WorldWideScience

Sample records for ground pronone power

  1. Power Gating Based Ground Bounce Noise Reduction

    Directory of Open Access Journals (Sweden)

    M. Uma Maheswari

    2014-08-01

    Full Text Available As low power circuits are most popular the decrease in supply voltage leads to increase in leakage power with respect to the technology scaling. So for removing this kind of leakages and to provide a better power efficiency many power gating techniques are used. But the leakage due to ground connection to the active part of the circuit is very high rather than all other leakages. As it is mainly due to the back EMF of the ground connection it was called it as ground bounce noise. To reduce this noise different methodologies are designed. In this paper the design of such an efficient technique related to ground bounce noise reduction using power gating circuits and comparing the results using DSCH and Microwind low power tools. In this paper the analysis of adders such as full adders using different types of power gated circuits using low power VLSI design techniques and to present the comparison results between different power gating methods.

  2. Modeling and Simulation of an Unmanned Ground Vehicle Power System

    Science.gov (United States)

    2014-03-28

    Wilhelm, A. N., Surgenor, B. W., and Pharoah, J. G., “Design and evaluation of a micro-fuel-cell-based power system for a mobile robot ,” Mechatronics ...of Michigan, Ann Arbor, MI, USA bU.S. Army RDECOM-TARDEC, Warren, MI, USA ABSTRACT Long-duration missions challenge ground robot systems with respect...to energy storage and efficient conversion to power on demand. Ground robot systems can contain multiple power sources such as fuel cell, battery and

  3. Power productivity of the ground surface

    Directory of Open Access Journals (Sweden)

    Gutu A.I.

    2008-12-01

    Full Text Available Here there is presented an attempt to estimate the efficiency degree when working with soil surface through the different methods of valorization incident solar radiation. Such technical methods are being analyzed as (solar collectors, photovoltaic cells, solar thermal power plants, power cultures field (bushes, wheat, sunflower, maize, rape, sorghum as well as microalgae crops. Here is the description of advantages and disadvantages for each group in part out of these three. The technical methods are up to date from the efficiency utilization view-point of industrial area. Microalgae crops are similar to technical methods from this point of view.

  4. Power quality considerations for nuclear spectroscopy applications: Grounding

    Energy Technology Data Exchange (ETDEWEB)

    García-Hernández, J.M., E-mail: josemanuel.garcia@inin.gob.mx [Instituto Nacional de Investigaciones Nucleares, ININ, Carretera México-Toluca S/N, La Marquesa, Ocoyoacac, 52750 Estado de México, México (Mexico); Instituto Tecnológico de Toluca, Departamento de Estudios de Posgrado e Investigación, Av. Tecnológico S/N, ExRancho La Virgen, 52140 Metepec, México (Mexico); Ramírez-Jiménez, F.J., E-mail: fjr@ieee.org [Instituto Nacional de Investigaciones Nucleares, ININ, Carretera México-Toluca S/N, La Marquesa, Ocoyoacac, 52750 Estado de México, México (Mexico); Instituto Tecnológico de Toluca, Departamento de Estudios de Posgrado e Investigación, Av. Tecnológico S/N, ExRancho La Virgen, 52140 Metepec, México (Mexico); Mondragón-Contreras, L.; López-Callejas, R. [Instituto Nacional de Investigaciones Nucleares, ININ, Carretera México-Toluca S/N, La Marquesa, Ocoyoacac, 52750 Estado de México, México (Mexico); Instituto Tecnológico de Toluca, Departamento de Estudios de Posgrado e Investigación, Av. Tecnológico S/N, ExRancho La Virgen, 52140 Metepec, México (Mexico); Torres-Bribiesca, M.A. [Instituto Nacional de Investigaciones Nucleares, ININ, Carretera México-Toluca S/N, La Marquesa, Ocoyoacac, 52750 Estado de México, México (Mexico); and others

    2013-11-21

    Traditionally the electrical installations are designed for supplying power and to assure the personnel safety. In nuclear analysis laboratories, additional issues about grounding also must be considered for proper operation of high resolution nuclear spectroscopy systems. This paper shows the traditional ways of grounding nuclear spectroscopy systems and through different scenarios, it shows the effects on the more sensitive parameter of these systems: the energy resolution, it also proposes the constant monitoring of a power quality parameter as a way to preserve or to improve the resolution of the systems, avoiding the influence of excessive extrinsic noise. -- Highlights: •We analyze the performance of nuclear spectroscopy systems with different configurations of the grounding system. •The neutral to ground voltage is an indicator of the ground conditions, a high value may contribute to the increase of the FWHM in nuclear spectroscopy systems. •The use of an isolated ground system is the best option to preserve the best FWHM value. •The application of power quality concepts can help to guaranty the best configuration of the grounding system.

  5. Impact of grounding and filtering on power insulation monitoring in insulated terrestrial power networks

    NARCIS (Netherlands)

    van Vugt, Pieter Karel Anton; Bijman, Rob; Timens, R.B.; Leferink, Frank Bernardus Johannes

    2013-01-01

    Insulated terrestrial power networks are used for reliable systems such as large production plants, hospital operating rooms and naval ships. The system is isolated from ground and a first fault, such as a short circuit between a phase and ground, will not result in disconnection of the power via

  6. Spatial Power Combining Amplifier for Ground and Flight Applications

    Science.gov (United States)

    Velazco, J. E.; Taylor, M.

    2016-11-01

    Vacuum-tube amplifiers such as klystrons and traveling-wave tubes are the workhorses of high-power microwave radiation generation. At JPL, vacuum tubes are extensively used in ground and flight missions for radar and communications. Vacuum tubes use electron beams as the source of energy to achieve microwave power amplification. Such electron beams operate at high kinetic energies and thus require high voltages to function. In addition, vacuum tubes use compact cavity and waveguide structures that hold very intense radio frequency (RF) fields inside. As the operational frequency is increased, the dimensions of these RF structures become increasingly smaller. As power levels and operational frequencies are increased, the highly intense RF fields inside of the tubes' structures tend to arc and create RF breakdown. In the case of very high-power klystrons, electron interception - also known as body current - can produce thermal runaway of the cavities that could lead to the destruction of the tube. The high voltages needed to power vacuum tubes tend to require complicated and cumbersome power supplies. Consequently, although vacuum tubes provide unmatched high-power microwaves, they tend to arc, suffer from thermal issues, and require failure-prone high-voltage power supplies. In this article, we present a new concept for generating high-power microwaves that we refer to as the Spatial Power Combining Amplifier (SPCA). The SPCA is very compact, requires simpler, lower-voltage power supplies, and uses a unique power-combining scheme wherein power from solid-state amplifiers is coherently combined. It is a two-port amplifier and can be used inline as any conventional two-port amplifier. It can deliver its output power to a coaxial line, a waveguide, a feed, or to any microwave load. A key feature of this new scheme is the use of higher-order-mode microwave structures to spatially divide and combine power. Such higher-order-mode structures have considerably larger cross

  7. Orbit-to-ground Wireless Power Transfer test mission

    Science.gov (United States)

    Bergsrud, C.; Noghanian, S.; Straub, J.; Whalen, D.; Fevig, R.

    Since the 1970s the concept of transferring power from orbit for use on Earth has had a great deal of consideration for future energy and environmental sustainability here on Earth. The cost, size and complexity of a production-grade system are extremely large, and have many environmental considerations. There has never been a publicly disclosed orbit-to-ground power transfer test mission. A proposed project provides an opportunity to test the conceptual operation of such a system, albeit at a much lower power level than the `grand' or `real scale' system. During this test, a small Solar Powered (SP) 6-U CubSat will be deployed into Low-Earth Orbit (LEO) (225 or 325 km) to collect and store 1 KW of power from solar energy as the satellite is orbiting. The goal is to transmit 1 KW of wireless power at a microwave frequency of 5.8 or 10 GHz to a ground antenna array system. This paper presents the architecture for the proposed mission and discusses the regulatory, legal, and environmental issues that such a mission poses. Furthermore, the gain of the transmitter is analyzed at 20 and 30 dB as well as the gain of the receiver is analyzed at 30, 40, and 50 dB. A SP 6-U CubeSat will have a Lithium Ion (LIon) battery capable of storing enough energy for 83.33 Whr charge to run the satellites controls, and 1 KW necessary for a 5-minute demonstration and test (in addition to power required for its own operational requirements). Once charged, the satellite will use highly accurate position and attitude knowledge provided by an onboard star-tracker, Global Positioning Satellite (GPS) and inertial measurement unit to determine the proper orientation for the power transfer test. The onboard Attitude Determination and Control (ADCS) will be utilized to achieve and maintain this orientation during the test period. A cold-gas propulsion system will be available to de-spin the reaction wheels to ensure that sufficient ADCS capabilities exist for attitude-stabilization use during

  8. Ground state energies from converging and diverging power series expansions

    Science.gov (United States)

    Lisowski, C.; Norris, S.; Pelphrey, R.; Stefanovich, E.; Su, Q.; Grobe, R.

    2016-10-01

    It is often assumed that bound states of quantum mechanical systems are intrinsically non-perturbative in nature and therefore any power series expansion methods should be inapplicable to predict the energies for attractive potentials. However, if the spatial domain of the Schrödinger Hamiltonian for attractive one-dimensional potentials is confined to a finite length L, the usual Rayleigh-Schrödinger perturbation theory can converge rapidly and is perfectly accurate in the weak-binding region where the ground state's spatial extension is comparable to L. Once the binding strength is so strong that the ground state's extension is less than L, the power expansion becomes divergent, consistent with the expectation that bound states are non-perturbative. However, we propose a new truncated Borel-like summation technique that can recover the bound state energy from the diverging sum. We also show that perturbation theory becomes divergent in the vicinity of an avoided-level crossing. Here the same numerical summation technique can be applied to reproduce the energies from the diverging perturbative sums.

  9. Battery-free power for unattended ground sensors

    Science.gov (United States)

    Moldt, Vera A.

    2003-09-01

    In our current military environment, many operations are fought with small, highly mobile reconnaissance and strike forces that must move in and out of hostile terrain, setting up temporary bases and perimeters. As such, today's warfighter has to be well equipped to insure independent operation and survival of small, deployed groups. The use of unattended ground sensors in reconfigurable sensor networks can provide portable perimeter security for such special operations. Since all of the equipment for the missions must be carried by the warfighter, weight is a critical issue. Currently, batteries constitute much of that weight, as batteries are short-lived and unreliable. An alternative power source is required to eliminate the need for carrying multiple replacement batteries to support special operations. Such a battery-free, replenishable, energy management technology has been developed by Ambient Control Systems. Ambient has developed an advanced mid-door photovoltaic technology, which converts light to energy over a wide range of lighting conditions. The energy is then stored in supercapacitors, a highly robust, long-term storage medium. Ambient's advanced energy management technology will power remote sensor and control systems 24 hours/day, 7 days/week for over 20 years, without batteries, providing for ongoing detection, surveillance and other remote operations.

  10. Measurement of Required Power with Human-Powered Aircraft in Take-off Ground Running

    Science.gov (United States)

    Yoshikawa, Toshiaki; Sakamoto, Shinsuke; Hori, Kotono; Kusumoto, Hiroshi; Yamamoto, Yasushi; Hattori, Takashi; Sata, Kouta

    In this paper, we propose the method for the measurement of required power and the adjustment of optimum gear ratio in take-off ground running. To get the values of required power and speed, we measured torque of the left side and the right side of pedals, RPM of pedals, and speed of the cockpit frame. In order to improve the take-off speed, some drums were applied, and the optimum gear ratio of the front drum to the rear drum was determined.

  11. System design specification Brayton Isotope Power System (BIPS) Flight System (FS), and Ground Demonstration System (GDS)

    Energy Technology Data Exchange (ETDEWEB)

    1976-06-14

    The system design specification for ground demonstration, development, and flight qualification of a Brayton Isotope Power System (BIPS) is presented. The requirements for both a BIPS conceptual Flight System (FS) and a Ground Demonstration System (GDS) are defined.

  12. 30 CFR 75.700 - Grounding metallic sheaths, armors, and conduits enclosing power conductors.

    Science.gov (United States)

    2010-07-01

    ... conduits enclosing power conductors. 75.700 Section 75.700 Mineral Resources MINE SAFETY AND HEALTH... Grounding § 75.700 Grounding metallic sheaths, armors, and conduits enclosing power conductors. All metallic sheaths, armors, and conduits enclosing power conductors shall be electrically continuous throughout...

  13. Models of ionospheric VLF absorption of powerful ground based transmitters

    Science.gov (United States)

    Cohen, M. B.; Lehtinen, N. G.; Inan, U. S.

    2012-12-01

    Ground based Very Low Frequency (VLF, 3-30 kHz) radio transmitters play a role in precipitation of energetic Van Allen electrons. Initial analyses of the contribution of VLF transmitters to radiation belt losses were based on early models of trans-ionospheric propagation known as the Helliwell absorption curves, but some recent studies have found that the model overestimates (by 20-100 dB) the VLF energy reaching the magnetosphere. It was subsequently suggested that conversion of wave energy into electrostatic modes may be responsible for the error. We utilize a newly available extensive record of VLF transmitter energy reaching the magnetosphere, taken from the DEMETER satellite, and perform a direct comparison with a sophisticated full wave model of trans-ionospheric propagation. Although the model does not include the effect of ionospheric irregularities, it correctly predicts the average total power injected into the magnetosphere within several dB. The results, particularly at nighttime, appear to be robust against the variability of the ionospheric electron density. We conclude that the global effect of irregularity scattering on whistler mode conversion to quasi-electrostatic may be no larger than 6 dB.

  14. Strong ground movement induced by mining activities and its effect on power transmission structures

    Institute of Scientific and Technical Information of China (English)

    DAI Kao-shan; CHEN Shen-en

    2009-01-01

    Surface mining activities may introduce damages to nearby infrastructure. Concerns are put forward by the power company about structural integrity of electric power transmission structures in areas where coal mining activities cause strong ground vibrations. Common practice in the power industry is to limit ground motion by specifying maximum Peak Particle Velocity. So far, there is a lack of industry-wide recognized guidelines on how ground vibration limits should be set for the transmission structures. In order to develop a defense strategy to protect power transmission lines against strong ground motions in mining areas, a systematic research work was conducted to establish strong ground vibration characteristics and to study impacts of ground excitations on transmission pole structures. Ground movements were recorded using geophones and wireless tri-axial sensing units. The process of generating ground motion response spectra via analyzing actual ground motion measurements is described in the paper. These spectra developed based on peak particle velocities were used as a basis for spectral analysis performed using validated Finite Element models to obtain structural displacements, reactions and stress states of the transmission pole structures in the mining sites. A quantitative ground motion limit was established by comparing structural responses with the corresponding design requirements.

  15. 30 CFR 77.700 - Grounding metallic sheaths, armors, and conduits enclosing power conductors.

    Science.gov (United States)

    2010-07-01

    ... conduits enclosing power conductors. 77.700 Section 77.700 Mineral Resources MINE SAFETY AND HEALTH..., and conduits enclosing power conductors. Metallic sheaths, armors, and conduits enclosing power conductors shall be electrically continuous throughout and shall be grounded by methods approved by...

  16. Advantages of ground-to-space laser power beaming

    Science.gov (United States)

    Rather, John D. G.

    1992-01-01

    NASA's current research activities to evaluate laser power beaming systems are reviewed. Applications of such systems are considered, including communications satellites, radar and direct broadcast satellites, space transfer vehicles lunar base operations and exploration, and optical technologies. The current laser power beaming program within the NASA Headquarters Office of Aeronautics and Space Technology is addressed.

  17. Feature Extraction Method for High Impedance Ground Fault Localization in Radial Power Distribution Networks

    DEFF Research Database (Denmark)

    Jensen, Kåre Jean; Munk, Steen M.; Sørensen, John Aasted

    1998-01-01

    processes and communication systems lead to demands for improved monitoring of power distribution networks so that the quality of power delivery can be kept at a controlled level. The ground fault localization method for each feeder in a network is based on the centralized frequency broadband measurement...... of three phase voltages and currents. The method consists of a feature extractor, based on a grid description of the feeder by impulse responses, and a neural network for ground fault localization. The emphasis of this paper is the feature extractor, and the detection of the time instance of a ground fault...

  18. Comparing the Efficacy of Airpower and Heavy Ground Power

    Science.gov (United States)

    2011-12-01

    conflicts have weakened American power on the global stage over the last decade. Second, the lethality of modern weapons, as first seen during the Arab...airpower typically places top targeting priority on air defense systems during the opening stages of air operations. Therefore, most of an...would smash “the material and moral resources of a people caught up in a frightful cataclysm which haunts them everywhere without cease until the final

  19. Synchronous Study of Ferroresonance and Inrush Current Phenomena and their Related Reasons in Ground Power Networks

    Science.gov (United States)

    Akrami, Amin; Ghaderi, Mohammad; Ghadi, Saeed

    2010-01-01

    Energizing the power transformers usually results in flowing very high inrush currents. This harmful current can be minimized using controlled switching and considering the value of residual flux. But nowadays, developing the ground power networks results in high increment of ferroresonance phenomenon occurrence due to the line' capacitance reactance and nonlinear inductive reactance of power transformer's core. In this study, these transient phenomena and their cause have studied synchronously.

  20. Low Power Ground-Based Laser Illumination for Electric Propulsion Applications

    Science.gov (United States)

    Lapointe, Michael R.; Oleson, Steven R.

    1994-01-01

    A preliminary evaluation of low power, ground-based laser powered electric propulsion systems is presented. A review of available and near-term laser, photovoltaic, and adaptive optic systems indicates that approximately 5-kW of ground-based laser power can be delivered at an equivalent one-sun intensity to an orbit of approximately 2000 km. Laser illumination at the proper wavelength can double photovoltaic array conversion efficiencies compared to efficiencies obtained with solar illumination at the same intensity, allowing a reduction in array mass. The reduced array mass allows extra propellant to be carried with no penalty in total spacecraft mass. The extra propellant mass can extend the satellite life in orbit, allowing additional revenue to be generated. A trade study using realistic cost estimates and conservative ground station viewing capability was performed to estimate the number of communication satellites which must be illuminated to make a proliferated system of laser ground stations economically attractive. The required number of satellites is typically below that of proposed communication satellite constellations, indicating that low power ground-based laser beaming may be commercially viable. However, near-term advances in low specific mass solar arrays and high energy density batteries for LEO applications would render the ground-based laser system impracticable.

  1. The Integrated Solar Upper Stage engine ground demonstration power management and distribution subsystem design

    Science.gov (United States)

    Baez, Anastacio N.; Kimnach, Greg L.

    1997-01-01

    The National Aeronautics and Space Administration (NASA), the Air Force Phillips Laboratory (PL), and the Defense Special Weapons Agency (DSWA) in a joint effort are developing technologies for a solar bimodal system. A solar bimodal system combines thermal propulsion and electric power generation in a single integrated system. A spacecraft Integrated Solar Upper Stage (ISUS) bimodal system combines orbital transfer propulsion, electric power generation, and on-board propulsion into one overall system. A key benefit of such integrated system is the augmentation of payload to spacecraft mass ratio thus resulting in lower launch vehicle requirements. Scaling down to smaller launch vehicles increases space access by reducing overall mission cost. The NASA/PL/DSWA ISUS program is concentrating efforts on a near-term ground test demonstration of the bimodal concept. A successful ground demonstration of the ISUS various technologies will enable a full system flight demonstration of the bimodal concept. NASA Lewis Research Center in Cleveland Ohio will be the site for the engine ground demonstrator (EGD). The ISUS bimodal system uses solar concentrators to focus solar energy into an integrated receiver, absorber, and converter (RAC) power plant. The power plant main body is a graphite blackbody that stores thermal energy within a cavity in its main core. During the propulsion phase of the bimodal system a propellant flows into the graphite main core and is distributed uniformly through axial flow channels in the heated cavity. The blackbody core heats the propellant that is then discharged into an output tube thus creating thrust. An array of thermionic generators encircles the graphite core cavity and provides electrical energy conversion functions during the power generation phase. The power management and distribution subsystem's main functions are to condition raw electrical power generated by the RAC power plant and deliver it to the spacecraft payloads. This paper

  2. Study on Site Specific Design Earthquake Ground Motion of Nuclear Power Plants in China1

    Institute of Scientific and Technical Information of China (English)

    Zhou Bochang; Li Xiaojun; Li Yaqi

    2008-01-01

    The main technical backgrounds and requirements are introduced with regard to earthquake ground motion design parameters in several domestic and American standards,codes and guides involved in the seismic analysis and design activities of nuclear power plants in China.Based on the research results from site seismic safety evaluation of domestic nuclear power plant projects in the last years,characteristics and differences of site specific design spectra are analyzed in comparison with standard response spectra,and the suitability of standard response spectra for domestic nuclear power plant projects is discussed.

  3. Direct power generation from waste coffee grounds in a biomass fuel cell

    Science.gov (United States)

    Jang, Hansaem; Ocon, Joey D.; Lee, Seunghwa; Lee, Jae Kwang; Lee, Jaeyoung

    2015-11-01

    We demonstrate the possibility of direct power generation from waste coffee grounds (WCG) via high-temperature carbon fuel cell technology. At 900 °C, the WCG-powered fuel cell exhibits a maximum power density that is twice than carbon black. Our results suggest that the heteroatoms and hydrogen contained in WCG are crucial in providing good cell performance due to its in-situ gasification, without any need for pre-reforming. As a first report on the use of coffee as a carbon-neutral fuel, this study shows the potential of waste biomass (e.g. WCG) in sustainable electricity generation in fuel cells.

  4. Auditory Power-Law Activation Avalanches Exhibit a Fundamental Computational Ground State

    Science.gov (United States)

    Stoop, Ruedi; Gomez, Florian

    2016-07-01

    The cochlea provides a biological information-processing paradigm that we are only beginning to understand in its full complexity. Our work reveals an interacting network of strongly nonlinear dynamical nodes, on which even a simple sound input triggers subnetworks of activated elements that follow power-law size statistics ("avalanches"). From dynamical systems theory, power-law size distributions relate to a fundamental ground state of biological information processing. Learning destroys these power laws. These results strongly modify the models of mammalian sound processing and provide a novel methodological perspective for understanding how the brain processes information.

  5. Analysis of overvoltages in overhead ground wires of extra high voltage (EHV) power transmission line under single-phase-to-ground faults

    NARCIS (Netherlands)

    Dudurych, [No Value; Rosolowski, E

    2000-01-01

    Overhead ground wires (GW) of extra high voltage (EHV) power transmission lines, apart from lightning-induced overvoltage protection are frequently used for carrier-current communication. In this case the ground wires are suspended on insulators, the dielectric strength of which should be sufficient

  6. Ground state atomic oxygen in high-power impulse magnetron sputtering: a quantitative study

    Science.gov (United States)

    Britun, Nikolay; Belosludtsev, Alexandr; Silva, Tiago; Snyders, Rony

    2017-02-01

    The ground state density of oxygen atoms in reactive high-power impulse magnetron sputtering discharges has been studied quantitatively. Both time-resolved and space-resolved measurements were conducted. The measurements were performed using two-photon absorption laser-induced fluorescence (TALIF), and calibrated by optical emission actinometry with multiple Ar emission lines. The results clarify the dynamics of the O ground state atoms in the discharge afterglow significantly, including their propagation and fast decay after the plasma pulse, as well as the influence of gas pressure, O2 admixture, etc.

  7. Analysis of test results of a ground demonstration of a Pluto/Express power generator

    Energy Technology Data Exchange (ETDEWEB)

    Tournier, J.-M.; El-Genk, M.S. [University of New Mexico, Dept. of Chemical and Nuclear Engineering, Albuquerque, NM (United States)

    1999-07-01

    Results of recent tests of a Pluto/Express electric power generator ground demonstration were analysed. The performance parameters of each of the eight ground demonstrations vapour anode, multitube alkali-metal thermal-to-electric conversion (AMTEC) cells, designated PX-3G, were analysed and compared. The ground demonstration cells produced a total peak electric power of 27 W{sub e} at a load voltage of 16 V when tested at hot and cold side temperatures of 1123 K and 553 K, respectively. The electric power output and terminal voltage of the individual cells, however, differed by as much as 25%, from 2.94 to 3.76 W{sub e}, and from 1.73 to 2.21 V, respectively. These variations were attributed to differences among the cells in the values of: (a) the contact resistance of the BASE/electrode and of the electrode/current collector; (b) the leakage current between the anode and cathode electrodes through the metal-ceramic braze joint between the BASE tubes and the metal support plate; and (c) the charge-exchange polarisation losses. Analysis of results suggested the existence of large electrical leakage currents in some of the PX-3G cells. The performance of the PX-3G cells was below that needed for meeting the Pluto/Express mission's electric power requirement. (Author)

  8. Ground heat flux and power sources of low-enthalpy geothermal systems

    Science.gov (United States)

    Bayer, Peter; Blum, Philipp; Rivera, Jaime A.

    2015-04-01

    Geothermal heat pumps commonly extract energy from the shallow ground at depths as low as approximately 400 m. Vertical borehole heat exchangers are often applied, which are seasonally operated for decades. During this lifetime, thermal anomalies are induced in the ground and surface-near aquifers, which often grow over the years and which alleviate the overall performance of the geothermal system. As basis for prediction and control of the evolving energy imbalance in the ground, focus is typically set on the ground temperatures. This is reflected in regulative temperature thresholds, and in temperature trends, which serve as indicators for renewability and sustainability. In our work, we examine the fundamental heat flux and power sources, as well as their temporal and spatial variability during geothermal heat pump operation. The underlying rationale is that for control of ground temperature evolution, knowledge of the primary heat sources is fundamental. This insight is also important to judge the validity of simplified modelling frameworks. For instance, we reveal that vertical heat flux from the surface dominates the basal heat flux towards a borehole. Both fluxes need to be accounted for as proper vertical boundary conditions in the model. Additionally, the role of horizontal groundwater advection is inspected. Moreover, by adopting the ground energy deficit and long-term replenishment as criteria for system sustainability, an uncommon perspective is adopted that is based on the primary parameter rather than induced local temperatures. In our synthetic study and dimensionless analysis, we demonstrate that time of ground energy recovery after system shutdown may be longer than what is expected from local temperature trends. In contrast, unrealistically long recovery periods and extreme thermal anomalies are predicted without account for vertical ground heat fluxes and only when the energy content of the geothermal reservoir is considered.

  9. Powered ankle-foot prosthesis to assist level-ground and stair-descent gaits.

    Science.gov (United States)

    Au, Samuel; Berniker, Max; Herr, Hugh

    2008-05-01

    The human ankle varies impedance and delivers net positive work during the stance period of walking. In contrast, commercially available ankle-foot prostheses are passive during stance, causing many clinical problems for transtibial amputees, including non-symmetric gait patterns, higher gait metabolism, and poorer shock absorption. In this investigation, we develop and evaluate a myoelectric-driven, finite state controller for a powered ankle-foot prosthesis that modulates both impedance and power output during stance. The system employs both sensory inputs measured local to the external prosthesis, and myoelectric inputs measured from residual limb muscles. Using local prosthetic sensing, we first develop two finite state controllers to produce biomimetic movement patterns for level-ground and stair-descent gaits. We then employ myoelectric signals as control commands to manage the transition between these finite state controllers. To transition from level-ground to stairs, the amputee flexes the gastrocnemius muscle, triggering the prosthetic ankle to plantar flex at terminal swing, and initiating the stair-descent state machine algorithm. To transition back to level-ground walking, the amputee flexes the tibialis anterior muscle, triggering the ankle to remain dorsiflexed at terminal swing, and initiating the level-ground state machine algorithm. As a preliminary evaluation of clinical efficacy, we test the device on a transtibial amputee with both the proposed controller and a conventional passive-elastic control. We find that the amputee can robustly transition between the finite state controllers through direct muscle activation, allowing rapid transitioning from level-ground to stair walking patterns. Additionally, we find that the proposed finite state controllers result in a more biomimetic ankle response, producing net propulsive work during level-ground walking and greater shock absorption during stair descent. The results of this study highlight the

  10. NASA solar dynamic ground test demonstration (GTD) program and its application to space nuclear power

    Science.gov (United States)

    Harper, William B.; Shaltens, Richard K.

    1993-01-01

    Closed Brayton cycle power conversion systems are readily adaptable to any heat source contemplated for space application. The inert gas working fluid can be used directly in gas-cooled reactors and coupled to a variety of heat sources (reactor, isotope or solar) by a heat exchanger. This point is demonstrated by the incorporation in the NASA 2 kWe Solar Dynamic (SD) Space Power Ground Test Demonstration (GTD) Program of the turboalternator-compressor and recuperator from the Brayton Isotope Power System (BIPS) program. This paper will review the goals and status of the SD GTD Program, initiated in April 1992. The performance of the BIPS isotope-heated system will be compared to the solar-heated GTD system incorporating the BIPS components and the applicability of the GTD test bed to dynamics space nuclear power R&D will be discussed.

  11. Ground return effect on wave propagation parameters of overhead power cables

    Energy Technology Data Exchange (ETDEWEB)

    Malo Machado, V.M.; Brandao Faria, J.A.; Borges da Silva, J.F. (Centro de Electrotecnia da Univ. Tecnia de Lisboa, Inst. Superior Tecnico, Dept. of Electrical Engineering, 1096 Lisboa Codex (PT))

    1990-04-01

    The propagation properties of overhead three-phase cables are usually analyzed assuming that the pipe conductor establishes a perfect shielding between the inner conductor set and any outer conductor, i.e., the power cable is assumed as an isolated system. The influence of a lossy ground plane in the neighborhood of the cable is examined in this paper. The propagation parameters for both approaches are compared---significative differences being found to exist, in the zero mode, at low working frequencies.

  12. Ground moving target signal model and power calculation in forward scattering micro radar

    Institute of Scientific and Technical Information of China (English)

    LONG Teng; HU Cheng; MIKHAIL Cherniakov

    2009-01-01

    Forward scattering micro radar is used for situation awareness;its operational range is relatively short because of the battery power and local horizon,the free space propagation model is not appropriate.The ground moving targets,such as humans,cars and tanks,have only comparable size with the transmitted signal wavelength;the point target model and the linear change of observation angle are not applicable.In this paper,the signal model of ground moving target is developed based on the case of forward scattering micro radar,considering the two-ray propagation model and area target model,and nonlinear change of observation angle as well as high order phase error.Furthermore,the analytical form of the received power from moving target has been obtained.Using the simulated forward scattering radar cross section,the received power of theoretical calculation is near to that of measured data.In addition,the simulated signal model of ground moving target is perfectly matched with the experimented data.All these results show the correctness of analytical calculation completely.

  13. Schemed Power-augmented Flow for Wing-in-ground Effect Craft in Cruise

    Institute of Scientific and Technical Information of China (English)

    YANG Wei; YANG Zhigang

    2011-01-01

    To provide detailed insight into schemed power-angmented flow for wing-in-ground effect (WIG) craft in view of the concept of cruising with power assistance, this paper presents a numerical study.The engine installed before the wing for power-augmented flow is replaced by a simplified engine model in the simulations, and is considered to be equipped with a thrust vector nozzle.Flow features with different deflected nozzle angles are studied.Comparisons are made on aerodynamics to evaluate performance of power-augmented ram (PAR) modes in cruise.Considerable schemes of power-augmented flow in cruise are described.The air blown from the PAR engine accelerates the flow around wing and a high-speed attached flow near the trailing edge is recorded for certain deflected nozzle angles.This effect takes place and therefore the separation is prevented not only at the trailing edge but also on the whole upper side.The realization of suction varies with PAR modes.It is also found that scheme of blowing air under the wing for PAR engine is aerodynamically not efficient in cruise.The power-augmented flow is extremely complicated.The numerical results give clear depiction of the flow.Optimal scheme of power-augmented flow with respect to the craft in cruise depends on the specific engines and the flight regimes.

  14. Ground acceleration in a nuclear power plant; Aceleracion del suelo en una central nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Pena G, P.; Balcazar, M.; Vega R, E., E-mail: pablo.pena@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2015-09-15

    A methodology that adopts the recommendations of international organizations for determining the ground acceleration at a nuclear power plant is outlined. Systematic presented here emphasizes the type of geological, geophysical and geotechnical studies in different areas of influence, culminating in assessments of Design Basis earthquake and the earthquake Operating Base. The methodology indicates that in regional areas where the site of the nuclear power plant is located, failures are identified in geological structures, and seismic histories of the region are documented. In the area of detail geophysical tools to generate effects to determine subsurface propagation velocities and spectra of the induced seismic waves are used. The mechanical analysis of drill cores allows estimating the efforts that generate and earthquake postulate. Studies show that the magnitude of the Fukushima earthquake, did not affect the integrity of nuclear power plants due to the rocky settlement found. (Author)

  15. Flight validation of ground-based assessment for control power requirements at high angles of attack

    Science.gov (United States)

    Ogburn, Marilyn E.; Ross, Holly M.; Foster, John V.; Pahle, Joseph W.; Sternberg, Charles A.; Traven, Ricardo; Lackey, James B.; Abbott, Troy D.

    1994-01-01

    A review is presented in viewgraph format of an ongoing NASA/U.S. Navy study to determine control power requirements at high angles of attack for the next generation high-performance aircraft. This paper focuses on recent flight test activities using the NASA High Alpha Research Vehicle (HARV), which are intended to validate results of previous ground-based simulation studies. The purpose of this study is discussed, and the overall program structure, approach, and objectives are described. Results from two areas of investigation are presented: (1) nose-down control power requirements and (2) lateral-directional control power requirements. Selected results which illustrate issues and challenges that are being addressed in the study are discussed including test methodology, comparisons between simulation and flight, and general lessons learned.

  16. Losses Analysis of Different Grounding Schemes for Transformer-less Wind Turbine with Full-Scale Power Converter

    DEFF Research Database (Denmark)

    Sztykiel, Michal; Teodorescu, Remus; Munk-Nielsen, Stig;

    2013-01-01

    Following work examines IGBT power loss and temperature distribution with regard to specific grounding method for the future concept of transformer-less offshore wind turbine. Analysis is performed via steady-state IGBT power loss estimator, which is made based on averaging of repetitive pulse...... cycles. Obtained results are validated with the experimental test set-up consisting of high power IGBTs....

  17. Seismic Response of Power Transmission Tower-Line System Subjected to Spatially Varying Ground Motions

    Directory of Open Access Journals (Sweden)

    Li Tian

    2010-01-01

    Full Text Available The behavior of power transmission tower-line system subjected to spatially varying base excitations is studied in this paper. The transmission towers are modeled by beam elements while the transmission lines are modeled by cable elements that account for the nonlinear geometry of the cables. The real multistation data from SMART-1 are used to analyze the system response subjected to spatially varying ground motions. The seismic input waves for vertical and horizontal ground motions are also generated based on the Code for Design of Seismic of Electrical Installations. Both the incoherency of seismic waves and wave travel effects are accounted for. The nonlinear time history analytical method is used in the analysis. The effects of boundary conditions, ground motion spatial variations, the incident angle of the seismic wave, coherency loss, and wave travel on the system are investigated. The results show that the uniform ground motion at all supports of system does not provide the most critical case for the response calculations.

  18. Protection Method of Biological Lightning Safety around Power Grid Based on Grounding Electrode Structure

    Science.gov (United States)

    Sixiang, Chen; Daopin, Chen; Ming, Zhang; Xiao, Huang; Jian, He; Zhijie, He

    2017-05-01

    Aimed at the actual situation of fish death in fish ponds near the power transmission line towers after the thunderstorm happened in Guangdong Province in China, this paper studied the influence of the ground current on fish in the pond. Firstly, This paper studied the current density of the fish without protection. On this basis, paper studied the horizontal pole with full-shielded, the vertical pole with half-shielded, the horizontal pole with extension three kinds of protective measures and effects. Finally an effective protection scheme was put forward according to the engineering practice. The results can provide some engineering guidance and quantitative basis for the design and modification of grounding devices when the tower is adjacent to the fish ponds in southern China.

  19. Low-speed aerodynamic characteristics of a powered NASP-like configuration in ground effect

    Science.gov (United States)

    Gatlin, Gregory M.

    1989-01-01

    Results are presented on the low-speed aerodynamic characteristics of a simplified NASP (for National Aerospace Plane Program)-like configuration, obtained in the NASA-Langley 14-by-22-foot subsonic tunnel. The model consisted of a triangular wedge forebody, a rectangular midsection housing the propulsion simulation system, and a rectangular wedge aftbody; it also included a delta wing, exhaust flow deflectors, and aftbody fences. Flow visualization was obtained by injecting water into the engine simulator inlets and using a laser light sheet to illuminate the resulting exhaust flow. It was found that power-on ground effects for NASP-like configuration can be substantial; these effects can be reduced by increasing the angle-of-attack to the value of the aftbody ramp angle. Power-on lift losses in ground effect increased with increasing thrust, but could be reduced by the addition of a delta wing to the configuration. Power-on lift losses also increased with use of aftbody fences.

  20. Ground States for the Schrödinger Systems with Harmonic Potential and Combined Power-Type Nonlinearities

    Directory of Open Access Journals (Sweden)

    Baiyu Liu

    2014-01-01

    Full Text Available We consider a class of coupled nonlinear Schrödinger systems with potential terms and combined power-type nonlinearities. We establish the existence of ground states, by using a variational method. As an application, some symmetry results for ground states of Schrödinger systems with harmonic potential terms are obtained.

  1. Autonomous Inspection Robot for Power Transmission Lines Maintenance While Operating on the Overhead Ground Wires

    Directory of Open Access Journals (Sweden)

    Zheng Li

    2011-01-01

    Full Text Available This paper describes the development of a mobile robot capable of clearing such obstacles as counterweights, anchor clamps, and torsion tower. The mobile robot walks on overhead ground wires in 500KV power tower. Its ultimate purpose is to automate to inspect the defect of power transmission line. The robot with 13 motors is composed of two arms, two wheels, two claws, two wrists, etc. Each arm has 4 degree of freedom. Claws are also mounted on the arms. An embedded computer based on PC/104 is chosen as the core of control system. Visible light and thermal infrared cameras are installed to obtain the video and temperature information, and the communication system is based on wireless LAN TCP/IP protocol. A prototype robot was developed with careful considerations of mobility. The new sensor configuration is used for the claw to grasp the overhead ground wires. The bridge is installed in the torsion tower for the robot easy to cross obstacles. The new posture plan is proposed for obstacles cleaning in the torsion tower. Results of experiments demonstrate that the robot can be applied to execute the navigation and inspection tasks.

  2. Autonomous Inspection Robot for Power Transmission Lines Maintenance While Operating on the Overhead Ground Wires

    Directory of Open Access Journals (Sweden)

    Zheng Li

    2010-12-01

    Full Text Available This paper describes the development of a mobile robot capable of clearing such obstacles as counterweights, anchor clamps, and torsion tower. The mobile robot walks on overhead ground wires in 500KV power tower. Its ultimate purpose is to automate to inspect the defect of power transmission line. The robot with 13 motors is composed of two arms, two wheels, two claws, two wrists, etc. Each arm has 4 degree of freedom. Claws are also mounted on the arms. An embedded computer based on PC/104 is chosen as the core of control system. Visible light and thermal infrared cameras are installed to obtain the video and temperature information, and the communication system is based on wireless LAN TCP/IP protocol. A prototype robot was developed with careful considerations of mobility. The new sensor configuration is used for the claw to grasp the overhead ground wires. The bridge is installed in the torsion tower for the robot easy to cross obstacles. The new posture plan is proposed for obstacles cleaning in the torsion tower. Results of experiments demonstrate that the robot can be applied to execute the navigation and inspection tasks.

  3. Ground test challenges in the development of the Space Shuttle orbiter auxiliary power unit

    Science.gov (United States)

    Chaffee, N. H.; Lance, R. J.; Weary, D. P.

    1984-01-01

    A conventional aircraft hydraulic system design approach was selected to provide fluid power for the Space Shuttle Orbiter. Developing the power unit, known as the Auxiliary Power Unit (APU), to drive the hydraulic pumps presented a major technological challenge. A small, high speed turbine drive unit powered by catalytically decomposed hydrazine and operating in the pulse mode was selected to meet the requirement. Because of limitations of vendor test facilities, significant portions of the development, flight qualification, and postflight anomaly testing of the Orbiter APU were accomplished at the Johnson Space Center (JSC) test facilities. This paper discusses the unique requirements of attitude, gravity forces, pressure profiles, and thermal environments which had to be satisfied by the APU, and presents the unique test facility and simulation techniques employed to meet the ground test requirements. In particular, the development of the zero-g lubrication system, the development of necessary APU thermal control techniques, the accomplishment of integrated systems tests, and the postflight investigation of the APU lube oil cooler behavior are discussed.

  4. NASA Boeing 757 HIRF test series low power on-the-ground tests

    Energy Technology Data Exchange (ETDEWEB)

    Poggio, A.J.; Pennock, S.T.; Zacharias, R.A.; Avalle, C.A.; Carney, H.L. [National Aeronautics and Space Administration, Langley AFB, VA (United States). Langley Research Center

    1996-08-01

    The data acquisition phase of a program intended to provide data for the validation of computational, analytical, and experimental techniques for the assessment of electromagnetic effects in commercial transports; for the checkout of instrumentation for following test programs; and for the support of protection engineering of airborne systems has been completed. Funded by the NASA Fly-By-Light/ Power-By-Wire Program, the initial phase involved on-the-ground electromagnetic measurements using the NASA Boeing 757 and was executed in the LESLI Facility at the USAF Phillips Laboratory. The major participants in this project were LLNL, NASA Langley Research Center, Phillips Laboratory, and UIE, Inc. The tests were performed over a five week period during September through November, 1994. Measurements were made of the fields coupled into the aircraft interior and signals induced in select structures and equipment under controlled illumination by RF fields. A characterization of the ground was also performed to permit ground effects to be included in forthcoming validation exercises. This report and the associated test plan that is included as an appendix represent a definition of the overall on-the-ground test program. They include descriptions of the test rationale, test layout, and samples of the data. In this report, a detailed description of each executed test is provided, as is the data identification (data id) relating the specific test with its relevant data files. Samples of some inferences from the data that will be useful in protection engineering and EM effects mitigation are also presented. The test plan which guided the execution of the tests, a test report by UIE Inc., and the report describing the concrete pad characterization are included as appendices.

  5. Balancing power: A grounded theory study on partnership of academic service institutes.

    Science.gov (United States)

    Heshmati Nabavi, Fatemeh; Vanaki, Zohreh; Mohammadi, Eesa; Yazdani, Shahram

    2017-07-01

    Governments and professional organizations have called for new partnerships between health care providers and academics to improve clinical education for the benefit of both students and patients. To develop a substantive grounded theory on the process of forming academic-service partnerships in implementing clinical education, from the perspective of academic and clinical nursing staff members and managers working in Iranian settings. The participants included 15 hospital nurses, nurse managers, nurse educators, and educational managers from two central universities and clinical settings from 2009 to 2012. Data were collected through 30 in-depth, semi-structure interviews with the individual participants and then analyzed using the methodology of Strauss and Corbin's grounded theory. Utilizing "balancing power" as the core variable enabled us to integrate the concepts concerning the partnership processes between clinical and educational institutes. Three distinct and significant categories emerged to explain the process of partnership: 1) divergence, 2) conflict between educational and caring functions, and 3) creation of balance between educational and caring functions. In implementing clinical education, partnerships have been formed within a challenging context in Iran. Conflict between clinical and educational functions was the main concern of both sides of the partnership in forming a collaborative relationship, with our findings emphasizing the importance of nursing educators' role in the establishment of partnership programs.

  6. New fault location system for power transmission lines using composite fiber-optic overhead ground wire (OPGW)

    Energy Technology Data Exchange (ETDEWEB)

    Urasawa, K. (Tokyo Electric Power Co., Inc. (Japan)); Kanemaru, K.; Toyota, S.; Sugiyama, K. (Hitachi Cable, Ltd., Tokyo (Japan))

    1989-10-01

    A new fault location (FL) method using composite fiber-optic overhead ground wires (OPGWs) is developed to find out where electrical faults occur on overhead power transmission lines. This method locates the fault section by detecting the current induced in the ground wire (GW), i.e. OPGW in this system. Since detected fault information is essentially uncertain, the new FL method treats the fault information oas a current distribution pattern throughout the power line, and applies Fuzzy Theory to realize the human-like manner of fault location used by electrical power engineers. It was confirmed by computer simulations that the fault section can be accurately located using this method under various conditions. This FL system has already been applied to several commercial power transmission lines and successfully located the sections where electrical faults occurred on actual power transmission lines.

  7. Modeling and Analysis of Mesh Tree Hybrid Power/Ground Networks with Multiple Voltage Supply in Time Domain

    Institute of Scientific and Technical Information of China (English)

    Yi-Ci Cai; Jin Shi; Zu-Ying Luo; Xian-Long Hong

    2005-01-01

    This paper proposes a novel algorithm, which can be used to model and analyze mesh tree hybrid power/ground distribution networks with multiple voltage supply in time domain. Not only this algorithm enhances common method's ability on analysis of power/ground network with irregular topology, but also very high accuracy it keeps. The accuracy and stability of this algorithm is proved using strict math method in this paper. Also, the usage of both precondition technique based on Incomplete Choleskey Decomposition and fast variable elimination technique has improved the algorithm's efficiency a lot. Experimental results show that it can finish the analysis of power/ground network with enormous size within very short time. Also, this algorithm can be applied to analyze the clock network, bus network, and signal network without buffer under high working frequency because of the independence of the topology.

  8. A New Method of Ground Fault Location in 2 × 25 kV Railway Power Supply Systems

    Directory of Open Access Journals (Sweden)

    Jesús Serrano

    2017-03-01

    Full Text Available Owing to the installation of autotransformers at regular intervals along the line, distance protection relays cannot be used with the aim of locating ground faults in 2 × 25 kV railway power supply systems. The reason is that the ratio between impedance and distance to the fault point is not linear in these electrification systems, unlike in 1 × 25 kV power systems. Therefore, the location of ground faults represents a complicated task in 2 × 25 kV railway power supply systems. Various methods have been used to localize the ground fault position in 2 × 25 kV systems. The method described here allows the location of a ground fault to be economically found in an accurate way in real time, using the modules of the circulating currents in different autotransformers when the ground fault occurs. This method first needs to know the subsection and the conductor (catenary or feeder with the defect, then localizes the ground fault’s position.

  9. Efficient statistical analysis method of power/ground (P/G) network

    Institute of Scientific and Technical Information of China (English)

    Zuying Luo; Sheldon X.D. Tan

    2008-01-01

    In this paper, we propose an incremental statistical analysis method with complexity reduction as a pre-process for on-chip power/ground (P/G) networks. The new method exploits locality of P/G network analyses and aims at P/G networks with a large number of strongly connected subcircuits (called strong connects) such as trees and chains. The method consists of three steps. First it compresses P/G circuits by removing strong connects. As a result, current variations (CVs) of nodes in strong connects are transferred to some remain-ing nodes. Then based on the locality of power grid voltage responses to its current inputs, it efficiently calculates the correlative resistor (CR) matrix in a local way to directly compute the voltage variations by using small parts of the remaining circuit. Last it statistically recovers voltage variations of the suppressed nodes inside strong connects. This new method for statistically compressing and expanding strong connects in terms of current or voltage variations in a closed form is very efficient owning to its property of incremental analysis. Experimental results demonstrate that the method can efficiently compute low-bounds of voltage variations for P/G networks and it has two or three orders of magnitudes speedup over the traditional Monte-Carlo-based simulation method, with only 2.0% accuracy loss.

  10. Work and Risk: Perceptions of Nuclear-Power Personnel. a Study in Grounded Theory.

    Science.gov (United States)

    Fields, Claire Dewitt

    1992-01-01

    The utility industry has devoted time and money to assure personnel within nuclear power plants are informed about occupational risks. Radiation-protection training programs are designed to present information to employees about occupational radiation and protective procedures. Work -related concerns are known to create stress, affect the morale of the workforce, influence collective bargaining, and increase compensation claims. This study was designed to determine perceptions of risk among employees of nuclear power plants and identify variables that influence these perceptions. Four power plants were included in the study, one in Canada and three in the United States. Data were generated through participant observations and interviews of 350 participants during a period of 3 weeks at each plant. Data were gathered and analyzed following procedures advanced by Grounded Theory, a naturalistic methodology used in this study. Training content, information, and communication materials were additional sources of data. Findings indicated employees believed health and safety risks existed within the work environment. Perceptions of risk were influenced by training quality, the work environment, nuclear myths and images of the general public, and fears of family members. Among the three groups of workers, administration personnel, security personnel, and radiation workers, the latter identified a larger number of risks. Workers perceived radiation risks, shift work, and steam pipe ruptures as high-level concerns. Experiencing stress, making mistakes, and fear of sabotage were concerns shared among all employee groups at various levels of concern. Strategies developed by employees were used to control risk. Strategies included teamwork, humor, monitoring, avoidance, reframing, and activism. When risks were perceived as uncontrollable, the employee left the plant. A coping strategy of transferring concerns about radiological risks to nonradiological risks were uncovered in

  11. Discontinuous Galerkin Time-Domain Analysis of Power-Ground Planes Taking Into Account Decoupling Capacitors

    KAUST Repository

    Li, Ping

    2017-03-22

    In this paper, a discontinuous Galerkin time-domain (DGTD) method is developed to analyze the power-ground planes taking into account the decoupling capacitors. In the presence of decoupling capacitors, the whole physical system can be split into two subsystems: 1) the field subsystem that is governed by Maxwell\\'s equations that will be solved by the DGTD method, and 2) the circuit subsystem including the capacitor and its parasitic inductor and resistor, which is going to be characterized by the modified nodal analysis algorithm constructed circuit equations. With the aim to couple the two subsystems together, a lumped port is defined over a coaxial surface between the via barrel and the ground plane. To reach the coupling from the field to the circuit subsystem, a lumped voltage source calculated by the integration of electric field along the radial direction is introduced. On the other hand, to facilitate the coupling from the circuit to field subsystem, a lumped port current source calculated from the circuit equation is introduced, which serves as an impressed current source for the field subsystem. With these two auxiliary terms, a hybrid field-circuit matrix equation is established, which enables the field and circuit subsystems are solved in a synchronous scheme. Furthermore, the arbitrarily shaped antipads are considered by enforcing the proper wave port excitation using the magnetic surface current source derived from the antipads supported electric eigenmodes. In this way, the S-parameters corresponding to different modes can be conveniently extracted. To further improve the efficiency of the proposed algorithm in handling multiscale meshes, the local time-stepping marching scheme is applied. The proposed algorithm is verified by several representative examples.

  12. Comparisons of peak ground reaction force and rate of force development during variations of the power clean.

    Science.gov (United States)

    Comfort, Paul; Allen, Mark; Graham-Smith, Phillip

    2011-05-01

    The aim of this investigation was to determine the differences in vertical ground reaction forces and rate of force development (RFD) during variations of the power clean. Elite rugby league players (n = 11; age 21 ± 1.63 years; height 181.56 ± 2.61 cm; body mass 93.65 ± 6.84 kg) performed 1 set of 3 repetitions of the power clean, hang-power clean, midthigh power clean, or midthigh clean pull, using 60% of 1-repetition maximum power clean, in a randomized order, while standing on a force platform. Differences in peak vertical ground reaction forces (F(z)) and instantaneous RFD between lifts were analyzed via 1-way analysis of variance and Bonferroni post hoc analysis. Statistical analysis revealed a significantly (p < 0.001) greater peak F(z) during the midthigh power clean (2,801.7 ± 195.4 N) and the midthigh clean pull (2,880.2 ± 236.2 N) compared to both the power clean (2,306.24 ± 240.47 N) and the hang-power clean (2,442.9 ± 293.2 N). The midthigh power clean (14,655.8 ± 4,535.1 N·s⁻¹) and the midthigh clean pull (15,320.6 ± 3,533.3 N·s⁻¹) also demonstrated significantly (p < 0.001) greater instantaneous RFD when compared to both the power clean (8,839.7 ± 2,940.4 N·s⁻¹) and the hang-power clean (9,768.9 ± 4,012.4 N·s⁻¹). From the findings of this study, when training to maximize peak F(z) and RFD the midthigh power clean and midthigh clean pull appear to be the most advantageous variations of the power clean to perform.

  13. Compensation of Cable Voltage Drops and Automatic Identification of Cable Parameters in 400 Hz Ground Power Units

    DEFF Research Database (Denmark)

    Borup, Uffe; Nielsen, Bo Vork; Blaabjerg, Frede

    2004-01-01

    In this paper a new cable voltage drop compensation scheme for ground power units (GPU) is presented. The scheme is able to predict and compensate the voltage drop in an output cable by measuring the current quantities at the source. The prediction is based on an advanced cable model that includes...

