Sample records for vacuum transmission lines

  1. Giant vacuum forces via transmission lines

    PubMed Central

    Shahmoon, Ephraim; Mazets, Igor; Kurizki, Gershon

    2014-01-01

    Quantum electromagnetic fluctuations induce forces between neutral particles, known as the van der Waals and Casimir interactions. These fundamental forces, mediated by virtual photons from the vacuum, play an important role in basic physics and chemistry and in emerging technologies involving, e.g., microelectromechanical systems or quantum information processing. Here we show that these interactions can be enhanced by many orders of magnitude upon changing the character of the mediating vacuum modes. By considering two polarizable particles in the vicinity of any standard electric transmission line, along which photons can propagate in one dimension, we find a much stronger and longer-range interaction than in free space. This enhancement may have profound implications on many-particle and bulk systems and impact the quantum technologies mentioned above. The predicted giant vacuum force is estimated to be measurable in a coplanar waveguide line. PMID:25002503

  2. Transmission line design for the lunar environment

    NASA Technical Reports Server (NTRS)

    Gaustad, Krista L.; Gordon, Lloyd B.

    1990-01-01

    How the mass, operating temperature, and efficiency of a transmission line operating on the moon are affected by its operating parameters, the lunar environment, and the choice of materials is examined. The key transmission line parameters which have an effect on mass, operating temperature, and efficiency are voltage, power loss, and waveform. The choice of waveform for transmission will be influenced by the waveform of the source and load, and therefore an analysis of both DC and AC transmission is necessary for a complete understanding of lunar power transmission. The data presented are for the DC case only; however, the discussion of the environmental effects and of material selection is pertinent to both AC and DC transmission. The operating voltage is shown to be a key parameter in transmission line design. The role efficiency plays in transmission line design is also examined. The analyses include above- and below-the-surface operation for both a vacuum-insulated, two-wire, transmission line, and a solid-dielectric-insulated, coaxial, transmission line.

  3. A study of electric transmission lines for use on the lunar surface

    NASA Technical Reports Server (NTRS)

    Gaustad, Krista L.; Gordon, Lloyd B.; Weber, Jennifer R.

    1994-01-01

    The sources for electrical power on a lunar base are said to include solar/chemical, nuclear (static conversion), and nuclear (dynamic conversion). The transmission of power via transmission lines is more practical than power beaming or superconducting because of its low cost and reliable, proven technology. Transmission lines must have minimum mass, maximum efficiency, and the ability to operate reliably in the lunar environment. The transmission line design includes conductor material, insulator material, conductor geometry, conductor configuration, line location, waveform, phase selection, and frequency. This presentation oulines the design. Liquid and gaseous dielectrics are undesirable for long term use in the lunar vacuum due to a high probability of loss. Thus, insulation for high voltage transmission line will most likely be solid dielectric or vacuum insulation.

  4. Coaxial tube array space transmission line characterization

    NASA Technical Reports Server (NTRS)

    Switzer, Colleen A.; Bents, David J.

    1987-01-01

    The coaxial tube array tether/transmission line used to connect an SP-100 nuclear power system to the space station was characterized over the range of reactor-to-platform separation distances of 1 to 10 km. Characterization was done with respect to array performance, physical dimensions and masses. Using a fixed design procedure, a family of designs was generated for the same power level (300 kWe), power loss (1.5 percent), and meteoroid survival probability (99.5 percent over 10 yr). To differentiate between vacuum insulated and gas insulated lines, two different maximum values of the E field were considered: 20 kV/cm (appropriate to vacuum insulation) and 50 kV/cm (compressed SF6). Core conductor, tube, bumper, standoff, spacer and bumper support dimensions, and masses were also calculated. The results of the characterization show mainly how transmission line size and mass scale with reactor-to-platform separation distance.

  5. Coaxial tube array space transmission line characterization

    NASA Astrophysics Data System (ADS)

    Switzer, Colleen A.; Bents, David J.

    The coaxial tube array tether/transmission line used to connect an SP-100 nuclear power system to the space station was characterized over the range of reactor-to-platform separation distances of 1 to 10 km. Characterization was done with respect to array performance, physical dimensions and masses. Using a fixed design procedure, a family of designs was generated for the same power level (300 kWe), power loss (1.5 percent), and meteoroid survival probability (99.5 percent over 10 yr). To differentiate between vacuum insulated and gas insulated lines, two different maximum values of the E field were considered: 20 kV/cm (appropriate to vacuum insulation) and 50 kV/cm (compressed SF6). Core conductor, tube, bumper, standoff, spacer and bumper support dimensions, and masses were also calculated. The results of the characterization show mainly how transmission line size and mass scale with reactor-to-platform separation distance.

  6. High-temperature superconductors for space power transmission lines

    NASA Astrophysics Data System (ADS)

    Hull, John R.; Myers, Ira T.

    1989-08-01

    Analysis of high temperature superconductors (HTS) for space power transmission lines shows that they have the potential to provide low weight alternatives to conventional power distribution systems, especially for line lengths greater than 100 m. The use of directional radiators, combined with the natural vacuum of space, offers the possibility of reducing or eliminating the heat flux from the environment that dominates loss in terrestrial systems. This leads to scaling laws that favor flat conductor geometries. From a total launch weight viewpoint, HTS transmission lines appear superior, even with presently attainable values of current density.

  7. Vacuum-jacketed transfer line installation technique

    NASA Technical Reports Server (NTRS)

    Bowers, W. M.

    1968-01-01

    Rolling-type spacers in the form of steel balls retained in appropriate sleeves affixed at intervals to the exterior of the transfer line facilitate the installation of a vacuum-jacketed line. They act as standoffs to position the transfer line concentrically within the vacuum jacket line.

  8. Transmission-line-circuit model of an 85-TW, 25-MA pulsed-power accelerator

    NASA Astrophysics Data System (ADS)

    Hutsel, B. T.; Corcoran, P. A.; Cuneo, M. E.; Gomez, M. R.; Hess, M. H.; Hinshelwood, D. D.; Jennings, C. A.; Laity, G. R.; Lamppa, D. C.; McBride, R. D.; Moore, J. K.; Myers, A.; Rose, D. V.; Slutz, S. A.; Stygar, W. A.; Waisman, E. M.; Welch, D. R.; Whitney, B. A.

    2018-03-01

    We have developed a physics-based transmission-line-circuit model of the Z pulsed-power accelerator. The 33-m-diameter Z machine generates a peak electrical power as high as 85 TW, and delivers as much as 25 MA to a physics load. The circuit model is used to design and analyze experiments conducted on Z. The model consists of 36 networks of transmission-line-circuit elements and resistors that represent each of Zs 36 modules. The model of each module includes a Marx generator, intermediate-energy-storage capacitor, laser-triggered gas switch, pulse-forming line, self-break water switches, and tri-plate transmission lines. The circuit model also includes elements that represent Zs water convolute, vacuum insulator stack, four parallel outer magnetically insulated vacuum transmission lines (MITLs), double-post-hole vacuum convolute, inner vacuum MITL, and physics load. Within the vacuum-transmission-line system the model conducts analytic calculations of current loss. To calculate the loss, the model simulates the following processes: (i) electron emission from MITL cathode surfaces wherever an electric-field threshold has been exceeded; (ii) electron loss in the MITLs before magnetic insulation has been established; (iii) flow of electrons emitted by the outer-MITL cathodes after insulation has been established; (iv) closure of MITL anode-cathode (AK) gaps due to expansion of cathode plasma; (v) energy loss to MITL conductors operated at high lineal current densities; (vi) heating of MITL-anode surfaces due to conduction current and deposition of electron kinetic energy; (vii) negative-space-charge-enhanced ion emission from MITL anode surfaces wherever an anode-surface-temperature threshold has been exceeded; and (viii) closure of MITL AK gaps due to expansion of anode plasma. The circuit model is expected to be most accurate when the fractional current loss is small. We have performed circuit simulations of 52 Z experiments conducted with a variety of accelerator

  9. Printed circuit dispersive transmission line

    DOEpatents

    Ikezi, H.; Lin-Liu, Y.R.; DeGrassie, J.S.

    1991-08-27

    A printed circuit dispersive transmission line structure is disclosed comprising an insulator, a ground plane formed on one surface of the insulator, a first transmission line formed on a second surface of the insulator, and a second transmission line also formed on the second surface of the insulator and of longer length than the first transmission line and periodically intersecting the first transmission line. In a preferred embodiment, the transmission line structure exhibits highly dispersive characteristics by designing the length of one of the transmission line between two adjacent periodic intersections to be longer than the other. 5 figures.

  10. Printed circuit dispersive transmission line

    DOEpatents

    Ikezi, Hiroyuki; Lin-Liu, Yuh-Ren; DeGrassie, John S.

    1991-01-01

    A printed circuit dispersive transmission line structure is disclosed comprising an insulator, a ground plane formed on one surface of the insulator, a first transmission line formed on a second surface of the insulator, and a second transmission line also formed on the second surface of the insulator and of longer length than the first transmission line and periodically intersecting the first transmission line. In a preferred embodiment, the transmission line structure exhibits highly dispersive characteristics by designing the length of one of the transmission line between two adjacent periodic intersections to be longer than the other.

  11. Rubber-coated bellows improves vibration damping in vacuum lines

    NASA Technical Reports Server (NTRS)

    Hegland, D. E.; Smith, R. J.

    1966-01-01

    Compact-vibration damping systems, consisting of rubber-coated metal bellows with a sliding O-ring connector, are used in vacuum lines. The device presents a metallic surface to the vacuum system and combines flexibility with the necessary stiffness. It protects against physical damage, reduces fatigue failure, and provides easy mating of nonparallel lines.

  12. Series Transmission Line Transformer

    DOEpatents

    Buckles, Robert A.; Booth, Rex; Yen, Boris T.

    2004-06-29

    A series transmission line transformer is set forth which includes two or more of impedance matched sets of at least two transmissions lines such as shielded cables, connected in parallel at one end ans series at the other in a cascading fashion. The cables are wound about a magnetic core. The series transmission line transformer (STLT) which can provide for higher impedance ratios and bandwidths, which is scalable, and which is of simpler design and construction.

  13. REQUIREMENTS AND GUIDELINES FOR NSLS EXPERIMENTAL BEAM LINE VACUUM SYSTEMS-REVISION B.

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

    FOERSTER,C.

    Typical beam lines are comprised of an assembly of vacuum valves and shutters referred to as a ''front end'', optical elements to monochromatize, focus and split the photon beam, and an experimental area where a target sample is placed into the photon beam and data from the interaction is detected and recorded. Windows are used to separate sections of beam lines that are not compatible with storage ring ultra high vacuum. Some experimental beam lines share a common vacuum with storage rings. Sections of beam lines are only allowed to vent up to atmospheric pressure using pure nitrogen gas aftermore » a vacuum barrier is established to protect ring vacuum. The front end may only be bled up when there is no current in the machine. This is especially true on the VUV storage ring where for most experiments, windows are not used. For the shorter wavelength, more energetic photons of the x-ray ring, beryllium windows are used at various beam line locations so that the monochromator, mirror box or sample chamber may be used in a helium atmosphere or rough vacuum. The window separates ring vacuum from the environment of the downstream beam line components. The stored beam lifetime in the storage rings and the maintenance of desirable reflection properties of optical surfaces depend upon hydrocarbon-free, ultra-high vacuum systems. Storage ring vacuum systems will operate at pressures of {approximately} 1 x 10{sup {minus}10} Torr without beam and {approximately} 1 x 10{sup {minus}9} Torr with beam. Systems are free of hydrocarbons in the sense that no pumps, valves, etc. containing organics are used. Components are all-metal, chemically cleaned and bakeable. To the extent that beam lines share a common vacuum with the storage ring, the same criteria will hold for beam line components. The design philosophy for NSLS beam lines is to use all-metal, hydrocarbon-free front end components and recommend that experimenters use this approach for common vacuum hardware downstream

  14. A Quantitative Transmission Line Experiment

    ERIC Educational Resources Information Center

    Johnston, D. C.; Silbernagel, B. G.

    1969-01-01

    Describes modifications of a commercially available strip-type transmission line, which makes possible reproducible measurements of standing waves on the line. Experimental data yield values for the characteristic impedance, phase velocity and line wavelength of radiation in the transmission line, and the dielectric constant of material in the…

  15. Transmission Line Security Monitor

    ScienceCinema

    None

    2017-12-09

    The Transmission Line Security Monitor is a multi-sensor monitor that mounts directly on high-voltage transmission lines to detect, characterize and communicate terrorist activity, human tampering and threatening conditions around support towers. For more information about INL's critical infrastructure protection research, visit http://www.facebook.com/idahonationallaboratory.

  16. RF Transmission Lines on Silicon Substrates

    NASA Technical Reports Server (NTRS)

    Ponchak, George E.

    1999-01-01

    A review of RF transmission lines on silicon substrates is presented. Through measurements and calculated results, it is shown that attenuation is dominated by conductor loss if silicon substrates with a resistivity greater than 2500 Ohm-cm are used. Si passivation layers affect the transmission line attenuation; however, measured results demonstrate that passivation layers do not necessarily increase attenuation. If standard, low resistivity Si wafers must be used, alternative transmission lines such as thin film microstrip and Co-Planar Waveguide (CPW) on thick polyimide layers must be used. Measured results presented here show that low loss per unit length is achievable with these transmission lines.

  17. Electrical transmission line diametrical retainer

    DOEpatents

    Hall, David R.; Hall, Jr., H. Tracy; Pixton, David; Dahlgren, Scott; Sneddon, Cameron; Briscoe, Michael; Fox, Joe

    2004-12-14

    The invention is a mechanism for retaining an electrical transmission line. In one embodiment of the invention it is a system for retaining an electrical transmission line within down hole components. In accordance with one aspect of the invention, the system includes a plurality of downhole components, such as sections of pipe in a drill string. The system also includes a coaxial cable running between the first and second end of a drill pipe, the coaxial cable having a conductive tube and a conductive core within it. The invention allows the electrical transmission line to with stand the tension and compression of drill pipe during routine drilling cycles.

  18. 49 CFR 192.179 - Transmission line valves.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Design of Pipeline Components § 192.179 Transmission line valves. (a) Each transmission line, other than offshore segments, must have sectionalizing block... 49 Transportation 3 2010-10-01 2010-10-01 false Transmission line valves. 192.179 Section 192.179...

  19. 49 CFR 192.179 - Transmission line valves.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Design of Pipeline Components § 192.179 Transmission line valves. (a) Each transmission line, other than offshore segments, must have sectionalizing block... 49 Transportation 3 2013-10-01 2013-10-01 false Transmission line valves. 192.179 Section 192.179...

  20. 49 CFR 192.179 - Transmission line valves.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Design of Pipeline Components § 192.179 Transmission line valves. (a) Each transmission line, other than offshore segments, must have sectionalizing block... 49 Transportation 3 2011-10-01 2011-10-01 false Transmission line valves. 192.179 Section 192.179...

  1. 49 CFR 192.179 - Transmission line valves.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Design of Pipeline Components § 192.179 Transmission line valves. (a) Each transmission line, other than offshore segments, must have sectionalizing block... 49 Transportation 3 2014-10-01 2014-10-01 false Transmission line valves. 192.179 Section 192.179...

  2. 49 CFR 192.179 - Transmission line valves.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Design of Pipeline Components § 192.179 Transmission line valves. (a) Each transmission line, other than offshore segments, must have sectionalizing block... 49 Transportation 3 2012-10-01 2012-10-01 false Transmission line valves. 192.179 Section 192.179...

  3. Single transmission line data acquisition system

    DOEpatents

    Fasching, George E.

    1984-01-01

    A single transmission line interrogated multiple channel data acquisition system is provided in which a plurality of remote station/sensors monitor specific process variables and transmit measurement values over the single transmission line to a master station when addressed by the master station. Power for all remote stations (up to 980) is provided by driving the line with constant voltage supplied from the master station and automatically maintained independent of the number of remote stations directly connected to the line. The transmission line can be an RG-62 coaxial cable with lengths up to about 10,000 feet with branches up to 500 feet. The remote stations can be attached randomly along the line. The remote stations can be scanned at rates up to 980 channels/second.

  4. 32 CFR 644.431 - Power transmission lines.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 4 2011-07-01 2011-07-01 false Power transmission lines. 644.431 Section 644... Power transmission lines. (a) Authority. Pursuant to the provisions of section 13(d) of the Surplus... power transmission line and the right of way acquired for its construction is needed for or adaptable to...

  5. Electrical Transmission Line Diametrical Retention Mechanism

    DOEpatents

    Hall, David R.; Hall, Jr., H. Tracy; Pixton, David; Dahlgren, Scott; Sneddon, Cameron; Briscoe, Michael; Fox, Joe

    2006-01-03

    The invention is a mechanism for retaining an electrical transmission line. In one embodiment of the invention it is a system for retaining an electrical transmission line within downhole components. The invention allows a transmission line to be attached to the internal diameter of drilling components that have a substantially uniform drilling diameter. In accordance with one aspect of the invention, the system includes a plurality of downhole components, such as sections of pipe in a drill string, drill collars, heavy weight drill pipe, and jars. The system also includes a coaxial cable running between the first and second end of a drill pipe, the coaxial cable having a conductive tube and a conductive core within it. The invention allows the electrical transmission line to withstand the tension and compression of drill pipe during routine drilling cycles.

  6. Load-resistant coaxial transmission line

    DOEpatents

    Hall, David R.; Fox, Joe

    2006-01-03

    A transmission line for downhole tools that make up all or part of a tool string for drilling and production of oil, gas, and geothermal wells that can withstand the dynamic gravitational forces and other accelerations associated with downhole excavations. The transmission line has a metal tube, or outer conductor, that houses a coaxial wire inner conductor. A non-metallic dielectric material is interposed between the inner and outer conductors. The outer and inner conductors and the dielectric are sufficiently compressed together so that independent motion between them is abated. Compression of the components of the transmission line may be achieved by drawing the transmission through one or more dies in order to draw down the outer conductor onto the dielectric, or by expanding the inner conductor against the dielectric using a mandrel or hydraulic pressure. Non-metallic bead segments may be used in aid of the compression necessary to resist the dynamic forces and accelerations of drilling.

  7. Radio frequency communication system utilizing radiating transmission lines

    DOEpatents

    Struven, Warren C.

    1984-01-01

    A radio communication system for use in tunnels, mines, buildings or other shielded locations in which a pair of radiating transmission lines (30), (31) extend through such location in spaced coextensive relation to each other. Each transmission line (30), (31) has at least one unidirectional amplifier (32), (33) interposed therein with the sense of the unidirectional amplifier (32) of one transmission line (30) being opposite to the sense of the unidirectional amplifier (33) of the other transmission line (31). Each of the amplifiers (32), (33) has a gain which is less than the coupling loss between the transmission lines (30), (31). Two or more mobile transceivers (35) in the location served by the system are coupled to the transmission lines (30), (31) by electromagnetic wave propagation in space in order to communicate directly with each other at a given radio frequency within the frequency range of the system.

  8. Rogue wave in coupled electric transmission line

    NASA Astrophysics Data System (ADS)

    Duan, J. K.; Bai, Y. L.

    2018-03-01

    Distributed electrical transmission lines that consist of a large number of identical sections have been theoretically studied in the present paper. The rogue wave is analyzed and predicted using the nonlinear Schrodinger equation (NLSE). The results indicate that, in the continuum limit, the voltage for the transmission line is described in some cases by the NLSE that is obtained using the traditional perturbation technique. The dependences of the characteristics of the rouge wave parameters on the coupled electric transmission line are shown in the paper. As is well known, rogue waves can be found for a large number of oceanic disasters, and such waves may be disastrous. However, the results of the present paper for coupled electric transmission lines may be useful.

  9. Low-noise cryogenic transmission line

    NASA Technical Reports Server (NTRS)

    Norris, D.

    1987-01-01

    New low-noise cryogenic input transmission lines have been developed for the Deep Space Network (DSN) at 1.668 GHz for cryogenically cooled Field Effect Transistors (FET) and High Electron Mobility Transistor (HEMT) amplifiers. These amplifiers exhibit very low noise temperatures of 5 K to 15 K, making the requirements for a low-noise input transmission line critical. Noise contribution to the total amplifier system from the low-noise line is less than 0.5 K for both the 1.668-GHz and 2.25-GHz FET systems. The 1.668-GHz input line was installed in six FET systems which were implemented in the DSN for the Venus Balloon Experiment. The 2.25-GHz input line has been implemented in three FET systems for the DSN 34-m HEF antennas, and the design is currently being considered for use at higher frequencies.

  10. 18 CFR 2.2 - Transmission lines.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 18 Conservation of Power and Water Resources 1 2011-04-01 2011-04-01 false Transmission lines. 2.2 Section 2.2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF... Under the Federal Power Act § 2.2 Transmission lines. In a public statement dated March 7, 1941, the...

  11. 49 CFR 192.706 - Transmission lines: Leakage surveys.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Transmission lines: Leakage surveys. 192.706... Transmission lines: Leakage surveys. Leakage surveys of a transmission line must be conducted at intervals not... transports gas in conformity with § 192.625 without an odor or odorant, leakage surveys using leak detector...

  12. 49 CFR 192.706 - Transmission lines: Leakage surveys.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Transmission lines: Leakage surveys. 192.706... Transmission lines: Leakage surveys. Leakage surveys of a transmission line must be conducted at intervals not... transports gas in conformity with § 192.625 without an odor or odorant, leakage surveys using leak detector...

  13. 49 CFR 192.706 - Transmission lines: Leakage surveys.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Transmission lines: Leakage surveys. 192.706... Transmission lines: Leakage surveys. Leakage surveys of a transmission line must be conducted at intervals not... transports gas in conformity with § 192.625 without an odor or odorant, leakage surveys using leak detector...

  14. 49 CFR 192.706 - Transmission lines: Leakage surveys.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Transmission lines: Leakage surveys. 192.706... Transmission lines: Leakage surveys. Leakage surveys of a transmission line must be conducted at intervals not... transports gas in conformity with § 192.625 without an odor or odorant, leakage surveys using leak detector...

  15. 49 CFR 192.706 - Transmission lines: Leakage surveys.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Transmission lines: Leakage surveys. 192.706... Transmission lines: Leakage surveys. Leakage surveys of a transmission line must be conducted at intervals not... transports gas in conformity with § 192.625 without an odor or odorant, leakage surveys using leak detector...

  16. Transmission geometry laserspray ionization vacuum using an atmospheric pressure inlet.

    PubMed

    Lutomski, Corinne A; El-Baba, Tarick J; Inutan, Ellen D; Manly, Cory D; Wager-Miller, James; Mackie, Ken; Trimpin, Sarah

    2014-07-01

    This represents the first report of laserspray ionization vacuum (LSIV) with operation directly from atmospheric pressure for use in mass spectrometry. Two different types of electrospray ionization source inlets were converted to LSIV sources by equipping the entrance of the atmospheric pressure inlet aperture with a customized cone that is sealed with a removable glass plate holding the matrix/analyte sample. A laser aligned in transmission geometry (at 180° relative to the inlet) ablates the matrix/analyte sample deposited on the vacuum side of the glass slide. Laser ablation from vacuum requires lower inlet temperature relative to laser ablation at atmospheric pressure. However, higher inlet temperature is required for high-mass analytes, for example, α-chymotrypsinogen (25.6 kDa). Labile compounds such as gangliosides and cardiolipins are detected in the negative ion mode directly from mouse brain tissue as intact doubly deprotonated ions. Multiple charging enhances the ion mobility spectrometry separation of ions derived from complex tissue samples.

  17. Transmission Geometry Laserspray Ionization Vacuum Using an Atmospheric Pressure Inlet

    PubMed Central

    2015-01-01

    This represents the first report of laserspray ionization vacuum (LSIV) with operation directly from atmospheric pressure for use in mass spectrometry. Two different types of electrospray ionization source inlets were converted to LSIV sources by equipping the entrance of the atmospheric pressure inlet aperture with a customized cone that is sealed with a removable glass plate holding the matrix/analyte sample. A laser aligned in transmission geometry (at 180° relative to the inlet) ablates the matrix/analyte sample deposited on the vacuum side of the glass slide. Laser ablation from vacuum requires lower inlet temperature relative to laser ablation at atmospheric pressure. However, higher inlet temperature is required for high-mass analytes, for example, α-chymotrypsinogen (25.6 kDa). Labile compounds such as gangliosides and cardiolipins are detected in the negative ion mode directly from mouse brain tissue as intact doubly deprotonated ions. Multiple charging enhances the ion mobility spectrometry separation of ions derived from complex tissue samples. PMID:24896880

  18. Coding for Single-Line Transmission

    NASA Technical Reports Server (NTRS)

    Madison, L. G.

    1983-01-01

    Digital transmission code combines data and clock signals into single waveform. MADCODE needs four standard integrated circuits in generator and converter plus five small discrete components. MADCODE allows simple coding and decoding for transmission of digital signals over single line.

  19. Drill string transmission line

    DOEpatents

    Hall, David R.; Hall, Jr., H. Tracy; Pixton, David S.; Bradford, Kline; Fox, Joe

    2006-03-28

    A transmission line assembly for transmitting information along a downhole tool comprising a pin end, a box end, and a central bore traveling between the pin end and the box end, is disclosed in one embodiment of the invention as including a protective conduit. A transmission line is routed through the protective conduit. The protective conduit is routed through the central bore and the ends of the protective conduit are routed through channels formed in the pin end and box end of the downhole tool. The protective conduit is elastically forced into a spiral or other non-linear path along the interior surface of the central bore by compressing the protective conduit to a length within the downhole tool shorter than the protective conduit.

  20. Method for bonding a transmission line to a downhole tool

    DOEpatents

    Hall, David R.; Fox, Joe

    2007-11-06

    An apparatus for bonding a transmission line to the central bore of a downhole tool includes a pre-formed interface for bonding a transmission line to the inside diameter of a downhole tool. The pre-formed interface includes a first surface that substantially conforms to the outside contour of a transmission line and a second surface that substantially conforms to the inside diameter of a downhole tool. In another aspect of the invention, a method for bonding a transmission line to the inside diameter of a downhole tool includes positioning a transmission line near the inside wall of a downhole tool and placing a mold near the transmission line and the inside wall. The method further includes injecting a bonding material into the mold and curing the bonding material such that the bonding material bonds the transmission line to the inside wall.

  1. 49 CFR 192.719 - Transmission lines: Testing of repairs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... pipe before it is installed. (b) Testing of repairs made by welding. Each repair made by welding in... 49 Transportation 3 2010-10-01 2010-10-01 false Transmission lines: Testing of repairs. 192.719... Transmission lines: Testing of repairs. (a) Testing of replacement pipe. If a segment of transmission line is...

  2. Coiled transmission line pulse generators

    DOEpatents

    McDonald, Kenneth Fox

    2010-11-09

    Methods and apparatus are provided for fabricating and constructing solid dielectric "Coiled Transmission Line" pulse generators in radial or axial coiled geometries. The pour and cure fabrication process enables a wide variety of geometries and form factors. The volume between the conductors is filled with liquid blends of monomers, polymers, oligomers, and/or cross-linkers and dielectric powders; and then cured to form high field strength and high dielectric constant solid dielectric transmission lines that intrinsically produce ideal rectangular high voltage pulses when charged and switched into matched impedance loads. Voltage levels may be increased by Marx and/or Blumlein principles incorporating spark gap or, preferentially, solid state switches (such as optically triggered thyristors) which produce reliable, high repetition rate operation. Moreover, these Marxed pulse generators can be DC charged and do not require additional pulse forming circuitry, pulse forming lines, transformers, or an a high voltage spark gap output switch. The apparatus accommodates a wide range of voltages, impedances, pulse durations, pulse repetition rates, and duty cycles. The resulting mobile or flight platform friendly cylindrical geometric configuration is much more compact, light-weight, and robust than conventional linear geometries, or pulse generators constructed from conventional components. Installing additional circuitry may accommodate optional pulse shape improvements. The Coiled Transmission Lines can also be connected in parallel to decrease the impedance, or in series to increase the pulse length.

  3. Wind adaptive modeling of transmission lines using minimum description length

    NASA Astrophysics Data System (ADS)

    Jaw, Yoonseok; Sohn, Gunho

    2017-03-01

    The transmission lines are moving objects, which positions are dynamically affected by wind-induced conductor motion while they are acquired by airborne laser scanners. This wind effect results in a noisy distribution of laser points, which often hinders accurate representation of transmission lines and thus, leads to various types of modeling errors. This paper presents a new method for complete 3D transmission line model reconstruction in the framework of inner and across span analysis. The highlighted fact is that the proposed method is capable of indirectly estimating noise scales, which corrupts the quality of laser observations affected by different wind speeds through a linear regression analysis. In the inner span analysis, individual transmission line models of each span are evaluated based on the Minimum Description Length theory and erroneous transmission line segments are subsequently replaced by precise transmission line models with wind-adaptive noise scale estimated. In the subsequent step of across span analysis, detecting the precise start and end positions of the transmission line models, known as the Point of Attachment, is the key issue for correcting partial modeling errors, as well as refining transmission line models. Finally, the geometric and topological completion of transmission line models are achieved over the entire network. A performance evaluation was conducted over 138.5 km long corridor data. In a modest wind condition, the results demonstrates that the proposed method can improve the accuracy of non-wind-adaptive initial models on an average of 48% success rate to produce complete transmission line models in the range between 85% and 99.5% with the positional accuracy of 9.55 cm transmission line models and 28 cm Point of Attachment in the root-mean-square error.

  4. Multiturn split-conductor transmission-line resonator

    NASA Astrophysics Data System (ADS)

    Haziza, Nathalie; Bittoun, Jacques; Kan, Siew

    1997-05-01

    A split-conductor parallel-plate transmission line resonator is a simple structure made from bending a strip of double-face copper-clad printed-circuit board into a loop with alternate electrical discontinuities (gaps) on opposite sides. Its natural resonant frequency (Fn) is determined by the transmission line characteristic impedance, the loop diameter or strip length, and the number (Ng) of gaps. It is easy to design high frequency resonators simply by increasing Ng. We propose here a single-gap multiturn resonator for low frequency operation as well as a simplified expression for the determination of Fn. A design procedure of this type of resonator is outlined and illustrative examples with parallel-plate as well as ordinary 50 Ω coaxial transmission lines are given. Also, for a given cable length, numerical calculation shows that the minimum resonator frequency can be attained with a form factor of the order of 2.

  5. On the dispersion characteristics of metamaterial transmission lines

    NASA Astrophysics Data System (ADS)

    Sisó, G.; Gil, M.; Bonache, J.; Martín, F.

    2007-10-01

    In this paper, a detailed analysis of the dispersion characteristics of metamaterial transmission lines, based on the lumped element T-circuit model is carried out. One of the main relevant characteristics of these artificial lines is the possibility to tailor the phase response. This leads to unique properties which are of interest for microwave circuit design, such as bandwidth enhancement or multiband (dual-band) operation, among others. However, it is shown in this paper that, in spite of the larger number of circuit parameters (as compared to conventional lines), there exist intrinsic limitations that may limit the performance of such metamaterial transmission lines under certain conditions. In this paper these limitations are pointed out from an accurate analysis of the phase response and the Foster's reactance theorem [Bell Syst. Tech. 3, 259 (1924)]. From the results of this paper, important guidelines for the design of microwave components based on metamaterial transmission lines are inferred. The fabrication and characterization of different metamaterial transmission lines will corroborate the theoretical results.

  6. Silicon photonics plasma-modulators with advanced transmission line design.

    PubMed

    Merget, Florian; Azadeh, Saeed Sharif; Mueller, Juliana; Shen, Bin; Nezhad, Maziar P; Hauck, Johannes; Witzens, Jeremy

    2013-08-26

    We have investigated two novel concepts for the design of transmission lines in travelling wave Mach-Zehnder interferometer based Silicon Photonics depletion modulators overcoming the analog bandwidth limitations arising from cross-talk between signal lines in push-pull modulators and reducing the linear losses of the transmission lines. We experimentally validate the concepts and demonstrate an E/O -3 dBe bandwidth of 16 GHz with a 4V drive voltage (in dual drive configuration) and 8.8 dB on-chip insertion losses. Significant bandwidth improvements result from suppression of cross-talk. An additional bandwidth enhancement of ~11% results from a reduction of resistive transmission line losses. Frequency dependent loss models for loaded transmission lines and E/O bandwidth modeling are fully verified.

  7. Investigation of a stripline transmission line structure for gyromagnetic nonlinear transmission line high power microwave sources.

    PubMed

    Reale, D V; Parson, J M; Neuber, A A; Dickens, J C; Mankowski, J J

    2016-03-01

    A stripline gyromagnetic nonlinear transmission line (NLTL) was constructed out of yttrium iron garnet ferrite and tested at charge voltages of 35 kV-55 kV with bias fields ranging from 10 kA/m to 20 kA/m. Typically, high power gyromagnetic NLTLs are constructed in a coaxial geometry. While this approach has many advantages, including a uniform transverse electromagnetic (TEM) mode, simple interconnection between components, and the ability to use oil or pressurized gas as an insulator, the coaxial implementation suffers from complexity of construction, especially when using a solid insulator. By moving to a simpler transmission line geometry, NLTLs can be constructed more easily and arrayed on a single substrate. This work represents a first step in exploring the suitability of various transmission line structures, such as microstrips and coplanar waveguides. The resulting high power microwave (HPM) source operates in ultra high frequency (UHF) band with an average bandwidth of 40.1% and peak rf power from 2 MW to 12.7 MW.

  8. Investigation of a stripline transmission line structure for gyromagnetic nonlinear transmission line high power microwave sources

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

    Reale, D. V., E-mail: david.reale@ttu.edu; Parson, J. M.; Neuber, A. A.

    2016-03-15

    A stripline gyromagnetic nonlinear transmission line (NLTL) was constructed out of yttrium iron garnet ferrite and tested at charge voltages of 35 kV–55 kV with bias fields ranging from 10 kA/m to 20 kA/m. Typically, high power gyromagnetic NLTLs are constructed in a coaxial geometry. While this approach has many advantages, including a uniform transverse electromagnetic (TEM) mode, simple interconnection between components, and the ability to use oil or pressurized gas as an insulator, the coaxial implementation suffers from complexity of construction, especially when using a solid insulator. By moving to a simpler transmission line geometry, NLTLs can be constructedmore » more easily and arrayed on a single substrate. This work represents a first step in exploring the suitability of various transmission line structures, such as microstrips and coplanar waveguides. The resulting high power microwave (HPM) source operates in ultra high frequency (UHF) band with an average bandwidth of 40.1% and peak rf power from 2 MW to 12.7 MW.« less

  9. Active microwave negative-index metamaterial transmission line with gain.

    PubMed

    Jiang, Tao; Chang, Kihun; Si, Li-Ming; Ran, Lixin; Xin, Hao

    2011-11-11

    We studied the active metamaterial transmission line at microwave frequency. The active composite right-handed or left-handed transmission line was designed to incorporate a germanium tunnel diode with a negative differential resistance property as the gain device at the unit cell level. Measurements of the fabricated planar transmission line structures with one-, two-, and three-unit cells showed that the addition of the dc pumped tunnel diodes not only provided gain but also maintained the left handedness of the transmission line metamaterial. Simulation results agree well with experimental observation. This work demonstrated that negative index material can be obtained with a net gain when an external source is incorporated.

  10. Vacuum-induced Autler-Townes splitting in a superconducting artificial atom

    NASA Astrophysics Data System (ADS)

    Peng, Z. H.; Ding, J. H.; Zhou, Y.; Ying, L. L.; Wang, Z.; Zhou, L.; Kuang, L. M.; Liu, Yu-xi; Astafiev, O. V.; Tsai, J. S.

    2018-06-01

    We experimentally study a vacuum-induced Autler-Townes doublet in a superconducting three-level artificial atom strongly coupled to a coplanar waveguide resonator and simultaneously to a transmission line. The Autler-Townes splitting is observed in the reflection spectrum from the three-level atom in a transition between the ground state and the second excited state when the transition between the two excited states is resonant with a resonator. By applying a driving field to the resonator, we observe a change in the regime of the Autler-Townes splitting from quantum (vacuum-induced) to classical (with many resonator photons). Furthermore, we show that the reflection of propagating microwaves in a transmission line could be controlled by different frequency microwave fields at the single-photon level in a resonator.

  11. Transportation properties of a high-current magnetically insulated transmission line and dynamics of the electrode plasma

    NASA Astrophysics Data System (ADS)

    Anan'ev, S. S.; Bakshaev, Yu. L.; Bartov, A. V.; Blinov, P. I.; Dan'ko, S. A.; Zhuzhunashvili, A. I.; Kazakov, E. D.; Kalinin, Yu. G.; Kingsep, A. S.; Korolev, V. D.; Mizhiritskii, V. I.; Smirnov, V. P.; Tkachenko, S. I.; Chernenko, A. S.

    2008-07-01

    Results are presented from experimental studies of a section of a magnetically insulated transmission line (MITL) with a current density of up to 500 MA/cm2 and linear current density of up to 7 MA/cm (the parameters close to those in a fast-Z-pinch-driven fusion reactor projected at Sandia Laboratories). The experiments were performed in the S-300 facility (3 MA, 0.15 Ω, 100 ns). At high linear current densities, the surface of the ohmically heated MITL electrode can explode and a plasma layer can form near the electrode surface. As a result, the MITL can lose its transmission properties due to the shunting of the vacuum gap by the plasma produced. In this series of experiments, the dynamics of the electrode plasma and the dependence of the transmission properties of the MITL on the material and cleanness of the electrode surface were studied. It is shown experimentally that, when the current with a linear density of up to 7 MA/cm begins to flow along a model MITL, the input and output currents differ by less than 10% over a time interval of up to 230 ns for nickel electrodes and up to 350 ns for a line with a gold central electrode. No effect of the oil film present on the electrode surface on the loss of the transmission properties of the line was observed. It is also shown that electron losses insignificantly contribute to the total current balance. The experimental results are compared with calculations of the electrode explosion and the subsequent expansion of the plasma layer. A conclusion is made that the life-time of the model MITL satisfies the requirements imposed on the transmission lines intended for use in the projected thermonuclear reactor.

  12. Voltage gain optimization of transmission line transformers

    NASA Astrophysics Data System (ADS)

    Pécastaing, L.; Reess, T.; Paillol, J.; Gibert, A.; Domens, P.

    2003-06-01

    Transmission Line Transformers (TLT) based on the use of ferrite beads are presented. This work aims at optimising the performance of the voltage gain and the compactness of the TLT according to the position, the type and the number of ferrites used. The ferrites have been selected taking into account two main parameters: the maximum currents flowing through the outer conductor of the lines of a TLT without ferrite beads and the current frequencies. The function of these ferrites is to decrease the effect of parasitic short-circuit transmission lines between the outer conductors of the coaxial cables of the TLT. Voltages and secondary currents are measured on each cable. The voltage gain achieved reaches the optimum theoretical value thanks to the use of ferrites for a 2, 4 and 10-stage transmission line transformer. Each cable is shorter than 1.5 meter in length which provides an unquestionable advantage of compactness.

  13. 49 CFR 192.485 - Remedial measures: Transmission lines.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Requirements for Corrosion Control § 192.485 Remedial measures: Transmission lines. (a) General corrosion. Each segment of transmission line with general corrosion and with a remaining wall thickness less than that required for the...

  14. 49 CFR 192.485 - Remedial measures: Transmission lines.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Requirements for Corrosion Control § 192.485 Remedial measures: Transmission lines. (a) General corrosion. Each segment of transmission line with general corrosion and with a remaining wall thickness less than that required for the...

  15. 49 CFR 192.485 - Remedial measures: Transmission lines.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Requirements for Corrosion Control § 192.485 Remedial measures: Transmission lines. (a) General corrosion. Each segment of transmission line with general corrosion and with a remaining wall thickness less than that required for the...

  16. 49 CFR 192.485 - Remedial measures: Transmission lines.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Requirements for Corrosion Control § 192.485 Remedial measures: Transmission lines. (a) General corrosion. Each segment of transmission line with general corrosion and with a remaining wall thickness less than that required for the...

  17. KAHVE Laboratory RF circulator and transmission line project

    NASA Astrophysics Data System (ADS)

    Cetinkaya, Hakan; ćaǧlar, Aslıhan; ćiçek, Cihan; Özbey, Aydın; Sunar, Ezgi; Türemen, Görkem; Yıldız, Hüseyin; Yüncü, Alperen; Özcan, Erkcan; Ünel, Gökhan; Yaman, Fatih

    2018-02-01

    An 800 MHz RF circulator and transmission line project has recently started at the newly commissioned Kandilli Detector, Accelerator and Instrumentation (KAHVE) Laboratory at the Boğaziçi University. The aims are to design, build and construct an RF circulator and transmission line in Turkey for high power and high frequency applications. The project consists of 8 transmission line elements: 800 MHz RF generator with 60 kW power (klystron), klystron to waveguide converter, waveguides, E and H bends, 3-port circulator and waveguide to coaxial converter to transmit RF power to a pillbox RF cavity. Design studies and details of the ongoing project will be presented.

  18. Research on cost control and management in high voltage transmission line construction

    NASA Astrophysics Data System (ADS)

    Xu, Xiaobin

    2017-05-01

    Enterprises. The cost control is of vital importance to the construction enterprises. It is the key to the profitability of the transmission line project, which is related to the survival and development of the electric power construction enterprises. Due to the long construction line, complex and changeable construction terrain as well as large construction costs of transmission line, it is difficult for us to take accurate and effective cost control on the project implementation of entire transmission line. Therefore, the cost control of transmission line project is a complicated and arduous task. It is of great theoretical and practical significance to study the cost control scheme of transmission line project by a more scientific and efficient way. Based on the characteristics of the construction project of the transmission line project, this paper analyzes the construction cost structure of the transmission line project and the current cost control problem of the transmission line project, and demonstrates the necessity and feasibility of studying the cost control scheme of the transmission line project more accurately. In this way, the dynamic cycle cost control process including plan, implementation, feedback, correction, modification and re-implement is achieved to realize the accurate and effective cost control of entire electric power transmission line project.

  19. Self-Shielding Of Transmission Lines

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

    Christodoulou, Christos

    The use of shielding to contend with noise or harmful EMI/EMR energy is not a new concept. An inevitable trade that must be made for shielding is physical space and weight. Space was often not as much of a painful design trade in older larger systems as they are in today’s smaller systems. Today we are packing in an exponentially growing number of functionality within the same or smaller volumes. As systems become smaller and space within systems become more restricted, the implementation of shielding becomes more problematic. Often, space that was used to design a more mechanically robust componentmore » must be used for shielding. As the system gets smaller and space is at more of a premium, the trades starts to result in defects, designs with inadequate margin in other performance areas, and designs that are sensitive to manufacturing variability. With these challenges in mind, it would be ideal to maximize attenuation of harmful fields as they inevitably couple onto transmission lines without the use of traditional shielding. Dr. Tom Van Doren proposed a design concept for transmission lines to a class of engineers while visiting New Mexico. This design concept works by maximizing Electric field (E) and Magnetic Field (H) field containment between operating transmission lines to achieve what he called “Self-Shielding”. By making the geometric centroid of the outgoing current coincident with the return current, maximum field containment is achieved. The reciprocal should be true as well, resulting in greater attenuation of incident fields. Figure’s 1(a)-1(b) are examples of designs where the current centroids are coincident. Coax cables are good examples of transmission lines with co-located centroids but they demonstrate excellent field attenuation for other reasons and can’t be used to test this design concept. Figure 1(b) is a flex circuit design that demonstrate the implementation of self-shielding vs a standard conductor layout.« less

  20. Effect of tornado loads on transmission lines

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

    Ishac, M.F.; White, H.B.

    Of all the populated areas in Canada, southwestern Ontario has experienced the highest tornado incidence and faces the greatest tornado damage. About 1 or 2 tornadoes per 10,000 km{sup 2} can be expected there annually. The probability of a tornado strike at a given point is very small but the probability of a transmission line being crossed by a tornado is significant. The purpose of this paper is to review the literature related to tornadoes in Ontario and to investigate the effect of tornado loads on transmission lines. Based on this investigation a design basis tornado loading for transmission towersmore » is proposed.« less

  1. Effect of tornado loads on transmission lines

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

    Ishac, M.F.; White, H.B.

    1994-12-31

    Of all the populated areas in Canada, southwestern Ontario has experienced the highest tornado incidence and faces the greatest tornado damage. About 1 or 2 tornadoes per 10,000 km{sup 2} can be expected there annually. The probability of a tornado strike at a given point is very small but the probability of a transmission line being crossed by a tornado is significant. The purpose of this paper is to review the literature related to tornadoes in Ontario and to investigate the effect of tornado loads on transmission lines. Based on this investigation a design basis tornado loading for transmission towersmore » is proposed.« less

  2. Pulse shaping with transmission lines

    DOEpatents

    Wilcox, Russell B.

    1987-01-01

    A method and apparatus for forming shaped voltage pulses uses passive reflection from a transmission line with nonuniform impedance. The impedance of the reflecting line varies with length in accordance with the desired pulse shape. A high voltage input pulse is transmitted to the reflecting line. A reflected pulse is produced having the desired shape and is transmitted by pulse removal means to a load. Light activated photoconductive switches made of silicon can be utilized. The pulse shaper can be used to drive a Pockels cell to produce shaped optical pulses.

  3. Pulse shaping with transmission lines

    DOEpatents

    Wilcox, R.B.

    1985-08-15

    A method and apparatus for forming shaped voltage pulses uses passive reflection from a transmission line with nonuniform impedance. The impedance of the reflecting line varies with length in accordance with the desired pulse shape. A high voltage input pulse is transmitted to the reflecting line. A reflected pulse is produced having the desired shape and is transmitted by pulse removal means to a load. Light activated photoconductive switches made of silicon can be utilized. The pulse shaper can be used to drive a Pockels cell to produce shaped optical pulses.

  4. Corrugated outer sheath gas-insulated transmission line

    DOEpatents

    Kemeny, George A.; Cookson, Alan H.

    1981-01-01

    A gas-insulated transmission line includes two transmission line sections each of which are formed of a corrugated outer housing enclosing an inner high-voltage conductor disposed therein, with insulating support means supporting the inner conductor within the outer housing and an insulating gas providing electrical insulation therebetween. The outer housings in each section have smooth end sections at the longitudinal ends thereof which are joined together by joining means which provide for a sealing fixed joint.

  5. Computational analysis of current-loss mechanisms in a post-hole convolute driven by magnetically insulated transmission lines

    DOE PAGES

    Rose, D.  V.; Madrid, E.  A.; Welch, D.  R.; ...

    2015-03-04

    Numerical simulations of a vacuum post-hole convolute driven by magnetically insulated vacuum transmission lines (MITLs) are used to study current losses due to charged particle emission from the MITL-convolute-system electrodes. This work builds on the results of a previous study [E.A. Madrid et al. Phys. Rev. ST Accel. Beams 16, 120401 (2013)] and adds realistic power pulses, Ohmic heating of anode surfaces, and a model for the formation and evolution of cathode plasmas. The simulations suggest that modestly larger anode-cathode gaps in the MITLs upstream of the convolute result in significantly less current loss. In addition, longer pulse durations leadmore » to somewhat greater current loss due to cathode-plasma expansion. These results can be applied to the design of future MITL-convolute systems for high-current pulsed-power systems.« less

  6. Airplane Ice Detector Based on a Microwave Transmission Line

    NASA Technical Reports Server (NTRS)

    Ngo, Phong; Arndt, G. Dickey; Carl, James R.

    2004-01-01

    An electronic instrument that could detect the potentially dangerous buildup of ice on an airplane wing is undergoing development. The instrument is based on a microwave transmission line configured as a capacitance probe: at selected spots, the transmission-line conductors are partly exposed to allow any ice and/or liquid water present at those spots to act as predominantly capacitive electrical loads on the transmission line. These loads change the input impedance of the transmission line, as measured at a suitable excitation frequency. Thus, it should be possible to infer the presence of ice and/or liquid water from measurements of the input impedance and/or electrical parameters related to the input impedance. The sensory transmission line is of the microstrip type and thus thin enough to be placed on an airplane wing without unduly disturbing airflow in flight. The sensory spots are small areas from which the upper layer of the microstrip has been removed to allow any liquid water or ice on the surface to reach the transmission line. The sensory spots are spaced at nominal open-circuit points, which are at intervals of a half wavelength (in the transmission line, not in air) at the excitation frequency. The excitation frequency used in the experiments has been 1 GHz, for which a half wavelength in the transmission line is .4 in. (.10 cm). The figure depicts a laboratory prototype of the instrument. The impedance-related quantities chosen for use in this version of the instrument are the magnitude and phase of the scattering parameter S11 as manifested in the in-phase (I ) and quadrature (Q) outputs of the phase detector. By careful layout of the transmission line (including the half-wavelength sensor spacing), one can ensure that the amplitude and phase of the input to the phase detector keep shifting in the same direction as ice forms on one or more of the sensor areas. Although only one transmission-line sensor strip is used in the laboratory version, in a

  7. Research on the Test of Transmission Line Galloping

    NASA Astrophysics Data System (ADS)

    Zhang, Lichun; Li, Qing; lv, Zhongbin; Ji, Kunpeng; Liu, Bin

    2018-03-01

    The load of iced transmission line and the load generated by galloping after the conductor are covered by ice all may cause severe circuit faults, such as tripping, conductor breaking, armor clamp damage and even tower collapse, thus severely threatening running safety of power system. The generation and development processes of galloping of power transmission line is very complicated, and numerous factors may influence the galloping excitation, such as environmental factors, terrain factors and structural parameters of power transmission line; in which, the ice covering of conductor is one of necessary factors causing galloping. Therefore, researches on ice covering increasing test of different types of conductors under different meteorological conditions have been conducted in large-sized multi-functional phytotron, thus obtaining the relation curve of ice covering increasing of conductor along with time under different conditions, and analyzing factors influencing increasing of ice covering. The research result shows that under the same ice covering conditions, the increasing of ice covering of conductor with small diameter is relatively rapid; both environmental temperature and wind speed have obvious influence on increasing of ice covering of conductor, and the environmental temperature will decide the type of ice covering of conductor surface. Meanwhile, after wind tunnel tests targeting conductors with different ice covering shapes, pneumatic stability loss characteristics of conductors with different ice shapes have been obtained. Research results have important scientific reference value for revealing the mechanism of galloping of iced power transmission line, and have relatively high engineering practicability value for promoting realization of early warning system for galloping of iced power transmission line.

  8. Smaller-loss planar SPP transmission line than conventional microstrip in microwave frequencies.

    PubMed

    Zhang, Hao Chi; Zhang, Qian; Liu, Jun Feng; Tang, Wenxuan; Fan, Yifeng; Cui, Tie Jun

    2016-03-17

    Transmission line is a basic component in all passive devices, integrated circuits, and systems. Microstrip is the most popular transmission line in the microwave and millimeter-wave frequencies, and has been widely used in current electronic devices, circuits, and systems. One of the important issues to be solved in such applications is the relatively large transmission loss of microstrip. Here, we propose a method to reduce the loss of microwave transmission line based on the designable wavenumber of spoof surface plasmon polaritons (SPPs). Using this characteristic, we analyze and experimentally demonstrate the low-loss feature of the SPP transmission line through the perturbation method and S-parameter measurements, respectively. Both simulation and experimental results show that the SPP transmission line has much smaller transmission loss than traditional microstrip with the same size in the microwave frequencies. Hence, the spoof SPP transmission line may make a big step forward in the low-loss circuits and systems.

  9. Flux Cloning in Josephson Transmission Lines

    NASA Astrophysics Data System (ADS)

    Gulevich, D. R.; Kusmartsev, F. V.

    2006-07-01

    We describe a novel effect related to the controlled birth of a single Josephson vortex. In this phenomenon, the vortex is created in a Josephson transmission line at a T-shaped junction. The “baby” vortex arises at the moment when a “mother” vortex propagating in the adjacent transmission line passes the T-shaped junction. In order to give birth to a new vortex, the mother vortex must have enough kinetic energy. Its motion can also be supported by an externally applied driving current. We determine the critical velocity and the critical driving current for the creation of the baby vortices and briefly discuss the potential applications of the found effect.

  10. Electrical and Biological Effects of Transmission Lines: A Review.

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

    Lee, Jack M.

    1989-06-01

    This review describes the electrical properties of a-c and d-c transmission lines and the resulting effects on plants, animals, and people. Methods used by BPA to mitigate undesirable effects are also discussed. Although much of the information in this review pertains to high-voltage transmission lines, information on distribution lines and electrical appliances is included. The electrical properties discussed are electric and magnetic fields and corona: first for alternating-current (a-c) lines, then for direct current (d-c).

  11. 49 CFR 192.715 - Transmission lines: Permanent field repair of welds.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Transmission lines: Permanent field repair of... § 192.715 Transmission lines: Permanent field repair of welds. Each weld that is unacceptable under § 192.241(c) must be repaired as follows: (a) If it is feasible to take the segment of transmission line...

  12. 49 CFR 192.715 - Transmission lines: Permanent field repair of welds.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Transmission lines: Permanent field repair of... § 192.715 Transmission lines: Permanent field repair of welds. Each weld that is unacceptable under § 192.241(c) must be repaired as follows: (a) If it is feasible to take the segment of transmission line...

  13. 49 CFR 192.715 - Transmission lines: Permanent field repair of welds.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Transmission lines: Permanent field repair of... § 192.715 Transmission lines: Permanent field repair of welds. Each weld that is unacceptable under § 192.241(c) must be repaired as follows: (a) If it is feasible to take the segment of transmission line...

  14. 49 CFR 192.715 - Transmission lines: Permanent field repair of welds.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Transmission lines: Permanent field repair of... § 192.715 Transmission lines: Permanent field repair of welds. Each weld that is unacceptable under § 192.241(c) must be repaired as follows: (a) If it is feasible to take the segment of transmission line...

  15. 49 CFR 192.715 - Transmission lines: Permanent field repair of welds.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Transmission lines: Permanent field repair of... § 192.715 Transmission lines: Permanent field repair of welds. Each weld that is unacceptable under § 192.241(c) must be repaired as follows: (a) If it is feasible to take the segment of transmission line...

  16. Single transmission line interrogated multiple channel data acquisition system

    DOEpatents

    Fasching, George E.; Keech, Jr., Thomas W.

    1980-01-01

    A single transmission line interrogated multiple channel data acquisition system is provided in which a plurality of remote station/sensor circuits each monitors a specific process variable and each transmits measurement values over a single transmission line to a master interrogating station when addressed by said master interrogating station. Typically, as many as 330 remote stations may be parallel connected to the transmission line which may exceed 7,000 feet. The interrogation rate is typically 330 stations/second. The master interrogating station samples each station according to a shared, charging transmit-receive cycle. All remote station address signals, all data signals from the remote stations/sensors and all power for all of the remote station/sensors are transmitted via a single continuous terminated coaxial cable. A means is provided for periodically and remotely calibrating all remote sensors for zero and span. A provision is available to remotely disconnect any selected sensor station from the main transmission line.

  17. 3. DETAIL, LIGHTNING ARRESTER ON SAR TRANSMISSION LINE. EEC print ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. DETAIL, LIGHTNING ARRESTER ON SAR TRANSMISSION LINE. EEC print no. S-C-01-00478, no date. Photographer unknown. - Santa Ana River Hydroelectric System, Transmission Lines, Redlands, San Bernardino County, CA

  18. An Insight on Right of Way and its Cost for Power Transmission Cable and Conventional Overhead Transmission Lines

    NASA Astrophysics Data System (ADS)

    Khandelwal, P.; Pachori, A.; Khandelwal, T.

    2013-12-01

    This paper provides the complete information related to Right of Way (RoW) for the construction of new power transmission line (TL) in terms of present cost for overhead transmission line and underground XLPE transmission cable. The former part of the paper describes the general procedure and rules for acquisition of land for RoW by transmission asset owner (TAO) while in the later part the cost associated to acquire RoW and its impact on the cost of adjacent land have been detailed. It also discusses the actual dismantling cost including the cost of waste metal what TAO get after completion of lifecycle of TL due to increase in metal prices. In this paper cost of RoW after completion of lifecycle of TL is also highlighted. This paper compares the cost of RoW for overhead transmission line and underground XLPE transmission cable for construction of new TL. Also for old transmission infrastructure cost of RoW for change from overhead transmission line to underground XLPE transmission cable is detailed by application of replacement model.

