Automation of belts; Automatizacion de Cintas de Interior

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-07-01

This document presents the most important aspects, and the results of the project DEVELOPMENT AND COMMISSIONING OF AN INTEGRATED HAULAGE AND VENTILATION CONTROL SYSTEM IN A MINE USING VERY LONG SUBLEVEL-CAVING WINNING METHOD. Project's targets were to develop, implement and commission a distributed control system for underground mining, which should allow the control and optimisation of the whole (continuous) haulage network. It should also integrate statutory safety features required for both winning and haulage. The system is capable of controlling the most common devices used in underground coal mining transport networks, like conveyor belts, armored conveyors, regulation silos, etc. from the winning faces to the surface, and also the interlocks between them. Moreover, the system implements statutory safety functions for conveyor belt operation, and for mining activities carried out in culls de sac. Specifically, for its relationship with the transport system, it should monitor secondary ventilation, fire damp and toxic gases concentration, and mains power presence in the culls de sac, which have already reached a length of 2000 m. The prototype was installed in the mine that Carbones de Pedraforca owns in Saldes, Barcelona. (Author)

Human Mars Surface Mission Nuclear Power Considerations

Science.gov (United States)

Rucker, Michelle A.

2018-01-01

A key decision facing Mars mission designers is how to power a crewed surface field station. Unlike the solar-powered Mars Exploration Rovers (MER) that could retreat to a very low power state during a Martian dust storm, human Mars surface missions are estimated to need at least 15 kilowatts of electrical (kWe) power simply to maintain critical life support and spacecraft functions. 'Hotel' loads alone for a pressurized crew rover approach two kWe; driving requires another five kWe-well beyond what the Curiosity rover’s Radioisotope Power System (RPS) was designed to deliver. Full operation of a four-crew Mars field station is estimated at about 40 kWe. Clearly, a crewed Mars field station will require a substantial and reliable power source, beyond the scale of robotic mission experience. This paper explores the applications for both fission and RPS nuclear options for Mars.

Reference reactor module for NASA's lunar surface fission power system

International Nuclear Information System (INIS)

Poston, David I.; Kapernick, Richard J.; Dixon, David D.; Werner, James; Qualls, Louis; Radel, Ross

2009-01-01

Surface fission power systems on the Moon and Mars may provide the first US application of fission reactor technology in space since 1965. The Affordable Fission Surface Power System (AFSPS) study was completed by NASA/DOE to determine the cost of a modest performance, low-technical risk surface power system. The AFSPS concept is now being further developed within the Fission Surface Power (FSP) Project, which is a near-term technology program to demonstrate system-level TRL-6 by 2013. This paper describes the reference FSP reactor module concept, which is designed to provide a net power of 40 kWe for 8 years on the lunar surface; note, the system has been designed with technologies that are fully compatible with a Martian surface application. The reactor concept uses stainless-steel based. UO 2 -fueled, pumped-NaK fission reactor coupled to free-piston Stirling converters. The reactor shielding approach utilizes both in-situ and launched shielding to keep the dose to astronauts much lower than the natural background radiation on the lunar surface. The ultimate goal of this work is to provide a 'workhorse' power system that NASA can utilize in near-term and future Lunar and Martian mission architectures, with the eventual capability to evolve to very high power, low mass systems, for either surface, deep space, and/or orbital missions.

Pulsed discharges produced by high-power surface waves

Science.gov (United States)

Böhle, A.; Ivanov, O.; Kolisko, A.; Kortshagen, U.; Schlüter, H.; Vikharev, A.

1996-02-01

The mechanisms of the ionization front advance in surface-wave-produced discharges are investigated using two experimental set-ups. The high-power surface waves are excited in a 3 cm wavelength band by a surfaguide and a novel type of launcher (an E-plane junction). The ionization front velocity of the surface wave is measured for a wide range of gas pressures, incident microwave power and initial pre-ionization. The experimental results are compared with theoretical ones based on three different models. The comparison between theory and experiment allows one to suggest a new interpretation of the ionization front's advance. The ionization front velocity is determined by a breakdown wave or an ionization wave in the electric field of a high-power surface wave in the zone near the ionization front.

Experiences with fuels B30 and B 100 in haulage, railway operation and agricultural machinery

Energy Technology Data Exchange (ETDEWEB)

Matejovsky, V. [QMS Consulting, Prague (Czech Republic); Hendrych, K.; Mares, V. [PREOL, Lovosice (Czech Republic)

2013-06-01

High prices of diesel fuel have increased an interest in cheaper biodiesel, especially for vehicles with high fuel consumption and not only for haulage vehicle parks but also for railway vehicles and heavy agricultural machinery. When price difference between standard diesel B7 and cheaper biodiesel B100 reached more than 10% it was a sufficient benefit for operators to use biodiesel but this fuel had not been approved for all vehicles types by their manufacturers. Despite this problem, some operators have begun to use biodiesel also for vehicles not having the approval. To prevent operational problems and misgiving of engines damage, the transition to alternative fuel was organized as field tests of one or more vehicles from the operator's fleet. The tests usually started with B30 fuel and if no operational problems occurred the second stage continued with B100. The tested vehicles were under permanent surveillance at least during one year of operation and once a month and later once in a quarter a deeper inspections were made including engine diagnostics, emissions testing, engine oil sampling for laboratory examination, injectors tenting and filters and fuel hoses condition evaluation. The presentation includes the results of vehicles inspections and the measures that had to be done to prevent engines failure and to ensure trouble-free operation of vehicles using biofuels. (orig.)

Photovoltaic array for Martian surface power

Science.gov (United States)

Appelbaum, J.; Landis, G. A.

1992-01-01

Missions to Mars will require electric power. A leading candidate for providing power is solar power produced by photovoltaic arrays. To design such a power system, detailed information on solar-radiation availability on the Martian surface is necessary. The variation of the solar radiation on the Martian surface is governed by three factors: (1) variation in Mars-Sun distance; (2) variation in solar zenith angle due to Martian season and time of day; and (3) dust in the Martian atmosphere. A major concern is the dust storms, which occur on both local and global scales. However, there is still appreciable diffuse sunlight available even at high opacity, so that solar array operation is still possible. Typical results for tracking solar collectors are also shown and compared to the fixed collectors. During the Northern Hemisphere spring and summer the isolation is relatively high, 2-5 kW-hr/sq m-day, due to the low optical depth of the Martian atmosphere. These seasons, totalling a full terrestrial year, are the likely ones during which manned mission will be carried out.

Selected problems of coal mining mechanization in the coal industry of Poland

Energy Technology Data Exchange (ETDEWEB)

Antoniak, J; Sikora, W [Politechnika Slaska, Gliwice (Poland)

1987-01-01

Discusses conditions for underground coal mining in Poland, types of equipment for coal cutting, mine haulage and strata control and development trends of mining technologies. In 1985, black coal output was 191.6 Mt; 85.3% came from longwall faces mined by sets of mining equipment (coal cutters, chain conveyors and powered supports). The average coal output per longwall face was 881 t/d, output per face mined by sets for mining equipment was 1,134 t/d. In 1985, 653 shearer loaders and 77 coal plows were used in Polish coal mines. Number of shearer loaders is increasing. Shearer loaders with chainless haulage system were safest and most economic. The shearer loaders were equipped with the POLTRAK chainless haulage system developed in Poland. Research programs concentrate on development of new mining equipment for thin seam mining, steep seam mining, longwall mining with hydraulic stowing, efficient strata control by powered or shield supports under conditions of increased stresses or rock burst hazards. 4 refs.

The powerful pulsed electron beam effect on the metallic surfaces

International Nuclear Information System (INIS)

Neklyudov, I.M.; Yuferov, V.B.; Kosik, N.A.; Druj, O.S.; Skibenko, E.I.

2001-01-01

Experimental results of the influence of powerful pulsed electron beams on the surface structure,hardness and corrosion resistance of the Cr18ni10ti steel are presented. The experiments were carried out in the powerful electron accelerators of directional effect VGIK-1 and DIN-2K with an energy up to approx 300 KeV and a power density of 10 9 - 10 11 W/cm 2 for micro- and nanosecond range. The essential influence of the irradiation power density on the material structure was established. Pulsed powerful beam action on metallic surface leads to surface melting,modification of the structure and structure-dependent material properties. The gas emission and mass-spectrometer analysis of the beam-surface interaction were defined

Economics, organization, and planning in surface mining. Part I. Ekonomika, organizacja, i planowanie w gornictwie odkrywkowym. Czesc I

Energy Technology Data Exchange (ETDEWEB)

Trembecki, A; Uberman, R

1975-01-01

Describes the organization of the Ministry of Mining and Energy of the Polish People's Republic and the Union of the Brown Coal Industry. Principles of organization and management of brown coal mines are also outlined. Analyzed are: management structure of production at brown coal mines, management structure of coal preparation and of brown coal mining planning. Methods of production analysis are also explained including analysis of working time and methods based on photography. Organization of work and management of brown coal surface mines is described: organization of belt conveyor haulage, rail transport, truck transport, organization scheme for relocating belt conveyors and rails in surface mines. (31 refs.) (In Polish)

Potassium Rankine cycle power conversion systems for lunar-Mars surface power

International Nuclear Information System (INIS)

Holcomb, R.S.

1992-01-01

The potassium Rankine cycle has good potential for application to nuclear power systems for surface power on the moon and Mars. A substantial effort on the development of the power conversion system was carried out in the 1960's which demonstrated successful operation of components made of stainless steel at moderate temperatures. This technology could be applied in the near term to produce a 360 kW(e) power system by coupling a stainless steel power conversion system to the SP-100 reactor. Improved performance could be realized in later systems by utilizing niobium or tantalum refractory metal alloys in the reactor and power conversion system. The design characteristics and estimated mass of power systems for each of three technology levels are presented in the paper

Small reactor power systems for manned planetary surface bases

Energy Technology Data Exchange (ETDEWEB)

Bloomfield, H.S.

1987-12-01

A preliminary feasibility study of the potential application of small nuclear reactor space power systems to manned planetary surface base missions was conducted. The purpose of the study was to identify and assess the technology, performance, and safety issues associated with integration of reactor power systems with an evolutionary manned planetary surface exploration scenario. The requirements and characteristics of a variety of human-rated modular reactor power system configurations selected for a range of power levels from 25 kWe to hundreds of kilowatts is described. Trade-off analyses for reactor power systems utilizing both man-made and indigenous shielding materials are provided to examine performance, installation and operational safety feasibility issues. The results of this study have confirmed the preliminary feasibility of a wide variety of small reactor power plant configurations for growth oriented manned planetary surface exploration missions. The capability for power level growth with increasing manned presence, while maintaining safe radiation levels, was favorably assessed for nominal 25 to 100 kWe modular configurations. No feasibility limitations or technical barriers were identified and the use of both distance and indigenous planetary soil material for human rated radiation shielding were shown to be viable and attractive options.

Small reactor power systems for manned planetary surface bases

International Nuclear Information System (INIS)

Bloomfield, H.S.

1987-12-01

A preliminary feasibility study of the potential application of small nuclear reactor space power systems to manned planetary surface base missions was conducted. The purpose of the study was to identify and assess the technology, performance, and safety issues associated with integration of reactor power systems with an evolutionary manned planetary surface exploration scenario. The requirements and characteristics of a variety of human-rated modular reactor power system configurations selected for a range of power levels from 25 kWe to hundreds of kilowatts is described. Trade-off analyses for reactor power systems utilizing both man-made and indigenous shielding materials are provided to examine performance, installation and operational safety feasibility issues. The results of this study have confirmed the preliminary feasibility of a wide variety of small reactor power plant configurations for growth oriented manned planetary surface exploration missions. The capability for power level growth with increasing manned presence, while maintaining safe radiation levels, was favorably assessed for nominal 25 to 100 kWe modular configurations. No feasibility limitations or technical barriers were identified and the use of both distance and indigenous planetary soil material for human rated radiation shielding were shown to be viable and attractive options

An introduction to the integrated design of surface mine haul roads

Energy Technology Data Exchange (ETDEWEB)

Thompson, R.J.; Visser, A.T. [University of Pretoria, Pretoria (South Africa). Dept. of Mining Engineering

1997-12-01

The world-wide expansion of surface mining has led to the development of very large off-highway trucks currently capable of hauling layloads in excess of 160 t. Typical axle loads ranging from 110 t to 170 t are applied to haul roads that have been, at best, empirically designed on the premise of `satisfactory` or `failed`, both in terms of structure and function of the road. The use of these empirical pavement design techniques will prove inadequate when high axle loads are encountered. Not only will the maintenance costs of existing haul roads of inadequate thickness increase, but vehicle operating and maintenance costs will also increase prohibitively. Under these conditions there is thus a clearly defined need for improved construction and management techniques for flexible mine haulage roads, appropriate for the wheel loads of vehicles now in use. The aim of this paper is to introduce developments in haul road structural, functional and maintenance design and management which overcome the limitations associated with the previously empirical design techniques and to show how these developments are combined into an integrated design strategy combining construction techniques, available material and road maintenance equipment with hauler choice to realise a reduction in haulage and road maintenance costs. Future contributions will enumerate on the fundamental haul road structural, functional and maintenance design and management research from which these developments originated. 7 refs., 5 figs., 2 tabs.

Reference reactor module for NASA's lunar surface fission power system

Energy Technology Data Exchange (ETDEWEB)

Poston, David I [Los Alamos National Laboratory; Kapernick, Richard J [Los Alamos National Laboratory; Dixon, David D [Los Alamos National Laboratory; Werner, James [INL; Qualls, Louis [ORNL; Radel, Ross [SNL

2009-01-01

Surface fission power systems on the Moon and Mars may provide the first US application of fission reactor technology in space since 1965. The Affordable Fission Surface Power System (AFSPS) study was completed by NASA/DOE to determine the cost of a modest performance, low-technical risk surface power system. The AFSPS concept is now being further developed within the Fission Surface Power (FSP) Project, which is a near-term technology program to demonstrate system-level TRL-6 by 2013. This paper describes the reference FSP reactor module concept, which is designed to provide a net power of 40 kWe for 8 years on the lunar surface; note, the system has been designed with technologies that are fully compatible with a Martian surface application. The reactor concept uses stainless-steel based. UO{sub 2}-fueled, pumped-NaK fission reactor coupled to free-piston Stirling converters. The reactor shielding approach utilizes both in-situ and launched shielding to keep the dose to astronauts much lower than the natural background radiation on the lunar surface. The ultimate goal of this work is to provide a 'workhorse' power system that NASA can utilize in near-term and future Lunar and Martian mission architectures, with the eventual capability to evolve to very high power, low mass systems, for either surface, deep space, and/or orbital missions.

Closed Brayton Cycle Power Conversion Unit for Fission Surface Power Phase I Final Report

Science.gov (United States)

Fuller, Robert L.

2010-01-01

A Closed Brayton cycle power conversion system has been developed to support the NASA fission surface power program. The goal is to provide electricity from a small nuclear reactor heat source for surface power production for lunar and Mars environments. The selected media for a heat source is NaK 78 with water as a cooling source. The closed Brayton cycle power was selected to be 12 kWe output from the generator terminals. A heat source NaK temperature of 850 K plus or minus 25 K was selected. The cold source water was selected at 375 K plus or minus 25 K. A vacuum radiation environment of 200 K is specified for environmental operation. The major components of the system are the power converter, the power controller, and the top level data acquisition and control unit. The power converter with associated sensors resides in the vacuum radiation environment. The power controller and data acquisition system reside in an ambient laboratory environment. Signals and power are supplied across the pressure boundary electrically with hermetic connectors installed on the vacuum vessel. System level analyses were performed on working fluids, cycle design parameters, heater and cooling temperatures, and heat exchanger options that best meet the needs of the power converter specification. The goal is to provide a cost effective system that has high thermal-to-electric efficiency in a compact, lightweight package.

Photonic surfaces for designable nonlinear power shaping

Energy Technology Data Exchange (ETDEWEB)

Biswas, Roshni, E-mail: rbiswas@usc.edu; Povinelli, Michelle L. [Ming Hsieh Department of Electrical Engineering, University of Southern California, Los Angeles, California 90089 (United States)

2015-02-09

We propose a method for designing nonlinear input-output power response based on absorptive resonances of nanostructured surfaces. We show that various power transmission trends can be obtained by placing a photonic resonance mode at the appropriate detuning from the laser wavelength. We demonstrate our results in a silicon photonic crystal slab at a laser wavelength of 808 nm. We quantify the overall spectral red shift as a function of laser power. The shift results from absorptive heating and the thermo-optic effect. We then demonstrate devices with increasing, decreasing, and non-monotonic transmission as a function of laser power. The transmission changes are up to 7.5 times larger than in unpatterned silicon. The strong nonlinear transmission is due to a combination of resonantly enhanced absorption, reduced thermal conductivity, and the resonant transmission lineshape. Our results illustrate the possibility of designing different nonlinear power trends within a single materials platform at a given wavelength of interest.

Photonic surfaces for designable nonlinear power shaping

International Nuclear Information System (INIS)

Biswas, Roshni; Povinelli, Michelle L.

2015-01-01

We propose a method for designing nonlinear input-output power response based on absorptive resonances of nanostructured surfaces. We show that various power transmission trends can be obtained by placing a photonic resonance mode at the appropriate detuning from the laser wavelength. We demonstrate our results in a silicon photonic crystal slab at a laser wavelength of 808 nm. We quantify the overall spectral red shift as a function of laser power. The shift results from absorptive heating and the thermo-optic effect. We then demonstrate devices with increasing, decreasing, and non-monotonic transmission as a function of laser power. The transmission changes are up to 7.5 times larger than in unpatterned silicon. The strong nonlinear transmission is due to a combination of resonantly enhanced absorption, reduced thermal conductivity, and the resonant transmission lineshape. Our results illustrate the possibility of designing different nonlinear power trends within a single materials platform at a given wavelength of interest

Pratt and Whitney ESCORT derivative for mars surface power

International Nuclear Information System (INIS)

Feller, Gerald J.; Joyner, Russell

1999-01-01

The purpose of this paper is to address the applicability of a common reactor system design from the Pratt and Whitney ESCORT nuclear thermal rocket engine concept to support current NASA mars surface-based power requirements. The ESCORT is a bimodal engine capable of supporting a wide range of propulsive thermal and vehicle electrical power requirements. The ESCORT engine is powered by a fast-spectrum beryllium-reflected CERMET-fueled nuclear reactor. In addition to an expander cycle propulsive mode, the ESCORT is capable of operating in an electrical power mode. In this mode, the reactor is used to heat a mixture of helium and xenon to drive a closed-loop Brayton cycle in order to generate electrical energy. Recent Design Reference Mission requirements (DRM) from NASA Johnson Space Center and NASA Lewis Research Center studies in 1997 and 1998 have detailed upgraded requirements for potential mars transfer missions. The current NASA DRM requires a nuclear thermal propulsion system capable of delivering total mission requirements of 200170 N (45000 lbf) thrust and 50 kWe of spacecraft electrical power. Additionally, these requirements detailed a surface power system capable of providing approximately 160 kW of electrical energy over an approximate 10 year period within a given weight and volume envelope. Current NASA studies use a SP-100 reactor (0.8 MT) and a NERVA derivative (1.6 MT) as baseline systems. A mobile power cart of approximate dimensions 1.7 mx4.5 mx4.4 m has been conceptualized to transport the reactor power system on the Mars Surface. The 63.25 cm diameter and 80.25 cm height of the ESCORT and its 1.3 MT of weight fit well within the current weight and volume target range of the NASA DRM requirements. The modifications required to the ESCORT reactor system to support this upgraded electrical power requirements along with operation in the Martian atmospheric conditions are addressed in this paper. Sufficient excess reactivity and burnup capability

Stable and flexible under power; Stabil und flexibel unter Strom

Energy Technology Data Exchange (ETDEWEB)

Irrgang, Reinhard

2011-03-25

If conveyor routes, shelve service devices, hall cranes or other haulage equipment - all this systems want to be supported economically, securely and reliably by energy. Optimized energy chains and gliding connect with innovative details function as probate systems. Also touchless energy- and data transmission technologies open an immense potential. (orig./GL)

Fission Surface Power System Initial Concept Definition

Science.gov (United States)

2010-01-01

Under the NASA Exploration Technology Development Program (ETDP) and in partnership with the Department of Energy (DOE), NASA has embarked on a project to develop Fission Surface Power (FSP) technology. The primary goals of the project are to 1) develop FSP concepts that meet expected surface power requirements at reasonable cost with added benefits over other options, 2) establish a hardwarebased technical foundation for FSP design concepts and reduce overall development risk, 3) reduce the cost uncertainties for FSP and establish greater credibility for flight system cost estimates, and 4) generate the key products to allow NASA decision-makers to consider FSP as a preferred option for flight development. The FSP project was initiated in 2006 as the Prometheus Program and the Jupiter Icy Moons Orbiter (JIMO) mission were phased-out. As a first step, NASA Headquarters commissioned the Affordable Fission Surface Power System Study to evaluate the potential for an affordable FSP development approach. With a cost-effective FSP strategy identified, the FSP team evaluated design options and selected a Preliminary Reference Concept to guide technology development. Since then, the FSP Preliminary Reference Concept has served as a point-of-departure for several NASA mission architecture studies examining the use of nuclear power and has provided the foundation for a series of "Pathfinder" hardware tests. The long-term technology goal is a Technology Demonstration Unit (TDU) integrated system test using full-scale components and a non-nuclear reactor simulator. The FSP team consists of Glenn Research Center (GRC), Marshall Space Flight Center (MSFC) and the DOE National Laboratories at Los Alamos (LANL), Idaho (INL), Oak Ridge (ORNL), and Sandia (SNL). The project is organized into two main elements: Concept Definition and Risk Reduction. Under Concept Definition, the team performs trade studies, develops analytical tools, and formulates system concepts. Under Risk

Power Spectral Density Evaluation of Laser Milled Surfaces

Directory of Open Access Journals (Sweden)

Raoul-Amadeus Lorbeer

2017-12-01

Full Text Available Ablating surfaces with a pulsed laser system in milling processes often leads to surface changes depending on the milling depth. Especially if a constant surface roughness and evenness is essential to the process, structural degradation may advance until the process fails. The process investigated is the generation of precise thrust by laser ablation. Here, it is essential to predict or rather control the evolution of the surfaces roughness. Laser ablative milling with a short pulse laser system in vacuum (≈1 Pa were performed over depths of several 10 µm documenting the evolution of surface roughness and unevenness with a white light interference microscope. Power spectral density analysis of the generated surface data reveals a strong influence of the crystalline structure of the solid. Furthermore, it was possible to demonstrate that this effect could be suppressed for gold.

A radioisotope-powered surface acoustic wave transponder

International Nuclear Information System (INIS)

Tin, S; Lal, A

2009-01-01

We demonstrate a 63 Ni radioisotope-powered pulse transponder that has a SAW (surface acoustic wave) device as the frequency transmission frequency selector. Because the frequency is determined by a SAW device, narrowband detection with an identical SAW device enables the possibility for a long-distance RF-link. The SAW transponders can be buried deep into structural constructs such as steel and concrete, where changing batteries or harvesting vibration or EM energy is not a reliable option. RF-released power to radioisotope- released power amplification is 10 8 , even when regulatory safe amounts of 63 Ni are used. Here we have achieved an 800 µW pulse (315 MHz, 10 µs pause) across a 50 Ω load every 3 min, using a 1.5 milli-Ci 63 Ni source

A dynamic isotope power system for Space Exploration Initiative surface transport systems

International Nuclear Information System (INIS)

Hunt, M.E.; Harty, R.B.; Cataldo, R.

1992-03-01

The Dynamic Isotope Power System (DIPS) Demonstration Program, sponsored by the U.S. Department of Energy with support funding from NASA, is currently focused on the development of a standardized 2.5-kWe portable generator for multiple applications on the lunar or Martian surface. A variety of remote and mobile potential applications have been identified by NASA, including surface rovers for both short- and extended-duration missions, remote power to science packages, and backup to central base power. Recent work focused on refining the 2.5-kWe design and emphasizing the compatibility of the system with potential surface transport systems. Work included an evaluation of the design to ensure compatibility with the Martian atmosphere while imposing only a minor mass penalty on lunar operations. Additional work included a study performed to compare the DIPS with regenerative fuel cell systems for lunar mobile and remote power systems. Power requirements were reviewed and a modular system chosen for the comparison. 4 refs

A Two-Phase Cooling Loop for Fission Surface Power Waste Heat Transport, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Current lunar-based Fission Surface Power (FSP) Systems that will support sustained surface outposts consist of a nuclear reactor with power converters, whose waste...

Optimization of shovel-truck system for surface mining

Energy Technology Data Exchange (ETDEWEB)

Ercelebi, S.G.; Bascetin, A. [Istanbul Technical University, Istanbul (Turkey). Mining Engineering Department

2009-07-15

In surface mining operations, truck haulage is the largest item in the operating costs, constituting 50 to 60% of the total. In order to reduce this cost, it is necessary to allocate and dispatch the trucks efficiently. This paper describes shovel and truck operation models and optimization approaches for the allocation and dispatching of trucks under various operating conditions. Closed queuing network theory is employed for the allocation of trucks and linear programming for the purpose of truck dispatching to shovels. A case study was applied for the Orhaneli open Pit Coal Mine in Turkey. This approach would provide the capability of estimating system performance measures (mine throughput, mean number of trucks, mean waiting time, etc.) for planning purposes when the truck fleet is composed of identical trucks. A computational study is presented to show how choosing the optimum number of trucks and optimum dispatching policy affect the cost of moving material in a truck-shovel system.

Lunar surface fission power supplies: Radiation issues

International Nuclear Information System (INIS)

Houts, M.G.; Lee, S.K.

1994-01-01

A lunar space fission power supply shield that uses a combination of lunar regolith and materials brought from earth may be optimal for early lunar outposts and bases. This type of shield can be designed such that the fission power supply does not have to be moved from its landing configuration, minimizing handling and required equipment on the lunar surface. Mechanisms for removing heat from the lunar regolith are built into the shield, and can be tested on earth. Regolith activation is greatly reduced compared with a shield that uses only regolith, and it is possible to keep the thermal conditions of the fission power supply close to these seen in free space. For a well designed shield, the additional mass required to be brought fro earth should be less than 1000 kg. Detailed radiation transport calculations confirm the feasibility of such a shield

Lunar surface fission power supplies: Radiation issues

International Nuclear Information System (INIS)

Houts, M.G.; Lee, S.K.

1994-01-01

A lunar space fission power supply shield that uses a combination of lunar regolith and materials brought from earth may be optimal for early lunar outposts and bases. This type of shield can be designed such that the fission power supply does not have to be moved from its landing configuration, minimizing handling and required equipment on the lunar surface. Mechanisms for removing heat from the lunar regolith are built into the shield, and can be tested on earth. Regolith activation is greatly reduced compared with a shield that uses only regolith, and it is possible to keep the thermal conditions of the fission power supply close to those seen in free space. For a well designed shield, the additional mass required to be brought from earth should be less than 1,000 kg. Detailed radiation transport calculations confirm the feasibility of such a shield

Surface temperature and distortion of optical elements exposed to high power synchrotron radiation beams

International Nuclear Information System (INIS)

Mourikis, S.; Jark, W.; Koch, E.E.; Saile, V.

1989-01-01

Mirrors made of various materials have been investigated under surface power densities of approximately 1--2 W/mm 2 emitted by a powerful hybrid wiggler installed in the 5.3-GeV DORIS storage ring. Thermal inhomogeneities and deformations at surfaces with a height resolution of 50 nm have been determined quantitatively. The only material withstanding these power levels without a significant deformation is SiC. Conventional cooling geometries are found to be useless for a reduction of the surface distortion

Method of cutting steeply falling coal beds. [Bacteria, which only grow on methane, are injected into the coal bed and form low viscosity polysaccharides: as a result the coal collapses into the haulage gallery and is hauled away

Energy Technology Data Exchange (ETDEWEB)

Gretsinger, B Ye; Chernyshenko, D V; Levin, A D; Malashenko, Yu R; Shinkovskiy, V A; Shurova, Z P; Volkov, V I

1982-01-01

The purpose of the invention is to reduce outlays for collapse and output of coal by creating artificial cavities of sliding along the coal bed in the surrounding rocks. This goal is achieved because in the well drilled in the bed for the entire height of the level, a suspension of cells of methane-oxidizing microorganisms is injected. The methane-oxidizing microorganisms used are, for example, the thermophilic culture Methylococcus thermophilus of strains ShP which grow at 45-65/sup 0/ C, or the mesophilic culture Methanomonas rubna of strains 15 Sh growing at 20-37/sup 0/ C. As a result of the vital activity of these cultures, polysaccharides are formed with viscosity of 5-7 and 3-4 St respectively. The mine pressure disrupts the blocks between the wells, and the outline section of the steeply dropping coal bed, being destroyed, slides on the products of vital activity of the microorganisms to the haulage gallery. Then the coal drops on cross cuts to the field gallery through which it is transported. Studies established that the only coal substrate which is suitable for growth of these microorganism cultures is methane. The synthesis of one g of absolutely dry substance of these microorganism requires 1.78 g of methane and 4.7 g of oxygen. The cultures are resistant to hydrostatic pressure from 20 to 150 atm and short-term pressure of gradient drops which occur during injection of the cellular suspension into the coal bed. They are filtered through the coal with preservation of the oxidizing and reproductive properties and are cultivated on the methane contained in the bed and form considerable number of exopolysaccarides. The polysaccarides weaken the bond between the bed and the surrounding rocks and serve as a unique lubricant promoting the sliding towards the haulage gallery of the coal blocks destroyed by mine pressure.

Increasing shaft depth with rock hoisting to the surface. [USSR

Energy Technology Data Exchange (ETDEWEB)

Durov, E.M.

1982-06-01

Schemes of shaft construction with increasing shaft depth depend on: shaft depth, shaft diameter, types of hoisting systems, schemes of shaft reinforcement. Investigations carried out in underground coal mines in the USSR show that waste rock haulage to the surface by an independent hoisting system is most economical. Installation of this system depends on the existing hoisting scheme. When one of the operating cages or skips can be removed without a negative influence on mine operation the system of rock waste hoisting is used. The hoisting bucket used for rock removal from the shaft bottom moves in the shaft section from which one of the cages or skips has been removed. Examples of using this scheme in Donbass, Kuzbass and other coal basins are given. Economic aspects of waste material hoisting to the surface are analyzed. The system is economical when the remaining hoisting system can accept additional loads after removal of a cage or skip from the shaft. Investigations show that use of a bucket with a capacity from 2.5 to 3.0 m/sup 3/ for waste rock removal from the shaft being modernized and deepened is most economical.

Developments in the application of underground battery vehicles in the UK coal mining industry

Energy Technology Data Exchange (ETDEWEB)

Fortune, J A.B.; Crawshaw, S A.M. [Long-Airdox International Ltd. (United Kingdom)

1996-10-01

Trackless battery powered haulage vehicles have been in operation in British coal mines principally for longwall face transfer and personnel transportation. Changes within the industry have resulted in the introduction of room and pillar coal mining methods and the introduction of increasingly heavier longwall roof supports. This has resulted in the introduction of: battery powered coal haulage machines, which, without the need for trailing cables, increase productivity within room and pillar mining; and battery powered longwall shield haulers which are capable of carrying the heaviest shield supports currently being utilised within the British coal mining industry. The conventional machines have been adapted from an American design to meet the requirements of European legislation. This has seen the emphasis being placed upon the supplier with the European Machinery Directive being introduced, necessitating the assigning of a `CE` mark to each vehicle. Battery vehicle technology has advanced to meet the demands of the ever changing market and will no doubt be further adapted to meet the requirement of the British coal mining industry. 1 ref., 12 figs., 3 tabs.

Effects of rf power on chemical composition and surface roughness of glow discharge polymer films

Energy Technology Data Exchange (ETDEWEB)

Zhang, Ling; He, Xiaoshan; Chen, Guo; Wang, Tao; Tang, Yongjian; He, Zhibing, E-mail: hezhibing802@163.com

2016-03-15

Graphical abstract: - Highlights: • The growth mechanism of defects in GDP films was studied upon plasma diagnosis. • Increasing rf power enhanced the etching effects of smaller-mass species. • The “void” defect was caused by high energy hydrocarbons bombardment on the surface. • The surface roughness was only 12.76 nm, and no “void” defect was observed at 30 W. - Abstract: The glow discharge polymer (GDP) films for laser fusion targets were successfully fabricated by plasma enhanced chemical vapor deposition (PECVD) at different radio frequency (rf) powers. The films were deposited using trans-2-butene (T{sub 2}B) mixed with hydrogen as gas sources. The composition and state of plasma were diagnosed by quadrupole mass spectrometer (QMS) and Langmuir probe during the deposition process. The composition, surface morphology and roughness were investigated by Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and white-light interferometer (WLI), respectively. Based on these observation and analyses, the growth mechanism of defects in GDP films were studied. The results show that, at low rf power, there is a larger probability for secondary polymerization and formation of multi-carbon C-H species in the plasma. In this case, the surface of GDP film turns to be cauliflower-like. With the increase of rf power, the degree of ionization is high, the relative concentration of smaller-mass hydrocarbon species increases, while the relative concentration of larger-mass hydrocarbon species decreases. At higher rf power, the energy of smaller-mass species are high and the etching effects are strong correspondingly. The GDP film's surface roughness shows a trend of decrease firstly and then increase with the increasing rf power. At rf power of 30 W, the surface root-mean-square roughness (Rq) drops to the lowest value of 12.8 nm, and no “void” defect was observed.

Radioisotope Stirling Engine Powered Airship for Atmospheric and Surface Exploration of Titan

Science.gov (United States)

Colozza, Anthony J.; Cataldo, Robert L.

2014-01-01

The feasibility of an advanced Stirling radioisotope generator (ASRG) powered airship for the near surface exploration of Titan was evaluated. The analysis did not consider the complete mission only the operation of the airship within the atmosphere of Titan. The baseline airship utilized two ASRG systems with a total of four general-purpose heat source (GPHS) blocks. Hydrogen gas was used to provide lift. The ASRG systems, airship electronics and controls and the science payload were contained in a payload enclosure. This enclosure was separated into two sections, one for the ASRG systems and the other for the electronics and payload. Each section operated at atmospheric pressure but at different temperatures. The propulsion system consisted of an electric motor driving a propeller. An analysis was set up to size the airship that could operate near the surface of Titan based on the available power from the ASRGs. The atmospheric conditions on Titan were modeled and used in the analysis. The analysis was an iterative process between sizing the airship to carry a specified payload and the power required to operate the electronics, payload and cooling system as well as provide power to the propulsion system to overcome the drag on the airship. A baseline configuration was determined that could meet the power requirements and operate near the Titan surface. From this baseline design additional trades were made to see how other factors affected the design such as the flight altitude and payload mass and volume.

Enhancing Plasma Surface Modification using high Intensity and high Power Ultrasonic Acoustic Waves

DEFF Research Database (Denmark)

2010-01-01

high intensity and high power acoustic waves (102) by at least one ultrasonic high intensity and high power acoustic wave generator (101 ), wherein the ultrasonic acoustic waves are directed to propagate towards said surface (314) of the object (100) so that a laminar boundary layer (313) of a gas...... or a mixture of gases (500) flow in contact with said solid object (100) is thinned or destructed for at least a part of said surface (314). In this way, the plasma can more efficiently access and influence the surface of the solid object to be treated by the plasma, which speeds the process time up...

Interplanetary and lunar surface SP-100 nuclear power applications

International Nuclear Information System (INIS)

Josloff, A.T.; Shepard, N.F.; Smith, M.; Stephen, J.D.

1992-01-01

This paper describes how the SP-100 Space Reactor Power System (SRPS) can be tailored to meet the specific requirements for a lunar surface power system to meet the needs of the consolidation and utilization phases outlined in the 90-day NASA SEI study report. This same basic power system can also be configured to obtain the low specific masses needed to enable robotic interplanetary science missions employing Nuclear Electric Propulsion (NEP). In both cases it is shown that the SP-100 SRPS can meet the specific requirements. For interplanetary NEP missions, performance upgrades currently being developed in the area of light weight radiators and improved thermoelectric material are assumed to be technology ready in the year 2000 time frame. For lunar applications, some system rearrangement and enclosure of critical components are necessary modifications to the present baseline design

Use of the PZK system for pneumatic stowing along mine workings

Energy Technology Data Exchange (ETDEWEB)

Makarevich, Yu S; Buzhin, N K; Churakov, V N

1983-07-01

The utilization of waste rock for pneumatic stowing in the Komsomolets Donbassa mine with coal seams to 1 m thick and dip angles from 3 to 11/sup 0/ is evaluated. Gate roads used for mine haulage by belt conveyors are controlled by cribbings made of timber and of concrete blocks, particularly at junction of working facese by belt conveyors are controlled by cribbings made of timber and of concrete blocks, particularly at junction of working faces with gate goads. Effects of pneumatic stowing on strata control cost and environmental protection are analyzed. Waste rock which has been dumped at spoil banks on the ground surface is crushed by the PZK system developed by Dongiproshakht. The PZK system is installed underground close to haulage roadways. Crushed rock material with size from 0 to 80 mm and compression strength coefficient from 3 to 5 degrees on the Protod'yakonov scale is hauled by mine cars to working faces and stowed by the DZM-2 pneumatic system. Strips of pneumatic stowing at each side of a gate road are from 12 to 15 m wide. Design of the PZM system and of a rock hopper used for accumulation of crushed rock as well as design of the DZM-2 system are shown in schemes. Economic analysis shows that use of pneumatic stowing reduces roof subsidence in the haulage gate road to 20% and eliminates cribbings. Use of pneumatic stowing for strata control in haulage gate roads economizes 65 rubles per 1 m of gate road.

Surface treatments for material protection in nuclear power plants

International Nuclear Information System (INIS)

De, P.K.; Gadiyar, H.S.

1987-01-01

The paper highlights some of the surface treatment methods used in nuclear power plants to improve their performance. The corrosion resistance of zirconium alloys results from the formation of an adherent and protective film of ZrO 2 . Graphite coating of zircaloy-2 cladding minimizes the susceptibility to environmental induced cracking. Magnetite formation during the hot conditioning operation improves the corrosion resistance of carbon steel as well as controls the spread of radioactivity. It has been illustrated how the surface treatment is helpful for redistributing residual stress to facilitate conversion of tensile stress to compressive stress to mitigate failures due to stress corrosion and fatigue corrosion. Inhibitors and passivators can modify the surface conditions (in situ) of condenser tubes and cooling water systems. These aspects have been dealt in the text of the paper. (author). 8 refs., 3 figures

Radiation characteristics of input power from surface wave sustained plasma antenna

Energy Technology Data Exchange (ETDEWEB)

Naito, T., E-mail: Naito.Teruki@bc.MitsubishiElectric.co.jp [Advanced Technology R& D Center, Mitsubishi Electric Corporation, Amagasaki, Hyogo 661-8661 (Japan); Yamaura, S. [Information Technology R& D Center, Mitsubishi Electric Corporation, Kamakura, Kanagawa 247-8501 (Japan); Fukuma, Y. [Communication System Center, Mitsubishi Electric Corporation, Amagasaki, Hyogo 661-8661 (Japan); Sakai, O. [Department of Electronic System Engineering, The University of Shiga Prefecture, Hikone, Shiga 522-8533 (Japan)

2016-09-15

This paper reports radiation characteristics of input power from a surface wave sustained plasma antenna investigated theoretically and experimentally, especially focusing on the power consumption balance between the plasma generation and the radiation. The plasma antenna is a dielectric tube filled with argon and small amount of mercury, and the structure is a basic quarter wavelength monopole antenna at 2.45 GHz. Microwave power at 2.45 GHz is supplied to the plasma antenna. The input power is partially consumed to sustain the plasma, and the remaining part is radiated as a signal. The relationship between the antenna gain and the input power is obtained by an analytical derivation and numerical simulations. As a result, the antenna gain is kept at low values, and most of the input power is consumed to increase the plasma volume until the tube is filled with the plasma whose electron density is higher than the critical electron density required for sustaining the surface wave. On the other hand, the input power is consumed to increase the electron density after the tube is fully filled with the plasma, and the antenna gain increases with increasing the electron density. The dependence of the antenna gain on the electron density is the same as that of a plasma antenna sustained by a DC glow discharge. These results are confirmed by experimental results of the antenna gain and radiation patterns. The antenna gain of the plasma is a few dB smaller than that of the identical metal antenna. The antenna gain of the plasma antenna is sufficient for the wireless communication, although it is difficult to substitute the plasma antenna for metal antennas completely. The plasma antenna is suitable for applications having high affinity with the plasma characteristics such as low interference and dynamic controllability.

