Ground state energies from converging and diverging power series expansions

Energy Technology Data Exchange (ETDEWEB)

Lisowski, C.; Norris, S.; Pelphrey, R.; Stefanovich, E., E-mail: eugene-stefanovich@usa.net; Su, Q.; Grobe, R.

2016-10-15

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.

Evaluation of vibratory ground motion at nuclear power plant sites

International Nuclear Information System (INIS)

Hofmann, R.B.; Greeves, J.T.

1978-01-01

The evaluation of vibratory ground motion at nuclear power plant sites requires the cooperative effort of scientists and engineers in several disciplines. These include seismology, geology, geotechnical engineering and structural engineering. The Geosciences Branch of the NRC Division of Site Safety and Environmental Analysis includes two sections, the Geology/Seismology Section and the Geotechnical Engineering Section

Communication grounding facility

International Nuclear Information System (INIS)

Lee, Gye Seong

1998-06-01

It is about communication grounding facility, which is made up twelve chapters. It includes general grounding with purpose, materials thermal insulating material, construction of grounding, super strength grounding method, grounding facility with grounding way and building of insulating, switched grounding with No. 1A and LCR, grounding facility of transmission line, wireless facility grounding, grounding facility in wireless base station, grounding of power facility, grounding low-tenton interior power wire, communication facility of railroad, install of arrester in apartment and house, install of arrester on introduction and earth conductivity and measurement with introduction and grounding resistance.

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

International Nuclear Information System (INIS)

1976-01-01

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

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 of the p......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...

Applications of power beaming from space-based nuclear power stations. [Laser beaming to airplanes; microwave beaming to ground

Energy Technology Data Exchange (ETDEWEB)

Powell, J.R.; Botts, T.E.; Hertzberg, A.

1981-01-01

Power beaming from space-based reactor systems is examined using an advanced compact, lightweight Rotating Bed Reactor (RBR). Closed Brayton power conversion efficiencies in the range of 30 to 40% can be achieved with turbines, with reactor exit temperatures on the order of 2000/sup 0/K and a liquid drop radiator to reject heat at temperatures of approx. 500/sup 0/K. Higher RBR coolant temperatures (up to approx. 3000/sup 0/K) are possible, but gains in power conversion efficiency are minimal, due to lower expander efficiency (e.g., a MHD generator). Two power beaming applications are examined - laser beaming to airplanes and microwave beaming to fixed ground receivers. Use of the RBR greatly reduces system weight and cost, as compared to solar power sources. Payback times are a few years at present prices for power and airplane fuel.

Space debris removal using a high-power ground-based laser

Energy Technology Data Exchange (ETDEWEB)

Monroe, D.K.

1993-12-31

The feasibility and practicality of using a ground-based laser (GBL) to remove artificial space debris is examined. Physical constraints indicate that a reactor-pumped laser (RPL) may be best suited for this mission, because of its capabilities for multimegawatt output long run-times, and near-diffraction-limited initial beams. Simulations of a laser-powered debris removal system indicate that a 5-MW RPL with a 10-meter-diameter beam director and adaptive optics capabilities can deorbit 1-kg debris from space station altitudes. Larger debris can be deorbited or transferred to safer orbits after multiple laser engagements. A ground-based laser system may be the only realistic way to access and remove some 10,000 separate objects, having velocities in the neighborhood of 7 km/sec, and being spatially distributed over some 10{sup 10} km{sup 3} of space.

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....

Stability evaluation of ground considering dynamic vertical ground motion. Pt. 3. Effect of dynamic vertical motions on sliding safety factor of foundation ground and surrounding slope in nuclear power plant

International Nuclear Information System (INIS)

Ishikawa, Hiroyuki; Sato, Hiroaki; Kawai, Tadashi; Kanatani, Mamoru

2003-01-01

In this report, time differences of the peak accelerations between horizontal and vertical motions were investigated based on the earthquake records on the rock sites and analytical studies were carried out in order to investigate the effect of them to the fluctuations of the minimum sliding safety factors of the foundation ground and surrounding slope of nuclear power plants. Summaries of this report were as follows; (1) Maximum time difference of the peak accelerations between horizontal and vertical motions on the rock sites was approximately 10 seconds in the earthquakes within the epicenter distance of 100 km. (2) Analytical studies that employed the equivalent linear analysis with horizontal and vertical input motions were carried out against the representative models and ground properties of the foundation grounds and surrounding slopes in nuclear power plants. The combinations of the horizontal and vertical motions were determined from the above-mentioned investigation results based on the actual earthquake records. It was revealed that the fluctuations of the minimum sliding safety factors were not seriously affected by the time difference of the peak accelerations between horizontal and vertical motions. (author)

Take-off and Landing Using Ground Based Power - Landing Simulations Using Multibody Dynamics

NARCIS (Netherlands)

Wu, P.; Voskuijl, M.; Van Tooren, M.J.L.

2014-01-01

A novel take-off and landing system using ground based power is proposed in the EUFP7 project GABRIEL. The proposed system has the potential benefit to reduce aircraft weight, emissions and noise. A preliminary investigation of the feasibility of the structural design of the connection mechanism

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

KAUST Repository

Li, Ping; Jiang, Li Jun; Bagci, Hakan

2017-01-01

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

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

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.

A feasible system integrating combined heating and power system with ground-source heat pump

International Nuclear Information System (INIS)

Li, HongQiang; Kang, ShuShuo; Yu, Zhun; Cai, Bo; Zhang, GuoQiang

2014-01-01

A system integrating CHP (combined heating and power) subsystem based on natural gas and GSHP (ground-source heat pump subsystem) in series is proposed. By help of simulation software-Aspen Plus, the energy performance of a typical CHP and GSHP-S (S refers to ‘in series’) system was analyzed. The results show that the system can make a better use of waste heat in flue gas from CHP (combined heating and power subsystem). The total system energy efficiency is 123% and the COP (coefficient of performance) of GSHP (ground-source heat pump) subsystem is 5.3. A referenced CHP and GSHP-P (P refers to ‘in parallel’) system is used for comparison; its total system energy efficiency and COP of GSHP subsystem are 118.6% and 3.5 respectively. Compared with CHP and GSHP-P system with different operating parameters, the CHP and GSHP-S system can increase total system energy efficiency by 0.8–34.7%, with related output ratio of heat to power (R) from 1.9 to 18.3. Furthermore, the COP of GSHP subsystem can be increased between the range 3.6 and 6, which is much higher than that in conventional CHP and GSHP-P system. This study will be helpful for other efficient GSHP systems integrating if there is waste heat or other heat resources with low temperature. - Highlights: • CHP system based on natural gas and ground source heat pump. • The new system can make a better utilization of waste heat in flue gas by a special way. • The proposed system can realize energy saving potential from 0.8 to 34.7%. • The coefficient of performance of ground source heat pump subsystem is significantly improved from 3.5 to 3.6–6. • Warm water temperature and percentage of flue gas used to reheat are key parameters

Thermal power and heat energy of cloud-to-ground lightning process

Energy Technology Data Exchange (ETDEWEB)

Wang, Xuejuan; Yuan, Ping; Xue, Simin [Key Laboratory of Atomic and Molecular Physics and Functional Materials of Gansu Province, College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730070 (China); Cen, Jianyong [School of Physics and Information Engineering, Shanxi Normal University, Linfen 041004 (China)

2016-07-15

A cloud-to-ground lightning flash with nine return strokes has been recorded using a high speed slitless spectrograph and a system composed of a fast antenna and a slow antenna. Based on the spectral data and the synchronous electric field changes that were caused by the lightning, the electrical conductivity, the channel radii, the resistance per unit length, the peak current, the thermal power at the instant of peak current, and the heat energy per unit length during the first 5 μs in the discharge channel have all been calculated. The results indicate that the channel radii have linear relationships with the peak current. The thermal power at the peak current time increases with increasing resistance, but exponential decays with the square of the peak current.

Extremal edges: a powerful cue to depth perception and figure-ground organization.

Science.gov (United States)

Palmer, Stephen E; Ghose, Tandra

2008-01-01

Extremal edges (EEs) are projections of viewpoint-specific horizons of self-occlusion on smooth convex surfaces. An ecological analysis of viewpoint constraints suggests that an EE surface is likely to be closer to the observer than the non-EE surface on the other side of the edge. In two experiments, one using shading gradients and the other using texture gradients, we demonstrated that EEs operate as strong cues to relative depth perception and figure-ground organization. Image regions with an EE along the shared border were overwhelmingly perceived as closer than either flat or equally convex surfaces without an EE along that border. A further demonstration suggests that EEs are more powerful than classical figure-ground cues, including even the joint effects of small size, convexity, and surroundedness.

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.

The ground testing of a 2 kWe solar dynamic space power system

International Nuclear Information System (INIS)

Calogeras, J.E.

1992-01-01

Over the past 25 years Space Solar Dynamic component development has advanced to the point where it is considered a leading candidate power source technology for the evolutionary phases of the Space Station Freedom (SSF) program. Selection of SD power was based on studies and analyses which indicated significant savings in life cycle costs, launch mass and EVA requirements were possible when the system is compared to more conventional photovoltaic/battery power systems. Issues associated with micro-gravity operation such as the behavior of the thermal energy storage materials are being addressed in other programs. This paper reports that a ground test of a 2 kWe solar dynamic system is being planned by the NASA Office of Aeronautics and Space Technology to address the integration issues. The test will be scalable up to 25 kWe, will be flight configured and will incorporate relevant features of the SSF Solar Dynamic Power Module design

Ground noise measurements during static and flyby operations of the Cessna 02-T turbine powered airplane

Science.gov (United States)

Hilton, D. A.; Henderson, H. R.; Lawton, B. W.

1975-01-01

The field noise measurements on the Cessna 02-T turbine powered propeller aircraft are presented. The objective of the study was to obtain the basic noise characteristics of the aircraft during static ground runs and flyover tests, to identify the sources of the noise, and to correlate the noises with the aircraft operating conditions. The results are presented in the form of a overall noise levels, radiation patterns, and frequency spectra. The noise characteristics of the turbine powered aircraft are compared with those of the reciprocating engine powered aircraft.

Perturbations of ionosphere-magnetosphere coupling by powerful VLF emissions from ground-based transmitters

International Nuclear Information System (INIS)

Belov, A. S.; Markov, G. A.; Ryabov, A. O.; Parrot, M.

2012-01-01

The characteristics of the plasma-wave disturbances stimulated in the near-Earth plasma by powerful VLF radiation from ground-based transmitters are investigated. Radio communication VLF transmitters of about 1 MW in power are shown to produce artificial plasma-wave channels (density ducts) in the near-Earth space that originate in the lower ionosphere above the disturbing emission source and extend through the entire ionosphere and magnetosphere of the Earth along the magnetic field lines. Measurements with the onboard equipment of the DEMETER satellite have revealed that under the action of emission from the NWC transmitter, which is one of the most powerful VLF radio transmitters, the generation of quasi-electrostatic (plasma) waves is observed on most of the satellite trajectory along the disturbed magnetic flux tube. This may probably be indicative of stimulated emission of a magnetospheric maser.

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

KAUST Repository

Li, Ping; Jiang, Li Jun; Bagci, Hakan

2016-01-01

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

Response of planted ponderosa pine seedlings to weed control by herbicide in western Montana

Science.gov (United States)

Fabian C.C. Uzoh

1999-01-01

The effects of competing herbaceous vegetation on the growth of ponderosa pine seedlings with and without herbicide Pronone were characterized in this 1987-1990 study. Study areas were established in 36 plantations across western Montana on Champion International Corporation's timberland (currently owned by Plum Creek Timber Company). The study sites were divided...

Assessment of learning powered mobility use--applying grounded theory to occupational performance.

Science.gov (United States)

Nilsson, Lisbeth; Durkin, Josephine

2014-01-01

Collaboration by two grounded theory researchers, who each had developed a learning continuum instrument, led to the emergence of a new tool for assessment of learning powered mobility use. We undertook a rigorous process of comparative reanalysis that included merging, modifying, and expanding our previous research findings. A new instrument together with its facilitating strategies emerged in the course of revisits to our existing rich account of data taken from real environment powered mobility practice over an extensive time period. Instrument descriptors, categories, phases, and stages allow a facilitator to assess actual phase and plot actual occupational performance and provide a learner with the just right challenge through the learning process. Facilitating strategies are described for each of the phases and provide directions for involvement during learner performance. The learning approach is led by a belief system that the intervention is user-led, working in partnership and empowering the learner. The new assessment tool is inclusive of every potential powered mobility user because it focuses on the whole continuum of the learning process of powered mobility use from novice to expert. The new tool was appraised by clinicians and has been used successfully in clinical practice in the United Kingdom and Sweden.

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.

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

Science.gov (United States)

2010-10-01

....376 Section 183.376 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER... propulsion, power, lighting, or distribution system having a neutral bus or conductor must have the neutral... generator to ground before the generator is connected to the bus, except the neutral of an emergency power...

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)

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.

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.

Analysis of payload bay magnetic fields due to dc power multipoint and single point ground configurations

Science.gov (United States)

Lawton, R. M.

1976-01-01

An analysis of magnetic fields in the Orbiter Payload Bay resulting from the present grounding configuration (structure return) was presented and the amount of improvement that would result from installing wire returns for the three dc power buses was determined. Ac and dc magnetic fields at five points in a cross-section of the bay are calculated for both grounding configurations. Y and Z components of the field at each point are derived in terms of a constant coefficient and the current amplitude of each bus. The dc loads assumed are 100 Amperes for each bus. The ac noise current used is a spectrum 6 db higher than the Orbiter equipment limit for narrowband conducted emissions. It was concluded that installing return wiring to provide a single point ground for the dc Buses in the Payload Bay would reduce the ac and dc magnetic field intensity by approximately 30 db.

46 CFR 111.05-13 - Grounding connection.

Science.gov (United States)

2010-10-01

... Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Equipment Ground, Ground Detection, and Grounded Systems § 111.05-13 Grounding... power sources operating in parallel in the system. ...

Movement of radionuclides from river to ground water in vicinity of location for nuclear power plant

International Nuclear Information System (INIS)

Knezevic, Lj.; Lazic, S.; Vukovic, Z.

1984-01-01

The possibility of ground water contamination caused by radionuclide from river water to which liquid effluents were released from a nuclear power station was estimated using one-dimensional transport model. This model is suitable for a homogeneous medium and takes into account hydraulic convection and dispersion as well as physical-chemical retardation for the various radionuclides. (author)

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.

Protection from ground faults in the stator winding of generators at power plants in the Siberian networks

International Nuclear Information System (INIS)

Vainshtein, R. A.; Lapin, V. I.; Naumov, A. M.; Doronin, A. V.; Yudin, S. M.

2010-01-01

The experience of many years of experience in developing and utilization of ground fault protection in the stator winding of generators in the Siberian networks is generalized. The main method of protection is to apply a direct current or an alternating current with a frequency of 25 Hz to the primary circuits of the stator. A direct current is applied to turbo generators operating in a unit with a transformer without a resistive coupling to the external grid or to other generators. Applying a 25 Hz control current is appropriate for power generation systems with compensation of a capacitive short circuit current to ground. This method forms the basis for protection of generators operating on busbars, hydroelectric generators with a neutral grounded through an arc-suppression reactor, including in consolidated units with generators operating in parallel on a single low-voltage transformer winding.

Settlement mechanism of the backfilled ground around nuclear power plant buildings. Part 1. A series of 1G shaking table tests

International Nuclear Information System (INIS)

Ishimaru, Makoto; Kawai, Tadashi

2008-01-01

The large ground settlement locally occurred at the backfilled ground around the Kashiwazaki-Kariwa Nuclear Power Plant buildings during the Niigataken Chuetsu-oki Earthquake in 2007. The purposes of this study are to verify the assumed mechanism of the settlement and to discuss the influence factors on the settlement. For these purposes, we conducted a series of 1G shaking table tests using a rigid structure and sand. In the tests, parameters, which were variously changed, are related to two factors; one is the horizontal ground displacement relative to the structure, the other is the ground strength against the sliding failure. The following results were obtained: (1) All the results showed that the ground settlement sizes near the structure were larger than the ground settlement sizes far from the structure, (2) From the video observed at the ground near the structure, it was found that the settlement locally occurred due to the sliding failure after the ground was separated from the structure, (3) The ground settlement sizes near the structure were large as the horizontal ground displacement sizes were large, and the soil strength arising from fines affected the ground settlement sizes near the structure. (author)

The power of ground user in recommender systems.

Directory of Open Access Journals (Sweden)

Yanbo Zhou

Full Text Available Accuracy and diversity are two important aspects to evaluate the performance of recommender systems. Two diffusion-based methods were proposed respectively inspired by the mass diffusion (MD and heat conduction (HC processes on networks. It has been pointed out that MD has high recommendation accuracy yet low diversity, while HC succeeds in seeking out novel or niche items but with relatively low accuracy. The accuracy-diversity dilemma is a long-term challenge in recommender systems. To solve this problem, we introduced a background temperature by adding a ground user who connects to all the items in the user-item bipartite network. Performing the HC algorithm on the network with ground user (GHC, it showed that the accuracy can be largely improved while keeping the diversity. Furthermore, we proposed a weighted form of the ground user (WGHC by assigning some weights to the newly added links between the ground user and the items. By turning the weight as a free parameter, an optimal value subject to the highest accuracy is obtained. Experimental results on three benchmark data sets showed that the WGHC outperforms the state-of-the-art method MD for both accuracy and diversity.

The power of ground user in recommender systems.

Science.gov (United States)

Zhou, Yanbo; Lü, Linyuan; Liu, Weiping; Zhang, Jianlin

2013-01-01

Accuracy and diversity are two important aspects to evaluate the performance of recommender systems. Two diffusion-based methods were proposed respectively inspired by the mass diffusion (MD) and heat conduction (HC) processes on networks. It has been pointed out that MD has high recommendation accuracy yet low diversity, while HC succeeds in seeking out novel or niche items but with relatively low accuracy. The accuracy-diversity dilemma is a long-term challenge in recommender systems. To solve this problem, we introduced a background temperature by adding a ground user who connects to all the items in the user-item bipartite network. Performing the HC algorithm on the network with ground user (GHC), it showed that the accuracy can be largely improved while keeping the diversity. Furthermore, we proposed a weighted form of the ground user (WGHC) by assigning some weights to the newly added links between the ground user and the items. By turning the weight as a free parameter, an optimal value subject to the highest accuracy is obtained. Experimental results on three benchmark data sets showed that the WGHC outperforms the state-of-the-art method MD for both accuracy and diversity.

Effects of velocity and weight support on ground reaction forces and metabolic power during running.

Science.gov (United States)

Grabowski, Alena M; Kram, Rodger

2008-08-01

The biomechanical and metabolic demands of human running are distinctly affected by velocity and body weight. As runners increase velocity, ground reaction forces (GRF) increase, which may increase the risk of an overuse injury, and more metabolic power is required to produce greater rates of muscular force generation. Running with weight support attenuates GRFs, but demands less metabolic power than normal weight running. We used a recently developed device (G-trainer) that uses positive air pressure around the lower body to support body weight during treadmill running. Our scientific goal was to quantify the separate and combined effects of running velocity and weight support on GRFs and metabolic power. After obtaining this basic data set, we identified velocity and weight support combinations that resulted in different peak GRFs, yet demanded the same metabolic power. Ideal combinations of velocity and weight could potentially reduce biomechanical risks by attenuating peak GRFs while maintaining aerobic and neuromuscular benefits. Indeed, we found many combinations that decreased peak vertical GRFs yet demanded the same metabolic power as running slower at normal weight. This approach of manipulating velocity and weight during running may prove effective as a training and/or rehabilitation strategy.

Research of grounding capacitive current of neutral non-grounding auxiliary system in nuclear power plants

International Nuclear Information System (INIS)

Yang Shan; Liu Li; Huang Xiaojing

2014-01-01

In the domestic and abroad standards, the grounding capacitive current limitation in the non-grounding electric auxiliary system is less than 10 A. Limiting capacitive current in the standard aims to speed up the arc extinguishing to reduce the duration of arc over-voltage, but not to prevent the arc producing, The arc over-voltage harm is related to the multiple, frequency and duration of the over-voltage. When the insulation vulnerabilities appear in the equipment, the arc over-voltage may result in insulation vulnerabilities of the electrical equipment breakdown, which leads to multiple, short-circuit accidents. The cable connector, accessory and electromotor winding are all insulation vulnerabilities. Setting the arc suppression coil which can counteract the grounding capacitive current makes the arc vanish quickly. Using the casting bus which remarkably reduces the ground capacitance of the electric transmission line makes the equipment safer. (authors)

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.

Kosovo’s Ground Flash Density and Protection of Transmission Lines of the Kosovo Power System from Atmospheric Discharges

Directory of Open Access Journals (Sweden)

Bahri Prebreza

2018-03-01

Full Text Available In this paper is presented the protection of transmission power lines of the Kosovo Power System from atmospheric discharges, with the use of surge arresters. Atmospheric discharges represent one of the main causes of interruptions for the Kosovo Power System. In addition, the ground flash density for Kosovo is given. The transmission lines with the worst performance regarding atmospheric discharges are discussed in more detail and are presented recommendations about the surge arresters used to protect the system from these overvoltages. The data provided by the localized lightning system in Kosovo enable us to provide a detailed correlation of the reported outages of the Kosovo Power System and corresponding atmospheric discharges. Recommendations for protection in terms of surge arresters are given followed by subsequent dynamic simulations using MATLAB software.

Ground Shock Resistant of Buried Nuclear Power Plant Facility

International Nuclear Information System (INIS)

Ornai, D.; Adar, A.; Gal, E.

2014-01-01

Nuclear Power Plant (NPP) might be subjected to hostile attacks such as Earth Penetrating Weapons (EPW) that carry explosive charges. Explosions of these weapons near buried NPP facility might cause collapse, breaching, spalling, deflection, shear, rigid body motion (depending upon the foundations), and in-structure shock. The occupants and the equipment in the buried facilities are exposed to the in-structure motions, and if they are greater than their fragility values than occupants might be wounded or killed and the equipment might be damaged, unless protective measures will be applied. NPP critical equipment such as pumps are vital for the normal safe operation since it requires constant water circulation between the nuclear reactor and the cooling system, including in case of an immediate shut down. This paper presents analytical- semi empirical formulation and analysis of the explosion of a penetrating weapon with a warhead of 100kgs TNT (Trinitrotoluene) that creates ground shock effect on underground NPP structure containing equipment, such as a typical pump. If the in-structure spectral shock is greater than the pump fragility values than protective measures are required, otherwise a real danger to the NPP safety might occur

Characteristics of near-field earthquake ground motion

International Nuclear Information System (INIS)

Kim, H. K.; Choi, I. G.; Jeon, Y. S.; Seo, J. M.

2002-01-01

The near-field ground motions exhibit special response characteristics that are different from those of ordinary ground motions in the velocity and displacement response. This study first examines the characteristics of near-field ground motion depending on fault directivity and fault normal and parallel component. And the response spectra of the near field ground motion are statistically processed, and are compared with the Regulatory Guide 1.60 spectrum that is present design spectrum of the nuclear power plant. The response spectrum of the near filed ground motions shows large spectral velocity and displacement in the low frequency range. The spectral accelerations of near field ground motion are greatly amplified in the high frequency range for the rock site motions, and in the low frequency range for the soil site motions. As a result, the near field ground motion effects should be considered in the seismic design and seismic safety evaluation of the nuclear power plant structures and equipment

Lightning and surge protection of large ground facilities

Science.gov (United States)

Stringfellow, Michael F.

1988-04-01

The vulnerability of large ground facilities to direct lightning strikes and to lightning-induced overvoltages on the power distribution, telephone and data communication lines are discussed. Advanced electrogeometric modeling is used for the calculation of direct strikes to overhead power lines, buildings, vehicles and objects within the facility. Possible modes of damage, injury and loss are discussed. Some appropriate protection methods for overhead power lines, structures, vehicles and aircraft are suggested. Methods to mitigate the effects of transients on overhead and underground power systems as well as within buildings and other structures are recommended. The specification and location of low-voltage surge suppressors for the protection of vulnerable hardware such as computers, telecommunication equipment and radar installations are considered. The advantages and disadvantages of commonly used grounding techniques, such as single point, multiple and isolated grounds are compared. An example is given of the expected distribution of lightning flashes to a large airport, its buildings, structures and facilities, as well as to vehicles on the ground.

Method for analysis the complex grounding cables system

International Nuclear Information System (INIS)

Ackovski, R.; Acevski, N.

2002-01-01

A new iterative method for the analysis of the performances of the complex grounding systems (GS) in underground cable power networks with coated and/or uncoated metal sheathed cables is proposed in this paper. The analyzed grounding system consists of the grounding grid of a high voltage (HV) supplying transformer station (TS), middle voltage/low voltage (MV/LV) consumer TSs and arbitrary number of power cables, connecting them. The derived method takes into consideration the drops of voltage in the cable sheets and the mutual influence among all earthing electrodes, due to the resistive coupling through the soil. By means of the presented method it is possible to calculate the main grounding system performances, such as earth electrode potentials under short circuit fault to ground conditions, earth fault current distribution in the whole complex grounding system, step and touch voltages in the nearness of the earthing electrodes dissipating the fault current in the earth, impedances (resistances) to ground of all possible fault locations, apparent shield impedances to ground of all power cables, e.t.c. The proposed method is based on the admittance summation method [1] and is appropriately extended, so that it takes into account resistive coupling between the elements that the GS. (Author)

Discontinuous Galerkin time-domain analysis of power/ground plate pairs with wave port excitation

KAUST Repository

Li, Ping; Jiang, Li Jun; Bagci, Hakan

2018-01-01

In this work, a discontinuous Galerkin time-domain method is developed to analyze the power/ground plate pairs taking into account arbitrarily shaped antipads. To implement proper source excitations over the antipads, the magnetic surface current expanded by the electric eigen-modes supported by the corresponding antipad is employed as the excitation. For irregularly shaped antipads, the eigen-modes are obtained by numerical approach. Accordingly, the methodology for the S-parameter extraction is derived based on the orthogonal properties of the different modes. Based on the approach, the transformation between different modes can be readily evaluated.

Discontinuous Galerkin time-domain analysis of power/ground plate pairs with wave port excitation

KAUST Repository

Li, Ping

2018-04-06

In this work, a discontinuous Galerkin time-domain method is developed to analyze the power/ground plate pairs taking into account arbitrarily shaped antipads. To implement proper source excitations over the antipads, the magnetic surface current expanded by the electric eigen-modes supported by the corresponding antipad is employed as the excitation. For irregularly shaped antipads, the eigen-modes are obtained by numerical approach. Accordingly, the methodology for the S-parameter extraction is derived based on the orthogonal properties of the different modes. Based on the approach, the transformation between different modes can be readily evaluated.

ANALISIS PENGARUH REKONFIGURASI GROUNDING KABEL POWER 20 kV TERHADAP ERROR RATIO CURRENT TRANSFORMERS PELANGGAN TEGANGAN MENENGAH DI HOTEL GOLDEN TULIP SEMINYAK

Directory of Open Access Journals (Sweden)

Kadek Amerta Yasa

2017-10-01

Full Text Available Hotel Golden Tulip Seminyak  merupakan pelanggan listrik tegangan menengah yang sangat potensial. Pada penelitian di hotel ini,  kami menemukan bahwa error ratio trafo arus sebelum rekonfigurasi grounding berkisar – 67% dan rugi-rugi daya sebesar - 214.809,00 W pada persentase beban 20%.  Error ratio memengaruhi arus yang terbaca di sisi sekunder trafo dan juga memengaruhi rugi daya.  Upaya yang dilakukan untuk mengurangi nilai error ratio dan rugi daya tersebut yaitu dengan melakukan rekonfigurasi grounding yaitu dengan memindahkan posisi tap grounding kabel power 20 kV masuk kembali melalui sisi primer trafo arus.  Nilai error ratio setelah rekonfigurasi grounding diperoleh berkisar – 0,05% dan  rugi-rugi daya - 20,18 W pada persentase beban 20%.

49 CFR 234.213 - Grounds.

Science.gov (United States)

2010-10-01

... Maintenance Standards § 234.213 Grounds. Each circuit that affects the proper functioning of a highway-rail... in the circuit. This requirement does not apply to: circuits that include track rail; alternating current power distribution circuits that are grounded in the interest of safety; and common return wires...

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

, with the advantage that the warmed water can be reused in a thermal power plant or at regional heating, thus, minimising the overall losses. However, one problem was raised by those purchasing the boilers, mainly the possibility of an unwanted triggering of the protections relays, especially ground fault protection...... for the testing of two ground fault protection relays, in order to assure that they are not triggered by the energisation of the boiler. The test is performed via an OMICRON CMC 256 with Advanced TransPlay SW, which generates the signals that would be present at the secondary of the instrumentation transformers......, 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...

Deflection of electron beams by ground planes

International Nuclear Information System (INIS)

Fernsler, R.F.; Lampe, M.

1991-01-01

Analytic methods are used to determine the effect of a nearby ground plane on the trajectory of a relativistic electron beam passing through dense gas. The beam is shown to respond to the ground plane in one of two distinct modes, determined by beam current and energy. Low-power beams deflect from the ground plane and tear longitudinally. High-power beams do not deflect or tear but tilt, i.e., the beam axis is no longer parallel to the direction of propagation. This conclusion is reached by computing the net beam force as a superposition of the ''bare'' ground-plane forces, the shielding forces from the beam-generated plasma, the body coupling forces induced by beam tilt, and the force that arises as the beam separates from the plasma. Effects from electromagnetic retardation and ground resistivity are shown to be negligible in typical cases of interest, and the interaction between ground planes and other external forces is discussed as well

Tornado damage at the Grand Gulf, Mississippi nuclear power plant site: aerial and ground surveys

International Nuclear Information System (INIS)

Fujita, T.T.; McDonald, J.R.

1978-05-01

A tornado struck the Grand Gulf nuclear power generating station, Port Gibson, Mississippi, about 11:30 p.m. on April 17, 1978. Storm damage investigators from the University of Chicago and Texas Tech University were dispatched to survey the damage. The meteorological situation that spawned the Grand Gulf tornado and seven others in the area is discussed. Aerial surveys of the entire damage path and detailed surveys of the plant site are presented. An engineering evaluation of the damage is also presented based primarily on information gained from detailed ground surveys

30 CFR 75.811 - High-voltage underground equipment; grounding.

Science.gov (United States)

2010-07-01

...-voltage equipment supplying power to such equipment receiving power from resistance grounded systems shall... 30 Mineral Resources 1 2010-07-01 2010-07-01 false High-voltage underground equipment; grounding... COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Underground High-Voltage...

Coupling analysis on the soft ground settlement laws in Qinshan nuclear power phase I sea wall project

International Nuclear Information System (INIS)

Sun Feng; Pan Rong; Zhu Xiuyun; Zhang Dingli

2011-01-01

Qinshan Nuclear Power Phase I sea wall project is a barrier engineering in defending the design basis flooding, which is of importance to the safety of NPP. The geological condition has the feature of high compressibility and low penetration, such as the soft ground of 1 + 450 section of Qinshan Nuclear Power Phase I sea wall. Based on parameters acquired from the site experiment, 3-D finite difference analysis is put forward to study the feature of consolidation settlement laws, which can embody the fluid-solid coupling interaction. The conclusions of numerical analysis agree well with the in-site measured data, and it, can contribute to the design and construction of raising sea wall project. (authors)

Grounding for safety

Energy Technology Data Exchange (ETDEWEB)

Prud' homme, P. [Hydro-Quebec, Montreal, PQ (Canada). TransEnergie Div.

2006-07-01

The importance of providing electrical grounds as a safety issue in the design of power transmission lines was discussed. Power transmission lines extend over several thousands of kilometers crossing various environments, including communities where electric utilities encourage the use of transmission rights-of-way passages for uses such as bicycle paths. In recent years, many new residential communities have been built at the border of power transmission rights-of-ways or substations. In view of this emerging trend, and the fact that internal statistics indicate that lightning strikes are responsible of about 50 to 60 per cent of transmission line faults, electric utilities are obligated to verify if their installations are safe. Hydro-Quebec TransEnergie's view on this subject was presented along with a review of international standards to determine if limits for touch voltage, step voltage and transferred potential close to transmission lines have been established by the international community. A variety of mitigation measures to control the increase in ground potential in the event of electrical faults were also proposed. tabs., figs.

Enhanced ground bounce noise reduction in a low-leakage CMOS multiplier

Science.gov (United States)

Verma, Bipin Kumar; Akashe, Shyam; Sharma, Sanjay

2015-09-01

In this paper, various parameters are used to reduce leakage power, leakage current and noise margin of circuits to enhance their performance. A multiplier is proposed with low-leakage current and low ground bounce noise for the microprocessor, digital signal processors (DSP) and graphics engines. The ground bounce noise problem appears when a conventional power-gating circuit transits from sleep-to-active mode. This paper discusses a reduction in leakage current in the stacking power-gating technique by three modes - sleep, active and sleep-to-active. The simulation results are performed on a 4 × 4 carry-save multiplier for leakage current, active power, leakage power and ground bounce noise, and comparison made for different nanoscales. Ground bounce noise is limited to 90%. The leakage current of the circuit is decimated up to 80% and the active power is reduced to 31%. We performed simulations using cadence virtuoso 180 and 45 nm at room temperature at various supply voltages.

Assessment of erecting nuclear power plants below ground in an open building pit

International Nuclear Information System (INIS)

Kroeger, W.; Altes, J.; Bongartz, R.; David, P.H.; Escherich, K.H.; Kasper, K.; Koschmieder, D.; Roethig, K.D.; Schwarzer, K.; Wolters, J.

1978-01-01

The technical feasibility, costs and safety potential of siting a nuclear power plant below ground level have been assessed. The reference plant was a 1,300 MWsub(e) PWR and the siting was based on a 'cut-and-cover' design in soil. The 'cut-and-cover' design enhances the safety potential of the site both with regard to extreme internal accidents and to external impacts inclusive of hostile attack. The measures required to 'harden' the site against these extreme conditions do not cancel each other. The realization of the safety potential is strongly dependent on the reliability of the closure equipment on routes to the atmosphere. These closures represent the remaining vulnerable feature of the design, as all other release paths are through soil which prevents any immediate danger to the public. The concepts considered include partial or complete lowering of the reactor. The thickness of the coverage depends on the degree of protection required and is typically between 8 and 13 m. The essential systems of the above-ground design are unchanged and therefore prior experience and existing designs can be applied. The concepts appear to be technically feasible including, in particular, the large pits and the additional closures; the technical difficulties, however, should not be underestimated. The depth of lowering does not determine the gain in safety because a well designed coverage can act as natural soil. Partial lowering, in fact, appears to be the more economic method. According to the degree of protection and the variations of design, the concepts would cost between 8 and 14% more than the capital cost of an equivalent above-ground plant. The construction time would be extended by 1.4 years for the concepts investigated. (orig./HP) [de

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.

Grounding modelling for transient overvoltage simulation in electric power transmission

International Nuclear Information System (INIS)

Moreno O, German; Valencia V, Jaime A; Villada, Fernando

1992-01-01

Grounding plays an important role in transmission line outages and consequently on electric energy transmission quality indexes. Fundamentals of an accurate modelling for transient behaviour analysis, particularly for the response of transmission lines to lightning, are presented. Also, a method to take into account the electromagnetic propagation guided by the grounding electrodes and finally to assess the grounding impedance in order to simulate the transmission line behaviour under lightning is presented. Analysis of impedance behaviour for diverse configurations and simulation results of over voltages on a real 220 kV line are presented to illustrate the capabilities of the method and of the computational program developed

Artificial ground motion compatible with specified peak ground displacement and target multi-damping response spectra

International Nuclear Information System (INIS)

Zhang Yushan; Zhao Fengxin

2010-01-01

With respect to the design ground motion of nuclear power plant (NPP), the Regular Guide 1.60 of the US not only defined the standard multi-damping response spectra, i.e. the RG1.60 spectra, but also definitely prescribed the peak ground displacement (PGD) value corresponding to the standard spectra. However, in the engineering practice of generating multi-damping-spectra-compatible artificial ground motion for the seismic design of NPP, the PGD value had been neglected. Addressing this issue, this paper proposed a synthesizing method which generates the artificial ground motion compatible with not only the target multi-damping response spectra but also the specified PGD value. Firstly, by the transfer formula between the power spectrum and the response spectrum, an initial uniformly modulated acceleration time history is synthesized by multiplying the stationary Gaussian process with the prescribed intensity envelope to simulate the amplitude-non-stationarity of earthquake ground motion. And then by superimposing a series of narrow-band time histories in the time domain, the initial time history is modified in the iterative manner to match the target PGD as well as the target multi-damping spectra with the pre-specified matching precisions. Numerical examples are provided to demonstrate the matching precisions of the proposed method to the target values.

Mitigating Space Weather Impacts on the Power Grid in Real-Time: Applying 3-D EarthScope Magnetotelluric Data to Forecasting Reactive Power Loss in Power Transformers

Science.gov (United States)

Schultz, A.; Bonner, L. R., IV

2017-12-01

Current efforts to assess risk to the power grid from geomagnetic disturbances (GMDs) that result in geomagnetically induced currents (GICs) seek to identify potential "hotspots," based on statistical models of GMD storm scenarios and power distribution grounding models that assume that the electrical conductivity of the Earth's crust and mantle varies only with depth. The NSF-supported EarthScope Magnetotelluric (MT) Program operated by Oregon State University has mapped 3-D ground electrical conductivity structure across more than half of the continental US. MT data, the naturally occurring time variations in the Earth's vector electric and magnetic fields at ground level, are used to determine the MT impedance tensor for each site (the ratio of horizontal vector electric and magnetic fields at ground level expressed as a complex-valued frequency domain quantity). The impedance provides information on the 3-D electrical conductivity structure of the Earth's crust and mantle. We demonstrate that use of 3-D ground conductivity information significantly improves the fidelity of GIC predictions over existing 1-D approaches. We project real-time magnetic field data streams from US Geological Survey magnetic observatories into a set of linear filters that employ the impedance data and that generate estimates of ground level electric fields at the locations of MT stations. The resulting ground electric fields are projected to and integrated along the path of power transmission lines. This serves as inputs to power flow models that represent the power transmission grid, yielding a time-varying set of quasi-real-time estimates of reactive power loss at the power transformers that are critical infrastructure for power distribution. We demonstrate that peak reactive power loss and hence peak risk for transformer damage from GICs does not necessarily occur during peak GMD storm times, but rather depends on the time-evolution of the polarization of the GMD's inducing fields

Ground motion prediction needs for nuclear engineering design

International Nuclear Information System (INIS)

Hadjian, A.H.

1985-01-01

The basic design philosophy of nuclear power plants stipulates that the risk to the public be as low as reasonably achievable. As a result of this philosophy, the seismic design of nuclear power plants has tended, over time, to diverge from that of other engineered structures. The emphasis at the present time is to specify ground motion at a nuclear facility site as realistically as possible and to design all safety-related structures to respond to the specified ground motion in the elastic range. The characteristics of this realistic design ground motion are discussed and present prediction needs identified

Ground testing of an SP-100 prototypic reactor

International Nuclear Information System (INIS)

Motwani, K.; Pflasterer, G.R.; Upton, H.; Lazarus, J.D.; Gluck, R.

1988-01-01

SP-100 is a space power system which is being developed by GE to meet future space electrical power requirements. The ground testing of an SP-100 prototypic reactor system will be conducted at the Westinghouse Hanford Company site located at Richland, Washington. The objective of this test is to demonstrate the performance of a full scale prototypic reactor system, including the reactor, control system and flight shield. The ground test system is designed to simulate the flight operating conditions while meeting all the necessary nuclear safety requirements in a gravity environment. The goal of the reactor ground test system is to establish confidence in the design maturity of the SP-100 space reactor power system and resolve the technical issues necessary for the development of a flight mission design

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...

Decrease in Ground-Run Distance of Small Airplanes by Applying Electrically-Driven Wheels

Science.gov (United States)

Kobayashi, Hiroshi; Nishizawa, Akira

A new takeoff method for small airplanes was proposed. Ground-roll performance of an airplane driven by electrically-powered wheels was experimentally and computationally studied. The experiments verified that the ground-run distance was decreased by half with a combination of the powered driven wheels and propeller without increase of energy consumption during the ground-roll. The computational analysis showed the ground-run distance of the wheel-driven aircraft was independent of the motor power when the motor capability exceeded the friction between tires and ground. Furthermore, the distance was minimized when the angle of attack was set to the value so that the wing generated negative lift.

TARDEC Overview: Ground Vehicle Power and Mobility

Science.gov (United States)

2011-02-04

Fuel & Water Distribution • Force Sustainment • Construction Equipment • Bridging • Assured Mobility Systems Robotics • TALON • PackBot • MARCbot...Equipment • Mechanical Countermine Equipment • Tactical Bridging Intelligent Ground Systems • Autonomous Robotics Systems • Safe Operations...Test Cell • Hybrid Electric Reconfigurable Moveable Integration Testbed (HERMIT) • Electro-chemical Analysis and Research Lab (EARL) • Battery Lab • Air

Innovative Approaches to Development and Ground Testing of Advanced Bimodal Space Power and Propulsion Systems

International Nuclear Information System (INIS)

Hill, T.; Noble, C.; Martinell, J.; Borowski, S.

