National Library of Energy BETA

Sample records for v-shaped gold antennas

  1. V-shaped resonators for addition of broad-area laser diode arrays

    DOE Patents [OSTI]

    Liu, Bo; Liu, Yun; Braiman, Yehuda Y.

    2012-12-25

    A system and method for addition of broad-area semiconductor laser diode arrays are described. The system can include an array of laser diodes, a V-shaped external cavity, and grating systems to provide feedback for phase-locking of the laser diode array. A V-shaped mirror used to couple the laser diode emissions along two optical paths can be a V-shaped prism mirror, a V-shaped stepped mirror or include multiple V-shaped micro-mirrors. The V-shaped external cavity can be a ring cavity. The system can include an external injection laser to further improve coherence and phase-locking.

  2. Self-propulsion of V-shape micro-robot

    E-Print Network [OSTI]

    Vladimir A. Vladimirov

    2012-09-13

    In this paper we study the self-propulsion of a symmetric V-shape micro-robot (or V-robot) which consists of three spheres connected by two arms with an angle between them; the arms' lengths and the angle are changing periodically. Using an asymptotic procedure containing two-timing method and a distinguished limit, we obtain analytic expressions for the self-propulsion velocity and Lighthill's efficiency. The calculations show that a version of V-robot, aligned perpendicularly to the direction of self-swimming, is both the fastest one and the most efficient one. We have also shown that such $V$-robot is faster and more efficient than a linear three-sphere micro-robot. At the same time the maximal self-propulsion velocity of V-robots is significantly smaller than that of comparable microorganisms.

  3. Characterization of V-shaped defects in 4H-SiC homoepitaxial layers

    SciTech Connect (OSTI)

    Zhang, Lihua; Su, Dong; Kisslinger, Kim; Stach, Eric; Chung, Gil; Zhang, Jie; Thomas, Bernd; Sanchez, Edward K; Mueller, Stephan G.; Hansen, Darren; Loboda, Mark J.; Wu, Fangzhen; Wang, Huanhuan; Raghothamachar, Balaji; Dudley, Michael

    2014-12-04

    Synchrotron white beam x-ray topography images show that faint needle-like surface morphological features observed on the Si-face of 4H-SiC homoepitaxial layers using Nomarski optical microscopy are associated with V shaped stacking faults in the epilayer. KOH etching of the V shaped defect reveals small oval pits connected by a shallow line which corresponding to the surface intersections of two partial dislocations and the stacking fault connecting them. Transmission electron microscopy (TEM) specimens from regions containing the V shaped defects were prepared using focused ion beam milling, and stacking sequences of (85), (50) and (63) are observed at the faulted region with high resolution TEM. In order to study the formation mechanism of V shaped defect, low dislocation density 4H-SiC substrates were chosen for epitaxial growth, and the corresponding regions before and after epitaxy growth are compared in SWBXT images. It is found that no defects in the substrate are directly associated with the formation of the V shaped defect. Simulation results of the contrast from the two partial dislocations associated with V shaped defect in synchrotron monochromatic beam x-ray topography reveals the opposite sign nature of their Burgers vectors. Therefore, a mechanism of 2D nucleation during epitaxy growth is postulated for the formation of the V shaped defect, which requires elimination of non-sequential 1/4[0001] bilayers from the original structure to create the observed faulted stacking sequence.

  4. Characterization of V-shaped defects in 4H-SiC homoepitaxial layers

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zhang, Lihua; Su, Dong; Kisslinger, Kim; Stach, Eric; Chung, Gil; Zhang, Jie; Thomas, Bernd; Sanchez, Edward K; Mueller, Stephan G.; Hansen, Darren; et al

    2014-12-04

    Synchrotron white beam x-ray topography images show that faint needle-like surface morphological features observed on the Si-face of 4H-SiC homoepitaxial layers using Nomarski optical microscopy are associated with V shaped stacking faults in the epilayer. KOH etching of the V shaped defect reveals small oval pits connected by a shallow line which corresponding to the surface intersections of two partial dislocations and the stacking fault connecting them. Transmission electron microscopy (TEM) specimens from regions containing the V shaped defects were prepared using focused ion beam milling, and stacking sequences of (85), (50) and (63) are observed at the faulted regionmore »with high resolution TEM. In order to study the formation mechanism of V shaped defect, low dislocation density 4H-SiC substrates were chosen for epitaxial growth, and the corresponding regions before and after epitaxy growth are compared in SWBXT images. It is found that no defects in the substrate are directly associated with the formation of the V shaped defect. Simulation results of the contrast from the two partial dislocations associated with V shaped defect in synchrotron monochromatic beam x-ray topography reveals the opposite sign nature of their Burgers vectors. Therefore, a mechanism of 2D nucleation during epitaxy growth is postulated for the formation of the V shaped defect, which requires elimination of non-sequential 1/4[0001] bilayers from the original structure to create the observed faulted stacking sequence.« less

  5. Integrated broadband bowtie antenna on transparent substrate

    E-Print Network [OSTI]

    Zhang, Xingyu; Subbaraman, Harish; Zhan, Qiwen; Pan, Zeyu; Chung, Chi-jui; Yan, Hai; Chen, Ray T

    2015-01-01

    The bowtie antenna is a topic of growing interest in recent years. In this paper, we design, fabricate, and characterize a modified gold bowtie antenna integrated on a transparent glass substrate. We numerically investigate the antenna characteristics, specifically its resonant frequency and enhancement factor. We simulate the dependence of resonance frequency on bowtie geometry, and verify the simulation results through experimental investigation, by fabricating different sets of bowtie antennas on glass substrates utilizing CMOS compatible processes and measuring their resonance frequencies. Our designed bowtie antenna provides a strong broadband electric field enhancement in its feed gap. The far-field radiation pattern of the bowtie antenna is measured, and it shows dipole-like characteristics with large beam width. Such a broadband antenna will be useful for a myriad of applications, ranging from wireless communications to electromagnetic wave detection.

  6. PHYSICS OF FLUIDS 25, 055107 (2013) Turbulent premixed combustion in V-shaped flames

    E-Print Network [OSTI]

    Gülder, Ömer L.

    2013-01-01

    industrial combustion systems such as, stationary gas turbines, lean premixed and prevaporized jet engines for simulating combustion in gas turbine engines. Second, although a large body of research has been devotedPHYSICS OF FLUIDS 25, 055107 (2013) Turbulent premixed combustion in V-shaped flames

  7. Turbulent heat transfer in a trapezoidal channel with transverse and v-shaped ribs on two opposite walls 

    E-Print Network [OSTI]

    Subramanian, Karthik

    2006-04-12

    This study investigates the turbulent heat transfer and friction in a trapezoidal channel with opposite walls roughened with transverse and v-shaped ribs. The roughened channel depicts the internal cooling passage of an aerofoil near the trailing...

  8. Heat Transfer and Pressure Drop Measurement for Square Channels with V-shape Ribs at High Reynolds Numbers 

    E-Print Network [OSTI]

    Alkhamis, Nawaf Yahya

    2010-10-12

    for the degree of MASTER OF SCIENCE August 2009 Major Subject: Mechanical Engineering HEAT TRANSFER AND PRESSURE DROP MEASUREMENT FOR SQUARE CHANNELS WITH V-SHAPE RIBS AT HIGH REYNOLDS NUMBERS A Thesis by NAWAF YAHYA ALKHAMIS... of Department, Dennis O?Neal August 2009 Major Subject: Mechanical Engineering iii ABSTRACT Heat Transfer and Pressure Drop Measurement for Square Channels with V-shape Ribs at High Reynolds Numbers. (August 2009) Nawaf Yahya Alkhamis, B.Sc King...

  9. Wideband active antenna cancellation

    E-Print Network [OSTI]

    Adaniya, Hana L

    2008-01-01

    There exists a simultaneous transmit and receive antenna system where the transmitted signal is creating wideband interference of the receiver. To resolve this interference problem, the isolation between the transmit antenna ...

  10. Hidden Gold 

    E-Print Network [OSTI]

    Abernathy, L. L.

    1988-01-01

    required. The results were surprising. HIDDEN GOLD The day had been hot and the haze kept us from seeing the success of the other barge. The drumming sound of the dredge pumps had a mono tonous tone as Joe and I watched massive quantities of ssnd... and the jungle beyond. We had been dredging in this delta for about four years since Ed, the company president, had discovered a nugget near the bank. I wondered why we had never followed the river upstream to find the source of this gold? The thought...

  11. Gold Nanoantennas

    SciTech Connect (OSTI)

    2012-01-01

    An array of gold nanoantennas laced into an artificial membrane enhances the fluorescence intensity of three different molecules when they pass through plasmonic hot spots in the array. Watch for the blue, green and red flashes. The photobleaching at the end of each fluorescence event (white flashes) is indicative of single molecule observations.

  12. DIPLOMA THESIS VECTOR ANTENNA FOR

    E-Print Network [OSTI]

    Considerations 17 3.8 Ultra HighEnergy Cosmic Neutrino (UHEC) Antanna 17 4 Mechanical Construction 19 4 for a 3D object 21 5 Vector Antenna performance 35 5.1 Electrical Properties of the Antenna Medium or Environment 35 5.1.1 Electromagnetic Wave in Ice 35 5.2 UHEC Antenna Amplification 35 5.3 Vector Measurements

  13. Quartz antenna with hollow conductor

    DOE Patents [OSTI]

    Leung, Ka-Ngo (Hercules, CA); Benabou, Elie (Alameda, CA)

    2002-01-01

    A radio frequency (RF) antenna for plasma ion sources is formed of a hollow metal conductor tube disposed within a glass tube. The hollow metal tubular conductor has an internal flow channel so that there will be no coolant leakage if the outer glass tube of the antenna breaks. A portion of the RF antenna is formed into a coil; the antenna is used for inductively coupling RF power to a plasma in an ion source chamber. The antenna is made by first inserting the metal tube inside the glass tube, and then forming the glass/metal composite tube into the desired coil shape.

  14. When Green Turns to Gold | Photosynthetic Antenna Research Center

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effectWorking WithTelecentricNCubicthe FOIA? The FOIA, Title 5,What'sWhen Green

  15. Efficient Placement of Directional Antennas

    SciTech Connect (OSTI)

    Pan, Feng; Kasiviswanathan, Shiva

    2010-09-20

    Directional antenna is an technology for the proliferation of wireless networks. In centralized wireless network, wireless devices communicate through base stations. Directed antennas are placed on base stations and form a backbone of communication. The communication between base stations and wireless devices can be interfered due to a large number of wireless device. Methodically positioning and orienting directed antennas can help to reduce the interference while saving energy. An integer linear programming is developed for siting and directing antennas on multiple base stations, and this formulation can be extended to model non-overlapping channels. Through the integer programming formulation, optimal antenna positions can be used to analyze the performance of directed antennas with different parameters like the number base stations and the number of non-overlapping channels.

  16. Antenna structure with distributed strip

    DOE Patents [OSTI]

    Rodenbeck, Christopher T. (Albuquerque, NM)

    2008-10-21

    An antenna comprises electrical conductors arranged to form a radiating element including a folded line configuration and a distributed strip configuration, where the radiating element is in proximity to a ground conductor. The folded line and the distributed strip can be electrically interconnected and substantially coplanar. The ground conductor can be spaced from, and coplanar to, the radiating element, or can alternatively lie in a plane set at an angle to the radiating element. Embodiments of the antenna include conductor patterns formed on a printed wiring board, having a ground plane, spacedly adjacent to and coplanar with the radiating element. Other embodiments of the antenna comprise a ground plane and radiating element on opposed sides of a printed wiring board. Other embodiments of the antenna comprise conductors that can be arranged as free standing "foils". Other embodiments include antennas that are encapsulated into a package containing the antenna.

  17. Antenna structure with distributed strip

    DOE Patents [OSTI]

    Rodenbeck, Christopher T. (Albuquerque, NM)

    2008-03-18

    An antenna comprises electrical conductors arranged to form a radiating element including a folded line configuration and a distributed strip configuration, where the radiating element is in proximity to a ground conductor. The folded line and the distributed strip can be electrically interconnected and substantially coplanar. The ground conductor can be spaced from, and coplanar to, the radiating element, or can alternatively lie in a plane set at an angle to the radiating element. Embodiments of the antenna include conductor patterns formed on a printed wiring board, having a ground plane, spacedly adjacent to and coplanar with the radiating element. Other embodiments of the antenna comprise a ground plane and radiating element on opposed sides of a printed wiring board. Other embodiments of the antenna comprise conductors that can be arranged as free standing "foils". Other embodiments include antennas that are encapsulated into a package containing the antenna.

  18. Design Issues on Broadcast Routing Algorithms using Realistic Cost-Effective Smart Antenna Models

    E-Print Network [OSTI]

    Poovendran, Radha

    antennas includes ESPAR antenna [7]. To deal with complex algorithms, adaptive array antenna requires

  19. Multiple frequency printed slot and dipole antennas 

    E-Print Network [OSTI]

    Kolsrud, Arild

    1997-01-01

    frequencies. Adding one varactor diode to the slot antenna or two diodes to the dipole either switching or tuning of the antenna could be achieved....

  20. PERFORMANCE OF CdSe TETRAPODS-GOLD AS NANOSTRUCTURE ELECTROCHEMICAL MATERIALS IN PHOTOVOLTAIC CELLS

    E-Print Network [OSTI]

    Natelson, Douglas

    PERFORMANCE OF CdSe TETRAPODS-GOLD AS NANOSTRUCTURE ELECTROCHEMICAL MATERIALS IN PHOTOVOLTAIC CELLS antenna arrays are assembled by coating on CdSe tetrapod templates; the rectifying barrier is formed and reduce the costs associated with conventional solar cells, including multi-bandgap materials [5

  1. *Corresponding author: Lilia Manach (lilia.manach@univ-rennes1.fr) PERFORMANCE OF A LOZENGE MONOPOLE ANTENNA MADE OF

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    conductive composite materials as a replacement for metals [1-3]. A patch antenna has been fabricated from a conducting-polymer in [1], or from a textile coated with carbon nanotubes (CNTs) and gold in [2]. Inkjet, conductive composite panels can act as hal-00743812,version1-13May2014 Author manuscript, published

  2. Ion source with external RF antenna

    DOE Patents [OSTI]

    Leung, Ka-Ngo; Ji, Qing; Wilde, Stephen

    2005-12-13

    A radio frequency (RF) driven plasma ion source has an external RF antenna, i.e. the RF antenna is positioned outside the plasma generating chamber rather than inside. The RF antenna is typically formed of a small diameter metal tube coated with an insulator. An external RF antenna assembly is used to mount the external RF antenna to the ion source. The RF antenna tubing is wound around the external RF antenna assembly to form a coil. The external RF antenna assembly is formed of a material, e.g. quartz, which is essentially transparent to the RF waves. The external RF antenna assembly is attached to and forms a part of the plasma source chamber so that the RF waves emitted by the RF antenna enter into the inside of the plasma chamber and ionize a gas contained therein. The plasma ion source is typically a multi-cusp ion source.

  3. Smart antennas based on graphene

    SciTech Connect (OSTI)

    Aldrigo, Martino; Dragoman, Mircea; Dragoman, Daniela

    2014-09-21

    We report two configurations of smart graphene antennas, in which either the radiation pattern of the antenna or the backscattering of the periodic metallic arrays is controlled by DC biases that induce metal-insulator reversible transitions of graphene monolayers. Such a transition from a high surface resistance (no bias) to a low surface resistance state (finite bias voltage) causes the radiation pattern of metallic antennas backed with graphene to change dramatically, from omnidirectional to broadside. Moreover, reflectarrays enhance the backscattered field due to the same metal-dielectric transition.

  4. Electrically floating, near vertical incidence, skywave antenna

    DOE Patents [OSTI]

    Anderson, Allen A.; Kaser, Timothy G.; Tremblay, Paul A.; Mays, Belva L.

    2014-07-08

    An Electrically Floating, Near Vertical Incidence, Skywave (NVIS) Antenna comprising an antenna element, a floating ground element, and a grounding element. At least part of said floating ground element is positioned between said antenna element and said grounding element. The antenna is separated from the floating ground element and the grounding element by one or more electrical insulators. The floating ground element is separated from said antenna and said grounding element by one or more electrical insulators.

  5. Noah Golding | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Noah Golding About Us Noah Golding - Communications Specialist, Wind and Water Power Technologies Office Most Recent Winning with Wind: Electric Co-ops Providing Clean Energy to...

  6. Going green earns Laboratory gold

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Going green earns Laboratory gold Going green earns Laboratory gold The Laboratory's newest facility is its first to achieve both the Leadership in Energy and Environmental Design...

  7. Electrically-driven optical antennas

    E-Print Network [OSTI]

    Kern, Johannes; Prangsma, Jord C; Emmerling, Monika; Kamp, Martin; Hecht, Bert

    2015-01-01

    Unlike radiowave antennas, optical nanoantennas so far cannot be fed by electrical generators. Instead, they are driven by light or via optically active materials in their proximity. Here, we demonstrate direct electrical driving of an optical nanoantenna featuring an atomic-scale feed gap. Upon applying a voltage, quantum tunneling of electrons across the feed gap creates broadband quantum shot noise. Its optical frequency components are efficiently converted into photons by the antenna. We demonstrate that the properties of the emitted photons are fully controlled by the antenna architecture, and that the antenna improves the quantum efficiency by up to two orders of magnitude with respect to a non-resonant reference system. Our work represents a new paradigm for interfacing electrons and photons at the nanometer scale, e.g. for on-chip wireless data communication, electrically driven single- and multiphoton sources, as well as for background-free linear and nonlinear spectroscopy and sensing with nanometer...

  8. Fin-line horn antenna

    DOE Patents [OSTI]

    Reindel, John (San Diego, CA)

    1990-01-01

    A fin line circuit card containing a fin line slot feeds a dipole antenna ich extends a quarterwave outside the waveguide and provides an energy beam focal point at or near the open end of the waveguide. The dipole antenna thus maintains a wide and nearly constant beamwidth, low VSWR and a circular symmetric radiation pattern for use in electronic warfare direction finding and surveillance applications.

  9. Wideband dual-linear polarized microstrip patch antenna 

    E-Print Network [OSTI]

    Smith, Christopher Brian

    2009-05-15

    Due to the recent interest in broadband antennas a microstrip patch antenna was developed to meet the need for a cheap, low profile, broadband antenna. This antenna could be used in a wide range of applications such as in ...

  10. Texas Gold Rush 

    E-Print Network [OSTI]

    Wythe, Kathy

    2006-01-01

    stream_source_info Texas Gold Rush.pdf.txt stream_content_type text/plain stream_size 10484 Content-Encoding ISO-8859-1 stream_name Texas Gold Rush.pdf.txt Content-Type text/plain; charset=ISO-8859-1 tx H2O | pg. 6... Texas Gold Rush Story by Kathy Wythe A free-floating microscopic alga is increasingly appearing in some Texas lakes and rivers, releasing its deadly toxins and wiping out millions of fish. Texas scientists have taken on the assignment...

  11. WRAP AROUND MICROSTRIP ANTENNA FOR RADIO

    E-Print Network [OSTI]

    · MOUNT ANTENNA ON MAST · PLACE 917.88MHz TRANSMITTER ON ANOTHER MAST AND PLACE APPROX 50 FEET FROM #12;RADIATION OF WRAP AROUND ANTENNA #12;In Comparison #12;BUDGET Vendor Product Price Amount Total

  12. Passive and active Reconfigurable antenna design

    E-Print Network [OSTI]

    Pfeifer, Holger

    and technology context - System integration - Semiconductor technologies and devices - MMIC design: MMICPassive and active Reconfigurable antenna design Doctoral course ­ Ulm, Germany - October 8-12 2012 - Introduction to components - Performance parameters for components - Microwave circuit and antenna analysis

  13. Superconducting nanowire single-photon detectors integrated with optical nano-antennae

    SciTech Connect (OSTI)

    Hu, X.; Dauler, E.; Molnar, R.; Berggren, K. K.

    2010-12-20

    Optical nano-antennae have been integrated with semiconductor lasers to intensify light at the nanoscale and photodiodes to enhance photocurrent. In quantum optics, plasmonic metal structures have been used to enhance nonclassical light emission from single quantum dots. Absorption and detection of single photons from free space could also be enhanced by nanometallic antennae, but this has not previously been demonstrated. Here, we use nano-optical transmission effects in a one-dimensional gold structure, combined with optical cavity resonance, to form optical nano-antennae, which are further used to couple single photons from free space into a 80-nm-wide superconducting nanowire. This antenna-assisted coupling enables a superconducting nanowire single-photon detector with 47% device efficiency at the wavelength of 1550 nm and 9-?m-by-9-?m active area while maintaining a reset time of only 5 ns. We demonstrate nanoscale antenna-like structures to achieve exceptional efficiency and speed in single-photon detection.

  14. Compact Low Frequency Radio Antenna

    DOE Patents [OSTI]

    Punnoose, Ratish J. (Hayward, CA)

    2008-11-11

    An antenna is disclosed that comprises a pair of conductive, orthogonal arches and a pair of conductive annular sector plates, wherein adjacent legs of each arch are fastened to one of the annular sector plates and the opposite adjacent pair of legs is fastened to the remaining annular sector plate. The entire antenna structure is spaced apart from a conductive ground plane by a thin dielectric medium. The antenna is driven by a feed conduit passing through the conductive ground plane and dielectric medium and attached to one of the annular sector plates, wherein the two orthogonal arched act as a pair of crossed dipole elements. This arrangement of elements provides a radiation pattern that is largely omni-directional above the horizon.

  15. Antenna coupled photonic wire lasers

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Reno, John L.; Kao, Tsung-Kao; Cai, Xiaowei; Lee, Alan W. M.; Hu, Qing

    2015-06-22

    Slope efficiency (SE) is an important performance metric for lasers. In conventional semiconductor lasers, SE can be optimized by careful designs of the facet (or the modulation for DFB lasers) dimension and surface. However, photonic wire lasers intrinsically suffer low SE due to their deep sub-wavelength emitting facets. Inspired by microwave engineering techniques, we show a novel method to extract power from wire lasers using monolithically integrated antennas. These integrated antennas significantly increase the effective radiation area, and consequently enhance the power extraction efficiency. When applied to wire lasers at THz frequency, we achieved the highest single-side slope efficiency (~450more »mW/A) in pulsed mode for DFB lasers at 4 THz and a ~4x increase in output power at 3 THz compared with a similar structure without antennas. This work demonstrates the versatility of incorporating microwave engineering techniques into laser designs, enabling significant performance enhancements.« less

  16. Nested-cone transformer antenna

    DOE Patents [OSTI]

    Ekdahl, C.A.

    1991-05-28

    A plurality of conical transmission lines are concentrically nested to form an output antenna for pulsed-power, radio-frequency, and microwave sources. The diverging conical conductors enable a high power input density across a bulk dielectric to be reduced below a breakdown power density at the antenna interface with the transmitting medium. The plurality of cones maintain a spacing between conductors which minimizes the generation of high order modes between the conductors. Further, the power input feeds are isolated at the input while enabling the output electromagnetic waves to add at the transmission interface. Thus, very large power signals from a pulse rf, or microwave source can be radiated. 6 figures.

  17. Nested-cone transformer antenna

    DOE Patents [OSTI]

    Ekdahl, Carl A. (Santa Fe, NM)

    1991-01-01

    A plurality of conical transmission lines are concentrically nested to form n output antenna for pulsed-power, radio-frequency, and microwave sources. The diverging conical conductors enable a high power input density across a bulk dielectric to be reduced below a breakdown power density at the antenna interface with the transmitting medium. The plurality of cones maintain a spacing between conductors which minimizes the generation of high order modes between the conductors. Further, the power input feeds are isolated at the input while enabling the output electromagnetic waves to add at the transmission interface. Thus, very large power signals from a pulse rf, or microwave source can be radiated.

  18. Derivatized gold clusters and antibody-gold cluster conjugates

    DOE Patents [OSTI]

    Hainfeld, J.F.; Furuya, F.R.

    1994-11-01

    Antibody- or antibody fragment-gold cluster conjugates are shown wherein the conjugate size can be as small as 5.0 nm. Methods and reagents are disclosed in which antibodies, Fab' or F(ab')[sub 2] fragments are covalently bound to a stable cluster of gold atoms. The gold clusters may contain 6, 8, 9, 11, 13, 55 or 67 gold atoms in their inner core. The clusters may also contain radioactive gold. The antibody-cluster conjugates are useful in electron microscopy applications as well as in clinical applications that include imaging, diagnosis and therapy. 7 figs.

  19. Negative ion source with external RF antenna

    DOE Patents [OSTI]

    Leung, Ka-Ngo; Hahto, Sami K.; Hahto, Sari T.

    2007-02-13

    A radio frequency (RF) driven plasma ion source has an external RF antenna, i.e. the RF antenna is positioned outside the plasma generating chamber rather than inside. The RF antenna is typically formed of a small diameter metal tube coated with an insulator. An external RF antenna assembly is used to mount the external RF antenna to the ion source. The RF antenna tubing is wound around the external RF antenna assembly to form a coil. The external RF antenna assembly is formed of a material, e.g. quartz, which is essentially transparent to the RF waves. The external RF antenna assembly is attached to and forms a part of the plasma source chamber so that the RF waves emitted by the RF antenna enter into the inside of the plasma chamber and ionize a gas contained therein. The plasma ion source is typically a multi-cusp ion source. A converter can be included in the ion source to produce negative ions.

  20. Small internal ceramic chip antenna for IMT-2000 handsets

    E-Print Network [OSTI]

    Park, Seong-Ook

    Small internal ceramic chip antenna for IMT-2000 handsets D.S. Yim and S.O. Park A small internal ceramic chip antenna for IMT-2000 handsets is investigated experimentally and numerically. It has), meander-line antenna (MLA) and ceramic chip antenna (CCA), have been introduced [1­3]. The antenna

  1. Mechanical Measurements of the ALMA Prototype Antennas

    E-Print Network [OSTI]

    A. Greve; J. G. Mangum

    2007-10-30

    The specifications of the Atacama Large Millimeter Array (ALMA) have placed stringent requirements on the mechanical performance of its antennas. As part of the evaluation process of the VertexRSI and Alcatel EIE Consortium (AEC) ALMA prototype antennas, measurements of the path length, thermal, and azimuth bearing performance were made under a variety of weather conditions and observing modes. The results of mechanical measurements, reported here, are compared to the antenna specifications.

  2. The New Gold Standard: Environmental Management Introduces the...

    Energy Savers [EERE]

    The New Gold Standard: Environmental Management Introduces the First LEED Gold Industrial Facility The New Gold Standard: Environmental Management Introduces the First LEED Gold...

  3. Spontaneous Emission Rate Enhancement Using Optical Antennas

    E-Print Network [OSTI]

    Kumar, Nikhil

    2013-01-01

    radiation resistance and the load, leading to our conclusion that the with antenna power dimensions the reason of why cell phones

  4. School of Engineering and Computer Science ECE 471: Antenna Design and Analysis

    E-Print Network [OSTI]

    regarding antenna design and measurement. K-1. Fabricate and measure antenna systems using milling machine

  5. Surface-stabilized gold nanocatalysts

    DOE Patents [OSTI]

    Dai, Sheng (Knoxville, TN) [Knoxville, TN; Yan, Wenfu (Oak Ridge, TN) [Oak Ridge, TN

    2009-12-08

    A surface-stabilized gold nanocatalyst includes a solid support having stabilizing surfaces for supporting gold nanoparticles, and a plurality of gold nanoparticles having an average particle size of less than 8 nm disposed on the stabilizing surfaces. The surface-stabilized gold nanocatalyst provides enhanced stability, such as at high temperature under oxygen containing environments. In one embodiment, the solid support is a multi-layer support comprising at least a first layer having a second layer providing the stabilizing surfaces disposed thereon, the first and second layer being chemically distinct.

  6. Antibody-gold cluster conjugates

    DOE Patents [OSTI]

    Hainfeld, J.F.

    1988-06-28

    Antibody- or antibody fragment-gold cluster conjugates are shown wherein the conjugate size can be about 5.0 nm. Methods and reagents are disclosed in which antibodies or Fab' fragments thereof are covalently bound to a stable cluster of gold atoms. 2 figs.

  7. Wireless communication capability of a reconfigurable plasma antenna

    SciTech Connect (OSTI)

    Kumar, Rajneesh [Institute for Plasma Research, Bhat, Gandhinagar - 382428 (India); Bora, Dhiraj [ITER Organisation, Cadarache-13108 (France)

    2011-03-15

    A 30 cm long plasma column is excited by a surface wave, which acts as a plasma antenna. Using plasma properties (pattern formation/striations in plasmas) single plasma antenna can be transformed into array, helical, and spiral plasma antenna. Experiments are carried out to study the power patterns, directivity, and half power beam width of such different plasma antennas. Moreover, field properties of plasma and copper antenna are studied. Further, wireless communication and jamming capability of plasma antenna are tested. Findings of this study suggest that directivity and communication range can be increased by converting single plasma antenna in to array/helical/spiral plasma antenna. Field frequencies of plasma antenna determine the communication and jamming of radio frequency waves. Therefore, this study invokes applications of pattern formation or striations of plasmas in plasma antenna technology.

  8. Detection of electromagnetic waves using MEMS antennas

    SciTech Connect (OSTI)

    Lavrik, Nickolay V [ORNL] [ORNL; Tobin, [Oak Ridge National Laboratory (ORNL)] [Oak Ridge National Laboratory (ORNL); Bowland, Landon T [ORNL] [ORNL

    2011-01-01

    We describe the design, fabrication and characterization of simple micromechanical structures that are capable of sensing static electric time varying electromagnetic fields. Time varying electric field sensing is usually achieved using an electromagnetic antenna and a receiver. However, these antenna-based approaches do not exhibit high sensitivity over a broad frequency (or wavelength) range. An important aspect of the present work is that, in contrast to traditional antennas, the dimensions of these micromechanical oscillators can be much smaller than the wavelength of the electromagnetic wave. We characterized the fabricated micromechanical oscillators by measuring their responses to time varying electric and electromagnetic fields.

  9. Microwave mode shifting antenna system for regenerating particulate filters

    DOE Patents [OSTI]

    Gonze, Eugene V [Pinckney, MI; Kirby, Kevin W [Calabasas Hills, CA; Phelps, Amanda [Malibu, CA; Gregoire, Daniel J [Thousand Oaks, CA

    2011-04-26

    A regeneration system comprises a particulate matter (PM) filter including a microwave energy absorbing surface, and an antenna system comprising N antennas and an antenna driver module that sequentially drives the antenna system in a plurality of transverse modes of the antenna system to heat selected portions of the microwave absorbing surface to regenerate the PM filter, where N is an integer greater than one. The transverse modes may include transverse electric (TE) and/or transverse magnetic (TM) modes.

  10. What Protects the Core When the Thiolated Gold Cluster is Extremely Small?

    SciTech Connect (OSTI)

    Jiang, Deen [ORNL; Chen, Wei [University of Puerto Rico; Whetten, Robert L [Georgia Institute of Technology; Chen, Zhongfang [University of Georgia, Athens, GA

    2009-01-01

    The title question is motivated by the fact that extremely small thiolated-gold clusters such as Au{sub 20}(SR){sub 16} have been isolated, but their undetermined structures cannot be fully rationalized by the present knowledge derived from single-crystal structures of larger clusters. One needs to go beyond the linear monomer (RSAuSR) and V-shaped dimer (RSAuSRAuSR) motifs that were found to protect larger clusters. We hypothesize that the U-shaped trimer motif (RSAuSRAuSRAuSR) is required to protect the core of some extremely small thiolated-gold clusters, which have about 20 or fewer Au atoms. We test this hypothesis by proposing structural models for Au{sub 10}(SR){sub 8} based on two trimer motifs protecting a tetrahedral Au{sub 4} core and for Au{sub 20}(SR){sub 16} based on four trimer motifs protecting an Au{sub 8} core.

  11. Antenna Splitting Functions for Massive Particles

    SciTech Connect (OSTI)

    Larkoski, Andrew J.; Peskin, Michael E.; /SLAC

    2011-06-22

    An antenna shower is a parton shower in which the basic move is a color-coherent 2 {yields} 3 parton splitting process. In this paper, we give compact forms for the spin-dependent antenna splitting functions involving massive partons of spin 0 and spin 1/2. We hope that this formalism we have presented will be useful in describing the QCD dynamics of the top quark and other heavy particles at LHC.

  12. Unicast Multi-antenna Relay Beamforming with Per-Antenna Power Control: Optimization and Duality

    E-Print Network [OSTI]

    Liang, Ben

    is with Department of Electrical and Computer Engineering, University of Toronto, Ontario, Canada. Email: liang amplify-and-forward multi-antenna re- laying between a single pair of source and destination under relay at the source and destination, respectively, we first focus on the equivalent system with single-antenna source

  13. GOLD: The Genomes Online Database

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Kyrpides, Nikos; Liolios, Dinos; Chen, Amy; Tavernarakis, Nektarios; Hugenholtz, Philip; Markowitz, Victor; Bernal, Alex

    Since its inception in 1997, GOLD has continuously monitored genome sequencing projects worldwide and has provided the community with a unique centralized resource that integrates diverse information related to Archaea, Bacteria, Eukaryotic and more recently Metagenomic sequencing projects. As of September 2007, GOLD recorded 639 completed genome projects. These projects have their complete sequence deposited into the public archival sequence databases such as GenBank EMBL,and DDBJ. From the total of 639 complete and published genome projects as of 9/2007, 527 were bacterial, 47 were archaeal and 65 were eukaryotic. In addition to the complete projects, there were 2158 ongoing sequencing projects. 1328 of those were bacterial, 59 archaeal and 771 eukaryotic projects. Two types of metadata are provided by GOLD: (i) project metadata and (ii) organism/environment metadata. GOLD CARD pages for every project are available from the link of every GOLD_STAMP ID. The information in every one of these pages is organized into three tables: (a) Organism information, (b) Genome project information and (c) External links. [The Genomes On Line Database (GOLD) in 2007: Status of genomic and metagenomic projects and their associated metadata, Konstantinos Liolios, Konstantinos Mavromatis, Nektarios Tavernarakis and Nikos C. Kyrpides, Nucleic Acids Research Advance Access published online on November 2, 2007, Nucleic Acids Research, doi:10.1093/nar/gkm884]

    The basic tables in the GOLD database that can be browsed or searched include the following information:

    • Gold Stamp ID
    • Organism name
    • Domain
    • Links to information sources
    • Size and link to a map, when available
    • Chromosome number, Plas number, and GC content
    • A link for downloading the actual genome data
    • Institution that did the sequencing
    • Funding source
    • Database where information resides
    • Publication status and information

    (Specialized Interface)

  14. Practical Multi-antenna Spatial Reuse in Sriram Lakshmanan1

    E-Print Network [OSTI]

    Sivakumar, Raghupathy

    Practical Multi-antenna Spatial Reuse in WLANs Sriram Lakshmanan1 , Karthik Sundaresan2 , Mohammad suppression. #12;2 Sriram Lakshmanan et al. Although smart antennas have been shown to significantly improve

  15. Adaptive array antenna design for wireless communication systems 

    E-Print Network [OSTI]

    Noordin, Nurul Hazlina

    2013-11-28

    Adaptive array antennas use has been limited to non-commercial applications due to their high cost and hardware complexity. The implementation cost of adaptive array antennas can be kept to a minimum by using cost effective ...

  16. Lower Hybrid antennas for nuclear fusion experiments

    E-Print Network [OSTI]

    Hillairet, Julien; Bae, Young-Soon; Bai, X; Balorin, C; Baranov, Y; Basiuk, V; Bécoulet, A; Belo, J; Berger-By, G; Brémond, S; Castaldo, C; Ceccuzzi, S; Cesario, R; Corbel, E; Courtois, X; Decker, J; Delmas, E; Delpech, L; Ding, X; Douai, D; Ekedahl, A; Goletto, C; Goniche, M; Guilhem, D; Hertout, P; Imbeaux, F; Litaudon, X; Magne, R; Mailloux, J; Mazon, D; Mirizzi, F; Mollard, P; Moreau, P; Oosako, T; Petrzilka, V; Peysson, Y; Poli, S; Preynas, M; Prou, M; Saint-Laurent, F; Samaille, F; Saoutic, B

    2015-01-01

    The nuclear fusion research goal is to demonstrate the feasibility of fusion power for peaceful purposes. In order to achieve the conditions similar to those expected in an electricity-generating fusion power plant, plasmas with a temperature of several hundreds of millions of degrees must be generated and sustained for long periods. For this purpose, RF antennas delivering multi-megawatts of power to magnetized confined plasma are commonly used in experimental tokamaks. In the gigahertz range of frequencies, high power phased arrays known as "Lower Hybrid" (LH) antennas are used to extend the plasma duration. This paper reviews some of the technological aspects of the LH antennas used in the Tore Supra tokamak and presents the current design of a proposed 20 MW LH system for the international experiment ITER.

  17. Radar antenna pointing for optimized signal to noise ratio.

    SciTech Connect (OSTI)

    Doerry, Armin Walter; Marquette, Brandeis

    2013-01-01

    The Signal-to-Noise Ratio (SNR) of a radar echo signal will vary across a range swath, due to spherical wavefront spreading, atmospheric attenuation, and antenna beam illumination. The antenna beam illumination will depend on antenna pointing. Calculations of geometry are complicated by the curved earth, and atmospheric refraction. This report investigates optimizing antenna pointing to maximize the minimum SNR across the range swath.

  18. Coherent optical monolithic phased-array antenna steering system

    DOE Patents [OSTI]

    Hietala, Vincent M. (Placitas, NM); Kravitz, Stanley H. (Placitas, NM); Vawter, Gregory A. (Albuquerque, NM)

    1994-01-01

    An optical-based RF beam steering system for phased-array antennas comprising a photonic integrated circuit (PIC). The system is based on optical heterodyning employed to produce microwave phase shifting by a monolithic PIC constructed entirely of passive components. Microwave power and control signal distribution to the antenna is accomplished by optical fiber, permitting physical separation of the PIC and its control functions from the antenna. The system reduces size, weight, complexity, and cost of phased-array antenna systems.

  19. Microwave fidelity studies by varying antenna coupling

    E-Print Network [OSTI]

    B. Köber; U. Kuhl; H. -J. Stöckmann; T. Gorin; D. V. Savin; T. H. Seligman

    2010-09-16

    The fidelity decay in a microwave billiard is considered, where the coupling to an attached antenna is varied. The resulting quantity, coupling fidelity, is experimentally studied for three different terminators of the varied antenna: a hard wall reflection, an open wall reflection, and a 50 Ohm load, corresponding to a totally open channel. The model description in terms of an effective Hamiltonian with a complex coupling constant is given. Quantitative agreement is found with the theory obtained from a modified VWZ approach [Verbaarschot et al, Phys. Rep. 129, 367 (1985)].

  20. MEMS-reconfigurable metamaterials and antenna applications

    E-Print Network [OSTI]

    Debogovic, Tomislav

    2014-01-01

    This paper reviews some of our contributions to reconfigurable metamaterials, where dynamic control is enabled by micro-electro-mechanical systems (MEMS) technology. First, we show reconfigurable composite right/left handed transmission lines (CRLH-TLs) having state of the art phase velocity variation and loss, thereby enabling efficient reconfigurable phase shifters and leaky-wave antennas (LWA). Second, we present very low loss metasurface designs with reconfigurable reflection properties, applicable in reflectarrays and partially reflective surface (PRS) antennas. All the presented devices have been fabricated and experimentally validated. They operate in X- and Ku-bands.

  1. Catalytic Role of Gold in Gold-Based Catalysts: A Density Functional Theory Study on the CO Oxidation on Gold

    E-Print Network [OSTI]

    Alavi, Ali

    Catalytic Role of Gold in Gold-Based Catalysts: A Density Functional Theory Study on the CO Oxidation on Gold Zhi-Pan Liu and P. Hu* Contribution from the School of Chemistry, The Queen's Uni years, being regarded as a new generation of catalysts due to their unusually high catalytic performance

  2. Fabrication and optical characterization of nano-hole arrays in gold and gold/palladium films on glass

    E-Print Network [OSTI]

    van Vliet, Lucas J.

    Fabrication and optical characterization of nano-hole arrays in gold and gold/palladium films in a 200-nm thick layer of gold (Au), palladium (Pd), and gold/palladium (Au/Pd ¼ 60/40) alloy on glass

  3. Control of blood clotting using gold nanorods

    E-Print Network [OSTI]

    De Puig Guixé, Helena

    2013-01-01

    We have developed a method to externally control blood clotting using gold nanoparticles. Gold nanorods (NRs) have unique size and shape-dependent optical properties that can be used for externally controlled release of ...

  4. ECE 484 Antennas & Propagation Catalog Description: Introduction to antennas and radiowave propagation.

    E-Print Network [OSTI]

    of electromagnetic radiation: Maxwell's equations, potential functions, wave equation, retarded potential, short current element, near and far fields, Poynting's theorem · Basic antenna parameters: radiated power · Design of matching and feeding networks: quarter-wave transformer, series section transformer, stub

  5. A CARBON METER FOR OPTIMISATION OF GOLD

    E-Print Network [OSTI]

    Mucina, Ladislav

    A CARBON METER FOR OPTIMISATION OF GOLD EXTRACTION IP COMMERCIALISATION Tom Hammond Business of technology The Carbon-in-Pulp (CIP) process is used as the primary gold extraction method in gold mines around the world. An observation that activated carbon added to the circuit is not well monitored

  6. Glass antenna for RF-ion source operation

    DOE Patents [OSTI]

    Leung, Ka Ngo (Hercules, CA); Lee, Yung-Hee Yvette (Berkeley, CA); Perkins, Luke T. (Plainsboro, NJ)

    2000-01-01

    An antenna comprises a plurality of small diameter conductive wires disposed in a dielectric tube. The number and dimensions of the conductive wires is selected to improve the RF resistance of the antenna while also facilitating a reduction in thermal gradients that may create thermal stresses on the dielectric tube. The antenna may be mounted in a vacuum system using a low-stress antenna assembly that cushions and protects the dielectric tube from shock and mechanical vibration while also permitting convenient electrical and coolant connections to the antenna.

  7. NBody Simulations of the Antennae Chris Power

    E-Print Network [OSTI]

    Hibbard, John

    N­Body Simulations of the Antennae Chris Power 10th September, 1999 Abstract Collisions between by tidal forces may be responsible. Thus, whilst being a subject that stimulated much debate and Tails, the Toomres presented the a basic recipe for bridge and tail building based on the tidal

  8. ANTENNA-COUPLED LIGHT-MATTER INTERACTIONS

    SciTech Connect (OSTI)

    NOVOTNY, LUKAS

    2014-01-10

    This project is focused on antenna-coupled photon emission from single quantum emitters. The properties of optical antennas are tailored to control different photophysical parameters, such as the excited state lifetime, the saturation intensity, and the quantum yield [3]. Using a single molecule coupled to an optical antenna whose position and properties can be controllably adjusted we established a detailed and quantitative understanding of light-matter interactions in nanoscale environments. We have studied various quantum emitters: single molecules [11], quantum dots [7], rareearth ions [2], and NV centers in diamond [19]. We have systematically studied the interaction of these emitters with optical antennas. The overall objective was to establish a high-level of control over the light-matter interaction. In order to eliminate the coupling to the environment, we have taken a step further and explored the possibility of levitating the quantum emitter in high vacuum. What started as a side-project soon became a main activity in our research program and led us to the demonstration of vacuum trapping and cooling of a nanoscale particle [14].