Radiation characteristics of input power from surface wave sustained plasma antenna

International Nuclear Information System (INIS)

Naito, T.; Yamaura, S.; Fukuma, Y.; Sakai, O.

2016-01-01

This paper reports radiation characteristics of input power from a surface wave sustained plasma antenna investigated theoretically and experimentally, especially focusing on the power consumption balance between the plasma generation and the radiation. The plasma antenna is a dielectric tube filled with argon and small amount of mercury, and the structure is a basic quarter wavelength monopole antenna at 2.45 GHz. Microwave power at 2.45 GHz is supplied to the plasma antenna. The input power is partially consumed to sustain the plasma, and the remaining part is radiated as a signal. The relationship between the antenna gain and the input power is obtained by an analytical derivation and numerical simulations. As a result, the antenna gain is kept at low values, and most of the input power is consumed to increase the plasma volume until the tube is filled with the plasma whose electron density is higher than the critical electron density required for sustaining the surface wave. On the other hand, the input power is consumed to increase the electron density after the tube is fully filled with the plasma, and the antenna gain increases with increasing the electron density. The dependence of the antenna gain on the electron density is the same as that of a plasma antenna sustained by a DC glow discharge. These results are confirmed by experimental results of the antenna gain and radiation patterns. The antenna gain of the plasma is a few dB smaller than that of the identical metal antenna. The antenna gain of the plasma antenna is sufficient for the wireless communication, although it is difficult to substitute the plasma antenna for metal antennas completely. The plasma antenna is suitable for applications having high affinity with the plasma characteristics such as low interference and dynamic controllability.

Temperature evaluation of dental implant surface irradiated with high-power diode laser.

Science.gov (United States)

Rios, F G; Viana, E R; Ribeiro, G M; González, J C; Abelenda, A; Peruzzo, D C

2016-09-01

The prevalence of peri-implantitis and the absence of a standard approach for decontamination of the dental implant surface have led to searches for effective therapies. Since the source of diode lasers is portable, has reduced cost, and does not cause damage to the titanium surface of the implant, high-power diode lasers have been used for this purpose. The effect of laser irradiation on the implants is the elevation of the temperature surface. If this elevation exceeds 47 °C, the bone tissue is irreversibly damaged, so for a safety therapy, the laser parameters should be controlled. In this study, a diode laser of GaAsAl was used to irradiate titanium dental implants, for powers 1.32 to 2.64 W (real) or 2.00 to 4.00 W (nominal), in continuous/pulsed mode DC/AC, with exposure time of 5/10 s, with/without air flow for cooling. The elevation of the temperature was monitored in real time in two positions: cervical and apical. The best results for decontamination using a 968-nm diode laser were obtained for a power of 1.65 and 1.98 W (real) for 10 s, in DC or AC mode, with an air flow of 2.5 l/min. In our perspective in this article, we determine a suggested approach for decontamination of the dental implant surface using a 968-nm diode laser.

Highly-productive mechanization systems for coal mining in the Polish coal industry

Energy Technology Data Exchange (ETDEWEB)

Sikora, W

1985-01-01

Effects of mechanization on underground coal mining in Poland from 1960 to 1980 and mining equipment used in Poland is reviewed. In 1983 black coal output increased to 191.1 Mt. There were 765 working faces, 442 of which with powered supports. Six hundred thirty-four shearer loaders were in use. About 82.7% of coal output fell on faces mined by sets of mining equipment (shearer loaders, powered supports and chain conveyors). The average coal output per working face amounted to 889 t/d. About 50% of mine roadways was driven by heading machines (346 heading machines were in use). The average coal output per face mined by a set of mining equipment amounted to 1248 t/d. About 86% of shearer loaders fell on double drum shearer loaders. Types of mining equipment used in underground mining are reviewed: powered supports (Pioma, Fazos, Glinik and the SOW), shearer loaders (drum shearer loaders and double-drum shearer loaders with chain haulage and chainless haulage systems for unidirectional and bi-directional mining), chain conveyors (Samson, Rybnik). Statistical data on working faces with various sets of equipment are given. 3 references.

Power Spectral Density Specification and Analysis of Large Optical Surfaces

Science.gov (United States)

Sidick, Erkin

2009-01-01

The 2-dimensional Power Spectral Density (PSD) can be used to characterize the mid- and the high-spatial frequency components of the surface height errors of an optical surface. We found it necessary to have a complete, easy-to-use approach for specifying and evaluating the PSD characteristics of large optical surfaces, an approach that allows one to specify the surface quality of a large optical surface based on simulated results using a PSD function and to evaluate the measured surface profile data of the same optic in comparison with those predicted by the simulations during the specification-derivation process. This paper provides a complete mathematical description of PSD error, and proposes a new approach in which a 2-dimentional (2D) PSD is converted into a 1-dimentional (1D) one by azimuthally averaging the 2D-PSD. The 1D-PSD calculated this way has the same unit and the same profile as the original PSD function, thus allows one to compare the two with each other directly.

Powerful highly efficient KrF lamps excited by surface and barrier discharges

International Nuclear Information System (INIS)

Borisov, V M; Vodchits, V A; El'tsov, A V; Khristoforov, O B

1998-01-01

An investigation was made of the characteristics of KrF lamps with different types of excitation by surface and barrier discharges in which the dielectric material was sapphire. The conditions were determined for the attainment of an extremely high yield of the KrF* fluorescence with the internal efficiency η in ∼30 % and 22% for pulsed surface and barrier discharges, respectively. A homogeneous surface discharge was maintained without gas circulation when the pulse repetition rate was 5 x 10 4 Hz. Quasicontinuous excitation of a surface discharge at near-atmospheric pressure made it possible to reach a KrF* fluorescence power density of about 80 W cm -3 , which was close to the limit set by the kinetics of the gaseous medium. Under prolonged excitation conditions the intensity of the UV output radiation was limited by the permissible heating of the gas to a temperature above which the operating life of the gaseous mixture containing fluorine fell steeply. This was the reason for the advantage of surface over barrier discharges: the former were characterised by a high thermal conductivity of a thin (∼0.2 mm) plasma layer on the surface of the cooled dielectric, which made it possible to construct powerful highly efficient KrF and ArF lamps emitting UV radiation of up to 1 W cm -2 intensity. (laser system components)

Fission Surface Power Technology Demonstration Unit Test Results

Science.gov (United States)

Briggs, Maxwell H.; Gibson, Marc A.; Geng, Steven M.; Sanzi, James L.

2016-01-01

The Fission Surface Power (FSP) Technology Demonstration Unit (TDU) is a system-level demonstration of fission power technology intended for use on manned missions to Mars. The Baseline FSP systems consists of a 190 kWt UO2 fast-spectrum reactor cooled by a primary pumped liquid metal loop. This liquid metal loop transfers heat to two intermediate liquid metal loops designed to isolate fission products in the primary loop from the balance of plant. The intermediate liquid metal loops transfer heat to four Stirling Power Conversion Units (PCU), each of which produce 12 kWe (48 kW total) and reject waste heat to two pumped water loops, which transfer the waste heat to titanium-water heat pipe radiators. The FSP TDU simulates a single leg of the baseline FSP system using an electrically heater core simulator, a single liquid metal loop, a single PCU, and a pumped water loop which rejects the waste heat to a Facility Cooling System (FCS). When operated at the nominal operating conditions (modified for low liquid metal flow) during TDU testing the PCU produced 8.9 kW of power at an efficiency of 21.7 percent resulting in a net system power of 8.1 kW and a system level efficiency of 17.2 percent. The reduction in PCU power from levels seen during electrically heated testing is the result of insufficient heat transfer from the NaK heater head to the Stirling acceptor, which could not be tested at Sunpower prior to delivery to the NASA Glenn Research Center (GRC). The maximum PCU power of 10.4 kW was achieved at the maximum liquid metal temperature of 875 K, minimum water temperature of 350 K, 1.1 kg/s liquid metal flow, 0.39 kg/s water flow, and 15.0 mm amplitude at an efficiency of 23.3 percent. This resulted in a system net power of 9.7 kW and a system efficiency of 18.7 percent.

K-correlation power spectral density and surface scatter model

Science.gov (United States)

Dittman, Michael G.

2006-08-01

The K-Correlation or ABC model for surface power spectral density (PSD) and BRDF has been around for years. Eugene Church and John Stover, in particular, have published descriptions of its use in describing smooth surfaces. The model has, however, remained underused in the optical analysis community partially due to the lack of a clear summary tailored toward that application. This paper provides the K-Correlation PSD normalized to σ(λ) and BRDF normalized to TIS(σ,λ) in a format intended to be used by stray light analysts. It is hoped that this paper will promote use of the model by analysts and its incorporation as a standard tool into stray light modeling software.

Surface morphology and surface energy of anode materials influence power outputs in a multi-channel mediatorless bio-photovoltaic (BPV) system.

Science.gov (United States)

Bombelli, Paolo; Zarrouati, Marie; Thorne, Rebecca J; Schneider, Kenneth; Rowden, Stephen J L; Ali, Akin; Yunus, Kamran; Cameron, Petra J; Fisher, Adrian C; Ian Wilson, D; Howe, Christopher J; McCormick, Alistair J

2012-09-21

Bio-photovoltaic cells (BPVs) are a new photo-bio-electrochemical technology for harnessing solar energy using the photosynthetic activity of autotrophic organisms. Currently power outputs from BPVs are generally low and suffer from low efficiencies. However, a better understanding of the electrochemical interactions between the microbes and conductive materials will be likely to lead to increased power yields. In the current study, the fresh-water, filamentous cyanobacterium Pseudanabaena limnetica (also known as Oscillatoria limnetica) was investigated for exoelectrogenic activity. Biofilms of P. limnetica showed a significant photo response during light-dark cycling in BPVs under mediatorless conditions. A multi-channel BPV device was developed to compare quantitatively the performance of photosynthetic biofilms of this species using a variety of different anodic conductive materials: indium tin oxide-coated polyethylene terephthalate (ITO), stainless steel (SS), glass coated with a conductive polymer (PANI), and carbon paper (CP). Although biofilm growth rates were generally comparable on all materials tested, the amplitude of the photo response and achievable maximum power outputs were significantly different. ITO and SS demonstrated the largest photo responses, whereas CP showed the lowest power outputs under both light and dark conditions. Furthermore, differences in the ratios of light : dark power outputs indicated that the electrochemical interactions between photosynthetic microbes and the anode may differ under light and dark conditions depending on the anodic material used. Comparisons between BPV performances and material characteristics revealed that surface roughness and surface energy, particularly the ratio of non-polar to polar interactions (the CQ ratio), may be more important than available surface area in determining biocompatibility and maximum power outputs in microbial electrochemical systems. Notably, CP was readily outperformed by all

Floor surface decontaminating device for use in nuclear power plants

International Nuclear Information System (INIS)

Yoshida, Tomiji; Ue, Tatsuyuki; Omori, Nobuya; Okuzawa, Tsutomu.

1987-01-01

Purpose: To obtain a device for decontaminating the floor surfaces contaminated with radioactive materials in nuclear power plants or the likes, mechanically, automatically and effectively. Constitution: During running of the device by means of running wheels and castors, a decontaminating head is always applied with vibrations by a vibrator. In this state, wiping members are sent from a delivery roll, applied with vibrations at the decontaminating head. The members wipe off contamination products while in frictional contact with the floor surface and are then taken up to a winding roll with the contamination products deposited thereto. In this case, since the vibrations from the decontaminating head are transmitted by way of a resilient portion thereof to the wiping members, the vibrations transmitted from the wiping members to the floor surface are somewhat buffered. (Kawakami, Y.)

High Efficiency, High Temperature Foam Core Heat Exchanger for Fission Surface Power Systems, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Fission-based power systems with power levels of 30 to ≥100 kWe will be needed for planetary surface bases. Development of high temperature, high efficiency heat...

Radar Men on the Moon: A Brief Survey of Fission Surface Power Studies

International Nuclear Information System (INIS)

Bennett, Gary L.

2008-01-01

This paper reviews some of the salient fission surface power studies, including those dating back to the early SNAP (Systems for Nuclear Auxiliary Power) program. Particular attention will be focused on the more recent Space Exploration Initiative (including the related Synthesis Group report) and Vision for Space Exploration. Commonalties in these studies will be noted; for example, many studies have shown that powers in the range of 100 kWe are required for human-tended bases on the Moon and Mars. Just as advanced human civilizations depend upon electrical power so will advanced, human-occupied lunar and Mars bases with powers rising into the megawatt level for bases with manufacturing and resource utilization capabilities. The role of radioisotope power sources will also be noted

Radar Men on the Moon: A Brief Survey of Fission Surface Power Studies

Science.gov (United States)

Bennett, Gary L.

2008-01-01

This paper reviews some of the salient fission surface power studies, including those dating back to the early SNAP (Systems for Nuclear Auxiliary Power) program. Particular attention will be focused on the more recent Space Exploration Initiative (including the related Synthesis Group report) and Vision for Space Exploration. Commonalties in these studies will be noted; for example, many studies have shown that powers in the range of 100 kWe are required for human-tended bases on the Moon and Mars. Just as advanced human civilizations depend upon electrical power so will advanced, human-occupied lunar and Mars bases with powers rising into the megawatt level for bases with manufacturing and resource utilization capabilities. The role of radioisotope power sources will also be noted.

A Practical Approach to Starting Fission Surface Power Development

International Nuclear Information System (INIS)

Mason, Lee

2006-01-01

The Prometheus Power and Propulsion Program has been reformulated to address NASA needs relative to lunar and Mars exploration. Emphasis has switched from the Jupiter Icy Moons Orbiter (JIMO) flight system development to more generalized technology development addressing Fission Surface Power (FSP) and Nuclear Thermal Propulsion (NTP). Current NASA budget priorities and the deferred mission need date for nuclear systems prohibit a fully funded reactor Flight Development Program. However, a modestly funded Advanced Technology Program can and should be conducted to reduce the risk and cost of future flight systems. A potential road-map for FSP technology development leading to possible flight applications could include three elements: 1) Conceptual Design Studies, 2) Advanced Component Technology, and 3) Non-Nuclear System Testing. The Conceptual Design Studies would expand on recent NASA and DOE analyses while increasing the depth of study in areas of greatest uncertainty such as reactor integration and human-rated shielding. The Advanced Component Technology element would address the major technology risks through development and testing of reactor fuels, structural materials, primary loop components, shielding, power conversion, heat rejection, and power management and distribution (PMAD). The Non-Nuclear System Testing would provide a modular, technology test-bed to investigate and resolve system integration issues. (author)

Evaluation of Surface Roughness and Power Consumption in Machining FCD 450 Cast Iron using Coated and Uncoated Irregular Milling Tools

International Nuclear Information System (INIS)

Yusoff, Ahmad Razlan; Arsyad, Fitriyanti

2016-01-01

In this project, the effects of different cutting parameters on surface roughness and power consumption when machining FCD450 cast iron were studied using coated and uncoated irregular milling tool geometry of variable helix and pitch. Their responses on roughness and power consumption were evaluated based on the spindle speed, feed rate, and depth of cut, machining length and machining time. Results showed that except spindle speed and machining length, other parameters such as feed rate, axial and radial depth of cut and also machining time proportionate with surface roughness. The power consumption proportionately increase for all cutting parameters except feedrate. It is showed that the average decrement 27.92 percent for surface roughness and average decrement 9.32 percent for power consumption by using coated compared to uncoated tool. Optimum cutting parameters for both minimum surface roughness and power consumption can be determined. The coated tools performed better than uncoated milling tools for responses of surface roughness and power consumption to increase machining productivity and profit. (paper)

Surface processing by high power excimer laser

Energy Technology Data Exchange (ETDEWEB)

Stehle, M [SOPRA, 92 - Bois-Colombes (France)

1995-03-01

Surface processing with lasers is a promising field of research and applications because lasers bring substantial advantages : laser beams work at distance, laser treatments are clean in respect of environment consideration and they offer innovative capabilities for surface treatment which cannot be reached by other way. Excimer lasers are pulsed, gaseous lasers which emit in UV spectral range - the most common are XeCl (308 nm), KrF (248 nm), ArF (193 nm). From 1980 up to 1994, many of them have been used for research, medical and industrial applications such as spectroscopy, PRK (photo-refractive keratotomy) and micro-machining. In the last six years, from 1987 up to 1993, efforts have been done in order to jump from 100 W average power up to 1 kW for XeCl laser at {lambda} = 308 nm. It was the aim of AMMTRA project in Japan as EU205 and EU213 Eureka projects in Europe. In this framework, SOPRA developed VEL (Very large Excimer Laser). In 1992, 1 kW (10 J x 100 Hz) millstone has been reached for the first time, this technology is based on X-Ray preionization and large laser medium (5 liters). Surface treatments based on this laser source are the main purpose of VEL Lasers. Some of them are given for instance : (a) Turbine blades made with metallic substrate and ceramic coatings on the top, are glazed in order to increase corrosion resistance of ceramic and metal sandwich. (b) Selective ablation of organic coatings deposited on fragile composite material is investigated in Aerospace industry. (c) Chock hardening of bulk metallic materials or alloys are investigated for automotive industry in order to increase wear resistance. (d) Ablation of thin surface oxides of polluted steels are under investigation in nuclear industry for decontamination. (J.P.N.).

Surface processing by high power excimer laser

International Nuclear Information System (INIS)

Stehle, M.

1995-01-01

Surface processing with lasers is a promising field of research and applications because lasers bring substantial advantages : laser beams work at distance, laser treatments are clean in respect of environment consideration and they offer innovative capabilities for surface treatment which cannot be reached by other way. Excimer lasers are pulsed, gaseous lasers which emit in UV spectral range - the most common are XeCl (308 nm), KrF (248 nm), ArF (193 nm). From 1980 up to 1994, many of them have been used for research, medical and industrial applications such as spectroscopy, PRK (photo-refractive keratotomy) and micro-machining. In the last six years, from 1987 up to 1993, efforts have been done in order to jump from 100 W average power up to 1 kW for XeCl laser at λ = 308 nm. It was the aim of AMMTRA project in Japan as EU205 and EU213 Eureka projects in Europe. In this framework, SOPRA developed VEL (Very large Excimer Laser). In 1992, 1 kW (10 J x 100 Hz) millstone has been reached for the first time, this technology is based on X-Ray preionization and large laser medium (5 liters). Surface treatments based on this laser source are the main purpose of VEL Lasers. Some of them are given for instance : a) Turbine blades made with metallic substrate and ceramic coatings on the top, are glazed in order to increase corrosion resistance of ceramic and metal sandwich. b) Selective ablation of organic coatings deposited on fragile composite material is investigated in Aerospace industry. c) Chock hardening of bulk metallic materials or alloys are investigated for automotive industry in order to increase wear resistance. d) Ablation of thin surface oxides of polluted steels are under investigation in nuclear industry for decontamination. (J.P.N.)

Planning maximum extraction of a safety pillar in the Most surface mine

Energy Technology Data Exchange (ETDEWEB)

Helis, P; Hess, L; Kubiznak, K [SHR - Banske Projekty, Teplice (Czechoslovakia)

1990-11-01

Discusses planned coal surface mining in the Most mine in the area of the Hnevin safety pillar with coal reserves amounting to about 7.5 Mt. The following aspects are evaluated: coal reserves and their distribution in the pillar, coal seam thickness and dip angles, water conditions, water influx rates, mechanical properties of the overburden and strata situated in the seam floor, slope stability and hazards of landslides, effects of water influx on landslide hazards, types of bucket wheel excavators used for overburden removal and mining, types of belt conveyors used for mine haulage, stackers, position of mining equipment in the mine. A scheme developed by Banske Projekty Teplice for partial extraction of the safety pillar would result in extraction of 4.5 Mt coal. About 1.7 Mt coal would be left in a safety coal layer about 10.0 m thick situated in the floor in zones with landslide hazards. KU 300 bucket wheel excavators, belt conveyors 1,200 mm wide and ZP 2,500 stackers would be used. 4 refs.

Er,Cr:YSGG Laser Energy Delivery: Pulse and Power Effects on Enamel Surface and Erosive Resistance.

Science.gov (United States)

de Oliveira, Renan Mota; de Souza, Vinicius Matsuzaki; Esteves, Camila Machado; de Oliveira Lima-Arsati, Ynara Bosco; Cassoni, Alessandra; Rodrigues, José Augusto; Brugnera Junior, Aldo

2017-11-01

High power lasers have been suggested as a useful tool for dental caries and erosion prevention due to the increase of enamel acid resistance. to evaluate the effect of Er,Cr:YSGG (erbium,chromium:yttrium, scandium, gallium, garnet) laser irradiation pulse frequency and power on enamel surface and acid erosion resistance. By combining pulse frequency (5-75 Hz) and power settings (0.10-1.00 W), 20 irradiated groups and one nonirradiated control group were tested. A total of 63 bovine enamel blocks (n = 3/group) were prepared for surface hardness and roughness evaluation, performed in three phases: baseline, after irradiation, and after erosive challenge. Enamel blocks were irradiated with Er,Cr:YSGG laser with MZ8 tip (iPlus; Waterlase, Biolase, CA) for 30 sec according to experimental group and submitted. Erosive challenge consisted of four cycles alternating immersion in 0.01 M HCl (5 mL/mm 2 ; 2 min; at 37°C) and immersion in artificial saliva for 3 h. Analysis of variance (three-way ANOVA), Tukey's test, and Pearson correlation were performed for the statistical analysis (p hardness. After erosive challenge, 5 and 75 W groups showed increase in surface hardness; 0.25, 0.5, 0.75, and 1 W groups showed minor alterations in surface roughness. the irradiation of Er,Cr:YSGG laser with different parameters of power and pulse frequency settings may alter enamel surface and erosive resistance differently. Pulse frequency of 30 Hz and power of 0.50 W was considered the best parameter to prevent enamel acid erosion.

Contribution of inner shell electrons to position-dependent stopping powers of a crystal surface

International Nuclear Information System (INIS)

Narumi, Kazumasa; Fujii, Yoshikazu; Kishine, Keiji; Kurakake, Hiroshi; Kimura, Kenji; Mannami, Michi-hiko

1994-01-01

Position-dependent stopping powers of the (001) surface of SnTe single crystal for specularly reflected 15 - 200 keV H + ions are studied. The position dependence of the experimental stopping powers varies with the energy of ions. From the comparison with the theoretical stopping powers based on both the single ion-electron collision and the collective excitation of the valence electrons, it is concluded that the observed change in the position-dependent stopping powers with energy of H + is due to the variation of contribution of inner shell electrons to stopping. (author)

Comparison of dynamic isotope power systems for distributed planet surface applications

Science.gov (United States)

Bents, David J.; Mckissock, Barbara I.; Hanlon, James C.; Schmitz, Paul C.; Rodriguez, Carlos D.; Withrow, Colleen A.

1991-01-01

Dynamic isotope power system (DIPS) alternatives were investigated and characterized for the surface mission elements associated with a lunar base and subsequent manned Mars expedition. System designs based on two convertor types were studied. These systems were characterized parametrically and compared over the steady-state electrical output power range 0.2 to 20 kWe. Three methods of thermally integrating the heat source and the Stirling heater head were considered, depending on unit size. Figures of merit were derived from the characterizations and compared over the parametric range. Design impacts of mission environmental factors are discussed and quantitatively assessed.

Nuclear or conventional power for surface combatant ships: Department of the Navy. Report to the Congress

International Nuclear Information System (INIS)

1977-01-01

GAO reviewed the controversy over whether the Navy's major surface combatant ships should be all nuclear powered, all conventionally powered, or a mix of both. Nuclear ships are more capable but cost more and their relative cost-effectiveness cannot be measured because Navy analysts cannot quantify many benefits of nuclear power. The Congress, in reviewing Navy shipbuilding plans for surface combatant ships, should be cognizant that buying only conventional ships will maximize naval firepower; buying only nuclear ships will provide mobility and greater freedom from logistics support; and buying a mix is a third option providing, to varying degrees, the advantages and disadvantages of the all-nuclear and all-conventional options

Power Prediction Model for Turning EN-31 Steel Using Response Surface Methodology

Directory of Open Access Journals (Sweden)

M. Hameedullah

2010-01-01

Full Text Available Power consumption in turning EN-31 steel (a material that is most extensively used in automotive industry with tungstencarbide tool under different cutting conditions was experimentally investigated. The experimental runs were planned accordingto 24+8 added centre point factorial design of experiments, replicated thrice. The data collected was statisticallyanalyzed using Analysis of Variance technique and first order and second order power consumption prediction models weredeveloped by using response surface methodology (RSM. It is concluded that second-order model is more accurate than thefirst-order model and fit well with the experimental data. The model can be used in the automotive industries for decidingthe cutting parameters for minimum power consumption and hence maximum productivity

A Basic LEGO Reactor Design for the Provision of Lunar Surface Power

International Nuclear Information System (INIS)

John Darrell Bess

2008-01-01

A final design has been established for a basic Lunar Evolutionary Growth-Optimized (LEGO) Reactor using current and near-term technologies. The LEGO Reactor is a modular, fast-fission, heatpipe-cooled, clustered-reactor system for lunar-surface power generation. The reactor is divided into subcritical units that can be safely launched with lunar shipments from Earth, and then emplaced directly into holes drilled into the lunar regolith to form a critical reactor assembly. The regolith would not just provide radiation shielding, but serve as neutron-reflector material as well. The reactor subunits are to be manufactured using proven and tested materials for use in radiation environments, such as uranium-dioxide fuel, stainless-steel cladding and structural support, and liquid-sodium heatpipes. The LEGO Reactor system promotes reliability, safety, and ease of manufacture and testing at the cost of an increase in launch mass per overall rated power level and a reduction in neutron economy when compared to a single-reactor system. A single unshielded LEGO Reactor subunit has an estimated mass of approximately 448 kg and provides approximately 5 kWe. The overall envelope for a single subunit with fully extended radiator panels has a height of 8.77 m and a diameter of 0.50 m. Six subunits could provide sufficient power generation throughout the initial stages of establishing a lunar outpost. Portions of the reactor may be neutronically decoupled to allow for reduced power production during unmanned periods of base operations. During later stages of lunar-base development, additional subunits may be emplaced and coupled into the existing LEGO Reactor network, subject to lunar base power demand. Improvements in reactor control methods, fuel form and matrix, shielding, as well as power conversion and heat rejection techniques can help generate an even more competitive LEGO Reactor design. Further modifications in the design could provide power generative opportunities for

Planning, layout and infrastructure of modern coal mines

Energy Technology Data Exchange (ETDEWEB)

Haarmann, K R

1978-02-01

When designing layout and infrastructure of new coal mines, the principles of planning play a decisive role. Apart from exploration, ventilation, transport, dirt haulage and product haulage, material transport is very important. Illustrated by three examples, modern layout and infrastructure design is presented.

Study of Dynamic Features of Surface Plasma in High-Power Disk Laser Welding

International Nuclear Information System (INIS)

Wang Teng; Gao Xiangdong; Seiji, Katayama; Jin, Xiaoli

2012-01-01

High-speed photography was used to obtain the dynamic changes in the surface plasma during a high-power disk laser welding process. A color space clustering algorithm to extract the edge information of the surface plasma region was developed in order to improve the accuracy of image processing. With a comparative analysis of the plasma features, i.e., area and height, and the characteristics of the welded seam, the relationship between the surface plasma and the stability of the laser welding process was characterized, which provides a basic understanding for the real-time monitoring of laser welding.

Mine drivage in hydraulic mines

Energy Technology Data Exchange (ETDEWEB)

Ehkber, B Ya

1983-09-01

From 20 to 25% of labor cost in hydraulic coal mines falls on mine drivage. Range of mine drivage is high due to the large number of shortwalls mined by hydraulic monitors. Reducing mining cost in hydraulic mines depends on lowering drivage cost by use of new drivage systems or by increasing efficiency of drivage systems used at present. The following drivage methods used in hydraulic mines are compared: heading machines with hydraulic haulage of cut rocks and coal, hydraulic monitors with hydraulic haulage, drilling and blasting with hydraulic haulage of blasted rocks. Mining and geologic conditions which influence selection of the optimum mine drivage system are analyzed. Standardized cross sections of mine roadways driven by the 3 methods are shown in schemes. Support systems used in mine roadways are compared: timber supports, roof bolts, roof bolts with steel elements, and roadways driven in rocks without a support system. Heading machines (K-56MG, GPKG, 4PU, PK-3M) and hydraulic monitors (GMDTs-3M, 12GD-2) used for mine drivage are described. Data on mine drivage in hydraulic coal mines in the Kuzbass are discussed. From 40 to 46% of roadways are driven by heading machines with hydraulic haulage and from 12 to 15% by hydraulic monitors with hydraulic haulage.

Construction and modernization of underground and surface mines. [USSR

Energy Technology Data Exchange (ETDEWEB)

Burshtein, N M

1983-12-01

Development of the Sredazugol' association in Soviet Central Asia from 1976 to 1985 is discussed. From 1976 to 1980 investment in the association amounted to 151 million rubles, 87.5 million of which fell on construction. Major development projects of the 1976-1980 period are reviewed: construction of new mining levels in underground coal mines, development of a number of operating surface mines, modernization of earthmoving and mining equipment, development of mine haulage by locomotives and railroad cars, improving occupational safety in coal mining, increasing slope stability in surface mining, especially in the area of the Atchinsk landslide in the Angren mine. From 1981 to 1985 investment in the Sredazugol' association should amount to 202 million rubles, of which 126 million rubles will be spent on construction. Investment will be 35% higher than in the 1976-1980 period and investment in mine construction 43% higher. The largest development project will be modernization of the Angren surface mine and increasing its targeted coal output from 5.2 Mt/y to 10.3 Mt/y by 1990. Modernization and reconstruction of the Angren mine will be carried out in 2 stages. Coal output of the mine will increase by 1.2 Mt/y in the current 5 year plan (by 1985), and by 3.9 Mt/y in the next 5 year period. Reconstruction and development of the Angren mine will cost approximately 254 million rubles. Mining and earthmoving equipment which will be used in the Angren mine is reviewed: EhRGV-630 bucket wheel excavators, EhSh-10/70 and EhSh-13/50 walking draglines, etc.

The use of surface power for characterisation of structure-borne sound sources of low modal density

DEFF Research Database (Denmark)

Ohlrich, Mogens

1996-01-01

The use of the surface power methods for source characterisaiton of vibrating machinery of low modal density is investigated in this paper. It was demonstrated by Ohlrich and Larsen that this relatively simple, but very useful measurement technique for quantifying the vibratory strength of machin......The use of the surface power methods for source characterisaiton of vibrating machinery of low modal density is investigated in this paper. It was demonstrated by Ohlrich and Larsen that this relatively simple, but very useful measurement technique for quantifying the vibratory strength...

Influence of power supply on the generation of ozone and degradation of phenol in a surface discharge reactor

International Nuclear Information System (INIS)

Zhao, Yan; Shang, Kefeng; Duan, Lijuan; Li, Yue; An, Jiutao; Zhang, Chunyang; Lu, Na; Wu, Yan; Li, Jie

2013-01-01

A surface Dielectric Barrier Discharge (DBD) reactor was utilized to degrade phenol in water. Different power supplies applied to the DBD reactor affect the discharge modes, the formation of chemically active species and thus the removal efficiency of pollutants. It is thus important to select an optimized power supply for the DBD reactor. In this paper, the influence of the types of power supplies including alternate current (AC) and bipolar pulsed power supply on the ozone generation in a surface discharge reactor was measured. It was found that compared with bipolar pulsed power supply, higher energy efficiency of O 3 generation was obtained when DBD reactor was supplied with 50Hz AC power supply. The highest O 3 generation was approximate 4 mg kJ −1 ; moreover, COD removal efficiency of phenol wastewater reached 52.3% after 3 h treatment under an AC peak voltage of 2.6 kV.

Influence of power supply on the generation of ozone and degradation of phenol in a surface discharge reactor

Science.gov (United States)

Zhao, Yan; Shang, Kefeng; Duan, Lijuan; Li, Yue; An, Jiutao; Zhang, Chunyang; Lu, Na; Li, Jie; Wu, Yan

2013-03-01

A surface Dielectric Barrier Discharge (DBD) reactor was utilized to degrade phenol in water. Different power supplies applied to the DBD reactor affect the discharge modes, the formation of chemically active species and thus the removal efficiency of pollutants. It is thus important to select an optimized power supply for the DBD reactor. In this paper, the influence of the types of power supplies including alternate current (AC) and bipolar pulsed power supply on the ozone generation in a surface discharge reactor was measured. It was found that compared with bipolar pulsed power supply, higher energy efficiency of O3 generation was obtained when DBD reactor was supplied with 50Hz AC power supply. The highest O3 generation was approximate 4 mg kJ-1 moreover, COD removal efficiency of phenol wastewater reached 52.3% after 3 h treatment under an AC peak voltage of 2.6 kV.

30 CFR 77.1608 - Dumping facilities.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Dumping facilities. 77.1608 Section 77.1608 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH... Haulage § 77.1608 Dumping facilities. (a) Dumping locations and haulage roads shall be kept reasonably...

30 CFR 75.1404 - Automatic brakes; speed reduction gear.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Automatic brakes; speed reduction gear. 75.1404... Automatic brakes; speed reduction gear. [Statutory Provisions] Each locomotive and haulage car used in an... permit automatic brakes, locomotives and haulage cars shall be subject to speed reduction gear, or other...

Experience of the leading miner crew in the 'Severo-Vostochnyi' im. 50-letiya Velikogo Oktyabrya surface mine. Opyt raboty peredovykh brigad razreza 'Severo-vostochnyi' im. 50-letiya Velikogo Oktyabrya

Energy Technology Data Exchange (ETDEWEB)

Banshchikov, G I; Demidova, A O

1981-01-01

The paper evaluates surface coal mining in the Dal'vostugol' association. Five surface mines of the association mined 13.8 Mt in 1980, 105,900 m/sup 3/ of overburden were removed, overburden to coal ratio was 7.67 m/sup 3//t, labor productivity per miner was 663 t/month, mining cost 2.70 ruble/t. Use of powerful walking draglines for mining, overburden removal and spoil bank formation influenced mining schemes and permitted labor productivity to be increased. Mining schemes without transport of overburden are shown . The following types of mining equipment were used: EhSh-15/90, EhSh-14/75, EhSh-10/60 and EhSh-10/70 draglines, EhKG-4.6u and EhVG-4I face shovels. Mining and geologic conditions are described: climatic conditions are characterized by intensive temperature fluctuation. Air temperature in January ranges from minus 26.8 C to minus 41.0 C and in July from 7.2 C to 31.9 C, the annual precipitation is 622 mm. Thickness of frozen soil in winter ranges from 2.5 to 3.0 m. Geologic conditions of the basin are analyzed: coal seam thickness, depth, coal properties, ash, sulfur, volatile matter, moisture, calorific value, stratification of overburden, mechanical properties of overburden, ground water and water influx. Operation of the Dal'vostugol' mines is described on the example of the Severo-Vostochnyi surface mine, the largest of the region (47% of the coal output). The following aspects of mine operation are evaluated: coal output, economic analysis, mining cost, mining equipment, earthmoving equipment (draglines), mine haulage, effects of climates (particularly equipment repairs), mining schemes, failures of excavators, innovation and safety.

Surface electric fields and geomagnetically induced currents in the Scottish Power grid during the 30 October 2003 geomagnetic storm

OpenAIRE

Thomson, Alan W.P.; McKay, Allan J.; Clarke, Ellen; Reay, Sarah J.

2005-01-01

A surface electric field model is used to estimate the UK surface E field during the 30 October 2003 severe geomagnetic storm. This model is coupled with a power grid model to determine the flow of geomagnetically induced currents (GIC) through the Scottish part of the UK grid. Model data are compared with GIC measurements at four sites in the power network. During this storm, measured and modeled GIC levels exceeded 40 A, and the surface electric field reached 5 V/km at sites in ...

ITO-MgF2 Film Development for PowerSphere Polymer Surface Protection

Science.gov (United States)

Hambourger, Paul D.; Kerslake, Thomas W.; Waters, Deborah L.

2004-01-01

Multi-kilogram class microsatellites with a PowerSphere electric power system are attractive for fulfilling a variety of potential NASA missions. However, PowerSphere polymer surfaces must be coated with a film that has suitable electrical sheet resistivity for electrostatic discharge control, be resistant to atomic oxygen attack, be transparent to ultraviolet light for composite structure curing and resist ultraviolet light induced darkening for efficient photovoltaic cell operation. In addition, the film must be tolerant of polymer layer folding associated with launch stowage of PowerSphere inflatable structures. An excellent film material candidate to meet these requirements is co-sputtered, indium oxide (In2O3) - tin oxide (SnO2), known as 'ITO', and magnesium fluoride (MgF2). While basic ITO-MgF2 film properties have been the subject of research over the last decade, further research is required in the areas of film durability for space-inflatable applications and precise film property control for large scale commercial production. In this paper, the authors present film durability results for a folded polymer substrate and film resistance to vacuum UV darkening. The authors discuss methods and results in the area of film sheet resistivity measurement and active control, particularly dual-channel, plasma emission line measurement of ITO and MgF2 plasma sources. ITO-MgF2 film polymer coupon preparation is described as well as film deposition equipment, procedures and film characterization. Durability testing methods are also described. The pre- and post-test condition of the films is assessed microscopically and electrically. Results show that an approx. 500A ITO-18vol% MgF2 film is a promising candidate to protect PowerSphere polymer surfaces for Earth orbit missions. Preliminary data also indicate that in situ film measurement methods are promising for active film resistivity control in future large scale production. Future film research plans are also

A comparison of two systems for lunar surface remote and mobile power applications

International Nuclear Information System (INIS)

Determan, W.R.; Otting, W.D.; Hunt, M.E.

