classes required for Envelope A, B, and C mixtures. Three blends (A, B, and C) were prepared based on formulations provided by Vitreous State Laboratory and evaluated with the same methods employed for the glass formers. The properties obtained are presented in a series of attached Tables. It was determined that five of the ten glass formers, (kyanite, iron oxide, titania, zircon, and zinc oxide) have the potential to cause some level of solids f low problems. The problems might include arching or ratholing in the silo/hopper. In addition, all of the blends may require consideration for their handling.

  15. BNFL Report Glass Formers Characterization

    SciTech Connect

    Schumacher, R.F.

    2000-07-27

    The objective of this task was to obtain powder property data on candidate glass former materials, sufficient to guide conceptual design and estimate the cost of glass former handling facilities as requested under Part B1 of BNFL Technical and Development Support. Twenty-nine glass forming materials were selected and obtained from vendors for the characterization of their physical properties, durability in caustic solution, and powder flow characteristics. A glass former was selected based on the characterization for each of the ten oxide classes required for Envelope A, B, and C mixtures. Three blends (A, B, and C) were prepared based on formulations provided by Vitreous State Laboratory and evaluated with the same methods employed for the glass formers. The properties obtained are presented in a series of attached Tables. It was determined that five of the ten glass formers, (kyanite, iron oxide, titania, zircon, and zinc oxide) have the potential to cause some level of solids f low problems. In addition, all of the blends may require consideration for their handling. A number of engineering considerations and recommendations were prepared based on the experimental findings, experience, and other process considerations. Recommendations for future testing are included. In conjunction with future work, it is recommended that a professional consultant be engaged to guide and assist with testing and design input.

  16. Bioactive Glasses: Frontiers and Challenges.

    PubMed

    Hench, Larry L; Jones, Julian R

    2015-01-01

    Bioactive glasses were discovered in 1969 and provided for the first time an alternative to nearly inert implant materials. Bioglass formed a rapid, strong, and stable bond with host tissues. This article examines the frontiers of research crossed to achieve clinical use of bioactive glasses and glass-ceramics. In the 1980s, it was discovered that bioactive glasses could be used in particulate form to stimulate osteogenesis, which thereby led to the concept of regeneration of tissues. Later, it was discovered that the dissolution ions from the glasses behaved like growth factors, providing signals to the cells. This article summarizes the frontiers of knowledge crossed during four eras of development of bioactive glasses that have led from concept of bioactivity to widespread clinical and commercial use, with emphasis on the first composition, 45S5 Bioglass(®). The four eras are (a) discovery, (b) clinical application, (c) tissue regeneration, and (d) innovation. Questions still to be answered for the fourth era are included to stimulate innovation in the field and exploration of new frontiers that can be the basis for a general theory of bioactive stimulation of regeneration of tissues and application to numerous clinical needs.

  17. Monolithically integrated solid state laser and waveguide using spin-on glass

    DOEpatents

    Ashby, C.I.H.; Hohimer, J.P.; Neal, D.R.; Vawter, G.A.

    1995-10-31

    A monolithically integrated photonic circuit is disclosed combining a semiconductor source of excitation light with an optically active waveguide formed on the substrate. The optically active waveguide is preferably formed of a spin-on glass to which are added optically active materials which can enable lasing action, optical amplification, optical loss, or frequency conversion in the waveguide, depending upon the added material. 4 figs.

  18. Effect of glass phase on the dissolution of hydroxyapatite.

    PubMed

    Youn, S H; Yang, Z X; Hwang, K H; Seo, D S; Lee, J K; Jun, B S; Kim, H

    2008-02-01

    Nano size defect formation at grain boundary during the dissolution of hydroxyapatite in water was evaluated by adding several sintering additives for sinterability enhancement. In the case of sintered pure hydroxyapatite, significant dissolution occurred after immersion in distilled water or in simulated body fluid. The dissolution initiated at the grain boundaries creating nano-size defects like small pores that afterwards grew up to micro scale by increasing immersion time. This dissolution resulted in grain separation at the surfaces and finally in fracture. The dissolution concentrated on the grains adjacent to pores rather than those in the dense region. So hydroxyapatite ceramics containing glass powders were prepared to prevent the dissolution by strengthening grain boundary. Calcium silicate and phosphate glasses were added at 0 to 10 mass% and sintered at 1200 degrees C for 2 h in air with moisture protection. Glass phase was incorporated into hydroxyapatite to act as the sintering aid followed by crystallization in order to improve the mechanical properties without reducing biocompatibility. Dissolution tests, as well as X-ray diffraction and SEM showed little decomposition of hydroxyapatite to secondary phases and the fracture toughness increased compared to pure hydroxyapatite.

  19. Glass Membrane For Controlled Diffusion Of Gases

    DOEpatents

    Shelby, James E.; Kenyon, Brian E.

    2001-05-15

    A glass structure for controlled permeability of gases includes a glass vessel. The glass vessel has walls and a hollow center for receiving a gas. The glass vessel contains a metal oxide dopant formed with at least one metal selected from the group consisting of transition metals and rare earth metals for controlling diffusion of the gas through the walls of the glass vessel. The vessel releases the gas through its walls upon exposure to a radiation source.

  20. Downdraw Extrusion of ULE(TM) Glass.

    DTIC Science & Technology

    1984-12-01

    34 diameter orifice and a 7" inner diameter muffle plate. E. Glass Loading After removing the plastic and tissue paper from the cleaned feedstock glass , the...Final Technical Report December 1964 DOWNDRAW EXTRUSION OF ULETM GLASS0 Corning Glass Works P. M. Smith and C. E. Peters APPROVED FOR PUBLIC RELEASE...PERFORMING ORGANIZATION b. OFFICE SYMBOL 7a. NAME OF MONITORING ORGANIZATION (If Gpptieabte ) "Corning Glass Works Rome Air Development Center (OCSE

  1. "Limbo" through the Looking Glass: Adding the Voice of Family to the First Generation College Experience

    ERIC Educational Resources Information Center

    Daniel, Malinda Nichols

    2012-01-01

    In 2009 of the 9,793 undergraduates attending the University of Wyoming during the fall semester, 3,453 of them were first generation college students. The cultural assimilation often associated with college for first generation college students is often experienced by not only the student, but also the family left at home. This research serves as…

  2. Metastable metallic hydrogen glass

    SciTech Connect

    Nellis, W J

    2001-02-06

    The quest for metallic hydrogen has been going on for over one hundred years. Before hydrogen was first condensed into a liquid in 1898, it was commonly thought that condensed hydrogen would be a metal, like the monatomic alkali metals below hydrogen in the first column of the Periodic Table. Instead, condensed hydrogen turned out to be transparent, like the diatomic insulating halogens in the seventh column of the Periodic Table. Wigner and Huntington predicted in 1935 that solid hydrogen at 0 K would undergo a first-order phase transition from a diatomic to a monatomic crystallographically ordered solid at {approx}25 GPa. This first-order transition would be accompanied by an insulator-metal transition. Though searched for extensively, a first-order transition from an ordered diatomic insulator to a monatomic metal is yet to be observed at pressures up to 120 and 340 GPa using x-ray diffraction and visual inspection, respectively. On the other hand, hydrogen reaches the minimum electrical conductivity of a metal at 140 GPa, 0.6 g/cm{sup 3}, and 3000 K. These conditions were achieved using a shock wave reverberating between two stiff sapphire anvils. The shock wave was generated with a two-stage light-gas gun. This temperature exceeds the calculated melting temperature at 140 GPa by a factor of {approx}2, indicating that this metal is in the disordered fluid phase. The disorder permits hydrogen to become metallic via a Mott transition in the liquid at a much smaller pressure than in the solid, which has an electronic bandgap to the highest pressures reached to date. Thus, by using the finite temperature achieved with shock compression to achieve a disordered melt, metallic hydrogen can be achieved at a much lower pressure in a fluid than in a solid. It is not known how, nor even whether, metallic hydrogen can be quenched from a fluid at high pressures to a disordered solid metallic glass at ambient pressure and temperature. Because metallization occurs by simply

  3. Analysis of glass from the post-Roman settlement Tonovcov grad (Slovenia) by PIXE-PIGE and LA-ICP-MS

    NASA Astrophysics Data System (ADS)

    Šmit, Ž.; Milavec, T.; Fajfar, H.; Rehren, Th.; Lankton, J. W.; Gratuze, B.

    2013-09-01

    The combined PIXE-PIGE method was used for the analysis of 43 glass fragments from the archaeological site Tonovcov grad in western Slovenia, with 10 of these additionally being analysed by LA-ICP-MS. The glass objects were attributed to the Late Antique production of the 4th-7th c. AD, with two examples of early Roman glass and three glass beads, one of them presumably of oriental origin. The analysis showed typical natron-type glass, produced in the Levantine region around the river Belus, and a few examples of HIMT glass, which could be recognized also in several other recycled objects. Only one glass bead, found in Early Medieval context, was made of the ash of halophytic plants.

  4. HIGH-LEVEL WASTE GLASS FORMULATION MODEL SENSITIVITY STUDY 2009 GLASS FORMULATION MODEL VERSUS 1996 GLASS FORMULATION MODEL

    SciTech Connect

    BELSHER JD; MEINERT FL

    2009-12-07

    This document presents the differences between two HLW glass formulation models (GFM): The 1996 GFM and 2009 GFM. A glass formulation model is a collection of glass property correlations and associated limits, as well as model validity and solubility constraints; it uses the pretreated HLW feed composition to predict the amount and composition of glass forming additives necessary to produce acceptable HLW glass. The 2009 GFM presented in this report was constructed as a nonlinear optimization calculation based on updated glass property data and solubility limits described in PNNL-18501 (2009). Key mission drivers such as the total mass of HLW glass and waste oxide loading are compared between the two glass formulation models. In addition, a sensitivity study was performed within the 2009 GFM to determine the effect of relaxing various constraints on the predicted mass of the HLW glass.

  5. Glass matrix composites from coal flyash and waste glass

    SciTech Connect

    Boccaccini, A.R.; Buecker, M.; Bossert, J.; Marszalek, K.

    1997-12-31

    Glass matrix composites have been fabricated from waste materials by means of powder technology. Flyash from coal power stations and waste glass, residue of float glass production, were used. Commercial alumina platelets were employed as the reinforcing component. For flyash contents up to 20% by weight nearly fully dense compacts could be fabricated by using relatively low sintering temperatures (650 C). For higher flyash contents the densification was hindered due to the presence of crystalline particles in the as-received flyash, which jeopardized the viscous flow densification mechanism. The addition of alumina platelets resulted in better mechanical properties of the composites than those of the unreinforced matrix, despite a residual porosity present. Young`s modulus, modulus of rupture, hardness and fracture toughness increase with platelet volume fraction. The low brittleness index of the composites suggests that the materials have good machinability. A qualitative analysis of the wear behavior showed that the composite containing 20% by volume platelet addition has a higher wear resistance than the unreinforced matrix. Overall, the results indicate that the materials may compete with conventional glasses and glass-ceramics in technical applications.

  6. Sol-gel synthesis and in vitro bioactivity of copper and zinc-doped silicate bioactive glasses and glass-ceramics.

    PubMed

    Bejarano, Julian; Caviedes, Pablo; Palza, Humberto

    2015-03-11

    Metal doping of bioactive glasses based on ternary 60SiO2-36CaO-4P2O5 (58S) and quaternary 60SiO2-25CaO-11Na2O-4P2O5 (NaBG) mol% compositions synthesized using a sol-gel process was analyzed. In particular, the effect of incorporating 1, 5 and 10 mol% of CuO and ZnO (replacing equivalent quantities of CaO) on the texture, in vitro bioactivity, and cytocompatibility of these materials was evaluated. Our results showed that the addition of metal ions can modulate the textural property of the matrix and its crystal structure. Regarding the bioactivity, after soaking in simulated body fluid (SBF) undoped 58S and NaBG glasses developed an apatite surface layer that was reduced in the doped glasses depending on the type of metal and its concentration with Zn displaying the largest inhibitions. Both the ion release from samples and the ion adsorption from the medium depended on the type of matrix with 58S glasses showing the highest values. Pure NaBG glass was more cytocompatible to osteoblast-like cells (SaOS-2) than pure 58S glass as tested by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. The incorporation of metal ions decreased the cytocompatibility of the glasses depending on their concentration and on the glass matrix doped. Our results show that by changing the glass composition and by adding Cu or Zn, bioactive materials with different textures, bioactivity and cytocompatibility can be synthesized.