  9. Semiconductor Nanowire Optical Antenna Solar Absorbers

    E-Print Network [OSTI]

    Fan, Shanhui

    cost reductions in the manufacturing of solar mod- ules.1 Moreover, it is essential to identify newSemiconductor Nanowire Optical Antenna Solar Absorbers Linyou Cao, Pengyu Fan, Alok P. Vasudev the absorption for solar radiation by 25% while utilizing less than half of the semiconductor material (250

  10. Low cost impulse compatible wideband antenna

    DOE Patents [OSTI]

    Rosenbury, Erwin T. (Livermore, CA); Burke, Gerald J. (Livermore, CA); Nelson, Scott D. (Tracy, CA); Stever, Robert D. (Lathrop, CA); Governo, George K. (Livermore, CA); Mullenhoff, Donald J. (Livermore, CA)

    2002-01-01

    An antenna apparatus and method for building the antenna is disclosed. Impulse signals travel through a feed point of the antenna with respect to a ground plane. A geometric fin structure is connected to the feed point, and through a termination resistance to the ground plane. A geometric ridge structure connected to the ground is positioned with respect to the fin in order to receive and radiate electromagnetic energy from the impulse signal at a predetermined impedance and over a predetermined set of frequencies. The fin and ridge can be either a wire or a planar surface. The fin and ridge may be disposed within a radiation cavity such as a horn. The radiation cavity is constructed of stamped and etched metal sheets bent and then soldered together. The fin and ridge are also formed from metal sheets or wires. The fin is attached to the feed point and then to the cavity through a termination resistance. The ridge is attached to the cavity and disposed with respect to the fin in order to achieve a particular set of antenna characteristics.

  11. SINGLE AND MULTIPLE ANTENNA COMMUNICATION SYSTEMS: PERFORMANCE

    E-Print Network [OSTI]

    Wehlau, David

    ), the Ontario Premier's Research Excellence Award (PREA), the Department of Electrical and Computer EngineeringSINGLE AND MULTIPLE ANTENNA COMMUNICATION SYSTEMS: PERFORMANCE ANALYSIS AND JOINT SOURCE-CHANNEL CODING by Firouz Behnamfar A thesis submitted to the Department of Electrical and Computer Engineering

  12. Antenna factorization in strongly ordered limits

    SciTech Connect (OSTI)

    Kosower, David A.

    2005-02-15

    When energies or angles of gluons emitted in a gauge-theory process are small and strongly ordered, the emission factorizes in a simple way to all orders in perturbation theory. I show how to unify the various strongly ordered soft, mixed soft-collinear, and collinear limits using antenna factorization amplitudes, which are generalizations of the Catani-Seymour dipole factorization function.

  13. Two antenna, two pass interferometric synthetic aperture radar

    DOE Patents [OSTI]

    Martinez, Ana; Doerry, Armin W.; Bickel, Douglas L.

    2005-06-28

    A multi-antenna, multi-pass IFSAR mode utilizing data driven alignment of multiple independent passes can combine the scaling accuracy of a two-antenna, one-pass IFSAR mode with the height-noise performance of a one-antenna, two-pass IFSAR mode. A two-antenna, two-pass IFSAR mode can accurately estimate the larger antenna baseline from the data itself and reduce height-noise, allowing for more accurate information about target ground position locations and heights. The two-antenna, two-pass IFSAR mode can use coarser IFSAR data to estimate the larger antenna baseline. Multi-pass IFSAR can be extended to more than two (2) passes, thereby allowing true three-dimensional radar imaging from stand-off aircraft and satellite platforms.

  14. Study Guide for Gilbane Gold

    E-Print Network [OSTI]

    Chen, Xinzhong

    Gold" is the name given to dried sludge from the Gilbane wastewater treatment plant. It is sold the amount of water, thus still meeting the existing city standards. The result, however, is that Gilbane to changing the test standards because that would require additional investment in wastewater treatment

  15. Assessment of a field-aligned ICRF antenna

    SciTech Connect (OSTI)

    Wukitch, S. J.; Brunner, D.; Ennever, P.; Garrett, M. L.; Hubbard, A.; Labombard, B.; Lau, C.; Lin, Y.; Lipschultz, B.; Miller, D.; Ochoukov, R.; Porkolab, M.; Reinke, M. L.; Terry, J. L.

    2014-02-12

    Impurity contamination and localized heat loads associated with ion cyclotron range of frequency (ICRF) antenna operation are among the most challenging issues for ICRF utilization.. Another challenge is maintaining maximum coupled power through plasma variations including edge localized modes (ELMs) and confinement transitions. Here, we report on an experimental assessment of a field aligned (FA) antenna with respect to impurity contamination, impurity sources, RF enhanced heat flux and load tolerance. In addition, we compare the modification of the scrape of layer (SOL) plasma potential of the FA antenna to a conventional, toroidally aligned (TA) antenna, in order to explore the underlying physics governing impurity contamination linked to ICRF heating. The FA antenna is a 4-strap ICRF antenna where the current straps and antenna enclosure sides are perpendicular to and the Faraday screen rods are parallel to the total magnetic field. In principle, alignment with respect to the total magnetic field minimizes integrated E? (electric field along a magnetic field line) via symmetry. Consistent with expectations, we observed that the impurity contamination and impurity source at the FA antenna are reduced compared to the TA antenna. In both L and H-mode discharges, the radiated power is 20–30% lower for a FA-antenna heated discharge than a discharge heated with the TA-antennas. Further we observe that the fraction of RF energy deposited upon the antenna is less than 0.4 % of the total injected RF energy in dipole phasing. The total deposited energy increases significantly when the FA antenna is operated in monopole phasing. The FA antenna also exhibits an unexpected load tolerance for ELMs and confinement transitions compared to the TA antennas. However, inconsistent with expectations, we observe RF induced plasma potentials to be nearly identical for FA and TA antennas when operated in dipole phasing. In monopole phasing, the FA antenna has the highest plasma potentials and poor heating efficiency despite calculations indicating low integrated E?. In mode conversion heating scenario, no core waves were detected in the plasma core indicating poor wave penetration. For monopole phasing, simulations suggest the antenna spectrum is peaked at very short wavelength and full wave simulations show the short wavelength has poor wave penetration to the plasma core.

  16. New Concepts For High Power ICRF Antennas

    SciTech Connect (OSTI)

    Bosia, G. [Department of Physics University of Turin (Italy)

    2011-12-23

    This paper presents new concepts for Ion Cyclotron Heating antennas based on cascaded sequences of tuned radiating structures. It is shown that, in large arrays, such as the ones proposed for fusion reactors applications, these schemes offer, in principle, a number of desirable features, such as operation at power density significantly higher than currently adopted systems, at equal maximum voltage and array geometry, simple mechanical layout, suitable for water cooling, a compact impedance tuning system, passive decoupling of the array elements, single ended or balanced feed from two power sources. The antenna layout also allows the remote, real time measurement of the complex impedance of the radiating elements and the detection, location, and measurement of the complex admittance of arcs occurring anywhere in the structure, as discussed in [1].

  17. Biomolecular Assembly of Gold Nanocrystals

    SciTech Connect (OSTI)

    Micheel, Christine Marya

    2005-05-20

    Over the past ten years, methods have been developed to construct discrete nanostructures using nanocrystals and biomolecules. While these frequently consist of gold nanocrystals and DNA, semiconductor nanocrystals as well as antibodies and enzymes have also been used. One example of discrete nanostructures is dimers of gold nanocrystals linked together with complementary DNA. This type of nanostructure is also known as a nanocrystal molecule. Discrete nanostructures of this kind have a number of potential applications, from highly parallel self-assembly of electronics components and rapid read-out of DNA computations to biological imaging and a variety of bioassays. My research focused in three main areas. The first area, the refinement of electrophoresis as a purification and characterization method, included application of agarose gel electrophoresis to the purification of discrete gold nanocrystal/DNA conjugates and nanocrystal molecules, as well as development of a more detailed understanding of the hydrodynamic behavior of these materials in gels. The second area, the development of methods for quantitative analysis of transmission electron microscope data, used computer programs written to find pair correlations as well as higher order correlations. With these programs, it is possible to reliably locate and measure nanocrystal molecules in TEM images. The final area of research explored the use of DNA ligase in the formation of nanocrystal molecules. Synthesis of dimers of gold particles linked with a single strand of DNA possible through the use of DNA ligase opens the possibility for amplification of nanostructures in a manner similar to polymerase chain reaction. These three areas are discussed in the context of the work in the Alivisatos group, as well as the field as a whole.

  18. Antenna with distributed strip and integrated electronic components

    DOE Patents [OSTI]

    Rodenbeck, Christopher T. (Albuquerque, NM); Payne, Jason A. (Albuquerque, NM); Ottesen, Cory W. (Albuquerque, NM)

    2008-08-05

    An antenna comprises electrical conductors arranged to form a radiating element including a folded line configuration and a distributed strip configuration, where the radiating element can be in proximity to a ground conductor and/or arranged as a dipole. Embodiments of the antenna include conductor patterns formed on a printed wiring board, having a ground plane, spacedly adjacent to and coplanar with the radiating element. An antenna can comprise a distributed strip patterned on a printed wiring board, integrated with electronic components mounted on top of or below the distributed strip, and substantially within the extents of the distributed strip. Mounting of electronic components on top of or below the distributed strip has little effect on the performance of the antenna, and allows for realizing the combination of the antenna and integrated components in a compact form. An embodiment of the invention comprises an antenna including a distributed strip, integrated with a battery mounted on the distributed strip.

  19. GOLD--2001 33.1 By Earle B. Amey

    E-Print Network [OSTI]

    GOLD--2001 33.1 GOLD By Earle B. Amey Domestic survey data and tables were prepared by Mahbood, international data coordinator. Domestic gold mine production in 2001 fell to its lowest level since 1996.S. gold mine production was about $2.9 billion in 2001. Domestic gold exploration activity dropped

  20. Combined ICR heating antenna for ion separation systems

    SciTech Connect (OSTI)

    Timofeev, A. V. [Russian Research Centre Kurchatov Institute (Russian Federation)

    2011-01-15

    A combination of one- and two-wave antennas (one and two turns of conductors around a plasma cylinder, respectively) is proposed. This combined antenna localizes an RF field within itself. It is shown that spent nuclear fuel processing systems based on ICR heating of nuclear ash by such a combined antenna have high productivity. A theory of the RF field excitation in ICR ion separation systems is presented in a simple and compact form.

  1. Electronically tunable active antenna using microstrip annular ring 

    E-Print Network [OSTI]

    Miller, Richard Earl

    1989-01-01

    device was placed into the ring and the antenna characteristics were found and compared to the conventional ring. A varactor diode was also used to electronically tune the ring. Finally, two Gunn diodes were placed into a. single annular ring.... The active annular ring antenna exhibited 70% efEciency in power generation when compared to the Gunn diode in an optimized waveguide. The annular ring antenna, displayed a. poor power radiation pattern. TABLE OF CONTENTS CHAPTER Ps. ge I INTRODUCTION...

  2. Magneto-optical manipulation of surface plasmons in gold/ferromagnetic/gold multilayer films

    E-Print Network [OSTI]

    Temnov, Vasily V.

    Modulation of the surface plasmon wave vector in composite gold/cobalt/gold multilayer films due to periodic magnetization switching in cobalt is observed with a tilted slit-groove microinterferometer.

  3. A new radiation stripline ICRF antenna design for EAST Tokamak

    SciTech Connect (OSTI)

    Qin, C. M.; Zhao, Y. P.; Wan, B. N.; Li, J.; Zhang, X. J.; Yang, Q. X.; Yuan, S. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Braun, F. [Max-Planck Institute for Plasma Physics, D-85748, Garching (Germany); Notedame, J.-M. [Max-Planck Institute for Plasma Physics, D-85748, Garching, Germany and University of Gent (Belgium); Kasahara, H. [National Institute for Fusion Science, Toki (Japan); Collaboration: ICRF Team on EAST

    2014-02-12

    A new type of toroidal long Radiation Stripline Antenna (RSA) is presented, which can effectively improve antenna radiation, leading in reduction of max voltage on transmission line and decrease of the sensitivity to ELM's of the ICRF system at some frequencies. Based on the new concept, a 4-straps RSA is proposed for EAST device. Using 3-D computing simulator code (HFSS), RF current distribution, S-parameters and electromagnetic field distribution on and near the RSA ICRF antenna are analyzed and compared with present ICRF antenna on EAST.

  4. Antenna-coupled microcavities for enhanced infrared photo-detection

    SciTech Connect (OSTI)

    Nga Chen, Yuk; Todorov, Yanko Askenazi, Benjamin; Vasanelli, Angela; Sirtori, Carlo; Biasiol, Giorgio; Colombelli, Raffaele

    2014-01-20

    We demonstrate mid-infrared detectors embedded into an array of double-metal nano-antennas. The antennas act as microcavities that squeeze the electric field into thin semiconductor layers, thus enhancing the detector responsivity. Furthermore, thanks to the ability of the antennas to gather photons from an area larger than the device's physical dimensions, the dark current is reduced without hindering the photo-generation rate. In these devices, the background-limited performance is improved with a consequent increase of the operating temperature. Our results illustrate how the antenna-coupled microcavity concept can be applied to enhance the performances of infrared opto-electronic devices.

  5. Shape and Material Optimization for Bandwidth Improvement of Printed Antennas on High Contrast Substrates

    E-Print Network [OSTI]

    Sendur, Gullu Kiziltas

    Shape and Material Optimization for Bandwidth Improvement of Printed Antennas on High Contrast shape and material optimization technique is proposed to develop a miniature patch antenna having a dielectric constant of r =100. Keywords : Topology Optimization, Material Design, Patch Antenna

  6. Analytical Techniques and Operational Perspectives for a Spherical Inverted-F Antenna 

    E-Print Network [OSTI]

    Rolando, David Lee

    2012-02-14

    The spherical inverted-F antenna (SIFA) is a relatively new conformal antenna design that consists of a microstrip patch resonator on a spherical ground. The SIFA resembles a planar inverted-F antenna (PIFA) that has ...

  7. Electromigration of Electroplated Gold Interconnects Steve Kilgore, *

    E-Print Network [OSTI]

    Schroder, Dieter K.

    Electromigration of Electroplated Gold Interconnects Steve Kilgore, * Craig Gaw, * Haldane Henry Tempe, AZ 85287, U.S.A. ABSTRACT Electromigration tests were performed on passivated electroplated Au

  8. Gold catalyst Styrene Benzaldehyde Styrene oxide Acetophenone

    E-Print Network [OSTI]

    Rouyer, Francois

    O O O + + O2 Gold catalyst Styrene Benzaldehyde Styrene oxide Acetophenone studies. However styrene. The reaction chiefly yielded benzaldehyde, with smaller amounts of styrene oxide and acetophenone

  9. BPA Headquarters Now “Gold Certified” for Sustainability

    Broader source: Energy.gov [DOE]

    BPA recently became the first federal agency in Portland, Oregon, to achieve the city's Sustainability at Work Gold Certification for sustainability efforts at its headquarters building.

  10. An overview of global gold market and gold price forecasting Shahriar Shafiee a,n

    E-Print Network [OSTI]

    Boisvert, Jeff

    on monthly historical data of nominal gold price. & 2010 Elsevier Ltd. All rights reserved. Introduction classification: E31 O13 Q32 Keywords: Historical gold market Forecasting mineral prices Long-term trend reverting and the price of gold is relatively higher than its historical trend. For mining companies to mitigate risk

  11. Water and Gold: A Promising Mix for Future Batteries

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Water and Gold: A Promising Mix for Future Batteries Water and Gold: A Promising Mix for Future Batteries Berkeley Lab Study Reveals Molecular Structure of Water at Gold Electrodes...

  12. NREL: Awards and Honors - DRWiN(tm) Electronically Scanning Antenna

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and customers. As such, this antenna could help revolutionize commercial broadband wireless communications. Unlike traditional commercial antennas, which are built to respond to...

  13. Structure Revealing H/D Exchange with Co-Adsorbed Hydrogen and Water on Gold

    E-Print Network [OSTI]

    Henkelman, Graeme

    oxide-gold interface can readily dissociate hydrogen,10 and hydrogen spillover onto the gold results

  14. 666 IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS, VOL. 10, 2011 Compact Coplanar Waveguide Spiral Antenna With

    E-Print Network [OSTI]

    Bornemann, Jens

    of the radiated power and results in a unidi- rectional radiation pattern, which is desirable in many applica- fied that the proposed spiral antenna has stable radiation pattern, and its axial ratio is less than 3 are with the Poly-Grames Research Center and Center for Radiofrequency Electronics Research of Quebec (CREER

  15. Energy-Efficient Antenna Selection and Power Allocation for Large-Scale Multiple Antenna

    E-Print Network [OSTI]

    ) sector has been estimated to represent about 2 percent of the global CO2 emissions [1], and 1.8 percent reduce CO2 emissions [5]. On the other hand, large-scale multiple antenna systems which employ hundreds of the total world electricity consumption [2]. The mobile network operational expenditure (OPEX

  16. The Gold-Exchange Standard and the Great Depression

    E-Print Network [OSTI]

    Eichengreen, Barry

    1988-01-01

    The first posits a maldistribution of gold, blaming Franceto be unsatisfactory; a maldistribution to which is to beThe first posits a maldistribution of gold, blaming France

  17. Testing a Prototype Blade Antenna at the LWDA Site

    E-Print Network [OSTI]

    Ellingson, Steven W.

    1 Testing a Prototype Blade Antenna at the LWDA Site Nagini Paravastu, William Erickson, Ylva summarizes the testing done on a prototype LWDA blade antenna at the VLA on August 30, 2005 ­ September 1, 2005. As the LWDA project transitions from the planning and design phases to the construction phase

  18. Testing a Prototype Blade Antenna at the LWDA-1 Site

    E-Print Network [OSTI]

    Ellingson, Steven W.

    1 Testing a Prototype Blade Antenna at the LWDA-1 Site Nagini Paravastu, William Erickson, Ylva the testing done on a prototype LWDA blade antenna at the VLA on August 30, 2005 ­ September 1, 2005. As the LWDA project transitions from the planning and design phases to the construction phase, field

  19. HHFW (High Harmonic Fast Wave) Eddy Current Analysis for Antenna

    E-Print Network [OSTI]

    Princeton Plasma Physics Laboratory

    1 NSTX HHFW (High Harmonic Fast Wave) Eddy Current Analysis for Antenna NSTX-CALC-24-03-01 June 1 performed.) The model was first built for NSTX to verify the eddy current effect on antenna during plasma force of the induced eddy current in the components. The force data was transferred to the structural

  20. CIRCULARLY POLARIZED ANTENNA ON SOI FOR THE 60 GHZ BAND

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    of the primary criteria for evaluating the quality of the antenna; Improper feed, higher order band radiation integrated on SOI. In the first part, we describe the spiral antenna theory in order to have good radiation. The feeding structure is composed of a transition between radiofrequency coplanar waveguide feed, coplanar

  1. Optical Antennas Palash Bharadwaj, Bradley Deutsch, and Lukas Novotny*

    E-Print Network [OSTI]

    Novotny, Lukas

    is to convert the energy of free propagating radiation to localized energy, and vice versa. Optical antennas exOptical Antennas Palash Bharadwaj, Bradley Deutsch, and Lukas Novotny* Institute of Optics author: www.nano-optics.org Received March 12, 2009; revised July 4, 2009; accepted July 8, 2009; posted

  2. NO. IREV. NO. ALSEPArray E Antenna Aiming Mechanism IATM-1031 ~

    E-Print Network [OSTI]

    Rathbun, Julie A.

    NO. IREV. NO. ALSEPArray E Antenna Aiming Mechanism IATM-1031 ~ Design Verification Test Results reports the results of Design Verification Testing on the Array E Antenna Aiming Mechanism. Prepared by: ~.~R. Sigler Project Engineer Approved b~~~ ;:gopuiS: pervisor Mechanical Design /'7/~'?dApproved by

  3. Wireless Antennas -Making Wireless Communications Perform Like Wireline Communications

    E-Print Network [OSTI]

    Hua, Yingbo

    1 Wireless Antennas - Making Wireless Communications Perform Like Wireline Communications Yingbo first provide an overview of some of the latest developments in wireless communications using multiple of wireless antennas or wireless relays that are distributed between a source and a destination. We propose

  4. Effective Wavelength Scaling for Optical Antennas Lukas Novotny*

    E-Print Network [OSTI]

    Novotny, Lukas

    of Rochester, Rochester, New York, USA (Received 27 March 2007; published 27 June 2007) In antenna theory at optical frequencies where metals behave as strongly coupled plasmas. In this Letter we show that antenna designs can be transferred to the optical frequency regime by replacing by a linearly scaled effective

  5. Gold-nickel-titanium brazing alloy

    DOE Patents [OSTI]

    Mizuhara, Howard

    1995-01-03

    A brazing alloy in accordance with this invention has the following composition, by weight: 91 to 99 gold, 0.5 to 7% nickel; 0.10 to 2% titanium. Alternatively, with palladium present, the composition is as follows, by weight: 83 to 96% gold; 3 to 10% palladium; 0.5 to 5% nickel; 0.10 to 2% titanium.

  6. Gold-nickel-titanium brazing alloy

    DOE Patents [OSTI]

    Mizuhara, Howard (Hillsborough, CA)

    1990-07-03

    A brazing alloy in accordance with this invention has the following composition, by weight: 91 to 99% gold, 0.5 to 7% nickel; 0.10 to 2% titanium. Alternatively, with palladium present, the composition is as follows, by weight: 83 to 96% gold; 3 to 10% palladium; 0.5 to 5% nickel; 0.10 to 2% titanium.

  7. IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS, VOL. 4, 2005 9 A Broadband Interior Antenna of Planar Monopole

    E-Print Network [OSTI]

    Park, Seong-Ook

    ], and thickening the radiator. In addition, it is important to con- sider the mobile phone case and battery because a novel internal antenna of the planar monopole type for application in mobile phones. The band- width--A novel internal antenna of planar monopole type is presented for broadband applications. The proposed

  8. 510 IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS, VOL. 10, 2011 A Scalable Solar Antenna for Autonomous Integrated

    E-Print Network [OSTI]

    Tentzeris, Manos

    that can be integrated underneath a solar panel is presented. The topology alleviates the effect of solar--3-D RF modules, autonomous modules, omni- directional antenna, solar antenna, solar panel, wireless consumption of every individual node [11]. Currently, solar panels harvest the largest reported amount

  9. Antenna unit and radio base station therewith

    DOE Patents [OSTI]

    Kuwahara, Mikio; Doi, Nobukazu; Suzuki, Toshiro; Ishida, Yuji; Inoue, Takashi; Niida, Sumaru

    2007-04-10

    Phase and amplitude deviations, which are generated, for example, by cables connecting an array antenna of a CDMA base station and the base station, are calibrated in the baseband. The base station comprises: an antenna apparatus 1; couplers 2; an RF unit 3 that converts a receive signal to a baseband signal, converts a transmit signal to a radio frequency, and performs power control; an A/D converter 4 for converting a receive signal to a digital signal; a receive beam form unit 6 that multiplies the receive signal by semi-fixed weight; a despreader 7 for this signal input; a time-space demodulator 8 for demodulating user data; a despreader 9 for probe signal; a space modulator 14 for user data; a spreader 13 for user signal; a channel combiner 12; a Tx calibrater 11 for controlling calibration of a signal; a D/A converter 10; a unit 16 for calculation of correlation matrix for generating a probe signal used for controlling an Rx calibration system and a TX calibration system; a spreader 17 for probe signal; a power control unit 18; a D/A converter 19; an RF unit 20 for probe signal; an A/D converter 21 for signal from the couplers 2; and a despreader 22.

  10. Coal-gold agglomeration: an alternative separation process in gold recovery

    SciTech Connect (OSTI)

    Akcil, A.; Wu, X.Q.; Aksay, E.K. [Suleyman Demirel University, Isparta (Turkey). Dept. of Mining Engineering

    2009-07-01

    Considering the increasing environmental concerns and the potential for small gold deposits to be exploited in the future, the uses of environmentally friendly processes are essential. Recent developments point to the potential for greatly increased plant performance through a separation process that combines the cyanide and flotation processes. In addition, this kind of alternative treatment processes to the traditional gold recovery processes may reduce the environmental risks of present small-scale gold mining. Gold recovery processes that applied to different types of gold bearing ore deposits show that the type of deposits plays an important role for the selection of mineral processing technologies in the production of gold and other precious metals. In the last 25 years, different alternative processes have been investigated on gold deposits located in areas where environmental issues are a great concern. In 1988, gold particles were first recovered by successful pilot trial of coal-gold agglomeration (CGA) process in Australia. The current paper reviews the importance of CGA in the production of gold ore and identifies areas for further development work.

  11. Gel Electrophoresis of Gold-DNA Nanoconjugates

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Pellegrino, T.; Sperling, R. A.; Alivisatos, A. P.; Parak, W. J.

    2007-01-01

    Gold-DNA conjugates were investigated in detail by a comprehensive gel electrophoresis study based on 1200 gels. A controlled number of single-stranded DNA of different length was attached specifically via thiol-Au bonds to phosphine-stabilized colloidal gold nanoparticles. Alternatively, the surface of the gold particles was saturated with single stranded DNA of different length either specifically via thiol-Au bonds or by nonspecific adsorption. From the experimentally determined electrophoretic mobilities, estimates for the effective diameters of the gold-DNA conjugates were derived by applying two different data treatment approaches. The first method is based on making a calibration curve for the relation between effectivemore »diameters and mobilities with gold nanoparticles of known diameter. The second method is based on Ferguson analysis which uses gold nanoparticles of known diameter as reference database. Our study shows that effective diameters derived from gel electrophoresis measurements are affected with a high error bar as the determined values strongly depend on the method of evaluation, though relative changes in size upon binding of molecules can be detected with high precision. Furthermore, in this study, the specific attachment of DNA via gold-thiol bonds to Au nanoparticles is compared to nonspecific adsorption of DNA. Also, the maximum number of DNA molecules that can be bound per particle was determined.« less

  12. Antennas in the optical range will improve the efficiency of light-emitting devices.

    E-Print Network [OSTI]

    Novotny, Lukas

    Antennas in the optical range will improve the efficiency of light-emitting devices. The purpose of optical antennas is to convert the energy of free propagat- ing radiation to localized energy, and vice versa. Although this is similar to what radio wave and microwave antennas do, optical antennas exploit

  13. FRESNEL-ZONE MEASUREMENT AND ANALYSIS OF A DUAL-POLARIZED METEOROLOGICAL RADAR ANTENNA

    E-Print Network [OSTI]

    Collings, Iain B.

    FRESNEL-ZONE MEASUREMENT AND ANALYSIS OF A DUAL- POLARIZED METEOROLOGICAL RADAR ANTENNA D.B. Hayman Fresnel-zone holographic technique was used to obtain the radiation pattern for the upgraded antenna in the measurement of this antenna and the analysis of the results. Keywords: Antenna measurements, Fresnel zone

  14. Analysis and Measurement of Multiple Antenna Systems for Fading Channel Prediction in Moving

    E-Print Network [OSTI]

    been proposed, where an antenna is placed in front of other antennas on the roof of the vehicle will experience mutual electromagnetic couplings. These may reduce the efficiency of the predictor antenna concept as CSI predictions for efficient communication with the receiver antenna. The temporal cross- correlation

  15. Conformal Antenna Array for Millimeter-Wave Communications: Performance Evaluation

    E-Print Network [OSTI]

    Semkin, V; Kyro, M; Kolmonen, V-M; Luxey, C; Ferrero, F; Devillers, F; Raisanen, A V

    2015-01-01

    In this paper, we study the influence of the radius of a cylindrical supporting structure on radiation properties of a conformal millimeter-wave antenna array. Bent antenna array structures on cylindrical surfaces may have important applications in future mobile devices. Small radii may be needed if the antenna is printed on the edges of mobile devices and in items which human beings are wearing, such as wrist watches, bracelets and rings. The antenna under study consists of four linear series-fed arrays of four patch elements and is operating at 58.8 GHz with linear polarization. The antenna array is fabricated on polytetrafluoroethylene substrate with thickness of 0.127 mm due to its good plasticity properties and low losses. Results for both planar and conformal antenna arrays show rather good agreement between simulation and measurements. The results show that conformal antenna structures allow achieving large angular coverage and may allow beam-steering implementations if switches are used to select betw...

  16. Colloidal-gold electrosensor measuring device

    DOE Patents [OSTI]

    Wegner, Steven (Chapel Hill, NC); Harpold, Michael A. (Durham, NC); McCaffrey, Terence M. (Durham, NC); Morris, Susan E. (Chapel Hill, NC); Wojciechowski, Marek (Cary, NC); Zhao, Junguo (Chapel Hill, NC); Henkens, Robert W. (Durham, NC); Naser, Najih (Durham, NC); O'Daly, John P. (Carrboro, NC)

    1995-01-01

    The present invention provides a new device for use in measuring lead levels in biological and environmental samples. Using square wave coulometry and colloidal gold particles impregnated on carbon electrodes, the present invention provides a rapid, reliable, portable and inexpensive means of detecting low lead levels. The colloidal gold modified electrodes have microelectrode array characteristics and produce significantly higher stripping detection signals for lead than are produced at bulk gold electrode surfaces. The method is effective in determining levels of lead down to at least 5 .mu.g/dL in blood samples as small as 10 .mu.L.

  17. Colloidal-gold electrosensor measuring device

    DOE Patents [OSTI]

    Wegner, S.; Harpold, M.A.; McCaffrey, T.M.; Morris, S.E.; Wojciechowski, M.; Zhao, J.; Henkens, R.W.; Naser, N.; O`Daly, J.P.

    1995-11-21

    The present invention provides a new device for use in measuring lead levels in biological and environmental samples. Using square wave coulometry and colloidal gold particles impregnated on carbon electrodes, the present invention provides a rapid, reliable, portable and inexpensive means of detecting low lead levels. The colloidal gold modified electrodes have microelectrode array characteristics and produce significantly higher stripping detection signals for lead than are produced at bulk gold electrode surfaces. The method is effective in determining levels of lead down to at least 5 {micro}g/dL in blood samples as small as 10 {micro}L. 9 figs.

  18. Method of making radio frequency ion source antenna and such antenna

    DOE Patents [OSTI]

    Ehlers, K.W.; Leung, K.N.

    1985-05-22

    In the method, the radio frequency (rf) antenna is made by providing a clean coil made of copper tubing or other metal conductor, which is coated with a tacky organic binder, and then with a powdered glass frit, as by sprinkling the frit uniformly over the binder. The coil is then heated internally in an inert gas atmosphere, preferably by passing an electrical heating current along the coil. Initially, the coil is internally heated to about 200/sup 0/C to boil off the water from the binder, and then to about 750 to 850/sup 0/C to melt the glass frit, while also burning off the organic binder. The melted frit forms a molten glass coating on the metal coil, which is then cooled to solidify the glass, so that the metal coil is covered with a thin continuous homogeneous impervious glass coating of substantially uniform thickness. The glass coating affords complete electrical insulation and complete dielectric protection for the metal coil of the rf antenna, to withstand voltage breakdown and to prevent sputtering, while also doubling the plasma generating efficiency of the rf antenna, when energized with RF power in the vacuum chamber of an ion source for a particle accelerator or the like. The glass frit preferably contains approximately 45% lead oxide.

  19. Image-line voltage controlled oscillators and grating antennas 

    E-Print Network [OSTI]

    Kirk, Alexander MacDonald

    1991-01-01

    Chair of Advisory Committee: Dr. Kai Chang A novel active antenna is proposed with an image-line construction. An image-line Gunn diode oscillator utilizing a cap resonator, for frequency stability, is the source module for the antenna. A varactor... is added to the source module for frequency tuning. Combining Gunn diode bias and varactor tuning, 2 percent electronic tuning bandwidth in the X-band has been achieved. The source module is an integral part of an image-line periodic grating antenna...

  20. Using Micro-Electro-Mechanical Systems (MEMS) as Small Antennas

    SciTech Connect (OSTI)

    Datskos, Panos G [ORNL; Lavrik, Nickolay V [ORNL; Tobin, Jacob D [ORNL; Bowland, Landon T [ORNL

    2012-01-01

    We describe the design, fabrication and characterization of simple micromechanical structures that are capable of sensing static electric time varying electromagnetic fields. Time varying electric field sensing is usually achieved using an electromagnetic antenna and a receiver. However, these antenna-based approaches do not exhibit high sensitivity over a broad frequency (or wavelength) range. An important aspect of the present work is that, in contrast to traditional antennas, the dimensions of these micromechanical oscillators can be much smaller than the wavelength of the electromagnetic wave. We characterized the fabricated micromechanical oscillators by measuring their responses to time varying electric and electromagnetic fields.

  1. A study of coupled dipole antennas in echelon 

    E-Print Network [OSTI]

    Patwari, Abdul Matin

    1961-01-01

    - )((4(&)/~ & P (()/4'~' '')3 " I G", (&+~?( ~~ ) ] Iqq --) 4i 6 f(Fo (t) t- Fi(()/fi t FP (()/Z2 4 ') ( Fo(f1~ & Fi (fl)/fl J Fs [(~)/fl +) ( I', tl)/a t &*I&i/a'i ) ( f', (4)/~t &*~&)/~'+ (37) Equation (37) is the general solution for the current...: 't 3 A&q + p~A~t = o /pl (7. a) 'g Ass +( Aag -- o /pa (7. b) The vector potential at the surface of each antenna consists of two components, 1) that due to the current in the antenna itself, 2) that due to the current in the parallel antenna...

  2. Femtosecond surface plasmon interferometry with gold nanostructures

    E-Print Network [OSTI]

    Temnov, Vasily V.

    We measure the ultrafast electron dynamics in gold via ultrafast surface plasmon interferometry. A new plasmonic microinterferometer with tilted slit-groove pair is used to unambiguously determine changes of real and ...

  3. Autonomous smart antenna systems for future mobile devices 

    E-Print Network [OSTI]

    Zhou, Wei

    2015-06-29

    Along with the current trend of wireless technology innovation, wideband, compact size, low-profile, lightweight and multiple functional antenna and array designs are becoming more attractive in many applications. ...

  4. Miniature Antenna Designs on Metamaterial Substrates Gullu Kiziltas

    E-Print Network [OSTI]

    Sendur, Gullu Kiziltas

    employing SLP for the optimization is introduced. The employed design method is the Solid Isotropic Material composition subject to antenna bandwidth enhancements. Keywords: Topology Optimization, Material Design, Patch and composite materials provides the opportunity to revolutionize traditional design optimization processes

  5. Infrared Antennas & Frequency Selective Surfaces Glenn D. Boreman

    E-Print Network [OSTI]

    Van Stryland, Eric

    ... Research focus: Extension of radiofrequency concepts to IR CREOL IR Systems Lab 1989 #12;Research Approach radiation. Incident radiation induces IR-frequency current waves to flow in the arms of the antenna

  6. The Planar Parabolic Optical Antenna David T. Schoen,,

    E-Print Network [OSTI]

    Polman, Albert

    on the wavelength scale. Significant progress has been made in scaling radiowave antennas to the nanoscale in a variety of important applications, such as photon sources,3 photo- detectors,4 sensors,5 and photovoltaics

  7. Multidisciplinary adaptive wireless communication systems: Reconfigurable MEMS integrated antennas &

    E-Print Network [OSTI]

    De Flaviis, Franco

    Multidisciplinary adaptive wireless communication systems: Reconfigurable MEMS integrated antennas of California, Irvine, USA Wireless communication systems with reconfigurability capabilities that can for the next generation communication scenarios. A communication system capable of changing its output

  8. Ultra-wideband horn antenna with abrupt radiator

    DOE Patents [OSTI]

    McEwan, Thomas E. (Livermore, CA)

    1998-01-01

    An ultra-wideband horn antenna transmits and receives impulse waveforms for short-range radars and impulse time-of flight systems. The antenna reduces or eliminates various sources of close-in radar clutter, including pulse dispersion and ringing, sidelobe clutter, and feedline coupling into the antenna. Dispersion is minimized with an abrupt launch point radiator element; sidelobe and feedline coupling are minimized by recessing the radiator into a metallic horn. Low frequency cut-off associated with a horn is extended by configuring the radiator drive impedance to approach a short circuit at low frequencies. A tapered feed plate connects at one end to a feedline, and at the other end to a launcher plate which is mounted to an inside wall of the horn. The launcher plate and feed plate join at an abrupt edge which forms the single launch point of the antenna.

  9. Ultra-wideband horn antenna with abrupt radiator

    DOE Patents [OSTI]

    McEwan, T.E.

    1998-05-19

    An ultra-wideband horn antenna transmits and receives impulse waveforms for short-range radars and impulse time-of flight systems. The antenna reduces or eliminates various sources of close-in radar clutter, including pulse dispersion and ringing, sidelobe clutter, and feedline coupling into the antenna. Dispersion is minimized with an abrupt launch point radiator element; sidelobe and feedline coupling are minimized by recessing the radiator into a metallic horn. Low frequency cut-off associated with a horn is extended by configuring the radiator drive impedance to approach a short circuit at low frequencies. A tapered feed plate connects at one end to a feedline, and at the other end to a launcher plate which is mounted to an inside wall of the horn. The launcher plate and feed plate join at an abrupt edge which forms the single launch point of the antenna. 8 figs.

  10. Assessment of a field-aligned ICRF antenna

    E-Print Network [OSTI]

    Wukitch, Stephen James

    2014-01-01

    Impurity contamination and localized heat loads associated with ion cyclotron range of frequency (ICRF) antenna operation are among the most challenging issues for ICRF utilization.. Another challenge is maintaining maximum ...

  11. Analysis and Design of a Multifunctional Spiral Antenna 

    E-Print Network [OSTI]

    Chen, Teng-Kai

    2012-10-19

    for the characteristics of spiral antenna has remained somewhat elusive. This has been studied qualitatively and evaluated using numerical and experimental techniques with some success, but many of these methods are not convenient in the design process since they do...

  12. Towards Tag Antenna Based Sensing - An RFID Displacement Sensor

    E-Print Network [OSTI]

    Sarma, Sanjay Emani

    The following topics are dealt with: tag circuits; measurement method; simulation method; health care; protocol; sensors; open source RFID software; privacy; security; reader design; antenna; propagation; near-field ...

  13. Compact antenna arrays with wide bandwidth and low sidelobe levels

    DOE Patents [OSTI]

    Strassner, II, Bernd H.

    2014-09-09

    Highly efficient, low cost, easily manufactured SAR antenna arrays with lightweight low profiles, large instantaneous bandwidths and low SLL are disclosed. The array topology provides all necessary circuitry within the available antenna aperture space and between the layers of material that comprise the aperture. Bandwidths of 15.2 GHz to 18.2 GHz, with 30 dB SLLs azimuthally and elevationally, and radiation efficiencies above 40% may be achieved. Operation over much larger bandwidths is possible as well.

  14. Characterization of local heat fluxes around ICRF antennas on JET

    SciTech Connect (OSTI)

    Campergue, A.-L.; Jacquet, P.; Monakhov, I.; Arnoux, G.; Brix, M.; Sirinelli, A.; Milanesio, D.; Colas, L.; Collaboration: JET-EFDA Contributors

    2014-02-12

    When using Ion Cyclotron Range of Frequency (ICRF) heating, enhanced power deposition on Plasma-Facing Components (PFCs) close to the antennas can occur. Experiments have recently been carried out on JET with the new ITER-Like-Wall (ILW) to characterize the heat fluxes on the protection of the JET ICRF antennas, using Infra-Red (IR) thermography measurement. The measured heat flux patterns along the poloidal limiters surrounding powered antennas were compared to predictions from a simple RF sheath rectification model. The RF electric field, parallel to the static magnetic field in front of the antenna, was evaluated using the TOPICA code, integrating a 3D flattened model of the JET A2 antennas. The poloidal density variation in front of the limiters was obtained from the mapping of the Li-beam or edge reflectometry measurements using the flux surface geometry provided by EFIT equilibrium reconstruction. In many cases, this simple model can well explain the position of the maximum heat flux on the different protection limiters and the heat-flux magnitude, confirming that the parallel RF electric field and the electron plasma density in front of the antenna are the main driving parameters for ICRF-induced local heat fluxes.

  15. Geology of the Florida Canyon gold deposit, Pershing County,...

    Open Energy Info (EERE)

    Geology of the Florida Canyon gold deposit, Pershing County, Nevada, in: Gold and Silver Deposits of Western Nevada Jump to: navigation, search OpenEI Reference LibraryAdd to...

  16. Electronic interactions between gold films and mn12-acetate 

    E-Print Network [OSTI]

    Means, Joel Lewis

    2009-05-15

    Interactions between Mn12–acetate molecular magnets and thin gold films have been explored in light of the theory of weak localization. Low-temperature measurements of the magnetoresistance of gold films of varying thicknesses, with and without...

  17. Analysis, Design, and Operation of a Spherical Inverted-F Antenna 

    E-Print Network [OSTI]

    McDonald, Jacob J.

    2010-07-14

    This thesis presents the analysis, design, and fabrication of a spherical inverted-F antenna (SIFA). The SIFA consists of a spherically conformal rectangular patch antenna recessed into a quarter section of a metallic ...

  18. Ferromagnetic Antenna and its Application to Generation and Detection of Gravitational Radiation

    E-Print Network [OSTI]

    Fran De Aquino

    2002-10-30

    A new type of antenna, which we have called Ferromagnetic Antenna, has been considered for Generation and Detection of Gravitational Radiation. A simple experiment, in which gravitational radiation at 10 GHz can be emitted and received in laboratory, is presented.

  19. JOHN L. VOLAKIS, Chope Chair Professor 2004 President, IEEE Antennas and Propagation Society

    E-Print Network [OSTI]

    Volakis, John L.

    , novel materials, terahertz devices and applications, multi-physics engineering, computational methods & Claypool, 2007), Antenna Engineering Handbook, ed. (McGraw-Hill, 2007), Computational Methods for High delivered short courses for numerous organizations on numerical methods, antennas, and frequency selective

  20. Multi-dimensional ultra-high frequency passive radio frequency identification tag antenna designs

    E-Print Network [OSTI]

    Delichatsios, Stefanie Alkistis

    2006-01-01

    In this thesis, we present the design, simulation, and empirical evaluation of two novel multi-dimensional ultra-high frequency (UHF) passive radio frequency identification (RFID) tag antennas, the Albano-Dipole antenna ...