  19. VACUUM TRAP AND VALVE COMBINATION

    DOEpatents

    Milleron, N.; Levenson, L.

    1963-02-19

    This patent relates to a vacuum trap and valve combination suitable for use in large ultra-high vacuum systems. The vacuum trap is a chamber having an inlet and outlet opening which may be made to communicate with a chamber to be evacuated and a diffusion pump, respectively. A valve is designed to hermeticaliy seal with inlet opening and, when opened, block the line-of- sight'' between the inlet and outlet openings, while allowing a large flow path between the opened vaive and the side walls of the trap. The interior of the trap and the side of the valve facing the inlet opening are covered with an impurity absorbent, such as Zeolite or activated aluminum. Besides the advantage of combining two components of a vacuum system into one, the present invention removes the need for a baffle between the pump and the chamber to be evacuated. In one use of a specific embodiment of this invention, the transmission probability was 45 and the partial pressure of the pump fluid vapor in the vacuum chamber was at least 100 times lower than its vapor pressure. (AEC)

  20. Development of the ITER ICH Transmission Line and Matching System

    NASA Astrophysics Data System (ADS)

    Rasmussen, D. A.; Goulding, R. H.; Pesavento, P. V.; Peters, B.; Swain, D. W.; Fredd, E. H.; Hosea, J.; Greenough, N.

    2011-10-01

    The ITER Ion Cyclotron Heating (ICH) System is designed to couple 20 MW of heating power for ion and electron heating. Prototype components for the ITER Ion Cyclotron Heating (ICH) transmission line and matching system are being designed and tested. The ICH transmission lines are pressurized 300 mm diameter coaxial lines with water-cooled aluminum outer conductor and gas-cooled and water-cooled copper inner conductor. Each ICH transmission line is designed to handle 40-55 MHz power at up to 6 MW/line. A total of 8 lines split to 16 antenna inputs on two ICH antennas. Industrial suppliers have designed coaxial transmission line and matching components and prototypes will be manufactured. The prototype components will be qualified on a test stand operating at the full power and pulse length needed for ITER. The matching system must accommodated dynamic changes in the plasma loading due to ELMS and the L to H-mode transition. Passive ELM tolerance will be performed using hybrid couplers and loads, which can absorb the transient reflected power. The system is also designed to compensate for the mutual inductances of the antenna current straps to limit the peak voltages on the antenna array elements.

  1. 49 CFR 236.73 - Open-wire transmission line; clearance to other circuits.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Open-wire transmission line; clearance to other..., AND APPLIANCES Rules and Instructions: All Systems Wires and Cables § 236.73 Open-wire transmission line; clearance to other circuits. Open-wire transmission line operating at voltage of 750 volts or...

  2. 49 CFR 236.73 - Open-wire transmission line; clearance to other circuits.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Open-wire transmission line; clearance to other..., AND APPLIANCES Rules and Instructions: All Systems Wires and Cables § 236.73 Open-wire transmission line; clearance to other circuits. Open-wire transmission line operating at voltage of 750 volts or...

  3. Wireless Integrated Microelectronic Vacuum Sensor System

    NASA Technical Reports Server (NTRS)

    Krug, Eric; Philpot, Brian; Trott, Aaron; Lawrence, Shaun

    2013-01-01

    NASA Stennis Space Center's (SSC's) large rocket engine test facility requires the use of liquid propellants, including the use of cryogenic fluids like liquid hydrogen as fuel, and liquid oxygen as an oxidizer (gases which have been liquefied at very low temperatures). These fluids require special handling, storage, and transfer technology. The biggest problem associated with transferring cryogenic liquids is product loss due to heat transfer. Vacuum jacketed piping is specifically designed to maintain high thermal efficiency so that cryogenic liquids can be transferred with minimal heat transfer. A vacuum jacketed pipe is essentially two pipes in one. There is an inner carrier pipe, in which the cryogenic liquid is actually transferred, and an outer jacket pipe that supports and seals the vacuum insulation, forming the "vacuum jacket." The integrity of the vacuum jacketed transmission lines that transfer the cryogenic fluid from delivery barges to the test stand must be maintained prior to and during engine testing. To monitor the vacuum in these vacuum jacketed transmission lines, vacuum gauge readings are used. At SSC, vacuum gauge measurements are done on a manual rotation basis with two technicians, each using a handheld instrument. Manual collection of vacuum data is labor intensive and uses valuable personnel time. Additionally, there are times when personnel cannot collect the data in a timely fashion (i.e., when a leak is detected, measurements must be taken more often). Additionally, distribution of this data to all interested parties can be cumbersome. To simplify the vacuum-gauge data collection process, automate the data collection, and decrease the labor costs associated with acquiring these measurements, an automated system that monitors the existing gauges was developed by Invocon, Inc. For this project, Invocon developed a Wireless Integrated Microelectronic Vacuum Sensor System (WIMVSS) that provides the ability to gather vacuum

  4. Reconfigurable Wave Velocity Transmission Lines for Phased Arrays

    NASA Technical Reports Server (NTRS)

    Host, Nick; Chen, Chi-Chih; Volakis, John L.; Miranda, Felix

    2013-01-01

    Phased array antennas showcase many advantages over mechanically steered systems. However, they are also more complex, heavy and most importantly costly. This presentation paper presents a concept which overcomes these detrimental attributes by eliminating all of the phase array backend (including phase shifters). Instead, a wave velocity reconfigurable transmission line is used in a series fed array arrangement to allow phase shifting with one small (100mil) mechanical motion. Different configurations of the reconfigurable wave velocity transmission line are discussed and simulated and experimental results are presented.

  5. HIGH FREQUENCY POWER TRANSMISSION LINE FOR CYCLOTRONS AND THE LIKE

    DOEpatents

    Armstrong, W.J.

    1954-04-20

    High-frequency power transmission systems, particularly a stacked capacitance alternating power current transmission line wherein maximum utilization of the effective conductios skin of the line conductors is achieved while enabling a low impedance to be obtained are reported. The transmission line consists of a number of flat metal strips with interleaved dielectric strips. The metal dielectric strips are coiled spirally with the axis of the spiral extending along the length of the strips, and the alternating metal strips at the output end have outwardly extending aligned lugs which are directly strapped together and connected to the respective terminals on the load. At the input end of the transmission line, similarly, the alternate metal strips are directly strapped together and connected to an altereating current source. With the arrangement described each metal strip conducts on both sides, so that the metal strips are designed to have a thickness corresponding to twice the depth of the "skin effect" conducting lamina of each conductor at the source frequency.

  6. Casper to Dave Johnston 230-kV Transmission Line Project: Environmental assessment

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

    Not Available

    1986-01-01

    Western proposes to reconstruct the existing Casper-Glendo North 115-kV Transmission Line to 230-kV between a point 1.1 miles northeast of the Pacific Power and Light (Pacific) Casper Substation and the Dave Johnston (DJ) Powerplant near Glenrock, Wyoming. As part of the proposed action, Western proposes to remove the portion of the existing Casper-Glendo South 115-kV Transmission Line between Western's Casper Substation and the intersection with the Casper-Glendo North Transmission Line, about 15 miles east of Casper. The removed portion of the Casper-Glendo North Transmission Line would be rebuilt on steel, single-shaft, structures. The section between the point northeast of themore » Pacific Substation and the intersection with the Casper-Glendo South Transmission Line would be double circuit (230-kV/115-kV). At the intersection of the north and south lines, the new 115-kV section would be tied to the remaining portion of the Casper-Glendo South Line to complete the 115-kV Casper-Glendo circuit. 52 refs.,12 figs., 14 tabs.« less

  7. Gas insulated transmission line having tapered particle trapping ring

    DOEpatents

    Cookson, Alan H.

    1982-01-01

    A gas-insulated transmission line includes an outer sheath, an inner conductor, insulating supports and an insulating gas. A particle-trapping ring is secured to each insulating support, and it is comprised of a central portion and two tapered end portions. The ends of the particle trapping ring have a smaller diameter than the central portion of the ring, so as to enable the use of the particle trapping ring in a curved transmission line.

  8. Sound transmission of cavity walls due to structure borne transmission via point and line connections.

    PubMed

    Davy, John L

    2012-08-01

    The author has published equations for predicting the air borne sound transmission of double leaf cavity walls due to the structure borne sound transmission across the air cavity via (possibly resilient) line connections, but has never published the full derivation of these equations. The author also derived equations for the case when the connections are rigid point connections but has never used them or published them or their derivations. This paper will present the full derivation of the author's theory of the air borne sound transmission of double leaf cavity walls due to the structure borne sound transmission across the air cavity via point or line connections which are modeled as four pole networks. The theoretical results will be compared with experimental results on wooden stud cavity walls from the National Research Council of Canada because the screw spacing is given for these results. This enables connections via studs and screws to be modeled as point connections and avoids the need to make any assumptions about the compliance of the equivalent point or line connections.

  9. Self-monitoring high voltage transmission line suspension insulator

    DOEpatents

    Stemler, Gary E.; Scott, Donald N.

    1981-01-01

    A high voltage transmission line suspension insulator (18 or 22) which monitors its own dielectric integrity. A dielectric rod (10) has one larger diameter end fitting attachable to a transmission line and another larger diameter end fitting attachable to a support tower. The rod is enclosed in a dielectric tube (14) which is hermetically sealed to the rod's end fittings such that a liquidtight space (20) is formed between the rod and the tube. A pressurized dielectric liquid is placed within that space. A discoloring dye placed within this space is used to detect the loss of the pressurized liquid.

  10. 18 CFR 2.2 - Transmission lines.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Transmission lines. 2.2 Section 2.2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES GENERAL POLICY AND INTERPRETATIONS Statements of General Policy and Interpretations...

  11. 18 CFR 2.2 - Transmission lines.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 18 Conservation of Power and Water Resources 1 2012-04-01 2012-04-01 false Transmission lines. 2.2 Section 2.2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES GENERAL POLICY AND INTERPRETATIONS Statements of General Policy and Interpretations...

  12. 18 CFR 2.2 - Transmission lines.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 18 Conservation of Power and Water Resources 1 2013-04-01 2013-04-01 false Transmission lines. 2.2 Section 2.2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES GENERAL POLICY AND INTERPRETATIONS Statements of General Policy and Interpretations...

  13. 18 CFR 2.2 - Transmission lines.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 18 Conservation of Power and Water Resources 1 2014-04-01 2014-04-01 false Transmission lines. 2.2 Section 2.2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES GENERAL POLICY AND INTERPRETATIONS Statements of General Policy and Interpretations...

  14. E-Textile Embroidered Metamaterial Transmission Line for Signal Propagation Control.

    PubMed

    Moradi, Bahareh; Fernández-García, Raul; Gil, Ignacio

    2018-06-05

    In this paper, the utilization of common fabrics for the manufacturing of e-textile metamaterial transmission lines is investigated. In order to filter and control the signal propagation in the ultra-high frequency (UHF) range along the e-textile, a conventional metamaterial transmission line was compared with embroidered metamaterial particles. The proposed design was based on a transmission line loaded with one or several split-ring resonators (SRR) on a felt substrate. To explore the relations between physical parameters and filter performance characteristics, theoretical models based on transmission matrices' description of the filter constituent components were proposed. Excellent agreement between theoretical prediction, electromagnetic simulations, and measurement were found. Experimental results showed stop-band levels higher than -30 dB for compact embroidered metamaterial e-textiles. The validated results confirmed embroidery as a useful technique to obtain customized electromagnetic properties, such as filtering, on wearable applications.

  15. TLINES: A Computer Program for Circuits of Transmission Lines.

    DTIC Science & Technology

    1983-12-01

    of various lengths are handled by stringing together many short lines, with the assumption that each of the longer lines has a length approximated as...expressed in terms of transmission lines numbered from 2 through CAPM , connected in numerical sequence as in figure 3. Line 1 is a dummy element disconnected...from line 2 and the rest of the circuit. Lines 2 through CAPM can each be set to any impedance the user desires. Line CAPM +1 is a zero-impedance line

  16. Study of transmission line attenuation in broad band millimeter wave frequency range.

    PubMed

    Pandya, Hitesh Kumar B; Austin, M E; Ellis, R F

    2013-10-01

    Broad band millimeter wave transmission lines are used in fusion plasma diagnostics such as electron cyclotron emission (ECE), electron cyclotron absorption, reflectometry and interferometry systems. In particular, the ECE diagnostic for ITER will require efficient transmission over an ultra wide band, 100 to 1000 GHz. A circular corrugated waveguide transmission line is a prospective candidate to transmit such wide band with low attenuation. To evaluate this system, experiments of transmission line attenuation were performed and compared with theoretical loss calculations. A millimeter wave Michelson interferometer and a liquid nitrogen black body source are used to perform all the experiments. Atmospheric water vapor lines and continuum absorption within this band are reported. Ohmic attenuation in corrugated waveguide is very low; however, there is Bragg scattering and higher order mode conversion that can cause significant attenuation in this transmission line. The attenuation due to miter bends, gaps, joints, and curvature are estimated. The measured attenuation of 15 m length with seven miter bends and eighteen joints is 1 dB at low frequency (300 GHz) and 10 dB at high frequency (900 GHz), respectively.

  17. Fuzzy logic based on-line fault detection and classification in transmission line.

    PubMed

    Adhikari, Shuma; Sinha, Nidul; Dorendrajit, Thingam

    2016-01-01

    This study presents fuzzy logic based online fault detection and classification of transmission line using Programmable Automation and Control technology based National Instrument Compact Reconfigurable i/o (CRIO) devices. The LabVIEW software combined with CRIO can perform real time data acquisition of transmission line. When fault occurs in the system current waveforms are distorted due to transients and their pattern changes according to the type of fault in the system. The three phase alternating current, zero sequence and positive sequence current data generated by LabVIEW through CRIO-9067 are processed directly for relaying. The result shows that proposed technique is capable of right tripping action and classification of type of fault at high speed therefore can be employed in practical application.

  18. Vacuum-barrier window for wide-bandwidth high-power microwave transmission

    DOEpatents

    Caplan, Malcolm; Shang, Clifford C.

    1996-01-01

    A vacuum output window comprises a planar dielectric material with identical systems of parallel ridges and valleys formed in opposite surfaces. The valleys in each surface neck together along parallel lines in the bulk of the dielectric. Liquid-coolant conduits are disposed linearly along such lines of necking and have water or even liquid nitrogen pumped through to remove heat. The dielectric material can be alumina, or its crystalline form, sapphire. The electric-field of a broadband incident megawatt millimeter-wave radio frequency energy is oriented perpendicular to the system of ridges and valleys. The ridges, about one wavelength tall and with a period of about one wavelength, focus the incident energy through in ribbons that squeeze between the liquid-coolant conduits without significant losses over very broad bands of the radio spectrum. In an alternative embodiment, the liquid-coolant conduits are encased in metal within the bulk of the dielectric.

  19. Wireless Sensor Network for Electric Transmission Line Monitoring

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

    Alphenaar, Bruce

    Generally, federal agencies tasked to oversee power grid reliability are dependent on data from grid infrastructure owners and operators in order to obtain a basic level of situational awareness. Since there are many owners and operators involved in the day-to-day functioning of the power grid, the task of accessing, aggregating and analyzing grid information from these sources is not a trivial one. Seemingly basic tasks such as synchronizing data timestamps between many different data providers and sources can be difficult as evidenced during the post-event analysis of the August 2003 blackout. In this project we investigate the efficacy and costmore » effectiveness of deploying a network of wireless power line monitoring devices as a method of independently monitoring key parts of the power grid as a complement to the data which is currently available to federal agencies from grid system operators. Such a network is modeled on proprietary power line monitoring technologies and networks invented, developed and deployed by Genscape, a Louisville, Kentucky based real-time energy information provider. Genscape measures transmission line power flow using measurements of electromagnetic fields under overhead high voltage transmission power lines in the United States and Europe. Opportunities for optimization of the commercial power line monitoring technology were investigated in this project to enable lower power consumption, lower cost and improvements to measurement methodologies. These optimizations were performed in order to better enable the use of wireless transmission line monitors in large network deployments (perhaps covering several thousand power lines) for federal situational awareness needs. Power consumption and cost reduction were addressed by developing a power line monitor using a low power, low cost wireless telemetry platform known as the ''Mote''. Motes were first developed as smart sensor nodes in wireless mesh networking applications. On such a

  20. Microstrip transmission line for soil moisture measurement

    NASA Astrophysics Data System (ADS)

    Chen, Xuemin; Li, Jing; Liang, Renyue; Sun, Yijie; Liu, C. Richard; Rogers, Richard; Claros, German

    2004-12-01

    Pavement life span is often affected by the amount of voids in the base and subgrade soils, especially moisture content in pavement. Most available moisture sensors are based on the capacitive sensing using planar blades. Since the planar sensor blades are fabricated on the same surface to reduce the overall size of the sensor, such structure cannot provide very high accuracy for moisture content measurement. As a consequence, a typical capacitive moisture sensor has an error in the range of 30%. A more accurate measurement is based on the time domain refelctometer (TDR) measurement. However, typical TDR system is fairly expensive equipment, very large in size, and difficult to operate, the moisture content measurement is limited. In this paper, a novel microstrip transmission line based moisture sensor is presented. This sensor uses the phase shift measurement of RF signal going through a transmission line buried in the soil to be measured. Since the amplitude of the transmission measurement is a strong function of the conductivity (loss of the media) and the imaginary part of dielectric constant, and the phase is mainly a strong function of the real part of the dielectric constant, measuring phase shift in transmission mode can directly obtain the soil moisture information. This sensor was designed and implemented. Sensor networking was devised. Both lab and field data show that this sensor is sensitive and accurate.

  1. Broadband parametric amplifiers based on nonlinear kinetic inductance artificial transmission lines

    NASA Astrophysics Data System (ADS)

    Chaudhuri, S.; Li, D.; Irwin, K. D.; Bockstiegel, C.; Hubmayr, J.; Ullom, J. N.; Vissers, M. R.; Gao, J.

    2017-04-01

    We present broadband parametric amplifiers based on the kinetic inductance of superconducting NbTiN thin films in an artificial (lumped-element) transmission line architecture. We demonstrate two amplifier designs implementing different phase matching techniques: periodic impedance loading and resonator phase shifters placed periodically along the transmission line. Our design offers several advantages over previous CPW-based amplifiers, including intrinsic 50 Ω characteristic impedance, natural suppression of higher pump harmonics, lower required pump power, and shorter total trace length. Experimental realizations of both versions of the amplifiers are demonstrated. With a transmission line length of 20 cm, we have achieved gains of 15 dB over several GHz of bandwidth.

  2. Research on UAV Intelligent Obstacle Avoidance Technology During Inspection of Transmission Line

    NASA Astrophysics Data System (ADS)

    Wei, Chuanhu; Zhang, Fei; Yin, Chaoyuan; Liu, Yue; Liu, Liang; Li, Zongyu; Wang, Wanguo

    Autonomous obstacle avoidance of unmanned aerial vehicle (hereinafter referred to as UAV) in electric power line inspection process has important significance for operation safety and economy for UAV intelligent inspection system of transmission line as main content of UAV intelligent inspection system on transmission line. In the paper, principles of UAV inspection obstacle avoidance technology of transmission line are introduced. UAV inspection obstacle avoidance technology based on particle swarm global optimization algorithm is proposed after common obstacle avoidance technologies are studied. Stimulation comparison is implemented with traditional UAV inspection obstacle avoidance technology which adopts artificial potential field method. Results show that UAV inspection strategy of particle swarm optimization algorithm, adopted in the paper, is prominently better than UAV inspection strategy of artificial potential field method in the aspects of obstacle avoidance effect and the ability of returning to preset inspection track after passing through the obstacle. An effective method is provided for UAV inspection obstacle avoidance of transmission line.

  3. Transmission Line Ampacity Improvements of AltaLink Wind Plant Overhead Tie-Lines Using Weather-Based Dynamic Line Rating

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

    Bhattarai, Bishnu P.; Gentle, Jake P.; Hill, Porter

    Abstract—Overhead transmission lines (TLs) are conventionally given seasonal ratings based on conservative environmental assumptions. Such an approach often results in underutilization of the line ampacity as the worst conditions prevail only for a short period over a year/season. We presents dynamic line rating (DLR) as an enabling smart grid technology that adaptively computes ratings of TLs based on local weather conditions to utilize additional headroom of existing lines. In particular, general line ampacity state solver utilizes measured weather data for computing the real-time thermal rating of the TLs. The performance of the presented method is demonstrated from a field studymore » of DLR technology implementation on four TL segments at AltaLink, Canada. The performance is evaluated and quantified by comparing the existing static and proposed dynamic line ratings, and the potential benefits of DLR for enhanced transmission assets utilization. For the given line segments, the proposed DLR results in real-time ratings above the seasonal static ratings for most of the time; up to 95.1% of the time, with a mean increase of 72% over static rating.« less

  4. Study of transmission line attenuation in broad band millimeter wave frequency range

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

    Pandya, Hitesh Kumar B.; Austin, M. E.; Ellis, R. F.

    2013-10-15

    Broad band millimeter wave transmission lines are used in fusion plasma diagnostics such as electron cyclotron emission (ECE), electron cyclotron absorption, reflectometry and interferometry systems. In particular, the ECE diagnostic for ITER will require efficient transmission over an ultra wide band, 100 to 1000 GHz. A circular corrugated waveguide transmission line is a prospective candidate to transmit such wide band with low attenuation. To evaluate this system, experiments of transmission line attenuation were performed and compared with theoretical loss calculations. A millimeter wave Michelson interferometer and a liquid nitrogen black body source are used to perform all the experiments. Atmosphericmore » water vapor lines and continuum absorption within this band are reported. Ohmic attenuation in corrugated waveguide is very low; however, there is Bragg scattering and higher order mode conversion that can cause significant attenuation in this transmission line. The attenuation due to miter bends, gaps, joints, and curvature are estimated. The measured attenuation of 15 m length with seven miter bends and eighteen joints is 1 dB at low frequency (300 GHz) and 10 dB at high frequency (900 GHz), respectively.« less

  5. Some Little-Known Facts about Transmission Lines and Some New Results

    ERIC Educational Resources Information Center

    Dutta Roy, Suhash C.

    2010-01-01

    The study of transmission lines forms an integral part of any curriculum in electrical engineering. This paper presents some little-known but interesting facts about transmission lines, which are generally not found in textbooks, along with some new facts, which arose as extensions of these little-known ones. The facts highlighted in this paper…

  6. Application of magnetically insulated transmission lines for high current, high voltage electron beam accelerators

    NASA Astrophysics Data System (ADS)

    Shope, S. L.; Mazarakis, M. G.; Frost, C. A.; Poukey, J. W.; Turman, B. N.

    Self Magnetically Insulated Transmission Lines (MITL) adders were used successfully in a number of Sandia accelerators such as HELIA, HERMES III, and SABRE. Most recently we used at MITL adder in the RADLAC/SMILE electron beam accelerator to produce high quality, small radius (r(sub rho) less than 2 cm), 11 - 15 MeV, 50 - 100-kA beams with a small transverse velocity v(perpendicular)/c = beta(perpendicular) less than or equal to 0.1. In RADLAC/SMILE, a coaxial MITL passed through the eight, 2 MV vacuum envelopes. The MITL summed the voltages of all eight feeds to a single foilless diode. The experimental results are in good agreement with code simulations. Our success with the MITL technology led us to investigate the application to higher energy accelerator designs. We have a conceptual design for a cavity-fed MITL that sums the voltages from 100 identical, inductively-isolated cavities. Each cavity is a toroidal structure that is driven simultaneously by four 8-ohm pulse-forming lines, providing a 1-MV voltage pulse to each of the 100 cavities. The point design accelerator is 100 MV, 500 kA, with a 30 - 50 ns FWHM output pulse.

  7. A study of LC-39 cryogenic systems. Part 1: A study of the vacuum insulated transfer lines at Kennedy Space Center. Part 2: Cooldown pressure surges

    NASA Technical Reports Server (NTRS)

    Ludtke, P. R.; Voth, R. O.

    1971-01-01

    The vacuum liquid hydrogen and liquid oxygen transfer lines at Kennedy Space Center were studied to evaluate the feasibility of using a condensing gas such as CO2 inside the vacuum spaces to achieve a condensing-vacuum. The study indicates that at ambient temperature, a maximum vacuum hyphen space pressure of 4000 microns is acceptable for the LH2 transfer lines. In addition, the cooldown procedures for the 14-inch cross-country liquid oxygen line was studied using a simplified mathematical model. Preliminary cooldown times are presented for various heat leak rates to the line and for two vent configurations.

  8. Broadband parametric amplifiers based on nonlinear kinetic inductance artificial transmission lines

    DOE PAGES

    Chaudhuri, S.; Li, D.; Irwin, K. D.; ...

    2017-04-10

    Here, we present broadband parametric amplifiers based on the kinetic inductance of superconducting NbTiN thin films in an artificial (lumped-element) transmission line architecture. We demonstrate two amplifier designs implementing different phase matching techniques: periodic impedance loading and resonator phase shifters placed periodically along the transmission line. Our design offers several advantages over previous CPW-based amplifiers, including intrinsic 50 Ω characteristic impedance, natural suppression of higher pump harmonics, lower required pump power, and shorter total trace length. Experimental realizations of both versions of the amplifiers are demonstrated. In conclusion, with a transmission line length of 20 cm, we have achieved gainsmore » of 15 dB over several GHz of bandwidth.« less

  9. Broadband parametric amplifiers based on nonlinear kinetic inductance artificial transmission lines

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

    Chaudhuri, S.; Li, D.; Irwin, K. D.

    Here, we present broadband parametric amplifiers based on the kinetic inductance of superconducting NbTiN thin films in an artificial (lumped-element) transmission line architecture. We demonstrate two amplifier designs implementing different phase matching techniques: periodic impedance loading and resonator phase shifters placed periodically along the transmission line. Our design offers several advantages over previous CPW-based amplifiers, including intrinsic 50 Ω characteristic impedance, natural suppression of higher pump harmonics, lower required pump power, and shorter total trace length. Experimental realizations of both versions of the amplifiers are demonstrated. In conclusion, with a transmission line length of 20 cm, we have achieved gainsmore » of 15 dB over several GHz of bandwidth.« less

  10. Vacuum-barrier window for wide-bandwidth high-power microwave transmission

    DOEpatents

    Caplan, M.; Shang, C.C.

    1996-08-20

    A vacuum output window comprises a planar dielectric material with identical systems of parallel ridges and valleys formed in opposite surfaces. The valleys in each surface neck together along parallel lines in the bulk of the dielectric. Liquid-coolant conduits are disposed linearly along such lines of necking and have water or even liquid nitrogen pumped through to remove heat. The dielectric material can be alumina, or its crystalline form, sapphire. The electric-field of a broadband incident megawatt millimeter-wave radio frequency energy is oriented perpendicular to the system of ridges and valleys. The ridges, about one wavelength tall and with a period of about one wavelength, focus the incident energy through in ribbons that squeeze between the liquid-coolant conduits without significant losses over very broad bands of the radio spectrum. In an alternative embodiment, the liquid-coolant conduits are encased in metal within the bulk of the dielectric. 4 figs.

  11. The Effect Analysis of Strain Rate on Power Transmission Tower-Line System under Seismic Excitation

    PubMed Central

    Wang, Wenming

    2014-01-01

    The effect analysis of strain rate on power transmission tower-line system under seismic excitation is studied in this paper. A three-dimensional finite element model of a transmission tower-line system is created based on a real project. Using theoretical analysis and numerical simulation, incremental dynamic analysis of the power transmission tower-line system is conducted to investigate the effect of strain rate on the nonlinear responses of the transmission tower and line. The results show that the effect of strain rate on the transmission tower generally decreases the maximum top displacements, but it would increase the maximum base shear forces, and thus it is necessary to consider the effect of strain rate on the seismic analysis of the transmission tower. The effect of strain rate could be ignored for the seismic analysis of the conductors and ground lines, but the responses of the ground lines considering strain rate effect are larger than those of the conductors. The results could provide a reference for the seismic design of the transmission tower-line system. PMID:25105157

  12. Analogue Hawking radiation in a dc-SQUID array transmission line.

    PubMed

    Nation, P D; Blencowe, M P; Rimberg, A J; Buks, E

    2009-08-21

    We propose the use of a superconducting transmission line formed from an array of direct-current superconducting quantum interference devices for investigating analogue Hawking radiation. Biasing the array with a space-time varying flux modifies the propagation velocity of the transmission line, leading to an effective metric with a horizon. Being a fundamentally quantum mechanical device, this setup allows for investigations of quantum effects such as backreaction and analogue space-time fluctuations on the Hawking process.

  13. A Proposal for a High-Voltage Transmission Line Directional Coupler

    DOE PAGES

    Olsen, R. G.; Li, Zhi

    2017-02-01

    Directional couplers are devices generally used in high frequency transmission lines and waveguides that respond to forward and reverse traveling waves separately. Hence they can be used to either measure standing wave ratio in the steady state or to determine the direction of a propagating transient wave. Here, a design is proposed for a directional coupler to be used on multimode high voltage transmission lines. Its performance is analyzed and several suggestions are made for improving its design.

  14. Microwave Analysis with Monte Carlo Methods for ECH Transmission Lines

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

    Kaufman, Michael C.; Lau, Cornwall H.; Hanson, Gregory R.

    A new code framework, MORAMC, is presented which model transmission line (TL) systems consisting of overmoded circular waveguide and other components including miter bends and transmission line gaps. The transmission line is modeled as a set of mode converters in series where each component is composed of one or more converters. The parametrization of each mode converter can account for the fabrication tolerances of physically realizable components. These tolerances as well as the precision to which these TL systems can be installed and aligned gives a practical limit to which the uncertainty of the microwave performance of the system canmore » be calculated. Because of this, Monte Carlo methods are a natural fit and are employed to calculate the probability distribution that a given TL can deliver a required power and mode purity. Several examples are given to demonstrate the usefulness of MORAMC in optimizing TL systems.« less

  15. Microwave Analysis with Monte Carlo Methods for ECH Transmission Lines

    DOE PAGES

    Kaufman, Michael C.; Lau, Cornwall H.; Hanson, Gregory R.

    2018-03-08

    A new code framework, MORAMC, is presented which model transmission line (TL) systems consisting of overmoded circular waveguide and other components including miter bends and transmission line gaps. The transmission line is modeled as a set of mode converters in series where each component is composed of one or more converters. The parametrization of each mode converter can account for the fabrication tolerances of physically realizable components. These tolerances as well as the precision to which these TL systems can be installed and aligned gives a practical limit to which the uncertainty of the microwave performance of the system canmore » be calculated. Because of this, Monte Carlo methods are a natural fit and are employed to calculate the probability distribution that a given TL can deliver a required power and mode purity. Several examples are given to demonstrate the usefulness of MORAMC in optimizing TL systems.« less

  16. Microwave Analysis with Monte Carlo Methods for ECH Transmission Lines

    NASA Astrophysics Data System (ADS)

    Kaufman, M. C.; Lau, C.; Hanson, G. R.

    2018-03-01

    A new code framework, MORAMC, is presented which model transmission line (TL) systems consisting of overmoded circular waveguide and other components including miter bends and transmission line gaps. The transmission line is modeled as a set of mode converters in series where each component is composed of one or more converters. The parametrization of each mode converter can account for the fabrication tolerances of physically realizable components. These tolerances as well as the precision to which these TL systems can be installed and aligned gives a practical limit to which the uncertainty of the microwave performance of the system can be calculated. Because of this, Monte Carlo methods are a natural fit and are employed to calculate the probability distribution that a given TL can deliver a required power and mode purity. Several examples are given to demonstrate the usefulness of MORAMC in optimizing TL systems.

  17. Transmission expansion with smart switching under demand uncertainty and line failures

    DOE PAGES

    Schumacher, Kathryn M.; Chen, Richard Li-Yang; Cohn, Amy E. M.

    2016-06-07

    One of the major challenges in deciding where to build new transmission lines is that there is uncertainty regarding future loads, renewal generation output and equipment failures. We propose a robust optimization model whose transmission expansion solutions ensure that demand can be met over a wide range of conditions. Specifically, we require feasible operation for all loads and renewable generation levels within given ranges, and for all single transmission line failures. Furthermore, we consider transmission switching as an allowable recovery action. This relatively inexpensive method of redirecting power flows improves resiliency, but introduces computational challenges. Lastly, we present a novelmore » algorithm to solve this model. Computational results are discussed.« less

  18. The Evaluation Method of the Lightning Strike on Transmission Lines Aiming at Power Grid Reliability

    NASA Astrophysics Data System (ADS)

    Wen, Jianfeng; Wu, Jianwei; Huang, Liandong; Geng, Yinan; Yu, zhanqing

    2018-01-01

    Lightning protection of power system focuses on reducing the flashover rate, only distinguishing by the voltage level, without considering the functional differences between the transmission lines, and being lack of analysis the effect on the reliability of power grid. This will lead lightning protection design of general transmission lines is surplus but insufficient for key lines. In order to solve this problem, the analysis method of lightning striking on transmission lines for power grid reliability is given. Full wave process theory is used to analyze the lightning back striking; the leader propagation model is used to describe the process of shielding failure of transmission lines. The index of power grid reliability is introduced and the effect of transmission line fault on the reliability of power system is discussed in detail.

  19. Sound Transmission Through Multi-Panel Structures Lined with Elastic Porous Materials

    NASA Astrophysics Data System (ADS)

    Bolton, J. S.; Shiau, N.-M.; Kang, Y. J.

    1996-04-01

    Theory and measurements related to sound transmission through double panels lined with elastic porous media are presented. The information has application to the design of noise control barriers and to the optimization of aircraft fuselage transmission loss, for example. The major difference between the work described here and earlier research in this field relates to the treatment of the porous material that is used to line the cavity between the two panels of the double panel structure. Here we have used the porous material theory proposed by Biot since it takes explicit account of all the wave types known to propagate in elastic porous materials. As a result, it is possible to use the theory presented here to calculate the transmission loss of lined double panels at arbitrary angles of incidence; results calculated over a range of incidence angles may then be combined to yield the random incidence transmission loss. In this paper, the equations governing wave propagation in an elastic porous material are first considered briefly and then the general forms for the stresses and displacements within the porous material are given. Those solutions are expressed in terms of a number of constants that can be determined by application of appropriate boundary conditions. The boundary conditions required to model double panels having linings that are either directly attached to the facing panels or separated?!from them by air gaps are presented and discussed. Measurements of the random incidence transmission loss of aluminium double-panel structures lined with polyurethane foam are presented and have been found to be in good agreement with theoretical predictions. Both the theoretical predictions and the measured results have shown that the method by which an elastic porous lining material is attached to the facing panels can have a profound influence on the transmission loss of the panel system. It has been found, for example, that treatments in which the lining material

  20. Big Creek Hydroelectric System, East & West Transmission Line, 241mile ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Big Creek Hydroelectric System, East & West Transmission Line, 241-mile transmission corridor extending between the Big Creek Hydroelectric System in the Sierra National Forest in Fresno County and the Eagle Rock Substation in Los Angeles, California, Visalia, Tulare County, CA

  1. ACHP | News | ACHP Issue Spotlight: Transmission Lines in the West

    Science.gov Websites

    effects. Some historic properties are affected by several of these lines, and some lines have multiple parts of Idaho and Montana. There are potential effects to a number of important historic properties impact, visual effects of this transmission line, will be approximated through "backsighted analysis

  2. Simulation of stochastic wind action on transmission power lines

    NASA Astrophysics Data System (ADS)

    Wielgos, Piotr; Lipecki, Tomasz; Flaga, Andrzej

    2018-01-01

    The paper presents FEM analysis of the wind action on overhead transmission power lines. The wind action is based on a stochastic simulation of the wind field in several points of the structure and on the wind tunnel tests on aerodynamic coefficients of the single conductor consisting of three wires. In FEM calculations the section of the transmission power line composed of three spans is considered. Non-linear analysis with deadweight of the structure is performed first to obtain the deformed shape of conductors. Next, time-dependent wind forces are applied to respective points of conductors and non-linear dynamic analysis is carried out.

  3. Gates to Gregg High Voltage Transmission Line Study. [California

    NASA Technical Reports Server (NTRS)

    Bergis, V.; Maw, K.; Newland, W.; Sinnott, D.; Thornbury, G.; Easterwood, P.; Bonderud, J.

    1982-01-01

    The usefulness of LANDSAT data in the planning of transmission line routes was assessed. LANDSAT digital data and image processing techniques, specifically a multi-date supervised classification aproach, were used to develop a land cover map for an agricultural area near Fresno, California. Twenty-six land cover classes were identified, of which twenty classes were agricultural crops. High classification accuracies (greater than 80%) were attained for several classes, including cotton, grain, and vineyards. The primary products generated were 1:24,000, 1:100,000 and 1:250,000 scale maps of the classification and acreage summaries for all land cover classes within four alternate transmission line routes.

  4. 50 CFR 29.21-8 - Electric power transmission line rights-of-way.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Electric power transmission line rights-of... General Regulations § 29.21-8 Electric power transmission line rights-of-way. By accepting a right-of-way... with the rules prescribed in the National Electric Safety Code, all Government and other telephone...

  5. Dispersion-free radial transmission lines

    DOEpatents

    Caporaso, George J [Livermore, CA; Nelson, Scott D [Patterson, CA

    2011-04-12

    A dispersion-free radial transmission line ("DFRTL") preferably for linear accelerators, having two plane conductors each with a central hole, and an electromagnetically permeable material ("EPM") between the two conductors and surrounding a channel connecting the two holes. At least one of the material parameters of relative magnetic permeability, relative dielectric permittivity, and axial width of the EPM is varied as a function of radius, so that the characteristic impedance of the DFRTL is held substantially constant, and pulse transmission therethrough is substantially dispersion-free. Preferably, the EPM is divided into concentric radial sections, with the varied material parameters held constant in each respective section but stepwise varied between sections as a step function of the radius. The radial widths of the concentric sections are selected so that pulse traversal time across each section is the same, and the varied material parameters of the concentric sections are selected to minimize traversal error.

  6. 14 CFR 29.1433 - Vacuum systems.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Equipment Miscellaneous Equipment § 29.1433 Vacuum systems. (a... the discharge lines from the vacuum air pump when the delivery temperature of the air becomes unsafe. (b) Each vacuum air system line and fitting on the discharge side of the pump that might contain...

  7. 75 FR 56051 - Bemidji to Grand Rapids Minnesota 230 kV Transmission Line Project

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-15

    ... Service Bemidji to Grand Rapids Minnesota 230 kV Transmission Line Project AGENCY: Rural Utilities Service... Environmental Impact Statement (EIS) for the proposed Bemidji to Grand Rapids, Minnesota 230 kV Transmission... Cooperative, Inc. for RUS financing to construct a 230 kilovolt (kV) transmission line between the Wilton...

  8. A Plasma Window for Transmission of Radiation and Particle Beams from Vacuum to Atmosphere for Various Applications

    NASA Astrophysics Data System (ADS)

    Hershcovitch, Ady

    1997-11-01

    Many industrial and scientific processes like electron beam melting and welding, material modification by ion implantation, dry etching, and micro-fabrication, as well as generation of synchrotron radiation are performed almost exclusively in vacuum nowadays, since the electron and ion guns and their extractors must be kept at a reasonably high vacuum. Consequently, there are numerous drawbacks, among which are low production rates due to required pumping time, limits the vacuum volume sets on the size of target objects. In a small number of applications like non-vacuum electron beam welding, and various processes involving UV and x-ray radiation, thin vacuum walls or long stages of differential pumping are used. But, the resultant degradations of particle and radiation beams severely limit those applications. A novel apparatus, which utilized a short plasma arc, was successfully used to maintain a pressure of 7.6 x exp(-6) Torr in a vacuum chamber with a 2.36mm aperture to atmosphere, i.e., a plasma was successfully used to "plug" a hole to atmosphere while maintaining a reasonably high vacuum in the chamber. Successful transmission of charged particle beams from a vacuum through the plasma to atmosphere was accomplished. More details can be found in A. Hershcovitch, J. Appl. Physics 78, p. 5283 (1995). In addition to sustaining a vacuum atmosphere interface, the plasma has very strong lensing effect on charged particles. The plasma current generates an azimuthal magnetic field which exerts a radial Lorentz on charged particles moving parallel to the current channel. With proper orientation of the current direction, the Lorentz force is radially inward. This feature can be used to focus in beams to a very small spot size, and to overcome beam dispersion due to scattering by atmospheric atoms and molecules. Relatively hot plasma at the atmosphere boundary rarefies the atmospheric gases to further enhance particle beam propagation to the materials to target. Recent

  9. 32 CFR 644.431 - Power transmission lines.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 1944, as amended (50 U.S.C., App. 1622(d)), any state, or political subdivision thereof, or any state... transmission line and the right of way acquired for its construction is needed for or adaptable to the... in all cases. (b) Procedure. Whenever a State, or political subdivision thereof, or state or Federal...

  10. The effects of high voltage transmission lines on honey bees. Interim report. [765 kV transmission line

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

    Greenberg, B.; Kunich, J.C.; Bindokas, V.P.

    1978-10-01

    Results of the first year's field study of possible effects on honey bees of a 765 kV transmission line are reported. Conventional hives and metal-free hives, shielded and unshielded, were placed under the line (E-field, ca. 7 kV/m) and in a control area (E-field, ca. 10 V/m) about 400 m away. Bees in unshielded conventional hives under the line weighed less, stored little honey whose moisture content was subnormal (hive weight gain was essentially zero), propolyzed hive entrances excessively but not completely, produced fewer pupae but normal numbers of eggs and larvae, and failed to survive the winter. Unshielded metal-freemore » hives under the line had the following normal features: bee weight; hive weight gain; honey moisture content; and number of eggs, larvae, and pupae. Their abnormal features were: propolization of hive entrances, but at a slower rate and to a lesser extent than conventional hives; aggressive clusters of bees at lower front hive corners; poor overwintering survival; and possibly higher hemocyte counts.« less

  11. A radial transmission line material measurement apparatus

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

    Warne, L.K.; Moyer, R.D.; Koontz, T.E.

    1993-05-01

    A radial transmission line material measurement sample apparatus (sample holder, offset short standards, measurement software, and instrumentation) is described which has been proposed, analyzed, designed, constructed, and tested. The purpose of the apparatus is to obtain accurate surface impedance measurements of lossy, possibly anisotropic, samples at low and intermediate frequencies (vhf and low uhf). The samples typically take the form of sections of the material coatings on conducting objects. Such measurements thus provide the key input data for predictive numerical scattering codes. Prediction of the sample surface impedance from the coaxial input impedance measurement is carried out by two techniques.more » The first is an analytical model for the coaxial-to-radial transmission line junction. The second is an empirical determination of the bilinear transformation model of the junction by the measurement of three full standards. The standards take the form of three offset shorts (and an additional lossy Salisbury load), which have also been constructed. The accuracy achievable with the device appears to be near one percent.« less

  12. 76 FR 15970 - Central Ferry to Lower Monumental 500-kilovolt Transmission Line Project

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-22

    ...-kilovolt Transmission Line Project AGENCY: Bonneville Power Administration (BPA), Department of Energy (DOE... Project in Garfield, Columbia, and Walla Walla counties, Washington. BPA has decided to implement the... consists of constructing a new 500-kV single- circuit transmission line from BPA's new Central Ferry...

  13. Sound transmission through triple-panel structures lined with poroelastic materials

    NASA Astrophysics Data System (ADS)

    Liu, Yu

    2015-03-01

    In this paper, previous theories on the prediction of sound transmission loss for a double-panel structure lined with poroelastic materials are extended to address the problem of a triple-panel structure. Six typical configurations are considered for a triple-panel structure based on the method of coupling the porous layers to the facing panels which determines critically the sound insulation performance of the system. The transfer matrix method is employed to solve the system by applying appropriate types of boundary conditions for these configurations. The transmission loss of the triple-panel structures in a diffuse sound field is calculated as a function of frequency and compared with that of corresponding double-panel structures. Generally, the triple-panel structure with poroelastic linings has superior acoustic performance to the double-panel counterpart, remarkably in the mid-high frequency range and possibly at low frequencies, by selecting appropriate configurations in which those with two air gaps in the structure exhibit the best overall performance over the entire frequency range. The poroelastic lining significantly lowers the cut-on frequency above which the triple-panel structure exhibits noticeably higher transmission loss. Compared with a double-panel structure, the wider range of system parameters for a triple-panel structure due to the additional partition provides more design space for tuning the sound insulation performance. Despite the increased structural complexity, the triple-panel structure lined with poroelastic materials has the obvious advantages in sound transmission loss while without the penalties in weight and volume, and is hence a promising replacement for the widely used double-panel sandwich structure.

  14. Numerical noise analysis for insulator of overhead transmission line

    NASA Astrophysics Data System (ADS)

    Zhang, Yulin; Chen, Yuwen; Huang, Yu

    2018-04-01

    As an important and complex issue in aero acoustic field, a lot of explorations have been devoted to the wind-induced noise. However, there is still lack of intensive investigations for aerodynamic noise in high-voltage transmission. The overhead transmission line system leads to serious occupational noise exposure in high wind-speed environment, and the noise can even injure the electricians in charge of insulator. By using computational fluid dynamics (CFD) which combined with computational aero acoustics (CAA), this paper predicts the noise generated by insulator of high voltage electricity transmission line which explores in wind environment. The simulation results indicate that the wind velocity, the assembly angle of the insulator and its ribs' distribution are the main contributory factors for the aerodynamic noise. Specifically, when wind velocity is greater than 15m/s, the alteration of noise is not sensitive to the wind velocity; furthermore, when the assembly angle increases from 0°to 60°, the noise decreases gradually, however, if the angle is happening to be 75°or 90°, it would be even greater than that at 0°. In order to inhibit the aerodynamic noise, it is necessary to control the flow blowing across the boundary of the insulator. Consequently, the result indicates that if the outermost rib is shorter than the second one, the noise reduced evidently. This information expects to provide useful help for the extremely suppression of aerodynamic noise, and also supply practical reference material for the design and application of overhead transmission line system.

  15. Transmission Line Jobs and Economic Development Impact (JEDI) Model User Reference Guide

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

    Goldberg, M.; Keyser, D.

    The Jobs and Economic Development Impact (JEDI) models, developed through the National Renewable Energy Laboratory (NREL), are freely available, user-friendly tools that estimate the potential economic impacts of constructing and operating power generation projects for a range of conventional and renewable energy technologies. The Transmission Line JEDI model can be used to field questions about the economic impacts of transmission lines in a given state, region, or local community. This Transmission Line JEDI User Reference Guide was developed to provide basic instruction on operating the model and understanding the results. This guide also provides information on the model's underlying methodology,more » as well as the parameters and references used to develop the cost data contained in the model.« less

  16. Stand-off transmission lines and method for making same

    DOEpatents

    Tuckerman, David B.

    1991-01-01

    Standoff transmission lines in an integrated circuit structure are formed by etching away or removing the portion of the dielectric layer separating the microstrip metal lines and the ground plane from the regions that are not under the lines. The microstrip lines can be fabricated by a subtractive process of etching a metal layer, an additive process of direct laser writing fine lines followed by plating up the lines or a subtractive/additive process in which a trench is etched over a nucleation layer and the wire is electrolytically deposited. Microstrip lines supported on freestanding posts of dielectric material surrounded by air gaps are produced. The average dielectric constant between the lines and ground plane is reduced, resulting in higher characteristic impedance, less crosstalk between lines, increased signal propagation velocities, and reduced wafer stress.

  17. 76 FR 19698 - Safety Zone; Repair of High Voltage Transmission Lines to Logan International Airport, Saugus...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-08

    ...-AA00 Safety Zone; Repair of High Voltage Transmission Lines to Logan International Airport, Saugus... (COTP) Boston Zone to allow for repair of high voltage transmission lines to Logan Airport. This safety... voltage transmission lines. Entering into, transiting through, mooring or anchoring within this zone is...

  18. 76 FR 4575 - Safety Zone; Repair of High Voltage Transmission Lines to Logan International Airport, Saugus...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-26

    ...-AAOO Safety Zone; Repair of High Voltage Transmission Lines to Logan International Airport, Saugus... the Captain of the Port (COTP) Boston Zone to allow for repair of high voltage transmission lines to... the repair of high voltage transmission lines. Entering into, transiting through, mooring or anchoring...

  19. Fiber Optic Picosecond Laser Pulse Transmission Line for Hydrogen Ion Beam Profile Measurement

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

    Liu, Yun; Huang, Chunning; Aleksandrov, Alexander V

    2013-01-01

    We present a fiber optic laser pulse transmission line for non-intrusive longitudinal profile measurement of the hydrogen ion (H-) beam at the front-end of the Spallation Neutron Source (SNS) accelerator. The 80.5 MHz, 2.5 ps, multi-killowatt optical pulses are delivered to the accelerator beam line through a large mode area polarization maintaining optical fiber to ensure a high measurement stability. The transmission efficiency, output laser beam quality, pulse jitter and pulse width broadening over a 100-ft fiber line are experimentally investigated. A successful measurement of the H- beam microbunch (~130 ps) profile is obtained. Our experiment is the first demonstrationmore » of particle beam profile diagnostics using fiber optic laser pulse transmission line.« less

  20. Dynamic Responses and Vibration Control of the Transmission Tower-Line System: A State-of-the-Art Review

    PubMed Central

    Chen, Bo; Guo, Wei-hua; Li, Peng-yun; Xie, Wen-ping

    2014-01-01

    This paper presented an overview on the dynamic analysis and control of the transmission tower-line system in the past forty years. The challenges and future developing trends in the dynamic analysis and mitigation of the transmission tower-line system under dynamic excitations are also put forward. It also reviews the analytical models and approaches of the transmission tower, transmission lines, and transmission tower-line systems, respectively, which contain the theoretical model, finite element (FE) model and the equivalent model; shows the advances in wind responses of the transmission tower-line system, which contains the dynamic effects under common wind loading, tornado, downburst, and typhoon; and discusses the dynamic responses under earthquake and ice loads, respectively. The vibration control of the transmission tower-line system is also reviewed, which includes the magnetorheological dampers, friction dampers, tuned mass dampers, and pounding tuned mass dampers. PMID:25105161

  1. Dynamic simulation of relief line during loss of insulation vacuum of the ITER cryoline

    NASA Astrophysics Data System (ADS)

    Badgujar, S.; Kosek, J.; Grillot, D.; Forgeas, A.; Sarkar, B.; Shah, N.; Choukekar, K.; Chang, H.-S.

    2017-12-01

    The ITER cryoline (CL) system consists of 37 types of vacuum jacketed transfer lines which forms a complex structured network with a total length of about 5 km, spread inside the Tokamak building, on a dedicated plant bridge and in the Cryoplant building/area. One of them, the low pressure relief line (RL) recovers helium discharged from process safety relief valves of the different cryogenic users and is sent it back to the Cryoplant via heater and recovery system. The process pipe diameters of the RL vary from DN 50 to DN 200 and the length is more than 1500 m. Loss of insulation vacuum (LIV) of a CL is one of the worst scenarios apart from LIV in Auxiliary Cold Boxes (ACBs). The Torus and Cryostat CL is chosen to simulate the virtual LIV and to study the anticipated behavior of the RL. Both helium LIV (LIV due to leak in helium pipe) and air LIV (LIV due to air ingress in outer vacuum jacket of the cryoline) with and without fire) have been simulated during this study. After the brief description of the CL system, the paper will describe the EcosimPro® model prepared for the dynamic study. The paper will also describe the results like minimum temperature of RL, mass flow and maximum pressure in the RL which are essentially used to choose the type and location of safety relief devices to protect the CL process pipes.

  2. Frequency Selective Properties of Coaxial Transmission Lines Loaded with Combined Artificial Inclusions

    PubMed Central

    2014-01-01

    The properties of a modified coaxial transmission line by periodic inclusions will be discussed. The introduction of split ring resonators, conductor stubs, air gaps, and combination of these gives rise to new frequency selective properties, such as stopband or passband behavior, observable in planar as well as volumetric metamaterial structures. These results envisage new potential applications and implementation of devices in coaxial transmission line technology. PMID:24587748

  3. A transmission line method for the measurement of microwave permittivity and permeability

    NASA Astrophysics Data System (ADS)

    Lederer, P. G.

    1990-12-01

    A method for determining complex permittivity and permeability at microwave frequencies from two port S parameter measurements of lossy solids in coaxial or waveguide transmission lines is described. The use of the TRL (Through Reflect Line) calibration scheme allows the measuring system to be calibrated right up to the specimen faces thereby eliminating most of the sample cell from the measurement and allowing suitable materials to be molded directly into the specimen cell in order to eliminate air gaps between specimen and transmission line walls. Some illustrative measurements for dielectric and magnetic materials are presented.

  4. Stand-off transmission lines and method for making same

    DOEpatents

    Tuckerman, D.B.

    1991-05-21

    Standoff transmission lines in an integrated circuit structure are formed by etching away or removing the portion of the dielectric layer separating the microstrip metal lines and the ground plane from the regions that are not under the lines. The microstrip lines can be fabricated by a subtractive process of etching a metal layer, an additive process of direct laser writing fine lines followed by plating up the lines or a subtractive/additive process in which a trench is etched over a nucleation layer and the wire is electrolytically deposited. Microstrip lines supported on freestanding posts of dielectric material surrounded by air gaps are produced. The average dielectric constant between the lines and ground plane is reduced, resulting in higher characteristic impedance, less crosstalk between lines, increased signal propagation velocities, and reduced wafer stress. 16 figures.

  5. Maximizing Ion Transmission from Atmospheric Pressure into the Vacuum of Mass Spectrometers with a Novel Electrospray Interface

    PubMed Central

    Krutchinsky, Andrew N.; Padovan, Júlio C.; Cohen, Herbert; Chait, Brian T.

    2015-01-01

    We have discovered that an electrode containing a conical channel with a small angular divergence can transmit into the vacuum almost 100% of an electrospray ion current produced at atmospheric pressure. Our first implementation of such a conical duct, which we term “ConDuct”, uses a conductive plastic pipette tip containing a ≈1.6° divergent channel at its entrance. We observed that the beam formed by the ConDuct electrode has a very low divergence (< 1°) and persisted for long distances in vacuum. Intrigued by these properties, we incorporated this electrode into a novel atmosphere-to-vacuum ion transmission interface, and devised a technique for evaluating its performance relative to commercial reference interfaces that contain heated metal capillaries. We determined that our new interface transmits at least 400 times more ions than the commercial Thermo LCQ DECA XP atmosphere-to-vacuum interface and 2–3 times more than the commercial interface in the Thermo Velos Orbitrap and the Q Exactive mass spectrometers. We conclude that it might be possible to optimize the properties of the transmitted ions further by manufacturing ConDuct inlet electrodes from metal rather than conductive plastic and by determining the optimum angle of channel divergence and channel length. PMID:25588722

  6. Computer-aided Instructional System for Transmission Line Simulation.

    ERIC Educational Resources Information Center

    Reinhard, Erwin A.; Roth, Charles H., Jr.

    A computer-aided instructional system has been developed which utilizes dynamic computer-controlled graphic displays and which requires student interaction with a computer simulation in an instructional mode. A numerical scheme has been developed for digital simulation of a uniform, distortionless transmission line with resistive terminations and…

  7. Rolled-up transmission line structure for a radiofrequency integrated circuit (RFIC)

    DOEpatents

    Li, Xiuling; Huang, Wen

    2015-04-28

    A rolled-up transmission line structure for a radiofrequency integrated circuit (RFIC) comprises a multilayer sheet in a rolled configuration comprising multiple turns about a longitudinal axis, where the multilayer sheet comprises a conductive pattern layer on a strain-relieved layer. The conductive pattern layer comprises a first conductive film and a second conductive film separated from the first conductive film in a rolling direction. In the rolled configuration, the first conductive film surrounds the longitudinal axis, and the second conductive film surrounds the first conductive film. The first conductive film serves as a signal line and the second conductive film serves as a conductive shield for the rolled-up transmission line structure.