  7. The New York Times ad.

    PubMed

    Hunt, M E; Kissling, F

    1993-01-01

    Feminization of patriarchal institutions is necessary in order to eliminate the exclusivity and mutuality of hierarchical, gender, class, and race stratification. The aim of this paper is to explain the history and activities surrounding the New York Times ad on Sunday, October 7, 1984 (the Catholic Statement on Pluralism and Abortion signed by Barbara Ferraro and Patricia Hussey of the Sisters of Note Dame de Namur, Rose Dominic Trapasso of the Maryknoll Sisters, and 67 other signers). The significance of this ad for Roman Catholic feminists and suggestions for new models of relationships between feminists is given. The Statement was written by Daniel Maguire and Frances Kissling and reviewed by 20 Roman Catholic ethicists. A sponsoring committee of early signers sought other support. Catholics for a Free Choice sponsored the funding for circulation of the Statement among professional societies, but not necessarily canonical communities. Publication of the entire statement in the Times was at the height of the presidential campaign. Conservative Bishops Bernard Law of Boston and John O'Connor of Boston publicly denounced Ferraro's position. The first institutional church response came on November 14, 1984, and stated that the Statement was personal opinion and contradictory to clear and constant church teachings about abortion. On November 30, 1984, Cardinal Jean Jerome Hamer of the Congregation for Religious and Secular Institutes responded to most presidents of canonical communities to request a public retraction from signers under threat of dismissal. The issue was obedience to the church. Several members of the canonical community and priests published retractions; negotiations with the Vatican began. Freedom of conscience and empowerment of canonical communities, as agents of their own lives, were given as reasons for the challenge to paternalism. The response was that women were subject to obedience within their communities and had taken public vows and were

  8. Natural analogues of nuclear waste glass corrosion.

    SciTech Connect

    Abrajano, T.A. Jr.; Ebert, W.L.; Luo, J.S.

    1999-01-06

    This report reviews and summarizes studies performed to characterize the products and processes involved in the corrosion of natural glasses. Studies are also reviewed and evaluated on how well the corrosion of natural glasses in natural environments serves as an analogue for the corrosion of high-level radioactive waste glasses in an engineered geologic disposal system. A wide range of natural and experimental corrosion studies has been performed on three major groups of natural glasses: tektite, obsidian, and basalt. Studies of the corrosion of natural glass attempt to characterize both the nature of alteration products and the reaction kinetics. Information available on natural glass was then compared to corresponding information on the corrosion of nuclear waste glasses, specifically to resolve two key questions: (1) whether one or more natural glasses behave similarly to nuclear waste glasses in laboratory tests, and (2) how these similarities can be used to support projections of the long-term corrosion of nuclear waste glasses. The corrosion behavior of basaltic glasses was most similar to that of nuclear waste glasses, but the corrosion of tektite and obsidian glasses involves certain processes that also occur during the corrosion of nuclear waste glasses. The reactions and processes that control basalt glass dissolution are similar to those that are important in nuclear waste glass dissolution. The key reaction of the overall corrosion mechanism is network hydrolysis, which eventually breaks down the glass network structure that remains after the initial ion-exchange and diffusion processes. This review also highlights some unresolved issues related to the application of an analogue approach to predicting long-term behavior of nuclear waste glass corrosion, such as discrepancies between experimental and field-based estimates of kinetic parameters for basaltic glasses.

  9. Characteristic length of glass transition

    NASA Astrophysics Data System (ADS)

    Donth, E.

    1996-03-01

    The characteristic length of the glass transition (ξ _α ) is based on the concept of cooperatively rearranging regions (CRR's) by Adam & Gibbs (1965): ξ _α is the diameter of one CRR. In the theoretical part of the talk a formula is derived how this length can be calculated from calorimetric data of the transformation interval. The approach is based on fluctuations in natural functional subsystems. The corresponding thermodynamics is represented e.g. in a book of the author (E. Donth, Relaxation and Thermodynamics in Polymers. Glass Transition, Akademie-Verlag, Berlin 1992). A typical value for this length is 3 nanometers. In the experimental part several examples are reported to enlarge the experimental evidence for such a length: Squeezing the glass transition in the amorphous layers of partially crystallized PET (C. Schick, Rostock), glass transition of small-molecule glass formers in a series of nanoscaled pores of porous glasses (F. Kremer, Leipzig), comparison with a concentration fluctuation model in homogeneous polymer mixtures (E.W. Fischer, Mainz), and, from our laboratory, backscaling to ξ _α across the main transition from the entanglement spacing in several amorphous polymers such as PVAC, PS, NR, and some polymer networks. Rouse backscaling was possible in the α β splitting region of several poly(n alkyl methacrylates) resulting in small characteristic lengths of order 1 nanometer near the onset of α cooperativity. In a speculative outlook a dynamic density pattern is presented, having a cellular structure with higher density and lower mobility of the cell walls. It will be explained, with the aid of different thermal expansion of wall and clusters, how the clusters within the cells maintain a certain mobility far below the glass temperature.

  10. Intracellular Signaling and Desmoglein 2 Shedding Triggered by Human Adenoviruses Ad3, Ad14, and Ad14P1

    PubMed Central

    Wang, Hongjie; Ducournau, Corinne; Saydaminova, Kamola; Richter, Maximilian; Yumul, Roma; Ho, Martin; Carter, Darrick; Zubieta, Chloé

    2015-01-01

    ABSTRACT We recently discovered that desmoglein 2 (DSG2) is a receptor for human adenovirus species B serotypes Ad3, Ad7, Ad11, and Ad14. Ad3 is considered to be a widely distributed human pathogen. Ad3 binding to DSG2 triggers the transient opening of epithelial junctions. Here, we further delineate the mechanism that leads to DSG2-mediated epithelial junction opening in cells exposed to Ad3 and recombinant Ad3 fiber proteins. We identified an Ad3 fiber knob-dependent pathway that involves the phosphorylation of mitogen-activated protein (MAP) kinases triggering the activation of the matrix-metalloproteinase ADAM17. ADAM17, in turn, cleaves the extracellular domain of DSG2 that links epithelial cells together. The shed DSG2 domain can be detected in cell culture supernatant and also in serum of mice with established human xenograft tumors. We then extended our studies to Ad14 and Ad14P1. Ad14 is an important research and clinical object because of the recent appearance of a new, more pathogenic strain (Ad14P1). In a human epithelial cancer xenograft model, Ad14P1 showed more efficient viral spread and oncolysis than Ad14. Here, we tested the hypothesis that a mutation in the Ad14P1 fiber knob could account for the differences between the two strains. While our X-ray crystallography studies suggested an altered three-dimensional (3D) structure of the Ad14P1 fiber knob in the F-G loop region, this did not significantly change the fiber knob affinity to DSG2 or the intracellular signaling and DSG2 shedding in epithelial cancer cells. IMPORTANCE A number of widely distributed adenoviruses use the epithelial junction protein DSG2 as a receptor for infection and lateral spread. Interaction with DSG2 allows the virus not only to enter cells but also to open epithelial junctions which form a physical barrier to virus spread. Our study elucidates the mechanism beyond virus-triggered junction opening with a focus on adenovirus serotype 3. Ad3 binds to DSG2 with its fiber

  11. Condom ads promote illicit sex.

    PubMed

    Kippley, J F

    1994-01-01

    Written in 1987, this opinion was republished in the wake of US President Bill Clinton's AIDS prevention media campaign promoting condom use which began January 1994, targeted at young adults aged 18-25. The author staunchly opposes condom use even though he admits that people do not consider abstinence from sex to be a serious option for the prevention of HIV/STD infection. He believes that there is no moral use of sex with a condom and that condoms have always been a sign of immorality, be it prostitution, adultery, fornication, or marital contraception. Likewise, the author laments the success enjoyed by Planned Parenthood in achieving the social acceptance of marital contraception and sex outside of marriage. The complete social acceptance of homosexual activity, however, remains to be achieved. Magazines, newspapers, and television receive income in exchange for publishing or airing advertisements. Finding offensive advertisements which promote the use of condoms against HIV infection, the author recommends writing letters of complaint to the responsible media sources. If the television stations or publications in question continue to advertise condoms to the public, stop watching them or end one's subscriptions to the particular printed media. Such action taken collectively among many individuals will reduce product sales and income, and potentially sway corporate policy against condom ads.

  12. 16 CFR 460.18 - Insulation ads.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... INSULATION § 460.18 Insulation ads. (a) If your ad gives an R-value, you must give the type of insulation and... your ad gives a price, you must give the type of insulation, the R-value at a specific thickness, the... you give the price per square foot, you do not have to give the coverage area. (c) If your ad...

  13. 16 CFR 460.18 - Insulation ads.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... INSULATION § 460.18 Insulation ads. (a) If your ad gives an R-value, you must give the type of insulation and... your ad gives a price, you must give the type of insulation, the R-value at a specific thickness, the... you give the price per square foot, you do not have to give the coverage area. (c) If your ad...

  14. Myths & Facts about Value-Added Analysis

    ERIC Educational Resources Information Center

    TNTP, 2011

    2011-01-01

    This paper presents myths as well as facts about value-added analysis. These myths include: (1) "Value-added isn't fair to teachers who work in high-need schools, where students tend to lag far behind academically"; (2) "Value-added scores are too volatile from year-to-year to be trusted"; (3) "There's no research behind value-added"; (4) "Using…

  15. SUMMARY OF 2010 DOE EM INTERNATIONAL PROGRAM STUDIES OF WASTE GLASS MELT RATE ENHANCEMENT

    SciTech Connect

    Fox, K.; Marra, J.

    2011-01-19

    A collaborative study has been established under the U.S. Department of Energy (DOE) Office of Environmental Management International Program between the Savannah River National Laboratory (SRNL) and the V. G. Khlopin Radium Institute (KRI) in St. Petersburg, Russia, to investigate potential improvements in melt rate via chemical additions to the glass frit. Researchers at KRI suggested a methodology for selecting frit additives based on empirical coefficients for optimization of glass melting available in the Russian literature. Using these coefficients, KRI identified B{sub 2}O{sub 3}, CuO, and MnO as frit additives that were likely to improve melt rate without having adverse effects on crystallization of the glass or its chemical durability. The results of the melt rate testing in the SMK melter showed that the slurry feed rate (used as a gauge of melt rate) could be significantly increased when MnO or CuO were added to Frit 550 with the SMR-2 sludge. The feed rates increased by about 27% when MnO was added to the frit and by about 26% when CuO was added to the frit, as compared to earlier results for Frit 550 alone. The impact of adding additional B{sub 2}O{sub 3} to the frit was minor when added with CuO. The additional B{sub 2}O{sub 3} showed a more significant, 39% improvement in melt rate when added with MnO. The additional B{sub 2}O{sub 3} also reduced the viscosity of the glasses during pouring. Samples of the glasses from the melt rate testing characterized at SRNL showed that there were no significant impacts on crystallization of the glasses. All of the glasses had very good chemical durability. Chemical composition measurements showed that the frit additives were present in concentrations below the targeted values in some of the glasses. Therefore, it is possible that higher concentrations of these additives may further improve melt rate, although the impacts of higher concentrations of these components on crystallization and durability would need to

  16. Compositional dependence of in vitro response to commercial silicate glasses

    NASA Astrophysics Data System (ADS)

    Jedlicka, Amy B.