  1. 1 | P a g e Boiler Gold Rush

    E-Print Network [OSTI]

    Ginzel, Matthew

    1 | P a g e Boiler Gold Rush VISION STATEMENT The vision of BGR is twofold: first, help all new by participating in the premiere orientation program in the nation, Boiler Gold Rush. Second, enhance upper leaders for the betterment of the university. PROGRAM GOALS Boiler Gold Rush will provide the following

  2. Gold-coated nanoparticles for use in biotechnology applications

    DOE Patents [OSTI]

    Berning, Douglas E. (Los Alamos, NM); Kraus, Jr., Robert H. (Los Alamos, NM); Atcher, Robert W. (Los Alamos, NM); Schmidt, Jurgen G. (Los Alamos, NM)

    2009-07-07

    A process of preparing gold-coated magnetic nanoparticles is disclosed and includes forming a suspension of magnetic nanoparticles within a suitable liquid, adding an amount of a reducible gold compound and a reducing agent to the suspension, and, maintaining the suspension for time sufficient to form gold-coated magnetic nanoparticles.

  3. Novel antenna coupled 2D plasmonic terahertz detection.

    SciTech Connect (OSTI)

    Allen, Jim (UC Santa Barbara); Dyer, Greg (UC Santa Barbara); Reno, John Louis; Shaner, Eric Arthur

    2010-03-01

    Resonant plasmonic detectors are potentially important for terahertz (THz) spectroscopic imaging. We have fabricated and characterized antenna coupled detectors that integrate a broad-band antenna, which improves coupling of THz radiation. The vertex of the antenna contains the tuning gates and the bolometric barrier gate. Incident THz radiation may excite 2D plasmons with wave-vectors defined by either a periodic grating gate or a plasmonic cavity determined by ohmic contacts and gate terminals. The latter approach of exciting plasmons in a cavity defined by a short micron-scale channel appears most promising. With this short-channel geometry, we have observed multiple harmonics of THz plasmons. At 20 K with detector bias optimized we report responsivity on resonance of 2.5 kV/W and an NEP of 5 x 10{sup -10} W/Hz{sup 1/2}.

  4. Time-delayed directional beam phased array antenna

    DOE Patents [OSTI]

    Fund, Douglas Eugene; Cable, John William; Cecil, Tony Myron

    2004-10-19

    An antenna comprising a phased array of quadrifilar helix or other multifilar antenna elements and a time-delaying feed network adapted to feed the elements. The feed network can employ a plurality of coaxial cables that physically bridge a microstrip feed circuitry to feed power signals to the elements. The cables provide an incremental time delay which is related to their physical lengths, such that replacing cables having a first set of lengths with cables having a second set of lengths functions to change the time delay and shift or steer the antenna's main beam. Alternatively, the coaxial cables may be replaced with a programmable signal processor unit adapted to introduce the time delay using signal processing techniques applied to the power signals.

  5. The Study and Implementation of Electrically Small Printed Antennas for an Integrated Transceiver Design

    E-Print Network [OSTI]

    Speer, Peter Clark

    2009-01-01

    -monopole antenna, (c) Short meandering-monopole antenna, (d) Compact meandering-monopole antenna, and (e) Loop antenna. .................................. 52 Figure 4.1.2: LPKF Minicontac-RS through-hole electroplating bath... circuitry must have the ability to accommodate additional detuning caused by the packaging process. An evenly coated 0.200" epoxy layer will eventually be used to ruggedize the design. To be useful in future designs and to maintain compatibility...

  6. Fluidic, Solid-State, and Hybrid Reconfiguration Techniques in a Frequency and Polarization Reconfigurable Antenna 

    E-Print Network [OSTI]

    Barrera, Joel Daniel

    2014-12-16

    Reconfigurable Antenna ISM Industrial, scientific, and medical I-V Current and voltage MEMS Microelectromechanical systems MS Microstrip PDMS Polydimethylsiloxane PIN P-type, intrinsic, N-type PN P-type and N-type PRA Polarization Reconfigurable Antenna...-8], and RF-MEMS [9-11] on or near the antenna surface. In [1], the authors achieve a widely frequency agile microstrip patch antenna by integrating three pairs of varactor diodes along with a broadband differential feeding scheme. Furthermore, the authors...

  7. A classification of multiple antenna channels Joseph J. Boutros, Fatma KharratKammoun, and Hugues Randriambololona

    E-Print Network [OSTI]

    Randriam, Hugues

    antenna digital transmissions [1] made us focus the application of our Hermitian forms classificationA classification of multiple antenna channels Joseph J. Boutros, Fatma Kharrat­Kammoun, and Hugues,fkharrat,randriam}@enst.fr Abstract--- We propose a new classification of multiple antenna channels. The classification is performed

  8. A classification of multiple antenna channels Joseph J. Boutros, Fatma Kharrat-Kammoun, and Hugues Randriambololona

    E-Print Network [OSTI]

    Randriam, Hugues

    antenna digital transmissions [1] made us focus the application of our Hermitian forms classificationA classification of multiple antenna channels Joseph J. Boutros, Fatma Kharrat-Kammoun, and Hugues,fkharrat,randriam}@enst.fr Abstract-- We propose a new classification of multiple antenna channels. The classification is performed

  9. Construction of a polarization sensitive planar antenna for microwaves in the centimeter range

    E-Print Network [OSTI]

    Construction of a polarization sensitive planar antenna for microwaves in the centimeter range the construction of the actual antenna circuit took place, a number of tests were performed to develop of various techniques. Following these tests, a prototype antenna circuit was constructed and measurements

  10. Delivering both sum and difference beam distributions to a planar monopulse antenna array

    DOE Patents [OSTI]

    Strassner II, Bernd H.

    2015-12-22

    A planar monopulse radar apparatus includes a planar distribution matrix coupled to a planar antenna array having a linear configuration of antenna elements. The planar distribution matrix is responsive to first and second pluralities of weights applied thereto for providing both sum and difference beam distributions across the antenna array.

  11. Optimized dipole antennas on photonic band gap crystals S. D. Chenga)

    E-Print Network [OSTI]

    Ozbay, Ekmel

    efficiencies larger than antennas on other conventional dielectric substrates. © 1995 American Institute . A three-cylinder structure with diamond symmetry fabricated by drilling techniques first demonstrated3; an efficient directional antenna. Conventional integrated circuit antennas on a semi-infinite semiconductor

  12. Graphene-based nano-patch antenna for terahertz radiation Ignacio Llatser

    E-Print Network [OSTI]

    Politècnica de Catalunya, Universitat

    Graphene-based nano-patch antenna for terahertz radiation Ignacio Llatser Nanonetworking Center The scattering of terahertz radiation on a graphene-based nano-patch antenna is numerically analyzed of surface plasmon polaritons supported by the graphene lm. A strong tunability of the antenna resonances via

  13. Superconducting cavity transducer for resonant gravitational radiation antennas

    E-Print Network [OSTI]

    R. Ballantini; M. Bassan; A. Chincarini; G. Gemme; R. Parodi; R. Vaccarone

    2006-02-15

    Parametric transducers, such as superconducting rf cavities, can boost the bandwidth and sensitivity of the next generation resonant antennas, thanks to a readily available technology. We have developed a fully coupled dynamic model of the system "antenna--transducer" and worked out some estimates of signal--to--noise ratio and the stability conditions in various experimental configurations. We also show the design and the prototype of a rf cavity which, together with a suitable read--out electronic, will be used as a test bench for the parametric transducer.

  14. Shape separation of gold nanorods using centrifugation

    E-Print Network [OSTI]

    Sharma, Vivek

    Shape separation of gold nanorods using centrifugation Vivek Sharmaa,1 , Kyoungweon Parka,2 , and Mohan Srinivasaraoa,b,c,3 aSchool of Polymer Textile and Fiber Engineering, bCenter for Advanced, and approved January 23, 2009 (received for review January 29, 2008) We demonstrate the use of centrifugation

  15. X-ray laser driven gold targets

    SciTech Connect (OSTI)

    Petrova, Tz. B., E-mail: lina.petrova@nrl.navy.mil; Whitney, K. G.; Davis, J. [Plasma Physics Division, Naval Research Laboratory, 4555 Overlook Ave. SW, Washington, DC 20375 (United States)] [Plasma Physics Division, Naval Research Laboratory, 4555 Overlook Ave. SW, Washington, DC 20375 (United States)

    2014-03-15

    The femtosecond population dynamics of gold irradiated by a coherent high-intensity (>10{sup 17}?W/cm{sup 2}) x-ray laser pulse is investigated theoretically. There are two aspects to the assembled model. One is the construction of a detailed model of platinum-like gold inclusive of all inner-shell states that are created by photoionization of atomic gold and decay either by radiative or Auger processes. Second is the computation of the population dynamics that ensues when an x-ray pulse is absorbed in gold. The hole state generation depends on the intensity and wavelength of the driving x-ray pulse. The excited state populations reached during a few femtosecond timescales are high enough to generate population inversions, whose gain coefficients are calculated. These amplified lines in the emitted x-ray spectrum provide important diagnostics of the radiation dynamics and also suggest a nonlinear way to increase the frequency of the coherent output x-ray pulses relative to the frequency of the driver input x-ray pulse.

  16. Mining Gold from your Cooling Water System 

    E-Print Network [OSTI]

    Mendez, T.

    2007-01-01

    stream_source_info ESL-IE-07-05-25.pdf.txt stream_content_type text/plain stream_size 6756 Content-Encoding ISO-8859-1 stream_name ESL-IE-07-05-25.pdf.txt Content-Type text/plain; charset=ISO-8859-1 Mining Gold from your...

  17. Development of horn antenna mixer array with internal local oscillator module for microwave imaging diagnostics

    SciTech Connect (OSTI)

    Kuwahara, D., E-mail: dkuwahar@cc.tuat.ac.jp [Department of Mechanical Systems Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588 (Japan); Ito, N. [Department of Intelligent System Engineering, Ube National College of Technology, Ube, Yamaguchi 755-8555 (Japan); Nagayama, Y. [Department of Helical Plasma Research, National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan); Yoshinaga, T. [Department of Applied Physics, National Defense Academy, Yokosuka, Kanagawa 239-0811 (Japan); Yamaguchi, S. [Department of Pure and Applied Physics, Kansai University, Suita, Osaka 564-8680 (Japan); Yoshikawa, M.; Kohagura, J. [Graduate School of Pure and Applied Science, University of Tsukuba, Tsukuba, Ibaraki 305-8577 (Japan); Sugito, S. [Equipment Development Center, Institute for Molecular Science, Okazaki, Aichi 444-8585 (Japan); Kogi, Y. [Department of Information Electronics, Fukuoka Institute of Technology, Fukuoka, Fukuoka 811-0295 (Japan); Mase, A. [Art, Science and Technology Center for Cooperative Research, Kyusyu University, Kasuga, Fukuoka 816-8580 (Japan)

    2014-11-15

    A new antenna array is proposed in order to improve the sensitivity and complexity of microwave imaging diagnostics systems such as a microwave imaging reflectometry, a microwave imaging interferometer, and an electron cyclotron emission imaging. The antenna array consists of five elements: a horn antenna, a waveguide-to-microstrip line transition, a mixer, a local oscillation (LO) module, and an intermediate frequency amplifier. By using an LO module, the LO optics can be removed, and the supplied LO power to each element can be equalized. We report details of the antenna array and characteristics of a prototype antenna array.

  18. MINIATURIZED BROADBAND ANTENNA DESIGN VIA SIMP G. Kiziltasa

    E-Print Network [OSTI]

    Sendur, Gullu Kiziltas

    final design using Thermoplastic Green Machining demonstrates the ability to design and manufactureMINIATURIZED BROADBAND ANTENNA DESIGN VIA SIMP G. Kiziltasa , N. Kikuchia , J. Volakisb-1191 volakis.1@osu.edu Design optimization for electromagnetic applications has traditionally been a process

  19. FAILURE BEHAVIOR IDENTIFICATION FOR A SPACE ANTENNA VIA NEURAL NETWORKS

    E-Print Network [OSTI]

    Antsaklis, Panos

    FAILURE BEHAVIOR IDENTIFICATION FOR A SPACE ANTENNA VIA NEURAL NETWORKS Michcl A. Sartoi David Taylo Research Center Code 1941 BeteA Mayln 200845000 ABSTRACT Using neural networks, a method-layer perceptron, the second uses a multi-layer perceptron and neural networks trained with the quadratic

  20. A Simple Measurement Technique for Characterizing Active Antennas

    E-Print Network [OSTI]

    York, Robert A.

    at the receiver from the AUT. Here we assume that there is no transmission through the ampli- fier with DC bias has recently been described which is suit- able for transmission amplifiers [1]-[3].This technique uses two standard waveguide horn antennas to measure the power transmission through the amplifier cell

  1. Tone based MAC protocol for use with Adaptive Array Antennas

    E-Print Network [OSTI]

    Singh, Suresh

    Abstract--This paper presents a novel Tone-based 802.11b protocol for use in wireless networks where nodes understand the networking issues in WLAN. The predominant model used in most of this work has assumed omni-directional antennas in which the transmission energy is spread out in all the directions from the sender. In this work

  2. Rate Adaptation in MIMO Antenna Selection System with Imperfect CSIT

    E-Print Network [OSTI]

    Bhashyam, Srikrishna

    constant power and rate will lead to block errors during the poor channel conditions or under utilization that encompasses feedback delay, estimation errors and prediction. However, rate adaptation has not been consideredRate Adaptation in MIMO Antenna Selection System with Imperfect CSIT T. R. Ramya and Srikrishna

  3. Antenna Array Mutual Coupling Effects on Cellular CDMA Communication Systems

    E-Print Network [OSTI]

    Blostein, Steven D.

    & Steven D. Blostein Department of Electrical & Computer Engineering, Queen's University Kingston, Ontario market, new techniques must be devel­ opped which can further increase cell capacity to meet fu­ ture and/or receiving, some of the energy that is primarily intended for one antenna ends up at the other

  4. 1 Antenna Beamforming and Power Control for Ad Hoc Networks

    E-Print Network [OSTI]

    Ramanathan, Ram

    parameters ­ transmit power, and antenna beam direction ­ and present state-of-the-art methods control includes reduced interference and lower energy consumption. Beamforming and lower powers are also and power control appears to have potential, a number of questions need to be answered: What techniques

  5. GNSS Multipath Mitigation using High-Frequency Antenna Motion

    E-Print Network [OSTI]

    Psiaki, Mark L.

    GNSS Multipath Mitigation using High- Frequency Antenna Motion Tunc Ertan, Mark L. Psiaki, Brady W. O'Hanlon, Richard A. Merluzzi and Steven P. Powell, Cornell University, Ithaca, NY BIOGRAPHIES Tunc interests are in the areas of GNSS technologies, and nonlinear estimation and filtering. Mark L. Psiaki

  6. GNSS Spoofing Detection using Two-Antenna Differential Carrier Phase

    E-Print Network [OSTI]

    Psiaki, Mark L.

    GNSS Spoofing Detection using Two-Antenna Differential Carrier Phase Mark L. Psiaki, Brady W. O'Hanlon, Sea ID, 06320, Cap d'Ail, France BIOGRAPHIES Mark L. Psiaki is a Professor of Mechanical and Aerospace, spacecraft attitude and orbit determination, and general estimation, filtering, and detection. Brady W. O'Hanlon

  7. Correlated Interference Analysis in CDMA MultiAntenna Systems \\Lambda

    E-Print Network [OSTI]

    Yanikomeroglu, Halim

    ­mail: halim@sce.carleton.ca 2 Dept. of Electrical and Computer Engineering -- University of Toronto, Canada E antenna elements (AE's) are connected to a central station (CS) with separate feeders. All of the intelligence is centralized at the CS; thus, there is no signal­specific processing at the AE's. In the reverse

  8. Antenna Systems Over-The-Air characterization of

    E-Print Network [OSTI]

    Ahrendt, Wolfgang

    Antenna-Based Signal Processing Wideband MIMO radar: tx/rx filter and waveform design Compressed Sensing and sparsity-based estimation Numerical modeling Model-based evaluation and design using computational EM, Tomas McKelvey, Mats Viberg #12;Microwave Technologies MMIC design Multifunctional THz > 300 GHz

  9. Electro-optically responsive composites of gold nanospheres in 5CB liquid crystal under direct current and alternating current joint action

    SciTech Connect (OSTI)

    Hadjichristov, Georgi B.; Marinov, Yordan G.; Petrov, Alexander G.; Bruno, Emanuela; Marino, Lucia; Scaramuzza, Nicola

    2014-02-28

    Direct current (DC) electro-optical (EO) control of transmitted laser beam intensity based on EO controlled coherent light scattering and diffraction by stationary longitudinal texture pattern (LTP) is achieved in planar-oriented cells with a composite mixture of polymer-coated gold spherical nanoparticles (Au-NPs) with a mean diameter of about 12?nm and the room-temperature nematic pentylcyanobiphenyl (5CB). At relatively low DC voltage of about 5 V, the effective scattering/diffraction by Au-NPs/5CB composites leads to a spatial spreading of transmitted coherent light from a low-power continuous wave laser beam, resulting in a drastic reduction of its local intensity. The effect is polarization dependent and is strongest when the polarization of the input laser beam is along the LTP. The EO response of Au-NPs/5CB mixtures is studied under DC and alternating current (AC) joint action with the aim of the potential use of these composite materials as EO controlled diffusers. The specific V-shaped sharp dip in the DC voltage-dependent coherent light transmittance of Au-NPs/5CB planar films, as well as the possibility for erasing the scattering/diffractive LTP in the films by joint low AC voltage, can be useful for EO applications in the field of process control and for detection of weak dynamic electric fields.

  10. Electrochemistry on Alternate Structures of Gold Nanoparticles Bull. Korean Chem. Soc. 2004, Vol. 25, No. 11 1681 Electrochemistry on Alternate Structures of Gold Nanoparticles

    E-Print Network [OSTI]

    Kwak, Juhyoun

    Electrochemistry on Alternate Structures of Gold Nanoparticles Bull. Korean Chem. Soc. 2004, Vol. 25, No. 11 1681 Electrochemistry on Alternate Structures of Gold Nanoparticles and Ferrocene

  11. IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS, VOL. 11, 2012 663 Monopole Antenna With Inkjet-Printed EBG Array

    E-Print Network [OSTI]

    Tentzeris, Manos

    . The printed EBG array is placed above a copper sheet, forming an artificial magnetic conductor (AMC) reflector and more important because of the constantly increasing demand for tracking, navigation, mobile computing. In this letter, a microstrip monopole antenna, backed with an inkjet-printed EBG array and a metallic copper

  12. IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, VOL. 59, NO. 11, NOVEMBER 2011 4209 A Novel Multiband Planar Antenna for

    E-Print Network [OSTI]

    Tentzeris, Manos

    Multiband Planar Antenna for GSM/UMTS/LTE/Zigbee/RFID Mobile Devices Ting Zhang, RongLin Li, Senior Member of global-operability RFID readers and RFID-enabled wireless sensors Zigbee-based controllers in state operating bands that effectively cover the GSM/UMTS/LTE/Zigbee/RFID oper- ations in mobile de

  13. 469IEEE TRANSACTIONSON ANTENNAS AND PROPAGATION, VOL. AP-30, NO. 3, MAY 1982 Signal Cancellation Phenomena in Adaptive Antennas

    E-Print Network [OSTI]

    Widrow, Bernard

    Phenomena in Adaptive Antennas: Causes and Cures BERNARD WIDROW, FELLOW, IEEE, KENNETH M. DUVALL, MEMBER beamformers, Manuscript received lanuary 6 , 1981; revised August 10, 1981. This work was supported in.part by the Naval Air Systems Command under Contract N00019-79C-0331 and by ONR under Contract N00014-76- B. Widrow

  14. The impact of reduced conductivity on the performance of wire antennas

    E-Print Network [OSTI]

    Morteza Shahpari; David V. Thiel

    2015-09-17

    Low cost methods of antenna production primarily aim to reduce the cost of metalization. This might lead to a reduction in conductivity. A systematic study on the impact of conductivity is presented. The efficiency, gain and bandwidth of cylindrical wire meander line, dipole, and Yagi-Uda antennas were compared for materials with conductivities in the range $\\mathrm{10^3}$ to $\\mathrm{10^9}$ S/m. In this range, the absorption efficiency of both the dipole and meander line changed little, however the conductivity significantly impacts on radiation efficiency and the absorption cross section of the antennas. The extinction cross section of the dipole and meander line antennas (antennas that Thevenin equivalent circuit is applicable) also vary with radiation efficiency. From the point of radiation efficiency, the dipole antenna performance is most robust under decreasing conductivity. The power to volume ratio reveals that the meander line antenna is more economical than dipole and Yagi antennas in terms of cost of metalization when $\\sigma > 2 \\times 10^5 S/m$. Antennas studied in this study were fabricated with brass and graphite. Radiation efficiency of the antennas were measured by improved Wheeler cap (IWC) method. Measurement results showed a reasonable agreement with simulations. We also measured the extinction cross section of the six fabricated prototypes.

  15. Federal Electronics Challenge Gold Award | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    DOE Headquarters was presented the Federal Electronics Challenge Gold Award for exemplary performance in Green Computing, including green procurement, energy efficient operations...

  16. Sponsored by Nanotechnology Seminar Program Surface Chemistry of Gold

    E-Print Network [OSTI]

    Fisher, Frank

    Sponsored by Nanotechnology Seminar Program Surface Chemistry of Gold Nanorods: Wrapping chemistry, biophysical chemistry and nanotechnology, with a primary goal to develop inorganic nanomaterials

  17. Effect of Gold Nanorod Surface Chemistry on Cellular Response

    E-Print Network [OSTI]

    Grabinski, Christin

    Gold nanorods (GNRs) stabilized with cetyltrimethylammonium bromide (CTAB) and GNR functionalized via a ligand exchange method with either thiolated polyethylene glycol (PEG5000) or mercaptohexadecanoic acid (MHDA) were ...

  18. Argonne APCF achieves LEED Gold rating | Argonne National Laboratory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Laboratory's Advanced Protein Characterization Facility (APCF) has received the U.S. Green Building Council's Leadership in Energy and Environmental Design (LEED) Gold...

  19. Epithermal Gold Mineralization and a Geothermal Resource at Blue...

    Open Energy Info (EERE)

    Epithermal Gold Mineralization and a Geothermal Resource at Blue Mountain, Humboldt County, Nevada Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal...

  20. Los Alamos explores hybrid ultrasmall gold nanocluster for enzymatic...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Alamos explores hybrid ultrasmall gold nanocluster for enzymatic fuel cells With fossil-fuel sources dwindling, better biofuel cell design is a strong candidate in the energy...

  1. The Study and Implementation of Electrically Small Printed Antennas for an Integrated Transceiver Design

    SciTech Connect (OSTI)

    Speer, Pete

    2009-04-15

    This work focuses on the design and evaluation of the inverted-F, meandering-monopole, and loop antenna geometries. These printed antennas are studied with the goal of identifying which is suitable for use in a miniaturized transceiver design and which has the ability to provide superior performance using minimal Printed Circuit Board (PCB) space. As a result, the main objective is to characterize tradeoffs and identify which antenna provides the best compromise among volume, bandwidth and efficiency. For experimentation purposes, three types of meandering-monopole antenna are examined resulting in five total antennas for the study. The performance of each antenna under study is evaluated based upon return loss, operational bandwidth, and radiation pattern characteristics. For our purposes, return loss is measured using the S11-port reflection coefficient which helps to characterize how well the small antenna is able to be efficiently fed. Operational bandwidth is measured as the frequency range over which the antenna maintains 2:1 Voltage Standing Wave Ratio (VSWR) or equivalently has 10-dB return loss. Ansoft High Frequency Structure Simulator (HFSS) is used to simulate expected resonant frequency, bandwidth, VSWR, and radiation pattern characteristics. Ansoft HFSS simulation is used to provide a good starting point for antenna design before actual prototype are built using an LPKF automated router. Simulated results are compared with actual measurements to highlight any differences and help demonstrate the effects of antenna miniaturization. Radiation characteristics are measured illustrating how each antenna is affected by the influence of a non-ideal ground plane. The antenna with outstanding performance is further evaluated to determine its maximum range of communication. Each designs range performance is evaluated using a pair of transceivers to demonstrate round-trip communication. This research is intended to provide a knowledge base which will help decrease the number of design iterations needed for future implementation of products requiring integration of small printed antennas. In the past, several design iterations have been needed to fine tune antenna dimensions and achieve acceptable levels of performance. This process consumes a large amount of time and material resources leading to costly development of transceiver designs. Typically, this occurs because matching components and antenna geometries are almost never correct on the first design. This work hopes to determine the limitations associated with antenna miniaturization and provide well known antenna examples that can be easily used in future work.

  2. Overview of Sandia National Laboratories and Antenna Development Department

    SciTech Connect (OSTI)

    Brock, B.C.

    1994-04-01

    Sandia is a multiprogram R & D laboratory. It has responsibilities in the following areas: (1) defense programs; (2) energy and environment; and (3) work for others (DOD, NSA, etc.). In 1989, the National Competitiveness Technology Transfer Act added another responsibility -- contributions to industrial competitiveness. Sandia has two major laboratory locations, New Mexico and California, and two flight testing locations, Tonopah Test Range, Nevada and Kauai Test Facility, Hawaii. The last part of this talk was dedicated to antenna research at Sandia.

  3. Radiofrequency plasma antenna generated by femtosecond laser filaments in air

    SciTech Connect (OSTI)

    Brelet, Y.; Houard, A.; Point, G.; Prade, B.; Carbonnel, J.; Andre, Y.-B.; Mysyrowicz, A. [Laboratoire d'Optique Appliquee, ENSTA ParisTech, Ecole Polytechnique, CNRS, 91761 Palaiseau (France); Arantchouk, L. [Laboratoire de Physique des Plasmas, Ecole Polytechnique, CNRS, Palaiseau (France); Pellet, M. [Etat-major de la Marine Nationale, Paris (France)

    2012-12-24

    We demonstrate tunable radiofrequency emission from a meter-long linear plasma column produced in air at atmospheric pressure. A short-lived plasma column is initially produced by femtosecond filamentation and subsequently converted into a long-lived discharge column by application of an external high voltage field. Radiofrequency excitation is fed to the plasma by induction and detected remotely as electromagnetic radiation by a classical antenna.

  4. Antenna-coupled high T[sub c] superconducting microbolometer

    DOE Patents [OSTI]

    Hu, Q.

    1992-12-15

    A device is provided for measuring radiant energy, the device comprising a substrate; a bolometer formed from a high T[sub c] superconducting material disposed on the substrate in an area that is about 1[times]5 [mu]m[sup 2] and about 0.02 [mu]m in depth; and a planar antenna disposed on the substrate and coupled to receive radiation and to impart the received radiation to the bolometer. 5 figs.

  5. Measuring Helical FCG Voltage with an Electric Field Antenna

    SciTech Connect (OSTI)

    White, A D; Anderson, R A; Javedani, J B; Reisman, D B; Goerz, D A; Ferriera, A J; Speer, R D

    2011-08-01

    A method of measuring the voltage produced by a helical explosive flux compression generator using a remote electric field antenna is described in detail. The diagnostic has been successfully implemented on several experiments. Measured data from the diagnostic compare favorably with voltages predicted using the code CAGEN, validating our predictive modeling tools. The measured data is important to understanding generator performance, and is measured with a low-risk, minimally intrusive approach.

  6. Searching for WISPy cold dark matter with a dish antenna

    SciTech Connect (OSTI)

    Horns, Dieter; Jaeckel, Joerg; Lindner, Axel; Ringwald, Andreas; Lobanov, Andrei; Redondo, Javier E-mail: jjaeckel@thphys.uni-heidelberg.de E-mail: alobanov@mpifr-bonn.mpg.de E-mail: andreas.ringwald@desy.de

    2013-04-01

    The cold dark matter of the Universe may be comprised of very light and very weakly interacting particles, so-called WISPs. Two prominent examples are hidden photons and axion-like particles. In this note we propose a new technique to sensitively search for this type of dark matter with dish antennas. The technique is broadband and allows to explore a whole range of masses in a single measurement.

  7. Air Shower Measurements with the LOPES Radio Antenna Array

    E-Print Network [OSTI]

    A. Haungs; for the LOPES collaboration

    2008-11-12

    LOPES is set up at the location of the KASCADE-Grande extensive air shower experiment in Karlsruhe, Germany and aims to measure and investigate radio pulses from Extensive Air Showers. Since radio waves suffer very little attenuation, radio measurements allow the detection of very distant or highly inclined showers. These waves can be recorded day and night, and provide a bolometric measure of the leptonic shower component. LOPES is designed as a digital radio interferometer using high bandwidths and fast data processing and profits from the reconstructed air shower observables of KASCADE-Grande. The LOPES antennas are absolutely amplitude calibrated allowing to reconstruct the electric field strength which can be compared with predictions from detailed Monte Carlo simulations. We report about the analysis of correlations present in the radio signals measured by the LOPES 30 antenna array. Additionally, LOPES operates antennas of a different type (LOPES-STAR) which are optimized for an application at the Pierre Auger Observatory. Status, recent results of the data analysis and further perspectives of LOPES and the possible large scale application of this new detection technique are discussed.

  8. Method of making radio frequency ion source antenna

    DOE Patents [OSTI]

    Ehlers, Kenneth W. (Alamo, CA); Leung, Ka-Ngo (Hercules, CA)

    1988-01-01

    In the method, the radio frequency (RF) antenna is made by providing a clean coil made of copper tubing or other metal conductor, which is coated with a tacky organic binder, and then with a powdered glass frit, as by sprinkling the frit uniformly over the binder. The coil is then heated internally in an inert gas atmosphere, preferably by passing an electrical heating current along the coil. Initially, the coil is internally heated to about 200.degree. C. to boil off the water from the binder, and then to about 750.degree. C.-850.degree. C. to melt the glass frit, while also burning off the organic binder. The melted frit forms a molten glass coating on the metal coil, which is then cooled to solidify the glass, so that the metal coil is covered with a thin continuous homogeneous impervious glass coating of substantially uniform thickness. The glass coating affords complete electrical insulation and complete dielectric protection for the metal coil of the RF antenna, to withstand voltage breakdown and to prevent sputtering, while also doubling the plasma generating efficiency of the RF antenna, when energized with RF power in the vacuum chamber of an ion source for a particle accelerator or the like. The glass frit preferably contains apprxoimately 45% lead oxide.

  9. Gold nanoparticle formation in diamond-like carbon using two different methods: Gold ion implantation and co-deposition of gold and carbon

    SciTech Connect (OSTI)

    Salvadori, M. C.; Teixeira, F. S.; Araujo, W. W. R.; Sgubin, L. G.; Cattani, M.; Spirin, R. E.; Brown, I. G.

    2012-10-01

    We describe work in which gold nanoparticles were formed in diamond-like carbon (DLC), thereby generating a Au-DLC nanocomposite. A high-quality, hydrogen-free DLC thin film was formed by filtered vacuum arc plasma deposition, into which gold nanoparticles were introduced using two different methods. The first method was gold ion implantation into the DLC film at a number of decreasing ion energies, distributing the gold over a controllable depth range within the DLC. The second method was co-deposition of gold and carbon, using two separate vacuum arc plasma guns with suitably interleaved repetitive pulsing. Transmission electron microscope images show that the size of the gold nanoparticles obtained by ion implantation is 3-5 nm. For the Au-DLC composite obtained by co-deposition, there were two different nanoparticle sizes, most about 2 nm with some 6-7 nm. Raman spectroscopy indicates that the implanted sample contains a smaller fraction of sp{sup 3} bonding for the DLC, demonstrating that some sp{sup 3} bonds are destroyed by the gold implantation.

  10. Method for aqueous gold thiosulfate extraction using copper-cyanide pretreated carbon adsorption

    DOE Patents [OSTI]

    Young, Courtney; Melashvili, Mariam; Gow, Nicholas V

    2013-08-06

    A gold thiosulfate leaching process uses carbon to remove gold from the leach liquor. The activated carbon is pretreated with copper cyanide. A copper (on the carbon) to gold (in solution) ratio of at least 1.5 optimizes gold recovery from solution. To recover the gold from the carbon, conventional elution technology works but is dependent on the copper to gold ratio on the carbon.

  11. Miniaturized Multi-Band Antenna Design via Element Collocation and Inductive Feed Loading

    SciTech Connect (OSTI)

    Martin, R. P.

    2012-09-12

    In a FY09 SDRD project, four separate antennas were designed to receive signals of interest covering a broad range of frequencies. While the elements exceeded specifications, the array footprint is substantial. Research performed by the CU Microwave Active Antenna Group in collaboration with RSL, showed promise in realizing a reduced structure. This work will expand upon this previous research. This project will result in a prototype quad-band antenna.

  12. BlackGold Biofuels | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX ECoop IncIowaWisconsin:Pontiac Biomass Facility JumpII Jump to:BitworksFarmBlackGold

  13. Solving the Unsovlable: The Nanostructure of Gold at 1.1 Å Resolution

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    foundation for modern-day chemistry. Today, iridescent gold particles are used in biosensors, drug delivery, and many other applications, but for all gold's uses, the structure...

  14. Investigation of fluorine-doped tin oxide based optically transparent E-shaped patch antenna for terahertz communications

    SciTech Connect (OSTI)

    Anand, S., E-mail: anand.s.krishna@gmail.com, E-mail: darak.mayur@gmail.com, E-mail: srk@nitt.edu; Darak, Mayur Sudesh, E-mail: anand.s.krishna@gmail.com, E-mail: darak.mayur@gmail.com, E-mail: srk@nitt.edu; Kumar, D. Sriram, E-mail: anand.s.krishna@gmail.com, E-mail: darak.mayur@gmail.com, E-mail: srk@nitt.edu [Department of Electronics and Communication Engineering, National Institute of Technology, Tiruchirappalli 620015 (India)

    2014-10-15

    In this paper, a fluorine-doped tin oxide based optically transparent E-shaped patch antenna is designed and its radiation performance is analyzed in the 705 – 804 GHz band. As optically transparent antennas can be mounted on optical display, they facilitate the reduction of overall system size. The proposed antenna design is simulated using electromagnetic solver - Ansys HFSS and its characteristics such as impedance bandwidth, directivity, radiation efficiency and gain are observed. Results show that the fluorine-doped tin oxide based optically transparent patch antenna overcomes the conventional patch antenna limitations and thus the same can be used for solar cell antenna used in satellite systems.

  15. Dielectric Core-shell Optical Antennas for Strong Solar Absorption Enhancement

    E-Print Network [OSTI]

    Yu, Yiling

    2014-01-01

    Basic  Research  Needs  for  Solar  Energy  Utilization,  Nelson,  J.   Physics  of  Solar  Cell;  Imperial  College  Optical Antennas for Strong Solar Absorption Enhancement

  16. Alcator C-MOD Mini-Proposal Subject: Shoelace Antenna Experimental

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of the QCM, with a coherent fluctuation registering on Phase Contrast Imaging (PCI) chords, polarimeter chords, and Mirnov coils 1, 3. The antenna-driven mode is...

  17. Wireless channel characterization at 2.4 GHz for multiple antenna systems

    E-Print Network [OSTI]

    Wood, Leslie Caroline

    2008-01-01

    Smart antennas for wireless systems," IEEE Personal Commun.and Radio Propagation Models for Wireless MIMO Systems,”EURASIP Journal on Wireless Communications and Networking,

  18. Going green earns Laboratory gold June 18, 2012

    E-Print Network [OSTI]

    - 1 - Going green earns Laboratory gold June 18, 2012 High performance sustainable building attains LEED Gold certification From its robust design to its advanced scientific equipment, the Radiological Laboratory Utility Office Building (RLUOB) is essential to the Lab's national security mission in support

  19. Controlled Bacteria -Gold Nanorod Interactions for Enhancement of Optoacoustic Contrast

    E-Print Network [OSTI]

    Natelson, Douglas

    Controlled Bacteria - Gold Nanorod Interactions for Enhancement of Optoacoustic Contrast Anton as a model of positively charged gold surface for quantitative optoacoustic sensing in GNR-bacteria controlled agglomeration of contrast agents with the bacteria E.Coli and Vibrio Cholerae. For bacterial

  20. Gold nanoparticle assemblies: Interplay between thermal effects and optical response

    E-Print Network [OSTI]

    Boyer, Edmond

    Department of Physics, University of Sistan and Baluchistan, Zahedan, Iran c Université Paris Sorbonne-order nonlinear properties of gold nanoparticles: The influence of the generalized thermal lens in the long laser of an embedded gold nanoparticle subsequent to ultrafast pulsed laser excitation. 1. Introduction The remarkable

  1. Boiler Gold Rush Prof. Johnny Brown (MATH 700)

    E-Print Network [OSTI]

    Brown, Johnny E.

    Boiler Gold Rush Prof. Johnny Brown (MATH 700) jeb@math.purdue.edu #12;#12;#12;David McCullough, Jr help Always be prepared #12;Boiler Gold Rush Prof. Johnny Brown (MATH 700) jeb@math.purdue.edu #12;

  2. Intense emission of cluster anions from gold targets under impact of keV/u gold clusters.

    E-Print Network [OSTI]

    Boyer, Edmond

    Intense emission of cluster anions from gold targets under impact of keV/u gold clusters. M the emission yield of anionic clusters increases much faster with n than expected from simple proportionality. Accordingly, the most intense emission is observed for Au7 - : under Au9 + impact the Au7 - yield per incident

  3. A revolutionary concept to improve the efficiency of IC antennas

    SciTech Connect (OSTI)

    Milanesio, D.; Maggiora, R. [Politecnico di Torino, Dipartimento di Elettronica e Telecomunicazioni (DET), Torino (Italy)

    2014-02-12

    The successful design of an Ion Cyclotron (IC) antenna mainly relies on the capability of coupling high power to the plasma (MW), feature that is currently reached by allowing rather high voltages (tens of kV) on the unavoidable unmatched part of the feeding lines. This requirement is often responsible of arcs along the transmission lines and other unwanted phenomena that considerably limit the usage of IC launchers. In this work, we suggest and describe a revolutionary approach based on high impedance surfaces, which allows to increase the antenna radiation efficiency and, hence, to highly reduce the imposed voltages to couple the same level of power to the plasma. High-impedance surfaces are periodic metallic structures (patches) displaced usually on top of a dielectric substrate and grounded by means of vertical posts usually embedded inside a dielectric, in a mushroom-like shape. In terms of working properties, high impedance surfaces are electrically thin in-phase reflectors, i.e. they present a high impedance, within a given frequency band, such that the image currents are in-phase with the currents of the antenna itself, thus determining a significant efficiency increase. While the usual design of a high impedance surface requires the presence of a dielectric layer, some alternative solutions can be realized in vacuum, taking advantage of double layers ofmetallic patches. After an introductory part on the properties of high impedance surfaces, this work documents both their design by means of numerical codes and their implementation on a scaled mock-up.

  4. The circular loop antenna over a lossy dielectric slab 

    E-Print Network [OSTI]

    Overly, Michael Robert

    1984-01-01

    antenna above a lossy dielectric slab has applicat1ons in undergraound communications/direction find1ng and in the hyperthermic treatment of cancer tumors. Integral equations are derived through the enforcement of boundary conditions at the material... tumor's temperature: lavaersion in a heated liqu1d, irradiation with ultrason1c waves, and the use of perspiration-prevent1ng garments. It is a fact [6]-[9] that the environment inside a tumor enhances its susceptibility to the cytotoxic effects...

  5. constructed and measured. These very small antennas ( /5 per /9 at low frequency limit) present good radiation performances over

    E-Print Network [OSTI]

    Ziolkowski, Richard W.

    . REFERENCES 1. J. Kim, Design of an ultra wide-band printed monopole antenna using FDTD and genetic algoritm

  6. A New Candidate Active Antenna Design for the Long Wavelength Array

    E-Print Network [OSTI]

    Ellingson, Steven W.

    blade design in the LWA project. The fork antenna is a simpler design than the big blade, and could cost blade, is a dipole-like structure, but it is a simpler design. The radiating elements on the big blade1 A New Candidate Active Antenna Design for the Long Wavelength Array Nagini Paravastu (ASEE

  7. On the antenna calibration of space radio instruments using the galactic background: General formulas

    E-Print Network [OSTI]

    California at Berkeley, University of

    and application to STEREO/WAVES, Radio Sci., 46, RS2008, doi:10.1029/2010RS004464. 1. Introduction [2] Radio apply these rela- tions to the antenna calibration of the STEREO/WAVES (S/WAVES) radio instrumentOn the antenna calibration of space radio instruments using the galactic background: General

  8. Design of a Multi-element Multi-polarized Antenna that enables applications based on

    E-Print Network [OSTI]

    Nehorai, Arye

    Design of a Multi-element Multi-polarized Antenna that enables applications based on polarization Cube n HFSS Design n Results n Conclusion Hayvaci, Elnour, Erricolo ­ Design of a Multi-element Multi communications and sensing. Hayvaci, Elnour, Erricolo ­ Design of a Multi-element Multi-polarized Antenna

  9. PHYSICAL REVIEW B 88, 205106 (2013) Fano resonances in antennas: General control over radiation patterns

    E-Print Network [OSTI]

    2013-01-01

    (ITMO), St. Petersburg 197101, Russia 3 Nonlinear Physics Center, Research School of Physics of radio-frequency antennas formulated around the middle of the 20th century. The first decade of the 21st. For this reason, several research teams turn their attention to the study of all-dielectric antennas

  10. Characterization of Graphene-based Nano-antennas in the Terahertz Band

    E-Print Network [OSTI]

    Politècnica de Catalunya, Universitat

    Characterization of Graphene-based Nano-antennas in the Terahertz Band (Invited Paper) Ignacio and Communication Technology, KTH Royal Institute of Technology, 16640 Kista, Sweden Email: lemme@kth.se Abstract--Graphene communications at the nanoscale. Indeed, graphene- based nano-antennas just a few micrometers in size have been

  11. Non-Intrusive Cognitive Radio Networks based on Smart Antenna Technology

    E-Print Network [OSTI]

    Liu, Xin

    spectral efficiency. We investigate a flexible non-intrusive cognitive radio network based on smart antenna to the primary receiver (PR) is either minimized or constrained. Combined with transmission power controlNon-Intrusive Cognitive Radio Networks based on Smart Antenna Technology Senhua Huang, Zhi Ding

  12. UHF Solar Powered Active Oscillator Antenna on Low Cost Flexible Substrate for Wireless Identification Applications

    E-Print Network [OSTI]

    Tentzeris, Manos

    UHF Solar Powered Active Oscillator Antenna on Low Cost Flexible Substrate for Wireless antenna using low cost flexible substrate materials is presented. Flexible amorphous silicon a-Si solar nature of the circuit and providing operational autonomy by harvesting solar power without affecting

  13. Using antennas separated in flight direction to avoid effect of emitter clock drift in geolocation

    DOE Patents [OSTI]

    Ormesher, Richard C.; Bickel, Douglas L

    2012-10-23

    The location of a land-based radio frequency (RF) emitter is determined from an airborne platform. RF signaling is received from the RF emitter via first and second antennas. In response to the received RF signaling, signal samples for both antennas are produced and processed to determine the location of the RF emitter.