2000-01-01

The last major development effort for nuclear power and propulsion systems ended in 1993. Currently, there is not an initiative at either the National Aeronautical and Space Administration (NASA) or the U.S. Department of Energy (DOE) that requires the development of new nuclear power and propulsion systems. Studies continue to show nuclear technology as a strong technical candidate to lead the way toward human exploration of adjacent planets or provide power for deep space missions, particularly a 15,000 lbf bimodal nuclear system with 115 kW power capability. The development of nuclear technology for space applications would require technology development in some areas and a major flight qualification program. The last major ground test facility considered for nuclear propulsion qualification was the U.S. Air Force/DOE Space Nuclear Thermal Propulsion Project. Seven years have passed since that effort, and the questions remain the same, how to qualify nuclear power and propulsion systems for future space flight. It can be reasonably assumed that much of the nuclear testing required to qualify a nuclear system for space application will be performed at DOE facilities as demonstrated by the Nuclear Rocket Engine Reactor Experiment (NERVA) and Space Nuclear Thermal Propulsion (SNTP) programs. The nuclear infrastructure to support testing in this country is aging and getting smaller, though facilities still exist to support many of the technology development needs. By renewing efforts, an innovative approach to qualifying these systems through the use of existing facilities either in the U.S. (DOE's Advance Test Reactor, High Flux Irradiation Facility and the Contained Test Facility) or overseas should be possible

Innovation Approaches to Development and Ground Testing of Advanced Bimodal Space Power and Propulsion Systems

Energy Technology Data Exchange (ETDEWEB)

Hill, T.; Noble, C.; Martinell, J. (INEEL); Borowski, S. (NASA Glenn Research Center)

2000-07-14

The last major development effort for nuclear power and propulsion systems ended in 1993. Currently, there is not an initiative at either the National Aeronautical and Space Administration (NASA) or the U.S. Department of Energy (DOE) that requires the development of new nuclear power and propulsion systems. Studies continue to show nuclear technology as a strong technical candidate to lead the way toward human exploration of adjacent planets or provide power for deep space missions, particularly a 15,000 lbf bimodal nuclear system with 115 kW power capability. The development of nuclear technology for space applications would require technology development in some areas and a major flight qualification program. The last major ground test facility considered for nuclear propulsion qualification was the U.S. Air Force/DOE Space Nuclear Thermal Propulsion Project. Seven years have passed since that effort, and the questions remain the same, how to qualify nuclear power and propulsion systems for future space flight. It can be reasonably assumed that much of the nuclear testing required to qualify a nuclear system for space application will be performed at DOE facilities as demonstrated by the Nuclear Rocket Engine Reactor Experiment (NERVA) and Space Nuclear Thermal Propulsion (SNTP) programs. The nuclear infrastructure to support testing in this country is aging and getting smaller, though facilities still exist to support many of the technology development needs. By renewing efforts, an innovative approach to qualifying these systems through the use of existing facilities either in the U.S. (DOE's Advance Test Reactor, High Flux Irradiation Facility and the Contained Test Facility) or overseas should be possible.

Innovative Approaches to Development and Ground Testing of Advanced Bimodal Space Power and Propulsion Systems

Energy Technology Data Exchange (ETDEWEB)

Hill, Thomas Johnathan; Noble, Cheryl Ann; Noble, C.; Martinell, John Stephen; Borowski, S.

2000-07-01

The last major development effort for nuclear power and propulsion systems ended in 1993. Currently, there is not an initiative at either the National Aeronautical and Space Administration (NASA) or the U.S. Department of Energy (DOE) that requires the development of new nuclear power and propulsion systems. Studies continue to show nuclear technology as a strong technical candidate to lead the way toward human exploration of adjacent planets or provide power for deep space missions, particularly a 15,000 lbf bimodal nuclear system with 115 kW power capability. The development of nuclear technology for space applications would require technology development in some areas and a major flight qualification program. The last major ground test facility considered for nuclear propulsion qualification was the U.S. Air Force/DOE Space Nuclear Thermal Propulsion Project. Seven years have passed since that effort, and the questions remain the same, how to qualify nuclear power and propulsion systems for future space flight. It can be reasonable assumed that much of the nuclear testing required to qualify a nuclear system for space application will be performed at DOE facilities as demonstrated by the Nuclear Rocket Engine Reactor Experiment (NERVA) and Space Nuclear Thermal Propulsion (SNTP) programs. The nuclear infrastructure to support testing in this country is aging and getting smaller, though facilities still exist to support many of the technology development needs. By renewing efforts, an innovative approach to qualifying these systems through the use of existing facilities either in the U.S. (DOE's Advance Test Reactor, High Flux Irradiation Facility and the Contained Test Facility) or overseas should be possible.

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 (SPS) concept in geostationary Earth orbit to a concentrating solar power (CSP) 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 SPS concept has a higher end-to-end efficiency, the combined space and ground collector infrastructure is still about the same size as a comparable CSP system on the ground.

18 CFR 430.19 - Ground water withdrawal metering, recording, and reporting.

Science.gov (United States)

2010-04-01

... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Ground water withdrawal metering, recording, and reporting. 430.19 Section 430.19 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION SPECIAL REGULATIONS GROUND WATER PROTECTION AREA: PENNSYLVANIA § 430.19...

Navigating Grounded Theory:A critical and reflective response to the challenges of using grounded theory in an education PhD

OpenAIRE

Nelson, James

2015-01-01

This paper offers a critical reflection upon the use of a grounded theory approach within a doctoral study. As well as providing an outline of grounded theory, it begins by noting the existence of some powerful critiques of a grounded theory approach, in particular around the key concepts of ‘theory’, ‘discovery’ and ‘ground’. It is argued that, in some cases, grounded theory struggles to counter these challenges, especially in its ‘purist’ forms. However, with reference to research carried o...

49 CFR 236.2 - Grounds.

Science.gov (United States)

2010-10-01

... circuit, except circuits which include any track rail and except the common return wires of single-wire, single-break, signal control circuits using a grounded common, and alternating current power distribution...

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.

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...

Current status of ground motions evaluation in seismic design guide for nuclear power facilities. Investigation on IAEA and US.NRC

International Nuclear Information System (INIS)

Nakajima, Masato; Ito, Hiroshi; Hirata, Kazuta

2009-01-01

Recently, IAEA (International Atomic Energy Agency) and US.NRC (US. Nuclear Regulatory Commission) published several standards and technical reports on seismic design and safety evaluation for nuclear power facilities. This report summarizes the current status of the international guidelines on seismic design and safety evaluation for nuclear power facilities in order to explore the future research topics. The main results obtained are as follows: 1 IAEA: (1) In the safety standard series, two levels are defined as seismic design levels, and design earthquake ground motion is determined corresponding to each seismic design level. (2) A new framework on seismic design which consists of conventional deterministic method and risk-based method is discussed in the technical report although the framework is not adopted in the safety guidelines. 2 USA: (1) US.NRC discusses a performance-based seismic design framework which has been originally developed by the private organization (American Society of Civil Engineers). (2) Design earthquakes and earthquake ground motion are mainly evaluated and determined based on probabilistic seismic hazard evaluations. 3 Future works: It should be emphasized that IAEA and US.NRC have investigated the implementation of risk-based concept into seismic design. The implementation of risk-based concept into regulation and seismic design makes it possible to consider various uncertainties and to improve accountability. Therefore, we need to develop the methods for evaluating seismic risk of structures, and to correlate seismic margin and seismic risk quantitatively. Moreover, the probabilistic method of earthquake ground motions, that is required in the risk-based design, should be applied to sites in Japan. (author)

Galvanic coupling effects for module-mounting elements of ground-mounted photovoltaic power station

Directory of Open Access Journals (Sweden)

Pierozynski Boguslaw

2017-12-01

Full Text Available This communication reports on the concerns associated with possible generation of galvanic coupling effects for construction materials that are used to manufacture mounting assemblies for ground-mounted photovoltaic (PV power stations. For this purpose, six macro-corrosion galvanic cells were assembled, including: hot-dip Zn/Magnelis®-coated steel/Al and stainless steel (SS/Al cells. Corrosion experiments involved continuous, ca. three-month exposure of these couplings in 3 wt.% NaCl solution, conducted at room temperature for a stable pH value of around 8. All corrosion cells were subjected to regular assessment of galvanic current-density and potential parameters, where special consideration was given to compare the corrosion behaviour of Zn-coated steel samples with that of Magnelis®-coated electrodes. Characterization of surface condition and elemental composition for examined materials was carried-out by means of SEM and EDX spectroscopy techniques.

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.

System for detecting and limiting electrical ground faults within electrical devices

International Nuclear Information System (INIS)

Gaubatz, D.C.

1990-01-01

This paper discusses, in a nuclear power plant of a variety wherein a reactor is provided including a reactor vessel retaining a liquid metal coolant, a reactor core and an electromagnetic pump having inductive windings insulatively retained within the electrically conductive wall of an enclosure, the method for controlling electrical ground fault current between a the inductive winding and the walls. It comprises providing an electrically isolated power source by inductive coupling with the plant power supply; rectifying the power source to provide an isolated d.c. power source; providing an inverter powered from the isolated d.c. power source under the control of the plant control system for selectively energizing the inductive windings; providing a fault control conductor electrically connected with the pump enclosure wall and extending as an electrical return for ground fault current to the inverter; and providing an electrical resistance between the conductor and the isolated inverter having an impedance selected to limit the fault current below a predetermined value limiting arc damage at any the electrical ground fault location

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.

Evaluation of stability of foundation ground during earthquake, (5)

International Nuclear Information System (INIS)

Nishi, Koh-ichi; Kanatani, Mamoru

1987-01-01

The Central Research Institute of Electric Power Industry advances the research on the method of evaluating foundation grounds from the standpoint of developing in-situ ground survey testing method and the method of evaluating mechanical properties in the studies on the technology for siting nuclear power stations on Quaternary grounds. The newly developed analytical technique on ground stability by the results of the analytical method for equivalent linear response was already reported. In this paper, the analytical method for nonlinear response to investigate into the more detailed behavior of ground due to strong earthquake motion is reported. In particular, the constitutive relation based on elastoplasticity was newly proposed in order to represent the deformation behavior during cyclic loading, and the examples of its application to the response of horizontally leveled sandy ground to earthquake are described. The dialatancy characteristics of soil are constituted by yield function, plastic potential functioin and hardening function. The material constants in proposed constitutive relation are easily determined by laboratory tests. One-dimensional response analysis was conducted, using the constitutive relation. (Kako, I.)

Evaluation and summary of seismic response of above ground nuclear power plant piping to strong motion earthquakes

International Nuclear Information System (INIS)

Stevenson, J.D.

1985-01-01

The purpose of this paper is to summarize the observations and experience which has been developed relative to the seismic behavior of above-ground, building-supported, industrial type piping (similar to piping used in nuclear power plants) in strong motion earthquakes. The paper also contains observations regarding the response of piping in experimental tests which attempted to excite the piping to failure. Appropriate conclusions regarding the behavior of such piping in large earthquakes and recommendations as to future design of such piping to resist earthquake motion damage are presented based on observed behavior in large earthquakes and simulated shake table testing

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

DEFF Research Database (Denmark)

Simonsen, Dorthe Gert

The paper examines the embodiment of aviation in its earliest decades. Drawing on theories of enactment and affect in recent studies of technology and mobility, I investigate the entanglements between airplanes and human bodies as well as the relations between aerial and earthbound bodies....... At a time when airplanes were little more than cloth wings attached to motors, their assembly with the body of the aviator was highly visible and essential in the practice and perception of powered flight. Perhaps less visible, but no less essential in this perception, was the embodied experience...... 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...

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.

Effect of earthquake and tsunami. Ground motion and tsunami observed at nuclear power station

International Nuclear Information System (INIS)

Hijikata, Katsuichirou

2012-01-01

Fukushima Daiichi and Daini Nuclear Power Stations (NPSs) were struck by the earthquake off the pacific coast in the Tohoku District, which occurred at 14:46 on March 11, 2011. Afterwards, tsunamis struck the Tohoku District. In terms of the earthquake observed at the Fukushima NPSs, the acceleration response spectra of the earthquake movement observed on the basic board of reactor buildings exceeded the acceleration response spectra of the response acceleration to the standard seismic ground motion Ss for partial periodic bands at the Fukushima Daiichi NPS. As for the Fukushima Daini NPS, the acceleration response spectra of the earthquake movement observed on the basic board of the reactor buildings was below the acceleration response spectra of the response acceleration to the standard seismic ground motion Ss. Areas inundated by Tsunami at each NPS were investigated and tsunami inversion analysis was made to build tsunami source model to reproduce tide record, tsunami height, crustal movement and inundated area, based on tsunami observation records in the wide areas from Hokkaido to Chiba prefectures. Tsunami heights of Fukushima Daiichi and Daini NPSs were recalculated as O.P. +13m and +9m respectively and tsunami peak height difference was attributed to the extent of superposition of tsunami waves of tsunami earthquake type of wave source in the area along interplane trench off the coast in the Fukushima prefecture and interplane earthquake type of wave source in rather deep interplate area off the coast in the Miyagi prefecture. (T. Tanaka)

NRC Information No. 88-86: Operating with multiple grounds in direct current distribution systems

International Nuclear Information System (INIS)

Rossi, C.E.

1992-01-01

During recent NRC maintenance inspections at Quad Cities, Oconee, and D.C. Cook power reactor facilities, it was found that plants had been operating with multiple grounds in the dc distribution systems for extended periods. Specific examples are described. Most nuclear power plant dc systems are two-wire ungrounded, combination battery/charger systems equipped with ground detection. Typical ground detection system features include a remote annunciator and a local indicator and/or recorder. Ground detectors are incorporated in the dc system so that if a single ground point does occur, immediate steps can be taken to clear the ground fault from the system. Failure to respond to a single ground will mask subsequent grounds. Multiple grounds can cause the indiscriminate operation of equipment, which may have safety consequences. Grounds can cause control circuit fuses to fail and can render important safety equipment inoperable as previously described. Furthermore, batteries have a designed capacity to supply power during a station blackout condition, and this capacity can be affected by the presence of unanalyzed loads in the form of multiple grounds. It is recognized that troubleshooting and finding grounds on a dc system are difficult tasks that may affect plant operation. The licensees previously mentioned have reviewed their designs and conditions for potential impact on safety system operability and have taken corrective actions to minimize the effect of grounds

Evaluation of stability of foundation ground during earthquake, (1)

International Nuclear Information System (INIS)

Nishi, Koichi; Kanatani, Mamoru; Matsui, Ietaka; Touma, Jun-ichi

1986-01-01

The Central Research Institute of Electric Power Industry has advanced the research on the new location technology for nuclear power stations in order to cope with the lack of sites expected in near future. The sites on rock mass are usually used for nuclear power stations, but the location on quaternary ground, particularly on gravel ground, is one of such new technology, to which attention has been paid. It has been pointed out that this location has the advantage in the earthquake response of reactor buildings and equipment, and the prospect to ensure the stability by lowering underground water level and pile penetration has been obtained, therefore, the possibility of its realization is high. At present, the research aiming at the establishment of the method of evaluating foundation ground stability is in progress, and it is expected that the quantitative evaluation means for the aseismatic stability of quaternary ground is obtained. In this paper, the analysis techniques for forecasting the amount of subsidence at the time of earthquakes occurring accompanying the generation of excessive pore water pressure and its disappearance are reported. Also the applicability of the forecasting techniques was experimentally verified. (Kako, I.)

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.

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.

Confirmation test on the dynamic interaction between a model reactor-building foundation and ground in the Sendai Nuclear Power Station

International Nuclear Information System (INIS)

Umezu, Hideo; Kisaki, Noboru; Shiota, Mutsumi

1982-01-01

On the site of unit 2 (planned) in the Sendai Nuclear Power Station, a model reactor-building foundation of reinforced concrete with diameter of 12 m and height of 5 m was installed. With a vibration generator, its forced vibration tests were carried out in October to December, 1980. Valuable data were able to be obtained on the dynamic interaction between the model foundation and the ground, and also the outlook for the application of theories in hard base rock was obtained. (1) The resonance frequency of the model foundation in horizontal vibration was 35 Hz in both NS and EW directions. (2) Remarkable difference was not observed in the horizontal vibration behavior between NS and EW directions, so that there is not anisotropy in the ground. (3) The model foundation was deformed nearly as a rigid body. (J.P.N.)

Monitoring Cs-134 and 137 released by Fukushima Dai-ichi Nuclear Power Plant accident in ground, soil, and stream waters

Science.gov (United States)

Tsujimura, Maki; Onda, Yuichi; Hada, Manami; Ishwar, Pun; Abe, Yutaka

2013-04-01

Due to Fukushima Dai-ichi Nuclear power plant accident occurred in March 2011, large amount of radionuclides was released into the atmosphere and was fallen onto ground by rainfall. Few researches have monitored radioactive cesium dynamics in whole hydrological cycle system such as groundwater, soil water, spring water and stream water. Thus, the purpose of this study is to monitor concentration of radioactive cesium in those waters in time series in the headwaters. We have performed an intensive monitoring at three small mountainous catchments in Yamakiya district, Kawamata town, Fukushima prefecture, locating 35 km northwest from Fukushima Dai-ichi Nuclear Power Plant since June 2011, also we consider the movement of radioactive cesium and its relation with the hydrological cycle.

The electrical system of nuclear power plant

International Nuclear Information System (INIS)

Firman Silitonga; Gunarwan Prayitno

2009-01-01

In these system, electrical power system is supplied from two-offsite transmission system respective main transformer and house service transformer; and reserve transformer. The electrical load in these system consist of safety electrical system and non-safety electrical system, The safety electrical and non safety electrical systems consist of four 6,9 kV AC medium voltage bus and 480 V AC low voltage bus system. The DC power system consist of four safety 125 V DC power system and the two non-safety 125 DC power systems. The equipment in these electrical system is main turbine-generator; GTG safety; GTG alternate; uninterrupted power supply (UPS) and battery system. To protect electrical equipment and building to direct stroke and non direct stroke disturbances is installed netral grounding system and lightning protection and protection the personnel to touch-voltage is installed equipment grounding system and station grounding. The lightning arrester system is connected to station station grounding system. (author)

Design basis ground motion (Ss) required on new regulatory guide

International Nuclear Information System (INIS)

Kamae, Katsuhiro

2013-01-01

New regulatory guide is enforced on July 8. Here, it is introduced how the design basis ground motion (Ss) for seismic design of nuclear power reactor facilities was revised on the new guide. Ss is formulated as two types of earthquake ground motions, earthquake ground motions with site specific earthquake source and with no such specific source locations. The latter is going to be revised based on the recent observed near source ground motions. (author)

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

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.

Wind uplift of radioactive dust from the ground

International Nuclear Information System (INIS)

Makhon'ko, K.P.

1992-01-01

Near nuclear power plants the recontamination of the atmosphere near the ground becomes dangerous, if a radioactive zone has formed at the site. Wind can easily carry toxic dust from the polluted territory of neighboring industrial enterprises. Moreover, wind erosion of the soil during the summer or transport of radioactive snow by a snowstorm during the winter can displace the boundaries of the contaminated radioactive zone. In Russia the investigation of wind pickup of radioactive dust from the ground began after a radiation accident occurred at a storage facility in the Southern Urals in 1957, as a result of which a contaminated zone formed in the area. Since the direct mechanism of detachment of dust particles from the ground is not important in studying the results of the raising of radioactive dust into the atmosphere by wind, the authors do not distinguish between wind pickup and wind erosion, and the entire process wind pickup of radioactivity from the ground. After the radiation accident at the Chernobyl nuclear power plant a new generation of investigators began to study wind pickup of radioactive dust from the ground, and the process under consideration was sometimes referred to as wind uplift. The intensity of the process of wind pickup of radioactive dust from the ground is characterized by the wind pickup coefficient α, which is the coefficient of proportionality between the upward flux Q of radioactivity from the ground and the density A of radioactive contamination of the ground: α = Q/A. Physically, the coefficient α is the upward flux of the impurity from the ground with unit contamination density, i.e., the intensity of dust contamination or the fraction of radioactivity picked up by the wind from the ground per unit time. The greatest difficulty in determining α experimentally under dusty conditions is measuring correctly the upward radioactivity flux Q. The author discusses three methods for determining this quantity

Compensation for incoherent ground motion

International Nuclear Information System (INIS)

Shigeru, Takeda; Hiroshi, Matsumoto; Masakazu, Yoshioka; Yasunori, Takeuchi; Kikuo, Kudo; Tsuneya, Tsubokawa; Mitsuaki, Nozaki; Kiyotomo, Kawagoe

1999-01-01

The power spectrum density and coherence function for ground motions are studied for the construction of the next generation electron-positron linear collider. It should provide a center of mass energy between 500 GeV-1 TeV with luminosity as high as 10 33 to 10 34 cm -2 sec -1 . Since the linear collider has a relatively slow repetition rate, large number of particles and small sizes of the beam should be generated and preserved in the machine to obtain the required high luminosity. One of the most critical parameters is the extremely small vertical beam size at the interaction point, thus a proper alignment system for the focusing and accelerating elements of the machine is necessary to achieve the luminosity. We describe recent observed incoherent ground motions and an alignment system to compensate the distortion by the ground motions. (authors)

Analytical and finite element modeling of grounding systems

Energy Technology Data Exchange (ETDEWEB)

Luz, Mauricio Valencia Ferreira da [University of Santa Catarina (UFSC), Florianopolis, SC (Brazil)], E-mail: mauricio@grucad.ufsc.br; Dular, Patrick [University of Liege (Belgium). Institut Montefiore], E-mail: Patrick.Dular@ulg.ac.be

2007-07-01

Grounding is the art of making an electrical connection to the earth. This paper deals with the analytical and finite element modeling of grounding systems. An electrokinetic formulation using a scalar potential can benefit from floating potentials to define global quantities such as electric voltages and currents. The application concerns a single vertical grounding with one, two and three-layer soil, where the superior extremity stays in the surface of the soil. This problem has been modeled using a 2D axi-symmetric electrokinetic formulation. The grounding resistance obtained by finite element method is compared with the analytical one for one-layer soil. With the results of this paper it is possible to show that finite element method is a powerful tool in the analysis of the grounding systems in low frequencies. (author)

Performance Analysis of Slinky Horizontal Ground Heat Exchangers for a Ground Source Heat Pump System

Directory of Open Access Journals (Sweden)

Md. Hasan Ali

2017-10-01

Full Text Available This paper highlights the thermal performance of reclined (parallel to ground surface and standing (perpendicular to ground surface slinky horizontal ground heat exchangers (HGHEs with different water mass flow rates in the heating mode of continuous and intermittent operations. A copper tube with an outer surface protected with low-density polyethylene was selected as the tube material of the ground heat exchanger. Effects on ground temperature around the reclined slinky HGHE due to heat extraction and the effect of variation of ground temperatures on reclined HGHE performance are discussed. A higher heat exchange rate was experienced in standing HGHE than in reclined HGHE. The standing HGHE was affected by deeper ground temperature and also a greater amount of backfilled sand in standing HGHE (4.20 m3 than reclined HGHE (1.58 m3, which has higher thermal conductivity than site soil. For mass flow rate of 1 L/min with inlet water temperature 7 °C, the 4-day average heat extraction rates increased 45.3% and 127.3%, respectively, when the initial average ground temperatures at 1.5 m depth around reclined HGHE increased from 10.4 °C to 11.7 °C and 10.4 °C to 13.7 °C. In the case of intermittent operation, which boosted the thermal performance, a short time interval of intermittent operation is better than a long time interval of intermittent operation. Furthermore, from the viewpoint of power consumption by the circulating pump, the intermittent operation is more efficient than continuous operation.

Adding Theoretical Grounding to Grounded Theory: Toward Multi-Grounded Theory

OpenAIRE

Göran Goldkuhl; Stefan Cronholm

2010-01-01

The purpose of this paper is to challenge some of the cornerstones of the grounded theory approach and propose an extended and alternative approach for data analysis and theory development, which the authors call multi-grounded theory (MGT). A multi-grounded theory is not only empirically grounded; it is also grounded in other ways. Three different grounding processes are acknowledged: theoretical, empirical, and internal grounding. The authors go beyond the pure inductivist approach in GT an...

TARDEC Ground Vehicle Robotics: Vehicle Dynamic Characterization and Research

Science.gov (United States)

2015-09-01

subassemblies that would be common on ground vehicles. Powertrain Systems: Gas Powered, Diesel , Turbo Diesel , Gas Turbine, Hybrid: Gas- Electric...PROPULSE (Hybrid Diesel - Electric System with Export Power), Command Zone (integrated vehicle control and diagnostic system), and TerraMax (Unmanned... Diesel -Electric, Series, Parallel. Power Distribution: RWD, FWD, AWD, open diff, LSD, Torsen diff, differential braking (traction control), drive by

A Study on the Improvement Effect and Field Applicability of the Deep Soft Ground by Ground Heating Method

Directory of Open Access Journals (Sweden)

Mincheol Park

2018-05-01

Full Text Available The soft ground in coastal areas should be treated when it needs to be used for the sustainably developed of urban or industrial complex constructions. The ground heating method for soft ground improvement was applied in Eastern Europe in the 1960s, but it was not widely used due to economic and environmental problems. The author developed a device for improving soft ground using an electric heating pipe. This paper investigates the improvement effect and field application of deep soft ground by the ground heating method using the electric heating pipe. Ground heating increases the temperature of the deep soft ground and increases the tip resistance of the static electronic piezo-cone penetration test. Additionally, the pressure of the pore water decreases because the pore water is evaporated due to the ground heating. As a result of the experiment, it was verified that there was an improvement in the effect of deep soft ground by the ground heating method. With ground heating for 96 h, the tip resistance was increased by 61% at a point 0.35 m horizontally away from the electric heat pipe, 22% at 0.97 m, and 2% at 1.31 m. As a result of the field test, it was found that there were no problems in the power supply of the diesel generator and the control panel. It was easy to install the electric heating pipes in the deep soft ground. However, due to boring, the ground was disturbed and water vapor was discharged through this gap. To minimize the discharge of water vapor, it is necessary to drive the electric heating pipe.

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

International Nuclear Information System (INIS)

Choi, In Kil; Ahn, Seong Moon; Choun, Young Sun; Seo, Jeong Moon

2004-01-01

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

The atlas of large photovoltaic power plants

International Nuclear Information System (INIS)

Ducuing, S.; Guillier, A.; Guichard, M.A.

2015-01-01

This document reports all the photovoltaic power plants whose installed power is over 1 MWc and that are operating in France or in project. 446 power plants have been reviewed and their cumulated power reaches 2822 MWc. For each plant the following information is listed: the name of the municipality, the operator, the power capacity, the manufacturer of the photovoltaic panels and the type of technology used, the type of installation (on the ground, on the roof, on the facade, as sun protection,...), the yearly power output (kWh), and the date of commissioning. This review shows that 86% of these plants are ground-based. (A.C.)

Sail GTS ground system analysis: Avionics system engineering

Science.gov (United States)

Lawton, R. M.

1977-01-01

A comparison of two different concepts for the guidance, navigation and control test set signal ground system is presented. The first is a concept utilizing a ground plate to which crew station, avionics racks, electrical power distribution system, master electrical common connection assembly and marshall mated elements system grounds are connected by 4/0 welding cable. An alternate approach has an aluminum sheet interconnecting the signal ground reference points between the crew station and avionics racks. The comparison analysis quantifies the differences between the two concepts in terms of dc resistance, ac resistance and inductive reactance. These parameters are figures of merit for ground system conductors in that the system with the lowest impedance is the most effective in minimizing noise voltage. Although the welding cable system is probably adequate, the aluminum sheet system provides a higher probability of a successful system design.

Ground Truth Collections at the MTI Core Sites

International Nuclear Information System (INIS)

Garrett, A.J.

2001-01-01

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

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

Preliminary Failure Modes, Effects and Criticality Analysis (FMECA) of the Brayton Isotope Power System (BIPS) Ground Demonstration System. Report 76-311965

International Nuclear Information System (INIS)

Miller, L.G.

1976-01-01

A Failure Modes, Effects and Criticality Analysis (FMECA) has been made of the Brayton Isotope Power System Ground Demonstration System (BIPS-GDS). Details of the analysis are discussed. The BIPS Flight System was recently analyzed in an AIRPHX report. Since the results of the Flight System FMECA are directly applicable to the BIPS to be tested in the GDS mode, the contents of the earlier FMECA have not been repeated in this current analysis. The BIPS-FS FMECA has been reviewed and determined to be essentially current

Dissolved oxygen mapping: A powerful tool for site assessments and ground water monitoring

International Nuclear Information System (INIS)

Newman, W.A.; Kimball, G.

1992-01-01

Dissolved oxygen concentration profiles often provide an excellent indication of the natural biological activity of microorganisms in ground water. The analysis of dissolved oxygen in ground water also provides a rapid, inexpensive method for determining the areal extent of contaminant plumes containing aerobically degraded compounds such as petroleum hydrocarbons. Indigenous hydrocarbon degrading organisms are present at most petroleum product spills giving this technique an almost universal application for dissolved hydrocarbons in ground water. Data from several sites will be presented to demonstrate the relationship between oxygen and dissolved contaminant concentrations. The inverse relationship between oxygen concentrations and dissolved contaminants can be used in many ways. During the initial site assessment, rapid on-site testing of ground water can provide real time data to direct drilling by identification of potentially contaminated locations. Several analytical techniques are available that allow field analysis to be performed in less than five minutes. Dissolved oxygen testing also provides an inexpensive way to monitor hydrocarbon migration without expensive gas chromatography. Often a plume of oxygen depleted ground water extends farther downgradient than the dissolved hydrocarbon plume. The depletion of oxygen in a well can provide an early warning system that detects upgradient contamination before the well is impacted by detectable levels of contaminants. Another application is the measurement of the natural degradation potential for aerobic remediation. If an aerobic in-situ remediation is used, dissolved oxygen monitoring provides an inexpensive method to monitor the progress of the remediation

Probabilistic considerations on the effects of random soil properties on the stability of ground structures of nuclear power plants

International Nuclear Information System (INIS)

Ootori, Yasuki; Ishikawa, Hiroyuki; Takeda, Tomoyoshi

2004-01-01

In the JEAG4601-1987 (Japan Electric Association Guide for earthquake resistance design), either the conventional deterministic method or probabilistic method is used for evaluating the stability of ground foundations and surrounding slopes in nuclear power plants. The deterministic method, in which the soil properties of 'mean ± coefficient x standard deviation' is adopted for the calculations, is generally used in the design stage to data. On the other hand, the probabilistic method, in which the soil properties assume to have probabilistic distributions, is stated as a future method. The deterministic method facilitates the evaluation, however, it is necessary to clarify the relationship between the deterministic and probabilistic methods. In order to investigate the relationship, a simple model that can take into account the dynamic effect of structures, and a simplified method for taking the spatial randomness into account are proposed in this study. As a result, it is found that the shear strength of soil is the most important factor for the stability of grounds and slopes, and the probability below the safety factor evaluated with the soil properties of mean - 1.0 x standard deviation' by the deterministic methods of much lower. (author)

Simulated earthquake ground motions

International Nuclear Information System (INIS)

Vanmarcke, E.H.; Gasparini, D.A.

1977-01-01

The paper reviews current methods for generating synthetic earthquake ground motions. Emphasis is on the special requirements demanded of procedures to generate motions for use in nuclear power plant seismic response analysis. Specifically, very close agreement is usually sought between the response spectra of the simulated motions and prescribed, smooth design response spectra. The features and capabilities of the computer program SIMQKE, which has been widely used in power plant seismic work are described. Problems and pitfalls associated with the use of synthetic ground motions in seismic safety assessment are also pointed out. The limitations and paucity of recorded accelerograms together with the widespread use of time-history dynamic analysis for obtaining structural and secondary systems' response have motivated the development of earthquake simulation capabilities. A common model for synthesizing earthquakes is that of superposing sinusoidal components with random phase angles. The input parameters for such a model are, then, the amplitudes and phase angles of the contributing sinusoids as well as the characteristics of the variation of motion intensity with time, especially the duration of the motion. The amplitudes are determined from estimates of the Fourier spectrum or the spectral density function of the ground motion. These amplitudes may be assumed to be varying in time or constant for the duration of the earthquake. In the nuclear industry, the common procedure is to specify a set of smooth response spectra for use in aseismic design. This development and the need for time histories have generated much practical interest in synthesizing earthquakes whose response spectra 'match', or are compatible with a set of specified smooth response spectra

Ground motion measurement at Sefuri and Esashi area

International Nuclear Information System (INIS)

Sugahara, R.; Takeda, S.; Nozaki, M.; Yamaoka, H.; Yamashita, S.; Nakayama, Y.

2008-02-01

It is indispensable for the construction of the next-generation super high-energy accelerator to investigate the ground fluctuation and to get the information on the characteristics of ground vibration. KEK, ICEPP, and J-Power have cooperatively measured the usual tremor of various grounds. This report describes the results of the measurements carried out at the tunnel in Mise Expressway penetrating the Sefuri Mountains forming the boundary between Fukuoka and Saga prefectures and at the facility of Esashi earth tide measurement, National Astronomical Observatory. The comparison with past measurements on other area and the characteristics of wide band usual tremor of each area are also mentioned. (M.H.)

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...

Preliminary development of a wing in ground effect vehicle

Science.gov (United States)

Abidin, Razali; Ahamat, Mohamad Asmidzam; Ahmad, Tarmizi; Saad, Mohd Rasdan; Hafizi, Ezzat

2018-02-01

Wing in ground vehicle is one of the mode of transportation that allows high speed movement over water by travelling few meters above the water level. Through this manouver strategy, a cushion of compressed air exists between the wing in ground vehicle wings and water. This significantly increase the lift force, thus reducing the necessity in having a long wing span. Our project deals with the development of wing in ground vehicle with the capability of transporting four people. The total weight of this wing in ground vehicle was estimated at 5.4 kN to enable the prediction on required wing area, minimum takeoff velocity, drag force and engine power requirement. The required takeoff velocity is decreases as the lift coefficient increases, and our current mathematical model shows the takeoff velocity at 50 m/s avoid the significant increase in lift coefficient for the wing area of 5 m2. At the velocity of 50 m/s, the drag force created by this wing in ground vehicle is well below 1 kN, which required a 100-120 kW of engine power if the propeller has the efficiency of 0.7. Assessment on the stresses and deflection of the hull structural indicate the capability of plywood to withstand the expected load. However, excessive deflection was expected in the rear section which requires a minor structural modification. In the near future, we expect that the wind tunnel tests of this wing in ground vehicle model would enable more definite prediction on the important parameters related to its performance.

Open System of Agile Ground Stations, Phase I

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...

A fiber Bragg grating acceleration sensor for ground surveillance

Science.gov (United States)

Jiang, Shaodong; Zhang, Faxiang; Lv, Jingsheng; Ni, Jiasheng; Wang, Chang

2017-10-01

Ground surveillance system is a kind of intelligent monitoring equipment for detecting and tracking the ground target. This paper presents a fiber Bragg grating (FBG) acceleration sensor for ground surveillance, which has the characteristics of no power supply, anti-electromagnetic interference, easy large-scale networking, and small size. Which make it able to achieve the advantage of the ground surveillance system while avoiding the shortcoming of the electric sensing. The sensor has a double cantilever beam structure with a sensitivity of 1000 pm/g. Field experiment has been carried out on a flood beach to examine the sensor performance. The result shows that the detection distance on the walking of personnel reaches 70m, and the detection distance on the ordinary motor vehicle reaches 200m. The performance of the FBG sensor can satisfy the actual needs of the ground surveillance system.

Ground-Fault Characteristic Analysis of Grid-Connected Photovoltaic Stations with Neutral Grounding Resistance

Directory of Open Access Journals (Sweden)

Zheng Li

2017-11-01

Full Text Available A centralized grid-connected photovoltaic (PV station is a widely adopted method of neutral grounding using resistance, which can potentially make pre-existing protection systems invalid and threaten the safety of power grids. Therefore, studying the fault characteristics of grid-connected PV systems and their impact on power-grid protection is of great importance. Based on an analysis of the grid structure of a grid-connected PV system and of the low-voltage ride-through control characteristics of a photovoltaic power supply, this paper proposes a short-circuit calculation model and a fault-calculation method for this kind of system. With respect to the change of system parameters, particularly the resistance connected to the neutral point, and the possible impact on protective actions, this paper achieves the general rule of short-circuit current characteristics through a simulation, which provides a reference for devising protection configurations.

Local figure-ground cues are valid for natural images.

Science.gov (United States)

Fowlkes, Charless C; Martin, David R; Malik, Jitendra

2007-06-08

Figure-ground organization refers to the visual perception that a contour separating two regions belongs to one of the regions. Recent studies have found neural correlates of figure-ground assignment in V2 as early as 10-25 ms after response onset, providing strong support for the role of local bottom-up processing. How much information about figure-ground assignment is available from locally computed cues? Using a large collection of natural images, in which neighboring regions were assigned a figure-ground relation by human observers, we quantified the extent to which figural regions locally tend to be smaller, more convex, and lie below ground regions. Our results suggest that these Gestalt cues are ecologically valid, and we quantify their relative power. We have also developed a simple bottom-up computational model of figure-ground assignment that takes image contours as input. Using parameters fit to natural image statistics, the model is capable of matching human-level performance when scene context limited.

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

Transient evaluation using EMTP at single open phase with the offsite power transformer for the emergency power supply systems of nuclear power plants

International Nuclear Information System (INIS)

Shimada, Yoshio

2017-01-01

The emergency power supply systems of nuclear power plants, as the objects of this research, are critical in supplying stable electric power to such systems as the emergency core cooling system (ECCS), and in maintaining safety of the nuclear power reactor; this was apparent in the accident at the Fukushima Daiichi Nuclear Power Station. The Nuclear Regulatory Commission (USNRC) issued regulatory documents (BL 2012-011, IN 2012-032), and has commenced evaluations on newly discovered vulnerability in the design of power supply systems which cannot be detected with under-voltage protection relays, with certain kinds of configuration of coils and iron core structures, such as when the offsite power supply side is a Y-connection and the load side is a ⊿-connection etc., when the detection of single open phase fault with the circuit of a transformer which is without a ground fault connected to the offsite power supply system. This report uses simulation by the electro magnetic transients program (EMTP) and clearly describe the response at the time of the power supply single open phase without ground fault for various configuration of coils and various iron core structures of the three-phase transformer, and identify the important issues in the response of emergency power supply systems and the safety related components of representative domestic PWR plants when the single open phase fault occurred without ground fault. This report describes the results of the simulations of operations of the protection relays of the emergency power supply systems and the safety related components of representative a domestic PWR plant with EMTP. This report explains the method to detect open-phase when the transformer is no-load which United States Electric Power Research Institute (EPRI) developed. As the detailed analyses data from EPRI related to the detection method concerned have not been disclosed officially yet, in this paper, the quantitative and detailed verification results

The ground-fault detection system for DIII-D

International Nuclear Information System (INIS)

Scoville, J.T.; Petersen, P.I.

1987-10-01

This paper presents a discussion of the ground-fault detection systems on the DIII-D tokamak. The subsystems that must be monitored for an inadvertent ground include the toroidal and poloidal coil systems, the vacuum vessel, and the coil support structures. In general, one point of each coil is tied to coil/power supply ground through a current limiting resistor. For ground protection the current through this resistor is monitored using a dynamically feedback balanced Hall probe transducer from LEM Industries. When large inductive currents flow in closed loops near the tokamak, the result is undesirable magnetic error fields in the plasma region and noise generation on signal cables. Therefore, attention must be paid to avoid closed loops in the design of the coil and vessel support structure. For DIII-D a concept of dual insulating breaks and a single-point ground for all structure elements was used to satisfy this requirement. The integrity of the support structure is monitored by a system which continuously attempts to couple a variable frequency waveform onto these single-point grounds. The presence of an additional ground completes the circuit resulting in current flow. A Rogowski coil is then used to track the unwanted ground path in order to eliminate it. Details of the ground fault detection circuitry, and a description of its operation will be presented. 2 refs., 7 figs

A new digital ground-fault protection system for generator-transformer unit

Energy Technology Data Exchange (ETDEWEB)

Zielichowski, Mieczyslaw; Szlezak, Tomasz [Institute of Electrical Power Engineering, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, 50370 Wroclaw (Poland)

2007-08-15

Ground faults are one of most often reasons of damages in stator windings of large generators. Under certain conditions, as a result of ground-fault protection systems maloperation, ground faults convert into high-current faults, causing severe failures in power system. Numerous publications in renowned journals and magazines testify about ground-fault matter importance and problems reported by exploitators confirm opinions, that some issues concerning ground-fault protection of large generators have not been solved yet or have been solved insufficiently. In this paper a new conception of a digital ground-fault protection system for stator winding of large generator was proposed. The process of intermittent arc ground fault in stator winding has been briefly discussed and actual ground-fault voltage waveforms were presented. A new relaying algorithm, based on third harmonic voltage measurement was also drawn and the methods of its implementation and testing were described. (author)

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…

Procedures for evaluation of vibratory ground motions of soil deposits at nuclear power plant sites

International Nuclear Information System (INIS)

1975-06-01

According to USNRC requirements set forth in Appendix A, 10 CFR, Part 100, vibratory ground motion criteria for a nuclear plant must be based on local soil conditions, as well as on the seismicity, geology, and tectonics of the region. This report describes how such criteria can be developed by applying the latest technology associated with analytical predictions of site-dependent ground motions and with the use of composite spectra obtained from the current library of strong motion records. Recommended procedures for defining vibratory ground motion criteria contain the following steps: (1) geologic and seismologic studies; (2) site soils investigations; (3) site response sensitivity studies; (4) evaluation of local site response characteristics; (5) selection of site-matched records; and (6) appraisal and selection of seismic input criteria. An in-depth discussion of the engineering characteristics of earthquake ground motions including parameters used to characterize earthquakes and strong motion records, geologic factors that influence ground shaking, the current strong motion data base, and case histories of the effects of past earthquake events is presented. Next, geotechnical investigations of the seismologic, geologic, and site soil conditions required to develop vibratory motion criteria are briefly summarized. The current technology for establishing vibratory ground motion criteria at nuclear plant sites, including site-independent and site-dependent procedures that use data from strong motion records and from soil response analyses is described. (auth)

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

DEFF Research Database (Denmark)

Hernández, Carlos Cilla

The power amplifier used in the transmitter of a microwave system is a key issue, and it derermines the system performance, cost, power consumption and reliability to a considerable extent. Traditionally, most of high power amplifiers used in military and commercial applications were tube......, the device was delivering power levels larger than 75 W, PAE >35% and gain oscillating between 7.5 +/- 0.5 dB. Measurements were shifted down in frequency 1 GHz, but simulations predicted maximum power levels similar to the ones measured....

