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Sample records for activity sheets transparency

  1. Selectively reflective transparent sheets

    NASA Astrophysics Data System (ADS)

    Waché, Rémi; Florescu, Marian; Sweeney, Stephen J.; Clowes, Steven K.

    2015-08-01

    We investigate the possibility to selectively reflect certain wavelengths while maintaining the optical properties on other spectral ranges. This is of particular interest for transparent materials, which for specific applications may require high reflectivity at pre-determined frequencies. Although there exist currently techniques such as coatings to produce selective reflection, this work focuses on new approaches for mass production of polyethylene sheets which incorporate either additives or surface patterning for selective reflection between 8 to 13 μ m. Typical additives used to produce a greenhouse effect in plastics include particles such as clays, silica or hydroxide materials. However, the absorption of thermal radiation is less efficient than the decrease of emissivity as it can be compared with the inclusion of Lambertian materials. Photonic band gap engineering by the periodic structuring of metamaterials is known in nature for producing the vivid bright colors in certain organisms via strong wavelength-selective reflection. Research to artificially engineer such structures has mainly focused on wavelengths in the visible and near infrared. However few studies to date have been carried out to investigate the properties of metastructures in the mid infrared range even though the patterning of microstructure is easier to achieve. We present preliminary results on the diffuse reflectivity using FDTD simulations and analyze the technical feasibility of these approaches.

  2. Mirage Effect From Thermally-Modulated Transparent Carbon Nanotube Sheet

    NASA Astrophysics Data System (ADS)

    Aliev, Ali; Baughman, Ray

    2011-03-01

    The single beam mirage effect, also known as photothermal deflection, is studied using a free-standing, highly-aligned carbon nanotube sheet as a heat source whose temperature can be modulated over a wide frequency range. The extremely low thermal capacitance and high heat transfer ability of these transparent forest-drawn carbon nanotube sheets enables high frequency modulation of sheet temperature over an enormous temperature range, thereby providing a sharp, rapidly changing gradient of refractive index in surrounding liquid or gas. The advantages of temperature modulation using carbon nanotube sheets are multiple: in inert gases the temperature can reach > 2500 K ; theobtainedfrequencyrangeforphotothermalmodulationis ~ 100 kHz in gases and over 100 Hz in high refractive index liquids; and the heat source is transparent for optical and acoustical waves. The remarkable light deflection in gases and liquids suggests possible application of carbon nanotube sheets for large laser projectors and cloaking systems.

  3. Synthesis of Graphene Sheets and Their Application for Transparent Conductors

    NASA Astrophysics Data System (ADS)

    Zheng, Qingbin

    Graphene, a monolayer of sp2-bonded carbon atoms or one monolayer of graphite, has a special atomically thick two dimensional structure and possesses unique mechanical, electrical, thermal and optical properties. These properties make graphene a good candidate material for transparent conductors. Monolayer graphene oxide (GO) sheets with sizes ranging from a few to ˜200 mum are synthesized based on a chemical method. In order to obtain ultra-large graphene oxide (UL-GO), three main modifications were made in our experiments: i) using the natural graphite with a large lateral size (up to ˜800 mum) as starting material; ii) using intercalation and thermal shock to perform exfoliation, avoiding the destructive process of ultrasonication; iii) using a three-step centrifugation to sort the GO by sheet size. New thermal and chemical schemes, which include (i) a modified thermal treatment, (ii) acid treatment in a HNO3 bath and (iii) doping by immersing in a SOBr2 solution, are developed to treat graphene films to improve the electrical conductivity and transparency. It is shown that a longer thermal treatment at 1100 °C as well as additional acid and doping treatments reduce the sheet resistance by about 20--50% with improved transmittance. The final product has a sheet resistance of 1600 O/sq and a transparency of 82%, which is quite sufficient to replace the transparent conducting films made from indium tin oxide for many existing applications in photovoltaic cells and optoelectronics. The transmittance and sheet resistance measured after 3 months of exposure to air confirms the stability of the improved characteristics after the additional treatments. Transparent conductive films are produced using the ultra-large graphene oxide (UL-GO) sheets that are deposited layer-by-layer on a substrate using the Langmuir-Blodgett (L-B) assembly technique. The density and degree of wrinkling of the UL-GO monolayers are turned from dilute, close-packed flat UL-GO to graphene

  4. Mirage effect from thermally modulated transparent carbon nanotube sheets

    NASA Astrophysics Data System (ADS)

    Aliev, Ali E.; Gartstein, Yuri N.; Baughman, Ray H.

    2011-10-01

    The single-beam mirage effect, also known as photothermal deflection, is studied using a free-standing, highly aligned carbon nanotube aerogel sheet as the heat source. The extremely low thermal capacitance and high heat transfer ability of these transparent forest-drawn carbon nanotube sheets enables high frequency modulation of sheet temperature over an enormous temperature range, thereby providing a sharp, rapidly changing gradient of refractive index in the surrounding liquid or gas. The advantages of temperature modulation using carbon nanotube sheets are multiple: in inert gases the temperature can reach > 2500 K the obtained frequency range for photothermal modulation is ~ 100 kHz in gases and over 100 Hz in high refractive index liquids; and the heat source is transparent for optical and acoustical waves. Unlike for conventional heat sources for photothermal deflection, the intensity and phase of the thermally modulated beam component linearly depends upon the beam-to-sheet separation over a wide range of distances. This aspect enables convenient measurements of accurate values for thermal diffusivity and the temperature dependence of refractive index for both liquids and gases. The remarkable performance of nanotube sheets suggests possible applications as photo-deflectors and for switchable invisibility cloaks, and provides useful insights into their use as thermoacoustic projectors and sonar. Visibility cloaking is demonstrated in a liquid.

  5. Mirage effect from thermally modulated transparent carbon nanotube sheets.

    PubMed

    Aliev, Ali E; Gartstein, Yuri N; Baughman, Ray H

    2011-10-28

    The single-beam mirage effect, also known as photothermal deflection, is studied using a free-standing, highly aligned carbon nanotube aerogel sheet as the heat source. The extremely low thermal capacitance and high heat transfer ability of these transparent forest-drawn carbon nanotube sheets enables high frequency modulation of sheet temperature over an enormous temperature range, thereby providing a sharp, rapidly changing gradient of refractive index in the surrounding liquid or gas. The advantages of temperature modulation using carbon nanotube sheets are multiple: in inert gases the temperature can reach > 2500 K; the obtained frequency range for photothermal modulation is ~100 kHz in gases and over 100 Hz in high refractive index liquids; and the heat source is transparent for optical and acoustical waves. Unlike for conventional heat sources for photothermal deflection, the intensity and phase of the thermally modulated beam component linearly depends upon the beam-to-sheet separation over a wide range of distances. This aspect enables convenient measurements of accurate values for thermal diffusivity and the temperature dependence of refractive index for both liquids and gases. The remarkable performance of nanotube sheets suggests possible applications as photo-deflectors and for switchable invisibility cloaks, and provides useful insights into their use as thermoacoustic projectors and sonar. Visibility cloaking is demonstrated in a liquid. PMID:21967888

  6. Tunable plasmon-induced transparency with graphene-sheet structure

    NASA Astrophysics Data System (ADS)

    Wang, Yueke; Shen, Xinru; Chen, Quansheng

    2016-07-01

    We investigate theoretically and numerically the tunable plasmon-induced transparency (PIT) phenomenon in graphene-sheet system in infrared range. We show that when surface plasmon polaritons (SPPs) propagate along a monolayer graphene sheet with two detuned side-coupled resonators, the PIT-like transmission spectra of SPPs appear. Thanks to the tunable permittivity of graphene by bias voltages, the resonant wavelength of side-coupled resonators can be changed. So the transmission spectra can be tuned dynamically and the tunable PIT phenomenon is achieved. Numerical simulation by finite element method is conducted to verify our design.

  7. Flexible modulation of plasmon-induced transparency in a strongly coupled graphene grating-sheet system.

    PubMed

    Luo, Weiwei; Cai, Wei; Xiang, Yinxiao; Wang, Lei; Ren, Mengxin; Zhang, Xinzheng; Xu, Jingjun

    2016-03-21

    General actively tunable near-field plasmon-induced transparency (PIT) systems based on couplings between localized plasmon resonances of graphene nanostructures not only suffer from interantenna separations of smaller than 20 nm, but also lack switchable effect about the transparency window. Here, the performance of an active PIT system based on graphene grating-sheet with near-field coupling distance of more than 100 nm is investigated in mid-infrared. The transparency window in spectrum is analyzed objectively and proved to be more likely stemmed from Aulter-Townes splitting. The proposed system exhibits flexible tunability in slow-light and electro-optical switches, promising for practical active photonic devices. PMID:27136776

  8. High-performance transparent and stretchable all-solid supercapacitors based on highly aligned carbon nanotube sheets

    PubMed Central

    Chen, Tao; Peng, Huisheng; Durstock, Michael; Dai, Liming

    2014-01-01

    By using highly aligned carbon nanotube (CNT) sheets of excellent optical transmittance and mechanical stretchability as both the current collector and active electrode, high-performance transparent and stretchable all-solid supercapacitors with a good stability were developed. A transmittance up to 75% at the wavelength of 550 nm was achieved for a supercapacitor made from a cross-over assembly of two single-layer CNT sheets. The transparent supercapacitor has a specific capacitance of 7.3 F g−1 and can be biaxially stretched up to 30% strain without any obvious change in electrochemical performance even over hundreds stretching cycles. PMID:24402400

  9. Physical process in OLED architectures with transparent carbon nanotube sheets as electrodes

    NASA Astrophysics Data System (ADS)

    Ovalle Robles, Raquel

    There has been a great deal of activity in the development of organic light emitting diodes (OLED's) and polymeric light emitting diodes (PLED's). Research in OLEDs and PLEDs have been having a significant development over the last few years towards commercialization, extended life time, stability, efficiency and new fabrication processes suitable for mass production are some of the topics. The potential for commercialization is high due to their low operating voltage (typically between 2.5 to 5 volts), their high brightness and their ease to process. They are light weight and can be flexible. Furthermore, these devices can be easily color tune to produce red, green and blue colors. Research in this type of electroluminescence devices has advanced rapidly and device prototypes now meet realistic specifications for applications. By proper device engineering these devices can achieve high electroluminescence efficiencies and lifetimes. In this research project we present several methods and procedures that we developed and use to produce OLEDs and PLEDs. We have incorporated quantum dots into OLEDs as emissive dopants that contribute to the control of the spectral distribution of emitted light allowing the production of white OLEDs using both a multilayer structure with emission from multiple layers and a bilayer structure with emission from only the quantum dots. We have also produced PLED devices with a new family of novel PPV polymers achieving high bright efficient devices. OLED structures with transparent carbon nanotube sheets, obtained by dry drawing from a CVD-grown forest have been produced. The devices shown to be very bright and the MCNT sheets are efficient hole-injecting anodes for OLEDs Also, for flexible display applications, there is a need for high strength, flexible materials which can be deposited as transparent films and can act as hole injectors for organic films. By using a hybrid ITO/MWCNT anode onto flexible substrates an enhancement of the

  10. Transparent actuators and robots based on single-layer superaligned carbon nanotube sheet and polymer composites.

    PubMed

    Chen, Luzhuo; Weng, Mingcen; Zhang, Wei; Zhou, Zhiwei; Zhou, Yi; Xia, Dan; Li, Jiaxin; Huang, Zhigao; Liu, Changhong; Fan, Shoushan

    2016-03-28

    Transparent actuators have been attracting emerging interest recently, as they demonstrate potential applications in the fields of invisible robots, tactical displays, variable-focus lenses, and flexible cellular phones. However, previous technologies did not simultaneously realize macroscopic transparent actuators with advantages of large-shape deformation, low-voltage-driven actuation and fast fabrication. Here, we develop a fast approach to fabricate a high-performance transparent actuator based on single-layer superaligned carbon nanotube sheet and polymer composites. Various advantages of single-layer nanotube sheets including high transparency, considerable conductivity, and ultra-thin dimensions together with selected polymer materials completely realize all the above required advantages. Also, this is the first time that a single-layer nanotube sheet has been used to fabricate actuators with high transparency, avoiding the structural damage to the single-layer nanotube sheet. The transparent actuator shows a transmittance of 72% at the wavelength of 550 nm and bends remarkably with a curvature of 0.41 cm(-1) under a DC voltage for 5 s, demonstrating a significant advance in technological performances compared to previous conventional actuators. To illustrate their great potential usage, a transparent wiper and a humanoid robot "hand" were elaborately designed and fabricated, which initiate a new direction in the development of high-performance invisible robotics and other intelligent applications with transparency. PMID:26959343

  11. Transparent actuators and robots based on single-layer superaligned carbon nanotube sheet and polymer composites

    NASA Astrophysics Data System (ADS)

    Chen, Luzhuo; Weng, Mingcen; Zhang, Wei; Zhou, Zhiwei; Zhou, Yi; Xia, Dan; Li, Jiaxin; Huang, Zhigao; Liu, Changhong; Fan, Shoushan

    2016-03-01

    Transparent actuators have been attracting emerging interest recently, as they demonstrate potential applications in the fields of invisible robots, tactical displays, variable-focus lenses, and flexible cellular phones. However, previous technologies did not simultaneously realize macroscopic transparent actuators with advantages of large-shape deformation, low-voltage-driven actuation and fast fabrication. Here, we develop a fast approach to fabricate a high-performance transparent actuator based on single-layer superaligned carbon nanotube sheet and polymer composites. Various advantages of single-layer nanotube sheets including high transparency, considerable conductivity, and ultra-thin dimensions together with selected polymer materials completely realize all the above required advantages. Also, this is the first time that a single-layer nanotube sheet has been used to fabricate actuators with high transparency, avoiding the structural damage to the single-layer nanotube sheet. The transparent actuator shows a transmittance of 72% at the wavelength of 550 nm and bends remarkably with a curvature of 0.41 cm-1 under a DC voltage for 5 s, demonstrating a significant advance in technological performances compared to previous conventional actuators. To illustrate their great potential usage, a transparent wiper and a humanoid robot ``hand'' were elaborately designed and fabricated, which initiate a new direction in the development of high-performance invisible robotics and other intelligent applications with transparency.Transparent actuators have been attracting emerging interest recently, as they demonstrate potential applications in the fields of invisible robots, tactical displays, variable-focus lenses, and flexible cellular phones. However, previous technologies did not simultaneously realize macroscopic transparent actuators with advantages of large-shape deformation, low-voltage-driven actuation and fast fabrication. Here, we develop a fast approach to

  12. 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. PMID:26809104

  13. Activity Sheets. Draft Copy.

    ERIC Educational Resources Information Center

    Duke Power Company, Educational Services Dept., Charlotte, NC.

    This document consists of energy vocabulary activities, three games, worksheets, laboratory activities/exercises, and an introductory classroom exercise designed to introduce energy concepts to students. Vocabulary activities focus on coal and energy consumption. The three games (with instructions) focus on various aspects of energy and energy…

  14. Lens-fibre interference proposed to monitor a transparent sheet's thickness variations

    NASA Astrophysics Data System (ADS)

    Ramadan, W. A.; Shams El-Din, M. A.; Wahba, H. H.; El-Tawargy, A. S.; Hamza, A. A.

    2014-12-01

    The lens-fibre interference (LFI) technique is used for monitoring thickness variations of a known refractive index transparent sheet. The sheet is inserted in the light path between the cylindrical lens and the fibre, in the LFI optical arrangement. A phase change and a geometrical shift for the beam passed through the sheet are observed. The presence of the sheet is considered in the ray tracing model which explained LFI (J. Opt. A: Pure Appl. Opt. 2:234-238, 2000). So, we are able to reproduce the interference pattern, in the presence of the sheet, theoretically. Depending on the width of the incident light spot on the cylindrical lens, a three beams interference could be observed. A development of the previous model is presented taking into account the third interfered beam. The produced interference pattern is a good indicator to the sheet's thickness variations, especially when we considered the occurred three beams interference. Some investigations about the uncertainty analyses in our measurements are presented.

  15. Environmental Education Activity Sheets 1-11.

    ERIC Educational Resources Information Center

    Halsey, Clifton F.; And Others

    These activity sheets, developed by personnel of the Agricultural Extension Service of the University of Minnesota, were designed for youth group campers but may be used by other populations and individuals. Each activity sheet focuses on a separate topic: (1) Selecting Suitable Uses for Land, (2) Measuring the Steepness of Land, (3) Determining…

  16. Improved Transparent Conducting Oxides Boost Performance of Thin-Film Solar Cells (Fact Sheet)

    SciTech Connect

    Not Available

    2011-02-01

    Today?s thin-film solar cells could not function without transparent conducting oxides (TCOs). TCOs act as a window, both protecting the cell and allowing light to pass through to the cell?s active layers. Until recently, TCOs were seen as a necessary, but static, layer of a thin-film photovoltaic (PV) cell. But a group of researchers at the National Renewable Energy Laboratory (NREL) has identified a pathway to producing improved TCO films that demonstrate higher infrared transparency. To do so, they have modified the TCOs in ways that did not seem possible a few years ago.

  17. Organic solar cells using few-walled carbon nanotubes electrode controlled by the balance between sheet resistance and the transparency

    NASA Astrophysics Data System (ADS)

    Feng, Yiyu; Ju, Xiaohui; Feng, Wei; Zhang, Hongbo; Cheng, Yingwen; Liu, Jie; Fujii, Akihiko; Ozaki, Masanori; Yoshino, Katsumi

    2009-03-01

    Organic photovoltaic devices (OPD) using high conductive transparent few-walled carbon nanotubes (FWNT) film prepared by spraying was fabricated as a selective hole collection. Photovoltaic response with different sheet resistance (Rs) and the transparency (T) of FWNT film was investigated. Maximum efficiency of OPD up to 0.61% with the structure of FWNT (T =70%, Rs=86 Ω/◻)/poly(3-hexylthiophene): [6-6]phenyl-C61-butyric acid methyl ester/Al demonstrates a promising alternative of ITO (0.68%) with almost identical operation. The performance improvement results from the optimal balance between sheet resistance and transparency with three-dimensional network interface between nanotubes and polymers.

  18. Transparency

    ERIC Educational Resources Information Center

    LaFee, Scott

    2009-01-01

    Citizens now expect access to information, particularly from public institutions like local school districts. They demand input and accountability. Cultural and technological changes, such as the Internet, make it possible for districts to comply. Yet transparency--the easily seen and understood actions of a school district and the thinking behind…

  19. Effects of length dispersity and film fabrication on the sheet resistance of copper nanowire transparent conductors

    NASA Astrophysics Data System (ADS)

    Borchert, James W.; Stewart, Ian E.; Ye, Shengrong; Rathmell, Aaron R.; Wiley, Benjamin J.; Winey, Karen I.

    2015-08-01

    Development of thin-film transparent conductors (TC) based on percolating networks of metal nanowires has leaped forward in recent years, owing to the improvement of nanowire synthetic methods and modeling efforts by several research groups. While silver nanowires are the first commercially viable iteration of this technology, systems based on copper nanowires are not far behind. Here we present an analysis of TCs composed of copper nanowire networks on sheets of polyethylene terephthalate that have been treated with various oxide-removing post treatments to improve conductivity. A pseudo-2D rod network modeling approach has been modified to include lognormal distributions in length that more closely reflect experimental data collected from the nanowire TCs. In our analysis, we find that the copper nanowire TCs are capable of achieving comparable electrical performance to silver nanowire TCs with similar dimensions. Lastly, we present a method for more accurately determining the nanowire area coverage in a TC over a large area using Rutherford Backscattering Spectrometry (RBS) to directly measure the metal content in the TCs. These developments will aid research and industry groups alike in the characterization of nanowire based TCs.Development of thin-film transparent conductors (TC) based on percolating networks of metal nanowires has leaped forward in recent years, owing to the improvement of nanowire synthetic methods and modeling efforts by several research groups. While silver nanowires are the first commercially viable iteration of this technology, systems based on copper nanowires are not far behind. Here we present an analysis of TCs composed of copper nanowire networks on sheets of polyethylene terephthalate that have been treated with various oxide-removing post treatments to improve conductivity. A pseudo-2D rod network modeling approach has been modified to include lognormal distributions in length that more closely reflect experimental data collected

  20. Projection type transparent 3D display using active screen

    NASA Astrophysics Data System (ADS)

    Kamoshita, Hiroki; Yendo, Tomohiro

    2015-05-01

    Equipment to enjoy a 3D image, such as a movie theater, television and so on have been developed many. So 3D video are widely known as a familiar image of technology now. The display representing the 3D image are there such as eyewear, naked-eye, the HMD-type, etc. They has been used for different applications and location. But have not been widely studied for the transparent 3D display. If transparent large 3D display is realized, it is useful to display 3D image overlaid on real scene in some applications such as road sign, shop window, screen in the conference room etc. As a previous study, to produce a transparent 3D display by using a special transparent screen and number of projectors is proposed. However, for smooth motion parallax, many projectors are required. In this paper, we propose a display that has transparency and large display area by time multiplexing projection image in time-division from one or small number of projectors to active screen. The active screen is composed of a number of vertically-long small rotate mirrors. It is possible to realize the stereoscopic viewing by changing the image of the projector in synchronism with the scanning of the beam.3D vision can be realized by light is scanned. Also, the display has transparency, because it is possible to see through the display when the mirror becomes perpendicular to the viewer. We confirmed the validity of the proposed method by using simulation.

  1. Sequential Folding using Light-activated Polystyrene Sheet

    PubMed Central

    Lee, Yonghee; Lee, Hyeok; Hwang, Taesoon; Lee, Jong-Gu; Cho, Maenghyo

    2015-01-01

    A pre-strained polystyrene (PS) polymer sheet is deformed when it approaches the glass transition state as a result of light absorption. By controlling the light absorption of the polymer sheet, non-contact sequential folding can be accomplished. Line patterns of different transparencies and shapes are used to control the light absorption. The line pattern shape is closely related to the folding angle and folding start time. The relation between the line pattern design and folding performance was evaluated experimentally to develop a technique for folding PS sheets. The results show that sequential folding of PS sheets can be accomplished by changing the degree of transparency of the line pattern. Using the technique developed in this study, self-folding origami structures with complicated shapes can be designed and manufactured. PMID:26559611

  2. ZnO:H indium-free transparent conductive electrodes for active-matrix display applications

    SciTech Connect

    Chen, Shuming Wang, Sisi

    2014-12-01

    Transparent conductive electrodes based on hydrogen (H)-doped zinc oxide (ZnO) have been proposed for active-matrix (AM) display applications. When fabricated with optimal H plasma power and optimal plasma treatment time, the resulting ZnO:H films exhibit low sheet resistance of 200 Ω/◻ and high average transmission of 85% at a film thickness of 150 nm. The demonstrated transparent conductive ZnO:H films can potentially replace indium-tin-oxide and serve as pixel electrodes for organic light-emitting diodes as well as source/drain electrodes for ZnO-based thin-film transistors. Use of the proposed ZnO:H electrodes means that two photomask stages can be removed from the fabrication process flow for ZnO-based AM backplanes.

  3. ZnO:H indium-free transparent conductive electrodes for active-matrix display applications

    NASA Astrophysics Data System (ADS)

    Chen, Shuming; Wang, Sisi

    2014-12-01

    Transparent conductive electrodes based on hydrogen (H)-doped zinc oxide (ZnO) have been proposed for active-matrix (AM) display applications. When fabricated with optimal H plasma power and optimal plasma treatment time, the resulting ZnO:H films exhibit low sheet resistance of 200 Ω/◻ and high average transmission of 85% at a film thickness of 150 nm. The demonstrated transparent conductive ZnO:H films can potentially replace indium-tin-oxide and serve as pixel electrodes for organic light-emitting diodes as well as source/drain electrodes for ZnO-based thin-film transistors. Use of the proposed ZnO:H electrodes means that two photomask stages can be removed from the fabrication process flow for ZnO-based AM backplanes.

  4. Improvement of device performance of polymer organic light-emitting diodes on smooth transparent sheet with graphene films synthesized by plasma treatment

    NASA Astrophysics Data System (ADS)

    Okigawa, Yuki; Mizutani, Wataru; Suzuki, Kenkichi; Ishihara, Masatou; Yamada, Takatoshi; Hasegawa, Masataka

    2015-09-01

    Because graphene films have one-atom thickness, the morphology of the transparent sheets could have a greater effect on the performance of organic light-emitting diode (OLED) devices with graphene films than on that with indium tin oxide (ITO). In this study, we have evaluated the polymer OLED devices with graphene films synthesized by plasma treatment on poly(ethylene terephthalate) (PET) and poly(ethylene naphthalate) (PEN) sheets having high flatness. The results imply that the surface roughness of the transparent sheets predominantly affects the luminescence of polymer OLED devices with graphene films. The suppression of leakage current and a luminescence higher than 8000 cd/m2 at 15 V were attained for the devices on the transparent sheet with higher flatness in spite of the presence of large sharp spikes.

  5. Ice stream activity scaled to ice sheet volume during Laurentide Ice Sheet deglaciation.

    PubMed

    Stokes, C R; Margold, M; Clark, C D; Tarasov, L

    2016-02-18

    The contribution of the Greenland and West Antarctic ice sheets to sea level has increased in recent decades, largely owing to the thinning and retreat of outlet glaciers and ice streams. This dynamic loss is a serious concern, with some modelling studies suggesting that the collapse of a major ice sheet could be imminent or potentially underway in West Antarctica, but others predicting a more limited response. A major problem is that observations used to initialize and calibrate models typically span only a few decades, and, at the ice-sheet scale, it is unclear how the entire drainage network of ice streams evolves over longer timescales. This represents one of the largest sources of uncertainty when predicting the contributions of ice sheets to sea-level rise. A key question is whether ice streams might increase and sustain rates of mass loss over centuries or millennia, beyond those expected for a given ocean-climate forcing. Here we reconstruct the activity of 117 ice streams that operated at various times during deglaciation of the Laurentide Ice Sheet (from about 22,000 to 7,000 years ago) and show that as they activated and deactivated in different locations, their overall number decreased, they occupied a progressively smaller percentage of the ice sheet perimeter and their total discharge decreased. The underlying geology and topography clearly influenced ice stream activity, but--at the ice-sheet scale--their drainage network adjusted and was linked to changes in ice sheet volume. It is unclear whether these findings can be directly translated to modern ice sheets. However, contrary to the view that sees ice streams as unstable entities that can accelerate ice-sheet deglaciation, we conclude that ice streams exerted progressively less influence on ice sheet mass balance during the retreat of the Laurentide Ice Sheet. PMID:26887494

  6. 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 Central

    Kou, Kuang-Yang; Huang, Yu-En; Chen, Chien-Hsun

    2016-01-01

    Summary 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. PMID:26925355

  7. 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. PMID:26925355

  8. Transparent electrical conducting films by activated reactive evaporation

    DOEpatents

    Bunshah, Rointan; Nath, Prem

    1982-01-01

    Process and apparatus for producing transparent electrical conducting thin films by activated reactive evaporation. Thin films of low melting point metals and alloys, such as indium oxide and indium oxide doped with tin, are produced by physical vapor deposition. The metal or alloy is vaporized by electrical resistance heating in a vacuum chamber, oxygen and an inert gas such as argon are introduced into the chamber, and vapor and gas are ionized by a beam of low energy electrons in a reaction zone between the resistance heater and the substrate. There is a reaction between the ionized oxygen and the metal vapor resulting in the metal oxide which deposits on the substrate as a thin film which is ready for use without requiring post deposition heat treatment.

  9. Transparent electrical conducting films by activated reactive evaporation

    DOEpatents

    Bunshah, R.; Nath, P.

    1982-06-22

    Process and apparatus for producing transparent electrical conducting thin films by activated reactive evaporation is disclosed. Thin films of low melting point metals and alloys, such as indium oxide and indium oxide doped with tin, are produced by physical vapor deposition. The metal or alloy is vaporized by electrical resistance heating in a vacuum chamber, oxygen and an inert gas such as argon are introduced into the chamber, and vapor and gas are ionized by a beam of low energy electrons in a reaction zone between the resistance heater and the substrate. There is a reaction between the ionized oxygen and the metal vapor resulting in the metal oxide which deposits on the substrate as a thin film which is ready for use without requiring post deposition heat treatment. 1 fig.

  10. Transparent, conductive, and SERS-active Au nanofiber films assembled on an amphiphilic peptide template

    NASA Astrophysics Data System (ADS)

    Vinod, T. P.; Zarzhitsky, Shlomo; Morag, Ahiud; Zeiri, Leila; Levi-Kalisman, Yael; Rapaport, Hanna; Jelinek, Raz

    2013-10-01

    The use of biological materials as templates for functional molecular assemblies is an active research field at the interface between chemistry, biology, and materials science. We demonstrate the formation of gold nanofiber films on β-sheet peptide domains assembled at the air/water interface. The gold deposition scheme employed a recently discovered chemical process involving spontaneous crystallization and reduction of water-soluble Au(SCN)41- upon anchoring to surface-displayed amine moieties. Here we show that an interlinked network of crystalline Au nanofibers is readily formed upon incubation of the Au(iii) thiocyanate complex with the peptide monolayers. Intriguingly, the resultant films were optically transparent, enabled electrical conductivity, and displayed pronounced surface enhanced Raman spectroscopy (SERS) activity, making the approach a promising avenue for construction of nano-structured films exhibiting practical applications.The use of biological materials as templates for functional molecular assemblies is an active research field at the interface between chemistry, biology, and materials science. We demonstrate the formation of gold nanofiber films on β-sheet peptide domains assembled at the air/water interface. The gold deposition scheme employed a recently discovered chemical process involving spontaneous crystallization and reduction of water-soluble Au(SCN)41- upon anchoring to surface-displayed amine moieties. Here we show that an interlinked network of crystalline Au nanofibers is readily formed upon incubation of the Au(iii) thiocyanate complex with the peptide monolayers. Intriguingly, the resultant films were optically transparent, enabled electrical conductivity, and displayed pronounced surface enhanced Raman spectroscopy (SERS) activity, making the approach a promising avenue for construction of nano-structured films exhibiting practical applications. Electronic supplementary information (ESI) available: AFM analysis of the

  11. Active volcanism beneath the West Antarctic ice sheet and implications for ice-sheet stability

    USGS Publications Warehouse

    Blankenship, D.D.; Bell, R.E.; Hodge, S.M.; Brozena, J.M.; Behrendt, John C.; Finn, C.A.

    1993-01-01

    IT is widely understood that the collapse of the West Antarctic ice sheet (WAIS) would cause a global sea level rise of 6 m, yet there continues to be considerable debate about the detailed response of this ice sheet to climate change1-3. Because its bed is grounded well below sea level, the stability of the WAIS may depend on geologically controlled conditions at the base which are independent of climate. In particular, heat supplied to the base of the ice sheet could increase basal melting and thereby trigger ice streaming, by providing the water for a lubricating basal layer of till on which ice streams are thought to slide4,5. Ice streams act to protect the reservoir of slowly moving inland ice from exposure to oceanic degradation, thus enhancing ice-sheet stability. Here we present aerogeophysical evidence for active volcanism and associated elevated heat flow beneath the WAIS near the critical region where ice streaming begins. If this heat flow is indeed controlling ice-stream formation, then penetration of ocean waters inland of the thin hot crust of the active portion of the West Antarctic rift system could lead to the disappearance of ice streams, and possibly trigger a collapse of the inland ice reservoir.

  12. Transparent Conducting Nb-Doped TiO2 Electrodes Activated by Laser Annealing for Inexpensive Flexible Organic Solar Cells

    NASA Astrophysics Data System (ADS)

    Lee, Jung-Hsiang; Lin, Chia-Chi; Lin, Yi-Chang

    2012-01-01

    A KrF excimer laser (λ= 248 nm) has been adopted for annealing cost-effective Nb-doped TiO2 (NTO) films. Sputtered NTO layers were annealed on SiO2-coated flexible poly(ethylene terephthalate) (PET) substrates. This local laser annealing technique is very useful for the formation of anatase NTO electrodes used in flexible organic solar cells (OSCs). An amorphous NTO film with a high resistivity and a low transparency was transformed significantly into a conductive and transparent anatase NTO electrode by laser irradiation. The 210 nm anatase NTO film shows a sheet resistance of 50 Ω and an average optical transmittance of 83.5% in the wavelength range from 450 to 600 nm after annealing at 0.25 J/cm2. The activation of Nb dopants and the formation of the anatase phase contribute to the high conductivity of the laser-annealed NTO electrode. Nb activation causes an increase in the optical band gap due to the Burstein-Moss effect. The electrical properties are in agreement with the material characteristics determined by X-ray diffraction (XRD) analysis and secondary ion mass spectrometry (SIMS). The irradiation energy for the NTO electrode also affects the performance of the organic solar cell. The laser annealing technique provides good properties of the anatase NTO film used as a transparent electrode for flexible organic solar cells (OSCs) without damage to the PET substrate or layer delamination from the substrate.

  13. Career Orientation 7-8. Student Activity Sheets in Economics.

    ERIC Educational Resources Information Center

    Flowers, E. L.

    Activity sheets for seventh and eighth grade student use in economics are contained in this document. Activities are developed in the following areas: checking accounts, bank account applications, check writing, keeping a check register, using checks, budgets, insurance, responsibility and planning, consumer shopping, supermarkets, taxes, help…

  14. Toward transparent and self-activated graphene harmonic transponder sensors

    NASA Astrophysics Data System (ADS)

    Huang, Haiyu Harry; Sakhdari, Maryam; Hajizadegan, Mehdi; Shahini, Ali; Akinwande, Deji; Chen, Pai-Yen

    2016-04-01

    We propose the concept and design of a transparent, flexible, and self-powered wireless sensor comprising a graphene-based sensor/frequency-modulator circuitry and a graphene antenna. In this all-graphene device, the multilayered-graphene antenna receives the fundamental tone at C band and retransmits the frequency-modulated sensed signal (harmonic tone) at X band. The frequency orthogonality between the received/re-transmitted signals may enable high-performance sensing in severe interference/clutter background. Here, a fully passive, quad-ring frequency multiplier is proposed using graphene field-effect transistors, of which the unique ambipolar charge transports render a frequency doubling effect with conversion gain being chemically sensitive to exposed gas/molecular/chemical/infectious agents. This transparent, light-weight, and self-powered system may potentially benefit a number of wireless sensing and diagnosis applications, particularly for smart contact lenses/glasses and microscope slides that require high optical transparency.

  15. Features of the Active Evening Plasma Sheet from MMS

    NASA Astrophysics Data System (ADS)

    Moore, T. E.; Chandler, M. O.; Avanov, L. A.; Burch, J. L.; Coffey, V. N.; Ergun, R. E.; Fuselier, S. A.; Gershman, D. J.; Giles, B. L.; Lavraud, B.; MacDonald, E.; Mauk, B.; Mukai, T.; Nakamura, R.; Pollock, C. J.; Russell, C. T.; Saito, Y.; Sauvaud, J. A.; Torbert, R. B.; Yokota, S.

    2015-12-01

    The Magnetospheric Multiscale (MMS) mission, consisting of four identical plasmas and fields observatories, was launched into a 12 RE elliptical equatorial orbit in March 2015 and was in the process of being commissioned through August 2015. During commissioning, the orbit apogee rotated from near midnight through the evening toward the dusk sector and occasionally captured new observations of the plasma sheet, its boundary layers, and the magnetospheric tail lobes. On 22-23 June, an especially active plasma sheet was involved in a major geospace storm that developed a ring current with 200 nT DST. We report on the ion kinetic and flow features of this active plasma sheet, comparing them with familiar observations from earlier missions, as an exercise in validating the MMS observations and assessing their capabilities to provide higher time resolution in multi-point views of thin, fast-moving structures. The observed features include but are not limited to cold lobal wind streams in the lobes, tailward flowing auroral beams and conics, hot earthward field-aligned flows and counter-flows, fast cross-field convection of some flows toward the neutral sheet, and the hot isotropic plasma sheet proper. Relationships between these features, the ionosphere, and the reconnecting magnetotail will be explored and discussed, seeking preliminary conclusions.

  16. Donor-acceptor organo-imido polyoxometalates: high transparency, high activity redox-active NLO chromophores.

    PubMed

    Al-Yasari, Ahmed; Van Steerteghem, Nick; El Moll, Hani; Clays, Koen; Fielden, John

    2016-02-21

    We show that polyoxometalates (POMs) are an excellent redox-active acceptor on which to base high performance 2(nd) order non-linear optical (NLO) chromophores. This is demonstrated through three new organoimido-Lindqvist derivatives with HRS β0-values exceeding those of any dipolar organic system with comparable donor, π-system and absorption profile. Thus, organoimido POMs may provide a new generation of high performance, high transparency, and potentially redox-switchable NLO materials. PMID:26815652

  17. EERE-Supported International Activities in Latin America (Fact Sheet)

    SciTech Connect

    Not Available

    2010-05-01

    The Office of Energy Efficiency and Renewable Energy (EERE) is involved in a variety of international initiatives, partnerships, and events that promote greater understanding and use of renewable energy (RE) and energy efficiency (EE) worldwide. In support of the Energy and Climate Partnership of the Americas (ECPA), EERE is working with several Latin American countries to advance EE and RE deployment for economic growth, energy security, poverty relief, and disaster recovery goals. This fact sheet highlights those activities.

  18. Nanostructured p-type semiconducting transparent oxides: promising materials for nano-active devices and the emerging field of "transparent nanoelectronics".

    PubMed

    Banerjee, Arghya; Chattopadhyay, Kalyan K

    2008-01-01

    Transparent conducting oxides (TCO) with p-type semiconductivity have recently gained renewed interest for the fabrication of all-oxide transparent junctions, having potential applications in the emerging field of 'Transparent' or 'Invisible Electronics'. This kind of transparent junctions can be used as a "functional" window, which will transmit visible portion of solar radiation, but generates electricity by the absorption of the UV part. Therefore, these devices can be used as UV shield as well as UV cells. In this report, a brief review on the research activities on various p-TCO materials is furnished along-with the fabrication of different transparent p-n homojunction, heterojunction and field-effect transistors. Also the reason behind the difficulties in obtaining p-TCO materials and possible solutions are discussed in details. Considerable attention is given in describing the various patent generations on the field of p-TCO materials as well as transparent p-n junction diodes and light emitting devices. Also, most importantly, a detailed review and patenting activities on the nanocrystalline p-TCO materials and transparent nano-active device fabrication are furnished with considerable attention. And finally, a systematic description on the fabrication and characterization of nanocrystalline, p-type transparent conducting CuAlO(2) thin film, deposited by cost-effective low-temperature DC sputtering technique, by our group, is furnished in details. These p-TCO micro/nano-materials have wide range of applications in the field of optoelectronics, nanoelectronics, space sciences, field-emission displays, thermoelectric converters and sensing devices. PMID:19076042

  19. Wavelength-shifting fiber signal readout from Transparent RUbber SheeT (TRUST) type LiCaAlF6 neutron scintillator

    NASA Astrophysics Data System (ADS)

    Watanabe, Kenichi; Yamazaki, Takuya; Sugimoto, Dai; Yamazaki, Atsushi; Uritani, Akira; Iguchi, Tetsuo; Fukuda, Kentaro; Ishidu, Sumito; Yanagida, Takayuki; Fujimoto, Yutaka

    2015-06-01

    As an alternative to the standard 3He neutron detector, we are developing the Transparent RUbber SheeT type (TRUST) Eu doped LiCaAlF6 (Eu:LiCAF) scintillator. This type of neutron scintillator can easily be fabricated as a large area sheet. In order to take advantage of a large area detector, we try to readout scintillation photons using a wavelength-shifting fiber (WLSF) from a TRUST Eu:LiCAF scintillator. The TRUST Eu:LiCAF scintillator with the size of 50×50×5 mm3 was mounted on the WLSF plate and the end of the WLSFs was connected with a PMT. In order to reject high pulse height events induced in the WLSFs, we applied the pulse shape discrimination technique. The gamma-ray intrinsic and neutron absolute detection efficiency is evaluated to be 8.8×10-7 and 9×10-3 cps/ng Cf (2 m) for the TRUST Eu:LiCAF scintillator with the size of 50×50×5 mm3.

  20. Production and Characterization of Active Transparent PET Films for Oxygen Sensitive Foods Packaging

    NASA Astrophysics Data System (ADS)

    Rosaria Galdi, Maria; Incarnato, Loredana

    2010-06-01

    The aim of this work is to investigate possible solutions to realize active, transparent PET film suitable for packaging oxygen sensitive foods. At this purpose, monolayer active PET films at different oxygen scavenger concentrations and multilayer active ones were produced by cast extrusion laboratory scale equipments. To assess their activity and to verify the efficacy of such solutions, O2 absorption analyses were carried out in continuous by an innovative oxygen meter.

  1. Methods of forming aluminum oxynitride-comprising bodies, including methods of forming a sheet of transparent armor

    DOEpatents

    Chu, Henry Shiu-Hung [Idaho Falls, ID; Lillo, Thomas Martin [Idaho Falls, ID

    2008-12-02

    The invention includes methods of forming an aluminum oxynitride-comprising body. For example, a mixture is formed which comprises A:B:C in a respective molar ratio in the range of 9:3.6-6.2:0.1-1.1, where "A" is Al.sub.2O.sub.3, "B" is AlN, and "C" is a total of one or more of B.sub.2O.sub.3, SiO.sub.2, Si--Al--O--N, and TiO.sub.2. The mixture is sintered at a temperature of at least 1,600.degree. C. at a pressure of no greater than 500 psia effective to form an aluminum oxynitride-comprising body which is at least internally transparent and has at least 99% maximum theoretical density.

  2. 2D Confined-Space Assisted Growth of Molecular-Level-Thick Polypyrrole Sheets with High Conductivity and Transparency.

    PubMed

    Yang, Yang; Wang, Dong; Wu, Yongjin; Tian, Xiaorui; Qin, Haili; Hu, Liang; Zhang, Ting; Ni, Weihai; Jin, Jian

    2016-04-01

    Herein, the use of a 2D soft template system composed of hundred-nanometer-thick water/ethanol mixed layers sandwiched by lamellar bilayer membranes of a self-assembled amphiphilic molecule to produce ultrathin polyprrole (PPy) with a uniform thickness as thin as 3.8 nm and with large dimensions (>2 μm(2) ) is presented. The obtained PPy nanosheets exhibit regioregularity with ordered chain alignment where the polymer chains in the nanosheets produced are well aligned with a clear interchain spacing as confirmed by small-angle X-ray scattering measurement. The molecular-level-thick PPy nanosheets exhibit extremely high conductivity up to 1330 S m(-1) , thanks to the ordered alignment of polymer chains in the nanosheets, and a high transparency in both the visible region (transmittance >99%) and near-infrared region (transmittance >93%). PMID:26833631

  3. Field-induced activation of metal oxide semiconductor for low temperature flexible transparent electronic device applications

    NASA Astrophysics Data System (ADS)

    Pudasaini, Pushpa Raj; Noh, Joo Hyon; Wong, Anthony; Haglund, Amada; Ward, Thomas Zac; Mandrus, David; Rack, Philip

    Amorphous metal-oxide semiconductors have been extensively studied as an active channel material in thin film transistors due to their high carrier mobility, and excellent large-area uniformity. Here, we report the athermal activation of amorphous indium gallium zinc oxide semiconductor channels by an electric field-induced oxygen migration via gating through an ionic liquid. Using field-induced activation, a transparent flexible thin film transistor is demonstrated on a polyamide substrate with transistor characteristics having a current ON-OFF ratio exceeding 108, and saturation field effect mobility of 8.32 cm2/(V.s) without a post-deposition thermal treatment. This study demonstrates the potential of field-induced activation as an athermal alternative to traditional post-deposition thermal annealing for metal oxide electronic devices suitable for transparent and flexible polymer substrates. Materials Science and Technology Division, ORBL, Oak Ridge, TN 37831, USA.

  4. Self-Activated Transparent All-Graphene Gas Sensor with Endurance to Humidity and Mechanical Bending.

    PubMed

    Kim, Yeon Hoo; Kim, Sang Jin; Kim, Yong-Jin; Shim, Yeong-Seok; Kim, Soo Young; Hong, Byung Hee; Jang, Ho Won

    2015-10-27

    Graphene is considered as one of leading candidates for gas sensor applications in the Internet of Things owing to its unique properties such as high sensitivity to gas adsorption, transparency, and flexibility. We present self-activated operation of all graphene gas sensors with high transparency and flexibility. The all-graphene gas sensors which consist of graphene for both sensor electrodes and active sensing area exhibit highly sensitive, selective, and reversible responses to NO2 without external heating. The sensors show reliable operation under high humidity conditions and bending strain. In addition to these remarkable device performances, the significantly facile fabrication process enlarges the potential of the all-graphene gas sensors for use in the Internet of Things and wearable electronics. PMID:26321290

  5. Joint DOE-PNC research on the use of transparency in support of nuclear nonproliferation

    SciTech Connect

    Mochiji, Toshiro; Keeney, R.; Tazaki, Makiko; Nakhleh, C.; Puckett, J.; Stanbro, W.

    1999-01-01

    PNC and LANL collaborated in research on the concept of transparency in nuclear nonproliferation. The research was based on the Action Sheet No. 21, which was signed in February 1996, ``The Joint Research on Transparency in Nuclear Nonproliferation`` under the ``Agreement between the Power Reactor and Nuclear Fuel Development Corporation of Japan (PNC) and the US Department of Energy (DOE) for Cooperation in Research and Development Concerning Nuclear Material Control and Accounting Measures for Safeguards and Nonproliferation``. The purpose of Action Sheet 21 is to provide a fundamental study on Transparency to clarify the means to improve worldwide acceptability for the nuclear energy from the nuclear nonproliferation point of view. This project consists of independent research and then joint discussion at workshops that address a series of topics and issues in transparency. The activities covered in Action Sheet 21 took place over a period of 18 months. Three workshops were held; the first and the third hosted by PNC in Tokyo, Japan and the second hosted by LANL in Los Alamos, New Mexico, US. The following is a summary of the three workshops. The first workshop addressed the policy environment of transparency. Each side presented its perspective on the following issues: (1) a definition of transparency, (2) reasons for transparency, (3) detailed goals of transparency and (4) obstacles to transparency. The topic of the second workshop was ``Development of Transparency Options.`` The activities accomplished were (1) identify type of facilities where transparency might be applied, (2) define criteria for applying transparency, and (3) delineate applicable transparency options. The goal of the third workshop, ``Technical Options for Transparency,`` was to (1) identify conceptual options for transparency system design; (2) identify instrumentation, measurement, data collection and data processing options; (3) identify data display options; and (4) identify technical

  6. Virus activity on the surface of glaciers and ice sheets

    NASA Astrophysics Data System (ADS)

    Bellas, C. M.; Anesio, A. M.; Telling, J.; Stibal, M.; Barker, G.; Tranter, M.; Yallop, M.; Cook, J.

    2012-12-01

    Viruses are found wherever there is life. They are major components of aquatic ecosystems and through interactions with their hosts they significantly alter global biogeochemical cycles and drive evolutionary processes. Here we focus on the interactions between bacteriophages and their hosts inhabiting the microbially dominated supraglacial ecosystems known as cryoconite holes. The diversity of phages present in the sediments of cryoconites was examined for the first time by using a molecular based approach to target the T4-type bacteriophage. Through phylogenetic analysis it was determined that the phage community was diverse, consisting of strains that grouped with those from other global habitats and those that formed several completely new T4-type phage clusters. The activity of the viral community present on glaciers from Svalbard and the Greenland Ice Sheet was also addressed through a series of incubation experiments. Here new virus production was found to be capable of turning over the viral population approximately twice a day, a rate comparable to marine and freshwater sediments around the globe. This large scale viral production was found to be theoretically capable of accounting for all heterotrophic bacterial mortality in cryoconite holes. The mode of infection that viruses employ in cryoconite holes was also addressed to show that a variety of viral life strategies are likely responsible for the continued dominance of viruses in these unique habitats. The implications of viral activity are discussed in terms of carbon cycling in supraglacial ecosystems.

  7. Self-activated ultrahigh chemosensitivity of oxide thin film nanostructures for transparent sensors.

    PubMed

    Moon, Hi Gyu; Shim, Young-Soek; Kim, Do Hong; Jeong, Hu Young; Jeong, Myoungho; Jung, Joo Young; Han, Seung Min; Kim, Jong Kyu; Kim, Jin-Sang; Park, Hyung-Ho; Lee, Jong-Heun; Tuller, Harry L; Yoon, Seok-Jin; Jang, Ho Won

    2012-01-01

    One of the top design priorities for semiconductor chemical sensors is developing simple, low-cost, sensitive and reliable sensors to be built in handheld devices. However, the need to implement heating elements in sensor devices, and the resulting high power consumption, remains a major obstacle for the realization of miniaturized and integrated chemoresistive thin film sensors based on metal oxides. Here we demonstrate structurally simple but extremely efficient all oxide chemoresistive sensors with ~90% transmittance at visible wavelengths. Highly effective self-activation in anisotropically self-assembled nanocolumnar tungsten oxide thin films on glass substrate with indium-tin oxide electrodes enables ultrahigh response to nitrogen dioxide and volatile organic compounds with detection limits down to parts per trillion levels and power consumption less than 0.2 microwatts. Beyond the sensing performance, high transparency at visible wavelengths creates opportunities for their use in transparent electronic circuitry and optoelectronic devices with avenues for further functional convergence. PMID:22905319

  8. Self-activated ultrahigh chemosensitivity of oxide thin film nanostructures for transparent sensors

    PubMed Central

    Moon, Hi Gyu; Shim, Young-Soek; Kim, Do Hong; Jeong, Hu Young; Jeong, Myoungho; Jung, Joo Young; Han, Seung Min; Kim, Jong Kyu; Kim, Jin-Sang; Park, Hyung-Ho; Lee, Jong-Heun; Tuller, Harry L.; Yoon, Seok-Jin; Jang, Ho Won

    2012-01-01

    One of the top design priorities for semiconductor chemical sensors is developing simple, low-cost, sensitive and reliable sensors to be built in handheld devices. However, the need to implement heating elements in sensor devices, and the resulting high power consumption, remains a major obstacle for the realization of miniaturized and integrated chemoresistive thin film sensors based on metal oxides. Here we demonstrate structurally simple but extremely efficient all oxide chemoresistive sensors with ~90% transmittance at visible wavelengths. Highly effective self-activation in anisotropically self-assembled nanocolumnar tungsten oxide thin films on glass substrate with indium-tin oxide electrodes enables ultrahigh response to nitrogen dioxide and volatile organic compounds with detection limits down to parts per trillion levels and power consumption less than 0.2 microwatts. Beyond the sensing performance, high transparency at visible wavelengths creates opportunities for their use in transparent electronic circuitry and optoelectronic devices with avenues for further functional convergence. PMID:22905319

  9. Transparent Stretchable Self-Powered Patchable Sensor Platform with Ultrasensitive Recognition of Human Activities.

    PubMed

    Hwang, Byeong-Ung; Lee, Ju-Hyuck; Trung, Tran Quang; Roh, Eun; Kim, Do-Il; Kim, Sang-Woo; Lee, Nae-Eung

    2015-09-22

    Monitoring of human activities can provide clinically relevant information pertaining to disease diagnostics, preventive medicine, care for patients with chronic diseases, rehabilitation, and prosthetics. The recognition of strains on human skin, induced by subtle movements of muscles in the internal organs, such as the esophagus and trachea, and the motion of joints, was demonstrated using a self-powered patchable strain sensor platform, composed on multifunctional nanocomposites of low-density silver nanowires with a conductive elastomer of poly(3,4-ethylenedioxythiophene):polystyrenesulfonate/polyurethane, with high sensitivity, stretchability, and optical transparency. The ultra-low-power consumption of the sensor, integrated with both a supercapacitor and a triboelectric nanogenerator into a single transparent stretchable platform based on the same nanocomposites, results in a self-powered monitoring system for skin strain. The capability of the sensor to recognize a wide range of strain on skin has the potential for use in new areas of invisible stretchable electronics for human monitoring. A new type of transparent, stretchable, and ultrasensitive strain sensor based on a AgNW/PEDOT:PSS/PU nanocomposite was developed. The concept of a self-powered patchable sensor system integrated with a supercapacitor and a triboelectric nanogenerator that can be used universally as an autonomous invisible sensor system was used to detect the wide range of strain on human skin. PMID:26277994

  10. Transparent selective illumination means suitable for use in optically activated electrical switches and optically activated electrical switches constructed using same

    DOEpatents

    Wilcox, R.B.

    1991-09-10

    A planar transparent light conducting means and an improved optically activated electrical switch made using the novel light conducting means are disclosed. The light conducting means further comprise light scattering means on one or more opposite planar surfaces thereof to transmit light from the light conducting means into adjacent media and reflective means on other surfaces of the light conducting means not containing the light scattering means. The optically activated electrical switch comprises at least two stacked photoconductive wafers, each having electrodes formed on both surfaces thereof, and separated by the planar transparent light conducting means. The light scattering means on the light conducting means face surfaces of the wafers not covered by the electrodes to transmit light from the light conducting means into the photoconductive wafers to uniformly illuminate and activate the switch. 11 figures.

  11. Transparent selective illumination means suitable for use in optically activated electrical switches and optically activated electrical switches constructed using same

    DOEpatents

    Wilcox, Russell B.

    1991-01-01

    A planar transparent light conducting means and an improved optically activated electrical switch made using the novel light conducting means are disclosed. The light conducting means further comprise light scattering means on one or more opposite planar surfaces thereof to transmit light from the light conducting means into adjacent media and reflective means on other surfaces of the light conducting means not containing the light scattering means. The optically activated electrical switch comprises at least two stacked photoconductive wafers, each having electrodes formed on both surfaces thereof, and separated by the planar transparent light conducting means. The light scattering means on the light conducting means face surfaces of the wafers not covered by the electrodes to transmit light from the light conducting means into the photoconductive wafers to uniformly illuminate and activate the switch.

  12. Transparent electronics and prospects for transparent displays

    NASA Astrophysics Data System (ADS)

    Wager, John F.; Valencia, Melinda M.; Bender, Jeffrey P.; Norris, Benjamin J.; Chiang, Hai Q.; Hong, David; Norris, Luke N.; Harman, Taran V.; Park, Sangmoon; Anderson, Jeremy T.; Park, Cheol-Hee; Keszler, Douglas A.; Tate, Janet; Yanagi, Hiroshi; Price, Matthew F.; Hoffman, R. L.

    2003-09-01

    Transparent electronics is a nascent technology whose objective is the realization of invisible electronic circuits. Part of the impetus for the development of transparent electronics is the recent availability of p-type transparent conductive oxides (TCOs). With the emergence of p-type TCOs, in addition to conventional n-type TCOs such as indium-tin oxide, tin oxide, and zinc oxide, fabrication of transparent bipolar electronic devices becomes feasible. The first part of this paper reviews TCOs and discusses our work in the development of p-TCOs and alternative TC materials (e.g. sulfides). We have recently invented a novel, n-channel, accumulation-mode transparent thin-film transistor (TTFT). This TTFT is highly transparent, has very little light sensitivity, and exhibits electrical characteristics that appear to be suitable for implementation as a transparent select-transistor in each pixel of an active-matrix liquid-crystal display (AMLCD). Moreover, the processing technology used to fabricate this device is relatively simple and appears to be compatible with inexpensive glass substrate technology. The second part of this paper focuses on TTFTs. If transparent electronics is employed to realize transparent back-plane electronic drivers on transparent substrates, fabrication of a transparent display becomes feasible. The third part of this paper offers an approach for realization of a transparent display.

  13. Ionic Liquid Activation of Amorphous Metal-Oxide Semiconductors for Flexible Transparent Electronic Devices

    DOE PAGESBeta

    Pudasaini, Pushpa Raj; Noh, Joo Hyon; Wong, Anthony T.; Ovchinnikova, Olga S.; Haglund, Amanda V.; Dai, Sheng; Ward, Thomas Zac; Mandrus, David; Rack, Philip D.

    2016-02-09

    To begin this abstract, amorphous metal-oxide semiconductors offer the high carrier mobilities and excellent large-area uniformity required for high performance, transparent, flexible electronic devices; however, a critical bottleneck to their widespread implementation is the need to activate these materials at high temperatures which are not compatible with flexible polymer substrates. The highly controllable activation of amorphous indium gallium zinc oxide semiconductor channels using ionic liquid gating at room temperature is reported. Activation is controlled by electric field-induced oxygen migration across the ionic liquid-semiconductor interface. In addition to activation of unannealed devices, it is shown that threshold voltages of a transistormore » can be linearly tuned between the enhancement and depletion modes. Finally, the first ever example of transparent flexible thin film metal oxide transistor on a polyamide substrate created using this simple technique is demonstrated. Finally, this study demonstrates the potential of field-induced activation as a promising alternative to traditional postdeposition thermal annealing which opens the door to wide scale implementation into flexible electronic applications.« less

  14. Transparent conductive indium oxide film deposited on low temperature substrates by activated reactive evaporation.

    PubMed

    Marcovitch, O; Klein, Z; Lubezky, I

    1989-07-15

    High quality conductive coatings for the visible region were prepared on low temperature glass substrates. The conductive layer was an indium oxide film deposited by the activated reactive evaporation technique using a glow discharge hollow cathode ion gun. An antireflective layer of MgF(2) was deposited over the conductive layer. The average transmission in the visible region of the coated glass with sheet resistance of < 15 Omega/sq was greater than 90%. The coating was durable and passed a series of environmental tests according to MIL-C-675C. PMID:20555600

  15. All about Me: Reproducible Activity Sheets To Develop Self-Esteem in Your Students.

    ERIC Educational Resources Information Center

    Palomares, Susanna

    This document contains a set of reproducible activity sheets for teachers to use in enhancing the self-esteem of their students. Designed to supplement other approaches being used by teachers, the activities in this book can be used to infuse esteem-building activities into the core curriculum. The activities are organized around several…

  16. Transparent gels: study of their formation and assimilation of active ingredients through phase diagrams.

    PubMed

    Comelles, F; Caelles, J; Parra, J L; Leal, J S

    1992-08-01

    Synopsis Multicomponent gel formulations capable of assimilating, simultaneously, several active ingredients of potential application in the cosmetic field were studied. The possibility of formation of a transparent gel was determined using a method which consisted in the optimization of several lipophilic basic compositions, composed of oil, a mixture of surfactants, a sunscreen agent, several vitamins and antioxidants situated in the base of a regular tetrahedron that symbolized the considered system. To this, a polar phase made of water, a cosolvent and urea in appropriate proportions and situated in the fourth vertex, was progressively added. It may be concluded, that the use of phase diagrams on cosmetic systems, constitutes a useful way to select the components and their mutual ratios, allowing an adaptation to the specific requested conditions of formulation. PMID:19272106

  17. Plasmon-induced transparency in metamaterials: Active near field coupling between bright superconducting and dark metallic mode resonators

    NASA Astrophysics Data System (ADS)

    Cao, Wei; Singh, Ranjan; Zhang, Caihong; Han, Jiaguang; Tonouchi, Masayoshi; Zhang, Weili

    2013-09-01

    Structured plasmonic metamaterial devices offer the design flexibility to be size scaled for operation across the electromagnetic spectrum and are extremely attractive for generating electromagnetically induced transparency and slow-light behaviors via coupling of bright and dark subwavelength resonators. Here, we experimentally demonstrate a thermally active superconductor-metal coupled resonator based hybrid terahertz metamaterial on a sapphire substrate that shows tunable transparency and slow light behavior as the metamaterial chip is cooled below the high-temperature superconducting phase transition temperature. This hybrid metamaterial opens up the avenues for designing micro-sized active circuitry with switching, modulation, and "slowing down terahertz light" capabilities.

  18. Transparent ambipolar organic thin film transistors based on multilayer transparent source-drain electrodes

    NASA Astrophysics Data System (ADS)

    Zhang, Nan; Hu, Yongsheng; Lin, Jie; Li, Yantao; Liu, Xingyuan

    2016-08-01

    A fabrication method for transparent ambipolar organic thin film transistors with transparent Sb2O3/Ag/Sb2O3 (SAS) source and drain electrodes has been developed. A pentacene/N,N'-ditridecylperylene-3,4,9,10-tetracarboxylic di-imide (PTCDI-C13) bilayer heterojunction is used as the active semiconductor. The electrodes are deposited by room temperature electron beam evaporation. The devices are fabricated without damaging the active layers. The SAS electrodes have high transmittance (82.5%) and low sheet resistance (8 Ω/sq). High performance devices with hole and electron mobilities of 0.3 cm2/V s and 0.027 cm2/V s, respectively, and average visible range transmittance of 72% were obtained. These transistors have potential for transparent logic integrated circuit applications.

  19. Active Adoption of Void Formation in Metal-Oxide for All Transparent Super-Performing Photodetectors

    PubMed Central

    Patel, Malkeshkumar; Kim, Hong-Sik; Park, Hyeong-Ho; Kim, Joondong

    2016-01-01

    Could ‘defect-considered’ void formation in metal-oxide be actively used? Is it possible to realize stable void formation in a metal-oxide layer, beyond unexpected observations, for functional utilization? Herein we demonstrate the effective tailoring of void formation of NiO for ultra-sensitive UV photodetection. NiO was formed onto pre-sputtered ZnO for a large size and spontaneously formed abrupt p-NiO/n-ZnO heterojunction device. To form voids at an interface, rapid thermal process was performed, resulting in highly visible light transparency (85–95%). This heterojunction provides extremely low saturation current (<0.1 nA) with an extraordinary rectifying ratio value of over 3000 and works well without any additional metal electrodes. Under UV illumination, we can observe the fast photoresponse time (10 ms) along with the highest possible responsivity (1.8 A W−1) and excellent detectivity (2 × 1013 Jones) due to the existence of an intrinsic-void layer at the interface. We consider this as the first report on metal-oxide-based void formation (Kirkendall effect) for effective photoelectric device applications. We propose that the active adoption of ‘defect-considered’ Kirkendall-voids will open up a new era for metal-oxide based photoelectric devices. PMID:27151288

  20. Active Adoption of Void Formation in Metal-Oxide for All Transparent Super-Performing Photodetectors

    NASA Astrophysics Data System (ADS)

    Patel, Malkeshkumar; Kim, Hong-Sik; Park, Hyeong-Ho; Kim, Joondong

    2016-05-01

    Could ‘defect-considered’ void formation in metal-oxide be actively used? Is it possible to realize stable void formation in a metal-oxide layer, beyond unexpected observations, for functional utilization? Herein we demonstrate the effective tailoring of void formation of NiO for ultra-sensitive UV photodetection. NiO was formed onto pre-sputtered ZnO for a large size and spontaneously formed abrupt p-NiO/n-ZnO heterojunction device. To form voids at an interface, rapid thermal process was performed, resulting in highly visible light transparency (85–95%). This heterojunction provides extremely low saturation current (<0.1 nA) with an extraordinary rectifying ratio value of over 3000 and works well without any additional metal electrodes. Under UV illumination, we can observe the fast photoresponse time (10 ms) along with the highest possible responsivity (1.8 A W‑1) and excellent detectivity (2 × 1013 Jones) due to the existence of an intrinsic-void layer at the interface. We consider this as the first report on metal-oxide-based void formation (Kirkendall effect) for effective photoelectric device applications. We propose that the active adoption of ‘defect-considered’ Kirkendall-voids will open up a new era for metal-oxide based photoelectric devices.

  1. Active Adoption of Void Formation in Metal-Oxide for All Transparent Super-Performing Photodetectors.

    PubMed

    Patel, Malkeshkumar; Kim, Hong-Sik; Park, Hyeong-Ho; Kim, Joondong

    2016-01-01

    Could 'defect-considered' void formation in metal-oxide be actively used? Is it possible to realize stable void formation in a metal-oxide layer, beyond unexpected observations, for functional utilization? Herein we demonstrate the effective tailoring of void formation of NiO for ultra-sensitive UV photodetection. NiO was formed onto pre-sputtered ZnO for a large size and spontaneously formed abrupt p-NiO/n-ZnO heterojunction device. To form voids at an interface, rapid thermal process was performed, resulting in highly visible light transparency (85-95%). This heterojunction provides extremely low saturation current (<0.1 nA) with an extraordinary rectifying ratio value of over 3000 and works well without any additional metal electrodes. Under UV illumination, we can observe the fast photoresponse time (10 ms) along with the highest possible responsivity (1.8 A W(-1)) and excellent detectivity (2 × 10(13) Jones) due to the existence of an intrinsic-void layer at the interface. We consider this as the first report on metal-oxide-based void formation (Kirkendall effect) for effective photoelectric device applications. We propose that the active adoption of 'defect-considered' Kirkendall-voids will open up a new era for metal-oxide based photoelectric devices. PMID:27151288

  2. Litter Control Achievement - Ohio 4-H Club Score Sheet [and] Activity Guides 1 through 7. 4-H Pilot Program 918.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. Cooperative Extension Service.