  14. Crew Engineering Evaluation of the A1 ray E Antenna Aiming Mechanism

    E-Print Network [OSTI]

    Rathbun, Julie A.

    Crew Engineering Evaluation of the A1 ray E Antenna Aiming Mechanism Engineering Model fATM-1051 PAGE 1 OF DATE 8 /13/7 1 This ATM documents the Bx.A Crew Engineering evaluation of the Array E Antenna Aiming Mechanism Engineering Model. /"/ /-;' ,/'7ji /7 / Prepared byC'f-

  15. Proposal of an Arc Detection Technique Based on RF Measurements for the ITER ICRF Antenna

    SciTech Connect (OSTI)

    Huygen, S.; Dumortier, P.; Durodie, F.; Messiaen, A.; Vervier, M.; Vrancken, M.

    2011-12-23

    RF arc detection is a key operational and safety issue for the ICRF system on ITER. Indeed the high voltages inside the antenna put it at risk of arcing, which could cause substantial damage. This paper describes the various possibilities explored by circuit simulation and the strategy now considered to protect the ITER ICRF antenna from RF arcs.

  16. Multiple Exciton Coherence Sizes in Photosynthetic Antenna Complexes viewed by Pump-Probe Spectroscopy

    E-Print Network [OSTI]

    Mukamel, Shaul

    Multiple Exciton Coherence Sizes in Photosynthetic Antenna Complexes viewed by Pump, 1996X The pump-probe signal from the light-harvesting antenna LH2 of purple bacteria is analyzed using absorption,4,5 pump-probe,11-16 and three pulse echoes.8,17 These measurements show ultrafast energy transfer

  17. Published in IET Microwaves, Antennas & Propagation Received on 28th April 2012

    E-Print Network [OSTI]

    Tentzeris, Manos

    deterioration and stress fractures over the structures lifetime. To remain in service for long periods of time. However, these methods are expensive to implement on a large scale because of the labour and wiring costs, which use patch antennas for stress and crack sensing in structures. In [2], a patch antenna

  18. Directional versus Omnidirectional Antennas for Energy Consumption and k-Connectivity of

    E-Print Network [OSTI]

    Kranakis, Evangelos

    Directional versus Omnidirectional Antennas for Energy Consumption and k-Connectivity of Networks of directional antennas so that the energy consumption required to maintain k-connectivity of the re- sulting]). Sensor nodes enable autonomy, self-configurability, and self-awareness, in the sense that they can

  19. Optical antennas are devices designed to efficiently convert optical radiation into local-

    E-Print Network [OSTI]

    Novotny, Lukas

    Optical antennas are devices designed to efficiently convert optical radiation into local- ized the potential to boost the effi- ciency of optoelectronic devices ranging from light-emitting diodes to solar- ing data describe the spatial­spectral evolu- tion of characteristic antenna resonances

  20. 1 mil gold bond wire study.

    SciTech Connect (OSTI)

    Huff, Johnathon; McLean, Michael B.; Jenkins, Mark W.; Rutherford, Brian Milne

    2013-05-01

    In microcircuit fabrication, the diameter and length of a bond wire have been shown to both affect the current versus fusing time ratio of a bond wire as well as the gap length of the fused wire. This study investigated the impact of current level on the time-to-open and gap length of 1 mil by 60 mil gold bond wires. During the experiments, constant current was provided for a control set of bond wires for 250ms, 410ms and until the wire fused; non-destructively pull-tested wires for 250ms; and notched wires. The key findings were that as the current increases, the gap length increases and 73% of the bond wires will fuse at 1.8A, and 100% of the wires fuse at 1.9A within 60ms. Due to the limited scope of experiments and limited data analyzed, further investigation is encouraged to confirm these observations.

  1. Gold is the most valued of metals. Throughout history it has played a key role

    E-Print Network [OSTI]

    Hutter, Frank

    communities. Today in developing countries, communities living in extreme poverty rely on artisanal gold

  2. Antenna mechanism of length control of actin cables

    E-Print Network [OSTI]

    Lishibanya Mohapatra; Bruce L. Goode; Jane Kondev

    2015-05-02

    Actin cables are linear cytoskeletal structures that serve as tracks for myosin-based intracellular transport of vesicles and organelles in both yeast and mammalian cells. In a yeast cell undergoing budding, cables are in constant dynamic turnover yet some cables grow from the bud neck toward the back of the mother cell until their length roughly equals the diameter of the mother cell. This raises the question: how is the length of these cables controlled? Here we describe a novel molecular mechanism for cable length control inspired by recent experimental observations in cells. This antenna mechanism involves three key proteins: formins, which polymerize actin, Smy1 proteins, which bind formins and inhibit actin polymerization, and myosin motors, which deliver Smy1 to formins, leading to a length-dependent actin polymerization rate. We compute the probability distribution of cable lengths as a function of several experimentally tuneable parameters such as the formin-binding affinity of Smy1 and the concentration of myosin motors delivering Smy1. These results provide testable predictions of the antenna mechanism of actin-cable length control.

  3. Guided Self-Assembly of Gold Thin Films

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Guided Self-Assembly of Gold Thin Films Print Nanoparticles-man-made atoms with unique optical, electrical, and mechanical properties-have become key components in many fields of...

  4. Molecular Structure of Water at Gold Electrodes Revealed

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Molecular Structure of Water at Gold Electrodes Revealed Print The structure of liquid water has been intensely studied, but until recently, it has not been clear what happens to...

  5. GOLD--1997 33.1 By Earle B. Amey

    E-Print Network [OSTI]

    Survey (USGS), entered negotiations with 17 Asian and Pacific Rim governments to reduce barriers in gold, and countries in the Pacific region have the potential for the occurrence of this type of deposit (Wilburn, 1998

  6. Enhancement of in vitro Translation by Gold Nanoparticle – DNA Conjugates

    E-Print Network [OSTI]

    Park, Sunho

    Gold nanoparticle (AuNP)?DNA conjugates can enhance in vitro translation of a protein. Enhancement occurs via a combination of nonspecific adsorption of translation-related molecules and the ribosome to the AuNP?DNA and ...

  7. Effect of ligand on thermal dissipation from gold nanorods

    E-Print Network [OSTI]

    Alper, Joshua

    Thermal interface conductance was measured for soluble gold nanorods (NRs) coated with mercaptocarboxylic acids (HS-(CH[subscript 2])[subscript n]COOH, n = 5, 10, 15), thiolated polyethylene glycols (MW = 356, 1000, 5000), ...

  8. And The Truth Shall Be Read In Gold 

    E-Print Network [OSTI]

    Evans, Terry; Foster, Donna; Slattery, Peter

    1982-01-01

    of nanocomposites. Experimental results showed that the mechanical properties of nanocomposites measured at macroscale exhibited differences when the shape and size of gold NPs were changed. The morphological characteristics of the material were shown effectively...

  9. (Data in metric tons of gold content unless otherwise noted)

    E-Print Network [OSTI]

    , expansion projects, and development projects were placed on hold because of the drop in the price of gold,140 8,140 Price, dollars per troy ounce 4 975 1,228 1,572 1,673 1,400 Employment, mine and mill, number, and Issues: The estimated gold price in 2013 was 16% lower than the price in 2012. This was the first time

  10. Designing for Sustainability: Houston DOW Center LEED Gold 

    E-Print Network [OSTI]

    McCall, H.; McVey, K.; Rash, A.

    2010-01-01

    for Sustainability Houston Dow Center - LEED Gold Heidi McCall Kevin McVey Adam Rash Designing for Sustainability Houston Dow Center About Dow ? Largest diversified chemical company in the world ? Founded in Midland, Michigan in 1897 ? Supplies more than 5... & Office Facilities Management Technology Center Front-end Loading Energy Reporting Implementation Methodology Goals & Technology Senior Leadership Support Key Elements of HDC?s LEED Gold Construction and Commissioning Change Management...

  11. Equivalent radii of antennas with noncircular cross section 

    E-Print Network [OSTI]

    Su, Charles Wen-Hsun

    1960-01-01

    ~ aizi-z~gz&'&z p(WI-~)&+] PgL Assuming that a point generator maintaini'ng a potential difference QV V. across the input terzninals. since () I() z ? 6 ? when current is 1 only in Z-direction s-j WC P oIZ aAa(?) =- ~z Vsz& -az ) ~ aAZ(-S ~ ' V C... If the antenna under consideration is symmetrical with respect to its center in such a way that the following symmetrical conditions can be satisfied: I (Z) e I (-Z), and A (+Z) e A (-Z) s' K s s Also Then equation (6) can be written as: Az=-~l z ~p, Z, g...

  12. High-frequency electric field measurement using a toroidal antenna

    DOE Patents [OSTI]

    Lee, Ki Ha (Lafayette, CA)

    2002-01-01

    A simple and compact method and apparatus for detecting high frequency electric fields, particularly in the frequency range of 1 MHz to 100 MHz, uses a compact toroidal antenna. For typical geophysical applications the sensor will be used to detect electric fields for a wide range of spectrum starting from about 1 MHz, in particular in the frequency range between 1 to 100 MHz, to detect small objects in the upper few meters of the ground. Time-varying magnetic fields associated with time-varying electric fields induce an emf (voltage) in a toroidal coil. The electric field at the center of (and perpendicular to the plane of) the toroid is shown to be linearly related to this induced voltage. By measuring the voltage across a toroidal coil one can easily and accurately determine the electric field.

  13. High-frequency electric field measurement using a toroidal antenna

    SciTech Connect (OSTI)

    Lee, K.H.

    1997-01-01

    In this paper the author describes an innovative method of measuring high-frequency electric fields using a toroid. For typical geophysical applications the new sensor will detect electric fields for a wide range of spectrum starting from 1.0 MHz. This window, in particular the lower frequency range between 1.0 to 100 MHz, has not been used for existing electromagnetic or radar systems to detect small objects in the upper few meters of the ground. Ground penetrating radar (GPR) can be used successfully in this depth range if the ground is resistive but most soils are, in fact, conductive (0.01 to 1.0 S/m) rendering GPR inefficient. Other factors controlling the resolution of GPR system for small objects is the spatial averaging inherent in the electric dipole antenna and the scattering caused by soil inhomogeneities of dimensions comparable to the wavelength (and antenna size). For maximum resolution it is desirable to use the highest frequencies but the scattering is large and target identification is poor. Time-varying magnetic fields induce an emf (voltage) in a toroid. The electric field at the center of the toroid is shown to be linearly related to this induced voltage. By measuring the voltage across a toroid one can easily and accurately determine the electric field. The new sensor will greatly simplify the cumbersome procedure involved with GPR measurements with its center frequency less than 100 MHz. The overall size of the toroidal sensor can be as small as a few inches. It is this size advantage that will not only allow easy fabrication and deployment of multi-component devices either on the surface or in a borehole, but it will render greatly improved resolution over conventional systems.

  14. Superconducting nanowire single-photon detectors integrated with optical nano-antennae

    E-Print Network [OSTI]

    Berggren, Karl K.

    Optical nano-antennae have been integrated with semiconductor lasers to intensify light at the nanoscale and photodiodes to enhance photocurrent. In quantum optics, plasmonic metal structures have been used to enhance ...

  15. Mid-Infrared Single-Photon Detection Using Superconducting Nanowires Integrated with Nano-Antennae

    E-Print Network [OSTI]

    Berggren, Karl K.

    We present some major challenges of mid-infrared superconducting nanowire single-photon detector technology and our device design with nano-antenna integration to address these challenges.

  16. Measurement and Analysis of Multiband Mobile Antennas for Portable Radio Applications

    E-Print Network [OSTI]

    Ellingson, Steven W.

    (806-896 MHz) bands. A summary of the characteristics of this antenna provided by the vendor appear Black Weight (Pounds) 1.6 Mast Appearance Center Mast with Extensions Mounting Style Magnet Mount

  17. Proceedings ofAsia-Pacific Microwave Conference 2007 Conformal Antennas on Liquid Crystalline Polymer

    E-Print Network [OSTI]

    Swaminathan, Madhavan

    Proceedings ofAsia-Pacific Microwave Conference 2007 Conformal Antennas on Liquid Crystalline Abstract- Recent developments in Liquid Crystalline Polymer (LCP) based processing technology showed, and low substrate isolation due to semi-conducting attributes. Recent developments in Liquid Crystalline

  18. Spontaneous hot-electron light emission from electron-fed optical antennas

    E-Print Network [OSTI]

    Buret, Mickael; Dellinger, Jean; Cazier, Nicolas; Mennemanteuil, Marie-Maxime; Berthelot, Johann; Smetanin, Igor V; Protsenko, Igor E; Colas-des-Francs, Gérard; Bouhelier, Alexandre

    2015-01-01

    Nanoscale electronics and photonics are among the most promising research areas providing functional nano-components for data transfer and signal processing. By adopting metal-based optical antennas as a disruptive technological vehicle, we demonstrate that these two device-generating technologies can be interfaced to create an electronically-driven self-emitting unit. This nanoscale plasmonic transmitter operates by injecting electrons in a contacted tunneling antenna feedgap. Under certain operating conditions, we show that the antenna enters a highly nonlinear regime in which the energy of the emitted photons exceeds the quantum limit imposed by the applied bias. We propose a model based upon the spontaneous emission of hot electrons that correctly reproduces the experimental findings. The electron-fed optical antennas described here are critical devices for interfacing electrons and photons, enabling thus the development of optical transceivers for on-chip wireless broadcasting of information at the nanos...

  19. Antenna arrays for the downlink of FDD wideband CDMA communication systems 

    E-Print Network [OSTI]

    Koutalos, Antonios C

    The main subject of this thesis is the investigation of antenna array techniques for improving the performance of the downlink of wideband code division multiple access (WCDMA) mobile communication systems. These ...

  20. In-flight calibration of STEREO-B/WAVES antenna system

    E-Print Network [OSTI]

    Panchenko, M; Rucker, H O; Fischer, G; Oswald, T H; Cecconi, B; Maksimovic, M

    2015-01-01

    The STEREO/WAVES (SWAVES) experiment on board the two STEREO spacecraft (Solar Terrestrial Relations Observatory) launched on 25 October 2006 is dedicated to the measurement of the radio spectrum at frequencies between a few kilohertz and 16 MHz. The SWAVES antenna system consists of 6 m long orthogonal monopoles designed to measure the electric component of the radio waves. With this configuration direction finding of radio sources and polarimetry (analysis of the polarization state) of incident radio waves is possible. For the evaluation of the SWAVES data the receiving properties of the antennas, distorted by the radiation coupling with the spacecraft body and other onboard devices, have to be known accurately. In the present context, these properties are described by the antenna effective length vectors. We present the results of an in-flight calibration of the SWAVES antennas using the observations of the nonthermal terrestrial auroral kilometric radiation (AKR) during STEREO roll maneuvers in an early s...

  1. A Non-Pyramidal Rectangular-to-Trough Waveguide Transition and Pattern Reconfigurable Trough Waveguide Antenna 

    E-Print Network [OSTI]

    Loizou, Loizos

    2012-02-14

    , rods, dielectrics, and other structures can create reconfigurable periodic line sources. These trough waveguide antennas (TWA) are then capable of providing both fixedfrequency and frequency-dependent beam steering. This was originally performed using...

  2. Robotic localization of hostile networked radio sources with a directional antenna 

    E-Print Network [OSTI]

    Hu, Qiang

    2007-04-25

    propose a scheme to localize hostile networked radio sources based on the radio signal strength and communication protocol pattern analysis using a mobile robot with a directional antenna. We integrate a Particle Filter algorithm with a new sensing model...

  3. Porcelain-coated antenna for radio-frequency driven plasma source

    DOE Patents [OSTI]

    Leung, Ka-Ngo (Hercules, CA); Wells, Russell P. (Kensington, CA); Craven, Glen E. (Fremont, CA)

    1996-01-01

    A new porcelain-enamel coated antenna creates a clean plasma for volume or surface-conversion ion sources. The porcelain-enamel coating is hard, electrically insulating, long lasting, non fragile, and resistant to puncture by high energy ions in the plasma. Plasma and ion production using the porcelain enamel coated antenna is uncontaminated with filament or extraneous metal ion because the porcelain does not evaporate and is not sputtered into the plasma during operation. Ion beams produced using the new porcelain-enamel coated antenna are useful in ion implantation, high energy accelerators, negative, positive, or neutral beam applications, fusion, and treatment of chemical or radioactive waste for disposal. For ion implantation, the appropriate species ion beam generated with the inventive antenna will penetrate large or small, irregularly shaped conducting objects with a narrow implantation profile.

  4. Porcelain-coated antenna for radio-frequency driven plasma source

    DOE Patents [OSTI]

    Leung, K.N.; Wells, R.P.; Craven, G.E.

    1996-12-24

    A new porcelain-enamel coated antenna creates a clean plasma for volume or surface-conversion ion sources. The porcelain-enamel coating is hard, electrically insulating, long lasting, non fragile, and resistant to puncture by high energy ions in the plasma. Plasma and ion production using the porcelain enamel coated antenna is uncontaminated with filament or extraneous metal ions because the porcelain does not evaporate and is not sputtered into the plasma during operation. Ion beams produced using the new porcelain-enamel coated antenna are useful in ion implantation, high energy accelerators, negative, positive, or neutral beam applications, fusion, and treatment of chemical or radioactive waste for disposal. For ion implantation, the appropriate species ion beam generated with the inventive antenna will penetrate large or small, irregularly shaped conducting objects with a narrow implantation profile. 8 figs.

  5. 0.6-M ANTENNAE FOR THE AMIBA INTERFEROMETER ARRAY Patrick Koch(1)

    E-Print Network [OSTI]

    Koch, Patrick

    Background Anisotropy (AMiBA) is a hexapod telescope for astronomy. The fully steerable platform can.6 m antennae are being installed, aiming at first scientific results. Mechanical aspects of hexapod

  6. Adaptive and Dynamic Wireless Routers with Smart Antenna for Power Management

    E-Print Network [OSTI]

    Krishnan, S Venkata; Kumar, N Senthil

    2012-01-01

    In the recent evolution of wireless technologies, the power management has been a worrying factor. In order to overcome the power shortage, steps are taken to find new kind of energy harvesting methods, power attenuation reduction methods and power saving techniques. Wireless routers even though consume not much of power, battery powered devices require a lot. Omni directional antenna embedded with multiple antennae focusing the beam of radio wave signals in the direction of nodes with least transmission angle can be a solution for this problem which is called as "Smart Antenna". To reduce power maceration we are going for adaptive and dynamic transmission wherein the transmission angle of antennae is varied in accordance with the movement of nodes. Apart from saving the power considerably, it also improves the signal strength

  7. A Compact Dual-/Multi-Band Wireless LAN Antenna Nader Behdad' and Kamal Sarabandi

    E-Print Network [OSTI]

    Sarabandi, Kamal

    to the Internet is becoming a necessity oflife much faster than cell phones became an essential part of our day are similar to each other and hence, the antenna has similar radiation characteristics at both bands. 0

  8. Propagation models for multiple-antenna systems : methodology, measurements and statistics

    E-Print Network [OSTI]

    Herring, Keith, 1981-

    2008-01-01

    The trend in wireless communications is towards utilization of multiple antenna systems. While techniques such as beam-forming and spatial diversity have been implemented for some time, the emergence of Multiple-Input ...

  9. Improvement in thermal barriers to intense terahertz generation from photoconductive antennas

    SciTech Connect (OSTI)

    Ropagnol, X.; Bouvier, Marcel; Reid, M.; Ozaki, T.

    2014-07-28

    We study the generation of free-space terahertz (THz) pulses at low THz frequencies using 6H-SiC and 4H-SiC photoconductive antennas. We investigate the dependence of the THz electric field radiated from the biased SiC emitters on the applied bias field and on the incident optical fluence. In this work, bias fields as high as 32?kV/cm, and optical fluences up to 2.5?mJ/cm{sup 2} (for the 400?nm laser), and 7.5?mJ/cm{sup 2} (for the 800?nm laser) were used. THz generation with back- and front-side illumination of the antennas is also examined. It is found that the SiC antenna, when illuminated from the backside, generates higher THz electric fields. The performance of 6H-SiC and ZnSe photoconductive antennas are compared. We show that, taking advantage of the superior thermal properties of SiC compare with ZnSe, the THz output power generated with the 6H-SiC photoconductive antenna under optimum conditions is 2.3 times larger that with a ZnSe photoconductive antenna.

  10. The processes of industrial gold mining and inequality: a Ghanaian case study 

    E-Print Network [OSTI]

    Gawor, Natalie

    2011-11-24

    The research examined how inequality manifests itself through the processes of industrial gold mining using a case study of Newmont Mining Corporations’ Ahafo Gold Mine in Ghana. The pursuit of neoliberal development and widespread transnational...

  11. Interaction of amphiphilic gold nanoparticles with lipid membranes and their application to cancer radiotherapy

    E-Print Network [OSTI]

    Yang, Yu-Sang

    2013-01-01

    Striped gold nanoparticles (NPs), inorganic particles protected by an amphiphilic mixed organic ligand shell, are the most recent and potent evolution of gold nanoparticle intracellular delivery vectors. Here we propose ...

  12. Solar Companies Go for the Gold with SunShot Incubator | Department...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Solar Companies Go for the Gold with SunShot Incubator Solar Companies Go for the Gold with SunShot Incubator July 26, 2012 - 9:45am Addthis William Parish from Solar Mosaic, one...

  13. Biomedical Applications of Gold Nanoparticles Functionalized Using Hetero-Bifunctional Poly(ethylene glycol) Spacer

    E-Print Network [OSTI]

    Sridhar, Srinivas

    Biomedical Applications of Gold Nanoparticles Functionalized Using Hetero-Bifunctional Poly potential, circulation time, and the flexibility of surface-attached biomedically-relevant ligands on gold varieties of nanoparticles with biomedical relevance are available including, polymeric nanoparticles, metal

  14. Method for forming gold-containing catalyst with porous structure

    SciTech Connect (OSTI)

    Biener, Juergen; Hamza, Alex V; Baeumer, Marcus; Schulz, Christian; Jurgens, Birte; Biener, Monika M.

    2014-07-22

    A method for forming a gold-containing catalyst with porous structure according to one embodiment of the present invention includes producing a starting alloy by melting together of gold and at least one less noble metal that is selected from the group consisting of silver, copper, rhodium, palladium, and platinum; and a dealloying step comprising at least partial removal of the less noble metal by dissolving the at least one less noble metal out of the starting alloy. Additional methods and products thereof are also presented.

  15. Gutierrez and Orsi, eds.: Contested Eden: California Before the Gold Rush

    E-Print Network [OSTI]

    Farris, Glenn J.

    1999-01-01

    the Gold Rush. Ramon A. Gutierrez and Richard J. Orsi, eds.of Califomia histoty. Gutierrez then sets about introducing

  16. Blue and Gold Society Please Submit requests at least two weeks prior

    E-Print Network [OSTI]

    Jiang, Huiqiang

    Blue and Gold Society Please Submit requests at least two weeks prior to your event date Today: ____________________________ ___________________________________________ ___________________________________________ ___________________________________________ Assistance Required Number of Blue and Gold members needed: _______ Arrival Time: __: __ Departing Time: __: __ Blue and Gold Society attire: Formal (suit) Casual (rugby shirt) Other Any Additional Information

  17. welcome to university residences Boiler Gold Rush Check-In...........................Saturday, August 13 and

    E-Print Network [OSTI]

    Fernández-Juricic, Esteban

    welcome to university residences #12;Boiler Gold Rush Check-In...........................Saturday, August 13 and Sunday, August 14, 2011 Boiler Gold Rush residence hall systems in the United States. weLcomE! 1 #12;Boiler GoLD Rush ParticiPants Your regular

  18. The Digital Motion Control System for the Submillimeter Array Antennas

    E-Print Network [OSTI]

    Hunter, T R; Kimberk, R; Leiker, P S; Patel, N A; Blundell, R; Christensen, R D; Diven, A R; Maute, J; Plante, R J; Riddle, P; Young, K H

    2013-01-01

    We describe the design and performance of the digital servo and motion control system for the 6-meter diameter parabolic antennas of the Submillimeter Array (SMA) on Mauna Kea, Hawaii. The system is divided into three nested layers operating at a different, appropriate bandwidth. (1) A rack-mounted, real-time Unix system runs the position loop which reads the high resolution azimuth and elevation encoders and sends velocity and acceleration commands at 100 Hz to a custom-designed servo control board (SCB). (2) The microcontroller-based SCB reads the motor axis tachometers and implements the velocity loop by sending torque commands to the motor amplifiers at 558 Hz. (3) The motor amplifiers implement the torque loop by monitoring and sending current to the three-phase brushless drive motors at 20 kHz. The velocity loop uses a traditional proportional-integral-derivative (PID) control algorithm, while the position loop uses only a proportional term and implements a command shaper based on the Gauss error functi...

  19. RF Arc Detection in ICRH RDL Antennas by Phase Measurement

    SciTech Connect (OSTI)

    El Khaldi, M.; Vulliez, K.; Magne, R.; Bosia, G.

    2009-11-26

    A voltage breakdown in an Ion Cyclotron Resonance Heating (ICRH) system is usually detected as an abrupt change in the module of the reflection coefficient |{gamma}in| at the power source output. The same effect can be due to a large load variation. This study is carried out by constructing a electrical model for a Tore Supra ITER-like antenna (TS ILA), and to analyse how a voltage breakdown, localized in any part of the system, modifies several electrical parameters of the circuit (with respect to perfect match conditions), as detected at the location of the monitoring points. The phase difference between the reflections coefficients measured at the output of tuning network when an arc strikes in one of two Resonant double loop (RDL) sections of the ICRH TS ILA appears to be the most promising parameter to detect the arc and identify its position. It is also significantly insensitive to a load variation so an arc and edge localized modes (ELMs) can be distinguished.

  20. Characterization and performance of a field aligned ion cyclotron range of frequency antenna in Alcator C-Mod

    SciTech Connect (OSTI)

    Wukitch, S. J.; Garrett, M. L.; Ochoukov, R.; Terry, J. L.; Hubbard, A.; Labombard, B.; Lau, C.; Lin, Y.; Lipschultz, B.; Miller, D.; Reinke, M. L.; Whyte, D.; Collaboration: Alcator C-Mod Team

    2013-05-15

    Ion cyclotron range of frequency (ICRF) heating is expected to provide auxiliary heating for ITER and future fusion reactors where high Z metallic plasma facing components (PFCs) are being considered. Impurity contamination linked to ICRF antenna operation remains a major challenge particularly for devices with high Z metallic PFCs. Here, we report on an experimental investigation to test whether a field aligned (FA) antenna can reduce impurity contamination and impurity sources. We compare the modification of the scrape of layer (SOL) plasma potential of the FA antenna to a conventional, toroidally aligned (TA) antenna, in order to explore the underlying physics governing impurity contamination linked to ICRF heating. The FA antenna is a 4-strap ICRF antenna where the current straps and antenna enclosure sides are perpendicular to the total magnetic field while the Faraday screen rods are parallel to the total magnetic field. In principle, alignment with respect to the total magnetic field minimizes integrated E|| (electric field along a magnetic field line) via symmetry. A finite element method RF antenna model coupled to a cold plasma model verifies that the integrated E|| should be reduced for all antenna phases. Monopole phasing in particular is expected to have the lowest integrated E||. Consistent with expectations, we observed that the impurity contamination and impurity source at the FA antenna are reduced compared to the TA antenna. In both L and H-mode discharges, the radiated power is 20%–30% lower for a FA-antenna heated discharge than a discharge heated with the TA-antennas. However, inconsistent with expectations, we observe RF induced plasma potentials (via gas-puff imaging and emissive probes to be nearly identical for FA and TA antennas when operated in dipole phasing). Moreover, the highest levels of RF-induced plasma potentials are observed using monopole phasing with the FA antenna. Thus, while impurity contamination and sources are indeed reduced with the FA antenna configuration, the mechanism determining the SOL plasma potential in the presence of ICRF and its impact on impurity contamination and sources remains to be understood.

  1. Securing Wireless Data Networks against Eavesdropping Using Smart Antennas Sriram Lakshmanan, Cheng-Lin Tsao, Raghupathy Sivakumar

    E-Print Network [OSTI]

    Sivakumar, Raghupathy

    Securing Wireless Data Networks against Eavesdropping Using Smart Antennas Sriram Lakshmanan, Cheng-Lin Tsao, Raghupathy Sivakumar Georgia Institute of Technology Atlanta,GA,USA {sriram

  2. Influence of gas injection location and magnetic perturbations on ICRF antenna performance in ASDEX Upgrade

    SciTech Connect (OSTI)

    Bobkov, V.; Bilato, R.; Dux, R.; Faugel, H.; Kallenbach, A.; Müller, H. W.; Potzel, S.; Pütterich, Th.; Suttrop, W. [Max-Planck-Institut für Plasmaphysik, EURATOM-Association, D-85748 (Germany); Stepanov, I.; Noterdaeme, J.-M. [Max-Planck-Institut für Plasmaphysik, EURATOM-Association, D-85748, Germany and Department of Applied Physics, Gent University, 9000 Gent (Belgium); Jacquet, P.; Monakhov, I. [Euratom/CCFE Fusion Association, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); Colas, L. [CEA, IRFM, 13108 Saint Paul-lez-Durance (France); Czarnecka, A. [Institute of Plasma Physics and Laser Microfusion, Association EURATOM-IPPLM, Warsaw (Poland); Collaboration: ASDEX Upgrade Team

    2014-02-12

    In ASDEX Upgrade H-modes with H{sub 98}?0.95, similar effect of the ICRF antenna loading improvement by local gas injection was observed as previously in L-modes. The antenna loading resistance R{sub a} between and during ELMs can increase by more than 25% after a switch-over from a deuterium rate of 7.5?10{sup 21} D/s injected from a toroidally remote location to the same amount of deuterium injected close to an antenna. However, in contrast to L-mode, this effect is small in H-mode when the valve downstream w.r.t. parallel plasma flows is used. In L-mode, a non-linearity of R{sub a} at P{sub ICRP}<30 kW is observed when using the gas valve integrated in antenna. Application of magnetic perturbations (MPs) in H-mode discharges leads to an increase of R{sub a}>30% with no effect of spectrum and phase of MPs on R{sub a} found so far. In the case ELMs are fully mitigated, the antenna loading is higher and steadier. In the case ELMs are not fully mitigated, the value of R{sub a} between ELMs is increased. Looking at the W source modification for the improved loading, the local gas injection is accompanied by decreased values of tungsten (W) influx ?{sub W} from the limiters and its effective sputtering yield Y{sub w}, with the exception of the locations directly at the antenna gas valve. Application of MPs leads to increase of ?{sub W} and Y{sub w} for some of the MP phases. With nitrogen seeding in the divertor, ICRF is routinely used to avoid impurity accumulation and that despite enhanced ?{sub W} and Y{sub W} at the antenna limiters.

  3. Formation and Characterization of Core Shell Structures on Nanoporous Gold

    E-Print Network [OSTI]

    Collins, Gary S.

    characteristics. Methods To obtain a layer of nickel on the NPG, electroplating in a Watts bath was the best of the nickel plated NPG for reference. 300 nm dealloyed gold ­ basis for plating Electroplating A 250 mL Watts in the calculated time. A nickel rod acted as the cathode. Because electroplating can sometimes not be as uniform

  4. Preparation and Characterization of Polyelectrolyte-Coated Gold Nanoparticles

    E-Print Network [OSTI]

    Barrett, Christopher

    . Consequently, poor polymer coverage can decrease the stability of colloidal suspensions required for many sulfonate) (PSS) via electrostatic self-assembly. The suspension stability, monitored by the gold surface. These differences in stability of the multilayer components and the nanoparticle suspension are rationalized

  5. Sustained Storage and Transport of Hydraulic Gold Mining Sediment

    E-Print Network [OSTI]

    James, L. Allan

    Sustained Storage and Transport of Hydraulic Gold Mining Sediment in the Bear River, California L- sic model of sediment transport in a symmet- rical wave that is based on hydraulic mining sediment primarily in the Yuba Basin. Sus- tained storage and transport of hydraulic min- ing sediment in the Bear

  6. Evaluation of Hypervelocity Gold Nanoparticles for Nanovolume Surface Mass Spectrometry 

    E-Print Network [OSTI]

    DeBord, John 1986-

    2012-08-16

    Impacts of high kinetic energy massive gold clusters (~ 500 keV Au400+4) exhibit significantly enhanced secondary ion yields relative to traditional atomic or polyatomic primary ions (e.g. Au3 and C60). The one-of-a-kind instrument used to generate...

  7. Enhanced radiative heat transfer between nanostructured gold plates

    E-Print Network [OSTI]

    R. Guérout; J. Lussange; F. S. S. Rosa; J. -P. Hugonin; D. A. R. Dalvit; J. -J. Greffet; A. Lambrecht; S. Reynaud

    2012-03-07

    We compute the radiative heat transfer between nanostructured gold plates in the framework of the scattering theory. We predict an enhancement of the heat transfer as we increase the depth of the corrugations while keeping the distance of closest approach fixed. We interpret this effect in terms of the evolution of plasmonic and guided modes as a function of the grating's geometry.

  8. Bandwidth provisioning in infrastructure-based wireless networks employing directional antennas

    SciTech Connect (OSTI)

    Hasiviswanthan, Shiva; Zhao, Bo; Vasudevan, Sudarshan; Yrgaonkar, Bhuvan

    2009-01-01

    Motivated by the widespread proliferation of wireless networks employing directional antennas, we study the problem of provisioning bandwidth in such networks. Given a set of subscribers and one or more access points possessing directional antennas, we formalize the problem of orienting these antennas in two fundamental settings: (1) subscriber-centric, where the objective is to fairly allocate bandwidth among the subscribers and (2) provider-centric, where the objective is to maximize the revenue generated by satisfying the bandwidth requirements of subscribers. For both the problems, we first design algorithms for a network with only one access point working under the assumption that the number of antennas does not exceed the number of noninterfering channels. Using the well-regarded lexicographic max-min fair allocation as the objective for a subscriber-centric network, we present an optimum dynamic programming algorithm. For a provider-centric network, the allocation problem turns out to be NP-hard. We present a greedy heuristic based algorithm that guarantees almost half of the optimum revenue. We later enhance both these algorithms to operate in more general networks with multiple access points and no restrictions on the relative numbers of antennas and channels. A simulation-based evaluation using OPNET demonstrates the efficacy of our approaches and provides us further in insights into these problems.

  9. A comparative study of nano-scale coatings on gold electrodes for bioimpedance studies of breast cancer cells

    E-Print Network [OSTI]

    Heflin, Randy

    with that of gold microelectrodes coated with gold nanoparticles, carbon nanotubes, or electroplated gold to inA comparative study of nano-scale coatings on gold electrodes for bioimpedance studies of breast- troduce nano-scale roughness on the surface of the electrodes. For biological solutions, the electroplated

  10. Influence of gold-silica nanoparticles on the performance of small-molecule bulk heterojunction solar cells

    E-Print Network [OSTI]

    Demir, Hilmi Volkan

    )-silica nanospheres and nanorods embedded in the active layer of small-mole- cule (SM) organic solar cell has been film organic solar cells include the cells with V-shaped (folded) geometry, incoupler at the front sur solar cells Xiaoyan Xu a , Aung Ko Ko Kyaw b , Bo Peng c , Qihua Xiong c , Hilmi Volkan Demir a,c,d , Ye

  11. Lower Bounds on Q for Finite Size Antennas of Arbitrary Shape

    E-Print Network [OSTI]

    Kim, Oleksiy S

    2015-01-01

    The problem of the lower bound on the radiation Q for an arbitrarily shaped finite size antenna of non-zero volume is formulated in terms of equivalent electric and magnetic currents densities distributed on a closed surface coinciding with antenna exterior surface. When these equivalent currents radiate in free space, the magnetic current augments the electric current, so that the fields interior to the surface vanish. In contrast to approaches based solely on electric currents, the proposed technique ensures no stored energy interior to the antenna exterior surface, and thus, allows the fundamental lower bound on Q to be determined. To facilitate the computation of the bound, new expressions for the stored energy, radiated power, and Q of coupled electric and magnetic source currents in free space are derived.

  12. The solution of antenna array input impedances using an alternating current network calculator 

    E-Print Network [OSTI]

    Pool, Jack William

    1963-01-01

    . It has been shown that the equations of n antennas in an array are, E ~ I Z + IbZ b+ I Z a a aa b ab c ac Eb I Zba+ IbZbb+ I Zbc E ~ I Z + I Z + I Z a I Z n cn 4 P E~I Z+IZ+IZ I Z a na b nb c nc n nn' The above equations are identical... the program given in Appendix III, Z Zbb 37'4 + J 21 aa Z bv Zb ~ 20o4 ? ] 14+2+ ab- --ba (3) The equations for a two antenna array are, E~IZ +IbZ a a aa b ab I Zb + IbZbb (4) The ourrents of the antennas were assumed to be ss follows~ I ~ 1. 000 / 0...

  13. BROADBAND ANTENNA MATCHING NETWORK DESIGN AND APPLICATION FOR RF PLASMA ION SOURCE

    SciTech Connect (OSTI)

    Shin, Ki [ORNL; Kang, Yoon W [ORNL; Piller, Chip [ORNL; Fathy, Aly [University of Tennessee, Knoxville (UTK)

    2011-01-01

    The RF ion source at Spallation Neutron Source has been upgraded to meet higher beam power requirement. One important subsystem for efficient operation of the ion source is the 2MHz RF impedance matching network. The real part of the antenna impedance is very small and is affected by plasma density for 2MHz operating frequency. Previous impedance matching network for the antenna has limited tuning capability to cover this potential variation of the antenna impedance since it employed a single tuning element and an impedance transformer. A new matching network with two tunable capacitors has been built and tested. This network can allow precision matching and increase the tunable range without using a transformer. A 5-element broadband matching network also has been designed, built and tested. The 5-element network allows wide band matching up to 50 kHz bandwidth from the resonance center of 2 MHz. The design procedure, simulation and test results are presented.

  14. How Energy Funnels from the Phycoerythrin Antenna Complex to Photosystem I and Photosystem II in Cryptophyte Rhodomonas CS24 Cells

    E-Print Network [OSTI]

    van Stokkum, Ivo

    and mechanisms of light harvesting by isolated photosynthetic light-harvesting antenna complexes.1-3 Indeed, we cryptophyte organism Rhodomonas CS24. The role of phycobiliproteins as primary antenna light- harvesting is the location of the water-soluble phycobilin proteins at the lumenal side of the thylakoid membranes

  15. Abstract--In this paper, we propose a compact internal antenna for modern slim personal communication handsets that

    E-Print Network [OSTI]

    Park, Seong-Ook

    at multiple frequency bands to provide various communication services [1]-[3]. The demand of compact, light.1­5.9 GHz) frequency bands. A prototype antenna is fabricated using a flat copper sheet of 0.2 mm thickness. A prototype antenna is fabricated using a copper sheet of 0.2 mm thickness and bent at the location shown

  16. IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS, VOL. 8, NO. 9, SEPTEMBER 2009 4855 Joint Admission Control and Antenna Assignment

    E-Print Network [OSTI]

    Kim, Dong In

    node (e.g., a wireless mesh router) with multiple antennas. We decompose this RRM problem into twoIEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS, VOL. 8, NO. 9, SEPTEMBER 2009 4855 Joint Admission Control and Antenna Assignment for Multiclass QoS in Spatial Multiplexing MIMO Wireless Networks Dusit

  17. Reconfigurable Multi-Beam Spiral Antenna with RF-MEMS Capacitive Series Switches Fabricated on Rigid Substrates

    E-Print Network [OSTI]

    De Flaviis, Franco

    Reconfigurable Multi-Beam Spiral Antenna with RF-MEMS Capacitive Series Switches Fabricated antenna, which radiates multi-beam with radio frequency-micro electro mechanical system (RF-MEMS.8). The spiral is configured by three-arms, which can be interconnected by two RF-MEMS series switches

  18. Effects of Signal Processing and Antenna Frequency on the Geostatistical Structure of Ground-Penetrating Radar Data

    E-Print Network [OSTI]

    Barrash, Warren

    Effects of Signal Processing and Antenna Frequency on the Geostatistical Structure of Ground with application of signal processing or by changing the signal frequency. We perform geostatistical analyses of surface radar reflection profiles in order to investigate the effects of data processing and antenna

  19. IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS, VOL. 5, 2006 479 Fabrication of a DRA Array Using Ceramic

    E-Print Network [OSTI]

    Sarabandi, Kamal

    Ceramic Stereolithography Amelia Buerkle, Student Member, IEEE, Karl F. Brakora, Student Member, IEEE fabrication of an array of dielectric resonator antennas (DRAs) using ceramic stereolithography. Design, is mainly responsible for losses in the radiating structure. Index Terms--Antenna arrays, ceramic

  20. Efficient Co-design of Composite Smart Structures (Antennas and Mechanical Structures) Using a Novel Hybrid Optimization Technique

    E-Print Network [OSTI]

    Tentzeris, Manos

    Efficient Co-design of Composite Smart Structures (Antennas and Mechanical Structures) Using. Introduction In the recent years, the need for improved structural efficiency and mechanical of a composite roof structure in military vehicles with multiple antennas ensures high electrical performance

  1. Design and Modeling of Novel Multiband/Wideband Antennas for RFID Tags and Readers Using Time-/Frequency-Domain Simulators

    E-Print Network [OSTI]

    Tentzeris, Manos

    environments and standards (US, Europe, Asia) [2]. This paper presents for the first time the design, modeling, in this inductively coupled RFID antenna, the radiated energy is focused directionally in a dumbbell shape as shown is expected to achieve with RFID antennas in such a configuration. Paper is considered one of the best

  2. Minor Complexes at Work: Light-Harvesting by Carotenoids in the Photosystem II Antenna Complexes CP24 and CP26

    E-Print Network [OSTI]

    van Stokkum, Ivo

    Minor Complexes at Work: Light-Harvesting by Carotenoids in the Photosystem II Antenna Complexes CP24 and CP26 Alessandro Marin, Francesca Passarini, Ivo H. M. van Stokkum, Rienk van Grondelle investigated here for the first time, to our knowledge, in the CP26 and CP24 minor antenna complexes

  3. Method of making gold thiolate and photochemically functionalized microcantilevers

    DOE Patents [OSTI]

    Boiadjiev, Vassil I. (Knoxville, TN) [Knoxville, TN; Brown, Gilbert M. (Knoxville, TN) [Knoxville, TN; Pinnaduwage, Lal A. (Knoxville, TN) [Knoxville, TN; Thundat, Thomas G. (Knoxville, TN) [Knoxville, TN; Bonnesen, Peter V. (Knoxville, TN) [Knoxville, TN; Goretzki, Gudrun (Nottingham, GB) [Nottingham, GB

    2009-08-25

    Highly sensitive sensor platforms for the detection of specific reagents, such as chromate, gasoline and biological species, using microcantilevers and other microelectromechanical systems (MEMS) whose surfaces have been modified with photochemically attached organic monolayers, such as self-assembled monolayers (SAM), or gold-thiol surface linkage are taught. The microcantilever sensors use photochemical hydrosilylation to modify silicon surfaces and gold-thiol chemistry to modify metallic surfaces thereby enabling individual microcantilevers in multicantilever array chips to be modified separately. Terminal vinyl substituted hydrocarbons with a variety of molecular recognition sites can be attached to the surface of silicon via the photochemical hydrosilylation process. By focusing the activating UV light sequentially on selected silicon or silicon nitride hydrogen terminated surfaces and soaking or spotting selected metallic surfaces with organic thiols, sulfides, or disulfides, the microcantilevers are functionalized. The device and photochemical method are intended to be integrated into systems for detecting specific agents including chromate groundwater contamination, gasoline, and biological species.

