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At least 73 records · Page 4

Evolution of the structure and chemical composition of the interface between multi-component silicate glasses and yttria-stabilized zirconia after 40,000 h exposure in air at 800 °C

The chemical and structural stability of two commercial multicomponent silicate glasses (SCN and G6) in contact with yttria-stabilized zirconia (YSZ) was investigated after exposure times of up to 40,000 h in air at 800 °C. With exposure time, interfacial layers develop at the SCN-YSZ and G6-YSZ interfaces, which were characterized in detail using both quantitative chemical analysis and atomic-resolution imaging. At the SCN-YSZ interface, a Ca-Ba-Si-O reaction phase was found to grow by diffusion control. In G6-YSZ, Raman spectroscopy and electron microscopy revealed a disorganized interfacial reaction later between G6 and YSZ, and the occurrence of cubic to tetragonal to monoclinic phase transformations in YSZ. Finally, this microstructural evolution is discussed in terms of devitrification resistance of glass and diffusion processes at interfaces.

36 MATERIALS SCIENCE↗

Repairing cracked glass

Filing procedure consisting of machined lightweight fused-silica tiles coated with thin-layer of borosilicate glass produces homogeneous seal in thin glass. Procedure is useful in repairing glass envelopes, X-ray tub windows, Dewar flasks, and similar thin glass objects.

Helman, D. D.↗

Fluorescent discharge lamp

A rapidly illuminating fluorescent lamp 1,200 mm long and 32.5 mm in diameter with an interior conducting strip which is compatible with conventional fixtures and ballasts is described. The fluorescent lamp is composed of a linear glass tube, electrodes sealed at both ends, mercury and raregas sealed in the glass tube, a fluorescent substance clad on the inner walls of the glass tube, and a clad conducting strip extending the entire length of the glass tube in the axial direction on the inner surface of the tube.

Mukai, E.↗

Pulse Strengthened and Laser Edge Sealed Vacuum Insulation Glazing

A scalable, low-cost processing strategy for glass strengthening and sealing is proposed to improve the thermal performance of insulating glass units and develop innovative window technologies. In this project, a combination of large area photonic processing, additive manufacturing, and laser encapsulation techniques is reported to realize a vacuum glazing technology to meet the cost, performance, reliability, and throughput demands. A modeling framework for evaluating the mechanical and thermal response was established to verify the structural deformation and thermal conductance. Micro-size glass frits in printing ink and a continuous-wave laser curing were employed to allow the formation of a hermetic bonding layer and led to improvement of glass edge sealing. Various sealing parameters, including laser traveling speed, spot diameter, and laser power were optimized. The water seepage and mechanical strength of the resulting glass-to-glass bonding were examined as well. These results showcase the development of a practical vacuum insulating glazing with several unique features through a combination of photonic processing, laser encapsulation, and additive manufacturing.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Plastic-Sealed Hybrid Power Circuit Package

Proposed design for hybrid high-voltage power-circuit package uses molded plastic for hermetic sealing instead of glass-to-metal seal. New package used to house high-voltage regulators and solid-state switches for applications in aircraft, electric automobiles, industrial equipment, satellites, solarcell arrays, and other equipment in extreme environments.

Miller, W. N.↗

Thermally-Activated Metal-to-Glass Bonding

Hermetic seals formed easily by use of metallo-organic film. Metallo-organic film thermally bonded to glass and soldered or welded to form hermetic seal. Film applied as ink consisting of silver neodecanoate in xylene. Relative amounts of ingredients selected to obtain desired viscosity. Material applied by printing or even by scribing with pen. Sealing technique useful in making solar-cell modules, microelectronic packages, and other hermetic silicon devices.

Gallagher, B. D.↗

Alternate seal configuration for lithium primary cells

The problem of glass degradation in the glass-to-metal seals in lithium/sulfur dioxide cells is discussed. The glass degradation mechanism is attributed to lithium reacting with glass which is a result of deposition of lithium at the glass/metal/electrolyte interface. The worst degradation was observed when cells were stored in the inverted position. Alternate sealing methods were examined and a modified Ziegler seal is considered to be one of the best possible methods. The seal consists of a crimp type soft seal using a plastic annulus and a metal tube. Results of degradation tests are presented.