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

Atmospheric turbulence profiling with unknown power spectral density

Science.gov (United States)

Helin, Tapio; Kindermann, Stefan; Lehtonen, Jonatan; Ramlau, Ronny

2018-04-01

Adaptive optics (AO) is a technology in modern ground-based optical telescopes to compensate for the wavefront distortions caused by atmospheric turbulence. One method that allows to retrieve information about the atmosphere from telescope data is so-called SLODAR, where the atmospheric turbulence profile is estimated based on correlation data of Shack-Hartmann wavefront measurements. This approach relies on a layered Kolmogorov turbulence model. In this article, we propose a novel extension of the SLODAR concept by including a general non-Kolmogorov turbulence layer close to the ground with an unknown power spectral density. We prove that the joint estimation problem of the turbulence profile above ground simultaneously with the unknown power spectral density at the ground is ill-posed and propose three numerical reconstruction methods. We demonstrate by numerical simulations that our methods lead to substantial improvements in the turbulence profile reconstruction compared to the standard SLODAR-type approach. Also, our methods can accurately locate local perturbations in non-Kolmogorov power spectral densities.

TFTR grounding scheme and ground-monitor system

International Nuclear Information System (INIS)

Viola, M.

1983-01-01

The Tokamak Fusion Test Reactor (TFTR) grounding system utilizes a single-point ground. It is located directly under the machine, at the basement floor level, and is tied to the building perimeter ground. Wired to this single-point ground, via individual 500 MCM insulated cables, are: the vacuum vessel; four toroidal field coil cases/inner support structure quadrants; umbrella structure halves; the substructure ring girder; radial beams and columns; and the diagnostic systems. Prior to the first machine operation, a ground-loop removal program was initiated. It required insulation of all hangers and supports (within a 35-foot radius of the center of the machine) of the various piping, conduits, cable trays, and ventilation systems. A special ground-monitor system was designed and installed. It actively monitors each of the individual machine grounds to insure that there are no inadvertent ground loops within the machine structure or its ground and that the machine grounds are intact prior to each pulse. The TFTR grounding system has proven to be a very manageable system and one that is easy to maintain

Ground effect on a self-propelled undulatory foil

Science.gov (United States)

Zhang, Dong; Chao, Liming; Pan, Guang

2018-04-01

The unsteady ground effect on a self-propelled undulatory foil is numerically investigated in this paper. The situation can be widely found in nature especially for fish swimming near the ground. In this study, frequency varies from 0.1 Hz to 2 Hz and distance from the ground varies from 0.2 L to 1 L. Under most kinematics, the ground has a negative effect on the performance of the foil. The swimming velocity slows down, power spend increases and swimming economy reduces. The higher frequency can produce a larger negative effect. Only at the low frequencies f = 0.1 Hz, 0.25 Hz and 0.5 Hz with distance of 0.2 L the velocity can be enhanced by 18%, 6%, 0.8%, respectively. The lift production is found to be increased. The link between the performance and the wake dynamics is also established by studying the vortex structures.

Figure-ground: history and practice of a planning technique

OpenAIRE

Hebbert, M.

2016-01-01

Figure-ground plans show the footprints of buildings and the pattern of unbuilt voids in urban space. Compared historically they reveal the erosion of the public realm over time and provide an analytical basis for tissue repair. The paper traces the communicative power of figure-ground technique to its roots in gestalt psychology, and follows its revival from Colin Rowe’s studio at Cornell through to controversies in post-reunification Berlin. The impact of computerisation is discussed and th...

Earthquake ground-motion in presence of source and medium heterogeneities

KAUST Repository

Vyas, Jagdish Chandra

2017-01-01

This dissertation work investigates the effects of earthquake rupture complexity and heterogeneities in Earth structure on near-field ground-motions. More specifically, we address two key issues in seismology: (1) near-field ground-shaking variability as function of distance and azimuth for unilateral directive ruptures, and (2) impact of rupture complexity and seismic scattering on Mach wave coherence associated with supershear rupture propagation. We examine earthquake ground-motion variability associated with unilateral ruptures based on ground-motion simulations of the MW 7.3 1992 Landers earthquake, eight simplified source models, and a MW 7.8 rupture simulation (ShakeOut) for the San Andreas fault. Our numerical modeling reveals that the ground-shaking variability in near-fault distances (< 20 km) is larger than that given by empirical ground motion prediction equations. In addition, the variability decreases with increasing distance from the source, exhibiting a power-law decay. The high near-field variability can be explained by strong directivity effects whose influence weaken as we move away from the fault. At the same time, the slope of the power-law decay is found to be dominantly controlled by slip heterogeneity. Furthermore, the ground-shaking variability is high in the rupture propagation direction whereas low in the directions perpendicular to it. However, the variability expressed as a function of azimuth is not only sensitive to slip heterogeneity, but also to rupture velocity. To study Mach wave coherence for supershear ruptures, we consider heterogeneities in rupture parameters (variations in slip, rise time and rupture speed) and 3D scattering media having small-scale random heterogeneities. The Mach wave coherence is reduced at near-fault distances (< 10 km) by the source heterogeneities. At the larger distances from the source, medium scattering plays the dominant role in reducing the Mach wave coherence. Combined effect of the source and

Techniques for enhancing durability and equivalence ratio control in a rich-lean, three-stage ground power gas turbine combustor

Science.gov (United States)

Schultz, D. F.

1982-01-01

Rig tests of a can-type combustor were performed to demonstrate two advanced ground power engine combustor concepts: steam cooled rich-burn combustor primary zones for enhanced durability; and variable combustor geometry for three stage combustion equivalence ratio control. Both concepts proved to be highly successful in achieving their desired objectives. The steam cooling reduced peak liner temperatures to less than 800 K. This offers the potential of both long life and reduced use of strategic materials for liner fabrication. Three degrees of variable geometry were successfully implemented to control airflow distribution within the combustor. One was a variable blade angle axial flow air swirler to control primary airflow while the other two consisted of rotating bands to control secondary and tertiary or dilution air flow.

Transient evaluation using EMTP at one phase opening of the offsite power transformer of the emergency power supply systems for nuclear power plants. This report is a follow-up the last year's

International Nuclear Information System (INIS)

Shimada, Yoshio

2014-01-01

The emergency power supply systems of nuclear power plants, as the objects of this research, are critical to supplying stable electric power to such systems as the emergency core cooling system (ECCS), and to maintaining the safety of the nuclear power reactor; this was apparent from the accident at the Fukushima Daiichi Nuclear Power Station. The USNRC issued regulatory documents (BL 2012-01, IN 2012-03), and has commenced to review those problems which cannot be detected by degraded-voltage protection relays such as new design vulnerability of the power supply systems that are certain kinds of winding structures and iron core structures when the one-phase open fault occurs without a ground fault of the transformer connected to the offsite power supply system, including when the offsite power supply side is a wye connection and the load side is a delta connection etc. The report of the INSS JOURNAL 2013 used simulation by the electro-magnetic transients program (EMTP) and obtained findings that clearly specified the response at the time of the power supply side one-phase open without ground fault of various winding structures and various iron core structures of the three-phase transformer and identified the important issues for the response of emergency power supply systems and the safety related components of representative domestic PWR plants when the one-phase open fault occurred without ground fault. In a continuation of the previous report, this paper summarizes the previous results, and then presents the principles by which normal voltages are maintained by both the primary and the secondary sides when the one-phase open failure without ground fault occurs on the primary side of the transformer, and the results of the analysis of operations of the protection relays of the emergency power systems and the safety related components of representative a domestic PWR plant by the simulation using EMTP. (author)

Nuclear power flies high

International Nuclear Information System (INIS)

Friedman, S.T.

1983-01-01

Nuclear power in aircraft, rockets and satellites is discussed. No nuclear-powered rockets or aircraft have ever flown, but ground tests were successful. Nuclear reactors are used in the Soviet Cosmos serles of satellites, but only one American satellite, the SNAP-10A, contained a reactor. Radioisotope thermoelectric generators, many of which use plutonium 238, have powered more than 20 satellites launched into deep space by the U.S.A

Asymmetrical short circuits in medium-voltage networks with grounded neutral through resistance

Energy Technology Data Exchange (ETDEWEB)

Tanasescu, M.; Maries, H.

1981-01-01

This article introduces the concepts of ''damage to ground'' and ''current to ground indicator'', which characterize the efficiency of the operating mode of the neutral. The values of these two indicators are assigned by directive (eletric power plan design instruction PE109/1980) and must be provided when selecting the parameters of compensating devices installed in the neutral. Possible aymmetrical short circuits in medium-voltage networks with neutral ground are examined. Formulas are derived for determining the short-circuiting currents and undamaged phase voltages in order to determine the damage to ground indicator and ground current indicator; an example of a calculation is given.

Research on advancement of method for evaluating aseismatic ability of rock discontinuity plane in ground and surrounding slopes of nuclear power facilities

International Nuclear Information System (INIS)

Kusunose, Kinichiro; Cho, Akio; Takahashi, Manabu; Kamai, Toshitaka

1997-01-01

The purpose of this research is to carry out the technical development required for exploring with high accuracy the distribution and shapes of the discontinuity planes in rocks in the ground and surrounding cut-off slopes of nuclear power facilities, and to advance the techniques of interpreting and evaluating quantitatively the stability against earthquakes of the discontinuity planes. This research consists of two themes: the research on the method of investigating the three-dimensional distribution of the crevices in the ground and the research on the method of evaluating the aseismatic ability in the slopes. As for the first theme, one of the techniques for exploring underground structure with elastic waves, tomography, is explained, and the development of the 12 channel receiver and the program for the multi-channel analysis and processing of waveform are reported. As for the second theme, the stability analysis was carried out on three actual cases of landslide. The equation for stability analysis is shown, and the results are reported. The strength at the time of forming separation plane gives the most proper result. (K.I.)

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.

Nuclear power plant siting: Hydrogeologic aspects

International Nuclear Information System (INIS)

1984-01-01

This Safety Guide gives guidelines and methods for determining the ground water concentration of radionuclides that could result from postulated releases from nuclear power plants. The Guide gives recommendations on the data to be collected and the investigations to be performed at various stages of nuclear power plant siting in relation to the various aspects of the movement of accidentally released radioactive material through the ground water, the selection of an appropriate mathematical or physical model for the hydrodynamic dispersion even two-phase distribution of the radioactive material and an appropriate monitoring programme

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.

High-Altitude Wind Power Generation

NARCIS (Netherlands)

Fagiano, L.; Milanese, M.; Piga, D.

2010-01-01

Abstract—The paper presents the innovative technology of highaltitude wind power generation, indicated as Kitenergy, which exploits the automatic flight of tethered airfoils (e.g., power kites) to extract energy from wind blowing between 200 and 800 m above the ground. The key points of this

Single-event effect ground test issues

International Nuclear Information System (INIS)

Koga, R.

1996-01-01

Ground-based single event effect (SEE) testing of microcircuits permits characterization of device susceptibility to various radiation induced disturbances, including: (1) single event upset (SEU) and single event latchup (SEL) in digital microcircuits; (2) single event gate rupture (SEGR), and single event burnout (SEB) in power transistors; and (3) bit errors in photonic devices. These characterizations can then be used to generate predictions of device performance in the space radiation environment. This paper provides a general overview of ground-based SEE testing and examines in critical depth several underlying conceptual constructs relevant to the conduct of such tests and to the proper interpretation of results. These more traditional issues are contrasted with emerging concerns related to the testing of modern, advanced microcircuits

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.

Integrated Unmanned Air-Ground Robotics System, Volume 4

Science.gov (United States)

2001-08-20

3) IPT Integrated Product Team IRP Intermediate Power Rating JAUGS TBD JCDL TBD Joint Vision 2020 TBD Km Kilometer lbs. pounds MAE Mechanical and...compatible with emerging JCDL and/or JAUGS . 2.3.2.2. Payload must be “plug and play.” 2.3.3. Communications 2.3.3.1. System communications shall be robust...Power JCDL JAUGS Joint Architecture for Unmanned Ground Systems JP-8 Jet Propulsion Fuel 8 km Kilometer lbs. Pounds LOS Line Of Sight MAE Mechanical

Seismic fragility analysis of a CANDU containment structure for near-fault ground motions

International Nuclear Information System (INIS)

Choi, In Kil; Choun, Young Sun; Seo, Jeong Moon; Ahn, Seong Moon

2005-01-01

The R. G. 1.60 spectrum used for the seismic design of Korean nuclear power plants provides a generally conservative design basis due to its broadband nature. 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 these faults. The probability based scenario earthquakes were identified as near-field earthquakes. 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. It is necessary to estimate the near-fault ground motion effects on the nuclear power plant structures and components located near the faults. In this study, the seismic fragility analysis of a CANDU containment structure was performed based on the results of nonlinear dynamic time-history analyses

Power Aware Distributed Systems

National Research Council Canada - National Science Library

Schott, Brian

2004-01-01

The goal of PADS was to study power aware management techniques for wireless unattended ground sensor applications to extend their operational lifetime and overall capabilities in this battery-constrained environment...

Response characteristics of reactor building on weathered soft rock ground

International Nuclear Information System (INIS)

Hirata, Kazuta; Tochigi, Hitoshi

1991-01-01

The purpose of this study is to investigate the seismic stability of nuclear power plants on layered soft bedrock grounds, focusing on the seismic response of reactor buildings. In this case, the soft bedrock grounds refer to the weathered soft bedrocks with several tens meter thickness overlaying hard bedrocks. Under this condition, there are two subjects regarding the estimation of the seismic response of reactor buildings. One is the estimation of the seismic response of surface ground, and another is the estimation of soil-structure interaction characteristics for the structures embedded in the layered grounds with low impedandce ratio between the surface ground and the bedrock. Paying attention to these subjects, many cases of seismic response analysis were carried out, and the following facts were clarified. In the soft rock grounds overlaying hard bedrocks, it was proved that the response acceleration was larger than the case of uniform hard bedrocks. A simplified sway and rocking model was proposed to consider soil-structure interaction. It was proved that the response of reactor buildings was small when the effect of embedment was considered. (K.I.)

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.

Study of grounding system of large tokamak device JT-60

International Nuclear Information System (INIS)

Arakawa, Kiyotsugu; Shimada, Ryuichi; Kishimoto, Hiroshi; Yabuno, Kohei; Ishigaki, Yukio.

1982-01-01

In the critical plasma testing facility JT-60 constructed by the Japan Atomic Energy Research Institute, high voltage, large current is required in an instant. Accordingly, for the protection of human bodies and the equipment, and for realizing the stable operation of the complex, precise control and measurement system, a large scale facility of grounding system is required. In case of the JT-60 experimental facility, the equipments with different functions in separate buildings are connected, therefore, it is an important point to avoid high potential difference between buildings. In the grounding system for the JT-60, a reticulate grounding electrode is laid for each building, and these electrodes are connected with a low impedance metallic duct called grounding trunk line. The power supply cables for various magnetic field coils, control lines and measurement lines are laid in the duct. It is a large problem to grasp quantitatively the effect of a grounding trunk line by analysis. The authors analyzed the phenomenon that large current flows into a grounding system by lightning strike or grounding. The fundamental construction of the grounding system for the JT-60, the condition for the analysis and the result of simulation are reported. (Kako, I.)

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.

Analytical technical of lightning surges induced on grounding mesh of PWR nuclear power plant

International Nuclear Information System (INIS)

Ikeda, I.; Tani, M.; Yonezawa, T.

1990-01-01

An analytical lightning surge technique is needed to make a qualitative and predictive evaluation of transient voltages induced on local grounding meshes and instrumentation cables by a lightning strike on a lightning rod in a PWR plant. This paper discusses an experiment with lightning surge impulses in a PWR plant which was setup to observe lightning caused transient voltages. Experimental data when compared with EMTP simulation results improved the simulation method. The improved method provides a good estimation of induced voltages on grounding meshes and instrumentation cables

Non-power application as an entry point to nuclear power program

International Nuclear Information System (INIS)

Nahrul Khair Alang Md Rashid

2009-01-01

Nuclear power is usually viewed as the flagship of nuclear technology. A nuclear power plant complex, visible and prominence, is iconic of the technology. That image makes its presence common knowledge to the extent that nuclear technology is equated almost totally with nuclear power by the general public. The downside of this visibility is that it becomes easy target in public misinformation programs. The non-power applications however are not visible, and devoid of icon. The non-power applications, therefore, can grow quite smoothly, attracting only little attention in the negative and in the positive senses. According to a study conducted in the USA in 2000 and in Japan in 2002, the socio-economic impact of non-power and power applications of nuclear technology are comparable. Involvement in non-power applications can be a good grounding for moving into power applications. This paper discusses the non-power nuclear technology applications and in what manner it can serve to prepare the introduction of nuclear power program. (Author)

Ground motion characteristics of 2007 Niigata-ken Chuetsu-oki earthquake

International Nuclear Information System (INIS)

Hijikata, Katsuichirou; Nishimura, Isao; Mizutani, Hiroyuki; Tokumitsu, Ryoichi; Mashimo, Mitsugu; Tanaka, Shinya

2010-01-01

Strong motion records of 2007 Niigata-ken Chuetsu-oki earthquake were examined in order to evaluate ground motion characteristics of the earthquake. Ground motions observed at Kashiwazaki Kariwa Nuclear Power Plant site were significantly larger than the response spectra evaluated on the basis of Noda et al. (2002), and the level of the ground motion observed at Arahama area (unit 1-4 side) was approximately twice as large as that at Ominato area (unit 5-7 side). Observation records of the offshore events other than the earthquake were also larger than the response spectra based on Noda et al. (2002), whereas records of the inland events were smaller than those. In addition, these characteristics were also observed in the vicinity of the site through the analysis of the ground motion records obtained by KiK-net. (author)

Empirical and pragmatic adequacy of grounded theory: Advancing nurse empowerment theory for nurses' practice.

Science.gov (United States)

Udod, Sonia A; Racine, Louise

2017-12-01

To draw on the findings of a grounded theory study aimed at exploring how power is exercised in nurse-manager relationships in the hospital setting, this paper examines the empirical and pragmatic adequacy of grounded theory as a methodology to advance the concept of empowerment in the area of nursing leadership and management. The evidence on staff nurse empowerment has highlighted the magnitude of individual and organisational outcomes, but has not fully explicated the micro-level processes underlying how power is exercised, shared or created within the nurse-manager relationship. Although grounded theory is a widely adopted nursing research methodology, it remains less used in nursing leadership because of the dominance of quantitative approaches to research. Grounded theory methodology provides the empirical and pragmatic relevance to inform nursing practice and policy. Grounded theory is a relevant qualitative approach to use in leadership research as it provides a fine and detailed analysis of the process underlying complexity and bureaucracy. Discursive paper. A critical examination of the empirical and pragmatic relevance of grounded theory by (Corbin & Strauss, , ) as a method for analysing and solving problems in nurses' practice is provided. This paper provides evidence to support the empirical and pragmatic adequacy of grounded theory methodology. Although the application of the ontological, epistemological and methodological assumptions of grounded theory is challenging, this methodology is useful to address real-life problems in nursing practice by developing theoretical explanations of nurse empowerment, or lack thereof, in the workplace. Grounded theory represents a relevant methodology to inform nursing leadership research. Grounded theory is anchored in the reality of practice. The strength of grounded theory is to provide results that can be readily applied to clinical practice and policy as they arise from problems that affect practice and that

Power plant fault detection using artificial neural network

Science.gov (United States)

Thanakodi, Suresh; Nazar, Nazatul Shiema Moh; Joini, Nur Fazriana; Hidzir, Hidzrin Dayana Mohd; Awira, Mohammad Zulfikar Khairul

2018-02-01

The fault that commonly occurs in power plants is due to various factors that affect the system outage. There are many types of faults in power plants such as single line to ground fault, double line to ground fault, and line to line fault. The primary aim of this paper is to diagnose the fault in 14 buses power plants by using an Artificial Neural Network (ANN). The Multilayered Perceptron Network (MLP) that detection trained utilized the offline training methods such as Gradient Descent Backpropagation (GDBP), Levenberg-Marquardt (LM), and Bayesian Regularization (BR). The best method is used to build the Graphical User Interface (GUI). The modelling of 14 buses power plant, network training, and GUI used the MATLAB software.

Applications of power beaming from space-based nuclear power stations

International Nuclear Information System (INIS)

Powell, J.R.; Botts, T.E.; Hertzberg, A.

1981-01-01

Power beaming from space-based reactor systems is examined using an advanced compact, lightweight Rotating Bed Reactor (RBR). Closed Brayton power conversion efficiencies in the range of 30 to 40% can be achieved with turbines, with reactor exit temperatures on the order of 2000 0 K and a liquid drop radiator to reject heat at temperatures of approx. 500 0 K. Higher RBR coolant temperatures (up to approx. 3000 0 K) are possible, but gains in power conversion efficiency are minimal, due to lower expander efficiency (e.g., a MHD generator). Two power beaming applications are examined - laser beaming to airplanes and microwave beaming to fixed ground receivers. Use of the RBR greatly reduces system weight and cost, as compared to solar power sources. Payback times are a few years at present prices for power and airplane fuel

Reactive power compensator

Science.gov (United States)

El-Sharkawi, Mohamed A.; Venkata, Subrahmanyam S.; Chen, Mingliang; Andexler, George; Huang, Tony

1992-01-01

A system and method for determining and providing reactive power compensation for an inductive load. A reactive power compensator (50,50') monitors the voltage and current flowing through each of three distribution lines (52a, 52b, 52c), which are supplying three-phase power to one or more inductive loads. Using signals indicative of the current on each of these lines when the voltage waveform on the line crosses zero, the reactive power compensator determines a reactive power compensator capacitance that must be connected to the lines to maintain a desired VAR level, power factor, or line voltage. Alternatively, an operator can manually select a specific capacitance for connection to each line, or the capacitance can be selected based on a time schedule. The reactive power compensator produces control signals, which are coupled through optical fibers (102/106) to a switch driver (110, 110') to select specific compensation capacitors (112) for connections to each line. The switch driver develops triggering signals that are supplied to a plurality of series-connected solid state switches (350), which control charge current in one direction in respect to ground for each compensation capacitor. During each cycle, current flows from ground to charge the capacitors as the voltage on the line begins to go negative from its positive peak value. The triggering signals are applied to gate the solid state switches into a conducting state when the potential on the lines and on the capacitors reaches a negative peak value, thereby minimizing both the potential difference and across the charge current through the switches when they begin to conduct. Any harmonic distortion on the potential and current carried by the lines is filtered out from the current and potential signals used by the reactive power compensator so that it does not affect the determination of the required reactive compensation.

Reactive power compensator

Energy Technology Data Exchange (ETDEWEB)

El-Sharkawi, Mohamed A. (Renton, WA); Venkata, Subrahmanyam S. (Woodinville, WA); Chen, Mingliang (Kirkland, WA); Andexler, George (Everett, WA); Huang, Tony (Seattle, WA)

1992-01-01

A system and method for determining and providing reactive power compensation for an inductive load. A reactive power compensator (50,50') monitors the voltage and current flowing through each of three distribution lines (52a, 52b, 52c), which are supplying three-phase power to one or more inductive loads. Using signals indicative of the current on each of these lines when the voltage waveform on the line crosses zero, the reactive power compensator determines a reactive power compensator capacitance that must be connected to the lines to maintain a desired VAR level, power factor, or line voltage. Alternatively, an operator can manually select a specific capacitance for connection to each line, or the capacitance can be selected based on a time schedule. The reactive power compensator produces control signals, which are coupled through optical fibers (102/106) to a switch driver (110, 110') to select specific compensation capacitors (112) for connections to each line. The switch driver develops triggering signals that are supplied to a plurality of series-connected solid state switches (350), which control charge current in one direction in respect to ground for each compensation capacitor. During each cycle, current flows from ground to charge the capacitors as the voltage on the line begins to go negative from its positive peak value. The triggering signals are applied to gate the solid state switches into a conducting state when the potential on the lines and on the capacitors reaches a negative peak value, thereby minimizing both the potential difference and across the charge current through the switches when they begin to conduct. Any harmonic distortion on the potential and current carried by the lines is filtered out from the current and potential signals used by the reactive power compensator so that it does not affect the determination of the required reactive compensation.

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.

Nuclear power in rock. Principal report

International Nuclear Information System (INIS)

1977-06-01

In September 1975 the Swedish Government directed the Swedish State Power Board to study the question of rock-siting nuclear power plants. The study accounted for in this report aims at clarifying the advantages and disadvantages of siting a nuclear power plant in rock, compared to siting on ground level, considering reactor safety, war protection and sabotage. The need for nuclear power production during war situations and the closing down of nuclear power plants after terminated operation are also dealt with. (author)

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.

Suppression of Adverse Effects of GIC Using Controlled Variable Grounding Resistor

Science.gov (United States)

Abuhussein, A.; Ali, M. H.

2016-12-01

Geomagnetically induced current (GIC) has a harmful impact on power systems, with a large footprint. Mitigation strategies for the GIC are required to protect the integrity of the power system. To date, the adverse effects of GIC are being mitigated by either operational procedures or grounding fixed capacitors (GFCs). The operational procedures are uncertain, reduce systems' reliability, and increase energy losses. On the other hand, GFCs, incur voltage spikes, increase the transformer cost substantially, and require protection circuitry. This study investigates new possible approaches to cope with GIC, by using a controlled variable grounding resistor (CVGR), without interfering with the system's normal operation. In addition, the new techniques help suppress unsymmetrical faults in the power network. The controllability of the grounding resistor is applied using three different techniques: (1) a Parallel switch that is controlled by PI regulated duty cycle, (2) a Parallel switch that is triggered by a preset values in a look-up-table (LUT), and (3) a Mechanical resistor varied by a Fuzzy logic controller (FLC). The experimental results were obtained and validated using the MATLAB/SIMULINK software. A hypothetical power system that consists of a generator, a 765kv, 500 km long transmission lines connecting between a step-up, Δ-Yn, transformer, and a step-down, Yn-Δ, transformer, is considered. The performance of the CVGR is compared with that of the GFC under the cases of GIC event and unsymmetrical faults. From the simulation results, the following points are concluded: The CVGR effectively suppresses the GIC flowing in the system. Consequently, it protects the transformers from saturation and the rest of the system from collapsing. The CVGR also reduces the voltage and power swings associated with unsymmetrical faults and blocks the zero sequence current flowing through the neutral of the transformer. The performance of the CVGR surpasses that of the GFC in

Cost estimate guidelines for advanced nuclear power technologies

International Nuclear Information System (INIS)

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

Cost estimate guidelines for advanced nuclear power technologies

International Nuclear Information System (INIS)

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

Observations of magnetohydrodynamic waves on the ground and on a satellite

International Nuclear Information System (INIS)

Lanzerotti, L.J.; Fukunishi, H.; Maclennan, C.G.; Cahill, L.J. Jr.

1976-01-01

A comparison is made of magnetohydrodynamic waves observed near the equator on Explorer 45 and at an array of ground stations in the northern hemisphere and at their conjugate station at Siple, Antartica. The data comparisons strongly support the notion that the observed waves can be considered odd mode standing waves in the magnetosphere. This conclusion has important implications for the interpretation of single-point satellite and/or ground measurements of ULF plasma wave phenomena in the magnetosphere. Further, the data comparisons strongly suggest that the overall ULF (approx.5-30 mHz) power levels are quite similar in the magnetosphere and on the ground, at least during the intervals studied

Ground temperature estimation through an energy balance method

Energy Technology Data Exchange (ETDEWEB)

Duan, X. [Manitoba Univ., Winnipeg, MB (Canada); Naterer, G.F. [Univ. of Ontario Inst. of Technology, Oshawa, ON (Canada)

2007-07-01

A joint research project by the University of Manitoba and the University of Ontario Institute of Technology (UOIT) is currently examining ground thermal responses to heat conduction within power transmission line towers. The aim of the study is to develop thermal protection alternatives for the freezing and thawing conditions that typically lead to the tilting and heaving of tower foundations. The analysis presented in this paper focused on the temperatures of areas undisturbed by tower foundations. The ground was approximated as a semi-infinite homogenous system with a sinusoidal variation of ground temperature and constant thermophysical properties. Solar radiation and air temperature data were used to develop the sinusoidal profiles. The far-field temperature was modeled using a 1-D transient heat conduction equation. Geothermal gradients were neglected. The energy balance method was used for boundary conditions at the ground surface. Energy components included heat conduction through the ground; heat convection due to wind; net radiative heat transfer; and latent heat transfer due to evaporation. Newton's law of cooling was used to model the convective heat transfer. The model was used to predict ground temperature under varying conditions. Monthly variations of temperature at 2 meters depth were calculated using different evaporation fractions. The model was also used to estimate summer ground temperature at a site in Manitoba. Air temperature, wind velocity and solar radiation data were used. It was suggested that further research is needed to consider the effects of freezing, thawing, and winter snow cover. 2 refs., 1 tab., 2 figs.

Methods of formation of efficiency indexes of electric power sources integration in regional electric power systems

International Nuclear Information System (INIS)

Marder, L.I.; Myzin, A.I.

1993-01-01

A methodic approach to the grounding of the integration process efficiency within the Unified electric power system is given together with the selection of a rational areal structure and concentration of power-generating source capacities. Formation of an economic functional according to alternative scenavies including the cost components taking account of the regional interests is considered. A method for estimation and distribution of the effect from electric power production integration in the power systems under new economic conditions is proposed

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.

Ground Pollution Science

International Nuclear Information System (INIS)

Oh, Jong Min; Bae, Jae Geun

1997-08-01

This book deals with ground pollution science and soil science, classification of soil and fundamentals, ground pollution and human, ground pollution and organic matter, ground pollution and city environment, environmental problems of the earth and ground pollution, soil pollution and development of geological features of the ground, ground pollution and landfill of waste, case of measurement of ground pollution.

The settlement of foundation of existing large structure on soft ground and investigation of its allowable settlement

International Nuclear Information System (INIS)

Okamoto, Toshiro

1987-01-01

In our laboratory a study of siting on quarternary ground is followed to make possible to construct a nuclear power plant on soil ground in Japan, a important subject is to understand bearing capacity, settlement and seismic responce of foundation. So measured data are collected about relation between ground and type of foundation, total settlement and differential settlement of already constructed large structures, and it is done to investigate the real condition and to examine allowable settlement. Investigated structures are mainly foreign nuclear power plant and domestic and foreign high buildings. The higher buildings are, the more raft foundation are for type of foundation and the higher contact pressure are to similar to a nuclear power plant. So discussion is done about mainly raft foundation. It is found that some measured maximum total settlements are larger than already proposed allowable values. So empirical allowable settlement is derived from measured values considering the effect of the width of base slab, contact pressure and foundation ground. Differential settlement is investigated about relation to maximum total settlement, and is formulated considering the width and the rigidity of base slab. Beside the limit of differential settlement is obtained as foundation is damaged, and the limit of maximum total settlement is obtained by combining this and above mentioned relation. Obtained allowable value is largely influenced by the width of base slab, and becomes less severe than some already proposed values. So it is expected that deformation of foundation is rationaly investigated when large structure as nuclear power plant is constructed on soft ground. (author)

Computational Power of Symmetry-Protected Topological Phases.

Science.gov (United States)

Stephen, David T; Wang, Dong-Sheng; Prakash, Abhishodh; Wei, Tzu-Chieh; Raussendorf, Robert

2017-07-07

We consider ground states of quantum spin chains with symmetry-protected topological (SPT) order as resources for measurement-based quantum computation (MBQC). We show that, for a wide range of SPT phases, the computational power of ground states is uniform throughout each phase. This computational power, defined as the Lie group of executable gates in MBQC, is determined by the same algebraic information that labels the SPT phase itself. We prove that these Lie groups always contain a full set of single-qubit gates, thereby affirming the long-standing conjecture that general SPT phases can serve as computationally useful phases of matter.

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

A comparison of the different regulatory requirements of NPP in vertical ground motion

International Nuclear Information System (INIS)

Hou Chunlin; Pan Rong; Yang Yu; Wang Shuguo; Li Xiaojun

2015-01-01

Based on the importance of vertical motion in the nuclear power plants (NPPs) and equipment identification of seismic test, we summarize the existing laws and regulations cited by China's NPPs in the vertical seismic ground motion of the regulations. Then, according to the interpretation of various laws and regulations content, we may identified four vertical earthquake response spectrums. Finally, combined with the seismic safety requirements of China NPPs evaluation and the vertical seismic design of M310, EPR, AP1000 and CAP1400 pressurized water reactor, we explain that the vertical seismic ground motion selection should distinguish the effects between near field and far field earthquake, the existing regulations and specifications that China used are still required to further improve on the selection of vertical ground motion. The results of this study can provide reference for seismic design of China's nuclear power plant and nuclear safety review. (authors)

Ground level enhancement (GLE) energy spectrum parameters model

Science.gov (United States)

Qin, G.; Wu, S.

2017-12-01

We study the ground level enhancement (GLE) events in solar cycle 23 with the four energy spectra parameters, the normalization parameter C, low-energy power-law slope γ 1, high-energy power-law slope γ 2, and break energy E0, obtained by Mewaldt et al. 2012 who fit the observations to the double power-law equation. we divide the GLEs into two groups, one with strong acceleration by interplanetary (IP) shocks and another one without strong acceleration according to the condition of solar eruptions. We next fit the four parameters with solar event conditions to get models of the parameters for the two groups of GLEs separately. So that we would establish a model of energy spectrum for GLEs for the future space weather prediction.

Engineering characterization of ground motion. Task II: Soil structure interaction effects on structural response

Energy Technology Data Exchange (ETDEWEB)

Luco, J E; Wong, H L [Structural and Earthquake Engineering Consultants, Inc., Sierra Madre, CA (United States); Chang, C -Y; Power, M S; Idriss, I M [Woodward-Clyde Consultants, Walnut Creek, CA (United States)

1986-08-01

This report presents the results of part of a two-task study on the engineering characterization of earthquake ground motion for nuclear power plant design. The overall objective of this research program sponsored by the U.S. Nuclear Regulatory Commission (USNRC) is to develop recommendations for methods for selecting design response spectra or acceleration time histories to be used to characterize motion at the foundation level of nuclear power plants. Task I of the study, which is presented in Vol. 1 of NUREG/CR-3805, developed a basis for selecting design response spectra taking into account the characteristics of free-field ground motion found to be significant in causing structural damage. Task II incorporates additional considerations of effects of spatial variations of ground motions and soil-structure interaction on foundation motions and structural response. The results of Task II are presented in Vols. 2 through of NUREG/CR-3805 as follows: Vol. 2 effects of ground motion characteristics on structural response considering localized structural nonlinearities and soil-structure interaction effects; Vol. 3 observational data on spatial variations of earthquake ground motions; Vol. 4 soil-structure interaction effects on structural response; and Vol. 5, summary based on Tasks I and II studies. This report presents the results of the Vol. 4 studies.

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.

Radiation Tolerant Low Power Precision Time Source, Phase I

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...

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.

Electric power generation

International Nuclear Information System (INIS)

Pinske, J.D.

1981-01-01

Apart from discussing some principles of power industry the present text deals with the different ways of electric power generation. Both the conventional methods of energy conversion in heating and water power stations and the facilities for utilizing regenerative energy sources (sun, wind, ground heat, tidal power) are considered. The script represents the essentials of the lecture of the same name which is offered to the students of the special subject 'electric power engineering' at the Fachhochschule Hamburg. It does not require any special preliminary knowledge except for the general principles of electrical engineering. It is addressing students of electrical engineering who have passed their preliminary examination at technical colleges and universities. Moreover, it shall also be of use for engineers who want to obtain a quick survey of the structure and the operating characteristics of the extremely different technical methods of power generation. (orig.) [de

Evaluation of stability of foundation ground during earthquake, 6

International Nuclear Information System (INIS)

Kanatani, Mamoru; Nishi, Koichi

1988-01-01

The aseismatic capability of nuclear power plants located on Quaternary grounds, which consist of dense sand or sandy gravel, is heavily dependent on the stability of foundation grounds during earthquakes. In order to investigate into the stability of ground more in detail, it is necessary to develop the nonlinear earthquake response analysis method which can simulate the inelastic behavior of soil. In this report, the newly developed nonlinear response analysis method based on the effective stress, the results of simulation using the results of vibration table test and centrifuge test, and the case studies on two-dimensional soil-structure interaction problems are described. Soil was regarded as the two-phase mixture composed of soil particle skeleton and pore water. In the equation of motion taking their interaction into account, the elastoplastic constitutive equation that can simulate the inelastic deformation behavior of soil at the time of repeated shearing in two or three-dimensional field was introduced, and the analysis code which successively traces the behavior of ground at the time of earthquakes using FEM was developed. (K.I.)

Cost estimate guidelines for advanced nuclear power technologies

International Nuclear Information System (INIS)

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

Characterization of design ground motion for the central and eastern United States: licensing implications

International Nuclear Information System (INIS)

Litehiser, J.; Carrato, P.

2005-01-01

For the first time in decades several US utilities are exploring the possibility of building new Nuclear Power Plant (NPP) generating capacity in the Central and Eastern United States (CEUS). Among the many topics that must be considered to license a nuclear plant (NPP) is appropriate design to mitigate the potential effects of vibratory ground motion from earthquakes. Agreement on seismic design ground motion was not always easy during licensing of the last generation of NPPs. Therefore, over the last few decades both industry and the United States Nuclear Regulatory Commission (USNRC) have worked to find ground motion criteria that recognize and overcome earlier licensing difficulties. Such criteria should be stable and easily implemented. Important and complementary programs under the direction of the Lawrence Livermore National Laboratory (LLNL) and the Electric Power Research Institute (EPRI) were part of this effort, and these studies resulted in probabilistic seismic hazard assessments (PSHAs) for a number of CEUS NPP sites. These results and the concepts underlying them are now incorporated into both USNRC regulation and regulatory guidance. Nevertheless, as the utilities and the NRC begin a renewed licensing dialog, issues of regulatory interpretation of earthquake ground motion design criteria have emerged. These issues are as fundamental as the shape and amplitude of ground motion design response spectra and as significant as the impact of these spectra on structural design. Successful and timely resolution of these issues will significantly impact the future of nuclear power in the US. The purpose of this paper is to briefly describe some of these issues and the approaches that have been proposed for their resolution. (authors)

Concept of underground nuclear power plant

International Nuclear Information System (INIS)

Onishi, Sotoaki

1976-01-01

The concept of constructing nuclear power plants on the sea or underground as the future sitting is based on moving the present power plants on the ground with actual results to the sea or underground without changing the design. The underground nuclear power plants have many similar points to underground hydro-electric power stations with many achievements in the construction viewpoint, though they have their proper difficult problems. Of course, it requires to excavate larger underground caves than the case of underground hydro-electric power plants. The maximum dimensions of the caves have been determined through experience in practice. Therefore the developments of design theory and construction technique are desirable in this field. In discussing underground construction, two evaluating methods are considered for the shielding effect of base rocks. The minimum vertical distance up to ground surface from the center of the cave differs depending upon the in-cave pressure, and the conditions of base rock, soil and underground water in case of the accident assumed in the design, and is approximately 60m, if the cave is assumed to be an indefinite cylindrical shape, by the safer side calculation in the above two evaluations. (Wakatsuki, Y.)

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.

Concept of ground facilities and the analyses of the factors for cost estimation

Energy Technology Data Exchange (ETDEWEB)

Lee, J. Y.; Choi, H. J.; Choi, J. W.; Kim, S. K.; Cho, D. K

2007-09-15

The geologic disposal of spent fuels generated from the nuclear power plants is the only way to protect the human beings and the surrounding environments present and future. The direct disposal of the spent fuels from the nuclear power plants is considered, and a Korean Reference HLW disposal System(KRS) suitable for our representative geological conditions have been developed. In this study, the concept of the spent fuel encapsulation process as a key of the above ground facilities for deep geological disposal was established. To do this, the design requirements, such as the functions and the spent fuel accumulations, were reviewed. Also, the design principles and the bases were established. Based on the requirements and the bases, the encapsulation process of the spent fuel from receiving spent fuel of nuclear power plants to transferring canister into the underground repository was established. Simulation for the above-ground facility in graphic circumstances through KRS design concept and disposal scenarios for spent nuclear fuel showed that an appropriate process was performed based on facility design concept and required for more improvement on construction facility by actual demonstration test. And, based on the concept of the above ground facilities for the Korean Reference HLW disposal System, the analyses of the factors for the cost estimation was carried out.

Non-Powered Spectrophotometry for Lighting

Data.gov (United States)

National Aeronautics and Space Administration — This process improvement innovation would like to suggest a non-powered method and tool set that can be developed to assist crewmembers and ground support teams with...

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.

Autonomously managed high power systems

International Nuclear Information System (INIS)

Weeks, D.J.; Bechtel, R.T.

1985-01-01

The need for autonomous power management capabilities will increase as the power levels of spacecraft increase into the multi-100 kW range. The quantity of labor intensive ground and crew support consumed by the 9 kW Skylab cannot be afforded in support of a 75-300 kW Space Station or high power earth orbital and interplanetary spacecraft. Marshall Space Flight Center is managing a program to develop necessary technologies for high power system autonomous management. To date a reference electrical power system and automation approaches have been defined. A test facility for evaluation and verification of management algorithms and hardware has been designed with the first of the three power channel capability nearing completion

Regression and kriging analysis for grid power factor estimation

Directory of Open Access Journals (Sweden)

Rajesh Guntaka

2014-12-01

Full Text Available The measurement of power factor (PF in electrical utility grids is a mainstay of load balancing and is also a critical element of transmission and distribution efficiency. The measurement of PF dates back to the earliest periods of electrical power distribution to public grids. In the wide-area distribution grid, measurement of current waveforms is trivial and may be accomplished at any point in the grid using a current tap transformer. However, voltage measurement requires reference to ground and so is more problematic and measurements are normally constrained to points that have ready and easy access to a ground source. We present two mathematical analysis methods based on kriging and linear least square estimation (LLSE (regression to derive PF at nodes with unknown voltages that are within a perimeter of sample nodes with ground reference across a selected power grid. Our results indicate an error average of 1.884% that is within acceptable tolerances for PF measurements that are used in load balancing tasks.

Symbolic interactionism in grounded theory studies: women surviving with HIV/AIDS in rural northern Thailand.