  4. Long-range memory and multifractality in gold markets

    E-Print Network [OSTI]

    Mali, Provash

    2015-01-01

    Long-range correlation and fluctuation in the gold market time series of world's two leading gold consuming countries, namely China and India, are studied. For both the market series during the period 1985-2013 we observe a long-range persistence of memory in the sequences of maxima (minima) of returns in successive time windows of fixed length, but the series as a whole are found to be uncorrelated. Multifractal analysis for these series as well as for the sequences of maxima (minima) is carried out in terms of the multifractal detrended fluctuation analysis (MF-DFA) method. We observe a weak multifractal structure for the original series that is mainly originated from the fat-tailed probability distribution function of the values, and the multifractal nature of the original time series is enriched into their sequences of maximal (minimal) returns. A quantitative measure of multifractality is provided by using a set of "complexity parameters".

  5. Electron energy loss spectroscopy of gold nanoparticles on graphene

    SciTech Connect (OSTI)

    DeJarnette, Drew [Microelectronics and Photonics Graduate Program, University of Arkansas, Fayetteville, Arkansas 72701 (United States); Roper, D. Keith, E-mail: dkroper@uark.edu [Microelectronics and Photonics Graduate Program, University of Arkansas, Fayetteville, Arkansas 72701 (United States); Department of Chemical Engineering, University of Arkansas, Fayetteville, Arkansas 72701 (United States)

    2014-08-07

    Plasmon excitation decay by absorption, scattering, and hot electron transfer has been distinguished from effects induced by incident photons for gold nanoparticles on graphene monolayer using electron energy loss spectroscopy (EELS). Gold nano-ellipses were evaporated onto lithographed graphene, which was transferred onto a silicon nitride transmission electron microscopy grid. Plasmon decay from lithographed nanoparticles measured with EELS was compared in the absence and presence of the graphene monolayer. Measured decay values compared favorably with estimated radiative and non-radiative contributions to decay in the absence of graphene. Graphene significantly enhanced low-energy plasmon decay, increasing mode width 38%, but did not affect higher energy plasmon or dark mode decay. This decay beyond expected radiative and non-radiative mechanisms was attributed to hot electron transfer, and had quantum efficiency of 20%, consistent with previous reports.

  6. Gold-based electrical interconnections for microelectronic devices

    DOE Patents [OSTI]

    Peterson, Kenneth A. (Albuquerque, NM); Garrett, Stephen E. (Albuquerque, NM); Reber, Cathleen A. (Corrales, NM); Watson, Robert D. (Tijeras, NM)

    2002-01-01

    A method of making an electrical interconnection from a microelectronic device to a package, comprising ball or wedge compression bonding a gold-based conductor directly to a silicon surface, such as a polysilicon bonding pad in a MEMS or IMEMS device, without using layers of aluminum or titanium disposed in-between the conductor and the silicon surface. After compression bonding, optional heating of the bond above 363 C. allows formation of a liquid gold-silicon eutectic phase containing approximately 3% (by weight) silicon, which significantly improves the bond strength by reforming and enhancing the initial compression bond. The same process can be used for improving the bond strength of Au--Ge bonds by forming a liquid Au-12Ge eutectic phase.

  7. Idaho National Engineering and Environmental Laboratory Awarded VPP Gold Star

    Broader source: Energy.gov [DOE]

    Our journey to safety excellence began some six (6) years ago. The task seemed ominous with 6000 plus employees ranging from administrative assistants and craftsman to research scientists and engineers. Another challenge was the geographic dispersion of work areas being as much as 50 miles apart. A core group of employees caught the vision and knew that it could be done, and it is that perseverance that has lead the INEEL to the DOE-VPP Gold Star.

  8. Gold Binding by Native and Chemically Modified Hops Biomasses

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    López, M. Laura; Gardea-Torresdey, J. L.; Peralta-Videa, J. R.; de la Rosa, G.; Armendáriz, V.; Herrera, I.; Troiani, H.; Henning, J.

    2005-01-01

    Heavy metals from mining, smelting operations and other industrial processing facilities pollute wastewaters worldwide. Extraction of metals from industrial effluents has been widely studied due to the economic advantages and the relative ease of technical implementation. Consequently, the search for new and improved methodologies for the recovery of gold has increased. In this particular research, the use of cone hops biomass ( Humulus lupulus ) was investigated as a new option for gold recovery. The results showed that the gold binding to native hops biomass was pH dependent from pH 2 to pH 6, with a maximum percentage bindingmore »at pH 3. Time dependency studies demonstrated that Au(III) binding to native and modified cone hops biomasses was found to be time independent at pH 2 while at pH 5, it was time dependent. Capacity experiments demonstrated that at pH 2, esterified hops biomass bound 33.4 mg Au/g of biomass, while native and hydrolyzed hops biomasses bound 28.2 and 12.0 mg Au/g of biomass, respectively. However, at pH 5 the binding capacities were 38.9, 37.8 and 11.4 mg of Au per gram of native, esterified and hydrolyzed hops biomasses, respectively. « less

  9. A Cavity-backed Slot Antenna with High Upper Hemisphere Efficiency for Sewer Sensor Network

    E-Print Network [OSTI]

    Tentzeris, Manos

    A Cavity-backed Slot Antenna with High Upper Hemisphere Efficiency for Sewer Sensor Network of Technology Atlanta, GA Abstract--A wireless sewer sensor network has been widespread to monitor combined sewer overflow (CSO) causing human health and environmental hazards. To enable the wireless

  10. Receiver Antenna Array for a Multichannel Sense-and-Avoid Radar for Small UAVs

    E-Print Network [OSTI]

    Kansas, University of

    Receiver Antenna Array for a Multichannel Sense-and-Avoid Radar for Small UAVs Jose Francisco for use in a sense-and-avoid radar for use in the Cessna C-172 and small Unmanned Aerial Vehicles (UAVs. . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . ..10 1.1.1 Multichannel Sense-and-Avoid Radar for UAVs. . . . . . . . . . . . . . . . . . . . . . ...10

  11. TRUNCATED CHLOROPHYLL ANTENNA SIZE OF THE PHOTOSYSTEMS A PRACTICAL METHOD TO IMPROVE MICROALGAL PRODUCTIVITY AND

    E-Print Network [OSTI]

    Polle, Jürgen

    , Tatsuru Masuda and Anastasios Melis* Department of Plant and Microbial Biology, University of California productivity of a mass culture. A list of genes that confer a "truncated light- harvesting Chl antenna" size or two because of the photosynthetic evolution of oxygen. The latter is a powerful positive suppressor

  12. Linear Precoding for Multi-Antenna CDMA over Multipath ISI Channels

    E-Print Network [OSTI]

    Reynolds, Daryl

    1 Linear Precoding for Multi-Antenna CDMA over Multipath ISI Channels Kirtan N. Modi, Daryl with and without intersymbol interference (ISI). Our receivers are constrained to simple match filters while precoders designed for channels without ISI achieve full diversity gain while completely suppressing

  13. Reliability of Wireless On-Chip Interconnects Based on Carbon Nanotube Antennas

    E-Print Network [OSTI]

    Pande, Partha Pratim

    Reliability of Wireless On-Chip Interconnects Based on Carbon Nanotube Antennas A. Nojeh1 , P Engineering University of British Columbia 2332 Main Mall Vancouver, BC, Canada 2 School of Electrical of the research effort in the emerging area of nanoelectronics has revolved around creating novel devices

  14. Benefits of Multiple Transmit Antennas in Secure Communication: A Secrecy Outage Viewpoint

    E-Print Network [OSTI]

    Zhou, Xiangyun "Sean"

    Benefits of Multiple Transmit Antennas in Secure Communication: A Secrecy Outage Viewpoint Xi Zhang confusing the eavesdrop- per by delivering artificial noise. A recently developed secrecy outage formulation the security performance. We show that an arbitrarily low secrecy outage probability cannot be achieved

  15. ENERGY EFFICIENT MILLIMETER WAVE RADIO LINK ESTABLISHMENT WITH SMART ARRAY ANTENNAS

    E-Print Network [OSTI]

    Baras, John S.

    1 ENERGY EFFICIENT MILLIMETER WAVE RADIO LINK ESTABLISHMENT WITH SMART ARRAY ANTENNAS Behnam of two millimeter wave transceiver nodes A and B. We assume that each node is equipped with a circular. INTRODUCTION Millimeter wave technology is becoming increasingly important in many military and commercial

  16. AN EFFICIENT INTEGRAL TRANSFORM TECHNIQUE OF A SINGULAR WIRE ANTENNA KERNEL

    E-Print Network [OSTI]

    Park, Seong-Ook

    AN EFFICIENT INTEGRAL TRANSFORM TECHNIQUE OF A SINGULAR WIRE ANTENNA KERNEL S.-O. Park Department-348, South of Korea Abstract-This paper presents an efficient integral transform tech- nique for evaluating transforma- tions, the original double integral 1/-Rs with a singular kernal can be represented as a finite

  17. Experimental Evaluation of an Adaptive Antenna for a TDMA Mobile Telephony System

    E-Print Network [OSTI]

    and square kilometre is to introduce adaptive array antennas, where suppression of co-channel interferers multiplexing are then possible. Brief specifications of the adaptive array system are shown in Table I the array performance is improved [3]. Data from the calibration are stored as look-up tables in the DSP

  18. Experimental Evaluation of an Adaptive Antenna for a TDMA Mobile Telephony System

    E-Print Network [OSTI]

    and square kilometre is to introduce adaptive array antennas, where suppression of co­channel interferers multiplexing are then possible. Brief specifications of the adaptive array system are shown in Table I the array performance is improved [3]. Data from the calibration are stored as look­up tables in the DSP

  19. Paper-Based, Inkjet-Printed, Text-Meandered UHF Resonant Antennas for RFID Applications

    E-Print Network [OSTI]

    Tentzeris, Manos

    radiators resonating in the UHF band. The meander lines techniques is exploited in this work the radiator is typically realized with microstrip technology, the choice of the antenna substrate. Materials technology device. The UHF band has nowadays a crucial role for radiofrequency identification, since most

  20. Minimum-Energy Broadcast Using Practical Directional Antennas in All-Wireless Networks

    E-Print Network [OSTI]

    Li, Xiang-Yang

    . Such decentralized networks can enable flexible, infrastructure-less and robust data and service access to support is to adjust the transmission power of individual nodes so as to minimize the overall transmission power]. Using omnidirectional antennas in wireless ad hoc networks can be highly inefficient in terms of power

  1. Special Sensor Microwave Imager and Sounder (SSMIS) Antenna Brightness Temperature Data Record (TDR)

    E-Print Network [OSTI]

    Special Sensor Microwave Imager and Sounder (SSMIS) Antenna Brightness Temperature Data Record (TDR/NESDIS/Center for Satellite Applications and Research Contributors from: Banghua Yan (Lead), QSS/JCSDA Ninghai Sun, IMSG, Metoffice, UK Yong Han, STAR/JCSDA Mark Liu, QSS/JCSDA Distribution to: Ralph Ferrrao, STAR Tom Schott, OSD

  2. IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, VOL. 43, NO. 5, MAY 1995 Backscattering Enhancement and Clustering

    E-Print Network [OSTI]

    Zhang, Guifu

    IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, VOL. 43, NO. 5, MAY 1995 Backscattering Enhancement on Monte-Carlo Simulations Leung Tsang, Fellow, IEEE, Kung-Hau Ding, Member, IEEE, Guifu Zhang, c.C. Hsu, Student Member, IEEE, and Jin Au Kong, Fellow, IEEE Abstract-Backscattering enhancement can exist

  3. IEEE TRANSACTIONS ON COMMUNICATIONS 1 MAP Decoding for Multi-Antenna Systems with

    E-Print Network [OSTI]

    Wehlau, David

    IEEE TRANSACTIONS ON COMMUNICATIONS 1 MAP Decoding for Multi-Antenna Systems with Non-Uniform Sources: Exact Pairwise Error Probability and Applications Firouz Behnamfar, Member, IEEE, Fady Alajaji, Senior Member, IEEE, and Tam´as Linder, Senior Member, IEEE Abstract We study the maximum a posteriori

  4. Coordinated Beamforming for the Multi-Cell Multi-Antenna Wireless System

    E-Print Network [OSTI]

    Yu, Wei

    of the total weighted transmitted power across the base-stations subject to signal of coordinating base-stations across multiple cells in a multi-antenna beamforming system, where multiple base- stations may jointly optimize their respective beamformers to improve the overall system performance

  5. Plasma generation for controlled microwave-reflecting surfaces in plasma antennas

    SciTech Connect (OSTI)

    Bliokh, Yury P.; Felsteiner, Joshua; Slutsker, Yakov Z. [Physics Department, Technion-Israel Institute of Technology, 32000 Haifa (Israel)

    2014-04-28

    The idea of replacing metal antenna elements with equivalent plasma objects has long been of interest because of the possibility of switching the antenna on and off. In general, two kinds of designs have so far been reported: (a) Separate plasma “wires” which are thin glass tubes filled with gas, where plasma appears due to discharge inside. (b) Reflecting surfaces, consisting of tightly held plasma wires or specially designed large discharge devices with magnetic confinement. The main disadvantages of these antennas are either large weight and size or too irregular surfaces for proper reflection. To design a microwave plasma antenna in the most common radar wavelength range of 1–3?cm with a typical gain of 30?dB, a smooth plasma mirror having a 10–30?cm diameter and a proper curvature is required. The plasma density must be 10{sup 12}–10{sup 14}?cm{sup ?3} in order to exceed the critical density for the frequency of the electromagnetic wave. To achieve this we have used a ferromagnetic inductively coupled plasma (FICP) source, where a thin magnetic core of a large diameter is fully immersed in the plasma. In the present paper, we show a way to adapt the FICP source for creating a flat switchable microwave plasma mirror with an effective diameter of 30?cm. This mirror was tested as a microwave reflector and there was found no significant difference when compared with a copper plate having the same diameter.

  6. Inkjet Printing of UWB Antennas on Paper Based , S. Safavi-Naeini1

    E-Print Network [OSTI]

    Tentzeris, Manos

    , flexible electronics (also known as flex circuits) is a technology that not just has witnessed an increase antennas/electronics for ad-hoc wireless sensor networks operating in rugged environments. I. INTRODUCTION monitoring systems Wearable electronics for wireless body area network (WBAN) High speed WLANs and wireless

  7. Fully printed phased-array antenna for space communications Maggie Yihong Chen*a

    E-Print Network [OSTI]

    Chen, Ray

    of integrated electronics circuits on the flexible surface [1, 2]. To date, the major way to achieve flexible) derivatives and pentacene. While the organic material based flexible electronic circuits can be monolithically integrated with flexible antennas, the carrier (electron or hole) mobility of these materials is less than 0

  8. Your Noise is My Command: Sensing Gestures Using the Body as an Antenna

    E-Print Network [OSTI]

    Anderson, Richard

    -1-4503-0267-8/11/05....$10.00. Figure 1: The human body behaves as an antenna in the pres- ence of noise radiat (USA) {gabecohn, shwetak}@uw.edu ABSTRACT Touch sensing and computer vision have made human- computer home wall using no specialized sensors. We con- duct a series of experiments to explore

  9. Low cost and compact active integrated antenna transceiver for system applications 

    E-Print Network [OSTI]

    Flynt, Robert Alvin

    1995-01-01

    is presented that has a Schottky mixer diode and an FET integrated within an inverted patch antenna. The FET serves as the source for the transmitter and as the local oscillator. A 5.5 dB isotropic conversion loss at 6 GHz with a 200 MHz intermediate frequency...

  10. Thermoplastic Green Machining for Textured Dielectric Substrate for Broadband Miniature Antenna

    E-Print Network [OSTI]

    Sendur, Gullu Kiziltas

    Thermoplastic Green Machining for Textured Dielectric Substrate for Broadband Miniature Antenna dielectric substrate for a broadband miniature an- tenna was fabricated using a thermoplastic green machining­Ba­Nd­Titania; BBNT) and an epoxy. At first, a thermoplastic compound, consisting of BBNT particles and thermoplastic

  11. Energy Efficient Radio Resource Management in a Coordinated Multi-Cell Distributed Antenna System

    E-Print Network [OSTI]

    Yanikomeroglu, Halim

    Energy Efficient Radio Resource Management in a Coordinated Multi-Cell Distributed Antenna System efficient radio resource management are some of the energy saving methods. It is observed and two energy efficient radio resource management schemes are investigated; either ports can be switched

  12. Constraints on cosmic neutrino fluxes from the Antarctic Impulsive Transient Antenna experiment

    E-Print Network [OSTI]

    Besson, David Zeke

    2006-05-01

    We report new limits on cosmic neutrino fluxes from the test flight of the Antarctic Impulsive Transient Antenna (ANITA) experiment, which completed an 18.4 day flight of a prototype long-duration balloon payload, called ANITA-lite, in early 2004...

  13. RF-MEMS Capacitive Series Switches of CPW & MSL Configurations for Reconfigurable Antenna Application

    E-Print Network [OSTI]

    De Flaviis, Franco

    RF-MEMS Capacitive Series Switches of CPW & MSL Configurations for Reconfigurable Antenna, University of California Irvine, Irvine, CA, 92697 Abstract: The air-bridged RF-MEMS switches in single pole) and coplanar waveguide (CPW) structures. RF-MEMS series switches are monolithic fabricated in both transmission

  14. GNSS Spoofing Detection Using High-Frequency Antenna Motion and Carrier-Phase Data

    E-Print Network [OSTI]

    Psiaki, Mark L.

    GNSS Spoofing Detection Using High-Frequency Antenna Motion and Carrier-Phase Data by Mark L. Psiaki, Steven P. Powell, and Brady W. O'Hanlon Cornell University, Ithaca, N.Y. 14853-7501, U.S.A. BIOGRAPHIES Mark L. Psiaki is a Professor of Mechanical and Aerospace Engineering. He received a B

  15. IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION 1 A Rigorous and Efficient Analysis of 3D Printed

    E-Print Network [OSTI]

    Aksun, M. Irsadi

    IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION 1 A Rigorous and Efficient Analysis of 3D Printed of structures with multiple vertical strips running in multilayer environment. Index Terms-- Multilayered 3D is developed to accurately simulate 3D structures in multilayer environment [1], and to simultaneously simulate

  16. Empowering the Industrial Internet of Things with 3D Printed Sensors and Antennas

    E-Print Network [OSTI]

    Das, Suman

    3/23/15 1 Empowering the Industrial Internet of Things with 3D Printed Sensors and Antennas Optomec Enabling Technology for the IIoT 9 Fully Print 3D Parts or Print-on 3Dtm Parts · Print Structural-process (dry, cure, sinter...) Part § Fine line traces § 3D Conformal printing § Interconnects § Embedded

  17. SAVE THIS | EMAIL THIS | Close Near-field microscopy: Optical antennae enable nanoscale microscopy and spectroscopy

    E-Print Network [OSTI]

    Novotny, Lukas

    of free-propagating radiation to localized energy, and vice versa. For example, the antenna of a cell phone is used to concentrate the energy of incoming radiation onto a receiver chip with dimensions much, because conventional optics redirects the wavefronts of propagating radiation, it is unable to sample

  18. Memory-Assisted Exciton Diffusion in the Chlorosome Light-Harvesting Antenna of Green Sulfur Bacteria

    E-Print Network [OSTI]

    Saikin, Semion

    Memory-Assisted Exciton Diffusion in the Chlorosome Light- Harvesting Antenna of Green Sulfur of bacteriochlorophylls (BChls) enclosed by a lipid monolayer.1-4 They can capture light and transfer it in a form. In green sulfur bacteria, light energy absorbed by the rolls is transferred via a baseplate9 to the Fenna

  19. THIN CERAMIC FERROELECTRIC PHASE SHIFTER FOR STEERABLE MICROSTRIP PATCH ANTENNA ARRAY

    E-Print Network [OSTI]

    De Flaviis, Franco

    #12;1 THIN CERAMIC FERROELECTRIC PHASE SHIFTER FOR STEERABLE MICROSTRIP PATCH ANTENNA ARRAY Franco the use of thin ceramic ferroelectric materials for the design of phase shifters used in the realization properties at room temperature. We also demonstrated how the use of thin ceramics reduces the required bias

  20. REGULAR PAPER Towards efficient hydrogen production: the impact of antenna size

    E-Print Network [OSTI]

    Roegner, Matthias

    REGULAR PAPER Towards efficient hydrogen production: the impact of antenna size and external-biological hydrogen production Á Phycobilisomes Á Synechocystis Abbreviations APC Allophycocyanin CCCP Carbonyl of a hydrogen-based economy is the fact that present hydrogen production is mainly based on fossil rather than

  1. Analysis of large reflector antennas using CSP fringe formulation and higher-order diffraction

    E-Print Network [OSTI]

    Nehorai, Arye

    Analysis of large reflector antennas using CSP fringe formulation and higher-order diffraction- tric conductor (PEC) objects when illuminated by a Complex Source Points (CSP) beam expansion (S of a CSP-expansion illumination. In this work we discuss an application of the CSP fringe formulation

  2. Reliable Communications in Aerial Sensor Networks by Using A Hybrid Antenna

    E-Print Network [OSTI]

    New South Wales, University of

    -sized Unmanned Aerial Vehicles (UAVs) equipped with sensors and wireless radio, enables low cost high granularity- able mobile sensors to explore the aerial dimension, i.e., engineering Unmanned Aerial Vehicles (UAVsReliable Communications in Aerial Sensor Networks by Using A Hybrid Antenna Kai Li Nadeem Ahmed

  3. Reliable Positioning with Hybrid Antenna Model for Aerial Wireless Sensor and Actor Networks

    E-Print Network [OSTI]

    Turgut, Damla

    of multiple unmanned aerial vehicles. An actor node in the network has the capabilities of both acting accordingly. The recent advances in Unmanned Aerial Vehicles (UAVs) made it possible to deploy Aerial WirelessReliable Positioning with Hybrid Antenna Model for Aerial Wireless Sensor and Actor Networks Kai Li

  4. Integrated Algorithms and Multiple Antenna Techniques for Direction of Arrival (DOA) Estimation 

    E-Print Network [OSTI]

    Xia, Zhenchun

    2013-04-25

    direction of Kent distribution to present the DOA vector, which further improves the accuracy of DOA finding. At last, we design and build a multi-channel and real time automated measurement system to validate the proposed antenna structure and integrated...

  5. Secondary emission from synthetic opal infiltrated by colloidal gold and glycine

    E-Print Network [OSTI]

    Dovbeshko, G; Boyko, V; Romanyuk, V; Gorelik, V; Moiseyenko, V; Sobolev, V; Shvalagin, V

    2012-01-01

    A comparison of the secondary emission (photoluminescence) and Bragg reflection spectra of photonic crystals (PC), namely, synthetic opals, opals infiltrated by colloidal gold, glycine, and a complex of colloidal gold with glycine is performed. The infiltration of colloidal gold and a complex of colloidal gold with glycine into the pores of PC causes a short-wavelength shift (about 5-15 nm) of the Bragg reflection and increases the intensity of this band by 1.5-3 times. In photoluminescence, the infiltration of PC by colloidal gold and colloidal gold with glycine suppresses the PC emission band near 375-450 nm and enhances the shoulder of the stop-zone band of PC in the region of 470-510 nm. The shape of the observed PC emission band connected with defects in synthetic opal is determined by the type of infiltrates and the excitation wavelength. Possible mechanisms of the effects are discussed.

  6. Electrocatalysts having gold monolayers on platinum nanoparticle cores, and uses thereof

    DOE Patents [OSTI]

    Adzic, Radoslav; Zhang, Junliang

    2010-04-27

    The invention relates to gold-coated particles useful as fuel cell electrocatalysts. The particles are composed of an electrocatalytically active core at least partially encapsulated by an outer shell of gold or gold alloy. The invention more particularly relates to such particles having a noble metal-containing core, and more particularly, a platinum or platinum alloy core. In other embodiments, the invention relates to fuel cells containing these electrocatalysts and methods for generating electrical energy therefrom.

  7. From Antenna to Assay: Lessons Learned in Lanthanide Luminescence

    SciTech Connect (OSTI)

    Moore, Evan; Samuel, Amanda; Raymond, Kenneth

    2008-09-25

    Ligand-sensitized luminescent lanthanide(III) complexes are of considerable current interest due to their unique photophysical properties (micro- to millisecond lifetimes, characteristic and narrow emission bands, and large Stokes shifts), which make them well suited to serve as labels in fluorescence-based bioassays. The long-lived Ln(III) emission can be temporally resolved from scattered light and background fluorescence, resulting in vastly enhanced measurement sensitivity. One of the challenges in this field is the design of sensitizing ligands that provide highly emissive Ln(III) complexes that also possess sufficient stability and aqueous solubility required for practical applications. In this account we give an overview of some of the general properties of the trivalent lanthanides and follow with a summary of advances made in our laboratory in the development of highly luminescent Tb(III) and Eu(III) complexes for applications in biotechnology. A focus of our research has been the optimization of these compounds as potential commercial agents for use in Homogeneous Time Resolved Fluorescence (HTRF) technology, the requirements and current use of which will be briefly discussed. Our approach involves developing high-stability octadentate Tb(III) and Eu(III) complexes that rely on all-oxygen donor atoms as well as using multi-chromophore chelates to increase molar absorptivity compared to earlier examples that utilize a single pendant antenna chromophore. We have found that ligands based on 2-hydroxyisophthalamide (IAM) provide exceptionally emissive Tb(III) complexes with quantum yield values up to ca. 60%. Solution thermodynamic studies have indicated that these complexes are stable at the nanomolar concentrations required for commercial assays. Through synthetic modification of the IAM-chromophore, in conjunction with time-dependent density functional theory (TD-DFT) calculations, we have developed a method to predict absorption and emission properties of these chromophores as a tool to guide ligand design. Additionally we have investigated chiral IAM ligands that yield Tb(III) complexes possessing both high quantum yield values and strong circularly polarized luminescence (CPL) activity. To efficiently sensitize Eu(III) emission, we have utilized ligands based on the 1-hydroxypyridin-2-one (1,2-HOPO) chelate, which are remarkable since they combine both excellent photophysical properties in addition to exceptional aqueous stabilities. A more compete understanding of this chromophore has been achieved by combining low temperature phosphorescence measurements with the same TD-DFT approach used with the IAM system. Also, Eu(III) complexes with strong CPL activity have been obtained through preparation of chiral 1,2-HOPO ligands. Using the unique spectroscopic properties of Eu(III), we have also undertaken the kinetic analysis of radiative and non-radiative decay pathways for a series of complexes, which has highlighted the importance of the metal ion symmetry on the ensuing photophysical properties. Lastly, the commercial development of a Tb-IAM compound that offers improved performance in the common HTRF platform and has the potential to vastly improve the sensitivity of measurements carried out using this technique is presented.

  8. Numerical simulation of the electromagnetic fields excited by loop antennas in plasma in the whistler frequency range

    SciTech Connect (OSTI)

    Koldanov, V. A.; Korobkov, S. V.; Gushchin, M. E.; Kostrov, A. V. [Russian Academy of Sciences, Institute of Applied Physics (Russian Federation)

    2011-08-15

    The electromagnetic fields excited by circular loop antennas in a magnetized plasma in the whistler frequency range are simulated by the finite-difference time-domain method. The spatial structure of quasi-monochromatic fields excited in the near- and far-field zones by an antenna with a harmonic current, as well as the dynamics of the electromagnetic field excited by an antenna with a current in the form of a single video pulse, is studied. Simulations performed for a uniform plasma and uniform ambient magnetic field agree well with the results of theoretical analysis and model laboratory experiments performed on large-scale plasma devices.

  9. New chemistry with gold-nitrogen complexes: synthesis and characterization of tetra-, tri-, and dinuclear gold(I) amidinate complexes. Oxidative-addition to the dinuclear gold(I) amidinate 

    E-Print Network [OSTI]

    Abdou, Hanan Elsayed

    2009-06-02

    Nitrogen ligands have been little studied with gold(I) and almost no chemistry has been described using anionic bridging nitrogen ligands. This dissertation concerns the impact of the bridging ligands amidinate, ArNHC(H)NAr, ...

  10. Energy loss of coasting gold ions and deuterons in RHIC.

    SciTech Connect (OSTI)

    Abreu,N.; Blaskiewicz, M.; Brown, K.A.; Butler, J.J.; FischW; Harvey, M.; Tepikian, S.

    2008-06-23

    The total energy loss of coasting gold ion beams was measured at RHIC at two energies, corresponding to a gamma of 75.2 and 107.4. We describe the experiment and observations and compare the measured total energy loss with expectations from ionization losses at the residual gas, the energy loss due to impedance and synchrotron radiation. We find that the measured energy losses are below what is expected from free space synchrotron radiation. We believe that this shows evidence for suppression of synchrotron radiation which is cut off at long wavelength by the presence of the conducting beam pipe.

  11. Guided Self-Assembly of Gold Thin Films

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverse (Journalvivo Low-Dose Lowï‚— WeUpdate JonGuided Self-Assembly of Gold Thin

  12. Guided Self-Assembly of Gold Thin Films

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverse (Journalvivo Low-Dose Lowï‚— WeUpdate JonGuided Self-Assembly of Gold

  13. Guided Self-Assembly of Gold Thin Films

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverse (Journalvivo Low-Dose Lowï‚— WeUpdate JonGuided Self-Assembly of GoldGuided

  14. Spectral-efficiency of multi-antenna links in ad-hoc wireless networks with limited Tx CSI

    E-Print Network [OSTI]

    Govindasamy, Siddhartan

    An asymptotic expression is derived for the mean spectral efficiency of multi-antenna links randomly distributed on a plane in a uniform manner where transmitters (Tx) have Channel-State-Information (CSI) of the channels ...

  15. Measuring Phased-Array Antenna Beampatterns with High Dynamic Range for the Murchison Widefield Array using 137 MHz ORBCOMM Satellites

    E-Print Network [OSTI]

    Neben, A R; Hewitt, J N; Bernardi, G; Bowman, J D; Briggs, F; Cappallo, R J; Deshpande, A A; Goeke, R; Greenhill, L J; Hazelton, B J; Johnston-Hollitt, M; Kaplan, D L; Lonsdale, C J; McWhirter, S R; Mitchell, D A; Morales, M F; Morgan, E; Oberoi, D; Ord, S M; Prabu, T; Shankar, N Udaya; Srivani, K S; Subrahmanyan, R; Tingay, S J; Wayth, R B; Webster, R L; Williams, A; Williams, C L

    2015-01-01

    Detection of the fluctuations in 21 cm line emission from neutral hydrogen during the Epoch of Reionization in thousand hour integrations poses stringent requirements on calibration and image quality, both of which necessitate accurate primary beam models. The Murchison Widefield Array (MWA) uses phased array antenna elements which maximize collecting area at the cost of complexity. To quantify their performance, we have developed a novel beam measurement system using the 137 MHz ORBCOMM satellite constellation and a reference dipole antenna. Using power ratio measurements, we measure the {\\it in situ} beampattern of the MWA antenna tile relative to that of the reference antenna, canceling the variation of satellite flux or polarization with time. We employ angular averaging to mitigate multipath effects (ground scattering), and assess environmental systematics with a null experiment in which the MWA tile is replaced with a second reference dipole. We achieve beam measurements over 30 dB dynamic range in beam...

  16. IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, VOL. 54, NO. 4, APRIL 2006 1243 High-Order Generalized Extended Born

    E-Print Network [OSTI]

    Torres-Verdín, Carlos

    IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, VOL. 54, NO. 4, APRIL 2006 1243 High-Verdín, Member, IEEE Abstract--Previous work on the subject of electromagnetic scat- tering has shown

  17. SiGe receiver front ends and flip-chip integrated wideband antennas for millimeter-wave passive imaging

    E-Print Network [OSTI]

    Powell, Johnna, 1980-

    2009-01-01

    SiGe wideband 77-GHz and 94-GHz front end receivers with integrated antennas for passive imaging have been designed and characterized. These front end systems exhibit wideband performance with the highest gain and lowest ...

  18. Design of a Class of Antennas Utilizing MEMS, EBG and Septum Polarizers including Near-field Coupling Analysis

    E-Print Network [OSTI]

    Kim, Ilkyu

    2012-01-01

    inverted-F antenna with an RF MEMS switch for the correctionP. G. Steeneken, “A Five-band MEMS Switched PIFA for MobileApplications to Reconfigurable MEMS Filters,” in IEEE MTT-S

  19. Low pumping energy mode of the "optical bars''/"optical lever" topologies of gravitational-wave antennae

    E-Print Network [OSTI]

    F. Ya. Khalili

    2003-04-16

    The ``optical bars''/``optical lever'' topologies of gravitational-wave antennae allow to obtain sensitivity better that the Standard Quantum Limit while keeping the optical pumping energy in the antenna relatively low. Element of the crucial importance in these schemes is the local meter which monitors the local test mirror position. Using cross-correlation of this meter back-action noise and its measurement noise it is possible to further decrease the optical pumping energy. In this case the pumping energy minimal value will be limited by the internal losses in the antenna only. Estimates show that for values of parameters available for contemporary and planned gravitational-wave antennae, sensitivity about one order of magnitude better than the Standard Quantum Limit can be obtained using the pumping energy about one order of magnitude smaller energy than is required in the traditional topology in order to obtain the the Standard Quantum Limit level of sensitivity.

  20. Whistler wave radiation from a pulsed loop antenna located in a cylindrical duct with enhanced plasma density

    SciTech Connect (OSTI)

    Kudrin, Alexander V.; Shkokova, Natalya M.; Ferencz, Orsolya E.; Zaboronkova, Tatyana M.

    2014-11-15

    Pulsed radiation from a loop antenna located in a cylindrical duct with enhanced plasma density is studied. The radiated energy and its distribution over the spatial and frequency spectra of the excited waves are derived and analyzed as functions of the antenna and duct parameters. Numerical results referring to the case where the frequency spectrum of the antenna current is concentrated in the whistler range are reported. It is shown that under ionospheric conditions, the presence of an artificial duct with enhanced density can lead to a significant increase in the energy radiated from a pulsed loop antenna compared with the case where the same source is immersed in the surrounding uniform magnetoplasma. The results obtained can be useful in planning active ionospheric experiments with pulsed electromagnetic sources operated in the presence of artificial field-aligned plasma density irregularities that are capable of guiding whistler waves.

  1. MASKLESS ELECTROCHEMICAL PATTERNING OF GOLD FILMS FOR BIOSENSORS USING MICROMACHINED POLYIMIDE PROBES

    E-Print Network [OSTI]

    Basu, Amar S.

    MASKLESS ELECTROCHEMICAL PATTERNING OF GOLD FILMS FOR BIOSENSORS USING MICROMACHINED POLYIMIDE chemicals for chemical and biosensors. After gold patterns are revealed, the surface can be treated] and proteins [8] can be selectively attached to the SAMs and used in biosensor applications as depicted in Fig

  2. Molecularly Resolved Images of Peptide-Functionalized Gold Surfaces by Scanning Tunneling Microscopy

    E-Print Network [OSTI]

    Webb, Lauren J.

    propargylglycine unnatural functional groups 20 Å apart and an alkanethiol self-assembled monolayer (SAM) on a gold-terminated surfaces in which a structured -helical peptide is chemically bonded to an alkanethiol self-assembledMolecularly Resolved Images of Peptide-Functionalized Gold Surfaces by Scanning Tunneling

  3. Sol immobilization technique: a delicate balance between activity, selectivity and stability for gold catalyst

    SciTech Connect (OSTI)

    Villa, Alberto [Universita di Milano, Italy] [Universita di Milano, Italy; Wang, Di [Fritz Haber Institute of the Max Planck Society, Berlin, Germany] [Fritz Haber Institute of the Max Planck Society, Berlin, Germany; Veith, Gabriel M [ORNL] [ORNL; Prati, Laura [Universita di Milano, Italy] [Universita di Milano, Italy

    2013-01-01

    Sol immobilization is a widely used method to prepare gold catalysts. The presence of the protective layer can have a significant influence on catalyst properties by mediating metal-support and reactantmetal interactions. This paper details the effect of a polyvinyl alcohol (PVA) protecting groups on the activity of a supported gold catalysts as well as its selectivity towards glycerol oxidation.

  4. Gold mining and the golden rule: a challenge for producers and consumers in developing countries

    E-Print Network [OSTI]

    Vermont, University of

    ; accepted 17 May 2004 Available online 23 May 2005 Abstract The environmental and social impact of gold environmental impacts, they must also evaluate their own consumption patterns of gold. This paper explores-year process of self-evaluation to assess progress towards sustainable development in a report entitled

  5. Synthesis, structure and spectroscopic investigations of luminescent heterobimetallic gold(I)-Rhodium(I) species

    E-Print Network [OSTI]

    Dempsey, Jillian Lee

    2005-01-01

    A novel, three-coordinate gold(I) dimer, Au2(tfepm)3Cl2 (la, lb), was synthesized and structurally characterized. Four gold(I)-rhodium(I) heterobimetallic complexes, AuIRh'(tBuNC)2(-dppm)2C12 (2), Au'Rh'(tBuNC)2(u-dmpm)2Cl2 ...

  6. Hydroxyalkyl phosphine gold complexes for use as diagnostic and therapeutic pharmaceuticals and method of making same

    DOE Patents [OSTI]

    Katti, K.V.; Berning, D.E.; Volkert, W.A.; Ketring, A.R.

    1998-12-01

    A complex and method for making a diagnostic or therapeutic pharmaceutical includes a ligand comprising at least one hydroxyalkyl phosphine donor group bound to a gold atom to form a gold-ligand complex that is stable in aqueous solutions containing oxygen, serum and other body fluids. 20 figs.

  7. PHYSICAL REVIEW B 86, 195418 (2012) Gold-embedded zigzag graphene nanoribbons as spin gapless semiconductors

    E-Print Network [OSTI]

    Krasheninnikov, Arkady V.

    2012-01-01

    PHYSICAL REVIEW B 86, 195418 (2012) Gold-embedded zigzag graphene nanoribbons as spin gapless semiconductors Xiaohui Hu,1 Wei Zhang,2 Litao Sun,1,* and Arkady V. Krasheninnikov3,4 1 SEU-FEI Nano-Pico Center properties of zigzag graphene nanoribbons (ZGNRs) with gold (Au) atoms embedded into different sites

  8. Magnetron sputtering of gold nanoparticles onto WO3 and activated carbon

    E-Print Network [OSTI]

    Pennycook, Steve

    Magnetron sputtering of gold nanoparticles onto WO3 and activated carbon Gabriel M. Veith a and investigation of two supported gold catalyst systems prepared by magnetron sputtering: Au on WO3 and Au, such as WO3 and carbon, which are generally not accessible using the ubiquitous deposition

  9. ANNEALING EFFECTS ON INTERFACIAL FRACTURE OF GOLD-CHROMIUM FILMS IN HYBRID MICROCIRCUITS

    E-Print Network [OSTI]

    Volinsky, Alex A.

    ANNEALING EFFECTS ON INTERFACIAL FRACTURE OF GOLD-CHROMIUM FILMS IN HYBRID MICROCIRCUITS N. R on the resistance to interfacial fracture of gold-chromium films in hybrid microcircuits. The samples were prepared, interfacial fracture energies were determined using mechanics-based models modified for multilayer film

  10. ARCHITECTURE OF A CHARGE-TRANSFER STATE REGULATING LIGHT HARVESTING IN A PLANT ANTENNA PROTEIN

    SciTech Connect (OSTI)

    Fleming, Graham; Ahn, Tae Kyu; Avenson, Thomas J.; Ballottari, Matteo; Cheng, Yuan-Chung; Niyogi, Krishna K.; Bassi, Roberto; Fleming, Graham R.

    2008-04-02

    Energy-dependent quenching of excess absorbed light energy (qE) is a vital mechanism for regulating photosynthetic light harvesting in higher plants. All of the physiological characteristics of qE have been positively correlated with charge-transfer between coupled chlorophyll and zeaxanthin molecules in the light-harvesting antenna of photosystem II (PSII). In this work, we present evidence for charge-transfer quenching in all three of the individual minor antenna complexes of PSII (CP29, CP26, and CP24), and we conclude that charge-transfer quenching in CP29 involves a de-localized state of an excitonically coupled chlorophyll dimer. We propose that reversible conformational changes in CP29 can `tune? the electronic coupling between the chlorophylls in this dimer, thereby modulating the energy of the chlorophylls-zeaxanthin charge-transfer state and switching on and off the charge-transfer quenching during qE.

  11. Cavity-excited Huygens' metasurface antennas: near-unity aperture efficiency from arbitrarily-large apertures

    E-Print Network [OSTI]

    Epstein, Ariel; Eleftheriades, George V

    2015-01-01

    One of the long-standing problems in antenna engineering is the realization of highly-directive beams using low-profile devices. In this paper we provide a solution to this problem by means of Huygens' metasurfaces (HMSs), based on the equivalence principle. This principle states that a given excitation can be transformed to a desirable aperture field by inducing suitable electric and magnetic surface currents. Building on this concept, we propose and demonstrate cavity-excited HMS antennas, where the single-source cavity excitation is designed to optimize aperture illumination, while the HMS facilitates the current distribution that ensures phase purity of aperture fields. The HMS breaks the coupling between the excitation and radiation spectrum typical to standard partially-reflecting surfaces, allowing tailoring of the aperture properties to produce a desirable radiation pattern. As shown, a single semianalytical formalism can be followed to achieve control of a variety of radiation features, such as the d...

  12. Dynamic Beam Shaping Using a Dual-Band Metasurface-Inspired Electronically Tunable Reflectarray Antenna

    E-Print Network [OSTI]

    Tayebi, Amin; Paladhi, Pavel Roy; Udpa, Lalita; Udpa, Satish; Rothwell, Edward

    2015-01-01

    An electronically reconfigurable dual-band-reflectarray antenna is presented in this paper. The tunable unit cell, a ring loaded square patch with a single varactor diode connected across the gap between the ring and the patch, is modeled using both a full-wave solver and an equivalent circuit. The parameters of the equivalent circuit are calculated independently of the simulation and experiment using analysis techniques employed in frequency selective surfaces. The reflection phase of the proposed unit cell is shown to provide an excellent phase range of 335$^{\\circ}$ in F band and 340$^{\\circ}$ in S band. Results from the analysis are used to design and build a 10x10 element reflectarray antenna. The high tuning phase range of each element allows the fabricated reflectarray to demonstrate a very broad steering range of up to $\\pm$60$^{\\circ}$ in both frequency bands.