  14. Reduction of Static Power with Minimized Ground Bounce Noise Using Sleep Signal Slew Rate Modulation In 45nm Technology

    Directory of Open Access Journals (Sweden)

    M. Naga Pramod Reddy

    2014-06-01

    Full Text Available In MTCMOS Integrated Circuit design there exists a significant trade-off between static power consumption and technology scaling. In Modern circuits increase in power dissipation is significant due to combination of higher clock speeds, greater functional integration and smaller process geometries resulting in dominant static power consumption component. This is a big challenge for the circuit designer. However, the designers do have few methods like sleep transistor approach, sleepy stack approach to reduce this static power consumption. However all of these methods do have their own drawbacks. In order to achieve lower static power consumptions one has to sacrifice area and circuit performance metrics. In this paper we propose a new enhancement to available static power reduction techniques by modulating the sleep signal slew rate. We have designed the basic CMOS circuits in MTCMOS to achieve significant reduction in Static power consumption. For Sleep signal slew rate modulation we have proposed a modulator called triple phase sleep signal slew rate modulator. By using this Triple Phase Sleep signal modulator(TPS we can control the noise at ground distribution network (ground bounce noise produced during sleep to active state transition. By using TPS we can decrease the reactivation time to a recognizable extent, along with reduced power (static and dynamic dissipation.

  15. Estimation of ground reaction force and zero moment point on a powered ankle-foot prosthesis.

    Science.gov (United States)

    Martinez-Villalpando, Ernesto C; Herr, Hugh; Farrell, Matthew

    2007-01-01

    The ground reaction force (GRF) and the zero moment point (ZMP) are important parameters for the advancement of biomimetic control of robotic lower-limb prosthetic devices. In this document a method to estimate GRF and ZMP on a motorized ankle-foot prosthesis (MIT Powered Ankle-Foot Prosthesis) is presented. The method proposed is based on the analysis of data collected from a sensory system embedded in the prosthetic device using a custom designed wearable computing unit. In order to evaluate the performance of the estimation methods described, standing and walking clinical studies were conducted on a transtibial amputee. The results were statistically compared to standard analysis methodologies employed in a gait laboratory. The average RMS error and correlation factor were calculated for all experimental sessions. By using a static analysis procedure, the estimation of the vertical component of GRF had an averaged correlation coefficient higher than 0.94. The estimated ZMP location had a distance error of less than 1 cm, equal to 4% of the anterior-posterior foot length or 12% of the medio-lateral foot width.

  16. Calculation of Electric Field at Ground Surface and ADSS Cable Prepared Hanging Point near EHV Power Transmission Tower

    Directory of Open Access Journals (Sweden)

    Xu Bao-Qing

    2016-01-01

    Full Text Available A simplified model of the 750kV tower is established by CDEGS software which is based on the Method Of Moment. The power frequency electric field distribution on the ground is achieved by software calculation and field-measuring. The validity of the calculation is proved when compare the calculation and experiment results. The model also can be used to calculate the electric field in prepared hanging points on the tower. Results show that the electric field distribution on the ground surface around the tower and prepared hanging points are meet the standard by calculation and experiment.

  17. Lightning current test of power ground wires with optical fibres (OPGW); Blitzstromfestigkeitspruefung von Erdseilen mit integrierten Lichtwellenleitern

    Energy Technology Data Exchange (ETDEWEB)

    Boehme, M. [VEW EuroTest GmbH, Dortmund (Germany); Moeller, K. [Technische Hochschule Aachen (Germany). Inst. fuer Allgemeine Elektrotechnik und Hochspannungstechnik; Nolden, W. [Felten und Guilleaume Energietechnik AG, Koeln (Germany)

    1998-09-21

    The area-wide application of ground wires with integrated optical fibers establishes a basis to use the existing overhead lines in addition to power supply also as communication networks. Taking in account the particular lightning stroke endangering of overhead lines a basic study of the thermal stress and damage progression of this ground wire type during a lightning stroke is necessary. (orig.) [Deutsch] Der Einsatz von Erdseilen mit integrierten Lichtwellenleitern schafft die Voraussetzung, bestehende Freileitungstrassen nicht nur zur Energieversorgung zu nutzen, sondern auch als Kommunikationsnetze zu betreiben. Unter Beruecksichtigung der besonderen Blitzeinschlagsgefaehrdung von Freileitungstrassen ist eine grundlegende Untersuchung der thermischen Beanspruchung und der Schadensentwicklung dieses Erdseiltyps waehrend eines Blitzeinschlags notwendig. (orig.)

  18. Testing of ground fault relay response during the energisation of megawatt range electric boilers in thermal power plants

    DEFF Research Database (Denmark)

    Silva, Filipe Miguel Faria da; Bak, Claus Leth; Davidsen, Troels

    2015-01-01

    , during the energisation of a boiler. A special case for concern was the presence of an electric arc between the electrodes of the boiler and the water in the boiler during approximately 2s at the energisation, which can in theory be seen as a ground fault by the relay. The voltage and current transient......Large controllable loads may support power systems with an increased penetration of fluctuating renewable energy, by providing a rapid response to a change in the power production. Megawatt range electric boilers are an example of such controllable loads, capable of change rapidly...

  19. Enhanced static ground power unit based on flying capacitor based h-bridge hybrid active-neutral-point-clamped converter

    DEFF Research Database (Denmark)

    Abarzadeh, Mostafa; Madadi Kojabadi, Hossein; Deng, Fujin

    2016-01-01

    Static power converters have various applications, such as static ground power units (GPUs) for airplanes. This study proposes a new configuration of a static GPU based on a novel nine-level flying capacitor h-bridge active-neutral-point-clamped (FCHB_ANPC) converter. The main advantages...... improvement in GPU dynamic performances. This progress is achieved by utilising the proposed FCHB converter to an ANPC converter and using the suggested modulation method. This leads to diminish the size and cost and enhance the feasibility and reliability of the converter. Applying the proposed modulation...

  20. Vertical ground reaction force-based analysis of powered exoskeleton-assisted walking in persons with motor-complete paraplegia.

    Science.gov (United States)

    Fineberg, Drew B; Asselin, Pierre; Harel, Noam Y; Agranova-Breyter, Irina; Kornfeld, Stephen D; Bauman, William A; Spungen, Ann M

    2013-07-01

    To use vertical ground reaction force (vGRF) to show the magnitude and pattern of mechanical loading in persons with spinal cord injury (SCI) during powered exoskeleton-assisted walking. A cross-sectional study was performed to analyze vGRF during powered exoskeleton-assisted walking (ReWalk™: Argo Medical Technologies, Inc, Marlborough, MA, USA) compared with vGRF of able-bodied gait. Veterans Affairs Medical Center. Six persons with thoracic motor-complete SCI (T1-T11 AIS A/B) and three age-, height-, weight- and gender-matched able-bodied volunteers participated. SCI participants were trained to ambulate over ground using a ReWalk™. vGRF was recorded using the F-Scan™ system (TekScan, Boston, MA, USA). Peak stance average (PSA) was computed from vGRF and normalized across all participants by percent body weight. Peak vGRF was determined for heel strike, mid-stance, and toe-off. Relative linear impulse and harmonic analysis provided quantitative support for analysis of powered exoskeletal gait. Participants with motor-complete SCI, ambulating independently with a ReWalk™, demonstrated mechanical loading magnitudes and patterns similar to able-bodied gait. Harmonic analysis of PSA profile by Fourier transform contrasted frequency of stance phase gait components between able-bodied and powered exoskeleton-assisted walking. Powered exoskeleton-assisted walking in persons with motor-complete SCI generated vGRF similar in magnitude and pattern to that of able-bodied walking. This suggests the potential for powered exoskeleton-assisted walking to provide a mechanism for mechanical loading to the lower extremities. vGRF profile can be used to examine both magnitude of loading and gait mechanics of powered exoskeleton-assisted walking among participants of different weight, gait speed, and level of assist.

  1. A Single Phase Doubly Grounded Semi-Z-Source Inverter for Photovoltaic (PV Systems with Maximum Power Point Tracking (MPPT

    Directory of Open Access Journals (Sweden)

    Tofael Ahmed

    2014-06-01

    Full Text Available In this paper, a single phase doubly grounded semi-Z-source inverter with maximum power point tracking (MPPT is proposed for photovoltaic (PV systems. This proposed system utilizes a single-ended primary inductor (SEPIC converter as DC-DC converter to implement the MPPT algorithm for tracking the maximum power from a PV array and a single phase semi-Z-source inverter for integrating the PV with AC power utilities. The MPPT controller utilizes a fast-converging algorithm to track the maximum power point (MPP and the semi-Z-source inverter utilizes a nonlinear SPWM to produce sinusoidal voltage at the output. The proposed system is able to track the MPP of PV arrays and produce an AC voltage at its output by utilizing only three switches. Experimental results show that the fast-converging MPPT algorithm has fast tracking response with appreciable MPP efficiency. In addition, the inverter shows the minimization of common mode leakage current with its ground sharing feature and reduction of the THD as well as DC current components at the output during DC-AC conversion.

  2. Effects of a powered ankle-foot prosthesis on kinetic loading of the unaffected leg during level-ground walking.

    Science.gov (United States)

    Grabowski, Alena M; D'Andrea, Susan

    2013-06-07

    People with a lower-extremity amputation that use conventional passive-elastic ankle-foot prostheses encounter a series of stress-related challenges during walking such as greater forces on their unaffected leg, and may thus be predisposed to secondary musculoskeletal injuries such as chronic joint disorders. Specifically, people with a unilateral transtibial amputation have an increased susceptibility to knee osteoarthritis, especially in their unaffected leg. Previous studies have hypothesized that the development of this disorder is linked to the abnormally high peak knee external adduction moments encountered during walking. An ankle-foot prosthesis that supplies biomimetic power could potentially mitigate the forces and knee adduction moments applied to the unaffected leg of a person with a transtibial amputation, which could, in turn, reduce the risk of knee osteoarthritis. We hypothesized that compared to using a passive-elastic prosthesis, people with a transtibial amputation using a powered ankle-foot prosthesis would have lower peak resultant ground reaction forces, peak external knee adduction moments, and corresponding loading rates applied to their unaffected leg during walking over a wide range of speeds. We analyzed ground reaction forces and knee joint kinetics of the unaffected leg of seven participants with a unilateral transtibial amputation and seven age-, height- and weight-matched non-amputees during level-ground walking at 0.75, 1.00, 1.25, 1.50, and 1.75 m/s. Subjects with an amputation walked while using their own passive-elastic prosthesis and a powered ankle-foot prosthesis capable of providing net positive mechanical work and powered ankle plantar flexion during late stance. Use of the powered prosthesis significantly decreased unaffected leg peak resultant forces by 2-11% at 0.75-1.50 m/s, and first peak knee external adduction moments by 21 and 12% at 1.50 and 1.75 m/s, respectively. Loading rates were not significantly different

  3. Action Learning and Constructivist Grounded Theory: Powerfully Overlapping Fields of Practice

    Science.gov (United States)

    Rand, Jane

    2013-01-01

    This paper considers the shared characteristics between action learning (AL) and the research methodology constructivist grounded theory (CGT). Mirroring Edmonstone's [2011. "Action Learning and Organisation Development: Overlapping Fields of Practice." "Action Learning: Research and Practice" 8 (2): 93-102] article, which…

  4. Development of High Power Amplifiers for Space and Ground-based Applications

    DEFF Research Database (Denmark)

    Hernández, Carlos Cilla

    and the Monolithic Microwave Integrated Circuits. The research work presented here focuses on practical realization and demonstration of these two types of amplifiers. The design and experimental performance assessment of 50W Solid State C-band High Power Amplifier using European Monolithic Microwave Integrated......-based amplifiers. They are efficient and provide very high power levels operating at low duty cycles. But they have a questionable longterm reliability, large footprints and they are not suitable for modern equipment with a decentralized transmitter, like a phase array system. Solid State Power Amplifier......D dissertation lies in the development of nonlinear design methodologies, manufacturing, and efficient testing of Solid State High Power Amplifier modules, with special focus on GaN state of the art technology. It is possible to identify two types of GaN Solid State High Power Amplifiers: the Hybrids...

  5. Effect of Fly Ash Disposal on Ground Water Quality Near Parichha Thermal Power Plant, Jhansi – A Case Study

    Directory of Open Access Journals (Sweden)

    Shubham Kanchan

    2015-08-01

    Full Text Available Thermal power plant generates a huge amount of fly ash on combustion of coal which is becoming a major environmental issue. Thermal power plants are greatly facing a fly ash management problem. Open dumping of fly ash can deteriorate the groundwater quality by runoff. In the present investigation, the ground water samples were collected from nearby areas of Parichha Thermal Power Plant at six locations during the period of Jan 2014 to May 2014. The samples were taken to the laboratory and analyzed for physico-chemical properties and heavy metal content. The physico-chemical analysis was done for the parameters like pH, Turbidity, Temperature, Electrical Conductivity, Alkalinity, Total Dissolved Solids, Total Hardness, Calcium Hardness and Magnesium Hardness. The concentration of Turbidity, EC and Alkalinity was exceeding the standard at all locations and shows that the groundwater of the area is not fit for drinking. The ground water samples were also analyzed for the presence of lead and cadmium and it was found that lead was exceeding the limit although cadmium was found within the limit.

  6. Techno­-Choreographies: Aerial and grounded bodies in the early years of powered flight

    DEFF Research Database (Denmark)

    Simonsen, Dorthe Gert

    of aviation from the ground. By exploring how the early airplane ‘choreographed’ and reconfigured aerial as well as earthbound bodies, this paper tries to grasp the transformative and non-representational interactions between technology and the human embodiment of aerial mobility. As an introduction...... of flight points us to a body in transition; a body choreographed by aviation, as transformative for the few who flew, as for the many who remained below....

  7. North Germany is gaining ground in solar power generation; Der Norden holt beim Sonnenstrom auf

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2011-10-15

    In 2010, the North German states of Brandenburg and Schleswig-Holstein took second and third place in the construction of new solar systems. Bavaria is still leading. The capacity increase in the solar sector substitutes one nuclear power station.

  8. Kinematic comparison of walking on uneven ground using powered and unpowered prostheses.

    Science.gov (United States)

    Gates, Deanna H; Aldridge, Jennifer M; Wilken, Jason M

    2013-04-01

    Recent research has focused on the design of intelligent prosthetic ankle devices with the goal of adapting behavior of the device to accommodate all walking surfaces that an individual encounters in daily life. To date, no studies have looked at how such devices perform on uneven terrain. 11 young adults with unilateral transtibial amputation participated in two data collection sessions spaced approximately 3 weeks apart. In each session they walked across a loose rock surface at three controlled speeds. In the first session, they wore a passive, energy storage and return prosthesis and in the second, they wore a powered prosthesis (BiOM, iWalk, Bedford, MA, USA). Subjects had a 10% faster self-selected walking speed when wearing the powered (1.16 m/s) compared to unpowered prosthesis (1.05 m/s; p=0.031). They walked with increased ankle plantarflexion on their prosthetic limb throughout the gait cycle when wearing the powered compared to unpowered prosthesis. This was especially evident in the increased plantarflexion during push-off (p<0.001). There was a small (<3°), but statistically significant decrease in knee flexion during early stance when wearing the powered device (p=0.045). Otherwise, the kinematics of the knee and hip were nearly identical when wearing the different devices. Subjects had decreased medial-lateral motion of their center of mass when wearing the powered prosthesis (p=0.020), but there were no differences in medial-lateral margins of stability between the devices (p=0.662). Subjects did not significantly alter their proximal joint kinematics on this irregular surface as a result of the addition of power. Published by Elsevier Ltd.

  9. Ground-water quality in Bannock, Bear Lake, Caribou, and part of Power counties, southeastern Idaho

    Science.gov (United States)

    Seitz, H.R.; Norvitch, R.F.

    1979-01-01

    The 103 wells sampled during the study establish a quasi-network that could be resampled in the future to document and analyze changes in ground-water quality in the southeastern Idaho study area. The main aquifers are categorized as alluvium of Quaternary age, basalt of Quaternary and (or) Tertiary age, rocks of the Salt Lake Formation of Tertiary age, and undifferentiated bedrock of pre-Tertiary age. Dissolved solids, hardness, nitrite plus nitrate as nitrogen, and chloride concentrations in the ground waters ranged from 165 to 1,690; 78 to 1,700; 0 to 29; and 1.9 to 360 milligrams per liter, respectively. The areal distributions of these constituents are shown on maps. The range and median values of these same constituents are tabulated by aquifer occurrence. Some of the most mineralized and hardest waters occur in the basalt aquifer near travertine deposits (or terraces), which are composed of calcium carbonate precipitates from mineral springs. For irrigation purposes, all the waters are classified as having low-sodium hazard. Most have medium- to high-salinity hazard. (Woodard-USGS)

  10. Balancing power: A grounded theory study on partnership of academic service institutes

    Directory of Open Access Journals (Sweden)

    FATEMEH HESHMATI NABAVI

    2017-07-01

    Full Text Available Introduction: Governments and professional organizations have called for new partnerships between health care providers and academics to improve clinical education for the benefit of both students and patients. To develop a substantive grounded theory on the process of forming academic-service partnerships in implementing clinical education, from the perspective of academic and clinical nursing staff members and managers working in Iranian settings. Methods: The participants included 15 hospital nurses, nurse managers, nurse educators, and educational managers from two central universities and clinical settings from 2009 to 2012. Data were collected through 30 in-depth, semi-structure interviews with the individual participants and then analyzed using the methodology of Strauss and Corbin’s grounded theory. Results: Utilizing “balancing power” as the core variable enabled us to integrate the concepts concerning the partnership processes between clinical and educational institutes. Three distinct and significant categories emerged to explain the process of partnership: 1 divergence, 2 conflict between educational and caring functions, and 3 creation of balance between educational and caring functions. Conclusions: In implementing clinical education, partnerships have been formed within a challenging context in Iran. Conflict between clinical and educational functions was the main concern of both sides of the partnership in forming a collaborative relationship, with our findings emphasizing the importance of nursing educators’ role in the establishment of partnership programs.

  11. Specification requirements summary for the Brayton Isotope Power System (BIPS) Ground Demonstration System (GDS)

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, E.E.

    1976-02-10

    This document provides a summary of the required program specifications and procedures for the ERDA Phase I Brayton Isotope Power System (BIPS) Program. Also included are document definitions, descriptions, and formats, and a listing of commonly used abbreviations. This document is intended to be used as a guide in document preparation and control.

  12. Evaluation of System Architectures for the Army Aviation Ground Power Unit

    Science.gov (United States)

    2014-12-01

    for DC power ( Baldor Electric Company 2014; U.S. Army Aviation and Missile Command 2007). 14 C. CHAPTER SUMMARY This chapter examined... Baldor Electric Company. 2014. Performance Data: EJMM2334T [Pamphlet]. Fort Smith, AR: ABB Group. Balje, O. E. 1962. A Study on Design Criteria and

  13. Power Beaming, Orbital Debris Removal, and Other Space Applications of a Ground Based Free Electron Laser

    Science.gov (United States)

    2010-03-01

    successful interstellar propagation of a laser communications signal. A casual survey of the night’s sky indicates that light can travel across...laser illumination of objects within the solar system for scientific study, and interstellar laser illumination for communications. Power beaming...these ranges. FEL illumination at interstellar ranges is modeled and discussed to determine our ability to communicate or detect laser communications

  14. Analysis of the grounding system for a mobile communication site placed on HV power line mast

    Science.gov (United States)

    Bîrsan, I.; Munteanu, C.; Horgoș, M.; Ilut, T.

    2016-08-01

    This paper aims to analyze the potential distribution on the soil surface or potential variation on the main directions inside computing mobile site. I want to study a system made the earth a mobile communications site, antennas operator and the system of which the earth is placed on a High Voltage Power Line Mast (LEA 110 KV). I made direct measurements and I use a 3D software for analyze the results and simulating some possible solutions.

  15. Some evidence of ground power enhancements at frequencies of global magnetospheric modes at low latitude

    Directory of Open Access Journals (Sweden)

    P. Francia

    Full Text Available A statistical analysis of the power spectra of the geomagnetic field components H and D for periods ranging between 3 min and 1 h was conducted at a low-latitude observatory (L'Aquila, L=1.6 at the minimum and maximum of the solar cycle. For both components, during daytime intervals, we found evidence of power enhancements at frequencies predicted for global modes of the Earth's magnetosphere and occasionally observed at auroral latitudes in the F-region drift velocities (approximately at 1.3, 1.9, 2.6, and 3.4 mHz. Nighttime observations reveal a relative low frequency H enhancement associated with the bay occurrence together with a peak in the H/D power ratio which sharply emerges at 1.2 mHz in the premidnight sector. The strong similarity between solar minimum and maximum suggests that these modes can be considered permanent magnetospheric features. A separate analysis on a two-month interval shows that the observed spectral characteristics are amplified by conditions of high-velocity solar wind.

  16. Some evidence of ground power enhancements at frequencies of global magnetospheric modes at low latitude

    Science.gov (United States)

    Francia, P.; Villante, U.

    1997-01-01

    A statistical analysis of the power spectra of the geomagnetic field components H and D for periods ranging between 3 min and 1 h was conducted at a low-latitude observatory (LÁquila, L=1.6) at the minimum and maximum of the solar cycle. For both components, during daytime intervals, we found evidence of power enhancements at frequencies predicted for global modes of the Earthś magnetosphere and occasionally observed at auroral latitudes in the F-region drift velocities (approximately at 1.3, 1.9, 2.6, and 3.4 mHz). Nighttime observations reveal a relative low frequency H enhancement associated with the bay occurrence together with a peak in the H/D power ratio which sharply emerges at 1.2 mHz in the premidnight sector. The strong similarity between solar minimum and maximum suggests that these modes can be considered permanent magnetospheric features. A separate analysis on a two-month interval shows that the observed spectral characteristics are amplified by conditions of high-velocity solar wind. Acknowledgements. The authors are grateful to Prof. D. J. Southwood (Imperial College, London), J. C. Samson (University of Alberta, Edmonton), L. J. Lanzerotti (AT&T Bell Laboratories), A. Wolfe (New York City Technical College) and to Dr. M. Vellante (University of LÁquila) for helpful discussions. They also thank Dr. A. Meloni (Istituto Nazionale di Geofisica, Roma) who made available geomagnetic field observations from LÁquila Geomagnetic Observatory. This research activity at LÁquila is supported by MURST (40% and 60% contracts) and by GIFCO/CNR. Topical Editor K.-H. Glaßmeier thanks C. Waters and S. Fujita for their help in evaluating this paper.-> Francia->

  17. Studies of Plasma Instability Process Excited by Ground Based High Power HF (Heating) Facilities

    Science.gov (United States)

    2007-11-02

    the altitude z = 285 km. Night time plasma line intensities were observed to be enhanced by a factor 10 ÷ 100 extended to altitude below 250 km. When HF...waves, whose wave vector is directed toward the radar, and the phase velocity vph is equal to the velocity of suprathermal electrons v vph =(1/2) λr...averaged and in final form depends on two scalar factors only: full power density P absorbed by fast electrons in the acceleration layer, and characteristic

  18. A VCO with Harmonic Suppressed and Output Power Improved Using Defected Ground Structure

    Directory of Open Access Journals (Sweden)

    Haiwen Liu

    2003-01-01

    microstrip line with DGS has a wide low-pass band for the fundamental frequency and a stopband for the second harmonic with good performance. To evaluate the effects of DGS on microwave VCOs, two GaAs field-effect transistor (FET VCOs have been designed and fabricated. One of them has a 50Ω microstrip line with DGS at the output section, while the other has only a 50Ω straight line. Measured results show that DGS suppresses the second harmonic more than −20 dBm at the output and yields improved output power by 3−5%.

  19. Aerial Survey Results for 131I Deposition on the Ground after the Fukushima Daiichi Nuclear Power Plant Accident

    Energy Technology Data Exchange (ETDEWEB)

    Torii, Tatsuo [JAEA; Sugita, Takeshi [JAEA; Okada, Colin E. [NSTec; Reed, Michael S. [NSTec; Blumenthal, Daniel J. [NNSA

    2013-08-01

    In March 2011 the second largest accidental release of radioactivity in history occurred at the Fukushima Daiichi nuclear power plant following a magnitude 9.0 earthquake and subsequent tsunami. Teams from the U.S. Department of Energy, National Nuclear Security Administration Office of Emergency Response performed aerial surveys to provide initial maps of the dispersal of radioactive material in Japan. The initial results from the surveys did not report the concentration of 131I. This work reports on analyses performed on the initial survey data by a joint Japan-US collaboration to determine 131I ground concentration. This information is potentially useful in reconstruction of the inhalation and external exposure doses from this short-lived radionuclide. The deposited concentration of 134Cs is also reported.

  20. Dynamic input to determine hip joint moments, power and work on the prosthetic limb of transfemoral amputees: ground reaction vs knee reaction

    OpenAIRE

    FROSSARD, Laurent; Cheze, Laurence; Dumas, Raphaël

    2011-01-01

    Background: Calculation of lower limb kinetics is limited by floor-mounted force-plates. Objectives: Comparison of hip joint moments, power and mechanical work on the prosthetic limb of a transfemoral amputee calculated by inverse dynamics using either the ground reactions (force-plates) or knee reactions (transducer). Study design: Comparative analysis. Methods: Kinematics, ground reaction and knee reaction data were collected using a motion analysis system, two forceplates, and a multi-axia...

  1. Ground-based remote sensing profiling and numerical weather prediction model to manage nuclear power plants meteorological surveillance in Switzerland

    Directory of Open Access Journals (Sweden)

    B. Calpini

    2011-08-01

    Full Text Available The meteorological surveillance of the four nuclear power plants in Switzerland is of first importance in a densely populated area such as the Swiss Plateau. The project "Centrales Nucléaires et Météorologie" CN-MET aimed at providing a new security tool based on one hand on the development of a high resolution numerical weather prediction (NWP model. The latter is providing essential nowcasting information in case of a radioactive release from a nuclear power plant in Switzerland. On the other hand, the model input over the Swiss Plateau is generated by a dedicated network of surface and upper air observations including remote sensing instruments (wind profilers and temperature/humidity passive microwave radiometers. This network is built upon three main sites ideally located for measuring the inflow/outflow and central conditions of the main wind field in the planetary boundary layer over the Swiss Plateau, as well as a number of surface automatic weather stations (AWS. The network data are assimilated in real-time into the fine grid NWP model using a rapid update cycle of eight runs per day (one forecast every three hours. This high resolution NWP model has replaced the former security tool based on in situ observations (in particular one meteorological mast at each of the power plants and a local dispersion model. It is used to forecast the dynamics of the atmosphere in the planetary boundary layer (typically the first 4 km above ground layer and over a time scale of 24 h. This tool provides at any time (e.g. starting at the initial time of a nuclear power plant release the best picture of the 24-h evolution of the air mass over the Swiss Plateau and furthermore generates the input data (in the form of simulated values substituting in situ observations required for the local dispersion model used at each of the nuclear power plants locations. This paper is presenting the concept and two validation studies as well as the results of an

  2. Detecting the single line to ground short circuit fault in the submarine’s power system using the artificial neural network

    Directory of Open Access Journals (Sweden)

    Behniafar Ali

    2013-01-01

    Full Text Available The electric marine instruments are newly inserted in the trade and industry, for which the existence of an equipped and reliable power system is necessitated. One of the features of such a power system is that it cannot have an earth system causing the protection relays not to be able to detect the single line to ground short circuit fault. While on the other hand, the occurrence of another similar fault at the same time can lead to the double line fault and thereby the tripping of relays and shortening of vital loads. This in turn endangers the personals' security and causes the loss of military plans. From the above considerations, it is inferred that detecting the single line to ground fault in the marine instruments is of a special importance. In this way, this paper intends to detect the single line to ground fault in the power systems of the marine instruments using the wavelet transform and Multi-Layer Perceptron (MLP neural network. In the numerical analysis, several different types of short circuit faults are simulated on several marine power systems and the proposed approach is applied to detect the single line to ground fault. The results are of a high quality and preciseness and perfectly demonstrate the effectiveness of the proposed approach.

  3. Criteria for selecting optimum blower drives. Integrated power electronics is gaining ground in the market; Kriterien zur Auswahl des optimalen Ventilatorantriebs. Die integrierte Leistungselektronik gewinnt Marktanteile

    Energy Technology Data Exchange (ETDEWEB)

    Albig, J. [Ziehl-Abegg AG, Kuenzelsau (Germany). Fachbereich Produktmanagement

    2008-05-15

    In the field of speed controllers, systems with power electronics are gaining ground. Thes compact, matched units simplify the installation of refrigeration systems and enable reliable and efficient operation. Design concepts vary between the various producers, and blower design and technology may be quite different. (orig.)

  4. Parasitic Effects of Grounding Paths on Common-Mode EMI Filter's Performance in Power Electronics Systems

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shuo [ORNL; Maillet, Yoann [Virginia Polytechnic Institute and State University (Virginia Tech); Wang, Fei [ORNL; Lai, Rixin [General Electric; Luo, Fang [Virginia Polytechnic Institute and State University (Virginia Tech); Boroyevich, Dushan [Virginia Polytechnic Institute and State University (Virginia Tech)

    2010-01-01

    High-frequency common-mode (CM) electromagnetic-interference (EMI) noise is difficult to suppress in electronics systems. EMI filters are used to suppress CM noise, but their performance is greatly affected by the parasitic effects of the grounding paths. In this paper, the parasitic effects of the grounding paths on an EMI filter's performance are investigated in a motor-drive system. The effects of the mutual inductance between two grounding paths are explored. Guidelines for the grounding of CM EMI filters are derived. Simulations and experiments are finally carried out to verify the theoretical analysis.

  5. Developing project portfolio management model for innovation projects using grounded theory: a case of Iran’s power industry

    Directory of Open Access Journals (Sweden)

    A. Khameneh

    2016-09-01

    Full Text Available The aim of the article. Survival in a dynamic competitive environment often requires consistent produce of successful new product and services; therefore, implementing an effective Project Portfolio Management (PPM in the organization can improve innovation decisions and outcomes of new products, thereby lead to higher competitive advantage. This Paper aims at discovering the causal relationship of Innovation Project Portfolio Management (IPPM performance. The results of the analysis. Qualitative research design was chosen for this study and through using semi-structured and in-depth interviews with 24 experts in five Iranian organizations producing equipment of the power industry, we use a grounded theory approach to develop a general model of what drives IPPM in detail and how these causes are related to effects on both project performance and business performance. According to the findings from these qualitative data, effective IPPM is the result of three areas of capabilities: IPPM Process, IPPM structure, IPPM people. These causal relationships are moderated by project context. Also the findings show that performance of IPPM consist of an integrated elements of Strategic alignment, portfolio balance, resource fit and value maximization. In the other hand, IPPM performance has influences on project performance and business performance. Finally, a set of propositions regarding the key performance drivers of IPPM were developed. Conclusions and directions of further researches. In conclusion, this study contributes new insights to the emerging research on IPPM. While most IPPM literature is still a theoretical, this paper develops IPPM in the context of the Iran's power industry. The qualitative research design used in this paper was appropriate for gaining an in-depth understanding how the IPPM capabilities and project context, and certain performance constructs are linked to each other. Our interviews revealed the importance of integrating

  6. Metabolic cost of level-ground walking with a robotic transtibial prosthesis combining push-off power and nonlinear damping behaviors: preliminary results.

    Science.gov (United States)

    Yanggang Feng; Jinying Zhu; Qining Wang

    2016-08-01

    Recent advances in robotic technology are facilitating the development of robotic prostheses. Our previous studies proposed a lightweight robotic transtibial prosthesis with a damping control strategy. To improve the performance of power assistance, in this paper, we redesign the prosthesis and improve the control strategy by supplying extra push-off power. A male transtibial amputee subject volunteered to participate in the study. Preliminary experimental results show that the proposed prosthesis with push-off control improves energy expenditure by a percentage ranged from 9.72 % to 14.99 % for level-ground walking compared with the one using non-push-off control.

  7. Natural radioactivity of ground waters and soil in the vicinity of the ash repository of the coal-fired power plant. Nikola Tesla A in Obrenovac, Yugoslavia

    Energy Technology Data Exchange (ETDEWEB)

    Vukovic, Z.; Madic, M.; Vukovic, D. [Institute of Nuclear Sciences Vinca, Belgrade (Yugoslavia)

    1996-11-01

    Radioactivity of U, Th and {sup 40}K has been investigated in the vicinity of the ash repository of coal-fired Nikola Tesla A power plant in Obrenovac (Yugoslavia). Using alpha and gamma spectrometry, luminescence spectrophotometry, it was found that the ash repository is a source of radionuclides of the uranium and thorium series; and these radionuclides were found in the ground water up to a distance of several hundred metres. The influence of the repository on the soil radioactivity was minimal.

  8. Low Power and Low Ground Bouncing Noise Nanometer CMOS Full Adder%低功耗低电源线噪声纳米CMOS全加器

    Institute of Scientific and Technical Information of China (English)

    田曦; 乔飞; 董在望

    2012-01-01

    A low power and low ground bouncing noise nanometer CMOS full adder is presented. The full adder with power gating structure is used to reduce leakage power consumption. The sum generator circuit of complementary CMOS full adder is modified and the transistor counts are reduced. Sizing of the sleep transistor and the transistors for the full adder is done. The proposed full adder is simulated using 45nm CMOS technology and the simulation results demonstrate better improvements in average power -delay product, leakage power consumption and grounding bouncing noise.%提出一种低功耗低电源线噪声的纳米CMOS全加器.采用电源门控结构的全加器来降低纳米CMOS电路的漏电功耗,改进了传统互补CMOS全加器的求和电路,减少了所需晶体管的数目,并进一步对休眠晶体管的尺寸和全加器的晶体管尺寸进行了联合优化.用Hspice在45nmCMOS工艺下的电路仿真结果表明,改进后的全加器电路在平均功耗时延积、漏电功耗和电源线噪声等方面取得了很好的效果.

  9. Effect of Niagara power project on ground-water flow in the upper part of the Lockport Dolomite, Niagara Falls area, New York

    Science.gov (United States)

    Miller, Todd S.; Kappel, W.M.

    1987-01-01

    The Niagara River Power Project near Niagara Falls, N.Y., has created recharge and discharge areas that have modified the direction of groundwater flow east and northeast of the falls. Before construction of the power project in 1962, the configuration of the potentiometric surface in the upper part of the Silurian Lockport Dolomite generally paralleled the buried upper surface of the bedrock. Ground water in the central and east parts of the city of Niagara Falls flowed south and southwestward toward the upper Niagara River (above the falls), and ground water in the western part flowed westward into Niagara River gorge. The power project consists of two hydroelectric powerplants separated by a forebay canal that receives water from the upper Niagara River through two 4-mi-long, parallel, buried conduits. During periods of nonpeak power demand, some water in the forebay canal is pumped to a storage reservoir for later release to generate electricity during peak-demand periods. Since the power project began operation in 1962, groundwater within 0.5 mi of the buried conduits has seeped into the drain system that surrounds the conduits, then flows both south from the forebay canal and north from the Niagara River toward the Falls Street tunnel--a former sewer that crosses the conduits 0.65 mi north of the upper Niagara River. Approximately 6 million gallons of ground water a day leaks into the Falls Street tunnel, which carries it 2.3 mi westward to the Niagara River gorge below the falls. Daily water-level fluctuations in the forebay canal affect water levels in the drain system that surrounds the conduits, and this , in turn, affects the potentiometric surface in the Lockport Dolomite within 0.5 mi of the conduits. The drains transmit changes in pressure head near the forebay canal southward at least as far as the Falls Street tunnel area and possibly to the upper Niagara River. Some water in the pumped-storage reservoir recharges ground water in the Lockport

  10. Radioisotope Power System Delivery, Ground Support and Nuclear Safety Implementation: Use of the Multi-Mission Radioisotope Thermoelectric Generator for the NASA's Mars Science Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    S.G. Johnson; K.L. Lively; C.C. Dwight

    2014-07-01

    Radioisotope power systems have been used for over 50 years to enable missions in remote or hostile environments. They are a convenient means of supplying a few milliwatts up to a few hundred watts of useable, long-term electrical power. With regard to use of a radioisotope power system, the transportation, ground support and implementation of nuclear safety protocols in the field is a complex process that requires clear identification of needed technical and regulatory requirements. The appropriate care must be taken to provide high quality treatment of the item to be moved so it arrives in a condition to fulfill its missions in space. Similarly it must be transported and managed in a manner compliant with requirements for shipment and handling of special nuclear material. This presentation describes transportation, ground support operations and implementation of nuclear safety and security protocols for a radioisotope power system using recent experience involving the Multi-Mission Radioisotope Thermoelectric Generator for National Aeronautics and Space Administration’s Mars Science Laboratory, which launched in November of 2011.

  11. 基于LabVIEW的飞机地面电源监控系统设计与实现%Design and implementation of aircraft ground power supply monitoring system based on LabVIEW

    Institute of Scientific and Technical Information of China (English)

    程绪刚; 邱智; 郝世勇

    2015-01-01

    Since the complex situation and different electricity demands of aircraft from ground power supply,the ground power supply system is affected. Traditional instruments couldn’t monitor the whole working process of ground power supply,to ensure high power quality and stable performance of the ground power supply,the aircraft ground power supply monitoring system based on LabVIEW software is designed. The ground power supply is monitored and recorded in real⁃time by the parameters of voltage,frequency,harmonic content and so on,the status of ground power supply is judged with reference standard,an effec⁃tive method is provided to maintain normal operation of the ground power supply and ensure the safety electricity of the aircraft.%当地面电源向飞机供电时,由于情况复杂及飞机的用电需求各不相同,从而对地面电源产生影响。传统的仪器仪表不能监测地面电源工作时的整个过程,为保证地面电源有较高的供电品质和稳定的性能,基于LabVIEW软件设计飞机地面电源监控系统。从电压、频率、谐波含量等多个方面对地面电源进行实时监控并记录,参照一定的标准,对地面电源的状态进行判断,为维护地面电源的正常工作及保证飞机的用电安全提供了更有效的方法。

  12. The significance of ground water and soil water conditions on inflow and power situation; Betydning av grunnvann- og markvannsforhold for tilsig og kraftsituasjon

    Energy Technology Data Exchange (ETDEWEB)

    Colleuille, Herve; Holmqvist, V.; Beldring, S.; Haugen, L.E.

    2008-05-15

    The inflow to water reservoirs in the spring can be much smaller than anticipated based on the measured amounts of snow, and in the summer the inflow may be smaller than the rainfall would normally indicate. The goal of this report is to evaluate the significance of ground water and subsoil water for the inflow and the power situation. The first part of the report gives a short description of the methods that are used in this task. The data acquired through the national monitoring network for ground water and soil water is the basis for all analysis and for the method development. Two different tools for making models were utilized in this project: the conceptual and distributed HBV model and the physically based water- and energy balance COUP-model. The Hydrologic department is developing an analyzing and forecasting tool to follow up, analyze and forecast ground water and soil water conditions. This analysis tool is described in this report. The method for converting water balance parameters for soil water deficit to energy content is also presented. The fourth part of the report illustrates the significance of ground water and soil water on afflux and power situation in the dry years of 1995/96, 2002/2003 and 2006. The utilitarian value of combining results from observations through HBV and COUP-simulations to analyze the extreme hydrological conditions is presented in this report. COUP-simulations can be used to improve the estimated inflow at the snow melt or based on the estimated precipitation. (TM) 35 refs., 1 tab., 56 figs

  13. Future Performance of Ground-Based and Airborne Water-Vapor Differential Absorption Lidar. II. Simulations of the Precision of a Near-Infrared, High-Power System.

    Science.gov (United States)

    Wulfmeyer, V; Walther, C

    2001-10-20

    Taking into account Poisson, background, amplifier, and speckle noise, we can simulate the precision of water-vapor measurements by using a 10-W average-power differential absorption lidar (DIAL) system. This system is currently under development at Hohenheim University, Germany, and at the American National Center for Atmospheric Research. For operation in the 940-nm region, a large set of measurement situations is described, including configurations that are considered for the first time to the authors' knowledge. They include ultrahigh-resolution measurements in the surface layer (resolutions, 1.5 m and 0.1 s) and vertically pointing measurements (resolutions, 30 m and 1 s) from the ground to 2 km in the atmospheric boundary layer. Even during daytime, the DIAL system will have a measurement range from the ground to the upper troposphere (300 m, 10 min) that can be extended from a mountain site to the lower stratosphere. From the ground, for the first time of which the authors are aware, three-dimensional fields of water vapor in the boundary layer can be investigated within a range of the order of 15 km and with an averaging time of 10 min. From an aircraft, measurements of the atmospheric boundary layer (60 m, 1 s) can be performed from a height of 4 km to the ground. At higher altitudes, up to 18 km, water-vapor profiles can still be obtained from aircraft height level to the ground. When it is being flown either in the free troposphere or in the stratosphere, the system will measure horizontal water-vapor profiles up to 12 km. We are not aware of another remote-sensing technique that provides, simultaneously, such high resolution and accuracy.

  14. Experimental studies of the characteristics of solar-power-plant heliostats on a proving ground - The fixed-heliostat method

    Science.gov (United States)

    Tepliakov, D. I.; Aparisi, R. R.

    The specific features of a new method for investigating the energy characteristics of heliostats for a tower-type solar plant are examined. The method consists in fixing a heliostat in a certain position in the case of which the spot formed by reflected solar radiation due to the apparent motion of the sun is displaced on the surface of an instrumented screen. Midday experiments on a meridional proving ground are discussed, and the practical implementation of the fixed-heliostat method is described.

  15. Regression relationships of landing height with ground reaction forces, knee flexion angles, angular velocities and joint powers during double-leg landing.

    Science.gov (United States)

    Yeow, C H; Lee, Peter V S; Goh, James C H

    2009-10-01

    Ground reaction forces (GRF), knee flexion angles, angular velocities and joint powers are unknown at large landing heights, which are infeasible for laboratory testing. However, this information is important for understanding lower extremity injury mechanisms. We sought to determine regression relationships of landing height with these parameters during landing so as to facilitate estimation of these parameters at large landing heights. Five healthy male subjects performed landing tasks from heights of 0.15-1.05 m onto a force-plate. Motion capture system was used to obtain knee flexion angles during landing via passive markers placed on the lower body. An iterative regression model, involving simple linear/exponential/natural logarithmic functions, was used to fit regression equations to experimental data. Peak GRF followed an exponential regression relationship (R(2)=0.90-0.99, p<0.001; power=0.987-0.998). Peak GRF slope and impulse also had an exponential relationship (R(2)=0.90-0.96, p<0.001; power=0.980-0.997 and R(2)=0.90-0.99, p<0.001; power=0.990-1.000 respectively) with landing height. Knee flexion angle at initial contact and at peak GRF had an inverse-exponential regression relationship (R(2)=0.81-0.99, p<0.001-p=0.006; power=0.834-0.978 and R(2)=0.84-0.97, p<0.001-p=0.004; power=0.873-0.999 respectively). There was also an inverse-exponential relationship between peak knee flexion angular velocity and landing height (R(2)=0.86-0.96, p<0.001; power=0.935-0.994). Peak knee joint power demonstrated a substantial linear relationship (R(2)=0.98-1.00, p<0.001; power=0.990-1.000). The parameters analyzed in this study are highly dependent on landing height. The exponential increase in peak GRF parameters and the relatively slower increase in knee flexion angles, angular velocities and joint power may synergistically lead to an exacerbated lower extremity injury risk at large landing heights.

  16. Employees’ Involuntary Non-Use of ICT Influenced by Power Differences: A Case Study with the Grounded Theory Approach

    Directory of Open Access Journals (Sweden)

    Thale Kvernberg Andersen

    2015-07-01

    Full Text Available Power differences affect implementation of information and communication technology (ICT in a way that creates differences in ICT use. Involuntary non-use of new ICT at work occurs when employees want to use the new technology, but are unable to due to factors beyond their control. Findings from an in-depth qualitative study show how involuntary non-use of new ICT can be attributed to power differences between occupational groups in the same organization. The findings suggest that experience is a moderating variable and that closeness to formal power holders as well as closeness to the new technology increases the probability for expert control of the ICT-organization processes. These power differences favor ICT experts over ICT novices and result in a high-quality learning environment for the ICT experts characterized by autonomy, inclusion, and adequate work processes and technological solutions. The ICT novices try to navigate in a learning-hostile work environment characterized by marginalization through expert control, isolation, and inadequate work processes and technological solutions. This led to involuntary non-use by the ICT novices, while the experts became more proficient in ICT use. These findings give managers facing a technological organizational change tools to understand important mechanisms for implementing the change in their own organization, and help them take the right actions to integrate new technology and new organization of work.

  17. Power

    DEFF Research Database (Denmark)

    Elmholdt, Claus Westergård; Fogsgaard, Morten

    2016-01-01

    In this chapter, we will explore the dynamics of power in processes of creativity, and show its paradoxical nature as both a bridge and a barrier to creativity in organisations. Recent social psychological experimental research (Slighte, de Dreu & Nijstad, 2011) on the relation between power...... and creativity suggests that when managers give people the opportunity to gain power and explicate that there is reason to be more creative, people will show a boost in creative behaviour. Moreover, this process works best in unstable power hierarchies, which implies that power is treated as a negotiable...... and floating source for empowering people in the organisation. We will explore and discuss here the potentials, challenges and pitfalls of power in relation to creativity in the life of organisations today. The aim is to demonstrate that power struggles may be utilised as constructive sources of creativity...

  18. Ground based observations of Pc3-Pc5 geomagnetic pulsation power at Antarctic McMurdo station

    Directory of Open Access Journals (Sweden)

    C. G. Maclennan

    1998-06-01

    Full Text Available The two horizontal geomagnetic components and, measured by a fluxgate magnetometer at Antarctic McMurdo station (corrected geomagnetic coordinates 80.0° S, 327.5° E, are analyzed for the period May-June 1994; the spectral powers are calculated and integrated over three frequency intervals corresponding to the nominal ranges. The time dependence of those integrated powers and their correlations with northern auroral indices and solar wind speed are considered. The observations are compared with previous results reported from Terra Nova Bay station (located near McMurdo at the same corrected geomagnetic latitude during Antarctic summer intervals. The differences found between the two stations are discussed in terms of the seasonal dependence of geomagnetic field line configurations in the near cusp region.

  19. Kilowatt Isotope Power System: component test report for the ground demonstration system jet condenser orifice performance. 77-KIPS-103

    Energy Technology Data Exchange (ETDEWEB)

    Brainard, E.L.

    1977-11-08

    The purpose of these tests was to determine which orifice elements achieved satisfactory hydraulic and thermal performance prior to their incorporation into the Jet Condenser Assembly. Requirements were as set forth within the Kilowatt Isotope Power System (KIPS) Component Test Procedure number 414 for the Jet Condenser Orifice Performance testing. The results of the performance testing conducted on the Jet Condenser Orifices are presented. Part Number 720841 Jet Condenser Orifice Nozzle successfully completed the orifice screening tests.

  20. An economic analysis of space solar power and its cost competitiveness as a supplemental source of energy for space and ground markets

    Science.gov (United States)

    Marzwell, N. I.

    2002-01-01

    Economic Growth has been historically associated with nations that first made use of each new energy source. There is no doubt that Solar Power Satellites is high as a potential energy system for the future. A conceptual cost model of the economics value of space solar power (SSP) as a source of complementary power for in-space and ground applications will be discussed. Several financial analysis will be offered based on present and new technological innovations that may compete with or be complementary to present energy market suppliers depending on various institutional arrangements for government and the private sector in a Global Economy. Any of the systems based on fossil fuels such as coal, oil, natural gas, and synthetic fuels share the problem of being finite resources and are subject to ever-increasing cost as they grow ever more scarce with drastic increase in world population. Increasing world population and requirements from emerging underdeveloped countries will also increase overall demand. This paper would compare the future value of SSP with that of other terrestrial renewable energy in distinct geographic markets within the US, in developing countries, Europe, Asia, and Eastern Europe.

  1. Design of Digital Variable Frequency Power for Grounding Resistance Measurement%地网测量仪用数字变频电源设计

    Institute of Scientific and Technical Information of China (English)

    余为清

    2013-01-01

      利用SPCE061A单片机的片上资源,根据SPWM原理,以高级语言生成波形数据表格,以查表调用的方式提高了变频电源频率合成的速度和精度。电源具有较高的效率,实测表明该电源波形质量好,适合在地网接地电阻测量中应用。%Based on the principle of SPWM,this paper discusses how to improve the rate and precision of fre-quency synthesis of variable-frequency power supply by utilizing resources on the chip of SPCE061A and gen-erating waveform data form with advanced language and in lookup-calling form . The experimental results show that the power has high efficiency with good power waveform,which is suitable for grounding resistance measurement.

  2. Solar radiation concentrators paired with multijunction photoelectric converters in ground-based solar power plants (part I)

    Science.gov (United States)

    Ionova, E. A.; Ulanov, M. V.; Davidyuk, N. Yu.; Sadchikov, N. A.

    2016-12-01

    We have developed a method for determining parameters of radiation concentrator in solar power plants. To estimate the efficiency of concentrators in the form of Fresnel lenses in setups with three-junction photoelectric converters, the concept of the efficiency of the concentrator-photoelectric converter pair has been introduced. We have proposed a method for calculating the refracting profile of concentrators taking into account the dispersion relation for the refractive index and its variations with temperature for the material of the refracting profile of the concentrator (Wacker RT604 silicone compound). The results of calculation make it possible to achieve the maximal efficiency of the concentrator-photoelectric converter pair in the presence of chromatic aberrations in the optical system of solar radiation concentration.

  3. Self-healing of single-phase grounding fault for power distribution lines%配电线路单相接地故障自愈方案

    Institute of Scientific and Technical Information of China (English)

    施慎行; 董新洲; 吴家华; 沈冬

    2012-01-01

    A self-healing scheme is presented for the single-phase grounding fault of distribution lines,which consists of four parts:fault detection, faulty feeder selection, faulty section identification and faulty feeder isolation. The fault detection is based on the open-delta-side voltages of PT. A single-phase grounding fault is identified when the measured voltage is greater than the setting value. The faulty feeder selection is based on the current traveling waves. The feeder with different traveling wave polarity is selected as the faulty one. The faulty section identification is based on the synthesized results of faulty feeder selection. After the faulty feeder is selected,close the interconnection switch at the load side first,then open its incoming switch and isolate the power source side of faulty. Simulative results show that the scheme realizes the automatic quick isolation of single-phase grounding fault without power loss of load.%针对配电线路的单相接地故障,提出了故障自愈方案.方案包括单相接地故障检测、故障选线、故障区段识别和接地线路隔离4个部分.故障检测基于母线上的电压互感器开口三角侧电压,当测量电压大于整定值时,判断系统中发生了单相接地故障;故障选线基于线路上的电流行波,极性与众不同的电流行波所在线路为接地线路;故障区段识别基于故障选线的综合结果;选出故障母线后,先闭合接地线路负荷侧的联络开关,再打开接地线路负荷侧进线开关,最后隔离接地线路电源侧.仿真结果表明,所提自愈方案可实现单相接地故障自动快速隔离,故障隔离过程中负荷不失电.

  4. Simulation Analysis on Power Frequency Electric Field at Ground Surface Near EHV Power Transmission Tower%超高压输电线路铁塔附近地面工频电场仿真分析

    Institute of Scientific and Technical Information of China (English)

    李永明; 范与舟; 徐禄文

    2013-01-01

    根据铁塔实际结构和导线抛物线方程,建立了铁塔附近三维电场计算模型.基于模拟电荷法分析了500 kV输电线路铁塔周围地面上的工频电场分布,分析了铁塔对其附近电场环境的影响,并讨论了影响电场计算结果的因素.研究结果表明:铁塔对其附近地面电场有一定屏蔽作用,电场强度在铁塔下方显著降低且在金属构架处产生畸变;铁塔的影响范围和铁塔高度及塔基尺寸有关;铁塔构架等效半径、线单元剖分段数以及铁塔不同简化模型都会影响计算结果.%Based on actual structure of power transmission tower and parabolic equation of transmission lines,a three-dimensional model to compute power frequency electric field at ground surface near transmission tower is built.According to charge simulation method,the distribution of power frequency electric field at ground surface near 500kV transmission tower as well as the impacts of transmission tower on nearby electric field is analyzed,and the factors impacting computational results of electric field are discussed.Research results show that there is a certain screening effect of transmission tower on ground surface electric field nearby the tower,so the electric field intensity beneath the tower decreases obviously and electric field distortion appears at the positions where metal frameworks are erected.The impacting area is related to the height of the tower and the size of tower foundation; computational result of electric field will be impacted by the equivalent radius of tower framework,the number of line segments and different simplified models of the tower.

