Unitary plate electrode

NASA Technical Reports Server (NTRS)

Rowlette, John J. (Inventor); Clough, Thomas J. (Inventor); Josefowicz, Jack Y. (Inventor); Sibert, John W. (Inventor)

1985-01-01

The unitary electrode (10) comprises a porous sheet (12) of fiberglass the strands (14) of which contain a coating (16) of conductive tin oxide. The lower portion of the sheet contains a layer (18) of resin and the upper layer (20) contains lead dioxide forming a positive active electrode on an electrolyte-impervious layer. The strands (14) form a continuous conduction path through both layers (16, 18). Tin oxide is prevented from reduction by coating the surface of the plate facing the negative electrode with a conductive, impervious layer resistant to reduction such as a thin film (130) of lead or graphite filled resin adhered to the plate with a layer (31) of conductive adhesive. The plate (10) can be formed by casting a molten resin from kettle (60) onto a sheet of glass wool (56) overlying a sheet of lead foil and then applying positive active paste from hopper (64) into the upper layer (68). The plate can also be formed by passing an assembly of a sheet ( 80) of resin, a sheet (86) of sintered glass and a sheet (90) of lead between the nip (92) of heated rollers (93, 95) and then filling lead oxide into the pores (116) of the upper layer (118).

Fabrication of Solid-State Multilayer Glass Capacitors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilke, Rudeger H. T.; Brown-Shaklee, Harlan James; Casias, Adrian L.

Alkali-free glasses show immense promise for the development of high-energy density capacitors. The high breakdown strengths on single-layer sheets of glass suggest the potential for improved energy densities over existing state-of-the art polymer capacitors. In this paper, we demonstrate the ability to package thin glass to make solid-state capacitors. Individual layers are bonded using epoxy, leading to capacitors that exhibit stable operation over the temperature range -55 °C to +65 °C. Here, this fabrication approach is scalable and allows for proof testing individual layers prior to incorporation of the stack, providing a blueprint for the fabrication of high-energy density capacitors.

Fabrication of Solid-State Multilayer Glass Capacitors

DOE PAGES

Wilke, Rudeger H. T.; Brown-Shaklee, Harlan James; Casias, Adrian L.; ...

2017-07-31

Alkali-free glasses show immense promise for the development of high-energy density capacitors. The high breakdown strengths on single-layer sheets of glass suggest the potential for improved energy densities over existing state-of-the art polymer capacitors. In this paper, we demonstrate the ability to package thin glass to make solid-state capacitors. Individual layers are bonded using epoxy, leading to capacitors that exhibit stable operation over the temperature range -55 °C to +65 °C. Here, this fabrication approach is scalable and allows for proof testing individual layers prior to incorporation of the stack, providing a blueprint for the fabrication of high-energy density capacitors.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

The Performance Prototype Trough (PPT) Concentrating Collector consists of four 80-foot modules in a 320-foot row. The collector was analyzed, including cost estimates and manufacturing processes to produce collectors in volumes from 100 to 100,000 modules per year. The four different reflector concepts considered were the sandwich reflector structure, sheet metal reflector structure, molded reflector structure, and glass laminate structure. The sheet metal and glass laminate structures are emphasized with their related structure concepts. A preliminary manufacturing plan is offered that includes: documentation of the manufacturing process with production flow diagrams; labor and material costs at various production levels; machinerymore » and equipment requirements including preliminary design specifications; and capital investment costs for a new plant. Of five reflector designs considered, the two judged best and considered at length are thin annealed glass and steel laminate on steel frame panel and thermally sagged glass. Also discussed are market considerations, costing and selling price estimates, design cost analysis and make/buy analysis. (LEW)« less

Efficiency of Moderated Neutron Lithium Glass Detectors Using Monte Carlo Techniques

NASA Astrophysics Data System (ADS)

James, Brian

2011-10-01

Due to national security concerns over the smuggling of special nuclear materials and the small supply of He-3 for use in neutron detectors, there is a great need for a new kind of neutron detector. Using Monte Carlo techniques I have been studying the use of lithium glass in varying configurations for neutron detectors. My research has included the effects of using a detector with two thin sheets of lithium at varying distances apart. I have also researched the effects of varying amounts of shielding a californium source with varying amounts of water. This is important since shielding would likely be used to make nuclear material more difficult to detect. The addition of one sheet of lithium-6 glass on the front surface of the detector significantly improves the efficiency for the detection of neutrons from a moderated fission source.

Method for heating, forming and tempering a glass sheet

DOEpatents

Boaz, Premakaran Tucker; Sitzman, Gary W.

1998-01-01

A method for heating, forming and tempering a glass sheet including the steps of heating at least one glass sheet to at least a first predetermined temperature, applying microwave energy to the glass sheet to heat the glass sheet to at least a second predetermined temperature, forming the glass sheet to a predetermined configuration, and cooling an outer surface of the glass sheet to at least a third predetermined temperature to temper the glass sheet.

Method for heating, forming and tempering a glass sheet

DOEpatents

Boaz, P.T.; Sitzman, G.W.

1998-10-27

A method for heating, forming and tempering a glass sheet is disclosed including the steps of heating at least one glass sheet to at least a first predetermined temperature, applying microwave energy to the glass sheet to heat the glass sheet to at least a second predetermined temperature, forming the glass sheet to a predetermined configuration, and cooling an outer surface of the glass sheet to at least a third predetermined temperature to temper the glass sheet. 2 figs.

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.

Graphene-silica composite thin films as transparent conductors.

PubMed

Watcharotone, Supinda; Dikin, Dmitriy A; Stankovich, Sasha; Piner, Richard; Jung, Inhwa; Dommett, Geoffrey H B; Evmenenko, Guennadi; Wu, Shang-En; Chen, Shu-Fang; Liu, Chuan-Pu; Nguyen, SonBinh T; Ruoff, Rodney S

2007-07-01

Transparent and electrically conductive composite silica films were fabricated on glass and hydrophilic SiOx/silicon substrates by incorporation of individual graphene oxide sheets into silica sols followed by spin-coating, chemical reduction, and thermal curing. The resulting films were characterized by SEM, AFM, TEM, low-angle X-ray reflectivity, XPS, UV-vis spectroscopy, and electrical conductivity measurements. The electrical conductivity of the films compared favorably to those of composite thin films of carbon nanotubes in silica.

Graphene-silica Composite Thin Films as Transparent Conductors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Watcharotone,S.; Dikin, D.; Stankovich, S.

2007-01-01

Transparent and electrically conductive composite silica films were fabricated on glass and hydrophilic SiO{sub x}/silicon substrates by incorporation of individual graphene oxide sheets into silica sols followed by spin-coating, chemical reduction, and thermal curing. The resulting films were characterized by SEM, AFM, TEM, low-angle X-ray reflectivity, XPS, UV-vis spectroscopy, and electrical conductivity measurements. The electrical conductivity of the films compared favorably to those of composite thin films of carbon nanotubes in silica.

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.

Method for heating and forming a glass sheet

DOEpatents

Boaz, Premakaran Tucker

1997-01-01

A method for heating and forming a glass sheet includes the steps of heating a glass sheet to at least a first predetermined temperature, applying microwave energy to the glass sheet to heat the glass sheet to at least a second predetermined temperature, cooling an outer surface of the glass sheet to at least a third predetermined temperature and forming the glass sheet using forming rollers to a predetermined configuration.

Large-area SnO{sub 2}: F thin films by offline APCVD

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Yan; Wu, Yucheng, E-mail: ycwu@hfut.edu.cn; Qin, Yongqiang

2011-08-15

Highlights: {yields} Large-area (1245 mm x 635 mm) FTO thin films were successfully deposited by offline APCVD process. {yields} The as-prepared FTO thin films with sheet resistance 8-11 {Omega}/{open_square} and direct transmittance more than 83% exhibited better than that of the online ones. {yields} The maximum quantum efficiency of the solar cells based on offline FTO substrate was 0.750 at wavelength 540 nm. {yields} The power of the solar modules using the offline FTO as glass substrates was 51.639 W, higher than that of the modules based on the online ones. -- Abstract: In this paper, we reported the successfulmore » preparation of fluorine-doped tin oxide (FTO) thin films on large-area glass substrates (1245 mm x 635 mm x 3 mm) by self-designed offline atmospheric pressure chemical vapor deposition (APCVD) process. The FTO thin films were achieved through a combinatorial chemistry approach using tin tetrachloride, water and oxygen as precursors and Freon (F-152, C2H4F2) as dopant. The deposited films were characterized for crystallinity, morphology (roughness) and sheet resistance to aid optimization of materials suitable for solar cells. We got the FTO thin films with sheet resistance 8-11 {Omega}/{open_square} and direct transmittance more than 83%. X-ray diffraction (XRD) characterization suggested that the as-prepared FTO films were composed of multicrystal, with the average crystal size 200-300 nm and good crystallinity. Further more, the field emission scanning electron microscope (FESEM) images showed that the films were produced with good surface morphology (haze). Selected samples were used for manufacturing tandem amorphous silicon (a-Si:H) thin film solar cells and modules by plasma enhanced chemical vapor deposition (PECVD). Compared with commercially available FTO thin films coated by online chemical vapor deposition, our FTO coatings show excellent performance resulting in a high quantum efficiency yield for a-Si:H solar cells and ideal open voltage and short circuit current for a-Si:H solar modules.« less

Study on Relationships between Internal Stress and Photodecomposition Properties of Thin Film Titanium Dioxide Photocatalyst

NASA Astrophysics Data System (ADS)

Miyamura, Amica; Kaneda, Kenji; Sato, Yasushi; Shigesato, Yuzo

Photocatalytic activities of titanium dioxide (TiO2) films deposited by rf sputtering were investigated from view points of their internal stress. TiO2 films were deposited on fused quartz glass or 100 μm thick micro-sheet glass substrates at room temperature, 200 or 400°C under various total gas pressures (Ptot) of 0.3~5.0 Pa with oxygen flow ratio [O2/(O2+Ar)] of 60% using a Ti metal target. Photocatalytic activity was evaluated by photodecomposition of acetaldehyde (CH3CHO) under UV illumination (black light lamp, 0.4 mW/cm2). Compressive internal stress was estimated by cantilever method using the micro-sheet glass, which clearly decreased from -2.1 to -0.1 GPa with the increase in the Ptot from 0.3 to 3.0 Pa. The films with the compressive stress less than -0.5 GPa performed the photocatalytic activity. Furthermore, compressive or tensile stress was applied by external force on the TiO2 films deposited on the curved micro sheet glasses by flattening these substrates after the deposition. The photodecomposition activity of the films with the slight compressive stress improved clearly, whereas the one of the films with the tensile stress degraded.

Method for heating and forming a glass sheet

DOEpatents

Boaz, P.T.

1997-08-12

A method for heating and forming a glass sheet includes the steps of heating a glass sheet to at least a first predetermined temperature, applying microwave energy to the glass sheet to heat the glass sheet to at least a second predetermined temperature, cooling an outer surface of the glass sheet to at least a third predetermined temperature and forming the glass sheet using forming rollers to a predetermined configuration. 5 figs.

Ultrathin Fluidic Laminates for Large-Area Façade Integration and Smart Windows.

PubMed

Heiz, Benjamin P V; Pan, Zhiwen; Lautenschläger, Gerhard; Sirtl, Christin; Kraus, Matthias; Wondraczek, Lothar

2017-03-01

Buildings represent more than 40% of Europe's energy demands and about one third of its CO 2 emissions. Energy efficient buildings and, in particular, building skins have therefore been among the key priorities of international research agendas. Here, glass-glass fluidic devices are presented for large-area integration with adaptive façades and smart windows. These devices enable harnessing and dedicated control of various liquids for added functionality in the building envelope. Combining a microstructured glass pane, a thin cover sheet with tailored mechanical performance, and a liquid for heat storage and transport, a flat-panel laminate is generated with thickness adapted to a single glass sheet in conventional windows. Such multimaterial devices can be integrated with state-of-the-art window glazings or façades to harvest and distribute thermal as well as solar energy by wrapping buildings into a fluidic layer. High visual transparency is achieved through adjusting the optical properties of the employed liquid. Also secondary functionality, such as chromatic windows, polychromatism, or adaptive energy uptake can be generated on part of the liquid.

Method for producing solar energy panels by automation

NASA Technical Reports Server (NTRS)

Evans, J. C., Jr. (Inventor)

1978-01-01

A solar cell panel was fabricated by photoetching a pattern of collector grid systems with appropriate interconnections and bus bar tabs into a glass or plastic sheet. These regions were then filled with a first, thin conductive metal film followed by a layer of a mixed metal oxide, such as InAsO or InSnO. The multiplicity of solar cells were bonded between the protective sheet at the sites of the collector grid systems and a back electrode substrate by conductive metal filled epoxy to complete the fabrication of an integrated solar panel.

A Visual Aid for Teaching Basic Concepts of Soil-Water Physics.

ERIC Educational Resources Information Center

Eshel, Amram

1997-01-01

Presents a visual aid designed to generate an image of water movement among soil particles using an overhead projector to teach the physical phenomena related to water status and water movement in the soil. Utilizes a base plate of thin transparent plastic, opaque plastic sheets, a plate of glass, and a colored aqueous solution. (AIM)

CO2 laser cutting of ultra thin (75 μm) glass based rigid optical solar reflector (OSR) for spacecraft application

NASA Astrophysics Data System (ADS)

Mishra, Shubham; Sridhara, N.; Mitra, Avijit; Yougandar, B.; Dash, Sarat Kumar; Agarwal, Sanjay; Dey, Arjun

2017-03-01

Present study reports for the first time laser cutting of multilayered coatings on both side of ultra thin (i.e., 75 μm) glass substrate based rigid optical solar reflector (OSR) for spacecraft thermal control application. The optimization of cutting parameters was carried out as a function of laser power, cutting speed and number of cutting passes and their effect on cutting edge quality. Systematic and in-detail microstructural characterizations were carried out by optical and scanning electron microscopy techniques to study the laser affected zone and cutting edge quality. Sheet resistance and water contact angle experiments were also conducted locally both prior and after laser cut to investigate the changes of electrical and surface properties, if any.

40 CFR 426.20 - Applicability; description of the sheet glass manufacturing subcategory.

Code of Federal Regulations, 2011 CFR

2011-07-01

... sheet glass manufacturing subcategory. 426.20 Section 426.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GLASS MANUFACTURING POINT SOURCE CATEGORY Sheet Glass Manufacturing Subcategory § 426.20 Applicability; description of the sheet glass...

40 CFR 426.20 - Applicability; description of the sheet glass manufacturing subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... sheet glass manufacturing subcategory. 426.20 Section 426.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GLASS MANUFACTURING POINT SOURCE CATEGORY Sheet Glass Manufacturing Subcategory § 426.20 Applicability; description of the sheet glass...

Advancements in ion beam figuring of very thin glass plates (Conference Presentation)

NASA Astrophysics Data System (ADS)

Civitani, M.; Ghigo, M.; Hołyszko, J.; Vecchi, G.; Basso, S.; Cotroneo, V.; DeRoo, C. T.; Schwartz, E. D.; Reid, P. B.

2017-09-01

The high-quality surface characteristics, both in terms of figure error and of micro-roughness, required on the mirrors of a high angular resolution x-ray telescope are challenging, but in principle well suited with a deterministic and non-contact process like the ion beam figuring. This process has been recently proven to be compatible even with very thin (thickness around 0.4mm) sheet of glasses (like D263 and Eagle). In the last decade, these types of glass have been investigated as substrates for hot slumping, with residual figure errors of hundreds of nanometres. In this view, the mirrors segments fabrication could be envisaged as a simple two phases process: a first replica step based on hot slumping (direct/indirect) followed by an ion beam figuring which can be considered as a post-fabrication correction method. The first ion beam figuring trials, realized on flat samples, showed that the micro-roughness is not damaged but a deeper analysis is necessary to characterize and eventually control/compensate the glass shape variations. In this paper, we present the advancements in the process definition, both on flat and slumped glass samples.

Test results for electron beam charging of flexible insulators and composites. [solar array substrates, honeycomb panels, and thin dielectric films

NASA Technical Reports Server (NTRS)

Staskus, J. V.; Berkopec, F. D.

1979-01-01

Flexible solar-array substrates, graphite-fiber/epoxy - aluminum honeycomb panels, and thin dielectric films were exposed to monoenergetic electron beams ranging in energy from 2 to 20 keV in the Lewis Research Center's geomagnetic-substorm-environment simulation facility to determine surface potentials, dc currents, and surface discharges. The four solar-array substrate samples consisted of Kapton sheet reinforced with fabrics of woven glass or carbon fibers. They represented different construction techniques that might be used to reduce the charge accumulation on the array back surface. Five honeycomb-panel samples were tested, two of which were representative of Voyager antenna materials and had either conductive or nonconductive painted surfaces. A third sample was of Navstar solar-array substrate material. The other two samples were of materials proposed for use on Intelsat V. All the honeycomb-panel samples had graphite-fiber/epoxy composite face sheets. The thin dielectric films were 2.54-micrometer-thick Mylar and 7.62-micrometer-thick Kapton.

Battery plate containing filler with conductive coating

NASA Technical Reports Server (NTRS)

Rowlette, John J. (Inventor)

1986-01-01

The plate (10) comprises a matrix or binder resin phase (12) in which is dispersed particulate, conductive tin oxide such as tin oxide coated glass fibers (14). A monopolar plate (11) is prepared by coating a layer (18) of electrolytically active material onto a surface of the plate (10). Tin oxide is prevented from reduction by coating a surface of the plate (10) with a conductive, impervious layer resistant to reduction such as a thin film (22) of lead adhered to the plate with a layer (21) of conductive adhesive. The plate (10) can be formed by casting a molten dispersion from mixer (36) onto a sheet (30) of lead foil or by passing an assembly of a sheet (41) of resin, a sheet (43) of fiberglass and a sheet (45) of lead between the nip of heated rollers (48, 50).

Battery plate containing filler with conductive coating

NASA Technical Reports Server (NTRS)

Rowlette, John J. (Inventor)

1985-01-01

The plate (10) comprises a matrix or binder resin phase (12) in which is dispersed particulate, conductive tin oxide such as tin oxide coated glass fibers (14). A monopolar plate (11) is prepared by coating a layer (18) of electrolytically active material onto a surface of the plate (10). Tin oxide is prevented from reduction by coating a surface of the plate (10) with a conductive, impervious layer resistant to reduction such as a thin film (22) of lead adhered to the plate with a layer (21) of conductive adhesive. The plate (10) can be formed by casting a molten dispersion from mixer (36) onto a sheet (30) of lead foil or by passing an assembly of a sheet (41) of resin, a sheet (43) of fiberglass and a sheet (45) of lead between the nip of heated rollers (48, 50).

Ultrathin Fluidic Laminates for Large‐Area Façade Integration and Smart Windows

PubMed Central

Heiz, Benjamin P. V.; Pan, Zhiwen; Lautenschläger, Gerhard; Sirtl, Christin; Kraus, Matthias

2016-01-01

Buildings represent more than 40% of Europe's energy demands and about one third of its CO2 emissions. Energy efficient buildings and, in particular, building skins have therefore been among the key priorities of international research agendas. Here, glass–glass fluidic devices are presented for large‐area integration with adaptive façades and smart windows. These devices enable harnessing and dedicated control of various liquids for added functionality in the building envelope. Combining a microstructured glass pane, a thin cover sheet with tailored mechanical performance, and a liquid for heat storage and transport, a flat‐panel laminate is generated with thickness adapted to a single glass sheet in conventional windows. Such multimaterial devices can be integrated with state‐of‐the‐art window glazings or façades to harvest and distribute thermal as well as solar energy by wrapping buildings into a fluidic layer. High visual transparency is achieved through adjusting the optical properties of the employed liquid. Also secondary functionality, such as chromatic windows, polychromatism, or adaptive energy uptake can be generated on part of the liquid. PMID:28331790

Welding/sealing glass-enclosed space in a vacuum

DOEpatents

Tracy, C.E.; Benson, D.K.

1996-02-06

A method of welding and sealing the edges of two juxtaposed glass sheets together to seal a vacuum space between the sheets comprises the steps of positioning a radiation absorbent material, such as FeO, VO{sub 2}, or NiO, between the radiation transmissive glass sheets adjacent the edges and then irradiating the absorbent material, preferably with a laser beam, through at least one of the glass sheets. Heat produced by the absorbed radiation in the absorbent material melts glass in the portions of both glass sheets that are adjacent the absorbent material, and the melted glass from both sheets flows together to create the weld when the melted glass cools and hardens. The absorbent material can be dissolved and diffused into the melted glass to the extent that it no longer absorbs enough energy to keep the glass melted, thus, with appropriate proportioning of absorbent material to source energy power and welding heat needed, the process can be made self-stopping. 8 figs.

Welding/sealing glass-enclosed space in a vacuum

DOEpatents

Tracy, C. Edwin; Benson, David K.

1996-01-01

A method of welding and sealing the edges of two juxtaposed glass sheets together to seal a vacuum space between the sheets comprises the steps of positioning a radiation absorbant material, such as FeO, VO.sub.2, or NiO, between the radiation transmissive glass sheets adjacent the edges and then irradiating the absorbant material, preferably with a laser beam, through at least one of the glass sheets. Heat produced by the absorbed radiation in the absorbant material melts glass in the portions of both glass sheets that are adjacent the absorbant material, and the melted glass from both sheets flows together to create the weld when the melted glass cools and hardens. The absorbant material can be dissolved and diffused into the melted glass to the extent that it no longer absorbs enough energy to keep the glass melted, thus, with appropriate proportioning of absorbant material to source energy power and welding heat needed, the process can be made self-stopping.

Estimate of the shielding effect on secondary cancer risk due to cone-beam CT in image-guided radiotherapy

NASA Astrophysics Data System (ADS)

Sung, Jiwon; Baek, Tae Seong; Yoon, Myonggeun; Kim, Dong Wook; Kim, Dong Hyun

2014-09-01

This study evaluated the effect of a simple shielding method using a thin lead sheet on the imaging dose caused by cone-beam computed tomography (CBCT) in image-guided radiation therapy (IGRT). Reduction of secondary doses from CBCT was measured using a radio-photoluminescence glass dosimeter (RPLGD) placed inside an anthropomorphic phantom. The entire body, except for the region scanned by using CBCT, was shielded by wrapping it with a 2-mm lead sheet. Changes in secondary cancer risk due to shielding were calculated using BEIR VII models. Doses to out-of-field organs for head-and-neck, chest, and pelvis scans were decreased 15 ~ 100%, 23 ~ 90%, and 23 ~ 98%, respectively, and the average reductions in lifetime secondary cancer risk due to the 2-mm lead shielding were 1.6, 11.5, and 12.7 persons per 100,000, respectively. These findings suggest that a simple, thin-lead-sheet-based shielding method can effectively decrease secondary doses to out-of-field regions for CBCT, which reduces the lifetime cancer risk on average by 9 per 100,000 patients.

Annealing effect on the structural, morphological and electrical properties of TiO2/ZnO bilayer thin films

NASA Astrophysics Data System (ADS)

Khan, M. I.; Imran, S.; Shahnawaz; Saleem, Muhammad; Ur Rehman, Saif

2018-03-01

The effect of annealing temperature on the structural, morphological and electrical properties of TiO2/ZnO (TZ) thin films has been observed. Bilayer thin films of TiO2/ZnO are deposited on FTO glass substrate by spray pyrolysis method. After deposition, these films are annealed at 573 K, 723 K and 873 K. XRD shows that TiO2 is present in anatase phase only and ZnO is present in hexagonal phase. No other phases of TiO2 and ZnO are present. Also, there is no evidence of other compounds like Zn-Ti etc. It also shows that the average grain size of TiO2/ZnO films is increased by increasing annealing temperature. AFM (Atomic force microscope) showed that the average roughness of TiO2/ZnO films is decreased at temperature 573-723 K and then increased at 873 K. The calculated average sheet resistivity of thin films annealed at 573 K, 723 K and 873 K is 152.28 × 102, 75.29 × 102 and 63.34 × 102 ohm-m respectively. This decrease in sheet resistivity might be due to the increment of electron concentration with increasing thickness and the temperature of thin films.

Standardization of blood smears prepared in transparent acetate: an alternative method for the microscopic diagnosis of malaria.

PubMed

Mello, Marcia B C; Luz, Francisco C; Leal-Santos, Fabio A; Alves, Eduardo R; Gasquez, Thamires M; Fontes, Cor J F

2014-06-17

Due to students' initial inexperience, slides are frequently broken and blood smears are damaged in microscopy training, leading to the need for their constant replacement. To minimize this problem a method of preparing blood smears on transparent acetate sheets was developed with the goal of implementing appropriate and more readily available teaching resources for the microscopic diagnosis of malaria. Acetate sheets derived from polyester were used to standardize the preparation and staining of thin and thick blood smears on transparent acetate sheets. Thick and thin blood smears were also prepared using the conventional method on glass slides. The staining was conducted using Giemsa staining for the thick and thin smears. Microscopic examination (1,000x) of the thin and thick blood smears prepared on transparent acetate produced high-quality images for both the parasites and the blood cells. The smears showed up on a clear background and with minimal dye precipitation. It was possible to clearly identify the main morphological characteristics of Plasmodium, neutrophils and platelets. After 12 months of storage, there was no change in image quality or evidence of fungal colonization. Preparation of thin and thick blood smears in transparent acetate for the microscopic diagnosis of malaria does not compromise the morphological and staining characteristics of the parasites or blood cells. It is reasonable to predict the applicability of transparent acetate in relevant situations such as the training of qualified professionals for the microscopic diagnosis of malaria and the preparation of positive specimens for competency assessment (quality control) of professionals and services involved in the diagnosis of malaria.

Effect of laser irradiation on the structural, morphological and electrical properties of polycrystalline TiO2 thin films

NASA Astrophysics Data System (ADS)

Khan, M. I.; Ali, Asghar

TiO2 thin film is deposited on glass substrate by sol-gel dip coating technique. After deposition, films were irradiated by continuous wave (CW) diode laser at an angle of 45°. XRD shows both the anatase and brookite phases of TiO2. Nano particles of regular and control sizes are appeared in SEM micrographs. Therefore, shape and size of nano particles can be control by using Laser irradiation. The average sheet resistivity of TiO2 thin film irradiated by 0, 2, 4 and 6 min are 6.72 × 105, 5.32 × 105, 3.44 × 105 and 4.95 × 105 (ohm-m) respectively, according to four point probe.

Optimization of SMA layers in composite structures to enhance damping

NASA Astrophysics Data System (ADS)

Haghdoust, P.; Cinquemani, S.; Lecis, N.; Bassani, P.

2016-04-01

The performance of lightweight structures can be severely affected by vibration. New design concepts leading to lightweight, slender structural components can increase the vulnerability of the components to failure due to excessive vibration. The intelligent approach to address the problem would be the use of materials which are more capable in dissipating the energy due to their high value of loss factor. Among the different materials available to achieve damping, much attention has been attached to the use of shape memory alloys (SMAs) because of their unique microstructure, leading to good damping capacity. This work describes the design and optimization of a hybrid layered composite structure for the passive suppression of flexural vibrations in slender and light structures. Embedding the SMA layers in composite structure allows to combine different properties: the lightness of the base composite (e.g. fiber glass), the mechanical strength of the insert of metallic material and the relevant damping properties of SMA, in the martensitic phase. In particular, we put our attention on embedding the CuZnAl in the form of thin sheet in a layered composite made by glass fiber reinforced epoxy. By appropriately positioning of the SMA sheets so that they are subjected to the maximum curvature, the damping of the hybrid system can be considerably enhanced. Accordingly analytical method for evaluating the energy dissipation of the thin sheets with different shapes and patterns is developed and is followed by a shape optimization based on genetic algorithm. Eventually different configurations of the hybrid beam structure with different patterns of SMA layer are proposed and compared in the term of damping capacity.

Slumped glass option for making the XEUS mirrors: preliminary design and ongoing developments

NASA Astrophysics Data System (ADS)

Ghigo, M.; Canestrari, R.; Proserpio, L.; Dell'Orto, E.; Basso, S.; Citterio, O.; Pareschi, G.; Parodi, Giancarlo

2008-07-01

The XEUS mission (X-ray Evolving-Universe Spectroscopy Mission) of ESA, in the present configuration has a mirror collecting area in the order of 5-6 m2 @ 1 keV, 2 m2 @ 7 keV and 1 m2 @ 10 keV. These large collecting areas could be obtained with a mirror assembly composed of a large number of high quality segments each being able to deliver the angular resolution requested by the mission or better. The XEUS telescope will fit in the fairing of an Ariane 5 ECA launcher and hence its diameter is presently of about 4.5 m. The request in terms of angular resolution of the telescope has been set to 5 arcsec with a goal of 2 arcsec. Due to the large size of the optics it is impossible to create closed shells like those used for XMM or Chandra and hence it will be necessary to assemble a large number of segments (for example of ~0.6 m x ~0.3 m size) to recreate the mirror shells. These segments will form a module, an optical sub-unit of the telescope. The modules will be assembled to form the whole mirror system. As for all the space missions, the limits imposed on the payload mass budget by the launcher is the main driver that force the use of very lightweight optics and this request is of course very challenging. For example, the current design for XEUS foresees a geometric-area/mass ratio better than about 30 cm2/kg. In this article is illustrated a possible approach for the realization of large size and lightweight X-ray mirrors that derive from an experience gained from a previous work made in INAF-OAB on the thermal slumping of thin glass optics. The process foresees the use of a mould having a good optical figure but opposite shape respect to the segment to be slumped. On the mould is placed an initially flat glass sheet. With a suitable thermal cycle the glass sheet is conformed to the mould shape. Once tested for acceptance the glass sheet it is then integrated into a module by means of a robotic arm having a feedback system to confirm the correct alignment. A study on different optical geometries using the classical Wolter I and Kirkpatrick-Baez configurations has been also performed to investigate the theoretical performances obtainable with optics made using very thin glass shells.

Pressure dependence of the electro-optic response function in partially exposed polymer dispersed ferroelectric liquid crystals

NASA Technical Reports Server (NTRS)

Parmar, D. S.; Holmes, H. K.

1993-01-01

Ferroelectric liquid crystals in a new configuration, termed partially exposed polymer dispersed ferroelectric liquid crystal (PEPDFLC), respond to external pressures and demonstrate pressure-induced electro-optic switching response. When the PEPDFLC thin film is sandwiched between two transparent conducting electrodes, one a glass plate and the other a flexible sheet such as polyvenylidene fluoride, the switching characteristics of the thin film are a function of the pressure applied to the flexible transparent electrode and the bias voltage across the electrodes. Response time measurements reveal a linear dependence of the change in electric field with external pressure.

Water ball collision

NASA Technical Reports Server (NTRS)

Fujimoto, K.

1986-01-01

What happens if a stainless steel ball hits a water ball in the weightless space ot the Universe? In other words, it was the objective of our experiments in the Space to observe the surface tension of liquid by means of making a solid collide with a liquid. Place a small volume of water between 2 glass sheets to make a thin water membrane: the 2 glass sheets cannot be separated unless an enormous force is applied. It is obvious from this phenomenom that the surface tension of water is far greater than presumed. On Earth, however, it is impossible in most cases to observe only the surface tension of liquid, because gravity always acts on the surface tension. Water and stainless steel balls were chosen the liquid and solids for the experiments. Because water is the liquid most familiar to us, its properties are well known. And it is also of great interest to compare its properties on the Earth with those in the weightless space.

Response of Honeycomb Core Sandwich Panel with Minimum Gage GFRP Face-Sheets to Compression Loading After Impact

NASA Technical Reports Server (NTRS)

McQuigg, Thomas D.; Kapania, Rakesh K.; Scotti, Stephen J.; Walker, Sandra P.

2011-01-01

A compression after impact study has been conducted to determine the residual strength of three sandwich panel constructions with two types of thin glass fiber reinforced polymer face-sheets and two hexagonal honeycomb Nomex core densities. Impact testing is conducted to first determine the characteristics of damage resulting from various impact energy levels. Two modes of failure are found during compression after impact tests with the density of the core precipitating the failure mode present for a given specimen. A finite element analysis is presented for prediction of the residual compressive strength of the impacted specimens. The analysis includes progressive damage modeling in the face-sheets. Preliminary analysis results were similar to the experimental results; however, a higher fidelity core material model is expected to improve the correlation.

Advanced solar concentrator: Preliminary and detailed design

NASA Technical Reports Server (NTRS)

Bell, D. M.; Maraschin, R. A.; Matsushita, M. T.; Erskine, D.; Carlton, R.; Jakovcevic, A.; Yasuda, A. K.

1981-01-01

A single reflection point focusing two-axis tracking paraboloidal dish with a reflector aperture diameter of approximately 11 m has a reflective surface made up of 64 independent, optical quality gores. Each gore is a composite of a thin backsilvered mirror glass face sheet continuously bonded to a contoured substrate of lightweight, rigid cellular glass. The use of largely self-supporting gores allows a significant reduction in the weight of the steel support structure as compared to alternate design concepts. Primary emphasis in the preliminary design package for the low-cost, low-weight, mass producible concentrator was placed on the design of the higher cost subsystems. The outer gore element was sufficiently designed to allow fabrication of prototype gores.

Development and Application of the High Bandwidth Powered Resonance Tube

DTIC Science & Technology

2005-11-09

arises in practical situations. In laser cutting, it is a common practice to remove the molten mass of metal with the help of high speed jet of air...cleaner and straighter laser cuts[Masuda and Nakamura, 19921. Thin glass sheets are prone to cracks when tempered by a cold air jet with impingement...Alvi, F. S., Shish, C., Elavarasan, R., Garg, G., and Krothapalli, A., 2003. Control of supersonic impinging jet flows using supersonic microjets

van der Waals epitaxial ZnTe thin film on single-crystalline graphene

NASA Astrophysics Data System (ADS)

Sun, Xin; Chen, Zhizhong; Wang, Yiping; Lu, Zonghuan; Shi, Jian; Washington, Morris; Lu, Toh-Ming

2018-01-01

Graphene template has long been promoted as a promising host to support van der Waals flexible electronics. However, van der Waals epitaxial growth of conventional semiconductors in planar thin film form on transferred graphene sheets is challenging because the nucleation rate of film species on graphene is significantly low due to the passive surface of graphene. In this work, we demonstrate the epitaxy of zinc-blende ZnTe thin film on single-crystalline graphene supported by an amorphous glass substrate. Given the amorphous nature and no obvious remote epitaxy effect of the glass substrate, this study clearly proves the van der Waals epitaxy of a 3D semiconductor thin film on graphene. X-ray pole figure analysis reveals the existence of two ZnTe epitaxial orientational domains on graphene, a strong X-ray intensity observed from the ZnTe [ 1 ¯ 1 ¯ 2] ǁ graphene [10] orientation domain, and a weaker intensity from the ZnTe [ 1 ¯ 1 ¯ 2] ǁ graphene [11] orientation domain. Furthermore, this study systematically investigates the optoelectronic properties of this epitaxial ZnTe film on graphene using temperature-dependent Raman spectroscopy, steady-state and time-resolved photoluminescence spectroscopy, and fabrication and characterization of a ZnTe-graphene photodetector. The research suggests an effective approach towards graphene-templated flexible electronics.

Cutting thin glass by femtosecond laser ablation

NASA Astrophysics Data System (ADS)

Shin, Hyesung; Kim, Dongsik

2018-06-01

The femtosecond laser ablation process for cutting thin aluminoborosilicate glass sheets of thickness 100 μm was investigated with emphasis on effective cutting speed (Veff) and mechanical strength of diced samples. The process parameters including the laser fluence (F), overlap ratio (r) of the laser beam and polarization direction were varied at a fixed pulse repetition rate f = 1 kHz to find the optimal process condition that maximizes Veff and edge strength. A three-point bending test was performed to evaluate the front-side and back-side bending (edge) strength of the laser-cut samples. Veff was proportional to F unless r exceeded a critical value, at which excessive energy began to be delivered at the same spot. The front-side edge strength was bigger than the back-side strength because of the back-side damages such as chipping. Good edge strength, as high as ∼280 MPa (front-side) and ∼230 MPa (back-side), was obtained at F = 19 J/m2, r = 0.99, with laser polarization vertical to the cutting path.

Rheological and secondary structural characterization of rice flour-zein composites for noodles slit from gluten-free sheeted dough.

PubMed

Jeong, Sungmin; Kim, Hee Won; Lee, Suyong

2017-04-15

Rice flour-zein composites in a hydrated viscoelastic state were utilized to compensate for the role of wheat gluten in gluten-free sheeted dough. The use of zein above its glass transition temperature was able to form a viscoelastic protein network of non-wheat dough with rice flour. The mixing stability and development time of the rice dough were positively increased with increasing levels of zein. The protein secondary structural analysis by FTIR spectroscopy demonstrated that the rice doughs with high levels of zein showed significant increases in β-sheet structures whose intensity was almost doubled by the use of 10% zein. The use of zein at more than 5% (w/w) successfully produced gluten-free dough sheets that could be slit into thin and long noodle strands. In addition, the composites were effective in improving the rheological characteristics of gluten-free noodle strands by increasing their maximum force to extension, compared to wheat-based noodles. Copyright © 2016 Elsevier Ltd. All rights reserved.

Microchannel laminated mass exchanger and method of making

DOEpatents

Martin, Peter M [Kennewick, WA; Bennett, Wendy D [Kennewick, WA; Matson, Dean W [Kennewick, WA; Stewart, Donald C [Richland, WA; Drost, Monte K [Pasco, WA; Wegeng, Robert S [Richland, WA; Perez, Joseph M [Richland, WA; Feng, Xiangdong [West Richland, WA; Liu, Jun [West Richland, WA

2003-03-18

The present invention is a microchannel mass exchanger having a first plurality of inner thin sheets and a second plurality of outer thin sheets. The inner thin sheets each have a solid margin around a circumference, the solid margin defining a slot through the inner thin sheet thickness. The outer thin sheets each have at least two header holes on opposite ends and when sandwiching an inner thin sheet. The outer thin sheets further have a mass exchange medium. The assembly forms a closed flow channel assembly wherein fluid enters through one of the header holes into the slot and exits through another of the header holes after contacting the mass exchange medium.

Microchannel laminated mass exchanger and method of making

DOEpatents

Martin, Peter M.; Bennett, Wendy D.; Matson, Dean W.; Stewart, Donald C.; Drost, Monte K.; Wegeng, Robert S.; Perez, Joseph M.; Feng, Xiangdong; Liu, Jun

2000-01-01

The present invention is a microchannel mass exchanger having a first plurality of inner thin sheets and a second plurality of outer thin sheets. The inner thin sheets each have a solid margin around a circumference, the solid margin defining a slot through the inner thin sheet thickness. The outer thin sheets each have at least two header holes on opposite ends and when sandwiching an inner thin sheet. The outer thin sheets further have a mass exchange medium. The assembly forms a closed flow channel assembly wherein fluid enters through one of the header holes into the slot and exits through another of the header holes after contacting the mass exchange medium.

Microchannel laminated mass exchanger and method of making

DOEpatents

Martin, Peter M [Kennewick, WA; Bennett, Wendy D [Kennewick, WA; Matson, Dean W [Kennewick, WA; Stewart, Donald C [Richland, WA; Drost, Monte K [Pasco, WA; Wegeng, Robert S [Richland, WA; Perez, Joseph M [Richland, WA; Feng, Xiangdong [West Richland, WA; Liu, Jun [West Richland, WA

2002-03-05

The present invention is a microchannel mass exchanger having a first plurality of inner thin sheets and a second plurality of outer thin sheets. The inner thin sheets each have a solid margin around a circumference, the solid margin defining a slot through the inner thin sheet thickness. The outer thin sheets each have at least two header holes on opposite ends and when sandwiching an inner thin sheet. The outer thin sheets further have a mass exchange medium. The assembly forms a closed flow channel assembly wherein fluid enters through one of the header holes into the slot and exits through another of the header holes after contacting the mass exchange medium.

Effect of S-doping on structural, optical and electrochemical properties of vanadium oxide thin films prepared by spray pyrolysis

NASA Astrophysics Data System (ADS)

Mousavi, M.; Kompany, A.; Shahtahmasebi, N.; Bagheri-Mohagheghi, M.-M.

2013-12-01

In this research, S-doped vanadium oxide thin films, with doping levels from 0 to 40 at.%, are prepared by spray pyrolysis technique on glass substrates. For electrochemical measurements, the films were deposited on florin-tin oxide coated glass substrates. The effect of S-doping on structural, electrical, optical and electrochemical properties of vanadium oxide thin films was studied. The x-ray diffractometer analysis indicated that most of the samples have cubic β-V2O5 phase structure with preferred orientation along [200]. With increase in the doping levels, the structure of the samples tends to be amorphous. The scanning electron microscopy images show that the structure of the samples is nanobelt-shaped and the width of the nanobelts decreases from nearly 100 to 40 nm with increase in the S concentration. With increase in the S-doping level, the sheet resistance and the optical band gap increase from 940 to 4015 kΩ/square and 2.41 to 2.7 eV, respectively. The cyclic voltammogram results obtained for different samples show that the undoped sample is expanded and the sample prepared at 20 at.% S-doping level has sharper anodic and cathodic peaks.

Thin transparent W-doped indium-zinc oxide (WIZO) layer on glass.

PubMed

Lee, Young-Jun; Lim, Byung-Wook; Kim, Joo-Hyung; Kim, Tae-Won; Oh, Byeong-Yun; Heo, Gi-Seok; Kim, Kwang-Young

2012-07-01

Annealing effect on structural and electrical properties of W-doped IZO (WIZO) films for thin film transistors (TFT) was studied under different process conditions. Thin WIZO films were deposited on glass substrates by RF magnetron co-sputtering technique using indium zinc oxide (10 wt.% ZnO-doped In2O3) and WO3 targets in room temperature. The post annealing temperature was executed from 200 degrees C to 500 degrees C under various O2/Ar ratios. We could not find any big difference from the surface observation of as grown films while it was found that the carrier density and sheet resistance of WIZO films were controlled by O2/Ar ratio and post annealing temperature. Furthermore, the crystallinity of WIZO film was changed as annealing temperature increased, resulting in amorphous structure at the annealing temperature of 200 degrees C, while clear In2O3 peak was observed for the annealed over 300 degrees C. The transmittance of as-grown films over 89% in visible range was obtained. As an active channel layer for TFT, it was found that the variation of resistivity, carrier density and mobility concentration of WIZO film decreased by annealing process.

Oxide-based thin film transistors for flexible electronics

NASA Astrophysics Data System (ADS)

He, Yongli; Wang, Xiangyu; Gao, Ya; Hou, Yahui; Wan, Qing

2018-01-01

The continuous progress in thin film materials and devices has greatly promoted the development in the field of flexible electronics. As one of the most common thin film devices, thin film transistors (TFTs) are significant building blocks for flexible platforms. Flexible oxide-based TFTs are well compatible with flexible electronic systems due to low process temperature, high carrier mobility, and good uniformity. The present article is a review of the recent progress and major trends in the field of flexible oxide-based thin film transistors. First, an introduction of flexible electronics and flexible oxide-based thin film transistors is given. Next, we introduce oxide semiconductor materials and various flexible oxide-based TFTs classified by substrate materials including polymer plastics, paper sheets, metal foils, and flexible thin glass. Afterwards, applications of flexible oxide-based TFTs including bendable sensors, memories, circuits, and displays are presented. Finally, we give conclusions and a prospect for possible development trends. Project supported in part by the National Science Foundation for Distinguished Young Scholars of China (No. 61425020), in part by the National Natural Science Foundation of China (No. 11674162).

The mechanical behavior of GLARE laminates for aircraft structures

NASA Astrophysics Data System (ADS)

Wu, Guocai; Yang, J.-M.

2005-01-01

GLARE (glass-reinforced aluminum laminate) is a new class of fiber metal laminates for advanced aerospace structural applications. It consists of thin aluminum sheets bonded together with unidirectional or biaxially reinforced adhesive prepreg of high-strength glass fibers. GLARE laminates offer a unique combination of properties such as outstanding fatigue resistance, high specific static properties, excellent impact resistance, good residual and blunt notch strength, flame resistance and corrosion properties, and ease of manufacture and repair. GLARE laminates can be tailored to suit a wide variety of applications by varying the fiber/resin system, the alloy type and thickness, stacking sequence, fiber orientation, surface pretreatment technique, etc. This article presents a comprehensive overview of the mechanical properties of various GLARE laminates under different loading conditions.

Thin Film Electrodes for Rare Event Detectors

NASA Astrophysics Data System (ADS)

Odgers, Kelly; Brown, Ethan; Lewis, Kim; Giordano, Mike; Freedberg, Jennifer

2017-01-01

In detectors for rare physics processes, such as neutrinoless double beta decay and dark matter, high sensitivity requires careful reduction of backgrounds due to radioimpurities in detector components. Ultra pure cylindrical resistors are being created through thin film depositions onto high purity substrates, such as quartz glass or sapphire. By using ultra clean materials and depositing very small quantities in the films, low radioactivity electrodes are produced. A new characterization process for cylindrical film resistors has been developed through analytic construction of an analogue to the Van Der Pauw technique commonly used for determining sheet resistance on a planar sample. This technique has been used to characterize high purity cylindrical resistors ranging from several ohms to several tera-ohms for applications in rare event detectors. The technique and results of cylindrical thin film resistor characterization will be presented.

A Rapid Deposition of Fluorine Doped Zinc Oxide Using the Atmospheric Pressure Chemical Vapour Deposition Method

NASA Astrophysics Data System (ADS)

Najafi, Navid; Rozati, S. M.

2018-03-01

Fluorine-doped zinc oxide (FZO) (ZnO:F) thin films were manufactured by atmospheric pressure chemical vapor deposition (APCVD) on glass substrates using zinc acetate dihydrate [C4H6O4Zn·2H2O, ZnAc] and ammonium fluoride (NH4F) as the source of fluorine with deposition duration of only 120 s for each sample. The effects of different amounts of fluorine as the dopant on the structural, electrical and optical properties of FZO thin films were investigated. The results show a polycrystalline structure at higher temperatures compared to amorphous structure at lower temperatures. The x-ray diffraction patterns of the polycrystalline films were identified as a hexagonal wurtzite structure of zinc oxide (ZnO) with the (002) preferred orientation. Also, the sheet resistance decreased from 17.8 MΩ/□ to 28.9 KΩ/□ for temperatures 325°C to 450°C, respectively. In order to further decrease the sheet resistance of the undoped ZnO thin films, fluorine was added using NH4F as the precursor, and again a drastic change in sheet resistance of only 17.7 Ω/□ was obtained. Based on the field emission scanning electron microscopy images, the fluorine concentration in CVD source is an important factor affecting the grain size and modifies electrical parameters. Ultraviolet-visible measurements revealed reduction of transparency of the layers with increasing fluorine as the dopant.

Effect of vacuum thermal annealing on a molybdenum bilayer back contact deposited by radio-frequency magnetron sputtering for chalcogenide- and kesterite-based solar cells

NASA Astrophysics Data System (ADS)

Liu, Xiaolei; Cui, Hongtao; Hao, Xiaojing; Huang, Shujuan; Conibeer, Gavin

2017-12-01

Molybdenum (Mo) thin films are still a dominant choice for the back contact layer of Cu(In,Ga)Se2 (CIGS) and Cu2ZnSnS4 (CZTS) solar cells. This paper presents a review of Mo back contacts for CIGS and CZTS solar cells, including the requirements for a good back contact, the reason for the choice of Mo, and post-treatment. Additionally, a Mo bilayer back contact was fabricated by varying the argon (Ar) pressure during sputtering to provide both low resistivity and good adhesion to the soda-lime glass substrate. The effects of vacuum thermal annealing on the electrical, morphological and structural properties of the Mo bilayer were also investigated. Vacuum thermal annealing was seen to densify the Mo bilayer, reduce the sheet resistance, and improve the bilayer's adhesion to the soda-lime glass. The Mo bilayer back contact with a low sheet resistance of 0.132 Ω/□ and strong adhesion was made for chalcogenide- and kesterite-based solar cells.

Structural, morphological and optical studies of F doped SnO2 thin films

NASA Astrophysics Data System (ADS)

Chandel, Tarun; Thakur, Vikas; Dwivedi, Shailendra Kumar; Zaman, M. Burhanuz; Rajaram, Poolla

2018-05-01

Highly conducting and transparent FTO (flourine doped tin Oxide) thin films were grown on the glass substrates using a low cost spray pyrolysis technique. The films were characterized for their structural, morphological and optical studies using XRD, SEM and UV-Vis spectroscopy. XRD studies show that the FTO films crystallize in Tetragonal cassiterite structure. Morphological analysis using SEM show that the films are uniformly covered with spherical grains albeit high in surface roughness. The average optical transmission greater than 80% in the visible region along with the appearance of interference fringes in the transmission curves confirms the high quality of the films. Electrical studies show that the films exhibit sheet resistance below 10 Ω ϒ-1.

Method of fabricating an article with cavities. [with thin bottom walls

NASA Technical Reports Server (NTRS)

Dale, W. J.; Jurscaga, G. M. (Inventor)

1974-01-01

An article having a cavity with a thin bottom wall is provided by assembling a thin sheet, for example, a metal sheet, adjacent to the surface of a member having one or more apertures. A bonding adhesive is interposed between the thin sheet and the subadjacent member, and the thin sheet is subjected to a high fluid pressure. In order to prevent the differential pressure from being exerted against the thin sheet, the aperture is filled with a plug of solid material having a linear coefficient of thermal expansion higher than that of the member. When the assembly is subjected to pressure, the material is heated to a temperature such that its expansion exerts a pressure against the thin sheet thus reducing the differential pressure.

Transparent, Conductive Coatings Developed for Arc-Proof Solar Arrays

NASA Technical Reports Server (NTRS)

1996-01-01

Transparent, conductive thin-film coatings have many potential applications where a surface must be able to dissipate electrical charges without sacrificing its optical properties. Such applications include automotive and aircraft windows, heat mirrors, optoelectronic devices, gas sensors, and solar cell array surfaces for space applications. Many spacecraft missions require that solar cell array surfaces dissipate charges in order to avoid damage such as electronic upsets, formation of pinholes in the protective coatings on solar array blankets, and contamination due to deposition of sputtered products. In tests at the NASA Lewis Research Center, mixed thin-films of sputter-deposited indium tin oxide (ITO) and magnesium fluoride (MgF2) that could be tailored to the desired sheet resistivity, showed transmittance values of greater than 90 percent. The samples evaluated were composed of mixed, thin-film ITO/MgF2 coatings, with a nominal thickness of 650 angstroms, deposited onto glass substrates. Preliminary results indicated that these coatings were durable to vacuum ultraviolet radiation and atomic oxygen. These coatings show promise for use on solar array surfaces in polar low-Earth-orbit environments, where a sheet resistivity of less than 10(exp 8)/square is required, and in geosynchronous orbit environments, where a resistivity of less than 10(exp 9)/square is required.

Printable Single-Crystal Silicon Micro/Nanoscale Ribbons, Platelets and Bars Generated from Bulk Wafers

DTIC Science & Technology

2007-08-28

enables high yield integration onto wafers, glass plates, plastic sheets, rubber slabs or other surfaces. As one application example, bottom gate thin... EPDMS 1m2Si ESi 1m2PDMS 23 is the critical strain for buck- ling, epre is the degree of prestrain, k0 and A0 are...Young’s modulus of Si and PDMS. The following values were used to yield the calcualted value of it (i.e., 84 lm): ESi = 160 GPa, EPDMS = 2 MPa, mPDMS

Going for green

NASA Astrophysics Data System (ADS)

Extance, Andy

2010-05-01

Thousands of times per second a point of light turns on and off, moving side to side, top to bottom. It is a rhythm that ticks around the world, illuminating living rooms and office desks in the process. However, the cathode-ray TVs and monitors that metronomically fire electron guns at viewers - who are shielded only by thin sheets of glass - are rapidly being replaced by flat-screen technologies. Yet as the creation of images using scanning electron beams fades into history, a new form of technology is emerging that builds up pictures by scanning with light.

Highly Transparent and UV-Resistant Superhydrophobic SiO2-Coated ZnO Nanorod Arrays

PubMed Central

2015-01-01

Highly transparent and UV-resistant superhydrophobic arrays of SiO2-coated ZnO nanorods are prepared in a sequence of low-temperature (<150 °C) steps on both glass and thin sheets of PET (2 × 2 in.2), and the superhydrophobic nanocomposite is shown to have minimal impact on solar cell device performance under AM1.5G illumination. Flexible plastics can serve as front cell and backing materials in the manufacture of flexible displays and solar cells. PMID:24495100

Improvements in processing characteristics and engineering properties of wood flour-filled high density polyethylene composite sheeting in the presence of hollow glass microspheres

Treesearch

Baris Yalcin; Steve E Amos; Andrew S D Souza; Craig M Clemons; I Sedat Gunes; Troy K Ista

2012-01-01

Hollow glass microspheres were introduced into wood flour/high density polyethylene composites by melt compounding in a twin-screw extruder. The prepared composites were subsequently converted to extruded profiles in order to obtain composite sheeting. The presence of hollow glass microspheres highly reduced the density of the extruded sheets down to 0.9 g/cc, while...

Geometry of thin liquid sheet flows

NASA Technical Reports Server (NTRS)

Chubb, Donald L.; Calfo, Frederick D.; Mcconley, Marc W.; Mcmaster, Matthew S.; Afjeh, Abdollah A.

1994-01-01

Incompresible, thin sheet flows have been of research interest for many years. Those studies were mainly concerned with the stability of the flow in a surrounding gas. Squire was the first to carry out a linear, invicid stability analysis of sheet flow in air and compare the results with experiment. Dombrowski and Fraser did an experimental study of the disintegration of sheet flows using several viscous liquids. They also detected the formulation of holes in their sheet flows. Hagerty and Shea carried out an inviscid stability analysis and calculated growth rates with experimental values. They compared their calculated growth rates with experimental values. Taylor studied extensively the stability of thin liquid sheets both theoretically and experimentally. He showed that thin sheets in a vacuum are stable. Brown experimentally investigated thin liquid sheet flows as a method of application of thin films. Clark and Dumbrowski carried out second-order stability analysis for invicid sheet flows. Lin introduced viscosity into the linear stability analysis of thin sheet flows in a vacuum. Mansour and Chigier conducted an experimental study of the breakup of a sheet flow surrounded by high-speed air. Lin et al. did a linear stability analysis that included viscosity and a surrounding gas. Rangel and Sirignano carried out both a linear and nonlinear invisid stability analysis that applies for any density ratio between the sheet liquid and the surrounding gas. Now there is renewed interest in sheet flows because of their possible application as low mass radiating surfaces. The objective of this study is to investigate the fluid dynamics of sheet flows that are of interest for a space radiator system. Analytical expressions that govern the sheet geometry are compared with experimental results. Since a space radiator will operate in a vacuum, the analysis does not include any drag force on the sheet flow.

Electrical transport properties of spray deposited transparent conducting ortho-Zn2SnO4 thin films

NASA Astrophysics Data System (ADS)

Ramarajan, R.; Thangaraju, K.; Babu, R. Ramesh; Joseph, D. Paul

2018-04-01

Ortho Zinc Stannate (Zn2SnO4) exhibits excellent electrical and optical properties to serve as alternate transparent electrode in optoelectronic devices. Here we have optimized ortho-Zn2SnO4 thin film by spray pyrolysis method. Deposition was done onto a pre-heated glass substrate at a temperature of 400 °C. The XRD pattern indicated films to be polycrystalline with cubic structure. The surface of films had globular and twisted metal sheet like morphologies. Films were transparent in the visible region with band gap around 3.6 eV. Transport properties were studied by Hall measurements at 300 K. Activation energies were calculated from Arrhenius's plot from temperature dependent electrical measurements and the conduction mechanism is discussed.

Biaxial deformation behaviour of poly-ether-ether-ketone

NASA Astrophysics Data System (ADS)

Turner, Josh; Menary, Gary; Martin, Peter

2018-05-01

The biaxial tensile properties of thin poly-ether-ether-ketone (PEEK) films are presented. Investigation into the biaxial mechanical behaviour of PEEK films will provide a preliminary insight into the anticipated stress/strain response, and potential suitability, to the possible fabrication of thin walled parts through stretch blow moulding and thermoforming processes - with the multi-axial state of strain imposed onto the heated thermoplastic sheet representative of the expected strain history experienced during these material forming processes. Following identification of the prospective forming temperature window, the biaxial mechanical behaviour of the material is characterized under differing modes of deformation, at a nominal strain rate of 1 s-1. The temperature dependence is outlined within - with an appreciable increase in flow behaviour correlated with specimen temperature exceeding its glass transition temperature (Tg).

Studying the influence of substrate conductivity on the optoelectronic properties of quantum dots langmuir monolayer

NASA Astrophysics Data System (ADS)

Al-Alwani, Ammar J.; Chumakov, A. S.; Begletsova, N. N.; Shinkarenko, O. A.; Markin, A. V.; Gorbachev, I. A.; Bratashov, D. N.; Gavrikov, M. V.; Venig, S. B.; Glukhovskoy, E. G.

2018-04-01

The formation of CdSe quantum dots (QDs) monolayers was studied by Langmuir Blodgett method. The fluorescence (PL) spectra of QD monolayers were investigated at different substrate type (glass, silicon and ITO glass) and the influence of graphene sheets layer (as a conductive surface) on the QDs properties has also been studied. The optoelectronic properties of QDs can be tuned by deposition of insulating nano-size layers of the liquid crystal between QDs and conductive substrate. The monolayer of QDs transferred on conductive surface (glass with ITO) has lowest intensity of PL spectra due to quenching effect. The PL intensity of QDs could be tuned by using various type of substrates or/and by transformed high conductive layer. Also the photooxidation processes of CdSe QDs monolayer on the solid surface can be controlled by selection of suitable substrate. The current-voltage (I–V) characteristics of QDs thin film on ITO surface was studied using scanning tunneling microscope (STM).

Novel geometry for simultaneous resistive, Hall and optical measurement of MgHx thin films

NASA Astrophysics Data System (ADS)

Koon, D. W.; Griffin, C. C. W.; Ares, J. R.; Leardini, F.; Sanchez, C.

2009-03-01

We describe a novel specimen geometry we have used to simultaneously probe optical transmission, sheet resistance and sheet Hall resistance in 100nm Mg films during hydrogen absorption. A Mg-film cloverleaf overlaps four rectangular Pd pads at the corners of a glass slide, a variation on a two-pad geometry used by Ingason and Olafsson for resistive studies of Pd-capped MgHx films [J. Alloys and Compounds 404- 406 (2005), 469-72.]. Hydrogen diffuses laterally through the Pd pads before entering the magnesium layer from below. The sample holder also includes an LED-photodiode pair for measuring [monochromatic] optical transmission. We show that the simultaneous measurement of these three quantities during the metal-to-insulator transition in a hydriding MgHx film allows for a more complete understanding of the hydriding process in these films.

Active microchannel fluid processing unit and method of making

DOEpatents

Bennett, Wendy D [Kennewick, WA; Martin, Peter M [Kennewick, WA; Matson, Dean W [Kennewick, WA; Roberts, Gary L [West Richland, WA; Stewart, Donald C [Richland, WA; Tonkovich, Annalee Y [Pasco, WA; Zilka, Jennifer L [Pasco, WA; Schmitt, Stephen C [Dublin, OH; Werner, Timothy M [Columbus, OH

2001-01-01

The present invention is an active microchannel fluid processing unit and method of making, both relying on having (a) at least one inner thin sheet; (b) at least one outer thin sheet; (c) defining at least one first sub-assembly for performing at least one first unit operation by stacking a first of the at least one inner thin sheet in alternating contact with a first of the at least one outer thin sheet into a first stack and placing an end block on the at least one inner thin sheet, the at least one first sub-assembly having at least a first inlet and a first outlet; and (d) defining at least one second sub-assembly for performing at least one second unit operation either as a second flow path within the first stack or by stacking a second of the at least one inner thin sheet in alternating contact with second of the at least one outer thin sheet as a second stack, the at least one second sub-assembly having at least a second inlet and a second outlet.

Active microchannel fluid processing unit and method of making

DOEpatents

Bennett, Wendy D [Kennewick, WA; Martin, Peter M [Kennewick, WA; Matson, Dean W [Kennewick, WA; Roberts, Gary L [West Richland, WA; Stewart, Donald C [Richland, WA; Tonkovich, Annalee Y [Pasco, WA; Zilka, Jennifer L [Pasco, WA; Schmitt, Stephen C [Dublin, OH; Werner, Timothy M [Columbus, OH

2002-12-10

The present invention is an active microchannel fluid processing unit and method of making, both relying on having (a) at least one inner thin sheet; (b) at least one outer thin sheet; (c) defining at least one first sub-assembly for performing at least one first unit operation by stacking a first of the at least one inner thin sheet in alternating contact with a first of the at least one outer thin sheet into a first stack and placing an end block on the at least one inner thin sheet, the at least one first sub-assembly having at least a first inlet and a first outlet; and (d) defining at least one second sub-assembly for performing at least one second unit operation either as a second flow path within the first stack or by stacking a second of the at least one inner thin sheet in alternating contact with second of the at least one outer thin sheet as a second stack, the at least one second sub-assembly having at least a second inlet and a second outlet.