    Seven activity guides, evaluation sheet, and club scoresheet have been prepared for Ohio 4-H clubs' litter education program. Topics of the seven activity guides include: (1) general guidelines and types of activities; (2) little known facts about waste/litter; (3) guidelines for a walking tour; (4) fact sheet (questionnaire) related to garbage;…

  3. Atomically-thin two-dimensional sheets for understanding active sites in catalysis.

    PubMed

    Sun, Yongfu; Gao, Shan; Lei, Fengcai; Xie, Yi

    2015-02-01

    Catalysis can speed up chemical reactions and it usually occurs on the low coordinated steps, edges, terraces, kinks and corner atoms that are often called "active sites". However, the atomic level interplay between active sites and catalytic activity is still an open question, owing to the large difference between idealized models and real catalysts. This stimulates us to pursue a suitable material model for studying the active sites-catalytic activity relationship, in which the atomically-thin two-dimensional sheets could serve as an ideal model, owing to their relatively simple type of active site and the ultrahigh fraction of active sites that are comparable to the overall atoms. In this tutorial review, we focus on the recent progress in disclosing the factors that affect the activity of reactive sites, including characterization of atomic coordination number, structural defects and disorder in ultrathin two-dimensional sheets by X-ray absorption fine structure spectroscopy, positron annihilation spectroscopy, electron spin resonance and high resolution transmission electron microscopy. Also, we overview their applications in CO catalytic oxidation, photocatalytic water splitting, electrocatalytic oxygen and hydrogen evolution reactions, and hence highlight the atomic level interplay among coordination number, structural defects/disorder, active sites and catalytic activity in the two-dimensional sheets with atomic thickness. Finally, we also present the major challenges and opportunities regarding the role of active sites in catalysis. We believe that this review provides critical insights for understanding the catalysis and hence helps to develop new catalysts with high catalytic activity. PMID:25382246

  4. "Working." Student Activity Sheets for Selected Interviews Contained in "Working" by Studs Terkel.

    ERIC Educational Resources Information Center

    Eakin, David; And Others

    These student activity sheets are intended to accompany a vocational English program based on Studs Terkel's book, "Working," a collection of more than 100 interviews with people about their jobs. The 30 interviews selected for inclusion in the curriculum either illustrate occupations taught in the schools or deal with occupations related to those…

  5. NREL Develops Accelerated Sample Activation Process for Hydrogen Storage Materials (Fact Sheet)

    SciTech Connect

    Not Available

    2010-12-01

    This fact sheet describes NREL's accomplishments in developing a new sample activation process that reduces the time to prepare samples for measurement of hydrogen storage from several days to five minutes and provides more uniform samples. Work was performed by NREL's Chemical and Materials Science Center.

  6. Teen Sexual Activity, Pregnancy and Childbearing among Latinos in the United States. Fact Sheet.

    ERIC Educational Resources Information Center

    National Campaign To Prevent Teen Pregnancy, Washington, DC.

    The Latino population is the fastest-growing major racial/ethnic group in the United States. By 2020, approximately 16 percent of the population will be Latino. This increase will be even more pronounced among teens. This fact sheet summarizes data from the National Vital Statistics Reports on reported sexual activity, pregnancy rates, and…

  7. Are Adolescents Talking with Their Parents about Sex before Becoming Sexually Active? Fact Sheet

    ERIC Educational Resources Information Center

    Leuschner, Kristin

    2010-01-01

    This paper examines parent-child discussions of sexual behavior. It finds consistency in the timing and content of such discussions; however, many parents and children do not discuss key topics, such as birth control, before adolescents become sexually active. [This fact sheet is based on Megan K. Beckett, Marc N. Elliott, Steven Martino, David E.…

  8. An Investigation of the Use of Student Activity Sheets; Employer-Based Career Education. Technical Report No. 44.

    ERIC Educational Resources Information Center

    Seyfarth, John T.; And Others

    The report examines the use of student activity sheets in evaluating the performance of students in the Appalachia Educational Laboratory's Employer-Based Career Education (AEL/EBCE) program. All activity sheets completed during the second semester of 1972-73 for selected participants in the following subject areas were examined and are analyzed…

  9. Effect of transparent film desiccant on the lifetime of top-emitting active matrix organic light emitting diodes

    NASA Astrophysics Data System (ADS)

    Lee, Byoung Duk; Cho, Yoon-Hyung; Kim, Won-Jong; Oh, Min Ho; Lee, Jong Hyuk; Zang, Dong Sik

    2007-03-01

    The effects of a transparent film desiccant on the lifetime of top-emitting active matrix organic light emitting diodes (AMOLEDs) were investigated. The transparent film desiccants were prepared by mixing solutions dispersed with calcium oxide powders and ultraviolet-curable resins. As the solid content in the solutions increased from 15to30wt%, the average particle size increased from 107to240nm, whereas the transmittance of the films decreased from 98% to 80% in the visible range. The devices encapsulated with the transparent film desiccants which contained 20wt% CaO exhibited no dark spots and 97% of the initial luminance, even after being stored for over 500h at 70°C and 90% relative humidity. Also, the operational lifetime of these devices was 1850h, ten times longer than that of a device without desiccant. These results confirmed that the transparent film desiccants, which absorbed the moisture that penetrated into the devices, could be applied to the encapsulation of top-emitting AMOLEDs.

  10. Fe, O, and C Charge States Associated with Quiescent Versus Active Current Sheets in the Solar Wind

    NASA Technical Reports Server (NTRS)

    Suess, S. T.; Ko, Y.-K.; vonSteiger, R.

    2008-01-01

    Ulysses MAG data were used to locate the heliospheric current sheet in data from 1991 through 2006. The purpose was to characterize typical charge states for Fe, O, and C in the vicinity of the current sheet and provide insight into the physical sources for these charge states in the corona. A study of He/H around the current sheets has led to a clear distinction between quiescent current sheets at times of low solar activity and active current sheets associated with magnetic clouds (and, presumably, ICMES). It has been shown that high ionization state Fe is produced in the corona in current sheets associated with CMEs through spectroscopic observations of the corona and through in situ detection at Ulysses. Here we show that the ionization state of Fe is typically only enhanced around active current sheets while the ionization states of O and C are commonly enhanced around both quiescent and active current sheets. This is consistent with UV coronal spectroscopy, which has shown that reconnection in current sheets behind CMEs leads to high temperatures not typically seen above quiet streamers.

  11. World War II Commemoration Committee: Fact Sheet and Suggested Activities.

    ERIC Educational Resources Information Center

    Department of Defense, Washington, DC.

    This packet suggests activities and events that school districts, schools, classes, and educational organizations can conduct to commemorate World War II. Suggestions are made to include local veterans, including those in veteran's and nursing homes and hospitals, and youth at every possible opportunity. Recognition can take the form of military…

  12. Analysis of methanogenic and methanotrophic activity at the western margin of the Greenland Ice Sheet

    NASA Astrophysics Data System (ADS)

    Broemsen, E. L.; Webster, K. D.; Dieser, M.; Pratt, L. M.; Christner, B. C.

    2012-12-01

    Anoxic conditions in environments beneath the world's glaciers and ice sheets provide plausible habitats supporting the microbial production of methane. Recent reports of potential methane sources beneath the Greenland Ice Sheet (GrIS) suggest in situ production by an active community of methanogens. Beneath the GrIS, microbially derived methane can be dissolved in subglacial water, and during periods of melting, can exchange with the atmosphere at sites of subglacial discharge. Transfer of methane from subglacial fluids to the atmosphere could be a significant climate factor, but few data are available to make such assessments. The specific aim of this study was to characterize the composition and activity of methanogens and methanotrophs present in samples of subglacial outflow at the ice sheet margin near Kangerlussuaq, Greenland. Subglaical water was collected twice-weekly over a nine week period (mid July to mid September of 2012) and the dissolved methane concentration in the samples was determined via gas chromatography. Extracted RNA and DNA from the subglacial water was analyzed by analysis of 16s rRNA and rRNA genes present in the subglacial assemblages. From the molecular results we infer the presence of active methanogens related to the order Methanosarcinales. Further, locally elevated concentrations of atmospheric methane as high as 1.92 ± 0.03 ppmv, were detected in the ice tunnel of the subglacial outflow using open-path laser spectrometry. From these data we estimate rates of methane release at the ice sheet margin during the summer melt months at this geographical location. The results provide a context for addressing the impact that deglaciation will have on the release of greenhouse gases from ice sheets on a warming Earth.

  13. Antibacterial activity of two-dimensional MoS2 sheets

    NASA Astrophysics Data System (ADS)

    Yang, Xi; Li, Jie; Liang, Tao; Ma, Chunyan; Zhang, Yingying; Chen, Hongzheng; Hanagata, Nobutaka; Su, Huanxing; Xu, Mingsheng

    2014-08-01

    Graphene-like two-dimensional materials (2DMats) show application potential in optoelectronics and biomedicine due to their unique properties. However, environmental and biological influences of these 2DMats remain to be unveiled. Here we reported the antibacterial activity of two-dimensional (2D) chemically exfoliated MoS2 (ce-MoS2) sheets. We found that the antibacterial activity of ce-MoS2 sheets was much more potent than that of the raw MoS2 powders used for the synthesis of ce-MoS2 sheets possibly due to the 2D planar structure (high specific surface area) and higher conductivity of the ce-MoS2. We investigated the antibacterial mechanisms of the ce-MoS2 sheets and proposed their antibacterial pathways. We found that the ce-MoS2 sheets could produce reactive oxygen species (ROS), different from a previous report on graphene-based materials. Particularly, the oxidation capacity of the ce-MoS2 sheets toward glutathione oxidation showed a time and concentration dependent trend, which is fully consistent with the antibacterial behaviour of the ce-MoS2 sheets. The results suggest that antimicrobial behaviors were attributable to both membrane and oxidation stress. The antibacterial pathways include MoS2-bacteria contact induced membrane stress, superoxide anion (O2&z.rad;-) induced ROS production by the ce-MoS2, and the ensuing superoxide anion-independent oxidation. Our study thus indicates that the tailoring of the dimension of nanomaterials and their electronic properties would manipulate antibacterial activity.Graphene-like two-dimensional materials (2DMats) show application potential in optoelectronics and biomedicine due to their unique properties. However, environmental and biological influences of these 2DMats remain to be unveiled. Here we reported the antibacterial activity of two-dimensional (2D) chemically exfoliated MoS2 (ce-MoS2) sheets. We found that the antibacterial activity of ce-MoS2 sheets was much more potent than that of the raw MoS2 powders

  14. Transparent conductors composed of nanomaterials.

    PubMed

    Layani, Michael; Kamyshny, Alexander; Magdassi, Shlomo

    2014-06-01

    This is a review on recent developments in the field of transparent conductive coatings (TCCs) for ITO replacement. The review describes the basic properties of conductive nanomaterials suitable for fabrication of such TCCs (metallic nanoparticles and nanowires, carbon nanotubes and graphene sheets), various methods of patterning the metal nanoparticles with formation of conductive transparent metallic grids, honeycomb structures and 2D arrays of interconnected rings as well as fabrication of TCCs based on graphene and carbon nanotubes. Applications of TCCs in electronic and optoelectronic devices, such as solar cells, electroluminescent and electrochromic devices, touch screens and displays, and transparent EMI shielders, are discussed. PMID:24777332

  15. Process for forming transparent aerogel insulating arrays

    DOEpatents

    Tewari, Param H.; Hunt, Arlon J.

    1986-01-01

    An improved supercritical drying process for forming transparent silica aerogel arrays is described. The process is of the type utilizing the steps of hydrolyzing and condensing aloxides to form alcogels. A subsequent step removes the alcohol to form aerogels. The improvement includes the additional step, after alcogels are formed, of substituting a solvent, such as CO.sub.2, for the alcohol in the alcogels, the solvent having a critical temperature less than the critical temperature of the alcohol. The resulting gels are dried at a supercritical temperature for the selected solvent, such as CO.sub.2, to thereby provide a transparent aerogel array within a substantially reduced (days-to-hours) time period. The supercritical drying occurs at about 40.degree. C. instead of at about 270.degree. C. The improved process provides increased yields of large scale, structurally sound arrays. The transparent aerogel array, formed in sheets or slabs, as made in accordance with the improved process, can replace the air gap within a double glazed window, for example, to provide a substantial reduction in heat transfer. The thus formed transparent aerogel arrays may also be utilized, for example, in windows of refrigerators and ovens, or in the walls and doors thereof or as the active material in detectors for analyzing high energy elementry particles or cosmic rays.

  16. Process for forming transparent aerogel insulating arrays

    DOEpatents

    Tewari, P.H.; Hunt, A.J.

    1985-09-04

    An improved supercritical drying process for forming transparent silica aerogel arrays is described. The process is of the type utilizing the steps of hydrolyzing and condensing aloxides to form alcogels. A subsequent step removes the alcohol to form aerogels. The improvement includes the additional step, after alcogels are formed, of substituting a solvent, such as CO/sub 2/, for the alcohol in the alcogels, the solvent having a critical temperature less than the critical temperature of the alcohol. The resulting gels are dried at a supercritical temperature for the selected solvent, such as CO/sub 2/, to thereby provide a transparent aerogel array within a substantially reduced (days-to-hours) time period. The supercritical drying occurs at about 40/sup 0/C instead of at about 270/sup 0/C. The improved process provides increased yields of large scale, structurally sound arrays. The transparent aerogel array, formed in sheets or slabs, as made in accordance with the improved process, can replace the air gap within a double glazed window, for example, to provide a substantial reduction in heat transfer. The thus formed transparent aerogel arrays may also be utilized, for example, in windows of refrigerators and ovens, or in the walls and doors thereof or as the active material in detectors for analyzing high energy elementary particles or cosmic rays.

  17. Fully transparent organic transistors with junction-free metallic network electrodes

    SciTech Connect

    Pei, Ke; Wang, Zongrong; Ren, Xiaochen; Zhang, Zhichao; Peng, Boyu; Chan, Paddy K. L.

    2015-07-20

    We utilize highly transparent, junction-free metal network electrodes to fabricate fully transparent organic field effect transistors (OFETs). The patterned transparent Ag networks are developed by polymer crack template with adjustable line width and density. Sheet resistance of the network is 6.8 Ω/sq and optical transparency in the whole visible range is higher than 80%. The bottom contact OFETs with DNTT active layer and parylene-C dielectric insulator show a maximum field-effect mobility of 0.13 cm{sup 2}/V s (average mobility is 0.12 cm{sup 2}/V s) and on/off ratio is higher than 10{sup 7}. The current OFETs show great potential for applications in the next generation of transparent and flexible electronics.

  18. Potential application of mono/bi-layer molybdenum disulfide (MoS2) sheet as an efficient transparent conducting electrode in silicon heterojunction solar cells

    NASA Astrophysics Data System (ADS)

    Chaudhary, Rimjhim; Patel, Kamlesh; Sinha, Ravindra K.; Kumar, Sanjeev; Tyagi, Pawan K.

    2016-07-01

    In this paper, we have simulated the structure of n-type MoS2/silicon heterojunction solar cell and studied its function under different conditions. The optimization of parameters of the cell's layer has been carried out by using AFORS-HET software. In the present study, MoS2 has been considered as 3-D in nature instead of the reported 2-D nature. In order to ensure the formation of Schottky junction, electric contact has been made along the c-axis to collect the minority charge carriers. After optimizing the various parameters of n-type single layer MoS2, power efficiency of 12.44% has been achieved at the room temperature, which has further decreased to 9.042% as the layer number has increased up to 40. Furthermore, after optimizing the parameters of silicon wafer maximum efficiency of 16.4% has been achieved. Temperature dependence of the cell performance has also been studied and the maximum efficiency has been achieved at 300 K. In the present study, we have demonstrated that n-type ultrathin layer of MoS2 can be used as an excellent transparent conducting electrode.

  19. Active current sheets and hot flow anomalies in Mercury's bow shock

    NASA Astrophysics Data System (ADS)

    Uritsky, V. M.; Slavin, J. A.; Boardsen, S. A.; Sundberg, T.; Raines, J. M.; Anderson, B. J.; Korth, H.

    2012-12-01

    Hot flow anomalies (HFAs) represent a subset of heliospheric current sheets interacting with planetary bow shocks. They are typically formed when the normal component of the motional (convective) electric field is directed toward the embedded current sheet on at least one side. The core region of an HFA contains hot and highly deflected ion flows and rather low and turbulent magnetic field. In this talk, we report the first observations of HFA-like events at Mercury. Using the data from the orbital phase of the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission, we identify a representative ensemble of active current sheets magnetically connected to Mercury's bow shock. We show that some of these events exhibit unambiguous signatures of HFAs similar to those observed at other planets, and present their key physical characteristics. Our analysis suggests that Mercury's bow shock does not only mediate the flow of supersonic solar wind plasma but also provides conditions for local particle acceleration and heating as predicted by previous numerical simulations. Together with earlier studies of HFA activity at Earth, Venus, and Saturn, our results confirm that hot flow anomalies could be a common property of planetary bow shocks.

  20. Visibly Transparent Heaters.

    PubMed

    Gupta, Ritu; Rao, K D M; Kiruthika, S; Kulkarni, Giridhar U

    2016-05-25

    Heater plates or sheets that are visibly transparent have many interesting applications in optoelectronic devices such as displays, as well as in defrosting, defogging, gas sensing and point-of-care disposable devices. In recent years, there have been many advances in this area with the advent of next generation transparent conducting electrodes (TCE) based on a wide range of materials such as oxide nanoparticles, CNTs, graphene, metal nanowires, metal meshes and their hybrids. The challenge has been to obtain uniform and stable temperature distribution over large areas, fast heating and cooling rates at low enough input power yet not sacrificing the visible transmittance. This review provides topical coverage of this important research field paying due attention to all the issues mentioned above. PMID:27176472

  1. Transparent switchboard

    NASA Technical Reports Server (NTRS)

    Rasmussen, H. P. (Inventor)

    1973-01-01

    A tin oxide coating is formed on a plate of glass and the coating is then etched away from the glass in thin lines to form separate electrical conductors which extend to one end of the plate and connect to either a vertical (column) or horizontal (row) position sensing SCR circuit. A thin transparent insulating coating is formed over the oxide layer except at selected touch points which are positioned in a matrix pattern of vertical columns and horizontal rows. Touching one of these points with a finger bridges the thin line between adjacent conductors to activate trigger circuits in the particular row and column sensing circuits associated with the point touched. The row and column sensing circuits are similar and are powered with a low frequency, ac voltage source. The source for the row circuits is 180 out of phase with the source for the column circuits so that one circuit acts as ground for the other during half of the supply voltage cycle. The signals from the sensing circuits are input to a logic circuit which determines the presence of a valid touch, stores a binary matrix number associated with the touched point, signals a computer of the presence of a stored number and prevents storage of a new number before receiving an enable signal from the computer.

  2. Transparent evacuated insulation

    SciTech Connect

    Collins, R.E.; Fischer-Cripps, A.C.; Tang, J.Z. )

    1992-11-01

    Transparent evacuated insulation utilizes the same operating principles as the Dewar flask - gas conduction and convection are essentially eliminated by the evacuated space, and radiative heat transport is small because of internal low emittance coatings. These insulating structures consist of two flat sheets of glass with a hermetic edge seal. An array of support pillars is necessary to maintain the separation of the glass sheets under the influence of atmospheric pressure. The extensive literature on transparent evacuated insulation is reviewed. The design of these devices involves trade-offs between the heat flow through the pillars, and the mechanical stresses. A design methodology for determining the dimensions of the pillar array is developed. An analytic method is described for calculating the stresses and bending produced by a temperature difference across the structure. The results are in reasonable agreement with experimental measurements. The stresses within the structure are shown to be less than conventionally accepted levels over a wider range of operating conditions. Many samples of transparent evacuated insulation have been built and tested in which the heat transport through the evacuated space is due entirely to radiation, to the limit of resolution of the measuring device (0.2 W m{sup {minus}2}K{sup {minus}1}). No increase in heat transport has been observed over a period of 18 months. Much higher accuracy measurements have commenced. It appears likely that transparent evacuated insulation will achieve mid-plane insulating values of 0.6 W m{sup {minus}2}K{sup {minus}1}, and possibly somewhat lower.

  3. Metal nanowire-graphene composite transparent electrodes

    NASA Astrophysics Data System (ADS)

    Mankowski, Trent; Zhu, Zhaozhao; Balakrishnan, Kaushik; Shikoh, Ali Sehpar; Touati, Farid; Benammar, Mohieddine; Mansuripur, Masud; Falco, Charlies M.

    2014-10-01

    Silver nanowires with 40 nm diameter and copper nanowires with 150 nm diameter were synthesized using low-temperature routes, and deposited in combination with ultrathin graphene sheets for use as transparent conductors. A systematic and detailed analysis involving nature of capping agent for the metal nanowires, annealing of deposited films, and pre-treatment of substrates revealed critical conditions necessary for preparing high performance transparent conducting electrodes. The best electrodes show ~90% optical transmissivity and sheet resistance of ~10 Ω/□, already comparable to the best available transparent electrodes. The metal nanowire-graphene composite electrodes are therefore well suited for fabrication of opto-electronic and electronic devices.

  4. Transparent conductive graphene textile fibers.

    PubMed

    Neves, A I S; Bointon, T H; Melo, L V; Russo, S; de Schrijver, I; Craciun, M F; Alves, H

    2015-01-01

    Transparent and flexible electrodes are widely used on a variety of substrates such as plastics and glass. Yet, to date, transparent electrodes on a textile substrate have not been explored. The exceptional electrical, mechanical and optical properties of monolayer graphene make it highly attractive as a transparent electrode for applications in wearable electronics. Here, we report the transfer of monolayer graphene, grown by chemical vapor deposition on copper foil, to fibers commonly used by the textile industry. The graphene-coated fibers have a sheet resistance as low as ~1 kΩ per square, an equivalent value to the one obtained by the same transfer process onto a Si substrate, with a reduction of only 2.3 per cent in optical transparency while keeping high stability under mechanical stress. With this approach, we successfully achieved the first example of a textile electrode, flexible and truly embedded in a yarn. PMID:25952133

  5. Transparent conductive graphene textile fibers

    PubMed Central

    Neves, A. I. S.; Bointon, T. H.; Melo, L. V.; Russo, S.; de Schrijver, I.; Craciun, M. F.; Alves, H.

    2015-01-01

    Transparent and flexible electrodes are widely used on a variety of substrates such as plastics and glass. Yet, to date, transparent electrodes on a textile substrate have not been explored. The exceptional electrical, mechanical and optical properties of monolayer graphene make it highly attractive as a transparent electrode for applications in wearable electronics. Here, we report the transfer of monolayer graphene, grown by chemical vapor deposition on copper foil, to fibers commonly used by the textile industry. The graphene-coated fibers have a sheet resistance as low as ~1 kΩ per square, an equivalent value to the one obtained by the same transfer process onto a Si substrate, with a reduction of only 2.3 per cent in optical transparency while keeping high stability under mechanical stress. With this approach, we successfully achieved the first example of a textile electrode, flexible and truly embedded in a yarn. PMID:25952133

  6. Transparent conductive graphene textile fibers

    NASA Astrophysics Data System (ADS)

    Neves, A. I. S.; Bointon, T. H.; Melo, L. V.; Russo, S.; de Schrijver, I.; Craciun, M. F.; Alves, H.

    2015-05-01

    Transparent and flexible electrodes are widely used on a variety of substrates such as plastics and glass. Yet, to date, transparent electrodes on a textile substrate have not been explored. The exceptional electrical, mechanical and optical properties of monolayer graphene make it highly attractive as a transparent electrode for applications in wearable electronics. Here, we report the transfer of monolayer graphene, grown by chemical vapor deposition on copper foil, to fibers commonly used by the textile industry. The graphene-coated fibers have a sheet resistance as low as ~1 kΩ per square, an equivalent value to the one obtained by the same transfer process onto a Si substrate, with a reduction of only 2.3 per cent in optical transparency while keeping high stability under mechanical stress. With this approach, we successfully achieved the first example of a textile electrode, flexible and truly embedded in a yarn.

  7. Optical spectroscopic properties of active nano-crystal doped transparent glass composites

    NASA Astrophysics Data System (ADS)

    Myint, Thandar

    Cr4+ and some Cr3+ ions doped tunable laser media operate in optical telecommunication bands. The tunability of some Cr 3+ doped media cover the telecom O,E,S,C and L bands while Er doped glass, widely used in optical amplifiers, covers only C bands. If the telecom utilizes Cr doped materials as the amplified media in fiber lasers and amplifiers, it can revolutionize the optical communications. But making Cr doped crystal in fiber form is difficult and expensive while the glass is the best material to make the fiber form. One solution to solve this problem is to synthesize the glass composites which have the good mechanical properties of glasses and perfect optical properties of bulk single crystals. In this thesis, synthesis and optical properties of chromium doped transparent glass-ceramics with the chemical composition similar to Cunyite(Cr4+:Ca2GeO 4) laser crystal are presented. Broadband structureless fluorescence and high quantum efficiency of new glass-ceramic make it the promising medium for fiber lasers and amplifiers. One barrier in synthesizing the glass ceramics is controlling the size of the nanocrystals inside the glass matrix. Since the glass composite is a two-phase (glass and crystal phase) system, the size of nano-crystals must be small to reduce the scattering and consequently produce the transparent sample. In order to produce smaller nano-crystals inside the glass matrix, porous glass with pore size of 4nm is also investigated. The optical properties of synthesized porous-glass show the crystal having a few lattice parameters in size can be grown inside the pore network.

  8. Weak-light rogue waves, breathers, and their active control in a cold atomic gas via electromagnetically induced transparency

    NASA Astrophysics Data System (ADS)

    Liu, Junyang; Hang, Chao; Huang, Guoxiang

    2016-06-01

    We propose a scheme to demonstrate the existence of optical Peregrine rogue waves and Akhmediev and Kuznetsov-Ma breathers and realize their active control via electromagnetically induced transparency (EIT). The system we suggest is a cold, Λ -type three-level atomic gas interacting with a probe and a control laser fields and working under EIT condition. We show that, based on EIT with an incoherent optical pumping, which can be used to cancel optical absorption, (1+1)-dimensional optical Peregrine rogue waves, Akhmediev breathers, and Kuznetsov-Ma breathers can be generated with very low light power. In addition, we demonstrate that the Akhmediev and Kuznetsov-Ma breathers in (2+1)-dimensions obtained can be actively manipulated by using an external magnetic field. As a result, these breathers can display trajectory deflections and bypass obstacles during propagation.

  9. Flexible and Transparent Surface-Enhanced Raman Scattering (SERS)-Active Metafilm for Visualizing Trace Molecules via Raman Spectral Mapping.

    PubMed

    Liu, Xiangjiang; Wang, Jingjing; Wang, Jiajun; Tang, Longhua; Ying, Yibin

    2016-06-21

    Raman spectral mapping is a powerful tool for directly visualizing the composition, structure, and distribution of molecules on any surface of interest. However, one major limitation of Raman mapping is its overlong imaging time caused by the intrinsic weak Raman signal. Here, we developed a fast Raman imaging approach based on a flexible and transparent surface-enhanced Raman scattering (SERS)-active metafilm. This particular SERS substrate can be conformably attached to a sample surface to enhance the Raman signal of analytes and the good optical transparency allow excitation and collection of signal from the backside of the substrate. Therefore, by simply attaching it to the surface of interest, a fast Raman imaging can be realized. We noticed that the imaging speed can be increased by several orders of magnitude, compared to a conventional Raman mapping approach. Importantly, the proposed approach required little or no sample preparation and exhibited good generalizability that can be performed perfectly on different surfaces. It is believed that the proposed methodology will provide new trends for chemical imaging using Raman microscopy. PMID:27219332

  10. Active current sheets and candidate hot flow anomalies upstream of Mercury's bow shock

    NASA Astrophysics Data System (ADS)

    Uritsky, V. M.; Slavin, J. A.; Boardsen, S. A.; Sundberg, T.; Raines, J. M.; Gershman, D. J.; Collinson, G.; Sibeck, D.; Khazanov, G. V.; Anderson, B. J.; Korth, H.

    2014-02-01

    Hot flow anomalies (HFAs) represent a subset of solar wind discontinuities interacting with collisionless bow shocks. They are typically formed when the normal component of the motional (convective) electric field points toward the embedded current sheet on at least one of its sides. The core region of an HFA contains hot and highly deflected ion flows and rather low and turbulent magnetic field. In this paper, we report observations of possible HFA-like events at Mercury identified over a course of two planetary years. Using data from the orbital phase of the MESSENGER mission, we identify a representative ensemble of active current sheets magnetically connected to Mercury's bow shock. We show that some of these events exhibit magnetic and particle signatures of HFAs similar to those observed at other planets, and present their key physical characteristics. Our analysis suggests that Mercury's bow shock does not only mediate the flow of supersonic solar wind plasma but also provides conditions for local particle acceleration and heating as predicted by previous numerical simulations. Together with earlier observations of HFA activity at Earth, Venus, Mars, and Saturn, our results confirm that hot flow anomalies could be a common property of planetary bow shocks and show that the characteristic size of these events is controlled by the bow shock standoff distance and/or local solar wind conditions.

  11. Actively transparent display with enhanced legibility based on an organic light-emitting diode and a cholesteric liquid crystal blind panel.

    PubMed

    Yeon, Jeongho; Koh, Tae-Wook; Cho, Hyunsu; Chung, Jin; Yoo, Seunghyup; Yoon, Jun-Bo

    2013-04-22

    Transparent display is one of the most promising concepts among the next generation information display devices. Nevertheless, conventional transparent displays have two inherent problems: low forward light efficiency due to the light being emitted also in a backward direction; and low legibility due to the visual interruption caused by the light coming from the background. In this work, a cholesteric liquid crystal (Ch-LC) based, actively operational blind panel is combined with transparent organic light-emitting diodes (TR-OLEDs) to recycle the light wasted by backward propagation in transparent displays while blocking the light from behind the display, pursuing both improved forward light efficiency and enhanced image legibility. By tuning the reflectance spectrum of the Ch-LC panel to match the emission spectrum of TR-OLEDs, we achieved luminous efficiency increase by as large as 21% (85%) when the top metal cathode side (the bottom ITO side) of the OLEDs fa'transparent OLED' ces the blind panel. Maximum transmittance of the proposed device reached a high value of 60%, successfully demonstrating a new window-like transparent display concept. PMID:23609746

  12. Network formation through active migration of human vascular endothelial cells in a multilayered skeletal myoblast sheet.

    PubMed

    Nagamori, Eiji; Ngo, Trung Xuan; Takezawa, Yasunori; Saito, Atsuhiro; Sawa, Yoshiki; Shimizu, Tatsuya; Okano, Teruo; Taya, Masahito; Kino-oka, Masahiro

    2013-01-01

    Autologous transplantation of myoblast sheet has attracted attention as a new technique for curing myocardial infarction. Myoblast sheet has the ability to secret cytokines that improve heart function via the facilitation of angiogenesis on affected part. To mimic the in vivo angiogenesis in the myoblast sheet after transplantation, a five-layered cell sheet of human skeletal muscle myoblasts (HSMMs) was overlaid on human umbilical vein endothelial cells (HUVECs) which enables evaluation of dynamic HUVEC behavior. HUVECs existing initially at the bottom of the sheet changed to be a stretched shape and migrated upward compared with the surrounding HSMMs in the sheet. Prolonged incubation resulted in network formation of HUVECs in the middle of the sheet, although non-networked HUVECs continued to migrate to the top of the sheet, which meant the spatial habitation of HUVECs in the cell sheet. Image processing was performed to determine the variation in the extent of network formation at different HUVEC densities. It was found that the extent of formed network depended on the frequency of encounters among HUVECs in the middle of the sheet. The present system, which can evaluate network formation, is considered to be a promising in vitro angiogenesis model. PMID:23117213

  13. Polarised light sheet tomography.

    PubMed

    Reidt, Sascha L; O'Brien, Daniel J; Wood, Kenneth; MacDonald, Michael P

    2016-05-16

    The various benefits of light sheet microscopy have made it a widely used modality for capturing three-dimensional images. It is mostly used for fluorescence imaging, but recently another technique called light sheet tomography solely relying on scattering was presented. The method was successfully applied to imaging of plant roots in transparent soil, but is limited when it comes to more turbid samples. This study presents a polarised light sheet tomography system and its advantages when imaging in highly scattering turbid media. The experimental configuration is guided by Monte Carlo radiation transfer methods, which model the propagation of a polarised light sheet in the sample. Images of both reflecting and absorbing phantoms in a complex collagenous matrix were acquired, and the results for different polarisation configurations are compared. Focus scanning methods were then used to reduce noise and produce three-dimensional reconstructions of absorbing targets. PMID:27409945

  14. ASYMMETRIC SUNSPOT ACTIVITY AND THE SOUTHWARD DISPLACEMENT OF THE HELIOSPHERIC CURRENT SHEET

    SciTech Connect

    Wang, Y.-M.; Robbrecht, E. E-mail: eva.robbrecht@oma.be

    2011-08-01

    Observations of the interplanetary magnetic field (IMF) have suggested a statistical tendency for the heliospheric current sheet (HCS) to be shifted a few degrees southward of the heliographic equator during the period 1965-2010, particularly in the years near sunspot minimum. Using potential-field source-surface extrapolations and photospheric flux-transport simulations, we demonstrate that this southward displacement follows from Joy's law and the observed hemispheric asymmetry in the sunspot numbers, with activity being stronger in the southern (northern) hemisphere during the declining (rising) phase of cycles 20-23. The hemispheric asymmetry gives rise to an axisymmetric quadrupole field, whose equatorial zone has the sign of the leading-polarity flux in the dominant hemisphere; during the last four cycles, the polarity of the IMF around the equator thus tended to match that of the north polar field both before and after polar field reversal. However, large fluctuations are introduced by the nonaxisymmetric field components, which depend on the longitudinal distribution of sunspot activity in either hemisphere. Consistent with this model, the HCS showed an average northward displacement during cycle 19, when the 'usual' alternation was reversed and the northern hemisphere became far more active than the southern hemisphere during the declining phase of the cycle. We propose a new method for determining the north-south displacement of the HCS from coronal streamer observations.

  15. The heliospheric sheet configuration according to the coronal ray synoptic maps in solar activity cycles 23 and 24

    NASA Astrophysics Data System (ADS)

    Guseva, S. A.; Fat'yanov, M. P.; Shramko, A. D.

    2015-05-01

    Two catalogs of coronal ray synoptic maps for different altitudes (1.5-5 R ⊙) for solar activity cycles 23 and 24 (1996-2013) were compiled based on a proposed technique with the data from the SOHO space observatory LASCO C2 coronograph and the Mauna-Loa observatory Mark-IV K coronometer. The constructed synoptic maps of coronal rays represent an image of three-dimensional spherical sections of the heliospheric neutral sheet expanded along the heliographic longitude. The evolution of different heliospheric sheet spatial parameters during the analyzed period was studied based on the obtained maps.

  16. Anti-adhesion and antibacterial activity of silver nanoparticles supported on graphene oxide sheets.

    PubMed

    de Faria, Andreia Fonseca; Martinez, Diego Stéfani Teodoro; Meira, Stela Maris Meister; de Moraes, Ana Carolina Mazarin; Brandelli, Adriano; Filho, Antonio Gomes Souza; Alves, Oswaldo Luiz

    2014-01-01

    This work reports on the preparation, characterization and antibacterial activity of a nanocomposite formed from graphene oxide (GO) sheets decorated with silver nanoparticles (GO-Ag). The GO-Ag nanocomposite was prepared in the presence of AgNO3 and sodium citrate. The physicochemical characterization was performed by UV-vis spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), Raman spectroscopy and transmission electron microscopy (TEM). The average size of the silver nanoparticles anchored on the GO surface was 7.5 nm. Oxidation debris fragments (a byproduct adsorbed on the GO surface) were found to be crucial for the nucleation and growth of the silver nanoparticles. The antibacterial activity of the GO and GO-Ag nanocomposite against the microorganism Pseudomonas aeruginosa was investigated using the standard counting plate methodology. The GO dispersion showed no antibacterial activity against P. aeruginosa over the concentration range investigated. On the other hand, the GO-Ag nanocomposite displayed high biocidal activity with a minimum inhibitory concentration ranging from 2.5 to 5.0 μg/mL. The anti-biofilm activity toward P. aeruginosa adhered on stainless steel surfaces was also investigated. The results showed a 100% inhibition rate of the adhered cells after exposure to the GO-Ag nanocomposite for one hour. To the best of our knowledge, this work provides the first direct evidence that GO-Ag nanocomposites can inhibit the growth of microbial adhered cells, thus preventing the process of biofilm formation. These promising results support the idea that GO-Ag nanocomposites may be applied as antibacterial coatings material to prevent the development of biofilms in food packaging and medical devices. PMID:24060936

  17. High-performance single-crystalline arsenic-doped indium oxide nanowires for transparent thin-film transistors and active matrix organic light-emitting diode displays.

    PubMed

    Chen, Po-Chiang; Shen, Guozhen; Chen, Haitian; Ha, Young-geun; Wu, Chao; Sukcharoenchoke, Saowalak; Fu, Yue; Liu, Jun; Facchetti, Antonio; Marks, Tobin J; Thompson, Mark E; Zhou, Chongwu

    2009-11-24

    We report high-performance arsenic (As)-doped indium oxide (In(2)O(3)) nanowires for transparent electronics, including their implementation in transparent thin-film transistors (TTFTs) and transparent active-matrix organic light-emitting diode (AMOLED) displays. The As-doped In(2)O(3) nanowires were synthesized using a laser ablation process and then fabricated into TTFTs with indium-tin oxide (ITO) as the source, drain, and gate electrodes. The nanowire TTFTs on glass substrates exhibit very high device mobilities (approximately 1490 cm(2) V(-1) s(-1)), current on/off ratios (5.7 x 10(6)), steep subthreshold slopes (88 mV/dec), and a saturation current of 60 microA for a single nanowire. By using a self-assembled nanodielectric (SAND) as the gate dielectric, the device mobilities and saturation current can be further improved up to 2560 cm(2) V(-1) s(-1) and 160 microA, respectively. All devices exhibit good optical transparency (approximately 81% on average) in the visible spectral range. In addition, the nanowire TTFTs were utilized to control green OLEDs with varied intensities. Furthermore, a fully integrated seven-segment AMOLED display was fabricated with a good transparency of 40% and with each pixel controlled by two nanowire transistors. This work demonstrates that the performance enhancement possible by combining nanowire doping and self-assembled nanodielectrics enables silicon-free electronic circuitry for low power consumption, optically transparent, high-frequency devices assembled near room temperature. PMID:19842677

  18. Enhanced transparency, mechanical durability, and antibacterial activity of zinc nanoparticles on glass substrate

    PubMed Central

    Choi, Hyung-Jin; Choi, Jin-Seok; Park, Byeong-Ju; Eom, Ji-Ho; Heo, So-Young; Jung, Min-Wook; An, Ki-Seok; Yoon, Soon-Gil

    2014-01-01

    Homogeneously distributed zinc nanoparticles (NPs) on the glass substrate were investigated for the transmittance, mechanical durability, and antibacterial effect. The buffered Ti NPs between Zn NPs and glass substrate were studied for an enhancement of the transmittance and mechanical endurance. The Ti NPs buffered Zn NPs showed a high transmittance of approximately 91.5% (at a wavelength of 550 nm) and a strong antibacterial activity for Staphylococcus aureus and Escherichia coli bacteria. The buffered Ti NPs are attractive for an excellent mechanical endurance of the Zn NPs. The Zn NPs did not require the protection layer to prevent the degradation of the performance for both the antibacterial effect and the transmittance. PMID:25183360

  19. Seismicity on the western Greenland Ice Sheet: Surface fracture in the vicinity of active moulins

    SciTech Connect

    Carmichael, Joshua D.; Joughin, Ian; Behn, Mark D.; Das, Sarah; King, Matt A.; Stevens, Laura; Lizarralde, Dan

    2015-06-25

    We analyzed geophone and GPS measurements collected within the ablation zone of the western Greenland Ice Sheet during a ~35 day period of the 2011 melt season to study changes in ice deformation before, during, and after a supraglacial lake drainage event. During rapid lake drainage, ice flow speeds increased to ~400% of winter values, and icequake activity peaked. At times >7 days after drainage, this seismicity developed variability over both diurnal and longer periods (~10 days), while coincident ice speeds fell to ~150% of winter values and showed nightly peaks in spatial variability. Approximately 95% of all detected seismicity in the lake basin and its immediate vicinity was triggered by fracture propagation within near-surface ice (<330 m deep) that generated Rayleigh waves. Icequakes occurring before and during drainage frequently were collocated with the down flow (west) end of the primary hydrofracture through which the lake drained but shifted farther west and outside the lake basin after the drainage. We interpret these results to reveal vertical hydrofracture opening and local uplift during the drainage, followed by enhanced seismicity and ice flow on the downstream side of the lake basin. This region collocates with interferometric synthetic aperture radar-measured speedup in previous years and could reflect the migration path of the meltwater supplied to the bed by the lake. The diurnal seismic signal can be associated with nightly reductions in surface melt input that increase effective basal pressure and traction, thereby promoting elevated strain in the surficial ice.

  20. Field-Aligned Current Sheet Motion and Its Correlation with Solar Wind Conditions and Geomagnetic Activities

    NASA Astrophysics Data System (ADS)

    Wang, Y.; Le, G.; Boardsen, S. A.; Slavin, J. A.; Strangeway, R. J.

    2008-05-01

    Field-aligned currents (FACs) are the currents flowing into and out of the ionosphere which connect to the magnetosphere. They provide an essential linkage between the solar wind - magnetosphere system and the ionosphere, and the understanding of these currents is important for global magnetosphere dynamics and space weather prediction. The three spacecraft ST-5 constellation provides an unprecedented opportunity to study in situ FAC dynamics in time scales (10 sec to 10 min) that can not be achieved previously with single spacecraft studies or large-spaced conjugate spacecraft studies. In this study, we use the magnetic field observations during the whole ST-5 mission and their corresponding solar wind conditions to study the dependence of FAC current sheet motion and intensity on solar wind conditions. FAC peak current densities show very good correlations with some solar wind parameters, including IMF Bz, dynamic pressure, Ey, and some IMF angles, but not with other parameters. Instant FAC speeds show generally much weaker dependence on solar wind conditions comparing to FAC peak current densities. This obvious uncorrelation between FAC peak current densities and speeds implies that FAC peak current densities are more consistently controlled by solar wind conditions and geomagnetic activities, while FAC speeds are more oscillatory, sometimes with higher speeds during quieter times and lower speeds during more turbulent times.

  1. Anatase TiO2 nanocrystals with exposed {001} facets on graphene sheets via molecular grafting for enhanced photocatalytic activity.

    PubMed

    Sun, Lei; Zhao, Zhenlu; Zhou, Yunchun; Liu, Li

    2012-01-21

    Owing to their extensive practical applications and fundamental importance, the controllable synthesis of well-faceted anatase TiO(2) crystal with high percentage of reactive facets has attracted increasing attention. Here, nano-sized anatase TiO(2) sheets mainly dominated by {001} facets had been prepared on graphene sheets by using a facile solvothermal synthetic route. The percentage of {001} facets in TiO(2) nanosheets was calculated to be ca. 64%. The morphologies, structural properties, growth procedures and photocatalytic activities of the resultant TiO(2)/graphene nanocomposites were investigated. In comparison with commercial P25 and pure TiO(2) nanosheets, the composite exhibited significant improvement in photocatalytic degradation of the azo dye Rhodamine B under visible light irradiation. The enhancement of photocatalytic activity and stability was attributed to the effective charge anti-recombination of graphene and the high catalytic activity of {001} facets. PMID:22159272

  2. [The influence of anodizing conditions on the activity of urease immobilized to anodized sheet aluminium (author's transl)].

    PubMed

    Grunwald, P; Grunsser, W; Pfaff, K P; Krause, R; Lutz, K

    1980-01-01

    The activity of urease immobilized by adsorption on anodized sheet aluminium strongly depends on the method chosen for preparation of these carriers. If oxalic acid is applied as electrolyte, only the anodizing temperature significantly influences the activity of the preparations. In case of the well-known GS process, however, the activity is not only affected by the temperature, but also by other conditions of anodizing, for example the current density and the electrolyte concentration. For both methods the correlation between the topography of the carrier surfaces and the activity of enzyme immobilized to the surface is described. PMID:7445681

  3. Electric fields measured by ISEE-1 within and near the neutral sheet during quiet and active times

    NASA Technical Reports Server (NTRS)

    Cattell, C. A.; Mozer, F. S.

    1982-01-01

    An understanding of the physical processes occurring in the magnetotail and plasmasheet during different interplanetary magnetic field orientations and differing levels of ground magnetic activity is crucial for the development of a theory of energy transfer from the solar wind to the particles which produce auroral arcs. In the present investigation, the first observations of electric fields during neutral sheet crossings are presented, taking into account the statistical correlations of the interplanetary magnetic field direction and ground activity with the character of the electric field. The electric field data used in the study were obtained from a double probe experiment on the ISEE-1 satellite. The observations suggest that turbulent electric and magnetic fields are intimately related to plasma acceleration in the neutral sheet and to the processes which create auroral particles.

  4. Photopatternable transparent conducting oxide nanoparticles for transparent electrodes

    NASA Astrophysics Data System (ADS)

    Kim, Won Jin; Kim, Sung Jin; Cartwright, Alexander N.; Prasad, Paras N.

    2013-02-01

    We report a method to fabricate tailored transparent electrodes using photopatternable transparent conducting oxide nanoparticles (TCO NPs). We demonstrate solution-processed micropatterns by a conventional photolithography technique. We have synthesized indium tin oxide (ITO) NPs and functionalized them with a photolabile group, such as t-butoxycarbonyl (t-BOC), which can be deprotected by a chemical amplification reaction in the solid state film. The chemical amplification reaction leads to a shortening of the ligand that changes the solubility of the resulting ITO films. This ligand shortening process also contributes to a reduction of the sheet resistance in the resulting photopatterned ITO films. Furthermore, we have demonstrated the general viability and strength of this approach by also photopatterning zinc oxide (ZnO) NPs.

  5. Modeling the transition between upper plane bed regime and sheet flow without an active layer formulation. Preliminary results.

    NASA Astrophysics Data System (ADS)

    Viparelli, E.; Hernandez Moreira, R. R.; Blom, A.

    2015-12-01

    A perusal of the literature on bedload transport revealed that, notwithstanding the large number of studies on bedform morphology performed in the past decades, the upper plane bed regime has not been thoroughly investigated and the distinction between the upper plane bed and sheet flow transport regimes is still poorly defined. Previous experimental work demonstrated that the upper plane bed regime is characterized by long wavelength and small amplitude bedforms that migrate downstream. These bedforms, however, were not observed in experiments on sheet flow transport suggesting that the upper plane bed and the sheet flow are two different regimes. We thus designed and performed experiments in a sediment feed flume in the hydraulic laboratory of the Department of Civil and Environmental Engineering at the University of South Carolina at Columbia to study the transition from upper plane bed to sheet flow regime. Periodic measurements of water surface and bed elevation, bedform geometry and thicknesses of the bedload layer were performed by eyes, and with cameras, movies and a system of six ultrasonic probes that record the variations of bed elevation at a point over time. We used the time series of bed elevations to determine the probability functions of bed elevation. These probability functions are implemented in a continuous model of river morphodynamics, i.e. a model that does not use the active layer approximation to describe the sediment fluxes between the bedload and the deposit and that should thus be able to capture the details of the vertical and streamwise variation of the deposit grain size distribution. This model is validated against the experimental results for the case of uniform material. We then use the validated model in the attempt to study if and how the spatial distribution of grain sizes in the deposit changes from upper plane bed regime to sheet flow and if these results are influenced by the imposed rates of base level rise.

  6. Seismicity on the western Greenland Ice Sheet: Surface fracture in the vicinity of active moulins

    DOE PAGESBeta

    Carmichael, Joshua D.; Joughin, Ian; Behn, Mark D.; Das, Sarah; King, Matt A.; Stevens, Laura; Lizarralde, Dan

    2015-06-25

    We analyzed geophone and GPS measurements collected within the ablation zone of the western Greenland Ice Sheet during a ~35 day period of the 2011 melt season to study changes in ice deformation before, during, and after a supraglacial lake drainage event. During rapid lake drainage, ice flow speeds increased to ~400% of winter values, and icequake activity peaked. At times >7 days after drainage, this seismicity developed variability over both diurnal and longer periods (~10 days), while coincident ice speeds fell to ~150% of winter values and showed nightly peaks in spatial variability. Approximately 95% of all detected seismicitymore » in the lake basin and its immediate vicinity was triggered by fracture propagation within near-surface ice (<330 m deep) that generated Rayleigh waves. Icequakes occurring before and during drainage frequently were collocated with the down flow (west) end of the primary hydrofracture through which the lake drained but shifted farther west and outside the lake basin after the drainage. We interpret these results to reveal vertical hydrofracture opening and local uplift during the drainage, followed by enhanced seismicity and ice flow on the downstream side of the lake basin. This region collocates with interferometric synthetic aperture radar-measured speedup in previous years and could reflect the migration path of the meltwater supplied to the bed by the lake. The diurnal seismic signal can be associated with nightly reductions in surface melt input that increase effective basal pressure and traction, thereby promoting elevated strain in the surficial ice.« less

  7. Polarization features of solar radio emission and possible existence of current sheets in active regions

    NASA Technical Reports Server (NTRS)

    Gopalswamy, N.; Zheleznyakov, V. V.; White, S. M.; Kundu, M. R.

    1994-01-01

    We show that it is possible to account for the polarization features of solar radio emission provided the linear mode coupling theory is properly applied and the presence of current sheets in the corona is taken into account. We present a schematic model, including a current sheet that can explain the polarization features of both the low frequency slowly varying component and the bipolar noise storm radiation; the two radiations face similar propagation conditions through a current sheet and hence display similar polarization behavior. We discuss the applications of the linear mode coupling theory to the following types of solar emission: the slowly varying component, the microwave radio bursts, metric type U bursts, and bipolar noise storms.

  8. A melamine-assisted chemical blowing synthesis of N-doped activated carbon sheets for supercapacitor application

    NASA Astrophysics Data System (ADS)

    Wang, Yiliang; Xuan, Huaqing; Lin, Gaoxin; Wang, Fan; Chen, Zhi; Dong, Xiaoping

    2016-07-01

    N-doped activated carbon sheets (NACS) have been successfully synthesized using glucose as carbon source via melamine-assisted chemical blowing and sequent KOH-activation method. The obtained carbon material possesses a sheet-like morphology with ultrathin thickness, hierarchical micro/mesoporous structure, high specific surface area (up to 1997.5 m2 g-1) and high pore volume (0.94 cm3 g-1). Besides, NACS material with a nitrogen content of 3.06 wt% presents a maximum specific capacitance of 312 F g-1 at a current density of 0.5 A g-1 in 6 M KOH aqueous electrolyte due to the cocontribution of double layer capacitance and pseudocapacitance. It also displays good rate performance (246 F g-1 at 30 A g-1) and cycle stability (∼91.3% retention after 4000 galvanostatic charge-discharge cycles). The assembled NACS-based symmetric capacitor exhibits a maximum energy density of 20.2 Wh kg-1 at a power density of 448 W kg-1 within a voltage range of 0-1.8 V in 0.5 M Na2SO4 aqueous electrolyte. Thus, the unique porous sheet structure and nitrogen-doping characteristic endue the electrode material a potential application for high-performance supercapacitors.

  9. Photocatalytic activity and antimicrobial properties of paper sheets modified with TiO2/Sodium alginate nanocomposites.

    PubMed

    Abdel Rehim, Mona H; El-Samahy, Magda A; Badawy, Abdelrahman A; Mohram, Maysa E

    2016-09-01

    Photocatalytic paper sheets were prepared by addition of different ratios of TiO2/Sodium alginate (TSA) nanocomposite. The modified paper sheets were characterized by XRD, TGA. Their morphology was studied by scanning electron microscope (SEM) and energy dispersive X-ray (EDX). Photocatalytic activity of modified paper has been studied by analysis of chemical oxygen demand (COD) of waste-water. The results confirmed the mineralization of the waste-water and enhanced removal of chemical oxygen demand (COD) by increasing the amount of photocatalyst in the paper. Moreover, the results also confirmed that presence of sodium alginate as biopolymer increased adhesion of nanoparticles to paper fibers and reduced the harmful effect of the photocatalyst on them. The paper sheets containing 7% as well as 15% TSA showed high photocatalytic activity and anti-bacterial effect against Salmonella typhimurium higher than standard antibiotic beside other microorganisms such as Candida albicans. The maximum antimicrobial effect was found in case of specimen loaded with 15% TSA. Moreover, it was found that by adding 20% TSA to the paper matrix, the properties of the paper composite collapse. The obtained results confirm the possible utilization of the modified paper in both hygienic and food packaging applications. PMID:27185131

  10. Co-Percolating Graphene-Wrapped Silver Nanowire Network for High Performance, Highly Stable, Transparent Conducting Electrodes

    SciTech Connect

    Chen, Ruiyi; Das, Suprem R; Jeong, Changwook; Khan, Mohammad Ryyan; Janes, David B; Alam, Muhammad A

    2013-04-25

    Transparent conducting electrodes (TCEs) require high transparency and low sheet resistance for applications in photovoltaics, photodetectors, flat panel displays, touch screen devices, and imagers. Indium tin oxide (ITO), or other transparent conductive oxides, have been used, and provide a baseline sheet resistance (RS) vs. transparency (T) relationship. Several alternative material systems have been investigated. The development of high-performance hybrid structures provides a route towards robust, scalable and low-cost approaches for realizing high-performance TCE.

  11. Surface Structure Dependent Electrocatalytic Activity of Co3O4 Anchored on Graphene Sheets toward Oxygen Reduction Reaction

    PubMed Central

    Xiao, Junwu; Kuang, Qin; Yang, Shihe; Xiao, Fei; Wang, Shuai; Guo, Lin

    2013-01-01

    Catalytic activity is primarily a surface phenomenon, however, little is known about Co3O4 nanocrystals in terms of the relationship between the oxygen reduction reaction (ORR) catalytic activity and surface structure, especially when dispersed on a highly conducting support to improve the electrical conductivity and so to enhance the catalytic activity. Herein, we report a controllable synthesis of Co3O4 nanorods (NR), nanocubes (NC) and nano-octahedrons (OC) with the different exposed nanocrystalline surfaces ({110}, {100}, and {111}), uniformly anchored on graphene sheets, which has allowed us to investigate the effects of the surface structure on the ORR activity. Results show that the catalytically active sites for ORR should be the surface Co2+ ions, whereas the surface Co3+ ions catalyze CO oxidation, and the catalytic ability is closely related to the density of the catalytically active sites. These results underscore the importance of morphological control in the design of highly efficient ORR catalysts. PMID:23892418

  12. Probing the interactions of phenol with oxygenated functional groups on curved fullerene-like sheets in activated carbon.

    PubMed

    Yin, Chun-Yang; Ng, Man-Fai; Goh, Bee-Min; Saunders, Martin; Hill, Nick; Jiang, Zhong-Tao; Balach, Juan; El-Harbawi, Mohanad

    2016-02-01

    The mechanism(s) of interactions of phenol with oxygenated functional groups (OH, COO and COOH) in nanopores of activated carbon (AC) is a contentious issue among researchers. This mechanism is of particular interest because a better understanding of the role of such groups in nanopores would essentially translate to advances in AC production and use, especially in regard to the treatment of organic-based wastewaters. We therefore attempt to shed more light on the subject by employing density functional theory (DFT) calculations in which fullerene-like models integrating convex or concave structure, which simulate the eclectic porous structures on AC surface, are adopted. TEM analysis, EDS mapping and Boehm titration are also conducted on actual phenol-adsorbed AC. Our results suggest the widely-reported phenomenon of decreased phenol uptake on AC due to increased concentration of oxygenated functional groups is possibly attributed to the increased presence of the latter on the convex side of the curved carbon sheets. Such a system effectively inhibits phenol from getting direct contact with the carbon sheet, thus constraining any available π-π interaction, while the effect of groups acting on the concave part of the curved sheet does not impart the same detriment. PMID:26760531

  13. Terahertz induced transparency in single-layer graphene

    SciTech Connect

    Paul, Michael J.; Lee, Byounghwak; Wardini, Jenna L.; Thompson, Zachary J.; Stickel, Andrew D.; Mousavian, Ali; Minot, Ethan D.; Lee, Yun-Shik; Choi, Hyunyong

    2014-12-01

    We show that the transmission of a terahertz (THz) pulse through single-layer graphene is strongly nonlinear. As the peak electric field of the THz pulse exceeds 50 kV/cm, the graphene becomes increasingly transparent to the THz radiation. When field strength reaches 800 kV/cm, the increased transparency corresponds to a two-fold decrease in the time-average sheet conductivity of the graphene (time averaged over the duration of the pulse). Time-resolved measurements reveal that the leading portion of the pulse creates transparency for the trailing portion, with a 10-fold suppression in sheet conductivity at the tail of the strongest THz pulse. Comparing the THz-induced transparency phenomena in different sample geometries shows that substrate-free graphene is the best geometry for maximizing the nonlinear transparency effect.

  14. Anatase TiO2 nanocrystals with exposed {001} facets on graphene sheets via molecular grafting for enhanced photocatalytic activity

    NASA Astrophysics Data System (ADS)

    Sun, Lei; Zhao, Zhenlu; Zhou, Yunchun; Liu, Li

    2012-01-01

    Owing to their extensive practical applications and fundamental importance, the controllable synthesis of well-faceted anatase TiO2 crystal with high percentage of reactive facets has attracted increasing attention. Here, nano-sized anatase TiO2 sheets mainly dominated by {001} facets had been prepared on graphene sheets by using a facile solvothermal synthetic route. The percentage of {001} facets in TiO2 nanosheets was calculated to be ca. 64%. The morphologies, structural properties, growth procedures and photocatalytic activities of the resultant TiO2/graphene nanocomposites were investigated. In comparison with commercial P25 and pure TiO2 nanosheets, the composite exhibited significant improvement in photocatalytic degradation of the azo dye Rhodamine B under visible light irradiation. The enhancement of photocatalytic activity and stability was attributed to the effective charge anti-recombination of graphene and the high catalytic activity of {001} facets.Owing to their extensive practical applications and fundamental importance, the controllable synthesis of well-faceted anatase TiO2 crystal with high percentage of reactive facets has attracted increasing attention. Here, nano-sized anatase TiO2 sheets mainly dominated by {001} facets had been prepared on graphene sheets by using a facile solvothermal synthetic route. The percentage of {001} facets in TiO2 nanosheets was calculated to be ca. 64%. The morphologies, structural properties, growth procedures and photocatalytic activities of the resultant TiO2/graphene nanocomposites were investigated. In comparison with commercial P25 and pure TiO2 nanosheets, the composite exhibited significant improvement in photocatalytic degradation of the azo dye Rhodamine B under visible light irradiation. The enhancement of photocatalytic activity and stability was attributed to the effective charge anti-recombination of graphene and the high catalytic activity of {001} facets. Electronic supplementary information (ESI

  15. Metal Ion Intercalated graphitic as Transparent Electrodes

    NASA Astrophysics Data System (ADS)

    Wan, Jiayu; Bao, Wenzhong; Gu, Feng; Fuhrer, Michael; Hu, Liangbing; UMD Team

    To best utilize the performance of graphene based transparent electrodes, we novelized Li-ion intercalation in graphene, and achieved highest performance of carbon based transparent electrodes. Transmission as high as 91.7% with a sheet resistance of 3.0 ohm/sq is achieved for 19-layer LiC6, significantly higher than any other continuous transparent electrodes. The unconventional modification of ultrathin graphite optoelectronic properties is explained by the suppression of interband optical transitions and a small intraband Drude conductivity near the interband edge. To achieve low cost, large scale graphene-based transparent electrodes, we further developed Na-ion intercalated printed reduced graphene oxide (RGO) film. The larger layer-layer distance of RGO allows Na-ion intercalation, leading to simultaneously much higher DC conductivity and higher optical transmittance. Typical increase of transmittance from 36% to 79% and decrease of sheet resistance from 83 kohms/sq to 311 ohms/sq in the printed network was observed. This study demonstrated the great potential of metal-ion intercalation to improve the performance of graphene-based materials for transparent conductor applications.

  16. Making Ordered DNA and Protein Structures from Computer-Printed Transparency Film Cut-Outs

    ERIC Educational Resources Information Center

    Jittivadhna, Karnyupha; Ruenwongsa, Pintip; Panijpan, Bhinyo

    2009-01-01

    Instructions are given for building physical scale models of ordered structures of B-form DNA, protein [alpha]-helix, and parallel and antiparallel protein [beta]-pleated sheets made from colored computer printouts designed for transparency film sheets. Cut-outs from these sheets are easily assembled. Conventional color coding for atoms are used…

  17. Effect of OSHA's bloodborne pathogens standard on hazardous waste cleanup activities. Fact sheet

    SciTech Connect

    Not Available

    1993-08-01

    Bloodborne pathogens are microorganisms that are present in human blood and can cause disease in humans. These pathogens include, but are not limited to, hepatitis B virus (HBV) and human immunodeficiency virus (HIV). In addition to healthcare workers, the standard also may affect workers who handle waste potentially contaminated with blood or other potentially infectious material during response actions at uncontrolled hazardous waste sites. The purpose of the Fact Sheet is to describe the additional planning, training, and medical surveillance requirements that the new OSHA standard on bloodborne pathogens imposes upon On-Scene Coordinators (OSCs) and Remedial Project Managers (RPMs) during a Superfund response action.

  18. EDITORIAL: On display with transparent conducting films On display with transparent conducting films

    NASA Astrophysics Data System (ADS)

    Demming, Anna

    2012-03-01

    the sheet resistance of HNO3 treated carbon-nanotube films than the removal of residual N-methylpyrrolidone. Unsurprisingly graphene, the latest carbon wonder material, has also shown remarkable potential as a transparent conducting film. Chemical vapour deposition (CVD) synthesis of graphene has the advantage that it allows fabrication of the sheets to be scaled up. A collaboration of researchers in the USA, Singapore and Korea demonstrated that the conductivity of CVD graphene sheets can be improved by p-doping with AuCl3 [9]. The potential of graphene in a range of applications is also being demonstrated, as researchers in Australia and China show in a report on graphene in transparent conducting electrodes for GaN LED devices [10]. The review in this issue [4] provides a comprehensive overview of graphene as an electrode, including the synthesis, chemical doping and work function engineering of the material, as well as applications in transistors, memories, molecular junctions, touch screens, LCDs, LEDs and solar cells. Back in the early 1950s Gillham and Preston saw the possibility of using their gold sputtered bismuth oxide films for windows that could be electrically heated and took out a patent on their discovery [11]. While they saw potential applications for conducting transparent films, it could be argued that even Gillham and Preston would have been surprised at the extent to which transparent conducting films have infiltrated everyday technology over the 60 years since. It is tempting to wonder what wide reaching ramifications the current fruitful activity in graphene device research may have in the decades to come. References [1] Ayrton W E and Mather T 1894 J. Int. Elec. Eng. 23 376-80 [2] Gillham E J and Preston J S 1952 Proc. Phys. Soc. B 65 649 [3] Ishiguro K, Sasaki T, Arai T and Imai I 1958 J. Phys. Soc. Jpn. 13 296-304 [4] Jo G, Choe M, Lee S, Park W, Kahng Y H and Lee T 2012 Nanotechnology 23 112001 [5] Guo P and Aegerter M A 1999 Thin Solid

  19. Evaluating conducting network based transparent electrodes from geometrical considerations

    NASA Astrophysics Data System (ADS)

    Kumar, Ankush; Kulkarni, G. U.