    Materials are often incorporated into the human body, interacting with surrounding fluids, cells and tissues. The reactions that occur between a material and this surrounding biological system are not fundamentally understood. Basic knowledge of material biocompatibility and the controlling processes is lacking. This thesis examines material biocompatibility of a series of silicate-based glasses on a primary level determining cell response to material composition and durability. The silicate glass system studied included two BioglassRTM compositions with known biologically favorable response, two fiberglass compositions, with demonstrated 'not-unfavorable' in vitro response, a ternary soda-lime-silicate glass, a binary alkali silicate glass, and pure silica. Chemical durability was analyzed in three different fluids through solution analysis and material characterization. In vitro response to the substrates was observed. Cell behavior was then directly correlated to the material behavior in cell culture medium under the same conditions as the in vitro test, yet in the absence of cells. The effect of several physical and chemical surface treatments on substrates with predetermined biocompatible behavior was subsequently determined. The chemically durable glasses with no added B2O3 elicited similar cell response as the control polystyrene substrate. The addition of B2O3 resulted in polygonal cell shape and restricted cell proliferation. The non-durable glasses presented a dynamic surface to the cells, which did not adversely affect in vitro response. Extreme dissolution of the binary alkali silicate glass in conjunction with increased pH resulted in unfavorable cell response. Reaction of the Bioglass RTM compositions, producing a biologically favorable calcium-phosphate surface film, caused enhanced cell attachment and spreading. Surface energy increase due to sterilization procedures did not alter cellular response. Surface treatment procedures influencing substrate

  17. Glass reinforced hydroxyapatite for hard tissue surgery--part 1: Mechanical properties.

    PubMed

    Georgiou, G; Knowles, J C

    2001-10-01

    Commercial hydroxyapatite (HA) was reinforced by adding 2.5 and 5 wt% of a Na2O-CaO-P2O5 glass and then sintered. The resulting composites have chemical compositions that are similar to the inorganic constituent of the mineral part of bone, and are closely related to the trace elements that are present, in this case Na. X-ray diffraction showed no decomposition of HA to secondary phases; however, the glass reinforced-HA composites contained a HA phase and variable amounts of tricalcium phosphate phase, depending on the sintering temperature and the amount of glass added. The HA-composite material exhibited higher flexural strength overall compared to sintered HA. The presence of secondary phases beta- and alpha-tricalcium phosphate in the microstructure of the composites has a major influence on the mechanical properties. Additionally, the presence of porosity also has a bearing on the mechanical properties of the material.

  18. The effect of HWVP feed nitrate and carbonate content on glass redox adjustment

    SciTech Connect

    Wiemers, K.D.

    1996-03-01

    The Hanford Waste Vitrification Plant (HWVP) is being designed for the Department of Energy to immobilize pretreated radioactive high-level waste (HLW) as glass for geological disposal. In the HWVP formic acid will be added to the pretreated HLW prior to vitrification. The formic acid is added to adjust the feed rheology and to provide a reductant which maintains the feed in the melter within an acceptable redox range. This study was conducted to evaluate the effect of nitrate and carbonate concentrations in the pretreated neutralized current acid waste (NCAW) feed on the amount of formic acid required to obtain an acceptable glass redox state in the melter. The glass redox state was measured by the Fe{sup +2}/Fe{sup +3} ratio in the vitrified product.

  19. Mechanical properties of bioactive glasses, glass-ceramics and composites.

    PubMed

    Thompson, I D; Hench, L L

    1998-01-01

    The application of bioactive glass and glass-ceramics has been widely documented over the past twenty years but the high modulus and low fracture toughness has made them less applicable for clinical, load bearing, applications. The development of non-resorbable polyethylene and polysulphone matrices for these materials has improved the mechanical properties. However, the primary concern of whether the bioactivity of the composites is reduced is still unresolved. The more recent development of resorbable carrier systems, dextran and collagen, for bioactive glasses does not introduce such problems, hence making this form of composite suitable for novel soft tissue applications. The development of a simple quality index has enabled some of the materials described within this paper to be ranked by their ability to replace bone, thus enabling possible new research directions to be emphasized.

  20. Multiple reentrant glass transitions in confined hard-sphere glasses

    NASA Astrophysics Data System (ADS)

    Mandal, Suvendu; Lang, Simon; Gross, Markus; Oettel, Martin; Raabe, Dierk; Franosch, Thomas; Varnik, Fathollah

    2014-07-01

    Glass-forming liquids exhibit a rich phenomenology upon confinement. This is often related to the effects arising from wall-fluid interactions. Here we focus on the interesting limit where the separation of the confining walls becomes of the order of a few particle diameters. For a moderately polydisperse, densely packed hard-sphere fluid confined between two smooth hard walls, we show via event-driven molecular dynamics simulations the emergence of a multiple reentrant glass transition scenario upon a variation of the wall separation. Using thermodynamic relations, this reentrant phenomenon is shown to persist also under constant chemical potential. This allows straightforward experimental investigation and opens the way to a variety of applications in micro- and nanotechnology, where channel dimensions are comparable to the size of the contained particles. The results are in line with theoretical predictions obtained by a combination of density functional theory and the mode-coupling theory of the glass transition.

  1. Mechanical properties of non-woven glass fiber geopolymer composites

    NASA Astrophysics Data System (ADS)

    Rieger, D.; Kadlec, J.; Pola, M.; Kovářík, T.; Franče, P.

    2017-02-01

    This experimental research focuses on mechanical properties of non-woven glass fabric composites bound by geopolymeric matrix. This study investigates the effect of different matrix composition and amount of granular filler on the mechanical properties of final composites. Matrix was selected as a metakaolin based geopolymer hardened by different amount of potassium silicate activator. The ceramic granular filler was added into the matrix for investigation of its impact on mechanical properties and workability. Prepared pastes were incorporated into the non-woven fabrics by hand roller and final composites were stacked layer by layer to final thickness. The early age hardening of prepared pastes were monitored by small amplitude dynamic rheology approach and after 28 days of hardening the mechanical properties were examined. The electron microscopy was used for detail description of microstructural properties. The imaging methods revealed good wettability of glass fibers by geopolymeric matrix and results of mechanical properties indicate usability of these materials for constructional applications.

  2. Tetraethyl orthosilicate-based glass composition and method

    DOEpatents

    Wicks, G.G.; Livingston, R.R.; Baylor, L.C.; Whitaker, M.J.; O`Rourke, P.E.

    1997-06-10

    A tetraethyl orthosilicate-based, sol-gel glass composition with additives selected for various applications is described. The composition is made by mixing ethanol, water, and tetraethyl orthosilicate, adjusting the pH into the acid range, and aging the mixture at room temperature. The additives, such as an optical indicator, filler, or catalyst, are then added to the mixture to form the composition which can be applied to a substrate before curing. If the additive is an indicator, the light-absorbing characteristics of which vary upon contact with a particular analyte, the indicator can be applied to a lens, optical fiber, reagent strip, or flow cell for use in chemical analysis. Alternatively, an additive such as alumina particles is blended into the mixture to form a filler composition for patching cracks in metal, glass, or ceramic piping. 12 figs.

  3. Tetraethyl orthosilicate-based glass composition and method

    DOEpatents

    Wicks, George G.; Livingston, Ronald R.; Baylor, Lewis C.; Whitaker, Michael J.; O'Rourke, Patrick E.

    1997-01-01

    A tetraethyl orthosilicate-based, sol-gel glass composition with additives selected for various applications. The composition is made by mixing ethanol, water, and tetraethyl orthosilicate, adjusting the pH into the acid range, and aging the mixture at room temperature. The additives, such as an optical indicator, filler, or catalyst, are then added to the mixture to form the composition which can be applied to a substrate before curing. If the additive is an indicator, the light-absorbing characteristics of which vary upon contact with a particular analyte, the indicator can be applied to a lens, optical fiber, reagant strip, or flow cell for use in chemical analysis. Alternatively, an additive such as alumina particles is blended into the mixture to form a filler composition for patching cracks in metal, glass, or ceramic piping.

  4. New Features in the ADS Abstract Service

    NASA Technical Reports Server (NTRS)

    Eichhorn, Guenther; Accomazzi, Alberto; Grant, Carolyn S.; Kurtz, Michael J.; Henneken, Edwin A.; Thompson, Donna M.; Murray, Stephen S.

    2005-01-01

    The NASA-ADS Abstract Service provides a sophisticated search capability for the literature in Astronomy, Planetary Sciences, Physics/Geophysics, and Space Instrumentation. The ADS is funded by NASA and access to the ADS services is free to anybody world-wide without restrictions. It allows the user to search the literature by author, title, and abstract text.

  5. 27 CFR 19.456 - Adding denaturants.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Adding denaturants. 19.456... Denaturation § 19.456 Adding denaturants. Denaturants and spirits shall be mixed in packages, tanks, or bulk... proprietor shall submit a flow diagram of the intended process or method of adding denaturants. (Sec....

  6. Weighing the Claims in Diet Ads

    MedlinePlus

    ... página en español Weighing the Claims in Diet Ads Related Items Weight Loss Challenge Diet Ads and ... control Information Network .  The Truth Behind Weight Loss Ads Claims to watch out for include: Lose weight ...

  7. Crystallization of Yttrium and Samarium Aluminosilicate Glasses

    NASA Astrophysics Data System (ADS)

    Lago, Diana C.; Prado, Miguel O.

    Aluminosilicate glasses containing samarium and yttrium (SmAS and YAS glasses) exhibit high glass transition temperatures, corrosion resistance, and glass stability on heating which make them useful for technological applications. Yttrium aluminosilicate glass microspheres are currently being used for internal selective radiotherapy of liver cancer. During the preparation process, crystallization needs to be totally or partially avoided depending on the final application. Thus knowing the crystallization kinetics can help to prevent or avoid it, by designing a proper thermal pathway. In this work we studied the crystallization kinetics of YAS and SmAS glasses. It was found that both, YAS and SmAS glasses crystallize from the surface. SmAS glass presented lower densities of nucleation sites. The results also showed that the crystal growth apparent enthalpy is larger for SmAS glasses.

  8. Mechanisms of Rhyolitic Glass Hydration Below the Glass Transition

    SciTech Connect

    Anovitz, Lawrence {Larry} M; Cole, David R; Fayek, Mostafa

    2008-01-01

    Although a great deal is known about the interaction between water and rhyolitic glasses and melts at temperatures above the glass transition, the nature of this interaction at lower temperatures is much more obscure. Comparisons between high- and low-temperature diffusion studies suggest that several factors play important roles under lower-temperature conditions that are not significant at higher temperatures. Water concentrations in rhyolitic glasses hydrated at low temperatures are significantly greater than in those hydrated at high temperatures and low pressures. Surface concentrations, which equilibrate quickly with the surrounding environment at high temperature, change far more slowly as temperature decreases, and may not equilibrate at room temperature for hundreds or thousands of years. Temperature extrapolations of high- and low-temperature diffusion data are not consistent, suggesting that a change in mechanism occurs. These differences may be due to the inability of "self-stress," caused by the in-diffusing species, to relax at lower temperature. Preliminary calculations suggest that the level of stress caused by glass-water interaction may be greater than the tensile strength of the glass. On a microstuctural scale, extrapolations of high-temperature Fourier transform infrared spectroscopy (FTIR) data to lower temperatures suggests that there should be little or no hydroxyl present in glasses hydrated at low temperature. Comparisons of low-temperature hydration results among SiO2, obsidian, and albite compositions show distinct differences, and features are present in the spectra that do not occur at high temperature. Analysis of H2O and D2O diffusion also suggest that mechanistic differences occur between low- and high-temperature diffusive processes.

  9. Bioactive Glasses: Frontiers and Challenges

    PubMed Central

    Hench, Larry L.; Jones, Julian R.

    2015-01-01

    Bioactive glasses were discovered in 1969 and provided for the first time an alternative to nearly inert implant materials. Bioglass formed a rapid, strong, and stable bond with host tissues. This article examines the frontiers of research crossed to achieve clinical use of bioactive glasses and glass–ceramics. In the 1980s, it was discovered that bioactive glasses could be used in particulate form to stimulate osteogenesis, which thereby led to the concept of regeneration of tissues. Later, it was discovered that the dissolution ions from the glasses behaved like growth factors, providing signals to the cells. This article summarizes the frontiers of knowledge crossed during four eras of development of bioactive glasses that have led from concept of bioactivity to widespread clinical and commercial use, with emphasis on the first composition, 45S5 Bioglass®. The four eras are (a) discovery, (b) clinical application, (c) tissue regeneration, and (d) innovation. Questions still to be answered for the fourth era are included to stimulate innovation in the field and exploration of new frontiers that can be the basis for a general theory of bioactive stimulation of regeneration of tissues and application to numerous clinical needs. PMID:26649290

  10. Antibacterial effects of glass ionomers.

    PubMed

    DeSchepper, E J; White, R R; von der Lehr, W

    1989-04-01

    Glass ionomer cements have been shown to possess antimicrobial activity. Proposed mechanisms of action include acidity and fluoride. It was the purpose of this study to determine the antimicrobial effect of 11 glass ionomer cements, their individual powder and liquid components and one resin-bonded liner containing high fluoride ionomer glass against Streptococcus mutans #6715. The role of fluoride and pH in the antibacterial activity was also studied. Using agar diffusion assay methodology, the following results were obtained. All of the glass ionomer cements were inhibitory against S. mutans. The antibacterial cements and slurries that were tested for fluoride, released the ion in excess of reported minimum inhibitory values. The antimicrobial activity of the liquid components, that were tested for the effects of pH changes, was totally lost when the pH was adjusted to 5. The resin bonded liner was inactive against S. mutans and did not release inhibitory concentrations of fluoride. These results indicate that freshly-mixed glass ionomer cements are antimicrobial against S. mutans and that the mechanism of action is probably a function of both fluoride and pH although additional factors may be involved.