A Novel Method for Producing Light GMT Sheets by a Pneumatic Technique

NASA Astrophysics Data System (ADS)

Dai, H.-L.; Rao, Y.-N.

2015-09-01

A novel method for producing a kind of light glass-mat- reinforced thermoplastic (GMT) sheets by using a pneumatic technique is presented. The tensile and flexural properties of produced light GMT sheets, with various lengths of glass fibers and PP content, were determined experimentally. Results of the experimental investigation show that the light GMT sheets are fully suitable for engineering applications.

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. Copyright © 2015 Elsevier B.V. All rights reserved.

Thin glass shells for AO: from plano to off-axis aspherics

NASA Astrophysics Data System (ADS)

Harel, Emmanuelle; Anretar, Alain; Antelme, Jean-Pierre; Caillon, Stéphane; Dussourd, Adrien; Foucaud, Guillaume; Jaury, Hervé; Roure, Océane; William, Jean-Philippe; Wuillaume, Philippe; Ruch, Eric; Geyl, Roland

2016-07-01

Reosc has been working on thin glass shells for many years and was recently selected by ESO for the production of the E-ELT M4 mirror thin glass shells. Previously Reosc also produced the aspheric thin shell for the VLT-M2 AO Facility. Based on this experience we will discuss how off axis thin glass shells can be made for the next generation AO systems like the GMT one.

Emittance Measurements for a Thin Liquid Sheet Flow

NASA Technical Reports Server (NTRS)

Englehart, Amy N.; McConley, Marc W.; Chubb, Donald L.

1996-01-01

The Liquid Sheet Radiator (LSR) is an external flow radiator that uses a triangular-shaped flowing liquid sheet as the radiating surface. It has potentially much lower mass than solid wall radiators such as pumped loop and heat pipe radiators, along with being nearly immune to micrometeoroid penetration. The LSR has an added advantage of simplicity. Surface tension causes a thin (100-300 microns) liquid sheet to coalesce to a point, causing the sheet flow to have a triangular shape. Such a triangular sheet is desirable since it allows for simple collection of the flow at a single point. A major problem for all external flow radiators is the requirement that the working fluid be of very low (approx. 10(sup -8) torr) vapor pressure to keep evaporative losses low. As a result, working fluids are limited to certain oils (such as used in diffusion pumps) for low temperatures (300-400 K) and liquid metals for higher temperatures. Previous research on the LSR has been directed at understanding the fluid mechanics of thin sheet flows and assessing the stability of such flows, especially with regard to the formation of holes in the sheet. Taylor studied extensively the stability of thin liquid sheets both theoretically and experimentally. He showed that thin sheets in a vacuum are stable. The latest research has been directed at determining the emittance of thin sheet flows. The emittance was calculated from spectral transmittance data for the Dow Corning 705 silicone oil. By experimentally setting up a sheet flow, the emittance was also determined as a function of measurable quantities, most importantly, the temperature drop between the top of the sheet and the temperature at the coalescence point of the sheet. Temperature fluctuations upstream of the liquid sheet were a potential problem in the analysis and were investigated.

Method for shallow junction formation

DOEpatents

Weiner, K.H.

1996-10-29

A doping sequence is disclosed that reduces the cost and complexity of forming source/drain regions in complementary metal oxide silicon (CMOS) integrated circuit technologies. The process combines the use of patterned excimer laser annealing, dopant-saturated spin-on glass, silicide contact structures and interference effects creates by thin dielectric layers to produce source and drain junctions that are ultrashallow in depth but exhibit low sheet and contact resistance. The process utilizes no photolithography and can be achieved without the use of expensive vacuum equipment. The process margins are wide, and yield loss due to contact of the ultrashallow dopants is eliminated. 8 figs.

Method for shallow junction formation

DOEpatents

Weiner, Kurt H.

1996-01-01

A doping sequence that reduces the cost and complexity of forming source/drain regions in complementary metal oxide silicon (CMOS) integrated circuit technologies. The process combines the use of patterned excimer laser annealing, dopant-saturated spin-on glass, silicide contact structures and interference effects creates by thin dielectric layers to produce source and drain junctions that are ultrashallow in depth but exhibit low sheet and contact resistance. The process utilizes no photolithography and can be achieved without the use of expensive vacuum equipment. The process margins are wide, and yield loss due to contact of the ultrashallow dopants is eliminated.

Screening of liquids for thermocapillary bubble movement

NASA Technical Reports Server (NTRS)

Wilcox, W. R.; Subramanian, R. S.; Papazian, J. M.; Smith, H. D.; Mattox, D. M.

1979-01-01

Ground-based methods for pretesting qualitatively the thermocapillary movement of gas bubbles in a liquid to be used in space processing are discussed. Theoretical considerations are shown to require the use of a thin, enclosed, horizontal liquid film in order that the bubbles move faster than the bulk convection of the liquid, with insulating boundaries to prevent the onset of instabilities. Experimental realizations of horizontal cells in which to test the thermocapillary movement of bubbles in sheets of molten glass heated from below and organic melts in tubes heated from both ends are briefly described and the results of experiments are indicated.

FDTD modeling of thin impedance sheets

NASA Technical Reports Server (NTRS)

Luebbers, Raymond J.; Kunz, Karl S.

1991-01-01

Thin sheets of resistive or dielectric material are commonly encountered in radar cross section calculations. Analysis of such sheets is simplified by using sheet impedances. In this paper it is shown that sheet impedances can be modeled easily and accurately using Finite Difference Time Domain (FDTD) methods.

Evaluations of candidate encapsulation designs and materials for low-cost silicon photovoltaic arrays

NASA Technical Reports Server (NTRS)

Gaines, G. B.; Carmichael, D. C.; Sliemers, F. A.; Brockway, M. C.; Bunk, A. R.; Nance, G. P.

1978-01-01

Three encapsulation designs for silicon photovoltaic arrays based on cells with silk-screened Ag metallization have been evaluated: transparent polymeric coatings over cells laminated between two films or sheets of polymeric materials; cells adhesively bonded to a glass cover with a polymer pottant and a glass or other substrate component. Silicone and acrylic coatings were assessed, together with acrylic sheet, 0.635 mm fiberglass-reinforced polyester sheet, 0.102 mm polycarbonate/acrylic dual-layer film, 0.127 mm fluorocarbon film, soda-lime glass, borosilicate glass, low-iron glass, and several adhesives. The encapsulation materials were characterized by light transmittance measurements, determination of moisture barrier properties and bond strengths, and by the performance of cells before and after encapsulation. Silicon and acrylic coatings provided inadequate protection. Acrylic and fluorocarbon films displayed good weatherability and acceptable optical transmittance. Borosilicate, low-iron and soda-lime-float glasses were found to be acceptable candidate encapsulants for most environments.

Two-dimensional La2/3Sr4/3MnO4 Manganite Films Probed by Epitaxial Strain and Cation Ordering

NASA Astrophysics Data System (ADS)

Nelson-Cheeseman, Brittany; Santos, Tiffany; Bhattacharya, Anand

2010-03-01

Dimensionality is known to play a central role in the properties of strongly correlated systems. Here we investigate magnetism and transport in thin films of the Ruddlesden-Popper n=1 phase, La1-xSr1+xMnO4. Within this material, the MnO6-octahedra form two-dimensional perovskite sheets separated by an extra rocksalt layer. By fabricating high quality thin films with ozone-assisted molecular beam epitaxy, we study how the effects of epitaxial strain and intentional cation ordering, known as digital synthesis, influence the properties of this 2-dimensional manganite. For example, at the same Mn^3+:Mn^4+ ratio (2:1) as its fully spin-polarized 3D manganite counterpart, this two dimensional analog at x=1/3 only displays a spin glass phase below 20K in bulk. This is believed to result from a competition between superexchange and double exchange, as well as disordered Jahn-Teller distortions. However, in our films we find weak ferromagnetic order up to much higher temperatures in addition to a low temperature spin glass phase. We will discuss how strain and cation order effect the presence of this weak ferromagnetism.

Method of manufacturing large dish reflectors for a solar concentrator apparatus

DOEpatents

Angel, Roger P [Tucson, AZ; Olbert, Blain H [Tucson, AZ

2011-12-27

A method of manufacturing monolithic glass reflectors for concentrating sunlight in a solar energy system is disclosed. The method of manufacturing allows large monolithic glass reflectors to be made from float glass in order to realize significant cost savings on the total system cost for a solar energy system. The method of manufacture includes steps of heating a sheet of float glass positioned over a concave mold until the sheet of glass sags and stretches to conform to the shape of the mold. The edges of the dish-shaped glass are rolled for structural stiffening around the periphery. The dish-shaped glass is then silvered to create a dish-shaped mirror that reflects solar radiation to a focus. The surface of the mold that contacts the float glass preferably has a grooved surface profile comprising a plurality of cusps and concave valleys. This grooved profile minimizes the contact area and marring of the specular glass surface, reduces parasitic heat transfer into the mold and increases mold lifetime. The disclosed method of manufacture is capable of high production rates sufficiently fast to accommodate the output of a conventional float glass production line so that monolithic glass reflectors can be produced as quickly as a float glass production can make sheets of float glass to be used in the process.

Influence of sputtering deposition parameters on electrical and optical properties of aluminium-doped zinc oxide thin films for photovoltaic applications

NASA Astrophysics Data System (ADS)

Krawczak, Ewelina; Agata, Zdyb; Gulkowski, Slawomir; Fave, Alain; Fourmond, Erwann

2017-11-01

Transparent Conductive Oxides (TCOs) characterized by high visible transmittance and low electrical resistivity play an important role in photovoltaic technology. Aluminum doped zinc oxide (AZO) is one of the TCOs that can find its application in thin film solar cells (CIGS or CdTe PV technology) as well as in other microelectronic applications. In this paper some optical and electrical properties of ZnO:Al thin films deposited by RF magnetron sputtering method have been investigated. AZO layers have been deposited on the soda lime glass substrates with use of variable technological parameters such as pressure in the deposition chamber, power applied and temperature during the process. The composition of AZO films has been investigated by EDS method. Thickness and refraction index of the deposited layers in dependence on certain technological parameters of sputtering process have been determined by spectroscopic ellipsometry. The measurements of transmittance and sheet resistance were also performed.

Weld Repair of Thin Aluminum Sheet

NASA Technical Reports Server (NTRS)

Beuyukian, C. S.; Mitchell, M. J.

1986-01-01

Weld repairing of thin aluminum sheets now possible, using niobium shield and copper heat sinks. Refractory niobium shield protects aluminum adjacent to hole, while copper heat sinks help conduct heat away from repair site. Technique limits tungsten/inert-gas (TIG) welding bombardment zone to melt area, leaving surrounding areas around weld unaffected. Used successfully to repair aluminum cold plates on Space Shuttle, Commercial applications, especially in sealing fractures, dents, and holes in thin aluminum face sheets or clad brazing sheet in cold plates, heat exchangers, coolers, and Solar panels. While particularly suited to thin aluminum sheet, this process also used in thicker aluminum material to prevent surface damage near weld area.

AN INTEGRAL EQUATION REPRESENTATION OF WIDE-BAND ELECTROMAGNETIC SCATTERING BY THIN SHEETS

EPA Science Inventory

An efficient, accurate numerical modeling scheme has been developed, based on the integral equation solution to compute electromagnetic (EM) responses of thin sheets over a wide frequency band. The thin-sheet approach is useful for simulating the EM response of a fracture system ...

Advanced Class of FML on the Base Al-Li Alloy 1441 with Lower Density

NASA Astrophysics Data System (ADS)

Antipov, V. V.; Senatorova, O. G.; Lukina, N. F.

Structure, composition, properties combination of specimens and components, a number of technological parameters for production of advanced FML based on high-modulus Al-Li 1441 alloy (E 79 GPa) with reduced density (d 2.6 g/m3) and optimized adhesive prepreg reinforced with high-strength high-modulus VMP glass fibres are described. Service life 1441 alloy provides the possibility of manufacture of thin sheets (up to 0.3 mm), clad and unclad. Moreover, some experience on the usage of 1441 T1, T11 sheets and shapes in Be 200 and Be 103 aircraft was accumulated. The class of FML materials based on Al-Li alloy provide an 5% improvement in weight efficiency and stiffness of skin structures as compared with those made from FML with conventional Al-Cu-Mg (2024T3 a.o.) and Al-Zn-Mg-Cu (7475T76 a.o.) alloys.

Collective epithelial cell sheet adhesion and migration on polyelectrolyte multilayers with uniform and gradients of compliance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martinez, Jessica S.; Schlenoff, Joseph B.; Keller, Thomas C.S., E-mail: tkeller@bio.fsu.edu

Polyelectrolyte multilayers (PEMUs) are tunable thin films that could serve as coatings for biomedical implants. PEMUs built layer by layer with the polyanion poly(acrylic acid) (PAA) modified with a photosensitive 4-(2-hydroxyethoxy) benzophenone (PAABp) group and the polycation poly(allylamine hydrochloride) (PAH) are mechanically tunable by UV irradiation, which forms covalent bonds between the layers and increases PEMU stiffness. PAH-terminated PEMUs (PAH-PEMUs) that were uncrosslinked, UV-crosslinked to a uniform stiffness, or UV-crosslinked with an edge mask or through a neutral density optical gradient filter to form continuous compliance gradients were used to investigate how differences in PEMU stiffness affect the adhesion andmore » migration of epithelial cell sheets from scales of the fish Poecilia sphenops (Black Molly) and Carassius auratus (Comet Goldfish). During the progressive collective cell migration, the edge cells (also known as ‘leader’ cells) in the sheets on softer uncrosslinked PEMUs and less crosslinked regions of the gradient formed more actin filaments and vinculin-containing adherens junctions and focal adhesions than formed in the sheet cells on stiffer PEMUs or glass. During sheet migration, the ratio of edge cell to internal cell (also known as ‘follower’ cells) motilities were greater on the softer PEMUs than on the stiffer PEMUs or glass, causing tension to develop across the sheet and periods of retraction, during which the edge cells lost adhesion to the substrate and regions of the sheet retracted toward the more adherent internal cell region. These retraction events were inhibited by the myosin II inhibitor Blebbistatin, which reduced the motility velocity ratios to those for sheets on the stiffer PEMUs. Blebbistatin also caused disassembly of actin filaments, reorganization of focal adhesions, increased cell spreading at the leading edge, as well as loss of edge cell-cell connections in epithelial cell sheets on all surfaces. Interestingly, cells throughout the interior region of the sheets on uncrosslinked PEMUs retained their actin and vinculin organization at adherens junctions after treatment with Blebbistatin. Like Blebbistatin, a Rho-kinase (ROCK) inhibitor, Y27632, promoted loss of cell-cell connections between edge cells, whereas a Rac1 inhibitor, NSC23766, primarily altered the lamellipodial protrusion in edge cells. Compliance gradient PAH-PEMUs promoted durotaxis of the cell sheets but not of individual keratocytes, demonstrating durotaxis, like plithotaxis, is an emergent property of cell sheet organization. - Highlights: • Fish scale cell sheets migrate on PAH-PAABp polyelectrolyte multilayers. • Sheets migrating on softer PEMUs periodically retract. • Sheets durotax on modulus gradients. • Myosin II inhibitors inhibit sheet integrity and migration.« less

Thin current sheets observation by MMS during a near-Earth's magnetotail reconnection event

NASA Astrophysics Data System (ADS)

Nakamura, R.; Varsani, A.; Nakamura, T.; Genestreti, K.; Plaschke, F.; Baumjohann, W.; Nagai, T.; Burch, J.; Cohen, I. J.; Ergun, R.; Fuselier, S. A.; Giles, B. L.; Le Contel, O.; Lindqvist, P. A.; Magnes, W.; Schwartz, S. J.; Strangeway, R. J.; Torbert, R. B.

2017-12-01

During summer 2017, the four spacecraft of the Magnetospheric Multiscale (MMS) mission traversed the nightside magnetotail current sheet at an apogee of 25 RE. They detected a number of flow reversal events suggestive of the passage of the reconnection current sheet. Due to the mission's unprecedented high-time resolution and spatial separation well below the ion scales, structure of thin current sheets is well resolved both with plasma and field measurements. In this study we examine the detailed structure of thin current sheets during a flow reversal event from tailward flow to Earthward flow, when MMS crossed the center of the current sheet . We investigate the changes in the structure of the thin current sheet relative to the X-point based on multi-point analysis. We determine the motion and strength of the current sheet from curlometer calculations comparing these with currents obtained from the particle data. The observed structures of these current sheets are also compared with simulations.

Ice-sheet thinning and acceleration at Camp Century, Greenlan

NASA Astrophysics Data System (ADS)

Colgan, W. T.

2017-12-01

Camp Century, Greenland (77.18 °N, 61.12 °W, 1900 m), is located approximately 150 km inland from the ice-sheet margin in Northwest Greenland. In-situ and remotely-sensed measurements of ice-sheet elevation at Camp Century exhibit a thinning trend between 1964 and the present. A comparison of 1966 and 2017 firn density profiles indicates that a portion of this ice-sheet thinning is attributable to increased firn compaction rate. In-situ measurements of increasing ice surface velocity over the 1977-2017 period indicate that enhanced horizontal divergence of ice flux is also contributing to ice dynamic thinning at Camp Century. This apparent ice dynamic thinning could potentially result from a migrating local flow divide or decreasing effective ice viscosity. In a shorter-term context, observations of decadal-scale ice-sheet thinning and acceleration at Camp Century highlights underappreciated transience in inland ice form and flow during the satellite era. In a longer-term context, these multi-decadal observations contrast with inferences of millennial-scale ice-sheet thickening and deceleration at Camp Century.

Compact vacuum insulation

DOEpatents

Benson, D.K.; Potter, T.F.

1992-10-27

Improved compact insulation panel is provided which is comprised of two adjacent metal sheets spaced close together with a plurality of spherical, or other discretely shaped, glass or ceramic beads optimally positioned between the sheets to provide support and maintain the spacing between the metal sheets when the gases there between are evacuated to form a vacuum. These spherical glass beads provide the maximum support while minimizing thermal conductance. In its preferred embodiment; these two metal sheets are textured with ribs or concave protrusions in conjunction with the glass beads to maximize the structural integrity of the panels while increasing the spacing between beads, thereby reducing the number of beads and the number of thermal conduction paths. Glass or porcelain-enameled liners in combination with the glass spacers and metal sidewalls effectively decrease thermal conductivity, and various laminates, including wood, porcelain-enameled metal, and others effectively increase the strength and insulation capabilities of the panels. Also, a metal web is provided to hold the spacers in place, and strategic grooves are shown to accommodate expansion and contraction or shaping of the panels. 35 figs.

Compact vacuum insulation

DOEpatents

Benson, David K.; Potter, Thomas F.

1992-01-01

Improved compact insulation panel is provided which is comprised of two adjacent metal sheets spaced close together with a plurality of spherical, or other discretely shaped, glass or ceramic beads optimally positioned between the sheets to provide support and maintain the spacing between the metal sheets when the gases therebetween are evacuated to form a vacuum. These spherical glass beads provide the maximum support while minimizing thermal conductance. In its preferred embodiment; these two metal sheets are textured with ribs or concave protrusions in conjunction with the glass beads to maximize the structural integrity of the panels while increasing the spacing between beads, thereby reducing the number of beads and the number of thermal conduction paths. Glass or porcelain-enameled liners in combination with the glass spacers and metal sidewalls effectively decrease thermal conductivity, and variious laminates, including wood, porcelain-enameled metal, and others effectively increase the strength and insulation capabilities of the panels. Also, a metal web is provided to hold the spacers in place, and strategic grooves are shown to accommodate expansion and contraction or shaping of the panels.

Microstructure of Dense Thin Sheets of gamma-TiAl Fabricated by Hot Isostatic Pressing of Tape-Cast Monotapes (Preprint)

DTIC Science & Technology

2007-02-01

fabrication of dense thin sheets of gamma titanium aluminide . Polarized light microscopy revealed a fine-grained microstructure but a few isolated...HIPed (near-gamma) microstructure occurred. 15. SUBJECT TERMS gamma titanium aluminide , thin sheet, tape casting, hot isostatic pressing 16...sheets (250–300 μm thick) of gamma titanium aluminide (γ-TiAl). Polarized light microscopy revealed a fine-grained microstructure (average grain

Fluid Dynamic and Stability Analysis of a Thin Liquid Sheet

NASA Technical Reports Server (NTRS)

McMaster, Matthew S.

1992-01-01

Interest in thin sheet flows has recently been renewed due to their potential application in space radiators. Theoretical and experimental studies of the fluid dynamics and stability of thin liquid sheet flows have been carried out in this thesis. A computer program was developed to determine the cross-sectional shape of the edge cylinder given the cross-sectional area of the edge cylinder. A stability analysis was performed on a non-planer liquid sheet. A study was conducted to determine the effects of air resistance on the sheet.

FeCoNi coated glass fibers in composite sheets for electromagnetic absorption and shielding behaviors

NASA Astrophysics Data System (ADS)

Lee, Joonsik; Jung, Byung Mun; Lee, Sang Bok; Lee, Sang Kwan; Kim, Ki Hyeon

2017-09-01

To evaluate the electromagnetic (EM) absorption and shield of magnetic composite sheet, we prepared the FeCoNi coated glass fibers filled in composite sheet. The FeCoNi was coated by electroless plating on glass fiber as a filler. The coated FeCoNi found that consist of mixtures of bcc and fcc phase. The magnetization and coercivity of coated FeCoNi are about 110 emu/g and 57 Oe, respectively. The permittivity and permeability of the FeCoNi composite sheet were about 21 and 1, respectively. Power absorption increased 95% with the increment of frequency up to 10 GHz. Inter-decoupling of this composite sheet showed maximum 30 dB at around 5.3 GHz, which is comparable to that of a conductive Cu foil. Shielding effectiveness (SE) was measured by using rectangular waveguide method. SE of composite obtained about 37 dB at X-band frequency region.

Carbon Nanotube Thin-Film Antennas.

PubMed

Puchades, Ivan; Rossi, Jamie E; Cress, Cory D; Naglich, Eric; Landi, Brian J

2016-08-17

Multiwalled carbon nanotube (MWCNT) and single-walled carbon nanotube (SWCNT) dipole antennas have been successfully designed, fabricated, and tested. Antennas of varying lengths were fabricated using flexible bulk MWCNT sheet material and evaluated to confirm the validity of a full-wave antenna design equation. The ∼20× improvement in electrical conductivity provided by chemically doped SWCNT thin films over MWCNT sheets presents an opportunity for the fabrication of thin-film antennas, leading to potentially simplified system integration and optical transparency. The resonance characteristics of a fabricated chlorosulfonic acid-doped SWCNT thin-film antenna demonstrate the feasibility of the technology and indicate that when the sheet resistance of the thin film is >40 ohm/sq no power is absorbed by the antenna and that a sheet resistance of <10 ohm/sq is needed to achieve a 10 dB return loss in the unbalanced antenna. The dependence of the return loss performance on the SWCNT sheet resistance is consistent with unbalanced metal, metal oxide, and other CNT-based thin-film antennas, and it provides a framework for which other thin-film antennas can be designed.

Dynamic Inland Propagation of Thinning Due to Ice Loss at the Margins of the Greenland Ice Sheet

NASA Technical Reports Server (NTRS)

Wang, Wei Li; Li, Jun J.; Zwally, H. Jay

2012-01-01

Mass-balance analysis of the Greenland ice sheet based on surface elevation changes observed by the European Remote-sensing Satellite (ERS) (1992-2002) and Ice, Cloud and land Elevation Satellite (ICESat) (2003-07) indicates that the strongly increased mass loss at lower elevations (<2000 m) of the ice sheet, as observed during 2003-07, appears to induce interior ice thinning at higher elevations. In this paper, we perform a perturbation experiment with a three-dimensional anisotropic ice-flow model (AIF model) to investigate this upstream propagation. Observed thinning rates in the regions below 2000m elevation are used as perturbation inputs. The model runs with perturbation for 10 years show that the extensive mass loss at the ice-sheet margins does in fact cause interior thinning on short timescales (i.e. decadal). The modeled pattern of thinning over the ice sheet agrees with the observations, which implies that the strong mass loss since the early 2000s at low elevations has had a dynamic impact on the entire ice sheet. The modeling results also suggest that even if the large mass loss at the margins stopped, the interior ice sheet would continue thinning for 300 years and would take thousands of years for full dynamic recovery.

Fabrication of a transparent conducting electrode based on graphene/silver nanowires via layer-by-layer method for organic photovoltaic devices.

PubMed

Tugba Camic, B; Oytun, Faruk; Hasan Aslan, M; Jeong Shin, Hee; Choi, Hyosung; Basarir, Fevzihan

2017-11-01

A solution-processed transparent conducting electrode was fabricated via layer-by-layer (LBL) deposition of graphene oxide (GO) and silver nanowires (Ag NWs). First, graphite was oxidized with a modified Hummer's method to obtain negatively-charged GO sheets, and Ag NWs were functionalized with cysteamine hydrochloride to acquire positively-charged silver nanowires. Oppositely-charged GO and Ag NWs were then sequentially coated on a 3-aminopropyltriethoxysilane modified glass substrate via LBL deposition, which provided highly controllable thin films in terms of optical transmittance and sheet resistance. Next, the reduction of GO sheets was performed to improve the electrical conductivity of the multilayer films. The resulting GO/Ag NWs multilayer was characterized by a UV-Vis spectrometer, field emission scanning electron microscope (FE-SEM), optical microscope (OM) and sheet resistance using a four-point probe method. The best result was achieved with a 2-bilayer film, resulting in a sheet resistance of 6.5Ω sq -1 with an optical transmittance of 78.2% at 550nm, which values are comparable to those of commercial ITO electrodes. The device based on a 2-bilayer hybrid film exhibited the highest device efficiency of 1.30% among the devices with different number of graphene/Ag NW LBL depositions. Copyright © 2017 Elsevier Inc. All rights reserved.

Laser cutting of ultra-thin glasses based on a nonlinear laser interaction effect

NASA Astrophysics Data System (ADS)

Chen, Jian; Wu, Zhouling

2013-07-01

Glass panel substrates have been widely used in consumer electronics such as in flat panel TVs, laptops, and cell phones. With the advancement in the industry, the glass substrates are becoming thinner and stronger for reduced weight and volume, which brings great challenges for traditional mechanical processes in terms of cut quality, yield, and throughput. Laser glass cutting provides a non-contact process with minimum impact and superior quality compared to the mechanical counterparts. In this paper, we presented recent progresses in advanced laser processing of ultra-thin glass substrates, especially laser-cutting of ultra-thin glasses by a high power laser through a nonlinear interaction effect. Our results indicate that this technique has great potential of application for mass production of ultra-thin glass substrates.

Investigations into the impact of various substrates and ZnO ultra thin seed layers prepared by atomic layer deposition on growth of ZnO nanowire array

PubMed Central

2012-01-01

The impact of various substrates and zinc oxide (ZnO) ultra thin seed layers prepared by atomic layer deposition on the geometric morphology of subsequent ZnO nanowire arrays (NWs) fabricated by the hydrothermal method was investigated. The investigated substrates included B-doped ZnO films, indium tin oxide films, single crystal silicon (111), and glass sheets. Scanning electron microscopy and X-ray diffraction measurements revealed that the geometry and aligment of the NWs were controlled by surface topography of the substrates and thickness of the ZnO seed layers, respectively. According to atomic force microscopy data, we suggest that the substrate, fluctuate amplitude and fluctuate frequency of roughness on ZnO seed layers have a great impact on the alignment of the resulting NWs, whereas the influence of the seed layers' texture was negligible. PMID:22759838

Final Air Toxics Standards for Clay Ceramics Manufacturing, Glass Manufacturing, and Secondary Nonferrous Metals Processing Area Sources Fact Sheet

EPA Pesticide Factsheets

This page contains a December 2007 fact sheet with information regarding the National Emissions Standards for Hazardous Air Pollutants (NESHAP) for Clay Ceramics Manufacturing, Glass Manufacturing, and Secondary Nonferrous Metals Processing Area Sources

Static and Dynamic Behavior of High Modulus Hybrid Boron/Glass/Aluminum Fiber Metal Laminates

NASA Astrophysics Data System (ADS)

Yeh, Po-Ching

2011-12-01

This dissertation presents the investigation of a newly developed hybrid fiber metal laminates (FMLs) which contains commingled boron fibers, glass fibers, and 2024-T3 aluminum sheets. Two types of hybrid boron/glass/aluminum FMLs are developed. The first, type I hybrid FMLs, contained a layer of boron fiber prepreg in between two layers of S2-glass fiber prepreg, sandwiched by two aluminum alloy 2024-T3 sheets. The second, type II hybrid FMLs, contained three layer of commingled hybrid boron/glass fiber prepreg layers, sandwiched by two aluminum alloy 2024-T3 sheets. The mechanical behavior and deformation characteristics including blunt notch strength, bearing strength and fatigue behavior of these two types of hybrid boron/glass/aluminum FMLs were investigated. Compared to traditional S2-glass fiber reinforced aluminum laminates (GLARE), the newly developed hybrid boron/glass/aluminum fiber metal laminates possess high modulus, high yielding stress, and good blunt notch properties. From the bearing test result, the hybrid boron/glass/aluminum fiber metal laminates showed outstanding bearing strength. The high fiber volume fraction of boron fibers in type II laminates lead to a higher bearing strength compared to both type I laminates and traditional GLARE. Both types of hybrid FMLs have improved fatigue crack initiation lives and excellent fatigue crack propagation resistance compared to traditional GLARE. The incorporation of the boron fibers improved the Young's modulus of the composite layer in FMLs, which in turn, improved the fatigue crack initiation life and crack propagation rates of the aluminum sheets. Moreover, a finite element model was established to predict and verify the properties of hybrid boron/glass/aluminum FMLs. The simulated results showed good agreement with the experimental results.

Thin, porous metal sheets and methods for making the same

DOEpatents

Liu, Wei; Li, Xiaohong Shari; Canfield, Nathan L.

2015-07-14

Thin, porous metal sheets and methods for forming them are presented to enable a variety of applications and devices. The thin, porous metal sheets are less than or equal to approximately 200 .mu.m thick, have a porosity between 25% and 75% by volume, and have pores with an average diameter less than or equal to approximately 2 .mu.m. The thin, porous metal sheets can be fabricated by preparing a slurry having between 10 and 50 wt % solvent and between 20 and 80 wt % powder of a metal precursor. The average particle size in the metal precursor powder should be between 100 nm and 5 .mu.m.

FDTD modeling of thin impedance sheets

NASA Technical Reports Server (NTRS)

Luebbers, Raymond; Kunz, Karl

1991-01-01

Thin sheets of resistive or dielectric material are commonly encountered in radar cross section calculations. Analysis of such sheets is simplified by using sheet impedances. It is shown that sheet impedances can be modeled easily and accurately using Finite Difference Time Domain (FDTD) methods. These sheets are characterized by a discontinuity in the tangential magnetic field on either side of the sheet but no discontinuity in tangential electric field. This continuity, or single valued behavior of the electric field, allows the sheet current to be expressed in terms of an impedance multiplying this electric field.

Glass transition memorized by the enthalpy-entropy compensation in the shear thinning of supercooled metallic liquids.

PubMed

Zhang, Meng; Liu, Lin

2018-05-03

To unravel the true nature of glass transition, broader insights into glass forming have been gained by examining the stress-driven glassy systems, where strong shear thinning, i.e., a reduced viscosity under increasing shear rate, is encountered. It is argued that arbitrarily small stress-driven shear rates would "melt" the glass and erase any memory of its thermal history. In this work, we report a glass transition memorized by the enthalpy-entropy compensation in strongly shear-thinned supercooled metallic liquids, which coincides with the thermal glass transition in both the transition temperature and the activation Gibbs free energy. Our findings provide distinctive insights into both glass forming and shear thinning, and enrich current knowledge on the ubiquitous enthalpy-entropy compensation empirical law in condensed matter physics. © 2018 IOP Publishing Ltd.

Glass transition memorized by the enthalpy-entropy compensation in the shear thinning of supercooled metallic liquids

NASA Astrophysics Data System (ADS)

Zhang, Meng; Liu, Lin

2018-06-01

To unravel the true nature of glass transition, broader insights into glass forming have been gained by examining the stress-driven glassy systems, where strong shear thinning, i.e. a reduced viscosity under increasing shear rate, is encountered. It is argued that arbitrarily small stress-driven shear rates would ‘melt’ the glass and erase any memory of its thermal history. In this work, we report a glass transition memorized by the enthalpy-entropy compensation in strongly shear-thinned supercooled metallic liquids, which coincides with the thermal glass transition in both the transition temperature and the activation Gibbs free energy. Our findings provide distinctive insights into both glass forming and shear thinning, and enrich current knowledge on the ubiquitous enthalpy-entropy compensation empirical law in condensed matter physics.

Dynamics of Radially Expanding Liquid Sheets

NASA Astrophysics Data System (ADS)

Majumdar, Nayanika; Tirumkudulu, Mahesh S.

2018-04-01

The process of atomization often involves ejecting thin liquid sheets at high speeds from a nozzle that causes the sheet to flap violently and break up into fine droplets. The flapping of the liquid sheet has long been attributed to the sheet's interaction with the surrounding gas phase. Here, we present experimental evidence to the contrary and show that the flapping is caused by the thinning of the liquid sheet as it spreads out from the nozzle exit. The measured growth rates of the waves agree remarkably well with the predictions of a recent theory that accounts for the sheet's thinning but ignores aerodynamic interactions. We anticipate these results to not only lead to more accurate predictions of the final drop-size distribution but also enable more efficient designs of atomizers.

Method for producing thin sheets of proton-sensitive CR-39 plastic track detectors

NASA Technical Reports Server (NTRS)

Kinoshita, K.

1980-01-01

Procedures for fabricating large sheets of CR-39 with uniform chemical reactivity and sensitivity and which retain a clear, smooth surface after prolonged etching were investigated. Very thin sheets for certain Spacelab applications were fabricated.

Spiraling Cracks in Thin Sheets

NASA Astrophysics Data System (ADS)

Romero, Victor; Roman, Benoit; Cerda, Enrique

2008-03-01

A wide kind of everyday-life industrial products come in a thin package that needs to be torn open by the user, and the opening is not always easy. We built a simple setup to study crack propagation in thin sheets coupled with large out-of-plane displacement : A cylindrical tool is inserted in a straight incision in a thin sheet, and is pushed against the sheet perpendicularly to that incision, eventually propagating a crack. When the blunt tool is continually pushed against the lip, we found that the crack follows a very robust spiraling path. Experiments may be interpreted in terms of ``Spira Mirabilis'' (logarithmic spiral). Starting with crack theory argument, we will show that the early behavior of the cut path follows a portion of a logathmic spiral, and that the path tends to another spiral with a different pitch as the crack adds more turns. Our crack experiment illustrates the fact that thin sheets mechanics is deeply connected to geometry, and finally spirals characteristics allow us to measure material crack properties of the thin layer used.

Light Trapping in Thin Film Silicon Solar Cells on Plastic Substrates

NASA Astrophysics Data System (ADS)

de Jong, M. M.

2013-01-01

In the search for sustainable energy sources, solar energy can fulfil a large part of the growing demand. The biggest threshold for large-scale solar energy harvesting is the solar panel price. For drastic cost reductions, roll-to-roll fabrication of thin film silicon solar cells using plastic substrates can be a solution. In this thesis, we investigate the possibilities of depositing thin film solar cells directly onto cheap plastic substrates. Micro-textured glass and sheets, which have a wide range of applications, such as in green house, lighting etc, are applied in these solar cells for light trapping. Thin silicon films can be produced by decomposing silane gas, using a plasma process. In these types of processes, the temperature of the growing surface has a large influence on the quality of the grown films. Because plastic substrates limit the maximum tolerable substrate temperature, new methods have to be developed to produce device-grade silicon layers. At low temperature, polysilanes can form in the plasma, eventually forming dust particles, which can deteriorate device performance. By studying the spatially resolved optical emission from the plasma between the electrodes, we can identify whether we have a dusty plasma. Furthermore, we found an explanation for the temperature dependence of dust formation; Monitoring the formation of polysilanes as a function of temperature using a mass-spectrometer, we observed that the polymerization rate is indeed influenced by the substrate temperature. For solar cell substrate material, our choice was polycarbonate (PC), because of its low cost, its excellent transparency and its relatively high glass transition temperature of 130-140°C. At 130°C we searched for deposition recipes for device quality silicon, using a very high frequency plasma enhanced chemical deposition process. By diluting the feedstock silane with hydrogen gas, the silicon quality can be improved for amorphous silicon (a-Si), until we reach the nanocrystalline silicon (nc-Si) regime. In the nc-Si regime, the crystalline fraction can be further controlled by changing the power input into the plasma. With these layers, a-Si thin film solar cells were fabricated, on glass and PC substrates. The adverse effect of the low temperature growth on the photoactive material is further mitigated by using thinner silicon layers, which can deliver a good current only with an adequate light trapping technique. We have simulated and experimentally tested three light trapping techniques, using embossed structures in PC substrates and random structures on glass: regular pyramid structures larger than the wavelength of light (micropyramids), regular pyramid structures comparable to the wavelength of light (nanopyramids) and random nano-textures (Asahi U-type). The use of nanostructured polycarbonate substrates results in initial conversion efficiencies of 7.4%, compared to 7.6% for cells deposited under identical conditions on Asahi U-type glass. The potential of manufacturing thin film solar cells at processing temperatures lower than 130oC is further illustrated by obtained results on texture-etched aluminium doped zinc-oxide (ZnO:Al) on glass: we achieved 6.9% for nc-Si cells using a very thin absorber layer of only 750 nm, and by combining a-Si and nc-Si cells in tandem solar cells we reached an initial conversion efficiency of 9.5%.

Development of the α-IGZO/Ag/α-IGZO Triple-Layer Structure Films for the Application of Transparent Electrode.

PubMed

Chen, Kun-Neng; Yang, Cheng-Fu; Wu, Chia-Ching; Chen, Yu-Hsin

2017-02-24

We investigated the structural, optical, and electrical properties of amorphous IGZO/silver/amorphous IGZO (α-IGZO/Ag/α-IGZO) triple-layer structures that were deposited at room temperature on Eagle XG glass and flexible polyethylene terephthalate substrates through the sputtering method. Thin Ag layers with different thicknesses were inserted between two IGZO layers to form a triple-layer structure. Ag was used because of its lower absorption and resistivity. Field emission scanning electron microscopy measurements of the triple-layer structures revealed that the thicknesses of the Ag layers ranged from 13 to 41 nm. The thickness of the Ag layer had a large effect on the electrical and optical properties of the electrodes. The optimum thickness of the Ag metal thin film could be evaluated according to the optical transmittance, electrical conductivity, and figure of merit of the electrode. This study demonstrates that the α-IGZO/Ag/α-IGZO triple-layer transparent electrode can be fabricated with low sheet resistance (4.2 Ω/□) and high optical transmittance (88.1%) at room temperature without postannealing processing on the deposited thin films.

Mechanical and optoelectric properties of post-annealed fluorine-doped tin oxide films by ultraviolet laser irradiation

NASA Astrophysics Data System (ADS)

Tseng, Shih-Feng; Hsiao, Wen-Tse; Chiang, Donyau; Huang, Kuo-Cheng; Chou, Chang-Pin

2011-06-01

The fluorine-doped tin oxide (FTO) thin film deposited on a soda-lime glass substrate was annealed by a defocus ultraviolet (UV) laser irradiation at ambient temperature. The mechanical and optoelectric properties of FTO films annealed by using the various laser processing parameters were reported. After the FTO films were subjected to laser post-annealing, the microhardness were slightly less but the reduced modulus values were larger than that of unannealed FTO films, respectively. The average optical transmittance in the visible waveband slightly increased with increasing the laser annealing energy and scan speed. Moreover, all the sheet resistance of laser annealed films was less than that of the unannealed ones. We found that the sheet resistance decrease was obviously influenced by annealing. The suitable annealing conditions could maintain the film thickness and relief the internal stress generated in the film preparation process to improve the electrical conductivity via decreasing laser energy or increasing scan speed.

Time Evolution of the Macroscopic Characteristics of a Thin Current Sheet in the Course of Its Formation in the Earth's Magnetotail

NASA Astrophysics Data System (ADS)

Domrin, V. I.; Malova, H. V.; Popov, V. Yu.

2018-04-01

A numerical model is developed that allows tracing the time evolution of a current sheet from a relatively thick current configuration with isotropic distributions of the pressure and temperature in an extremely thin current sheet, which plays a key role in geomagnetic processes. Such a configuration is observed in the Earth's magnetotail in the stage preceding a large-scale geomagnetic disturbance (substorm). Thin current sheets are reservoirs of the free energy released during geomagnetic disturbances. The time evolution of the components of the pressure tensor caused by changes in the structure of the current sheet is investigated. It is shown that the pressure tensor in the current sheet evolves in two stages. In the first stage, a current sheet with a thickness of eight to ten proton Larmor radii forms. This stage is characterized by the plasma drift toward the current sheet and the Earth and can be described in terms of the Chu-Goldberger-Low approximation. In the second stage, an extremely thin current sheet with an anisotropic plasma pressure tensor forms, due to which the system is maintained in an equilibrium state. Estimates of the characteristic time of the system evolution agree with available experimental data.

40 CFR 426.21 - Specialized definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... AND STANDARDS GLASS MANUFACTURING POINT SOURCE CATEGORY Sheet Glass Manufacturing Subcategory § 426.21.... (b) The term “cullet” shall mean any broken glass generated in the manufacturing process. ...

40 CFR 426.21 - Specialized definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... AND STANDARDS GLASS MANUFACTURING POINT SOURCE CATEGORY Sheet Glass Manufacturing Subcategory § 426.21.... (b) The term “cullet” shall mean any broken glass generated in the manufacturing process. ...

Thin sheets achieve optimal wrapping of liquids

NASA Astrophysics Data System (ADS)

Paulsen, Joseph; Démery, Vincent; Davidovitch, Benny; Santangelo, Christian; Russell, Thomas; Menon, Narayanan

2015-03-01

A liquid drop can wrap itself in a sheet using capillary forces [Py et al., PRL 98, 2007]. However, the efficiency of ``capillary origami'' at covering the surface of a drop is hampered by the mechanical cost of bending the sheet. Thinner sheets deform more readily by forming small-scale wrinkles and stress-focussing patterns, but it is unclear how coverage efficiency competes with mechanical cost as thickness is decreased, and what wrapping shapes will emerge. We place a thin (~ 100 nm) polymer film on a drop whose volume is gradually decreased so that the sheet covers an increasing fraction of its surface. The sheet exhibits a complex sequence of axisymmetric and polygonal partially- and fully- wrapped shapes. Remarkably, the progression appears independent of mechanical properties. The gross shape, which neglects small-scale features, is correctly predicted by a simple geometric approach wherein the exposed area is minimized. Thus, simply using a thin enough sheet results in maximal coverage.

Preparation of Aluminum Nanomesh Thin Films from an Anodic Aluminum Oxide Template as Transparent Conductive Electrodes

NASA Astrophysics Data System (ADS)

Li, Yiwen; Chen, Yulong; Qiu, Mingxia; Yu, Hongyu; Zhang, Xinhai; Sun, Xiao Wei; Chen, Rui

2016-02-01

We have employed anodic aluminum oxide as a template to prepare ultrathin, transparent, and conducting Al films with a unique nanomesh structure for transparent conductive electrodes. The anodic aluminum oxide template is obtained through direct anodization of a sputtered Al layer on a glass substrate, and subsequent wet etching creates the nanomesh metallic film. The optical and conductive properties are greatly influenced by experimental conditions. By tuning the anodizing time, transparent electrodes with appropriate optical transmittance and sheet resistance have been obtained. The results demonstrate that our proposed strategy can serve as a potential method to fabricate low-cost TCEs to replace conventional indium tin oxide materials.

Dye-assisted dispersion of single-walled carbon nanotubes for solution fabrication of NO2 sensors

NASA Astrophysics Data System (ADS)

Ramli, M. M.; Zhang, W.; Silva, S. R. P.; Henley, S. J.

2012-09-01

Direct golden orange dye molecules were used as a dispersing agent to produce suspensions of single-walled carbon nanotubes (SWCNTs) in water. Uniform, thin film networks were fabricated by vacuum filtration using different concentrations of SWCNT and transferred subsequently to glass substrates. The dispersion efficiency was compared to other surfactants. Measurement of the sheet resistance as a function of SWCNT concentration showed a transition from 2D percolation to 3D conduction behaviour when the concentration of SWCNTs exceeded 0.001 mg/mL. The electrical response to NO2 gas exposure was investigated as a function of temperature and an optimum response was observed at 200°C.

Preparation of Aluminum Nanomesh Thin Films from an Anodic Aluminum Oxide Template as Transparent Conductive Electrodes

PubMed Central

Li, Yiwen; Chen, Yulong; Qiu, Mingxia; Yu, Hongyu; Zhang, Xinhai; Sun, Xiao Wei; Chen, Rui

2016-01-01

We have employed anodic aluminum oxide as a template to prepare ultrathin, transparent, and conducting Al films with a unique nanomesh structure for transparent conductive electrodes. The anodic aluminum oxide template is obtained through direct anodization of a sputtered Al layer on a glass substrate, and subsequent wet etching creates the nanomesh metallic film. The optical and conductive properties are greatly influenced by experimental conditions. By tuning the anodizing time, transparent electrodes with appropriate optical transmittance and sheet resistance have been obtained. The results demonstrate that our proposed strategy can serve as a potential method to fabricate low-cost TCEs to replace conventional indium tin oxide materials. PMID:26831759

Preparation of Aluminum Nanomesh Thin Films from an Anodic Aluminum Oxide Template as Transparent Conductive Electrodes.

PubMed

Li, Yiwen; Chen, Yulong; Qiu, Mingxia; Yu, Hongyu; Zhang, Xinhai; Sun, Xiao Wei; Chen, Rui

2016-02-02

We have employed anodic aluminum oxide as a template to prepare ultrathin, transparent, and conducting Al films with a unique nanomesh structure for transparent conductive electrodes. The anodic aluminum oxide template is obtained through direct anodization of a sputtered Al layer on a glass substrate, and subsequent wet etching creates the nanomesh metallic film. The optical and conductive properties are greatly influenced by experimental conditions. By tuning the anodizing time, transparent electrodes with appropriate optical transmittance and sheet resistance have been obtained. The results demonstrate that our proposed strategy can serve as a potential method to fabricate low-cost TCEs to replace conventional indium tin oxide materials.

Electrostatic bonding of thin (cycle sine 3 mil) 7070 cover glass to Ta2O5 AR-coated thin (cycle sine 2 mil) silicon wafers and solar cells

NASA Technical Reports Server (NTRS)

Egelkrout, D. W.

1981-01-01

Electrostatic bonding of thin cover glass to thin solar cells was researched. Silicon solar cells, wafers, and Corning 7070 glass of from about 0.002" to about 0.003" in thickness were used in the investigation to establish optimum parameters for producing mechanically acceptable bonds while minimizing thermal stresses and resultant solar cell electrical parameter degradation.

A stable planar bilayer membrane of phospholipid supported by cellulose sheets.

PubMed

Setaka, M; Yamamoto, T; Sato, N; Yano, M; Kwan, T

1982-01-01

A new method is reported for preparing a thin planar membrane of 1,2-distearoylsn-glycero-3-phosphocholine and egg yolk lecithin-cholesterol (molar ratio of 1:1) between a pair of cellulose sheets. This technique, developed from the method of the multilayer planar membrane preparation (Setaka, M., et al. (1979) J. Biochem. 86, 355-362; 1619-1622; (1980) J. Biochem. 88, 1819-1829), consisted of three experimental processes. First, a phospholipid monolayer was prepared at an air-water interface, then taken up on a stretched cellulose sheet. A thin lipid membrane, supported from both sides by cellulose sheets, was constructed by combining two of these lipid monolayer-cellulose sheets. The permeability coefficient of the thin lipid membrane was estimated by removing the effect of two outer cellulose sheets, and this permeability was found to be larger than those of other model membranes of a lipid bilayer, indicating that the present lipid membrane is not a perfect single lipid bilayer. However, certain experimental evidence suggests that the bulk of the phospholipids formed a bilayer between the two cellulose sheets. Since this lipid membrane is particularily stable, larger membranes can be prepared by the present method than other planar bilayer membranes of lipid, which are usually constructed inside a pin hole in a thin teflon sheet.

Structured plasma sheet thinning observed by Galileo and 1984-129

NASA Technical Reports Server (NTRS)

Reeves, G. D.; Belian, R. D.; Fritz, T. A.; Kivelson, M. G.; Mcentire, R. W.; Roelof, E. C.; Wilken, B.; Williams, D. J.

1993-01-01

On December 8, 1990, the Galileo spacecraft used the Earth for a gravity assist on its way to Jupiter. Its trajectory was such that it crossed geosynchronous orbit at approximately local midnight between 1900 and 2000 UT. At the same time, spacecraft 1984-129 was also located at geosynchronous orbit near local midnight. Several flux dropout events were observed when the two spacecraft were in the near-Earth plasma sheet in the same local time sector. Flux dropout events are associated with plasma sheet thinning in the near-profile of the near-Earth plasma sheet while 1984-129 provided an azimuthal profile. With measurements from these two spacecraft we can distinguish between spatial structures and temporal change. Our observations confirm that the geosynchronous flux dropout events are consistent with plasma sheet thinning which changes the spacecraft's magnetic connection from the trapping region to the more distant plasma sheet. However, for this period, thinning occurred on two spatial and temporal scales. The geosynchronous dropouts were highly localized phenomena of 30 min duration superimposed on a more global reconfiguration of the tail lasting approximately 4 hours.

Electronic hybridisation implications for the damage-tolerance of thin film metallic glasses

PubMed Central

Schnabel, Volker; Jaya, B. Nagamani; Köhler, Mathias; Music, Denis; Kirchlechner, Christoph; Dehm, Gerhard; Raabe, Dierk; Schneider, Jochen M.

2016-01-01

A paramount challenge in materials science is to design damage-tolerant glasses. Poisson’s ratio is commonly used as a criterion to gauge the brittle-ductile transition in glasses. However, our data, as well as results in the literature, are in conflict with the concept of Poisson’s ratio serving as a universal parameter for fracture energy. Here, we identify the electronic structure fingerprint associated with damage tolerance in thin film metallic glasses. Our correlative theoretical and experimental data reveal that the fraction of bonds stemming from hybridised states compared to the overall bonding can be associated with damage tolerance in thin film metallic glasses. PMID:27819318

Electronic hybridisation implications for the damage-tolerance of thin film metallic glasses.

PubMed

Schnabel, Volker; Jaya, B Nagamani; Köhler, Mathias; Music, Denis; Kirchlechner, Christoph; Dehm, Gerhard; Raabe, Dierk; Schneider, Jochen M

2016-11-07

A paramount challenge in materials science is to design damage-tolerant glasses. Poisson's ratio is commonly used as a criterion to gauge the brittle-ductile transition in glasses. However, our data, as well as results in the literature, are in conflict with the concept of Poisson's ratio serving as a universal parameter for fracture energy. Here, we identify the electronic structure fingerprint associated with damage tolerance in thin film metallic glasses. Our correlative theoretical and experimental data reveal that the fraction of bonds stemming from hybridised states compared to the overall bonding can be associated with damage tolerance in thin film metallic glasses.

Nanocomposite Nd-Y-Fe-B-Mo bulk magnets prepared by injection casting technique

NASA Astrophysics Data System (ADS)

Tao, Shan; Ahmad, Zubair; Zhang, Pengyue; Yan, Mi; Zheng, Xiaomei

2017-09-01

The phase composition, magnetic and microstructural properties of Nd2Fe14B/(α-Fe, Fe3B) nanocomposite magnets produced by injection casting technique have been studied. Magnetic hysteresis loop of the Nd7Y6Fe61B22Mo4 permanent magnet demonstrates the coercivity as high as 1289 kA/m. Electron microscopy elucidates a microstructure composed of magnetically soft α-Fe, Fe3B and hard Nd2Fe14B/Y2Fe14B nanograins (20-50 nm) separated by ultra-thin grain boundary layer. The Henkel plot curve of the Nd7Y6Fe61B22Mo4 magnet yields the existence of exchange coupling interactions between soft and hard phases. Macroscopically large size sheet magnet is obtained due to high glass forming ability of the Nd7Y6Fe61B22Mo4 alloy derived from large atomic radius mismatch and negative enthalpy of alloy constituent elements. The high coercivity of the magnet is attributed to the magnetically hard phase increment, nucleation of reverse domains and the presence of thin grain boundary phase. Good magnetic properties such as remanence of 0.51 T, coercivity of 1289 kA/m and maximum energy product of 46.2 kJ/m3 are obtained in directly casted Nd7Y6Fe61B22Mo4 sheet magnets.

Optical and morphological characterizations of pyronin dye-poly (vinyl alcohol) thin films formed on glass substrates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meral, Kadem, E-mail: kademm@atauni.edu.tr; Arik, Mustafa, E-mail: marik@tatauni.edu.tr; Onganer, Yavuz, E-mail: yonganer@atauni.edu.tr

Thin films of pyronin dye mixed with poly(vinyl alcohol) (PVA) on glass substrate were prepared by using spin-coating technique. The optical and morphological properties of the thin films were studied by UV-Vis., steady-state fluorescence spectroscopies and atomic force microscopy (AFM). The thin films on glass substrate were fabricated at various [PVA]/[dye] (P/D) ratios. Hence, the monomeric and H-aggregates thin films of pyronin dye mixed with PVA were formed as a function of the dye and PVA concentration. It was determined that while the monomeric thin films showed strong fluorescence, the formation of H-aggregates in the thin film caused to decreasingmore » the fluorescence intensity. AFM studies demonstrated that the morphology of the thin film was drastically varied with changing the optical property of the thin film such as monomeric and H-aggregates thin films.« less

Long-wave dynamics of an elastic sheet lubricated by a thin liquid film on a wetting substrate

NASA Astrophysics Data System (ADS)

Young, Y.-N.; Stone, H. A.

2017-06-01

The dynamics of an elastic sheet lubricated by a thin liquid film on a wetting solid substrate is examined using both numerical simulations of a long-wave lubrication equation and a quasistatic model. Interactions between the liquid and the wetting substrate are modeled by a disjoining pressure that gives rise to an ultrathin (precursor) film. For a fluid interface without elastic bending stiffness, a flat precursor film may be linearly unstable and evolve towards an equilibrium of a single "drop" connected to a flat ultrathin film. Similar behavior is found when the thin film is covered by an elastic sheet: The sheet deforms, rearranging the thin liquid film, and contributes regulating surface forces such as a bending resistance and/or a tensile force, which may arise from interactions between the sheet and liquid or inextensibility of the sheet. Glasner's quasistatic model [Phys. Fluids 15, 1837 (2003), 10.1063/1.1578076], developed for a liquid film, is adopted to investigate the combined effects of elastic and tensile forces in the sheet on the thin film dynamics. The equilibrium height of the drop is found to vary inversely with the bending rigidity. When the elastic sheet is inextensible (such as a lipid bilayer membrane), a compressive tensile force may occur and the equilibrium film height is dependent less on the bending rigidity and more on the excess area of the membrane. Analyses of the lubrication equation also show that the precursor film transitions monotonically to the core film for tension-dominated dynamics. In contrast, for elasticity-dominated dynamics, a spatial oscillation of film height in the contact line region is found. In addition, elasticity in the sheet causes a sliding motion of the thin film: the contact angle is rendered zero by elasticity, and the contact line moves at a finite speed.

Optical constants, dispersion energy parameters and dielectric properties of ultra-smooth nanocrystalline BiVO4 thin films prepared by rf-magnetron sputtering

NASA Astrophysics Data System (ADS)

Sarkar, S.; Das, N. S.; Chattopadhyay, K. K.

2014-07-01

BiVO4 thin films have been prepared through radio frequency (rf) magnetron sputtering of a pre-fabricated BiVO4 target on ITO coated glass (ITO-glass) substrate and bare glass substrates. BiVO4 target material was prepared through solid-state reaction method by heating Bi2O3 and V2O5 mixture at 800 °C for 8 h. The films were characterized by X-ray diffraction, UV-Vis spectroscopy, LCR meter, field emission scanning electron microscopy, transmission electron microscopy and atomic force microscopy. BiVO4 thin films deposited on the ITO-glass substrate are much smoother compared to the thin films prepared on bare glass substrate. The rms surface roughness calculated from the AFM images comes out to be 0.74 nm and 4.2 nm for the films deposited on the ITO-glass substrate and bare glass substrate for the deposition time 150 min respectively. Optical constants and energy dispersion parameters of these extra-smooth BiVO4 thin films have been investigated in detail. Dielectric properties of the BiVO4 thin films on ITO-glass substrate were also investigated. The frequency dependence of dielectric constant of the BiVO4 thin films has been measured in the frequency range from 20 Hz to 2 MHz. It was found that the dielectric constant increased from 145 to 343 at 20 Hz as the film thickness increased from 90 nm to 145 nm (deposition time increased from 60 min to 150 min). It shows higher dielectric constant compared to the literature value of BiVO4.

Rapid and cheap prototyping of a microfluidic cell sorter.

PubMed

Islam, M Z; McMullin, J N; Tsui, Y Y

2011-05-01

Development of a microfluidic device is generally based on fabrication-design-fabrication loop, as, unlike the microelectronics design, there is no rigorous simulation-based verification of the chip before fabrication. This usually results in extremely long, and hence expensive, product development cycle if micro/nano fabrication facilities are used from the beginning of the cycle. Here, we illustrate a novel approach of device prototyping that is fast, cheap, reliable, and most importantly, this technique can be adopted even if no state-of-the-art microfabrication facility is available. A water-jet machine is used to cut the desired microfluidic channels into a thin steel plate which is then used as a template to cut the channels into a thin sheet of a transparent and cheap polymer material named Surlyn® by using a Hot Knife™. The feature-inscribed Surlyn sheet is bonded in between two microscope glass slides by utilizing the techniques which has been being used in curing polymer film between dual layer automotive glasses for years. Optical fibers are inserted from the sides of chip and are bonded by UV epoxy. To study the applicability of this prototyping approach, we made a basic microfluidic sorter and tested its functionalities. Sample containing microparticles is injected into the chip. Light from a 532-nm diode laser is coupled into the optical fiber that delivers light to the interrogation region in the channel. The emitted light from the particle is collected by a photodiode (PD) placed over the detection window. The device sorts the particles into the sorted or waste outlets depending on the level of the PD signal. We used fluorescent latex beads to test the detection and sorting functionalities of the device. We found that the system could detect all the beads that passed through its geometric observation region and could sort almost all the beads it detected. Copyright © 2011 International Society for Advancement of Cytometry.

Fabrication of ATO/Graphene Multi-layered Transparent Conducting Thin Films

NASA Astrophysics Data System (ADS)

Li, Na; Chen, Fei; Shen, Qiang; Wang, Chuanbin; Zhang, Lianmeng

2013-03-01

A novel transparent conducting oxide based on the ATO/graphene multi-layered thin films has been developed to satisfy the application of transparent conductive electrode in solar cells. The ATO thin films are prepared by pulsed laser deposition method with high quality, namely the sheet resistance of 49.5 Ω/sq and average transmittance of 81.9 %. The prepared graphene sheet is well reduced and shows atomically thin, spotty distributed appearance on the top of the ATO thin films. The XRD and optical micrographs are used to confirm the successfully preparation of the ATO/graphene multi-layered thin films. The Hall measurements and UV-Vis spectrophotometer are conducted to evaluate the sheet resistance and optical transmittance of the innovative structure. It is found that graphene can improve the electrical properties of the ATO thin films with little influence on the optical transmittance.

Simulating Thin Sheets: Buckling, Wrinkling, Folding and Growth

NASA Astrophysics Data System (ADS)

Vetter, Roman; Stoop, Norbert; Wittel, Falk K.; Herrmann, Hans J.

2014-03-01

Numerical simulations of thin sheets undergoing large deformations are computationally challenging. Depending on the scenario, they may spontaneously buckle, wrinkle, fold, or crumple. Nature's thin tissues often experience significant anisotropic growth, which can act as the driving force for such instabilities. We use a recently developed finite element model to simulate the rich variety of nonlinear responses of Kirchhoff-Love sheets. The model uses subdivision surface shape functions in order to guarantee convergence of the method, and to allow a finite element description of anisotropically growing sheets in the classical Rayleigh-Ritz formalism. We illustrate the great potential in this approach by simulating the inflation of airbags, the buckling of a stretched cylinder, as well as the formation and scaling of wrinkles at free boundaries of growing sheets. Finally, we compare the folding of spatially confined sheets subject to growth and shrinking confinement to find that the two processes are equivalent.