    2016-01-01

    Conducting nanowire networks have been developed as viable alternative to existing indium tin oxide based transparent electrode (TE). The nature of electrical conduction and process optimization for electrodes have gained much from the theoretical models based on percolation transport using Monte Carlo approach and applying Kirchhoff's law on individual junctions and loops. While most of the literature work pertaining to theoretical analysis is focussed on networks obtained from conducting rods (mostly considering only junction resistance), hardly any attention has been paid to those made using template based methods, wherein the structure of network is neither similar to network obtained from conducting rods nor similar to well periodic geometry. Here, we have attempted an analytical treatment based on geometrical arguments and applied image analysis on practical networks to gain deeper insight into conducting networked structure particularly in relation to sheet resistance and transmittance. Many literature examples reporting networks with straight or curvilinear wires with distributions in wire width and length have been analysed by treating the networks as two dimensional graphs and evaluating the sheet resistance based on wire density and wire width. The sheet resistance values from our analysis compare well with the experimental values. Our analysis on various examples has revealed that low sheet resistance is achieved with high wire density and compactness with straight rather than curvilinear wires and with narrower wire width distribution. Similarly, higher transmittance for given sheet resistance is possible with narrower wire width but of higher thickness, minimal curvilinearity, and maximum connectivity. For the purpose of evaluating active fraction of the network, the algorithm was made to distinguish and quantify current carrying backbone regions as against regions containing only dangling or isolated wires. The treatment can be helpful in predicting

  20. Transparent electrode with a nanostructured coating.

    PubMed

    Huang, Yan Y; Terentjev, Eugene M

    2011-03-22

    Using single-walled nanotubes as an example, we fabricated transparent conductive coatings and demonstrated a new technique of centrifuge coating as a potential low-waste, solution-based batch process for the fabrication of nanostructured coatings. A theoretical model is developed to account for the sheet resistance exhibited by layered random-network coatings such as nanofilaments and graphene. The model equation is analytical and compact, and allows the correlation of very different scaling regimes reported in the literature to the underlying coating microstructure. Finally, we also show a refined experimental setup to systematically measure the curvature-dependent sheet resistance. PMID:21370898

  1. Soils. Transparency Masters.

    ERIC Educational Resources Information Center

    Clemson Univ., SC. Vocational Education Media Center.

    This document is a collection of 43 overhead transparency masters to be used as teaching aids in a course of study involving soils such as geology, agronomy, hydrology, earth science, or land use study. Some transparencies are in color. Selected titles of transparencies may give the reader a better understanding of the graphic content. Titles are:…

  2. Nitrogen-doped graphene as transparent counter electrode for efficient dye-sensitized solar cells

    SciTech Connect

    Wang, Guiqiang; Fang, Yanyan; Lin, Yuan; Xing, Wei; Zhuo, Shuping

    2012-12-15

    Graphical abstract: Display Omitted Highlights: ► NG sheets are prepared through a hydrothermal reduction of graphite oxide. ► The transparent NG counter electrodes of DSCs are fabricated at room temperature. ► Transparent NG electrode exhibits excellent catalytic activity for the reduction of I{sub 3}{sup −}. ► The DSC with NG electrode achieves a comparable efficiency to that of the Pt-based cell. ► The efficiency of rear illumination is about 85% that of front illumination. -- Abstract: Nitrogen-doped graphene sheets are prepared through a hydrothermal reduction of graphite oxide in the presence of ammonia and applied to fabricate the transparent counter electrode of dye-sensitized solar cells. The atomic percentage of nitrogen in doped graphene sample is about 2.5%, and the nitrogen bonds display pyridine and pyrrole-like configurations. Cyclic voltammetry studies demonstrate a much higher electrocatalytic activity toward I{sup −}/I{sub 3}{sup −} redox reaction for nitrogen-doped graphene, as compared with pristine graphene. The dye-sensitized solar cell with this transparent nitrogen-doped graphene counter electrode shows conversion efficiencies of 6.12% and 5.23% corresponding to front-side and rear-side illumination, respectively. Meanwhile, the cell with a Pt counter electrode shows a conversion efficiency of 6.97% under the same experimental condition. These promising results highlight the potential application of nitrogen-doped graphene in cost-effective, transparent dye-sensitized solar cells.

  3. So What's It to Me? Sexual Assault Information for Guys: Activity Guide.

    ERIC Educational Resources Information Center

    Stringer, Gayle M.; Rants-Rodriguez, Deanna

    This document is a group leader activity guide to accompany a sexual assault prevention program focusing on information for male teenagers. Background information, large group activities, comments for small group leaders, extension activities, activity sheets, and transparency masters are included for 15 group activities. These topics are covered…

  4. Wetting transparency of graphene in water

    NASA Astrophysics Data System (ADS)

    Driskill, Joshua; Vanzo, Davide; Bratko, Dusan; Luzar, Alenka

    2014-11-01

    Measurements of contact angle on graphene sheets show a notable dependence on the nature of the underlying substrate, a phenomenon termed wetting transparency. Our molecular modeling studies reveal analogous transparency in case of submerged graphene fragments in water. A combined effect of attractive dispersion forces, angle correlations between aqueous dipoles, and repulsion due to the hydrogen-bond-induced orientation bias in polarized hydration layers acting across graphene sheet, enhances apparent adhesion of water to graphene. We show wetting free energy of a fully wetted graphene platelet to be about 8 mNm-1 lower than for graphene wetted only on one side, which gives close to 10° reduction in contact angle. This difference has potential implications for predictions of water absorption vs. desorption, phase behavior of water in aqueous nanoconfinements, solvent-induced interactions among graphitic nanoparticle and concomitant stability in aqueous dispersions, and can influence permeability of porous materials such as carbon nanotubes by water and aqueous solutions.

  5. Passivation coating on electrospun copper nanofibers for stable transparent electrodes.

    PubMed

    Hsu, Po-Chun; Wu, Hui; Carney, Thomas J; McDowell, Matthew T; Yang, Yuan; Garnett, Erik C; Li, Michael; Hu, Liangbing; Cui, Yi

    2012-06-26

    Copper nanofiber networks, which possess the advantages of low cost, moderate flexibility, small sheet resistance, and high transmittance, are one of the most promising candidates to replace indium tin oxide films as the premier transparent electrode. However, the chemical activity of copper nanofibers causes a substantial increase in the sheet resistance after thermal oxidation or chemical corrosion of the nanofibers. In this work, we utilize atomic layer deposition to coat a passivation layer of aluminum-doped zinc oxide (AZO) and aluminum oxide onto electrospun copper nanofibers and remarkably enhance their durability. Our AZO-copper nanofibers show resistance increase of remarkably only 10% after thermal oxidation at 160 °C in dry air and 80 °C in humid air with 80% relative humidity, whereas bare copper nanofibers quickly become insulating. In addition, the coating and baking of the acidic PEDOT:PSS layer on our fibers increases the sheet resistance of bare copper nanofibers by 6 orders of magnitude, while the AZO-Cu nanofibers show an 18% increase. PMID:22548313

  6. The art of transparency

    PubMed Central

    Sayim, Bilge; Cavanagh, Patrick

    2011-01-01

    Artists throughout the ages have discovered a number of techniques to depict transparency. With only a few exceptions, these techniques follow closely the properties of physical transparency. The two best known properties are X-junctions and the luminance relations described by Metelli. X-junctions are seen where the contours of a transparent material cross contours of the surface behind; Metelli's constraints on the luminance relations between the direct and filtered portions of the surface specify a range of luminance values that are consistent with transparency. These principles have been used by artists since the time of ancient Egypt. However, artists also discovered that stimuli can be seen as transparent even when these physical constraints are not met. Ancient Greek artists, for example, were able to depict transparent materials in simple black-and-white line drawings. Artists also learned how to represent transparency in cases where neither X-junctions nor Metelli's constraints could apply: for example, where no portions of the objects behind the transparent material extend beyond it. Many painters convincingly portrayed transparency in these cases by depicting the effects the transparent medium would have on material or object properties. Here, we show how artists employed these and other techniques revealing their anticipation of current formalizations of perceived transparency, and we suggest new, as-yet-untested principles. PMID:23145252

  7. The art of transparency.

    PubMed

    Sayim, Bilge; Cavanagh, Patrick

    2011-01-01

    Artists throughout the ages have discovered a number of techniques to depict transparency. With only a few exceptions, these techniques follow closely the properties of physical transparency. The two best known properties are X-junctions and the luminance relations described by Metelli. X-junctions are seen where the contours of a transparent material cross contours of the surface behind; Metelli's constraints on the luminance relations between the direct and filtered portions of the surface specify a range of luminance values that are consistent with transparency. These principles have been used by artists since the time of ancient Egypt. However, artists also discovered that stimuli can be seen as transparent even when these physical constraints are not met. Ancient Greek artists, for example, were able to depict transparent materials in simple black-and-white line drawings. Artists also learned how to represent transparency in cases where neither X-junctions nor Metelli's constraints could apply: for example, where no portions of the objects behind the transparent material extend beyond it. Many painters convincingly portrayed transparency in these cases by depicting the effects the transparent medium would have on material or object properties. Here, we show how artists employed these and other techniques revealing their anticipation of current formalizations of perceived transparency, and we suggest new, as-yet-untested principles. PMID:23145252

  8. Emplacement and inflation of pahoehoe sheet flows: observations and measurements of active lava flows on Kilauea volcano, Hawaii

    USGS Publications Warehouse

    Hon, K.; Kauahikaua, J.; Denlinger, R.; Mackay, K.

    1994-01-01

    Inflated pahoehoe sheet flows have a distinctive horizontal upper surface, which can be several hundred meters across, and are bounded to steep monoclinal uplifts. The inflated sheet flows studied ranged from 1 to 5 m in thickness, but initially propagated as thin sheets of fluid pahoehoe lava, generally 20-30 cm thick. The morphology of the lava as flow advanced is described. Inflated sheet flows from Kilauea and Mauna Loa are morphologically similar to some thick Icelandic and submarine sheet flows, suggesting a similar mechanism of emplacement. -from Authors

  9. Preparation of γ-AlON transparent ceramics by one-step method with high-activity Al2O3 powders

    NASA Astrophysics Data System (ADS)

    Sun, Wenzhou; Chen, Yuhong; Wu, Laner; Jiang, Yong

    2013-06-01

    In this paper, γ-AlON transparent ceramics are fabricated by one-step method—reactived hot-pressuring sintering technology by using as-prepared γ-Al2O3 powder as raw material. And the sintering process is also improved from two aspects: adjusting sintered technique parameters and improving the sintering agents. XRD, SEM, ICP-AES analysis results show that as-prepared γ-Al2O3 powders have advantages of super-fine, high-purity and high-activity so that can meet the requirements of starting material. By adding 1wt% Y2O3 as sintering agent, single-phase γ-AlON transparent ceramic can be fabricated under the optimum technological condition: hot-pressure sintering at 1950°C for 6h, under nitrogen atmosphere. The results from XRD and SEM indicate that the γ-AlON ceramic has high density and fine microstructures with relative density of 99.22%. The test result of IR spectrum show that the ceramic yield the best transmittance of 18.42% at 2.5μm and its transmitting wavelength range extend from 1.5 to 4.5μm.

  10. Electron beam irradiated silver nanowires for a highly transparent heater

    NASA Astrophysics Data System (ADS)

    Hong, Chan-Hwa; Oh, Seung Kyu; Kim, Tae Kyoung; Cha, Yu-Jung; Kwak, Joon Seop; Shin, Jae-Heon; Ju, Byeong-Kwon; Cheong, Woo-Seok

    2015-12-01

    Transparent heaters have attracted increasing attention for their usefulness in vehicle windows, outdoor displays, and periscopes. We present high performance transparent heaters based on Ag nanowires with electron beam irradiation. We obtained an Ag-nanowire thin film with 48 ohm/sq of sheet resistance and 88.8% (substrate included) transmittance at 550 nm after electron beam irradiation for 120 sec. We demonstrate that the electron beam creates nano-soldering at the junctions of the Ag nanowires, which produces lower sheet resistance and improved adhesion of the Ag nanowires. We fabricated a transparent heater with Ag nanowires after electron beam irradiation, and obtained a temperature of 51 °C within 1 min at an applied voltage of 7 V. The presented technique will be useful in a wide range of applications for transparent heaters.

  11. Electron beam irradiated silver nanowires for a highly transparent heater

    PubMed Central

    Hong, Chan-Hwa; Oh, Seung Kyu; Kim, Tae Kyoung; Cha, Yu-Jung; Kwak, Joon Seop; Shin, Jae-Heon; Ju, Byeong-Kwon; Cheong, Woo-Seok

    2015-01-01

    Transparent heaters have attracted increasing attention for their usefulness in vehicle windows, outdoor displays, and periscopes. We present high performance transparent heaters based on Ag nanowires with electron beam irradiation. We obtained an Ag-nanowire thin film with 48 ohm/sq of sheet resistance and 88.8% (substrate included) transmittance at 550 nm after electron beam irradiation for 120 sec. We demonstrate that the electron beam creates nano-soldering at the junctions of the Ag nanowires, which produces lower sheet resistance and improved adhesion of the Ag nanowires. We fabricated a transparent heater with Ag nanowires after electron beam irradiation, and obtained a temperature of 51 °C within 1 min at an applied voltage of 7 V. The presented technique will be useful in a wide range of applications for transparent heaters. PMID:26639760

  12. Use of acrylic sheet molds for elastomeric products

    NASA Technical Reports Server (NTRS)

    Heisman, R. M.; Koerner, A. E.; Messineo, S. M.

    1970-01-01

    Molds constructed of acrylic sheet are more easily machined than metal, are transparent to ensure complete filling during injection, and have smooth surfaces free of contamination. Technique eliminates flashing on molded parts and mold release agents.

  13. Boundary conditions of an active West Antarctic subglacial lake: implications for storage of water beneath the ice sheet

    NASA Astrophysics Data System (ADS)

    Siegert, M. J.; Ross, N.; Corr, H.; Smith, B.; Jordan, T.; Bingham, R. G.; Ferraccioli, F.; Rippin, D. M.; Le Brocq, A.

    2014-01-01

    Repeat-pass ICESat altimetry has revealed 124 discrete surface height changes across the Antarctic Ice Sheet, interpreted to be caused by subglacial lake discharges (surface lowering) and inputs (surface uplift). Few of these active lakes have been confirmed by radio-echo sounding (RES) despite several attempts (notable exceptions are Lake Whillans and three in the Adventure Subglacial Trench). Here we present targeted RES and radar altimeter data from an "active lake" location within the upstream Institute Ice Stream, into which at least 0.12 km3 of water was previously calculated to have flowed between October 2003 and February 2008. We use a series of transects to establish an accurate depiction of the influences of bed topography and ice surface elevation on water storage potential. The location of surface height change is downstream of a subglacial hill on the flank of a distinct topographic hollow, where RES reveals no obvious evidence for deep (> 10 m) water. The regional hydropotential reveals a sink coincident with the surface change, however. Governed by the location of the hydrological sink, basal water will likely "drape" over topography in a manner dissimilar to subglacial lakes where flat strong specular RES reflections are measured. The inability of RES to detect the active lake means that more of the Antarctic ice sheet bed may contain stored water than is currently appreciated. Variation in ice surface elevation data sets leads to significant alteration in calculations of the local flow of basal water indicating the value of, and need for, high-resolution altimetry data in both space and time to establish and characterise subglacial hydrological processes.

  14. Boundary conditions of an active West Antarctic subglacial lake: implications for storage of water beneath the ice sheet

    NASA Astrophysics Data System (ADS)

    Siegert, M. J.; Ross, N.; Corr, H.; Smith, B.; Jordan, T.; Bingham, R.; Ferraccioli, F.; Rippin, D.; Le Brocq, A.

    2013-06-01

    Repeat-pass IceSat altimetry has revealed 124 discrete surface height changes across the Antarctic Ice Sheet, interpreted to be caused by subglacial lake discharges (surface lowering) and inputs (surface uplift). Few of these active lakes have been confirmed by radio-echo sounding (RES) despite several attempts (notable exceptions are Lake Whillans and three in the Adventure Subglacial Trench). Here we present targeted RES and radar altimeter data from an "active lake" location within the upstream Institute Ice Stream, into which 0.12 km3 of water is calculated to have flowed between October 2003 and February 2008. We use a series of transects to establish an accurate appreciation of the influences of bed topography and ice-surface elevation on water storage potential. The location of surface height change is over the downslope flank of a distinct topographic hollow, where RES reveals no obvious evidence for deep (> 10 m) water. The regional hydropotential reveals a sink coincident with the surface change, however. Governed by the location of the hydrological sink, basal water will likely "drape" over existing topography in a manner dissimilar to subglacial lakes where flat strong specular RES reflections are measured. The inability of RES to detect the active lake means that more of the Antarctic ice sheet bed may contain stored water than is currently appreciated. Variation in ice surface elevation datasets leads to significant alteration in calculations of the local flow of basal water indicating the value of, and need for, high resolution RES datasets in both space and time to establish and characterise subglacial hydrological processes.

  15. Web-based Tools for Educators: Outreach Activities of the Polar Radar for Ice Sheet Measurements (PRISM) Project

    NASA Astrophysics Data System (ADS)

    Braaten, D. A.; Holvoet, J. F.; Gogineni, S.

    2003-12-01

    The Radar Systems and Remote Sensing Laboratory at the University of Kansas (KU) has implemented extensive outreach activities focusing on Polar Regions as part of the Polar Radar for Ice Sheet Measurements (PRISM) project. The PRISM project is developing advanced intelligent remote sensing technology that involves radar systems, an autonomous rover, and communications systems to measure detailed ice sheet characteristics, and to determine bed conditions (frozen or wet) below active ice sheets in both Greenland and Antarctica. These measurements will provide a better understanding of the response of polar ice sheets to global climate change and the resulting impact the ice sheets will have on sea level rise. Many of the research and technological development aspects of the PRISM project, such as robotics, radar systems, climate change and exploration of harsh environments, can kindle an excitement and interest in students about science and technology. These topics form the core of our K-12 education and training outreach initiatives, which are designed to capture the imagination of young students, and prompt them to consider an educational path that will lead them to scientific or engineering careers. The K-12 PRISM outreach initiatives are being developed and implemented in a collaboration with the Advanced Learning Technology Program (ALTec) of the High Plains Regional Technology in Education Consortium (HPR*TEC). ALTec is associated with the KU School of Education, and is a well-established educational research center that develops and hosts web tools to enable teachers nationwide to network, collaborate, and share resources with other teachers. An example of an innovative and successful web interface developed by ALTec is called TrackStar. Teachers can use TrackStar over the Web to develop interactive, resource-based lessons (called tracks) on-line for their students. Once developed, tracks are added to the TrackStar database and can be accessed and modified

  16. Feasibility Study of Optically Transparent Microstrip Patch Antenna

    NASA Technical Reports Server (NTRS)

    Simons, Rainee N.; Lee, Richard Q.

    1997-01-01

    The paper presents a feasibility study on optically transparent patch antennas with microstrip line and probe feeds. The two antennas operate at 2.3 GHz and 19.5 GHz respectively. They are constructed from a thin sheet of clear polyester with an AgHT-8 optically transparent conductive coating. The experimental results show good radiation patterns and input impedance match. The antennas have potential applications in mobile wireless communications.

  17. Graphene Transparent Conductive Electrodes for Next- Generation Microshutter Arrays

    NASA Technical Reports Server (NTRS)

    Li, Mary; Sultana, Mahmooda; Hess, Larry

    2012-01-01

    Graphene is a single atomic layer of graphite. It is optically transparent and has high electron mobility, and thus has great potential to make transparent conductive electrodes. This invention contributes towards the development of graphene transparent conductive electrodes for next-generation microshutter arrays. The original design for the electrodes of the next generation of microshutters uses indium-tin-oxide (ITO) as the electrode material. ITO is widely used in NASA flight missions. The optical transparency of ITO is limited, and the material is brittle. Also, ITO has been getting more expensive in recent years. The objective of the invention is to develop a graphene transparent conductive electrode that will replace ITO. An exfoliation procedure was developed to make graphene out of graphite crystals. In addition, large areas of single-layer graphene were produced using low-pressure chemical vapor deposition (LPCVD) with high optical transparency. A special graphene transport procedure was developed for transferring graphene from copper substrates to arbitrary substrates. The concept is to grow large-size graphene sheets using the LPCVD system through chemical reaction, transfer the graphene film to a substrate, dope graphene to reduce the sheet resistance, and pattern the film to the dimension of the electrodes in the microshutter array. Graphene transparent conductive electrodes are expected to have a transparency of 97.7%. This covers the electromagnetic spectrum from UV to IR. In comparison, ITO electrodes currently used in microshutter arrays have 85% transparency in mid-IR, and suffer from dramatic transparency drop at a wavelength of near-IR or shorter. Thus, graphene also has potential application as transparent conductive electrodes for Schottky photodiodes in the UV region.

  18. Effect of material flow on joint strength in activation spot joining of Al alloy and steel sheets

    NASA Astrophysics Data System (ADS)

    Watanabe, Goro; Yogo, Yasuhiro; Takao, Hisaaki

    2014-08-01

    A new joining method for dissimilar metal sheets was developed where a rotated consumable rod of Al alloy is pressed onto an Al alloy sheet at the part overlapped with a mild steel sheet. The metal flow in the joining region is increased by the through-hole in the Al sheet and consumable Al rod. The rod creates the joint interface and pads out of the thinly joined parts through pressing. This produces a higher joint strength than that of conventional friction stir spot welding. Measurements of the joint interface showed the presence of a 5-10 nm thick amorphous layer consisting of Al and Mg oxides.

  19. Organic devices based on nickel nanowires transparent electrode

    PubMed Central

    Kim, Jeongmo; da Silva, Wilson Jose; bin Mohd Yusoff, Abd. Rashid; Jang, Jin

    2016-01-01

    Herein, we demonstrate a facile approach to synthesize long nickel nanowires and discuss its suitability to replace our commonly used transparent electrode, indium-tin-oxide (ITO), by a hydrazine hydrate reduction method where nickel ions are reduced to nickel atoms in an alkaline solution. The highly purified nickel nanowires show high transparency within the visible region, although the sheet resistance is slightly larger compared to that of our frequently used transparent electrode, ITO. A comparison study on organic light emitting diodes and organic solar cells, using commercially available ITO, silver nanowires, and nickel nanowires, are also discussed. PMID:26804335

  20. Organic devices based on nickel nanowires transparent electrode

    NASA Astrophysics Data System (ADS)

    Kim, Jeongmo; da Silva, Wilson Jose; Bin Mohd Yusoff, Abd. Rashid; Jang, Jin

    2016-01-01

    Herein, we demonstrate a facile approach to synthesize long nickel nanowires and discuss its suitability to replace our commonly used transparent electrode, indium-tin-oxide (ITO), by a hydrazine hydrate reduction method where nickel ions are reduced to nickel atoms in an alkaline solution. The highly purified nickel nanowires show high transparency within the visible region, although the sheet resistance is slightly larger compared to that of our frequently used transparent electrode, ITO. A comparison study on organic light emitting diodes and organic solar cells, using commercially available ITO, silver nanowires, and nickel nanowires, are also discussed.

  1. Optically Transparent Microwave Polarizer Based On Quasi-Metallic Graphene.

    PubMed

    Grande, Marco; Bianco, Giuseppe Valerio; Vincenti, Maria Antonietta; de Ceglia, Domenico; Capezzuto, Pio; Scalora, Michael; D'Orazio, Antonella; Bruno, Giovanni

    2015-01-01

    In this paper, we report on the engineering and the realization of optically transparent graphene-based microwave devices using Chemical Vapour Deposition (CVD) graphene whose sheet resistance may be tailored down to values below 30 Ω/sq. In particular, we show that the process was successfully used to realize and characterize a simple, optically transparent graphene-based wire-grid polarizer at microwave frequencies (X band). The availability of graphene operating in a quasi-metallic region may allow the integration of graphene layers in several microwave components, thus leading to the realization of fully transparent (and flexible) microwave devices. PMID:26603112

  2. Optically Transparent Microwave Polarizer Based On Quasi-Metallic Graphene

    PubMed Central

    Grande, Marco; Bianco, Giuseppe Valerio; Vincenti, Maria Antonietta; de Ceglia, Domenico; Capezzuto, Pio; Scalora, Michael; D’Orazio, Antonella; Bruno, Giovanni

    2015-01-01

    In this paper, we report on the engineering and the realization of optically transparent graphene-based microwave devices using Chemical Vapour Deposition (CVD) graphene whose sheet resistance may be tailored down to values below 30 Ω/sq. In particular, we show that the process was successfully used to realize and characterize a simple, optically transparent graphene-based wire-grid polarizer at microwave frequencies (X band). The availability of graphene operating in a quasi-metallic region may allow the integration of graphene layers in several microwave components, thus leading to the realization of fully transparent (and flexible) microwave devices. PMID:26603112

  3. Graphene versus oxides for transparent electrode applications

    NASA Astrophysics Data System (ADS)

    Sandana, V. E.; Rogers, D. J.; Teherani, F. Hosseini; Bove, P.; Razeghi, M.

    2013-03-01

    Due to their combination of good electrical conductivity and optical transparency, Transparent Conducting Oxides (TCOs) are the most common choice as transparent electrodes for optoelectronics applications. In particular, devices, such as LEDs, LCDs, touch screens and solar cells typically employ indium tin oxide. However, indium has some significant drawbacks, including toxicity issues (which are hampering manufacturing), an increasing rarefication (due to a combination of relative scarcity and increasing demand [1]) and resulting price increases. Moreover, there is no satisfactory option at the moment for use as a p-type transparent contact. Thus alternative materials solutions are actively being sought. This review will compare the performance and perspectives of graphene with respect to TCOs for use in transparent conductor applications.

  4. Casimir forces and graphene sheets

    SciTech Connect

    Drosdoff, D.; Woods, Lilia M.

    2010-10-15

    The Casimir force between two infinitely thin parallel sheets in a setting of N such sheets is found. The finite two-dimensional conductivities, which describe the dispersive and absorptive properties of each sheet, are taken into account, whereupon the theory is applied to interacting graphenes. By exploring similarities with in-plane optical spectra for graphite, the conductivity of graphene is modeled as a combination of Lorentz-type oscillators. We find that the graphene transparency and the existence of a universal constant conductivity e{sup 2}/(4({h_bar}/2{pi})) result in the graphene/graphene Casimir interaction at large separations to have the same distance dependence as the one for perfect conductors but with much smaller magnitude. The Casimir force is also studied when the graphene system is above a substrate or immersed in a medium. It is found that the response properties of the environmental materials can strongly affect the graphene interaction.

  5. Evidence for Subglacial Volcanic Activity Beneath the area of the Divide of the West Antarctic Ice Sheet

    NASA Astrophysics Data System (ADS)

    Behrendt, J. C.

    2013-12-01

    There is an increasing body of aeromagnetic, radar ice-sounding, heat flow, subglacial volcanic earthquakes, several exposed active and subglacial volcanoes and other lines of evidence for volcanic activity associated with the West Antarctic Rift System (WR) since the origin (~25 Ma) of the West Antarctic Ice Sheet (WAIS), which flows through it. Exposed late Cenozoic, alkaline volcanic rocks, 34 Ma to present concentrated in Marie Byrd Land (LeMasurier and Thomson, 1990), but also exposed along the rift shoulder on the Transantarctic Mountains flank of the WR, and >1 million cubic kilometers, of mostly subglacially erupted 'volcanic centers' beneath the WAIS inferred from aeromagnetic data, have been interpreted as evidence of a magmatic plume. About 18 high relief, (~600-2000 m) 'volcanic centers' presently beneath the WAIS surface, probably were erupted subaerially when the WAIS was absent, based on the 5-km orthogonally line spaced Central West Antarctica aerogeophysical survey. All would be above sea level after ice removal and isostatic adjustment. Nine of these high relief peaks are in the general area beneath the divide of the WAIS. This high bed relief topography was first interpreted in the 1980s as the volcanic 'Sinuous Ridge ' based on a widely spaced aeromagnetic -radar ice sounding survey (Jankowski et al,. 1983). A 70-km wide, circular ring of interpreted subglacial volcanic rocks was cited as evidence of a volcanic caldera underlying the ice sheet divide based on the CWA survey (Behrendt et al., 1998). A broad magnetic 'low' surrounding the caldera area possibly is evidence of a shallow Curie isotherm. High heat flow reported from temperature logging (Clow et al., 2012) in the WAISCORE and a thick volcanic ash layer in the core (Dunbar et al., 2012) are consistent with this interpretation. A 2 km-high subaerially erupted volcano (subglacial Mt Thiel, ~78.5 degrees S, 111 degrees W) ~ 100 km north from the WAISCORE could be the source of the ash

  6. Different bulk and active bacterial communities in cryoconite from the margin and interior of the Greenland ice sheet.

    PubMed

    Stibal, Marek; Schostag, Morten; Cameron, Karen A; Hansen, Lars H; Chandler, David M; Wadham, Jemma L; Jacobsen, Carsten S

    2015-04-01

    Biological processes in the supraglacial ecosystem, including cryoconite, contribute to nutrient cycling within the cryosphere and may affect surface melting, yet little is known of the diversity of the active microbes in these environments. We examined the bacterial abundance and community composition of cryoconite over a melt season at two contrasting sites at the margin and in the interior of the Greenland ice sheet, using sequence analysis and quantitative polymerase chain reaction of coextracted 16S rDNA and rRNA. Significant differences were found between bulk (rDNA) and potentially active (rRNA) communities, and between communities sampled from the two sites. Higher concentrations of rRNA than rDNA were detected at the interior site, whereas at the margin several orders of magnitude less rRNA was found compared with rDNA, which may be explained by a lower proportion of active bacteria at the margin site. The rRNA communities at both sites were dominated by a few taxa of Cyanobacteria and Alpha- and/or Betaproteobacteria. The bulk alpha diversity was higher in the margin site community, suggesting that local sources may be contributing towards the gene pool in addition to long distance transport. PMID:25405749

  7. Printed optically transparent graphene cellulose electrodes

    NASA Astrophysics Data System (ADS)

    Sinar, Dogan; Knopf, George K.; Nikumb, Suwas; Andrushchenko, Anatoly

    2016-02-01

    Optically transparent electrodes are a key component in variety of products including bioelectronics, touch screens, flexible displays, low emissivity windows, and photovoltaic cells. Although highly conductive indium tin oxide (ITO) films are often used in these electrode applications, the raw material is very expensive and the electrodes often fracture when mechanically stressed. An alternative low-cost material for inkjet printing transparent electrodes on glass and flexible polymer substrates is described in this paper. The water based ink is created by using a hydrophilic cellulose derivative, carboxymethyl cellulose (CMC), to help suspend the naturally hydrophobic graphene (G) sheets in a solvent composed of 70% DI water and 30% 2-butoxyethanol. The CMC chain has hydrophobic and hydrophilic functional sites which allow adsorption on G sheets and, therefore, permit the graphene to be stabilized in water by electrostatic and steric forces. Once deposited on the functionalized substrate the electrical conductivity of the printed films can be "tuned" by decomposing the cellulose stabilizer using thermal reduction. The entire electrode can be thermally reduced in an oven or portions of the electrode thermally modified using a laser annealing process. The thermal process can reduce the sheet resistance of G-CMC films to < 100 Ω/sq. Experimental studies show that the optical transmittance and sheet resistance of the G-CMC conductive electrode is a dependent on the film thickness (ie. superimposed printed layers). The printed electrodes have also been doped with AuCl3 to increase electrical conductivity without significantly increasing film thickness and, thereby, maintain high optical transparency.

  8. Coos County Youth and Out-of-School Activities: Patterns of Involvement and Barriers to Participation. New England Fact Sheet No. 7, Fall 2012

    ERIC Educational Resources Information Center

    Sharp, Erin Hiley

    2012-01-01

    This fact sheet draws from surveys administered to a cohort of 416 participants in 7th grade in 2008, again when they were in 8th grade in 2009, and most recently as 10th graders in 2011 to look at patterns of participation in structured activities over time and whether male and female students differ in these patterns of participation. It also…

  9. Transparencies and Reflections.

    ERIC Educational Resources Information Center

    Hubbard, Guy

    1999-01-01

    Discusses the use of perspective, or showing things as the human eye sees them, when creating reflections and transparencies in works of art. Provides examples of artwork using transparency, reflection, and refraction by M. C. Escher, Richard Estes, and Janet Fish to give students an opportunity to learn about these three art techniques. (CMK)

  10. Family Life Education Transparencies.

    ERIC Educational Resources Information Center

    Clemson Univ., SC. Vocational Education Media Center.

    This compilation of thirty-three transparencies, a supplement to the family life education curriculum guide (see related note), is designed for use by secondary education home economics teachers in teaching family life education classes. The transparencies, covering three areas in family life education, each consist of a captioned picture…

  11. NREL Team Creates High-Activity, Durable Platinum Extended Surface Catalyst for Fuel Cells (Fact Sheet)

    SciTech Connect

    Not Available

    2011-02-01

    Researchers with NREL's Fuel Cell team showed that platinum can replace copper nanowires in such a way that high-surface-area and high-specific-activity catalysts are produced, potentially allowing for lower-cost catalysts.

  12. Improved thermal oxidation stability of solution-processable silver nanowire transparent electrode by reduced graphene oxide.

    PubMed

    Ahn, Yumi; Jeong, Youngjun; Lee, Youngu

    2012-12-01

    Solution-processable silver nanowire-reduced graphene oxide (AgNW-rGO) hybrid transparent electrode was prepared in order to replace conventional ITO transparent electrode. AgNW-rGO hybrid transparent electrode exhibited high optical transmittance and low sheet resistance, which is comparable to ITO transparent electrode. In addition, it was found that AgNW-rGO hybrid transparent electrode exhibited highly enhanced thermal oxidation and chemical stabilities due to excellent gas-barrier property of rGO passivation layer onto AgNW film. Furthermore, the organic solar cells with AgNW-rGO hybrid transparent electrode showed good photovoltaic behavior as much as solar cells with AgNW transparent electrode. It is expected that AgNW-rGO hybrid transparent electrode can be used as a key component in various optoelectronic application such as display panels, touch screen panels, and solar cells. PMID:23206541

  13. The adaptor protein Cindr regulates JNK activity to maintain epithelial sheet integrity.

    PubMed

    Yasin, Hannah W R; van Rensburg, Samuel H; Feiler, Christina E; Johnson, Ruth I

    2016-02-15

    Epithelia are essential barrier tissues that must be appropriately maintained for their correct function. To achieve this a plethora of protein interactions regulate epithelial cell number, structure and adhesion, and differentiation. Here we show that Cindr (the Drosophila Cin85 and Cd2ap ortholog) is required to maintain epithelial integrity. Reducing Cindr triggered cell delamination and movement. Most delaminating cells died. These behaviors were consistent with JNK activation previously associated with loss of epithelial integrity in response to ectopic oncogene activity. We confirmed a novel interaction between Cindr and Drosophila JNK (dJNK), which when perturbed caused inappropriate JNK signaling. Genetically reducing JNK signaling activity suppressed the effects of reducing Cindr. Furthermore, ectopic JNK signaling phenocopied loss of Cindr and was partially rescued by concomitant cindr over-expression. Thus, correct Cindr-dJNK stoichiometry is essential to maintain epithelial integrity and disturbing this balance may contribute to the pathogenesis of disease states, including cancer. PMID:26772997

  14. The Marfan Syndrome. Fact Sheet [and] Physical Education and Activity Guidelines.

    ERIC Educational Resources Information Center

    National Marfan Foundation, Port Washington, NY.

    This document consists of two brochures, the first explaining the Marfan Syndrome and a second providing guidelines for physical education and activity for people who have this syndrome are provided. The brochure on factual information about Marfan syndrome outlines the associated medical problems involving the cardiovascular system, the skeleton,…

  15. Design and biological activity of {beta}-sheet breaker peptide conjugates

    SciTech Connect

    Rocha, Sandra Cardoso, Isabel; Boerner, Hans; Pereira, Maria Carmo; Saraiva, Maria Joao; Coelho, Manuel

    2009-03-06

    The sequence LPFFD (iA{beta}{sub 5}) prevents amyloid-{beta} peptide (A{beta}) fibrillogenesis and neurotoxicity, hallmarks of Alzheimer's disease (AD), as previously demonstrated. In this study iA{beta}{sub 5} was covalently linked to poly(ethylene glycol) (PEG) and the activity of conjugates was assessed and compared to the activity of the peptide alone by in vitro studies. The conjugates were characterized by MALDI-TOF. Competition binding assays established that conjugates retained the ability to bind A{beta} with similar strength as iA{beta}{sub 5}. Transmission electron microscopy analysis showed that iA{beta}{sub 5} conjugates inhibited amyloid fibril formation, which is in agreement with binding properties observed for the conjugates towards A{beta}. The conjugates were also able to prevent amyloid-induced cell death, as evaluated by activation of caspase 3. These results demonstrated that the biological activity of iA{beta}{sub 5} is not affected by the pegylation process.

  16. Dental Charting. Learning Activities, Unit Tests, Progress Chart, and Work Sheet.

    ERIC Educational Resources Information Center

    Texas Univ., Austin. Center for Occupational Curriculum Development.

    These materials are part of a series dealing with skills and information needed by students in dental assisting. The individualized student materials are suitable for classroom, laboratory, or cooperative training programs. These student materials, designed to be used with the Dental Charting Student Manual, consist of learning activities, unit…

  17. Versatile MoS2 Nanosheets in ITO-Free and Semi-transparent Polymer Power-generating Glass

    PubMed Central

    Hu, Xiaotian; Chen, Lie; Tan, Licheng; Zhang, Yong; Hu, Lin; Xie, Bing; Chen, Yiwang

    2015-01-01

    Chemical exfoliated ultra-thin MoS2 nanosheets (NSs) with well 2D structure were demonstrated for interfacial layers and Ag nanowires composite transparent electrode in polymer solar cells (PSCs). The smooth and uniform n-type and p-type (after the plasma treatment) MoS2 NSs could improve fill factor of devices and light absorption in active layer. The optimized Ag nanowires–MoS2 NSs (AgNW-MoS2 NSs) transparent electrode presented a low sheet resistance of 9.8 Ω sq−1, and the corresponding transmittance also exhibited a high value of 93.1% at 550 nm. As a result, ITO-free PSCs based on AgNW-MoS2 NSs/n-MoS2 NSs cathode and p-MoS2 NSs/Ag anode achieved a highest PCE of 8.72%. Furthermore, a high efficiency (6.55%), large area and low cost semi-transparent power-generating glass was obtained, after reducing the thickness of top Ag electrode from 100 nm to 30 nm. To our best knowledge, it is the highest performance for semi-transparent PSCs devices reported up to now. The novel semi-transparent power-generating glass showed good performance and color purity for commercial applications in the near future. PMID:26177887

  18. Versatile MoS2 Nanosheets in ITO-Free and Semi-transparent Polymer Power-generating Glass

    NASA Astrophysics Data System (ADS)

    Hu, Xiaotian; Chen, Lie; Tan, Licheng; Zhang, Yong; Hu, Lin; Xie, Bing; Chen, Yiwang

    2015-07-01

    Chemical exfoliated ultra-thin MoS2 nanosheets (NSs) with well 2D structure were demonstrated for interfacial layers and Ag nanowires composite transparent electrode in polymer solar cells (PSCs). The smooth and uniform n-type and p-type (after the plasma treatment) MoS2 NSs could improve fill factor of devices and light absorption in active layer. The optimized Ag nanowires-MoS2 NSs (AgNW-MoS2 NSs) transparent electrode presented a low sheet resistance of 9.8 Ω sq-1, and the corresponding transmittance also exhibited a high value of 93.1% at 550 nm. As a result, ITO-free PSCs based on AgNW-MoS2 NSs/n-MoS2 NSs cathode and p-MoS2 NSs/Ag anode achieved a highest PCE of 8.72%. Furthermore, a high efficiency (6.55%), large area and low cost semi-transparent power-generating glass was obtained, after reducing the thickness of top Ag electrode from 100 nm to 30 nm. To our best knowledge, it is the highest performance for semi-transparent PSCs devices reported up to now. The novel semi-transparent power-generating glass showed good performance and color purity for commercial applications in the near future.

  19. Transparent electrode for optical switch

    DOEpatents

    Goldhar, J.; Henesian, M.A.

    1984-10-19

    The invention relates generally to optical switches and techniques for applying a voltage to an electro-optical crystal, and more particularly, to transparent electodes for an optical switch. System architectures for very large inertial confinement fusion (ICF) lasers require active optical elements with apertures on the order of one meter. Large aperture optical switches are needed for isolation of stages, switch-out from regenerative amplifier cavities and protection from target retroreflections.

  20. Transparent conducting thin films for spacecraft applications

    NASA Technical Reports Server (NTRS)

    Perez-Davis, Marla E.; Malave-Sanabria, Tania; Hambourger, Paul; Rutledge, Sharon K.; Roig, David; Degroh, Kim K.; Hung, Ching-Cheh

    1994-01-01

    Transparent conductive thin films are required for a variety of optoelectronic applications: automotive and aircraft windows, and solar cells for space applications. Transparent conductive coatings of indium-tin-oxide (ITO)-magnesium fluoride (MgF2) and aluminum doped zinc oxide (AZO) at several dopant levels are investigated for electrical resistivity (sheet resistance), carrier concentration, optical properties, and atomic oxygen durability. The sheet resistance values of ITO-MgF2 range from 10(exp 2) to 10(exp 11) ohms/square, with transmittance of 75 to 86 percent. The AZO films sheet resistances range from 10(exp 7) to 10(exp 11) ohms/square with transmittances from 84 to 91 percent. It was found that in general, with respect to the optical properties, the zinc oxide (ZnO), AZO, and the high MgF2 content ITO-MgF2 samples, were all durable to atomic oxygen plasma, while the low MgF2 content of ITO-MgF2 samples were not durable to atomic oxygen plasma exposure.

  1. Highly compliant transparent electrodes

    NASA Astrophysics Data System (ADS)

    Shian, Samuel; Diebold, Roger M.; McNamara, Alena; Clarke, David R.

    2012-08-01

    Adaptive optical devices based on electric field induced deformation of dielectric elastomers require transparent and highly compliant electrodes to conform to large shape changes. Electrical, optical, and actuation properties of acrylic elastomer electrodes fabricated with single-walled carbon nanotubes (SWCNTs) and silver nanowires (AgNWs) have been evaluated. Based on these properties, a figure of merit is introduced for evaluating the overall performance of deformable transparent electrodes. This clearly indicates that SWCNTs outperform AgNWs. Under optimal conditions, optical transparency as high as 91% at 190% maximum actuation strain is readily achievable using SWCNT electrodes.

  2. Toward transparent clinical policies.

    PubMed

    Shiffman, Richard N; Marcuse, Edgar K; Moyer, Virginia A; Neuspiel, Daniel R; Hodgson, Elizabeth Susan; Glade, Gordon; Harbaugh, Norman; Miller, Marlene R; Sevilla, Xavier; Simpson, Lisa; Takata, Glenn

    2008-03-01

    Clinical policies of professional societies such as the American Academy of Pediatrics are valued highly, not only by clinicians who provide direct health care to children but also by many others who rely on the professional expertise of these organizations, including parents, employers, insurers, and legislators. The utility of a policy depends, in large part, on the degree to which its purpose and basis are clear to policy users, an attribute known as the policy's transparency. This statement describes the critical importance and special value of transparency in clinical policies, guidelines, and recommendations; helps identify obstacles to achieving transparency; and suggests several approaches to overcome these obstacles. PMID:18310217

  3. Nanocarbonic transparent conductive films.

    PubMed

    Roth, Siegmar; Park, Hye Jin

    2010-07-01

    This tutorial review discusses the contradictory material properties of electrical conductivity and optical transparency for the examples of graphene films and carbon nanotube networks. It is argued that for homogeneous films both properties are linked by basic laws of physics and that for perfect monoatomic layers conductivity and transparency can be calculated from the fine structure constant. To beat these limitations, inhomogeneous films are required, such as graphene with an array of holes or nanotube networks. An overview is given on literature values of transparency and conductivity, both for graphene films and for nanotube networks. PMID:20502813

  4. A Dictionary for Transparency

    SciTech Connect

    Kouzes, Richard T.

    2001-11-15

    There are many terms that are used in association with the U.S. Defense Threat Reduction Agency (DTRA) Transparency Project associated with the Mayak Fissile Materials Storage Facility. This is a collection of proposed definitions of these terms.

  5. The road to transparency.

    PubMed

    Meyers, Susan

    2005-05-01

    A growing number of hospitals are putting transparency at the forefront of their strategic agendas, seeing it not only as the key to better performance, but as an important tool for improving community trust. PMID:15926296

  6. Copper nanowires as fully transparent conductive electrodes.

    PubMed

    Guo, Huizhang; Lin, Na; Chen, Yuanzhi; Wang, Zhenwei; Xie, Qingshui; Zheng, Tongchang; Gao, Na; Li, Shuping; Kang, Junyong; Cai, Duanjun; Peng, Dong-Liang

    2013-01-01

    In pondering of new promising transparent conductors to replace the cost rising tin-doped indium oxide (ITO), metal nanowires have been widely concerned. Herein, we demonstrate an approach for successful synthesis of long and fine Cu nanowires (NWs) through a novel catalytic scheme involving nickel ions. Such Cu NWs in high aspect ratio (diameter of 16.2 ± 2 nm and length up to 40 μm) provide long distance for electron transport and, meanwhile, large space for light transmission. Transparent electrodes fabricated using the Cu NW ink achieve a low sheet resistance of 1.4 Ohm/sq at 14% transmittance and a high transparency of 93.1% at 51.5 Ohm/sq. The flexibility and stability were tested with 100-timebending by 180°and no resistance change occurred. Ohmic contact was achieved to the p- and n-GaN on blue light emitting diode chip and bright electroluminescence from the front face confirmed the excellent transparency. PMID:23900572

  7. Copper Nanowires as Fully Transparent Conductive Electrodes

    NASA Astrophysics Data System (ADS)

    Guo, Huizhang; Lin, Na; Chen, Yuanzhi; Wang, Zhenwei; Xie, Qingshui; Zheng, Tongchang; Gao, Na; Li, Shuping; Kang, Junyong; Cai, Duanjun; Peng, Dong-Liang

    2013-07-01

    In pondering of new promising transparent conductors to replace the cost rising tin-doped indium oxide (ITO), metal nanowires have been widely concerned. Herein, we demonstrate an approach for successful synthesis of long and fine Cu nanowires (NWs) through a novel catalytic scheme involving nickel ions. Such Cu NWs in high aspect ratio (diameter of 16.2 +/- 2 nm and length up to 40 μm) provide long distance for electron transport and, meanwhile, large space for light transmission. Transparent electrodes fabricated using the Cu NW ink achieve a low sheet resistance of 1.4 Ohm/sq at 14% transmittance and a high transparency of 93.1% at 51.5 Ohm/sq. The flexibility and stability were tested with 100-timebending by 180°and no resistance change occurred. Ohmic contact was achieved to the p- and n-GaN on blue light emitting diode chip and bright electroluminescence from the front face confirmed the excellent transparency.

  8. Copper Nanowires as Fully Transparent Conductive Electrodes

    PubMed Central

    Guo, Huizhang; Lin, Na; Chen, Yuanzhi; Wang, Zhenwei; Xie, Qingshui; Zheng, Tongchang; Gao, Na; Li, Shuping; Kang, Junyong; Cai, Duanjun; Peng, Dong-Liang

    2013-01-01

    In pondering of new promising transparent conductors to replace the cost rising tin-doped indium oxide (ITO), metal nanowires have been widely concerned. Herein, we demonstrate an approach for successful synthesis of long and fine Cu nanowires (NWs) through a novel catalytic scheme involving nickel ions. Such Cu NWs in high aspect ratio (diameter of 16.2 ± 2 nm and length up to 40 μm) provide long distance for electron transport and, meanwhile, large space for light transmission. Transparent electrodes fabricated using the Cu NW ink achieve a low sheet resistance of 1.4 Ohm/sq at 14% transmittance and a high transparency of 93.1% at 51.5 Ohm/sq. The flexibility and stability were tested with 100-timebending by 180°and no resistance change occurred. Ohmic contact was achieved to the p- and n-GaN on blue light emitting diode chip and bright electroluminescence from the front face confirmed the excellent transparency. PMID:23900572

  9. Transparent Aluminium Oxide Coatings of Polymer Brushes.

    PubMed

    Micciulla, Samantha; Duan, XiaoFei; Strebe, Julia; Löhmann, Oliver; Lamb, Robert N; von Klitzing, Regine

    2016-04-11

    A novel method for the preparation of transparent Al2 O3 coatings of polymers is presented. An environmental-friendly sol-gel method is employed, which implies mild conditions and low costs. A thermoresponsive brush is chosen as a model surface. X-ray photoelectron spectroscopy is used to characterize the samples during the conversion of the precursor Al(OH)3 into oxide and to prove the mildness of the protocol. The study evidences a relation between lateral homogeneity of alumina and the wettability of the polymer surface by the precursor solution, while morphology and elasticity are dominated by the polymer properties. The study of the swelling behavior of the underneath brush reveals the absence of water uptake, proving the impermeability of the alumina layer. The broad chemical and structural variety of polymers, combined with the robustness of transparent alumina films, makes these composites promising as biomedical implants, protective sheets and components for electric and optical devices. PMID:26991543

  10. Transparent and Flexible Large-scale Graphene-based Heater

    NASA Astrophysics Data System (ADS)

    Kang, Junmo; Lee, Changgu; Kim, Young-Jin; Choi, Jae-Boong; Hong, Byung Hee

    2011-03-01

    We report the application of transparent and flexible heater with high optical transmittance and low sheet resistance using graphene films, showing outstanding thermal and electrical properties. The large-scale graphene films were grown on Cu foil by chemical vapor deposition methods, and transferred to transparent substrates by multiple stacking. The wet chemical doping process enhanced the electrical properties, showing a sheet resistance as low as 35 ohm/sq with 88.5 % transmittance. The temperature response usually depends on the dimension and the sheet resistance of the graphene-based heater. We show that a 4x4 cm2 heater can reach 80& circ; C within 40 seconds and large-scale (9x9 cm2) heater shows uniformly heating performance, which was measured using thermocouple and infra-red camera. These heaters would be very useful for defogging systems and smart windows.

  11. Activation of glycerol metabolism in Xanthomonas campestris by adaptive evolution to produce a high-transparency and low-viscosity xanthan gum from glycerol.

    PubMed

    Wang, Zichao; Wu, Jianrong; Zhu, Li; Zhan, Xiaobei

    2016-07-01

    Many studies have focused on using crude glycerol from biodiesel to obtain valuable products, but few of these studies have focused on obtaining polysaccharides. A mutant strain of Xanthomonas campestris CCTCC M2015714 that could use glycerol to produce high-transparency and low-viscosity xanthan gum was obtained by adaptive evolution, and the yield of xanthan gum reached 11.0g/L. We found that transcriptional levels of genes related to glycerol metabolism (glpF, glpK, glpD, and fbp) in the mutant strain were all higher than those from the parent strain. Using 5g/L sucrose or glucose as starter substrate, cell growth time decreased from 36h to 24h and xanthan gum yield increased. Moreover, the mutant strain can tolerate high titer glycerol, and its activity was not affected by the impurities in crude glycerol. All these results proved that crude glycerol from biodiesel industries can be used for xanthan gum production. PMID:27030959

  12. Atmospheric-Pressure Processed Silver Nanowire (Ag-NW)/ZnO Composite Transparent Conducting Contacts

    SciTech Connect

    Perkins, John D.; Aggarwal, Shruti; van Hest, Maikel F. A. M.; Ginley, David S.

    2015-06-14

    Composite transparent contacts (TCs) based on metal nanowires and metal oxide matrix materials hold great promise for high performance transparent contacts for photovoltaics and opto-electronic technologies with the potential of all-atmospheric pressure processing. The metal nanowire mesh can provide both electrical conductivity and mechanical robustness against bending while the matrix material can both control the electrical interface and protect the metal nanowires. Here, we demonstrate all atmospheric pressure processed Ag-NW/ZnO composite TCs that are 90% transparent in the visible with sheet resistance Rs ~= 10 Ohms/sq. In addition, the composite TCs have higher infrared transmission than conventional TCO films with the same sheet resistance.

  13. Electrospinning Directly Synthesized Porous TiO2 Nanofibers Modified by Graphitic Carbon Nitride Sheets for Enhanced Photocatalytic Degradation Activity under Solar Light Irradiation.

    PubMed

    Adhikari, Surya Prasad; Awasthi, Ganesh Prasad; Kim, Han Joo; Park, Chan Hee; Kim, Cheol Sang

    2016-06-21

    We report a direct approach to the fabrication of a composite made of porous TiO2 nanofibers (NFs) and graphitic carbon nitride (g-C3N4) sheets, by means of an angled two-nozzle electrospinning combined with calcination process. Different wt % amounts of g-C3N4 particles in a polymer solution from one nozzle and TiO2 precursors containing the same polymer solution from another nozzle were electrospun and deposited on the collector. Structural characterizations confirm a well-defined morphology of the TiO2/g-C3N4 composite in which the TiO2 NFs are uniformly attached on the g-C3N4 sheet. This proper attachment of TiO2 NFs on the g-C3N4 sheets occurred during calcination. The prepared composites showed the enhanced photocatalytic activity over the photodegradation of rhodamine B and reactive black 5 under natural sunlight. Here, the synergistic effect between the g-C3N4 sheets and the TiO2 NFs having anisotropic properties enhanced the photogenerated electron-hole pair separation and migration, which was confirmed by the measurement of photoluminescence spectra, cyclic voltammograms, and electrochemical impedance spectra. The direct synthesis approach that is established here for such kinds of sheetlike structure and porous NFs composites could provide new insights for the design of high-performance energy conversion catalysts. PMID:27254544

  14. Self-enhanced catalytic activities of functionalized graphene sheets in the combustion of nitromethane: molecular dynamic simulations by molecular reactive force field.

    PubMed

    Zhang, Chaoyang; Wen, Yushi; Xue, Xianggui

    2014-08-13

    Functionalized graphene sheet (FGS) is a promising additive that enhances fuel/propellant combustion, and the determination of its mechanism has attracted much interest. In the present study, a series of molecular dynamic simulations based on a reactive force field (ReaxFF) are performed to explore the catalytic activity (CA) of FGS in the thermal decay of nitromethane (NM, CH3NO2). FGSs and pristine graphene sheets (GSs) are oxidized in hot NM liquid to increase their functionalities and subsequently show self-enhanced CAs during the decay. The CAs result from the interatomic exchanges between the functional groups on the sheets and the NM liquid, i.e., mainly between H and O atoms. CA is dependent on the density of NM, functionalities of sheets, and temperature. The GSs and FGSs that originally exhibit different functionalities tend to possess similar functionalities and consequently similar CAs as temperature increases. Other carbon materials and their oxides can accelerate combustion of other fuels/propellants similar to NM, provided that they can be dispersed and their key reaction steps in combustion are similar to NM. PMID:25055727

  15. Development of a transparent, non-cytotoxic, silver ion-exchanged glass with antimicrobial activity and low ion elution.

    PubMed

    Shim, Gyu-In; Kim, Seong-Hwan; Eom, Hyung-Woo; Kim, Kwang-Mahn; Choi, Se-Young

    2015-05-01

    We investigated the antimicrobial, cytotoxicity, skin irritation, and ion elution behaviors of glass doped with silver ions with respect to its application to electronic equipment such as phones and tablet screens. The microbes tested were Escherichia coli, Staphylococcus aureus, and Penicillium funiculosum. AgNO3 powder was spread on both sides of aluminosilicate glass, and it was heated to 250-280°C for 10min. Under optimized heating conditions (260°C, 10min), the antimicrobial activity of ion-exchanged glass against bacteria and fungi was over 99.9% after 24 weeks. The glass failed to irritate the skin of experimental animals and was considered non-cytotoxic. The maximum amount of Ag ions that were eluted from the ion-exchanged glass into drinking water was measured at 0.037±0.003μgL(-1), an amount which is several orders of magnitude below the standard limit of 0.1mgL(-1) in drinking water. Ag ion-exchanged glass had characteristics suitable for use as a display screen, such as a light transmittance of 90% and a surface roughness of 0.704nm. Our findings suggest that glass doped with silver ions is more hygienic than non-doped glass is, and should be applied to display screens and glassware. PMID:25837509

  16. High figure-of-merit ultrathin metal transparent electrodes incorporating a conductive grid

    SciTech Connect

    Ghosh, D. S.; Chen, T. L.; Pruneri, V.

    2010-01-25

    It is known that ultrathin (<10 nm) metal films (UTMFs) can achieve high level of optical transparency at the expense of the electrical sheet resistance. In this letter, we propose a design, the incorporation of an ad hoc conductive grid, which can significantly reduce the sheet resistance of UTMF based transparent electrodes, leaving practically unchanged their transparency. The calculated highest figure-of-merit corresponds to a filling factor and a grid spacing-to-linewidth ratio of 0.025 and 39, respectively. To demonstrate the capability of the proposed method the sheet resistance of a continuous 2 nm Ni film (>950 OMEGA/square) is reduced to approx6.5 OMEGA/square when a 100 nm thick Cu grid is deposited on it. The transparency is instead maintained at values exceeding 75%. These results, which can be further improved by making thicker grids, already demonstrate the potential in applications, such as photovoltaic cells, optical detectors and displays.

  17. "Bottom-up" transparent electrodes.

    PubMed

    Morag, Ahiud; Jelinek, Raz

    2016-11-15

    Transparent electrodes (TEs) have attracted significant scientific, technological, and commercial interest in recent years due to the broad and growing use of such devices in electro-optics, consumer products (touch-screens for example), solar cells, and others. Currently, almost all commercial TEs are fabricated through "top-down" approaches (primarily lithography-based techniques), with indium tin oxide (ITO) as the most common material employed. Several problems are encountered, however, in this field, including the cost and complexity of TE production using top-down technologies, the limited structural flexibility, high-cost of indium, and brittle nature and low transparency in the far-IR spectral region of ITO. Alternative routes based upon bottom-up processes, have recently emerged as viable alternatives for production of TEs. Bottom up technologies are based upon self-assembly of building blocks - atoms, molecules, or nanoparticles - generating thin patterned films that exhibit both electrical conductivity and optical transparency. In this Feature Article we discuss the recent progress in this active and exciting field, including bottom-up TE systems produced from carbon materials (carbon nanotubes, graphene, graphene-oxide), silver, gold, and other metals. The current hurdles encountered for broader use of bottom-up strategies along with their significant potential are analyzed. PMID:27545510

  18. MMS Spacecraft Observation of Near Tail Thin Current Sheets: Their Locations, Conditions for Formation and Relation to Geomagnetic Activity

    NASA Astrophysics Data System (ADS)

    Zhao, C.; Russell, C. T.; Strangeway, R. J.; Anderson, B. J.; Baumjohann, W.; Bromund, K. R.; Chutter, M.; Fischer, D.; Kepko, L.; Le Contel, O.; Leinweber, H. K.; Magnes, W.; Nakamura, R.; Plaschke, F.; Slavin, J. A.; Torbert, R. B.

    2015-12-01

    During the commissioning phase of the MMS mission, when the apogee (~12Re) of MMS orbit swept from the pre-midnight to the dusk section of the magnetosphere, the four spacecraft probed the dynamic region of the near-Earth magnetotail. The MMS fleet encountered many structures with unambiguously small-scale spatial gradient in magnetic field (comparable to the separation of the fleet), indicating the existence of very thin current sheets in this near-tail region. During this commissioning phase, the MMS spacecraft were in a string of pearls configuration, not ideally suitable for "curlometer" determination of the current density. Thus the current density and thickness of the sheets are only roughly determined using reasonable assumptions. In this study we correlate the current sheet's location and thickness with solar wind conditions and the ground magnetic field records.

  19. Graphite nanoplatelet assemblies for transparent and catalytic electrodes in dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Aderhold, Patrick

    Dye sensitized solar cells (DSSCs) are a class of photovoltaic devices that have the potential to provide high conversion efficiency at low production cost. Research to improve performance in the individual components is active, but attention must be paid to methods that improve scalability and production cost as well. Graphite nanoplatelets (GNP), thin stacks of graphene sheets with nanometer-scale thickness and micron-scale lateral dimensions, provide a unique opportunity for creating DSSC electrodes with simple manufacturing techniques and low-energy processing. For the counterelectrode, a composite paper, made by cofiltration and pressing of GNP and polypropylene (PP), yields a highly electrical conductive surface that is mechanically robust and chemically stable in electrolyte. Decoration of this surface with platinum nanoparticles (PtNPs) by a rapid microwave heating process produces a catalytic surface that rivals the current "thermalized" platinum standard counterelectrode. The GNP/PP/PtNP system, however, requires lower processing temperature and requires a fraction of the Pt loading. For the transparent electrode, thin sheets of GNP can be deposited on glass surfaces to create highly transparent coatings for use in photoanode construction. Substrate interactions and post treatments are examined and techniques for optimization are outlined. Overall GNP is shown to be a versatile and effective starting material for DSSC electrode construction and demonstrates its potential as a building-block in next-generation photovoltaic devices.

  20. Zinc oxyfluoride transparent conductor

    DOEpatents

    Gordon, Roy G.

    1991-02-05

    Transparent, electrically conductive and infrared-reflective films of zinc oxyfluoride are produced by chemical vapor deposition from vapor mixtures of zinc, oxygen and fluorine-containing compounds. The substitution of fluorine for some of the oxygen in zinc oxide results in dramatic increases in the electrical conductivity. For example, diethyl zinc, ethyl alcohol and hexafluoropropene vapors are reacted over a glass surface at 400.degree. C. to form a visibly transparent, electrically conductive, infrared reflective and ultraviolet absorptive film of zinc oxyfluoride. Such films are useful in liquid crystal display devices, solar cells, electrochromic absorbers and reflectors, energy-conserving heat mirrors, and antistatic coatings.

  1. Simultaneous observation of the poleward expansion of substorm electrojet activity and the tailward expansion of current sheet disruption in the near-earth magnetotail

    SciTech Connect

    Lopez, R.E. ); Koskinen, H.E.J.; Pulkkinen, T.I. ); Boesinger, T. ); McEntire, R.W.; Potemra, T.A. )

    1993-06-01

    This paper reports on observations of a magnetospheric substorm on June 7, 1985. This event was observed simultaneously by a number of different systems. Particle and magnetic field data were collected by AMPTE/CCE, located near the neutral sheet; magnetic field data was monitored by the EISCAT magnetometer cross; STARE radar data was also collected; and Pi 1 data from Sodankyla. The ground based systems observed the poleward and westward expansion of electrojet activity at the start of the storm. The satellite was able to see the storms onset, and record perturbations in the current sheet at the onset of the substorm, in addition to later perturbations, which the authors argue originates tailward of the satellite. Satellite measurements are shown to occur in conjunction with ground events.

  2. Lutetium oxide-based transparent ceramic scintillators

    DOEpatents

    Seeley, Zachary; Cherepy, Nerine; Kuntz, Joshua; Payne, Stephen A.

    2016-01-19

    In one embodiment, a transparent ceramic of sintered nanoparticles includes gadolinium lutetium oxide doped with europium having a chemical composition (Lu.sub.1-xGd.sub.x).sub.2-YEu.sub.YO.sub.3, where X is any value within a range from about 0.05 to about 0.45 and Y is any value within a range from about 0.01 to about 0.2, and where the transparent ceramic exhibits a transparency characterized by a scatter coefficient of less than about 10%/cm. In another embodiment, a transparent ceramic scintillator of sintered nanoparticles, includes a body of sintered nanoparticles including gadolinium lutetium oxide doped with a rare earth activator (RE) having a chemical composition (Lu.sub.1-xGd.sub.x).sub.2-YRE.sub.YO.sub.3, where RE is selected from the group consisting of: Sm, Eu, Tb, and Dy, where the transparent ceramic exhibits a transparency characterized by a scatter coefficient of less than about 10%/cm.

  3. Transparent antennas for solar cell integration

    NASA Astrophysics Data System (ADS)

    Yasin, Tursunjan

    Transparent patch antennas are microstrip patch antennas that have a certain level of optical transparency. Highly transparent patch antennas are potentially suitable for integration with solar panels of small satellites, which are becoming increasingly important in space exploration. Traditional patch antennas employed on small satellites compete with solar cells for surface area. However, a transparent patch antenna can be placed directly on top of solar cells and resolve the issue of competing for limited surface real estate. For such an integration, a high optical transparency of the patch antenna is required from the solar cells' point of view. On the other hand, the antenna should possess at least acceptable radiation properties at the same time. This dissertation focuses on some of the most important concerns from the perspective of small satellite applications. For example, an optimization method to simultaneously improve both optical transparency and radiation efficiency of the antenna is studied. Active integrated antenna design method is extended to meshed patch applications in an attempt to improve the overall power efficiency of the front end communication subsystem. As is well known, circular polarization is immune from Faraday rotation effect in the ionosphere and thus can avoid a 3-dB loss in geo-satellite communication. Therefore, this research also aims to present design methods for circularly polarized meshed patch antennas. Moreover, a meshed patch antenna capable of supporting a high communication data rate is investigated. Lastly, other types of transparent patch antennas are also analyzed and compared to meshed patches. In summary, many properties of transparent patch antennas are examined in order to meet different design requirements.