  11. Photosensitivity phenomena in multicomponent glasses

    NASA Astrophysics Data System (ADS)

    Czachor, K.; Jedrzejewski, K.; Stępień, R.

    2005-09-01

    Low cost, high bandwidth, narrowband and multifunctionality are main targets for new optical devices development. Planar optics is probably the best solution for future telecom long distance and access transmission networks but also for metrology sensing devices. Many different materials can be used for this purpose like PECVD silica, multicomponent glasses or even polymers. Bragg grating inscription in such material is another advantage to achieve narrowband spectral characteristic of device, which is essential in modern systems. The main purpose of presented work was the development in technology and measurement techniques of channels formed on the surface of the glass. Planar couplers and structures that are more complicated can also be made in the same technology in the future. Special multicomponent glasses SiO2-GeO2-B2O3-Na2O-SnO2 with up to 6 %mol of Sn were synthetized and thin rectangular polished plates were prepared. The UV 244 nm 100 mW Coherent argon ion frequency doubled laser was used in our experiments. Surface relief structures similar to the compaction-densification/expansion model of photosensitivity were developed on the glass surface. The optical microscope and alpha-step profiler were used for preliminary tests of photoinduced structures on the glass surface. The ability of the writing possibility in function of Sn content and different laser power levels were analyzed.

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

    PubMed

    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

    2013-08-09

    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.

  13. Efficient cluster Monte Carlo algorithm for Ising spin glasses in more than two space dimensions

    NASA Astrophysics Data System (ADS)

    Ochoa, Andrew J.; Zhu, Zheng; Katzgraber, Helmut G.

    2015-03-01

    A cluster algorithm that speeds up slow dynamics in simulations of nonplanar Ising spin glasses away from criticality is urgently needed. In theory, the cluster algorithm proposed by Houdayer poses no advantage over local moves in systems with a percolation threshold below 50%, such as cubic lattices. However, we show that the frustration present in Ising spin glasses prevents the growth of system-spanning clusters at temperatures roughly below the characteristic energy scale J of the problem. Adding Houdayer cluster moves to simulations of Ising spin glasses for T ~ J produces a speedup that grows with the system size over conventional local moves. We show results for the nonplanar quasi-two-dimensional Chimera graph of the D-Wave Two quantum annealer, as well as conventional three-dimensional Ising spin glasses, where in both cases the addition of cluster moves speeds up thermalization visibly in the physically-interesting low temperature regime.

  14. Structural relaxation and aging scaling in the Coulomb and Bose glass models

    NASA Astrophysics Data System (ADS)

    Assi, Hiba; Chaturvedi, Harshwardhan; Pleimling, Michel; Täuber, Uwe Claus

    2016-11-01

    We employ Monte Carlo simulations to study the relaxation properties of the two-dimensional Coulomb glass in disordered semiconductors and the three-dimensional Bose glass in type-II superconductors in the presence of extended linear defects. We investigate the effects of adding non-zero random on-site energies from different distributions on the properties of the correlation-induced Coulomb gap in the density of states (DOS) and on the non-equilibrium aging kinetics highlighted by the density autocorrelation functions. We also probe the sensitivity of the system's equilibrium and non-equilibrium relaxation properties to instantaneous changes in the density of charge carriers in the Coulomb glass or flux lines in the Bose glass.

  15. Getting the focus right: New Zealand baby boomers and advertisements for glasses.

    PubMed

    FitzPatrick, Mary; King, Chloe; Davey, Janet

    2013-01-01

    Although baby boomers constitute an attractive market segment in terms of spending power and size, they have been largely ignored and/or misunderstood by advertisers. This article presents the results of qualitative research into New Zealand baby boomers' responses to advertisements for glasses as a specific health-related product. Key themes emphasize an advertisement's "relate-ability"; the use of "real" characters; the importance of narrative in engaging the viewer; and the standout design elements of information intensity, humor, and point of difference. Themes are related to advertisements for glasses and illustrated in a mock-up "ideal ad" for glasses. Finally, practical recommendations are made for more effective advertising of glasses to baby boomers.

  16. Analysis of Roman glass from Albania by PIXE-PIGE method

    NASA Astrophysics Data System (ADS)

    Šmit, Ž.; Tartari, F.; Stamati, F.; Vevecka Priftaj, A.; Istenič, J.

    2013-02-01

    A series of 31 Roman glasses dated to the 1st-4th c. AD from the present Albania was analyzed by the combined PIXE-PIGE method. The analysis shows typical natron-based glass of the Roman period, though statistical treatment using principal component analysis and bivariate plots reveals four distinct groups, which are qualified by increased levels of potassium, magnesium and titanium-manganese-iron oxides, respectively. MgO content may exceed 2% and reach the level commonly accepted for halophytic plant-ash glass. The groups are formed on account of mineral impurities in the sand, which gives support to the thesis of multiple production centers of raw glass in the imperial age.

  17. Healing of lithographically introduced cracks in glass and glass-containing ceramics

    SciTech Connect

    Ackler, H.D.

    1998-12-01

    The morphological evolution of lithographically defined cracklike flaws in glass and glass-containing ceramics was studied at elevated temperatures. The systems studied have glass contents from 100 to approximately 0.5 vol%, providing insight to the contribution of viscous flow of the glass to crack healing over a range of glass contents spanning many industrial ceramics. Healing behavior is found to be controlled by viscous flow of glass in all cases except the lowest glass content, for which significant mass transport is only accomplished by diffusional mechanisms. This implies a change of mechanism below some critical glass content.

  18. HLW Glass Studies: Development of Crystal-Tolerant HLW Glasses

    SciTech Connect

    Matyas, Josef; Huckleberry, Adam R.; Rodriguez, Carmen P.; Lang, Jesse B.; Owen, Antionette T.; Kruger, Albert A.

    2012-04-02

    In our study, a series of lab-scale crucible tests were performed on designed glasses of different compositions to further investigate and simulate the effect of Cr, Ni, Fe, Al, Li, and RuO2 on the accumulation rate of spinel crystals in the glass discharge riser of the HLW melter. The experimental data were used to expand the compositional region covered by an empirical model developed previously (Matyáš et al. 2010b), improving its predictive performance. We also investigated the mechanism for agglomeration of particles and impact of agglomerates on accumulation rate. In addition, the TL was measured as a function of temperature and composition.

  19. Glass matrix composites. I - Graphite fiber reinforced glass

    NASA Technical Reports Server (NTRS)

    Prewo, K. M.; Bacon, J. F.

    1978-01-01

    An experimental program is described in which graphite fibers of Hercules HMS and HTS, Thornel 300, and Celanese DG-12 were used to reinforce, both uniaxially and biaxially, borosilicate pyrex glass. Composite flexural strength distribution, strength as a function of test temperature, fracture toughness and oxidative stability were determined and shown to be primarily a function of fiber type and the quality of fiber-matrix bond formed during composite fabrication. It is demonstrated that the graphite fiber reinforced glass system offers unique possibilities as a high performance structural material.

  20. Historical Literature in the ADS

    NASA Astrophysics Data System (ADS)

    Eichhorn, G.; Kurtz, M. J.; Accomazzi, A.; Grant, C. S.

    1997-12-01

    The Astrophysics Data System at http://adswww.harvard.edu is in the process of scanning the historical astronomical literature and making it available through the World Wide Web. We have scanned several volumes from the early 1800's of the "Astronomische Nachrichten", and the "Monthly Notices of the Royal Astronomical Society", the two oldest astronomical journals. We also have several of the early volumes of the "Astrophysical Journal" and the "Astronomical Journal" available. For all the journals that we cover, we have scanned volume 1. These early volumes can be accessed on a page-by-page basis. We plan to continue to scan this historical literature and complete these journals within the next year. We are also collaborating with a preservation project at Harvard University. This project will microfilm selected parts of astronomical Observatory reports. We plan to scan these microfilms to produce electronic images of these reports and put them on-line in the ADS. We hope to eventually cover most of the astronomical literature. In order to organize the scanned pages into articles, we need tables of contents (ToC). The early issues of the journals did not have printed ToC pages, so this needs to be done by hand. We do not have the financial resources to build these ToCs. We are looking for collaborators who would be willing to work with us in building these ToCs for the older journals and observatory reports. If you are interested in such a project, please contact the first author at gei@cfa.harvard.edu.

  1. Cordierite glass-ceramics as glaze materials for refractory forming tools

    NASA Astrophysics Data System (ADS)

    Miller, Frank Scott

    1999-11-01

    Glasses of the composition 2MgO·2Al2O 3·5SiO2 were successfully nucleated with additions of up to 8 mol% TiO2 to form fully crystalline glass-ceramic bodies. The predominant crystalline phase is a hexagonal stuffed quartz structure when the glasses are heated to temperatures near 950°C. This phase transforms to the hexagonal indialite phase at higher temperatures. The nucleating effect of the TiO2 addition results in a fine grained glass-ceramic. Both the glass transition temperature (Tg) and the melting temperature (Tm) decreased with a linear dependence on the amount of TiO 2 added to the glass. Glass of the composition 2MgO·2Al 2O3·5SiO2 + 8 mol% TiO2 was ground and air plasma sprayed onto low thermal expansion castable refractory concretes as a glaze. This glaze remained intact on the refractory concretes during crystallization. This behavior was observed during and after limited thermal cycling of the glazed refractory concretes, and also after high temperature heat treatment of the glazed refractory concretes.

  2. Soda-based glass fabricated from Thailand quartz sands doped with silver compound

    NASA Astrophysics Data System (ADS)

    Won-in, Krit; Dararutana, Pisutti

    2012-10-01

    Yellow colored glass which used for luxury art glass in ancient time was fabricated by the addition of silver compound into the molten glass. It was proved that it was actually silver nanoparticle technology. In this work, the SiO2-(Na2O,K2O)-CaO-B2O3-Al2O3-MgO glass system was prepared in the laboratory scale based on local quartz sands from Trat Province, eastern area of Thailand as the silica raw material. Various concentrations of silver nitrate were added. After the complete conventional melting process, the bubble-free yellow glasses were yielded. Physical and optical properties such as density, refractive index and optical absorption spectra were measured. Scanning electron microscope coupled with energy dispersive spectroscopy was carried out to study their morphology. The refractive indices and densities were increased as the increase of the silver contents. Electron micrographs showed the presence of silver nanoparticle in the glass matrix. UV-VIS spectra were in good agreement with that found from SEM measurements and corresponded with the universally accepted. It was also showed that the more brilliance on the surface of the glass products was obtained after firing with a gas torch.

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

    PubMed

    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. Application of glass-nonmetals of waste printed circuit boards to produce phenolic moulding compound.

    PubMed

    Guo, Jie; Rao, Qunli; Xu, Zhenming

    2008-05-01

    The aim of this study was to investigate the feasibility of using glass-nonmetals, a byproduct of recycling waste printed circuit boards (PCBs), to replace wood flour in production of phenolic moulding compound (PMC). Glass-nonmetals were attained by two-step crushing and corona electrostatic separating processes. Glass-nonmetals with particle size shorter than 0.07 mm were in the form of single fibers and resin powder, with the biggest portion (up to 34.6 wt%). Properties of PMC with glass-nonmetals (PMCGN) were compared with reference PMC and the national standard of PMC (PF2C3). When the adding content of glass-nonmetals was 40 wt%, PMCGN exhibited flexural strength of 82 MPa, notched impact strength of 2.4 kJ/m(2), heat deflection temperature of 175 degrees C, and dielectric strength of 4.8 MV/m, all of which met the national standard. Scanning electron microscopy (SEM) showed strong interfacial bonding between glass fibers and the phenolic resin. All the results showed that the use of glass-nonmetals as filler in PMC represented a promising method for resolving the environmental pollutions and reducing the cost of PMC, thus attaining both environmental and economic benefits.