Method for making thin polypropylene film

DOEpatents

Behymer, R.D.; Scholten, J.A.

1985-11-21

An economical method is provided for making uniform thickness polypropylene film as thin as 100 Angstroms. A solution of polypropylene dissolved in xylene is formed by mixing granular polypropylene and xylene together in a flask at an elevated temperature. A substrate, such as a glass plate or microscope slide is immersed in the solution. When the glass plate is withdrawn from the solution at a uniform rate, a thin polypropylene film forms on a flat surface area of the glass plate as the result of xylene evaporation. The actual thickness of the polypropylene film is functional of the polypropylene in xylene solution concentration, and the particular withdrawal rate of the glass plate from the solution. After formation, the thin polypropylene film is floated from the glass plate onto the surface of water, from which it is picked up with a wire hoop.

A Rapid Method for Deposition of Sn-Doped GaN Thin Films on Glass and Polyethylene Terephthalate Substrates

NASA Astrophysics Data System (ADS)

Pat, Suat; Özen, Soner; Korkmaz, Şadan

2018-01-01

We report the influence of Sn doping on microstructure, surface, and optical properties of GaN thin films deposited on glass and polyethylene terephthalate (PET) substrate. Sn-doped GaN thin films have been deposited by thermionic vacuum arc (TVA) at low temperature. TVA is a rapid deposition technology for thin film growth. Surface and optical properties of the thin films were presented. Grain size, height distribution, roughness values were determined. Grain sizes were calculated as 20 nm and 13 nm for glass and PET substrates, respectively. Nano crystalline forms were shown by field emission scanning electron microscopy. Optical band gap values were determined by optical methods and photoluminescence measurement. The optical band gap values of Sn doped GaN on glass and PET were determined to be approximately ˜3.40 eV and ˜3.47 eV, respectively. As a result, TVA is a rapid and low temperature deposition technology for the Sn doped GaN deposited on glass and PET substrate.

Flexible Ceramic-Metal Insulation Composite and Method of Making

NASA Technical Reports Server (NTRS)

Rasky, Daniel J. (Inventor); Sawko, Paul M. (Inventor); Kilodziej, Paul (Inventor); Kourtides, Demetrius A. (Inventor)

1998-01-01

A method for joining a woven flexible ceramic fabric and a thin metal sheet creating an integral metal surfaced flexible thermal protection article, which methods compress: placing multiple dots of high temperature metallic or fabric and the thin metal sheet in a random or organized pattern, with the proviso that the brazing material covers about 10% or less of the surface of one flat side of the metal sheet; heating the flexible ceramic fabric, brazing material and thin metal sheet for a predetermined period of time to integrally connect the same; and cooling the formed flexible article to ambient temperature. Preferably the flexible ceramic is selected from fibers comprising atoms of silicon, carbon, nitrogen, boron, oxygen or combinations thereof. The flexible thermal protection article produced is also part of the present invention. The thin metal sheet is comprised of titanium, aluminum, chromium, niobium or alloys or combinations thereof. The brazing material is selected from copper/silver or copper/gold or is a ceramic brazing or adhesive material.

Investigations on the structural, morphological, optical and electrical properties of undoped and nanosized Zn-doped CdS thin films prepared by a simplified spray technique

NASA Astrophysics Data System (ADS)

Anbarasi, M.; Nagarethinam, V. S.; Balu, A. R.

2014-12-01

CdS and Zn-doped CdS (CdS:Zn) thin films have been deposited on glass substrates by spray pyrolysis technique using a perfume atomizer. The influence of Zn incorporation on the structural, morphological, optical and electrical properties of the films has been studied. All the films exhibit hexagonal phase with (0 0 2) as preferential orientation. A shift of the (0 0 2) diffraction peak towards higher diffraction angle is observed with increased Zn doping. The optical studies confirmed that the transparency increases as Zn doping level increases and the film coated with 2 at.% Zn doping has the maximum transmittance of about 90 %. The sheet resistance (R sh ) decreases as the Zn-doping level increases and a minimum value of 1.113 × 103 Ω/sq is obtained for the film coated with 8 at.% Zn dopant. The CdS film coated with 8 at.% Zn dopant has the best structural, morphological and electrical properties.

Combining light-harvesting with detachability in high-efficiency thin-film silicon solar cells.

PubMed

Ram, Sanjay K; Desta, Derese; Rizzoli, Rita; Bellettato, Michele; Lyckegaard, Folmer; Jensen, Pia B; Jeppesen, Bjarke R; Chevallier, Jacques; Summonte, Caterina; Larsen, Arne Nylandsted; Balling, Peter

2017-06-01

Efforts to realize thin-film solar cells on unconventional substrates face several obstacles in achieving good energy-conversion efficiency and integrating light-management into the solar cell design. In this report a technique to circumvent these obstacles is presented: transferability and an efficient light-harvesting scheme are combined for thin-film silicon solar cells by the incorporation of a NaCl layer. Amorphous silicon solar cells in p-i-n configuration are fabricated on reusable glass substrates coated with an interlayer of NaCl. Subsequently, the solar cells are detached from the substrate by dissolution of the sacrificial NaCl layer in water and then transferred onto a plastic sheet, with a resultant post-transfer efficiency of 9%. The light-trapping effect of the surface nanotextures originating from the NaCl layer on the overlying solar cell is studied theoretically and experimentally. The enhanced light absorption in the solar cells on NaCl-coated substrates leads to significant improvement in the photocurrent and energy-conversion efficiency in solar cells with both 350 and 100 nm thick absorber layers, compared to flat-substrate solar cells. Efficient transferable thin-film solar cells hold a vast potential for widespread deployment of off-grid photovoltaics and cost reduction.

40 CFR 426.70 - Applicability; description of the automotive glass laminating subcategory.

Code of Federal Regulations, 2014 CFR

2014-07-01

... resulting from the processes which laminate a plastic sheet between two layers of glass, and which prepare the glass for lamination such as cutting, bending and washing, to produce automobile windshields. ...

40 CFR 426.70 - Applicability; description of the automotive glass laminating subcategory.

Code of Federal Regulations, 2012 CFR

2012-07-01

... resulting from the processes which laminate a plastic sheet between two layers of glass, and which prepare the glass for lamination such as cutting, bending and washing, to produce automobile windshields. ...

40 CFR 426.70 - Applicability; description of the automotive glass laminating subcategory.

Code of Federal Regulations, 2013 CFR

2013-07-01

... resulting from the processes which laminate a plastic sheet between two layers of glass, and which prepare the glass for lamination such as cutting, bending and washing, to produce automobile windshields. ...

Convection Constraints and Current Sheet Thinning During the Substorm Growth Phase

NASA Astrophysics Data System (ADS)

Otto, A.; Hsieh, M.

2012-12-01

A typical property during the growth phase of geomagnetic substorms is the thinning of the near-Earth current sheet, most pronounced in the region between 6 and 15 RE. We propose that the cause for this current sheet thinning is convection from the midnight tail region to the dayside to replenish magnetospheric magnetic flux that is eroded at the dayside as a result of dayside reconnection. Slow (adiabatic) convection from the near-Earth tail region toward the dayside must conserve the entropy on magnetic field lines. This constraint prohibits a source of magnetic flux from a region further out in the magnetotail. Thus the near-Earth tail region is increasingly depleted of magnetic flux (the Erickson and Wolf [1980] problem) with entropy matching that of flux tubes that are eroded on the dayside. It is proposed that the magnetic flux depletion in the near-Earth tail forces the formation of thin current layers. The process is illustrated and examined by three-dimensional meso-scale MHD simulations. It is shown that the simulations yield a time scale, location, and other general characteristics of the current sheet evolution consistent with observations during the substorm growth phase. The developing thin current sheet is easily destabilized and can undergo localized reconnection events. We present properties of the thinning current sheet, the associated entropy evolution, examples of localized reconnection onset and we discuss the dependence of this process on external parameters such the global reconnection rate.

Greenland Ice Sheet: High-Elevation Balance and Peripheral Thinning.

PubMed

Krabill; Abdalati; Frederick; Manizade; Martin; Sonntag; Swift; Thomas; Wright; Yungel

2000-07-21

Aircraft laser-altimeter surveys over northern Greenland in 1994 and 1999 have been coupled with previously reported data from southern Greenland to analyze the recent mass-balance of the Greenland Ice Sheet. Above 2000 meters elevation, the ice sheet is in balance on average but has some regions of local thickening or thinning. Thinning predominates at lower elevations, with rates exceeding 1 meter per year close to the coast. Interpolation of our results between flight lines indicates a net loss of about 51 cubic kilometers of ice per year from the entire ice sheet, sufficient to raise sea level by 0.13 millimeter per year-approximately 7% of the observed rise.

Recent Ice Sheet and Glacier Elevation Changes in Greenland from Aircraft Laser Altimetry

NASA Technical Reports Server (NTRS)

Krabill, William B.; Thomas, R.; Sonntag, J.; Manizade, S.; Yungel, J.

2008-01-01

The Arctic Ice Mapping group (Project AIM) at the NASA Goddard Space Flight Center Wallops Flight Facility has been conducting systematic topographic surveys of the Greenland Ice Sheet (GIS) since 1993, using scanning airborne laser altimeters combined with Global Positioning System (UPS) technology. Earlier surveys showed the ice sheet above 2000-rn elevation to be in balance, but with localized regions of thickening or thinning. Thinning predominates at lower elevations and thinning rates have recently increased, resulting in a negative mass balance for the entire ice sheet. Recently, critical segments of near-coastal flight lines in Greenland were resurveyed. Results from the new data will be presented.

Development of the α-IGZO/Ag/α-IGZO Triple-Layer Structure Films for the Application of Transparent Electrode

PubMed Central

Chen, Kun-Neng; Yang, Cheng-Fu; Wu, Chia-Ching; Chen, Yu-Hsin

2017-01-01

We investigated the structural, optical, and electrical properties of amorphous IGZO/silver/amorphous IGZO (α-IGZO/Ag/α-IGZO) triple-layer structures that were deposited at room temperature on Eagle XG glass and flexible polyethylene terephthalate substrates through the sputtering method. Thin Ag layers with different thicknesses were inserted between two IGZO layers to form a triple-layer structure. Ag was used because of its lower absorption and resistivity. Field emission scanning electron microscopy measurements of the triple-layer structures revealed that the thicknesses of the Ag layers ranged from 13 to 41 nm. The thickness of the Ag layer had a large effect on the electrical and optical properties of the electrodes. The optimum thickness of the Ag metal thin film could be evaluated according to the optical transmittance, electrical conductivity, and figure of merit of the electrode. This study demonstrates that the α-IGZO/Ag/α-IGZO triple-layer transparent electrode can be fabricated with low sheet resistance (4.2 Ω/□) and high optical transmittance (88.1%) at room temperature without postannealing processing on the deposited thin films. PMID:28772586

Extensive dynamic thinning on the margins of the Greenland and Antarctic ice sheets.

PubMed

Pritchard, Hamish D; Arthern, Robert J; Vaughan, David G; Edwards, Laura A

2009-10-15

Many glaciers along the margins of the Greenland and Antarctic ice sheets are accelerating and, for this reason, contribute increasingly to global sea-level rise. Globally, ice losses contribute approximately 1.8 mm yr(-1) (ref. 8), but this could increase if the retreat of ice shelves and tidewater glaciers further enhances the loss of grounded ice or initiates the large-scale collapse of vulnerable parts of the ice sheets. Ice loss as a result of accelerated flow, known as dynamic thinning, is so poorly understood that its potential contribution to sea level over the twenty-first century remains unpredictable. Thinning on the ice-sheet scale has been monitored by using repeat satellite altimetry observations to track small changes in surface elevation, but previous sensors could not resolve most fast-flowing coastal glaciers. Here we report the use of high-resolution ICESat (Ice, Cloud and land Elevation Satellite) laser altimetry to map change along the entire grounded margins of the Greenland and Antarctic ice sheets. To isolate the dynamic signal, we compare rates of elevation change from both fast-flowing and slow-flowing ice with those expected from surface mass-balance fluctuations. We find that dynamic thinning of glaciers now reaches all latitudes in Greenland, has intensified on key Antarctic grounding lines, has endured for decades after ice-shelf collapse, penetrates far into the interior of each ice sheet and is spreading as ice shelves thin by ocean-driven melt. In Greenland, glaciers flowing faster than 100 m yr(-1) thinned at an average rate of 0.84 m yr(-1), and in the Amundsen Sea embayment of Antarctica, thinning exceeded 9.0 m yr(-1) for some glaciers. Our results show that the most profound changes in the ice sheets currently result from glacier dynamics at ocean margins.

Using sputter coated glass to stabilize microstrip gas chambers

DOEpatents

Gong, Wen G.

1997-01-01

By sputter coating a thin-layer of low-resistive, electronically-conductive glass on various substrates (including quartz and ceramics, thin-film Pestov glass), microstrip gas chambers (MSGC) of high gain stability, low leakage current, and a high rate capability can be fabricated. This design can make the choice of substrate less important, save the cost of ion-implantation, and use less glass material.

Metal nanoparticle-graphene oxide composites: Photophysical properties and sensing applications

NASA Astrophysics Data System (ADS)

Murphy, Sean J.

Composite nanomaterials allow for attractive properties of multiple functional components to be combined. Fundamental understanding of the interaction between different nanomaterials, their surroundings, and nearby molecular species is pertinent for implementation into devices. Metal nanoparticles have been used for their optical properties in many applications including stained glass, cancer therapy, solar steam generation, surface enhanced Raman spectroscopy (SERS), and catalysis. Carbon-based nanomaterials such as graphene and carbon nanotubes show potential for a wide variety of applications including solar energy harvesting, chemical sensors, and electronics. Combining useful and in some cases new properties of composite nanomaterials offers exciting opportunities in fundamental science and device development. In this dissertation, I aim to address understanding photoinduced interaction between porphyrin and silver nanoparticles, inter-sheet interaction between stacked graphene oxide (GO) sheets in thin films, complexation of reduced GO with Raman active target molecule in SERS applications, and efficacy of graphene-metal nanoparticle composites for sensing applications. Molecule-metal nanoparticle composite material made up of photoactive porphyrin and silver nanoparticles was studied using various spectroscopic tools. UV-visible absorption and surface enhanced Raman spectroscopic results suggest formation of a charge-transfer complex for porphyrin-silver nanoparticle composite. Ultrafast transient absorption and fluorescence upconversion spectroscopies further corroborate electronic interaction by providing evidence for excited state electron transfer between porphyrin and silver nanoparticles. Understanding electronic interaction between adsorbed photoactive molecules and metal nanoparticles may be of use for applications in photocatalysis or light-energy harvesting. Graphene oxide (GO) thin films have been prepared and studied using transient absorption microscopy (TAM). Transient absorption microscopy correlated with atomic force microscope allows for the morphological properties of GO thin film to be related to optical properties, namely dynamics of photoexcited carriers in GO. Results suggest short-timescale (ps -- ˜1 ns) dynamics of charge carriers in GO are affected very little by interaction with the glass substrate on which GO is placed. Also, the stack thickness or number of stacked GO sheets does not play a large role in the short-timescale dynamics of GO charge carriers. GO or reduced GO (RGO)-silver nanoparticles composites were produced using different methods: (1) chemical reduction of silver ion precursor and (2) photocatalytic reduction of GO and silver ion using TiO2 nanoparticles. Optical and morphological properties of composites were studied using spectroscopy and electron microscopy revealing a degree of control in metal nanoparticle growth and loading on the surface of RGO. Nanocomposites were shown to be capable of complexing with or adsorbing target molecular species. Complexation and adsorption are corroborated with demonstration that the composite nanomaterials act as effective SERRS sensors taking advantage of localized surface plasmon resonance of metal nanoparticles and the ability of RGO to interact with molecular and ionic species.

Transferable and flexible thin film devices for engineering applications

NASA Astrophysics Data System (ADS)

Mutyala, Madhu Santosh K.; Zhou, Jingzhou; Li, Xiaochun

2014-05-01

Thin film devices can be of significance for manufacturing, energy conversion systems, solid state electronics, wireless applications, etc. However, these thin film sensors/devices are normally fabricated on rigid silicon substrates, thus neither flexible nor transferrable for engineering applications. This paper reports an innovative approach to transfer polyimide (PI) embedded thin film devices, which were fabricated on glass, to thin metal foils. Thin film thermocouples (TFTCs) were fabricated on a thin PI film, which was spin coated and cured on a glass substrate. Another layer of PI film was then spin coated again on TFTC/PI and cured to obtain the embedded TFTCs. Assisted by oxygen plasma surface coarsening of the PI film on the glass substrate, the PI embedded TFTC was successfully transferred from the glass substrate to a flexible copper foil. To demonstrate the functionality of the flexible embedded thin film sensors, they were transferred to the sonotrode tip of an ultrasonic metal welding machine for in situ process monitoring. The dynamic temperatures near the sonotrode tip were effectively measured under various ultrasonic vibration amplitudes. This technique of transferring polymer embedded electronic devices onto metal foils yield great potentials for numerous engineering applications.

Electron Cooling and Isotropization during Magnetotail Current Sheet Thinning: Implications for Parallel Electric Fields

NASA Astrophysics Data System (ADS)

Lu, San; Artemyev, A. V.; Angelopoulos, V.

2017-11-01

Magnetotail current sheet thinning is a distinctive feature of substorm growth phase, during which magnetic energy is stored in the magnetospheric lobes. Investigation of charged particle dynamics in such thinning current sheets is believed to be important for understanding the substorm energy storage and the current sheet destabilization responsible for substorm expansion phase onset. We use Time History of Events and Macroscale Interactions during Substorms (THEMIS) B and C observations in 2008 and 2009 at 18 - 25 RE to show that during magnetotail current sheet thinning, the electron temperature decreases (cooling), and the parallel temperature decreases faster than the perpendicular temperature, leading to a decrease of the initially strong electron temperature anisotropy (isotropization). This isotropization cannot be explained by pure adiabatic cooling or by pitch angle scattering. We use test particle simulations to explore the mechanism responsible for the cooling and isotropization. We find that during the thinning, a fast decrease of a parallel electric field (directed toward the Earth) can speed up the electron parallel cooling, causing it to exceed the rate of perpendicular cooling, and thus lead to isotropization, consistent with observation. If the parallel electric field is too small or does not change fast enough, the electron parallel cooling is slower than the perpendicular cooling, so the parallel electron anisotropy grows, contrary to observation. The same isotropization can also be accomplished by an increasing parallel electric field directed toward the equatorial plane. Our study reveals the existence of a large-scale parallel electric field, which plays an important role in magnetotail particle dynamics during the current sheet thinning process.

Assembly of metallic nanoparticle arrays on glass via nanoimprinting and thin-film dewetting

PubMed Central

Lee, Sun-Kyu; Hwang, Sori; Kim, Yoon-Kee

2017-01-01

We propose a nanofabrication process to generate large-area arrays of noble metal nanoparticles on glass substrates via nanoimprinting and dewetting of metallic thin films. Glass templates were made via pattern transfer from a topographic Si mold to an inorganically cross-linked sol–gel (IGSG) resist on glass using a two-layer polydimethylsiloxane (PDMS) stamp followed by annealing, which turned the imprinted resist into pure silica. The transparent, topographic glass successfully templated the assembly of Au and Ag nanoparticle arrays via thin-film deposition and dewetting at elevated temperatures. The microstructural and mechanical characteristics that developed during the processes were discussed. The results are promising for low-cost mass fabrication of devices for several photonic applications. PMID:28546899

Assembly of metallic nanoparticle arrays on glass via nanoimprinting and thin-film dewetting.

PubMed

Lee, Sun-Kyu; Hwang, Sori; Kim, Yoon-Kee; Oh, Yong-Jun

2017-01-01

We propose a nanofabrication process to generate large-area arrays of noble metal nanoparticles on glass substrates via nanoimprinting and dewetting of metallic thin films. Glass templates were made via pattern transfer from a topographic Si mold to an inorganically cross-linked sol-gel (IGSG) resist on glass using a two-layer polydimethylsiloxane (PDMS) stamp followed by annealing, which turned the imprinted resist into pure silica. The transparent, topographic glass successfully templated the assembly of Au and Ag nanoparticle arrays via thin-film deposition and dewetting at elevated temperatures. The microstructural and mechanical characteristics that developed during the processes were discussed. The results are promising for low-cost mass fabrication of devices for several photonic applications.

Effects of electron pressure anisotropy on current sheet configuration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Artemyev, A. V., E-mail: aartemyev@igpp.ucla.edu; Angelopoulos, V.; Runov, A.

2016-09-15

Recent spacecraft observations in the Earth's magnetosphere have demonstrated that the magnetotail current sheet can be supported by currents of anisotropic electron population. Strong electron currents are responsible for the formation of very thin (intense) current sheets playing the crucial role in stability of the Earth's magnetotail. We explore the properties of such thin current sheets with hot isotropic ions and cold anisotropic electrons. Decoupling of the motions of ions and electrons results in the generation of a polarization electric field. The distribution of the corresponding scalar potential is derived from the electron pressure balance and the quasi-neutrality condition. Wemore » find that electron pressure anisotropy is partially balanced by a field-aligned component of this polarization electric field. We propose a 2D model that describes a thin current sheet supported by currents of anisotropic electrons embedded in an ion-dominated current sheet. Current density profiles in our model agree well with THEMIS observations in the Earth's magnetotail.« less

Current Sheet Thinning Associated with Dayside Reconnection

NASA Astrophysics Data System (ADS)

Hsieh, M.; Otto, A.; Ma, X.

2011-12-01

The thinning of the near-Earth current sheet during the growth phase is of critical importance to understand geomagnetic substorms and the conditions that lead to the onset of the expansion phase. We have proposed that convection from the midnight tail region to the dayside as the cause for this current sheet thinning. Adiabatic convection from the near-Earth tail region toward the dayside must conserve the entropy on magnetic field lines. This constraint prohibits a source of the magnetic flux from a region further out in the magnetotail. Thus the near-Earth tail region is increasingly depleted of magnetic flux (the Erickson and Wolf [1980] problem) with entropy matching that of flux tubes that are eroded on the dayside. The process is examined by three-dimensional MHD simulations. The properties of the current sheet thinning are determined as a function of the magnitude of convection toward the dayside and the lobe boundary conditions. It is shown that the model yields a time scale, location, and other general characteristics of the current sheet evolution consistent with observations during the substorm growth phase.

Solution-Processable transparent conducting electrodes via the self-assembly of silver nanowires for organic photovoltaic devices.

PubMed

Tugba Camic, B; Jeong Shin, Hee; Hasan Aslan, M; Basarir, Fevzihan; Choi, Hyosung

2018-02-15

Solution-processed transparent conducting electrodes (TCEs) were fabricated via the self-assembly deposition of silver nanowires (Ag NWs). Glass substrates modified with (3-aminopropyl)triethoxysilane (APTES) and (3-mercaptopropyl)trimethoxysilane (MPTES) were coated with Ag NWs for various deposition times, leading to three different Ag NWs samples (APTES-Ag NWs (PVP), MPTES-Ag NWs (PVP), and APTES-Ag NWs (COOH)). Controlling the deposition time produced Ag NWs monolayer thin films with different optical transmittance and sheet resistance. Post-annealing treatment improved their electrical conductivity. The Ag NWs films were successfully characterized using UV-Vis spectroscopy, field emission scanning electron microscopy, optical microscopy and four-point probe. Three Ag NWs films exhibited low sheet resistance of 4-19Ω/sq and high optical transmittance of 65-81% (at 550nm), which are comparable to those of commercial ITO electrode. We fabricated an organic photovoltaic device by using Ag NWs as the anode instead of ITO electrode, and optimized device with Ag NWs exhibited power conversion efficiency of 1.72%. Copyright © 2017 Elsevier Inc. All rights reserved.

Polynomial Expressions for Estimating Elastic Constants From the Resonance of Circular Plates

NASA Technical Reports Server (NTRS)

Salem, Jonathan A.; Singh, Abhishek

2005-01-01

Two approaches were taken to make convenient spread sheet calculations of elastic constants from resonance data and the tables in ASTM C1259 and E1876: polynomials were fit to the tables; and an automated spread sheet interpolation routine was generated. To compare the approaches, the resonant frequencies of circular plates made of glass, hardened maraging steel, alpha silicon carbide, silicon nitride, tungsten carbide, tape cast NiO-YSZ, and zinc selenide were measured. The elastic constants, as calculated via the polynomials and linear interpolation of the tabular data in ASTM C1259 and E1876, were found comparable for engineering purposes, with the differences typically being less than 0.5 percent. Calculation of additional v values at t/R between 0 and 0.2 would allow better curve fits. This is not necessary for common engineering purposes, however, it might benefit the testing of emerging thin structures such as fuel cell electrolytes, gas conversion membranes, and coatings when Poisson s ratio is less than 0.15 and high precision is needed.

New trends in space x-ray optics

NASA Astrophysics Data System (ADS)

Hudec, R.; Maršíková, V.; Pína, L.; Inneman, A.; Skulinová, M.

2017-11-01

The X-ray optics is a key element of various X-ray telescopes, X-ray microscopes, as well as other X-ray imaging instruments. The grazing incidence X-ray lenses represent the important class of X-ray optics. Most of grazing incidence (reflective) X-ray imaging systems used in astronomy but also in other (laboratory) applications are based on the Wolter 1 (or modified) arrangement. But there are also other designs and configurations proposed, used and considered for future applications both in space and in laboratory. The Kirkpatrick-Baez (K-B) lenses as well as various types of Lobster-Eye optics and MCP/Micropore optics serve as an example. Analogously to Wolter lenses, the X-rays are mostly reflected twice in these systems to create focal images. Various future projects in X-ray astronomy and astrophysics will require large segments with multiple thin shells or foils. The large Kirkpatrick-Baez modules, as well as the large Lobster-Eye X-ray telescope modules in Schmidt arrangement may serve as examples. All these space projects will require high quality and light segmented shells (bent or flat foils) with high X-ray reflectivity and excellent mechanical stability. The Multi Foil Optics (MFO) approach represent a promising alternative for both LE and K-B X-ray optical modules. Several types of reflecting substrates may be considered for these applications, with emphasis on thin float glass sheets and, more recently, high quality silicon wafers. This confirms the importance of non- Wolter X-ray optics designs for the future. Future large space X-ray telescopes (such as IXO) require precise and light-weight X-ray optics based on numerous thin reflecting shells. Novel approaches and advanced technologies are to be exploited and developed. In this contribution, we refer on results of tested X-ray mirror shells produced by glass thermal forming (GTF) and by shaping Si wafers. Both glass foils and Si wafers are commercially available, have excellent surface microroughness of a few 0.1 nm, and low weight (the volume density is 2.5 g cm-3 for glass and 2.3 g cm-3 for Si). Technologies are needed to be exploited; how to shape these substrates to achieve the required precise Xray optics geometries without degradations of the fine surface microroughness. Although glass and recently silicon wafers are considered to represent most promising materials for future advanced large aperture space Xray telescopes, there also exist other alternative materials worth further study such as amorphous metals and glassy carbon [1]. In order to achieve sub-arsec angular resolutions, principles of active optics have to be adopted.

Thin glass based packaging and photonic single-mode waveguide integration by ion-exchange technology on board and module level

NASA Astrophysics Data System (ADS)

Brusberg, Lars; Lang, Günter; Schröder, Henning

2011-01-01

The proposed novel packaging approach merges micro-system packaging and glass integrated optics. It provides 3D optical single-mode intra system links to bridge the gap between novel photonic integrated circuits and the glass fibers for inter system interconnects. We introduce our hybrid 3D photonic packaging approach based on thin glass substrates with planar integrated optical single-mode waveguides for fiber-to-chip and chip-to-chip links. Optical mirrors and lenses provide optical mode matching for photonic IC assemblies and optical fiber interconnects. Thin glass is commercially available in panel and wafer formats and characterizes excellent optical and high-frequency properties as reviewed in the paper. That makes it perfect for micro-system packaging. The adopted planar waveguide process based on ion-exchange technology is capable for high-volume manufacturing. This ion-exchange process and the optical propagation are described in detail for thin glass substrates. An extensive characterization of all basic circuit elements like straight and curved waveguides, couplers and crosses proves the low attenuation of the optical circuit elements.

Using Microporous Polytetrafluoroethylene Thin Sheets as a Flexible Solar Diffuser to Minimize Sunlight Glint to Cameras in Space

NASA Technical Reports Server (NTRS)

Choi, Michael K.

2016-01-01

An innovative design of using microporous PTFE thin sheets as a solar diffuser for MLI blankets or mechanical structure has been developed. It minimizes sunlight or stray-light glint to cameras when it is incident on these components in space. A microporous black PTFE thin sheet solar diffuser has been qualified for flight at NASA GSFC and installed to the TAGSAM arm MLI, OCAMS PolyCam sunshade MLI and SamCam motor riser MLI in the NASA OSIRIS-REx mission to meet the SamCam camera BRDF requirement.

Using microporous polytetrafluoroethylene thin sheets as a flexible solar diffuser to minimize sunlight glint to cameras in space

NASA Astrophysics Data System (ADS)

Choi, Michael K.

2016-09-01

An innovative design of using microporous PTFE thin sheets as a solar diffuser for MLI blankets or mechanical structure has been developed. It minimizes sunlight or stray-light glint to cameras when it is incident on these components in space. A microporous black PTFE thin sheet solar diffuser has been qualified for flight at NASA GSFC and installed to the TAGSAM arm MLI, OCAMS PolyCam sunshade MLI and SamCam motor riser MLI in the NASA OSIRIS-REx mission to meet the SamCam camera BRDF requirement.

Segmental and local dynamics of stacked thin films of poly(methyl methacrylate)

NASA Astrophysics Data System (ADS)

Hayashi, Tatsuhiko; Fukao, Koji

2014-02-01

The glass transition temperature and the dynamics of the α and β processes have been investigated using differential scanning calorimetry and dielectric relaxation spectroscopy during successive annealing processes above the glass transition temperature for stacked thin films of poly(methyl methacrylate) (PMMA) of various thicknesses. The glass transition temperature and the dynamics of the α process (segmental motion) of as-stacked PMMA thin films exhibit thin-film-like behavior, insofar as the glass transition temperature is depressed and the dynamics of the α process are faster than those of the bulk system. Annealing at high temperature causes the glass transition temperature to increase from the reduced value and causes the dynamics of the α process to become slower approaching those of the bulk. Contrary to the segmental motion, the relaxation time of the β process (local motion) of the stacked PMMA thin films is almost equal to that of the bulk PMMA and is unaffected by the annealing process. However, the relaxation strengths of both the α process and β process show a strong correlation between each other. The sum of the relaxation strengths remains almost unchanged, while the individual relaxation strengths change during the annealing process. The fragility index of the stacked PMMA thin films increases with annealing, which suggests that the glassy state of the stacked thin films changes from strong to fragile.

Scanning thin-sheet laser imaging microscopy (sTSLIM) with structured illumination and HiLo background rejection.

PubMed Central

Schröter, Tobias J.; Johnson, Shane B.; John, Kerstin; Santi, Peter A.

2011-01-01

We report replacement of one side of a static illumination, dual sided, thin-sheet laser imaging microscope (TSLIM) with an intensity modulated laser scanner in order to implement structured illumination (SI) and HiLo image demodulation techniques for background rejection. The new system is equipped with one static and one scanned light-sheet and is called a scanning thin-sheet laser imaging microscope (sTSLIM). It is an optimized version of a light-sheet fluorescent microscope that is designed to image large specimens (<15 mm in diameter). In this paper we describe the hardware and software modifications to TSLIM that allow for static and uniform light-sheet illumination with SI and HiLo image demodulation. The static light-sheet has a thickness of 3.2 µm; whereas, the scanned side has a light-sheet thickness of 4.2 µm. The scanned side images specimens with subcellular resolution (<1 µm lateral and <4 µm axial resolution) with a size up to 15 mm. SI and HiLo produce superior contrast compared to both the uniform static and scanned light-sheets. HiLo contrast was greater than SI and is faster and more robust than SI because as it produces images in two-thirds of the time and exhibits fewer intensity streaking artifacts. PMID:22254177

Structured plasma sheet thinning observed by Galileo and 1984-129

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reeves, G.D.; Belian, R.D.; Fritz, T.A.

On December 8, 1990, the Galileo spacecraft used the Earth for a gravity assist on its way to Jupiter. Its trajectory was such that is crossed geosynchronous orbit at approximately local midnight between 1900 and 2000 UT. At the same time, spacecraft 1984-129 was also located at geosynchronous orbit near local midnight. Several flux dropout events were observed when the two spacecraft were in the near-Earth plasma sheet in the same local time sector. Flux dropout events are associated with plasma sheet thinning in the near-Earth tail during the growth phase of substorms. This period is unique in that Galileomore » provided a rapid radial profile of the near-Earth plasma sheet while 1984-129 provided an azimuthal profile. With measurements from these two spacecraft the authors can distinguish between spatial structures and temporal changes. Their observations confirm that the geosynchronous flux dropout events are consistent with plasma sheet thinning which changes the spacecraft`s magnetic connection from the trapping region to the more distant plasma sheet. However, for this period, thinning occurred on two spatial and temporal scales. The geosynchronous dropouts were highly localized phenomena of 30 min duration superimposed on a more global reconfiguration of the tail lasting approximately 4 hours. 28 refs., 10 figs.« less

Relation of structure to mechanical properties of thin thoria dispersion strengthened nickel-chromium (TD-NiCr alloy sheet

NASA Technical Reports Server (NTRS)

Whittenberger, J. D.

1975-01-01

A study of the relation between structure and mechanical properties of thin TD-NiCr sheet indicated that the elevated temperature tensile, stress-rupture, and creep strength properties depend primarily on the grain aspect ratio and sheet thickness. In general, the strength properties increased with increasing grain aspect ratio and sheet thickness. Tensile testing revealed an absence of ductility at elevated temperatures. A threshold stress for creep appears to exist. Even small amounts of prior creep deformation at elevated temperatures can produce severe creep damage.

Cost-Effective TiAl based Materials

NASA Technical Reports Server (NTRS)

Moxson, V. S.; Sun, Fusheng; Draper, Susan L.; Froes, F. H.; Duz, V.

2003-01-01

Because of their inherent low ductility, TiAl-based materials are difficult to fabricate, especially thin gage titanium gamma aluminide (TiAl) sheet and foil. In this paper, an innovative powder metallurgy approach for producing cost-effective thin gage TiAl sheets (with 356 mm long and 235 mm wide, and a thickness of 0.74, 1.09, 1.55, and 2.34 mm, respectively) is presented. The microstructures and tensile properties at room and elevated temperatures of the thin gage TiAl are studied. Results show that these TiAl sheets have a relatively homogenous chemistry, uniform microstructure, and acceptable mechanical properties. This work demonstrates a cost-effective method for producing both flat products (sheet/foil) and complex chunky parts of TiAl for various advanced applications including aerospace and automotive industries.

Anti-reflection coatings on large area glass sheets

NASA Technical Reports Server (NTRS)

Pastirik, E.

1980-01-01

Antireflective coatings which may be suitable for use on the covers of photovoltaic solar modules can be easily produced by a dipping process. The coatings are applied to glass by drawing sheets of glass vertically out of dilute aqueous sodium silicate solutions at a constant speed, allowing the adherent liquid film to dry, then exposing the dried film to concentrated sulfuric acid, followed by a water rinse and dry. The process produces coatings of good optical performance (96.7 percent peak transmission at 0.540 mu M wavelength) combined with excellent stain and soil resistance, and good resistance to abrasion. The process is reproduceable and easily controlled.

Glass transition dynamics of stacked thin polymer films

NASA Astrophysics Data System (ADS)

Fukao, Koji; Terasawa, Takehide; Oda, Yuto; Nakamura, Kenji; Tahara, Daisuke

2011-10-01

The glass transition dynamics of stacked thin films of polystyrene and poly(2-chlorostyrene) were investigated using differential scanning calorimetry and dielectric relaxation spectroscopy. The glass transition temperature Tg of as-stacked thin polystyrene films has a strong depression from that of the bulk samples. However, after annealing at high temperatures above Tg, the stacked thin films exhibit glass transition at a temperature almost equal to the Tg of the bulk system. The α-process dynamics of stacked thin films of poly(2-chlorostyrene) show a time evolution from single-thin-film-like dynamics to bulk-like dynamics during the isothermal annealing process. The relaxation rate of the α process becomes smaller with increase in the annealing time. The time scale for the evolution of the α dynamics during the annealing process is very long compared with that for the reptation dynamics. At the same time, the temperature dependence of the relaxation time for the α process changes from Arrhenius-like to Vogel-Fulcher-Tammann dependence with increase of the annealing time. The fragility index increases and the distribution of the α-relaxation times becomes smaller with increase in the annealing time for isothermal annealing. The observed change in the α process is discussed with respect to the interfacial interaction between the thin layers of stacked thin polymer films.

Rapid Holocene thinning of an East Antarctic outlet glacier driven by marine ice sheet instability

PubMed Central

Jones, R. S.; Mackintosh, A. N.; Norton, K. P.; Golledge, N. R.; Fogwill, C. J.; Kubik, P. W.; Christl, M.; Greenwood, S. L.

2015-01-01

Outlet glaciers grounded on a bed that deepens inland and extends below sea level are potentially vulnerable to ‘marine ice sheet instability'. This instability, which may lead to runaway ice loss, has been simulated in models, but its consequences have not been directly observed in geological records. Here we provide new surface-exposure ages from an outlet of the East Antarctic Ice Sheet that reveal rapid glacier thinning occurred approximately 7,000 years ago, in the absence of large environmental changes. Glacier thinning persisted for more than two and a half centuries, resulting in hundreds of metres of ice loss. Numerical simulations indicate that ice surface drawdown accelerated when the otherwise steadily retreating glacier encountered a bedrock trough. Together, the geological reconstruction and numerical simulations suggest that centennial-scale glacier thinning arose from unstable grounding line retreat. Capturing these instability processes in ice sheet models is important for predicting Antarctica's future contribution to sea level change. PMID:26608558

Biocompatibility evaluation of sputtered zirconium-based thin film metallic glass-coated steels.

PubMed

Subramanian, Balasubramanian; Maruthamuthu, Sundaram; Rajan, Senthilperumal Thanka

2015-01-01

Thin film metallic glasses comprised of Zr48Cu36Al8Ag8 (at.%) of approximately 1.5 μm and 3 μm in thickness were prepared using magnetron sputtering onto medical grade 316L stainless steel. Their structural and mechanical properties, in vitro corrosion, and antimicrobial activity were analyzed. The amorphous thin film metallic glasses consisted of a single glassy phase, with an absence of any detectable peaks corresponding to crystalline phases. Elemental composition close to the target alloy was noted from EDAX analysis of the thin film. The surface morphology of the film showed a smooth surface on scanning electron microscopy and atomic force microscopy. In vitro electrochemical corrosion studies indicated that the zirconium-based metallic glass could withstand body fluid, showing superior resistance to corrosion and electrochemical stability. Interactions between the coated surface and bacteria were investigated by agar diffusion, solution suspension, and wet interfacial contact methods. The results indicated a clear zone of inhibition against the growth of microorganisms such as Escherichia coli and Staphylococcus aureus, confirming the antimicrobial activity of the thin film metallic glasses. Cytotoxicity studies using L929 fibroblast cells showed these coatings to be noncytotoxic in nature.

Biocompatibility evaluation of sputtered zirconium-based thin film metallic glass-coated steels

PubMed Central

Subramanian, Balasubramanian; Maruthamuthu, Sundaram; Rajan, Senthilperumal Thanka

2015-01-01

Thin film metallic glasses comprised of Zr48Cu36Al8Ag8 (at.%) of approximately 1.5 μm and 3 μm in thickness were prepared using magnetron sputtering onto medical grade 316L stainless steel. Their structural and mechanical properties, in vitro corrosion, and antimicrobial activity were analyzed. The amorphous thin film metallic glasses consisted of a single glassy phase, with an absence of any detectable peaks corresponding to crystalline phases. Elemental composition close to the target alloy was noted from EDAX analysis of the thin film. The surface morphology of the film showed a smooth surface on scanning electron microscopy and atomic force microscopy. In vitro electrochemical corrosion studies indicated that the zirconium-based metallic glass could withstand body fluid, showing superior resistance to corrosion and electrochemical stability. Interactions between the coated surface and bacteria were investigated by agar diffusion, solution suspension, and wet interfacial contact methods. The results indicated a clear zone of inhibition against the growth of microorganisms such as Escherichia coli and Staphylococcus aureus, confirming the antimicrobial activity of the thin film metallic glasses. Cytotoxicity studies using L929 fibroblast cells showed these coatings to be noncytotoxic in nature. PMID:26491304

Ideal glass transitions in thin films: An energy landscape perspective

NASA Astrophysics Data System (ADS)

Truskett, Thomas M.; Ganesan, Venkat

2003-07-01

We introduce a mean-field model for the potential energy landscape of a thin fluid film confined between parallel substrates. The model predicts how the number of accessible basins on the energy landscape and, consequently, the film's ideal glass transition temperature depend on bulk pressure, film thickness, and the strength of the fluid-fluid and fluid-substrate interactions. The predictions are in qualitative agreement with the experimental trends for the kinetic glass transition temperature of thin films, suggesting the utility of landscape-based approaches for studying the behavior of confined fluids.

Electromagnetic augmentation for casting of thin metal sheets

DOEpatents

Hull, J.R.

1987-10-28

Thin metal sheets are cast by magnetically levitating molten metal deposited in a model within a ferromagnetic yoke and between AC conducting coils and linearly displacing the magnetically levitated liquid metal while it is being cooled by the water-cooled walls of the mold to form a solid metal sheet. A conducting shield is electrically coupled to the molten metal sheet to provide a return path for eddy currents induced in the metal sheet by the current in the AC conducting coils. In another embodiment, a DC conducting coil is coupled to the metal sheet for providing a direct current therein which interacts with the magnetic field to levitate the moving metal sheet. Levitation of the metal sheet in both molten and solid forms reduces its contact pressure with the mold walls while maintaining sufficient engagement therebetween to permit efficient conductive cooling by the mold through which a coolant fluid may be circulated. 8 figs.

46 CFR 164.009-3 - Noncombustible materials not requiring specific approval.

Code of Federal Regulations, 2010 CFR

2010-10-01

... subpart: (a) Sheet glass, block glass, clay, ceramics, and uncoated fibers. (b) All metals, except... only sand, gravel, expanded vermiculite, expanded or vesicular slags, diatomaceous silica, perlite, or pumice. (d) Woven, knitted or needle punched glass fabric containing no additives other than lubricants...

High index glass thin film processing for photonics and photovoltaic (PV) applications

NASA Astrophysics Data System (ADS)

Ogbuu, Okechukwu Anthony

To favorably compete with fossil-fuel technology, the greatest challenge for thin film solar-cells is to improve efficiency and reduce material cost. Thickness scaling to thin film reduces material cost but affects the light absorption in the cells; therefore a concept that traps incident photons and increases its optical path length is needed to boost absorption in thin film solar cells. One approach is the integration of low symmetric gratings (LSG), using high index material, on either the front-side or backside of 30 um thin c-Si cells. In this study, Multicomponent TeO2--Bi2O 3--ZnO (TBZ) glass thin films were prepared using RF magnetron sputtering under different oxygen flow rates. The influences of oxygen flow rate on the structural and optical properties of the resulting thin films were investigated. The structural origin of the optical property variation was studied using X-ray diffraction, X-ray photoelectron spectroscopy, Raman Spectroscopy, and transmission electron microscopy. The results indicate that TBZ glass thin film is a suitable material for front side LSG material photovoltaic and photonics applications due to their amorphous nature, high refractive index (n > 2), broad band optical transparency window, low processing temperature. We developed a simple maskless method to pattern sputtered tellurite based glass thin films using unconventional agarose hydrogel mediated wet etching. Conventional wet etching process, while claiming low cost and high throughput, suffers from reproducibility and pattern fidelity issues due to the isotropic nature of wet chemical etching when applied to glasses and polymers. This method overcomes these challenges by using an agarose hydrogel stamp to mediate a conformal etching process. In our maskless method, agarose hydrogel stamps are patterned following a standard soft lithography and replica molding process from micropatterned masters and soaked in a chemical etchant. The micro-scale features on the stamp are subsequently transferred into glass and polymer thin films via conformal wet etching. High refractive index chalcogenide glass (n = 2.6) thin films with composition As20Se80 was selected for backside LSG material due to their attractive properties. We developed an optimized integration protocol for LSG integration and successfully integrated these LSG structures at the back side of both 30 microm c-Si solar cells and standalone 30 microm c-Si wafers. Optical and electrical characterization of LSG on thin c-Si cells shows that LSG structures create higher absorption enhancement and external quantum efficiency at long wavelengths.

Confined disclinations: exterior versus material constraints in developable thin elastic sheets.

PubMed

Efrati, Efi; Pocivavsek, Luka; Meza, Ruben; Lee, Ka Yee C; Witten, Thomas A

2015-02-01

We examine the shape change of a thin disk with an inserted wedge of material when it is pushed against a plane, using analytical, numerical, and experimental methods. Such sheets occur in packaging, surgery, and nanotechnology. We approximate the sheet as having vanishing strain, so that it takes a conical form in which straight generators converge to a disclination singularity. Then, its shape is that which minimizes elastic bending energy alone. Real sheets are expected to approach this limiting shape as their thickness approaches zero. The planar constraint forces a sector of the sheet to buckle into the third dimension. We find that the unbuckled sector is precisely semicircular, independent of the angle δ of the inserted wedge. We generalize the analysis to include conical as well as planar constraints and thereby establish a law of corresponding states for shallow cones of slope ε and thin wedges. In this regime, the single parameter δ/ε^{2} determines the shape. We discuss the singular limit in which the cone becomes a plane, and the unexpected slow convergence to the semicircular buckling observed in real sheets.

Confined disclinations: Exterior versus material constraints in developable thin elastic sheets

NASA Astrophysics Data System (ADS)

Efrati, Efi; Pocivavsek, Luka; Meza, Ruben; Lee, Ka Yee C.; Witten, Thomas A.

2015-02-01

We examine the shape change of a thin disk with an inserted wedge of material when it is pushed against a plane, using analytical, numerical, and experimental methods. Such sheets occur in packaging, surgery, and nanotechnology. We approximate the sheet as having vanishing strain, so that it takes a conical form in which straight generators converge to a disclination singularity. Then, its shape is that which minimizes elastic bending energy alone. Real sheets are expected to approach this limiting shape as their thickness approaches zero. The planar constraint forces a sector of the sheet to buckle into the third dimension. We find that the unbuckled sector is precisely semicircular, independent of the angle δ of the inserted wedge. We generalize the analysis to include conical as well as planar constraints and thereby establish a law of corresponding states for shallow cones of slope ɛ and thin wedges. In this regime, the single parameter δ /ɛ2 determines the shape. We discuss the singular limit in which the cone becomes a plane, and the unexpected slow convergence to the semicircular buckling observed in real sheets.

Organic Light Emitting Diodes with Opal Photonic Crystal Layer and Carbon Nanotube Anode

NASA Astrophysics Data System (ADS)

Ovalle Robles, Raquel; Del Rocio Nava, Maria; Williams, Christopher; Zhang, Mei; Fang, Shaoli; Lee, Sergey; Baughman, Ray; Zakhidov, Anvar

2007-03-01

We report electroluminescence intensity and spectral changes in light emission from organic light emitting diode (OLEDs) structures, which have thin transparent films of opal photonic crystal (PC). The anode in such PC-OLED is laminated on opal layer from free standing optically transparent multiwall carbon nanotubes (T-CNT) sheets made by dry spinning from CVD grown forests. Silica and polystyrene opal films were grown on glass substrates by vertical sedimentation in colloids in thermal baths and the particle size of opal spheres ranges from 300 nm to 450 nm. The use of T-CNTs, (coated by PEDOT-PSS to avoid shorting) as hole injector, allows to eliminate the use of vacuum deposition of metals and permits to achieve tunneling hole injection regime from CNT tips into Alq^3 emission layer

Fabrication and Characterization of Fully Transparent ZnO Thin-Film Transistors and Self-Switching Nano-Diodes

NASA Astrophysics Data System (ADS)

Sun, Y.; Ashida, K.; Sasaki, S.; Koyama, M.; Maemoto, T.; Sasa, S.; Kasai, S.; Iñiguez-de-la-Torre, I.; González, T.

2015-10-01

Fully transparent zinc oxide (ZnO) based thin-film transistors (TFTs) and a new type of rectifiers calls self-switching nano-diodes (SSDs) were fabricated on glass substrates at room temperature by using low resistivity and transparent conducting Al- doped ZnO (AZO) thin-films. The deposition conditions of AZO thin-films were optimized with pulsed laser deposition (PLD). AZO thin-films on glass substrates were characterized and the transparency of 80% and resistivity with 1.6*10-3 Ωcm were obtained of 50 nm thickness. Transparent ZnO-TFTs were fabricated on glass substrates by using AZO thin-films as electrodes. A ZnO-TFT with 2 μm long gate device exhibits a transconductance of 400 μS/mm and an ON/OFF ratio of 2.8*107. Transparent ZnO-SSDs were also fabricated by using ZnO based materials and clear diode-like characteristics were observed.

Modeling Geoelectric Fields and Geomagnetically Induced Currents Around New Zealand to Explore GIC in the South Island's Electrical Transmission Network

NASA Astrophysics Data System (ADS)

Divett, T.; Ingham, M.; Beggan, C. D.; Richardson, G. S.; Rodger, C. J.; Thomson, A. W. P.; Dalzell, M.

2017-10-01

Transformers in New Zealand's South Island electrical transmission network have been impacted by geomagnetically induced currents (GIC) during geomagnetic storms. We explore the impact of GIC on this network by developing a thin-sheet conductance (TSC) model for the region, a geoelectric field model, and a GIC network model. (The TSC is composed of a thin-sheet conductance map with underlying layered resistivity structure.) Using modeling approaches that have been successfully used in the United Kingdom and Ireland, we applied a thin-sheet model to calculate the electric field as a function of magnetic field and ground conductance. We developed a TSC model based on magnetotelluric surveys, geology, and bathymetry, modified to account for offshore sediments. Using this representation, the thin sheet model gave good agreement with measured impedance vectors. Driven by a spatially uniform magnetic field variation, the thin-sheet model results in electric fields dominated by the ocean-land boundary with effects due to the deep ocean and steep terrain. There is a strong tendency for the electric field to align northwest-southeast, irrespective of the direction of the magnetic field. Applying this electric field to a GIC network model, we show that modeled GIC are dominated by northwest-southeast transmission lines rather than east-west lines usually assumed to dominate.

Electrostatic bonding of thin (approximately 3 mil) 7070 cover glass to Ta2O5 AR-coated thin (approximately 2 mil) silicon wafers and solar cells

NASA Technical Reports Server (NTRS)

Egelkrout, D. W.; Horne, W. E.

1980-01-01

Electrostatic bonding (ESB) of thin (3 mil) Corning 7070 cover glasses to Ta2O5 AR-coated thin (2 mil) silicon wafers and solar cells is investigated. An experimental program was conducted to establish the effects of variations in pressure, voltage, temperature, time, Ta2O5 thickness, and various prebond glass treatments. Flat wafers without contact grids were used to study the basic effects for bonding to semiconductor surfaces typical of solar cells. Solar cells with three different grid patterns were used to determine additional requirements caused by the raised metallic contacts.

What Is Low Vision?

MedlinePlus

... magnifying reading glasses or loupes for seeing the computer screen , sheet music, or for sewing telescopic glasses ... for the Blind services. The Low Vision Pilot Project The American Foundation for the Blind (AFB) has ...

Scanning thin-sheet laser imaging microscopy (sTSLIM) with structured illumination and HiLo background rejection.

PubMed

Schröter, Tobias J; Johnson, Shane B; John, Kerstin; Santi, Peter A

2012-01-01

We report replacement of one side of a static illumination, dual sided, thin-sheet laser imaging microscope (TSLIM) with an intensity modulated laser scanner in order to implement structured illumination (SI) and HiLo image demodulation techniques for background rejection. The new system is equipped with one static and one scanned light-sheet and is called a scanning thin-sheet laser imaging microscope (sTSLIM). It is an optimized version of a light-sheet fluorescent microscope that is designed to image large specimens (<15 mm in diameter). In this paper we describe the hardware and software modifications to TSLIM that allow for static and uniform light-sheet illumination with SI and HiLo image demodulation. The static light-sheet has a thickness of 3.2 µm; whereas, the scanned side has a light-sheet thickness of 4.2 µm. The scanned side images specimens with subcellular resolution (<1 µm lateral and <4 µm axial resolution) with a size up to 15 mm. SI and HiLo produce superior contrast compared to both the uniform static and scanned light-sheets. HiLo contrast was greater than SI and is faster and more robust than SI because as it produces images in two-thirds of the time and exhibits fewer intensity streaking artifacts. 2011 Optical Society of America

Effects of the precursor concentration and different annealing ambients on the structural, optical, and electrical properties of nanostructured V2O5 thin films deposited by spray pyrolysis technique

NASA Astrophysics Data System (ADS)

Irani, Rowshanak; Rozati, Seyed Mohammad; Beke, Szabolcs

2018-04-01

V2O5 thin films were deposited with different precursor concentrations of 0.01, 0.05, and 0.1 M on glass substrates by spray pyrolysis technique, then the optimized films were annealed in different ambients (air, oxygen, and vacuum). The results showed that by increasing the concentration, the films grew along the (001) direction with an orthorhombic structure. Field emission scanning electron microscopy showed that nanorods were formed when depositing 0.05 molar of VCl3. We conclude that with the precursor concentration, the surface nanostructure can be well-controlled. Annealing improved the crystallinity under all ambients, but the best crystallinity was achieved in vacuum. It was revealed that the as-deposited films had the highest transmission, whereas the films annealed in air had the lowest. When annealed in air, the optical band gap decreased from 2.45 to 2.32 eV. The sheet resistance, resistivity, mobility, conductivity, and carrier concentration were measured for all the prepared V2O5 films.

Anomalous electrical conductivity of a gold thin film percolation system

NASA Astrophysics Data System (ADS)

Tao, Xiang-Ming; Ye, Gao-Xiang; Ye, Quan-Lin; Jin, Jin-Sheng; Lao, Yan-Feng; Jiao, Zheng-Kuan

2002-09-01

A gold thin film percolation system, deposited on a glass surface by the vapor deposition method, has been fabricated. By using the expansive and mobile properties of the silicone oil drop, a characteristic wedge-shaped film system with a slope of ~10-5 naturally forms during deposition. The electrical conductivity of the bandlike film, i.e., the uniform part of the wedge-shaped film with a fixed thickness, is measured with the four-probe method. It is found that the hopping and tunneling effects of the films are stronger than those of the other films. The dependence between the dc sheet resistance R0 and temperature T shows that the samples exhibit a negative coefficient dR0/dT below the temperature T*. According to our experiment, it is suggested that all the anomalous behaviors of the system should be related to the characteristic microstructure of the samples, which results from the immediate quench processes by the oil drop during deposition. The experiment indicates that the relaxation period of the microstructure of the samples may be longer than 30 min.

Growth of nanocrystalline Cu2ZnSnS4 thin films using the spray pyrolysis technique and their characterization

NASA Astrophysics Data System (ADS)

Chandel, Tarun; Halaszova, Sona; Prochazka, Michal; Hasko, Daniel; Velic, Dusan; Thakur, Vikas; Dwivedi, Shailendra Kumar; Zaman, M. Buhanuz; Rajaram, Poolla

2018-05-01

Nanocrystalline thin films of Cu2ZnSnS4 (CZTS) were grown on the glass substrates using the spray pyrolysis technique. The films were grown at a substrate temperature of 300 °C after which they were annealed at 350 °C in vacuum. X-ray diffraction (XRD) studies showed that the films crystallized in the kesterite structure. Energy dispersive analysis of X-rays (EDAX) studies showed that the films possess the desired stoichiometry i.e. the proportion of Cu:Zn:Sn:S in the CZTS solid solution is close to 2:1:1:4. Secondary Ions Mass Spectroscopy (SIMS) depth profiling confirmed the uniformity in elemental composition along the depth of the films. SEM studies showed that the films are covered with CZTS particles forming sheet like structures. AFM studies show that the size of the particles on the surface of the films is around 10-15 nm. UV-VIS-NIR transmission spectra were used to determine the optical band gap of the CZTS films which was found to be around 1.55eV.

High and highly variable cooling rates during pyroclastic eruptions on Axial Seamount, Juan de Fuca Ridge

NASA Astrophysics Data System (ADS)

Helo, Christoph; Clague, David A.; Dingwell, Donald B.; Stix, John

2013-03-01

We present a calorimetric analysis of pyroclastic glasses and glassy sheet lava flow crusts collected on Axial Seamount, Juan de Fuca Ridge, NE Pacific Ocean, at a water depth of about 1400 m. The pyroclastic glasses, subdivided into thin limu o Pele fragments and angular, blocky clasts, were retrieved from various stratigraphic horizons of volcaniclastic deposits on the upper flanks of the volcanic edifice. Each analysed pyroclastic sample consists of a single type of fragment from one individual horizon. The heat capacity (cp) was measured via differential scanning calorimetry (DSC) and analysed using relaxation geospeedometry to obtain the natural cooling rate across the glass transition. The limu o Pele samples (1 mm grain size fraction) and angular fragments (0.5 mm grain size fraction) exhibit cooling rates of 104.3 to 106.0 K s- 1 and 103.9 to 105.1 K s- 1, respectively. A coarser grain size fraction, 2 mm for limu o Pele and 1 mm for the angular clasts yields cooling rates at the order of 103.7 K s- 1. The range of cooling rates determined for the different pyroclastic deposits presumably relates to the size or intensity of the individual eruptions. The outer glassy crusts of the sheet lava flows were naturally quenched at rates between 63 K s- 1 and 103 K s- 1. By comparing our results with published data on the very slow quenching of lava flow crusts, we suggest that (1) fragmentation and cooling appear to be coupled dynamically and (2) ductile deformation upon the onset of cooling is restricted due to the rapid increase in viscosity. Lastly, we suggest that thermally buoyant plumes that may arise from rapid heat transfer efficiently separate clasts based on their capability to rise within the plume and as they subsequently settle from it.

Influences of Indium Tin Oxide Layer on the Properties of RF Magnetron-Sputtered (BaSr)TiO3 Thin Films on Indium Tin Oxide-Coated Glass Substrate

NASA Astrophysics Data System (ADS)

Kim, Tae Song; Oh, Myung Hwan; Kim, Chong Hee

1993-06-01

Nearly stoichiometric ((Ba+Sr)/Ti=1.08-1.09) and optically transparent (BaSr)TiO3 thin films were deposited on an indium tin oxide (ITO)-coated glass substrate by means of rf magnetron sputtering for their application to the insulating layer of an electroluminescent flat panel display. The influence of the ITO layer on the properties of (BaSr)TiO3 thin films deposited on the ITO-coated substrate was investigated. The ITO layer did not affect the crystallographic orientation of (BaSr)TiO3 thin film, but enhanced the grain growth. Another effect of the ITO layer on (BaSr)TiO3 thin films was the interdiffusion phenomenon, which was studied by means of secondary ion mass spectrometry (SIMS). As the substrate temperature increased, interdiffusion intensified at the interface not only between the grown film and ITO layer but also between the ITO layer and base glass substrate. The refractive index (nf) of (BaSr)TiO3 thin film deposited on a bare glass substrate was 2.138-2.286, as a function of substrate temperature.

40 CFR 426.22 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GLASS MANUFACTURING POINT SOURCE CATEGORY Sheet Glass Manufacturing Subcategory § 426.22 Effluent limitations guidelines representing the degree of...

40 CFR 426.22 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2011 CFR

2011-07-01

... AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GLASS MANUFACTURING POINT SOURCE CATEGORY Sheet Glass Manufacturing Subcategory § 426.22 Effluent limitations guidelines representing the degree of...

Pentacene Organic Thin-Film Transistors on Flexible Paper and Glass Substrates

DTIC Science & Technology

2014-02-12

FEB 2014 2. REPORT TYPE 3. DATES COVERED 00-00-2014 to 00-00-2014 4. TITLE AND SUBTITLE Pentacene organic thin - film transistors on flexible...Nanotechnology 25 (2014) 094005 (7pp) doi:10.1088/0957-4484/25/9/094005 Pentacene organic thin - film transistors on flexible paper and glass substrates Adam T...organic thin - film transistors (OTFTs) were fabricated on several types of flexible substrate: commercial photo paper, ultra-smooth specialty paper and

Effect of substrate and post-deposition annealing on nanostructure and optical properties of CdTe thin films

NASA Astrophysics Data System (ADS)

Hasani, Ebrahim; Raoufi, Davood

2018-04-01

Thermal evaporation is one of the promising methods for depositing CdTe thin films, which can obtain the thin films with the small thickness. In this work, CdTe nanoparticles have deposited on SiO2 substrates such as quartz (crystal) and glass (amorphous) at a temperature (Ts) of 150 °C under a vacuum pressure of 2 × 10‑5 mbar. The thickness of CdTe thin films prepared under vacuum pressure is 100 nm. X-ray diffraction analysis (XRD) results showed the formation of CdTe cubic phase with a strong preferential orientation of (111) crystalline plane on both substrates. The grain size (D) in this orientation obtained about 7.41 and 5.48 nm for quartz and glass respectively. Ultraviolet-visible spectroscopy (UV–vis) measurements indicated the optical band gap about 1.5 and 1.52 eV for CdTe thin films deposited on quartz and glass respectively. Furthermore, to show the effect of annealing temperature on structure and optical properties of CdTe thin films on quartz and glass substrates, the thin films have been annealed at temperatures 50 and 70 °C for one hour. The results of this work indicate that the structure’s parameters and optical properties of CdTe thin films change due to increase in annealing temperature.