  8. Neural network method for lossless two-conductor transmission line equations based on the IELM algorithm

    NASA Astrophysics Data System (ADS)

    Yang, Yunlei; Hou, Muzhou; Luo, Jianshu; Liu, Taohua

    2018-06-01

    With the increasing demands for vast amounts of data and high-speed signal transmission, the use of multi-conductor transmission lines is becoming more common. The impact of transmission lines on signal transmission is thus a key issue affecting the performance of high-speed digital systems. To solve the problem of lossless two-conductor transmission line equations (LTTLEs), a neural network model and algorithm are explored in this paper. By selecting the product of two triangular basis functions as the activation function of hidden layer neurons, we can guarantee the separation of time, space, and phase orthogonality. By adding the initial condition to the neural network, an improved extreme learning machine (IELM) algorithm for solving the network weight is obtained. This is different to the traditional method for converting the initial condition into the iterative constraint condition. Calculation software for solving the LTTLEs based on the IELM algorithm is developed. Numerical experiments show that the results are consistent with those of the traditional method. The proposed neural network algorithm can find the terminal voltage of the transmission line and also the voltage of any observation point. It is possible to calculate the value at any given point by using the neural network model to solve the transmission line equation.

  9. Magnetically insulated transmission line oscillator

    DOEpatents

    Bacon, Larry D.; Ballard, William P.; Clark, M. Collins; Marder, Barry M.

    1988-01-01

    A magnetically insulated transmission line oscillator employs self-generated magnetic fields to generate microwave energy. An anode of the oscillator includes slow-wave structures which are formed of a plurality of thin conductive vanes defining cavities therebetween, and a gap is formed between the anode and a cathode of the oscillator. In response to a pulsed voltage applied to the anode and cathode, self-generated magnetic fields arfe produced in a cross-field orientation with respect to the orientation of the electric field between the anode and the cathode. The cross-field magnetic fields insulate the flow of electrons in the gap and confine the flow of electrons within the gap.

  10. Devices useful for vacuum ultraviolet beam characterization including a movable stage with a transmission grating and image detector

    DOEpatents

    Gessner, Oliver; Kornilov, Oleg A; Wilcox, Russell B

    2013-10-29

    The invention provides for a device comprising an apparatus comprising (a) a transmission grating capable of diffracting a photon beam into a diffracted photon output, and (b) an image detector capable of detecting the diffracted photon output. The device is useful for measuring the spatial profile and diffraction pattern of a photon beam, such as a vacuum ultraviolet (VUV) beam.

  11. Simple Correctors for Elimination of High-Order Modes in Corrugated Waveguide Transmission Lines

    PubMed Central

    Kowalski, Elizabeth J.; Shapiro, Michael A.; Temkin, Richard J.

    2014-01-01

    When using overmoded corrugated waveguide transmission lines for high power applications, it is necessary to control the mode content of the system. Ideally, overmoded corrugated transmission lines operate in the fundamental HE11 mode and provide low losses for long distances. Unwanted higher order modes (HOMs), particularly LP11 and HE12, are often excited in the experimental systems due to practical misalignments in the transmission line system. This paper discusses how the unwanted modes propagate along with the fundamental mode in the transmission line system by formulating an equation that relates the center of power offset and angle of propagation of a beam (for the HE11 and LP11 modes) or the waist size and phase front radius of curvature of a beam (for the HE11 and HE12 modes). By introducing two miter bend correctors into the transmission system—miter bends that have slightly angled or ellipsoidal mirrors—the HOMs can be precisely manipulated in the system. This technique can be used to eliminate small quantities of unwanted modes, thereby creating a nearly pure fundamental mode beam with minimal losses. Examples of these applications are calculated and show the theoretical conversion of up to 10% HOM content into the fundamental HE11 mode with minimal losses. PMID:25067859

  12. Multiplex Superconducting Transmission Line for green power consolidation on a Smart Grid

    NASA Astrophysics Data System (ADS)

    McIntyre, P.; Gerity, J.; Kellams, J.; Sattarov, A.

    2017-12-01

    A multiplex superconducting transmission line (MSTL) is being developed for applications requiring interconnection of multi-MW electric power generation among a number of locations. MSTL consists of a cluster of many 2- or 3-conductor transmission lines within a coaxial cryostat envelope. Each line operates autonomously, so that the interconnection of multiple power loads can be done in a failure-tolerant network. Specifics of the electrical, mechanical, and cryogenic design are presented. The consolidation of transformation and conditioning and the failure-tolerant interconnects have the potential to offer important benefit for the green energy components of a Smart Grid.

  13. Vacuum-Gauge Connection For Shipping Container

    NASA Technical Reports Server (NTRS)

    Henry, Robert H.

    1990-01-01

    External connector enables measurement of vacuum in stored part. Remote-readout connector added to shipping container and connected to thermo-couple vacuum gauge in vacuum-insulated cryogenic line packed in container. Enables monitoring of condition of vacuum without opening container.

  14. Advanced RF Sources Based on Novel Nonlinear Transmission Lines

    DTIC Science & Technology

    2015-01-26

    microwave (HPM) sources. It is also critical to thin film devices and integrated circuits, carbon nanotube based cathodes and interconnects, field emitters ... line model (TLM) in Fig. 6b. Our model is compared with TLM, shown in Fig. 7a. When the interface resistance rc is small, TLM becomes inaccurate...due to current crowding. Fig. 6. (a) Electrical contact including specific interfacial resistivity ρc, and (b) its transmission line model

  15. Transmission Electron Microscopy of Vacuum Sensitive, Radiation Sensitive, and Structurally Delicate Materials

    NASA Astrophysics Data System (ADS)

    Levin, Barnaby

    The transmission electron microscope (TEM) is a powerful tool for characterizing the nanoscale and atomic structure of materials, offering insights into their fundamental physical properties. However, TEM characterization requires very thin samples of material to be placed in a high vacuum environment, and exposed to electron radiation. The high vacuum will induce some materials to evaporate or sublimate, preventing them from being accurately characterized, radiation may damage the sample, causing mass loss, or altering its structure, and structurally delicate samples may collapse and break apart when they are thinned for TEM imaging. This dissertation discusses three different projects in which each of these three difficulties pose challenges to TEM characterization of samples. Firstly, we outline strategies for minimizing radiation damage when characterizing materials in TEM at atomic resolution. We consider types of radiation damage, such as vacancy enhanced displacement, that are not included in some previous discussions of beam damage, and we consider how to minimize damage when using new imaging techniques such as annular bright-field scanning TEM. Our methodology emphasizes the general principle that variation of both signal strength and damage cross section must be considered when choosing an experimental electron beam voltage to minimize damage. Secondly, we consider samples containing sulfur, which is prone to sublimation in high vacuum. TEM is routinely used to attempt to characterize the sulfur distribution in lithium-sulfur battery electrodes, but sublimation artifacts can give misleading results. We demonstrate that sulfur sublimation can be suppressed by using cryogenic TEM to characterize sulfur at very low temperatures, or by using the recently developed airSEM to characterize sulfur without exposing it to vacuum. Finally, we discuss the characterization of aging cadmium yellow paint from early 20th century art masterpieces. The binding medium

  16. JEDI Transmission Line Model | Jobs and Economic Development Impact Models

    Science.gov Websites

    , reasonable default values are provided. Individual projects may vary and when possible, project specific data Line Model rel. TL12.23.16. JEDI Transmission Line Model User Reference Guide Using MS Excel 2007 When ;High." Set the level to "Medium" or "Low" and then re-open the JEDI worksheet

  17. Transmission Line for 258 GHz Gyrotron DNP Spectrometry

    NASA Astrophysics Data System (ADS)

    Bogdashov, Alexandr A.; Belousov, Vladimir I.; Chirkov, Alexey V.; Denisov, Gregory G.; Korchagin, Vyacheslav V.; Kornishin, Sergey Yu.; Tai, Evgeny M.

    2011-06-01

    We describe the design and test results of the transmission line for liquid-state (LS) and solid-state (SS) DNP spectrometers with the second-harmonic 258.6 GHz gyrotron at the Institute of the Biophysical Chemistry Center of Goethe University (Frankfurt). The 13-meter line includes a mode converter, HE11 waveguides, 4 mitre bends, a variable polarizer-attenuator, directional couplers, a water-flow calorimeter and a mechanical switch. A microwave power of about 15 W was obtained in the pure HE11 mode at the spectrometer inputs.

  18. 75 FR 75170 - Minnkota Power Cooperative, Inc.: Bemidji to Grand Rapids 230 kV Transmission Line Project

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-02

    ... Grand Rapids 230 kV Transmission Line Project AGENCY: Rural Utilities Service, USDA. ACTION: Notice of... proposed Bemidji to Grand Rapids 230 kV Transmission Line Project (Project) in Beltrami, Hubbard, Itasca... financing to construct the 230 kilovolt (kV) transmission line between the Wilton Substation near Bemidji...

  19. Tunable Transmission-Line Metamaterials Mimicking Electromagnetically Induced Transparency

    NASA Astrophysics Data System (ADS)

    Feng, T. H.; Han, H. P.

    2016-11-01

    Tunable transmission-line (TL) metamaterials mimicking electromagnetically induced transparency (EIT) have been studied. Firstly, two types of tunable TL EIT-like metamaterial, based on the double split-ring resonator (DSRR) and single split-ring resonator (SSRR), were fabricated and their transmission properties carefully compared. The results showed that the transmittance maximum was almost invariable with shift of the transparency window for the tunable DSRR-based TL EIT-like metamaterial, but for the tunable SSRR-based TL EIT-like metamaterial, the transmittance maximum gradually diminished with shift of the transparency window toward the center of the absorption band. Moreover, the reason for these different transmission properties was explored, revealing that the reduction of the transmittance maximum of the transparency window for the tunable SSRR-based TL EIT-like metamaterial is mainly due to energy loss caused by the resistance of the loaded varactor diodes.

  20. Performance analysis of radiation cooled dc transmission lines for high power space systems

    NASA Technical Reports Server (NTRS)

    Schwarze, G. E.

    1985-01-01

    As space power levels increase to meet mission objectives and also as the transmission distance between power source and load increases, the mass, volume, power loss, and operating voltage and temperature become important system design considerations. This analysis develops the dependence of the specific mass and percent power loss on hte power and voltage levels, transmission distance, operating temperature and conductor material properties. Only radiation cooling is considered since the transmission line is assumed to operate in a space environment. The results show that the limiting conditions for achieving low specific mass, percent power loss, and volume for a space-type dc transmission line are the permissible transmission voltage and operating temperature. Other means to achieve low specific mass include the judicious choice of conductor materials. The results of this analysis should be immediately applicable to power system trade-off studies including comparisons with ac transmission systems.

  1. B1 field-insensitive transformers for RF-safe transmission lines.

    PubMed

    Krafft, Axel; Müller, Sven; Umathum, Reiner; Semmler, Wolfhard; Bock, Michael

    2006-11-01

    Integration of transformers into transmission lines suppresses radiofrequency (RF)-induced heating. New figure-of-eight-shaped transformer coils are compared to conventional loop transformer coils to assess their signal transmission properties and safety profile. The transmission properties of figure-of-eight-shaped transformers were measured and compared to transformers with loop coils. Experiments to quantify the effect of decoupling from the B1 field of the MR system were conducted. Temperature measurements were performed to demonstrate the effective reduction of RF-induced heating. The transformers were investigated during active tracking experiments. Coupling to the B1 field was reduced by 18 dB over conventional loop-shaped transformer coils. MR images showed a significantly reduced artifact for the figure-of-eight- shaped coils generated by local flip-angle amplification. Comparable transmission properties were seen for both transformer types. Temperature measurements showed a maximal temperature increase of 30 K/3.5 K for an unsegmented/segmented cable. With a segmented transmission line a robotic assistance system could be successfully localized using active tracking. The figure-of-eight-shaped transformer design reduces both RF field coupling with the MR system and artifact sizes. Anatomical structure close to the figure-of-eight-shaped transformer may be less obscured as with loop-shaped transformers if these transformers are integrated into e.g. intravascular catheters.

  2. A distributed parameter model of transmission line transformer for high voltage nanosecond pulse generation

    NASA Astrophysics Data System (ADS)

    Li, Jiangtao; Zhao, Zheng; Li, Longjie; He, Jiaxin; Li, Chenjie; Wang, Yifeng; Su, Can

    2017-09-01

    A transmission line transformer has potential advantages for nanosecond pulse generation including excellent frequency response and no leakage inductance. The wave propagation process in a secondary mode line is indispensable due to an obvious inside transient electromagnetic transition in this scenario. The equivalent model of the transmission line transformer is crucial for predicting the output waveform and evaluating the effects of magnetic cores on output performance. However, traditional lumped parameter models are not sufficient for nanosecond pulse generation due to the natural neglect of wave propagations in secondary mode lines based on a lumped parameter assumption. In this paper, a distributed parameter model of transmission line transformer was established to investigate wave propagation in the secondary mode line and its influential factors through theoretical analysis and experimental verification. The wave propagation discontinuity in the secondary mode line induced by magnetic cores is emphasized. Characteristics of the magnetic core under a nanosecond pulse were obtained by experiments. Distribution and formation of the secondary mode current were determined for revealing essential wave propagation processes in secondary mode lines. The output waveform and efficiency were found to be affected dramatically by wave propagation discontinuity in secondary mode lines induced by magnetic cores. The proposed distributed parameter model was proved more suitable for nanosecond pulse generation in aspects of secondary mode current, output efficiency, and output waveform. In depth, comprehension of underlying mechanisms and a broader view of the working principle of the transmission line transformer for nanosecond pulse generation can be obtained through this research.

  3. A distributed parameter model of transmission line transformer for high voltage nanosecond pulse generation.

    PubMed

    Li, Jiangtao; Zhao, Zheng; Li, Longjie; He, Jiaxin; Li, Chenjie; Wang, Yifeng; Su, Can

    2017-09-01

    A transmission line transformer has potential advantages for nanosecond pulse generation including excellent frequency response and no leakage inductance. The wave propagation process in a secondary mode line is indispensable due to an obvious inside transient electromagnetic transition in this scenario. The equivalent model of the transmission line transformer is crucial for predicting the output waveform and evaluating the effects of magnetic cores on output performance. However, traditional lumped parameter models are not sufficient for nanosecond pulse generation due to the natural neglect of wave propagations in secondary mode lines based on a lumped parameter assumption. In this paper, a distributed parameter model of transmission line transformer was established to investigate wave propagation in the secondary mode line and its influential factors through theoretical analysis and experimental verification. The wave propagation discontinuity in the secondary mode line induced by magnetic cores is emphasized. Characteristics of the magnetic core under a nanosecond pulse were obtained by experiments. Distribution and formation of the secondary mode current were determined for revealing essential wave propagation processes in secondary mode lines. The output waveform and efficiency were found to be affected dramatically by wave propagation discontinuity in secondary mode lines induced by magnetic cores. The proposed distributed parameter model was proved more suitable for nanosecond pulse generation in aspects of secondary mode current, output efficiency, and output waveform. In depth, comprehension of underlying mechanisms and a broader view of the working principle of the transmission line transformer for nanosecond pulse generation can be obtained through this research.

  4. Multiwavelet packet entropy and its application in transmission line fault recognition and classification.

    PubMed

    Liu, Zhigang; Han, Zhiwei; Zhang, Yang; Zhang, Qiaoge

    2014-11-01

    Multiwavelets possess better properties than traditional wavelets. Multiwavelet packet transformation has more high-frequency information. Spectral entropy can be applied as an analysis index to the complexity or uncertainty of a signal. This paper tries to define four multiwavelet packet entropies to extract the features of different transmission line faults, and uses a radial basis function (RBF) neural network to recognize and classify 10 fault types of power transmission lines. First, the preprocessing and postprocessing problems of multiwavelets are presented. Shannon entropy and Tsallis entropy are introduced, and their difference is discussed. Second, multiwavelet packet energy entropy, time entropy, Shannon singular entropy, and Tsallis singular entropy are defined as the feature extraction methods of transmission line fault signals. Third, the plan of transmission line fault recognition using multiwavelet packet entropies and an RBF neural network is proposed. Finally, the experimental results show that the plan with the four multiwavelet packet energy entropies defined in this paper achieves better performance in fault recognition. The performance with SA4 (symmetric antisymmetric) multiwavelet packet Tsallis singular entropy is the best among the combinations of different multiwavelet packets and the four multiwavelet packet entropies.

  5. Theory and Circuit Model for Lossy Coaxial Transmission Line

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

    Genoni, T. C.; Anderson, C. N.; Clark, R. E.

    2017-04-01

    The theory of signal propagation in lossy coaxial transmission lines is revisited and new approximate analytic formulas for the line impedance and attenuation are derived. The accuracy of these formulas from DC to 100 GHz is demonstrated by comparison to numerical solutions of the exact field equations. Based on this analysis, a new circuit model is described which accurately reproduces the line response over the entire frequency range. Circuit model calculations are in excellent agreement with the numerical and analytic results, and with finite-difference-time-domain simulations which resolve the skindepths of the conducting walls.

  6. A method for modeling discontinuities in a microwave coaxial transmission line

    NASA Technical Reports Server (NTRS)

    Otoshi, T. Y.

    1992-01-01

    A method for modeling discontinuities in a coaxial transmission line is presented. The methodology involves the use of a nonlinear least-squares fit program to optimize the fit between theoretical data (from the model) and experimental data. When this method was applied to modeling discontinuities in a slightly damaged Galileo spacecraft S-band (2.295-GHz) antenna cable, excellent agreement between theory and experiment was obtained over a frequency range of 1.70-2.85 GHz. The same technique can be applied for diagnostics and locating unknown discontinuities in other types of microwave transmission lines, such as rectangular, circular, and beam waveguides.

  7. A method for modeling discontinuities in a microwave coaxial transmission line

    NASA Astrophysics Data System (ADS)

    Otoshi, T. Y.

    1992-08-01

    A method for modeling discontinuities in a coaxial transmission line is presented. The methodology involves the use of a nonlinear least-squares fit program to optimize the fit between theoretical data (from the model) and experimental data. When this method was applied to modeling discontinuities in a slightly damaged Galileo spacecraft S-band (2.295-GHz) antenna cable, excellent agreement between theory and experiment was obtained over a frequency range of 1.70-2.85 GHz. The same technique can be applied for diagnostics and locating unknown discontinuities in other types of microwave transmission lines, such as rectangular, circular, and beam waveguides.

  8. Development of a Converter-Based Transmission Line Emulator with Three-Phase Short-Circuit Fault Emulation Capability

    DOE PAGES

    Zhang, Shuoting; Liu, Bo; Zheng, Sheng; ...

    2018-01-01

    A transmission line emulator has been developed to flexibly represent interconnected ac lines under normal operating conditions in a voltage source converter (VSC)-based power system emulation platform. As the most serious short-circuit fault condition, the three-phase short-circuit fault emulation is essential for power system studies. Here, this paper proposes a model to realize a three-phase short-circuit fault emulation at different locations along a single transmission line or one of several parallel-connected transmission lines. At the same time, a combination method is proposed to eliminate the undesired transients caused by the current reference step changes while switching between the fault statemore » and the normal state. Experiment results verify the developed transmission line three-phase short-circuit fault emulation capability.« less

  9. Development of a Converter-Based Transmission Line Emulator with Three-Phase Short-Circuit Fault Emulation Capability

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

    Zhang, Shuoting; Liu, Bo; Zheng, Sheng

    A transmission line emulator has been developed to flexibly represent interconnected ac lines under normal operating conditions in a voltage source converter (VSC)-based power system emulation platform. As the most serious short-circuit fault condition, the three-phase short-circuit fault emulation is essential for power system studies. Here, this paper proposes a model to realize a three-phase short-circuit fault emulation at different locations along a single transmission line or one of several parallel-connected transmission lines. At the same time, a combination method is proposed to eliminate the undesired transients caused by the current reference step changes while switching between the fault statemore » and the normal state. Experiment results verify the developed transmission line three-phase short-circuit fault emulation capability.« less

  10. Magnetically insulated transmission line oscillator

    DOEpatents

    Bacon, L.D.; Ballard, W.P.; Clark, M.C.; Marder, B.M.

    1987-05-19

    A magnetically insulated transmission line oscillator employs self-generated magnetic fields to generate microwave energy. An anode of the oscillator includes slow-wave structures which are formed of a plurality of thin conductive vanes defining cavities therebetween, and a gap is formed between the anode and a cathode of the oscillator. In response to a pulsed voltage applied to the anode and cathode, self-generated magnetic fields are produced in a cross-field orientation with respect to the orientation of the electric field between the anode and the cathode. The cross-field magnetic fields insulate the flow of electrons in the gap and confine the flow of electrons within the gap. 11 figs.

  11. Chameleon's behavior of modulable nonlinear electrical transmission line

    NASA Astrophysics Data System (ADS)

    Togueu Motcheyo, A. B.; Tchinang Tchameu, J. D.; Fewo, S. I.; Tchawoua, C.; Kofane, T. C.

    2017-12-01

    We show that modulable discrete nonlinear transmission line can adopt Chameleon's behavior due to the fact that, without changing its appearance structure, it can become alternatively purely right or left handed line which is different to the composite one. Using a quasidiscrete approximation, we derive a nonlinear Schrödinger equation, that predicts accurately the carrier frequency threshold from the linear analysis. It appears that the increasing of the linear capacitor in parallel in the series branch induced the selectivity of the filter in the right-handed region while it increases band pass filter in the left-handed region. Numerical simulations of the nonlinear model confirm the forward wave in the right handed line and the backward wave in the left handed one.

  12. Spatial Resolution in Scanning Electron Microscopy and Scanning Transmission Electron Microscopy Without a Specimen Vacuum Chamber.

    PubMed

    Nguyen, Kayla X; Holtz, Megan E; Richmond-Decker, Justin; Muller, David A

    2016-08-01

    A long-standing goal of electron microscopy has been the high-resolution characterization of specimens in their native environment. However, electron optics require high vacuum to maintain an unscattered and focused probe, a challenge for specimens requiring atmospheric or liquid environments. Here, we use an electron-transparent window at the base of a scanning electron microscope's objective lens to separate column vacuum from the specimen, enabling imaging under ambient conditions, without a specimen vacuum chamber. We demonstrate in-air imaging of specimens at nanoscale resolution using backscattered scanning electron microscopy (airSEM) and scanning transmission electron microscopy. We explore resolution and contrast using Monte Carlo simulations and analytical models. We find that nanometer-scale resolution can be obtained at gas path lengths up to 400 μm, although contrast drops with increasing gas path length. As the electron-transparent window scatters considerably more than gas at our operating conditions, we observe that the densities and thicknesses of the electron-transparent window are the dominant limiting factors for image contrast at lower operating voltages. By enabling a variety of detector configurations, the airSEM is applicable to a wide range of environmental experiments including the imaging of hydrated biological specimens and in situ chemical and electrochemical processes.

  13. Spatial Resolution in Scanning Electron Microscopy and Scanning Transmission Electron Microscopy Without a Specimen Vacuum Chamber

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

    Nguyen, Kayla X.; Holtz, Megan E.; Richmond-Decker, Justin

    2016-07-25

    Abstract A long-standing goal of electron microscopy has been the high-resolution characterization of specimens in their native environment. However, electron optics require high vacuum to maintain an unscattered and focused probe, a challenge for specimens requiring atmospheric or liquid environments. Here, we use an electron-transparent window at the base of a scanning electron microscope’s objective lens to separate column vacuum from the specimen, enabling imaging under ambient conditions, without a specimen vacuum chamber. We demonstrate in-air imaging of specimens at nanoscale resolution using backscattered scanning electron microscopy (airSEM) and scanning transmission electron microscopy. We explore resolution and contrast using Montemore » Carlo simulations and analytical models. We find that nanometer-scale resolution can be obtained at gas path lengths up to 400μm, although contrast drops with increasing gas path length. As the electron-transparent window scatters considerably more than gas at our operating conditions, we observe that the densities and thicknesses of the electron-transparent window are the dominant limiting factors for image contrast at lower operating voltages. By enabling a variety of detector configurations, the airSEM is applicable to a wide range of environmental experiments including the imaging of hydrated biological specimens andin situchemical and electrochemical processes.« less

  14. Compact vacuum insulation

    DOEpatents

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

    1993-01-05

    An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially point'' or line'' contacts with the metal wall sheets. In the case of monolithic spacers that form line'' contacts, two such spacers with the line contacts running perpendicular to each other form effectively point'' contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included.

  15. Compact vacuum insulation

    DOEpatents

    Benson, David K.; Potter, Thomas F.

    1993-01-01

    An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially "point" or "line" contacts with the metal wall sheets. In the case of monolithic spacers that form "line" contacts, two such spacers with the line contacts running perpendicular to each other form effectively "point" contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included.

  16. Supplement Analysis for the Transmission System Vegetation Management Program FEIS (DOE/EIS-0285/SA-40) - Allston-Keeler 500 kV Transmission Line

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

    Hermeston, Mark W.

    2002-02-19

    Vegetation Management along the Allston-Keeler 500 kV Transmission Line ROW exclusive to BLM lands between 8/4 through 27/4. The proposed work will be accomplished in the indicated sections of the transmission line corridor with an average corridor width of 150 feet. BPA proposes to clear unwanted vegetation in the rights-of-ways and around tower structures that may impede the operation and maintenance of the subject transmission lines and access roads, including Reclaim and Danger Trees. The lands in this SA are administered by BLM. BPA plans to conduct vegetation control with the goal of removing tall growing vegetation that is currentlymore » or will soon be a hazard to the transmission line. BPA’s overall goal is to have low-growing plant communities along the rights-of-way to control the development of potentially threatening vegetation. All work will be executed in accordance with the National Electrical Safety Code and BPA standards. Work is to begin in March 2002. In accordance with a court injunction, no chemical treatment is planned on BLM lands.« less

  17. Grand Coulee - Bell 500-kV Transmission Line Project, Draft Environmental Impact Statement

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

    N /A

    2002-08-09

    BPA is proposing to construct a 500-kilovolt (kV) transmission line that would extend approximately 84 miles between the Grand Coulee 500-kV Switchyard, near Grand Coulee Dam, and the Bell Substation, in Mead just north of Spokane. The new line would cross portions of Douglas, Grant, Lincoln, and Spokane counties. In addition to the transmission line, new equipment would be installed at the substations at each end of the new line and at other facilities. The proposed action would remove an existing 115-kV transmission line and replace it with the new 500-kV line on existing right-of-way for most of its length.more » Additional right-of-way would be needed in the first 3.5 miles out of the Grand Coulee Switchyard to connect to the existing 115-kV right-of-way. Since the mid-1990s, the transmission path west of Spokane, called the West of Hatwai transmission pathway, has grown increasingly constrained. To date, BPA has been able to manage operation of the path through available operating practices, and customer needed have been met while maintaining the reliability of the path. however, in early 2001, operations showed that the amount of electricity that needs to flow from east to west along this path creates severe transmission congestion. Under these conditions, the system is at risk of overloads and violation of industry safety and reliability standards. The problem is particularly acute in the spring and summer months because of the large amount of power generated by dams east of the path. Large amounts of water cannot be spilled during that time in order for BPA to fulfill its obligation to protect threatened and endangered fish. The amount of power that needs to move through this area during these months at times could exceed the carrying capacity of the existing transmission lines. In additional capacity is not added, BPA will run a significant risk that it will not be able to continue to meet its contractual obligations to deliver power and maintain

  18. Mitigation of bird collisions with transmission lines: Final report

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

    Beaulaurier, D.L.

    1981-09-11

    In this study removal of overhead groundwires was evaluated as a technique for mitigating bird collisions with transmission lines. Groundwires were removed by BPA from a 500 kV double circuit line at Bybee Lake in Portland, Oregon. Earlier studies at these sites had documented small but measurable collision rates (i.e., No. collisions/No. flights) attributed primarily to collisions with groundwires. Observations of bird flights and searches for dead birds in the vicinity of the lines constituted the primary methods of data collection during pre- and post-removal studies. Field work was conducted from October 1980 through March 1981. A total of sevenmore » dead birds and eight feather spots were found after groundwire removal. Species found were green-winged teal, pintail, greater scaup, American wigeon, glaucous-winged gull, starling, red-winged blackbird and song sparrow. No collisions with transmission lines were observed. During pre-removal studies at these two sites, a total of 53 dead birds and 22 feather spots were found over two years of study. It was necessary to document flight intensity (No. flights/day) during pre- and post-removal studies, in order to determine if the number of dead birds found changed because of groundwire removal or simply because of changes in flight intensity. 41 refs., 18 figs., 22 tabs.« less

  19. A vacuum-sealed, gigawatt-class, repetitively pulsed high-power microwave source

    NASA Astrophysics Data System (ADS)

    Xun, Tao; Fan, Yu-wei; Yang, Han-wu; Zhang, Zi-cheng; Chen, Dong-qun; Zhang, Jian-de

    2017-06-01

    A compact L-band sealed-tube magnetically insulated transmission line oscillator (MILO) has been developed that does not require bulky external vacuum pump for repetitive operations. This device with a ceramic insulated vacuum interface, a carbon fiber array cathode, and non-evaporable getters has a base vacuum pressure in the low 10-6 Pa range. A dynamic 3-D Monte-Carlo model for the molecular flow movement and collision was setup for the MILO chamber. The pulse desorption, gas evolution, and pressure distribution were exactly simulated. In the 5 Hz repetition rate experiments, using a 600 kV diode voltage and 48 kA beam current, the average radiated microwave power for 25 shots is about 3.4 GW in 45 ns pulse duration. The maximum equilibrium pressure is below 4.0 × 10-2 Pa, and no pulse shortening limitations are observed during the repetitive test in the sealed-tube condition.

  20. Study on galloping behavior of iced eight bundle conductor transmission lines

    NASA Astrophysics Data System (ADS)

    Zhou, Linshu; Yan, Bo; Zhang, Liang; Zhou, Song

    2016-02-01

    Wind tunnel test was carried out to obtain the aerodynamic coefficients of an eight bundle conductor accreted with crescent-shaped ice. A user-defined cable element with torsional degree of freedom is developed in ABAQUS software to capture the torsional deformation of the iced conductors during galloping. By means of the user-defined cable element, different damping ratios in in-plane, out-of-plane and torsional directions of the conductors can be defined and the aerodynamic forces varying with their motion status can be exerted on the conductors conveniently when ABAQUS is used to simulate galloping of transmission lines. A wind tunnel test to model galloping of an iced eight bundle conductor segment was carried out, and the validity of the numerical simulation method is demonstrated by the agreement of the galloping orbit of the bundle conductor segment model recorded in the test and that by the numerical simulation. Furthermore, galloping behavior, including dynamic responses, galloping orbits, frequencies, vibration modes and amplitudes, of typical iced eight bundle conductor transmission lines in the cases of different span lengths, initial tensions in sub-conductors, wind velocities, angles of wind attack and damping ratios is studied, and the galloping behavior of the lines with internal resonance conditions is discussed. The obtained results may provide a fundamental tool for the development of anti-galloping techniques of eight bundle conductor transmission lines.

  1. Time-resolved magnetic spectrometer measurements of the SABRE positive polarity magnetically insulated transmission line voltage

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

    Menge, P.R.; Cuneo, M.E.; Hanson, D.L.

    A magnetic spectrometer has been fielded on the coaxial magnetically insulated transmission line (MITL) of the SABRE ten-cavity inductive voltage adder operated in positive polarity (6 MV, 300 kA, 50 ns). Located 1 m upstream from an extraction ion diode, this diagnostic is capable of measuring the SABRE voltage pulse with a 2 ns resolution. Ions (protons and carbon) from either a flashover or plasma gun source are accelerated from the inner anode across the gap to the outer cathode and into a drift tube terminated by the magnetic spectrometer. The magnetically deflected ions are recorded on up to sixteenmore » PIN diodes (diameter = 1 mm, thickness = 35 {mu}). The voltage waveform is produced from the time-of-flight information. Results confirm previous observations of a vacuum wave precursor separated from the magnetically insulated wave. Verification of upstream precursor erosion techniques are possible with this instrument. Measurements of peak voltage show good agreement with other time-integrated voltage diagnostics. Comparisons with theoretical voltage predictions derived from a flow impedance model of MITL behavior will be presented.« less

  2. Mid-infrared metasurface made of composite right/left-handed transmission-line

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

    Luo, Yi; Ying, Xiangxiao; Pu, Yang

    2016-06-06

    We report on the realization of a mid-infrared metasurface based on the concept of composite right/left-handed transmission-line. The metasurface consists of a three-layer metal-insulator-metal structure patterned into transmission-lines by electron-beam lithography. Angle-variable reflection spectroscopy measurements reveal resonant absorption features corresponding to both right- and left-handed propagations in the leaky-wave guided mode region. Material loss is shown to dominate the quality factor of the left-handed modes, while the radiative loss dominates the right-handed ones. The experimental results are in good agreement with full-wave numerical simulations and are explained with an equivalent circuit model.

  3. Efficient design of multituned transmission line NMR probes: the electrical engineering approach.

    PubMed

    Frydel, J A; Krzystyniak, M; Pienkowski, D; Pietrzak, M; de Sousa Amadeu, N; Ratajczyk, T; Idzik, K; Gutmann, T; Tietze, D; Voigt, S; Fenn, A; Limbach, H H; Buntkowsky, G

    2011-01-01

    Transmission line-based multi-channel solid state NMR probes have many advantages regarding the cost of construction, number of RF-channels, and achievable RF-power levels. Nevertheless, these probes are only rarely employed in solid state-NMR-labs, mainly owing to the difficult experimental determination of the necessary RF-parameters. Here, the efficient design of multi-channel solid state MAS-NMR probes employing transmission line theory and modern techniques of electrical engineering is presented. As technical realization a five-channel ((1)H, (31)P, (13)C, (2)H and (15)N) probe for operation at 7 Tesla is described. This very cost efficient design goal is a multi port single coil transmission line probe based on the design developed by Schaefer and McKay. The electrical performance of the probe is determined by measuring of Scattering matrix parameters (S-parameters) in particular input/output ports. These parameters are compared to the calculated parameters of the design employing the S-matrix formalism. It is shown that the S-matrix formalism provides an excellent tool for examination of transmission line probes and thus the tool for a rational design of these probes. On the other hand, the resulting design provides excellent electrical performance. From a point of view of Nuclear Magnetic Resonance (NMR), calibration spectra of particular ports (channels) are of great importance. The estimation of the π/2 pulses length for all five NMR channels is presented. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. Design of the ITER Electron Cyclotron Heating and Current Drive Waveguide Transmission Line

    NASA Astrophysics Data System (ADS)

    Bigelow, T. S.; Rasmussen, D. A.; Shapiro, M. A.; Sirigiri, J. R.; Temkin, R. J.; Grunloh, H.; Koliner, J.

    2007-11-01

    The ITER ECH transmission line system is designed to deliver the power, from twenty-four 1 MW 170 GHz gyrotrons and three 1 MW 127.5 GHz gyrotrons, to the equatorial and upper launchers. The performance requirements, initial design of components and layout between the gyrotrons and the launchers is underway. Similar 63.5 mm ID corrugated waveguide systems have been built and installed on several fusion experiments; however, none have operated at the high frequency and long-pulse required for ITER. Prototype components are being tested at low power to estimate ohmic and mode conversion losses. In order to develop and qualify the ITER components prior to procurement of the full set of 24 transmission lines, a 170 GHz high power test of a complete prototype transmission line is planned. Testing of the transmission line at 1-2 MW can be performed with a modest power (˜0.5 MW) tube with a low loss (10-20%) resonant ring configuration. A 140 GHz long pulse, 400 kW gyrotron will be used in the initial tests and a 170 GHz gyrotron will be used when it becomes available. Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the U.S. Dept. of Energy under contract DE-AC05-00OR22725.

  5. Superconducting transmission line particle detector

    DOEpatents

    Gray, K.E.

    1988-07-28

    A microvertex particle detector for use in a high energy physic collider including a plurality of parallel superconducting thin film strips separated from a superconducting ground plane by an insulating layer to form a plurality of superconducting waveguides. The microvertex particle detector indicates passage of a charged subatomic particle by measuring a voltage pulse measured across a superconducting waveguide caused by the transition of the superconducting thin film strip from a superconducting to a non- superconducting state in response to the passage of a charged particle. A plurality of superconducting thin film strips in two orthogonal planes plus the slow electromagnetic wave propagating in a superconducting transmission line are used to resolve N/sup 2/ ambiguity of charged particle events. 6 figs.

  6. Superconducting transmission line particle detector

    DOEpatents

    Gray, Kenneth E.

    1989-01-01

    A microvertex particle detector for use in a high energy physic collider including a plurality of parallel superconducting thin film strips separated from a superconducting ground plane by an insulating layer to form a plurality of superconducting waveguides. The microvertex particle detector indicates passage of a charged subatomic particle by measuring a voltage pulse measured across a superconducting waveguide caused by the transition of the superconducting thin film strip from a superconducting to a non-superconducting state in response to the passage of a charged particle. A plurality of superconducting thin film strips in two orthogonal planes plus the slow electromagnetic wave propogating in a superconducting transmission line are used to resolve N.sup.2 ambiguity of charged particle events.

  7. Superconducting transmission line particle detector

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

    Gray, K.E.

    A microvertex particle detector for use in a high energy physic collider including a plurality of parallel superconducting thin film strips separated from a superconducting ground plane by an insulating layer to form a plurality of superconducting waveguides. The microvertex particle detector indicates passage of a charged subatomic particle by measuring a voltage pulse measured across a superconducting waveguide caused by the transition of the superconducting thin film strip from a superconducting to a non- superconducting state in response to the passage of a charged particle. A plurality of superconducting thin film strips in two orthogonal planes plus the slowmore » electromagnetic wave propagating in a superconducting transmission line are used to resolve N/sup 2/ ambiguity of charged particle events. 6 figs.« less

  8. Multivariable Time Series Prediction for the Icing Process on Overhead Power Transmission Line

    PubMed Central

    Li, Peng; Zhao, Na; Zhou, Donghua; Cao, Min; Li, Jingjie; Shi, Xinling

    2014-01-01

    The design of monitoring and predictive alarm systems is necessary for successful overhead power transmission line icing. Given the characteristics of complexity, nonlinearity, and fitfulness in the line icing process, a model based on a multivariable time series is presented here to predict the icing load of a transmission line. In this model, the time effects of micrometeorology parameters for the icing process have been analyzed. The phase-space reconstruction theory and machine learning method were then applied to establish the prediction model, which fully utilized the history of multivariable time series data in local monitoring systems to represent the mapping relationship between icing load and micrometeorology factors. Relevant to the characteristic of fitfulness in line icing, the simulations were carried out during the same icing process or different process to test the model's prediction precision and robustness. According to the simulation results for the Tao-Luo-Xiong Transmission Line, this model demonstrates a good accuracy of prediction in different process, if the prediction length is less than two hours, and would be helpful for power grid departments when deciding to take action in advance to address potential icing disasters. PMID:25136653

  9. Transmission line component testing for the ITER Ion Cyclotron Heating and Current Drive System

    NASA Astrophysics Data System (ADS)

    Goulding, Richard; Bell, G. L.; Deibele, C. E.; McCarthy, M. P.; Rasmussen, D. A.; Swain, D. W.; Barber, G. C.; Barbier, C. N.; Cambell, I. H.; Moon, R. L.; Pesavento, P. V.; Fredd, E.; Greenough, N.; Kung, C.

    2014-10-01

    High power RF testing is underway to evaluate transmission line components for the ITER Ion Cyclotron Heating and Current Drive System. The transmission line has a characteristic impedance Z0 = 50 Ω and a nominal outer diameter of 305 mm. It is specified to carry up to 6 MW at VSWR = 1.5 for 3600 s pulses, with transient voltages up to 40 kV. The transmission line is actively cooled, with turbulent gas flow (N2) used to transfer heat from the inner to outer conductor, which is water cooled. High voltage and high current testing of components has been performed using resonant lines generating steady state voltages of 35 kV and transient voltages up to 60 kV. A resonant ring, which has operated with circulating power of 6 MW for 1 hr pulses, is being used to test high power, low VSWR operation. Components tested to date include gas barriers, straight sections of various lengths, and 90 degree elbows. Designs tested include gas barriers fabricated from quartz and aluminum nitride, and transmission lines with quartz and alumina inner conductor supports. The latest results will be presented. This manuscript has been authored by UT-Battelle, LLC, under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy.

  10. Modulational Instability in a Pair of Non-identical Coupled Nonlinear Electrical Transmission Lines

    NASA Astrophysics Data System (ADS)

    Eric, Tala-Tebue; Aurelien, Kenfack-Jiotsa; Marius Hervé, Tatchou-Ntemfack; Timoléon Crépin, Kofané

    2013-07-01

    In this work, we investigate the dynamics of modulated waves non-identical coupled nonlinear transmission lines. Traditional methods for avoiding mode mixing in identical coupled nonlinear electrical lines consist of adding the same number of linear inductors in each branch. Adding linear inductors in a single line leads to asymmetric coupled nonlinear electrical transmission lines which propagate the signal and the mode mixing. On one hand, the difference between the two lines induced the fission for only one mode of propagation. This fission is influenced by the amplitude of the signal and the amount of the input energy as well; it also narrows the width of the input pulse soliton, leading to a possible increasing of the bit rate. On the other hand, the dissymmetry of the two lines converts the network into a good amplifier for the ω_ mode which corresponds to the regime admitting low frequencies.

  11. Normal modes of a superconducting transmission-line resonator with embedded lumped element circuit components

    NASA Astrophysics Data System (ADS)

    Mortensen, Henrik Lund; Mølmer, Klaus; Andersen, Christian Kraglund

    2016-11-01

    We present a method to identify the coupled, normal modes of a superconducting transmission line with an embedded lumped element circuit. We evaluate the effective transmission-line nonlinearities in the case of Kerr-like Josephson interactions in the circuit and in the case where the embedded circuit constitutes a qubit degree of freedom, which is Rabi coupled to the field in the transmission line. Our theory quantitatively accounts for the very high and positive Kerr nonlinearities observed in a recent experiment [M. Rehák, P. Neilinger, M. Grajcar, G. Oelsner, U. Hübner, E. Il'ichev, and H.-G. Meyer, Appl. Phys. Lett. 104, 162604 (2014), 10.1063/1.4873719], and we can evaluate the accomplishments of modified versions of the experimental circuit.

  12. Earth-ionosphere transmission line model for an impulsive geomagnetic disturbance at the dayside geomagnetic equator

    NASA Astrophysics Data System (ADS)

    Kikuchi, T.

    2004-12-01

    The near instantaneous onset of a geomagnetic impulse such as the preliminary reverse impulse (PRI) of the geomagnetic sudden commencement at high latitude and at the dayside geomagnetic equator has been explained by means of the TM0 mode waves in the Earth-ionosphere waveguide (Kikuchi and Araki, J. Atmosph. Terrest. Phys., 41, 927-936, 1979). There is, on the other hand, a time lag of the order of 10 sec in the peak amplitude of the magnetic impulse at the dayside equator. To explain these two temporal aspects, we examine transmission of the TM0 mode in a finite-length Earth-ionosphere transmission line composed of a finitely conducting ionosphere and the perfectly conducting Earth, with a fixed electric potential at one end and null potential at the other end of the transmission line, corresponding to the foot of a field-aligned current on the dawn- or dusk-side in the polar cap and middle point on the noon-midnight meridian at low latitude, respectively. Successive transmission and reflection in the bounded transmission line lead to that the ionospheric currents start to grow instantaneously, but reach a steady state with a relaxation time proportional to the length of the transmission line and the ionospheric conductivity. The relaxation time is of the order of 10 sec when we give high conductivity applicable to the equatorial ionosphere, which matches the observed time lag in the peak amplitude of the equatorial geomagnetic impulse. Consequently, the TM0 mode in the finite-length Earth-ionosphere transmission line explains both the instantaneous onset and time lag in the peak amplitude of the geomagnetic impulse at the dayside geomagnetic equator.

  13. A planar transmission-line sensor for measuring the microwave permittivity of liquid and semisolid biological materials

    USDA-ARS?s Scientific Manuscript database

    A planar transmission-line configuration for rapid, nondestructive, wideband permittivity measurements of liquid and semisolid materials at microwave frequencies is described. The transmission-line propagation constant of the proposed configuration is determined with the multiline technique from sca...

  14. Data-Mining-Based Intelligent Differential Relaying for Transmission Lines Including UPFC and Wind Farms.

    PubMed

    Jena, Manas Kumar; Samantaray, Subhransu Ranjan

    2016-01-01

    This paper presents a data-mining-based intelligent differential relaying scheme for transmission lines, including flexible ac transmission system device, such as unified power flow controller (UPFC) and wind farms. Initially, the current and voltage signals are processed through extended Kalman filter phasor measurement unit for phasor estimation, and 21 potential features are computed at both ends of the line. Once the features are extracted at both ends, the corresponding differential features are derived. These differential features are fed to a data-mining model known as decision tree (DT) to provide the final relaying decision. The proposed technique has been extensively tested for single-circuit transmission line, including UPFC and wind farms with in-feed, double-circuit line with UPFC on one line and wind farm as one of the substations with wide variations in operating parameters. The test results obtained from simulation as well as in real-time digital simulator testing indicate that the DT-based intelligent differential relaying scheme is highly reliable and accurate with a response time of 2.25 cycles from the fault inception.

  15. The relationship between residential proximity to extremely low frequency power transmission lines and adverse birth outcomes.

    PubMed

    Auger, Nathalie; Joseph, Dominique; Goneau, Marc; Daniel, Mark

    2011-01-01

    Occupational exposure to electromagnetic fields has been linked to adverse birth outcomes. This study evaluated whether maternal residential proximity to power transmission lines was associated with adverse birth outcomes. Live singleton births in the Montréal and Québec census metropolitan areas from 1990 to 2004 were extracted from the Québec birth file (N=707,215). Proximity was defined as residing within 400 m of a transmission line. Generalised estimating equations were used to evaluate associations between residential proximity to transmission lines and preterm birth (PTB), low birth weight (LBW), small-for-gestational age (SGA) birth and infant sex, accounting for maternal age, education, marital status, ethnicity, parity, period of birth, and neighbourhood median household income. There was no association between residential proximity to transmission lines and PTB, LBW and infant sex in unadjusted and adjusted models. A lower likelihood of SGA birth was present for some distance categories (eg, adjusted OR 0.88, 95% CI 0.81 to 0.95 for 50-75 m relative to ≥400 m). Residential proximity to transmission lines is not associated with adverse births outcomes.

  16. Design optimization of RF lines in vacuum environment for the MITICA experiment

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

    De Muri, Michela, E-mail: michela.demuri@igi.cnr.it; Consorzio RFX, Corso Stati Uniti, 4, I-35127 Padova; Pavei, Mauro

    This contribution regards the Radio Frequency (RF) transmission line of the Megavolt ITER Injector and Concept Advancement (MITICA) experiment. The original design considered copper coaxial lines of 1″ 5/8, but thermal simulations under operating conditions showed maximum temperatures of the lines at regime not compatible with the prescription of the component manufacturer. Hence, an optimization of the design was necessary. Enhancing thermal radiation and increasing the conductor size were considered for design optimization: thermal analyses were carried out to calculate the temperature of MITICA RF lines during operation, as a function of the emissivity value and of other geometrical parameters.more » Five coating products to increase the conductor surface emissivity were tested, measuring the outgassing behavior of the selected products and the obtained emissivity values.« less

  17. Development of bacterial biofilms in dairy processing lines.

    PubMed

    Austin, J W; Bergeron, G

    1995-08-01

    Adherence of bacteria to various milk contact sites was examined by scanning electron microscopy and transmission electron microscopy. New gaskets, endcaps, vacuum breaker plugs and pipeline inserts were installed in different areas in lines carrying either raw or pasteurized milk, and a routine schedule of cleaning-in-place and sanitizing was followed. Removed cleaned and sanitized gaskets were processed for scanning or transmission electron microscopy. Adherent bacteria were observed on the sides of gaskets removed from both pasteurized and raw milk lines. Some areas of Buna-n gaskets were colonized with a confluent layer of bacterial cells surrounded by an extensive amorphous matrix, while other areas of Buna-n gaskets showed a diffuse adherence over large areas of the surface. Most of the bacteria attached to polytetrafluoroethylene (PTFE or Teflon) gaskets were found in crevices created by insertion of the gasket into the pipeline. Examination of stainless steel endcaps, pipeline inserts, and PTFE vacuum breaker plugs did not reveal the presence of adherent bacteria. The results of this study indicate that biofilms developed on the sides of gaskets in spite of cleaning-in-place procedures. These biofilms may be a source of post-pasteurization contamination.

  18. 33 CFR 165.T01-0992 - Safety Zone; repair of high voltage transmission lines to Logan International Airport; Saugus...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... voltage transmission lines to Logan International Airport; Saugus River, Saugus, MA. 165.T01-0992 Section... high voltage transmission lines to Logan International Airport; Saugus River, Saugus, MA. (a) General... high voltage transmission lines to Logan International Airport; Saugus River, Saugus, MA. (i) All...

  19. Superconducting transmission line particle detector

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

    Gray, K.E.

    This paper describes a microvertex particle detector for use in a high energy physic collider including a plurality of parallel superconducting thin film strips separated from a superconducting ground plane by an insulating layer to form a plurality of superconducting waveguides. The microvertex particle detector indicates passage of a charged subatomic particle by measuring a voltage pulse measured across a superconducting waveguide caused by the transition of the superconducting thin film strip from a superconducting to a non-superconducting state in response to the passage of a charged particle. A plurality of superconducting thin film strips in two orthogonal planes plusmore » the slow electromagnetic wave propogating in a superconducting transmission line are used to resolve N{sup 2} ambiguity of charged particle events.« less

  20. 76 FR 19744 - Final Tropic to Hatch 138 kV Transmission Line Project Environmental Impact Statement and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-08

    ... DEPARTMENT OF AGRICULTURE Forest Service Final Tropic to Hatch 138 kV Transmission Line Project..., has prepared a Final Environmental Impact Statement (FEIS) for the Tropic to Hatch 138 kV Transmission.... ADDRESSES: Copies of the Tropic to Hatch 138 kV Transmission Line Project FEIS/PMPA for the Grand Staircase...

  1. Development of an accurate transmission line fault locator using the global positioning system satellites

    NASA Technical Reports Server (NTRS)

    Lee, Harry

    1994-01-01

    A highly accurate transmission line fault locator based on the traveling-wave principle was developed and successfully operated within B.C. Hydro. A transmission line fault produces a fast-risetime traveling wave at the fault point which propagates along the transmission line. This fault locator system consists of traveling wave detectors located at key substations which detect and time tag the leading edge of the fault-generated traveling wave as if passes through. A master station gathers the time-tagged information from the remote detectors and determines the location of the fault. Precise time is a key element to the success of this system. This fault locator system derives its timing from the Global Positioning System (GPS) satellites. System tests confirmed the accuracy of locating faults to within the design objective of +/-300 meters.

  2. PennsylvaniaNew Jersey Interconnection Bushkill to Roseland Transmission Line, From Roseland ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Pennsylvania-New Jersey Interconnection Bushkill to Roseland Transmission Line, From Roseland Borough, Essex County, through Morris County and Sussex County to Hardwick Township, Warren County, Roseland, Essex County, NJ

  3. 49 CFR 192.717 - Transmission lines: Permanent field repair of leaks.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... encirclement welded split sleeve of appropriate design, unless the transmission line is joined by mechanical... method that reliable engineering tests and analyses show can permanently restore the serviceability of...

  4. 49 CFR 192.717 - Transmission lines: Permanent field repair of leaks.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... encirclement welded split sleeve of appropriate design, unless the transmission line is joined by mechanical... method that reliable engineering tests and analyses show can permanently restore the serviceability of...

  5. 49 CFR 192.717 - Transmission lines: Permanent field repair of leaks.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... encirclement welded split sleeve of appropriate design, unless the transmission line is joined by mechanical... method that reliable engineering tests and analyses show can permanently restore the serviceability of...

  6. 49 CFR 192.717 - Transmission lines: Permanent field repair of leaks.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... encirclement welded split sleeve of appropriate design, unless the transmission line is joined by mechanical... method that reliable engineering tests and analyses show can permanently restore the serviceability of...

  7. 78 FR 76140 - Extension of Public Comment Period for the Champlain Hudson Power Express Transmission Line...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-16

    ... Transmission Line Project Draft Environmental Impact Statement AGENCY: Department of Energy. ACTION: Extension... comment period for the Champlain Hudson Power Express Transmission Line Project Draft Environmental Impact Statement (DOE/EIS-0447). The Draft EIS evaluates the environmental impacts of DOE's proposed Federal action...

  8. Compact vacuum insulation embodiments

    DOEpatents

    Benson, David K.; Potter, Thomas F.

    1992-01-01

    An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially "point" or "line" contacts with the metal wall sheets. In the case of monolithic spacers that form "line" contacts, two such spacers with the line contacts running perpendicular to each other form effectively "point" contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included.

  9. Dependence of NMR noise line shapes on tuning, matching, and transmission line properties

    PubMed Central

    Bendet-Taicher, Eli; Müller, Norbert; Jerschow, Alexej

    2014-01-01

    The tuning and matching conditions of rf circuits, as well as the properties of the transmission lines connecting these to the preamplifier, have direct consequences for NMR probe sensitivity and as for the optimum delivery of rf power to the sample. In addition, tuning/matching conditions influence radiation damping effects, which manifest themselves as fast signal flip-back and line broadening effects, and can lead to concentration-dependent frequency shifts. Previous studies have also shown that the appearance of spin-noise and absorbed circuit noise signals heavily depended on tuning settings. Consequently, all these phenomena are linked together. The mutual connections and interdependences of these effects are highlighted and reviewed here. PMID:25505374

  10. Two-dimensional solitary waves and periodic waves on coupled nonlinear electrical transmission lines

    NASA Astrophysics Data System (ADS)

    Wang, Heng; Zheng, Shuhua

    2017-06-01

    By using the dynamical system approach, the exact travelling wave solutions for a system of coupled nonlinear electrical transmission lines are studied. Based on this method, the bifurcations of phase portraits of a dynamical system are given. The two-dimensional solitary wave solutions and periodic wave solutions on coupled nonlinear transmission lines are obtained. With the aid of Maple, the numerical simulations are conducted for solitary wave solutions and periodic wave solutions to the model equation. The results presented in this paper improve upon previous studies.

  11. Development of Live-working Robot for Power Transmission Lines

    NASA Astrophysics Data System (ADS)

    Yan, Yu; Liu, Xiaqing; Ren, Chengxian; Li, Jinliang; Li, Hui

    2017-07-01

    Dream-I, the first reconfigurable live-working robot for power transmission lines successfully developed in China, has the functions of autonomous walking on lines and accurately positioning. This paper firstly described operation task and object of the robot; then designed a general platform, an insulator replacement end and a drainage plate bolt fastening end of the robot, presented a control system of the robot, and performed simulation analysis on operation plan of the robot; and finally completed electrical field withstand voltage tests in a high voltage hall as well as online test and trial on actual lines. Experimental results show that by replacing ends of manipulators, the robot can fulfill operation tasks of live replacement of suspension insulators and live drainage plate bolt fastening.

  12. 75 FR 3486 - Susquehanna to Roseland 500kV Transmission Line, Environmental Impact Statement, Delaware Water...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-21

    ... connection with the Susquehanna to Roseland 500kV Transmission Line. SUMMARY: Pursuant to National... Recreational River, and Appalachian National Scenic Trail, in connection with the proposed Susquehanna (Berwick... expand the width of the transmission line right-of-way beyond the Applicant's current holdings. The...

  13. 14 CFR 29.1433 - Vacuum systems.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Vacuum systems. 29.1433 Section 29.1433... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Equipment Miscellaneous Equipment § 29.1433 Vacuum systems. (a.... (b) Each vacuum air system line and fitting on the discharge side of the pump that might contain...