  5. A low-power low-error single-ended virtually-grounded-drain class AB switched-current memory cell

    Directory of Open Access Journals (Sweden)

    Banlue Srisuchinwong

    2007-01-01

    Full Text Available A low-power low-error single-ended virtually-grounded-drain class AB switched-current memory cell is presented. The proposed circuit is relatively simple, based on a basic class AB SI memory cell and a levelshiftedgrounded-gate amplifier. No large differential circuitry and complicated clocking schemes are required. All charge-injection, clock-feedthrough and conduction errors are reduced. As a design exampleusing 0.5-μm CMOS technology, the power consumption is 120 μW at the bias current of 25 μA and supply voltage of 2V. The optimal sampling frequency is at 45MHz. The SNR, SDR and SFDR are 59.7 dB, 61 dB and73 dB, respectively. The total harmonic distortion is less than 0.4%. The transmission gain error and the DC offset current error are less than 0.025 and 0.75 μA, respectively. Demonstrations of a forward differenceintegrator and comparisons to other approaches are also presented.

  6. Transient Analysis of Dispersive Power-Ground Plate Pairs With Arbitrarily Shaped Antipads by the DGTD Method With Wave Port Excitation

    KAUST Repository

    Li, Ping

    2016-09-09

    A discontinuous Galerkin time-domain (DGTD) method analyzing signal/power integrity on multilayered power-ground parallel plate pairs is proposed. The excitation is realized by introducing wave ports on the antipads where electric/magnetic current sources are represented in terms of the eigenmodes of the antipads. Since closed-forms solutions do not exist for the eigenmodes of the arbitrarily shaped antipads, they have to be calculated using numerical schemes. Spatial orthogonality of the eigenmodes permits determination of each mode\\'s temporal expansion coefficient by integrating the product of the electric field and the mode over the wave port. The temporal mode coefficients are then Fourier transformed to accurately calculate the S-parameters corresponding to different modes. Additionally, to generalize the DGTD to manipulate dispersive media, the auxiliary differential equation method is employed. This is done by introducing a time-dependent polarization volume current as an auxiliary unknown and the constitutive relation between this current and the electric field as an auxiliary equation. Consequently, computationally expensive temporal convolution is avoided. Various numerical examples, which demonstrate the applicability, robustness, and accuracy of the proposed method, are presented.

  7. 关于PCB电磁兼容设计中的电源和接地探讨%Discussion on power supply and grounding in EMC design of PCB

    Institute of Scientific and Technical Information of China (English)

    李双力

    2016-01-01

    This paper from the power and grounding in EMC interference of,electromagnetic compatibility design countermeasures explores the,hope for PCB electromagnetic compatible design of power supply and grounding work provides positive reference and suggestions.%本文从电源和接地在电磁兼容中的干扰出发,对电磁兼容设计的处理对策进行了探究,希望为PCB电磁兼容设计中的电源和接地工作提供积极借鉴和建议。

  8. Dissecting the Power Sources of Low-Luminosity Emission-Line Galaxy Nuclei via Comparison of HST-STIS and Ground-Based Spectra

    Science.gov (United States)

    Constantin, Anca; Shields, Joseph C.; Ho, Luis C.; Barth, Aaron J.; Filippenko, Alexei V.; Castillo, Christopher A.

    2015-12-01

    Using a sample of ∼100 nearby line-emitting galaxy nuclei, we have built the currently definitive atlas of spectroscopic measurements of Hα and neighboring emission lines at subarcsecond scales. We employ these data in a quantitative comparison of the nebular emission in Hubble Space Telescope (HST) and ground-based apertures, which offer an order-of-magnitude difference in contrast, and provide new statistical constraints on the degree to which transition objects and low-ionization nuclear emission-line regions (LINERs) are powered by an accreting black hole at ≲10 pc. We show that while the small-aperture observations clearly resolve the nebular emission, the aperture dependence in the line ratios is generally weak, and this can be explained by gradients in the density of the line-emitting gas: the higher densities in the more nuclear regions potentially flatten the excitation gradients, suppressing the forbidden emission. The transition objects show a threefold increase in the incidence of broad Hα emission in the high-resolution data, as well as the strongest density gradients, supporting the composite model for these systems as accreting sources surrounded by star-forming activity. The narrow-line LINERs appear to be the weaker counterparts of the Type 1 LINERs, where the low accretion rates cause the disappearance of the broad-line component. The enhanced sensitivity of the HST observations reveals a 30% increase in the incidence of accretion-powered systems at z ≈ 0. A comparison of the strength of the broad-line emission detected at different epochs implies potential broad-line variability on a decade-long timescale, with at least a factor of three in amplitude. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the data archive at the Space Telescope Science Institute. STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

  9. DISSECTING THE POWER SOURCES OF LOW-LUMINOSITY EMISSION-LINE GALAXY NUCLEI VIA COMPARISON OF HST-STIS AND GROUND-BASED SPECTRA

    Energy Technology Data Exchange (ETDEWEB)

    Constantin, Anca; Castillo, Christopher A. [Department of Physics and Astronomy, James Madison University, Harrisonburg, VA 22807 (United States); Shields, Joseph C. [Department of Physics and Astronomy, Ohio University, Athens, OH 45701 (United States); Ho, Luis C. [Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871 (China); Barth, Aaron J. [Department of Physics and Astronomy, University of California, Irvine, CA 92697-4575 (United States); Filippenko, Alexei V. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States)

    2015-12-01

    Using a sample of ∼100 nearby line-emitting galaxy nuclei, we have built the currently definitive atlas of spectroscopic measurements of Hα and neighboring emission lines at subarcsecond scales. We employ these data in a quantitative comparison of the nebular emission in Hubble Space Telescope (HST) and ground-based apertures, which offer an order-of-magnitude difference in contrast, and provide new statistical constraints on the degree to which transition objects and low-ionization nuclear emission-line regions (LINERs) are powered by an accreting black hole at ≲10 pc. We show that while the small-aperture observations clearly resolve the nebular emission, the aperture dependence in the line ratios is generally weak, and this can be explained by gradients in the density of the line-emitting gas: the higher densities in the more nuclear regions potentially flatten the excitation gradients, suppressing the forbidden emission. The transition objects show a threefold increase in the incidence of broad Hα emission in the high-resolution data, as well as the strongest density gradients, supporting the composite model for these systems as accreting sources surrounded by star-forming activity. The narrow-line LINERs appear to be the weaker counterparts of the Type 1 LINERs, where the low accretion rates cause the disappearance of the broad-line component. The enhanced sensitivity of the HST observations reveals a 30% increase in the incidence of accretion-powered systems at z ≈ 0. A comparison of the strength of the broad-line emission detected at different epochs implies potential broad-line variability on a decade-long timescale, with at least a factor of three in amplitude.

  10. Spatial distributions of radionuclides deposited onto ground soil around the Fukushima Dai-ichi Nuclear Power Plant and their temporal change until December 2012.

    Science.gov (United States)

    Mikami, Satoshi; Maeyama, Takeshi; Hoshide, Yoshifumi; Sakamoto, Ryuichi; Sato, Shoji; Okuda, Naotoshi; Demongeot, Stéphanie; Gurriaran, Rodolfo; Uwamino, Yoshitomo; Kato, Hiroaki; Fujiwara, Mamoru; Sato, Tetsuro; Takemiya, Hiroshi; Saito, Kimiaki

    2015-01-01

    Spatial distributions and temporal changes of radioactive fallout released by the Fukushima Dai-ichi Nuclear Power Plant accident have been investigated by two campaigns with three measurement schedules. The inventories (activities per unit area) of the radionuclides deposited onto ground soil were measured using portable gamma-ray spectrometers at nearly 1000 locations (at most) per measurement campaign. Distribution maps of the inventories of (134)Cs, (137)Cs, and (110m)Ag as of March, September, and December 2012 were constructed. No apparent temporal change of the radionuclide inventories was observed from March to December 2012. Weathering effects (e.g., horizontal mobility) were not noticeable during this period. Spatial dependence in the ratios of (134)Cs/(137)Cs and (110m)Ag/(137)Cs were observed in the Tohoku and Kanto regions. The detailed maps of (134)Cs and (137)Cs as of September 2012 and December 2012 were constructed using the relationship between the air dose rate and the inventory.

  11. Site-Specific PSHA for Nuclear Power Plants in France: Variability of the Predicted Ground Motion Quantified with a Logic Tree and Monte Carlo Approach

    Science.gov (United States)

    Clément, C.; Baize, S.; Beauval, C.; Bonilla, L. F.; Scotti, O.

    2003-04-01

    The current French Nuclear Regulation for the evaluation of seismic hazard is deterministic. Nevertheless, in order to provide results to an ongoing Probabilistic Safety Assessment study that is being carried out at IRSN, we are developing a site-specific Probabilistic Seismic Hazard Assessment (PSHA) for nuclear power plants in France. The methodology proposed in this study combines a logic tree structure with a Monte Carlo exploration. This allows an exhaustive quantification of the impact on the hazard level due to both epistemic and random uncertainties. The region of interest for this study is the South East of France where the knowledge of the seismic potential of the known structures is sparse. We explore uncertainties inherent in seismicity catalogues, source models, attenuation laws and definitions of the seismic source geometries. In particular we focus on fault sources for which we propose numerous scenarios that consider rupture on single and multiple segments. The purpose of the methodology developed in the framework of this study is to 1) calculate seismic hazard with probabilities as low as 10-7 2) quantify the variability of the hazard level 3) identify the most probable scenarios and compute the associated ground motions at the site of interest.

  12. Dissecting the Power Sources of Low-Luminosity Emission-Line Galaxy Nuclei via Comparison of HST-STIS and Ground-Based Spectra

    CERN Document Server

    Constantin, Anca; Ho, Luis C; Barth, Aaron J; Filippenko, Alexei V; Castillo, Christopher A

    2015-01-01

    Using a sample of ~100 nearby line-emitting galaxy nuclei, we have built the currently definitive atlas of spectroscopic measurements of H_alpha and neighboring emission lines at subarcsecond scales. We employ these data in a quantitative comparison of the nebular emission in Hubble Space Telescope (HST) and ground-based apertures, which offer an order-of-magnitude difference in contrast, and provide new statistical constraints on the degree to which Transition Objects and low-ionization nuclear emission-line regions (LINERs) are powered by an accreting black hole at <10 pc. We show that while the small-aperture observations clearly resolve the nebular emission, the aperture dependence in the line ratios is generally weak, and this can be explained by gradients in the density of the line-emitting gas: the higher densities in the more nuclear regions potentially flatten the excitation gradients, suppressing the forbidden emission. The Transition Objects show a threefold increase in the incidence of broad H_...

  13. Analysis on Protection of Power System Grounding and Meeting Cipher%浅析电力系统中接地和接零保护

    Institute of Scientific and Technical Information of China (English)

    汶占武

    2011-01-01

    In the electrical power supply and distribution system, electrical equipment insulation to reduce aging, voltage breakdown, external injury and other causes all possibly cause the uncharged equipments be in charged, such as, metal foundation, metal outer covering of the equipment, the metal frame and so on. In order to avoid the damage of electrical equipment caused by charged equipment and casualty accident, we usually adopt the measure of protecting grounding and meeting zero.%在低压供配电系统中,电气装置绝缘降低老化、因过电压击穿、外力损伤等原因,都可能使设备金属底座、设备金属外壳,金属框架等正常情况不带电的部分带电,为了防止设备意外带电引起电气设各损坏和人身触电伤亡事故,通常采取保护接地和保护接零的措施进行保护.

  14. 46 CFR 120.376 - Grounded distribution systems (Neutral grounded).

    Science.gov (United States)

    2010-10-01

    ... ELECTRICAL INSTALLATION Power Sources and Distribution Systems § 120.376 Grounded distribution systems... distribution system having a neutral bus or conductor must have the neutral grounded. (c) The neutral or each... generator is connected to the bus, except the neutral of an emergency power generation system must...

  15. Analysis of Low-Resistance Neutral Point Grounding Mode in 10kV Power Distribution Grid%10 kV配电网中性点经小电阻接地方式分析

    Institute of Scientific and Technical Information of China (English)

    顾韧; 闫少波

    2015-01-01

    Introduction was made to the low-resistance neutral point grounding mode in 10kV power distribution grid. Analysis was made to the current direction and protection setting mode when the line single phase grounding. This paper discussed a case of total reserve unwanted operation of grounding transformer when the line high-resistance grounding and suggested that the line should fit for the setting value of grounding transformer zero-sequence current. The result shows that in the low-resistance neutral point ground-ing system, if the setting value of grounding transformer zero-sequence current acting as the 10kV system total reserve is less than that of the outgoing line secondary section, the total reserve will turn up unwanted operation.%介绍了10kV配电网中性点经小电阻接地方式,通过对线路单相接地时的电流流向和保护整定方式的分析,讨论了一起线路高阻接地时接地变总后备误动的案例,并对线路和接地变零序电流整定值的配合方式给出了建议。结果表明,中性点经小电阻接地系统中,若作为整个10 kV系统总后备的接地变高压零流整定值小于出线Ⅱ段零序整定值,可能会造成总后备误动作。

  16. Grounded theory.

    Science.gov (United States)

    Harris, Tina

    2015-04-29

    Grounded theory is a popular research approach in health care and the social sciences. This article provides a description of grounded theory methodology and its key components, using examples from published studies to demonstrate practical application. It aims to demystify grounded theory for novice nurse researchers, by explaining what it is, when to use it, why they would want to use it and how to use it. It should enable nurse researchers to decide if grounded theory is an appropriate approach for their research, and to determine the quality of any grounded theory research they read.

  17. Ground failure in direct current systems of the Itaipu Hydroelectric Power Plant, Parana, Brazil. Impact in the operation; Falla a tierra en sistemas de corriente continua en la Central Hidroelectrica Itaipu, PR, Brasil. Impacto en la operacion

    Energy Technology Data Exchange (ETDEWEB)

    Soto Santacruz, Heriberto [Itaipu Binacional, Foz do Iguacu, PR (Brazil)]. E-mail: soto@itaipu.gov.py

    1998-07-01

    The objective of this work is to share with other companies the operation experience obtained by researching the direct current systems ground failure, in the Itaipu Hydroelectric Power Plant. During the research process electrical and/or electronic components can be damaged, and also human failures can occurred during the circuit connection and disconnection manoeuvres, necessary for the identification of the components causing the failures.

  18. 大型游乐设施配电系统接地型式的探讨%Discussion on Grounding Type of Large Rides Power Distribution System

    Institute of Scientific and Technical Information of China (English)

    汤小丽; 何贵阳

    2014-01-01

    This paper analyzed the pros and cons of different grounding types of large rides distribution systems , to determine a suitable way for grounding type of large rides distribution system .%分析不同接地型式的配电系统应用在大型游乐设施的利弊情况,确定适合大型游乐设施配电系统的接地型式。

  19. Research on Grounding Network Construction and Management of Power System%关于电力系统接地网施工与管理的研究

    Institute of Scientific and Technical Information of China (English)

    叶喜太

    2011-01-01

    接地网的用途极其广泛,一般用在工作(系统)接地、保护接地、防雷电和防静电接地等,做好电网接地施工工作并确保接地装置的安全,是一项非常重要的工作,因为它是维护变电站安全可靠运行、保障运行人员和电气设备安全运行的根本保证和重要措施.%The application of grounding network is extremely broad, which is generally used in work (system) grounding, protective grounding,lightning protection and anti-static grounding, doing well grid ground construction work and ensuring the safety grounding device is a very important work, because it is the fundamental guarantee and important measure to maintain safe and reliable operation of substation and guarantee the security of running personnel and electrical equipment operation.

  20. Four-Bit Cmos Full Adder Design in Submicron Technology with Low Leakage Power and Ground Bounce Noise Reduction Using Dual Sleep Approach

    Directory of Open Access Journals (Sweden)

    Jagadeesh Yabaku

    2013-03-01

    Full Text Available In CMOS integrated circuit design there is a trade-off between static power consumption and technology scaling. Leakage power accounts for an increasingly larger portion of total power consumption in deep submicron technologies. Recently, the power density has increased due to combination of higher clock speeds, greater functional integration, and smaller process geometries. As a result static power consumption is becoming more dominant. This is a challenge for the circuit designers. However, the designers do have a few methods which they can use to reduce this static power consumption. But all of these methods have some drawbacks. In order to achieve lower static power consumption, one has to sacrifice design area and circuit performance. In this paper, we propose a new method to reduce static power in the CMOS VLSI circuit using dual stack approach without being penalized in area requirement and circuit performance.

  1. Design and engineering of west-side revetment for Tachibana Bay Power Station. Swelling behavior of sand compaction pile improved ground and mechanical properties of composite ground; Tachibanawan hatsudensho Nishigogan koji no sekkei to seko. Sand compaction pile kairyo jiban no moriagari kyodo to fukugo jiban no rikigaku tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Kameda, S.; Hara, J.; Ozaki, S. [Shikoku Electric Power Co., Inc., Kagawa (Japan)

    1997-07-05

    This report covers a sand compaction pile (SCP) process performed for the improvement of the sea bottom along the west-side revetment of the power station where a 10-odd meter thick sedimentary layer of soft clayey soil exists. Since the sea is only 5m deep in this area, an engineering method is chosen capable of minimizing the swelling of the ground, and changes in the physical properties of the composite ground that may affect the stability of the revetment are investigated. In this report, an estimating equation is proposed for accurately predicting the swelling, including the additional swelling of the ground already swollen, to result from the SCP-assisted improvement of the ground and a description is given of changes in composite ground mechanical properties induced by the SCP-assisted engineering work. A `one-directional construction system with one block constituted of three spans` is contrived. Furthermore, an estimating technique taking into account the secondary swelling is proposed. As the result, the apparent swelling rate agrees very well with the actual swelling rate. An SCP method with its capability enhanced may be established by considering time-dependent changes in the mechanical properties of the clayey soil between piles and their impact on the safety factor. 4 refs., 13 figs., 3 tabs.

  2. Grounded cognition.

    Science.gov (United States)

    Barsalou, Lawrence W

    2008-01-01

    Grounded cognition rejects traditional views that cognition is computation on amodal symbols in a modular system, independent of the brain's modal systems for perception, action, and introspection. Instead, grounded cognition proposes that modal simulations, bodily states, and situated action underlie cognition. Accumulating behavioral and neural evidence supporting this view is reviewed from research on perception, memory, knowledge, language, thought, social cognition, and development. Theories of grounded cognition are also reviewed, as are origins of the area and common misperceptions of it. Theoretical, empirical, and methodological issues are raised whose future treatment is likely to affect the growth and impact of grounded cognition.

  3. 220kV变压器中性点经小电抗接地方式%Neutral Grounding via Small Reactance for 220 kV Power Transformers

    Institute of Scientific and Technical Information of China (English)

    于化鹏; 陈水明; 杨鹏程; 印华; 崔婷

    2011-01-01

    为了限制短路电流和满足继电保护整定的需要,我国220kV电力系统采崩的是部分变压器中性点接地方式.这种接地方式会使不接地变压器的中性点产生过电压,若失地后发生单相接地故障更可能使中性点过电压上升到相电压,虽然可以用避雷器和间隙对此进行保护,但间隙放电分散性很大,很可能误动,且可能会与避雷器绝缘配合失调.为此建立了一个重庆地区的220kV电网,使用PSCAD/EMTDC 软件计算了中性点加装小电抗后的中性点过电压及短路电流.计算结果表明:中性点串接小电抗后,中性点的过电压会大幅下降,不再会出现失地现象,中性点电压也不会再出现高达相电压的过电压,中性点不必再安装间隙,只安装避雷器限制雷电过电压即可,免去了绝缘配合失调的可能性;并且,中性点加装小电抗后,变压器绕组流过的单相短路电流会下降,可以防止变压器绕组上流过的电流过大,损坏变压器.最后分析了中性点加装小电抗对继电保护的影响.%To suppress short-circuit and meet the demand of the setting of protective relaying, only part of neutral points of power transformers of 220 kV power systems in China are grounded, and this grounding mode leads to overvoltage appeared at the neutral points of non-grounded power trensformers. In 220 kV power system adopting such a neutral grounding mode, the neutral overvoltage may rise to phase voltage when single-phase earth fault occurs while the grounding is in failure. Although arrestors and gap can be used to suppress neutral overvoltage, however due to the dispersity of gap discharging the malfunction of the gap may occur and the insulation coordination of gaps with arrestors may disorder.For this reason a model of 220 kV power system in Chongqing area is built and neutral overvoltage and short-circuit current are computed by PSCAD/EMTDC software when the neutral of 220 kV power transformer is

  4. Ground Wars

    DEFF Research Database (Denmark)

    Nielsen, Rasmus Kleis

    Political campaigns today are won or lost in the so-called ground war--the strategic deployment of teams of staffers, volunteers, and paid part-timers who work the phones and canvass block by block, house by house, voter by voter. Ground Wars provides an in-depth ethnographic portrait of two...... infrastructures that utilize large databases with detailed individual-level information for targeting voters, and armies of dedicated volunteers and paid part-timers. Nielsen challenges the notion that political communication in America must be tightly scripted, controlled, and conducted by a select coterie...... of professionals. Yet he also quashes the romantic idea that canvassing is a purer form of grassroots politics. In today's political ground wars, Nielsen demonstrates, even the most ordinary-seeming volunteer knocking at your door is backed up by high-tech targeting technologies and party expertise. Ground Wars...

  5. 塔式太阳能电站聚光镜场的土地利用率研究%Study on ground coverage of heliostats field in central receiver solar power plant

    Institute of Scientific and Technical Information of China (English)

    丁婷婷; 祝雪妹

    2012-01-01

    Most conventional heliostats field consist of rectangular heliostats, which have regular arrangement in central receiver solar power plant. The maximum ground coverage possible of such heliostats field without colliding neighboring reflectors is 58%. In this paper, a regular and radial arrangement of heliostats field is presented, a ground coverage model of different shape reflectors is carried out, and calculates different ground coverage in different situations. The simulation results show that a maximum ground coverage will obtain when width -height ratio of rectangular reflectors and hexagonal reflectors meet necessary condition. With die shape of hexagonal reflectors ground coverage is up to 100%.%塔式太阳能热发电站的聚光镜场大多是由按一定规律排列的矩形定日镜组成,在相邻定日镜间无机械碰撞的情况下,聚光镜场的最大土地利用率仅为58%.文章提出了选用规则交错排列的聚光镜场布置方案,建立不同形状定日镜的土地利用模型,并计算出不同情况下的最大土地利用率.通过仿真得出,矩形定日镜和六边形定日镜在一定长宽比时可获得最大土地利用率,其中六边形定日镜的土地利用率最高,约为100%.

  6. Analysis and Compact Modeling of a Vertical Grounded-Base NPN Bipolar Transistor used as ESD Protection in a Smart Power Technology

    OpenAIRE

    Bertrand, Géraldine; Delage, Christelle; Bafleur, Marise; Nolhier, Nicolas; Dorkel, Jean-Marie; Nguyen, Quang; Mauran, Nicolas; Trémouilles, David; Perdu, Philippe

    2001-01-01

    9 pages; International audience; A thorough analysis of the physical mechanisms involved in a Vertical Grounded-Base NPN bipolar transistor (VGBNPN) under ElectroStatic Discharge (ESD) stress is first carried out by using 2D-device simulation, Transmission Line Pulse measurement (TLP) and photoemission experiments. This analysis is used to account for the unexpected low value of the VGBNPN snapback holding voltage under TLP stress. A compact model based on a new avalanche formulation resultin...

  7. Analysis of the strong motion records obtained from the 2007 Niigataken Chuetsuoki earthquake and determination of the design basis ground motions at the Kashiwazaki Kariwa Nuclear Power Plant. Part 1. Outline of the strong motion records and estimation of factors in large amplification

    Energy Technology Data Exchange (ETDEWEB)

    Tokumitsu, Ryoichi; Kikuchi, Masatomo; Nishimura, Isao (Nuclear Asset Management Dept., Tokyo Electric Power Company, Tokyo (Japan)), e-mail: tokumitsu.r@tepco.co.jp; Shiba, Yoshiaki (Earthquake Engineering Sector, Central Research Inst. of Electric Power Industry, Chiba (Japan)), e-mail: cbar@criepi.denken.or.jp; Tanaka, Shinya (Architectural Dept., Tokyo Electric Power Services CO., LTD.,Tokyo (Japan)), e-mail: s.tanaka@tepsco.co.jp

    2009-07-01

    In order to investigate the primary factor of the large ground motion observed at the Kashiwazaki Kariwa Nuclear Power Plant in the Niigataken Chuetsu-Oki Earthquake, the source, propagation and site effect of the Niigataken Chuetsu-Oki Earthquake, with the analysis and ground motion simulation analysis of observation record was examined

  8. Differences in rates of decrease of environmental radiation dose rates by ground surface property in Fukushima City after the Fukushima Daiichi nuclear power plant accident.

    Science.gov (United States)

    Kakamu, Takeyasu; Kanda, Hideyuki; Tsuji, Masayoshi; Kobayashi, Daisuke; Miyake, Masao; Hayakawa, Takehito; Katsuda, Shin-ichiro; Mori, Yayoi; Okouchi, Toshiyasu; Hazama, Akihiro; Fukushima, Tetsuhito

    2013-01-01

    After the Great East Japan Earthquake on 11 March 2011, the environmental radiation dose in Fukushima City increased. On 11 April, 1 mo after the earthquake, the environmental radiation dose rate at various surfaces in the same area differed greatly by surface property. Environmental radiation measurements continue in order to determine the estimated time to 50% reduction in environmental radiation dose rates by surface property in order to make suggestions for decontamination in Fukushima. The measurements were carried out from 11 April to 11 November 2011. Forty-eight (48) measurement points were selected, including four kinds of ground surface properties: grass (13), soil (5), artificial turf (7), and asphalt (23). Environmental radiation dose rate was measured at heights of 100 cm above the ground surface. Time to 50% reduction of environmental radiation dose rates was estimated for each ground surface property. Radiation dose rates on 11 November had decreased significantly compared with those on 11 April for all surface properties. Artificial turf showed the longest time to 50% reduction (544.32 d, standard error: 96.86), and soil showed the shortest (213.20 d, standard error: 35.88). The authors found the environmental radiation dose rate on artificial materials to have a longer 50% reduction time than that on natural materials. These results contribute to determining an order of priority for decontamination after nuclear disasters.

  9. Online-testing system of parameters in aeroplane ground power supply%飞机地面电源供电品质在线测试系统设计

    Institute of Scientific and Technical Information of China (English)

    司剑飞; 郝世勇; 战祥新

    2012-01-01

    Compatible problem occured when aeroplane ground power supply provided electricity to aeroplane because of power supply requirement in aircraft differed from each other. In order to check the dynamic parameters of ground power supply,an online-testing system was designed. Testing items were established based on the analysis of ground power characteristics and requirement of aeroplane power supply. PC/104 embeded computer was the hardware part of the online-testing system, LabVIEW 8. 2 was the software platform of the system. The testing measurement was designed according to GJB 5189-2003. Feasibility of the project was verified by applications.%飞机地面电源向飞机供电时,由于飞机的用电需求差异大,在用电突变过程中,可能存在不适应的现象.为测试地面电源的在线供电品质,检查相互适应性的问题,设计了飞机地面电源在线测试系统.系统参照飞机地面供电特性国军标确定测试内容,硬件采用由PC/104架构计算机、高速并行AD采集卡等构成的嵌入式系统,利用LabVIEW进行系统软件编制,依据GJB5189-2003飞机供电特性参数测试方法设计测试算法.通过在某型地面电源车的实际测试,该系统操作简单、测量准确、便携性好,达到了设计要求,满足了机务工作急需,具有较高的实用价值和经济意义.

  10. Application of bounding spectra to seismic design of piping based on the performance of above ground piping in power plants subjected to strong motion earthquakes

    Energy Technology Data Exchange (ETDEWEB)

    Stevenson, J.D. [Stevenson and Associates, Cleveland, OH (United States)

    1995-02-01

    This report extends the potential application of Bounding Spectra evaluation procedures, developed as part of the A-46 Unresolved Safety Issue applicable to seismic verification of in-situ electrical and mechanical equipment, to in-situ safety related piping in nuclear power plants. The report presents a summary of earthquake experience data which define the behavior of typical U.S. power plant piping subject to strong motion earthquakes. The report defines those piping system caveats which would assure the seismic adequacy of the piping systems which meet those caveats and whose seismic demand are within the bounding spectra input. Based on the observed behavior of piping in strong motion earthquakes, the report describes the capabilities of the piping system to carry seismic loads as a function of the type of connection (i.e. threaded versus welded). This report also discusses in some detail the basic causes and mechanisms for earthquake damages and failures to power plant piping systems.

  11. Simulating Global AeroMACS Airport Ground Station Antenna Power Transmission Limits to Avoid Interference With Mobile Satellite Service Feeder Uplinks

    Science.gov (United States)

    Wilson, Jeffrey D.

    2013-01-01

    The Aeronautical Mobile Airport Communications System (AeroMACS), which is based upon the IEEE 802.16e mobile wireless standard, is expected to be implemented in the 5091 to 5150 MHz frequency band. As this band is also occupied by Mobile Satellite Service feeder uplinks, AeroMACS must be designed to avoid interference with this incumbent service. The aspects of AeroMACS operation that present potential interference are under analysis in order to enable the definition of standards that assure that such interference will be avoided. In this study, the cumulative interference power distribution at low Earth orbit from transmitters at global airports was simulated with the Visualyse Professional software. The dependence of the interference power on antenna distribution, gain patterns, duty cycle, and antenna tilt was simulated. As a function of these parameters, the simulation results are presented in terms of the limitations on transmitter power from global airports required to maintain the cumulative interference power under the established threshold.

  12. 49 CFR 236.107 - Ground tests.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Ground tests. 236.107 Section 236.107...: All Systems Inspections and Tests; All Systems § 236.107 Ground tests. (a) Except as provided in paragraph (b) of this section, a test for grounds on each energy bus furnishing power to circuits,...

  13. Incident, Action, Recovery, and Recommissioning for the 4.5-MJ Pulsed Power Supply Located at the Electromagnetic Gun Facility, Barricade C, Aberdeen Proving Ground, MD

    Science.gov (United States)

    2007-04-01

    modified and, in 2001, was placed back in operation at barricade C to operate with an electromagnetic (EM) railgun load. On 9 February 2006, a capacitor ...MJ. 15. SUBJECT TERMS pulsed power, capacitor , railgun , armature, incident 16. SECURITY CLASSIFICATION OF: 19a. NAME OF RESPONSIBLE PERSON...back in operation at barricade C to operate with an electromagnetic railgun load. The PPS consists of 18 250-kJ independently triggered modules

  14. Unsteady propulsion in ground effects

    Science.gov (United States)

    Park, Sung Goon; Kim, Boyoung; Sung, Hyung Jin

    2016-11-01

    Many animals in nature experience hydrodynamic benefits by swimming or flying near the ground, and this phenomenon is commonly called 'ground effect'. A flexible fin flapping near the ground was modelled, inspired by animals swimming. A transverse heaving motion was prescribed at the leading edge, and the posterior parts of the fin were passively fluttering by the fin-fluid interaction. The fin moved freely horizontally in a quiescent flow, by which the swimming speed was dynamically determined. The fin-fluid interaction was considered by using the penalty immersed boundary method. The kinematics of the flexible fin was altered by flapping near the ground, and the vortex structures generated in the wake were deflected upward, which was qualitatively analyzed by using the vortex dipole model. The swimming speed and the thrust force of the fin increased by the ground effects. The hydrodynamic changes from flapping near the ground affected the required power input in two opposite ways; the increased and decreased hydrodynamic pressures beneath the fin hindered the flapping motion, increasing the power input, while the transversely reduced flapping motion induced the decreased power input. The Froude propulsive efficiency was increased by swimming in the ground effects Creative Research Initiatives (No. 2016-004749) program of the National Research Foundation of Korea (MSIP).

  15. 中国核电工程场地设计地震动参数确定相关问题%The issues related to determination of site specific design ground motion for nuclear power plants in China

    Institute of Scientific and Technical Information of China (English)

    李小军; 贺秋梅; 侯春林

    2013-01-01

      基于中国核电工程选址和建设的实际工作,探讨了核电工程场地设计地震动参数确定几个环节中的关键问题,包括不同地震危险性分析方法的采用、地震动衰减关系的选取和设计地震动参数的综合取值等.分析了地震动衰减关系不确定性和弥散地震衰减关系等问题处理方式的变迁,比较分析了地震危险性分析确定性方法中构造地震、弥散地震的计算结果和概率方法计算结果的差异及对设计地震动参数确定的控制作用.研究表明:a.综合考虑地震危险性分析的确定性方法和概率方法的计算结果已成为中国核电工程场地地震安全性评价中确定设计地震动参数的基本思路,其中弥散地震是一个需要特殊考虑的问题;b.确定性方法和概率方法计算结果对场地设计地震动参数的控制作用受区域地震活动性强弱的影响;c.在地震活动性较弱的地区,确定性方法特别是弥散地震计算结果基本上控制着场地设计地震动参数的取值,而在地震活动性相对较强的地区,更倾向于由概率方法计算结果控制.%Based on the recent practical work of evaluation of seismic safety for the nuclear power plant site selection and construction in China,some key issues were discussed involved in the determination of site specific design ground motion for nuclear power plants,including the seismic hazard analysis methods,the ground motion attenuation relations,and the methods of determining design ground motion parameter. The coun-termeasure change was analyzed to consider the uncertainty of ground motion attenuation relation and the ground motion attenuation relation of diffuse earthquake;the differences were discussed between the computed results from the probabilistic method and the approaches of the diffuse earthquakes and tectonic earthquakes in the deter-ministic method,and their controlling effects were also discussed

  16. Getting grounded: using Glaserian grounded theory to conduct nursing research.

    Science.gov (United States)

    Hernandez, Cheri Ann

    2010-03-01

    Glaserian grounded theory is a powerful research methodology for understanding client behaviour in a particular area. It is therefore especially relevant for nurse researchers. Nurse researchers use grounded theory more frequently than other qualitative analysis research methods because of its ability to provide insight into clients' experiences and to make a positive impact. However, there is much confusion about the use of grounded theory.The author delineates key components of grounded theory methodology, areas of concern, and the resulting implications for nursing knowledge development. Knowledge gained from Glaserian grounded theory research can be used to institute measures for enhancing client-nurse relationships, improving quality of care, and ultimately improving client quality of life. In addition, it can serve to expand disciplinary knowledge in nursing because the resulting substantive theory is a middle-range theory that can be subjected to later quantitative testing.

  17. Ground Wood Fiber Length Distributions

    OpenAIRE

    Lauri Ilmari Salminen; Sari Liukkonen; Alava, Mikko J.

    2014-01-01

    This study considers ground wood fiber length distributions arising from pilot grindings. The empirical fiber length distributions appear to be independent of wood fiber length as well as feeding velocity. In terms of mathematics the fiber fragment distributions of ground wood pulp combine an exponential distribution for high-length fragments and a power-law distribution for smaller lengths. This implies that the fiber length distribution is influenced by the stone surface. A fragmentation-ba...

  18. Enhanced analysis methods to derive the spatial distribution of 131I deposition on the ground by airborne surveys at an early stage after the Fukushima Daiichi nuclear power plant accident.

    Science.gov (United States)

    Torii, Tatsuo; Sugita, Takeshi; Okada, Colin E; Reed, Michael S; Blumenthal, Daniel J

    2013-08-01

    This paper applies both new and well tested analysis methods to aerial radiological surveys to extract the I ground concentrations present after the March 2011 Fukushima Daiichi nuclear power plant (NPP) accident. The analysis provides a complete map of I deposition, an important quantity incalculable at the time of the accident due to the short half-life of I and the complexity of the analysis. A map of I deposition is the first step in conducting internal exposure assessments, population dose reconstruction, and follow-up epidemiological studies. The short half-life of I necessitates the use of aerial radiological surveys to cover the large area quickly, thoroughly, and safely. Teams from the U.S. Department of Energy National Nuclear Security Administration (DOE/NNSA) performed aerial radiological surveys to provide initial maps of the dispersal of radioactive material in Japan. This work reports on analyses performed on a subset of the initial survey data by a joint Japan-U.S. collaboration to determine I ground concentrations. The analytical results show a high concentration of I northwest of the NPP, consistent with the previously reported radioactive cesium deposition, but also shows a significant I concentration south of the plant, which was not observed in the original cesium analysis. The difference in the radioactive iodine and cesium patterns is possibly the result of differences in the ways these materials settle out of the air.

  19. 'Grounded' Politics

    DEFF Research Database (Denmark)

    Schmidt, Garbi

    2012-01-01

    play within one particular neighbourhood: Nørrebro in the Danish capital, Copenhagen. The article introduces the concept of grounded politics to analyse how groups of Muslim immigrants in Nørrebro use the space, relationships and history of the neighbourhood for identity political statements....... The article further describes how national political debates over the Muslim presence in Denmark affect identity political manifestations within Nørrebro. By using Duncan Bell’s concept of mythscape (Bell, 2003), the article shows how some political actors idealize Nørrebro’s past to contest the present...

  20. Dynamics of large-scale ionospheric inhomogeneities caused by a powerful radio emission of the Sura facility from the data collected onto ground-based GNSS network

    Science.gov (United States)

    Kogogin, D. A.; Nasyrov, I. A.; Grach, S. M.; Shindin, A. V.; Zagretdinov, R. V.

    2017-01-01

    The measurements of variations in the total electron content of the Earth's ionosphere along the GPS satellite signal propagation path are described. The signal parameters were measured at a network of receivers at three distant sites: Sura (Vasilsursk), Zelenodolsk, and Kazan. They are arranged along the geomagnetic latitude of the Sura Facility under short-wave radio irradiation of the ionosphere. One feature of the experiment is the crossing of a disturbed region by the radio path between a GPS satellite and Vasilsursk. This resulted from the angular sizes of the Sura array pattern; the radio paths between a GPS satellite and Zelenodolsk and a GPS satellite and Kazan did not cross. Variations in the total electron content of up to 0.15-0.3 TECU were revealed at all three sites during four experimental campaigns (March 2010, March 2013, May 2013, and November 2013). The lateral scale of an ionospheric disturbance stimulated by a high-power radio wave and the velocity of its west-to-east propagation along the geomagnetic latitude were 30-60 km and 270-350 m/s, respectively. A decrease in the total electron content (down to 0.55 TECU) was recorded along the Kazan-Zelenodolsk-Vasilsurks line, which is connected with the solar terminator transit; the lateral scale of the related ionospheric inhomogeneities was 65-80 km.

  1. Ground crewmen maneuver the Helios Prototype flying wing on its ground support dolly during function

    Science.gov (United States)

    2001-01-01

    Ground crewmen maneuver AeroVironment's solar-powered Helios Prototype flying wing on its ground support dolly during functional checkouts prior to its first flights under solar power from the U.S. Navy's Pacific Missile Range Facility on Kaua'i, Hawaii.

  2. 46 CFR 183.376 - Grounded distribution systems (neutral grounded).

    Science.gov (United States)

    2010-10-01

    ... propulsion, power, lighting, or distribution system having a neutral bus or conductor must have the neutral..., circuit breaker, or fuse in the neutral conductor of the bus-tie feeder connecting the emergency... that aluminum grounding conductors must not be used....

  3. Ground Bounce Noise Reduction in Vlsi Circuits

    Directory of Open Access Journals (Sweden)

    Vipin Kumar Sharma

    2015-12-01

    Full Text Available : Scaling of devices in CMOS technology leads to increase in parameter like Ground bounce noise, Leakage current, average power dissipation and short channel effect. FinFET are the promising substitute to replace CMOS. Ground bounce noise is produced when power gating circuit goes from SLEEP to ACTIVE mode transition. FinFET based designs are compared with MOSFET based designs on basis of different parameter like Ground bounce noise, leakage current and average power dissipation. HSPICE is the software tool used for simulation and circuit design.

  4. Powering Future Naval Forces

    Science.gov (United States)

    2010-11-01

    Ground Renewable Expeditionary Energy System Bulk Heterojunction Solar Cell 9  Long endurance fuel cell power (26hr flight Nov 2009)  Low noise...Near Mid Long EMRG Solid State Lights for Submarines Power Node Switching Center Perovskite - based Pyroelectrics 3 Power & Energy Technologies...Fuel Power Generation Energy Storage Distribution& Control Power Loads Fuels Chemistry Alternative Fuels Gas Turbine Generators Fuel Cells Aircraft

  5. Open System of Agile Ground Stations Project

    Data.gov (United States)

    National Aeronautics and Space Administration — There is an opportunity to build the HETE-2/TESS network of ground stations into an innovative and powerful Open System of Agile Stations, by developing a low-cost...

  6. Ground Wood Fiber Length Distributions

    Directory of Open Access Journals (Sweden)

    Lauri Ilmari Salminen

    2014-01-01

    Full Text Available This study considers ground wood fiber length distributions arising from pilot grindings. The empirical fiber length distributions appear to be independent of wood fiber length as well as feeding velocity. In terms of mathematics the fiber fragment distributions of ground wood pulp combine an exponential distribution for high-length fragments and a power-law distribution for smaller lengths. This implies that the fiber length distribution is influenced by the stone surface. A fragmentation-based model is presented that allows reproduction of the empirical results.

  7. Ground water and energy

    Energy Technology Data Exchange (ETDEWEB)

    1980-11-01

    This national workshop on ground water and energy was conceived by the US Department of Energy's Office of Environmental Assessments. Generally, OEA needed to know what data are available on ground water, what information is still needed, and how DOE can best utilize what has already been learned. The workshop focussed on three areas: (1) ground water supply; (2) conflicts and barriers to ground water use; and (3) alternatives or solutions to the various issues relating to ground water. (ACR)

  8. 46 CFR 120.372 - Equipment and conductor grounding.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Equipment and conductor grounding. 120.372 Section 120... INSTALLATION Power Sources and Distribution Systems § 120.372 Equipment and conductor grounding. (a) All... together to a common ground by a normally non-current carrying conductor. Metallic cases of instruments...

  9. Electric power systems

    CERN Document Server

    Weedy, B M; Jenkins, N; Ekanayake, J B; Strbac, G

    2012-01-01

    The definitive textbook for Power Systems students, providing a grounding in essential power system theory while also focusing on practical power engineering applications. Electric Power Systems has been an essential book in power systems engineering for over thirty years. Bringing the content firmly up-to-date whilst still retaining the flavour of Weedy's extremely popular original, this Fifth Edition has been revised by experts Nick Jenkins, Janaka Ekanayake and Goran Strbac. This wide-ranging text still covers all of the fundamental power systems subjects but is now e

  10. 29 CFR 1926.954 - Grounding for protection of employees.

    Science.gov (United States)

    2010-07-01

    ..., DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Power Transmission and... the new lines or equipment. (c) Communication conductors. Bare wire communication conductors on power... operation of protective devices. (i) Grounding to tower. Grounding to tower shall be made with a tower...

  11. Analytical study on aseismic base isolation in new offshore location. For practical location for thermal power plants by soft-landing artificial ground construction method; Atarashii kaijo ricchi ni okeru menshinsei ni kansuru kaisekiteki kento. Nanchaku jinko jiban koho ni yoru karyoku hatsuden setsubi ricchi jitsuyoka ni mukete

    Energy Technology Data Exchange (ETDEWEB)

    Kawamura, T.; Sakakibara, T. [Tokyo Electric Power Co. Inc., Tokyo (Japan); Ishikawa, M. [Nikken Sekkei Ltd., Osaka (Japan)

    1996-09-05

    Assuming offshore location of thermal power plants by soft-landing artificial ground construction method, its effect on uneven settlement of facility unit group and its seismic behavior were studied. In soft-landing artificial ground, the total weight and buoyancy of a caisson body with interior space are balanced by controlling water level in a tank to reduce landing pressure. Artificial ground resists lateral seismic external force by friction with submarine bedrock. Settlement analysis and seismic behavior analysis were conducted by 2-D FEM. As a result, bottom RC honeycomb structure was sufficient to resist uneven settlement during construction even under fixed junction condition between units. In soft-landing artificial ground, the maximum acceleration was reduced to nearly 70% by aseismic base isolation as compared with conventional methods. In addition, its sliding manner in earthquake was different from that of rigid bodies, and the maximum stress acceleration transmitted to the bottom of artificial ground changed even under the same waveform. 4 refs., 13 figs., 4 tabs.

  12. Grounded coplanar waveguide defected ground structure enabled mulitlayered passive circuits

    Science.gov (United States)

    Schlieter, Daniel Benjamin

    Passive circuits are essential to microwave and millimeter-wave (mm-wave) frequency design, especially as new commercial applications emerge for complementary metal-oxide semiconductor (CMOS) integrated circuits. However, it is challenging to design distributed passive circuits for CMOS due to the substrate loss and thin dielectric layers of the back-end-of-line (BEOL). Furthermore, distributed passive circuits need to be adapted for compactness and integration while overcoming these challenges and maintaining high performance. Grounded coplanar waveguide defected ground structures meet this need for compact and integrable passive circuits by utilizing the top and bottom ground planes of the transmission line to implement circuit elements. Defected ground structures (DGS) are distributed elements realized by etching specific patterns into the ground planes of transmission lines. These structures can be used in conjunction with the center conductor of planar transmission lines to reduce circuit size and/or improve performance. By implementing DGS in grounded coplanar waveguide (GCPW) multiple resonances and higher impedances can be achieved. The resonant-based GCPW DGS are more compact than their microstrip and CPW counterparts and fit well into the vertical technology of back-end-of-line CMOS. This research demonstrates up to 80% size reduction at 5.8GHz by realizing spiral-shaped DGS in GCPW and applying the resulting GCPW DGS unit cell to a dual-behavior band-pass filter. The filter has been scaled to 60GHz and realized in a 130nm CMOS process by using floating metal strips to reduce the impact of the lossy silicon substrate. The impedance-based GCPW DGS, called EG-GCPW, have up to a 20:1 impedance ratio on Rogers RT/DuroidRTM 5880 and an impedance ratio of 15:1 on a benzocyclobutene post-CMOS process. These high impedance ratios increased the power division ratio of an unequal Wilkinson power divider to 7:1 and reduced the size of a stepped impedance low

  13. A Comparative Parametric Analysis of the Ground Fault Current Distribution on Overhead Transmission Lines

    OpenAIRE

    VINTAN, M.

    2016-01-01

    The ground fault current distribution in an effectively grounded power network is affected by various factors, such as: tower footing impedances, spans lengths, configuration and parameters of overhead ground wires and power conductors, soil resistivity etc. In this paper, we comparatively analyze, using different models, the ground fault current distribution in a single circuit transmission line with one ground wire. A parametric comparative analysis was done in order to stud...

  14. Evaluating transmission towers potentials during ground faults

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    During ground faults on transmission lines, a number of towers near the fault are likely to acquire high potentials to ground. These tower voltages, if excessive, may present a hazard to humans and animals. This paper presents analytical methods in order to determine the transmission towers potentials during ground faults, for long and short lines. The author developed a global systematic approach to calculate these voltages, which are dependent of a number of factors. Some of the most important factors are: magnitudes of fault currents, fault location with respect to the line terminals, conductor arrangement on the tower and the location of the faulted phase, the ground resistance of the faulted tower, soil resistivity, number, material and size of ground wires. The effects of these factors on the faulted tower voltages have been also examined for different types of power lines.

  15. A New Method of Grounding Grid Design

    Directory of Open Access Journals (Sweden)

    Feng Zhen-Bao

    2016-01-01

    Full Text Available In order to equalize the electric potential distribution of the grounding grid surface, and improve the safety level of the grounding grid, method for optimal arrangement of conducts in the grounding grid is proposed in this paper. The calculation results about maximum touch voltages and mesh potentials show that the method can reduce touch voltage and equilibrium surface potential. It is shown that the design of the grounding grid is related to not only the soil environment, but also the rectangular shape. Comparing with other methods, the method proposed in the paper can reduce maximum touch voltage about 12%. This method also can be applied in a uniform and non-uniform soil, rectangular and square grounding grids. The optimize effect meets the related standards of the power industry.

  16. Aircraft Ground Operation, Servicing, Fluid Lines and Fittings, Mechanics Privileges and Limitations, and Maintenance Publications, Forms and Records (Course Outline), Aviation Mechanics 1 (Power and Frame): 9073.02.

    Science.gov (United States)

    Dade County Public Schools, Miami, FL.

    The course outline consists of five instructional blocks of several units each: (1) Aircraft Ground Operation and Servicing; (2) Fluid Lines and Fittings; (3) Mechanics Requirements, Privileges and Limitations; (4) Maintenance Publications; and, (5) Maintenance forms and Records. It is a basic course of knowledge and skills necessary to any…

  17. Airport Ground Staff Scheduling

    DEFF Research Database (Denmark)

    Clausen, Tommy

    travels safely and efficiently through the airport. When an aircraft lands, a significant number of tasks must be performed by different groups of ground crew, such as fueling, baggage handling and cleaning. These tasks must be complete before the aircraft is able to depart, as well as check......-in and security services. These tasks are collectively known as ground handling, and are the major source of activity with airports. The business environments of modern airports are becoming increasingly competitive, as both airports themselves and their ground handling operations are changing to private...... ownership. As airports are in competition to attract airline routes, efficient and reliable ground handling operations are imperative for the viability and continued growth of both airports and airlines. The increasing liberalization of the ground handling market prompts ground handling operators...

  18. [Introduction to grounded theory].

    Science.gov (United States)

    Wang, Shou-Yu; Windsor, Carol; Yates, Patsy

    2012-02-01

    Grounded theory, first developed by Glaser and Strauss in the 1960s, was introduced into nursing education as a distinct research methodology in the 1970s. The theory is grounded in a critique of the dominant contemporary approach to social inquiry, which imposed "enduring" theoretical propositions onto study data. Rather than starting from a set theoretical framework, grounded theory relies on researchers distinguishing meaningful constructs from generated data and then identifying an appropriate theory. Grounded theory is thus particularly useful in investigating complex issues and behaviours not previously addressed and concepts and relationships in particular populations or places that are still undeveloped or weakly connected. Grounded theory data analysis processes include open, axial and selective coding levels. The purpose of this article was to explore the grounded theory research process and provide an initial understanding of this methodology.

  19. Ground Vehicle Robotics

    Science.gov (United States)

    2013-08-20

    Ground Vehicle Robotics Jim Parker Associate Director, Ground Vehicle Robotics UNCLASSIFIED: Distribution Statement A. Approved for public...DATE 20 AUG 2013 2. REPORT TYPE Briefing Charts 3. DATES COVERED 09-05-2013 to 15-08-2013 4. TITLE AND SUBTITLE Ground Vehicle Robotics 5a...Willing to take Risk on technology -User Evaluated -Contested Environments -Operational Data Applied Robotics for Installation & Base Ops -Low Risk

  20. Effects of ground motion spatial variation on seismic response of a power transmission tower-line system%地震动空间变化对高压输电塔线体系地震反应的影响

    Institute of Scientific and Technical Information of China (English)

    田利; 李宏男; 王文明

    2013-01-01

    Here, effects of ground motion spatial variation on seismic response of a power transmission tower-line system were studied with numerical simulations. A three-dimensional finite element model for the power transmission tower-line coupled system considering the geometric nonlinearity of transmission line was established. Based on wave passage effect, coherency loss effect, different local site effect and multi-dimensional nature of ground motion, spatially varying ground motion time histories were simulated according to power spectral density function, coherency loss function and Code for Design of Seismic of Electrical Installations. The effects of wave passage, coherency loss and different local site effect on the seismic response of the transmission tower-line system were investigated, respectively. The results showed that the effects of ground motion spatial variation have significant influence on the seismic response of the transmission tower-line system; neglecting these effects may underestimate the response of the structure; the effects of ground motion spatial variation should be considered in seismic design of transmission line practical engineering.%通过数值模拟研究了地震动空间变化对高压输电塔线体系地震反应的影响.建立了输电塔线耦联体系三维有限元模型,考虑了输电线的几何非线性特征;在考虑地震动的行波效应、部分相干效应和局部场地效应以及多维性基础上,依据功率谱密度函数、相干函数和《电力设施抗震设计规范》模拟了空间变化地震动时程;分别研究了地震动空间变化的行波效应、部分相干效应和局部场地效应对输电塔线体系地震反应的影响.研究结果表明,地震动空间变化对输电塔线体系地震反应影响显著,忽略这些因素将会低估结构的反应.因此对于输电线路实际工程的抗震设计,需要考虑地震动空间变化效应的影响.

  1. The Grounded Theory Bookshelf

    Directory of Open Access Journals (Sweden)

    Vivian B. Martin, Ph.D.

    2005-03-01

    Full Text Available Bookshelf will provide critical reviews and perspectives on books on theory and methodology of interest to grounded theory. This issue includes a review of Heaton’s Reworking Qualitative Data, of special interest for some of its references to grounded theory as a secondary analysis tool; and Goulding’s Grounded Theory: A practical guide for management, business, and market researchers, a book that attempts to explicate the method and presents a grounded theory study that falls a little short of the mark of a fully elaborated theory.Reworking Qualitative Data, Janet Heaton (Sage, 2004. Paperback, 176 pages, $29.95. Hardcover also available.