1993-01-01

The free piston Stirling engine (FPSE) is now being developed by Mechanical Technology Incorporated (MTI) and NASA-LeRC for space power applications. Some conceptualizations of an isotope powered FPSE have been proposed. The performance characteristics of the proposed 2.5-kWe Stirling Isotope Power (STIP) system were developed for lunar surface remote and mobile applications. The Stirling system configuration uses a nonredundant power conversion system coupled to an annular heat source assembly (HSA) using an array of sodium heat pipes which transfer energy from the annular general-purpose heat source (GPHS) stack within the HSA to the Stirling heater head. The Stirling engine uses a dual-opposed piston design with heater head coupling. The engine coolers are connected to a single-pumped coolant loop, which rejects the cycle's waste heat to a radiator. Quantitative information, such as mass, area, and efficiency, are reported for the system. The results of a qualitative evaluation of the proposed STIP system against the desirable attributes of a lunar-based isotope power system are presented. Alternate configurations are also presented

High-power, format-flexible, 885-nm vertical-cavity surface-emitting laser arrays

Science.gov (United States)

Wang, Chad; Talantov, Fedor; Garrett, Henry; Berdin, Glen; Cardellino, Terri; Millenheft, David; Geske, Jonathan

2013-03-01

High-power, format flexible, 885 nm vertical-cavity surface-emitting laser (VCSEL) arrays have been developed for solid-state pumping and illumination applications. In this approach, a common VCSEL size format was designed to enable tiling into flexible formats and operating configurations. The fabrication of a common chip size on ceramic submount enables low-cost volume manufacturing of high-power VCSEL arrays. This base VCSEL chip was designed to be 5x3.33 mm2, and produced up to 50 Watts of peak continuous wave (CW) power. To scale to higher powers, multiple chips can be tiled into a combination of series or parallel configurations tailored to the application driver conditions. In actively cooled CW operation, the VCSEL array chips were packaged onto a single water channel cooler, and we have demonstrated 0.5x1, 1x1, and 1x3 cm2 formats, producing 150, 250, and 500 Watts of peak power, respectively, in under 130 A operating current. In QCW operation, the 1x3 cm2 VCSEL module, which contains 18 VCSEL array chips packaged on a single water cooler, produced over 1.3 kW of peak power. In passively cooled packages, multiple chip configurations have been developed for illumination applications, producing over 300 Watts of peak power in QCW operating conditions. These VCSEL chips use a substrate-removed structure to allow for efficient thermal heatsinking to enable high-power operation. This scalable, format flexible VCSEL architecture can be applied to wavelengths ranging from 800 to 1100 nm, and can be used to tailor emission spectral widths and build high-power hyperspectral sources.

Combustion-based power source for Venus surface missions

Science.gov (United States)

Miller, Timothy F.; Paul, Michael V.; Oleson, Steven R.

2016-10-01

The National Research Council has identified in situ exploration of Venus as an important mission for the coming decade of NASA's exploration of our solar system (Squyers, 2013 [1]). Heavy cloud cover makes the use of solar photovoltaics extremely problematic for power generation for Venus surface missions. In this paper, we propose a class of planetary exploration missions (for use on Venus and elsewhere) in solar-deprived situations where photovoltaics cannot be used, batteries do not provide sufficient specific energy and mission duration, and nuclear systems may be too costly or complex to justify or simply unavailable. Metal-fueled, combustion-based powerplants have been demonstrated for application in the terrestrial undersea environment. Modified or extended versions of the undersea-based systems may be appropriate for these sunless missions. We describe systems carrying lithium fuel and sulfur-hexafluoride oxidizer that have the potential for many days of operation in the sunless craters of the moon. On Venus a system level specific energy of 240 to 370 We-hr/kg should be possible if the oxidizer is brought from earth. By using either lithium or a magnesium-based alloy fuel, it may be possible to operate a similar system with CO2 derived directly from the Venus atmosphere, thus providing an estimated system specific energy of 1100 We+PV-hr/kg (the subscript refers to both electrical and mechanical power), thereby providing mission durations that enable useful scientific investigation. The results of an analysis performed by the NASA Glenn COMPASS team describe a mission operating at 2.3 kWe+PV for 5 days (120 h), with less than 260 kg power/energy system mass total. This lander would be of a size and cost suitable for a New Frontiers class of mission.

Experimental study on surface properties of the PMMA used in high power spark gaps

Science.gov (United States)

Han, Ruoyu; Wu, Jiawei; Ding, Weidong; Liu, Yunfei; Gou, Yang

2017-10-01

This paper studies the surface properties of the Polymethylmethacrylate (PMMA) insulator samples used in high power spark gaps. Experiments on surface morphology, surface profile, surface chemical composition and surface leakage current were performed. Metal particles ejected in tangent direction of discharge spots were researched on the sample surface. Three kinds of distinct bands were found on the surface after 1500 shots: colorless and transparent sinking band, black band, and grey powdered coating band. The thickness of the coating band was tens of microns and the maximum radial erosion rate was about 10 μm/C. Surface content analysis indicated that the powdered coating was a mixture of decomposed insulator material and electrode material oxides. In addition, leakage current significantly depended on water content in the chamber and presented an U-shape curve distribution along the insulator surface, in keeping with the amount of powdered coating due to shock waves. Possible reasons of the surface property changes were discussed. Electroconductive oxides of low valence states of Cu and W produced by the reactions between electrode materials and arc plasmas were considered to be the cause of dielectric performance degradation.

An Investigation of the Effectiveness of Solar Power on Navy Surface Combatants

Science.gov (United States)

2013-09-01

Delivering boost acceleration to automobiles in a process known as regenerative braking . • Serving as an uninterruptible power supply (UPS) to data...exchange membrane fuel cell, showing major components. From [12] .........................45 Figure 23. Depiction of a generic regenerative fuel cell...the highest three categories of annual sunlight. The majority of forward navy bases, as well as many ports that surface combatants pull into, are

100 kWe lunar/Mars surface power utilizing the SP-100 reactor with dynamic conversion

International Nuclear Information System (INIS)

Harty, R.B.; Mason, L.S.

1992-01-01

This paper reports on an integration study which was performed coupling an SP-100 reactor with either a Brayton of Stirling power conversion subsystem. a power level of 100 kWe was selected for the study. The power system was to be compatible with both the lunar and Mars surface environment and require no site preparation. In addition, the reactor was to have integral shielding and be completely self-contained, including its own auxiliary power for start-up. Initial reliability studies were performed to determine power conversion redundancy and engine module size. For the lunar environment, the reactor and primary coolant loop would be contained in a guard vessel to protect from a loss of primary loop containment. For the Mars environment, all refractory components including the reactor, primary coolant, and power conversion components would be contained in a vacuum vessel for protection against the CO 2 environment

The fractal geometry of nutrient exchange surfaces does not provide an explanation for 3/4-power metabolic scaling

Directory of Open Access Journals (Sweden)

Painter Page R

2005-08-01

Full Text Available Abstract Background A prominent theoretical explanation for 3/4-power allometric scaling of metabolism proposes that the nutrient exchange surface of capillaries has properties of a space-filling fractal. The theory assumes that nutrient exchange surface area has a fractal dimension equal to or greater than 2 and less than or equal to 3 and that the volume filled by the exchange surface area has a fractal dimension equal to or greater than 3 and less than or equal to 4. Results It is shown that contradicting predictions can be derived from the assumptions of the model. When errors in the model are corrected, it is shown to predict that metabolic rate is proportional to body mass (proportional scaling. Conclusion The presence of space-filling fractal nutrient exchange surfaces does not provide a satisfactory explanation for 3/4-power metabolic rate scaling.

Method for controlling a coolant liquid surface of cooling system instruments in an atomic power plant

International Nuclear Information System (INIS)

Monta, Kazuo.

1974-01-01

Object: To prevent coolant inventory within a cooling system loop in an atomic power plant from being varied depending on loads thereby relieving restriction of varied speed of coolant flow rate to lowering of a liquid surface due to short in coolant. Structure: Instruments such as a superheater, an evaporator, and the like, which constitute a cooling system loop in an atomic power plant, have a plurality of free liquid surface of coolant. Portions whose liquid surface is controlled and portions whose liquid surface is varied are adjusted in cross-sectional area so that the sum total of variation in coolant inventory in an instrument such as a superheater provided with an annulus portion in the center thereof and an inner cylindrical portion and a down-comer in the side thereof comes equal to that of variation in coolant inventory in an instrument such as an evaporator similar to the superheater. which is provided with an overflow pipe in its inner cylindrical portion or down-comer, thereby minimizing variation in coolant inventory of the entire coolant due to loads thus minimizing variation in varied speed of the coolant. (Kamimura, M.)

Effect of surface microstructure and wettability on plasma protein adsorption to ZnO thin films prepared at different RF powers

Energy Technology Data Exchange (ETDEWEB)

Huang Zhanyun; Chen Min; Chen Dihu [State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-Sen University, Guangzhou 510275 (China); Pan Shirong, E-mail: stscdh@mail.sysu.edu.c [Artificial Heart Lab, the 1st Affiliate Hospital of Sun Yat-Sen University, Guangzhou 510080 (China)

2010-10-01

In this paper, the adsorption behavior of plasma proteins on the surface of ZnO thin films prepared by radio frequency (RF) sputtering under different sputtering powers was studied. The microstructures and surface properties of the ZnO thin films were investigated by x-ray diffraction (XRD), scanning electron microscopy (SEM), UV-visible optical absorption spectroscopy and contact angle techniques. The results show that the ZnO thin films have better orientation of the (0 0 2) peak with increasing RF power, especially at around 160 W, and the optical band gap of the ZnO films varies from 3.2 to 3.4 eV. The contact angle test carried out by the sessile drop technique denoted a hydrophobic surface of the ZnO films, and the surface energy and adhesive work of the ZnO thin films decreased with increasing sputtering power. The amounts of human fibrinogen (HFG) and human serum albumin (HSA) adsorbing on the ZnO films and reference samples were determined by using enzyme-linked immunosorbent assay (ELISA). The results show that fewer plasma proteins and a smaller HFG/HSA ratio adsorb on the ZnO thin films' surface.

Engineering bacterial efflux pumps for solar-powered bioremediation of surface waters.

Science.gov (United States)

Kapoor, Vikram; Wendell, David

2013-05-08

Antibiotics are difficult to selectively remove from surface waters by present treatment methods. Bacterial efflux pumps have evolved the ability to discriminately expel antibiotics and other noxious agents via proton and ATP driven pathways. Here, we describe light-dependent removal of antibiotics by engineering the bacterial efflux pump AcrB into a proteovesicle system. We have created a chimeric protein with the requisite proton motive force by coupling AcrB to the light-driven proton pump Delta-rhodopsin (dR) via a glycophorin A transmembrane domain. This creates a solar powered protein material capable of selectively capturing antibiotics from bulk solutions. Using environmental water and direct sunlight, our AcrB-dR vesicles removed almost twice as much antibiotic as the treatment standard, activated carbon. Altogether, the AcrB-dR system provides an effective means of extracting antibiotics from surface waters as well as potential antibiotic recovery through vesicle solubilization.

EXPERIMENTAL EVALUATION OF THE THERMAL PERFORMANCE OF A WATER SHIELD FOR A SURFACE POWER REACTOR

International Nuclear Information System (INIS)

Reid, Robert S.; Pearson, J. Bosie; Stewart, Eric T.

2007-01-01

Water based reactor shielding is being investigated for use on initial lunar surface power systems. A water shield may lower overall cost (as compared to development cost for other materials) and simplify operations in the setup and handling. The thermal hydraulic performance of the shield is of significant interest. The mechanism for transferring heat through the shield is natural convection. Natural convection in a 100 kWt lunar surface reactor shield design is evaluated with 2 kW power input to the water in the Water Shield Testbed (WST) at the NASA Marshall Space Flight Center. The experimental data from the WST is used to validate a CFD model. Performance of the water shield on the lunar surface is then predicted with a CFD model anchored to test data. The experiment had a maximum water temperature of 75 C. The CFD model with 1/6-g predicts a maximum water temperature of 88 C with the same heat load and external boundary conditions. This difference in maximum temperature does not greatly affect the structural design of the shield, and demonstrates that it may be possible to use water for a lunar reactor shield.

Experimental Evaluation of the Thermal Performance of a Water Shield for a Surface Power Reactor

International Nuclear Information System (INIS)

Pearson, J. Boise; Stewart, Eric T.; Reid, Robert S.

2007-01-01

Water based reactor shielding is being investigated for use on initial lunar surface power systems. A water shield may lower overall cost (as compared to development cost for other materials) and simplify operations in the setup and handling. The thermal hydraulic performance of the shield is of significant interest. The mechanism for transferring heat through the shield is natural convection. Natural convection in a 100 kWt lunar surface reactor shield design is evaluated with 2 kW power input to the water in the Water Shield Testbed (WST) at the NASA Marshall Space Flight Center. The experimental data from the WST is used to validate a CFD model. Performance of the water shield on the lunar surface is then predicted with a CFD model anchored to test data. The experiment had a maximum water temperature of 75 deg. C. The CFD model with 1/6-g predicts a maximum water temperature of 88 deg. C with the same heat load and external boundary conditions. This difference in maximum temperature does not greatly affect the structural design of the shield, and demonstrates that it may be possible to use water for a lunar reactor shield

EXPERIMENTAL EVALUATION OF THE THERMAL PERFORMANCE OF A WATER SHIELD FOR A SURFACE POWER REACTOR

Energy Technology Data Exchange (ETDEWEB)

REID, ROBERT S. [Los Alamos National Laboratory; PEARSON, J. BOSIE [Los Alamos National Laboratory; STEWART, ERIC T. [Los Alamos National Laboratory

2007-01-16

Water based reactor shielding is being investigated for use on initial lunar surface power systems. A water shield may lower overall cost (as compared to development cost for other materials) and simplify operations in the setup and handling. The thermal hydraulic performance of the shield is of significant interest. The mechanism for transferring heat through the shield is natural convection. Natural convection in a 100 kWt lunar surface reactor shield design is evaluated with 2 kW power input to the water in the Water Shield Testbed (WST) at the NASA Marshall Space Flight Center. The experimental data from the WST is used to validate a CFD model. Performance of the water shield on the lunar surface is then predicted with a CFD model anchored to test data. The experiment had a maximum water temperature of 75 C. The CFD model with 1/6-g predicts a maximum water temperature of 88 C with the same heat load and external boundary conditions. This difference in maximum temperature does not greatly affect the structural design of the shield, and demonstrates that it may be possible to use water for a lunar reactor shield.

Dry Etch Black Silicon with Low Surface Damage: Effect of Low Capacitively Coupled Plasma Power

DEFF Research Database (Denmark)

Iandolo, Beniamino; Plakhotnyuk, Maksym; Gaudig, Maria

2017-01-01

Black silicon fabricated by reactive ion etch (RIE) is promising for integration into silicon solar cells thanks to its excellent light trapping ability. However, intensive ion bombardment during the RIE induces surface damage, which results in enhanced surface recombination velocity. Here, we pr...... carrier lifetime thanks to reduced ion energy. Surface passivation using atomic layer deposition of Al2O3 improves the effective lifetime to 7.5 ms and 0.8 ms for black silicon n- and p-type wafers, respectively.......Black silicon fabricated by reactive ion etch (RIE) is promising for integration into silicon solar cells thanks to its excellent light trapping ability. However, intensive ion bombardment during the RIE induces surface damage, which results in enhanced surface recombination velocity. Here, we...... present a RIE optimization leading to reduced surface damage while retaining excellent light trapping and low reflectivity. In particular, we demonstrate that the reduction of the capacitively coupled power during reactive ion etching preserves a reflectance below 1% and improves the effective minority...

Model of thermal fatigue of a copper surface under the action of high-power microwaves

Science.gov (United States)

Kuzikov, S. V.; Plotkin, M. E.

2007-10-01

The accelerating structures of modern supercolliders, as well as the components of high-power microwave electron devices operated in strong cyclic electromagnetic fields should have long lifetimes. Along with the electric breakdown, the surfaces of these microwave components deteriorate and their lifetimes decrease due to thermal strains and subsequent mechanical loads on the surface metal layer. The elementary theory of thermal fatigue was developed in the 1970s. In particular, a model of metal as a continuous medium was considered. Within the framework of this model, thermal fatigue is caused by the strains arising between the hot surface layer and the cold internal layer of the metal. However, this theory does not describe all the currently available experimental data. In particular, the notion of “safe temperature” of the heating, i.e., temperature at which the surface is not destroyed during an arbitrarily long series of pulses, which was proposed in the theoretical model, is in poor agreement with the experiment performed in the Stanford Linear Accelerator Center (SLAC, USA). In this work, the thermal-fatigue theory is developed on the basis of consideration of the copper polycrystalline structure. The necessity to take it into account was demonstrated by the results of the SLAC experiment, in which a change in the mutual orientation of copper grains and the formation of cracks at their boundaries was recorded for the first time. The developed theory makes it possible to use the experimental data to refine the coefficients in the obtained formulas for the lifetime of the metal surface and to predict the number of microwave pulses before its destruction as a function of the radiation power, the surface-temperature increase at the pulse peak, and the pulse duration.

Inhibition of charge recombination for enhanced dye-sensitized solar cells and self-powered UV sensors by surface modification

Energy Technology Data Exchange (ETDEWEB)

Chu, Liang, E-mail: chuliang@njupt.edu.cn [Advanced Energy Technology Center, Nanjing University of Posts and Telecommunications (NUPT), Nanjing 210046 (China); Wuhan National Laboratory for Optoelectronics (WNLO)-School of Physics, Huazhong University of Science and Technology (HUST), Wuhan 430074 (China); Qin, Zhengfei; Liu, Wei [School of Materials Science and Engineering (SMSE), Nanjing University of Posts and Telecommunications (NUPT), Nanjing 210046 (China); Ma, Xin’guo, E-mail: maxg2013@sohu.com [Hubei Collaborative Innovation Center for High-efficiency Utilization of Solar Energy, Hubei University of Technology, Wuhan 430068 (China)

2016-12-15

Graphical abstract: Inhibition of charge recombination was utilized to prolong electrode lifetime in dye-sensitized solar cells (DSSCs) and self-powered UV sensors based on TiO{sub 2}-modified SnO{sub 2} photoelectrodes. The electrochemical impedance spectroscopy and open-circuit voltage decay measurements indicated that the electron lifetime was significantly prolonged in DSSCs after TiO{sub 2} modification. And in self-powered UV sensors, the sensitivity and response time were enhanced. - Highlights: • The surface modification to inhibit charge recombination was utilized in photovoltaic devices. • Inhibition of charge recombination can prolong electrode lifetime in photovoltaic devices. • Enhanced DSSCs and self-powered UV sensors based on SnO{sub 2} photoelectrodes were obtained by TiO{sub 2} modification. - Abstract: The surface modification to inhibit charge recombination was utilized in dye-sensitized solar cells (DSSCs) and self-powered ultraviolet (UV) sensors based on SnO{sub 2} hierarchical microspheres by TiO{sub 2} modification. For DSSCs with SnO{sub 2} photoelectrodes modified by TiO{sub 2}, the power conversion efficiency (PCE) was improved from 1.40% to 4.15% under standard AM 1.5G illumination (100 mW/cm{sup 2}). The electrochemical impedance spectroscopy and open-circuit voltage decay measurements indicated that the charge recombination was effectively inhibited, resulting in long electron lifetime. For UV sensors with SnO{sub 2} photoelectrodes modified by TiO{sub 2} layer, the self-powered property was more obvious, and the sensitivity and response time were enhanced from 91 to 6229 and 0.15 s to 0.055 s, respectively. The surface modification can engineer the interface energy to inhibit charge recombination, which is a desirable approach to improve the performance of photoelectric nanodevice.

Path dependence, fragmented property rights and the slow diffusion of high throughput technologies in inter-war British coal mining

Energy Technology Data Exchange (ETDEWEB)

Peter Scott

2006-01-15

This article examines the importance of path dependence effects in impeding the diffusion of high throughput mechanized mining systems in the British coal industry. It demonstrates that the industry had become 'locked in' to low throughput underground haulage technology, on account of institutional interrelatedness between Britain's traditional practice of extensive in-seam mining and its unique system of fragmented, privately owned mineral royalties. Fragmented royalties prevented the concentration of workings and introduction of high throughput main haulage systems that underpinned the rapid productivity growth of European producers. Meanwhile, technical interrelatedness between the haulage systems taking coal to the pit shaft and operations further 'upstream' created bottlenecks which both slowed the overall rate of mechanization and limited the productivity gains from the mechanization that did occur.

Haulage trucks model with four electric separate wheel drives

Directory of Open Access Journals (Sweden)

R. Setlak

2005-02-01

Full Text Available This article contains a course of work of the construction of a vehicle model that has four electrical motors built into each wheel. During the project two models of a vehicle were constructed. A microprocessor based control system has also been designed and built. A vehicle is controlled by a steering unit which contains a steering wheel with a force feedback system, push buttons, an accelerator and a brake. The connection between a steering unit and a model is realized by interface RS-485. The driving motors are dc motors with permanent magnets. Power supply consists of an acid battery located in the vehicle. The vehicle control system is divided into two parts. The first part is built into the vehicle and operates as a vehicle main control system and the second is built into a steering unit and operates as the main control steering system.

Experimental Investigation on the Detection of Multiple Surface Cracks Using Vibrothermography with a Low-Power Piezoceramic Actuator.

Science.gov (United States)

Xu, Changhang; Xie, Jing; Zhang, Wuyang; Kong, Qingzhao; Chen, Guoming; Song, Gangbing

2017-11-23

Vibrothermography often employs a high-power actuator to generate heat on a specimen to reveal damage, however, the high-power actuator brings inconvenience to the application and possibly introduces additional damage to the inspected objects. This study uses a low-power piezoceramic transducer as the actuator of vibrothermography and explores its ability to detect multiple surface cracks in a metal part. Experiments were conducted on a thin aluminum beam with three cracks in different orientations. Detailed analyses of both thermograms and temperature data are presented to validate the proposed vibrothermography method. To further investigate the performance of the proposed vibrothermography method, we experimentally studied the effects of several critical factors, including the amplitude of excitation signal, specimen constraints, relative position between the transducer and cracks (the transducer is mounted on the same or the opposite side with the cracks). The results demonstrate that all cracks can be detected conveniently and simultaneously by using the proposed low-power vibrothermography. We also found that the magnitude of excitation signal and the specimen constraints have a great influence on detection results. Combined with effective data processing methods, such as Fourier transformation employed in this study, the proposed method provides a promising potential to detect multiple cracks on a metal surface in a safe and effective manner.

Dual-purpose self-deliverable lunar surface PV electrical power system

Science.gov (United States)

Arnold, Jack H.; Harris, David W.; Cross, Eldon R.; Flood, Dennis J.

1991-01-01

A safe haven and work supported PV power systems on the lunar surface will likely be required by NASA in support of the manned outpost scheduled for the post-2000 lunar/Mars exploration and colonization initiative. Initial system modeling and computer analysis shows that the concept is workable and contains no major high risk technology issues which cannot be resolved in the circa 2000 to 2025 timeframe. A specific selection of the best suited type of electric thruster has not been done; the initial modeling was done using an ion thruster, but Rocketdyne must also evaluate arc and resisto-jets before a final design can be formulated. As a general observation, it appears that such a system can deliver itself to the Moon using many system elements that must be transported as dead payload mass in more conventional delivery modes. It further appears that a larger power system providing a much higher safe haven power level is feasible if this delivery system is implemented, perhaps even sufficient to permit resource prospecting and/or lab experimentation. The concept permits growth and can be expanded to include cargo transport such as habitat and working modules. In short, the combined payload could be manned soon after landing and checkout. NASA has expended substantial resources in the development of electric propulsion concepts and hardware that can be applied to a lunar transport system such as described herein. In short, the paper may represent a viable mission on which previous investments play an invaluable role. A more comprehensive technical paper which embodies second generation analysis and system size will be prepared for near-term presentation.

Behavior of a thermoelectric power generation device based on solar irradiation and the earth’s surface-air temperature difference

International Nuclear Information System (INIS)

Zhang, Zhe; Li, Wenbin; Kan, Jiangming

2015-01-01

Highlights: • A technical solution to the power supply of wireless sensor networks is presented. • The low voltage produced by TEG is boosted from less than 1 V to more than 4 V. • An output current and voltage of TEG device is acquired as 21.47 mA and 221 mV. • The device successfully provides output power 4.7 mW in no electricity conditions. • The thermo-economic value of TEG device is demonstrated. - Abstract: Motivated by the limited power supply of wireless sensors used to monitor the natural environment, for example, in forests, this study presents a technical solution by recycling solar irradiation heat using thermoelectric generators. Based on solar irradiation and the earth’s surface-air temperature difference, a new type of thermoelectric power generation device has been devised, the distinguishing features of which include the application of an all-glass heat-tube-type vacuum solar heat collection pipe to absorb and transfer solar energy without a water medium and the use of a thin heat dissipation tube to cool the earth surface air temperature. The effects of key parameters such as solar illumination, air temperature, load resistance, the proportional coefficient, output power and power generation efficiency for thermoelectric energy conversion are analyzed. The results of realistic outdoor experiments show that under a state of regular illumination at 3.75 × 10 4 lx, using one TEG module, the thermoelectric device is able to boost the voltage obtained from the natural solar irradiation from 221 mV to 4.41 V, with an output power of 4.7 mW. This means that the electrical energy generated can provide the power supply for low power consumption components, such as low power wireless sensors, ZigBee modules and other low power loads

Performance Evaluation Criterion at Equal Pumping Power for Enhanced Performance Heat Transfer Surfaces

Directory of Open Access Journals (Sweden)

Rajendra Karwa

2013-01-01

Full Text Available The existing equations for the thermal performance evaluation, at equal pumping power for the artificially roughened and smooth surfaced multitube and rectangular duct heat exchangers, have been critically reviewed because the literature survey indicates that a large number of researchers have not interpreted these equations correctly. Three of the most widely used equations have been restated with clearly defined constraints and conditions for their application. Two new equations have been developed for the design constraints not covered earlier.

World wide developments in shortwall and wide web mining techniques

Energy Technology Data Exchange (ETDEWEB)

Pollard, T

1975-11-01

The paper describes the progress to date with continuous pillar extraction, and how the typical longwall powered support has been modified to be both strong enough and stable enough to provide roof support for very wide webs. It also describes the operating systems which have been specially designed. The next stages of development are discussed, particularly the provision of continuous conveyor haulage in place of the present-day shuttle car. The author suggests that marrying American coal-getting technology and British roof support technology might increase productivity.

Investigation of the delay time distribution of high power microwave surface flashover

Science.gov (United States)

Foster, J.; Krompholz, H.; Neuber, A.

2011-01-01

Characterizing and modeling the statistics associated with the initiation of gas breakdown has proven to be difficult due to a variety of rather unexplored phenomena involved. Experimental conditions for high power microwave window breakdown for pressures on the order of 100 to several 100 torr are complex: there are little to no naturally occurring free electrons in the breakdown region. The initial electron generation rate, from an external source, for example, is time dependent and so is the charge carrier amplification in the increasing radio frequency (RF) field amplitude with a rise time of 50 ns, which can be on the same order as the breakdown delay time. The probability of reaching a critical electron density within a given time period is composed of the statistical waiting time for the appearance of initiating electrons in the high-field region and the build-up of an avalanche with an inherent statistical distribution of the electron number. High power microwave breakdown and its delay time is of critical importance, since it limits the transmission through necessary windows, especially for high power, high altitude, low pressure applications. The delay time distribution of pulsed high power microwave surface flashover has been examined for nitrogen and argon as test gases for pressures ranging from 60 to 400 torr, with and without external UV illumination. A model has been developed for predicting the discharge delay time for these conditions. The results provide indications that field induced electron generation, other than standard field emission, plays a dominant role, which might be valid for other gas discharge types as well.

American National Standard: criteria and guidelines for assessing capability for surface faulting at nuclear power plant sites

International Nuclear Information System (INIS)

Anon.

1982-01-01

This standard provides applicants and consultants with criteria and guidelines for investigations directed toward the assessment of the capability for surface faulting at nuclear power plant sites. Assessment of vibratory ground motion resulting from faulting is not treated in these guidelines

Chemical effluents in surface waters from nuclear power plants. Quarterly progress report

International Nuclear Information System (INIS)

Harrison, F.L.

1978-01-01

The objectives of this research project are threefold: to obtain data on the behavior of potentially toxic substances introduced into surface waters from nuclear power plants; to determine the magnitude of the impact of these substances on representative and economically important aquatic species; and to develop models with which to predict the partitioning of these substances among the abiotic aquatic compartments. To fulfill these objectives in our investigation of copper, we are determining copper partitioning in marine and freshwater systems, evaluating the toxicity of copper to representative aquatic organisms, and developing a mathematical model to predict copper partitioning

The use of large surface area for particle and power deposition

International Nuclear Information System (INIS)

Seigneur, A.; Guilhem, D.; Hogan, J.

1993-01-01

Since the parallel heat flux passing through the LCFS has increased dramatically with the size of machines one has to cope with very large particle and power fluxes on the limiters. Thus the size of the limiters has been increased by the use of inner bumper limiters (for example in JET, TFTR, TORE-SUPRA and JT60). The 'exponential-sine' model is widely used to estimate the heat flux (Q) to a wall for a plasma flux surface with incident angle θ. The model predict Q = q || (0) sinθ e -ρ/λ q + q(0) cosθ e -ρ/λ q , (where θ=0 o when the flux surface is exactly tangential to the limiting surface), ρ is the minor radius measured from the last closed flux surface (LCFS), λ q is the SOL decay length of the heat flux density and q(0) is the heat flux density at the last closed surface. If we approximate the heat flux as Q = q || (0) e -ρ/λ q sin(θ+α), with α ≡ tan -1 [q(0)/q || (0)], then α can be interpreted as an effective 'minimum angle of incidence'. Under conditions where the geometric angle θ has been made almost grazing (below 5 o ) the predictions of the simplest model (with α=0 o ) is not adequate to represent the observation made in TORE-SUPRA; a similar result is found in TFTR. Experimental observations of heat and particle deposition on the large area limiter on the inner wall of TORE-SUPRA are presented. These results have been analyzed with a Monte Carlo code (THOR) describing the diffusion of hydrogenic particles across the LCFS to the limiting objects in the Scrape Off Layer (SOL), and by impurity generation calculations using the full 'exponential-sine' model (α ≠ 0) used as input to an impurity (carbon) Monte Carlo code (BBQ). (author) 6 refs., 3 figs., 1 tab

Estimation of Radial Runout

OpenAIRE

Nilsson, Martin

2007-01-01

The demands for ride comfort quality in today's long haulage trucks are constantly growing. A part of the ride comfort problems are represented by internal vibrations caused by rotating mechanical parts. This thesis work focus on the vibrations generated from radial runout on the wheels. These long haulage trucks travel long distances on smooth highways, with a constant speed of 90 km/h resulting in a 7 Hz oscillation. This frequency creates vibrations in the cab, which can be found annoying....

Origin of Power Laws for Reactions at Metal Surfaces Mediated by Hot Electrons

DEFF Research Database (Denmark)

Olsen, Thomas; Schiøtz, Jakob

2009-01-01

A wide range of experiments have established that certain chemical reactions at metal surfaces can be driven by multiple hot-electron-mediated excitations of adsorbates. A high transient density of hot electrons is obtained by means of femtosecond laser pulses and a characteristic feature of such...... density functional theory and the delta self-consistent field method. With a simplifying assumption, the power law becomes exact and we obtain a simple physical interpretation of the exponent n, which represents the number of adsorbate vibrational states participating in the reaction....

Entropy Generation Analysis of Power-Law Non-Newtonian Fluid Flow Caused by Micropatterned Moving Surface

Directory of Open Access Journals (Sweden)

M. H. Yazdi

2014-01-01

Full Text Available In the present study, the first and second law analyses of power-law non-Newtonian flow over embedded open parallel microchannels within micropatterned permeable continuous moving surface are examined at prescribed surface temperature. A similarity transformation is used to reduce the governing equations to a set of nonlinear ordinary differential equations. The dimensionless entropy generation number is formulated by an integral of the local rate of entropy generation along the width of the surface based on an equal number of microchannels and no-slip gaps interspersed between those microchannels. The velocity, the temperature, the velocity gradient, and the temperature gradient adjacent to the wall are substituted into this equation resulting from the momentum and energy equations obtained numerically by Dormand-Prince pair and shooting method. Finally, the entropy generation numbers, as well as the Bejan number, are evaluated. It is noted that the presence of the shear thinning (pseudoplastic fluids creates entropy along the surface, with an opposite effect resulting from shear thickening (dilatant fluids.

Characterization of the inside and outside oxide surfaces of irradiated pressure tubes of Embalse nuclear power plant

International Nuclear Information System (INIS)

Bordoni, Roberto A.; Olmedo, Ana M.

2004-01-01

The inside and outside surfaces of two pressure tubes (PT) removed from Embalse nuclear power plant (CNE) after 10 of effective full power years (EFPY) were characterized. The oxide thickness of both faces, in different zones, was also measured. The inside surfaces of both PTs, B-102 (A-14) and B-298 (L-12), were covered with a black oxide that replicates the original PT surface. A network of microcracks perpendicular to the inside surface in contact with the coolant was found. In some cases, near the outlet of the PT, some spalling of the oxide was also found. These small microcracks and spalling do not affect the protective character of the oxide since a thickness about 5 or 6 μm of an undamaged oxide is found at the metal/oxide interface side. The oxide thickness changes between approximately 6 to 12 μm for B-102 tube and around 7 to 15 μm for B-298 tube. The average corrosion rate is 1.16 μm/10 4 HH for B-102 tube and 1.35 μm/10 4 HH for B-298 tube at 5.8 m position for both PTs. These corrosion rates show good corrosion behaviour of CNE PTs. The average corrosion rate of the inside surface of the PTs depends on the coolant temperature but not on fast neutron flux. The outside oxide film is black, shiny, compact and protective, replicating also the original surface. The oxide thickness changes between 2 to 6.5 μm in B-102 tube and between 1.8 to 3.7 μm B-298 tube. These oxide thicknesses are within the values reported for PTs in CANDU Stations. (author) [es

Graphite anode surface modification with controlled reduction of specific aryl diazonium salts for improved microbial fuel cells power output.

Science.gov (United States)

Picot, Matthieu; Lapinsonnière, Laure; Rothballer, Michael; Barrière, Frédéric

2011-10-15

Graphite electrodes were modified with reduction of aryl diazonium salts and implemented as anodes in microbial fuel cells. First, reduction of 4-aminophenyl diazonium is considered using increased coulombic charge density from 16.5 to 200 mC/cm(2). This procedure introduced aryl amine functionalities at the surface which are neutral at neutral pH. These electrodes were implemented as anodes in "H" type microbial fuel cells inoculated with waste water, acetate as the substrate and using ferricyanide reduction at the cathode and a 1000 Ω external resistance. When the microbial anode had developed, the performances of the microbial fuel cells were measured under acetate saturation conditions and compared with those of control microbial fuel cells having an unmodified graphite anode. We found that the maximum power density of microbial fuel cell first increased as a function of the extent of modification, reaching an optimum after which it decreased for higher degree of surface modification, becoming even less performing than the control microbial fuel cell. Then, the effect of the introduction of charged groups at the surface was investigated at a low degree of surface modification. It was found that negatively charged groups at the surface (carboxylate) decreased microbial fuel cell power output while the introduction of positively charged groups doubled the power output. Scanning electron microscopy revealed that the microbial anode modified with positively charged groups was covered by a dense and homogeneous biofilm. Fluorescence in situ hybridization analyses showed that this biofilm consisted to a large extent of bacteria from the known electroactive Geobacter genus. In summary, the extent of modification of the anode was found to be critical for the microbial fuel cell performance. The nature of the chemical group introduced at the electrode surface was also found to significantly affect the performance of the microbial fuel cells. The method used for

Discharge Characteristics of Series Surface/Packed-Bed Discharge Reactor Diven by Bipolar Pulsed Power

International Nuclear Information System (INIS)

Hu Jian; Jiang Nan; Li Jie; Shang Kefeng; Lu Na; Wu Yan; Mizuno Akira

2016-01-01

The discharge characteristics of the series surface/packed-bed discharge (SSPBD) reactor driven by bipolar pulse power were systemically investigated in this study. In order to evaluate the advantages of the SSPBD reactor, it was compared with traditional surface discharge (SD) reactor and packed-bed discharge (PBD) reactor in terms of the discharge voltage, discharge current, and ozone formation. The SSPBD reactor exhibited a faster rising time and lower tail voltage than the SD and PBD reactors. The distribution of the active species generated in different discharge regions of the SSPBD reactor was analyzed by optical emission spectra and ozone analysis. It was found that the packed-bed discharge region (3.5 mg/L), rather than the surface discharge region (1.3 mg/L) in the SSPBD reactor played a more important role in ozone generation. The optical emission spectroscopy analysis indicated that more intense peaks of the active species (e.g. N2 and OI) in the optical emission spectra were observed in the packed-bed region. (paper)

Impacts of propagating, frustrated and surface modes on radiative, electrical and thermal losses in nanoscale-gap thermophotovoltaic power generators

Science.gov (United States)

Bernardi, Michael P.; Dupré, Olivier; Blandre, Etienne; Chapuis, Pierre-Olivier; Vaillon, Rodolphe; Francoeur, Mathieu

2015-01-01

The impacts of radiative, electrical and thermal losses on the performances of nanoscale-gap thermophotovoltaic (nano-TPV) power generators consisting of a gallium antimonide cell paired with a broadband tungsten and a radiatively-optimized Drude radiator are analyzed. Results reveal that surface mode mediated nano-TPV power generation with the Drude radiator outperforms the tungsten radiator, dominated by frustrated modes, only for a vacuum gap thickness of 10 nm and if both electrical and thermal losses are neglected. The key limiting factors for the Drude- and tungsten-based devices are respectively the recombination of electron-hole pairs at the cell surface and thermalization of radiation with energy larger than the cell absorption bandgap. A design guideline is also proposed where a high energy cutoff above which radiation has a net negative effect on nano-TPV power output due to thermal losses is determined. It is shown that the power output of a tungsten-based device increases by 6.5% while the cell temperature decreases by 30 K when applying a high energy cutoff at 1.45 eV. This work demonstrates that design and optimization of nano-TPV devices must account for radiative, electrical and thermal losses. PMID:26112658

The Development of Power Distribution Law in Transmission of Active Road Based on the Analysis of the Power Factors in the Coupling Device

Directory of Open Access Journals (Sweden)

V. A. Gorelov

2016-01-01

Full Text Available Effective delivery of indivisible bulky and heavy loads whose weight can reach hundreds tons is of particular importance for development of various sectors of economy and support of defense capability. Special road trains provide open road transportation and off-road haulage of this kind of goods, but in difficult traffic environment their using capabilities are significantly restricted by a lack of the road-ability. For a road train to reach the better road-ability is possible by increasing the number of drive wheels. This can be achieved through the use of an activetrailer as its part. The effectiveness of using this drive may be estimated through comparison of the road train road-ability with the turned on and turned off passive and active semitrailer in different road environment. A mathematical model of the dynamics of the two-link semitrailer truck was created to solve the problem of comparing dynamic characteristics of the road trains with the passive and active semitrailer. The developed mathematical model of the four-axle tractor and three-axle semitrailer was implemented in the MATLAB® Simulink. It was revealed that in some traffic environments it is advisable to disable the semitrailer drive. A drive control algorithm of semitrailer wheels based on the analysis of the forces in the coupling device was proposed. Data from the sensors installed in the pin of the coupling device serve as a primary source of information for the control system. Test runs enabled us to define control limits for the drive control system. The article considers three cases to use the power of traction motors of the semitrailer in a predetermined range. A number of numerical experiments have been conducted to define dynamic qualities of the road trains in different cases of using semitrailer power. The analysis of results allowed us to draw conclusion that using a system of the semitrailer drive to be connected enables increasing efficiency of the road train

The Effect of Surface Tension on the Gravity-driven Thin Film Flow of Newtonian and Power-law Fluids

Science.gov (United States)

Hu, Bin; Kieweg, Sarah L.

2012-01-01

Gravity-driven thin film flow is of importance in many fields, as well as for the design of polymeric drug delivery vehicles, such as anti-HIV topical microbicides. There have been many prior works on gravity-driven thin films. However, the incorporation of surface tension effect has not been well studied for non-Newtonian fluids. After surface tension effect was incorporated into our 2D (i.e. 1D spreading) power-law model, we found that surface tension effect not only impacted the spreading speed of the microbicide gel, but also had an influence on the shape of the 2D spreading profile. We observed a capillary ridge at the front of the fluid bolus. Previous literature shows that the emergence of a capillary ridge is strongly related to the contact line fingering instability. Fingering instabilities during epithelial coating may change the microbicide gel distribution and therefore impact how well it can protect the epithelium. In this study, we focused on the capillary ridge in 2D flow and performed a series of simulations and showed how the capillary ridge height varies with other parameters, such as surface tension coefficient, inclination angle, initial thickness, and power-law parameters. As shown in our results, we found that capillary ridge height increased with higher surface tension, steeper inclination angle, bigger initial thickness, and more Newtonian fluids. This study provides the initial insights of how to optimize the flow and prevent the appearance of a capillary ridge and fingering instability. PMID:23687391

A gas-cooled reactor surface power system

International Nuclear Information System (INIS)

Lipinski, R.J.; Wright, S.A.; Lenard, R.X.; Harms, G.A.