Science.gov (United States)

Klunklin, Areewan; Greenwood, Jennifer

2006-01-01

Although it is generally acknowledged that symbolic interactionism and grounded theory are connected, the precise nature of their connection remains implicit and unexplained. As a result, many grounded theory studies are undertaken without an explanatory framework. This in turn results in the description rather than the explanation of data determined. In this report, the authors make explicit and explain the nature of the connections between symbolic interactionism and grounded theory research. Specifically, they make explicit the connection between Blumer's methodological principles and processes and grounded theory methodology. In addition, the authors illustrate the explanatory power of symbolic interactionism in grounded theory using data from a study of the HIV/AIDS experiences of married and widowed Thai women.

High-Capacity Free-Space Optical Communications Between a Ground Transmitter and a Ground Receiver via a UAV Using Multiplexing of Multiple Orbital-Angular-Momentum Beams.

Science.gov (United States)

Li, Long; Zhang, Runzhou; Zhao, Zhe; Xie, Guodong; Liao, Peicheng; Pang, Kai; Song, Haoqian; Liu, Cong; Ren, Yongxiong; Labroille, Guillaume; Jian, Pu; Starodubov, Dmitry; Lynn, Brittany; Bock, Robert; Tur, Moshe; Willner, Alan E

2017-12-12

We explore the use of orbital-angular-momentum (OAM)-multiplexing to increase the capacity of free-space data transmission to moving platforms, with an added potential benefit of decreasing the probability of data intercept. Specifically, we experimentally demonstrate and characterize the performance of an OAM-multiplexed, free-space optical (FSO) communications link between a ground transmitter and a ground receiver via a moving unmanned-aerial-vehicle (UAV). We achieve a total capacity of 80 Gbit/s up to 100-m-roundtrip link by multiplexing 2 OAM beams, each carrying a 40-Gbit/s quadrature-phase-shift-keying (QPSK) signal. Moreover, we investigate for static, hovering, and moving conditions the effects of channel impairments, including: misalignments, propeller-induced airflows, power loss, intermodal crosstalk, and system bit error rate (BER). We find the following: (a) when the UAV hovers in the air, the power on the desired mode fluctuates by 2.1 dB, while the crosstalk to the other mode is -19 dB below the power on the desired mode; and (b) when the UAV moves in the air, the power fluctuation on the desired mode increases to 4.3 dB and the crosstalk to the other mode increases to -10 dB. Furthermore, the channel crosstalk decreases with an increase in OAM mode spacing.

Linear Power-Flow Models in Multiphase Distribution Networks: Preprint

Energy Technology Data Exchange (ETDEWEB)

Bernstein, Andrey; Dall' Anese, Emiliano

2017-05-26

This paper considers multiphase unbalanced distribution systems and develops approximate power-flow models where bus-voltages, line-currents, and powers at the point of common coupling are linearly related to the nodal net power injections. The linearization approach is grounded on a fixed-point interpretation of the AC power-flow equations, and it is applicable to distribution systems featuring (i) wye connections; (ii) ungrounded delta connections; (iii) a combination of wye-connected and delta-connected sources/loads; and, (iv) a combination of line-to-line and line-to-grounded-neutral devices at the secondary of distribution transformers. The proposed linear models can facilitate the development of computationally-affordable optimization and control applications -- from advanced distribution management systems settings to online and distributed optimization routines. Performance of the proposed models is evaluated on different test feeders.

AMS Ground Truth Measurements: Calibration and Test Lines

International Nuclear Information System (INIS)

Wasiolek, P.

2013-01-01

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.

The on-line electric vehicle wireless electric ground transportation systems

CERN Document Server

Cho, Dong

2017-01-01

This book details the design and technology of the on-line electric vehicle (OLEV) system and its enabling wireless power-transfer technology, the “shaped magnetic field in resonance” (SMFIR). The text shows how OLEV systems can achieve their three linked important goals: reduction of CO2 produced by ground transportation; improved energy efficiency of ground transportation; and contribution to the amelioration or prevention of climate change and global warming. SMFIR provides power to the OLEV by wireless transmission from underground cables using an alternating magnetic field and the reader learns how this is done. This cable network will in future be part of any local smart grid for energy supply and use thereby exploiting local and renewable energy generation to further its aims. In addition to the technical details involved with design and realization of a fleet of vehicles combined with extensive subsurface charging infrastructure, practical issues such as those involved with pedestrian safety are c...

Overview of ground coupled heat pump research and technology transfer activities

Science.gov (United States)

Baxter, V. D.; Mei, V. C.

Highlights of DOE-sponsored ground coupled heat pump (GCHP) research at Oak Ridge National Laboratory (ORNL) are presented. ORNL, in cooperation with Niagara Mohawk Power Company, Climate Master, Inc., and Brookhaven National Laboratory developed and demonstrated an advanced GCHP design concept with shorter ground coils that can reduce installed costs for northern climates. In these areas it can also enhance the competitiveness of GCHP systems versus air-source heat pumps by lowering their payback from 6 to 7 years to 3 to 5 years. Ground coil heat exchanger models (based primarily on first principles) have been developed and used by others to generate less conservative ground coil sizing methods. An aggressive technology transfer initiative was undertaken to publicize results of this research and make it available to the industry. Included in this effort were an international workshop, trade press releases and articles, and participation in a live teleconference on GCHP technology.

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.

Inelastic response evaluation of steel frame structure subjected to near-fault ground motions

Energy Technology Data Exchange (ETDEWEB)

Choi, In Kil; Kim, Hyung Kyu; Choun, Young Sun; Seo, Jeong Moon

2004-04-01

A survey on some of the Quaternary fault segments near the Korean nuclear power plants is ongoing. It is likely that these faults would be identified as active ones. If the faults are confirmed as active ones, it will be necessary to reevaluate the seismic safety of nuclear power plants located near the fault. This study was performed to acquire overall knowledge of near-fault ground motions and evaluate inealstic response characteristics of near-fault ground motions. Although Korean peninsular is not located in the strong earthquake region, it is necessary to evaluate seismic safety of NPP for the earthquakes occurred in near-fault area with characteristics different from that of general far-fault earthquakes in order to improve seismic safety of existing NPP structures and equipment. As a result, for the seismic safety evaluation of NPP structures and equipment considering near-fault effects, this report will give many valuable information. In order to improve seismic safety of NPP structures and equipment against near-fault ground motions, it is necessary to consider inelastic response characteristics of near-fault ground motions in current design code. Also in Korea where these studies are immature yet, in the future more works of near-fault earthquakes must be accomplished.

Ground cross-modal impedance as a tool for analyzing ground/plate interaction and ground wave propagation.

Science.gov (United States)

Grau, L; Laulagnet, B

2015-05-01

An analytical approach is investigated to model ground-plate interaction based on modal decomposition and the two-dimensional Fourier transform. A finite rectangular plate subjected to flexural vibration is coupled with the ground and modeled with the Kirchhoff hypothesis. A Navier equation represents the stratified ground, assumed infinite in the x- and y-directions and free at the top surface. To obtain an analytical solution, modal decomposition is applied to the structure and a Fourier Transform is applied to the ground. The result is a new tool for analyzing ground-plate interaction to resolve this problem: ground cross-modal impedance. It allows quantifying the added-stiffness, added-mass, and added-damping from the ground to the structure. Similarity with the parallel acoustic problem is highlighted. A comparison between the theory and the experiment shows good matching. Finally, specific cases are investigated, notably the influence of layer depth on plate vibration.

Environmental interactions and the SP-100 power system

International Nuclear Information System (INIS)

Ferguson, D.C.

1993-01-01

The Civil Space Technology Initiative High-Capacity-Power Environmental Interactions Program has made great progress in defining and evaluating the interactions of the SP-100 power system with its expected ambient environments. The NASCAP/LEO and POLAR computer codes demonstrated that local electric fields at the user interface module are high. Therefore, particular attention must be paid to geometries and materials in this region to prevent arcing at conductor-insulator junctions in low Earth orbit. NASCAP/LEO and EPSAT computer models revealed that SP-100 payloads float about 100 V negative of the LEO plasma. In addition, ground tests and modeling done for the Space Station Freedom Electrical Grounding Tiger Team found that dielectric coatings often break down at such voltages in a plasma. Thus, surface coatings for SP-100 payloads should be carefully selected. Sputtering may also be a concern for long-duration missions in LEO at these voltages. Much work has been done on a sputtering model to evaluate surface material loss rates on SP-100 payloads. In ground plasma chamber tests of cables and cable insulators at SP-100 voltages, parasitic power losses due to the plasma current collected from possible pinholes or coating defects were quantified and shown to be small. Modeling revealed that the power loss from currents to other surfaces is also small. The atomic oxygen durability of SP-100 materials and coatings continues to be investigated in ground tests. In the upcoming Evaluation of Oxygen Interaction with Materials (EOIM-3) Shuttle flight experiment, a host of SP-100 materials will be evaluated for atomic oxygen durability in LEO. Finally, an evaluation of the interactions of the SP-100 power system with lunar and planetary environments has started. At a workshop on chemical and electrical interactions on Mars recently held at the NASA Lewis Research Center, many of primary interactions were identified

Grounding and shielding in the accelerator environment

International Nuclear Information System (INIS)

Kerns, Q.

1991-01-01

Everyday features of the accelerator environment include long cable runs, high power and low level equipment sharing building space, stray electromagnetic fields and ground voltage differences between the sending and receiving ends of an installation. This paper pictures some Fermilab installations chosen to highlight significant features and presents practices, test methods and equipment that have been helpful in achieving successful shielding. Throughout the report are numbered statements aimed at summarizing good practices and avoiding pitfalls

Competition-strength-dependent ground suppression in figure-ground perception.

Science.gov (United States)

Salvagio, Elizabeth; Cacciamani, Laura; Peterson, Mary A

2012-07-01

Figure-ground segregation is modeled as inhibitory competition between objects that might be perceived on opposite sides of borders. The winner is the figure; the loser is suppressed, and its location is perceived as shapeless ground. Evidence of ground suppression would support inhibitory competition models and would contribute to explaining why grounds are shapeless near borders shared with figures, yet such evidence is scarce. We manipulated whether competition from potential objects on the ground side of figures was high (i.e., portions of familiar objects were potentially present there) or low (novel objects were potentially present). We predicted that greater competition would produce more ground suppression. The results of two experiments in which suppression was assessed via judgments of the orientation of target bars confirmed this prediction; a third experiment showed that ground suppression is short-lived. Our findings support inhibitory competition models of figure assignment, in particular, and models of visual perception entailing feedback, in general.

Regional analysis of ground and above-ground climate

Science.gov (United States)

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. 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 are included. 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 20 locations in the United States.

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.

OGM : vers une évaluation des impacts agri-environnementaux

Directory of Open Access Journals (Sweden)

Icart Jean-Claude

2000-07-01

Full Text Available En 1998, les pouvoirs publics français prononçaient un moratoire de deux ans concernant les autorisations de mise sur le marché des variétés de colza génétiquement modifiées. Cette décision donnait suite aux conclusions de la conférence des citoyens des 20 et 21 juin 1998 à l’Assemblée nationale et aux recommandations de l’Office parlementaire des choix scientifiques et technologiques, fondées sur « les incertitudes liées à la diffusion de transgène dans l’environnement à partir de plantes comme le colza, présentant des risques de croisements avec d’autres espèces ».

Engineering characterization of ground motion. Task I. Effects of characteristics of free-field motion on structural response

Energy Technology Data Exchange (ETDEWEB)

Kennedy, R.P.; Short, S.A.; Merz, K.L.; Tokarz, F.J.; Idriss, I.M.; Power, M.S.; Sadigh, K.

1984-05-01

This report presents the results of the first task of a two-task study on the engineering characterization of earthquake ground motion for nuclear power plant design. The overall objective of this study is to develop recommendations for methods for selecting design response spectra or acceleration time histories to be used to characterize motion at the foundation level of nuclear power plants. Task I of the study develops a basis for selecting design response spectra, taking into account the characteristics of free-field ground motion found to be significant in causing structural damage.

Engineering characterization of ground motion. Task I. Effects of characteristics of free-field motion on structural response

International Nuclear Information System (INIS)

Kennedy, R.P.; Short, S.A.; Merz, K.L.; Tokarz, F.J.; Idriss, I.M.; Power, M.S.; Sadigh, K.

1984-05-01

This report presents the results of the first task of a two-task study on the engineering characterization of earthquake ground motion for nuclear power plant design. The overall objective of this study is to develop recommendations for methods for selecting design response spectra or acceleration time histories to be used to characterize motion at the foundation level of nuclear power plants. Task I of the study develops a basis for selecting design response spectra, taking into account the characteristics of free-field ground motion found to be significant in causing structural damage

Efficient Desalination of Brackish Ground Water via a Novel Capacitive Deionization Cell Using Nanoporous Activated Carbon Cloth Electrodes

Directory of Open Access Journals (Sweden)

K. Laxman

2015-12-01

Full Text Available Sea water intrusion in ground water sources has made brackish water desalination a necessity in Oman. The application of capacitive deionization (CDI for the deionization of ground water samples from wells in Al-Musanaah Wilayat is proposed and demonstrated. A CDI cell is fabricated using nanoporous activated carbon cloth (ACC as the electrodes and is shown to be power efficient for desalting ground water samples with total dissolved solids (TDS of up to 4,000 mg/l. The CDI cell was able to remove up to 73% of the ionic scaling and fouling contaminants from brackish water samples. The power consumption for deionization of brackish water was estimated to be 1 kWh/m3 of desalinated water, which is much lower than the power required to process water with equivalent TDS by the reverse osmosis processes. The CDI process is elaborated, and observations and analysis of the ion adsorption characteristics and electrical properties of the capacitive cell are elucidated.

Ground based measurements of particulate emissions from supersonic transports. Concorde olympus engine

Energy Technology Data Exchange (ETDEWEB)

Whitefield, Ph D; Hagen, D E [Missouri Univ., Rolla, MO (United States). Cloud and Aerosol Sciences Lab.; Lilenfeld, H V [McDonnell Douglas Corp., St. Louis, MO (United States)

1998-12-31

The application of a mobile aerosol monitoring facility, the Mobile Aerosol Sampling System (MASS) is described to characterize engine aerosol emissions from the Rolls Royce Olympus Engine. The multi-configurational MASS has been employed in both ground and airborne field operations. It has been successfully flown on research aircrafts. In ground tests the MASS has participated in numerous jet engine related ground tests, and has been deployed to resolve aerosol generation problems in a high power chemical laser system. In all cases the measurements were made on samples taken from a harsh physical and chemical environment, with both high and low temperature and pressure, and in the presence of highly reactive gases. (R.P.) 9 refs.

Ground based measurements of particulate emissions from supersonic transports. Concorde olympus engine

Energy Technology Data Exchange (ETDEWEB)

Whitefield, Ph.D.; Hagen, D.E. [Missouri Univ., Rolla, MO (United States). Cloud and Aerosol Sciences Lab.; Lilenfeld, H.V. [McDonnell Douglas Corp., St. Louis, MO (United States)

1997-12-31

The application of a mobile aerosol monitoring facility, the Mobile Aerosol Sampling System (MASS) is described to characterize engine aerosol emissions from the Rolls Royce Olympus Engine. The multi-configurational MASS has been employed in both ground and airborne field operations. It has been successfully flown on research aircrafts. In ground tests the MASS has participated in numerous jet engine related ground tests, and has been deployed to resolve aerosol generation problems in a high power chemical laser system. In all cases the measurements were made on samples taken from a harsh physical and chemical environment, with both high and low temperature and pressure, and in the presence of highly reactive gases. (R.P.) 9 refs.

Effect of power frequency excitation character on ferroresonance in neutral-grounded system

International Nuclear Information System (INIS)

Hui Meng; Liu Chong-Xin

2010-01-01

In most earlier ferroresonance studies the traditional excitation characteristic of iron core, in which the traditional excitation characteristic contains harmonic voltages or currents, has been used as if it were made up of pure fundamental voltage or current. However, this is not always true. In comparison with traditional excitation characteristics, this paper introduces the power frequency excitation characteristic of the iron core, which contains no harmonics. The power frequency excitation characteristic of iron core has been obtained by Elector Magnetic Transient Program, resulting in discrete voltage and current pairs. Extensive simulations are carried out to analyse the effect of power frequency excitation characteristic on potential transformer ferroresonance. A detailed analysis of simulation results demonstrates that with power frequency excitation characteristic of iron core inclusion at certain excitation voltage the ferroresonance may happen, conversely it may not happen with traditional excitation characteristic inclusion. (general)

Aseismatic design and safety of nuclear power generation facilities. Research in Central Research Institute of Electric Power Industry

International Nuclear Information System (INIS)

1995-01-01

In order to contribute to the aseismatic design of nuclear power generation facilities, this Research Institute has carried out the observation on the site of buildings in Matsushiro earthquake, the experiment on a large vibration table, the vibration experiment on actual buildings and so on, thus made clear the method of evaluating the dynamic model of buildings and foundation grounds. Also it cooperated in the determination of input earthquake motion which is important for aseismatic design by carrying out the evaluation of the activity of faults the observation of strong earthquakes, and the elucidation and evaluation of the characteristics of earthquake motion. It has made the standard for evaluating the fault activity and the stability in earthquakes of the foundation and surrounding grounds of power stations. The development of new underground location technology, the location on Quaternary grounds and the location on the sea, and the research on developing the aseismatic construction of FBRs are in progress. The survey and evaluation of fault activities, the evaluation of earthquake input, the limit state design of important outdoor structures, the new location technology for nuclear power stations, and the development of the buckling and base isolation design of FBRs are reported. (K.I.)

Effects of space weather on high-latitude ground systems

Science.gov (United States)

Pirjola, Risto

Geomagnetically induced currents (GIC) in technological systems, such as power grids, pipelines, cables and railways, are a ground manifestation of space weather. The first GIC observations were already made in early telegraph equipment more than 150 years ago. In power networks, GIC may saturate transformers with possible harmful consequences extending even to a collapse of the whole system or to permanent damage of transformers. In pipelines, GIC and the associated pipe-to-soil voltages may enhance corrosion or disturb surveys associated with corrosion control. GIC are driven by the geoelectric field induced by a geomagnetic variation at the Earth’s surface. The electric and magnetic fields are primarily produced by ionospheric currents and secondarily affected by the ground conductivity. Of great importance is the auroral electrojet with other rapidly varying currents indicating that GIC are a particular high-latitude problem. In this paper, we summarize the GIC research done in Finland during about 25 years, and discuss the calculation of GIC in a given network. Special attention is paid to modelling a power system. It is shown that, when considering GIC at a site, it is usually sufficient to take account for a smaller grid in the vicinity of the particular site. Modelling GIC also provides a basis for developing forecasting and warning methods of GIC.

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.

Improved Power System of the Future

OpenAIRE

Rabinowitz, Mario

2003-01-01

This paper is intended to provide an insight into physics and engineering that can modernize electric power systems. Topics covered are Flexible ac transmission systems (FACTS), Custom Power, Greatly improved Capacitors, Electrical Insulation, Distribution Cables, Improved Polymeric Insulation, Underground Vault Explosions, Fault Location, Smart Cables, Neutral and Ground, Corrosion and Protection, Conventional Transformers, Compact Transformers, Ferroresonance, and Solid State Transformers.

Power and Signal Integrity and Electromagnetic Emission; the balancing act of decoupling, planes and tracks

NARCIS (Netherlands)

Leferink, Frank Bernardus Johannes

2007-01-01

The noise voltage in the reference or ground of a printed circuit board is often the cause of unwanted radiated emission. Power supply planes attribute to the noise voltage. By replacing the power supply planes by tracks, the noise voltage in the reference or ground can be considerably reduced,

Improvement of and Parameter Identification for the Bimodal Time-Varying Modified Kanai-Tajimi Power Spectral Model

Directory of Open Access Journals (Sweden)

Huiguo Chen

2017-01-01

Full Text Available Based on the Kanai-Tajimi power spectrum filtering method proposed by Du Xiuli et al., a genetic algorithm and a quadratic optimization identification technique are employed to improve the bimodal time-varying modified Kanai-Tajimi power spectral model and the parameter identification method proposed by Vlachos et al. Additionally, a method for modeling time-varying power spectrum parameters for ground motion is proposed. The 8244 Orion and Chi-Chi earthquake accelerograms are selected as examples for time-varying power spectral model parameter identification and ground motion simulations to verify the feasibility and effectiveness of the improved bimodal time-varying modified Kanai-Tajimi power spectral model. The results of this study provide important references for designing ground motion inputs for seismic analyses of major engineering structures.

Seismic resistance evaluation methods for foundation ground of nuclear power plant and for critical civil engineering structures

International Nuclear Information System (INIS)

1985-01-01

The Ground Integrity Subcommittee was established in September, 1979, in the Japan Society of Civil Engineers to systematize the relation among the survey, test, analysis, evaluation, design and construction of diverse geological features and grounds. The results were put in order in March, 1984. In this paper, the main results of examination by the Aseismatic Design Working Group consisted of three groups are reported. It was decided to evaluate the aseismatic capability of the foundation ground and surrounding slopes of reactor buildings and important outdoor structures so that the function of supporting buildings and installations is not impaired, and that influence is not exerted on the maintenance of the function of buildings and installations. The basic concept, design earthquake force and standard values for the evaluation of the aseismatic stability of the foundation ground and surrounding slopes of reactor buildings are described. The basic concept and the comparison of various methods of aseismatic calculation are reported regarding the evaluation of the aseismatic stability of important outdoor structures in civil engineering field. (Kako, I.)

Intelligent (Autonomous) Power Controller Development for Human Deep Space Exploration

Science.gov (United States)

Soeder, James; Raitano, Paul; McNelis, Anne

2016-01-01

As NASAs Evolvable Mars Campaign and other exploration initiatives continue to mature they have identified the need for more autonomous operations of the power system. For current human space operations such as the International Space Station, the paradigm is to perform the planning, operation and fault diagnosis from the ground. However, the dual problems of communication lag as well as limited communication bandwidth beyond GEO synchronous orbit, underscore the need to change the operation methodology for human operation in deep space. To address this need, for the past several years the Glenn Research Center has had an effort to develop an autonomous power controller for human deep space vehicles. This presentation discusses the present roadmap for deep space exploration along with a description of conceptual power system architecture for exploration modules. It then contrasts the present ground centric control and management architecture with limited autonomy on-board the spacecraft with an advanced autonomous power control system that features ground based monitoring with a spacecraft mission manager with autonomous control of all core systems, including power. It then presents a functional breakdown of the autonomous power control system and examines its operation in both normal and fault modes. Finally, it discusses progress made in the development of a real-time power system model and how it is being used to evaluate the performance of the controller and well as using it for verification of the overall operation.

Rupture dynamics and ground motions from earthquakes in 2-D heterogeneous media

KAUST Repository

Bydlon, Samuel A.

2015-03-21

©2015. American Geophysical Union. All Rights Reserved. We perform 2-D simulations of earthquakes on rough faults in media with random heterogeneities (with von Karman distribution) to study the effects of geometric and material heterogeneity on the rupture process and resulting high-frequency ground motions in the near-fault region (out to ∼20km). Variations in slip and rupture velocity can arise from material heterogeneity alone but are dominantly controlled by fault roughness. Scattering effects become appreciable beyond ∼3km from the fault. Near-fault scattering extends the duration of incoherent, high-frequency ground motions and, at least in our 2-D simulations, elevates root-mean-square accelerations (i.e., Arias intensity) with negligible reduction in peak velocities. We also demonstrate that near-fault scattering typically occurs in the power law tail of the power spectral density function, quantified by the Hurst exponent and another parameter combining standard deviation and correlation length. Key Points Fault roughness, not material heterogeneity, dominates rupture process Introduce parameter that can be used to quantify near-fault scattering Scattering affects the duration and amplitude of high-frequency ground motions

Ground water '89

International Nuclear Information System (INIS)

1989-01-01

The proceedings of the 5th biennial symposium of the Ground Water Division of the Geological Society of South Africa are presented. The theme of the symposium was ground water and mining. Papers were presented on the following topics: ground water resources; ground water contamination; chemical analyses of ground water and mining and its influece on ground water. Separate abstracts were prepared for 5 of the papers presented. The remaining papers were considered outside the subject scope of INIS

Technical guidelines for aseismic design of nuclear power plants

International Nuclear Information System (INIS)

Park, Y.J.; Hofmayer, C.H.

1994-06-01

This document is a translation, in its entirety, of the Japan Electric Association (JEA) publication entitled open-quotes Technical Guidelines for Aseismic Design of Nuclear Power Plants - JEAG 4601-1987.close quotes This guideline describes in detail the aseismic design techniques used in Japan for nuclear power plants. It contains chapters dealing with: (a)the selection of earthquake ground motions for a site, (b) the investigation of foundation and bedrock conditions, (c) the evaluation of ground stability and the effects of ground movement on buried piping and structures, (d) the analysis and design of structures, and (e) the analysis and design of equipment and distribution systems (piping, electrical raceways, instrumentation, tubing and HVAC duct). The guideline also includes appendices which summarize data, information and references related to aseismic design technology

Modeling of Optimal Power Generation using Multiple Kites

NARCIS (Netherlands)

Williams, P.; Lansdorp, B.; Ockels, W.J.

2008-01-01

Kite systems have the potential to revolutionize energy generation. Large scale systems are envisioned that can fly autonomously in “power generation” cycles which drive a ground-based generator. In order for such systems to produce power efficiently, good models of the system are required. This

Feasibility study on floating nuclear power station

International Nuclear Information System (INIS)

Kajima, Ryoichi

1987-01-01

It is stipulated that nuclear power plants are to be built on solid rock bases on land in Japan. However, there are a limited number of appropriate siting grounds. The Central Research Institute of Electric Power Industry has engaged since 1981 in the studies on the construction technology of power plants, aiming at establishing new siting technology to expand the possible siting areas for nuclear power plants. Underground siting is regarded as a proven technology due to the experience in underground hydroelectric power plants. The technology of siting on quaternary ground is now at the stage of verification. In this report, the outline of floating type offshore/inshore siting technology is introduced, which is considered to be feasible in view of the technical and economical aspects. Three fixed structure types were selected, of which the foundations are fixed to seabed, plant superstructures are above sea surface, and which are floating type. Aiming at ensuring the aseismatic stability of the plant foundations, the construction technology is studied, and the structural concept omitting buoyancy is possible. The most practical water depth is not more than 20 m. The overall plant design, earthquake isolation effect and breakwater are described. (Kako, I.)

Rf power systems for the national synchrotron light source

International Nuclear Information System (INIS)

Dickinson, T.; Rheaume, R.H.

1981-01-01

The booster synchrotron and the two storage rings at the NSLS are provided with rf power systems of 3 kW, 50 kW, and 500 kW nominal output power, all at 53 MHz. This power is supplied by grounded grid tetrode amplifiers designed for television broadcast service. These amplifiers and associated power supplies, control and interlock systems, rf controls, and computer interface are described

Conference on ground-mounted photovoltaic plants in France and in Germany

International Nuclear Information System (INIS)

Viertl, Cornelia; Argenlieu, Philippe d'; Masson, Gaetan; Schwan, Kurt; Thomas, Christophe; Hoffmann, Uta; Bohl, Johannes; Gossement, Arnaud; Jaclot, Emmanuel

2015-01-01

The French-German office for Renewable energies (OFAEnR) organised a conference on the future of ground-mounted photovoltaic plants both in France and Germany. In the framework of this French-German exchange of experience, about 130 participants debated about the present day and future regulatory framework and about the opportunities and challenges for projects financing and electricity resale. The different steps of plants realisation, from the planning to the site selection, the construction and the environmental issues were addressed as well. This document brings together the available presentations (slides) made during this event: 1 - Introduction of PV tendering within the context of a premium system (Cornelia Viertl); 2 - Ground-mounted solar plants - evolution of the Legal and Regulatory framework in France - New calls for tender (Philippe d'Argenlieu); 3 - Competitiveness of Utility-Scale PV (Gaetan Masson); 4 - Power production by ground-mounted PV systems for nearby industrial parks (Kurt Schwan); 5 - experience feedback of a direct selling operator and the future role of direct solar power selling (Christophe Thomas); 6 - Financing solar plants via crowd-funding - opportunities and challenges (Uta Hoffmann); 7 - The Planning and approval Process in Germany: Potential for Standardization and Optimization? (Johannes Bohl); 8 - Planning and approval Procedures in France: towards an harmonization between the different competent authorities and a reduction of the periods allowed for appeals? (Arnaud Gossement); 9 - EDF Energies Nouvelles: Solar plant of the Base of Toul-Rosieres. Decontamination and valorisation of polluted sites thanks to the construction of ground-mounted plants (Emmanuel Jaclot)

A thermal ground cloak

International Nuclear Information System (INIS)

Yang, Tianzhi; Wu, Qinghe; Xu, Weikai; Liu, Di; Huang, Lujun; Chen, Fei

2016-01-01

The thermal cloak has been a long-standing scientific dream of researchers and engineers. Recently thermal metamaterials with man-made micro-structure have been presented based on the principle of transformation optics (TO). This new concept has received considerable attention, which is a powerful tool for manipulating heat flux in thermal imaging systems. However, the inherent material singularity has long been a captivation of experimental realization. As an alternative method, the scattering-cancellation-based cloak (or bi-layer thermal cloak) has been presented to remove the singularity for achieving the same cloaking performance. Nevertheless, such strategy needs prerequisite knowledge (geometry and conductivity) of the object to be cloaked. In this paper, a new thermal ground cloak is presented to overcome the limitations. The device is designed, fabricated and measured to verify the thermal cloaking performance. We experimentally show that the remarkably low complexity of the device can fully and effectively be manipulated using realizable transformation thermal devices. More importantly, this thermal ground cloak is designed to exclude heat flux without knowing the information of the cloaked object. - Highlights: • We present the first thermal carpet cloak. • The carpet can thermally cloak any shaped object without knowing the properties of the object to be cloaked. • Excellent agreements between simulation and experiment are observed.

Transient evaluation using EMTP at one phase opening with the offsite power transformer for the emergency power supply systems of nuclear power plants. This report is a follow-up of the report published two years ago. Verification related to the open-phase detection method of the transformer by United States Electric Power Research Institute (EPRI)

International Nuclear Information System (INIS)

Shimada, Yoshio

2015-01-01

The emergency power supply systems of nuclear power plants, as the objects of this research, are critical in supplying stable electric power to such systems as the emergency core cooling system (ECCS), and in maintaining safety of the nuclear power reactor; this was apparent in the accident at the Fukushima Daiichi Nuclear Power Station. The USNRC issued regulatory documents (BL 2012-01, IN 2012-03), and has commenced evaluations on newly emerged vulnerability in the design of power supply systems which cannot be detected with degraded-voltage protection relays, with certain kinds of configuration of coils and iron core structures, such as when the offsite power supply side is a wye-connection and the load side is a delta-connection etc., when the detection of one-phase open fault with the circuit of a transformer which is without a ground fault connected to the offsite power supply system. The report in the INSS JOURNAL 2013 used simulation by the electro-magnetic transients program (EMTP) and clearly described the response at the time of the power supply side one-phase open without ground fault for various configuration of coils and various iron core structures of the three-phase transformer, and identified the important issues in the response of emergency power supply systems and the safety related components of representative domestic PWR plants when the one-phase open fault occurred without ground fault. The report in the INSS JOURNAL 2014 summarizes the previous results, and then presents the principles by which normal voltages are maintained in both the primary and the secondary sides when the one-phase open failure without ground fault occurs on the primary side of the transformer, and the results of the simulations of operations of the protection relays of the emergency power supply systems and the safety related components of representative a domestic PWR plant with EMTP. In a continuation of the previous reports, this report explains the method to detect

Wind power plant

Energy Technology Data Exchange (ETDEWEB)

Kling, A

1977-01-13

The wind power plant described has at least one rotor which is coupled to an electricity generator. The systems are fixed to a suspended body so that it is possible to set up the wind power plant at greater height where one can expect stronger and more uniform winds. The anchoring on the ground or on a floating body is done by mooring cables which can simultaneously have the function of an electric cable. The whole system can be steered by fins. The rotor system itself consists of at least one pair of contrarotating, momentum balanced rotors.

Air and ground resonance of helicopters with elastically tailored composite rotor blades

Science.gov (United States)

Smith, Edward C.; Chopra, Inderjit

1993-01-01

The aeromechanical stability, including air resonance in hover, air resonance in forward flight, and ground resonance, of a helicopter with elastically tailored composite rotor blades is investigated. Five soft-inplane hingeless rotor configurations, featuring elastic pitch-lag, pitch-flap and extension-torsion couplings, are analyzed. Elastic couplings introduced through tailored composite blade spars can have a powerful effect on both air and ground resonance behavior. Elastic pitch-flap couplings (positive and negative) strongly affect body, rotor and dynamic inflow modes. Air resonance stability is diminished by elastic pitch-flap couplings in hover and forwrad flight. Negative pitch-lag elastic coupling has a stabilizing effect on the regressive lag mode in hover and forward flight. The negative pitch-lag coupling has a detrimental effect on ground resonance stability. Extension-torsion elastic coupling (blade pitch decreases due to tension) decreases regressive lag mode stability in both airborne and ground contact conditions. Increasing thrust levels has a beneficial influence on ground resonance stability for rotors with pitch-flap and extension-torsion coupling and is only marginally effective in improving stability of rotors with pitch-lag coupling.

Gaussian Plume Model Parameters for Ground-Level and Elevated Sources Derived from the Atmospheric Diffusion Equation in the Neutral and Stable Conditions

International Nuclear Information System (INIS)

Essa, K.S.M.

2009-01-01

The analytical solution of the atmospheric diffusion equation for a point source gives the ground-level concentration profiles. It depends on the wind speed ua nd vertical dispersion coefficient σ z expressed by Pasquill power laws. Both σ z and u are functions of downwind distance, stability and source elevation, while for the ground-level emission u is constant. In the neutral and stable conditions, the Gaussian plume model and finite difference numerical methods with wind speed in power law and the vertical dispersion coefficient in exponential law are estimated. This work shows that the estimated ground-level concentrations of the Gaussian model for high-level source and numerical finite difference method are very match fit to the observed ground-level concentrations of the Gaussian model

Program plan for the Brayton Isotope Power System. Phase I. Design, fabrication and test of the Brayton Isotope Power System

International Nuclear Information System (INIS)

1975-01-01

Phase I of an overall program for the development of a 500 to 2000 W(e) (EOM), 7-y life, power system for space vehicles is discussed. The system uses a closed Brayton dynamic system to convert energy from an isotope heat source at a net efficiency greater than 25 percent. This first phase, a 35-month effort, is for the conceptual design of a 1300 W(e), 450 lb flight system and the design, fabrication, and test of a ground demonstration system. The flight system will use, for the baseline design, two of the multihundred-watt (MHW) heat sources being developed. The Ground Demonstration System will simulate, as closely as possible, the Brayton Isotope Power Flight System and will utilize components and technology being developed for the Mini-Brayton rotating unit, recuperator and heat source assembly, respectively. The Ground Demonstration System includes a performance test and a 1000-h endurance test

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.

Effect of Different Ground Scenarios on Flow Structure of a Rotor At Hover Condition

Science.gov (United States)

Kocak, Goktug; Nalbantoglu, Volkan; Yavuz, Mehmet Metin

2017-11-01

The ground effect of a scaled model rotor at hover condition was investigated experimentally in a confined environment. Different ground effect scenarios including full, partial, and inclined conditions, compared to out of ground condition, were characterized qualitatively and quantitatively using laser illuminated smoke visualization and Laser Doppler Anemometry measurements. The results indicate that the presence of the ground affects the flow regime near the blade tip by changing the spatial extent and the path of the vortex core. After the impingement of the wake to the ground, highly unsteady and turbulent wake is observed. Both the mean and the root mean square of the induced velocity increase toward the blade tip. In line with this, the spectral power of the dominant frequency in the velocity fluctuations significantly increases toward the blade tip. All these observations are witnessed in all ground effect conditions tested in the present study. Considering the inclined ground effect in particular, it is observed that the mean induced velocities of the high side (mountain) are higher compared to the velocities of the low side (valley) in contrast to the general trend observed in the present study where the ground effect reduces the induced velocity.

Measurement of magnetic fields in the direct proximity of power line conductors

International Nuclear Information System (INIS)

Mamishev, A.V.; Russell, B.D.

1995-01-01

Modeling and managing of power frequency magnetic fields requires verification of theory with actual measurements. Measurements only at ground level are not always sufficient for comprehensive studies. The technique and the results of three-dimensional mapping of the power frequency magnetic fields high above ground level are presented in this paper. Comparative calculations illustrate relevance and approximations of the existing theoretical approach to field modeling. The influence of harmonics on the elliptical rotation of the magnetic field vector is illustrated. The possibility of use of the magnetic fields for the power line proximity detection is discussed

Development on power distribution technologies of four electric power companies in Japan. The Tokyo Electric Power Co. , Inc

Energy Technology Data Exchange (ETDEWEB)

1989-07-01

Electric power companies have been needed to cope with various needs in accordance with the progress of highly information-oriented society, the improvement of industrial technology, and the advancement and diversification of the living environment. In such situation, the power distribution section of Tokyo Electric Power has promoted technical development, setting up following priority items to put into operation: to reduce power failure caused by works and accidents, to improve reliability in supply, to reduce costs of construction and all over business management, to serve customers to answer various needs, to develop new technology and new methods based on the medium- and long-term prospect, and so forth. Several examples of recent technical development are introduced here. They are as follows; compact equipment and materials for electric poles to match the circumstances of cities and to simplify the construction method for power distribution, a 750kVA large high-voltage power-generation truck to make provision against an emergency such as a disaster by a typhoon, a compact transformer used on the ground, a high-voltage automatic cabinet, and a detector to find the failure of indoor power distribution works in resistances in a short time. 8 figs.

Advantages of geosynchronous solar power satellites for terrestrial base-load electrical supply compared to other renewable energy sources - or why civilization needs solar power satellites

Energy Technology Data Exchange (ETDEWEB)

Strickland, J.K. Jr. [Texas Univ., Austin, TX (United States)

1998-06-01

The arguments in favour of using solar power satellites for primary base-load electrical supply are presented and compared with the advantages and drawbacks of other renewable energy sources, especially ground solar and wind systems. Popular misconceptions about energy use and the importation of space solar energy to the Earth`s surface are examined and discounted. Finally an optimal mix of space solar (focusing on geosynchronous solar power satellites), ground solar, and other energy sources is described which, it is argued, would be capable to meet future global energy demand. (UK)

Analysis of ground response data at Lotung large-scale soil- structure interaction experiment site

International Nuclear Information System (INIS)

Chang, C.Y.; Mok, C.M.; Power, M.S.

1991-12-01

The Electric Power Research Institute (EPRI), in cooperation with the Taiwan Power Company (TPC), constructed two models (1/4-scale and 1/2-scale) of a nuclear plant containment structure at a site in Lotung (Tang, 1987), a seismically active region in northeast Taiwan. The models were constructed to gather data for the evaluation and validation of soil-structure interaction (SSI) analysis methodologies. Extensive instrumentation was deployed to record both structural and ground responses at the site during earthquakes. The experiment is generally referred to as the Lotung Large-Scale Seismic Test (LSST). As part of the LSST, two downhole arrays were installed at the site to record ground motions at depths as well as at the ground surface. Structural response and ground response have been recorded for a number of earthquakes (i.e. a total of 18 earthquakes in the period of October 1985 through November 1986) at the LSST site since the completion of the installation of the downhole instruments in October 1985. These data include those from earthquakes having magnitudes ranging from M L 4.5 to M L 7.0 and epicentral distances range from 4.7 km to 77.7 km. Peak ground surface accelerations range from 0.03 g to 0.21 g for the horizontal component and from 0.01 g to 0.20 g for the vertical component. The objectives of the study were: (1) to obtain empirical data on variations of earthquake ground motion with depth; (2) to examine field evidence of nonlinear soil response due to earthquake shaking and to determine the degree of soil nonlinearity; (3) to assess the ability of ground response analysis techniques including techniques to approximate nonlinear soil response to estimate ground motions due to earthquake shaking; and (4) to analyze earth pressures recorded beneath the basemat and on the side wall of the 1/4 scale model structure during selected earthquakes

Space Theory and Strategy: War From the High Ground Down

Science.gov (United States)

2016-06-01

M.V. “COYOTE” SMITH (Date) __________________________________________ COLONEL TIMOTHY CULLEN (Date) iii...reader, Colonel Timothy Cullen , I would like to express my gratitude for the insightful suggestions to this work. To the ultimate sounding board... William L. Shelton, “Military Space: A Strategic Crossroad,” Air & Space Power Journal (September-October 2013): 5-6, War From the High Ground Down

GROUNDING THE REDUCTION OF POWER OF THE HYDRAULIC DRIVE ELECTRIC MOTOR BY EQUIVALENT POWER METHOD

Directory of Open Access Journals (Sweden)

O. Hrygorov

2017-06-01

Full Text Available The authors have analyzed the power consumption by a hydraulic drive and wound rotor motor of crane mechanisms at all stages of the operational cycle: acceleration, movement at nominal or intermediate speed and deceleration. The decrease of the rated capacity of electric motors is justified.

Predictors of Relationship Power among Drug-involved Women

OpenAIRE

Campbell, Aimee N. C.; Tross, Susan; Hu, Mei-chen; Pavlicova, Martina; Nunes, Edward V.

2012-01-01

Gender-based relationship power is frequently linked to women’s capacity to reduce sexual risk behaviors. This study offers an exploration of predictors of relationship power, as measured by the multidimensional and theoretically grounded Sexual Relationship Power Scale (SRPS), among women in outpatient substance abuse treatment. Linear models were used to test nine predictors (age, race/ethnicity, education, time in treatment, economic dependence, substance use, sexual concurrency, partner a...