Mechanism of bonding and debonding using surface activated bonding method with Si intermediate layer

NASA Astrophysics Data System (ADS)

Takeuchi, Kai; Fujino, Masahisa; Matsumoto, Yoshiie; Suga, Tadatomo

2018-04-01

Techniques of handling thin and fragile substrates in a high-temperature process are highly required for the fabrication of semiconductor devices including thin film transistors (TFTs). In our previous study, we proposed applying the surface activated bonding (SAB) method using Si intermediate layers to the bonding and debonding of glass substrates. The SAB method has successfully bonded glass substrates at room temperature, and the substrates have been debonded after heating at 450 °C, in which TFTs are fabricated on thin glass substrates for LC display devices. In this study, we conducted the bonding and debonding of Si and glass in order to understand the mechanism in the proposed process. Si substrates are also successfully bonded to glass substrates at room temperature and debonded after heating at 450 °C using the proposed bonding process. By the composition analysis of bonding interfaces, it is clarified that the absorbed water on the glass forms interfacial voids and cause the decrease in bond strength.

Improved damage tolerance of titanium by adhesive lamination

NASA Technical Reports Server (NTRS)

Johnson, W. S.

1982-01-01

Basic damage tolerance properties of Ti-6A1-4V titanium plate can be improved by laminating thin sheets of titanium with adhesives. Compact tension and center cracked tension specimens made from thick plate, thin sheet, and laminated plate (six plies of thin sheet) were tested. The fracture toughness of the laminated plate was 39 percent higher than the monolithic plate. The laminated plate's through the thickness crack growth rate was about 20 percent less than that of the monolithic plate. The damage tolerance life of the surface cracked laminate was 6 to over 15 times the life of a monolithic specimen. A simple method of predicting crack growth in a crack ply of a laminate is presented.

Mass Balance of the Greenland Ice Sheet at High Elevations.

PubMed

Thomas; Akins; Csatho; Fahnestock; Gogineni; Kim; Sonntag

2000-07-21

Comparison of ice discharge from higher elevation areas of the entire Greenland Ice Sheet with total snow accumulation gives estimates of ice thickening rates over the past few decades. On average, the region has been in balance, but with thickening of 21 centimeters per year in the southwest and thinning of 30 centimeters per year in the southeast. The north of the ice sheet shows less variability, with average thickening of 2 centimeters per year in the northeast and thinning of about 5 centimeters per year in the northwest. These results agree well with those from repeated altimeter surveys, except in the extreme south, where we find substantially higher rates of both thickening and thinning.

Effects of die quench forming on sheet thinning and 3-point bend testing of AA7075-T6

NASA Astrophysics Data System (ADS)

Kim, Samuel; Omer, Kaab; Rahmaan, Taamjeed; Butcher, Clifford; Worswick, Michael

2017-10-01

Lab-scaled AA7075 aluminum side impact beams were manufactured using the die quenching technique in which the sheet was solutionized and then quenched in-die during forming to a super saturated solid state. Sheet thinning measurements were taken at various locations throughout the length of the part and the effect of lubricant on surface scoring and material pick-up on the die was evaluated. The as-formed beams were subjected to a T6 aging treatment and then tested in three-point bending. Simulations were performed of the forming and mechanical testing experiments using the LS-DYNA finite element code. The thinning and mechanical response was predicted well.

Automated Rapid Prototyping of 3D Ceramic Parts

NASA Technical Reports Server (NTRS)

McMillin, Scott G.; Griffin, Eugene A.; Griffin, Curtis W.; Coles, Peter W. H.; Engle, James D.

2005-01-01

An automated system of manufacturing equipment produces three-dimensional (3D) ceramic parts specified by computational models of the parts. The system implements an advanced, automated version of a generic rapid-prototyping process in which the fabrication of an object having a possibly complex 3D shape includes stacking of thin sheets, the outlines of which closely approximate the horizontal cross sections of the object at their respective heights. In this process, the thin sheets are made of a ceramic precursor material, and the stack is subsequently heated to transform it into a unitary ceramic object. In addition to the computer used to generate the computational model of the part to be fabricated, the equipment used in this process includes: 1) A commercially available laminated-object-manufacturing machine that was originally designed for building woodlike 3D objects from paper and was modified to accept sheets of ceramic precursor material, and 2) A machine designed specifically to feed single sheets of ceramic precursor material to the laminated-object-manufacturing machine. Like other rapid-prototyping processes that utilize stacking of thin sheets, this process begins with generation of the computational model of the part to be fabricated, followed by computational sectioning of the part into layers of predetermined thickness that collectively define the shape of the part. Information about each layer is transmitted to rapid-prototyping equipment, where the part is built layer by layer. What distinguishes this process from other rapid-prototyping processes that utilize stacking of thin sheets are the details of the machines and the actions that they perform. In this process, flexible sheets of ceramic precursor material (called "green" ceramic sheets) suitable for lamination are produced by tape casting. The binder used in the tape casting is specially formulated to enable lamination of layers with little or no applied heat or pressure. The tape is cut into individual sheets, which are stacked in the sheet-feeding machine until used. The sheet-feeding machine can hold enough sheets for about 8 hours of continuous operation.

A comparative study of optical and radiative characteristics of X-ray-induced luminescent defects in Ag-doped glass and LiF thin films and their applications in 2-D imaging

NASA Astrophysics Data System (ADS)

Kurobori, T.; Miyamoto, Y.; Maruyama, Y.; Yamamoto, T.; Sasaki, T.

2014-05-01

We report novel disk-type X-ray two-dimensional (2-D) imaging detectors utilising Ag-doped phosphate glass and lithium fluoride (LiF) thin films based on the radiophotoluminescence (RPL) and photoluminescence (PL) phenomena, respectively. The accumulated X-ray doses written in the form of atomic-scale Ag-related luminescent centres in Ag-doped glass and F-aggregated centres in LiF thin films were rapidly reconstructed as a dose distribution using a homemade readout system. The 2-D images reconstructed from the RPL and PL detectors are compared with that from the optically stimulated luminescence (OSL) detector. In addition, the optical and dosimetric characteristics of LiF thin films are investigated and evaluated. The possibilities of dose distributions with a high spatial resolution on the order of microns over large areas, a wide dynamic range covering 11 orders of magnitude and a non-destructive readout are successfully demonstrated by combining the Ag-doped glass with LiF thin films.

Development of Cu Clad Cu-Zr Based Metallic Glass and Its Solderability

NASA Astrophysics Data System (ADS)

Terajima, Takeshi; Kimura, Hisamichi; Inoue, Akihisa

Soldering is a candidate technique for joining metallic glasses. It can be processed far below the crystallization temperatures of the various metallic glasses so that there is no possibility of crystallization. However, wettability of Cu-Zr based metallic glass by Pb free solder is poor because a strong surface oxide film interferes direct contact between them. To overcome the problem, Cu thin film clad metallic glass was developed. It was preliminary produced by casting a melt of Cu36Zr48Al8Ag8 pre-alloy into Cu mold cavity, inside which Cu thin film with 2 mm in thickness was set on the wall. Cu36Zr48Al8Ag8 metallic glass, whose surface Cu thin film was welded to, was successfully produced. From the microstructure analyses, it was found that reaction layer was formed at the interface between Cu and Cu36Zr48Al8Ag8 metallic glass, however, there was no oxide in the Cu clad layer. Solderability to the metallic glass was drastically increased. The Cu clad layer played an important role to prevent the formation of surface oxide film and consequently improved the solderability.

Biomimetic Mineralization of Gold Nanoclusters as Multifunctional Thin Films for Glass Nanopore Modification, Characterization, and Sensing.

PubMed

Cao, Sumei; Ding, Shushu; Liu, Yingzi; Zhu, Anwei; Shi, Guoyue

2017-08-01

Hurdles of nanopore modification and characterization restrain the development of glass capillary-based nanopore sensing platforms. In this article, a simple but effective biomimetic mineralization method was developed to decorate glass nanopore with a thin film of bovine serum albumin-protected Au nanocluster (BSA-Au NC). The BSA-Au NC film emitted a strong red fluorescence whereby nondestructive characterization of Au film decorated at the inner surface of glass nanopore can be facilely achieved by a fluorescence microscopy. Besides, the BSA molecules played dual roles in the fabrication of functionalized Au thin film in glass nanopore: they not only directed the synthesis of fluorescent Au thin film but also provided binding sites for recognition, thus achieving synthesis-modification integration. This occurred due to the ionized carboxyl groups (-COO - ) of a BSA coating layer on Au NCs which can interacted with arginine (Arg) via guanidinium groups. The added Arg selectively led to the change in the charge and ionic current of BSA-Au NC film-decorated glass nanopore. Such ionic current responses can be used for quantifying Arg with a detection limit down to 1 fM, which was more sensitive than that of previous sensing systems. Together, the designed method exhibited great promise in providing a facile and controllable solution for glass nanopore modification, characterization, and sensing.

Nonlinear distortion of thin liquid sheets

NASA Astrophysics Data System (ADS)

Mehring, Carsten Ralf

Thin planar, annular and conical liquid sheets or films are analyzed, in a unified manner, by means of a reduced- dimension approach providing governing equations for the nonlinear motion of planar and swirling annular thin inviscid and incompressible liquid sheets in zero gravity and with axial disturbances only. Temporal analyses of periodically disturbed infinite sheets are considered, as well as spatial analyses of semi-infinite sheets modulated at the nozzle exit. Results on planar and swirling annular or conical sheets are presented for a zero density ambient gas. Here, conical sheets are obtained in the nearfield of the nozzle exit by considering sheets or films with swirl in excess of that needed to stabilize the discharging stream in its annular configuration. For nonswirling annular sheets a spatially and/or temporally constant gas-core pressure is assumed. A model extension considering the influence of aerodynamic effects on planar sheets is proposed. For planar and annular sheets, linear analyses of the pure initial- and pure boundary-value problem provide insight into the propagation characteristics of dilational and sinuous waves, the (linear) coupling between both wave modes, the stability limits for the annular configuration, as well as the appearance of particular waves on semi-infinite modulated sheets downstream from the nozzle exit. Nonlinear steady-state solutions for the conical configuration (without modulation) are illustrated. Comparison between nonlinear and linear numerical and linear analytical solutions for temporally or spatially developing sheets provides detailed information on the nonlinear distortion characteristics including nonlinear wave propagation and mode-coupling for all the considered geometric configurations and for a variety of parameter configurations. Sensitivity studies on the influence of Weber number, modulation frequency, annular radius, forcing amplitude and sheet divergence on breakup or collapse length and times are reported for modulated semi-infinite annular and conical sheets. Comparisons between the different geometric configurations are made. For periodically disturbed planar sheets, accuracy of the employed reduced-dimension approach is demonstrated by comparison with more accurate two-dimensional vortex dynamics simulations.

Investigation into Composites Property Effect on the Forming Limits of Multi-Layer Hybrid Sheets Using Hydroforming Technology

NASA Astrophysics Data System (ADS)

Liu, Shichen; Lang, Lihui; Guan, Shiwei; Alexandrov, Seigei; Zeng, Yipan

2018-04-01

Fiber-metal laminates (FMLs) such as Kevlar reinforced aluminum laminate (ARALL), Carbon reinforced aluminum laminate (CARALL), and Glass reinforced aluminum laminate (GLARE) offer great potential for weight reduction applications in automobile and aerospace construction. In order to investigate the feasibility for utilizing such materials in the form of laminates, sheet hydroforming technology are studied under the condition of uniform blank holder force for three-layered aluminum and aluminum-composite laminates using orthogonal carbon and Kevlar as well as glass fiber in the middle. The experimental results validate the finite element results and they exhibited that the forming limit of glass fiber in the middle is the highest among the studied materials, while carbon fiber material performs the worst. Furthermore, the crack modes are different for the three kinds of fiber materials investigated in the research. This study provides fundamental guidance for the selection of multi-layer sheet materials in the future manufacturing field.

Edge-defined film-fed growth of thin silicon sheets

NASA Technical Reports Server (NTRS)

Ettouney, H. M.; Kalejs, J. P.

1984-01-01

Finite element analysis was used on two length scales to understand crystal growth of thin silicon sheets. Thermal-capillary models of entire ribbon growth systems were developed. Microscopic modeling of morphological structure of melt/solid interfaces beyond the point of linear instability was carried out. The application to silicon system is discussed.

Optical Properties and Electrochemical Performance of LiFePO4 Thin Films Deposited on Transparent Current Collectors.

PubMed

Lee, HyunSeok; Yim, Haena; Kim, Kwang-Bum; Choi, Ji-Won

2015-11-01

LiFePO4 thin film cathodes are deposited on various transparent conducting oxide thin films on glass, which are used as cathode current collectors. The XRD patterns show that the thin films have the phase of LiFePO4 with an ordered olivine structure indexed to the orthorhombic Pmna space group. LiFePO4 thin film deposited on various TCO glass substrates exhibits transmittance of about 53%. The initial specific discharge capacities of LiFePO4 thin films are 25.0 μAh/cm2 x μm on FTO, 33.0 μAh/cm2 x μm on ITO, and 13.0 μAh/cm2 x μm on AZO coated glass substrates. Interestingly, the retention capacities of LiFePO4 thin films are 76.0% on FTO, 31.2% on ITO, and 37.7% on AZO coated glass substrates at 20th cycle. The initial specific discharge capacity of the LiFePO4/FTO electrode is slightly lower, but the discharge capacities of the LiFePO4/FTO electrode relatively decrease less than those of the others such as LiFePO4/ITO and LiFePO4/AZO with cycling. The results reported here provide the high transparency of LiFePO4 thin films cathode materials and the good candidate as FTO current collector of the LiFePO4 thin film cathode of transparent thin film rechargeable batteries due to its high transparency and cyclic retention.

CURRENT SHEET THINNING AND ENTROPY CONSTRAINTS DURING THE SUBSTORM GROWTH PHASE

NASA Astrophysics Data System (ADS)

Otto, A.; Hall, F., IV

2009-12-01

A typical property during the growth phase of geomagnetic substorms is the thinning of the near-Earth current sheet, most pronounced in the region between 6 and 15 R_E. We propose that the cause for the current sheet thinning is convection from the midnight tail region to the dayside to replenish magnetospheric magnetic flux which is eroded at the dayside as a result of dayside reconnection. Adiabatic convection from the near-Earth tail region toward the dayside must conserve the entropy on magnetic field lines. This constraint prohibits a source of the magnetic flux from a region further out in the magnetotail. Thus the near-Earth tail region is increasingly depleted of magnetic flux (the Erickson and Wolf [1980] problem) with entropy matching that of flux tubes that are eroded on the dayside. It is proposed that the magnetic flux depletion in the near-Earth tail forces the formation of thin current layers. The process is documented by three-dimensional MHD simulations. It is shown that the simulations yield a time scale, location, and other general characteristics of the current sheet evolution during the substorm growth phase.

Heterojunction solar cell with 6% efficiency based on an n-type aluminum-gallium-oxide thin film and p-type sodium-doped Cu2O sheet

NASA Astrophysics Data System (ADS)

Minami, Tadatsugu; Nishi, Yuki; Miyata, Toshihiro

2015-02-01

In this paper, we describe efforts to enhance the efficiency of Cu2O-based heterojunction solar cells fabricated with an aluminum-gallium-oxide (Al-Ga-O) thin film as the n-type layer and a p-type sodium (Na)-doped Cu2O (Cu2O:Na) sheet prepared by thermally oxidizing copper sheets. The optimal Al content [X; Al/(Ga + Al) atomic ratio] of an AlX-Ga1-X-O thin-film n-type layer was found to be approximately 2.5 at. %. The optimized resistivity was approximately 15 Ω cm for n-type AlX-Ga1-X-O/p-type Cu2O:Na heterojunction solar cells. A MgF2/AZO/Al0.025-Ga0.975-O/Cu2O:Na heterojunction solar cell with 6.1% efficiency was fabricated using a 60-nm-thick n-type oxide thin-film layer and a 0.2-mm-thick Cu2O:Na sheet with the optimized resistivity.

Flapping dynamics of a thin liquid sheet

NASA Astrophysics Data System (ADS)

Vadivukkarasan, M.; Kumaran, Dhivyaraja; Panchagnula, Mahesh; Multi-phase flow physics Group Team

2017-11-01

We attempt to delineate and describe the complete evolution of a thin soap film when air is blown through a nozzle in the normal direction. The sequence of events and its intrinsic dynamics are captured using high speed imaging. By careful observation, it was observed that multiple mechanisms occur in the same system and each event is triggered by an independent mechanism. The events include (a) flapping of a liquid sheet and pinching of the bubble, (b) onset of rupture on the liquid sheet, (c) formation of ligaments and (d) ejection of drops. From this study, it is shown that these events are predominantly governed by Kelvin-Helmholtz instability, Taylor - Culick law, Rayleigh-Taylor instability and capillary instability, respectively. The present experiments can be considered as an extension to the previous studies on soap films as well as thin flapping sheets which has direct relevance to coaxial atomizers used in aircraft applications.

Preliminary Investigation of Impact on Multiple-Sheet Structures and an Evaluation of the Meteoroid Hazard to Space Vehicles

NASA Technical Reports Server (NTRS)

Nysmith, C. Robert; Summers, James L.

1961-01-01

Small pyrex glass spheres, representative of stoney meteoroids, were fired into 2024-T3 aluminum alclad multiple-sheet structures at velocities to 11,000 feet per second to evaluate the effectiveness of multisheet hull construction as a means of increasing the resistance of a spacecraft to meteoroid penetrations. The results of these tests indicate that increasing the number of sheets in a structure while keeping the total sheet thickness constant and increasing the spacing between sheets both tend to increase the penetration resistance of a structure of constant weight per unit area. In addition, filling the space between the sheets with a light filler material was found to substantially increase structure penetration resistance with a small increase in weight. An evaluation of the meteoroid hazard to space vehicles is presented in the form of an illustrative-example for two specific lunar mission vehicles, a single-sheet, monocoque hull vehicle and a glass-wool filled, double-sheet hull vehicle. The evaluation is presented in terms of the "best" and the "worst" conditions that might be expected as determined from astronomical and satellite measurements, high-speed impact data, and hypothesized meteoroid structures and compositions. It was observed that the vehicle flight time without penetration can be increased significantly by use of multiple-sheet rather than single-sheet hull construction with no increase in hull weight. Nevertheless, it is evident that a meteoroid hazard exists, even for the vehicle with the selected multiple-sheet hull.

Thin lead sheets in the decorative features in Pavia Charterhouse.

PubMed

Colombo, Chiara; Realini, Marco; Sansonetti, Antonio; Rampazzi, Laura; Casadio, Francesca

2006-01-01

The facade of the church of the Pavia Charterhouse, built at the end of the 15th century, shows outstanding decorative features made of different stone materials, such as marbles, breccias and sandstones. Magnificent ornamental elements are made of thin lead sheets, and some marble slabs are inlaid with them. Metal elements are shaped in complex geometric and phytomorphic design, to form a Greek fret in black contrasting with the white Carrara marble. Lead pins were fixed to the back of the thin lead sheets with the aim of attaching the metal elements to the marble; in so doing the pins and the lead sheets constitute a single piece of metal. In some areas, lead elements have been lost, and they have been substituted with a black plaster, matching the colour of the metal. To the authors' knowledge, this kind of decorative technique is rare, and confirms the refinement of Renaissance Lombard architecture. This work reports on the results of an extensive survey of the white, orange and yellowish layers, which are present on the external surface of the lead. The thin lead sheets have been characterized and their state of conservation has been studied with the aid of Optical Microscopy, SEM-EDS, FTIR and Raman analyses. Lead sulphate, lead carbonates and oxides have been identified as decay products.

Temperature-time dependent transmittance, sheet resistance and bonding energy of reduced graphene oxide on soda lime glass

NASA Astrophysics Data System (ADS)

Kumar, Raj; Kumar, R. Manoj; Bera, Parthasarathi; Ariharan, S.; Lahiri, Debrupa; Lahiri, Indranil

2017-12-01

Reduced graphene oxide coated soda lime glass can act as an alternative transparent/conducting electrode for many opto-electronic applications. However, bonding between the deposited reduced graphene oxide film and the glass substrate is important for achieving better stability of the coating and an extended device lifetime. In the present study, delamination energy of reduced graphene oxide on soda lime glass was quantified by using nanoscratch technique. Graphene oxide was deposited on soda lime glass by dip coating technique and was thermally reduced at different temperatures (100 °C, 200 °C, 300 °C, 400 °C and 500 °C) and treatment time (2 h, 3 h, 4 h, 5 h and 10 h) in Ar (95%) with H2 (5%) atmosphere. An inverse behavior of delamination energy with temperature and treatment time was observed, which could be correlated with the removal of oxygen functional groups. Sheet resistance of the film demonstrated a steady decay with increasing temperature and treatment time. Functional groups attached to the graphene planes have more influence on conductivity than groups attached to the edges. Removal of functional groups could also be related to optical transmittance of the samples. Knowledge generated in this study with respect to delamination energy, sheet resistance and optical transmittance could be extensively used for various opto-electronic applications.

Method of constructing dished ion thruster grids to provide hole array spacing compensation

NASA Technical Reports Server (NTRS)

Banks, B. A. (Inventor)

1976-01-01

The center-to-center spacings of a photoresist pattern for an array of holes applied to a thin metal sheet are increased by uniformly stretching the thin metal sheet in all directions along the plane of the sheet. The uniform stretching is provided by securely clamping the periphery of the sheet and applying an annular force against the face of the sheet, within the periphery of the sheet and around the photoresist pattern. The technique is used in the construction of ion thruster grid units where the outer or downstream grid is subjected to uniform stretching prior to convex molding. The technique provides alignment of the holes of grid pairs so as to direct the ion beamlets in a direction parallel to the axis of the grid unit and thereby provide optimization of the available thrust.

Thinning of the ice sheet in northwest Greenland over the past forty years.

PubMed

Paterson, W S; Reeh, N

2001-11-01

Thermal expansion of the oceans, as well as melting of glaciers, ice sheets and ice caps have been the main contributors to global sea level rise over the past century. The greatest uncertainty in predicting future sea level changes lies with our estimates of the mass balance of the ice sheets in Greenland and Antarctica. Satellite measurements have been used to determine changes in these ice sheets on short timescales, demonstrating that surface-elevation changes on timescales of decades or less result mainly from variations in snow accumulation. Here we present direct measurements of the changes in surface elevation between 1954 and 1995 on a traverse across the north Greenland ice sheet. Measurements over a time interval of this length should reflect changes in ice flow-the important quantity for predicting changes in sea level-relatively unperturbed by short-term fluctuations in snow accumulation. We find only small changes in the eastern part of the transect, except for some thickening of the north ice stream. On the west side, however, the thinning rates of the ice sheet are significantly higher and thinning extends to higher elevations than had been anticipated from previous studies.

Stability of Thin Liquid Sheet Flows

NASA Technical Reports Server (NTRS)

McConley, Marc W.; Chubb, Donald L.; McMaster, Matthew S.; Afjeh, Abdollah A.

1997-01-01

A two-dimensional, linear stability analysis of a thin nonplanar liquid sheet flow in vacuum is carried out. A sheet flow created by a narrow slit of W and tau attains a nonplanar cross section as a consequence of cylinders forming on the sheet edge under the influence of surface tension forces. The region where these edge cylinders join the sheet is one of high curvature, and this is found to be the location where instability is most likely to occur. The sheet flow is found to be unstable, but with low growth rates for symmetric wave disturbances and high growth rates for antisymmetric disturbances. By combining the symmetric and antisymmetric disturbance modes, a wide range of stability characteristics is obtained. The product of unstable growth rate and flow time is proportional to the width-to-thickness ratio of the sift generating the sheet Three-dimensional effects can alter these results, particularly when the sheet length-to-width ratio is not much greater than unity.

ISEE-1 and 2 observations of field-aligned currents in the distant midnight magnetosphere

NASA Technical Reports Server (NTRS)

Elphic, R. C.; Kelly, T. J.; Russell, C. T.

1985-01-01

Magnetic field measurements obtained in the nightside magnetosphere by the co-orbiting ISEE-1 and 2 spacecraft have been examined for signatures of field-aligned currents (FAC). Such currents are found on the boundary of the plasma sheet both when the plasma sheet is expanding and when it is thinning. Evidence is often found for the existence of waves on the plasma sheet boundary, leading to multiple crossings of the FAC sheet. At times the boundary layer FAC sheet orientation is nearly parallel to the X-Z GSM plane, suggesting 'protrusions' of plasma sheet into the lobes. The boundary layer current polarity is, as expected, into the ionosphere in the midnight to dawn local time sector, and outward near dusk. Current sheet thicknesses and velocities are essentially independent of plasma sheet expansion or thinning, having typical values of 1500 km and 20-40 km/s respectively. Characteristic boundary layer current densities are about 10 nanoamps per square meter.

Nonguiding Center Motion and Substorm Effects in the Magnetotail

NASA Technical Reports Server (NTRS)

Kaufmann, Richard L.; Kontodinas, Ioannis D.; Ball, Bryan M.; Larson, Douglas J.

1997-01-01

Thick and thin models of the middle magnetotail were developed using a consistent orbit tracing technique. It was found that currents carried near the equator by groups of ions with anisotropic distribution functions are not well approximated by the guiding center expressions. The guiding center equations fail primarily because the calculated pressure tensor is not magnetic field aligned. The pressure tensor becomes field aligned as one moves away from the equator, but here there is a small region in which the guiding center equations remain inadequate because the two perpendicular components of the pressure tensor are unequal. The significance of nonguiding center motion to substorm processes then was examined. One mechanism that may disrupt a thin cross-tail current sheet involves field changes that cause ions to begin following chaotic orbits. The lowest-altitude chaotic region, characterized by an adiabaticity parameter kappa approx. equal to 0.8, is especially important. The average cross-tail particle drift is slow, and we were unable to generate a thin current sheet using such ions. Therefore, any process that tends to create a thin current sheet in a region with kappa approaching 0.8 may cause the cross-tail current to get so low that it becomes insufficient to support the lobes. A different limit may be important in resonant orbit regions of a thin current sheet because particles reach a maximum cross-tail drift velocity. If the number of ions per unit length decreases as the tail is stretched, this part of the plasma sheet also may become unable to carry the cross-tail current needed to support the lobes. Thin sheets are needed for both resonant and chaotic orbit mechanisms because the distribution function must be highly structured. A description of current continuity is included to show how field aligned currents can evolve during the transition from a two-dimensional (2-D) to a 3-D configuration.

Fixation of the stressed state of glass plates by coating them with thin films using a plasma focus installation

NASA Astrophysics Data System (ADS)

Kolokoltsev, V. N.; Degtiarev, V. F.; Borovitskaya, I. V.; Nikulin, V. Ya.; Peregudova, E. N.; Silin, P. V.; Eriskin, A. A.

2018-01-01

Elastic deformation in transparent mediums is usually studied by the photoelasticity method. For opaque mediums the method of film coating and strain gauge method are used. After the external load was removed, the interference pattern corresponding to elastic deformation of the material disappears. It is found that the elastic deformation state of the thin glass plate under the action of concentrated load can be fixed during the deposition of a thin metal film. Deposition of thin copper films was carried out by passing of plasma through the copper tube installed inside the Plasma Focus installation. After removing of the load, interference pattern on the glass plates was observed in the form of Newton’s rings and isogers in non-monochromatic light on the CCD scanners which uses uorescent lamps with cold cathode. It is supposed that the copper film fixes the relief of the surface of the glass plate at the time of deformation and saves it when the load is removed. In the case of a concentrated load, this relief has the shape of a thin lens of large radius. For this reason, the interference of coherent light rays in a thin air gap between the glass of the scanners atbed and the lens surface has the shape of Newton's rings. In this case, when scanning the back side of the plate, isogyres are observed. The presented method can be used in the analysis of the mechanical stress in a various optical elements.

Thin glass substrates for mobile applications

NASA Astrophysics Data System (ADS)

Mauch, Reiner H.; Wegener, Holger; Kruse, Anke; Hildebrand, Norbert

2000-10-01

Flat panel displays play an important role as the visual interface for today's electronic devices (Notebook computers, PDA's, pagers, mobile phones, etc.). Liquid Crystal Display's are dominating the market. While for higher resolution displays active matrix displays like Thin Film Transistor LCD's are used, portable devices are mainly using Super Twisted Nematic (STN) displays. Based on the application, STN displays for mobile applications require thinner glass substrates with improved surface quality at a lower cost. The requirements and trends for STN glass substrates are identified and discussed. Different glass manufacturing processes are used today for the manufacture of these substrates. Advantages and disadvantages of the different glass substrate types are presented and discussed.

Seebeck coefficient of synthesized Titanium Dioxide thin film on FTO glass substrate

NASA Astrophysics Data System (ADS)

Usop, R.; Hamed, N. K. A.; Megat Hasnan, M. M. I.; Ikeda, H.; Sabri, M. F. M.; Ahmad, M. K.; Said, S. M.; Salleh, F.

2018-04-01

In order to fabricate a thermoelectric device on glass substrate for harvesting waste heat energy through house appliances, the Seebeck coefficient of translucent TiO2 thin film was investigated. The TiO2 thin film was synthesized by using hydrothermal method with F-SnO2 coated glass as substrate. From scanning electron microscopy analysis, the synthesized TiO2 thin film was found to be in nanometer-scale rod structure with a thickness of 4 µm. The Seebeck coefficient was measured in the temperature range of 300 – 400 K. The Seebeck coefficient is found to be in negative value which shows that synthesized film is an n-type semiconductor material, and is lower than the value of bulk-size material. This reduction in Seebeck coefficient of TiO2 thin film is likely due to the low dimensional effect and the difference of carrier concentration.

Inland thinning on the Greenland ice sheet controlled by outlet glacier geometry

NASA Astrophysics Data System (ADS)

Felikson, Denis; Bartholomaus, Timothy C.; Catania, Ginny A.; Korsgaard, Niels J.; Kjær, Kurt H.; Morlighem, Mathieu; Noël, Brice; van den Broeke, Michiel; Stearns, Leigh A.; Shroyer, Emily L.; Sutherland, David A.; Nash, Jonathan D.

2017-04-01

Greenland’s contribution to future sea-level rise remains uncertain and a wide range of upper and lower bounds has been proposed. These predictions depend strongly on how mass loss--which is focused at the termini of marine-terminating outlet glaciers--can penetrate inland to the ice-sheet interior. Previous studies have shown that, at regional scales, Greenland ice sheet mass loss is correlated with atmospheric and oceanic warming. However, mass loss within individual outlet glacier catchments exhibits unexplained heterogeneity, hindering our ability to project ice-sheet response to future environmental forcing. Using digital elevation model differencing, we spatially resolve the dynamic portion of surface elevation change from 1985 to present within 16 outlet glacier catchments in West Greenland, where significant heterogeneity in ice loss exists. We show that the up-glacier extent of thinning and, thus, mass loss, is limited by glacier geometry. We find that 94% of the total dynamic loss occurs between the terminus and the location where the down-glacier advective speed of a kinematic wave of thinning is at least three times larger than its diffusive speed. This empirical threshold enables the identification of glaciers that are not currently thinning but are most susceptible to future thinning in the coming decades.

Redox-active ionic-liquid-assisted one-step general method for preparing gold nanoparticle thin films: applications in refractive index sensing and catalysis.

PubMed

Dinda, Enakshi; Rashid, Md Harunar; Biswas, Mrinmoy; Mandal, Tarun K

2010-11-16

We describe a general one-step facile method for depositing gold nanoparticle (GNP) thin films onto any type of substrates by the in situ reduction of AuCl(3) using a newly designed redox-active ionic liquid (IL), tetrabutylphosphonium citrate ([TBP][Ci]). Various substrates such as positively charged glass, negatively charged glass/quartz, neutral hydrophobic glass, polypropylene, polystyrene, plain paper, and cellophane paper are successfully coated with a thin film of GNPs. This IL ([TBP][Ci]) is prepared by the simple neutralization of tetrabutylphosphonium hydroxide with citric acid. We also demonstrate that the [TBP][Ci] ionic liquid can be successfully used to generate GNPs in an aqueous colloidal suspension in situ. The deposited GNP thin films on various surfaces are made up of mostly discrete spherical GNPs that are well distributed throughout the film, as confirmed by field-emission scanning electron microscopy. However, it seems that some GNPs are arranged to form arrays depending on the nature of surface. We also characterize these GNP thin films via UV-vis spectroscopy and X-ray diffractometry. The as-formed GNP thin films show excellent stability toward solvent washing. We demonstrate that the thin film of GNPs on a glass/quartz surface can be successfully used as a refractive index (RI) sensor for different polar and nonpolar organic solvents. The as-formed GNP thin films on different surfaces show excellent catalytic activity in the borohydride reduction of p-nitrophenol.

Evaluation available encapsulation materials for low-cost long-life silicon photovoltaic arrays

NASA Technical Reports Server (NTRS)

Carmichael, D. C.; Gaines, G. B.; Noel, G. T.; Sliemers, F. A.; Nance, G. P.; Bunk, A. R.; Brockway, M. C.

1978-01-01

Experimental evaluation of selected encapsulation designs and materials based on an earlier study which have potential for use in low cost, long-life photovoltaic arrays are reported. The performance of candidate materials and encapsulated cells were evaluated principally for three types of encapsulation designs based on their potentially low materials and processing costs: (1) polymeric coatings, transparent conformal coatings over the cell with a structural-support substrate; (2) polymeric film lamination, cells laminated between two films or sheets of polymeric materials; and (3) glass-covered systems, cells adhesively bonded to a glass cover (superstrate) with a polymeric pottant and a glass or other substrate material. Several other design types, including those utilizing polymer sheet and pottant materials, were also included in the investigation.

Alternate methods of applying diffusants to silicon solar cells. [screen printing of thick-film paste materials and vapor phase transport from solid sources

NASA Technical Reports Server (NTRS)

Brock, T. W.; Field, M. B.

1979-01-01

Low-melting phosphate and borate glasses were screen printed on silicon wafers and heated to form n and p junctions. Data on surface appearance, sheet resistance and junction depth are presented. Similar data are reported for vapor phase transport from sintered aluminum metaphosphate and boron-containing glass-ceramic solid sources. Simultaneous diffusion of an N(+) layer with screen-printed glass and a p(+) layer with screen-printed Al alloy paste was attempted. No p(+) back surface field formation was achieved. Some good cells were produced but the heating in an endless-belt furnace caused a large scatter in sheet resistance and junction depth for three separate lots of wafers.

Method for making thin carbon foam electrodes

DOEpatents

Pekala, Richard W.; Mayer, Steven T.; Kaschmitter, James L.; Morrison, Robert L.

1999-01-01

A method for fabricating thin, flat carbon electrodes by infiltrating highly porous carbon papers, membranes, felts, metal fibers/powders, or fabrics with an appropriate carbon foam precursor material. The infiltrated carbon paper, for example, is then cured to form a gel-saturated carbon paper, which is subsequently dried and pyrolyzed to form a thin sheet of porous carbon. The material readily stays flat and flexible during curing and pyrolyzing to form thin sheets. Precursor materials include polyacrylonitrile (PAN), polymethylacrylonitrile (PMAN), resorcinol/formaldehyde, catechol/formaldehyde, phenol/formaldehyde, etc., or mixtures thereof. These thin films are ideal for use as high power and energy electrodes in batteries, capacitors, and fuel cells, and are potentially useful for capacitive deionization, filtration and catalysis.

Effect of Annealing on Mechanical Properties and Formability of Cold Rolled Thin Sheets of Fe-P P/M Alloys

NASA Astrophysics Data System (ADS)

Trivedi, Shefali; Ravi Kumar, D.; Aravindan, S.

2016-10-01

Phosphorus in steel is known to increase strength and hardness and decrease ductility. Higher phosphorus content (more than 0.05%), however, promotes brittle behavior due to segregation of Fe3P along the grain boundaries which makes further mechanical working of these alloys difficult. In this work, thin sheets of Fe-P alloys (with phosphorus in range of 0.1-0.35%) have been developed through processing by powder metallurgy followed by hot rolling and cold rolling. The effect of phosphorus content and annealing parameters (temperature and time) on microstructure, mechanical properties, formability in biaxial stretching and fracture behavior of the cold rolled and annealed sheets has been studied. A comparison has also been made between the properties of the sheets made through P/M route and the conventional cast route with similar phosphorus content. It has been shown that thin sheets of Fe-P alloys with phosphorous up to 0.35% possessing a good combination of strength and formability can be produced through rolling of billets of these alloys made through powder metallurgy technique without the problem of segregation.

Fabrication of InGaN thin-film transistors using pulsed sputtering deposition.

PubMed

Itoh, Takeki; Kobayashi, Atsushi; Ueno, Kohei; Ohta, Jitsuo; Fujioka, Hiroshi

2016-07-07

We report the first demonstration of operational InGaN-based thin-film transistors (TFTs) on glass substrates. The key to our success was coating the glass substrate with a thin amorphous layer of HfO2, which enabled a highly c-axis-oriented growth of InGaN films using pulsed sputtering deposition. The electrical characteristics of the thin films were controlled easily by varying their In content. The optimized InGaN-TFTs exhibited a high on/off ratio of ~10(8), a field-effect mobility of ~22 cm(2) V(-1) s(-1), and a maximum current density of ~30 mA/mm. These results lay the foundation for developing high-performance electronic devices on glass substrates using group III nitride semiconductors.

Effect of substrates on Zinc Oxide thin films fabrication using sol-gel method

NASA Astrophysics Data System (ADS)

Kadir, Rosmalini Ab; Taib, Nurmalina Mohd; Ahmad, Wan Rosmaria Wan; Aziz, Anees Abdul; Sabirin Zoolfakar, Ahmad

2018-03-01

The properties of ZnO thin films were deposited on three different substrates via dip coating method was investigated. The films were prepared on glass, ITO and p-type silicon. Characterization of the film revealed that the properties of the dip coated ZnO thin films were influenced by the type of substrates. The grains on ITO and glass were ∼10 nm in size while the grains on wafer agglomerate together to form a denser film. Studies of the optical properties using UV-VIS-NIR of the fabricated films demonstrated that glass has the highest transmittance compared to ITO.

Theoretical and experimental emittance measurements for a thin liquid sheet flow

NASA Technical Reports Server (NTRS)

Englehart, Amy N.; Mcconley, Marc W.; Chubb, Donald L.

1995-01-01

Surface tension forces at the edges of a thin liquid (approximately 200 microns) sheet flow result in a triangularly shaped sheet. Such a geometry is ideal for an external flow radiator. Since the fluid must have very low vapor pressure, Dow Corning 705 silicone oil was used and the emittance of a flowing sheet of oil was determined by two methods. The emittance was derived as a function of the temperature drop between the top of the sheet and the coalescence point of the sheet, the sink temperature, the volumetric flow and the length of the sheet. the emittance for the oil was also calculated using an extinction coefficient determined from spectral transmittance data of the oil. The oil's emittance ranges from .67 to .87 depending on the sheet thickness and sheet temperature. The emittance derived from the temperature drop was slightly less than the emittance calculated from transmittance data. An investigation of temperature fluctuation upstream of the slit plate was also done. The fluctuations were determined to be negligible, not affecting the temperature drop which was due to radiation.

Ground tests of the Dynamic Albedo of Neutron instrument operation in the passive mode with a Martian soil model

NASA Astrophysics Data System (ADS)

Shvetsov, V. N.; Dubasov, P. V.; Golovin, D. V.; Kozyrev, A. S.; Krylov, A. R.; Krylov, V. A.; Litvak, M. L.; Malakhov, A. V.; Mitrofanov, I. G.; Mokrousov, M. I.; Sanin, A. B.; Timoshenko, G. N.; Vostrukhin, A. A.; Zontikov, A. O.

2017-07-01

The results of the Dynamic Albedo of Neutrons (DAN) instrument ground tests in the passive mode of operation are presented in comparison with the numerical calculations. These test series were conducted to support the current surface measurements of DAN onboard the MSL Curiosity rover. The instrument sensitivity to detect thin subsurface layers of water ice buried at different depths in the analog of Martian soil has been evaluated during these tests. The experiments have been done with a radioisotope Pu-Be neutron source (analog of the MMRTG neutron source onboard the Curiosity rover) and the Martian soil model assembled from silicon-rich window glass pane. Water ice layers were simulated with polyethylene sheets. All experiments have been performed at the test facility built at the Joint Institute for Nuclear Research (Dubna, Russia).

78 FR 42754 - Sodium Hexametaphosphate From the People's Republic of China: Continuation of Antidumping Duty Order

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-17

... hexametaphosphate is a water-soluble polyphosphate glass that consists of a distribution of polyphosphate chain... Salt; Glass H; Hexaphos; Sodaphos; Vitrafos; and BAC-N-FOS. Sodium hexametaphosphate is typically sold as a white powder or granule (crushed) and may also be sold in the form of sheets (glass) or as a...

Solar reflection panels

DOEpatents

Diver, Jr., Richard B.; Grossman, James W [Albuquerque, NM; Reshetnik, Michael [Boulder, CO

2006-07-18

A solar collector comprising a glass mirror, and a composite panel, wherein the back of the mirror is affixed to a front surface of the composite panel. The composite panel comprises a front sheet affixed to a surface of a core material, preferably a core material comprising a honeycomb structure, and a back sheet affixed to an opposite surface of the core material. The invention may further comprise a sealing strip, preferably comprising EPDM, positioned between the glass mirror and the front surface of the composite panel. The invention also is of methods of making such solar collectors.

Measurement of the refractive index dispersion of As2Se3 bulk glass and thin films prior to and after laser irradiation and annealing using prism coupling in the near- and mid-infrared spectral range

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carlie, Nathan; Anheier, Norman C.; Qiao, Hong

2011-05-01

The prism coupling technique has been utilized to measure the refractive index in the near- and mid-IR spectral region of chalcogenide glasses in bulk and thin film form. A commercial system (Metricon model 2010) has been modified with additional laser sources, detectors, and a new GaP prism to allow the measurement of refractive index dispersion over the 1.5–10.6 μm range. The instrumental error was found to be ±0.001 refractive index units across the entire wavelength region examined. Measurements on thermally evaporated AMTIR2 thin films confirmed that (i) the film deposition process provides thin films with reduced index compared to thatmore » of the bulk glass used as a target, (ii) annealing of the films increases the refractive index of the film to the level of the bulk glass used as a target to create it, and (iii) it is possible to locally increase the refractive index of the chalcogenide glass using laser exposure at 632.8 nm.« less

Measurement of the refractive index dispersion of As{sub 2}Se{sub 3} bulk glass and thin films prior to and after laser irradiation and annealing using prism coupling in the near- and mid-infrared spectral range

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carlie, N.; Petit, L.; Musgraves, J. D.

2011-05-15

The prism coupling technique has been utilized to measure the refractive index in the near- and mid-IR spectral region of chalcogenide glasses in bulk and thin film form. A commercial system (Metricon model 2010) has been modified with additional laser sources, detectors, and a new GaP prism to allow the measurement of refractive index dispersion over the 1.5-10.6 {mu}m range. The instrumental error was found to be {+-}0.001 refractive index units across the entire wavelength region examined. Measurements on thermally evaporated AMTIR2 thin films confirmed that (i) the film deposition process provides thin films with reduced index compared to thatmore » of the bulk glass used as a target, (ii) annealing of the films increases the refractive index of the film to the level of the bulk glass used as a target to create it, and (iii) it is possible to locally increase the refractive index of the chalcogenide glass using laser exposure at 632.8 nm.« less

Surface roughening and scaling behavior of vacuum-deposited SnCl{sub 2}Pc organic thin films on different substrates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Obaidulla, Sk. Md.; Giri, P. K., E-mail: giri@iitg.ernet.in; Centre for Nanotechnology, Indian Institute of Technology Guwahati, Guwahati 781039

2015-11-30

The evolution of surface morphology and scaling behavior of tin (IV) phthalocyanine dichloride (SnCl{sub 2}Pc) thin films grown on Si(100) and glass substrates have been studied using atomic force microscopy (AFM) and height-height correlation function analysis. X-ray diffraction measurement confirms the crystalline nature of the SnCl{sub 2}Pc thin film on glass substrate, while no crystallographic ordering is present for the film grown on Si substrate. The growth exponent β is found to be much larger for the film on glass substrate (0.48 ± 0.07) as compared to that on Si substrate (0.21 ± 0.08), which may be due to the high step-edge barrier, so-calledmore » Ehrlich-Schwöbel barrier, resulting in the upward dominant growth on glass substrate. From the 2D fast Fourier transform of AFM images and derived scaling exponents, we conclude that the surface evolution follows a mound like growth. These results imply the superiority of glass substrate over the Si substrate for the growth of device quality SnCl{sub 2}Pc thin film.« less

Structural comparison of Ag-Ge-S bulk glasses and thin films

NASA Astrophysics Data System (ADS)

Wang, Fei; Jain, Mukul; Dunn, Porter; de Leo, Carter; Boolchand, Punit

2007-03-01

Ternary glasses of composition (GeS3)1-xAgx (x=0.1 and 0.2) are studied in form of bulk and thin films. Bulk glasses are synthesized and examined in Raman scattering and SEM. Raman scattering results of bulk glasses show that with increasing x, an increasing fraction of the Ag additive enters the base glass as Ag^+ with S^-anions serving to form thiogermanate species with one, two and three non-bridging S^- species. SEM measurements of the bulk glass show the material is intrinsically phase separated. White colored islands are observed distributed in a dark base. The EDS measurements show islands are Ag rich and the base is relatively Ag deficient. The Ag rich islands are expected to be mainly glassy phase Ag2S. Thin films of same compositions are fabricated using thermal evaporation. Films are evaporated following two different procedures to prevent the material from spitting. One method was preheating outgas and the other method was using tungsten mesh wrapped boats. The stoichiometry and molecular structure of films under each procedure are analyzed by Raman scattering and SEM to be compared with bulk glasses.

Production of thin glass mirrors by hot slumping for x-ray telescopes: present process and ongoing development

NASA Astrophysics Data System (ADS)

Salmaso, B.; Basso, S.; Brizzolari, C.; Civitani, M.; Ghigo, M.; Pareschi, G.; Spiga, D.; Tagliaferri, G.; Vecchi, G.

2014-07-01

Thin glass foils are considered good candidates to build a segmented X-ray telescope with effective area as large as 2 m2 and angular resolution better than 5 arcsec. In order to produce thin glass mirror segments, we developed a direct hot slumping technique assisted by pressure, in which the shape of a mould is replicated onto the optical surface of the glass. In this paper we present the result obtained with AF32 (by Schott) and EAGLE XG (by Corning) glass types. The selected mould material is Zerodur K20, as it does not require any anti-sticking layer and has a good matching, in terms of Coefficient of Thermal Expansion, with both glass types. Our group already produced a few prototypes, reaching angular resolution near 20 arcsec. In this work, relevant steps forward aimed at attaining a 5 arcsec angular resolution are described, along with the tuning of few key parameters in the slumping process. The results obtained on a newly procured cylindrical Zerodur K20 mould are presented.

Forced tearing of ductile and brittle thin sheets.

PubMed

Tallinen, T; Mahadevan, L

2011-12-09

Tearing a thin sheet by forcing a rigid object through it leads to complex crack morphologies; a single oscillatory crack arises when a tool is driven laterally through a brittle sheet, while two diverging cracks and a series of concertinalike folds forms when a tool is forced laterally through a ductile sheet. On the other hand, forcing an object perpendicularly through the sheet leads to radial petallike tears in both ductile and brittle materials. To understand these different regimes we use a combination of experiments, simulations, and simple theories. In particular, we describe the transition from brittle oscillatory tearing via a single crack to ductile concertina tearing with two tears by deriving laws that describe the crack paths and wavelength of the concertina folds and provide a simple phase diagram for the morphologies in terms of the material properties of the sheet and the relative size of the tool.

Utilizing boron nitride sheets as thin supports for high resolution imaging of nanocrystals.

PubMed

Wu, Yimin A; Kirkland, Angus I; Schäffel, Franziska; Porfyrakis, Kyriakos; Young, Neil P; Briggs, G Andrew D; Warner, Jamie H

2011-05-13

We demonstrate the use of thin BN sheets as supports for imaging nanocrystals using low voltage (80 kV) aberration-corrected high resolution transmission electron microscopy. This provides an alternative to the previously utilized 2D crystal supports of graphene and graphene oxide. A simple chemical exfoliation method is applied to get few layer boron nitride (BN) sheets with micrometer-sized dimensions. This generic approach of using BN sheets as supports is shown by depositing Mn doped ZnSe nanocrystals directly onto the BN sheets and resolving the atomic structure from both the ZnSe nanocrystals and the BN support. Phase contrast images reveal moiré patterns of interference between the beams diffracted by the nanocrystals and the BN substrate that are used to determine the relative orientation of the nanocrystals with respect to the BN sheets and interference lattice planes. Double diffraction is observed and has been analyzed.

A study of thin liquid sheet flows

NASA Technical Reports Server (NTRS)

Chubb, Donald L.; Calfo, Frederick D.; Mcconley, Marc W.; Mcmaster, Matthew S.; Afjeh, Abdollah A.

1993-01-01

This study was a theoretical and experimental investigation of thin liquid sheet flows in vacuum. A sheet flow created by a narrow slit of width, W, coalesces to a point at a distance, L, as a result of surface tension forces acting at the sheet edges. As the flow coalesces, the fluid accumulates in the sheet edges. The observed triangular shape of the sheet agrees with the calculated triangular result. Experimental results for L/W as a function of Weber number, We, agree with the calculated result, L/W = the sq. root of 8We. The edge cross sectional shape is found to oscillate from elliptic to 'cigar' like to 'peanut' like and then back to elliptic in the flow direction. A theoretical one-dimensional model was developed that yielded only elliptic solutions for the edge cross section. At the points where the elliptic shapes occur, there is agreement between theory and experiment.

A study of an alignment-less lithography method as an educational resource

NASA Astrophysics Data System (ADS)

Kai, Kazuho; Shiota, Koki; Nagaoka, Shiro; Mahmood, Mohamad Rusop Bin Haji; Kawai, Akira

2016-07-01

A simplification of the lithography process was studied. The simplification method of photolithography, named "alignment-less lithography" was proposed by omitting the photomask alignment process in photolithography process using mechanically aligned photomasks and substrate by using a simple jig on which countersinks were formed. Photomasks made of glass and the photomasks made of transparent plastic sheets were prepared for the process. As the result, approximately 5µm in the case of the glass mask, and 20µm in the case of the OHP mask were obtained with repetitive accuracies, respectively. It was confirmed that the alignment-less lithography method was successful. The possibility of the application to an educational program, such as a heuristic for solving problems was suggested using the method with the OHP mask. The nMOS FET fabrication process was successfully demonstrated using this method. The feasibility of this process was confirmed. It is expected that a totally simplified device fabrication process can be achievable when combined with other simplifications, such ass the simplified impurity diffusion processes using PSG and BSG thin film as diffusion source prepared by the Sol-Gel material under normal air environment.

Moderately reverberant learning ultrasonic pinch panel.

PubMed

Nikolovski, Jean-Pierre

2013-10-01

Tactile sensing is widely used in human-computer interfaces. However, mechanical integration of touch technologies is often perceived as difficult by engineers because it often limits the freedom of style or form factor requested by designers. Recent work in active ultrasonic touch technologies has made it possible to transform thin glass plates, metallic sheets, or plastic shells into interactive surfaces. The method is based on a learning process of touch-induced, amplitude-disturbed diffraction patterns. This paper proposes, first, an evolution in the design with multiple dipole transducers that improves touch sensitivity or maximum panel size by a factor of ten, and improves robustness and usability in moderately reverberant panels, and second, defines a set of acoustic variables in the signal processing for the evaluation of sensitivity and radiating features. For proof of concept purposes, the design and process are applied to 3.2- and 6-mm-thick glass plates with variable damping conditions. Transducers are bonded to only one short side of the rectangular substrates. Measurements show that the highly sensitive free lateral sides are perfectly adapted for pinch-touch and pinch-slide interactions. The advantage of relative versus absolute touch disturbance measurement is discussed, together with tolerance to abutting contaminants.

Geometry of Thin Nematic Elastomer Sheets

NASA Astrophysics Data System (ADS)

Aharoni, Hillel; Sharon, Eran; Kupferman, Raz

A thin sheet of nematic elastomer attains 3D configurations depending on the nematic director field upon heating. In this talk we describe the intrinsic geometry of such a sheet, and derive an expression for the metric induced by general smooth nematic director fields. Furthermore, we investigate the reverse problem of constructing a director field that induces a specified 2D geometry. We provide an explicit analytical recipe for constructing any surface of revolution using this method. We demonstrate how the design of an arbitrary 2D geometry is accessible using approximate numerical methods.

Two-dimensional models for the optical response of thin films

NASA Astrophysics Data System (ADS)

Li, Yilei; Heinz, Tony F.

2018-04-01

In this work, we present a systematic study of 2D optical models for the response of thin layers of material under excitation by normally incident light. The treatment, within the framework of classical optics, analyzes a thin film supported by a semi-infinite substrate, with both the thin layer and the substrate assumed to exhibit local, isotropic linear response. Starting from the conventional three-dimensional (3D) slab model of the system, we derive a two-dimensional (2D) sheet model for the thin film in which the optical response is described by a sheet optical conductivity. We develop criteria for the applicability of this 2D sheet model for a layer with an optical thickness far smaller than the wavelength of the light. We examine in detail atomically thin semi-metallic and semiconductor van-der-Waals layers and ultrathin metal films as representative examples. Excellent agreement of the 2D sheet model with the 3D slab model is demonstrated over a broad spectral range from the radio frequency limit to the near ultraviolet. A linearized version of system response for the 2D model is also presented for the case where the influence of the optically thin layer is sufficiently weak. Analytical expressions for the applicability and accuracy of the different optical models are derived, and the appropriateness of the linearized treatment for the materials is considered. We discuss the advantages, as well as limitations, of these models for the purpose of deducing the optical response function of the thin layer from experiment. We generalize the theory to take into account in-plane anisotropy, layered thin film structures, and more general substrates. Implications of the 2D model for the transmission of light by the thin film and for the implementation of half- and totally absorbing layers are discussed.

Rapid thinning of Pine Island Glacier in the early Holocene.

PubMed

Johnson, J S; Bentley, M J; Smith, J A; Finkel, R C; Rood, D H; Gohl, K; Balco, G; Larter, R D; Schaefer, J M

2014-02-28

Pine Island Glacier, a major outlet of the West Antarctic Ice Sheet, has been undergoing rapid thinning and retreat for the past two decades. We demonstrate, using glacial-geological and geochronological data, that Pine Island Glacier (PIG) also experienced rapid thinning during the early Holocene, around 8000 years ago. Cosmogenic (10)Be concentrations in glacially transported rocks show that this thinning was sustained for decades to centuries at an average rate of more than 100 centimeters per year, which is comparable with contemporary thinning rates. The most likely mechanism was a reduction in ice shelf buttressing. Our findings reveal that PIG has experienced rapid thinning at least once in the past and that, once set in motion, rapid ice sheet changes in this region can persist for centuries.

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.

Self-organized broadband light trapping in thin film amorphous silicon solar cells.

PubMed

Martella, C; Chiappe, D; Delli Veneri, P; Mercaldo, L V; Usatii, I; Buatier de Mongeot, F

2013-06-07

Nanostructured glass substrates endowed with high aspect ratio one-dimensional corrugations are prepared by defocused ion beam erosion through a self-organized gold (Au) stencil mask. The shielding action of the stencil mask is amplified by co-deposition of gold atoms during ion bombardment. The resulting glass nanostructures enable broadband anti-reflection functionality and at the same time ensure a high efficiency for diffuse light scattering (Haze). It is demonstrated that the patterned glass substrates exhibit a better photon harvesting than the flat glass substrate in p-i-n type thin film a-Si:H solar cells.

Thin liquid sheet target capabilities for ultra-intense laser acceleration of ions at a kHz repetition rate

NASA Astrophysics Data System (ADS)

Klim, Adam; Morrison, J.; Orban, C.; Chowdhury, E.; Frische, K.; Feister, S.; Roquemore, M.

2017-10-01

The success of laser-accelerated ion experiments depends crucially on a number of factors including how thin the targets can be created. We present experimental results demonstrating extremely thin (under 200 nm) glycol sheet targets that can be used for ultra-intense laser-accelerated ion experiments conducted at the Air Force Research Laboratory at Wright-Patterson Air Force Base. Importantly, these experiments operate at a kHz repetition rate and the recovery time of the liquid targets is fast enough to allow the laser to interact with a refreshed, thin target on every shot. These thin targets can be used to produce energetic electrons, light ions, and neutrons as well as x-rays, we present results from liquid glycol targets which are useful for proton acceleration experiments via the mechanism of Target Normal Sheath Acceleration (TNSA). In future work, we will create thin sheets from deuterated water in order to perform laser-accelerated deuteron experiments. This research was sponsored by the Quantum and Non-Equilibrium Processes Division of the AFOSR, under the management of Dr. Enrique Parra, and support from the DOD HPCMP Internship Program.

Thin-Film Nanowire Networks for Transparent Conductor Applications: Simulations of Sheet Resistance and Percolation Thresholds

NASA Astrophysics Data System (ADS)

Winey, Karen I.; Mutiso, Rose M.; Sherrott, Michelle C.; Rathmell, Aaron R.; Wiley, Benjamin J.

2013-03-01

Thin-film metal nanowire networks are being pursued as a viable alternative to the expensive and brittle indium tin oxide (ITO) for transparent conductors. For high performance applications, nanowire networks must exhibit high transmittance at low sheet resistance. Previously, we have used complimentary experimental, simulation and theoretical techniques to explore the effects of filler aspect ratio (L/D), orientation, and size-dispersity on the electrical conductivity of three-dimensional rod-networks in bulk polymer nanocomposites. We adapted our 3D simulation approach and analytical percolation model to study the electrical properties of thin-film rod-networks. By fitting our simulation results to experimental results, we determined the average effective contact resistance between silver nanowires. This contact resistance was then used to quantify how the sheet resistance depends on the aspect ratio of the rods and to show that networks made of nanowires with L/D greater than 100 yield sheet resistances lower than the required 100 Ohm/sq. We also report the critical area fraction of rods required to form a percolated network in thin-film networks and provide an analytical expression for the critical area fraction as a function of L/D.

Joining of aluminum sheet and glass fiber reinforced polymer using extruded pins

NASA Astrophysics Data System (ADS)

Conte, Romina; Buhl, Johannes; Ambrogio, Giuseppina; Bambach, Markus

2018-05-01

The present contribution proposes a new approach for joining sheet metal and fiber reinforced composites. The joining process draws upon a Friction Stir Forming (FSF) process, which is performed on the metal sheet to produce slender pins. These pins are used to pierce through the composite. Joining is complete by forming a locking head out of the part if the pin sticks out of the composite. Pins of different diameters and lengths were produced from EN AW-1050 material, which were joined to glass fiber reinforced polyamide-6. The strength of the joint has been experimentally tested in order to understand the effect of the process temperature on the pins strength and therefore on the joining. The results demonstrate the feasibility of this new technique, which uses no excess material.

Development of potassium ion conducting hollow glass fibers. [potassium sulfur battery

NASA Technical Reports Server (NTRS)

Tsang, F. Y.

1974-01-01

Potassium ion conducting glasses, chemically resistant to potassium, potassium sulfide and sulfur, were made and their possible utility as the membrane material for a potassium/sulfur battery was evaluated. At least one satisfactory candidate was found. It possesses an electrical resistance which makes it usable as a membrane in the form of a fine hollow fiber. It's chemical and electrochemical resistances are excellent. The other aspects of the possible potassium sulfur battery utilizing such fine hollow fibers, including the header (or tube sheet) and a cathode current collector were studied. Several cathode materials were found to be satisfactory. None of the tube sheet materials studied possessed all the desired properties. Multi-fiber cells had very limited life-time due to physical failure of fibers at the fiber/tube sheet junctions.