  4. A transparent electrode based on a metal nanotrough network

    NASA Astrophysics Data System (ADS)

    Wu, Hui; Kong, Desheng; Ruan, Zhichao; Hsu, Po-Chun; Wang, Shuang; Yu, Zongfu; Carney, Thomas J.; Hu, Liangbing; Fan, Shanhui; Cui, Yi

    2013-06-01

    Transparent conducting electrodes are essential components for numerous flexible optoelectronic devices, including touch screens and interactive electronics. Thin films of indium tin oxide--the prototypical transparent electrode material--demonstrate excellent electronic performances, but film brittleness, low infrared transmittance and low abundance limit suitability for certain industrial applications. Alternatives to indium tin oxide have recently been reported and include conducting polymers, carbon nanotubes and graphene. However, although flexibility is greatly improved, the optoelectronic performance of these carbon-based materials is limited by low conductivity. Other examples include metal nanowire-based electrodes, which can achieve sheet resistances of less than 10Ω □-1 at 90% transmission because of the high conductivity of the metals. To achieve these performances, however, metal nanowires must be defect-free, have conductivities close to their values in bulk, be as long as possible to minimize the number of wire-to-wire junctions, and exhibit small junction resistance. Here, we present a facile fabrication process that allows us to satisfy all these requirements and fabricate a new kind of transparent conducting electrode that exhibits both superior optoelectronic performances (sheet resistance of ~2Ω □-1 at 90% transmission) and remarkable mechanical flexibility under both stretching and bending stresses. The electrode is composed of a free-standing metallic nanotrough network and is produced with a process involving electrospinning and metal deposition. We demonstrate the practical suitability of our transparent conducting electrode by fabricating a flexible touch-screen device and a transparent conducting tape.

  5. Transparent, Weakly Conductive Films for Space Applications

    NASA Technical Reports Server (NTRS)

    Griffin, John; Morgan, Ashraf; Hambourger, Paul D.

    2004-01-01

    Electrically insulating spacecraft surfaces are vulnerable to nonuniform charge buildup due to particles emitted by the sun. On Mars, insulating surfaces of exploration vehicles and structures will be affected by dust coatings possibly held in place by triboelectric surface charge. Application of a conductive film may be a solution to the charging problem, but the coating must be highly transparent if used on solar panels, lenses, etc. Sheet resistivity requirements depend on the application and are in the range 10(exp 2) - 10(exp 8) ohms/square. Co-deposited indium tin oxide (ITO) and MgF2 is promising, with high transparency, tailorable electrical properties, and durability to atomic oxygen. Due to ITO's relatively narrow bandgap (approximately 3.5 eV), the film might absorb enough ultraviolet to protect polymeric substrates. Recent work on dual-magnetron-sputtered ITO-MgF2 showed that a variety of polymeric substrates can be coated at room temperature. However, the sheet resistivity is very sensitive to composition, suggestive of a percolation transition. This could be a serious problem for large-scale coating production. We will report on attempts to control film composition by plasma emission monitoring of the ITO and MgF2 guns.

  6. Transparent, Weakly Conductive Films for Space Applications

    NASA Astrophysics Data System (ADS)

    Griffin, John; Morgan, Ashraf; Hambourger, Paul

    2004-10-01

    Electrically insulating spacecraft surfaces are vulnerable to nonuniform charge buildup due to particles emitted by the sun. On Mars, insulating surfaces of exploration vehicles and structures will be affected by dust coatings possibly held in place by triboelectric surface charge. Application of a conductive film may be a solution to the charging problem, but the coating must be highly transparent if used on solar panels, lenses, etc. Sheet resistivity requirements depend on the application and are in the range 10^2-10^8 ohms/square. Co-deposited indium tin oxide (ITO) and MgF2 is promising, with high transparency, tailorable electrical properties, and durability to atomic oxygen.(Joyce A. Dever et al., NASA TM 1998-208499 (August 1998).) Due to ITO's relatively narrow bandgap ( ˜3.5 eV), the film might absorb enough ultraviolet to protect polymeric substrates. Recent work on dual-magnetron-sputtered ITO-MgF2 showed that a variety of polymeric substrates can be coated at room temperature.(Thomas Cashman et al., Vacuum Technology & Coating, September 2003, p. 38.) However, the sheet resistivity is very sensitive to composition, suggestive of a percolation transition. This could be a serious problem for large-scale coating production. We will report on attempts to control film composition by plasma emission monitoring of the ITO and MgF2 guns. Supported by NASA Glenn Research Center, Cooperative Agreements NCC3-1033 and NCC3-1065.

  7. Complicating Methodological Transparency

    ERIC Educational Resources Information Center

    Bridges-Rhoads, Sarah; Van Cleave, Jessica; Hughes, Hilary E.

    2016-01-01

    A historical indicator of the quality, validity, and rigor of qualitative research has been the documentation and disclosure of the behind-the-scenes work of the researcher. In this paper, we use what we call "methodological data" as a tool to complicate the possibility and desirability of such transparency. Specifically, we draw on our…

  8. Transparent conductive coatings

    NASA Technical Reports Server (NTRS)

    Ashok, S.

    1983-01-01

    Thin film transparent conductors are discussed. Materials with electrical conductivity and optical transparency are highly desirable in many optoelectronic applications including photovoltaics. Certain binary oxide semiconductors such as tin oxide (SnO2) and indium oxide (In2O3) offer much better performance tradeoff in optoelectronics as well as better mechanical and chemical stability than thin semitransparent films. These thin-film transparent conductors (TC) are essentially wide-bandgap degenerate semiconductors - invariably n-type - and hence are transparent to sub-bandgap (visible) radiation while affording high electrical conductivity due to the large free electron concentration. The principal performance characteristics of TC's are, of course, electrical conductivity and optical transmission. The TC's have a refractive index of around 2.0 and hence act as very efficient antireflection coatings. For using TC's in surface barrier solar cells, the photovoltaic barrier is of utmost importance and so the work function or electron affinity of the TC is also a very important material parameter. Fabrication processes are discussed.

  9. Remote Monitoring Transparency Program

    SciTech Connect

    Sukhoruchkin, V.K.; Shmelev, V.M.; Roumiantsev, A.N.

    1996-08-01

    The objective of the Remote Monitoring Transparency Program is to evaluate and demonstrate the use of remote monitoring technologies to advance nonproliferation and transparency efforts that are currently being developed by Russia and the United States without compromising the national security to the participating parties. Under a lab-to-lab transparency contract between Sandia National Laboratories (SNL) and the Kurchatov Institute (KI RRC), the Kurchatov Institute will analyze technical and procedural aspects of the application of remote monitoring as a transparency measure to monitor inventories of direct- use HEU and plutonium (e.g., material recovered from dismantled nuclear weapons). A goal of this program is to assist a broad range of political and technical experts in learning more about remote monitoring technologies that could be used to implement nonproliferation, arms control, and other security and confidence building measures. Specifically, this program will: (1) begin integrating Russian technologies into remote monitoring systems; (2) develop remote monitoring procedures that will assist in the application of remote monitoring techniques to monitor inventories of HEU and Pu from dismantled nuclear weapons; and (3) conduct a workshop to review remote monitoring fundamentals, demonstrate an integrated US/Russian remote monitoring system, and discuss the impacts that remote monitoring will have on the national security of participating countries.

  10. Raising and Transparency.

    ERIC Educational Resources Information Center

    Langacker, Ronald W.

    1995-01-01

    An account of the phenomena that transformational syntax handled by means of "raising" is formulated in the context of cognitive grammar. Raising is analyzed as a special case of the metonymy that relational expressions exhibit in regard to their choice of overtly coded arguments. The transparency of these constructions is explained. (83…

  11. Remote Monitoring Transparency Program

    SciTech Connect

    Sukhoruchkin, V.K.; Shmelev, V.M.; Roumiantsev, A.N.; Croessmann, C.D.; Horton, R.D.; Matter, J.C.; Czajkowski, A.F.; Sheely, K.B.; Bieniawski, A.J.

    1996-12-31

    The objective of the Remote Monitoring Transparency Program is to evaluate and demonstrate the use of remote monitoring technologies to advance nonproliferation and transparency efforts that are currently being developed by Russia and the US without compromising the national security of the participating parties. Under a lab-to-lab transparency contract between Sandia National Laboratories (SNL) and the Kurchatov Institute (KI RRC), the Kurchatov Institute will analyze technical and procedural aspects of the application of remote monitoring as a transparency measure to monitor inventories of direct-use HEU and plutonium (e.g., material recovered from dismantled nuclear weapons). A goal of this program is to assist a broad range of political and technical experts in learning more about remote monitoring technologies that could be used to implement nonproliferation, arms control, and other security and confidence building measures. Specifically, this program will: (1) begin integrating Russian technologies into remote monitoring systems; (2) develop remote monitoring procedures that will assist in the application of remote monitoring techniques to monitor inventories of HEU and Pu from dismantled nuclear weapons; and (3) conduct a workshop to review remote monitoring fundamentals, demonstrate an integrated US/Russian remote monitoring will have on the national security of participating countries.

  12. Flexible, transparent and high-power triboelectric generator with asymmetric graphene/ITO electrodes

    NASA Astrophysics Data System (ADS)

    Song, Xinbo; Chen, Yuanfu; Li, Pingjian; Liu, Jingbo; Qi, Fei; Zheng, Binjie; Zhou, Jinhao; Hao, Xin; Zhang, Wanli

    2016-07-01

    The reported flexible and transparent triboelectric generator (FTTG) can only output ultralow power density (∼2 μW cm‑2), which has seriously hindered its further development and application. The low power density of FTTG is mainly limited by the transparent material and the electrode structure. Herein, for the first time, a FTTG with a superior power density of 60.7 μW cm‑2 has been fabricated by designing asymmetric electrodes where graphene and indium tin oxide (ITO) act as top and bottom electrodes respectively. Moreover, the performance of FTTG with graphene/ITO (G/I) asymmetric electrodes (GI-FTTG) almost remains unchanged even after 700 cycles, indicating excellent mechanical stability. The excellent performance of GI-FTTG can be attributed to the suitable materials and unique asymmetric electrode structure: the extraordinary flexibility of the graphene top electrode ensures the GI-FTTG excellent mechanical robustness and stability even after longer cycles, and the bottom electrode with very low sheet resistance guarantees lower internal resistance and higher production rate of induction charges to obtain higher output power density. It shows that light-emitting diodes (LED) can be easily powered by GI-FTTG, which demonstrates that the GI-FTTG is very promising for harvesting electrical energy from human activities by using flexible and transparent devices.

  13. Flexible, transparent and high-power triboelectric generator with asymmetric graphene/ITO electrodes.

    PubMed

    Song, Xinbo; Chen, Yuanfu; Li, Pingjian; Liu, Jingbo; Qi, Fei; Zheng, Binjie; Zhou, Jinhao; Hao, Xin; Zhang, Wanli

    2016-07-29

    The reported flexible and transparent triboelectric generator (FTTG) can only output ultralow power density (∼2 μW cm(-2)), which has seriously hindered its further development and application. The low power density of FTTG is mainly limited by the transparent material and the electrode structure. Herein, for the first time, a FTTG with a superior power density of 60.7 μW cm(-2) has been fabricated by designing asymmetric electrodes where graphene and indium tin oxide (ITO) act as top and bottom electrodes respectively. Moreover, the performance of FTTG with graphene/ITO (G/I) asymmetric electrodes (GI-FTTG) almost remains unchanged even after 700 cycles, indicating excellent mechanical stability. The excellent performance of GI-FTTG can be attributed to the suitable materials and unique asymmetric electrode structure: the extraordinary flexibility of the graphene top electrode ensures the GI-FTTG excellent mechanical robustness and stability even after longer cycles, and the bottom electrode with very low sheet resistance guarantees lower internal resistance and higher production rate of induction charges to obtain higher output power density. It shows that light-emitting diodes (LED) can be easily powered by GI-FTTG, which demonstrates that the GI-FTTG is very promising for harvesting electrical energy from human activities by using flexible and transparent devices. PMID:27320289

  14. Enhanced sheet conductivity of Langmuir-Blodgett assembled graphene thin films by chemical doping

    NASA Astrophysics Data System (ADS)

    Matković, Aleksandar; Milošević, Ivana; Milićević, Marijana; Tomašević-Ilić, Tijana; Pešić, Jelena; Musić, Milenko; Spasenović, Marko; Jovanović, Djordje; Vasić, Borislav; Deeks, Christopher; Panajotović, Radmila; Belić, Milivoj R.; Gajić, Radoš

    2016-03-01

    We demonstrate a facile fabrication technique for highly conductive and transparent thin graphene films. Sheet conductivity of Langmuir-Blodgett assembled multi-layer graphene films is enhanced through doping with nitric acid, leading to a fivefold improvement while retaining the same transparency as un-doped films. Sheet resistivity of such chemically improved films reaches 10 {{k}}{{Ω }}/\\square , with optical transmittance 78% in the visible. When the films are encapsulated, the enhanced sheet conductivity effect is stable in time. In addition, stacking of multiple layers, as well as the dependence of the sheet resistivity upon axial strain have been investigated.

  15. Large-scale thrusting along the northern margin of the Tibetan Plateau and the southwest Tarim basin: 230 km long active Hotian thrust sheet

    NASA Astrophysics Data System (ADS)

    Suppe, J.; Wang, X.; He, D.; Liang, H.

    2015-12-01

    We present the geometry, kinematics and mechanics of large-scale active thrusting in the western Kunlunshan and southwest Tarim basin, which accounts for ~130-165km total shortening of Tarim crust at the northern margin of Tibet. The great frontal structure is the ~230km long bedding-parallel Hotian thrust sheet, which is perhaps the longest active intact thrust sheet in the world, composed of flat-lying strata of the Tarim basin sliding northward on a regional gypsum detachment at the base of the Cenozoic sequence. The toe of the Hotian thrust ramps to the surface two thirds of the way across the Tarim basin, forming the Selibuya-Mazartag hills in the Taklamakan sand desert. At the southern edge of the Tarim basin in the Kunlunshan foothills, a set of high-amplitude anticlines are growing by complex break-forward ramping and wedging in the Hotian thrust sheet as it steps up to the Cenozoic gypsum detachment from a regional Cambrian evaporate detachment that extends under Tibet. More interior structures such as the Tiklik thrust bring older strata and Proterozoic basement to the surface, together with their Cenozoic Tarim cover in the Buya basin. The Cambrian detachment also extends northward under the Tarim basin with minor hanging-wall deformation that locally warps the overlying Hotian thrust sheet, producing a complete syntectonic record in seismically imaged growth strata of its northward motion over these warps. Seismic profiles in the southwest Tarim foothill belt also reveal widespread growth strata that record much of the structural history beginning in the early Pliocene Atushi Formation. Ages of seismic reflectors are calibrated to a surface magnetostratigraphic sequence (Zheng et al., 2000). The beginning of thrusting and folding in the southwest Tarim basin north of the Tiklik thrust is dated at 3.6Ma with shortening >25km and a progressive northward propagation toward the Selibuya-Mazartag hills. The overall shortening rate is ~10 mm/yr. The gypsum

  16. Multiple-satellite studies of magnetospheric substorms: Plasma sheet recovery and the poleward leap of auroral-zone activity

    NASA Technical Reports Server (NTRS)

    Pytte, T.; Mcpherron, R. L.; Kivelson, M. G.; West, H. I., Jr.; Hones, E. W., Jr.

    1977-01-01

    Particle observations from pairs of satellites (Ogo 5, Vela 4A and 5B, Imp 3) during the recovery of plasma sheet thickness late in substorms were examined. Six of the nine events occurred within about 5 min in locations near the estimated position of the neutral sheet, but over wide ranges of east-west and radial separations. The time of occurrence and spatial extent of the recovery were related to the onset (defined by ground Pi 2 pulsations) and approximate location (estimated from ground mid-latitude magnetic signatures) of substorm expansions. It was found that the plasma sheet recovery occurred 10 - 30 min after the last in a series of Pi bursts, which were interpreted to indicate that the recovery was not due directly to a late, high latitude substorm expansion. The recovery was also observed to occur after the substorm current wedge had moved into the evening sector and to extend far to the east of the center of the last preceding substorm expansion.

  17. Effect of geometric lattice design on optical/electrical properties of transparent silver grid for organic solar cells.

    PubMed

    Lim, Ju Won; Lee, Young Tack; Pandey, Rina; Yoo, Tae-Hee; Sang, Byoung-In; Ju, Byeong-Kwon; Hwang, Do Kyung; Choi, Won Kook

    2014-11-01

    Silver (Ag) grid transparent electrode is one of the most promising transparent conducting electrodes (TCEs) to replace conventional indium tin oxide (ITO). We systematically investigate an effect of geometric lattice modifications on optical and electrical properties of Ag grid electrode. The reference Ag grid with 5 μm width and 100 μm pitch (duty of 0.05) prepared by conventional photo-lithography and lift-off processes shows the sheet resistance of 13.27 Ω/sq, transmittance of 81.1%, and resultant figure of merit (FOM) of 129.05. Three different modified Ag grid electrodes with stripe added-mesh (SAM), triangle-added mesh (TAM), and diagonal-added mesh (DAM) are suggested to improve optical and electrical properties. Although all three of SAM, TAM, and DAM Ag grid electrodes exhibit the lower transmittance values of about 72 - 77%, they showed much decreased sheet resistance of 6 - 8 Ω/sq. As a result, all of the lattice-modified Ag grid electrodes display significant improvement of FOM and the highest value of 171.14 is obtained from DAM Ag grid, which is comparable to that of conventional ITO electrode (175.46). Also, the feasibility of DAM Ag gird electrode for use in organic solar cell is confirmed by finite difference time domain (FDTD) simulations. Unlike a conventional ITO electrode, DAM Ag grid electrode can induce light scattering and trapping due to the diffuse transmission that compensates for the loss in optical transparency, resulting in comparable light absorption in the photo active layer of poly(3-hexylthiophene) (P3HT): [6,6]-phenyl-C61-butyric acid methyl ester (PC₆₀BM). P3HT:PC₆₀BM based OSCs with the DAM Ag grid electrode were fabricated, which also showed the potential for ITO-free transparent electrode. PMID:25401837

  18. Transparent conducting oxide nanotubes

    NASA Astrophysics Data System (ADS)

    Alivov, Yahya; Singh, Vivek; Ding, Yuchen; Nagpal, Prashant

    2014-09-01

    Thin film or porous membranes made of hollow, transparent, conducting oxide (TCO) nanotubes, with high chemical stability, functionalized surfaces and large surface areas, can provide an excellent platform for a wide variety of nanostructured photovoltaic, photodetector, photoelectrochemical and photocatalytic devices. While large-bandgap oxide semiconductors offer transparency for incident light (below their nominal bandgap), their low carrier concentration and poor conductivity makes them unsuitable for charge conduction. Moreover, materials with high conductivity have nominally low bandgaps and hence poor light transmittance. Here, we demonstrate thin films and membranes made from TiO2 nanotubes heavily-doped with shallow Niobium (Nb) donors (up to 10%, without phase segregation), using a modified electrochemical anodization process, to fabricate transparent conducting hollow nanotubes. Temperature dependent current-voltage characteristics revealed that TiO2 TCO nanotubes, doped with 10% Nb, show metal-like behavior with resistivity decreasing from 6.5 × 10-4 Ωcm at T = 300 K (compared to 6.5 × 10-1 Ωcm for nominally undoped nanotubes) to 2.2 × 10-4 Ωcm at T = 20 K. Optical properties, studied by reflectance measurements, showed light transmittance up to 90%, within wavelength range 400 nm-1000 nm. Nb doping also improves the field emission properties of TCO nanotubes demonstrating an order of magnitude increase in field-emitter current, compared to undoped samples.

  19. Transparent conducting oxide nanotubes.

    PubMed

    Alivov, Yahya; Singh, Vivek; Ding, Yuchen; Nagpal, Prashant

    2014-09-26

    Thin film or porous membranes made of hollow, transparent, conducting oxide (TCO) nanotubes, with high chemical stability, functionalized surfaces and large surface areas, can provide an excellent platform for a wide variety of nanostructured photovoltaic, photodetector, photoelectrochemical and photocatalytic devices. While large-bandgap oxide semiconductors offer transparency for incident light (below their nominal bandgap), their low carrier concentration and poor conductivity makes them unsuitable for charge conduction. Moreover, materials with high conductivity have nominally low bandgaps and hence poor light transmittance. Here, we demonstrate thin films and membranes made from TiO2 nanotubes heavily-doped with shallow Niobium (Nb) donors (up to 10%, without phase segregation), using a modified electrochemical anodization process, to fabricate transparent conducting hollow nanotubes. Temperature dependent current-voltage characteristics revealed that TiO2 TCO nanotubes, doped with 10% Nb, show metal-like behavior with resistivity decreasing from 6.5 × 10(-4) Ωcm at T = 300 K (compared to 6.5 × 10(-1) Ωcm for nominally undoped nanotubes) to 2.2 × 10(-4) Ωcm at T = 20 K. Optical properties, studied by reflectance measurements, showed light transmittance up to 90%, within wavelength range 400 nm-1000 nm. Nb doping also improves the field emission properties of TCO nanotubes demonstrating an order of magnitude increase in field-emitter current, compared to undoped samples. PMID:25180635

  20. Dynamics of energetic plasma sheet electrons

    NASA Astrophysics Data System (ADS)

    Burin Des Roziers, Edward

    2009-06-01

    (rising and falling) variations in plasma sheet energetic electron fluxes during a single plasma sheet crossing. Case studies are presented for each type of event. The time it takes to fill/empty the plasma sheet of energetic electrons is quantified based on these events. Extreme events, most of which are associated with enhanced geomagnetic activity, showed that energetic electrons in the plasma sheet can vary up to several orders of magnitude. Interestingly, the energetic electron fluxes inside the plasma sheet can still undergo rapid variations when the solar wind is calm and geomagnetic activity is low.

  1. The most transparent research.

    PubMed

    Wenner, Melinda

    2009-10-01

    Biomedicine would be a breeze if organisms were transparent. With the ability to see through tissues, scientists could spot the development of tumors more easily in study animals. And biologists could study exactly how an animal's organs develop by observing them as they grow. In effect, the secrets of the body would be out there for everyone to see.The thought of peering into our tissues may sound like science fiction, but one day it could be science. Using ideas from genetics, electrical engineering, chemistry and solid-state physics, a handful of researchers are working on ways to render biological tissues transparent.Some have already succeeded: in 2007, Richard White, a biologist at the Dana Farber Cancer Institute in Boston, used careful breeding techniques to create a transparent adult zebrafish named casper, evoking a reference to the famous cartoon ghost by the same name. Now, more than 100 labs around the world are using these transparent fish to study cancer pathology and development in real time. "The field of in vivo imaging-looking at things that are happening inside an actual organism-is growing rapidly," White says.Researchers are even making strides toward turning human tissue transparent. The primary reason we can't see what's inside of us is that light scatters when it passes through tissue. The body is densely packed with many types of substances, such as bone and fat, and light travels through them at different speeds because they have what physicists refer to as different refractive indices. The result is that light can't pass through biological tissues in a straight line, much as car headlights don't pass through dense fog. To fix this problem, scientists are working on developing ways to stop tissues from scattering light. Indeed, "if you take away the scattering properties of human tissues, we would look more or less like jellyfish," explains Changhuei Yang, an electrical engineer and bioengineer at the California Institute of Technology

  2. Transparent superstrate terrestrial solar cell module

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The design, development, fabrication, and testing of the transparent solar cell module were examined. Cell performance and material process characteristics were determined by extensive tests and design modifications were made prior to preproduction fabrication. These tests included three cell submodules and two full size engineering modules. Along with hardware and test activity, engineering documentation was prepared and submitted.

  3. Efficient coating of transparent and conductive carbon nanotube thin films on plastic substrates.

    PubMed

    Andrew Ng, M H; Hartadi, Lysia T; Tan, Huiwen; Patrick Poa, C H

    2008-05-21

    Optically transparent and electrically conductive single-walled carbon nanotube (SWNT) thin films were fabricated at room temperature using a dip-coating technique. The film transparency and sheet resistance can be easily tailored by controlling the number of coatings. Aminopropyltriethoxysilane (APTS) was used as an adhesion promoter and, together with surfactant Triton X-100, greatly improved the SWNTs coating. Only five coats were required to obtain a sheet resistance of 2.05 [Formula: see text] and film transparency of 84 %T. The dip-coated film after post-deposition treatment with nitric acid has a sheet resistance as low as 130 [Formula: see text] at 69 %T. This technique is suitable for large-scale SWNT coating at room temperature and can be used on different types of substrates such as glass and plastics. This paper will discuss the role of the adhesion promoter and surfactant in the coating process. PMID:21825746

  4. Modeling Harris Current Sheets with Themis Observations

    NASA Technical Reports Server (NTRS)

    Kepko, L.; Angelopoulos, V.; McPherron, R. L.; Apatenkov, S.; Glassmeier, K.-H.

    2010-01-01

    Current sheets are ubiquitous in nature. occurring in such varied locations as the solar atmosphere. the heliosphere, and the Earth's magnetosphere. The simplest current sheet is the one-dimensional Harris neutral sheet, with the lobe field strength and scale-height the only free parameters. Despite its simplicity, confirmation of the Harris sheet as a reasonable description of the Earth's current sheet has remained elusive. In early 2009 the orbits of the 5 THEMIS probes fortuitously aligned such that profiles of the Earth's current sheet could be modeled in a time dependent manner. For the few hours of alignment we have calculated the time history of the current sheet parameters (scale height and current) in the near-Earth region. during both quiet and active times. For one particular substorm. we further demonstrate good quantitative agreement with the diversion of cross tail current inferred from the Harris modeling with the ionospheric current inferred from ground magnetometer data.

  5. Indium Tin Oxide-Free Transparent Conductive Electrode for GaN-Based Ultraviolet Light-Emitting Diodes.

    PubMed

    Kim, Ja-Yeon; Jeon, Jong-Hyun; Kwon, Min-Ki

    2015-04-22

    Transparent conducting electrodes are important components of highly efficient ultraviolet light-emitting diodes (UV LEDs). Indium tin oxide (ITO) is commonly used to form a current spreading layer, but its UV-range optical transparency is limited with a low sheet resistance. We demonstrate a simple solution-based coating technique to obtain large-area, highly uniform, and conductive silver-nanowire-based electrodes that exhibit UV-range optical transparency better than that of ITO for the same sheet resistance. The UV LEDs fabricated using this current spreading layer showed improved optical power emission as well as improvement in electrical properties. PMID:25830932

  6. Seismic activity triggered by the interaction of ice sheet flow with the Sør Rondane Mountains, East-Antarctica

    NASA Astrophysics Data System (ADS)

    Camelbeeck, Thierry; Lombardi, Denis; Martin, Henri; Rapagnani, Giovanni

    2015-04-01

    The interactions of the Antarctic ice sheet with the various marginal orogenic belts is poorly understood. To make up for this lack of knowledge we installed in early 2014 in the Sør Rondane Mountains of eastern Queen Maud Land, five new broadband seismic stations, in addition to an existing permanent station setting up a 90 x 30 km wide seismic network. All stations are set up to be year-round autonomously powered, all but one being on rock outcrops. Despite technical problems encountered during winter, several months of data were collected and so far about 1 month of this dataset has been processed. The background seismic noise is found to be low to extremely low with seasonal variations suggesting influence from meteorological conditions. In addition to teleseismic events, a lot of local seismicity is observed and so far 155 local quakes were detected and localized using manual picking and 2 localization methods (Hypo and NonLinLoc). The inferred locations indicate 2 major source regions for these quakes: at the border between the ice sheet and outcropping mountains and within the fastest moving ice flow suggesting that the detected seismicity is correlated with the ice flow dynamics. Further information regarding the quake focal depths and the inferred crustal model will be discussed.

  7. Perceptual transparency from image deformation.

    PubMed

    Kawabe, Takahiro; Maruya, Kazushi; Nishida, Shin'ya

    2015-08-18

    Human vision has a remarkable ability to perceive two layers at the same retinal locations, a transparent layer in front of a background surface. Critical image cues to perceptual transparency, studied extensively in the past, are changes in luminance or color that could be caused by light absorptions and reflections by the front layer, but such image changes may not be clearly visible when the front layer consists of a pure transparent material such as water. Our daily experiences with transparent materials of this kind suggest that an alternative potential cue of visual transparency is image deformations of a background pattern caused by light refraction. Although previous studies have indicated that these image deformations, at least static ones, play little role in perceptual transparency, here we show that dynamic image deformations of the background pattern, which could be produced by light refraction on a moving liquid's surface, can produce a vivid impression of a transparent liquid layer without the aid of any other visual cues as to the presence of a transparent layer. Furthermore, a transparent liquid layer perceptually emerges even from a randomly generated dynamic image deformation as long as it is similar to real liquid deformations in its spatiotemporal frequency profile. Our findings indicate that the brain can perceptually infer the presence of "invisible" transparent liquids by analyzing the spatiotemporal structure of dynamic image deformation, for which it uses a relatively simple computation that does not require high-level knowledge about the detailed physics of liquid deformation. PMID:26240313

  8. Perceptual transparency from image deformation

    PubMed Central

    Kawabe, Takahiro; Maruya, Kazushi; Nishida, Shin’ya

    2015-01-01

    Human vision has a remarkable ability to perceive two layers at the same retinal locations, a transparent layer in front of a background surface. Critical image cues to perceptual transparency, studied extensively in the past, are changes in luminance or color that could be caused by light absorptions and reflections by the front layer, but such image changes may not be clearly visible when the front layer consists of a pure transparent material such as water. Our daily experiences with transparent materials of this kind suggest that an alternative potential cue of visual transparency is image deformations of a background pattern caused by light refraction. Although previous studies have indicated that these image deformations, at least static ones, play little role in perceptual transparency, here we show that dynamic image deformations of the background pattern, which could be produced by light refraction on a moving liquid’s surface, can produce a vivid impression of a transparent liquid layer without the aid of any other visual cues as to the presence of a transparent layer. Furthermore, a transparent liquid layer perceptually emerges even from a randomly generated dynamic image deformation as long as it is similar to real liquid deformations in its spatiotemporal frequency profile. Our findings indicate that the brain can perceptually infer the presence of “invisible” transparent liquids by analyzing the spatiotemporal structure of dynamic image deformation, for which it uses a relatively simple computation that does not require high-level knowledge about the detailed physics of liquid deformation. PMID:26240313

  9. The transparency of aging.

    PubMed

    Sorrell, Jeanne M

    2007-03-01

    This article is not meant to provide answers but to provoke thinking related to the questions we should be asking about the ethical personhood of aging adults. Are we covering over the rich opportunities to learn from their stories with an invisible cloak of transparency? Health care professionals have a moral obligation to rethink the assumptions that underlie their definitions of quality of life in aging. We cannot know what should be done unless we learn to listen to the life stories of aging people. This may even help us to see what is most real. PMID:17396715

  10. Transparent ultraviolet photovoltaic cells.

    PubMed

    Yang, Xun; Shan, Chong-Xin; Lu, Ying-Jie; Xie, Xiu-Hua; Li, Bing-Hui; Wang, Shuang-Peng; Jiang, Ming-Ming; Shen, De-Zhen

    2016-02-15

    Photovoltaic cells have been fabricated from p-GaN/MgO/n-ZnO structures. The photovoltaic cells are transparent to visible light and can transform ultraviolet irradiation into electrical signals. The efficiency of the photovoltaic cells is 0.025% under simulated AM 1.5 illumination conditions, while it can reach 0.46% under UV illumination. By connecting several such photovoltaic cells in a series, light-emitting devices can be lighting. The photovoltaic cells reported in this Letter may promise the applications in glass of buildings to prevent UV irradiation and produce power for household appliances in the future. PMID:26872163

  11. EDITORIAL: On display with transparent conducting films On display with transparent conducting films

    NASA Astrophysics Data System (ADS)

    Demming, Anna

    2012-03-01

    by a researcher in the early 1930s, 'It is obvious that if the dyes used for selective staining in ordinary microscopical work are supplemented by substances which cause a particular detail of the structure to fluoresce with a specific colour in ultraviolet light, then many strings will be added to the bow of the practical microscopist' [3]. More recently, emphasis on the role of plasmons—collective oscillations of electrons in nanoscale metal structures—has received considerable research attention. Plasmons enhance the local electromagnetic field and can lead to increased fluorescence rates from nearby fluorophores depending on the efficiency of the counteracting process, non-radiative transfer [4]. Flat ITO films have been used extensively in photovoltaic studies as transparent electrodes [5]. Over the past few years, nanowire structures have recently been used to increase the surface area of the interface between dye and oxide in dye-sensitized solar cells [6]. A collaboration of researchers in China and Australia has recently extended the innovation of the nanowire structure to the ITO electrode [7]. Using cyclic voltammetry the researchers confirmed that using a 3D ITO-nanowire electrode significantly enhanced the reaction current. Despite its attractive properties, alternatives to ITO are now in high demand. The rise in devices requiring flat electronic displays has begun to overwhelm the legitimacy of using such a rare element as indium for transparent conducting films. ITO is also brittle, causing problems for flexible displays. Films of carbon nanotubes have been proposed for transparent conducting films but improvements to the sheet resistance are needed before they can compete with the performance of ITO. The effects of HNO3 treatment on the resistivity of carbon nanotube films has attracted some debate in the community, and stimulated the work of Ji-Beom Yoo and colleagues in Korea [8]. Their results suggest that p-type doping has a larger effect on

  12. Strong correlation in acene sheets from the active-space variational two-electron reduced density matrix method: effects of symmetry and size.

    PubMed

    Pelzer, Kenley; Greenman, Loren; Gidofalvi, Gergely; Mazziotti, David A

    2011-06-01

    Polyaromatic hydrocarbons (PAHs) are a class of organic molecules with importance in several branches of science, including medicine, combustion chemistry, and materials science. The delocalized π-orbital systems in PAHs require highly accurate electronic structure methods to capture strong electron correlation. Treating correlation in PAHs has been challenging because (i) traditional wave function methods for strong correlation have not been applicable since they scale exponentially in the number of strongly correlated orbitals, and (ii) alternative methods such as the density-matrix renormalization group and variational two-electron reduced density matrix (2-RDM) methods have not been applied beyond linear acene chains. In this paper we extend the earlier results from active-space variational 2-RDM theory [Gidofalvi, G.; Mazziotti, D. A. J. Chem. Phys. 2008, 129, 134108] to the more general two-dimensional arrangement of rings--acene sheets--to study the relationship between geometry and electron correlation in PAHs. The acene-sheet calculations, if performed with conventional wave function methods, would require wave function expansions with as many as 1.5 × 10(17) configuration state functions. To measure electron correlation, we employ several RDM-based metrics: (i) natural-orbital occupation numbers, (ii) the 1-RDM von Neumann entropy, (iii) the correlation energy per carbon atom, and (iv) the squared Frobenius norm of the cumulant 2-RDM. The results confirm a trend of increasing polyradical character with increasing molecular size previously observed in linear PAHs and reveal a corresponding trend in two-dimensional (arch-shaped) PAHs. Furthermore, in PAHs of similar size they show significant variations in correlation with geometry. PAHs with the strictly linear geometry (chains) exhibit more electron correlation than PAHs with nonlinear geometries (sheets). PMID:21563790

  13. Mapping whole-brain activity with cellular resolution by light-sheet microscopy and high-throughput image analysis (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Silvestri, Ludovico; Rudinskiy, Nikita; Paciscopi, Marco; Müllenbroich, Marie Caroline; Costantini, Irene; Sacconi, Leonardo; Frasconi, Paolo; Hyman, Bradley T.; Pavone, Francesco S.

    2016-03-01

    Mapping neuronal activity patterns across the whole brain with cellular resolution is a challenging task for state-of-the-art imaging methods. Indeed, despite a number of technological efforts, quantitative cellular-resolution activation maps of the whole brain have not yet been obtained. Many techniques are limited by coarse resolution or by a narrow field of view. High-throughput imaging methods, such as light sheet microscopy, can be used to image large specimens with high resolution and in reasonable times. However, the bottleneck is then moved from image acquisition to image analysis, since many TeraBytes of data have to be processed to extract meaningful information. Here, we present a full experimental pipeline to quantify neuronal activity in the entire mouse brain with cellular resolution, based on a combination of genetics, optics and computer science. We used a transgenic mouse strain (Arc-dVenus mouse) in which neurons which have been active in the last hours before brain fixation are fluorescently labelled. Samples were cleared with CLARITY and imaged with a custom-made confocal light sheet microscope. To perform an automatic localization of fluorescent cells on the large images produced, we used a novel computational approach called semantic deconvolution. The combined approach presented here allows quantifying the amount of Arc-expressing neurons throughout the whole mouse brain. When applied to cohorts of mice subject to different stimuli and/or environmental conditions, this method helps finding correlations in activity between different neuronal populations, opening the possibility to infer a sort of brain-wide 'functional connectivity' with cellular resolution.

  14. Silver Nanowire Transparent Conductive Films with High Uniformity Fabricated via a Dynamic Heating Method.

    PubMed

    Jia, Yonggao; Chen, Chao; Jia, Dan; Li, Shuxin; Ji, Shulin; Ye, Changhui

    2016-04-20

    The uniformity of the sheet resistance of transparent conductive films is one of the most important quality factors for touch panel applications. However, the uniformity of silver nanowire transparent conductive films is far inferior to that of indium-doped tin oxide (ITO). Herein, we report a dynamic heating method using infrared light to achieve silver nanowire transparent conductive films with high uniformity. This method can overcome the coffee ring effect during the drying process and suppress the aggregation of silver nanowires in the film. A nonuniformity factor of the sheet resistance of the as-prepared silver nanowire transparent conductive films could be as low as 6.7% at an average sheet resistance of 35 Ω/sq and a light transmittance of 95% (at 550 nm), comparable to that of high-quality ITO film in the market. In addition, a mechanical study shows that the sheet resistance of the films has little change after 5000 bending cycles, and the film could be used in touch panels for human-machine interactive input. The highly uniform and mechanically stable silver nanowire transparent conductive films meet the requirement for many significant applications and could play a key role in the display market in a near future. PMID:27054546

  15. Transparency of graphene for low-energy electrons measured in a vacuum-triode setup

    SciTech Connect

    Hassink, G.; Wanke, R.; Rastegar, I.; Braun, W.; Stephanos, C.; Herlinger, P.; Smet, J. H.; Mannhart, J.

    2015-07-01

    Graphene, being an atomically thin conducting sheet, is a candidate material for gate electrodes in vacuum electronic devices, as it may be traversed by low-energy electrons. The transparency of graphene to electrons with energies between 2 and 40 eV has been measured by using an optimized vacuum-triode setup. The measured graphene transparency equals ∼60% in most of this energy range. Based on these results, nano-patterned sheets of graphene or of related two-dimensional materials are proposed as gate electrodes for ambipolar vacuum devices.

  16. Transparent metal electrodes from ordered nanosphere arrays

    NASA Astrophysics Data System (ADS)

    Morfa, Anthony J.; Akinoglu, Eser M.; Subbiah, Jegadesan; Giersig, Michael; Mulvaney, Paul

    2013-08-01

    We show that perforated metal electrode arrays, fabricated using nanosphere lithography, provide a viable alternative to conductive metal oxides as transparent electrode materials. The inter-aperture spacing is tuned by varying etching times in an oxygen plasma, and the effect of inter-aperture "wire" thickness on the optical and electronic properties of perforated silver films is shown. Optical transmission is limited by reflection and surface plasmons, and for these results do not exceed 73%. Electrical sheet resistance is shown to be as low as 3 Ω ◻-1 for thermally evaporated silver films. The performance of organic photovoltaic devices comprised of a P3HT:PCBM bulk heterojunction deposited onto perforated metal arrays is shown to be limited by optical transmission, and a simple model is presented to overcome these limitations.

  17. Micromachined edge illuminated optically transparent automotive light guide panels

    NASA Astrophysics Data System (ADS)

    Ronny, Rahima Afrose; Knopf, George K.; Bordatchev, Evgueni; Tauhiduzzaman, Mohammed; Nikumb, Suwas

    2012-03-01

    Edge-lit backlighting has been used extensively for a variety of small and medium-sized liquid crystal displays (LCDs). The shape, density and spatial distribution pattern of the micro-optical elements imprinted on the surface of the flat light-guide panel (LGP) are often "optimized" to improve the overall brightness and luminance uniformity. A similar concept can be used to develop interior convenience lighting panels and exterior tail lamps for automotive applications. However, costly diffusive sheeting and brightness enhancement films are not be considered for these applications because absolute luminance uniformity and the minimization of Moiré fringe effects are not significant factors in assessing quality of automotive lighting. A new design concept that involves micromilling cylindrical micro-optical elements on optically transparent plastic substrates is described in this paper. The variable parameter that controls illumination over the active regions of the panel is the depth of the individual cylindrical micro-optical elements. LightTools™ is the optical simulation tool used to explore how changing the micro-optical element depth can alter the local and global luminance. Numerical simulation and microfabrication experiments are performed on several (100mmx100mmx6mm) polymethylmethacrylate (PMMA) test samples in order to verify the illumination behavior.

  18. Positron annihilation in transparent ceramics

    NASA Astrophysics Data System (ADS)

    Husband, P.; Bartošová, I.; Slugeň, V.; Selim, F. A.

    2016-01-01

    Transparent ceramics are emerging as excellent candidates for many photonic applications including laser, scintillation and illumination. However achieving perfect transparency is essential in these applications and requires high technology processing and complete understanding for the ceramic microstructure and its effect on the optical properties. Positron annihilation spectroscopy (PAS) is the perfect tool to study porosity and defects. It has been applied to investigate many ceramic structures; and transparent ceramics field may be greatly advanced by applying PAS. In this work positron lifetime (PLT) measurements were carried out in parallel with optical studies on yttrium aluminum garnet transparent ceramics in order to gain an understanding for their structure at the atomic level and its effect on the transparency and light scattering. The study confirmed that PAS can provide useful information on their microstructure and guide the technology of manufacturing and advancing transparent ceramics.

  19. The transparency trap.

    PubMed

    Bernstein, Ethan

    2014-10-01

    To promote accountability, productivity, and shared learning, many organizations create open work environments and gather reams of data on how individuals spend their time. A few years ago, HBS professor Ethan Bernstein set out to find empirical evidence that such approaches improve organizational performance. What he discovered is that this kind of transparency often has an unintended consequence: It can leave employees feeling vulnerable and exposed. When that happens, they conceal any conduct that deviates from the norm so that they won't have to explain it. Unrehearsed, experimental behaviors sometimes stop altogether. But Bernstein also discovered organizations that had established zones of privacy within open environments by setting four types of boundaries: around teams, between feedback and evaluation, between decision rights and improvement rights, and around periods of experimentation. Moreover, across several studies, the companies that had done all this were the ones that consistently got the most creative, efficient, and thoughtful work from their employees. Bernstein's conclusion? By balancing transparency and privacy, organizations can capture the benefits of both, and encourage just the right amount of "positive deviance" needed to increase innovation and productivity. PMID:25509576

  20. Flexible transparent electrode

    NASA Astrophysics Data System (ADS)

    Demiryont, Hulya; Shannon, Kenneth C., III; Moorehead, David; Bratcher, Matthew

    2011-06-01

    This paper presents the properties of the EclipseTECTM transparent conductor. EclipseTECTM is a room temperature deposited nanostructured thin film coating system comprised of metal-oxide semiconductor elements. The system possesses metal-like conductivity and glass-like transparency in the visible region. These highly conductive TEC films exhibit high shielding efficiency (35dB at 1 to 100GHz). EclipseTECTM can be deposited on rigid or flexible substrates. For example, EclipseTECTM deposited on polyethylene terephthalate (PET) is extremely flexible that can be rolled around a 9mm diameter cylinder with little or no reduction in electrical conductivity and that can assume pre-extension states after an applied stress is relieved. The TEC is colorless and has been tailored to have high visible transmittance which matches the eye sensitivity curve and allows the viewing of true background colors through the coating. EclipseTECTM is flexible, durable and can be tailored at the interface for applications such as electron- or hole-injecting OLED electrodes as well as electrodes in flexible displays. Tunable work function and optical design flexibility also make EclipseTECTM well-suited as a candidate for grid electrode replacement in next-generation photovoltaic cells.

  1. Corneal structure and transparency

    PubMed Central

    Meek, Keith M.; Knupp, Carlo

    2015-01-01

    The corneal stroma plays several pivotal roles within the eye. Optically, it is the main refracting lens and thus has to combine almost perfect transmission of visible light with precise shape, in order to focus incoming light. Furthermore, mechanically it has to be extremely tough to protect the inner contents of the eye. These functions are governed by its structure at all hierarchical levels. The basic principles of corneal structure and transparency have been known for some time, but in recent years X-ray scattering and other methods have revealed that the details of this structure are far more complex than previously thought and that the intricacy of the arrangement of the collagenous lamellae provides the shape and the mechanical properties of the tissue. At the molecular level, modern technologies and theoretical modelling have started to explain exactly how the collagen fibrils are arranged within the stromal lamellae and how proteoglycans maintain this ultrastructure. In this review we describe the current state of knowledge about the three-dimensional stromal architecture at the microscopic level, and about the control mechanisms at the nanoscopic level that lead to optical transparency. PMID:26145225

  2. Instructional Materials on the Educational Resources Information Center (ERIC). Part Two. Information Sheets on ERIC.

    ERIC Educational Resources Information Center

    ERIC Clearinghouse on Teacher Education, Washington, DC.

    This set of information sheets on the Educational Resources Information Center (ERIC) is designed for use by persons responsible for instructing potential ERIC users and contributors. Adaptable for reproduction as overhead projection transparencies, the sheets are classified in two dimensions to provide for greater flexibility. The set of 50…

  3. High Resistivity Transparent/Conductive Coatings for Space Applications: Problems and Possible Improvements

    NASA Technical Reports Server (NTRS)

    Cashman, Thomas; Demko, Rikako; Uppala, Nischala; Vemulapalli, Jyothi; Welch, Bryan; Hambourger, Paul D.

    2003-01-01

    We have prepared transparent films with a sheet relativity of 10(exp 1) to 10(exp 12) ohm/square by co-depositing a transparent conducting oxide (TCO) with magnesium fluoride, using two independently controlled RF magnetron sputter guns to facilitate adjustment of the film composition, Co-deposited indium tin oxide (ITO) and MgF2 on quartz and flexible polymeric substrate exhibited reasonably stable sheet resistivity over several months' time, with substantially lower optical reflectance than that of pure ITO. However, exposure to low-intensity blue light reduces sheet resistivity by as much as two orders of magnitude. Our results suggest this photoconductivity effect may be present in all InO(x)-based materials. We find that sheet resistivity can by "tuned" by admitting a small amount of high-purity air during deposition offering the possibility of closed loop process control.

  4. Lightning as a space-weather hazard: UK thunderstorm activity modulated by the passage of the heliospheric current sheet

    NASA Astrophysics Data System (ADS)

    Owens, M. J.; Scott, C. J.; Bennett, A. J.; Thomas, S. R.; Lockwood, M.; Harrison, R. G.; Lam, M. M.

    2015-11-01

    Lightning flash rates, RL, are modulated by corotating interaction regions (CIRs) and the polarity of the heliospheric magnetic field (HMF) in near-Earth space. As the HMF polarity reverses at the heliospheric current sheet (HCS), typically within a CIR, these phenomena are likely related. In this study, RL is found to be significantly enhanced at the HCS and at 27 days prior/after. The strength of the enhancement depends on the polarity of the HMF reversal at the HCS. Near-Earth solar and galactic energetic particle fluxes are also ordered by HMF polarity, though the variations qualitatively differ from RL, with the main increase occurring prior to the HCS crossing. Thus, the CIR effect on lightning is either the result of compression/amplification of the HMF (and its subsequent interaction with the terrestrial system) or that energetic particle preconditioning of the Earth system prior to the HMF polarity change is central to solar wind lightning coupling mechanism.

  5. How hospitals approach price transparency.

    PubMed

    Houk, Scott; Cleverley, James O

    2014-09-01

    A survey of finance leaders found that hospitals with lower charges were more likely than other hospitals to emphasize making prices defensible rather than simply transparent. Finance leaders of hospitals with higher charges were more likely to express concern that price transparency would cause a reduction in hospital revenue by forcing them to lower charges. Those respondents said commercial payers likely will have to agree to renegotiate contracts for price transparency to be a financially viable proposition. PMID:25647890

  6. Large-scale thrusting along the northern margin of the Tibetan Plateau and the southwest Tarim basin: 230 km long active Hotian thrust sheet

    NASA Astrophysics Data System (ADS)

    Wang, Xin; Suppe, John; Liang, Hang; He, Dengfa

    2014-05-01

    We present the geometry, kinematics and mechanics of large-scale thrusting in the West Kunlun Shan and the southwest Tarim Basin, which is associated with the northward motion of Tibet. The great frontal structure is the ~230km long intact bedding parallel Hotian thrust sheet composed of strata of the Tarim Basin lying above a regional gypsum horizon at the base of the Cenozoic sequence. The toe of the Hotian thrust sheet steps steeply to the surface two thirds of the way across the basin forming the Selibuya-Mazartag hills in the sand desert. The Hotan thrust constitutes one of the longest active intact thrust sheets in the world, showing little internal deformation, however at its back it steps down to a Cambrian detachment at the base of the Paleozoic below a belt of complex high-amplitude anticlines near the front of the West Kunlun Shan, which display break-forward imbricate and wedge structure. More interior, steep reverse faults such as the Tieklik thrust bring older strata to the surface, including Paleozoic basement. The Cambrian detachment also extends northward under the Tarim basin with minor hanging-wall deformation that warps the Hotian Thrust sheet locally, causing the development of growth strata in the Hotian thrust sheet that providesa quantitative record of its motion over these warps. Seismic profiles in the southwest Tarim basin reveal widespread growth strata that record much of the structural history beginning in the early Pliocene Atushi Formation. Ages of seismic reflectors are calibrated to a surface magnetostratigraphic sequence(from Zheng et al., 2000)and traced throughout the seismic grid. The bottom of the growth strata is dated at 3.6 Ma indicating a Pliocene and younger age of thrusting and folding in the southwest Tarim Basin. Structural restoration suggests minimum shortening greater than 35km. The Tieklik thrust consumed at least 10 km in early Pliocene. The fold-and-thrust belts of the southwest Tarim basin shortened >25km in

  7. Transparent lithium-ion batteries.

    PubMed

    Yang, Yuan; Jeong, Sangmoo; Hu, Liangbing; Wu, Hui; Lee, Seok Woo; Cui, Yi

    2011-08-01

    Transparent devices have recently attracted substantial attention. Various applications have been demonstrated, including displays, touch screens, and solar cells; however, transparent batteries, a key component in fully integrated transparent devices, have not yet been reported. As battery electrode materials are not transparent and have to be thick enough to store energy, the traditional approach of using thin films for transparent devices is not suitable. Here we demonstrate a grid-structured electrode to solve this dilemma, which is fabricated by a microfluidics-assisted method. The feature dimension in the electrode is below the resolution limit of human eyes, and, thus, the electrode appears transparent. Moreover, by aligning multiple electrodes together, the amount of energy stored increases readily without sacrificing the transparency. This results in a battery with energy density of 10 Wh/L at a transparency of 60%. The device is also flexible, further broadening their potential applications. The transparent device configuration also allows in situ Raman study of fundamental electrochemical reactions in batteries. PMID:21788483

  8. High Temperature Transparent Furnace Development

    NASA Technical Reports Server (NTRS)

    Bates, Stephen C.

    1997-01-01

    This report describes the use of novel techniques for heat containment that could be used to build a high temperature transparent furnace. The primary objective of the work was to experimentally demonstrate transparent furnace operation at 1200 C. Secondary objectives were to understand furnace operation and furnace component specification to enable the design and construction of a low power prototype furnace for delivery to NASA in a follow-up project. The basic approach of the research was to couple high temperature component design with simple concept demonstration experiments that modify a commercially available transparent furnace rated at lower temperature. A detailed energy balance of the operating transparent furnace was performed, calculating heat losses through the furnace components as a result of conduction, radiation, and convection. The transparent furnace shells and furnace components were redesigned to permit furnace operation at at least 1200 C. Techniques were developed that are expected to lead to significantly improved heat containment compared with current transparent furnaces. The design of a thermal profile in a multizone high temperature transparent furnace design was also addressed. Experiments were performed to verify the energy balance analysis, to demonstrate some of the major furnace improvement techniques developed, and to demonstrate the overall feasibility of a high temperature transparent furnace. The important objective of the research was achieved: to demonstrate the feasibility of operating a transparent furnace at 1200 C.

  9. Free-Standing and Transparent Graphene Membrane of Polyhedron Box-Shaped Basic Building Units Directly Grown Using a NaCl Template for Flexible Transparent and Stretchable Solid-State Supercapacitors.

    PubMed

    Li, Na; Yang, Gongzheng; Sun, Yong; Song, Huawei; Cui, Hao; Yang, Guowei; Wang, Chengxin

    2015-05-13

    Transparency has never been integrated into freestanding flexible graphene paper (FF-GP), although FF-GP has been discussed extensively, because a thin transparent graphene sheet will fracture easily when the template or substrate is removed using traditional methods. Here, transparent FF-GP (FFT-GP) was developed using NaCl as the template and was applied in transparent and stretchable supercapacitors. The capacitance was improved by nearly 1000-fold compared with that of the laminated or wrinkled chemical vapor deposition graphene-film-based supercapacitors. PMID:25830301

  10. Transparent Conductive Nanostructures

    SciTech Connect

    2008-06-22

    The objectives of this program between UT-Battelle, LLC (the ''Contractor'') and (Battelle Memorial Institute) (the "Participant") were directed towards achieving significant improvement: in the electrical conductivity and optical/infrared transmission of single-wall carbon nanotube (SWNT)-based composite materials. These materials will be used in coating applications that range from aircraft canopies to display applications. The goal of the project was to obtain supported mats of SWNTs with sheet conductivities approaching 10 ohms/square combined with high optical transmission (>85% transmission at 550 nm), thereby permitting their application as a replacement for indium tin oxide (ITO) in a variety of applications such as flexible displays.

  11. Fabrication of optically transparent chitin nanocomposites

    NASA Astrophysics Data System (ADS)

    Shams, M. Iftekhar; Ifuku, Shinsuke; Nogi, Masaya; Oku, Takeshi; Yano, Hiroyuki

    2011-02-01

    This paper demonstrates the preparation of chitin nanofibers from crab shells using a simple mechanical treatment. The nanofibers are small enough to retain the transparency of neat acrylic resin. Possessing hydroxyl and amine/ N-acetyl functionalities, water suspension of chitin nanofibers was vacuum-filtered 9 times faster than cellulose nanofibers to prepare a nanofiber sheet of 90 mm in diameter. This is a prominent advantage of chitin nanofibers over cellulose nanofibers in terms of commercial application. Interestingly, chitin acrylic resin films exhibited much higher transparency than cellulose acrylic resin films owing to the close affinity between less hydrophilic chitin and hydrophobic resin. Furthermore, the incorporation of chitin nanofibers contributes to the significant improvement of the thermal expansion and mechanical properties of the neat acrylic resin. The properties of high light transmittance and low thermal expansion make chitin nanocomposites promising candidates for the substrate in a continuous roll-to-roll process in the manufacturing of various optoelectronic devices such as flat panel displays, bendable displays, and solar cells.

  12. 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.

  13. 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

    2016-01-01

    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

  14. 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

  15. Fabrication of fully transparent nanowire transistors for transparent and flexible electronics.

    PubMed

    Ju, Sanghyun; Facchetti, Antonio; Xuan, Yi; Liu, Jun; Ishikawa, Fumiaki; Ye, Peide; Zhou, Chongwu; Marks, Tobin J; Janes, David B

    2007-06-01

    The development of optically transparent and mechanically flexible electronic circuitry is an essential step in the effort to develop next-generation display technologies, including 'see-through' and conformable products. Nanowire transistors (NWTs) are of particular interest for future display devices because of their high carrier mobilities compared with bulk or thin-film transistors made from the same materials, the prospect of processing at low temperatures compatible with plastic substrates, as well as their optical transparency and inherent mechanical flexibility. Here we report fully transparent In(2)O(3) and ZnO NWTs fabricated on both glass and flexible plastic substrates, exhibiting high-performance n-type transistor characteristics with approximately 82% optical transparency. These NWTs should be attractive as pixel-switching and driving transistors in active-matrix organic light-emitting diode (AMOLED) displays. The transparency of the entire pixel area should significantly enhance aperture ratio efficiency in active-matrix arrays and thus substantially decrease power consumption. PMID:18654311

  16. Fabrication of fully transparent nanowire transistors for transparent and flexible electronics

    NASA Astrophysics Data System (ADS)

    Ju, Sanghyun; Facchetti, Antonio; Xuan, Yi; Liu, Jun; Ishikawa, Fumiaki; Ye, Peide; Zhou, Chongwu; Marks, Tobin J.; Janes, David B.

    2007-06-01

    The development of optically transparent and mechanically flexible electronic circuitry is an essential step in the effort to develop next-generation display technologies, including `see-through' and conformable products. Nanowire transistors (NWTs) are of particular interest for future display devices because of their high carrier mobilities compared with bulk or thin-film transistors made from the same materials, the prospect of processing at low temperatures compatible with plastic substrates, as well as their optical transparency and inherent mechanical flexibility. Here we report fully transparent In2O3 and ZnO NWTs fabricated on both glass and flexible plastic substrates, exhibiting high-performance n-type transistor characteristics with ~82% optical transparency. These NWTs should be attractive as pixel-switching and driving transistors in active-matrix organic light-emitting diode (AMOLED) displays. The transparency of the entire pixel area should significantly enhance aperture ratio efficiency in active-matrix arrays and thus substantially decrease power consumption.

  17. 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.

  18. Thermally Diffused Al:ZnO Thin Films for Broadband Transparent Conductor.

    PubMed

    Tong, Chong; Yun, Juhyung; Chen, Yen-Jen; Ji, Dengxin; Gan, Qiaoqiang; Anderson, Wayne A

    2016-02-17

    Here, we report an approach to realize highly transparent low resistance Al-doped ZnO (AZO) films for broadband transparent conductors. Thin Al films are deposited on ZnO surfaces, followed by thermal diffusion processes, introducing the Al doping into ZnO thin films. By utilizing the interdiffusion of Al, Zn, and O, the chemical state of Al on the surfaces can be converted to a fully oxidized state, resulting in a low sheet resistance of 6.2 Ω/sq and an excellent transparency (i.e., 96.5% at 550 nm and higher than 85% up to 2500 nm), which is superior compared with some previously reported values for indium tin oxide, solution processed AZO, and many transparent conducting materials using novel nanostructures. Such AZO films are also applied as transparent conducting layers for AZO/Si heterojunction solar cells, demonstrating their applications in optoelectronic devices. PMID:26807664

  19. Highly conducting graphene sheets and Langmuir-Blodgett films

    NASA Astrophysics Data System (ADS)

    Li, Xiaolin; Zhang, Guangyu; Bai, Xuedong; Sun, Xiaoming; Wang, Xinran; Wang, Enge; Dai, Hongjie

    2008-09-01

    Graphene is an intriguing material with properties that are distinct from those of other graphitic systems. The first samples of pristine graphene were obtained by `peeling off' and epitaxial growth. Recently, the chemical reduction of graphite oxide was used to produce covalently functionalized single-layer graphene oxide. However, chemical approaches for the large-scale production of highly conducting graphene sheets remain elusive. Here, we report that the exfoliation-reintercalation-expansion of graphite can produce high-quality single-layer graphene sheets stably suspended in organic solvents. The graphene sheets exhibit high electrical conductance at room and cryogenic temperatures. Large amounts of graphene sheets in organic solvents are made into large transparent conducting films by Langmuir-Blodgett assembly in a layer-by-layer manner. The chemically derived, high-quality graphene sheets could lead to future scalable graphene devices.

  20. Zika Virus Fact Sheet

    MedlinePlus

    ... 2014 Fact sheets Features Commentaries 2014 Multimedia Contacts Zika virus Fact sheet Updated 6 September 2016 Key facts ... and last for 2-7 days. Complications of Zika virus disease After a comprehensive review of evidence, there ...

  1. Structural Biology Fact Sheet

    MedlinePlus

    ... Home > Science Education > Structural Biology Fact Sheet Structural Biology Fact Sheet Tagline (Optional) Middle/Main Content Area What is structural biology? Structural biology is a field of science focused ...

  2. Air transparent soundproof window

    SciTech Connect

    Kim, Sang-Hoon; Lee, Seong-Hyun

    2014-11-15

    A soundproof window or wall which is transparent to airflow is presented. The design is based on two wave theories: the theory of diffraction and the theory of acoustic metamaterials. It consists of a three-dimensional array of strong diffraction-type resonators with many holes centered on each individual resonator. The negative effective bulk modulus of the resonators produces evanescent wave, and at the same time the air holes with subwavelength diameter existed on the surfaces of the window for macroscopic air ventilation. The acoustic performance levels of two soundproof windows with air holes of 20mm and 50mm diameters were measured. The sound level was reduced by about 30 - 35dB in the frequency range of 400 - 5,000Hz with the 20mm window, and by about 20 - 35dB in the frequency range of 700 - 2,200Hz with the 50mm window. Multi stop-band was created by the multi-layers of the window. The attenuation length or the thickness of the window was limited by background noise. The effectiveness of the soundproof window with airflow was demonstrated by a real installation.

  3. Transparent volume imaging

    NASA Astrophysics Data System (ADS)

    Wixson, Steve E.

    1990-07-01

    Transparent Volume Imaging began with the stereo xray in 1895 and ended for most investigators when radiation safety concerns eliminated the second view. Today, similiar images can be generated by the computer without safety hazards providing improved perception and new means of image quantification. A volumetric workstation is under development based on an operational prototype. The workstation consists of multiple symbolic and numeric processors, binocular stereo color display generator with large image memory and liquid crystal shutter, voice input and output, a 3D pointer that uses projection lenses so that structures in 3 space can be touched directly, 3D hard copy using vectograph and lenticular printing, and presentation facilities using stereo 35mm slide and stereo video tape projection. Volumetric software includes a volume window manager, Mayo Clinic's Analyze program and our Digital Stereo Microscope (DSM) algorithms. The DSM uses stereo xray-like projections, rapidly oscillating motion and focal depth cues such that detail can be studied in the spatial context of the entire set of data. Focal depth cues are generated with a lens and apeture algorithm that generates a plane of sharp focus, and multiple stereo pairs each with a different plane of sharp focus are generated and stored in the large memory for interactive selection using a physical or symbolic depth selector. More recent work is studying non-linear focussing. Psychophysical studies are underway to understand how people perce ive images on a volumetric display and how accurately 3 dimensional structures can be quantitated from these displays.

  4. Silver nanowire based flexible electrodes with improved properties: High conductivity, transparency, adhesion and low haze

    SciTech Connect

    Kiran Kumar, A.B.V.; Wan Bae, Chang; Piao, Longhai Kim, Sang-Ho

    2013-08-01

    Graphical abstract: This graphical abstract illustrates the schematic representation of the main drawbacks and rectifications for AgNWs based transparent electrodes. - Highlights: • Films exhibited low sheet resistance and optical properties with R{sub s} ≤ 30 Ω/□ and T ≥ 90%. • We decreased haze to 2% by controlling AgNWs length, diameter, and concentration. • We achieved good adhesion for AgNWs on PET film. • There is no significant change in resistance in the bending angle from 0° to 180°, and on twisting. - Abstract: Recent work has been focusing on solution processable transparent electrodes for various applications including solar cells and displays. As well as, the research aims majorly at silver nanowires (AgNWs) to replace ITO. We enhance the transparent electrode performance as a function of optical and mechanical properties with low sheet resistance, by controlling the AgNWs accept ratios, ink composition, and processing conditions. The nanowire network of transparent films agrees with the 2D percolation law. The film transmittance values at 550 nm are coping with a reference ITO film. Sheet resistance and haze values are suitable for flexible electronic applications. We fabricate transparent flexible film using a low-cost processing technique.

  5. Solution processed zinc oxide nanopyramid/silver nanowire transparent network films with highly tunable light scattering properties

    NASA Astrophysics Data System (ADS)

    Mehra, Saahil; Christoforo, Mark G.; Peumans, Peter; Salleo, Alberto

    2013-05-01

    Metal nanowire transparent networks are promising replacements to indium tin oxide (ITO) transparent electrodes for optoelectronic devices. While the transparency and sheet resistance are key metrics for transparent electrode performance, independent control of the film light scattering properties is important to developing multifunctional electrodes for improved photovoltaic absorption. Here we show that controlled incorporation of ZnO nanopyramids into a metal nanowire network film affords independent, highly tunable control of the scattering properties (haze) with minimal effects on the transparency and sheet resistance. Varying the zinc oxide/silver nanostructure ratios prior to spray deposition results in sheet resistances, transmission (600 nm), and haze (600 nm) of 6-30 Ω □-1, 68-86%, and 34-66%, respectively. Incorporation of zinc oxide nanopyramid scattering agents into the conducting nanowire mesh has a negligible effect on mesh connectivity, providing a straightforward method of controlling electrode scattering properties. The decoupling of the film scattering power and electrical characteristics makes these films promising candidates for highly scattering transparent electrodes in optoelectronic devices and can be generalized to other metal nanowire films as well as carbon nanotube transparent electrodes.