  5. Osteoconductivity of modified fluorcanasite glass-ceramics for bone tissue augmentation and repair.

    PubMed

    Bandyopadhyay-Ghosh, S; Faria, P E P; Johnson, A; Felipucci, D N B; Reaney, I M; Salata, L A; Brook, I M; Hatton, P V

    2010-09-01

    Modified fluorcanasite glasses were fabricated by either altering the molar ratios of Na(2)O and CaO or by adding P(2)O(5) to the parent stoichiometric glass compositions. Glasses were converted to glass-ceramics by a controlled two-stage heat treatment process. Rods (2 mm x 4 mm) were produced using the conventional lost-wax casting technique. Osteoconductive 45S5 bioglass was used as a reference material. Biocompatibility and osteoconductivity were investigated by implantation into healing defects (2 mm) in the midshaft of rabbit femora. Tissue response was investigated using conventional histology and scanning electron microscopy. Histological and histomorphometric evaluation of specimens after 12 weeks implantation showed significantly more bone contact with the surface of 45S5 bioglass implants when compared with other test materials. When the bone contact for each material was compared between experimental time points, the Glass-Ceramic 2 (CaO rich) group showed significant difference (p = 0.027) at 4 weeks, but no direct contact at 12 weeks. Histology and backscattered electron photomicrographs showed that modified fluorcanasite glass-ceramic implants had greater osteoconductivity than the parent stoichiometric composition. Of the new materials, fluorcanasite glass-ceramic implants modified by the addition of P(2)O(5) showed the greatest stimulation of new mineralized bone tissue formation adjacent to the implants after 4 and 12 weeks implantation.

  6. Parasitic amorphous on single-domain crystal: Structural observations of silicate glass-ceramics

    NASA Astrophysics Data System (ADS)

    Takahashi, Yoshihiro; Yamazaki, Yoshiki; Ihara, Rie; Fujiwara, Takumi

    2013-01-01

    Glass-ceramics (GCs) are materials obtained from the crystallisation of functional phases in glass, and have a structure that the crystallised phase embedded in the glass matrix. Glass-forming oxides are commonly added to the functional phases to improve the stability of precursor glass; however, the issue of glass-ceramics permitting the presence of residual phases resulting from addition is required to be clarified. To elucidate this issue, we prepared `perfectly surface-crystallised' GC consisting of fresnoite-type Sr2TiSi2O8 from a non-stoichiometric glass and performed texture/morphology observations. Numerous SiO2-rich binodal-like nanospheres (~10 nm) were parasitic on the fresnoite single-crystal domains. The parasitic texture is considered to form via the following process: (i) binodal-type phase separation into stoichiometric fresnoite (crystalline matrix) and SiO2-rich phases (amorphous nanoparticles) and (ii) single-domain formation by surface crystallisation in the matrix. Furthermore, in terms of texture, the resulting GC differs from the GCs reported to date, i.e., inverse GC.

  7. Effect of Geopolymer filler in Glass Reinforced Epoxy (GRE) Pipe for Piping Application: Mechanical Properties

    NASA Astrophysics Data System (ADS)

    Firdaus Abu Hashim, Mohammad; Bakri Abdullah, Mohd Mustafa Al; Mohd Ruzaidi Ghazali, Che; Hussin, Kamarudin; Binhussain, Mohammed

    2016-06-01

    The present work is aimed to carry out the effect of geopolymer material which is fly ash as filler in the glass reinforced epoxy pipe on the micro structure of fly ash geopolymer, compression properties, and bulk density using the filament winding method. Conventional glass reinforced epoxy pipes has its own disadvantages such as high corrosion resistance at acidic environment and low strength which can be replaced by the composite pipes. Geopolymer is a type of amorphous alumino-silicate and can be synthesized by geopolymerization process. A series of glass reinforced epoxy pipe and glass reinforced epoxy pipe filled with 10 - 40 weight percentage geopolymer filler which is fly ash with 4 Molarity were prepared. Morphology of the raw material fly ash and fly ash based-geopolymer surface was characterized using scanning electron microscopy. It was found that the additions of fly ash at the beginning with 10 wt% are showing higher compressive strength than glass reinforced epoxy pipe without fly ash geopolymer filler. The compressive test of these series of samples was determined using Instron Universal Testing under compression mode. It was found that compressive strength for samples fly ash based-geopolymer filler are higher as compared to glass reinforced epoxy pipe without geopolymer filler. However, the compressive strength of glass reinforced epoxy pipe with fly ash geopolymer filler continues to decline when added to 20 wt% - 40 wt% of geopolymer filler loading. The results showed that the mixing of geopolymer materials in epoxy system can be obtained in this study.

  8. Electron anions and the glass transition temperature

    PubMed Central

    Sushko, Peter V.; Tomota, Yudai; Hosono, Hideo

    2016-01-01

    Properties of glasses are typically controlled by judicious selection of the glass-forming and glass-modifying constituents. Through an experimental and computational study of the crystalline, molten, and amorphous [Ca12Al14O32]2+ ⋅ (e–)2, we demonstrate that electron anions in this system behave as glass modifiers that strongly affect solidification dynamics, the glass transition temperature, and spectroscopic properties of the resultant amorphous material. The concentration of such electron anions is a consequential control parameter: It invokes materials evolution pathways and properties not available in conventional glasses, which opens a unique avenue in rational materials design. PMID:27559083

  9. Study Of Phase Separation In Glass

    NASA Technical Reports Server (NTRS)

    Neilson, George F.; Weinberg, Michael C.; Smith, Gary L.

    1989-01-01

    Report describes an experimental study of effect of hydroxide content on phase separation in soda/silica glasses. Ordinary and gel glasses melted at 1,565 degree C, and melts stirred periodically. "Wet" glasses produced by passing bubbles of N2 saturated with water through melts; "dry" glasses prepared in similar manner, except N2 dried before passage through melts. Analyses of compositions of glasses performed by atomic-absorption and index-of-refraction measurements. Authors conclude hydroxide speeds up phase separation, regardless of method (gel or ordinary) by which glass prepared. Eventually helps material scientists to find ways to control morphology of phase separation.

  10. High density fluoride glass calorimeter

    NASA Astrophysics Data System (ADS)

    Xie, Q.; Scheltzbaum, J.; Akgun, U.

    2014-04-01

    The unprecedented radiation levels in current Large Hadron Collider runs, and plans to even increase the luminosity creates a need for new detector technologies to be investigated. Quartz plates to replace the plastic scintillators in current LHC calorimeters have been proposed in recent reports. Quartz based Cherenkov calorimeters can solve the radiation damage problem, however light production and transfer have proven to be challenging. This report summarizes the results from a computational study on the performance of a high-density glass calorimeter. High-density, scintillating, fluoride glass, CHG3, was used as the active material. This glass has been developed specifically for hadron collider experiments, and is known for fast response time, in addition to high light yield. Here, the details of a Geant4 model for a sampling calorimeter prototype with 20 layers, and its hadronic as well as electromagnetic performances are reported.

  11. Elastic heterogeneity in metallic glasses.

    SciTech Connect

    Dmowski, , W.; Iwashita, T.; Chuang, C.-P.; Almer, J. D; Egami, T.; X-Ray Science Division; Univ. of Tennessee; ORNL

    2010-01-01

    When a stress is applied on a metallic glass it deforms following Hook's law. Therefore it may appear obvious that a metallic glass deforms elastically. Using x-ray diffraction and anisotropic pair-density function analysis we show that only about 3/4 in volume fraction of metallic glasses deforms elastically, whereas the rest of the volume is anelastic and in the experimental time scale deform without resistance. We suggest that this anelastic portion represents residual liquidity in the glassy state. Many theories, such as the free-volume theory, assume the density of defects in the glassy state to be of the order of 1%, but this result shows that it is as much as a quarter.

  12. Introduction to glass microstructuring techniques.

    PubMed

    Mazurczyk, Radoslaw; Mansfield, Colin D

    2013-01-01

    In this chapter an overview of manufacturing methods, leading to the fabrication of microstructures in glass substrates, is presented. Glass is a material of excellent optical properties, a very good electric insulator, biocompatible and chemically stable. In addition to its intrinsic qualities, glass can be processed with the use of manufacturing methods originating from the microelectronic industry. In this text two complete manufacturing protocols are described, each composed of standard microfabrication steps; namely, the deposition of masking layers, photolithographic patterning and pattern transfer via wet or dry etching. As a result, a set of building blocks is provided, allowing the manufacture of various microfluidic components that are frequently used in the domain of micro-total analysis system technology.

  13. Processing of bulk metallic glass.

    PubMed

    Schroers, Jan

    2010-04-12

    Bulk metallic glass (BMG) formers are multicomponent alloys that vitrify with remarkable ease during solidification. Technological interest in these materials has been generated by their unique properties, which often surpass those of conventional structural materials. The metastable nature of BMGs, however, has imposed a barrier to broad commercial adoption, particularly where the processing requirements of these alloys conflict with conventional metal processing methods. Research on the crystallization of BMG formers has uncovered novel thermoplastic forming (TPF)-based processing opportunities. Unique among metal processing methods, TPF utilizes the dramatic softening exhibited by a BMG as it approaches its glass-transition temperature and decouples the rapid cooling required to form a glass from the forming step. This article reviews crystallization processes in BMG former and summarizes and compares TPF-based processing methods. Finally, an assessment of scientific and technological advancements required for broader commercial utilization of BMGs will be made.

  14. Elastic Heterogeneity in Metallic Glasses

    NASA Astrophysics Data System (ADS)

    Dmowski, W.; Iwashita, T.; Chuang, C.-P.; Almer, J.; Egami, T.

    2010-11-01

    When a stress is applied on a metallic glass it deforms following Hook’s law. Therefore it may appear obvious that a metallic glass deforms elastically. Using x-ray diffraction and anisotropic pair-density function analysis we show that only about (3)/(4) in volume fraction of metallic glasses deforms elastically, whereas the rest of the volume is anelastic and in the experimental time scale deform without resistance. We suggest that this anelastic portion represents residual liquidity in the glassy state. Many theories, such as the free-volume theory, assume the density of defects in the glassy state to be of the order of 1%, but this result shows that it is as much as a quarter.

  15. Crystallization of niobium germanosilicate glasses

    SciTech Connect

    Santos, Rodrigo; Wondraczek, Lothar

    2010-01-15

    Niobium germanosilicate glasses are potential candidates for the fabrication of transparent glass ceramics with interesting non-linear optical properties. A series of glasses in the (Ge,Si)O{sub 2}-Nb{sub 2}O{sub 5}-K{sub 2}O system were prepared by melting and casting and their characteristic temperatures were determined by differential thermal analysis. Progressive replacement of GeO{sub 2} by SiO{sub 2} improved the thermal stability of the glasses. Depending on the composition and the crystallization heat-treatment, different nanocrystalline phases-KNbSi{sub 2}O{sub 7}, K{sub 3}Nb{sub 3}Si{sub 2}O{sub 13} and K{sub 3.8}Nb{sub 5}Ge{sub 3}O{sub 20.4} could be obtained. The identification and characterization of these phases were performed by X-ray diffraction and Raman spectroscopy. The 40 GeO{sub 2}-10 SiO{sub 2}-25 Nb{sub 2}O{sub 5}-25 K{sub 2}O (mol%) composition presented the higher ability for volume crystallization and its nucleation temperature was determined by the Marotta's method. An activation energy for crystal growth of {approx}529 kJ/mol and a nucleation rate of 9.7x10{sup 18} m{sup -3} s{sup -1} was obtained, for this composition. Transparent glass ceramics with a crystalline volume fraction of {approx}57% were obtained after a 2 h heat-treatment at the nucleation temperature, with crystallite sizes of {approx}20 nm as determined by transmission electron microscopy. - Abstract: TEM image and XRD pattern of the glass ceramic produced (circles indicate nanocrystals).