  13. An experimental verification of metamaterial coupled enhanced transmission for antenna applications

    SciTech Connect (OSTI)

    Pushpakaran, Sarin V.; Raj, Rohith K.; Pradeep, Anju; Ouseph, Lindo; Hari, Mridula; Chandroth, Aanandan; Pezholil, Mohanan; Kesavath, Vasudevan

    2014-02-10

    Inspired by the work of Bethe on electromagnetic transmission through subwavelength hole, there has been immense interest on the extraordinary transmission through subwavelength slot/slit on metal plates. The invention of metamaterials has boosted the extra ordinary transmission through subwavelength slots. We examine computationally and experimentally the concept of metamaterial cover using an array of split ring resonators (SRRs), for enhancing the transmission in a stacked dipole antenna working in the S band. The front to back ratio is considerably improved by enhancing the magnetic resonant strength in close proximity of the slit of the upper parasitic dipole. The effect of stacking height of the SRR monolayer on the resonant characteristics of the split ring resonators and its effect on antenna radiation characteristics has been studied.

  14. Theoretical characterization of excitation energy transfer in chlorosome light-harvesting antennae from green sulfur bacteria

    E-Print Network [OSTI]

    Fujita, Takatoshi; Saikin, Semion K; Brookes, Jennifer C; Aspuru-Guzik, Alan

    2013-01-01

    Chlorosomes are the largest and most efficient natural light-harvesting antenna systems. They contain thousands of pigment molecules - bacteriochlorophylls (BChls)- that are organized into supramolecular aggregates and form a very efficient network for excitonic energy migration. Here, we present a theoretical study of excitation energy transfer (EET) in the chlorosome based on experimental evidence of the molecular assembly. Our model for the exciton dynamics throughout the antenna combines a stochastic time propagation of the excitonic wave function with molecular dynamics simulations of supramolecular structure, and electronic structure calculations of the excited states. The simulation results reveal a detailed picture of the EET in the chlorosome. Coherent energy transfer is significant only for the first 50 fs after the initial excitation, and the wavelike motion of the exciton is completely damped at 100 fs. Characteristic time constants of incoherent energy transfer, subsequently, vary from 1 ps to se...

  15. Mechanical 144?GHz beam steering with all-metallic epsilon-near-zero lens antenna

    SciTech Connect (OSTI)

    Pacheco-Peña, V. Torres, V. Orazbayev, B. Beruete, M. Sorolla, M.; Navarro-Cía, M.; Engheta, N.

    2014-12-15

    An all-metallic steerable beam antenna composed of an ?-near-zero (ENZ) metamaterial lens is experimentally demonstrated at 144?GHz (?{sub 0}?=?2.083?mm). The ENZ lens is realized by an array of narrow hollow rectangular waveguides working just near and above the cut-off of the TE{sub 10} mode. The lens focal arc on the xz-plane is initially estimated analytically as well as numerically and compared with experimental results demonstrating good agreement. Next, a flange-ended WR-6.5 waveguide is placed along the lens focal arc to evaluate the ENZ-lens antenna steerability. A gain scan loss below 3?dB is achieved for angles up to ±15°.

  16. A physical model of radiated enhancement of plasma-surrounded antenna

    SciTech Connect (OSTI)

    Gao, Xiaotian; Wang, Chunsheng, E-mail: wangcs@hit.edu.cn; Jiang, Binhao; Zhang, Zhonglin [Harbin Institute of Technology, 92 West Dazhi Street, Nan Gang District, 150001 Harbin (China)

    2014-09-15

    A phenomenon that the radiated power may be enhanced when an antenna is surrounded by a finite plasma shell has been found in numerical and experimental studies. In this paper, a physical model was built to express the mechanism of the radiated enhancement. In this model, the plasma shell is treated as a parallel connection of a capacitance and a conductance whose parameters change with the system parameters (plasma density, collision frequency, and antenna frequency). So, the radiated enhancement can be explained by the resonance between the plasma shell and the infinite free space. Furthermore, the effects of system parameters on the radiated power are given and effects corresponding to mechanisms are performed based on the physical model.

  17. Melting, freezing, and coalescence of gold nanoclusters Laurent J. Lewis, (a) Pablo Jensen, and JeanLouis Barrat

    E-Print Network [OSTI]

    Lewis, Laurent J.

    Melting, freezing, and coalescence of gold nanoclusters Laurent J. Lewis, (a) Pablo Jensen We present a detailed molecular­dynamics study of the melting, freezing, and coalescence of gold to address two issues. First, we investigate the influence of size on the melting and freezing of gold

  18. Novel technologies and techniques for low-cost phased arrays and scanning antennas 

    E-Print Network [OSTI]

    Rodenbeck, Christopher Timothy

    2004-11-15

    -reconfigurable holographic antenna: (a) conducting regions formed on a silicon wafer and (b) corresponding far-field radiation pattern. (Courtesy of Dr. A. Fathy, University of Tennessee.) .... 22 6 A commercially available optically controlled grating... E-plane radiation pattern as the beam scans at 30 GHz ???????... 45 17 E-plane radiation pattern as the beam scans at 35 GHz. The second space harmonic (dashed) is associated with the maximum reverse scan ???... 46 18 E-plane radiation...

  19. The Design of Small Sue Chip Ceramic Dielectric Antenna for Bluetooth Application

    E-Print Network [OSTI]

    Park, Seong-Ook

    The Design of Small Sue Chip Ceramic Dielectric Antenna for Bluetooth Application Abstract This pap uls radiation mtalr are formed on bothIhs fDsr of ceramic dicbrlnr (8 x I x 1.5 mm, alumma) nod (WO. SocCzy, vol. II,pp.55-62, 2000 [ 5 ] HFSS.AnroRCom. #12;Fig 3 The rrlum 101s of pmpored ceramic ammna

  20. Antenna design for fast ion collective Thomson scattering diagnostic for the international thermonuclear experimental reactor

    SciTech Connect (OSTI)

    Leipold, F.; Furtula, V.; Salewski, M.; Bindslev, H.; Korsholm, S. B.; Meo, F.; Michelsen, P. K.; Moseev, D.; Nielsen, S. K.; Stejner, M. [Association Euratom--Risoe National Laboratory for Sustainable Energy, Technical University of Denmark, DK-4000 Roskilde (Denmark)

    2009-09-15

    Fast ion physics will play an important role for the international thermonuclear experimental reactor (ITER), where confined alpha particles will affect and be affected by plasma dynamics and thereby have impacts on the overall confinement. A fast ion collective Thomson scattering (CTS) diagnostic using gyrotrons operated at 60 GHz will meet the requirements for spatially and temporally resolved measurements of the velocity distributions of confined fast alphas in ITER by evaluating the scattered radiation (CTS signal). While a receiver antenna on the low field side of the tokamak, resolving near perpendicular (to the magnetic field) velocity components, has been enabled, an additional antenna on the high field side (HFS) would enable measurements of near parallel (to the magnetic field) velocity components. A compact design solution for the proposed mirror system on the HFS is presented. The HFS CTS antenna is located behind the blankets and views the plasma through the gap between two blanket modules. The viewing gap has been modified to dimensions 30x500 mm{sup 2} to optimize the CTS signal. A 1:1 mock-up of the HFS mirror system was built. Measurements of the beam characteristics for millimeter-waves at 60 GHz used in the mock-up agree well with the modeling.

  1. Coupling and matching study of the ICRF antenna for W7-X

    SciTech Connect (OSTI)

    Messiaen, A.; Krivska, A.; Louche, F.; Ongena, J.; Dumortier, P.; Durodie, F.; Van Eester, D.; Vervier, M. [Laboratory for Plasma Physics, Royal Military Academy, EURATOM-Belgian State Association, TEC partner, B-1000 Brussels (Belgium)

    2014-02-12

    A tight antenna plug consisting in a pair of straps with strong pre-matching covers the first selected frequency band (25-38MHz) for W7-X and provides the toroidal phasings for heating, current drive and wall conditioning. Another plug-in with two short strap triplets is devoted for operation around 76MHz. The antenna coupling to a reference plasma profile is first analyzed by means of the coupling code ANTITER II. It shows the radiation power spectra for the different phasing cases and indicates the problem of the edge power deposition through the Alfven resonance occurring when the operating frequency is lower than the majority cyclotron frequency. Matrices provided by the TOPICA code are used for the matching-decoupling study of the first antenna plug. The large mutual coupling between the 2 straps is counterbalanced by the use of a decoupler. Finally the tunable 5-port junction used to feed in parallel each triplet of the second plug-in is analyzed by means of MWS simulation together with its decoupling-matching system.

  2. A novel variable-distance antenna test range and high spatial resolution corroboration of the inverse square law for 433.5 MHz radiation

    E-Print Network [OSTI]

    de Haën, Christoph; Erhardt, Matthias

    2015-01-01

    A novel, low-budget, open-air, slant-geometry antenna test range for UHF radiation is presented. It was designed primarily to facilitate variation of the distance between emitter and receiver antennas, but has also the potential for adaptation to simultaneous variation of distance and receiver antenna orientation. In support of the validity of the range the inverse square law for 433.5 MHz radiation between two naked half-wave dipole antennas was tested with high spatial resolution from close to the far field limit outward to 46 wavelengths. Sine amplitude input voltage at the receiver antenna varied with the distance to the power -0.9970 +/- 0.0051 (R^2 = 0.992), thus corroborating the inverse square law for transmission power at the lowest frequency for which thus far data have been published. Keywords: inverse square law; dipole antenna; test facility; electromagnetic propagation; UHF measurements; distance dependence.

  3. Contact voltage-induced softening of RF microelectromechanical system gold-on-gold contacts at cryogenic temperatures

    SciTech Connect (OSTI)

    Berman, D.; Krim, J. [Department of Physics, North Carolina State University, Raleigh, North Carolina 26795 (United States); Walker, M. J. [Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 26795 (United States)

    2010-08-15

    A series of experiments were performed in vacuum environments to investigate the impact of rf micromechanical system switch contact voltage versus resistance for gold-on-gold contacts at cryogenic temperatures. The purpose of this work was twofold as follows: (1) to examine whether asperity heating models already validated for high temperature contacts were also applicable at cryogenic temperatures and (2) to explore the implications and validity of prior suggestions that contact temperatures between 338 and 373 K are high enough to dissociate adsorbed film and/or push them aside but low enough to prevent asperities from becoming soft and adherent. Measurements on two distinct switch types, fabricated at independent laboratories, were performed in the temperature range 79-293 K and for contact voltages ranging from 0.01 to 0.13 V. Contact resistance values at all temperatures were observed to be lower for higher contact voltages, consistent with the aforementioned asperity heating models, whereby increased contact currents are associated with increased heating and softening effects. In situ removal of adsorbed species by oxygen plasma cleaning resulted in switch adhesive failure. Switches that had not been cleaned meanwhile exhibited distinct reductions in resistance at contact temperatures close to 338 K, consistent with suggestions that films begin to desorb, disassociate, and/or be pushed aside at that temperature.

  4. 2402 IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, VOL. 55, NO. 8, AUGUST 2007 INPUT IMPEDANCES OF AN 8-ELEMENT LOW SIDE-LOBE DIPOLE ARRAY

    E-Print Network [OSTI]

    So, Hing-Cheung

    -Enclosed Antennas. Norwood, MA: Artech House, 1997. [2] J. A. Shifflett, "CADDRAD: A physical optics radar., Dallas, TX, 1998, pp. 349­354. Passive Localization of

  5. Modeling pore corrosion in normally open gold- plated copper connectors.

    SciTech Connect (OSTI)

    Battaile, Corbett Chandler; Moffat, Harry K.; Sun, Amy Cha-Tien; Enos, David George; Serna, Lysle M.; Sorensen, Neil Robert

    2008-09-01

    The goal of this study is to model the electrical response of gold plated copper electrical contacts exposed to a mixed flowing gas stream consisting of air containing 10 ppb H{sub 2}S at 30 C and a relative humidity of 70%. This environment accelerates the attack normally observed in a light industrial environment (essentially a simplified version of the Battelle Class 2 environment). Corrosion rates were quantified by measuring the corrosion site density, size distribution, and the macroscopic electrical resistance of the aged surface as a function of exposure time. A pore corrosion numerical model was used to predict both the growth of copper sulfide corrosion product which blooms through defects in the gold layer and the resulting electrical contact resistance of the aged surface. Assumptions about the distribution of defects in the noble metal plating and the mechanism for how corrosion blooms affect electrical contact resistance were needed to complete the numerical model. Comparisons are made to the experimentally observed number density of corrosion sites, the size distribution of corrosion product blooms, and the cumulative probability distribution of the electrical contact resistance. Experimentally, the bloom site density increases as a function of time, whereas the bloom size distribution remains relatively independent of time. These two effects are included in the numerical model by adding a corrosion initiation probability proportional to the surface area along with a probability for bloom-growth extinction proportional to the corrosion product bloom volume. The cumulative probability distribution of electrical resistance becomes skewed as exposure time increases. While the electrical contact resistance increases as a function of time for a fraction of the bloom population, the median value remains relatively unchanged. In order to model this behavior, the resistance calculated for large blooms has been weighted more heavily.

  6. A segmented multi-loop antenna for selective excitation of azimuthal mode number in a helicon plasma source

    SciTech Connect (OSTI)

    Shinohara, S.; Tanikawa, T.; Motomura, T.

    2014-09-15

    A flat type, segmented multi-loop antenna was developed in the Tokai Helicon Device, built for producing high-density helicon plasma, with a diameter of 20 cm and an axial length of 100 cm. This antenna, composed of azimuthally splitting segments located on four different radial positions, i.e., r = 2.8, 4.8, 6.8, and 8.8 cm, can excite the azimuthal mode number m of 0, ±1, and ±2 by a proper choice of antenna feeder parts just on the rear side of the antenna. Power dependencies of the electron density n{sub e} were investigated with a radio frequency (rf) power less than 3 kW (excitation frequency ranged from 8 to 20 MHz) by the use of various types of antenna segments, and n{sub e} up to ?5 × 10{sup 12} cm{sup ?3} was obtained after the density jump from inductively coupled plasma to helicon discharges. Radial density profiles of m = 0 and ±1 modes with low and high rf powers were measured. For the cases of these modes after the density jump, the excited mode structures derived from the magnetic probe measurements were consistent with those expected from theory on helicon waves excited in the plasma.

  7. Remote optical sensing on the nanometer scale with a bowtie aperture nano-antenna on a SNOM fiber tip

    E-Print Network [OSTI]

    Atie, Elie M; Eter, Ali El; Salut, Roland; Nedeljkovic, Dusan; Tannous, Tony; Baida, Fadi I; Grosjean, Thierry

    2015-01-01

    Plasmonic nano-antennas have proven the outstanding ability of sensing chemical and physical processes down to the nano-meter scale. Sensing is usually achieved within the highly confined optical fields generated resonantly by the nano-antennas, i.e. in contact to the nano-structures. In these paper, We demonstrate the sensing capability of nano-antennas to their larger scale environment, well beyond their plasmonic confinement volume, leading to the concept of 'remote' (non contact) sensing on the nano-meter scale. On the basis of a bowtie-aperture nano-antenna (BNA) integrated at the apex of a SNOM fiber tip, we introduce an ultra-compact, move-able and background-free optical nano-sensor for the remote sensing of a silicon surface (up to distance of 300 nm). Sensitivity of the BNA to its large scale environment is high enough to expect the monitoring and control of the spacing between the nano-antenna and a silicon surface with sub-nano-meter accuracy. This work paves the way towards a new class of nano-po...

  8. Polyvalent Oligonucleotide Gold Nanoparticle Conjugates as Delivery Vehicles for Platinum(IV) Warheads

    E-Print Network [OSTI]

    Dhar, Shanta

    Amine-functionalized polyvalent oligonucleotide gold nanoparticles (DNA-Au NPs) were derivatized with a cisplatin prodrug, and the resulting DNA-Au NP conjugates were used to internalize multiple platinum centers. A ...

  9. Synthesis, characterization and assembly of the binary ligand protected gold nanoparticles

    E-Print Network [OSTI]

    Kim, Hyewon, Ph. D. Massachusetts Institute of Technology

    2013-01-01

    When a gold nanoparticle is coated with two dislike ligands, the ligands selfassemble on the nanoparticle surface and the phase separation occurs based on the miscibility and the size mismatch of two ligands, and the sizes ...

  10. Ultrasensitive Optical Shape Characterization of Gold Nanoantennas Using Second Harmonic Generation

    E-Print Network [OSTI]

    Dalang, Robert C.

    Ultrasensitive Optical Shape Characterization of Gold Nanoantennas Using Second Harmonic Generation for the sensitive optical characterization of plasmonic nanostructures. Furthermore, defects located where on the second harmonic signal. KEYWORDS: Plasmonics, nonlinear optics, surface integral formulation, realistic

  11. Effects of varying ethanol and water concentrations as a gold nanoparticle gel solvent

    E-Print Network [OSTI]

    Schaefer, Thomas Gerard

    2009-01-01

    Striped gold nanoparticles are unique in several of their characteristics and applications. Recent experiments have determined a new medium with which contain the nanoparticles is that of a chemical gel. The nanoparticles ...

  12. Syntheses and characterizations of homovalent and heterovalent dinuclear gold ylide metallocycles 

    E-Print Network [OSTI]

    Neitling, David Christopher

    1995-01-01

    Homovalent and heterovalent derivatives of the gold ylide metallocycle (Au[4(CH2)2PPh2l ) 2(l) have been synthesized. Substitution reactions with the potentially bidentate ligands methylenediphenylthiophosphinate (mtp) and diphenyldithio...

  13. An Archaeological Survey of Suemaur Exploration & Production, LLC's Lafitte's Gold Prospect in Galveston County, Texas 

    E-Print Network [OSTI]

    Moore, William

    2015-07-30

    An archaeological survey of Suemaur Exploration & Production, LLC’s Lafitte’s Gold Prospect was conducted on February 25, 2008 by BVRA in eastern Galveston County, Texas with negative results. The investigation examined a proposed drill site...

  14. Art versus politics: Mike Gold, Joseph Freeman, and literary radicalism in the 1920s 

    E-Print Network [OSTI]

    Starr, Clinton Robert

    1997-01-01

    In the 1920s, when there was little support for left wing writers from either the Communist Party or the broader intellectual community, literary intellectuals Mike Gold and Joseph Freeman attempted to use their writing to further the revolutionary...

  15. Gold Nanoparticles Functionalised with Fast Water Exchanging Gd3+ Chelates: Linker Effects on the Relaxivity

    E-Print Network [OSTI]

    Ferreira, Miguel F.; Gonçalves, Janaina; Mousavi, B.; Prata, M. I. M.; Rodrigues, S. P. J.; Calle, Daniel; López-Larrubia, Pilar; Cerdan, Sebastian; Rodrigues, Tiago B.; Ferreira, Paula M.; Helm, L.; Martins, José A.; Geraldes, Carlos F. G. C.

    2015-01-22

    The relaxivity displayed by Gd3+ chelates immobilized onto gold nanoparticles is the result of complex interplay between nanoparticle size, water exchange rate and chelate structure. In this work we study the effect of the length of ?...

  16. A revolutionary concept to improve the efficiency of ion cyclotron antennas

    SciTech Connect (OSTI)

    Milanesio, D., E-mail: daniele.milanesio@polito.it; Maggiora, R., E-mail: riccardo.maggiora@polito.it [Politecnico di Torino, Dipartimento di Elettronica e Telecomunicazioni (DET), Torino (Italy)

    2014-06-15

    The successful design of an ion cyclotron (IC) antenna mainly relies on the capability of coupling high power to the plasma (MW), feature that is currently reached by allowing rather high voltages (tens of kV) on the unavoidable unmatched part of the feeding lines. This requirement is often responsible of arcs along the transmission lines and other unwanted phenomena, such as rectification discharges or hotspots, that considerably limit the usage of IC launchers. In this work, we suggest and describe a revolutionary approach based on high impedance surfaces, which allows to increase the antenna radiation efficiency and, hence, to highly reduce the imposed voltages to couple the same level of power to the plasma. High-impedance surfaces are periodic metallic structures (patches) displaced usually on top of a dielectric substrate and grounded by means of vertical posts usually embedded inside a dielectric, in a mushroom-like shape. In terms of working properties, high impedance surfaces are electrically thin in-phase reflectors, i.e., they present a high impedance, within a given frequency band, such that the image currents are in-phase with the currents of the antenna itself, thus determining a significant efficiency increase. While the usual design of a high impedance surface requires the presence of a dielectric layer, some alternative solutions can be realised in vacuum, taking advantage of double layers of metallic patches. After an introductory part on the properties of high impedance surfaces, this work documents both their design by means of numerical codes and their implementation on a scaled mock-up.

  17. Theory and Manufacturing Processes of Solar NanoAntenna Electromagnetic Collectors

    SciTech Connect (OSTI)

    Dale K. Kotter; Steven D. Novack

    2010-02-01

    DRAFT For Submittal to Journal of Solar Energy - Rev 10.1 ---SOL-08-1091 SOLAR Nantenna Electromagnetic Collectors Dale K. Kotter Idaho National Laboratory Steven D. Novack Idaho National Laboratory W. Dennis Slafer MicroContinuum, Inc. Patrick Pinhero University of Missouri ABSTRACT The research described in this paper explores a new and efficient approach for producing electricity from the abundant energy of the sun, using nanoantenna (nantenna) electromagnetic collectors (NECs). NEC devices target mid-infrared wavelengths, where conventional photovoltaic (PV) solar cells are inefficient and where there is an abundance of solar energy. The initial concept of designing NECs was based on scaling of radio frequency antenna theory to the infrared and visible regions. This approach initially proved unsuccessful because the optical behavior of materials in the terahertz (THz) region was overlooked and, in addition, economical nanofabrication methods were not previously available to produce the optical antenna elements. This paper demonstrates progress in addressing significant technological barriers, including: 1) development of frequency-dependent modeling of double-feedpoint square spiral nantenna elements; 2) selection of materials with proper THz properties; and 3) development of novel manufacturing methods that could potentially enable economical large-scale manufacturing. We have shown that nantennas can collect infrared energy and induce THz currents, and we have also developed cost-effective proof-of-concept fabrication techniques for the large-scale manufacture of simple square loop nantenna arrays. Future work is planned to embed rectifiers into the double-feedpoint antenna structures. This work represents an important first step toward the ultimate realization of a low-cost device that will collect as well as convert this radiation into electricity. This could lead to a broadband, high conversion efficiency low-cost solution to complement conventional PV devices.

  18. Neutron and light scattering studies of light-harvesting photosynthetic antenna complexes

    SciTech Connect (OSTI)

    Tang, Kuo-Hsiang [Washington Univ., St. Louis, MO (United States); Blankenship, Robert E. [Washington Univ., St. Louis, MO (United States)

    2011-06-28

    Small-angle neutron scattering (SANS) and dynamic light scattering (DLS) have been employed in studying the structural information of various biological systems, particularly in systems without high-resolution structural information available. In this report, we briefly present some principles and biological applications of neutron scattering and DLS, compare the differences in information that can be obtained with small-angle X-ray scattering (SAXS), and then report recent studies of SANS and DLS, together with other biophysical approaches, for light-harvesting antenna complexes and reaction centers of purple and green phototrophic bacteria.

  19. Measured Sensitivity of the First Mark II Phased Array Feed on an ASKAP Antenna

    E-Print Network [OSTI]

    Chippendale, A P; Beresford, R J; Hampson, G A; Macleod, A; Shaw, R D; Brothers, M L; Cantrall, C; Forsyth, A R; Hay, S G; Leach, M

    2015-01-01

    This paper presents the measured sensitivity of CSIRO's first Mk. II phased array feed (PAF) on an ASKAP antenna. The Mk. II achieves a minimum system-temperature-over-efficiency $T_\\mathrm{sys}/\\eta$ of 78 K at 1.23 GHz and is 95 K or better from 835 MHz to 1.8 GHz. This PAF was designed for the Australian SKA Pathfinder telescope to demonstrate fast astronomical surveys with a wide field of view for the Square Kilometre Array (SKA).

  20. Mitigating illumination gradients in a SAR image based on the image data and antenna beam pattern

    DOE Patents [OSTI]

    Doerry, Armin W.

    2013-04-30

    Illumination gradients in a synthetic aperture radar (SAR) image of a target can be mitigated by determining a correction for pixel values associated with the SAR image. This correction is determined based on information indicative of a beam pattern used by a SAR antenna apparatus to illuminate the target, and also based on the pixel values associated with the SAR image. The correction is applied to the pixel values associated with the SAR image to produce corrected pixel values that define a corrected SAR image.

  1. An Optimization Model for Antenna Selection and Deployment in Single and Multi-cell RFID Systems

    E-Print Network [OSTI]

    Zou, Sicheng; Crisp, Michael; Sabesan, Sithamparanathan; Kadri, Abdullah; Penty, Richard V.; White, Ian H.

    2015-01-01

    Sabesan*, Abdullah Kadri+, Richard V. Penty* and Ian H. White* *Electrical Division, Department of Engineering University of Cambridge, Cambridge, UK Email: zs271@cam.ac.uk Figure 2 3D model of antenna radiation pattern with half power... .-March 2006 [2]. D.W. Engels, S. E. Sanjay, “The Reader collision problem ," IEEE International Conference on Systems, Man and Cybernetics, vol.3, pp.6-9 Oct. 2002 [3]. D.-Y. Kim, H.-G. Yoon, B.-J. Jang, and J.-G. Yook, “Effects of reader interference...

  2. Improved thermal stability of oxide-supported naked gold nanoparticles by ligand-assisted pinning

    SciTech Connect (OSTI)

    Moreno, C; Divins, N. J.; Gazquez, Jaume; Varela, Maria; Angurell, I; Llorca, J

    2012-01-01

    We report a method to improve the thermal stability, up to 900 C, of bare-metal (naked) gold nanoparticles supported on top of SiO{sub 2} and SrTiO{sub 3} substrates via ligand-assisted pinning. This approach leads to monodisperse naked gold nanoparticles without significant sintering after thermal annealing in air at 900 C. The ligand-assisted pinning mechanism is described.

  3. Noble Metal Catalysts for Mercury Oxidation in Utility Flue Gas: Gold, Palladium and Platinum Formulations

    SciTech Connect (OSTI)

    Presto, A.A.; Granite, E.J

    2008-07-01

    The use of noble metals as catalysts for mercury oxidation in flue gas remains an area of active study. To date, field studies have focused on gold and palladium catalysts installed at pilot scale. In this article, we introduce bench-scale experimental results for gold, palladium and platinum catalysts tested in realistic simulated flue gas. Our initial results reveal some intriguing characteristics of catalytic mercury oxidation and provide insight for future research into this potentially important process.

  4. Excitation and Far field Spectroscopy of surface plasmons in Gold nanostructures 

    E-Print Network [OSTI]

    Peng, Siying

    2011-08-08

    -1 EXCITATION AND FAR FIELD SPECTROSCOPY OF SURFACE PLASMONS IN GOLD NANOSTRUCTURES Major: Physics and Mathematics April 2010 Submitted to the Honors Programs Office Texas A&M University in partial fulfillment of the requirements for the designation... as HONORS UNDERGRADUATE RESEARCH FELLOW An Honors Fellows Thesis by SIYING PENG EXCITATION AND FAR FIELD SPECTROSCOPY OF SURFACE PLASMONS IN GOLD NANOSTRUCTURES Approved by: Research Advisor...

  5. Terahertz radiation-induced sub-cycle field electron emission across a split-gap dipole antenna

    E-Print Network [OSTI]

    Zhang, Jingdi; Fan, Kebin; Wang, Xiaoning; Zhang, Gu-Feng; Geng, Kun; Zhang, Xin; Averitt, Richard D

    2015-01-01

    We use intense terahertz pulses to excite the resonant mode (0.6 THz) of a micro-fabricated dipole antenna with a vacuum gap. The dipole antenna structure enhances the peak amplitude of the in-gap THz electric field by a factor of ~170. Above an in-gap E-field threshold amplitude of ~10 MVcm-1, THz-induced field electron emission is observed (TIFEE) as indicated by the field-induced electric current across the dipole antenna gap. Field emission occurs within a fraction of the driving THz period. Our analysis of the current (I) and incident electric field (E) is in agreement with a Millikan-Lauritsen analysis where log (I) exhibits a linear dependence on 1/E. Numerical estimates indicate that the electrons are accelerated to a value of approximately one tenth of the speed of light.

  6. Dual-band internal antenna ofPIFA type for mobile handsets and the effect of the handset case and battery

    E-Print Network [OSTI]

    Park, Seong-Ook

    Dual-band internal antenna ofPIFA type for mobile handsets and the effect of the handset case and battery Young-Jun Cho*, Soon-Ho Hwang, Osami Ishida, and Seong-Ook Park Information and Communications the influence of the handset case and battery. The proposed antenna operates at KPCS (1750-1870 MHz

  7. 47th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference 1-4 May 2006 Newport, Rhode Island Tape Spring Large Deployable Antenna

    E-Print Network [OSTI]

    Pellegrino, Sergio

    -mass 50 m2 deployable P-Band dual polarisation antenna that can measure terrestrial biomass levels from Newport, Rhode Island Tape Spring Large Deployable Antenna ¨O. Soykasap Afyon Kocatepe University of the equation; we also need to have an accurate measure of the global biomass level, a major element of which

  8. 4416 IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, VOL. 62, NO. 8, AUGUST 2014 A Decoupling Technique for Four-Element Symmetric

    E-Print Network [OSTI]

    Wu, Ke-Li

    ], the defected ground structures [4], [5], the inserted transmission lines [6], and the coupled resonator of the system, date rate and re- liability, where M is the number of antennas on base stations. However, as the number of antenna elements increases in a com- pact wireless device, the electric distance between

  9. IEEE Vehicular Technology Conference, pp. 2048-2052, October 2001, Atlantic City, New Jersey Performance of Smart Antennas with Adaptive Combining at Handsets

    E-Print Network [OSTI]

    Ha, Dong S.

    IEEE Vehicular Technology Conference, pp. 2048-2052, October 2001, Atlantic City, New Jersey 2048 Performance of Smart Antennas with Adaptive Combining at Handsets for the 3GPP WCDMA System Suk Won Kim1 the performance gain of dual smart antennas with an adaptive combining at handsets for the 3GPP WCDMA system

  10. Radiation induced effects on mechanical properties of nanoporous gold foams

    SciTech Connect (OSTI)

    Caro, M., E-mail: magda@lanl.gov, E-mail: efu@pku.edu.cn; Fu, E. G., E-mail: magda@lanl.gov, E-mail: efu@pku.edu.cn; Wang, Y. Q.; Martinez, E.; Caro, A. [Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Mook, W. M.; Sheehan, C.; Baldwin, J. K. [Center for Integrated Nanotechnology, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2014-06-09

    It has recently been shown that due to a high surface-to-volume ratio, nanoporous materials display radiation tolerance. The abundance of surfaces, which are perfect sinks for defects, and the relation between ligament size, defect diffusion, and time combine to define a window of radiation resistance [Fu et al., Appl. Phys. Lett. 101, 191607 (2012)]. Outside this window, the dominant defect created by irradiation in Au nanofoams are stacking fault tetrahedra (SFT). Molecular dynamics computer simulations of nanopillars, taken as the elemental constituent of foams, predict that SFTs act as dislocation sources inducing softening, in contrast to the usual behavior in bulk materials, where defects are obstacles to dislocation motion, producing hardening. In this work we test that prediction and answer the question whether irradiation actually hardens or softens a nanofam. Ne ion irradiations of gold nanofoams were performed at room temperature for a total dose up to 4 dpa, and their mechanical behavior was measured by nanoindentation. We find that hardness increases after irradiation, a result that we analyze in terms of the role of SFTs on the deformation mode of foams.

  11. World's Largest Gold Crystal Studied at Los Alamos

    ScienceCinema (OSTI)

    Vogel, Sven; Nakotte, Heinz

    2015-01-07

    When geologist John Rakovan needed better tools to investigate whether a dazzling 217.78-gram piece of gold was in fact the world's largest single-crystal specimen - a distinguishing factor that would not only drastically increase its market value but also provide a unique research opportunity - he traveled to Los Alamos National Laboratory's Lujan Neutron Scattering Center to peer deep inside the mineral using neutron diffractometry. Neutrons, different from other probes such as X-rays and electrons, are able to penetrate many centimeters deep into most materials. Revealing the inner structure of a crystal without destroying the sample - imperative, as this one is worth an estimated $1.5 million - would allow Rakovan and Lujan Center collaborators Sven Vogel and Heinz Nakotte to prove that this exquisite nugget, which seemed almost too perfect and too big to be real, was a single crystal and hence a creation of nature. Its owner, who lives in the United States, provided the samples to Rakovan to assess the crystallinity of four specimens, all of which had been found decades ago in Venezuela.

  12. Structure of incommensurate gold sulfide monolayer on Au(111)

    SciTech Connect (OSTI)

    Quek, S Y; Biener, M M; Biener, J; Bhattacharjee, J; Friend, C M; Waghmare, U V; Kaxiras, E

    2006-10-04

    Two-dimensional confined systems, such as substrate-supported incommensurate layers, are of interest because their structural and electronic properties may differ from those of bulk materials. While advances in experimental techniques have resulted in the growth of many such interesting systems, progress can often be hampered by the lack of an atomistic-scale understanding of the structure, especially for incommensurate systems. In this work, we develop an atomic-scale model for an ordered incommensurate gold-sulfide (AuS) adlayer that has been previously demonstrated to exist on the Au(111) surface, following sulfur deposition and annealing to 450 K. We introduce theoretical techniques within density functional theory to take into account charge transfer in an incommensurate system and model scanning tunneling microscopy images, which are in good agreement with experiment. Our simulations indicate that this model is remarkably robust. We analyze the nature of bonding in this structure using state-of-the-art Wannier-function based techniques. Our analysis provides a natural explanation for the extraordinary robustness and unusual stoichiometry of this layer. This structure and its chemistry have implications for related S-Au interfaces, such as those in self-assembled monolayers of thiols on Au substrates.

  13. Measurements of Antenna Surface for Millimeter-Wave Space Radio Telescope

    E-Print Network [OSTI]

    Kamegai, Kazuhisa; Doi, Akihiro; Sato, Eiichi

    2011-01-01

    In the construction of a space radio telescope, it is essential to use materials with a low noise factor and high mechanical robustness for the antenna surface. We present the results of measurements of the reflection performance of two candidates for antenna surface materials for use in a radio telescope installed in a new millimeter-wave astronomical satellite, ASTRO-G. To estimate the amount of degradation caused by fluctuations in the thermal environment in the projected orbit of the satellite, a thermal cycle test was carried out for two candidates, namely, copper foil carbon fiber reinforced plastic (CFRP) and aluminum-coated CFRP. At certain points during the thermal cycle test, the reflection loss of the surfaces was measured precisely by using a radiometer in the 41-45 GHz band. In both candidates, cracks appeared on the surface after the thermal cycle test, where the number density of the cracks increased as the thermal cycle progressed. The reflection loss also increased in proportion to the number...

  14. The Physical Conditions in a Pre Super Star Cluster Molecular Cloud in the Antennae Galaxies

    E-Print Network [OSTI]

    Johnson, K E; Indebetouw, R; Brogan, C L; Whitmore, B C; Hibbard, J; Sheth, K; Evans, A

    2015-01-01

    We present an analysis of the physical conditions in an extreme molecular cloud in the Antennae merging galaxies. This cloud has properties consistant with those required to form a globular cluster. We have obtained ALMA CO and 870$\\mu$m observations of the Antennae galaxy system with $\\sim 0".5$ resolution. This cloud stands out in the data with a radius of $\\lesssim 24$~pc and mass of $>5\\times 10^6$~M$_\\odot$. The cloud appears capable of forming a globular cluster, but the lack of associated thermal radio emission indicates that star formation has not yet altered the environment. The lack of thermal radio emission places the cloud in an early stage of evolution, which we expect to be short-lived ($\\lesssim 1$~Myr) and thus rare. Given its mass and kinetic energy, for the cloud to be confined (as its appearance strongly suggests) it must be subject to an external pressure of P/$k_B \\gtrsim 10^8$~K~cm$^{-3}$ -- 10,000 times higher than typical interstellar pressure. This would support theories that high pre...

  15. Study of the effects of corrugated wall structures due to blanket modules around ICRH antennas

    SciTech Connect (OSTI)

    Dumortier, Pierre; Louche, Fabrice; Messiaen, André; Vervier, Michel [LPP-ERM/KMS, EURATOM-Belgian State Association, TEC partner, B-1000 Brussels (Belgium)

    2014-02-12

    In future fusion reactors, and in ITER, the first wall will be covered by blanket modules. These blanket modules, whose dimensions are of the order of the ICRF wavelengths, together with the clearance gaps between them will constitute a corrugated structure which will interact with the electromagnetic waves launched by ICRF antennas. The conditions in which the grooves constituted by the clearance gaps between the blanket modules can become resonant are studied. Simple analytical models and numerical simulations show that mushroom type structures (with larger gaps at the back than at the front) can bring down the resonance frequencies, which could lead to large voltages in the gaps between the blanket modules and perturb the RF properties of the antenna if they are in the ICRF operating range. The effect on the wave propagation along the wall structure, which is acting as a spatially periodic (toroidally and poloidally) corrugated structure, and hence constitutes a slow wave structure modifying the wall boundary condition, is examined.

  16. Theoretical characterization of excitation energy transfer in chlorosome light-harvesting antennae from green sulfur bacteria

    E-Print Network [OSTI]

    Takatoshi Fujita; Joonsuk Huh; Semion K. Saikin; Jennifer C. Brookes; Alan Aspuru-Guzik

    2013-07-01

    Chlorosomes are the largest and most efficient natural light-harvesting antenna systems. They contain thousands of pigment molecules - bacteriochlorophylls (BChls)- that are organized into supramolecular aggregates and form a very efficient network for excitonic energy migration. Here, we present a theoretical study of excitation energy transfer (EET) in the chlorosome based on experimental evidence of the molecular assembly. Our model for the exciton dynamics throughout the antenna combines a stochastic time propagation of the excitonic wave function with molecular dynamics simulations of supramolecular structure, and electronic structure calculations of the excited states. The simulation results reveal a detailed picture of the EET in the chlorosome. Coherent energy transfer is significant only for the first 50 fs after the initial excitation, and the wavelike motion of the exciton is completely damped at 100 fs. Characteristic time constants of incoherent energy transfer, subsequently, vary from 1 ps to several tens of ps. We assign the time scales of the EET to specific physical processes by comparing our results with the data obtained from time-resolved spectroscopy experiments.

  17. Geometric effect on surface enhanced Raman scattering of nanoporous gold: Improving Raman scattering by tailoring ligament and nanopore ratios

    SciTech Connect (OSTI)

    Lang, X. Y.; Chen, L. Y.; Guan, P. F.; Fujita, T.; Chen, M. W. [WPI Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan)

    2009-05-25

    We have synthesized nanoporous gold (NPG) films with a nanostructure consisting of small nanopores and large gold ligaments by the combination of chemical dealloying and electroless plating. The NPG films exhibit dramatic improvement in surface enhanced Raman scattering (SERS) in comparison with the conventional NPG. The superior SERS effect of the NPG films results from the confluence effect of enhanced local surface plasmon fields and electromagnetic coupling between ligaments, as well as the weak plasmon damping with increasing gold ligament sizes.

  18. Effect of particle size on the thermo-optic properties of gold nanofluids – A thermal lens study

    SciTech Connect (OSTI)

    Kumar, B. Rajesh; Basheer, N. Shemeena; Kurian, Achamma [Photonics Lab, Department of Physics, Catholicate College, Pathanamthitta (India); George, Sajan D., E-mail: sajan.george@manipal.edu [Centre for Atomic and Molecular Physics, Manipal University, Manipal, Karnataka (India)

    2014-01-28

    Spherical gold nanoparticles having particle size in the range 30 to 50 nm are prepared using citrate reduction of gold chloride trihydrate in water. The influence of particle size on the thermal diffusivity value of gold nanofluid is measured using dual beam thermal lens technique. The present study shows that the particle size influences the effective thermal diffusivity value of the nanofluid substantially and the value decreases with decrease in particle size for the investigated samples.

  19. Audio Speech Segmentation Without Language-Specific Knowledge Kevin Gold (kevin.gold@yale.edu) and Brian Scassellati (scaz@cs.yale.edu)

    E-Print Network [OSTI]

    Scassellati, Brian

    that it warrants a kind of "mental shorthand." The new entry is only added if the cost of storage is less than.gold@yale.edu) and Brian Scassellati (scaz@cs.yale.edu) Department of Computer Science, 51 Prospect Street New Haven, CT together until the cepstral coefficient variance is low within each new seg- ment. These segments

  20. Synthesis and Characterization of Gold Clusters Ligated with 1,3-Bis(dicyclohexylphosphino)propane

    SciTech Connect (OSTI)

    Johnson, Grant E.; Priest, Thomas A.; Laskin, Julia

    2013-09-01

    In this multidisciplinary study we combine chemical reduction synthesis of novel gold clusters in solution with high-resolution analytical mass spectrometry (MS) to gain insight into the composition of the gold clusters and how their size, ionic charge state and ligand substitution influences their gas-phase fragmentation pathways. Ultra small cationic gold clusters ligated with 1,3-bis(dicyclohexylphosphino)propane (DCPP) were synthesized for the first time and introduced into the gas phase using electrospray ionization (ESI). Mass-selected cluster ions were fragmented employing collision induced dissociation (CID) and the product ions were analysed using MS. The solutions were found to contain the multiply charged cationic gold clusters Au9L43+, Au13L53+, Au6L32+, Au8L32+ and Au10L42+ (L = DCPP). The gas-phase fragmentation pathways of these cluster ions were examined systematically employing CID combined with MS. In addition, CID experiments were performed on related gold clusters of the same size and ionic charge state but capped with 1,3-bis(diphenylphosphino)propane (DPPP) ligands containing phenyl functional groups at the two phosphine centers instead of cyclohexane rings. It is shown that this relatively small change in the molecular substitution of the two phosphine centers in diphosphine ligands (C6H11 versus C6H5) exerts a pronounced influence on the size of the species that are preferentially formed in solution during reduction synthesis as well as the gas-phase fragmentation channels of otherwise identical gold cluster ions. The mass spectrometry results indicate that in addition to the length of the alkyl chain between the two phosphine centers, the substituents at the phosphine centers also play a crucial role in determining the composition, size and stability of diphosphine ligated gold clusters synthesized in solution.

  1. The Genomes On Line Database (GOLD) in 2009: status of genomic and metagenomic projects and their associated metadata

    SciTech Connect (OSTI)

    Liolios, Konstantinos; Chen, Amy; Mavromatis, Konstantinos; Tavernarakis, Nektarios; Hugenholtz, Phil; Markowitz, Victor; Kyrpides, Nikos C.