Highly Reliable Transformerless Photovoltaic Inverters With Leakage Current and Pulsating Power Elimination

DEFF Research Database (Denmark)

Tang, Yi; Yao, Wenli; Loh, Poh Chiang

2016-01-01

This paper presents a transformerless inverter topology, which is capable of simultaneously solving leakage current and pulsating power issues in grid-connected photovoltaic (PV) systems. Without adding any additional components to the system, the leakage current caused by the PV-to-ground parasi......This paper presents a transformerless inverter topology, which is capable of simultaneously solving leakage current and pulsating power issues in grid-connected photovoltaic (PV) systems. Without adding any additional components to the system, the leakage current caused by the PV......-to-ground parasitic capacitance can be bypassed by introducing a common-mode (CM) conducting path to the inverter. The resulting ground leakage current is therefore well controlled to be below the regulation limit. Furthermore, the proposed inverter can also eliminate the well-known double-line-frequency pulsating...... power that is inherent in single-phase PV systems. By properly injecting CM voltages to the output filter capacitors, the pulsating power can be decoupled from the dc-link. Therefore, it is possible to use long-lifetime film capacitors instead of electrolytic capacitors to improve the reliability...

Correction of Beam Distortion in Negative Hydrogen Ion Source with Multi-Slot Grounded Grid

International Nuclear Information System (INIS)

Tsumori, Katsuyoshi; Kaneko, Osamu; Takeiri, Yasuhiko; Oka, Yoshihide; Osakabe, Masaki; Ikeda, Katsunori; Nagaoka, Kenichi; Kawamoto, Toshikazu; Asano, Eiji; Sato, Mamoru; Kondo, Tomoki; Watanabe, Junko; Asano, Shiro; Suzuki, Yasuo

2005-01-01

The new beam accelerator with multi-slot grounded grid (MSGG) has been developed to increase the port-through power into large helical device (LHD). Using the accelerator, the maximum power of 5.7 MW was achieved at the beam energy of 186 keV in the beam injection to LHD plasma last year. Although the port-through power increased compared with conventional accelerators with multi-hole grounded grid (MHGG), the accelerator with the MSGG includes a disadvantage of bi-focal condition in parallel and perpendicular direction to the long side of the slots. When the beam width in one of those directions gets narrower, the width in another direction becomes wider. This disadvantage includes the loss of beam port-through power and induces internal damages in neutral beam line. In order to reduce the disadvantage, an experiment has been done using a small-scaled negative ion source with racetrack-shaped apertures for the steering grid installed at beam upstream of the MSGG. By applying the racetrack apertures to the accelerator, it is observed that the beam widths in the parallel and perpendicular directions to the slot long side have almost the same focal condition to obtain minimal beam widths

Relativistic analysis of nuclear ground state densities at 135 to 200 ...

Indian Academy of Sciences (India)

fitting of differential cross-section and analyzing power, and the appearance of wine-bottle- ... So, the effect of different nuclear density distributions is quite conspicuous in the relativistic ap- proach. Hence, we have analyzed five different nuclear ground state .... The NEG and FNEG densities have been used to see the effect.

Nuclear power in India

International Nuclear Information System (INIS)

Bose, D.K.

1980-01-01

India has now nine years of experience with her in nuclear power generation. The system has been acclaimed on various grounds by the authority concerned with its organization in the country. The present paper intends to examine critically the claim for economic superiority of the nuclear power over the thermal power which is asserted often by the spokesmen for the former. Information about the cost of nuclear power that is available to researchers in India is very meagre. Whatever appears in official publications is hardly adequate for working out reasonable estimates for scrutiny. One is therefore left to depend on the public statements made by dignitaries from time to time to form an idea about the economics of nuclear power. Due to gaps in information we are constrained to rely on the foreign literature and make careful guesses about possible costs applicable to India

Traditional behaviour and fidelity to caribou calving grounds by barren-ground caribou

Directory of Open Access Journals (Sweden)

Anne Gunn

1986-06-01

Full Text Available Evidence for the fidelity of female barren-ground caribou (Rangifer tarandus spp. of each herd to specific calving grounds is convincing. Involvement of learned behaviour in the annual return of those cows to the same calving grounds implies such actions are a form of «traditional» behaviour. Even wide variations in population size have not yet knowingly led to marked changes in size or location of calving grounds or prolonged abandonment of established ones. Rarely is the adoption of new calving grounds reported and emigration to another herd's calving ground or interchange between calving grounds has not yet been unequivocally documented. The calving experience of individual caribou and environmental pressures may modify the cow's use patterns of her calving grounds. The current definition of herds based on traditional calving grounds may require modification, if increasing caribou numbers result in changes in traditions. However, current data do not contradict either the fidelity to traditional calving grounds or the concept of herd identity based on that fidelity.

Analysis of main dynamic parameters of split power transmission

Directory of Open Access Journals (Sweden)

A. Janulevičius

2008-06-01

Full Text Available The review carried out had shown one basic approach of split power transmission to the organization of drive which is applied to stepless transmissions of tractors and parallel hybrid cars. In the split power transmission the power split device uses a planetary gear. Tractor engine power in the split power transmission is transmitted to the drive shaft via a mechanical and hydraulic path. The theoretical analysis of main parameters of the split power transmission of the tractor is presented. The angular velocity of sun and coronary gears of the differential set is estimated by solution of the system of equations in which one equation is made for planetary differential gear, and another – for hydrostatic drive. The analysis of the transmission gear-ratio dependencies on the ratio of hydraulic machines capacities is carried out. Dependence of the variation of angular velocity of the coronary and the sun gears on the ground speed of the tractor is presented. Dependence of sum shaft torque and its constituents, carried by mechanical and hydraulic lines, on sum shaft angular velocity and ground speed of tractor and engine speed is also presented.

Accident of Large-scale Wind Turbines Disconnecting from Power Grid and Its Protection

Institute of Scientific and Technical Information of China (English)

2012-01-01

There were many accidents of large-scale wind turbines disconnecting from power grid in 2011. As single- phase-to-ground fault cannot be correctly detected, single-phase-to-ground fault evolved to phase-to-phase fault. Phase-to-phase fault was isolated slowly, thus leading to low voltage. And wind turbines without enough low voltage ride-through capacity had to be disconnected from the grid. After some wind turbines being disconnected from the grid, overvoltage caused by reactive power surplus made more wind turbines disconnect from the grid. Based on the accident analysis, this paper presents solutions to above problems, including travelling waves based single-phase-to-ground protection, adaptive low voltage protection, integrated protection and control, and high impedance fault detection. The solutions lay foundations in theory and technology to prevent large-scale wind turbines disconnecting from the operating power grid.

Sparking protection for MFTF-B Neutral Beam Power Supplies

International Nuclear Information System (INIS)

Cummings, D.B.

1983-01-01

This paper describes the upgrade of MFTF-B Neutral Beam Power Supplies for sparking protection. High performance ion sources spark repeatedly so ion source power supplies must be insensitive to sparking. The hot deck houses the series tetrode, arc and filament supplies, and controls. Hot deck shielding has been upgraded and a continuous shield around the arc, filament, gradient grid, and control cables now extends from the hot deck, through the core snubber, to the source. The shield carries accelerating current and connects only to the source. Shielded source cables go through an outer duct which now connects to a ground plane under the hot deck. This hybrid transmission line is a low inductance path for sparks discharging the stray capacitance of the hot deck and isolation transformers, reducing coupling to building steel. Parallel DC current return cables inside the duct lower inductance to reduce inductive turn-off transients. MOVs to ground further limit surges in the remote power supply return. Single point grounding is at the source. No control or rectifier components have been damaged nor are there any known malfunctions due to sparking up to 80 kV output

Sparking protection for MFTF-B neutral beam power supplies

International Nuclear Information System (INIS)

Cummings, D.B.

1983-01-01

This paper describes the upgrade of MFTF-B Neutral Beam Power Supplies for sparking protection. High performance ion sources spark repeatedly so ion source power supplies must be insensitive to sparking. The hot deck houses the series tetrode, arc and filament supplies, and controls. Hot deck shielding has been upgraded and a continuous shield around the arc, filament, gradient grid, and control cables now extends from the hot deck, through the core snubber, to the source. The shield carries accelerating current and connects only to the source. Shielded source cables go through an outer duct which now connects to a ground plane under the hot deck. This hybrid transmission line is a low inductance path for sparks discharging the stray capacitance of the hot deck and isolation transformers, reducing coupling to building steel. Parallel dc current return cables inside the duct lower inductance to reduce inductive turn-off transients. MOVs to ground further limit surges in the remote power supply return. Single point grounding is at the source. No control or rectifier components have been damaged nor are there any known malfunctions due to sparking up to 80 kV output

Study on dynamic behavior of large-scale foundation on soft ground, (6)

International Nuclear Information System (INIS)

Sawada, Yoshihiro; Yajima, Hiroshi; Esashi, Yasuyuki; Sakurai, Akio

1983-01-01

Generally, the earthquake motion in the basements of buildings and foundations shows smaller amplitude than that on ground surface. As the cause, there are two interpretations, the interaction of ground and structures and the input loss of earthquake motion due to the restriction by foundations. It is important to urgently clarify this problem in case of the aseismatic design of nuclear power stations at the location of Quaternary ground. For the purpose, the observation of earthquakes was performed with simple flat foundations and in the surrounding ground, in which the effect of locking and upper structures was negligible. The obtained data were compared with the theoretical solutions according to the above two interpretations, thus it was attempted to clarify the mechanism of restricting earthquake motion by foundations. The foundations were a foundation of 30 cm diameter and 2 cm thickness made by improving the superweak ground with nearly zero N-value by cement mixing treatment and a large concrete base of 90 x 45 x 21 m constructed in sandy gravellayer. The mecahnism of restricting vibration was due to the reflection effect of input energy at the boundary between rigid bases and the soft ground right under them, and it can be estimated by multiple reflection theory. (Kako, I.)

Photovoltaic electric power applied to Unmanned Aerial Vehicles (UAV)

Science.gov (United States)

Geis, Jack; Arnold, Jack H.

1994-09-01

Photovoltaic electric-powered flight is receiving a great deal of attention in the context of the United States' Unmanned Aerial Vehicle (UAV) program. This paper addresses some of the enabling technical areas and their potential solutions. Of particular interest are the long-duration, high-altitude class of UAV's whose mission it is to achieve altitudes between 60,000 and 100,000 feet, and to remain at those altitudes for prolonged periods performing various mapping and surveillance activities. Addressed herein are studies which reveal the need for extremely light-weight and efficient solar cells, high-efficiency electric motor-driven propeller modules, and power management and distribution control elements. Since the potential payloads vary dramatically in their power consumption and duty cycles, a typical load profile has been selected to provide commonality for the propulsion power comparisons. Since missions vary widely with respect to ground coverage requirements, from repeated orbiting over a localized target to long-distance routes over irregular terrain, we have also averaged the power requirements for on-board guidance and control power, as well as ground control and communication link utilization. In the context of the national technology reinvestment program, wherever possible we modeled components and materials which have been qualified for space and defense applications, yet are compatible with civilian UAV activities. These include, but are not limited to, solar cell developments, electric storage technology for diurnal operation, local and ground communications, power management and distribution, and control servo design. And finally, the results of tests conducted by Wright Laboratory on ultralight, highly efficient MOCVD GaAs solar cells purchased from EPI Materials Ltd. (EML) of the UK are presented. These cells were also used for modeling the flight characteristics of UAV aircraft.

Photovoltaic electric power applied to Unmanned Aerial Vehicles (UAV)

Science.gov (United States)

Geis, Jack; Arnold, Jack H.

1994-01-01

Photovoltaic electric-powered flight is receiving a great deal of attention in the context of the United States' Unmanned Aerial Vehicle (UAV) program. This paper addresses some of the enabling technical areas and their potential solutions. Of particular interest are the long-duration, high-altitude class of UAV's whose mission it is to achieve altitudes between 60,000 and 100,000 feet, and to remain at those altitudes for prolonged periods performing various mapping and surveillance activities. Addressed herein are studies which reveal the need for extremely light-weight and efficient solar cells, high-efficiency electric motor-driven propeller modules, and power management and distribution control elements. Since the potential payloads vary dramatically in their power consumption and duty cycles, a typical load profile has been selected to provide commonality for the propulsion power comparisons. Since missions vary widely with respect to ground coverage requirements, from repeated orbiting over a localized target to long-distance routes over irregular terrain, we have also averaged the power requirements for on-board guidance and control power, as well as ground control and communication link utilization. In the context of the national technology reinvestment program, wherever possible we modeled components and materials which have been qualified for space and defense applications, yet are compatible with civilian UAV activities. These include, but are not limited to, solar cell developments, electric storage technology for diurnal operation, local and ground communications, power management and distribution, and control servo design. And finally, the results of tests conducted by Wright Laboratory on ultralight, highly efficient MOCVD GaAs solar cells purchased from EPI Materials Ltd. (EML) of the UK are presented. These cells were also used for modeling the flight characteristics of UAV aircraft.

Methods for prediction of strong earthquake ground motion. Final technical report, October 1, 1976--September 30, 1977

International Nuclear Information System (INIS)

Trifunac, M.D.

1977-09-01

The purpose of this report is to summarize the results of the work on characterization of strong earthquake ground motion. The objective of this effort has been to initiate presentation of simple yet detailed methodology for characterization of strong earthquake ground motion for use in licensing and evaluation of operating Nuclear Power Plants. This report will emphasize the simplicity of the methodology by presenting only the end results in a format that may be useful for the development of the site specific criteria in seismic risk analysis, for work on the development of modern standards and regulatory guides, and for re-evaluation of the existing power plant sites

RF System description for the ground test accelerator radio-frequency quadrupole

International Nuclear Information System (INIS)

Regan, A.H.; Brittain, D.; Rees, D.E.; Ziomek, D.

1992-01-01

This paper describes the RF system being used to provide RF power and to control the cavity field for the ground test accelerator (GTA) radio-frequency quadrupole (RFQ). The RF system consists of a low-level RF (LLRF) control system, and RF Reference generation subsystem, and a tetrode as a high-power amplifier (HPA) that can deliver up to 300 kW of peak power to the RFQ cavity at a 2% duty factor. The LLRF control system implements in-phase and quadrature (I and Q) control to maintain the cavity field within tolerances of 0.5% in amplitude and 0.5 degrees in phase in the presence of beam-induced instabilities

Point Climat no. 21 'Regional wind power plans: is there enough wind to reach the Grenelle wind power targets?'

International Nuclear Information System (INIS)

Bordier, Cecile; Charentenay, Jeremie de

2012-01-01

Among the publications of CDC Climat Research, 'Climate Briefs' presents, in a few pages, hot topics in climate change policy. This issue addresses the following points: Regional wind power plans assess the wind power development potential of every French region. The aggregate regional potential largely exceeds national targets for 2020. However, achieving these targets is still far from guaranteed: the forecasted potential is theoretical, and the issues involved in implementing wind power projects on the ground will likely reduce this potential

Nuclear power in space

International Nuclear Information System (INIS)

Anghaie, S.

2007-01-01

The development of space nuclear power and propulsion in the United States started in 1955 with the initiation of the ROVER project. The first step in the ROVER program was the KIWI project that included the development and testing of 8 non-flyable ultrahigh temperature nuclear test reactors during 1955-1964. The KIWI project was precursor to the PHOEBUS carbon-based fuel reactor project that resulted in ground testing of three high power reactors during 1965-1968 with the last reactor operated at 4,100 MW. During the same time period a parallel program was pursued to develop a nuclear thermal rocket based on cermet fuel technology. The third component of the ROVER program was the Nuclear Engine for Rocket Vehicle Applications (NERVA) that was initiated in 1961 with the primary goal of designing the first generation of nuclear rocket engine based on the KIWI project experience. The fourth component of the ROVER program was the Reactor In-Flight Test (RIFT) project that was intended to design, fabricate, and flight test a NERVA powered upper stage engine for the Saturn-class lunch vehicle. During the ROVER program era, the Unites States ventured in a comprehensive space nuclear program that included design and testing of several compact reactors and space suitable power conversion systems, and the development of a few light weight heat rejection systems. Contrary to its sister ROVER program, the space nuclear power program resulted in the first ever deployment and in-space operation of the nuclear powered SNAP-10A in 1965. The USSR space nuclear program started in early 70's and resulted in deployment of two 6 kWe TOPAZ reactors into space and ground testing of the prototype of a relatively small nuclear rocket engine in 1984. The US ambition for the development and deployment of space nuclear powered systems was resurrected in mid 1980's and intermittently continued to date with the initiation of several research programs that included the SP-100, Space Exploration

The 2011 Mineral, VA M5.8 Earthquake Ground Motions and Stress Drop: An Important Contribution to the NGA East Ground Motion Database

Science.gov (United States)

Cramer, C. H.; Kutliroff, J.; Dangkua, D.

2011-12-01

The M5.8 Mineral, Virginia earthquake of August 23, 2011 is the largest instrumentally recorded earthquake in eastern North America since the 1988 M5.9 Saguenay, Canada earthquake. Historically, a similar magnitude earthquake occurred on May 31, 1897 at 18:58 UCT in western Virginia west of Roanoke. Paleoseismic evidence for larger magnitude earthquakes has also been found in the central Virginia region. The Next Generation Attenuation (NGA) East project to develop new ground motion prediction equations for stable continental regions (SCRs), including eastern North America (ENA), is ongoing at the Pacific Earthquake Engineering Research Center funded by the U.S. Nuclear Regulatory Commission, the U.S. Geological Survey, the Electric Power Research Institute, and the U.S. Department of Energy. The available recordings from the M5.8 Virginia are being added to the NGA East ground motion database. Close in (less than 100 km) strong motion recordings are particularly interesting for both ground motion and stress drop estimates as most close-in broadband seismometers clipped on the mainshock. A preliminary estimate for earthquake corner frequency for the M5.8 Virginia earthquake of ~0.7 Hz has been obtained from a strong motion record 57 km from the mainshock epicenter. For a M5.8 earthquake this suggests a Brune stress drop of ~300 bars for the Virginia event. Very preliminary comparisons using accelerometer data suggest the ground motions from the M5.8 Virginia earthquake agree well with current ENA ground motion prediction equations (GMPEs) at short periods (PGA, 0.2 s) and are below the GMPEs at longer periods (1.0 s), which is the same relationship seen from other recent M5 ENA earthquakes. We will present observed versus GMPE ground motion comparisons for all the ground motion observations and stress drop estimates from strong motion recordings at distances less than 100 km. A review of the completed NGA East ENA ground motion database will also be provided.

Natural radioactivity of ground waters and soil in the vicinity of the ash repository of the coal-fired power plant ''Nikola Tesla'' A - Obrenovac (Yugoslavia)

International Nuclear Information System (INIS)

Vukovic, Z.; Mandic, M.; Vukovic, D.

1996-01-01

Radioactivity of U, Th and 40 K has been tested in the vicinity of the ash repository of coal-fired power plant ''Nikola Tesla'' A in Obrenovac (Yugoslavia). By using the methods of alpha and gamma spectrometry, as well as luminescence spectrophotometry, it has been found that the ash repository is a source of radionuclides of the uranium and thorium series and spreads direction of ground waters up to a distance of several hundred metres. The influence of the repository on the soil radioactivity has been found to be minimal, whereas the balance of the first members of series ( 238 U- 234 U- 230 Th; 232 Th- 228 Th) has not been disturbed. (Author)

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.

Mechanisms of power in participatory rural planning

DEFF Research Database (Denmark)

Johansen, Pia Heike; Chandler, Thomas Lund

2015-01-01

that in such an assessment of power it is needed also to drawn in the social context because different social contexts will be more or less vulnerable to different mechanisms of power. The paper takes the stand the rural settings are especially vulnerable to dis-engagement of local citizens, sub-ordination of the rural...... 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...

DC Distributed Power Systems. Analysis, Design and Control for a Renewable Energy System

Energy Technology Data Exchange (ETDEWEB)

Karlsson, Per

2002-12-01

source converters share the total load equally in per unit. The same DC distribution bus configuration is studied in a wind power application. Especially the dynamic properties of load-source interactions are highlighted. They are interesting since the sources are considered weak for a distributed power system. This is illustrated with simulations where the power is fed from wind turbines only and constant power loads are controlled at the same time as the DC bus voltage level. The wind power generators are modeled as permanent-magnet synchronous machines. The controller needed for the machines, including position estimation and field weakening, is discussed. To control the DC bus voltage, the available wind power must be higher than the power consumed by the loads and the excess power removed by pitch angle control. Pitch angle control is a comparably slow process and, therefore, the DC bus voltage controller must handle the transient power distribution. Personal safety and prevention of property damage are important factors of conventional AC power systems. For the investigated DC power system this is maybe even more important due to the fact that the star point of the sources and loads is left ungrounded or grounded through high impedance. The difficulty of detecting ground faults arises from the fact that the AC sources and loads are ungrounded or have high impedance to ground in order to effectively block zero-sequence currents flowing between the AC systems. A grounding scheme for the DC distribution system together with algorithms for detection of ground faults, are presented. The proposed method detects ground faults on both the AC and DC sides and is extended to cover short circuit faults with a minor work effort. Two schemes for high voltage interconnection of DC systems are studied. One of them provides galvanic isolation, which is an advantage since elevated voltage might appear in the DC systems otherwise, in the case of a ground fault in the high voltage

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

Ground Motion Prediction Trends For Eastern North America Based on the Next Generation Attenuation East Ground Motion Database

Science.gov (United States)

Cramer, C. H.; Kutliroff, J.; Dangkua, D.

2010-12-01

A five-year Next Generation Attenuation (NGA) East project to develop new ground motion prediction equations for stable continental regions (SCRs), including eastern North America (ENA), has begun at the Pacific Earthquake Engineering Research (PEER) Center funded by the Nuclear Regulatory Commission (NRC), the U.S. Geological Survey (USGS), the Electric Power Research Institute (EPRI), and the Department of Energy (DOE). The initial effort focused on database design and collection of appropriate M>4 ENA broadband and accelerograph records to populate the database. Ongoing work has focused on adding records from smaller ENA earthquakes and from other SCRs such as Europe, Australia, and India. Currently, over 6500 horizontal and vertical component records from 60 ENA earthquakes have been collected and prepared (instrument response removed, filtering to acceptable-signal band, determining peak and spectral parameter values, quality assurance, etc.) for the database. Geologic Survey of Canada (GSC) strong motion recordings, previously not available, have also been added to the NGA East database. The additional earthquakes increase the number of ground motion recordings in the 10 - 100 km range, particularly from the 2008 M5.2 Mt. Carmel, IL event, and the 2005 M4.7 Riviere du Loup and 2010 M5.0 Val des Bois earthquakes in Quebec, Canada. The goal is to complete the ENA database and make it available in 2011 followed by a SCR database in 2012. Comparisons of ground motion observations from four recent M5 ENA earthquakes with current ENA ground motion prediction equations (GMPEs) suggest that current GMPEs, as a group, reasonably agree with M5 observations at short periods, particularly at distances less than 200 km. However, at one second, current GMPEs over predict M5 ground motion observations. The 2001 M7.6 Bhuj, India, earthquake provides some constraint at large magnitudes, as geology and regional attenuation is analogous to ENA. Cramer and Kumar, 2003, have

Cost Study for Manufacturing of Solid Oxide Fuel Cell Power Systems

Energy Technology Data Exchange (ETDEWEB)

Weimar, Mark R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Chick, Lawrence A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Gotthold, David W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Whyatt, Greg A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2013-09-30

Solid oxide fuel cell (SOFC) power systems can be designed to produce electricity from fossil fuels at extremely high net efficiencies, approaching 70%. However, in order to penetrate commercial markets to an extent that significantly impacts world fuel consumption, their cost will need to be competitive with alternative generating systems, such as gas turbines. This report discusses a cost model developed at PNNL to estimate the manufacturing cost of SOFC power systems sized for ground-based distributed generation. The power system design was developed at PNNL in a study on the feasibility of using SOFC power systems on more electric aircraft to replace the main engine-mounted electrical generators [Whyatt and Chick, 2012]. We chose to study that design because the projected efficiency was high (70%) and the generating capacity was suitable for ground-based distributed generation (270 kW).

Optimization and Feasibility Analysis of Satellite Earth Station Power System Using Homer

Directory of Open Access Journals (Sweden)

Hassen T. Dorrah

2012-06-01

Full Text Available Satellite earth stations which located in remote areas are one of many applications powered by the renewable energy sources. Ground system consists of ground station and control centers working together to support the spacecraft and the data user. Earth station consists of major subsystems, transmitter, receiver, antenna, tracking equipment, terrestrial interface equipment and power supply. Power subsystem is an important part that required for supplying the earth station with electrical power to continue communicating with its remote sensing satellite. This paper deals with simulation and optimal sizing of earth station power system using HOMER software. A combination of two energy sources (solar, and wind to provide a continuous electric power production is used to determine the optimum system operation. Three system configurations are compared with respect to the total net present cost (NPC and levelized cost of energy (COE. Also, economical study will be analyzed for energy demand and sensitivity analysis will be performed.

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

Effect of Footwear Modifications on Oscillations at the Achilles Tendon during Running on a Treadmill and Over Ground: A Cross-Sectional Study.

Directory of Open Access Journals (Sweden)

Ilka Meinert

Full Text Available Achilles tendon injuries are known to commonly occur in runners. During running repeated impacts are transferred in axial direction along the lower leg, therefore possibly affecting the oscillation behavior of the Achilles tendon. The purpose of the present study was to explore the effects of different footwear modifications and different ground conditions (over ground versus treadmill on oscillations at the Achilles tendon.Oscillations were measured in 20 male runners using two tri-axial accelerometers. Participants ran in three different shoe types on a treadmill and over ground. Data analysis was limited to stance phase and performed in time and frequency space. Statistical comparison was conducted between oscillations in vertical and horizontal direction, between running shoes and between ground conditions (treadmill versus over ground running.Differences in the oscillation behavior could be detected between measurement directions with peak accelerations in the vertical being lower than those in the horizontal direction, p < 0.01. Peak accelerations occurred earlier at the distal accelerometer than at the proximal one, p < 0.01. Average normalized power differed between running shoes (p < 0.01 with harder damping material resulting in higher power values. Little to no power attenuation was found between the two accelerometers. Oscillation behavior of the Achilles tendon is not influenced by ground condition.Differences in shoe configurations may lead to variations in running technique and impact forces and therefore result in alterations of the vibration behavior at the Achilles tendon. The absence of power attenuation may have been caused by either a short distance between the two accelerometers or high stiffness of the tendon. High stiffness of the tendon will lead to complete transmission of the signal along the Achilles tendon and therefore no attenuation occurs.

Identification of strong earthquake ground motion by using pattern recognition

International Nuclear Information System (INIS)

Suzuki, Kohei; Tozawa, Shoji; Temmyo, Yoshiharu.

1983-01-01

The method of grasping adequately the technological features of complex waveform of earthquake ground motion and utilizing them as the input to structural systems has been proposed by many researchers, and the method of making artificial earthquake waves to be used for the aseismatic design of nuclear facilities has not been established in the unified form. In this research, earthquake ground motion was treated as an irregular process with unsteady amplitude and frequency, and the running power spectral density was expressed as a dark and light image on a plane of the orthogonal coordinate system with both time and frequency axes. The method of classifying this image into a number of technologically important categories by pattern recognition was proposed. This method is based on the concept called compound similarity method in the image technology, entirely different from voice diagnosis, and it has the feature that the result of identification can be quantitatively evaluated by the analysis of correlation of spatial images. Next, the standard pattern model of the simulated running power spectral density corresponding to the representative classification categories was proposed. Finally, the method of making unsteady simulated earthquake motion was shown. (Kako, I.)

Evaluation of seismic stability of nuclear power plants on weathered soft rocks

International Nuclear Information System (INIS)

Ogata, Nobuhide; Nishi, Koichi; Honsho, Shizumitsu

1991-01-01

Soft rocks such as weathered rocks or low cemented sedimentary rocks spread all over the country. If it is possible to construct nuclear power plants on such soft rocks, there will be more available sites for nuclear power plants. The investigation on the following research items was carried out. (1) Geological survey and the application of test methods on soft rocks. (2) Methods and application of laboratory and in-situ tests on soft rocks. (3) Response analysis of a reactor building and foundation ground during earthquake. (4) Stability analysis of soft rock ground as the foundation of a nuclear power plant regarding both earthquake and long-term settlement. From the results of the investigation, it became evident that the seismic stability of a nuclear power plant on weathered soft rocks can be assured enough. (author)

Isotope Brayton ground demonstration testing and flight qualification. Volume 1. Technical program

Energy Technology Data Exchange (ETDEWEB)

1974-12-09

A program is proposed for the ground demonstration, development, and flight qualification of a radioisotope nuclear heated dynamic power system for use on space missions beginning in the 1980's. This type of electrical power system is based upon and combines two aerospace technologies currently under intense development; namely, the MHW isotope heat source and the closed Brayton cycle gas turbine. This power system represents the next generation of reliable, efficient economic electrical power equipment for space, and will be capable of providing 0.5 to 2.0 kW of electric power to a wide variety of spacecraft for earth orbital and interplanetary missions. The immediate design will be based upon the requirements for the Air Force SURVSATCOM mission. The proposal is presented in three volumes plus an Executive Summary. This volume describes the tasks in the technical program.

Fault analysis and strategy of high pulsed power supply for high power laser

International Nuclear Information System (INIS)

Liu Kefu; Qin Shihong; Li Jin; Pan Yuan; Yao Zonggan; Zheng Wanguo; Guo Liangfu; Zhou Peizhang; Li Yizheng; Chen Dehuai

2001-01-01

according to the requirements of driving flash-lamp, a high pulsed power supply (PPS) based on capacitors as energy storage elements is designed. The author analyzes in detail the faults of high pulsed power supply for high power laser. Such as capacitor internal short-circuit, main bus breakdown to ground, flashlamp sudden short or break. The fault current and voltage waveforms were given by circuit simulations. Based on the analysis and computation, the protection strategy with the fast fuse and ZnO was put forward, which can reduce the damage of PPS to the lower extent and provide the personnel safe and collateral property from the all threats. The preliminary experiments demonstrated that the design of the PPS can satisfy the project requirements

GROUNDED THEORY METHODOLOGY and GROUNDED THEORY RESEARCH in TURKEY

OpenAIRE

ARIK, Ferhat; ARIK, Işıl Avşar

2016-01-01

This research discusses the historical development of the Grounded Theory Methodology, which is one of the qualitative research method, its transformation over time and how it is used as a methodology in Turkey. The Grounded Theory which was founded by Strauss and Glaser, is a qualitative methodology based on inductive logic to discover theories in contrast with the deductive understanding which is based on testing an existing theory in sociology. It is possible to examine the Grounded Theory...

Proceedings of the American Power Conference. Volume 58-II

International Nuclear Information System (INIS)

McBride, A.E.

1996-01-01

This book is part 2 of the proceedings of the American Power Conference, Technology for Competition and Globalization, 1996. The topics of the papers include structural plant design; challenges of the global marketplace; thermal hydraulic methods for nuclear power plant safety and operation; decontamination and decommissioning; competitive operations and maintenance; fuel opportunities; cooling; competitive power pricing; operations; transformers; relays; plant controls; training to meet the competitive future; burning technologies; ash and byproducts utilization; advanced systems; computer tools for plant design; globalization of power; power system protection and power quality; life extension; grounding; and transmission line equipment

Appeal in nuclear power proceedings dismissed on the grounds of expiration of the period for lodging an appeal

International Nuclear Information System (INIS)

Anon.

1981-01-01

In its decision of November 18, 1980 - No. 22 B 80 a 796 - the Administrative Court of Bavaria dismissed the appeal lodged against the dismissal of the Administrative Court of Regensburg handed down on March 19, 1980. The complainants had filed a declaratory action concerning the nullity of the licence granted for the Niederaischbach reactor, and for the Isar reactor at Ohu. Their actions were dismissed with costs on the grounds of lacking interest in the declaration - the complainants live a few hundred kilometers away from the sites of the nuclear power plants. The decision of the Administrative Court of Bavaria is based on the fact that the period for lodging appeals had expired. (Exept for the changed decision on costs) the decision of the Administrative Court of Regensburg has become final. The value in litigation of a declaratory action of nullity filed by a private person who denounces the violation of his basic right to life and to inviolability of his person is generally to be assessed at DM 10.000. In case of several complaints filed by different complainants, the subject value of the individual complaints are to be added according to Sect. 5 of the Code of Civil Procedure (ZPO). (orig./HSCH) [de

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.

Seismic effects on nuclear power plants

International Nuclear Information System (INIS)

Borea, A.L.; Meek, J.L.

1973-01-01

This paper sets out to discuss the problems related to the design of the nuclear power plant structure for transient loads that may be experienced from ground motions. It recognizes that ground motion may be experienced from several sources such as nearby explosion, forced vibration, from machinery or from an earthquake. In the first instance of an explosion, there is a need to study the basic wave propagation problem and to obtain expressions for ground motion and acceleration at a distance from the disturbing force. In this the importance of foundation material is stressed. The natural phenomena of the earthquake is also considered. Features associated with attempts to define a suitable basic earthquake - its magnitude, its probability of occurrence, etc. are discussed. Speculation is made as to the probability of earthquake in Australia. The end product of all such investigation is the study of the power plant structures themselves, under the influence of the dynamic forces. This may be undertaken on the crude basis of spectral analysis or by more refined finite element models using a specified earthquake as input. Here emphasis is placed on necessity to include the interaction between foundation and structure as well as accurate modelling of the structure itself. (author)

Green Applications for Space Power Project

Science.gov (United States)

Robinson, Joel (Principal Investigator)

2014-01-01

Spacecraft propulsion and power for many decades has relied on Hydrazine monopropellant technology for auxiliary power units (APU), orbital circularization, orbit raising/lowering and attitude control. However, Hydrazine is toxic and therefore requires special ground handling procedures to ensure launch crew safety. The Swedish Company ECAPS has developed a technology based upon the propellant Ammonium Dinitramide (ADN) that offers higher performance, higher density and reduced ground handling support than Hydrazine. This blended propellant is called LMP-103S. Currently, the United States Air Force (USAF) is pursuing a technology based on Hydroxyl Ammonium Nitrate (HAN, otherwise known as AF-M315E) with industry partners Aerojet and Moog. Based on the advantages offered by these propellants, MSFC should explore powering APU's with these propellants. Due to the availability of space hardware, the principal investigator has found a collection of USAF hardware, that will act as a surrogate, which operates on a Hydrazine derivative. The F-16 fighter jet uses H-70 or 30% diluted Hydrazine for an Emergency Power Unit (EPU) which supplies power to the plane. The PI has acquired two EPU's from planes slated for destruction at the Davis Monthan AFB. This CIF will include a partnership with 2 other NASA Centers who are individually seeking seed funds from their respective organizations: Kennedy Space Center (KSC) and Dryden Flight Research Center (DFRC). KSC is preparing for future flights from their launch pads that will utilize green propellants and desire a low-cost testbed in which to test and calibrate new leak detection sensors. DFRC has access to F-16's which can be used by MSFC & KSC to perform a ground test that demonstrates emergency power supplied to the jet. Neither of the green propellant alternatives have been considered nor evaluated for an APU application. Work has already been accomplished to characterize and obtain the properties of these 2 propellants

Brayton cycle space power systems

International Nuclear Information System (INIS)

Pietsch, A.; Trimble, S.W.; Harper, A.D.

1985-01-01

The latest accomplishments in the design and development of the Brayton Isotope Power System (BIPS) for space applications are described, together with a reexamination of the design/cost tradeoffs with respect to current economic parameters and technology status. The results of tests performed on a ground test version of the flight configuration, the workhorse loop, were used to confirm the performance projections made for the flight system. The results of cost-model analysis indicate that the use of the highest attainable power conversion system efficiency will yield the most cost-effective systems. 13 references

Development of a PC-based ground support system for a small satellite instrument

Science.gov (United States)

Deschambault, Robert L.; Gregory, Philip R.; Spenler, Stephen; Whalen, Brian A.

1993-11-01

The importance of effective ground support for the remote control and data retrieval of a satellite instrument cannot be understated. Problems with ground support may include the need to base personnel at a ground tracking station for extended periods, and the delay between the instrument observation and the processing of the data by the science team. Flexible solutions to such problems in the case of small satellite systems are provided by using low-cost, powerful personal computers and off-the-shelf software for data acquisition and processing, and by using Internet as a communication pathway to enable scientists to view and manipulate satellite data in real time at any ground location. The personal computer based ground support system is illustrated for the case of the cold plasma analyzer flown on the Freja satellite. Commercial software was used as building blocks for writing the ground support equipment software. Several levels of hardware support, including unit tests and development, functional tests, and integration were provided by portable and desktop personal computers. Satellite stations in Saskatchewan and Sweden were linked to the science team via phone lines and Internet, which provided remote control through a central point. These successful strategies will be used on future small satellite space programs.

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.

Validation of Sodar Measurements for Wind Power

DEFF Research Database (Denmark)

Hansen, Kurt Schaldemose

2006-01-01

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......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...... 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...

Fault Analysis of ITER Coil Power Supply System

International Nuclear Information System (INIS)

Song, In Ho; Jun, Tao; Benfatto, Ivone

2009-01-01

The ITER magnet coils are all designed using superconductors with high current carrying capability. The Toroidal Field (TF) coils operate in a steadystate mode with a current of 68 kA and discharge the stored energy in case of quench with using 9 interleaved Fast Discharge Units (FDUs). The Central Solenoid (CS) coils and Poloidal Field (PF) coils operate in a pulse mode with currents of up to 45 kA and require fast variation of currents inducing more than 10 kV during normal operation on the coil terminals using Switching Network (SN) systems (CSs, PF1 and 6) and Booster and VS converters (PF2 to 5), which are series connected to Main converters. SN and FDU systems comprise high current DC circuit breakers and resistors for generating high voltage (SN) and to dissipate magnetic energy (FDUs). High transient voltages can arise due to the switching operation of SN and FD and the characteristics of resistors and stray components of DC distribution systems. Also, faults in power supply control such as shorts or grounding faults can produce higher voltages between terminals and between terminal and ground. Therefore, the design of the coil insulation, coil terminal regions, feeders, feed throughs, pipe breaks and instrumentation must take account of these high voltages during normal and abnormal conditions. Voltage insulation level can be defined and it is necessary to test the coils at higher voltages, to be sure of reliable performance during the lifetime of operation. This paper describes the fault analysis of the TF, CS and PF coil power supply systems, taking account of the stray parameter of the power supply and switching systems and inductively coupled superconducting coil models. Resistor grounding systems are included in the simulation model and all fault conditions such as converter hardware and software faults, switching system hardware and software faults, DC short circuits and single grounding faults are simulated. The occurrence of two successive faults

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.

Generation of floor response spectra for a model structure of nuclear power plant

International Nuclear Information System (INIS)

Vaidyanathan, C.V.; Kamatchi, P.; Ravichandran, R.; Lakshmanan, N.

2003-01-01

The importance of Nuclear power plants and the consequences of a nuclear accident require that the nuclear structures be designed for the most severe environmental conditions. Earthquakes constitutes major design consideration for the system, structures and equipment of a nuclear power plant. The design of structures on ground is based on the ground response spectra. Many important parts of a nuclear power plant facility are attached to the principal parts of the structure and respond in a manner determined by the structural response rather than by the general ground motion to which the structure is supported. Hence the seismic response of equipment is generally based on the response spectrum of the floor on which it is mounted. In this paper such floor response spectra have been generated at different nodes of a chosen model structure of a nuclear power plant. In the present study a detailed nonlinear time history analysis has been carried out on the mathematical model of the chosen Nuclear Power Plant model structure with the spectrum compatible time history. The acceleration response results of the time history analysis has been used in the spectral analysis and the response spectra are generated. Further peak broadening has been done to account for uncertainties in the material properties and soil characteristics. (author)

Transformerless photovoltaic inverters with leakage current and pulsating power elimination

DEFF Research Database (Denmark)

Tang, Yi; Yao, Wenli; Wang, H.

2015-01-01

This paper presents a transformerless inverter topology, which is capable of simultaneously solving leakage current and pulsating power issues in grid-connected photovoltaic (PV) systems. Without adding any additional components to the system, the leakage current caused by the PV......-to-ground parasitic capacitance can be bypassed by introducing a common mode (CM) conducting path to the inverter. The resulting ground leakage current is therefore well controlled to be below the regulation limit. Moreover, the proposed inverter can also eliminate the well-known double line frequency pulsating power....... The mechanism of leakage current suppression and the closed-loop control of pulsating power decoupling are discussed in the paper in details. A 500 W prototype was also built and tested in the laboratory, and both simulation and experimental results are finally presented to show the excellent performance...

Nuclear power: Hour of fog producers

International Nuclear Information System (INIS)

Rauner, M.; Schuh, H.

2004-01-01

Seven advanced nuclear power plants in Germany can withstand a frontal crash by a full-tanked Jumbo-Jet. But for five older plants even smaller planes can cause an hazard impossible to control. A fog generation around the power plants, favorized by operators and politicians, to camouflage this plants against terroristic flights is absurd because of the possibility of flight automation. However terrorists may attack reactors also from the ground, but how they can do is top secret. (GL) [de

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 blocking...... IGBT's (RB-IGBT) and two MOSFET's), a capacitor and a small filter at the output stage. The proposed topology share a common ground with the grid and the PV source. A Unipolar Sinusoidal Pulse-Width Modulation (SPWM) technique is used to modulate the inverter to minimize switching loss, output current...

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.

Grounding-Induced Sectional Forces and Residual Strength of Grounded Ship Hulls

DEFF Research Database (Denmark)

Paik, Jeom Kee; Pedersen, Preben Terndrup

1996-01-01

The aim of the present study is to determine the sectional forces induced by ship grounding and also to assess the residual strength of groundedship hulls. An analytical approach is used to estimate the grounding-induced sectional forces of ships. The extent and location of structural damage due...... to grounding is defined based on the ABS Safe Hull guide. The residual strength of damaged hulls is calculated by using a simple analytical formula. The method is applied to residual strength assessment of a damaged double hull tanker of 38,400 dwt due to grounding....

Constructivist Grounded Theory?

Directory of Open Access Journals (Sweden)

Barney G. Glaser, PhD, Hon. PhD

2012-06-01

Full Text Available AbstractI refer to and use as scholarly inspiration Charmaz’s excellent article on constructivist grounded theory as a tool of getting to the fundamental issues on why grounded theory is not constructivist. I show that constructivist data, if it exists at all, is a very, very small part of the data that grounded theory uses.