  6. Aging Aircraft Transparencies: AN Italian Air Force Fleet Case History

    NASA Astrophysics Data System (ADS)

    Caucci, D.; Aiello, L.; Bagnoli, F.; Bernabei, M.

    2008-08-01

    Aircraft acrylic transparencies are structural components that must withstand flight and ground loads. Crazing occurrence, known as Environmental Stress Cracking (ESC), causes their substitution during aircraft maintenance operations. This form of aging is mainly a physical phenomenon due to the interaction of transparencies base material with an active liquid and leads craze formation at lower stress that would be required in air. In this paper, an extensive phenomenon of network ESC occurred on transparencies of many aircrafts operating in the same fleet was investigated. Cover application while parking was found to be the critical aspect in crazing appearance, thus acting as physical shield for condensed water and heat transferring.

  7. Optimal swimming of a sheet

    NASA Astrophysics Data System (ADS)

    Montenegro-Johnson, Thomas D.; Lauga, Eric

    2014-06-01

    Propulsion at microscopic scales is often achieved through propagating traveling waves along hairlike organelles called flagella. Taylor's two-dimensional swimming sheet model is frequently used to provide insight into problems of flagellar propulsion. We derive numerically the large-amplitude wave form of the two-dimensional swimming sheet that yields optimum hydrodynamic efficiency: the ratio of the squared swimming speed to the rate-of-working of the sheet against the fluid. Using the boundary element method, we show that the optimal wave form is a front-back symmetric regularized cusp that is 25% more efficient than the optimal sine wave. This optimal two-dimensional shape is smooth, qualitatively different from the kinked form of Lighthill's optimal three-dimensional flagellum, not predicted by small-amplitude theory, and different from the smooth circular-arc-like shape of active elastic filaments.

  8. Hybrid Transparent Conductive Films of Multilayer Graphene and Metal Grid for Organic Photovoltaics

    NASA Astrophysics Data System (ADS)

    Kim, Sung Man; Walker, Bright; Seo, Jung Hwa; Kang, Seong Jun

    2013-12-01

    Organic solar cells (OSCs) were fabricated on hybrid transparent conductive films consisting of multilayer graphene (MLG) and metal grids. MLG was transferred onto Ag grids to form hybrid transparent conductive films. The optical transmittance was found to be 87% at a wavelength of 550 nm, while the sheet resistance was measured to be 28 +/-7.9 Ω/square. The device characteristics of OSCs prepared on the hybrid films include an open circuit voltage of 0.58 V, a short circuit current of 8.05 mA/cm2, a fill factor of 51%, and a power conversion efficiency (PCE) of 2.38%. The PCE shows 11% improvement compared with that of OSCs fabricated using MLG films without Ag grids. This improvement can be attributed to the reduced sheet resistance of the hybrid film. These results indicate that hybrid films comprising MLG deposited on Ag grids constitute a promising transparent electrode for improving performance in OSCs.

  9. Ultrasmooth, extremely deformable and shape recoverable Ag nanowire embedded transparent electrode

    PubMed Central

    Nam, Sanggil; Song, Myungkwan; Kim, Dong-Ho; Cho, Byungjin; Lee, Hye Moon; Kwon, Jung-Dae; Park, Sung-Gyu; Nam, Kee-Seok; Jeong, Yongsoo; Kwon, Se-Hun; Park, Yun Chang; Jin, Sung-Ho; Kang, Jae-Wook; Jo, Sungjin; Kim, Chang Su

    2014-01-01

    Transparent electrodes have been widely used in electronic devices such as solar cells, displays, and touch screens. Highly flexible transparent electrodes are especially desired for the development of next generation flexible electronic devices. Although indium tin oxide (ITO) is the most commonly used material for the fabrication of transparent electrodes, its brittleness and growing cost limit its utility for flexible electronic devices. Therefore, the need for new transparent conductive materials with superior mechanical properties is clear and urgent. Ag nanowire (AgNW) has been attracting increasing attention because of its effective combination of electrical and optical properties. However, it still suffers from several drawbacks, including large surface roughness, instability against oxidation and moisture, and poor adhesion to substrates. These issues need to be addressed before wide spread use of metallic NW as transparent electrodes can be realized. In this study, we demonstrated the fabrication of a flexible transparent electrode with superior mechanical, electrical and optical properties by embedding a AgNW film into a transparent polymer matrix. This technique can produce electrodes with an ultrasmooth and extremely deformable transparent electrode that have sheet resistance and transmittance comparable to those of an ITO electrode. PMID:24763248

  10. Ultrasmooth, extremely deformable and shape recoverable Ag nanowire embedded transparent electrode.

    PubMed

    Nam, Sanggil; Song, Myungkwan; Kim, Dong-Ho; Cho, Byungjin; Lee, Hye Moon; Kwon, Jung-Dae; Park, Sung-Gyu; Nam, Kee-Seok; Jeong, Yongsoo; Kwon, Se-Hun; Park, Yun Chang; Jin, Sung-Ho; Kang, Jae-Wook; Jo, Sungjin; Kim, Chang Su

    2014-01-01

    Transparent electrodes have been widely used in electronic devices such as solar cells, displays, and touch screens. Highly flexible transparent electrodes are especially desired for the development of next generation flexible electronic devices. Although indium tin oxide (ITO) is the most commonly used material for the fabrication of transparent electrodes, its brittleness and growing cost limit its utility for flexible electronic devices. Therefore, the need for new transparent conductive materials with superior mechanical properties is clear and urgent. Ag nanowire (AgNW) has been attracting increasing attention because of its effective combination of electrical and optical properties. However, it still suffers from several drawbacks, including large surface roughness, instability against oxidation and moisture, and poor adhesion to substrates. These issues need to be addressed before wide spread use of metallic NW as transparent electrodes can be realized. In this study, we demonstrated the fabrication of a flexible transparent electrode with superior mechanical, electrical and optical properties by embedding a AgNW film into a transparent polymer matrix. This technique can produce electrodes with an ultrasmooth and extremely deformable transparent electrode that have sheet resistance and transmittance comparable to those of an ITO electrode. PMID:24763248

  11. Transparent electrode for optical switch

    DOEpatents

    Goldhar, Julius; Henesian, Mark A.

    1986-01-01

    A low pressure gas electrode utilizing ionized gas in a glow discharge regime forms a transparent electrode for electro-optical switches. The transparent electrode comprises a low pressure gas region on both sides of the crystal. When the gas is ionized, e.g., by a glow discharge in the low pressure gas, the plasma formed is a good conductor. The gas electrode acts as a highly uniform conducting electrode. Since the plasma is transparent to a high energy laser beam passing through the crystal, the electrode is a transparent electrode. A crystal exposed from two sides to such a plasma can be charged up uniformly to any desired voltage. The plasma can be created either by the main high voltage pulser used to charge up the crystal or by auxiliary discharges or external sources of ionization. A typical configuration utilizes 10 torr argon in the discharge region adjacent to each crystal face.

  12. Flexible Transparent Electronic Gas Sensors.

    PubMed

    Wang, Ting; Guo, Yunlong; Wan, Pengbo; Zhang, Han; Chen, Xiaodong; Sun, Xiaoming

    2016-07-01

    Flexible and transparent electronic gas sensors capable of real-time, sensitive, and selective analysis at room-temperature, have gained immense popularity in recent years for their potential to be integrated into various smart wearable electronics and display devices. Here, recent advances in flexible transparent sensors constructed from semiconducting oxides, carbon materials, conducting polymers, and their nanocomposites are presented. The sensing material selection, sensor device construction, and sensing mechanism of flexible transparent sensors are discussed in detail. The critical challenges and future development associated with flexible and transparent electronic gas sensors are presented. Smart wearable gas sensors are believed to have great potential in environmental monitoring and noninvasive health monitoring based on disease biomarkers in exhaled gas. PMID:27276698

  13. Fatigue-free, superstretchable, transparent, and biocompatible metal electrodes

    PubMed Central

    Guo, Chuan Fei; Liu, Qihan; Wang, Guohui; Wang, Yecheng; Shi, Zhengzheng; Suo, Zhigang; Chu, Ching-Wu; Ren, Zhifeng

    2015-01-01

    Next-generation flexible electronics require highly stretchable and transparent electrodes. Few electronic conductors are both transparent and stretchable, and even fewer can be cyclically stretched to a large strain without causing fatigue. Fatigue, which is often an issue of strained materials causing failure at low strain levels of cyclic loading, is detrimental to materials under repeated loads in practical applications. Here we show that optimizing topology and/or tuning adhesion of metal nanomeshes can significantly improve stretchability and eliminate strain fatigue. The ligaments in an Au nanomesh on a slippery substrate can locally shift to relax stress upon stretching and return to the original configuration when stress is removed. The Au nanomesh keeps a low sheet resistance and high transparency, comparable to those of strain-free indium tin oxide films, when the nanomesh is stretched to a strain of 300%, or shows no fatigue after 50,000 stretches to a strain up to 150%. Moreover, the Au nanomesh is biocompatible and penetrable to biomacromolecules in fluid. The superstretchable transparent conductors are highly desirable for stretchable photoelectronics, electronic skins, and implantable electronics. PMID:26392537

  14. Nanostructured electrochromic films by inkjet printing on large area and flexible transparent silver electrodes

    NASA Astrophysics Data System (ADS)

    Layani, Michael; Darmawan, Peter; Foo, Wan Ling; Liu, Liang; Kamyshny, Alexander; Mandler, Daniel; Magdassi, Schlomo; Lee, Pooi See

    2014-04-01

    Printed electrochromic flexible films were obtained by combining transparent silver grid electrodes formed by self-assembly and inkjet printed WO3 nanoparticles. Concentrated dispersions of WO3 nanoparticles were inkjet printed on transparent plastic silver grid electrodes with a high transparency of 83% in the spectral range of 400-800 nm, and a low sheet resistance in the range of 1-5 Ω sq-1. These electrodes were used for electrochromic applications for the first time. The resultant patterned nanostructured electrochromic films maintained their coloring and bleaching performance after bending of the flexible films.Printed electrochromic flexible films were obtained by combining transparent silver grid electrodes formed by self-assembly and inkjet printed WO3 nanoparticles. Concentrated dispersions of WO3 nanoparticles were inkjet printed on transparent plastic silver grid electrodes with a high transparency of 83% in the spectral range of 400-800 nm, and a low sheet resistance in the range of 1-5 Ω sq-1. These electrodes were used for electrochromic applications for the first time. The resultant patterned nanostructured electrochromic films maintained their coloring and bleaching performance after bending of the flexible films. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr06890k

  15. Optically transparent frequency selective surfaces on flexible thin plastic substrates

    NASA Astrophysics Data System (ADS)

    Dewani, Aliya A.; O'Keefe, Steven G.; Thiel, David V.; Galehdar, Amir

    2015-02-01

    A novel 2D simple low cost frequency selective surface was screen printed on thin (0.21 mm), flexible transparent plastic substrate (relative permittivity 3.2). It was designed, fabricated and tested in the frequency range 10-20 GHz. The plane wave transmission and reflection coefficients agreed with numerical modelling. The effective permittivity and thickness of the backing sheet has a significant effect on the frequency characteristics. The stop band frequency reduced from 15GHz (no backing) to 12.5GHz with polycarbonate. The plastic substrate thickness beyond 1.8mm has minimal effect on the resonant frequency. While the inner element spacing controls the stop-band frequency, the substrate thickness controls the bandwidth. The screen printing technique provided a simple, low cost FSS fabrication method to produce flexible, conformal, optically transparent and bio-degradable FSS structures which can find their use in electromagnetic shielding and filtering applications in radomes, reflector antennas, beam splitters and polarizers.

  16. Optically transparent frequency selective surfaces on flexible thin plastic substrates

    SciTech Connect

    Dewani, Aliya A. O’Keefe, Steven G.; Thiel, David V.; Galehdar, Amir

    2015-02-15

    A novel 2D simple low cost frequency selective surface was screen printed on thin (0.21 mm), flexible transparent plastic substrate (relative permittivity 3.2). It was designed, fabricated and tested in the frequency range 10-20 GHz. The plane wave transmission and reflection coefficients agreed with numerical modelling. The effective permittivity and thickness of the backing sheet has a significant effect on the frequency characteristics. The stop band frequency reduced from 15GHz (no backing) to 12.5GHz with polycarbonate. The plastic substrate thickness beyond 1.8mm has minimal effect on the resonant frequency. While the inner element spacing controls the stop-band frequency, the substrate thickness controls the bandwidth. The screen printing technique provided a simple, low cost FSS fabrication method to produce flexible, conformal, optically transparent and bio-degradable FSS structures which can find their use in electromagnetic shielding and filtering applications in radomes, reflector antennas, beam splitters and polarizers.

  17. Ag Nanowire Based Transparent Conductor for CIGS PV

    SciTech Connect

    Woods, L. M.; Wolk, J.; Smith, M.; Davande, H.; Ribelin, R. M.; Perkins, C. L.

    2011-01-01

    Coated silver nanowires (AgNW) have been considered as a replacement for transparent conducting oxides (TCOs) in CIGS based photovoltaic devices. The advantages of AgNW over TCOs are discussed, and optical and electrical characteristics of AgNWs on glass are presented. Similarly fabricated AgNWs with varying sheet resistance on CIGS devices were tested against ITO transparent conductor controls. The CIGS was produced using a roll-to-roll technique on a flexible polymer substrate. Variations in the ZnO layer resistivity that are adjacent to the AgNW layer in the CIGS device were also tested. Device results indicate similar Jsc, but a reduced FF for cells made with the AgNWs, and Voc dependence on the resistivity of the coated AgNW and ZnO window layers. FF and Voc losses associated with the use of AgNWs are discussed.

  18. 2011 Annual Health Physics Report for the HEU transparency Program

    SciTech Connect

    Radev, R

    2012-04-30

    During the 2008 calendar year, Lawrence Livermore National Laboratory (LLNL) provided health physics support for the Highly Enriched Uranium (HEU) Transparency Program for external and internal radiation protection. They also provided technical expertise related to BDMS radioactive sources and Russian radiation safety regulatory compliance. For the calendar year 2008, there were 158 person-trips that required dose monitoring of the U.S. monitors. Of the 158 person-trips, 148 person-trips were SMVs and 10 person-trips were Transparency Monitoring Office (TMO) trips. There were 6 monitoring visits by TMO monitors to facilities other than UEIE and 8 to UEIE itself. There were three monitoring visits (source changes) that were back-to-back with a total of 24 monitors. LLNL's Hazard Control Department laboratories provided the dosimetry services for the HEU Transparency monitors. In 2008, the HEU Transparency activities in Russia were conducted in a radiologically safe manner for the HEU Transparency monitors in accordance with the expectations of the HEU Transparency staff, NNSA and DOE. The HEU Transparency now has thirteen years of successful experience in developing and providing health and safety support in meeting its technical objectives.

  19. 2009 Annual Health Physics Report for the HEU Transparency Program

    SciTech Connect

    Radev, R

    2010-04-14

    During the 2009 calendar year, Lawrence Livermore National Laboratory (LLNL) provided health physics support for the Highly Enriched Uranium (HEU) Transparency Program for external and internal radiation protection. LLNL also provided technical expertise related to BDMS radioactive sources and Russian radiation safety regulatory compliance. For the calendar year 2009, there were 159 person-trips that required dose monitoring of the U.S. monitors. Of the 159 person-trips, 149 person-trips were SMVs and 10 person-trips were Transparency Monitoring Office (TMO) trips. There were 4 monitoring visits by TMO monitors to facilities other than UEIE and 10 to UEIE itself. LLNL's Hazard Control Department laboratories provided the dosimetry services for the HEU Transparency monitors. In 2009, the HEU Transparency activities in Russia were conducted in a radiologically safe manner for the HEU Transparency monitors in accordance with the expectations of the HEU Transparency staff, NNSA and DOE. The HEU Transparency Program now has over fifteen years of successful experience in developing and providing health and safety support in meeting its technical objectives.

  20. 46 CFR 232.4 - Balance sheet accounts.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Administration's Dividend Policy for Operators Receiving ODS (46 CFR part 283), accounting information for... 46 Shipping 8 2014-10-01 2014-10-01 false Balance sheet accounts. 232.4 Section 232.4 Shipping... ACTIVITIES UNIFORM FINANCIAL REPORTING REQUIREMENTS Balance Sheet § 232.4 Balance sheet accounts....

  1. 46 CFR 232.4 - Balance sheet accounts.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Administration's Dividend Policy for Operators Receiving ODS (46 CFR part 283), accounting information for... 46 Shipping 8 2013-10-01 2013-10-01 false Balance sheet accounts. 232.4 Section 232.4 Shipping... ACTIVITIES UNIFORM FINANCIAL REPORTING REQUIREMENTS Balance Sheet § 232.4 Balance sheet accounts....

  2. 46 CFR 232.4 - Balance sheet accounts.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Administration's Dividend Policy for Operators Receiving ODS (46 CFR part 283), accounting information for... 46 Shipping 8 2010-10-01 2010-10-01 false Balance sheet accounts. 232.4 Section 232.4 Shipping... ACTIVITIES UNIFORM FINANCIAL REPORTING REQUIREMENTS Balance Sheet § 232.4 Balance sheet accounts....

  3. 46 CFR 232.4 - Balance sheet accounts.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Administration's Dividend Policy for Operators Receiving ODS (46 CFR part 283), accounting information for... 46 Shipping 8 2011-10-01 2011-10-01 false Balance sheet accounts. 232.4 Section 232.4 Shipping... ACTIVITIES UNIFORM FINANCIAL REPORTING REQUIREMENTS Balance Sheet § 232.4 Balance sheet accounts....

  4. 46 CFR 232.4 - Balance sheet accounts.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Administration's Dividend Policy for Operators Receiving ODS (46 CFR part 283), accounting information for... 46 Shipping 8 2012-10-01 2012-10-01 false Balance sheet accounts. 232.4 Section 232.4 Shipping... ACTIVITIES UNIFORM FINANCIAL REPORTING REQUIREMENTS Balance Sheet § 232.4 Balance sheet accounts....

  5. Price transparency: building community trust.

    PubMed

    Clarke, Richard L

    2007-01-01

    With the push from policymakers, payers, and consumers for hospitals to make their prices public, healthcare executives need to recognize two central issues related to price transparency: 1) meaningful price transparency involves helping patients and consumers understand their financial obligation for an episode of care, and 2) price transparency is key to the most critical success strategy for healthcare providers: building trust. This article reviews the history of pricing and billing practices and explores why price transparency is not easily achieved in today's environment. Pricing is a mystery even to those of us who work in the field, yet despite its complexity, the call for price transparency is not going to go away. For transparency, the goal should be to establish a rational pricing system that is easily explainable and justified to all stakeholders. Healthcare executives must make pricing a priority, understand cost, develop a pricing philosophy, understand the overall revenue requirements, examine market conditions and prices, and set up systems for review. A rational process of price setting should enhance community trust. In this matter there is nothing less at stake than the hearts of our community members. PMID:17405387

  6. Insertion Structures for Transparent Metal Electrodes Prepared by Nanoimprint Lithography

    NASA Astrophysics Data System (ADS)

    Chen, Chia-Meng; Hsieh, Chih-Wei; Ho, Cheng-Fang; Sung, Cheng-Kuo

    2012-04-01

    This paper proposed an efficient process for manufacturing stable insertion structures inside poly(methyl methacrylate) (PMMA) substrates through only three steps, i.e., nanoimprint, metal deposition, and burnishing. The insertion structures with potential applications in transparent metal electrodes possess the advantages of being able to avoid the embedded nanostructure from damage due to contamination or stresses during packaging or transportation. In this paper, the Cu mesh of the insertion structure was successfully replicated into the PMMA substrate. The inserted Cu mesh electrode acquires an average optical transmittance of 84.6% in the visible regime and sheet resistance of 26.78 Ω/square.

  7. Construction of self-supported three-dimensional TiO2 sheeted networks with enhanced photocatalytic activity.

    PubMed

    Zhang, Xuan; Hu, Chao; Bai, Hua; Yan, Yan; Li, Junfang; Yang, Haifeng; Lu, Xiaojing; Xi, Guangcheng

    2013-01-01

    The degradation of toxic gases and liquids using a catalyst and solar energy is an ideal method, compared with landfill and combustion methods. The search for active semiconductor photocatalysts that efficiently decompose contaminations under light irradiation remains one of the most challenging tasks for solar-energy utilization. In this work, free-supporting three-dimensional (3D) nanosheeted hierarchical porous tungsten, titanium, and tin oxide networks were obtained by a facile Lewis acid catalytic binary template route. These networks possess large macroscopic scale (millimeter-sized) and hierarchical macro/mesoporous nanostructure with high surface area and large pore volume. Photocatalytic degradation of Azo dyes demonstrated that the nanosheets-constructed hierarchical porous networks have high photocatalytic activity and stability. The present synthetic route can serve as the new design concept for functional 3D layered porous nanostructures. PMID:24356418

  8. Inkjet printing of flexible high-performance carbon nanotube transparent conductive films by ``coffee ring effect''

    NASA Astrophysics Data System (ADS)

    Shimoni, Allon; Azoubel, Suzanna; Magdassi, Shlomo

    2014-09-01

    Transparent and flexible conductors are a major component in many modern optoelectronic devices, such as touch screens for smart phones, displays, and solar cells. Carbon nanotubes (CNTs) offer a good alternative to commonly used conductive materials, such as metal oxides (e.g. ITO) for flexible electronics. The production of transparent conductive patterns, and arrays composed of connected CNT ``coffee rings'' on a flexible substrate poly(ethylene terephthalate), has been reported. Direct patterning is achieved by inkjet printing of an aqueous dispersion of CNTs, which self-assemble at the rim of evaporating droplets. After post-printing treatment with hot nitric acid, the obtained TCFs are characterized by a sheet resistance of 156 Ω sq-1 and transparency of 81% (at 600 nm), which are the best reported values obtained by inkjet printing of conductive CNTs. This makes such films very promising as transparent conductors for various electronic devices, as demonstrated by using an electroluminescent device.

  9. Reversibly stretchable transparent conductive coatings of spray-deposited silver nanowires.

    PubMed

    Akter, Tahmina; Kim, Woo Soo

    2012-04-01

    Here, we report the creation of highly adhesive transparent and stretchable coatings via spray-deposition of solution-based silver nanowires (AgNWs). The AgNW dispersion was spray-deposited on a polydopamine-modified stretchable elastomeric substrate to prepare thin, stretchable, transparent, highly conductive films. The polydopamine layer on the elastomeric substrate created a highly hydrophilic surface, which facilitated the subsequent spraying of the AgNW solution. Additionally, the spray-deposited AgNWs demonstrated excellent adhesion to the substrate, which allowed the fabrication of stretchable electrodes with high conductivity. The AgNW-coated elastomeric substrate exhibited ~80% transmittance with an average sheet resistance of ~35 Ω/□, making it suitable for transparent electrode applications. The conductivity of the transparent electrode was maintained up to ~20% mechanical elongation, which demonstrated the stretchable characteristics of the AgNW-coated elastomeric substrate. PMID:22471630

  10. Metal-mesh based transparent electrode on a 3-D curved surface by electrohydrodynamic jet printing

    NASA Astrophysics Data System (ADS)

    Seong, Baekhoon; Yoo, Hyunwoong; Dat Nguyen, Vu; Jang, Yonghee; Ryu, Changkook; Byun, Doyoung

    2014-09-01

    Invisible Ag mesh transparent electrodes (TEs), with a width of 7 μm, were prepared on a curved glass surface by electrohydrodynamic (EHD) jet printing. With a 100 μm pitch, the EHD jet printed the Ag mesh on the convex glass which had a sheet resistance of 1.49 Ω/□. The printing speed was 30 cm s-1 using Ag ink, which had a 10 000 cPs viscosity and a 70 wt% Ag nanoparticle concentration. We further showed the performance of a 3-D transparent heater using the Ag mesh transparent electrode. The EHD jet printed an invisible Ag grid transparent electrode with good electrical and optical properties with promising applications on printed optoelectronic devices.

  11. Low-Work-Function, ITO-Free Transparent Cathodes for Inverted Polymer Solar Cells.

    PubMed

    Xue, Zhichao; Liu, Xingyuan; Lv, Ying; Zhang, Nan; Guo, Xiaoyang

    2015-09-16

    A low-work-function, indium tin oxide (ITO)-free transparent cathode having a tin oxide (SnOX)/Ag/SnOX/bismuth oxide (Bi2O3) (SASB) structure is developed without using annealing treatment. This represents the first time that Bi2O3 has been introduced to lower the work function of transparent electrodes. The SASB transparent cathode exhibits excellent photoelectric properties with a maximum transmittance of ∼88%, a low sheet resistance of ∼9.0 Ω·sq(-1), and a suitable work function of 4.22 eV that matches the lowest unoccupied molecular orbital level of the acceptor for exacting electrons efficiently. The power conversion efficiency of the polymer solar cell with the SASB electrode is 6.21%, which is comparable to that of ITO-based devices. The results indicate that SASB is a good alternative to ITO as transparent cathodes in optoelectronic devices. PMID:26323711

  12. Inkjet printing of flexible high-performance carbon nanotube transparent conductive films by "coffee ring effect".

    PubMed

    Shimoni, Allon; Azoubel, Suzanna; Magdassi, Shlomo

    2014-10-01

    Transparent and flexible conductors are a major component in many modern optoelectronic devices, such as touch screens for smart phones, displays, and solar cells. Carbon nanotubes (CNTs) offer a good alternative to commonly used conductive materials, such as metal oxides (e.g. ITO) for flexible electronics. The production of transparent conductive patterns, and arrays composed of connected CNT "coffee rings" on a flexible substrate poly(ethylene terephthalate), has been reported. Direct patterning is achieved by inkjet printing of an aqueous dispersion of CNTs, which self-assemble at the rim of evaporating droplets. After post-printing treatment with hot nitric acid, the obtained TCFs are characterized by a sheet resistance of 156 Ω sq(-1) and transparency of 81% (at 600 nm), which are the best reported values obtained by inkjet printing of conductive CNTs. This makes such films very promising as transparent conductors for various electronic devices, as demonstrated by using an electroluminescent device. PMID:25014193

  13. Microwave assisted synthesis of sheet-like Cu/BiVO{sub 4} and its activities of various photocatalytic conditions

    SciTech Connect

    Chen, Xi; Li, Li; Yi, Tingting; Zhang, WenZhi; Zhang, Xiuli; Wang, Lili

    2015-09-15

    The Cu/BiVO{sub 4} photocatalyst with visible-light responsivity was prepared by the microwave-assisted hydrothermal method. The phase structures, chemical composition and surface physicochemical properties were well-characterized via X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV–vis diffuse reflectance absorption (UV–vis/DRS), scanning electron microscopy (SEM), and N{sub 2} adsorption–desorption tests. Results indicate that the crystal structure of synthetic composite materials is mainly monoclinic scheelite BiVO{sub 4}, which is not changed with the increasing doping amount of Cu. In addition, the presence of Cu not only enlarges the range of the composite materials under the visible-light response, but also increases the BET value significantly. Compared to pure BiVO{sub 4}, 1% Cu/BiVO{sub 4}-160 performs the highest photocatalytic activity to degrade methylene blue under the irradiation of ultraviolet, visible and simulated sunlight. In addition, the capture experiments prove that the main active species was superoxide radicals during photocatalytic reaction. Moreover, the 1% Cu/BiVO{sub 4}-160 composite shows good photocatalytic stability after three times of recycling. - Graphical abstract: A series of BiVO{sub 4} with different amounts of Cu doping were prepared by the microwave-assisted method, moreover, which performed the high photocatalytic activities to degrade methylene blue under multi-mode. - Highlights: • A series of Cu/BiVO{sub 4} with different amounts of Cu doping were prepared by microwave-assisted synthesis. • The morphologies of as-samples were different with the amount of Cu doping increased. • Compared with pure BiVO{sub 4}, as-Cu/BiVO{sub 4} showed stronger absorption in the visible light region obviously. • 1% Cu/BiVO{sub 4}-160 performed the high photocatalytic activities to degrade methylene blue under multi-mode. • OH{sup •} and h{sup +} both play important roles in the photocatalytic reaction.

  14. Novel nanostructured paper with ultrahigh transparency and ultrahigh haze for solar cells.

    PubMed

    Fang, Zhiqiang; Zhu, Hongli; Yuan, Yongbo; Ha, Dongheon; Zhu, Shuze; Preston, Colin; Chen, Qingxia; Li, Yuanyuan; Han, Xiaogang; Lee, Seongwoo; Chen, Gang; Li, Teng; Munday, Jeremy; Huang, Jinsong; Hu, Liangbing

    2014-02-12

    Solar cell substrates require high optical transparency but also prefer high optical haze to increase the light scattering and consequently the absorption in the active materials. Unfortunately, there is a trade-off between these optical properties, which is exemplified by common transparent paper substrates exhibiting a transparency of about 90% yet a low optical haze (<20%). In this work, we introduce a novel transparent paper made of wood fibers that displays both ultrahigh optical transparency (∼ 96%) and ultrahigh haze (∼ 60%), thus delivering an optimal substrate design for solar cell devices. Compared to previously demonstrated nanopaper composed of wood-based cellulose nanofibers, our novel transparent paper has better dual performance in transmittance and haze but also is fabricated at a much lower cost. This high-performance, low-cost transparent paper is a potentially revolutionary material that may influence a new generation of environmentally friendly printed electronics. PMID:24372201

  15. Microwave assisted synthesis of sheet-like Cu/BiVO4 and its activities of various photocatalytic conditions

    NASA Astrophysics Data System (ADS)

    Chen, Xi; Li, Li; Yi, Tingting; Zhang, WenZhi; Zhang, Xiuli; Wang, Lili

    2015-09-01

    The Cu/BiVO4 photocatalyst with visible-light responsivity was prepared by the microwave-assisted hydrothermal method. The phase structures, chemical composition and surface physicochemical properties were well-characterized via X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance absorption (UV-vis/DRS), scanning electron microscopy (SEM), and N2 adsorption-desorption tests. Results indicate that the crystal structure of synthetic composite materials is mainly monoclinic scheelite BiVO4, which is not changed with the increasing doping amount of Cu. In addition, the presence of Cu not only enlarges the range of the composite materials under the visible-light response, but also increases the BET value significantly. Compared to pure BiVO4, 1% Cu/BiVO4-160 performs the highest photocatalytic activity to degrade methylene blue under the irradiation of ultraviolet, visible and simulated sunlight. In addition, the capture experiments prove that the main active species was superoxide radicals during photocatalytic reaction. Moreover, the 1% Cu/BiVO4-160 composite shows good photocatalytic stability after three times of recycling.

  16. Highly efficient fully transparent inverted OLEDs

    NASA Astrophysics Data System (ADS)

    Meyer, J.; Winkler, T.; Hamwi, S.; Schmale, S.; Kröger, M.; Görrn, P.; Johannes, H.-H.; Riedl, T.; Lang, E.; Becker, D.; Dobbertin, T.; Kowalsky, W.

    2007-09-01

    One of the unique selling propositions of OLEDs is their potential to realize highly transparent devices over the visible spectrum. This is because organic semiconductors provide a large Stokes-Shift and low intrinsic absorption losses. Hence, new areas of applications for displays and ambient lighting become accessible, for instance, the integration of OLEDs into the windshield or the ceiling of automobiles. The main challenge in the realization of fully transparent devices is the deposition of the top electrode. ITO is commonly used as transparent bottom anode in a conventional OLED. To obtain uniform light emission over the entire viewing angle and a low series resistance, a TCO such as ITO is desirable as top contact as well. However, sputter deposition of ITO on top of organic layers causes damage induced by high energetic particles and UV radiation. We have found an efficient process to protect the organic layers against the ITO rf magnetron deposition process of ITO for an inverted OLED (IOLED). The inverted structure allows the integration of OLEDs in more powerful n-channel transistors used in active matrix backplanes. Employing the green electrophosphorescent material Ir(ppy) 3 lead to IOLED with a current efficiency of 50 cd/A and power efficiency of 24 lm/W at 100 cd/m2. The average transmittance exceeds 80 % in the visible region. The on-set voltage for light emission is lower than 3 V. In addition, by vertical stacking we achieved a very high current efficiency of more than 70 cd/A for transparent IOLED.

  17. Semi-transparent inverted organic solar cells

    NASA Astrophysics Data System (ADS)

    Schmidt, H.; Winkler, T.; Tilgner, M.; Flügge, H.; Schmale, S.; Bülow, T.; Meyer, J.; Johannes, H.-H.; Riedl, T.; Kowalsky, W.

    2009-08-01

    We will present efficient semi-transparent bulk-heterojunction [regioregular of poly(3-hexylthiophene): (6,6)-phenyl C61 butyric acid methyl ester] solar cells with an inverted device architecture. Highly transparent ZnO and TiO2 films prepared by Atomic Layer Deposition are used as cathode interlayers on top of ITO. The topanode consists of a RF-sputtered ITO layer. To avoid damage due to the plasma deposition of this layer, a sputtering buffer layer of MoO3 is used as protection. This concept allows for devices with a transmissivity higher than 60 % for wavelengths 650 nm. The thickness of the MoO3 buffer has been varied in order to study its effect on the electrical properties of the solar cell and its ability to prevent possible damage to the organic active layers upon ITO deposition. Without this buffer or for thin buffers it has been found that device performance is very poor concerning the leakage current, the fill factor, the short circuit current and the power conversion efficiencies. As a reference inverted solar cells with a metal electrode (Al) instead of the ITO-top contact are used. The variation between the PCE of top versus conventional illumination of the semi-transparent cells was also examined and will be interpreted in view of the results of the optical simulation of the dielectric device stack with and without reflection top electrode. Power conversion efficiencies of 2-3 % for the opaque inverted solar cells and 1.5-2.5 % for the semi-transparent devices were obtained under an AM1.5G illumination.

  18. Photocatalytic decomposition of selected estrogens and their estrogenic activity by UV-LED irradiated TiO2 immobilized on porous titanium sheets via thermal-chemical oxidation.

    PubMed

    Arlos, Maricor J; Liang, Robert; Hatat-Fraile, Melisa M; Bragg, Leslie M; Zhou, Norman Y; Servos, Mark R; Andrews, Susan A

    2016-11-15

    The removal of endocrine disrupting compounds (EDCs) remains a big challenge in water treatment. Risks associated with these compounds are not clearly defined and it is important that the water industry has additional options to increase the resiliency of water treatment systems. Titanium dioxide (TiO2) has potential applications for the removal of EDCs from water. TiO2 has been immobilized on supports using a variety of synthesis methods to increase its feasibility for water treatment. In this study, we immobilized TiO2 through the thermal-chemical oxidation of porous titania sheets. The efficiency of the material to degrade target EDCs under UV-LED irradiation was examined under a wide range of pH conditions. A yeast-estrogen screen assay was used to complement chemical analysis in assessing removal efficiency. All compounds but 17β-estradiol were degraded and followed a pseudo first-order kinetics at all pH conditions tested, with pH 4 and pH 11 showing the most and the least efficient treatments respectively. In addition, the total estrogenic activity was substantially reduced even with the inefficient degradation of 17β-estradiol. Additional studies will be required to optimize different treatment conditions, UV-LED configurations, and membrane fouling mitigation measures to make this technology a more viable option for water treatment. PMID:27469042

  19. Characterization of Chitosan Nanofiber Sheets for Antifungal Application

    PubMed Central

    Egusa, Mayumi; Iwamoto, Ryo; Izawa, Hironori; Morimoto, Minoru; Saimoto, Hiroyuki; Kaminaka, Hironori; Ifuku, Shinsuke

    2015-01-01

    Chitosan produced by the deacetylation of chitin is a cationic polymer with antimicrobial properties. In this study, we demonstrate the improvement of chitosan properties by nanofibrillation. Nanofiber sheets were prepared from nanofibrillated chitosan under neutral conditions. The Young’s modulus and tensile strength of the chitosan NF sheets were higher than those of the chitosan sheets prepared from dissolving chitosan in acetic acid. The chitosan NF sheets showed strong mycelial growth inhibition against dermatophytes Microsporum and Trichophyton. Moreover, the chitosan NF sheets exhibited resistance to degradation by the fungi, suggesting potentials long-lasting usage. In addition, surface-deacetylated chitin nanofiber (SDCNF) sheets were prepared. The SDCNF sheet had a high Young’s modulus and tensile strength and showed antifungal activity to dermatophytes. These data indicate that nanofibrillation improved the properties of chitosan. Thus, chitosan NF and SDCNF sheets are useful candidates for antimicrobial materials. PMID:26540046

  20. Transparency in nonlinear frequency conversion

    NASA Astrophysics Data System (ADS)

    Longhi, Stefano

    2016-04-01

    Suppression of wave scattering and the realization of transparency effects in engineered optical media and surfaces have attracted great attention in the past recent years. In this work the problem of transparency is considered for optical wave propagation in a nonlinear dielectric medium with second-order χ(2 ) susceptibility. Because of nonlinear interaction, a reference signal wave at carrier frequency ω1 can exchange power, thus being amplified or attenuated, when phase-matching conditions are satisfied and frequency conversion takes place. Therefore, rather generally the medium is not transparent to the signal wave because of "scattering" in the frequency domain. Here we show that broadband transparency, corresponding to the full absence of frequency conversion in spite of phase matching, can be observed for the signal wave in the process of sum frequency generation whenever the effective susceptibility χ(2 ) along the nonlinear medium is tailored following a suitable spatial apodization profile and the power level of the pump wave is properly tuned. While broadband transparency is observed under such conditions, the nonlinear medium is not invisible owing to an additional effective dispersion for the signal wave introduced by the nonlinear interaction.

  1. 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.

  2. Coherent-state-induced transparency

    NASA Astrophysics Data System (ADS)

    Gogyan, A.; Malakyan, Yu.

    2016-04-01

    We examine electromagnetically induced transparency (EIT) in an ensemble of cold Λ -type atoms induced by a quantum control field in multimode coherent states and compare it with the transparency created by the classical light of the same intensity. We show that the perfect coincidence is achieved only in the case of a single-mode coherent state, whereas the transparency sharply decreases, when the number of the modes exceeds the mean number of control photons in the medium. The origin of the effect is the modification of photon statistics in the control field with increasing the number of the modes that weakens its interaction with atoms resulting in a strong probe absorption. For the same reason, the probe pulse transforms from EIT-based slow light into superluminal propagation caused by the absorption.

  3. Novel transparent electrodes allow sustainable production of electronic devices

    SciTech Connect

    Constant, Kristen

    2010-12-27

    -particle-count clean-room facilities and multimillion-dollar equipment. On the other hand, the novel process we developed uses a method that makes use of polymer molds and standard deposition techniques in an ambient laboratory environment. The final structure consists of tall ribbons of metal (standing on edge) that are so thin that they do not block light but are very good conductors. The advantage of this design is that it avoids the competition between conductivity and transparency inherent in transparent oxide electrodes. By making the structure taller, conductivity can be increased without impacting transparency. We have measured both electrical conductivity and transparency for these structures. We performed two-wire electrical measurements to quantify the structures resistance using metal contacts deposited on each end. The total sample area was 4 x 4mm{sup 2}. We measured a resistance of structures with 40nm gold sidewalls of 7.3{Omega}, which is lower than that of ITO glass (which has a sheet resistance around 10O/square). We investigated the structures optical properties based on both specular- and total-transmission measurements. Specular transmission is measured by collecting the transmitted light at normal incidence, while total transmission is obtained by collecting transmitted light at normal incidence and diffracted light using an integrating sphere. Figure 3 shows the total transmission of a grating with 40nm gold or silver sidewalls on a glass substrate compared to that of ITO. Additionally, the transparency changes very little within 30{sup o} off normal incidence. This high visible-light transmission of our metal-patterned structures is very promising for their application as transparent electrodes, because most visible light was allowed to propagate through the patterned metallic/polymeric structures. Researchers in our group continue to refine the fabrication methods and are investigating methods to make large-scale structures for use in a variety of

  4. Synthesis of Oxidation-Resistant Cupronickel Nanowires for Transparent Conducting Nanowire Networks

    SciTech Connect

    Rathmall, Aaron; Nguyen, Minh; Wiley, Benjamin J

    2012-01-01

    Nanowires of copper can be coated from liquids to create flexible, transparent conducting films that can potentially replace the dominant transparent conductor, indium tin oxide, in displays, solar cells, organic light-emitting diodes, and electrochromic windows. One issue with these nanowire films is that copper is prone to oxidation. It was hypothesized that the resistance to oxidation could be improved by coating copper nanowires with nickel. This work demonstrates a method for synthesizing copper nanowires with nickel shells as well as the properties of cupronickel nanowires in transparent conducting films. Time- and temperature-dependent sheet resistance measurements indicate that the sheet resistance of copper and silver nanowire films will double after 3 and 36 months at room temperature, respectively. In contrast, the sheet resistance of cupronickel nanowires containing 20 mol % nickel will double in about 400 years. Coating copper nanowires to a ratio of 2:1 Cu:Ni gave them a neutral gray color, making them more suitable for use in displays and electrochromic windows. These properties, and the fact that copper and nickel are 1000 times more abundant than indium or silver, make cupronickel nanowires a promising alternative for the sustainable, efficient production of transparent conductors.

  5. Synthesis of oxidation-resistant cupronickel nanowires for transparent conducting nanowire networks.

    PubMed

    Rathmell, Aaron R; Nguyen, Minh; Chi, Miaofang; Wiley, Benjamin J

    2012-06-13

    Nanowires of copper can be coated from liquids to create flexible, transparent conducting films that can potentially replace the dominant transparent conductor, indium tin oxide, in displays, solar cells, organic light-emitting diodes, and electrochromic windows. One issue with these nanowire films is that copper is prone to oxidation. It was hypothesized that the resistance to oxidation could be improved by coating copper nanowires with nickel. This work demonstrates a method for synthesizing copper nanowires with nickel shells as well as the properties of cupronickel nanowires in transparent conducting films. Time- and temperature-dependent sheet resistance measurements indicate that the sheet resistance of copper and silver nanowire films will double after 3 and 36 months at room temperature, respectively. In contrast, the sheet resistance of cupronickel nanowires containing 20 mol % nickel will double in about 400 years. Coating copper nanowires to a ratio of 2:1 Cu:Ni gave them a neutral gray color, making them more suitable for use in displays and electrochromic windows. These properties, and the fact that copper and nickel are 1000 times more abundant than indium or silver, make cupronickel nanowires a promising alternative for the sustainable, efficient production of transparent conductors. PMID:22642652

  6. Coseismic Faulting and Folding in an Active Thrust Sheet over Multiple Rupture Cycles Resolved by Integrating Surface and Subsurface Records of Earthquake Deformation

    NASA Astrophysics Data System (ADS)

    Stockmeyer, J. M.; Shaw, J. H.; Brown, N.; Rhodes, E. J.; Wang, M.; Lavin, L. C.; Guan, S.

    2015-12-01

    Many recent thrust fault earthquakes have involved coseismic surface faulting and folding, revealing the complex nature of surface deformation in active thrust sheets. In this study, we characterize deformation along the active Southern Junggar Thrust (SJT) in the Junggar basin, NW China - which sourced the 1906 M8 Manas earthquake - to gain insight into how fault slip at depth is partitioned between faulting and folding strains at Earth's surface by integrating deformed terrace records, subsurface geophysical data, and luminescence geochronology. Using a 1-m digital elevation model and field surveys, we have mapped the precise geometries of fluvial terraces across the entire Tugulu anticline, which lies in the hanging wall of the SJT. These profiles reveal progressive uplift of several terraces along prominent fault scarps where the SJT is surface-emergent. Similarly aged terraces are folded in the backlimb of the Tugulu fold, providing a sequential record of surface folding. These folded terraces are progressively rotated such that the oldest terraces are dipping much steeper than younger terraces within the same fold limb. Using 2- and 3-D seismic reflection data, we integrate subsurface deformation constraints with records of surface strain. Structural interpretations of these seismic data define the geometry of the SJT and reveal that folding is localized across synclinal bends along the SJT. We evaluate a range of distinct fault-related fold models (e.g. fault-bend folding, shear fault-bend folding) to assess which structural style best describes the geometries of the subsurface and surface fold patterns. By doing so, we have the opportunity to directly relate surface fault slip measures from terrace folding and uplift to total fault slip at depth. This integration of surface and subsurface deformation - combined with constraints on terrace ages from post-IR IRSL geochronology - allows us to characterize how fault slip and seismic moment are partitioned

  7. Synthesizing a Healable Stretchable Transparent Conductor.

    PubMed

    Li, Junpeng; Qi, Shuhua; Liang, Jiajie; Li, Lu; Xiong, Yan; Hu, Wei; Pei, Qibing

    2015-07-01

    We report the first demonstration of a healable stretchable transparent electrode comprising a silver nanowire (AgNW) network and poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT) hybrid layer in the surface of a Diels-Alder elastomer substrate. The thin PEDOT layer solders the silver nanowires and confines the nanowire network in the substrate surface. The bonding between the nanowires and PEDOT is tuned via ethanol-water wetting, which allows for large-strain prestretching of the AgNW network. The composite electrode prepared via such a wetting and prestretching treatment has a figure-of-merit sheet resistance of 15 ohm/sq with 78% transmittance at 550 nm and can be stretched by 100% strain. Damages caused by razor blade cutting on the conductive surface could be healed, and the damaging-healing could be repeated for three times at the same location. The healed electrode exhibits similar resistance-strain response as the fresh electrode because of the PEDOT layer being capable of circumventing broken nanowire sites. Fatigue-induced damages after 100 cycles of 60% strain can also be healed by simple heating. PMID:26062004

  8. Cu Mesh for Flexible Transparent Conductive Electrodes

    PubMed Central

    Kim, Won-Kyung; Lee, Seunghun; Hee Lee, Duck; Hee Park, In; Seong Bae, Jong; Woo Lee, Tae; Kim, Ji-Young; Hun Park, Ji; Chan Cho, Yong; Ryong Cho, Chae; Jeong, Se-Young

    2015-01-01

    Copper electrodes with a micromesh/nanomesh structure were fabricated on a polyimide substrate using UV lithography and wet etching to produce flexible transparent conducting electrodes (TCEs). Well-defined mesh electrodes were realized through the use of high-quality Cu thin films. The films were fabricated using radio-frequency (RF) sputtering with a single-crystal Cu target—a simple but innovative approach that overcame the low oxidation resistance of ordinary Cu. Hybrid Cu mesh electrodes were fabricated by adding a capping layer of either ZnO or Al-doped ZnO. The sheet resistance and the transmittance of the electrode with an Al-doped ZnO capping layer were 6.197 ohm/sq and 90.657%, respectively, and the figure of merit was 60.502 × 10–3/ohm, which remained relatively unchanged after thermal annealing at 200 °C and 1,000 cycles of bending. This fabrication technique enables the mass production of large-area flexible TCEs, and the stability and high performance of Cu mesh hybrid electrodes in harsh environments suggests they have strong potential for application in smart displays and solar cells. PMID:26039977

  9. Cu mesh for flexible transparent conductive electrodes.

    PubMed

    Kim, Won-Kyung; Lee, Seunghun; Hee Lee, Duck; Hee Park, In; Seong Bae, Jong; Woo Lee, Tae; Kim, Ji-Young; Hun Park, Ji; Chan Cho, Yong; Ryong Cho, Chae; Jeong, Se-Young

    2015-01-01

    Copper electrodes with a micromesh/nanomesh structure were fabricated on a polyimide substrate using UV lithography and wet etching to produce flexible transparent conducting electrodes (TCEs). Well-defined mesh electrodes were realized through the use of high-quality Cu thin films. The films were fabricated using radio-frequency (RF) sputtering with a single-crystal Cu target--a simple but innovative approach that overcame the low oxidation resistance of ordinary Cu. Hybrid Cu mesh electrodes were fabricated by adding a capping layer of either ZnO or Al-doped ZnO. The sheet resistance and the transmittance of the electrode with an Al-doped ZnO capping layer were 6.197 ohm/sq and 90.657%, respectively, and the figure of merit was 60.502 × 10(-3)/ohm, which remained relatively unchanged after thermal annealing at 200 °C and 1,000 cycles of bending. This fabrication technique enables the mass production of large-area flexible TCEs, and the stability and high performance of Cu mesh hybrid electrodes in harsh environments suggests they have strong potential for application in smart displays and solar cells. PMID:26039977

  10. Partial transparency of compressed wood

    NASA Astrophysics Data System (ADS)

    Sugimoto, Hiroyuki; Sugimori, Masatoshi

    2016-05-01

    We have developed novel wood composite with optical transparency at arbitrary region. Pores in wood cells have a great variation in size. These pores expand the light path in the sample, because the refractive indexes differ between constituents of cell and air in lumen. In this study, wood compressed to close to lumen had optical transparency. Because the condition of the compression of wood needs the plastic deformation, wood was impregnated phenolic resin. The optimal condition for high transmission is compression ratio above 0.7.

  11. Experimental observation of heat transparency

    NASA Astrophysics Data System (ADS)

    Zeng, Lunwu; Song, Runxia

    2014-05-01

    In this Letter, we experimentally observed heat diffusion transparency with the heat diffusion device we fabricated, which can measure time-dependent temperature. Utilizing the effective medium theory, we fabricated an isotropic spherical shell with an isotropic spherical core, as well as a multilayer isotropic spherical shell with an isotropic spherical core as neutral inclusions. We measured the temperatures and temperature gradients outside the neutral inclusions with the self-made heat diffusion device and analyzed the heat transparent conditions. The experimental results show that the temperature gradients are parallel and equal outside the neutral inclusion, and the iso-temperature lines are also parallel outside the neutral inclusion.

  12. Switching from "absorption within transparency" to "transparency within transparency" in an electromagnetically induced absorption dominated transition.

    PubMed

    Dahl, Katrin; Molella, Luca Spani; Rinkleff, Rolf-Hermann; Danzmann, Karsten

    2008-05-01

    The absorption of a resonant coupling laser driving a closed degenerate two-level system in an atomic cesium beam was investigated as a function of the detuning of a second laser probing the same transition. The measurements were performed for four different polarization combinations of the two laser beams. Except for the beams of counterrotating polarizations all coupling-laser absorption profiles showed "absorption within transparency," i.e., the absorption in the region around the two-photon resonance was smaller than the absorption corresponding to the one-photon transition induced by the coupling laser, and an extra absorption peak was observed on this curve at the two-photon resonance. With regard to the beams of counterrotating polarizations we observed a switch from absorption within transparency to "transparency within transparency" when the probe-laser power exceeded the constant coupling-laser power. In other words, the cesium ensemble became mostly transparent to the coupling-laser beam at the two-photon resonance. PMID:18451960

  13. Transparent white organic light emitting diodes with improved cathode transparency

    NASA Astrophysics Data System (ADS)

    Lee, Jeong-Ik; Lee, Jonghee; Lee, Joowon; Shin, Jae-Heon; Hwang, Chi-Sun; Chu, Hye Yong

    2009-08-01

    We have fabricated transparent white organic light emitting diode (WOLED) for lighting application based on a hybrid white OLED and a phosphorescence white OLED. For the hybrid WOLED, a blue fluorescence emitting layer (FLEML) and green and red phosphorescence emitting layers (PH-EMLs) have been used in the device structure of ITO/hole transporting layer (HTL)/PH-EMLs/interlayer/FL-EML/ETL/LiF/Al. The balanced emissions from the FLEML and the PH-EMLs have been obtained by using appropriate carrier (hole) trapping effects in the PH-EMLs, which resulted in external and power efficiencies of 15 % and 27 lm/W, respectively, at a luminance of 1000 cd/m2 without any out-coupling enhancement. The Commission Internationale de L'Eclairage (CIE) coordinates of this hybrid WOLED is (0.43,0.44) with color rendering index (CRI) of 80 and correlated color temperature (CCT) of 3200 K, respectively, in the bottom emission structure. Based on this hybrid WOLED, we established highly efficient transparent WOLED by introduction of a transparent cathode, and obtained over 19 lm/W of power efficiency at a total luminance of 1000 cd/m2 as well as over 60 % of transmittance at 550 nm with the conventional glass encapsulation. Moreover, when the phosphorescent white OLED was combined with a transparent cathode, the power efficiency was reached up to 24 lm/W of power efficiency at a total luminance of 1000 cd/m2.

  14. 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.

  15. Metal Nanowires: Synthesis, Processing, and Structure-Property Relationships in the Context of Flexible Transparent Conducting Films

    NASA Astrophysics Data System (ADS)

    Rathmell, Aaron R.

    The demand for flat-panel televisions, e-readers, smart-phones, and touch-screens has been increasing over the past few years and will continue to increase for the foreseeable future. Each of these devices contains a transparent conductor, which is usually indium tin oxide (ITO) because of its high transparency and low sheet resistance. ITO films, however, are brittle, expensive, and difficult to deposit, and because of these problems, alternative transparent electrodes are being studied. One cheap and flexible alternative to ITO is films of randomly oriented copper nanowires. We have developed a synthesis to make long, thin, and well-dispersed copper nanowires that can be suspended in an ink and coated onto a substrate to make flexible transparent films. These films are then made conductive by annealing in a hydrogen atmosphere or by a solution processing technique that can be done in air at room temperature. The resulting flexible transparent conducting films display transparencies and sheet resistance values comparable to ITO. Since it is well known that copper oxidizes, we also developed a synthesis to coat the copper nanowires with a layer of nickel in solution. Our measurements indicated that copper nanowires would double their sheet resistance in 3 months, but the sheet resistance of cupronickel nanowire films containing 20 mole% nickel will double in about 400 years. The addition of nickel to the copper nanowires also gave the film a more neutral grey appearance. The nickel coating can also be applied to the copper nanowires after the film is formed via an electroless plating method. To further optimize the properties of our transparent conductors we developed a framework to understand how the dimensions and area coverage of the nanowires affect the overall film properties. To quantify the effect of length on the sheet resistance and transmittance, wires with different lengths but the same diameter were synthesized to make transparent conducting films and

  16. Apparatus To Test Solvent Stress Crazing Of Polymer Sheets

    NASA Technical Reports Server (NTRS)

    Simpson, Gareth L.; Hoult, William S.

    1996-01-01

    Apparatus simple to make, operate, and maintain used to determine abilities of transparent polymeric seal materials to resist stress crazing when exposed to various cleaning solvents. Includes pulleys, cable, and weights to apply constant tension to specimen sheet immersed in test fluid in glass vessel. Provides visual observation of specimen at any time during test and ease of removal of fluid via drain port at bottom of glass vessel.

  17. Tailored silver grid as transparent electrodes directly written by femtosecond laser

    NASA Astrophysics Data System (ADS)

    Zhao, Yuan-Yuan; Zheng, Mei-Ling; Dong, Xian-Zi; Jin, Feng; Liu, Jie; Ren, Xue-Liang; Duan, Xuan-Ming; Zhao, Zhen-Sheng

    2016-05-01

    We present the design and realization of silver grid transparent electrodes (SGTEs) easily fabricated by femtosecond laser direct writing of silver aqueous solution. The fabricated SGTEs with a sheet resistance down to 47 Ω/□ and optical transmittance up to 93% are demonstrated. These sheet resistance and transmittance values are comparable to commercially available indium tin oxide. High uniform morphology of the directly written SGTEs results in the ultra-stable tailored performance parameter at electronic and optical fields. The sheet resistance and transmittance can be tailored precisely by manipulating the filling fraction of the uniform SGTEs. This study provides an approach for creating SGTEs in a controllable fashion, and the SGTEs exhibit high transmittance and low sheet resistance, which could open up new avenues towards widespread application in electronics, photovoltaics, and optoelectronics.

  18. Correlated metals as transparent conductors.

    PubMed

    Zhang, Lei; Zhou, Yuanjun; Guo, Lu; Zhao, Weiwei; Barnes, Anna; Zhang, Hai-Tian; Eaton, Craig; Zheng, Yuanxia; Brahlek, Matthew; Haneef, Hamna F; Podraza, Nikolas J; Chan, Moses H W; Gopalan, Venkatraman; Rabe, Karin M; Engel-Herbert, Roman

    2016-02-01

    The fundamental challenge for designing transparent conductors used in photovoltaics, displays and solid-state lighting is the ideal combination of high optical transparency and high electrical conductivity. Satisfying these competing demands is commonly achieved by increasing carrier concentration in a wide-bandgap semiconductor with low effective carrier mass through heavy doping, as in the case of tin-doped indium oxide (ITO). Here, an alternative design strategy for identifying high-conductivity, high-transparency metals is proposed, which relies on strong electron-electron interactions resulting in an enhancement in the carrier effective mass. This approach is experimentally verified using the correlated metals SrVO3 and CaVO3, which, despite their high carrier concentration (>2.2 × 10(22) cm(-3)), have low screened plasma energies (<1.33 eV), and demonstrate excellent performance when benchmarked against ITO. A method is outlined to rapidly identify other candidates among correlated metals, and strategies are proposed to further enhance their performance, thereby opening up new avenues to develop transparent conductors. PMID:26657329

  19. Correlated metals as transparent conductors

    NASA Astrophysics Data System (ADS)

    Zhang, Lei; Zhou, Yuanjun; Guo, Lu; Zhao, Weiwei; Barnes, Anna; Zhang, Hai-Tian; Eaton, Craig; Zheng, Yuanxia; Brahlek, Matthew; Haneef, Hamna F.; Podraza, Nikolas J.; Chan, Moses H. W.; Gopalan, Venkatraman; Rabe, Karin M.; Engel-Herbert, Roman

    2016-02-01

    The fundamental challenge for designing transparent conductors used in photovoltaics, displays and solid-state lighting is the ideal combination of high optical transparency and high electrical conductivity. Satisfying these competing demands is commonly achieved by increasing carrier concentration in a wide-bandgap semiconductor with low effective carrier mass through heavy doping, as in the case of tin-doped indium oxide (ITO). Here, an alternative design strategy for identifying high-conductivity, high-transparency metals is proposed, which relies on strong electron-electron interactions resulting in an enhancement in the carrier effective mass. This approach is experimentally verified using the correlated metals SrVO3 and CaVO3, which, despite their high carrier concentration (>2.2 × 1022 cm-3), have low screened plasma energies (<1.33 eV), and demonstrate excellent performance when benchmarked against ITO. A method is outlined to rapidly identify other candidates among correlated metals, and strategies are proposed to further enhance their performance, thereby opening up new avenues to develop transparent conductors.

  20. Projection transparencies from printed material

    NASA Technical Reports Server (NTRS)

    Grunewald, L. S.; Nickerson, T. B.

    1968-01-01

    Method for preparing project transparencies, or view graphs, permits the use of almost any expendable printed material, pictures, charts, or text, in unlimited color or black and white. The method can be accomplished by either of two techniques, with a slight difference in materials.

  1. Could Transparency Bring Economic Diversity?

    ERIC Educational Resources Information Center

    Kahlenberg, Richard D.

    2007-01-01

    The Spellings Commission report calls for greater access to higher education for low- and moderate-income students, greater transparency in the way higher education works and greater accountability for producing results. These recommendations are all significant in their own right, but the three concepts also converge to provide powerful support…

  2. A novel system of electrodes transparent to ultrasound for simultaneous detection of myoelectric activity and B-mode ultrasound images of skeletal muscles

    PubMed Central

    Vieira, T. M. M.; Loram, I. D.; Merletti, R.; Hodson-Tole, E. F.

    2013-01-01

    Application of two-dimensional surface electrode arrays can provide a means of mapping motor unit action potentials on the skin surface above a muscle. The resulting muscle tissue displacement can be quantified, in a single plane, using ultrasound (US) imaging. Currently, however, it is not possible to simultaneously map spatio-temporal propagation of activation and resulting tissue strain. In this paper, we developed and tested a material that will enable concurrent measurement of two-dimensional surface electromyograms (EMGs) with US images. Specific protocols were designed to test the compatibility of this new electrode material, both with EMG recording and with US analysis. Key results indicate that, for this new electrode material, 1) the electrode-skin impedance is similar to that of arrays of electrodes reported in literature; 2) the reflection of US at the electrode-skin interface is negligible; 3) the likelihood of observing missing contacts, short-circuits, and artifacts in EMGs is not affected by the US probe; 4) movement of tissues sampled by US can be tracked accurately. We, therefore, conclude this approach will facilitate multimodal imaging of muscle to provide new spatio-temporal information regarding electromechanical function of muscle. This is relevant to basic physiology-biomechanics of active and passive force transmission through and between muscles, of motor unit spatio-temporal activity patterns, of their variation with architecture and task-related function, and of their adaptation with aging, training-exercise-disuse, neurological disease, and injury. PMID:23908313

  3. A novel system of electrodes transparent to ultrasound for simultaneous detection of myoelectric activity and B-mode ultrasound images of skeletal muscles.

    PubMed

    Botter, A; Vieira, T M M; Loram, I D; Merletti, R; Hodson-Tole, E F

    2013-10-15

    Application of two-dimensional surface electrode arrays can provide a means of mapping motor unit action potentials on the skin surface above a muscle. The resulting muscle tissue displacement can be quantified, in a single plane, using ultrasound (US) imaging. Currently, however, it is not possible to simultaneously map spatio-temporal propagation of activation and resulting tissue strain. In this paper, we developed and tested a material that will enable concurrent measurement of two-dimensional surface electromyograms (EMGs) with US images. Specific protocols were designed to test the compatibility of this new electrode material, both with EMG recording and with US analysis. Key results indicate that, for this new electrode material, 1) the electrode-skin impedance is similar to that of arrays of electrodes reported in literature; 2) the reflection of US at the electrode-skin interface is negligible; 3) the likelihood of observing missing contacts, short-circuits, and artifacts in EMGs is not affected by the US probe; 4) movement of tissues sampled by US can be tracked accurately. We, therefore, conclude this approach will facilitate multimodal imaging of muscle to provide new spatio-temporal information regarding electromechanical function of muscle. This is relevant to basic physiology-biomechanics of active and passive force transmission through and between muscles, of motor unit spatio-temporal activity patterns, of their variation with architecture and task-related function, and of their adaptation with aging, training-exercise-disuse, neurological disease, and injury. PMID:23908313

  4. Electronic Durability of Flexible Transparent Films from Type-Specific Single-Wall Carbon Nanotubes

    SciTech Connect

    Harris, J; Iyer, S; Bernhardt, A; Huh, JY; Hudson, S; Fagan, J; Hobbie, E.

    2011-12-11

    The coupling between mechanical flexibility and electronic performance is evaluated for thin films of metallic and semiconducting single-wall carbon nanotubes (SWCNTs) deposited on compliant supports. Percolated networks of type-purified SWCNTs are assembled as thin conducting coatings on elastic polymer substrates, and the sheet resistance is measured as a function of compression and cyclic strain through impedance spectroscopy. The wrinkling topography, microstructure and transparency of the films are independently characterized using optical microscopy, electron microscopy, and optical absorption spectroscopy. Thin films made from metallic SWCNTs show better durability as flexible transparent conductive coatings, which we attribute to a combination of superior mechanical performance and higher interfacial conductivity.

  5. Electronic durability of flexible transparent films from type-specific single-wall carbon nanotubes.

    PubMed

    Harris, John M; Iyer, Ganjigunte R Swathi; Bernhardt, Anna K; Huh, Ji Yeon; Hudson, Steven D; Fagan, Jeffrey A; Hobbie, Erik K

    2012-01-24

    The coupling between mechanical flexibility and electronic performance is evaluated for thin films of metallic and semiconducting single-wall carbon nanotubes (SWCNTs) deposited on compliant supports. Percolated networks of type-purified SWCNTs are assembled as thin conducting coatings on elastic polymer substrates, and the sheet resistance is measured as a function of compression and cyclic strain through impedance spectroscopy. The wrinkling topography, microstructure and transparency of the films are independently characterized using optical microscopy, electron microscopy, and optical absorption spectroscopy. Thin films made from metallic SWCNTs show better durability as flexible transparent conductive coatings, which we attribute to a combination of superior mechanical performance and higher interfacial conductivity. PMID:22148890

  6. Optimization of Ferroelectric Polymer ∖Graphene Films for Transparent and Flexible Electronics

    NASA Astrophysics Data System (ADS)

    Kahya, Orhan; Wu, Jing; Ni, Guang-Xin; Toh, Chee-Tat; Bae, Sang-Hoon; Ahn, Jong-Hyun; Oezyilmaz, Barbaros

    2013-03-01

    Nonvolatile, electrostatic doping of graphene-based devices with ferroelectric polymers such as Poly (vinylidene fluoride-trifluoroethylene) are promising for realizing ultra-fast, flexible memory devices, nanogenerators and actuators. More recently, the same approach has been shown to provide an alternative route in enabling graphene based transparent electrodes for touch screen applications. Here, we report a systematic study of optimizing the ferroelectric polymer-graphene heterostructure as a function of thickness, various copolymer blends and coating techniques. Optimized films show outstanding mechanical properties, low sheet resistance (~ 100 Ω/sq) and optical transparency levels as high as 96%.