  2. 基于恒流场理论的山岩地区输电线路杆塔接地降阻的新方法%A New Method to Reduce Grounding Resistance of Power Transmission Tower in Rocky Region Based on the Constant Current Field Theory

    Institute of Scientific and Technical Information of China (English)

    杨廷方; 李景禄; 周力行; 杨鑫

    2011-01-01

    为了减少输电线路的雷击跳闸率,基于恒流场理论,提出了一种直接利用输电线路杆塔基础进行降阻的新方法。该方法将特制钢筋笼与相应比例的高效防腐降阻剂结合,对杆塔基础进行集中接地。该装置占地空间少,需要土量少,解决了水平射线因受地形限制而降阻困难的问题。其冲击系数小和冲击电阻小的特性,大大提高了线路的耐雷水平以及供电可靠性。实例和实践结果都表明了该方法的可行性及有效性。%To decrease the lightning trip-out rate of transmission line,a new method therefore was put forward to reduce the grounding resistance of transmission tower foundation based on the constant current field theory.This method combined special reinforcing cage with proportional effective anti-corrosion resistance reduction agent to make tower foundation ground tightly,and took up a little space and soil.And all the problems such as reducing grounding resistance by horizontal radial grounding method because of topography were solved.The characteristic of small impulse coefficient and impulse grounding resistance of this device increased the lightning withstand level and power supply reliability of transmission line greatly.Results of instances and practices showed that this method is feasible and validated.

  3. Pesticides in Ground Water

    DEFF Research Database (Denmark)

    Bjerg, Poul Løgstrup

    1996-01-01

    Review af: Jack E. Barbash & Elizabeth A. Resek (1996). Pesticides in Ground Water. Distribution trends and governing factors. Ann Arbor Press, Inc. Chelsea, Michigan. pp 588.......Review af: Jack E. Barbash & Elizabeth A. Resek (1996). Pesticides in Ground Water. Distribution trends and governing factors. Ann Arbor Press, Inc. Chelsea, Michigan. pp 588....

  4. Pesticides in Ground Water

    DEFF Research Database (Denmark)

    Bjerg, Poul Løgstrup

    1996-01-01

    Review af: Jack E. Barbash & Elizabeth A. Resek (1996). Pesticides in Ground Water. Distribution trends and governing factors. Ann Arbor Press, Inc. Chelsea, Michigan. pp 588.......Review af: Jack E. Barbash & Elizabeth A. Resek (1996). Pesticides in Ground Water. Distribution trends and governing factors. Ann Arbor Press, Inc. Chelsea, Michigan. pp 588....

  5. Communication, concepts and grounding.

    Science.gov (United States)

    van der Velde, Frank

    2015-02-01

    This article discusses the relation between communication and conceptual grounding. In the brain, neurons, circuits and brain areas are involved in the representation of a concept, grounding it in perception and action. In terms of grounding we can distinguish between communication within the brain and communication between humans or between humans and machines. In the first form of communication, a concept is activated by sensory input. Due to grounding, the information provided by this communication is not just determined by the sensory input but also by the outgoing connection structure of the conceptual representation, which is based on previous experiences and actions. The second form of communication, that between humans or between humans and machines, is influenced by the first form. In particular, a more successful interpersonal communication might require forms of situated cognition and interaction in which the entire representations of grounded concepts are involved.

  6. Stochastic ground motion simulation

    Science.gov (United States)

    Rezaeian, Sanaz; Xiaodan, Sun; Beer, Michael; Kougioumtzoglou, Ioannis A.; Patelli, Edoardo; Siu-Kui Au, Ivan

    2014-01-01

    Strong earthquake ground motion records are fundamental in engineering applications. Ground motion time series are used in response-history dynamic analysis of structural or geotechnical systems. In such analysis, the validity of predicted responses depends on the validity of the input excitations. Ground motion records are also used to develop ground motion prediction equations(GMPEs) for intensity measures such as spectral accelerations that are used in response-spectrum dynamic analysis. Despite the thousands of available strong ground motion records, there remains a shortage of records for large-magnitude earthquakes at short distances or in specific regions, as well as records that sample specific combinations of source, path, and site characteristics.

  7. Ground energy coupling

    Science.gov (United States)

    Metz, P. D.

    The feasibility of ground coupling for various heat pump systems was investigated. Analytical heat flow models were developed to approximate design ground coupling devices for use in solar heat pump space conditioning systems. A digital computer program called GROCS (GRound Coupled Systems) was written to model 3-dimensional underground heat flow in order to simulate the behavior of ground coupling experiments and to provide performance predictions which have been compared to experimental results. GROCS also has been integrated with TRNSYS. Soil thermal property and ground coupling device experiments are described. Buried tanks, serpentine earth coils in various configurations, lengths and depths, and sealed vertical wells are being investigated. An earth coil used to heat a house without use of resistance heating is described.

  8. Management Research and Grounded Theory: A review of grounded theorybuilding approach in organisational and management research.

    Directory of Open Access Journals (Sweden)

    Graham J.J. Kenealy, Ph.D.

    2008-06-01

    Full Text Available Grounded theory is a systematic methodology for the collection and analysis of data which was discovered by Glaser and Strauss in the 1960’s. The discovery of this method was first presented to the academic community in their book ‘The Discovery of Grounded Theory’ (1967 which still remains a primary point of reference for those undertaking qualitative research and grounded theory in particular. This powerful research method has become very popular in some research domains; whilst increasing in popularity it is still less prevalent in the field of organisational and management research particularly in its original form. This self reflexive paper sets out to explore the possibilities for this imbalance which takes the discussion onto the areas of methodological adaptation and training. It also enters the debate about access to research subjects and provides a succinct argument supporting the notion that grounded theory should simply be viewed as a method that develops empirically grounded conceptual theory.

  9. Research and Application on Lightning Protection Grounding Technology for Large Scale Photovol-taic Power Generation System in Mountainous Areas%山区大型光伏发电系统防雷接地技术探究与应用

    Institute of Scientific and Technical Information of China (English)

    孙录贵

    2015-01-01

    Photovoltaic power generation system is based on a film area of solar panels. In order to avoid the waste of land resources,generally large-scale solar photovoltaic generation stations are built on the hillside far away from the town,where is empty,without high-buildings,in high risk area of lightning.It is especially important to make sure the quality of lightning protection earthing electrodes for the electrical resistivity of mountains soil is very high ,fur-thermore it with largescope of radiation,much electrical equipment in power station.In this article,explored the pho-tovoltaic power generation system on the slope of the high resistance of grounding technology theory method by twen-ty MW ground actual problems in the first phase of the photovoltaic powers station project in Xuanyang village Xieji town Yongqiao district. Make the photovoltaic power grounding system in accordance with the requirements of the drawings design basis.Achieve"adjust measures to local conditions,economic and reasonable". Finally the popular-ization and application of the conclution can be maken.%光伏发电系统需要成片区的太阳能电池板作为基础,为了尽量减小对土地的浪费,大型太阳能光伏发电站往往都建设在偏离城镇的山坡上,环境空旷,周边没有高大建筑物防护,其本身就处于雷击高风险区域,而且山区土壤电阻率较高,辐射范围大,电站内电气设备较多,因而确保防雷接地质量尤为重要.该文通过分析埇桥区谢集乡宣杨村20MW地面光伏电站项目一期工程遇到的实际问题,探究在高阻区的山坡上完成光伏发电系统防雷接地技术的方法,使光伏发电接地系统在符合图纸设计要求的基础上,做到"因地制宜、经济合理"并加以推广运用.

  10. Microwave Power Transmission Technologies for SPS

    Science.gov (United States)

    Shinohara, Naoki; Hashimoto, Kozo

    This paper describes the wireless power transmission via microwave (MPT) system for the Space Solar Power Station/Satellite (SPS). The SPS will be hugest space system and we need high efficient, huge, high accurate, light weight and inexpensive phased array for the SPS. Now we do not have any commercial MPT system on ground. Therefore, we have to consider the roadmap of the MPT system from the ground application to the SPS. We propose three step application of the MPT as follows 1st Step: Weak Power Wireless Power Transmission (Ubiquitous Power Source, RF-ID, Energy Harvesting) under Present Radio Wave Configuration or High Power Wireless Power Transmission in Closed Area 2nd Step: High Power Wireless Power Transmission to/from Moving Target/Source with Phased Array under New Radio Wave Configuration (Special Frequency for WPT) on Ground 3rd (Final) Step: Wireless Power Transmission in Space (SPS)

  11. On grounding equipment construction of wind power stations at mountains with high earth resistivity%高土壤电阻率山地风电工程接地装置施工探讨

    Institute of Scientific and Technical Information of China (English)

    涂晓

    2016-01-01

    结合某风电场工程的实际情况,提出了该风电工程中接地布置的设计要求,并针对接地装置的施工难点提出了具体的解决措施,有利于保证接地装置的施工质量,维护电力系统的稳定运行。%Combininf with the fact at some wind power project,the paper points out the desifn requirements for the froundinf allocation of the wind power projects,and points out the solutions accordinf to the construction difficulties of the froundinf equipment,so as to ensure the con-struction quality of the equipment,and maintain the stable operation of the power system.

  12. Enabling Wind Power Nationwide

    Energy Technology Data Exchange (ETDEWEB)

    Jose Zayas, Michael Derby, Patrick Gilman and Shreyas Ananthan,

    2015-05-01

    Leveraging this experience, the U.S. Department of Energy’s (DOE’s) Wind and Water Power Technologies Office has evaluated the potential for wind power to generate electricity in all 50 states. This report analyzes and quantifies the geographic expansion that could be enabled by accessing higher above ground heights for wind turbines and considers the means by which this new potential could be responsibly developed.

  13. Development and application of mechanical calculation and drawing software for conducting wire and ground wire of power transmission line%送电线路导地线力学计算绘图软件的开发与应用

    Institute of Scientific and Technical Information of China (English)

    梁世党

    2012-01-01

      以开发“送电线路导地线力学计算绘图”软件为例,介绍了如何在Excel 2007中利用Visual Basic语言开发一个能快速绘制各种设计气象条件、不同导地线型号的送电线路导地线应力弧垂计算及绘图的应用程序,供工程设计人员在Excel 2007二次开发中作为参考,从而提高绘图效率。%  Taking the development of mechanical calculation and drawing software for conducting wire and ground wire of power transmission line as example, the author presented how to use Excel 2007 and Visual Basic language to develop an application software which permits rapid stress sag calculation and drawing for different types of con⁃ducting wire and ground wire of power transmission line under various meteorological conditions, aiming to provide reference for secondary development of Excel 2007 and higher drawing efficiency.

  14. Ground Surface Power Supply Mode for the Deep -well Motor in Oil -well Logging Devices%油田测井装置深井电机地面供电方式的研究

    Institute of Scientific and Technical Information of China (English)

    彭其泽; 张全柱

    2011-01-01

    Power supply modes for driving hydraulic pump motor at the oil - well logging device were discussed. And advantages and disadvantages of six power supply modes were analyzed and compared with each other. A most promising motor power supply mode was then put forward. This mode has overcome disadvantages existed in traditional oil - well logging power supply method, I. E. , the transitional "voltage regulator along with transformer" method. The proposed power supply mode has advantages of small volume,light weight,convenient voltage regulation,small starting voltage,fast transient response,and high intelligence degree. This power supply is composed of several ICBT power transforming units,and has realized the transformation from single - phase low voltage of AC110V to dual -phase middle voltage of AC600 ~ AC1200V after multiple AC/DC/AC - AC/DC/AC voltage transform links.%针对油田测井装置的驱动液压泵电机的供电方式进行了研究,比较分析了6种供电方式的优缺点,提出一种最有应用前途的电机供电方式.该供电方式克服了传统的调压器加变压器的油田测井电源方式的诸多缺点,具有体积小、重量轻、电压调节方便、起动电流小、动态响应快和智能化程度高等优点.该电源由多个IGBT功率变换单元组成,经过AC/DC/AC—AC/DC/AC多个电压变换环节,实现从单相AC 110 V低压至双相AC600~AC 1 200V中压的变换.

  15. Advanced Testing Method for Ground Thermal Conductivity

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiaobing [ORNL; Clemenzi, Rick [Geothermal Design Center Inc.; Liu, Su [University of Tennessee (UT)

    2017-04-01

    A new method is developed that can quickly and more accurately determine the effective ground thermal conductivity (GTC) based on thermal response test (TRT) results. Ground thermal conductivity is an important parameter for sizing ground heat exchangers (GHEXs) used by geothermal heat pump systems. The conventional GTC test method usually requires a TRT for 48 hours with a very stable electric power supply throughout the entire test. In contrast, the new method reduces the required test time by 40%–60% or more, and it can determine GTC even with an unstable or intermittent power supply. Consequently, it can significantly reduce the cost of GTC testing and increase its use, which will enable optimal design of geothermal heat pump systems. Further, this new method provides more information about the thermal properties of the GHEX and the ground than previous techniques. It can verify the installation quality of GHEXs and has the potential, if developed, to characterize the heterogeneous thermal properties of the ground formation surrounding the GHEXs.

  16. Ground State Spin Logic

    CERN Document Server

    Whitfield, J D; Biamonte, J D

    2012-01-01

    Designing and optimizing cost functions and energy landscapes is a problem encountered in many fields of science and engineering. These landscapes and cost functions can be embedded and annealed in experimentally controllable spin Hamiltonians. Using an approach based on group theory and symmetries, we examine the embedding of Boolean logic gates into the ground state subspace of such spin systems. We describe parameterized families of diagonal Hamiltonians and symmetry operations which preserve the ground state subspace encoding the truth tables of Boolean formulas. The ground state embeddings of adder circuits are used to illustrate how gates are combined and simplified using symmetry. Our work is relevant for experimental demonstrations of ground state embeddings found in both classical optimization as well as adiabatic quantum optimization.

  17. Ground Vehicle Robotics Presentation

    Science.gov (United States)

    2012-08-14

    Mr. Jim Parker Associate Director Ground Vehicle Robotics Distribution Statement A. Approved for public release Report Documentation Page...Briefing 3. DATES COVERED 01-07-2012 to 01-08-2012 4. TITLE AND SUBTITLE Ground Vehicle Robotics Presentation 5a. CONTRACT NUMBER 5b. GRANT...ABSTRACT Provide Transition-Ready, Cost-Effective, and Innovative Robotics and Control System Solutions for Manned, Optionally-Manned, and Unmanned

  18. Power and environmental assessment

    DEFF Research Database (Denmark)

    Cashmore, Matthew Asa; Richardson, Tim

    2013-01-01

    The significance of politics and power dynamics has long been recognised in environmental assessment (EA) research, but there has not been sustained attention to power, either theoretically or empirically. The aim of this special issue is to encourage the EA community to engage more consistently...... with the issue of power. The introduction represents a ground-clearing exercise intended to clarify the terms of the debate about power in the EA field, and to contribute to the development of a research agenda. Research trends in the field are outlined, and potential analytic and normative lines of inquiry...... are identified. The contributions to this special issue represent contrasting conceptual and methodological approaches that navigate the analytical and normative terrain of power dynamics in EA. Together, they demonstrate that power cannot be removed from EA policy or practices, and is a necessary research focus...

  19. 电力系统接地用镀锌扁钢腐蚀分析与研究%Corrosion Analysis on Galvanized Flat Steel Grounding Electrode of Power System

    Institute of Scientific and Technical Information of China (English)

    王森; 骆鸿; 李志忠; 肖葵; 吉宏亮; 董超芳

    2011-01-01

    针对某电力系统接地金属材料镀锌扁钢在土壤中服役11年后的腐蚀行为,采用金相、扫描电镜、能谱和X射线衍射等技术对其进行了宏观分析、组织分析、腐蚀产物分析和断口分析.结果表明,该镀锌扁钢接地极的腐蚀类型属全面腐蚀,腐蚀产物主要由FeOOH和Fe3O4等组成.镀锌扁钢基体中发现一些颗粒状的Al-Si复合型夹杂物,这些夹杂物的存在促进了腐蚀的发生和发展,并在局部区域为侵蚀性离子渗入基体提供了通道.研究结论表明在腐蚀环境作用下,镀锌扁钢发生腐蚀与导电性能失效是影响接地网的散流特性和寿命的主要原因.%The corrosion behavior of galvanized flat steel, which has been used for more than eleven years in the soil environment, is investigated by using optical microscopy, scanning electron microscopy, and X-ray diffraction techniques. It is found that the corrosion type of galvanized flat steel is mainly general corrosion after buried in soil. The corrosion products are composed of FeOOH, Fe3O4 and others. The EDS results show that there are some sulfur elements in the corrosion product, and the elements might be caused by the sulfate -reducing bacteria. Also there are some Al-Si composite granular inclusions existing in the substrate of galvanized steel, and the inclusions could promote the corrosion occurrence and development, therefore provide the channel for the corrosive ion to permeate into matrix in the local region. In order to extend the lifespan of grounding electrode in the soil, the galvanized steel is often considered in the design. The zinc in the soil is priority eroded to protect ordinary carbon steel's lifespan. In the absence of current role, the service lifespan of galvanized steel is indeed better. However, due to the role of the ground current, as the ground material, galvanized steel surface electrolytic zinc coating will soon come off; then the corrosion rate of grounding

  20. Simulation of non-stationary ground motion processes (II)

    Institute of Scientific and Technical Information of China (English)

    LIANG Jian-wen

    2005-01-01

    This paper proposes a method for simulation of non-stationary ground motion processes having the identical statistical feature, time-dependent power spectrum, with a given ground motion record, on the basis of review of simulation of non-stationary ground motion processes. The method has the following advantages: the sample processes are non-stationary both in amplitude and frequency, and both the amplitude and frequency non-stationarity depend on the target power spectrum; the power spectrum of any sample process does not necessarily accord with the target power spectrum, but statistically, it strictly accords with the target power spectrum. Finally, the method is verified by simulation of one acceleration record in Landers earthquake.

  1. Ground Enterprise Management System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Emergent Space Technologies Inc. proposes to develop the Ground Enterprise Management System (GEMS) for spacecraft ground systems. GEMS will provide situational...

  2. Grounding word learning in space.

    Directory of Open Access Journals (Sweden)

    Larissa K Samuelson

    Full Text Available Humans and objects, and thus social interactions about objects, exist within space. Words direct listeners' attention to specific regions of space. Thus, a strong correspondence exists between where one looks, one's bodily orientation, and what one sees. This leads to further correspondence with what one remembers. Here, we present data suggesting that children use associations between space and objects and space and words to link words and objects--space binds labels to their referents. We tested this claim in four experiments, showing that the spatial consistency of where objects are presented affects children's word learning. Next, we demonstrate that a process model that grounds word learning in the known neural dynamics of spatial attention, spatial memory, and associative learning can capture the suite of results reported here. This model also predicts that space is special, a prediction supported in a fifth experiment that shows children do not use color as a cue to bind words and objects. In a final experiment, we ask whether spatial consistency affects word learning in naturalistic word learning contexts. Children of parents who spontaneously keep objects in a consistent spatial location during naming interactions learn words more effectively. Together, the model and data show that space is a powerful tool that can effectively ground word learning in social contexts.

  3. The ATLAS SCT grounding and shielding concept and implementation

    CERN Document Server

    Bates, RL; Bernabeu, J; Bizzell, J; Bohm, J; Brenner, R; Bruckman de Renstrom, P A; Catinaccio, A; Cindro, V; Ciocio, A; Civera, J V; Chouridou, S; Dervan, P; Dick, B; Dolezal, Z; Eklund, L; Feld, L; Ferrere, D; Gadomski, S; Gonzalez, F; Gornicki, E; Greenhall, A; Grillo, A A; Grosse-Knetter, J; Gruwe, M; Haywood, S; Hessey, N P; Ikegami, Y; Jones, T J; Kaplon, J; Kodys, P; Kohriki, T; Kondo, T; Koperny, S; Lacasta, C; Lozano Bahilo, J; Malecki, P; Martinez-McKinney, F; McMahon, S J; McPherson, A; Mikulec, B; Mikus, M; Moorhead, G F; Morrissey, M C; Nagai, K; Nichols, A; O'Shea, V; Pater, J R; Peeters, S J M; Pernegger, H; Perrin, E; Phillips, P W; Pieron, J P; Roe, S; Sanchez, J; Spencer, E; Stastny, J; Tarrant, J; Terada, S; Tyndel, M; Unno, Y; Wallny, R; Weber, M; Weidberg, A R; Wells, P S; Werneke, P; Wilmut, I

    2012-01-01

    This paper describes the design and implementation of the grounding and shielding system for the ATLAS SemiConductor Tracker (SCT). The mitigation of electromagnetic interference and noise pickup through power lines is the critical design goal as they have the potential to jeopardize the electrical performance. We accomplish this by adhering to the ATLAS grounding rules, by avoiding ground loops and isolating the different subdetectors. Noise sources are identified and design rules to protect the SCT against them are described. A rigorous implementation of the design was crucial to achieve the required performance. This paper highlights the location, connection and assembly of the different components that affect the grounding and shielding system: cables, filters, cooling pipes, shielding enclosure, power supplies and others. Special care is taken with the electrical properties of materials and joints. The monitoring of the grounding system during the installation period is also discussed. Finally, after con...

  4. Reinventing Grounded Theory: Some Questions about Theory, Ground and Discovery

    Science.gov (United States)

    Thomas, Gary; James, David

    2006-01-01

    Grounded theory's popularity persists after three decades of broad-ranging critique. In this article three problematic notions are discussed--"theory," "ground" and "discovery"--which linger in the continuing use and development of grounded theory procedures. It is argued that far from providing the epistemic security promised by grounded theory,…

  5. Ground motion estimation and nonlinear seismic analysis

    Energy Technology Data Exchange (ETDEWEB)

    McCallen, D.B.; Hutchings, L.J.

    1995-08-14

    Site specific predictions of the dynamic response of structures to extreme earthquake ground motions are a critical component of seismic design for important structures. With the rapid development of computationally based methodologies and powerful computers over the past few years, engineers and scientists now have the capability to perform numerical simulations of many of the physical processes associated with the generation of earthquake ground motions and dynamic structural response. This paper describes application of a physics based, deterministic, computational approach for estimation of earthquake ground motions which relies on site measurements of frequently occurring small (i.e. M < 3 ) earthquakes. Case studies are presented which illustrate application of this methodology for two different sites, and nonlinear analyses of a typical six story steel frame office building are performed to illustrate the potential sensitivity of nonlinear response to site conditions and proximity to the causative fault.

  6. Ground water in Oklahoma

    Science.gov (United States)

    Leonard, A.R.

    1960-01-01

    One of the first requisites for the intelligent planning of utilization and control of water and for the administration of laws relating to its use is data on the quantity, quality, and mode of occurrence of the available supplies. The collection, evaluation and interpretation, and publication of such data are among the primary functions of the U.S. Geological Survey. Since 1895 the Congress has made appropriations to the Survey for investigation of the water resources of the Nation. In 1929 the Congress adopted the policy of dollar-for-dollar cooperation with the States and local governmental agencies in water-resources investigations of the U.S. Geological Survey. In 1937 a program of ground-water investigations was started in cooperation with the Oklahoma Geological Survey, and in 1949 this program was expanded to include cooperation with the Oklahoma Planning and Resources Board. In 1957 the State Legislature created the Oklahoma Water Resources Board as the principal State water agency and it became the principal local cooperator. The Ground Water Branch of the U.S. Geological Survey collects, analyzes, and evaluates basic information on ground-water resources and prepares interpretive reports based on those data. Cooperative ground-water work was first concentrated in the Panhandle counties. During World War II most work was related to problems of water supply for defense requirements. Since 1945 detailed investigations of ground-water availability have been made in 11 areas, chiefly in the western and central parts of the State. In addition, water levels in more than 300 wells are measured periodically, principally in the western half of the State. In Oklahoma current studies are directed toward determining the source, occurrence, and availability of ground water and toward estimating the quantity of water and rate of replenishment to specific areas and water-bearing formations. Ground water plays an important role in the economy of the State. It is

  7. Detection of ground ice using ground penetrating radar method

    Institute of Scientific and Technical Information of China (English)

    Gennady M. Stoyanovich; Viktor V. Pupatenko; Yury A. Sukhobok

    2015-01-01

    The paper presents the results of a ground penetrating radar (GPR) application for the detection of ground ice. We com-bined a reflection traveltime curves analysis with a frequency spectrogram analysis. We found special anomalies at specific traces in the traveltime curves and ground boundaries analysis, and obtained a ground model for subsurface structure which allows the ground ice layer to be identified and delineated.

  8. Collison and Grounding

    DEFF Research Database (Denmark)

    Wang, G.; Ji, C.; Kuhala, P.;

    2006-01-01

    COMMITTEE MANDATE Concern for structural arrangements on ships and floating structures with regard to their integrity and adequacy in the events of collision and grounding, with the view towards risk assessment and management. Consideration shall be given to the frequency of occurrence, the proba......COMMITTEE MANDATE Concern for structural arrangements on ships and floating structures with regard to their integrity and adequacy in the events of collision and grounding, with the view towards risk assessment and management. Consideration shall be given to the frequency of occurrence...

  9. Comprehensive Analysis of Lightning Performance of Overhead Power Distribution Line with Varied Ground Obliquity%不同地形条件下架空配电线路的防雷分析

    Institute of Scientific and Technical Information of China (English)

    刘靖; 刘明光; 屈志坚; 刘铁

    2011-01-01

    In order to take lightning problem into consideration comprehensively, we introduced a new model for calculating the lightning outage rate of overhead power distribution line due to direct and indirect lightning strokes. By establishing an improved EGM model of overhead distribution line based on striking distance theory, combining with probability density function of lightning current, we solved the attract range of overhead line, which possesses a nonlinear relationship with line height for different district. Taking the Rusck's formula into consideration, basing on Generalized Integral method, we put forward a new arithmetic for calculating the lightning outage rate which includes indirect lightning. By calculation of two real 10 kV power distribution line, the new method is practical and accurate. The results show that indirect strokes are the main cause of lightning trip out, and for analyzing the lightning performance of overhead power distribution lines, the indirect lightning must be taken into consideration.%雷电活动直接影响到架空电力线路的安全稳定运行,为全面分析架空配电线路的雷害问题,提出了一种计入地形条件影响的分析新方法.先基于雷电的击距理论建立架空配电线路的引雷模型,结合雷电流的概率密度函数,求出了线路在不同高度和不同地形条件下的引雷范围与线路高度呈非线性关系;在确定线路引雷范围的基础上,分别计算了我国不同地域的架空线路直接雷击跳闸率;在对Rusck感应雷过电压研究成果分析的基础上,利用广义积分法得出了不同地形和地域的感应雷击跳闸率计算公式,而且架空配电线路中感应雷击跳闸次数占总雷击跳闸次数能达到83%,在架空线路的防雷分析中应该计入感应雷击的影响.2条10 kV架空线路算例与实际运行情况的对比验证了该计算方法的正确性.

  10. FGMOS Based Voltage-Controlled Grounded Resistor

    Directory of Open Access Journals (Sweden)

    R. Pandey

    2010-09-01

    Full Text Available This paper proposes a new floating gate MOSFET (FGMOS based voltage-controlled grounded resistor. In the proposed circuit FGMOS operating in the ohmic region is linearized by another conventional MOSFET operating in the saturation region. The major advantages of FGMOS based voltage-controlled grounded resistor (FGVCGR are simplicity, low total harmonic distortion (THD, and low power consumption. A simple application of this FGVCGR as a tunable high-pass filter is also suggested. The proposed circuits operate at the supply voltages of +/-0.75 V. The circuits are designed and simulated using SPICE in 0.25-µm CMOS technology. The simulation results of FGVCGR demonstrate a THD of 0.28% for the input signal 0.32 Vpp at 45 kHz, and a maximum power consumption of 254 µW.

  11. Power module assembly

    Science.gov (United States)

    Campbell, Jeremy B [Torrance, CA; Newson, Steve [Redondo Beach, CA

    2011-11-15

    A power module assembly of the type suitable for deployment in a vehicular power inverter, wherein the power inverter has a grounded chassis, is provided. The power module assembly comprises a conductive base layer electrically coupled to the chassis, an insulating layer disposed on the conductive base layer, a first conductive node disposed on the insulating layer, a second conductive node disposed on the insulating layer, wherein the first and second conductive nodes are electrically isolated from each other. The power module assembly also comprises a first capacitor having a first electrode electrically connected to the conductive base layer, and a second electrode electrically connected to the first conductive node, and further comprises a second capacitor having a first electrode electrically connected to the conductive base layer, and a second electrode electrically connected to the second conductive node.

  12. Coding Issues in Grounded Theory

    Science.gov (United States)

    Moghaddam, Alireza

    2006-01-01

    This paper discusses grounded theory as one of the qualitative research designs. It describes how grounded theory generates from data. Three phases of grounded theory--open coding, axial coding, and selective coding--are discussed, along with some of the issues which are the source of debate among grounded theorists, especially between its…

  13. Coding Issues in Grounded Theory

    Science.gov (United States)

    Moghaddam, Alireza

    2006-01-01

    This paper discusses grounded theory as one of the qualitative research designs. It describes how grounded theory generates from data. Three phases of grounded theory--open coding, axial coding, and selective coding--are discussed, along with some of the issues which are the source of debate among grounded theorists, especially between its…

  14. Ground Truth Collections at the MTI Core Sites

    Energy Technology Data Exchange (ETDEWEB)

    Garrett, A.J.

    2001-01-25

    The Savannah River Technology Center (SRTC) selected 13 sites across the continental US and one site in the western Pacific to serve as the primary or core site for collection of ground truth data for validation of MTI science algorithms. Imagery and ground truth data from several of these sites are presented in this paper. These sites are the Comanche Peak, Pilgrim and Turkey Point power plants, Ivanpah playas, Crater Lake, Stennis Space Center and the Tropical Western Pacific ARM site on the island of Nauru. Ground truth data includes water temperatures (bulk and skin), radiometric data, meteorological data and plant operating data. The organizations that manage these sites assist SRTC with its ground truth data collections and also give the MTI project a variety of ground truth measurements that they make for their own purposes. Collectively, the ground truth data from the 14 core sites constitute a comprehensive database for science algorithm validation.

  15. DVE: ground and airborne visualization functionalities

    Science.gov (United States)

    Barratt, Nick; Mise, Olegs; Franklin, Dustin; Preece, Andy; Schaffer, Larry

    2014-06-01

    This paper describes functional blocks (hardware and software functionalities) applicable to several forms of indirect vision enhancement in DVE (Degraded Vision Environment for pilotage, Driver's Vision Enhancement for ground vehicle Situational Awareness). These functionalities are the result of the increased processing power of General Purpose Graphics Processing Units (GPGPUs) and improvements in mosaic stitch processing, image fusion and analytics of both live and synthetic imagery. We deploy GPUs into low-latency embedded systems with decreased SWaP (Size, Weight and Power) and high-bandwidth interconnectivity via RDMA (Remote Direct Memory Access).

  16. Power as a structural phenomenon.

    Science.gov (United States)

    Neal, Jennifer Watling; Neal, Zachary P

    2011-12-01

    In an effort to inform empowerment theory and research, this paper provides a structural conception of power. First, we examine the essential features present in three dominant conceptions of power in community psychology: social power, psychopolitical power, and relational power. Next, commonalities in the key features of power identified by these conceptions are explored and pared down to yield a more parsimonious conception of power that is grounded only in the structural pattern of relationships through which resources are exchanged. Drawing on social exchange theory, we offer a method for measuring this streamlined, structural conception of power that allows for its more precise examination. Finally, we discuss the implications of a structural conception and measurement of power for targeting and facilitating empowering processes and evaluating empowered outcomes.

  17. Mechanics of Ship Grounding

    DEFF Research Database (Denmark)

    Pedersen, Preben Terndrup

    1996-01-01

    In these notes first a simplified mathematical model is presented for analysis of ship hull loading due to grounding on relatively hard and plane sand, clay or rock sea bottoms. In a second section a more rational calculation model is described for the sea bed soil reaction forces on the sea bottom...

  18. Grounding Anger Management

    Directory of Open Access Journals (Sweden)

    Odis E. Simmons, PhD

    2017-06-01

    Full Text Available One of the things that drew me to grounded theory from the beginning was Glaser and Strauss’ assertion in The Discovery of Grounded Theory that it was useful as a “theoretical foothold” for practical applications (p. 268. From this, when I was a Ph.D student studying under Glaser and Strauss in the early 1970s, I devised a GT based approach to action I later came to call “grounded action.” In this short paper I’ll present a very brief sketch of an anger management program I developed in 1992, using grounded action. I began my research by attending a two-day anger management training workshop designed for training professionals in the most commonly used anger management model. Like other intervention programs I had seen, this model took a psychologizing and pathologizing approach to the issue. Following this, I sat through the full course of an anger management program that used this model, observing the reactions of the participants and the approach of the facilitator. Following each session I conducted open-ended interviews with most of the participants, either individually or in groups of two or three. I had also done previous research in counseling and social work contexts that turned out to be very relevant to an anger management program design.

  19. Grounding in Instant Messaging

    Science.gov (United States)

    Fox Tree, Jean E.; Mayer, Sarah A.; Betts, Teresa E.

    2011-01-01

    In two experiments, we investigated predictions of the "collaborative theory of language use" (Clark, 1996) as applied to instant messaging (IM). This theory describes how the presence and absence of different grounding constraints causes people to interact differently across different communicative media (Clark & Brennan, 1991). In Study 1, we…

  20. Informed Grounded Theory

    Science.gov (United States)

    Thornberg, Robert

    2012-01-01

    There is a widespread idea that in grounded theory (GT) research, the researcher has to delay the literature review until the end of the analysis to avoid contamination--a dictum that might turn educational researchers away from GT. Nevertheless, in this article the author (a) problematizes the dictum of delaying a literature review in classic…

  1. TARDEC Ground Vehicle Robotics

    Science.gov (United States)

    2013-05-30

    UNCLASSIFIED UNCLASSIFIED 10 Optionally Manned Vehicles OMV can be driven by a soldier; OMV can drive a soldier; OMV can be remotely operated; OMV can be...all missions for OMV (i.e. shared driving) (i.e. remotely operated) 2 m od al iti es Mission Payloads UNCLASSIFIED UNCLASSIFIED 11 Ground

  2. 30 CFR 56.12053 - Circuits powered from trolley wires.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Circuits powered from trolley wires. 56.12053... § 56.12053 Circuits powered from trolley wires. Ground wires for lighting circuits powered from trolley wires shall be connected securely to the ground-return circuit....

  3. 30 CFR 57.12053 - Circuits powered from trolley wires.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Circuits powered from trolley wires. 57.12053... Electricity Surface and Underground § 57.12053 Circuits powered from trolley wires. Ground wires for lighting circuits powered from trolley wires shall be connected securely to the ground return circuit. Surface Only...

  4. CTA telescopes as deep-space lasercom ground receivers

    CERN Document Server

    Carrasco-Casado, Alberto; Vergaz, Ricardo

    2015-01-01

    The amount of scientific data to be transmitted from deep-space probes is very limited due to RF-communications constraints. Free-space optical communication can alleviate this bottleneck, increasing data rate while reducing weight, mass and power of communication onboard equipment. Nevertheless, optimizing the power delivery from spacecraft to Earth is needed. In RF communications, the strategy has been to increase the aperture of ground terminals. Free-space optical communications can also follow it, as they share the limitation of low power received on Earth. As the cost of big telescopes increases exponentially with aperture, new ideas are required to maximize the aperture-to-cost ratio. This work explores the feasibility of using telescopes of the future Cherenkov Telescope Array as optical-communication ground stations. Ground-based gamma-ray astronomy has the same power limitation, hence Cherenkov telescopes are designed to maximize receiver's aperture with minimum cost and some relaxed requirements. B...

  5. Influences of Grounding Site Soil Parameters on Earth Surface Potential of the High-voltage Interconnected Power Grid%高压互联电网极址土层参数对直流地表电位影响的研究

    Institute of Scientific and Technical Information of China (English)

    吴超; 吴广宁; 范建斌; 任志超; 张一坤

    2011-01-01

    HVDC接地极极址选择、布置形式和地表电位的分布在很大程度上取决于土壤结构模型,对分析HVDC输电系统单极运行时交流网络受到的影响也有重要作用.笔者利用CDEGS软件对HVDC系统及交流输电网络进行建模仿真,采用不同的土壤模型,分析研究了直流输电系统以单极大地回线方式运行时,各层土壤参数对地表电位分布的影响.仿真结果表明:直流地表电位因距离接地极的远近而不同,距离接地极越远,直流地表电位绝对值越小,近似呈指数函数形式衰减;直流地表电位数值与土壤厚度近似成反比,而与表层土壤电阻率近似成正比:土壤模型及参数的选取极大地影响了地表电位仿真计算的准确性及真实性,需综合考虑计算结果的精度要求和计算过程难易程度.%The HVDC grounding site selection, ground electrode design, and earth surface potential (ESP)distribution mainly depend on soil model, which is of great importance to analyze the influence of HVDC mono-polar operation with ground return on AC power grid. In this paper, the characteristics of the ESP under DC mono-polar operation mode were summarized with the software CEDGS according to the analysis of different soil models and variable soil parameters. The simulation results illustrate that the farther it is from the grounding site, the smaller the absolute value of ESP is with exponential attenuation. ESP shows approximately inverse proportion to soil thickness but direct proportion to resistivity of surface soil.Selections of soil model and its parameters exert significant influence on accuracy of ESP simulation,therefore the balance between accuracy and difficulty of calculation ought to be considered.

  6. A Comparative Parametric Analysis of the Ground Fault Current Distribution on Overhead Transmission Lines

    Directory of Open Access Journals (Sweden)

    VINTAN, M.

    2016-02-01

    Full Text Available The ground fault current distribution in an effectively grounded power network is affected by various factors, such as: tower footing impedances, spans lengths, configuration and parameters of overhead ground wires and power conductors, soil resistivity etc. In this paper, we comparatively analyze, using different models, the ground fault current distribution in a single circuit transmission line with one ground wire. A parametric comparative analysis was done in order to study the effects of the non-uniformity of the towers footing impedances, number of power lines spans, soil resistivity, grounding systems resistances of the terminal substations etc., on the ground fault current distribution. There are presented some useful qualitative and quantitative results obtained through a complex dedicated developed MATLAB 7.0 program.

  7. Infrasonic induced ground motions

    Science.gov (United States)

    Lin, Ting-Li

    On January 28, 2004, the CERI seismic network recorded seismic signals generated by an unknown source. Our conclusion is that the acoustic waves were initiated by an explosive source near the ground surface. The meteorological temperature and effective sound speed profiles suggested existence of an efficient near-surface waveguide that allowed the acoustic disturbance to propagate to large distances. An explosion occurring in an area of forest and farms would have limited the number of eyewitnesses. Resolution of the source might be possible by experiment or by detailed analysis of the ground motion data. A seismo-acoustic array was built to investigate thunder-induced ground motions. Two thunder events with similar N-wave waveforms but different horizontal slownesses are chosen to evaluate the credibility of using thunder as a seismic source. These impulsive acoustic waves excited P and S reverberations in the near surface that depend on both the incident wave horizontal slowness and the velocity structure in the upper 30 meters. Nineteen thunder events were chosen to further investigate the seismo-acoustic coupling. The consistent incident slowness differences between acoustic pressure and ground motions suggest that ground reverberations were first initiated somewhat away from the array. Acoustic and seismic signals were used to generate the time-domain transfer function through the deconvolution technique. Possible non-linear interaction for acoustic propagation into the soil at the surface was observed. The reverse radial initial motions suggest a low Poisson's ratio for the near-surface layer. The acoustic-to-seismic transfer functions show a consistent reverberation series of the Rayleigh wave type, which has a systematic dispersion relation to incident slownesses inferred from the seismic ground velocity. Air-coupled Rayleigh wave dispersion was used to quantitatively constrain the near-surface site structure with constraints afforded by near-surface body

  8. Decentralized Ground Staff Scheduling

    DEFF Research Database (Denmark)

    Sørensen, M. D.; Clausen, Jens

    2002-01-01

    Typically, ground staff scheduling is centrally planned for each terminal in an airport. The advantage of this is that the staff is efficiently utilized, but a disadvantage is that staff spends considerable time walking between stands. In this paper a decentralized approach for ground staff...... scheduling is investigated. The airport terminal is divided into zones, where each zone consists of a set of stands geographically next to each other. Staff is assigned to work in only one zone and the staff scheduling is planned decentralized for each zone. The advantage of this approach is that the staff...... work in a smaller area of the terminal and thus spends less time walking between stands. When planning decentralized the allocation of stands to flights influences the staff scheduling since the workload in a zone depends on which flights are allocated to stands in the zone. Hence solving the problem...

  9. Ibis ground calibration

    Energy Technology Data Exchange (ETDEWEB)

    Bird, A.J.; Barlow, E.J.; Tikkanen, T. [Southampton Univ., School of Physics and Astronomy (United Kingdom); Bazzano, A.; Del Santo, M.; Ubertini, P. [Istituto di Astrofisica Spaziale e Fisica Cosmica - IASF/CNR, Roma (Italy); Blondel, C.; Laurent, P.; Lebrun, F. [CEA Saclay - Sap, 91 - Gif sur Yvette (France); Di Cocco, G.; Malaguti, E. [Istituto di Astrofisica Spaziale e Fisica-Bologna - IASF/CNR (Italy); Gabriele, M.; La Rosa, G.; Segreto, A. [Istituto di Astrofisica Spaziale e Fisica- IASF/CNR, Palermo (Italy); Quadrini, E. [Istituto di Astrofisica Spaziale e Fisica-Cosmica, EASF/CNR, Milano (Italy); Volkmer, R. [Institut fur Astronomie und Astrophysik, Tubingen (Germany)

    2003-11-01

    We present an overview of results obtained from IBIS ground calibrations. The spectral and spatial characteristics of the detector planes and surrounding passive materials have been determined through a series of calibration campaigns. Measurements of pixel gain, energy resolution, detection uniformity, efficiency and imaging capability are presented. The key results obtained from the ground calibration have been: - optimization of the instrument tunable parameters, - determination of energy linearity for all detection modes, - determination of energy resolution as a function of energy through the range 20 keV - 3 MeV, - demonstration of imaging capability in each mode, - measurement of intrinsic detector non-uniformity and understanding of the effects of passive materials surrounding the detector plane, and - discovery (and closure) of various leakage paths through the passive shielding system.

  10. Mechanics of Ship Grounding

    DEFF Research Database (Denmark)

    Pedersen, Preben Terndrup

    1996-01-01

    In these notes first a simplified mathematical model is presented for analysis of ship hull loading due to grounding on relatively hard and plane sand, clay or rock sea bottoms. In a second section a more rational calculation model is described for the sea bed soil reaction forces on the sea bottom....... Finally, overall hull failure is considered first applying a quasistatic analysis model and thereafter a full dynamic model....

  11. Outdoor ground impedance models.

    Science.gov (United States)

    Attenborough, Keith; Bashir, Imran; Taherzadeh, Shahram

    2011-05-01

    Many models for the acoustical properties of rigid-porous media require knowledge of parameter values that are not available for outdoor ground surfaces. The relationship used between tortuosity and porosity for stacked spheres results in five characteristic impedance models that require not more than two adjustable parameters. These models and hard-backed-layer versions are considered further through numerical fitting of 42 short range level difference spectra measured over various ground surfaces. For all but eight sites, slit-pore, phenomenological and variable porosity models yield lower fitting errors than those given by the widely used one-parameter semi-empirical model. Data for 12 of 26 grassland sites and for three beech wood sites are fitted better by hard-backed-layer models. Parameter values obtained by fitting slit-pore and phenomenological models to data for relatively low flow resistivity grounds, such as forest floors, porous asphalt, and gravel, are consistent with values that have been obtained non-acoustically. Three impedance models yield reasonable fits to a narrow band excess attenuation spectrum measured at short range over railway ballast but, if extended reaction is taken into account, the hard-backed-layer version of the slit-pore model gives the most reasonable parameter values.

  12. 30 CFR 75.825 - Power centers.

    Science.gov (United States)

    2010-07-01

    ..., de-energizes input to all power transformers. (b) Trailing cable disconnecting device. In addition to... circuit to the power center. (g) Emergency stop switch. The power center must be equipped with an externally accessible emergency stop switch hard-wired into the incoming ground-wire monitor circuit that de...

  13. Power Outages

    Science.gov (United States)

    ... Thunderstorms & Lightning Tornadoes Tsunamis Volcanoes Wildfires Main Content Power Outages This page provides basic safety tips and ... during and after a power outage. Before a Power Outage Build or restock your emergency preparedness kit , ...

  14. Identification of resonant earthquake ground motion

    Indian Academy of Sciences (India)

    Abbas Moustafa

    2010-06-01

    Resonant ground motion has been observed in earthquake records measured at several parts of the world. This class of ground motion is characterized by its energy being contained in a narrow frequency band. This paper develops measures to quantify the frequency content of the ground motion using the entropy principle and the dispersion index. These measures are based on the geometric properties of the power spectral density function of the ground acceleration. The application of these measures to quantify the frequency content of random earthquake models is demonstrated first. Subsequently, these measures are used to quantify the frequency content of the ground acceleration for near-field records measured at rock and soil sites, short-duration and long-duration earthquakes.

  15. Dynasting Theory: Lessons in learning grounded theory

    Directory of Open Access Journals (Sweden)

    Johnben Teik-Cheok Loy, MBA, MTS, Ph.D.

    2011-06-01

    Full Text Available This article captures the key learning lessons gleaned from the author’s experience learning and developing a grounded theory for his doctoral dissertation using the classic methodology as conceived by Barney Glaser. The theory was developed through data gathered on founders and successors of Malaysian Chinese family-own businesses. The main concern for Malaysian Chinese family businesses emerged as dynasting . the building, maintaining, and growing the power and resources of the business within the family lineage. The core category emerged as dynasting across cultures, where founders and successors struggle to transition from traditional Chinese to hybrid cultural and modernized forms of family business from one generation to the next. The key learning lessons were categorized under five headings: (a sorting through different versions of grounded theory, (b educating and managing research stakeholders, (c embracing experiential learning, (d discovering the core category: grounded intuition, and (e recognizing limitations and possibilities.Keywords: grounded theory, learning, dynasting, family business, Chinese

  16. Wind Power

    OpenAIRE

    Makhalas, Kharsan Al; Alsehlli, Faisal

    2015-01-01

    This Bachelor thesis has been written at the Blekinge Institute of Technology. This thesis concentrates on the wind power and their components, also the large wind farm is studied. The electrical power is generated by using the power in wind to drive a wind turbine to produce mechanical power. This mechanical power can be converted into electrical power by using electrical induction generators. There are two types of the wind turbines, the horizontal axis and vertical axis wind turbine, where...

  17. Common Ground and Delegation

    DEFF Research Database (Denmark)

    Dobrajska, Magdalena; Foss, Nicolai Juul; Lyngsie, Jacob

    Much recent research suggests that firms need to increase their level of delegation to better cope with, for example, the challenges introduced by dynamic rapid environments and the need to engage more with external knowledge sources. However, there is less insight into the organizational...... preconditions of increasing delegation. We argue that key HR practices?namely, hiring, training and job-rotation?are associated with delegation of decision-making authority. These practices assist in the creation of shared knowledge conditions between managers and employees. In turn, such a ?common ground...

  18. Ground penetrating radar

    CERN Document Server

    Daniels, David J

    2004-01-01

    Ground-penetrating radar has come to public attention in recent criminal investigations, but has actually been a developing and maturing remote sensing field for some time. In the light of recent expansion of the technique to a wide range of applications, the need for an up-to-date reference has become pressing. This fully revised and expanded edition of the best-selling Surface-Penetrating Radar (IEE, 1996) presents, for the non-specialist user or engineer, all the key elements of this technique, which span several disciplines including electromagnetics, geophysics and signal processing. The

  19. Singlet Ground State Magnetism:

    DEFF Research Database (Denmark)

    Loidl, A.; Knorr, K.; Kjems, Jørgen;

    1979-01-01

    The magneticGamma 1 –Gamma 4 exciton of the singlet ground state system TbP has been studied by inelastic neutron scattering above the antiferromagnetic ordering temperature. Considerable dispersion and a pronounced splitting was found in the [100] and [110] directions. Both the band width...... and the splitting increased rapidly as the transition temperature was approached in accordance with the predictions of the RPA-theory. The dispersion is analysed in terms of a phenomenological model using interactions up to the fourth nearest neighbour....

  20. The LOFT Ground Segment

    DEFF Research Database (Denmark)

    Bozzo, E.; Antonelli, A.; Argan, A.;

    2014-01-01

    targets per orbit (~90 minutes), providing roughly ~80 GB of proprietary data per day (the proprietary period will be 12 months). The WFM continuously monitors about 1/3 of the sky at a time and provides data for about ~100 sources a day, resulting in a total of ~20 GB of additional telemetry. The LOFT...... we summarize the planned organization of the LOFT ground segment (GS), as established in the mission Yellow Book 1 . We describe the expected GS contributions from ESA and the LOFT consortium. A review is provided of the planned LOFT data products and the details of the data flow, archiving...

  1. Pragmatic power

    CERN Document Server

    Eccles, William

    2008-01-01

    Pragmatic Power is focused on just three aspects of the AC electrical power system that supplies and moves the vast majority of electrical energy nearly everywhere in the world: three-phase power systems, transformers, and induction motors. The reader needs to have had an introduction to electrical circuits and AC power, although the text begins with a review of the basics of AC power. Balanced three-phase systems are studied by developing their single-phase equivalents. The study includes a look at how the cost of ""power"" is affected by reactive power and power factor. Transformers are cons

  2. Eliminating Ground Current in a Transformerless Photovoltaic Application

    DEFF Research Database (Denmark)

    Lopez, Ocar; Freijedo, Francisco D.; Yepes, Alejandro G.

    2010-01-01

    For low-power grid-connected applications, a singlephase converter can be used. In photovoltaic (PV) applications, it is possible to remove the transformer in the inverter to reduce losses, costs, and size. Galvanic connection of the grid and the dc sources in transformerless systems can introduce...... additional ground currents due to the ground parasitic capacitance. These currents increase conducted and radiated electromagnetic emissions, harmonics injected in the utility grid, and losses. Amplitude and spectrum of the ground current depend on the converter topology, the switching strategy...

  3. Ground and air resonance of bearingless rotors in hover

    Science.gov (United States)

    Jang, Jinseok; Chopra, Inderjit

    1987-01-01

    A finite element formulation is used to investigate ground and air resistence in hover for a bearingless rotor. Aerodynamic forces are studied using quasi-steady strip theory, and unsteady aerodynamic effects are introduced through an inflow dynamics model. Reasonable correlation was found between predicted ground and air resonance results and data obtained from measurements using a 1/8th Froude-scaled dynamic model. Systematic parametric studies of the effects of various design parameters were performed, and lag frequency was found to significantly influence ground resonance stability, whereas pitch-lag coupling, blade sweep and pitch link stiffness had powerful effects on air resonance stability.

  4. Radiation Tolerant Low Power Precision Time Source Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The availability of small, low power atomic clocks is now a reality for ground-based and airborne navigation systems. Kernco's Low Power Precision Time Source...

  5. 47 CFR 22.867 - Effective radiated power limits.

    Science.gov (United States)

    2010-10-01

    ... Effective radiated power limits. The effective radiated power (ERP) of ground and airborne stations... peak ERP of airborne mobile station transmitters must not exceed 12 Watts. (b) The peak ERP of...

  6. The LOFT Ground Segment

    CERN Document Server

    Bozzo, E; Argan, A; Barret, D; Binko, P; Brandt, S; Cavazzuti, E; Courvoisier, T; Herder, J W den; Feroci, M; Ferrigno, C; Giommi, P; Götz, D; Guy, L; Hernanz, M; Zand, J J M in't; Klochkov, D; Kuulkers, E; Motch, C; Lumb, D; Papitto, A; Pittori, C; Rohlfs, R; Santangelo, A; Schmid, C; Schwope, A D; Smith, P J; Webb, N A; Wilms, J; Zane, S

    2014-01-01

    LOFT, the Large Observatory For X-ray Timing, was one of the ESA M3 mission candidates that completed their assessment phase at the end of 2013. LOFT is equipped with two instruments, the Large Area Detector (LAD) and the Wide Field Monitor (WFM). The LAD performs pointed observations of several targets per orbit (~90 minutes), providing roughly ~80 GB of proprietary data per day (the proprietary period will be 12 months). The WFM continuously monitors about 1/3 of the sky at a time and provides data for about ~100 sources a day, resulting in a total of ~20 GB of additional telemetry. The LOFT Burst alert System additionally identifies on-board bright impulsive events (e.g., Gamma-ray Bursts, GRBs) and broadcasts the corresponding position and trigger time to the ground using a dedicated system of ~15 VHF receivers. All WFM data are planned to be made public immediately. In this contribution we summarize the planned organization of the LOFT ground segment (GS), as established in the mission Yellow Book 1 . We...