  14. Comparison of Transmission Line Methods for Surface Acoustic Wave Modeling

    NASA Technical Reports Server (NTRS)

    Wilson, William; Atkinson, Gary

    2009-01-01

    Surface Acoustic Wave (SAW) technology is low cost, rugged, lightweight, extremely low power and can be used to develop passive wireless sensors. For these reasons, NASA is investigating the use of SAW technology for Integrated Vehicle Health Monitoring (IVHM) of aerospace structures. To facilitate rapid prototyping of passive SAW sensors for aerospace applications, SAW models have been developed. This paper reports on the comparison of three methods of modeling SAWs. The three models are the Impulse Response Method (a first order model), and two second order matrix methods; the conventional matrix approach, and a modified matrix approach that is extended to include internal finger reflections. The second order models are based upon matrices that were originally developed for analyzing microwave circuits using transmission line theory. Results from the models are presented with measured data from devices. Keywords: Surface Acoustic Wave, SAW, transmission line models, Impulse Response Method.

  15. A Parametric Study of Nonlinear Seismic Response Analysis of Transmission Line Structures

    PubMed Central

    Wang, Yanming; Yi, Zhenhua

    2014-01-01

    A parametric study of nonlinear seismic response analysis of transmission line structures subjected to earthquake loading is studied in this paper. The transmission lines are modeled by cable element which accounts for the nonlinearity of the cable based on a real project. Nonuniform ground motions are generated using a stochastic approach based on random vibration analysis. The effects of multicomponent ground motions, correlations among multicomponent ground motions, wave travel, coherency loss, and local site on the responses of the cables are investigated using nonlinear time history analysis method, respectively. The results show the multicomponent seismic excitations should be considered, but the correlations among multicomponent ground motions could be neglected. The wave passage effect has a significant influence on the responses of the cables. The change of the degree of coherency loss has little influence on the response of the cables, but the responses of the cables are affected significantly by the effect of coherency loss. The responses of the cables change little with the degree of the difference of site condition changing. The effect of multicomponent ground motions, wave passage, coherency loss, and local site should be considered for the seismic design of the transmission line structures. PMID:25133215

  16. 14 CFR 25.1433 - Vacuum systems.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment Miscellaneous Equipment § 25.1433 Vacuum systems. There... discharge lines from the vacuum air pump when the delivery temperature of the air becomes unsafe. [Doc. No...

  17. Flow impedance in a uniform magnetically insulated transmission line

    NASA Astrophysics Data System (ADS)

    Mendel, C. W.; Seidel, D. B.

    1999-12-01

    In two recent publications [C. W. Mendel, Jr. and S. E. Rosenthal, Phys. of Plasmas 2, 1332 (1995), C. W. Mendel, Jr. and S. E. Rosenthal, Phys. of Plasmas 3, 4207 (1996)] relativistic electron flow in cylindrical magnetically insulated transmission lines was analyzed and modeled under the assumption of negligible electron pressure. The model allows power flow in these lines to be accurately calculated under most conditions. The model was developed for coaxial right circular cylindrical electrodes. It is shown here that the model applies equally well to arbitrary cylindrical systems, i.e., systems consisting of electrodes of arbitrary cross section.

  18. Vertical transmission of Orientia tsutsugamushi in two lines of naturally infected Leptotrombidium deliense (Acari: Trombiculidae).

    PubMed

    Frances, S P; Watcharapichat, P; Phulsuksombati, D

    2001-01-01

    Vertical transmission of Orientia tsutsugamushi (Hayashi), the etiologic agent for scrub typhus, was studied in two lines of naturally infected Leptotrombidium deliense Walch. In one line of mites originating from a single adult (V3M), the rate of filial transmission was 100% for the first two laboratory generations, but declined to 86.6% in the third laboratory generation. The vertical infection rate in this line of mites was 100% for the parental generation, but declined to 95.6% for the F1 generation and 88.6% for F2. The transmission of O. tsutsugamushi in another line of L. deliense (V3F) was less efficient than mites originating from V3M. In the initial laboratory generation of V3F a filial transmission rate of 100% was recorded. However, none of the F2 generation of this line transmitted rickettsiae to mice (Mus musculus L.), resulting in a filial transmission rate of 0%. Transmission of O. tsutsugamushi to mice by progeny from cohort larvae originally from the same adult (V3F) was also studied in the laboratory and these were found to be relatively poor transmitters of rickettsiae. The filial infection rate of F2 larvae was 60%, F3 was 88.8%, and F4 was 55.9%. The biology of infected L. deliense was studied and compared with uninfected mites reared under the same laboratory conditions. The results showed that infected female L. deliense laid approximately the same or more eggs as uninfected adults. The rate of development of the progeny of infected L. deliense was not significantly different from uninfected mites.

  19. High voltage gas insulated transmission line with continuous particle trapping

    DOEpatents

    Cookson, Alan H.; Dale, Steinar J.

    1983-01-01

    This invention provides a novel high voltage gas insulated transmission line utilizing insulating supports spaced at intervals with snap-in means for supporting a continuous trapping apparatus and said trapping apparatus having perforations and cutouts to facilitate trapping of contaminating particles and system flexibility.

  20. Transmission line design for a power distribution system at 20 kHz for aircraft

    NASA Technical Reports Server (NTRS)

    Zelby, L. W.; Mathes, J. B.; Shawver, J. W.

    1986-01-01

    A low inductance, low characteristic impedance transmission line was designed for a 20 kHz power distribution system. Several different conductor configurations were considered: strip lines, interdigitated metal ribbons, and standard insulated wires in multiwire configurations (circular and rectangular cylindrical arrangements). The final design was a rectangular arrangement of multiple wires of the same gauge with alternating polarities from wire to wire. This offered the lowest inductance per unit length (on the order of several nanohenries/meter) and the lowest characteristic impedance (on the order of one Ohm). Standard multipin connectors with gold-plated elements were recommended with this transmission line, the junction boxes to be internally connected with flat metal ribbons for low inductance, and the line to be constructed in sections of suitable length. Computer programs for the calculation of inductance of multiwire lines and of capacitances of strip lines were developed.

  1. Broadband complex permeability characterization of magnetic thin films using shorted microstrip transmission-line perturbation

    NASA Astrophysics Data System (ADS)

    Liu, Yan; Chen, Linfeng; Tan, C. Y.; Liu, H. J.; Ong, C. K.

    2005-06-01

    A brief review of the methods used for broadband complex permeability measurement of magnetic thin films up to microwave frequencies is given. In particular, the working principles of the transmission-line perturbation methods for the characterization of magnetic thin films are discussed, with emphasis on short-circuited planar transmission-line perturbation methods. The algorithms for calculating the complex permeability of magnetic thin films for short-circuited planar transmission-line perturbation methods are analyzed. A shorted microstrip line is designed and fabricated as a prototype measurement fixture. The structure of the microstrip fixture and the corresponding measurement procedure are discussed in detail. A piece of 340 nm thick FeTaN thin film deposited on Si substrate using sputtering method is characterized using the microstrip fixture. An improved technique for obtaining permeability by using a saturation magnetization field is demonstrated here, and the results fit well with the Landau-Lifchitz-Gilbert theory. Approaches to extending this method to other aspects in the investigation of magnetic thin film are also discussed.

  2. Compact vacuum insulation embodiments

    DOEpatents

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

    1992-04-28

    An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially point' or line' contacts with the metal wall sheets. In the case of monolithic spacers that form line' contacts, two such spacers with the line contacts running perpendicular to each other form effectively point' contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included. 26 figs.

  3. External synchronization of oscillating pulse edge on a transmission line with regularly spaced tunnel diodes.

    PubMed

    Narahara, Koichi; Misono, Masatoshi; Miyakawa, Kenji

    2013-01-01

    We investigate the external synchronization of the oscillating pulse edges developed in a transmission line periodically loaded with tunnel diodes (TDs), termed a TD line. It is observed that the pulse edge oscillates on a TD line when supplied by an appropriate voltage at the end of the line. We discuss how the pulse edge oscillates on a TD line and the properties of the external synchronization of the edge oscillation driven by a sinusoidal perturbation. By applying a phase-reduction scheme to the transmission equation of a TD line, we obtain the phase sensitivity, which satisfactory explains the measured spatial dependence of the locking range on the frequency. Moreover, we successfully detect the spatiotemporal behaviors of the edge oscillation by establishing synchronization with the sampling trigger of an oscilloscope.

  4. Vacuum system for the SAMURAI spectrometer

    NASA Astrophysics Data System (ADS)

    Shimizu, Y.; Otsu, H.; Kobayashi, T.; Kubo, T.; Motobayashi, T.; Sato, H.; Yoneda, K.

    2013-12-01

    The first commissioning experiment of the SAMURAI spectrometer and its beam line was performed in March, 2012. The vacuum system for the SAMURAI spectrometer includes its beam line and the SAMURAI vacuum chamber with the windows for detecting neutrons and charged particles. The window for neutrons was made of stainless steel with a thickness of 3 mm and was designed with a shape of partial cylinder to support itself against the atmospheric pressure. The window for charged particles was of the combination of Kevlar and Mylar with the thickness of 280 and 75 μm, respectively. The pressure in the vacuum system was at a few Pa throughout the commissioning experiment.

  5. Accelerator Vacuum Protection System

    NASA Astrophysics Data System (ADS)

    Barua, Pradip; Kothari, Ashok; Archunan, M.; Joshi, Rajan

    2012-11-01

    A new and elaborate automatic vacuum protection system using fast acting valve has been installed to avoid accidental venting of accelerator from experimental chamber side. To cover all the beam lines and to reduce the system cost, it has been installed at a common point from where all the seven beam lines originate. The signals are obtained by placing fast response pressure sensing gauges (HV SENSOR) near all the experimental stations. The closing time of the fast valve is 10 milli-second. The fast closing system protects only one vacuum line at a time. At IUAC, we have seven beam lines so one sensor was placed in each of the beam lines near experimental chamber and a multiplexer was incorporated into the fast closing system. At the time of experiment, the sensor of the active beam line is selected through the multiplexer and the Fast closing valve is interlocked with the selected sensor. As soon as the pressure sensor senses the pressure rise beyond a selected pressure, the signal is transferred and the fast valve closes within 10 to 12 millisecond.

  6. Calculation of voltages in electric power transmission lines during historic geomagnetic storms: An investigation using realistic earth impedances

    USGS Publications Warehouse

    Lucas, Greg M.; Love, Jeffrey J.; Kelbert, Anna

    2018-01-01

    Commonly, one-dimensional (1-D) Earth impedances have been used to calculate the voltages induced across electric power transmission lines during geomagnetic storms under the assumption that much of the three-dimensional structure of the Earth gets smoothed when integrating along power transmission lines. We calculate the voltage across power transmission lines in the mid-Atlantic region with both regional 1-D impedances and 64 empirical 3-D impedances obtained from a magnetotelluric survey. The use of 3-D impedances produces substantially more spatial variance in the calculated voltages, with the voltages being more than an order of magnitude different, both higher and lower, than the voltages calculated utilizing regional 1-D impedances. During the March 1989 geomagnetic storm 62 transmission lines exceed 100 V when utilizing empirical 3-D impedances, whereas 16 transmission lines exceed 100 V when utilizing regional 1-D impedances. This demonstrates the importance of using realistic impedances to understand and quantify the impact that a geomagnetic storm has on power grids.

  7. Ground Isolation Circuit for Isolating a Transmission Line from Ground Interference

    NASA Technical Reports Server (NTRS)

    Davidson, Craig A. (Inventor)

    1996-01-01

    This invention relates generally to a system for isolating ground interference from a transmission line, e.g., a ground isolation circuit for isolating a wideband transmission signal (such as a video signal) from ground by modulating the base signal on a carrier signal to permit the transmission signal to be isolated. In one embodiment, the circuit includes a pair of matched mixer circuits, each of which receives a carrier signal from the same oscillator circuit. The first mixer circuit also receives the baseband signal input, after appropriate conditioning, and modulates the baseband signal onto the carrier signal. In a preferred embodiment the carrier signal has a predetermined frequency which is at least two times the frequency of the baseband signal. The modulated signal (which can comprise an rf signal) is transmitted via an rf transmission line to the second mixer, which demodulates the rf signal to recover the baseband signal. Each port of the mixer connects to an isolation transformer to ensure isolation from ground interference. The circuit is considered to be of commercial value in that it can provide isolation between transmitting and receiving circuits, e.g., ground isolation for television circuits or high frequency transmitters, without the need for video transformers or optical isolators, thereby reducing the complexity, power consumption, and weight of the system.

  8. Bias-field controlled phasing and power combination of gyromagnetic nonlinear transmission lines

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

    Reale, D. V., E-mail: david.reale@ttu.edu; Bragg, J.-W. B.; Gonsalves, N. R.

    2014-05-15

    Gyromagnetic Nonlinear Transmission Lines (NLTLs) generate microwaves through the damped gyromagnetic precession of the magnetic moments in ferrimagnetic material, and are thus utilized as compact, solid-state, frequency agile, high power microwave (HPM) sources. The output frequency of a NLTL can be adjusted by control of the externally applied bias field and incident voltage pulse without physical alteration to the structure of the device. This property provides a frequency tuning capability not seen in many conventional e-beam based HPM sources. The NLTLs developed and tested are mesoband sources capable of generating MW power levels in the L, S, and C bandsmore » of the microwave spectrum. For an individual NLTL the output power at a given frequency is determined by several factors including the intrinsic properties of the ferrimagnetic material and the transmission line structure. Hence, if higher power levels are to be achieved, it is necessary to combine the outputs of multiple NLTLs. This can be accomplished in free space using antennas or in a transmission line via a power combiner. Using a bias-field controlled delay, a transient, high voltage, coaxial, three port, power combiner was designed and tested. Experimental results are compared with the results of a transient COMSOL simulation to evaluate combiner performance.« less

  9. Bias-field controlled phasing and power combination of gyromagnetic nonlinear transmission lines.

    PubMed

    Reale, D V; Bragg, J-W B; Gonsalves, N R; Johnson, J M; Neuber, A A; Dickens, J C; Mankowski, J J

    2014-05-01

    Gyromagnetic Nonlinear Transmission Lines (NLTLs) generate microwaves through the damped gyromagnetic precession of the magnetic moments in ferrimagnetic material, and are thus utilized as compact, solid-state, frequency agile, high power microwave (HPM) sources. The output frequency of a NLTL can be adjusted by control of the externally applied bias field and incident voltage pulse without physical alteration to the structure of the device. This property provides a frequency tuning capability not seen in many conventional e-beam based HPM sources. The NLTLs developed and tested are mesoband sources capable of generating MW power levels in the L, S, and C bands of the microwave spectrum. For an individual NLTL the output power at a given frequency is determined by several factors including the intrinsic properties of the ferrimagnetic material and the transmission line structure. Hence, if higher power levels are to be achieved, it is necessary to combine the outputs of multiple NLTLs. This can be accomplished in free space using antennas or in a transmission line via a power combiner. Using a bias-field controlled delay, a transient, high voltage, coaxial, three port, power combiner was designed and tested. Experimental results are compared with the results of a transient COMSOL simulation to evaluate combiner performance.

  10. Simulation study on transient electric shock characteristics of human body under high voltage ac transmission lines

    NASA Astrophysics Data System (ADS)

    Huang, Tao; Zou, Yanhui; Lv, Jianhong; Yang, Jinchun; Tao, Li; Zhou, Jianfei

    2017-09-01

    Human body under high-voltage AC transmission lines will produce a certain induced voltage due to the electrostatic induction. When the human body contacts with some grounded objects, the charges transfer from the body to the ground and produce contact current which may cause transient electric shock. Using CDEGS and ATP/EMTP, the paper proposes a method for quantitatively calculating the transient electric shock characteristics. It calculates the human body voltage, discharge current and discharge energy under certain 500kV compact-type transmission lines and predicts the corresponding human feelings. The results show that the average root value of discharge current is less than 10mA when the human body is under the 500kV compact-type transmission lines and the human body is overall safe if the transmission lines satisfy the relevant design specifications. It concludes that the electric field strength above the ground should be limited to 4kV/m through the residential area for the purpose of reducing the electromagnetic impact.

  11. On increasing the spectral efficiency and transmissivity in the data transmission channel on the spacecraft-ground tracking station line

    NASA Astrophysics Data System (ADS)

    Andrianov, M. N.; Kostenko, V. I.; Likhachev, S. F.

    2018-01-01

    The algorithms for achieving a practical increase in the rate of data transmission on the space-craft-ground tracking station line has been considered. This increase is achieved by applying spectral-effective modulation techniques, the technology of orthogonal frequency compression of signals using millimeterrange radio waves. The advantages and disadvantages of each of three algorithms have been revealed. A significant advantage of data transmission in the millimeter range has been indicated.

  12. Transmission competency of single-female Xiphinema index lines for Grapevine fanleaf virus.

    PubMed

    Demangeat, Gérard; Komar, Véronique; Van-Ghelder, Cyril; Voisin, Roger; Lemaire, Olivier; Esmenjaud, Daniel; Fuchs, Marc

    2010-04-01

    Grapevine fanleaf virus (GFLV) is vectored specifically from grapevine to grapevine by the ectoparasitic nematode Xiphinema index. Limited information is available on the vector competency of X. index populations from diverse geographical origins. We determined the transmissibility of two GFLV strains showing 4.6% amino acid divergence within their coat protein (e.g., strains F13 and GHu) by seven clonal lines of X. index developed from seven distinct populations from the Mediterranean basin (Cyprus, southern France, Israel, Italy, and Spain), northern France, and California. X. index lines derived from single adult females were produced on fig (Ficus carica) plants to obtain genetically homogenous aviruliferous clones. A comparative reproductive rate analysis on Vitis rupestris du Lot and V. vinifera cv. Cabernet Sauvignon showed significant differences among clones, with the single-female Cyprus line showing the highest rate (30-fold the initial population) and the Spain and California lines showing the lowest rate (10-fold increase), regardless of the grapevine genotype. However, there was no differential vector competency among the seven X. index lines for GFLV strains F13 and GHu. The implications of our findings for the dynamic of GFLV transmission in vineyards and screening of Vitis spp. for resistance to GFLV are discussed.

  13. Transmission line relay mis-operation detection based on time-synchronized field data

    DOE PAGES

    Esmaeilian, Ahad; Popovic, Tomo; Kezunovic, Mladen

    2015-05-04

    In this paper, a real-time tool to detect transmission line relay mis-operation is implemented. The tool uses time-synchronized measurements obtained from both ends of the line during disturbances. The proposed fault analysis tool comes into the picture only after the protective device has operated and tripped the line. The proposed methodology is able not only to detect, classify, and locate transmission line faults, but also to accurately confirm whether the line was tripped due to a mis-operation of protective relays. The analysis report includes either detailed description of the fault type and location or detection of relay mis-operation. As such,more » it can be a source of very useful information to support the system restoration. The focus of the paper is on the implementation requirements that allow practical application of the methodology, which is illustrated using the field data obtained the real power system. Testing and validation is done using the field data recorded by digital fault recorders and protective relays. The test data included several hundreds of event records corresponding to both relay mis-operations and actual faults. The discussion of results addresses various challenges encountered during the implementation and validation of the presented methodology.« less

  14. Optical transmission measurements for in-line monitoring of turbid oil-water emulsions

    NASA Astrophysics Data System (ADS)

    Metz, Philipp; Dopf, Katja; Aichholz, Markus; Riedel, Boris; Lemmer, Uli; Freudig, Barbara; Zimmermann, Clifton; Gerken, Martina

    2014-05-01

    For absorbing media the concentration may be calculated directly from the optical transmission following the logarithmic dependence given in the Lambert-Beer law. Due to multiple scattering events in oil-water emulsions (e.g. milk, cream, etc.), these exhibit a nonlinear relationship between the attenuation and the oil concentration. We demonstrate that for increasing oil content in oil-water emulsions the attenuation first increases, then levels out, and finally even decreases for a fat content of 60%. Single-wavelength optical transmission measurements are found to be well suited for the in-line monitoring of oil-water emulsions of fat contents below 20%, e.g., for the in-line fat content monitoring of milk. Using experiments and ray-tracing simulations we evaluate system optimization.

  15. Study of Corrosion Resistance Improvement by Metallic Coating for Overhead Transmission Line Conductor

    NASA Astrophysics Data System (ADS)

    Isozaki, Masanori; Adachi, Kouichi; Hita, Takanori; Asano, Yuji

    Applying anti-corrosion grease and aluminum clad steel (AC) wires to ACSR has adopted as general methods to prevent overhead transmission line conductors and/or wires from corrosion. However, there are some cases that ineffectiveness of those means are reported on some transmission lines passing through acid atmosphere in the vicinity of a factory exhausting acid smoke. The feature of the corrosion caused by acid atmosphere is to show a higher speed in its progressing as well known. As means against such acid corrosion, application of high purity aluminum, selective removal of inter-metallic compound in aluminum and plastic coating wires has been reported before, and each has both of advantage and disadvantage actually. In the former letter, we reported the new type of anti-corrosion grease that shows an excellent property against acid atmosphere as well as in a salty circumstance. Here presents a new type of anti-corrosion technology of applying high corrosion resistance aluminum alloy or zinc coatings on each component wires of a conductor that we succeed in developing through a serial study of anti-corrosion methods on overhead transmission lines.

  16. Displacement current phenomena in the magnetically insulated transmission lines of the refurbished Z accelerator

    NASA Astrophysics Data System (ADS)

    McBride, R. D.; Jennings, C. A.; Vesey, R. A.; Rochau, G. A.; Savage, M. E.; Stygar, W. A.; Cuneo, M. E.; Sinars, D. B.; Jones, M.; Lechien, K. R.; Lopez, M. R.; Moore, J. K.; Struve, K. W.; Wagoner, T. C.; Waisman, E. M.

    2010-12-01

    Experimental data is presented that illustrates important displacement current phenomena in the magnetically insulated transmission lines (MITLs) of the refurbished Z accelerator [D. V. Rose , Phys. Rev. ST Accel. Beams 13, 010402 (2010)PRABFM1098-440210.1103/PhysRevSTAB.13.010402]. Specifically, we show how displacement current in the MITLs causes significant differences between the accelerator current measured at the vacuum-insulator stack (at a radial position of about 1.6 m from the Z axis of symmetry) and the accelerator current measured at the load (at a radial position of about 6 cm from the Z axis of symmetry). The importance of accounting for these differences was first emphasized by Jennings et al. [C. A. Jennings , IEEE Trans. Plasma Sci. 38, 529 (2010)ITPSBD0093-381310.1109/TPS.2010.2042971], who calculated them using a full transmission-line-equivalent model of the four-level MITL system. However, in the data presented by Jennings et al., many of the interesting displacement current phenomena were obscured by parasitic current losses that occurred between the vacuum-insulator stack and the load (e.g., electron flow across the anode-cathode gap). By contrast, the data presented herein contain very little parasitic current loss, and thus for these low-loss experiments we are able to demonstrate that the differences between the current measured at the stack and the current measured at the load are due primarily to the displacement current that results from the shunt capacitance of the MITLs (about 8.41 nF total). Demonstrating this is important because displacement current is an energy storage mechanism, where energy is stored in the MITL electric fields and can later be used by the system. Thus, even for higher-loss experiments, the differences between the current measured at the stack and the current measured at the load are often largely due to energy storage and subsequent release, as opposed to being due solely to some combination of measurement

  17. Environmental Assessment and Finding of No Significant Impact: Curecanti-Lost Canyon 230-kV Transmission Line Reroute Project, Montrose County, Colorado

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

    N /A

    2000-03-20

    The Department of Energy (DOE), Western Area Power Administration (Western) is proposing to reroute a section of the Curecanti-Lost Canyon 230-kilovolt (kV) transmission line, in Montrose County, Colorado. A portion of the transmission line, situated 11 miles southeast of Montrose, Colorado, crosses Waterdog Peak, an area of significant geologic surface activity, which is causing the transmission line's lattice steel towers to shift. This increases stress to structure hardware and conductors, and poses a threat to the integrity of the transmission system. Western proposes to relocate the lattice steel towers and line to a more geologically stable area. The existing sectionmore » of transmission line and the proposed relocation route cross Bureau of Land Management and private land holdings.« less

  18. A Novel Method of Autonomous Inspection for Transmission Line based on Cable Inspection Robot LiDAR Data

    PubMed Central

    Qin, Xinyan; Wu, Gongping; Fan, Fei; Ye, Xuhui; Mei, Quanjie

    2018-01-01

    With the growth of the national economy, there is increasing demand for electricity, which forces transmission line corridors to become structurally complicated and extend to complex environments (e.g., mountains, forests). It is a great challenge to inspect transmission line in these regions. To address these difficulties, a novel method of autonomous inspection for transmission line is proposed based on cable inspection robot (CIR) LiDAR data, which mainly includes two steps: preliminary inspection and autonomous inspection. In preliminary inspection, the position and orientation system (POS) data is used for original point cloud dividing, ground point filtering, and structured partition. A hierarchical classification strategy is established to identify the classes and positions of the abnormal points. In autonomous inspection, CIR can autonomously reach the specified points through inspection planning. These inspection targets are imaged with PTZ (pan, tilt, zoom) cameras by coordinate transformation. The feasibility and effectiveness of the proposed method are verified by test site experiments and actual line experiments, respectively. The proposed method greatly reduces manpower and improves inspection accuracy, providing a theoretical basis for intelligent inspection of transmission lines in the future. PMID:29462865

  19. A multi-functional high voltage experiment apparatus for vacuum surface flashover switch research.

    PubMed

    Zeng, Bo; Su, Jian-cang; Cheng, Jie; Wu, Xiao-long; Li, Rui; Zhao, Liang; Fang, Jin-peng; Wang, Li-min

    2015-04-01

    A multifunctional high voltage apparatus for experimental researches on surface flashover switch and high voltage insulation in vacuum has been developed. The apparatus is composed of five parts: pulse generating unit, axial field unit, radial field unit, and two switch units. Microsecond damped ringing pulse with peak-to-peak voltage 800 kV or unipolar pulse with maximum voltage 830 kV is generated, forming transient axial or radial electrical field. Different pulse waveforms and field distributions make up six experimental configurations in all. Based on this apparatus, preliminary experiments on vacuum surface flashover switch with different flashover dielectric materials have been conducted in the axial field unit, and nanosecond pulse is generated in the radial field unit which makes a pulse transmission line in the experiment. Basic work parameters of this kind of switch such as lifetime, breakdown voltage are obtained.

  20. Coupling mid-infrared light from a photonic crystal waveguide to metallic transmission lines

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

    Blanco-Redondo, Andrea, E-mail: andrea.blanco@tecnalia.com, E-mail: r.hillenbrand@nanogune.eu; Dpto. Electronica y Telecom., E.T.S. Ingeniería Bilbao, UPV/EHU, Alda. Urquijo, 48103 Bilbao, Bizkaia; Sarriugarte, Paulo

    2014-01-06

    We propose and theoretically study a hybrid structure consisting of a photonic crystal waveguide (PhC-wg) and a two-wire metallic transmission line (TL), engineered for efficient transfer of mid-infrared (mid-IR) light between them. An efficiency of 32% is obtained for the coupling from the transverse magnetic (TM) photonic mode to the symmetric mode of the TL, with a predicted intensity enhancement factor of 53 at the transmission line surface. The strong coupling is explained by the small phase velocity mismatch and sufficient spatial overlapping between the modes. This hybrid structure could find applications in highly integrated mid-IR photonic-plasmonic devices for biologicalmore » and gas sensing, among others.« less

  1. Hybrid particle traps and conditioning procedure for gas insulated transmission lines

    DOEpatents

    Dale, Steinar J.; Cookson, Alan H.

    1982-01-01

    A gas insulated transmission line includes an outer sheath, an inner condor within the outer sheath, insulating supports supporting the inner conductor within the outer sheath, and an insulating gas electrically insulating the inner conductor from the outer sheath. An apertured particle trapping ring is disposed within the outer sheath, and the trapping ring has a pair of dielectric members secured at each longitudinal end thereof, with the dielectric members extending outwardly from the trapping ring along an arc. A support sheet having an adhesive coating thereon is secured to the trapping ring and disposed on the outer sheath within the low field region formed between the trapping ring and the outer sheath. A conditioning method used to condition the transmission line prior to activation in service comprises applying an AC voltage to the inner conductor in a plurality of voltage-time steps, with the voltage-time steps increasing in voltage magnitude while decreasing in time duration.

  2. Big George to Carter Mountain 115-kV transmission line project, Park and Hot Springs Counties, Wyoming. Environmental Assessment

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

    Not Available

    1994-02-01

    The Western Area Power Administration (Western) is proposing to rebuild, operate, and maintain a 115-kilovolt (kV) transmission line between the Big George and Carter Mountain Substations in northwest Wyoming (Park and Hot Springs Counties). This environmental assessment (EA) was prepared in compliance with the National Environmental Policy Act (NEPA) and the regulations of the Council on Environmental Quality (CEQ) and the Department of Energy (DOE). The existing Big George to Carter Mountain 69-kV transmission line was constructed in 1941 by the US Department of Interior, Bureau of Reclamation, with 1/0 copper conductor on wood-pole H-frame structures without an overhead groundmore » wire. The line should be replaced because of the deteriorated condition of the wood-pole H-frame structures. Because the line lacks an overhead ground wire, it is subject to numerous outages caused by lightning. The line will be 54 years old in 1995, which is the target date for line replacement. The normal service life of a wood-pole line is 45 years. Under the No Action Alternative, no new transmission lines would be built in the project area. The existing 69-kV transmission line would continue to operate with routine maintenance, with no provisions made for replacement.« less

  3. Fiber Bragg grating sensor for fault detection in high voltage overhead transmission lines

    NASA Astrophysics Data System (ADS)

    Moghadas, Amin

    2011-12-01

    A fiber optic based sensor capable of fault detection in both radial and network overhead transmission power line systems is investigated. Bragg wavelength shift is used to measure the fault current and detect fault in power systems. Magnetic fields generated by currents in the overhead transmission lines cause a strain in magnetostrictive material which is then detected by fiber Bragg grating (FBG) sensors. The Fiber Bragg interrogator senses the reflected FBG signals, and the Bragg wavelength shift is calculated and the signals are processed. A broadband light source in the control room scans the shift in the reflected signals. Any surge in the magnetic field relates to an increased fault current at a certain location. Also, fault location can be precisely defined with an artificial neural network (ANN) algorithm. This algorithm can be easily coordinated with other protective devices. It is shown that the faults in the overhead transmission line cause a detectable wavelength shift on the reflected signal of FBG sensors and can be used to detect and classify different kind of faults. The proposed method has been extensively tested by simulation and results confirm that the proposed scheme is able to detect different kinds of fault in both radial and network system.

  4. Fiber Bragg Grating Sensor for Fault Detection in Radial and Network Transmission Lines

    PubMed Central

    Moghadas, Amin A.; Shadaram, Mehdi

    2010-01-01

    In this paper, a fiber optic based sensor capable of fault detection in both radial and network overhead transmission power line systems is investigated. Bragg wavelength shift is used to measure the fault current and detect fault in power systems. Magnetic fields generated by currents in the overhead transmission lines cause a strain in magnetostrictive material which is then detected by Fiber Bragg Grating (FBG). The Fiber Bragg interrogator senses the reflected FBG signals, and the Bragg wavelength shift is calculated and the signals are processed. A broadband light source in the control room scans the shift in the reflected signal. Any surge in the magnetic field relates to an increased fault current at a certain location. Also, fault location can be precisely defined with an artificial neural network (ANN) algorithm. This algorithm can be easily coordinated with other protective devices. It is shown that the faults in the overhead transmission line cause a detectable wavelength shift on the reflected signal of FBG and can be used to detect and classify different kind of faults. The proposed method has been extensively tested by simulation and results confirm that the proposed scheme is able to detect different kinds of fault in both radial and network system. PMID:22163416

  5. Coupled Transmission Line Based Slow Wave Structures for Traveling Wave Tubes Applications

    NASA Astrophysics Data System (ADS)

    Zuboraj, Md. Rashedul Alam

    High power microwave devices especially Traveling Wave Tubes (TWTs) and Backward Wave Oscillators (BWOs) are largely dependent on Slow Wave Structures for efficient beam to RF coupling. In this work, a novel approach of analyzing SWSs is proposed and investigated. Specifically, a rigorous study of helical geometries is carried out and a novel SWS "Half-Ring-Helix" is designed. This Half-Ring-Helix circuit achieves 27% miniaturization and delivers 10dB more gain than conventional helices. A generalization of the helix structures is also proposed in the form of Coupled Transmission Line (CTL). It is demonstrated that control of coupling among the CTLs leads to new propagation properties. With this in mind, a novel geometry referred to as "Curved Ring-Bar" is introduced. This geometry is shown to deliver 1MW power across a 33% bandwidth. Notably, this is the first demonstration of MW power TWT across large bandwidth. The CTL is further expanded to enable engineered propagation characteristics. This is done by introducing CTLs having non-identical transmission lines and CTLs with as many as four transmission lines in the same slow wave structure circuit. These non-identical CTLs are demonstrated to generate fourth order dispersion curves. Building on the property of CTLs, a `butterfly' slow wave structure is developed and demonstrated to provide degenerate band edge (DBE) mode. This mode are known to provide large feld enhancement that can be exploited to design high power backward wave oscillators.

  6. Political efficacy and familiarity as predictors of attitudes towards electric transmission lines in the United States

    DOE PAGES

    Joe, Jeffrey C.; Hendrickson, Kelsie; Wong, Maria; ...

    2016-05-18

    Public opposition to the construction (i.e., siting) of new high voltage overhead transmission lines is not a new or isolated phenomenon. Past research has posited a variety of reasons, applied general theories, and has provided empirical evidence to explain public opposition. The existing literature, while clarifying many elements of the issue, does not yet fully explain the complexities underlying this public opposition phenomenon. As a result, the current study demonstrated how two overlooked factors, people’s sense of political efficacy and their familiarity (i.e., prior exposure) with transmission lines, explained attitudes of support and opposition to siting new power lines.

  7. Political efficacy and familiarity as predictors of attitudes towards electric transmission lines in the United States

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

    Joe, Jeffrey C.; Hendrickson, Kelsie; Wong, Maria

    Public opposition to the construction (i.e., siting) of new high voltage overhead transmission lines is not a new or isolated phenomenon. Past research has posited a variety of reasons, applied general theories, and has provided empirical evidence to explain public opposition. The existing literature, while clarifying many elements of the issue, does not yet fully explain the complexities underlying this public opposition phenomenon. As a result, the current study demonstrated how two overlooked factors, people’s sense of political efficacy and their familiarity (i.e., prior exposure) with transmission lines, explained attitudes of support and opposition to siting new power lines.

  8. Study of a phase-to-ground fault on a 400 kV overhead transmission line

    NASA Astrophysics Data System (ADS)

    Iagăr, A.; Popa, G. N.; Diniş, C. M.

    2018-01-01

    Power utilities need to supply their consumers at high power quality level. Because the faults that occur on High-Voltage and Extra-High-Voltage transmission lines can cause serious damages in underlying transmission and distribution systems, it is important to examine each fault in detail. In this work we studied a phase-to-ground fault (on phase 1) of 400 kV overhead transmission line Mintia-Arad. Indactic® 650 fault analyzing system was used to record the history of the fault. Signals (analog and digital) recorded by Indactic® 650 were visualized and analyzed by Focus program. Summary of fault report allowed evaluation of behavior of control and protection equipment and determination of cause and location of the fault.

  9. PIPELINES, TRANSMISSION LINES, AND MISCELLANEOUS TRANSPORTATION FEATURES DIGITAL LINE GRAPHS FOR THE MID-ATLANTIC INTEGRATED ASSESSMENT (MAIA) STUDY AREA

    EPA Science Inventory

    This data set is a geographic information system (GIS) coverage of pipelines, transmission lines, and miscellaneous transportation features for the United States Environmental Protection Agency (USEPA) Mid-Atlantic Integrated Assessment (MAIA) Project region. The coverage was p...

  10. A Novel Transient Fault Current Sensor Based on the PCB Rogowski Coil for Overhead Transmission Lines

    PubMed Central

    Liu, Yadong; Xie, Xiaolei; Hu, Yue; Qian, Yong; Sheng, Gehao; Jiang, Xiuchen

    2016-01-01

    The accurate detection of high-frequency transient fault currents in overhead transmission lines is the basis of malfunction detection and diagnosis. This paper proposes a novel differential winding printed circuit board (PCB) Rogowski coil for the detection of transient fault currents in overhead transmission lines. The interference mechanism of the sensor surrounding the overhead transmission line is analyzed and the guideline for the interference elimination is obtained, and then a differential winding printed circuit board (PCB) Rogowski coil is proposed, where the branch and return line of the PCB coil were designed to be strictly symmetrical by using a joining structure of two semi-rings and collinear twisted pair differential windings in each semi-ring. A serial test is conducted, including the frequency response, linearity, and anti-interference performance as well as a comparison with commercial sensors. Results show that a PCB Rogowski coil has good linearity and resistance to various external magnetic field interferences, thus enabling it to be widely applied in fault-current-collecting devices. PMID:27213402

  11. Number of lightning discharges causing damage to lightning arrester cables for aerial transmission lines in power systems

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

    Nikiforov, E. P.

    2009-07-15

    Damage by lightning discharges to lightning arrester cables for 110-175 kV aerial transmission lines is analyzed using data from power systems on incidents with aerial transmission lines over a ten year operating period (1997-2006). It is found that failures of lightning arrester cables occur when a tensile force acts on a cable heated to the melting point by a lightning current. The lightning currents required to heat a cable to this extent are greater for larger cable cross sections. The probability that a lightning discharge will develop decreases as the amplitude of the lightning current increases, which greatly reduces themore » number of lightning discharges which damage TK-70 cables compared to TK-50 cables. In order to increase the reliability of lightning arrester cables for 110 kV aerial transmission lines, TK-70 cables should be used in place of TK-50 cables. The number of lightning discharges per year which damage lightning arrester cables is lowered when the density of aerial transmission lines is reduced within the territory of electrical power systems. An approximate relationship between these two parameters is obtained.« less

  12. A Method For Modeling Discontinuities In A Microwave Coaxial Transmission Line

    NASA Technical Reports Server (NTRS)

    Otoshi, Tom Y.

    1994-01-01

    A methodology for modeling discountinuities in a coaxial transmission line is presented. The method uses a none-linear least squares fit program to optimize the fit between a theoretical model and experimental data. When the method was applied for modeling discontinuites in a damaged S-band antenna cable, excellent agreement was obtained.

  13. Improving Vacuum Cleaners

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Under a Space Act Agreement between the Kirby company and Lewis Research Center, NASA technology was applied to a commercial vacuum cleaner product line. Kirby engineers were interested in advanced operational concepts, such as particle flow behavior and vibration, critical factors to improve vacuum cleaner performance. An evaluation of the company 1994 home care system, the Kirby G4, led to the refinement of the new G5 and future models. Under the cooperative agreement, Kirby had access to Lewis' holography equipment, which added insight into how long a vacuum cleaner fan would perform, as well as advanced computer software that can simulate the flow of air through fans. The collaboration resulted in several successes including fan blade redesign and continuing dialogue on how to improve air-flow traits in various nozzle designs.

  14. Experimental analysis of a TEM plane transmission line for DNA studies at 900 MHz EM fields

    NASA Astrophysics Data System (ADS)

    Belloni, F.; Doria, D.; Lorusso, A.; Nassisi, V.; Velardi, L.; Alifano, P.; Monaco, C.; Talà, A.; Tredici, M.; Rainò, A.

    2006-07-01

    A suitable plane transmission line was developed and its behaviour analysed at 900 MHz radiofrequency fields to study DNA mutability and the repair of micro-organisms. In this work, utilizing such a device, we investigated the behaviour of DNA mutability and repair of Escherichia coli strains. The transmission line was very simple and versatile in changing its characteristic resistance and field intensity by varying its sizes. In the absence of cell samples inside the transmission line, the relative modulation of the electric and/or magnetic field was ±31% with respect to the mean values, allowing the processing of more samples at different exposure fields in a single run. A slight decrease in spontaneous mutability to rifampicin-resistance of the E. coli JC411 strain was demonstrated in mismatch-repair proficient samples exposed to the radio-frequency fields during their growth on solid medium.

  15. Ultra high vacuum broad band high power microwave window

    DOEpatents

    Nguyen-Tuong, V.; Dylla, H.F. III

    1997-11-04

    An improved high vacuum microwave window has been developed that utilizes high density polyethylene coated on two sides with SiOx, SiNx, or a combination of the two. The resultant low dielectric and low loss tangent window creates a low outgassing, low permeation seal through which broad band, high power microwave energy may be passed. No matching device is necessary and the sealing technique is simple. The features of the window are broad band transmission, ultra-high vacuum compatibility with a simple sealing technique, low voltage standing wave ratio, high power transmission and low cost. 5 figs.

  16. Ultra high vacuum broad band high power microwave window

    DOEpatents

    Nguyen-Tuong, Viet; Dylla, III, Henry Frederick

    1997-01-01

    An improved high vacuum microwave window has been developed that utilizes high density polyethylene coated on two sides with SiOx, SiNx, or a combination of the two. The resultant low dielectric and low loss tangent window creates a low outgassing, low permeation seal through which broad band, high power microwave energy may be passed. No matching device is necessary and the sealing technique is simple. The features of the window are broad band transmission, ultra-high vacuum compatibility with a simple sealing technique, low voltage standing wave ratio, high power transmission and low cost.

  17. Extra-high voltage transmission lines: mechanisms of biological effects on honeybees. Final report

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

    Greenberg, B.; Bindokas, V.

    1985-08-01

    The authors confirmed that bee exposure to E fields, including 100 kV/m, under the dry conditions cause no detectable effect on colony behavior. If, however, exposure occurs when moisture is present, or if bees are on a conductive surface, they become visibly disturbed, mortality is increased, abnormal propolization occurs, and colony development may be impaired. It seems plausible that bees on conductive surfaces within a hive under a 765-kV/m transmission line can perceive shocks from body currents induced by enhanced intra-hive E fields. Hives exposed under a 765-kV/m transmission line to an ambient E field of 7 kV/m have internalmore » step-potential-induced currents and interchamber chort-circuit currents which range from one-half to several microamperes. Total hive currents can exceed 100 ..mu..A. Thus, induced hive currents exceed the empirical sting threshold by up to a factor of 100 and the E-field-induced body current by up to a factor of 1000. The degree of disturbance which could be produced by these intra-hive currents will eclipse that produced by perception of E-field-induced body currents. The authors therefore attribute the disturbance of colonies under a transmission line primarily to electric shock from induced hive currents. 10 refs., 51 figs., 18 tabs. (DT)« less

  18. Underwater spark discharge with long transmission line for cleaning horizontal wells

    NASA Astrophysics Data System (ADS)

    Lee, Kern; Chung, Kyoung-Jae; Hwang, Y. S.; Kim, C. Y.

    2017-06-01

    A transmission line is discussed for application in an underwater spark-discharge technique in the cleaning of a horizontal well by incorporating a power-transmission model into the simulation. The pulsed-spark-discharge technique has been proposed for clogged-well rehabilitation, because it removes incrustations that are attached to well screens by using strong pressure waves that are generated by the rapid expansion of a spark channel. To apply the pulsed-spark-discharge technique to the cleaning of horizontal wells, the coaxial cable between the pulsed power supply and the spark gap as a load needs to be extended to a few hundred meters. Prior to field application, pulsed-spark-discharge experiments were conducted and the role of the transmission line was examined using an improved simulation model. In the model, a non-linear interaction of the spark channel and the capacitor bank is described by the pulse-forming action of the coaxial cable. Based on the accurate physical properties of the water plasma, such as the equation of state and electrical conductivity within the region of interest, the amount of energy contributed to the development of a shock wave was evaluated. The simulation shows that if the initial conditions of the spark channel are the same, no further reduction in strength of the pressure wave occurs, even if the cable length is increased above 50 m. Hence, the degraded peak pressure that was observed in the experiments using the longer cable is attributed to a change in the initial condition of the spark channel. The parametric study suggests that the low initial charging voltage, the high ambient water pressure, and the long cable length yield the low initial spark-channel density, which results in a reduced peak pressure. The simulation of line charging is presented to discuss the principle of disturbing the pre-breakdown process by an extended cable.

  19. Advanced Photon Source accelerator ultrahigh vacuum guide

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

    Liu, C.; Noonan, J.

    1994-03-01

    In this document the authors summarize the following: (1) an overview of basic concepts of ultrahigh vacuum needed for the APS project, (2) a description of vacuum design and calculations for major parts of APS, including linac, linac waveguide, low energy undulator test line, positron accumulator ring (PAR), booster synchrotron ring, storage ring, and insertion devices, and (3) cleaning procedures of ultrahigh vacuum (UHV) components presently used at APS.

  20. 76 FR 21338 - Reopening of Scoping Period for the Northern Pass Transmission Line Project Environmental Impact...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-15

    ... Pass Transmission, LLC, to construct, operate, maintain, and connect a new electric transmission line... Mountain National Forest, and the Army Corps of Engineers, New England District, are cooperating agencies... information on the Army Corps of Engineers' permit [[Page 21339

  1. Sound transmission through double panel constructions lined with elastic porous materials

    NASA Astrophysics Data System (ADS)

    Bolton, J. S.; Green, E. R.

    1986-07-01

    Attention is given to a theory governing one-dimensional wave motion in elastic porous materials which is capable of reproducing experimental transmission measurements for unfaced polyurethane foam layers. Calculations of the transmission loss of fuselage-like foam-lined double panels are presented and it is shown that the foam/panel boundary conditions have a large effect on the panel performance; a hybrid arrangement whereby the foam is bonded directly to one panel and separated from the other by a thin air gap appears to be the most advantageous under practical circumstances. With this configuratiom, the mass-air-mass resonance is minimized and increased low-frequency performance is offered.

  2. Particle trap to sheath contact for a gas-insulated transmission line having a corrugated outer conductor

    DOEpatents

    Fischer, William H.; Cookson, Alan H.; Yoon, Kue H.

    1984-04-10

    A particle trap to outer elongated conductor or sheath contact for gas-insulated transmission lines. The particle trap to outer sheath contact of the invention is applicable to gas-insulated transmission lines having either corrugated or non-corrugated outer sheaths. The contact of the invention includes an electrical contact disposed on a lever arm which in turn is rotatably disposed on the particle trap and biased in a direction to maintain contact between the electrical contact and the outer sheath.

  3. 75 FR 32357 - Gallatin National Forest; Montana; Jack Rabbit to Big Sky Meadow Village 161 kV Transmission Line...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-08

    ... DEPARTMENT OF AGRICULTURE Forest Service Gallatin National Forest; Montana; Jack Rabbit to Big Sky... electric transmission line. The upgraded 161-kV transmission line would connect the existing Jack Rabbit... with eight regional entities to improve the reliability of the bulk power system. The Jack Rabbit to...

  4. Fuzzy-Wavelet Based Double Line Transmission System Protection Scheme in the Presence of SVC

    NASA Astrophysics Data System (ADS)

    Goli, Ravikumar; Shaik, Abdul Gafoor; Tulasi Ram, Sankara S.

    2015-06-01

    Increasing the power transfer capability and efficient utilization of available transmission lines, improving the power system controllability and stability, power oscillation damping and voltage compensation have made strides and created Flexible AC Transmission (FACTS) devices in recent decades. Shunt FACTS devices can have adverse effects on distance protection both in steady state and transient periods. Severe under reaching is the most important problem of relay which is caused by current injection at the point of connection to the system. Current absorption of compensator leads to overreach of relay. This work presents an efficient method based on wavelet transforms, fault detection, classification and location using Fuzzy logic technique which is almost independent of fault impedance, fault distance and fault inception angle. The proposed protection scheme is found to be fast, reliable and accurate for various types of faults on transmission lines with and without Static Var compensator at different locations and with various incidence angles.

  5. Analysis of Safety Protection Measures for Maintenance Work of 500 kV Double-Circuit Transmission Lines on Same Tower

    NASA Astrophysics Data System (ADS)

    Yang, Qi; Zou, Dehua; Zhang, Jianjun; Li, Hui; Chen, Jianping; Li, Jinliang

    2017-05-01

    Four transmission lines on the same tower are widely used because of their obvious economic and social benefits. But it also has high power supply reliability, so the choice of reasonable maintenance mode is particularly important. In this paper, we deducted the maintenance influence of the energized line to non-energized line, calculated and analyzed protection measures of non-energized singular line of 500kV double-circuit transmission line on the same tower with ATP software, and calculated field intensity distribution of typical operating position of the energized double-circuit transmission line with the finite element software. The calculation shows that when using the outage maintenance method, hanging both ground current and personal security line can reduce the current flowing through the operator’s body effectively. When using the live maintenance method, the field intensity of operator body strengths up to 383.69kV/m, The operator needs to wear shielding cloth with at least 43.08 dB shielding efficiency, in order to meet the security requirements.

  6. A novel structure of transmission line pulse transformer with mutually coupled windings.

    PubMed

    Yu, Binxiong; Su, Jiancang; Li, Rui; Zhao, Liang; Zhang, Xibo; Wang, Junjie

    2014-03-01

    A novel structure of transmission line transformer (TLT) with mutually coupled windings is described in this paper. All transmission lines except the first stage of the transformer are wound on a common ferrite core for the TLT with this structure. A referral method was introduced to analyze the TLT with this structure, and an analytic expression of the step response was derived. It is shown that a TLT with this structure has a significantly slower droop rate than a TLT with other winding structures and the number of ferrite cores needed is largely reduced. A four-stage TLT with this structure was developed, whose input and output impedance were 4.2 Ω and 67.7 Ω, respectively. A frequency response test of the TLT was carried out. The test results showed that pulse response time of the TLT is several nanoseconds. The TLT described in this paper has the potential to be used as a rectangle pulse transformer with very fast response time.

  7. New circuit theory of multiconductor transmission lines resulting from a new practice of noise reduction.

    PubMed

    Toki, Hiroshi; Sato, Kenji

    2014-01-01

    In modern life, we are surrounded by and filled with electromagnetic noise caused by the dominant use of energy in the form of electricity. This situation is brought about by the fact that the noise is not understood theoretically. A new practice of noise reduction was introduced for the construction of Heavy Ion Medical Accelerator in Chiba (HIMAC). The key concept is a symmetric three-line circuit that arranges power supplies, noise filters and magnets around a third central ground line. A continuous theoretical effort forced us to find a new circuit theory involving a multiconductor transmission-line system starting from Maxwell's equations without any approximation. We discuss the essence of all of these experimental and theoretical developments with the hope to remove unnecessary electromagnetic noise not only from power supplies, but also from all electric devices. The newly derived circuit theory of multiconductor transmission lines is universal, and establishes the validity of the practice of noise reduction.

  8. New circuit theory of multiconductor transmission lines resulting from a new practice of noise reduction

    PubMed Central

    TOKI, Hiroshi; SATO, Kenji

    2014-01-01

    In modern life, we are surrounded by and filled with electromagnetic noise caused by the dominant use of energy in the form of electricity. This situation is brought about by the fact that the noise is not understood theoretically. A new practice of noise reduction was introduced for the construction of Heavy Ion Medical Accelerator in Chiba (HIMAC). The key concept is a symmetric three-line circuit that arranges power supplies, noise filters and magnets around a third central ground line. A continuous theoretical effort forced us to find a new circuit theory involving a multiconductor transmission-line system starting from Maxwell’s equations without any approximation. We discuss the essence of all of these experimental and theoretical developments with the hope to remove unnecessary electromagnetic noise not only from power supplies, but also from all electric devices. The newly derived circuit theory of multiconductor transmission lines is universal, and establishes the validity of the practice of noise reduction. PMID:24522153

  9. Supplement Analysis for the Transmission System Vegetation Management Program FEIS (DOE/EIS-0285/SA-221) Project #: V-O-04/10 - Paul-Allston No 1 and 2 - 500 kV Transmission Line Corridor

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

    Stratton, Elaine S.

    2004-07-26

    The project activities will be conducted along the Right-of-Way (ROW) of the Paul-Allston No 1 and 2 - 500 kV transmission line corridor between towers 45/4 and the Allston substation. This corridor includes portions of the Longview-Allston No 1 and 2 and the Longview-Allston No 3 and 4 - 230 kV transmission lines. The corridor along this section of the proposed project varies between 125 and 150 feet in width and crosses approximately 4 miles of terrain from Longview, Washington crossing the Columbia River and passing through rural forestland and pasture lands to the Allston Substation in Oregon. BPA proposesmore » to remove unwanted vegetation along the right-of-way, along access roads and around tower structures along the subject transmission line corridor that may impede the operation and maintenance of the identified transmission lines. BPA plans to conduct vegetation control with the goal of removing tall growing vegetation that is currently or will soon be a hazard to the transmission line. BPA’s overall goal is to have low-growing plant communities along the rights-of-way to control the development of potentially threatening vegetation.« less

  10. Supplement Analysis for the Transmission System Vegetation Management Program FEIS (DOE/EIS-0285-SA-32) - Re-Vegetation Plot Study Along the Lower Monumental-McNary Transmission Line ROW

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

    Hutchinson, Ken

    2001-11-15

    Re-vegetation Plot Study along the Lower Monumental-McNary Transmission Line ROW. The study area sections are located near structures 38/4 and 39/3. The line is a 500kV Single Circuit Transmission Line having an easement width of 165 feet. The proposed work will be accomplished in the indicated sections of the transmission line corridor as indicated on the attached checklist. A summer of 2001 fire burned the subject area leaving the ROW in a bare ground situation. Before, the fire the site was dominated by annual vegetation (cheatgrass) and noxious weeds (yellowstar thistle). As a study of plant succession after the firemore » for a local Boy Scout group, two 100 X 100 foot areas will be identified for study over the next 2-3 years. The two test plots will be identified and permanently marked. One will receive treatment while the other will not be treated and used as a control plot.« less

  11. Monitoring of Overhead Transmission Lines: A Review from the Perspective of Contactless Technologies

    NASA Astrophysics Data System (ADS)

    Khawaja, Arsalan Habib; Huang, Qi; Khan, Zeashan Hameed

    2017-12-01

    This paper describes a comprehensive review of non-contact technologies for overhead power transmission lines. Due to ever increasing emphasis on reducing accidents and speeding up diagnosis for automatically controlled grids, real time remote sensing and actuation is the new horizon for smart grid implementation. The technology overview with emphasis on the practical implementation of advanced non-contact technologies is discussed in this paper while considering optimization of the high voltage transmission lines parameters. In case of fault, the voltage and the current exceed limits of operation and hence real time reporting for control and diagnosis is a critical requirement. This paper aims to form a strong foundation for control and diagnosis of future power distribution systems so that a practitioner or researcher can make choices for a workable solution in smart grid implementation based on non-contact sensing.

  12. An experimental test of the 'transmission-line model' of electromagnetic radiation from triggered lightning return strokes

    NASA Technical Reports Server (NTRS)

    Willett, J. C.; Idone, V. P.; Orville, R. E.; Leteinturier, C.; Eybert-Berard, A.

    1988-01-01

    Peak currents, two-dimensional average propagation speeds, and electric field waveforms for a number of subsequent return strikes in rocket-triggered lightning flashes were measured in order to test the 'transmission-line model' of return-stroke radiation of Uman and McLain (1970). Reasonable agreement is found between the propagation speeds measured with the streak camera and those deduced from the transmission-line model. A modification of the model is proposed in which two wave fronts travel upward and downward away from a junction point a short distance above the ground.

  13. An experimental test of the 'transmission-line model' of electromagnetic radiation from triggered lightning return strokes

    NASA Astrophysics Data System (ADS)

    Willett, J. C.; Idone, V. P.; Orville, R. E.; Leteinturier, C.; Eybert-Berard, A.

    1988-04-01

    Peak currents, two-dimensional average propagation speeds, and electric field waveforms for a number of subsequent return strikes in rocket-triggered lightning flashes were measured in order to test the 'transmission-line model' of return-stroke radiation of Uman and McLain (1970). Reasonable agreement is found between the propagation speeds measured with the streak camera and those deduced from the transmission-line model. A modification of the model is proposed in which two wave fronts travel upward and downward away from a junction point a short distance above the ground.