Design of a medium size x-ray mirror module based on thin glass foils

NASA Astrophysics Data System (ADS)

Basso, Stefano; Civitani, Marta; Pareschi, Giovanni

2016-07-01

The hot slumping glass technology for X-ray mirror is under development and in the last years the results have been improved. Nustar is the first X-ray telescope based on slumped glass foils and it benefit is the low cost compared to the direct polishing of glass. With the slumping technique it is possible to maintain the glass mass to low values with respect to the direct polishing, but in general the angular resolution is worst. A further technique based on glass is the cold shaping of foils. The improved capabilities of manufacturing thin glass foils, pushed by the industrial application for screens, open new possibilities for X-ray mirror. The increase in strength of thin tempered glasses, the reduction of thickness errors and the good roughness of flat foils are potentially great advantages. In this paper a design of a mediumsize X-ray mirror module is analysed. It is based on integration of glass foils, stacked directly on a supporting structure that is part of the X-ray telescope using stiffening ribs as spacer between foils. The alignment of each stack is performed directly into the integration machine avoiding the necessity of the alignment of different stacked modules. A typical module (glass optic and metallic structure) provides an effective area of 10 cm2/kg at 1 keV (with a mass of about 50- 100 kg and a focal length of 10 m).

Repair and retrofit of concrete bridge girders using hybrid FRP sheets.

DOT National Transportation Integrated Search

2012-02-01

The use of carbon fibers (CF) and glass fibers (GF) were combined to strengthen potentially non-ductile flexural : members. Based on tension tests of fiber-reinforced polymer (FRP) rovings and sheets, as well as theoretical : research on hybrid FRP, ...

Thin liquid sheet target capabilities for ultra-intense laser acceleration of ions at a kHz repetition rate

NASA Astrophysics Data System (ADS)

Klim, Adam; Morrison, J. T.; Orban, C.; Feister, S.; Ngirmang, G. K.; Smith, J.; Frische, K.; Peterson, A. C.; Chowdhury, E. A.; Freeman, R. R.; Roquemore, W. M.

2016-10-01

The success of laser-accelerated ion experiments depends crucially on a number of factors including how thin the targets can be created. We present experimental results demonstrating extremely thin (under 200 nm) water sheet targets that can be used for ultra-intense laser-accelerated ion experiments conducted at the Air Force Research Laboratory at Wright-Patterson Air Force Base. Importantly, these experiments operate at a kHz repetition rate and the recovery time of the liquid targets is fast enough to allow the laser to interact with a refreshed, thin target on every shot. We present results from liquid water targets which are useful for proton acceleration experiments via the mechanism of Target Normal Sheath Acceleration (TNSA). In future work, we will create thin sheets from deuterated water in order to perform laser-accelerated deuteron experiments. This research was sponsored by the Quantum and Non-Equilibrium Processes Division of the AFOSR, under the management of Dr. Enrique Parra, and support from the DOD HPCMP Internship Program.

Line-source excited impulsive EM field response of thin plasmonic metal films

NASA Astrophysics Data System (ADS)

Štumpf, Martin; Vandenbosch, Guy A. E.

2013-08-01

In this paper, reflection against and transmission through thin plasmonic metal films, basic building blocks of many plasmonic devices, are analytically investigated directly in the time domain for an impulsive electric and magnetic line-source excitation. The electromagnetic properties of thin metallic films are modeled via the Drude model. The problem is formulated with the help of approximate thin-sheet boundary conditions and the analysis is carried out using the Cagniard-DeHoop technique. Closed-form space-time expressions are found and discussed. The obtained time-domain analytical expressions reveal the existence of the phenomenon of transient oscillatory surface effects along a plasmonic metal thin sheet. Illustrative numerical examples of transmitted/reflected pulsed fields are provided.

Method for making thin carbon foam electrodes

DOEpatents

Pekala, R.W.; Mayer, S.T.; Kaschmitter, J.L.; Morrison, R.L.

1999-08-03

A method for fabricating thin, flat carbon electrodes by infiltrating highly porous carbon papers, membranes, felts, metal fibers/powders, or fabrics with an appropriate carbon foam precursor material is disclosed. The infiltrated carbon paper, for example, is then cured to form a gel-saturated carbon paper, which is subsequently dried and pyrolyzed to form a thin sheet of porous carbon. The material readily stays flat and flexible during curing and pyrolyzing to form thin sheets. Precursor materials include polyacrylonitrile (PAN), polymethylacrylonitrile (PMAN), resorcinol/formaldehyde, catechol/formaldehyde, phenol/formaldehyde, etc., or mixtures thereof. These thin films are ideal for use as high power and energy electrodes in batteries, capacitors, and fuel cells, and are potentially useful for capacitive deionization, filtration and catalysis.

78 FR 34989 - Sodium Hexametaphosphate From the People's Republic of China: Final Results of Expedited First...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-11

... is a water-soluble polyphosphate glass that consists of a distribution of polyphosphate chain lengths..., Sodium Salt; Glass H; Hexaphos; Sodaphos; Vitrafos; and BAC-N-FOS. Sodium hexametaphosphate is typically sold as a white powder or granule (crushed) and may also be sold in the form of sheets (glass) or as a...

Plasmonic Three-Dimensional Transparent Conductor Based on Al-Doped Zinc Oxide-Coated Nanostructured Glass Using Atomic Layer Deposition

DOE PAGES

Malek, Gary A.; Aytug, Tolga; Liu, Qingfeng; ...

2015-04-02

Transparent nanostructured glass coatings, fabricated on glass substrates, with a unique three-dimensional (3D) architecture were utilized as the foundation for the design of plasmonic 3D transparent conductors. Transformation of the non-conducting 3D structure to a conducting 3D network was accomplished through atomic layer deposition of aluminum-doped zinc oxide (AZO). After AZO growth, gold nanoparticles (AuNPs) were deposited by electronbeam evaporation to enhance light trapping and decrease the overall sheet resistance. Field emission scanning electron microscopy and atomic force microcopy images revealed the highly porous, nanostructured morphology of the AZO coated glass surface along with the in-plane dimensions of the depositedmore » AuNPs. Sheet resistance measurements conducted on the coated samples verified that the electrical properties of the 3D network are comparable to that of the untextured two-dimensional AZO coated glass substrates. In addition, transmittance measurements of the glass samples coated with various AZO thicknesses showed preservation of the highly transparent nature of each sample, while the AuNPs demonstrated enhanced light scattering as well as light-trapping capability.« less

Plasmonic Three-Dimensional Transparent Conductor Based on Al-Doped Zinc Oxide-Coated Nanostructured Glass Using Atomic Layer Deposition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Malek, Gary A.; Aytug, Tolga; Liu, Qingfeng

Transparent nanostructured glass coatings, fabricated on glass substrates, with a unique three-dimensional (3D) architecture were utilized as the foundation for the design of plasmonic 3D transparent conductors. Transformation of the non-conducting 3D structure to a conducting 3D network was accomplished through atomic layer deposition of aluminum-doped zinc oxide (AZO). After AZO growth, gold nanoparticles (AuNPs) were deposited by electronbeam evaporation to enhance light trapping and decrease the overall sheet resistance. Field emission scanning electron microscopy and atomic force microcopy images revealed the highly porous, nanostructured morphology of the AZO coated glass surface along with the in-plane dimensions of the depositedmore » AuNPs. Sheet resistance measurements conducted on the coated samples verified that the electrical properties of the 3D network are comparable to that of the untextured two-dimensional AZO coated glass substrates. In addition, transmittance measurements of the glass samples coated with various AZO thicknesses showed preservation of the highly transparent nature of each sample, while the AuNPs demonstrated enhanced light scattering as well as light-trapping capability.« less

Double fillet lap of laser welding of thin sheet AZ31B Mg alloy

NASA Astrophysics Data System (ADS)

Ishak, Mahadzir; Salleh, M. N. M.

2018-05-01

In this paper, we describe the experimental laser welding of thin sheet AZ31B using double fillet lap joint method. Laser welding is capable of producing high quality weld seams especially for small weld bead on thin sheet product. In this experiment, both edges for upper and lower sheets were subjected to the laser beam from the pulse wave (PW) mode of fiber laser. Welded sample were tested their joint strength by tensile-shear strength method and the fracture loads were studied. Strength for all welded samples were investigated and the effect of laser parameters on the joint strength and appearances were studied. Pulsed energy (EP) from laser process give higher effect on joint strength compared to the welding speed (WS) and angle of irradiation (AOI). Highest joint strength was possessed by sample with high EP with the same value of WS and AOI. The strength was low due to the crack defect at the centre of weld region.

Raman and CT scan mapping of chalcogenide glass diffusion generated gradient index profiles

NASA Astrophysics Data System (ADS)

Lindberg, G. P.; Berg, R. H.; Deegan, J.; Benson, R.; Salvaggio, P. S.; Gross, N.; Weinstein, B. A.; Gibson, D.; Bayya, S.; Sanghera, J.; Nguyen, V.; Kotov, M.

2016-05-01

Metrology of a gradient index (GRIN) material is non-trivial, especially in the realm of infrared and large refractive index. Traditional methods rely on index matching fluids which are not available for indexes as high as those found in the chalcogenide glasses (2.4-3.2). By diffusing chalcogenide glasses of similar composition one can blend the properties in a continuous way. In an effort to measure this we will present data from both x-ray computed tomography scans (CT scans) and Raman mapping scans of the diffusion profiles. Proof of concept measurements on undiffused bonded sheets of chalcogenide glasses were presented previously. The profiles measured will be of axially stacked sheets of chalcogenide glasses diffused to create a linear GRIN profile and nested tubes of chalcogenide glasses diffused to create a radial parabolic GRIN profile. We will show that the x-ray absorption in the CT scan and the intensity of select Raman peaks spatially measured through the material are indicators of the concentration of the diffusion ions and correlate to the spatial change in refractive index. We will also present finite element modeling (FEM) results and compare them to post precision glass molded (PGM) elements that have undergone CT and Raman mapping.

Spectroscopic ellipsometry investigation of the optical properties of graphene oxide dip-coated on magnetron sputtered gold thin films

NASA Astrophysics Data System (ADS)

Politano, Grazia Giuseppina; Vena, Carlo; Desiderio, Giovanni; Versace, Carlo

2018-02-01

Despite intensive investigations on graphene oxide-gold nanocomposites, the interaction of graphene oxide sheets with magnetron sputtered gold thin films has not been studied yet. The optical constants of graphene oxide thin films dip-coated on magnetron sputtered gold thin films were determined by spectroscopic ellipsometry in the [300-1000] wavelength range. Moreover, the morphologic properties of the samples were investigated by SEM analysis. Graphene oxide absorbs mainly in the ultraviolet region, but when it is dip-coated on magnetron sputtered gold thin films, its optical constants show dramatic changes, becoming absorbing in the visible region, with a peak of the extinction coefficient at 3.1 eV. Using magnetron sputtered gold thin films as a substrate for graphene oxide thin films could therefore be the key to enhance graphene oxide optical sheets' properties for several technological applications, preserving their oxygen content and avoiding the reduction process.

Sinusoidal nanotextures for light management in silicon thin-film solar cells.

PubMed

Köppel, G; Rech, B; Becker, C

2016-04-28

Recent progresses in liquid phase crystallization enabled the fabrication of thin wafer quality crystalline silicon layers on low-cost glass substrates enabling conversion efficiencies up to 12.1%. Because of its indirect band gap, a thin silicon absorber layer demands for efficient measures for light management. However, the combination of high quality crystalline silicon and light trapping structures is still a critical issue. Here, we implement hexagonal 750 nm pitched sinusoidal and pillar shaped nanostructures at the sun-facing glass-silicon interface into 10 μm thin liquid phase crystallized silicon thin-film solar cell devices on glass. Both structures are experimentally studied regarding their optical and optoelectronic properties. Reflection losses are reduced over the entire wavelength range outperforming state of the art anti-reflective planar layer systems. In case of the smooth sinusoidal nanostructures these optical achievements are accompanied by an excellent electronic material quality of the silicon absorber layer enabling open circuit voltages above 600 mV and solar cell device performances comparable to the planar reference device. For wavelengths smaller than 400 nm and higher than 700 nm optical achievements are translated into an enhanced quantum efficiency of the solar cell devices. Therefore, sinusoidal nanotextures are a well-balanced compromise between optical enhancement and maintained high electronic silicon material quality which opens a promising route for future optimizations in solar cell designs for silicon thin-film solar cells on glass.

Specimen Design for Sustained Load Testing of Parallel-Laid Glass Fibre Reinforced Plastics.

DTIC Science & Technology

prepared by molding on a sheet of woven glass fabric and stripping this off just before bonding, to leave a roughened surface. The test specimens are 1/2 inch wide strips cut from the laminates. (Author, modified-PL)

40 CFR 426.24 - Pretreatment standards for existing sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Pretreatment standards for existing sources. 426.24 Section 426.24 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GLASS MANUFACTURING POINT SOURCE CATEGORY Sheet Glass Manufacturing...

40 CFR 426.24 - Pretreatment standards for existing sources.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 30 2011-07-01 2011-07-01 false Pretreatment standards for existing sources. 426.24 Section 426.24 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GLASS MANUFACTURING POINT SOURCE CATEGORY Sheet Glass Manufacturing...

40 CFR 426.26 - Pretreatment standards for new sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Pretreatment standards for new sources. 426.26 Section 426.26 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GLASS MANUFACTURING POINT SOURCE CATEGORY Sheet Glass Manufacturing Subcategory...

40 CFR 426.26 - Pretreatment standards for new sources.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 30 2011-07-01 2011-07-01 false Pretreatment standards for new sources. 426.26 Section 426.26 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GLASS MANUFACTURING POINT SOURCE CATEGORY Sheet Glass Manufacturing Subcategory...

LPG ammonia and nitrogen dioxide gas sensing properties of nanostructured polypyrrole thin film

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bagul, Sagar B., E-mail: nano.sbbagul@gmail.com; Upadhye, Deepak S.; Sharma, Ramphal, E-mail: rps.phy@gmail.com

Nanostructured Polypyrrole thin film was synthesized by easy and economic chemical oxidative polymerization technique on glass at room temperature. The prepared thin film of Polypyrrole was characterized by optical absorbance study by UV-visible spectroscopy and electrical study by I-V measurement system. The optical absorbance spectrum of Polypyrrole shows two fundamental peaks in region of 420 and 890 nm, which confirms the formation of Polypyrrole on glass substrate. The I-V graph of nanostructured Polypyrrole represents the Ohmic nature. Furthermore, the thin film of Polypyrrole was investigated by Scanning electron microscopy for surface morphology study. The SEM micrograph represents spherical nanostructured morphology ofmore » Polypyrrole on glass substrate. In order to investigate gas sensing properties, 100 ppm of LPG, Ammonia and Nitrogen Dioxide were injected in the gas chamber and magnitude of resistance has been recorded as a function of time in second. It was observed that nanostructured Polypyrrole thin film shows good sensing behavior at room temperature.« less

LPG ammonia and nitrogen dioxide gas sensing properties of nanostructured polypyrrole thin film

NASA Astrophysics Data System (ADS)

Bagul, Sagar B.; Upadhye, Deepak S.; Sharma, Ramphal

2016-05-01

Nanostructured Polypyrrole thin film was synthesized by easy and economic chemical oxidative polymerization technique on glass at room temperature. The prepared thin film of Polypyrrole was characterized by optical absorbance study by UV-visible spectroscopy and electrical study by I-V measurement system. The optical absorbance spectrum of Polypyrrole shows two fundamental peaks in region of 420 and 890 nm, which confirms the formation of Polypyrrole on glass substrate. The I-V graph of nanostructured Polypyrrole represents the Ohmic nature. Furthermore, the thin film of Polypyrrole was investigated by Scanning electron microscopy for surface morphology study. The SEM micrograph represents spherical nanostructured morphology of Polypyrrole on glass substrate. In order to investigate gas sensing properties, 100 ppm of LPG, Ammonia and Nitrogen Dioxide were injected in the gas chamber and magnitude of resistance has been recorded as a function of time in second. It was observed that nanostructured Polypyrrole thin film shows good sensing behavior at room temperature.

Horizontal electromagnetic casting of thin metal sheets

DOEpatents

Hull, John R.; Lari, Robert J.; Praeg, Walter F.; Turner, Larry R.

1987-01-01

Thin metal sheets are cast by magnetically suspending molten metal deposited within a ferromagnetic yoke and between AC conducting coils and linearly displacing the magnetically levitated liquid metal while it is being cooled to form a solid metal sheet. Magnetic flux increases as the molten metal sheet moves downward and decreases as the molten metal sheet moves upward to stabilize the sheet and maintain it in equilibrium as it is linearly displaced and solidified by cooling gases. A conducting shield is electrically coupled to the molten metal sheet by means of either metal sheet engaging rollers or brushes on the solidified metal, and by means of an electrode in the vessel containing the molten metal thereby providing a return path for the eddy currents induced in the metal sheet by the AC coil generated magnetic flux. Variation in the geometry of the conducting shield allows the magnetic flux between the metal sheet and the conducting shield to be varied and the thickness in surface quality of the metal sheet to be controlled. Side guards provide lateral containment for the molten metal sheet and stabilize and shape the magnetic field while a leader sheet having electromagnetic characteristics similar to those of the metal sheet is used to start the casting process and precedes the molten metal sheet through the magnet and forms a continuous sheet therewith. The magnet may be either U-shaped with a single racetrack coil or may be rectangular with a pair of facing bedstead coils.

Horizontal electromagnetic casting of thin metal sheets

DOEpatents

Hull, John R.; Lari, Robert J.; Praeg, Walter F.; Turner, Larry R.

1988-01-01

Thin metal sheets are cast by magnetically suspending molten metal deposited within a ferromagnetic yoke and between AC conducting coils and linearly displacing the magnetically levitated liquid metal while it is being cooled to form a solid metal sheet. Magnetic flux increases as the molten metal sheet moves downward and decreases as the molten metal sheet moves upward to stabilize the sheet and maintain it in equilibrium as it is linearly displaced and solidified by cooling gases. A conducting shield is electrically coupled to the molten metal sheet by means of either metal sheet engaging rollers or brushes on the solidified metal, and by means of an electrode in the vessel containing the molten metal thereby providing a return path for the eddy currents induced in the metal sheet by the AC coil generated magnetic flux. Variation in the geometry of the conducting shield allows the magnetic flux between the metal sheet and the conducting shield to be varied and the thickness in surface quality of the metal sheet to be controlled. Side guards provide lateral containment for the molten metal sheet and stabilize and shape the magnetic field while a leader sheet having electromagnetic characteristics similar to those of the metal sheet is used to start the casting process and precedes the molten metal sheet through the magnet and forms a continuous sheet therewith. The magnet may be either U-shaped with a single racetrack coil or may be rectangular with a pair of facing bedstead coils.

Local dynamics of glass-forming polystyrene thin films from atomistic simulation

NASA Astrophysics Data System (ADS)

Zhou, Yuxing; Milner, Scott

Despite a wide technological application ranging from protective coatings to organic solar cells, there still no consensus on the mechanism for the glass transition in polymer thin films a manifestation of the infamous glass problem under confinement. Many experimental and computational studies have observed a large deviation of nanoscale dynamical properties in thin films from the corresponding properties in bulk. In this work, we perform extensive united-atom simulations on atactic polystyrene free-standing thin films near the glass transition temperature and focus on the effect of free surface on the local dynamics. We study the segmental dynamics as a function of distance from the surface for different temperatures, from which relaxation time and thereby local Tg is obtained for each layer. We find the dynamics near free surface is not only enhanced but becomes less strongly temperature dependent as Tg is approached compared to the bulk. We find an increasing length scale associated with mobility propagation from the free surface as temperature decreases, but no correlation between local structure and enhanced relaxation rates near the surface, consistent with studies on bead-spring chains.

Discontinuous/continuous metal films grown on photosensitive glass

NASA Astrophysics Data System (ADS)

Trotter, D. M., Jr.; Smith, D. W.

1984-07-01

A new effect which allows direct formation of thin metal films of controlled morphology is described. Patterns of glass-ceramic opal are developed in photosensitive glass samples by UV irradiation and heat treatment. The samples are then ion exchanged in molten salt baths containing Ag+ or Cu+ ions. On subsequent firing in a hydrogen atmosphere, continuous films with typical thin metal films properties grow on the opal regions of the samples. Discontinuous films, characterized by activated resistivities and switching, grow on the glassy regions.

The investigation of the Cr doped ZnO thin films deposited by thermionic vacuum arc technique

NASA Astrophysics Data System (ADS)

Mohammadigharehbagh, Reza; Pat, Suat; Musaoglu, Caner; Korkmaz, Şadan; Özen, Soner

2018-02-01

Cr doped ZnO thin films were prepared onto glass and polyethylene terephthalate (PET) substrates using thermionic vacuum arc. XRD patterns show the polycrystalline nature of the films. Cr, Zn, ZnO and Cr2O3 were detected in the layers. The mean crystallite sizes of the films were calculated about 20 nm for the films onto glass and PET substrates. The maximum dislocation density and internal strain values of the films are calculated. According to the optical analysis, the average transmittance and reflectance of the films were found to be approximately 53% and 16% for glass and PET substrates, respectively. The mean refractive index of the layer decreased to 2.15 from 2.38 for the PET substrate. The band gap values of the Cr-doped ZnO thin films were determined as 3.10 and 3.13 eV for glass and PET substrates.

Preparation and characterization of silver nanoparticles homogenous thin films

NASA Astrophysics Data System (ADS)

Hegazy, Maroof A.; Borham, E.

2018-06-01

The wet chemical method by metal salt reduction has been widely used to synthesize nanoparticles. Accordingly the silver nitrate used as silver precursor and sodium borohydrate as reduction agent. The silver nanoparticles were characterized by different characterization techniques including UV-VIS spectrometry, Transmission electron microscope (TEM), and Zeta potential technique. Thin films of the colloidal solution were fabricated using direct precipitation technique on ITO glass, silicon substrate and commercial glass substrate and characterized by imaging technique. The absorption peak of the silver nanoparticles colloidal solution was around 400 nm. The TEM images indicate that the silver nanoparticles had spherical shape and their sizes were from 10 to 17 nm. The particle size of the silver nanoparticles was confirmed by Zeta potential technique. The imaging technique indicated that the homogeneous distribution of the colloidal silver solution thin film on the silicon substrate was stronger than the ITO glass and inhomogeneous film was emerged on the commercial glass.

Chalcogenide glass-ceramic with self-organized heterojunctions: application to photovoltaic solar cells

NASA Astrophysics Data System (ADS)

Zhang, Xianghua; Korolkov, Ilia; Fan, Bo; Cathelinaud, Michel; Ma, Hongli; Adam, Jean-Luc; Merdrignac, Odile; Calvez, Laurent; Lhermite, Hervé; Brizoual, Laurent Le; Pasquinelli, Marcel; Simon, Jean-Jacques

2018-03-01

In this work, we present for the first time the concept of chalcogenide glass-ceramic for photovoltaic applications with the GeSe2-Sb2Se3-CuI system. It has been demonstrated that thin films, deposited with the sputtering technique, are amorphous and can be crystallized with appropriate heat treatment. The thin film glass-ceramic behaves as a p-type semiconductor, even if it contains p-type Cu2GeSe3 and n-type Sb2Se3. The conductivity of Sb2Se3 has been greatly improved by appropriate iodine doping. The first photovoltaic solar cells based on the association of iodine-doped Sb2Se3 and the glass-ceramic thin films give a short-circuit current density JSC of 10 mA/cm2 and an open-circuit voltage VOC of 255 mV, with a power conversion efficiency of about 0.9%.

Apparatus for making photovoltaic devices

DOEpatents

Foote, James B.; Kaake, Steven A. F.; Meyers, Peter V.; Nolan, James F.

1994-12-13

A process and apparatus (70) for making a large area photovoltaic device (22) that is capable of generating low cost electrical power. The apparatus (70) for performing the process includes an enclosure (126) providing a controlled environment in which an oven (156) is located. At least one and preferably a plurality of deposition stations (74,76,78) provide heated vapors of semiconductor material within the oven (156) for continuous elevated temperature deposition of semiconductor material on a sheet substrate (24) including a glass sheet (26) conveyed within the oven. The sheet substrate (24) is conveyed on a roller conveyor (184) within the oven (156) and the semiconductor material whose main layer (82) is cadmium telluride is deposited on an upwardly facing surface (28) of the substrate by each deposition station from a location within the oven above the roller conveyor. A cooling station (86) rapidly cools the substrate (24) after deposition of the semiconductor material thereon to strengthen the glass sheet of the substrate.

Process for making photovoltaic devices and resultant product

DOEpatents

Foote, James B.; Kaake, Steven A. F.; Meyers, Peter V.; Nolan, James F.

1996-07-16

A process and apparatus (70) for making a large area photovoltaic device (22) that is capable of generating low cost electrical power. The apparatus (70) for performing the process includes an enclosure (126) providing a controlled environment in which an oven (156) is located. At least one and preferably a plurality of deposition stations (74,76,78) provide heated vapors of semiconductor material within the oven (156) for continuous elevated temperature deposition of semiconductor material on a sheet substrate (24) including a glass sheet (26) conveyed within the oven. The sheet substrate (24) is conveyed on a roller conveyor (184) within the oven (156) and the semiconductor material whose main layer (82) is cadmium telluride is deposited on an upwardly facing surface (28) of the substrate by each deposition station from a location within the oven above the roller conveyor. A cooling station (86) rapidly cools the substrate (24) after deposition of the semiconductor material thereon to strengthen the glass sheet of the substrate.

Process for making photovoltaic devices and resultant product

DOEpatents

Foote, James B.; Kaake, Steven A. F.; Meyers, Peter V.; Nolan, James F.

1995-11-28

A process and apparatus (70) for making a large area photovoltaic device (22) that is capable of generating low cost electrical power. The apparatus (70) for performing the process includes an enclosure (126) providing a controlled environment in which an oven (156) is located. At least one and preferably a plurality of deposition stations (74,76,78) provide heated vapors of semiconductor material within the oven (156) for continuous elevated temperature deposition of semiconductor material on a sheet substrate (24) including a glass sheet (26) conveyed within the oven. The sheet substrate (24) is conveyed on a roller conveyor (184) within the oven (156) and the semiconductor material whose main layer (82) is cadmium telluride is deposited on an upwardly facing surface (28) of the substrate by each deposition station from a location within the oven above the roller conveyor. A cooling station (86) rapidly cools the substrate (24) after deposition of the semiconductor material thereon to strengthen the glass sheet of the substrate.

Process for making photovoltaic devices and resultant product

DOEpatents

Foote, James B.; Kaake, Steven A. F.; Meyers, Peter V.; Nolan, James F.

1993-09-28

A process and apparatus (70) for making a large area photovoltaic device (22) that is capable of generating low cost electrical power. The apparatus (70) for performing the process includes an enclosure (126) providing a controlled environment in which an oven (156) is located. At least one and preferably a plurality of deposition stations (74,76,78) provide heated vapors of semiconductor material within the oven (156) for continuous elevated temperature deposition of semiconductor material on a sheet substrate (24) including a glass sheet (26) conveyed within the oven. The sheet substrate (24) is conveyed on a roller conveyor (184) within the oven (156) and the semiconductor material whose main layer (82) is cadmium telluride is deposited on an upwardly facing surface (28) of the substrate by each deposition station from a location within the oven above the roller conveyor. A cooling station (86) rapidly cools the substrate (24) after deposition of the semiconductor material thereon to strengthen the glass sheet of the substrate.

Up-scaling perovskite solar cell manufacturing from sheet-to-sheet to roll-to-roll: challenges and solutions

NASA Astrophysics Data System (ADS)

Di Giacomo, Francesco; Galagan, Yulia; Shanmugam, Santhosh; Gorter, Harrie; van den Bruele, Fieke; Kirchner, Gerwin; de Vries, Ike; Fledderus, Henri; Lifka, Herbert; Veenstra, Sjoerd; Aernouts, Tom; Groen, Pim; Andrissen, Ronn

2017-08-01

Organometallic halide perovskite solar cells (PSCs) are extremely promising novel materials for thin-film photovoltaics, exhibiting efficiencies over 22% on glass and over 17% on foil 1, 2 . First, a sheet-to-sheet (S2S) production of PSCs and modules on 152x152 mm2 substrates was established, using a combination of sputtering, e-beam evaporation, slot die coating and thermal evaporation (average PCE of 14.6 +/- 1.3 % over 64 devices, more than 10% initial PCE on modules). Later the steps towards a roll-to-roll production will be investigated, starting from the optimization of the stack to make it compatible with a faster production at low temperature. A water based SnOx nanoparticles dispersion was used as solution processable ETL, and the deposition process was scaled-up from spin coating to R2R slot die coating on a 300 mm wide roll of PET/ITO. R2R production is often carried out in ambient atmosphere and involve the use of large volumes of materials, thus a first point is the development of a green solvent and precursor system for the perovskite layer to prevent the emission of toxic compound in the environment. The first results on device fabrication are encouraging, which allow partial R2R manufacturing of flexible PSC (R2R coating of SnOx and perovskite, S2S for Spiro-OMeTAD and gold) with stabilized PCE of 12.6%, a remarkable value for these novel devices. This result can be considered an important milestone towards the production of efficient, low cost, lightweight, flexible PSC on large area.

The Autumn of break-ups: When Jakobshavn Isbrae lost its floating tongue

NASA Astrophysics Data System (ADS)

Aschwanden, A.; Fahnestock, M. A.; Truffer, M.; Motyka, R. J.

2015-12-01

Capturing the temporal variability in outlet glacier flow remains one of the holy grails in ice sheet modeling. Here we demonstrate progress using the three-dimensional Parallel Ice Sheet Model. Using a first-order calving law and prescribed subshelf basal melt rates, we performed high-resolution (<1km) hindcasts of the Greenland Ice Sheet of the 1989-2012 period. These hindcasts allow us to study the processes governing ice-shelf thinning, break-up, and subsequent speed-ups and dynamic thinning. Focussing our analysis on the Jakobshavn basin we show that our simulations are able to capture the thinning of the floating tongue resulting from increased subshelf basal melt rates. Furthermore, our simulations capture both the magnitude and the timing of the dynamic thinning associated with the loss of the floating tongue, as well as the speed-up. We find little seasonal variations in surface speeds prior to 1995, and strong variations thereafter, in good agreement with observations of Echelmeyer and Harrison (1991) and Joughin et al (2012).

Scanning micro-Hall probe mapping of magnetic flux distributions and current densities in YBa2Cu3O7 thin films

NASA Technical Reports Server (NTRS)

Xing, W.; Heinrich, B.; Zhou, HU; Fife, A. A.; Cragg, A. R.; Grant, P. D.

1995-01-01

Mapping of the magnetic flux density B(sub z) (perpendicular to the film plane) for a YBa2Cu3O7 thin-film sample was carried out using a scanning micro-Hall probe. The sheet magnetization and sheet current densities were calculated from the B(sub z) distributions. From the known sheet magnetization, the tangential (B(sub x,y)) and normal components of the flux density B were calculated in the vicinity of the film. It was found that the sheet current density was mostly determined by 2B(sub x,y)/d, where d is the film thickness. The evolution of flux penetration as a function of applied field will be shown.

Fabrication and convergent X-ray nanobeam diffraction characterization of submicron-thickness SrTiO 3 crystalline sheets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tilka, J. A.; Park, J.; Sampson, K. C.

The creation of thin SrTiO3 crystals from (001)-oriented SrTiO3 bulk single crystals using focused ion beam milling techniques yields sheets with submicron thickness and arbitrary orientation within the (001) plane. Synchrotron x-ray nanodiffraction rocking curve widths of these SrTiO3 sheets are less than 0.02 degrees, less than a factor of two larger than bulk SrTiO3, making these crystals suitable substrates for epitaxial thin film growth. The change in the rocking curve width is sufficiently small that we deduce that dislocations are not introduced into the SrTiO3 sheets. Observed lattice distortions are consistent with a low concentration of point defects.

InN thin-film transistors fabricated on polymer sheets using pulsed sputtering deposition at room temperature

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lye, Khe Shin; Kobayashi, Atsushi; Ueno, Kohei

Indium nitride (InN) is potentially suitable for the fabrication of high performance thin-film transistors (TFTs) because of its high electron mobility and peak electron velocity. However, InN is usually grown using a high temperature growth process, which is incompatible with large-area and lightweight TFT substrates. In this study, we report on the room temperature growth of InN films on flexible polyimide sheets using pulsed sputtering deposition. In addition, we report on the fabrication of InN-based TFTs on flexible polyimide sheets and the operation of these devices.

The Role of Annealing Process in Ag-Based BaSnO3 Multilayer Thin Films.

PubMed

Wu, Muying; Yu, Shihui; He, Lin; Yang, Lei; Zhang, Weifeng

2016-12-01

The BaSnO3/Ag/BaSnO3 multilayer structure was designed and fabricated on a quartz glass by magnetron sputtering, followed by an annealing process at a temperature from 150 to 750 °C in air. In this paper, we investigated the influence of the annealing temperature on the structural, optical, and electrical properties of the multilayers and proposed the mechanisms of conduction and transmittance. The maximum value of the figure of merit of 31.8 × 10(-3) Ω(-1) was achieved for the BaSnO3/Ag/BaSnO3 multilayer thin films annealed at 150 °C, while the average optical transmittance in the visible ranges was >84 %, the resistivity was 5.71 × 10(-5) Ω cm, and the sheet resistance was 5.57 Ω/sq. When annealed at below 600 °C, the values of resistivity and transmittance of the multilayers were within an acceptable range (resistivity <5.0 × 10(-4) Ω cm, transmittance >80 %). The observed property of the multilayer film is suitable for the application of transparent conductive electrodes.

Flexural properties of denture base polymers reinforced with a glass cloth-urethane polymer composite.

PubMed

Kanie, Takahito; Arikawa, Hiroyuki; Fujii, Koichi; Ban, Seiji

2004-10-01

A newly designed light-cured reinforcement made from urethanemethacrylate oligomer and woven glass cloth has orthotropic anisotropy. This is produced for incorporation into the outermost position under the greatest tension in denture base resins. In this study, the flexural properties of self-, heat-, and light-curing reinforced resins were determined. The silanized glass cloth was soaked in urethanemethacrylate oligomer containing camphorquinone and 2-(dimethylamino)ethylmethacrylate. It was sandwiched between two pieces of polyethylene film and pressed to form a reinforcement sheet 0.3 mm in thickness, which was light-cured and prepared using four different surface conditions: with or without the polyethylene film and with or without a bonding agent. The reinforcement sheet was fixed in a fluorocarbon resin mold 3 mm in thickness, which was filled with self-, heat-, or light-curing resin and cured. The cured laminated plate was cut for flexural testing (40 x 7 x 3 mm3). A three-point flexural test was carried out at a crosshead speed of 2 mm/min and a span length of 30 mm. In this study, the glass fiber content was measured at percentages by weight because it was not possible to determine accurately the volume of the various polymers. The baseline flexural strengths of the self-, heat-, and light-curing resins were 76.2, 68.6, and 55.6 MPa, respectively, and these values were increased to 271.7, 216.4, and 266.5 MPa by the reinforcement sheet. The baseline flexural moduli of self-, heat-, and light-curing resins were 2.0, 2.4, and 2.1 GPa, respectively. These values were increased to 7.2, 5.1, and 6.6 GPa by the reinforcement sheet. SEM photographs revealed good impregnation of the glass fiber within the polymer matrix. The differences in the flexural strengths and flexural moduli of the control and reinforced specimens were significant (p < 0.01).

Low emissivity Ag/Ta/glass multilayer thin films deposited by sputtering

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Sun Ho; Lee, Kee Sun; Green Home Energy Technology Center, Cheonan City

Ta is deposited on a glass substrate as an interlayer for the two-dimensional growth of Ag thin films because Ta has good thermal stability and can induce a negative surface-energy change in Ag/glass. From the transmission electron microscopy results, we concluded that the Ag crystals in the bottom layer (seemingly on Ag/Ta) were flattened; this was rarely observed in the three-dimensional growth mode. Comparing Ag/Ta/glass with Ag/glass, we found that the Ta interlayer was effective in reducing both the resistance and the emissivity, accompanied by the relatively high transmittance in the visible region. In particular, Ag(9 nm)/Ta(1 nm)/glass film showedmore » 0.08 of the emissivity, including {approx}61% of the transmittance in the visible region (wavelength: 550 nm).« less

Fabrication of Fresnel micro lens array in borosilicate glass by F2-laser ablation for glass interposer application

NASA Astrophysics Data System (ADS)

Brusberg, Lars; Neitz, Marcel; Schröder, Henning; Fricke-Begemann, Thomas; Ihlemann, Jürgen

2014-03-01

The future need for more bandwidth forces the development of optical transmission solutions for rack-to-rack, boardto- board and chip-to-chip interconnects. The goals are significant reduction of power consumption, highest density and potential for bandwidth scalability to overcome the limitations of the systems today with mostly copper based interconnects. For system integration the enabling of thin glass as a substrate material for electro-optical components with integrated micro-optics for efficient light coupling to integrated optical waveguides or fibers is becoming important. Our glass based packaging approach merges micro-system packaging and glass integrated optics. This kind of packaging consists of a thin glass substrate with integrated micro lenses providing a platform for photonic component assembly and optical fiber or waveguide interconnection. Thin glass is commercially available in panel and wafer size and characterizes excellent optical and high frequency properties. That makes it perfect for microsystem packaging. A suitable micro lens approach has to be comparable with different commercial glasses and withstand post-processing like soldering. A benefit of using laser ablated Fresnel lenses is the planar integration capability in the substrate for highest integration density. In the paper we introduce our glass based packaging concept and the Fresnel lens design for different scenarios like chip-to-fiber, chip-to-optical-printed-circuit-board coupling. Based on the design the Fresnel lenses were fabricated by using a 157 nm fluorine laser ablation system.

40 CFR 426.25 - Standards of performance for new sources.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 30 2011-07-01 2011-07-01 false Standards of performance for new sources. 426.25 Section 426.25 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GLASS MANUFACTURING POINT SOURCE CATEGORY Sheet Glass Manufacturing...

40 CFR 426.25 - Standards of performance for new sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Standards of performance for new sources. 426.25 Section 426.25 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GLASS MANUFACTURING POINT SOURCE CATEGORY Sheet Glass Manufacturing...

The Sol-Gel-Xerogel Transition

DTIC Science & Technology

1993-11-01

basic pH. Bioactive sol-gel glasses obtained by a surface adsorption of trypsin to a readymade xerogel were also completley * L...presence of siloxane chains and hydrophobic methyl groups an easy film deposition on glass sheets can be obtained. Rhodamine 6G and Coumarin 4 were...Research Proposal was prepared (early 1989) have witnessed a tremendous, almost explosive, progress in the field of organically doped sol-gel glasses

A review of melt and vapor growth techniques for polydiacetylene thin films for nonlinear optical applications

NASA Technical Reports Server (NTRS)

Penn, B. G.; Shields, A.; Frazier, D. O.

1988-01-01

Methods for the growth of polydiacetylene thin films by melt and vapor growth and their subsequent polymerization are summarized. Films with random orientations were obtained when glass or quartz were used as substrates in the vapor growth process. Oriented polydiacetylene films were fabricated by the vapor deposition of diacetylene monomer onto oriented polydiacetylene on a glass substrate and its subsequent polymerization by UV light. A method for the growth of oriented thin films by a melt-shear growth process as well as a method of film growth by seeded recrstallization from the melt between glass plates, that may be applied to the growth of polydiacetylene films, are described. Moreover, a method is presented for the fabrication of single crystal thin films of polyacetylenes by irradiation of the surface of diacetylene single crystals to a depth between 100 and 2000 angstroms.

Visible photoassisted room-temperature oxidizing gas-sensing behavior of Sn2S3 semiconductor sheets through facile thermal annealing.

PubMed

Liang, Yuan-Chang; Lung, Tsai-Wen; Wang, Chein-Chung

2016-12-01

Well-crystallized Sn 2 S 3 semiconductor thin films with a highly (111)-crystallographic orientation were grown using RF sputtering. The surface morphology of the Sn 2 S 3 thin films exhibited a sheet-like feature. The Sn 2 S 3 crystallites with a sheet-like surface had a sharp periphery with a thickness in a nanoscale size, and the crystallite size ranged from approximately 150 to 300 nm. Postannealing the as-synthesized Sn 2 S 3 thin films further in ambient air at 400 °C engendered roughened and oxidized surfaces on the Sn 2 S 3 thin films. Transmission electron microscopy analysis revealed that the surfaces of the Sn 2 S 3 thin films transformed into a SnO 2 phase, and well-layered Sn 2 S 3 -SnO 2 heterostructure thin films were thus formed. The Sn 2 S 3 -SnO 2 heterostructure thin film exhibited a visible photoassisted room-temperature gas-sensing behavior toward low concentrations of NO 2 gases (0.2-2.5 ppm). By contrast, the pure Sn 2 S 3 thin film exhibited an unapparent room-temperature NO 2 gas-sensing behavior under illumination. The suitable band alignment at the interface of the Sn 2 S 3 -SnO 2 heterostructure thin film and rough surface features might explain the visible photoassisted room-temperature NO 2 gas-sensing responses of the heterostructure thin film on exposure to NO 2 gas at low concentrations in this work.

Method for producing textured substrates for thin-film photovoltaic cells

DOEpatents

Lauf, R.J.

1996-04-02

The invention pertains to the production of ceramic substrates used in the manufacture of thin-film photovoltaic cells used for directly converting solar energy to electrical energy. Elongated ribbon-like sheets of substrate precursor containing a mixture of ceramic particulates, a binder, and a plasticizer are formed and then while green provided with a mechanically textured surface region used for supporting the thin film semiconductor of the photovoltaic cell when the sheets of the substrate precursor are subsequently cut into substrate-sized shapes and then sintered. The textured surface pattern on the substrate provides enhanced light trapping and collection for substantially increasing the, solar energy conversion efficiency of thin-film photovoltaic cells. 4 figs.

Method for producing textured substrates for thin-film photovoltaic cells

DOEpatents

Lauf, R.J.

1994-04-26

The invention pertains to the production of ceramic substrates used in the manufacture of thin-film photovoltaic cells used for directly converting solar energy to electrical energy. Elongated ribbon-like sheets of substrate precursor containing a mixture of ceramic particulates, a binder, and a plasticizer are formed and then while green provided with a mechanically textured surface region used for supporting the thin film semiconductor of the photovoltaic cell when the sheets of the substrate precursor are subsequently cut into substrate-sized shapes and then sintered. The textured surface pattern on the substrate provides enhanced light trapping and collection for substantially increasing the solar energy conversion efficiency of thin-film photovoltaic cells. 4 figures.

Method for producing textured substrates for thin-film photovoltaic cells

DOEpatents

Lauf, Robert J.

1994-01-01

The invention pertains to the production of ceramic substrates used in the manufacture of thin-film photovoltaic cells used for directly converting solar energy to electrical energy. Elongated ribbon-like sheets of substrate precursor containing a mixture of ceramic particulates, a binder, and a plasticizer are formed and then while green provided with a mechanically textured surface region used for supporting the thin film semiconductor of the photovoltaic cell when the sheets of the substrate precursor are subsequently cut into substrate-sized shapes and then sintered. The textured surface pattern on the substrate provides enhanced light trapping and collection for substantially increasing the solar energy conversion efficiency of thin-film photovoltaic cells.

Method for producing textured substrates for thin-film photovoltaic cells

DOEpatents

Lauf, Robert J.

1996-01-01

The invention pertains to the production of ceramic substrates used in the manufacture of thin-film photovoltaic cells used for directly converting solar energy to electrical energy. Elongated ribbon-like sheets of substrate precursor containing a mixture of ceramic particulates, a binder, and a plasticizer are formed and then while green provided with a mechanically textured surface region used for supporting the thin film semiconductor of the photovoltaic cell when the sheets of the substrate precursor are subsequently cut into substrate-sized shapes and then sintered. The textured surface pattern on the substrate provides enhanced light trapping and collection for substantially increasing the, solar energy conversion efficiency of thin-film photovoltaic cells.

Few-Layer MoS2-Organic Thin-Film Hybrid Complementary Inverter Pixel Fabricated on a Glass Substrate.

PubMed

Lee, Hee Sung; Shin, Jae Min; Jeon, Pyo Jin; Lee, Junyeong; Kim, Jin Sung; Hwang, Hyun Chul; Park, Eunyoung; Yoon, Woojin; Ju, Sang-Yong; Im, Seongil

2015-05-13

Few-layer MoS2-organic thin-film hybrid complementary inverters demonstrate a great deal of device performance with a decent voltage gain of ≈12, a few hundred pW power consumption, and 480 Hz switching speed. As fabricated on glass, this hybrid CMOS inverter operates as a light-detecting pixel as well, using a thin MoS2 channel. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Congenital cheek teratoma with temporo-mandibular joint ankylosis managed with ultra-thin silicone sheet interpositional arthroplasty.

PubMed

Bhatnagar, Ankur; Verma, Vinay Kumar; Purohit, Vishal

2013-01-01

Primary cheek teratomas are rare with < 5 reported cases. None had associated temporo mandibular joint ankylosis (TMJA). The fundamental aim in the treatment of TMJA is the successful surgical resection of ankylotic bone, prevention of recurrence, and aesthetic improvement by ensuring functional occlusion. Early treatment is necessary to promote proper growth and function of mandible and to facilitate the positive psychological development of child. Inter-positional arthroplasty with ultra-thin silicone sheet was performed. Advantages include short operative time, less foreign material in the joint space leading to negligible foreign body reactions and least chances of implant extrusion. Instead of excising a large bony segment, a thin silicone sheet was interposed and then sutured ensuring preservation of mandibular height. Aggressive post-operative physiotherapy with custom made dynamic jaw exerciser was used to prevent recurrence.

Intrinsic Dawn-Dusk Asymmetry of Magnetotail Thin Current Sheet

NASA Astrophysics Data System (ADS)

Lu, S.; Pritchett, P. L.; Angelopoulos, V.; Artemyev, A.

2017-12-01

Magnetic reconnection and its related phenomena (flux ropes, dipolarization fronts, bursty bulk flows, particle injections, etc.) occur more frequently on the duskside in the Earth's magnetotail. Magnetohydrodynamic simulations attributed the asymmetry to the nonuniform ionospheric conductance through global scale magnetosphere-ionosphere interaction. Hybrid simulations, on the other hand, found an alternative responsible mechanism: the Hall effect in the magnetotail thin current sheet, but left an open question: What is the physical origin of the asymmetric Hall effect? The answer could be the temperature difference on the two sides and/or the dawn-dusk transportation of magnetic flux and plasmas. In this work, we use 3-D particle-in-cell simulations to further explore the magnetotail dawn-dusk asymmetry. The magnetotail equilibrium contains a dipole magnetic field and a current sheet region. The simulation is driven by a symmetric and localized (in the y direction) high-latitude electric field, under which the current sheet thins with a decrease of Bz. During the same time, a dawn-dusk asymmetry is formed intrinsically in the thin current sheet, with a smaller Bz, a stronger Hall effect (indicated by the Hall electric field Ez), and a stronger cross-tail current jy on the duskside. The deep origin of the asymmetry is also shown to be dominated by the dawnward E×B drift of magnetic flux and plasmas. A direct consequence of this intrinsic dawn-dusk asymmetry is that it favors magnetotail reconnection and related phenomena to preferentially occur on the duskside.

Antimony-Doped Tin Oxide Thin Films Grown by Home Made Spray Pyrolysis Technique

NASA Astrophysics Data System (ADS)

Yusuf, Gbadebo; Babatola, Babatunde Keji; Ishola, Abdulahi Dimeji; Awodugba, Ayodeji O.; Solar cell Collaboration

2016-03-01

Transparent conducting antimony-doped tin oxide (ATO) films have been deposited on glass substrates by home made spray pyrolysis technique. The structural, electrical and optical properties of the ATO films have been investigated as a function of Sb-doping level and annealing temperature. The optimum target composition for high conductivity and low resistivity was found to be 20 wt. % SnSb2 + 90 wt. ATO. Under optimized deposition conditions of 450oC annealing temperature, electrical resistivity of 5.2×10-4 Ω -cm, sheet resistance of 16.4 Ω/sq, average optical transmittance of 86% in the visible range, and average optical band-gap of 3.34eV were obtained. The film deposited at lower annealing temperature shows a relatively rough, loosely bound slightly porous surface morphology while the film deposited at higher annealing temperature shows uniformly distributed grains of greater size. Keywords: Annealing, Doping, Homemade spray pyrolysis, Tin oxide, Resistivity

New continuous recording procedure of holographic information on transient phenomena

NASA Astrophysics Data System (ADS)

Nagayama, Kunihito; Nishihara, H. Keith; Murakami, Terutoshi

1992-09-01

A new method for continuous recording of holographic information, 'streak holography,' is proposed. This kind of record can be useful for velocity and acceleration measurement as well as for observing a moving object whose trajectory cannot be predicted in advance. A very high speed camera system has been designed and constructed for streak holography. A ring-shaped 100-mm-diam film has been cut out from the high-resolution sheet film and mounted on a thin duralmin disk, which has been driven to rotate directly by an air-turbine spindle. Attainable streak velocity is 0.3 mm/microsecond(s) . A direct film drive mechanism makes it possible to use a relay lens system of extremely small f number. The feasibility of the camera system has been demonstrated by observing several transient events, such as the forced oscillation of a wire and the free fall of small glass particles, using an argon-ion laser as a light source.

Carbon protrusions on PTFE surface prepared by ion irradiation and chemical defluorination

NASA Astrophysics Data System (ADS)

Kobayashi, T.; Iwaki, M.

2006-01-01

A surface of PTFE was covered with small protrusions by ion-beam irradiation. In this study, we converted PTFE protrusions into carbon protrusions by a defluorination (carbonization) process using sodium vapor. The morphology, composition and structure were analyzed by SEM-EDX, Raman spectroscopy and TEM. The irradiated PTFE sheets were packed in evacuated glass tubes with a sodium block and kept at 473 K for 2-48 h. The samples were then rinsed in HCl and distilled water to remove NaF precipitates. The EDX measurement showed that the NaF precipitates were completely removed by washing, and the percentage of carbon atoms was controlled from 60% to 99% by the treatment. Raman spectra showed that graphite structures grow during the defluorination process. TEM micrographs showed that the protrusions have a bubble structure and are covered with a thin wall. The carbonized protrusions were conductive and grew perpendicular to the substrate.

Lightweight Solar Paddle with High Specific Power of 150 W/Kg

NASA Astrophysics Data System (ADS)

Shimazaki, Kazunori; Takahashi, Masato; Imaizumi, Mitsuru; Takamoto, Tatsuya; Ito, Takehiko; Nozaki, Yukishige; Kusawake, Hiroaki

2014-08-01

A lightweight solar paddle using space solar sheet (SSS) is currently being developed, which uses glass-type SSS (G-SSS) comprising InGaP/GaAs/InGaAs triple- junction high-efficiency thin-film solar cells. To avoid damage to the G-SSS due to vibration during launch, we adopted a new architecture on a panel. This panel employed a curved frame-type structure, on which the G-SSS is mounted and test models were manufactured to evaluate the vibration tolerance. The dimensions of the 1.0-cm-thick unit panel were about 1.0 × 1.0 m. Acoustic and sine vibration tests were performed on the model and the results demonstrated the high durability of the curved panel in an acoustic and vibration environments. The specific power of the solar paddle using the curved panel is estimated at approximately 150 W/kg at an array power of about 10 kW.

Investigation of transition States in bulk and freestanding film polymer glasses.

PubMed

Jain, Tushar S; de Pablo, Juan J

2004-04-16

We have performed transition state searches on the potential energy landscape for bulk and freestanding film polymer glasses and identified connected minima. An analysis of the displacements between minima shows that the sites that undergo the greatest displacement are highly localized in space for both the bulk and the thin-film systems studied. In the case of the thin film, the clusters originate at the surface and penetrate into the center of the film thereby coupling the relaxation in the center of the film to the mobile surface layer. Furthermore, the energy barriers between minima are lower in the thin film than in the bulk system. These findings can rationalize the experimentally observed depression of the glass transition temperature in freestanding polymer films.

Optical, Electrical, and Crystal Properties of TiO2 Thin Films Grown by Atomic Layer Deposition on Silicon and Glass Substrates

NASA Astrophysics Data System (ADS)

Kupa, I.; Unal, Y.; Cetin, S. S.; Durna, L.; Topalli, K.; Okyay, A. K.; Ates, H.

2018-05-01

TiO2 thin films have been deposited on glass and Si(100) by atomic layer deposition (ALD) technique using tetrakis(diethylamido)titanium(IV) and water vapor as reactants. Thorough investigation of the properties of the TiO2/glass and TiO2/Si thin films was carried out, varying the deposition temperature in the range from 100°C to 250°C while keeping the number of reaction cycles fixed at 1000. Physical and material property analyses were performed to investigate optical and electrical properties, composition, structure, and morphology. TiO2 films grown by ALD may represent promising materials for future applications in optoelectronic devices.

Antisite disorder induced spin glass and exchange bias effect in Nd2NiMnO6 epitaxial thin film

NASA Astrophysics Data System (ADS)

Singh, Amit Kumar; Chauhan, Samta; Chandra, Ramesh

2017-03-01

We report the observation of the exchange bias effect and spin glass behaviour at low temperature in a ferromagnetic Nd2NiMnO6 epitaxial thin film. Along with the ferromagnetic transition at ˜194 K, an additional transition is observed at lower temperature (˜55 K) as seen from M-T curves of the sample. A shift in the ac susceptibility peak with frequency has been observed at low temperature, which is a signature of a glassy phase within the sample. The detailed investigation of the memory effect and time dependent magnetic relaxation measurements reveals the presence of a spin glass phase in the Nd2NiMnO6 thin film. The exchange bias effect observed at low temperature in the sample has been associated with an antisite disorder induced spin glass phase, which results in a ferromagnetic/spin glass interface at low temperature. The exchange bias behaviour has been further confirmed by performing cooling field and temperature dependence of exchange bias along with training effect measurements.

Improved conductivity of indium-tin-oxide film through the introduction of intermediate layer

NASA Astrophysics Data System (ADS)

Ng, S. W.; Yam, F. K.; Beh, K. P.; Tneh, S. S.; Hassan, Z.

2016-09-01

A thin intermediate layer (Ag, AuSn, In, Ni, Sn, SiO2) was individually deposited on glass substrates prior to the deposition of indium-tin-oxide (ITO) thin film by radio-frequency (RF) magnetron sputtering employing ITO target (composition ratio of In2O3:SnO2 = 9:1). The structural, optical and electrical properties were investigated to compare the ITO thin film with and without an intermediate layer. The preferential orientation of all ITO films was along (222) plane. Although all thin films were polycrystalline, the presence of intermediate layer promoted the overall crystallinity. The sheet resistance and resistivity of the ITO film were reduced from ∼68 Ω/□ to ∼29-45 Ω/□, and 16.2 × 10-4 Ω cm up to 7.58 × 10-4 Ω cm, respectively, by inserting a thin metal layer underneath the ITO film, and it is dependent on the degree of crystallization. The optical transmittance in the visible region varies from 40 to 88% for different samples. Based on the evaluation from Tauc plot, the optical band gap falls in the range of 4.02-4.12 eV. Physical film thickness was compared with that evaluated by optical measurement in the visible range and the physical thickness was found to be smaller. Similarly, the carrier concentration/scattering time from Hall effect measurement were also compared with that from optical measurement in the infrared region. Haacke's figure of merit (FOM) was employed to assess the quality of the ITO films, and the highest FOM is credited to ITO/In up to ∼8 × 10-3 Ω-1 in the visible light region.

The Work Softening by Deformation-Induced Disordering and Cold Rolling of 6.5 wt pct Si Steel Thin Sheets

NASA Astrophysics Data System (ADS)

Wang, Xianglong; Li, Haoze; Zhang, Weina; Liu, Zhenyu; Wang, Guodong; Luo, Zhonghan; Zhang, Fengquan

2016-09-01

As-cast strip of 6.5 wt pct Si steel was fabricated by twin-roll strip casting. After hot rolling at 1323 K (1050 °C), thin sheets with the thickness of 0.35 mm were produced by warm rolling at 373 K (100 °C) with rolling reductions of 15, 25, 35, 45, 55, and 65 pct. Influence of warm rolling reduction on ductility was investigated by room temperature bending test. The measurement of macro-hardness showed that "work softening" could begin when the warm rolling reduction exceeded 35 pct. The room temperature ductility of the thin sheets gradually increased with the increase of warm rolling reductions, and the plastic deformation during bending began to form when the warm rolling reduction was greater than 45 pct, the 65 pct rolled thin sheet exhibited the maximum plastic deformation of about 0.6 pct during bending at room temperature, with a few small dimples having been observed on the fracture surfaces. B2-ordered domains were formed in the 15, 25, 35, 45, and 55 pct rolled specimens, and their average size decreased with the increase of warm rolling reductions. By contrast, no B2-ordered domain could be found in the 65 pct rolled specimen. It had been observed that large-ordered domains could be split into several small parts by the slip of partial super-dislocations during warm rolling, which led to significant decrease of the order degree to cause the phenomenon of deformation-induced disordering. On the basis of these results, cold rolling schedule was developed to successfully fabricate 0.25-mm-thick sheets with good surface qualities and magnetic properties from warm rolled sheets.

An energy landscape based approach for studying supercooled liquid and glassy thin films

NASA Astrophysics Data System (ADS)

Shah, Pooja; Mittal, Jeetain; Truskett, Thomas M.

2004-03-01

Materials in confined spaces are important in science and technology. Examples include biological fluids in membranes, liquids trapped in porous rocks, and thin-film materials used in high-resolution patterning technologies. However, few reliable rules exist to predict how the properties of materials will be affected by thin-film confinement. We have recently shown that the potential energy landscape formalism can be used to study, by both theory [1] and simulation [2], how the behavior of thin-film materials depends on sample dimensions and film-substrate interactions. Our landscape-based mean-field theory [1] can be used to study both the thermodynamic properties and the ideal glass transition of thin films. It predicts that, in the case of neutral or repulsive walls, the ideal glass transition temperature is lowered by decreasing film thickness. This is in qualitative agreement with experimental trends for the kinetic glass transition in confined fluids. Landscape-based approaches are also valuable for understanding the structural and mechanical properties of thin-film glasses. We demonstrate how the concept of an "equation of state of the energy landscape" [3] can be generalized to thin films [1, 2], where it gives insights into potential molecular mechanisms of tensile strength. [1] T. M. Truskett and V. Ganesan, J. Chem. Phys. 119, 1897-1900(2003); J. Mittal, P. Shah and T. M. Truskett, to be submitted to Langmuir. [2] P. Shah and T. M. Truskett, to be submitted to J. Phys. Chem. B. [3] S. Sastry, P. G. Debenedetti and F. H. Stillinger, Phys. Rev. E 56, 5533 (1997)

Nonlinear evolution of three-dimensional instabilities of thin and thick electron scale current sheets: Plasmoid formation and current filamentation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jain, Neeraj; Büchner, Jörg; Max Planck Institute for Solar System Research, Justus-Von-Liebig-Weg-3, Göttingen

Nonlinear evolution of three dimensional electron shear flow instabilities of an electron current sheet (ECS) is studied using electron-magnetohydrodynamic simulations. The dependence of the evolution on current sheet thickness is examined. For thin current sheets (half thickness =d{sub e}=c/ω{sub pe}), tearing mode instability dominates. In its nonlinear evolution, it leads to the formation of oblique current channels. Magnetic field lines form 3-D magnetic spirals. Even in the absence of initial guide field, the out-of-reconnection-plane magnetic field generated by the tearing instability itself may play the role of guide field in the growth of secondary finite-guide-field instabilities. For thicker current sheetsmore » (half thickness ∼5 d{sub e}), both tearing and non-tearing modes grow. Due to the non-tearing mode, current sheet becomes corrugated in the beginning of the evolution. In this case, tearing mode lets the magnetic field reconnect in the corrugated ECS. Later thick ECS develops filamentary structures and turbulence in which reconnection occurs. This evolution of thick ECS provides an example of reconnection in self-generated turbulence. The power spectra for both the thin and thick current sheets are anisotropic with respect to the electron flow direction. The cascade towards shorter scales occurs preferentially in the direction perpendicular to the electron flow.« less

46 CFR 164.009-3 - Noncombustible materials not requiring specific approval.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Merchant Vessels § 164.009-3 Noncombustible materials not requiring specific approval. The following noncombustible materials may be used in merchant vessel construction though not specifically approved under this subpart: (a) Sheet glass, block glass, clay, ceramics, and uncoated fibers. (b) All metals, except...