  7. Grounding and shielding circuits and interference

    CERN Document Server

    Morrison, Ralph

    2016-01-01

    Applies basic field behavior in circuit design and demonstrates how it relates to grounding and shielding requirements and techniques in circuit design This book connects the fundamentals of electromagnetic theory to the problems of interference in all types of electronic design. The text covers power distribution in facilities, mixing of analog and digital circuitry, circuit board layout at high clock rates, and meeting radiation and susceptibility standards. The author examines the grounding and shielding requirements and techniques in circuit design and applies basic physics to circuit behavior. The sixth edition of this book has been updated with new material added throughout the chapters where appropriate. The presentation of the book has also been rearranged in order to reflect the current trends in the field.

  8. The Rover Environmental Monitoring Station Ground Temperature Sensor: A Pyrometer for Measuring Ground Temperature on Mars

    OpenAIRE

    2010-01-01

    We describe the parameters that drive the design and modeling of the Rover Environmental Monitoring Station (REMS) Ground Temperature Sensor (GTS), an instrument aboard NASA’s Mars Science Laboratory, and report preliminary test results. REMS GTS is a lightweight, low-power, and low cost pyrometer for measuring the Martian surface kinematic temperature. The sensor’s main feature is its innovative design, based on a simple mechanical structure with no moving parts. It includes an in-flight cal...

  9. Reducing Magnetic Fields Around Power Cables

    Science.gov (United States)

    Sargent, Noel B.; Gitelman, Florida; Pongracz-Bartha, Edward; Spalding, John

    1993-01-01

    Four power conductors arranged symmetrically about fifth grounded conductor. Four current-carrying wires arranged symmetrically around central grounded wire that nominally carries no current. In comparison with other cable configurations, this one results in smaller magnetic fields around cable. Technique for use when size of wires in cable makes twisting impractical.

  10. Unmanned Ground Systems Roadmap

    Science.gov (United States)

    2011-07-01

    Squad Mission Support System SOC .............................. Special Operations Command SOFC ............................ Solid Oxide Fuel Cell ...technologies may be used to match a given Use Profile: Table 5. Power Use Profiles Energy Storage Energy Harvesting Fuel Cells Engines Lead Acid...significant amount of research and development in both Government and Industry have been devoted to the areas of energy storage, fuel cells , and small

  11. Development Ground Fault Detecting System for D.C Voltage Line

    Energy Technology Data Exchange (ETDEWEB)

    Kim Taek Soo; Song Ung Il; Gwon, Young Dong; Lee Hyoung Kee [Korea Electric Power Research Institute, Taejon (Korea, Republic of)

    1996-12-31

    It is necessary to keep the security of reliability and to maximize the efficiency of maintenance by prompt detection of a D.C feeder ground fault point at the built ed or a building power plants. At present, the most of the power plants are set up the ground fault indicator lamp in the monitor room. If a ground fault occurs on DC voltage feeder, a current through the ground fault relay is adjusted and the lamps have brightened while the current flows the relay coil. In order to develop such a system, it is analyzed a D.C feeder ground circuit theoretically and studied a principles which can determine ground fault point or a polarity discrimination and a phase discrimination of the line. So, the developed system through this principles can compute a resistance ground fault current and a capacitive ground fault current. It shows that the system can defect a ground fault point or a bad insulated line by measuring a power plant D.C feeder insulation resistance at the un interruptible power status, and therefore the power plant could protect an unexpected service interruption . (author). 18 refs., figs.

  12. 基于扎根理论的科技型中小企业成长衍生扩散内生动力研究%Research on the SME Growth Derived the Endogenous Power Spread Based on Grounded Theory

    Institute of Scientific and Technical Information of China (English)

    王丽平; 钱周春; 梁晓琴

    2013-01-01

    科技型中小企业的发展受内生动力和外部环境的共同影响,其中内生动力是科技型中小企业成长衍生扩散的基础和根本.运用扎根理论,对天地伟业数码科技有限公司成长衍生扩散的内生动力进行案例调查与研究,得出科技型中小企业成长衍生扩散四个方面的内生动力,即企业家能力、技术创新能力、企业管理制度和市场营销能力,为其它科技型中小企业成长衍生扩散提供经验参考.%The SMEs,development mainly by the power and external environments of the endogenous joint process in which the endogenous driving force is SME derived the foundation and fundamental diffusion. This paper uses the method of grounded theory to investigate and research the case of Tiandy Digital Technology Co. LTD Growth derived diffusion. In the case of the growth of enterprise research derivative diffusion process, that SMEs obtained four aspects the endogenous power, namely entrepreneurs ability, the technical innovation ability, the enterprise management system and market marketing capabilities, it can Provide experience of reference for other tech SMEs derivative diffusion.

  13. Designing as middle ground

    DEFF Research Database (Denmark)

    Nickelsen, Niels Christian Mossfeldt; Binder, Thomas

    2010-01-01

    The theoretical background in this chapter is science and technology studies and actor network theory, enabling investigation of heterogeneity, agency and perfor-mative effects through ‘symmetric’ analysis. The concept of design is defined as being imaginative and mindful to a number of actors...... in a network of humans and non-humans, highlighting that design objects and the designer as an authority are constructed throughout this endeavour. The illustrative case example is drawn from product development in a rubber valve factory in Jutland in Denmark. The key contribution to a general core of design...... research is an articulation of design activity taking place as a middle ground and as an intermixture between a ‘scientific’ regime of knowledge transfer and a capital ‘D’ ‘Designerly’ regime of authoring....

  14. Simulation of ground motion using the stochastic method

    Science.gov (United States)

    Boore, D.M.

    2003-01-01

    A simple and powerful method for simulating ground motions is to combine parametric or functional descriptions of the ground motion's amplitude spectrum with a random phase spectrum modified such that the motion is distributed over a duration related to the earthquake magnitude and to the distance from the source. This method of simulating ground motions often goes by the name "the stochastic method." It is particularly useful for simulating the higher-frequency ground motions of most interest to engineers (generally, f>0.1 Hz), and it is widely used to predict ground motions for regions of the world in which recordings of motion from potentially damaging earthquakes are not available. This simple method has been successful in matching a variety of ground-motion measures for earthquakes with seismic moments spanning more than 12 orders of magnitude and in diverse tectonic environments. One of the essential characteristics of the method is that it distills what is known about the various factors affecting ground motions (source, path, and site) into simple functional forms. This provides a means by which the results of the rigorous studies reported in other papers in this volume can be incorporated into practical predictions of ground motion.

  15. Wind-induced ground motion

    Science.gov (United States)

    Naderyan, Vahid; Hickey, Craig J.; Raspet, Richard

    2016-02-01

    Wind noise is a problem in seismic surveys and can mask the seismic signals at low frequency. This research investigates ground motions caused by wind pressure and shear stress perturbations on the ground surface. A prediction of the ground displacement spectra using the measured ground properties and predicted pressure and shear stress at the ground surface is developed. Field measurements are conducted at a site having a flat terrain and low ambient seismic noise. Triaxial geophones are deployed at different depths to study the wind-induced ground vibrations as a function of depth and wind velocity. Comparison of the predicted to the measured wind-induced ground displacement spectra shows good agreement for the vertical component but significant underprediction for the horizontal components. To validate the theoretical model, a test experiment is designed to exert controlled normal pressure and shear stress on the ground using a vertical and a horizontal mass-spring apparatus. This experiment verifies the linear elastic rheology and the quasi-static displacements assumptions of the model. The results indicate that the existing surface shear stress models significantly underestimate the wind shear stress at the ground surface and the amplitude of the fluctuation shear stress must be of the same order of magnitude as the normal pressure. Measurement results show that mounting the geophones flush with the ground provides a significant reduction in wind noise on all three components of the geophone. Further reduction in wind noise with depth of burial is small for depths up to 40 cm.

  16. Ground Vehicle Power and Mobility (GVPM) Powertrain Overview

    Science.gov (United States)

    2011-08-11

    Transmission Multi K Factor Torque converter Powertrain Control and ECM Hardware Development Military Vehicle Fuel Economy Measurement Cycle...Military Engine Optimization Efficiency Gap Transmission -No Torque Converter - Multi-Cone clutches - Wide-spread, equally progressive gear ratios...advanced controls algorithms. • Improved torque capacity, better speed/load matching, reduced thermal loading, and improved control strategy for

  17. Wind power in power systems

    CERN Document Server

    Ackermann, Thomas

    2012-01-01

    The second edition of the highly acclaimed Wind Power in Power Systems has been thoroughly revised and expanded to reflect the latest challenges associated with increasing wind power penetration levels. Since its first release, practical experiences with high wind power penetration levels have significantly increased. This book presents an overview of the lessons learned in integrating wind power into power systems and provides an outlook of the relevant issues and solutions to allow even higher wind power penetration levels. This includes the development of standard wind turbine sim

  18. Power Electronics

    DEFF Research Database (Denmark)

    Iov, Florin; Ciobotaru, Mihai; Blaabjerg, Frede

    2008-01-01

    energy at the end-user should also be set up. Deregulation of energy has in the past lowered the investment in larger power plants, which means the need for new electrical power sources will be high in the near future. Two major technologies will play important roles to solve the future problems. One...... is to change the electrical power production sources from the conventional, fossil (and short term) based energy sources to renewable energy resources. The other is to use high efficient power electronics in power generation, power transmission/distribution and end-user application. This paper discuss the most...... emerging renewable energy sources, wind energy, which by means of power electronics are changing from being a minor energy source to be acting as an important power source in the energy system. Power electronics is the enabling technology and the presentation will cover the development in wind turbine...

  19. Bolster Ground Force Capabilities in the Asia-Pacific Region

    Science.gov (United States)

    2016-05-12

    Defense, China is “exploiting a power vacuum [in Asia ] with a Cold War mindset. It is tilting the balance of power in its favor against weak...NAVAL WAR COLLEGE Newport, R.I. BOLSTER GROUND FORCE CAPABILITIES IN THE ASIA -PACIFIC REGION by Bryan Dunker Major, United States Army...created them.” – Albert Einstein INTRODUCTION Following the collapse of the Soviet Union and the end of the Cold War in 1991, the United States

  20. Localizing Ground-Penetrating Radar

    Science.gov (United States)

    2014-11-01

    ing Ground-Penetrating Radar (LGPR) uses very high frequency (VHF) radar reflections of underground features to generate base- line maps and then...Innovative ground- penetrating radar that maps underground geological features provides autonomous vehicles with real-time localization. Localizing...NOV 2014 2. REPORT TYPE 3. DATES COVERED 00-00-2014 to 00-00-2014 4. TITLE AND SUBTITLE Localizing Ground-Penetrating Radar 5a. CONTRACT NUMBER

  1. Principle and Design of a Single-phase Inverter Based Grounding System for Neutral-to-ground Voltage Compensation in Distribution Networks

    DEFF Research Database (Denmark)

    Wang, Wen; Yan, Lingjie; Zeng, Xiangjun

    2017-01-01

    Neutral-to-ground overvoltage may occur in non-effectively grounded power systems because of the distributed parameters asymmetry and resonance between Petersen coil and distributed capacitances. Thus, the constraint of neutral-to-ground voltage is critical for the safety of distribution networks....... In this paper, an active grounding system based on single-phase inverter and its control parameter design method is proposed to achieve this objective. Relationship between its output current and neutral-to-ground voltage is derived to explain the principle of neutral-to-ground voltage compensation. Then...... margin subjecting to large range of load change. The PI method is taken as the comparative method and the performances of both control methods are presented in detail. Experimental results prove the effectiveness and novelty of the proposed grounding system and control method....

  2. Burial Ground Expansion Hydrogeologic Characterization

    Energy Technology Data Exchange (ETDEWEB)

    Gaughan , T.F.

    1999-02-26

    Sirrine Environmental Consultants provided technical oversight of the installation of eighteen groundwater monitoring wells and six exploratory borings around the location of the Burial Ground Expansion.

  3. Experimental Investigation of Rotorcraft Outwash in Ground Effect

    Science.gov (United States)

    Tanner, Philip E.; Overmeyer, Austin D.; Jenkins, Luther N.; Yao, Chung-Sheng; Bartram, Scott M.

    2015-01-01

    The wake characteristics of a rotorcraft are affected by the proximity of a rotor to the ground surface, especially during hover. Ground effect is encountered when the rotor disk is within a distance of a few rotor radii above the ground surface and results in an increase in thrust for a given power relative to that same power condition with the rotor out of ground effect. Although this phenomenon has been highly documented and observed since the beginning of the helicopter age, there is still a relatively little amount of flow-field data existing to help understand its features. Joint Army and NASA testing was conducted at NASA Langley Research Center using a powered rotorcraft model in hover at various rotor heights and thrust conditions in order to contribute to the complete outwash data set. The measured data included outwash velocities and directions, rotor loads, fuselage loads, and ground pressures. The researchers observed a linear relationship between rotor height and percent download on the fuselage, peak mean outwash velocities occurring at radial stations between 1.7 and 1.8 r/R regardless of rotor height, and the measurement azimuthal dependence of the outwash profile for a model incorporating a fuselage. Comparisons to phase-locked PIV data showed similar contours but a more contracted wake boundary for the PIV data. This paper describes the test setup and presents some of the averaged results.

  4. A Comparison Of A Solar Power Satellite Concept To A Concentrating Solar Power System

    Science.gov (United States)

    Smitherman, David V.

    2013-01-01

    A comparison is made of a Solar Power Satellite concept in geostationary Earth orbit to a Concentrating Solar Power system on the ground to analyze overall efficiencies of each infrastructure from solar radiance at 1 AU to conversion and transmission of electrical energy into the power grid on the Earth's surface. Each system is sized for a 1-gigawatt output to the power grid and then further analyzed to determine primary collector infrastructure areas. Findings indicate that even though the Solar Power Satellite concept has a higher end-to-end efficiency, that the combined space and ground collector infrastructure is still about the same size as a comparable Concentrating Solar Power system on the ground.

  5. Spacelab Ground Processing

    Science.gov (United States)

    Scully, Edward J.; Gaskins, Roger B.

    1982-02-01

    Spacelab (SL) ground processing is active at the Kennedy Space Center (KSC). The palletized payload for the second Shuttle launch is staged and integrated with interface verification active. The SL Engineering Model is being assembled for subsequent test and checkout activities. After delivery of SL flight elements from Europe, prelaunch operations for the first SL flight start with receipt of the flight experiment packages and staging of the SL hardware. Experiment operations consist of integrating the various experiment elements into the SL racks, floors and pallets. Rack and floor assemblies with the experiments installed, are integrated into the flight module. Aft end-cone installation, pallet connections, and SL subsystems interface verifications are accomplished, and SL-Orbiter interfaces verified. The Spacelab cargo is then transferred to the Orbiter Processing Facility (OPF) in a controlled environment using a canister/transporter. After the SL is installed into the Orbiter payload bay, physical and functional integrity of all payload-to-Orbiter interfaces are verified and final close-out operations conducted. Spacelab payload activities at the launch pad are minimal with the payload bay doors remaining closed. Limited access is available to the module through the Spacelab Transfer Tunnel. After mission completion, the SL is removed from the Orbiter in the OPF and returned to the SL processing facility for experiment equipment removal and reconfiguration for the subsequent mission.

  6. PALSAR ground data processing

    Science.gov (United States)

    Frick, Heinrich; Palsetia, Marzban; Carande, Richard; Curlander, James C.

    2002-02-01

    The upcoming launches of new satellites like ALOS, Envisat, Radarsat2 and ECHO will pose a significant challenge for many ground stations, namely to integrate new SAR processing software into their existing systems. Vexcel Corporation in Boulder, Colorado, has built a SAR processing system, named APEX -Suite, for spaceborne SAR satellites that can easily be expanded for the next generation of SAR satellites. APEX-Suite includes an auto-satellite-detecting Level 0 Processor that includes bit-error correction, data quality characterization, and as a unique feature, a sophisticated and very accurate Doppler centroid estimator. The Level 1 processing is divided into the strip mode processor FOCUST, based on the well-proven range-Doppler algorithm, and the SWATHT ScanSAR processor that uses the Chirp Z Trans-form algorithm. A high-accuracy ortho-rectification processor produces systematic and precision corrected Level 2 SAR image pro ducts. The PALSAR instrument is an L-band SAR with multiple fine and standard resolution beams in strip mode, and several wide-swath ScanSAR modes. We will address the adaptation process of Vexcel's APEX-Suite processing system for the PALSAR sensor and discuss image quality characteristics based on processed simulated point target phase history data.

  7. Electric Power

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ China Council for the Promotion of International Trade Electric Power Industry Office (CCPIT Electric Power), one of the pro-fessional industrial branches of China Council for the Promotion of International Trade (CCPIT), was established in 2006.

  8. Power Electronics

    DEFF Research Database (Denmark)

    Iov, Florin; Ciobotaru, Mihai; Blaabjerg, Frede

    2008-01-01

    is to change the electrical power production sources from the conventional, fossil (and short term) based energy sources to renewable energy resources. The other is to use high efficient power electronics in power generation, power transmission/distribution and end-user application. This paper discuss the most...... emerging renewable energy sources, wind energy, which by means of power electronics are changing from being a minor energy source to be acting as an important power source in the energy system. Power electronics is the enabling technology and the presentation will cover the development in wind turbine...... technology from kW to MW, discuss which power electronic solutions are most feasible and used today....

  9. Normative Power

    DEFF Research Database (Denmark)

    The social sciences have many different understandings of ‘normative power', but in European Union (EU) studies normative power has three particular meanings. The first meaning of normative power is its emphasis on normative theory, that is, how we judge and justify truth claims in social science....... The second meaning of normative power is as a form of power that is ideational rather than material or physical. The third meaning of normative power is as a characterisation of an ideal type of international actor. Empirical studies of normative forms of power have analysed both the causal and constitutive...... effects of EU relations with the world in areas ranging from inter-regional relations, through traditional diplomacy, to environmental politics. Research areas of particular interest include the study of the interplay between physical, material and normative forms of power, as well as the constitutive...

  10. Power Talk

    DEFF Research Database (Denmark)

    Angjelichinoski, Marko; Stefanovic, Cedomir; Popovski, Petar

    2016-01-01

    A standard way to realize communication in microgrid control is to use an external communication network, such as modems for wireless or power-line communication, whose implementation may be inefficient in terms of deployment cost, complexity, and system stability. In this chapter we present...... a communication solution, denoted as power talk, which is solely based on the use of the existing microgrid power equipment (i.e., power electronics and buses). The pivotal idea is to modulate information in the power-related parameters of the microgrid buses by use of the flexibility of power electronic...... interfaces. The focus of the chapter is on the design of power talk solutions for DC microgrids with droop control. Specifically, the chapter presents the power talk implementation through modification of the droop parameters of the primary control loop, and investigates the design of modulation schemes...

  11. Achievement of the best design for unequally spaced grounding grids

    Directory of Open Access Journals (Sweden)

    El-Sayed M. El-Refaie

    2015-03-01

    Also, unequal spacing can reduce the cost of the grids and enhance the level of safety for people and equipments. In this paper two different approaches were used to determine the best possible configuration of grounding grid. These approaches based on sequential multiplicative and sequential power techniques.

  12. Exploiting link dynamics in LEO-to-ground communications

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, Joseph Mcrae [Los Alamos National Laboratory; Caffrey, Michael P [Los Alamos National Laboratory

    2009-01-01

    The high dynamics of the LEO-to-ground radio channel are described. An analysis shows how current satellite radio systems largely underutilize the available radio link, and that a radio that can adaptively vary the bit rate can more fully exploit it, resulting in increased data throughput and improved power efficiency. We propose one method for implementing the adaptivity, and present simulation results.

  13. 46 CFR 111.05-15 - Neutral grounding.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Neutral grounding. 111.05-15 Section 111.05-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL... propulsion, power, lighting, or distribution system having a neutral bus or conductor must have the...

  14. Epstein on Anchors and Grounds

    Directory of Open Access Journals (Sweden)

    Guala Francesco

    2016-03-01

    Full Text Available The distinction between anchors and grounds is one of the most innovative contributions of The Ant Trap. In this commentary I will argue that the distinction suffers from an ambiguity between tokens and types. This leads Epstein to endorse pluralism about anchors and grounds, a position that is not justified in the book and to which there are plausible alternatives.

  15. Ground water and climate change

    NARCIS (Netherlands)

    Taylor, R.G.; Scanlon, B.; Döll, P.; Rodell, M.; Beek, R. van; Wada, Y.; Longuevergne, L.; Leblanc, M.; Famiglietti, J.S.; Edmunds, M.; Konikow, L.; Green, T.R.; Chen, J.; Taniguchi, M.; Bierkens, M.F.P.; MacDonald, A.; Fan, Y.; Maxwell, R.M.; Yechieli, Y.; Gurdak, J.J.; Allen, D.M.; Shamsudduha, M.; Hiscock, K.; Yeh, Pat J.-F.; Holman, Ian; Treidel, Holger

    2012-01-01

    As the world’s largest distributed store of fresh water, ground water plays a central part in sustaining ecosystems and enabling human adaptation to climate variability and change. The strategic importance of ground water for global water and food security will probably intensify under climate chang

  16. Ground Attenuation of Railroad Noise

    DEFF Research Database (Denmark)

    Makarewicz, R.; Rasmussen, Karsten Bo; Kokowski, P.

    1996-01-01

    The influence of ground effect on railroad noise is described using the concept of the peak A-weighted sound exposure level, and A-weighted sound exposure level. The train is modelled by a continuous line of incoherent point sources that have a cosine directivity. The ground effect is included by...

  17. Ground water and climate change

    NARCIS (Netherlands)

    Taylor, R.G.; Scanlon, B.; Döll, P.; Rodell, M.; Beek, R. van; Wada, Y.; Longuevergne, L.; Leblanc, M.; Famiglietti, J.S.; Edmunds, M.; Konikow, L.; Green, T.R.; Chen, J.; Taniguchi, M.; Bierkens, M.F.P.; MacDonald, A.; Fan, Y.; Maxwell, R.M.; Yechieli, Y.; Gurdak, J.J.; Allen, D.M.; Shamsudduha, M.; Hiscock, K.; Yeh, Pat J.-F.; Holman, Ian; Treidel, Holger

    2012-01-01

    As the world’s largest distributed store of fresh water, ground water plays a central part in sustaining ecosystems and enabling human adaptation to climate variability and change. The strategic importance of ground water for global water and food security will probably intensify under climate

  18. Grounding Damage to Conventional Vessels

    DEFF Research Database (Denmark)

    Lützen, Marie; Simonsen, Bo Cerup

    2003-01-01

    The present paper is concerned with rational design of conventional vessels with regard to bottom damage generated in grounding accidents. The aim of the work described here is to improve the design basis, primarily through analysis of new statistical data for grounding damage. The current...

  19. Grounded action: Achieving optimal and sustainable change

    Directory of Open Access Journals (Sweden)

    Odis E. Simmons, Ph.D.

    2004-11-01

    Full Text Available Grounded action is the application and extension of grounded theory for the purpose of designing and implementing practical actions such as interventions, program designs, action models, social and organizational policies, and change initiatives. Grounded action is grounded theory with an added action component in which actions are systematically derived from a systematically derived explanatory grounded theory. Actions are grounded in the grounded theory in the same way that grounded theories are grounded in data. Grounded actionwas designed by the authors to address complex, multi-dimensionalorganizational and social problems and issues.

  20. Regional analysis of ground and above-ground climate

    Energy Technology Data Exchange (ETDEWEB)

    1981-12-01

    The regional suitability of underground construction as a climate control technique is discussed with reference to (1) a bioclimatic analysis of long-term weather data for 29 locations in the United States to determine appropriate above ground climate control techniques, (2) a data base of synthesized ground temperatures for the coterminous United States, and (3) monthly dew point ground temperature comparisons for identifying the relative likelihood of condensation from one region to another. It is concluded that the suitability of earth tempering as a practice and of specific earth-sheltered design stereotypes varies geographically; while the subsurface almost always provides a thermal advantage on its own terms when compared to above ground climatic data, it can, nonetheless, compromise the effectiveness of other, regionally more important climate control techniques. Also contained in the report are reviews of above and below ground climate mapping schemes related to human comfort and architectural design, and detailed description of a theoretical model of ground temperature, heat flow, and heat storage in the ground. Strategies of passive climate control are presented in a discussion of the building bioclimatic analysis procedure which has been applied in a computer analysis of 30 years of weather data for each of 29 locations in the United States.

  1. Flower power; Flower-Power

    Energy Technology Data Exchange (ETDEWEB)

    Wiedemann, Karsten

    2010-08-15

    Scientists of Kassel university developed a concept for producing heat and electric power from grassland biomass. This strategy of decentral heat and power supply will also contribute to conservation goals. (orig.)

  2. Stockholm Power Tech. Power systems

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-11-01

    The proceedings from this symposium is presented in six volumes: Invited speakers` sessions; Power systems; Power electronics; High-voltage technology; Electrical machines and drives; and Information and control systems. This report covers the power systems volume. Separate abstracts have been prepared for 141 of the 145 papers in this volume

  3. European questions related to satelite power systems

    Science.gov (United States)

    Kassing, D.

    A number of problems which have been identified in recent European studies related to satellite power systems are addressed. Based on energy demand and supply projections for Europe, developed by the International Institute for Applied Systems Analysis, the potential of power satellites in a future energy mix is discussed. A few major constraints are presented which may restrict power transmission to European receiving sites, e.g., orbital limitations, siting problems of the ground station, and economic and institutional issues. Conceptual designs for the structure of ground receiving stations located offshore near the European coastlines are described.

  4. Fault Characteristics and Protection Scheme of the MMC-UPFC under Different Grounding Design

    Science.gov (United States)

    Zheng, Tao; Wang, Ketan; Wu, Dan; Qi, Huanhuan

    2017-07-01

    The Unified Power Flow Controller (UPFC) based on Modular Multilevel Converter (MMC) is more suitable for high-voltage and large-capacity transmission fields. According to the actual needs of demonstration project, 3 grounding proposals were brought out and the effect of different grounding proposals to the fault characteristics and protection schemes is analyzed in detail. The conclusion that only parallel valve side star connected large resistance grounding is more advantageous in MMC-UPFC was derived.

  5. Adaptive Power Control for Space Communications

    Science.gov (United States)

    Thompson, Willie L., II; Israel, David J.

    2008-01-01

    This paper investigates the implementation of power control techniques for crosslinks communications during a rendezvous scenario of the Crew Exploration Vehicle (CEV) and the Lunar Surface Access Module (LSAM). During the rendezvous, NASA requires that the CEV supports two communication links: space-to-ground and crosslink simultaneously. The crosslink will generate excess interference to the space-to-ground link as the distances between the two vehicles decreases, if the output power is fixed and optimized for the worst-case link analysis at the maximum distance range. As a result, power control is required to maintain the optimal power level for the crosslink without interfering with the space-to-ground link. A proof-of-concept will be described and implemented with Goddard Space Flight Center (GSFC) Communications, Standard, and Technology Lab (CSTL).

  6. Ground Control System Description Document

    Energy Technology Data Exchange (ETDEWEB)

    Eric Loros

    2001-07-31

    The Ground Control System contributes to the safe construction and operation of the subsurface facility, including accesses and waste emplacement drifts, by maintaining the configuration and stability of the openings during construction, development, emplacement, and caretaker modes for the duration of preclosure repository life. The Ground Control System consists of ground support structures installed within the subsurface excavated openings, any reinforcement made to the rock surrounding the opening, and inverts if designed as an integral part of the system. The Ground Control System maintains stability for the range of geologic conditions expected at the repository and for all expected loading conditions, including in situ rock, construction, operation, thermal, and seismic loads. The system maintains the size and geometry of operating envelopes for all openings, including alcoves, accesses, and emplacement drifts. The system provides for the installation and operation of sensors and equipment for any required inspection and monitoring. In addition, the Ground Control System provides protection against rockfall for all subsurface personnel, equipment, and the engineered barrier system, including the waste package during the preclosure period. The Ground Control System uses materials that are sufficiently maintainable and that retain the necessary engineering properties for the anticipated conditions of the preclosure service life. These materials are also compatible with postclosure waste isolation performance requirements of the repository. The Ground Control System interfaces with the Subsurface Facility System for operating envelopes, drift orientation, and excavated opening dimensions, Emplacement Drift System for material compatibility, Monitored Geologic Repository Operations Monitoring and Control System for ground control instrument readings, Waste Emplacement/Retrieval System to support waste emplacement operations, and the Subsurface Excavation System

  7. Solar Power Satellites

    CERN Document Server

    Flournoy, Don M

    2012-01-01

    Communication satellites are a $144 billion industry. Is there any space-based industry that could possibly beat that market? 'Solar Power Satellites' shows why and how the space satellite industry will soon begin expanding its market from relaying signals to Earth to generating energy in space and delivering it to the ground as electricity. In all industrialized nations, energy demand is growing exponentially. In the developing world, the need for energy is as basic as food and water. The Sun's energy is available everywhere, and it is non-polluting. As business plans demonstrate its technical feasibility, commercial potential, and environmental acceptability, every country on Earth will look to space for the power it needs.

  8. An Integrated Approach to the Ground Crew Rostering Problem with Work Patterns

    DEFF Research Database (Denmark)

    Lusby, Richard Martin; Hansen, Anders Dohn; Range, Troels Martin;

    This paper addresses the Ground Crew Rostering Problem with Work Patterns, an important manpower planning problem arising in the ground operations of airline companies. We present a cutting stock based integer programming formulation of the problem and describe a powerful decomposition approach...

  9. NB Power Transmission system

    Energy Technology Data Exchange (ETDEWEB)

    Williamson, J. [NB Power Transmission, Fredericton, NB (Canada)

    2006-07-01

    The NB Power Transmission System operates 6700 km of transmission lines having voltages of 69 kV, 138 kV, 230 kV, and 345 kV. The history of lightning protection on this transmission system was presented. Lightning protection with shield wires has been applied selectively on the 69 kV and 138 kV lines and has been applied to all lines in the 230 kV and 345 kV range. Beginning in 2000, line arresters were installed on selected 69 kV and 138 kV lines. It was noted that although overhead shield wires are commonly installed to capture lightning strikes and shield the conductors, problems can occur if the electrical flashover of insulators result in a line to ground fault. Good grounding is needed to ensure that lightning enters the ground from the tower. The new approach is to install line arresters on structures without overhead shield wires. Line arresters are surge arresters applied in parallel with the insulator string. This new line arrester technology was tested by installing nearly 1200 arresters in the Saint John area. This paper described the reasons for choosing line arresters over shield wires and presented the methods of installation. The problems and failure rates of the installed line arresters were presented along with solutions, including solutions to protect lines against lightning in areas with heavy icing. Recommendations for future research into the use, application and development of line arresters were also presented. tabs., figs.

  10. Ground Beef and Food Safety

    Science.gov (United States)

    ... torn. If possible, place the package in a plastic bag so leaking juices won't drip on other ... duty plastic wrap, aluminum foil, freezer paper, or plastic bags made for freezing. Ground beef is safe indefinitely ...

  11. Ground Enterprise Management System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Spacecraft ground systems are on the cusp of achieving "plug-and-play" capability, i.e., they are approaching the state in which the various components can be...

  12. On Grounding of Fast Ships

    DEFF Research Database (Denmark)

    Simonsen, Bo Cerup; Pedersen, Preben Terndrup

    1997-01-01

    numerical examples also indicate that, even with impact speeds of 40 knots against a 1:10 sloping bottom, the global strength of the hull girder is not exceeded by the grounding induced loads.For the local deformation of high-speed ship hulls at the point of contact with the ground, the paper presents...... experimental results from crushing tests of aluminium hull girder components with realistic full-scale scantlings. A comparison with existing simplified calculation procedures for ductile metallic structures show that these procedures cannot be used to predict the crushing behaviour of the fore body of high......The paper deals with analysis of grounding of high-speed crafts. It is the purpose to present a comprehensive mathematical model for calculation of the overall dynamic ship response during grounding. This procedure is applied to derive the motions, the time varying sectional forces and the local...

  13. Ground water and climate change

    Science.gov (United States)

    Taylor, Richard G.; Scanlon, Bridget; Döll, Petra; Rodell, Matt; van Beek, Rens; Wada, Yoshihide; Longuevergne, Laurent; Leblanc, Marc; Famiglietti, James S.; Edmunds, Mike; Konikow, Leonard; Green, Timothy R.; Chen, Jianyao; Taniguchi, Makoto; Bierkens, Marc F.P.; MacDonald, Alan; Fan, Ying; Maxwell, Reed M.; Yechieli, Yossi; Gurdak, Jason J.; Allen, Diana M.; Shamsudduha, Mohammad; Hiscock, Kevin; Yeh, Pat J.-F.; Holman, Ian; Treidel, Holger

    2012-01-01

    As the world's largest distributed store of fresh water, ground water plays a central part in sustaining ecosystems and enabling human adaptation to climate variability and change. The strategic importance of ground water for global water and food security will probably intensify under climate change as more frequent and intense climate extremes (droughts and floods) increase variability in precipitation, soil moisture and surface water. Here we critically review recent research assessing the impacts of climate on ground water through natural and human-induced processes as well as through groundwater-driven feedbacks on the climate system. Furthermore, we examine the possible opportunities and challenges of using and sustaining groundwater resources in climate adaptation strategies, and highlight the lack of groundwater observations, which, at present, limits our understanding of the dynamic relationship between ground water and climate.

  14. Ground water and climate change

    Science.gov (United States)

    Taylor, Richard G.; Scanlon, Bridget; Döll, Petra; Rodell, Matt; van Beek, Rens; Wada, Yoshihide; Longuevergne, Laurent; Leblanc, Marc; Famiglietti, James S.; Edmunds, Mike; Konikow, Leonard; Green, Timothy R.; Chen, Jianyao; Taniguchi, Makoto; Bierkens, Marc F. P.; MacDonald, Alan; Fan, Ying; Maxwell, Reed M.; Yechieli, Yossi; Gurdak, Jason J.; Allen, Diana M.; Shamsudduha, Mohammad; Hiscock, Kevin; Yeh, Pat J.-F.; Holman, Ian; Treidel, Holger

    2013-04-01

    As the world's largest distributed store of fresh water, ground water plays a central part in sustaining ecosystems and enabling human adaptation to climate variability and change. The strategic importance of ground water for global water and food security will probably intensify under climate change as more frequent and intense climate extremes (droughts and floods) increase variability in precipitation, soil moisture and surface water. Here we critically review recent research assessing the impacts of climate on ground water through natural and human-induced processes as well as through groundwater-driven feedbacks on the climate system. Furthermore, we examine the possible opportunities and challenges of using and sustaining groundwater resources in climate adaptation strategies, and highlight the lack of groundwater observations, which, at present, limits our understanding of the dynamic relationship between ground water and climate.

  15. Ground Water and Climate Change

    Science.gov (United States)

    Taylor, Richard G.; Scanlon, Bridget; Doell, Petra; Rodell, Matt; van Beek, Rens; Wada, Yoshihide; Longuevergne, Laurent; Leblanc, Marc; Famiglietti, James S.; Edmunds, Mike; Konikow, Leonard; Green, Timothy R.; Chen, Jianyao; Taniguchi, Makoto; Bierkens, Marc F. P.; MacDonald, Alan; Fan, Ying; Maxwell, Reed M.; Yechieli, Yossi; Gurdak, Jason J.; Allen, Diana M.; Shamsudduha, Mohammad; Hiscock, Kevin; Yeh, Pat J. -F; Holman, Ian; Treidel, Holger

    2013-01-01

    As the world's largest distributed store of fresh water, ground water plays a central part in sustaining ecosystems and enabling human adaptation to climate variability and change. The strategic importance of ground water for global water and food security will probably intensify under climate change as more frequent and intense climate extremes (droughts and floods) increase variability in precipitation, soil moisture and surface water. Here we critically review recent research assessing the impacts of climate on ground water through natural and human-induced processes as well as through groundwater-driven feedbacks on the climate system. Furthermore, we examine the possible opportunities and challenges of using and sustaining groundwater resources in climate adaptation strategies, and highlight the lack of groundwater observations, which, at present, limits our understanding of the dynamic relationship between ground water and climate.

  16. Evaluation of multimodal ground cues

    DEFF Research Database (Denmark)

    Nordahl, Rolf; Lecuyer, Anatole; Serafin, Stefania

    2012-01-01

    This chapter presents an array of results on the perception of ground surfaces via multiple sensory modalities,with special attention to non visual perceptual cues, notably those arising from audition and haptics, as well as interactions between them. It also reviews approaches to combining synth...... synthetic multimodal cues, from vision, haptics, and audition, in order to realize virtual experiences of walking on simulated ground surfaces or other features....

  17. Effects of Transformer DC Bias and the Relationship Between UHVDC Grounding Current and Grounding Resistances%变压器直流偏磁及其与接地电阻关系的研究

    Institute of Scientific and Technical Information of China (English)

    蒋伟; 吴广宁; 肖华

    2008-01-01

    Recently years, UHVDC transmission system is paid more attention to in the field of China's power system. It takes key part in the China electrical power development stratagem. But, many problems are caused by UHVDC system,such as DC bias, corrosion of metal underground and so on. DC bias is harm to the transformers nearby UHVDC grounding polar. In this paper, the influences of DC grounding current on transformer are introduced and some suggestions of DC bias solution were provided. And, the relationship between UHVDC Grounding Current and grounding Resistance of Substation was analyzed. Firstly, two-part network circuit was used to equivalent the grounding circuit. Then, an analysis of rules was done between DC bias current and grounding resistance. Finally, the conclusion is given that DC bias current rises fast as DC grounding resistance or AC grounding resistance rises. It drops when resistance of AC transmission line or interaction resistance between DC grounding system and AC grounding system rises. Decreasing AC grounding resistance and DC grounding resistance is important to restrain DC bias current. Increasing resistance of AC transmission line such as adding resistance into transformer neutral-point grounding is a useful way to limit DC bias current.

  18. Reassessing Power

    Institute of Scientific and Technical Information of China (English)

    CHARLES; K.EBINGER; JOHN; P.BANKS

    2011-01-01

    Fukushima accident increases global concern over nuclear safety The accident at the Fukushima Daiichi Nuclear Power Plant in Japan has had an immediate impact on resurgent interest in nuclear power worldwide.Numerous governments have announced plans to re-examine nuclear energy policy and review the safety of their reactors and the adequacy of their regulatory frameworks.

  19. Power Drain

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Rising coal prices mean dwindling profits for China’s power plants. In some cases,they have forced plants to close their doors If electricity prices were not raised together with fuel prices, the country’spower plants could not survive. This isthe common voice of China’s power plants now.

  20. Power Source

    Science.gov (United States)

    Schooley, Michael L.

    2010-01-01

    Principals are powerful: They are the primary catalysts for creating a lasting foundation for learning, driving school and student performance, and shaping the long-term impact of school improvement efforts. Yet few principals would characterize themselves as powerful. Rather, they're self-effacing, adaptable, pragmatic, and quick to share credit…

  1. Diastatic power

    Science.gov (United States)

    diastatic power: Diastatic power, abbreviated DP, is the total activity of malt starch degrading enzymes that hydrolyze starch to fermentable sugars. The starch degrading enzymes contributing to this process are a-amylase, ß-amylase, limit dextrinase, and a-glucosidase. The driving force for DP a...

  2. SITE ELECTRICAL POWER SYSTEM DESCRIPTION DOCUMENT

    Energy Technology Data Exchange (ETDEWEB)

    E.P. McCann

    1999-04-16

    The Site Electrical Power System receives and distributes utility power to all North Portal site users. The major North Portal users are the Protected Area including the subsurface facility and Balance of Plant areas. The system is remotely monitored and controlled from the Surface Operations Monitoring and Control System. The system monitors power quality and provides the capability to transfer between Off-Site Utility and standby power (including dedicated safeguards and security power). Standby power is only distributed to selected loads for personnel safety and essential operations. Security power is only distributed to essential security operations. The standby safeguards and security power is independent from all other site power. The system also provides surface lighting, grounding grid, and lightning protection for the North Portal. The system distributes power during construction, operation, caretaker, and closure phases of the repository. The system consists of substation equipment (disconnect switches, breakers, transformers and grounding equipment) and power distribution cabling from substation to the north portal switch gear building. Additionally, the system includes subsurface facility substation (located on surface), switch-gear, standby diesel generators, underground duct banks, power cables and conduits, switch-gear building and associated distribution equipment for power distribution. Each area substation distributes power to the electrical loads and includes the site grounding, site lighting and lightning protection equipment. The site electrical power system distributes power of sufficient quantity and quality to meet users demands. The Site Electrical Power System interfaces with the North Portal surface systems requiring electrical power. The system interfaces with the Subsurface Electrical Distribution System which will supply power to the underground facilities from the North Portal. Power required for the South Portal and development side

  3. Grounded theory and feminist inquiry: revitalizing links to the past.

    Science.gov (United States)

    Plummer, Marilyn; Young, Lynne E

    2010-04-01

    Grounded theory has served feminist research endeavors since the mid-1990s. Researchers from a variety of disciplines claim methodological compatibility and incorporate feminist principles into their grounded theory studies. This article seeks to demonstrate the epistemological affinity between feminist inquiry and grounded theory. Although this relationship is not necessarily unique, the authors contend that when combined, it loosens the androcentric moorings of the empirical processes underpinning grounded theory, enabling the researchers to design inquiry with greater potential to reveal issues particular to the lives and experiences of marginalized women. The article begins by retracing the roots of grounded theory and feminist inquiry to identify six key areas where the underpinnings of GT are enriched by a feminist perspective when working with women. In addition, the authors draw on the literature and their experience from a 2005 study of peer support and lone mothers' health to demonstrate the advantages of combining these theoretical perspectives. Finally, the authors recommend that nurse researchers draw on feminist principles to guide their use of grounded theory to better serve the interests of women by surfacing issues of gender and power that influence the health experience.

  4. Power system

    Science.gov (United States)

    Hickam, Christopher Dale

    2008-03-18

    A power system includes a prime mover, a transmission, and a fluid coupler having a selectively engageable lockup clutch. The fluid coupler may be drivingly connected between the prime mover and the transmission. Additionally, the power system may include a motor/generator drivingly connected to at least one of the prime mover and the transmission. The power-system may also include power-system controls configured to execute a control method. The control method may include selecting one of a plurality of modes of operation of the power system. Additionally, the control method may include controlling the operating state of the lockup clutch dependent upon the mode of operation selected. The control method may also include controlling the operating state of the motor/generator dependent upon the mode of operation selected.

  5. mitochondrion Spermophilus musicus (Caucasian mountain ground [

    Lifescience Database Archive (English)

    Full Text Available mitochondrion Spermophilus musicus (Caucasian mountain ground [gbrod]: 2 CDS's (760... of codon usage for each CDS (format) Homepage mitochondrion Spermophilus musicus (Caucasian mountain ground ...

  6. Electric power processing, distribution, management and energy storage

    Science.gov (United States)

    Giudici, R. J.

    1980-01-01

    Power distribution subsystems are required for three elements of the SPS program: (1) orbiting satellite, (2) ground rectenna, and (3) Electric Orbiting Transfer Vehicle (EOTV). Power distribution subsystems receive electrical power from the energy conversion subsystem and provide the power busses rotary power transfer devices, switchgear, power processing, energy storage, and power management required to deliver control, high voltage plasma interactions, electric thruster interactions, and spacecraft charging of the SPS and the EOTV are also included as part of the power distribution subsystem design.

  7. Power Talk

    DEFF Research Database (Denmark)

    Liu, Hongpeng; Yang, Yongheng; Loh, Poh Chiang

    2016-01-01

    In this paper, a novel communication strategy called Power Talk is introduced to realize the power line communication among the Voltage Source Converters (VSC) of DC MicroGrids (MGs). Each VSC transmits information by changing the control parameters, and receives information by observing the local...... output power. By using common coding schemes, which transform the DC MGs in some familiar communication channels, some important communication challenges can be addressed, such as random load variations and VSCs switching, as it do not need a separate communication channel. For this purpose, two multiple...

  8. Response of base isolation system excited by spectrum compatible ground motions

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Han; Kim, Min Kyu; Choi, In Kil [KAERI, Daejeon (Korea, Republic of)

    2012-10-15

    Structures in a nuclear power system are designed to be elastic even under an earthquake excitation. However a structural component such as an isolator shows inelastic behavior inherently. For the seismic assessment of nonlinear structures, the response history analysis should be performed. Especially for the performance based design, where the failure probability of a system needs to be evaluated, the variation of response should be evaluated. In this study, the spectrum compatible ground motions, the artificial ground motion and the modified ground motion, were generated. Using these ground motions, the variations of seismic responses of a simplified isolation system were evaluated.

  9. Acoustic Resonance between Ground and Thermosphere

    Directory of Open Access Journals (Sweden)

    M Matsumura

    2009-04-01

    Full Text Available Ultra-low frequency acoustic waves called "acoustic gravity waves" or "infrasounds" are theoretically expected to resonate between the ground and the thermosphere. This resonance is a very important phenomenon causing the coupling of the solid Earth, neutral atmosphere, and ionospheric plasma. This acoustic resonance, however, has not been confirmed by direct observations. In this study, atmospheric perturbations on the ground and ionospheric disturbances were observed and compared with each other to confirm the existence of resonance. Atmospheric perturbations were observed with a barometer, and ionospheric disturbances were observed using the HF Doppler method. An end point of resonance is in the ionosphere, where conductivity is high and the dynamo effect occurs. Thus, geomagnetic observation is also useful, so the geomagnetic data were compared with other data. Power spectral density was calculated and averaged for each month. Peaks appeared at the theoretically expected resonance frequencies in the pressure and HF Doppler data. The frequencies of the peaks varied with the seasons. This is probably because the vertical temperature profile of the atmosphere varies with the seasons, as does the reflection height of infrasounds. These results indicate that acoustic resonance occurs frequently.

  10. Unmanned ground vehicles for integrated force protection

    Science.gov (United States)

    Carroll, Daniel M.; Mikell, Kenneth; Denewiler, Thomas

    2004-09-01

    The combination of Command and Control (C2) systems with Unmanned Ground Vehicles (UGVs) provides Integrated Force Protection from the Robotic Operation Command Center. Autonomous UGVs are directed as Force Projection units. UGV payloads and fixed sensors provide situational awareness while unattended munitions provide a less-than-lethal response capability. Remote resources serve as automated interfaces to legacy physical devices such as manned response vehicles, barrier gates, fence openings, garage doors, and remote power on/off capability for unmanned systems. The Robotic Operations Command Center executes the Multiple Resource Host Architecture (MRHA) to simultaneously control heterogeneous unmanned systems. The MRHA graphically displays video, map, and status for each resource using wireless digital communications for integrated data, video, and audio. Events are prioritized and the user is prompted with audio alerts and text instructions for alarms and warnings. A control hierarchy of missions and duty rosters support autonomous operations. This paper provides an overview of the key technology enablers for Integrated Force Protection with details on a force-on-force scenario to test and demonstrate concept of operations using Unmanned Ground Vehicles. Special attention is given to development and applications for the Remote Detection Challenge and Response (REDCAR) initiative for Integrated Base Defense.

  11. The Improvement and Data Acquisition Systems on Electrical Systems and Grounding Networks in NSRRC

    CERN Document Server

    Liu, Yung-Hui; Chen June Rong; Lin, Yu-Chih; Tsai, Zong-Da

    2005-01-01

    The purpose of this paper is to declare the improvement on electrical and grounding systems in NSRRC. In electrical power system, an Automated Voltage Regulator (AVR) was established to RF system in 2003. The variation of voltage supply from Taiwan Power Company (TPC) is reduced from 3% to 0.2% through the AVR system. And a Supervisory Control and Data Acquisition (SCADA) system was also setup to monitoring the electrical power conditions in each power station. After the high precision grounding systems were constructed in 2004, the stability of beam line was raised. For comprehending the grounding current and noise control, a grounding monitoring system with 32 channels was built in the storage ring. The grounding currents of 4 kickers, one septum and grounding bus are on-line acquisition. Two Electromagnetic Field (EMF) apparatuses were also installed to collect electrical and magnetic fields in the R1 section. It was observed that the electromagnetic field was correlated to grounding currents in certain lo...

  12. Modeled ground water age distributions

    Science.gov (United States)

    Woolfenden, Linda R.; Ginn, Timothy R.

    2009-01-01

    The age of ground water in any given sample is a distributed quantity representing distributed provenance (in space and time) of the water. Conventional analysis of tracers such as unstable isotopes or anthropogenic chemical species gives discrete or binary measures of the presence of water of a given age. Modeled ground water age distributions provide a continuous measure of contributions from different recharge sources to aquifers. A numerical solution of the ground water age equation of Ginn (1999) was tested both on a hypothetical simplified one-dimensional flow system and under real world conditions. Results from these simulations yield the first continuous distributions of ground water age using this model. Complete age distributions as a function of one and two space dimensions were obtained from both numerical experiments. Simulations in the test problem produced mean ages that were consistent with the expected value at the end of the model domain for all dispersivity values tested, although the mean ages for the two highest dispersivity values deviated slightly from the expected value. Mean ages in the dispersionless case also were consistent with the expected mean ages throughout the physical model domain. Simulations under real world conditions for three dispersivity values resulted in decreasing mean age with increasing dispersivity. This likely is a consequence of an edge effect. However, simulations for all three dispersivity values tested were mass balanced and stable demonstrating that the solution of the ground water age equation can provide estimates of water mass density distributions over age under real world conditions.

  13. Methodological issues in grounded theory.

    Science.gov (United States)

    Cutcliffe, J R

    2000-06-01

    Examination of the qualitative methodological literature shows that there appear to be conflicting opinions and unresolved issues regarding the nature and process of grounded theory. Researchers proposing to utilize this method would therefore be wise to consider these conflicting opinions. This paper therefore identifies and attempts to address four key issues, namely, sampling, creativity and reflexivity, the use of literature, and precision within grounded theory. The following recommendations are made. When utilizing a grounded method researchers need to consider their research question, clarify what level of theory is likely to be induced from their study, and then decide when they intend to access and introduce the second body of literature. They should acknowledge that in the early stages of data collection, some purposeful sampling appears to occur. In their search for conceptually dense theory, grounded theory researchers may wish to free themselves from the constraints that limit their use of creativity and tacit knowledge. Furthermore, the interests of researchers might be served by attention to issues of precision including, avoiding method slurring, ensuring theoretical coding occurs, and using predominantly one method of grounded theory while explaining and describing any deviation away from this chosen method. Such mindfulness and the resulting methodological rigour is likely to increase the overall quality of the inquiry and enhance the credibility of the findings.

  14. Instant Windows PowerShell

    CERN Document Server

    Menon, Vinith

    2013-01-01

    Get to grips with a new technology, understand what it is and what it can do for you, and then get to work with the most important features and tasks. A practical, hands-on tutorial approach that explores the concepts of PowerShell in a friendly manner, taking an adhoc approach to each topic.If you are an administrator who is new to PowerShell or are looking to get a good grounding in these new features, this book is ideal for you. It's assumed that you will have some experience in PowerShell and Windows Server, as well being familiar with the PowerShell command-line.

  15. Power Preservation

    DEFF Research Database (Denmark)

    Galster, Kjeld

    Power Preservation (Abstract) In the 17th century, just as today, coalitions needed ‘lead nations’. This was assumed to be a power with great military and economic potentials, and Denmark endeavoured to act as such a leader in the Thirty Years War from 1626 to 28. The results were not encouraging...... in the military field and they were disastrous as far as fiscal matters were concerned. Sweden took over the leadership of the protestant side and she took over Denmark’s place amongst the great powers of the Baltic Region. From that time onwards, Danish influence and options on the international stage gradually...... declined. Thus, Denmark of the 17th century is not to be counted amongst the great powers, but since Christian V’s accession to the throne in 1670 Denmark-Norway has developed into one of Europe’s most highly militarised states. Apart from a permanently combat ready navy, the country maintains a standing...