1999-01-01

A human outpost on Mars requires plentiful power to assure survival of the astronauts. Anywhere from 50 to 500 kW of electric power (kWe) will be needed, depending on the number of astronauts, level of scientific activity, and life-cycle closure desired. This paper describes a 250-kWe power system based on a gas-cooled nuclear reactor with a recuperated closed Brayton cycle conversion system. The design draws upon the extensive data and engineering experience developed under the various high-temperature gas cooled reactor programs and under the SP-100 program. The reactor core is similar in power and size to the research reactors found on numerous university campuses. The fuel is uranium nitride clad in Nb1%Zr, which has been extensively tested under the SP-100 program. The fuel rods are arranged in a hexagonal array within a BeO block. The BeO softens the spectrum, allowing better use of the fuel and stabilizing the geometry against deformation during impact or other loadings. The system has a negative temperature feedback coefficient so that the power level will automatically follow a variable load without the need for continuous adjustment of control elements. Waste heat is removed by an air-cooled heat exchanger using cold Martian air. The amount of radioactivity in the reactor at launch is very small (less than a Curie, and about equal to a truckload of uranium ore). The system will need to be engineered so that criticality can not occur for any launch accident. This system is also adaptable for electric propulsion or life-support during transit to and from Mars. copyright 1999 American Institute of Physics

A gas-cooled reactor surface power system

International Nuclear Information System (INIS)

Lipinski, Ronald J.; Wright, Steven A.; Lenard, Roger X.; Harms, Gary A.

1999-01-01

A human outpost on Mars requires plentiful power to assure survival of the astronauts. Anywhere from 50 to 500 kW of electric power (kWe) will be needed, depending on the number of astronauts, level of scientific activity, and life-cycle closure desired. This paper describes a 250-kWe power system based on a gas-cooled nuclear reactor with a recuperated closed Brayton cycle conversion system. The design draws upon the extensive data and engineering experience developed under the various high-temperature gas cooled reactor programs and under the SP-100 program. The reactor core is similar in power and size to the research reactors found on numerous university campuses. The fuel is uranium nitride clad in Nb1%Zr, which has been extensively tested under the SP-100 program. The fuel rods are arranged in a hexagonal array within a BeO block. The BeO softens the spectrum, allowing better use of the fuel and stabilizing the geometry against deformation during impact or other loadings. The system has a negative temperature feedback coefficient so that the power level will automatically follow a variable load without the need for continuous adjustment of control elements. Waste heat is removed by an air-cooled heat exchanger using cold Martian air. The amount of radioactivity in the reactor at launch is very small (less than a Curie, and about equal to a truckload of uranium ore). The system will need to be engineered so that criticality can not occur for any launch accident. This system is also adaptable for electric propulsion or life-support during transit to and from Mars

A Gas-Cooled Reactor Surface Power System

Energy Technology Data Exchange (ETDEWEB)

Harms, G.A.; Lenard, R.X.; Lipinski, R.J.; Wright, S.A.

1998-11-09

A human outpost on Mars requires plentiful power to assure survival of the astronauts. Anywhere from 50 to 500 kW of electric power (kWe) will be needed, depending on the number of astronauts, level of scientific activity, and life- cycle closure desired. This paper describes a 250-kWe power system based on a gas-cooled nuclear reactor with a recuperated closed Brayton cycle conversion system. The design draws upon the extensive data and engineering experience developed under the various high-temperature gas cooled reactor programs and under the SP-100 program. The reactor core is similar in power and size to the research reactors found on numerous university campuses. The fuel is uranium nitide clad in Nb 1 %Zr, which has been extensively tested under the SP-I 00 program The fiel rods are arranged in a hexagonal array within a BeO block. The BeO softens the spectrum, allowing better use of the fbel and stabilizing the geometty against deformation during impact or other loadings. The system has a negative temperature feedback coefficient so that the power level will automatically follow a variable load without the need for continuous adjustment of control elements. Waste heat is removed by an air-cooled heat exchanger using cold Martian air. The amount of radioactivity in the reactor at launch is very small (less than a Curie, and about equal to a truckload of uranium ore). The system will need to be engineered so that criticality cannot occur for any launch accident. This system is also adaptable for electric propulsion or life-support during transit to and from Mars.

Solid-Core, Gas-Cooled Reactor for Space and Surface Power

International Nuclear Information System (INIS)

King, Jeffrey C.; El-Genk, Mohamed S.

2006-01-01

The solid-core, gas-cooled, Submersion-Subcritical Safe Space (S and 4) reactor is developed for future space power applications and avoidance of single point failures. The Mo-14%Re reactor core is loaded with uranium nitride fuel in enclosed cavities, cooled by He-30%Xe, and sized to provide 550 kWth for seven years of equivalent full power operation. The beryllium oxide reflector disassembles upon impact on water or soil. In addition to decreasing the reactor and shadow shield mass, Spectral Shift Absorber (SSA) materials added to the reactor core ensure that it remains subcritical in the worst-case submersion accident. With a 0.1 mm thick boron carbide coating on the outside surface of the core block and 0.25 mm thick iridium sleeves around the fuel stacks, the reflector outer diameter is 43.5 cm and the combined reactor and shadow shield mass is 935.1 kg. With 12.5 atom% gadolinium-155 added to the fuel, 2.0 mm diameter gadolinium-155 sesquioxide intersititial pins, and a 0.1 mm thick gadolinium-155 sesquioxide coating, the S and 4 reactor has a slightly smaller reflector outer diameter of 43.0 cm, and a total reactor and shield mass of 901.7 kg. With 8.0 atom% europium-151 added to the fuel, 2.0 mm diameter europium-151 sesquioxide interstitial pins, and a 0.1 mm thick europium-151 sesquioxide coating, the reflector's outer diameter and the total reactor and shield mass are further reduced to 41.5 cm and 869.2 kg, respectively

Surface enhanced Raman scattering as an in-reactor monitor of phenomena of interest to the Nuclear Power Industry

International Nuclear Information System (INIS)

Devine, T.M.

1994-01-01

Surface enhanced Raman spectroscopy (SERS) is proposed as a technique for monitoring in situ the passive films and corrosion products that form on the surfaces of alloys of interest in nuclear power plants. The technique is a highly sensitive procedure for detecting even very small quantities of species present on surfaces, in particular the surface of metallic alloys. The data could, for example, identify the constituents in passive films that are less than a monolayer in average thickness. Processes such as 60 Co pick-up could be monitored in real time. In fact, if it is known that incorporation of 60 Co occurs when a particular oxide film forms on the surface of the alloy, then measurement of the SER spectra could indicate when such films are beginning to form and thereby provide an early indication that conditions inside the reactor are now suitable for 60 Co pick-up in the passive films

Analysis of Stationary, Photovoltaic-based Surface Power System Designs at the Lunar South Pole

Science.gov (United States)

Freeh, Joshua E.

2009-01-01

Combinations of solar arrays and either batteries or regenerative fuel cells are analyzed for a surface power system module at the lunar south pole. The systems are required to produce 5 kW of net electrical power in sunlight and 2 kW of net electrical power during lunar night periods for a 10-year period between 2020 and 2030. Systems-level models for energy conservation, performance, degradation, and mass are used to compare to various systems. The sensitivities of important and/or uncertain variables including battery specific energy, fuel cell operating voltage, and DC-DC converter efficiency are compared to better understand the system. Switching unit efficiency, battery specific energy, and fuel cell operating voltage appear to be important system-level variables for this system. With reasonably sized solar arrays, the regenerative fuel cell system has significantly lower mass than the battery system based on the requirements and assumptions made herein. The total operational time is estimated at about 10,000 hours in battery discharge/fuel cell mode and about 4,000 and 8,000 hours for the battery charge and electrolyzer modes, respectively. The estimated number of significant depth-of-discharge cycles for either energy storage system is less than 100 for the 10-year period.

Effect of Laser Power on Metallurgical, Mechanical and Tribological Characteristics of Hardfaced Surfaces of Nickel-Based Alloy

Science.gov (United States)

Gnanasekaran, S.; Padmanaban, G.; Balasubramanian, V.

2017-12-01

In this present work, nickel based alloy was deposited on 316 LN austenitic stainless steel (ASS) by a laser hardfacing technique to investigate the influence of laser power on macrostructure, microstructure, microhardness, dilution and wear characteristics. The laser power varied from 1.1 to 1.9 kW. The phase constitution, microstructure and microhardness were examined by optical microscope, scanning electron microscopy, energy dispersion spectroscopy and Vickers microhardness tester. The wear characteristics of the hardfaced surfaces and substrate were evaluated at room temperature (RT) under dry sliding wear condition (pin-on-disc). The outcome demonstrates that as the laser power increases, dilution increases and hardness of the deposit decreases. This is because excess heat melts more volume of substrate material and increases the dilution; subsequently it decreases the hardness of the deposit. The microstructure of the deposit is characterized by Ni-rich carbide, boride and silicide.

Tasks in development of the USSR coal industry

Energy Technology Data Exchange (ETDEWEB)

Bratchenko, B F

1981-08-01

Minister of the Soviet coal industry evaluates social and economic development plan of the Soviet coal industry from 1981 to 1985. Planned coal production should increase to 770-800 Mt, exceeding coal production in 1980 by 53 to 83 Mt. Proportion of coal mined by surface methods will further increase. Investment program concentrates on: construction of the Kansk-Achinsk fuel and energy basin, construction of the South Yakut coal basin and further development of surface mines in the Ehkibastuz basin. Proportion of coal mined in the Kuzbass will increase to 45% of the total coal output. Construction of the Kansk-Achinsk basin has the highest priority among the investment projects. Investment projects (construction of new coal mines and modernization of existing mines) in major coal basins in 1981 are analyzed. Mining machines and equipment for underground and surface black and brown coal mining are evaluated. Plans for developing new mining systems are described (e.g. narrow web coal cutter with chainless haulage system for thin and medium coal seams with drive system with power ranging from 110 to 315 kW). The following types of machines are discussed: coal cutters, shearer loaders, heading machines, belt conveyors, loaders. Selected social problems associated with manpower shortages for underground mining and for coal mines operating under extreme climatic conditions are also discussed.

Properties of surface layer of X40CrMoV5-1 in the relation to remelting conditions by the use of a high power diode laser

International Nuclear Information System (INIS)

Dobrzanski, L.A.; Bonek, M.; Klimpel, A.

2003-01-01

Investigations included remelting experiments on the X40CrMoV5-1 hot-work steel with the high power diode laser. Tests have been made using the high power diode laser (HPDL) in the technological process of remelting. The effect of remelting parameters on structure and properties of its surface layer, as well as on remelting geometry and shape. The influence of the technological conditions and their effect on the mechanical properties of the surface layer, and especially its hardness has been tested. Dependence of the microhardness changes, on the degree of the laser beam influence on the treated surface, and mostly on the hardness increase in the remelted layer is presented. The influence of remelting process parameters on the structure of substrate material is presented. Guidelines for remelting of the X40CrMoV5-1 steel surface using the high power diode laser feature the outcome of the investigation aimed at obtaining its optimum mechanical and working properties. (author)

Multi-objective optimization of surface roughness, cutting forces, productivity and Power consumption when turning of Inconel 718

Directory of Open Access Journals (Sweden)

Hamid Tebassi

2016-01-01

Full Text Available Nickel based super alloys are excellent for several applications and mainly in structural components submitted to high temperatures owing to their high strength to weight ratio, good corrosion resistance and metallurgical stability such as in cases of jet engine and gas turbine components. The current work presents the experimental investigations of the cutting parameters effects (cutting speed, depth of cut and feed rate on the surface roughness, cutting force components, productivity and power consumption during dry conditions in straight turning using coated carbide tool. The mathematical models for output parameters have been developed using Box-Behnken design with 15 runs and Box-Cox transformation was used for improving normality. The results of the analysis have shown that the surface finish was statistically sensitive to the feed rate and cutting speed with the contribution of 43.58% and 23.85% respectively, while depth of cut had the greatest effect on the evolution of cutting force components with the contribution of 79.87% for feed force, 66.92% for radial force and 66.26% for tangential force. Multi-objective optimization procedure allowed minimizing roughness Ra, cutting forces and power consumption and maximizing material removal rate using desirability approach.

Test surfaces useful for calibration of surface profilometers

Science.gov (United States)

Yashchuk, Valeriy V; McKinney, Wayne R; Takacs, Peter Z

2013-12-31

The present invention provides for test surfaces and methods for calibration of surface profilometers, including interferometric and atomic force microscopes. Calibration is performed using a specially designed test surface, or the Binary Pseudo-random (BPR) grating (array). Utilizing the BPR grating (array) to measure the power spectral density (PSD) spectrum, the profilometer is calibrated by determining the instrumental modulation transfer.

Discharge Characteristics of Series Surface/Packed-Bed Discharge Reactor Diven by Bipolar Pulsed Power

Science.gov (United States)

Hu, Jian; Jiang, Nan; Li, Jie; Shang, Kefeng; Lu, Na; Wu, Yan; Mizuno, Akira

2016-03-01

The discharge characteristics of the series surface/packed-bed discharge (SSPBD) reactor driven by bipolar pulse power were systemically investigated in this study. In order to evaluate the advantages of the SSPBD reactor, it was compared with traditional surface discharge (SD) reactor and packed-bed discharge (PBD) reactor in terms of the discharge voltage, discharge current, and ozone formation. The SSPBD reactor exhibited a faster rising time and lower tail voltage than the SD and PBD reactors. The distribution of the active species generated in different discharge regions of the SSPBD reactor was analyzed by optical emission spectra and ozone analysis. It was found that the packed-bed discharge region (3.5 mg/L), rather than the surface discharge region (1.3 mg/L) in the SSPBD reactor played a more important role in ozone generation. The optical emission spectroscopy analysis indicated that more intense peaks of the active species (e.g. N2 and OI) in the optical emission spectra were observed in the packed-bed region. supported by National Natural Science Foundation of China (No. 51177007), the Joint Funds of National Natural Science Foundation of China (No. U1462105), and Dalian University of Technology Fundamental Research Fund of China (No. DUT15RC(3)030)

Solid-State Thermionic Nuclear Power for Megawatt Propulsion, Planetary Surface and Commercial Power Project

Data.gov (United States)

National Aeronautics and Space Administration — Thermionic (TI) power conversion is a promising technology first investigated for power conversion in the 1960’s, and of renewed interest due to modern...

Application of powerful quasi-steady-state plasma accelerators for simulation of ITER transient heat loads on divertor surfaces

Energy Technology Data Exchange (ETDEWEB)

Tereshin, V I [Institute of Plasma Physics of the NSC KIPT, Kharkov 61108 (Ukraine); Bandura, A N [Institute of Plasma Physics of the NSC KIPT, Kharkov 61108 (Ukraine); Byrka, O V [Institute of Plasma Physics of the NSC KIPT, Kharkov 61108 (Ukraine); Chebotarev, V V [Institute of Plasma Physics of the NSC KIPT, Kharkov 61108 (Ukraine); Garkusha, I E [Institute of Plasma Physics of the NSC KIPT, Kharkov 61108 (Ukraine); Landman, I [Forschungszentrum Karlsruhe, IHM, Karlsruhe 76021 (Germany); Makhlaj, V A [Institute of Plasma Physics of the NSC KIPT, Kharkov 61108 (Ukraine); Neklyudov, I M [Institute of Plasma Physics of the NSC KIPT, Kharkov 61108 (Ukraine); Solyakov, D G [Institute of Plasma Physics of the NSC KIPT, Kharkov 61108 (Ukraine); Tsarenko, A V [Institute of Plasma Physics of the NSC KIPT, Kharkov 61108 (Ukraine)

2007-05-15

The paper presents the investigations of high power plasma interaction with material surfaces under conditions simulating the ITER disruptions and type I ELMs. Different materials were exposed to plasma with repetitive pulses of 250 {mu}s duration, the ion energy of up to 0.6 keV, and the heat loads varying in the 0.5-25 MJ m{sup -2} range. The plasma energy transfer to the material surface versus impact load has been analysed. The fraction of plasma energy that is absorbed by the target surface is rapidly decreased with the achievement of the evaporation onset for exposed targets. The distributions of evaporated material in front of the target surface and the thickness of the shielding layer are found to be strongly dependent on the target atomic mass. The surface analysis of tungsten targets exposed to quasi-steady-state plasma accelerators plasma streams is presented together with measurements of the melting onset load and evaporation threshold, and also of erosion patterns with increasing heat load and the number of plasma pulses.

Effect of ultrasonic, sonic and rotating-oscillating powered toothbrushing systems on surface roughness and wear of white spot lesions and sound enamel: An in vitro study.

Science.gov (United States)

Hernandé-Gatón, Patrícia; Palma-Dibb, Regina Guenka; Silva, Léa Assed Bezerra da; Faraoni, Juliana Jendiroba; de Queiroz, Alexandra Mussolino; Lucisano, Marília Pacífico; Silva, Raquel Assed Bezerra da; Nelson Filho, Paulo

2018-04-01

To evaluate the effect of ultrasonic, sonic and rotating-oscillating powered toothbrushing systems on surface roughness and wear of white spot lesions and sound enamel. 40 tooth segments obtained from third molar crowns had the enamel surface divided into thirds, one of which was not subjected to toothbrushing. In the other two thirds, sound enamel and enamel with artificially induced white spot lesions were randomly assigned to four groups (n=10) : UT: ultrasonic toothbrush (Emmi-dental); ST1: sonic toothbrush (Colgate ProClinical Omron); ST2: sonic toothbrush (Sonicare Philips); and ROT: rotating-oscillating toothbrush (control) (Oral-B Professional Care Triumph 5000 with SmartGuide). The specimens were analyzed by confocal laser microscopy for surface roughness and wear. Data were analyzed statistically by paired t-tests, Kruskal-Wallis, two-way ANOVA and Tukey's post-test (α= 0.05). The different powered toothbrushing systems did not cause a significant increase in the surface roughness of sound enamel (P> 0.05). In the ROT group, the roughness of white spot lesion surface increased significantly after toothbrushing and differed from the UT group (Pspot lesion compared with sound enamel, and this group differed significantly from the ST1 group (Pspot lesion increased surface roughness and wear. None of the powered toothbrushing systems (ultrasonic, sonic and rotating-oscillating) tested caused significant alterations on sound dental enamel. However, conventional rotating-oscillating toothbrushing on enamel with white spot lesion increased surface roughness and wear. Copyright©American Journal of Dentistry.

Self-Powered Wireless Smart Sensor Node Enabled by an Ultrastable, Highly Efficient, and Superhydrophobic-Surface-Based Triboelectric Nanogenerator.

Science.gov (United States)

Zhao, Kun; Wang, Zhong Lin; Yang, Ya

2016-09-27

Wireless sensor networks will be responsible for a majority of the fast growth in intelligent systems in the next decade. However, most of the wireless smart sensor nodes require an external power source such as a Li-ion battery, where the labor cost and environmental waste issues of replacing batteries have largely limited the practical applications. Instead of using a Li-ion battery, we report an ultrastable, highly efficient, and superhydrophobic-surface-based triboelectric nanogenerator (TENG) to scavenge wind energy for sustainably powering a wireless smart temperature sensor node. There is no decrease in the output voltage and current of the TENG after continuous working for about 14 h at a wind speed of 12 m/s. Through a power management circuit, the TENG can deliver a constant output voltage of 3.3 V and a pulsed output current of about 100 mA to achieve highly efficient energy storage in a capacitor. A wireless smart temperature sensor node can be sustainably powered by the TENG for sending the real-time temperature data to an iPhone under a working distance of 26 m, demonstrating the feasibility of the self-powered wireless smart sensor networks.

Frictional power dissipation on plate boundary faults: Implications for coseismic slip propagation at near-surface depths

Science.gov (United States)

Ikari, M.; Kopf, A.; Saffer, D. M.; Marone, C.; Carpenter, B. M.

2013-12-01

The general lack of earthquake slip at shallow (behavior associated with laboratory observations that disaggregated fault gouges commonly strengthen with increasing sliding velocity (i.e. velocity-strengthening friction), which precludes strain energy release via stress drops. However, the 2011 Tohoku earthquake demonstrated that coseismic rupture and slip can sometimes propagate to the surface in subduction zones. Surface rupture is also known to occur on other plate boundary faults, such as the Alpine Fault in New Zealand. It is uncertain how the extent of coseismic slip propagation from depth is controlled by the frictional properties of the near-surface portion of major faults. In these situations, it is common for slip to localize within gouge having a significant component of clay minerals, which laboratory experiments have shown are generally weak and velocity strengthening. However, low overall fault strength should facilitate coseismic slip, while velocity-strengthening behavior would resist it. In order to investigate how frictional properties may control the extent of coseismic slip propagation at shallow depths, we compare frictional strength and velocity-dependence measurements using samples from three subduction zones known for hosting large magnitude earthquakes. We focus on samples recovered during scientific drilling projects from the Nankai Trough, Japan, the Japan Trench in the region of the Tohoku earthquake, and the Middle America Trench, offshore Costa Rica; however we also include comparisons with other major fault zones sampled by drilling. In order to incorporate the combined effects of overall frictional strength and friction velocity-dependence, we estimate shear strength as a function of slip velocity (at constant effective normal stress), and integrate this function to obtain the areal power density, or frictional power dissipation capability of the fault zone. We also explore the role of absolute shear stress level before arrival of a

Cooptimization of Adhesion and Power Conversion Efficiency of Organic Solar Cells by Controlling Surface Energy of Buffer Layers.

Science.gov (United States)

Lee, Inhwa; Noh, Jonghyeon; Lee, Jung-Yong; Kim, Taek-Soo

2017-10-25

Here, we demonstrate the cooptimization of the interfacial fracture energy and power conversion efficiency (PCE) of poly[N-9'-heptadecanyl-2,7-carbazole-alt-5,5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)] (PCDTBT)-based organic solar cells (OSCs) by surface treatments of the buffer layer. The investigated surface treatments of the buffer layer simultaneously changed the crack path and interfacial fracture energy of OSCs under mechanical stress and the work function of the buffer layer. To investigate the effects of surface treatments, the work of adhesion values were calculated and matched with the experimental results based on the Owens-Wendt model. Subsequently, we fabricated OSCs on surface-treated buffer layers. In particular, ZnO layers treated with poly[(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] (PFN) simultaneously satisfied the high mechanical reliability and PCE of OSCs by achieving high work of adhesion and optimized work function.

Local digital control of power electronic converters in a dc microgrid based on a-priori derivation of switching surfaces

Science.gov (United States)

Banerjee, Bibaswan

In power electronic basedmicrogrids, the computational requirements needed to implement an optimized online control strategy can be prohibitive. The work presented in this dissertation proposes a generalized method of derivation of geometric manifolds in a dc microgrid that is based on the a-priori computation of the optimal reactions and trajectories for classes of events in a dc microgrid. The proposed states are the stored energies in all the energy storage elements of the dc microgrid and power flowing into them. It is anticipated that calculating a large enough set of dissimilar transient scenarios will also span many scenarios not specifically used to develop the surface. These geometric manifolds will then be used as reference surfaces in any type of controller, such as a sliding mode hysteretic controller. The presence of switched power converters in microgrids involve different control actions for different system events. The control of the switch states of the converters is essential for steady state and transient operations. A digital memory look-up based controller that uses a hysteretic sliding mode control strategy is an effective technique to generate the proper switch states for the converters. An example dcmicrogrid with three dc-dc boost converters and resistive loads is considered for this work. The geometric manifolds are successfully generated for transient events, such as step changes in the loads and the sources. The surfaces corresponding to a specific case of step change in the loads are then used as reference surfaces in an EEPROM for experimentally validating the control strategy. The required switch states corresponding to this specific transient scenario are programmed in the EEPROM as a memory table. This controls the switching of the dc-dc boost converters and drives the system states to the reference manifold. In this work, it is shown that this strategy effectively controls the system for a transient condition such as step changes

Selection of power plant elements for future reactor space electric power systems

International Nuclear Information System (INIS)

Buden, D.; Bennett, G.A.; Copper, K.

1979-09-01

Various types of reactor designs, electric power conversion equipment, and reject-heat systems to be used in nuclear reactor power plants for future space missions were studied. The designs included gas-cooled, liquid-cooled, and heat-pipe reactors. For the power converters, passive types such as thermoelectric and thermionic converters and dynamic types such as Brayton, potassium Rankine, and Stirling cycles were considered. For the radiators, heat pipes for transfer and radiating surface, pumped fluid for heat transfer with fins as the radiating surface, and pumped fluid for heat transfer with heat pipes as the radiating surface were considered. After careful consideration of weights, sizes, reliabilities, safety, and development cost and time, a heat-pipe reactor design, thermoelectric converters, and a heat-pipe radiator for an experimental program were selected

Testing of an Annular Linear Induction Pump for the Fission Surface Power Technology Demonstration Unit

Science.gov (United States)

Polzin, K. A.; Pearson, J. B.; Webster, K.; Godfoy, T. J.; Bossard, J. A.

2013-01-01

Results of performance testing of an annular linear induction pump that has been designed for integration into a fission surface power technology demonstration unit are presented. The pump electromagnetically pushes liquid metal (NaK) through a specially-designed apparatus that permits quantification of pump performance over a range of operating conditions. Testing was conducted for frequencies of 40, 55, and 70 Hz, liquid metal temperatures of 125, 325, and 525 C, and input voltages from 30 to 120 V. Pump performance spanned a range of flow rates from roughly 0.3 to 3.1 L/s (4.8 to 49 gpm), and pressure heads of <1 to 104 kPa (<0.15 to 15 psi). The maximum efficiency measured during testing was 5.4%. At the technology demonstration unit operating temperature of 525 C the pump operated over a narrower envelope, with flow rates from 0.3 to 2.75 L/s (4.8 to 43.6 gpm), developed pressure heads from <1 to 55 kPa (<0.15 to 8 psi), and a maximum efficiency of 3.5%. The pump was supplied with three-phase power at 40 and 55 Hz using a variable-frequency motor drive, while power at 55 and 70 Hz was supplied using a variable-frequency power supply. Measured performance of the pump at 55 Hz using either supply exhibited good quantitative agreement. For a given temperature, the peak in efficiency occurred at different flow rates as the frequency was changed, but the maximum value of efficiency was relative insensitive within 0.3% over the frequency range tested, including a scan from 45 to 78 Hz. The objectives of the FSP technology project are as follows:5 • Develop FSP concepts that meet expected surface power requirements at reasonable cost with added benefits over other options. • Establish a nonnuclear hardware-based technical foundation for FSP design concepts to reduce overall development risk. • Reduce the cost uncertainties for FSP and establish greater credibility for flight system cost estimates. • Generate the key nonnuclear products to allow Agency

Inductance and resistance measurement method for vessel detection and coil powering in all-surface inductive heating systems composed of outer squircle coils

Science.gov (United States)

Kilic, Veli Tayfun; Unal, Emre; Demir, Hilmi Volkan

2017-05-01

In this work, we investigate a method proposed for vessel detection and coil powering in an all-surface inductive heating system composed of outer squircle coils. Besides conventional circular coils, coils with different shapes such as outer squircle coils are used for and enable efficient all-surface inductive heating. Validity of the method, which relies on measuring inductance and resistance values of a loaded coil at different frequencies, is experimentally demonstrated for a coil with shape different from conventional circular coil. Simple setup was constructed with a small coil to model an all-surface inductive heating system. Inductance and resistance maps were generated by measuring coil's inductance and resistance values at different frequencies loaded by a plate made of different materials and located at various positions. Results show that in an induction hob for various coil geometries it is possible to detect a vessel's presence, to identify its material type and to specify its position on the hob surface by considering inductance and resistance of the coil measured on at least two different frequencies. The studied method is important in terms of enabling safe, efficient and user flexible heating in an all-surface inductive heating system by automatically detecting the vessel's presence and powering on only the coils that are loaded by the vessel with predetermined current levels.

Power electronics substrate for direct substrate cooling

Science.gov (United States)

Le, Khiet [Mission Viejo, CA; Ward, Terence G [Redondo Beach, CA; Mann, Brooks S [Redondo Beach, CA; Yankoski, Edward P [Corona, CA; Smith, Gregory S [Woodland Hills, CA

2012-05-01

Systems and apparatus are provided for power electronics substrates adapted for direct substrate cooling. A power electronics substrate comprises a first surface configured to have electrical circuitry disposed thereon, a second surface, and a plurality of physical features on the second surface. The physical features are configured to promote a turbulent boundary layer in a coolant impinged upon the second surface.

Unmanned Surface Sea Vehicle Power System Design and Modeling

National Research Council Canada - National Science Library

Pritpal, Singh

2005-01-01

.... The power system of the USV is chosen to be a hybrid power source comprising a diesel generator and a lithium-ion battery pack Optimal sizing of the diesel generator and battery pack is important...

Archveyor{trademark} automated mining system - implementation at the Conant mine

Energy Technology Data Exchange (ETDEWEB)

Hofmann, W.J. [Arch of Illinois, Percy, IL (United States)

1997-12-01

Arch Mineral Corporation, through the Arch Technology Department, has developed an automated continuous haulage mining system called the `Archveyor{trademark}`. The original technology came from a Russian patent. Kloeckner-Becorit (K-B) further developed the system and called it the `Mobile Conveyor`. This system was utilized in both coal and trona mines in the United States and Canada. Consolidation Coal designed their version of this continuous haulage system, called the `Tramveyor`. The Tramveyor is presently operating in their Dilworth Mine, in Pennsylvania. This system has no computer guidance system related to the continuous miner or the Tramveyor. Arch Mineral Corporation has further developed this continuous haulage mining system. Their system is a programmable, logic-controlled (PLC) automated mining system. A highwall version of the Archveyor{trademark} is being operated at Arch of Wyoming near Hanna, Wyoming. This paper introduces the first underground version of Archveyor{trademark} to be implemented at Conant Mine in southern Illinois. During the development process, the Archveyor{trademark} mining system consists of a continuous miner, a bolter car, the Archveyor{trademark} (itself), a stageloader, and an operator`s cab. During the secondary mining process the bolter car is taken out of the system.

O Electromagnetic Power Waves and Power Density Components.

Science.gov (United States)

Petzold, Donald Wayne

1980-12-01

On January 10, 1884 Lord Rayleigh presented a paper entitled "On the Transfer of Energy in the Electromagnetic Field" to the Royal Society of London. This paper had been authored by the late Fellow of Trinity College, Cambridge, Professor J. H. Poynting and in it he claimed that there was a general law for the transfer of electromagnetic energy. He argued that associated with each point in space is a quantity, that has since been called the Poynting vector, that is a measure of the rate of energy flow per unit area. His analysis was concerned with the integration of this power density vector at all points over an enclosing surface of a specific volume. The interpretation of this Poynting vector as a true measure of the local power density was viewed with great skepticism unless the vector was integrated over a closed surface, as the development of the concept required. However, within the last decade or so Shadowitz indicates that a number of prominent authors have argued that the criticism of the interpretation of Poynting's vector as a local power density vector is unjustified. The present paper is not concerned with these arguments but instead is concerned with a decomposition of Poynting's power density vector into two and only two components: one vector which has the same direction as Poynting's vector and which is called the forward power density vector, and another vector, directed opposite to the Poynting vector and called the reverse power density vector. These new local forward and reverse power density vectors will be shown to be dependent upon forward and reverse power wave vectors and these vectors in turn will be related to newly defined forward and reverse components of the electric and magnetic fields. The sum of these forward and reverse power density vectors, which is simply the original Poynting vector, is associated with the total electromagnetic energy traveling past the local point. Another vector which is the difference between the forward

Foulant characteristics comparison in recycling cooling water system makeup by municipal reclaimed water and surface water in power plant.

Science.gov (United States)

Ping, Xu; Jing, Wang; Yajun, Zhang; Jie, Wang; Shuai, Si

2015-01-01

Due to water shortage, municipal reclaimed water rather than surface water was replenished into recycling cooling water system in power plants in some cities in China. In order to understand the effects of the measure on carbon steel corrosion, characteristics of two kinds of foulant produced in different systems were studied in the paper. Differences between municipal reclaimed water and surface water were analyzed firstly. Then, the weight and the morphology of two kinds of foulant were compared. Moreover, other characteristics including the total number of bacteria, sulfate reducing bacteria, iron bacteria, extracellular polymeric substance (EPS), protein (PN), and polysaccharide (PS) in foulant were analyzed. Based on results, it could be concluded that microbial and corrosive risk would be increased when the system replenished by municipal reclaimed water instead of surface water.

A Pulse Power Modulator System for Commercial High Power Ion Beam Surface Treatment Applications

International Nuclear Information System (INIS)

Barrett, D.M.; Cockreham, B.D.; Dragt, A.J.; Ives, H.C.; Neau, E.L.; Reed, K.W.; White, F.E.

1999-01-01

The Ion Beam Surface Treatment (lBESTrM) process utilizes high energy pulsed ion beams to deposit energy onto the surface of a material allowing near instantaneous melting of the surface layer. The melted layer typically re-solidifies at a very rapid rate which forms a homogeneous, fine- grained structure on the surface of the material resulting in significantly improved surface characteristics. In order to commercialize the IBESTTM process, a reliable and easy-to-operate modulator system has been developed. The QM-I modulator is a thyratron-switched five-stage magnetic pulse compression network which drives a two-stage linear induction adder. The adder provides 400 kV, 150 ns FWHM pulses at a maximum repetition rate of 10 pps for the acceleration of the ion beam. Special emphasis has been placed upon developing the modulator system to be consistent with long-life commercial service

Mining within the energy economy of the Federal Republic in 1975. Der Kohlenbergbau in der Energiewirtschaft der Bundesrepublik im Jahre 1975

Energy Technology Data Exchange (ETDEWEB)

1976-10-01

Seven chapters present a survey of German mining in 1975. Special emphasis is put on its position within the energy economy of the FRG. 115 tables deal with: the economic and personnel development, haulage and sales of coal, coke and briquets (balance of coal), energy consumption in the FRG, stockpiling of the economy with coal and coke and stocks in coal, coke and briquets, foreign energy trade and energy balances (primary energy generation and consumption). The annex presents figures on pit coal/brown coal haulage, coke production, petroleum and natural gas production, electricity generation and crude steel production, arranged according to countries. The data refers mainly to the period 1964 - 1975.

Possibilities of increasing the efficiency of track-bound haulage in roadways, particularly diesel locomotive haulage

Energy Technology Data Exchange (ETDEWEB)

Arnold, H; Zubiller, H

1977-12-15

This paper discusses ways of increasing the efficiency of monorail transport systems by changes in the design of trains and tracks. It is important that the slope of roadways should be as even as possible, thus avoiding steep sections. The tracks should be kept clean, and critical parts should be covered to protect them from dirt. (In German)

Enhancement of light output power of GaN-based light-emitting diodes with photonic quasi-crystal patterned on p-GaN surface and n-side sidewall roughing

Science.gov (United States)

2013-01-01

In this paper, GaN-based light-emitting diodes (LEDs) with photonic quasi-crystal (PQC) structure on p-GaN surface and n-side roughing by nano-imprint lithography are fabricated and investigated. At an injection current of 20 mA, the LED with PQC structure on p-GaN surface and n-side roughing increased the light output power of the InGaN/GaN multiple quantum well LEDs by a factor of 1.42, and the wall-plug efficiency is 26% higher than the conventional GaN-based LED type. After 500-h life test (55°C/50 mA), it was found that the normalized output power of GaN-based LED with PQC structure on p-GaN surface and n-side roughing only decreased by 6%. These results offer promising potential to enhance the light output powers of commercial light-emitting devices using the technique of nano-imprint lithography. PMID:23683526

Estimation of mean time to failure of a near surface radioactive waste repository for PWR power stations

International Nuclear Information System (INIS)

Aguiar, Lais A. de; Frutuoso e Melo, P.F.; Alvim, Antonio C.M.

2007-01-01

This work aims at estimating the mean time to failure (MTTF) of each barrier of a near surface radioactive waste repository. It is assumed that surface water infiltrates through the barriers, reaching the matrix where radionuclides are contained, releasing them to the environment. Radioactive wastes considered in this work are low and medium level wastes (produced during operation of a PWR nuclear power station) fixed on cement. The repository consists of 6 saturated porous media barriers (top cover, upper layer, packages, basis, repository walls and geosphere). It has been verified that the mean time to failure (MTTF) of each barrier increases for radionuclides having higher retardation factor (Fr) and also that the MTTF for concrete is larger for Nickel , while for the geosphere, Plutonium gives the largest MTTF. (author)

Distribution of a pelagic tunicate, Salpa fusiformis in warm surface current of the eastern Korean waters and its impingement on cooling water intakes of Uljin nuclear power plant.

Science.gov (United States)

Chae, Jinho; Choi, Hyun Woo; Lee, Woo Jin; Kim, Dongsung; Lee, Jae Hac

2008-07-01

Impingement of a large amount of gelatinous plankton, Salpa fusiformis on the seawater intake system-screens in a nuclear power plant at Uljin was firstly recorded on 18th June 2003. Whole amount of the clogged animals was estimated were presumptively at 295 tons and the shortage of cooling seawater supply by the animal clogging caused 38% of decrease in generation capability of the power plant. Zooplankton collection with a multiple towing net during the day and at night from 5 to 6 June 2003 included various gelatinous zooplanktons known to be warm water species such as salps and siphonophores. Comparatively larger species, Salpa fusiformis occupied 25.4% in individual density among the gelatinous plankton and showed surface distribution in the depth shallower than thermocline, performing little diel vertical migration. Temperature, salinity and satellite data also showed warm surface current predominated over the southern coastal region near the power plant in June. The results suggested that warm surface current occasionally extended into the neritic region may transfer S. fusiformis, to the waters off the power plant. The environmental factors and their relation to ecobiology of the large quantity of salpa population that are being sucked into the intake channel of the power plant are discussed.

Influence of a-Si:H deposition power on surface passivation property and thermal stability of a-Si:H/SiNx:H stacks

Directory of Open Access Journals (Sweden)

Hua Li

2012-06-01

Full Text Available The effectiveness of hydrogenated amorphous silicon (a-Si:H layers for passivating crystalline silicon surfaces has been well documented in the literature for well over a decade. One limitation of such layers however has arisen from their inability to withstand temperatures much above their deposition temperature without significant degradation. This limitation is of importance particularly with multicrystalline silicon materials where temperatures of at least 400°C are needed for effective hydrogenation of the crystallographic defects such as grain boundaries. To address this limitation, in this work the surface passivation quality and thermal stability of a stack passivating system, combining a layer of intrinsic a-Si:H and a capping layer of silicon nitride (SiNx:H, on p-type crystalline silicon wafers is studied and optimized. In particular the sensitivity of different microwave (MW power levels for underlying a-Si:H layer deposition are examined. Both effective minority carrier lifetime (ζeff measurement and Fourier transform infrared (FTIR spectrometry were employed to study the bonding configurations, passivating quality and thermal stability of the a-Si:H/SiNx:H stacks. It is established that the higher MW power could result in increased as-deposited ζeff and implied Voc (iVoc values, indicating likely improved surface passivation quality, but that this combination degrades more quickly when exposed to prolonged thermal treatments. The more dihydride-rich film composition corresponding to the higher MW power appears to be beneficial for bond restructuring by hydrogen interchanges when exposed to short term annealing, however it also appears more susceptible to providing channels for hydrogen out-effusion which is the likely cause of the poorer thermal stability for prolonged high temperature exposure compared with stacks with underlying a-Si:H deposited with lower MW power.