Ground waves caused by gas cloud explosions and their effects on nuclear power plant structures

International Nuclear Information System (INIS)

Werkle, H.; Waas, G.

1983-01-01

The response of embedded structures to ground waves caused by the explosion of a gas cloud is studied. In the first step, the free field ground motion is analyzed; then the response of a PWR-building is computed. The analysis of the free-field motion is performed using a two-dimensional plane strain model, whereas the interaction problem of the structure excited by the free-field motion is investigated using an axisymmetric three-dimensional model. The soil is assumed to be viscoelastic and horizontally layered. The equations of motion for the viscoelastic continuum are solved in the frequency domain by a semianalytic method. The travelling surface loads from air pressure waves are represented by superposition of line loads. The superposition takes advantage of the mathematical properties of the Fourier transforms. Explicit ring load solutions are used to solve the three-dimensional interaction problem of a rigid embedded circular foundation excited by a two-dimensional wave field of Rayleigh wave type. (orig./WL)

Locating techniques for nuclear power stations

International Nuclear Information System (INIS)

Hayashi, Masao

1983-01-01

The basic thought in locating nuclear power stations is to examine carefully the suitability of sites and the safety of plants, and in the end, to perfect the safety of public. In Japan, effort is exerted to obtain the trust of local people by carrying out investigation, research and examination from respective standpoints of the government, institutes and industries. The author has engaged in the standardization of the investigation, test and analysis regarding the aseismatic capability of ground, the verifying project in Tadotsu of the coupled vibration of ground and structures, the evaluation of the performance of large vibration tables, the future concept of new locating procedure and so on in the last more than ten years. The technological classification of ground, the technological meaning of active faults, the procedure of the aseismatic design of plants, the difference of earthquake input force according to various locating methods, 12 rules regarding the attenuation of vibration of ground, and the concept of new locating method in the 21st century are explained. As the new locating techniques applicable to central Japan, diluvial ground location, floating location in tunnels, underground location, offshore location and so on must be promoted. (Kako, I.)

Purification of arsenic contaminated ground water using hydrated manganese dioxide

International Nuclear Information System (INIS)

Raje, N.; Swain, K.K.

2002-01-01

An analytical methodology has been developed for the separation of arsenic from ground water using inorganic material in neutral medium. The separation procedure involves the quantitative retention of arsenic on hydrated manganese dioxide, in neutral medium. The validity of the separation procedure has been checked by a standard addition method and radiotracer studies. Neutron activation analysis (NAA), a powerful measurement technique, has been used for the quantitative determination of arsenic. (author)

Obstacle negotiation control for a mobile robot suspended on overhead ground wires by optoelectronic sensors

Science.gov (United States)

Zheng, Li; Yi, Ruan

2009-11-01

Power line inspection and maintenance already benefit from developments in mobile robotics. This paper presents mobile robots capable of crossing obstacles on overhead ground wires. A teleoperated robot realizes inspection and maintenance tasks on power transmission line equipment. The inspection robot is driven by 11 motor with two arms, two wheels and two claws. The inspection robot is designed to realize the function of observation, grasp, walk, rolling, turn, rise, and decline. This paper is oriented toward 100% reliable obstacle detection and identification, and sensor fusion to increase the autonomy level. An embedded computer based on PC/104 bus is chosen as the core of control system. Visible light camera and thermal infrared Camera are both installed in a programmable pan-and-tilt camera (PPTC) unit. High-quality visual feedback rapidly becomes crucial for human-in-the-loop control and effective teleoperation. The communication system between the robot and the ground station is based on Mesh wireless networks by 700 MHz bands. An expert system programmed with Visual C++ is developed to implement the automatic control. Optoelectronic laser sensors and laser range scanner were installed in robot for obstacle-navigation control to grasp the overhead ground wires. A novel prototype with careful considerations on mobility was designed to inspect the 500KV power transmission lines. Results of experiments demonstrate that the robot can be applied to execute the navigation and inspection tasks.

Forecasting Global Horizontal Irradiance Using the LETKF and a Combination of Advected Satellite Images and Sparse Ground Sensors

Science.gov (United States)

Harty, T. M.; Lorenzo, A.; Holmgren, W.; Morzfeld, M.

2017-12-01

The irradiance incident on a solar panel is the main factor in determining the power output of that panel. For this reason, accurate global horizontal irradiance (GHI) estimates and forecasts are critical when determining the optimal location for a solar power plant, forecasting utility scale solar power production, or forecasting distributed, behind the meter rooftop solar power production. Satellite images provide a basis for producing the GHI estimates needed to undertake these objectives. The focus of this work is to combine satellite derived GHI estimates with ground sensor measurements and an advection model. The idea is to use accurate but sparsely distributed ground sensors to improve satellite derived GHI estimates which can cover large areas (the size of a city or a region of the United States). We use a Bayesian framework to perform the data assimilation, which enables us to produce irradiance forecasts and associated uncertainties which incorporate both satellite and ground sensor data. Within this framework, we utilize satellite images taken from the GOES-15 geostationary satellite (available every 15-30 minutes) as well as ground data taken from irradiance sensors and rooftop solar arrays (available every 5 minutes). The advection model, driven by wind forecasts from a numerical weather model, simulates cloud motion between measurements. We use the Local Ensemble Transform Kalman Filter (LETKF) to perform the data assimilation. We present preliminary results towards making such a system useful in an operational context. We explain how localization and inflation in the LETKF, perturbations of wind-fields, and random perturbations of the advection model, affect the accuracy of our estimates and forecasts. We present experiments showing the accuracy of our forecasted GHI over forecast-horizons of 15 mins to 1 hr. The limitations of our approach and future improvements are also discussed.

Space solar power - An energy alternative

Science.gov (United States)

Johnson, R. W.

1978-01-01

The space solar power concept is concerned with the use of a Space Power Satellite (SPS) which orbits the earth at geostationary altitude. Two large symmetrical solar collectors convert solar energy directly to electricity using photovoltaic cells woven into blankets. The dc electricity is directed to microwave generators incorporated in a transmitting antenna located between the solar collectors. The antenna directs the microwave beam to a receiving antenna on earth where the microwave energy is efficiently converted back to dc electricity. The SPS design promises 30-year and beyond lifetimes. The SPS is relatively pollution free as it promises earth-equivalence of 80-85% efficient ground-based thermal power plant.

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)

Rigour and grounded theory.

Science.gov (United States)

Cooney, Adeline

2011-01-01

This paper explores ways to enhance and demonstrate rigour in a grounded theory study. Grounded theory is sometimes criticised for a lack of rigour. Beck (1993) identified credibility, auditability and fittingness as the main standards of rigour for qualitative research methods. These criteria were evaluated for applicability to a Straussian grounded theory study and expanded or refocused where necessary. The author uses a Straussian grounded theory study (Cooney, In press) to examine how the revised criteria can be applied when conducting a grounded theory study. Strauss and Corbin (1998b) criteria for judging the adequacy of a grounded theory were examined in the context of the wider literature examining rigour in qualitative research studies in general and grounded theory studies in particular. A literature search for 'rigour' and 'grounded theory' was carried out to support this analysis. Criteria are suggested for enhancing and demonstrating the rigour of a Straussian grounded theory study. These include: cross-checking emerging concepts against participants' meanings, asking experts if the theory 'fit' their experiences, and recording detailed memos outlining all analytical and sampling decisions. IMPLICATIONS FOR RESEARCH PRACTICE: The criteria identified have been expressed as questions to enable novice researchers to audit the extent to which they are demonstrating rigour when writing up their studies. However, it should not be forgotten that rigour is built into the grounded theory method through the inductive-deductive cycle of theory generation. Care in applying the grounded theory methodology correctly is the single most important factor in ensuring rigour.

Mitigation of ground motion effects in linear accelerators via feed-forward control

Directory of Open Access Journals (Sweden)

J. Pfingstner

2014-12-01

Full Text Available Ground motion is a severe problem for many particle accelerators, since it excites beam oscillations, which decrease the beam quality and create beam-beam offset (at colliders. Orbit feedback systems can only compensate ground motion effects at frequencies significantly smaller than the beam repetition rate. In linear colliders, where the repetition rate is low, additional counter measures have to be put in place. For this reason, a ground motion mitigation method based on feed-forward control is presented in this paper. It has several advantages compared to other techniques (stabilization systems and intratrain feedback systems such as cost reduction and potential performance improvement. An analytical model is presented that allows the derivation of hardware specification and performance estimates for a specific accelerator and ground motion model. At the Accelerator Test Facility (ATF2, ground motion sensors have been installed to verify the feasibility of important parts of the mitigation strategy. In experimental studies, it has been shown that beam excitations due to ground motion can be predicted from ground motion measurements on a pulse-to-pulse basis. Correlations of up to 80% between the estimated and measured orbit jitter have been observed. Additionally, an orbit jitter source was identified and has been removed, which halved the orbit jitter power at ATF2 and shows that the feed-forward scheme is also very useful for the detection of installation issues. We believe that the presented mitigation method has the potential to reduce costs and improve the performance of linear colliders and potentially other linear accelerators.

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.

Wind power policy in Norway

International Nuclear Information System (INIS)

2002-01-01

The Norwegian government's ambition of developing 3 TWh wind power by 2010 seems hard to fulfill. Recently Norway's first wind park was officially opened on the island of Smoela, just off Kristiansund. The 20 large windmills are Danish-made and described in some detail in this article. Fulfillment of the government's ambition requires that 20 similar power stations are put into operation the coming eight years, and so far it has not been decided to build the next one. Statkraft have great ambitions for wind power. However, environmental considerations present difficulties. For instance, for Smoela, Statkraft spent an extra 4 million NOK on ground cables the last 1.5 km to land in order to minimize the disturbance of bird populations. Considerations for the white-tailed eagle may be a decisive factor in the development of wind power plants in Norway

Environmental Durability Issues for Solar Power Systems in Low Earth Orbit

Science.gov (United States)

Degroh, Kim K.; Banks, Bruce A.; Smith, Daniela C.

1994-01-01

Space solar power systems for use in the low Earth orbit (LEO) environment experience a variety of harsh environmental conditions. Materials used for solar power generation in LEO need to be durable to environmental threats such as atomic oxygen, ultraviolet (UV) radiation, thermal cycling, and micrometeoroid and debris impact. Another threat to LEO solar power performance is due to contamination from other spacecraft components. This paper gives an overview of these LEO environmental issues as they relate to space solar power system materials. Issues addressed include atomic oxygen erosion of organic materials, atomic oxygen undercutting of protective coatings, UV darkening of ceramics, UV embrittlement of Teflon, effects of thermal cycling on organic composites, and contamination due to silicone and organic materials. Specific examples of samples from the Long Duration Exposure Facility (LDEF) and materials returned from the first servicing mission of the Hubble Space Telescope (HST) are presented. Issues concerning ground laboratory facilities which simulate the LEO environment are discussed along with ground-to-space correlation issues.

Soil–structure interaction analyses to locate nuclear power plant free-field seismic instrumentation

Energy Technology Data Exchange (ETDEWEB)

Johnson, James J., E-mail: jasjjoh@aol.com [James J. Johnson and Associates, Alamo, CA (United States); Ake, Jon P. [US Nuclear Regulatory Commission, Washington, DC (United States); Maslenikov, Oleg R. [James J. Johnson and Associates, Alamo, CA (United States); Kenneally, Roger M. [Consultant, Seminole, FL (United States)

2015-12-15

Highlights: • Determine the location of seismic instrumentation so that recorded motion will be free-field motion. • Certified Designs of nuclear island for AP1000 and EPR; ABWR Reactor Building were analyzed. • Three site conditions and multiple recorded time histories were considered. • Instrumentation located 1-diameter from the edge of structure/foundation is adequate. • Acceptance criteria were probability of non-exceedance of response spectra values. - Abstract: The recorded earthquake ground motion at the nuclear power plant site is needed for several purposes. US Nuclear Regulatory Commission (NRC) Regulatory Guide 1.12, Nuclear Power Plant Instrumentation for Earthquakes, NRC (1997a), describes acceptable instrumentation to meet the requirements in NRC's regulations pertaining to earthquake engineering criteria for nuclear power plants. The ground motion data recorded by the free-field seismic instrumentation are used to compare the actual earthquake motion at the site with the design input motion. The result of the comparison determines if the Operating Basis Earthquake ground motion (OBE) has been exceeded and plant shutdown is required per the guidance in NRC Regulatory Guide 1.166, Pre-Earthquake Planning and Immediate Nuclear Power Plant Operator Postearthquake Actions, NRC (1979b). The free-field is defined as a location on the ground surface or in the site soil column that is sufficiently distant from the site structures to be essentially unaffected by the vibration of the site structures.

Ground movements associated with gas hydrate production

International Nuclear Information System (INIS)

Siriwardane, H.J.; Kutuk, B.

1992-03-01

This report deals with a study directed towards a modeling effort on production related ground movements and subsidence resulting from hydrate dissociation. The goal of this research study was to evaluate whether there could be subsidence related problems that could be an impediment to hydrate production. During the production of gas from a hydrate reservoir, it is expected that porous reservoir matrix becomes more compressible which may cause reservoir compression (compaction) under the influence of overburden weight. The overburden deformations can propagate its influence upwards causing subsidence near the surface where production equipment will be located. In the present study, the reservoir compaction is modeled by using the conventional ''stress equilibrium'' approach. In this approach, the overburden strata move under the influence of body force (i.e. self weight) in response to the ''cavity'' generated by reservoir depletion. The present study is expected to provide a ''lower bound'' solution to the subsidence caused by hydrate reservoir depletion. The reservoir compaction anticipated during hydrate production was modeled by using the finite element method, which is a powerful computer modeling technique. The ground movements at the reservoir roof (i.e. reservoir compression) cause additional stresses and disturbance in the overburden strata. In this study, the reservoir compaction was modeled by using the conventional ''stress equilibrium'' approach. In this approach, the overburden strata move under the influence of body force (i.e. self weight) in response to the ''cavity'' generated by reservoir depletion. The resulting stresses and ground movements were computed by using the finite element method. Based on the parameters used in this investigation, the maximum ground subsidence could vary anywhere from 0.50 to 6.50 inches depending on the overburden depth and the size of the depleted hydrate reservoir

Ground test program for a full-size solar dynamic heat receiver

Science.gov (United States)

Sedgwick, L. M.; Kaufmann, K. J.; Mclallin, K. L.; Kerslake, T. W.

1991-01-01

Test hardware, facilities, and procedures were developed to conduct ground testing of a full-size, solar dynamic heat receiver in a partially simulated, low earth orbit environment. The heat receiver was designed to supply 102 kW of thermal energy to a helium and xenon gas mixture continuously over a 94 minute orbit, including up to 36 minutes of eclipse. The purpose of the test program was to quantify the receiver thermodynamic performance, its operating temperatures, and thermal response to changes in environmental and power module interface boundary conditions. The heat receiver was tested in a vacuum chamber using liquid nitrogen cold shrouds and an aperture cold plate. Special test equipment was designed to provide the required ranges in interface boundary conditions that typify those expected or required for operation as part of the solar dynamic power module on the Space Station Freedom. The support hardware includes an infrared quartz lamp heater with 30 independently controllable zones and a closed-Brayton cycle engine simulator to circulate and condition the helium-xenon gas mixture. The test article, test support hardware, facilities, and instrumentation developed to conduct the ground test program are all described.

Overview of Intelligent Power Controller Development for Human Deep Space Exploration

Science.gov (United States)

Soeder, James F.; Dever, Timothy P.; McNelis, Anne M.; Beach, Raymond F.; Trase, Larry M.; May, Ryan D.

2014-01-01

Intelligent or autonomous control of an entire spacecraft is a major technology that must be developed to enable NASA to meet its human exploration goals. NASA's current long term human space platform, the International Space Station, is in low Earth orbit with almost continuous communication with the ground based mission control. This permits the near real-time control by the ground of all of the core systems including power. As NASA moves beyond low Earth orbit, the issues of communication time-lag and lack of communication bandwidth beyond geosynchronous orbit does not permit this type of operation. This paper presents the work currently ongoing at NASA to develop an architecture for an autonomous power control system as well as the effort to assemble that controller into the framework of the vehicle mission manager and other subsystem controllers to enable autonomous control of the complete spacecraft. Due to the common problems faced in both space power systems and terrestrial power system, the potential for spin-off applications of this technology for use in micro-grids located at the edge or user end of terrestrial power grids for peak power accommodation and reliability are described.

Grounding of SNS Accelerator Structure

CERN Document Server

Holik, Paul S

2005-01-01

Description of site general grounding network. RF grounding network enhancement underneath the klystron gallery building. Grounding network of the Ring Systems with ground breaks in the Ring Tunnel. Grounding and Bonding of R&D accelerator equipment. SNS Building lightning protection.

Air concentration and ground deposition following radioactive airborne releases

International Nuclear Information System (INIS)

Brofferio, C.; Cagnetti, P.; Ferrara, V.

1985-01-01

The fundamental aim of this report is to provide the mathematical and physical operational basis for the evaluation of air concentration and ground deposition, following radioactive airborne releases from a nuclear power plant, both during normal operations and in accidental conditions. As far as accidental releases are concerned, the basical assumptions on meteorological and diffusive situation are considered from a safety point of view: namely those pessimistic but realistically representative situation are taken into account which lead to maximum air concentration and ground deposition values, even if characterized by low recurrence probability. Those elements are the inputs for many environmental transfer models of maximum consequence evaluations up to man. As far as routine releases are concerned, it is shown, together with the usual models based on long term averaged meteorological conditions, also models studied to estimate atmospheric diffusion and deposition in low wind situations and in fog conditions, being those latter very frequent in the Po valley. Finally, the main operations and modalities of collecting and elaborating meteorological data for for radioprotection evaluations are also shown. It is to be pointed out that the methods and the models developed and considered in this work are of a more general validity, and can be also used for applications concerning non-radioactive releases, as it is the case when dealing with conventional power plants

Aseismic design of Hamaoka Nuclear Power Plant

International Nuclear Information System (INIS)

Mizuno, Norihiro

1975-01-01

The Hamaoka Nuclear Power Plant of Chubu Electric Power Co. is designed so as to maintain structural safety against an earthquake of 300 gal. For the purpose, a compound-type reactor-housing building is employed, which contains a reactor, operation control and waste disposal facilities. The merits accruing from this scheme are as follows. (1) The shielding walls of the waste disposal facility can be utilized effectively in aseismatic design, leading to the increased rigidity of the building and the uniform distribution of resistance. (2) Due to the large area of the foundation, the load in earthquake can be mitigated, and it resulted in the higher structural stability. Moreover, seismic energy can be dissipated into ground. After the description of the compound building structure, it is explained how the structural resistance and the ground dissipation of seismic energy contribute to potential earthquake resistance. (Mori, K.)

Commanding Heights? The Strength of Fragility of Business Power in Global Politics

NARCIS (Netherlands)

Fuchs, D.A.

2004-01-01

International relations urgently needs theoretical development that takes into the account the power of non-state actors, in particular business. The present paper aims to prepare the ground for such theoretical development by analysing the political power of business along three dimensions: its

Space power station. Uchu hatsuden

Energy Technology Data Exchange (ETDEWEB)

Kudo, I. (Electrotechnical Laboratory, Tsukuba (Japan))

1993-02-20

A calculation tells that the amount of electric power the world will use in the future will require 100 to 500 power plants each with an output of 5-GW class. If this conception is true, it is beyond dispute that utilizing nuclear power will constitute a core of the power generation even though the geographical conditions are severe for nuclear power plants. It is also certain that power generation using clean solar energy will play important roles if power supply stability can be achieved. This paper describes plans to develop space solar power generation and space nuclear power generation that can supply power solving problems concerning geographical conditions and power supply stability. The space solar power generation is a system to arrest solar energy on a static orbit. According to a result of discussions in the U.S.A., the plan calls for solar cell sheets spread over the surface of a structure with a size of 5 km [times] 10 km [times] 0.5 km thick, and electric power obtained therefrom is transmitted to a rectenna with a size of 10 km [times] 13 km, a receiving antenna on the ground. The space nuclear power generation will be constructed similarly on a static orbit. Researches on space nuclear reactors have already begun. 10 refs., 8 figs., 1 tab.

Water management and reuse opportunities in a thermal power ...

African Journals Online (AJOL)

The Rehab power plant located in the Northern part of Jordan is presented as a case study of industrial water management. This power plant consumes boiler feed water in the amount of 200 m3/d of the fresh ground water available from nearby wells and it produces 193 m3/d of wastewater. Fifty seven water samples were ...

Theory of Nonlinear Dispersive Waves and Selection of the Ground State

International Nuclear Information System (INIS)

Soffer, A.; Weinstein, M.I.

2005-01-01

A theory of time-dependent nonlinear dispersive equations of the Schroedinger or Gross-Pitaevskii and Hartree type is developed. The short, intermediate and large time behavior is found, by deriving nonlinear master equations (NLME), governing the evolution of the mode powers, and by a novel multitime scale analysis of these equations. The scattering theory is developed and coherent resonance phenomena and associated lifetimes are derived. Applications include Bose-Einstein condensate large time dynamics and nonlinear optical systems. The theory reveals a nonlinear transition phenomenon, 'selection of the ground state', and NLME predicts the decay of excited state, with half its energy transferred to the ground state and half to radiation modes. Our results predict the recent experimental observations of Mandelik et al. in nonlinear optical waveguides

Ground mounted photovoltaic installations. Guide for an impact study

International Nuclear Information System (INIS)

2011-01-01

Legally, an impact study must be performed for ground mounted photovoltaic installations with a power greater than 250 kW. This guide is aimed at helping the actors of the photovoltaic sector to perform impact studies. After the description of the characteristics of a photovoltaic installation (principles, technical characteristics of a ground mounted installation, impact of photovoltaic systems on climate) and a presentation of the legal framework (European commitments, Grenelle de l'Environnement, applicable procedures), this report present the objectives and approach of an impact study, describes how the environment is taken into account from the early stages of a project, how the impact study is to be prepared. The last part describes the different components of the impact study: legal content, project description, analysis of the site initial status and environment, analysis of the project effects, rationale for the choice of the project

MFTF 230 kV pulsed power substation

International Nuclear Information System (INIS)

Wilson, J.H.

1979-01-01

The Mirror Fusion Test Facility (MFTF) currently under construction at the Lawrence Livermore Laboratory includes a Sustaining Neutral Beam Power Supply System (SNBPSS) consisting of 24 power-supply sets. The System will operate in long pulses (initially .5 seconds and eventually 30 seconds) at high power (200 MW), which will necessitate a large source of ac power. To meet this requirement, a new 230-kV substation is also being built at LLL. The constraints of cost, equipment protection, short operating lifetime (10 years), and reliability dictated a unique substation design. Its unusual features include provisions for fast fault detection and tripping, a capability for limiting ground fault current, low impedance, and economical design

Experimental simulation of ground motion effects

International Nuclear Information System (INIS)

Syphers, M.J.; Chao, A.W.; Dutt, S.; Yan, Y.T.; Zhang, P.L.; Ball, M.; Brabson, B.; Budnick, J.; Caussyn, D.D.; Collins, J.; Derenchuk, V.; East, G.; Ellison, M.; Ellison, T.; Friesel, D.; Hamilton, B.; Huang, H.; Jones, W.P.; Lee, S.Y.; Li, D.; Nagaitsev, S.; Pei, X.; Rondeau, G.; Sloan, T.; Minty, M.G.; Gabella, W.; Ng, K.Y.; Teng, L.; Tepikian, S.

1993-05-01

Synchro-betatron coupling in a proton storage ring with electron cooling was studied by modulating a transverse dipole field close to the synchrotron frequency. The combination of the electron cooling and transverse field modulation on the synchrotron oscillation is equivalent to a dissipative parametric resonant system. The proton bunch was observed to split longitudinally into two pieces, or beamlets, converging toward strange attractors of the dissipative system. These phenomena might be important to understanding the effect of ground vibration on the SSC beam, where the synchrotron frequency is about 4 ∼ 7 Hz, and the effect of power supply ripple on the RHIC beam, where the synchrotron frequency ramps through 60 Hz at 17 GeV/c

Experimental simulation of ground motion effects

Energy Technology Data Exchange (ETDEWEB)

Syphers, M.J.; Chao, A.W.; Dutt, S.; Yan, Y.T.; Zhang, P.L. [Superconducting Super Collider Lab., Dallas, TX (United States); Ball, M.; Brabson, B.; Budnick, J.; Caussyn, D.D.; Collins, J.; Derenchuk, V.; East, G.; Ellison, M.; Ellison, T.; Friesel, D.; Hamilton, B.; Huang, H.; Jones, W.P.; Lee, S.Y.; Li, D.; Nagaitsev, S.; Pei, X.; Rondeau, G.; Sloan, T. [Indiana Univ. Cyclotron Facility, Bloomington, IN (United States); Minty, M.G. [Stanford Linear Accelerator Center, Menlo Park, CA (United States); Gabella, W.; Ng, K.Y. [Fermi National Accelerator Lab., Batavia, IL (United States); Teng, L. [Argonne National Lab., IL (United States); Tepikian, S. [Brookhaven National Lab., Upton, NY (United States)

1993-05-01

Synchro-betatron coupling in a proton storage ring with electron cooling was studied by modulating a transverse dipole field close to the synchrotron frequency. The combination of the electron cooling and transverse field modulation on the synchrotron oscillation is equivalent to a dissipative parametric resonant system. The proton bunch was observed to split longitudinally into two pieces, or beamlets, converging toward strange attractors of the dissipative system. These phenomena might be important to understanding the effect of ground vibration on the SSC beam, where the synchrotron frequency is about 4 {approximately} 7 Hz, and the effect of power supply ripple on the RHIC beam, where the synchrotron frequency ramps through 60 Hz at 17 GeV/c.

Experimental Simulation of Ground Motion Effects

Energy Technology Data Exchange (ETDEWEB)

Minty, Michiko G

2003-07-11

Synchro-betatron coupling in a proton storage ring with electron cooling was studied by modulating a transverse dipole field close to the synchrotron frequency. The combination of the electron cooling and transverse field modulation on the synchrotron oscillation is equivalent to a dissipative parametric resonant system. The proton bunch was observed to split longitudinally into two pieces, or beamlets, converging toward strange attractors of the dissipative system. These phenomena might be important to understanding the effect of ground vibration on the SSC beam, where the synchrotron frequency is about 4 {approx} 7 Hz, and the effect of power supply ripple on the RHIC beam, where the synchrotron frequency ramps through 60 Hz at 17 GeV/c.

Evaluation of seismic hazards for nuclear power plants. Safety guide

International Nuclear Information System (INIS)

2002-01-01

The main objective of this Safety Guide is to provide recommendations on how to determine the ground motion hazards for a plant at a particular site and the potential for surface faulting, which could affect the feasibility of construction and safe operation of a plant at that site. The guidelines and procedures presented in this Safety Guide can appropriately be used in evaluations of site suitability and seismic hazards for nuclear power plants in any seismotectonic environment. The probabilistic seismic hazard analysis recommended in this Safety Guide also addresses the needs for seismic hazard analysis of external event PSAs conducted for nuclear power plants. Many of the methods and processes described may also be applicable to nuclear facilities other than power plants. Other phenomena of permanent ground displacement (liquefaction, slope instability, subsidence and collapse) as well as the topic of seismically induced flooding are treated in Safety Guides relating to foundation safety and coastal flooding. Recommendations of a general nature are given in Section 2. Section 3 discusses the acquisition of a database containing the information needed to evaluate and address all hazards associated with earthquakes. Section 4 covers the use of this database for construction of a seismotectonic model. Sections 5 and 6 review ground motion hazards and evaluations of the potential for surface faulting, respectively. Section 7 addresses quality assurance in the evaluation of seismic hazards for nuclear power plants

Estimating the seismotelluric current required for observable electromagnetic ground signals

Directory of Open Access Journals (Sweden)

J. Bortnik

2010-08-01

Full Text Available We use a relatively simple model of an underground current source co-located with the earthquake hypocenter to estimate the magnitude of the seismotelluric current required to produce observable ground signatures. The Alum Rock earthquake of 31 October 2007, is used as an archetype of a typical California earthquake, and the effects of varying the ground conductivity and length of the current element are examined. Results show that for an observed 30 nT pulse at 1 Hz, the expected seismotelluric current magnitudes fall in the range ~10–100 kA. By setting the detectability threshold to 1 pT, we show that even when large values of ground conductivity are assumed, magnetic signals are readily detectable within a range of 30 km from the epicenter. When typical values of ground conductivity are assumed, the minimum current required to produce an observable signal within a 30 km range was found to be ~1 kA, which is a surprisingly low value. Furthermore, we show that deep nulls in the signal power develop in the non-cardinal directions relative to the orientation of the source current, indicating that a magnetometer station located in those regions may not observe a signal even though it is well within the detectable range. This result underscores the importance of using a network of magnetometers when searching for preseismic electromagnetic signals.

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.

The Frustrations of Reader Generalizability and Grounded Theory: Alternative Considerations for Transferability

Directory of Open Access Journals (Sweden)

Thomas Misco

2007-01-01

Full Text Available In this paper I convey a recurring problem and possible solution that arose during my doctoral research on the topic of cross-cultural Holocaust curriculum development for Latvian schools. Specifically, as I devised the methodology for my research, I experienced a number of frustrations concerning the issue of transferability and the limitations of both reader generalizability and grounded theory. Ultimately, I found a more appropriate goal for the external applicability of this and other highly contextual research studies in the form of "grounded understandings," which are tentative apprehensions of the importance or significance of phenomena and conceptualizations that hold meaning and explanatory power, but are only embryonic in their potential to generate theory.

Jung's equation of the ground of being with the ground of psyche.

Science.gov (United States)

Dourley, John

2011-09-01

The paper amplifies Jung's psychology of ground associated with the culmination of the alchemical process in the unus mundus. It argues that Jung and Dorn identify the experience of the ground with the experience of divinity as the common originary source of individual and totality. It notes the monistic and pantheistic implications of the experience and goes on to amplify the experience through Eckhart's mediaeval mysticism of ground and Paul Tillich's modern philosophical/theological understanding of ground. It concludes that the Jung/Dorn psychological understanding of ground supersedes monotheistic consciousness. Their vision supports the emergence of a societal myth based on the identification of the ground as the source of all divinities and faith in them. This source currently urges a mythic consciousness that would surpass its past and current concretions and so alleviate the threat that monotheistic consciousness in any domain now poses to human survival. © 2011, The Society of Analytical Psychology.

Site preparation works for No.3 plant in Ikata Nuclear Power Station, Shikoku Electric Power Co., Inc

International Nuclear Information System (INIS)

Ishihara, Hisashi; Nakajima, Hiroshi; Oshima, Teruhiko

1986-01-01

Ikata Power Station is only nuclear power station in Shikoku located at the root of Sadamisaki Peninsula. No.1 plant started the operation in September, 1977, and No.2 plant started the operation in March, 1982. By constructing No.3 plant of 890 MWe output, the total power output will be 2.022 million kW. No.3 plant is installed adjacently to No.1 and No.2 plants on their east side. In this place, the existing facilities of the harbor and others can be effectively utilized, the nature of ground is solid, and the fundamental condition of location is perfect, it is easy to obtain the cooperation of local people as No.1 and No.2 plants have been in operation, and it is advantageous in view of the construction period for the power supply plan. The site preparation works have progressed smoothly since the start in June, 1985. About 100,000 m 2 of the site is created by cutting natural ground, and about 54,000 m 2 is created by sea reclamation. About 5 million m 3 of earth and stone generated by cutting and excavation are utilized for reclamation, revetment and others. The topographic and geological features, sea condition, the outline of geological survey, the layout, and the construction works of revetment, cutting, the creation of substitute seaweed farm, appurtenant works, and the measures for environment preservation are described. (Kako, I.)

Solar power satellite system; Uchu hatsuden system

Energy Technology Data Exchange (ETDEWEB)

Sasaki, S [Institute of Space and Astronautical Science, Tokyo (Japan)

1995-09-05

The solar power satellite system is a system that converts solar energy into electric energy in the space, transmits power to earth through wireless resort such as microwave and supplies energy of new concept. In order to realize this system it is necessary to have new technologies such as space power transmission at low cost, construction of large space buildings and wireless high power transmission. In this paper, the principles, characteristics and the necessary technology of this system were explained. Besides Japan`s SPS2000 Plan (cooperative research by universities, government agencies and private corporations on the model of solar power satellite) the group of Europe, Russia and the United States has also proposed some ideas concerning the solar power satellite system. As far as the microwave power transmission, which is the key technology for solar power satellite system, is concerned, ground demonstration tests at the level of several tens of kW are discussed in Canada and France. 3 refs., 3 figs.

Ground Water in the Anchorage Area, Alaska--Meeting the Challenges of Ground-Water Sustainability

Science.gov (United States)

Moran, Edward H.; Galloway, Devin L.

2006-01-01

Ground water is an important component of Anchorage's water supply. During the 1970s and early 80s when ground water extracted from aquifers near Ship Creek was the principal source of supply, area-wide declines in ground-water levels resulted in near record low streamflows in Ship Creek. Since the importation of Eklutna Lake water in the late 1980s, ground-water use has been reduced and ground water has contributed 14-30 percent of the annual supply. As Anchorage grows, given the current constraints on the Eklutna Lake water availability, the increasing demand for water could place an increasing reliance on local ground-water resources. The sustainability of Anchorage's ground-water resources challenges stakeholders to develop a comprehensive water-resources management strategy.

Ground-water contamination and legal controls in Michigan

Science.gov (United States)

Deutsch, Morris

1963-01-01

The great importance of the fresh ground-water resources of Michigan is evident because 90 percent of the rural and about 70 percent of the total population of the State exclusive of the Detroit metropolitan area are supplied from underground sources. The water-supply and public-health problems that have been caused by some cases of ground-water contamination in the State illustrate the necessity of protecting this vital resource.Manmade and natural contaminants, including many types of chemical and organic matter, have entered many of the numerous aquifers of the State. Aquifers have been contaminated by waste-laden liquids percolating from the surface or from the zone of aeration and by direct injection to the aquifer itself. Industrial and domestic wastes, septic tanks, leaking sewers, flood waters or other poor quality surface waters, mine waters, solids stored or spread at the surface, and even airborne wastes all have been sources of ground-water contamination in Michigan. In addition, naturally occurring saline waters have been induced into other aquifers by overpumping or unrestricted flow from artesian wells, possibly by dewatering operations, and by the deepening of surface stream channels. Vertical migration of saline waters through open holes from formations underlying various important aquifers also has spoiled some of the fresh ground waters in the State. In spite of the contamination that has occurred, however, the total amount of ground water that has been spoiled is only a small part of the total resource. Neither is the contamination so widespread as that of the surface streams of Michigan.Overall legal authority to control most types of ground-water contamination in the State has been assigned by the Michigan Legislature to the Water Resources Commission, although the Department of Conservation and the Health Department also exercise important water-pollution control functions. The Michigan Supreme Court, in an important case upholding the power

The atlas of large photovoltaic power plants

International Nuclear Information System (INIS)

Le Jannic, N.; Guillier, A.

2013-01-01

This document reviews all the photovoltaic power plants settled in France and whose power output is over 1 MWc. 320 facilities have been reported, they are either operating or awaiting to be connected to the grid. The total cumulated power reaches 1542 MWc. For each facility we have the name of the operator, the output power, the name of the manufacturer of the silicon modules and their type (polycrystalline or mono-crystalline), the kind of settling (on the ground or integrated to the building), the annual power output and its date of commissioning. Sunshine level curves are drawn on a map of the country, it ranges from about 1100 kWh/m 2 a year in the northern part to about 1900 kWh/m 2 a year near the mediterranean sea. (A.C.)

Adaptive Neural Network Algorithm for Power Control in Nuclear Power Plants

International Nuclear Information System (INIS)

Husam Fayiz, Al Masri

2017-01-01

The aim of this paper is to design, test and evaluate a prototype of an adaptive neural network algorithm for the power controlling system of a nuclear power plant. The task of power control in nuclear reactors is one of the fundamental tasks in this field. Therefore, researches are constantly conducted to ameliorate the power reactor control process. Currently, in the Department of Automation in the National Research Nuclear University (NRNU) MEPhI, numerous studies are utilizing various methodologies of artificial intelligence (expert systems, neural networks, fuzzy systems and genetic algorithms) to enhance the performance, safety, efficiency and reliability of nuclear power plants. In particular, a study of an adaptive artificial intelligent power regulator in the control systems of nuclear power reactors is being undertaken to enhance performance and to minimize the output error of the Automatic Power Controller (APC) on the grounds of a multifunctional computer analyzer (simulator) of the Water-Water Energetic Reactor known as Vodo-Vodyanoi Energetichesky Reaktor (VVER) in Russian. In this paper, a block diagram of an adaptive reactor power controller was built on the basis of an intelligent control algorithm. When implementing intelligent neural network principles, it is possible to improve the quality and dynamic of any control system in accordance with the principles of adaptive control. It is common knowledge that an adaptive control system permits adjusting the controller’s parameters according to the transitions in the characteristics of the control object or external disturbances. In this project, it is demonstrated that the propitious options for an automatic power controller in nuclear power plants is a control system constructed on intelligent neural network algorithms. (paper)

Noise from wind power plants

International Nuclear Information System (INIS)

Ljunggren, S.

2001-12-01

First, the generation of noise at wind power plants and the character of the sound is described. The propagation of the sound and its dependence on the structure of the ground and on wind and temperature is treated next. Models for calculation of the noise emission are reviewed and examples of applications are given. Different means for reducing the disturbances are described

A study on the dynamic behavior of a large-scale foundation on the soft ground, 2

International Nuclear Information System (INIS)

Ueshima, Teruyuki; Hanada, Kazufumi; Sawada, Yoshihiro; Esashi, Yasuyuki

1983-01-01

In order to study the aseismatic stability of nuclear power plants on soft ground, the estimate of the dynamic behavior of a large foundation on soft ground by exciting it was carried out. The computer program named ''TB3D1'' was used for the analysis, which was developed by the Central Research Institute of Electric Power Industry, and is the code for simulating soilstructure interaction in the horizontal excitation of buildings and/or foundations. The calculated results were compared with the measured results. In view of the amplitude and phase lag, the resonance curves estimated agreed fairly well with those by the measurement both on the foundation and on or in the ground up to 12 Hz. As to the earth pressure distribution, the calculated results were tolerable. Therefore, the computer code ''TB3D1'' was verified to be sufficiently effective and useful. By the 2-D FEM with pseudo 3-D dampers, the first natural frequency coincided, but the amplitude was very small as compared with the measured results. According to the sway-rocking model with two degrees of freedom, the dynamic behavior of the foundation was roughly simulated. (Kako, I.)

[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.

Geothermal energy. Ground source heat pumps

International Nuclear Information System (INIS)

2009-01-01

Geothermal energy can be harnessed in 2 different ways: electricity or heat generation. The combined net electrical geothermal power of the European Union countries reached 719.3 MWe in 2008 (4.8 MW up on 2007) for 868.1 MWe of installed capacity. Gross electrical production contracted slightly in 2008 (down 1% on the 2007 level) and stood at 5809.5 GWh in 2008. Italy has a overwhelming position with a production of 5520.3 GWh. Geothermal heat production concerning aquifers whose temperature is 30-150 C. degrees generally at a depth of 1-3 km is called low- and medium-enthalpy energy. 18 of the 27 EU members use low- and medium-enthalpy energy totaling 2560.0 MWth of installed capacity that yielded 689.2 ktoe in 2008 and 3 countries Hungary, Italy and France totaling 480.3 ktoe. Very low-enthalpy energy concerns the exploitation of shallow geothermal resources using geothermal heat pumps. In 2008, 114452 ground heat pumps were sold in Europe. At the end of 2008, the installed capacity was 8955.4 MWth (16.5% up on 2007 level, it represented 785206 pumps. Over one million ground heat pumps are expected to be operating in 2010 in Europe. (A.C.)

Design and development of an automated D.C. ground fault detection and location system for Cirus

International Nuclear Information System (INIS)

Marik, S.K.; Ramesh, N.; Jain, J.K.; Srivastava, A.P.

2002-01-01

Full text: The original design of Cirus safety system provided for automatic detection of ground fault in class I D.C. power supply system and its annunciation followed by delayed reactor trip. Identification of a faulty section was required to be done manually by switching off various sections one at a time thus requiring a lot of shutdown time to identify the faulty section. Since class I power supply is provided for safety control system, quick detection and location of ground faults in this supply is necessary as these faults have potential to bypass safety interlocks and hence the need for a new system for automatic location of a faulty section. Since such systems are not readily available in the market, in-house efforts were made to design and develop a plant-specific system, which has been installed and commissioned

Validation of Sodar Measurements for Wind Power

OpenAIRE

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, espec...

Rf system description for the ground test accelerator radio-frequency quadrupole

International Nuclear Information System (INIS)

Regan, A.H.; Brittain, D.; Rees, D.E.; Ziomek, D.