  16. Glasses for seeing beyond visible.

    PubMed

    Zhang, XiangHua; Bureau, Bruno; Lucas, Pierre; Boussard-Pledel, Catherine; Lucas, Jacques

    2008-01-01

    Conventional glasses based on oxides have a transparency limited by phonon absorption in the near IR region and have a limited interest for analyzing information located far beyond the visible. The IR spectral domain is nevertheless of prime interest, since it covers fundamental wavelength ranges used for thermal imaging as well as molecular vibrational signatures. Besides spectacular advances in the field of IR detectors, the main significant progresses are related to the development of IR glass optics, such as lenses or IR optical fibres. The field of IR glasses is almost totally dominated by glasses formed from heavy atoms such as the chalcogens S, Se and Te. Their transparency extends up to 12, 16 and 28 microm for sulfide-, selenide- and the new generation of telluride-based glasses, respectively. They cover the atmospheric transparency domains, 3-5 and 8-13 microm, respectively, at which the IR radiation can propagate allowing thermal imaging and night-vision operations through thick layers of atmosphere. The development of new glass compositions will be discussed on the basis of structural consideration with the objective of moulding low-cost lenses for IR cameras used, for instance, in car-driving assistance. Additionally, multimode, single-index, optical fibres operating in the 3 to 12 microm window developed for in situ remote evanescent-wave IR spectroscopy will also be mentioned. The detection of molecular IR signatures is applied to environmental monitoring for investigating the pollution of underground water with toxic molecules. The extension of this technique to the investigation of biomolecules in three different studies devoted to liver tissues analysis, bio-film formation, and cell metabolism will also be discussed. Finally we will mention the developments in the field of single-mode fibres operating around 10 mum for the Darwin space mission, which is aiming at discovering, signs of biological life in telluric earth-like exoplanets throughout

  17. Manufacturing unique glasses in space

    NASA Technical Reports Server (NTRS)

    Happe, R. P.

    1976-01-01

    An air suspension melting technique is described for making glasses from substances which to date have been observed only in the crystalline condition. A laminar flow vertical wind tunnel was constructed for suspending oxide melts that were melted using the energy from a carbon dioxide laser beam. By this method it is possible to melt many high-melting-point materials without interaction between the melt and crucible material. In addition, space melting permits cooling to suppress crystal growth. If a sufficient amount of under cooling is accompanied by a sufficient increase in viscosity, crystallization will be avoided entirely and glass will result.

  18. Molecular random tilings as glasses

    PubMed Central

    Garrahan, Juan P.; Stannard, Andrew; Blunt, Matthew O.; Beton, Peter H.

    2009-01-01

    We have recently shown that p-terphenyl-3,5,3′,5′-tetracarboxylic acid adsorbed on graphite self-assembles into a two-dimensional rhombus random tiling. This tiling is close to ideal, displaying long-range correlations punctuated by sparse localized tiling defects. In this article we explore the analogy between dynamic arrest in this type of random tilings and that of structural glasses. We show that the structural relaxation of these systems is via the propagation–reaction of tiling defects, giving rise to dynamic heterogeneity. We study the scaling properties of the dynamics and discuss connections with kinetically constrained models of glasses. PMID:19720990

  19. Antiferromagnetic inclusions in lunar glass

    USGS Publications Warehouse

    Thorpe, A.N.; Senftle, F.E.; Briggs, Charles; Alexander, Corrine

    1974-01-01

    The magnetic susceptibility of 11 glass spherules from the Apollo 15, 16, and 17 fines and two specimens of a relatively large glass spherical shell were studied as a function of temperature from room temperature to liquid helium temperatures. All but one specimen showed the presence of antiferromagnetic inclusions. Closely spaced temperature measurements of the magnetic susceptibility below 77 K on five of the specimens showed antiferromagnetic temperature transitions (Ne??el transitions). With the exception of ilmenite in one specimen, these transitions did not correspond to any transitions in known antiferromagnetic compounds. ?? 1974.

  20. Experimental studies of glass refining

    NASA Technical Reports Server (NTRS)

    Subramanian, R. S.; Cole, R.; Kondos, P.

    1984-01-01

    The basic components of the experimental apparatus were selected and acquired. Techniques were developed for the fabrication of the special crucibles necessary for the experiments. Arrangements were made for the analysis of glass and gas bubble samples for composition information. Donations of major equipment were received for this project from Owens, Illinois where a similar study had been conducted a few year ago. Decisions were made regarding the actual glass composition to be used, the gas to be used in the first experiments, and the temperatures at which the experiments should be conducted. A microcomputer was acquired, and work was begun on interfacing the video analyzer to it.

  1. Properties of unconventional lithium bismuthate glasses

    NASA Astrophysics Data System (ADS)

    Hazra, S.; Mandal, S.; Ghosh, A.

    1997-10-01

    Unconventional bismuthate glasses containing lithium oxide have been prepared by a conventional melt-quench technique. X-ray diffraction, scanning electron microscopy, and differential thermal analysis show that stable binary glasses of composition xLi2O-(100-x)Bi2O3 can be achieved for x=20-35 mol %. Systematic variation of the glass-transition temperature, density, and molar volume observed in these glasses indicates no significant structural change with composition. Differential thermal analysis and optical studies show that the strength of the glass network decreases with the increase of Li2O content in the glass matrix with a small deviation for the extra stable 30Li2O-70Bi2O3 glass composition. Studies of Raman spectra and molar volume ensure that all glasses are built up of [BiO6] octahedral units, while the influence of Li+ ions in the glass matrix is also confirmed from optical, Raman, and electrical studies. Wide transmitting window in the optical region having sharp cutoffs in both ultraviolet-visible and infrared regimes may make these glasses useful in spectral devices. High dielectric values in these glasses compared to glasses formed with conventional glass former can be attributed to the influence of the high polarizability of the unconventional network forming cations, Bi3+.

  2. Glass transition and enthalpy relaxation of amorphous lactose glass.

    PubMed

    Haque, Md Kamrul; Kawai, Kiyoshi; Suzuki, Toru

    2006-08-14

    The glass transition temperature, T(g), and enthalpy relaxation of amorphous lactose glass were investigated by differential scanning calorimetry (DSC) for isothermal aging periods at various temperatures (25, 60, 75, and 90 degrees C) below T(g). Both T(g) and enthalpy relaxation were found to increase with increasing aging time and temperature. The enthalpy relaxation increased approximately exponentially with aging time at a temperature (90 degrees C) close to T(g) (102 degrees C). There was no significant change observed in the enthalpy relaxation around room temperature (25 degrees C) over an aging period of 1month. The Kohlrausch-Williams-Watts (KWW) model was able to fit the experimental enthalpy relaxation data well. The relaxation distribution parameter (beta) was determined to be in the range 0.81-0.89. The enthalpy relaxation time constant (tau) increased with decreasing aging temperature. The observed enthalpy relaxation data showed that molecular mobility in amorphous lactose glass was higher at temperatures closer to T(g). Lactose glass was stable for a long time at 25 degrees C. These findings should be helpful for improving the processing and storage stability of amorphous lactose and lactose containing food and pharmaceutical products.

  3. Structural and optical properties of Ni added ZnO thin films deposited by sol-gel method

    NASA Astrophysics Data System (ADS)

    Murugan, R.; Vijayaprasath, G.; Mahalingam, T.; Anandhan, N.; Ravi, G.

    2014-04-01

    Pure and Ni added zinc oxide thin films were prepared by sol-gel method using spin-coating technique on glass substrates. The influences of nickel on ZnO thin films are characterized by Powder X-ray diffraction study. Pure and Ni added thin films are hexagonal wurtzite structure without any secondary phase in c-axis orientation. The SEM images of thin films show uniform sphere like particles covered completely on glass substrates. All the films exhibit transmittance of 85-95% in the visible range up to 800nm and cut-off wavelength observed at 394 nm corresponding to the fundamental absorption of ZnO. The photoluminescence property for pure and Ni added ZnO thin films has been studied and results are presented in detail.

  4. Structural and optical properties of Ni added ZnO thin films deposited by sol-gel method

    SciTech Connect

    Murugan, R.; Vijayaprasath, G.; Anandhan, N. E-mail: gravicrc@gmail.com; Ravi, G. E-mail: gravicrc@gmail.com; Mahalingam, T.

    2014-04-24

    Pure and Ni added zinc oxide thin films were prepared by sol-gel method using spin-coating technique on glass substrates. The influences of nickel on ZnO thin films are characterized by Powder X-ray diffraction study. Pure and Ni added thin films are hexagonal wurtzite structure without any secondary phase in c-axis orientation. The SEM images of thin films show uniform sphere like particles covered completely on glass substrates. All the films exhibit transmittance of 85-95% in the visible range up to 800nm and cut-off wavelength observed at 394 nm corresponding to the fundamental absorption of ZnO. The photoluminescence property for pure and Ni added ZnO thin films has been studied and results are presented in detail.

  5. Sol/Gel Processing Techniques for Glass Matrix Composites.

    DTIC Science & Technology

    1987-11-01

    development of a general technique (i.e., Pyrex is less susceptible to devitrification than SiO2 or TiO2 -SiO 2 ). In addition. the properties of these sol / gel ...of a sol / gel process for SIC 2 and SiO2 - TiO2 - together with a data base for their densification - are prerequisite to the successful fabrication of...S~%ad~ 5~ ~ ~ *~~~~;:>;::L-; 1: ’*~~’~ ’S. AFWL-TN-86-59 AFWL-TN- 86-59 00 SOL / GEL PROCESSING TECHNIQUES FOR GLASS MATRIX COMPOSITES 0) C. G

  6. Structures and optical properties of tellurite glasses and glass ceramics

    NASA Astrophysics Data System (ADS)

    Hart, Robert Theodore, Jr.

    The structures and optical properties of (K2O)15(Nb 2O5)15(TeO2)70 glass and glass ceramic have been studied in order to understand the second harmonic generation observed from the glass ceramic. We have used 93Nb NMR, Raman spectroscopy, differential scanning calorimetry, small angle x-ray scattering, transmission electron microscopy, and powder x-ray and neutron scattering. We find that there is a microstructure consistent with binodal phase separation leading to spherical inclusions ˜20 nm in size. Upon heat treatment, these domains become nanocrystals of K2Te 4O9. A theory of optical heterogeneity is used to describe the observed second harmonic generation which is ˜95 times more intense that quartz. The chi(2) value for this material is 3.0 x 10-9 esu. A second project has used 125Te and 17O NMR to study alkali tellurite glasses in the system (M2O) x(TeO2)10-x, where M = Li, Na or K and x = 1, 2 or 3. The 125Te results show that complex models of network modification are needed to explain the resulting spectra that include a distribution of polyhedral tellurite units at all compositions. The 17O results show that there is a clear distinction between bridging and non-bridging oxygen sites in tellurite crystals and that sophisticated NMR experiments should be able to distinguish them in the glasses. Further, we have used Extended Huckel theory tight-binding calculations to predict the 17O NMR shifts of SiO2, GeO 2 and TeO2. We find that these calculations allow accurate predictions of the chemical shifts based solely on the trend in valence orbital size, and that expensive calculations of electron currents need not be used for this application.

  7. IMPACTS OF SMALL COLUMN ION EXCHANGE STREAMS ON DWPF GLASS FORMULATION: KT08, KT09, AND KT10-SERIES GLASS COMPOSITIONS

    SciTech Connect

    Fox, K.; Edwards, T.

    2011-04-26

    well predicted by the DWPF model. No unexpected issues were encountered when uranium and thorium were added to the glasses with SCIX components. Increased Al{sub 2}O{sub 3} concentrations were not successful in preventing the formation of iron titanate crystals in the KT09-series glasses. Increased K{sub 2}O concentrations were successful in hindering the formation of iron titanates in some of the glasses after the canister centerline cooled (CCC) heat treatment. However, this result did not apply to all of the CCC versions of the glasses, indicating a compositional dependence of this effect. In addition, high concentrations of K{sub 2}O have been shown to hinder the ability of the DWPF durability and viscosity models to predict the performance of these glasses. The usefulness of increased K{sub 2}O concentrations in preventing the formation of iron titanates may therefore be limited. Further characterization was not performed for the KT09-series glasses since the type of crystallization formed was the characteristic of interest for these compositions. All of the KT10-series glasses were XRD amorphous, regardless of heat treatment. Chemical composition measurements showed that the glasses met the targeted concentrations for each oxide. In general, the measured PCT responses of the KT10-series glasses were well predicted by the DWPF models. The measured, normalized release values for silicon for some of the glasses fell above the 95% confidence interval for the predicted values; however, the PCT responses for these glasses remain considerably lower than that of the benchmark Environmental Assessment (EA) glass. The viscosities of the KT10-series glasses were generally well predicted by the DWPF model. The next step in this study will be to compile all of the data developed and further compare the measured properties and performance with those predicted by the current DWPF Product Composition Control System (PCCS) models. Recommendations will then be made as to which

  8. Joule-Thomson expansion of the charged AdS black holes

    NASA Astrophysics Data System (ADS)

    Ökcü, Özgür; Aydıner, Ekrem

    2017-01-01

    In this paper, we study Joule-Thomson effects for charged AdS black holes. We obtain inversion temperatures and curves. We investigate similarities and differences between van der Waals fluids and charged AdS black holes for the expansion. We obtain isenthalpic curves for both systems in the T- P plane and determine the cooling-heating regions.