Underground coal mining - methods, equipment developments and trends

Energy Technology Data Exchange (ETDEWEB)

Singhal, R

1988-12-01

Underground mines are truly beginning to accept the so-called 'high tech' technology evident in other industries. Automation, remote control and robotics have taken an added significance. Wireless communication, mine-wide equipment health and performance monitoring, and transmission of data from deeper levels to surface is moving towards becoming the norm. There is emphasis on developing and applying continuous mining systems, as well as on modifying cyclical discontinuous methods to continuous systems. Multi-purpose equipment is also being developed. Technology transfer is playing its role - equipment and systems from surface coal mining are being applied to underground mining and vice-versa. At the American Mining Congress Exhibition held in Chicago in April 1988, a variety of equipment for underground mining was displayed including coal face equipment such as shearer loaders, conveyors and powered supports, and equipment for room-and-pillar coal mining. The trend continues to be towards high power machines equipped with a variety of electronics and sensors, safety devices, and alarm systems. Ancillary equipment on display covered a variety of cutting drums, cutting tools, conveying equipment and so on. In room-and-pillar mining, the overall emphasis was on moving away from the cyclical nature of the work. Transportation by shuttle cars must be replaced by continuous transport systems such as conveyors. Experience from Australia has shown that the application of continuous haulage and breaker line supports has permitted a doubling of production from room-and-pillar systems. Production levels of 3,000tpd have already been achieved, and 4,000tpd is considered achievable.

A Comparison of Fission Power System Options for Lunar and Mars Surface Applications

International Nuclear Information System (INIS)

Mason, Lee S.

2006-01-01

This paper presents a comparison of reactor and power conversion design options for 50 kWe class lunar and Mars surface power applications with scaling from 25 to 200 kWe. Design concepts and integration approaches are provided for three reactor-converter combinations: gas-cooled Brayton, liquid-metal Stirling, and liquid-metal thermoelectric. The study examines the mass and performance of low temperature, stainless steel based reactors and higher temperature refractory reactors. The preferred system implementation approach uses crew-assisted assembly and in-situ radiation shielding via installation of the reactor in an excavated hole. As an alternative, self-deployable system concepts that use earth-delivered, on-board radiation shielding are evaluated. The analyses indicate that among the 50 kWe stainless steel reactor options, the liquid-metal Stirling system provides the lowest mass at about 5300 kg followed by the gas-cooled Brayton at 5700 kg and the liquid-metal thermoelectric at 8400 kg. The use of a higher temperature, refractory reactor favors the gas-cooled Brayton option with a system mass of about 4200 kg as compared to the Stirling and thermoelectric options at 4700 kg and 5600 kg, respectively. The self-deployed concepts with on-board shielding result in a factor of two system mass increase as compared to the in-situ shielded concepts

DOWNHOLE POWER GENERATION AND WIRELESS COMMUNICATIONS FOR INTELLIGENT COMPLETIONS APPLICATIONS

Energy Technology Data Exchange (ETDEWEB)

Paul Tubel

2004-02-01

The development work during this quarter was focused in the assembly of the downhole power generator hardware and its electronics module. The quarter was also spent in the development of the surface system electronics and software to extract the acoustic data transmitted from downhole to the surface from the noise generated by hydrocarbon flow in wells and to amplify very small acoustic signals to increase the distance between the downhole tool and the surface receiver. The tasks accomplished during this report period were: (1) Assembly of the downhole power generator mandrel for generation of electrical power due to flow in the wellbore. (2) Test the piezoelectric wafers to assure that they are performing properly prior to integrating them to the mechanical power generator mandrel. (3) Coat the power generator wafers to prevent water from shorting the power generator wafers. (4) Test of the power generator using a water tower and an electric pump to create a water flow loop. (5) Test the power harvesting electronics module. (6) Upgrade the signal condition and amplification from downhole into the surface system. (7) Upgrade the surface processing system capability to process data faster. (8) Create a new filtering technique to extract the signal from noise after the data from downhole is received at the surface system.

Nuclear power systems for Lunar and Mars exploration

International Nuclear Information System (INIS)

Sovie, R.J.; Bozek, J.M.

1994-01-01

Initial studies of a variety of mission scenarios for the new Space Exploration Initiative, and the technologies necessary to enable or significantly enhance them, have identified the development of advanced space power systems - whether solar, chemical or nuclear - to be of prime importance. Lightweight, compact, reliable power systems for planetary rovers and a variety of surface vehicles, utility surface power, and power for advanced propulsion systems were identified as critical needs for these missions. This paper discusses these mission scenarios, the concomitant power system requirements; the power system options considered and identifies the significant potential benefits of nuclear power for meeting the power needs of the above applications

Power from Ocean Waves.

Science.gov (United States)

Newman, J. N.

1979-01-01

Discussed is the utilization of surface ocean waves as a potential source of power. Simple and large-scale wave power devices and conversion systems are described. Alternative utilizations, environmental impacts, and future prospects of this alternative energy source are detailed. (BT)

High Temperature Surface Parameters for Solar Power

National Research Council Canada - National Science Library

Butler, C. F; Jenkins, R. J; Rudkin, R. L; Laughridge, F. I

1960-01-01

... at a given distance from the sun. Thermal conversion efficiencies with a concentration ratio of 50 have been computed for each surface when exposed to solar radiation at the Earth's mean orbital radius...

Intermodal Freight Transport on the Right Track? Environmental and economic performances and their trade-off

International Nuclear Information System (INIS)

Kim, Nam Seok

2010-01-01

This dissertation aims to evaluate environmental and economic performances of an intermodal freight transport system and to estimate the trade-off between CO2 emissions, which is presented as an indicator of environmental performance, and freight costs, which indicate the economic performance of the intermodal freight system. The truck-only system is always regarded as the counterpart of the intermodal freight system in this dissertation. To examine the environmental performance of the intermodal freight system, CO2 emissions generated from all the processes in the intermodal chain, such as pre-haulage and post-haulage, long distance haulage, and transshipment, are estimated considering different sources that generate electricity and transmission loss of electricity (Chapters 3 and 4). To examine the economic performance of the system, two approaches are considered: (1) finding the intermodal breakeven distance for which the intermodal system is more competitive than the truck-only system (Chapter 5); (2) examining the economies of scale in the intermodal network and finding the route/system choice that minimizes the total freight transportation costs (Chapter 6). Finally, this dissertation attempts to find the trade-off between CO2 emissions (representing the environmental performance) and freight transportation cost (representing the economic performance) (Chapter 7)

Electrical power systems for Mars

Science.gov (United States)

Giudici, Robert J.

1986-01-01

Electrical power system options for Mars Manned Modules and Mars Surface Bases were evaluated for both near-term and advanced performance potential. The power system options investigated for the Mission Modules include photovoltaics, solar thermal, nuclear reactor, and isotope power systems. Options discussed for Mars Bases include the above options with the addition of a brief discussion of open loop energy conversion of Mars resources, including utilization of wind, subsurface thermal gradients, and super oxides. Electrical power requirements for Mission Modules were estimated for three basic approaches: as a function of crew size; as a function of electric propulsion; and as a function of transmission of power from an orbiter to the surface of Mars via laser or radio frequency. Mars Base power requirements were assumed to be determined by production facilities that make resources available for follow-on missions leading to the establishment of a permanently manned Base. Requirements include the production of buffer gas and propellant production plants.

Flow and Displacement of Non-Newtonian Fluid(Power-Law Model) by Surface Tension and Gravity Force in Inclined Circular Tube

International Nuclear Information System (INIS)

Moh, Jeong Hah; Cho, Y. I.

2014-01-01

This paper presents the theoretical analysis of a flow driven by surface tension and gravity in an inclined circular tube. A governing equation is developed for describing the displacement of a non-Newtonian fluid(Power-law model) that continuously flows into a circular tube owing to surface tension, which represents a second-order, nonlinear, non-homogeneous, and ordinary differential form. It was found that quantitatively, the theoretical predictions of the governing equation were in excellent agreement with the solutions of the equation for horizontal tubes and the past experimental data. In addition, the predictions compared very well with the results of the force balance equation for steady

Space structures, power, and power conditioning; Proceedings of the Meeting, Los Angeles, CA, Jan. 11-13, 1988

International Nuclear Information System (INIS)

Askew, R.F.

1988-01-01

Various papers on space structures, power, and power conditioning are presented. Among the topics discussed are: heterogeneous gas core reaction for space nuclear power, pulsed gas core reactor for burst power, fundamental considerations of gas core reactor systems, oscillating thermionic conversion for high-density space power, thermoelectromagnetic pumps for space nuclear power systems, lightweight electrochemical converter for space power applications, ballistic acceleration by superheated hydrogen, laser-induced current switching in gaseous discharge, electron-beam-controlled semiconductor switches, laser-controlled semiconductor closing and opening switch. Also addressed are: semiconductor-metal eutectic composites for high-power switching, optical probes for the characterization of surface breakdown, 40 kV/20 kA pseudospark switch for laser applications, insulation direction for high-power space systems, state space simulation of spacecraft power systems, structural vibration of space power station systems, minimum-time control of large space structures, novel fusion reaction for space power and propulsion, repetition rate system evaluations, cryogenic silicon photoconductive switches for high-power lasers, multilevel diamondlike carbon capacitor structure, surface breakdown of prestressed insulators, C-Mo and C-Zr alloys for space power systems, magnetic insulation for the space environment

A highly selective and self-powered gas sensor via organic surface functionalization of p-Si/n-ZnO diodes.

Science.gov (United States)

Hoffmann, Martin W G; Mayrhofer, Leonhard; Casals, Olga; Caccamo, Lorenzo; Hernandez-Ramirez, Francisco; Lilienkamp, Gerhard; Daum, Winfried; Moseler, Michael; Waag, Andreas; Shen, Hao; Prades, J Daniel

2014-12-17

Selectivity and low power consumption are major challenges in the development of sophisticated gas sensor devices. A sensor system is presented that unifies selective sensor-gas interactions and energy-harvesting properties, using defined organic-inorganic hybrid materials. Simulations of chemical-binding interactions and the consequent electronic surface modulation give more insight into the complex sensing mechanism of selective gas detection. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Measurement of Iodine-129 in surface soil collected near the Fukushima Daiichi nuclear power plant accident site

International Nuclear Information System (INIS)

Miyake, Yasuto; Matsuzaki, Hiroyuki; Fujiwara, Takeshi; Saito, Takumi; Yamagata, Takeyasu; Honda, Maki

2013-01-01

Iodine-129 in soil around Fukushima Daiichi nuclear power plant were measured by Accelerator Mass Spectrometry and isotopic ratio of radioiodine was estimated. Surface deposition amount of Iodine-129 resulted in 6.7 to 5500 mBq/m"2. The mean isotopic ratio between Iodine-129 and Iodine-131 at the accident was estimated that "1"2"9"I"/"1"3"1I = 26±6 as of March 11 2011. This result was compared to the calculation result of ORIGEN2 code to test the validity of this estimation. (author)

Sound radiation from finite surfaces

DEFF Research Database (Denmark)

Brunskog, Jonas

2013-01-01

A method to account for the effect of finite size in acoustic power radiation problem of planar surfaces using spatial windowing is developed. Cremer and Heckl presents a very useful formula for the power radiating from a structure using the spatially Fourier transformed velocity, which combined...... with spatially windowing of a plane waves can be used to take into account the finite size. In the present paper, this is developed by means of a radiation impedance for finite surfaces, that is used instead of the radiation impedance for infinite surfaces. In this way, the spatial windowing is included...

Wetland Water Cooling Partnership: The Use of Constructed Wetlands to Enhance Thermoelectric Power Plant Cooling and Mitigate the Demand of Surface Water Use

Energy Technology Data Exchange (ETDEWEB)

Apfelbaum, Steven L. [Applied Ecological Services Inc., Brodhead, WI (United States); Duvall, Kenneth W. [Sterling Energy Services, LLC, Atlanta, GA (United States); Nelson, Theresa M. [Applied Ecological Services Inc., Brodhead, WI (United States); Mensing, Douglas M. [Applied Ecological Services Inc., Brodhead, WI (United States); Bengtson, Harlan H. [Sterling Energy Services, LLC, Atlanta, GA (United States); Eppich, John [Waterflow Consultants, Champaign, IL (United States); Penhallegon, Clayton [Sterling Energy Services, LLC, Atlanta, GA (United States); Thompson, Ry L. [Applied Ecological Services Inc., Brodhead, WI (United States)

2013-12-01

Through the Phase I study segment of contract #DE-NT0006644 with the U.S. Department of Energy’s National Energy Technology Laboratory, Applied Ecological Services, Inc. and Sterling Energy Services, LLC (the AES/SES Team) explored the use of constructed wetlands to help address stresses on surface water and groundwater resources from thermoelectric power plant cooling and makeup water requirements. The project objectives were crafted to explore and develop implementable water conservation and cooling strategies using constructed wetlands (not existing, naturally occurring wetlands), with the goal of determining if this strategy has the potential to reduce surface water and groundwater withdrawals of thermoelectric power plants throughout the country. Our team’s exploratory work has documented what appears to be a significant and practical potential for augmenting power plant cooling water resources for makeup supply at many, but not all, thermoelectric power plant sites. The intent is to help alleviate stress on existing surface water and groundwater resources through harvesting, storing, polishing and beneficially re-using critical water resources. Through literature review, development of conceptual created wetland plans, and STELLA-based modeling, the AES/SES team has developed heat and water balances for conventional thermoelectric power plants to evaluate wetland size requirements, water use, and comparative cooling technology costs. The ecological literature on organism tolerances to heated waters was used to understand the range of ecological outcomes achievable in created wetlands. This study suggests that wetlands and water harvesting can provide a practical and cost-effective strategy to augment cooling waters for thermoelectric power plants in many geographic settings of the United States, particularly east of the 100th meridian, and in coastal and riverine locations. The study concluded that constructed wetlands can have significant positive

The suppression effect of a periodic surface with semicircular grooves on the high power microwave long pill-box window multipactor phenomenon

International Nuclear Information System (INIS)

Zhang, Xue; Wang, Yong; Fan, Junjie; Zhong, Yong; Zhang, Rui

2014-01-01

To improve the transmitting power in an S-band klystron, a long pill-box window that has a disk with grooves with a semicircular cross section is theoretically investigated and simulated. A Monte-Carlo algorithm is used to track the secondary electron trajectories and analyze the multipactor scenario in the long pill-box window and on the grooved surface. Extending the height of the long-box window can decrease the normal electric field on the surface of the window disk, but the single surface multipactor still exists. It is confirmed that the window disk with periodic semicircular grooves can explicitly suppress the multipactor and predominantly depresses the local field enhancement and the bottom continuous multipactor. The difference between semicircular and sharp boundary grooves is clarified numerically and analytically

The suppression effect of a periodic surface with semicircular grooves on the high power microwave long pill-box window multipactor phenomenon

Science.gov (United States)

Zhang, Xue; Wang, Yong; Fan, Junjie; Zhong, Yong; Zhang, Rui

2014-09-01

To improve the transmitting power in an S-band klystron, a long pill-box window that has a disk with grooves with a semicircular cross section is theoretically investigated and simulated. A Monte-Carlo algorithm is used to track the secondary electron trajectories and analyze the multipactor scenario in the long pill-box window and on the grooved surface. Extending the height of the long-box window can decrease the normal electric field on the surface of the window disk, but the single surface multipactor still exists. It is confirmed that the window disk with periodic semicircular grooves can explicitly suppress the multipactor and predominantly depresses the local field enhancement and the bottom continuous multipactor. The difference between semicircular and sharp boundary grooves is clarified numerically and analytically.

The suppression effect of a periodic surface with semicircular grooves on the high power microwave long pill-box window multipactor phenomenon

Energy Technology Data Exchange (ETDEWEB)

Zhang, Xue, E-mail: zhangxue.iecas@yahoo.com; Wang, Yong; Fan, Junjie; Zhong, Yong; Zhang, Rui [Institute of Electronics, Chinese Academy of Sciences, Peking, 100190 China (China)

2014-09-15

To improve the transmitting power in an S-band klystron, a long pill-box window that has a disk with grooves with a semicircular cross section is theoretically investigated and simulated. A Monte-Carlo algorithm is used to track the secondary electron trajectories and analyze the multipactor scenario in the long pill-box window and on the grooved surface. Extending the height of the long-box window can decrease the normal electric field on the surface of the window disk, but the single surface multipactor still exists. It is confirmed that the window disk with periodic semicircular grooves can explicitly suppress the multipactor and predominantly depresses the local field enhancement and the bottom continuous multipactor. The difference between semicircular and sharp boundary grooves is clarified numerically and analytically.

Complete Surface Mapping of ICF Shells

International Nuclear Information System (INIS)

Stephens, R.B.; Olson, D.; Huang, H.; Gibson, J.B.

2004-01-01

Inertial confinement fusion shells have previously been evaluated on the basis of microscopic examination for local defects and limited surface profiling to represent their average fluctuation power. Since defects are local, and don't always have visible edges, this approach both misses some important fluctuations and doesn't properly represent the spatially dependent surface fluctuation power. We have taken the first step toward correcting this problem by demonstrating the capability to completely map the surface of a NIF shell with the resolution to account for all modes. This allows complete accounting of all the surface fluctuations. In the future this capability could be used for valuable shells to generate a complete r(θ, φ) surface map for accurate 3-D modeling of a shot

COMPLETE SURFACE MAPPING OF ICF SHELLS

International Nuclear Information System (INIS)

STEPHENS, R.B.; OLSON, D.; HUANG, H.; GIBSON, J.B.

2003-09-01

OAK-B135 Inertial confinement fusion shells have previously been evaluated on the basis of microscopic examination for local defects and limited surface profiling to represent their average fluctuation power. Since defects are local, and don't always have visible edges, this approach both misses some important fluctuations and doesn't properly represent the spatially dependent surface fluctuation power. they have taken the first step toward correcting this problem by demonstrating the capability to completely map the surface of a NIF shell with the resolution to account for all modes. This allows complete accounting of all the surface fluctuations. In the future this capability could be used for valuable shells to generate a complete r(θ,ψ) surface map for accurate 3-D modeling of a shot

Substantial difference in target surface chemistry between reactive dc and high power impulse magnetron sputtering

Science.gov (United States)

Greczynski, G.; Mráz, S.; Schneider, J. M.; Hultman, L.

2018-02-01

The nitride layer formed in the target race track during the deposition of stoichiometric TiN thin films is a factor 2.5 thicker for high power impulse magnetron sputtering (HIPIMS), compared to conventional dc processing (DCMS). The phenomenon is explained using x-ray photoelectron spectroscopy analysis of the as-operated Ti target surface chemistry supported by sputter depth profiles, dynamic Monte Carlo simulations employing the TRIDYN code, and plasma chemical investigations by ion mass spectrometry. The target chemistry and the thickness of the nitride layer are found to be determined by the implantation of nitrogen ions, predominantly N+ and N2+ for HIPIMS and DCMS, respectively. Knowledge of this method-inherent difference enables robust processing of high quality functional coatings.

Microwave power coupling in a surface wave excited plasma

Directory of Open Access Journals (Sweden)

Satyananda Kar

2015-01-01

Full Text Available In recent decades, different types of plasma sources have been used for various types of plasma processing, such as, etching and thin film deposition. The critical parameter for effective plasma processing is high plasma density. One type of high density plasma source is Microwave sheath-Voltage combination Plasma (MVP. In the present investigation, a better design of MVP source is reported, in which over-dense plasma is generated for low input microwave powers. The results indicate that the length of plasma column increases significantly with increase in input microwave power.

Radioactive surface contamination monitors

International Nuclear Information System (INIS)

Aoyama, Kei; Minagoshi, Atsushi; Hasegawa, Toru

1994-01-01

To reduce radiation exposure and prevent contamination from spreading, each nuclear power plant has established a radiation controlled area. People and articles out of the controlled area are checked for the surface contamination of radioactive materials with surface contamination monitors. Fuji Electric has repeatedly improved these monitors on the basis of user's needs. This paper outlines typical of a surface contamination monitor, a personal surface contamination monitor, an article surface contamination monitor and a laundry monitor, and the whole-body counter of an internal contamination monitor. (author)

Planetary Surface Power and Interstellar Propulsion Using Fission Fragment Magnetic Collimator Reactor

International Nuclear Information System (INIS)

Tsvetkov, Pavel V.; Hart, Ron R.; King, Don B.; Rochau, Gary E.

2006-01-01

Fission energy can be used directly if the kinetic energy of fission fragments is converted to electricity and/or thrust before turning into heat. The completed US DOE NERI Direct Energy Conversion (DEC) Power Production project indicates that viable DEC systems are possible. The US DOE NERI DEC Proof of Principle project began in October of 2002 with the goal to demonstrate performance principles of DEC systems. One of the emerging DEC concepts is represented by fission fragment magnetic collimator reactors (FFMCR). Safety, simplicity, and high conversion efficiency are the unique advantages offered by these systems. In the FFMCR, the basic energy source is the kinetic energy of fission fragments. Following escape from thin fuel layers, they are captured on magnetic field lines and are directed out of the core and through magnetic collimators to produce electricity and thrust. The exiting flow of energetic fission fragments has a very high specific impulse that allows efficient planetary surface power and interstellar propulsion without carrying any conventional propellant onboard. The objective of this work was to determine technological feasibility of the concept. This objective was accomplished by producing the FFMCR design and by analysis of its performance characteristics. The paper presents the FFMCR concept, describes its development to a technologically feasible level and discusses obtained results. Performed studies offer efficiencies up to 90% and velocities approaching speed of light as potentially achievable. The unmanned 10-tons probe with 1000 MW FFMCR propulsion unit would attain mission velocity of about 2% of the speed of light. If the unit is designed for 4000 MW, then in 10 years the unmanned 10-tons probe would attain mission velocity of about 10% of the speed of light

Gross greenhouse gas fluxes from hydro-power reservoir compared to thermo-power plants

International Nuclear Information System (INIS)

Santos, Marco Aurelio dos; Pinguelli Rosa, Luiz; Sikar, Bohdan; Sikar, Elizabeth; Santos, Ednaldo Oliveira dos

2006-01-01

This paper presents the findings of gross carbon dioxide and methane emissions measurements in several Brazilian hydro-reservoirs, compared to thermo power generation. The term 'gross emissions' means gas flux measurements from the reservoir surface without natural pre-impoundment emissions by natural bodies such as the river channel, seasonal flooding and terrestrial ecosystems. The net emissions result from deducting pre-existing emissions by the reservoir. A power dam emits biogenic gases such as CO 2 and CH 4 . However, studies comparing gas emissions (gross emissions) from the reservoir surface with emissions by thermo-power generation technologies show that the hydro-based option presents better results in most cases analyzed. In this study, measurements were carried in the Miranda, Barra Bonita, Segredo, Tres Marias, Xingo, and Samuel and Tucurui reservoirs, located in two different climatological regimes. Additional data were used here from measurements taken at the Itaipu and Serra da Mesa reservoirs. Comparisons were also made between emissions from hydro-power plants and their thermo-based equivalents. Bearing in mind that the estimated values for hydro-power plants include emissions that are not totally anthropogenic, the hydro-power plants studied generally posted lower emissions than their equivalent thermo-based counterparts. Hydro-power complexes with greater power densities (capacity/area flooded-W/m 2 ), such as Itaipu, Xingo, Segredo and Miranda, have the best performance, well above thermo-power plants using state-of-the-art technology: combined cycle fueled by natural gas, with 50% efficiency. On the other hand, some hydro-power complexes with low-power density perform only slightly better or even worse than their thermo-power counterparts

Laser-powered Martian rover

Science.gov (United States)

Harries, W. L.; Meador, W. E.; Miner, G. A.; Schuster, Gregory L.; Walker, G. H.; Williams, M. D.

1989-01-01

Two rover concepts were considered: an unpressurized skeleton vehicle having available 4.5 kW of electrical power and limited to a range of about 10 km from a temporary Martian base and a much larger surface exploration vehicle (SEV) operating on a maximum 75-kW power level and essentially unrestricted in range or mission. The only baseline reference system was a battery-operated skeleton vehicle with very limited mission capability and range and which would repeatedly return to its temporary base for battery recharging. It was quickly concluded that laser powering would be an uneconomical overkill for this concept. The SEV, on the other hand, is a new rover concept that is especially suited for powering by orbiting solar or electrically pumped lasers. Such vehicles are visualized as mobile habitats with full life-support systems onboard, having unlimited range over the Martian surface, and having extensive mission capability (e.g., core drilling and sampling, construction of shelters for protection from solar flares and dust storms, etc.). Laser power beaming to SEV's was shown to have the following advantages: (1) continuous energy supply by three orbiting lasers at 2000 km (no storage requirements as during Martian night with direct solar powering); (2) long-term supply without replacement; (3) very high power available (MW level possible); and (4) greatly enhanced mission enabling capability beyond anything currently conceived.

Positron annihilation near fractal surfaces

International Nuclear Information System (INIS)

Lung, C.W.; Deng, K.M.; Xiong, L.Y.

1991-07-01

A model for positron annihilation in the sub-surface region near a fractal surface is proposed. It is found that the power law relationship between the mean positron implantation depth and incident positron energy can be used to measure the fractal dimension of the fractal surface in materials. (author). 10 refs, 2 figs

Durability-enhanced two-dimensional hole gas of C-H diamond surface for complementary power inverter applications.

Science.gov (United States)

Kawarada, Hiroshi; Yamada, Tetsuya; Xu, Dechen; Tsuboi, Hidetoshi; Kitabayashi, Yuya; Matsumura, Daisuke; Shibata, Masanobu; Kudo, Takuya; Inaba, Masafumi; Hiraiwa, Atsushi

2017-02-20

Complementary power field effect transistors (FETs) based on wide bandgap materials not only provide high-voltage switching capability with the reduction of on-resistance and switching losses, but also enable a smart inverter system by the dramatic simplification of external circuits. However, p-channel power FETs with equivalent performance to those of n-channel FETs are not obtained in any wide bandgap material other than diamond. Here we show that a breakdown voltage of more than 1600 V has been obtained in a diamond metal-oxide-semiconductor (MOS) FET with a p-channel based on a two-dimensional hole gas (2DHG). Atomic layer deposited (ALD) Al 2 O 3 induces the 2DHG ubiquitously on a hydrogen-terminated (C-H) diamond surface and also acts as both gate insulator and passivation layer. The high voltage performance is equivalent to that of state-of-the-art SiC planar n-channel FETs and AlGaN/GaN FETs. The drain current density in the on-state is also comparable to that of these two FETs with similar device size and V B .

Evaluation of Metal-Fueled Surface Reactor Concepts

International Nuclear Information System (INIS)

Poston, David I.; Marcille, Thomas F.; Kapernick, Richard J.; Hiatt, Matthew T.; Amiri, Benjamin W.

2007-01-01

Surface fission power systems for use on the Moon and Mars may provide the first use of near-term reactor technology in space. Most near-term surface reactor concepts specify reactor temperatures <1000 K to allow the use of established material and power conversion technology and minimize the impact of the in-situ environment. Metal alloy fuels (e.g. U-10Zr and U-10Mo) have not traditionally been considered for space reactors because of high-temperature requirements, but they might be an attractive option for these lower temperature surface power missions. In addition to temperature limitations, metal fuels are also known to swell significantly at rather low fuel burnups (∼1 a/o), but near-term surface missions can mitigate this concern as well, because power and lifetime requirements generally keep fuel burnups <1 a/o. If temperature and swelling issues are not a concern, then a surface reactor concept may be able to benefit from the high uranium density and relative ease of manufacture of metal fuels. This paper investigates two reactor concepts that utilize metal fuels. It is found that these concepts compare very well to concepts that utilize other fuels (UN, UO2, UZrH) on a mass basis, while also providing the potential to simplify material safeguards issues

Procedure for determining the optimum rate of increasing shaft depth

Energy Technology Data Exchange (ETDEWEB)

Durov, E.M.

1983-03-01

Presented is an economic analysis of increasing shaft depth during mine modernization. Investigations carried out by the Yuzhgiproshakht Institute are analyzed. The investigations are aimed at determining the optimum shaft sinking rate (the rate which reduces investment to the minimum). The following factors are considered: coal output of a mine (0.9, 1.2, 1.5 and 1.8 Mt/year), depth at which the new mining level is situated (600, 800, 1200, 1400 and 1600 m), four schemes of increasing depth of 2 central shafts (rock hoisting to ground surface, rock hoisting to the existing level, rock haulage to the developed level, rock haulage to the level being developed using a large diameter borehole drilled from the new level to the shaft bottom and enlarged from shaft bottom to the new level), shaft sinking rate (10, 20, 30, 40, 50 and 60 m/month), range of increasing shaft depth (the difference between depth of the shaft before and after increasing its depth by 100, 200, 300 and 400 m). Comparative evaluations show that the optimum shaft sinking rate depends on the scheme for rock hoisting (one of 4 analyzed), range of increasing shaft depth and gas content in coal seams. The optimum shaft sinking rate ranges from 20 to 40 m/month in coal mines with low methane content and from 20 to 30 m/month in gassy coal mines. The planned coal output of a mine does not influence the optimum shaft sinking rate.

A proposal of Transport System Improvement in exploiting and processing of raw materials

Directory of Open Access Journals (Sweden)

Ján Sciranko

2006-09-01

Full Text Available In handling earth, aggregate rock, ore, coal and other materials, trucks serve one purpose. They are hauling units which, because of their high speed when operating on suitable roads, have high capacities and provide relatively low hauling costs.They provide a high degree of flexibility as their number may be decreased or increased easily to permit modifications in the total hauling capacity of a fleet.In cyclic operations, the two principal operations are loading and haulage with hoisting as a third optional. In continuous operations, where machines combine the breakage and handling functions, cutting, drilling and blasting are eliminated and extraction and loading are performed in a single operation or function (excavation, e.g. the bucket wheel excavator, auger, highwall mines, continuous miner or the boring machine.Materials handling in modern mechanized mining is equipment oriented. Unit operations are characterized by, and sometimes identified with, an equipment that performs them. Thus the field terminology refers to a mining shovel, stripping dragline or the coal loader. From time to time the mining engineer is faced with the necessity to make a haulage study to determine not only the most suitable method of hauling materials, but also the most effective and economical type of equipment used for the operation. Key words: truck haulage, material handling, mining shovel

Scanning tunneling microscopy: A powerful tool for surface analysis

International Nuclear Information System (INIS)

Walle, G.F.A. van de; Nelissen, B.J.; Soethout, L.L.; Kempen, H. van

1987-01-01

The invention of the Scanning Tunneling Microscope (STM) has opened a new area of surface analysis. A description of the principle of operation is given in this paper. Also the technical problems encountered and their solution are described. Two examples demonstrating the possibilities of the STM are presented: topographic and spectroscopic measurements on a stepped Ni (111) surface and photoconductive measurements on GaAs. (orig.)

Effect of input power and gas pressure on the roughening and selective etching of SiO2/Si surfaces in reactive plasmas

International Nuclear Information System (INIS)

Zhong, X. X.; Huang, X. Z.; Tam, E.; Ostrikov, K.; Colpo, P.; Rossi, F.

2010-01-01

We report on the application low-temperature plasmas for roughening Si surfaces which is becoming increasingly important for a number of applications ranging from Si quantum dots to cell and protein attachment for devices such as 'laboratory on a chip' and sensors. It is a requirement that Si surface roughening is scalable and is a single-step process. It is shown that the removal of naturally forming SiO 2 can be used to assist in the roughening of the surface using a low-temperature plasma-based etching approach, similar to the commonly used in semiconductor micromanufacturing. It is demonstrated that the selectivity of SiO 2 /Si etching can be easily controlled by tuning the plasma power, working gas pressure, and other discharge parameters. The achieved selectivity ranges from 0.4 to 25.2 thus providing an effective means for the control of surface roughness of Si during the oxide layer removal, which is required for many advance applications in bio- and nanotechnology.

Cubesat SEP Power Module, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Today's CubeSats are inherently power limited due to their small size and available surface area. Today's CubeSats offer <100W of available power. This limits...

Open algebraic surfaces

CERN Document Server

Miyanishi, Masayoshi

2000-01-01

Open algebraic surfaces are a synonym for algebraic surfaces that are not necessarily complete. An open algebraic surface is understood as a Zariski open set of a projective algebraic surface. There is a long history of research on projective algebraic surfaces, and there exists a beautiful Enriques-Kodaira classification of such surfaces. The research accumulated by Ramanujan, Abhyankar, Moh, and Nagata and others has established a classification theory of open algebraic surfaces comparable to the Enriques-Kodaira theory. This research provides powerful methods to study the geometry and topology of open algebraic surfaces. The theory of open algebraic surfaces is applicable not only to algebraic geometry, but also to other fields, such as commutative algebra, invariant theory, and singularities. This book contains a comprehensive account of the theory of open algebraic surfaces, as well as several applications, in particular to the study of affine surfaces. Prerequisite to understanding the text is a basic b...

Economic statistics. Figures on mining in the Federal Republic of Germany from January until February 1977 on the basis of data from the statistics of the Kohenwirtschaft e. V

Energy Technology Data Exchange (ETDEWEB)

1977-05-01

The figures refer to haulage, briquetting, coke production, stockpiles, number of employees in hard coal and brown coal mining, and coal reprocessing during 1976 and the months of January and February of 1977.

Construction, specification, and mathematical description of aspheric surfaces.

Science.gov (United States)

Smith, G; Atchison, D A

1983-03-01

Rotationally symmetrical aspheric surfaces of spectacle lenses are constructed as either "zonal aspherics" or "continuous aspherics." Zonal aspherics consist of annular zones surrounding a central zone with each zone being nominally spherical with progressively lower surface power the farther the zone is from the surface vertex. Aspheric surfaces are often specified by the radial drop in surface power from the center to the edge of the lens (e.g., Welsh Four-drop), but for assessment purposes the surface shape must be specified more precisely. The formulas for the description of continuous aspherics can be manipulated into different forms. Mathematical descriptions are given or developed which will enable theoretical assessment of the performances of all lenses with rotationally symmetrical aspheric surfaces.

Verification of surface contamination density standard using clearance automatic laser inspection system for objects from a nuclear power plant

International Nuclear Information System (INIS)

Sasaki, Michiya; Ogino, Haruyuki; Ichiji, Takeshi; Hattori, Takatoshi

2008-01-01

In the clearance level inspection in Japan, it is necessary to indicate that the activity level of the target object must be less than not only the clearance levels, but also the surface contamination density standards. The classification measurements for these two standards have been performed separately, and the GM survey meters based on beta-ray measurement have mainly been used for surface contamination density measurement so far. Recently the Clearance Automatic Laser Inspection System, named CLALIS, has been developed to estimate the low-level activity concentration. This system consists of 3-dimensional laser scanner for shape measurement and eight large NE102A plastic scintillation detectors for gamma-ray measurement, and it has been clarified that the CLALIS has adequate detection ability for clearance measurement of both metal scraps and concrete debris. In this study, we compared the surface contamination densities for a number of actual contaminated and non-contaminated objects generated inside from the radiation controlled area at the Kashiwazaki-Kariwa nuclear power station by using the CLALIS and the GM survey meter. As a result, since CLALIS could detect the surface contamination as well as the GM survey meter for all measurement targets, it was revealed that CLALIS can rationally achieve clearance level inspection in a single radiation measurement. The practicality of CLALIS in view of the detection limit and processing time was discussed by comparison with the usual radiation monitors for surface contamination measurement. (author)

Influences of bulk and surface recombinations on the power conversion efficiency of perovskite solar cells

International Nuclear Information System (INIS)

Xie, Ziang; Sun, Shuren; Yan, Yu; Wang, Wei; Qin, Laixiang; Qin, G G

2016-01-01

For a novel kind of solar cell (SC) material, it is critical to estimate how far the power conversion efficiencies (PCEs) of the SCs made of it can go. In 2010 Han and Chen proposed the equation for the ultimate efficiency of SCs without considering the carrier recombination η un . η un is capable of estimating the theoretical upper limits of the SC efficiencies and has attracted much attention. However, carrier recombination, which is one of the key factors influencing the PCEs of the SCs, is ignored in the equation for η un . In this paper, we develop a novel equation to calculate the ultimate efficiency for the SCs, η ur , which considers both the bulk and the surface carrier recombinations. The novel equation for η ur can estimate how much the bulk and the surface carrier recombinations influence the PCEs of the SCs. Moreover, with η ur we can estimate how much PCE improvement space can be gained only by reducing the influence of the carrier recombination to the least. The perovskite organometal trihalide SCs have attracted tremendous attention lately. For the planar CH 3 NH 3 PbI 3 SCs, in the material depth range from 31.25–2000 nm, we apply the equation of η ur to investigate how the bulk and the surface carrier recombinations affect PCE. From a typically reported PCE of 15% for the planar CH 3 NH 3 PbI 3 SC, using the equation of η ur , it is concluded that by reducing the influence of carrier recombination to the least the improvement of PCE is in the range of 17–30%. (paper)

Analysis of superconducting microstrip resonator at various microwave power levels

International Nuclear Information System (INIS)

Srivastava, G.P.; Jacob, M.V.; Jayakumar, M.; Bhatnagar, P.K.; Kataria, N.D.

1997-01-01

The real and imaginary parts of the surface impedance of YBCO superconductors have been studied at different microwave power levels. Using the relations for the critical current density and the grain boundary resistance, a relation for calculating the power dependence of the surface resistance has been obtained. Also, a relation to find the resonant frequency of a superconducting microstrip resonator at various input power levels has been derived. Measurements have been carried out on various microstrip resonators to study the variation of surface resistance and resonant frequency at different rf power levels. The experimental results are in good agreement with theoretical results. copyright 1997 American Institute of Physics

Natural Contamination and Surface Flashover on Silicone Rubber Surface under Haze–Fog Environment

Directory of Open Access Journals (Sweden)

Ang Ren

2017-10-01

Full Text Available Anti-pollution flashover of insulator is important for power systems. In recent years, haze-fog weather occurs frequently, which makes discharge occurs easily on the insulator surface and accelerates insulation aging of insulator. In order to study the influence of haze-fog on the surface discharge of room temperature vulcanized silicone rubber, an artificial haze-fog lab was established. Based on four consecutive years of insulator contamination accumulation and atmospheric sampling in haze-fog environment, the contamination configuration appropriate for RTV-coated surface discharge test under simulation environment of haze-fog was put forward. ANSYS Maxwell was used to analyze the influence of room temperature vulcanized silicone rubber surface attachments on electric field distribution. The changes of droplet on the polluted room temperature vulcanized silicone rubber surface and the corresponding surface flashover voltage under alternating current (AC, direct current (DC positive polar (+, and DC negative polar (− power source were recorded by a high speed camera. The results are as follows: The main ion components from haze-fog atmospheric particles are NO3−, SO42−, NH4+, and Ca2+. In haze-fog environment, both the equivalent salt deposit density (ESDD and non-soluble deposit density (NSDD of insulators are higher than that under general environment. The amount of large particles on the AC transmission line is greater than that of the DC transmission line. The influence of DC polarity power source on the distribution of contamination particle size is not significant. After the deposition of haze-fog, the local conductivity of the room temperature vulcanized silicone rubber surface increased, which caused the flashover voltage reduce. Discharge is liable to occur at the triple junction point of droplet, air, and room temperature vulcanized silicone rubber surface. After the deformation or movement of droplets, a new triple junction

Measurement of the surface-enhanced coherent anti-Stokes Raman scattering (SECARS) due to the 1574 cm(-1) surface-enhanced Raman scattering (SERS) mode of benzenethiol using low-power (CW diode lasers.