  14. An ultrahigh vacuum multipurpose specimen chamber with sample introduction system for in situ transmission electron microscopy investigations

    NASA Technical Reports Server (NTRS)

    Heinemann, K.; Poppa, H.

    1986-01-01

    A commercial transmission electron microscope (TEM), with flat-plate upper pole piece configuration of the objective lens, and top-entry specimen introduction was modified by introducing an ultrahigh vacuum (UHV) specimen chamber for in situ TEM experimentation. The pumping and design principles and special features of this UHV chamber, which makes it possible to obtain 5 x 10 to the -10th mbar pressure at the site of the specimen, while maintaining the airlock system that allows operation in the 10 to the -10th mbar range within 15 min after specimen change, are described. Design operating pressures and image quality (resolution of metal particles smaller than 1 nm in size) were achieved. Schematic drawings and design dimensions are included.

  15. [Study on effects of bioelectric parameters of rats in electromagnetic radiation of HV transmission line].

    PubMed

    Zhang, Anying; Pang, Xiaofeng; Yuan, Ping

    2007-02-01

    With the development of economy and coming of information era, the chance of exposure to electromagnetic fields with various frequencies has been increased for every human. The effects of electromagnetic radiattion on human being's health are versatile. To study the effects of bioelctronic parameters of rats in the electromagnetic radiations of HV transmission line, EEG, ECG and CMAP were measured in rats exposed to simulating high-voltage transmission line electromagnetic radiation for over one year. Brain tissues were studied by Fourier transform infrared spectroscopy. The results showed that no significant difference between exposed group and control group in EEG; however the FT-infrared spectra of brain tissues were different; the ECG of the exposed animals was considerably altered. Significant slowing of heart rate was observed in those rates exposed to EMFs; the latent period of CMAP in exposed group were not different compared with those of control group however there was a significant difference in wave amplitude of CMAP between the exposed group and control group. All results indicated that there must be some effects on bioelectric parameters of rats exposed to electromagnetic radiation of high-voltage transmission line for a long time.

  16. Semi-flexible gas-insulated transmission line using protection tube in conductor plug-in joint

    DOEpatents

    Kommineni, P.R.

    1983-01-25

    A gas-insulated transmission line includes an outer sheath, an inner conductor, an insulating gas electrically insulating the inner conductor from the outer sheath, and insulating supports insulatably supporting the inner conductor within the outer sheath. The inner conductor is provided with flexibility by main conductor sections which are joined together through a conductor hub section and flexible flexing elements. Stress shields are provided to control the electric field at the locations of the conductor hub sections where the insulating supports are contacting the inner conductor. A plug and socket arrangement is utilized for joining adjacent sections of the inner conductor, and a protection tube is utilized inside the hollow plug to maintain proper alignment of the joint when the transmission line is bent. 3 figs.

  17. Semi-flexible gas-insulated transmission line using protection tube in conductor plug-in joint

    DOEpatents

    Kommineni, Prasad R.

    1983-01-25

    A gas-insulated transmission line includes an outer sheath, an inner conductor, an insulating gas electrically insulating the inner conductor from the outer sheath, and insulating supports insulatably supporting the inner conductor within the outer sheath. The inner conductor is provided with flexibility by main conductor sections which are joined together through a conductor hub section and flexible flexing elements. Stress shields are provided to control the electric field at the locations of the conductor hub sections where the insulating supports are contacting the inner conductor. A plug and socket arrangement is utilized for joining adjacent sections of the inner conductor, and a protection tube is utilized inside the hollow plug to maintain proper alignment of the joint when the transmission line is bent.

  18. Stress Analysis of Boom of Special Mobile Crane for Plain Region in Transmission Line

    NASA Astrophysics Data System (ADS)

    Qin, Jian; Shao, Tao; Chen, Jun; Wan, Jiancheng; Li, Zhonghuan; Jiang, Ming

    2017-10-01

    Basis of the boom force analysis of special mobile crane for plain region in transmission line, the load type of boom design is confirmed. According to the different combinations of boom sections, the composite pattern of the different boom length is obtained to suit the actual conditions of boom overlapping. The large deformation model is employed with FEM to simulate the stress distribution of boom, and the calculation results are checked. The performance curves of rated load with different arm length and different working range are obtained, which ensures the lifting capacity of special mobile crane meeting the requirement of tower erection of transmission line. The proposed FEM of boom of mobile crane would provide certain guiding and reference to the boom design.

  19. A vacuum sealed high emission current and transmission efficiency carbon nanotube triode

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

    Di, Yunsong; Jiangsu Key Laboratory of Optoelectronic Technology, Nanjing Normal University, Nanjing 210023; Wang, Qilong

    A vacuum sealed carbon nanotubes (CNTs) triode with a concave and spoke-shaped Mo grid is presented. Due to the high aperture ratio of the grid, the emission current could be modulated at a relatively high electric field. Totally 75 mA emission current has been obtained from the CNTs cathode with the average applied field by the grid shifting from 8 to 13 V/μm. Whilst with the electron transmission efficiency of the grid over 56%, a remarkable high modulated current electron beam over 42 mA has been collected by the anode. Also contributed by the high aperture ration of the grid,more » desorbed gas molecules could flow away from the emission area rapidly when the triode has been operated at a relative high emission current, and finally collected by a vacion pump. The working pressure has been maintained at ∼1 × 10{sup −7} Torr, seldom spark phenomena occurred. Nearly perfect I-V curve and corresponding Fowler-Nordheim (FN) plot confirmed the accuracy of the measured data, and the emission current was long term stable and reproducible. Thusly, this kind of triode would be used as a high-power electron source.« less

  20. Reduction of radiation loss at small-radius bend using spoof surface plasmon polariton transmission line

    NASA Astrophysics Data System (ADS)

    Tang, Wen Xuan; Zhang, Hao Chi; Liu, Jun Feng; Xu, Jie; Cui, Tie Jun

    2017-01-01

    Spoof surface plasmon polariton (SPP) has been realized at low frequencies through corrugated metallic structures. As two-dimensional application, the ultrathin SPP transmission lines (TLs) have been proposed with great potentials for microwave compact circuits due to the strong field confinement and enhancement, as well as controllable dispersive properties. In this paper, we examine the radiation loss at small-radius bend, which may cause severe crosstalk in highly-integrated circuits or systems, for the SPP TLs. We theoretically analyze that the SPP TL has essential merit of low radiation loss, and show better performance of SPP TL than the conventional microstrip line through numerical simulations and experiments. Both simulated and measured results demonstrate that the new type of transmission line can efficiently suppress the radiation loss at small-radius bend, and hence reduce the crosstalk in circuits and systems.

  1. Wild Horse 69-kV transmission line environmental assessment

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

    NONE

    1996-12-01

    Hill County Electric Cooperative Inc. (Hill County) proposes to construct and operate a 69-kV transmission line from its North Gildford Substation in Montana north to the Canadian border. A vicinity project area map is enclosed as a figure. TransCanada Power Corporation (TCP), a Canadian power-marketing company, will own and construct the connecting 69-kV line from the international border to Express Pipeline`s pump station at Wild Horse, Alberta. This Environmental Assessment is prepared for the Department of Energy (DOE) as lead federal agency to comply with the requirements of the National Environmental Policy Act (NEPA), as part of DOE`s review andmore » approval process of the applications filed by Hill County for a DOE Presidential Permit and License to Export Electricity to a foreign country. The purpose of the proposed line is to supply electric energy to a crude oil pump station in Canada, owned by Express Pipeline Ltd. (Express). The pipeline would transport Canadian-produced oil from Hardisty, Alberta, Canada, to Caster, Wyoming. The Express Pipeline is scheduled to be constructed in 1996--97 and will supply crude oil to refineries in Wyoming and the midwest.« less

  2. Compact Feed Circuit with Quarter Wavelength Transmission Line Matrix Controlling Beams in Three Directions Including Boresight

    NASA Astrophysics Data System (ADS)

    Tsuji, Masatoshi

    A compact feed circuit with a λ/4 transmission line matrix circuit for use in array antennas to control beams in three directions, including boresight, is presented. The feed circuit antenna is composed of five switches and λ/4 transmission lines, and the feeding matrix circuit yields phase differences of ±90° and 0°. The feed circuit can obtain a reliable output signal, as there is only a small degree of deviation of output signal with variations in the line width. The feed circuit is simulated, fabricated, and evaluated for ISM band, and the measured characteristics agree well with the results of the simulation. The size of feed circuit is 45 (H) × 48 (W) × 3 (T) mm.

  3. Performance Analysis of the ITER Plasma Position Reflectometry (PPR) Ex-vessel Transmission Lines

    NASA Astrophysics Data System (ADS)

    Martínez-Fernández, J.; Simonetto, A.; Cappa, Á.; Rincón, M. E.; Cabrera, S.; Ramos, F. J.

    2018-03-01

    As the design of the ITER Plasma Position Reflectometry (PPR) diagnostic progresses, some segments of the transmission line have become fully specified and estimations of their performance can already be obtained. This work presents the calculations carried out for the longest section of the PPR, which is in final state of design and will be the main contributor to the total system performance. Considering the 88.9 mm circular corrugated waveguide (CCWG) that was previously chosen, signal degradation calculations have been performed. Different degradation sources have been studied: ohmic attenuation losses for CCWG; mode conversion losses for gaps, mitre bends, waveguide sag and different types of misalignments; reflection and absorption losses due to microwave windows and coupling losses to free space Gaussian beam. Contributions from all these sources have been integrated to give a global estimation of performance in the transmission lines segments under study.

  4. 49 CFR 192.476 - Internal corrosion control: Design and construction of transmission line.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Internal corrosion control: Design and... STANDARDS Requirements for Corrosion Control § 192.476 Internal corrosion control: Design and construction of transmission line. (a) Design and construction. Except as provided in paragraph (b) of this...

  5. 49 CFR 192.476 - Internal corrosion control: Design and construction of transmission line.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Internal corrosion control: Design and... STANDARDS Requirements for Corrosion Control § 192.476 Internal corrosion control: Design and construction of transmission line. (a) Design and construction. Except as provided in paragraph (b) of this...

  6. 49 CFR 192.476 - Internal corrosion control: Design and construction of transmission line.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Internal corrosion control: Design and... STANDARDS Requirements for Corrosion Control § 192.476 Internal corrosion control: Design and construction of transmission line. (a) Design and construction. Except as provided in paragraph (b) of this...

  7. 49 CFR 192.476 - Internal corrosion control: Design and construction of transmission line.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Internal corrosion control: Design and... STANDARDS Requirements for Corrosion Control § 192.476 Internal corrosion control: Design and construction of transmission line. (a) Design and construction. Except as provided in paragraph (b) of this...

  8. 49 CFR 192.476 - Internal corrosion control: Design and construction of transmission line.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Internal corrosion control: Design and... STANDARDS Requirements for Corrosion Control § 192.476 Internal corrosion control: Design and construction of transmission line. (a) Design and construction. Except as provided in paragraph (b) of this...

  9. Fractional analysis for nonlinear electrical transmission line and nonlinear Schroedinger equations with incomplete sub-equation

    NASA Astrophysics Data System (ADS)

    Fendzi-Donfack, Emmanuel; Nguenang, Jean Pierre; Nana, Laurent

    2018-02-01

    We use the fractional complex transform with the modified Riemann-Liouville derivative operator to establish the exact and generalized solutions of two fractional partial differential equations. We determine the solutions of fractional nonlinear electrical transmission lines (NETL) and the perturbed nonlinear Schroedinger (NLS) equation with the Kerr law nonlinearity term. The solutions are obtained for the parameters in the range (0<α≤1) of the derivative operator and we found the traditional solutions for the limiting case of α =1. We show that according to the modified Riemann-Liouville derivative, the solutions found can describe physical systems with memory effect, transient effects in electrical systems and nonlinear transmission lines, and other systems such as optical fiber.

  10. Planning Electric Transmission Lines: A Review of Recent Regional Transmission Plans

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

    Eto, Joseph H.

    The first Quadrennial Energy Review (QER) recommends that the U.S. Department of Energy (DOE) conduct a national review of transmission plans and assess the barriers and incentives to their implementation. DOE tasked Lawrence Berkeley National Laboratory (LBNL) to prepare two reports to support the agency’s response to this recommendation. This report reviews regional transmission plans and regional transmission planning processes that have been directed by Federal Energy Regulatory Commission (FERC) Order Nos. 890 and 1000. We focus on the most recent regional transmission plans (those issued in 2015 and through approximately mid-year 2016) and current regional transmission planning processes. Amore » companion report focuses on non-plan-related factors that affect transmission projects.« less

  11. A Fault Location Algorithm for Two-End Series-Compensated Double-Circuit Transmission Lines Using the Distributed Parameter Line Model

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

    Kang, Ning; Gombos, Gergely; Mousavi, Mirrasoul J.

    A new fault location algorithm for two-end series-compensated double-circuit transmission lines utilizing unsynchronized two-terminal current phasors and local voltage phasors is presented in this paper. The distributed parameter line model is adopted to take into account the shunt capacitance of the lines. The mutual coupling between the parallel lines in the zero-sequence network is also considered. The boundary conditions under different fault types are used to derive the fault location formulation. The developed algorithm directly uses the local voltage phasors on the line side of series compensation (SC) and metal oxide varistor (MOV). However, when potential transformers are not installedmore » on the line side of SC and MOVs for the local terminal, these measurements can be calculated from the local terminal bus voltage and currents by estimating the voltages across the SC and MOVs. MATLAB SimPowerSystems is used to generate cases under diverse fault conditions to evaluating accuracy. The simulation results show that the proposed algorithm is qualified for practical implementation.« less

  12. A Line Impedance Conditioner for Saturation Mitigation of Zigzag Transformer in Hybrid AC/DC Transmission System Considering Line Unbalances

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

    Liu, Bo; Shi, Xiaojie M.; Li, Yalong

    Hybrid ac/dc transmission extends the power transfer capacity of existing long ac lines closer to their thermal limit, by superposing the dc current onto three-phase ac lines through a zigzag transformer. However, this transformer could suffer saturation under unbalanced line impedance conditions. This paper introduces the concept of hybrid line impedance conditioner (HLIC) as a cost-effective approach to compensate for the line unbalance and therefore avoid saturation. The topology and operation principle are presented. The two-level control strategy is described, which enables autonomous adaptive regulation without the need of system-level control. Design and implementation are also analyzed, including dc-link capacitancemore » as one of the key line conditioner components, HLIC installation, and protection under fault conditions. The cost study on this HLIC-based hybrid system is also performed to reveal the benefits of the solution. In conclusion, simulation results and experimental results based on a down-scaled prototype are provided to verify the feasibility of the proposed approach.« less

  13. A Line Impedance Conditioner for Saturation Mitigation of Zigzag Transformer in Hybrid AC/DC Transmission System Considering Line Unbalances

    DOE PAGES

    Liu, Bo; Shi, Xiaojie M.; Li, Yalong; ...

    2016-09-13

    Hybrid ac/dc transmission extends the power transfer capacity of existing long ac lines closer to their thermal limit, by superposing the dc current onto three-phase ac lines through a zigzag transformer. However, this transformer could suffer saturation under unbalanced line impedance conditions. This paper introduces the concept of hybrid line impedance conditioner (HLIC) as a cost-effective approach to compensate for the line unbalance and therefore avoid saturation. The topology and operation principle are presented. The two-level control strategy is described, which enables autonomous adaptive regulation without the need of system-level control. Design and implementation are also analyzed, including dc-link capacitancemore » as one of the key line conditioner components, HLIC installation, and protection under fault conditions. The cost study on this HLIC-based hybrid system is also performed to reveal the benefits of the solution. In conclusion, simulation results and experimental results based on a down-scaled prototype are provided to verify the feasibility of the proposed approach.« less

  14. Design of a broadband band-pass filter with notch-band using new models of coupled transmission lines.

    PubMed

    Daryasafar, Navid; Baghbani, Somaye; Moghaddasi, Mohammad Naser; Sadeghzade, Ramezanali

    2014-01-01

    We intend to design a broadband band-pass filter with notch-band, which uses coupled transmission lines in the structure, using new models of coupled transmission lines. In order to realize and present the new model, first, previous models will be simulated in the ADS program. Then, according to the change of their equations and consequently change of basic parameters of these models, optimization and dependency among these parameters and also their frequency response are attended and results of these changes in order to design a new filter are converged.

  15. Research on influence of different cover to the characteristic of FBG reflectance spectrum in vacuum thermal environment

    NASA Astrophysics Data System (ADS)

    Pei, Yifei; Zhang, Jingchuan; Zhang, Luosha; Liu, Yang; Zhang, Lina; Chen, Shiyu

    2018-01-01

    To satisfy the application of fiber grating sensor technology in high vacuum thermal environment, two different kinds of sleeve compactly single model fiber covered by acrylate and polyimide are researched. Influence of the cover to the characteristic of FBG reflectance spectrum in high vacuum thermal environment is analyzed and verified. First, transmission characteristic of single model fiber in high vacuum thermal environment is analyzed by solve the equation of heat conduction. Then, experimental program of influence on FBG reflection spectrum characteristics is designed and a hardware-in-the-loop detection platform is set up. Finally, the influence of temperature and vacuum on the reflection peak power of FBG in different coating single-mode transmission fiber under high vacuum thermal environment is studied and verified. Experimental results indicate that: when vacuum varied from normal pressure to 10-4Pa level and then return to normal pressure, temperature of two different coating single-mode transmission fiber dropped to -196 ° from room temperature and then returned to room temperature, after 224 hours, the peak power of the FBG reflectance spectrum did not change. It provided the theoretical and experimental basis for the application of optical fiber sensing technology in high vacuum (pressure about 10-4Pa level) and thermal environment (-196 ° 25 ° temperature cycle) .

  16. Homogenate-assisted Vacuum-powered Bubble Extraction of Moso Bamboo Flavonoids for On-line Scavenging Free Radical Capacity Analysis.

    PubMed

    Sun, Yinnan; Yang, Kui; Cao, Qin; Sun, Jinde; Xia, Yu; Wang, Yinhang; Li, Wei; Ma, Chunhui; Liu, Shouxin

    2017-07-11

    A homogenate-assisted vacuum-powered bubble extraction (HVBE) method using ethanol was applied for extraction of flavonoids from Phyllostachys pubescens (P. pubescens) leaves. The mechanisms of homogenate-assisted extraction and vacuum-powered bubble generation were discussed in detail. Furthermore, a method for the rapid determination of flavonoids by HPLC was established. HVBE followed by HPLC was successfully applied for the extraction and quantification of four flavonoids in P. pubescens , including orientin, isoorientin, vitexin, and isovitexin. This method provides a fast and effective means for the preparation and determination of plant active components. Moreover, the on-line antioxidant capacity, including scavenging positive ion and negative ion free radical capacity of different fractions from the bamboo flavonoid extract was evaluated. Results showed that the scavenging DPPH ˙ free radical capacity of vitexin and isovitexin was larger than that of isoorientin and orientin. On the contrary, the scavenging ABTS⁺ ˙ free radical capacity of isoorientin and orientin was larger than that of vitexin and isovitexin.

  17. High sensitive FBG load cell for icing of overhead transmission lines

    NASA Astrophysics Data System (ADS)

    Mao, Naiqiang; Ma, Guoming; Li, Chengrong; Li, Yabo; Shi, Cheng; Du, Yue

    2017-04-01

    Heavy ice coating of overhead transmission lines created the serious threat on the safe operation of power grid. The measurement of conductor icing had been an effective and reliable methods to prevent potential risks, such as conductor breakage, insulator flashover and tower collapse. Because of the advantages of immunity to electromagnetic interference and no demand for power supply in site, the optical load cell has been widely applied in monitoring the ice coating of overhead transmission lines. In this paper, we have adopted the shearing structure with additional grooves as elastic element of load cell to detect the eccentric load. Then, two welding package fiber Bragg gratings (FBGs) were mounted onto the grooves of elastic element with a direction deviation of 90° to eliminate temperature effects on strain measurement without extra FBG. After that, to avoid the occurrence of load cell breakage in heavy load measurement, the protection part has been proposed and added to the elastic element. The results of tension experiments indicate that the resolution of the load cell is 7.78 N in the conventional measuring range (0-10 kN). And in addition, the load cell proposed in this paper also has a good performance in actual experiment in which the load and temperature change simultaneously.

  18. Full circuit calculation for electromagnetic pulse transmission in a high current facility

    NASA Astrophysics Data System (ADS)

    Zou, Wenkang; Guo, Fan; Chen, Lin; Song, Shengyi; Wang, Meng; Xie, Weiping; Deng, Jianjun

    2014-11-01

    We describe herein for the first time a full circuit model for electromagnetic pulse transmission in the Primary Test Stand (PTS)—the first TW class pulsed power driver in China. The PTS is designed to generate 8-10 MA current into a z -pinch load in nearly 90 ns rise time for inertial confinement fusion and other high energy density physics research. The PTS facility has four conical magnetic insulation transmission lines, in which electron current loss exists during the establishment of magnetic insulation. At the same time, equivalent resistance of switches and equivalent inductance of pinch changes with time. However, none of these models are included in a commercially developed circuit code so far. Therefore, in order to characterize the electromagnetic transmission process in the PTS, a full circuit model, in which switch resistance, magnetic insulation transmission line current loss and a time-dependent load can be taken into account, was developed. Circuit topology and an equivalent circuit model of the facility were introduced. Pulse transmission calculation of shot 0057 was demonstrated with the corresponding code FAST (full-circuit analysis and simulation tool) by setting controllable parameters the same as in the experiment. Preliminary full circuit simulation results for electromagnetic pulse transmission to the load are presented. Although divergences exist between calculated and experimentally obtained waveforms before the vacuum section, consistency with load current is satisfactory, especially at the rising edge.

  19. Magnetic Insulation in Coaxial Transmission Lines with an External Magnetic Field

    DTIC Science & Technology

    1980-03-13

    A. Mostrom, Michael E. Jones, and Lester E. Thode SUBMITTED TO: Physical Review Letters March 13, 1980 SöKOK_Kä^MJ!L;; ÄgEie?©d tea gas &c...Number Assigned by Contract Monitor: SLL 81- 262 Comments on Document: Archive, RRI, DEW . From Physical Review Letters Descriptors, Keywords: Magnetic...Source of Document: DEW MAGNETIC INSULATION IN COAXIAL TRANSMISSION LINES WITH AN EXTERNAL MAGNETIC FIELD Michael A. Mostrom, Michael E. Jones, and

  20. Evaluation of Fibre Lifetime in Optical Ground Wire Transmission Lines

    NASA Astrophysics Data System (ADS)

    Grunvalds, R.; Ciekurs, A.; Porins, J.; Supe, A.

    2017-06-01

    In the research, measurements of polarisation mode dispersion of two OPGWs (optical ground wire transmission lines), in total four fibres, have been carried out, and the expected lifetime of the infrastructure has been assessed on the basis of these measurements. The cables under consideration were installed in 1995 and 2011, respectively. Measurements have shown that polarisation mode dispersion values for cable installed in 1995 are four times higher than that for cable installed in 2011, which could mainly be explained by technological differences in fibre production and lower fibre polarisation mode dispersion requirements in 1995 due to lack of high-speed (over 10 Gbit/s) optical transmission systems. The calculation methodology of non-refusal work and refusal probabilities, using the measured polarisation mode dispersion parameters, is proposed in the paper. Based on reliability calculations, the expected lifetime is then predicted, showing that all measured fibres most likely will be operational within minimum theoretical service life of 25 years accepted by the industry.

  1. Optical modeling of fiber organic photovoltaic structures using a transmission line method.

    PubMed

    Moshonas, N; Stathopoulos, N A; O'Connor, B T; Bedeloglu, A Celik; Savaidis, S P; Vasiliadis, S

    2017-12-01

    An optical model has been developed and evaluated for the calculation of the external quantum efficiency of cylindrical fiber photovoltaic structures. The model is based on the transmission line theory and has been applied on single and bulk heterojunction fiber-photovoltaic cells. Using this model, optimum design characteristics have been proposed for both configurations, and comparison with experimental results has been assessed.

  2. Environmental Assessment and Finding of No Significant Impact: Western's Hoover Dam Bypass Project Phase II (Double-Circuiting a Portion of the Hoover-Mead No.5 and No.7 230-kV Transmission Lines with the Henderson-Mead No.1 230-kV Transmission Line, Clark County, Nevada)

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

    N /A

    2003-10-27

    The U.S. Highway 93 (U.S. 93) Hoover Dam Bypass Project calls for the U.S. Department of Energy (DOE) Western Area Power Administration (Western) to remove its Arizona and Nevada (A&N) Switchyard. As a result of this action, Western must reconfigure its existing electrical transmission system in the Hoover Dam area. Western proposes to double-circuit a portion of the Hoover-Mead No.5 and No.7 230-kV Transmission Lines with the Henderson-Mead No.1 Transmission Line (see Figure 1-1). Double-circuiting is the placement of two separate electrical circuits, typically in the form of three separate conductors or bundles of conductors, on the same set ofmore » transmission line structures. The old Henderson-Hoover 230-kV Transmission Line would become the new Henderson-Mead No.1 and would extend approximately eight miles to connect with the Mead Substation. Western owns, operates, and maintains the Hoover-Mead No.5 and No.7, and Henderson-Hoover electrical power transmission lines. Additionally, approximately 0.25 miles of new right-of-way (ROW) would be needed for the Henderson-Mead No.1 when it transfers from double-circuiting with the Hoover-Mead No.7 to the Hoover-Mead No.5 at the Boulder City Tap. The proposed project would also involve a new transmission line ROW and structures where the Henderson-Mead No.1 will split from the Hoover-Mead No.5 and enter the northeast corner of the Mead Substation. Lastly, Western has proposed adding fiber optic overhead ground wire from the Hoover Power Plant to the Mead Substation on to the Henderson-Mead No.1, Hoover-Mead No.5 and No.7 Transmission Lines. The proposed project includes replacing existing transmission line tower structures, installing new structures, and adding new electrical conductors and fiber optic cables. As a consequence of these activities, ground disturbance may result from grading areas for structure placement, constructing new roads, improving existing roads for vehicle and equipment access, and from

  3. On-chip sub-terahertz surface plasmon polariton transmission lines with mode converter in CMOS

    PubMed Central

    Liang, Yuan; Yu, Hao; Wen, Jincai; Apriyana, Anak Agung Alit; Li, Nan; Luo, Yu; Sun, Lingling

    2016-01-01

    An on-chip low-loss and high conversion efficiency plasmonic waveguide converter is demonstrated at sub-THz in CMOS. By introducing a subwavelength periodic corrugated structure onto the transmission line (T-line) implemented by a top-layer metal, surface plasmon polaritons (SPP) are established to propagate signals with strongly localized surface-wave. To match both impedance and momentum of other on-chip components with TEM-wave propagation, a mode converter structure featured by a smooth bridge between the Ground coplanar waveguide (GCPW) with 50 Ω impedance and SPP T-line is proposed. To further reduce area, the converter is ultimately simplified to a gradual increment of groove with smooth gradient. The proposed SPP T-lines with the converter is designed and fabricated in the standard 65 nm CMOS process. Both near-field simulation and measurement results show excellent conversion efficiency from quasi-TEM to SPP modes in a broadband frequency range. The converter achieves wideband impedance matching (<−9 dB) with excellent transmission efficiency (averagely −1.9 dB) from 110 GHz–325 GHz. The demonstrated compact and wideband SPP T-lines with mode converter have shown great potentials to replace existing waveguides as future on-chip THz interconnects. To the best of the author’s knowledge, this is the first time to demonstrate the (sub)-THz surface mode conversion on-chip in CMOS technology. PMID:27444782

  4. Overview spectra and axial distribution of spectral line intensities in a high-current vacuum arc with CuCr electrodes

    NASA Astrophysics Data System (ADS)

    Lisnyak, M.; Pipa, A. V.; Gorchakov, S.; Iseni, S.; Franke, St.; Khapour, A.; Methling, R.; Weltmann, K.-D.

    2015-09-01

    Spectroscopic investigations of free-burning vacuum arcs in diffuse mode with CuCr electrodes are presented. The experimental conditions of the investigated arc correspond to the typical system for vacuum circuit breakers. Spectra of six species Cu I, Cu II, Cu III, Cr I, Cr II, and Cr III have been analyzed in the wavelength range 350-810 nm. The axial intensity distributions were found to be strongly dependent on the ionization stage of radiating species. Emission distributions of Cr II and Cu II can be distinguished as well as the distributions of Cr III and Cu III. Information on the axial distribution was used to identify the spectra and for identification of overlapping spectral lines. The overview spectra and some spectral windows recorded with high resolution are presented. Analysis of axial distributions of emitted light, which originates from different ionization states, is presented and discussed.

  5. Monolithic high voltage nonlinear transmission line fabrication process

    DOEpatents

    Cooper, Gregory A.

    1994-01-01

    A process for fabricating sequential inductors and varactor diodes of a monolithic, high voltage, nonlinear, transmission line in GaAs is disclosed. An epitaxially grown laminate is produced by applying a low doped active n-type GaAs layer to an n-plus type GaAs substrate. A heavily doped p-type GaAs layer is applied to the active n-type layer and a heavily doped n-type GaAs layer is applied to the p-type layer. Ohmic contacts are applied to the heavily doped n-type layer where diodes are desired. Multiple layers are then either etched away or Oxygen ion implanted to isolate individual varactor diodes. An insulator is applied between the diodes and a conductive/inductive layer is thereafter applied on top of the insulator layer to complete the process.

  6. Transmission-line model to design matching stage for light coupling into two-dimensional photonic crystals.

    PubMed

    Miri, Mehdi; Khavasi, Amin; Mehrany, Khashayar; Rashidian, Bizhan

    2010-01-15

    The transmission-line analogy of the planar electromagnetic reflection problem is exploited to obtain a transmission-line model that can be used to design effective, robust, and wideband interference-based matching stages. The proposed model based on a new definition for a scalar impedance is obtained by using the reflection coefficient of the zeroth-order diffracted plane wave outside the photonic crystal. It is shown to be accurate for in-band applications, where the normalized frequency is low enough to ensure that the zeroth-order diffracted plane wave is the most important factor in determining the overall reflection. The frequency limitation of employing the proposed approach is explored, highly dispersive photonic crystals are considered, and wideband matching stages based on binomial impedance transformers are designed to work at the first two photonic bands.

  7. Vacuum Brazing of Accelerator Components

    NASA Astrophysics Data System (ADS)

    Singh, Rajvir; Pant, K. K.; Lal, Shankar; Yadav, D. P.; Garg, S. R.; Raghuvanshi, V. K.; Mundra, G.

    2012-11-01

    Commonly used materials for accelerator components are those which are vacuum compatible and thermally conductive. Stainless steel, aluminum and copper are common among them. Stainless steel is a poor heat conductor and not very common in use where good thermal conductivity is required. Aluminum and copper and their alloys meet the above requirements and are frequently used for the above purpose. The accelerator components made of aluminum and its alloys using welding process have become a common practice now a days. It is mandatory to use copper and its other grades in RF devices required for accelerators. Beam line and Front End components of the accelerators are fabricated from stainless steel and OFHC copper. Fabrication of components made of copper using welding process is very difficult and in most of the cases it is impossible. Fabrication and joining in such cases is possible using brazing process especially under vacuum and inert gas atmosphere. Several accelerator components have been vacuum brazed for Indus projects at Raja Ramanna Centre for Advanced Technology (RRCAT), Indore using vacuum brazing facility available at RRCAT, Indore. This paper presents details regarding development of the above mentioned high value and strategic components/assemblies. It will include basics required for vacuum brazing, details of vacuum brazing facility, joint design, fixturing of the jobs, selection of filler alloys, optimization of brazing parameters so as to obtain high quality brazed joints, brief description of vacuum brazed accelerator components etc.

  8. Overview spectra and axial distribution of spectral line intensities in a high-current vacuum arc with CuCr electrodes

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

    Lisnyak, M.; Pipa, A. V.; Gorchakov, S., E-mail: gorchakov@inp-greifswald.de, E-mail: weltmann@inp-greifswald.de

    2015-09-28

    Spectroscopic investigations of free-burning vacuum arcs in diffuse mode with CuCr electrodes are presented. The experimental conditions of the investigated arc correspond to the typical system for vacuum circuit breakers. Spectra of six species Cu I, Cu II, Cu III, Cr I, Cr II, and Cr III have been analyzed in the wavelength range 350–810 nm. The axial intensity distributions were found to be strongly dependent on the ionization stage of radiating species. Emission distributions of Cr II and Cu II can be distinguished as well as the distributions of Cr III and Cu III. Information on the axial distribution wasmore » used to identify the spectra and for identification of overlapping spectral lines. The overview spectra and some spectral windows recorded with high resolution are presented. Analysis of axial distributions of emitted light, which originates from different ionization states, is presented and discussed.« less

  9. High-voltage isolation transformer for sub-nanosecond rise time pulses constructed with annular parallel-strip transmission lines.

    PubMed

    Homma, Akira

    2011-07-01

    A novel annular parallel-strip transmission line was devised to construct high-voltage high-speed pulse isolation transformers. The transmission lines can easily realize stable high-voltage operation and good impedance matching between primary and secondary circuits. The time constant for the step response of the transformer was calculated by introducing a simple low-frequency equivalent circuit model. Results show that the relation between the time constant and low-cut-off frequency of the transformer conforms to the theory of the general first-order linear time-invariant system. Results also show that the test transformer composed of the new transmission lines can transmit about 600 ps rise time pulses across the dc potential difference of more than 150 kV with insertion loss of -2.5 dB. The measured effective time constant of 12 ns agreed exactly with the theoretically predicted value. For practical applications involving the delivery of synchronized trigger signals to a dc high-voltage electron gun station, the transformer described in this paper exhibited advantages over methods using fiber optic cables for the signal transfer system. This transformer has no jitter or breakdown problems that invariably occur in active circuit components.

  10. De-embedding technique for accurate modeling of compact 3D MMIC CPW transmission lines

    NASA Astrophysics Data System (ADS)

    Pohan, U. H.; KKyabaggu, P. B.; Sinulingga, E. P.

    2018-02-01

    Requirement for high-density and high-functionality microwave and millimeter-wave circuits have led to the innovative circuit architectures such as three-dimensional multilayer MMICs. The major advantage of the multilayer techniques is that one can employ passive and active components based on CPW technology. In this work, MMIC Coplanar Waveguide(CPW)components such as Transmission Line (TL) are modeled in their 3D layouts. Main characteristics of CPWTL suffered from the probe pads’ parasitic and resonant frequency effects have been studied. By understanding the parasitic effects, then the novel de-embedding technique are developed accurately in order to predict high frequency characteristics of the designed MMICs. The novel de-embedding technique has shown to be critical in reducing the probe pad parasitic significantly from the model. As results, high frequency characteristics of the designed MMICs have been presented with minimumparasitic effects of the probe pads. The de-embedding process optimises the determination of main characteristics of Compact 3D MMIC CPW transmission lines.

  11. Analysis of Operating Modes of Stand-Alone Series Controller of Power Flows for Overhead Power Transmission Lines

    NASA Astrophysics Data System (ADS)

    Astashev, M. G.; Panfilov, D. I.; Seregin, D. A.; Chernyshev, A. A.

    2017-12-01

    The features of using the bridge voltage inverter in small-size stand-alone series controllers of power flows (PFSC) for overhead power transmission lines (OPTL) are examined. The basic processes in the converter during transient and steady state modes were analyzed. The basic relations for calculating the electromagnetic processes taking into account the energy loss in the circuit and without it were received. A simulation model is proposed of a converter that makes it possible to study its operating modes during the formation of reactance introduced into the overhead power transmission line. The results of simulation of operating modes of the PFSC are presented.

  12. Monolithic high voltage nonlinear transmission line fabrication process

    DOEpatents

    Cooper, G.A.

    1994-10-04

    A process for fabricating sequential inductors and varistor diodes of a monolithic, high voltage, nonlinear, transmission line in GaAs is disclosed. An epitaxially grown laminate is produced by applying a low doped active n-type GaAs layer to an n-plus type GaAs substrate. A heavily doped p-type GaAs layer is applied to the active n-type layer and a heavily doped n-type GaAs layer is applied to the p-type layer. Ohmic contacts are applied to the heavily doped n-type layer where diodes are desired. Multiple layers are then either etched away or Oxygen ion implanted to isolate individual varistor diodes. An insulator is applied between the diodes and a conductive/inductive layer is thereafter applied on top of the insulator layer to complete the process. 6 figs.

  13. In-Containment Signal Acquisition and Data Transmission via Power Lines within High Dose Areas of Nuclear Power Plants

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

    Mueller Steffen; Wibbing Sascha; Weigel Robert

    2015-07-01

    Signal acquisition and data transmission for innovative sensor systems and networks inside the containment of nuclear power plants (NPPs) is still a challenge with respect to safety, performance, reliability, availability, and costs. This especially applies to equipment upgrades for existing plants, special measurements, but also for new builds. This paper presents a novel method for efficient and cost-effective sensor signal acquisition and data transmission via power lines, in order to cope with the disadvantages of common system architectures that often suffer from poor signal integrity due to raw data transmissions via long cables, huge efforts and costs for installation, andmore » low flexibility with respect to maintenance and upgrades. A transmitter-receiver architecture is proposed that allows multiplexing of multiple sensor inputs for unidirectional point-to-point transmission by superimposing information signals on existing AC or DC supply lines, but also on active and inactive sensor wires, or spare cables, using power line communication (PLC) technology. Based on commercial off-the-shelf (COTS) electronic parts, a radiation hard transmitter hardware is designed to operate in harsh environment within the containment during full plant operation. The system's modular approach allows application specific trade-offs between redundancy and throughput regarding data transmission, as well as various sensor input front-ends which are compatible with state of the art systems. PLC technology eliminates the need for costly installation of additional cables and wall penetrations, while providing a complementary and diverse communication technology for upgrades of existing systems. At the receiver side in low dose areas, signals are extracted from the power line, demodulated, and de-multiplexed, in order to regain the original sensor signal information and provide it either in analog or digital output format. Successful laboratory qualification tests, field trails

  14. Design of polarizers for a mega-watt long-pulse millimeter-wave transmission line on the large helical device.

    PubMed

    Ii, T; Kubo, S; Shimozuma, T; Kobayashi, S; Okada, K; Yoshimura, Y; Igami, H; Takahashi, H; Ito, S; Mizuno, Y; Okada, K; Makino, R; Kobayashi, K; Goto, Y; Mutoh, T

    2015-02-01

    The polarizer is one of the critical components in a high-power millimeter-wave transmission line. It requires full and highly efficient coverage of any polarization states, high-power tolerance, and low-loss feature. Polarizers with rounded shape at the edge of the periodic groove surface are designed and fabricated by the machining process for a mega-watt long-pulse millimeter-wave transmission line of the electron cyclotron resonance heating system in the large helical device. The groove shape of λ/8- and λ/4-type polarizers for an 82.7 GHz transmission line is optimally designed in an integral method developed in the vector theories of diffraction gratings so that the efficiency to realize any polarization state can be maximized. The dependence of the polarization states on the combination of the two polarizer rotation angles (Φλ/8, Φλ/4) is examined experimentally in a low-power test with the newly developed polarization monitor. The results show that the measured polarization characteristics are in good agreement with the calculated ones.

  15. Common raven occurrence in relation to energy transmission line corridors transiting human-altered sagebrush steppe

    USGS Publications Warehouse

    Coates, Peter S.; Howe, Kristy B.; Casazza, Michael L.; Delehanty, David J.

    2014-01-01

    Energy-related infrastructure and other human enterprises within sagebrush steppe of the American West often results in changes that promote common raven (Corvus corax; hereafter, raven) populations. Ravens, a generalist predator capable of behavioral innovation, present a threat to many species of conservation concern. We evaluate the effects of detailed features of an altered landscape on the probability of raven occurrence using extensive raven survey (n= 1045) and mapping data from southern Idaho, USA. We found nonlinear relationships between raven occurrence and distances to transmission lines, roads, and facilities. Most importantly, raven occurrence was greater with presence of transmission lines up to 2.2 km from the corridor.We further explain variation in raven occurrence along anthropogenic features based on the amount of non-native vegetation and cover type edge, such that ravens select fragmented sagebrush stands with patchy, exotic vegetative introgression. Raven occurrence also increased with greater length of edge formed by the contact of big sagebrush (Artemisia tridentate spp.) with non-native vegetation cover types. In consideration of increasing alteration of sagebrush steppe, these findings will be useful for planning energy transmission corridor placement and other management activities where conservation of sagebrush obligate species is a priority.

  16. 76 FR 34969 - Extension of Scoping Period for the Northern Pass Transmission Line Project Environmental Impact...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-15

    ... Transmission Line Project Environmental Impact Statement (EIS) (DOE/EIS-0463). In anticipation of additional... anticipation of this information, DOE is reopening the public scoping period for an indefinite period. DOE will...

  17. Analysis of the ITER low field side reflectometer transmission line system.

    PubMed

    Hanson, G R; Wilgen, J B; Bigelow, T S; Diem, S J; Biewer, T M

    2010-10-01

    A critical issue in the design of the ITER low field side reflectometer is the transmission line (TL) system. A TL connects each launcher to a diagnostic instrument. Each TL will typically consist of ∼42 m of corrugated waveguide and up to ten miter bends. Important issues for the performance of the TL system are mode conversion and reflections. Minimizing these issues are critical to minimizing standing waves and phase errors. The performance of TL system is analyzed and recommendations are given.

  18. Nitrogen gas propagation in a liquid helium cooled vacuum tube following a sudden vacuum loss

    NASA Astrophysics Data System (ADS)

    Dhuley, R. C.; Van Sciver, S. W.

    2017-02-01

    We present experimental measurements and analysis of propagation of the nitrogen gas that was vented to a high vacuum tube immersed in liquid helium (LHe). The scenario resembles accidental venting of atmospheric air to a SRF beam-line and was investigated to understand how the in-flowing air would propagate in such geometry. The gas front propagation speed in the tube was measured using pressure probes and thermometers installed at regular intervals over the tube length. The experimental data show the front speed to decrease along the vacuum tube. The empirical and analytical models developed to characterize the front deceleration are summarized.

  19. Optimization of a vacuum chamber for vibration measurements.

    PubMed

    Danyluk, Mike; Dhingra, Anoop

    2011-10-01

    A 200 °C high vacuum chamber has been built to improve vibration measurement sensitivity. The optimized design addresses two significant issues: (i) vibration measurements under high vacuum conditions and (ii) use of design optimization tools to reduce operating costs. A test rig consisting of a cylindrical vessel with one access port has been constructed with a welded-bellows assembly used to seal the vessel and enable vibration measurements in high vacuum that are comparable with measurements in air. The welded-bellows assembly provides a force transmissibility of 0.1 or better at 15 Hz excitation under high vacuum conditions. Numerical results based on design optimization of a larger diameter chamber are presented. The general constraints on the new design include material yield stress, chamber first natural frequency, vibration isolation performance, and forced convection heat transfer capabilities over the exterior of the vessel access ports. Operating costs of the new chamber are reduced by 50% compared to a preexisting chamber of similar size and function.

  20. Seasonal Patterns of Melatonin, Cortisol, and Progesterone Secretion in Female Lambs Raised Beneath a 500-KV Transmission Line

    NASA Astrophysics Data System (ADS)

    Lee, Jack Monroe, Jr.

    There is ongoing controversy about the possibility of adverse biological effects from environmental exposures to electric and magnetic fields. These fields are produced by all electrical equipment and appliances including electrical transmission lines. The objective of this environmental science study was to investigate the possible effects of a high voltage transmission line on domestic sheep (Ovis aries L.), a species that can often be found near such lines. The study was primarily designed to determine whether a specific effect of electric and magnetic fields found in laboratory animals also occurs in livestock under natural environmental conditions. The effect is the ability of fields, at levels found in the environment, to significantly depress the normally high nocturnal concentrations of the pineal hormone-melatonin. Ten female Suffolk lambs were penned for 10 months directly beneath a 500-kV transmission line near Estacada, Oregon. Ten other lambs of the same type were penned in a control area away from the transmission line where electric and magnetic fields were at ambient levels. Serum melatonin was analyzed by radioimmunoassay (RIA) from 6618 blood samples collected at 0.5 to 3-hour intervals over eight 48-hour periods. Serum progesterone was analyzed by RIA from blood samples collected twice weekly. Serum cortisol was also assayed by RIA from the blood samples collected during the 48-hour samples. Results showed that lambs in both the control and line groups had the typical pattern of melatonin secretion consisting of low daytime and high nighttime serum concentrations. There were no statistically significant differences between groups in melatonin levels, or in the phase or duration of the nighttime melatonin elevation. Age at puberty and number of reproductive cycles also did not differ between groups. Serum cortisol showed a circadian rhythm with highest concentrations during the day. There were, however, no differences in cortisol concentrations

  1. Particle trap with dielectric barrier for use in gas insulated transmission lines

    DOEpatents

    Dale, Steinar J.

    1982-01-01

    A gas-insulated transmission line includes an outer sheath, an inner conductor within the outer sheath, insulating supports supporting the inner conductor within the outer sheath, and an insulating gas electrically insulating the inner conductor from the outer sheath. An apertured particle trapping electrode is disposed within the outer sheath, and the electrode has a pair of dielectric members secured at each longitudinal end thereof, with the dielectric members extending outwardly from the apertured electrode.

  2. A transmission line model for propagation in elliptical core optical fibers

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

    Georgantzos, E.; Boucouvalas, A. C.; Papageorgiou, C.

    The calculation of mode propagation constants of elliptical core fibers has been the purpose of extended research leading to many notable methods, with the classic step index solution based on Mathieu functions. This paper seeks to derive a new innovative method for the determination of mode propagation constants in single mode fibers with elliptic core by modeling the elliptical fiber as a series of connected coupled transmission line elements. We develop a matrix formulation of the transmission line and the resonance of the circuits is used to calculate the mode propagation constants. The technique, used with success in the casemore » of cylindrical fibers, is now being extended for the case of fibers with elliptical cross section. The advantage of this approach is that it is very well suited to be able to calculate the mode dispersion of arbitrary refractive index profile elliptical waveguides. The analysis begins with the deployment Maxwell’s equations adjusted for elliptical coordinates. Further algebraic analysis leads to a set of equations where we are faced with the appearance of harmonics. Taking into consideration predefined fixed number of harmonics simplifies the problem and enables the use of the resonant circuits approach. According to each case, programs have been created in Matlab, providing with a series of results (mode propagation constants) that are further compared with corresponding results from the ready known Mathieu functions method.« less

  3. Simplified method to solve sound transmission through structures lined with elastic porous material.

    PubMed

    Lee, J H; Kim, J

    2001-11-01

    An approximate analysis method is developed to calculate sound transmission through structures lined with porous material. Because the porous material has both the solid phase and fluid phase, three wave components exist in the material, which makes the related analysis very complicated. The main idea in developing the approximate method is very simple: modeling the porous material using only the strongest of the three waves, which in effect idealizes the material as an equivalent fluid. The analysis procedure has to be conducted in two steps. In the first step, sound transmission through a flat double panel with a porous liner of infinite extents, which has the same cross sectional construction as the actual structure, is solved based on the full theory and the strongest wave component is identified. In the second step sound transmission through the actual structure is solved modeling the porous material as an equivalent fluid while using the actual geometry of the structure. The development and validation of the method are discussed in detail. As an application example, the transmission loss through double walled cylindrical shells with a porous core is calculated utilizing the simplified method.

  4. Study on Construction Technology Standardization of Primary Guide Rope Laying by Multi-rotor Aircraft in Stringing Construction of Transmission Line

    NASA Astrophysics Data System (ADS)

    Liu, Chen; Tang, Guang-Rui; Jiang, Ming; Dong, Yu-Ming

    2017-09-01

    According to the practical situation of stringing construction for Ultra High Voltage (UHV) overhead transmission line, construction technology standardization of primary guide rope laying by multi-rotor aircraft is studied. This paper mainly focuses on the construction preparation, test flight and technology of laying primary guide rope. The summary of the construction technology standardization of primary guide rope laying by multi-rotor aircraft in stringing construction are useful in further guiding practical construction of transmission line.

  5. Flexible gas insulated transmission line having regions of reduced electric field

    DOEpatents

    Cookson, Alan H.; Fischer, William H.; Yoon, Kue H.; Meyer, Jeffry R.

    1983-01-01

    A gas insulated transmission line having radially flexible field control means for reducing the electric field along the periphery of the inner conductor at predetermined locations wherein the support insulators are located. The radially flexible field control means of the invention includes several structural variations of the inner conductor, wherein careful controlling of the length to depth of surface depressions produces regions of reduced electric field. Several embodiments of the invention dispose a flexible connector at the predetermined location along the inner conductor where the surface depressions that control the reduced electric field are located.

  6. Two methods for transmission line simulation model creation based on time domain measurements

    NASA Astrophysics Data System (ADS)

    Rinas, D.; Frei, S.

    2011-07-01

    The emission from transmission lines plays an important role in the electromagnetic compatibility of automotive electronic systems. In a frequency range below 200 MHz radiation from cables is often the dominant emission factor. In higher frequency ranges radiation from PCBs and their housing becomes more relevant. Main sources for this emission are the conducting traces. The established field measurement methods according CISPR 25 for evaluation of emissions suffer from the need to use large anechoic chambers. Furthermore measurement data can not be used for simulation model creation in order to compute the overall fields radiated from a car. In this paper a method to determine the far-fields and a simulation model of radiating transmission lines, esp. cable bundles and conducting traces on planar structures, is proposed. The method measures the electromagnetic near-field above the test object. Measurements are done in time domain in order to get phase information and to reduce measurement time. On the basis of near-field data equivalent source identification can be done. Considering correlations between sources along each conductive structure in model creation process, the model accuracy increases and computational costs can be reduced.

  7. Particle trap with dielectric barrier for use in gas insulated transmission lines

    DOEpatents

    Dale, S.J.

    1982-06-15

    A gas-insulated transmission line includes an outer sheath, an inner conductor within the outer sheath, insulating supports supporting the inner conductor within the outer sheath, and an insulating gas electrically insulating the inner conductor from the outer sheath. An apertured particle trapping electrode is disposed within the outer sheath, and the electrode has a pair of dielectric members secured at each longitudinal end thereof, with the dielectric members extending outwardly from the apertured electrode. 7 figs.

  8. Dynamics of periodic spring-mass chain coupled with an electric transmission line

    NASA Astrophysics Data System (ADS)

    Belloni, Edoardo; Cenedese, Mattia; Braghin, Francesco

    2017-04-01

    Periodic structures have received large interest due to their peculiar behavior: they have band gaps, that is portions of the frequency response along with any wave incoming in the structure is reflected. Numerous are the applications, like metamaterials and locally resonant structures. Nowadays, new possibilities could come from mechanical periodic structures that are connected to an electrical transmission line, periodic in turn. Starting from this idea, this paper analyses ideal a mono-atomic spring-mass chain, considering the springs connected to a periodic electric network, composed by inductances (and resistors): these simple examples will show how the frequency response is affected. In particular, the mutual influence between the electric and mechanical domain is highlighted, and the contribution of parameters on band gap positioning and design is explored. Details are provided about vibration modes and wave transmission.

  9. Viral contacts confound studies of childhood leukemia and high-voltage transmission lines.

    PubMed

    Sahl, J D

    1994-05-01

    Studies of childhood leukemia have reported a link with residential proximity to electric utility facilities. This paper elaborates on the hypothesis that residential proximity to electric utility transmission-systems is a surrogate for viral contacts, a potential confounder in these studies. While the causal implications of increased viral contacts is not established, the assumption made here is that a significant component of childhood leukemia has an infectious etiology. Increased viral contacts can result from residential mobility, being first born, or use of community childcare facilities. Re-analysis of existing studies should look specifically for the interaction between childhood leukemia, markers for viral contacts (e.g., residential mobility, birth order, use of outside childcare facilities), and residential proximity to high-voltage transmission lines. New study designs should include parameters to test directly for a virus-related infectious model for childhood leukemia.

  10. Pattern Recognition Application of Support Vector Machine for Fault Classification of Thyristor Controlled Series Compensated Transmission Lines

    NASA Astrophysics Data System (ADS)

    Yashvantrai Vyas, Bhargav; Maheshwari, Rudra Prakash; Das, Biswarup

    2016-06-01

    Application of series compensation in extra high voltage (EHV) transmission line makes the protection job difficult for engineers, due to alteration in system parameters and measurements. The problem amplifies with inclusion of electronically controlled compensation like thyristor controlled series compensation (TCSC) as it produce harmonics and rapid change in system parameters during fault associated with TCSC control. This paper presents a pattern recognition based fault type identification approach with support vector machine. The scheme uses only half cycle post fault data of three phase currents to accomplish the task. The change in current signal features during fault has been considered as discriminatory measure. The developed scheme in this paper is tested over a large set of fault data with variation in system and fault parameters. These fault cases have been generated with PSCAD/EMTDC on a 400 kV, 300 km transmission line model. The developed algorithm has proved better for implementation on TCSC compensated line with its improved accuracy and speed.

  11. A hybrid Boundary Element Unstructured Transmission-line (BEUT) method for accurate 2D electromagnetic simulation

    NASA Astrophysics Data System (ADS)

    Simmons, Daniel; Cools, Kristof; Sewell, Phillip

    2016-11-01

    Time domain electromagnetic simulation tools have the ability to model transient, wide-band applications, and non-linear problems. The Boundary Element Method (BEM) and the Transmission Line Modeling (TLM) method are both well established numerical techniques for simulating time-varying electromagnetic fields. The former surface based method can accurately describe outwardly radiating fields from piecewise uniform objects and efficiently deals with large domains filled with homogeneous media. The latter volume based method can describe inhomogeneous and non-linear media and has been proven to be unconditionally stable. Furthermore, the Unstructured TLM (UTLM) enables modelling of geometrically complex objects by using triangular meshes which removes staircasing and unnecessary extensions of the simulation domain. The hybridization of BEM and UTLM which is described in this paper is named the Boundary Element Unstructured Transmission-line (BEUT) method. It incorporates the advantages of both methods. The theory and derivation of the 2D BEUT method is described in this paper, along with any relevant implementation details. The method is corroborated by studying its correctness and efficiency compared to the traditional UTLM method when applied to complex problems such as the transmission through a system of Luneburg lenses and the modelling of antenna radomes for use in wireless communications.

  12. Mode and climatic factors effect on energy losses in transient heat modes of transmission lines

    NASA Astrophysics Data System (ADS)

    Bigun, A. Ya; Sidorov, O. A.; Osipov, D. S.; Girshin, S. S.; Goryunov, V. N.; Petrova, E. V.

    2018-01-01

    Electrical energy losses increase in modern grids. The losses are connected with an increase in consumption. Existing models of electric power losses estimation considering climatic factors do not allow estimating the cable temperature in real time. Considering weather and mode factors in real time allows to meet effectively and safely the consumer’s needs to minimize energy losses during transmission, to use electric power equipment effectively. These factors increase an interest in the evaluation of the dynamic thermal mode of overhead transmission lines conductors. The article discusses an approximate analytic solution of the heat balance equation in the transient operation mode of overhead lines based on the least squares method. The accuracy of the results obtained is comparable with the results of solving the heat balance equation of transient thermal mode with the Runge-Kutt method. The analysis of mode and climatic factors effect on the cable temperature in a dynamic thermal mode is presented. The calculation of the maximum permissible current for variation of weather conditions is made. The average electric energy losses during the transient process are calculated with the change of wind, air temperature and solar radiation. The parameters having the greatest effect on the transmission capacity are identified.