  16. Practical switching power supply design

    CERN Document Server

    Brown, Martin C

    1990-01-01

    Take the ""black magic"" out of switching power supplies with Practical Switching Power Supply Design! This is a comprehensive ""hands-on"" guide to the theory behind, and design of, PWM and resonant switching supplies. You'll find information on switching supply operation and selecting an appropriate topology for your application. There's extensive coverage of buck, boost, flyback, push-pull, half bridge, and full bridge regulator circuits. Special attention is given to semiconductors used in switching supplies. RFI/EMI reduction, grounding, testing, and safety standards are also deta

  17. Estimation of beryllium ground state energy by Monte Carlo simulation

    Energy Technology Data Exchange (ETDEWEB)

    Kabir, K. M. Ariful [Department of Physical Sciences, School of Engineering and Computer Science, Independent University, Bangladesh (IUB) Dhaka (Bangladesh); Halder, Amal [Department of Mathematics, University of Dhaka Dhaka (Bangladesh)

    2015-05-15

    Quantum Monte Carlo method represent a powerful and broadly applicable computational tool for finding very accurate solution of the stationary Schrödinger equation for atoms, molecules, solids and a variety of model systems. Using variational Monte Carlo method we have calculated the ground state energy of the Beryllium atom. Our calculation are based on using a modified four parameters trial wave function which leads to good result comparing with the few parameters trial wave functions presented before. Based on random Numbers we can generate a large sample of electron locations to estimate the ground state energy of Beryllium. Our calculation gives good estimation for the ground state energy of the Beryllium atom comparing with the corresponding exact data.

  18. New composite fiber-optic overhead ground wire

    Science.gov (United States)

    Nishiyama, S.; Kitayama, Y.; Ona, A.; Shimada, S.; Kikuta, T.

    1986-11-01

    A composite fiber-optic overhead ground wire (OPGW) has already been used commercially. Most of the electric power companies have the plans to establish new telecommunication networks by means of OPGW, and it is greatly needed to develop OPGW which has a maximum number of fibers for specific ground wire size with low transmission loss, easy handling and higher reliability. We have developed New OPGW, which satisfies these demands. It has the following features: (1) 18 fibers within 75 sq mm ground wire. (2) The fiber is a pure silica core and a fluorine-doped cladding single mode fiber with the average transmission loss of 0.4 dB/km at 1.3 micron. (3) Six fibers are stranded into a compact bunch and three bunches are housed in the spiral grooves of an aluminum spacer.

  19. Introduction to electrical power and power electronics

    CERN Document Server

    Patel, Mukund R

    2012-01-01

    Power Generation, Distribution, and Utilization AC Power Fundamentals Common Aspects of Power Equipments AC Generator AC and DC Motors Transformer Power Cable Power Distribution Fault Current Analysis System ProtectionEconomic Use of PowerElectrochemical BatteryPower Electronics and Motor Drives Power Electronics Devices DC-DC Converters AC-DC-AC Converters Variable-Frequency Drives Quality of Power Power Converter CoolingAppendixIndex

  20. Grounding & human health - a review

    Science.gov (United States)

    Jamieson, I. A.; Jamieson, S. S.; ApSimon, H. M.; Bell, J. N. B.

    2011-06-01

    Whilst grounding is often undertaken in industry as a matter of good practice in situations where the risk of excess charge exists, little thought is usually given to the biological effects that such measures may have, or possible benefits that may arise from the more widespread application of electrostatic and other 'electromagnetic hygiene' measures in hospitals and the general built environment. Research, which is still in its infancy, indicates that grounding the human body using suitable methodologies, particularly in low electromagnetic field environments, can significantly enhance biological functioning. It is proposed that there are often a number of electrostatic and 'electromagnetic hygiene' factors that need to be addressed before the beneficial effects of grounding the human body can be fully realised in many everyday environments.

  1. Effect of spatial coherence on laser beam self-focusing from orbit to the ground in the atmosphere.

    Science.gov (United States)

    Deng, Hanling; Ji, Xiaoling; Li, Xiaoqing; Zhang, Hao; Wang, Xianqu; Zhang, Yuqiu

    2016-06-27

    The effect of spatial coherence on laser beam self-focusing in the atmosphere to assist delivering powerful laser beams from orbit to the ground is studied. It is found that a fully coherent beam is more strongly compressed on the ground than a partially (spatial) coherent beam (PCB), even so, for a PCB the compressed spot size on the ground may be reduced below the diffraction limit due to self-focusing effect, and a PCB has higher threshold critical power than a fully coherent beam. Furthermore, an effective design rule for maximal compression without beam splitting of the transported PCB from orbit to the ground is presented.

  2. Ground-Based High Energy Power Beaming in Support of Spacecraft Power Requirements

    Science.gov (United States)

    2006-06-01

    Near Infrared System ADOPT Adaptive Optics module of Telescopio Nazionale Galileo ALFA Arecibo L-band Feed Array AMOS Air Force Maui Optical... Telescopio Nazionale Galileo T/T Tip/Tilt VLT Very Large Telescope WFS Wave Front Sensor xx THIS PAGE...26 3-D plot of the intensity distribution in a stellar image. 55 b. ADOPT The Adaptive Optics module of Telescopio Nazionale Galileo (AdOpt@TNG

  3. Laser ranging ground station development

    Science.gov (United States)

    Faller, J. E.

    1973-01-01

    The employment of ground to conduct radar range measurements of the lunar distance is discussed. The advantages of additional ground stations for this purpose are analyzed. The goals which are desirable for any new type of ranging station are: (1) full time availability of the station for laser ranging, (2) optimization for signal strength, (3) automation to the greatest extent possible, (4) the capability for blind pointing, (5) reasonable initial and modest operational costs, and (6) transportability to enhance the value of the station for geophysical purposes.

  4. Engineering applications of strong ground motion simulation

    Science.gov (United States)

    Somerville, Paul

    1993-02-01

    design response spectra for crustal earthquakes at a power plant site in California and for subduction earthquakes in the Seattle-Portland region. We also demonstrate the use of simulation methods for modeling the attenuation of strong ground motion, and show evidence of the effect of critical reflections from the lower crust in causing the observed flattening of the attenuation of strong ground motion from the 1988 Saguenay, Quebec, and 1989 Loma Prieta earthquakes.

  5. Aerodynamic ground effect in fruitfly sized insect takeoff

    CERN Document Server

    Kolomenskiy, Dmitry; Engels, Thomas; Liu, Hao; Schneider, Kai; Nave, Jean-Christophe

    2015-01-01

    Flapping-wing takeoff is studied using numerical modelling, considering the voluntary takeoff of a fruitfly as reference. The parameters of the model are then varied to explore the possible effects of interaction between the flapping-wing model and the ground plane. The numerical method is based on a three-dimensional Navier-Stokes solver and a simple flight dynamics solver that accounts for the body weight, inertia, and the leg thrust. Forces, power and displacements are compared for takeoffs with and without ground effect. Natural voluntary takeoff of a fruitfly, modified takeoffs and hovering are analyzed. The results show that the ground effect during the natural voluntary takeoff is negligible. In the modified takeoffs, the ground effect does not produce any significant increase of the vertical force neither. Moreover, the vertical force even drops in most of the cases considered. There is a consistent increase of the horizontal force, and a decrease of the aerodynamic power, if the rate of climb is suff...

  6. Advantages of Unfair Quantum Ground-State Sampling.

    Science.gov (United States)

    Zhang, Brian Hu; Wagenbreth, Gene; Martin-Mayor, Victor; Hen, Itay

    2017-04-21

    The debate around the potential superiority of quantum annealers over their classical counterparts has been ongoing since the inception of the field. Recent technological breakthroughs, which have led to the manufacture of experimental prototypes of quantum annealing optimizers with sizes approaching the practical regime, have reignited this discussion. However, the demonstration of quantum annealing speedups remains to this day an elusive albeit coveted goal. We examine the power of quantum annealers to provide a different type of quantum enhancement of practical relevance, namely, their ability to serve as useful samplers from the ground-state manifolds of combinatorial optimization problems. We study, both numerically by simulating stoquastic and non-stoquastic quantum annealing processes, and experimentally, using a prototypical quantum annealing processor, the ability of quantum annealers to sample the ground-states of spin glasses differently than thermal samplers. We demonstrate that (i) quantum annealers sample the ground-state manifolds of spin glasses very differently than thermal optimizers (ii) the nature of the quantum fluctuations driving the annealing process has a decisive effect on the final distribution, and (iii) the experimental quantum annealer samples ground-state manifolds significantly differently than thermal and ideal quantum annealers. We illustrate how quantum annealers may serve as powerful tools when complementing standard sampling algorithms.

  7. High Power Factor Power Design

    Directory of Open Access Journals (Sweden)

    Zhang Jing-yi

    2013-07-01

    Full Text Available The PFC circuit takes UCC28019 made by TI Company as the core of system control, realize the power factor correction circuit functions, and the circuit power factor can be measured. Through a variety of detection circuit, with the support SCM control. And 30V~36V output voltage regulator can be set; with over-current protection circuits function, and be able to automatically back. Output current, voltage, and little significant value are displayed by display modules.

  8. Field trial of composite fiber-optic overhead ground wire

    Science.gov (United States)

    Kubota, S.; Kawahira, H.; Nakajima, T.; Matsubara, I.; Saito, Y.; Kitayama, Y.

    A composite fiber-optic ground wire (OPGW), which provides additional communication capabilities for system protection and control of overhead power transmission systems has been developed. After laboratory tests, the OPGW was strung along a live power transmission line in a mountainous region and has been confirmed to have sufficient performance to establish a high-speed digital transmission network able to withstand actual conditions. The field line, constructed substantially by existing techniques, has proved that the new OPGW, accessories such as clamps and joint boxes, installation technique, and on-tower splicing method can be effectively utilized to produce a protection and control system with extremely stable characteristics.

  9. Practical aspects of tritium measurement in ground and surface waters

    Energy Technology Data Exchange (ETDEWEB)

    Nitzsche, O. [Technische Univ. Bergakademie Freiberg (Germany). Inst. fuer Angewandte Physik; Hebert, D. [Technische Univ. Bergakademie Freiberg (Germany). Inst. fuer Angewandte Physik

    1997-03-01

    Tritium measurements are a powerful tool in hydrological and hydrogeological investigations for detecting mean residence times of several water reservoirs. Due to the low tritium activities in precipitation, ground and surface waters a low level measurement is necessary. Therefore often the liquid scintillation counting after an electrolytic enrichment of water is used. In this paper some practical aspects and problems of measurement are discussed and the problem of contamination in low level laboratories is shown. (orig.)

  10. Space Theory and Strategy: War From the High Ground Down

    Science.gov (United States)

    2016-06-01

    Strategy is the “art of creating power.”30 Strategy constantly adjusts to current realities generating advantageous options.31 Thus, it makes sense to...SPACE THEORY AND STRATEGY: WAR FROM THE HIGH GROUND DOWN BY ANGELO FERNANDEZ A THESIS PRESENTED TO THE FACULTY OF THE SCHOOL...you find a way to make me laugh. Thank you for the memories and I can not wait to make more. vi ABSTRACT This thesis provides a

  11. Maximum Safety Regenerative Power Tracking for DC Traction Power Systems

    Directory of Open Access Journals (Sweden)

    Guifu Du

    2017-02-01

    Full Text Available Direct current (DC traction power systems are widely used in metro transport systems, with running rails usually being used as return conductors. When traction current flows through the running rails, a potential voltage known as “rail potential” is generated between the rails and ground. Currently, abnormal rises of rail potential exist in many railway lines during the operation of railway systems. Excessively high rail potentials pose a threat to human life and to devices connected to the rails. In this paper, the effect of regenerative power distribution on rail potential is analyzed. Maximum safety regenerative power tracking is proposed for the control of maximum absolute rail potential and energy consumption during the operation of DC traction power systems. The dwell time of multiple trains at each station and the trigger voltage of the regenerative energy absorbing device (READ are optimized based on an improved particle swarm optimization (PSO algorithm to manage the distribution of regenerative power. In this way, the maximum absolute rail potential and energy consumption of DC traction power systems can be reduced. The operation data of Guangzhou Metro Line 2 are used in the simulations, and the results show that the scheme can reduce the maximum absolute rail potential and energy consumption effectively and guarantee the safety in energy saving of DC traction power systems.

  12. Design analysis for grounding experiments

    NARCIS (Netherlands)

    Lemmen, P.P.M.; Vredeveldt, A.W.; Pinkster, J.A.

    1996-01-01

    In 1995 a series of six grounding experiments has been carried out with a 600 Tonne inland water way tanker. At the how of the vessel test sections could be fitted, which were run into an artificial rock. The design of the support structures for the test sections and for the rock required the predic

  13. Measurements of radar ground returns

    NARCIS (Netherlands)

    Loor, G.P. de

    1974-01-01

    The ground based measurement techniques for the determination of the radar back-scatter of vegetation and soils as used in The Netherlands will be described. Two techniques are employed: one covering a large sample area (> 1000 m2) but working at low grazing angels only and one (short range) coverin

  14. Grounding experiments on soft bottoms

    DEFF Research Database (Denmark)

    Sterndorff, M.J.; Pedersen, Preben Terndrup

    1996-01-01

    To verify a theoretical analysis procedure for calculation of the hull girder response of ships running aground, a series of large-scale ship grounding experiments was performed on an artificial island made of engineered fill. The tests were conducted by running a condemned fishing vessel up...

  15. The Envisat-1 ground segment

    Science.gov (United States)

    Harris, Ray; Ashton, Martin

    1995-03-01

    The European Space Agency (ESA) Earth Remote Sensing Satellite (ERS-1 and ERS-2) missions will be followed by the Polar Orbit Earth Mission (POEM) program. The first of the POEM missions will be Envisat-1. ESA has completed the design phase of the ground segment. This paper presents the main elements of that design. The main part of this paper is an overview of the Payload Data Segment (PDS) which is the core of the Envisat-1 ground segment, followed by two further sections which describe in more detail the facilities to be offered by the PDS for archiving and for user servcies. A further section describes some future issues for ground segment development. Logica was the prime contractor of a team of 18 companies which undertook the ESA financed architectural design study of the Envisat-1 ground segment. The outputs of the study included detailed specifications of the components that will acquire, process, archive and disseminate the payload data, together with the functional designs of the flight operations and user data segments.

  16. Broadband Synthetic Ground Motion Records

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The dataset contains broadband synthetic ground motion records for three events: 1) 1994 M6.7 Northridge, CA, 2) 1989 M7.0 Loma Prieta, CA, and 3) 1999 M7.5 Izmit,...

  17. Acoustic Ground-Impedance Meter

    Science.gov (United States)

    Zuckerwar, A. J.

    1983-01-01

    Helmoltz resonator used in compact, portable meter measures acoustic impedance of ground or other surfaces. Earth's surface is subject of increasing acoustical investigations because of its importance in aircraft noise prediction and measurment. Meter offers several advantages. Is compact and portable and set up at any test site, irrespective of landscape features, weather or other environmental condition.

  18. Grounded action: achieving optimal and sustainable change

    OpenAIRE

    Odis E. Simmons, Ph.D.; Toni A. Gregory, Ed. D.

    2005-01-01

    Grounded Action ist eine Anwendung und Erweiterung der Grounded Theory mit dem Ziel, Interventionen, Programme, Handlungsmodelle etc. zu entwerfen und zu implementieren. Der Grounded Action-Ansatz wurde konzipiert, um der Komplexität und Multidimensionalität von organisatorischen und sozialen Problemstellungen angemessen begegnen zu können. Die Grounded Theory als Strategie der datengegründeten Theorieentwicklung wird insoweit ausgeweitet, als es im Rahmen von Grounded Action um das Entwickel...

  19. Power Down

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ Cai Wending and his colleague Xie Changsheng have been living out of a suitcase for the past two months.The pair,managers at a coal-fired power plant in Hunan Province,have been staying in a modest three-star hotel in Jincheng,a small city in Shanxi Province.They are not the only long-term residents of the hotel.Numerous power plant officials have been drawn to Jincheng from across China,all for the same purpose-to buy coal.

  20. Design considerations for solar power satellites

    Science.gov (United States)

    Arndt, G. D.; Leopold, L.

    1978-01-01

    This report summarizes the performance characteristics of a conceptual solar power satellite (SPS) system with emphasis on the microwave power transmission system. The latest tradeoff studies on photovoltaic and thermal systems for converting solar energy into electricity at the satellite are reviewed. The microwave system, consisting of dc-RF amplifiers, a 1-km phased array, and a ground antenna/rectifier scheme is capable of delivering 5 GW of power to the commercial grid. The transmission efficiencies of smaller system sizes (down to 1 GW) are compared with that of the nominal 5 GW system. At present the frequency region of interest is the IMS (industrial, medical, and scientific) band at 2450 plus or minus 50 MHz. Economic and technical tradeoffs as a function of the microwave operating frequency are considered. Candidate dc-RF power converter tubes, including medium-power amplitrons, high-power klystrons, and low-power solid state amplifiers, are examined.

  1. Reliability of electrical power systems for coal mines

    Energy Technology Data Exchange (ETDEWEB)

    Razgil' deev, G.I.; Kovalev, A.P.; Serkyuk, L.I.

    1982-01-01

    This is a method for evaluating the reliability of comprehensive mining power systems. The systems reliability is influenced by the selectivity of maximum protection, ground-short protection, the subdivision of the circuitry, the character of the systems failures, etc.

  2. Stakeholder Power and Organizational Learning in Corporate Environmental Management

    NARCIS (Netherlands)

    F.H. Wijen (Frank); N.J. Roome (Nigel)

    2006-01-01

    textabstractThe literatures on stakeholder engagement by companies and organizational learning give little consideration to the power (or influence) of stakeholders to affect the process or content of organizational learning. These literatures generally assume that common ground between companies

  3. Power quality on campus

    Energy Technology Data Exchange (ETDEWEB)

    Copper Development Association

    2011-05-15

    The Maria Stata Center on the campus of the Massachusetts Institute of Technology (MIT) is home to the Computer Science and Artificial Intelligence Laboratory (CSAIL), the Laboratory for Information and Decision Systems (LIDS) and the Department of Linguistics and Philosophy. Computers and networks are everywhere on campus and the electrical infrastructure, mainly made of copper, ensures the highest level of power quality. The copper-based grounding system helps stabilize the wiring system and several K-rated transformers help accommodate harmonic currents and improve energy efficiency. Separation from sensitive and non-sensitive branch circuits helps to shield sensitive equipment from electrical noise, and the installation of transient voltage surge suppression equipment assures maximum protection from voltage surges. .

  4. Cost estimate guidelines for advanced nuclear power technologies

    Energy Technology Data Exchange (ETDEWEB)

    Hudson, C.R. II

    1987-07-01

    To make comparative assessments of competing technologies, consistent ground rules must be applied when developing cost estimates. This document provides a uniform set of assumptions, ground rules, and requirements that can be used in developing cost estimates for advanced nuclear power technologies.

  5. Cost estimate guidelines for advanced nuclear power technologies

    Energy Technology Data Exchange (ETDEWEB)

    Delene, J.G.; Hudson, C.R. II.

    1990-03-01

    To make comparative assessments of competing technologies, consistent ground rules must be applied when developing cost estimates. This document provides a uniform set of assumptions, ground rules, and requirements that can be used in developing cost estimates for advanced nuclear power technologies. 10 refs., 8 figs., 32 tabs.

  6. Cost estimate guidelines for advanced nuclear power technologies

    Energy Technology Data Exchange (ETDEWEB)

    Hudson, C.R. II

    1986-07-01

    To make comparative assessments of competing technologies, consistent ground rules must be applied when developing cost estimates. This document provides a uniform set of assumptions, ground rules, and requirements that can be used in developing cost estimates for advanced nuclear power technologies.

  7. Portable sensor technology for rotational ground motions

    Science.gov (United States)

    Bernauer, Felix; Wassermann, Joachim; Guattari, Frédéric; Igel, Heiner

    2016-04-01

    In this contribution we present performance characteristics of a single component interferometric fiber-optic gyroscope (IFOG). The prototype sensor is provided by iXBlue, France. It is tested in the framework of the European Research Council Project, ROMY (Rotational motions - a new observable for seismology), on its applicability as a portable and field-deployable sensor for rotational ground motions. To fully explore the benefits of this new seismic observable especially in the fields of vulcanology, ocean generated noise and geophysical exploration, such a sensor has to fulfill certain requirements regarding portability, power consumption, time stamping stability and dynamic range. With GPS-synchronized time stamping and miniseed output format, data acquisition is customized for the use in seismology. Testing time stamping accuracy yields a time shift of less than 0.0001 s and a correlation coefficient of 0.99 in comparison to a commonly used data acquisition system, Reftek 120. Sensor self-noise is below 5.0 ṡ 10-8 rads-1Hz-1/2 for a frequency band from 0.001 Hz to 5.0 Hz. Analysis of Allan deviation shows an angle random walk of 3.5 ṡ 10-8 rads-1Hz-1/2. Additionally, the operating range diagram is shown and ambient noise analysis is performed. The sensitivity of sensor self-noise to variations in surrounding temperature and magnetic field is tested in laboratory experiments. With a power consumption of less than 10 W, the whole system (single component sensor + data acquisition) is appropriate for field use with autonomous power supply.

  8. Research on ground heat exchanger of Ground Source Heat Pump technique

    Institute of Scientific and Technical Information of China (English)

    LIU Dong-sheng; SUN You-hong; GAO Ke; WU Xiao-hang

    2004-01-01

    Ground Source Heat Pump technique and its operating principle are described in this paper. Ground heat exchanger is the key technique of ground source heat pump and its pattems are discussed. Software is helpful to design ground heat exchanger. A project of Chinese Ground Source Heat Pump is introduced and its market is more and more extensive.

  9. Powering up

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    China building the world’s first third-generation nuclear power plants based on American technology Almost 30 years ago, a partial core meltdown occurred in one of the two nuclear reactors at Three Mile llsland Nuclear Generating Station in

  10. Comic Power

    DEFF Research Database (Denmark)

    Tønder, Lars

    2014-01-01

    by skepticism about the enduring contributions of comic acts, and it then goes on to suggest that we turn to an alternative trajectory in democratic theory, one that encourages us to focus on the empowering and pluralizing potential embedded in what I name “comic power.” The wager is that attention...

  11. Power Play

    Institute of Scientific and Technical Information of China (English)

    BRADLEY GARDNER

    2008-01-01

    @@ Bill Emmott's new book,Rivals:How the Power Struggle Between China,India and Japan Will Shape Our Next Decade,is an investigation of the problematic relationship between China,India,and Japan,as two of those countries begin to assert themselves on the world stage,and how the situation could result in all-out conflict.

  12. Power Talk

    DEFF Research Database (Denmark)

    Stefanovic, Cedomir; Popovski, Petar; Angjelichinoski, Marko

    2015-01-01

    , while it is received by processing the bus measurements that units perform. This implies that the communication does not require a dedicated modem, but instead it is piggybacked on top of the power electronics. The communication is challenged by the random fluctuations of the voltage level due...

  13. Power semiconductors

    CERN Document Server

    Kubát, M

    1984-01-01

    The book contains a summary of our knowledge of power semiconductor structures. It presents first a short historic introduction (Chap. I) as well as a brief selection of facts from solid state physics, in particular those related to power semiconductors (Chap. 2). The book deals with diode structures in Chap. 3. In addition to fundamental facts in pn-junction theory, the book covers mainly the important processes of power structures. It describes the emitter efficiency and function of microleaks (shunts). the p +p and n + n junctions, and in particular the recent theory of the pin, pvn and p1tn junctions, whose role appears to be decisive for the forward mode not only of diode structures but also of more complex ones. For power diode structures the reverse mode is the decisive factor in pn-junction breakdown theory. The presentation given here uses engineering features (the multiplication factor M and the experimentally detected laws for the volume and surface of crystals), which condenses the presentation an...

  14. POWER FUNCTIONS

    Institute of Scientific and Technical Information of China (English)

    王雷

    2008-01-01

    <正>A power function of degree n is a function of the form f(x)=ax~n.For large n,it appears that the graph coincide with the x-axis near the origin,but it does not;the graph actually touches the x—axis only at the origin.

  15. Power Shift

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ "We are entering a new era of world history: the end of Western domination and the arrival of the Asian century. The question is: will Washington wake up to this reality?" This is the central premise of Kishore Mahbubani's provocative new book The New Asian Hemisphere: The Irresistible Shift of Global Power to the East.

  16. Power branding

    Energy Technology Data Exchange (ETDEWEB)

    Chambers, A.

    1998-12-31

    For most of its century-long history, electricity was a natural monopoly, due in part to the excessive cost of the necessary infrastructure. In the past decade, however, politics have pushed the industry toward competition and consumer choice. At the same time, technology has been developed that allows consumers to choose their electricity supplier and to track the flow of power through the various grids and lines. In her new book, Power Branding, author and industry expert Ann Chambers examines marketing and branding of electricity -- what it is, how it`s done, what its benefits are for electric utilities, marketers, and even natural gas companies allied with the utilities. She surveys industry leaders who have already taken a dive into the ocean of marketing and offers lessons drawn from their experiences. She also takes a look at other formerly regulated industries -- airlines, telephone, natural gas -- and describes how their rebirth as free-market industries may affect the course of the electric utility industry`s experience. The contents include: Introduction; Basics of branding: Brand image; Value-added services; Southern Company; Duke Energy; UtiliCorp/EnergyOne/Aquila--big and brand; Engage energy; Florida Power and Light Co.; Enron; Convergence; Lessons from the natural gas industry; Lessons from other industries; Conclusion; Resources; Glossary of branding, marketing and Btu convergence; and Major federal legislation affecting the electric power industry.

  17. "Naturalist Inquiry" and Grounded Theory

    Directory of Open Access Journals (Sweden)

    Barney G. Glaser

    2004-01-01

    Full Text Available The world of Qualitative Data Analysis (QDA methodology became quite taken with LINCOLN and GUBA's book "Naturalist Inquiry" (1985. I have no issue with it with respect to its application to QDA; it helped clarify and advance so many QDA issues. However, its application to Grounded Theory (GT has been a major block on GT, as originated, by its cooptation and corruption hence remodeling of GT by default. LINCOLN and GUBA have simply assumed GT is just another QDA method, which it is not. In "The Grounded Theory Perspective II" (GLASER 2002a, Chapter 9 on credibility, I have discussed "Naturalist In­quiry" (NI thought regarding how LINCOLN and GUBA's notion of "trustworthy" data (or worrisome data orientation and how their view of constant comparison can and has remodeled and eroded GT. In this paper I will consider other aspects of NI that remodel GT. URN: urn:nbn:de:0114-fqs040170

  18. Predicting Ground Motion from Induced Earthquakes in Geothermal Areas

    Science.gov (United States)

    Douglas, J.; Edwards, B.; Convertito, V.; Sharma, N.; Tramelli, A.; Kraaijpoel, D.; Cabrera, B. M.; Maercklin, N.; Troise, C.

    2013-06-01

    Induced seismicity from anthropogenic sources can be a significant nuisance to a local population and in extreme cases lead to damage to vulnerable structures. One type of induced seismicity of particular recent concern, which, in some cases, can limit development of a potentially important clean energy source, is that associated with geothermal power production. A key requirement for the accurate assessment of seismic hazard (and risk) is a ground-motion prediction equation (GMPE) that predicts the level of earthquake shaking (in terms of, for example, peak ground acceleration) of an earthquake of a certain magnitude at a particular distance. Few such models currently exist in regard to geothermal-related seismicity, and consequently the evaluation of seismic hazard in the vicinity of geothermal power plants is associated with high uncertainty. Various ground-motion datasets of induced and natural seismicity (from Basel, Geysers, Hengill, Roswinkel, Soultz, and Voerendaal) were compiled and processed, and moment magnitudes for all events were recomputed homogeneously. These data are used to show that ground motions from induced and natural earthquakes cannot be statistically distinguished. Empirical GMPEs are derived from these data; and, although they have similar characteristics to recent GMPEs for natural and mining-related seismicity, the standard deviations are higher. To account for epistemic uncertainties, stochastic models subsequently are developed based on a single corner frequency and with parameters constrained by the available data. Predicted ground motions from these models are fitted with functional forms to obtain easy-to-use GMPEs. These are associated with standard deviations derived from the empirical data to characterize aleatory variability. As an example, we demonstrate the potential use of these models using data from Campi Flegrei.

  19. Radon determination in ground water

    Energy Technology Data Exchange (ETDEWEB)

    Segovia A, N.; Bulbulian G, S

    1991-08-15

    Studies on natural radioactivity in ground water were started in Mexico in San Luis Potosi state followed by samplings from deep wells and springs in the states of Mexico and Michoacan. The samples were analyzed for solubilized and {sup 226} Ra- supported {sup 222} Rn. Some of them were also studied for {sup 234} U/ {sup 238} U activity ratio. In this paper we discuss the activities obtained and their relationship with the geologic characteristics of the studied zones. (Author)

  20. Block ground interaction of rockfalls

    Science.gov (United States)

    Volkwein, Axel; Gerber, Werner; Kummer, Peter

    2016-04-01

    During a rockfall the interaction of the falling block with the ground is one of the most important factors that define the evolution of a rockfall trajectory. It steers the rebound, the rotational movement, possibly brake effects, friction losses and damping effects. Therefore, if most reliable rockfall /trajectory simulation software is sought a good understanding of the block ground interaction is necessary. Today's rockfall codes enable the simulation of a fully 3D modelled block within a full 3D surface . However, the details during the contact, i.e. the contact duration, the penetration depth or the dimension of the marks in the ground are usually not part of the simulation. Recent field tests with rocks between 20 and 80 kg have been conducted on a grassy slope in 2014 [1]. A special rockfall sensor [2] within the blocks measured the rotational velocity and the acting accelerations during the tests. External video records and a so-called LocalPositioningSystem deliver information on the travel velocity. With these data not only the flight phases of the trajectories but also the contacts with the ground can be analysed. During the single jumps of a block the flight time, jump length, the velocity, and the rotation are known. During the single impacts their duration and the acting accelerations are visible. Further, the changes of rotational and translational velocity influence the next jump of the block. The change of the rotational velocity over the whole trajectory nicely visualizes the different phases of a rockfall regarding general acceleration and deceleration in respect to the inclination and the topography of the field. References: [1] Volkwein A, Krummenacher B, Gerber W, Lardon J, Gees F, Brügger L, Ott T (2015) Repeated controlled rockfall trajectory testing. [Abstract] Geophys. Res. Abstr. 17: EGU2015-9779. [2] Volkwein A, Klette J (2014) Semi-Automatic Determination of Rockfall Trajectories. Sensors 14: 18187-18210.

  1. Ground state of 16O

    Science.gov (United States)

    Pieper, Steven C.; Wiringa, R. B.; Pandharipande, V. R.

    1990-01-01

    A variational method is used to study the ground state of 16O. Expectation values are computed with a cluster expansion for the noncentral correlations in the wave function; the central correlations and exchanges are treated to all orders by Monte Carlo integration. The expansion has good convergence. Results are reported for the Argonne v14 two-nucleon and Urbana VII three-nucleon potentials.

  2. Ground based materials science experiments

    Science.gov (United States)

    Meyer, M. B.; Johnston, J. C.; Glasgow, T. K.

    1988-01-01

    The facilities at the Microgravity Materials Science Laboratory (MMSL) at the Lewis Research Center, created to offer immediate and low-cost access to ground-based testing facilities for industrial, academic, and government researchers, are described. The equipment in the MMSL falls into three categories: (1) devices which emulate some aspect of low gravitational forces, (2) specialized capabilities for 1-g development and refinement of microgravity experiments, and (3) functional duplicates of flight hardware. Equipment diagrams are included.

  3. Middle Ground on Gun Control

    Science.gov (United States)

    2016-12-01

    effective and practical solution that the community embraced. E. THE MIDDLE GROUND Because of the current political environment , more outside the...was made to expire once the NICS was up and running.52 James Brady passed away in 2014 due to complications from the brain damage he suffered as a...readily available means. For example, poisoning is the most common method of suicide in China because pesticides and herbicides that can be deadly are

  4. Inverter Ground Fault Overvoltage Testing

    Energy Technology Data Exchange (ETDEWEB)

    Hoke, Andy [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Nelson, Austin [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Chakraborty, Sudipta [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Chebahtah, Justin [SolarCity Corporation, San Mateo, CA (United States); Wang, Trudie [SolarCity Corporation, San Mateo, CA (United States); McCarty, Michael [SolarCity Corporation, San Mateo, CA (United States)

    2015-08-12

    This report describes testing conducted at NREL to determine the duration and magnitude of transient overvoltages created by several commercial PV inverters during ground fault conditions. For this work, a test plan developed by the Forum on Inverter Grid Integration Issues (FIGII) has been implemented in a custom test setup at NREL. Load rejection overvoltage test results were reported previously in a separate technical report.

  5. Ground based materials science experiments

    Science.gov (United States)

    Meyer, M. B.; Johnston, J. C.; Glasgow, T. K.

    1988-01-01

    The facilities at the Microgravity Materials Science Laboratory (MMSL) at the Lewis Research Center, created to offer immediate and low-cost access to ground-based testing facilities for industrial, academic, and government researchers, are described. The equipment in the MMSL falls into three categories: (1) devices which emulate some aspect of low gravitational forces, (2) specialized capabilities for 1-g development and refinement of microgravity experiments, and (3) functional duplicates of flight hardware. Equipment diagrams are included.

  6. Microwave-powered airship system design for high-altitude power relay and other applications

    Energy Technology Data Exchange (ETDEWEB)

    Dickinson, R.M. [California Inst. of Tech., Pasadena, CA (United States). Guggenheim Jet Propulsion Center

    1997-11-01

    A concept for a next generation of stratospheric airship platforms was presented and examined. The design was based on a 1MW DC power output from beamed microwave power from the ground. The ground and airborne major subsystems were described. In the future, airborne near-stationary platforms could provide power beaming relay functions plus telecommunications and observation. The system will allow for near-continuous regional Earth sensing of soil moisture, crop condition, vehicular traffic on the ground or vessels at sea and craft in the air, environmental impacts, local weather, stream flow and floods, ice, migration patterns, land use, aerial photographs for mapping, surveillance, detection and tracking. A summary description of how the system might be applied and the currently available applicable technology was presented. System requirements and constraints were also described. A rough cost estimate of a point-design was provided. 22 refs., 1 fig.

  7. Poultry power

    Energy Technology Data Exchange (ETDEWEB)

    Loram, G.

    2000-02-01

    This article gives details of the world's largest power plant fired by poultry litter and forestry waste fired in Thetford, UK. The processing of the waste, the injection of the waste by air, the plant operation, and the cleaning of the flue gas are described. The low levels of odour and noise, and the environmental benefits of the plant which produces no methane or carbon dioxide emissions are noted. (uk)

  8. Cyber Power

    Science.gov (United States)

    2010-05-01

    attributed to “patriotic hackers” in Russia who were offended by Estonia’s movement of a World War II monument to Soviet soldiers. In 2008, shortly...internet to mobilize Chinese students to demonstrate against Japan when its officials took positions that offended Chinese views of the 1930s...reduction of power differentials among them. Anyone from a teen age hacker to a major modern government can do damage in cyber space, and as the famous New

  9. Suntech Power

    Institute of Scientific and Technical Information of China (English)

    BRAKLEY GARDNER

    2008-01-01

    @@ Why the new US president could provide a boost for China's largest solar firm Back in the glory days of China investing, Suntech Power (尚德太阳能电力), China's largest solar com-pany, benefited from both inves-tor interest during China's stock market boom, and the growing demand for solar technologies worldwide, as governments be-gan implementing a raft of new measures providing assistance to renewable energy companies.

  10. BRICS Power

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    When Goldman Sachs economist Jim O’Neill coined the acronym BRIC to describe collectively Brazil,Russia,India and China,the world mainly regarded it as one of the easy-come,easy-go terms in economics.A decade later,O’Neill’s concept is not forgotten.It is successfully playing an historic role in representing the shift in global economic power away

  11. Brayton Isotope Power System (BIPS) facility specification

    Energy Technology Data Exchange (ETDEWEB)

    1976-05-31

    General requirements for the Brayton Isotope Power System (BIPS)/Ground Demonstration System (GDS) assembly and test facility are defined. The facility will include provisions for a complete test laboratory for GDS checkout, performance, and endurance testing, and a contamination-controlled area for assembly, fabrication, storage, and storage preparation of GDS components. Specifications, schedules, and drawings are included.

  12. AMS Ground Truth Measurements: Calibration and Test Lines

    Energy Technology Data Exchange (ETDEWEB)

    Wasiolek, P. [National Security Technologies, LLC. (NSTec), Mercury, NV (United States)

    2013-11-01

    Airborne gamma spectrometry is one of the primary techniques used to define the extent of ground contamination after a radiological incident. Its usefulness was demonstrated extensively during the response to the Fukushima nuclear power plant (NPP) accident in March-May 2011. To map ground contamination a set of scintillation detectors is mounted on an airborne platform (airplane or helicopter) and flown over contaminated areas. The acquisition system collects spectral information together with the aircraft position and altitude every second. To provide useful information to decision makers, the count rate data expressed in counts per second (cps) needs to be converted to the terrestrial component of the exposure rate 1 m above ground, or surface activity of isotopes of concern. This is done using conversion coefficients derived from calibration flights. During a large scale radiological event, multiple flights may be necessary and may require use of assets from different agencies. However, as the production of a single, consistent map product depicting the ground contamination is the primary goal, it is critical to establish very early into the event a common calibration line. Such a line should be flown periodically in order to normalize data collected from different aerial acquisition systems and potentially flown at different flight altitudes and speeds. In order to verify and validate individual aerial systems, the calibration line needs to be characterized in terms of ground truth measurements. This is especially important if the contamination is due to short-lived radionuclides. The process of establishing such a line, as well as necessary ground truth measurements, is described in this document.

  13. The Rover Environmental Monitoring Station Ground Temperature Sensor: A Pyrometer for Measuring Ground Temperature on Mars

    Directory of Open Access Journals (Sweden)

    Miguel Ramos

    2010-10-01

    Full Text Available We describe the parameters that drive the design and modeling of the Rover Environmental Monitoring Station (REMS Ground Temperature Sensor (GTS, an instrument aboard NASA’s Mars Science Laboratory, and report preliminary test results. REMS GTS is a lightweight, low-power, and low cost pyrometer for measuring the Martian surface kinematic temperature. The sensor’s main feature is its innovative design, based on a simple mechanical structure with no moving parts. It includes an in-flight calibration system that permits sensor recalibration when sensor sensitivity has been degraded by deposition of dust over the optics. This paper provides the first results of a GTS engineering model working in a Martian-like, extreme environment.

  14. Hazard-consistent ground motions generated with a stochastic fault-rupture model

    Energy Technology Data Exchange (ETDEWEB)

    Nishida, Akemi, E-mail: nishida.akemi@jaea.go.jp [Center for Computational Science and e-Systems, Japan Atomic Energy Agency, 178-4-4, Wakashiba, Kashiwa, Chiba 277-0871 (Japan); Igarashi, Sayaka, E-mail: igrsyk00@pub.taisei.co.jp [Technology Center, Taisei Corporation, 344-1 Nase-cho, Totsuka-ku, Yokohama 245-0051 (Japan); Sakamoto, Shigehiro, E-mail: shigehiro.sakamoto@sakura.taisei.co.jp [Technology Center, Taisei Corporation, 344-1 Nase-cho, Totsuka-ku, Yokohama 245-0051 (Japan); Uchiyama, Yasuo, E-mail: yasuo.uchiyama@sakura.taisei.co.jp [Technology Center, Taisei Corporation, 344-1 Nase-cho, Totsuka-ku, Yokohama 245-0051 (Japan); Yamamoto, Yu, E-mail: ymmyu-00@pub.taisei.co.jp [Technology Center, Taisei Corporation, 344-1 Nase-cho, Totsuka-ku, Yokohama 245-0051 (Japan); Muramatsu, Ken, E-mail: kmuramat@tcu.ac.jp [Department of Nuclear Safety Engineering, Tokyo City University, 1-28-1 Tamazutsumi, Setagaya-ku, Tokyo 158-8557 (Japan); Takada, Tsuyoshi, E-mail: takada@load.arch.t.u-tokyo.ac.jp [Department of Architecture, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan)

    2015-12-15

    Conventional seismic probabilistic risk assessments (PRAs) of nuclear power plants consist of probabilistic seismic hazard and fragility curves. Even when earthquake ground-motion time histories are required, they are generated to fit specified response spectra, such as uniform hazard spectra at a specified exceedance probability. These ground motions, however, are not directly linked with seismic-source characteristics. In this context, the authors propose a method based on Monte Carlo simulations to generate a set of input ground-motion time histories to develop an advanced PRA scheme that can explain exceedance probability and the sequence of safety-functional loss in a nuclear power plant. These generated ground motions are consistent with seismic hazard at a reference site, and their seismic-source characteristics can be identified in detail. Ground-motion generation is conducted for a reference site, Oarai in Japan, the location of a hypothetical nuclear power plant. A total of 200 ground motions are generated, ranging from 700 to 1100 cm/s{sup 2} peak acceleration, which corresponds to a 10{sup −4} to 10{sup −5} annual exceedance frequency. In the ground-motion generation, seismic sources are selected according to their hazard contribution at the site, and Monte Carlo simulations with stochastic parameters for the seismic-source characteristics are then conducted until ground motions with the target peak acceleration are obtained. These ground motions are selected so that they are consistent with the hazard. Approximately 110,000 simulations were required to generate 200 ground motions with these peak accelerations. Deviations of peak ground motion acceleration generated for 1000–1100 cm/s{sup 2} range from 1.5 to 3.0, where the deviation is evaluated with peak ground motion accelerations generated from the same seismic source. Deviations of 1.0 to 3.0 for stress drops, one of the stochastic parameters of seismic-source characteristics, are required to

  15. Airport Ground Resource Planning Tool Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This effort undertakes the creation of an Airport Ground Resource Planning (AGRP) tool. Little or no automation is currently available to support airport ground...

  16. Airborne ground penetrating radar: practical field experiments

    CSIR Research Space (South Africa)

    Van Schoor, Michael

    2013-10-01

    Full Text Available The performance of ground penetrating radar (GPR) under conditions where the ground coupling of the antenna is potentially compromised is investigated. Of particular interest is the effect of increasing the distance between the antennae...

  17. The Development of Constructivist Grounded Theory

    Directory of Open Access Journals (Sweden)

    Jane Mills

    2006-03-01

    Full Text Available Constructivist grounded theory is a popular method for research studies primarily in the disciplines of psychology, education, and nursing. In this article, the authors aim to locate the roots of constructivist grounded theory and then trace its development. They examine key grounded theory texts to discern their ontological and epistemological orientation. They find Strauss and Corbin's texts on grounded theory to possess a discernable thread of constructivism in their approach to inquiry. They also discuss Charmaz's landmark work on constructivist grounded theory relative to her positioning of the researcher in relation to the participants, analysis of the data, and rendering of participants' experiences into grounded theory. Grounded theory can be seen as a methodological spiral that begins with Glaser and Strauss' original text and continues today. The variety of epistemological positions that grounded theorists adopt are located at various points on this spiral and are reflective of their underlying ontologies.

  18. Mechanisms of power in participatory rural planning

    DEFF Research Database (Denmark)

    Johansen, Pia Heike; Chandler, Thomas Lund

    2015-01-01

    by the urban privilege to define the rural qualities and creation of local conflicts and that mechanisms of power that cause such unintended outcomes of rural planning projects should be uncovered. Inspired by Foucault's interpretation of power the paper carries out a grounded theory inspired analysis......This paper explores the specific mechanisms of power in participatory rural planning projects. It follows up on suggestions in planning literature about directing focus at the relational level in the assessment of power, rather than on who has power and who doesn't. The paper argues...... of a Danish rural participatory planning project. The paper concludes that rural planning literature and analysis will benefits from paying attention to the three – in rural participatory planning projects – specific mechanisms of power ‘Institutionalising knowledge and competencies’; ‘Structuring...

  19. Mechanisms of power in participatory rural planning

    DEFF Research Database (Denmark)

    Johansen, Pia Heike; Chandler, Thomas Lund

    2015-01-01

    This paper explores the specific mechanisms of power in participatory rural planning projects. It follows up on suggestions in planning literature about directing focus at the relational level in the assessment of power, rather than on who has power and who doesn't. The paper argues...... by the urban privilege to define the rural qualities and creation of local conflicts and that mechanisms of power that cause such unintended outcomes of rural planning projects should be uncovered. Inspired by Foucault's interpretation of power the paper carries out a grounded theory inspired analysis...... of a Danish rural participatory planning project. The paper concludes that rural planning literature and analysis will benefits from paying attention to the three – in rural participatory planning projects – specific mechanisms of power ‘Institutionalising knowledge and competencies’; ‘Structuring...

  20. On Utilizing Grounded Theory in Business Doctoral Research: Guidance on the Research Design, Procedures, and Challenges

    Directory of Open Access Journals (Sweden)

    Mark Boadu

    2015-05-01

    Full Text Available Grounded theory is a powerful and rigorous theory building methodology that has attracted considerable interest in business research; however, it is a challenging endeavour especially for novice researchers and in particular at the doctoral level. Although several researchers have attempted to clarify the cannons of various grounded theory approaches, still there is a shortage in guidance for doctoral students who wish to apply grounded theory for their studies. Using an example from a grounded theory business doctoral thesis, this paper provides a guide on the research design and utilisation of the Straussian grounded theory at doctoral level. In doing so, the paper discusses the rationale, features, and benefits of grounded theory. Using an example from corporate governance research, the paper illustrates how the procedures of data analysis (coding, theoretical memoing, and theoretical sampling are applied to systematically generate a grounded theory. Finally, the paper discusses major challenges to utilising grounded theory and how these can be addressed by doctoral researchers. This paper provides a clear and pragmatic exposition that can be useful to guide doctoral researchers who are interested in utilizing the Straussian approach of grounded theory in their studies.

  1. Classification of artificial (man-made) ground

    OpenAIRE

    Rosenbaum, M.S.; McMillan, A.A.; Powell, J H; Cooper, A.H.; Culshaw, M.G.; Northmore, K.J.

    2003-01-01

    The legacy inherited from anthropogenic processes needs to be addressed in order to provide reliable and up-to-date ground information relevant to development and regeneration in the urban environment. The legacy includes voids as well as anthropogenic deposits (artificial ground). Their characteristics derive from former quarrying and mining activities, industrial processes creating derelict ground, variably consolidated made ground, and contaminated groundwater and soils. All need to be sys...

  2. A reliable ground bounce noise reduction technique for nanoscale CMOS circuits

    Science.gov (United States)

    Sharma, Vijay Kumar; Pattanaik, Manisha

    2015-11-01

    Power gating is the most effective method to reduce the standby leakage power by adding header/footer high-VTH sleep transistors between actual and virtual power/ground rails. When a power gating circuit transitions from sleep mode to active mode, a large instantaneous charge current flows through the sleep transistors. Ground bounce noise (GBN) is the high voltage fluctuation on real ground rail during sleep mode to active mode transitions of power gating circuits. GBN disturbs the logic states of internal nodes of circuits. A novel and reliable power gating structure is proposed in this article to reduce the problem of GBN. The proposed structure contains low-VTH transistors in place of high-VTH footer. The proposed power gating structure not only reduces the GBN but also improves other performance metrics. A large mitigation of leakage power in both modes eliminates the need of high-VTH transistors. A comprehensive and comparative evaluation of proposed technique is presented in this article for a chain of 5-CMOS inverters. The simulation results are compared to other well-known GBN reduction circuit techniques at 22 nm predictive technology model (PTM) bulk CMOS model using HSPICE tool. Robustness against process, voltage and temperature (PVT) variations is estimated through Monte-Carlo simulations.

  3. Grounded for life: creative symbol-grounding for lexical invention

    Science.gov (United States)

    Veale, Tony; Al-Najjar, Khalid

    2016-04-01

    One of the challenges of linguistic creativity is to use words in a way that is novel and striking and even whimsical, to convey meanings that remain stubbornly grounded in the very same world of familiar experiences as serves to anchor the most literal and unimaginative language. The challenge remains unmet by systems that merely shuttle or arrange words to achieve novel arrangements without concern as to how those arrangements are to spur the processes of meaning construction in a listener. In this paper we explore a problem of lexical invention that cannot be solved without a model - explicit or implicit - of the perceptual grounding of language: the invention of apt new names for colours. To solve this problem here we shall call upon the notion of a linguistic readymade, a phrase that is wrenched from its original context of use to be given new meaning and new resonance in new settings. To ensure that our linguistic readymades - which owe a great deal to Marcel Duchamp's notion of found art - are anchored in a consensus model of perception, we introduce the notion of a lexicalised colour stereotype.

  4. Application of parallelized software architecture to an autonomous ground vehicle

    Science.gov (United States)

    Shakya, Rahul; Wright, Adam; Shin, Young Ho; Momin, Orko; Petkovsek, Steven; Wortman, Paul; Gautam, Prasanna; Norton, Adam

    2011-01-01

    This paper presents improvements made to Q, an autonomous ground vehicle designed to participate in the Intelligent Ground Vehicle Competition (IGVC). For the 2010 IGVC, Q was upgraded with a new parallelized software architecture and a new vision processor. Improvements were made to the power system reducing the number of batteries required for operation from six to one. In previous years, a single state machine was used to execute the bulk of processing activities including sensor interfacing, data processing, path planning, navigation algorithms and motor control. This inefficient approach led to poor software performance and made it difficult to maintain or modify. For IGVC 2010, the team implemented a modular parallel architecture using the National Instruments (NI) LabVIEW programming language. The new architecture divides all the necessary tasks - motor control, navigation, sensor data collection, etc. into well-organized components that execute in parallel, providing considerable flexibility and facilitating efficient use of processing power. Computer vision is used to detect white lines on the ground and determine their location relative to the robot. With the new vision processor and some optimization of the image processing algorithm used last year, two frames can be acquired and processed in 70ms. With all these improvements, Q placed 2nd in the autonomous challenge.

  5. Attenuation of ground vibrations due to different technical sources

    Institute of Scientific and Technical Information of China (English)

    L. Auersch; S. Said

    2010-01-01

    The attenuation of technically induced surface waves is studied theoretically and experimentally. In this paper, nineteen measurements of ground vibrations induced by eight different technical sources including road and rail traffic, vibratory and impulsive construction work or pile driving, explosions, hammer impulses and mass drops are described, and it is shown that the technically induced ground vibrations exhibit a power-law attenuation v ~ r where the exponents q are in the range of 0.5 to 2.0 and depend on the source types. Comparisons performed demonstrate that the measured exponents are considerably higher than theoretically expected. Some potential effects on ground vibration attenuation are theoretically analyzed. The most important effect is due to the material or scattering damping. Each frequency component is attenuated exponentially as exp(-kr), but for a broad-band excitation, the sum of the exponential laws also yields a power law but with a high exponent. Additional effects are discussed, for example the dispersion of the Rayleigh wave due to soil layering, which yields an additional exponent of 0.5 in cases of impulsive loading.

  6. 7 CFR 65.160 - Ground chicken.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Ground chicken. 65.160 Section 65.160 Agriculture... OF BEEF, PORK, LAMB, CHICKEN, GOAT MEAT, PERISHABLE AGRICULTURAL COMMODITIES, MACADAMIA NUTS, PECANS, PEANUTS, AND GINSENG General Provisions Definitions § 65.160 Ground chicken. Ground chicken...

  7. 7 CFR 65.155 - Ground beef.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Ground beef. 65.155 Section 65.155 Agriculture... OF BEEF, PORK, LAMB, CHICKEN, GOAT MEAT, PERISHABLE AGRICULTURAL COMMODITIES, MACADAMIA NUTS, PECANS, PEANUTS, AND GINSENG General Provisions Definitions § 65.155 Ground beef. Ground beef has the...

  8. 21 CFR 184.1409 - Ground limestone.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ground limestone. 184.1409 Section 184.1409 Food... Specific Substances Affirmed as GRAS § 184.1409 Ground limestone. (a) Ground limestone consists essentially... classifying of naturally occurring limestone. (b) The ingredient meets the specifications of the...

  9. Grounded theory: methodology and philosophical perspective.

    Science.gov (United States)

    Ghezeljeh, Tahereh Najafi; Emami, Azita

    2009-01-01

    Constructivist grounded theory reshapes the interactive relationship between researcher and participants and provides the reader with a sense of the analytical views through which the researcher examines the data. This paper presents an overview of grounded theory and constructivist grounded theory, exploring the ontological, epistemological and methodological aspects using examples from nursing research.

  10. 30 CFR 75.801 - Grounding resistors.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Grounding resistors. 75.801 Section 75.801 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Underground High-Voltage Distribution § 75.801 Grounding resistors. The grounding resistor, where...

  11. 49 CFR 234.249 - Ground tests.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Ground tests. 234.249 Section 234.249 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION..., Inspection, and Testing Inspections and Tests § 234.249 Ground tests. A test for grounds on each energy...

  12. 24 CFR 3280.809 - Grounding.

    Science.gov (United States)

    2010-04-01

    ... connected to the grounding bus in the distribution panelboard or disconnecting means. (2) In the electrical... DEVELOPMENT MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS Electrical Systems § 3280.809 Grounding. (a) General. Grounding of both electrical and nonelectrical metal parts in a manufactured home shall...

  13. 14 CFR 141.81 - Ground training.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Ground training. 141.81 Section 141.81... OTHER CERTIFICATED AGENCIES PILOT SCHOOLS Operating Rules § 141.81 Ground training. (a) Except as provided in paragraph (b) of this section, each instructor who is assigned to a ground training course...