  9. Measurement and Control of Glass Feedstocks

    SciTech Connect

    2005-08-01

    Laser-induced breakdown spectroscopy (LIBS) promises a new way for glass manufacturers to significantly increase productivity. By measuring the chemical makeup in raw materials and recycled glass cullet, LIBS can quickly detect contaminants and batch non...

  10. Properties and characteristics of optical glass

    SciTech Connect

    Marker, A.J. III.

    1988-01-01

    This book contains the proceedings of SPIE on properties and characteristics of optical glass. Topics covered include IR reflectance measurement of ion-implanted silica, specifying optical materials, and impurity absorption coefficient measurements in phosphate glass melted under oxidizing conditions.

  11. Biomedical engineering analysis of glass impact injuries.

    PubMed

    Sances, Anthony; Carlin, Fred H; Kumaresan, Srirangam; Enz, Bruce

    2002-01-01

    This article outlines the history, development, and safety aspects of glass and its use in motor vehicles. It traces the manufacture and describes the characteristics of laminated and tempered glass. It further compares the differences in injuries caused by impact with laminated and tempered glass. The development, use, and results of high penetration resistance (HPR) laminated glass for windshields are examined. Head and neck injuries from impact with glass and glazing structures are delineated. Results of studies with laminated and tempered glass are presented. The probability and severity of injuries occurring secondary to partial or full ejection of vehicle occupants are discussed, and the differences between the performance of laminated and tempered glass are highlighted. Current research to quantify head and neck injury parameters caused by glass impact during rollover is described. The biomechanics of head and neck injury assessment and the development of injury prediction parameters and reference values, respectively, are reviewed.

  12. High-Intensity Plasma Glass Melter

    SciTech Connect

    2004-01-01

    Modular high-intensity plasma melter promises improved performance, reduced energy use, and lower emissions. The glass industry has used the same basic equipment for melting glass for the past 100 years.

  13. High modulus high temperature glass fibers

    NASA Technical Reports Server (NTRS)

    Bacon, J. F.

    1973-01-01

    The search for a new high-modulus, high-temperature glass fiber involved the preparation of 500 glass compositions lying in 12 glass fields. These systems consisted primarily of low atomic number oxides and rare-earth oxides. Direct optical measurements of the kinetics of crystallization of the cordierite-rare earth system, for example, showed that the addition of rare-earth oxides decreased the rate of formation of cordierite crystals. Glass samples prepared from these systems proved that the rare-earth oxides made large specific contributions to the Young's modulus of the glasses. The best glasses have moduli greater than 21 million psi, the best glass fibers have moduli greater than 18 million psi, and the best glass fiber-epoxy resin composites have tensile strengths of 298,000 psi, compressive strengths of at least 220,000 psi, flexural strengths of 290,000 psi, and short-beam shear strengths of almost 17,000 psi.

  14. Glass microstructure capping and bonding techniques.

    PubMed

    Mazurczyk, Radoslaw; Mansfield, Colin D; Lygan, Marcin

    2013-01-01

    The capping of microfluidic features fabricated in glass substrates is achievable by various technological methods. Of the entire spectrum of possibilities (gluing, glass bonding via intermediate layers, pressure or plasma-assisted glass bonding, etc.) a detailed description of three techniques is presented here. The first is a low temperature PDMS-glass adhesion bonding, the second is medium temperature pressure assisted glass-glass bonding, and finally, high temperature glass-glass fusion bonding. All these protocols allow completion of the manufacturing process for a fully enclosed microfluidic chip. Nevertheless, as they are complementary rather than competing methods, they effectively extend the range of tools available to fabricate lab-on-a-chip microdevices. Each has its own merits and each could feasibly be used at different developmental stages of a given microfluidic device.

  15. Static Einstein-Maxwell Black Holes with No Spatial Isometries in AdS Space.

    PubMed

    Herdeiro, Carlos A R; Radu, Eugen

    2016-11-25

    We explicitly construct static black hole solutions to the fully nonlinear, D=4, Einstein-Maxwell-anti-de Sitter (AdS) equations that have no continuous spatial symmetries. These black holes have a smooth, topologically spherical horizon (section), but without isometries, and approach, asymptotically, global AdS spacetime. They are interpreted as bound states of a horizon with the Einstein-Maxwell-AdS solitons recently discovered, for appropriate boundary data. In sharp contrast to the uniqueness results for a Minkowski electrovacuum, the existence of these black holes shows that single, equilibrium, black hole solutions in an AdS electrovacuum admit an arbitrary multipole structure.

  16. Effects of ad placement and type on consumer responses to podcast ads.

    PubMed

    Ritter, Eric A; Cho, Chang-Hoan

    2009-10-01

    The purpose of this study was to understand the effects of podcast ad placement and podcast ad type on consumers' perceived intrusiveness, perceived irritation, attitude toward the ad, and ad avoidance. Our 2 x 2 (traditional ad vs. sponsorship by beginning vs. middle) experimental study found that sponsorships generated better consumer responses than did traditional ads and that podcast ads placed at the beginning of audio podcasts yielded better consumer responses than those placed in the middle. Implications for marketers and advertisers are discussed.

  17. Boundary conditions for conformally coupled scalar in AdS4

    NASA Astrophysics Data System (ADS)

    Oh, Jae-Hyuk

    2015-06-01

    We consider conformally coupled scalar with ɸ4 coupling in AdS4 and study its various boundary conditions on AdS boundary. We have obtained perturbative solutions of equation of motion of the conformally coupled scalar with power expansion order by order in ɸ4 coupling λ up to λ2 order. In its dual CFT, we get 2, 4 and 6 point functions by using this solution with Dirichlet and Neumann boundary conditions via AdS/CFT dictionary. We also consider marginal deformation on AdS boundary and get its on-shell and boundary effective actions.

  18. Heating-induced glass-glass and glass-liquid transformations in computer simulations of water

    SciTech Connect

    Chiu, Janet; Giovambattista, Nicolas; Starr, Francis W.

    2014-03-21

    Water exists in at least two families of glassy states, broadly categorized as the low-density (LDA) and high-density amorphous ice (HDA). Remarkably, LDA and HDA can be reversibly interconverted via appropriate thermodynamic paths, such as isothermal compression and isobaric heating, exhibiting first-order-like phase transitions. We perform out-of-equilibrium molecular dynamics simulations of glassy water using the ST2 model to study the evolution of LDA and HDA upon isobaric heating. Depending on pressure, glass-to-glass, glass-to-crystal, glass-to-vapor, as well as glass-to-liquid transformations are found. Specifically, heating LDA results in the following transformations, with increasing heating pressures: (i) LDA-to-vapor (sublimation), (ii) LDA-to-liquid (glass transition), (iii) LDA-to-HDA-to-liquid, (iv) LDA-to-HDA-to-liquid-to-crystal, and (v) LDA-to-HDA-to-crystal. Similarly, heating HDA results in the following transformations, with decreasing heating pressures: (a) HDA-to-crystal, (b) HDA-to-liquid-to-crystal, (c) HDA-to-liquid (glass transition), (d) HDA-to-LDA-to-liquid, and (e) HDA-to-LDA-to-vapor. A more complex sequence may be possible using lower heating rates. For each of these transformations, we determine the corresponding transformation temperature as function of pressure, and provide a P-T “phase diagram” for glassy water based on isobaric heating. Our results for isobaric heating dovetail with the LDA-HDA transformations reported for ST2 glassy water based on isothermal compression/decompression processes [Chiu et al., J. Chem. Phys. 139, 184504 (2013)]. The resulting phase diagram is consistent with the liquid-liquid phase transition hypothesis. At the same time, the glass phase diagram is sensitive to sample preparation, such as heating or compression rates. Interestingly, at least for the rates explored, our results suggest that the LDA-to-liquid (HDA-to-liquid) and LDA-to-HDA (HDA-to-LDA) transformation lines on heating are related

  19. 5. Headon view of looking glass aircraft. View to southwest. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. Head-on view of looking glass aircraft. View to southwest. - Offutt Air Force Base, Looking Glass Airborne Command Post, Looking Glass Aircraft, On Operational Apron covering northeast half of Project Looking Glass Historic District, Bellevue, Sarpy County, NE

  20. 3. General view showing rear of looking glass aircraft. View ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. General view showing rear of looking glass aircraft. View to north. - Offutt Air Force Base, Looking Glass Airborne Command Post, Looking Glass Aircraft, On Operational Apron covering northeast half of Project Looking Glass Historic District, Bellevue, Sarpy County, NE

  1. 4. View showing underside of wing, looking glass aircraft. View ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. View showing underside of wing, looking glass aircraft. View to north. - Offutt Air Force Base, Looking Glass Airborne Command Post, Looking Glass Aircraft, On Operational Apron covering northeast half of Project Looking Glass Historic District, Bellevue, Sarpy County, NE

  2. Potentially improved glasses from space environment

    NASA Technical Reports Server (NTRS)

    Nichols, R.

    1977-01-01

    The benefits of processing glasses in a low-gravity space environment are examined. Containerless processing, the absence of gravity driven convection, and lack of sedimentation are seen as potential advantages. Potential applications include the formation of glass-ceramics with a high content of active elements for ferromagnetic devices, the production of ultrapure chalcogenide glasses for laser windows and IR fiber optics, and improved glass products for use in optical systems and laser fusion targets.

  3. Granular packing as model glass formers

    NASA Astrophysics Data System (ADS)

    Wang, Yujie

    2017-01-01

    Static granular packings are model hard-sphere glass formers. The nature of glass transition has remained a hotly debated issue. We review recent experimental progresses in using granular materials to study glass transitions. We focus on the growth of glass order with five-fold symmetry in granular packings and relate the findings to both geometric frustration and random first-order phase transition theories.

  4. Volcanic glasses, their origins and alteration processes

    USGS Publications Warehouse

    Friedman, I.; Long, W.

    1984-01-01

    Natural glass can be formed by volcanic processes, lightning (fulgarites) burning coal, and by meteorite impact. By far the most common process is volcanic - basically the glass is rapidly chilled molten rock. All natural glasses are thermodynamically unstable and tend to alter chemically or to crystallize. The rate of these processes is determined by the chemical composition of the magma. The hot and fluid basaltic melts have a structure that allows for rapid crystal growth, and seldom forms glass selvages greater than a few centimeters thick, even when the melt is rapidly cooled by extrusion in the deep sea. In contrast the cooler and very viscous rhyolitic magmas can yield bodies of glass that are tens of meters thick. These highly polymerized magmas have a high silica content - often 71-77% SiO2. Their high viscosity inhibits diffusive crystal growth. Basalt glass in sea water forms an alteration zone called palagonite whose thickness increases linearly with time. The rate of diffusion of water into rhyolitic glass, which follows the relationship - thickness = k (time) 1 2, has been determined as a function of the glass composition and temperature. Increased SiO2 increases the rate, whereas increased CaO, MgO and H2O decrease the rate. The activation energy of water diffusion varies from about 19 to 22 kcal/mol. for the glasses studied. The diffusion of alkali out of rhyolite glass occurs simultaneously with water diffusion into the glass. The rate of devitrification of rhyolitic glass is a function of the glass viscosity, which in turn is a function of water content and temperature. Although all of the aforementioned processes tend to destroy natural glasses, the slow rates of these processes, particularly for rhyolitic glass, has allowed samples of glass to persist for 60 million years. ?? 1984.