Kelley, J. A.↗

Sealing Out-Of-Round Tubes With O-Rings

Glass or ceramic tubes out-of-round sealed effectively by ordinary O-rings in caps of modified hydraulic fittings. In typical connection, O-ring squeezed between two surfaces having inward-opening slants of 5 degrees or 10 degrees. Slanted surfaces force ring inward, compressing it around tube. Connector metal fitting, tightened by hand around O-ring, seals O-ring against tube as much as 1/16 in. out of round. Modified connectors seal glass or ceramic tubes against gas or vacuum leakage in furnaces, vacuum systems, and tubes for glassblowing equipment.

Shlichta, Paul J.↗

COMBLE-ISLAS water isotopes in precipitation (COMBLEISLASISO)

During the measurement period, precipitation was sampled on daily to sub-daily basis with a sampling kit consiting of a clear plastic box (60x40x40 cm) mounted to a ground structure. Daily sampling lasted from 22 Feb to 24 Mar 2020. At a fixed time of day (10 UTC), samples were collected and the sampling box cleaned for the next sample. Additionally, during intense observations periods (IOPs) announced by ISLAS, ARMS scientists increased sampling frequency to sub-daily sampling. During the campaign period, 2 IOPs were conducted, with in total 12 samples taken. IOP1 lasted from 27 Feb 10 to 02 Mar 2020, and IOP2 lasted from 12 Mar to 14 Mar 2020. Solid precipitation in the box was then melted, transferred to an 8 ml glass vial, sealed and shipped to FARLAB (University of Bergen, Norway) for stable water isotope analysis. Measured stable isotope composition of precipitation samples will be related to conditions at other sampling locations, and at the evaporation site to inform about conservation of water isotope quantities. In the period from 22 Feb to 24 Mar, 23 daily samples were collected at 10 UTC for stable water isotope analysis. During the entire sampling period, a high variability of precipitation phase was encountered. Most samples were recovered in the form of graupel/snow (12 samples), as rain (7 samples), and the remaining samples fell as graupel, snow, rain or frozen rain. Precipitation amounts varied between <1 mm (26 Feb) and 140 mm (25 Feb) within the sampling box. Furthermore, higher-resolution sampling was conducted during 2 intense observation periods (IOPs). During IOP1, lasting from 27 Feb 10 UTC to 02 Mar 10 UTC, 7 samples were collected, all of them as solid phase precipitation. IOP2 lasted from 12 Mar 10 UTC to 14 Mar 09 UTC, and 5 samples (all as graupel/snow) were collected. Samples were processed according to FARLAB standard measurement procedures. In short, samples were transferred to 1.5 ml glass vials with rubber/PTFE septa (part #548-0907, VWR, USA). An autosampler (A0325, Picarro Inc) transferred ca. 2&micro;l per injection into a high-precision vapourizer (A0211, Picarro Inc, USA) heated to 110&deg;C. After blending with dry N2 (< 5 ppm H2O) the gas mixture was directed into the measurement cavity of a Cavity-Ring Down Spectrometer (L2140-i, Picarro Inc) for about 7 min with a typical water concentration of 20 000 ppm. Memory effects were reduced by two times measuring a vapour mixture at a mixing ratio of 50 000 ppm, obtained from 2 injections of 2 &micro;l for 5 min at the beginning of each new sample vial. Thereafter, another 6 injections of 2 &micro;l per sample were measured individually as described above, and averages of the last 5 injections were used for further processing. Three standards were measured at the beginning and end of each batch, including a drift standard DI2 (&delta;D: -50.72&plusmn;0.73 permil, &delta;18O: -7.63&plusmn;0.10 permil), and for calibration the laboratory standards GLW (&delta;D: -307.79&plusmn;0.75 permil, &delta;18O: -40.02&plusmn;0.07 permil) and EVAP2 (&delta;D: 9.52&plusmn;0.65 permil, &delta;18O: 1.81&plusmn;0.13 permil). A detailed calibration report is included with the final uploaded data set.