  13. A hybrid Boundary Element Unstructured Transmission-line (BEUT) method for accurate 2D electromagnetic simulation

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

    Simmons, Daniel, E-mail: daniel.simmons@nottingham.ac.uk; Cools, Kristof; Sewell, Phillip

    Time domain electromagnetic simulation tools have the ability to model transient, wide-band applications, and non-linear problems. The Boundary Element Method (BEM) and the Transmission Line Modeling (TLM) method are both well established numerical techniques for simulating time-varying electromagnetic fields. The former surface based method can accurately describe outwardly radiating fields from piecewise uniform objects and efficiently deals with large domains filled with homogeneous media. The latter volume based method can describe inhomogeneous and non-linear media and has been proven to be unconditionally stable. Furthermore, the Unstructured TLM (UTLM) enables modelling of geometrically complex objects by using triangular meshes which removesmore » staircasing and unnecessary extensions of the simulation domain. The hybridization of BEM and UTLM which is described in this paper is named the Boundary Element Unstructured Transmission-line (BEUT) method. It incorporates the advantages of both methods. The theory and derivation of the 2D BEUT method is described in this paper, along with any relevant implementation details. The method is corroborated by studying its correctness and efficiency compared to the traditional UTLM method when applied to complex problems such as the transmission through a system of Luneburg lenses and the modelling of antenna radomes for use in wireless communications. - Graphical abstract:.« less

  14. Gas insulated transmission line having low inductance intercalated sheath

    DOEpatents

    Cookson, Alan H.

    1978-01-01

    A gas insulated transmission line including an outer sheath, an inner conductor disposed within the outer sheath, and an insulating gas between the inner conductor and the outer sheath. The outer sheath comprises an insulating tube having first and second ends, and having interior and exterior surfaces. A first electrically conducting foil is secured to the interior surface of the insulating tube, is spirally wound from one tube end to the second tube end, and has a plurality of overlapping turns. A second electrically conducting foil is secured to the exterior surface of the insulating tube, and is spirally wound in the opposite direction from the first electrically conducting foil. By winding the foils in opposite directions, the inductances within the intercalated sheath will cancel each other out.

  15. High current nonlinear transmission line based electron beam driver

    NASA Astrophysics Data System (ADS)

    Hoff, B. W.; French, D. M.; Simon, D. S.; Lepell, P. D.; Montoya, T.; Heidger, S. L.

    2017-10-01

    A gigawatt-class nonlinear transmission line based electron beam driver is experimentally demonstrated. Four experimental series, each with a different Marx bank charge voltage (15, 20, 25, and 30 kV), were completed. Within each experimental series, shots at peak frequencies ranging from 950 MHz to 1.45 GHz were performed. Peak amplitude modulations of the NLTL output voltage signal were found to range between 18% and 35% for the lowest frequency shots and between 5% and 20% for the highest frequency shots (higher modulation at higher Marx charge voltage). Peak amplitude modulations of the electron beam current were found to range between 10% and 20% for the lowest frequency shots and between 2% and 7% for the highest frequency shots (higher modulation at higher Marx charge voltage).

  16. Theoretical investigation of dielectric corona pre-ionization TEA nitrogen laser based on transmission line method

    NASA Astrophysics Data System (ADS)

    Bahrampour, Alireza; Fallah, Robabeh; Ganjovi, Alireza A.; Bahrampour, Abolfazl

    2007-07-01

    This paper models the dielectric corona pre-ionization, capacitor transfer type of flat-plane transmission line traveling wave transverse excited atmospheric pressure nitrogen laser by a non-linear lumped RLC electric circuit. The flat-plane transmission line and the pre-ionizer dielectric are modeled by a lumped linear RLC and time-dependent non-linear RC circuit, respectively. The main discharge region is considered as a time-dependent non-linear RLC circuit where its resistance value is also depends on the radiated pre-ionization ultra violet (UV) intensity. The UV radiation is radiated by the resistance due to the surface plasma on the pre-ionizer dielectric. The theoretical predictions are in a very good agreement with the experimental observations. The electric circuit equations (including the ionization rate equations), the equations of laser levels population densities and propagation equation of laser intensities, are solved numerically. As a result, the effects of pre-ionizer dielectric parameters on the electrical behavior and output laser intensity are obtained.

  17. Characteristics of a large vacuum wave precursor on the SABRE voltage adder MITL and extraction ion diode

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

    Cuneo, M.E.; Hanson, D.L.; Menge, P.R.

    SABRE (Sandia Accelerator and Beam Research Experiment) is a ten-cavity linear induction magnetically insulated voltage adder (6 MV, 300 kA) operated in positive polarity to investigate issues relevant to ion beam production and propagation for inertial confinement fusion. The voltage adder section is coupled to an applied-B extraction ion diode via a long coaxial output transmission line. Observations indicate that the power propagates in a vacuum wave prior to electron emission. After the electron emission threshold is reached, power propagates in a magnetically insulated wave. The precursor is observed to have a dominant impact on he turn-on, impedance history, andmore » beam characteristics of applied-B ion diodes since the precursor voltage is large enough to cause electron emission at the diode from both the cathode feed and cathode tips. The amplitude of the precursor at the load (3--4.5 MV) is a significant fraction of the maximum load voltage (5--6 MV) because (1) the transmission line gaps ( {approx} 9 cm at output) and therefore impedances are relatively large, and hence the electric field threshold for electron emission (200 to 300 kV/cm) is not reached until well into the power pulse rise time; and (2) the rapidly falling forward wave and diode impedance reduces the ratio of main pulse voltage to precursor voltage. Experimental voltage and current data from the transmission line and the ion diode will be presented and compared with TWOQUICK (2-D electromagnetic PIC code) simulations and analytic models.« less

  18. Horizontal cryogenic bushing for the termination of a superconducting power-transmission line

    DOEpatents

    Minati, K.F.; Morgan, G.H.; McNerney, A.J.; Schauer, F.

    1982-07-29

    A termination for a superconducting power transmission line is disclosed which is comprised of a standard air entrance insulated vertical bushing with an elbow, a horizontal cryogenic bushing linking the pressurized cryogenic cable environment to the ambient temperature bushing and a stress cone which terminated the cable outer shield and transforms the large radial voltage gradient in the cable dielectric into a much lower radial voltage gradient in the high density helium coolant at the cold end of the cryogenic bushing.

  19. Termination for a superconducting power transmission line including a horizontal cryogenic bushing

    DOEpatents

    Minati, Kurt F.; Morgan, Gerry H.; McNerney, Andrew J.; Schauer, Felix

    1984-01-01

    A termination for a superconducting power transmission line is disclosed which is comprised of a standard air entrance insulated vertical bushing with an elbow, a horizontal cryogenic bushing linking the pressurized cryogenic cable environment to the ambient temperature bushing and a stress cone which terminates the cable outer shield and transforms the large radial voltage gradient in the cable dielectric into a much lower radial voltage gradient in the high density helium coolant at the cold end of the cryogenic bushing.

  20. Two-Port Representation of a Linear Transmission Line in the Time Domain.

    DTIC Science & Technology

    1980-01-01

    which is a rational function. To use the Prony procedure it is necessary to inverse transform the admittance functions. For the transmission line, most...impulse is a constant, the inverse transform of Y0(s) contains an impulse of value ._ Therefore, if we were to numerically inverse transform Yo(s), we...would remove this im- pulse and inverse transform Y-(S) Y (S) 1’LR+C~ (23) The prony procedure would then be applied to the result. Of course, an impulse

  1. Parallel-plate transmission line type of EMP simulators: Systematic review and recommendations

    NASA Astrophysics Data System (ADS)

    Giri, D. V.; Liu, T. K.; Tesche, F. M.; King, R. W. P.

    1980-05-01

    This report presents various aspects of the two-parallel-plate transmission line type of EMP simulator. Much of the work is the result of research efforts conducted during the last two decades at the Air Force Weapons Laboratory, and in industries/universities as well. The principal features of individual simulator components are discussed. The report also emphasizes that it is imperative to hybridize our understanding of individual components so that we can draw meaningful conclusions of simulator performance as a whole.

  2. 33 CFR 165.T13-149 - Safety Zone; McNary-John Day Transmission Line Project, Columbia River, Hermiston, OR.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Transmission Line Project, Columbia River, Hermiston, OR. 165.T13-149 Section 165.T13-149 Navigation and... Project, Columbia River, Hermiston, OR. (a) Location: The following is a safety zone: All waters of the Columbia River between two lines with the first line starting at the north bank at 45° 56′ 16.5″ N/119° 19...

  3. Gas propagation in a liquid helium cooled vacuum tube following a sudden vacuum loss

    NASA Astrophysics Data System (ADS)

    Dhuley, Ram C.

    This dissertation describes the propagation of near atmospheric nitrogen gas that rushes into a liquid helium cooled vacuum tube after the tube suddenly loses vacuum. The loss-of-vacuum scenario resembles accidental venting of atmospheric air to the beam-line of a superconducting radio frequency particle accelerator and is investigated to understand how in the presence of condensation, the in-flowing air will propagate in such geometry. In a series of controlled experiments, room temperature nitrogen gas (a substitute for air) at a variety of mass flow rates was vented to a high vacuum tube immersed in a bath of liquid helium. Pressure probes and thermometers installed on the tube along its length measured respectively the tube pressure and tube wall temperature rise due to gas flooding and condensation. At high mass in-flow rates a gas front propagated down the vacuum tube but with a continuously decreasing speed. Regression analysis of the measured front arrival times indicates that the speed decreases nearly exponentially with the travel length. At low enough mass in-flow rates, no front propagated in the vacuum tube. Instead, the in-flowing gas steadily condensed over a short section of the tube near its entrance and the front appeared to `freeze-out'. An analytical expression is derived for gas front propagation speed in a vacuum tube in the presence of condensation. The analytical model qualitatively explains the front deceleration and flow freeze-out. The model is then simplified and supplemented with condensation heat/mass transfer data to again find the front to decelerate exponentially while going away from the tube entrance. Within the experimental and procedural uncertainty, the exponential decay length-scales obtained from the front arrival time regression and from the simplified model agree.

  4. Attenuation of epsilon(sub eff) of coplanar waveguide transmission lines on silicon substrates

    NASA Technical Reports Server (NTRS)

    Taub, Susan R.; Young, Paul G.

    1993-01-01

    Attenuation and epsilon(sub eff) of Coplanar Waveguide (CPW) transmission lines were measured on Silicon substrates with resistivities ranging from 400 to greater than 30,000 ohm-cm, that have a 1000 angstrom coating of SiO2. Both attenuation and epsilon(sub eff) are given over the frequency range 5 to 40 GHz for various strip and slot widths. These measured values are also compared to the theoretical values.

  5. Evaluation of the probability of arrester failure in a high-voltage transmission line using a Q learning artificial neural network model

    NASA Astrophysics Data System (ADS)

    Ekonomou, L.; Karampelas, P.; Vita, V.; Chatzarakis, G. E.

    2011-04-01

    One of the most popular methods of protecting high voltage transmission lines against lightning strikes and internal overvoltages is the use of arresters. The installation of arresters in high voltage transmission lines can prevent or even reduce the lines' failure rate. Several studies based on simulation tools have been presented in order to estimate the critical currents that exceed the arresters' rated energy stress and to specify the arresters' installation interval. In this work artificial intelligence, and more specifically a Q-learning artificial neural network (ANN) model, is addressed for evaluating the arresters' failure probability. The aims of the paper are to describe in detail the developed Q-learning ANN model and to compare the results obtained by its application in operating 150 kV Greek transmission lines with those produced using a simulation tool. The satisfactory and accurate results of the proposed ANN model can make it a valuable tool for designers of electrical power systems seeking more effective lightning protection, reducing operational costs and better continuity of service.

  6. Requirements for self-magnetically insulated transmission lines

    DOE PAGES

    VanDevender, J. Pace; Pointon, Timothy D.; Seidel, David B.; ...

    2015-03-01

    Self-magnetically insulated transmission lines (MITLs) connect pulsed-power drivers with a load. Although the technology was originally developed in the 1970s and is widely used today in super power generators, failure of the technology is the principal limitation on the power that can be delivered to an experiment. We address issues that are often overlooked, rejected after inadequate simulations, or covered by overly conservative assumptions: (i) electron retrapping in coupling MITLs to loads, (ii) the applicability of collisionless versus collisional electron flow, (iii) power transport efficiency as a function of the geometry at the beginning of the MITL, (iv) gap closuremore » and when gap closure can be neglected, and (v) the role of negative ions in causing anode plasmas and enhancing current losses. We suggest a practical set of conservative design requirements for self-magnetically insulated electron flow based on the results discussed in this paper and on previously published results. The requirements are not necessarily severe constraints in all MITL applications; however, each of the 18 suggested requirements should be examined in the design of a MITL and in the investigation of excessive losses.« less

  7. 13. Building H9; view of stainless steel probes and vacuum ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. Building H-9; view of stainless steel probes and vacuum line, looking W. (Ryan and Harms) - Holston Army Ammunition Plant, RDX-and-Composition-B Manufacturing Line 9, Kingsport, Sullivan County, TN

  8. 76 FR 72001 - Draft Environmental Impact Statement for the Susquehanna to Roseland 500-kilovolt Transmission Line

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-21

    ... Park Service, Interior. ACTION: Notice of Availability. SUMMARY: The National Park Service announces the availability of the draft environmental impact statement for the Susquehanna to Roseland 500-kilovolt transmission line, which will affect the Appalachian National Scenic Trail, Delaware Water Gap...

  9. Wideband Isolation by Frequency Conversion in a Josephson-Junction Transmission Line

    NASA Astrophysics Data System (ADS)

    Ranzani, Leonardo; Kotler, Shlomi; Sirois, Adam J.; DeFeo, Michael P.; Castellanos-Beltran, Manuel; Cicak, Katarina; Vale, Leila R.; Aumentado, José

    2017-11-01

    Nonreciprocal transmission and isolation at microwave frequencies are important in many practical applications. In particular, compact isolators are useful in protecting sensitive quantum circuits operating at cryogenic temperatures from amplifier backaction and other environmental noise such as black-body radiation from higher temperature stages. However, the size of commercial cryogenic isolators limits the ability to measure multiple quantum circuits because of space constraints in typical dilution refrigerator systems. Furthermore, isolators usually require the use of ferrite components that cannot be integrated at the chip level and, since they also need large biasing magnetic fields, are incompatible with superconducting quantum circuits. In this work we show one way to accomplish isolation in a superconducting chip-scale device, a traveling-wave unidirectional frequency converter based on a parametrically pumped superconducting Josephson-junction transmission line, demonstrating better than 4.8 dB of inferred signal isolation from 6.6 to 11.4 GHz, with a maximum of 12 dB at 9.5 GHz. By using frequency diplexing techniques a conventional isolator could be implemented over this bandwidth.

  10. 77 FR 41369 - Dairyland Power Cooperative: CapX 2020 Hampton-Rochester-La Crosse Transmission Line Project

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-13

    ... DEPARTMENT OF AGRICULTURE Rural Utilities Service Dairyland Power Cooperative: CapX 2020 Hampton-Rochester-La Crosse Transmission Line Project AGENCY: Rural Utilities Service, USDA. ACTION: Notice of Availability of a Final Environmental Impact Statement. SUMMARY: Notice is hereby given that the Rural...

  11. 76 FR 78235 - Dairyland Power Cooperative: CapX 2020 Hampton-Rochester-La Crosse Transmission Line Project

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-16

    ... DEPARTMENT OF AGRICULTURE Rural Utilities Service Dairyland Power Cooperative: CapX 2020 Hampton-Rochester-La Crosse Transmission Line Project AGENCY: Rural Utilities Service, USDA. ACTION: Notice of Availability of a Draft Environmental Impact Statement and Notice of Public Hearings. SUMMARY: Notice is hereby...

  12. 77 FR 2268 - Dairyland Power Cooperative: CapX 2020 Hampton-Rochester-La Crosse Transmission Line Project

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-17

    ... DEPARTMENT OF AGRICULTURE Rural Utilities Service Dairyland Power Cooperative: CapX 2020 Hampton-Rochester-La Crosse Transmission Line Project AGENCY: Rural Utilities Service, USDA. ACTION: Notice of intent to extend public comment period for a Draft Environmental Impact Statement. SUMMARY: Notice is...

  13. The trophic vacuum and the evolution of complex life cycles in trophically transmitted helminths

    PubMed Central

    Benesh, Daniel P.; Chubb, James C.; Parker, Geoff A.

    2014-01-01

    Parasitic worms (helminths) frequently have complex life cycles in which they are transmitted trophically between two or more successive hosts. Sexual reproduction often takes place in high trophic-level (TL) vertebrates, where parasites can grow to large sizes with high fecundity. Direct infection of high TL hosts, while advantageous, may be unachievable for parasites constrained to transmit trophically, because helminth propagules are unlikely to be ingested by large predators. Lack of niche overlap between propagule and definitive host (the trophic transmission vacuum) may explain the origin and/or maintenance of intermediate hosts, which overcome this transmission barrier. We show that nematodes infecting high TL definitive hosts tend to have more successive hosts in their life cycles. This relationship was modest, though, driven mainly by the minimum TL of hosts, suggesting that the shortest trophic chains leading to a host define the boundaries of the transmission vacuum. We also show that alternative modes of transmission, like host penetration, allow nematodes to reach high TLs without intermediate hosts. We suggest that widespread omnivory as well as parasite adaptations to increase transmission probably reduce, but do not eliminate, the barriers to the transmission of helminths through the food web. PMID:25209937

  14. Secure and Time-Aware Communication of Wireless Sensors Monitoring Overhead Transmission Lines.

    PubMed

    Mazur, Katarzyna; Wydra, Michal; Ksiezopolski, Bogdan

    2017-07-11

    Existing transmission power grids suffer from high maintenance costs and scalability issues along with a lack of effective and secure system monitoring. To address these problems, we propose to use Wireless Sensor Networks (WSNs) as a technology to achieve energy efficient, reliable, and low-cost remote monitoring of transmission grids. With WSNs, smart grid enables both utilities and customers to monitor, predict and manage energy usage effectively and react to possible power grid disturbances in a timely manner. However, the increased application of WSNs also introduces new security challenges, especially related to privacy, connectivity, and security management, repeatedly causing unpredicted expenditures. Monitoring the status of the power system, a large amount of sensors generates massive amount of sensitive data. In order to build an effective Wireless Sensor Network (WSN) for a smart grid, we focus on designing a methodology of efficient and secure delivery of the data measured on transmission lines. We perform a set of simulations, in which we examine different routing algorithms, security mechanisms and WSN deployments in order to select the parameters that will not affect the delivery time but fulfill their role and ensure security at the same time. Furthermore, we analyze the optimal placement of direct wireless links, aiming at minimizing time delays, balancing network performance and decreasing deployment costs.

  15. Method and apparatus for magnetic resonance imaging and spectroscopy using microstrip transmission line coils

    DOEpatents

    Zhang, Xiaoliang; Ugurbil, Kamil; Chen, Wei

    2006-04-04

    Apparatus and method for MRI imaging using a coil constructed of microstrip transmission line (MTL coil) are disclosed. In one method, a target is positioned to be imaged within the field of a main magnetic field of a magnet resonance imaging (MRI) system, a MTL coil is positioned proximate the target, and a MRI image is obtained using the main magnet and the MTL coil. In another embodiment, the MRI coil is used for spectroscopy. MRI imaging and spectroscopy coils are formed using microstrip transmission line. These MTL coils have the advantageous property of good performance while occupying a relatively small space, thus allowing MTL coils to be used inside restricted areas more easily than some other prior art coils. In addition, the MTL coils are relatively simple to construct of inexpensive components and thus relatively inexpensive compared to other designs. Further, the MTL coils of the present invention can be readily formed in a wide variety of coil configurations, and used in a wide variety of ways. Further, while the MTL coils of the present invention work well at high field strengths and frequencies, they also work at low frequencies and in low field strengths as well.

  16. Overhead electric power transmission line jumpering system for bundles of five or more subconductors

    DOEpatents

    Winkelman, Paul F.

    1982-01-01

    Jumpering of electric power transmission lines at a dead end tower. Two transmission line conductor bundles each contain five or more spaced apart subconductors (5) arranged in the shape of a cylinder having a circular cross section. The ends of each bundle of subconductors are attached with insulators to a dead end tower (1). Jumpering allows the electric current to flow between the two bundles of subconductors using jumper buses, internal jumper conductors, and external jumper conductors. One or more current collecting jumper buses (37) are located inside each bundle of subconductors with each jumper bus being attached to the end of a subconductor. Small-diameter internal jumper conductors (33) are located in the inherently electrically shielded area inside each bundle of subconductors with each subconductor (except ones having an attached jumper bus) having one internal jumper conductor connected between that subconductor's end and a jumper bus. Large-diameter external jumper conductors (9) are located outside each bundle of subconductors with one or more external jumper conductors being connected between the jumper buses in one bundle of subconductors and the jumper buses in the other bundle.

  17. ULTRA HIGH VACUUM VALVE

    DOEpatents

    Fry, W.A.

    1962-05-29

    A valve for high vacuum applications such as the CStellarator where chamber pressures as low as 2 x 10/sup -10/ mm Hg are necessary is designed with a line-of-sight path through the valve for visual inspection of the contents of reactants in such chambers. The valve comprises a turnable resilient metal ball having an aperture therethrough, means for selectively turning the ball to rotate the axis of its line-of-sight path, and soft, deformable opposing orifices that are movable relatively toward said ball to seal with opposite ball surfaces upon said movement of said axis of said line-of-sight path. The valve also includes a bellows seal connected between said orifices and internal actuating means that eliminates the requirement for gasketed turnable valve closing stems. (AEC)

  18. Acoustic solitons in waveguides with Helmholtz resonators: transmission line approach.

    PubMed

    Achilleos, V; Richoux, O; Theocharis, G; Frantzeskakis, D J

    2015-02-01

    We report experimental results and study theoretically soliton formation and propagation in an air-filled acoustic waveguide side loaded with Helmholtz resonators. We propose a theoretical modeling of the system, which relies on a transmission-line approach, leading to a nonlinear dynamical lattice model. The latter allows for an analytical description of the various soliton solutions for the pressure, which are found by means of dynamical systems and multiscale expansion techniques. These solutions include Boussinesq-like and Korteweg-de Vries pulse-shaped solitons that are observed in the experiment, as well as nonlinear Schrödinger envelope solitons, that are predicted theoretically. The analytical predictions are in excellent agreement with direct numerical simulations and in qualitative agreement with the experimental observations.

  19. Towards high-capacity fibre-optic communications at the speed of light in vacuum

    NASA Astrophysics Data System (ADS)

    Poletti, F.; Wheeler, N. V.; Petrovich, M. N.; Baddela, N.; Numkam Fokoua, E.; Hayes, J. R.; Gray, D. R.; Li, Z.; Slavík, R.; Richardson, D. J.

    2013-04-01

    Wide-bandwidth signal transmission with low latency is emerging as a key requirement in a number of applications, including the development of future exaflop-scale supercomputers, financial algorithmic trading and cloud computing. Optical fibres provide unsurpassed transmission bandwidth, but light propagates 31% slower in a silica glass fibre than in vacuum, thus compromising latency. Air guidance in hollow-core fibres can reduce fibre latency very significantly. However, state-of-the-art technology cannot achieve the combined values of loss, bandwidth and mode-coupling characteristics required for high-capacity data transmission. Here, we report a fundamentally improved hollow-core photonic-bandgap fibre that provides a record combination of low loss (3.5 dB km-1) and wide bandwidth (160 nm), and use it to transmit 37 × 40 Gbit s-1 channels at a 1.54 µs km-1 faster speed than in a conventional fibre. This represents the first experimental demonstration of fibre-based wavelength division multiplexed data transmission at close to (99.7%) the speed of light in vacuum.

  20. Study on Heat Transfer Agent Models of Transmission Line and Transformer

    NASA Astrophysics Data System (ADS)

    Wang, B.; Zhang, P. P.

    2018-04-01

    When using heat transfer simulation to study the dynamic overload of transmission line and transformer, it needs to establish the mathematical expression of heat transfer. However, the formula is a nonlinear differential equation or equation set and it is not easy to get general solutions. Aiming at this problem, some different temperature change processes caused by different initial conditions are calculated by differential equation and equation set. New agent models are developed according to the characteristics of different temperature change processes. The results show that the agent models have high precision and can solve the problem that the original equation cannot be directly applied in some practical engineers.

  1. Vacuum force

    NASA Astrophysics Data System (ADS)

    Han, Yongquan

    2015-03-01

    To study on vacuum force, we must clear what is vacuum, vacuum is a space do not have any air and also ray. There is not exist an absolute the vacuum of space. The vacuum of space is relative, so that the vacuum force is relative. There is a certain that vacuum vacuum space exists. In fact, the vacuum space is relative, if the two spaces compared to the existence of relative vacuum, there must exist a vacuum force, and the direction of the vacuum force point to the vacuum region. Any object rotates and radiates. Rotate bend radiate- centripetal, gravity produced, relative gravity; non gravity is the vacuum force. Gravity is centripetal, is a trend that the objects who attracted wants to Centripetal, or have been do Centripetal movement. Any object moves, so gravity makes the object curve movement, that is to say, the radiation range curve movement must be in the gravitational objects, gravity must be existed in non vacuum region, and make the object who is in the region of do curve movement (for example: The earth moves around the sun), or final attracted in the form gravitational objects, and keep relatively static with attract object. (for example: objects on the earth moves but can't reach the first cosmic speed).

  2. PIC simulation of the vacuum power flow for a 5 terawatt, 5 MV, 1 MA pulsed power system

    NASA Astrophysics Data System (ADS)

    Liu, Laqun; Zou, Wenkang; Liu, Dagang; Guo, Fan; Wang, Huihui; Chen, Lin

    2018-03-01

    In this paper, a 5 Terawatt, 5 MV, 1 MA pulsed power system based on vacuum magnetic insulation is simulated by the particle-in-cell (PIC) simulation method. The system consists of 50 100-kV linear transformer drive (LTD) cavities in series, using magnetically insulated induction voltage adder (MIVA) technology for pulsed power addition and transmission. The pulsed power formation and the vacuum power flow are simulated when the system works in self-limited flow and load-limited flow. When the pulsed power system isn't connected to the load, the downstream magnetically insulated transmission line (MITL) works in the self-limited flow, the maximum of output current is 1.14 MA and the amplitude of voltage is 4.63 MV. The ratio of the electron current to the total current is 67.5%, when the output current reached the peak value. When the impedance of the load is 3.0 Ω, the downstream MITL works in the self-limited flow, the maximums of output current and the amplitude of voltage are 1.28 MA and 3.96 MV, and the ratio of the electron current to the total current is 11.7% when the output current reached the peak value. In addition, when the switches are triggered in synchronism with the passage of the pulse power flow, it effectively reduces the rise time of the pulse current.

  3. Multi-band Microwave Antennas and Devices based on Generalized Negative-Refractive-Index Transmission Lines

    NASA Astrophysics Data System (ADS)

    Ryan, Colan Graeme Matthew

    Focused on the quad-band generalized negative-refractive-index transmission line (G-NRI-TL), this thesis presents a variety of novel printed G-NRI-TL multi-band microwave device and antenna prototypes. A dual-band coupled-line coupler, an all-pass G-NRI-TL bridged-T circuit, a dual-band metamaterial leaky-wave antenna, and a multi-band G-NRI-TL resonant antenna are all new developments resulting from this research. In addition, to continue the theme of multi-band components, negative-refractive-index transmission lines are used to create a dual-band circularly polarized transparent patch antenna and a two-element wideband decoupled meander antenna system. High coupling over two independently-specified frequency bands is the hallmark of the G-NRI-TL coupler: it is 0.35lambda0 long but achieves approximately -3 dB coupling over both bands with a maximum insertion loss of 1 dB. This represents greater design flexibility than conventional coupled-line couplers and less loss than subsequent G-NRI-TL couplers. The single-ended bridged-T G-NRI-TL offers a metamaterial unit cell with an all-pass magnitude response up to 8 GHz, while still preserving the quad-band phase response of the original circuit. It is shown how the all-pass response leads to wider bandwidths and improved matching in quad-band inverters, power dividers, and hybrid couplers. The dual-band metamaterial leaky-wave antenna presented here was the first to be reported in the literature, and it allows broadside radiation at both 2 GHz and 6 GHz without experiencing the broadside stopband common to conventional periodic antennas. Likewise, the G-NRI-TL resonant antenna is the first reported instance of such a device, achieving quad-band operation between 2.5 GHz and 5.6 GHz, with a minimum radiation efficiency of 80%. Negative-refractive-index transmission line loading is applied to two devices: an NRI-TL meander antenna achieves a measured 52% impedance bandwidth, while a square patch antenna incorporates

  4. On the radiated EMI current extraction of dc transmission line based on corona current statistical measurements

    NASA Astrophysics Data System (ADS)

    Yi, Yong; Chen, Zhengying; Wang, Liming

    2018-05-01

    Corona-originated discharge of DC transmission lines is the main reason for the radiated electromagnetic interference (EMI) field in the vicinity of transmission lines. A joint time-frequency analysis technique was proposed to extract the radiated EMI current (excitation current) of DC corona based on corona current statistical measurements. A reduced-scale experimental platform was setup to measure the statistical distributions of current waveform parameters of aluminum conductor steel reinforced. Based on the measured results, the peak value, root-mean-square value and average value with 9 kHz and 200 Hz band-with of 0.5 MHz radiated EMI current were calculated by the technique proposed and validated with conventional excitation function method. Radio interference (RI) was calculated based on the radiated EMI current and a wire-to-plate platform was built for the validity of the RI computation results. The reason for the certain deviation between the computations and measurements was detailed analyzed.

  5. Decision support for mitigating the risk of tree induced transmission line failure in utility rights-of-way.

    PubMed

    Poulos, H M; Camp, A E

    2010-02-01

    Vegetation management is a critical component of rights-of-way (ROW) maintenance for preventing electrical outages and safety hazards resulting from tree contact with conductors during storms. Northeast Utility's (NU) transmission lines are a critical element of the nation's power grid; NU is therefore under scrutiny from federal agencies charged with protecting the electrical transmission infrastructure of the United States. We developed a decision support system to focus right-of-way maintenance and minimize the potential for a tree fall episode that disables transmission capacity across the state of Connecticut. We used field data on tree characteristics to develop a system for identifying hazard trees (HTs) in the field using limited equipment to manage Connecticut power line ROW. Results from this study indicated that the tree height-to-diameter ratio, total tree height, and live crown ratio were the key characteristics that differentiated potential risk trees (danger trees) from trees with a high probability of tree fall (HTs). Products from this research can be transferred to adaptive right-of-way management, and the methods we used have great potential for future application to other regions of the United States and elsewhere where tree failure can disrupt electrical power.

  6. Atomic Oscillator Strengths in the Vacuum Ultraviolet

    NASA Technical Reports Server (NTRS)

    Nave, Gillian; Sansonetti, Craig J.; Szabo, Csilla I.

    2006-01-01

    We have developed techniques to measure branching fractions in the vacuum ultraviolet using diffraction grating spectroscopy and phosphor image plates as detectors. These techniques have been used to measure branching fractions in Fe II that give prominent emission lines in astrophysical objects.

  7. Effects of Primary Power Transmission Lines on the Performance of Loran-C Receivers in Experimental Terrestrial Applications

    DOT National Transportation Integrated Search

    1979-07-01

    Tests were conducted to measure the effect generated by high-voltage transmission lines with and without supervisory carrier signals on the performance of typical LORAN-C receivers which might be used for land vehicle applications of the LORAN-C Navi...

  8. Linear Stability of Relativistic Space-Charge Flow in a Magnetically Insulated Transmission Line Oscillator

    DTIC Science & Technology

    1989-04-01

    MILO Magnetica fy insulated transmission line Slow-wave structure Relativistic Brillouin flow Space-charge waves Slow electromagnetic waves (over) 19... resonant layer always see a decelerating axial electric field. Consequently, field energy increases at the expense of particle energy. 17 AFWL-TR-88-103...Ve). If ve is greater than the structure coupling velocity, a resonant layer of electrons will always be present, and oscillations will occur at any

  9. Study and Experiment on Non-Contact Voltage Sensor Suitable for Three-Phase Transmission Line

    PubMed Central

    Zhou, Qiang; He, Wei; Xiao, Dongping; Li, Songnong; Zhou, Kongjun

    2015-01-01

    A voltage transformer, as voltage signal detection equipment, plays an important role in a power system. Presently, more and more electric power systems are adopting potential transformer and capacitance voltage transformers. Transformers are often large in volume and heavyweight, their insulation design is difficult, and an iron core or multi-grade capacitance voltage division structure is generally adopted. As a result, the detection accuracy of transformer is reduced, a huge phase difference exists between detection signal and voltage signal to be measured, and the detection signal cannot accurately and timely reflect the change of conductor voltage signal to be measured. By aiming at the current problems of electric transformation, based on electrostatic induction principle, this paper designed a non-contact voltage sensor and gained detection signal of the sensor through electrostatic coupling for the electric field generated by electric charges of the conductor to be measured. The insulation structure design of the sensor is simple and its volume is small; phase difference of sensor measurement is effectively reduced through optimization design of the electrode; and voltage division ratio and measurement accuracy are increased. The voltage sensor was tested on the experimental platform of simulating three-phase transmission line. According to the result, the designed non-contact voltage sensor can realize accurate and real-time measurement for the conductor voltage. It can be applied to online monitoring for the voltage of three-phase transmission line or three-phase distribution network line, which is in accordance with the development direction of the smart grid. PMID:26729119

  10. Study and Experiment on Non-Contact Voltage Sensor Suitable for Three-Phase Transmission Line.

    PubMed

    Zhou, Qiang; He, Wei; Xiao, Dongping; Li, Songnong; Zhou, Kongjun

    2015-12-30

    A voltage transformer, as voltage signal detection equipment, plays an important role in a power system. Presently, more and more electric power systems are adopting potential transformer and capacitance voltage transformers. Transformers are often large in volume and heavyweight, their insulation design is difficult, and an iron core or multi-grade capacitance voltage division structure is generally adopted. As a result, the detection accuracy of transformer is reduced, a huge phase difference exists between detection signal and voltage signal to be measured, and the detection signal cannot accurately and timely reflect the change of conductor voltage signal to be measured. By aiming at the current problems of electric transformation, based on electrostatic induction principle, this paper designed a non-contact voltage sensor and gained detection signal of the sensor through electrostatic coupling for the electric field generated by electric charges of the conductor to be measured. The insulation structure design of the sensor is simple and its volume is small; phase difference of sensor measurement is effectively reduced through optimization design of the electrode; and voltage division ratio and measurement accuracy are increased. The voltage sensor was tested on the experimental platform of simulating three-phase transmission line. According to the result, the designed non-contact voltage sensor can realize accurate and real-time measurement for the conductor voltage. It can be applied to online monitoring for the voltage of three-phase transmission line or three-phase distribution network line, which is in accordance with the development direction of the smart grid.

  11. An integrated wire harp and readout electronics inside vacuum.

    PubMed

    Chatterjee, Mou; Nabhiraj, P Y

    2015-03-01

    A wire harp is a well known instrument used in ion beam profile measurement and beam diagnostics. Till date, for beam instrumentation, the harp is placed inside the vacuum chamber or beam line in direct exposure to the beam profile to be measured, whereas the related readout electronics is placed outside somewhere at a convenient place. Here, a harp has been developed along with the readout electronics as an integrated part of it and both were placed inside the beam line vacuum (order of 10(-7) Torr) to make the system much simpler, easy to operate, and measure small beam current more accurately. The entire signal conversion and processing is done inside the vacuum unlike other systems; hence, the electronics is kept inside. This results in a lesser number (only 4 pin) of electrical connections (feedthrough) including power which otherwise would have required 32 feedthrough pins only for signal readout for a 13 × 13 (X × Y) channel harp. This paper describes a completely new approach to the design of a conventional beam harp widely used for beam instrumentation.

  12. An integrated wire harp and readout electronics inside vacuum

    NASA Astrophysics Data System (ADS)

    Chatterjee, Mou; Nabhiraj, P. Y.

    2015-03-01

    A wire harp is a well known instrument used in ion beam profile measurement and beam diagnostics. Till date, for beam instrumentation, the harp is placed inside the vacuum chamber or beam line in direct exposure to the beam profile to be measured, whereas the related readout electronics is placed outside somewhere at a convenient place. Here, a harp has been developed along with the readout electronics as an integrated part of it and both were placed inside the beam line vacuum (order of 10-7 Torr) to make the system much simpler, easy to operate, and measure small beam current more accurately. The entire signal conversion and processing is done inside the vacuum unlike other systems; hence, the electronics is kept inside. This results in a lesser number (only 4 pin) of electrical connections (feedthrough) including power which otherwise would have required 32 feedthrough pins only for signal readout for a 13 × 13 (X × Y) channel harp. This paper describes a completely new approach to the design of a conventional beam harp widely used for beam instrumentation.

  13. Structural health monitoring of compression connectors for overhead transmission lines

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

    Wang, Hong; Wang, Jy-An John; Swindeman, Joseph P

    Two-stage aluminum conductor steel-reinforced (ACSR) compression connectors are extensively used in US overhead transmission lines. The connectors are made by crimping a steel sleeve onto a steel core and an aluminum sleeve over aluminum conductive strands. The connectors are designed to operate at temperatures up to 125 C, but their performance is increasingly degrading because of overloading of lines. Currently, electric utilities conduct routine line inspections using thermal and electrical measurements. However, information about the structural integrity of connectors cannot be obtained. In this work, structural health monitoring (SHM) of compression connectors was studied using electromechanical impedance (EMI) analysis. Leadmore » zirconate titanate (PZT)-5A was identified as a smart material for SHM. A flexible high-temperature bonding layer was used to address challenges in PZT integration due to a significant difference in the coefficients of thermal expansion of PZT and the aluminum substrate. The steel joint on the steel core was investigated because it is responsible for the ultimate tensile strength of the connector. Tensile testing was used to create structural damage to the joint, or steel core pullout, and thermal cycling introduced additional structural perturbations. EMI measurements were conducted between the tests. The root mean square deviation (RMSD) of EMI was identified as a damage index. The use of steel joints has been shown to enable SHM under simulated conditions. The EMI signature is sensitive to variations in structural conditions. RMSD can be correlated to the structural health of a connector and has potential for use in the SHM and structural integrity evaluation.« less

  14. Structural health monitoring of compression connectors for overhead transmission lines

    NASA Astrophysics Data System (ADS)

    Wang, Hong; Wang, Jy-An John; Swindeman, Joseph P.; Ren, Fei; Chan, John

    2017-04-01

    Two-stage aluminum conductor steel-reinforced (ACSR) compression connectors are extensively used in US overhead transmission lines. The connectors are made by crimping a steel sleeve onto a steel core and an aluminum sleeve over electrical conducting aluminum strands. The connectors are designed to operate at temperatures up to 125°C, but their performance is increasingly degrading because of overloading of lines. Currently, electric utilities conduct routine line inspections using thermal and electrical measurements, but these methods do not provide information about the structural integrity of connectors. In this work, structural health monitoring (SHM) of compression connectors was studied using electromechanical impedance (EMI) analysis. Lead zirconate titanate (PZT)-5A was identified as a smart material for SHM. A flexible high-temperature bonding layer was used to address challenges in PZT integration due to a significant difference in the coefficients of thermal expansion of PZT and the aluminum substrate. The steel joint on the steel core was investigated because it is responsible for the ultimate tensile strength of the connector. Tensile testing was used to induce structural damage to the joint, or steel core pullout, and thermal cycling introduced additional structural perturbations. EMI measurements were conducted between the tests. The root mean square deviation (RMSD) of EMI was identified as a damage index. The use of steel joints has been shown to enable SHM under simulated conditions. The EMI signature is sensitive to variations in structural conditions. RMSD can be correlated to the structural health of a connector and has potential for use in the SHM and structural integrity evaluation.

  15. Secure and Time-Aware Communication of Wireless Sensors Monitoring Overhead Transmission Lines

    PubMed Central

    Mazur, Katarzyna; Wydra, Michal; Ksiezopolski, Bogdan

    2017-01-01

    Existing transmission power grids suffer from high maintenance costs and scalability issues along with a lack of effective and secure system monitoring. To address these problems, we propose to use Wireless Sensor Networks (WSNs)as a technology to achieve energy efficient, reliable, and low-cost remote monitoring of transmission grids. With WSNs, smart grid enables both utilities and customers to monitor, predict and manage energy usage effectively and react to possible power grid disturbances in a timely manner. However, the increased application of WSNs also introduces new security challenges, especially related to privacy, connectivity, and security management, repeatedly causing unpredicted expenditures. Monitoring the status of the power system, a large amount of sensors generates massive amount of sensitive data. In order to build an effective Wireless Sensor Networks (WSNs) for a smart grid, we focus on designing a methodology of efficient and secure delivery of the data measured on transmission lines. We perform a set of simulations, in which we examine different routing algorithms, security mechanisms and WSN deployments in order to select the parameters that will not affect the delivery time but fulfill their role and ensure security at the same time. Furthermore, we analyze the optimal placement of direct wireless links, aiming at minimizing time delays, balancing network performance and decreasing deployment costs. PMID:28696390

  16. The trophic vacuum and the evolution of complex life cycles in trophically transmitted helminths.

    PubMed

    Benesh, Daniel P; Chubb, James C; Parker, Geoff A

    2014-10-22

    Parasitic worms (helminths) frequently have complex life cycles in which they are transmitted trophically between two or more successive hosts. Sexual reproduction often takes place in high trophic-level (TL) vertebrates, where parasites can grow to large sizes with high fecundity. Direct infection of high TL hosts, while advantageous, may be unachievable for parasites constrained to transmit trophically, because helminth propagules are unlikely to be ingested by large predators. Lack of niche overlap between propagule and definitive host (the trophic transmission vacuum) may explain the origin and/or maintenance of intermediate hosts, which overcome this transmission barrier. We show that nematodes infecting high TL definitive hosts tend to have more successive hosts in their life cycles. This relationship was modest, though, driven mainly by the minimum TL of hosts, suggesting that the shortest trophic chains leading to a host define the boundaries of the transmission vacuum. We also show that alternative modes of transmission, like host penetration, allow nematodes to reach high TLs without intermediate hosts. We suggest that widespread omnivory as well as parasite adaptations to increase transmission probably reduce, but do not eliminate, the barriers to the transmission of helminths through the food web. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  17. Development of a Laboratory Synchrophasor Network and an Application to Estimate Transmission Line Parameters in Real Time

    NASA Astrophysics Data System (ADS)

    Almiron Bonnin, Rubens Eduardo

    The development of an experimental synchrophasors network and application of synchrophasors for real-time transmission line parameter monitoring are presented in this thesis. In the laboratory setup, a power system is simulated in a RTDS real-time digital simulator, and the simulated voltages and currents are input to hardware phasor measurement units (PMUs) through the analog outputs of the simulator. Time synchronizing signals for the PMU devices are supplied from a common GPS clock. The real time data collected from PMUs are sent to a phasor data concentrator (PDC) through Ethernet using the TCP/IP protocol. A real-time transmission line parameter monitoring application program that uses the synchrophasor data provided by the PDC is implemented and validated. The experimental synchrophasor network developed in this thesis is expected to be used in research on synchrophasor applications as well as in graduate and undergraduate teaching.

  18. Tribologic analyses of a self-mated aluminium contact used for overhead transmission lines

    NASA Astrophysics Data System (ADS)

    Steier, V. Franco

    2017-05-01

    The lifetime of aluminium components is often limited to their poor wear resistance. One example for such aluminium applications are overhead transmission lines. The sore points of these lines are the segments where the aluminium conductors are fixed to the line supports. The fixation is commonly realized via aluminium suspension clamps. Here, a superposition of different loads like traction and bending stresses, clamping forces and different types of wear occurs. To investigate the wear behaviour in these peculiar points, tribologic model tests were carried out. Within the tests, overhead conductor wires and aluminium plates, extracted from suspension clamps were reciprocally slid against aluminium plates (cylinder-on-plate test). The COF and a wear related parameter were recorded constantly. Subsequently, the loaded surfaces were analysed using confocal laser and electron scanning microscopy as well as energy dispersive X-ray spectroscopy. The investigation detected the formation of an oxidized tribologic layer between both components. The tribolayer, which mayor part adhered on the suspension clamps, was mostly formed from material removed from the conductor wires.

  19. El Paso Electric Company Diablo Substation to the US-Mexico border 115kV transmission line project. Final Environmental Assessment

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

    Not Available

    1992-04-01

    This Environmental Assessment documents the analysis of alternative corridors for development and operation of a proposed 115 kilovolt transmission line using private lands and transporting power to the US-Mexico international border. The project will require (1) an amendment to El Paso Electric Company`s existing export authorization to transfer power across this border, and (2) a Presidential Permit for construction of the transmission line. The project would be located in Dona Ana county in southern New Mexico, approximately five miles west of El Paso, Texas. The alternative corridors, specific locations within those corridors, and structure types are identified and analyzed inmore » the environmental studies.« less

  20. On the dynamic response of pressure transmission lines in the research of helium-charged free piston Stirling engines

    NASA Technical Reports Server (NTRS)

    Miller, Eric L.; Dudenhoefer, James E.

    1989-01-01

    The signal distortion inherent to pressure transmission lines in free-piston Stirling engine research is discussed. Based on results from classical analysis, guidelines are formulated to describe the dynamic response properties of a volume-terminated transmission tube for applications involving the helium-charged free-piston Stirling engines. The underdamped flow regime is described, the primary resonance frequency is derived, and the pressure phase and amplitude distortion are discussed. The scope and limitation of the dynamic response analysis are considered.

  1. Semi-flexible gas-insulated transmission line using electric field stress shields

    DOEpatents

    Cookson, A.H.; Dale, S.J.; Bolin, P.C.

    1982-12-28

    A gas-insulated transmission line includes an outer sheath, an inner conductor, an insulating gas electrically insulating the inner conductor from the outer sheath, and insulating supports insulatably supporting the inner conductor within the outer sheath. The inner conductor is provided with flexibility by use of main conductor sections which are joined together through a conductor hub section and flexible flexing elements. Stress shields are provided to control the electric field at the locations of the conductor hub sections where the insulating supports are contacting the inner conductor. The flexing elements and the stress shields may also be utilized in connection with a plug and socket arrangement for providing electrical connection between main conductor sections. 10 figs.

  2. Semi-flexible gas-insulated transmission line using electric field stress shields

    DOEpatents

    Cookson, Alan H.; Dale, Steinar J.; Bolin, Philip C.

    1982-12-28

    A gas-insulated transmission line includes an outer sheath, an inner conductor, an insulating gas electrically insulating the inner conductor from the outer sheath, and insulating supports insulatably supporting the inner conductor within the outer sheath. The inner conductor is provided with flexibility by use of main conductor sections which are joined together through a conductor hub section and flexible flexing elements. Stress shields are provided to control the electric field at the locations of the conductor hub sections where the insulating supports are contacting the inner conductor. The flexing elements and the stress shields may also be utilized in connection with a plug and socket arrangement for providing electrical connection between main conductor sections.

  3. Ideal plasma response to vacuum magnetic fields with resonant magnetic perturbations in non-axisymmetric tokamaks

    DOE PAGES

    Kim, Kimin; Ahn, J. -W.; Scotti, F.; ...

    2015-09-03

    Ideal plasma shielding and amplification of resonant magnetic perturbations in non-axisymmetric tokamak is presented by field line tracing simulation with full ideal plasma response, compared to measurements of divertor lobe structures. Magnetic field line tracing simulations in NSTX with toroidal non-axisymmetry indicate the ideal plasma response can significantly shield/amplify and phase shift the vacuum resonant magnetic perturbations. Ideal plasma shielding for n = 3 mode is found to prevent magnetic islands from opening as consistently shown in the field line connection length profile and magnetic footprints on the divertor target. It is also found that the ideal plasma shielding modifiesmore » the degree of stochasticity but does not change the overall helical lobe structures of the vacuum field for n = 3. Furthermore, amplification of vacuum fields by the ideal plasma response is predicted for low toroidal mode n = 1, better reproducing measurements of strong striation of the field lines on the divertor plate in NSTX.« less

  4. A User''s Guide to the Zwikker-Kosten Transmission Line Code (ZKTL)

    NASA Technical Reports Server (NTRS)

    Kelly, J. J.; Abu-Khajeel, H.

    1997-01-01

    This user's guide documents updates to the Zwikker-Kosten Transmission Line Code (ZKTL). This code was developed for analyzing new liner concepts developed to provide increased sound absorption. Contiguous arrays of multi-degree-of-freedom (MDOF) liner elements serve as the model for these liner configurations, and Zwikker and Kosten's theory of sound propagation in channels is used to predict the surface impedance. Transmission matrices for the various liner elements incorporate both analytical and semi-empirical methods. This allows standard matrix techniques to be employed in the code to systematically calculate the composite impedance due to the individual liner elements. The ZKTL code consists of four independent subroutines: 1. Single channel impedance calculation - linear version (SCIC) 2. Single channel impedance calculation - nonlinear version (SCICNL) 3. Multi-channel, multi-segment, multi-layer impedance calculation - linear version (MCMSML) 4. Multi-channel, multi-segment, multi-layer impedance calculation - nonlinear version (MCMSMLNL) Detailed examples, comments, and explanations for each liner impedance computation module are included. Also contained in the guide are depictions of the interactive execution, input files and output files.

  5. Research on the correlation between corona current spectrum and audible noise spectrum of HVDC transmission line

    NASA Astrophysics Data System (ADS)

    Liu, Yingyi; Zhou, Lijuan; Liu, Yuanqing; Yuan, Haiwen; Ji, Liang

    2017-11-01

    Audible noise is closely related to corona current on a high voltage direct current (HVDC) transmission line. In this paper, we measured a large amount of audible noise and corona current waveforms simultaneously based on the largest outdoor HVDC corona cage all over the world. By analyzing the experimental data, the related statistical regularities between a corona current spectrum and an audible noise spectrum were obtained. Furthermore, the generation mechanism of audible noise was analyzed theoretically, and the related mathematical expression between the audible noise spectrum and the corona current spectrum, which is suitable for all of these measuring points in the space, has been established based on the electro-acoustic conversion theory. Finally, combined with the obtained mathematical relation, the internal reasons for these statistical regularities appearing in measured corona current and audible noise data were explained. The results of this paper not only present the statistical association regularities between the corona current spectrum and the audible noise spectrum on a HVDC transmission line, but also reveal the inherent reasons of these associated rules.

  6. Coupling of an applied field magnetically insulated ion diode to a high power magnetically insulated transmission line system

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

    Maenchen, J.E.

    1983-01-01

    The coupling of energy from a high power pulsed accelerator through a long triplate magnetically insulated transmission line (MITL) in vacuum to an annular applied magnetic field insulated extraction ion diode is examined. The narrow power transport window and the wave front erosion of the MITL set stringent impedance history conditions on the diode load. A new ion diode design developed to satisfy these criteria with marginal electron insulation is presented. The LION accelerator is used to provide a positive polarity 1.5 MV, 350 kA, 40 ns FWHM pulse with a 30 kA/ns current rate from a triplate MITL source.more » A transition converts the triplate into a cylindrical cross section which flares into the ion diode load. Extensive current and voltage measurements performed along this structure and on the extracted ion beam provide conclusive evidence that the self insulation condition of the MITL is maintained in the transition by current loss alone. The ion diode utilizes a radial magnetic field between a grounded cathode annular emission tip and a disk anode. A 50 cm/sup 2/ dielectric/metal anode area serves as the ion plasma source subject to direct electron bombardment from the opposing cathode tip under marginal magnetic insulation conditions. The ions extracted cross the radial magnetic field and exit the diode volume as an annular cross section beam of peak current about 100 kA. The diode current gradually converts from the initial electron flow to nearly 100% ion current af« less

  7. [Accuracy of attenuation coefficient obtained by 137Cs single-transmission scanning in PET: comparison with conventional germanium line source].

    PubMed

    Matsumoto, Keiichi; Kitamura, Keishi; Mizuta, Tetsuro; Shimizu, Keiji; Murase, Kenya; Senda, Michio

    2006-02-20

    Transmission scanning can be successfully performed with a Cs-137 single-photon-emitting point source for three-dimensional PET imaging. This method was effective for postinjection transmission scanning because of differences in physical energy. However, scatter contamination in the transmission data lowers measured attenuation coefficients. The purpose of this study was to investigate the accuracy of the influence of object scattering by measuring the attenuation coefficients on the transmission images. We also compared the results with the conventional germanium line source method. Two different types of PET scanner, the SET-3000 G/X (Shimadzu Corp.) and ECAT EXACT HR(+) (Siemens/CTI) , were used. For the transmission scanning, the SET-3000 G/X and ECAT HR(+) were the Cs-137 point source and Ge-68/Ga-68 line source, respectively. With the SET-3000 G/X, we performed transmission measurement at two energy gate settings, the standard 600-800 keV as well as 500-800 keV. The energy gate setting of the ECAT HR(+) was 350-650 keV. The effects of scattering in a uniform phantom with different cross-sectional areas ranging from 201 cm(2) to 314 cm(2) to 628 cm(2) (apposition of the two 20 cm diameter phantoms) and 943 cm(2) (stacking of the three 20 cm diameter phantoms) were acquired without emission activity. First, we evaluated the attenuation coefficients of the two different types of transmission scanning using region of interest (ROI) analysis. In addition, we evaluated the attenuation coefficients with and without segmentation for Cs-137 transmission images using the same analysis. The segmentation method was a histogram-based soft-tissue segmentation process that can also be applied to reconstructed transmission images. In the Cs-137 experiment, the maximum underestimation was 3% without segmentation, which was reduced to less than 1% with segmentation at the center of the largest phantom. In the Ge-68/Ga-68 experiment, the difference in mean attenuation

  8. Chirped pulse inverse free-electron laser vacuum accelerator

    DOEpatents

    Hartemann, Frederic V.; Baldis, Hector A.; Landahl, Eric C.

    2002-01-01

    A chirped pulse inverse free-electron laser (IFEL) vacuum accelerator for high gradient laser acceleration in vacuum. By the use of an ultrashort (femtosecond), ultrahigh intensity chirped laser pulse both the IFEL interaction bandwidth and accelerating gradient are increased, thus yielding large gains in a compact system. In addition, the IFEL resonance condition can be maintained throughout the interaction region by using a chirped drive laser wave. In addition, diffraction can be alleviated by taking advantage of the laser optical bandwidth with negative dispersion focusing optics to produce a chromatic line focus. The combination of these features results in a compact, efficient vacuum laser accelerator which finds many applications including high energy physics, compact table-top laser accelerator for medical imaging and therapy, material science, and basic physics.

  9. Vacuum-integrated electrospray deposition for highly reliable polymer thin film.

    PubMed

    Park, Soohyung; Lee, Younjoo; Yi, Yeonjin

    2012-10-01

    Vacuum electrospray deposition (ESD) equipment was designed to prepare polymer thin films. The polymer solution can be injected directly into vacuum system through multi-stage pumping line, so that the solvent residues and ambient contaminants are highly reduced. To test the performance of ESD system, we fabricated organic photovoltaic cells (OPVCs) by injecting polymer solution directly onto the substrate inside a high vacuum chamber. The OPVC fabricated has the structure of Al∕P3HT:PCBM∕PEDOT:PSS∕ITO and was optimized by varying the speed of solution injection and concentration of the solution. The power conversion efficiency (PCE) of the optimized OPVC is 3.14% under AM 1.5G irradiation without any buffer layer at the cathode side. To test the advantages of the vacuum ESD, we exposed the device to atmosphere between the deposition steps of the active layer and cathode. This showed that the PCE of the vacuum processed device is 24% higher than that of the air exposed device and confirms the advantages of the vacuum prepared polymer film for high performance devices.

  10. Instrument for measurement of vacuum in sealed thin wall packets

    DOEpatents

    Kollie, T.G.; Thacker, L.H.; Fine, H.A.

    1993-10-05

    An instrument is described for the measurement of vacuum within sealed packets, the packets having a wall sufficiently thin that it can be deformed by the application of an external vacuum to small area thereof. The instrument has a detector head for placement against the deformable wall of the packet to apply the vacuum in a controlled manner to accomplish a limited deformation or lift of the wall, with this deformation or lift monitored by the application of light as via a bifurcated light pipe. Retro-reflected light through the light pipe is monitored with a photo detector. An abrupt change (e.g., a decrease) of retro-reflected light signals the wall movement such that the value of the vacuum applied through the head to achieve this initiation of movement is equal to the vacuum within the packet. In a preferred embodiment a vacuum reference plate is placed beneath the packet to ensure that no deformation occurs on the reverse surface of the packet. A packet production line model is also described. 3 figures.