Characterisation of weld zone reactions in dissimilar glass-to-aluminium pulsed picosecond laser welds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ciuca, Octav P., E-mail: octav.ciuca@manchester.ac

Precision welded joints, produced between fused silica glass and aluminium by a newly-developed picosecond-pulse laser technique, have been analysed for the first time using a full range of electron microscopy methods. The welds were produced as lap joints by focusing a 1.2 μm diameter laser beam through the transparent glass top sheet, slightly below the surface of the metal bottom sheet. Despite the extremely short interaction time, extensive reaction was observed in the weld zone, which involved the formation of nanocrystalline silicon and at least two transitional alumina phases, γ- and δ-Al{sub 2}O{sub 3}. The weld formation process was foundmore » to be complex and involved: the formation of a constrained plasma cavity at the joint interface, non-linear absorption in the glass, and the creation of multiple secondary keyholes in the metal substrate by beam scattering. The joint area was found to expand outside of the main interaction volume, as the energy absorbed into the low conductivity and higher melting point silica glass sheet melted the aluminium surface across a wider contact area. The reasons for the appearance of nanocrystalline Si and transitional alumina reaction products within the welds are discussed. - Highlights: •Pulsed laser welding of dissimilar materials causes extensive chemical reactivity. •Metastable Al{sub 2}O{sub 3} phases form due to laser-induced highly-transient thermal regime. •Fused silica is reduced by Al to form nanocrystalline Si. •Mechanism of joint formation is discussed.« less

46 CFR 160.005-4 - Construction.

Code of Federal Regulations, 2010 CFR

2010-10-01

...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Life Preservers, Fibrous Glass, Adult and Child (Jacket Type.... 160.005-1, Sheet 1, for adult size, and Sheet 4, for child size, joined by seams and stitching as shown on the drawing. A drawstring tunnel shall be formed by stitching a strip of the tunnel strip...

Effect of shear stress on platelet adhesion to expanded polytetrafluoroethylene, a silicone sheet, and an endothelial cell monolayer.

PubMed

Furukawa, K S; Ushida, T; Sugano, H; Tamaki, T; Ohshima, N; Tateishi, T

2000-01-01

We visualized in real-time platelets adhering to the surface of three representative biomaterials, by using an apparatus consisting of a modified cone and plate rheometer combined with an upright epifluorescence microscope under two shear flows (0.1 and 5.0 dyne/cm2). The materials were expanded polytetrafluoroethylene (ePTFE), silicone sheet, and a monolayer of bovine endothelial cells (ECs) formed on glass, all of which are opaque materials used for artificial blood vessels and medical devices. According to quantitative analysis, the monolayer of ECs formed on glass had better blood compatibility than did either the ePTFE or the silicone sheet under shear flow conditions. Under a shear flow condition of 0.1 dyne/cm2, platelet adhesion was silicone sheet > ePTFE. In contrast, under a shear flow condition of 5.0 dyne/cm2, ePTFE > silicone sheet. These results indicate that the intensity of shear stress could modify the order of hemocompatibility of the materials. Therefore, direct observation of platelet adhesion under shear flow conditions is indispensable for testing and screening biomaterials and for providing a precise quantitative evaluation of platelet adhesion.

Silicon on ceramic process. Silicon sheet growth development for the large-area silicon sheet task of the low-cost silicon solar array project

NASA Technical Reports Server (NTRS)

Zook, J. D.; Heaps, J. D.; Maciolek, R. B.; Koepke, B. G.; Butter, C. D.; Schuldt, S. B.

1977-01-01

The technical and economic feasibility of producing solar-cell-quality sheet silicon was investigated. The sheets were made by coating one surface of carbonized ceramic substrates with a thin layer of large-grain polycrystalline silicon from the melt. Significant progress was made in all areas of the program.

Effects of transverse temperature field nonuniformity on stress in silicon sheet growth

NASA Technical Reports Server (NTRS)

Mataga, P. A.; Hutchinson, J. W.; Chalmers, B.; Bell, R. O.; Kalejs, J. P.

1987-01-01

Stress and strain rate distributions are calculated using finite element analysis for steady-state growth of thin silicon sheet temperature nonuniformities imposed in the transverse (sheet width) dimension. Significant reductions in residual stress are predicted to occur for the case where the sheet edge is cooled relative to its center provided plastic deformation with high creep rates is present.

Synthesis and Characterization of High Energy Sheet Materials Based on HMX / RDX and Hydroxyl Terminated Polybutadiene

NASA Astrophysics Data System (ADS)

Elsharkawy, Karim; Guo, Lin; Taha, Elhussein; Fouda, Hany

2017-07-01

In this paper three types of thin sheets of highly energetic materials were prepared and characterized. The first based on 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX). The second type based on 1,3,5-trinitro-1,3,5-triazinane (RDX). Both types contain polyurethane (PU), formulated by hydroxyl terminated polybutadiene (HTPB) and Isophorondiisocyanate (IPDI). The third type based on (RDX) and polyisoprene (PI) as high elastomeric material. The first and second types of thin sheets were prepared by applying the casting technique while the third type was prepared by slurry technique then followed by rolling of the prepared beads of the RDX coated by PI. These high energy sheet materials were cured in oven at 60°C. The measured explosive properties of the prepared sheets were discussed and showed that the sensitivity to impact and friction of the prepared sheets explosives materials were markedly decreased when compared to pure HMX or pure RDX, but the sensitivity to heat was close to that of pure RDX. In spite of the markedly decrease in the sensitivity of these sheets, the explosive characteristics were nearly not affected the sheets have very good stress-strain values.

Electromagnetic augmentation for casting of thin metal sheets

DOEpatents

Hull, John R.

1989-01-01

Thin metal sheets are cast by magnetically levitating molten metal deposited in a mold within a ferromagnetic yoke and between AC conducting coils and linearly displacing the magnetically levitated liquid metal while it is being cooled by the water-cooled walls of the mold to form a solid metal sheet. A conducting shield is electrically coupled to the molten metal sheet to provide a return path for eddy currents induced in the metal sheet by the current in the AC conducting coils. In another embodiment, a DC conducting coil is coupled to the metal sheet for providing a direct current therein which interacts with the magnetic field to levitate the moving metal sheet. Levitation of the metal sheet in both molten and solid forms reduces its contact pressure with the mold walls while maintaining sufficient engagement therebetween to permit efficient conductive cooling by the mold through which a coolant fluid may be circulated. The magnetic fields associated with the currents in the aforementioned coils levitate the molten metal sheet while the mold provides for its lateral and vertical confinement. A leader sheet having electromagnetic characteristics similar to those of the molten metal sheet is used to start the casing process and precedes the molten metal sheet through the yoke/coil arrangement and mold and forms a continuous sheet therewith. The yoke/coil arrangement may be either U-shaped with a single racetrack coil or may be rectangular with a pair of spaced, facing bedstead coils.

Elemental analysis of forensic glasses by inductively coupled plasma mass spectrometry

NASA Astrophysics Data System (ADS)

Almirall, Jose R.; Duckworth, Douglas C.; Bayne, Charles K.; Morton, Sherman A.; Smith, David H.; Koons, Robert D.; Furton, Kenneth G.

1999-02-01

Flat glass is a common type of evidence collected from the scenes of crimes such as burglaries, vandalism, and hit-and- run accidents. The usefulness of such evidence lies in the ability to associate the glass from the scene (or a suspect) to the original source. Physical and chemical analysis of the glass can be used for discrimination between the possible sources of glass. If the sample is large enough, physical attributes such as fracture matches, density, color, and thickness can be employed for comparison between a recovered fragment(s) to the suspect source. More commonly, refractive index (RI) comparisons are employed. Due to the improved control over glass manufacturing processes, RI values often cannot differentiate glasses where approximately 6 - 9% of casework samples are not expected to be distinguished by RI alone even if they originated from different sources. Employing methods such as NAA, XRF, ICP-AES, and ICP-MS for the comparison of trace elemental compositions has been shown to be more discriminating than RI comparisons. The multielement capability and the sensitivity of ICP-AES and ICP-MS provide for excellent discrimination power. In this work, the sources of variability in ICP-MS of glass analysis are investigated to determine possible sources of variation. The sources of variation examined include errors due to sample preparation, instrument accuracy and precision, and interlaboratory reproducibility. Other sources of variation include inhomogeneity across a sheet of glass from the same source. Analysis of variance has been applied to our ICP-MS analysis of NIST standards and to the interlaboratory comparisons of float glass samples collected across a sheet in a production facility. The results of these experiments allows for a more accurate interpretation of forensic glass data and a better understanding of the discriminating power (absolute and practical) of ICP-MS.

AZO nanorods thin films by sputtering method

NASA Astrophysics Data System (ADS)

Rosli, A. B.; Shariffudin, S. S.; Awang, Z.; Herman, S. H.

2018-05-01

Al-doped zinc oxide (AZO) nanorods thin film were deposited on Au catalyst using RF sputtering at 300 °C. The 15 nm thickness Au catalyst were deposited on glass substrates by sputtering method followed by annealing for 15 min at 500 °C to form Au nanostructures on the glass substrate. The AZO thin films were then deposited on Au catalyst at different RF power ranging from 50 - 200 W. The morphology of AZO was characterized using Field Emission Scanning Electron Microscopy while X-ray Diffraction was used to examine crystallinity of AZO thin films. From this work, the AZO nanorods was found grow at 200 W RF power.

Triple-glazed insulating unit with improved edge insulation

DOEpatents

Goodwin, George B.; Buchanan, Michael J.

2016-06-07

An insulating unit includes a first spacer frame between first and second sheets, e.g. glass sheets, and a second spacer frame between the second sheet and a third sheet. A first surface of the first spacer frame is adhered to inner surface of the first sheet, and an opposite second surface of the first spacer frame is adhered to a first surface of the second sheet, by a moisture impervious adhesive layer. A first outer surface of the second spacer frame is adhered to a second surface of the second sheet, and an opposite second outer surface of the second spacer frame is adhered to an inner surface of the third sheet, by the adhesive layer. The first spacer frame and the second spacer frame have an offset of greater than zero.

Method and apparatus for determining weldability of thin sheet metal

DOEpatents

Goodwin, Gene M.; Hudson, Joseph D.

1988-01-01

A fixture is provided for testing thin sheet metal specimens to evaluate hot-cracking sensitivity for determining metal weldability on a heat-to-heat basis or through varying welding parameters. A test specimen is stressed in a first direction with a load selectively adjustable over a wide range and then a weldment is passed along over the specimen in a direction transverse to the direction of strain to evaluate the hot-cracking characteristics of the sheet metal which are indicative of the weldability of the metal. The fixture provides evaluations of hot-cracking sensitivity for determining metal weldability in a highly reproducible manner with minimum human error.

Method of preparing thin porous sheets of ceramic material

DOEpatents

Swarr, Thomas E.; Nickols, Richard C.; Krasij, Myron

1987-03-24

A method of forming thin porous sheets of ceramic material for use as electrodes or other components in a molten carbonate fuel cell is disclosed. The method involves spray drying a slurry of fine ceramic particles in liquid carrier to produce generally spherical agglomerates of high porosity and a rough surface texture. The ceramic particles may include the electrode catalyst and the agglomerates can be calcined to improve mechanical strength. After slurrying with suitable volatile material and binder tape casting is used to form sheets that are sufficiently strong for further processing and handling in the assembly of a high temperature fuel cell.

Surface vertical magnetic field produced by a finite loop buried in an earth containing a thin conducting sheet

NASA Astrophysics Data System (ADS)

Durkin, John

1997-01-01

The effect of a thin conducting sheet located at the earth-to-air interface on the surface vertical magnetic field created by a buried finite loop was studied. Expected field values as a function of frequency are provided for variations in the sheet's conductivity-thickness product. Since the results would be most beneficial for purposes of through-the-earth communications, such as communicating with trapped miners following a mine emergency, field values were derived for a range of frequencies, mine depths, and earth conductivity values that would be typically found in such an application.

Optical Forging of Graphene into Three-Dimensional Shapes.

PubMed

Johansson, Andreas; Myllyperkiö, Pasi; Koskinen, Pekka; Aumanen, Jukka; Koivistoinen, Juha; Tsai, Hung-Chieh; Chen, Chia-Hao; Chang, Lo-Yueh; Hiltunen, Vesa-Matti; Manninen, Jyrki J; Woon, Wei Yen; Pettersson, Mika

2017-10-11

Atomically thin materials, such as graphene, are the ultimate building blocks for nanoscale devices. But although their synthesis and handling today are routine, all efforts thus far have been restricted to flat natural geometries, since the means to control their three-dimensional (3D) morphology has remained elusive. Here we show that, just as a blacksmith uses a hammer to forge a metal sheet into 3D shapes, a pulsed laser beam can forge a graphene sheet into controlled 3D shapes in the nanoscale. The forging mechanism is based on laser-induced local expansion of graphene, as confirmed by computer simulations using thin sheet elasticity theory.

Method of preparing thin porous sheets of ceramic material

DOEpatents

Swarr, T.E.; Nickols, R.C.; Krasij, M.

1984-05-23

A method of forming thin porous sheets of ceramic material for use as electrodes or other components in a molten carbonate fuel cell is disclosed. The method involves spray drying a slurry of fine ceramic particles in liquid carrier to produce generally spherical agglomerates of high porosity and a rough surface texture. The ceramic particles may include the electrode catalyst and the agglomerates can be calcined to improve mechanical strength. After slurrying with suitable volatile material and binder tape casting is used to form sheets that are sufficiently strong for further processing and handling in the assembly of a high temperature fuel cell.

Pair distribution functions of amorphous organic thin films from synchrotron X-ray scattering in transmission mode

DOE PAGES

Shi, Chenyang; Teerakapibal, Rattavut; Yu, Lian; ...

2017-07-10

Using high-brilliance high-energy synchrotron X-ray radiation, for the first time the total scattering of a thin organic glass film deposited on a strongly scattering inorganic substrate has been measured in transmission mode. The organic thin film was composed of the weakly scattering pharmaceutical substance indomethacin in the amorphous state. The film was 130 µm thick atop a borosilicate glass substrate of equal thickness. The atomic pair distribution function derived from the thin-film measurement is in excellent agreement with that from bulk measurements. This ability to measure the total scattering of amorphous organic thin films in transmission will enable accurate in situmore » structural studies for a wide range of materials.« less

Pair distribution functions of amorphous organic thin films from synchrotron X-ray scattering in transmission mode

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shi, Chenyang; Teerakapibal, Rattavut; Yu, Lian

2017-07-10

Using high-brilliance high-energy synchrotron X-ray radiation, for the first time the total scattering of a thin organic glass film deposited on a strongly scattering inorganic substrate has been measured in transmission mode. The organic thin film was composed of the weakly scattering pharmaceutical substance indomethacin in the amorphous state. The film was 130 µm thick atop a borosilicate glass substrate of equal thickness. The atomic pair distribution function derived from the thin-film measurement is in excellent agreement with that from bulk measurements. This ability to measure the total scattering of amorphous organic thin films in transmission will enable accuratein situstructuralmore » studies for a wide range of materials.« less

Spray-Deposited Large-Area Copper Nanowire Transparent Conductive Electrodes and Their Uses for Touch Screen Applications.

PubMed

Chu, Hsun-Chen; Chang, Yen-Chen; Lin, Yow; Chang, Shu-Hao; Chang, Wei-Chung; Li, Guo-An; Tuan, Hsing-Yu

2016-05-25

Large-area conducting transparent conducting electrodes (TCEs) were prepared by a fast, scalable, and low-cost spray deposition of copper nanowire (CuNW) dispersions. Thin, long, and pure copper nanowires were obtained via the seed-mediated growth in an organic solvent-based synthesis. The mean length and diameter of nanowires are, respectively, 37.7 μm and 46 nm, corresponding to a high-mean-aspect ratio of 790. These wires were spray-deposited onto a glass substrate to form a nanowire conducting network which function as a TCE. CuNW TCEs exhibit high-transparency and high-conductivity since their relatively long lengths are advantageous in lowering in the sheet resistance. For example, a 2 × 2 cm(2) transparent nanowire electrode exhibits transmittance of T = 90% with a sheet resistance as low as 52.7 Ω sq(-1). Large-area sizes (>50 cm(2)) of CuNW TCEs were also prepared by the spray coating method and assembled as resistive touch screens that can be integrated with a variety of devices, including LED lighting array, a computer, electric motors, and audio electronic devices, showing the capability to make diverse sizes and functionalities of CuNW TCEs by the reported method.

Roll-to-roll slot-die coating of 400 mm wide, flexible, transparent Ag nanowire films for flexible touch screen panels

PubMed Central

Kim, Dong-Ju; Shin, Hae-In; Ko, Eun-Hye; Kim, Ki-Hyun; Kim, Tae-Woong; Kim, Han-Ki

2016-01-01

We report fabrication of large area Ag nanowire (NW) film coated using a continuous roll-to-roll (RTR) slot die coater as a viable alternative to conventional ITO electrodes for cost-effective and large-area flexible touch screen panels (TSPs). By controlling the flow rate of shear-thinning Ag NW ink in the slot die, we fabricated Ag NW percolating network films with different sheet resistances (30–70 Ohm/square), optical transmittance values (89–90%), and haze (0.5–1%) percentages. Outer/inner bending, twisting, and rolling tests as well as dynamic fatigue tests demonstrated that the mechanical flexibility of the slot-die coated Ag NW films was superior to that of conventional ITO films. Using diamond-shape patterned Ag NW layer electrodes (50 Ohm/square, 90% optical transmittance), we fabricated 12-inch flexible film-film type and rigid glass-film-film type TSPs. Successful operation of flexible TSPs with Ag NW electrodes indicates that slot-die-coated large-area Ag NW films are promising low cost, high performance, and flexible transparent electrodes for cost-effective large-area flexible TSPs and can be substituted for ITO films, which have high sheet resistance and are brittle. PMID:27677410

Roll-to-roll slot-die coating of 400 mm wide, flexible, transparent Ag nanowire films for flexible touch screen panels.

PubMed

Kim, Dong-Ju; Shin, Hae-In; Ko, Eun-Hye; Kim, Ki-Hyun; Kim, Tae-Woong; Kim, Han-Ki

2016-09-28

We report fabrication of large area Ag nanowire (NW) film coated using a continuous roll-to-roll (RTR) slot die coater as a viable alternative to conventional ITO electrodes for cost-effective and large-area flexible touch screen panels (TSPs). By controlling the flow rate of shear-thinning Ag NW ink in the slot die, we fabricated Ag NW percolating network films with different sheet resistances (30-70 Ohm/square), optical transmittance values (89-90%), and haze (0.5-1%) percentages. Outer/inner bending, twisting, and rolling tests as well as dynamic fatigue tests demonstrated that the mechanical flexibility of the slot-die coated Ag NW films was superior to that of conventional ITO films. Using diamond-shape patterned Ag NW layer electrodes (50 Ohm/square, 90% optical transmittance), we fabricated 12-inch flexible film-film type and rigid glass-film-film type TSPs. Successful operation of flexible TSPs with Ag NW electrodes indicates that slot-die-coated large-area Ag NW films are promising low cost, high performance, and flexible transparent electrodes for cost-effective large-area flexible TSPs and can be substituted for ITO films, which have high sheet resistance and are brittle.

Roll-to-roll slot-die coating of 400 mm wide, flexible, transparent Ag nanowire films for flexible touch screen panels

NASA Astrophysics Data System (ADS)

Kim, Dong-Ju; Shin, Hae-In; Ko, Eun-Hye; Kim, Ki-Hyun; Kim, Tae-Woong; Kim, Han-Ki

2016-09-01

We report fabrication of large area Ag nanowire (NW) film coated using a continuous roll-to-roll (RTR) slot die coater as a viable alternative to conventional ITO electrodes for cost-effective and large-area flexible touch screen panels (TSPs). By controlling the flow rate of shear-thinning Ag NW ink in the slot die, we fabricated Ag NW percolating network films with different sheet resistances (30-70 Ohm/square), optical transmittance values (89-90%), and haze (0.5-1%) percentages. Outer/inner bending, twisting, and rolling tests as well as dynamic fatigue tests demonstrated that the mechanical flexibility of the slot-die coated Ag NW films was superior to that of conventional ITO films. Using diamond-shape patterned Ag NW layer electrodes (50 Ohm/square, 90% optical transmittance), we fabricated 12-inch flexible film-film type and rigid glass-film-film type TSPs. Successful operation of flexible TSPs with Ag NW electrodes indicates that slot-die-coated large-area Ag NW films are promising low cost, high performance, and flexible transparent electrodes for cost-effective large-area flexible TSPs and can be substituted for ITO films, which have high sheet resistance and are brittle.

Investigation of the Structural, Electrical, and Optical Properties of the Nano-Scale GZO Thin Films on Glass and Flexible Polyimide Substrates

PubMed Central

Wang, Fang-Hsing; Chen, Kun-Neng; Hsu, Chao-Ming; Liu, Min-Chu; Yang, Cheng-Fu

2016-01-01

In this study, Ga2O3-doped ZnO (GZO) thin films were deposited on glass and flexible polyimide (PI) substrates at room temperature (300 K), 373 K, and 473 K by the radio frequency (RF) magnetron sputtering method. After finding the deposition rate, all the GZO thin films with a nano-scale thickness of about 150 ± 10 nm were controlled by the deposition time. X-ray diffraction patterns indicated that the GZO thin films were not amorphous and all exhibited the (002) peak, and field emission scanning electron microscopy showed that only nano-scale particles were observed. The dependences of the structural, electrical, and optical properties of the GZO thin films on different deposition temperatures and substrates were investigated. X-ray photoemission spectroscopy (XPS) was used to measure the elemental composition at the chemical and electronic states of the GZO thin films deposited on different substrates, which could be used to clarify the mechanism of difference in electrical properties of the GZO thin films. In this study, the XPS binding energy spectra of Ga2p3/2 and Ga2p1/2 peaks, Zn2p3/2 and Zn2p1/2 peaks, the Ga3d peak, and O1s peaks for GZO thin films on glass and PI substrates were well compared. PMID:28335216

In situ electric properties of Ag films deposited on rough substrates

NASA Astrophysics Data System (ADS)

Zhou, Hong; Yu, Sen-Jiang; Zhang, Yong-Ju; Chen, Miao-Gen; Jiao, Zhi-Wei; Si, Ping-Zhan

2013-01-01

Silver (Ag) films have been deposited on rough substrates (including frosted glass and silicone grease), and for comparison on flat glass, by DC-magnetron sputtering, and their sheet resistances measured in situ during deposition. It is found that the growth of Ag films proceeds through three distinct stages: discontinuous, semi-continuous, and continuous regimes. The sheet resistance on rough substrates jumps in the vicinity of the percolation threshold, whereas the resistance on flat substrates decreases monotonically during deposition. The abnormal in situ electric properties on rough substrates are well explained based on the differences of the growth mechanism and microstructure of Ag films on different substrates.

Optical residual stress measurement in TFT-LCD panels

NASA Astrophysics Data System (ADS)

Wang, Wei-Chung; Sung, Po-Chi

2017-06-01

The residual stress of the glass substrate might be one of causes to produce the non-uniform light distribution defect, i.e. Mura, in thin film transistor-liquid crystal display (TFT-LCD) panels. Glass is a birefringent material with very low birefringence. Furthermore, the thinner and thinner thickness request from the market makes the traditional photoelasticity almost impossible to measure the residual stresses produced in thin glass plates. Recently, a low-level stress measurement method called transmissivity extremities theory of photoelasticity (TEToP) was successfully developed to measure the residual stress in glass plate. Besides, to measure the stress of the glass plate in the TFT-LCD panel whose rear surface may has different kinds of coatings, an advanced reflection photoelasticity was also developed. In this paper, three commercially available glass plates with 0.33mm nominal thickness and three glass circular disks with different coatings were inspected to verify the feasibility of the TEToP and the advanced reflection photoelasticity, respectively.

Characterization of the strain-life fatigue properties of thin sheet metal using an optical extensometer

NASA Astrophysics Data System (ADS)

Zhang, Shuiqiang; Mao, Shuangshuang; Arola, Dwayne; Zhang, Dongsheng

2014-09-01

Characterizing the strain-life fatigue behavior of thin sheet metals is often challenging since the required specimens have short gauge lengths to avoid buckling, thereby preventing the use of conventional mechanical extensometers. To overcome this obstacle a microscopic optical imaging system has been developed to measure the strain amplitude during fatigue testing using Digital Image Correlation (DIC). A strategy for rapidly recording images is utilized to enable sequential image sampling rates of at least 10 frames per second (fps) using a general digital camera. An example of a complete strain-life fatigue test for thin sheet steel under constant displacement control is presented in which the corresponding strain within the gage section of the specimen is measured using the proposed imaging system. The precision in strain measurement is assessed and methods for improving the image sampling rates in dynamic testing are discussed.

Congenital cheek teratoma with temporo-mandibular joint ankylosis managed with ultra-thin silicone sheet interpositional arthroplasty

PubMed Central

Bhatnagar, Ankur; Verma, Vinay Kumar; Purohit, Vishal

2013-01-01

Primary cheek teratomas are rare with < 5 reported cases. None had associated temporo mandibular joint ankylosis (TMJA). The fundamental aim in the treatment of TMJA is the successful surgical resection of ankylotic bone, prevention of recurrence, and aesthetic improvement by ensuring functional occlusion. Early treatment is necessary to promote proper growth and function of mandible and to facilitate the positive psychological development of child. Inter-positional arthroplasty with ultra-thin silicone sheet was performed. Advantages include short operative time, less foreign material in the joint space leading to negligible foreign body reactions and least chances of implant extrusion. Instead of excising a large bony segment, a thin silicone sheet was interposed and then sutured ensuring preservation of mandibular height. Aggressive post-operative physiotherapy with custom made dynamic jaw exerciser was used to prevent recurrence. PMID:24163567

Formability behavior studies on CP-Al sheets processed through the helical tool path of incremental forming process

NASA Astrophysics Data System (ADS)

Markanday, H.; Nagarajan, D.

2018-02-01

Incremental sheet forming (ISF) is a novel die-less sheet metal forming process, which can produce components directly from the CAD geometry using a CNC milling machine at less production time and cost. The formability of the sheet material used is greatly affected by the process parameters involved and tool path adopted, and the present study is aimed to investigate the influence of different process parameter values using the helical tool path strategy on the formability of a commercial pure Al and to achieve maximum formability in the material. ISF experiments for producing an 80 mm diameter axisymmetric dome were carried out on 2 mm thickness commercially pure Al sheets for different tool speeds and feed rates in a CNC milling machine with a 10 mm hemispherical forming tool. The obtained parts were analyzed for springback, amount of thinning and maximum forming depth. The results showed that when the tool speed was increased by keeping the feed rate constant, the forming depth and thinning were also increased. On contrary, when the feed rate was increased by keeping the tool speed constant, the forming depth and thinning were decreased. Springback was found to be higher when the feed rate was increased rather than the tool speed was increased.

Student Difficulties in Analyzing Thin-Film Interference

NASA Astrophysics Data System (ADS)

Newburgh, Ronald; Goodale, Douglass

2009-04-01

A question we posed in a recent final examination has uncovered a fundamental difficulty for students in understanding destructive interference. The problem stated that glass of index n3 was coated with a thin film of a substance with index n2. The question then asked the student to calculate (a) the minimum coating thickness for maximum transmission into the glass and (b) the minimum thickness for minimum transmission into the glass, in both cases for a given wavelength. Questions from students during and after the examination showed that many had a problem in relating the interference to the transmission. We finally concluded that the source of confusion lay with an almost universally used figure in teaching interference in thin films, as well as the omission of the role of the electric field in reflection.

Study on Thermochromic VO2 Films Grown on ZnO-Coated Glass Substrates for “Smart Windows”

NASA Astrophysics Data System (ADS)

Kato, Kazuhiro; Song, Pung Keun; Odaka, Hidehumi; Shigesato, Yuzo

2003-10-01

Vanadium dioxide (VO2) is one of the most attractive thermochromic materials, which show large changes in optical and electrical properties at the transition temperature (Tt) close to the atmospheric temperature (approximately 340 K). We already reported for VO2 deposition by rf magnetron sputtering using V2O3 or V2O5 targets that VO2 films thicker than 400 nm showed high thermochromic performance, whereas the VO2 films thinner than 200 nm did not show such performance because of their poor crystallinity and off-stoichiometry. In this study, very thin thermochromic VO2 films with thicknesses of about 50 nm were successfully deposited using highly < 001>-preferred oriented ZnO polycrystalline films as a buffer layer between the VO2 film and glass substrate (VO2/ZnO/glass) because of the heteroepitaxial growth of VO2 polycrystalline films. W-doped VO2 films were also deposited on the ZnO-coated glass substrates (ZnO/glass) by cosputtering. It was confirmed that W doping for thin VO2 films deposited on the ZnO/glass can decrease Tt systematically. Such very thin VO2 films should have high potential for application in “smart windows”.

Studies of drag on the nanocomposite superhydrophobic surfaces

NASA Astrophysics Data System (ADS)

Brassard, Jean-Denis; Sarkar, D. K.; Perron, Jean

2015-01-01

The nanocomposite thin films of stearic acid (SA)-functionalized ZnO nanoparticles incorporated in epoxy polymer matrix have been achieved. The X-ray diffraction (XRD) studies show the formation of zinc stearate on ZnO nanoparticles as the confirmation of SA-functionalization of ZnO nanoparticles in the thin films. Morphological analyses reveal the presence of micro-holes with the presence of irregular nanoparticles. The measured root mean square (rms) roughness of the thin film is found to be 12 ± 1 μm with the adhesion of 5B on both glass and aluminum substrates. The wetting property shows that the surface of the film is superhydrophobic with the contact angle of water of 156 ± 4° having contact angle hysteresis (CAH) of 4 ± 2°. The average terminal velocity in the water of the as-received glass spheres and superhydrophobic spheres were found to be 0.66 ± 0.01 m/s and 0.72 ± 0.01 m/s respectively. Consequently, the calculated average coefficients of the surface drag of the as-received glass sphere and superhydrophobic glass sphere were 2.30 ± 0.01 and 1.93 ± 0.03, respectively. Hence, the drag reduction on the surface of superhydrophobic glass sphere is found to be approximately 16% lower than as-received glass sphere.

Multiferroic YCrO3 thin films grown on glass substrate: Resistive switching characteristics

NASA Astrophysics Data System (ADS)

Seo, Jeongdae; Ahn, Yoonho; Son, Jong Yeog

2016-01-01

Polycrystalline YCrO3 thin films were deposited on (111) Pt/Ta/glass substrates by pulsed laser deposition. The YCrO3 thin films exhibited good ferroelectric properties with remnant polarization of about 5 µC/cm2. Large leakage current was observed by I- V curve and ferroelectric hysteresis loop. The YCrO3 resistive random access memory (RRAM) capacitor showed unipolar switching behaviors with SET and RESET voltages higher than those of general NiO RRAM capacitors. [Figure not available: see fulltext.

Status of CdS/CdTe solar cell research at NREL

NASA Astrophysics Data System (ADS)

Ramanathan, K.; Dhere, R. G.; Coutts, T. J.; Chu, T.; Chu, S.

1992-12-01

We report on the deposition of thin cadmium sulfide (CdS) layers from aqueous solutions and their optical properties. CdS layers have been deposited on soda lime glass, tin oxide coated glass and copper indium diselenide (CuInSe2) thin films. A systematic increase in the absorption is found to occur with increasing concentration of the buffer salt used in the bath. CdS/CdTe thin film solar cells have been fabricated by close spaced sublimation of CdTe, yielding 11.3% devices.

Bismaleimide resins for flame resistant honeycomb sandwich panels

NASA Technical Reports Server (NTRS)

Stenzenberger, H. D.

1978-01-01

Bismaleimide resins are prime candidates for nonflammable aircraft interior panels. Three resin types with different structures and processing characteristics were formulated. Resin M 751 was used to fabricate 100 kg of glass fabric prepregs which were used for the preparation of face sheets for honeycomb sandwich panels. Prepreg characteristics and curing cycles for laminate fabrication are provided. In order to advance beyond the current solvent resin technology for fibre and fabric impregnation, a hot melt solvent-less resin system was prepared and characterized. Preliminary tests were performed to develop a wet bonding process for the fabrication of advanced sandwich honeycomb panels by use of polybismaleimide glass fabric face sheets and polybismaleimide Nomex honeycomb core. B-stage material was used for both the core and the face sheet, providing flatwise tensile properties equivalent to those obtained by the state-of-the-art 3-step process which includes an epoxy adhesive resin.

Noncontact Microembossing Technology for Fabricating Thermoplastic Optical Polymer Microlens Array Sheets

PubMed Central

Chang, Xuefeng; Ge, Xiaohong; Li, Hui

2014-01-01

Thermoplastic optical polymers have replaced traditional optical glass for many applications, due to their superior optical performance, mechanical characteristics, low cost, and efficient production process. This paper investigates noncontact microembossing technology used for producing microlens arrays made out of PMMA (polymethyl methacrylate), PS (polyStyrene), and PC (polycarbonate) from a quartz mold, with microhole arrays. An array of planoconvex microlenses are formed because of surface tension caused by applying pressure to the edge of a hole at a certain glass transition temperature. We studied the principle of noncontact microembossing techniques using finite element analysis, in addition to the thermal and mechanical properties of the three polymers. Then, the independently developed hot-embossing equipment was used to fabricate microlens arrays on PMMA, PS, and PC sheets. This is a promising technique for fabricating diverse thermoplastic optical polymer microlens array sheets, with a simple technological process and low production costs. PMID:25162063

Residual stress measurement in silicon sheet by shadow moire interferometry

NASA Technical Reports Server (NTRS)

Kwon, Y.; Danyluk, S.; Bucciarelli, L.; Kalejs, J. P.

1987-01-01

A shadow moire interferometry technique has been developed to measure residual strain in thin silicon sheet. The curvature of a segment of sheet undergoing four-point bending is analyzed to include the applied bending moments, the in-plane residual stresses, and the 'end effect' of the sheet since it is of finite length. The technique is applied to obtain residual stress distributions for silicon sheet grown by the edge-defined film-fed growth technique.

Experimental investigation and modeling of a direct-coupled PV/T air collector

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shahsavar, A.; Ameri, M.; Energy and Environmental Engineering Research Center, Shahid Bahonar University, Kerman

2010-11-15

Photovoltaic/thermal (PV/T) systems refer to the integration of photovoltaic and solar thermal technologies into one single system, in that both useful heat energy and electricity are produced. The impetus of this paper is to model a direct-coupled PV/T air collector which is designed, built, and tested at a geographic location of Kerman, Iran. In this system, a thin aluminum sheet suspended at the middle of air channel is used to increase the heat exchange surface and consequently improve heat extraction from PV panels. This PV/T system is tested in natural convection and forced convection (with two, four and eight fansmore » operating) and its unsteady results are presented in with and without glass cover cases. A theoretical model is developed and validated against experimental data, where good agreement between the measured values and those calculated by the simulation model were achieved. Comparisons are made between electrical performance of the different modes of operation, and it is concluded that there is an optimum number of fans for achieving maximum electrical efficiency. Also, results show that setting glass cover on photovoltaic panels leads to an increase in thermal efficiency and decrease in electrical efficiency of the system. (author)« less

Testing Mylar Multi-Gap Resistive Plate Chambers

NASA Astrophysics Data System (ADS)

Towell, Cecily; EIC PID Consortium Collaboration

2016-09-01

Quantum Chromodynamics (QCD) is the fundamental theory that successfully explains strong force interactions. To continue the effective study of QCD in nuclear structure, plans are being made to construct an Electron Ion Collider (EIC). Part of the preparation for the EIC includes continued detector development to push beyond their current capabilities. This includes Time of Flight (TOF) detectors, which are used for particle identification. Multi-Gap Resistive Plate Chambers (mRPCs) are a type of TOF detector that typically use glass to make small gas gaps within the detector to produce fast signals when a high energy particle goes through the detector. These extremely thin gaps of 0.2mm are key in achieving the excellent timing resolution capability of these detectors. A new mRPC design is being tested with the goal of reaching a timing resolution of 10ps. This design uses sheets of mylar in place of the glass so that the width of the dividers is smaller, thus vastly increasing the number of gas gaps. Multiple versions of this mylar mRPC have been made and tested. The methods for producing these mRPCs and their performance will be discussed. This research was supported by US DOE MENP Grant DE-FG02-03ER41243.

Investigation into the Fiber Orientation Effect on the Formability of GLARE Materials in the Stamp Forming Process

NASA Astrophysics Data System (ADS)

Liu, Shichen; Lang, Lihui; Sherkatghanad, Ehsan; Wang, Yao; Xu, Wencai

2018-04-01

Glass-reinforced aluminum laminate (GLARE) is a new class of fiber metal laminates (FMLs) which has the advantages such as high tensile strength, outstanding fatigue, impact resistance, and excellent corrosion properties. GLARE has been extensively applied in advanced aerospace and automobile industries. However, the deformation behavior of the glass fiber during forming must be studied to the benefits of the good-quality part we form. In this research, we focus on the effect of fiber layer orientation on the GLARE laminate formability in stamp forming process. Experimental and numerical analysis of stamping a hemisphere part in different fiber orientation is investigated. The results indicate that unidirectional and multi-directional fiber in the middle layer make a significant effect on the thinning and also surface forming quality of the three layer sheet. Furthermore, the stress-strain distribution of the aluminum alloy and the unique anisotropic property of the fiber layer exhibit that fiber layer orientation can also affect the forming depths as well as the fracture modes of the laminate. According to the obtained results, it is revealed that multi-directional fiber layers are a good alternative compared to the unidirectional fibers especially when a better formability is the purpose.

Method for optical and mechanically coupling optical fibers

DOEpatents

Toeppen, J.S.

1996-10-01

A method and apparatus are disclosed for splicing optical fibers. A fluorescing solder glass frit having a melting point lower than the melting point of first and second optical fibers is prepared. The solder glass frit is then attached to the end of the first optical fiber and/or the end of the second optical fiber. The ends of the optical fibers are aligned and placed in close proximity to each other. The solder glass frit is then heated to a temperature which is lower than the melting temperature of the first and second optical fibers, but which is high enough to melt the solder glass frit. A force is applied to the first and second optical fibers pushing the ends of the fibers towards each other. As the solder glass flit becomes molten, the layer of molten solder glass is compressed into a thin layer between the first and second optical fibers. The thin compressed layer of molten solder glass is allowed to cool such that the first and second optical fibers are bonded to each other by the hardened layer of solder glass. 6 figs.

Method for optical and mechanically coupling optical fibers

DOEpatents

Toeppen, John S.

1996-01-01

A method and apparatus for splicing optical fibers. A fluorescing solder glass frit having a melting point lower than the melting point of first and second optical fibers is prepared. The solder glass frit is then attached to the end of the first optical fiber and/or the end of the second optical fiber. The ends of the optical fibers are aligned and placed in close proximity to each other. The solder glass frit is then heated to a temperature which is lower than the melting temperature of the first and second optical fibers, but which is high enough to melt the solder glass frit. A force is applied to the first and second optical fibers pushing the ends of the fibers towards each other. As the solder glass flit becomes molten, the layer of molten solder glass is compressed into a thin layer between the first and second optical fibers. The thin compressed layer of molten solder glass is allowed to cool such that the first and second optical fibers are bonded to each other by the hardened layer of solder glass.

High Strength Glass Second Source Qualification to Composite Armor Specification MIL-L-46197(MR)

DTIC Science & Technology

1992-04-01

L-46197 (MR). The Owens Corning Fiberglass (OCF) S-2 glass woven roving product has set the standard for this application to structural armor. The...HIARTMAN. 1). R. liallistc Penetration of S 2 Glass L~aminates S-2 Glass I-iber Technical Paper. Owens Corning Fiberglass. I I 1ASKLI.. W E. Spall...Materials Marketing. Owens Corning F’iberglass- Toledo. O1l, 416𔄃 SR and RI1 Gla" Chemical Composition. Vetrotex Data Sheet. IM11 04-02-2 6

Observations on the relationship of structure to the mechanical properties of thin TD-NiCr sheet

NASA Technical Reports Server (NTRS)

Whittenberger, J. D.

1976-01-01

A study of the relationship between structure and mechanical properties of thin TD-NiCr sheet indicated that the elevated temperature tensile, stress-rupture, and creep strength properties are dependent on grain aspect ratio and sheet thickness. In general, the strength properties increase with increasing grain aspect ratio and sheet thickness. Tensile testing revealed an absence of ductility at elevated temperatures (not less than 1144 K). Significant creep damage as determined by subsequent tensile testing at room temperature occurs after very small amounts (less than 0.1%) of prior creep deformation over the temperature range 1144-1477 K. A threshold stress for creep appears to exist. Creep exposure below the threshold stress at T not less than 1366 K results in almost full retention of room temperature tensile properties.

Sheet-scanned dual-axis confocal microscopy using Richardson-Lucy deconvolution.

PubMed

Wang, D; Meza, D; Wang, Y; Gao, L; Liu, J T C

2014-09-15

We have previously developed a line-scanned dual-axis confocal (LS-DAC) microscope with subcellular resolution suitable for high-frame-rate diagnostic imaging at shallow depths. Due to the loss of confocality along one dimension, the contrast (signal-to-background ratio) of a LS-DAC microscope is deteriorated compared to a point-scanned DAC microscope. However, by using a sCMOS camera for detection, a short oblique light-sheet is imaged at each scanned position. Therefore, by scanning the light sheet in only one dimension, a thin 3D volume is imaged. Both sequential two-dimensional deconvolution and three-dimensional deconvolution are performed on the thin image volume to improve the resolution and contrast of one en face confocal image section at the center of the volume, a technique we call sheet-scanned dual-axis confocal (SS-DAC) microscopy.

Micrometer-thickness liquid sheet jets flowing in vacuum

NASA Astrophysics Data System (ADS)

Galinis, Gediminas; Strucka, Jergus; Barnard, Jonathan C. T.; Braun, Avi; Smith, Roland A.; Marangos, Jon P.

2017-08-01

Thin liquid sheet jet flows in vacuum provide a new platform for performing experiments in the liquid phase, for example X-ray spectroscopy. Micrometer thickness, high stability, and optical flatness are the key characteristics required for successful exploitation of these targets. A novel strategy for generating sheet jets in vacuum is presented in this article. Precision nozzles were designed and fabricated using high resolution (0.2 μm) 2-photon 3D printing and generated 1.49 ± 0.04 μm thickness, stable, and <λ /20-flat jets in isopropanol under normal atmosphere and under vacuum at 5 × 10-1 mbar. The thin sheet technology also holds great promise for advancing the fields of high harmonic generation in liquids, laser acceleration of ions as well as other fields requiring precision and high repetition rate targets.

Novel strip-cast Mg/Al clad sheets with excellent tensile and interfacial bonding properties

PubMed Central

Kim, Jung-Su; Lee, Dong Ho; Jung, Seung-Pill; Lee, Kwang Seok; Kim, Ki Jong; Kim, Hyoung Seop; Lee, Byeong-Joo; Chang, Young Won; Yuh, Junhan; Lee, Sunghak

2016-01-01

In order to broaden industrial applications of Mg alloys, as lightest-weight metal alloys in practical uses, many efforts have been dedicated to manufacture various clad sheets which can complement inherent shortcomings of Mg alloys. Here, we present a new fabrication method of Mg/Al clad sheets by bonding thin Al alloy sheet on to Mg alloy melt during strip casting. In the as-strip-cast Mg/Al clad sheet, homogeneously distributed equi-axed dendrites existed in the Mg alloy side, and two types of thin reaction layers, i.e., γ (Mg17Al12) and β (Mg2Al3) phases, were formed along the Mg/Al interface. After post-treatments (homogenization, warm rolling, and annealing), the interfacial layers were deformed in a sawtooth shape by forming deformation bands in the Mg alloy and interfacial layers, which favorably led to dramatic improvement in tensile and interfacial bonding properties. This work presents new applications to multi-functional lightweight alloy sheets requiring excellent formability, surface quality, and corrosion resistance as well as tensile and interfacial bonding properties. PMID:27245687

Extreme energetic particle decreases near geostationary orbit - A manifestation of current diversion within the inner plasma sheet

NASA Technical Reports Server (NTRS)

Baker, D. N.; Mcpherron, R. L.

1990-01-01

A qualitative model of magnetic field reconfiguration as might result from neutral line formation in the central plasma sheet late in a substorm growth phase is considered. It is suggested that magnetic reconnection probably begins before the substorm expansion phase and that cross-tail current is enhanced across the plasma sheet both earthward and tailward of a limited region near the neutral line. Such an enhanced cross-tail current earthward of the original X line region may contribute to thinning the plasma sheet substantially, and this would in turn affect the drift currents in that location, thus enhancing the current even closer toward the earth. In this way a redistribution and progressive diversion of normal cross-tail current throughout much of the inner portion of the plasma sheet could occur. The resulting intensified current, localized at the inner edge of the plasma sheet, would lead to a very thin plasma confinement region. This would explain the very taillike field and extreme particle dropouts often seen late in substorm growth phases.

Novel strip-cast Mg/Al clad sheets with excellent tensile and interfacial bonding properties.

PubMed

Kim, Jung-Su; Lee, Dong Ho; Jung, Seung-Pill; Lee, Kwang Seok; Kim, Ki Jong; Kim, Hyoung Seop; Lee, Byeong-Joo; Chang, Young Won; Yuh, Junhan; Lee, Sunghak

2016-06-01

In order to broaden industrial applications of Mg alloys, as lightest-weight metal alloys in practical uses, many efforts have been dedicated to manufacture various clad sheets which can complement inherent shortcomings of Mg alloys. Here, we present a new fabrication method of Mg/Al clad sheets by bonding thin Al alloy sheet on to Mg alloy melt during strip casting. In the as-strip-cast Mg/Al clad sheet, homogeneously distributed equi-axed dendrites existed in the Mg alloy side, and two types of thin reaction layers, i.e., γ (Mg17Al12) and β (Mg2Al3) phases, were formed along the Mg/Al interface. After post-treatments (homogenization, warm rolling, and annealing), the interfacial layers were deformed in a sawtooth shape by forming deformation bands in the Mg alloy and interfacial layers, which favorably led to dramatic improvement in tensile and interfacial bonding properties. This work presents new applications to multi-functional lightweight alloy sheets requiring excellent formability, surface quality, and corrosion resistance as well as tensile and interfacial bonding properties.

E12 sheet plastination: Techniques and applications.

PubMed

Ottone, Nicolas Ernesto; Baptista, Carlos A C; Latorre, Rafael; Bianchi, Homero Felipe; Del Sol, Mariano; Fuentes, Ramon

2017-10-30

Plastination is an anatomical technique that consists of replacing the liquids and fat of specimens by reactive polymers through forced impregnation in a vacuum. These are then polymerized to achieve the final result. E12 sheet plastination involves epoxy resin impregnation of thin (2-4 mm) and ultra-thin (<2 mm) tissue sheets, producing dry, transparent, odorless, non-toxic and long-lasting sheets. E12 sheet plastination techniques were reviewed using MEDLINE, EMBASE and SciELO databases, and manual searches. After searching, 616 records were found using the online and manual searches (MEDLINE, n: 207; EMBASE, n: 346; SciELO, n: 44; Manual search: 23). Finally, 96 records were included in this review (after duplicates and articles unrelated to the subject were excluded). The aim of this work was to review the E12 sheet plastination technique, searching for articles concerning views of it, identifying the different variants implemented by researchers since its creation by Gunther von Hagens, and to identify its applications from teaching and research in anatomy to morphological sciences. Clin. Anat., 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Li-ion transport in all-solid-state lithium batteries with LiCoO 2 using NASICON-type glass ceramic electrolytes

NASA Astrophysics Data System (ADS)

Xie, J.; Imanishi, N.; Zhang, T.; Hirano, A.; Takeda, Y.; Yamamoto, O.

LiCoO 2 thin films were deposited on the NASICON-type glass ceramics, Li 1+ x+ yAl xTi 2- xSi yP 3- yO 12, by radio frequency (RF) magnetron sputtering and were annealed at different temperatures. The as-deposited and the annealed LiCoO 2 thin films were characterized by X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscopy (SEM). It was found that the films exhibited a (1 0 4) preferred orientation after annealing and Co 3O 4 was observed by annealing over 500 °C due to the reaction between the LiCoO 2 and the glass ceramics. The effect of annealing temperature on the interfacial resistance of glass ceramics/LiCoO 2 and Li-ion transport in the bulk LiCoO 2 thin film was investigated by galvanostatic cycling, cyclic voltammetry (CV), potentiostatic intermittent titration technique (PITT) and electrochemical impedance spectroscopy (EIS) with the Li/PEO/glass ceramics/LiCoO 2 cell. The cell performance was limited by the Li-ion diffusion resistance in Ohara/LiCoO 2 interface as well as in bulk LiCoO 2.

Enhancement of conduction noise absorption by hybrid absorbers composed of indium-tin-oxide thin film and magnetic composite sheet on a microstrip line

NASA Astrophysics Data System (ADS)

Kim, Sun-Hong; Kim, Sung-Soo

2014-05-01

In order to develop wide-band noise absorbers with a focused design for low frequency performance, this study investigates hybrid absorbers that are composed of conductive indium-tin-oxide (ITO) thin film and magnetic composite sheets. The ITO films prepared via reactive sputtering exhibit a typical value of electrical resistivity of ≃10-4 Ω m. Rubber composites with flaky Fe-Si-Al particles are used as the magnetic sheet with a high permeability and high permittivity. For the ITO film with a low surface resistance and covered by the magnetic sheet, approximately 90% power absorption can be obtained at 1 GHz, which is significantly higher than that of the original magnetic sheet or ITO film. The high power absorption of the hybrid absorber is attributed to the enhanced ohmic loss of the ITO film through increased electric field strength bounded by the upper magnetic composite sheet. However, for the reverse layering sequence of the ITO film, the electric field experienced by ITO film is very weak due to the electromagnetic shielding by the under layer of magnetic sheet, which does not result in enhanced power absorption.

Freestanding two-dimensional Ni(OH)2 thin sheets assembled by 3D nanoflake array as basic building units for supercapacitor electrode materials.

PubMed

Song, Dianmei; Zhu, Jikui; Xuan, Liying; Zhao, Chenglan; Xie, Li; Chen, Lingyun

2018-01-01

Freestanding two dimensional (2D) porous nanostructures have great potential in electrical energy storage. In the present work, we reported the first synthesis of two-dimensional (2D) β-Ni(OH) 2 thin sheets (CQU-Chen-Ni-O-H-1) assembled by 3D nanoflake array as basic building units under acid condition by direct hydrothermal decomposition of the mixed solution of nickel nitrate (Ni(NO 3 ) 2 ) and acetic acid (CH 3 COOH, AA). The unique 3D nanoflake array assembled mesoporous 2D structures endow the thin sheets with a high specific capacitance of 1.78Fcm -2 (1747.5Fg -1 ) at the current density of 1.02mAcm -2 and good rate capability of 67.4% retain from 1.02 to 10.2mAcm -2 . The corresponding assembled asymmetric supercapacitor (ASC) achieves (CQU-Chen-Ni-O-H-1//active carbon (AC)) a high voltage of 1.8V and an energy density of 23.45Whkg -1 with a maximum power density of 9kWkg -1 , as well as cycability with 93.6% capacitance retention after 10,000 cycles. These results show the mesoporous thin sheets have great potential for SCs and other energy storage devices. Copyright © 2017 Elsevier Inc. All rights reserved.

Determining Beta Sheet Crystallinity in Fibrous Proteins by Thermal Analysis and Infrared Spectroscopy

NASA Astrophysics Data System (ADS)

Hu, Xiao; Kaplan, David; Cebe, Peggy

2007-03-01

We report a study of self-assembled beta pleated sheets in Bombyx mori silk fibroin films using thermal analysis and infrared spectroscopy. Crystallization of beta pleated sheets was effected either by heating the films above the glass transition temperature (Tg) and holding isothermally, or by exposure to methanol. The fractions of secondary structural components including random coils, alpha helices, beta pleated sheets, turns, and side chains, were evaluated using Fourier self-deconvolution (FSD) of the infrared absorbance spectra. As crystalline beta sheets form, the heat capacity increment from the TMDSC trace at Tg is systematically decreased and is linearly well correlated with beta sheet content determined from FSD. This analysis of beta sheet content can serve as an alternative to X-ray methods and may have wide applicability to other crystalline beta sheet forming proteins.

Sputter deposition of PZT piezoelectric films on thin glass substrates for adjustable x-ray optics.

PubMed

Wilke, Rudeger H T; Johnson-Wilke, Raegan L; Cotroneo, Vincenzo; Davis, William N; Reid, Paul B; Schwartz, Daniel A; Trolier-McKinstry, Susan

2013-05-10

Piezoelectric PbZr(0.52)Ti(0.48)O(3) (PZT) thin films deposited on thin glass substrates have been proposed for adjustable optics in future x-ray telescopes. The light weight of these x-ray optics enables large collecting areas, while the capability to correct mirror figure errors with the PZT thin film will allow much higher imaging resolution than possible with conventional lightweight optics. However, the low strain temperature and flexible nature of the thin glass complicate the use of chemical-solution deposition due to warping of the substrate at typical crystallization temperatures for the PZT. RF magnetron sputtering enabled preparation of PZT films with thicknesses up to 3 μm on Schott D263 glass substrates with much less deformation. X-ray diffraction analysis indicated that the films crystallized with the perovskite phase and showed no indication of secondary phases. Films with 1 cm(2) electrodes exhibited relative permittivity values near 1100 and loss tangents below 0.05. In addition, the remanent polarization was 26 μC/cm(2) with coercive fields of 33 kV/cm. The transverse piezoelectric coefficient was as high as -6.1±0.6 C/m(2). To assess influence functions for the x-ray optics application, the piezoelectrically induced deflection of individual cells was measured and compared with finite-element-analysis calculations. The good agreement between the results suggests that actuation of PZT thin films can control mirror figure errors to a precision of about 5 nm, allowing sub-arcsecond imaging.

Development of a highly transparent superamphiphobic plastic sheet by nanoparticle and chemical coating.

PubMed

Wong, Ten It; Wang, Hao; Wang, Fuke; Sin, Sau Leng; Quan, Cheng Gen; Wang, Shi Jie; Zhou, Xiaodong

2016-04-01

A highly transparent superamphiphobic plastic sheet was developed. The plastic sheet polymethyl methacrylate (PMMA) was spin-coated on a glass substrate. Synthesized silica nanoparticles were sprayed on PMMA, followed by fluorosilane drop-coating. The results of contact angle measurements show that the developed PMMA sheet has superamphiphobic properties with high advancing contact angles for water (154°), toluene (139°), and silicone oil (132.9°). The amphiphobicity of the plastic sheet can be tuned by the surface coverage of the silica nanoparticles distributed on the PMMA surface. The surface coverage of the nanoparticles on our PMMA sheet is about 20%, and it agrees with our contact angle calculations for the sheet with and without nanoparticles. Copyright © 2016 Elsevier Inc. All rights reserved.

Highly Conductive Flexible Multi-Walled Carbon Nanotube Sheet Films for Transparent Touch Screen

NASA Astrophysics Data System (ADS)

Jung, Daewoong; Lee, Kyung Hwan; Kim, Donghyun; Burk, Dorothea; Overzet, Lawrence J.; Lee, Gil Sik

2013-03-01

Highly conductive and transparent thin films were prepared using highly purified multi-walled carbon nanotube (MWCNT) sheets. The electrical properties of the MWCNT sheet were remarkably improved by an acid treatment, resulting in densely packed MWCNTs. The morphology of the sheets reveals that continuous electrical pathways were formed by the acid treatment, greatly improving the sheet resistance all the while maintaining an excellent optical transmittance. These results encourage the use of these MWCNT sheets with low sheet resistance (450 Ω/sq) and high optical transmittance (90%) as a potential candidate for flexible display applications.

Communication: Non-Newtonian rheology of inorganic glass-forming liquids: Universal patterns and outstanding questions

NASA Astrophysics Data System (ADS)

Zhu, W.; Aitken, B. G.; Sen, S.

2017-02-01

All families of inorganic glass-forming liquids display non-Newtonian rheological behavior in the form of shear thinning at high shear rates. Experimental evidence is presented to demonstrate the existence of remarkable universality in this behavior, irrespective of chemical composition, structure, topology, and viscosity. However, contrary to intuition, in all cases the characteristic shear rates that mark the onset of shear thinning in these liquids are orders of magnitude slower than the global shear relaxation rates. Attempt is made to reconcile such differences within the framework of the cooperative structural relaxation model of glass-forming liquids.

Self-similarity and scaling transitions during rupture of thin free films of Newtonian fluids

NASA Astrophysics Data System (ADS)

Thete, Sumeet Suresh; Anthony, Christopher; Doshi, Pankaj; Harris, Michael T.; Basaran, Osman A.

2016-09-01

Rupture of thin liquid films is crucial in many industrial applications and nature such as foam stability in oil-gas separation units, coating flows, polymer processing, and tear films in the eye. In some of these situations, a liquid film may have two free surfaces (referred to here as a free film or a sheet) as opposed to a film deposited on a solid substrate that has one free surface. The rupture of such a free film or a sheet of a Newtonian fluid is analyzed under the competing influences of inertia, viscous stress, van der Waals pressure, and capillary pressure by solving a system of spatially one-dimensional evolution equations for film thickness and lateral velocity. The dynamics close to the space-time singularity where the film ruptures is asymptotically self-similar and, therefore, the problem is also analyzed by reducing the transient partial differential evolution equations to a corresponding set of ordinary differential equations in similarity space. For sheets with negligible inertia, it is shown that the dominant balance of forces involves solely viscous and van der Waals forces, with capillary force remaining negligible throughout the thinning process in a viscous regime. On the other hand, for a sheet of an inviscid fluid for which the effect of viscosity is negligible, it is shown that the dominant balance of forces is between inertial, capillary, and van der Waals forces as the film evolves towards rupture in an inertial regime. Real fluids, however, have finite viscosity. Hence, for real fluids, it is further shown that the viscous and the inertial regimes are only transitory and can only describe the initial thinning dynamics of highly viscous and slightly viscous sheets, respectively. Moreover, regardless of the fluid's viscosity, it is shown that for sheets that initially thin in either of these two regimes, their dynamics transition to a late stage or final inertial-viscous regime in which inertial, viscous, and van der Waals forces balance each other while capillary force remains negligible, in accordance with the results of Vaynblat, Lister, and Witelski.

Laser readable thermoluminescent radiation dosimeters and methods for producing thereof

DOEpatents

Braunlich, Peter F.; Tetzlaff, Wolfgang

1989-01-01

Thin layer thermoluminescent radiation dosimeters for use in laser readable dosimetry systems, and methods of fabricating such thin layer dosimeters. The thin layer thermoluminescent radiation dosimeters include a thin substrate made from glass or other inorganic materials capable of withstanding high temperatures and high heating rates. A thin layer of a thermoluminescent phoshphor material is heat bonded to the substrate using an inorganic binder such as glass. The dosimeters can be mounted in frames and cases for ease in handling. Methods of the invention include mixing a suitable phosphor composition and binder, both being in particulate or granular form. The mixture is then deposited onto a substrate such as by using mask printing techniques. The dosimeters are thereafter heated to fuse and bond the binder and phosphor to the substrate.

Understanding glass-forming ability through sluggish crystallization of atomically thin metallic glassy films

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, Y. T.; Cao, C. R.; Huang, K. Q.

2014-08-04

The glass-forming ability (GFA) of an alloy, closely related to its ability to resist crystallization, is a crucial issue in condensed matter physics. So far, the studies on GFA are mostly statistical and empirical guides. Benefiting from the ultrahigh thermal stability of ultrathin metallic glassy film and high resolution spherical aberration-corrected transmission electron microscope, the crystallization of atomically thin ZrCu and its microalloyed ZrCuAl glasses with markedly different GFA was investigated at the atomic scale. We find the Zr diffusivity estimated from the density of nuclei is dramatically decreased by adding of Al, which is the major reason for themore » much better GFA of the ZrCuAl metallic glass.« less

Triggering of explosive reconnection in a thick current sheet via current sheet compression: Less current sheet thinning, more temperature anisotropy

NASA Astrophysics Data System (ADS)

Shimizu, K.; Shinohara, I.; Fujimoto, M.

2016-12-01

Two-dimensional kinetic simulations of compression of thick current sheets are performed to see how it can lead to triggering of explosive magnetic reconnection. The current sheet under study is simply in a Harris-like anti-paralell and symmetric geometry. A one-dimensional pre-study shows that the compression is more effective to make the plasma anisotropy than to thin the current sheet width. When the lobe magnetic field is amplified by a factor of 2, the plasma temperature anisotropy inside the current sheet reaches 2 but the current sheet thickness is reduced only by 1/sqrt(2). If a current sheet thickness needs to be comparable to the ion inertial scale for reconnection triggering take place, as is widely and frequently mentioned in the research community, the initial thickness cannot be more than a few ion scale for reconnection to set-in. On the other hand, the temperature anisotropy of 2 can be significant for the triggering problem. Two-dimensional simulations show explosive magnetic reconnection to take place even when the initial current sheet thickness more than an order of magnitude thicker than the ion scale, indicating the resilient triggering drive supplied by the temperature anisotropy. We also discuss how the reconnection triggering capability of the temperature anisotropy boosted tearing mode for thick current sheets compares with the instabilities in the plane orthogonal to the reconnecting field.