  7. Polymer-assisted direct deposition of uniform carbon nanotube bundle networks for high performance transparent electrodes.

    PubMed

    Hellstrom, Sondra L; Lee, Hang Woo; Bao, Zhenan

    2009-06-23

    Flexible transparent electrodes are crucial for touch screen, flat panel display, and solar cell technologies. While carbon nanotube network electrodes show promise, characteristically poor dispersion properties have limited their practicality. We report that addition of small amounts of conjugated polymer to nanotube dispersions enables straightforward fabrication of uniform network electrodes by spin-coating and simultaneous tuning of parameters such as bundle size and density. After treatment in thionyl chloride, electrodes have sheet resistances competitive with other reported carbon nanotube based transparent electrodes to date. PMID:19422197

  8. Graphene-Based Flexible and Transparent Tunable Capacitors.

    PubMed

    Man, Baoyuan; Xu, Shicai; Jiang, Shouzheng; Liu, Aihua; Gao, Shoubao; Zhang, Chao; Qiu, Hengwei; Li, Zhen

    2015-12-01

    We report a kind of electric field tunable transparent and flexible capacitor with the structure of graphene-Bi1.5MgNb1.5O7 (BMN)-graphene. The graphene films with low sheet resistance were grown by chemical vapor deposition. The BMN thin films were fabricated on graphene by using laser molecular beam epitaxy technology. Compared to BMN films grown on Au, the samples on graphene substrates show better quality in terms of crystallinity, surface morphology, leakage current, and loss tangent. By transferring another graphene layer, we fabricated flexible and transparent capacitors with the structure of graphene-BMN-graphene. The capacitors show a large dielectric constant of 113 with high dielectric tunability of ~40.7 % at a bias field of 1.0 MV/cm. Also, the capacitor can work stably in the high bending condition with curvature radii as low as 10 mm. This flexible film capacitor has a high optical transparency of ~90 % in the visible light region, demonstrating their potential application for a wide range of flexible electronic devices. PMID:26138450

  9. Modified silver nanowire transparent electrodes with exceptional stability against oxidation

    NASA Astrophysics Data System (ADS)

    Idier, J.; Neri, W.; Labrugère, C.; Ly, I.; Poulin, P.; Backov, R.

    2016-03-01

    We report an easy method to prepare thin, flexible and transparent electrodes that show enhanced inertness toward oxidation using modified silver nanowires (Ag NWs). Stabilization is achieved through the adsorption of triphenylphosphine (PPh3) onto the Ag NW hybrid dispersions prior to their 2D organization as transparent electrodes on polyethylene terephtalate (PET) films. After 110 days in air (20 °C) under atmospheric conditions, the transmittance of the PET/Ag NW/PPh3 based films is nearly unchanged, while the transmittance of the PET/Ag NW-based films decreases by about 5%. The sheet resistance increases for both materials as time elapses, but the rate of increase is more than four times slower for films stabilized by PPh3. The improved transmittance and conductivity results in a significantly enhanced stability for the figure of merit σ dc/σ op. This phenomenon is highlighted in highly oxidative nitric acid vapor. The tested stabilized films in such conditions exhibit a decrease to σ dc/σ op of only 38% after 75 min, whereas conventional materials exhibit a relative loss of 71%. In addition, by contrast to other classes of stabilizers, such as polymer or graphene-based encapsulants, PPh3 does not alter the transparency or conductivity of the modified films. While the present films are made by membrane filtration, the stabilization method could be implemented directly in other liquid processes, including industrially scalable ones.

  10. Modified silver nanowire transparent electrodes with exceptional stability against oxidation.

    PubMed

    Idier, J; Neri, W; Labrugère, C; Ly, I; Poulin, P; Backov, R

    2016-03-11

    We report an easy method to prepare thin, flexible and transparent electrodes that show enhanced inertness toward oxidation using modified silver nanowires (Ag NWs). Stabilization is achieved through the adsorption of triphenylphosphine (PPh3) onto the Ag NW hybrid dispersions prior to their 2D organization as transparent electrodes on polyethylene terephtalate (PET) films. After 110 days in air (20 °C) under atmospheric conditions, the transmittance of the PET/Ag NW/PPh3 based films is nearly unchanged, while the transmittance of the PET/Ag NW-based films decreases by about 5%. The sheet resistance increases for both materials as time elapses, but the rate of increase is more than four times slower for films stabilized by PPh3. The improved transmittance and conductivity results in a significantly enhanced stability for the figure of merit σ dc/σ op. This phenomenon is highlighted in highly oxidative nitric acid vapor. The tested stabilized films in such conditions exhibit a decrease to σ dc/σ op of only 38% after 75 min, whereas conventional materials exhibit a relative loss of 71%. In addition, by contrast to other classes of stabilizers, such as polymer or graphene-based encapsulants, PPh3 does not alter the transparency or conductivity of the modified films. While the present films are made by membrane filtration, the stabilization method could be implemented directly in other liquid processes, including industrially scalable ones. PMID:26866415

  11. Silicon sheet technologies

    SciTech Connect

    Ciszek, T.F.

    1982-09-01

    A classification of silicon sheet growth methods by meniscus geometry permits them to be discussed in three groups: short meniscus techniques, high meniscus techniques, and extended meniscus or large solid/liquid interface area techniques. A second parameter, meniscus shaper interaction with the liquid silicon, is also instrumental in determining the characteristics of the various sheet processes. The current status of each process is discussed in the context of meniscus geometry and shaper/melt interaction. One aspect of sheet growth, surface area generation rate, is quantitatively compared with combined ingot growth and wafering surface area generation rates.

  12. Microcomponent sheet architecture

    DOEpatents

    Wegeng, R.S.; Drost, M.K..; McDonald, C.E.

    1997-03-18

    The invention is a microcomponent sheet architecture wherein macroscale unit processes are performed by microscale components. The sheet architecture may be a single laminate with a plurality of separate microcomponent sections or the sheet architecture may be a plurality of laminates with one or more microcomponent sections on each laminate. Each microcomponent or plurality of like microcomponents perform at least one unit operation. A first laminate having a plurality of like first microcomponents is combined with at least a second laminate having a plurality of like second microcomponents thereby combining at least two unit operations to achieve a system operation. 14 figs.

  13. Microcomponent sheet architecture

    DOEpatents

    Wegeng, Robert S.; Drost, M. Kevin; McDonald, Carolyn E.

    1997-01-01

    The invention is a microcomponent sheet architecture wherein macroscale unit processes are performed by microscale components. The sheet architecture may be a single laminate with a plurality of separate microcomponent sections or the sheet architecture may be a plurality of laminates with one or more microcomponent sections on each laminate. Each microcomponent or plurality of like microcomponents perform at least one unit operation. A first laminate having a plurality of like first microcomponents is combined with at least a second laminate having a plurality of like second microcomponents thereby combining at least two unit operations to achieve a system operation.

  14. Transparent self-cleaning dust shield

    DOEpatents

    Mazumder, Malay K.; Sims, Robert A.; Wilson, James D.

    2005-06-28

    A transparent electromagnetic shield to protect solar panels and the like from dust deposition. The shield is a panel of clear non-conducting (dielectric) material with embedded parallel electrodes. The panel is coated with a semiconducting film. Desirably the electrodes are transparent. The electrodes are connected to a single-phase AC signal or to a multi-phase AC signal that produces a travelling electromagnetic wave. The electromagnetic field produced by the electrodes lifts dust particles away from the shield and repels charged particles. Deposited dust particles are removed when the electrodes are activated, regardless of the resistivity of the dust. Electrostatic charges on the panel are discharged by the semiconducting film. When used in conjunction with photovoltaic cells, the power for the device may be obtained from the cells themselves. For other surfaces, such as windshields, optical windows and the like, the power must be derived from an external source. One embodiment of the invention employs monitoring and detection devices to determine when the level of obscuration of the screen by dust has reached a threshold level requiring activation of the dust removal feature.

  15. Optically transparent multi-suction electrode arrays

    PubMed Central

    Nagarah, John M.; Stowasser, Annette; Parker, Rell L.; Asari, Hiroki; Wagenaar, Daniel A.

    2015-01-01

    Multielectrode arrays (MEAs) allow for acquisition of multisite electrophysiological activity with submillisecond temporal resolution from neural preparations. The signal to noise ratio from such arrays has recently been improved by substrate perforations that allow negative pressure to be applied to the tissue; however, such arrays are not optically transparent, limiting their potential to be combined with optical-based technologies. We present here multi-suction electrode arrays (MSEAs) in quartz that yield a substantial increase in the detected number of units and in signal to noise ratio from mouse cortico-hippocampal slices and mouse retina explants. This enables the visualization of stronger cross correlations between the firing rates of the various sources. Additionally, the MSEA's transparency allows us to record voltage sensitive dye activity from a leech ganglion with single neuron resolution using widefield microscopy simultaneously with the electrode array recordings. The combination of enhanced electrical signals and compatibility with optical-based technologies should make the MSEA a valuable tool for investigating neuronal circuits. PMID:26539078

  16. Making It with Media. Transparency Design.

    ERIC Educational Resources Information Center

    Beasley, Augie E.; Palmer, Carolyn G.

    This guide to the design and production of overhead transparencies begins with a matching test of related terminology and definitions. Introductory materials include an outline of advantages and disadvantages of using transparencies; a list of recommended uses of the overhead and transparencies; tips for overhead presentations; general…

  17. Transparent metals for ultrabroadband electromagnetic waves.

    PubMed

    Fan, Ren-Hao; Peng, Ru-Wen; Huang, Xian-Rong; Li, Jia; Liu, Yongmin; Hu, Qing; Wang, Mu; Zhang, Xiang

    2012-04-17

    Making metals transparent, which could lead to fascinating applications, has long been pursued. Here we demonstrate that with narrow slit arrays metallic plates become transparent for extremely broad bandwidths; the high transmission efficiency is insensitive to the metal thickness. This work provides a guideline to develop novel devices, including transparent conducting panels, broadband metamaterials, and antireflective solar cells. PMID:22431279

  18. Transparency and Oversight in Local Wellness Policies

    ERIC Educational Resources Information Center

    Chriqui, Jamie F.; Chaloupka, Frank J.

    2011-01-01

    Background: Advocates have called for increased wellness policy transparency and oversight through the use of health advisory councils. This study examines (1) wellness policy transparency, (2) advisory council requirements, (3) factors associated with each, and (4) whether transparency or advisory council requirements are indicative of a stronger…

  19. Overhead transparency skills for perioperative nurse educators.

    PubMed

    Beitz, J M

    1996-10-01

    Successful design of creative overhead transparencies should be part of the instructional repertoire of perioperative educators. Personal computers and user-friendly software have revolutionized overhead transparencies' dynamic, imaginative production. This article reviews the advantages and disadvantages of overhead projection, presents practical suggestions for generating and using transparencies, and displays computer designed examples. PMID:8893964

  20. High-Performance Fully Nanostructured Photodetector with Single-Crystalline CdS Nanotubes as Active Layer and Very Long Ag Nanowires as Transparent Electrodes.

    PubMed

    An, Qinwei; Meng, Xianquan; Sun, Pan

    2015-10-21

    Long and single-crystalline CdS nanotubes (NTs) have been prepared via a physical evaporation process. A metal-semiconductor-metal full-nanostructured photodetector with CdS NTs as active layer and Ag nanowires (NWs) of low resistivity and high transmissivity as electrodes has been fabricated and characterized. The CdS NTs-based photodetectors exhibit high performance, such as lowest dark currents (0.19 nA) and high photoresponse ratio (Ilight/Idark ≈ 4016) (among CdS nanostructure network photodetectors and NTs netwok photodetectors reported so far) and very low operation voltages (0.5 V). The photoconduction mechanism, including the formation of a Schottky barrier at the interface of Ag NW and CdS NTs and the effect of oxygen adsorption process on the Schottky barrier has also been provided in detail based on the studies of CdS NTs photodetector in air and vacuum. Furthermore, CdS NTs photodetector exhibits an enhanced photosensitivity as compared with CdS NWs photodetector. The enhancement in performance is dependent on the larger surface area of NTs adsorbing more oxygen in air and the microcavity structure of NTs with higher light absorption efficiency and external quantum efficiency. It is believed that CdS NTs can potentially be useful in the designs of 1D CdS-based optoelectronic devices and solar cells. PMID:26457660

  1. Solution-processed silver nanowire/indium-tin-oxide nanoparticle hybrid transparent conductors with high thermal stability.

    PubMed

    Hong, Sung-Jei; Kim, Jong-Woong; Kim, Yong-Hoon

    2014-12-01

    In this study, solution-processed hybrid structure transparent conductors consisting of silver nanowires (AgNWs) and indium-tin-oxide nanoparticle (ITO-NP) layers are investigated. Fabricated transparent conductors had stacked structures of ITO-NP/AgNW and ITO-NP/AgNW/ITO-NP, and a successful integration was possible on glass substrates. Compared to a single-layered ITO-NP film which has a sheet resistance value of 1.31 k Ω/⟂, a remarkable enhancement in sheet resistance was achieved from the hybrid structures, showing sheet resistance values of 44.74 Ω/⟂ and 28.07 Ω/⟂ for ITO-NP/AgNW and ITO-NP/AgNW/ITO-NP structures, respectively. In addition, the ITO-NP/AgNW/ITO-NP triple-layered transparent conductor showed greatly enhanced thermal stability in terms of sheet resistance and transmittance against a high-temperature environment up to 300 degrees C. Based on these results, it can be suggested that the hybrid structure has advantages of enhancing both electrical properties of ITO-NP layer and thermal stability of AgNW layer, and we believe the hybrid structure transparent conductors can be a suitable option for applications which require high electrical conductivity, transmittance, and thermal stability. PMID:25971091

  2. Bromination of graphene: a new route to making high performance transparent conducting electrodes with low optical losses (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Mansour, Ahmed E.; Amassian, Aram; Tanielian, Minas H.

    2015-09-01

    The high optical transmittance, electrical conductivity, flexibility and chemical stability of graphene have triggered great interest in its application as a transparent conducting electrode material and as a potential replacement for indium doped tin oxide. However, currently available large scale production methods such as chemical vapor deposition produce polycrystalline graphene, and require additional transfer process which further introduces defects and impurities resulting in a significant increase in its sheet resistance. Doping of graphene with foreign atoms has been a popular route for reducing its sheet resistance which typically comes at a significant loss in optical transmission. Herein, we report the successful bromine doping of graphene resulting in air-stable transparent conducting electrodes with up to 80% reduction of sheet resistance reaching ~180 Ω/ at the cost of 2-3% loss of optical transmission in case of few layer graphene and 0.8% in case of single layer graphene. The remarkably low tradeoff in optical transparency leads to the highest enhancements in figure of merit reported thus far. Furthermore, our results show a controlled increase in the workfunction up to 0.3 eV with the bromine content. These results should help pave the way for further development of graphene as potentially a highly transparent substitute to other transparent conducting electrodes in optoelectronic devices.

  3. Gyromagnetically induced transparency of metasurfaces.

    PubMed

    Mousavi, S Hossein; Khanikaev, Alexander B; Allen, Jeffery; Allen, Monica; Shvets, Gennady

    2014-03-21

    We demonstrate that the presence of a (gyro) magnetic substrate can produce an analog of electromagnetically induced transparency in Fano-resonant metamolecules. The simplest implementation of such gyromagnetically induced transparency (GIT) in a metasurface, comprised of an array of resonant antenna pairs placed on a gyromagnetic substrate and illuminated by a normally incident electromagnetic wave, is analyzed. Time reversal and spatial inversion symmetry breaking introduced by the dc magnetization makes metamolecules bianisotropic. This causes Fano interference between the otherwise uncoupled symmetric and antisymmetric resonances of the metamolecules giving rise to a sharp transmission peak through the otherwise reflective metasurface. We show that, for an oblique wave incidence, one-way GIT can be achieved by the combination of spatial dispersion and gyromagnetic effect. These theoretically predicted phenomena pave the way to nonreciprocal switches and isolators that can be dynamically controlled by electric currents. PMID:24702414

  4. Gyromagnetically Induced Transparency of Metasurfaces

    NASA Astrophysics Data System (ADS)

    Mousavi, S. Hossein; Khanikaev, Alexander B.; Allen, Jeffery; Allen, Monica; Shvets, Gennady

    2014-03-01

    We demonstrate that the presence of a (gyro) magnetic substrate can produce an analog of electromagnetically induced transparency in Fano-resonant metamolecules. The simplest implementation of such gyromagnetically induced transparency (GIT) in a metasurface, comprised of an array of resonant antenna pairs placed on a gyromagnetic substrate and illuminated by a normally incident electromagnetic wave, is analyzed. Time reversal and spatial inversion symmetry breaking introduced by the dc magnetization makes metamolecules bianisotropic. This causes Fano interference between the otherwise uncoupled symmetric and antisymmetric resonances of the metamolecules giving rise to a sharp transmission peak through the otherwise reflective metasurface. We show that, for an oblique wave incidence, one-way GIT can be achieved by the combination of spatial dispersion and gyromagnetic effect. These theoretically predicted phenomena pave the way to nonreciprocal switches and isolators that can be dynamically controlled by electric currents.

  5. Preparation and characterization of transparent hydrophilic photocatalytic TiO2/SiO2 thin films on polycarbonate.

    PubMed

    Fateh, Razan; Dillert, Ralf; Bahnemann, Detlef

    2013-03-19

    Transparent hydrophilic photocatalytic TiO2 coatings have been widely applied to endow the surfaces self-cleaning properties. A mixed metal oxide (TiO2/SiO2) can enhance the photocatalytic performance improving the ability of surface adsorption and increasing the amount of hydroxyl surface groups. The present work introduces a systematic study concerning the effect of the SiO2 addition to TiO2 films on the wettability, the photocatalytic activity, the adhesion strength, and the mechanical stability of the films. Transparent hydrophilic photocatalytic TiO2/SiO2 thin films were used to coat the polycarbonate (PC) substrate which was precoated by an intermediate SiO2 layer. The TiO2/SiO2 thin film was prepared employing a bulk TiO2 powder (Sachtleben Hombikat UV 100) and different molar ratios of tetraethoxysilane in acidic ethanol. A dip-coating process was used to deposit the films onto the polycarbonate substrate. The films were characterized by UV/vis spectrophotometry, FTIR spectroscopy, ellipsometry, BET, AFM, XRD, and water contact angle measurements. The mechanical stability and the UV resistance were examined. The photocatalytic activity of the coated surface was calculated from the kinetic analysis of methylene blue photodegradation measurements and compared with the photocatalytic activity of Pilkington Activ sheet glass. The coated surfaces displayed considerable photocatalytic activity and superhydrophilicity after exposure to UV light. The addition of SiO2 results in an improvement of the photocatalytic activity of the TiO2 film reaching the highest value at molar ratio TiO2/SiO2 equal to 1:0.9. The prepared films exhibit a good stability against UV(A) irradiation. PMID:23363048

  6. Long-term variability of the water transparency (Secchi Depth) in the Sea of Azov

    NASA Astrophysics Data System (ADS)

    Sorokina, V. V.; Kulygin, V. V.

    2013-05-01

    The spatial, seasonal, and interannual variability of the water's transparency (Secchi depth) in the Sea of Azov is studied using the database of long term transparency measurements for the 1922-2009 period and relevant materials on the meteorological, hydrological, and hydrobiological parameters of the environment. We identified four main types of seasonal variability of the water's transparency depending on the local conditions. The mean values of the Secchi depth are calculated for the different periods, which are distinguished by the differences in the relative role of the water transparency factors associated both with the climatic variations and the human activities.

  7. Tunable color parallel tandem organic light emitting devices with carbon nanotube and metallic sheet interlayers

    NASA Astrophysics Data System (ADS)

    Oliva, Jorge; Papadimitratos, Alexios; Desirena, Haggeo; De la Rosa, Elder; Zakhidov, Anvar A.

    2015-11-01

    Parallel tandem organic light emitting devices (OLEDs) were fabricated with transparent multiwall carbon nanotube sheets (MWCNT) and thin metal films (Al, Ag) as interlayers. In parallel monolithic tandem architecture, the MWCNT (or metallic films) interlayers are an active electrode which injects similar charges into subunits. In the case of parallel tandems with common anode (C.A.) of this study, holes are injected into top and bottom subunits from the common interlayer electrode; whereas in the configuration of common cathode (C.C.), electrons are injected into the top and bottom subunits. Both subunits of the tandem can thus be monolithically connected functionally in an active structure in which each subunit can be electrically addressed separately. Our tandem OLEDs have a polymer as emitter in the bottom subunit and a small molecule emitter in the top subunit. We also compared the performance of the parallel tandem with that of in series and the additional advantages of the parallel architecture over the in-series were: tunable chromaticity, lower voltage operation, and higher brightness. Finally, we demonstrate that processing of the MWCNT sheets as a common anode in parallel tandems is an easy and low cost process, since their integration as electrodes in OLEDs is achieved by simple dry lamination process.

  8. Tunable color parallel tandem organic light emitting devices with carbon nanotube and metallic sheet interlayers

    SciTech Connect

    Oliva, Jorge; Desirena, Haggeo; De la Rosa, Elder; Papadimitratos, Alexios; Zakhidov, Anvar A.

    2015-11-21

    Parallel tandem organic light emitting devices (OLEDs) were fabricated with transparent multiwall carbon nanotube sheets (MWCNT) and thin metal films (Al, Ag) as interlayers. In parallel monolithic tandem architecture, the MWCNT (or metallic films) interlayers are an active electrode which injects similar charges into subunits. In the case of parallel tandems with common anode (C.A.) of this study, holes are injected into top and bottom subunits from the common interlayer electrode; whereas in the configuration of common cathode (C.C.), electrons are injected into the top and bottom subunits. Both subunits of the tandem can thus be monolithically connected functionally in an active structure in which each subunit can be electrically addressed separately. Our tandem OLEDs have a polymer as emitter in the bottom subunit and a small molecule emitter in the top subunit. We also compared the performance of the parallel tandem with that of in series and the additional advantages of the parallel architecture over the in-series were: tunable chromaticity, lower voltage operation, and higher brightness. Finally, we demonstrate that processing of the MWCNT sheets as a common anode in parallel tandems is an easy and low cost process, since their integration as electrodes in OLEDs is achieved by simple dry lamination process.

  9. Avian Fact Sheet

    SciTech Connect

    NWCC Wildlife Work Group

    2004-12-01

    OAK-B135 After conducting four national research meetings, producing a document guiding research: Metrics and Methods for Determining or Monitoring Potential Impacts on Birds at Existing and Proposed Wind Energy Sites, 1999, and another paper, Avian Collisions with Wind Turbines: A Summary of Existing Studies and Comparisons to Other Sources of Avian Collision Mortality in the United States, 2001, the subcommittee recognized a need to summarize in a short fact sheet what is known about avian-wind interaction and what questions remain. This fact sheet attempts to summarize in lay terms the result of extensive discussion about avian-wind interaction on land. This fact sheet does not address research conducted on offshore development. This fact sheet is not intended as a conclusion on the subject; rather, it is a summary as of Fall/Winter 2002.

  10. Cerebral Aneurysms Fact Sheet

    MedlinePlus

    ... Awards Enhancing Diversity Find People About NINDS Cerebral Aneurysms Fact Sheet See a list of all NINDS ... I get more information? What is a cerebral aneurysm? A cerebral aneurysm (also known as an intracranial ...

  11. Sheet electron beam tester

    NASA Astrophysics Data System (ADS)

    Spear, Alexander Grenbeaux

    The DARPA HiFIVE project uses a pulsed electron sheet beam gun to power a traveling wave tube amplifier operating at 220 GHz. Presented is a method for characterizing the high current density 0.1 mm by 1 mm sheet electron beam. A tungsten tipped probe was scanned through the cross section of the sheet electron beam inside of a vacuum vessel. The probe was controlled with sub-micron precision using stepper motors and LabView computer control while boxcar averaging hardware sampled the pulsed beam. Matlab algorithms were used to interpret the data, calculate beam dimensions and current density, and create 2-dimensional cross section images. Full characterization of two separate HiFIVE sheet electron guns was accomplished and is also presented.

  12. Global ice sheet modeling

    SciTech Connect

    Hughes, T.J.; Fastook, J.L.

    1994-05-01

    The University of Maine conducted this study for Pacific Northwest Laboratory (PNL) as part of a global climate modeling task for site characterization of the potential nuclear waste respository site at Yucca Mountain, NV. The purpose of the study was to develop a global ice sheet dynamics model that will forecast the three-dimensional configuration of global ice sheets for specific climate change scenarios. The objective of the third (final) year of the work was to produce ice sheet data for glaciation scenarios covering the next 100,000 years. This was accomplished using both the map-plane and flowband solutions of our time-dependent, finite-element gridpoint model. The theory and equations used to develop the ice sheet models are presented. Three future scenarios were simulated by the model and results are discussed.

  13. Improving EM&V for Energy Efficiency Programs (Fact Sheet)

    SciTech Connect

    Not Available

    2012-07-01

    This fact sheet describes the objectives of the U.S. Department of Energy Uniform Methods Project to bring consistency to energy savings calculations in U.S. energy efficiency programs. The U.S. Department of Energy (DOE) is developing a framework and a set of protocols for determining gross energy savings from energy efficiency measures and programs. The protocols represent a refinement of the body of knowledge supporting energy efficiency evaluation, measurement, and verification (EM&V) activities. They have been written by technical experts within the field and reviewed by industry experts. Current EM&V practice allows for multiple methods for calculating energy savings. These methods were developed to meet the needs of energy efficiency program administrators and regulators. Although they served their original objectives well, they have resulted in inconsistent and incomparable savings results - even for identical measures. The goal of the Uniform Methods Project is to strengthen the credibility of energy savings determinations by improving EM&V, increasing the consistency and transparency of how energy savings are determined.

  14. Highly Stable Transparent Electrodes Made from Copper Nanotrough Coated with AZO/Al2O3.

    PubMed

    Li, Peng; Yan, Xingzhen; Ma, Jiangang; Xu, Haiyang; Liu, Yichun

    2016-04-01

    Due to their high flexibility, high conductivity and high transparency in a wide spectrum range, metal nanowires and meshes are considered to be two of the most promising candidates to replace the traditional transparent conducting films, such as tin doped indium oxide. In this paper, transparent conducting films made from copper nanotroughs are prepared by the electrospinning of polymer fibers and subsequent thermal evaporation of copper. The advantages of the technique include low junction resistance, low cost and low preparation temperature. Although the copper nanotrough transparent conducting films exhibited a low sheet resistance (19.2 Ω/sq), with a high transmittance (88% at 550 nm), the instability of copper in harsh environments seriously hinders its applications. In order to improve the stability of the metal transparent conducting films, copper nanotroughs were coated with 39 nm thick aluminum-doped zinc oxide and 1 nm thick aluminum oxide films by atomic layer deposition. The optical and electrical measurements show that coating copper nanotrough with oxides barely reduces the transparency of the films. It is worth noting that conductive oxide coating can effectively protect copper nanotroughs from thermal oxidation or acidic corrosion, whilst maintaining the same flexibility as copper nanotroughs on its own. PMID:27451715

  15. Highly conductive transparent organic electrodes with multilayer structures for rigid and flexible optoelectronics.

    PubMed

    Guo, Xiaoyang; Liu, Xingyuan; Lin, Fengyuan; Li, Hailing; Fan, Yi; Zhang, Nan

    2015-01-01

    Transparent electrodes are essential components for optoelectronic devices, such as touch panels, organic light-emitting diodes, and solar cells. Indium tin oxide (ITO) is widely used as transparent electrode in optoelectronic devices. ITO has high transparency and low resistance but contains expensive rare elements, and ITO-based devices have poor mechanical flexibility. Therefore, alternative transparent electrodes with excellent opto-electrical performance and mechanical flexibility will be greatly demanded. Here, organics are introduced into dielectric-metal-dielectric structures to construct the transparent electrodes on rigid and flexible substrates. We show that organic-metal-organic (OMO) electrodes have excellent opto-electrical properties (sheet resistance of below 10 Ω sq(-1) at 85% transmission), mechanical flexibility, thermal and environmental stabilities. The OMO-based polymer photovoltaic cells show performance comparable to that of devices based on ITO electrodes. This OMO multilayer structure can therefore be used to produce transparent electrodes suitable for use in a wide range of optoelectronic devices. PMID:26014889

  16. Effect of Oxygen on the Structural/Electrical Properties of NIZO Films on Transparent Flexible Substrates.

    PubMed

    Lim, Byung-Wook; Lee, Young-Jun; Kim, Joo-Hyung; Jeong, Hyeon-Taek; Ha, Tae-Won; Kim, Eun-Mi; Heo, Gi-Seok; Kim, Young-Baek; Kim, Hyeon-Ju; Lee, Ho-Saeng

    2015-10-01

    Thin film transparent oxides have attracted considerable attention over the last few decades for transparent electronic applications, such as flat panel displays, solar cells, touch-pads, and mobile devices. Metallic doped InZnO (IZO) films have been suggested for the transparent layer exhibiting semiconducting or metallic properties because of its controllable mobility and excellent electrical properties, but they show a degradation of the electrical performance under bending conditions. This study assessed Ni doped IZO (NIZO) films as a flexible transparent electrode on different flexible transparent substrates for flexible electronic applications. Thin NIZO films were deposited on cellulose, PES and glass substrates using a sputtering system with a single NIZO target (In2O3 73.8/ZnO 15.7/NiO 10.5 mol.%) at room temperature. During deposition of the NIZO films, the total flow rate of the carrier gas was maintained using a regulating system. The effects of the oxygen content in the carrier gas on the structural, electrical and optical properties of the thin films deposited on flexible substrates was characterized. The results highlight the feasibility of the transparent NIZO oxide layer on flexible substrates as a flexible electrode with a relatively high sheet resistance, which is strongly related to the crystallographic structure and oxygen content during the film deposition process. PMID:26726363

  17. Highly transparent, low-haze, hybrid cellulose nanopaper as electrodes for flexible electronics.

    PubMed

    Xu, Xuezhu; Zhou, Jian; Jiang, Long; Lubineau, Gilles; Ng, Tienkhee; Ooi, Boon S; Liao, Hsien-Yu; Shen, Chao; Chen, Long; Zhu, J Y

    2016-06-16

    Paper is an excellent candidate to replace plastics as a substrate for flexible electronics due to its low cost, renewability and flexibility. Cellulose nanopaper (CNP), a new type of paper made of nanosized cellulose fibers, is a promising substrate material for transparent and flexible electrodes due to its potentially high transparency and high mechanical strength. Although CNP substrates can achieve high transparency, they are still characterized by high diffuse transmittance and small direct transmittance, resulting in high optical haze of the substrates. In this study, we proposed a simple methodology for large-scale production of high-transparency, low-haze CNP comprising both long cellulose nanofibrils (CNFs) and short cellulose nanocrystals (CNCs). By varying the CNC/CNF ratio in the hybrid CNP, we could tailor its total transmittance, direct transmittance and diffuse transmittance. By increasing the CNC content, the optical haze of the hybrid CNP could be decreased and its transparency could be increased. The direct transmittance and optical haze of the CNP were 75.1% and 10.0%, respectively, greatly improved from the values of previously reported CNP (31.1% and 62.0%, respectively). Transparent, flexible electrodes were fabricated by coating the hybrid CNP with silver nanowires (AgNWs). The electrodes showed a low sheet resistance (minimum 1.2 Ω sq(-1)) and a high total transmittance (maximum of 82.5%). The electrodes were used to make a light emitting diode (LED) assembly to demonstrate their potential use in flexible displays. PMID:27270356

  18. Highly Conductive Transparent Organic Electrodes with Multilayer Structures for Rigid and Flexible Optoelectronics

    PubMed Central

    Guo, Xiaoyang; Liu, Xingyuan; Lin, Fengyuan; Li, Hailing; Fan, Yi; Zhang, Nan

    2015-01-01

    Transparent electrodes are essential components for optoelectronic devices, such as touch panels, organic light-emitting diodes, and solar cells. Indium tin oxide (ITO) is widely used as transparent electrode in optoelectronic devices. ITO has high transparency and low resistance but contains expensive rare elements, and ITO-based devices have poor mechanical flexibility. Therefore, alternative transparent electrodes with excellent opto-electrical performance and mechanical flexibility will be greatly demanded. Here, organics are introduced into dielectric–metal–dielectric structures to construct the transparent electrodes on rigid and flexible substrates. We show that organic-metal-organic (OMO) electrodes have excellent opto-electrical properties (sheet resistance of below 10 Ω sq−1 at 85% transmission), mechanical flexibility, thermal and environmental stabilities. The OMO-based polymer photovoltaic cells show performance comparable to that of devices based on ITO electrodes. This OMO multilayer structure can therefore be used to produce transparent electrodes suitable for use in a wide range of optoelectronic devices. PMID:26014889

  19. A highly crystalline single Au wire network as a high temperature transparent heater.

    PubMed

    Rao, K D M; Kulkarni, Giridhar U

    2014-06-01

    A transparent conductor which can generate high temperatures finds important applications in optoelectronics. In this article, a wire network made of Au on quartz is shown to serve as an effective high temperature transparent heater. The heater has been fabricated by depositing Au onto a cracked sacrificial template. The highly interconnected Au wire network thus formed exhibited a transmittance of ∼87% in a wide spectral range with a sheet resistance of 5.4 Ω □(-1). By passing current through the network, it could be joule heated to ∼600 °C within a few seconds. The extraordinary thermal performance and stability owe much to the seamless junctions present in the wire network. Furthermore, the wire network gets self-annealed through joule heating as seen from its increased crystallinity. Interestingly, both transmittance and sheet resistance improved following annealing to 92% and 3.2 Ω □(-1), respectively. PMID:24756335

  20. Energy information sheets

    SciTech Connect

    1995-07-01

    The National Energy Information Center (NEIC), as part of its mission, provides energy information and referral assistance to Federal, State, and local governments, the academic community, business and industrial organizations, and the public. The Energy Information Sheets was developed to provide general information on various aspects of fuel production, prices, consumption, and capability. Additional information on related subject matter can be found in other Energy Information Administration (EIA) publications as referenced at the end of each sheet.

  1. Biodiesel Basics (Fact Sheet)

    SciTech Connect

    Not Available

    2014-06-01

    This fact sheet provides a brief introduction to biodiesel, including a discussion of biodiesel blends, which blends are best for which vehicles, where to buy biodiesel, how biodiesel compares to diesel fuel in terms of performance, how biodiesel performs in cold weather, whether biodiesel use will plug vehicle filters, how long-term biodiesel use may affect engines, biodiesel fuel standards, and whether biodiesel burns cleaner than diesel fuel. The fact sheet also dismisses the use of vegetable oil as a motor fuel.

  2. Current sheet model

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The model of a rectenna based on the current sheet equivalency of a large planar array is described. The model is mathematically characterized by expression for the fraction of the incident plane wave that is reflected from the sheet. The model is conceptually justified for normal incidence by comparing it to the waveguide model in which evanescent modes, present as beyond and cutoff, correspond to the near field components which become negligible at any significant distance from the antenna array.

  3. Frontier of transparent oxide semiconductors

    NASA Astrophysics Data System (ADS)

    Ohta, Hiromichi; Nomura, Kenji; Hiramatsu, Hidenori; Ueda, Kazushige; Kamiya, Toshio; Hirano, Masahiro; Hosono, Hideo

    2003-12-01

    Recent advancements of transparent oxide semiconductors (TOS) toward new frontiers of "oxide electronics" are reviewed based on our efforts, categorized as "novel functional materials", "heteroepitaxial growth techniques", and "device fabrications". Topics focused in this paper are: (1) highly conductive ITO thin film with atomically flat surface, (2) p-type TOS material ZnRh 2O 4, (3) deep-ultraviolet (DUV) transparent conductive oxide β-Ga 2O 3 thin film, (4) electrochromic oxyfuolide NbO 2F, (5) single-crystalline films of InGaO 3(ZnO) m grown by reactive solid-phase epitaxy, (6) p-type semiconductor LaCuOS/Se epitaxial films capable of emitting UV- and purple-light, (7) p-n homojunction based on bipolar CuInO 2, (8) transparent FET based on single-crystalline InGaO 3(ZnO) 5 films, and (9) UV-light emitting diode based on p-n heterojunction.

  4. Optically transparent/colorless polyimides

    NASA Technical Reports Server (NTRS)

    Stclair, A. K.; Stclair, T. L.; Slemp, W.; Ezzell, K. S.

    1985-01-01

    Several series of linear aromatic polyimide films have been synthesized and characterized with the objective of obtaining maximum optical transparency. Two approaches have been used as part of this structure-property relationship study. The first approach is to vary the molecular structure so as to separate chromophoric centers and reduce electronic interactions between polymer chains to lower the intensity of color in the resulting polymer films. A second and concurrent approach is to perform polymerizations with highly purified monomers. Glass transition temperatures of thermally cured polyimide films are obtained by thermomechanical analysis and thermal decomposition temperatures are determined by thermogravimetric analysis. Transmittance UV-visible spectra of the polyimide films are compared to that of a commercial polyimide film. Fully imidized films are tested for solubility in common organic solvents. The more transparent films prepared in this study are evaluated for use on second-surface mirror thermal control coating systems. Lightly colored to colorless films are characterized by UV-visible spectroscopy before and after exposure to 300 equivalent solar hours UV irradiation and varying doses of 1 MeV electron irradiation. The effects of monomer purity, casting solvent and cure atmosphere on polyimide film transparency are also investigated.

  5. Nanostructured organic light-emitting diodes with electronic doping, transparent carbon nanotube charge injectors, and quantum dots

    NASA Astrophysics Data System (ADS)

    Williams, Christopher D.

    Organic light-emitting diodes (OLEDs) and polymeric light-emitting diodes (PLEDs) are rapidly-emerging technologies which are being studied extensively in industrial, academic, and government laboratories for applications in displays and solid-state lighting. Their thin film structure (with total thickness of active layers less than a micron) and the inherent flexibility of the constituent materials give them promise in the flat panel display industry as well as open new areas of possible applications for flexible transparent displays and even textile displays. The materials also show high electroluminescence efficiency, and with proper device engineering these devices demonstrate efficiencies and lifetimes which surpass current methods of lighting such at incandescent bulbs, which average approximately 1% efficiency. Lastly, the materials offer easy processing through well studied and developed methods such as thermal evaporation, solution spin-casting and ink jet printing. Ink jet printing of polymeric layers in PLEDs offers many advantages when considering mass production of display and lighting panels, as it allows uniform films to be produced on large area substrates using a simple roll-to-roll method. In this dissertation, we discuss several new methods and procedures which we have developed and used to produce OLEDs and PLEDs. More specifically these are electronic doping of transport layers, fluorescent doping of emissive layers by semiconductor nanocrystals (NC) (also known as quantum dots (QD)), and electrode engineering, namely by the use of transparent carbon nanotube sheets as charge injectors. We expand on the existing field of molecular doping and introduce a doped device with a very thick hole transport layer. Such a device is more resistant to failure due to excessive current density. We also investigate the effects of the presence of dopant molecules in the emissive layer of a multilayer OLED. This portion of the work introduces the negative

  6. Novel Smart Windows Based on Transparent Phosphorescent OLEDs

    SciTech Connect

    Brian D'Andrade; Stephen Forest

    2006-09-15

    In this program, Universal Display Corporation (UDC) and Princeton University developed the use of white transparent phosphorescent organic light emitting devices (PHOLEDs{trademark}) to make low-cost ''transparent OLED (TOLED) smart windows'', that switch rapidly from being a highly efficient solid-state light source to being a transparent window. PHOLEDs are ideal for large area devices, and the UDC-Princeton team has demonstrated white PHOLEDs with efficiencies of >24 lm/W at a luminance of 1,000 cd/m{sup 2}. TOLEDs have transparencies >70% over the visible wavelengths of light, but their transparency drops to less than 5% for wavelengths shorter than 350 nm, so they can also be used as ultraviolet (UV) light filters. In addition to controlling the flow of UV radiation, TOLEDs coupled with an electromechanical or electrically activated reflecting shutter on a glass window can be employed to control the flow of heat from infrared (IR) radiation by varying the reflectance/transparency of the glass for wavelengths greater than 800nm. One particularly attractive shutter technology is reversible electrochromic mirrors (REM). Our goal was therefore to integrate two innovative concepts to meet the U.S. Department of Energy goals: high power efficiency TOLEDs, plus electrically controlled reflectors to produce a ''smart window''. Our efforts during this one year program have succeeded in producing a prototype smart window shown in the Fig. I, below. The four states of the smart window are pictured: reflective with lamp on, reflective with lamp off, transparent with lamp on, and transparent with lamp off. In the transparent states, the image is an outdoor setting viewed through the window. In the reflective states, the image is an indoor setting viewed via reflection off the window. We believe that the integration of our high efficiency white phosphorescent TOLED illumination source, with electrically activated shutters represents an innovative low-cost approach to

  7. Oxidation-resistant hybrid metal oxides/metal nanodots/silver nanowires for high performance flexible transparent heaters

    NASA Astrophysics Data System (ADS)

    Kim, A.-Young; Kim, Min Kyu; Hudaya, Chairul; Park, Ji Hun; Byun, Dongjin; Lim, Jong Choo; Lee, Joong Kee

    2016-02-01

    Despite its excellent optical, electrical, mechanical, and thermal performances, a silver nanowire (AgNW)-based transparent conducting heater (TCH) still demonstrates several drawbacks such as facile nanowire breakdown on application of a high DC voltage, easy oxidation when exposed to harsh environments, leading to increased surface resistivity, and high resistance among wire junctions causing nonhomogeneous temperature profiles. To overcome these issues, the AgNW was hybridized with other transparent heating materials made of fluorine-doped tin oxide (FTO) thin films and NiCr nanodots (FTO/NiCr/AgNW). The dispersed NiCr nanodots (~50 nm) and FTO thin films (~20 nm) electrically bridge the nanowire junctions leading to a decreased sheet resistance and uniform temperature profiles. The hybrid transparent heater shows excellent optical transmittance (>90%) and high saturation temperature (162 °C) at low applied DC voltage (6 V). Moreover, the FTO/NiCr/AgNW heater exhibits a stable sheet resistance in a hostile environment, hence highlighting the excellent oxidation-resistance of the heating materials. These results indicate that the proposed hybrid transparent heaters could be a promising approach to combat the inherent problems associated with AgNW-based transparent heaters for various functional applications.Despite its excellent optical, electrical, mechanical, and thermal performances, a silver nanowire (AgNW)-based transparent conducting heater (TCH) still demonstrates several drawbacks such as facile nanowire breakdown on application of a high DC voltage, easy oxidation when exposed to harsh environments, leading to increased surface resistivity, and high resistance among wire junctions causing nonhomogeneous temperature profiles. To overcome these issues, the AgNW was hybridized with other transparent heating materials made of fluorine-doped tin oxide (FTO) thin films and NiCr nanodots (FTO/NiCr/AgNW). The dispersed NiCr nanodots (~50 nm) and FTO thin films

  8. Some Aspects of the Implementation of the Principle of Transparency in Russian Universities: Research, Experience, Perspectives

    ERIC Educational Resources Information Center

    Egorov, Evgeny Evgenievich; Lebedev?, Tatiana Evgenievna; Bulganina, Svetlana Viktorovna; Vasilyeva, Lyudmila Ivanovna

    2015-01-01

    The aim of this study is to identify achieved successes, existing gaps and possible prospects of implementing the principle of transparency by Russian universities. It was focused upon the information transparency of educational activities from the perspective of legal requirements and interests of applicants and university students. The analysis…

  9. Transparency.

    PubMed

    Keating, Michelle K

    2015-12-01

    This poem focuses on a patient who was suffering but whose physicians were optimistic for recovery. The author-physician saw the degree of suffering and made the patient's DNR, ending the suffering. The author expresses the need for complete honesty. (PsycINFO Database Record PMID:26641871

  10. Solution-processed transparent blue organic light-emitting diodes with graphene as the top cathode

    PubMed Central

    Chang, Jung-Hung; Lin, Wei-Hsiang; Wang, Po-Chuan; Taur, Jieh-I; Ku, Ting-An; Chen, Wei-Ting; Yan, Shiang-Jiuan; Wu, Chih-I

    2015-01-01

    Graphene thin films have great potential to function as transparent electrodes in organic electronic devices, due to their excellent conductivity and high transparency. Recently, organic light-emitting diodes (OLEDs)have been successfully demonstrated to possess high luminous efficiencies with p-doped graphene anodes. However, reliable methods to fabricate n-doped graphene cathodes have been lacking, which would limit the application of graphene in flexible electronics. In this paper, we demonstrate fully solution-processed OLEDs with n-type doped multilayer graphene as the top electrode. The work function and sheet resistance of graphene are modified by an aqueous process which can also transfer graphene on organic devices as the top electrodes. With n-doped graphene layers used as the top cathode, all-solution processed transparent OLEDs can be fabricated without any vacuum process. PMID:25892370

  11. Transparent actuator made with few layer graphene electrode and dielectric elastomer, for variable focus lens

    NASA Astrophysics Data System (ADS)

    Hwang, Taeseon; Kwon, Hyeok-Yong; Oh, Joon-Suk; Hong, Jung-Pyo; Hong, Seung-Chul; Lee, Youngkwan; Ryeol Choi, Hyouk; Jin Kim, Kwang; Hossain Bhuiya, Mainul; Nam, Jae-Do

    2013-07-01

    A transparent dielectric elastomer actuator driven by few-layer-graphene (FLG) electrode was experimentally investigated. The electrodes were made of graphene, which was dispersed in N-methyl-pyrrolidone. The transparent actuator was fabricated from developed FLG electrodes. The FLG electrode with its sheet resistance of 0.45 kΩ/sq (80 nm thick) was implemented to mask silicone elastomer. The developed FLG-driven actuator exhibited an optical transparency of over 57% at a wavenumber of 600 nm and produced bending displacement performance ranging from 29 to 946 μm as functions of frequency and voltage. The focus variation was clearly demonstrated under actuation to study its application-feasibility in variable focus lens and various opto-electro-mechanical devices.

  12. Volunteering among High School Students. Fact Sheet

    ERIC Educational Resources Information Center

    Marcelo, Karlo Barrios

    2007-01-01

    This fact sheet explores volunteering among high school students, ages 16-18. Overall, volunteering among high school students was down slightly in 2006 as compared to 2005. Additional information includes types of volunteer organizations and activities, and ways that high school students become involved in these activities. Volunteer rate vary by…

  13. Fully transparent quantum dot light-emitting diode integrated with graphene anode and cathode.

    PubMed

    Seo, Jung-Tak; Han, Junebeom; Lim, Taekyung; Lee, Ki-Heon; Hwang, Jungseek; Yang, Heesun; Ju, Sanghyun

    2014-12-23

    A fully transparent quantum dot light-emitting diode (QD-LED) was fabricated by incorporating two types (anode and cathode) of graphene-based electrodes, which were controlled in their work functions and sheet resistances. Either gold nanoparticles or silver nanowires were inserted between layers of graphene to control the work function, whereas the sheet resistance was determined by the number of graphene layers. The inserted gold nanoparticles or silver nanowires in graphene films caused a charge transfer and changed the work function to 4.9 and 4.3 eV, respectively, from the original work function (4.5 eV) of pristine graphene. Moreover the sheet resistance values for the anode and cathode electrodes were improved from ∼63,000 to ∼110 Ω/sq and from ∼100,000 to ∼741 Ω/sq as the number of graphene layers increased from 1 to 12 and from 1 to 8, respectively. The main peak wavelength, luminance, current efficiency, and optical transmittance of the fully transparent QD-LED integrated with graphene anode and cathode were 535 nm, ∼358 cd/m2, ∼0.45 cd/A, and 70-80%, respectively. The findings of the study are expected to lay a foundation for the production of high-efficiency, fully transparent, and flexible displays using graphene-based electrodes. PMID:25426762

  14. Silver nanowire/polyaniline composite transparent electrode with improved surface properties

    SciTech Connect

    Kumar, A.B.V. Kiran; Jiang, Jianwei; Bae, Chang Wan; Seo, Dong Min; Piao, Longhai Kim, Sang-Ho

    2014-09-15

    Highlights: • AgNWs/PANI transparent electrode was prepared by layer-by-layer coating method. • The surface roughness of the electrode reached to 6.5 nm (root mean square). • The electrode had reasonable sheet resistance (25 Ω/□) and transmittance (83.5%). - Abstract: Silver nanowires (AgNWs) are as potential candidates to replace indium tin oxide (ITO) in transparent electrodes because of their preferred conducting and optical properties. However, their rough surface properties are not favorable for the fabrication of optoelectronic devices, such as displays and thin-film solar cells. In the present investigation, AgNWs/polyaniline composite transparent electrodes with better surface properties were successfully prepared. AgNWs were incorporated into polyaniline:polystyrene sulfonate (PANI:PSS) by layer-by-layer coating and mechanical pressing. PANI:PSS decreased the surface roughness of the AgNWs electrode by filling the gap of the random AgNWs network. The transparent composite electrode had decreased surface roughness (root mean square 6.5 nm) with reasonable sheet resistance (25 Ω/□) and transmittance (83.5%)

  15. Visibly transparent organic photovoltaic with improved transparency and absorption based on tandem photonic crystal for greenhouse application.

    PubMed

    Yang, Fan; Zhang, Ye; Hao, Yuying; Cui, Yanxia; Wang, Wenyan; Ji, Ting; Shi, Fang; Wei, Bin

    2015-12-01

    We demonstrate a visible transparent organic photovoltaic (OPV) with improved transmission and absorption based on tandem photonic crystals (TPCs) for greenhouse applications. The proposed device has an average transmittance of 40.3% in the visible range of 400-700 nm and a high quality transparency spectrum for plant growth with a crop growth factor of 41.9%, considering the weight of the AM 1.5G solar spectrum. Compared with the corresponding transparent OPV without photonic crystals, an enhancement of 20.7% in the average transmittance and of 24.5% in the crop growth factor are achieved. Detailed investigations reveal that the improved transmittance is attributed to the excitation of the optical Tamm state and the light interference effect in TPC. Concomitantly, the total absorption efficiency in the active layer of the designed TPC based transparent OPV reaches 51.5%, being 1.78% higher than that of the transparent OPV without PC and 76% of that of the opaque counterpart. The improved absorption originates from the Bragg forbidden reflectance of TPC. Overall, our proposal achieves the optimized utilization of sunlight by light manipulation of TPC. PMID:26836682

  16. Copercolating Networks: An Approach for Realizing High-Performance Transparent Conductors using Multicomponent Nanostructured Networks

    NASA Astrophysics Data System (ADS)

    Das, Suprem R.; Sadeque, Sajia; Jeong, Changwook; Chen, Ruiyi; Alam, Muhammad A.; Janes, David B.

    2016-06-01

    Although transparent conductive oxides such as indium tin oxide (ITO) are widely employed as transparent conducting electrodes (TCEs) for applications such as touch screens and displays, new nanostructured TCEs are of interest for future applications, including emerging transparent and flexible electronics. A number of twodimensional networks of nanostructured elements have been reported, including metallic nanowire networks consisting of silver nanowires, metallic carbon nanotubes (m-CNTs), copper nanowires or gold nanowires, and metallic mesh structures. In these single-component systems, it has generally been difficult to achieve sheet resistances that are comparable to ITO at a given broadband optical transparency. A relatively new third category of TCEs consisting of networks of 1D-1D and 1D-2D nanocomposites (such as silver nanowires and CNTs, silver nanowires and polycrystalline graphene, silver nanowires and reduced graphene oxide) have demonstrated TCE performance comparable to, or better than, ITO. In such hybrid networks, copercolation between the two components can lead to relatively low sheet resistances at nanowire densities corresponding to high optical transmittance. This review provides an overview of reported hybrid networks, including a comparison of the performance regimes achievable with those of ITO and single-component nanostructured networks. The performance is compared to that expected from bulk thin films and analyzed in terms of the copercolation model. In addition, performance characteristics relevant for flexible and transparent applications are discussed. The new TCEs are promising, but significant work must be done to ensure earth abundance, stability, and reliability so that they can eventually replace traditional ITO-based transparent conductors.

  17. Red facts: Ethylene. Fact sheet

    SciTech Connect

    Not Available

    1992-09-01

    EPA is directed by the Federal Insecticide, Fungicide, and Rodenticide Act as amended in 1988 (FIFRA '88) to review all pesticide products containing active ingredients initially registered before November 1, 1984, and to reregister those products that have a substantially complete data base and do not pose unreasonable adverse effects to people or the environment. The pesticide reregistration program is to be completed by the late 1990's. The RED FACTS fact sheet summarizes EPA's conclusion, as set forth in the Reregistration Eligibility Document (or RED), that products containing a pesticide do not pose unreasonable risks when used as directed by Agency-approved labeling, and are eligible for reregistration.

  18. Fully transparent and rollable electronics.

    PubMed

    Mativenga, Mallory; Geng, Di; Kim, Byungsoon; Jang, Jin

    2015-01-28

    Major obstacles toward the manufacture of transparent and flexible display screens include the difficulty of finding transparent and flexible semiconductors and electrodes, temperature restrictions of flexible plastic substrates, and bulging or warping of the flexible electronics during processing. Here we report the fabrication and performance of fully transparent and rollable thin-film transistor (TFT) circuits for display applications. The TFTs employ an amorphous indium-gallium-zinc oxide semiconductor (with optical band gap of 3.1 eV) and amorphous indium-zinc oxide transparent conductive electrodes, and are built on 15-μm-thick solution-processed colorless polyimide (CPI), resulting in optical transmittance >70% in the visible range. As the CPI supports processing temperatures >300 °C, TFT performance on plastic is similar to that on glass, with typical field-effect mobility, turn-on voltage, and subthreshold voltage swing of 12.7 ± 0.5 cm(2)/V·s, -1.7 ± 0.2 V, and 160 ± 29 mV/dec, respectively. There is no significant degradation after rolling the TFTs 100 times on a cylinder with a radius of 4 mm or when shift registers, each consisting of 40 TFTs, are operated while bent to a radius of 2 mm. For handling purposes, carrier glass is used during fabrication, together with a very thin (∼1 nm) solution-processed carbon nanotube (CNT)/graphene oxide (GO) backbone that is first spin-coated on the glass to decrease adhesion of the CPI to the glass; peel strength of the CPI from glass decreases from 0.43 to 0.10 N/cm, which eases the process of detachment performed after device fabrication. Given that the CNT/GO remains embedded under the CPI after detachment, it minimizes wrinkling and decreases the substrate's tensile elongation from 8.0% to 4.6%. Device performance is also stable under electrostatic discharge exposures up to 10 kV, as electrostatic charge can be released via the conducting CNTs. PMID:25526282

  19. Conductivity in transparent oxide semiconductors

    NASA Astrophysics Data System (ADS)

    King, P. D. C.; Veal, T. D.

    2011-08-01

    Despite an extensive research effort for over 60 years, an understanding of the origins of conductivity in wide band gap transparent conducting oxide (TCO) semiconductors remains elusive. While TCOs have already found widespread use in device applications requiring a transparent contact, there are currently enormous efforts to (i) increase the conductivity of existing materials, (ii) identify suitable alternatives, and (iii) attempt to gain semiconductor-engineering levels of control over their carrier density, essential for the incorporation of TCOs into a new generation of multifunctional transparent electronic devices. These efforts, however, are dependent on a microscopic identification of the defects and impurities leading to the high unintentional carrier densities present in these materials. Here, we review recent developments towards such an understanding. While oxygen vacancies are commonly assumed to be the source of the conductivity, there is increasing evidence that this is not a sufficient mechanism to explain the total measured carrier concentrations. In fact, many studies suggest that oxygen vacancies are deep, rather than shallow, donors, and their abundance in as-grown material is also debated. We discuss other potential contributions to the conductivity in TCOs, including other native defects, their complexes, and in particular hydrogen impurities. Convincing theoretical and experimental evidence is presented for the donor nature of hydrogen across a range of TCO materials, and while its stability and the role of interstitial versus substitutional species are still somewhat open questions, it is one of the leading contenders for yielding unintentional conductivity in TCOs. We also review recent work indicating that the surfaces of TCOs can support very high carrier densities, opposite to the case for conventional semiconductors. In thin-film materials/devices and, in particular, nanostructures, the surface can have a large impact on the total

  20. Price transparency for medical devices.

    PubMed

    Pauly, Mark V; Burns, Lawton R

    2008-01-01

    Hospital buyers of medical devices contract with manufacturers with market power that sell differentiated products. The medical staff strongly influences hospitals' choice of devices. Sellers have sought to limit disclosure of transaction prices. Policy-makers have proposed legislation mandating disclosure, in the interest of greater transparency. We discuss why a manufacturer might charge different prices to different hospitals, the role that secrecy plays, and the consequences of secrecy versus disclosure. We argue that hospital-physician relationships are key to understanding what manufacturers gain from price discrimination. Price disclosure can catalyze a restructuring of those relationships, which, in turn, can improve hospital bargaining. PMID:18997210

  1. Manufacturing Laboratory (Fact Sheet)

    SciTech Connect

    Not Available

    2011-10-01

    This fact sheet describes the purpose, lab specifications, applications scenarios, and information on how to partner with NREL's Manufacturing Laboratory at the Energy Systems Integration Facility. The Manufacturing Laboratory at NREL's Energy Systems Integration Facility (ESIF) focuses on developing methods and technologies that will assist manufacturers of hydrogen and fuel cell technologies, as well as other renewable energy technologies, to scale up their manufacturing capabilities to volumes that meet DOE and industry targets. Specifically, the manufacturing activity is currently focused on developing and validating quality control techniques to assist manufacturers of low temperature and high temperature fuel cells in the transition from low to high volume production methods for cells and stacks. Capabilities include initial proof-of-concept studies through prototype system development and in-line validation. Existing diagnostic capabilities address a wide range of materials, including polymer films, carbon and catalyst coatings, carbon fiber papers and wovens, and multi-layer assemblies of these materials, as well as ceramic-based materials in pre- or post-fired forms. Work leading to the development of non-contact, non-destructive techniques to measure critical dimensional and functional properties of fuel cell and other materials, and validation of those techniques on the continuous processing line. This work will be supported by materials provided by our partners. Looking forward, the equipment in the laboratory is set up to be modified and extended to provide processing capabilities such as coating, casting, and deposition of functional layers, as well as associated processes such as drying or curing. In addition, continuous processes are used for components of organic and thin film photovoltaics (PV) as well as battery technologies, so synergies with these important areas will be explored.

  2. Improvements in purification of silver nanowires by decantation and fabrication of flexible transparent electrodes. Application to capacitive touch sensors.

    PubMed

    Mayousse, Céline; Celle, Caroline; Moreau, Eléonore; Mainguet, Jean-François; Carella, Alexandre; Simonato, Jean-Pierre

    2013-05-31

    Transparent flexible electrodes made of metallic nanowires, and in particular silver nanowires (AgNWs), appear as an extremely promising alternative to transparent conductive oxides for future optoelectronic devices. Though significant progresses have been made the last few years, there is still some room for improvement regarding the synthesis of high quality silver nanowire solutions and fabrication process of high performance electrodes. We show that the commonly used purification process can be greatly simplified through decantation. Using this process it is possible to fabricate flexible electrodes by spray coating with sheet resistance lower than 25 Ω sq⁻¹ at 90% transparency in the visible spectrum. These electrodes were used to fabricate an operative transparent flexible touch screen. To our knowledge this is the first reported AgNW based touch sensor relying on capacitive technology. PMID:23619480

  3. Orthographic transparency modulates the functional asymmetry in the fusiform cortex: An artificial language training study

    PubMed Central

    MEI, Leilei; XUE, Gui; LU, Zhong-Lin; HE, Qinghua; ZHANG, Mingxia; XUE, Feng; CHEN, Chuansheng; DONG, Qi

    2012-01-01

    The laterality difference in the occipitotemporal region between Chinese (bilaterality) and alphabetic languages (left laterality) has been attributed to their difference in visual appearance. However, these languages also differ in orthographic transparency. To disentangle the effect of orthographic transparency from visual appearance, we trained subjects to read the same artificial script either as an alphabetic (i.e., transparent orthography) or a logographic (i.e., nontransparent orthography) language. Consistent with our previous results, both types of phonological training enhanced activations in the left fusiform gyrus. More interestingly, the laterality in the fusiform gyrus (especially the posterior region) was modulated by the orthographic transparency of the artificial script (more left-lateralized activation after alphabetic training than after logographic training). These results provide an alternative account (i.e., orthographic transparency) for the laterality difference between Chinese and alphabetic languages, and may have important implications for the role of the fusiform in reading. PMID:22434043

  4. Formation of transferable transparent pristine graphene films at water/heptane interface

    NASA Astrophysics Data System (ADS)

    Oyer, A. J.; Carrillo, J.-M. Y.; Woltornist, S. J.; Adamson, D. H.; Dobrynin, A. V.

    2013-03-01

    We present a method of forming one to four layer thick pristine graphene films on glass substrates. These transparent and electrically conductive films are formed from natural graphite without the use of chemical treatment. The films are initially formed at a water/heptane interface and then transferred to a glass slide. Computer simulations of the graphene sheets at water/heptane interface show that the films are metastable, kinetically trapped assemblies. To evaluate stability of the film we used the Weighted Histogram Analysis Method to calculate the potential of the mean force and the height of the local potential barrier for single sheet and double sheet assembly of the graphene at water/heptane interface. The film structure on a glass slides was analyzed by Raman spectroscopy, optical microscopy, and transmission electron microscopy. These measurements show that the films are composed of overlapping graphene sheets one to four layers thick covering approximately 80% of the substrate. These low cost films are expected to find applications in the economical replacement of current inorganic transparent conductive films. This work was supported by the Air Force Office of Scientific Research award number FA9550-10-0462

  5. Criminal investigations and the Superfund program. Fact sheet (Final)

    SciTech Connect

    Not Available

    1990-09-01

    The fact sheet, directed toward any one who witnesses fraudulent activity in EPA programs, discusses areas in which fraud and abuse can occur and provides an understanding of the criminal investigation process that results from reports of suspicious activity.

  6. Slightly Conductive Transparent Films for Space Applications: Manufacturability and Durability

    NASA Technical Reports Server (NTRS)

    Uppala, N.; Griffin, J.; Vemulapalli, J.; Hambourger, P. D.

    2001-01-01

    Highly transparent, slightly conductive films of co-deposited indium tin oxide (ITO) and MgF, have possible applications for environmental protection of exterior surfaces of spacecraft. Reliable preparation of films with the desired sheet resistivity (approximately 10(exp 8) ohms/square) is difficult because the electrical properties of ITO-Mg F, are highly dependent on film composition. We have investigated the use of plasma emission monitoring to improve the reproducibility of films prepared by RF magnetron sputtering. While considerable improve ment was observed, it appears that some in-situ electrical or optica l characterization will be needed for reliable production coating wit h ITO-MgF,. We have also done further evaluation of a possibly undesi rable photoconductive effect previously observed in these films.

  7. Energy information sheets

    SciTech Connect

    Not Available

    1993-12-02

    The National Energy Information Center (NEIC), as part of its mission, provides energy information and referral assistance to Federal, State, and local governments, the academic community, business and industrial organizations, and the general public. Written for the general public, the EIA publication Energy Information Sheets was developed to provide information on various aspects of fuel production, prices, consumption and capability. The information contained herein pertains to energy data as of December 1991. Additional information on related subject matter can be found in other EIA publications as referenced at the end of each sheet.

  8. Transparent ferromagnetic and semiconducting behavior in Fe-Dy-Tb based amorphous oxide films

    PubMed Central

    Taz, H.; Sakthivel, T.; Yamoah, N. K.; Carr, C.; Kumar, D.; Seal, S.; Kalyanaraman, R.

    2016-01-01

    We report a class of amorphous thin film material comprising of transition (Fe) and Lanthanide metals (Dy and Tb) that show unique combination of functional properties. Films were deposited with different atomic weight ratio (R) of Fe to Lanthanide (Dy + Tb) using electron beam co-evaporation at room temperature. The films were found to be amorphous, with grazing incidence x-ray diffraction and x-ray photoelectron spectroscopy studies indicating that the films were largely oxidized with a majority of the metal being in higher oxidation states. Films with R = 0.6 were semiconducting with visible light transmission due to a direct optical band-gap (2.49 eV), had low resistivity and sheet resistance (7.15 × 10−4 Ω-cm and ~200 Ω/sq respectively), and showed room temperature ferromagnetism. A metal to semiconductor transition with composition (for R < 11.9) also correlated well with the absence of any metallic Fe0 oxidation state in the R = 0.6 case as well as a significantly higher fraction of oxidized Dy. The combination of amorphous microstructure and room temperature electronic and magnetic properties could lead to the use of the material in multiple applications, including as a transparent conductor, active material in thin film transistors for display devices, and in spin-dependent electronics. PMID:27298196

  9. Transparent ferromagnetic and semiconducting behavior in Fe-Dy-Tb based amorphous oxide films

    NASA Astrophysics Data System (ADS)

    Taz, H.; Sakthivel, T.; Yamoah, N. K.; Carr, C.; Kumar, D.; Seal, S.; Kalyanaraman, R.

