8,065 research outputs found

    Definition of Throw-Away Detectors (TADs) and VLF antenna for the AMPS laboratory

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    A Throw Away Detector (TAD)/subsatellite to be used as an experiment platform for the test flights to map the EMI from the shuttle and during the AMPS science flights is defined. A range of instrument platforms of varying capabilities is examined with emphasis on the EMI test vehicle. The operational support requirements of TAD/subsatellites are determined. The throw away detector is envisioned as a simple instrument package for supporting specific experiments

    The 30-cm ion thruster power processor

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    A power processor unit for powering and controlling the 30 cm Mercury Electron-Bombardment Ion Thruster was designed, fabricated, and tested. The unit uses a unique and highly efficient transistor bridge inverter power stage in its implementation. The system operated from a 200 to 400 V dc input power bus, provides 12 independently controllable and closely regulated dc power outputs, and has an overall power conditioning capacity of 3.5 kW. Protective circuitry was incorporated as an integral part of the design to assure failure-free operation during transient and steady-state load faults. The implemented unit demonstrated an electrical efficiency between 91.5 and 91.9 at its nominal rated load over the 200 to 400 V dc input bus range

    Index to NASA Tech Briefs, January - June 1967

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    Technological innovations for January-June 1967, abstracts and subject inde

    Feed system design and experimental results in the uhf model study for the proposed Urbana phased array

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    The effects of atmospheric turbulence and the basis for the coherent scatter radar techniques are discussed. The reasons are given for upgrading the Radar system to a larger steerable array. Phase array theory pertinent to the system design is reviewed, along with approximations for maximum directive gain and blind angles due to mutual coupling. The methods and construction techniques employed in the UHF model study are explained. The antenna range is described, with a block diagram for the mode of operation used

    Recent advances in the hardware architecture of flat display devices

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    Thesis (Master)--Izmir Institute of Technology, Electronics and Communication Engineering, Izmir, 2007Includes bibliographical References (leaves: 115-117)Text in English; Abstract: Turkish and Englishxiii, 133 leavesThesis will describe processing board hardware design for flat panel displays with integrated digital reception, the design challenges in flat panel displays with integrated digital reception explained with details. Thesis also includes brief explanation of flat panel technology and processing blocks. Explanations of building blocks of TV and flat panel displays are given before design stage for better understanding of design stage. Hardware design stage of processing board is investigated in two major steps, schematic design and layout design. First step of the schematic design is system level block diagram design. Schematic diagram is the detailed application level hardware design and layout is the implementation level of the design. System level, application level and implementation level hardware design of the TV processing board is described with details in thesis. Design challenges, considerations and solutions are defined in advance for flat panel displays

    Optical Yagi-Uda nanoantennas

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    Conventional antennas, which are widely employed to transmit radio and TV signals, can be used at optical frequencies as long as they are shrunk to nanometer-size dimensions. Optical nanoantennas made of metallic or high-permittivity dielectric nanoparticles allow for enhancing and manipulating light on the scale much smaller than wavelength of light. Based on this ability, optical nanoantennas offer unique opportunities regarding key applications such as optical communications, photovoltaics, non-classical light emission, and sensing. From a multitude of suggested nanoantenna concepts the Yagi-Uda nanoantenna, an optical analogue of the well-established radio-frequency Yagi-Uda antenna, stands out by its efficient unidirectional light emission and enhancement. Following a brief introduction to the emerging field of optical nanoantennas, here we review recent theoretical and experimental activities on optical Yagi-Uda nanoantennas, including their design, fabrication, and applications. We also discuss several extensions of the conventional Yagi-Uda antenna design for broadband and tunable operation, for applications in nanophotonic circuits and photovoltaic devices

    Phase 2 of the array automated assembly task for the low cost solar array project

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    The process sequence for the fabrication of dendritic web silicon into solar panels was modified to include aluminum back surface field formation. Plasma etching was found to be a feasible technique for pre-diffusion cleaning of the web. Several contacting systems were studied. The total plated Pd-Ni system was not compatible with the process sequence; however, the evaporated TiPd-electroplated Cu system was shown stable under life testing. Ultrasonic bonding parameters were determined for various interconnect and contact metals but the yield of the process was not sufficiently high to use for module fabrication at this time. Over 400 solar cells were fabricated according to the modified sequence. No sub-process incompatibility was seen. These cells were used to fabricate four demonstration modules. A cost analysis of the modified process sequence resulted in a selling price of $0.75/peak watt

    Surface charge reversal method for high-resolution inkjet printing of functional water-based inks

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    © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Printed electronics is a rapidly growing area of research being explored for the manufacture of large-area and cost-effective electronic devices by the patterned application of functional inks. There are challenges associated with processing the inks compatible with inkjet printing technology and developing effi cient methods to successfully obtain the desired features, particularly when it comes to metal and metal-organic complex inks. Here, a reliable method is developed to achieve a sophisticated microstructured pattern using the inkjet printing technique assisted by a surface charge reversal effect. In addition, a procedure is formulated to obtain good quality, stable metal-organic water-based inks compatible with salts of a variety of transition metals and rare earths, without the need for additional volatile solvents. A feasible and water-based ink formulation combined with a simple and noninvasive surface charge reversal treatment constitutes a major step toward the manufacture of high-resolution, inorganic patterned thin fi lms on hydrophobic substrates using inkjet printing. These outcomes lead to the path of effective fusion of inorganic and organic heterointerfaces by simples designing and printing.This work was supported by the University of New South Wales and Spanish MICINN (Consolider CSD2007-0041). A portion of this work was performed at the ACT node of the Australian National Fabrication Facility. The authors wish to acknowledge Dr. F. Kremer for the electron diffraction measurement.Peer Reviewe
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