  14. Green Power Initiative

    Energy Technology Data Exchange (ETDEWEB)

    Butler, Patrick Barry [Univ. of Iowa, Iowa City, IA (United States)

    2013-01-28

    National energy policy supports the gathering of more detailed and authoritative data on the introduction of renewable bio-based fuels into new and existing district energy systems via the application of biomass gasification. The University of Iowa developed a biomass-fueled, university-scale steam generation system based on biomass gasification technologies. The system serves as a state-of-the-art research and educational facility in the emerging application of gasification in steam generation. The facility, which includes a smaller down-draft gasifier and a larger multi-stage biomass boiler, was designed to operate primarily on wood-based fuels, but has provisions for testing other biomass fuel sources produced within a 100-mile radius, providing enough flexibility to meet the fluctuating local supply of biomass from industry and Midwest agriculture. The equipment was installed in an existing, staffed facility. The down-draft gasifier unit is operated by College of Engineering staff and students, under the direct technical supervision of qualified Utilities plant staff. The Green Power Initiative also includes a substantial, innovative educational component. In addition to an onsite, graduate-level research program in biomass fuels, the investigators have integrated undergraduate and graduate level teaching – through classroom studies and experiential learning – and applied research into a biomass-based, university-scale, functioning power plant. University of Iowa is unique in that it currently has multiple renewable energy technologies deployed, including significant biomass combustion (oat hulls) at its Main Power Plant and a new reciprocating engine based renewable district energy system. This project complements and supports the national energy policy and State of Iowa initiatives in ethanol and biodiesel. Byproducts of ethanol and biodiesel processes (distiller grains) as well as industry residues (oat hulls, wood chips, construction and demolition

  15. The protection of photovoltaic power systems from lightning

    Science.gov (United States)

    Rogers, C. B.

    Lightning protection techniques at nine prototype photovoltaic power system sites with outputs from 18-225 kW are described. Noting that protection schemes are devised to fit isokeraunic data for specific sites, grounding is cited as a common feature for all systems. The grounds are, in separate instances, connected to junction boxes, frames of the solar cell panels, lead from the dc center, from the dc negative terminal, from the frames and equipment, at the array turntable, or from the building rebar frames. The dc power cables are protected by either metal conduit, metal conduit ground wire, direct burial, by rigid metal conduit, ground conductors, or by ground conductors at the ends of the conduit run. Costs run from 0.01-0.28$/W, with all the systems outfitted with bypass and blocking diodes. Direct stroke protection is viewed as less important than isokeraunic data.

  16. Polarimetry from the Ground Up

    CERN Document Server

    Keller, C U

    2008-01-01

    Ground-based solar polarimetry has made great progress over the last decade. Nevertheless, polarimetry is still an afterthought in most telescope and instrument designs, and most polarimeters are designed based on experience and rules of thumb rather than using more formal systems engineering approaches as is common in standard optical design efforts. Here we present the first steps in creating a set of systems engineering approaches to the design of polarimeters that makes sure that the final telescope-instrument-polarimeter system is more than the sum of its parts.

  17. "Naturalist Inquiry" and Grounded Theory

    OpenAIRE

    Barney G. Glaser

    2004-01-01

    Das Buch "Naturalist Inquiry" (NI) von LINCOLN und GUBA (1985) spielt eine wichtige Rolle für die Qualitative Datenanalyse (QDA). Dies ist für das Feld der QDA unproblematisch: NI hat hier wesentlich zur Verdeutlichung und weiteren Entfaltung methodologischer Fragen beigetragen. Bezogen auf die originäre Grounded Theory (GT) hat sich NI jedoch als Hindernis erwiesen durch sukzessive Mitnutzung und "Verfälschung" der ersteren: Für LINCOLN und GUBA ist GT ganz offensichtlich ein QDA-Verfahren (...

  18. "Naturalist Inquiry" und Grounded Theory

    OpenAIRE

    Barney G. Glaser

    2004-01-01

    Das Buch "Naturalist Inquiry" (NI) von LINCOLN und GUBA (1985) spielt eine wichtige Rolle für die Qualitative Datenanalyse (QDA). Dies ist für das Feld der QDA unproblematisch: NI hat hier wesentlich zur Verdeutlichung und weiteren Entfaltung methodologischer Fragen beigetragen. Bezogen auf die originäre Grounded Theory (GT) hat sich NI jedoch als Hindernis erwiesen durch sukzessive Mitnutzung und "Verfälschung" der ersteren: Für LINCOLN und GUBA ist GT ganz offensichtlich ein QDA-Verfahren (...

  19. Ground level cosmic ray observations

    Energy Technology Data Exchange (ETDEWEB)

    Stephens, S.A. [Tata Institute of Fundamental Research, Bombay (International Commission on Radiation Units and Measurements); Grimani, C.; Brunetti, M.T.; Codino, A. [Perugia Univ. (Italy)]|[INFN, Perugia (Italy); Papini, P.; Massimo Brancaccio, F.; Piccardi, S. [Florence Univ. (Italy)]|[INFN, Florence (Italy); Basini, G.; Bongiorno, F. [INFN, Laboratori Nazionali di Frascati, Rome (Italy); Golden, R.L. [New Mexico State Univ., Las Cruces, NM (United States). Particle Astrophysics Lab.; Hof, M. [Siegen Univ. (Germany). Fachbereich Physik

    1995-09-01

    Cosmic rays at ground level have been collected using the NMSU/Wizard - MASS2 instrument. The 17-hr observation run was made on September 9. 1991 in Fort Sumner, New Mexico, Usa. Fort Sumner is located at 1270 meters a.s.l., corresponding to an atmospheric depth of about 887 g/cm{sup 2}. The geomagnetic cutoff is 4.5 GV/c. The charge ratio of positive and negative muons and the proton to muon ratio have been determined. These observations will also be compared with data collected at a higher latitude using the same basic apparatus.

  20. Stop. Write! Writing Grounded Theory

    Directory of Open Access Journals (Sweden)

    Barney G. Glaser, PhD, Hon. PhD

    2012-06-01

    Full Text Available The message in this book, the dictum in this book, is to stop and write when the Grounded Theory (GT methodology puts you in that ready position. Stop unending conceptualization, unending data coverage, and unending listening to others who would egg you on with additional data, ideas and/or requirements or simply wait too long. I will discuss these ideas in detail. My experience with PhD candidates is that for the few who write when ready, many do not and SHOULD. Simply put, many write-up, but many more should.

  1. Leaders break ground for INFINITY

    Science.gov (United States)

    2008-01-01

    Community leaders from Mississippi and Louisiana break ground for the new INFINITY at NASA Stennis Space Center facility during a Nov. 20 ceremony. Groundbreaking participants included (l to r): Gottfried Construction representative John Smith, Mississippi Highway Commissioner Wayne Brown, INFINITY board member and Apollo 13 astronaut Fred Haise, Stennis Director Gene Goldman, Studio South representative David Hardy, Leo Seal Jr. family representative Virginia Wagner, Hancock Bank President George Schloegel, Mississippi Rep. J.P. Compretta, Mississippi Band of Choctaw Indians representative Charlie Benn and Louisiana Sen. A.G. Crowe.

  2. Nonlinear seismic behavior of a CANDU containment building subjected to near-field ground motions

    Energy Technology Data Exchange (ETDEWEB)

    Choi, In Kil; Ahn, Seong Moon; Choun, Young Sun; Seo, Jeong Moon [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    2004-07-01

    The standard response spectrum proposed by US NRC has been used as a design earthquake for the design of Korean nuclear power plant structures. A survey on some of the Quaternary fault segments near Korean nuclear power plants is ongoing. It is likely that these faults will be identified as active ones. If the faults are confirmed as active ones, it will be necessary to reevaluate the seismic safety of the nuclear power plants located near the fault. Near-fault ground motions are the ground motions that occur near an earthquake fault. In general, the near-fault ground motion records exhibit a distinctive long period pulse like time history with very high peak velocities. These features are induced by the slip of the earthquake fault. Near-fault ground motions, which have caused much of the damage in recent major earthquakes, can be characterized by a pulse-like motion that exposes the structure to a high input energy at the beginning of the motion. In this study, nonlinear dynamic time-history analyses were performed to investigate the seismic behavior of a CANDU containment structure subjected to various earthquake ground motions including the near-field ground motions.

  3. Power generation from poultry litter biomass

    Energy Technology Data Exchange (ETDEWEB)

    Giaier, T.A.; Morrow, R.S. [Detroit Stoker Co., Detroit (United States)

    1999-07-01

    The following paper presents the experiences of power plants utilizing poultry litter as a boiler fuel. The combustion of poultry litter provides an innovative solution to problems such as ground water run-off contamination while producing electric power with this renewable fuel. The ash from the combustion process can be utilized for resale as a fertilizer, thereby helping to provide a closed-loop environmental cycle. As with all biomass fuels, the power generated results in a net reduction in CO{sub 2} emissions and thus contributes to the solution of current greenhouse gas problems. (author)

  4. Thermal analysis of underground power cable system

    Science.gov (United States)

    Rerak, Monika; Ocłoń, Paweł

    2017-10-01

    The paper presents the application of Finite Element Method in thermal analysis of underground power cable system. The computations were performed for power cables buried in-line in the ground at a depth of 2 meters. The developed mathematical model allows determining the two-dimensional temperature distribution in the soil, thermal backfill and power cables. The simulations studied the effect of soil and cable backfill thermal conductivity on the maximum temperature of the cable conductor. Also, the effect of cable diameter on the temperature of cable core was studied. Numerical analyses were performed based on a program written in MATLAB.

  5. Power gating of VLSI circuits using MEMS switches in low power applications

    KAUST Repository

    Shobak, Hosam

    2011-12-01

    Power dissipation poses a great challenge for VLSI designers. With the intense down-scaling of technology, the total power consumption of the chip is made up primarily of leakage power dissipation. This paper proposes combining a custom-designed MEMS switch to power gate VLSI circuits, such that leakage power is efficiently reduced while accounting for performance and reliability. The designed MEMS switch is characterized by an 0.1876 ? ON resistance and requires 4.5 V to switch. As a result of implementing this novel power gating technique, a standby leakage power reduction of 99% and energy savings of 33.3% are achieved. Finally the possible effects of surge currents and ground bounce noise are studied. These findings allow longer operation times for battery-operated systems characterized by long standby periods. © 2011 IEEE.

  6. Grounded Eyes on Distant Watery Skies

    Science.gov (United States)

    Kohler, Susanna

    2017-08-01

    What can we learn about exoplanets from high-resolution, ground-based observations? A new view of the nearby upsilon Andromedae system has revealed a great deal about the systems closest-in exoplanet including the presence of water vapor in its atmosphere.Search for WobblesIllustration of how spectral lines shift when observing two objects that orbit each other. Click here to see a simulation of this process. [R. Pogge, OSU]The upsilon Andromedae system is located roughly 44 light-years from Earth. In 1997, a hot Jupiter exoplanet was discovered orbiting the primary star, and more planets were found not long after making this the first multiple-planet system discovered around a main-sequence star.These planets, however, were not discovered due to transits; their orbital planes are not aligned with our line of sight to the star. Instead, the hiddenplanets were first detected via the stars spectrum. The radial velocity method of detecting exoplanets searches for telltale periodic shifts of a stars spectral lines, which are induced by the orbiting planets gravitational tugs.In recent years, ground-based spectroscopy has become ever more powerful; thus revisiting old systems with higher resolution instruments can often open a whole new world of data to us. In the case of a recent study, a team of astronomers led by Danielle Piskorz (California Institute of Technology) revisited upsilon Andromedae with the high-resolution Near Infrared Spectrometer (NIRSPEC) at the Keck telescope in Hawaii. Their goal: to gather data about upsilon Andromedae b, the closest-in planet in the system.Top-down schematic of the orbit of upsilon Andromedae b around its star and the location in the orbit of the authors observations. [Piskorz et al. 2017]An Unusual ArchitecturePiskorz and collaborators obtained 13 different sets of observations of upsilon Andromedae with NIRSPEC across three different wavelength bands. By treating the starplanet system as though it were a spectroscopic binary

  7. Passive heating of the ground surface

    Science.gov (United States)

    Tyburczyk, Anna

    2016-03-01

    The phenomenon of phase change is one of the most important contemporary issues of thermal engineering. In particular, this applies to all kinds of heat exchanger systems, which should achieve the highest possible efficiency while reducing investment and operating costs. Some of these systems are heat pipes or thermosyphons, which, among others, are used for the heat transfer, temperature stabilization and the regulation of heat flux density. Additionally, they are passive systems, and therefore do not require an external power supply. Heat pipes can be used to stabilize the surface temperature of roads and driveways. Large heat tubes can be applied for heating the surface of bridges and overpasses, which become icy in unfavorable climatic conditions. The paper presents research on the test facility, whose main component is a long vertical copper fin. The temperature at the base of the fin was kept constant for a given series of measurements. Heat receiving fluid was ethanol at atmospheric pressure. The measurement methodology and the results of investigations were discussed. The surface temperature distribution was measured with the infrared camera, and on this basis the local values of heat flow and the heat transfer coefficient were determined. The results were presented as boiling curves for both the fin with the smooth surface and the one covered with a metal capillary-porous structure. The results obtained are useful in the design of heat exchangers, including passive heating of the ground.

  8. Passive heating of the ground surface

    Directory of Open Access Journals (Sweden)

    Tyburczyk Anna

    2016-01-01

    Full Text Available The phenomenon of phase change is one of the most important contemporary issues of thermal engineering. In particular, this applies to all kinds of heat exchanger systems, which should achieve the highest possible efficiency while reducing investment and operating costs. Some of these systems are heat pipes or thermosyphons, which, among others, are used for the heat transfer, temperature stabilization and the regulation of heat flux density. Additionally, they are passive systems, and therefore do not require an external power supply. Heat pipes can be used to stabilize the surface temperature of roads and driveways. Large heat tubes can be applied for heating the surface of bridges and overpasses, which become icy in unfavorable climatic conditions. The paper presents research on the test facility, whose main component is a long vertical copper fin. The temperature at the base of the fin was kept constant for a given series of measurements. Heat receiving fluid was ethanol at atmospheric pressure. The measurement methodology and the results of investigations were discussed. The surface temperature distribution was measured with the infrared camera, and on this basis the local values of heat flow and the heat transfer coefficient were determined. The results were presented as boiling curves for both the fin with the smooth surface and the one covered with a metal capillary-porous structure. The results obtained are useful in the design of heat exchangers, including passive heating of the ground.

  9. Common Ground Between Three Cultures

    Directory of Open Access Journals (Sweden)

    Yehuda Peled

    2009-12-01

    Full Text Available The Triwizard program with Israel brought together students from three different communities: an Israeli Arab school, an Israeli Jewish school, and an American public school with few Jews and even fewer Muslims. The two Israeli groups met in Israel to find common ground and overcome their differences through dialogue and understanding. They communicated with the American school via technology such as video-conferencing, Skype, and emails. The program culminated with a visit to the U.S. The goal of the program was to embark upon a process that would bring about intercultural awareness and acceptance at the subjective level, guiding all involved to develop empathy and an insider's view of the other's culture. It was an attempt to have a group of Israeli high school students and a group of Arab Israeli students who had a fearful, distrustful perception of each other find common ground and become friends. TriWizard was designed to have participants begin a dialogue about issues, beliefs, and emotions based on the premise that cross-cultural training strategies that are effective in changing knowledge are those that engage the emotions, and actively develop empathy and an insider's views of another culture focused on what they have in common. Participants learned that they could become friends despite their cultural differences.

  10. The grounding of temporal metaphors

    Science.gov (United States)

    Lai, Vicky T.; Desai, Rutvik H.

    2016-01-01

    Grounded cognition suggests that the processing of conceptual knowledge cued by language relies on the sensory-motor regions. Does temporal language similarly engage brain areas involved in time perception? Participants read sentences that describe the temporal extent of events with motion verbs (Her seminar stretches across the afternoon) and their static controls. Comparison conditions were fictive motion (Her backyard stretches across the desert) and literal motion (Her arm stretches across the table), along with their static controls. Several time sensitive locations, identified using a meta-analysis, showed activation specific to temporal metaphors, including in the left insula, right claustrum, and bilateral posterior superior temporal sulci. Fictive and literal motion contrasts did not show this difference. Fictive motion contrast showed activation in a conceptual motion sensitive area of the left posterior inferior temporal sulcus. These data suggest that language of time is at least partially grounded in experiential time. In addition, motion semantics has different consequences for events and objects: temporal events become animate, while static entities become motional. PMID:26854961

  11. A Digital Ground Distance Relaying Algorithm to Reduce the Effect of Fault Resistance during Single Phase to Ground and Simultaneous Faults

    Directory of Open Access Journals (Sweden)

    Mohammad Razaz

    2015-03-01

    Full Text Available This paper provides an algorithm of fault resistance compensation for digital ground distance relay considering the voltage and current transformer effects. Performance of the conventional ground distance relaying manner is adversely affected by different ground faults and also typical type, called a simultaneous open conductor and ground fault. The proposed scheme by using local-end data only, has shown satisfactory performances under wide variations in fault location, with different values of fault resistance and having positive and negative of power transfer angle. The presented method which has been carried out on the IEEE 14 bus benchmark is executed in PSCAD/EMTDC and MATLAB software, and the results show the accurate performance of mentioned configuration.

  12. Grounding Effect on Common Mode Interference of Underground Inverter

    Directory of Open Access Journals (Sweden)

    CHENG Qiang

    2013-09-01

    Full Text Available For the neutral point not grounded characteristics of underground power supply system in coal mine, this paper studied common mode equivalent circuit of underground PWM inverter, and extracted parasitic parameters of interference propagation path. The author established a common mode and differential mode model of underground inverter. Taking into account the rise time of PWM, the simulation results of conducted interference by Matlab software is compared with measurement spectrum on the AC side and motor side of converter, the difference is consistent showing that the proposed method has some validity. After Comparison of calculation results by Matlab simulation ,it can be concluded that ungrounded neutral of transformer could redue common mode current in PWM system, but not very effective, the most efficient way is to increase grounding  impedance of  inverter and motor.

  13. Power optics

    Energy Technology Data Exchange (ETDEWEB)

    Apollonov, V V [A M Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

    2014-02-28

    By using the theory we developed in the early 1970s, a broad range of phenomena is considered for an optical surface of a solid body that is exposed to radiation arbitrarily varying in time and producing temperature fields, thermoelastic stresses and thermal deformations on the surface layer. The examination is based on the relations (which are similar to Duhamel's integral formula from the theory of heat conduction) between the quantities characterising the thermal stress state in any nonstationary regimes of energy input into a solid. A peculiar feature of the analysis of the thermal stress state in this case consists in the fact that this relation comprises time as a parameter, which in turn is a consequence of incoherence of the quasi-stationary problem of thermoelasticity. This phenomenon is particularly important for the optics of high-power, high-pulse repetition rate lasers, which are being actively developed. In the review, we have recently published in Laser Physics, the thermal stress state of a solid is analysed. In this state, time is treated as an independent variable used in differentiation. Such an approach greatly reduces the applicability of the method. The review published contains data on the use of capillary porous structures made of various materials with different degrees of the surface development. Moreover, such structures can be efficiently employed to increase the heat exchange at a temperature below the boiling point of the coolant. In the present review we discuss the dependences of the limiting laser intensities on the duration of a pulse or a pulse train, corresponding to the three stages of the state of the reflecting surface and leading to unacceptable elastic deformations of the surface, to the plastic yield of the material accompanied by the formation of residual stresses and to the melting of the surface layer. We also analyse the problem of heat exchange in the surface layer with a liquid metal coolant pumped through it

  14. Power optics

    Science.gov (United States)

    Apollonov, V. V.

    2014-02-01

    By using the theory we developed in the early 1970s, a broad range of phenomena is considered for an optical surface of a solid body that is exposed to radiation arbitrarily varying in time and producing temperature fields, thermoelastic stresses and thermal deformations on the surface layer. The examination is based on the relations (which are similar to Duhamel's integral formula from the theory of heat conduction) between the quantities characterising the thermal stress state in any nonstationary regimes of energy input into a solid. A peculiar feature of the analysis of the thermal stress state in this case consists in the fact that this relation comprises time as a parameter, which in turn is a consequence of incoherence of the quasi-stationary problem of thermoelasticity. This phenomenon is particularly important for the optics of high-power, high-pulse repetition rate lasers, which are being actively developed. In the review, we have recently published in Laser Physics, the thermal stress state of a solid is analysed. In this state, time is treated as an independent variable used in differentiation. Such an approach greatly reduces the applicability of the method. The review published contains data on the use of capillary porous structures made of various materials with different degrees of the surface development. Moreover, such structures can be efficiently employed to increase the heat exchange at a temperature below the boiling point of the coolant. In the present review we discuss the dependences of the limiting laser intensities on the duration of a pulse or a pulse train, corresponding to the three stages of the state of the reflecting surface and leading to unacceptable elastic deformations of the surface, to the plastic yield of the material accompanied by the formation of residual stresses and to the melting of the surface layer. We also analyse the problem of heat exchange in the surface layer with a liquid metal coolant pumped through it. The

  15. Modeling and synthesis of strong ground motion

    Indian Academy of Sciences (India)

    S T G Raghu Kanth

    2008-11-01

    Success of earthquake resistant design practices critically depends on how accurately the future ground motion can be determined at a desired site. But very limited recorded data are available about ground motion in India for engineers to rely upon. To identify the needs of engineers, under such circumstances, in estimating ground motion time histories, this article presents a detailed review of literature on modeling and synthesis of strong ground motion data. In particular, modeling of seismic sources and earth medium, analytical and empirical Green’s functions approaches for ground motion simulation, stochastic models for strong motion and ground motion relations are covered. These models can be used to generate realistic near-field and far-field ground motion in regions lacking strong motion data. Numerical examples are shown for illustration by taking Kutch earthquake-2001 as a case study.

  16. Update on the Solar Power Satellite transmitter design

    Energy Technology Data Exchange (ETDEWEB)

    Brown, W.C.

    1986-01-01

    A number of remaining problems in the conceptual design of the transmitting antenna for the Solar Power Satellite have been solved as a result of additional technology development. Much of the technology was derived from the conceptual design of a ground-based transmitting antenna for beaming power to a high altitude airship or airplane.

  17. Dynamic modeling of fluid power transmissions for wind turbines

    NARCIS (Netherlands)

    Diepeveen, N.F.B.; Jarquin Laguna, A.

    2011-01-01

    Fluid power transmission for wind turbines is quietly gaining more ground/interest. The principle of the various concepts presented so far is to convert aerodynamic torque of the rotor blades into a pressurized fluid flow by means of a positive displacement pump. At the other end of the fluid power

  18. Dynamic modeling of fluid power transmissions for wind turbines

    NARCIS (Netherlands)

    Diepeveen, N.F.B.; Jarquin Laguna, A.

    2011-01-01

    Fluid power transmission for wind turbines is quietly gaining more ground/interest. The principle of the various concepts presented so far is to convert aerodynamic torque of the rotor blades into a pressurized fluid flow by means of a positive displacement pump. At the other end of the fluid power

  19. Simulating solar power plant variability :

    Energy Technology Data Exchange (ETDEWEB)

    Lave, Matthew Samuel; Ellis, Abraham; Stein, Joshua.

    2013-06-01

    It is important to be able to accurately simulate the variability of solar PV power plants for grid integration studies. We aim to inform integration studies of the ease of implementation and application-specific accuracy of current PV power plant output simulation methods. This report reviews methods for producing simulated high-resolution (sub-hour or even sub-minute) PV power plant output profiles for variability studies and describes their implementation. Two steps are involved in the simulations: estimation of average irradiance over the footprint of a PV plant and conversion of average irradiance to plant power output. Six models are described for simulating plant-average irradiance based on inputs of ground-measured irradiance, satellite-derived irradiance, or proxy plant measurements. The steps for converting plant-average irradiance to plant power output are detailed to understand the contributions to plant variability. A forthcoming report will quantify the accuracy of each method using application-specific validation metrics.

  20. Wireless power transfer via radiowaves

    CERN Document Server

    Shinohara , Naoki

    2014-01-01

    Recent advances in Wireless Power Transmission (WPT) technologies have enabled various engineering applications with potential product implementation. WPT can be utilized to charge batteries in various pieces of equipment without the need for a wired connection. Energy can be harvested from ambient RF and microwave radiation and 1 million kW microwaves can be transmitted from space to the ground.This book covers all the theory and technologies of WPT, such as microwave generators with semi-conductors and microwave tubes, antennas, phased arrays, beam efficiency, and rectifiers (rectenna). The

  1. Statistical Studies of Ground-Based Optical Lightning Signatures

    Science.gov (United States)

    Hunt, C. R.; Nemzek, R. J.; Suszcynsky, D. M.

    2005-12-01

    Most extensive optical studies of lightning have been conducted from orbit, and the statistics of events collected from earth are relatively poorly documented. The time signatures of optical power measured in the presence of clouds are inevitably affected by scattering,which can distort the signatures by extending and delaying the amplitude profile in time. We have deployed two all-sky photodiode detectors, one in New Mexico and one in Oklahoma, which are gathering data alongside electric field change monitors as part of the LANL EDOTX Great Plains Array. Preliminary results show that the photodiode is sensitive to approximately 50% or more of RF events detected at ranges of up to 30 km, and still has some sensitivity at ranges in excess of 60 km (distances determined by the EDOTX field-change array). The shapes of events within this range were assessed, with focus on rise time, width, peak power, and their correlation to corresponding electric field signatures, and these are being compared with published on-orbit and ground-based data. Initial findings suggest a mean characteristic width (ratio of total detected optical energy to peak power) of 291 +/- 12 microseconds and a mean delay between the RF signal peak and optical peak of 121 +/- 17 microseconds. These values fall between prior ground-based measurements of direct return stroke emissions, and scattering-dominated on-orbit measurements. This work will promote better understanding of the correspondence between radio and optical measurements of lightning.

  2. Low-Impact Air-to-Ground Free-Space Optical Communication System Design and First Results

    CERN Document Server

    Carrasco-Casado, Alberto; Vergaz, Ricardo; Geday, Morten A; Sanchez-Pena, Jose M; Oton, Jose M

    2015-01-01

    An air-to-ground free-space optical communication system has been designed and partially developed. The design covers both the communications between the airborne and the ground station, and the acquisition, tracking and pointing. A strong effort has been made in order to achieve the minimum payload power, size and weight, for which a MEMS modulating retroreflector has been chosen. In the ground station, a new technique for fine pointing, based on a liquid crystal device, is proposed and will be demonstrated, as well as other improvements with the aim of optimizing the ground station performance.

  3. Thermal ground-water discharge and associated convective heat flux, Bruneau-Grand View area, southwest Idaho

    Science.gov (United States)

    Young, H.W.; Lewis, R.E.; Backsen, R.L.

    1979-01-01

    The Bruneau-Grand View area occupies about 1,100 square miles in southwest Idaho. The area has a rural population dependent on ground-water irrigation. Temperature of the ground water ranges from 15 C to more than 80 C. Ground water for irrigation is obtained from flowing and pumped wells. Discharge of thermal ground water from 104 irrigation wells and from 5 hot springs in 1978 was about 50,500 acre-feet. Convective heat flux from the geothermal system associated with this discharge was 4.97 x 10 to the 7th power calories per second. (Woodard-USGS)

  4. Wind Power - A Power Source Enabled by Power Electronics

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Chen, Zhe

    2004-01-01

    . The deregulation of energy has lowered the investment in bigger power plants, which means the need for new electrical power sources may be very high in the near future. Two major technologies will play important roles to solve the future problems. One is to change the electrical power production sources from...... electronics is changing from being a minor energy source to be acting as an important power source. By that wind power is also getting an added value....

  5. Power management system

    Science.gov (United States)

    Algrain, Marcelo C.; Johnson, Kris W.; Akasam, Sivaprasad; Hoff, Brian D.

    2007-10-02

    A method of managing power resources for an electrical system of a vehicle may include identifying enabled power sources from among a plurality of power sources in electrical communication with the electrical system and calculating a threshold power value for the enabled power sources. A total power load placed on the electrical system by one or more power consumers may be measured. If the total power load exceeds the threshold power value, then a determination may be made as to whether one or more additional power sources is available from among the plurality of power sources. At least one of the one or more additional power sources may be enabled, if available.

  6. Aerodynamic Ground Effect in Fruitfly Sized Insect Takeoff.

    Directory of Open Access Journals (Sweden)

    Dmitry Kolomenskiy

    Full Text Available Aerodynamic ground effect in flapping-wing insect flight is of importance to comparative morphologies and of interest to the micro-air-vehicle (MAV community. Recent studies, however, show apparently contradictory results of either some significant extra lift or power savings, or zero ground effect. Here we present a numerical study of fruitfly sized insect takeoff with a specific focus on the significance of leg thrust and wing kinematics. Flapping-wing takeoff is studied using numerical modelling and high performance computing. The aerodynamic forces are calculated using a three-dimensional Navier-Stokes solver based on a pseudo-spectral method with volume penalization. It is coupled with a flight dynamics solver that accounts for the body weight, inertia and the leg thrust, while only having two degrees of freedom: the vertical and the longitudinal horizontal displacement. The natural voluntary takeoff of a fruitfly is considered as reference. The parameters of the model are then varied to explore possible effects of interaction between the flapping-wing model and the ground plane. These modified takeoffs include cases with decreased leg thrust parameter, and/or with periodic wing kinematics, constant body pitch angle. The results show that the ground effect during natural voluntary takeoff is negligible. In the modified takeoffs, when the rate of climb is slow, the difference in the aerodynamic forces due to the interaction with the ground is up to 6%. Surprisingly, depending on the kinematics, the difference is either positive or negative, in contrast to the intuition based on the helicopter theory, which suggests positive excess lift. This effect is attributed to unsteady wing-wake interactions. A similar effect is found during hovering.

  7. Networked unattented ground sensors assesment

    Science.gov (United States)

    Bouguereau, Julien; Gattefin, Christian; Dupuy, Gilles

    2003-09-01

    Within the framework of the NATO AC 323 / RTO TG 25 group, relating to advanced concepts of acoustic and seismic technology for military applications, Technical Establishment of Bourges welcomed and organized a joint campaign of experiment intending to demonstrate the interest of a networked unattented ground sensors for vehicles detection and tracking in an area defense context. Having reminded the principle of vehicles tracking, this paper describes the progress of the test campaign and details particularly sensors and participants deployment, the solution of interoperability chosen by the group and the instrumentation used to acquire, network, process and publish in real-time data available during the test: meteorological data, trajectography data and targets detection reports data. Finally, some results of the campaign are presented.

  8. Science, values, and common ground.

    Science.gov (United States)

    Cuomo, Chris

    2003-11-01

    In this paper, I argue that there may be common ground shared by animal science and its critics insofar as animal scientists seek improvement in their field in four areas: the quality of their products, the quality of life for those who make their livelihood in food production, the fair treatment of human workers, and the humane treatment of animals. I also propose that there are fundamental differences between improvement motivated by profit and improvement motivated by ethical values. Positive moral change is sometimes revolutionary, although it is often a matter of promoting positive incremental changes and keeping one's attention on the effects of actions and attitudes. In conclusion, I suggest that in animal agriculture, positive change can be brought about by "getting closer" to the objects of scientific research, including nonhuman animals, by paying more attention to their welfare.

  9. Ground water budget analysis and cross-formational leakage in an arid basin.

    Science.gov (United States)

    Hutchison, William R; Hibbs, Barry J

    2008-01-01

    Ground water budget analysis in arid basins is substantially aided by integrated use of numerical models and environmental isotopes. Spatial variability of recharge, storage of water of both modern and pluvial age, and complex three-dimensional flow processes in these basins provide challenges to the development of a good conceptual model. Ground water age dating and mixing analysis with isotopic tracers complement standard hydrogeologic data that are collected and processed as an initial step in the development and calibration of a numerical model. Environmental isotopes can confirm or refute a priori assumptions of ground water flow, such as the general assumption that natural recharge occurs primarily along mountains and mountain fronts. Isotopes also serve as powerful tools during postaudits of numerical models. Ground water models provide a means of developing ground water budgets for entire model domains or for smaller regions within the model domain. These ground water budgets can be used to evaluate the impacts of pumping and estimate the magnitude of capture in the form of induced recharge from streams, as well as quantify storage changes within the system. The coupled analyses of ground water budget analysis and isotope sampling and analysis provide a means to confirm, refute, or modify conceptual models of ground water flow.

  10. Power conditioner without isolation transformer; Toransuresu power conditioner no shohin kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Okado, C.; Itami, T.; Kimoto, K. [Toshiba Corp., Tokyo (Japan)

    1996-10-27

    A light-weight downsized and high efficiency transformer-less type 4 kW power conditioner (inverter) has been developed. This power conditioner insures the system interconnection protection by monitoring the voltage of two single-phase three-line circuits. The power conditioner has weight of 17.5 kg and efficiency of 94%. Potential fluctuation of photovoltaic cells due to the switching of power devices at the inverter was reduced. Output capacity was reduced in the low input voltage range. Outflow of DC component was prevented in high accuracy by usually correcting the zero point drift of detector, and by using the current detector with excellent linearity. To detect the DC ground fault, and to trip the output side breaker locating at the ground fault current pass, a zero phase converter detection circuit has been developed, by which the DC component can be detected at the DC input side. As a result of performance verification, the efficiency, power factor, EMI level, protection of outflow of DC component, protection of ground fault, protection of single operation detection, and noise level were satisfied. This system is prospective for the diffusion of photovoltaic power generation in the future. 3 refs., 8 figs., 1 tab.

  11. DynaMax+ ground-tracking algorithm

    Science.gov (United States)

    Smock, Brandon; Gader, Paul; Wilson, Joseph

    2011-06-01

    In this paper, we propose a new method for performing ground-tracking using ground-penetrating radar (GPR). Ground-tracking involves identifying the air-ground interface, which is usually the dominant feature in a radar image but frequently is obscured or mimicked by other nearby elements. It is an important problem in landmine detection using vehicle-mounted systems because antenna motion, caused by bumpy ground, can introduce distortions in downtrack radar images, which ground-tracking makes it possible to correct. Because landmine detection is performed in real-time, any algorithm for ground-tracking must be able to run quickly, prior to other, more computationally expensive algorithms for detection. In this investigation, we first describe an efficient algorithm, based on dynamic programming, that can be used in real-time for tracking the ground. We then demonstrate its accuracy through a quantitative comparison with other proposed ground-tracking methods, and a qualitative comparison showing that its ground-tracking is consistent with human observations in challenging terrain.

  12. Low Voltage Power Supply Incorporating Ceramic Transformer

    CERN Document Server

    Imori, M

    2007-01-01

    A low voltage power supply provides the regulated output voltage of 1 V from the supply voltage around 48 V. The low voltage power supply incorporates a ceramic transformer which utilizes piezoelectric effect to convert voltage. The ceramic transformer isolates the secondary from the primary, thus providing the ground isolation between the supply and the output voltages. The ceramic transformer takes the place of the conventional magnetic transformer. The ceramic transformer is constructed from a ceramic bar and does not include any magnetic material. So the low voltage power supply can operate under a magnetic field. The output voltage is stabilized by feedback. A feedback loop consists of an error amplifier, a voltage controlled oscillator and a driver circuit. The amplitude ratio of the transformer has dependence on the frequency, which is utilized to stabilize the output voltage. The low voltage power supply is investigated on the analogy of the high voltage power supply similarly incorporating the cerami...

  13. Automated power management and control

    Science.gov (United States)

    Dolce, James L.

    1991-01-01

    A comprehensive automation design is being developed for Space Station Freedom's electric power system. A joint effort between NASA's Office of Aeronautics and Exploration Technology and NASA's Office of Space Station Freedom, it strives to increase station productivity by applying expert systems and conventional algorithms to automate power system operation. The initial station operation will use ground-based dispatches to perform the necessary command and control tasks. These tasks constitute planning and decision-making activities that strive to eliminate unplanned outages. We perceive an opportunity to help these dispatchers make fast and consistent on-line decisions by automating three key tasks: failure detection and diagnosis, resource scheduling, and security analysis. Expert systems will be used for the diagnostics and for the security analysis; conventional algorithms will be used for the resource scheduling.

  14. Multilateral Research Opportunities in Ground Analogs

    Science.gov (United States)

    Corbin, Barbara J.

    2015-01-01

    The global economy forces many nations to consider their national investments and make difficult decisions regarding their investment in future exploration. International collaboration provides an opportunity to leverage other nations' investments to meet common goals. The Humans In Space Community shares a common goal to enable safe, reliable, and productive human space exploration within and beyond Low Earth Orbit. Meeting this goal requires efficient use of limited resources and International capabilities. The International Space Station (ISS) is our primary platform to conduct microgravity research targeted at reducing human health and performance risks for exploration missions. Access to ISS resources, however, is becoming more and more constrained and will only be available through 2020 or 2024. NASA's Human Research Program (HRP) is actively pursuing methods to effectively utilize the ISS and appropriate ground analogs to understand and mitigate human health and performance risks prior to embarking on human exploration of deep space destinations. HRP developed a plan to use ground analogs of increasing fidelity to address questions related to exploration missions and is inviting International participation in these planned campaigns. Using established working groups and multilateral panels, the HRP is working with multiple Space Agencies to invite International participation in a series of 30- day missions that HRP will conduct in the US owned and operated Human Exploration Research Analog (HERA) during 2016. In addition, the HRP is negotiating access to Antarctic stations (both US and non-US), the German :envihab and Russian NEK facilities. These facilities provide unique capabilities to address critical research questions requiring longer duration simulation or isolation. We are negotiating release of international research opportunities to ensure a multilateral approach to future analog research campaigns, hoping to begin multilateral campaigns in the

  15. Estimating pumping time and ground-water withdrawals using energy-consumption data. Water-Resources Investigation

    Energy Technology Data Exchange (ETDEWEB)

    Hurr, R.T.; Litke, D.W.

    1989-01-01

    Evaluation of the hydrology of an aquifer requires knowledge about the volume of ground water in storage and also about the volume of ground-water withdrawals. Totalizer flow meters may be installed at pumping plants to measure withdrawals; however, it generally is impractical to equip all wells in an area with meters. A viable alternative is the use of rate-time methods to estimate withdrawals. The relation between power demand and pumping rate at a pumping plant can be described through the use of the power-consumption coefficient. Where equipment and hydrologic conditions are stable, this coefficient can be applied to total energy consumption at a site to estimate total ground-water withdrawals. Random sampling of power-consumption coefficients can be used to estimate area-wide ground-water withdrawals.

  16. Compact networked radars for Army unattended ground sensors

    Science.gov (United States)

    Wikner, David A.; Viveiros, Edward A.; Wellman, Ronald; Clark, John; Kurtz, Jim; Pulskamp, Jeff; Proie, Robert; Ivanov, Tony; Polcawich, Ronald G.; Adler, Eric D.

    2010-04-01

    The Army Research Laboratory is in partnership with the University of Florida - Electronics Communications Laboratory to develop compact radar technology and demonstrate that it is scalable to a variety of ultra-lightweight platforms (<10 lbs.) to meet Army mission needs in persistent surveillance, unattended ground sensor (UGS), unmanned systems, and man-portable sensor applications. The advantage of this compact radar is its steerable beam technology and relatively long-range capability compared to other small, battery-powered radar concepts. This paper will review the ongoing development of the sensor and presents a sample of the collected data thus far.

  17. Evaluation of Macrobend Loss on Long Distance Optical Ground Wire

    Directory of Open Access Journals (Sweden)

    M. F. M. Salleh

    2015-06-01

    Full Text Available Bend loss is a kind of loss that contributes to the power attenuation which is caused by the bending of optical fiber. For long distance optical fiber, bending might occur at joining point as there are many joining points along the link. Studies related to bend loss always relate the effect of bend radius on bend loss value. There is no study that relates the value of loss that can be affected by other factors like the natural environmental conditions. In this study, the evaluation of bend loss on existing long distance Optical Ground Wire (OPGW was studied since the cable was exposed to any climate condition.

  18. Ground Forces Modernization in China.

    Science.gov (United States)

    1987-08-11

    Soviets reasserted control in Manchuria , as far south as the old Chinese Eastern Railway line (Tsitsihar- Harbin -Vladivostock), they could cripple much...of China’s capability to challenge {. Soviet control of all of Manchuria . Because there is very little defensible terrain between Manchuria and the...Yangtze River, a Soviet conquest of Manchuria would effectively destroy Chinese military power throughout northern China and give the Soviet Union

  19. Mission aware energy saving strategies for Army ground vehicles

    Science.gov (United States)

    Dattathreya, Macam S.

    Fuel energy is a basic necessity for this planet and the modern technology to perform many activities on earth. On the other hand, quadrupled automotive vehicle usage by the commercial industry and military has increased fuel consumption. Military readiness of Army ground vehicles is very important for a country to protect its people and resources. Fuel energy is a major requirement for Army ground vehicles. According to a report, a department of defense has spent nearly $13.6 billion on fuel and electricity to conduct ground missions. On the contrary, energy availability on this plant is slowly decreasing. Therefore, saving energy in Army ground vehicles is very important. Army ground vehicles are embedded with numerous electronic systems to conduct missions such as silent and normal stationary surveillance missions. Increasing electrical energy consumption of these systems is influencing higher fuel consumption of the vehicle. To save energy, the vehicles can use any of the existing techniques, but they require complex, expensive, and time consuming implementations. Therefore, cheaper and simpler approaches are required. In addition, the solutions have to save energy according to mission needs and also overcome size and weight constraints of the vehicle. Existing research in the current literature do not have any mission aware approaches to save energy. This dissertation research proposes mission aware online energy saving strategies for stationary Army ground vehicles to save energy as well as to meet the electrical needs of the vehicle during surveillance missions. The research also proposes theoretical models of surveillance missions, fuzzy logic models of engine and alternator efficiency data, and fuzzy logic algorithms. Based on these models, two energy saving strategies are proposed for silent and normal surveillance type of missions. During silent mission, the engine is on and batteries power the systems. During normal surveillance mission, the engine is

  20. Solid-state retrodirective phased array concepts for microwave power transmission from Solar Power Satellite

    Science.gov (United States)

    Schroeder, K. G.; Petroff, I. K.

    1980-01-01

    Two prototype solid-state phased array systems concepts for potential use in the Solar Power Satellite are described. In both concepts, the beam is centered on the rectenna by means of phase conjugation of a pilot signal emanating from the ground. Also discussed is on-going solid-state amplifier development.

  1. A Social Identity and Social Power Perspective on Terrorism

    Directory of Open Access Journals (Sweden)

    Joshua David Wright

    2015-09-01

    Full Text Available This article presents a theoretical framework for understanding terrorism that is grounded in experimental work on social identity and social power. It is suggested that social identity salience and social power may be harnessed to reduce terrorist activity by reducing perceptions of threat from the view of terrorist organizations, by reducing perceived threat of terrorist activity from the view of potential targets, and by addressing distributions of and susceptibility to social power as it relates to acceptability of parochial altruism.

  2. Space-based monitoring of ground deformation

    Science.gov (United States)

    Nobakht Ersi, Fereydoun; Safari, Abdolreza; Gamse, Sonja

    2016-07-01

    Ground deformation monitoring is valuable to understanding of the behaviour of natural phenomena. Space-Based measurement systems such as Global Positioning System are useful tools for continuous monitoring of ground deformation. Ground deformation analysis based on space geodetic techniques have provided a new, more accurate, and reliable source of information for geodetic positioning which is used to detect deformations of the Ground surface. This type of studies using displacement fields derived from repeated measurments of space-based geodetic networks indicates how crucial role the space geodetic methods play in geodynamics. The main scope of this contribution is to monitor of ground deformation by obtained measurements from GPS sites. We present ground deformation analysis in three steps: a global congruency test on daily coordinates of permanent GPS stations to specify in which epochs deformations occur, the localization of the deformed GPS sites and the determination of deformations.

  3. Power Sources for Ultra Low Power Electronics

    Science.gov (United States)

    2000-06-12

    DARPA asked JASON to examine the issue of power sources for low power electronics with a specific emphasis on the properties of nuclear batteries and...integrated power sources combining power and electronics. During the 1998 Summer Study a workshop was held to provide background for the study, with

  4. Space Solar Power Technology Demonstration for Lunar Polar Applications: Laser-Photovoltaic Wireless Power Transmission

    Science.gov (United States)

    Henley, M. W.; Fikes, J. C.; Howell, J.; Mankins, J. C.; Howell, Joe T. (Technical Monitor)

    2002-01-01

    Space Solar Power technology offers unique benefits for near-term NASA space science missions, which can mature this technology for other future applications. "Laser-Photo-Voltaic Wireless Power Transmission" (Laser-PV WPT) is a technology that uses a laser to beam power to a photovoltaic receiver, which converts the laser's light into electricity. Future Laser-PV WPT systems may beam power from Earth to satellites or large Space Solar Power satellites may beam power to Earth, perhaps supplementing terrestrial solar photo-voltaic receivers. In a near-term scientific mission to the moon, Laser-PV WPT can enable robotic operations in permanently shadowed lunar polar craters, which may contain ice. Ground-based technology demonstrations are proceeding, to mature the technology for this initial application, in the moon's polar regions.

  5. Simple system for locating ground loops.

    Science.gov (United States)

    Bellan, P M

    2007-06-01

    A simple low-cost system for rapid identification of the cables causing ground loops in complex instrumentation configurations is described. The system consists of an exciter module that generates a 100 kHz ground loop current and a detector module that determines which cable conducts this test current. Both the exciter and detector are magnetically coupled to the ground circuit so there is no physical contact to the instrumentation system under test.

  6. SpinSat Mission Ground Truth Characterization

    Science.gov (United States)

    2014-09-01

    SpinSat Mission Ground Truth Characterization Andrew Nicholas, Ted Finne, Ivan Galysh, Anthony Mai, Jim Yen Naval Research Laboratory, Washington...mission overview, ground truth characterization and unique SSA observation opportunities of the mission. 1. MISSION CONCEPT The Naval Research...2. REPORT TYPE 3. DATES COVERED 00-00-2014 to 00-00-2014 4. TITLE AND SUBTITLE SpinSat Mission Ground Truth Characterization 5a. CONTRACT

  7. Test and Evaluation of Autonomous Ground Vehicles

    OpenAIRE

    Yang Sun; Guangming Xiong; Weilong Song; Jianwei Gong; Huiyan Chen

    2014-01-01

    A preestablished test and evaluation system will benefit the development of autonomous ground vehicles. This paper proposes a design method for a scientific and comprehensive test and evaluation system for autonomous ground vehicles competitions. It can better guide and regulate the development of China’s autonomous ground vehicles. The test and evaluation system includes the test contents, the test environment, the test methods, and the evaluation methods. Using a hierarchical design approac...

  8. Grounded theory methodology--narrativity revisited.

    Science.gov (United States)

    Ruppel, Paul Sebastian; Mey, Günter

    2015-06-01

    This article aims to illuminate the role of narrativity in Grounded Theory Methodology and to explore an approach within Grounded Theory Methodology that is sensitized towards aspects of narrativity. The suggested approach takes into account narrativity as an aspect of the underlying data. It reflects how narrativity could be conceptually integrated and systematically used for shaping the way in which coding, category development and the presentation of results in a Grounded Theory Methodology study proceed.

  9. Systems definition space based power conversion systems: Executive summary

    Science.gov (United States)

    1977-01-01

    Potential space-located systems for the generation of electrical power for use on earth were investigated. These systems were of three basic types: (1) systems producing electrical power from solar energy; (2) systems producing electrical power from nuclear reactors; (3) systems for augmenting ground-based solar power plants by orbital sunlight reflectors. Configurations implementing these concepts were developed through an optimization process intended to yield the lowest cost for each. A complete program was developed for each concept, identifying required production rates, quantities of launches, required facilities, etc. Each program was costed in order to provide the electric power cost appropriate to each concept.

  10. Power theories for improved power quality

    CERN Document Server

    Pasko, Marian

    2012-01-01

    Power quality describes a set of parameters of electric power and the load’s ability to function properly under specific conditions. It is estimated that problems relating to power quality costs the European industry hundreds of billions of Euros annually. In contrast, financing for the prevention of these problems amount to fragments of these costs. Power Theories for Improved Power Quality addresses this imbalance by presenting and assessing a range of methods and problems related to improving the quality of electric power supply. Focusing particularly on active compensators and the DSP based control algorithms, Power Theories for Improved Power Quality introduces the fundamental problems of electrical power. This introduction is followed by chapters which discuss: •‘Power theories’ including their historical development and application to practical problems, •operational principles of active compensator’s DSP control based algorithms using examples and results from laboratory research, and •t...

  11. Suomi NPP Ground System Performance

    Science.gov (United States)

    Grant, K. D.; Bergeron, C.

    2013-12-01

    The National Oceanic and Atmospheric Administration (NOAA) and National Aeronautics and Space Administration (NASA) are jointly acquiring the next-generation civilian weather and environmental satellite system: the Joint Polar Satellite System (JPSS). JPSS will replace the afternoon orbit component and ground processing system of the current Polar-orbiting Operational Environmental Satellites (POES) managed by NOAA. The JPSS satellites will carry a suite of sensors designed to collect meteorological, oceanographic, climatological and geophysical observations of the Earth. The first satellite in the JPSS constellation, known as the Suomi National Polar-orbiting Partnership (Suomi NPP) satellite, was launched on 28 October 2011, and is currently undergoing product calibration and validation activities. As products reach a beta level of maturity, they are made available to the community through NOAA's Comprehensive Large Array-data Stewardship System (CLASS). CGS's data processing capability processes the satellite data from the Joint Polar Satellite System satellites to provide environmental data products (including Sensor Data Records (SDRs) and Environmental Data Records (EDRs)) to NOAA and Department of Defense (DoD) processing centers operated by the United States government. CGS is currently processing and delivering SDRs and EDRs for Suomi NPP and will continue through the lifetime of the Joint Polar Satellite System programs. Following the launch and sensor activation phase of the Suomi NPP mission, full volume data traffic is now flowing from the satellite through CGS's C3, data processing, and data delivery systems. Ground system performance is critical for this operational system. As part of early system checkout, Raytheon measured all aspects of data acquisition, routing, processing, and delivery to ensure operational performance requirements are met, and will continue to be met throughout the mission. Raytheon developed a tool to measure, categorize, and

  12. Measurement of ground motion in various sites

    Energy Technology Data Exchange (ETDEWEB)

    Bialowons, W.; Amirikas, R.; Bertolini, A.; Kruecker, D.

    2007-04-15

    Ground vibrations may affect low emittance beam transport in linear colliders, Free Electron Lasers (FEL) and synchrotron radiation facilities. This paper is an overview of a study program to measure ground vibrations in various sites which can be used for site characterization in relation to accelerator design. Commercial broadband seismometers have been used to measure ground vibrations and the resultant database is available to the scientific community. The methodology employed is to use the same equipment and data analysis tools for ease of comparison. This database of ground vibrations taken in 19 sites around the world is first of its kind. (orig.)

  13. Optimized ground coupled heat pump mechanical package

    Energy Technology Data Exchange (ETDEWEB)

    Catan, M.A.

    1987-01-01

    This project addresses the question of how well a ground coupled heat pump system could perform with a heat pump which was designed specifically for such systems operating in a northern climate. Conventionally, systems are designed around water source heat pumps which are not designed for ground coupled heat pump application. The objective of the project is to minimize the life cycle cost for a ground coupled system given the freedom to design the heat pump and the ground coil in concert. In order to achieve this objective a number of modeling tools were developed which will likely be of interest in their own right.

  14. Grounded cognition: past, present, and future.

    Science.gov (United States)

    Barsalou, Lawrence W

    2010-10-01

    Thirty years ago, grounded cognition had roots in philosophy, perception, cognitive linguistics, psycholinguistics, cognitive psychology, and cognitive neuropsychology. During the next 20 years, grounded cognition continued developing in these areas, and it also took new forms in robotics, cognitive ecology, cognitive neuroscience, and developmental psychology. In the past 10 years, research on grounded cognition has grown rapidly, especially in cognitive neuroscience, social neuroscience, cognitive psychology, social psychology, and developmental psychology. Currently, grounded cognition appears to be achieving increased acceptance throughout cognitive science, shifting from relatively minor status to increasing importance. Nevertheless, researchers wonder whether grounded mechanisms lie at the heart of the cognitive system or are peripheral to classic symbolic mechanisms. Although grounded cognition is currently dominated by demonstration experiments in the absence of well-developed theories, the area is likely to become increasingly theory driven over the next 30 years. Another likely development is the increased incorporation of grounding mechanisms into cognitive architectures and into accounts of classic cognitive phenomena. As this incorporation occurs, much functionality of these architectures and phenomena is likely to remain, along with many original mechanisms. Future theories of grounded cognition are likely to be heavily influenced by both cognitive neuroscience and social neuroscience, and also by developmental science and robotics. Aspects from the three major perspectives in cognitive science-classic symbolic architectures, statistical/dynamical systems, and grounded cognition-will probably be integrated increasingly in future theories, each capturing indispensable aspects of intelligence.