    2016-06-01

    We report a class of amorphous thin film material comprising of transition (Fe) and Lanthanide metals (Dy and Tb) that show unique combination of functional properties. Films were deposited with different atomic weight ratio (R) of Fe to Lanthanide (Dy + Tb) using electron beam co-evaporation at room temperature. The films were found to be amorphous, with grazing incidence x-ray diffraction and x-ray photoelectron spectroscopy studies indicating that the films were largely oxidized with a majority of the metal being in higher oxidation states. Films with R = 0.6 were semiconducting with visible light transmission due to a direct optical band-gap (2.49 eV), had low resistivity and sheet resistance (7.15 × 10‑4 Ω-cm and ~200 Ω/sq respectively), and showed room temperature ferromagnetism. A metal to semiconductor transition with composition (for R < 11.9) also correlated well with the absence of any metallic Fe0 oxidation state in the R = 0.6 case as well as a significantly higher fraction of oxidized Dy. The combination of amorphous microstructure and room temperature electronic and magnetic properties could lead to the use of the material in multiple applications, including as a transparent conductor, active material in thin film transistors for display devices, and in spin-dependent electronics.

  10. Transparent ferromagnetic and semiconducting behavior in Fe-Dy-Tb based amorphous oxide films.

    PubMed

    Taz, H; Sakthivel, T; Yamoah, N K; Carr, C; Kumar, D; Seal, S; Kalyanaraman, R

    2016-01-01

    We report a class of amorphous thin film material comprising of transition (Fe) and Lanthanide metals (Dy and Tb) that show unique combination of functional properties. Films were deposited with different atomic weight ratio (R) of Fe to Lanthanide (Dy + Tb) using electron beam co-evaporation at room temperature. The films were found to be amorphous, with grazing incidence x-ray diffraction and x-ray photoelectron spectroscopy studies indicating that the films were largely oxidized with a majority of the metal being in higher oxidation states. Films with R = 0.6 were semiconducting with visible light transmission due to a direct optical band-gap (2.49 eV), had low resistivity and sheet resistance (7.15 × 10(-4) Ω-cm and ~200 Ω/sq respectively), and showed room temperature ferromagnetism. A metal to semiconductor transition with composition (for R < 11.9) also correlated well with the absence of any metallic Fe(0) oxidation state in the R = 0.6 case as well as a significantly higher fraction of oxidized Dy. The combination of amorphous microstructure and room temperature electronic and magnetic properties could lead to the use of the material in multiple applications, including as a transparent conductor, active material in thin film transistors for display devices, and in spin-dependent electronics. PMID:27298196

  11. Enhanced transparent conducting networks on plastic substrates modified with highly oxidized graphene oxide nanosheets

    NASA Astrophysics Data System (ADS)

    Woo, Jong Seok; Sin, Dong Hun; Kim, Haena; Jang, Jeong In; Kim, Ho Young; Lee, Geon-Woong; Cho, Kilwon; Park, Soo-Young; Han, Joong Tark

    2016-03-01

    Atomically thin and two-dimensional graphene oxide (GO) is a very fascinating material because of its functional groups, high transparency, and solution processability. Here we show that highly oxidized GO (HOGO) nanosheets serve as an effective interfacial modifier of transparent conducting films with one-dimensional (1D) silver nanowires (AgNWs) and single-walled carbon nanotubes (SWCNTs). Optically transparent and small-sized GO nanosheets, with minimal sp2 domains, were successfully fabricated by step-wise oxidation and exfoliation of graphite. We demonstrated that under-coated HOGO further decreases the sheet resistance of the SWCNT film top-coated with HOGO by increasing the contact area between the SWCNTs and HOGO nanosheets by generating hole carriers in the SWCNT as a result of charge transfer. Moreover, HOGO nanosheets with AgNWs contribute to the efficient thermal joining of AgNW networks on plastic substrates by limiting the thermal embedding of AgNWs into the plastic surface, resulting in efficient decrease of the sheet resistance. Furthermore, flexible organic photovoltaic cells with GO-modified AgNW anodes on a flexible substrate were successfully demonstrated.Atomically thin and two-dimensional graphene oxide (GO) is a very fascinating material because of its functional groups, high transparency, and solution processability. Here we show that highly oxidized GO (HOGO) nanosheets serve as an effective interfacial modifier of transparent conducting films with one-dimensional (1D) silver nanowires (AgNWs) and single-walled carbon nanotubes (SWCNTs). Optically transparent and small-sized GO nanosheets, with minimal sp2 domains, were successfully fabricated by step-wise oxidation and exfoliation of graphite. We demonstrated that under-coated HOGO further decreases the sheet resistance of the SWCNT film top-coated with HOGO by increasing the contact area between the SWCNTs and HOGO nanosheets by generating hole carriers in the SWCNT as a result of charge

  12. An Ag-grid/graphene hybrid structure for large-scale, transparent, flexible heaters

    NASA Astrophysics Data System (ADS)

    Kang, Junmo; Jang, Yonghee; Kim, Youngsoo; Cho, Seung-Hyun; Suhr, Jonghwan; Hong, Byung Hee; Choi, Jae-Boong; Byun, Doyoung

    2015-04-01

    Recently, carbon materials such as carbon nanotubes and graphene have been proposed as alternatives to indium tin oxide (ITO) for fabricating transparent conducting materials. However, obtaining low sheet resistance and high transmittance of these carbon materials has been challenging due to the intrinsic properties of the materials. In this paper, we introduce highly transparent and flexible conductive films based on a hybrid structure of graphene and an Ag-grid. Electrohydrodynamic (EHD) jet printing was used to produce a micro-scale grid consisting of Ag lines less than 10 μm wide. We were able to directly write the Ag-grid on a large-area graphene/flexible substrate due to the high conductivity of graphene. The hybrid electrode could be fabricated using hot pressing transfer and EHD jet printing in a non-vacuum, maskless, and low-temperature environment. The hybrid electrode offers an effective and simple route for achieving a sheet resistance as low as ~4 Ω per square with ~78% optical transmittance. Finally, we demonstrate that transparent flexible heaters based on the hybrid conductive films could be used in a vehicle or a smart window system.Recently, carbon materials such as carbon nanotubes and graphene have been proposed as alternatives to indium tin oxide (ITO) for fabricating transparent conducting materials. However, obtaining low sheet resistance and high transmittance of these carbon materials has been challenging due to the intrinsic properties of the materials. In this paper, we introduce highly transparent and flexible conductive films based on a hybrid structure of graphene and an Ag-grid. Electrohydrodynamic (EHD) jet printing was used to produce a micro-scale grid consisting of Ag lines less than 10 μm wide. We were able to directly write the Ag-grid on a large-area graphene/flexible substrate due to the high conductivity of graphene. The hybrid electrode could be fabricated using hot pressing transfer and EHD jet printing in a non

  13. Colorless and transparent copolyimide nanocomposites.

    PubMed

    Bae, Hye-Jin; Kim, Yong Seok; Chang, Jin-Hae

    2014-12-01

    Copolyimides (Co-PIs) were synthesized from 2,2'-bis(trifluoromethyl) benzidine (TFB) and different ratios of 4,4'-(hexafluoroisopropylidene) diphthalic anhydride (6FDA) and pyromellitic dianhydride (PMDA). The Co-PI films were obtained from poly(amic acid) (PAA) by solution-casting through typical chemical and thermal imidizations. The thermal properties and optical transparency of the Co-PI films with various PMDA monomer contents were investigated. It was found that with increasing PMDA content, the thermal transition temperatures of the Co-PI films increased. Co-PI nanocomposites were prepared with various amounts of organically modified hectorite (STN) on a TFB:6FDA:PMDA = 1.0:0.9:0.1 mole ratio Co-PI hybrid film to examine the thermal properties, morphology, and optical transparency. The thermo-optical properties of the Co-PI hybrid films deteriorated with increasing clay content. However, the coefficient of thermal expansion (CTE) and oxygen barrier properties of the PI hybrid films improved with increasing clay content. PMID:25971113

  14. Transparent communications permit unmanned operations

    SciTech Connect

    1995-07-01

    Not-normally-manned platforms are not a new development. However, their use in harsher environments has until recently, been limited. Development of reliable communications networks capable of handling the large amounts of data required for process control in real time with distributed control systems (DCSs) has been a key factor in making the concept viable for harsher, more remote environments. The article below examines the transparent communications network and DCS installed on Pickerill field, offshore UK, by Fisher-Rosemount Systems and its operational parameters. Pickerill field, some 50 mi off the Lincolnshire coast, comprises two small unmanned platforms producing gas under remote control from Arco`s operations base at Great Yarmouth about 60 mi south. Reliable communication is required both with the two platforms offshore and with Conoco`s gas processing operators at Theddlethorpe. Fundamental to project success was the ability of the process control system to provide entirely secure and transparent communication with equipment offshore and thus enable operators at Great Yarmouth to interact with the process as if it were local to their control center.

  15. Speed Judgements of Transparent Stimuli

    NASA Technical Reports Server (NTRS)

    Mulligan, Jeffrey B.; Null, Cynthia H. (Technical Monitor)

    1996-01-01

    When two moving patterns are combined additively, observers often perceive two transparent surfaces, even when there are no cues supporting this segmentation in a frozen snapshot. We examined the ability of observers to make quantitative judgments about the speed of one of the patterns under these conditions. The component patterns consisted of band-pass filtered random noise presented in a spatial Gaussian contrast envelope, presented for 250 ms. On each trial a standard pattern appeared on one side of the fixation point, while a test pattern appeared on the other. The test pattern moved in the same direction as the standard, but with a speed which varied from trial to trial using a staircase procedure. The subjects' task was to report the side of the fixation point on which faster motion was seen. In some conditions the test stimulus was made to appear transparent by adding a mask pattern. When the mask was stationary, or moved slowly with respect to the test, no significant biases were introduced and discrimination performance was comparable to the no-mask condition (typically 3%). If the mask moved over the test with similar speed, however, the task became much harder, regardless of whether the mask moved opposite or orthogonal to the test. (Some subjects commented on a perceived directional repulsion between tests and orthogonally moving masks.) These results suggest the use of non-directional temporal channels in the performance of the speed discrimination task.

  16. A pincer-shaped plasma sheet at Uranus

    SciTech Connect

    Hammond, C.M.; Walker, R.J.; Kivelson, M.G. )

    1990-09-01

    A model from Voigt et al. (1987) and an MHD simulation from Walker et al. (1989) both show that the curvature of the plasma sheet at Uranus changes as the dipole tilt varies between 38{degree} and 22{degree}. The models suggest that one of the two partial traversals of the uranian plasma sheet made during the outbound trajectory of Voyager 2 can be explained as an entry into the highly curved plasma sheet that develops when Uranus is near the maximum dipole tilt value of 38{degree}; previously both partial traversals have been explained as anomalous. The spacecraft would have reversed its motion relative to the plasma sheet as the continued rotation diminished the dipole tilt and the retreating plasma sheet uncurled. As the dipole tilt approached its minimum value, spacecraft motion towards the neutral sheet resumed and the traversal of the plasma sheet was completed. Evidence from the PWS plasma wave detector suggests that the spacecraft trajectory skimmed the plasma sheet boundary layer for several hours prior to the partial immersion. The plasma sheet of the Voigt et al. model was not located near the spacecraft during this time interval. On the other hand, the MHD simulation reveals a plasma sheet that is more curved than in the Boigt et al. model; near maximum dipole tilt, the plasma sheet is pincer-shaped. The unusual geometry implies that Voyager 2 remained near the plasma sheet boundary layer during the period suggested by the PWS data. Thus the simulation accounts easily for the first of the plasma sheet encounters previously called anomalous. The second partial immersion remains anomalous, having previously been related to substorm activity, and thus is not discussed here. The stagnation distances of the earth and Uranus at the nose of the magnetopause were used to scale the Walker et al. (1989) simulation of the terrestrial magnetosphere to represent the uranian magnetosphere.

  17. 5. Historic American Buildings Survey Taken from drawing sheet, SHEET ...

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

    5. Historic American Buildings Survey Taken from drawing sheet, SHEET #21, Showing the house as restored since Survey. (Dormer windows omitted as not authentic) - Samuel des Marest House, River Road, New Milford, Bergen County, NJ

  18. 71. PALMDALE WATER COMPANY, EASTWOOD MULTIPLEARCHED DAM: STRESS SHEET, SHEET ...

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

    71. PALMDALE WATER COMPANY, EASTWOOD MULTIPLE-ARCHED DAM: STRESS SHEET, SHEET 3; DECEMBER 20, 1918. Littlerock Water District files. - Little Rock Creek Dam, Little Rock Creek, Littlerock, Los Angeles County, CA

  19. Transparent displays enabled by resonant nanoparticle scattering

    NASA Astrophysics Data System (ADS)

    Hsu, Chia Wei; Zhen, Bo; Qiu, Wenjun; Shapira, Ofer; Delacy, Brendan G.; Joannopoulos, John D.; Soljačić, Marin

    2014-01-01

    The ability to display graphics and texts on a transparent screen can enable many useful applications. Here we create a transparent display by projecting monochromatic images onto a transparent medium embedded with nanoparticles that selectively scatter light at the projected wavelength. We describe the optimal design of such nanoparticles, and experimentally demonstrate this concept with a blue-color transparent display made of silver nanoparticles in a polymer matrix. This approach has attractive features including simplicity, wide viewing angle, scalability to large sizes and low cost.

  20. Transparent capacitors with hybrid ZnO:Al and Ag nanowires as electrodes.

    PubMed

    Zhang, Guozhen; Wu, Hao; Wang, Xiao; Wang, Ti; Liu, Chang

    2016-03-11

    Transparent conducting films with a composite structure of AlZnO-Ag nanowires (AgNWs) have been prepared by atomic layer deposition. The sheet resistance was reduced from 120 to 9 Ω when the AgNW networks were involved. Transparent capacitors with Al2O3-TiO2-Al2O3 dielectrics were fabricated on the composite electrodes and demonstrated a capacitance density of 10.1 fF μm(-2), which was significantly higher than that of capacitors with AlZnO electrodes (8.8 fF μm(-1)). The capacitance density remained almost unchanged in a broad frequency range from 3 kHz to 1 MHz. Moreover, a low leakage current density of 2.4 × 10(-7) A cm(-2) at 1 V was achieved. Transparent and flexible capacitors were also fabricated using the composite electrodes, and demonstrated an improved bendability. The transparent capacitors showed an average optical transmittance over 70% in the visible range, and thus open the door to practical applications in transparent integrated circuits. PMID:26866788

  1. Polymer-metal hybrid transparent electrodes for flexible electronics

    PubMed Central

    Kang, Hongkyu; Jung, Suhyun; Jeong, Soyeong; Kim, Geunjin; Lee, Kwanghee

    2015-01-01

    Despite nearly two decades of research, the absence of ideal flexible and transparent electrodes has been the largest obstacle in realizing flexible and printable electronics for future technologies. Here we report the fabrication of ‘polymer-metal hybrid electrodes’ with high-performance properties, including a bending radius <1 mm, a visible-range transmittance>95% and a sheet resistance <10 Ω sq−1. These features arise from a surface modification of the plastic substrates using an amine-containing nonconjugated polyelectrolyte, which provides ideal metal-nucleation sites with a surface-density on the atomic scale, in combination with the successive deposition of a facile anti-reflective coating using a conducting polymer. The hybrid electrodes are fully functional as universal electrodes for high-end flexible electronic applications, such as polymer solar cells that exhibit a high power conversion efficiency of 10% and polymer light-emitting diodes that can outperform those based on transparent conducting oxides. PMID:25790133

  2. Flexible and transparent metallic grid electrodes prepared by evaporative assembly.

    PubMed

    Park, Jae Hoon; Lee, Dong Yun; Kim, Young-Hoon; Kim, Jung Kyu; Lee, Jung Heon; Park, Jong Hyeok; Lee, Tae-Woo; Cho, Jeong Ho

    2014-08-13

    We propose a novel approach to fabricating flexible transparent metallic grid electrodes via evaporative deposition involving flow-coating. A transparent flexible metal grid electrode was fabricated through four essential steps including: (i) polymer line pattern formation on the thermally evaporated metal layer onto a plastic substrate; (ii) rotation of the stage by 90° and the formation of the second polymer line pattern; (iii) etching of the unprotected metal region; and (iv) removal of the residual polymer from the metal grid pattern. Both the metal grid width and the spacing were systematically controlled by varying the concentration of the polymer solution and the moving distance between intermittent stop times of the polymer blade. The optimized Au grid electrodes exhibited an optical transmittance of 92% at 550 nm and a sheet resistance of 97 Ω/sq. The resulting metallic grid electrodes were successfully applied to various organic electronic devices, such as organic field-effect transistors (OFETs), organic light-emitting diodes (OLEDs), and organic solar cells (OSCs). PMID:24999517

  3. Foldable Transparent Substrates with Embedded Electrodes for Flexible Electronics.

    PubMed

    Kim, Jin-Hoon; Park, Jin-Woo

    2015-08-26

    We present highly flexible transparent electrodes composed of silver nanowire (AgNW) networks and silica aerogels embedded into UV-curable adhesive photopolymers (APPs). Because the aerogels have an extremely high surface-to-volume ratio, the enhanced van der Waals forces of the aerogel surfaces result in more AgNWs being uniformly coated onto a release substrate and embedded into the APP when mixed with an AgNW solution at a fixed concentration. The uniform distribution of the embedded composite electrodes of AgNWs and aerogels was verified by the Joule heating test. The APP with the composite electrodes has a lower sheet resistance (Rs) and a better mechanical stability compared with APP without aerogels. The APP with the embedded electrodes is a freestanding flexible substrate and can be used as an electrode coating on a polymer substrate, such as polydimethylsiloxane and polyethylene terephthalate. On the basis of the bending test results, the APPs with composite electrodes were sufficiently flexible to withstand a 1 mm bending radius (rb) and could be foldable with a slight change in Rs. Organic light emitting diodes were successfully fabricated on the APP with the composite electrodes, indicating the strong potential of the proposed flexible TEs for application as highly flexible transparent conductive substrates. PMID:26258906

  4. Polymer-metal hybrid transparent electrodes for flexible electronics

    NASA Astrophysics Data System (ADS)

    Kang, Hongkyu; Jung, Suhyun; Jeong, Soyeong; Kim, Geunjin; Lee, Kwanghee

    2015-03-01

    Despite nearly two decades of research, the absence of ideal flexible and transparent electrodes has been the largest obstacle in realizing flexible and printable electronics for future technologies. Here we report the fabrication of ‘polymer-metal hybrid electrodes’ with high-performance properties, including a bending radius <1 mm, a visible-range transmittance>95% and a sheet resistance <10 Ω sq-1. These features arise from a surface modification of the plastic substrates using an amine-containing nonconjugated polyelectrolyte, which provides ideal metal-nucleation sites with a surface-density on the atomic scale, in combination with the successive deposition of a facile anti-reflective coating using a conducting polymer. The hybrid electrodes are fully functional as universal electrodes for high-end flexible electronic applications, such as polymer solar cells that exhibit a high power conversion efficiency of 10% and polymer light-emitting diodes that can outperform those based on transparent conducting oxides.

  5. Exposure age and ice-sheet model constraints on Pliocene East Antarctic ice sheet dynamics.

    PubMed

    Yamane, Masako; Yokoyama, Yusuke; Abe-Ouchi, Ayako; Obrochta, Stephen; Saito, Fuyuki; Moriwaki, Kiichi; Matsuzaki, Hiroyuki

    2015-01-01

    The Late Pliocene epoch is a potential analogue for future climate in a warming world. Here we reconstruct Plio-Pleistocene East Antarctic Ice Sheet (EAIS) variability using cosmogenic nuclide exposure ages and model simulations to better understand ice sheet behaviour under such warm conditions. New and previously published exposure ages indicate interior-thickening during the Pliocene. An ice sheet model with mid-Pliocene boundary conditions also results in interior thickening and suggests that both the Wilkes Subglacial and Aurora Basins largely melted, offsetting increased ice volume. Considering contributions from West Antarctica and Greenland, this is consistent with the most recent IPCC AR5 estimate, which indicates that the Pliocene sea level likely did not exceed +20 m on Milankovitch timescales. The inception of colder climate since ∼3 Myr has increased the sea ice cover and inhibited active moisture transport to Antarctica, resulting in reduced ice sheet thickness, at least in coastal areas. PMID:25908601

  6. Exposure age and ice-sheet model constraints on Pliocene East Antarctic ice sheet dynamics

    PubMed Central

    Yamane, Masako; Yokoyama, Yusuke; Abe-Ouchi, Ayako; Obrochta, Stephen; Saito, Fuyuki; Moriwaki, Kiichi; Matsuzaki, Hiroyuki

    2015-01-01

    The Late Pliocene epoch is a potential analogue for future climate in a warming world. Here we reconstruct Plio-Pleistocene East Antarctic Ice Sheet (EAIS) variability using cosmogenic nuclide exposure ages and model simulations to better understand ice sheet behaviour under such warm conditions. New and previously published exposure ages indicate interior-thickening during the Pliocene. An ice sheet model with mid-Pliocene boundary conditions also results in interior thickening and suggests that both the Wilkes Subglacial and Aurora Basins largely melted, offsetting increased ice volume. Considering contributions from West Antarctica and Greenland, this is consistent with the most recent IPCC AR5 estimate, which indicates that the Pliocene sea level likely did not exceed +20 m on Milankovitch timescales. The inception of colder climate since ∼3 Myr has increased the sea ice cover and inhibited active moisture transport to Antarctica, resulting in reduced ice sheet thickness, at least in coastal areas. PMID:25908601

  7. Exposure age and ice-sheet model constraints on Pliocene East Antarctic ice sheet dynamics

    NASA Astrophysics Data System (ADS)

    Yamane, Masako; Yokoyama, Yusuke; Abe-Ouchi, Ayako; Obrochta, Stephen; Saito, Fuyuki; Moriwaki, Kiichi; Matsuzaki, Hiroyuki

    2015-04-01

    The Late Pliocene epoch is a potential analogue for future climate in a warming world. Here we reconstruct Plio-Pleistocene East Antarctic Ice Sheet (EAIS) variability using cosmogenic nuclide exposure ages and model simulations to better understand ice sheet behaviour under such warm conditions. New and previously published exposure ages indicate interior-thickening during the Pliocene. An ice sheet model with mid-Pliocene boundary conditions also results in interior thickening and suggests that both the Wilkes Subglacial and Aurora Basins largely melted, offsetting increased ice volume. Considering contributions from West Antarctica and Greenland, this is consistent with the most recent IPCC AR5 estimate, which indicates that the Pliocene sea level likely did not exceed +20 m on Milankovitch timescales. The inception of colder climate since ~3 Myr has increased the sea ice cover and inhibited active moisture transport to Antarctica, resulting in reduced ice sheet thickness, at least in coastal areas.

  8. Quick Information Sheets. 1988.

    ERIC Educational Resources Information Center

    Wisconsin Univ., Madison. Trace Center.

    The Trace Center gathers and organizes information on communication, control, and computer access for handicapped individuals. The information is disseminated in the form of brief sheets describing print, nonprint, and organizational resources and listing addresses and telephone numbers for ordering or for additional information. This compilation…

  9. Quick Information Sheets.

    ERIC Educational Resources Information Center

    Wisconsin Univ., Madison. Trace Center.

    This compilation of "Trace Quick Sheets" provides descriptions, prices, and ordering information for products and services that assist with communication, control, and computer access for disabled individuals. Product descriptions or product sources are included for: adaptive toys and toy modifications; head pointers, light pointers, and…

  10. Insulation Fact Sheet.

    ERIC Educational Resources Information Center

    Conservation and Renewable Energy Inquiry and Referral Service (DOE), Silver Spring, MD.

    Heating and cooling account for 50-70% of the energy consumed in the average American home. Heating water accounts for another 20%. A poorly insulated home loses much of this energy, causing drafty rooms and high energy bills. This fact sheet discusses how to determine if your home needs more insulation, the additional thermal resistance (called…

  11. Ethanol Myths Fact Sheet

    SciTech Connect

    2009-10-27

    Ethanol is a clean, renewable fuel that is helping to reduce our nation’s dependence on oil and can offer additional economic and environmental benefits in the future. This fact sheet is intended to address some common misconceptions about this important alternative fuel.

  12. GED Testing Fact Sheet

    ERIC Educational Resources Information Center

    GED Testing Service, 2009

    2009-01-01

    This GED Testing fact sheet provides information on: (1) GED[R] Tests; (2) Versions and Editions of the GED Tests; (3) Earning a Credential; (4) GED Testing Service[R]; (5) History of the GED Tests; (6) Who Accepts the GED Credential; (7) Public/Private Partnership of GEDTS; (8) Renowned GED Credential Recipients; (9) GED Testing Numbers for 2008;…

  13. Algal Biofuels Fact Sheet

    SciTech Connect

    2009-10-27

    This fact sheet provides information on algal biofuels, which are generating considerable interest around the world. They may represent a sustainable pathway for helping to meet the U.S. biofuel production targets set by the Energy Independence and Security Act of 2007.

  14. Youth Demographics. Fact Sheet

    ERIC Educational Resources Information Center

    Lopez, Mark Hugo; Marcelo, Karlo Barrios

    2006-01-01

    This fact sheet compares the numbers of 18-25 year-old residents and citizens by gender, race, ethnicity, geographic distribution, marital status, military status, unemployment, educational attainment, and assesses population trends from 1968-2006. It explores such demographic characteristics of young people using data from the March Annual…

  15. Ethanol Basics (Fact Sheet)

    SciTech Connect

    Not Available

    2015-01-01

    Ethanol is a widely-used, domestically-produced renewable fuel made from corn and other plant materials. More than 96% of gasoline sold in the United States contains ethanol. Learn more about this alternative fuel in the Ethanol Basics Fact Sheet, produced by the U.S. Department of Energy's Clean Cities program.

  16. Reading Recovery. [Fact Sheets].

    ERIC Educational Resources Information Center

    Reading Recovery Council of North America, Columbus, OH.

    This set of 10 fact sheets (each 2 to 4 pages long) addresses aspects of Reading Recovery, a program that helps children to be proficient readers and writers by the end of the first grade. It discusses the basic facts of Reading Recovery; Reading Recovery for Spanish literacy; Reading Recovery lessons; Reading Recovery professional development;…

  17. Rubella - Fact Sheet for Parents

    MedlinePlus

    ... this page: About CDC.gov . Redirect for the Rubella fact sheet page. The current fact sheet can ... http://www.cdc.gov/vaccines/parents/diseases/child/rubella.html Print page Share Compartir File Formats Help: ...

  18. Fast Light-Sheet Scanner

    NASA Technical Reports Server (NTRS)

    Hunter, William W., Jr.; Humphreys, William M., Jr.; Bartram, Scott M.

    1995-01-01

    Optomechanical apparatus maintains sheet of pulsed laser light perpendicular to reference axis while causing sheet of light to translate in oscillatory fashion along reference axis. Produces illumination for laser velocimeter in which submicrometer particles entrained in flow illuminated and imaged in parallel planes displaced from each other in rapid succession. Selected frequency of oscillation range upward from tens of hertz. Rotating window continuously shifts sheet of light laterally while maintaining sheet parallel to same plane.

  19. Transparency in a Pediatric Quality Improvement Collaborative: A Passionate Journey by NPC-QIC Clinicians and Parents.

    PubMed

    Lihn, Stacey L; Kugler, John D; Peterson, Laura E; Lannon, Carole M; Pickles, Diane; Beekman, Robert H

    2015-01-01

    Transparency-sharing data or information about outcomes, processes, protocols, and practices-may be the most powerful driver of health care improvement. In this special article, the development and growth of transparency within the National Pediatric Cardiology Quality Improvement Collaborative is described. The National Pediatric Cardiology Quality Improvement Collaborative transparency journey is guided by equal numbers of clinicians and parents of children with congenital heart disease working together in a Transparency Work Group. Activities are organized around four interrelated levels of transparency (individual, organizational, collaborative, and system), each with a specified purpose and aim. A number of Transparency Work Group recommendations have been operationalized. Aggregate collaborative performance is now reported on the public-facing web site. Specific information that the Transparency Work Group recommends centers provide to parents has been developed and published. Almost half of National Pediatric Cardiology Quality Improvement Collaborative centers participated in a pilot of transparently sharing their outcomes achieved with one another. Individual centers have also begun successfully implementing recommended transparency activities. Despite progress, barriers to full transparency persist, including health care organization concerns about potential negative effects of disclosure on reputation and finances, and lack of reliable definitions, data, and reporting standards for fair comparisons of centers. The National Pediatric Cardiology Quality Improvement Collaborative's transparency efforts have been a journey that continues, not a single goal or destination. Balanced participation of clinicians and parents has been a critical element of the collaborative's success on this issue. Plans are in place to guide implementation of additional transparency recommendations across all four levels, including extension of the activities beyond the

  20. A Simple, Transparent Fume Hood

    NASA Astrophysics Data System (ADS)

    Fredericks, John

    1998-10-01

    An inexpensive transparent fume hood can be constructed from a clear-plastic two-liter soft drink bottle that is cut just above the base. A length of vacuum tubing is secured to the opening of the bottle using black electrical tape. The tubing is then connected to a water aspirator. Beakers or flasks easily fit inside the bottle, and the bottle may be secured with a clamp and ring stand for added stability. This device has been used to collect the noxious NO2 gas generated from the reaction of copper metal with nitric acid. It also may be used in the collection of other gases. It should not be used to collect gases that are not water-soluble or in experiments that involve open flames.

  1. Broadband cavity electromagnetically induced transparency

    SciTech Connect

    Wei Xiaogang; Wang Yanhua; Zhang Jiepeng; Zhu Yifu

    2011-10-15

    Cavity electromagnetically induced transparency (EIT) is created in a three-level atomic system confined in a cavity and coupled to a free-space control laser and is manifested as a narrow transmission peak of a probe laser coupled into the cavity mode and tuned to the two-photon Raman resonance with the control laser. Cavity EIT can be observed with a control laser detuned from the atomic transition frequency in a range limited by the vacuum Rabi splitting of two cavity-atom normal modes. This leads to the broadband cavity EIT obtained in the coupled-cavity-atom system with a free-space, broadband control laser. We report an experimental observation of broadband cavity EIT in cold Rb atoms with a frequency-modulated control laser and discuss its application in multichannel and multifrequency light memory.

  2. Biometrics between opacity and transparency.

    PubMed

    Gutwirth, Serge

    2007-01-01

    The overall aim of the democratic constitutional state is to protect a social order in which the individual liberty of the citizen is a major concern. As a consequence the democratic constitutional state should guarantee simultaneously and paradoxically a high level of individual freedom and an order in which such freedom is made possible and guaranteed. Biometrics provide a strong and expressive example both of the necessity to address the issue of opacity and transparency and the complexity of the process. Indeed, the large scale use of biometrics does not only question the position of the individual in society, but it also alters the architecture or nature of this society as such. PMID:17536155

  3. Plasma sheet ion energization during dipolarization events

    SciTech Connect

    Delcourt, D.C. ); Sauvaud, J.A. )

    1994-01-01

    This paper presents simulation results for acceleration processes for ions during what are referred to as dipolarization events associated with storm activity. Time variations of magnetic fields over cyclotron periods, and generation of electric fields parallel to the geomagnetic field, both contribute to ion acceleration in the plasma sheet. Calculations support the observation of earthward injection of ions during such events.

  4. Bromination of Graphene: A New Route to Making High Performance Transparent Conducting Electrodes with Low Optical Losses.

    PubMed

    Mansour, Ahmed E; Dey, Sukumar; Amassian, Aram; Tanielian, Minas H

    2015-08-19

    The unique optical and electrical properties of graphene have triggered great interest in its application as a transparent conducting electrode material and significant effort has been invested in achieving high conductivity while maintaining high transparency. Doping of graphene has been a popular route for reducing its sheet resistance, but this has typically come at a significant loss in optical transmittance. We demonstrate doping of few layers graphene (FLG) with bromine as a means of enhancing the conductivity via intercalation without major optical losses. Our results demonstrate the encapsulation of bromine within the FLG, leading to air-stable transparent conducting electrodes with 5-fold improvement of sheet resistance reaching ∼180 Ω/□ at the cost of only 2-3% loss of optical transmittance. The remarkably low trade-off in optical transparency leads to the highest enhancements in the figure of merit reported thus far for FLG. Furthermore, we tune the work function by up to 0.3 eV by tuning the bromine content. These results should help pave the way for further development of graphene as a potential substitute to transparent conducting polymers and metal oxides used in optoelectronics, photovoltaics, and beyond. PMID:26200126

  5. Oxidation-resistant hybrid metal oxides/metal nanodots/silver nanowires for high performance flexible transparent heaters.

    PubMed

    Kim, A-Young; Kim, Min Kyu; Hudaya, Chairul; Park, Ji Hun; Byun, Dongjin; Lim, Jong Choo; Lee, Joong Kee

    2016-02-14

    Despite its excellent optical, electrical, mechanical, and thermal performances, a silver nanowire (AgNW)-based transparent conducting heater (TCH) still demonstrates several drawbacks such as facile nanowire breakdown on application of a high DC voltage, easy oxidation when exposed to harsh environments, leading to increased surface resistivity, and high resistance among wire junctions causing nonhomogeneous temperature profiles. To overcome these issues, the AgNW was hybridized with other transparent heating materials made of fluorine-doped tin oxide (FTO) thin films and NiCr nanodots (FTO/NiCr/AgNW). The dispersed NiCr nanodots (∼50 nm) and FTO thin films (∼20 nm) electrically bridge the nanowire junctions leading to a decreased sheet resistance and uniform temperature profiles. The hybrid transparent heater shows excellent optical transmittance (>90%) and high saturation temperature (162 °C) at low applied DC voltage (6 V). Moreover, the FTO/NiCr/AgNW heater exhibits a stable sheet resistance in a hostile environment, hence highlighting the excellent oxidation-resistance of the heating materials. These results indicate that the proposed hybrid transparent heaters could be a promising approach to combat the inherent problems associated with AgNW-based transparent heaters for various functional applications. PMID:26515282

  6. Skill Sheets for Agricultural Mechanics.

    ERIC Educational Resources Information Center

    Iowa State Univ. of Science and Technology, Ames. Dept. of Agricultural Education.

    This set of 33 skill sheets for agricultural mechanics was developed for use in high school and vocational school agricultural mechanics programs. Some sheets teach operational procedures while others are for simple projects. Each skill sheet covers a single topic and includes: (1) a diagram, (2) a step-by-step construction or operational…

  7. Beginning Child Care Fact Sheets.

    ERIC Educational Resources Information Center

    Tweedie, Pat

    These six fact sheets from Child Care Aware are designed to help parents ease their children's transition to child care. The first fact sheet, "Before Your Child's First Day," discusses tips such as: (1) "prepare your child"; (2) read and look at picture books about child care; and (3) "prepare yourself." The second fact sheet, "First Day Tips,"…

  8. The Physics of Ice Sheets

    ERIC Educational Resources Information Center

    Bassis, J. N.

    2008-01-01

    The great ice sheets in Antarctica and Greenland are vast deposits of frozen freshwater that contain enough to raise sea level by approximately 70 m if they were to completely melt. Because of the potentially catastrophic impact that ice sheets can have, it is important that we understand how ice sheets have responded to past climate changes and…

  9. Atomically Bonded Transparent Superhydrophobic Coatings

    SciTech Connect

    Aytug, Tolga

    2015-08-01

    Maintaining clarity and avoiding the accumulation of water and dirt on optically transparent surfaces such as US military vehicle windshields, viewports, periscope optical head windows, and electronic equipment cover glasses are critical to providing a high level of visibility, improved survivability, and much-needed safety for warfighters in the field. Through a combination of physical vapor deposition techniques and the exploitation of metastable phase separation in low-alkali borosilicate, a novel technology was developed for the fabrication of optically transparent, porous nanostructured silica thin film coatings that are strongly bonded to glass platforms. The nanotextured films, initially structurally superhydrophilic, exhibit superior superhydrophobicity, hence antisoiling ability, following a simple but robust modification in surface chemistry. The surfaces yield water droplet contact angles as high as 172°. Moreover, the nanostructured nature of these coatings provides increased light scattering in the UV regime and reduced reflectivity (i.e., enhanced transmission) over a broad range of the visible spectrum. In addition to these functionalities, the coatings exhibit superior mechanical resistance to abrasion and are thermally stable to temperatures approaching 500°C. The overall process technology relies on industry standard equipment and inherently scalable manufacturing processes and demands only nontoxic, naturally abundant, and inexpensive base materials. Such coatings, applied to the optical components of current and future combat equipment and military vehicles will provide a significant strategic advantage for warfighters. The inherent self-cleaning properties of such superhydrophobic coatings will also mitigate biofouling of optical windows exposed to high-humidity conditions and can help decrease repair/replacement costs, reduce maintenance, and increase readiness by limiting equipment downtime.

  10. Carbon Nanotube Assemblies for Transparent Conducting Electrodes

    SciTech Connect

    Garrett, Matthew P; Gerhardt, Rosario

    2012-01-01

    The goal of this chapter is to introduce readers to the fundamental and practical aspects of nanotube assemblies made into transparent conducting networks and discuss some practical aspects of their characterization. Transparent conducting coatings (TCC) are an essential part of electro-optical devices, from photovoltaics and light emitting devices to electromagnetic shielding and electrochromic widows. The market for organic materials (including nanomaterials and polymers) based TCCs is expected to show a growth rate of 56.9% to reach nearly 20.3billionin2015,whilethemarketfortraditionalinorganictransparentelectronicswillexperiencegrowthwithratesof6.7103 billion in 2015. Emerging flexible electronic applications have brought additional requirements of flexibility and low cost for TCC. However, the price of indium (the major component in indium tin oxide TCC) continues to increase. On the other hand, the price of nanomaterials has continued to decrease due to development of high volume, quality production processes. Additional benefits come from the low cost, nonvacuum deposition of nanomaterials based TCC, compared to traditional coatings requiring energy intensive vacuum deposition. Among the materials actively researched as alternative TCC are nanoparticles, nanowires, and nanotubes with high aspect ratio as well as their composites. The figure of merit (FOM) can be used to compare TCCs made from dissimilar materials and with different transmittance and conductivity values. In the first part of this manuscript, we will discuss the seven FOM parameters that have been proposed, including one specifically intended for flexible applications. The approach for how to measure TCE electrical properties, including frequency dependence, will also be discussed. We will relate the macroscale electrical characteristics of TCCs to the nanoscale parameters of conducting networks. The fundamental aspects of nanomaterial assemblies in conducting networks will also be addressed

  11. 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.

  12. Clouds enhance Greenland ice sheet meltwater runoff

    NASA Astrophysics Data System (ADS)

    van Tricht, K.; Lhermitte, S.; Lenaerts, J. T. M.; Gorodetskaya, I. V.; L'Ecuyer, T. S.; Noël, B.; van den Broeke, M. R.; Turner, D. D.; van Lipzig, N. P. M.

    2016-01-01

    The Greenland ice sheet has become one of the main contributors to global sea level rise, predominantly through increased meltwater runoff. The main drivers of Greenland ice sheet runoff, however, remain poorly understood. Here we show that clouds enhance meltwater runoff by about one-third relative to clear skies, using a unique combination of active satellite observations, climate model data and snow model simulations. This impact results from a cloud radiative effect of 29.5 (+/-5.2) W m-2. Contrary to conventional wisdom, however, the Greenland ice sheet responds to this energy through a new pathway by which clouds reduce meltwater refreezing as opposed to increasing surface melt directly, thereby accelerating bare-ice exposure and enhancing meltwater runoff. The high sensitivity of the Greenland ice sheet to both ice-only and liquid-bearing clouds highlights the need for accurate cloud representations in climate models, to better predict future contributions of the Greenland ice sheet to global sea level rise.

  13. Clouds enhance Greenland ice sheet meltwater runoff

    NASA Astrophysics Data System (ADS)

    Van Tricht, Kristof; Lhermitte, Stef; Lenaerts, Jan T. M.; Gorodetskaya, Irina V.; L'Ecuyer, Tristan S.; Noël, Brice; van den Broeke, Michiel R.; Turner, David D.; van Lipzig, Nicole P. M.

    2016-04-01

    The Greenland ice sheet has become one of the main contributors to global sea level rise, predominantly through increased meltwater runoff. The main drivers of Greenland ice sheet runoff, however, remain poorly understood. Here we show that clouds enhance meltwater runoff by about one-third relative to clear skies, using a unique combination of active satellite observations, climate model data and snow model simulations. This impact results from a cloud radiative effect of 29.5 (±5.2) W m‑2. Contrary to conventional wisdom, however, the Greenland ice sheet responds to this energy through a new pathway by which clouds reduce meltwater refreezing as opposed to increasing surface melt directly, thereby accelerating bare-ice exposure and enhancing meltwater runoff. The high sensitivity of the Greenland ice sheet to both ice-only and liquid-bearing clouds highlights the need for accurate cloud representations in climate models, to better predict future contributions of the Greenland ice sheet to global sea level rise.

  14. Clouds enhance Greenland ice sheet meltwater runoff

    PubMed Central

    Van Tricht, K.; Lhermitte, S.; Lenaerts, J. T. M.; Gorodetskaya, I. V.; L'Ecuyer, T. S.; Noël, B.; van den Broeke, M. R.; Turner, D. D.; van Lipzig, N. P. M.

    2016-01-01

    The Greenland ice sheet has become one of the main contributors to global sea level rise, predominantly through increased meltwater runoff. The main drivers of Greenland ice sheet runoff, however, remain poorly understood. Here we show that clouds enhance meltwater runoff by about one-third relative to clear skies, using a unique combination of active satellite observations, climate model data and snow model simulations. This impact results from a cloud radiative effect of 29.5 (±5.2) W m−2. Contrary to conventional wisdom, however, the Greenland ice sheet responds to this energy through a new pathway by which clouds reduce meltwater refreezing as opposed to increasing surface melt directly, thereby accelerating bare-ice exposure and enhancing meltwater runoff. The high sensitivity of the Greenland ice sheet to both ice-only and liquid-bearing clouds highlights the need for accurate cloud representations in climate models, to better predict future contributions of the Greenland ice sheet to global sea level rise. PMID:26756470

  15. Fully solution-processed transparent electrodes based on silver nanowire composites for perovskite solar cells

    NASA Astrophysics Data System (ADS)

    Kim, Areum; Lee, Hongseuk; Kwon, Hyeok-Chan; Jung, Hyun Suk; Park, Nam-Gyu; Jeong, Sunho; Moon, Jooho

    2016-03-01

    We report all-solution-processed transparent conductive electrodes based on Ag nanowire (AgNW)-embedded metal oxide composite films for application in organometal halide perovskite solar cells. To address the thermal instability of Ag nanowires, we used combustive sol-gel derived thin films to construct ZnO/ITO/AgNW/ITO composite structures. The resulting composite configuration effectively prevented the AgNWs from undergoing undesirable side-reactions with halogen ions present in the perovskite precursor solutions that significantly deteriorate the optoelectrical properties of Ag nanowires in transparent conductive films. AgNW-based composite electrodes had a transmittance of ~80% at 550 nm and sheet resistance of 18 Ω sq-1. Perovskite solar cells fabricated using a fully solution-processed transparent conductive electrode, Au/spiro-OMeTAD/CH3NH3PbI3 + m-Al2O3/ZnO/ITO/AgNW/ITO, exhibited a power conversion efficiency of 8.44% (comparable to that of the FTO/glass-based counterpart at 10.81%) and were stable for 30 days in ambient air. Our results demonstrate the feasibility of using AgNWs as a transparent bottom electrode in perovskite solar cells produced by a fully printable process.We report all-solution-processed transparent conductive electrodes based on Ag nanowire (AgNW)-embedded metal oxide composite films for application in organometal halide perovskite solar cells. To address the thermal instability of Ag nanowires, we used combustive sol-gel derived thin films to construct ZnO/ITO/AgNW/ITO composite structures. The resulting composite configuration effectively prevented the AgNWs from undergoing undesirable side-reactions with halogen ions present in the perovskite precursor solutions that significantly deteriorate the optoelectrical properties of Ag nanowires in transparent conductive films. AgNW-based composite electrodes had a transmittance of ~80% at 550 nm and sheet resistance of 18 Ω sq-1. Perovskite solar cells fabricated using a fully solution

  16. Direct synthesis of graphene 3D-coated Cu nanosilks network for antioxidant transparent conducting electrode

    NASA Astrophysics Data System (ADS)

    Xu, Hongmei; Wang, Huachun; Wu, Chenping; Lin, Na; Soomro, Abdul Majid; Guo, Huizhang; Liu, Chuan; Yang, Xiaodong; Wu, Yaping; Cai, Duanjun; Kang, Junyong

    2015-06-01

    Transparent conducting film occupies an important position in various optoelectronic devices. To replace the costly tin-doped indium oxide (ITO), promising materials, such as metal nanowires and graphene, have been widely studied. Moreover, a long-pursued goal is to consolidate these two materials together and express their outstanding properties simultaneously. We successfully achieved a direct 3D coating of a graphene layer on an interlacing Cu nanosilks network by the low pressure chemical vapor deposition method. High aspect ratio Cu nanosilks (13 nm diameter with 40 μm length) were synthesized through the nickel ion catalytic process. Large-size, transparent conducting film was successfully fabricated with Cu nanosilks ink by the imprint method. A magnetic manipulator equipped with a copper capsule was used to produce high Cu vapor pressure on Cu nanosilks and realize the graphene 3D-coating. The coated Cu@graphene nanosilks network achieved high transparency, low sheet resistance (41 Ohm sq-1 at 95% transmittance) and robust antioxidant ability. With this technique, the transfer process of graphene is no longer needed, and a flexible, uniform and high-performance transparent conducting film could be fabricated in unlimited size.Transparent conducting film occupies an important position in various optoelectronic devices. To replace the costly tin-doped indium oxide (ITO), promising materials, such as metal nanowires and graphene, have been widely studied. Moreover, a long-pursued goal is to consolidate these two materials together and express their outstanding properties simultaneously. We successfully achieved a direct 3D coating of a graphene layer on an interlacing Cu nanosilks network by the low pressure chemical vapor deposition method. High aspect ratio Cu nanosilks (13 nm diameter with 40 μm length) were synthesized through the nickel ion catalytic process. Large-size, transparent conducting film was successfully fabricated with Cu nanosilks ink by

  17. Ice-sheet response to oceanic forcing.

    PubMed

    Joughin, Ian; Alley, Richard B; Holland, David M

    2012-11-30

    The ice sheets of Greenland and Antarctica are losing ice at accelerating rates, much of which is a response to oceanic forcing, especially of the floating ice shelves. Recent observations establish a clear correspondence between the increased delivery of oceanic heat to the ice-sheet margin and increased ice loss. In Antarctica, most of these processes are reasonably well understood but have not been rigorously quantified. In Greenland, an understanding of the processes by which warmer ocean temperatures drive the observed retreat remains elusive. Experiments designed to identify the relevant processes are confounded by the logistical difficulties of instrumenting ice-choked fjords with actively calving glaciers. For both ice sheets, multiple challenges remain before the fully coupled ice-ocean-atmosphere models needed for rigorous sea-level projection are available. PMID:23197526

  18. 3 CFR - Transparency and Open Government

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 3 The President 1 2010-01-01 2010-01-01 false Transparency and Open Government Presidential Documents Other Presidential Documents Memorandum of January 21, 2009 Transparency and Open Government Memorandum for the Heads of Executive Departments and Agencies My Administration is committed to creating an unprecedented level of openness...

  19. Highly Anisotropic, Highly Transparent Wood Composites.

    PubMed

    Zhu, Mingwei; Song, Jianwei; Li, Tian; Gong, Amy; Wang, Yanbin; Dai, Jiaqi; Yao, Yonggang; Luo, Wei; Henderson, Doug; Hu, Liangbing

    2016-07-01

    For the first time, two types of highly anisotropic, highly transparent wood composites are demonstrated by taking advantage of the macro-structures in original wood. These wood composites are highly transparent with a total transmittance up to 90% but exhibit dramatically different optical and mechanical properties. PMID:27147136

  20. Free-standing carbon nanotube-titania photoactive sheets.

    PubMed

    Koo, Youngmi; Malik, Rachit; Alvarez, Noe; Shanov, Vesselin N; Schulz, Mark; Sankar, Jag; Yun, Yeoheung

    2015-06-15

    We report on the development of a new photoactive material via titania (TiO2) nanoparticle deposition on free-standing aligned carbon nanotube (CNT) sheets. Controlling homogeneous dispersion of negatively charged TiO2 nanoparticles, achieved by adjusting pH higher than the point of zero charge (PZC), influenced electrochemical deposition of TiO2 on CNT sheets substrate. Varying deposition time with constant voltage, 5 V allowed different thickness of TiO2 to be deposited layer on the CNT sheets. The thickness and morphology of CNT-TiO2 sheets was verified by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). Electrochemical experiments show that diffusion coefficient of Fe(CN)6(3-) was 5.56×10(-6) cm(2) s(-1) at pristine CNT sheets and 2.19×10(-6) cm(2) s(-1) at the CNT-TiO2 sheets. Photocatalytic activity for CNT-TiO2 sheets exhibits high photocurrent density (when deposition time=30 min, 4.3 μA cm(-2) in N2, 13.4 μA cm(-2) in CO2). This paper proved a possibility to use CNT-TiO2 sheets based on highly-aligned CNT sheets substrate as new photoactive material. PMID:25725399

  1. Self-cleaning properties, mechanical stability, and adhesion strength of transparent photocatalytic TiO(2)-ZnO coatings on polycarbonate.

    PubMed

    Fateh, Razan; Dillert, Ralf; Bahnemann, Detlef

    2014-02-26

    Transparent layers containing TiO2 have been intensively studied because of their interesting application potential including photocatalytically active and self-cleaning surfaces. In the present work, transparent TiO2-ZnO thin films on a SiO2 interlayer were successfully deposited on the surface of polycarbonate to provide polymeric sheets with a self-cleaning, superhydrophilic, and photocatalytically active surface layer. To ensure a good adhesion of the SiO2 interlayer, the polycarbonate sheets were first modified by irradiation with UV(C) light. The prepared films were characterized by UV/vis spectrophotometry, SEM, XRD, Raman spectroscopy, ellipsometry, and water contact-angle measurements. All prepared films are transparent, have thicknesses in the range between 120 and 250 nm, and possess superhydrophilic properties. Moreover, they exhibit good adhesion qualities as defined quantitatively by cross-cut tests. However, their mechanical strengths, checked by felt-abrasion tests, differ by changing the molar TiO2-ZnO ratio. The photocatalytic activity, expressed as photonic efficiency, of the coated surfaces was estimated from the kinetics of the photocatalytic degradation of methylene blue and methyl stearate. The combination between superhydrophilic properties and photocatalytic activity was determined by studying the change of water contact angle during the storage of the prepared films in the dark under an ambient atmosphere and under an atmosphere containing either acetone or isopropanol followed by UV(A) irradiation. In addition, self-cleaning properties were examined by determining the changes in the contact angle during the irradiation time after applying oleic acid to the surface. The results show that increasing the molar ratio of ZnO in TiO2 coatings up to 5% yields maximum photonic efficiency values of 0.023%, as assessed by the photocatalytic degradation of methylene blue. Moreover, the superhydrophilic coating with a molar TiO2-ZnO ratio of 1

  2. Anisotropy-Induced Transparency in Optically Dense Media

    NASA Astrophysics Data System (ADS)

    Tokman, M. D.; Erukhimova, M. A.

    2015-04-01

    The effect of anisotropy-induced transparency, which is analogous to electromagnetically induced transparency in the three-level medium located in a resonance field, is predicted and studied theoretically. This effect is connected with destructive interference between oscillations in different degrees of freedom of an anisotropic medium, which are connected with each other, as radiation propagates at an angle to one of the optical axes in a triaxial or uniaxial crystal. In this case, a hybrid-type polariton is formed in the "transparency window," which combines the quasi-longitudinal polarization with the "vacuum" refractive index. Such a wave is excited easily by radiation incident from the vacuum and should have enhanced impedance of coupling with active or nonlinear elements, which can be useful for the creation of small-size optical systems. Due to the interest in quantum-optical effects displayed recently, the regime of anisotropy-induced transparency is considered within the framework of the quantum theory of radiation in an optically dense medium.

  3. Indium tin oxide-free transparent and conductive electrode based on SnO{sub x} | Ag | SnO{sub x} for organic solar cells

    SciTech Connect

    Bou, A.; Torchio, Ph. Barakel, D.; Thierry, F.; Sangar, A.; Thoulon, P.-Y.; Ricci, M.

    2014-07-14

    A SnO{sub x} | Ag | SnO{sub x} multilayer deposited by E-beam evaporation is proposed as transparent anode for a (poly-3-hexylthiophene):[6,6]-phenyl-C{sub 61}-butyric acid methyl ester (P3HT:PCBM) bulk heterojunction based Organic Solar Cell (OSC). Such multilayers are studied and manufactured with the objective to give to the electrode its best conductivity and transparency in the visible spectral range. A transfer matrix method numerical optimization of the thicknesses of each layer of the electrode is developed to limit the number of test samples which would have been manufactured whether an empirical method was chosen. Optical characterization of the deposited SnO{sub x} and Ag thin films is performed to determine the dispersion of the complex refractive indices which are used as input parameters in the model. A satisfying agreement between numerical and experimental optical properties is found. The bare tri-layer electrodes show low sheet resistance (as low as 6.7 Ω/□) and the whole Glass | SnO{sub x} | Ag | SnO{sub x} structure presents a mean transparency on 400–700 nm spectral band as high as 67%. The multilayer is then numerically studied as anode for a P3HT:PCBM bulk heterojunction based OSC. Intrinsic absorption inside the sole active layer is calculated giving the possibility to perform optical optimization on the intrinsic absorption efficiency inside the active area by considering the media embedding the electrodes. An additional study using the morphology of the silver inserted between both oxide layers as input data is performed with a finite difference time domain 3D-method to improve the accordance between optical measurements and numerical results.

  4. Oboe Transparency Results - Oboes 1-9

    SciTech Connect

    Heinle, R A

    2002-10-15

    The motivation for the ''Transparency'' experiment is that DOE/DP would like to have data available to show to interested parties, such as the JASONs. The U1a subcritical experiments are consistent with U.S. policy on nuclear testing. This would be done in a spirit of ''Transparency'' if doubts should arise. Thus, the objective of the ''Transparency'' measurements on the Oboe series is to place an upper bound on the nuclear energy released in the subcritical experiments. Two separate experimental packages cover the transparency measurement issue thoroughly. These are: (1) Neutron Track-Etch Dosimetry. (2) Scintillator Fission Neutron/Gamma Rate Measurement. Because the containment barrier is only 1-inch steel, plus 6-inch shotcrete, it is quite transparent to fission neutrons and, thus, both experiments can be mounted outside the containment barrier and can be recovered post shot. An additional group of dosimeters was placed on the lid of the vessel for greater sensitivity.

  5. Tunable Broadband Printed Carbon Transparent Conductor

    NASA Astrophysics Data System (ADS)

    Xu, Yue; Wan, Jiayu

    Transparent conductors have been widely applied in solar cells, transparent smart skins, and sensing/imaging antennas, etc. Carbon-based transparent conductor has attracted great attention for its low cost and broad range transparency. Ion intercalation has been known to highly dope graphitic materials, thereby tuning materials' optoelectronic properties. For the first time, we successfully tune the optical transmittance of a reduced graphene oxide (RGO)/CNT network from mid-IR range to visible range by means of Li-ion intercalation/deintercalation. We also observed a simultaneous increase of the electrical conductivity with the Li-ion intercalation. This printed carbon hybrid thin film was prepared through all solution processes and was easily scalable. This study demonstrates the possibility of using ion intercalation for low cost, tunable broadband transparent conductors.

  6. Temporal variations of membrane foulants in the process of using flat-sheet membrane for simultaneous thickening and digestion of waste activated sludge.

    PubMed

    Wu, Zhichao; Zhu, Xuefeng; Wang, Zhiwei

    2011-07-01

    Membrane foulants were extracted at different operation time in simultaneous sludge thickening and digestion reactors using flat-sheet membranes. Temporal variations of foulants were analyzed by three-dimensional excitation-emission matrix (EEM) fluorescence spectroscopy, gel filtration chromatography (GFC), particle size distribution (PSD) and attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy. Results showed that during the first 4days fouling was mainly assigned to internal membrane foulants (IMFs), and afterwards external membrane foulants (EMFs) increased dramatically. EEM analysis showed that both IMFs and EMFs changed during the operation. Cluster analysis demonstrated that the characteristics of IMFs were relatively similar; however, both quantity and properties of EMFs were changed. GFC analysis showed that EMFs contained more molecules with large molecular weight compared to IMFs. PSD analysis illuminated that particle size of EMFs gradually increased and was larger than that of IMFs. ATR-FTIR analysis indicated that the foulants on membranes consisted of polysaccharides and proteins. PMID:21555218

  7. Calcium ion-induced formation of β-sheet/-turn structure leading to alteration of osteogenic activity of bone morphogenetic protein-2

    PubMed Central

    Zhang, Wenjing; He, Hongyan; Tian, Yu; Gan, Qi; Zhang, Jing; Yuan, Yuan; Liu, Changsheng

    2015-01-01

    Preserving bioactivity of bone morphogenetic protein 2 (BMP-2) still remains a challenge in protein-based therapy. It is not known how Ca2+ released from extracellular matrix or existing in physiological environment influences bioactivity in situ till now. Here, effects of extracellular Ca2+ on conformation and osteogenic bioactivity of recombinant human BMP-2 (rhBMP-2) were investigated systematically. In vitro results indicated that Ca2+ could bind rhBMP-2 rapidly and had no obvious effect on cell behaviors. Low concentration of Ca2+ (0.18 mM) enhanced rhBMP-2-induced osteogenic differentiation, while high Ca2+ concentration (>1.80 mM) exerted negative effect. In vivo ectopic bone formation exhibited similar trend. Further studies by circular dichroism spectroscopy, fluorescence spectroscopy, together with cell culture experiments revealed at low concentration, weak interaction of Ca2+ and rhBMP-2 slightly increased β-sheet/-turn content and facilitated recognition of BMP-2 and BMPRIA. But, high Ca2+ concentration (>1.8 mM) induced formation of Ca-rhBMP-2 complex and markedly increased content of β-sheet/-turn, which led to inhibition binding of rhBMP-2 and BMPRIA and thus suppression of downstream Smad1/5/8, ERK1/2 and p38 mitogen-associated protein kinase signaling pathways. Our work suggests osteogenic bioactivity of BMP-2 can be adjusted via extracellular Ca2+, which should provide guide and assist for development of BMP-2-based materials for bone regeneration. PMID:26212061

  8. SHEET PLASMA DEVICE

    DOEpatents

    Henderson, O.A.

    1962-07-17

    An ion-electron plasma heating apparatus of the pinch tube class was developed wherein a plasma is formed by an intense arc discharge through a gas and is radially constricted by the magnetic field of the discharge. To avoid kink and interchange instabilities which can disrupt a conventional arc shortiy after it is formed, the apparatus is a pinch tube with a flat configuration for forming a sheet of plasma between two conductive plates disposed parallel and adjacent to the plasma sheet. Kink instabilities are suppressed by image currents induced in the conductive plates while the interchange instabilities are neutrally stable because of the flat plasma configuration wherein such instabilities may occur but do not dynamically increase in amplitude. (AEC)

  9. Biomolecular Science (Fact Sheet)

    SciTech Connect

    Not Available

    2012-04-01

    A brief fact sheet about NREL Photobiology and Biomolecular Science. The research goal of NREL's Biomolecular Science is to enable cost-competitive advanced lignocellulosic biofuels production by understanding the science critical for overcoming biomass recalcitrance and developing new product and product intermediate pathways. NREL's Photobiology focuses on understanding the capture of solar energy in photosynthetic systems and its use in converting carbon dioxide and water directly into hydrogen and advanced biofuels.

  10. Topographical atlas sheets

    USGS Publications Warehouse

    Wheeler, George Montague

    1876-01-01

    The following topographical atlas sheets, accompanying Appendix J.J. of the Annual Report of the Chief of Engineers, U.S. Army-being Annual Report upon U. S. Geographical Surveys-have been published during the fiscal year ending June 30, 1876, and are a portion of the series projected to embrace the territory of the United States lying west of the 100th meridian.

  11. Silicon sheet surface studies

    NASA Astrophysics Data System (ADS)

    Danyluk, S.

    1985-06-01

    Results of the program are presented on developing an understanding of the basic mechanisms of abrasion and wear of silicon and on the nondestructive measurement of residual stresses in sheet silicon. Experiments were conducted at various temperatures and in the presence of various fluids. In abrasive wear, it was shown that dislocations, microtwins, and cracks are generated beneath the contact surface. Residual stresses in ribbon by the edge defined film growth process were measured by use of a shadow moire interferometry technique.

  12. Clean Cities Fact Sheet

    SciTech Connect

    Not Available

    2004-01-01

    This fact sheet explains the Clean Cities Program and provides contact information for all coalitions and regional offices. It answers key questions such as: What is the Clean Cities Program? What are alternative fuels? How does the Clean Cities Program work? What sort of assistance does Clean Cities offer? What has Clean Cities accomplished? What is Clean Cities International? and Where can I find more information?

  13. Enhanced transparent conducting networks on plastic substrates modified with highly oxidized graphene oxide nanosheets.

    PubMed

    Woo, Jong Seok; Sin, Dong Hun; Kim, Haena; Jang, Jeong In; Kim, Ho Young; Lee, Geon-Woong; Cho, Kilwon; Park, Soo-Young; Han, Joong Tark

    2016-03-28

    Atomically thin and two-dimensional graphene oxide (GO) is a very fascinating material because of its functional groups, high transparency, and solution processability. Here we show that highly oxidized GO (HOGO) nanosheets serve as an effective interfacial modifier of transparent conducting films with one-dimensional (1D) silver nanowires (AgNWs) and single-walled carbon nanotubes (SWCNTs). Optically transparent and small-sized GO nanosheets, with minimal sp(2) domains, were successfully fabricated by step-wise oxidation and exfoliation of graphite. We demonstrated that under-coated HOGO further decreases the sheet resistance of the SWCNT film top-coated with HOGO by increasing the contact area between the SWCNTs and HOGO nanosheets by generating hole carriers in the SWCNT as a result of charge transfer. Moreover, HOGO nanosheets with AgNWs contribute to the efficient thermal joining of AgNW networks on plastic substrates by limiting the thermal embedding of AgNWs into the plastic surface, resulting in efficient decrease of the sheet resistance. Furthermore, flexible organic photovoltaic cells with GO-modified AgNW anodes on a flexible substrate were successfully demonstrated. PMID:26946993

  14. An Ag-grid/graphene hybrid structure for large-scale, transparent, flexible heaters.

    PubMed

    Kang, Junmo; Jang, Yonghee; Kim, Youngsoo; Cho, Seung-Hyun; Suhr, Jonghwan; Hong, Byung Hee; Choi, Jae-Boong; Byun, Doyoung

    2015-04-21

    Recently, carbon materials such as carbon nanotubes and graphene have been proposed as alternatives to indium tin oxide (ITO) for fabricating transparent conducting materials. However, obtaining low sheet resistance and high transmittance of these carbon materials has been challenging due to the intrinsic properties of the materials. In this paper, we introduce highly transparent and flexible conductive films based on a hybrid structure of graphene and an Ag-grid. Electrohydrodynamic (EHD) jet printing was used to produce a micro-scale grid consisting of Ag lines less than 10 μm wide. We were able to directly write the Ag-grid on a large-area graphene/flexible substrate due to the high conductivity of graphene. The hybrid electrode could be fabricated using hot pressing transfer and EHD jet printing in a non-vacuum, maskless, and low-temperature environment. The hybrid electrode offers an effective and simple route for achieving a sheet resistance as low as ∼4 Ω per square with ∼78% optical transmittance. Finally, we demonstrate that transparent flexible heaters based on the hybrid conductive films could be used in a vehicle or a smart window system. PMID:25790123

  15. High-performance NiO/Ag/NiO transparent electrodes for flexible organic photovoltaic cells.

    PubMed

    Xue, Zhichao; Liu, Xingyuan; Zhang, Nan; Chen, Hong; Zheng, Xuanming; Wang, Haiyu; Guo, Xiaoyang

    2014-09-24

    Transparent electrodes with a dielectric-metal-dielectric (DMD) structure can be implemented in a simple manufacturing process and have good optical and electrical properties. In this study, nickel oxide (NiO) is introduced into the DMD structure as a more appropriate dielectric material that has a high conduction band for electron blocking and a low valence band for efficient hole transport. The indium-free NiO/Ag/NiO (NAN) transparent electrode exhibits an adjustable high transmittance of ∼82% combined with a low sheet resistance of ∼7.6 Ω·s·q(-1) and a work function of 5.3 eV after UVO treatment. The NAN electrode shows excellent surface morphology and good thermal, humidity, and environmental stabilities. Only a small change in sheet resistance can be found after NAN electrode is preserved in air for 1 year. The power conversion efficiencies of organic photovoltaic cells with NAN electrodes deposited on glass and polyethylene terephthalate (PET) substrates are 6.07 and 5.55%, respectively, which are competitive with those of indium tin oxide (ITO)-based devices. Good photoelectric properties, the low-cost material, and the room-temperature deposition process imply that NAN electrode is a striking candidate for low-cost and flexible transparent electrode for efficient flexible optoelectronic devices. PMID:25148532

  16. Temperature and voltage dependent current-voltage behavior of single-walled carbon nanotube transparent conducting films

    NASA Astrophysics Data System (ADS)

    Zhang, Ze-Chen; Geng, Hong-Zhang; Wang, Yan; Yang, Hai-Jie; Da, Shi-Xun; Ding, Er-Xiong; Liu, Juncheng; Yu, Ping; Fu, Yun-Qiao; Li, Xu; Pan, Hui

    2015-11-01

    High purified single-walled carbon nanotubes (SWCNTs) were dispersed in water and transparent conducting films (TCFs) were fabricated by a spray coating. The produced uniform SWCNT-TCFs treated by nitric acid have a relatively low sheet resistance and high transmittance. The current-voltage (I-V) behaviors of the TCFs were measured at room to higher temperature during the heating or cooling process. It was found that the I-V behavior of TCFs strongly dependent on the temperature and applied voltage. The sheet resistance showed semiconductor behavior at low temperature and low voltage, while it showed metallic behavior at high temperature and high voltage.