Science.gov (United States)

Aggarwal, Roshan L; Farrar, Lewis W; Greeneltch, Nathan G; Van Duyne, Richard P; Polla, Dennis L

2013-02-01

The surface-enhanced coherent anti-Stokes Raman scattering (SECARS) from a self-assembled monolayer (SAM) of benzenethiol on a silver-coated surface-enhanced Raman scattering (SERS) substrate has been measured for the 1574 cm(-1) SERS mode. A value of 9.6 ± 1.7×10(-14) W was determined for the resonant component of the SECARS signal using 17.8 mW of 784.9 nm pump laser power and 7.1 mW of 895.5 nm Stokes laser power; the pump and Stokes lasers were polarized parallel to each other but perpendicular to the grooves of the diffraction grating in the spectrometer. The measured value of resonant component of the SECARS signal is in agreement with the calculated value of 9.3×10(-14) W using the measured value of 8.7 ± 0.5 cm(-1) for the SERS linewidth Γ (full width at half-maximum) and the value of 5.7 ± 1.4×10(-7) for the product of the Raman cross section σSERS and the surface concentration Ns of the benzenethiol SAM. The xxxx component of the resonant part of the third-order nonlinear optical susceptibility |3 χxxxx((3)R)| for the 1574 cm(-1) SERS mode has been determined to be 4.3 ± 1.1×10(-5) cm·g(-1)·s(2). The SERS enhancement factor for the 1574 cm(-1) mode was determined to be 3.6 ± 0.9×10(7) using the value of 1.8×10(15) molecules/cm(2) for Ns.

Rail projects gather steam

Energy Technology Data Exchange (ETDEWEB)

NONE

2010-01-15

The global recession hit rail companies hard, as demand for bulk commodities such as coal was affected. But green shoots of recovery are now appearing, with many rail companies announcing new haulage contracts. 3 figs.

Screening of mine dirt as addition to concrete. Description of testing plant. Results

Energy Technology Data Exchange (ETDEWEB)

Gnodtke, M

1977-08-01

An experimental facility for screening mine dirt during haulage operations is described. The screening material, adding sand and a binder, can be made into a concrete aggregate at low costs and used as backfilling material.

On the nature of surface roughness with application to contact mechanics, sealing, rubber friction and adhesion

International Nuclear Information System (INIS)

Persson, B N J; Albohr, O; Tartaglino, U; Volokitin, A I; Tosatti, E

2005-01-01

Surface roughness has a huge impact on many important phenomena. The most important property of rough surfaces is the surface roughness power spectrum C(q). We present surface roughness power spectra of many surfaces of practical importance, obtained from the surface height profile measured using optical methods and the atomic force microscope. We show how the power spectrum determines the contact area between two solids. We also present applications to sealing, rubber friction and adhesion for rough surfaces, where the power spectrum enters as an important input. (topical review)

Design of a nuclear-powered rover for lunar or Martian exploration

International Nuclear Information System (INIS)

Trellue, H.R.; Trautner, R.; Houts, M.G.; Poston, D.I.; Giovig, K.; Baca, J.A.; Lipinski, R.J.

1998-08-01

To perform more advanced studies on the surface of the moon or Mars, a rover must provide long-term power (≥10 kW e ). However, a majority of rovers in the past have been designed for much lower power levels (i.e., on the order of watts) or for shorter operating periods using stored power. Thus, more advanced systems are required to generate additional power. One possible design for a more highly powered rover involves using a nuclear reactor to supply energy to the rover and material from the surface of the moon or Mars to shield the electronics from high neutron fluxes and gamma doses. Typically, one of the main disadvantages of using a nuclear-powered rover is that the required shielding would be heavy and expensive to include as part of the payload on a mission. Obtaining most of the required shielding material from the surface of the moon or Mars would reduce the cost of the mission and still provide the necessary power. This paper describes the basic design of a rover that uses the Heatpipe Power System (HPS) as an energy source, including the shielding and reactor control issues associated with the design. It also discusses briefly the amount of power that can be produced by other power methods (solar/photovoltaic cells, radioisotope power supplies, dynamic radioisotope power systems, and the production of methane or acetylene fuel from the surface of Mars) as a comparison to the HPS

Effective Low-Power Wearable Wireless Surface EMG Sensor Design Based on Analog-Compressed Sensing

Directory of Open Access Journals (Sweden)

Mohammadreza Balouchestani

2014-12-01

Full Text Available Surface Electromyography (sEMG is a non-invasive measurement process that does not involve tools and instruments to break the skin or physically enter the body to investigate and evaluate the muscular activities produced by skeletal muscles. The main drawbacks of existing sEMG systems are: (1 they are not able to provide real-time monitoring; (2 they suffer from long processing time and low speed; (3 they are not effective for wireless healthcare systems because they consume huge power. In this work, we present an analog-based Compressed Sensing (CS architecture, which consists of three novel algorithms for design and implementation of wearable wireless sEMG bio-sensor. At the transmitter side, two new algorithms are presented in order to apply the analog-CS theory before Analog to Digital Converter (ADC. At the receiver side, a robust reconstruction algorithm based on a combination of ℓ1-ℓ1-optimization and Block Sparse Bayesian Learning (BSBL framework is presented to reconstruct the original bio-signals from the compressed bio-signals. The proposed architecture allows reducing the sampling rate to 25% of Nyquist Rate (NR. In addition, the proposed architecture reduces the power consumption to 40%, Percentage Residual Difference (PRD to 24%, Root Mean Squared Error (RMSE to 2%, and the computation time from 22 s to 9.01 s, which provide good background for establishing wearable wireless healthcare systems. The proposed architecture achieves robust performance in low Signal-to-Noise Ratio (SNR for the reconstruction process.

Increasing power generation for scaling up single-chamber air cathode microbial fuel cells

KAUST Repository

Cheng, Shaoan; Logan, Bruce E.

2011-01-01

Scaling up microbial fuel cells (MFCs) requires a better understanding the importance of the different factors such as electrode surface area and reactor geometry relative to solution conditions such as conductivity and substrate concentration. It is shown here that the substrate concentration has significant effect on anode but not cathode performance, while the solution conductivity has a significant effect on the cathode but not the anode. The cathode surface area is always important for increasing power. Doubling the cathode size can increase power by 62% with domestic wastewater, but doubling the anode size increases power by 12%. Volumetric power density was shown to be a linear function of cathode specific surface area (ratio of cathode surface area to reactor volume), but the impact of cathode size on power generation depended on the substrate strength (COD) and conductivity. These results demonstrate the cathode specific surface area is the most critical factor for scaling-up MFCs to obtain high power densities. © 2010 Elsevier Ltd.

Increasing power generation for scaling up single-chamber air cathode microbial fuel cells

KAUST Repository

Cheng, Shaoan

2011-03-01

Scaling up microbial fuel cells (MFCs) requires a better understanding the importance of the different factors such as electrode surface area and reactor geometry relative to solution conditions such as conductivity and substrate concentration. It is shown here that the substrate concentration has significant effect on anode but not cathode performance, while the solution conductivity has a significant effect on the cathode but not the anode. The cathode surface area is always important for increasing power. Doubling the cathode size can increase power by 62% with domestic wastewater, but doubling the anode size increases power by 12%. Volumetric power density was shown to be a linear function of cathode specific surface area (ratio of cathode surface area to reactor volume), but the impact of cathode size on power generation depended on the substrate strength (COD) and conductivity. These results demonstrate the cathode specific surface area is the most critical factor for scaling-up MFCs to obtain high power densities. © 2010 Elsevier Ltd.

Removal of pollutants with determination of power consumption from landfill leachate wastewater using an electrocoagulation process: optimization using response surface methodology (RSM)

Science.gov (United States)

Asaithambi, Perumal; Beyene, Dejene; Aziz, Abdul Raman Abdul; Alemayehu, Esayas

2018-05-01

Treatment of landfill leachate wastewater by electrocoagulation process using an aluminium electrode was investigated in a batch electrochemical cell reactor. Response surface methodology based on central composite design was used to optimize the operating parameters for the removal of % color and % total organic carbon (TOC) together with power consumption from landfill leachate. Effects of three important independent parameters such as current density ( X 1), inter-electrode distance ( X 2) and solution pH ( X 3) of the landfill leachate sample on the % color and % TOC removal with power consumption were investigated. A quadratic model was used to predict the % color and % TOC removal with power consumption in different experimental conditions. The significance of each independent variable was calculated by analysis of variance. In order to achieve the maximum % color and % TOC removal with minimum of power consumption, the optimum conditions were about current density ( X 1)—5.25 A/dm2, inter-electrode distance ( X 2)—1 cm and initial solution of effluent pH ( X 3)—7.83, with the yield of color removal of 74.57%, and TOC removal of 51.75% with the power consumption of 14.80 kWh/m3. Electrocoagulation process could be applied to remove pollutants from industrial effluents and wastewater.

Artificial intelligence analysis of paraspinal power spectra.

Science.gov (United States)

Oliver, C W; Atsma, W J

1996-10-01

OBJECTIVE: As an aid to discrimination of sufferers with back pain an artificial intelligence neural network was constructed to differentiate paraspinal power spectra. DESIGN: Clinical investigation using surface electromyography. METHOD: The surface electromyogram power spectra from 60 subjects, 33 non-back-pain sufferers and 27 chronic back pain sufferers were used to construct a back propagation neural network that was then tested. Subjects were placed on a test frame in 30 degrees of lumbar forward flexion. An isometric load of two-thirds maximum voluntary contraction was held constant for 30 s whilst surface electromyograms were recorded at the level of the L(4-5). Paraspinal power spectra were calculated and loaded into the input layer of a three-layer back propagation network. The neural network classified the spectra into normal or back pain type. RESULTS: The back propagation neural was shown to have satisfactory convergence with a specificity of 79% and a sensitivity of 80%. CONCLUSIONS: Artificial intelligence neural networks appear to be a useful method of differentiating paraspinal power spectra in back-pain sufferers.

30 CFR 57.12017 - Work on power circuits.

Science.gov (United States)

2010-07-01

... shall prevent the power circuits from being energized without the knowledge of the individuals working... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Work on power circuits. 57.12017 Section 57... Surface and Underground § 57.12017 Work on power circuits. Power circuits shall be deenergized before work...

Scientific Research Program for Power, Energy, and Thermal Technologies. Task Order 0001: Energy, Power, and Thermal Technologies and Processes Experimental Research. Subtask: Thermal Management of Electromechanical Actuation System for Aircraft Primary Flight Control Surfaces

Science.gov (United States)

2014-05-01

Computer FHPCP Flexible Heat Pipe Cold Plate HPEAS High Performance Electric Actuation System HPU Hydraulic Power Unit HSM Hydraulic Service...provide improved thermal paths and phase change materials offer energy storage. Loop heat pipes (LHP’s) and Flexible Heat Pipe Cold Plates (FHPCP’s...flows upward due to density difference through centrally located vapor channels called risers and then condenses on the colder surface associated

A short review of radiation-induced raft-mediated graft copolymerization: A powerful combination for modifying the surface properties of polymers in a controlled manner

Science.gov (United States)

Barsbay, Murat; Güven, Olgun

2009-12-01

Surface grafting of polymeric materials is attracting increasing attention as it enables the preparation of new materials from known and commercially available polymers having desirable bulk properties such as thermal stability, elasticity, permeability, etc., in conjunction with advantageous newly tailored surface properties such as biocompatibility, biomimicry, adhesion, etc. Ionizing radiation, particularly γ radiation is one of the most powerful tools for preparing graft copolymers as it generates radicals on most substrates. With the advent of living free-radical polymerization techniques, application of γ radiation has been extended to a new era of grafting; grafting in a controlled manner to achieve surfaces with tailored and well-defined properties. This report presents the current use of γ radiation in living free-radical polymerization and highlights the use of both techniques together as a combination to present an advance in the ability to prepare surfaces with desired, tunable and well-defined properties.

A short review of radiation-induced raft-mediated graft copolymerization: A powerful combination for modifying the surface properties of polymers in a controlled manner

International Nuclear Information System (INIS)

Barsbay, Murat; Gueven, Olgun

2009-01-01

Surface grafting of polymeric materials is attracting increasing attention as it enables the preparation of new materials from known and commercially available polymers having desirable bulk properties such as thermal stability, elasticity, permeability, etc., in conjunction with advantageous newly tailored surface properties such as biocompatibility, biomimicry, adhesion, etc. Ionizing radiation, particularly γ radiation is one of the most powerful tools for preparing graft copolymers as it generates radicals on most substrates. With the advent of living free-radical polymerization techniques, application of γ radiation has been extended to a new era of grafting; grafting in a controlled manner to achieve surfaces with tailored and well-defined properties. This report presents the current use of γ radiation in living free-radical polymerization and highlights the use of both techniques together as a combination to present an advance in the ability to prepare surfaces with desired, tunable and well-defined properties.

A short review of radiation-induced raft-mediated graft copolymerization: A powerful combination for modifying the surface properties of polymers in a controlled manner

Energy Technology Data Exchange (ETDEWEB)

Barsbay, Murat [Department of Chemistry, Hacettepe University, 06800 Beytepe, Ankara (Turkey)], E-mail: mbarsbay@hacettepe.edu.tr; Gueven, Olgun [Department of Chemistry, Hacettepe University, 06800 Beytepe, Ankara (Turkey)], E-mail: guven@hacettepe.edu.tr

2009-12-15

Surface grafting of polymeric materials is attracting increasing attention as it enables the preparation of new materials from known and commercially available polymers having desirable bulk properties such as thermal stability, elasticity, permeability, etc., in conjunction with advantageous newly tailored surface properties such as biocompatibility, biomimicry, adhesion, etc. Ionizing radiation, particularly {gamma} radiation is one of the most powerful tools for preparing graft copolymers as it generates radicals on most substrates. With the advent of living free-radical polymerization techniques, application of {gamma} radiation has been extended to a new era of grafting; grafting in a controlled manner to achieve surfaces with tailored and well-defined properties. This report presents the current use of {gamma} radiation in living free-radical polymerization and highlights the use of both techniques together as a combination to present an advance in the ability to prepare surfaces with desired, tunable and well-defined properties.

Lower-extremity resistance training on unstable surfaces improves proxies of muscle strength, power and balance in healthy older adults: a randomised control trial.

Science.gov (United States)

Eckardt, Nils

2016-11-24

It is well documented that both balance and resistance training have the potential to mitigate intrinsic fall risk factors in older adults. However, knowledge about the effects of simultaneously executed balance and resistance training (i.e., resistance training conducted on unstable surfaces [URT]) on lower-extremity muscle strength, power and balance in older adults is insufficient. The objective of the present study was to compare the effects of machine-based stable resistance training (M-SRT) and two types of URT, i.e., machine-based (M-URT) and free-weight URT (F-URT), on measures of lower-extremity muscle strength, power and balance in older adults. Seventy-five healthy community-dwelling older adults aged 65-80 years, were assigned to three intervention groups: M-SRT, M-URT and F-URT. Over a period of ten weeks, all participants exercised two times per week with each session lasting ~60 min. Tests included assessment of leg muscle strength (e.g., maximal isometric leg extension strength), power (e.g., chair rise test) and balance (e.g., functional reach test), carried out before and after the training period. Furthermore, maximal training load of the squat-movement was assessed during the last training week. Maximal training load of the squat-movement was significantly lower in F-URT in comparison to M-SRT and M-URT. However, lower-extremity resistance training conducted on even and uneven surfaces meaningfully improved proxies of strength, power and balance in all groups. M-URT produced the greatest improvements in leg extension strength and F-URT in the chair rise test and functional reach test. Aside from two interaction effects, overall improvements in measures of lower-extremity muscle strength, power and balance were similar across training groups. Importantly, F-URT produced similar results with considerably lower training load as compared to M-SRT and M-URT. Concluding, F-URT seems an effective and safe alternative training program to mitigate

Progress in surface and membrane science

CERN Document Server

Cadenhead, D A

1977-01-01

Progress in Surface and Membrane Science, Volume 11 covers the advances in the study of surface and membrane science. The book discusses the quantum theory of surface phenomena; some fundamental aspects of electrocrystallization; and exoelectric emission. The text also describes the surface of titanium dioxide; and the prospects for atomic resolution electron microscopy in membranology. Chemists, physicists, and people involved in the electrochemical power laboratory will find the book useful.

Topographic power spectral density study of the effect of surface treatment processes on niobium for superconducting radio frequency accelerator cavities

Science.gov (United States)

Xu, Chen; Tian, Hui; Reece, Charles E.; Kelley, Michael J.

2012-04-01

Microroughness is viewed as a critical issue for attaining optimum performance of superconducting radio frequency accelerator cavities. The principal surface smoothing methods are buffered chemical polish (BCP) and electropolish (EP). The resulting topography is characterized by atomic force microscopy (AFM). The power spectral density (PSD) of AFM data provides a more thorough description of the topography than a single-value roughness measurement. In this work, one dimensional average PSD functions derived from topography of BCP and EP with different controlled starting conditions and durations have been fitted with a combination of power law, K correlation, and shifted Gaussian models to extract characteristic parameters at different spatial harmonic scales. While the simplest characterizations of these data are not new, the systematic tracking of scale-specific roughness as a function of processing is new and offers feedback for tighter process prescriptions more knowledgably targeted at beneficial niobium topography for superconducting radio frequency applications.

Topographic power spectral density study of the effect of surface treatment processes on niobium for superconducting radio frequency accelerator cavities

International Nuclear Information System (INIS)

Reece, Charles; Tian, Hui; Kelley, Michael; Xu, Chen

2012-01-01

Microroughness is viewed as a critical issue for attaining optimum performance of superconducting radio frequency accelerator cavities. The principal surface smoothing methods are buffered chemical polish (BCP) and electropolish (EP). The resulting topography is characterized by atomic force microscopy (AFM). The power spectral density (PSD) of AFM data provides a more thorough description of the topography than a single-value roughness measurement. In this work, one dimensional average PSD functions derived from topography of BCP and EP with different controlled starting conditions and durations have been fitted with a combination of power law, K correlation, and shifted Gaussian models to extract characteristic parameters at different spatial harmonic scales. While the simplest characterizations of these data are not new, the systematic tracking of scale-specific roughness as a function of processing is new and offers feedback for tighter process prescriptions more knowledgably targeted at beneficial niobium topography for superconducting radio frequency applications.

War Powers Litigation Initiated by Members of Congress Since the Enactment of the War Powers Resolution

Science.gov (United States)

2012-02-17

separation of powers . Prominent on the surface of any case held to involve a political question is found a textually demonstrable constitutional...and the U.S. Court of Appeals for the District of Columbia again affirmed. The district court stated as a predicate that the separation of powers doctrine...grave separation of powers issues” and observed that courts traditionally have been reluctant “to intercede in disputes between the political

Surface and microstructure modifications of Ti-6Al-4V titanium alloy cutting by a water jet/high power laser converging coupling

Science.gov (United States)

Weiss, Laurent; Tazibt, Abdel; Aillerie, Michel; Tidu, Albert

2018-01-01

The metallurgical evolution of the Ti-6Al-4V samples is analyzed after an appropriate cutting using a converging water jet/high power laser system. New surface microstructures are obtained on the cutting edge as a result of thermo-mechanical effects of such hybrid fluid-jet-laser tool on the targeted material. The laser beam allows to melt and the water-jet to cool down and to evacuate the material upstream according to a controlled cutting process. The experimental results have shown that a rutile layer can be generated on the surface near the cutting zone. The recorded metallurgical effect is attributed to the chemical reaction between water molecules and titanium, where the laser thermal energy brought onto the surface plays the role of reaction activator. The width of the oxidized zone was found proportional to the cutting speed. During the reaction, hydrogen gas H2 is formed and is absorbed by the metal. The hydrogen atoms trapped into the alloy change the metastable phase formation developing pure β circular grains as a skin at the kerf surface. This result is original so it would lead to innovative converging laser water jet process that could be used to increase the material properties especially for surface treatment, a key value of surface engineering and manufacturing chains.

3D thermal model of laser surface glazing for H13 tool steel

Science.gov (United States)

Kabir, I. R.; Yin, D.; Naher, S.

2017-10-01

In this work a three dimensional (3D) finite element model of laser surface glazing (LSG) process has been developed. The purpose of the 3D thermal model of LSG was to achieve maximum accuracy towards the predicted outcome for optimizing the process. A cylindrical geometry of 10mm diameter and 1mm length was used in ANSYS 15 software. Temperature distribution, depth of modified zone and cooling rates were analysed from the thermal model. Parametric study was carried out varying the laser power from 200W-300W with constant beam diameter and residence time which were 0.2mm and 0.15ms respectively. The maximum surface temperature 2554°K was obtained for power 300W and minimum surface temperature 1668°K for power 200W. Heating and cooling rates increased with increasing laser power. The depth of the laser modified zone attained for 300W power was 37.5µm and for 200W power was 30µm. No molten zone was observed at 200W power. Maximum surface temperatures obtained from 3D model increased 4% than 2D model presented in author's previous work. In order to verify simulation results an analytical solution of temperature distribution for laser surface modification was used. The surface temperature after heating was calculated for similar laser parameters which is 1689°K. The difference in maximum surface temperature is around 20.7°K between analytical and numerical analysis of LSG for power 200W.

Assessing effects of chemical treatment on mechanical properties of transported anthracite

Energy Technology Data Exchange (ETDEWEB)

Danil' chenko, I M; Sukhanov, V V; Putilina, O.N.

1984-10-01

A method is discussed for control of anthracite comminution during coal haulage in underground mines. Coal hauled by belt conveyors was sprayed with MFF-M urea formaldehyde resin and oxalic acid used as a hardener. Design of the UAP experimental spraying system successfully tested in some coal mines in the Donbass is shown in a scheme. Effects of anthracite spraying on toxicity of fire gases were analyzed. Gas emission was analyzed at 300 C and at 1000 C. Content of the following compounds in fire gases was determined: hydrocyanic acid, ammonia, nitrogen oxides, formaldehyde, methanol. Evaluations showed that toxicity increase was within the permissible limits with the exception of hydrocyanic acid. In the case of underground fires in areas of haulage lines with resin spraying systems, members of rescue teams should use special equipment protecting the respiratory system from hydrocyanic acid. 2 references.

Glancing-angle scattering of fast ions at crystal surfaces

Energy Technology Data Exchange (ETDEWEB)

Mannami, Michihiko; Narumi, Kazumasa; Katoh, Humiya; Kimura, Kenji [Kyoto Univ. (Japan). Faculty of Engineering

1997-03-01

Glancing angle scattering of fast ions from a single crystal surface is a novel technique to study ion-surface interaction. Results of recent studies of ion-surface interaction are reviewed for ions with velocities faster than the Fermi velocity of solid. For the ions with velocities less than the Fermi velocity of target valence electrons the ion-surface interaction shows a new aspect where only the valence electrons of target solid participate in the stopping processes. It will show that the position-dependent stopping power of a surface for these ions governed by the elastic collisions of valence electrons and the ions. A method is proposed from this position-dependent stopping power to derived the electron density distribution averaged over the plane parallel to the surface. (author)

Spatial distribution of Iodine-129 in surface soil around the Fukushima Daiichi Nuclear Power Plant

International Nuclear Information System (INIS)

Miyake, Yasuto; Tagi, Kazuhiro; Matsuzaki, Hiroyuki; Fujiwara, Takeshi; Saito, Takumi; Yamagata, Takeyasu; Tsuchiya, Yoko; Nakano, Chuichiro; Honda, Maki

2011-01-01

Due to the accident at the Fukushima Daiichi nuclear power plant, which was caused by the Great East Japan Earthquake, a lot of radioactive materials were released into the environment. Among them, Iodine-131, which has a short half-life of 8 days, is thought to be hardly detected after the accident is concluded. It is very important to research how leaked out Iodine-131 was diffused in order to estimate the health impact of radiation at the time of the accident. On the other hand, Iodine-129, which was leaked out and was thought to act chemically-identically as Iodine-131, has an extremely long half-life of 15.7 million years and we are able to measure it equally after the accident. By following the trail of Iodine-129, it is considered to estimate the distribution of Iodine-131. To do this, at first, it is essential to measure simultaneously Iodine-131 and Iodine-129 in the same sample picked from near-the Fukushima Daiichi nuclear power plant and examine the relation between them (for example, the isotopic ratio of Iodine derived from the nuclear power plant (I-129/I-131)). At this study, we measured Iodine-129 in surface soil within 60 kilometers of the Fukushima Daiichi nuclear power plant, which was picked by research team of Nuclear Engineering Research Laboratory, Faculty of Engineering, the University of Tokyo. We discuss Iodine-129 derived from the nuclear power plant by considering the concentration range, the relation of a distance or a direction from the nuclear power plant, and the relation between I-129 and other radioactive nuclides (Cs-134, Cs-137, I-131). Since Iodine-129, which had been leaked out from the nuclear fuel reprocessing plant in Europe, was already transferred to Japan by way of the atmospheric transportation before the accident, it is important to distinguish between Iodine-129 from this accident and from the reprocessing plant. Then, we want to obtain the I-129/I-131 ratio originating in the accident precisely and discuss the

Enhanced Output Power of PZT Nanogenerator by Controlling Surface Morphology of Electrode.

Science.gov (United States)

Jung, Woo-Suk; Lee, Won-Hee; Ju, Byeong-Kwon; Yoon, Seok-Jin; Kang, Chong-Yun

2015-11-01

Piezoelectric power generation using Pb(Zr,Ti)O3(PZT) nanowires grown on Nb-doped SrTiO3(nb:STO) substrate has been demonstrated. The epitaxial PZT nanowires prepared by a hydrothermal method, with a diameter and length of approximately 300 nm and 7 μm, respecively, were vertically aligned on the substrate. An embossed Au top electrode was applied to maximize the effective power generation area for non-uniform PZT nanowires. The PZT nanogenerator produced output power density of 0.56 μW/cm2 with a voltage of 0.9 V and current of 75 nA. This research suggests that the morphology control of top electrode can be useful to improve the efficiency of piezoelectric power generation.

Experimental assessment of blade tip immersion depth from free surface on average power and thrust coefficients of marine current turbine

Science.gov (United States)

Lust, Ethan; Flack, Karen; Luznik, Luksa

2014-11-01

Results from an experimental study on the effects of marine current turbine immersion depth from the free surface are presented. Measurements are performed with a 1/25 scale (diameter D = 0.8m) two bladed horizontal axis turbine towed in the large towing tank at the U.S. Naval Academy. Thrust and torque are measured using a dynamometer, mounted in line with the turbine shaft. Shaft rotation speed and blade position are measured using a shaft position indexing system. The tip speed ratio (TSR) is adjusted using a hysteresis brake which is attached to the output shaft. Two optical wave height sensors are used to measure the free surface elevation. The turbine is towed at 1.68 m/s, resulting in a 70% chord based Rec = 4 × 105. An Acoustic Doppler Velocimeter (ADV) is installed one turbine diameter upstream of the turbine rotation plane to characterize the inflow turbulence. Measurements are obtained at four relative blade tip immersion depths of z/D = 0.5, 0.4, 0.3, and 0.2 at a TSR value of 7 to identify the depth where free surface effects impact overall turbine performance. The overall average power and thrust coefficient are presented and compared to previously conducted baseline tests. The influence of wake expansion blockage on the turbine performance due to presence of the free surface at these immersion depths will also be discussed.

Special Application Thermoelectric Micro Isotope Power Sources

International Nuclear Information System (INIS)

Heshmatpour, Ben; Lieberman, Al; Khayat, Mo; Leanna, Andrew; Dobry, Ted

2008-01-01

Promising design concepts for milliwatt (mW) size micro isotope power sources (MIPS) are being sought for use in various space and terrestrial applications, including a multitude of future NASA scientific missions and a range of military applications. To date, the radioisotope power sources (RPS) used on various space and terrestrial programs have provided power levels ranging from one-half to several hundred watts. In recent years, the increased use of smaller spacecraft and planned new scientific space missions by NASA, special terrestrial and military applications suggest the need for lower power, including mW level, radioisotope power sources. These power sources have the potential to enable such applications as long-lived meteorological or seismological stations distributed across planetary surfaces, surface probes, deep space micro-spacecraft and sub-satellites, terrestrial sensors, transmitters, and micro-electromechanical systems. The power requirements are in the range of 1 mW to several hundred mW. The primary technical requirements for space applications are long life, high reliability, high specific power, and high power density, and those for some special military uses are very high power density, specific power, reliability, low radiological induced degradation, and very low radiation leakage. Thermoelectric conversion is of particular interest because of its technological maturity and proven reliability. This paper summarizes the thermoelectric, thermal, and radioisotope heat source designs and presents the corresponding performance for a number of mW size thermoelectric micro isotope power sources

LHC Power Distribution

CERN Document Server

Pedersen, J

1999-01-01

The power distribution for the LHC machine and its experiments will be realised making extensive use of the existing infrastructure for the LEP. The overall power requirement is approximately the same, about 125 MW. The load distribution will however change. The even points will loose in importance and the points 1 and 5 will, due to the installation of ATLAS and CMS, gain. A thorough reorganisation of the 18 kV distribution will thus be necessary. Due to the important cryogenic installations required for the LHC, the 3.3 kV distribution system, supplying mainly cryogenic compressors, will be extended with a number of new substations. The important number of new surface buildings, underground caverns and other underground structures all will receive general service installations: Lighting and power. The new injection tunnels will require complete installations: A.C. supplies for the power converters and for general service, and D.C. cabling for the magnets of the beam line. Special safe power installations ar...

An investigation of laser processing of silica surfaces

International Nuclear Information System (INIS)

Weber, A.J.; Stewart, A.F.; Exarhos, G.J.; Stowell, W.K.

1988-01-01

An initial set of experiments has been conducted to determine the practicality of laser processing of optical substrates. In contrast to earlier work, a high average power CO 2 laser was used to flood load the entire surface of each test sample. Fused silica substrates were laser polished on both surfaces at power densities ranging from 150 to 350 W/cm 2 . During each test sequence sample surface temperatures were recorded using a thermal imaging system. Extensive pre- and post-test characterization revealed that surface roughness and scattering of bare silica surfaces were reduced while internal stress increased. Laser damage thresholds were found to increase only for certain conditions. Changes in the microstructure were observed. These preliminary experiments demonstrate that laser processing can dramatically improve the optical properties of fused silica substrates

Ultrasound enhanced plasma surface modification at atmospheric pressure

DEFF Research Database (Denmark)

Kusano, Yukihiro; Singh, Shailendra Vikram; Norrman, Kion

and the material surface, and thus many reactive species generated in the plasma can reach the surface before inactivated, and be efficiently utilized for surface modification. In the present work polyester plates are treated using a dielectric barrier discharge (DBD) and a gliding arc at atmospheric pressure......Atmospheric pressure plasma treatment can be highly enhanced by simultaneous high-power ultrasonic irradiation onto the treating surface. It is because ultrasonic waves with a sound pressure level (SPL) above approximately 140 dB can reduce the thickness of a boundary gas layer between the plasma...... irradiation, the water contact angle dropped markedly, and tended to decrease furthermore at higher power. The ultrasonic irradiation during the plasma treatment consistently improved the wettability. Oxygen containing polar functional groups were introduced at the surface by the plasma treatment...

Electrostatic protection of the solar power satellite and rectenna. Part 1: Protection of the solar power satellite

Science.gov (United States)

1980-01-01

Several features of the interactions of the Solar Power Satellite (SPS) with its space environment are examined theoretically. The voltages produced at various surfaces due to space plasmas and the plasma leakage currents through the kapton and sapphire solar cell blankets are calculated. At geosynchronous orbit, this parasitic power loss is only 0.7%, and is easily compensated by oversizing. At low Earth orbit, the power loss is potentially much larger (3%), and anomalous arcing is expected for the EOTV high voltage negative surfaces. Preliminary results of a three dimensional self consistent plasma and electric field computer program are presented, confirming the validity of the predictions made from the one dimensional models. Lastly, magnetic shielding of the satellite is considered to reduce the power drain and to protect the solar cells from energetic electron and plasma ion bombardment. It is concluded that minor modifications can allow the SPS to operate safely and efficiently in its space environment. Subsequent design changes will substantially alter the basic conclusions.

Power oscillation and stability in water cooled reactors

International Nuclear Information System (INIS)

Por, G.; Kis, G.

1998-01-01

Periodic oscillation in measured temperature fluctuation was observed near to surface of a heated rod in certain heat transfer range. The frequency of the peak found in power spectral density of temperature fluctuation and period estimated from the cross correlation function for two axially placed thermocouples change linearly with linear energy (or surface heat) production. It was concluded that a resonance of such surface (inlet) temperature oscillation with the pole of the reactor transfer function can be responsible for power oscillation in BWR and PWR, thus instability is not solely due to reactor transfer function. (author)

Tapping of Love waves in an isotropic surface waveguide by surface-to-bulk wave transduction.

Science.gov (United States)

Tuan, H.-S.; Chang, C.-P.

1972-01-01

A theoretical study of tapping a Love wave in an isotropic microacoustic surface waveguide is given. The surface Love wave is tapped by partial transduction into a bulk wave at a discontinuity. It is shown that, by careful design of the discontinuity, the converted bulk wave power and the radiation pattern may be controlled. General formulas are derived for the calculation of these important characteristics from a relatively general surface contour deformation.

Development of a technoeconomic model

DEFF Research Database (Denmark)

Adjin, Daniel Michael Okwabi; Tadayoni, Reza

2011-01-01

included interviews and surveys-face-to-face discussions and questionnaires. The results show that deployment of intelligent vehicle tracking technology (IVTT) will address the problems of inefficiencies experienced in the Ghanaian road transport haulage tracking industry. Research for ITS development...

Photovoltaic Power System and Power Distribution Demonstration for the Desert RATS Program

Science.gov (United States)

Colozza, Anthony; Jakupca, Ian; Mintz, Toby; Herlacher, Mike; Hussey, Sam

2012-01-01

A stand alone, mobile photovoltaic power system along with a cable deployment system was designed and constructed to take part in the Desert Research And Technology Studies (RATS) lunar surface human interaction evaluation program at Cinder Lake, Arizona. The power system consisted of a photovoltaic array/battery system. It is capable of providing 1 kW of electrical power. The system outputs were 48 V DC, 110 V AC, and 220 V AC. A cable reel with 200 m of power cable was used to provide power from the trailer to a remote location. The cable reel was installed on a small trailer. The reel was powered to provide low to no tension deployment of the cable. The cable was connected to the 220 V AC output of the power system trailer. The power was then converted back to 110 V AC on the cable deployment trailer for use at the remote site. The Scout lunar rover demonstration vehicle was used to tow the cable trailer and deploy the power cable. This deployment was performed under a number of operational scenarios, manned operation, remote operation and tele-robotically. Once deployed, the cable was used to provide power, from the power system trailer, to run various operational tasks at the remote location.

Optimization of the JET Beryllium tile profile for power handling

International Nuclear Information System (INIS)

Nunes, I.; Vries, P. de; Lomas, P.J.; Loarte, A.

2006-01-01

The primary objective of the ITER-like wall project is to install a beryllium main wall and a tungsten divertor. From the point of view of plasma operations, the power handling properties of the new Be tiles may affect the operational space. The tiles design has to be such that it allows routine plasma operation for ITER relevant scenarios, i.e., 3-5 MA ELMy H-modes with high power input (P in > 30 MW) for lengths of time of ∼ 10 s. Due to the constrains imposed by heat conductivity, eddy current and stress torques on a Be tile, a single Be tile must be an assembly of castellated slices [Thompson V. et al, this conference]. From the point of view of plasma operations, the power handling properties of the new Be tiles can restrict the operational space of JET, if considerable melting of the tiles is to be avoided. This paper describes the power handling studies for the beryllium wall tiles and the optimisation of their design to achieve the operation goal described above. The melting temperature for Be is 1289 o C, corresponding to a energy limit of 60 MJ/m 2 for 10 s [Thompson V. et al, this conference]. For low field line angles, the power density on the toroidally facing surfaces is several times higher than the power density on the tile face requiring these to be shadowed. Furthermore the poloidally facing surfaces also have to be shadowed from assembly to assembly due to the large gap between assemblies. The tiles have been designed taking into account these limits and with a geometrical design such as to avoid exposed surfaces at high angles to the magnetic field being melted due to the expected loads. This has been achieved after detailed studies of the power handling of the various limiters and protections, including the effect of the curvature of the flux surfaces, shadowing and tolerance to misalignment. The surface of the tiles is defined such that, when possible, there is an even distribution of power density over the entire tile surface, and that

ZOOPLANKTON COMMUNITY STRUCTURE OF THE SEA SURFACE MICROLAYER NEAR NUCLEAR POWER PLANTS AND MARINE FISH CULTURE ZONES IN DAYA BAY

Institute of Scientific and Technical Information of China (English)

杨宇峰; 王肇鼎; 潘明祥; 焦念志

2002-01-01

The authors' surveys in May-June 1999 (two cruises) at six sampling stations near nuclear power plants (NPP) and marine fish culture zones in Daya Bay, Guangdong, revealed species composition, densities and body-size of thesea surface microlayer (SM) zooplankton (>35 μm). Results showed that protozoans and copepod nauplii were the predominant components, accounting for 65.40% to95.56% of total zooplankton in abundance. The size-frequency distributions showed that the frequency of micro-zooplankton (0.02-0.2 mm) reached 0.8235. The SM zooplankton community structure revealed in the present study was quite different from that revealed by investigations in the 1980s in Daya Bay. Difference of sampling method has important influence on the obtained zooplankton community structure. SM zooplankton consisted of micro- and mesozooplankton (0.2-2.0 mm), with micro-zooplankton being predominant. Some possible cause-effect relations between the zooplankton community structure and mariculture, nuclear power plants cooling systems and sampling method are discussed.``

Design of a powered elevator control system. [powered elevator system for modified C-8A aircraft for STOL operation

Science.gov (United States)

Glende, W. L. B.

1974-01-01

The design, fabrication and flight testing of a powered elevator system for the Augmentor Wing Jet STOL Research Aircraft (AWJSRA or Mod C-8A) are discussed. The system replaces a manual spring tab elevator control system that was unsatisfactory in the STOL flight regime. Pitch control in the AWJSRA is by means of a single elevator control surface. The elevator is used for both maneuver and trim control as the stabilizer is fixed. A fully powered, irreversible flight control system powered by dual hydraulic sources was designed. The existing control columns and single mechanical cable system of the AWJSRA have been retained as has been the basic elevator surface, except that the elevator spring tab is modified into a geared balance tab. The control surface is directly actuated by a dual tandem moving body actuator. Control signals are transmitted from the elevator aft quadrant to the actuator by a linkage system that includes a limited authority series servo actuator.

Power requirements assessment for lunar and Mars scientific and experimental payloads

International Nuclear Information System (INIS)

Kotas, J.F.

1992-01-01

This paper reports on an evaluation of prospective scientific payloads and surface experiments for future manned missions to the moon and Mars which determined that overall mission objectives and requirements influence the selection of candidate power systems. A generic classification of these science missions was developed to examine these relationships. Scientific missions were defined for the four Synthesis Report architectures and cumulative power load and payload mix computed. Approximately half of all deployed science payloads were sited within the main surface outpost and powered by the central power generation facility. The remaining remote science payloads require either autonomous or smaller central power facilities

Planning criteria for open pit mines under special consideration of slope stability and controlled blasting

Energy Technology Data Exchange (ETDEWEB)

Weise, H

1986-04-01

The criteria which influence the economics of a future surface mining operation are discussed; these include the size of the mine and the depth of the deposit. The methods of working are outlined - single bench, multiple bench - and choices of haulage equipment (trucks vs. conveyors) are discussed. For a mine using conveyors, the slope of the open pit will affect the operating cost. Pumps will be required to dewater the strata; it will be necessary to take steps to ensure slope stability. Bucket wheel excavators will be impeded by the presence of consolidated material, which may be best removed by shatter blasting. An example is given of the use of shatter blasting at the Neyveli lignite mine in Tamil Nadu, India. 5 references.