  11. Instrument for measurement of vacuum in sealed thin wall packets

    DOEpatents

    Kollie, Thomas G.; Thacker, Louis H.; Fine, H. Alan

    1993-01-01

    An instrument for the measurement of vacuum within sealed packets 12, the packets 12 having a wall 14 sufficiently thin that it can be deformed by the application of an external vacuum to small area thereof. The instrument has a detector head 18 for placement against the deformable wall 14 of the packet to apply the vacuum in a controlled manner to accomplish a limited deformation or lift of the wall 14, with this deformation or lift monitored by the application of light as via a bifurcated light pipe 20. Retro-reflected light through the light pipe is monitored with a photo detector 26. An abrupt change (e.g., a decrease) of retro-reflected light signals the wall movement such that the value of the vacuum applied through the head 18 to achieve this initiation of movement is equal to the vacuum Within the packet 12. In a preferred embodiment a vacuum reference plate 44 is placed beneath the packet 12 to ensure that no deformation occurs on the reverse surface 16 of the packet. A packet production line model is also described.

  12. Seasonal Patterns of Melatonin, Cortisol, and Progesterone Secretion in Female Lambs Raised Beneath a 500-kV Transmission Line.

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

    Lee, Jack M.

    Although several kinds of biological effects of electric and magnetic fields have been reported from laboratory studies, few have been independently replicated. When this study was being planned, the suppression of nighttime melatonin in rodents was thought to represent one of the strongest known effects of these fields. The effect had been replicated by a single laboratory for 60-Hz electric fields, and by multiple laboratories for d-c magnetic fields. The primary objective of this study was to determine whether the effect of electric and magnetic fields on melatonin would also occur in sheep exposed to a high voltage transmission line.more » The specific hypothesis tested by this experiment was as follows: The electrical environment produced by a 60-Hz, 500-kV transmission line causes a depression in nocturnal melatonin in chronically exposed female lambs. This may mimic effects of pinealectomy or constant long-day photoperiods, thus delaying the onset of reproductive cycles. Results of the study do not provide evidence to support the hypothesis. Melatonin concentrations in the sheep exposed to the transmission line showed the normal pattern of low daytime and high nighttime serum levels. As compared to the control group, there were no statistically significant group differences in the mean amplitude, phase, or duration of the nighttime melatonin elevation.« less

  13. Effects of high-voltage transmission lines on honeybees

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

    Greenberg, B.; Bindokas, V.P.; Gauger, J.R.

    When shielded and exposed colonies were placed at incremental distances at a right angle from a 760-kV transmission line different thresholds for biologic effects were obtained. Hive exposures were controlled (E-field: 7, 5.5, 4.1, 1.8, and 0.65 to 0.85 kV/m) by variable height current collectors; shielded hives under the line behave normally. Exposure to 7 kV/m can produce the following sequence of events: (1) increased motor activity and transient hive temperature increase; (2) abnormal propolization; (3) retarded hive weight gain; (4) excess queen cell production with queen loss; (5) reduction of sealed brood area; and (6) poor winter survival. Nomore » biological effects were detected below 4.1 kV/m, thus the ''biological effects corridor'' is limited to approximately 23 m beyond a ground projection of each outer phase wire. Hive architecture enhances E-fields and creates shock hazards for bees. Intra-hive E-fields (15 to 100+ kV/m) were measured with a displacement current sensor and fiber optic telemetry link. Step-potential-induced currents up to 0.5 uA were measured with a bee model in hives at 7 kV/m. To investigate further the role of shock versus electric field exposure the study was continued to develop hive entrance extensions (porches), which produce controlled bee exposure to E-field or shock, and to test the feasibility of using these porches in such a study. Biological effects (e.g., abnormal propolization, retarded hive weight, queen loss) found in colonies with total-hive exposure were produced by entrance-only exposure of adult bees. We now have an exposure system in which E-field and shock can be separately controlled to reproduce the biological effects. 10 refs.« less

  14. Sound transmission through a double-panel construction lined with poroelastic material in the presence of mean flow

    NASA Astrophysics Data System (ADS)

    Zhou, Jie; Bhaskar, Atul; Zhang, Xin

    2013-08-01

    This paper investigates the sound transmission characteristics through a system of double-panel lined with poroelastic material in the core. The panels are surrounded by external and internal fluid media where a uniform external mean flow exists on one side. Biot's theory is used to model the porous material. Three types of constructions—bonded-bonded, bonded-unbonded and unbonded-unbonded—are considered. The effect of Mach number of the external flow on the sound transmission over a wide frequency range in a diffuse sound field is examined. External mean flow is shown to give a modest increase in transmission loss at low frequency, but a significant increase at high frequency. It is brought out that calculations based on static air on the incidence side provide a conservative estimate of sound transmission through the sandwich structure. The acoustic performance of the sandwich panel for different configurations is presented. The effect of curvature of the panel is also brought out by using shallow shell theory.

  15. Acquisition of second-line drug resistance and extensive drug resistance during recent transmission of Mycobacterium tuberculosis in rural China.

    PubMed

    Hu, Y; Mathema, B; Zhao, Q; Chen, L; Lu, W; Wang, W; Kreiswirth, B; Xu, B

    2015-12-01

    Multidrug-resistant tuberculosis (MDR-TB) is prevalent in countries with a high TB burden, like China. As little is known about the emergence and spread of second-line drug (SLD) -resistant TB, we investigate the emergence and transmission of SLD-resistant Mycobacterium tuberculosis in rural China. In a multi-centre population-based study, we described the bacterial population structure and the transmission characteristics of SLD-resistant TB using Spoligotyping in combination with genotyping based on 24-locus MIRU-VNTR (mycobacterial interspersed repetitive unit-variable-number tandem repeat) plus four highly variable loci for the Beijing family, in four rural Chinese regions with diverse geographic and socio-demographic characteristics. Transmission networks among genotypically clustered patients were constructed using social network analysis. Of 1332 M. tuberculosis patient isolates recovered, the Beijing family represented 74.8% of all isolates and an association with MDR and simultaneous resistance between first-line drugs and SLDs. The genotyping analysis revealed that 189 isolates shared MIRU-VNTR patterns in 78 clusters with clustering rate and recent transmission rate of 14.2% and 8.3%, respectively. Fifty-three SLD-resistant isolates were observed in 31 clusters, 30 of which contained the strains with different drug susceptibility profiles and genetic mutations. In conjunction with molecular data, socio-network analysis indicated a key role of Central Township in the transmission across a highly interconnected network where SLD resistance accumulation occurred during transmission. SLD-resistant M. tuberculosis has been spreading in rural China with Beijing family being the dominant strains. Primary transmission of SLD-resistant strains in the population highlights the importance of routine drug susceptibility testing and effective anti-tuberculosis regimens for drug-resistant TB. Copyright © 2015 European Society of Clinical Microbiology and

  16. Finite element probabilistic risk assessment of transmission line insulation flashovers caused by lightning strokes

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

    Bacvarov, D.C.

    1981-01-01

    A new method for probabilistic risk assessment of transmission line insulation flashovers caused by lightning strokes is presented. The utilized approach of applying the finite element method for probabilistic risk assessment is demonstrated to be very powerful. The reasons for this are two. First, the finite element method is inherently suitable for analysis of three dimensional spaces where the parameters, such as three variate probability densities of the lightning currents, are non-uniformly distributed. Second, the finite element method permits non-uniform discretization of the three dimensional probability spaces thus yielding high accuracy in critical regions, such as the area of themore » low probability events, while at the same time maintaining coarse discretization in the non-critical areas to keep the number of grid points and the size of the problem to a manageable low level. The finite element probabilistic risk assessment method presented here is based on a new multidimensional search algorithm. It utilizes an efficient iterative technique for finite element interpolation of the transmission line insulation flashover criteria computed with an electro-magnetic transients program. Compared to other available methods the new finite element probabilistic risk assessment method is significantly more accurate and approximately two orders of magnitude computationally more efficient. The method is especially suited for accurate assessment of rare, very low probability events.« less

  17. An integrated wire harp and readout electronics inside vacuum

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

    Chatterjee, Mou; Nabhiraj, P. Y.

    A wire harp is a well known instrument used in ion beam profile measurement and beam diagnostics. Till date, for beam instrumentation, the harp is placed inside the vacuum chamber or beam line in direct exposure to the beam profile to be measured, whereas the related readout electronics is placed outside somewhere at a convenient place. Here, a harp has been developed along with the readout electronics as an integrated part of it and both were placed inside the beam line vacuum (order of 10{sup −7} Torr) to make the system much simpler, easy to operate, and measure small beammore » current more accurately. The entire signal conversion and processing is done inside the vacuum unlike other systems; hence, the electronics is kept inside. This results in a lesser number (only 4 pin) of electrical connections (feedthrough) including power which otherwise would have required 32 feedthrough pins only for signal readout for a 13 × 13 (X × Y) channel harp. This paper describes a completely new approach to the design of a conventional beam harp widely used for beam instrumentation.« less

  18. Data transmission system with distributed microprocessors

    DOEpatents

    Nambu, Shigeo

    1985-01-01

    A data transmission system having a common request line and a special request line in addition to a transmission line. The special request line has priority over the common request line. A plurality of node stations are multi-drop connected to the transmission line. Among the node stations, a supervising station is connected to the special request line and takes precedence over other slave stations to become a master station. The master station collects data from the slave stations. The station connected to the common request line can assign a master control function to any station requesting to be assigned the master control function within a short period of time. Each station has an auto response control circuit. The master station automatically collects data by the auto response controlling circuit independently of the microprocessors of the slave stations.

  19. Vacuum-deposited polymer/silver reflector material

    NASA Astrophysics Data System (ADS)

    Affinito, John D.; Martin, Peter M.; Gross, Mark E.; Bennett, Wendy D.

    1994-09-01

    Weatherable, low cost, front surface, solar reflectors on flexible substrates would be highly desirable for lamination to solar concentrator panels. The method to be described in this paper may permit such reflector material to be fabricated for less the 50$CNT per square foot. Vacuum deposited Polymer/Silver/Polymer reflectors and Fabry-Perot interference filters were fabricated in a vacuum web coating operation on polyester substrates. Reflectivities were measured in the wavelength range from .4 micrometers to .8 micrometers . It is hoped that a low cost substrate can be used with the substrate laminated to the concentrator and the weatherable acrylic polymer coating facing the sun. This technique should be capable of deposition line speeds approaching 1500 linear feet/minute2. Central to this technique is a new vacuum deposition process for the high rate deposition of polymer films. This polymer process involves the flash evaporation of an acrylic monomer onto a moving substrate. The monomer is subsequently cured by an electron beam or ultraviolet light. This high speed polymer film deposition process has been named the PML process- for Polymer Multi- Layer.

  20. Experimental research on Ku-band magnetically insulated transmission line oscillator

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

    Jiang, Tao; Zhang, Jiande; He, Juntao

    2015-10-15

    An improved Ku-band magnetically insulated transmission line oscillator is proposed and investigated experimentally. In the particle-in-cell simulation, the Ku-band MILO generates the microwave with a power of 1.62 GW and a frequency of 13 GHz at the input voltage of 474 kV. The device is fabricated based on the simulation results, and an experiment system is designed. In the preliminary experiments, output microwave with frequency of 13.02 GHz, power of 150 MW, and pulse width of 17 ns is generated, under the diode voltage of 450 kV. Analysis on the experiment results shows that plasma produced due to the large current hitting to the outside of themore » collection tank is the essential cause for the low amplitude of the microwave power and short pulse width.« less

  1. Irradiation and measurements of fluorinated ethylene-propylene-A on silicon solar cells in vacuum

    NASA Technical Reports Server (NTRS)

    Marsik, S. J.; Broder, J. D.

    1975-01-01

    Silicon monoxide (SiO) coated silicon solar cells covered with fluorinated ethylene-propylene-A (FEP-A) were irradiated by 1-MeV electrons in vacuum. The effect of irradiation on the light transmittance of FEP-A was checked by measuring the short-circuit current of the cells while in vacuum after each dose increment, immediately after the irradiation, and again after a minimum elapsed time of 16 hr. The results indicated no apparent loss in transmission due to irradiation of FEP-A and no delamination from the SiO surface while the cells were in vacuum, but embrittlement of FEP-A occurred at the accumulated dose.

  2. Localization properties of transmission lines with generalized Thue-Morse distribution of inductances

    NASA Astrophysics Data System (ADS)

    Lazo, Edmundo; Saavedra, Eduardo; Humire, Fernando; Castro, Cristobal; Cortés-Cortés, Francisco

    2015-09-01

    We study the localization properties of direct transmission lines when we distribute two values of inductances LA and LB according to a generalized Thue-Morse aperiodic sequence generated by the inflation rule: A → ABm-1, B → BAm-1, m ≥ 2 and integer. We regain the usual Thue-Morse sequence for m = 2. We numerically study the changes produced in the localization properties of the I (ω) electric current function with increasing m values. We demonstrate that the m = 2 case does not belong to the family m ≥ 3, because when m changes from m = 2 to m = 3, the number of extended states decreases significantly. However, for m ≫ 3, the localization properties become similar to the m = 2 case. Also, the frequency averaged transmission coefficient shows a strong dependence from the N system size and from the m value which characterize each m-tupling sequence. In addition, for all m value studied, using the scaling behavior of the ξ (ω) normalized participation number, the Rq (ω) Rényi entropies and the μq (ω) moments, we have demonstrated the existence of extended states for certain specific frequencies.

  3. Radiation loss of planar surface plasmon polaritons transmission lines at microwave frequencies.

    PubMed

    Xu, Zhixia; Li, Shunli; Yin, Xiaoxing; Zhao, Hongxin; Liu, Leilei

    2017-07-21

    Radiation loss of a typical spoof surface plasmon polaritons (SSPPs) transmission line (TL) is investigated in this paper. A 325 mm-long SSPPs TL is designed and fabricated. Simulated results show that radiation loss contributes more to transmission loss than dielectric loss and conductor loss from 2 GHz to 10 GHz. Radiation loss of the SSPPs TL could be divided into two parts, one is caused by the input mode converter, and the other is caused by the corrugated metallic strip. This paper explains mechanisms of radiation loss from different parts, designs a loaded SSPPs TL with a series of resistors to absorb electromagnetic energy on corrugated metallic strip, and then discriminates radiation loss from the input mode converter, proposes the concept of average radiation length (ARL) to evaluate radiation loss from SSPPs of finite length, and concludes that radiation loss is mainly caused by corrugated structure of finite length at low frequency band and by the input mode converter at high frequency band. To suppress radiation loss, a mixed slow wave TL based on the combination of coplanar waveguides (CPWs) and SSPPs is presented. The designed structure, sample fabrication and experimental verification are discussed.

  4. Thin CVD-diamond RF Pill-Box vacuum windows for LHCD systems

    NASA Astrophysics Data System (ADS)

    Ravera, G. L.; Ceccuzzi, S.; Cardinali, A.; Cesario, R.; Mirizzi, F.; Schettini, G.; Tuccillo, A. A.

    2014-02-01

    The preliminary assessment of a Lower Hybrid Current Drive (LHCD) system for the DEMOnstration power plant (DEMO) is mainly focused on the R&D needs of the less conventional RF components of the Main Transmission Line (MTL) and of the launcher. 500 kW, CW klystrons will be used to deliver the RF power to independent Passive Active Multijunction (PAM) launcher modules at 5 GHz. This paper describes the criteria followed to investigate the optimum solution for the RF window used as vacuum barrier between the MTL and the launcher, an open issue in the LHCD system for ITER too. The best candidate, capable of withstanding a power level of, or above, 0.5 MW in CW operation and to satisfy the electrical and thermonuclear requirements, is a Pill-Box assembly, based on a thin single disk of CVD-diamond as dielectric, water cooled at the edge. A thickness of 3 mm, much shorter than half a wavelength of the TE°11 mode in the dielectric as in the conventional window (unfeasible and too expensive with CVD-diamond at these frequencies), is sufficient to limit the exerted stress at the edge under the fracture stress for a maximum pressure applied of 0.9 MPa. In this paper the simulation results of conventional and thin CVD-diamond vacuum windows are presented comparing S-parameters, losses and electric fields in both matching condition and with VSWR = 2, using WR284 and WR229 as input/output rectangular waveguide.

  5. Indian Vacuum Society: The Indian Vacuum Society

    NASA Astrophysics Data System (ADS)

    Saha, T. K.

    2008-03-01

    The Indian Vacuum Society (IVS) was established in 1970. It has over 800 members including many from Industry and R & D Institutions spread throughout India. The society has an active chapter at Kolkata. The society was formed with the main aim to promote, encourage and develop the growth of Vacuum Science, Techniques and Applications in India. In order to achieve this aim it has conducted a number of short term courses at graduate and technician levels on vacuum science and technology on topics ranging from low vacuum to ultrahigh vacuum So far it has conducted 39 such courses at different parts of the country and imparted training to more than 1200 persons in the field. Some of these courses were in-plant training courses conducted on the premises of the establishment and designed to take care of the special needs of the establishment. IVS also regularly conducts national and international seminars and symposia on vacuum science and technology with special emphasis on some theme related to applications of vacuum. A large number of delegates from all over India take part in the deliberations of such seminars and symposia and present their work. IVS also arranges technical visits to different industries and research institutes. The society also helped in the UNESCO sponsored post-graduate level courses in vacuum science, technology and applications conducted by Mumbai University. The society has also designed a certificate and diploma course for graduate level students studying vacuum science and technology and has submitted a syllabus to the academic council of the University of Mumbai for their approval, we hope that some colleges affiliated to the university will start this course from the coming academic year. IVS extended its support in standardizing many of the vacuum instruments and played a vital role in helping to set up a Regional Testing Centre along with BARC. As part of the development of vacuum education, the society arranges the participation of

  6. Gamma-Ray Pulsar Light Curves in Vacuum and Force-Free Geometry

    NASA Technical Reports Server (NTRS)

    Harding, Alice K.; DeCesar, Megan E.; Miller, M. Coleman; Kalapotharakos, Constantinos; Contopoulos, Ioannis

    2011-01-01

    Recent studies have shown that gamma-ray pulsar light curves are very sensitive to the geometry of the pulsar magnetic field. Pulsar magnetic field geometries, such as the retarded vacuum dipole and force-free magnetospheres have distorted polar caps that are offset from the magnetic axis in the direction opposite to rotation. Since this effect is due to the sweepback of field lines near the light cylinder, offset polar caps are a generic property of pulsar magnetospheres and their effects should be included in gamma-ray pulsar light curve modeling. In slot gap models (having two-pole caustic geometry), the offset polar caps cause a strong azimuthal asymmetry of the particle acceleration around the magnetic axis. We have studied the effect of the offset polar caps in both retarded vacuum dipole and force-free geometry on the model high-energy pulse profiles. We find that, compared to the profiles derived from symmetric caps, the flux in the pulse peaks, which are caustics formed along the trailing magnetic field lines, increases significantly relative to the off-peak emission, formed along leading field lines. The enhanced contrast produces improved slot gap model fits to Fermi pulsar light curves like Vela, with vacuum dipole fits being more favorable.

  7. Vacuum ultraviolet spectra of uranium hexafluoride/argon mixtures

    NASA Technical Reports Server (NTRS)

    Krascella, N. L.

    1976-01-01

    The transmission properties of room temperature helium at pressures up to 20 atmospheres were determined in the wavelength range from 80 to 300 nm. Similarly, the transmission properties of uranium hexafluoride at 393 K (pressures less than 1.0 mm) were determined in the wavelength range from 80 to about 120 nm. The results show that high pressure helium is sufficiently transparent in the vacuum ultraviolet region (provided trace contaminants are removed) to be utilized as a transparent purge gas in future fissioning gaseous uranium plasma reactor experiments. Absorption cross sections for uranium hexafluoride were calculated from the data between 80 and 120 nm and were of the order of 10 to the -17 power sq cm.

  8. Reconfigurable Transmission Line for a Series-Fed Ku-Band Phased Array Using a Single Feed

    NASA Technical Reports Server (NTRS)

    Host, Nicholas K.; Chen, Chi-Chih; Volakis, John L.; Miranda. Felix, A.

    2013-01-01

    The paper presents a novel approach to realize a lowcost phased array using a simple feeding mechanism. Specifically, a single coplanar stripline (CPS) transmission line is used to feed the antenna array elements. By controlling the CPS's dielectric properties using a movable dielectric plunger, scanning is achieved. Due to its simplicity, single feed, and no phase shifters, this approach leads to a dramatic reduction in cost which does not scale for larger arrays.

  9. Medium frequency propagation characteristics of different transmission lines in an underground coal mine

    PubMed Central

    Li, Jingcheng; Waynert, Joseph A.; Whisner, Bruce G.

    2015-01-01

    A medium frequency (MF) communication system operating in an underground coal mine couples its signals to a long conductor, which acts as an MF transmission line (TL) in a tunnel to permit communications among transceivers along the line. The TL is generally the longest signal path for the system, and its propagation characteristics will have a major impact on the performance of the MF communication system. In this study, the propagation characteristics of three types of MF TLs in two layouts—on the roof and on the floor of a coal mine tunnel—were obtained in an effort to understand the propagation characteristics of different TLs in different locations. The study confirmed a low MF signal loss on all of these TLs. The study also found that the TLs in different layouts had substantially different propagation characteristics. The propagation characteristics of these different TLs in different layouts are presented in the paper. PMID:26203349

  10. Multi-scale modelling of supercapacitors: From molecular simulations to a transmission line model

    NASA Astrophysics Data System (ADS)

    Pean, C.; Rotenberg, B.; Simon, P.; Salanne, M.

    2016-09-01

    We perform molecular dynamics simulations of a typical nanoporous-carbon based supercapacitor. The organic electrolyte consists in 1-ethyl-3-methylimidazolium and hexafluorophosphate ions dissolved in acetonitrile. We simulate systems at equilibrium, for various applied voltages. This allows us to determine the relevant thermodynamic (capacitance) and transport (in-pore resistivities) properties. These quantities are then injected in a transmission line model for testing its ability to predict the charging properties of the device. The results from this macroscopic model are in good agreement with non-equilibrium molecular dynamics simulations, which validates its use for interpreting electrochemical impedance experiments.

  11. Precision optical slit for high heat load or ultra high vacuum

    DOEpatents

    Andresen, Nord C.; DiGennaro, Richard S.; Swain, Thomas L.

    1995-01-01

    This invention relates generally to slits used in optics that must be precisely aligned and adjusted. The optical slits of the present invention are useful in x-ray optics, x-ray beam lines, optical systems in which the entrance slit is critical for high wavelength resolution. The invention is particularly useful in ultra high vacuum systems where lubricants are difficult to use and designs which avoid the movement of metal parts against one another are important, such as monochrometers for high wavelength resolution with ultra high vacuum systems. The invention further relates to optical systems in which temperature characteristics of the slit materials is important. The present invention yet additionally relates to precision slits wherein the opposing edges of the slit must be precisely moved relative to a center line between the edges with each edge retaining its parallel orientation with respect to the other edge and/or the center line.

  12. SCOUT: a small vacuum chamber for nano-wire grid polarizer tests in the ultraviolet band

    NASA Astrophysics Data System (ADS)

    Landini, F.; Pancrazzi, M.; Totaro, M.; Pennelli, G.; Romoli, M.

    2012-01-01

    Within the Section of Astronomy of the Department of Physics and Astronomy of the University of Firenze, Italy), the XUVLab laboratory is active since 1998 dedicated to technological development, mainly UV oriented. The technological research is focused both on electronics and optics. Our last approach is dedicated to the development of innovative wiregrid polarizers optimized to work in transmission at 121.6 nm. The manufacturing of such optical devices requires advanced technological expertise and suitable experimental structures. First, nanotechnology capability is necessary, in order to build several tiny parallel conductive lines separated by tens of nanometers on wide areas to be macroscopically exploitable in an optical laboratory. Moreover, the characterization of such an advanced optical device has to be performed in vacuum, being air absorptive at 121.6 nm. A dedicated small vacuum chamber, SCOUT (Small Chamber for Optical UV Tests) was developed within our laboratory in order to perform practical and fast measurements. SCOUT hosts an optical bench and is equipped with several opening flanges, in order to be as flexible as possible. The flexibility that has been reached with SCOUT allows us to use the chamber beyond the goals it was thought for. It is exploitable by whatever compact (within 1 m) optical experiment that investigates the UV band of the spectrum.

  13. Characterization of a microwave-excited atmospheric-pressure argon plasma jet using two-parallel-wires transmission line resonator

    NASA Astrophysics Data System (ADS)

    Choi, J.; Eom, I. S.; Kim, S. J.; Kwon, Y. W.; Joh, H. M.; Jeong, B. S.; Chung, T. H.

    2017-09-01

    This paper presents a method to produce a microwave-excited atmospheric-pressure plasma jet (ME-APPJ) with argon. The plasma was generated by a microwave-driven micro-plasma source that uses a two-parallel-wire transmission line resonator (TPWR) operating at around 900 MHz. The TPWR has a simple structure and is easier to fabricate than coaxial transmission line resonator (CTLR) devices. In particular, the TPWR can sustain more stable ME-APPJ than the CTLR can because the gap between the electrodes is narrower than that in the CTLR. In experiments performed with an Ar flow rate from 0.5 to 8.0 L.min-1 and an input power from 1 to 6 W, the rotational temperature was determined by comparing the measured and simulated spectra of rotational lines of the OH band and the electron excitation temperature determined by the Boltzmann plot method. The rotational temperature obtained from OH(A-X) spectra was 700 K to 800 K, whereas the apparent gas temperature of the plasma jet remains lower than ˜325 K, which is compatible with biomedical applications. The electron number density was determined using the method based on the Stark broadening of the hydrogen Hβ line, and the measured electron density ranged from 6.5 × 1014 to 7.6 × 1014 cm-3. TPWR ME-APPJ can be operated at low flows of the working gas and at low power and is very stable and effective for interactions of the plasma with cells.

  14. Design of large vacuum chamber for VEC superconducting cyclotron beam line switching magnet

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Sumantra; Nandi, Chinmoy; Gayen, Subhasis; Roy, Suvadeep; Mishra, Santosh Kumar; Ramrao Bajirao, Sanjay; Pal, Gautam; Mallik, C.

    2012-11-01

    VEC K500 superconducting cyclotron will be used to accelerate heavy ion. The accelerated beam will be transported to different beam halls by using large switching magnets. The vacuum chamber for the switching magnet is around 1000 mm long. It has a height of 85 mm and width varying from 100 mm to 360 mm. The material for the chamber has been chosen as SS304.The material for the vacuum chamber for the switching magnet has been chosen as SS304. Design of the vessel was done as per ASME Boiler and Pressure Vessel Code, Section VIII, Division 1. It was observed that primary stress values exceed the allowable limit. Since, the magnet was already designed with a fixed pole gap; increase of the vacuum chamber plate thickness restricts the space for beam transport. Design was optimized using stress analysis software ANSYS. Analysis was started using plate thickness of 4 mm. The stress was found higher than the allowable level. The analysis was repeated by increasing plate thickness to 6 mm, resulting in the reduction of stress level below the allowable level. In order to reduce the stress concentration due to sharp bend, chamfering was done at the corner, where the stress level was higher. The thickness of the plate at the corner was increased from 6 mm to 10 mm. These measures resulted in reduction of localized stress.

  15. Inexpensive cryogenic insulation replaces vacuum jacketed line

    NASA Technical Reports Server (NTRS)

    Fuchs, C. E.

    1967-01-01

    Commercially available aluminized Mylar, cork and fiber glass form a multilayered sealed system and provide rugged and economical field installed insulation for cryogenic /liquid nitrogen or oxygen/ pipe lines in an exposed environment.

  16. Potential uses of vacuum bubbles in noise and vibration control

    NASA Technical Reports Server (NTRS)

    Ver, Istvan L.

    1989-01-01

    Vacuum bubbles are new acoustic elements which are dynamically more compliant than the gas volume they replace, but which are statically robust. They are made of a thin metallic shell with vacuum in their cavity. Consequently, they pose no danger in terms of contamination or fire hazard. The potential of the vacuum bubble concept for noise and vibration control was assessed with special emphases on spacecraft and aircraft applications. The following potential uses were identified: (1) as a cladding, to reduce sound radiation of vibrating surfaces and the sound excitation of structures, (2) as a screen, to reflect or absorb an incident sound wave, and (3) as a liner, to increase low frequency sound transmission loss of double walls and to increase the low frequency sound attenuation of muffler baffles. It was found that geometric and material parameters must be controlled to a very high accuracy to obtain optimal performance and that performance is highly sensitive to variations in static pressure. Consequently, it was concluded that vacuum bubbles have more potential in spacecraft applications where static pressure is controlled more than in aircraft applications where large fluctuations in static pressure are common.

  17. Line spectrum and ion temperature measurements from tungsten ions at low ionization stages in large helical device based on vacuum ultraviolet spectroscopy in wavelength range of 500-2200 Å.

    PubMed

    Oishi, T; Morita, S; Huang, X L; Zhang, H M; Goto, M

    2014-11-01

    Vacuum ultraviolet spectra of emissions released from tungsten ions at lower ionization stages were measured in the Large Helical Device (LHD) in the wavelength range of 500-2200 Å using a 3 m normal incidence spectrometer. Tungsten ions were distributed in the LHD plasma by injecting a pellet consisting of a small piece of tungsten metal and polyethylene tube. Many lines having different wavelengths from intrinsic impurity ions were observed just after the tungsten pellet injection. Doppler broadening of a tungsten candidate line was successfully measured and the ion temperature was obtained.

  18. On the dynamic response of pressure transmission lines in the research of helium-charged free piston Stirling engines

    NASA Technical Reports Server (NTRS)

    Miller, Eric L.; Dudenhoefer, James E.

    1989-01-01

    In free piston Stirling engine research the integrity of both amplitude and phase of the dynamic pressure measurements is critical to the characterization of cycle dynamics and thermodynamics. It is therefore necessary to appreciate all possible sources of signal distortion when designing pressure measurement systems for this type of research. The signal distortion inherent to pressure transmission lines is discussed. Based on results from classical analysis, guidelines are formulated to describe the dynamic response properties of a volume-terminated transmission tube for applications involving helium-charged free piston Stirling engines. The scope and limitations of the dynamic response analysis are considered.

  19. Citizens, farmers fight huge transmission lines

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

    Brummer, J.

    1982-02-01

    Opposition to high tension power lines with a 20-story towers is growing as coalitions of farmers and advocates of safe energy respond with legal intervention and sabotage, and sometimes with success. Examples of citizen action are the efforts opposing a 450 kilovolt direct current line connecting the US with Quebec Hydro and another opposing a 500 kilovolt alternating current line from Georgia Power Co.'s nuclear plants to Florida. The opposition derives partly from evidence of health hazards to humans and adverse effects on livestock. High voltage lines are felt to symbolize a utility and regulatory failure to assess the recentmore » decline in power demand. It is stated that administration efforts to outlaw organized resistence will not deter the opposition, which cites instances of ground shock, aborted and stillborn cattle, physical irritants, and other phenomena. The General Assembly to Stop the Powerline (GASP) objects to the guinea pig position forced upon residents by the utilities. 6 references. (DCK)« less

  20. Alleviating line overload by line switching

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

    Brown, H.E.

    1988-01-01

    Traditionally, the method used by power system dispatchers to reduce or to eliminate line overload conditions has been to shift generation. Such shifts are generally in conflict with the carefully considered economic dispatch of generation. A proper generation schedule has taken into account many factors, such as generator limits, transmission penalties, incremental costs, var support, and system security. Any deviation from this schedule results in increased production cost. Recently, consideration has been given to alleviating line overloads by line switching. In many situations, line switching does not greatly change the transmission penalty factors and, therefore, can be undertaken without seriouslymore » affecting the economic dispatch. It would be convenient for system operators to have a fast, easy-to-operate computer and program available for the evaluation of the efficacy of a line removal (or addition) in dealing with an overload. It is imperative that the operator be properly advised, that a certain line switching reduces the overload and not aggravate the condition. After it has been determined that a line opening (or closing) produces the desired effect, the operator still must assess the consequence of such switching on system security before actually taking such action.« less

  1. Voltage measurements at the vacuum post-hole convolute of the Z pulsed-power accelerator

    DOE PAGES

    Waisman, E. M.; McBride, R. D.; Cuneo, M. E.; ...

    2014-12-08

    Presented are voltage measurements taken near the load region on the Z pulsed-power accelerator using an inductive voltage monitor (IVM). Specifically, the IVM was connected to, and thus monitored the voltage at, the bottom level of the accelerator’s vacuum double post-hole convolute. Additional voltage and current measurements were taken at the accelerator’s vacuum-insulator stack (at a radius of 1.6 m) by using standard D-dot and B-dot probes, respectively. During postprocessing, the measurements taken at the stack were translated to the location of the IVM measurements by using a lossless propagation model of the Z accelerator’s magnetically insulated transmission lines (MITLs)more » and a lumped inductor model of the vacuum post-hole convolute. Across a wide variety of experiments conducted on the Z accelerator, the voltage histories obtained from the IVM and the lossless propagation technique agree well in overall shape and magnitude. However, large-amplitude, high-frequency oscillations are more pronounced in the IVM records. It is unclear whether these larger oscillations represent true voltage oscillations at the convolute or if they are due to noise pickup and/or transit-time effects and other resonant modes in the IVM. Results using a transit-time-correction technique and Fourier analysis support the latter. Regardless of which interpretation is correct, both true voltage oscillations and the excitement of resonant modes could be the result of transient electrical breakdowns in the post-hole convolute, though more information is required to determine definitively if such breakdowns occurred. Despite the larger oscillations in the IVM records, the general agreement found between the lossless propagation results and the results of the IVM shows that large voltages are transmitted efficiently through the MITLs on Z. These results are complementary to previous studies [R.D. McBride et al., Phys. Rev. ST Accel. Beams 13, 120401 (2010)] that showed

  2. Flexible superconducting Nb transmission lines on thin film polyimide for quantum computing applications

    NASA Astrophysics Data System (ADS)

    Tuckerman, David B.; Hamilton, Michael C.; Reilly, David J.; Bai, Rujun; Hernandez, George A.; Hornibrook, John M.; Sellers, John A.; Ellis, Charles D.

    2016-08-01

    We describe progress and initial results achieved towards the goal of developing integrated multi-conductor arrays of shielded controlled-impedance flexible superconducting transmission lines with ultra-miniature cross sections and wide bandwidths (dc to >10 GHz) over meter-scale lengths. Intended primarily for use in future scaled-up quantum computing systems, such flexible thin-film niobium/polyimide ribbon cables could provide a physically compact and ultra-low thermal conductance alternative to the rapidly increasing number of discrete coaxial cables that are currently used by quantum computing experimentalists to transmit signals between the several low-temperature stages (from ˜4 K down to ˜20 mK) of a dilution refrigerator. We have concluded that these structures are technically feasible to fabricate, and so far they have exhibited acceptable thermo-mechanical reliability. S-parameter results are presented for individual 2-metal layer Nb microstrip structures having 50 Ω characteristic impedance; lengths ranging from 50 to 550 mm were successfully fabricated. Solderable pads at the end terminations allowed testing using conventional rf connectors. Weakly coupled open-circuit microstrip resonators provided a sensitive measure of the overall transmission line loss as a function of frequency, temperature, and power. Two common microelectronic-grade polyimide dielectrics, one conventional and the other photo-definable (PI-2611 and HD-4100, respectively) were compared. Our most striking result, not previously reported to our knowledge, was that the dielectric loss tangents of both polyimides, over frequencies from 1 to 20 GHz, are remarkably low at deep cryogenic temperatures, typically 100× smaller than corresponding room temperature values. This enables fairly long-distance (meter-scale) transmission of microwave signals without excessive attenuation, and also permits usefully high rf power levels to be transmitted without creating excessive dielectric

  3. Atmospheres and spectra of strongly magnetized neutron stars - II. The effect of vacuum polarization

    NASA Astrophysics Data System (ADS)

    Ho, Wynn C. G.; Lai, Dong

    2003-01-01

    We study the effect of vacuum polarization on the atmosphere structure and radiation spectra of neutron stars with surface magnetic fields B= 1014-1015 G, as appropriate for magnetars. Vacuum polarization modifies the dielectric property of the medium and gives rise to a resonance feature in the opacity; this feature is narrow and occurs at a photon energy that depends on the plasma density. Vacuum polarization can also induce resonant conversion of photon modes via a mechanism analogous to the Mikheyev-Smirnov-Wolfenstein (MSW) mechanism for neutrino oscillation. We construct atmosphere models in radiative equilibrium with an effective temperature of a few ×106 K by solving the full radiative transfer equations for both polarization modes in a fully ionized hydrogen plasma. We discuss the subtleties in treating the vacuum polarization effects in the atmosphere models and present approximate solutions to the radiative transfer problem which bracket the true answer. We show from both analytic considerations and numerical calculations that vacuum polarization produces a broad depression in the X-ray flux at high energies (a few keV <~E<~ a few tens of keV) as compared to models without vacuum polarization; this arises from the density dependence of the vacuum resonance feature and the large density gradient present in the atmosphere. Thus the vacuum polarization effect softens the high-energy tail of the thermal spectrum, although the atmospheric emission is still harder than the blackbody spectrum because of the non-grey opacities. We also show that the depression of continuum flux strongly suppresses the equivalent width of the ion cyclotron line and therefore makes the line more difficult to observe.

  4. Precision optical slit for high heat load or ultra high vacuum

    DOEpatents

    Andresen, N.C.; DiGennaro, R.S.; Swain, T.L.

    1995-01-24

    This invention relates generally to slits used in optics that must be precisely aligned and adjusted. The optical slits of the present invention are useful in x-ray optics, x-ray beam lines, optical systems in which the entrance slit is critical for high wavelength resolution. The invention is particularly useful in ultra high vacuum systems where lubricants are difficult to use and designs which avoid the movement of metal parts against one another are important, such as monochromators for high wavelength resolution with ultra high vacuum systems. The invention further relates to optical systems in which temperature characteristics of the slit materials is important. The present invention yet additionally relates to precision slits wherein the opposing edges of the slit must be precisely moved relative to a center line between the edges with each edge retaining its parallel orientation with respect to the other edge and/or the center line. 21 figures.

  5. Dynamics of vacuum-sealed, double-leaf partitions

    NASA Astrophysics Data System (ADS)

    Kavanaugh, Joshua Stephen

    The goal of this research is to investigate the feasibility and potential effectiveness of using vacuum-sealed, double-leaf partitions for applications in noise control. Substantial work has been done previously on double-leaf partitions where the acoustics of the inner chamber and mechanical vibrations of structural supports are passively and actively controlled. The work presented here is unique in that the proposed system aims to eliminate the need for active acoustic control of transmitted acoustic energy by removing all the air between the two panels of the double partition. Therefore, the only remaining energy paths would be along the boundary and at the points where there are intermediate structural supports connecting the two panels. The eventual goal of the research is to develop a high-loss double-leaf partition that simplifies active control by removing the need for control of the air cavity and channeling all the energy into discrete structural paths. The work presented here is a first step towards the goal of designing a high-loss, actively-controlled double-leaf partition with an air-evacuated inner chamber. One experiment is conducted to investigate the effects of various levels of vacuum on the response of a double-leaf partition whose panels are mechanically coupled only at the boundary. Another experiment is conducted which investigates the effect of changing the stiffness of an intermediate support coupling the two panels of a double-leaf partition in which a vacuum has been applied to the inner cavity. The available equipment was able to maintain a 99% vacuum between the panels. Both experiments are accompanied by analytical models used to investigate the importance of various dynamic parameters. Results show that the vacuum-sealed system shows some potential for increased transmission loss, primarily by the changing the natural frequencies of the double-leaf partition.

  6. K-Band Power Enbedded Transmission Line (ETL) MMIC Amplifiers for Satellite Communication Applications

    NASA Technical Reports Server (NTRS)

    Tserng, Hua-Quen; Ketterson, Andrew; Saunier, Paul; McCarty, Larry; Davis, Steve

    1998-01-01

    The design, fabrication, and performance of K-band high-efficiency, linear power pHEMT amplifiers implemented in Embedded Transmission Line (ETL) MMIC configuration with unthinned GaAs substrate and topside grounding are reported. A three-stage amplifier achieved a power-added efficiency of 40.5% with 264 mW output at 20.2 GHz. The linear gain is 28.5 dB with 1-dB gain compression output power of 200 mW and 31% power-added efficiency. The carrier-to-third-order intermodulation ratio is approx. 20 dBc at the 1-dB compression point. A RF functional yield of more than 90% has been achieved.

  7. 77 FR 64333 - Relocation of Transmission Lines for the U.S. 93 Boulder City Bypass Project, Boulder County, NV...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-19

    ... Standard 13 ``Environmental Quality Protection.'' Long-term operations of the transmission line will follow Western's standard operating procedures and will not be affected by this action. In addition to Construction Standard 13, the following measures apply to the modifications that will be made to Western's...

  8. Numerical Simulation of the Working Process in the Twin Screw Vacuum Pump

    NASA Astrophysics Data System (ADS)

    Lu, Yang; Fu, Yu; Guo, Bei; Fu, Lijuan; Zhang, Qingqing; Chen, Xiaole

    2017-08-01

    Twin screw vacuum pumps inherit the advantages of screw machinery, such as high reliability, stable medium conveying, small vibration, simple and compact structures, convenient operation, etc, which have been widely used in petrochemical and air industry. On the basis of previous studies, this study analyzed the geometric features of variable pitch of the twin screw vacuum pump such as the sealing line, the meshing line and the volume between teeth. The mathematical model of numerical simulation of the twin screw vacuum pump was established. The leakage paths of the working volume including the sealing line and the addendum arc were comprehensively considered. The corresponding simplified geometric model of leakage flow was built up for different leak paths and the flow coefficients were calculated. The flow coefficient value range of different leak paths was given. The results showed that the flow coefficient of different leak paths can be taken as constant value for the studied geometry. The analysis of recorded indicator diagrams showed that the increasing rotational speed can dramatically decrease the exhaust pressure and the lower rotational speed can lead to over-compression. The pressure of the isentropic process which was affected by leakage was higher than the theoretical process.

  9. Predicting the impacts of a high-voltage transmission line on big game hunting opportunities in Western Montana

    Treesearch

    Stewart Allen

    1985-01-01

    The State of Montana, in cooperation with the U.S. Forest Service and Bonneville Power Administration, is conducting a five-vear study on the impacts of a 500-kV transmission line on elk habitat and hunter opportunity. In fall 1983, baseline data on hunting patterns and quality were collected from over 600 hunters interviewed in three western Montana study areas. A...

  10. Economic analysis of transmission line engineering based on industrial engineering

    NASA Astrophysics Data System (ADS)

    Li, Yixuan

    2017-05-01

    The modern industrial engineering is applied to the technical analysis and cost analysis of power transmission and transformation engineering. It can effectively reduce the cost of investment. First, the power transmission project is economically analyzed. Based on the feasibility study of power transmission and transformation project investment, the proposal on the company system cost management is put forward through the economic analysis of the effect of the system. The cost management system is optimized. Then, through the cost analysis of power transmission and transformation project, the new situation caused by the cost of construction is found. It is of guiding significance to further improve the cost management of power transmission and transformation project. Finally, according to the present situation of current power transmission project cost management, concrete measures to reduce the cost of power transmission project are given from the two aspects of system optimization and technology optimization.

  11. Vacuum mechatronics

    NASA Technical Reports Server (NTRS)

    Hackwood, Susan; Belinski, Steven E.; Beni, Gerardo

    1989-01-01

    The discipline of vacuum mechatronics is defined as the design and development of vacuum-compatible computer-controlled mechanisms for manipulating, sensing and testing in a vacuum environment. The importance of vacuum mechatronics is growing with an increased application of vacuum in space studies and in manufacturing for material processing, medicine, microelectronics, emission studies, lyophylisation, freeze drying and packaging. The quickly developing field of vacuum mechatronics will also be the driving force for the realization of an advanced era of totally enclosed clean manufacturing cells. High technology manufacturing has increasingly demanding requirements for precision manipulation, in situ process monitoring and contamination-free environments. To remove the contamination problems associated with human workers, the tendency in many manufacturing processes is to move towards total automation. This will become a requirement in the near future for e.g., microelectronics manufacturing. Automation in ultra-clean manufacturing environments is evolving into the concept of self-contained and fully enclosed manufacturing. A Self Contained Automated Robotic Factory (SCARF) is being developed as a flexible research facility for totally enclosed manufacturing. The construction and successful operation of a SCARF will provide a novel, flexible, self-contained, clean, vacuum manufacturing environment. SCARF also requires very high reliability and intelligent control. The trends in vacuum mechatronics and some of the key research issues are reviewed.

  12. Self-tuning wireless power transmission scheme based on on-line scattering parameters measurement and two-side power matching.

    PubMed

    Luo, Yanting; Yang, Yongmin; Chen, Zhongsheng

    2014-04-10

    Sub-resonances often happen in wireless power transmission (WPT) systems using coupled magnetic resonances (CMR) due to environmental changes, coil movements or component degradations, which is a serious challenge for high efficiency power transmission. Thus self-tuning is very significant to keep WPT systems following strongly magnetic resonant conditions in practice. Traditional coupled-mode ways is difficult to solve this problem. In this paper a two-port power wave model is presented, where power matching and the overall systemic power transmission efficiency are firstly defined by scattering (S) parameters. Then we propose a novel self-tuning scheme based on on-line S parameters measurements and two-side power matching. Experimental results testify the feasibility of the proposed method. These findings suggest that the proposed method is much potential to develop strongly self-adaptive WPT systems with CMR.

  13. Solid-state repetitive generator with a gyromagnetic nonlinear transmission line operating as a peak power amplifier

    NASA Astrophysics Data System (ADS)

    Gusev, A. I.; Pedos, M. S.; Rukin, S. N.; Timoshenkov, S. P.

    2017-07-01

    In this work, experiments were made in which gyromagnetic nonlinear transmission line (NLTL) operates as a peak power amplifier of the input pulse. At such an operating regime, the duration of the input pulse is close to the period of generated oscillations, and the main part of the input pulse energy is transmitted only to the first peak of the oscillations. Power amplification is achieved due to the voltage amplitude of the first peak across the NLTL output exceeding the voltage amplitude of the input pulse. In the experiments, the input pulse with an amplitude of 500 kV and a half-height pulse duration of 7 ns is applied to the NLTL with a natural oscillation frequency of ˜300 MHz. At the output of the NLTL in 40 Ω coaxial transmission line, the pulse amplitude is increased to 740 kV and the pulse duration is reduced to ˜2 ns, which correspond to power amplification of the input pulse from ˜6 to ˜13 GW. As a source of input pulses, a solid-state semiconductor opening switch generator was used, which allowed carrying out experiments at pulse repetition frequency up to 1 kHz in the burst mode of operation.

  14. Application of vision measurements for modal analysis of wires for the purpose of overhead transmission lines monitoring

    NASA Astrophysics Data System (ADS)

    Mendrok, Krzysztof; Dworakowski, Ziemowit; Holak, Krzysztof; Kohut, Piotr

    2017-05-01

    Overhead transmission power lines are still one of the crucial elements of electro-energetic system. There are obvious advantages of using overhead transmission in the distribution of electricity. The amount of energy transported through a power line is determined by the distance between the wire and the ground or other objects placed beneath it (eg. trees). This distance is not fixed and depends on the overhang of the wire. This, in turn, is determined by many factors such as ambient temperature, humidity, precipitation, the value of current flowing through the wire. In order to optimize the wires electrical load, the monitoring of that overhang is required. One way to measure it is the non-contact measurement by vision system. It has the advantage, that using high-speed cameras respectively it also allows for vibration measurement and analysis of dynamic performance. That is very important while the wires are susceptible to the influence of wind, and the resulting vibrations interfere with the correct measurement of the overhang. The paper presents the results of vision measurements of the system vibrations and modal analysis carried out on their basis. The study was conducted on a specially made laboratory stand.

  15. Line spectrum and ion temperature measurements from tungsten ions at low ionization stages in large helical device based on vacuum ultraviolet spectroscopy in wavelength range of 500–2200 Å

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

    Oishi, T., E-mail: oishi@LHD.nifs.ac.jp; Morita, S.; Goto, M.

    2014-11-15

    Vacuum ultraviolet spectra of emissions released from tungsten ions at lower ionization stages were measured in the Large Helical Device (LHD) in the wavelength range of 500–2200 Å using a 3 m normal incidence spectrometer. Tungsten ions were distributed in the LHD plasma by injecting a pellet consisting of a small piece of tungsten metal and polyethylene tube. Many lines having different wavelengths from intrinsic impurity ions were observed just after the tungsten pellet injection. Doppler broadening of a tungsten candidate line was successfully measured and the ion temperature was obtained.

  16. Optimizing the performance of bandpass photon detectors for inverse photoemission: Transmission of alkaline earth fluoride window crystals

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

    Thiede, Christian, E-mail: christian.thiede@uni-muenster.de; Schmidt, Anke B.; Donath, Markus

    2015-08-15

    Bandpass photon detectors are widely used in inverse photoemission in the isochromat mode at energies in the vacuum-ultraviolet spectral range. The energy bandpass of gas-filled counters is usually formed by the ionization threshold of the counting gas as high-pass filter and the transmission cutoff of an alkaline earth fluoride window as low-pass filter. The transmission characteristics of the window have, therefore, a crucial impact on the detector performance. We present transmission measurements in the vacuum-ultraviolet spectral range for alkaline earth fluoride window crystals in the vicinity of the transmission cutoff as a function of crystal purity, surface finish, surface contamination,more » temperature, and thickness. Our findings reveal that the transmission characteristics of the window crystal and, thus, the detector performance depend critically on these window parameters.« less

  17. Natural vacuum electronics

    NASA Technical Reports Server (NTRS)

    Leggett, Nickolaus

    1990-01-01

    The ambient natural vacuum of space is proposed as a basis for electron valves. Each valve is an electron controlling structure similiar to a vacuum tube that is operated without a vacuum sustaining envelope. The natural vacuum electron valves discussed offer a viable substitute for solid state devices. The natural vacuum valve is highly resistant to ionizing radiation, system generated electromagnetic pulse, current transients, and direct exposure to space conditions.

  18. Assessment of penetration through vacuum cleaners and recommendation of wet cyclone technology.

    PubMed

    Seo, Youngjin; Han, Taewon

    2013-04-01

    In many commercial vacuum cleaners, the captured aerosol particles contained in the dust collector may accidentally release from the exhaust filtration owing to leakage or penetration. Vacuum cleaners may cause dust to become airborne by exhausting air that is not completely filtered. This may cause the operator to inhale dust, in turn causing health problems. This study aimed to investigate the dust penetration rates from three commercial vacuum cleaners and suggest the best technique for completely filtering exhaust air using a combination of cyclonic separation and water filtration. The commercial vacuum cleaners were tested inside a custom-built hood, and the exhausted particles were monitored using a sampling probe in conjunction with an aerosol particle sizer Quartzose mineral dusts were added to each vacuum cleaner through the dust transport line. A 2400 L/min wet cyclone was employed as the proposed vacuum cleaner It was designed using Stokes scaling, and its collection characteristics were evaluated using polystyrene latex beads. Surprisingly, the conventional vacuum cleaners failed to capture an overall average of approximately 14% of the particles in the given size range. However, only approximately 3.8% of the collected particles escaped from the vacuum cleaner that used the wet cyclone technology. Thus, the proposed vacuum cleaner should potentially be an effective method for vacuuming household dust. The successful investigation of conventional vacuum cleaners is useful for both manufacturers and users. As an effective vacuum cleaning mechanism, household dust is able to migrate along the thin water, film that forms on the inner walls of the cyclone vacuum cleaner. It collects dust in a small water inflow (3 mL/min), which allows it to capture a higher percentage of contaminants than most of the currently available vacuum cleaners. The significantly low accidental exposure rates achieved by this new vacuum cleaner enable healthy conditions in various

  19. Power line detection system

    DOEpatents

    Latorre, Victor R.; Watwood, Donald B.

    1994-01-01

    A short-range, radio frequency (RF) transmitting-receiving system that provides both visual and audio warnings to the pilot of a helicopter or light aircraft of an up-coming power transmission line complex. Small, milliwatt-level narrowband transmitters, powered by the transmission line itself, are installed on top of selected transmission line support towers or within existing warning balls, and provide a continuous RF signal to approaching aircraft. The on-board receiver can be either a separate unit or a portion of the existing avionics, and can also share an existing antenna with another airborne system. Upon receipt of a warning signal, the receiver will trigger a visual and an audio alarm to alert the pilot to the potential power line hazard.

  20. Power line detection system

    DOEpatents

    Latorre, V.R.; Watwood, D.B.

    1994-09-27

    A short-range, radio frequency (RF) transmitting-receiving system that provides both visual and audio warnings to the pilot of a helicopter or light aircraft of an up-coming power transmission line complex. Small, milliwatt-level narrowband transmitters, powered by the transmission line itself, are installed on top of selected transmission line support towers or within existing warning balls, and provide a continuous RF signal to approaching aircraft. The on-board receiver can be either a separate unit or a portion of the existing avionics, and can also share an existing antenna with another airborne system. Upon receipt of a warning signal, the receiver will trigger a visual and an audio alarm to alert the pilot to the potential power line hazard. 4 figs.

  1. Relevance of nanocomposite packaging on the stability of vacuum-packed dry cured ham.

    PubMed

    Lloret, Elsa; Fernandez, Avelina; Trbojevich, Raul; Arnau, Jacint; Picouet, Pierre A

    2016-08-01

    In this study effects of a novel high barrier multilayer polyamide film containing dispersed nanoclays (PAN) on the stability of vacuum packed dry-cured ham were investigated during 90days refrigerated storage in comparison with non-modified multilayer polyamide (PA) and a commercial high barrier film. Characteristic bands of the mineral in FT-IR spectra confirmed the presence of nanoclays in PAN, enhancing oxygen transmission barrier properties and UV protection. Packaging in PAN films did not originate significant changes on colour or lipid oxidation during prolonged storage of vacuum-packed dry-cured ham. Larger oxygen transmission rates in PA films caused changes in CIE b* during refrigerated storage. Ham quality was not affected by light exposition during 90days and only curing had a significant benefit on colour and TBARS, being cured samples more stable during storage in all the packages used. Packaging of dry-cured ham in PAN was equivalent to commercial high barrier films. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. VACUUM TRAP

    DOEpatents

    Gordon, H.S.

    1959-09-15

    An improved adsorption vacuum trap for use in vacuum systems was designed. The distinguishing feature is the placement of a plurality of torsionally deformed metallic fins within a vacuum jacket extending from the walls to the central axis so that substantially all gas molecules pass through the jacket will impinge upon the fin surfaces. T fins are heated by direct metallic conduction, thereby ol taining a uniform temperature at the adeorbing surfaces so that essentially all of the condensible impurities from the evacuating gas are removed from the vacuum system.

  3. Transmission line pulse system for avalanche characterization of high power semiconductor devices

    NASA Astrophysics Data System (ADS)

    Riccio, Michele; Ascione, Giovanni; De Falco, Giuseppe; Maresca, Luca; De Laurentis, Martina; Irace, Andrea; Breglio, Giovanni

    2013-05-01

    Because of the increasing in power density of electronic devices for medium and high power application, reliabilty of these devices is of great interest. Understanding the avalanche behaviour of a power device has become very important in these last years because it gives an indication of the maximum energy ratings which can be seen as an index of the device ruggedness. A good description of this behaviour is given by the static IV blocking characteristc. In order to avoid self heating, very relevant in high power devices, very short pulses of current have to be used, whose value can change from few milliamps up to tens of amps. The most used method to generate short pulses is the TLP (Transmission Line Pulse) test, which is based on charging the equivalent capacitance of a transmission line to high value of voltage and subsequently discharging it onto a load. This circuit let to obtain very short square pulses but it is mostly used for evaluate the ESD capability of semiconductor and, in this environment, it generates pulses of low amplitude which are not high enough to characterize the avalanche behaviour of high power devices . Advanced TLP circuit able to generate high current are usually very expensive and often suffer of distorption of the output pulse. In this article is proposed a simple, low cost circuit, based on a boosted-TLP configuration, which is capable to produce very square pulses of about one hundreds of nanosecond with amplitude up to some tens of amps. A prototype is implemented which can produce pulses up to 20A of amplitude with 200 ns of duration which can characterize power devices up to 1600V of breakdown voltage. Usage of microcontroller based logic make the circuit very flexible. Results of SPICE simulation are provided, together with experimental results. To prove the effectiveness of the circuit, the I-V blocking characteristics of two commercial devices, namely a 600V PowerMOS and a 1200V Trench-IGBT, are measured at different

  4. Coaxial line configuration for microwave power transmission study of YBa2Cu3O(7-delta) thin films

    NASA Technical Reports Server (NTRS)

    Chorey, C. M.; Miranda, F. A.; Bhasin, K. B.