Magnetic Configurations of the Tilted Current Sheets and Dynamics of Their Flapping in Magnetotail

NASA Astrophysics Data System (ADS)

Shen, C.; Rong, Z. J.; Li, X.; Dunlop, M.; Liu, Z. X.; Malova, H. V.; Lucek, E.; Carr, C.

2009-04-01

Based on multiple spacecraft measurements, the geometrical structures of tilted current sheet and tail flapping waves have been analyzed and some features of the tilted current sheets have been made clear for the first time. The geometrical features of the tilted current sheet revealed in this investigation are as follows: (1) The magnetic field lines (MFLs) are generally plane curves and the osculating planes in which the MFLs lie are about vertical to the magnetic equatorial plane, while the tilted current sheet may lean severely to the dawn or dusk side. (2) The tilted current sheet may become very thin, its half thickness is generally much less than the minimum radius of the curvature of the MFLs. (3) In the neutral sheet, the field-aligned current density becomes very large and has a maximum value at the center of the current sheet. (4) In some cases, the current density is a bifurcated one, and the two humps of the current density often superpose two peaks in the gradient of magnetic strength, indicating that the magnetic gradient drift current is possibly responsible for the formation of the two humps of the current density in some tilted current sheets. Tilted current sheets often appear along with tail thick current sheet flapping waves. It is found that, in the tail flapping current sheets, the minimum curvature radius of the MFLs in the current sheet is rather large with values around 1RE, while the neutral sheet may be very thin, with its half thickness being several tenths ofRE. During the flapping waves, the current sheet is tilted substantially, and the maximum tilt angle is generally larger than 45

Extracellular matrix proteins as temporary coating for thin-film neural implants

NASA Astrophysics Data System (ADS)

Ceyssens, Frederik; Deprez, Marjolijn; Turner, Neill; Kil, Dries; van Kuyck, Kris; Welkenhuysen, Marleen; Nuttin, Bart; Badylak, Stephen; Puers, Robert

2017-02-01

Objective. This study investigates the suitability of a thin sheet of extracellular matrix (ECM) proteins as a resorbable coating for temporarily reinforcing fragile or ultra-low stiffness thin-film neural implants to be placed on the brain, i.e. microelectrocorticographic (µECOG) implants. Approach. Thin-film polyimide-based electrode arrays were fabricated using lithographic methods. ECM was harvested from porcine tissue by a decellularization method and coated around the arrays. Mechanical tests and an in vivo experiment on rats were conducted, followed by a histological tissue study combined with a statistical equivalence test (confidence interval approach, 0.05 significance level) to compare the test group with an uncoated control group. Main results. After 3 months, no significant damage was found based on GFAP and NeuN staining of the relevant brain areas. Significance. The study shows that ECM sheets are a suitable temporary coating for thin µECOG neural implants.

West Antarctic Ice Sheet retreat driven by Holocene warm water incursions

PubMed Central

Hillenbrand, Claus-Dieter; Smith, James A.; Hodell, David A.; Greaves, Mervyn; Poole, Christopher R.; Kender, Sev; Williams, Mark; Andersen, Thorbjørn Joest; Jernas, Patrycja E.; Klages, Johann P.; Roberts, Stephen J.; Gohl, Karsten; Larter, Robert D.; Kuhn, Gerhard

2017-01-01

Glaciological and oceanographic observations coupled with numerical models show that warm Circumpolar Deep Water (CDW) upwelling onto the West Antarctic continental shelf causes melting of the undersides of floating ice shelves. Because these ice shelves buttress glaciers feeding into them, their ocean-induced thinning is driving Antarctic ice-sheet loss today. Here we present the first multi-proxy data based reconstruction of variability in CDW inflow to the Amundsen Sea sector, the most vulnerable part of the West Antarctic Ice Sheet, during the last 11,000 years. The chemical composition of foraminifer shells and benthic foraminifer assemblages in marine sediments indicate that enhanced CDW upwelling, controlled by the latitudinal position of the Southern Hemisphere westerly winds, forced deglaciation of this sector both until 7,500 years ago, when an ice-shelf collapse may have caused rapid ice-sheet thinning further upstream, and since the 1940s. These results increase confidence in the predictive capability of current ice-sheet models. PMID:28682333

West Antarctic Ice Sheet retreat driven by Holocene warm water incursions.

PubMed

Hillenbrand, Claus-Dieter; Smith, James A; Hodell, David A; Greaves, Mervyn; Poole, Christopher R; Kender, Sev; Williams, Mark; Andersen, Thorbjørn Joest; Jernas, Patrycja E; Elderfield, Henry; Klages, Johann P; Roberts, Stephen J; Gohl, Karsten; Larter, Robert D; Kuhn, Gerhard

2017-07-05

Glaciological and oceanographic observations coupled with numerical models show that warm Circumpolar Deep Water (CDW) incursions onto the West Antarctic continental shelf cause melting of the undersides of floating ice shelves. Because these ice shelves buttress glaciers feeding into them, their ocean-induced thinning is driving Antarctic ice-sheet retreat today. Here we present a multi-proxy data based reconstruction of variability in CDW inflow to the Amundsen Sea sector, the most vulnerable part of the West Antarctic Ice Sheet, during the Holocene epoch (from 11.7 thousand years ago to the present). The chemical compositions of foraminifer shells and benthic foraminifer assemblages in marine sediments indicate that enhanced CDW upwelling, controlled by the latitudinal position of the Southern Hemisphere westerly winds, forced deglaciation of this sector from at least 10,400 years ago until 7,500 years ago-when an ice-shelf collapse may have caused rapid ice-sheet thinning further upstream-and since the 1940s. These results increase confidence in the predictive capability of current ice-sheet models.

Controlled bending and folding of a bilayer structure consisting of a thin stiff film and a heat shrinkable polymer sheet

NASA Astrophysics Data System (ADS)

Cui, Jianxun; Adams, John G. M.; Zhu, Yong

2018-05-01

Bending pre-designed flat sheets into three-dimensional (3D) structures is attracting much interest, as it provides a simple approach to make 3D devices. Here we report controlled bending and folding of a bilayer structure consisting of a heat shrinkable polymer sheet and a thin stiff film (not thermally responsive). Upon heating, the prestrained polymer sheet shrinks, leading to bending or folding of the bilayer. We studied the effect of relative dimensions of the two layers on the bending behavior and demonstrated the transition from longitudinal bending to transverse bending of the bilayer strip. Transverse bending was utilized to fold origami structures, including several flat letters, a crane, and a corrugated metal sheet via Miura-ori folding. We developed a method to further control the bending orientation based on bio-inspired anisotropic bending stiffness. By bending the metal foil in different orientations, several structures were obtained, including cylindrical surfaces and left-handed/right-handed helical structures.

Scaling results for the liquid sheet radiator

NASA Technical Reports Server (NTRS)

Chubb, Donald L.; Calfo, Frederick D.

1989-01-01

Surface tension forces at the edges of a thin liquid (approx 100 micrometers) sheet flow result in a triangularly shaped sheet. Such a geometry is ideal for an external flow radiator. The experimental investigation of such sheet flows was extended to large sheets (width = 23.5 cm, length = 3.5 m). Experimental L/W results are greater than the calculated results. However, more experimental results are necessary for a complete comparison. The calculated emissivity of a sheet of Dow-Corning 705 silicone oil, which is low temperature (300-400 K) candidate for a liquid sheet radiator (LSR), is greater than 0.8 for sheet thicknesses greater than 100 micrometers.

Perforating Thin Metal Sheets

NASA Technical Reports Server (NTRS)

Davidson, M. E.

1985-01-01

Sheets only few mils thick bonded together, punched, then debonded. Three-step process yields perforated sheets of metal. (1): Individual sheets bonded together to form laminate. (2): laminate perforated in desired geometric pattern. (3): After baking, laminate separates into individual sheets. Developed for fabricating conductive layer on blankets that collect and remove ions; however, perforated foils have other applications - as conductive surfaces on insulating materials; stiffeners and conductors in plastic laminates; reflectors in antenna dishes; supports for thermal blankets; lightweight grille cover materials; and material for mockup of components.

Electrochemical cell with high conductivity glass electrolyte

DOEpatents

Nelson, P.A.; Bloom, I.D.; Roche, M.F.

1986-04-17

A secondary electrochemical cell with sodium-sulfur or other molten reactants is provided with an ionically conductive glass electrolyte. The cell is contained within an electrically conductive housing with a first portion at negative potential and a second portion insulated therefrom at positive electrode potential. The glass electrolyte is formed into a plurality of elongated tubes and placed lengthwise within the housing. The positive electrode material, for instance sulfur, is sealed into the glass electrolyte tubes and is provided with an elongated axial current collector. The glass electrolyte tubes are protected by shield tubes or sheets that also define narrow annuli for wicking of the molten negative electrode material.

Electrochemical cell with high conductivity glass electrolyte

DOEpatents

Nelson, P.A.; Bloom, I.D.; Roche, M.F.

1987-04-21

A secondary electrochemical cell with sodium-sulfur or other molten reactants is provided with a ionically conductive glass electrolyte. The cell is contained within an electrically conductive housing with a first portion at negative potential and a second portion insulated therefrom at positive electrode potential. The glass electrolyte is formed into a plurality of elongated tubes and placed lengthwise within the housing. The positive electrode material, for instance sulfur, is sealed into the glass electrolyte tubes and is provided with an elongated axial current collector. The glass electrolyte tubes are protected by shield tubes or sheets that also define narrow annuli for wicking of the molten negative electrode material. 6 figs.

Electrochemical cell with high conductivity glass electrolyte

DOEpatents

Nelson, Paul A.; Bloom, Ira D.; Roche, Michael F.

1987-01-01

A secondary electrochemical cell with sodium-sulfur or other molten reactants is provided with a ionically conductive glass electrolyte. The cell is contained within an electrically conductive housing with a first portion at negative potential and a second portion insulated therefrom at positive electrode potential. The glass electrolyte is formed into a plurality of elongated tubes and placed lengthwise within the housing. The positive electrode material, for instance sulfur, is sealed into the glass electrolyte tubes and is provided with an elongated axial current collector. The glass electrolyte tubes are protected by shield tubes or sheets that also define narrow annuli for wicking of the molten negative electrode material.

Room-temperature growth of thin films of niobium on strontium titanate (0 0 1) single-crystal substrates for superconducting joints

NASA Astrophysics Data System (ADS)

Shimizu, Yuhei; Tonooka, Kazuhiko; Yoshida, Yoshiyuki; Furuse, Mitsuho; Takashima, Hiroshi

2018-06-01

With the eventual aim of forming joints between superconducting wires of YBa2Cu3O7-δ (YBCO), thin films of Nb were grown at room-temperature on SrTiO3 (STO) (0 0 1), a single-crystal substrate that shows good lattice matching with YBCO. The crystallinity, surface morphology, and superconducting properties of the Nb thin films were investigated and compared with those of similar films grown on a silica glass substrate. The Nb thin films grew with an (hh0) orientation on both substrates. The crystallinity of the Nb thin films on the STO substrate was higher than that on the silica glass substrate. X-ray diffraction measurements and observation of the surface morphology by atomic-force microscopy indicated that Nb grew in the plane along the [1 0 0] and [0 1 0] directions of the STO substrate. This growth mode relaxes strain between Nb and STO, and is believed to lead to the high crystallinity observed. As a result, the Nb thin films on the STO substrates showed lower electric resistivity and a higher superconducting transition temperature than did those on the silica glass substrates. The results of this study should be useful in relation to the production of superconducting joints.

Comparison of thin-film resistance heat-transfer gages with thin-skin transient calorimeter gages in conventional hypersonic wind tunnels

NASA Technical Reports Server (NTRS)

Miller, C. G., III

1981-01-01

Thin film gages deposited at the stagnation region of small (8.1-mm-diameter) hemispheres and gages mounted flush with the surface of a sharp-leading-edge flat plate were tested in the Langley continuous-flow hypersonic tunnel and in the Langley hypersonic CF4 tunnel. Two substrate materials were tested, quartz and a machinable glass-ceramic. Small hemispheres were also tested utilizing the thin-skin transient calorimeter technique usually employed in conventional tunnels. One transient calorimeter model was a thin shell of stainless steel, and the other was a thin-skin insert of stainless steel mounted into a hemisphere fabricated from a machinable-glass-ceramic. Measured heat-transfer rates from the various hemispheres were compared with one another and with predicted rates. The results demonstrate the feasibility and advantages of using-film resistance heat-transfer gages in conventional hypersonic wind tunnels over a wide range of conditions.

Growth and characterization of highly conducting Al-doped ZnO (AZO) thin films for optoelectronic applications

NASA Astrophysics Data System (ADS)

Sardana, Sanjay K.; Singh, Anil; Srivastava, Sanjay K.; Pandya, Dinesh K.

2018-05-01

A comparative study of undoped ZnO and Al-doped ZnO (AZO) thin films deposited on glass substrate by spray pyrolysis has been carried out at various aqueous molar concentration of zinc acetate. The thin films deposited on glass shows the wurtzite phase of ZnO, confirmed by X-ray diffraction. The optical study shows the high transmittance over 80% in the visible regime. The band gap of AZO thin films shows a blue shift as compared to undoped ZnO, which has been attributed to Burstein-Moss shift. Heat treatment of these samples in vacuum showed the improved conductivity in compared to as-deposited thin films. The electric study shows the minimum resistivity of 8 x 10-3 Ω-cm and carrier concentration of 6.5 × 1019 /cm3 correspond to AZO thin films.

Theoretical simulations of protective thin film Fabry-Pérot filters for integrated optical elements of diode pumped alkali lasers (DPAL)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Quarrie, L., E-mail: Lindsay.Quarrie@l-3com.com, E-mail: lindsay.o.quarrie@gmail.com; Air Force Research Laboratory, AFRL/RDLC Laser CoE, 3550 Aberdeen Avenue SE, Kirtland AFB, NM 87117-5776

The lifetime of Diode-Pumped Alkali Lasers (DPALs) is limited by damage initiated by reaction of the glass envelope of its gain medium with rubidium vapor. Rubidium is absorbed into the glass and the rubidium cations diffuse through the glass structure, breaking bridging Si-O bonds. A damage-resistant thin film was developed enhancing high-optical transmission at natural rubidium resonance input and output laser beam wavelengths of 780 nm and 795 nm, while protecting the optical windows of the gain cell in a DPAL. The methodology developed here can be readily modified for simulation of expected transmission performance at input pump and outputmore » laser wavelengths using different combination of thin film materials in a DPAL. High coupling efficiency of the light through the gas cell was accomplished by matching the air-glass and glass-gas interfaces at the appropriate wavelengths using a dielectric stack of high and low index of refraction materials selected to work at the laser energies and protected from the alkali metal vapor in the gain cell. Thin films as oxides of aluminum, zirconium, tantalum, and silicon were selected allowing the creation of Fabry-Perot optical filters on the optical windows achieving close to 100% laser transmission in a solid optic combination of window and highly reflective mirror. This approach allows for the development of a new whole solid optic laser.« less

Effect of Se addition on optical and electrical properties of chalcogenide CdSSe thin films

NASA Astrophysics Data System (ADS)

Hassanien, A. S.; Akl, Alaa A.

2016-01-01

Compositional dependence of optical and electrical properties of chalcogenide CdSxSe1-x (0.4 ≥ x ≥ 0.0 at. %) thin films was studied. Cadmium sulphoselenide films were deposited by thermal evaporation technique at vacuum (8.2 × 10-4 Pa) onto preheated glass substrates (523 K). The evaporation rate and film thickness were kept constant at 2.50 nm/s and 375 ± 5 nm, respectively. X-ray diffractograms showed that, the deposited films have the low crystalline nature. Energy dispersive analysis by X-ray (EDAX) was used to check the compositional elements of deposited films. The absorption coefficient was determined from transmission and reflection measurements at room temperature in the wavelength range 300-2500 nm. Optical density, skin depth, optical energy gap and Urbach's parameters of CdSSe thin films have also been estimated. The direct optical energy gap decreased from 2.248 eV to 1.749 eV when the ratio of Se-content was increased from 0.60 to 1.00 . Conduction band and valance band positions were evaluated. The temperature dependence of dc-electrical resistivity in the temperature range (293-450 K) has been reported. Three conduction regions due to different conduction mechanisms were detected. Electrical sheet resistance, activation energy and pre-exponential parameters were discussed. The estimated values of optical and electrical parameters were strongly dependent upon the Se-content in CdSSe matrix.

International Conference on Optical Computing Held in Edinburgh, Scotland on August 22-25, 1994. Technical Digest

DTIC Science & Technology

1994-08-24

Kusuda, T. Kishimoto and Y. Mitsuhashi, Nippon Sheet Glass Co. Ltd., lbaraki, Japan. A vertical and horizontal integration technique of free-space...transparent electrode on a piece of cover glass drives the liquid crystal into the desired state. Data are transferred to the SLM over 32 parallel...shows that the shift registers and clock generation circuits function as designed. A cover- glass was fixed over the pixel array, spaced with polyimide

Maxwell's theory of eddy currents in thin conducting sheets, and applications to electromagnetic shielding and MAGLEV

NASA Astrophysics Data System (ADS)

Saslow, W. M.

1992-08-01

Using the example of a monopole that is spontaneously generated above a thin conducting sheet, the simplicity and power of Maxwell's 1872 theory of eddy currents in thin conducting sheets is illustrated. This theory employs a receding image construction, with a characteristic recession velocity v0=2/(μ0σd), where the sheet has conductivity σ and thickness d. A modern derivation of the theory, employing the magnetic scalar potential, is also presented, with explicit use of the uniqueness theorem. Also discussed are limitations on the theory of which Maxwell, living in a time before the discovery of the electron, could not have been aware. Previous derivations either have not appealed explicitly to the uniqueness theorem, or have employed the now unfamiliar current function, and are therefore either incomplete or inaccessible to the modern reader. After the derivation, two important examples considered by Maxwell are presented-a monopole moving above a thin conducting sheet, and a monopole above a rotating thin conducting sheet (Arago's disk)-and it is argued that the lift force thus obtained makes Maxwell the grandfather, if not the father, of eddy current MAGLEV transportation systems. An energy conservation argument is given to derive Davis's result that, for a magnet of arbitrary size and shape moving parallel to a thin conducting sheet at a characteristic height h, with velocity v, the ratio of drag force to lift force is equal to v0/v, provided that d≪δc, where δc =√2h/(μ0σv). If d≫δc, the eddy currents are confined to a thickness δc, leading to an increase in the dissipation and the drag by a factor of d/δc, so that the ratio of drag to lift force becomes proportional to √v'0/v, where v'0 = 2/(μ0σh). The case of a monopole fixed in position, but oscillating in strength (such as can be simulated by one end of a long, narrow, ac solenoid), is also treated. This is employed to obtain the results for an oscillating magnetic dipole whose moment is normal to the sheet. A general discussion of electromagnetic induction and electrical conductors, both thick and thin, is given, emphasizing the difference between the high-frequency limit, where flux expulsion occurs and the self-inductance dominates, and the low-frequency limit, where the flux penetrates and the electrical resistance dominates. A discussion of Lenz's law, as a statement about motion, is given. It is argued that the most general form of such a statement of Lenz's law is that induced currents tend to accelerate a conductor in the direction that most effectively decreases the rate of Joule heating. A calculation, in the low-frequency limit, of the drag force on a magnetic dipole falling down a long conducting tube, is also given. This last case can be given a striking demonstration with the newly available neodymium-iron-boron magnets.

Deposition Of Thin-Film Sensors On Glass-Fiber/Epoxy Models

NASA Technical Reports Server (NTRS)

Tran, Sang Q.

1995-01-01

Direct-deposition process devised for fabrication of thin-film sensors on three-dimensional, curved surfaces of models made of stainless steel covered with glass-fiber/epoxy-matrix composite material. Models used under cryogenic conditions, and sensors used to detect on-line transitions between laminar and turbulent flows in wind tunnel environments. Sensors fabricated by process used at temperatures from minus 300 degrees F to 175 degrees F.

Formation of thin-film resistors on silicon substrates

DOEpatents

Schnable, George L.; Wu, Chung P.

1988-11-01

The formation of thin-film resistors by the ion implantation of a metallic conductive layer in the surface of a layer of phosphosilicate glass or borophosphosilicate glass which is deposited on a silicon substrate. The metallic conductive layer materials comprise one of the group consisting of tantalum, ruthenium, rhodium, platinum and chromium silicide. The resistor is formed and annealed prior to deposition of metal, e.g. aluminum, on the substrate.

Method and apparatus for laser scribing glass sheet substrate coatings

DOEpatents

Borgeson, Frank A.; Hanak, Joseph J.; Harju, Ricky S.; Helman, Norman L.; Hecht, Kenneth R.

2003-05-06

A method and apparatus (42) for laser scribing coatings on glass sheet substrates by conveying the substrate adjacent a laser source (83) that provides a pulsed laser beam (84) with a wavelength at a near-infrared fundamental frequency and having a frequency in the range of 50 to 100 kilohertz and a pulse duration in the range of 8 to 70 nanoseconds, and by reflecting the beam by an XYZ galvanometer controlled mirror system (90) toward an uncoated surface of the substrate for passage therethrough to the coating on the other surface to provide overlapping ablations through the coating and scribing at a speed of at least 1000 millimeters per second.

Method and apparatus for laser scribing glass sheet substrate coatings

DOEpatents

Borgeson, Frank A.; Hanak, Joseph J.; Harju, Ricky S.; Harju, Karen M.; Helman, Norman L.; Hecht, Kenneth R.

2005-07-19

A method and apparatus (42) for laser scribing coatings on glass sheet substrates by conveying the substrate adjacent a laser source (83) that provides a pulsed laser beam (84) with a wavelength at a near-infrared fundamental frequency and having a frequency in the range of 50 to 100 kilohertz and a pulse duration in the range of 8 to 70 nanoseconds, and by reflecting the beam by an XYZ galvanometer controlled mirror system (90) toward an uncoated surface of the substrate for passage therethrough to the coating on the other surface to provide overlapping ablations through the coating and scribing at a speed of at least 1000 millimeters per second.

RGB and white-emitting organic lasers on flexible glass.

PubMed

Foucher, C; Guilhabert, B; Kanibolotsky, A L; Skabara, P J; Laurand, N; Dawson, M D

2016-02-08

Two formats of multiwavelength red, green and blue (RGB) laser on mechanically-flexible glass are demonstrated. In both cases, three all-organic, vertically-emitting distributed feedback (DFB) lasers are assembled onto a common ultra-thin glass membrane substrate and fully encapsulated by a thin polymer overlayer and an additional 50 µm-thick glass membrane in order to improve the performance. The first device format has the three DFB lasers sitting next to each other on the glass substrate. The DFB lasers are simultaneously excited by a single overlapping optical pump, emitting spatially separated red, green and blue laser output with individual thresholds of, respectively, 28 µJ/cm(2), 11 µJ/cm(2) and 32 µJ/cm(2) (for 5 ns pump pulses). The second device format has the three DFB lasers, respectively the red, green and blue laser, vertically stacked onto the flexible glass. This device format emits a white laser output for an optical pump fluence above 42 µJ/cm(2).

Light Management in Flexible Glass by Wood Cellulose Coating

PubMed Central

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

2014-01-01

Ultra-thin flexible glass with high transparency is attractive for a broad range of display applications; however, substrates with low optical haze are not ideal for thin film solar cells, since most of the light will go through the semiconductor layer without scattering, and the length of light travelling path in the active layer is small. By simply depositing a layer of TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical)-oxidized wood fibers (TOWFs), we are able to tailor the optical properties of flexible glass dramatically from exhibiting low haze (<1%) to high haze (~56%) without compromising the total forward transmittance (~90%). The influence of the TOWFs morphology on the optical properties of TOWFs-coated flexible glass is investigated. As the average fiber length decreases, the transmission haze of TOWF-coated flexible glass illustrates a decreasing trend. Earth-abundant natural materials for transparent, hazy, and flexible glass have tremendous applicability in the fabrication of flexible optoelectronics with tunable light scattering effects by enabling inexpensive and large-scale processes. PMID:25068486

Introducing cellulose nanocrystals in sheet molding compounds (SMC)

Treesearch

Amir Asadi; Mark Miller; Sanzida Sultana; Robert J. Moon; Kyriaki Kalaitzidou

2016-01-01

The mechanical properties of short glass fiber/epoxy composites containing cellulose nanocrystals (CNC) made using sheet molding compound (SMC) manufacturing method as well as the rheological and thermomechanical properties of the CNC-epoxy composites were investigated as a function of the CNC content. CNC up to 1.4 wt% were dispersed in the epoxy to produce the resin...

The twin cell model and its excellence in determining the glass transition temperature of thin film metallic glass

NASA Astrophysics Data System (ADS)

Kanjilal, Baishali; Iram, Samreen; Das, Atreyee; Chakrabarti, Haimanti

2018-05-01

This work reports a novel two dimensional approach to the theoretical computation of the glass transition temperature in simple hypothetical icosahedral packed structures based on Thin Film metallic glasses using liquid state theories in the realm of transport properties. The model starts from Navier-Stokes equation and evaluates the statistical average velocity of each different species of atom under the condition of ensemble equality to compute diffusion lengths and the diffusion coefficients as a function of temperature. The additional correction brought in is that of the limited states due to tethering of one nodule vis -a-vis the others. The movement of the molecules use our Twin Cell Model a typical model pertinent for modeling chain motions. A temperature viscosity correction by Cohen and Grest is included through the temperature dependence of the relaxation times for glass formers.

Examining metallic glass formation in LaCe:Nb by ion implantation

DOE PAGES

Sisson, Richard; Reinhart, Cameron; Bridgman, Paul; ...

2017-01-01

In order to combine niobium (Nb) with lanthanum (La) and cerium (Ce), Nb ions were deposited within a thin film of these two elements. According to the Hume-Rothery rules, these elements cannot be combined into a traditional crystalline metallic solid. The creation of an amorphous metallic glass consisting of Nb, La, and Ce is then investigated. Amorphous metallic glasses are traditionally made using fast cooling of a solution of molten metals. In this paper, we show the results of an experiment carried out to form a metallic glass by implanting 9 MeV Nb 3+ atoms into a thin film ofmore » La and Ce. Prior to implantation, the ion volume distribution is calculated by Monte Carlo simulation using the SRIM tool suite. As a result, using multiple methods of electron microscopy and material characterization, small quantities of amorphous metallic glass are indeed identified.« less

Magnetic glass-film based on single-nanosize 𝜺 -Fe2O3 nanoparticles

NASA Astrophysics Data System (ADS)

Yoshikiyo, Marie; Namai, Asuka; Nakagawa, Kosuke; Ohkoshi, Shin-ichi

2017-05-01

We report a magnetic thin film of single-nanosize ɛ-Fe2O3 in SiO2 matrix. The glass-film was prepared by sintering a silica coated iron oxide hydroxide on a quartz substrate in air. The glass-film consists of ɛ-Fe2O3 of 8.8 nm size, and its thickness was 570 nm (0.57 μm) with a roughness of 10 nm (0.01 μm). UV-vis spectrum showed that the glass-film has small absorbance of 0.043 at 500 nm. The magneto-optical effect was investigated, and Faraday ellipticity showed a magnetic hysteresis loop with a coercive field of 3.0 ± 0.2 kOe. Furthermore, single-nanosize ɛ-Fe2O3 without silica was prepared as a reference sample, and ferroelectricity was observed. Therefore, the present thin glass-film consists of single-nanosize ferroelectric-ferromagnetic nanoparticles.

Improving the properties of zinc oxide thin-film surface acoustic wave device on glass substrate by introducing double alumina layers

NASA Astrophysics Data System (ADS)

Shih, Wen-Ching; Huang, Yi-Fan; Wu, Mu-Shiang

2017-10-01

ZnO films with c-axis (0002) orientation have been successfully grown by RF magnetron sputtering on Al2O3/glass substrates. The alumina films were firstly deposited on glass substrates, and then secondly deposited on interdigital transducer/ZnO film/alumina film/glass substrates by electron beam evaporation. The crystalline structure and surface roughness of the films were investigated by X-ray diffraction and atomic force microscopy, respectively. The phase velocity and coupling coefficient of the surface acoustic wave (SAW) device were both increased when we deposited the double alumina layers. On the other hand, the temperature coefficient of frequency becomes better if we increase the thickness of the lower alumina film. The experimental result is beneficial for improving the performance of the ZnO thin-film SAW devices on inexpensive glass substrates.

Evidence for synchronous thin-skinned and basement deformation in the Cordilleran fold-thrust belt: the Tendoy Mountains, southwestern Montana

NASA Astrophysics Data System (ADS)

McDowell, Robin John

1997-01-01

The Tendoy Mountains contain the easternmost thin-skinned thrust sheets in the Cordilleran fold-thrust belt of southwestern Montana, and are in the zone of tectonic overlap between the Rocky Mountain foreland and the Cordilleran fold-thrust belt. The three frontal thrust sheets of the Tendoy Mountains are from north to south, the Armstead, McKenzie, and Tendoy sheets. Near the southeastern terminus of the Tendoy thrust sheet is a lateral ramp in which the Tendoy thrust climbs along strike from the Upper Mississippian Lombard Limestone to lower Cretaceous rocks. This ramp coincides with the southeastern side of the Paleozoic Snowcrest trough and projection of the range-flanking basement thrust of the Blacktail-Snowcrest uplift, suggesting either basement or stratigraphic control on location of the lateral ramp. Axes of major folds on the southern part of the Tendoy thrust sheet are parallel to the direction of thrust transport and to the trend of the Snowcrest Range. They are a result of: (1) Pre-thrust folding above basement faults; (2) Passive transportation of the folds from a down-plunge position; (3) Minor reactivation of basement faults; and (4) Emplacement of blind, sub-Tendoy, thin-skinned thrust faults. The Tendoy sheet also contains a major out-of-sequence thrust fault that formed in thick Upper Mississippian shales and created large, overturned, foreland-verging folds in Upper Mississippian to Triassic rocks. The out-of-sequence fault can be identified where stratigraphic section is omitted, and by a stratigraphic separation diagram that shows it cutting down section in the direction of transport. The prominent lateral ramp at the southern terminus of the Tendoy thrust sheet is a result of fault propagation through strata folded over the edge of the Blacktail-Snowcrest uplift.

Simultaneous measurements of magnetotail dynamics by IMP spacecraft

NASA Technical Reports Server (NTRS)

Fairfield, D. H.; Lepping, R. P.; Hones, E. W., Jr.; Bame, S. J.; Asbridge, J. R.

1980-01-01

Changes in tail energy density during substorms in the magnetotail are given. In addition to plasma sheet thinnings seen prior to substorm onsets, a gradual decrease in plasma beta was detected in the deep tail which precedes onset and the more prominent plasma disappearance that typically accompanies it. The frequency of thinnings and the regions over which they occurred indicate that drastic changes in plasma sheet thickness are common features of substorms which occur at all locations across the tail.

Method of using sacrificial materials for fabricating internal cavities in laminated dielectric structures

DOEpatents

Peterson, Kenneth A [Albuquerque, NM

2009-02-24

A method of using sacrificial materials for fabricating internal cavities and channels in laminated dielectric structures, which can be used as dielectric substrates and package mounts for microelectronic and microfluidic devices. A sacrificial mandrel is placed in-between two or more sheets of a deformable dielectric material (e.g., unfired LTCC glass/ceramic dielectric), wherein the sacrificial mandrel is not inserted into a cutout made in any of the sheets. The stack of sheets is laminated together, which deforms the sheet or sheets around the sacrificial mandrel. After lamination, the mandrel is removed, (e.g., during LTCC burnout), thereby creating a hollow internal cavity in the monolithic ceramic structure.

Further improvements in conducting and transparent properties of ZnO:Ga films with perpetual c-axis orientation: Materials optimization and application in silicon solar cells

NASA Astrophysics Data System (ADS)

Mondal, Praloy; Das, Debajyoti

2017-07-01

Technologically appropriate device friendly ZnO:Ga films have been prepared at a low growth temperature (100 °C) by changing the RF power (P) applied to the magnetron plasma. Structurally preferred c-axis orientation of the ZnO:Ga network has been attained with I〈002〉/I〈103〉 > 5. The c-axis oriented grains of wurtzite ZnO:Ga grows geometrically and settles in tangentially, providing favorable conduction path for stacked layer devices. Nano-sheet like structures produced at the surface are interconnected and provide conducting path across the surface; however, those accommodate a lot of pores in between that help better light trapping and reduce the reflection loss. The optimized ZnO:Ga thin film prepared at RF power of 200 W has 〈002〉 oriented grains of average size ∼10 nm and exhibits a very high conductivity ∼200 S cm-1 and elevated transmission (∼93% at 500 nm) in the visible range. The optimized ZnO:Ga film has been used as the transparent conducting oxide (TCO) window layer of RF-PECVD grown silicon thin film solar cells in glass/TCO/p-i-n-Si/Al configuration. The characteristics of identically prepared p-i-n-Si solar cells are compared by replacing presently developed ZnO:Ga TCO with the best quality U-type SnO2 coated Asahi glass substrates. The ZnO:Ga coated glass substrate offers a higher open circuit voltage (VOC) and the higher fill factor (FF). The ZnO:Ga film being more stable in hydrogen plasma than its SnO2 counterpart, maintains a high transparency to the solar radiation and improves the VOC, while reduced diffusion of Zn across the p-layer creates less defects at the p-i interface in Si:H cells and thereby, increases the FF. Nearly identical conversion efficiency is preserved for both TCO substrates. Excellent c-axis orientation even at low growth temperature promises improved device performance by extended parametric optimization.

Amorphous silicon thin films: The ultimate lightweight space solar cell

NASA Technical Reports Server (NTRS)

Vendura, G. J., Jr.; Kruer, M. A.; Schurig, H. H.; Bianchi, M. A.; Roth, J. A.

1994-01-01

Progress is reported with respect to the development of thin film amorphous (alpha-Si) terrestrial solar cells for space applications. Such devices promise to result in very lightweight, low cost, flexible arrays with superior end of life (EOL) performance. Each alpha-Si cell consists of a tandem arrangement of three very thin p-i-n junctions vapor deposited between film electrodes. The thickness of this entire stack is approximately 2.0 microns, resulting in a device of negligible weight, but one that must be mechanically supported for handling and fabrication into arrays. The stack is therefore presently deposited onto a large area (12 by 13 in), rigid, glass superstrate, 40 mil thick, and preliminary space qualification testing of modules so configured is underway. At the same time, a more advanced version is under development in which the thin film stack is transferred from the glass onto a thin (2.0 mil) polymer substrate to create large arrays that are truly flexible and significantly lighter than either the glassed alpha-Si version or present conventional crystalline technologies. In this paper the key processes for such effective transfer are described. In addition, both glassed (rigid) and unglassed (flexible) alpha-Si cells are studied when integrated with various advanced structures to form lightweight systems. EOL predictions are generated for the case of a 1000 W array in a standard, 10 year geosynchronous (GEO) orbit. Specific powers (W/kg), power densities (W/sq m) and total array costs ($/sq ft) are compared.

Numerical analysis of tailored sheets to improve the quality of components made by SPIF

NASA Astrophysics Data System (ADS)

Gagliardi, Francesco; Ambrogio, Giuseppina; Cozza, Anna; Pulice, Diego; Filice, Luigino

2018-05-01

In this paper, the authors pointed out a study on the profitable combination of forming techniques. More in detail, the attention has been put on the combination of the single point incremental forming (SPIF) and, generally, speaking, of an additional process that can lead to a material thickening on the initial blank considering the local thinning which the sheets undergo at. Focalizing the attention of the research on the excessive thinning of parts made by SPIF, a hybrid approach can be thought as a viable solution to reduce the not homogeneous thickness distribution of the sheet. In fact, the basic idea is to work on a blank previously modified by a deformation step performed, for instance, by forming, additive or subtractive processes. To evaluate the effectiveness of this hybrid solution, a FE numerical model has been defined to analyze the thickness variation on tailored sheets incrementally formed optimizing the material distribution according to the shape to be manufactured. Simulations based on the explicit formulation have been set up for the model implementation. The mechanical properties of the sheet material have been taken in literature and a frustum of cone as benchmark profile has been considered for the performed analysis. The outcomes of numerical model have been evaluated in terms of both maximum thinning and final thickness distribution. The feasibility of the proposed approach will be deeply detailed in the paper.

Prototypical model for tensional wrinkling in thin sheets

PubMed Central

Davidovitch, Benny; Schroll, Robert D.; Vella, Dominic; Adda-Bedia, Mokhtar; Cerda, Enrique A.

2011-01-01

The buckling and wrinkling of thin films has recently seen a surge of interest among physicists, biologists, mathematicians, and engineers. This activity has been triggered by the growing interest in developing technologies at ever-decreasing scales and the resulting necessity to control the mechanics of tiny structures, as well as by the realization that morphogenetic processes, such as the tissue-shaping instabilities occurring in animal epithelia or plant leaves, often emerge from mechanical instabilities of cell sheets. Although the most basic buckling instability of uniaxially compressed plates was understood by Euler more than two centuries ago, recent experiments on nanometrically thin (ultrathin) films have shown significant deviations from predictions of standard buckling theory. Motivated by this puzzle, we introduce here a theoretical model that allows for a systematic analysis of wrinkling in sheets far from their instability threshold. We focus on the simplest extension of Euler buckling that exhibits wrinkles of finite length—a sheet under axisymmetric tensile loads. The first study of this geometry, which is attributed to Lamé, allows us to construct a phase diagram that demonstrates the dramatic variation of wrinkling patterns from near-threshold to far-from-threshold conditions. Theoretical arguments and comparison to experiments show that the thinner the sheet is, the smaller is the compressive load above which the far-from-threshold regime emerges. This observation emphasizes the relevance of our analysis for nanomechanics applications. PMID:22042841

Detection of defects in formed sheet metal using medial axis transformation

NASA Astrophysics Data System (ADS)

Murmu, Naresh C.; Velgan, Roman

2003-05-01

In the metal forming processes, the sheet metals are often prone to various defects such as thinning, dents, wrinkles etc. In the present manufacturing environments with ever increasing demand of higher quality, detecting the defects of formed sheet metal using an effective and objective inspection system is the foremost norm to remain competitive in market. The defect detection using optical techniques aspire to satisfy its needs to be non-contact and fast. However, the main difficulties to achieve this goal remain essentially on the development of efficient evaluation technique and accurate interpretation of extracted data. The defect like thinning is detected by evaluating the deviations of the thickness in the formed sheet metal against its nominal value. The present evaluation procedure for determination of thickness applied on the measurements data is not without deficiency. To improve this procedure, a new evaluation approach based on medial axis transformation is proposed here. The formed sheet metals are digitized using fringe projection systems in different orientations, and afterwards registered into one coordinate frame. The medial axis transformation (MAT) is applied on the point clouds, generating the point clouds of MAT. This data is further processed and medial surface is determined. The thinning defect is detected by evaluating local wall thickness and other defects like wrinkles are determined using the shape recognition on the medial surface. The applied algorithm is simple, fast and robust.

A Novel Light Trapping Phenomenon in Fluid Media.

ERIC Educational Resources Information Center

Devlin, J. C.; Tolles, W. M.

1979-01-01

Describes an experiment on light trapping in thin liquid films. Injection of a thin layer of solution at the boundary of a moving solvent is utilized to create a thin fluid sheet having an index of refraction greater than that of the surrounding medium. (Author/SA)

Ultra-thin grain-oriented silicon steel sheet fabricated by a novel way: Twin-roll strip casting and two-stage cold rolling

NASA Astrophysics Data System (ADS)

Wang, Yin-Ping; Liu, Hai-Tao; Song, Hong-Yu; Liu, Jia-Xin; Shen, Hui-Ying; Jin, Yang; Wang, Guo-Dong

2018-04-01

0.05-0.15 mm-thick ultra-thin grain-oriented silicon steel sheets were successfully produced by a novel processing route including strip casting, hot rolling, normalizing, two-stage cold rolling with intermediate annealing, primary recrystallization annealing and secondary recrystallization annealing. The evolutions of microstructure, texture and inhibitor along the processing were briefly investigated. The results showed that the initial Goss orientation originated due to the heterogenous nucleation of δ-ferrite grains during solidification. Because of the lack of shear deformation, only a few Goss grains were observed in the hot rolled sheet. After the first cold rolling and intermediate annealing, Goss texture was enhanced and distributed in the whole thickness. A small number of Goss grains having a high fraction of high energy boundaries exhibited in the primary recrystallization annealed sheet. A large number of fine and dispersed MnS and AlN and a few co-precipitates MnS and AlN with the size range of 10-70 nm were also observed. Interestingly, a well-developed secondary recrystallization microstructure characterized by 10-60 mm grains and a sharp Goss texture were finally produced in the 0.05-0.15 mm-thick ultra-thin sheets. A magnetic induction B8 of 1.72-1.84 T was obtained. Another new finding was that a few {2 3 0}〈0 0 1〉 and {2 1 0}〈1 2 7〉 grains also can grow up abnormally because of the high fraction of high energy boundaries and the size and number advantage, respectively. These non-Goss grains finally deteriorated the magnetic properties of the ultra-thin sheets. In addition, low surface energies of {hk0} planes may also contribute to the abnormal growth of Goss, {2 3 0}〈0 0 1〉 and {2 1 0}〈1 2 7〉 grains.

Local processes and regional patterns - Interpreting a multi-decadal altimetry record of Greenland Ice Sheet changes

NASA Astrophysics Data System (ADS)

Csatho, B. M.; Schenk, A. F.; Babonis, G. S.; van den Broeke, M. R.; Kuipers Munneke, P.; van der Veen, C. J.; Khan, S. A.; Porter, D. F.

2016-12-01

This study presents a new, comprehensive reconstruction of Greenland Ice Sheet elevation changes, generated using the Surface Elevation And Change detection (SERAC) approach. 35-year long elevation-change time series (1980-2015) were obtained at more than 150,000 locations from observations acquired by NASA's airborne and spaceborne laser altimeters (ATM, LVIS, ICESat), PROMICE laser altimetry data (2007-2011) and a DEM covering the ice sheet margin derived from stereo aerial photographs (1970s-80s). After removing the effect of Glacial Isostatic Adjustment (GIA) and the elastic crustal response to changes in ice loading, the time series were partitioned into changes due to surface processes and ice dynamics and then converted into mass change histories. Using gridded products, we examined ice sheet elevation, and mass change patterns, and compared them with other estimates at different scales from individual outlet glaciers through large drainage basins, on to the entire ice sheet. Both the SERAC time series and the grids derived from these time series revealed significant spatial and temporal variations of dynamic mass loss and widespread intermittent thinning, indicating the complexity of ice sheet response to climate forcing. To investigate the regional and local controls of ice dynamics, we examined thickness change time series near outlet glacier grounding lines. Changes on most outlet glaciers were consistent with one or more episodes of dynamic thinning that propagates upstream from the glacier terminus. The spatial pattern of the onset, duration, and termination of these dynamic thinning events suggest a regional control, such as warming ocean and air temperatures. However, the intricate spatiotemporal pattern of dynamic thickness change suggests that, regardless of the forcing responsible for initial glacier acceleration and thinning, the response of individual glaciers is modulated by local conditions. We use statistical methods, such as principal component analysis and multivariate regression to analyze the dynamic ice-thickness change time series derived by SERAC and to investigate the primary forcings and controls on outlet glacier changes.

Hard X-ray mirrors for Nuclear Security

DOE Office of Scientific and Technical Information (OSTI.GOV)

Descalle, M. A.; Brejnholt, N.; Hill, R.

Research performed under this LDRD aimed to demonstrate the ability to detect and measure hard X-ray emissions using multilayer X-ray reflective optics above 400 keV, to enable the development of inexpensive and high-accuracy mirror substrates, and to investigate applications of hard X-ray mirrors of interest to the nuclear security community. Experiments conducted at the European Synchrotron Radiation Facility demonstrated hard X-ray mirror reflectivity up to 650 keV for the first time. Hard X-ray optics substrates must have surface roughness under 3 to 4 Angstrom rms, and three materials were evaluated as potential substrates: polycarbonates, thin Schott glass and a newmore » type of flexible glass called Willow Glass®. Chemical smoothing and thermal heating of the surface of polycarbonate samples, which are inexpensive but have poor intrinsic surface characteristics, did not yield acceptable surface roughness. D263 Schott glass was used for the focusing optics of the NASA NuSTAR telescope. The required specialized hardware and process were costly and motivated experiments with a modified non-contact slumping technique. The surface roughness of the glass was preserved and the process yielded cylindrical shells with good net shape pointing to the potential advantage of this technique. Finally, measured surface roughness of 200 and 130 μm thick Willow Glass sheets was between 2 and 2.5 A rms. Additional results of flexibility tests and multilayer deposition campaigns indicated it is a promising substrate for hard X-ray optics. The detection of U and Pu characteristics X-ray lines and gamma emission lines in a high background environment was identified as an area for which X-ray mirrors could have an impact and where focusing optics could help reduce signal to noise ratio by focusing signal onto a smaller detector. Hence the first one twelvetant of a Wolter I focusing optics for the 90 to 140 keV energy range based on aperiodic multilayer coating was designed. Finally, we conducted the first demonstration that reflective multilayer mirrors could be used as diagnostic for HED experiment with an order of magnitude improvement in signal-to-noise ratio for the multilayer optic compared a transmission crystal spectrometer.« less

Aligned carbon nanotube-silicon sheets: a novel nano-architecture for flexible lithium ion battery electrodes.

PubMed

Fu, Kun; Yildiz, Ozkan; Bhanushali, Hardik; Wang, Yongxin; Stano, Kelly; Xue, Leigang; Zhang, Xiangwu; Bradford, Philip D

2013-09-25

Aligned carbon nanotube sheets provide an engineered scaffold for the deposition of a silicon active material for lithium ion battery anodes. The sheets are low-density, allowing uniform deposition of silicon thin films while the alignment allows unconstrained volumetric expansion of the silicon, facilitating stable cycling performance. The flat sheet morphology is desirable for battery construction. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Kelvin-Helmholtz instability of a thin liquid sheet: Effect of the gas-boundary layer

NASA Astrophysics Data System (ADS)

Tirumkudulu, Mahesh

2017-11-01

It is well known that when a thin liquid sheet moves with respect to a surrounding gas phase, the liquid sheet is susceptible to the Kelvin-Helmholtz instability. Here, flow in both the liquid and the gas phases are assumed to be inviscid. In this work, we include exactly via a perturbation analysis, the influence of the growing boundary layer in the gas phase in the base flow and show that both temporal and spatial growth rates obtained from the linear stability analysis are significantly reduced due to the presence of the boundary layer. These results are in line with the simulation results of Lozano et al. and Tammisola et al.. We conclude with the implication of these results on the break-up of radially expanding liquid sheets. Funding from IIT Bombay, CSIR India, and Trinity College, Cambridge University is acknowledged.

A new method for the radiochemical purity measurement of ¹¹¹In-pentetreotide.

PubMed

Salgado-Garcia, Carlos; Montoza-Aguado, Manuel; Luna-Alcaide, Ana B; Segovia-Gonzalez, Maria M; de Mora, Elena Sanchez; Lopez-Martin, Juana; Ramos-Font, Carlos; Jimenez-Heffernan, Amelia

2011-12-01

The recommended method for the measurement of radiochemical purity (RCP) of ¹¹¹In-labelled pentetreotide is thin-layer chromatography with a silica gel as the stationary phase and a 0.1 N sodium citrate solution (pH 5) as the mobile phase. According to the supplier's instructions, the mobile phase must be prepared before the test is carried out, and the recommended stationary phase is off-market. We propose a new method for RCP measurement in which the mobile phase is acid citrate dextrose, solution A, which does not need to be prepared beforehand, and thin-layer chromatography is performed with a silica gel-impregnated glass fibre sheet as the stationary phase. We used both methods to measure the percentages of radiopharmaceutical and impurities. The range of RCP values obtained was 98.0-99.9% (mean=99.3%) by the standard method and 98.1-99.9% (mean=99.2%) by the new method. We observed no differences between the RCP values of both methods (P=0.070). The proposed method is suitable for RCP testing because it yields results that are in good agreement with those of the standard method and because it is easier to perform as the mobile-phase solution need not be prepared in advance.

24 CFR 200.946 - Building product standards and certification program for exterior finish and insulation systems...

Code of Federal Regulations, 2012 CFR

2012-04-01

...) ASTM C-1186-91 Standard Specification for Flat Non-Asbestos Fiber-Cement Sheets. (v) ASTM D 579-90 Standard Specification for Greige Woven Glass Fabrics. (vi) ASTM D 3273-86—(Reapproved 1991) Standard Test... Glass Fiber Reinforcing Mesh for Use in Exterior Insulation and Finish Systems (EIFS), Class PB. (xv...

24 CFR 200.946 - Building product standards and certification program for exterior finish and insulation systems...

Code of Federal Regulations, 2014 CFR

2014-04-01

...) ASTM C-1186-91 Standard Specification for Flat Non-Asbestos Fiber-Cement Sheets. (v) ASTM D 579-90 Standard Specification for Greige Woven Glass Fabrics. (vi) ASTM D 3273-86—(Reapproved 1991) Standard Test... Glass Fiber Reinforcing Mesh for Use in Exterior Insulation and Finish Systems (EIFS), Class PB. (xv...

24 CFR 200.946 - Building product standards and certification program for exterior finish and insulation systems...

Code of Federal Regulations, 2013 CFR

2013-04-01

...) ASTM C-1186-91 Standard Specification for Flat Non-Asbestos Fiber-Cement Sheets. (v) ASTM D 579-90 Standard Specification for Greige Woven Glass Fabrics. (vi) ASTM D 3273-86—(Reapproved 1991) Standard Test... Glass Fiber Reinforcing Mesh for Use in Exterior Insulation and Finish Systems (EIFS), Class PB. (xv...

View forward from stern showing skylight with rippled glass over ...

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

View forward from stern showing skylight with rippled glass over compartment c-110, officer's quarters; note manually operated capstan at center, and simulated eight inch guns in sheet metal mock-up turret; also note five inch guns in sponsons port and starboard. (p37) - USS Olympia, Penn's Landing, 211 South Columbus Boulevard, Philadelphia, Philadelphia County, PA

Effect of different coating layer on the topography and optical properties of ZnO nanostructured

NASA Astrophysics Data System (ADS)

Mohamed, R.; Mamat, M. H.; Malek, M. F.; Ismail, A. S.; Yusoff, M. M.; Asiah, M. N.; Khusaimi, Z.; Rusop, M.

2018-05-01

Magnesium (Mg) and aluminum (Al) co-doped zinc oxide (MAZO) thin films were synthesized on glass substrate by sol-gel spin coating method. MAZO thin films were prepared at different coating layers range from 1 to 9. Atomic Force Microscopy (AFM) was used to investigate the topography of the thin films. According to the AFM results, Root Means Square (RMS) of MAZO thin films was increased from 0.747 to 6.545 nm, with increase of number coating layer from 1 to 9, respectively. The results shown the variation on structural and topography properties of MAZO seed film when it's deposited at different coating layers on glass substrate. The optical properties was analyzed using UV-Vis spectroscopy. The obtained results show that the transmittance spectra was increased as thin films coating layer increases.

Laser readable thermoluminescent radiation dosimeters and methods for producing thereof

DOEpatents

Braunlich, P.F.; Tetzlaff, W.

1989-04-25

Thin layer thermoluminescent radiation dosimeters for use in laser readable dosimetry systems, and methods of fabricating such thin layer dosimeters are disclosed. The thin layer thermoluminescent radiation dosimeters include a thin substrate made from glass or other inorganic materials capable of withstanding high temperatures and high heating rates. A thin layer of a thermoluminescent phosphor material is heat bonded to the substrate using an inorganic binder such as glass. The dosimeters can be mounted in frames and cases for ease in handling. Methods of the invention include mixing a suitable phosphor composition and binder, both being in particulate or granular form. The mixture is then deposited onto a substrate such as by using mask printing techniques. The dosimeters are thereafter heated to fuse and bond the binder and phosphor to the substrate. 34 figs.

Reactive magnetron sputtering of N-doped carbon thin films on quartz glass for transmission photocathode applications

NASA Astrophysics Data System (ADS)

Balalykin, N. I.; Huran, J.; Nozdrin, M. A.; Feshchenko, A. A.; Kobzev, A. P.; Sasinková, V.; Boháček, P.; Arbet, J.

2018-03-01

N-doped carbon thin films were deposited on a silicon substrate and quartz glass by RF reactive magnetron sputtering using a carbon target and an Ar+N2 gas mixture. During the magnetron sputtering, the substrate holder temperatures was kept at 800 °C. The carbon film thickness on the silicon substrate was about 70 nm, while on the quartz glass it was in the range 15 nm – 60 nm. The elemental concentration in the films was determined by RBS and ERD. Raman spectroscopy was used to evaluate the intensity ratios I D/I G of the D and G peaks of the carbon films. The transmission photocathodes prepared were placed in the hollow-cathode assembly of a Pierce-structure DC gun to produce photoelectrons. The quantum efficiency (QE) was calculated from the laser energy and cathode charge measured. The properties of the transmission photocathodes based on semitransparent N-doped carbon thin films on quartz glass and their potential for application in DC gun technology are discussed.

Fabrication of ultrafast laser written low-loss waveguides in flexible As₂S₃ chalcogenide glass tape.

PubMed

Lapointe, Jerome; Ledemi, Yannick; Loranger, Sébastien; Iezzi, Victor Lambin; Soares de Lima Filho, Elton; Parent, Francois; Morency, Steeve; Messaddeq, Younes; Kashyap, Raman

2016-01-15

As2S3 glass has a unique combination of optical properties, such as wide transparency in the infrared region and a high nonlinear coefficient. Recently, intense research has been conducted to improve photonic devices using thin materials. In this Letter, highly uniform rectangular single-index and 2 dB/m loss step-index optical tapes have been drawn by the crucible technique. Low-loss (<0.15  dB/cm) single-mode waveguides in chalcogenide glass tapes have been fabricated using femtosecond laser writing. Optical backscatter reflectometry has been used to study the origin of the optical losses. A detailed study of the laser writing process in thin glass is also presented to facilitate a repeatable waveguide inscription recipe.

Method for forming glass-to-metal seals

DOEpatents

Kramer, Daniel P.; Massey, Richard T.

1986-01-01

A method for forming a glass-to-metal seal in which the glass has a higher melting point than the metal. The molten glass is vacuum injection molded onto the metal, thus melting a very thin layer of the surface of the metal long enough to form a seal, but not long enough to cause a distortion in the shape of the metal component.

Recent Observations of Increased Thinning of the Greenland Ice Sheet Measured by Aircraft GPS and Laser Altimetry

NASA Technical Reports Server (NTRS)

Krabill, William B.

2004-01-01

The Arctic Ice Mapping group (Project AIM) at the NASA Goddard Space Flight Center Wallops Flight Facility has been conducting systematic topographic surveys of the Greenland Ice Sheet (GIs) since 1993, using scanning airborne laser altimeters combined with Global Positioning System (GPS) technology onboard NASA's P-3 aircraft. Flight lines have covered all major ice drainage basins, with repeating surveys after a 5-year interval during the decade of the 90's. Analysis of this data documented significant thinning in many areas near the ice sheet margins and an overall negative mass balance of the GIS (Science, 2000). In 2001, 2002, and 2003 many of these flight lines were re-surveyed, providing evidence of continued or accelerated thinning in all observed areas around the margin of the GIs. Additionally, however, a highly-anomalous snowfall was observed between 2002 and 2003 in SE Greenland - perhaps an indicator of a shift in the regional climate?

Scaling results for the Liquid Sheet Radiator (LSR)

NASA Technical Reports Server (NTRS)

Chubb, Donald L.; Calfo, Frederick D.

1989-01-01

Surface tension forces at the edges of a thin liquid (approx. 100 micrometers) sheet flow result in a triangularly shaped sheet. Such a geometry is ideal for an external flow radiator. The experimental investigation of such sheet flows was extended to large sheets (width = W = 23.5 cm, length = L approx. = 3.5 m). Experimental L/W results are greater than the calculated results. However, more experimental results are necessary for a complete comparison. The calculated emissivity of a sheet of Dow-Corning 705 silicone oil, which is a low temperature (300 to 400K) candidate for a liquid sheet radiator (LSR), is greater than .8 for sheet thicknesses greater than 100 micrometers.

Stress focusing and collapse of a thin film under constant pressure

NASA Astrophysics Data System (ADS)

Hamm, Eugenio; Cabezas, Nicolas

2012-02-01

Thin elastic sheets and shells are prone to focus stress when forced, due to their near inextensibility. Singular structures such as ridges, vertices, and folds arising from wrinkles, are characteristic of the deformation of such systems. Usually the forcing is exerted at the boundaries or at specific points of the surface, in displacement controlled experiments. On the other hand, much of the phenomenology of stress focusing can be found at micro and nanoscales, in physics and biology, making it universal. We will consider the post-buckling regime of a thin elastic sheet that is subjected to a constant normal distributed force. Specifically, we will present experiments made on thin elastoplastic sheets that collapse under atmospheric pressure. For instance, in vacuum-sealing technology, when a flat plastic bag is forced to wrap a solid volume, a series of self-contacts and folds develop. The unfolded bag shows a pattern of scars whose structure is determined by the geometry of the volume and by the exact way it stuck to its surface, by friction. Inspired by this everyday example we study the geometry of folds that result from collapsing a hermetic bag on regular rigid bodies.

Multi-layered fabrication of large area PDMS flexible optical light guide sheets

NASA Astrophysics Data System (ADS)

Green, Robert; Knopf, George K.; Bordatchev, Evgueni V.

2017-02-01

Large area polydimethylsiloxane (PDMS) flexible optical light guide sheets can be used to create a variety of passive light harvesting and illumination systems for wearable technology, advanced indoor lighting, non-planar solar light collectors, customized signature lighting, and enhanced safety illumination for motorized vehicles. These thin optically transparent micro-patterned polymer sheets can be draped over a flat or arbitrarily curved surface. The light guiding behavior of the optical light guides depends on the geometry and spatial distribution of micro-optical structures, thickness and shape of the flexible sheet, refractive indices of the constituent layers, and the wavelength of the incident light. A scalable fabrication method that combines soft-lithography, closed thin cavity molding, partial curing, and centrifugal casting is described in this paper for building thin large area multi-layered PDMS optical light guide sheets. The proposed fabrication methodology enables the of internal micro-optical structures (MOSs) in the monolithic PDMS light guide by building the optical system layer-by-layer. Each PDMS layer in the optical light guide can have the similar, or a slightly different, indices of refraction that permit total internal reflection within the optical sheet. The individual molded layers may also be defect free or micro-patterned with microlens or reflecting micro-features. In addition, the bond between adjacent layers is ensured because each layer is only partially cured before the next functional layer is added. To illustrate the scalable build-by-layers fabrication method a three-layer mechanically flexible illuminator with an embedded LED strip is constructed and demonstrated.

Electro-thermo-mechanical coupling analysis of deep drawing with resistance heating for aluminum matrix composites sheet

NASA Astrophysics Data System (ADS)

Zhang, Kaifeng; Zhang, Tuoda; Wang, Bo

2013-05-01

Recently, electro-plastic forming to be a focus of attention in materials hot processing research area, because it is a sort of energy-saving, high efficient and green manufacturing technology. An electro-thermo-mechanical model can be adopted to carry out the sequence simulation of aluminum matrix composites sheet deep drawing via electro-thermal coupling and thermal-mechanical coupling method. The first step of process is resistance heating of sheet, then turn off the power, and the second step is deep drawing. Temperature distribution of SiCp/2024Al composite sheet by resistance heating and sheet deep drawing deformation were analyzed. During the simulation, effect of contact resistances, temperature coefficient of resistance for electrode material and SiCp/2024Al composite on temperature distribution were integrally considered. The simulation results demonstrate that Sicp/2024Al composite sheet can be rapidly heated to 400° in 30s using resistances heating and the sheet temperature can be controlled by adjusting the current density. Physical properties of the electrode materials can significantly affect the composite sheet temperature distribution. The temperature difference between the center and the side of the sheet is proportional to the thermal conductivity of the electrode, the principal cause of which is that the heat transfers from the sheet to the electrode. SiCp/2024Al thin-wall part can be intactly manufactured at strain rate of 0.08s-1 and the sheet thickness thinning rate is limited within 20%, which corresponds well to the experimental result.

Gravity Survey on the Glass Buttes Geothermal Exploration Project Lake County, Oregon

DOE Data Explorer

John Akerley

2011-10-12

This report covers data acquisition, instrumentation and processing of a gravity survey performed on the Glass Buttes Geothermal Exploration Project, located in Lake County, Oregon for ORMAT Technologies Inc. The survey was conducted during 21 June 2010 to 26 June 2010. The survey area is located in T23S, R21-23E and lies within the Glass Buttes, Hat Butte, and Potato Lake, Oregon 1:24,000 topographic sheets. A total of 180 gravity stations were acquired along five profile lines.