1992-01-01

This paper describes the RF system being used to provide RF power and to control the cavity field used for the ground test accelerator (GTA) radio-frequency quadrupole (RFQ). The RF system consists of a low-level RF (LLRF) control system that uses a tetrode as a high-power amplifier (HPA) as part of its plant to deliver up to 300 kW of peak power to the RFQ at a 2% duty factor. The LLRF control system implements in-phase and quadrature (I ampersand Q) control to maintain the cavity field within tolerances of 0.5% in amplitude and 0.5 degrees in phase in the presence of beam-induced instabilities. This paper describes the identified components and presents measured performance data. The user interface with the systems is described, and cavity field measurements are included

Organic Rankine kilowatt isotope power system. First annual summary report, August 1, 1975--August 1, 1976

International Nuclear Information System (INIS)

1976-01-01

Sundstrand Energy Systems is developing a Kilowatt Isotope Power System (KIPS) directed toward satisfying the higher power requirements of satellites of the 1980's. The KIPS is a plutonium oxide fueled organic Rankine cycle turbine power system which will provide design output power in the range of 500 to 2000 W(e) with a minimum of system changes. Research progress is reported on Phase I comprising: (1) flight system conceptual design and ground demonstration; (2) flight system design and ground qualification; and (3) flight system production, acceptance testing and delivery. The principal objectives of Phase I are to: (1) conceptually design the flight system, (2) based on the flight system concept, design and build the ground demonstration system (GDS), (3) conduct performance and endurance testing using electric heaters to simulate the radioisotope heat source, (4) identify and initiate long lead development efforts required to achieve the initial flight qualification hardware availability date of April 1981, and (5) finalize the flight concept design and prepare the program plan for the Phase II effort

A new concept of space solar power satellite

Science.gov (United States)

Li, Xun; Duan, Baoyan; Song, Liwei; Yang, Yang; Zhang, Yiqun; Wang, Dongxu

2017-07-01

Space solar power satellite (SSPS) is a tremendous energy system that collects and converts solar power to electric power in space, and then transmits the electric power to earth wirelessly. In this paper, a novel SSPS concept based on ε-near-zero (ENZ) metamaterial is proposed. A spherical condenser made of ENZ metamaterial is developed, by using the refractive property of the ENZ metamaterial sunlight can be captured and redirected to its center. To make the geometric concentration ratio of the PV array reasonable, a hemispherical one located at the center is used to collect and convert the normal-incidence sunlight to DC power, then through a phased array transmitting antenna the DC power is beamed down to the rectenna on the ground. Detailed design of the proposed concept is presented.

An Archeological Overview and Management Plan for the Dugway Proving Ground.

Science.gov (United States)

1984-03-29

niches, particulary the lacustrine environment of the Great Basin (Baumhoff and Heizer 1965, Butler 1978, Heizer and Krieger 1956, Heizer and Harper...power that would capture the animals souls, rendering them docile and stupid (Steward 1970:34). Other large game was present, but were not numerous...uni versity. Baum, Bernard. 1947. Dugway Proving Ground. Aberdeen: U.S. Army Chemical Corps.* Bailmhoff, W.A. and R.F. Heizer . 1965. Postglacial

Space- and ground-based particle physics meet at CERN

CERN Multimedia

CERN Bulletin

2012-01-01

The fourth international conference on Particle and Fundamental Physics in Space (SpacePart12) will take place at CERN from 5 to 7 November. The conference will bring together scientists working on particle and fundamental physics in space and on ground, as well as space policy makers from around the world.   One hundred years after Victor Hess discovered cosmic rays using hot air balloons, the experimental study of particle and fundamental physics is still being pursued today with extremely sophisticated techniques: on the ground, with state-of-the-art accelerators like the LHC; and in space, with powerful observatories that probe, with amazing accuracy, the various forms of cosmic radiation, charged and neutral, which are messengers of the most extreme conditions of matter and energy. SpacePart12 will be the opportunity for participants to exchange views on the progress of space-related science and technology programmes in the field of particle and fundamental physics in space. SpacePar...

Gender differences of sagittal knee and ankle biomechanics during stair-to-ground descent transition.

Science.gov (United States)

Hong, Yoon No Gregory; Shin, Choongsoo S

2015-12-01

Falls on stairs often result in severe injury and occur twice as frequently in women. However, gender differences in kinetics and kinematics during stair descent are unknown. Thus, this study aimed to determine whether gender differences of knee and ankle biomechanics exist in the sagittal plane during the stair-to-ground descending transition. It was hypothesized that 1) women would reveal higher ground-toe-trochanter angle and lower ground-toe length during stair-to-ground descent transition than men; and 2) women would reveal lower peak knee extension moment during stair-to-ground descent transition than men. Fifteen men and fifteen women were recruited and performed a stair descent activity. Kinetic and kinematic data were obtained using a force plate and motion capture system. The women performed the stair descent with a lower peak knee extension moment and a peak knee power at the early weight acceptance phase. The women also revealed a higher ground-toe-trochanter angle and a lower ground-toe length, which indicated a more forward position of the lower extremity relative to the toe contact point at both the initial contact and at the time of peak kinematic and kinetic events. This study found that knee and ankle kinematics and kinetics differed significantly between the genders due to differences in ground-toe-trochanter angle. Women have a different stair descending strategy that reduces the demand of the lower extremity muscle function, but this strategy seems to increase the risk of falls. Copyright © 2015 Elsevier Ltd. All rights reserved.

Novel roaming and stationary tethered aerial robots for continuous mobile missions in nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Gu, Beom W.; Choi, Su Y.; Rim, Chun T. [Dept. of Nuclear and Quantum Engineering, KAIST, Daejeon (Korea, Republic of); Choi, Young Soo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Cai, Guowei; Seneviratne, Lakmal [Dept. of Aerospace Engineering, Khalifa University, Abu Dhabi (United Arab Emirates)

2016-08-15

In this paper, new tethered aerial robots including roaming tethered aerial robots (RTARs) for radioactive material sampling and stationary tethered aerial robots (STARs) for environment monitoring are proposed to meet extremely-long-endurance missions of nuclear power plants. The flight of the proposed tethered aerial robots may last for a few days or even a few months as long as the tethered cable provides continuous power. A high voltage AC or DC power system was newly adopted to reduce the mass of the tethered cable. The RTAR uses a tethered cable spooled from the aerial robot and an aerial tension control system. The aerial tension control system provides the appropriate tension to the tethered cable, which is accordingly laid down on the ground as the RTAR roams. The STAR includes a tethered cable spooled from the ground and a ground tension control system, which enables the STAR to reach high altitudes. Prototypes of the RTAR and STAR were designed and successfully demonstrated in outdoor environments, where the load power, power type, operating frequency, and flight attitude of the RTAR and STAR were: 180 W, AC 100 kHz, and 20 m; and 300 W, AC or DC 100 kHz, and 80 m, respectively.

Novel Roaming and Stationary Tethered Aerial Robots for Continuous Mobile Missions in Nuclear Power Plants

Directory of Open Access Journals (Sweden)

Beom W. Gu

2016-08-01

Full Text Available In this paper, new tethered aerial robots including roaming tethered aerial robots (RTARs for radioactive material sampling and stationary tethered aerial robots (STARs for environment monitoring are proposed to meet extremely-long-endurance missions of nuclear power plants. The flight of the proposed tethered aerial robots may last for a few days or even a few months as long as the tethered cable provides continuous power. A high voltage AC or DC power system was newly adopted to reduce the mass of the tethered cable. The RTAR uses a tethered cable spooled from the aerial robot and an aerial tension control system. The aerial tension control system provides the appropriate tension to the tethered cable, which is accordingly laid down on the ground as the RTAR roams. The STAR includes a tethered cable spooled from the ground and a ground tension control system, which enables the STAR to reach high altitudes. Prototypes of the RTAR and STAR were designed and successfully demonstrated in outdoor environments, where the load power, power type, operating frequency, and flight attitude of the RTAR and STAR were: 180 W, AC 100 kHz, and 20 m; and 300 W, AC or DC 100 kHz, and 80 m, respectively.

The Grounded Theory Bookshelf

Directory of Open Access Journals (Sweden)

Dr. Alvita Nathaniel, DSN, APRN, BC

2005-06-01

Full Text Available The Grounded Theory Perspective III: Theoretical Coding, Barney G. Glaser (Sociology Press, 2005. Not intended for a beginner, this book further defi nes, describes, and explicates the classic grounded theory (GT method. Perspective III lays out various facets of theoretical coding as Glaser meticulously distinguishes classic GT from other subsequent methods. Developed many years after Glaser’s classic GT, these methods, particularly as described by Strauss and Corbin, adopt the grounded theory name and engender ongoing confusion about the very premises of grounded theory. Glaser distinguishes between classic GT and the adscititious methods in his writings, referring to remodeled grounded theory and its offshoots as Qualitative Data Analysis (QDA models.

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.

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.)

Space weather effects on ground based technology

Science.gov (United States)

Clark, T.

Space weather can affect a variety of forms of ground-based technology, usually as a result of either the direct effects of the varying geomagnetic field, or as a result of the induced electric field that accompanies such variations. Technologies affected directly by geomagnetic variations include magnetic measurements made d ringu geophysical surveys, and navigation relying on the geomagnetic field as a direction reference, a method that is particularly common in the surveying of well-bores in the oil industry. The most obvious technology affected by induced electric fields during magnetic storms is electric power transmission, where the example of the blackout in Quebec during the March 1989 magnetic storm is widely known. Additionally, space weather effects must be taken into account in the design of active cathodic protection systems on pipelines to protect them against corrosion. Long-distance telecommunication cables may also have to be designed to cope with space weather related effects. This paper reviews the effects of space weather in these different areas of ground-based technology, and provides examples of how mitigation against hazards may be achieved. (The paper does not include the effects of space weather on radio communication or satellite navigation systems).

Nurses' perceptions of leadership style in hospitals: a grounded theory study.

Science.gov (United States)

Su, Shu-Fen; Jenkins, Mary; Liu, Po-Erh

2012-01-01

This paper explores the leadership style of hospital managers. Leadership has been widely studied in nursing from the perspective of nurses' psychological strain caused by nursing leadership. There is, however, little contained in the Western and Eastern literatures on the leadership style of hospital managers and certainly no study has explored managers' leadership style in Taiwanese hospitals from the nurses' stance. Grounded theory. A sample of 28 nurses from seven teaching hospitals in Taiwan, Republic of China was selected through theoretical sampling. A multi-step analytic procedure based on the grounded theory approach was used to analyse the qualitative data. The Chinese culture was found to affect the leadership style of Taiwanese hospital managers. They had extreme power and led nurses in a hierarchical manner. Nurse managers followed the autocratic leadership style of their hospital managers. The main category found in this study was thus hierarchical leadership. The Confucian principles of authoritarianism and obedience were found to be part of the Taiwanese hospitals' organisational cultures and strongly impacted on the managers' leadership style. Hospital managers' treatment of doctors and nurses was dependent on their social rankings. Nurses' lowly ranking fed into these enculturated managerial tendencies of using power and obedience thus increasing psychological strain on nurses. Managers of the hospitals demonstrate power and misuse obedience through their leadership style, resulting in deterioration of nurses' work environment. Nurses' managers are not given enough power by the hospitals in Taiwan. Subsequently, nurses feel themselves the lowest and most powerless subordinates. This study reveals that the Chinese cultural burdens are embedded in the leadership of Taiwanese hospitals. These findings enhance the knowledge of leadership and add to the understanding of managerial attitudes in Chinese hospitals located worldwide. © 2011 Blackwell

Communication, concepts and grounding

NARCIS (Netherlands)

van der Velde, Frank; van der Velde, F.

2015-01-01

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

Contribution to evaluating nuclear power plant accidents

International Nuclear Information System (INIS)

Razga, J.; Horacek, P.

1990-01-01

Large-scale accidents pose the highest risk in the use of nuclear power. They are the major factor that has to be taken into account when assessing the effect of nuclear power plants on human health and on the environment. In Czechoslovak conditions, the effectiveness of provisions made to reduce the hazard of large-scale nuclear power plant accidents must be considered from the following aspects: effect on human health, consequences of long-term disabling of the infrastructure, potential of human and material reserves in coping with the accident, consequences of power failure for the electricity system, effect on agricultural production and catering, risk of ground and surface water contamination in the Labe or Danube river basin, and international political aspects. (Z.M.). 3 tabs., 18 refs

Oil and nuclear power: the dynamic interrelationship

International Nuclear Information System (INIS)

Stauffer, T.

1987-01-01

The impact of changing oil prices on the economic case for nuclear power and the political viability of the nuclear industry is reviewed. The case for nuclear energy is less obvious currently on the grounds of safety (following the Chernobyl accident), need (because of slower economic growth and energy conservation) and rationale (the cost advantage is no longer obvious). Nuclear power and oil prices are shown to be interrelated because the competitive economics of each is affected by the other. The competitive balance between the two changes. The use of nuclear power helps to keep oil prices down. However, if oil is cheap, nuclear power is less favourable economically. Some facts and figures are used to illustrate this paradox. (U.K.)

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.

NPP planning based on analysis of ground vibration caused by collapse of large-scale cooling towers

Energy Technology Data Exchange (ETDEWEB)

Lin, Feng; Ji, Hongkui [Department of Structural Engineering, Tongji University, No. 1239 Siping Road, Shanghai 200092 (China); Gu, Xianglin, E-mail: gxl@tongji.edu.cn [Department of Structural Engineering, Tongji University, No. 1239 Siping Road, Shanghai 200092 (China); Li, Yi [Department of Structural Engineering, Tongji University, No. 1239 Siping Road, Shanghai 200092 (China); Wang, Mingreng; Lin, Tao [East China Electric Power Design Institute Co., Ltd, No. 409 Wuning Road, Shanghai 200063 (China)

2015-12-15

Highlights: • New recommendations for NPP planning were addressed taking into account collapse-induced ground vibration. • Critical factors influencing the collapse-induced ground vibration were investigated. • Comprehensive approach was presented to describe the initiation and propagation of collapse-induced disaster. - Abstract: Ground vibration induced by collapse of large-scale cooling towers can detrimentally influence the safe operation of adjacent nuclear-related facilities. To prevent and mitigate these hazards, new planning methods for nuclear power plants (NPPs) were studied considering the influence of these hazards. First, a “cooling tower-soil” model was developed, verified, and used as a numerical means to investigate ground vibration. Afterwards, five critical factors influencing collapse-induced ground vibration were analyzed in-depth. These influencing factors included the height and weight of the towers, accidental loads, soil properties, overlying soil, and isolation trench. Finally, recommendations relating to the control and mitigation of collapse-induced ground vibration in NPP planning were proposed, which addressed five issues, i.e., appropriate spacing between a cooling tower and the nuclear island, control of collapse modes, sitting of a cooling tower and the nuclear island, application of vibration reduction techniques, and the influence of tower collapse on surroundings.

Subterranean ground motion studies for the Einstein Telescope

International Nuclear Information System (INIS)

Beker, M G; Brand, J F J van den; Rabeling, D S

2015-01-01

Seismic motion limits the low-frequency sensitivity of ground-based gravitational wave detectors. A conceptual design study into the feasibility of a future-generation gravitational wave observatory, coined the Einstein Telescope, has been completed. As part of this design phase, we performed a ground motion study to determine the seismic noise characteristics at various sites across the globe. This investigation focused on underground sites and encompassed a variety of geologies, including clay, salt, and hard rock, at 15 locations in nine European countries, the USA, and Japan. In addition, we analyzed data from the Virtual European Broadband Seismograph Network to characterize European seismic motion. We show that, in the region of interest for future-generation gravitational wave detectors (1–10 Hz), seismic motion is dominated by activity from anthropogenic sources. A number of sites were found that exhibited a reduction in seismic power of several orders of magnitude with respect to current detector sites, thus making it possible to set requirements for the Einstein Telescope seismic noise environment. (paper)

The ground based plan

International Nuclear Information System (INIS)

1989-01-01

The paper presents a report of ''The Ground Based Plan'' of the United Kingdom Science and Engineering Research Council. The ground based plan is a plan for research in astronomy and planetary science by ground based techniques. The contents of the report contains a description of:- the scientific objectives and technical requirements (the basis for the Plan), the present organisation and funding for the ground based programme, the Plan, the main scientific features and the further objectives of the Plan. (U.K.)

Fault diagnostics in power transformer model winding for different alpha values

Directory of Open Access Journals (Sweden)

G.H. Kusumadevi

2015-09-01

Full Text Available Transient overvoltages appearing at line terminal of power transformer HV windings can cause failure of winding insulation. The failure can be from winding to ground or between turns or sections of winding. In most of the cases, failure from winding to ground can be detected by changes in the wave shape of surge voltage appearing at line terminal. However, detection of insulation failure between turns may be difficult due to intricacies involved in identifications of faults. In this paper, simulation investigations carried out on a power transformer model winding for identifying faults between turns of winding has been reported. The power transformer HV winding has been represented by 8 sections, 16 sections and 24 sections. Neutral current waveform has been analyzed for same model winding represented by different number of sections. The values of α (‘α’ value is the square root of total ground capacitance to total series capacitance of winding considered for windings are 5, 10 and 20. Standard lightning impulse voltage (1.2/50 μs wave shape have been considered for analysis. Computer simulations have been carried out using software PSPICE version 10.0. Neutral current and frequency response analysis methods have been used for identification of faults within sections of transformer model winding.

The Indian power sector - Role of appellate tribunal

Energy Technology Data Exchange (ETDEWEB)

Bajaj, Harbans; Sharma, Deepak

2010-09-15

India's electricity-supply industry mainly owned and operated by the public sector has been facing endemic energy and peaking shortages with huge commercial losses. Power sector reforms initiated in 1990s culminated with enactment of The Electricity Act, 2003 is briefly discussed here. Appellate Tribunal for Electricity - a unique feature of the Act - constituted to redress grievances of stakeholders has set ground rules for the power sector having harmonizing effect on the various power sector issues and have reduced the element of uncertainty which was prevalent hitherto fore as revealed by the several case studies this paper presents.

UNISAT-3 Power System

Science.gov (United States)

Santoni, Fabio; Piergentili, Fabrizio; Bulgarelli, Fabio; Graziani, Filippo

2005-05-01

An overview of the UNISAT-3 microsatellite power subsystem is given. This is an educational, low weight and low cost microsatellite designed, built, launched and operated in space by students and professors of Scuola di Ingegneria Aerospaziale, at University of Rome "La Sapienza". The satellite power system is based on terrestrial technology solar arrays and NiCd batteries. The microsatellite hosts other solar arrays, including multi-junction solar cells and mono- crystalline silicon high efficiency solar cells, in order to compare their behaviour in orbit. Moreover a MPPT (Maximum Power Point Tracking ) system has been designed and tested, and it is a technological payload of UNISAT-3. The MPPT design follows the studies performed in the field of solar powered racing cars, with modifications to make the system suitable for use in space. The system design, numerical simulation and hardware ground testing are described in the paper. The experiment and the performance evaluation criterion are described, together with the preliminary results of the first eight months of operation in orbit.

Electrochemical stabilization of clayey ground

Science.gov (United States)

Rzhanitzin, B.A.; Sokoloff, V.P.

1947-01-01

Recently developed new methods of stabilization of weak grounds (e.g. the silicate treatment) are based on injection of chemical solutions into the ground. Such methods are applicable accordingly only to the kinds of ground that have the coefficient of filtration higher than 2 meters per 24 hours and permit penetration of the chemical solutions under pressure. This limit, however, as it is shown by our experience in construction, excludes a numerous and an important class of grounds, stabilization of which is indispensable in many instances. For example, digging of trenches and pits in clayey, silty, or sandy ground shows that all these types act like typical "floaters" (sluds? -S) in the presence of the ground water pressure. There were several instances in the canalization of the city of Moskow where the laying of trenches below the ground water level has led to extreme difficulties with clayey and silty ground. Similar examples could be cited in mining, engineering hydrology, and railroad construction. For these reasons, the development of methods of stabilizing such difficult types of ground has become an urgent problem of our day. In 1936, the author began his investigations, at the ground Stabilization Laboratory of VODGEO Institute, with direct electrical current as the means of stabilization of grounds. Experiments had shown that a large number of clayey types, following passage of direct electrical current, undergoes a transformation of its physico-chemical properties. It was established that the (apparent -S) density of the ground is substantially increased in consequence of the application of direct electrical current. The ground loses also its capacity to swell and to soften in water. Later, after a more detailed study of the physico-chemical mechanism of the electrical stabilization, it became possible to develop the method so as to make it applicable to sandy and silty as well as to clayey ground. By this time (1941, S.), the method has already been

A numerical study on the allowed sulpher content in fuel used by the power stations in Kuwait

International Nuclear Information System (INIS)

Ramadan, A. A.; AlsSdairawi, M.; AlHajraf, S.

2006-01-01

In Kuwait, most of the power stations use fuel oil as the prime source of energy. The sulphur content (S%) of the fuel used as well as other factors have a direct impact on the ground level concentration of sulphur dioxide (SO 2 ) released by the power stations into the atmosphere. The SO 2 ground level concentration has to meet the standards set by Kuwait Environmental Public Authority (KEPA). In this communication we present numerical results obtained using the Inustrial Sources Complex Short Team (ISC-ST) numerical model. The model calculated the SO 2 concentration resulting from existing power stations assuming a) zero background SO 2 concentration and b) entire reliance on Heavy Fuel Oil (HFO). Different scenarios represented by different S and, i.e. 0.5, 0.75, 1, 1.5, 2, 3, and 4% were simulated. For all power stations, the annual SO 2 concentrations for fuels with low sulphur content do not pose any risk on urban populations. Bubyan Islan and Subiya are considred ideal locations for future power stations. The majority of the pollutants around Kuwait City results from emissions from Doha East and Doha West power stations. The results are expected to benefit Kuwait Petroleum Corporation in improving the quality of the fuel produced for consumption by the power stations in Kuwait in order to maintain an acceptable ground level of SO 2 .(Author)

Evaluation of System Architectures for the Army Aviation Ground Power Unit

Science.gov (United States)

2014-12-01

air cycle machine fed by APU compressor bleed air to provide avionics cooling, so the AGPU was required to provide pneumatic power simultaneous with...broad categories of compressors : positive displacement and aerodynamic. Of the positive displacement compressors , reciprocating, rotary screw , and... compressor the single stage piston and the rot:aiy screw compressors are best suited. The rotmy screw machines m·e close tolerance complicated machines

There is need in new generation smart grid for the space and ground energy systems

Directory of Open Access Journals (Sweden)

Ageev Alexander

2018-01-01

Full Text Available The aim of the article is to considerate the opportunities of synchronization of the space and ground systems that generate and transfer energy on the basis of new generation smart grid using. The authors substantiate the necessity of new intellectual monitoring services that assess the processes took place in "generation-transportation-distribution-consumption" space and ground systems. This is made in order to improve the dynamic indicators of the energy system and to avoid the emergencies. The authors also give a prognosis of the dynamic indicators of the electric power super-system in analyzing metastable conditions in different energy modes.

Automation technology for aerospace power management

Science.gov (United States)

Larsen, R. L.

1982-01-01

The growing size and complexity of spacecraft power systems coupled with limited space/ground communications necessitate increasingly automated onboard control systems. Research in computer science, particularly artificial intelligence has developed methods and techniques for constructing man-machine systems with problem-solving expertise in limited domains which may contribute to the automation of power systems. Since these systems perform tasks which are typically performed by human experts they have become known as Expert Systems. A review of the current state of the art in expert systems technology is presented, and potential applications in power systems management are considered. It is concluded that expert systems appear to have significant potential for improving the productivity of operations personnel in aerospace applications, and in automating the control of many aerospace systems.

Implications of male circumcision for women in Papua New Guinea: a transformational grounded theory study.

Science.gov (United States)

Redman-MacLaren, Michelle; Mills, Jane; Tommbe, Rachael; MacLaren, David; Speare, Rick; McBride, William J H

2017-07-27

theory presents the core category as Power of Choice. This transformational grounded theory provides a means to explore how women experience male circumcision and penile modification in PNG, including for HIV prevention. Women who have had opportunities for education have a greater range of choices and an increased opportunity to act upon these choices. However, women can only exercise their power of choice in the context of safety. The concept of Peace drawn from the Social Determinants of Health is applied in order to extend the explanatory power of the transformational grounded theory. This study shows that women's ambivalence about male circumcision is often related to lack of safety, a consequence of gender inequality in PNG.

Virtualization - A Key Cost Saver in NASA Multi-Mission Ground System Architecture

Science.gov (United States)

Swenson, Paul; Kreisler, Stephen; Sager, Jennifer A.; Smith, Dan

2014-01-01

With science team budgets being slashed, and a lack of adequate facilities for science payload teams to operate their instruments, there is a strong need for innovative new ground systems that are able to provide necessary levels of capability processing power, system availability and redundancy while maintaining a small footprint in terms of physical space, power utilization and cooling.The ground system architecture being presented is based off of heritage from several other projects currently in development or operations at Goddard, but was designed and built specifically to meet the needs of the Science and Planetary Operations Control Center (SPOCC) as a low-cost payload command, control, planning and analysis operations center. However, this SPOCC architecture was designed to be generic enough to be re-used partially or in whole by other labs and missions (since its inception that has already happened in several cases!)The SPOCC architecture leverages a highly available VMware-based virtualization cluster with shared SAS Direct-Attached Storage (DAS) to provide an extremely high-performing, low-power-utilization and small-footprint compute environment that provides Virtual Machine resources shared among the various tenant missions in the SPOCC. The storage is also expandable, allowing future missions to chain up to 7 additional 2U chassis of storage at an extremely competitive cost if they require additional archive or virtual machine storage space.The software architecture provides a fully-redundant GMSEC-based message bus architecture based on the ActiveMQ middleware to track all health and safety status within the SPOCC ground system. All virtual machines utilize the GMSEC system agents to report system host health over the GMSEC bus, and spacecraft payload health is monitored using the Hammers Integrated Test and Operations System (ITOS) Galaxy Telemetry and Command (TC) system, which performs near-real-time limit checking and data processing on the

Construction of ground-state preserving sparse lattice models for predictive materials simulations

Science.gov (United States)

Huang, Wenxuan; Urban, Alexander; Rong, Ziqin; Ding, Zhiwei; Luo, Chuan; Ceder, Gerbrand

2017-08-01

First-principles based cluster expansion models are the dominant approach in ab initio thermodynamics of crystalline mixtures enabling the prediction of phase diagrams and novel ground states. However, despite recent advances, the construction of accurate models still requires a careful and time-consuming manual parameter tuning process for ground-state preservation, since this property is not guaranteed by default. In this paper, we present a systematic and mathematically sound method to obtain cluster expansion models that are guaranteed to preserve the ground states of their reference data. The method builds on the recently introduced compressive sensing paradigm for cluster expansion and employs quadratic programming to impose constraints on the model parameters. The robustness of our methodology is illustrated for two lithium transition metal oxides with relevance for Li-ion battery cathodes, i.e., Li2xFe2(1-x)O2 and Li2xTi2(1-x)O2, for which the construction of cluster expansion models with compressive sensing alone has proven to be challenging. We demonstrate that our method not only guarantees ground-state preservation on the set of reference structures used for the model construction, but also show that out-of-sample ground-state preservation up to relatively large supercell size is achievable through a rapidly converging iterative refinement. This method provides a general tool for building robust, compressed and constrained physical models with predictive power.

Early Site Permit Demonstration Program: Guidelines for determining design basis ground motions

International Nuclear Information System (INIS)

1993-01-01

This report develops and applies a methodology for estimating strong earthquake ground motion. The motivation was to develop a much needed tool for use in developing the seismic requirements for structural designs. An earthquake's ground motion is a function of the earthquake's magnitude, and the physical properties of the earth through which the seismic waves travel from the earthquake fault to the site of interest. The emphasis of this study is on ground motion estimation in Eastern North America (east of the Rocky Mountains), with particular emphasis on the Eastern United States and southeastern Canada. Eastern North America is a stable continental region, having sparse earthquake activity with rare occurrences of large earthquakes. While large earthquakes are of interest for assessing seismic hazard, little data exists from the region to empirically quantify their effects. Therefore, empirically based approaches that are used for other regions, such as Western North America, are not appropriate for Eastern North America. Moreover, recent advances in science and technology have now made it possible to combine theoretical and empirical methods to develop new procedures and models for estimating ground motion. The focus of the report is on the attributes of ground motion in Eastern North America that are of interest for the design of facilities such as nuclear power plants. Specifically considered are magnitudes M from 5 to 8, distances from 0 to 500 km, and frequencies from 1 to 35 Hz

PEER NGA-East Overview: Development of a Ground Motion Characterization Model (Ground Motion Prediction Equations) for Central and Eastern North America

Science.gov (United States)

Goulet, C. A.; Abrahamson, N. A.; Al Atik, L.; Atkinson, G. M.; Bozorgnia, Y.; Graves, R. W.; Kuehn, N. M.; Youngs, R. R.

2017-12-01

The Next Generation Attenuation project for Central and Eastern North America (CENA), NGA-East, is a major multi-disciplinary project coordinated by the Pacific Earthquake Engineering Research Center (PEER). The project was co-sponsored by the U.S. Nuclear Regulatory Commission (NRC), the U.S. Department of Energy (DOE), the Electric Power Research Institute (EPRI) and the U.S. Geological Survey (USGS). NGA-East involved a large number of participating researchers from various organizations in academia, industry and government and was carried-out as a combination of 1) a scientific research project and 2) a model-building component following the NRC Seismic Senior Hazard Analysis Committee (SSHAC) Level 3 process. The science part of the project led to several data products and technical reports while the SSHAC component aggregated the various results into a ground motion characterization (GMC) model. The GMC model consists in a set of ground motion models (GMMs) for median and standard deviation of ground motions and their associated weights, combined into logic-trees for use in probabilistic seismic hazard analyses (PSHA). NGA-East addressed many technical challenges, most of them related to the relatively small number of earthquake recordings available for CENA. To resolve this shortcoming, the project relied on ground motion simulations to supplement the available data. Other important scientific issues were addressed through research projects on topics such as the regionalization of seismic source, path and attenuation of motions, the treatment of variability and uncertainties and on the evaluation of site effects. Seven working groups were formed to cover the complexity and breadth of topics in the NGA-East project, each focused on a specific technical area. This presentation provides an overview of the NGA-East research project and its key products.

30 CFR 75.803 - Fail safe ground check circuits on high-voltage resistance grounded systems.

Science.gov (United States)

2010-07-01

... High-Voltage Distribution § 75.803 Fail safe ground check circuits on high-voltage resistance grounded systems. [Statutory Provisions] On and after September 30, 1970, high-voltage, resistance grounded systems... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Fail safe ground check circuits on high-voltage...

Solar Power Tower Design Basis Document, Revision 0

Energy Technology Data Exchange (ETDEWEB)

ZAVOICO,ALEXIS B.

2001-07-01

This report contains the design basis for a generic molten-salt solar power tower. A solar power tower uses a field of tracking mirrors (heliostats) that redirect sunlight on to a centrally located receiver mounted on top a tower, which absorbs the concentrated sunlight. Molten nitrate salt, pumped from a tank at ground level, absorbs the sunlight, heating it up to 565 C. The heated salt flows back to ground level into another tank where it is stored, then pumped through a steam generator to produce steam and make electricity. This report establishes a set of criteria upon which the next generation of solar power towers will be designed. The report contains detailed criteria for each of the major systems: Collector System, Receiver System, Thermal Storage System, Steam Generator System, Master Control System, and Electric Heat Tracing System. The Electric Power Generation System and Balance of Plant discussions are limited to interface requirements. This design basis builds on the extensive experience gained from the Solar Two project and includes potential design innovations that will improve reliability and lower technical risk. This design basis document is a living document and contains several areas that require trade-studies and design analysis to fully complete the design basis. Project- and site-specific conditions and requirements will also resolve open To Be Determined issues.

A low-power microcontroller in a 40-nm CMOS using charge recycling

NARCIS (Netherlands)

Blutman, K.; Kapoor, A.; Majumdar, A.; Martinez, J.G.; Echeverri, J.; Sevat, L.; Van Der Wel, A.P.; Fatemi, H.; Makinwa, K.A.A; De Gyvez, J.P.

2017-01-01

A 40-nm microcontroller featuring voltage stacked memory and logic is presented. This involved connecting the power domains of the memory and logic in series, such that the ground of one power domain is connected to the positive supply rail of the other. In this paper, an ARM Cortex-M0+ and its

Ground rubber: Sorption media for ground water containing benzene and O-xylene

International Nuclear Information System (INIS)

Kershaw, D.S.; Pamukcu, S.

1997-01-01

The purpose of the current study is to examine the ability of ground rubber to sorb benzene and O-xylene from water contained with aromatic hydrocarbons. The study consisted of running both batch and packed bed column tests to determine the sorption capacity, the required sorption equilibration time, and the flow through utilization efficiency of ground rubber under various contact times when exposed to water contaminated with various amounts of benzene or O-xylene. Initial batch test results indicate that ground rubber can attain equilibrium sorption capacities up to 1.3 or 8.2 mg of benzene or O-xylene, respectively, per gram of tire rubber at solution equilibrium concentrations of 10 mg/L. Packed bed column tests indicate that ground tire rubber has on the average a 40% utilization rate when a hydraulic residence time of 15 min is used. Possible future uses of round rubber as a sorption media could include, but are not limited to, the use of ground rubber as an aggregate in slurry cutoff walls that are in contact with petroleum products. Ground rubber could also be used as a sorption media in pump-and-treat methodologies or as a sorption media in in-situ reactive permeable barriers

Extreme earthquake response of nuclear power plants isolated using sliding bearings

Energy Technology Data Exchange (ETDEWEB)

Kumar, Manish, E-mail: mkumar@iitgn.ac.in [Department of Civil Engineering, Indian Institute of Technology Gandhinagar, Gandhinagar 382355 (India); Whittaker, Andrew S.; Constantinou, Michael C. [Department of Civil, Structural and Environmental Engineering, University at Buffalo, Buffalo, NY 14260 (United States)

2017-05-15

Highlights: • Response-history analysis of a nuclear power plant (NPP) isolated using sliding bearings. • Two models of the NPP, five friction models and four seismic hazard levels considered. • Isolation system displacement can be obtained using a macro NPP model subjected to only horizontal ground motions. • Temperature dependence of friction should be considered in isolation-system displacement calculations. • The effect of friction model on floor spectral ordinates is rather small, especially near the basemat. - Abstract: Horizontal seismic isolation is a viable approach to mitigate risk to structures, systems and components (SSCs) in nuclear power plants (NPPs) under extreme ground shaking. This paper presents a study on an NPP seismically isolated using single concave Friction Pendulum™ (FP) bearings subjected to ground motions representing seismic hazard at two US sites: Diablo Canyon and Vogtle. Two models of the NPP, five models to describe friction at the sliding surface of the FP bearings, and four levels of ground shaking are considered for response-history analysis, which provide insight into the influence of 1) the required level of detail of an NPP model, 2) the vertical component of ground motion on response of isolated NPPs, and 3) the pressure-, temperature- and/or velocity-dependencies of the coefficient of friction, on the response of an isolated NPP. The isolation-system displacement of an NPP can be estimated using a macro model subjected to only the two orthogonal horizontal components of ground motion. The variation of the coefficient of friction with temperature at the sliding surface during earthquake shaking should be accounted for in the calculation of isolation-system displacements, particularly when the shaking intensity is high; pressure and velocity dependencies are not important. In-structure floor spectra should be computed using a detailed three-dimensional model of an isolated NPP subjected to all three components of

Early Site Permit Demonstration Program: Guidelines for determining design basis ground motions

International Nuclear Information System (INIS)

1993-01-01

This report develops and applies a methodology for estimating strong earthquake ground motion. The motivation was to develop a much needed tool for use in developing the seismic requirements for structural designs. An earthquake's ground motion is a function of the earthquake's magnitude, and the physical properties of the earth through which the seismic waves travel from the earthquake fault to the site of interest. The emphasis of this study is on ground motion estimation in Eastern North America (east of the Rocky Mountains), with particular emphasis on the Eastern United States and southeastern Canada. Eastern North America is a stable continental region, having sparse earthquake activity with rare occurrences of large earthquakes. While large earthquakes are of interest for assessing seismic hazard, little data exists from the region to empirically quantify their effects. The focus of the report is on the attributes of ground motion in Eastern North America that are of interest for the design of facilities such as nuclear power plants. This document, Volume II, contains Appendices 2, 3, 5, 6, and 7 covering the following topics: Eastern North American Empirical Ground Motion Data; Examination of Variance of Seismographic Network Data; Soil Amplification and Vertical-to-Horizontal Ratios from Analysis of Strong Motion Data From Active Tectonic Regions; Revision and Calibration of Ou and Herrmann Method; Generalized Ray Procedure for Modeling Ground Motion Attenuation; Crustal Models for Velocity Regionalization; Depth Distribution Models; Development of Generic Site Effects Model; Validation and Comparison of One-Dimensional Site Response Methodologies; Plots of Amplification Factors; Assessment of Coupling Between Vertical ampersand Horizontal Motions in Nonlinear Site Response Analysis; and Modeling of Dynamic Soil Properties

Mitigative techniques and analysis of generic site conditions for ground-water contamination associated with severe accidents

Energy Technology Data Exchange (ETDEWEB)

Shafer, J.M.; Oberlander, P.L.; Skaggs, R.L.

1984-04-01

The purpose of this study is to evaluate the feasibility of using ground-water contaminant mitigation techniques to control radionuclide migration following a severe commercial nuclear power reactor accident. The two types of severe commercial reactor accidents investigated are: (1) containment basemat penetration of core melt debris which slowly cools and leaches radionuclides to the subsurface environment, and (2) containment basemat penetration of sump water without full penetration of the core mass. Six generic hydrogeologic site classifications are developed from an evaluation of reported data pertaining to the hydrogeologic properties of all existing and proposed commercial reactor sites. One-dimensional radionuclide transport analyses are conducted on each of the individual reactor sites to determine the generic characteristics of a radionuclide discharge to an accessible environment. Ground-water contaminant mitigation techniques that may be suitable, depending on specific site and accident conditions, for severe power plant accidents are identified and evaluated. Feasible mitigative techniques and associated constraints on feasibility are determined for each of the six hydrogeologic site classifications. The first of three case studies is conducted on a site located on the Texas Gulf Coastal Plain. Mitigative strategies are evaluated for their impact on contaminant transport and results show that the techniques evaluated significantly increased ground-water travel times. 31 references, 118 figures, 62 tables.

Mitigative techniques and analysis of generic site conditions for ground-water contamination associated with severe accidents

International Nuclear Information System (INIS)

Shafer, J.M.; Oberlander, P.L.; Skaggs, R.L.

1984-04-01

The purpose of this study is to evaluate the feasibility of using ground-water contaminant mitigation techniques to control radionuclide migration following a severe commercial nuclear power reactor accident. The two types of severe commercial reactor accidents investigated are: (1) containment basemat penetration of core melt debris which slowly cools and leaches radionuclides to the subsurface environment, and (2) containment basemat penetration of sump water without full penetration of the core mass. Six generic hydrogeologic site classifications are developed from an evaluation of reported data pertaining to the hydrogeologic properties of all existing and proposed commercial reactor sites. One-dimensional radionuclide transport analyses are conducted on each of the individual reactor sites to determine the generic characteristics of a radionuclide discharge to an accessible environment. Ground-water contaminant mitigation techniques that may be suitable, depending on specific site and accident conditions, for severe power plant accidents are identified and evaluated. Feasible mitigative techniques and associated constraints on feasibility are determined for each of the six hydrogeologic site classifications. The first of three case studies is conducted on a site located on the Texas Gulf Coastal Plain. Mitigative strategies are evaluated for their impact on contaminant transport and results show that the techniques evaluated significantly increased ground-water travel times. 31 references, 118 figures, 62 tables

Local spectral anisotropy is a valid cue for figure-ground organization in natural scenes.

Science.gov (United States)

Ramenahalli, Sudarshan; Mihalas, Stefan; Niebur, Ernst

2014-10-01

An important step in the process of understanding visual scenes is its organization in different perceptual objects which requires figure-ground segregation. The determination of which side of an occlusion boundary is figure (closer to the observer) and which is ground (further away from the observer) is made through a combination of global cues, like convexity, and local cues, like T-junctions. We here focus on a novel set of local cues in the intensity patterns along occlusion boundaries which we show to differ between figure and ground. Image patches are extracted from natural scenes from two standard image sets along the boundaries of objects and spectral analysis is performed separately on figure and ground. On the figure side, oriented spectral power orthogonal to the occlusion boundary significantly exceeds that parallel to the boundary. This "spectral anisotropy" is present only for higher spatial frequencies, and absent on the ground side. The difference in spectral anisotropy between the two sides of an occlusion border predicts which is the figure and which the background with an accuracy exceeding 60% per patch. Spectral anisotropy of close-by locations along the boundary co-varies but is largely independent over larger distances which allows to combine results from different image regions. Given the low cost of this strictly local computation, we propose that spectral anisotropy along occlusion boundaries is a valuable cue for figure-ground segregation. A data base of images and extracted patches labeled for figure and ground is made freely available. Copyright © 2014 Elsevier Ltd. All rights reserved.

NASA Planning for Orion Multi-Purpose Crew Vehicle Ground Operations

Science.gov (United States)

Letchworth, Gary; Schlierf, Roland

2011-01-01

The NASA Orion Ground Processing Team was originally formed by the Kennedy Space Center (KSC) Constellation (Cx) Project Office's Orion Division to define, refine and mature pre-launch and post-landing ground operations for the Orion human spacecraft. The multidisciplined KSC Orion team consisted of KSC civil servant, SAIC, Productivity Apex, Inc. and Boeing-CAPPS engineers, project managers and safety engineers, as well as engineers from Constellation's Orion Project and Lockheed Martin Orion Prime contractor. The team evaluated the Orion design configurations as the spacecraft concept matured between Systems Design Review (SDR), Systems Requirement Review (SRR) and Preliminary Design Review (PDR). The team functionally decomposed prelaunch and post-landing steps at three levels' of detail, or tiers, beginning with functional flow block diagrams (FFBDs). The third tier FFBDs were used to build logic networks and nominal timelines. Orion ground support equipment (GSE) was identified and mapped to each step. This information was subsequently used in developing lower level operations steps in a Ground Operations Planning Document PDR product. Subject matter experts for each spacecraft and GSE subsystem were used to define 5th - 95th percentile processing times for each FFBD step, using the Delphi Method. Discrete event simulations used this information and the logic network to provide processing timeline confidence intervals for launch rate assessments. The team also used the capabilities of the KSC Visualization Lab, the FFBDs and knowledge of the spacecraft, GSE and facilities to build visualizations of Orion pre-launch and postlanding processing at KSC. Visualizations were a powerful tool for communicating planned operations within the KSC community (i.e., Ground Systems design team), and externally to the Orion Project, Lockheed Martin spacecraft designers and other Constellation Program stakeholders during the SRR to PDR timeframe. Other operations planning

Earthquakes and associated topics in relation to nuclear power plant siting

International Nuclear Information System (INIS)

1979-01-01

The main emphasis of the Guide is on the determination of the design basis ground motions for the nuclear power plant and on the determination of the potential for surface faulting at the site. Additionally, the Guide treats initiation of seismically induced flooding and the ground failure phenomena of subsidence and collapse. Volcanic activity is not dealt with except in connection with tsunamis. The methods and procedures discussed in this Guide should be taken as the basis for the design of seismically safe nuclear power plants and are primarily suited to areas of high and medium seismicity; for areas of low seismicity the Guide may not be applicable in its entirety and may need to be supplemented by other methods

Transitions in midwestern ground water law

International Nuclear Information System (INIS)

Bowman, J.A.; Clark, G.R.