    2009-09-01

    The Genomes On Line Database (GOLD) is a comprehensive resource for centralized monitoring of genome and metagenome projects worldwide. Both complete and ongoing projects, along with their associated metadata, can be accessed in GOLD through precomputed tables and a search page. As of September 2009, GOLD contains information for more than 5800 sequencing projects, of which 1100 have been completed and their sequence data deposited in a public repository. GOLD continues to expand, moving toward the goal of providing the most comprehensive repository of metadata information related to the projects and their organisms/environments in accordance with the Minimum Information about a (Meta)Genome Sequence (MIGS/MIMS) specification.

  2. Design of an Overmoded-Waveguide Directional Antenna for Use in In-Building Ventilation Duct Wireless Networks

    E-Print Network [OSTI]

    Stancil, Daniel D.

    Design of an Overmoded-Waveguide Directional Antenna for Use in In-Building Ventilation Duct ventilation ducts. We obtain experimentally the element size and spacing of a reflector and driven element that can be used for IEEE 802.11b/g/n signals in a cylindrical duct to provide 3.1 dB of gain and a front

  3. 1382 IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, VOL. 49, NO. 10, OCTOBER 2001 Acoustic and Electromagnetic Wave Interaction

    E-Print Network [OSTI]

    Sarabandi, Kamal

    vibrating dielectric circular cylinder is presented. The incident acoustic wave causes a boundary by an incident acoustic wave. As proposed in an ear- lier work by the authors [2], the acoustically induced1382 IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, VOL. 49, NO. 10, OCTOBER 2001 Acoustic

  4. 658 IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY, VOL. 47, NO. 3, AUGUST 2005 A Triple-Band Internal Antenna: Design and

    E-Print Network [OSTI]

    Park, Seong-Ook

    applications. Anten- nas must be small enough to be built in the practical mobile handsets and have good-Band Internal Antenna: Design and Performance in Presence of the Handset Case, Battery, and Human Head Dong is extended and modified to tune the desired frequency bandwidth on the placement of handset case and battery

  5. Singlet and Triplet State Transitions of Carotenoids in the Antenna Complexes of Higher-Plant Photosystem I

    E-Print Network [OSTI]

    Romeo, Alessandro

    Singlet and Triplet State Transitions of Carotenoids in the Antenna Complexes of Higher-Plant -carotene was found to be associated only with the native LHCI preparation and recombinant Lhca3. In the native complexes, the main lutein absorption bands are located at 492 and 510 nm. It is shown

  6. Performance Measurement of 802.11a Wireless Links from UAV to Ground Nodes with Various Antenna Orientations

    E-Print Network [OSTI]

    Kung, H. T.

    Performance Measurement of 802.11a Wireless Links from UAV to Ground Nodes with Various Antenna measured performance of 802.11a wireless links from an unmanned aerial vehicle (UAV) to ground stations-station elevations. By comparing the performance of 32 simultaneous pairs of UAV and ground station configurations

  7. Antenna Installation Request for Vendors (Please download, complete, print, and sign the request; and send it to Communications Services.)

    E-Print Network [OSTI]

    Bigelow, Stephen

    06/01/01 Antenna Installation Request for Vendors (Please download, complete, print, and sign ____ Is a mast proposed for use with the whip? Yes ____ No____ If yes, state height, and mast construction material (wood, metal, fiberglass, etc.) ! Long wire ____ Length ____Height Of Mast ____ State mast

  8. Plasmonic Antenna Integrated Quantum Cascade Laser for Mode Confinement used for High Sensitivity Bio-Sensing Applications

    E-Print Network [OSTI]

    Mohseni, Hooman

    structure on the facet of the Quantum Cascade Laser. We have previously developed such composite material . The design has been optimized using full 3D- Finite-difference-time-domain (FDTD) simulations. The antenna integrated Quantum Cascade Laser where the optical mode has been squeezed within ~ 100nm and its interaction

  9. EE 153 Microwave Circuits and Antennas 12 units (3-2-7); 3rd term. Prerequisite: EE 45.

    E-Print Network [OSTI]

    Haile, Sossina M.

    EE 153 ­ Microwave Circuits and Antennas 12 units (3-2-7); 3rd term. Prerequisite: EE 45 microwave circuits using sophisticated network analyzers worth well over $100,000. The lab circuits will use the commercial microwave computer-aided engineering software package Microwave Office, which

  10. The Flow of Excitation Energy in LHCII Monomers: Implications for the Structural Model of the Major Plant Antenna

    E-Print Network [OSTI]

    van Stokkum, Ivo

    the ability to convert solar energy into chemical energy (stored in the form of ATP and NADPH), whichThe Flow of Excitation Energy in LHCII Monomers: Implications for the Structural Model of the Major Plant Antenna Claudiu C. Gradinaru,* Sevgi O¨ zdemir,# Demet Gu¨ len,# Ivo H.M. van Stokkum,* Rienk van

  11. 1610 IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS, VOL. 11, 2012 MRI-Derived 3-D-Printed Breast Phantom

    E-Print Network [OSTI]

    Hagness, Susan C.

    1610 IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS, VOL. 11, 2012 MRI-Derived 3-D-Printed Breast--We propose a 3-D-printed breast phantom for use in preclinical experimental microwave imaging studies the proce- dure for generating the 3-D-printed breast phantom and present the measured dielectric properties

  12. Tilt Beam Characteristic by Changing Length of Finite-Sized Square Dielectric Substrate of One Arm Rectangular Spiral Antenna

    E-Print Network [OSTI]

    De Flaviis, Franco

    Tilt Beam Characteristic by Changing Length of Finite-Sized Square Dielectric Substrate of One Arm by changing the length of finite-sized square dielectric substrate of one arm rectangular spiral antenna has). Horizontal spiral arm length (HL) is varied from HL=0.8o to HL=5.2o to choose the length that yields

  13. A Single-Arm Circular Spiral Antenna with Inner/Outer Feed Circuitry for Changing Polarization and Beam Characteristics

    E-Print Network [OSTI]

    De Flaviis, Franco

    A Single-Arm Circular Spiral Antenna with Inner/Outer Feed Circuitry for Changing Polarization and Computer Engineering University of California, Irvine Irvine, CA, 92697, USA Abstract: A single-arm and LHCP in outer feed at 10GHz, where L is a horizontal arm length. The frequency bandwidth for a 3-d

  14. Microwave and millimeter-wave rectifying circuit arrays and ultra-wideband antennas for wireless power transmission and communications 

    E-Print Network [OSTI]

    Ren, Yu-Jiun

    2009-05-15

    In the future, space solar power transmission and wireless power transmission will play an important role in gathering clean and infinite energy from space. The rectenna, i.e., a rectifying circuit combined with an antenna, is one of the most...

  15. IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, VOL. 51, NO. 10, OCTOBER 2003 2801 A Plane Wave Expansion of Spherical Wave

    E-Print Network [OSTI]

    Wu, Ke-Li

    IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, VOL. 51, NO. 10, OCTOBER 2003 2801 A Plane Wave Expansion of Spherical Wave Functions for Modal Analysis of Guided Wave Structures and Scatterers Robert H. MacPhie, Life Fellow, IEEE, and Ke-Li Wu, Senior Member, IEEE Abstract--A new finite plane wave series

  16. Compact circularly polarized slot-ring antenna and microstrip bandpass filter using triangular open-loop resonators 

    E-Print Network [OSTI]

    Farooqui, Muhammad Fahad

    2007-04-25

    In this thesis two different research topics are undertaken, both in the area of compact RF/microwave circuits design. The first topic involves the design of a compact circularly polarized (CP) slot-ring antenna. A study of several compact CP...

  17. 1270 IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, VOL. 51, NO. 6, JUNE 2003 Design of an Efficient Miniaturized UHF

    E-Print Network [OSTI]

    Sarabandi, Kamal

    for future automobiles, such as FM and CD radios, analog and digital cell phones, GPS, keyless entry, etc communications where low visibility and high mobility are required. Slot radiating elements, having a planar for a resonant narrow slot antenna. A very efficient radiating element that occupies an area as small as 0 12 0 0

  18. IEEE Antennas and Propagation Magazine, Vol. 54, No. 6, December 2012 69 A Study of RF Dosimetry from Exposure

    E-Print Network [OSTI]

    Schneider, John B.

    -frequency (RF) exposure caused by cell phones, where the position of the phone relative to the body is somewhat multiple antennas and radiate at different frequencies, ranging from 850 MHz to 2.4 GHz. Unlike radio radiating element and when one ignored the actual duty cycle of these meters did the SAR values exceed

  19. 1356 IEEE TRANSACTIONS ON COMMUNICATIONS, VOL. 50, NO. 8, AUGUST 2002 Antenna Gain Against Interference in CDMA

    E-Print Network [OSTI]

    Yanikomeroglu, Halim

    communications. I. INTRODUCTION THE CDMA1 reverse-link capacity of a network of antenna elements (AEs) is investigated in [1]. It is reported there that the capacity increases linearly with the number of AEs and it is further stated that this linear gain is valid irrespective of the user2 and AE positions (as long

  20. Gold deposits in the late Archaean Nzega-Igunga greenstone belt, central plateau of tanzania

    SciTech Connect (OSTI)

    Feiss, P.G.; Siyomana, S.

    1985-01-01

    2.2 m oz of gold have been produced, since 1935, from late Archaean (2480-2740 Ma) greenstone belts of the Central Plateau, Tanzania. North and east of Nzega (4/sup 0/12'S, 3/sup 0/11'E), 18% of the exposed basement, mainly Dodoman schists and granites, consists of metavolcanics and metasediments of the Nyanzian and Kavirondian Series. Four styles of mineralization are observed. 1. Stratabound quartz-gold veins with minor sulfides. Host rocks are quartz porphyry, banded iron formation (BIF), magnetite quartzite, and dense, cherty jasperite at the Sekenke and Canuck mines. The Canuck veins are on strike from BIF's in quartz-eye porphyry of the Igusule Hills. 2. Stratabound, disseminated gold in coarse-grained, crowded feldspar porphyry with lithic fragments and minor pyrite. At Bulangamilwa, the porphyry is conformable with Nyanzian-aged submarine (.) greenstone, volcanic sediment, felsic volcanics, and sericite phyllite. The deposits are on strike with BIF of the Wella Hills, which contains massive sulfide with up to 15% Pb+Zn. 3. Disseminated gold in quartz-albite metasomes in Nyanzian greenstones. At Kirondatal, alteration is associated with alaskites and feldspar porphyry dikes traceable several hundred meters into post-Dodoman diorite porphyry. Gold is with pyrite, arsenopyrite, pyrrhotite, minor chalcopyrite, and sphalerite as well as tourmalinite and silica-cemented breccias. 4. Basal Kavirondian placers in metaconglomerates containing cobbles and boulders of Dodoman and Nyanzian rocks several hundred meters up-section from the stratabound, disseminated mineralization at Bulangamilwa.

  1. An arc control and protection system for the JET lower hybrid antenna based on an imaging system

    SciTech Connect (OSTI)

    Figueiredo, J.

    2014-11-15

    Arcs are the potentially most dangerous events related to Lower Hybrid (LH) antenna operation. If left uncontrolled they can produce damage and cause plasma disruption by impurity influx. To address this issue an arc real time control and protection imaging system for the Joint European Torus (JET) LH antenna has been implemented. The LH system is one of the additional heating systems at JET. It comprises 24 microwave generators (klystrons, operating at 3.7 GHz) providing up to 5 MW of heating and current drive to the JET plasma. This is done through an antenna composed of an array of waveguides facing the plasma. The protection system presented here is based primarily on an imaging arc detection and real time control system. It has adapted the ITER like wall hotspot protection system using an identical CCD camera and real time image processing unit. A filter has been installed to avoid saturation and spurious system triggers caused by ionization light. The antenna is divided in 24 Regions Of Interest (ROIs) each one corresponding to one klystron. If an arc precursor is detected in a ROI, power is reduced locally with subsequent potential damage and plasma disruption avoided. The power is subsequently reinstated if, during a defined interval of time, arcing is confirmed not to be present by image analysis. This system was successfully commissioned during the restart phase and beginning of the 2013 scientific campaign. Since its installation and commissioning, arcs and related phenomena have been prevented. In this contribution we briefly describe the camera, image processing, and real time control systems. Most importantly, we demonstrate that an LH antenna arc protection system based on CCD camera imaging systems works. Examples of both controlled and uncontrolled LH arc events and their consequences are shown.

  2. Detecting nonlinear acoustic waves in liquids with nonlinear dipole optical antennae

    E-Print Network [OSTI]

    Maksymov, Ivan S

    2015-01-01

    Ultrasound is an important imaging modality for biological systems. High-frequency ultrasound can also (e.g., via acoustical nonlinearities) be used to provide deeply penetrating and high-resolution imaging of vascular structure via catheterisation. The latter is an important diagnostic in vascular health. Typically, ultrasound requires sources and transducers that are greater than, or of order the same size as the wavelength of the acoustic wave. Here we design and theoretically demonstrate that single silver nanorods, acting as optical nonlinear dipole antennae, can be used to detect ultrasound via Brillouin light scattering from linear and nonlinear acoustic waves propagating in bulk water. The nanorods are tuned to operate on high-order plasmon modes in contrast to the usual approach of using fundamental plasmon resonances. The high-order operation also gives rise to enhanced optical third-harmonic generation, which provides an important method for exciting the higher-order Fabry-Perot modes of the dipole...

  3. Transmissive infrared frequency selective surfaces and infrared antennas : final report for LDRD 105749.

    SciTech Connect (OSTI)

    Wendt, Joel Robert; Hadley, G. Ronald; Samora, Sally; Loui, Hung; Cruz-Cabrera, Alvaro Augusto; Davids, Paul; Kemme, Shanalyn A.; Basilio, Lorena I.; Johnson, William Arthur; Peters, David William

    2009-09-01

    Plasmonic structures open up new opportunities in photonic devices, sometimes offering an alternate method to perform a function and sometimes offering capabilities not possible with standard optics. In this LDRD we successfully demonstrated metal coatings on optical surfaces that do not adversely affect the transmission of those surfaces at the design frequency. This technology could be applied as an RF noise blocking layer across an optical aperture or as a method to apply an electric field to an active electro-optic device without affecting optical performance. We also demonstrated thin optical absorbers using similar patterned surfaces. These infrared optical antennas show promise as a method to improve performance in mercury cadmium telluride detectors. Furthermore, these structures could be coupled with other components to lead to direct rectification of infrared radiation. This possibility leads to a new method for infrared detection and energy harvesting of infrared radiation.

  4. Memory-assisted exciton diffusion in the chlorosome light-harvesting antenna of green sulfur bacteria

    E-Print Network [OSTI]

    Takatoshi Fujita; Jennifer C. Brookes; Semion K. Saikin; Alan Aspuru-Guzik

    2012-06-25

    Chlorosomes are likely the largest and most efficient natural light-harvesting photosynthetic antenna systems. They are composed of large numbers of bacteriochlorophylls organized into supramolecular aggregates. We explore the microscopic origin of the fast excitation energy transfer in the chlorosome using the recently-resolved structure and atomistic-detail simulations. Despite the dynamical disorder effects on the electronic transitions of the bacteriochlorophylls, our simulations show that the exciton delocalizes over the entire aggregate in about 200 fs. The memory effects associated to the dynamical disorder assist the exciton diffusion through the aggregates and enhance the diffusion coefficients as a factor of two as compared to the model without memory. Furthermore, exciton diffusion in the chlorosome is found to be highly anisotropic with the preferential transfer towards the baseplate, which is the next functional element in the photosynthetic system.

  5. Thermal imaging of plasma with a phased array antenna in QUEST

    SciTech Connect (OSTI)

    Mishra, Kishore, E-mail: mishra@triam.kyushu-u.ac.jp; Nagata, K.; Akimoto, R.; Banerjee, S. [IGSES, Kyushu University, Kasuga, Fukuoka 816-8580 (Japan); Idei, H.; Zushi, H.; Hanada, K.; Hasegawa, M.; Nakamura, K.; Fujisawa, A.; Nagashima, Y.; Onchi, T.; Kuzmin, A. [RIAM, Kyushu University, Kasuga, Fukuoka 816-8580 (Japan); Yamamoto, M. K. [Research Institute for Sustainable Humanosphere, Kyoto University, Uji 611-0011 (Japan)

    2014-11-15

    A thermal imaging system to measure plasma Electron Bernstein Emission (EBE) emanating from the mode conversion region in overdense plasma is discussed. Unlike conventional ECE/EBE imaging, this diagnostics does not employ any active mechanical scanning mirrors or focusing optics to scan for the emission cones in plasma. Instead, a standard 3 × 3 waveguide array antenna is used as a passive receiver to collect emission from plasma and imaging reconstruction is done by accurate measurements of phase and intensity of these signals by heterodyne detection technique. A broadband noise source simulating the EBE, is installed near the expected mode conversion region and its position is successfully reconstructed using phase array technique which is done in post processing.

  6. Probing the Electrical Switching of a Memristive Optical Antenna by STEM EELS

    E-Print Network [OSTI]

    Schoen, David T; Brongersma, Mark L

    2015-01-01

    The scaling of active photonic devices to deep-submicron length-scales has been hampered by the fundamental diffraction limit and the absence of materials with sufficiently strong electro-optic effects. Here, we demonstrate a solid state electro-optical switching mechanism that can operate in the visible spectral range with an unparalleled active volume of less than 5 nm cube, comparable to the size of the smallest electronic components. The switching mechanism relies on electrochemically displacing metal atoms inside the nanometer-scale gap to electrically connect two crossed metallic wires forming a crosspoint junction. Such junctions afford extreme light concentration and display singular optical behavior upon formation of a conductive channel. We illustrate how this effect can be used to actively tune the resonances of plasmonic antennas. The tuning mechanism is analyzed using a combination of electrical and optical measurements as well as electron energy loss (EELS) in a scanning transmission electron mi...

  7. Microwave Ablation of Pulmonary Malignancies Using a Novel High-energy Antenna System

    SciTech Connect (OSTI)

    Little, Mark W.; Chung, Daniel; Boardman, Philip; Gleeson, Fergus V.; Anderson, Ewan M.

    2013-04-15

    To evaluate the technical success, safety, and imaging follow-up of malignant pulmonary nodules treated with a novel high-energy percutaneous microwave ablation (MWA) system. Between July 2010 and September 2011, a total of 23 patients, 12 men, mean age 68 (range 30-87) years with 29 pulmonary malignancies of median diameter 19 (range 8-57) mm, underwent computed tomography (CT)-guided MWA with a 16G microwave needle antenna enabling power up to 180 W. Technical success was defined as needle placement in the intended lesion without death or serious injury. Adequacy of ablation was assessed at 24 h on contrast-enhanced CT. Circumferential solid or ground glass opacification >5 mm was used to define an ideal ablation. Local tumor recurrence was assessed at 1, 3, and 6 months after ablation on contrast-enhanced CT. MWA was technically successful in 93 % (n = 27). Mean ablation duration was 3.6 (range 1-9) min. Ten patients (43 %) developed a pneumothorax as a result of the MWA; only 3 (13 %) required placement of a chest drain. Thirty-day mortality rate was 0 %. The mean hospital stay was 1.5 (range 1-7) days. A total of 22 lesions (75 %) were surrounded by {>=}5 mm ground glass or solid opacification after the procedure. At a median follow-up of 6 months, local recurrence was identified in 3 out of 26 lesions, giving a local control rate of 88 %. MWA using a high-power antenna of pulmonary malignancies is safe, technically achievable, and enables fast ablation times.

  8. Charge Retention by Gold Clusters on Surfaces Prepared Using Soft Landing of Mass Selected Ions

    SciTech Connect (OSTI)

    Johnson, Grant E.; Priest, Thomas A.; Laskin, Julia

    2012-01-24

    Monodisperse gold clusters have been prepared on surfaces in different charge states through soft landing of mass-selected ions. Ligand-stabilized gold clusters were prepared in methanol solution by reduction of chloro(triphenylphosphine)gold(I) with borane tert-butylamine complex in the presence of 1,3-bis(diphenylphosphino)propane. Electrospray ionization was used to introduce the clusters into the gas-phase and mass-selection was employed to isolate a single ionic cluster species (Au11L53+, L = 1,3-bis(diphenylphosphino)propane) which was delivered to surfaces at well controlled kinetic energies. Using in-situ time of flight secondary ion mass spectrometry (TOF-SIMS) it is demonstrated that the Au11L53+ cluster retains its 3+ charge state when soft landed onto the surface of a 1H,1H,2H,2H-

  9. Gold nanoparticles for cancer detection and treatment: The role of adhesion

    SciTech Connect (OSTI)

    Oni, Y. [Princeton Institute for Science and Technology of Materials (PRISM), Princeton University, 70 Prospect Street, Princeton, New Jersey 08544 (United States); Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544 (United States); Hao, K. [Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Dozie-Nwachukwu, S.; Odusanya, O. S. [African University of Science and Technology (AUST), Kilometer 10, Airport Road, Abuja, Federal Capital Territory (Nigeria); Sheda Science and Technology Complex (SHESTCO), Gwagwalada, Abuja, Federal Capital Territory (Nigeria); Obayemi, J.D. [African University of Science and Technology (AUST), Kilometer 10, Airport Road, Abuja, Federal Capital Territory (Nigeria); Anuku, N. [Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544 (United States); Department of Chemistry and Chemical Technology, Bronx Community College, New York, New York 10453 (United States); Soboyejo, W. O. [Princeton Institute for Science and Technology of Materials (PRISM), Princeton University, 70 Prospect Street, Princeton, New Jersey 08544 (United States); Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544 (United States); African University of Science and Technology (AUST), Kilometer 10, Airport Road, Abuja, Federal Capital Territory (Nigeria)

    2014-02-28

    This paper presents the results of an experimental study of the effects of adhesion between gold nanoparticles and surfaces that are relevant to the potential applications in cancer detection and treatment. Adhesion is measured using a dip coating/atomic force microscopy (DC/AFM) technique. The adhesion forces are obtained for dip-coated gold nanoparticles that interact with peptide or antibody-based molecular recognition units (MRUs) that attach specifically to breast cancer cells. They include MRUs that attach specifically to receptors on breast cancer cells. Adhesion forces between anti-cancer drugs such as paclitaxel, and the constituents of MRU-conjugated Au nanoparticle clusters, are measured using force microscopy techniques. The implications of the results are then discussed for the design of robust gold nanoparticle clusters and for potential applications in localized drug delivery and hyperthermia.

  10. Effects of Metal Coating on Self-Assembled Monolayers on Gold. 1. Copper on Dodecanethiol and Octadecanethiol

    E-Print Network [OSTI]

    Myrick, Michael Lenn

    Effects of Metal Coating on Self-Assembled Monolayers on Gold. 1. Copper on Dodecanethiol on copper-coated SAMsconductedinourlaboratories.2 Inourpreviouswork, we fabricated gold-conjugated oligomer to characterize the SAM after the copper coating process. Prior studies on SAM/metal interfaces have been reported

  11. Calculation of the extinction cross section and lifetime of a gold nanoparticle using FDTD simulations

    SciTech Connect (OSTI)

    Radhakrishnan, Archana, E-mail: anju.archana@gmail.com [B.Tech, Engineering Physics, National Institute Of Technology, Calicut (India); Murugesan, Dr V., E-mail: murugesh@serc.iisc.in [Assistant Professor, Supercomputer Education and Research Centre, Indian Institute of Science, Bangalore (India)

    2014-10-15

    The electromagnetic theory of light explains the behavior of light in most of the domains quite accurately. The problem arises when the exact solution of the Maxwell's equation is not present, in case of objects with arbitrary geometry. To find the extinction cross-section and lifetime of the gold nanoparticle, the software FDTD solutions 8.6 by Lumerical is employed. The extinction cross-sections and lifetimes of Gold nanospheres of different sizes and arrangements are studied using pulse lengths of the order of femtoseconds. The decay constant and other properties are compared. Further, the lifetimes are calculated using frequency and time domain calculations.

  12. Gold-titania interface toughening and thermal conductance enhancement using an organophosphonate nanolayer

    SciTech Connect (OSTI)

    Chow, Philippe K.; O'Brien, Peter; Ramanath, Ganpati; Cardona Quintero, Y.; Ramprasad, R.; Hubert Mutin, P.; Lane, Michael

    2013-05-20

    We demonstrate that a mercaptan-terminated organophosphonate nanolayer at gold-titania interfaces can give rise to two- to three-fold enhancement in the interfacial fracture toughness and thermal conductance. Electron spectroscopy reveals that interfacial delamination occurs at the metal-molecule interface near the gold-sulfur bonds, consistent with density functional theory calculations of bond energies. Qualitative correlation between interfacial fracture toughness and bond energies suggest that organophosphonate nanolayers are resilient to humidity-induced degradation. These results, and the versatility of organophosphonates as surface functionalization agents for technologically relevant materials, unlock uncharted avenues for molecular engineering of interfaces in materials and devices for a variety of applications.

  13. Three-dimensional x-ray fluorescence mapping of a gold nanoparticle-loaded phantom

    SciTech Connect (OSTI)

    Ren, Liqiang; Wu, Di; Li, Yuhua; Liu, Hong, E-mail: liu@ou.edu [Center for Bioengineering and School of Electrical and Computer Engineering, University of Oklahoma, Norman, Oklahoma 73019 (United States)] [Center for Bioengineering and School of Electrical and Computer Engineering, University of Oklahoma, Norman, Oklahoma 73019 (United States); Wang, Ge [Biomedical Imaging Cluster and Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)] [Biomedical Imaging Cluster and Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); Wu, Xizeng [Department of Radiology, University of Alabama, Birmingham, Alabama 35233 (United States)] [Department of Radiology, University of Alabama, Birmingham, Alabama 35233 (United States)

    2014-03-15

    Purpose : X-ray fluorescence (XRF) is a promising technique with sufficient specificity and sensitivity for identifying and quantifying features in small samples containing high atomic number (Z) materials such as iodine, gadolinium, and gold. In this study, the feasibility of applying XRF to early breast cancer diagnosis and treatment is studied using a novel approach for three-dimensional (3D) x-ray fluorescence mapping (XFM) of gold nanoparticle (GNP)-loaded objects in a physical phantom at the technical level. Methods : All the theoretical analysis and experiments are conducted under the condition of using x-ray pencil beam and a compactly integrated x-ray spectrometer. The penetrability of the fluorescence x-rays from GNPs is first investigated by adopting a combination of BR12 with 70 mm/50 mm in thickness on the excitation/emission path to mimic the possible position of tumor goldin vivo. Then, a physical phantom made of BR12 is designed to translate in 3D space with three precise linear stages and subsequently the step by step XFM scanning is performed. The experimental technique named as background subtraction is applied to isolate the gold fluorescence from each spectrum obtained by the spectrometer. Afterwards, the attenuations of both the incident primary x-ray beam with energies beyond the gold K-edge energy (80.725 keV) and the isolated gold K{sub ?} fluorescence x-rays (65.99 –69.80 keV) acquired after background subtraction are well calibrated, and finally the unattenuated K{sub ?} fluorescence counts are used to realize mapping reconstruction and to describe the linear relationship between gold fluorescence counts and corresponding concentration of gold solutions. Results : The penetration results show that the goldK{sub ?} fluorescence x-rays have sufficient penetrability for this phantom study, and the reconstructed mapping results indicate that both the spatial distribution and relative concentration of GNPs within the designed BR12 phantom can be well identified and quantified. Conclusions : Although the XFM method in this investigation is still studied at the technical level and is not yet practical for routinein vivo mapping tasks with GNPs, the current penetrability measurements and phantom study strongly suggest the feasibility to establish and develop a 3D XFM system.

  14. A review of "Full of Soup and Gold: The Life of Henry Jermyn" by Anthony Adolph 

    E-Print Network [OSTI]

    Maureen E. Mulvihill

    2007-01-01

    of the sites of production and the modes of transmission as part of understanding the poetics of the text and the dynamics of the period. Anthony Adolph. Full of Soup and Gold: The Life of Henry Jermyn. London: Anthony Adolph, 2006. Cloth. 324 pp., 31... Albans full of soup and gold, The new court?s pattern, stallion of the old. Him neither wit nor courage did exalt, But Fortune chose him for her pleasure salt. Paint him with drayman?s shoulders, butcher?s mien, Member?d like mules, with elephantine...

  15. Securing Wireless Data Networks against Eavesdropping Using Smart Antennas Sriram Lakshmanan, Cheng-Lin Tsao, Raghupathy Sivakumar, Tae-young chang

    E-Print Network [OSTI]

    Sivakumar, Raghupathy

    Securing Wireless Data Networks against Eavesdropping Using Smart Antennas Sriram Lakshmanan, Cheng-Lin Tsao, Raghupathy Sivakumar, Tae-young chang Georgia Institute of Technology Atlanta,GA,USA {sriram

  16. An ultra-wideband transmit/receive module using 10 to 35 GHz six-channel microstrip multiplexers and its applications to phased-array antenna transceiver systems 

    E-Print Network [OSTI]

    Hong, Seung Pyo

    2006-10-30

    using a simple model. Special emphasis is placed on the applications of several new filter designs for microstrip diplexers and multiplexers. Compact, full-duplex beam scanning antenna transceiver systems with extremely broad bandwidth have also been...

  17. New advances in symbol timing synchronization of single-carrier, multi-carrier and space-time multiple-antenna systems 

    E-Print Network [OSTI]

    Wu, Yik Chung

    2005-11-01

    In this dissertation, the problem of symbol timing synchronization for the following three different communication systems is studied: 1) conventional single-carrier transmissions with single antenna in both transmitter ...

  18. Modeling and Analysis of SiNW BioFET as Molecular Antenna for Bio-Cyber Interfaces towards the Internet of Bio-NanoThings

    E-Print Network [OSTI]

    Kuscu, Murat

    2015-01-01

    Seamless connection of molecular nanonetworks to macroscale cyber networks is envisioned to enable the Internet of Bio-NanoThings, which promises for cutting-edge applications, especially in the medical domain. The connection requires the development of an interface between the biochemical domain of molecular nanonetworks and the electrical domain of conventional electromagnetic networks. To this aim, in this paper, we propose to exploit field effect transistor based biosensors (bioFETs) to devise a molecular antenna capable of transducing molecular messages into electrical signals. In particular, focusing on the use of SiNW FET-based biosensors as molecular antennas, we develop deterministic and noise models for the antenna operation to provide a theoretical framework for the optimization of the device from communication perspective. We numerically evaluate the performance of the antenna in terms of the Signal-to-Noise Ratio (SNR) at the electrical output.

  19. Design, Modeling and Numerical Analysis of Microwave and Optical Devices: The Multi-band Patch Antenna, Ultra Wideband Ring Filter and Plasmonic Waveguide Coupler 

    E-Print Network [OSTI]

    Liu, Ya-Chi

    2014-01-14

    In this dissertation, three devices are studied and devised for the applications in microwave and optical communication: (1) Multiband Patch Antenna, (2) Ultra-Wideband Band Pass Ring Filter and (3) Plasmonic Waveguide Coupler with High Coupling...

  20. Modeling and experimental characterization of stepped and v-shaped (311) defects in silicon

    SciTech Connect (OSTI)

    Marqués, Luis A. Aboy, María; Dudeck, Karleen J.; Botton, Gianluigi A.; Knights, Andrew P.; Gwilliam, Russell M.

    2014-04-14

    We propose an atomistic model to describe extended (311) defects in silicon. It is based on the combination of interstitial and bond defect chains. The model is able to accurately reproduce not only planar (311) defects but also defect structures that show steps, bends, or both. We use molecular dynamics techniques to show that these interstitial and bond defect chains spontaneously transform into extended (311) defects. Simulations are validated by comparing with precise experimental measurements on actual (311) defects. The excellent agreement between the simulated and experimentally derived structures, regarding individual atomic positions and shape of the distinct structural (311) defect units, provides strong evidence for the robustness of the proposed model.

  1. Multichannel microwave interferometer with an antenna switching system for electron density measurement in a laboratory plasma experiment

    SciTech Connect (OSTI)

    Kawamori, Eiichirou; Lin, Yu-Hsiang [Institute of Space and Plasma Sciences, National Cheng Kung University, Tainan 70101, Taiwan (China)] [Institute of Space and Plasma Sciences, National Cheng Kung University, Tainan 70101, Taiwan (China); Mase, Atsushi [Art, Science and Technology Center for Cooperative Research, Kyushu University, Kasuga 816-8580 (Japan)] [Art, Science and Technology Center for Cooperative Research, Kyushu University, Kasuga 816-8580 (Japan); Nishida, Yasushi; Cheng, C. Z. [Institute of Space and Plasma Sciences, National Cheng Kung University, Tainan 70101, Taiwan (China) [Institute of Space and Plasma Sciences, National Cheng Kung University, Tainan 70101, Taiwan (China); Plasma and Space Science Center, National Cheng Kung University, Tainan 70101, Taiwan (China)

    2014-02-15

    This study presents a simple and powerful technique for multichannel measurements of the density profile in laboratory plasmas by microwave interferometry. This technique uses electromechanical microwave switches to temporally switch the connection between multiple receiver antennas and one phase-detection circuit. Using this method, the phase information detected at different positions is rearranged into a time series that can be acquired from a minimum number of data acquisition channels (e.g., two channels in the case of quadrature detection). Our successfully developed multichannel microwave interferometer that uses the antenna switching method was applied to measure the radial electron density profiles in a magnetized plasma experiment. The advantage of the proposed method is its compactness and scalability to multidimensional measurement systems at low cost.

  2. Direct, spectroscopic measurement of electric fields in a plasma-RF antenna interaction region in Tore Supra

    SciTech Connect (OSTI)

    Klepper, C Christopher; Hillis, Donald Lee; Isler, Ralph C; Hillairet, J.; Martin, E. H.; Colas, L.; Ekedahl, A.; Goniche, M.; Lotte, Ph.; Colledani, G.; Martin, V.; Panayotis, Stephanie; Pegourie, B.; Harris, Jeffrey H

    2013-01-01

    Balmer-series spectral line profiles of deuterium emission near a lower-hybrid (3.7 GHz) wave, high power (1-4 MW) launcher were measured with high-spectral resolution in the Tore Supra tokamak and fitted to an atomic physics model which includes both Zeeman and dynamic Stark effects. The magnetic field is static and the electric field is assumed to be monochromatic at 3.7 GHz. The determined strength and direction of the high-frequency electric field is found to be in good agreement with the results of a simulation that computes the propagation of these lower hybrid waves into the plasma in the region around the launch antenna and specifically in the region of estimated peak emission contributing to the measurement. This agreement indicates feasibility for the use of dynamic Stark effect spectroscopy to study interaction at the plasma antenna interactions in a fusion plasma environment. (C) 2013 Elsevier B. V. All rights reserved.

  3. Athena SWAN Silver and Gold renewal form www.athenaswan.org.uk Page 1 of 10

    E-Print Network [OSTI]

    Edinburgh, University of

    with Environmental and Sustainable Chemistry, Chemistry with Materials Chemistry, Medicinal and Biological Chemistry/Gold departmental renewal form Name of institution: University of Edinburgh Year: 2009 Department: Chemistry Contact website address: http://www.chem.ed.ac.uk/ 1. The School of Chemistry The School of Chemistry

  4. A Penicillamine Biosensor Based on Tyrosinase Immobilized on Nano-Au/ PAMAM Dendrimer Modified Gold Electrode

    E-Print Network [OSTI]

    Kwak, Juhyoun

    Modified Gold Electrode Nian Bing Li,a, b Juhyoun Kwaka * a Department of Chemistry, Korea Advanced to the solution, it reacted with o-benzoquinone to form the corresponding thioquinone derivatives, which resulted with a hydrogen ion in the beta-carbon of cysteine replaced by the methyl group. In addition to chelation of heavy

  5. Gas Sensing Mechanism of Gold Nanoparticles Decorated Single-Walled Carbon Nanotubes

    E-Print Network [OSTI]

    Gas Sensing Mechanism of Gold Nanoparticles Decorated Single- Walled Carbon Nanotubes Syed Mubeen towards different gas analytes, however the sensing mechanism was not clearly elucidated. The detailed demonstration of single-walled carbon nanotubes (SWNTs) as highly sensitive gas sensors [1], there have been

  6. FY2014 Parameters for Gold Ions in Booster, AGS, and RHIC

    SciTech Connect (OSTI)

    Gardner, C. J.

    2014-07-30

    The nominal parameters for gold ions in Booster, AGS, and RHIC are given for the FY2014 running period. The parameters are worked out using various formulas to derive mass, kinetic parameters, RF parameters, ring parameters, etc.. The ''standard setup'', ''medium-energy'', and ''low-energy'' parameters are summarized in separate sections.

  7. FY2014 Parameters for Helions and Gold Ions in Booster, AGS, and RHIC

    SciTech Connect (OSTI)

    Gardner, C. J.

    2014-08-15

    The nominal parameters for helions (helion is the bound state of two protons and one neutron, the nucleus of a helium-3 atom) and gold ions in Booster, AGS, and RHIC are given for the FY2014 running period. The parameters are found using various formulas to derive mass, helion anomalous g-factor, kinetic parameters, RF parameters, ring parameters, etc..

  8. Copyright by Ming Zhang, 2003 THERMAL PROPERTIES OF INDIUM NANOPARTICLES AND GOLD SILICIDE

    E-Print Network [OSTI]

    Allen, Leslie H.

    SILICIDE FORMATION BY SCANNING NANOCALORIMETRY BY MING ZHANG B. Engr., Tsinghua University, 1996 M. Engr of Illinois at Urbana-Champaign, 2003 Urbana, Illinois #12;iii THERMAL PROPERTIES OF INDIUM NANOPARTICLES AND GOLD SILICIDE FORMATION BY SCANNING NANOCALORIMETRY Ming Zhang Department of Material Science

  9. Recycling Size Exclusion Chromatography for the Analysis and Separation of Nanocrystalline Gold

    E-Print Network [OSTI]

    Aazhang, Behnaam

    fractions reveals that these peaks correspond to distinct populations of gold nanoparticles with narrowly nanocrystals are among their most important attributes. Characteristics ranging from the nanoparticle melting quantum dots,8-10 magnetic iron oxides,11-13 and other noble metals, show great tunability in properties

  10. GoldLink Finance Account Request ETSU Office of Information Technology

    E-Print Network [OSTI]

    Karsai, Istvan

    GoldLink Finance Account Request Form ETSU Office of Information Technology 424 Roy Nicks Hall, Box 70728 Johnson City, Tennessee 37614 (423) 439-4648 · oithelp@etsu.edu This section for use by the Office _______________________________________________________________________________________ [ last ] [ first ] [ middle ] ETSU Domain Name ____________________@etsu.edu School / College

  11. Preparation of supported gold nanoparticles by a modified incipient wetness impregnation method

    E-Print Network [OSTI]

    Boyer, Edmond

    procedure of impregnation of oxide supports with chloroauric acid, which is well-known to lead to large gold Paris Cedex 05, France Running title: Modified method of impregnation of Au/oxide Figures: 8 Tables: 3 after a treatment of calcination at 300°C on any type of oxide supports (alumina, titania, silica

  12. Asymmetric Catalysis at the Mesoscale: Gold Nanoclusters Embedded in Chiral Self-Assembled Monolayer as Heterogeneous

    E-Print Network [OSTI]

    Asymmetric Catalysis at the Mesoscale: Gold Nanoclusters Embedded in Chiral Self of the catalytically active metallic sites and the surrounding chiral SAM for the formation of a mesoscale the catalytically active site from the nanoscale to the mesoscale, which implies a principle of operating systems

  13. Silicone oil contamination and electrical contact resistance degradation of low-force gold contacts.

    SciTech Connect (OSTI)

    Dugger, Michael Thomas; Dickrell, Daniel John, III

    2006-02-01

    Hot-switched low-force gold electrical contact testing was performed using a nanomechanical test apparatus to ascertain the sensitivity of simulated microelectromechanical systems (MEMS) contact to silicone oil contamination. The observed cyclic contact resistance degradation was dependent on both closure rate and noncontact applied voltage. The decomposition of silicone oil from electrical arcing was hypothesized as the degradation mechanism.

  14. Z .Chemical Geology 157 1999 219234 z /Quantifying the platinum group elements PGEs and gold in

    E-Print Network [OSTI]

    Z .Chemical Geology 157 1999 219­234 z /Quantifying the platinum group elements PGEs and gold in geological samples using cation exchange pretreatment and ultrasonic nebulization inductively coupled plasma Department of CiÕil Engineering and Geological Sciences, UniÕersity of Notre Dame, Notre Dame, IN 46556

  15. Thomas Sommer gewinnt zweimal Gold bei der German Open Poomsae 2011

    E-Print Network [OSTI]

    Pinnau, René

    Thomas Sommer gewinnt zweimal Gold bei der German Open Poomsae 2011 Mit der Poomsae-Union Rheinland-Pfalz (TURP) stellte sich auch der zweifache WM- Bronzemedaillengewinner Thomas Sommer der im Paarwettbewerb wollte Thomas Sommer mit Cyra De Rama nach einer Goldmedaille greifen und damit für

  16. A Java Library Implementation of the Gold-Food Economic Model in Repast and MASON

    E-Print Network [OSTI]

    Tesfatsion, Leigh

    1 A Java Library Implementation of the Gold-Food Economic Model in Repast and MASON Christopher K, 2008 Abstract We present a robust, extensible Java library for agent-based economic simulations et al. [8]. We implement the library on top of both the Repast and MASON agent-based Java toolkits

  17. Adsorption of gold cyanide complexes by activated carbon on non-coconut shell origin

    SciTech Connect (OSTI)

    Yalcin, M.; Arol, A.I. [Middle East Technical Univ., Ankara (Turkey). Mining Engineering Dept.

    1995-12-31

    Coconut shells are the most widely used raw material for the production of activated carbon used in the gold production by cyanide leaching. There have been efforts to find alternatives to coconut shells. Shells and stones of certain fruits, have been tested. Although promising results to some extent were obtained, coconut shells remain the main source of activated carbon. Turkey has become a country of interest in terms of gold deposits of epithermal origin. Four deposits have already been discovered and, mining and milling operations are expected to start in the near future. Explorations are underway in many other areas of high expectations. Turkey is also rich in fruits which can be a valuable source of raw material for activated carbon production. In this study, hazelnut shells, peach and apricot stones, abundantly available locally, have been tested to determine whether they are suitable for the gold metallurgy. Parameters of carbonization and activation have been optimized. Gold loading capacity and adsorption kinetics have been studied.

  18. The Influence of shearing and rotary inertia on the resonant properties of gold nanowires

    E-Print Network [OSTI]

    Park, Harold S.

    The Influence of shearing and rotary inertia on the resonant properties of gold nanowires Pär A. T, SE-221 00 Lund, Sweden 2 Department of Mechanical Engineering, Boston University, Boston of shearing and rotary inertia for higher order resonant modes. Furthermore, we argue that this type

  19. Centrifugal Shape Sorting of Faceted Gold Nanoparticles Using an Atomic Plane-Selective Surfactant

    E-Print Network [OSTI]

    Gao, Hongjun

    Centrifugal Shape Sorting of Faceted Gold Nanoparticles Using an Atomic Plane-Selective Surfactant control or postsynthetic processing that relies on centrifugal sedimentation-based sorting schemes whereNPs possessing different shapes that would otherwise be virtually indistinguishable during centrifugal

  20. Laser-assisted scanning probe alloying nanolithography (LASPAN) and its application in gold-silicon system 

    E-Print Network [OSTI]

    Peng, Luohan

    2009-05-15

    alloying nanolithography (LASPAN), to fabricate well-defined nanostructures in gold-silicon (Au-Si) system. As a result, four aspects of nanostructures were made through different experimental trials. A non-equilibrium phase (AuSi3) was discovered, along...