A comparison of radioisotope Brayton and Stirling system for lunar surface mobile power

International Nuclear Information System (INIS)

Harty, R.B.

1991-01-01

A study was performed by the Rocketdyne Division of Rockwell 2.5-kWe modular dynamic isotope power system (DIPS) using a Stirling power conversion system. The results of this study were compared with similar results performed under the DIPS program using a Brayton power conversion system. The study indicated that the Stirling power module has 20% lower mass and 40% lower radiator area than the Brayton module. However, the study also revealed that because the Stirling power module requires a complex heat pipe arrangment to transport heat from the isotope to the Stirling heater head and a pumped NaK heat rejection loop, the Stirling module is much more difficult to integrate with the isotope heat source and heat rejection system

Enhanced Passive Cooling for Waterless-Power Production Technologies

Energy Technology Data Exchange (ETDEWEB)

Rodriguez, Salvador B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2016-06-14

Recent advances in the literature and at SNL indicate the strong potential for passive, specialized surfaces to significantly enhance power production output. Our exploratory computational and experimental research indicates that fractal and swirl surfaces can help enable waterless-power production by increasing the amount of heat transfer and turbulence, when compared with conventional surfaces. Small modular reactors, advanced reactors, and non-nuclear plants (e.g., solar and coal) are ideally suited for sCO2 coolant loops. The sCO2 loop converts the thermal heat into electricity, while the specialized surfaces passively and securely reject the waste process heat in an environmentally benign manner. The resultant, integrated energy systems are highly suitable for small grids, rural areas, and arid regions.

Powering the Space Exploration Initiative

International Nuclear Information System (INIS)

Bennett, G.L.

1991-01-01

The Space Exploration Initiative (SEI) establishes the long-term goal of returning to the Moon and then exploring Mars. One of the prerequisites of SEI is the Exploration Technology Program which includes program elements on space nuclear power and surface solar power. These program elements in turn build upon the ongoing NASA research and technology base program in space energy conversion. There is a wide range of missions in NASA's strategic planning and most would benefit from power sources with improved efficiency, lighter weight and reduced cost

PROBABLE CHARACTERISTICS ОF ELECTROMAGNETIC FIELD ENVIRONMENT AT EARTH SURFACE CAUSED BY RADIO-ELECTRONIC AIDS OPERATING OVER EARTH SURFACE

OpenAIRE

V. I. Mordachev

2009-01-01

The paper provides results of modeling distribution of signal probability of radio-electronic aids located over the Earth surface at a specific height and determining an electromagnetic environment on its surface according to a power parameter and an input direction angle at an optionally selected observation point being on the earth surface.

Laser-powered lunar base

International Nuclear Information System (INIS)

Costen, R.; Humes, D.H.; Walker, G.H.; Williams, M.D.; Deyoung, R.J.

1989-01-01

The objective was to compare a nuclear reactor-driven Sterling engine lunar base power source to a laser-to-electric converter with orbiting laser power station, each providing 1 MW of electricity to the lunar base. The comparison was made on the basis of total mass required in low-Earth-orbit for each system. This total mass includes transportation mass required to place systems in low-lunar orbit or on the lunar surface. The nuclear reactor with Sterling engines is considered the reference mission for lunar base power and is described first. The details of the laser-to-electric converter and mass are discussed. The next two solar-driven high-power laser concepts, the diode array laser or the iodine laser system, are discussed with associated masses in low-lunar-orbit. Finally, the payoff for laser-power beaming is summarized

Holograms for power-efficient excitation of optical surface waves

Science.gov (United States)

Ignatov, Anton I.; Merzlikin, Alexander M.

2018-02-01

A method for effective excitation of optical surface waves based on holography principles has been proposed. For a particular example of excitation of a plasmonic wave in a dielectric layer on metal the efficiency of proposed volume holograms in the dielectric layer has been analyzed in comparison with optimized periodic gratings in the dielectric layer. Conditions when the holograms are considerably more efficient than the gratings have been found out. In addition, holograms recorded in two iterations have been proposed and studied. Such holograms are substantially more efficient than the optimized periodic gratings for all incidence angles of an exciting Gaussian beam. The proposed method is universal: it can be extended for efficient excitation of different types of optical surface waves and optical waveguide modes.

Modeling particle emission and power flow in pulsed-power driven, nonuniform transmission lines

Directory of Open Access Journals (Sweden)

Nichelle Bruner

2008-04-01

Full Text Available Pulsed-power driven x-ray radiographic systems are being developed to operate at higher power in an effort to increase source brightness and penetration power. Essential to the design of these systems is a thorough understanding of electron power flow in the transmission line that couples the pulsed-power driver to the load. In this paper, analytic theory and fully relativistic particle-in-cell simulations are used to model power flow in several experimental transmission-line geometries fielded on Sandia National Laboratories’ upgraded Radiographic Integrated Test Stand [IEEE Trans. Plasma Sci. 28, 1653 (2000ITPSBD0093-381310.1109/27.901250]. Good agreement with measured electrical currents is demonstrated on a shot-by-shot basis for simulations which include detailed models accounting for space-charge-limited electron emission, surface heating, and stimulated particle emission. Resonant cavity modes related to the transmission-line impedance transitions are also shown to be excited by electron power flow. These modes can drive oscillations in the output power of the system, degrading radiographic resolution.

Status of the Development of Low Cost Radiator for Surface Fission Power - II

Science.gov (United States)

Tarau, Calin; Maxwell, Taylor; Anderson, William G.; Wagner, Corey; Wrosch, Matthew; Briggs, Maxwell H.

2016-01-01

NASA Glenn Research Center (GRC) is developing fission power system technology for future Lunar and Martian surface power applications. The systems are envisioned in the 10 to 100kWe range and have an anticipated design life of 8 to 15 years with no maintenance. NASA GRC is currently setting up a 55 kWe non-nuclear system ground test in thermal-vacuum to validate technologies required to transfer reactor heat, convert the heat into electricity, reject waste heat, process the electrical output, and demonstrate overall system performance. The paper reports on the development of the heat pipe radiator to reject the waste heat from the Stirling convertors. Reducing the radiator mass, size, and cost is essential to the success of the program. To meet these goals, Advanced Cooling Technologies, Inc. (ACT) and Vanguard Space Technologies, Inc. (VST) are developing a single facesheet radiator with heat pipes directly bonded to the facesheet. The facesheet material is a graphite fiber reinforced composite (GFRC) and the heat pipes are titanium/water Variable Conductance Heat Pipes (VCHPs). By directly bonding a single facesheet to the heat pipes, several heavy and expensive components can be eliminated from the traditional radiator design such as, POCO"TM" foam saddles, aluminum honeycomb, and a second facesheet. As mentioned in previous papers by the authors, the final design of the waste heat radiator is described as being modular with independent GFRC panels for each heat pipe. The present paper reports on test results for a single radiator module as well as a radiator cluster consisting of eight integral modules. These tests were carried out in both ambient and vacuum conditions. While the vacuum testing of the single radiator module was performed in the ACT's vacuum chamber, the vacuum testing of the eight heat pipe radiator cluster took place in NASA GRC's vacuum chamber to accommodate the larger size of the cluster. The results for both articles show good agreement

Surface morphology of refractive-index waveguide gratings fabricated in polymer films

Science.gov (United States)

Dong, Yi; Song, Yan-fang; Ma, Lei; Gao, Fang-fang

2016-09-01

The characteristic modifications are reported on the surface of polymeric waveguide film in the process of volume- grating fabrication. The light from a mode-locked 76 MHz femtosecond laser with pulse duration of 200 fs and wavelength of 800 nm is focused normal to the surface of the sample. The surface morphology modifications are ascribed to a fact that surface swelling occurs during the process. Periodic micro-structure is inscribed with increasing incident power. The laser-induced swelling threshold on the grating, which is higher than that of two-photon initiated photo-polymerization (TPIP) (8 mW), is verified to be about 20 mW. It is feasible to enhance the surface smoothness of integrated optics devices for further encapsulation. The variation of modulation depth is studied for different values of incident power and scan spacing. Ablation accompanied with surface swelling appears when the power is higher. By optimizing the laser carving parameters, highly efficient grating devices can be fabricated.

PROBABLE CHARACTERISTICS ОF ELECTROMAGNETIC FIELD ENVIRONMENT AT EARTH SURFACE CAUSED BY RADIO-ELECTRONIC AIDS OPERATING OVER EARTH SURFACE

Directory of Open Access Journals (Sweden)

V. I. Mordachev

2009-01-01

Full Text Available The paper provides results of modeling distribution of signal probability of radio-electronic aids located over the Earth surface at a specific height and determining an electromagnetic environment on its surface according to a power parameter and an input direction angle at an optionally selected observation point being on the earth surface.

30 CFR 77.1604 - Transportation of persons; overcrowding.

Science.gov (United States)

2010-07-01

... UNDERGROUND COAL MINES Loading and Haulage § 77.1604 Transportation of persons; overcrowding. (a) No man-trip... other than small handtools shall not be transported with men in man-trip vehicles unless such vehicles are specifically designed to make such transportation safe. ...

Adaptive maximal poisson-disk sampling on surfaces

KAUST Repository

Yan, Dongming; Wonka, Peter

2012-01-01

In this paper, we study the generation of maximal Poisson-disk sets with varying radii on surfaces. Based on the concepts of power diagram and regular triangulation, we present a geometric analysis of gaps in such disk sets on surfaces, which

Lower-extremity resistance training on unstable surfaces improves proxies of muscle strength, power and balance in healthy older adults: a randomised control trial

Directory of Open Access Journals (Sweden)

Nils Eckardt

2016-11-01

Full Text Available Abstract Background It is well documented that both balance and resistance training have the potential to mitigate intrinsic fall risk factors in older adults. However, knowledge about the effects of simultaneously executed balance and resistance training (i.e., resistance training conducted on unstable surfaces [URT] on lower-extremity muscle strength, power and balance in older adults is insufficient. The objective of the present study was to compare the effects of machine-based stable resistance training (M-SRT and two types of URT, i.e., machine-based (M-URT and free-weight URT (F-URT, on measures of lower-extremity muscle strength, power and balance in older adults. Methods Seventy-five healthy community-dwelling older adults aged 65–80 years, were assigned to three intervention groups: M-SRT, M-URT and F-URT. Over a period of ten weeks, all participants exercised two times per week with each session lasting ~60 min. Tests included assessment of leg muscle strength (e.g., maximal isometric leg extension strength, power (e.g., chair rise test and balance (e.g., functional reach test, carried out before and after the training period. Furthermore, maximal training load of the squat-movement was assessed during the last training week. Results Maximal training load of the squat-movement was significantly lower in F-URT in comparison to M-SRT and M-URT. However, lower-extremity resistance training conducted on even and uneven surfaces meaningfully improved proxies of strength, power and balance in all groups. M-URT produced the greatest improvements in leg extension strength and F-URT in the chair rise test and functional reach test. Conclusion Aside from two interaction effects, overall improvements in measures of lower-extremity muscle strength, power and balance were similar across training groups. Importantly, F-URT produced similar results with considerably lower training load as compared to M-SRT and M-URT. Concluding, F-URT seems an

HPDL Remelting of Anodised Al-Si-Cu Cast Alloys Surfaces

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K. Labisz

2012-12-01

Full Text Available The results of the investigations of the laser remelting of the AlSi9Cu4 cast aluminium alloy with the anodised and non-anodised surfacelayer and hardness changes have been presented in this paper. The surface layer of the tested aluminium samples was remelted with thelaser of a continuous work. The power density was from 8,17•103 W/cm2 to 1,63•104 W/cm2. The metallographic tests were conducted inform of light microscope investigations of the received surface layer. The main goal of the investigation was to find the relation betweenthe laser beam power and its power density falling on a material, evaluating the shape and geometry of the remelted layers and theirhardness. As the substrate material two types of surfaces of the casted AlSi9Cu4 alloy were applied – the non–treated as cast surface aswell the anodized surface. As a device for this type of surface laser treatment the High Power Diode Laser was applied with a maximumpower of 2.2 kW and the dimensions of the laser beam focus of 1.8 x 6.8 mm. By mind of such treatment it is also possible to increasehardness as well eliminate porosity and develop metallurgical bonding at the coating-substrate interface. Suitable operating conditions forHPDL laser treatment were finally determined, ranging from 1.0 to 2.0 kW. Under such conditions, taking into account the absorptionvalue, the effects of laser remelting on the surface shape and roughness were studied. The results show that surface roughness is reducedwith increasing laser power by the remelting process only for the non-anodised samples, and high porosity can be found in the with highpower remelted areas. The laser influence increases with the heat input of the laser processing as well with the anodisation of the surface,because of the absorption enhancement ensured through the obtained alumina layer.

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.

Bending and splitting of spoof surface acoustic waves through structured rigid surface

Directory of Open Access Journals (Sweden)

Sujun Xie

2018-03-01

Full Text Available In this paper, we demonstrated that a 90°-bended imaging of spoof surface acoustic waves with subwavelength resolution of 0.316λ can be realized by a 45° prism-shaped surface phononic crystal (SPC, which is composed of borehole arrays with square lattice in a rigid plate. Furthermore, by combining two identical prism-shaped phononic crystal to form an interface (to form a line-defect, the excited spoof surface acoustic waves can be split into bended and transmitted parts. The power ratio between the bended and transmitted surface waves can be tuned arbitrarily by adjusting the defect size. This acoustic system is believed to have potential applications in various multifunctional acoustic solutions integrated by different acoustical devices.

Support surfaces for pressure ulcer prevention: A network meta-analysis

Science.gov (United States)

Dumville, Jo C.; Cullum, Nicky

2018-01-01

Background Pressure ulcers are a prevalent and global issue and support surfaces are widely used for preventing ulceration. However, the diversity of available support surfaces and the lack of direct comparisons in RCTs make decision-making difficult. Objectives To determine, using network meta-analysis, the relative effects of different support surfaces in reducing pressure ulcer incidence and comfort and to rank these support surfaces in order of their effectiveness. Methods We conducted a systematic review, using a literature search up to November 2016, to identify randomised trials comparing support surfaces for pressure ulcer prevention. Two reviewers independently performed study selection, risk of bias assessment and data extraction. We grouped the support surfaces according to their characteristics and formed evidence networks using these groups. We used network meta-analysis to estimate the relative effects and effectiveness ranking of the groups for the outcomes of pressure ulcer incidence and participant comfort. GRADE was used to assess the certainty of evidence. Main results We included 65 studies in the review. The network for assessing pressure ulcer incidence comprised evidence of low or very low certainty for most network contrasts. There was moderate-certainty evidence that powered active air surfaces and powered hybrid air surfaces probably reduce pressure ulcer incidence compared with standard hospital surfaces (risk ratios (RR) 0.42, 95% confidence intervals (CI) 0.29 to 0.63; 0.22, 0.07 to 0.66, respectively). The network for comfort suggested that powered active air-surfaces are probably slightly less comfortable than standard hospital mattresses (RR 0.80, 95% CI 0.69 to 0.94; moderate-certainty evidence). Conclusions This is the first network meta-analysis of the effects of support surfaces for pressure ulcer prevention. Powered active air-surfaces probably reduce pressure ulcer incidence, but are probably less comfortable than standard

Support surfaces for pressure ulcer prevention: A network meta-analysis.

Science.gov (United States)

Shi, Chunhu; Dumville, Jo C; Cullum, Nicky

2018-01-01

Pressure ulcers are a prevalent and global issue and support surfaces are widely used for preventing ulceration. However, the diversity of available support surfaces and the lack of direct comparisons in RCTs make decision-making difficult. To determine, using network meta-analysis, the relative effects of different support surfaces in reducing pressure ulcer incidence and comfort and to rank these support surfaces in order of their effectiveness. We conducted a systematic review, using a literature search up to November 2016, to identify randomised trials comparing support surfaces for pressure ulcer prevention. Two reviewers independently performed study selection, risk of bias assessment and data extraction. We grouped the support surfaces according to their characteristics and formed evidence networks using these groups. We used network meta-analysis to estimate the relative effects and effectiveness ranking of the groups for the outcomes of pressure ulcer incidence and participant comfort. GRADE was used to assess the certainty of evidence. We included 65 studies in the review. The network for assessing pressure ulcer incidence comprised evidence of low or very low certainty for most network contrasts. There was moderate-certainty evidence that powered active air surfaces and powered hybrid air surfaces probably reduce pressure ulcer incidence compared with standard hospital surfaces (risk ratios (RR) 0.42, 95% confidence intervals (CI) 0.29 to 0.63; 0.22, 0.07 to 0.66, respectively). The network for comfort suggested that powered active air-surfaces are probably slightly less comfortable than standard hospital mattresses (RR 0.80, 95% CI 0.69 to 0.94; moderate-certainty evidence). This is the first network meta-analysis of the effects of support surfaces for pressure ulcer prevention. Powered active air-surfaces probably reduce pressure ulcer incidence, but are probably less comfortable than standard hospital surfaces. Most prevention evidence was of low or

Support surfaces for pressure ulcer prevention: A network meta-analysis.

Directory of Open Access Journals (Sweden)

Chunhu Shi

Full Text Available Pressure ulcers are a prevalent and global issue and support surfaces are widely used for preventing ulceration. However, the diversity of available support surfaces and the lack of direct comparisons in RCTs make decision-making difficult.To determine, using network meta-analysis, the relative effects of different support surfaces in reducing pressure ulcer incidence and comfort and to rank these support surfaces in order of their effectiveness.We conducted a systematic review, using a literature search up to November 2016, to identify randomised trials comparing support surfaces for pressure ulcer prevention. Two reviewers independently performed study selection, risk of bias assessment and data extraction. We grouped the support surfaces according to their characteristics and formed evidence networks using these groups. We used network meta-analysis to estimate the relative effects and effectiveness ranking of the groups for the outcomes of pressure ulcer incidence and participant comfort. GRADE was used to assess the certainty of evidence.We included 65 studies in the review. The network for assessing pressure ulcer incidence comprised evidence of low or very low certainty for most network contrasts. There was moderate-certainty evidence that powered active air surfaces and powered hybrid air surfaces probably reduce pressure ulcer incidence compared with standard hospital surfaces (risk ratios (RR 0.42, 95% confidence intervals (CI 0.29 to 0.63; 0.22, 0.07 to 0.66, respectively. The network for comfort suggested that powered active air-surfaces are probably slightly less comfortable than standard hospital mattresses (RR 0.80, 95% CI 0.69 to 0.94; moderate-certainty evidence.This is the first network meta-analysis of the effects of support surfaces for pressure ulcer prevention. Powered active air-surfaces probably reduce pressure ulcer incidence, but are probably less comfortable than standard hospital surfaces. Most prevention evidence was

Estimation of strong motions on free rock surface. Identification of soil structures and strong motions on free rock surface in Kashiwazaki-Kariwa nuclear power plant during the 2007 Niigataken Chuetsu-oki earthquake

International Nuclear Information System (INIS)

Saguchi, Koichiro; Masaki, Kazuaki; Irikura, Kojiro

2009-01-01

Very strong ground motions (maximum acceleration 993 cm/s 2 in the borehole seismometer point of -255m in depth) were observed in the Kashiwazaki Kariwa Nuclear Power Plant during the Niigataken Chuetsu-oki Earthquake on July 16, 2007. In this study, we tried to develop new method, which can simulate waveforms on free rock surface by using the bore hole records. We identified the underground structure model at the Service Hall from aftershock records observed in vertical array, using the simulated annealing method (Ingber(1989)). Based on numerical experiments it is identified that S-wave velocity and Q values of individual layers are inverted very well. Strong motion records of main shock observed by the bore hole seismometers were simulated by using one-dimensional multiple reflection method. In this study, non-linear effect is considered by introducing non-linear coefficient c(f) for under coming wave from surface. The maximum acceleration and phase characteristics in simulated waveforms are similar to the observed one. It means that our method is useful for simulate strong motion in non-linear region. Finally, strong motions on the free rock surface at the Service Hall during the main shock are simulated. The maximum acceleration of EW component on free rock surface is estimated to be 1,207 cm/s 2 . (author)

Role of surface studies in science and technology

Energy Technology Data Exchange (ETDEWEB)

Karkhanavala, M D [Bhabha Atomic Research Centre, Bombay (India). Chemistry Div.

1977-01-01

Reactivity of solids is influenced by the surface properties such as structure, dislocations and composition. Corrosion and erosion are essentially surface phenomena. Surface studies, therefore, assume importance in prevention and minimization of corrosion and erosion. Discussion is illustrated with examples drawn from the field of nuclear power reactor technology.

Role of the carbonate impurities on the surface state of pyrite and arsenopyrite under treatment by high power electromagnetic pulses (HPEMP): oxidation of 50-100 μm size particles

International Nuclear Information System (INIS)

Filippova, I; Filippov, L; Ryazantseva, M; Chanturiya, V; Bunin, I

2013-01-01

Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) and Transmission Electron Microscopy (TEM) have shown the variation of surface phase compositions of carbonate bearing pyrite and arsenopyrite as a result of the combined action of chemical oxidation and thermal processes after the treatment by high power electromagnetic pulses (HPEMP). The monitoring of the surface phase composition allowed to determine the correlation between the treatment conditions, the surface phase composition, and the flotation yield. Thus, HPEMP treatment may be regarded as a tool controlling the surface composition and the sorption ability of flotation collector onto minerals surface, and therefore, allowing to control the hydrophobic-hydrophilic surface balance. It was confirmed in this study that the flotation of pyrite with xanthate as a result of the influence HPEMP may vary depending on the presence of impurities such as calcite.

Solving problems of Eicotrack chainless haulage system

Directory of Open Access Journals (Sweden)

Fries Jiøí

2002-09-01

Full Text Available Téma pøíspìvku „Øešení problémù bezøetìzových pojezdù eicotrackového typu“ vyplynulo z nutnosti øešit zásadní problémy vyskytující se na hlubinných dolech v oblasti samotného dobývání uhlí kombajnovými komplexy. Avizované problémy se týkají zvyšující se èetnosti poruch vrátkové èásti dobývacích kombajnù. Konkrétnì jde o cévové kolo a tra, respektive ozubenice jenž jsou nedílnou souèástí høeblového dopravníku, po kterém kombajn pojíždí. Jedná se o neúmìrné opotøebování obou zmínìných èástí pojezdu, které vedou k jejich destrukci a následnému zastavení dobývání. K tomu se v poslední dobì pøidal stále èastìji objevující se výlom zubu cévového kola a podélná deformace tratì. Prostoje tímto zpùsobené zmenšují efektivnost a produktivitu práce a tím následnì zvyšují náklady na vydobytou tunu uhlí. Tyto problémy, by se bez jejich øešení objevovali stále èastìjší, nebo výrobci dobývacích kombajnù již nyní zahájili výrobu této techniky o vyšším instalovaném výkonu (o 33 %, jenž se pohybuje v oblasti kolem 1000 kW a výše.

Surface properties of magnetite in high temperature aqueous electrolyte solutions: A review.

Science.gov (United States)

Vidojkovic, Sonja M; Rakin, Marko P

2017-07-01

Deposits and scales formed on heat transfer surfaces in power plant water/steam circuits have a significant negative impact on plant reliability, availability and performance, causing tremendous economic consequences and subsequent increases in electricity cost. Consequently, the improvement of the understanding of deposition mechanisms on power generating surfaces is defined as a high priority in the power industry. The deposits consist principally of iron oxides, which are steel corrosion products and usually present in colloidal form. Magnetite (Fe 3 O 4 ) is the predominant and most abundant compound found in water/steam cycles of all types of power plants. The crucial factor that governs the deposition process and influences the deposition rate of magnetite is the electrostatic interaction between the metal wall surfaces and the suspended colloidal particles. However, there is scarcity of data on magnetite surface properties at elevated temperatures due to difficulties in their experimental measurement. In this paper a generalized overview of existing experimental data on surface characteristics of magnetite at high temperatures is presented with particular emphasis on possible application in the power industry. A thorough analysis of experimental techniques, mathematical models and results has been performed and directions for future investigations have been considered. The state-of-the-art assessment showed that for the characterization of magnetite/aqueous electrolyte solution interface at high temperatures acid-base potentiometric titrations and electrophoresis were the most beneficial and dependable techniques which yielded results up to 290 and 200°C, respectively. Mass titrations provided data on magnetite surface charge up to 320°C, however, this technique is highly sensitive to the minor concentrations of impurities present on the surface of particle. Generally, fairly good correlation between the isoelectric point (pH iep ) and point of zero charge

Electrostatic Power Generation from Negatively Charged, Simulated Lunar Regolith

Science.gov (United States)

Choi, Sang H.; King, Glen C.; Kim, Hyun-Jung; Park, Yeonjoon

2010-01-01

Research was conducted to develop an electrostatic power generator for future lunar missions that facilitate the utilization of lunar resources. The lunar surface is known to be negatively charged from the constant bombardment of electrons and protons from the solar wind. The resulting negative electrostatic charge on the dust particles, in the lunar vacuum, causes them to repel each other minimizing the potential. The result is a layer of suspended dust about one meter above the lunar surface. This phenomenon was observed by both Clementine and Surveyor spacecrafts. During the Apollo 17 lunar landing, the charged dust was a major hindrance, as it was attracted to the astronauts' spacesuits, equipment, and the lunar buggies. The dust accumulated on the spacesuits caused reduced visibility for the astronauts, and was unavoidably transported inside the spacecraft where it caused breathing irritation [1]. In the lunar vacuum, the maximum charge on the particles can be extremely high. An article in the journal "Nature", titled "Moon too static for astronauts?" (Feb 2, 2007) estimates that the lunar surface is charged with up to several thousand volts [2]. The electrostatic power generator was devised to alleviate the hazardous effects of negatively charged lunar soil by neutralizing the charged particles through capacitive coupling and thereby simultaneously harnessing power through electric charging [3]. The amount of power generated or collected is dependent on the areal coverage of the device and hovering speed over the lunar soil surface. A thin-film array of capacitors can be continuously charged and sequentially discharged using a time-differentiated trigger discharge process to produce a pulse train of discharge for DC mode output. By controlling the pulse interval, the DC mode power can be modulated for powering devices and equipment. In conjunction with a power storage system, the electrostatic power generator can be a power source for a lunar rover or other

Reactive-ion etching of nylon fabric meshes using oxygen plasma for creating surface nanostructures

International Nuclear Information System (INIS)

Salapare, Hernando S.; Darmanin, Thierry; Guittard, Frédéric

2015-01-01

Graphical abstract: - Highlights: • Reactive-ion etching (RIE) is employed to nylon 6,6 fabrics to achieve surface texturing and improved wettability. • FTIR spectra of the treated samples exhibited decreased transmittance of amide and carboxylic acid groups due to etching. • Etching is enhanced for higher power plasma treatments and for samples with larger mesh sizes. • Decreased crystallinity was achieved after plasma treatment. • Higher power induced higher negative DC self-bias voltage on the samples that favored anisotropic and aggressive etching. - Abstract: A facile one-step oxygen plasma irradiation in reactive ion etching (RIE) configuration is employed to nylon 6,6 fabrics with different mesh sizes to achieve surface nanostructures and improved wettability for textile and filtration applications. To observe the effects of power and irradiation time on the samples, the experiments were performed using constant irradiation time in varying power and using constant power in varying irradiation times. Results showed improved wettability after the plasma treatment. The FTIR spectra of all the treated samples exhibited decreased transmittance of the amide and carboxylic acid groups due to surface etching. The changes in the surface chemistry are supported by the SEM data wherein etching and surface nanostructures were observed for the plasma-treated samples. The etching of the surfaces is enhanced for higher power plasma treatments. The thermal analysis showed that the plasma treatment resulted in decreased crystallinity. Surface chemistry showed that the effects of the plasma treatment on the samples have no significant difference for all the mesh sizes. However, surface morphology showed that the sizes of the surface cracks are the same for all the mesh sizes but samples with larger mesh sizes exhibited enhanced etching as compared to the samples with smaller mesh sizes. Higher power induced higher negative DC self-bias voltage on the samples that

Remote Monitoring of Near-Surface Soil Moisture Dynamics In Unstable Slopes Using a Low-Power Autonomous Resistivity Imaging System

Science.gov (United States)

Chambers, J. E.; Meldrum, P.; Gunn, D.; Wilkinson, P. B.; Uhlemann, S.; Swift, R. T.; Kuras, O.; Inauen, C.; Hutchinson, D.; Butler, S.

2016-12-01

ERT monitoring has been demonstrated in numerous studies as an effective means of imaging near surface processes for applications as diverse as permafrost studies and contaminated land assessment. A limiting factor in applying time-lapse ERT for long-term studies in remote locations has been the availability of cost-effective ERT measurement systems designed specifically for monitoring applications. Typically, monitoring is undertaken using repeated manual data collection, or by building conventional survey instruments into a monitoring setup. The latter often requires high power and is therefore difficult to operate remotely without access to mains electricity. We describe the development of a low-power resistivity imaging system designed specifically for remote monitoring, taking advantage of, e.g., solar power and data telemetry. Here, we present the results of two field deployments. The system has been installed on an active railway cutting to provide insights into the effect of vegetation on the moisture dynamics in unstable infrastructure slopes and to gather subsurface information for pro-active remediation measures. The system, comprising 255 electrodes, acquires 4596 reciprocal measurement pairs twice daily during standard operation. In case of severe weather events, the measurement schedule is reactively changed, to gather high temporal resolution data to image rainfall infiltration processes. The system has also been installed along a leaking and marginally stable canal embankment; a less favourable location for remote monitoring, with limited solar power and poor mobile reception. Nevertheless, the acquired data indicated the effectiveness of remedial actions on the canal. The ERT results showed that one leak was caused by the canal and fixed during remediation, while two other "leaks" were shown to be effects of groundwater dynamics. The availability of cost-effective, low-power ERT monitoring instrumentation, combined with an automated workflow of

Stretched exponentials and power laws in granular avalanching

Science.gov (United States)

Head, D. A.; Rodgers, G. J.

1999-02-01

We introduce a model for granular surface flow which exhibits both stretched exponential and power law avalanching over its parameter range. Two modes of transport are incorporated, a rolling layer consisting of individual particles and the overdamped, sliding motion of particle clusters. The crossover in behaviour observed in experiments on piles of rice is attributed to a change in the dominant mode of transport. We predict that power law avalanching will be observed whenever surface flow is dominated by clustered motion.

Surface improvement for inside surface of small diameter pipes by laser cladding technique

International Nuclear Information System (INIS)

Irisawa, Toshio; Morishige, Norio; Umemoto, Tadahiro; Ono, Kazumichi; Hamaoka, Tadashi; Tanaka, Atsushi

1991-01-01

A laser cladding technique has been used for surface improvement in controlling the composition of a metal surface. Recent high power YAG laser development gives an opportunity to use this laser cladding technique for various applications. A YAG laser beam can be transmitted through an optical fiber for a long distance and through narrow spaces. YAG laser cladding was studied for developing alloy steel to prevent stress corrosion cracking in austenitic stainless steel piping. In order to make a cladding layer, mixed metal powder was on the inside surface of the piping using an organic binder. Subsequently the powder beds were melted with a YAG laser beam transmitted through an optical fiber. This paper introduces the Laser cladding technique for surface improvement for the inside surface of a small diameter pipe. (author)

Performance analysis of PV panel under varying surface temperature

Directory of Open Access Journals (Sweden)

Kumar Tripathi Abhishek

2018-01-01

Full Text Available The surface temperature of PV panel has an adverse impact on its performance. The several electrical parameters of PV panel, such as open circuit voltage, short circuit current, power output and fill factor depends on the surface temperature of PV panel. In the present study, an experimental work was carried out to investigate the influence of PV panel surface temperature on its electrical parameters. The results obtained from this experimental study show a significant reduction in the performance of PV panel with an increase in panel surface temperature. A 5W PV panel experienced a 0.4% decrease in open circuit voltage for every 1°C increase in panel surface temperature. Similarly, there was 0.6% and 0.32% decrease in maximum power output and in fill factor, respectively, for every 1°C increase in panel surface temperature. On the other hand, the short circuit current increases with the increase in surface temperature at the rate of 0.09%/°C.

Standard criteria for disposal of liquid radioactive wastes from nuclear power plants into surface waters (river systems)

International Nuclear Information System (INIS)

Pisarev, V.V.; Tsybizov, I.S.

1976-01-01

Radioactive products discharge into natural water streams results in the necessity to regulate nuclear power plant discharges to ensure radiation safety (RS) for population using a river and surrounding river territory. To ensure RS it is necessary to set scientific-founded standards of permissible discharge level of liquid radioactive wastes (LRW) from nuclear power plant assuring observance of hygienic requirements for surface water puring. Volume of permissible LRW discharge into river systems must be set both with provision for concrete physical-geographycal conditions, specficity of utilizing the river and river valley and social-economical peculiarities of crtical population groups. The value of permissible LRW discharge into river systems is determined by three criterion groups: radiological, ecological and hydrological ones. By means of radiological group the internal and external irradiation doses for the whole body and its separate organs are set and RS of population is determined. Ecological criteria include a number of parameters (coefficients of accumulation, distribution and transition) determining quantitative ratios between radioactive element contents in water and separate links of biological chains: soil/water, fish/water, vegetables/water and others. Hydrological criteria determine the degree of waste dilution in rivers, control radioactive contamination of flood-lands areas and in common with ecological criteria determine radionuclide contents in soil and food products. A method of determining average annual values of LRW dilution in river waters is presented [ru

Plasma-surface interactions under high heat and particle fluxes

NARCIS (Netherlands)

De Temmerman, G.; Bystrov, K.; Liu, F.; Liu, W.; Morgan, T.; Tanyeli, I.; van den Berg, M.; Xu, H.; Zielinski, J.

2013-01-01

The plasma-surface interactions expected in the divertor of a future fusion reactor are characterized by extreme heat and particle fluxes interacting with the plasma-facing surfaces. Powerful linear plasma generators are used to reproduce the expected plasma conditions and allow plasma-surface

Decontamination and radioactivity measurement on building surfaces related to dismantling of Japan power demonstration reactor (JPDR)

International Nuclear Information System (INIS)

Hatakeyama, Mutsuo; Tachibana, Mitsuo; Yanagihara, Satoshi

1997-12-01

In the final stage of dismantling activities for decommissioning a nuclear power plant, building structures have to be demolished to release the site for unrestricted use. Since building structures are generally made from massive reinforced concrete materials, it is not a rational way to treat all concrete materials arising from its demolition as radioactive waste. Segregation of radioactive parts from building structures is therefore indispensable. The rational procedures were studied for demolition of building structures by treating arising waste as non-radioactive materials, based on the concept established by Nuclear Safety Commission, then these were implemented in the following way by the JPDR dismantling demonstration project. Areas of the JPDR facilities are categorized into two groups : possibly contaminated areas, and possibly non-contaminated areas, based on the document of the reactor operation. Radioactivity on the building surfaces was then measured to confirm that the qualitative categorization is reasonable. After that, building surfaces were decontaminated in such a way that the contaminated layers were removed with enough margin to separate radioactive parts from non-radioactive building structures. Thought it might be possible to demolish the building structures by treating arising waste as non-radioactive materials, confirmation survey for radioactivity was conducted to show that there is no artificial radioactive nuclides produced by operation in the facility. This report describes the procedures studied on measurement of radioactivity and decontamination, and the results of its implementation in the JPDR dismantling demonstration project. (author)

30 CFR 48.27 - Training of miners assigned to a task in which they have had no previous experience; minimum...

Science.gov (United States)

2010-07-01

..., drilling machine operators, haulage and conveyor systems operators, ground control machine operators, AMS operators, and those in blasting operations shall not perform new work tasks in these categories until... equipment or machine or engage in blasting operations without direction and immediate supervision until such...

DETERMINATION OF RADIATOR COOLING SURFACE

Directory of Open Access Journals (Sweden)

A. I. Yakubovich

2009-01-01

Full Text Available The paper proposes a methodology for calculation of a radiator cooling surface with due account of heat transfer non-uniformity on depth of its core. Calculation of radiator cooling surfaces of «Belarus-1221» and «Belarus-3022» tractors has been carried out in the paper. The paper also advances standard size series of radiators for powerful «Belarus» tractor type.

High RF Power Production for CLIC

CERN Document Server

Syratchev, I; Adli, E; Taborelli, M

2007-01-01

The CLIC Power Extraction and Transfer Structure (PETS) is a passive microwave device in which bunches of the drive beam interact with the impedance of the periodically loaded waveguide and excite preferentially the synchronous mode. The RF power produced (several hundred MW) is collected at the downstream end of the structure by means of the Power Extractor and delivered to the main linac structure. The PETS geometry is a result of multiple compromises between beam stability and main linac RF power needs. Another requirement is to provide local RF power termination in case of accelerating structure failure (ON/OFF capability). Surface electric and magnetic fields, power extraction method, HOM damping, ON/OFF capability and fabrication technology were all evaluated to provide a reliable design

An experimental method for making spectral emittance and surface temperature measurements of opaque surfaces

International Nuclear Information System (INIS)

Moore, Travis J.; Jones, Matthew R.; Tree, Dale R.; Daniel Maynes, R.; Baxter, Larry L.

2011-01-01

An experimental procedure has been developed to make spectral emittance and temperature measurements. The spectral emittance of an object is calculated using measurements of the spectral emissive power and of the surface temperature of the object obtained using a Fourier transform infrared (FTIR) spectrometer. A calibration procedure is described in detail which accounts for the temperature dependence of the detector. The methods used to extract the spectral emissive power and surface temperature from measured infrared spectra were validated using a blackbody radiator at known temperatures. The average error in the measured spectral emittance was 2.1% and the average difference between the temperature inferred from the recorded spectra and the temperature indicated on the blackbody radiator was 1.2%. The method was used to measure the spectral emittance of oxidized copper at various temperatures.

Surface Modification of Polymeric Materials by Plasma Treatment

Directory of Open Access Journals (Sweden)

E.F. Castro Vidaurre

2002-03-01

Full Text Available Low-temperature plasma treatment has been used in the last years as a useful tool to modify the surface properties of different materials, in special of polymers. In the present work low temperature plasma was used to treat the surface of asymmetric porous substrates of polysulfone (PSf membranes. The main purpose of this work was to study the influence of the exposure time and the power supplied to argon plasma on the permeability properties of the membranes. Three rf power levels, respectively 5, 10 and 15 W were used. Treatment time ranged from 1 to 50 min. Reduction of single gas permeability was observed with Ar plasma treatments at low energy bombardment (5 W and short exposure time (20 min. Higher power and/or higher plasma exposition time causes a degradation process begins. The chemical and structural characterization of the membranes before and after the surface modification was done by AFM, SEM and XPS.

Summary of the Manufacture, Testing and Model Validation of a Full-Scale Radiator for Fission Surface Power Applications

Science.gov (United States)

Ellis, David L.; Calder, James; Siamidis, John

2011-01-01

A full-scale radiator for a lunar fission surface power application was manufactured by Material innovations, Inc., for the NASA Glenn Research Center. The radiator was designed to reject 6 kWt with an inlet water temperature of 400 K and a water mass flow rate of 0.5 kg/s. While not flight hardware, the radiator incorporated many potential design features and manufacturing techniques for future flight hardware. The radiator was tested at NASA Glenn Research Center for heat rejection performance. The results showed that the radiator design was capable of rejecting over 6 kWt when operating at the design conditions. The actual performance of the radiator as a function of operational manifolds, inlet water temperature and facility sink temperature was compared to the predictive model developed by NASA Glenn Research Center. The results showed excellent agreement with the model with the actual average face sheet temperature being within 1% of the predicted value. The results will be used in the design and production of NASA s next generation fission power heat rejection systems. The NASA Glenn Research Center s Technology Demonstration Unit will be the first project to take advantage of the newly developed manufacturing techniques and analytical models.