Insulation Blankets for High-Temperature Use

NASA Technical Reports Server (NTRS)

Goldstein, H.; Leiser, D.; Sawko, P. M.; Larson, H. K.; Estrella, C.; Smith, M.; Pitoniak, F. J.

1986-01-01

Insulating blanket resists temperatures up to 1,500 degrees F (815 degrees C). Useful where high-temperature resistance, flexibility, and ease of installation are important - for example, insulation for odd-shaped furnaces and high-temperature ducts, curtains for furnace openings and fire control, and conveyor belts in hot processes. Blanket is quilted composite consisting of two face sheets: outer one of silica, inner one of silica or other glass cloth with center filling of pure silica glass felt sewn together with silica glass threads.

Substrate effects on photoluminescence and low temperature phase transition of methylammonium lead iodide hybrid perovskite thin films

NASA Astrophysics Data System (ADS)

Shojaee, S. A.; Harriman, T. A.; Han, G. S.; Lee, J.-K.; Lucca, D. A.

2017-07-01

We examine the effects of substrates on the low temperature photoluminescence (PL) spectra and phase transition in methylammonium lead iodide hybrid perovskite (CH3NH3PbI3) thin films. Structural characterization at room temperature with X-ray diffraction (XRD), scanning electron microscopy (SEM), and Raman spectroscopy indicated that while the chemical structure of films deposited on glass and quartz was similar, the glass substrate induced strain in the perovskite films and suppressed the grain growth. The luminescence response and phase transition of the perovskite thin films were studied by PL spectroscopy. The induced strain was found to affect both the room temperature and low temperature PL spectra of the hybrid perovskite films. In addition, it was found that the effects of the glass substrate inhibited a tetragonal to orthorhombic phase transition such that it occurred at lower temperatures.

Determining the Elastic Modulus of Compliant Thin Films Supported on Substrates from Flat Punch Indentation Measurements

Treesearch

M.J. Wald; J.M. Considine; K.T. Turner

2013-01-01

Instrumented indentation is a technique that can be used to measure the elastic properties of soft thin films supported on stiffer substrates, including polymer films, cellulosic sheets, and thin layers of biological materials. When measuring thin film properties using indentation, the effect of the substrate must be considered. Most existing models for determining the...

Structure, Mechanics and Synthesis of Nanoscale Carbon and Boron Nitride

NASA Astrophysics Data System (ADS)

Rinaldo, Steven G.

This thesis is divided into two parts. In Part I, we examine the properties of thin sheets of carbon and boron nitride. We begin with an introduction to the theory of elastic sheets, where the stretching and bending modes are considered in detail. The coupling between stretching and bending modes is thought to play a crucial role in the thermodynamic stability of atomically-thin 2D sheets such as graphene. In Chapter 2, we begin by looking at the fabrication of suspended, atomically thin sheets of graphene. We then study their mechanical resonances which are read via an optical transduction technique. The frequency of the resonators was found to depend on their temperature, as was their quality factor. We conclude by offering some interpretations of the data in terms of the stretching and bending modes of graphene. In Chapter 3, we look briefly at the fabrication of thin sheets of carbon and boron nitride nanotubes. We examine the structure of the sheets using transmission and scanning electron microscopy (TEM and SEM, respectively). We then show a technique by which one can make sheets suspended over a trench with adjustable supports. Finally, DC measurements of the resistivity of the sheets in the temperature range 600 -- 1400 C are presented. In Chapter 4, we study the folding of few-layer graphene oxide, graphene and boron nitride into 3D aerogel monoliths. The properties of graphene oxide are first considered, after which the structure of graphene and boron nitride aerogels is examined using TEM and SEM. Some models for their structure are proposed. In Part II, we look at synthesis techniques for boron nitride (BN). In Chapter 5, we study the conversion of carbon structures of boron nitride via the application of carbothermal reduction of boron oxide followed by nitridation. We apply the conversion to a wide variety of morphologies, including aerogels, carbon fibers and nanotubes, and highly oriented pyrolytic graphite. In the latter chapters, we look at the formation of boron nitride nanotubes (BNNTs). In Chapter 6, we look at various methods of producing BNNTs from boron droplets, and introduce a new method involving injection of boron powder into an induction furnace. In Chapter 7 we consider another useful process, where ammonia is reacted with boron vapor generated in situ, either through the reaction of boron with metal oxides or through the decomposition of metal borides.

Atomically thin two-dimensional organic-inorganic hybrid perovskites

NASA Astrophysics Data System (ADS)

Dou, Letian; Wong, Andrew B.; Yu, Yi; Lai, Minliang; Kornienko, Nikolay; Eaton, Samuel W.; Fu, Anthony; Bischak, Connor G.; Ma, Jie; Ding, Tina; Ginsberg, Naomi S.; Wang, Lin-Wang; Alivisatos, A. Paul; Yang, Peidong

2015-09-01

Organic-inorganic hybrid perovskites, which have proved to be promising semiconductor materials for photovoltaic applications, have been made into atomically thin two-dimensional (2D) sheets. We report the solution-phase growth of single- and few-unit-cell-thick single-crystalline 2D hybrid perovskites of (C4H9NH3)2PbBr4 with well-defined square shape and large size. In contrast to other 2D materials, the hybrid perovskite sheets exhibit an unusual structural relaxation, and this structural change leads to a band gap shift as compared to the bulk crystal. The high-quality 2D crystals exhibit efficient photoluminescence, and color tuning could be achieved by changing sheet thickness as well as composition via the synthesis of related materials.

Dependence of lattice strain relaxation, absorbance, and sheet resistance on thickness in textured ZnO@B transparent conductive oxide for thin-film solar cell applications.

PubMed

Kou, Kuang-Yang; Huang, Yu-En; Chen, Chien-Hsun; Feng, Shih-Wei

2016-01-01

The interplay of surface texture, strain relaxation, absorbance, grain size, and sheet resistance in textured, boron-doped ZnO (ZnO@B), transparent conductive oxide (TCO) materials of different thicknesses used for thin film, solar cell applications is investigated. The residual strain induced by the lattice mismatch and the difference in the thermal expansion coefficient for thicker ZnO@B is relaxed, leading to an increased surface texture, stronger absorbance, larger grain size, and lower sheet resistance. These experimental results reveal the optical and material characteristics of the TCO layer, which could be useful for enhancing the performance of solar cells through an optimized TCO layer.

Lightweight sheet molding compound (SMC) composites containing cellulose nanocrystals

Treesearch

Amir Asadi; Mark Miller; Arjun V. Singh; Robert J. Moon; Kyriaki Kalaitzidou

2017-01-01

A scalable technique was introduced to produce high volume lightweight composites using sheet molding compound (SMC) manufacturing method by replacing 10 wt% glass fibers (GF) with a small amount of cellulose nanocrystals (CNC). The incorporation of 1 and 1.5 wt% CNC by dispersing in the epoxy matrix of short GF/epoxy SMC composites with 25 wt% GF content (25GF/CNC-...

Measurement of edge residual stresses in glass by the phase-shifting method

NASA Astrophysics Data System (ADS)

Ajovalasit, A.; Petrucci, G.; Scafidi, M.

2011-05-01

Control and measurement of residual stress in glass is of great importance in the industrial field. Since glass is a birefringent material, the residual stress analysis is based mainly on the photoelastic method. This paper considers two methods of automated analysis of membrane residual stress in glass sheets, based on the phase-shifting concept in monochromatic light. In particular these methods are the automated versions of goniometric compensation methods of Tardy and Sénarmont. The proposed methods can effectively replace manual methods of compensation (goniometric compensation of Tardy and Sénarmont, Babinet and Babinet-Soleil compensators) provided by current standards on the analysis of residual stresses in glasses.

Ultrathin Optical Panel And A Method Of Making An Ultrathin Optical Panel.

DOEpatents

Biscardi, Cyrus; Brewster, Calvin; DeSanto, Leonard; Veligdan, James T.

2005-02-15

An ultrathin optical panel, and a method of producing an ultrathin optical panel, are disclosed, including stacking a plurality of glass sheets, which sheets may be coated with a transparent cladding substance or may be uncoated, fastening together the plurality of stacked coated glass sheets using an epoxy or ultraviolet adhesive, applying uniform pressure to the stack, curing the stack, sawing the stack to form an inlet face on a side of the stack and an outlet face on an opposed side of the stack, bonding a coupler to the inlet face of the stack, and fastening the stack, having the coupler bonded thereto, within a rectangular housing having an open front which is aligned with the outlet face, the rectangular housing having therein a light generator which is optically aligned with the coupler. The light generator is preferably placed parallel to and proximate with the inlet face, thereby allowing for a reduction in the depth of the housing.

Ultrathin Optical Panel And A Method Of Making An Ultrathin Optical Panel.

DOEpatents

Biscardi, Cyrus; Brewster, Calvin; DeSanto, Leonard; Veligdan, James T.

2005-05-17

An ultrathin optical panel, and a method of producing an ultrathin optical panel, are disclosed, including stacking a plurality of glass sheets, which sheets may be coated with a transparent cladding substance or may be uncoated, fastening together the plurality of stacked coated glass sheets using an epoxy or ultraviolet adhesive, applying uniform pressure to the stack, curing the stack, sawing the stack to form an inlet face on a side of the stack and an outlet face on an opposed side of the stack, bonding a coupler to the inlet face of the stack, and fastening the stack, having the coupler bonded thereto, within a rectangular housing having an open front which is aligned with the outlet face, the rectangular housing having therein a light generator which is optically aligned with the coupler. The light generator is preferably placed parallel to and proximate with the inlet face, thereby allowing for a reduction in the depth of the housing.

Ultrathin optical panel and a method of making an ultrathin optical panel

DOEpatents

Biscardi, Cyrus; Brewster, Calvin; DeSanto, Leonard; Veligdan, James T.

2003-02-11

An ultrathin optical panel, and a method of producing an ultrathin optical panel, are disclosed, including stacking a plurality of glass sheets, which sheets may be coated with a transparent cladding substance or may be uncoated, fastening together the plurality of stacked coated glass sheets using an epoxy or ultraviolet adhesive, applying uniform pressure to the stack, curing the stack, sawing the stack to form an inlet face on a side of the stack and an outlet face on an opposed side of the stack, bonding a coupler to the inlet face of the stack, and fastening the stack, having the coupler bonded thereto, within a rectangular housing having an open front which is aligned with the outlet face, the rectangular housing having therein a light generator which is optically aligned with the coupler. The light generator is preferably placed parallel to and proximate with the inlet face, thereby allowing for a reduction in the depth of the housing.

Ultrathin optical panel and a method of making an ultrathin optical panel

DOEpatents

Biscardi, Cyrus; Brewster, Calvin; DeSanto, Leonard; Veligdan, James T.

2001-10-09

An ultrathin optical panel, and a method of producing an ultrathin optical panel, are disclosed, including stacking a plurality of glass sheets, which sheets may be coated with a transparent cladding substance or may be uncoated, fastening together the plurality of stacked coated glass sheets using an epoxy or ultraviolet adhesive, applying uniform pressure to the stack, curing the stack, sawing the stack to form an inlet face on a side of the stack and an outlet face on an opposed side of the stack, bonding a coupler to the inlet face of the stack, and fastening the stack, having the coupler bonded thereto, within a rectangular housing having an open front which is aligned with the outlet face, the rectangular housing having therein a light generator which is optically aligned with the coupler. The light generator is preferably placed parallel to and proximate with the inlet face, thereby allowing for a reduction in the depth of the housing.

Ultrathin optical panel and a method of making an ultrathin optical panel

DOEpatents

Biscardi, Cyrus; Brewster, Calvin; DeSanto, Leonard; Veligdan, James T.

2002-01-01

An ultrathin optical panel, and a method of producing an ultrathin optical panel, are disclosed, including stacking a plurality of glass sheets, which sheets may be coated With a transparent cladding substance or may be uncoated, fastening together the plurality of stacked coated glass sheets using an epoxy or ultraviolet adhesive, applying uniform pressure to the stack, curing the stack, sawing the stack to form an inlet face on a side of the stack and an outlet face on an opposed side of the stack, bonding a coupler to the inlet face of the stack, and fastening the stack, having the coupler bonded thereto, within a rectangular housing having an open front which is aligned with the outlet face, the rectangular housing having therein a light generator which is optically aligned with the coupler. The light generator is preferably placed parallel to and proximate with the inlet face, thereby allowing for a reduction in the depth of the housing.

Numerical Optimization of a Bifacial Bi-Glass Thin-Film a-Si:H Solar Cell for Higher Conversion Efficiency

NASA Astrophysics Data System (ADS)

Berrian, Djaber; Fathi, Mohamed; Kechouane, Mohamed

2018-02-01

Bifacial solar cells that maximize the energy output per a square meter have become a new fashion in the field of photovoltaic cells. However, the application of thin-film material on bifacial solar cells, viz., thin-film amorphous hydrogenated silicon ( a- Si:H), is extremely rare. Therefore, this paper presents the optimization and influence of the band gap, thickness and doping on the performance of a glass/glass thin-film a- Si:H ( n- i- p) bifacial solar cell, using a computer-aided simulation tool, Automat for simulation of hetero-structures (AFORS-HET). It is worth mentioning that the thickness and the band gap of the i-layer are the key parameters in achieving higher efficiency and hence it has to be handled carefully during the fabrication process. Furthermore, an efficient thin-film a- Si:H bifacial solar cell requires thinner and heavily doped n and p emitter layers. On the other hand, the band gap of the p-layer showed a dramatic reduction of the efficiency at 2.3 eV. Moreover, a high bifaciality factor of more than 92% is attained, and top efficiency of 10.9% is revealed under p side illumination. These optimizations demonstrate significant enhancements of the recent experimental work on thin-film a- Si:H bifacial solar cells and would also be useful for future experimental investigations on an efficient a- Si:H thin-film bifacial solar cell.

Thin film ion conducting coating

DOEpatents

Goldner, Ronald B.; Haas, Terry; Wong, Kwok-Keung; Seward, George

1989-01-01

Durable thin film ion conducting coatings are formed on a transparent glass substrate by the controlled deposition of the mixed oxides of lithium:tantalum or lithium:niobium. The coatings provide durable ion transport sources for thin film solid state storage batteries and electrochromic energy conservation devices.

STRUCTURE AND HIGH-FIELD PERFORMANCE OF JELLY ROLL PROCESSED Nb{sub 3}Sn WIRES USING Sn-Ta AND Sn-Ti BASED ALLOY SHEET

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tachikawa, K.; Tsuyuki, T.; Hayashi, Y.

Sn-Ta based alloy buttons of different compositions were prepared by the melt diffusion process among constituent metal powders, and then pressed into plates. Meanwhile Sn-Ti based alloy plates were sliced from the melt and cast ingot. Resulting Sn-based alloy plates were rolled into thin sheets. The Sn-based alloy sheet was laminated with a Nb sheet, and wound into a Jelly Roll (JR) composite. The composite was encased in a sheath, and fabricated into a thin wire followed by the heat treatment. The application of hydrostatic extrusion is useful at the initial stage of the fabrication. The JR wires using Sn-Tamore » and Sn-Ti based alloy sheets show a non-Cu J{sub c} of {approx}250 A/mm{sup 2} and {approx}150 A/mm{sup 2} at 20 T and 22 T, respectively, at 4.2 K. It has been found that the Nb impregnates into the Sn-based alloy layers during the reaction, and Nb{sub 3}Sn layers are synthesized by the mutual diffusion between the Nb sheet and the Sn-based alloy sheet without formation of voids. Sn-Ti based alloy sheets are attractive due to their easiness of mass production. Structure and high-field performance of JR processed Nb{sub 3}Sn wires prepared from Sn-based alloy sheets with different compositions are compared in this article.« less

Method for forming glass-to-metal seals

DOEpatents

Kramer, D.P.; Massey, R.T.

1985-08-26

Disclosed is a method for forming a glass-to-metal seal in which the glass has a higher melting point than the metal. The molten glass is vacuum injection molded onto the metal, thus melting a very thin layer of the surface of the metal long enough to form a seal, but not long enough to cause a distortion in the shape of the metal component.

Effects of PV Module Soiling on Glass Surface Resistance and Potential-Induced Degradation: Preprint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hacke, Peter; Burton, Patrick; Hendrickson, Alex

2015-12-03

The sheet resistance of three soil types (Arizona road dust, soot, and sea salt) on glass were measured by the transmission line method as a function of relative humidity (RH) between 39% and 95% at 60 degrees C. Sea salt yielded a 3.5 order of magnitude decrease in resistance on the glass surface when the RH was increased over this RH range. Arizona road dust showed reduced sheet resistance at lower RH, but with less humidity sensitivity over the range tested. The soot sample did not show significant resistivity change compared to the unsoiled control. Photovoltaic modules with sea saltmore » on their faces were step-stressed between 25% and 95% RH at 60 degrees C applying -1000 V bias to the active cell circuit. Leakage current from the cell circuit to ground ranged between two and ten times higher than that of the unsoiled controls. Degradation rate of modules with salt on the surface increased with increasing RH and time.« less

From Outlet Glacier Changes to Ice Sheet Mass Balance - Evolution of Greenland Ice Sheet from Laser Altimetry Data

NASA Astrophysics Data System (ADS)

Csatho, B. M.; Schenk, A.; Nagarajan, S.; Babonis, G. S.

2010-12-01

Investigations of ice sheet mass balance and the changing dynamics of outlet glaciers have been hampered by the lack of comprehensive data. In recent years, this situation has been remedied. Satellite laser altimetry data from the Ice Cloud and land Elevation Satellite mission (ICESat), combined with airborne laser altimetry, provide accurate measurements of surface elevation changes, and surface velocities derived from various satellite platforms yield crucial information on changing glacier dynamics. Taken together, a rich and diverse data set is emerging that allows for characterizing the spatial and temporal evolution of ice sheets and outlet glaciers. In particular, it enables quantitative studies of outlet glaciers undergoing rapid and complex changes. Although airborne and laser altimetry have been providing precise measurements of ice sheet topography since the early 1990s, determining detailed and accurate spatial and temporal distribution of surface changes remains a challenging problem. We have developed a new, comprehensive method, called Surface Elevation Reconstruction And Change detection (SERAC), which estimates surface changes by a simultaneous reconstruction of surface topography from fused multisensor data. The mathematical model is based on the assumption that for a small surface area, only the absolute elevation changes over time but not the shape of the surface patch. Therefore, laser points of all time epochs contribute to the shape parameters; points of each time period determine the absolute elevation of the surface patch at that period. This method provides high-resolution surface topography, precise changes and a rigorous error estimate of the quantities. By using SERAC we combined ICESat and ATM laser altimetry data to determine the evolution of surface change rates of the whole Greenland Ice Sheet between 2003 and 2009 on a high-resolution grid. Our reconstruction, consistent with GRACE results, shows ice sheet thinning propagating along the NW coast, and thinning expanding to higher elevations in SW and N Greenland. Several outlet glaciers, for example Humboldt and Petermann glaciers in NW Greenland and Kangilerngata Sermia in W Greenland exhibit a complex spatial and temporal pattern of thickening-thinning with regions of thickening observed at lower elevations. We will examine the thickening and thinning history and the record of surface velocity of these glaciers to investigate the processes responsible for initiating and sustaining these changes. Moreover, by analyzing the detailed surface elevation change history along flowlines or across drainage basins, the propagation of thinning following perturbations at the glacier terminus can be investigated. Results, depicting the evolution of surface elevation changes of three major outlet glaciers, Jakobshavn, Helheim and Kangerlussuaq glaciers, will be shown.

Experimental study of fiber-glass plastic work pieces contour milling

NASA Astrophysics Data System (ADS)

Trushin, N. N.; Lisitsin, V. N.

2018-03-01

The article represents the results of study of cut and feed speed influence on wear of monolithic hard alloy end milling cutter during cutting of foiled fiber-glass plastic sheets, used for printed-circuit boards’ production. The peculiarities and problems of cutting layered materials are described. The most effective feed and cut speed values are determined by cutter wear analysis.

Study of Sb2S3 thin films deposited by SILAR method

NASA Astrophysics Data System (ADS)

Deshpande, M. P.; Chauhan, Krishna; Patel, Kiran N.; Rajput, Piyush; Bhoi, Hiteshkumar R.; Chaki, S. H.

2018-05-01

In the present work, we deposited Sb2S3 thin films on glass slide by successive ionic layer adsorption and reaction (SILAR) technique with different time cycles. From EDAX, we could observe that the films were non-stoichiometric and contained few elements from glass slide. X-ray diffraction has shown that these films are orthorhombic in structure from where we have calculated the lattice parameter and crystallize size. SEM images shows that SILAR synthesized Sb2S3 thin films are homogenous and well distributed indicating the formation of uniform thin films at lower concentration. The room temperature Raman spectra of Sb2S3 thin films showed sharp peaks at 250 cm‑1 and 300 cm‑1 for all cases. Room temperature photoluminescence emission spectrum shows broad bands over 430–480 nm range with strong blue emission peak centered at same wavelength of 460 nm (2.70 eV) for all cases.

Thermal History and Crystallinity of Sheet Intrusions

NASA Astrophysics Data System (ADS)

Whittington, A. G.; Nabelek, P. I.; Hofmeister, A.

2011-12-01

Magma emplaced in a sheet intrusion has two potential fates: to crystallize, or quench to glass. Rapidly chilled sheet margins are typically glassy or microcrystalline, while interiors are coarser-grained. The actual textures result from a combination of thermal history and crystallization kinetics, which are related by various feedback mechanisms. The thermal history of cooling sheet intrusions is often approximated using the analytical solution for a semi-infinite half-space, which uses constant thermal properties such as heat capacity (CP), thermal diffusivity (D) and thermal conductivity (k = DρCP), where ρ is density. In reality, both CP and D are strongly T-dependent for glasses and crystals, and melts have higher CP and lower D than crystals or glasses. Another first-order feature ignored in the analytical solution is latent heat of crystallization (ΔHxt), which can be implemented numerically as extra heat capacity over the crystallization interval. For rhyolite melts, D is ~0.5 mm2s-1 and k is ~1.5 Wm-1K-1, which are similar to those of major crustal rock types and granitic protoliths at magmatic temperatures, suggesting that changes in thermal properties accompanying partial melting of the crust should be relatively minor. Numerical models of hot (~920°C liquidus for 0.5 wt.% H2O) shallow rhyolite intrusions indicate that the key difference in thermal history between bodies that quench to obsidian, and those that crystallize, results from the release of latent heat of crystallization, which enables bodies that crystallize to remain at high temperatures for much longer times. The time to solidification is similar in both cases, however, because solidification requires cooling through the glass transition (Tg ~620°C) in the first case, and cooling only to the solidus (~770°C) in the second. For basaltic melts, D is ~0.3 mm2s-1 and k is ~1.0 Wm-1K-1, compared to ~0.6 mm2s-1 and 2.5 Wm-1K-1 for crystalline basalt or peridotite at magmatic temperatures, suggesting that changes in thermal properties accompanying partial melting of the mantle or crystallization of basalt may be important. Numerical models of basaltic sheet intrusions indicate that they will almost always crystallize, even at sheet margins, because their emplacement temperature (~1220°C) is sufficiently high that the country rock adjacent to the sheet will be raised above the Tg of the melt (~650°C). The long period of time spent above Tg, combined with the rapid crystallization kinetics of basaltic melts, ensures that crystallization is near-complete, even if the crystal size is small, except where unusually rapid chilling occurs due to efficient convective or radiative losses (for example subaerial, subaqeous or subglacial lava flows).

Radiation-induced deposition of transparent conductive tin oxide coatings

NASA Astrophysics Data System (ADS)

Umnov, S.; Asainov, O.; Temenkov, V.

2016-04-01

The study of tin oxide films is stimulated by the search for an alternative replacement of indium-tin oxide (ITO) films used as transparent conductors, oxidation catalysts, material gas sensors, etc. This work was aimed at studying the influence of argon ions irradiation on optical and electrical characteristics of tin oxide films. Thin films of tin oxide (without dopants) were deposited on glass substrates at room temperature using reactive magnetron sputtering. After deposition, the films were irradiated with an argon ion beam. The current density of the beam was (were) 2.5 mA/cm2, and the particles energy was 300-400 eV. The change of the optical and electrical properties of the films depending on the irradiation time was studied. Films optical properties were investigated by photometry in the range of 300-1100 nm. Films structural properties were studied using X-ray diffraction. The diffractometric research showed that the films, deposited on a substrate, had a crystal structure, and after argon ions irradiation they became quasi-crystalline (amorphous). It has been found that the transmission increases proportionally with the irradiation time, however the sheet resistance increases disproportionally. Tin oxide films (thickness ~30 nm) with ~100% transmittance and sheet resistance of ~100 kOhm/sq. were obtained. The study has proved to be prospective in the use of ion beams to improve the properties of transparent conducting oxides.

Fabrication of highly conductive graphene/ITO transparent bi-film through CVD and organic additives-free sol-gel techniques.

PubMed

Hemasiri, Bastian Waduge Naveen Harindu; Kim, Jae-Kwan; Lee, Ji-Myon

2017-12-19

Indium tin oxide (ITO) still remains as the main candidate for high-performance optoelectronic devices, but there is a vital requirement in the development of sol-gel based synthesizing techniques with regards to green environment and higher conductivity. Graphene/ITO transparent bi-film was synthesized by a two-step process: 10 wt. % tin-doped ITO thin films were produced by an environmentally friendly aqueous sol-gel spin coating technique with economical salts of In(NO 3 ) 3 .H 2 O and SnCl 4 , without using organic additives, on surface free energy enhanced (from 53.826 to 97.698 mJm -2 ) glass substrate by oxygen plasma treatment, which facilitated void-free continuous ITO film due to high surface wetting. The chemical vapor deposited monolayer graphene was transferred onto the synthesized ITO to enhance its electrical properties and it was capable of reducing sheet resistance over 12% while preserving the bi-film surface smoother. The ITO films contain the In 2 O 3 phase only and exhibit the polycrystalline nature of cubic structure with 14.35 ± 0.5 nm crystallite size. The graphene/ITO bi-film exhibits reproducible optical transparency with 88.66% transmittance at 550 nm wavelength, and electrical conductivity with sheet resistance of 117 Ω/sq which is much lower than that of individual sol-gel derived ITO film.

Use of thin film transistor liquid crystal display (TFT-LCD) waste glass in the production of ceramic tiles.

PubMed

Lin, Kae-Long

2007-09-05

In this study, we employ the following operating conditions: varied pressure (25 kgf/cm(2)), sintering temperature (900-1200 degrees C), sintering time (6h), percentage of thin film transistor liquid crystal display (TFT-LCD) waste glass by weight (0-50%) and temperature rising at a rate of 5 degrees C/min, to fabricate clay tiles. The sintering characteristics of the clay blended with TFT-LCD waste glass tiles are examined to evaluate the feasibility of the reuse of TFT-LCD waste glass. TFT-LCD waste glass contains large amounts of glass. The TCLP leaching concentrations all met the ROC EPAs current regulatory thresholds. The addition of TFT-LCD waste glass to the mixture, increased the apparent weight loss. The incorporation of 50% TFT-LCD waste glass resulted in a significant increase in the porosity ratio of the specimens compared to the porosity ratio of the ceramic tile containing TFT-LCD waste glass. The main constituent in both the clay tile and the clay with TFT-LCD waste glass samples is quartz. Increasing the temperature resulted in an increase in the flexural strength and resistance to abrasion in the tiles. The porosity ratio decreases as shrinkage increases. The relation between the porosity ratio and the hardness of the tiles used in the study is also shown.

Low-cost ultra-thin broadband terahertz beam-splitter.

PubMed

Ung, Benjamin S-Y; Fumeaux, Christophe; Lin, Hungyen; Fischer, Bernd M; Ng, Brian W-H; Abbott, Derek

2012-02-27

A low-cost terahertz beam-splitter is fabricated using ultra-thin LDPE plastic sheeting coated with a conducting silver layer. The beam splitting ratio is determined as a function of the thickness of the silver layer--thus any required splitting ratio can be printed on demand with a suitable rapid prototyping technology. The low-cost aspect is a consequence of the fact that ultra-thin LDPE sheeting is readily obtainable, known more commonly as domestic plastic wrap or cling wrap. The proposed beam-splitter has numerous advantages over float zone silicon wafers commonly used within the terahertz frequency range. These advantages include low-cost, ease of handling, ultra-thin thickness, and any required beam splitting ratio can be readily fabricated. Furthermore, as the beam-splitter is ultra-thin, it presents low loss and does not suffer from Fabry-Pérot effects. Measurements performed on manufactured prototypes with different splitting ratios demonstrate a good agreement with our theoretical model in both P and S polarizations, exhibiting nearly frequency-independent splitting ratios in the terahertz frequency range.

Angle-independent VO2 Thin Film on Glass Fiber Cloth as a Soft-Smart-Mirror (SSM)

PubMed Central

Cai, Nianjin; Zhang, Wang; Wang, Wanlin; Zhu, Yuchen; Zada, Imran; Gu, Jiajun; Liu, Qinglei; Su, Huilan; Guo, Cuiping; Zhang, Zhijian; Zhang, Jianzhong; Wu, Liping; Zhang, Di

2016-01-01

Designing materials with a negative feedback function is beneficial for achieving temperature regulation inside a greenhouse. VO2 has been studied extensively because of its low insulator-to-metal transition temperature (IMT). In this study, reflection changes during a VO2 phase transition were investigated. Glass fiber cloth was used as a substrate, as it is stable and soft. A VO2 thin film on a glass fiber cloth whose surface contained 96% V4+ and 4% V5+ was prepared using an inorganic sol-gels method. The insulator-to-metal transition temperature was decreased by 38 °C, which was observed from the reflection curve detected using an angle-resolved spectrometer. This decrease in IMT occurred mainly because of the presence of V5+, which causes destabilization of the monoclinic phase of VO2. When the greenhouse temperature was increased from 30 °C to 40 °C, the reflected intensity of VO2 on glass fiber cloth decreased by 22% for the wavelength range of 400 nm to 800 nm. In addition, the angle-independent property of the VO2 thin film was observed using an angle-resolved spectrometer. Owing to its thermo-reflective properties, the thin film can serve as a soft-smart-mirror (SSM) inside a greenhouse to stabilize the temperature, playing a negative feedback role. PMID:27849051

Angle-independent VO2 Thin Film on Glass Fiber Cloth as a Soft-Smart-Mirror (SSM)

NASA Astrophysics Data System (ADS)

Cai, Nianjin; Zhang, Wang; Wang, Wanlin; Zhu, Yuchen; Zada, Imran; Gu, Jiajun; Liu, Qinglei; Su, Huilan; Guo, Cuiping; Zhang, Zhijian; Zhang, Jianzhong; Wu, Liping; Zhang, Di

2016-11-01

Designing materials with a negative feedback function is beneficial for achieving temperature regulation inside a greenhouse. VO2 has been studied extensively because of its low insulator-to-metal transition temperature (IMT). In this study, reflection changes during a VO2 phase transition were investigated. Glass fiber cloth was used as a substrate, as it is stable and soft. A VO2 thin film on a glass fiber cloth whose surface contained 96% V4+ and 4% V5+ was prepared using an inorganic sol-gels method. The insulator-to-metal transition temperature was decreased by 38 °C, which was observed from the reflection curve detected using an angle-resolved spectrometer. This decrease in IMT occurred mainly because of the presence of V5+, which causes destabilization of the monoclinic phase of VO2. When the greenhouse temperature was increased from 30 °C to 40 °C, the reflected intensity of VO2 on glass fiber cloth decreased by 22% for the wavelength range of 400 nm to 800 nm. In addition, the angle-independent property of the VO2 thin film was observed using an angle-resolved spectrometer. Owing to its thermo-reflective properties, the thin film can serve as a soft-smart-mirror (SSM) inside a greenhouse to stabilize the temperature, playing a negative feedback role.

Angle-independent VO2 Thin Film on Glass Fiber Cloth as a Soft-Smart-Mirror (SSM).

PubMed

Cai, Nianjin; Zhang, Wang; Wang, Wanlin; Zhu, Yuchen; Zada, Imran; Gu, Jiajun; Liu, Qinglei; Su, Huilan; Guo, Cuiping; Zhang, Zhijian; Zhang, Jianzhong; Wu, Liping; Zhang, Di

2016-11-16

Designing materials with a negative feedback function is beneficial for achieving temperature regulation inside a greenhouse. VO 2 has been studied extensively because of its low insulator-to-metal transition temperature (IMT). In this study, reflection changes during a VO 2 phase transition were investigated. Glass fiber cloth was used as a substrate, as it is stable and soft. A VO 2 thin film on a glass fiber cloth whose surface contained 96% V 4+ and 4% V 5+ was prepared using an inorganic sol-gels method. The insulator-to-metal transition temperature was decreased by 38 °C, which was observed from the reflection curve detected using an angle-resolved spectrometer. This decrease in IMT occurred mainly because of the presence of V 5+ , which causes destabilization of the monoclinic phase of VO 2 . When the greenhouse temperature was increased from 30 °C to 40 °C, the reflected intensity of VO 2 on glass fiber cloth decreased by 22% for the wavelength range of 400 nm to 800 nm. In addition, the angle-independent property of the VO 2 thin film was observed using an angle-resolved spectrometer. Owing to its thermo-reflective properties, the thin film can serve as a soft-smart-mirror (SSM) inside a greenhouse to stabilize the temperature, playing a negative feedback role.

Method for shaping sheet thermoplastic and the like

NASA Technical Reports Server (NTRS)

Akilian, Mireille K. (Inventor); Schattenburg, Mark L. (Inventor)

2011-01-01

Processes and apparati for shaping sheet glass or thermoplastic materials use force from a layer of a flowing fluid, such as air, between the sheet and a mandrel at close to the softening temperature of the thermoplastic. The shape is preserved by cooling. The shape of the air bearing mandrel and the pressure distribution of the fluid contribute to the final shape. A process can be conducted on one or two surfaces such that the force from the air layer is on one or two surfaces of the sheet. The gap size between the sheet and mandrel determines the pressure profile in the gap, which also determines the final sheet shape. In general, smaller gaps lead to larger viscous forces. The pressure profile depends on the shape of the mandrel, the size of the fluid gap and the sheet and the fluid supply pressure.

Mechanical properties of reinforced denture base resin: the effect of position and the number of woven glass fibers.

PubMed

Kanie, Takahito; Arikawa, Hiroyuki; Fujii, Koichi; Ban, Seiji

2002-09-01

This study examined the effects of the position and the number of woven glass fibers on the flexural strength, flexural modulus, and toughness of reinforced denture base resin. The woven glass fiber consisted of 1-4 laminated sheets. Chemical curing was used to polymerize three types of 4-mm-thick test specimens: fibers in compresrion, fibers in the center, and fibers in tension. Unreinforced specimens were produced as controls. A three-point flexural test was performed and the woven glass fiber content was calculated after the woven glass fiber was fired. The best results were obtained when the woven glass fiber was incorporated outside the base resin under tension, thereby increasing the flexural strength and flexural modulus. Furthermore, the denture base resin reinforced with woven glass fiber was made tougher by increasing the number of woven glass fibers incorporated into the portion under tension.

Coupled ice sheet-ocean modelling to investigate ocean driven melting of marine ice sheets in Antarctica

NASA Astrophysics Data System (ADS)

Jong, Lenneke; Gladstone, Rupert; Galton-Fenzi, Ben

2017-04-01

Ocean induced melting below the ice shelves of marine ice sheets is a major source of uncertainty for predictions of ice mass loss and Antarctica's resultant contribution to future sea level rise. The floating ice shelves provide a buttressing force against the flow of ice across the grounding line into the ocean. Thinning of these ice shelves due to an increase in melting reduces this force and can lead to an increase in the discharge of grounded ice. Fully coupled modelling of ice sheet-ocean interactions is key to improving understanding the influence of the Southern ocean on the evolution of the Antarctic ice sheet, and to predicting its future behaviour under changing climate conditions. Coupling of ocean and ice sheet models is needed to provide more realistic melt rates at the base of ice shelves and hence make better predictions of the behaviour of the grounding line and the shape of the ice-shelf cavity as the ice sheet evolves. The Framework for Ice Sheet - Ocean Coupling (FISOC) has been developed to provide a flexible platform for performing coupled ice sheet - ocean modelling experiments. We present preliminary results using FISOC to couple the Regional Ocean Modelling System (ROMS) with Elmer/Ice in idealised experiments Marine Ice Sheet-Ocean Model Intercomparison Project (MISOMIP). These experiments use an idealised geometry motivated by that of Pine Island glacier and the adjacent Amundsen Sea in West Antarctica, a region which has shown shown signs of thinning ice and grounding line retreat.

Meshless modelling of dynamic behaviour of glasses under intense shock loadings: Application to matter ejection during high velocity impacts on thin brittle targets

NASA Astrophysics Data System (ADS)

Michel, Y.; Chevalier, J.-M.; Durin, C.; Espinosa, C.; Malaise, F.; Barrau, J.-J.

2006-08-01

The purpose of this study is to present a new material model adapted to SPH modelling of dynamic behaviour of glasses under shock loadings. This model has the ability to reproduce fragmentation and densification of glasses under compression as well as brittle tensile failure. It has been implemented in Ls-Dyna software and coupled with a SPH code. By comparison with CEA-CESTA experimental data the model has been validated for fused silica and Pyrex glass for stress level up to 35GPa. For Laser MegaJoule applications, the present material model was applied to 3D high velocity impacts on thin brittle targets with good agreement with experimental data obtained using CESTA's double stage light gas gun in term of damages and matter ejection.

Rapid Deposition Technology Holds the Key for the World's Largest Manufacturer of Thin-Film Solar Modules (Fact Sheet)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

2013-08-01

First Solar, Inc. has been collaborating with NREL since 1991, advancing its thin-film cadmium telluride solar technology to grow from a startup company to become one of the world's largest manufacturers of solar modules, and the world's largest manufacturer of thin-film solar modules.

Parametrization of optical properties of indium-tin-oxide thin films by spectroscopic ellipsometry: Substrate interfacial reactivity

NASA Astrophysics Data System (ADS)

Losurdo, M.; Giangregorio, M.; Capezzuto, P.; Bruno, G.; de Rosa, R.; Roca, F.; Summonte, C.; Plá, J.; Rizzoli, R.

2002-01-01

Indium-tin-oxide (ITO) films deposited by sputtering and e-gun evaporation on both transparent (Corning glass) and opaque (c-Si, c-Si/SiO2) substrates and in c-Si/a-Si:H/ITO heterostructures have been analyzed by spectroscopic ellipsometry (SE) in the range 1.5-5.0 eV. Taking the SE advantage of being applicable to absorbent substrate, ellipsometry is used to determine the spectra of the refractive index and extinction coefficient of the ITO films. The effect of the substrate surface on the ITO optical properties is focused and discussed. To this aim, a parametrized equation combining the Drude model, which considers the free-carrier response at the infrared end, and a double Lorentzian oscillator, which takes into account the interband transition contribution at the UV end, is used to model the ITO optical properties in the useful UV-visible range, whatever the substrate and deposition technique. Ellipsometric analysis is corroborated by sheet resistance measurements.

Preparation of Cobalt-Based Electrodes by Physical Vapor Deposition on Various Nonconductive Substrates for Electrocatalytic Water Oxidation.

PubMed

Wu, Yizhen; Wang, Le; Chen, Mingxing; Jin, Zhaoxia; Zhang, Wei; Cao, Rui

2017-12-08

Artificial photosynthesis requires efficient anodic electrode materials for water oxidation. Cobalt metal thin films are prepared through facile physical vapor deposition (PVD) on various nonconductive substrates, including regular and quartz glass, mica sheet, polyimide, and polyethylene terephthalate (PET). Subsequent surface electrochemical modification by cyclic voltammetry (CV) renders these films active for electrocatalytic water oxidation, reaching a current density of 10 mA cm -2 at a low overpotential of 330 mV in 1.0 m KOH solution. These electrodes are robust with unchanged activity throughout prolonged chronopotentiometry measurements. This work is thus significant to show that the combination of PVD and CV is very valuable and convenient to fabricate active electrodes on various nonconductive substrates, particularly with flexible polyimide and PET substrates. This efficient, safe and convenient method can potentially be expanded to many other electrochemical applications. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effect of annealing over optoelectronic properties of graphene based transparent electrodes

NASA Astrophysics Data System (ADS)

Yadav, Shriniwas; Kaur, Inderpreet

2016-04-01

Graphene, an atom-thick two dimensional graphitic material have led various fundamental breakthroughs in the field of science and technology. Due to their exceptional optical, physical and electrical properties, graphene based transparent electrodes have shown several applications in organic light emitting diodes, solar cells and thin film transistors. Here, we are presenting effect of annealing over optoelectronic properties of graphene based transparent electrodes. Graphene based transparent electrodes have been prepared by wet chemical approach over glass substrates. After fabrication, these electrodes tested for optical transmittance in visible region. Sheet resistance was measured using four probe method. Effect of thermal annealing at 200 °C was studied over optical and electrical performance of these electrodes. Optoelectronic performance was judged from ratio of direct current conductivity to optical conductivity (σdc/σopt) as a figure of merit for transparent conductors. The fabricated electrodes display good optical and electrical properties. Such electrodes can be alternatives for doped metal oxide based transparent electrodes.

Materials for Stretchable Electronics - Electronic Eyeballs, Brain Monitors and Other Applications

ScienceCinema

Rogers, John A. [University of Illinois, Urbana Champaign, Illinois, United States

2017-12-09

Electronic circuits that involve transistors and related components on thin plastic sheets or rubber slabs offer mechanical properties (e.g. bendability, stretchability) and other features (e.g. lightweight, rugged construction) which cannot be easily achieved with technologies that use rigid, fragile semiconductor wafer or glass substrates.  Device examples include personal or structural health monitors and electronic eye imagers, in which the electronics must conform to complex curvilinear shapes or flex/stretch during use.  Our recent work accomplishes these technology outcomes by use of single crystal inorganic nanomaterials in ‘wavy’ buckled configurations on elastomeric supports.  This talk will describe key fundamental materials and mechanics aspects of these approaches, as well as engineering features of their use in individual transistors, photodiodes and integrated circuits.  Cardiac and brain monitoring devices provide examples of application in biomedicine; hemispherical electronic eye cameras illustrate new capacities for bio-inspired device design.

Synthesis and characterization of structural, morphological and photosensor properties of Cu0.1Zn0.9S thin film prepared by a facile chemical method

NASA Astrophysics Data System (ADS)

Gubari, Ghamdan M. M.; Ibrahim Mohammed S., M.; Huse, Nanasaheb P.; Dive, Avinash S.; Sharma, Ramphal

2018-05-01

The Cu0.1Zn0.9S thin film was grown by facile chemical bath deposition (CBD) method on glass substrates at 60°C. The structural, morphological, photosensor properties of the as-grown thin film has been investigated. The structural and phase confirmation of the as-grown thin film was carried out by X-ray diffraction (XRD) technique and Raman spectroscopy. The FE-SEM images showed that the thin films are well covered with material on an entire glass substrate. From the optical absorption spectrum, the direct band gap energy for the Cu0.1Zn0.9S thin film was found to be ˜3.16 eV at room temperature. The electrical properties were measured at room temperature in the voltage range ±2.5 V, showed a drastic enhancement in current under light illumination with the highest photosensitivity of ˜72 % for 260 W.

High quality nitrogen-doped zinc oxide thin films grown on ITO by sol-gel method

NASA Astrophysics Data System (ADS)

Pathak, Trilok Kumar; Kumar, Vinod; Purohit, L. P.

2015-11-01

Highly transparent N-doped ZnO thin films were deposited on ITO coated corning glass substrate by sol-gel method. Ammonium nitrate was used as a dopant source of N with varying the doping concentration 0, 0.5, 1.0, 2.0 and 3.0 at%. The DSC analysis of prepared NZO sols is observed a phase transition at 150 °C. X-ray diffraction pattern showed the preferred (002) peak of ZnO, which was deteriorated with increased N concentrations. The transmittance of NZO thin films was observed to be ~88%. The bandgap of NZO thin films increased from 3.28 to 3.70 eV with increased N concentration from 0 to 3 at%. The maximum carrier concentration 8.36×1017 cm-3 and minimum resistivity 1.64 Ω cm was observed for 3 at% N doped ZnO thin films deposited on glass substrate. These highly transparent ZnO thin films can be used as a window layer in solar cells and optoelectronic devices.

Crystallization, fluoridation and some properties of apatite thin films prepared through rf-sputtering from CaO-P2O5 glasses.

PubMed

Yamashita, K; Matsuda, M; Arashi, T; Umegaki, T

1998-07-01

Using calcium phosphate glass targets with the CaO/P2O5 molar ratios of 1.50-0.50, much lower than the stoichiometric value of 3.3 for hydroxyapatite, thin films of stoichiometric hydroxy-, nonstoichiometric oxyhydroxy- and Ca-deficient oxyhydroxy-apatites were prepared on alumina ceramic substrates by rf-sputtering followed by post-annealing. Based on the present results, a phase diagram for CaO-P2O5 at low temperatures in the ambience of air was depicted for thin films. The ambient H2O vapor had an influence on the phase diagram: Tricalcium phosphate was changed to apatite in the presence of H2O vapor. Dense fluorohydroxyapatite thin films were prepared by fluoridation of those apatite thin films at a low temperature such as 200 degrees C. In the present report, some functional properties of thin films thus prepared were also shown.

Radial-rotation profile forming: A new processing technology of incremental sheet metal forming

NASA Astrophysics Data System (ADS)

Laue, Robert; Härtel, Sebastian; Awiszus, Birgit

2018-05-01

Incremental forming processes (i.e., spinning) of sheet metal blanks into cylindrical cups are suitable for lower lot sizes. The produced cups were frequently used as preforms to produce workpieces in further forming steps with additional functions like profiled hollow parts [1]. The incremental forming process radial-rotation profile forming has been developed to enable the production of profiled hollow parts with low sheet thinning and good geometrical accuracy. The two principal forming steps are the production of the preform by rotational swing-folding [2] and the subsequent radial profiling of the hollow part in one clamping position. The rotational swing-folding process is based on a combination of conventional spinning and swing-folding. Therefore, a round blank rotates on a profiled mandrel and due to the swinging of a cylindrical forming tool, the blank is formed to a cup with low sheet thinning. In addition, thickening results at the edge of the blank and wrinkling occurs. However, the wrinkles are formed into the indentation of the profiled mandrel and can be reshaped as an advantage in the second process step, the radial profiling. Due to the rotation and continuous radial feed of a profiled forming tool to the profiled mandrel, the axial profile is formed in the second process step. Because of the minor relative movement in axial direction between tool and blank, low sheet thinning occurs. This is an advantage of the principle of the process.

Experimental Investigation of the Capacity of Steel Fibers to Ensure the Structural Integrity of Reinforced Concrete Specimens Coated with CFRP Sheets

NASA Astrophysics Data System (ADS)

Gribniak, V.; Arnautov, A. K.; Norkus, A.; Tamulenas, V.; Gudonis, E.; Sokolov, A.

2016-07-01

The capacity of steel fibers to ensure the structural integrity of reinforced concrete specimens coated with CFRP sheets was investigated. Test data for four ties and eight beams reinforced with steel or glass-FRP bars are presented. Experiments showed that the fibers significantly increased the cracking resistance and altered the failure character from the splitting of concrete to the debonding of the external sheets, which noticeably increased the load-carrying capacity of the strengthened specimens.

Home page | prc.gatech.edu | Georgia Institute of Technology | Atlanta, GA

Science.gov Websites

Interconnections & Assembly Low Cost Glass Interposers & Packages MEMS and Sensors GRA Opportunities addressing electrical, mechanical and thermal barriers. Low-cost Glass Interposer and Package Panel-based ultra-thin glass as a high performance, high I/O density, and low cost platform. Interconnections and

Method to protect charge recombination in the back-contact dye-sensitized solar cell.

PubMed

Yoo, Beomjin; Kim, Kang-Jin; Lee, Doh-Kwon; Kim, Kyungkon; Ko, Min Jae; Kim, Yong Hyun; Kim, Won Mok; Park, Nam-Gyu

2010-09-13

We prepared a back-contact dye-sensitized solar cell and investigated effect of the sputter deposited thin TiO₂ film on the back-contact ITO electrode on photovoltaic property. The nanocrystalline TiO₂ layer with thickness of about 11 μm formed on a plain glass substrate in the back-contact structure showed higher optical transmittance than that formed on an ITO-coated glass substrate, which led to an improved photocurrent density by about 6.3%. However, photovoltage was found to decrease from 817 mV to 773 mV. The photovoltage recovered after deposition of a 35 nm-thick thin TiO₂ film on the surface of the back-contact ITO electrode. Little difference in time constant for electron transport was found for the back-contact ITO electrodes with and without the sputter deposited thin TiO₂ film. Whereas, time constant for charge recombination increased after introduction of the thin TiO₂ film, indicating that such a thin TiO₂ film protected back electron transfer, associated with the recovery of photovoltage. As the result of the improved photocurrent density without deterioration of photovoltage, the back-contact dye-sensitized solar cell exhibited 13.6% higher efficiency than the ITO-coated glass substrate-based dye-sensitized solar cell.

Flexible strain sensors with high performance based on metallic glass thin film

NASA Astrophysics Data System (ADS)

Xian, H. J.; Cao, C. R.; Shi, J. A.; Zhu, X. S.; Hu, Y. C.; Huang, Y. F.; Meng, S.; Gu, L.; Liu, Y. H.; Bai, H. Y.; Wang, W. H.

2017-09-01

Searching strain sensitive materials for electronic skin is of crucial significance because of the restrictions of current materials such as poor electrical conductivity, large energy consumption, complex manufacturing process, and high cost. Here, we report a flexible strain sensor based on the Zr55Cu30Ni5Al10 metallic glass thin film which we name metallic glass skin. The metallic glass skin, synthesized by ion beam deposition, exhibits piezoresistance effects with a gauge factor of around 2.86, a large detectable strain range (˜1% or 180° bending angle), and good conductivity. Compared to other e-skin materials, the temperature coefficient of resistance of the metallic glass skin is extremely low (9.04 × 10-6 K-1), which is essential for the reduction in thermal drift. In addition, the metallic glass skin exhibits distinct antibacterial behavior desired for medical applications, also excellent reproducibility and repeatability (over 1000 times), nearly perfect linearity, low manufacturing cost, and negligible energy consumption, all of which are required for electronic skin for practical applications.

Elastic behavior and onset of cracking in cement composite plates reinforced by perforated thin steel sheets

NASA Astrophysics Data System (ADS)

Aronchik, V.

1996-03-01

Thin cement mortar plates reinforced by perforated thin steel sheets have been tested in four-point flexure loading. Six kinds of sheet reinforcement and to additional ones (for control) were used. Perforated sheets of the Daugavpils Factory of Machinery Chains differed by their thickness (0.6-1.8 mm), shape (round, rectangular, oval, "dumbbell"), and mark of steel (St. 08, 50, 70). Dimensions of plantes were 100×20×2 cm. Cements-sand mortar with a 1∶2 ratio of cement PZ35 and river sand of 3 mm grains was used as a matrix. Control specimens of similar dimensions and matrix were reinforced by wire cages and meshes (ferrocement). The testing was performed using an UMM-5 testing machine. Maximum deflection (at the midspan), tension, and shear strains were recorded. The expeimental data are presented in tables and graphs. The testing results showed that the elasticity modulus of material was in good agreement with the "admixture rule;" an onset of cracking for all types (excluding one) practically did not differ from reference samples; the mode of fracture in typical cases included an adhesion failure and significant shear strains. In one case the limit of the tension strength of the reinforcement was achieved.

Electro-optical backplane demonstrator with integrated multimode gradient-index thin glass waveguide panel

NASA Astrophysics Data System (ADS)

Schröder, Henning; Brusberg, Lars; Pitwon, Richard; Whalley, Simon; Wang, Kai; Miller, Allen; Herbst, Christian; Weber, Daniel; Lang, Klaus-Dieter

2015-03-01

Optical interconnects for data transmission at board level offer increased energy efficiency, system density, and bandwidth scalability compared to purely copper driven systems. We present recent results on manufacturing of electrooptical printed circuit board (PCB) with integrated planar glass waveguides. The graded index multi-mode waveguides are patterned inside commercially available thin-glass panels by performing a specific ion-exchange process. The glass waveguide panel is embedded within the layer stack-up of a PCB using proven industrial processes. This paper describes the design, manufacture, assembly and characterization of the first electro-optical backplane demonstrator based on integrated planar glass waveguides. The electro-optical backplane in question is created by laminating the glass waveguide panel into a conventional multi-layer electronic printed circuit board stack-up. High precision ferrule mounts are automatically assembled, which will enable MT compliant connectors to be plugged accurately to the embedded waveguide interfaces on the glass panel edges. The demonstration platform comprises a standardized sub-rack chassis and five pluggable test cards each housing optical engines and pluggable optical connectors. The test cards support a variety of different data interfaces and can support data rates of up to 32 Gb/s per channel.

Outlet Glacier and Margin Elevation Changes: Near - Coastal Thinning of The Greenland Ice Sheet

NASA Technical Reports Server (NTRS)

Abdalati, W.; Krabill, W.; Frederick, E.; Manizade, S.; Martin, C.; Sonntag, J.; Swift, R.; Thomas, R.; Wright, W.; Yungel, J.;

Modulated optical phase conjugation in rhodamine 110 doped boric acid glass saturable absorber thin films

NASA Astrophysics Data System (ADS)

Sharma, Ramesh C.; Waigh, Thomas A.; Singh, Jagdish P.

2008-03-01

The optical phase conjugation signal in nearly nondegenerate four wave mixing was studied using a rhodamine 110 doped boric acid glass saturable absorber nonlinear medium. We have demonstrated a narrow band optical filter (2.56±0.15Hz) using an optical phase conjugation signal in the frequency modulation of a weak probe beam in the presence of two strong counterpropagating pump beams in rhodamine 110 doped boric acid glass thin films (10-4m). Both the pump beams and the probe beam are at a wavelength of 488nm (continuous-wave Ar+ laser). The probe beam frequency was detuned with a ramp signal using a piezoelectric transducer mirror.

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

NASA Astrophysics Data System (ADS)

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

2013-08-01

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

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.

FE-SEM, FIB and TEM Study of Surface Deposits of Apollo 15 Green Glass Volcanic Spherules

NASA Technical Reports Server (NTRS)

Ross, Daniel K.; Thomas-Keprta, K. L.; Rahman, Z.; Wentworth, S. J.; McKay, D. S.

2011-01-01

Surface deposits on lunar pyroclastic green (Apollo 15) and orange (Apollo 17) glass spherules have been attributed to condensation from the gas clouds that accompanied fire-fountain eruptions. The fire fountains cast molten lava high above the lunar surface and the silicate melt droplets quenched before landing producing the glass beads. Early investigations showed that these deposits are rich in sulfur and zinc. The deposits are extremely fine-grained and thin, so that it was never possible to determine their chemical compositions cleanly by SEM/EDX or electron probe x-ray analysis because most of the excited volume was in the under-lying silicate glass. We are investigating the surface deposits by TEM, using focused ion beam (FIB) microscopy to extract and thin the surface deposits. Here we report on chemical mapping of a FIB section of surface deposits of an Apollo green glass bead 15401using the ultra-high resolution JEOL 2500 STEM located at NASA Johnson Space Center.

Geology of National Parks

USGS Publications Warehouse

Stoffer, Philip W.

2008-01-01

This is a set of two sheets of 3D images showing geologic features of many National Parks. Red-and-cyan viewing glasses are need to see the three-dimensional effect. A search on the World Wide Web will yield many sites about anaglyphs and where to get 3D glasses. Red-blue glasses will do but red-cyan glasses are a little better. This publication features a photo quiz game: Name that park! where you can explore, interpret, and identify selected park landscapes. Can you identify landscape features in the images? Can you explain processes that may have helped form the landscape features? You can get the answers online.

Photolithographic Synthesis of High-Density DNA and RNA Arrays on Flexible, Transparent, and Easily Subdivided Plastic Substrates.

PubMed

Holden, Matthew T; Carter, Matthew C D; Wu, Cheng-Hsien; Wolfer, Jamison; Codner, Eric; Sussman, Michael R; Lynn, David M; Smith, Lloyd M

2015-11-17

The photolithographic fabrication of high-density DNA and RNA arrays on flexible and transparent plastic substrates is reported. The substrates are thin sheets of poly(ethylene terephthalate) (PET) coated with cross-linked polymer multilayers that present hydroxyl groups suitable for conventional phosphoramidite-based nucleic acid synthesis. We demonstrate that by modifying array synthesis procedures to accommodate the physical and chemical properties of these materials, it is possible to synthesize plastic-backed oligonucleotide arrays with feature sizes as small as 14 μm × 14 μm and feature densities in excess of 125 000/cm(2), similar to specifications attainable using rigid substrates such as glass or glassy carbon. These plastic-backed arrays are tolerant to a wide range of hybridization temperatures, and improved synthetic procedures are described that enable the fabrication of arrays with sequences up to 50 nucleotides in length. These arrays hybridize with S/N ratios comparable to those fabricated on otherwise identical arrays prepared on glass or glassy carbon. This platform supports the enzymatic synthesis of RNA arrays and proof-of-concept experiments are presented showing that the arrays can be readily subdivided into smaller arrays (or "millichips") using common laboratory-scale laser cutting tools. These results expand the utility of oligonucleotide arrays fabricated on plastic substrates and open the door to new applications for these important bioanalytical tools.

Analyses on the geometrical structure of magnetic field in the current sheet based on cluster measurements

NASA Astrophysics Data System (ADS)

Shen, C.; Li, X.; Dunlop, M.; Liu, Z. X.; Balogh, A.; Baker, D. N.; Hapgood, M.; Wang, X.

2003-05-01

The geometrical structure of the magnetic field is a critical character in the magnetospheric dynamics. Using the magnetic field data measured by the Cluster constellation satellites, the geometrical structure including the curvature radius, directions of curvature, and normal of the osculating planes of the magnetic field lines within the current sheet/neutral sheet have been investigated. The results are (1) Inside of the tail neutral sheet (NS), the curvature of magnetic field lines points towards Earth, the normal of the osculating plane points duskward, and the characteristic half width (or the minimum curvature radius) of the neutral sheet is generally less than 2 RE, for many cases less than 1600 km. (2) Outside of the neutral sheet, the curvature of magnetic field lines pointed northward (southward) at the north (south) side of NS, the normal of the osculating plane points dawnward, and the curvature radius is about 5 RE ˜ 10 RE. (3) Thin NS, where the magnetic field lines have the minimum of the curvature radius less than 0.25 RE, may appear at all the local time between LT 20 hours and 4 hours, but thin NS occurs more frequently near to midnight than that at the dawnside and duskside. (4) The size of the NS is dependent on substorm phases. Generally, the NS is thin during the growth and expansion phases and grows thick during the recovery phase. (5) For the one-dimensional NS, the half thickness and flapping velocity of the NS could be quantitatively determined. Therefore the differential geometry analyses based on Cluster 4-point magnetic measurements open a window for visioning the three-dimensional static and dynamic magnetic field structure of geomagnetosphere.

Unzip instabilities: Straight to oscillatory transitions in the cutting of thin polymer sheets

NASA Astrophysics Data System (ADS)

Reis, P. M.; Kumar, A.; Shattuck, M. D.; Roman, B.

2008-06-01

We report an experimental investigation of the cutting of a thin brittle polymer sheet with a blunt tool. It was recently shown that the fracture path becomes oscillatory when the tool is much wider than the sheet thickness. Here we uncover two novel transitions from straight to oscillatory fracture by varying either the tilt angle of the tool or the speed of cutting, respectively. We denote these by angle and speed unzip instabilities and analyze them by quantifying both the dynamics of the crack tip and the final shapes of the fracture paths. Moreover, for the speed unzip instability, the straight crack lip obtained at low speeds exhibits out-of-plane buckling undulations (as opposed to being flat above the instability threshold) suggesting a transition from ductile to brittle fracture.

Atomically thin two-dimensional organic-inorganic hybrid perovskites.

PubMed

Dou, Letian; Wong, Andrew B; Yu, Yi; Lai, Minliang; Kornienko, Nikolay; Eaton, Samuel W; Fu, Anthony; Bischak, Connor G; Ma, Jie; Ding, Tina; Ginsberg, Naomi S; Wang, Lin-Wang; Alivisatos, A Paul; Yang, Peidong

2015-09-25

Organic-inorganic hybrid perovskites, which have proved to be promising semiconductor materials for photovoltaic applications, have been made into atomically thin two-dimensional (2D) sheets. We report the solution-phase growth of single- and few-unit-cell-thick single-crystalline 2D hybrid perovskites of (C4H9NH3)2PbBr4 with well-defined square shape and large size. In contrast to other 2D materials, the hybrid perovskite sheets exhibit an unusual structural relaxation, and this structural change leads to a band gap shift as compared to the bulk crystal. The high-quality 2D crystals exhibit efficient photoluminescence, and color tuning could be achieved by changing sheet thickness as well as composition via the synthesis of related materials. Copyright © 2015, American Association for the Advancement of Science.