  1. Lessons Learned from Continuous Commissioning® of a LEED Gold Building in Texas 

    E-Print Network [OSTI]

    Bynum, J.; Claridge, D. E.

    2008-09-22

    The subject building is a relatively new building with 120,000 square feet located in Texas and was the first LEED® Gold building in the area. To earn the title of a green building, the designers of this high performance building included many...

  2. The A.J. Goddard: Reconstruction and Material Culture of a Klondike Gold Rush Sternwheeler 

    E-Print Network [OSTI]

    Thomas, Lindsey Hall

    2012-10-19

    The A.J. Goddard, a steamboat built for the Klondike Gold Rush of 1897-1898, wrecked in 1901 on Lake Laberge, Yukon Territory, where it lay undisturbed until its rediscovery in 2008 by the Yukon River Survey Project, directed by John Pollack...

  3. Continuous Commissioning of a LEED-EB Gold Certified Office Building 

    E-Print Network [OSTI]

    McCown, P.

    2009-01-01

    A 320,000 square foot Class A high-rise office building in Nashville, TN achieved LEED-EB Gold Certification. LEED-EB version 2.0 was utilized, which requires Retro-Commissioning (RCx) as a prerequisite for certification. SSRCx performed the RCx...

  4. Evolution of Size and Shape in the Colloidal Crystallization of Gold Nanoparticles

    E-Print Network [OSTI]

    Osterloh, Frank

    Evolution of Size and Shape in the Colloidal Crystallization of Gold Nanoparticles Owen C. Compton to aggregation of nanoparticles and formation of colloidal crystals. Based on results from dynamic light, or colloidal crystals, continues to be of great academic and technical interest.1-9 Demonstrated uses

  5. Gold Nanorods & Photothermal Heating Breast cancer cells incubated with 2-NBDG will have increased fluorescence

    E-Print Network [OSTI]

    in cell lines responsive to such therapeutics. · The presence of gold nanoparticles alone will not have. Vol. 89, pp. 1271-1275. Feb. 1992. [5] Walsh, Alex J., and Melissa C. Skala. "An automated image, Danhier P, Gallez B, et al. (2010) NADPH oxidase-mediated reactive oxygen species production activates

  6. Current generation by helicons and lower hybrid waves in modern tokamaks and reactors ITER and DEMO. Scenarios, modeling and antennae

    SciTech Connect (OSTI)

    Vdovin, V. L., E-mail: vdov@nfi.kiae.ru [National Research Centre 'Kurchatov Institute,' (Russian Federation)

    2013-02-15

    The innovative concept and 3D full-wave code modeling the off-axis current drive by radio-frequency (RF) waves in large-scale tokamaks, ITER and DEMO, for steady-state operation with high efficiency is proposed. The scheme uses the helicon radiation (fast magnetosonic waves at high (20-40) ion cyclotron frequency harmonics) at frequencies of 500-700 MHz propagating in the outer regions of the plasmas with a rotational transform. It is expected that the current generated by helicons, in conjunction with the bootstrap current, ensure the maintenance of a given value of the total current in the stability margin q(0) {>=} 2 and q(a) {>=} 4, and will help to have regimes with a negative magnetic shear and internal transport barrier to ensure stability at high normalized plasma pressure {beta}{sub N} > 3 (the so-called advanced scenarios) of interest for the commercial reactor. Modeling with full-wave three-dimensional codes PSTELION and STELEC showed flexible control of the current profile in the reactor plasmas of ITER and DEMO, using multiple frequencies, the positions of the antennae and toroidal wave slow down. Also presented are the results of simulations of current generation by helicons in the DIII-D, T-15MD, and JT-60AS tokamaks. Commercially available continuous-wave klystrons of the MW/tube range are promising for commercial stationary fusion reactors. The compact antennae of the waveguide type are proposed, and an example of a possible RF system for today's tokamaks is given. The advantages of the scheme (partially tested at lower frequencies in tokamaks) are a significant decline in the role of parametric instabilities in the plasma periphery, the use of electrically strong resonator-waveguide type antennae, and substantially greater antenna-plasma coupling.

  7. The Genomes On Line Database (GOLD) in 2007: status of genomic and metagenomic projects and their associated metadata

    SciTech Connect (OSTI)

    Fenner, Marsha W; Liolios, Konstantinos; Mavromatis, Konstantinos; Tavernarakis, Nektarios; Kyrpides, Nikos C.

    2007-12-31

    The Genomes On Line Database (GOLD) is a comprehensive resource of information for genome and metagenome projects world-wide. GOLD provides access to complete and ongoing projects and their associated metadata through pre-computed lists and a search page. The database currently incorporates information for more than 2900 sequencing projects, of which 639 have been completed and the data deposited in the public databases. GOLD is constantly expanding to provide metadata information related to the project and the organism and is compliant with the Minimum Information about a Genome Sequence (MIGS) specifications.

  8. Resonant bowtie aperture nano-antenna for the control of optical nanocavities resonance

    E-Print Network [OSTI]

    Baida, Fadi Issam

    2015-01-01

    Scanning Near-field Optical Microscopy (SNOM) has been successful in finely tuning the optical properties of photonic crystal (PC) nanocavities. The SNOM nanoprobes proposed so far allowed for either redshifting or blueshifting the resonance peak of the PC structures. In this Letter, we theoretically demonstrate the possibility of redshifting (up to +0.65nm) and blueshifting (up to $-5$~nm) PC cavity resonance with a single SNOM probe. This probe is obtained by opening a bowtie-aperture nano-antenna (BNA) at the apex of a metal-coated tip. This double-way PC tunability is the result of a competition between the effects of the BNA resonance (induced electric dipole leading to a redshift) and the metal-coated tip (induced magnetic dipole giving rise to a blueshift) onto the PC mode volume. The sign of the spectral shift is modified by simply controlling the tip-to-PC distance. This study opens the way to the full postproduction control of the resonance wavelength of high quality factor optical cavities.

  9. Two physical regimes for the Giant HII Regions and Giant Molecular Clouds in the Antennae Galaxies

    E-Print Network [OSTI]

    Zaragoza-Cardiel, Javier; Beckman, John E; García-Lorenzo, Begoña; Erroz-Ferrer, Santiago; Gutiérrez, Leonel

    2014-01-01

    We have combined observations of the Antennae galaxies from the radio interferometer ALMA (Atacama Large Millimetre/submillimetre Array) and from the optical interferometer GH$\\alpha$FaS (Galaxy Halpha Fabry-Perot System). The two sets of observations have comparable angular and spectral resolutions, enabling us to identify 142 giant molecular clouds and 303 HII regions. We have measured, and compare, their basic physical properties (radius, velocity dispersion, luminosity). For the HII regions we find two physical regimes, one for masses $>10^{5.4} \\mathrm{M_{\\odot}}$ of ionized gas, which the gas density increases with gas mass, the other for masses $<10^{5.4} \\mathrm{M_{\\odot}}$ of ionized gas where the gas density decreases with gas mass. For the GMCs we find, in contrast to previous studies in other galaxies over a generally lower mass range of clouds, that the gas density increases with the total gas mass, hinting at two regimes for these clouds if we consider both sources of data. We also find that ...

  10. Hyperbolic-metamaterial antennas for broadband enhancement of dipole emission to free space

    SciTech Connect (OSTI)

    Valagiannopoulos, C. A.; Mirmoosa, M. S.; Nefedov, I. S.; Tretyakov, S. A.; Simovski, C. R.

    2014-10-28

    Dipole emitters used in nano optics and nanophotonics (e.g., fluorescent molecules or quantum dots) are weak radiators and thus detecting the radiation of a single emitter gets possible only if it is significantly enhanced. For this enhancement, one often utilizes resonant nanoantennas (Purcell's effect); this method, however, requires the exact knowledge of source location and radiation frequency which constitute a significant drawback. One known possibility for broadband location-insensitive radiation enhancement is to use a layer of the so-called hyperbolic metamaterial. However, the enhanced radiated energy is mainly directed into the volume of the lossy medium, where it is lost to heating. In this work, we suggest specific shapes of macroscopic hyperbolic metamaterial samples to open radiation windows for enhanced radiation to free space. We show that hyperbolic media slabs with properly shaped macroscopic grooves convert the evanescent waves produced by a dipole into waves traveling in free space, which results in the enhancement of useful radiation by one to two orders of magnitude. That level of enhancement of radiation into free-space which is also wideband and of non-resonant nature has not been reported up to now. These results may open possibilities for realization of broadband and directive antennas, where the primary radiators are randomly positioned fluorescent molecules or quantum dots.

  11. TH-E-BRD-01: Innovation in (gold) Nanoparticle-Enhanced Therapy

    SciTech Connect (OSTI)

    Krishnan, S; Chithrani, B; Berbeco, R

    2014-06-15

    Radiation therapy relies on the concept of delivering high dose to tumor volumes whilst simultaneously aiming to minimize irradiation of healthy tissue. Gold and other metallic nanoparticles (GNPs) have the potential to greatly enhance dose depositions in their close proximity. While it was originally thought that this effect would only be significant for kV photon beams, it has been shown that GNPs also enhance dose and increase cell killing and survival fraction for MV photons as well as protons. GNPs have been shown to be preferentially taken up in tumors, depending on the GNP properties either internalized in the tumor cells or clustering in the tumor vasculature. Therefore GNPs offer an intriguing additional option to target the tumor while sparing healthy tissue. While a growing amount of research shows GNP induced enhancement factors in the order of 1.5 and higher, GNPs have not yet entered into clinical routine. In this symposium we will have three presentations discussing the current status of GNP based research, the potential to include GNPs in radiation therapy and the limitations and problems to use GNPs in the clinic. Physical and biological underpinnings of radiosensitization with gold nano particles An evolving body of recent literature alludes to the potential to sensitize tumors to radiation therapy using metallic nanoparticles. In preclinical studies, the techniques that hold promise for eventual clinical deployment are nanoparticle-assisted radiation dose enhancement and hyperthermic radiosensitization. To understand the underlying nanoparticle-radiation interactions, computational techniques offer an explanation for and predict the biophysical consequences at a nano-/meso-scopic scale. Nonetheless, there are persisting gaps in knowledge relating to the molecular mechanism of action of these radiosensitization approaches — some of these issues will be addressed. Since the literature relating to the diverse disciplines involved in these efforts spans across multiple specialties (clinical radiation oncology, radiation physics, radiation biology, nanotechnology, material science, biomedical engineering, pharmacology, chemistry, and tumor biology) and numerous specialty journals, there is no single compilation of extant research in this arena or forum for merging analogous concepts and paradigms. This symposium will provide such a venue — my presentation will start with familiarizing the audience with the potential applications of metallic nanoparticles in radiation therapy using specific illustrative examples and begin to explore ways to understand the underlying mechanisms of the effects observed. Biological effects of Gold nanoparticles in radiation therapy Gold nanoparticles (GNP) have been investigated as platforms to carry drugs or radio-sensitizing agents to tumors due to the biocompatibility of gold and relative ease of conjugation with therapeutic and targeting moieties. Recently, there has been interest in exploiting the physical properties of gold, specifically the high atomic number, to enhance radiation therapy. When irradiated, gold atoms will produce low energy electrons, depositing energy within a short distance. The ratio of dose deposited in the presence of the GNP to the dose deposited in the absence of GNP is referred to as the dose enhancement factor (DEF). This factor has been shown to depend on the concentration of GNP and the energy of the incident photons. The physics of this process, preliminary in vitro and in vivo experiments and future directions for this nascent field are described in this presentation. Gold Nanoparticles for improved therapeutic outcome in radiation therapy The application of nanoparticles (NPs) for improved therapeutics is at the forefront of cancer nanotechnology. Among other NP systems, gold nanoparticles (GNPs) are extensively used due to its impressive ability to act as both an anticancer drug carrier in chemotherapy and as a dose enhancer in radiotherapy. Cellular uptake of GNPs was dependent on their size. Among GNPs of diameter between 14–74 nm,

  12. Cationic Gold Clusters Ligated with Differently Substituted Phosphines: Effect of Substitution on Ligand Reactivity and Binding

    SciTech Connect (OSTI)

    Johnson, Grant E.; Olivares, Astrid M.; Hill, David E.; Laskin, Julia

    2015-01-01

    We present a systematic study of the effect of the number of methyl (Me) and cyclohexyl (Cy) functional groups in monodentate phosphine ligands on the solution-phase synthesis of ligated sub-nanometer gold clusters and their gas-phase fragmentation pathways. Small mixed ligand cationic gold clusters were synthesized using ligand exchange reactions between pre-formed triphenylphosphine ligated (PPh3) gold clusters and monodentate Me- and Cy-substituted ligands in solution and characterized using electrospray ionization mass spectrometry (ESI-MS) and collision-induced dissociation (CID) experiments. Under the same experimental conditions, larger gold-PPh3 clusters undergo efficient exchange of unsubstituted PPh3 ligands for singly Me- and Cy-substituted PPh2Me and PPh2Cy ligands. The efficiency of ligand exchange decreases with an increasing number of Me or Cy groups in the substituted phosphine ligands. CID experiments performed for a series of ligand-exchanged gold clusters indicate that loss of a neutral Me-substituted ligand is preferred over loss of a neutral PPh¬3 ligand while the opposite trend is observed for Cy-substituted ligands. The branching ratio of the competing ligand loss channels is strongly correlated with the electron donating ability of the phosphorous lone pair as determined by the relative proton affinity of the ligand. The results indicate that the relative ligand binding energies increase in the order PMe3 < PPhMe2 < PPh2Me < PPh3< PPh2Cy < PPhCy2< PCy3. Furthermore, the difference in relative ligand binding energies increases with the number of substituted PPh3-mMem or PPh3-mCym ligands (L) exchanged onto each cluster. This study provides the first experimental determination of the relative binding energies of ligated gold clusters containing differently substituted monophosphine ligands, which are important to controlling their synthesis and reactivity in solution. The results also indicate that ligand substitution is an important parameter that must be considered in theoretical modeling of these complex systems

  13. Propane reacts with O2 and H2 on gold supported TS-1 to form oxygenates with high selectivity

    E-Print Network [OSTI]

    Bravo Suarez, Juan J.

    2008-06-13

    Gold nanoparticles supported on a microporous titanosilicate (TS-1) were found to be highly selective (95%) towards the formation of acetone and isopropanol from propane, O2, and H2 at moderate temperatures (443 K)....

  14. Room temperature reaction of oxygen with gold: an in situ ambient-pressure X-ray photoelectron spectroscopy investigation

    SciTech Connect (OSTI)

    Jiang, Peng; Porsgaard, Soeren; Borondics, Ferenc; Kober, Mariana; Caballero, Alfonso; Bluhm, Hendrik; Besenbacher, Flemming; Salmeron, Miquel

    2010-02-01

    Gold is commonly regarded as the most inert element.1 However, the discovery of the exceptional catalytic properties of gold nanoparticles (NPs) for low temperature CO oxidation2 initiated great interest due to its promising applications and spawned a large number of studies devoted to the understanding of the reaction mechanism.3-6 Nevertheless, no consistent and conclusive picture has arisen.7-13

  15. A Review of "New World Gold: Cultural Anxiety and Monetary Disorder in Early Modern Spain" by Elvira Vilches 

    E-Print Network [OSTI]

    Wright, Elizabeth R.

    2011-01-01

    and of recent work on the early Enlightenment. Elvira Vilches. New World Gold: Cultural Anxiety and Monetary Disorder in Early Modern Spain. Chicago: University of Chicago Press, 2010. xi + 361 pp. $45. Review by elizabeth r. wright, university of georgia.... The six chapters of New World Gold attest to an ambitious, pre- scient and impressively executed research project, in which Elvira Vilches combined the analytical tools of a cultural critic and an economic historian. At its heart is a question...

  16. Highly Nonlinear Luminescence Induced by Gold Nanoparticles on Glass Surfaces with Continuous-Wave Laser Illumination

    E-Print Network [OSTI]

    Wu, Yong; Toro, Ligia; Stefani, Enrico

    2015-01-01

    We report on highly nonlinear luminescence being observed from individual spherical gold nanoparticles immobilized on a borosilicate glass surface and illuminated by continuous-wave (CW) lasers with relatively low power. The nonlinear luminescence shows optical super-resolution beyond the diffraction limit in three dimensions compared to the scatting of the excitation laser light. The luminescence intensity from most nanoparticles is proportional to the 5th--7th power of the excitation laser power and has wide excitation and emission spectra across the visible wavelength range. Strong nonlinear luminescence is only observed near the glass surface. High optical nonlinearity excited by low CW laser power is related to a long-lived dark state of the gold nanoparticles, where the excitation light is strongly absorbed. This phenomenon has potential biological applications in super-resolution and deep tissue imaging.

  17. Gold and palladium adsorption from leached electronic scrap using ordered mesoporous carbon nanoscaffolds

    SciTech Connect (OSTI)

    McDowell, Rocklan; Dutech, Guy

    2014-09-01

    Ordered mesoporous carbon (OMC) nanoscaffolds are engineered agglomerates of carbon nanotubes held together by small carbon nanofibers with uniform pore sizes, high pore volume, and high channel permeability. These materials exhibit very high affinity for the adsorption of gold from aqueous acidic mixtures. The efficiency of gold recovery is comparable to those typically accomplished using biopolymer-based adsorbents. The adsorption efficiency for other precious metals such as palladium and platinum is lower. Studies on the precious metal (Au, Pd) adsorption on OMC materials from actual liquors of leached electronics will be presented. Adsorption properties will be compared for several different sorbents used for the recovery of precious metals. The leach liquor compositions for three different types of electronic scrap materials (personal computer board, cell phone and tv input/output board) will be presented. The sorption efficiencies for Au, Pd, together with a spectrum of competing and non-competing metals, from such leach mixtures will be compared.

  18. High resolution transmission electron microscopic in-situ observations of plastic deformation of compressed nanocrystalline gold

    SciTech Connect (OSTI)

    Wang, Guoyong; Lian, Jianshe; Jiang, Qing; Sun, Sheng; Zhang, Tong-Yi

    2014-09-14

    Nanocrystalline (nc) metals possess extremely high strength, while their capability to deform plastically has been debated for decades. Low ductility has hitherto been considered an intrinsic behavior for most nc metals, due to the lack of five independent slip systems actively operating during deformation in each nanograin. Here we report in situ high resolution transmission electron microscopic (HRTEM) observations of deformation process of nc gold under compression, showing the excellent ductility of individual and aggregate nanograins. Compression causes permanent change in the profile of individual nanograins, which is mediated by dislocation slip and grain rotation. The high rate of grain boundary sliding and large extent of widely exited grain rotation may meet the boundary compatibility requirements during plastic deformation. The in situ HRTEM observations suggest that nc gold is not intrinsically brittle under compressive loading.

  19. Gold–promoted structurally ordered intermetallic palladium cobalt nanoparticles for the oxygen reduction reaction

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kuttiyiel, Kurian A.; Sasaki, Kotaro; Su, Dong; Wu, Lijun; Zhu, Yimei; Adzic, Radoslav R.

    2014-11-06

    Considerable efforts to make palladium and palladium alloys active catalysts and a possible replacement for platinum have had a marginal success. Here, we report on a structurally ordered Au??Pd??Co?? catalyst that exhibits comparable activity to conventional platinum catalysts in both acid and alkaline media. Electron microscopic techniques demonstrate that via addition of gold atoms PdCo nanoparticles undergo at elevated temperatures an atomic structural transition from core-shell to a rare intermetallic ordered structure with twin boundaries forming stable {111}, {110} and {100} facets. The superior stability of this catalyst compared to platinum after 10,000 potential cycles in alkaline media is attributedmore »to the atomic structural order of PdCo nanoparticles along with protective effect of clusters of gold atoms on the surface. This strategy of making ordered palladium intermetallic alloy nanoparticles can be used in diverse heterogeneous catalysis where particle size and structural stability matters.« less

  20. Benchmark Measurements of the Ionization Balance of Non-LTE Gold

    SciTech Connect (OSTI)

    Heeter, R F; Hansen, S B; Fournier, K B; Foord, M E; Froula, D H; Mackinnon, A J; May, M J; Schneider, M B; Young, B F

    2007-04-20

    The authors present a series of benchmark measurements of the ionization balance of well characterized gold plasmas with and without external radiation fields at electron densities near 10{sup 21} cm{sup -3} and various electron temperatures spanning the range 0.8 to 2.4 keV. They have analyzed time- and space-resolved M-shell gold emission spectra using a sophisticated collisional-radiative model with hybrid level structure, finding average ion changes ranging from 42 to 50. At the lower temperatures, the spectra exhibit significant sensitivity to external radiation fields and include emission features from complex N-shell ions not previously studied at these densities. The measured spectra and inferred provide a stringent test for non-local thermodynamic equilibrium (non-LTE) models of complex high-Z ions.

  1. Gold–promoted structurally ordered intermetallic palladium cobalt nanoparticles for the oxygen reduction reaction

    SciTech Connect (OSTI)

    Kuttiyiel, Kurian A.; Sasaki, Kotaro; Su, Dong; Wu, Lijun; Zhu, Yimei; Adzic, Radoslav R.

    2014-11-06

    Considerable efforts to make palladium and palladium alloys active catalysts and a possible replacement for platinum have had a marginal success. Here, we report on a structurally ordered Au??Pd??Co?? catalyst that exhibits comparable activity to conventional platinum catalysts in both acid and alkaline media. Electron microscopic techniques demonstrate that via addition of gold atoms PdCo nanoparticles undergo at elevated temperatures an atomic structural transition from core-shell to a rare intermetallic ordered structure with twin boundaries forming stable {111}, {110} and {100} facets. The superior stability of this catalyst compared to platinum after 10,000 potential cycles in alkaline media is attributed to the atomic structural order of PdCo nanoparticles along with protective effect of clusters of gold atoms on the surface. This strategy of making ordered palladium intermetallic alloy nanoparticles can be used in diverse heterogeneous catalysis where particle size and structural stability matters.

  2. Modeled Neutron Induced Nuclear Reaction Cross Sections for Radiochemistry in the region of Iriduim and Gold

    SciTech Connect (OSTI)

    Hoffman, R D; Dietrich, F S; Kelley, K; Escher, J; Bauer, R; Mustafa, M

    2008-02-26

    We have developed a set of modeled nuclear reaction cross sections for use in radiochemical diagnostics. Systematics for the input parameters required by the Hauser-Feshbach statistical model were developed and used to calculate neutron induced nuclear reaction cross sections for targets ranging from osmium (Z = 76) to gold (Z = 79). Of particular interest are the cross sections on Ir and Au including reactions on isomeric targets.

  3. Radioactive gold in the treatment of bovine ocular squamous carcinoma and its precursor lesions 

    E-Print Network [OSTI]

    England, Roy Belvin

    1973-01-01

    A&M University D. V. M. , Texas A&M University Directed by: Dr. M. C. Banks Ten cases of clinically diagnosed bovine ocular carcinoma were treated by implanting radioactive gold seeds into the lesions with a needle and stylet. Progress films... were made at regular intervals during a 6 months convalescent period to record any changes resulting from this treatment. In 6 of 10 cases, total or near total regression occurred, while temporary regression and subsequent proliferation...

  4. Electrochemical method of controlling thiolate coverage on a conductive substrate such as gold

    DOE Patents [OSTI]

    Porter, Marc D. (Ames, IA); Weisshaar, Duane E. (Sioux Falls, SD)

    1998-10-27

    An electrochemical method for forming a partial monomolecular layer of a predetermined extent of coverage of a thiolate of the formula, XRS--, therein R can be a linear or branched chain hydrocarbon or an aromatic or the like and X can be any compatible end group, e.g., OH, COOH, CH.sub.3 or the like, upon a substrate such as gold, which involves applying in an electrochemical system a constant voltage preselected to yield the desired predetermined extent of coverage.

  5. Explorations of Functionalized Gold Nanoparticle Surface Chemistry for Laser Desorption Ionization Mass Spectrometry Applications 

    E-Print Network [OSTI]

    Gomez Hernandez, Mario 1980-

    2012-07-11

    -MS Matrix Assisted Laser Desorption Ionization Mass Spectrometry AuNPs Gold Nanoparticles UV-Vis Ultraviolet-Visible Spectroscopy TEM Transmission Electron Microscopy NMR Nuclear Magnetic Resonance Spectroscopy RIY Relative Ion... including enhanced Rayleigh scattering,2 biological reaction catalysis,3 aggregation assays,4 surface enhanced Raman spectroscopy,5 and other applications known as nanobiotechnology.6 Therefore, it is the combination of the proven performance of mass...

  6. Ultrafast Non-linear Response of Gold Gyroid 3D Metamaterials

    E-Print Network [OSTI]

    Farah, Petros; Demetriadou, Angela; Salvatore, Stefano; Vignolini, Silvia; Stefik, Morgan; Wiesner, Ulrich; Hess, Ortwin; Steiner, Ullrich; Valev, Ventsi; Baumberg, Jeremy J.

    2014-10-07

    , University of Cambridge, Cambridge, CB3 0HE, UK 2 Department of Chemistry, Imperial College London, London, SW7 2AZ, United Kingdom 3 Department of Materials Science and Engineering Cornell University, Ithaca, New York 14853, USA 4 Blackett Laboratory... -? nanostructures induce magnetic fields opposing their motion, which govern the effective macro- scopic optical behaviour of the structure. It was recently shown [21, 23, 25] that gold gyroid films behave as an ar- tificial chiral plasma, with a Drude...

  7. Millifluidics for time-resolved mapping of the growth of gold nanostructures

    SciTech Connect (OSTI)

    Sai Krishna, Katla; Navin, Chelliah; Biswas, Sanchita; Singh, Varshni; Ham, Kyungmin; Bovencamp, L. S.; Theegala, Chandra; Miller, Jeffrey T; Spivey, James J.; Kumar, Challa S.S.R.

    2013-04-10

    Innovative in situ characterization tools are essential for understanding the reaction mechanisms leading to the growth of nanoscale materials. Though techniques, such as in situ transmission X-ray microscopy, fast single-particle spectroscopy, small-angle X-ray scattering, etc., are currently being developed, these tools are complex, not easily accessible, and do not necessarily provide the temporal resolution required to follow the formation of nanomaterials in real time. Here, we demonstrate for the first time the utility of a simple millifluidic chip for an in situ real time analysis of morphology and dimension-controlled growth of gold nano- and microstructures with a time resolution of 5 ms. The structures formed were characterized using synchrotron radiation-based in situ X-ray absorption spectroscopy, 3-D X-ray tomography, and high-resolution electron microscopy. These gold nanostructures were found to be catalytically active for conversion of 4-nitrophenol into 4-aminophenol, providing an example of the potential opportunities for time-resolved analysis of catalytic reactions. While the investigations reported here are focused on gold nanostructures, the technique can be applied to analyze the time-resolved growth of other types of nanostructured metals and metal oxides. With the ability to probe at least a 10-fold higher concentrations, in comparison with traditional microfluidics, the tool has potential to revolutionize a broad range of fields from catalysis, molecular analysis, biodefense, and molecular biology.

  8. Visualization of expanding warm dense gold and diamond heated rapidly by laser-generated ion beams

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Bang, W.; Albright, B. J.; Bradley, P. A.; Gautier, D. C.; Palaniyappan, S.; Vold, E. L.; Cordoba, M. A. Santiago; Hamilton, C. E.; Fernández, J. C.

    2015-09-22

    With the development of several novel heating sources, scientists can now heat a small sample isochorically above 10,000 K. Although matter at such an extreme state, known as warm dense matter, is commonly found in astrophysics (e.g., in planetary cores) as well as in high energy density physics experiments, its properties are not well understood and are difficult to predict theoretically. This is because the approximations made to describe condensed matter or high-temperature plasmas are invalid in this intermediate regime. A sufficiently large warm dense matter sample that is uniformly heated would be ideal for these studies, but has beenmore »unavailable to date. We have used a beam of quasi-monoenergetic aluminum ions to heat gold and diamond foils uniformly and isochorically. For the first time, we visualized directly the expanding warm dense gold and diamond with an optical streak camera. Furthermore, we present a new technique to determine the initial temperature of these heated samples from the measured expansion speeds of gold and diamond into vacuum. We anticipate the uniformly heated solid density target will allow for direct quantitative measurements of equation-of-state, conductivity, opacity, and stopping power of warm dense matter, benefiting plasma physics, astrophysics, and nuclear physics.« less

  9. Enhancing DNA binding rate using optical trapping of high-density gold nanodisks

    SciTech Connect (OSTI)

    Lin, En-Hung; Pan, Ming-Yang [Institute of Photonics Technologies, National Tsing Hua University, Hsinchu, Taiwan 30013 (China) [Institute of Photonics Technologies, National Tsing Hua University, Hsinchu, Taiwan 30013 (China); Research Center for Applied Sciences, Academia Sinica, Taipei, Taiwan 11529 (China); Lee, Ming-Chang [Institute of Photonics Technologies, National Tsing Hua University, Hsinchu, Taiwan 30013 (China)] [Institute of Photonics Technologies, National Tsing Hua University, Hsinchu, Taiwan 30013 (China); Wei, Pei-Kuen, E-mail: pkwei@sinica.edu.tw [Research Center for Applied Sciences, Academia Sinica, Taipei, Taiwan 11529 (China) [Research Center for Applied Sciences, Academia Sinica, Taipei, Taiwan 11529 (China); Institute of Biophotonics, National Yang-Ming University, Taipei 11221, Taiwan (China)

    2014-03-15

    We present the dynamic study of optical trapping of fluorescent molecules using high-density gold nanodisk arrays. The gold nanodisks were fabricated by electron beam lithography with a diameter of 500 nm and a period of 1 ?m. Dark-field illumination showed ?15 times enhancement of fluorescence near edges of nanodisks. Such enhanced near-field generated an optical trapping force of ?10 fN under 3.58 × 10{sup 3} W/m{sup 2} illumination intensity as calculated from the Brownian motions of 590 nm polystyrene beads. Kinetic observation of thiolated DNA modified with Cy5 dye showed different binding rates of DNA under different illumination intensity. The binding rate increased from 2.14 × 10{sup 3} s{sup ?1} (I = 0.7 × 10{sup 3} W/m{sup 2}) to 1.15 × 10{sup 5} s{sup ?1} (I = 3.58 × 10{sup 3} W/m{sup 2}). Both enhanced fluorescence and binding rate indicate that gold nanodisks efficiently improve both detection limit and interaction time for microarrays.

  10. Controlled epitaxial growth of mesoporous silica/gold nanorod nanolollipops and nanodumb-bells

    SciTech Connect (OSTI)

    Huang, Ching-Mao; Chung, Ming-Fang; Lo, Leu-Wei; Souris, Jeffrey S.

    2014-11-01

    In this work, we describe the controlled synthesis of novel heterogeneous nanostructures comprised of mesoporous silica-coated gold nanorods (MSGNRs) in the form of core–shell nanolollipops and nanodumb-bells, using a seed-mediated sol–gel method. Although MSGNR core–shell (?-MSGNR) structures have been reported previously by us and others, we herein discuss the first ever fabrication of MSGNR nanolollipops (?-MSGNR) and nanodumb-bells (?-MSGNR), achieved by simply controlling the aging time of gold nanorods (GNRs), the residual cetyltrimethylammonium bromide (CTAB) coating of GNRs, and the addition of dimethyl formamide during incubation, centrifugation, and sonication, respectively. Transmission electron microscopy revealed two bare GNR isoforms, with aspect ratios of approximately 4 and 6, while scanning electron microscopy was used to further elucidate the morphology of ?-MSGNR and ?-MSGNR heterostructures. In agreement with the smaller dielectric constants afforded by incomplete silica encasement, spectroscopic studies of ?-MSGNR and ?-MSGNR, surface plasmon resonance (SPR) bands revealed 20-40 nm blue shifts relative to the SPR of ?-MSGNR. On the basis of the attributes and applications of more conventional ?-MSGNRs, ?-MSGNRs and ?-MSGNRs are anticipated to provide most of the utility of ?-MSGNRs, but with the additional functionalities that accompany their incorporation of both bare gold and mesoporous silica encased tips; with significant/unique implications for biomedical and catalytic applications.

  11. Non-invasive hyperthermia apparatus including coaxial applicator having a non-invasive radiometric receiving antenna incorporated therein and method of use thereof

    DOE Patents [OSTI]

    Ross, M.P.

    1996-08-27

    A coaxial hyperthermia applicator is disclosed for applying non-invasively electromagnetic energy to a body against which it is placed. The coaxial applicator antenna has formed integrally within it a non-invasive radiometric antenna for receiving thermoelectromagnetic emissions. The coaxial-configured applicator produces a bell-shaped radiation pattern symmetric about the axis of symmetry of the coaxial applicator. Integrating the radiometric antenna within the coaxial applicator produces a single device that performs dual functions. The first function is to transmit non-invasively energy for heating a subcutaneous tumor. The second function is to receive non-invasively thermal electromagnetic radiation from the tumor by which temperature is sensed and fed back to control the output of the coaxial applicator. 11 figs.

  12. Non-invasive hyperthermia apparatus including coaxial applicator having a non-invasive radiometric receiving antenna incorporated therein and method of use thereof

    DOE Patents [OSTI]

    Ross, Michael P. (Albquuerque, NM)

    1996-01-01

    A coaxial hyperthermia applicator for applying non-invasively electromagnetic energy to a body against which it is placed. The coaxial applicator antenna has formed integrally within it a non-invasive radiometric antenna for receiving thermoelectromagnetic emissions. The coaxial-configured applicator produces a bell-shaped radiation pattern symmetric about the axis of symmetry of the coaxial applicator. Integrating the radiometric antenna within the coaxial applicator produces a single device that performs dual functions. The first function is to transmit non-invasively energy for heating a subcutaneous tumor. The second function is to receive non-invasively thermal electromagnetic radiation from the tumor by which temperature is sensed and fed back to control the output of the coaxial applicator.

  13. Environmental Assessment for Leasing Land for the Siting, Construction and Operation of a Commercial AM Radio Antenna at Los Alamos National Laboratory, Los Alamos, NM

    SciTech Connect (OSTI)

    N /A

    2000-02-16

    The United States (U.S.) Department of Energy (DOE) proposes to lease approximately 3 acres of land at the Los Alamos National Laboratory (LANL) on the southeast tip of Technical Area (TA) 54 for the siting, construction and operation of an AM radio broadcasting antenna. This Environmental Assessment (EA) has been developed in order to assess the environmental effects of the Proposed Action and No Action alternative. The Proposed Action includes the lease of land for the siting, construction and operation of an AM radio broadcasting antenna in TA-54, just north of Pajarito Road and State Highway 4. The No Action Alternative was also considered. Under the No Action Alternative, DOE would not lease land on LANL property for the siting and operation of an AM radio broadcasting antenna; the DOE would not have a local station for emergency response use; and the land would continue to be covered in native vegetation and serve as a health and safety buffer zone for TA-54 waste management activities. Other potential sites on LANL property were evaluated but dismissed for reasons such as interference with sensitive laboratory experiments. Potential visual, health, and environmental effects are anticipated to be minimal for the Proposed Action. The radio broadcasting antenna would be visible against the skyline from some public areas, but would be consistent with other man-made objects in the vicinity that partially obstruct viewsheds (e.g. meteorological tower, power lines). Therefore, the net result would be a modest change of the existing view. Electromagnetic field (EMF) emissions from the antenna would be orders or magnitude less than permissible limits. The proposed antenna construction would not affect known cultural sites, but is located in close proximity to two archaeological sites. Construction would be monitored to ensure that the associated road and utility corridor would avoid cultural sites.

  14. ALMA observations of the Antennae galaxies. I. A new window on a prototypical merger

    SciTech Connect (OSTI)

    Whitmore, Bradley C.; Brogan, Crystal; Evans, Aaron; Hibbard, John; Leroy, Adam; Remijan, Anthony; Sheth, Kartik; Chandar, Rupali; Johnson, Kelsey; Privon, George

    2014-11-10

    We present the highest spatial resolution (?0.''5) CO (3-2) observations to date of the 'overlap' region in the merging Antennae galaxies (NGC 4038/39), taken with the Atacama Large Millimeter/submillimeter Array. We report on the discovery of a long (3 kpc), thin (aspect ratio 30/1), filament of CO gas that breaks up into roughly 10 individual knots. Each individual knot has a low internal velocity dispersion (?10 km s{sup –1}); the dispersion of the ensemble of knots in the filament is also low (?10 km s{sup –1}). At the other extreme, we find that the individual clouds in the supergiant molecular cloud 2 region discussed by Wilson and collaborators have a large range of internal velocity dispersions (10 to 80 km s{sup –1}), and a large dispersion among the ensemble (?80 km s{sup –1}). Other large-scale features observed in CO emission, and their correspondence with historical counterparts using observations in other wavelengths, are also discussed. We compare the locations of small-scale CO features with a variety of multi-wavelength observations, in particular broad- (BVIJH) and narrow-band data (H{sub ?} and Pa{sub ?}) taken with the Hubble Space Telescope, and radio (3.6 cm) continuum observations taken with the Karl G. Jansky Very Large Array. This comparison leads to the development of an evolutionary classification system that provides a framework for studying the sequence of star cluster formation and evolution—from diffuse supergiant molecular clouds (SGMCs) to proto, embedded, emerging, young, intermediate/old clusters. The relative timescales have been assessed by determining the fractional population of sources at each evolutionary stage. The main uncertainty in this estimate is the identification of four regions as candidate protoclusters (i.e., strong compact CO emission but no clearly associated radio emission). Using the evolutionary framework, we estimate that the maximum age range of clusters in a single GMC is ?10 Myr, which suggests that the molecular gas is removed over this timescale, resulting in the cessation of star formation and the destruction of the GMC within a radius of about 200 pc.

  15. SU-E-J-247: A Simulation of X-Ray Emission with Gold Nanoparticle Irradiated by Energetic Proton Beam

    SciTech Connect (OSTI)

    Newpower, M; Ahmad, S; Chen, Y [University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States)

    2014-06-01

    Purpose: To investigate the proton induced X-ray emissions in gold-water mixture materials. Methods: In this study a Monte Carlo simulation was created using the GEANT4 toolkit (version 4.9.6). The geometry in this setup includes a 2 cm × 2 cm × 2 cm target, a scoring sphere (radius = 10 cm) and a 65 MeV planar proton source (2 cm × 2 cm). Four concentrations of a gold-water solution were irradiated with 5×10{sup 5} incident protons at a distance of 0.5 cm perpendicular to the surface of the target. The solutions of gold-water mixture had 10%, 5%, 1% and 0.5% of gold by mass, respectively. The number of photon emitting for the target was counted in the scoring sphere for the energy range of 0-86.0 keV in 0.1 keV bins. For this study the reference physics list PhysListEmStandard was used together with the x-ray fluorescence, Auger electron and PIXE (particle induced xray emission) options enabled. The range cuts for photons and electrons were set at 0.5 mm and 1.0 mm, respectively. Results: In the energy spectra of emitting X-ray fluorescence, peaks from gold K shell characteristic x-rays (68.8 and 66.9 keV) were observed. The number of counts under the peaks of Ka1 and Ka2 was found to increase with the increasing of the gold concentrations in the mixture materials. The X-ray yields (for both Ka1 and Ka2) when fitted with least-square method as a function of gold concentration demonstrate a linear dependency with R{sup 2} > 0.96. The Ka1yield per incident proton was found to be 0.0016 for 10% gold-water mixture solutions. Conclusion: This preliminary study with PIXE technique with gold nanoparticle has demonstrated potentials for its utilization in the development of range and dose verification methodology that is currently of great interest in the field of proton radiation therapy.

  16. In-flight calibration of the Cassini-Radio and Plasma Wave Science (RPWS) antenna system for direction-finding and

    E-Print Network [OSTI]

    Gurnett, Donald A.

    In-flight calibration of the Cassini-Radio and Plasma Wave Science (RPWS) antenna system) as well as atmospheric (lightning) origin. The Radio and Plasma Wave Science (RPWS) experiment is designed to measure the full polarization and the wave vector of the incoming radio waves, allowing us to retrieve

  17. The Shoelace Antenna : a device to induce short-wavelength fluctuations in the edge plasma of the Alcator C-Mod Tokamak

    E-Print Network [OSTI]

    Golfinopoulos, Theodore

    2014-01-01

    The "Shoelace" antenna is a unique device built to induce short-wavelength fluctuations in the edge plasma of the Alcator C-Mod tokamak, at a wave number and in the frequency range associated with the Quasi-Coherent Mode ...

  18. ANTENNAS AND WIRELESS PROPAGATION LETTERS, VOL. X, NO. X, JANUARY 2013 1 MRI-derived 3D-printed breast phantom for

    E-Print Network [OSTI]

    Van Veen, Barry D.

    ANTENNAS AND WIRELESS PROPAGATION LETTERS, VOL. X, NO. X, JANUARY 2013 1 MRI-derived 3D-printed--We propose a 3D-printed breast phantom for use in pre-clinical experimental microwave imaging studies the procedure for generating the 3D-printed breast phantom and present the measured dielectric properties

  19. “Smart” Diblock Copolymers as Templates for Magnetic-Core Gold-Shell Nanoparticle Synthesis

    SciTech Connect (OSTI)

    Nash, Michael A.; Lai, James J.; Hoffman, Allan S.; Yager, Paul; Stayton, Partick S.

    2010-01-13

    We report a new strategy for synthesizing temperature-responsive ?-Fe2O3-core/Au-shell nanoparticles (Au-mNPs) from diblock copolymer micelles. The amphiphilic diblock copolymer chains were synthesized using reversible addition-fragmentation chain-transfer (RAFT) with a thermally responsive “smart” poly(N-isopropylacrylamide) (pNIPAAm) block and an amine-containing poly(N,N-dimethylaminoethylacrylamide) (DMAEAm) block that acted as a reducing agent during gold shell formation. The Au-mNPs reversibly aggregated upon heating the solution above the transition temperature of pNIPAAm, resulting in a red-shifted localized surface plasmon resonance.

  20. Thermal emission of electrons under irradiation of a gold target by a femtosecond laser pulse

    SciTech Connect (OSTI)

    Bezhanov, S G; Kanavin, Andrey P; Uryupin, Sergey A

    2012-05-31

    We study the effect of d-electrons on heating of a gold target upon absorption of a femtosecond laser pulse as well as on subsequent thermal emission of hot electrons. It is shown that neglecting the effect of d-electrons leads to a significant overestimation of the number of the emitted electrons. It is found that the approximate description of the heating field in the skin layer without the inhomogeneity of the dielectric constant taken into account does not cause a significant change in the maximum temperature of the electrons at the metal surface, and has virtually no effect on the process of thermal emission.