  15. Grounded Theory Approach in Social Research

    Directory of Open Access Journals (Sweden)

    Dr Venkat Pulla

    2014-11-01

    Full Text Available This paper discusses Grounded Theory, which is one of the newer methodologies becoming popular with social researchers since its evolution in the late 1960s. The paper discusses the principles and processes of the Grounded Theory and then explores the nature of codes, coding process and the concept of saturation. It then goes on to discuss the pros and cons, arguments for and against the use of Grounded Theory methodology in social research and explores the applicability of this methodology in producing sound theoretical basis for practice. Selected narratives from the author’s recent studies are used to explain the processes of Grounded Theory methodology.

  16. Advanced Ground Systems Maintenance Anomaly Detection Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This project will develop the capability to identify anomalous conditions (indications to potential impending system failure) in ground system operations before such...

  17. Women, Power, and Libraries.

    Science.gov (United States)

    Schuman, Patricia Glass

    1984-01-01

    Discusses the concept of power in the context of women and the library profession, citing views of power by Max Weber, John Kenneth Galbraith, Letty Cottin Pogrebin, and Rosabeth Moss Kantor. Male power and female submission, defining power, organizing for power, and sharing power are highlighted. A 12-item bibliography is included. (EJS)

  18. Wind power - a power source now enabled by power electronics

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Iov, Florin

    2007-01-01

    energy at the end-user should be set up. Deregulation of energy has lowered the investment in larger power plants, which means the need for new electrical power sources may be increased in the near future. Two major technologies will play important roles to solve the future problems. One is to change...... the electrical power production sources from the conventional, fossil (and short term) based energy sources to renewable energy resources. Another is to use high efficient power electronics in power generation, power transmission/distribution and end-user application. This paper discuss the most emerging...... renewable energy sources, wind energy, which by means of power electronics are changing from being minor energy sources to be acting as important power sources in the energy system....

  19. Wind power - a power source now enabled by power electronics

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Iov, Florin

    2007-01-01

    energy at the end-user should be set up. Deregulation of energy has lowered the investment in larger power plants, which means the need for new electrical power sources may be increased in the near future. Two major technologies will play important roles to solve the future problems. One is to change...... renewable energy sources, wind energy, which by means of power electronics are changing from being minor energy sources to be acting as important power sources in the energy system....

  20. 2011 Ground Testing Highlights Article

    Science.gov (United States)

    Ross, James C.; Buchholz, Steven J.

    2011-01-01

    Two tests supporting development of the launch abort system for the Orion MultiPurpose Crew Vehicle were run in the NASA Ames Unitary Plan wind tunnel last year. The first test used a fully metric model to examine the stability and controllability of the Launch Abort Vehicle during potential abort scenarios for Mach numbers ranging from 0.3 to 2.5. The aerodynamic effects of the Abort Motor and Attitude Control Motor plumes were simulated using high-pressure air flowing through independent paths. The aerodynamic effects of the proximity to the launch vehicle during the early moments of an abort were simulated with a remotely actuated Service Module that allowed the position relative to the Crew Module to be varied appropriately. The second test simulated the acoustic environment around the Launch Abort Vehicle caused by the plumes from the 400,000-pound thrust, solid-fueled Abort Motor. To obtain the proper acoustic characteristics of the hot rocket plumes for the flight vehicle, heated Helium was used. A custom Helium supply system was developed for the test consisting of 2 jumbo high-pressure Helium trailers, a twelve-tube accumulator, and a 13MW gas-fired heater borrowed from the Propulsion Simulation Laboratory at NASA Glenn Research Center. The test provided fluctuating surface pressure measurements at over 200 points on the vehicle surface that have now been used to define the ground-testing requirements for the Orion Launch Abort Vehicle.

  1. Ground Collision Avoidance System (Igcas)

    Science.gov (United States)

    Skoog, Mark A (Inventor); Prosser, Kevin (Inventor); Hook, Loyd (Inventor)

    2017-01-01

    The present invention is a system and method for aircraft ground collision avoidance (iGCAS) comprising a modular array of software, including a sense own state module configured to gather data to compute trajectory, a sense terrain module including a digital terrain map (DTM) and map manger routine to store and retrieve terrain elevations, a predict collision threat module configured to generate an elevation profile corresponding to the terrain under the trajectory computed by said sense own state module, a predict avoidance trajectory module configured to simulate avoidance maneuvers ahead of the aircraft, a determine need to avoid module configured to determine which avoidance maneuver should be used, when it should be initiated, and when it should be terminated, a notify Module configured to display each maneuver's viability to the pilot by a colored GUI, a pilot controls module configured to turn the system on and off, and an avoid module configured to define how an aircraft will perform avoidance maneuvers through 3-dimensional space.

  2. Urban ambiances as common ground?

    Directory of Open Access Journals (Sweden)

    Jean-Paul Thibaud

    2014-07-01

    Full Text Available The aim of this paper is to point out various arguments which question ambiance as a common ground of everyday urban experience. Such a project involves four major points. First, we have to move beyond the exclusive practical aspects of everyday life and bring the sensory to the forefront. Under such conditions, sensory cultures emerge where feeling and acting come together. Second, we must put common experience into perspectiveby initiating a dual dynamics of socialising the sensory and sensitising social life. Ambiances involve a complex web comprised of an ‘existential’ dimension (empathy with the ambient world, a ‘contextual’ dimension (degree of presence in the situation, and an ‘interactional’ dimension (forms of sociability expressed in the tonality. Third, we have to initiate a political ecology of ambiances in order to better understand how ambiances deal with fundamental design and planning issues. Far from being neutral, the notion of ambiance appears to be bound up with the socio-aesthetic strategies underpinning changes to the sensory urban environment of the future. Fourth, we have to question what in situ experience is all about. Three major research pointers enable to address this issue: the embodiment of situated experiences, the porous nature of sensory spaces, and the sensory efficiency of the build environment. Ambiances sensitize urban design as well as social lifeforms.

  3. Iowa ground-water quality

    Science.gov (United States)

    Buchmiller, R.C.; Squillace, P.J.; Drustrup, R.D.

    1987-01-01

    The population served by ground-water supplies in Iowa (fig. L4) is estimated to be about 2,392,000, or 82 percent of the total population (U.S. Geological Survey, 1985, p. 211). The population of Iowa is distributed fairly uniformly throughout the State (fig. IB), with 59 percent residing in rural areas or towns of less than 10,000 (U.S. Bureau of the Census, 1982). Surficial aquifers, the Jordan aquifer, and aquifers that form the uppermost bedrock aquifer in a particular area are most commonly used for drinking-water supplies and usually provide ample amounts of good quality water. However, naturally occurring properties or substances such as hardness, dissolved solids, and radioactivity limit the use of water for drinking purposes in some areas of each of the five principal aquifers (fig. 2/4). Median concentrations of nitrate in all aquifers and radium-226 in all aquifers except the Jordan are within the primary drinking-water standards established by the U.S. Environmental Protection Agency (1986a). Median concentrations for dissolved solids in the surficial, Dakota, and Jordan aquifers exceed secondary drinking-water standards established by the U.S. Environmental Protection Agency (1986b).

  4. Infrasound from ground to space

    Science.gov (United States)

    Bowman, Daniel Charles

    Acoustic detector networks are usually located on the Earth's surface. However, these networks suffer from shortcomings such as poor detection range and pervasive wind noise. An alternative is to deploy acoustic sensors on high altitude balloons. In theory, such platforms can resolve signals arriving from great distances, acquire others that never reach the surface at all, and avoid wind noise entirely. This dissertation focuses on scientific advances, instrumentation, and analytical techniques resulting from the development of such sensor arrays. Results from infrasound microphones deployed on balloon flights in the middle stratosphere are described, and acoustic sources such as the ocean microbarom and building ventilation systems are discussed. Electromagnetic noise originating from the balloon, flight system, and other payloads is shown to be a pervasive issue. An experiment investigating acoustic sensor calibration at low pressures is presented, and implications for high altitude recording are considered. Outstanding challenges and opportunities in sound measurement using sensors embedded in the free atmosphere are outlined. Acoustic signals from field scale explosions designed to emulate volcanic eruptions are described, and their generation mechanisms modeled. Wave forms recorded on sensors suspended from tethered helium balloons are compared with those detected on ground stations during the experiment. Finally, the Hilbert-Huang transform, a high time resolution spectral analysis method for nonstationary and nonlinear time series, is presented.

  5. The Roots of Grounded Theory

    Directory of Open Access Journals (Sweden)

    Barney G Glaser, Ph.D.; Hon Ph.D.

    2006-06-01

    Full Text Available I studied sociology at Stanford 1948 to 1952, which was partially fine but limited in those days. But then I knew I wanted to be a sociologist. Returning to the USA from the army in 1955 to study sociology at Columbia confirmed my goals. I bought the program 100% on doing sociology as my life work. All I do is sociology in every facet of life; work, recreation, family etc. My life is sociology driven and directed.Now let me give you a quote from Barton’s (1955, p.246 article of Paul F. Lazarsfeld [PFL], “Analyzing the logic of research operations to clarify concepts remained a key to PFL’s life”. It has been the key to my life also.“All is data” – that now sloganized tenet of Grounded Theory [GT] – clearly came from PFL per Barton’s words. Robert K. Merton’s [RKM] brief flicker of light – to admit to emergence (see Barton, p. 255 – became the key to GT’s theoretical stance.

  6. Cross Validation of Spaceborne and Ground Polarimetric Radar Snowfall Retrievals

    Science.gov (United States)

    Wen, Y.; Hong, Y.; Cao, Q.; Kirstetter, P.; Gourley, J. J.; Zhang, J.

    2013-12-01

    Snow, as a primary contribution to regional or even global water budgets is of critical importance to our society. For large-scale weather monitoring and global climate studies, satellite-based snowfall observations with ground validations have become highly desirable. Ground-based polarimetric weather radar is the powerful validation tool that provides physical insight into the development and interpretation of spaceborne snowfall retrievals. This study aims to compare and resolve discrepancies in snowfall detection and estimation between Cloud Profiling Radar (CPR) on board NASA's Cloudsat satellite and new polarimetric National Mosaic and Multi-sensor QPE (NMQ) system (Q3) developed by OU and NOAA/NSSL scientists. The Global Precipitation Measurement Mission with its core satellite scheduled for launch in 2014 will carry active and passive microwave instrumentation anticipated to detect and estimate snowfall or snowpack. This study will potentially serve as the basis for global validation of space-based snowfall products and also invite synergistic development of coordinated space-ground multisensor snowfall products.

  7. The ground truth about metadata and community detection in networks.

    Science.gov (United States)

    Peel, Leto; Larremore, Daniel B; Clauset, Aaron

    2017-05-01

    Across many scientific domains, there is a common need to automatically extract a simplified view or coarse-graining of how a complex system's components interact. This general task is called community detection in networks and is analogous to searching for clusters in independent vector data. It is common to evaluate the performance of community detection algorithms by their ability to find so-called ground truth communities. This works well in synthetic networks with planted communities because these networks' links are formed explicitly based on those known communities. However, there are no planted communities in real-world networks. Instead, it is standard practice to treat some observed discrete-valued node attributes, or metadata, as ground truth. We show that metadata are not the same as ground truth and that treating them as such induces severe theoretical and practical problems. We prove that no algorithm can uniquely solve community detection, and we prove a general No Free Lunch theorem for community detection, which implies that there can be no algorithm that is optimal for all possible community detection tasks. However, community detection remains a powerful tool and node metadata still have value, so a careful exploration of their relationship with network structure can yield insights of genuine worth. We illustrate this point by introducing two statistical techniques that can quantify the relationship between metadata and community structure for a broad class of models. We demonstrate these techniques using both synthetic and real-world networks, and for multiple types of metadata and community structures.

  8. Nuclear ground-state masses and deformations: FRDM(2012)

    CERN Document Server

    Moller, P; Ichikawa, T; Sagawa, H

    2015-01-01

    We tabulate the atomic mass excesses and binding energies, ground-state shell-plus-pairing corrections, ground-state microscopic corrections, and nuclear ground-state deformations of 9318 nuclei ranging from $^{16}$O to $A=339$. The calculations are based on the finite-range droplet macroscopic model and the folded-Yukawa single-particle microscopic model. Relative to our FRDM(1992) mass table in {\\sc Atomic Data and Nuclear Data Tables} [{\\bf 59} 185 (1995)], the results are obtained in the same model, but with considerably improved treatment of deformation and fewer of the approximations that were necessary earlier, due to limitations in computer power. The more accurate execution of the model and the more extensive and more accurate experimental mass data base now available allows us to determine one additional macroscopic-model parameter, the density-symmetry coefficient $L$, which was not varied in the previous calculation, but set to zero. Because we now realize that the FRDM is inaccurate for some high...

  9. NASA's mobile satellite communications program; ground and space segment technologies

    Science.gov (United States)

    Naderi, F.; Weber, W. J.; Knouse, G. H.

    1984-10-01

    This paper describes the Mobile Satellite Communications Program of the United States National Aeronautics and Space Administration (NASA). The program's objectives are to facilitate the deployment of the first generation commercial mobile satellite by the private sector, and to technologically enable future generations by developing advanced and high risk ground and space segment technologies. These technologies are aimed at mitigating severe shortages of spectrum, orbital slot, and spacecraft EIRP which are expected to plague the high capacity mobile satellite systems of the future. After a brief introduction of the concept of mobile satellite systems and their expected evolution, this paper outlines the critical ground and space segment technologies. Next, the Mobile Satellite Experiment (MSAT-X) is described. MSAT-X is the framework through which NASA will develop advanced ground segment technologies. An approach is outlined for the development of conformal vehicle antennas, spectrum and power-efficient speech codecs, and modulation techniques for use in the non-linear faded channels and efficient multiple access schemes. Finally, the paper concludes with a description of the current and planned NASA activities aimed at developing complex large multibeam spacecraft antennas needed for future generation mobile satellite systems.

  10. NASA's mobile satellite communications program; ground and space segment technologies

    Science.gov (United States)

    Naderi, F.; Weber, W. J.; Knouse, G. H.

    1984-01-01

    This paper describes the Mobile Satellite Communications Program of the United States National Aeronautics and Space Administration (NASA). The program's objectives are to facilitate the deployment of the first generation commercial mobile satellite by the private sector, and to technologically enable future generations by developing advanced and high risk ground and space segment technologies. These technologies are aimed at mitigating severe shortages of spectrum, orbital slot, and spacecraft EIRP which are expected to plague the high capacity mobile satellite systems of the future. After a brief introduction of the concept of mobile satellite systems and their expected evolution, this paper outlines the critical ground and space segment technologies. Next, the Mobile Satellite Experiment (MSAT-X) is described. MSAT-X is the framework through which NASA will develop advanced ground segment technologies. An approach is outlined for the development of conformal vehicle antennas, spectrum and power-efficient speech codecs, and modulation techniques for use in the non-linear faded channels and efficient multiple access schemes. Finally, the paper concludes with a description of the current and planned NASA activities aimed at developing complex large multibeam spacecraft antennas needed for future generation mobile satellite systems.

  11. Guide to Louisiana's ground-water resources

    Science.gov (United States)

    Stuart, C.G.; Knochenmus, D.D.; McGee, B.D.

    1994-01-01

    Ground water is one of the most valuable and abundant natural resources of Louisiana. Of the 4-.4 million people who live in the State, 61 percent use ground water as a source for drinking water. Most industrial and rural users and half of the irrigation users in the State rely on ground water. Quantity, however, is not the only aspect that makes ground water so valuable; quality also is important for its use. In most areas, little or no water treatment is required for drinking water and industrial purposes. Knowledge of Louisiana's ground-water resources is needed to ensure proper development and protection of this valuable resource. This report is designed to inform citizens about the availability and quality of ground water in Louisiana. It is not intended as a technical reference; rather, it is a guide to ground water and the significant role this resource plays in the state. Most of the ground water that is used in the State is withdrawn from 13 aquifers and aquifer systems: the Cockfield, Sparta, and Carrizo-Wilcox aquifersin northern Louisiana; Chicot aquifer system, Evangeline aquifer, Jasper aquifer system, and Catahoula aquifer in central and southwestern Louisiana; the Chicot equivalent, Evangeline equivalent, and Jasper equivalent aquifer systems in southeastern Louisiana; and the MississippiRiver alluvial, Red River alluvial, and upland terrace aquifers that are statewide. Ground water is affected by man's activities on the land surface, and the major ground-water concerns in Louisiana are: (1) contamination from surface disposal of hazardous waste, agricultural chemicals, and petroleum products; (2) contamination from surface wastes and saltwater through abandoned wells; (3) saltwater encroachment; and (4) local overdevelopment. Information about ground water in Louisiana is extensive and available to the public. Several State and Federal agencies provide published and unpublished material upon request.

  12. Future Photovoltaic Power Generation for Space-Based Power Utilities

    Science.gov (United States)

    Bailey, S.; Landis, G.; Raffaelle, R.; Hepp, A.

    2002-01-01

    A recent NASA program, Space Solar Power Exploratory Research and Technology (SERT), investigated the technologies needed to provide cost-competitive ground baseload electrical power from space based solar energy conversion. This goal mandated low cost, light weight gigawatt (GW) power generation. Investment in solar power generation technologies would also benefit high power military, commercial and science missions. These missions are generally those involving solar electric propulsion, surface power systems to sustain an outpost or a permanent colony on the surface of the moon or mars, space based lasers or radar, or as large earth orbiting power stations which can serve as central utilities for other orbiting spacecraft, or as in the SERT program, potentially beaming power to the earth itself. This paper will discuss requirements for the two latter options, the current state of the art of space solar cells, and a variety of both evolving thin film cells as well as new technologies which may impact the future choice of space solar cells for a high power mission application. The space world has primarily transitioned to commercially available III-V (GaInP/GaAs/Ge) cells with 24-26% air mass zero (AMO) efficiencies. Research in the III-V multi-junction solar cells has focused on fabricating either lattice-mismatched materials with optimum stacking bandgaps or new lattice matched materials with optimum bandgaps. In the near term this will yield a 30% commercially available space cell and in the far term possibly a 40% cell. Cost reduction would be achieved if these cells could be grown on a silicon rather than a germanium substrate since the substrate is ~65% of the cell cost or, better yet, on a polyimide or possibly a ceramic substrate. An overview of multi-junction cell characteristics will be presented here. Thin film cells require substantially less material and have promised the advantage of large area, low cost manufacturing. However, space cell requirements

  13. Warming up for sleep? - ground squirrels sleep during arousals from hibernation

    NARCIS (Netherlands)

    Daan, Serge; Barnes, Brian M.; Strijkstra, Arjen M.

    1991-01-01

    Hypothermia during mammalian hibernation is periodically interrupted by arousals to euthermy, the function of which is unknown. We report that arctic ground squirrels (Spermophilus parryii) consistently sleep during these arousals, and that their EEG shows the decrease in slow wave activity (δ power

  14. Ground-Coupled Heating-Cooling Systems in Urban Areas: How Sustainable Are They?

    Science.gov (United States)

    Younger, Paul L.

    2008-01-01

    Ground-coupled heating-cooling systems (GCHCSs) exchange heat between the built environment and the subsurface using pipework buried in trenches or boreholes. If heat pumps in GCHCSs are powered by "green electricity," they offer genuine carbon-free heating-cooling; for this reason, there has been a surge in the technology in recent years.…

  15. H-Bridge Transformerless Inverter with Common Ground for Single-Phase Solar-Photovoltaic System

    DEFF Research Database (Denmark)

    Siwakoti, Yam Prasad; Blaabjerg, Frede

    2017-01-01

    This paper proposes a new single-phase H-Bridge transformerless inverter with common ground for grid-connected photovoltaic systems (hereafter it is called ‘Siwakoti-H’ inverter). The inverter works on the principle of flying capacitor and consists of only four power switches (two reverse blockin...

  16. An analysis of AMTEC, multi-cell ground-demo for the Pluto/Express mission

    Energy Technology Data Exchange (ETDEWEB)

    Tournier, J.M.; El-Genk, M.S.

    1998-07-01

    Results of recent tests of an 8-cell, AMTEC ground-demo are analyzed and the performance of individual cells compared. The ground-demo produced a peak electric power of 27 W{sub e} at an output voltage of 16 V, when tested at hot and cold side temperatures of 1123 K and 553 K. The electric power output and terminal voltage of the individual cells, however, differed by as much as 25%, from 2.94 to 3.76 W{sub e}, and 1.73 to 2.21 V, respectively. These variations were attributed to differences in: (a) contact resistance between electrode / BASE / current collector; (b) current (or electrons) leakage between anode and cathode electrodes through the metal-ceramic braze joint between BASE tubes and support plate; and (c) the charge-exchange polarization losses. Model's predictions compared very well with measured voltage and electric power output of individual cells and of the ground-demo. At the operating conditions for the Pluto/Express spacecraft (T{sub hot} {approximately} 1200 K, T{sub cd} {approximately} 573 K), the best performing ground-demo cell would have delivered 5 W{sub e} at an output voltage of 3 V. These values, however, are still significantly lower than those needed to meet the Pluto/Express mission power requirements (8.2 W{sub e} at 3.5 V, per cell).

  17. Ground-Coupled Heating-Cooling Systems in Urban Areas: How Sustainable Are They?

    Science.gov (United States)

    Younger, Paul L.

    2008-01-01

    Ground-coupled heating-cooling systems (GCHCSs) exchange heat between the built environment and the subsurface using pipework buried in trenches or boreholes. If heat pumps in GCHCSs are powered by "green electricity," they offer genuine carbon-free heating-cooling; for this reason, there has been a surge in the technology in recent…

  18. Strong Ground-Motion Prediction in Seismic Hazard Analysis: PEGASOS and Beyond

    Science.gov (United States)

    Scherbaum, F.; Bommer, J. J.; Cotton, F.; Bungum, H.; Sabetta, F.

    2005-12-01

    The SSHAC Level 4 approach to probabilistic seismic hazard analysis (PSHA), which could be considered to define the state-of-the-art in PSHA using multiple expert opinions, has been fully applied only twice, firstly in the multi-year Yucca Mountain study and subsequently (2002-2004) in the PEGASOS project. The authors of this paper participated as ground-motion experts in this latter project, the objective of which was comprehensive seismic hazard analysis for four nuclear power plant sites in Switzerland, considering annual exceedance frequencies down to 1/10000000. Following SSHAC procedure, particular emphasis was put on capturing both the aleatory and epistemic uncertainties. As a consequence, ground motion prediction was performed by combining several empirical ground motion models within a logic tree framework with the weights on each logic tree branch expressing the personal degree-of-belief of each ground-motion expert. In the present paper, we critically review the current state of ground motion prediction methodology in PSHA in particular for regions of low seismicity. One of the toughest lessons from PEGASOS was that in systematically and rigorously applying the laws of uncertainty propagation to all of the required conversions and adjustments of ground motion models, a huge price has to be paid in an ever-growing aleatory variability. Once this path has been followed, these large sigma values will drive the hazard, particularly for low annual frequencies of exceedance. Therefore, from a post-PEGASOS perspective, the key issues in the context of ground-motion prediction for PSHA for the near future are to better understand the aleatory variability of ground motion and to develop suites of ground-motion prediction equations that employ the same parameter definitions. The latter is a global rather than a regional challenge which might be a desirable long-term goal for projects similar to the PEER NGA (Pacific Earthquake Engineering Research Center, Next

  19. Dynamic power flow controllers

    Science.gov (United States)

    Divan, Deepakraj M.; Prasai, Anish

    2017-03-07

    Dynamic power flow controllers are provided. A dynamic power flow controller may comprise a transformer and a power converter. The power converter is subject to low voltage stresses and not floated at line voltage. In addition, the power converter is rated at a fraction of the total power controlled. A dynamic power flow controller controls both the real and the reactive power flow between two AC sources having the same frequency. A dynamic power flow controller inserts a voltage with controllable magnitude and phase between two AC sources; thereby effecting control of active and reactive power flows between two AC sources.

  20. In Situ Measurement of the Undisturbed Ground Temperature for Ground Source Heat Pump System

    Institute of Scientific and Technical Information of China (English)

    ZHOU Ya-su

    2008-01-01

    The undisturbed ground are important for design of the ground heat exchangers in ground source heat pump (GSHP) systems. In this paper, the undisturbed ground temperatures measured in two different methods are presented. The investigation was carried out in two cases. The temperature measured with the direct method is assumed to give the correct undisturbed ground temperature profile. The temperature measured with indirect method overestimates the undisturbed ground temperature by 2.1℃ and 1.7℃. This difference is mainly caused by the circulation pump and ambient air to the fluid. Therefore, the results that are decreased about 2℃ as compared with the indirect measured are recommended to estimate the undisturbed ground temperature in situ measuring. A smaller pump or deeper borehole or mild weather would result in a more correct temperature. Because the undisturbed ground temperature is affected by many factors. Whether or not these conclusions are correct to other areas, this would need further investigation.

  1. Transition and verification of ground fault protection method in Hokuriku Shinkansen line

    Directory of Open Access Journals (Sweden)

    Michiteru Koyanagi

    2016-01-01

    Full Text Available The electrical discharge gaps called S type horn are applied to the ground fault detection and protection in AC traction power supply system for high speed railway called Shinkansen. In this method, the earth resistance of the steel pipe pillar is an important factor for the ground fault protection by the electrical discharge. In this study, the analyses of the transient characteristics of grounding fault are carried out by using EMTP, and the ground resistance value required to trigger discharge at S type horn was calculated. Moreover, the protection effect of a discharge gap called GP the substation equipment that is a discharge gap which is inserted between rails and substation mesh is evaluated.

  2. A heat transfer model of a horizontal ground heat exchanger

    Science.gov (United States)

    Mironov, R. E.; Shtern, Yu. I.; Shtern, M. Yu.; Rogachev, M. S.

    2016-04-01

    Ground-source heat pumps are gaining popularity in Eastern Europe, especially those which are using the horizontal ground heat exchanger (GHX). Due to the difficulty of accessing GHX after the installation, materials and the quality of the installation must satisfy the very high requirements. An inaccurate calculation of GHX can be the reason of a scarcity of heat power in a crucial moment. So far, there isn't any appropriate mathematical description of the horizontal GHX which takes into account the mutual influence of GHX pipes on each other. To solve this problem we used the temperature wave approach. As a result, a mathematical model which describes the dependence of the heat transfer rate per unit length of the horizontal GHX pipe on the thermal properties of soil, operating time of GHX and the distance between pipes was obtained. Using this model, heat transfer rates per unit length of a horizontal GHX were plotted as functions of the distance between pipes and operating time. The modeling shows that heat transfer rates decreases rapidly with the distance between pipes lower then 2 meters. After the launch of heat pump, heat power of GHX is reduced during the first 20 - 30 days and get steady after that. The obtained results correlate with experimental data. Therefore the proposed mathematical model can be used to design a horizontal GHX with the optimal characteristics, and predict its capability during operation.

  3. Geotechnics - the key to ground water protection

    DEFF Research Database (Denmark)

    Baumann, Jens; Foged, Niels; Jørgensen, Peter

    2000-01-01

    During the past 5 to 10 years research into ground water protection has proved that fractures in clay till may increase the hydraulic conductivity and herby the vulnerability of the ground water considerably. However, research has not identified a non-expensive and efficient method to map...

  4. Young Children's Understanding of Cultural Common Ground

    Science.gov (United States)

    Liebal, Kristin; Carpenter, Malinda; Tomasello, Michael

    2013-01-01

    Human social interaction depends on individuals identifying the common ground they have with others, based both on personally shared experiences and on cultural common ground that all members of the group share. We introduced 3- and 5-year-old children to a culturally well-known object and a novel object. An experimenter then entered and asked,…

  5. Grounded Theory as a General Research Methodology

    Directory of Open Access Journals (Sweden)

    Judith A. Holton, Ph.D.

    2008-06-01

    Full Text Available Since its inception over forty years ago, grounded theory has achieved canonical status in the research world (Locke, 2001, p.1. Qualitative researchers, in particular, have embraced grounded theory although often without sufficient scholarship in the methodology (Partington, 2000, p.93; 2002, p.136. The embrace renders many researchers unable to perceive grounded theory as a general methodology and an alternative to the dominant qualitative and quantitative research paradigms. The result is methodological confusion and an often unconscious remodelling of the original methodology (Glaser, 2003. Given the various interpretations and approaches that have been popularised under the rubric of grounded theory, this paper addresses the important distinction between grounded theory as a general methodology and its popularisation as a qualitative research method. The paper begins with a brief overview of grounded theory’s origins and its philosophical foundations then continues by addressing the basic distinction between abstract conceptualisation as employed in classic grounded theory and the conceptual description approach as adopted by many qualitative researchers. The paper continues with a brief overview of the criteria for judging the quality of classic grounded theory and concludes by detailing its methodological principles.

  6. Design of ground segments for small satellites

    Science.gov (United States)

    Mace, Guy

    1994-01-01

    New concepts must be implemented when designing a Ground Segment (GS) for small satellites to conform to their specific mission characteristics: low cost, one main instrument, spacecraft autonomy, optimized mission return, etc. This paper presents the key cost drivers of such ground segments, the main design features, and the comparison of various design options that can meet the user requirements.

  7. Grounded Theory Methodology: Positivism, Hermeneutics, and Pragmatism

    Science.gov (United States)

    Age, Lars-Johan

    2011-01-01

    Glaserian grounded theory methodology, which has been widely adopted as a scientific methodology in recent decades, has been variously characterised as "hermeneutic" and "positivist." This commentary therefore takes a different approach to characterising grounded theory by undertaking a comprehensive analysis of: (a) the philosophical paradigms of…

  8. Ground Truth Annotation in T Analyst

    DEFF Research Database (Denmark)

    2015-01-01

    This video shows how to annotate the ground truth tracks in the thermal videos. The ground truth tracks are produced to be able to compare them to tracks obtained from a Computer Vision tracking approach. The program used for annotation is T-Analyst, which is developed by Aliaksei Laureshyn, Ph...

  9. Ground Motion Prediction Models for Caucasus Region

    Science.gov (United States)

    Jorjiashvili, Nato; Godoladze, Tea; Tvaradze, Nino; Tumanova, Nino

    2016-04-01

    Ground motion prediction models (GMPMs) relate ground motion intensity measures to variables describing earthquake source, path, and site effects. Estimation of expected ground motion is a fundamental earthquake hazard assessment. The most commonly used parameter for attenuation relation is peak ground acceleration or spectral acceleration because this parameter gives useful information for Seismic Hazard Assessment. Since 2003 development of Georgian Digital Seismic Network has started. In this study new GMP models are obtained based on new data from Georgian seismic network and also from neighboring countries. Estimation of models is obtained by classical, statistical way, regression analysis. In this study site ground conditions are additionally considered because the same earthquake recorded at the same distance may cause different damage according to ground conditions. Empirical ground-motion prediction models (GMPMs) require adjustment to make them appropriate for site-specific scenarios. However, the process of making such adjustments remains a challenge. This work presents a holistic framework for the development of a peak ground acceleration (PGA) or spectral acceleration (SA) GMPE that is easily adjustable to different seismological conditions and does not suffer from the practical problems associated with adjustments in the response spectral domain.

  10. Fresnel zones for ground-based antennas

    DEFF Research Database (Denmark)

    Andersen, J. Bach

    1964-01-01

    The ordinary Fresnel zone concept is modified to include the influence of finite ground conductivity. This is important for ground-based antennas because the influence on the radiation pattern of irregularities near the antenna is determined by the amplitude and phase of the groundwave. A new...

  11. Ground Truth Annotation in T Analyst

    DEFF Research Database (Denmark)

    2015-01-01

    This video shows how to annotate the ground truth tracks in the thermal videos. The ground truth tracks are produced to be able to compare them to tracks obtained from a Computer Vision tracking approach. The program used for annotation is T-Analyst, which is developed by Aliaksei Laureshyn, Ph...

  12. Ambulatory Measurement of Ground Reaction Forces

    NARCIS (Netherlands)

    Veltink, Petrus H.; Liedtke, C.B.; Droog, Adriaan

    2004-01-01

    The measurement of ground reaction forces is important in the biomechanical analysis of gait and other motor activities. It is the purpose of this study to show the feasibility of ambulatory measurement of ground reaction forces using two six degrees of freedom sensors mounted under the shoe. One

  13. ECRB ALCOVE AND NICHE GROUND SUPPORT ANALYSIS

    Energy Technology Data Exchange (ETDEWEB)

    J.W. Keifer

    1999-05-09

    The purpose of the analysis is to provide design bases for Enhanced Characterization of the Repository Block (ECRB) alcove and niche ground support drawings. The objective is to evaluate the ESF Alcove Ground Support Analysis (Ref 5.1) to determine if the calculations technically bound the ECRB alcoves and to address specific differences in the conditions and constraints.

  14. Procedures for ground-water investigations

    Energy Technology Data Exchange (ETDEWEB)

    1992-12-01

    This manual was developed by the Pacific Northwest Laboratory (PNL) to document the procedures used to carry out and control the technical aspects of ground-water investigations at the PNL. Ground-water monitoring procedures are developed and used in accordance with the PNL Quality Assurance Program.

  15. Ground-based observations of exoplanet atmospheres

    NARCIS (Netherlands)

    Mooij, Ernst Johan Walter de

    2011-01-01

    This thesis focuses on the properties of exoplanet atmospheres. The results for ground-based near-infrared secondary eclipse observations of three different exoplanets, TrES-3b, HAT-P-1b and WASP-33b, are presented which have been obtained with ground-based telescopes as part of the GROUSE project.

  16. 30 CFR 77.801 - Grounding resistors.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Grounding resistors. 77.801 Section 77.801 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Surface High-Voltage Distribution § 77.801 Grounding...

  17. Ground-based observations of exoplanet atmospheres

    NARCIS (Netherlands)

    Mooij, Ernst Johan Walter de

    2011-01-01

    This thesis focuses on the properties of exoplanet atmospheres. The results for ground-based near-infrared secondary eclipse observations of three different exoplanets, TrES-3b, HAT-P-1b and WASP-33b, are presented which have been obtained with ground-based telescopes as part of the GROUSE project.

  18. Discussing the theological grounds of moral principles.

    Science.gov (United States)

    Heller, Jan C

    2005-01-01

    Discussing the theological beliefs that ground Catholic moral principles can make some people uncomfortable, even while others will appreciate it. But these reactions will sometimes be revealed not as the emotions they are, but as objections to the relative independence or dependence of morality on foundational beliefs. In the end, context should dictate whether one displays the theological beliefs that ground Catholic moral principles.

  19. NO2 DOAS measurements from ground and space: comparison of ground based measurements and OMI data in Mexico City

    Science.gov (United States)

    Rivera, C.; Stremme, W.; Grutter, M.

    2012-04-01

    The combination of satellite data and ground based measurements can provide valuable information about atmospheric chemistry and air quality. In this work we present a comparison between measured ground based NO2 differential columns at the Universidad Nacional Autónoma de México (UNAM) in Mexico City, using the Differential Optical Absorption Spectroscopy (DOAS) technique and NO2 total columns measured by the Ozone Monitoring Instrument (OMI) onboard the Aura satellite using the same measurement technique. From these data, distribution maps of average NO2 above the Mexico basin were constructed and hot spots inside the city could be identified. In addition, a clear footprint was detected from the Tula industrial area, ~50 km northwest of Mexico City, where a refinery, a power plant and other industries are located. A less defined footprint was identified in the Cuernavaca basin, South of Mexico City, and the nearby cities of Toluca and Puebla do not present strong enhancements in the NO2 total columns. With this study we expect to cross-validate space and ground measurements and provide useful information for future studies.

  20. Ground-Wave Propagation Effects on Transmission Lines through Error Images

    Directory of Open Access Journals (Sweden)

    Uribe-Campos Felipe Alejandro

    2014-07-01

    Full Text Available Electromagnetic transient calculation of overhead transmission lines is strongly influenced by the natural resistivity of the ground. This varies from 1-10K (Ω·m depending on several media factors and on the physical composition of the ground. The accuracy on the calculation of a system transient response depends in part in the ground return model, which should consider the line geometry, the electrical resistivity and the frequency dependence of the power source. Up to date, there are only a few reports on the specialized literature about analyzing the effects produced by the presence of an imperfectly conducting ground of transmission lines in a transient state. A broad range analysis of three of the most often used ground-return models for calculating electromagnetic transients of overhead transmission lines is performed in this paper. The behavior of modal propagation in ground is analyzed here into effects of first and second order. Finally, a numerical tool based on relative error images is proposed in this paper as an aid for the analyst engineer to estimate the incurred error by using approximate ground-return models when calculating transients of overhead transmission lines.

  1. An ASIC Low Power Primer Analysis, Techniques and Specification

    CERN Document Server

    Chadha, Rakesh

    2013-01-01

    This book provides an invaluable primer on the techniques utilized in the design of low power digital semiconductor devices.  Readers will benefit from the hands-on approach which starts form the ground-up, explaining with basic examples what power is, how it is measured and how it impacts on the design process of application-specific integrated circuits (ASICs).  The authors use both the Unified Power Format (UPF) and Common Power Format (CPF) to describe in detail the power intent for an ASIC and then guide readers through a variety of architectural and implementation techniques that will help meet the power intent.  From analyzing system power consumption, to techniques that can employed in a low power design, to a detailed description of two alternate standards for capturing the power directives at various phases of the design, this book is filled with information that will give ASIC designers a competitive edge in low-power design. Starts from the ground-up and explains what power is, how it is measur...

  2. The Validity of Divergent Grounded Theory Method

    Directory of Open Access Journals (Sweden)

    Martin Nils Amsteus PhD

    2014-02-01

    Full Text Available The purpose of this article is to assess whether divergence of grounded theory method may be considered valid. A review of literature provides a basis for understanding and evaluating grounded theory. The principles and nature of grounded theory are synthesized along with theoretical and practical implications. It is deduced that for a theory to be truly grounded in empirical data, the method resulting in the theory should be the equivalent of pure induction. Therefore, detailed, specified, stepwise a priori procedures may be seen as unbidden or arbitrary. It is concluded that divergent grounded theory can be considered valid. The author argues that securing methodological transparency through the description of the actual principles and procedures employed, as well as tailoring them to the particular circumstances, is more important than adhering to predetermined stepwise procedures. A theoretical foundation is provided from which diverse theoretical developments and methodological procedures may be developed, judged, and refined based on their own merits.

  3. Optimization of a ground coupled heat pump

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, V.D.; Catan, M.A.

    1984-01-01

    A cooperative analytical project has optimized a horizontal ground coil heat pump system for the Pittsburgh climate. This is the first step in the exploration of several advanced designs including various ground coil devices and advanced heat pump components. The project made use of new and existing design tools to simulate system performance and determine first cost. The system life cycle cost was minimized while constraining the system to meet the design day cooling load using a function minimizing program. Among the system parameters considered were: air-to-refrigerant frontal area, air-to-refrigerant fin pitch, air-to-refrigerant air flowrate, compressor displacement, liquid-to-refrigerant coil length, liquid-to-refrigerant coil diameter, ground coil fluid flowrate, ground coil length, and ground coil depth.

  4. Building Grounded Theory in Entrepreneurship Research

    DEFF Research Database (Denmark)

    Mäkelä, Markus; Turcan, Romeo V.

    2007-01-01

    In this chapter we describe the process of building of theory from data (Glaser and Strauss 1967; Strauss and Corbin 1998). We discuss current grounded theory in relation to research in entrepreneurship and point out directions and potential improvements for further research in this field...... our approach to grounded theory, we acknowledge the existence of other approaches and try to locate our approach in relation to them. As an important part of this discussion, we take a stand on how to usefully define ‘grounded theory’ and ‘case study research’. Second, we seek to firmly link our....... The chapter has two goals. First, we wish to provide an explicit paradigmatic positioning of the grounded theory methodology, discussing the most relevant views of ontology and epistemology that can be used as alternative starting points for conducting grounded theory research. While the chapter introduces...

  5. Building Grounded Theory in Entrepreneurship Research

    DEFF Research Database (Denmark)

    Mäkelä, Markus; Turcan, Romeo V.

    2007-01-01

    our approach to grounded theory, we acknowledge the existence of other approaches and try to locate our approach in relation to them. As an important part of this discussion, we take a stand on how to usefully define ‘grounded theory’ and ‘case study research’. Second, we seek to firmly link our......In this chapter we describe the process of building of theory from data (Glaser and Strauss 1967; Strauss and Corbin 1998). We discuss current grounded theory in relation to research in entrepreneurship and point out directions and potential improvements for further research in this field...... discussion to the potential value of grounded theory research to the field of entrepreneurship and thus the need in this field of further grounded theory....

  6. Discrimination of roast and ground coffee aroma

    Directory of Open Access Journals (Sweden)

    Fisk Ian

    2012-08-01

    Full Text Available Abstract Background Four analytical approaches were used to evaluate the aroma profile at key stages in roast and ground coffee brew preparation (concentration within the roast and ground coffee and respective coffee brew; concentration in the headspace of the roast and ground coffee and respective brew. Each method was evaluated by the analysis of 15 diverse key aroma compounds that were predefined by odour port analysis. Results Different methods offered complimentary results for the discrimination of products; the concentration in the coffee brew was found to be the least discriminatory and concentration in the headspace above the roast and ground coffee was shown to be most discriminatory. Conclusions All approaches should be taken into consideration when classifying roast and ground coffee especially for alignment to sensory perception and consumer insight data as all offer markedly different discrimination abilities due to the variation in volatility, hydrophobicity, air-water partition coefficient and other physicochemical parameters of the key aroma compounds present.

  7. Validation of Sodar Measurements for Wind Power

    DEFF Research Database (Denmark)

    Hansen, Kurt Schaldemose

    2006-01-01

    A ground-based SODAR has been tested for 1½ years together with a traditional measurement set-up consisting of cups and vanes for measuring wind data for wind power assessment at a remote location. Many problems associated to the operation of a remote located SODAR have been solved during...... the project and a new remote power system has been designed. A direct comparison between SODAR and cup measurements revealed a limitation for the SODAR measurements during different weather conditions, especially since the SODAR was not able to measure wind speeds above 15 m/s due to an increasing back......-ground noise. Instead, using the SODAR as a profiler to establish representative wind speed profiles was successful. These wind speed profiles are combined with low height reference measurements to establish reliable hub height wind speed distributions. Representative wind speed profiles can be establish...

  8. Analysis of DC Power Transmission Using High Tc Superconducting Cables

    Institute of Scientific and Technical Information of China (English)

    Jun-Lian Zhang; Jian-Xun Jin

    2008-01-01

    A conceptual superconducting DC cable model is designed and its magnetic fields distribution is analyzed with Ansoft/Maxwell soft. A DC Power transmission system is also studied by using the Matlab/Simulink. With the DC Line and AC Ground Fault, the system losses analysis is introduced.The analysis results mainly include the magnetic fields distribution of the HTS cable model with Ansoft/Maxwell, the system loss, the DC Line and AC Ground Fault with Matlab/Simulation.

  9. Large space systems technology electronics: Data and power distribution

    Science.gov (United States)

    Dunbar, W. G.

    1980-01-01

    The development of hardware technology and manufacturing techniques required to meet space platform and antenna system needs in the 1980s is discussed. Preliminary designs for manned and automatically assembled space power system cables, connectors, and grounding and bonding materials and techniques are reviewed. Connector concepts, grounding design requirements, and bonding requirements are discussed. The problem of particulate debris contamination for large structure spacecraft is addressed.

  10. Dynamic Wireless Power Transfer System For The Unmanned Aerial Vehicles

    OpenAIRE

    Lee, Tae Sup

    2014-01-01

    UAVs have limitless applications to help our daily lives for the autonomous operations. UAVs have a limited power capacity due to weight constraints and are therefore not able to travel long distances. Ground stations for recharging UAVs throughout different points can increase the flight time of the UAVs with the current UAV battery capacity. This study investigates how the wireless charging system for the ground station can be made more robust when there are misalignments. The wireless char...

  11. Metro Grounding Type Design Element Analysis%地铁接地变选型设计要素分析

    Institute of Scientific and Technical Information of China (English)

    赵梦晨

    2015-01-01

    In order to protect the system from tripping in the role of neutral current severe paranoia and other abnormal reactions, the system should set up a large-capacity ground neutral grounding transformer is used. Focuses on the selection of grounding transformer, and the selection includes grounding grounding transformer capacity checking, parallel programs affect the calculation of electric power station, with the system grounding transformer, the impact of flexible power supply scheme for grounding transformers, grounding transformers and so on.%为了防止系统在严重偏执中性电流的作用下出现跳闸等异常反应,系统要设置大容量的接地变压器用作中性点接地。重点研究了接地变压器的选型,而接地变压器的选型主要包括接地容量的验算、站内用电功率的计算、配合系统对接地变压器的影响、柔性供电方案对接地变压器的影响、接地变压器的并列方案等。

  12. 76 FR 5 - Feathering Propeller Systems for Light-Sport Aircraft Powered Gliders

    Science.gov (United States)

    2011-01-03

    ... aircraft, if powered, would be limited to a fixed or ground adjustable propeller.'' We determined that ``a... found in multi-engine aircraft, automatically feather a propeller in the event of a power loss during... manual feathering propeller on an LSA powered glider could impose a hazard to the aircraft...

  13. The Role of Power in Wellness, Oppression, and Liberation: The Promise of Psychopolitical Validity

    Science.gov (United States)

    Prilleltensky, Isaac

    2008-01-01

    The power to promote wellness, resist oppression, and foster liberation is grounded in psychological and political dynamics. Hitherto, these two sources of power have been treated in isolation, both for descriptive and prescriptive purposes. As a result, we lack an integrative theory that explains the role of power in promoting human welfare and…

  14. Modernization of the Cassini Ground System

    Science.gov (United States)

    Razo, Gus; Fujii, Tammy

    2014-01-01

    The Cassini Spacecraft and its ground system have been operational for over 16 years. Modernization presents several challenges due to the personnel, processes, and tools already invested and embedded into the current ground system structure. Every mission's ground system has its own unique complexities and challenges, involving various organizational units. As any mission from its inception to its execution, schedules are always tight. This forces GDS engineers to implement a working ground system that is not necessarily fully optimized. Ground system challenges increase as technology evolves and cyber threats become more sophisticated. Cassini's main challenges were due to its ground system existing before many security requirements were levied on the multi-mission tools and networks. This caused a domino effect on Cassini GDS tools that relied on outdated technological features. In the aerospace industry reliable and established technology is preferred over innovative yet less proven technology. Loss of data for a spacecraft mission can be catastrophic; therefore, there is a reluctance to make changes and updates to the ground system. Nevertheless, all missions and associated teams face the need to modernize their processes and tools. Systems development methods from well-known system analysis and design principles can be applied to many missions' ground systems. Modernization should always be considered, but should be done in such a way that it does not affect flexibility nor interfere with established practices. Cassini has accomplished a secure and efficient ground data system through periodic updates. The obstacles faced while performing the modernization of the Cassini ground system will be outlined, as well as the advantages and challenges that were encountered.

  15. Hanford site ground water protection management plan

    Energy Technology Data Exchange (ETDEWEB)

    1994-10-01

    Ground water protection at the Hanford Site consists of preventative and remedial measures that are implemented in compliance with a variety of environmental regulations at local, state, and federal levels. These measures seek to ensure that the resource can sustain a broad range of beneficial uses. To effectively coordinate and ensure compliance with applicable regulations, the U.S. Department of Energy has issued DOE Order 5400.1 (DOE 1988a). This order requires all U.S. Department of Energy facilities to prepare separate ground water protection program descriptions and plans. This document describes the Ground Water Protection Management Plan (GPMP) for the Hanford Site located in the state of Washington. DOE Order 5400.1 specifies that the GPMP covers the following general topical areas: (1) documentation of the ground water regime; (2) design and implementation of a ground water monitoring program to support resource management and comply with applicable laws and regulations; (3) a management program for ground water protection and remediation; (4) a summary and identification of areas that may be contaminated with hazardous waste; (5) strategies for controlling hazardous waste sources; (6) a remedial action program; and (7) decontamination, decommissioning, and related remedial action requirements. Many of the above elements are currently covered by existing programs at the Hanford Site; thus, one of the primary purposes of this document is to provide a framework for coordination of existing ground water protection activities. The GPMP provides the ground water protection policy and strategies for ground water protection/management at the Hanford Site, as well as an implementation plan to improve coordination of site ground water activities.

  16. Power electronics for low power arcjets

    Science.gov (United States)

    Hamley, John A.; Hill, Gerald M.

    1991-01-01

    In anticipation of the needs of future light-weight low-power spacecraft, arcjet power electronics in the 100- to 400-W operating range were developed. Power topologies similar to those in the higher 2-kW and 5- to 30-kW power range were implemented, including a four-transistor bridge-switching circuit, current-mode pulse-width modulated control, and an output current averaging inductor with an integral pulse generation winding. Reduction of switching transients was accomplished using a low inductance power distribution network, and no passive snubber circuits were necessary for power switch protection. Phase shift control of the power bridge was accomplished using an improved pulse width modulation to phase shift converter circuit. These features, along with conservative magnetics designs, allowed power conversion efficiencies of greater than 92.5 percent to be achieved into resistive loads over the entire operating range of the converter.

  17. Hardware Accelerated Power Estimation

    CERN Document Server

    Coburn, Joel; Raghunathan, Anand

    2011-01-01

    In this paper, we present power emulation, a novel design paradigm that utilizes hardware acceleration for the purpose of fast power estimation. Power emulation is based on the observation that the functions necessary for power estimation (power model evaluation, aggregation, etc.) can be implemented as hardware circuits. Therefore, we can enhance any given design with "power estimation hardware", map it to a prototyping platform, and exercise it with any given test stimuli to obtain power consumption estimates. Our empirical studies with industrial designs reveal that power emulation can achieve significant speedups (10X to 500X) over state-of-the-art commercial register-transfer level (RTL) power estimation tools.

  18. Ground-based gamma-ray telescopes as ground stations in deep-space lasercom

    CERN Document Server

    Carrasco-Casado, Alberto; Vergaz, Ricardo

    2016-01-01

    As the amount of information to be transmitted from deep-space rapidly increases, the radiofrequency technology has become a bottleneck in space communications. RF is already limiting the scientific outcome of deep-space missions and could be a significant obstacle in the developing of manned missions. Lasercom holds the promise to solve this problem, as it will considerably increase the data rate while decreasing the energy, mass and volume of onboard communication systems. In RF deep-space communications, where the received power is the main limitation, the traditional approach to boost the data throughput has been increasing the receiver's aperture, e.g. the 70-m antennas in the NASA's Deep Space Network. Optical communications also can benefit from this strategy, thus 10-m class telescopes have typically been suggested to support future deep-space links. However, the cost of big telescopes increase exponentially with their aperture, and new ideas are needed to optimize this ratio. Here, the use of ground-...

  19. Switching power converters medium and high power

    CERN Document Server

    Neacsu, Dorin O

    2013-01-01

    An examination of all of the multidisciplinary aspects of medium- and high-power converter systems, including basic power electronics, digital control and hardware, sensors, analog preprocessing of signals, protection devices and fault management, and pulse-width-modulation (PWM) algorithms, Switching Power Converters: Medium and High Power, Second Edition discusses the actual use of industrial technology and its related subassemblies and components, covering facets of implementation otherwise overlooked by theoretical textbooks. The updated Second Edition contains many new figures, as well as

  20. Nuclear Power Sources for Space Systems

    Science.gov (United States)

    Kukharkin, N. E.; Ponomarev-Stepnoi, N. N.; Usov, V. A.

    This chapter contains the information about nuclear power sources for space systems. Reactor nuclear sources are considered that use the energy of heavy nuclei fission generated by controlled chain fission reaction, as well as the isotope ones producing heat due to the energy of nuclei radioactive decay. Power of reactor nuclear sources is determined by the rate of heavy nuclei fission that may be controlled within a wide range from the zero up to the nominal one. Thermal power of isotope sources cannot be controlled. It is determined by the type and quantity of isotopes and decreases in time due to their radioactive decay. Both, in the reactor sources and in the isotope ones, nuclear power is converted into the thermal one that may be consumed for the coolant heating to produce thrust (Nuclear Power Propulsion System, NPPS) or may be converted into electricity (Nuclear Power Source, NPS) dynamically (a turbine generator) or statically (thermoelectric or thermionic converters). Electric power is supplied to the airborne equipment or is used to produce thrust in electric (ionic, plasma) low-thrust engines. A brief description is presented of the different nuclear systems with reactor and isotopic power sources implemented in Russia and the USA. The information is also given about isotopic sources for the ground-based application, mainly for navigation systems.