1989-01-01

The evolution of ground-water law in eight states in the Midwest (Illinois, Indiana, Iowa, Michigan, Minnesota, Missouri, Ohio, and Wisconsin) is examined, and a review of transitions in ground-water doctrines is presented. Two underlying themes in changing ground-water management are communicated. First, ground-water law is evolving from private property rules of capture based on the absolute ownership doctrines to rules requiring conservation and sharing of ground water as a public resource. Second, in both courts and state legislatures, a proactive role of ground-water management is emerging, again, with an emphasis on sharing. Both of these trends are apparent in the Midwest. In the last decade midwestern states have (1) seen significant shifts in court decisions on ground-water use with greater recognition of the reciprocal or mutually dependent nature of ground-water rights, and (2) seen increased legislative development of comprehensive ground-water management statutes that emphasize the reciprocal liabilities of ground-water use. These trends are examined and ground-water management programs discussed for eight states in the Midwest

Research on advancement of technique for assessing ground seismic intensity

International Nuclear Information System (INIS)

Tamura, Keiichi; Kaneko, Masahiro; Honda, Riki; Tabuchi, Yoshihiro

1997-01-01

In the aseismatic design of nuclear power stations, as the characteristics of earthquake motion inputted in released base surface, the maximum amplitude and the frequency characteristics of earthquake motion, the presumption of earthquake motion using fault model, the time of continuation and the change of amplitude envelope with time are to be examined. In this research, in order to upgrade the earthquake motion used for aseismatic design, the method of evaluating quantitatively the amplifying characteristics of earthquake motion in unfair ground and the technique of setting design earthquake motion that can consider the change of structural state were investigated. The course of the research carried out so far is outlined. As to the amplifying characteristics of earthquake motion in unfair ground, the technique of analysis, the index showing the degree of amplifying of earthquake motion, the index showing the degree of unfairness of ground, the amplifying characteristics of earthquake motion in tray type base, and the evaluation of frequency zone of large degree of amplifying are reported. As to the design earthquake motion taking the plasticizing of structures in consideration, the analysis condition, the equivalent peculiar frequency and the equivalent damping constant and the design earthquake motion taking the plasticizing of structures in consideration are reported. (K.I.)

Hovering performance of Anna's hummingbirds (Calypte anna) in ground effect.

Science.gov (United States)

Kim, Erica J; Wolf, Marta; Ortega-Jimenez, Victor Manuel; Cheng, Stanley H; Dudley, Robert

2014-09-06

Aerodynamic performance and energetic savings for flight in ground effect are theoretically maximized during hovering, but have never been directly measured for flying animals. We evaluated flight kinematics, metabolic rates and induced flow velocities for Anna's hummingbirds hovering at heights (relative to wing length R = 5.5 cm) of 0.7R, 0.9R, 1.1R, 1.7R, 2.2R and 8R above a solid surface. Flight at heights less than or equal to 1.1R resulted in significant reductions in the body angle, tail angle, anatomical stroke plane angle, wake-induced velocity, and mechanical and metabolic power expenditures when compared with flight at the control height of 8R. By contrast, stroke plane angle relative to horizontal, wingbeat amplitude and wingbeat frequency were unexpectedly independent of height from ground. Qualitative smoke visualizations suggest that each wing generates a vortex ring during both down- and upstroke. These rings expand upon reaching the ground and present a complex turbulent interaction below the bird's body. Nonetheless, hovering near surfaces results in substantial energetic benefits for hummingbirds, and by inference for all volant taxa that either feed at flowers or otherwise fly close to plant or other surfaces. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Solution of electric power quality problems by troika cooperation

International Nuclear Information System (INIS)

Khan, N.; Ahmad, M.I.

1999-01-01

Power quality is a growing concern effecting utility supply continuity, sensitivity customer productivity and manufacturer equipment. Power quality problems such as voltage sags, swells, distortions and transient surges caused by short circuit faults or motor starting, switching reactive loads or phase to ground faults. VSD or arcing loads and inductive or capacity load switching may result in process shutdown or contactor dropout, under voltage tripping and speed drift or ASD tripping. This work describes results of a power quality study concluding urgent need for enhancing cooperation between utilities, customers and manufactures to improve power quality problems. Individual responsibilities of utilities personnel, sensitive equipment customers and power equipment manufacturers in light of available power conditioning technology, regarding deployment of equipment and improvement of design strategies have been discussed for precious end users. (authors)

Potential effects of the Hawaii Geothermal Project on ground-water resources on the island of Hawaii

Science.gov (United States)

Sorey, M.L.; Colvard, E.M.

1994-01-01

In 1990, the State of Hawaii proposed the Hawaii Geothermal Project for the development of as much as 500 MW of electric power from the geothermal system in the East Rift Zone of Kilauea Volcano. This report uses data from 31 wells and 8 springs to describe the properties of the ground-water system in and adjacent to the East Rift Zone. Potential effects of this project on ground-water resources are also discussed. Data show differences in ground-water chemistry and heads within the study area that appear to be related to mixing of waters of different origins and ground-water impoundment by volcanic dikes. East of Pahoa, the ground-water system within the rift is highly transmissive and receives abundant recharge from precipitation; therefore, the pumping of freshwater to support geothermal development in that part of the rift zone would have a minimal effect on ground-water levels. To the southwest of Pahoa, dike impoundment reduces the transmissivity of the ground-water system to such an extent that wells might not be capable of supplying sufficient fresh water to support geothermal operations. Contamination of ground-water resources by accidental release of geothermal fluids into shallow aquifers is possible because of corrosive conditions in the geothermal wells, potential well blowouts, and high ground-water velocities in parts of the region. Hydrologic monitoring of water level, temperature, and chemistry in observation wells should continue throughout development of geothermal resources for the Hawaii Geothermal Project for early detection of leakage and migration of geothermal fluids within the groundwater system.

Engineering Design of the ITER AC/DC Power Supplies

International Nuclear Information System (INIS)

Oh, B. H.; Lee, K. W.; Hwang, C. K.; Jin, J. T.; Chang, D. S.; Kim, T. S.

2009-02-01

To design high power pulse power supplies, especially in huge power supplies have not designed till now, it is necessary to analyze a system's characteristics and relations with another systems as well as to know high voltage, high current control technologies. Contents of this project are; - Study for the engineering designs changed recently by ITER Organization(IO) and writing specifications for the power supplies to reduce project risk. - Detailed analysis of the AC/DC Converters and writing subtask reports on the Task Agreement. - Study for thyristor numbers, DCR's specifications for Korea-China sharing meetings. - Study for the grounding systems of the ITER power supply system. The results may used as one of reference for practical designs of the high power coil power supplies and also may used in various field such as electroplating, plasma arc furnaces, electric furnaces

The effects of altering initial ground contact in the running gait of an individual with transtibial amputation.

Science.gov (United States)

Waetjen, Linda; Parker, Matthew; Wilken, Jason M

2012-09-01

High rates of osteoarthritis of the knee joint of the intact limb in persons with amputation have raised concern about the long-term consequence of running. The purpose of this intervention was to determine if loading of the knee on the intact limb of a person with transtibial amputation during running could be decreased by changing the intact limb initial ground contact from rear foot to forefoot strike. This study compared kinematic, kinetic and temporal-spatial data collected while a 27-year-old male, who sustained a traumatic unilateral transtibial amputation of the left lower extremity, ran using a forefoot ground contact and again while using a heel first ground contact. Changing initial ground contact from rear foot strike to forefoot strike resulted in decreases in vertical ground reaction forces at impact, peak knee moments in stance, peak knee powers, and improved symmetry in step length. This case suggests forefoot initial contact of the intact limb may minimize loading of the knee on the intact limb in individuals with transtibial amputation.

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.

Using XML Configuration-Driven Development to Create a Customizable Ground Data System

Science.gov (United States)

Nash, Brent; DeMore, Martha

2009-01-01

The Mission data Processing and Control Subsystem (MPCS) is being developed as a multi-mission Ground Data System with the Mars Science Laboratory (MSL) as the first fully supported mission. MPCS is a fully featured, Java-based Ground Data System (GDS) for telecommand and telemetry processing based on Configuration-Driven Development (CDD). The eXtensible Markup Language (XML) is the ideal language for CDD because it is easily readable and editable by all levels of users and is also backed by a World Wide Web Consortium (W3C) standard and numerous powerful processing tools that make it uniquely flexible. The CDD approach adopted by MPCS minimizes changes to compiled code by using XML to create a series of configuration files that provide both coarse and fine grained control over all aspects of GDS operation.

Advanced power supply and distribution systems for Columbus

Science.gov (United States)

Eggers, Gert

1988-01-01

The paper describes power supply and distribution systems to be used on unmanned/man-tended Columbus elements, capable of supplying 10 kW to 30 kW to a variety of users in low earth orbits (LEO's). For the definition of the Electrical Power System (EPS) challenging requirements as the provision of high power levels under hard LEO conditions, maintainability, commonality etc. are to be taken into account. These requirements are to be seen in conjunction with the Columbus IOC (initial operational capability) scenario stipulating that EPS hardware shall be used on the Polar Platform, the Pressurized Module attached to the U.S. Space Station and the Man-Tended Free Flier. According to the availability of European technologies, the baseline in the power generation area is a photovoltaic system which provides three regulated main buses (150 V d.c.) to the users. In order to maintain power supply during eclipse phases, nickel hydrogen batteries will be used for energy storage purposes with nickel cadmium as back-up solution. The power distribution system needs special attention. Due to the elevated voltage levels mechanical switch gear cannot be used any longer. It is to be replaced by solid state power controllers (SSPC). Because these devices show a totally different behaviour with regard to conventional relay contacts, new approaches in the area of switching and protection are necessary. In view of the crucial role of this new technology for the realization of medium voltage d.c. systems, it is of great importance for Columbus and, hence will receive adequate consideration in the paper. In order to cater for effective management and control of the power supply and distribution hardware, a so called power system internal data processing assembly (PINDAP) has been introduced in the EPS. PINDAP is the key to reduced dependence on ground stations (alleviated ground support requirements); it keeps crew involvement in the EPS control process to as minimum and provides

Saturn V First Stage Lowered to the Ground After Static Test

Science.gov (United States)

1966-01-01

This vintage photograph shows the 138-foot long first stage of the Saturn V being lowered to the ground following a successful static test firing at Marshall Space flight Center's S-1C test stand. The firing provided NASA engineers information on the booster's systems. The towering 363-foot Saturn V was a multi-stage, multi-engine launch vehicle standing taller than the Statue of Liberty. Altogether, the Saturn V engines produced as much power as 85 Hoover Dams.

Grounded theory in music therapy research.

Science.gov (United States)

O'Callaghan, Clare

2012-01-01

Grounded theory is one of the most common methodologies used in constructivist (qualitative) music therapy research. Researchers use the term "grounded theory" when denoting varying research designs and theoretical outcomes. This may be challenging for novice researchers when considering whether grounded theory is appropriate for their research phenomena. This paper examines grounded theory within music therapy research. Grounded theory is briefly described, including some of its "contested" ideas. A literature search was conducted using the descriptor "music therapy and grounded theory" in Pubmed, CINAHL PsychlNFO, SCOPUS, ERIC (CSA), Web of Science databases, and a music therapy monograph series. A descriptive analysis was performed on the uncovered studies to examine researched phenomena, grounded theory methods used, and how findings were presented, Thirty music therapy research projects were found in refereed journals and monographs from 1993 to "in press." The Strauss and Corbin approach to grounded theory dominates the field. Descriptors to signify grounded theory components in the studies greatly varied. Researchers have used partial or complete grounded theory methods to examine clients', family members', staff, music therapy "overhearers," music therapists', and students' experiences, as well as music therapy creative products and professional views, issues, and literature. Seven grounded theories were offered. It is suggested that grounded theory researchers clarify what and who inspired their design, why partial grounded theory methods were used (when relevant), and their ontology. By elucidating assumptions underpinning the data collection, analysis, and findings' contribution, researchers will continue to improve music therapy research using grounded theory methods.

Detection of arcing ground fault location on a distribution network connected PV system; Hikarihatsuden renkei haidensen ni okeru koko chiryaku kukan no kenshutsuho

Energy Technology Data Exchange (ETDEWEB)

Sato, M; Iwaya, K; Morooka, Y [Hachinohe Institute of Technology, Aomori (Japan)

1996-10-27

In the near future, it is supposed that a great number of small-scale distributed power sources, such as photovoltaic power generation for general houses, will be interconnected with the ungrounded neutral distribution system in Japan. When ground fault of commercial frequency once occurs, great damage is easily guessed. This paper discusses the effect of the ground fault on the ground phase current using a 6.6 kV high-voltage model system by considering the non-linear self-inductance in the line, and by considering the non-linear relation of arcing ground fault current frequency. In the present method, the remarkable difference of series resonance frequency determined by the inductance and earth capacity between the source side and load side is utilized for the detection of high-voltage arcing ground fault location. In this method, there are some cases in which the non-linear effect obtained by measuring the inductance of sound phase including the secondary winding of transformer can not be neglected. Especially, for the actual high-voltage system, it was shown that the frequency characteristics of transformer inductance for distribution should be theoretically derived in the frequency range between 2 kHz and 6 kHz. 2 refs., 5 figs., 1 tab.

Appeal on constitutional grounds against Muelheim-Kaerlich nuclear power plant dismissed

International Nuclear Information System (INIS)

Anon.

1980-01-01

On December 20, 1979 the Federal Constitutional Court dismissed an appeal against a decision by the Rheinland-Pfalz Higher Administrative Court, as of May 3rd, 1977, which at the time rescinded a decision to stop the construction of the Muehlheim-Kaerlich nuclear power plant. The essential reasons and principles underlying the decision to the Federal Constitutional Court (1 BvR 385/77) are given in fall. The dissentient opinion of two judges is also presented. (orig./HP) [de

High power neutral beam injection in LHD

International Nuclear Information System (INIS)

Tsumori, K.; Takeiri, Y.; Nagaoka, K.

2005-01-01

The results of high power injection with a neutral beam injection (NBI) system for the large helical device (LHD) are reported. The system consists of three beam-lines, and two hydrogen negative ion (H - ion) sources are installed in each beam-line. In order to improve the injection power, the new beam accelerator with multi-slot grounded grid (MSGG) has been developed and applied to one of the beam-lines. Using the accelerator, the maximum powers of 5.7 MW were achieved in 2003 and 2004, and the energy of 189 keV reached at maximum. The power and energy exceeded the design values of the individual beam-line for LHD. The other beam-lines also increased their injection power up to about 4 MW, and the total injection power of 13.1 MW was achieved with three beam-lines in 2003. Although the accelerator had an advantage in high power beam injection, it involved a demerit in the beam focal condition. The disadvantage was resolved by modifying the aperture shapes of the steering grid. (author)

Cooling water in the study of nuclear power plants sites

International Nuclear Information System (INIS)

Martinez, J.J.C.

1990-01-01

The location of an electric power plant has its limitations as regards the availability of apt sites. The radiosanitary risk, seismic risk and the overload capacity of the ground can be generically enumerated, being the cooling water availability for an electric power plant a basic requirement. Diverse cooling systems may be employed but the aim must always be that thermal contamination in the immediate environment be the least possible. (Author) [es

3D Power Line Extraction from Multiple Aerial Images

Directory of Open Access Journals (Sweden)

Jaehong Oh

2017-09-01

Full Text Available Power lines are cables that carry electrical power from a power plant to an electrical substation. They must be connected between the tower structures in such a way that ensures minimum tension and sufficient clearance from the ground. Power lines can stretch and sag with the changing weather, eventually exceeding the planned tolerances. The excessive sags can then cause serious accidents, while hindering the durability of the power lines. We used photogrammetric techniques with a low-cost drone to achieve efficient 3D mapping of power lines that are often difficult to approach. Unlike the conventional image-to-object space approach, we used the object-to-image space approach using cubic grid points. We processed four strips of aerial images to automatically extract the power line points in the object space. Experimental results showed that the approach could successfully extract the positions of the power line points for power line generation and sag measurement with the elevation accuracy of a few centimeters.

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. Copyright © 2014 Elsevier Ltd. All rights reserved.

Ground-water travel time

International Nuclear Information System (INIS)

Bentley, H.; Grisak, G.

1985-01-01

The Containment and Isolation Working Group considered issues related to the postclosure behavior of repositories in crystalline rock. This working group was further divided into subgroups to consider the progress since the 1978 GAIN Symposium and identify research needs in the individual areas of regional ground-water flow, ground-water travel time, fractional release, and cumulative release. The analysis and findings of the Ground-Water Travel Time Subgroup are presented

Regional ground-water system

International Nuclear Information System (INIS)

Long, J.

1985-01-01

The Containment and Isolation Working Group considered issues related to the postclosure behavior of repositories in crystalline rock. This working group was further divided into subgroups to consider the progress since the 1978 GAIN Symposium and identify research needs in the individual areas of regional ground-water flow, ground-water travel time, fractional release, and cumulative release. The analysis and findings of the Ground-Water Regime Subgroup are presented

Lightning current distribution to ground at a power line tower carrying a radio base station

NARCIS (Netherlands)

Grcev, L.; Deursen, van A.P.J.; Waes, van J.B.M.

2005-01-01

Radio base stations are often mounted on towers of power transmission lines. They are usually powered from the low-voltage network through an isolating transformer, to separate the high- and low-voltage networks. The isolating transformer ensures security at customers' premises in the case of nearby

Evaluation of high frequency ground motion effects on the seismic capacity of NPP equipments

International Nuclear Information System (INIS)

Choi, In Kil; Seo, Jeong Moon; Choun, Young Sun

2003-04-01

In this study, the uniform hazard spectrum for the example Korean nuclear power plants sites were developed and compared with various response spectra used in past seismic PRA and SMA. It shows that the high frequency ground motion effects should be considered in seismic safety evaluations. The floor response spectra were developed using the direct generation method that can develop the floor response spectra from the input response spectrum directly with only the dynamic properties of structures obtained from the design calculation. Most attachment of the equipments to the structure has a minimum distortion capacity. This makes it possible to drop the effective frequency of equipment to low frequency before it is severely damaged. The results of this study show that the high frequency ground motion effects on the floor response spectra were significant, and the effects should be considered in the SPRA and SMA for the equipments installed in a building. The high frequency ground motion effects are more important for the seismic capacity evaluation of functional failure modes. The high frequency ground motion effects on the structural failure of equipments that attached to the floor by welding can be reduced by the distortion capacity of welded anchorage

Ground fissures in the area of Mavropigi Village (N. Greece): Seismotectonics or mining activity?

Science.gov (United States)

Kalogirou, Eleni; Tsapanos, Theodoros; Karakostas, Vassilios; Marinos, Vassilios; Chatzipetros, Alexandros

2014-12-01

In the beginning of July 2010, a ground fissure was observed in the field near the village of Mavropigi (Northern Greece) and specifically in its NW side. Later on (early September), a second ground fissure was perceived, close and almost parallel to the first one and very close to the limits of the lignite exploitation mine (by the Public Power Corporation, PPC). It was observed that the village of Mavropigi slides away slowly towards the PPC lignite mine. Geological, seismological, as well as geotechnical survey in the field indicated that the phenomenon is related to the coal mining exploitation in the near vicinity of the village rather than to any seismotectonic activity in the surrounding area.

Integration of a satellite ground support system based on analysis of the satellite ground support domain

Science.gov (United States)

Pendley, R. D.; Scheidker, E. J.; Levitt, D. S.; Myers, C. R.; Werking, R. D.

1994-11-01

This analysis defines a complete set of ground support functions based on those practiced in real space flight operations during the on-orbit phase of a mission. These functions are mapped against ground support functions currently in use by NASA and DOD. Software components to provide these functions can be hosted on RISC-based work stations and integrated to provide a modular, integrated ground support system. Such modular systems can be configured to provide as much ground support functionality as desired. This approach to ground systems has been widely proposed and prototyped both by government institutions and commercial vendors. The combined set of ground support functions we describe can be used as a standard to evaluate candidate ground systems. This approach has also been used to develop a prototype of a modular, loosely-integrated ground support system, which is discussed briefly. A crucial benefit to a potential user is that all the components are flight-qualified, thus giving high confidence in their accuracy and reliability.

Dynamic energy converters using an outer heat source for ground uses. Bibliographic study

International Nuclear Information System (INIS)

Bousquet, Jean-Louis du

1969-01-01

This short bibliographical review presents the main dynamical conversion systems operating with an outer heat source, used for power ranges of a few hundreds Watts to a few hundreds kilowatts and dedicated to ground uses. The study has three parts: recollection of thermodynamic cycles; review of some present or projected realizations; a critical study for selecting converter components (turbine, reciprocating engine, thermodynamical fluid) [fr

Strong ground motion in the Kathmandu Valley during the 2015 Gorkha, Nepal, earthquake

Science.gov (United States)

Takai, Nobuo; Shigefuji, Michiko; Rajaure, Sudhir; Bijukchhen, Subeg; Ichiyanagi, Masayoshi; Dhital, Megh Raj; Sasatani, Tsutomu

2016-01-01

On 25 April 2015, a large earthquake of Mw 7.8 occurred along the Main Himalayan Thrust fault in central Nepal. It was caused by a collision of the Indian Plate beneath the Eurasian Plate. The epicenter was near the Gorkha region, 80 km northwest of Kathmandu, and the rupture propagated toward east from the epicentral region passing through the sediment-filled Kathmandu Valley. This event resulted in over 8000 fatalities, mostly in Kathmandu and the adjacent districts. We succeeded in observing strong ground motions at our four observation sites (one rock site and three sedimentary sites) in the Kathmandu Valley during this devastating earthquake. While the observed peak ground acceleration values were smaller than the predicted ones that were derived from the use of a ground motion prediction equation, the observed peak ground velocity values were slightly larger than the predicted ones. The ground velocities observed at the rock site (KTP) showed a simple velocity pulse, resulting in monotonic-step displacements associated with the permanent tectonic offset. The vertical ground velocities observed at the sedimentary sites had the same pulse motions that were observed at the rock site. In contrast, the horizontal ground velocities as well as accelerations observed at three sedimentary sites showed long duration with conspicuous long-period oscillations, due to the valley response. The horizontal valley response was characterized by large amplification (about 10) and prolonged oscillations. However, the predominant period and envelope shape of their oscillations differed from site to site, indicating a complicated basin structure. Finally, on the basis of the velocity response spectra, we show that the horizontal long-period oscillations on the sedimentary sites had enough destructive power to damage high-rise buildings with natural periods of 3 to 5 s.

Seismic design of nuclear power plants - an assessment

International Nuclear Information System (INIS)

Howard, G.E.; Ibanez, P.; Smith, C.B.

1976-01-01

This paper presents a review and evaluation of the design standards and the analytical and experimental methods used in the seismic design of nuclear power plants with emphasis on United States practice. Three major areas were investigated: (a) soils, siting, and seismic ground motion specification; (b) soil-structure interaction; and (c) the response of major nuclear power plant structures and components. The purpose of this review and evaluation program was to prepare an independent assessment of the state-of-the-art of the seismic design of nuclear power plants and to identify seismic analysis and design research areas meriting support by the various organizations comprising the 'nuclear power industry'. Criteria used for evaluating the relative importance of alternative research areas included the potential research impact on nuclear power plant siting, design, construction, cost, safety, licensing, and regulation. (Auth.)

Early Site Permit Demonstration Program: Guidelines for determining design basis ground motions

International Nuclear Information System (INIS)

1993-01-01

This report develops and applies a methodology for estimating strong earthquake ground motion. The motivation was to develop a much needed tool for use in developing the seismic requirements for structural designs. An earthquake's ground motion is a function of the earthquake's magnitude, and the physical properties of the earth through which the seismic waves travel from the earthquake fault to the site of interest. The emphasis of this study is on ground motion estimation in Eastern North America (east of the Rocky Mountains), with particular emphasis on the Eastern United States and southeastern Canada. Eastern North America is a stable continental region, having sparse earthquake activity with rare occurrences of large earthquakes. While large earthquakes are of interest for assessing seismic hazard, little data exists from the region to empirically quantify their effects. Therefore, empirically based approaches that are used for other regions, such as Western North America, are not appropriate for Eastern North America. Moreover, recent advances in science and technology have now made it possible to combine theoretical and empirical methods to develop new procedures and models for estimating ground motion. The focus of the report is on the attributes of ground motion in Eastern North America that are of interest for the design of facilities such as nuclear power plants. Specifically considered are magnitudes M from 5 to 8, distances from 0 to 500 km, and frequencies from 1 to 35 Hz. This document, Volume IV, provides Appendix 8.B, Laboratory Investigations of Dynamic Properties of Reference Sites

Brayton Isotope Power System (BIPS) facility specification

International Nuclear Information System (INIS)

1976-01-01

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

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.

Experimental effective shape control of a powered transfemoral prosthesis.

Science.gov (United States)

Gregg, Robert D; Lenzi, Tommaso; Fey, Nicholas P; Hargrove, Levi J; Sensinger, Jonathon W

2013-06-01

This paper presents the design and experimental implementation of a novel feedback control strategy that regulates effective shape on a powered transfemoral prosthesis. The human effective shape is the effective geometry to which the biological leg conforms--through movement of ground reaction forces and leg joints--during the stance period of gait. Able-bodied humans regulate effective shapes to be invariant across conditions such as heel height, walking speed, and body weight, so this measure has proven to be a very useful tool for the alignment and design of passive prostheses. However, leg joints must be actively controlled to assume different effective shapes that are unique to tasks such as standing, walking, and stair climbing. Using our previous simulation studies as a starting point, we model and control the effective shape as a virtual kinematic constraint on the powered Vanderbilt prosthetic leg with a custom instrumented foot. An able-bodied subject used a by-pass adapter to walk on the controlled leg over ground and over a treadmill. These preliminary experiments demonstrate, for the first time, that effective shape (or virtual constraints in general) can be used to control a powered prosthetic leg.

SLG(Single-Line-to-Ground Fault Location in NUGS(Neutral Un-effectively Grounded System

Directory of Open Access Journals (Sweden)

Zhang Wenhai

2018-01-01

Full Text Available This paper reviews the SLG(Single-Line-to-Ground fault location methods in NUGS(Neutral Un-effectively Grounded System, including ungrounded system, resonant grounded system and high-resistance grounded system which are widely used in Northern Europe and China. This type of fault is hard to detect and location because fault current is the sum of capacitance current of the system which is always small(about tens of amperes. The characteristics of SLG fault in NUGS and the fault location methods are introduced in the paper.

Yet Another Puzzle of Ground

NARCIS (Netherlands)

Korbmacher, J.

2015-01-01

We show that any predicational theory of partial ground that extends a standard theory of syntax and that proves some commonly accepted principles for partial ground is inconsistent. We suggest a way to obtain a consistent predicational theory of ground.

A Mixed Prediction Model of Ground Subsidence for Civil Infrastructures on Soft Ground

Directory of Open Access Journals (Sweden)

Kiyoshi Kobayashi

2012-01-01

Full Text Available The estimation of ground subsidence processes is an important subject for the asset management of civil infrastructures on soft ground, such as airport facilities. In the planning and design stage, there exist many uncertainties in geotechnical conditions, and it is impossible to estimate the ground subsidence process by deterministic methods. In this paper, the sets of sample paths designating ground subsidence processes are generated by use of a one-dimensional consolidation model incorporating inhomogeneous ground subsidence. Given the sample paths, the mixed subsidence model is presented to describe the probabilistic structure behind the sample paths. The mixed model can be updated by the Bayesian methods based upon the newly obtained monitoring data. Concretely speaking, in order to estimate the updating models, Markov Chain Monte Calro method, which is the frontier technique in Bayesian statistics, is applied. Through a case study, this paper discussed the applicability of the proposed method and illustrated its possible application and future works.

Method of disposing of shut-down nuclear power plants

International Nuclear Information System (INIS)

Gaiser, H.

1984-01-01

A shut-down atomic power plant or a section thereof, particularly the nuclear reactor, is disposed of by sinking it to below ground level by constructing a caisson with cutting edges from the foundations of said plant or section or by excavating a pit therebelow

Self powered platinum flux detector application for shutdown system

International Nuclear Information System (INIS)

Su Guoquan

2005-01-01

This article introduce Neutron Flux Detector application in Candu Power Plant, including: design purpose, location in the site, dynamic compensation, differential compensation, detector assembly pressurized with high pure helium etc. And shielding grounding improvement is suggested because of detector signal and setpoint signal noise. (authors)

Ground penetrating radar system and method for detecting an object on or below a ground surface

NARCIS (Netherlands)

De Jongth, R.; Yarovoy, A.; Schukin, A.

2001-01-01

Ground penetrating radar system for detecting objects (17) on or below a ground surface (18), comprising at least one transmit antenna (13) having a first foot print (14) at the ground surface, at least one receive antenna (15) having a second foot print (16) at the ground surface, and processing

Effluent Containment System for space thermal nuclear propulsion ground test facilities

International Nuclear Information System (INIS)

1995-08-01

This report presents the research and development study work performed for the Space Reactor Power System Division of the U.S. Department of Energy on an innovative ECS that would be used during ground testing of a space nuclear thermal rocket engine. A significant portion of the ground test facilities for a space nuclear thermal propulsion engine are the effluent treatment and containment systems. The proposed ECS configuration developed recycles all engine coolant media and does not impact the environment by venting radioactive material. All coolant media, hydrogen and water, are collected, treated for removal of radioactive particulates, and recycled for use in subsequent tests until the end of the facility life. Radioactive materials removed by the treatment systems are recovered, stored for decay of short-lived isotopes, or packaged for disposal as waste. At the end of the useful life, the facility will be decontaminated and dismantled for disposal

Seismic hazard analysis. Review panel, ground motion panel, and feedback results

International Nuclear Information System (INIS)

Bernreuter, D.L.

1981-10-01

The Site Specific Spectra Project (SSSP) was a multi-year study funded by the U.S. Nuclear Regulatory Commission to provide estimates of the seismic hazards at a number of nuclear power plant sites in the Eastern U.S. A key element of our approach was the Peer Review Panel, which we formed in order to ensure that our use of expert opinion was reasonable. We discuss the Peer Review Panel results and provide the complete text of each member's report. In order to improve the ground motion model, an Eastern U.S. Ground Motion Model Panel was formed. In Section 4 we tabulate the responses from the panel members to our feedback questionnaire and discuss the implications of changes introduced by them. We conclude that the net difference in seismic hazard values from those presented in Volume 4 is small and does not warrant a reanalysis. (author)

Consistent interactive segmentation of pulmonary ground glass nodules identified in CT studies

Science.gov (United States)

Zhang, Li; Fang, Ming; Naidich, David P.; Novak, Carol L.

2004-05-01

Ground glass nodules (GGNs) have proved especially problematic in lung cancer diagnosis, as despite frequently being malignant they characteristically have extremely slow rates of growth. This problem is further magnified by the small size of many of these lesions now being routinely detected following the introduction of multislice CT scanners capable of acquiring contiguous high resolution 1 to 1.25 mm sections throughout the thorax in a single breathhold period. Although segmentation of solid nodules can be used clinically to determine volume doubling times quantitatively, reliable methods for segmentation of pure ground glass nodules have yet to be introduced. Our purpose is to evaluate a newly developed computer-based segmentation method for rapid and reproducible measurements of pure ground glass nodules. 23 pure or mixed ground glass nodules were identified in a total of 8 patients by a radiologist and subsequently segmented by our computer-based method using Markov random field and shape analysis. The computer-based segmentation was initialized by a click point. Methodological consistency was assessed using the overlap ratio between 3 segmentations initialized by 3 different click points for each nodule. The 95% confidence interval on the mean of the overlap ratios proved to be [0.984, 0.998]. The computer-based method failed on two nodules that were difficult to segment even manually either due to especially low contrast or markedly irregular margins. While achieving consistent manual segmentation of ground glass nodules has proven problematic most often due to indistinct boundaries and interobserver variability, our proposed method introduces a powerful new tool for obtaining reproducible quantitative measurements of these lesions. It is our intention to further document the value of this approach with a still larger set of ground glass nodules.

Electrical Ground System Design of PEFP

International Nuclear Information System (INIS)

Mun, Kyeong Jun; Jeon, Gye Po; Park, Sung Sik; Min, Yi Sub; Nam, Jung Min; Cho, Jang Hyung; Kim, Jun Yeon

2010-01-01

Since host site host site was selected Gyeong-ju city in January, 2006. we need design revision of Proton Accelerator research center to reflect on host site characteristics and several conditions. In this paper, electrical grounding and lightning protection design scheme is introduced. In electrical grounding system design of PEFP, we classified electrical facilities into 4 groups; equipment grounding (type A), instrument grounding (Type A), high frequency instrument grounding (Type C) and lightning arrestor grounding (Type D). Lightning protection system is designed in all buildings of proton accelerator research center of PEFP, including switchyard

Electrical Ground System Design of PEFP

Energy Technology Data Exchange (ETDEWEB)

Mun, Kyeong Jun; Jeon, Gye Po; Park, Sung Sik; Min, Yi Sub; Nam, Jung Min; Cho, Jang Hyung; Kim, Jun Yeon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2010-10-15

Since host site host site was selected Gyeong-ju city in January, 2006. we need design revision of Proton Accelerator research center to reflect on host site characteristics and several conditions. In this paper, electrical grounding and lightning protection design scheme is introduced. In electrical grounding system design of PEFP, we classified electrical facilities into 4 groups; equipment grounding (type A), instrument grounding (Type A), high frequency instrument grounding (Type C) and lightning arrestor grounding (Type D). Lightning protection system is designed in all buildings of proton accelerator research center of PEFP, including switchyard

Aerial radiation monitoring around the Fukushima Dai-ichi Nuclear Power Plant using an unmanned helicopter.

Science.gov (United States)

Sanada, Yukihisa; Torii, Tatsuo

2015-01-01

The Great East Japan Earthquake on March 11, 2011 generated a series of large tsunami that seriously damaged the Fukushima Dai-ichi Nuclear Power Plant (FDNPP), which resulted in the release of radioactive materials into the environment. To provide further details regarding the distribution of air dose rate and the distribution of radioactive cesium ((134)Cs and (137)Cs) deposition on the ground within a radius of approximately 5 km from the nuclear power plant, we carried out measurements using an unmanned helicopter equipped with a radiation detection system. The distribution of the air dose rate at a height of 1 m above the ground and the radioactive cesium deposition on the ground was calculated. Accordingly, the footprint of radioactive plumes that extended from the FDNPP was illustrated. Copyright © 2014 Elsevier Ltd. All rights reserved.

Kant on causal laws and powers.

Science.gov (United States)

Henschen, Tobias

2014-12-01

The aim of the paper is threefold. Its first aim is to defend Eric Watkins's claim that for Kant, a cause is not an event but a causal power: a power that is borne by a substance, and that, when active, brings about its effect, i.e. a change of the states of another substance, by generating a continuous flow of intermediate states of that substance. The second aim of the paper is to argue against Watkins that the Kantian concept of causal power is not the pre-critical concept of real ground but the category of causality, and that Kant holds with Hume that causal laws cannot be inferred non-inductively (that he accordingly has no intention to show in the Second analogy or elsewhere that events fall under causal laws). The third aim of the paper is to compare the Kantian position on causality with central tenets of contemporary powers ontology: it argues that unlike the variants endorsed by contemporary powers theorists, the Kantian variants of these tenets are resistant to objections that neo-Humeans raise to these tenets.

General conditions for electric power supply

International Nuclear Information System (INIS)

Anon.

1981-01-01

If it is uncertain whether future power bills will be paid fully, it is admissible to take an action claiming a declaration which states that the electricity rate payment boycotter has no right to non-payment nor a right to withhold payment towards the electricity supply utility, and that the electricity supply utility has the right to stop energy supply because of reduced electricity rate payments effected and/or announced, and to denounce the contract without observing any term of notice. If the electricity buyer reduces a power bill to be paid without any legal grounds, the electricity supply utility has the right to stop power supplies and to denounce the power supply contract without observing any term of notice. The freedom of thought and the freedom of opinion must not be expressed by reducing power bills to be paid. Basic rights discontinue to be effective as soon as a contract or law is broken. A weighing of protected interests is not effected if the exercise of a basic law is unlawful. (orig./HP) [de

Seismic reevaluation of existing nuclear power plants

International Nuclear Information System (INIS)

Hennart, J.C.

1978-01-01

The codes and regulations governing Nuclear Power Plant seismic analysis are continuously becoming more stringent. In addition, design ground accelerations of existing plants must sometimes be increased as a result of discovery of faulting zones or recording of recent earthquakes near the plant location after plant design. These new factors can result in augmented seismic design criteria. Seismic reanalysius of the existing Nuclear Power Plant structures and equipments is necessary to prevent the consequences of newly postulated accidents that could cause undue risk to the health or safety of the public. This paper reviews the developments of seismic analysis as applied to Nuclear Power Plants and the methods used by Westinghouse to requalify existing plants to the most recent safety requirements. (author)

Ground water and earthquakes

Energy Technology Data Exchange (ETDEWEB)

Ts' ai, T H

1977-11-01

Chinese folk wisdom has long seen a relationship between ground water and earthquakes. Before an earthquake there is often an unusual change in the ground water level and volume of flow. Changes in the amount of particulate matter in ground water as well as changes in color, bubbling, gas emission, and noises and geysers are also often observed before earthquakes. Analysis of these features can help predict earthquakes. Other factors unrelated to earthquakes can cause some of these changes, too. As a first step it is necessary to find sites which are sensitive to changes in ground stress to be used as sensor points for predicting earthquakes. The necessary features are described. Recording of seismic waves of earthquake aftershocks is also an important part of earthquake predictions.

Overview of the relations earthquake source parameters and the specification of strong ground motion for design purposes

International Nuclear Information System (INIS)

Bernreuter, D.L.

1977-08-01

One of the most important steps in the seismic design process is the specification of the appropriate ground motion to be input into the design analysis. From the point-of-view of engineering design analysis, the important parameters are peak ground acceleration, spectral shape and peak spectral levels. In a few cases, ground displacement is a useful parameter. The earthquake is usually specified by giving its magnitude and either the epicentral distance or the distance of the closest point on the causitive fault to the site. Typically, the appropriate ground motion parameters are obtained using the specified magnitude and distance in equations obtained from regression analysis among the appropriate variables. Two major difficulties with such an approach are: magnitude is not the best parameter to use to define the strength of an earthquake, and little near-field data is available to establish the appropriate form for the attenuation of the ground motion with distance, source size and strength. These difficulties are important for designing a critical facility; i.e., one for which a very low risk of exceeding the design ground motion is required. Examples of such structures are nuclear power plants, schools and hospitals. for such facilities, a better understanding of the relation between the ground motion and the important earthquake source parameters could be very useful for several reasons

Usos e Aplicações da Grounded Theory em Administração

Directory of Open Access Journals (Sweden)

Eliane Maria Pires Giavina Bianchi

2008-01-01

Full Text Available This paper discusses the usage and application of grounded theory in the administration area.Grounded theory is a research tool under the qualitative paradigm that, since its beginning in 1967raised some debates in the academic arena. Its original authors, Barney Glaser & Anselm Strauss,developed, throughout their academic trajectories,distinct thoughts regarding the process of datacollection and data analysis, the researcher attitude and the way of attainment the researchresults: theory grounded on empirical data. In spite of that, the history on the evolution of theresearch method, the research method working process clarification and an analysis of someapplications in the administrative area are discussed in this paper to support reflections ongrounded theory applicability and potentiality in administration. The purpose of this paper is tocontribute with researchers by bringing relevant information to support the processes of choice ofthis research method and its proper execution in their research. The conclusion is that groundedtheory is complex, rich, and powerful being applicable in administration as part of the social science

On LHCb muon MWPC grounding

CERN Document Server

Kashchuk, A

2006-01-01

My goal is to study how a big MWPC system, in particular the LHCb muon system, can be protected against unstable operation and multiple spurious hits, produced by incorrect or imperfect grounding in the severe EM environment of the LHCb experiment. A mechanism of penetration of parasitic current from the ground loop to the input of the front-end amplifier is discussed. A new model of the detector cell as the electrical bridge is considered. As shown, unbalance of the bridge makes detector to be sensitive to the noise in ground loop. Resonances in ground loop are specified. Tests of multiple-point and single-point grounding conceptions made on mock-up are presented.

Exogenous spatial attention influences figure-ground assignment.

Science.gov (United States)

Vecera, Shaun P; Flevaris, Anastasia V; Filapek, Joseph C

2004-01-01

In a hierarchical stage account of vision, figure-ground assignment is thought to be completed before the operation of focal spatial attention. Results of previous studies have supported this account by showing that unpredictive, exogenous spatial precues do not influence figure-ground assignment, although voluntary attention can influence figure-ground assignment. However, in these studies, attention was not summoned directly to a region in a figure-ground display. In three experiments, we addressed the relationship between figure-ground assignment and visuospatial attention. In Experiment 1, we replicated the finding that exogenous precues do not influence figure-ground assignment when they direct attention outside of a figure-ground stimulus. In Experiment 2, we demonstrated that exogenous attention can influence figure-ground assignment if it is directed to one of the regions in a figure-ground stimulus. In Experiment 3, we demonstrated that exogenous attention can influence figure-ground assignment in displays that contain a Gestalt figure-ground cue; this result suggests that figure-ground processes are not entirely completed prior to the operation of focal spatial attention. Exogenous spatial attention acts as a cue for figure-ground assignment and can affect the outcome of figure-ground processes.

Observations of Earth space by self-powered stations in Antarctica.