  5. Germanate Glass Fiber Lasers for High Power

    DTIC Science & Technology

    2016-01-04

    germanate based glasses with a specific focus on glass stability during thermal- cycling which is representative of the steps required to fabricate a doped...evidence of crystallisation after thermal cycling , and is of a low enough loss to realize a fiber laser. The glass stability is demonstrated by...specific focus on glass stability during thermal- cycling which is representative of the steps required to fabricate a doped micro-structured germanate

  6. Digimarc Discover on Google Glass

    NASA Astrophysics Data System (ADS)

    Rogers, Eliot; Rodriguez, Tony; Lord, John; Alattar, Adnan

    2015-03-01

    This paper reports on the implementation of the Digimarc® Discover platform on Google Glass, enabling the reading of a watermark embedded in a printed material or audio. The embedded watermark typically contains a unique code that identifies the containing media or object and a synchronization signal that allows the watermark to be read robustly. The Digimarc Discover smartphone application can read the watermark from a small portion of printed image presented at any orientation or reasonable distance. Likewise, Discover can read the recently introduced Digimarc Barcode to identify and manage consumer packaged goods in the retail channel. The Digimarc Barcode has several advantages over the traditional barcode and is expected to save the retail industry millions of dollars when deployed at scale. Discover can also read an audio watermark from ambient audio captured using a microphone. The Digimarc Discover platform has been widely deployed on the iPad, iPhone and many Android-based devices, but it has not yet been implemented on a head-worn wearable device, such as Google Glass. Implementing Discover on Google Glass is a challenging task due to the current hardware and software limitations of the device. This paper identifies the challenges encountered in porting Discover to the Google Glass and reports on the solutions created to deliver a prototype implementation.

  7. 46 CFR 154.1320 - Sighting ports, tubular gauge glasses, and flat plate type gauge glasses.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Sighting ports, tubular gauge glasses, and flat plate type gauge glasses. 154.1320 Section 154.1320 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... glasses, and flat plate type gauge glasses. (a) Cargo tanks may have sighting ports as a secondary...

  8. 46 CFR 154.1320 - Sighting ports, tubular gauge glasses, and flat plate type gauge glasses.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Sighting ports, tubular gauge glasses, and flat plate type gauge glasses. 154.1320 Section 154.1320 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... glasses, and flat plate type gauge glasses. (a) Cargo tanks may have sighting ports as a secondary...

  9. 46 CFR 154.1320 - Sighting ports, tubular gauge glasses, and flat plate type gauge glasses.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Sighting ports, tubular gauge glasses, and flat plate type gauge glasses. 154.1320 Section 154.1320 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... glasses, and flat plate type gauge glasses. (a) Cargo tanks may have sighting ports as a secondary...

  10. 46 CFR 154.1320 - Sighting ports, tubular gauge glasses, and flat plate type gauge glasses.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Sighting ports, tubular gauge glasses, and flat plate type gauge glasses. 154.1320 Section 154.1320 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... glasses, and flat plate type gauge glasses. (a) Cargo tanks may have sighting ports as a secondary...

  11. 46 CFR 154.1320 - Sighting ports, tubular gauge glasses, and flat plate type gauge glasses.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Sighting ports, tubular gauge glasses, and flat plate type gauge glasses. 154.1320 Section 154.1320 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... glasses, and flat plate type gauge glasses. (a) Cargo tanks may have sighting ports as a secondary...

  12. Inseparability of photon-added Gaussian states

    SciTech Connect

    Li Hongrong; Li Fuli; Zhu Shiyao

    2007-06-15

    The inseparability of photon-added Gaussian states which are generated from two-mode Gaussian states by adding photons is investigated. According to the established inseparability conditions [New J. Phys. 7, 211 (2005); Phys. Rev. Lett. 96, 050503 (2006)], we find that even if a two-mode Gaussian state is separable, the photon-added Gaussian state becomes entangled when the purity of the Gaussian state is larger than a certain value. The lower bound of entanglement of symmetric photon-added Gaussian states is derived. The result shows that entanglement of the photon-added Gaussian states is involved with high-order moment correlations. We find that fidelity of teleporting coherent states cannot be raised by employing the photon-added Gaussian states as a quantum channel of teleportation.

  13. Electrophoretic Deposition of Chitosan/45S5 Bioactive Glass Composite Coatings Doped with Zn and Sr

    PubMed Central

    Miola, Marta; Verné, Enrica; Ciraldo, Francesca Elisa; Cordero-Arias, Luis; Boccaccini, Aldo R.

    2015-01-01

    In this research work, the original 45S5 bioactive glass was modified by introducing zinc and/or strontium oxide (6 mol%) in place of calcium oxide. Sr was added for its ability to stimulate bone formation and Zn for its role in bone metabolism, antibacterial properties, and anti-inflammatory effect. The glasses were produced by means of melting and quenching process. SEM and XRD analyses evidenced that Zr and Sr introduction did not modify the glass structure and morphology while compositional analysis (EDS) demonstrated the effective incorporation of these elements in the glass network. Bioactivity test in simulated body fluid (SBF) up to 1 month evidenced a reduced bioactivity kinetics for Zn-doped glasses. Doped glasses were combined with chitosan to produce organic/inorganic composite coatings on stainless steel AISI 316L by electrophoretic deposition (EPD). Two EPD processes were considered for coating development, namely direct current EPD (DC-EPD) and alternating current EPD (AC-EPD). The stability of the suspension was analyzed and the deposition parameters were optimized. Tape and bending tests demonstrated a good coating-substrate adhesion for coatings containing 45S5-Sr and 45S5-ZnSr glasses, whereas the adhesion to the substrate decreased by using 45S5-Zn glass. FTIR analyses demonstrated the composite nature of coatings and SEM observations indicated that glass particles were well integrated in the polymeric matrix, the coatings were fairly homogeneous and free of cracks; moreover, the AC-EPD technique provided better results than DC-EPD in terms of coating quality. SEM, XRD analyses, and Raman spectroscopy, performed after bioactivity test in SBF solution, confirmed the bioactive behavior of 45S5-Sr-containing coating while coatings containing Zn exhibited no hydroxyapatite formation. PMID:26539431

  14. Mineralogical and chemical analyses of ancient glass beads from Taiwan and their implications

    NASA Astrophysics Data System (ADS)

    Liou, Y. S.; Liu, Y. C.

    2015-12-01

    Large numbers of monochrome glass beads with different colors, shapes, and stylistics excavated from the archaeological sites of Taiwan, which were dated mainly from the 2nd century AD to the early Historical Period of Taiwan. Archaeologically, these glass beads were more prevalent in eastern and northern Taiwan and were generally believed to be non-native, as well as were brought into Taiwan through the maritime exchange and/or trade activities between Taiwan and Southeast Asia/China since the Neolithic Age. Nevertheless, ancient glass beads have been little studies in Taiwan, aspects of these glass beads are not well detailed. In this work, non-destructive micro-Raman spectroscopy and μXRF are used in combination to examine 56 ancient glass beads excavated from six archaeological sites, eastern Taiwan, to unravel the mineralogical and chemical compositions and to help decipher the raw materials used and the provenance of beads. Micro-Raman measurements indicate the presence of hematite, zincite, siderite, sphalerite, lead tin yellow type II, adularia, chalcedony, anatase, rutite, ankerite, graphite, calcite, etc. Hematite, zincite, siderite, sphalerite, lead tin yellow type II, and rutile were found to be colorants/opacifiers. Among these crystalline phases, lead tin yellow type II was first detected in the ancient glass bead unearthed from Taiwan, which is accordant with results of chemical analysis. The chemical results obtained by μXRF show SiO2, Al2O3, Na2O, K2O, MgO, CaO, and PbO as the most abundant oxides. It is found that Na2O, Na2O, K2O, Al2O3, and MgO are the main/minor fluxes. According to the results, the three most frequent types are mineral soda alumina glass, soda plant ash glass, and lead silicate glass. The provenance of ancient beads unearthed from archaeological sites of Taiwan is possibility of multiple sources.

  15. Electrophoretic Deposition of Chitosan/45S5 Bioactive Glass Composite Coatings Doped with Zn and Sr.

    PubMed

    Miola, Marta; Verné, Enrica; Ciraldo, Francesca Elisa; Cordero-Arias, Luis; Boccaccini, Aldo R

    2015-01-01

    In this research work, the original 45S5 bioactive glass was modified by introducing zinc and/or strontium oxide (6 mol%) in place of calcium oxide. Sr was added for its ability to stimulate bone formation and Zn for its role in bone metabolism, antibacterial properties, and anti-inflammatory effect. The glasses were produced by means of melting and quenching process. SEM and XRD analyses evidenced that Zr and Sr introduction did not modify the glass structure and morphology while compositional analysis (EDS) demonstrated the effective incorporation of these elements in the glass network. Bioactivity test in simulated body fluid (SBF) up to 1 month evidenced a reduced bioactivity kinetics for Zn-doped glasses. Doped glasses were combined with chitosan to produce organic/inorganic composite coatings on stainless steel AISI 316L by electrophoretic deposition (EPD). Two EPD processes were considered for coating development, namely direct current EPD (DC-EPD) and alternating current EPD (AC-EPD). The stability of the suspension was analyzed and the deposition parameters were optimized. Tape and bending tests demonstrated a good coating-substrate adhesion for coatings containing 45S5-Sr and 45S5-ZnSr glasses, whereas the adhesion to the substrate decreased by using 45S5-Zn glass. FTIR analyses demonstrated the composite nature of coatings and SEM observations indicated that glass particles were well integrated in the polymeric matrix, the coatings were fairly homogeneous and free of cracks; moreover, the AC-EPD technique provided better results than DC-EPD in terms of coating quality. SEM, XRD analyses, and Raman spectroscopy, performed after bioactivity test in SBF solution, confirmed the bioactive behavior of 45S5-Sr-containing coating while coatings containing Zn exhibited no hydroxyapatite formation.

  16. DURABLE GLASS FOR THOUSANDS OF YEARS

    SciTech Connect

    Jantzen, C.

    2009-12-04

    The durability of natural glasses on geological time scales and ancient glasses for thousands of years is well documented. The necessity to predict the durability of high level nuclear waste (HLW) glasses on extended time scales has led to various thermodynamic and kinetic approaches. Advances in the measurement of medium range order (MRO) in glasses has led to the understanding that the molecular structure of a glass, and thus the glass composition, controls the glass durability by establishing the distribution of ion exchange sites, hydrolysis sites, and the access of water to those sites. During the early stages of glass dissolution, a 'gel' layer resembling a membrane forms through which ions exchange between the glass and the leachant. The hydrated gel layer exhibits acid/base properties which are manifested as the pH dependence of the thickness and nature of the gel layer. The gel layer ages into clay or zeolite minerals by Ostwald ripening. Zeolite mineral assemblages (higher pH and Al{sup 3+} rich glasses) may cause the dissolution rate to increase which is undesirable for long-term performance of glass in the environment. Thermodynamic and structural approaches to the prediction of glass durability are compared versus Ostwald ripening.

  17. 7 CFR 3201.30 - Glass cleaners.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 15 2012-01-01 2012-01-01 false Glass cleaners. 3201.30 Section 3201.30 Agriculture... Items § 3201.30 Glass cleaners. (a) Definition. Cleaning products designed specifically for use in cleaning glass surfaces, such as windows, mirrors, car windows, and computer monitors. (b) Minimum...

  18. 7 CFR 3201.30 - Glass cleaners.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 15 2013-01-01 2013-01-01 false Glass cleaners. 3201.30 Section 3201.30 Agriculture... Items § 3201.30 Glass cleaners. (a) Definition. Cleaning products designed specifically for use in cleaning glass surfaces, such as windows, mirrors, car windows, and computer monitors. (b) Minimum...

  19. 7 CFR 3201.30 - Glass cleaners.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 15 2014-01-01 2014-01-01 false Glass cleaners. 3201.30 Section 3201.30 Agriculture... Items § 3201.30 Glass cleaners. (a) Definition. Cleaning products designed specifically for use in cleaning glass surfaces, such as windows, mirrors, car windows, and computer monitors. (b) Minimum...

  20. Method for milling and drilling glass

    NASA Technical Reports Server (NTRS)

    Rice, S. H. (Inventor)

    1980-01-01

    A process for machining glass by placing a rotating carbide working surface under minimum pressure against an area of glass to be worked is described. Concurrently the region between the working surface and the area of glass is wet with a lubricant consisting essentially of a petroleum carrier, a complex mixture of esters and a complex mixture of naturally occurring aromatic oils.