54 ENVIRONMENTAL SCIENCES↗

Guidelines and Specifications for Enhanced Durability Evaluation of Insulating Glass and Vacuum Insulating Glass Units

The National Renewable Energy Laboratory (NREL) has conducted research into durability of advanced fenestration technologies for almost thirty years. NREL has recently begun to research potential methods to enhance durability evaluation of present market insulating glass units (IGU). This document outlines a proposed process flow for adoption of these methods by interested parties. The proposed evaluation process flow described below is still a topic of active research at NREL as well as with industry partners. NREL will periodically update this document based on research results, both internal and external to NREL that may inform development of improved durability evaluation. This document is also meant to serve as a guideline for interested parties who may wish to engage in enhanced durability evaluation of IGU's both internally or with external testing laboratories. NREL will work to support adoption of the suggestions in this guideline by interested partners in the hope that these practices are more broadly adopted by the industry. Further research into this area will continue to inform both adaptations of this guideline as well as development of improved durability evaluation standards.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Microcracks, micropores, and their petrologic interpretation for 72415 and 15418

Lunar samples 72415 and 15418 have complex microstructures that indicate a series of fracturing and healing events. Both samples contain relatively few open microcracks but many sealed and healed microcracks. Dunite 72415 contains abundant healed cracks that formed tectonically, symplectic intergrowths spatially and probably genetically related to microcracks, and a cataclastic matrix that has been extensively sintered. Metamorphosed breccia 15418 contains many post-metamorphic healed cracks, large shock induced cracks that have been sealed with glass, and a few younger, thin, open shock induced cracks.

Richter, D.↗

Isoprenoid hydrocarbons produced by thermal alteration of Nostoc muscorum and Rhodopseudomonas spheroides

The potential of algae and photosynthetic bacteria to serve as precursors of kerogen was studied to determine what factors affect the relative rates of formation of precursor hydrocarbons. Cells of Nostoc muscorum and Rhodopseudomonas spheroides were subjected to thermal alteration (by heating samples in glass tubes sealed under nitrogen) for two, four, and twelve weeks. Both unextracted and extracted cells in the absence and presence of montmorillonite were investigated, and the isoprenoid hydrocarbons produced in these experiments were determined. Phytane and five isomeric phytenes were the main hydrocarbons observed; their relative rates of formation in the different experimental conditions are described. No phytadienes, pristane, or pristenes were detected.

Philp, R. P.↗

Electroexplosive device

An electroexplosive device is presented which employs a header having contact pins hermetically sealed with glass passing through from a connector end of the header to a cavity filled with a shunt layer of a new nonlinear resistive composition and a heat-sink layer of a new dielectric composition having good thermal conductivity and capacity. The nonlinear resistive layer and the heat-sink layer are prepared from materials by mixing with a low temperature polymerizing resin. The resin is dissolved in a suitable solvent and later evaporated. The resultant solid composite is ground into a powder, press formed into the header and cured (polymerized) at about 250 to 300 F.

Menichelli, V. J.↗

Performance characteristics and statistics of a laser initiated microdetonator

The test results of 320 units of the laser initiated microdetonator are summarized. The commercially fabricated units used a lead styphnate/lead azide/HMX (1 mg/17.5 mg/13.5 mg) explosive train design contained in a miniature aluminum can and completed with a glass-metal seal window. The test parameters were the high and low laser energy, high and low temperature, laser pulse duration, laser wavelength and nuclear radiation (5 x 10 to the 6th rads of 1 MeV gamma ray). The performance parameters were the laser energy for ignition and the actuation response time. Included also is a description of the development of a flexible, continuously advanced train of explosive devices by using the units, miniature optics and fiber optics.

Yang, L. C.↗