  17. In-vitro corneal transparency measuring system

    NASA Astrophysics Data System (ADS)

    Ventura, Liliane; da Costa Vieira, Marcelo A.; Isaac, Flavio; Chiaradia, Caio; Faria de Sousa, Sidney J.

    2001-06-01

    A system for measuring the average corneal transparency of preserved corneas has been developed in order to provide a more accurate and standard report of the corneal tissue. The donated cornea transparency is one of the features to be analyzed previously to its indication for the transplant. The small portable system consists of two main parts: the optical and the electronic parts. The optical system consists of a white light, lenses and pin-holes that collimate white light beams that illuminates the cornea in its preservative medium. The light that passes through the cornea is detected by a resistive detector and the average corneal transparency is shown in a display. In order to obtain just the tissue transparency, the electronic circuit was built in a way that there is a baseline input of the preservative medium, previous to the measurement of the corneal transparency. Manipulating the system consists of three steps: (1) Adjusting the zero percentage in the absence of light (at this time the detectors in the dark); (2) Placing the preservative medium in the system and adjusting the 100% value (this is the baseline input); (3) Preserving the cornea and placing it in the system. The system provides the tissue transparency. The system is connected to an endothelium evaluation system for Slit Lamp, that we have developed, and statistics about the relationship of the corneal transparency and density of the endothelial cells will be provided in the next years. The system is being used in a public Eye Bank in Brasil.

  18. Solar: A Clean Energy Source for Utilities (Fact Sheet)

    SciTech Connect

    Not Available

    2010-09-01

    The fact sheet summarizes the goals and activities of the DOE Solar Energy Technologies Program efforts with utilities to remove the technical, regulatory, and market challenges they face in deploying solar technologies.

  19. Strengthening America's Energy Security with Offshore Wind (Fact Sheet)

    SciTech Connect

    Not Available

    2012-02-01

    This fact sheet describes the current state of the offshore wind industry in the United States and the offshore wind research and development activities conducted the U.S. Department of Energy Wind and Water Power Program.

  20. Solar America Cities Awards: Solar America Initiative Fact Sheet

    SciTech Connect

    Not Available

    2008-03-01

    This fact sheet provides an overview of the Solar America Cities activities within the Solar America Initiative and lists the 25 cities that have received financial awards from the U.S. Department of Energy.

  1. Highly transparent, low-haze, hybrid cellulose nanopaper as electrodes for flexible electronics

    NASA Astrophysics Data System (ADS)

    Xu, Xuezhu; Zhou, Jian; Jiang, Long; Lubineau, Gilles; Ng, Tienkhee; Ooi, Boon S.; Liao, Hsien-Yu; Shen, Chao; Chen, Long; Zhu, J. Y.

    2016-06-01

    Paper is an excellent candidate to replace plastics as a substrate for flexible electronics due to its low cost, renewability and flexibility. Cellulose nanopaper (CNP), a new type of paper made of nanosized cellulose fibers, is a promising substrate material for transparent and flexible electrodes due to its potentially high transparency and high mechanical strength. Although CNP substrates can achieve high transparency, they are still characterized by high diffuse transmittance and small direct transmittance, resulting in high optical haze of the substrates. In this study, we proposed a simple methodology for large-scale production of high-transparency, low-haze CNP comprising both long cellulose nanofibrils (CNFs) and short cellulose nanocrystals (CNCs). By varying the CNC/CNF ratio in the hybrid CNP, we could tailor its total transmittance, direct transmittance and diffuse transmittance. By increasing the CNC content, the optical haze of the hybrid CNP could be decreased and its transparency could be increased. The direct transmittance and optical haze of the CNP were 75.1% and 10.0%, respectively, greatly improved from the values of previously reported CNP (31.1% and 62.0%, respectively). Transparent, flexible electrodes were fabricated by coating the hybrid CNP with silver nanowires (AgNWs). The electrodes showed a low sheet resistance (minimum 1.2 Ω sq-1) and a high total transmittance (maximum of 82.5%). The electrodes were used to make a light emitting diode (LED) assembly to demonstrate their potential use in flexible displays.Paper is an excellent candidate to replace plastics as a substrate for flexible electronics due to its low cost, renewability and flexibility. Cellulose nanopaper (CNP), a new type of paper made of nanosized cellulose fibers, is a promising substrate material for transparent and flexible electrodes due to its potentially high transparency and high mechanical strength. Although CNP substrates can achieve high transparency, they are

  2. Demonstration of transparent solar array module design

    NASA Technical Reports Server (NTRS)

    Pack, G. J.

    1984-01-01

    This report discusses the design, development, fabrication and testing of IR transparent solar array modules. Three modules, consisting of a baseline design using back surface reflector cells, and two modules using gridded back contact, IR transparent cells, were subjected to vacuum thermal balance testing to verify analytical predictions of lower operating emperature and increased efficiency. As a result of this test program, LMSC has verified that a significant degree of IR transparency can be designed into a flexible solar array. Test data correlates with both steady state and transient thermal analysis.

  3. Flexible and transparent graphene-based loudspeakers

    NASA Astrophysics Data System (ADS)

    Xu, S. C.; Man, B. Y.; Jiang, S. Z.; Chen, C. S.; Yang, C.; Liu, M.; Gao, X. G.; Sun, Z. C.; Zhang, C.

    2013-04-01

    Flexible and transparent graphene films have been fabricated via chemical vapor deposition method, and an extremely thin and lightweight loudspeaker was obtained by transferring the graphene films on both side of the polyvinylidene fluoride film. Once fed by sound frequency electric field, the graphene-based acoustic actuator could emit loud sounds in a wide frequency range. Such film loudspeakers are transparent, flexible, magnet-free and can be tailored into any shape and size, which have wide potential applications in fabricating new type of transparent and flexible devices.

  4. The thermographic nondestructive evaluation of iron aluminide green sheet

    NASA Astrophysics Data System (ADS)

    Watkins, Michael Lee

    The recent development of manufacturing techniques for the fabrication of thin iron aluminide sheet requires advanced quantitative methods for on-line inspection. An understanding of the mechanisms responsible for flaws and the development of appropriate flaw detection methods are key elements in an effective quality management system. The first step in the fabrication of thin FeAl alloy sheet is the formation of a green sheet by cold rolling FeAl powder mixed with organic binding agents. The green sheet composite has a bulk density, which is typically less than about 3.6 g/cc. The finished sheet, with a density of about 6.1 g/cc, is obtained using a series of process steps involving binder elimination, densification, sintering, and annealing. Non-uniformities within the green sheet are the major contributor to material failure in subsequent sheet processing and the production of non-conforming finished sheet. The production environment and physical characteristics of the composite provide for unique challenges in developing a rapid nondestructive inspection capability. The method must be non-contact due to the fragile nature of the composite. Limited access to the material also demands a one-sided inspection technique. An active thermographic method providing for 100% on-line inspection within an industrial, process has been developed. This approach is cost competitive with alternative technologies, such as x-ray imaging systems, and provides the required sensitivity to the variations in material composition. The mechanism of flaw formation and the transformation of green sheet flaws into defects that appear in intermediate and finished sheet products are described. A mathematical model which describes the green sheet heat transfer propagation, in the context of the inspection technique and the compact heterogeneity, is also presented. The potential for feedback within the production process is also discussed.

  5. MESSENGER Observations of Asymmetries at Mercury's Magnetotail Current Sheet

    NASA Astrophysics Data System (ADS)

    Poh, Gangkai; Slavin, James; Jia, Xianzhe; Raines, Jim; Sun, Wei-Jie; Genestreti, Kevin; Smith, Andy; Gershman, Daniel; Anderson, Brian

    2016-04-01

    Dawn-dusk asymmetries in the Earth's magnetotail current sheet have been observed and remain an active area of research. With an internal magnetic dipole field structure similar to Earth's, similar dawn-dusk asymmetries might be expected in Mercury's magnetotail current sheet. However, no observation of dawn-dusk asymmetries has been reported in the structure of Mercury's magnetotail. Using 4 years of MESSENGER's magnetic field and plasma data, we analyzed 319 current sheet crossings. From the polarity of Bz in the cross-tail current sheet, we determined that MESSENGER is on closed field lines about 90% of the time. During the other 10% MESSENGER observed negative Bz indicating that it was tailward of the Near Mercury Neutral Line (NMNL). The Bz magnetic field is also observed to be higher at the dawnside than the duskside of the magnetotail current sheet by approximately a factor of three. Further the asymmetry decreases with increasing downstream distance. A reduction (enhancement) in Bz should correspond to a more (less) stretched and thinned (thickened) current sheet. Analysis of current sheet thickness based upon MESSENGER's observations confirms this behavior with mean current sheet thickness and Bz intensity having dawn-dusk asymmetries with the same sense. Plasma β in the current sheet also exhibits a dawn-dusk asymmetry opposite to that of Bz. This is consistent with expectations based on MHD stress balance. Earlier studies had shown a dawn-dusk asymmetry in the heavy ion in Mercury's magnetotail. We suggest that this enhancement of heavy ions in the duskside current sheet, due to centrifugal acceleration of ions from the cusp and gradient-curvature drift from the NMNL, may provide a partial explanation of the dawn-dusk current sheet asymmetries found in this study.

  6. Concentrating Solar Power Fact Sheet

    SciTech Connect

    2015-12-01

    This fact sheet is an overview of the Concentrating Solar Power (CSP) subprogram at the U.S. Department of Energy SunShot Initiative. CSP is a dispatchable, renewable energy option that uses mirrors to focus and concentrate sunlight onto a receiver, from which a heat transfer fluid carries the intense thermal energy to a power block to generate electricity. CSP systems can store solar energy to be used when the sun is not shining. It will help meet the nation’s goal of making solar energy fully cost-competitive with other energy sources by the end of the decade. Worldwide, CSP activity is rapidly scaling, with approximately 10 gigawatts (GW) in various stages of operation or development. In the United States alone, nearly 2 GW of CSP are in operation.

  7. Ice sheets play important role in climate change

    NASA Astrophysics Data System (ADS)

    Clark, Peter U.; MacAyeal, Douglas R.; Andrews, John T.; Bartlein, Patrick J.

    Ice sheets once were viewed as passive elements in the climate system enslaved to orbitally generated variations in solar radiation. Today, modeling results and new geologic records suggest that ice sheets actively participated in late-Pleistocene climate change, amplifying or driving significant variability at millennial as well as orbital timescales. Although large changes in global ice volume were ultimately caused by orbital variations (the Milankovitch hypothesis), once in existence, the former ice sheets behaved dynamically and strongly influenced regional and perhaps even global climate by altering atmospheric and oceanic circulation and temperature.Experiments with General Circulation Models (GCMs) yielded the first inklings of ice sheets' climatic significance. Manabe and Broccoli [1985], for example, found that the topographic and albedo effects of ice sheets alone explain much of the Northern Hemisphere cooling identified in paleoclimatic records of the last glacial maximum (˜21 ka).

  8. Synthesis of Graphene Films by Chemical Vapor Deposition for Transparent Conducting Electrodes of GaN Light-Emitting Diodes

    NASA Astrophysics Data System (ADS)

    Jo, Gunho; Choe, Minhyeok; Cho, Chu-Young; Kim, Jin Ho; Park, Woojin; Lee, Sangchul; Park, Seong-Ju; Hong, Byung Hee; Kahng, Yung Ho; Lee, Takhee

    2011-12-01

    This work demonstrales large-scale simultaneous fabrication of patterned graphene-based GaN light-emitting diodes (LEDs). Graphene sheets were synthesized using a chemical vapor deposition (CVD) technique on nickel films and showed typical CVD-synthesized film properties, possessing a sheet resistance of ˜605 Ω/⃞ with a transparency of more than 85% in the 400-800 nm wavelength range, and was applied as transparent condueting electrodes of GaN-based blue LHDs, The light output performance of GaN LEDs with graphene electrodes was comparable to that of conventional ITO-electrode LEDs over the range of input current up to 150 mA.

  9. Synergistically enhanced stability of highly flexible silver nanowire/carbon nanotube hybrid transparent electrodes by plasmonic welding.

    PubMed

    Lee, Jongsoo; Woo, Ju Yeon; Kim, Ju Tae; Lee, Byung Yang; Han, Chang-Soo

    2014-07-23

    Here, we report highly transparent and flexible AgNW/SWCNT hybrid networks on PET substrates combined with plasmonic welding for securing ultrahigh stability in mechanical and electrical properties under severe bending. Plasmonic welding produces local heating and welding at the junction of AgNWs and leads strong adhesion between AgNW and SWCNT as well as between hybrid structure and substrate. The initial sheet resistance of plasmon treated AgNW/SWCNT hybrid film was 26 Ω sq(-1), with >90% optical transmittance over the wavelength range 400-2700 nm. Following 200 cycles of convex/concave bending with a bending radius of 5 mm, the sheet resistance changed from 26 to 29 Ω sq(-1). This hybrid structure combined with the plasmonic welding process provided excellent stability, low resistance, and high transparency, and is suitable for highly flexible electronics applications, including touch panels, solar cells, and OLEDs. PMID:24972024

  10. Zinc Oxide-Containing Porous Boron-Carbon-Nitrogen Sheets from Glycine-Nitrate Combustion: Synthesis, Self-Cleaning, and Sunlight-Driven Photocatalytic Activity.

    PubMed

    Bharathidasan, T; Mandalam, Aditya; Balasubramanian, M; Dhandapani, P; Sathiyanarayanan, S; Mayavan, Sundar

    2015-08-26

    We developed a single-step thermal method that enables successful inclusion of ZnO components in the porous boron-carbon-nitrogen (BCN) framework to form a new class of functional hybrid. ZnO-containing BCN hybrids were prepared by treating a mixture of B2O3, glycine, and zinc nitrate at 500 °C. Glycine-nitrate decomposition along with B2O3 acts as a source for ZnO-BCN formation. The incorporation of ZnO onto BCN has extended the photoresponse of ZnO in the visible region, which makes ZnO-BCN a preferable photocatalyst relative to ZnO upon sunlight exposure. It is interesting to note that as-prepared 2D ZnO-BCN sheets dispersed in PDMS form a stable coating over aluminum alloys. The surface exhibited a water contact angle (CA) of 157.6° with 66.6 wt % ZnO-BCN in polydimethylsiloxane (PDMS) and a water droplet (7 μL) roll-off angle of <6° and also demonstrates oil fouling resistant superhydrophobicity. In brief, the present study focuses on the gram scale synthesis of a new class of sunlight-driven photocatalyst and also its application toward the development of superhydrophobic and oleophobic coating. PMID:26252873

  11. Interfacial Assembly of Graphene Oxide Sheets

    NASA Astrophysics Data System (ADS)

    Cote, Laura J.

    Scientific interest in graphene oxide (GO) sheets, the product of chemical oxidation and exfoliation of graphite powder, has resurged in recent years because GO is considered a promising precursor for the bulk production of graphene-based sheets for a variety of applications. In addition, GO can be viewed as an unconventional type of soft material as it is characterized by two abruptly different length scales. Its thickness is of typical molecular dimensions, measured to be about 1 nm by atomic force microscopy, but its lateral dimensions are that of common colloidal particles, ranging from nanometers to tens of microns. This high anisotropy leads to interesting fundamental colloidal interactions between the soft sheets which have practical implications in the solution processing and assembly of the material. This research therefore aims to use a variety of techniques to control these inter-sheet interactions to gain an understanding of the processing-structure relationships which ultimately determine the overall properties of the bulk GO assembly. GO is identified as a two-dimensional amphiphile with a unique edge-to-center arrangement of hydrophilic and hydrophobic groups, which has led to the demonstration of its pH- and size-dependent surface activity. The water surface is then utilized, as in the Langmuir-Blodgett technique, as an ideal substrate to tile up the GO sheets and study the interactions between them. Sheet-sheet interaction morphologies were successfully altered between wrinkled and overlapped states by pH tuning of sheet charge density, and the resulting structure-property relationships are explored. In addition, a novel flash-reduction and assembly process is described in which a simple photographic camera flash can rapidly and cleanly turn an insulating, well-stacked GO paper to a more open and fluffy conducting film. Lastly, the use of these research results as educational outreach platforms is highlighted. A variety of outlets, such as You

  12. Synthesis, characterization, electronic and gas-sensing properties towards H2 and CO of transparent, large-area, low-layer graphene.

    PubMed

    Kayhan, Emine; Prasad, Ravi Mohan; Gurlo, Alexander; Yilmazoglu, Oktay; Engstler, Jörg; Ionescu, Emanuel; Yoon, Songhak; Weidenkaff, Anke; Schneider, Jörg J

    2012-11-19

    Low-layered, transparent graphene is accessible by a chemical vapor deposition (CVD) technique on a Ni-catalyst layer, which is deposited on a <100> silicon substrate. The number of graphene layers on the substrate is controlled by the grain boundaries in the Ni-catalyst layer and can be studied by micro Raman analysis. Electrical studies showed a sheet resistance (R(sheet)) of approximately 1435 Ω per □, a contact resistance (R(c)) of about 127 Ω, and a specific contact resistance (R(sc)) of approximately 2.8×10(-4)  Ω cm(2) for the CVD graphene samples. Transistor output characteristics for the graphene sample demonstrated linear current/voltage behavior. A current versus voltage (I(ds)-V(ds)) plot clearly indicates a p-conducting characteristic of the synthesized graphene. Gas-sensor measurements revealed a high sensor activity of the low-layer graphene material towards H(2) and CO. At 300 °C, a sensor response of approximately 29 towards low H(2) concentrations (1 vol %) was observed, which is by a factor of four higher than recently reported. PMID:23032996

  13. Coloured Rings Produced on Transparent Plates

    ERIC Educational Resources Information Center

    Suhr, Wilfried; Schlichting, H. Joachim

    2007-01-01

    Beautiful colored interference rings can be produced by using transparent plates such as window glass. A simple model explains this effect, which was described by Newton but has almost been forgotten. (Contains 11 figures.)

  14. Induced Transparency and Absorption in Coupled Microresonators

    NASA Technical Reports Server (NTRS)

    Smith, David D.; Chang, Hongrok

    2004-01-01

    We review the conditions for the occurrence of coherence phenomena in passive coupled optical microresonators. We derive the effective steady-state response and determine conditions for induced transparency and absorption in these systems.

  15. Transparency Film for Demonstration of Biaxial Optics.

    ERIC Educational Resources Information Center

    Camp, Paul R.

    1994-01-01

    Explains why transparency film demonstrates biaxial optical properties. Provides detailed descriptions of the procedure and equipment needed for large-scale optics demonstrations of the polarization interference pattern produced by biaxial crystals. (DDR)

  16. p-type transparent conducting oxides

    NASA Astrophysics Data System (ADS)

    Sheng, Su; Fang, Guojia; Li, Chun; Xu, Sheng; Zhao, Xingzhong

    2006-06-01

    The recent advance of p-type transparent conductive oxide thin films is reviewed. The focus is on p-type transparent oxide semiconductors CuAlO2, CuGaO2, CuInO2, SrCu2O2, and LaCuOCh (Ch = chalcogen). These materials and related device applications are then shown as examples. Room temperature operation of current injection emission from ultraviolet light-emitting diodes based on p-SCO/n-ZnO p-n junctions has been demonstrated. This changed with the discovery of p-type transparent conducting oxides, thereby opening up the possibility for all-oxide transparent electronics.

  17. Transparency--"Deal or no deal"?

    PubMed

    Lutz, Sandy

    2007-01-01

    In the United States, transparency is becoming an ideal worthy of Mom and apple pie, like quality in healthcare. Physicians, payers, hospitals, business associations, and organizations representing patients have all chimed in expressing support. At the local, state, and national levels a variety of transparency initiatives are under way. How will transparency affect the healthcare industry? Transparency could profoundly change today's balance of power, for it is about information, and information is power. As employers push more cost sharing to workers, hospitals and health systems will have to construct a pricing structure that is meaningful to consumers. What are providers to do? To be successful with this new demand, providers should make sure they are making quality information as well as pricing information available to consumers. They will have to know the market, know what their own prices mean, consider the customer, and reengineer business processes around the patient rather than around the billing side of business. PMID:17405388

  18. Transparent Soil for Imaging the Rhizosphere

    PubMed Central

    Downie, Helen; Holden, Nicola; Otten, Wilfred; Spiers, Andrew J.; Valentine, Tracy A.; Dupuy, Lionel X.

    2012-01-01

    Understanding of soil processes is essential for addressing the global issues of food security, disease transmission and climate change. However, techniques for observing soil biology are lacking. We present a heterogeneous, porous, transparent substrate for in situ 3D imaging of living plants and root-associated microorganisms using particles of the transparent polymer, Nafion, and a solution with matching optical properties. Minerals and fluorescent dyes were adsorbed onto the Nafion particles for nutrient supply and imaging of pore size and geometry. Plant growth in transparent soil was similar to that in soil. We imaged colonization of lettuce roots by the human bacterial pathogen Escherichia coli O157:H7 showing micro-colony development. Micro-colonies may contribute to bacterial survival in soil. Transparent soil has applications in root biology, crop genetics and soil microbiology. PMID:22984484

  19. Highly transparent Nb-doped indium oxide electrodes for organic solar cells

    SciTech Connect

    Kim, Jun Ho; Seong, Tae-Yeon; Na, Seok-In; Chung, Kwun-Bum; Lee, Hye-Min; Kim, Han-Ki

    2014-03-15

    The authors investigated the characteristics of Nb-doped In{sub 2}O{sub 3} (INbO) films prepared by co-sputtering of Nb{sub 2}O{sub 5} and In{sub 2}O{sub 3} for use in transparent anodes for organic solar cells (OSCs). To optimize the Nb dopant composition in the In{sub 2}O{sub 3} matrix, the effect of the Nb doping power on the resistivity and transparency of the INbO films were examined. The electronic structure and microstructure of the INbO films were also investigated using synchrotron x-ray absorption spectroscopy and x-ray diffraction examinations in detail. At the optimized Nb co-sputtering power of 30 W, the INbO film exhibited a sheet resistance of 15 Ω/sq, and an optical transmittance of 86.04% at 550 nm, which are highly acceptable for the use as transparent electrodes in the fabrication of OSCs. More importantly, the comparable power conversion efficiency (3.34%) of the OSC with an INbO anode with that (3.31%) of an OSC with a commercial ITO anode indicates that INbO films are promising as a transparent electrode for high performance OSCs.

  20. Fully solution-processed transparent electrodes based on silver nanowire composites for perovskite solar cells.

    PubMed

    Kim, Areum; Lee, Hongseuk; Kwon, Hyeok-Chan; Jung, Hyun Suk; Park, Nam-Gyu; Jeong, Sunho; Moon, Jooho

    2016-03-28

    We report all-solution-processed transparent conductive electrodes based on Ag nanowire (AgNW)-embedded metal oxide composite films for application in organometal halide perovskite solar cells. To address the thermal instability of Ag nanowires, we used combustive sol-gel derived thin films to construct ZnO/ITO/AgNW/ITO composite structures. The resulting composite configuration effectively prevented the AgNWs from undergoing undesirable side-reactions with halogen ions present in the perovskite precursor solutions that significantly deteriorate the optoelectrical properties of Ag nanowires in transparent conductive films. AgNW-based composite electrodes had a transmittance of ∼80% at 550 nm and sheet resistance of 18 Ω sq(-1). Perovskite solar cells fabricated using a fully solution-processed transparent conductive electrode, Au/spiro-OMeTAD/CH3NH3PbI3 + m-Al2O3/ZnO/ITO/AgNW/ITO, exhibited a power conversion efficiency of 8.44% (comparable to that of the FTO/glass-based counterpart at 10.81%) and were stable for 30 days in ambient air. Our results demonstrate the feasibility of using AgNWs as a transparent bottom electrode in perovskite solar cells produced by a fully printable process. PMID:26465213

  1. Direct synthesis of graphene 3D-coated Cu nanosilks network for antioxidant transparent conducting electrode.

    PubMed

    Xu, Hongmei; Wang, Huachun; Wu, Chenping; Lin, Na; Soomro, Abdul Majid; Guo, Huizhang; Liu, Chuan; Yang, Xiaodong; Wu, Yaping; Cai, Duanjun; Kang, JunYong

    2015-06-28

    Transparent conducting film occupies an important position in various optoelectronic devices. To replace the costly tin-doped indium oxide (ITO), promising materials, such as metal nanowires and graphene, have been widely studied. Moreover, a long-pursued goal is to consolidate these two materials together and express their outstanding properties simultaneously. We successfully achieved a direct 3D coating of a graphene layer on an interlacing Cu nanosilks network by the low pressure chemical vapor deposition method. High aspect ratio Cu nanosilks (13 nm diameter with 40 μm length) were synthesized through the nickel ion catalytic process. Large-size, transparent conducting film was successfully fabricated with Cu nanosilks ink by the imprint method. A magnetic manipulator equipped with a copper capsule was used to produce high Cu vapor pressure on Cu nanosilks and realize the graphene 3D-coating. The coated Cu@graphene nanosilks network achieved high transparency, low sheet resistance (41 Ohm sq(-1) at 95% transmittance) and robust antioxidant ability. With this technique, the transfer process of graphene is no longer needed, and a flexible, uniform and high-performance transparent conducting film could be fabricated in unlimited size. PMID:26018299

  2. Flexible, Highly Durable, and Thermally Stable SWCNT/Polyimide Transparent Electrodes.

    PubMed

    Kim, Seong-Ku; Liu, Tao; Wang, Xiaogong

    2015-09-23

    Flexible, transparent, and electrically conducting electrode materials are highly desired for flexible electronic applications. With a highly transparent polyimide (PI) as a substrate, a comprehensive and comparative study was performed to investigate four different fabrication schemes in producing transparent and electrically conducting SWCNT/PI electrodes. A very promising method that involves an in situ imidization process and nitric acid doping treatment was identified, which led to the fabrication of highly durable and thermally stable SWCNT/PI electrodes. The best performed electrode has a transmission of 77.6% at 550 nm and a sheet resistance (Rs) of 1169 ± 172 Ω/□, which appeared no changes after repeating tests of bending, folding-unfolding, adhesive-tape-peeling-off, and wet tissue-paper scratching/wiping. The excellent thermal stability of such fabricated SWCNT/PI electrode is manifested by the very high glass transition temperature of 290.1 °C and low coefficient of thermal expansion (CTE) of 28.5 ppm °C(-1) in the temperature range from 75 to 200 °C. The new method expects to be able to pave the way in facile production of high-performance flexible, transparent, and conducting electrodes. PMID:26323087

  3. Transparency in nursing leadership: a chosen ethic.

    PubMed

    Milton, Constance L

    2009-01-01

    The concept of transparency has been viewed as an essential leadership attribute or element in healthcare organizational structures and processes. While viewed as something that is desired and valued, there is a lack of nursing disciplinary literature that defines the concept and its possible meanings. This column provides a beginning definition of transparency from the humanbecoming nursing theoretical perspective and launches a discussion with potential ethical implications for leadership in nursing practice and education. PMID:19176856

  4. High quality transparent conducting oxide thin films

    DOEpatents

    Gessert, Timothy A.; Duenow, Joel N.; Barnes, Teresa; Coutts, Timothy J.

    2012-08-28

    A transparent conducting oxide (TCO) film comprising: a TCO layer, and dopants selected from the elements consisting of Vanadium, Molybdenum, Tantalum, Niobium, Antimony, Titanium, Zirconium, and Hafnium, wherein the elements are n-type dopants; and wherein the transparent conducting oxide is characterized by an improved electron mobility of about 42 cm.sup.2/V-sec while simultaneously maintaining a high carrier density of .about.4.4e.times.10.sup.20 cm.sup.-3.

  5. Transparent conducting oxides and production thereof

    DOEpatents

    Gessert, Timothy A; Yoshida, Yuki; Coutts, Timothy J

    2014-05-27

    Transparent conducting oxides and production thereof are disclosed. An exemplary method of producing a transparent conducting oxide (TCO) material may comprise: providing a TCO target (110) doped with either a high-permittivity oxide or a low-permittivity oxide in a process chamber (100). The method may also comprise depositing a metal oxide on the target (110) to form a thin film having enhanced optical properties without substantially decreasing electrical quality.

  6. Transparent conducting oxides and production thereof

    DOEpatents

    Gessert, Timothy A.; Yoshida, Yuki; Coutts, Timothy J.

    2014-06-10

    Transparent conducting oxides and production thereof are disclosed. An exemplary method of producing a transparent conducting oxide (TCO) material may comprise: providing a TCO target doped with either a high-permittivity oxide or a low-permittivity oxide in a process chamber. The method may also comprise depositing a metal oxide on the target in the process chamber to form a thin film having enhanced optical properties without substantially decreasing electrical quality.

  7. Transparent conductive reduced graphene oxide thin films produced by spray coating

    NASA Astrophysics Data System (ADS)

    Shi, HongFei; Wang, Can; Sun, ZhiPei; Zhou, YueLiang; Jin, KuiJuan; Yang, GuoZhen

    2015-01-01

    Reduced graphene oxide thin films were fabricated on quartz by spray coating method using a stable dispersion of reduced graphene oxide in N,N-Dimethylformamide. The dispersion was produced by chemical reduction of graphene oxide, and the film thickness was controlled with the amount of spray volume. AFM measurements revealed that the thin films have near-atomically flat surface. The chemical and structural parameters of the samples were analyzed by Raman and XPS studies. It was found that the thin films show electrical conductivity with good optical transparency in the visible to near infrared region. The sheet resistance of the films can be significantly reduced by annealing in vacuum and reach 58 kΩ with a light transmittance of 68.69% at 550 nm. The conductive transparent properties of the reduced graphene oxide thin films would be useful to develop flexible electronics.

  8. A stably enhanced transparent conductive graphene film obtained using an air-annealing method

    NASA Astrophysics Data System (ADS)

    Song, Xuefen; Wei, Dapeng; Sun, Tai; Yu, Leyong; Yang, Jun; Zhang, Yongna; Fang, Liang; Wei, Dacheng; Shi, Haofei; Du, Chunlei

    2016-08-01

    A simple and effective air-annealing technique was developed to stably improve both the electrical conductivity and light transmission of pristine graphene. After the graphene film was annealed in air at 250 °C for 80 min, the mobility and carrier concentration were both significantly enhanced, and the sheet resistance was greatly reduced with a decrease rate of ∼33%. Meanwhile, the transparency was also improved by more than 3%. The mechanism is carefully discussed. The reason might be that air-annealing conditions provide a suitable atmosphere to etch and remove amorphous carbons. More importantly, the enhanced transparent conductive properties of the air-annealed graphene films were extraordinarily stable, and remained almost unchanged for 100 days.

  9. Solution-Processed Copper/Reduced-Graphene-Oxide Core/Shell Nanowire Transparent Conductors.

    PubMed

    Dou, Letian; Cui, Fan; Yu, Yi; Khanarian, Garo; Eaton, Samuel W; Yang, Qin; Resasco, Joaquin; Schildknecht, Christian; Schierle-Arndt, Kerstin; Yang, Peidong

    2016-02-23

    Copper nanowire (Cu NW) based transparent conductors are promising candidates to replace ITO (indium-tin-oxide) owing to the high electrical conductivity and low-cost of copper. However, the relatively low performance and poor stability of Cu NWs under ambient conditions limit the practical application of these devices. Here, we report a solution-based approach to wrap graphene oxide (GO) nanosheets on the surface of ultrathin copper nanowires. By mild thermal annealing, GO can be reduced and high quality Cu r-GO core-shell NWs can be obtained. High performance transparent conducting films were fabricated with these ultrathin core-shell nanowires and excellent optical and electric performance was achieved. The core-shell NW structure enables the production of highly stable conducting films (over 200 days stored in air), which have comparable performance to ITO and silver NW thin films (sheet resistance ∼28 Ω/sq, haze ∼2% at transmittance of ∼90%). PMID:26820809

  10. Manipulation of electromagnetically induced transparency by planar metamaterial

    NASA Astrophysics Data System (ADS)

    Yang, Helin; Hu, Sen; Liu, Dan; Lin, Hai; Xiao, Boxun; Chen, Jiao

    2016-02-01

    The transmission characteristics of a planar metamaterial, composed of a metal ring and a regular trigonometry-star-rod (TSR), have been numerically and experimentally investigated in this paper. By rotating the TSR with different angles, this structure will appear to be symmetric or asymmetric toward the incident waves and then finely controls the coupling between the ring and the TSR. Thus, the transmission spectrum of our proposed structure can exhibit an electromagnetically induced transparency (EIT)-like spectral response in microwave region. Owing to the C3 rotational symmetry of the structure, an on-to-off active modulation of the EIT-like transparency window can be realized, and it may serve as the base for a microwave optical switching. Equivalent electric dipole moments couplings are employed to explain the transmission properties. In all, our work provides a way to obtain EIT-like effect, and it may achieve potential applications in filters, sensing and some other microwave devices.

  11. Transparency and Coherence in rf SQUID Metamaterials

    NASA Astrophysics Data System (ADS)

    Anlage, Steven; Trepanier, Melissa; Zhang, Daimeng

    We have developed active metamaterials capable of quickly tuning their electrical and magnetic responses over a wide frequency range. These metamaterials are based on superconducting elements to form low loss, physically and electrically small, highly tunable structures for fundamental studies of extraordinarily nonlinear media. The meta-atoms are rf superconducting quantum interference devices (SQUIDs) that incorporate the Josephson effect. RF SQUIDs have an inductance which is strongly tunable with dc and rf magnetic fields and currents. The rf SQUID metamaterial is a richly nonlinear effective medium introducing qualitatively new macroscopic quantum phenomena into the metamaterials community, namely magnetic flux quantization and the Josephson effect. The coherent oscillation of the meta-atoms is strongly sensitive to the environment and measurement conditions, and we have developed several strategies to improve the coherence experimentally by exploiting ideas from nonlinear dynamics. The metamaterials also display a unique form of transparency whose development can be manipulated through multiple parametric dependences. We discuss these qualitatively new metamaterial phenomena. This work is supported by the NSF-GOALI and OISE Programs through Grant No. ECCS-1158644 and the Center for Nanophysics and Advanced Materials (CNAM).

  12. Dissipative solitons of self-induced transparency

    NASA Astrophysics Data System (ADS)

    Adamashvili, G. T.; Kaup, D. J.; Knorr, A.

    2014-11-01

    A theory of dispersive soliton of the self-induced transparency in a medium consisting of atoms or semiconductor quantum dots of two types is considered. A two-component medium is modeled by a set of two-level atoms of two types embedded into a conductive host material. These types of atoms correspond to passive atoms (attenuator atoms) and active atoms (amplifier atoms) with inverse population of the energetic levels. The complete solution is given of the Maxwell-Bloch equations for ensembles of two-type atoms with different parameters and different initial conditions by inverse scattering transform. The solutions of the Maxwell-Bloch equations for many-component atomic systems by inverse scattering transform are also discussed. The influence of the difference between dipole moments of atoms, the longitudinal and transverse relaxation times, pumping, and conductivity on the soliton is taken into account by means of perturbation theory. The memory effects are described in terms of generalized non-Markovian optical Bloch equations. The condition of a balance between the energy supplied and lost is obtained.

  13. High mobility annealing of Transparent Conductive Oxides

    NASA Astrophysics Data System (ADS)

    Warzecha, M.; Owen, J. I.; Wimmer, M.; Ruske, F.; Hotovy, J.; Hüpkes, J.

    2012-04-01

    To improve electrical properties a high temperature annealing treatment was applied to several transparent conductive oxides (TCO), namely tin doped indium oxide (ITO), Ga- or Al- doped ZnO (ZnO:Al/Ga), ion beam assisted deposited (IBAD) ZnO:Ga and Ga doped zinc magnesium oxide (ZnMgO:Ga). All these films were grown by magnetron sputtering. During the annealing process all TCO films were capped with 50 nm of amorphous silicon in order to protect the films from environmental impact. Increase in mobility up to 72 cm2/Vs and low resistivity of 1.6 × 10-4 Ωcm was achieved for ZnO:Al after annealing at 650°C for 24 h. Independent of the deposition conditions and doping or alloying material almost all ZnO based films show a consistent improvement in mobility. Also for ITO films a decrease in resistivity with partially improved mobility was found after annealing. However, not all ITO films show consistent improvement, but carrier density above 1021 cm-3 while ZnO films show no clear trend for carrier density but a remarkable increase in mobility. Thus we propose the healing of defects and the activation of donors to be most significant effects for ZnO and ITO films, respectively.

  14. Nonvacuum, maskless fabrication of a flexible metal grid transparent conductor by low-temperature selective laser sintering of nanoparticle ink.

    PubMed

    Hong, Sukjoon; Yeo, Junyeob; Kim, Gunho; Kim, Dongkyu; Lee, Habeom; Kwon, Jinhyeong; Lee, Hyungman; Lee, Phillip; Ko, Seung Hwan

    2013-06-25

    We introduce a facile approach to fabricate a metallic grid transparent conductor on a flexible substrate using selective laser sintering of metal nanoparticle ink. The metallic grid transparent conductors with high transmittance (>85%) and low sheet resistance (30 Ω/sq) are readily produced on glass and polymer substrates at large scale without any vacuum or high-temperature environment. Being a maskless direct writing method, the shape and the parameters of the grid can be easily changed by CAD data. The resultant metallic grid also showed a superior stability in terms of adhesion and bending. This transparent conductor is further applied to the touch screen panel, and it is confirmed that the final device operates firmly under continuous mechanical stress. PMID:23731244

  15. Evidence for in-situ metabolic activity in ice sheets based on anomalous trace gas records from the Vostok and other ice cores

    NASA Astrophysics Data System (ADS)

    Sowers, T.

    2003-04-01

    Measurements of trace gas species in ice cores are the primary means for reconstructing the composition of the atmosphere. The longest such record comes from the Vostok core taken from the central portion of the East Antarctic ice sheet [Petit et al., 1999]. In general, the trace gas records from Vostok are utilized as the reference signal when correlating trace gas measurements from other ice cores. The underlying assumption implicit in such endeavors is that the bubbles recovered from the ice cores record the composition of the atmosphere at the time the bubbles were formed. Another implicit assumption is that the composition of the bubbles has not been compromised by the extremely long storage periods within the ice sheet. While there is ample evidence that certain trace gas records (e.g. CO2 and CH4) have probably not been compromised, anomalous nitrous oxide (N2O) measurements from the penultimate glacial termination at Vostok are consistent with in-situ (N2O) production [Sowers, 2001]. In general, trace gas measurements from high altitude tropical/temperate glaciers are higher than expected based on contemporaneous measurements from polar cores. Measurements spanning the last 25kyr from the Sajama ice core from central Bolivia (18oS, 69oW, 6542masl), for example, were 1X-5X higher than contemporaneous values recorded in polar ice cores [Campen et al., 2003]. While other physical factors (like temperature/melting) may contribute to the elevated trace gas levels at these sites, the most likely explanation involves the accumulation of in-situ metabolic trace gas byproducts. Stable isotope measurements provide independent information for assessing the origin of the elevated trace gas levels in select samples. For the penultimate glacial termination at Vostok, the anomalous (N2O) values carry high δ15Nbulk and low δ18Obulk values that would be predicted if the added (N2O) was associated with in-situ nitrification. At Sajama, low δ13CH4 values observed during

  16. Ice sheets and nitrogen

    PubMed Central

    Wolff, Eric W.

    2013-01-01

    Snow and ice play their most important role in the nitrogen cycle as a barrier to land–atmosphere and ocean–atmosphere exchanges that would otherwise occur. The inventory of nitrogen compounds in the polar ice sheets is approximately 260 Tg N, dominated by nitrate in the much larger Antarctic ice sheet. Ice cores help to inform us about the natural variability of the nitrogen cycle at global and regional scale, and about the extent of disturbance in recent decades. Nitrous oxide concentrations have risen about 20 per cent in the last 200 years and are now almost certainly higher than at any time in the last 800 000 years. Nitrate concentrations recorded in Greenland ice rose by a factor of 2–3, particularly between the 1950s and 1980s, reflecting a major change in NOx emissions reaching the background atmosphere. Increases in ice cores drilled at lower latitudes can be used to validate or constrain regional emission inventories. Background ammonium concentrations in Greenland ice show no significant recent trend, although the record is very noisy, being dominated by spikes of input from biomass burning events. Neither nitrate nor ammonium shows significant recent trends in Antarctica, although their natural variations are of biogeochemical and atmospheric chemical interest. Finally, it has been found that photolysis of nitrate in the snowpack leads to significant re-emissions of NOx that can strongly impact the regional atmosphere in snow-covered areas. PMID:23713125

  17. Twisting of sheet metals

    NASA Astrophysics Data System (ADS)

    Pham, C. H.; Thuillier, S.; Manach, P. Y.

    2013-12-01

    Twisting of metallic sheets is one particular mode of springback that occurs after drawing of elongated parts, i.e. with one dimension much larger than the two others. In this study, a dedicated device for drawing of elongated part with a U-shaped section has been designed on purpose, in order to obtain reproducible data. Very thin metallic sheet, of thickness 0.15 mm, has been used, so that the maximum length of the part is 100 mm. Two different orientations of the part with respect to the tools have been chosen: either aligned with the tools, or purposefully misaligned by 2°. Several samples were drawn for each configuration, leading to the conclusion that almost no twisting occurs in the first case whereas a significant one can be measured for the second one. In a second step, 2D and 3D numerical simulations within the implicit framework for drawing and springback were carried out. A mixed hardening law associated to von Mises yield criterion represents accurately the mechanical behavior of the material. This paper highlights a comparison of numerical predictions with experiments, e.g. the final shape of the part and the twisting parameter.

  18. Chemical modification of poly (vinyl chloride) sheet with thiourea for cell study

    NASA Astrophysics Data System (ADS)

    Monika, Mishra, R. R.; Jaiswal, S.; Kapusetti, G.; Misra, N.

    2013-06-01

    Plasticized poly (vinyl chloride) has been used as biomaterial to make medical equipment. An appropriate reaction situation by temperature at 60-85°C for the surface modification of PVC sheet with sodium thiourea has been investigated. Although, the use of a phase-transfer catalyst (Tetra butyl ammonium hydrogen sulphate-TBHAS) makes it feasible for the nucleophilic substitution reaction to take place, the morphology of the film is changed by the reaction, leading to a loss in both surface smoothness and transparency of the film. According to this study, the reaction with sodium thiourea occurs consistently through the sheets, and modified surface have antibacterial capacity.

  19. Graphene: powder, flakes, ribbons, and sheets.

    PubMed

    James, Dustin K; Tour, James M

    2013-10-15

    fibers and in the fabrication of large area transparent electrodes. Using solid carbon sources such as polymers, food, insects, and waste, we can grow monolayer and bilayer graphene directly on metal catalysts, and carbon-sources containing nitrogen can produce nitrogen-doped graphene. The resulting graphene can be transferred to other surfaces, such as metal grids, for potential use in transparent touch screens for applications in personal electronics and large area photovoltaic devices. Because the transfer of graphene from one surface to another can lead to defects, low yields, and higher costs, we have developed methods for growing graphene directly on the substrates of interest. We can also produce patterned graphene to make GNRs or graphane/graphene superlattices within a single sheet. These superlattices could have multiple functions for use in sensors and other devices. This Account only touches upon this burgeoning area of materials chemistry, and the field will continue to expand as researchers imagine new forms and applications of graphene. PMID:23276286

  20. 17. INTAKE PIER, BRIDGE STRESS SHEET, SHEET 8 OF 117, ...

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

    17. INTAKE PIER, BRIDGE STRESS SHEET, SHEET 8 OF 117, 1920. - Sacramento River Water Treatment Plant Intake Pier & Access Bridge, Spanning Sacramento River approximately 175 feet west of eastern levee on river; roughly .5 mile downstream from confluence of Sacramento & American Rivers, Sacramento, Sacramento County, CA

  1. 9. Photograph of sheet 1 (index and title sheet) of ...

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

    9. Photograph of sheet 1 (index and title sheet) of the State Highway Department of Indiana repair plans of 1957 for the Cicott Street Bridge. Photograph of a 24' by 36' print made from microfilm in the archives of the Indiana Department of Transportation in Indianapolis. - Cicott Street Bridge, Spanning Wabash River at State Road 25, Logansport, Cass County, IN

  2. 13. Photograph of sheet 1 (index and title sheet) of ...

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

    13. Photograph of sheet 1 (index and title sheet) of the Indiana State Highway Commission repair plans of 1969 for the Cicott Street Bridge. Photograph of a 24' by 36' print made from microfilm in the archives of the Indiana Department of Transportation in Indianapolis. - Cicott Street Bridge, Spanning Wabash River at State Road 25, Logansport, Cass County, IN

  3. 10. KIDNER BRIDGE STRUCTURAL STEEL DETAIL SHEET (original plan sheet ...

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

    10. KIDNER BRIDGE STRUCTURAL STEEL DETAIL SHEET (original plan sheet is in possession of Ball State University, Drawings and Documents Archive, COllege of Architecture and Planing, Ball State University, Muncie, Indiana, 47306 - Kidner Bridge, Spanning Mississinewa River at County Road 700 South, Upland, Grant County, IN

  4. Mussel-Inspired Polydopamine-Functionalized Graphene as a Conductive Adhesion Promoter and Protective Layer for Silver Nanowire Transparent Electrodes.

    PubMed

    Miao, Jinlei; Liu, Haihui; Li, Wei; Zhang, Xingxiang

    2016-05-31

    For the scalable fabrication of transparent electrodes and optoelectronic devices, excellent adhesion between the conductive films and the substrates is essential. In this work, a novel mussel-inspired polydopamine-functionalized graphene/silver nanowire hybrid nanomaterial for transparent electrodes was fabricated in a facile manner. Graphene oxide (GO) was functionalized and reduced by polydopamine while remaining stable in water without precipitation. It is shown that the polydopamine-functionalized GO (PFGO) film adhered to the substrate much more easily and more uniformly than the GO film. The PFGO film had a sheet resistance of ∼3.46 × 10(8) Ω/sq and a transparency of 78.2%, with excellent thermal and chemical stability; these characteristics are appropriate for antistatic coatings. Further reduced PFGO (RPFGO) as a conductive adhesion promoter and protective layer for the Ag nanowire (AgNW) significantly enhanced the adhesion force between AgNW networks and the substrate. The RPFGO-AgNW electrode was found to have a sheet resistance of 63 Ω/sq and a transparency of 70.5%. Moreover, the long-term stability of the RPFGO-AgNW electrode was greatly enhanced via the effective protection of the AgNW by RPFGO. These solution-processed antistatic coatings and electrodes have tremendous potential in the applications of optoelectronic devices as a result of their low production cost and facile processing. PMID:27142815

  5. Fiche pratique: Choisir sa voix; Faites des transparents; Preparer un voyage d'entreprise; Radio reporter (Practical Ideas: Choosing a Voice; Make Transparencies; Preparing a Tour; Radio Reporting).

    ERIC Educational Resources Information Center

    Francais dans le Monde, 1993

    1993-01-01

    Four ideas for classroom French language instruction are described, including an exercise in selection of passive and active voice, a project in which students prepare transparencies for an oral presentation, an activity in which Italian students develop a tour for French visitors, and a radio broadcast project. (MSE)

  6. 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.

  7. 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.

  8. HEU Transparency Implementation Program and its Radiation Safety Program

    SciTech Connect

    Radev, R

    2002-01-31

    of the agreement are met. The Highly Enriched Uranium (HEU) Transparency Implementation Program (TIP), within NNSA implements the transparency provisions of the bilateral agreement. It is constantly making progress towards meeting its objectives and gathering the information necessary to confirm that Russian weapons-usable HEU is being blended into LEU. Since the first shipment in 1995 through December 2001, a total of 141 MT of weapons-grade HEU, about 28% of the agreed total and equivalent to 5,650 nuclear weapons, was converted to LEU, further reducing the threat of this material returning back into nuclear weapons. In the year 2001, the LEU sold to electric utility customers for fuel was sufficient to supply the annual fuel needs for about 50 percent of the U.S. installed nuclear electrical power generation capacity. There are four primary uranium processing activities involved in converting HEU metal components extracted from dismantled nuclear weapons into fuel for power reactors: (1) Converting HEU metal to purified HEU oxide; (2) Converting purified HEU oxide to HEU hexafluoride; (3) Downblending HEU hexafluoride to LEU hexafluoride; and (4) Converting LEU hexafluoride into reactor fuel. The first three processes are currently being performed at four Russian nuclear processing facilities: Mayak Production Association (MPA), Electrochemical Plant (ECP), Siberian Chemical Enterprise (SChE), and Ural Electrochemical Integrated Plant (UEIP). Following the blending down of HEU, the LEU hexafluoride is loaded into industry, standard 30B cylinders at the downblending facilities and transported to St. Petersburg, Russia. From there the LEU is shipped by sea to the United States where it is converted into fuel to be used in nuclear power plants. There are six U.S. facilities processing LEU subject to the HEU purchase agreement: the Portsmouth uranium enrichment plant, Global Nuclear Fuel -America, Framatome-Lynchburg, Framatome-Richland, Westinghouse-Hematite, and

  9. Chronologic evidence for multiple periods of loess deposition during the Late Pleistocene in the Missouri and Mississippi River Valley, United States: Implications for the activity of the Laurentide ice sheet

    USGS Publications Warehouse

    Forman, S.L.; Bettis, E. Arthur, III; Kemmis, T.J.; Miller, B.B.

    1992-01-01

    The loess stratigraphy of the mid-continental U.S. is an important proxy record for the activity of the Laurentide Ice Sheet in North America. One of the most outstanding problems is deciphering the age of loess deposits in this area during the late Pleistocene. Radiocarbon dating of snails and thermoluminescence dating of the fine-silt fraction (4-11 ??m) from loess at the Loveland Loess type section, Loveland, Iowa and a recent excavation at the Pleasant Grove School section. Madison County, Illinois provide new chronologic control on loess deposition in the Mississippi/Missouri River Valley chronology indicates that the Loveland Loess is Illinoian in age (135??20 ka) but is not correlative with the Teneriffe Silt which is dated to 77 ?? 8 ka. Concordant radiocarbon and thermoluminescence age estimates demonstrate that the Roxana Silt and a correlative loess in Iowa, the Pisgah Formation, is probably 40-30 ka old. These age estimates in conjunction with previous results indicate that there were four periods of loess deposition during the last 150 ka at 25-12 ka, 45-30 ka, 85-70 ka and at ca. 135 ?? 20 ka. This chronology of loess deposition supports the presence of both a late Illinoian and early Wisconsinan loess and associated soils. Thus, there may be more than one soil in the loess stratigraphy of the mid-continental U.S. with morphologies similar to the Sangamon Soil. The last three periods of loess deposition may be correlative with periods of elevated dust concentrations recorded in the Dye 3 ice core from southern Greenland. This is particularly significant because both areas possibly had the same source for eolian particles. Reconstructions of atmospheric circulation for glacial periods show a southerly deflected jet stream that could have transported dust from the mid-continental USA to southern Greenland. Lastly, the inferred record of loess deposition is parallel to a chronology for deglaciation of the Laurentide Ice Sheet deciphered from chronologic

  10. Transparent conductive thin-film encapsulation layers (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Behrendt, Andreas; Gahlmann, Tobias; Trost, Sara; Polywka, Andreas; Görrn, Patrick; Riedl, Thomas

    2015-10-01

    Gas diffusion barriers (GDB) are inevitable to protect sensitive organic materials or devices against ambient gases. Typically, thin-film gas diffusion barriers are insulators, e.g. Al2O3 or multilayers of Al2O3/ZrO2, etc.. A wide range of applications would require GDB which are at the same time transparent and electrically conductive. They could serve as electrode and moisture barrier simultaneously, thereby simplifying production. As of yet, work on transparent conductive GDB (TCGDBs) is very limited. TCGDBs based on ZnO prepared by atomic layer deposition (ALD) have been reported. Due to the chemical instability of ZnO, it turns out that their electrical conductivity severely deteriorates by orders of magnitude upon exposure to damp heat conditions after very short time. We will show that these issues can be overcome by the use of tin oxide (SnO2). Conductivities of up to 300 S/cm and extremely low water vapor transmission rates (WVTR) on the order of 10-6 g/(m2 day) can been achieved in SnOx layers prepared by ALD at low temperatures (<150°C). A sandwich of SnOx/Ag/SnOx is shown to provide an average transmittance of 82% and a low sheet resistance of 9 Ohm/sq. At the same time the resulting electrodes are extremely robust. E.g., while unprotected Cu and Ag electrodes degrade within a few minutes at 85°C/85%rH (e.g. Cu lost 7 orders of magnitude in electrical conductivity), sandwich structures of SnOx/(Cu or Ag)/SnOx remain virtually unchanged even after 100 h. The SnOx in this work will also provide corrosion protection for the metal in case of harsh processing steps on top these electodes (e.g. acidic). We demonstrate the application of these TCGDBs as electrodes for organic solar cells and OLEDs.

  11. Highly Robust Silver Nanowire Network for Transparent Electrode.

    PubMed

    Song, Tze-Bin; Rim, You Seung; Liu, Fengmin; Bob, Brion; Ye, Shenglin; Hsieh, Yao-Tsung; Yang, Yang

    2015-11-11

    Solution-processed silver nanowire networks are one of the promising candidates to replace a traditional indium tin oxide as next-generation transparent and flexible electrodes due to their ease of processing, moderate flexibility, high transparency, and low sheet resistance. To date, however, high stability of the nanowire networks remains a major challenge because the long-term usages of these electrodes are limited by their poor thermal and chemical stabilities. Existing methods for addressing this challenge mainly focus on protecting the nanowire network with additional layers that require vacuum processes, which can lead to an increment in manufacturing cost. Here, we report a straightforward strategy of a sol-gel processing as a fast and robust way to improve the stabilities of silver nanowires. Compared with reported nanoparticles embedded in nanowire networks, better thermal and chemical stabilities are achieved via sol-gel coating of TiO2 over the silver nanowire networks. The conformal surface coverage suppressed surface diffusion of silver atoms and prevented chemical corrosion from the environment. These results highlight the important role of the functional layer in providing better thermal and chemical stabilities along with improved electrical properties and mechanical robustness. The silver nanowire/TiO2 composite electrodes were applied as the source and drain electrodes for In2O3 thin-film transistors (TFTs) and the devices exhibited improved electrical performance annealed at 300 °C without the degradation of the electrodes. These key findings not only demonstrated a general and effective method to improve the thermal and chemical stabilities of metal nanowire networks but also provided a basic guideline toward rational design of highly efficient and robust composite electrodes. PMID:26488682

  12. Monolithic Parallel Tandem Organic Photovoltaic Cell with Transparent Carbon Nanotube Interlayer

    NASA Technical Reports Server (NTRS)

    Tanaka, S.; Mielczarek, K.; Ovalle-Robles, R.; Wang, B.; Hsu, D.; Zakhidov, A. A.

    2009-01-01

    We demonstrate an organic photovoltaic cell with a monolithic tandem structure in parallel connection. Transparent multiwalled carbon nanotube sheets are used as an interlayer anode electrode for this parallel tandem. The characteristics of front and back cells are measured independently. The short circuit current density of the parallel tandem cell is larger than the currents of each individual cell. The wavelength dependence of photocurrent for the parallel tandem cell shows the superposition spectrum of the two spectral sensitivities of the front and back cells. The monolithic three-electrode photovoltaic cell indeed operates as a parallel tandem with improved efficiency.

  13. Conducting polymer composite film incorporated with aligned carbon nanotubes for transparent, flexible and efficient supercapacitor

    PubMed Central

    Lin, Huijuan; Li, Li; Ren, Jing; Cai, Zhenbo; Qiu, Longbin; Yang, Zhibin; Peng, Huisheng

    2013-01-01

    Polyaniline composite films incorporated with aligned multi-walled carbon nanotubes (MWCNTs) are synthesized through an easy electrodeposition process. These robust and electrically conductive films are found to function as effective electrodes to fabricate transparent and flexible supercapacitors with a maximum specific capacitance of 233 F/g at a current density of 1 A/g. It is 36 times of bare MWCNT sheet, 23 times of pure polyaniline and 3 times of randomly dispersed MWCNT/polyaniline film under the same conditions. The novel supercapacitors also show a high cyclic stability. PMID:23443325

  14. Transparent Conductive Coating Based on Carbon Nanotubes Using Electric Field Deposition Method

    SciTech Connect

    Latununuwe, Altje; Hattu, Nikmans; Setiawan, Andhy; Winata, Toto; Abdullah, Mikrajuddin; Darma, Yudi

    2010-10-24

    The transparent conductive coating based on carbon nanotubes (CNTs) had been fabricated using the electric field deposition method. The scanning electron microscope (SEM) results show a quite uniform CNTs on Corning glass substrates. Moreover the X-ray Diffraction (XRD) results shows the peak at around 25 deg. which proves the existence of CNT materials. The CNT thin films obtained with different deposition times have different transmittance coefficients at wavelength of 550 nm. I-V measurement results shows higher sheet resistance value which relates with bigger transmittance coefficients and vice versa.

  15. Tunable double transparency windows induced by single subradiant element in coupled graphene plasmonic nanostructure

    NASA Astrophysics Data System (ADS)

    Hu, Cheng; Wang, Lingling; Lin, Qi; Zhai, Xiang; Ma, Xiaoying; Han, Tao; Du, Jiang

    2016-05-01

    We present the coupling-induced transparency (CIT) effect by employing the localized surface plasmon mode supported by a periodic array of graphene nanoribbons destructively interfering with the quasiguided mode supported by a single-layer graphene sheet. It is found that the resonance strength and linewidth are strongly dependent on the coupling distance. It is also shown that the degeneracy between the symmetric and antisymmetric quasiguided modes is lifted owing to the oblique incidence, resulting in the double CIT effect with an ultrahigh figure of merit (FOM) (as high as 271), which may provide potential applications in dynamic optical switching and biochemical sensing.

  16. Electrochemical Characterization Laboratory (Fact Sheet)

    SciTech Connect

    Not Available

    2011-10-01

    This fact sheet describes the purpose, lab specifications, applications scenarios, and information on how to partner with NREL's Electrochemical Characterization Laboratory at the Energy Systems Integration Facility. The research focus at the Electrochemical Characterization Laboratory at NREL's Energy Systems Integration Facility (ESIF) is evaluating the electrochemical properties of novel materials synthesized by various techniques and understanding and delineating the reaction mechanisms to provide practical solutions to PEMFCs commercialization issues of cost, performance and durability. It is also involved in the development of new tools and techniques for electrochemical characterization. The laboratory concentrates on the development and characterization of new materials for PEMFCs such as electrocatalysts, catalyst supports in terms of electrochemical activity, electrochemical surface area and corrosion/durability. The impact of impurities and/or contaminants on the catalyst activity is also under study. Experiments that can be performed include: (1) Determination and benchmarking of novel electrocatalyst activity; (2) Determination of electrochemical surface area; (3) Determination of electrocatalyst and support corrosion resistance and durability; (4) Synthesis and characterization of novel electrocatalyst; (5) Determination of fundamental electrochemical parameters; and (6) Estimation of electrocatalyst utilization.

  17. Simultaneous observation of the poleward expansion of substorm electrojet activity and the tailward expansion of current sheet disruption in the near-earth magnetotail

    NASA Technical Reports Server (NTRS)

    Lopez, R. E.; Koskinen, H. E. J.; Pulkkinen, T. I.; Bosinger, T.; Mcentire, R. W.; Potemra, T. A.

    1993-01-01

    A substorm that occurred on 7 June 1985 at 2209 UT for which simultaneous measurements from ground stations and CCE are available is considered. The event occurred during a close conjunction between CCE, the EISCAT magnetometer cross, and the STARE radar, allowing a detailed comparison of satellite and ground-based data. Two discrete activations took place during the first few minutes of this substorm: the expansion phase onset at 2209 UT and an intensification at 2212 UT, corresponding to a poleward expansion of activity. The energetic particle data indicate that the active region of the magnetotail during the 2212 UT intensification was located tailward of the active region at 2209 UT. This is direct evidence for a correspondence between tailward expansion of localized activity in the near-earth magnetotail (current disruption and particle energization) and poleward expansion of activity (electrojet formation) in the ionosphere.

  18. Surface Modification of Silver Nanowires for Morphology and Processing Control in Composite Transparent Electrodes.

    PubMed

    Liang, Zhiming; Graham, Kenneth R

    2015-10-01

    Silver nanowires are attractive components for a number of materials and applications, including silver nanowire (AgNW)-polymer composites, electrically conductive coatings, and transparent electrodes. In this manuscript, the ability of thiols with hydrophobic to ionic end groups to bind to AgNW surfaces is investigated, followed by how the polarity of the surface modifying thiol influences the morphological and electrical properties of both AgNW/PEDOT:PSS blend films and pure AgNW networks. Utilizing surface modification of AgNWs with sodium 3-mercapto-1-propanesulfonate (MPS), morphologically homogeneous AgNW/PEDOT:PSS thin films with an order of magnitude lower sheet resistance at similar transmittance values than unmodified AgNWs are obtained with a one-step processing method. Brief optimization of MPS-AgNW/PEDOT:PSS blends yields a sheet resistance of 22.6 Ω/□ at 81.4% transmittance. PMID:26389535

  19. Fabrication of high aspect ratio nanogrid transparent electrodes via capillary assembly of Ag nanoparticles.

    PubMed

    Kang, Juhoon; Park, Chang-Goo; Lee, Su-Han; Cho, Changsoon; Choi, Dae-Geun; Lee, Jung-Yong

    2016-06-01

    In this report, we describe the fabrication of periodic Ag nanogrid electrodes by capillary assembly of silver nanoparticles (AgNPs) along patterned nanogrid templates. By assembling the AgNPs into these high-aspect-ratio nanogrid patterns, we can obtain high-aspect-ratio nanogratings, which can overcome the inherent trade-off between the optical transmittance and the sheet resistance of transparent electrodes. The junction resistance between the AgNPs is effectively reduced by photochemical welding and post-annealing. The fabricated high-aspect-ratio nanogrid structure with a line width of 150 nm and a height of 450 nm has a sheet resistance of 15.2 Ω sq(-1) and an optical transmittance of 85.4%. PMID:27187802

  20. Wind Powering America Initiative (Fact Sheet)

    SciTech Connect

    Not Available

    2011-01-01

    The U.S. Department of Energy's Wind Powering America initiative engages in technology market acceptance, barrier reduction, and technology deployment support activities. This fact sheet outlines ways in which the Wind Powering America team works to reduce barriers to appropriate wind energy deployment, primarily by focusing on six program areas: workforce development, communications and outreach, stakeholder analysis and resource assessment, wind technology technical support, wind power for Native Americans, and federal sector support and collaboration.