    1991-01-01

    Microwave transmission measurements through YBa2Cu3O(7-delta) (YBCO) high-transition-temperature superconducting thin films on lanthanum aluminate (LaAlO3) have been performed in a coaxial line at 10 GHz. LaAlO3 substrates were ultrasonically machined into washer-shaped discs, polished, and coated with laser-ablated YBCO. These samples were mounted in a 50-ohm coaxial air line to form a short circuit. The power transmitted through the films as a function of temperature was used to calculate the normal state conductivity and the magnetic penetration depth for the films.

  5. Millimeter wave transmission systems and related devices

    NASA Technical Reports Server (NTRS)

    Hebert, L. M.

    1984-01-01

    A survey was made of the state-of-the-art in millimeter (20 GHz to 300 GHz) wave transmission systems and related devices. The survey includes summaries of analytical studies and theoretical results that were obtained for various transmission line structures. This material was supplemented by further analysis where appropriate. The transmission line structures are evaluated in terms of electrical performance, ease of manufacture, usefulness for building other devices and compatibility with solid state devices. Descriptions of waveguide transmission lines which have commonly been used in the microwave frequency range are provided along with special attention given to the problems that these guides face when their use is extended into the millimeter wave range. Also, guides which have been introduced specifically to satisfy the requirements of millimeter wave transmission are discussed in detail.

  6. Transport of liquid state nitrogen through long length service lines during thermal/vacuum testing. [in a Nimbus 6 satellite

    NASA Technical Reports Server (NTRS)

    Florio, F. A.

    1975-01-01

    Physical and analytical aspects associated with the transport are presented. Included is a definition of the problems and difficulties imposed by the servicing of a typical solid cryogen system, as well as a discussion of the transport requirements and of the rationale which governed their solution. A successful detailed transport configuration is defined, and the application of established mathematics to the design approach is demonstrated. The significance of head pressure, pressure drop, line friction, heat leak, Reynolds number, and the fundamental equilibrium demands of pressure and temperature were examined as they relate to the achievement of liquid state flow. Performance predictions were made for the transport system, and several analytical quantities are tabulated. These data are analyzed and compared with measured and calculated results obtained while actually servicing a solid cryogen system during thermal/vacuum testing.

  7. Vertically aligned gas-insulated transmission line having particle traps at the inner conductor

    DOEpatents

    Dale, Steinar J.

    1984-01-01

    Gas insulated electrical apparatus having first and second conductors separated by an insulating support within an insulating gas environment, and particle traps disposed along the surface of the high potential conductor for trapping and inactivating foreign particles which may be present within the insulating gas medium. Several embodiments of the invention were developed which are particularly suited for vertically aligned gas insulated transmission lines. The particle traps are grooves or cavities formed into the walls of the tubular inner conductor, without extending into the hollow portion of the conductor. In other embodiments, the traps are appendages or insert flanges extending from the inner conductor, with the insulator supports contacting the appendages instead of the inner conductor.

  8. Electron impact excitation of argon in the extreme vacuum ultraviolet

    NASA Technical Reports Server (NTRS)

    Mentall, J. E.; Morgan, H. D.

    1976-01-01

    Polarization-free excitation cross sections in the extreme vacuum ultraviolet have been measured for electron impact on Ar. Observed spectral features were those lines of Ar I and Ar II which lie between 700 and 1100 A. Excitation functions were measured for the Ar I resonance line at 1048 A and the Ar II resonance line at 920 A. Peak cross sections for these two lines were found to be (39.4 plus or minus 7.9) x 10 to the -18th and (6.9 plus or minus 1.4) x 10 to the -18th, respectively. At low energies, excitation of the Ar II resonance line is dominated by an electron exchange transition.

  9. A visual resource management study of alternative dams, reservoirs and highway and transmission line corridors near Copper Creek, Washington

    Treesearch

    John Ady; Brian A. Gray; Grant R. Jones

    1979-01-01

    Three alternative dams have been considered by Seattle City Light for the Skagit River Narrows in the North Cascades National Recreation Area, Washington. The authors assessed the area's existing visual resources, identified three alternative highway and transmission line realignments, evaluated changes in visual character and quality for 13 different combinations...

  10. PORTION OF A LINE (AT LEFT) AND B LINE (AT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    PORTION OF A LINE (AT LEFT) AND B LINE (AT RIGHT) ON GENTLE TERRACE SLOPE. A LINE POLE 75A (LEFT FOREGROUND) HAS ORIGINAL GLASS PIN-TYPE INSULATORS AND INTACT COMMUNICATION LINE CROSS ARM. VIEW TO WEST-SOUTHWEST. - Mystic Lake Hydroelectric Facility, Electric Transmission A Line, Along West Rosebud Creek, Fishtail, Stillwater County, MT

  11. PILOT-SCALE REMOVAL OF FLUORIDE FROM LEGACY PLUTONIUM MATERIALS USING VACUUM SALT DISTILLATION

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

    Pierce, R. A.; Pak, D. J.

    2012-09-11

    Between September 2009 and January 2011, the Savannah River National Laboratory (SRNL) and HB-Line designed, developed, tested, and successfully deployed a system for the distillation of chloride salts. In 2011, SRNL adapted the technology for the removal of fluoride from fluoride-bearing salts. The method involved an in situ reaction between potassium hydroxide (KOH) and the fluoride salt to yield potassium fluoride (KF) and the corresponding oxide. The KF and excess KOH can be distilled below 1000{deg}C using vacuum salt distillation (VSD). The apparatus for vacuum distillation contains a zone heated by a furnace and a zone actively cooled using eithermore » recirculated water or compressed air. During a vacuum distillation operation, a sample boat containing the feed material is placed into the apparatus while it is cool, and the system is sealed. The system is evacuated using a vacuum pump. Once a sufficient vacuum is attaned, heating begins. Volatile salts distill from the heated zone to the cooled zone where they condense, leaving behind the non-volatile material in the feed boat. Studies discussed in this report were performed involving the use of non-radioactive simulants in small-scale and pilot-scale systems as well as radioactive testing of a small-scale system with plutonium-bearing materials. Aspects of interest include removable liner design considerations, boat materials, in-line moisture absorption, and salt deposition.« less

  12. APPLICATION OF VACUUM SALT DISTILLATION TECHNOLOGY FOR THE REMOVAL OF FLUORIDE

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

    Pierce, R.; Pak, D.

    2011-08-10

    Vacuum distillation of chloride salts from plutonium oxide (PuO{sub 2}) and simulant PuO{sub 2} has been previously demonstrated at Department of Energy (DOE) sites using kilogram quantities of chloride salt. The apparatus for vacuum distillation contains a zone heated using a furnace and a zone actively cooled using either recirculated water or compressed air. During a vacuum distillation operation, a sample boat containing the feed material is placed into the apparatus while it is cool, and the system is sealed. The system is evacuated using a vacuum pump. Once a sufficient vacuum is attained, heating begins. Volatile salts distill frommore » the heated zone to the cooled zone where they condense, leaving behind the non-volatile materials in the feed boat. The application of vacuum salt distillation (VSD) is of interest to the HB-Line Facility and the MOX Fuel Fabrication Facility (MFFF) at the Savannah River Site (SRS). Both facilities are involved in efforts to disposition excess fissile materials. Many of these materials contain chloride and fluoride salt concentrations which make them unsuitable for dissolution without prior removal of the chloride and fluoride salts. Between September 2009 and January 2011, the Savannah River National Laboratory (SRNL) and HB-Line designed, developed, tested, and successfully deployed a system for the distillation of chloride salts. Subsequent efforts are attempting to adapt the technology for the removal of fluoride. Fluoride salts of interest are less-volatile than the corresponding chloride salts. Consequently, an alternate approach is required for the removal of fluoride without significantly increasing the operating temperature. HB-Line Engineering requested SRNL to evaluate and demonstrate the feasibility of an alternate approach using both non-radioactive simulants and plutonium-bearing materials. Whereas the earlier developments targeted the removal of sodium chloride (NaCl) and potassium chloride (KCl), the

  13. Multipactor threshold calculation of coaxial transmission lines in microwave applications with nonstationary statistical theory

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

    Lin, S.; Li, Y.; Liu, C.

    2015-08-15

    This paper presents a statistical theory for the initial onset of multipactor breakdown in coaxial transmission lines, taking both the nonuniform electric field and random electron emission velocity into account. A general numerical method is first developed to construct the joint probability density function based on the approximate equation of the electron trajectory. The nonstationary dynamics of the multipactor process on both surfaces of coaxial lines are modelled based on the probability of various impacts and their corresponding secondary emission. The resonant assumption of the classical theory on the independent double-sided and single-sided impacts is replaced by the consideration ofmore » their interaction. As a result, the time evolutions of the electron population for exponential growth and absorption on both inner and outer conductor, in response to the applied voltage above and below the multipactor breakdown level, are obtained to investigate the exact mechanism of multipactor discharge in coaxial lines. Furthermore, the multipactor threshold predictions of the presented model are compared with experimental results using measured secondary emission yield of the tested samples which shows reasonable agreement. Finally, the detailed impact scenario reveals that single-surface multipactor is more likely to occur with a higher outer to inner conductor radius ratio.« less

  14. Attosecond transient absorption of argon atoms in the vacuum ultraviolet region: line energy shifts versus coherent population transfer

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

    Cao, Wei; Warrick, Erika R.; Neumark, Daniel M.

    Using attosecond transient absorption, the dipole response of an argon atom in the vacuum ultraviolet (VUV) region is studied when an external electromagnetic field is present. An isolated attosecond VUV pulse populates Rydberg states lying 15 eV above the argon ground state. A synchronized few-cycle near infrared (NIR) pulse modifies the oscillating dipoles of argon impulsively, leading to alterations in the VUV absorption spectra. As the NIR pulse is delayed with respect to the VUV pulse, multiple features in the absorption profile emerge simultaneously including line broadening, sideband structure, sub-cycle fast modulations, and 5-10 fs slow modulations. These features indicatemore » the coexistence of two general processes of the light-matter interaction: the energy shift of individual atomic levels and coherent population transfer between atomic eigenstates, revealing coherent superpositions. Finally, an intuitive formula is derived to treat both effects in a unifying framework, allowing one to identify and quantify the two processes in a single absorption spectrogram.« less

  15. Attosecond transient absorption of argon atoms in the vacuum ultraviolet region: line energy shifts versus coherent population transfer

    NASA Astrophysics Data System (ADS)

    Cao, Wei; Warrick, Erika R.; Neumark, Daniel M.; Leone, Stephen R.

    2016-01-01

    Using attosecond transient absorption, the dipole response of an argon atom in the vacuum ultraviolet (VUV) region is studied when an external electromagnetic field is present. An isolated attosecond VUV pulse populates Rydberg states lying 15 eV above the argon ground state. A synchronized few-cycle near infrared (NIR) pulse modifies the oscillating dipoles of argon impulsively, leading to alterations in the VUV absorption spectra. As the NIR pulse is delayed with respect to the VUV pulse, multiple features in the absorption profile emerge simultaneously including line broadening, sideband structure, sub-cycle fast modulations, and 5-10 fs slow modulations. These features indicate the coexistence of two general processes of the light-matter interaction: the energy shift of individual atomic levels and coherent population transfer between atomic eigenstates, revealing coherent superpositions. An intuitive formula is derived to treat both effects in a unifying framework, allowing one to identify and quantify the two processes in a single absorption spectrogram.

  16. Attosecond transient absorption of argon atoms in the vacuum ultraviolet region: line energy shifts versus coherent population transfer

    DOE PAGES

    Cao, Wei; Warrick, Erika R.; Neumark, Daniel M.; ...

    2016-01-18

    Using attosecond transient absorption, the dipole response of an argon atom in the vacuum ultraviolet (VUV) region is studied when an external electromagnetic field is present. An isolated attosecond VUV pulse populates Rydberg states lying 15 eV above the argon ground state. A synchronized few-cycle near infrared (NIR) pulse modifies the oscillating dipoles of argon impulsively, leading to alterations in the VUV absorption spectra. As the NIR pulse is delayed with respect to the VUV pulse, multiple features in the absorption profile emerge simultaneously including line broadening, sideband structure, sub-cycle fast modulations, and 5-10 fs slow modulations. These features indicatemore » the coexistence of two general processes of the light-matter interaction: the energy shift of individual atomic levels and coherent population transfer between atomic eigenstates, revealing coherent superpositions. Finally, an intuitive formula is derived to treat both effects in a unifying framework, allowing one to identify and quantify the two processes in a single absorption spectrogram.« less

  17. Compact Single-Layer Traveling-Wave Antenna DesignUsing Metamaterial Transmission Lines

    NASA Astrophysics Data System (ADS)

    Alibakhshikenari, Mohammad; Virdee, Bal Singh; Limiti, Ernesto

    2017-12-01

    This paper presents a single-layer traveling-wave antenna (TWA) that is based on composite right/left-handed (CRLH)-metamaterial (MTM) transmission line (TL) structure, which is implemented by using a combination of interdigital capacitors and dual-spiral inductive slots. By embedding dual-spiral inductive slots inside the CRLH MTM-TL results in a compact TWA. Dimensions of the proposed CRLH MTM-TL TWA is 21.5 × 30.0 mm2 or 0.372λ0 × 0.520λ0 at 5.2 GHz (center frequency). The fabricated TWA operates over 1.8-8.6 GHz with a fractional bandwidth greater than 120%, and it exhibits a peak gain and radiation efficiency of 4.2 dBi and 81%, respectively, at 5 GHz. By avoiding the use of lumped components, via-holes or defected ground structures, the proposed TWA design is economic for mass production as well as easy to integrate with wireless communication systems.

  18. Graded meshes in bio-thermal problems with transmission-line modeling method.

    PubMed

    Milan, Hugo F M; Carvalho, Carlos A T; Maia, Alex S C; Gebremedhin, Kifle G

    2014-10-01

    In this study, the transmission-line modeling (TLM) applied to bio-thermal problems was improved by incorporating several novel computational techniques, which include application of graded meshes which resulted in 9 times faster in computational time and uses only a fraction (16%) of the computational resources used by regular meshes in analyzing heat flow through heterogeneous media. Graded meshes, unlike regular meshes, allow heat sources to be modeled in all segments of the mesh. A new boundary condition that considers thermal properties and thus resulting in a more realistic modeling of complex problems is introduced. Also, a new way of calculating an error parameter is introduced. The calculated temperatures between nodes were compared against the results obtained from the literature and agreed within less than 1% difference. It is reasonable, therefore, to conclude that the improved TLM model described herein has great potential in heat transfer of biological systems. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Comment on "Dynamics and properties of waves in a modified Noguchi electrical transmission line"

    NASA Astrophysics Data System (ADS)

    Kenmogne, Fabien; Yemélé, David; Marquié, Patrick

    2016-09-01

    A recent paper [Phys. Rev. E 91, 022925 (2015), 10.1103/PhysRevE.91.022925] presents the derivation of the nonlinear equation modeling envelope waves in a specific case of band passed filter discrete nonlinear electrical transmission line (NLTL), called "A modified Noguchi electrical transmission line" according to the authors. Using the reductive perturbation approach in the semidiscrete approximation, they showed that the modulated waves propagating in this NLTL are described by the ordinary nonlinear Schrödinger (NLS) equation. On the basis of their results, the authors claimed that all previous works on the band passed filter NLTL, which considered the vanishing of the dc component of the signal voltage, are incorrect, and this dc term is nonzero. As a consequence, the dispersion and nonlinearity coefficients of the NLS equation are strongly different from those usually obtained, and they found, according to the sign of the product P Q , the existence of one more region (compared to the work of Marquié et al. [Phys. Rev. E 49, 828 (1994)], 10.1103/PhysRevE.49.828) in the dispersion curve that allows the motion of envelope solitons of higher frequency in the system. In this Comment we provide sufficient theoretical and numerical evidence showing that the evidence obtained by the authors otherwise is due to certain terms missed in their mathematical developments when they derived the NLS equation. Our results also suggest that the previous work of Marquié and co-workers correctly predict the fact that the dc term of the signal voltage does not exist and there exist only two regions in the dispersion curve according to the sign of the product P Q .

  20. Characterization of devices, circuits, and high-temperature superconductor transmission lines by electro-optic testing

    NASA Technical Reports Server (NTRS)

    Whitaker, John F.

    1991-01-01

    The development of a capability for testing transmission lines, devices, and circuits using the optically-based technique of electro-optics sampling was the goal of this project. Electro-optic network analysis of a high-speed device was demonstrated. The project involved research on all of the facets necessary in order to realize this result, including the discovery of the optimum electronic pulse source, development of an adequate test fixture, improvement of the electro-optic probe tip, and identification of a device which responded at high frequency but did not oscillate in the test fixture. In addition, during the process of investigating patterned high-critical-temperature superconductors, several non-contacting techniques for the determination of the transport properties of high T(sub c) films were developed and implemented. These are a transient, optical pump-probe, time-resolved reflectivity experiment, an impulsive-stimulated Raman scattering experiment, and a terahertz-beam coherent-spectroscopy experiment. The latter technique has enabled us to measure both the complex refractive index of an MgO substrate used for high-T(sub c) films and the complex conductivity of a YBa2Cu3O(7-x) sample. This information was acquired across an extremely wide frequency range: from the microwave to the submillimeter-wave regime. The experiments on the YBCO were conducted without patterning of, or contact to, the thin film. Thus, the need for the more difficult transmission-line experiments was eliminated. Progress in all of these areas was made and is documented in a number of papers. These papers may be found in the section listing the abstracts of the publications that were issued during the course of the research.

  1. Broadband reflectance coatings for vacuum ultraviolet application

    NASA Technical Reports Server (NTRS)

    Herzig, Howard; Fleetwood, C. M., Jr.; Flint, B. K.

    1987-01-01

    An experimental investigation has obtained results indicating that neither LaF3 nor LiYF4 are acceptable alternatives to MgF2 as coatings for vacuum-deposited aluminum mirrors from which high UV reflectance down to 1150 A is required. Nevertheless, LaF3 may prove useful in those specialized applications in which the suppression of lower wavelength emissions, such as the 1216-A hydrogen line, is desirable.

  2. Comparison of vacuum and non-vacuum urine tubes for urinary sediment analysis.

    PubMed

    Topcuoglu, Canan; Sezer, Sevilay; Kosem, Arzu; Ercan, Mujgan; Turhan, Turan

    2017-12-01

    Urine collection systems with aspiration system for vacuum tubes are becoming increasingly common for urinalysis, especially for microscopic examination of the urine. In this study, we aimed to examine whether vacuum aspiration of the urine sample has any adverse effect on sediment analysis by comparing results from vacuum and non-vacuum urine tubes. The study included totally 213 urine samples obtained from inpatients and outpatients in our hospital. Urine samples were collected to containers with aspiration system for vacuum tubes. Each sample was aliquoted to both vacuum and non-vacuum urine tubes. Urinary sediment analysis was performed using manual microscope. Results were evaluated using chi-square test. Comparison of the sediment analysis results from vacuum and non-vacuum urine tubes showed that results were highly concordant for erythrocyte, leukocyte and epithelial cells (gamma values 1, 0.997, and 0.994, respectively; p < .001). Results were also concordant for urinary casts, crystals and yeast (kappa values 0.815, 0.945 and 1, respectively; p < .001). The results show that in urinary sediment analysis, vacuum aspiration has no adverse effect on the cellular components except on casts.

  3. Characteristics of a four element gyromagnetic nonlinear transmission line array high power microwave source.

    PubMed

    Johnson, J M; Reale, D V; Krile, J T; Garcia, R S; Cravey, W H; Neuber, A A; Dickens, J C; Mankowski, J J

    2016-05-01

    In this paper, a solid-state four element array gyromagnetic nonlinear transmission line high power microwave system is presented as well as a detailed description of its subsystems and general output capabilities. This frequency agile S-band source is easily adjusted from 2-4 GHz by way of a DC driven biasing magnetic field and is capable of generating electric fields of 7.8 kV/m at 10 m correlating to 4.2 MW of RF power with pulse repetition frequencies up to 1 kHz. Beam steering of the array at angles of ±16.7° is also demonstrated, and the associated general radiation pattern is detailed.

  4. Characteristics of a four element gyromagnetic nonlinear transmission line array high power microwave source

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

    Johnson, J. M., E-mail: jared.johnson@ttu.edu; Reale, D. V.; Garcia, R. S.

    2016-05-15

    In this paper, a solid-state four element array gyromagnetic nonlinear transmission line high power microwave system is presented as well as a detailed description of its subsystems and general output capabilities. This frequency agile S-band source is easily adjusted from 2-4 GHz by way of a DC driven biasing magnetic field and is capable of generating electric fields of 7.8 kV/m at 10 m correlating to 4.2 MW of RF power with pulse repetition frequencies up to 1 kHz. Beam steering of the array at angles of ±16.7° is also demonstrated, and the associated general radiation pattern is detailed.

  5. Association between Exposure to Electromagnetic Fields from High Voltage Transmission Lines and Neurobehavioral Function in Children

    PubMed Central

    Huang, Jiongli; Tang, Tiantong; Hu, Guocheng; Zheng, Jing; Wang, Yuyu; Wang, Qiang; Su, Jing; Zou, Yunfeng; Peng, Xiaowu

    2013-01-01

    Background Evidence for a possible causal relationship between exposure to electromagnetic fields (EMF) emitted by high voltage transmission (HVT) lines and neurobehavioral dysfunction in children is insufficient. The present study aims to investigate the association between EMF exposure from HVT lines and neurobehavioral function in children. Methods Two primary schools were chosen based on monitoring data of ambient electromagnetic radiation. A cross-sectional study with 437 children (9 to 13 years old) was conducted. Exposure to EMF from HVT lines was monitored at each school. Information was collected on possible confounders and relevant exposure predictors using standardized questionnaires. Neurobehavioral function in children was evaluated using established computerized neurobehavioral tests. Data was analyzed using multivariable regression models adjusted for relevant confounders. Results After controlling for potential confounding factors, multivariable regression revealed that children attending a school near 500 kV HVT lines had poorer performance on the computerized neurobehavioral tests for Visual Retention and Pursuit Aiming compared to children attending a school that was not in close proximity to HVT lines. Conclusions The results suggest long-term low-level exposure to EMF from HVT lines might have a negative impact on neurobehavioral function in children. However, because of differences in results only for two of four tests achieved statistical significance and potential limitations, more studies are needed to explore the effects of exposure to extremely low frequency EMF on neurobehavioral function and development in children. PMID:23843999

  6. Apparatus and method for routing a transmission line through a downhole tool

    DOEpatents

    Hall, David R.; Hall, Jr., H. Tracy; Pixton, David S.; Briscoe, Michael; Reynolds, Jay

    2006-07-04

    A method for routing a transmission line through a tool joint having a primary and secondary shoulder, a central bore, and a longitudinal axis, includes drilling a straight channel, at a positive, nominal angle with respect to the longitudinal axis, through the tool joint from the secondary shoulder to a point proximate the inside wall of the centtral bore. The method further includes milling back, from within the central bore, a second channel to merge with the straight channel, thereby forming a continuous channel from the secondary shoulder to the central bore. In selected embodiments, drilling is accomplished by gun-drilling the straight channel. In other embodiments, the method includes tilting the tool joint before drilling to produce the positive, nominal angle. In selected embodiments, the positive, nominal angle is less than or equal to 15 degrees.

  7. Semi-flexible gas-insulated transmission line using sandwiched discs for intermittent flexing joints

    DOEpatents

    Kommineni, P.R.

    1983-02-15

    A gas-insulated transmission line includes an outer sheath, an inner conductor, an insulating gas electrically insulating the inner conductor from the outer sheath, and insulating supports insulatably supporting the inner conductor within the outer sheath. The inner conductor is provided with flexibility by the use of main conductor sections which are joined together through a conductor hub section and flexible flexing elements. Stress shields are provided to control the electric field at the locations of the conductor hub sections where the insulating supports are contacting the inner conductor. The flexing elements are formed by sandwiching together, by fusing, a pair of thin hollow discs which are fixedly secured to both the main conductor sections and the conductor hub section. 4 figs.

  8. A Versatile High-Vacuum Cryo-transfer System for Cryo-microscopy and Analytics

    PubMed Central

    Tacke, Sebastian; Krzyzanek, Vladislav; Nüsse, Harald; Wepf, Roger Albert; Klingauf, Jürgen; Reichelt, Rudolf

    2016-01-01

    Cryogenic microscopy methods have gained increasing popularity, as they offer an unaltered view on the architecture of biological specimens. As a prerequisite, samples must be handled under cryogenic conditions below their recrystallization temperature, and contamination during sample transfer and handling must be prevented. We present a high-vacuum cryo-transfer system that streamlines the entire handling of frozen-hydrated samples from the vitrification process to low temperature imaging for scanning transmission electron microscopy and transmission electron microscopy. A template for cryo-electron microscopy and multimodal cryo-imaging approaches with numerous sample transfer steps is presented. PMID:26910419

  9. IMPEDANCE MEASUREMENT OF VACUUM CHAMBER COMPONENTS FOR THE ADVANCE PHOTON SOURCE (APS) UPGRADE

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

    Sangroula, M.; Lindberg, R.; Lill, R.

    2017-06-16

    The proposed Advance Photon Source Upgrade (APS-U) employs a multi-bend achromat (MBA) lattice to increase the photon brightness by two to three orders of magnitude. One of the main design challenges of the upgrade is to minimize rf heating and collective instabilities associated with the impedance of small-aperture vacuum components. As part of this effort, my research focuses on impedance measurement and simulation of various MBA vacuum components. Here, we present the summary of the impedance contributions for the APS-U and describe our planned impedance measurement technique, including some measurement results for the non-evaporative getter (NEG)-coated copper chamber and simulationmore » results for other critical components using a novel Goubau line (G-line) set up.« less

  10. Impedance measurement of vacuum chamber components for the Advance Photon Source(APS) Upgrade

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

    Sangroula, M.; Lindberg, R.; Lill, R.

    2017-01-01

    The proposed Advance Photon Source Upgrade (APS-U) employs a multi-bend achromat (MBA) lattice to increase the photon brightness by two to three orders of magnitude. One of the main design challenges of the upgrade is to minimize rf heating and collective instabilities associated with the impedance of small-aperture vacuum components. As part of this effort, my research focuses on impedance measurement and simulation of various MBA vacuum components. Here, we present the summary of the impedance contributions for the APS-U and describe our planned impedance measurement technique, including some measurement results for the non-evaporative getter (NEG)-coated copper chamber and simulationmore » results for other critical components using a novel Goubau line (G-line) set up.« less

  11. An Annotated Bibliography of High-Voltage Direct-Current Transmission and Flexible AC Transmission (FACTS) Devices, 1991-1993.

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

    Litzenberger, Wayne; Lava, Val

    1994-08-01

    References are contained for HVDC systems, converter stations and components, overhead transmission lines, cable transmission, system design and operations, simulation of high voltage direct current systems, high-voltage direct current installations, and flexible AC transmission system (FACTS).

  12. Technical Trend of Environment-friendly High Voltage Vacuum Circuit Breaker (VCB)

    NASA Astrophysics Data System (ADS)

    Okubo, Hitoshi

    Vacuum Circuit Breakers (VCBs) have widely been used for low and medium voltage level, because of their high current interruption performance, maintenance free operations and environment-friendly characteristics. The VCB is now going to be applied to higher voltage systems for transmission and substation use. In this paper, the recent technical trend and future perspectives of high voltage VCBs are described, as well as their technical background.

  13. Effect of electron irradiation in vacuum on FEP-A silicon solar cell covers

    NASA Technical Reports Server (NTRS)

    Marsik, S. J.; Broder, J. D.

    1975-01-01

    Fluorinated ethylene-propylene-A (FEP-A) covers on silicon solar cells were irradiated with 1-MeV electrons, in vacuum, to an accumulated fluence equivalent to approximately 28 years in synchronous orbit. The effect of irradiation on the light transmittance of FEP-A was checked by measuring the short-circuit current of the cells after each dose increment. The results indicate no apparent overall loss in transmission due to irradiation of FEP-A. Filter wheel measurements revealed some darkening of the FEP-A at the blue end of the spectrum. Although no delamination from the cell surface was observed while in vacuum, embrittlement of FEP-A occurred at the accumulated dose.

  14. 49 CFR 570.56 - Vacuum brake assist unit and vacuum brake system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    .... The following requirements apply to vehicles with vacuum brake assist units and vacuum brake systems. (a) Vacuum brake assist unit integrity. The vacuum brake assist unit shall demonstrate integrity as... maintained on the pedal. (1) Inspection procedure. Stop the engine and apply service brake several times to...

  15. Demonstrations with a Vacuum: Old Demonstrations for New Vacuum Pumps.

    ERIC Educational Resources Information Center

    Greenslade, Thomas B., Jr.

    1989-01-01

    Explains mechanisms of 19th-century vacuum pumps. Describes demonstrations using the pump including guinea and feather tube, aurora tube, electric egg, Gassiots cascade, air mill, bell in vacuum, density and buoyancy of air, fountain in vacuum, mercury shower, palm and bladder glasses, Bacchus demonstration, pneumatic man-lifter, and Magdeburg…

  16. The Transmission Channel Tower Identification and Landslide Disaster Monitoring Based on Insar

    NASA Astrophysics Data System (ADS)

    Li, G.; Tan, Q.; Xie, C.; Fei, X.; Ma, X.; Zhao, B.; Ou, W.; Yang, Z.; Wang, J.; Fang, H.

    2018-04-01

    The transmission distance of transmission lines is long, the line affected by the diversity of climate and topography of the corridors of transmission lines, differences in regional geological structure conditions, variability of rock and soil types, and the complexity of groundwater. Under the influence of extreme weather conditions (ice-covered, strong wind, etc.) and sudden geological disasters (such as mudslides, flash floods, earthquakes, etc.), catastrophic damage and basic deformation problems of the tower foundations are prone, and even tower collapse accidents occur in severe cases, which affect the safe operation of transmission lines. Monitoring the deformation of power transmission towers and surrounding grounds, it is critical to ensuring the normal operation of transmission lines by assessing and controlling potential risks in advance. In this paper, using ALOS-2 PALSAR radar satellite data, differential interferometry was used to monitor surface deformation near the Sichuan Jinsu line transmission channel. The analysis found that a significant landslide hazard was found near the transmission channel tower in Yibin-Zhaotong section of Jinsu, Sichuan Province, the cumulative deformation reaches 9cm. The results of this paper can provide new monitoring means for safety monitoring of transmission towers.

  17. Credit PSR. This interior view shows the vacuum tumble dryer. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Credit PSR. This interior view shows the vacuum tumble dryer. The tumble dryer is lined with a water jacket to maintain temperature during the drying of ammonium perchlorate ("AP"); water enters and exits the dryer jacket through the pipe fittings along the horizontal center line of the dryer. The wall at the right is constructed to blow out in the event of an explosion - Jet Propulsion Laboratory Edwards Facility, Oxidizer Dryer Building, Edwards Air Force Base, Boron, Kern County, CA

  18. Improved Vacuum Bazooka

    NASA Astrophysics Data System (ADS)

    Cockman, John

    2003-04-01

    This apparatus is a modification to the well-known "vacuum bazooka" (PIRA 2B30.70). My vacuum bazooka is easy to construct and demonstrate, requires no precise fittings, foil, or vacuum grease, and propels ping-pong balls at a tremendous velocity!

  19. Sensor, method and system of monitoring transmission lines

    DOEpatents

    Syracuse, Steven J.; Clark, Roy; Halverson, Peter G.; Tesche, Frederick M.; Barlow, Charles V.

    2012-10-02

    An apparatus, method, and system for measuring the magnetic field produced by phase conductors in multi-phase power lines. The magnetic field measurements are used to determine the current load on the conductors. The magnetic fields are sensed by coils placed sufficiently proximate the lines to measure the voltage induced in the coils by the field without touching the lines. The x and y components of the magnetic fields are used to calculate the conductor sag, and then the sag data, along with the field strength data, can be used to calculate the current load on the line and the phase of the current. The sag calculations of this invention are independent of line voltage and line current measurements. The system applies a computerized fitter routine to measured and sampled voltages on the coils to accurately determine the values of parameters associated with the overhead phase conductors.

  20. Distribution of leakage currents in the cylindrical and conical sections of the magnetically insulated transmission line of the Angara-5-1 facility in experiments with wire arrays

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

    Grabovski, E. V.; Gribov, A. N.; Samokhin, A. A.

    2016-08-15

    Current leakages in the magnetically insulated transmission lines (MITL) impose restrictions on the transmission of electromagnetic pulses to the load in high-power electrophysical facilities. The multimodule Angara-5-1 facility with an output electric power of up to 6 TW is considered. In this work, the experimental and calculated profiles of leakage currents in two sections of the line are compared when the eight-module facility is loaded by a wire array. The azimuthal distribution of the current in the cylindrical section of the MITL is also considered.

  1. Effect of feeders in 3D modeling of low impedance multilayer CPW transmission line

    NASA Astrophysics Data System (ADS)

    Zaini, R. I.; Kyabaggu, P. B. K.; Sinulingga, E. P.

    2018-02-01

    Improved characteristics with low dissipation loss MMICs are highly desirable for wireless communications. However, the current industrial MMIC design is mainly based on microstrip concept which suffered from parasitic and unwanted phenomenon especially at higher frequency (>20 GHz). On the other hand, for future wireless technology, higher frequency operation is required and on-wafer microwave characterizations as well as precise modeling of 3D Multilayer CPW components are vital. This project concerns with understanding of the microwave characteristics behavior of Multilayer CPW components in MMIC applications. Feeder effect as unwanted parts in the characteristics has been investigated to determine its relation with the half wavelength resonance of the Multilayer CPW Low Impedance Transmission Line.

  2. Control of Postpartum Hemorrhage Using Vacuum-Induced Uterine Tamponade.

    PubMed

    Purwosunu, Yuditiya; Sarkoen, Widyastuti; Arulkumaran, Sabaratnam; Segnitz, Jan

    2016-07-01

    Postpartum hemorrhage is the leading cause of maternal mortality worldwide. Vacuum-induced uterine tamponade is a possible alternative approach to balloon tamponade systems for the treatment of postpartum hemorrhage resulting from atony. In a prospective proof-of-concept investigation of 10 women with vaginal deliveries in a hospital setting who failed first-line therapies for postpartum hemorrhage, tamponade was used. Vacuum-induced uterine tamponade was created through a device inserted transvaginally into the uterine cavity. An occlusion balloon built into the device shaft was inflated at the level of the external cervical os to create a uterine seal. Negative pressure was created by attaching a self-contained, mobile, electrically powered, pressure-regulated vacuum pump with a sterile graduated canister. In all 10 cases, the suction created an immediate seal at the cervical os, 50-250 mL of residual blood was evacuated from the uterine cavity, the uterus collapsed and regained tone within minutes, and hemorrhaging was controlled. The device remained in place for a minimum of 1 hour and up to 6.5 hours in one case while vaginal and perineal lacerations were easily repaired. This preliminary investigation suggests that a device designed to create vacuum-induced uterine tamponade may be a reasonable alternative to other devices used to treat atonic postpartum hemorrhage.

  3. Particle trap to sheath non-binding contact for a gas-insulated transmission line having a corrugated outer conductor

    DOEpatents

    Fischer, William H.

    1984-04-24

    A non-binding particle trap to outer sheath contact for use in gas insulated transmission lines having a corrugated outer conductor. The non-binding feature of the contact according to the teachings of the invention is accomplished by having a lever arm rotatably attached to a particle trap by a pivot support axis disposed parallel to the direction of travel of the inner conductor/insulator/particle trap assembly.

  4. 1.4 µm-Thick Transparent Radio Frequency Transmission Lines Based on Instant Fusion of Polyethylene Terephthalate Through Surface of Ag Nanowires

    NASA Astrophysics Data System (ADS)

    Kim, Sang-Woo; Kim, Kwang-Seok; Park, Myeongkoo; Nah, Wansoo; Kim, Dae Up; Lee, Cheul-Ro; Jung, Seung-Boo; Kim, Jong-Woong

    2018-05-01

    Though a percolated network of silver nanowires (AgNWs) has been considered the most promising flexible transparent electrode because of it high conductivity, high transmittance, and excellent flexibility, fabrication of AgNW-based transmission lines designed to conduct high frequency signals has been scarcely reported. The fabrication and performance of extremely thin (1.4 µm thick) and low lossy (smaller than - 17 dB for reflection coefficient corresponding to 2.5 GHz) transmission lines with unprecedented transparency (higher than 90% for the entire visible light spectrum) are demonstrated in this study. AgNWs deposited onto a 1.4 µm-thick polyethylene terephthalate (PET) sheet were irradiated by intense-pulsed-light to selectively raise their temperature. The intensive photon energy delivered to the AgNWs simultaneously caused the active diffusion of Ag atoms and plasmonic welding, resulting in large drops in resistivity without drastic changes in their physical shape or the optical transmittance of the films. Furthermore, absorption of heat also thermally activated the underlying polymer and causing it to react with the surface of the AgNWs—this results in enhanced adhesion between the AgNWs and the PET. Measurements and simulation of specially designed coplanar waveguide circuits revealed that the fabricated electrode could simultaneously provide excellent transmission characteristics and mechanical stability and transparency.

  5. Environmental Assessment for Central Power and Light Company`s proposed Military Highway-CFE tie 138/69-kV transmission line project Brownsville, Cameron County, Texas

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

    Not Available

    Central Power and Light Company (CPL) intends to upgrade its existing transmission line ties with the Commision Federal de Electricidad (CFE) system in Mexico. CPL currently has a single 69-kilovolt (kV) transmission line in the Brownsville area which connects CPL`s system with the system of CFE. This existing line runs between the Brownsville Switching Station, located on Laredo Road in Brownsville, Cameron County, Texas, and an existing CFE 69-kV line at the Rusteberg Bend of the Rio Grande in Cameron County. Under current conditions of need, the existing 69-kV line does not possess sufficient capability to engage in appropriate powermore » exchanges. Therefore, CPL is proposing to build a new line to link up with CFE. This proposed line would be a double-circuit line, which would (1) continue (on a slightly relocated route) the existing 69-kV tie from CPL`s Brownsville Switching Station to CFE`s facilities, and (2) add a 138-kV tie from the Military Highway Substation, located on Military Highway (US Highway 281), to CFE`s facilities. The proposed 138/69-kV line, which will be constructed and operated by CPL, will be built primarily on steel single-pole structures within an average 60-foot (ft) wide right-of-way (ROW). It will be approximately 6900--9200 ft (1.3--1.7 miles) in length, depending on the alternative route constructed.« less

  6. The Classical Vacuum.

    ERIC Educational Resources Information Center

    Boyer, Timothy H.

    1985-01-01

    The classical vacuum of physics is not empty, but contains a distinctive pattern of electromagnetic fields. Discovery of the vacuum, thermal spectrum, classical electron theory, zero-point spectrum, and effects of acceleration are discussed. Connection between thermal radiation and the classical vacuum reveals unexpected unity in the laws of…

  7. Electroweak vacuum instability and renormalized Higgs field vacuum fluctuations in the inflationary universe

    NASA Astrophysics Data System (ADS)

    Kohri, Kazunori; Matsui, Hiroki

    2017-08-01

    In this work, we investigated the electroweak vacuum instability during or after inflation. In the inflationary Universe, i.e., de Sitter space, the vacuum field fluctuations < δ phi 2 > enlarge in proportion to the Hubble scale H2. Therefore, the large inflationary vacuum fluctuations of the Higgs field < δ phi 2 > are potentially catastrophic to trigger the vacuum transition to the negative-energy Planck-scale vacuum state and cause an immediate collapse of the Universe. However, the vacuum field fluctuations < δ phi 2 >, i.e., the vacuum expectation values have an ultraviolet divergence, and therefore a renormalization is necessary to estimate the physical effects of the vacuum transition. Thus, in this paper, we revisit the electroweak vacuum instability from the perspective of quantum field theory (QFT) in curved space-time, and discuss the dynamical behavior of the homogeneous Higgs field phi determined by the effective potential V eff( phi ) in curved space-time and the renormalized vacuum fluctuations < δ phi 2 >ren via adiabatic regularization and point-splitting regularization. We simply suppose that the Higgs field only couples the gravity via the non-minimal Higgs-gravity coupling ξ(μ). In this scenario, the electroweak vacuum stability is inevitably threatened by the dynamical behavior of the homogeneous Higgs field phi, or the formations of AdS domains or bubbles unless the Hubble scale is small enough H< ΛI .

  8. The effect of external mean flow on sound transmission through double-walled cylindrical shells lined with poroelastic material

    NASA Astrophysics Data System (ADS)

    Zhou, Jie; Bhaskar, Atul; Zhang, Xin

    2014-03-01

    Sound transmission through a system of double shells, lined with poroelastic material in the presence of external mean flow, is studied. The porous material is modeled as an equivalent fluid because shear wave contributions are known to be insignificant. This is achieved by accounting for the energetically most dominant wave types in the calculations. The transmission characteristics of the sandwich construction are presented for different incidence angles and Mach numbers over a wide frequency range. It is noted that the transmission loss exhibits three dips on the frequency axis as opposed to flat panels where there are only two such frequencies—results are discussed in the light of these observations. Flow is shown to decrease the transmission loss below the ring frequency, but increase this above the ring frequency due to the negative stiffness and the damping effect added by the flow. In the absence of external mean flow, porous material provides superior insulation for most part of the frequency band of interest. However, in the presence of external flow, this is true only below the ring frequency—above this frequency, the presence of air gap in sandwich constructions is the dominant factor that determines the acoustic performance. In the absence of external flow, an air gap always improves sound insulation.

  9. Potential and field produced by a uniform or non-uniform elliptical beam inside a confocal elliptic vacuum chamber

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

    Regenstreif, E.

    The potential produced by an isolated beam of elliptic cross-section seems to have been considered first by L.C. Teng. Image effects of line charges in elliptic vacuum chambers were introduced into accelerator theory by L. J. Laslett. Various approximate solutions for elliptic beams of finite cross-section coasting inside an elliptic vacuum chamber were subsequently proposed by P. Lapostolle and C. Bovet. A rigorous expression is derived for the potential produced by an elliptic beam inside an elliptic vacuum chamber, provided the beam envelope and the vacuum chamber can be assimilated to confocal ellipses.

  10. APPARATUS FOR VACUUM DEPOSITION OF METALS

    DOEpatents

    Milleron, N.

    1962-03-13

    An apparatus and a method are described for continuous vacuum deposition of metals for metallic coatings, for ultra-high vacuum work, for purification of metals, for maintaining high-density electron currents, and for other uses. The apparatus comprises an externally cooled feeder tube extending into a container and adapted to feed metal wire or strip so that it emerges in a generally vertical position therein. The tube also provides shielding from the heat produced by an electron beam therein focused to impinge from a vertical direction upon the tip of the emerging wire. By proper control of the wire feed, coolant feed, and electron beam intensity, a molten ball of metal forms upon the emerging tip and remains self-supported thereon by the interaction of various forces. The metal is vaporized and travels in a line of sight direction, while additional wire is fed from the tube, so that the size of the molten ball remains constant. In the preferred embodiments, the wire is selected from a number of gettering metals and is degassed by electrical resistance in an adjacent chamber which is also partially evacuated. The wire is then fed through the feed tube into the electron beam and vaporizes and adsorbs gases to provide pumping action while being continuously deposited upon surfaces within the chamber. Ion pump electrodes may also be provided within line of sight of the vaporizing metal source to enhance the pumping action. (AEC)

  11. Germanium detector vacuum encapsulation

    NASA Technical Reports Server (NTRS)

    Madden, N. W.; Malone, D. F.; Pehl, R. H.; Cork, C. P.; Luke, P. N.; Landis, D. A.; Pollard, M. J.

    1991-01-01

    This paper describes an encapsulation technology that should significantly improve the viability of germanium gamma-ray detectors for a number of important applications. A specialized vacuum chamber has been constructed in which the detector and the encapsulating module are processed in high vacuum. Very high vacuum conductance is achieved within the valveless encapsulating module. The detector module is then sealed without breaking the chamber vacuum. The details of the vacuum chamber, valveless module, processing, and sealing method are presented.

  12. In-Containment Signal Conditioning and Transmission via Power Lines within High Dose Rate Areas of Nuclear Power Plants

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

    Mueller, Steffen; Weigel, Robert; Koelpin, Alexander

    2015-07-01

    Signal conditioning and transmission for sensor systems and networks within the containment of nuclear power plants (NPPs) still poses a challenge to engineers, particularly in the case of equipment upgrades for existing plants, temporary measurements, decommissioning of plants, but also for new builds. This paper presents an innovative method for efficient and cost-effective instrumentation within high dose rate areas inside the containment. A transmitter-receiver topology is proposed that allows simultaneous, unidirectional point-to-point transmission of multiple sensor signals by superimposing them on existing AC or DC power supply cables using power line communication (PLC) technology. Thereby the need for costly installationmore » of additional cables and containment penetrations is eliminated. Based on commercial off-the-shelf (COTS) electronic parts, a radiation hard transmitter is designed to operate in harsh environment within the containment during full plant operation. Hardware modularity of the transmitter allows application specific tradeoffs between redundancy and channel bandwidth. At receiver side in non-radiated areas, signals are extracted from the power line, demodulated, and provided either in analog or digital output format. Laboratory qualification tests and field test results within a boiling water reactor (BWR) are validating the proof of concept of the proposed system. (authors)« less

  13. Development of High Interruption Capability Vacuum Circuit Breaker -Technology of Vacuum Arc Control-

    NASA Astrophysics Data System (ADS)

    Niwa, Yoshimitsu; Kaneko, Eiji

    Vacuum circuit breakers (VCB) have been widely used for power distribution systems. Vacuum Interrupters, which are the current interruption unit, have been increased its interruption capability with the development of vacuum arc control technology by magnetic field. There are three major type electrodes: disk shaped electrodes, radial magnetic field electrodes, axial magnetic field (AMF) electrodes. In the disk shaped electrode, the vacuum arc between the electrodes is not controlled. In the AMF electrode, the vacuum arc is diffused and stabilized by an axial magnetic field, which is parallel to the arc current. In the last type of electrodes, the vacuum arc column is rotated by magnetic force generated by the current flowing in the electrodes. The interruption current and the voltage of one break VCB is increased to 100 kA, 144 kV respectively. This paper describes basic configurations and functions of VCB, vacuum arc control technology in vacuum interrupters, recent researches and applications of VCB.

  14. Electroweak vacuum instability and renormalized Higgs field vacuum fluctuations in the inflationary universe

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

    Kohri, Kazunori; Matsui, Hiroki, E-mail: kohri@post.kek.jp, E-mail: matshiro@post.kek.jp

    In this work, we investigated the electroweak vacuum instability during or after inflation. In the inflationary Universe, i.e., de Sitter space, the vacuum field fluctuations < δ φ {sup 2} > enlarge in proportion to the Hubble scale H {sup 2}. Therefore, the large inflationary vacuum fluctuations of the Higgs field < δ φ {sup 2} > are potentially catastrophic to trigger the vacuum transition to the negative-energy Planck-scale vacuum state and cause an immediate collapse of the Universe. However, the vacuum field fluctuations < δ φ {sup 2} >, i.e., the vacuum expectation values have an ultraviolet divergence, andmore » therefore a renormalization is necessary to estimate the physical effects of the vacuum transition. Thus, in this paper, we revisit the electroweak vacuum instability from the perspective of quantum field theory (QFT) in curved space-time, and discuss the dynamical behavior of the homogeneous Higgs field φ determined by the effective potential V {sub eff}( φ ) in curved space-time and the renormalized vacuum fluctuations < δ φ {sup 2} >{sub ren} via adiabatic regularization and point-splitting regularization. We simply suppose that the Higgs field only couples the gravity via the non-minimal Higgs-gravity coupling ξ(μ). In this scenario, the electroweak vacuum stability is inevitably threatened by the dynamical behavior of the homogeneous Higgs field φ, or the formations of AdS domains or bubbles unless the Hubble scale is small enough H < Λ {sub I} .« less

  15. Laboratory measurements of VUV N2 photoabsorption cross sections and line widths: applications to planetary atmospheric transmission models

    NASA Astrophysics Data System (ADS)

    Smith, P. L.; Stark, G.; Yoshino, K.

    2003-05-01

    The analyses of VUV occultation measurements of the N2-rich atmospheres of Titan and Triton are hampered by the lack of fundamental spectroscopic data for N2. There is a need for reliable photoabsorption cross sections and line widths for the 100 electronic bands of N2 in the 80 to 100 nm wavelength region. We present analyses of new measurements of individual line strengths and widths in N2 bands in the region 94 to 100 nm. Within individual bands, we find significant departures from the predicted line strength distributions based on isolated band models. Line width analyses within each band indicate that predissociation-broadening is often highly dependent on the rotational quantum number. We illustrate the importance of N2 line widths in the analysis of occultation measurements via N2 transmission models over selected wavelength regions. We have continued to compile on-line molecular spectroscopic atlas based on our N2 laboratory data: http://cfa-www.harvard.edu/amdata/ampdata/N2ARCHIVE/n2home.html. The archive includes published and unpublished 14N2, 14N15N, and 15N2 line lists and spectroscopic identifications, excited state energy levels, band and line f-values, a summary of published band f-value and line width measurements, and a cross-referenced summary of the relevant N2 literature. The listings are searchable by wavelength interval or band identification and are suitable for down-loading in a convenient format. We gratefully acknowledge funding support from NASA grant NAG5-9059 and the Smithsonian Institution Atherton-Seidell Grant Program.

  16. Vacuum ultraviolet molecular nitrogen photoabsorption cross sections for planetary atmospheric transmission models

    NASA Astrophysics Data System (ADS)

    Stark, G.; Smith, P. L.; Yoshino, K.; Rufus, J.; Huber, K. P.

    2001-11-01

    The analyses of VUV occultation measurements of the N2-rich atmospheres of Titan and Triton are hampered by the lack of fundamental spectroscopic data for N2. In particular, there is a need for reliable photoabsorption f-values and line widths for the ~ 100 electronic bands of N2 in the 80 to 100 nm wavelength region. As part of our continuing program of laboratory measurements and analyses of the N2 VUV absorption spectrum, we present the results of new measurements of individual line strengths and widths in selected bands. These results indicate that within a number of individual bands there are significant departures from the predicted line strength distributions based on isolated band models. New line width measurements in the 95 to 100 nm region are also presented and compared to other values found in the literature. We have continued to compile on-line molecular spectroscopic atlas based on our N2 laboratory data: http://cfa-www.harvard.edu/amdata/ampdata/N2ARCHIVE/n2home.html. The archive includes published and unpublished 14N2, 14N15N, and 15N2 line lists and spectroscopic identifications, excited state energy levels, band and line f-values, a summary of published band f-value and line width measurements, and a cross-referenced summary of the relevant N2 literature. The listings are searchable by wavelength interval or band identification and are suitable for down-loading in a convenient format. We gratefully acknowledge funding support from NASA grant NAG5-9059 and the Smithsonian Institution Atherton-Seidel grant program.

  17. Epidemiologic study of residential proximity to transmission lines and childhood cancer in California: description of design, epidemiologic methods and study population

    PubMed Central

    Kheifets, Leeka; Crespi, Catherine M; Hooper, Chris; Oksuzyan, Sona; Cockburn, Myles; Ly, Thomas; Mezei, Gabor

    2015-01-01

    We conducted a large epidemiologic case-control study in California to examine the association between childhood cancer risk and distance from the home address at birth to the nearest high-voltage overhead transmission line as a replication of the study of Draper et al. in the United Kingdom. We present a detailed description of the study design, methods of case ascertainment, control selection, exposure assessment and data analysis plan. A total of 5788 childhood leukemia cases and 3308 childhood central nervous system cancer cases (included for comparison) and matched controls were available for analysis. Birth and diagnosis addresses of cases and birth addresses of controls were geocoded. Distance from the home to nearby overhead transmission lines was ascertained on the basis of the electric power companies’ geographic information system (GIS) databases, additional Google Earth aerial evaluation and site visits to selected residences. We evaluated distances to power lines up to 2000 m and included consideration of lower voltages (60–69 kV). Distance measures based on GIS and Google Earth evaluation showed close agreement (Pearson correlation >0.99). Our three-tiered approach to exposure assessment allowed us to achieve high specificity, which is crucial for studies of rare diseases with low exposure prevalence. PMID:24045429

  18. A Fiber Bragg Grating-Based Dynamic Tension Detection System for Overhead Transmission Line Galloping.

    PubMed

    Ma, Guo-Ming; Li, Ya-Bo; Mao, Nai-Qiang; Shi, Cheng; Zhang, Bo; Li, Cheng-Rong

    2018-01-26

    Galloping of overhead transmission lines (OHTLs) may induce conductor breakage and tower collapse, and there is no effective method for long distance distribution on-line galloping monitoring. To overcome the drawbacks of the conventional galloping monitoring systems, such as sensitivity to electromagnetic interference, the need for onsite power, and short lifetimes, a novel optical remote passive measuring system is proposed in the paper. Firstly, to solve the hysteresis and eccentric load problem in tension sensing, and to extent the dynamic response range, an 'S' type elastic element structure with flanges was proposed. Then, a tension experiment was carried out to demonstrate the dynamic response characteristics. Moreover, the designed tension sensor was stretched continuously for 30 min to observe its long time stability. Last but not the least, the sensor was mounted on a 70 m conductor model, and the conductor was oscillated at different frequencies to investigate the dynamic performance of the sensor. The experimental results demonstrate the sensor is suitable for the OHTL galloping detection. Compared with the conventional sensors for OHTL monitoring, the system has many advantages, such as easy installation, no flashover risk, distribution monitoring, better bandwidth, improved accuracy and higher reliability.

  19. Rocket Spectroheliograph for the Mg II Line at 2802.7 A.

    PubMed

    Fredga, K

    1969-02-01

    A rocket-borne spectroheliograph designed to take monochromatic pictures of the sun in the Mg II line at 2802.7 A is described in detail. The photographic system consists of a Questar telescope, a Solc type birefringent filter, and an automatic Robot camera. The double Solc filter has a spectral bandwidth of 3.5 A. The two units in the double filter have been thoroughly tested and are compared with theoretically calculated transmission curves. Two new types of linear film polarizers for the uv region have been tested and used in the filter. A temperature control unit was developed which stabilized the filter temperature in flight to within +/-0.2 degrees C. The instrument has been tested in vacuum and to the Aerobee 150 vibration specifications. It has been flown and successfully recovered three times and performed excellently during each fight.

  20. Design of a Wireless Sensor Module for Monitoring Conductor Galloping of Transmission Lines.

    PubMed

    Huang, Xinbo; Zhao, Long; Chen, Guimin

    2016-10-09

    Conductor galloping may cause flashovers and even tower collapses. The available conductor galloping monitoring methods often employ acceleration sensors to measure the conductor translations without considering the conductor twist. In this paper, a new sensor for monitoring conductor galloping of transmission lines based on an inertial measurement unit and wireless communication is proposed. An inertial measurement unit is used for collecting the accelerations and angular rates of a conductor, which are further transformed into the corresponding geographic coordinate frame using a quaternion transformation to reconstruct the galloping of the conductor. Both the hardware design and the software design are described in details. The corresponding test platforms are established, and the experiments show the feasibility and accuracy of the proposed monitoring sensor. The field operation of the proposed sensor in a conductor spanning 734 m also shows its effectiveness.