Development of radioactive surface contamination monitor

International Nuclear Information System (INIS)

Hashimoto, Tadao; Hasegawa, Toru; Fukumoto, Keisuke; Ooki, Yasushi

2008-01-01

In the radiation facilities such as nuclear power plants, surface contamination of the people accessing or articles conveyed in and out of the radiation controlled areas is detected and monitored by installing contamination monitors at the boundary of controlled areas and uncontrolled areas against the expansion of the radioactive materials to out of the facilities. It is required for the surface contamination of articles to be tightened of control criteria as 'Guidelines for discrimination ways of nonradioactive waste (not classified as radioactive waste) generated from nuclear power plants' (hereinafter referred to as 'the Guideline') was established by the Nuclear and Industrial Safety Agency of the Ministry of Economy, Trade and Industry in August, 2005. It predicts that the control criteria of monitors other than article monitors are also tightened in the future. Fuji electric has been fabricating and delivering surface contamination detecting monitors. Now we are developing the new contamination monitor corresponding to the tightening of the control criteria. 'Large article transfer monitor', 'Clothing monitor' and 'Body surface contamination monitor' are introduced in this article. (author)

Gravity Scaling of a Power Reactor Water Shield

International Nuclear Information System (INIS)

Reid, Robert S.; Pearson, J. Boise

2008-01-01

Water based reactor shielding is being considered as an affordable option for potential use on initial lunar surface reactor power systems. Heat dissipation in the shield from nuclear sources must be rejected by an auxillary thermal hydraulic cooling system. The mechanism for transferring heat through the shield is natural convection between the core surface and an array of thermosyphon radiator elements. Natural convection in a 100 kWt lunar surface reactor shield design has been previously evaluated at lower power levels (Pearson, 2006). The current baseline assumes that 5.5 kW are dissipated in the water shield, the preponderance on the core surface, but with some volumetric heating in the naturally circulating water as well. This power is rejected by a radiator located above the shield with a surface temperature of 370 K. A similarity analysis on a water-based reactor shield is presented examining the effect of gravity on free convection between a radiation shield inner vessel and a radiation shield outer vessel boundaries. Two approaches established similarity: 1) direct scaling of Rayleigh number equates gravity-surface heat flux products, 2) temperature difference between the wall and thermal boundary layer held constant on Earth and the Moon. Nussult number for natural convection (laminar and turbulent) is assumed of form Nu = CRa n . These combined results estimate similarity conditions under Earth and Lunar gravities. The influence of reduced gravity on the performance of thermosyphon heat pipes is also examined

Maryland power plants and the environment: A review of the impacts of power plants and transmission lines on Maryland's natural resources. Biannually report

International Nuclear Information System (INIS)

1993-03-01

The report, published biannually by Maryland's Power Plant Research Program, is a summary of current information related to environmental impacts associated with electric power generation in Maryland. Topics discussed in detail include: Power Supply and Demand; Air Quality; Surface and Groundwater Impacts; Terrestrial Impacts; Radiological Impacts; and Acid Deposition

Rotary-Atomizer Electric Power Generator

Science.gov (United States)

Nguyen, Trieu; Tran, Tuan; de Boer, Hans; van den Berg, Albert; Eijkel, Jan C. T.

2015-03-01

We report experimental and theoretical results on a ballistic energy-conversion method based on a rotary atomizer working with a droplet acceleration-deceleration cycle. In a rotary atomizer, liquid is fed onto the center of a rotating flat surface, where it spreads out under the action of the centrifugal force and creates "atomized" droplets at its edge. The advantage of using a rotary atomizer is that the centrifugal force exerted on the fluid on a smooth, large surface is not only a robust form of acceleration, as it avoids clogging, but also easily allows high throughput, and produces high electrical power. We successfully demonstrate an output power of 4.9 mW and a high voltage up to 3120 V. At present, the efficiency of the system is still low (0.14%). However, the conversion mechanism of the system is fully interpreted in this paper, permitting a conceptual understanding of system operation and providing a roadmap for system optimization. This observation will open up a road for building power-generation systems in the near future.

SRF Cavity Surface Topography Characterization Using Replica Techniques

Energy Technology Data Exchange (ETDEWEB)

C. Xu, M.J. Kelley, C.E. Reece

2012-07-01

To better understand the roll of topography on SRF cavity performance, we seek to obtain detailed topographic information from the curved practical cavity surfaces. Replicas taken from a cavity interior surface provide internal surface molds for fine Atomic Force Microscopy (AFM) and stylus profilometry. In this study, we confirm the replica resolution both on surface local defects such as grain boundary and etching pits and compare the surface uniform roughness with the aid of Power Spectral Density (PSD) where we can statistically obtain roughness parameters at different scales. A series of sampling locations are at the same magnetic field chosen at the same latitude on a single cell cavity to confirm the uniformity. Another series of sampling locations at different magnetic field amplitudes are chosen for this replica on the same cavity for later power loss calculation. We also show that application of the replica followed by rinsing does not adversely affect the cavity performance.

Improved control system power unit for large parachutes

Science.gov (United States)

Chandler, J. A.; Grubbs, T. M.

1968-01-01

Improved control system power unit drives the control surfaces of very large controllable parachutes. The design features subassemblies for determining control surface position and cable loading, and protection of the load sensor against the possibility of damage during manipulation.

Ultrasound pulse-echo measurements on rough surfaces with linear array transducers

DEFF Research Database (Denmark)

Sjøj, Sidsel M. N.; Blanco, Esther N.; Wilhjelm, Jens E.

2012-01-01

The echo from planar surfaces with rms roughness, Rq, in the range from 0-155 μm was measured with a clinical linear array transducer at different angles of incidence at 6 MHz and 12 MHz. The echo-pulse from the surfaces was isolated with an equal sized window and the power of the echo-pulse was ......The echo from planar surfaces with rms roughness, Rq, in the range from 0-155 μm was measured with a clinical linear array transducer at different angles of incidence at 6 MHz and 12 MHz. The echo-pulse from the surfaces was isolated with an equal sized window and the power of the echo......-pulse was calculated. The power of the echo from the smooth surface (Rq = 0) is highly angle-dependent due to a high degree of specular reflection. Within the angular range considered here, -10° to 10°, the variation spans a range of 18 dB at both 6 MHz and 12 MHz. When roughness increases, the angle......-dependence decreases, as the echo process gradually changes from pure reflection to being predominantly governed by backscattering. The power of the echoes from the two roughest surfaces (Rq = 115 μm and 155 μm) are largely independent of angle at both 6 MHz and 12 MHz with a variation of 2 dB in the angular range...

Wireless transmission of power

International Nuclear Information System (INIS)

Grotz, T.

1991-01-01

This paper reports that it has been proven by researchers that electrical energy can be propagated around the world between the surface of the Earth and the ionosphere at extremely low frequencies in what is known as the Schumann Cavity. Experiments to data have shown that electromagnetic waves with frequencies in the range of 8 Hz, the fundamental Schumann Resonance frequency, propagate with litter attenuation around the planet within the Schumann Cavity. It is the intent of this research to determine if the Schumann Cavity can be resonated, if the power that is delivered to the cavity propagated with very low losses, and if power can be extracted at other locations within the cavity. Experimental data collected and calculations made in recent years support the hypothesis that wireless power transmission is a viable and practical alternative to the present systems of power transmission

Power output and efficiency of a thermoelectric generator under temperature control

International Nuclear Information System (INIS)

Chen, Wei-Hsin; Wu, Po-Hua; Wang, Xiao-Dong; Lin, Yu-Li

2016-01-01

Highlights: • Power output and efficiency of a thermoelectric generator (TEG) is studied. • Temperatures at the module’s surfaces are approximated by sinusoidal functions. • Mean output power and efficiency are enhanced by the temperature oscillation. • The maximum mean efficiency of the TEG in this study is 8.45%. • The phase angle of 180° is a feasible operation for maximizing the performance. - Abstract: Operation control is an effective way to improve the output power of thermoelectric generators (TEGs). The present study is intended to numerically investigate the power output and efficiency of a TEG and find the operating conditions for maximizing its performance. The temperature distributions at the hot side and cold side surfaces of the TEG are approximated by sinusoidal functions. The influences of the temperature amplitudes at the hot side surface and the cold side surface, the phase angle, and the figure-of-merit (ZT) on the performance of the TEG are analyzed. The predictions indicate that the mean output power and efficiency of the TEG are significantly enhanced by the temperature oscillation, whereas the mean absorbed heat by the TEG is slightly influenced. An increase in the temperature amplitude of the hot side surface and the phase angle can effectively improve the performance. For the phase angle of 0°, a smaller temperature amplitude at the cold side surface renders the better performance compared to that with a larger amplitude. When the ZT value increases from 0.736 to 1.8, the mean efficiency at the phase angle of 180° is amplified by a factor of 1.72, and the maximum mean efficiency is 8.45%. In summary, a larger temperature amplitude at the hot side surface with the phase angle of 180° is a feasible operation for maximizing the performance.

Surface treatment of dental implants with high- power pulsed ion beams

International Nuclear Information System (INIS)

Shulov, V.A.; Nochovnaya, N.A.; Remnev, G.E.; Ivanov, S.Y.; Lomakin, M.V.

2001-01-01

The objective of the present research is development of HPPIB technology for surface processing of compact components with a complex shape. The surface state of the dental implants from titanium alloys before and after irradiation and long time operation was investigated by Auger electron spectroscopy, scanning electron microscopy, X-ray structural analysis, optical metallography methods. It is shown that the homogeneous state in the surface layer of titanium alloys is formed due to the irradiation (carbon ions and protons, energy of ions is equal to 300 keV, density of ion energy in a pulse achieves 1-5 J/cm 2 ). This state is characterized by a low amount of the impurities and a fine dispersion structure formed as a result of high speed crystallization. Thus, HPPIB irradiation of the dental implants leads to formation of developed micro relief and the decrease of impurities content on the surface. As a result, this treatment allows one to achieve a good cohesion between the implants and a body tissue. The latter allows the conclusion that biocompatibility of the dental titanium implants produced by can be improved using HPPIB treatment

Experimental Verification of a Pneumatic Transport System for the Rapid Evacuation of Tunnels, Part II - Test Program

Science.gov (United States)

1978-12-01

This study is the final phase of a muck pipeline program begun in 1973. The objective of the study was to evaluate a pneumatic pipeline system for muck haulage from a tunnel excavated by a tunnel boring machine. The system was comprised of a muck pre...

30 CFR 48.7 - Training of miners assigned to a task in which they have had no previous experience; minimum...

Science.gov (United States)

2010-07-01

... to new work tasks as mobile equipment operators, drilling machine operators, haulage and conveyor systems operators, roof and ground control machine operators, and those in blasting operations shall not... paragraph (a) of this section shall not operate the equipment or machine or engage in blasting operations...

Effects of surface shape on the geometry and surface topography of the melt pool in low-power density laser melting

KAUST Repository

Kim, Youngdeuk

2011-04-15

The quantitative correlations between workpiece volume and melt pool geometry, as well as the flow and thermal features of the melt pool are established. Thermocapillary convections in melt pool with a deformable free surface are investigated with respect to surface shape and laser intensity. When the contact angle between the tangent to the top surface and the vertical wall at the hot center is acute, the free surface flattens, compared with that of the initial free surface. Otherwise, the free surface forms a bowl-like shape with a deep crater and a low peripheral rim when the contact angle at the hot center is obtuse. Increasing the workpiece volume at a fixed laser intensity and a negative radial height gradient cause linear decreases in the geometric size and magnitude of flow and temperature of the melt pool. Conversely, linear increases are observed with a positive radial height gradient. © 2011 American Institute of Chemical Engineers (AIChE).

Thermomechanical modelling of laser surface glazing for H13 tool steel

Science.gov (United States)

Kabir, I. R.; Yin, D.; Tamanna, N.; Naher, S.

2018-03-01

A two-dimensional thermomechanical finite element (FE) model of laser surface glazing (LSG) has been developed for H13 tool steel. The direct coupling technique of ANSYS 17.2 (APDL) has been utilised to solve the transient thermomechanical process. A H13 tool steel cylindrical cross-section has been modelled for laser power 200 W and 300 W at constant 0.2 mm beam width and 0.15 ms residence time. The model can predict temperature distribution, stress-strain increments in elastic and plastic region with time and space. The crack formation tendency also can be assumed by analysing the von Mises stress in the heat-concentrated zone. Isotropic and kinematic hardening models have been applied separately to predict the after-yield phenomena. At 200 W laser power, the peak surface temperature achieved is 1520 K which is below the melting point (1727 K) of H13 tool steel. For laser power 300 W, the peak surface temperature is 2523 K. Tensile residual stresses on surface have been found after cooling, which are in agreement with literature. Isotropic model shows higher residual stress that increases with laser power. Conversely, kinematic model gives lower residual stress which decreases with laser power. Therefore, both plasticity models could work in LSG for H13 tool steel.

The influence of surface chemistry and size of nanoscale graphene oxide on photothermal therapy of cancer using ultra-low laser power.

Science.gov (United States)

Yang, Kai; Wan, Jianmei; Zhang, Shuai; Tian, Bo; Zhang, Youjiu; Liu, Zhuang

2012-03-01

Photothermal therapy as a physical treatment approach to destruct cancer has emerged as an alternative of currently used cancer therapies. Previously we have shown that polyethylene glycol (PEG) functionalized nano-graphene oxide (nGO-PEG) with strong optical absorption in the near-infrared (NIR) region was a powerful photothermal agent for in vivo cancer treatment. In this work, by using ultra-small reduced graphene oxide (nRGO) with non-covalent PEG coating, we study how sizes and surface chemistry affect the in vivo behaviors of graphene, and remarkably improve the performance of graphene-based in vivo photothermal cancer treatment. Owing to the enhanced NIR absorbance and highly efficient tumor passive targeting of nRGO-PEG, excellent in vivo treatment efficacy with 100% of tumor elimination is observed after intravenous injection of nRGO-PEG and the followed 808 nm laser irradiation, the power density (0.15 W/cm(2), 5 min) of which is an order of magnitude lower than that usually applied for in vivo tumor ablation using many other nanomaterials. All mice after treatment survive over a period of 100 days without a single death or any obvious sign of side effect. Our results highlight that both surface chemistry and sizes are critical to the in vivo performance of graphene, and show the promise of using optimized nano-graphene for ultra-effective photothermal treatment, which may potentially be combined with other therapeutic approaches to assist our fight against cancer. Copyright © 2011 Elsevier Ltd. All rights reserved.

Small surface wave discharge at atmospheric pressure

Energy Technology Data Exchange (ETDEWEB)

Kiss' ovski, Zh; Kolev, M; Ivanov, A; Lishev, St; Koleva, I, E-mail: kissov@phys.uni-sofia.b [Faculty of Physics, Sofia University, BG-1164 Sofia (Bulgaria)

2009-09-21

A small surface wave driven source produces plasma at atmospheric pressure. Microwave power at frequency 2.45 GHz is coupled with the source and a discharge is ignited at power levels below 10 W. The coaxial exciter of the surface waves has a length of 10 mm because its dielectric is a high permittivity discharge tube. The plasma source operates as a plasma jet in the case of plasma columns longer than the tube length. The source maintains stable plasma columns over a wide range of neutral gas flow and applied power in continuous and pulse regimes. An additional advantage of this source is the discharge self-ignition. An electron temperature of T{sub e} {approx} 1.9 eV and a density of n{sub e} {approx} 3.9 x 10{sup 14} cm{sup -3} are estimated by the probe diagnostics method. The emission spectra in the wavelength range 200-1000 nm under different experimental conditions are analysed and they prove the applicability of the source for analytical spectroscopy. The dependences of column length, reflected power and plasma parameters on the gas flow and the input power are discussed. (fast track communication)

Surface treatment of diamond-like carbon films by reactive Ar/CF{sub 4} high-power pulsed magnetron sputtering plasmas

Energy Technology Data Exchange (ETDEWEB)

Kimura, Takashi, E-mail: t-kimura@nitech.ac.jp [Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan); Nishimura, Ryotaro [Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan); Azuma, Kingo [Department of Electrical Engineering and Computer Sciences, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671-2280 (Japan); Nakao, Setsuo; Sonoda, Tsutomu; Kusumori, Takeshi; Ozaki, Kimihiro [National Institute of Advanced Industrial Science and Technology (AIST) - Chubu, 2266-98 Anagahora, Moriyama, Nagoya 463-8560 (Japan)

2015-12-15

Surface modification of diamond-like carbon films deposited by a high-power pulsed magnetron sputtering (HPPMS) of Ar was carried out by a HPPMS of Ar/CF{sub 4} mixture, changing a CF{sub 4} fraction from 2.5% to 20%. The hardness of the modified films markedly decreased from about 13 to about 3.5 GPa with increasing CF{sub 4} fraction, whereas the water contact angle of the modified films increased from 68° to 109° owing to the increase in the CF{sub x} content on the film surface. C 1s spectra in X-ray photoelectron spectroscopy indicated that a graphitic structure of modified films was formed at CF{sub 4} fractions less than 5%, above which the modified films possessed a polymer-like structure. Influence of treatment time on the properties of the modified films was also investigated in the range of treatment time from 5 to 30 min. The properties of the modified films did not depend on the treatment time in the range of treatment time longer than 10 min, whereas the water contact angle was not sensitive to the treatment time at any treatment time.

Low Cost Radiator for Fission Power Thermal Control, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — NASA Glenn Research Center (GRC) is developing fission power system technology for future space transportation and surface power applications. The early systems are...

In-volume heating using high-power laser diodes

NARCIS (Netherlands)

Denisenkov, V.S.; Kiyko, V.V.; Vdovin, G.V.

2015-01-01

High-power lasers are useful instruments suitable for applications in various fields; the most common industrial applications include cutting and welding. We propose a new application of high-power laser diodes as in-bulk heating source for food industry. Current heating processes use surface

Pelletised fuel production from coal tailings and spent mushroom compost - Part II. Economic feasibility based on cost analysis

International Nuclear Information System (INIS)

Ryu, Changkook; Khor, Adela; Sharifi, Vida N.; Swithenbank, Jim

2008-01-01

Due to the growing market for sustainable energy, in order to increase the quality of the fuels, pellets are being produced from various materials such as wood and other biomass energy crops, and municipal waste. This paper presents the results from an economic feasibility study for pellet production using blends of two residue materials: coal tailings from coal cleaning and spent mushroom compost (SMC) from mushroom production. Key variables such as the mixture composition, raw material haulage and plant scale were considered and the production costs were compared to coal and biomass energy prices. For both wet materials, the moisture content was the critical parameter that influenced the fuel energy costs. The haulage distance of the raw materials was another factor that can pose a high risk. The results showed that the pellet production from the above two materials can be viable when a less energy-intensive drying process is utilised. Potential market outlets and ways to lower the costs are also discussed in this paper. (author)

Dynamics of gas-surface interactions atomic-level understanding of scattering processes at surfaces

CERN Document Server

Díez Muniño, Ricardo

2013-01-01

This book gives a representative survey of the state of the art of research on gas-surface interactions. It provides an overview of the current understanding of gas surface dynamics and, in particular, of the reactive and non-reactive processes of atoms and small molecules at surfaces. Leading scientists in the field, both from the theoretical and the experimental sides, write in this book about their most recent advances. Surface science grew as an interdisciplinary research area over the last decades, mostly because of new experimental technologies (ultra-high vacuum, for instance), as well as because of a novel paradigm, the ‘surface science’ approach. The book describes the second transformation which is now taking place pushed by the availability of powerful quantum-mechanical theoretical methods implemented numerically. In the book, experiment and theory progress hand in hand with an unprecedented degree of accuracy and control. The book presents how modern surface science targets the atomic-level u...

Evaluation of abrasive waterjet produced titan surfaces topography by spectral analysis techniques

Directory of Open Access Journals (Sweden)

D. Kozak

2012-01-01

Full Text Available Experimental study of a titan grade 2 surface topography prepared by abrasive waterjet cutting is performed using methods of the spectral analysis. Topographic data are acquired by means of the optical profilometr MicroProf®FRT. Estimation of the areal power spectral density of the studied surface is carried out using the periodogram method combined with the Welch´s method. Attention is paid to a structure of the areal power spectral density, which is characterized by means of the angular power spectral density. This structure of the areal spectral density is linked to the fine texture of the surface studied.

Estimation of the Maximum Output Power of Double-Clad Photonic Crystal Fiber Laser

International Nuclear Information System (INIS)

Chen Yue-E; Wang Yong; Qu Xi-Long

2012-01-01

Compared with traditional optical fiber lasers, double-clad photonic crystal fiber (PCF) lasers have larger surface-area-to-volume ratios. With an increase of output power, thermal effects may severely restrict output power and deteriorate beam quality of fiber lasers. We utilize the heat-conduction equations to estimate the maximum output power of a double-clad PCF laser under natural-convection, air-cooling, and water-cooling conditions in terms of a certain surface-volume heat ratio of the PCF. The thermal effects hence define an upper power limit of double-clad PCF lasers when scaling output power. (fundamental areas of phenomenology(including applications))

Deposition Assessment Of Anthropogenic Airborne 210Po And 210Pb In The Mosses And Surface Soil At The Vicinity Of A Coal-Fired Power Plant

International Nuclear Information System (INIS)

Zal U'yun Wan Mahmood; Nita Salina Abu Bakar; Abdul Kadir Ishak

2014-01-01

Anthropogenic airborne depositions of 210 Po and 210 Pb in the mosses and surface soil collected at the vicinity of a coal-fired power plant were assessed. The purpose of the study was to determine activity concentrations of 210 Po, 210 Pb and its activity ratio ( 210 Po/ 210 Pb). Other purposes were to determine their concentration factor (CF) in relation to track the potential source of those radionuclides and to identify most suitable moss species as a biological indicator for atmospheric deposition contaminants. In this study, different species of mosses Leucobryum aduncum, Campylopus serratus, Syrrhopodon ciliates and Vesicularia montagnei were collected in May 2011 at the area around 30 km radius from Tanjung Bin coal-fired power plant located in Pontian, Johor. The activity concentrations of 210 Po 210 Pb and 210 Po/ 210 Pb in mosses were in the range of 76.81 ± 4.94 - 251.33 ± 16.33 Bqkg -1 dry wt., 54.37 ± 3.38 - 164.63 ± 11.64 Bqkg -1 dry wt. and 1.10 - 2.00, respectively. Meanwhile the ranges for those radionuclides in the surface soil were 33.53 ± 2.10 - 183.93 ± 12.01 Bqkg -1 dry wt., 17.92 ± 1.18 - 298.60 ± 23.70 Bqkg -1 dry wt. and 1.57 - 2.44, respectively. Corresponding high ability of Leucobryum aduncum to accumulate more 210 Po and 210 Pb, wide geographical distribution, most abundant and high CF, therefore, the findings can be concluded this species was the most suitable as a biological indicator for atmospheric deposition contaminants such as 210 Po and 210 Pb. Furthermore, it is clear the accumulation of 210 Po and 210 Pb in mosses might be supplied from various sources of atmospheric deposition such as coal-fired power plant operation, industrial, agriculture and fertilizer activities, burned fuel fossil and forest; and other potential sources. Meanwhile, the main source of 210 Po and 210 Pb in surface soil is supplied from the in situ decay of radon and radium. (author)

High Power Picosecond Laser Surface Micro-texturing of H13 Tool Steel and Pattern Replication onto ABS Plastics via Injection Moulding

Science.gov (United States)

Otanocha, Omonigho B.; Li, Lin; Zhong, Shan; Liu, Zhu

2016-03-01

H13 tool steels are often used as dies and moulds for injection moulding of plastic components. Certain injection moulded components require micro-patterns on their surfaces in order to modify the physical properties of the components or for better mould release to reduce mould contamination. With these applications it is necessary to study micro-patterning to moulds and to ensure effective pattern transfer and replication onto the plastic component during moulding. In this paper, we report an investigation into high average powered (100 W) picosecond laser interactions with H13 tool steel during surface micro-patterning (texturing) and the subsequent pattern replication on ABS plastic material through injection moulding. Design of experiments and statistical modelling were used to understand the influences of laser pulse repetition rate, laser fluence, scanning velocity, and number of scans on the depth of cut, kerf width and heat affected zones (HAZ) size. The characteristics of the surface patterns are analysed. The process parameter interactions and significance of process parameters on the processing quality and efficiency are characterised. An optimum operating window is recommended. The transferred geometry is compared with the patterns generated on the dies. A discussion is made to explain the characteristics of laser texturing and pattern replication on plastics.

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.

Quantitative photography of intermittency in surface wave turbulence

International Nuclear Information System (INIS)

Wright, W.; Budakian, R.; Putterman, S.J.

1997-01-01

At high amplitudes of excitation surface waves on water distribute their energy according to a Kolmogorov type of turbulent power spectrum. We have used diffusing light photography to measure the power spectrum and to quantify the presence of large structures in the turbulent state

Ocean thermal gradient as a generator of electricity. OTEC power plant

Science.gov (United States)

Enrique, Luna-Gomez Victor; Angel, Alatorre-Mendieta Miguel

2016-04-01

The OTEC (Ocean Thermal Energy Conversion) is a power plant that uses the thermal gradient of the sea water between the surface and a depth of about 700 meters. It works by supplying the heat to a steam machine, for evaporation, with sea water from the surface and cold, to condense the steam, with deep sea water. The energy generated by the power plant OTEC can be transferred to the electric power grid, another use is to desalinate seawater. During the twentieth century in some countries experimental power plants to produce electricity or obtaining drinking water they were installed. On the Mexico's coast itself this thermal gradient, as it is located in tropical seas it occurs, so it has possibilities of installing OTEC power plant type. In this paper one type OTEC power plant operation is represented in most of its components.

Boiling and quenching heat transfer advancement by nanoscale surface modification.

Science.gov (United States)

Hu, Hong; Xu, Cheng; Zhao, Yang; Ziegler, Kirk J; Chung, J N

2017-07-21

All power production, refrigeration, and advanced electronic systems depend on efficient heat transfer mechanisms for achieving high power density and best system efficiency. Breakthrough advancement in boiling and quenching phase-change heat transfer processes by nanoscale surface texturing can lead to higher energy transfer efficiencies, substantial energy savings, and global reduction in greenhouse gas emissions. This paper reports breakthrough advancements on both fronts of boiling and quenching. The critical heat flux (CHF) in boiling and the Leidenfrost point temperature (LPT) in quenching are the bottlenecks to the heat transfer advancements. As compared to a conventional aluminum surface, the current research reports a substantial enhancement of the CHF by 112% and an increase of the LPT by 40 K using an aluminum surface with anodized aluminum oxide (AAO) nanoporous texture finish. These heat transfer enhancements imply that the power density would increase by more than 100% and the quenching efficiency would be raised by 33%. A theory that links the nucleation potential of the surface to heat transfer rates has been developed and it successfully explains the current finding by revealing that the heat transfer modification and enhancement are mainly attributed to the superhydrophilic surface property and excessive nanoscale nucleation sites created by the nanoporous surface.

Low Cost Radiator for Fission Power Thermal Control, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — NASA GRC is developing fission power system technology for future space transportation and surface power applications. The early systems are envisioned in the 10 to...

Rare-Earth Surface Alloying: A New Phase for GdAu2

International Nuclear Information System (INIS)

Corso, M.; Schiller, F.; Fernandez, L.; Verstraete, M. J.; Ormaza, M.; Greber, T.; Torrent, M.; Rubio, A.; Ortega, J. E.

2010-01-01

Surface alloying is a powerful way of varying physical and chemical properties of metals, for a number of applications from catalysis to nuclear and green technologies. Surfaces offer many degrees of freedom, giving rise to new phases that do not have a bulk counterpart. However, the atomic characterization of distinct surface compounds is a major task, which demands powerful experimental and theoretical tools. Here we illustrate the process for the case of a GdAu 2 surface phase of extraordinary crystallinity. The combined use of surface-sensitive techniques and state-of-the-art ab initio calculations disentangles its atomic and electronic properties. In particular, the stacking of the surface layers allows for gadolinium's natural ferromagnetic state, at variance with the bulk phase, where frustration leads to antiferromagnetic interlayer coupling.

Local wall power loading variations in thermonuclear fusion devices

International Nuclear Information System (INIS)

Carroll, M.C.; Miley, G.H.

1989-01-01

A 2 1/2-dimensional geometric model is presented that allows calculation of power loadings at various points on the first wall of a thermonuclear fusion device. Given average wall power loadings for brems-strahlung, cyclotron radiation charged particles, and neutrons, which are determined from various plasma-physics computation models, local wall heat loads are calculated by partitioning the plasma volume and surface into cells and superimposing the heating effects of the individual cells on selected first-wall differential areas. Heat loads from the entire plasma are thus determined as a function of position on the first-wall surface. Significant differences in local power loadings were found for most fusion designs, and it was therefore concluded that the effect of local power loading variations must be taken into account when calculating temperatures and heat transfer rates in fusion device first walls

Improvement of silicon direct bonding using surfaces activated by hydrogen plasma treatment

CERN Document Server

Choi, W B; Lee Jae Sik; Sung, M Y

2000-01-01

The plasma surface treatment, using hydrogen gas, of silicon wafers was studied as a pretreatment for silicon direct bonding. Chemical reactions of the hydrogen plasma with the surfaces were used for both surface activation and removal of surface contaminants. Exposure of the silicon wafers to the plasma formed an active oxide layer on the surface. This layer was hydrophilic. The surface roughness and morphology were examined as functions of the plasma exposure time and power. The surface became smoother with shorter plasma exposure time and lower power. In addition, the plasma surface treatment was very efficient in removing the carbon contaminants on the silicon surface. The value of the initial surface energy, as estimated by using the crack propagation method, was 506 mJ/M sup 2 , which was up to about three times higher than the value for the conventional direct bonding method using wet chemical treatments.

High-Power Laser Cutting of Steel Plates: Heat Affected Zone Analysis

Directory of Open Access Journals (Sweden)

Imed Miraoui

2016-01-01

Full Text Available The thermal effect of CO2 high-power laser cutting on cut surface of steel plates is investigated. The effect of the input laser cutting parameters on the melted zone depth (MZ, the heat affected zone depth (HAZ, and the microhardness beneath the cut surface is analyzed. A mathematical model is developed to relate the output process parameters to the input laser cutting parameters. Three input process parameters such as laser beam diameter, cutting speed, and laser power are investigated. Mathematical models for the melted zone and the heat affected zone depth are developed by using design of experiment approach (DOE. The results indicate that the input laser cutting parameters have major effect on melted zone, heat affected zone, and microhardness beneath cut surface. The MZ depth, the HAZ depth, and the microhardness beneath cut surface increase as laser power increases, but they decrease with increasing cutting speed. Laser beam diameter has a negligible effect on HAZ depth but it has a remarkable effect on MZ depth and HAZ microhardness. The melted zone depth and the heat affected zone depth can be reduced by increasing laser cutting speed and decreasing laser power and laser beam diameter.

Nuclear Power in Space.

Science.gov (United States)

Department of Energy, Washington, DC. Nuclear Energy Office.

Research has shown that nuclear radioisotope power generators can supply compact, reliable, and efficient sources of energy for a broad range of space missions. These missions range from televising views of planetary surfaces to communicating scientific data to Earth. This publication presents many applications of the advancing technology and…

Design aspects of the alpha repository. II. Conceptual layouts of underground storage facilities

International Nuclear Information System (INIS)

Grams, W.H.

1975-01-01

Five conceptual repository layouts are presented: linear repository, 1 panel; bow tie repository, 2 panels; maltese cross repository, 4 panels; snowflake repository; 5 panels, and sash window repository, 8 panels. The layouts are compared with respect to excavation requirements, haulage distances, ventilation flow path designs, and safety features

Underground coal equipment

Energy Technology Data Exchange (ETDEWEB)

Chadwick, J.

2002-12-01

This paper reports on increasing automation and enhanced productivity on longwalls, new development cutting and bolting technologies and haulage systems. Amongst equipment discussed is DBT's Electra series EL3000 shearer, the Dosco LH1400 roadheader with onboard bolters, and Joy 12 CM30 continuous miners. 4 photos.

Nuclear power technology requirements for NASA exploration missions

International Nuclear Information System (INIS)

Bloomfield, H.S.

1990-01-01

This paper discusses how future exploration of the Moon and Mars will mandate developments in many areas of technology. In particular, major advances will be required in planet surface power systems and space transportation systems. Critical nuclear technology challenges that can enable strategic self-sufficiency, acceptable operational costs and cost-effective space transportation goals for NASA exploration missions have been identified. Critical technologies for surface power systems include stationary and mobile nuclear reactor and radio-isotope heat sources coupled to static and dynamic power conversion devices. These technologies can provide dramatic reductions in mass leading to operational and transportation cost savings. Critical technologies for space transportation systems include nuclear thermal rocket and nuclear electric propulsion options which present compelling concepts for significantly reducing mass, cost or travel time required for Earth-Mars transport

Ion beam surface treatment: A new capability for rapid melt and resolidification of surfaces

International Nuclear Information System (INIS)

Stinnett, R.W.; McIntyre, D.C.; Buchheit, R.G.; Greenly, J.B.; Thompson, M.O.

1994-01-01

The emerging capability to produce high average power (5--250 kW) pulsed ion beams at 0.2--2 MeV energies is enabling us to develop a new, commercial-scale thermal surface treatment technology called Ion Beam Surface Treatment (IBEST). This technique uses high energy, pulsed (≤100 ns) ion beams to directly deposit energy in the top 2--20 micrometers of the surface of any material. Depth of treatment is controllable by varying the ion energy and species. Deposition of the energy with short pulses in a thin surface layer allows melting of the layer with relatively small energies and allows rapid cooling of the melted layer by thermal diffusion into the underlying substrate. Typical cooling rates of this process (10 9 10 10 K/sec) cause rapid resolidification, resulting in production of non-equilibrium microstructures (nano-crystalline and metastable phases) that have significantly improved corrosion, wear, and hardness properties. We have conducted IBEST feasibility experiments with results confirming surface hardening, nanocrystaline grain formation, metal surface polishing, controlled melt of ceramic surfaces, and surface cleaning

Light scattering by sinusoidal surfaces: illumination windows and harmonics in standards.

Science.gov (United States)

Marx, E; Lettieri, T R; Vorburger, T V

1995-03-01

Sinusoidal surfaces can be used as material standards to help calibrate instruments that measure the angular distribution of the intensity of light scattered by arbitrary surfaces, because the power in the diffraction peaks varies over several orders of magnitude. The calculated power in the higher-order diffraction peaks from sinusoidal surfaces expressed in terms of Bessel functions is much smaller than the values determined from angular distributions that are measured or computed from measured profiles, both of which are determined mainly by the harmonic contents of the profile. The finite size of the illuminated area, represented by an illumination window, gives rise to a background that is much larger than the calculated power in the higher-order peaks. For a rectangular window of a size equal to an even number of periods of the sinusoid, a computation of the power distribution produces minima at or near the location of the diffraction angles for higher-order diffraction angles.

Optical fiber cable for transmission of high power laser energy over great distances

Science.gov (United States)

Zediker, Mark S.; Rinzler, Charles C.; Faircloth, Brian O.; Moxley, Joel F.; Koblick, Yeshaya

2016-05-24

There is provided a system and apparatus for the transmission of high power laser energy over great distances without substantial power loss and without the presence of stimulated Raman scattering. There is further provided systems and optical fiber cable configurations and optical fiber structures for the delivering high power laser energy over great distances to a tool or surface to perform an operation or work with the tool or upon the surface.

SEI power source alternatives for rovers and other multi-kWe distributed surface applications

Science.gov (United States)

Bents, David J.; Kohout, L. L.; Mckissock, Barbara I.; Rodriguez, C. D.; Withrow, C. A.; Colozza, A.; Hanlon, James C.; Schmitz, Paul C.

1991-01-01

To support the Space Exploration Initiative (SEI), a study was performed to investigate power system alternatives for the rover vehicles and servicers that were subsequently generated for each of these rovers and servicers, candidate power sources incorporating various power generation and energy storage technologies were identified. The technologies were those believed most appropriate to the SEI missions, and included solar, electrochemical, and isotope systems. The candidates were characterized with respect to system mass, deployed area, and volume. For each of the missions a preliminary selection was made. Results of this study depict the available power sources in light of mission requirements as they are currently defined.

Strong asymmetry for surface modes in nonlinear lattices with long-range coupling

International Nuclear Information System (INIS)

Martinez, Alejandro J.; Vicencio, Rodrigo A.; Molina, Mario I.

2010-01-01

We analyze the formation of localized surface modes on a nonlinear cubic waveguide array in the presence of exponentially decreasing long-range interactions. We find that the long-range coupling induces a strong asymmetry between the focusing and defocusing cases for the topology of the surface modes and also for the minimum power needed to generate them. In particular, for the defocusing case, there is an upper power threshold for exciting staggered modes, which depends strongly on the long-range coupling strength. The power threshold for dynamical excitation of surface modes increases (decreases) with the strength of long-range coupling for the focusing (defocusing) cases. These effects seem to be generic for discrete lattices with long-range interactions.

Power matching for pellet fusion

International Nuclear Information System (INIS)

Martin, R.L.; Arnold, R.C.

1976-01-01

The number of beams required for optimum power transfer from a given power source to the surface of a pellet is derived. The result is valid for linear optical systems, hence, for pellet fusion by laser or high energy ion beams. The optimum number of beams turns out to be inconceivably large for any practical system. Practical pellet fusion by lasers or high energy heavy ion beams must thus compromise physical principles in favor of reduced cost and optical complexity

Analysis of the Hybrid Power System for High-Altitude Unmanned Aircraft

Directory of Open Access Journals (Sweden)

Kangwen Sun

2015-01-01

Full Text Available The application of single solar array on high-altitude unmanned aircraft will waste energy because of its low conversion efficiency. Furthermore, since its energy utilization is limited, the surface temperature of solar array will rise to 70°C due to the waste solar energy, thus reducing the electrical performance of the solar array. In order to reuse the energy converted into heat by solar array, a hybrid power system is presented in this paper. In the hybrid power system, a new electricity-generating method is adopted to spread the photovoltaic cell on the wing surface and arrange photothermal power in the wing box section. Because the temperature on the back of photovoltaic cell is high, it can be used as the high-temperature heat source. The lower wing surface can be a low-temperature cold source. A high-altitude unmanned aircraft was used to analyze the performances of pure solar-powered aircraft and hybrid powered aircraft. The analysis result showed that the hybrid system could reduce the area of wing by 19% and that high-altitude unmanned aircraft with a 35 m or less wingspan could raise the utilization rate of solar energy per unit area after adopting the hybrid power system.

Corrosion-related failures in power plant condensers. Final report

International Nuclear Information System (INIS)

Beavers, J.A.; Agrawal, A.K.; Berry, W.E.

1980-08-01

A survey of the literature has been conducted for the Electric Power Research Institute on corrosion failures in surface condensers. The survey was directed toward condenser failures in pressurized water reactor (PWR) power plants but includes pertinent literature related to fossil and to other nuclear power plants. It includes literature on reported service failures and on experimental studies that impact on these failures

Start-up of belt conveyors used for haulage of large lumps under difficult climatic conditions

Energy Technology Data Exchange (ETDEWEB)

Drobny, J

1979-01-01

Investigations are discussed carried out by the Research and Development Center for Brown Coal in Most, Czechoslovakia into effects of climate, weather and mass of coal lumps on reliability of belt conveyors in surface mines. Dirt buildup on the driving drums reduces friction and increases belt sliding hazards. Belt wear increases. Driving drum diameter, increased by the buildup, negatively influences load distribution among the electric motors of the drive system. In extreme cases belt wear and irregular load distribution cause belt failures. Methods for buildup removal used in Czechoslovakia and methods for protection of the return side of a conveyor are described. Effects of large mass of coal lumps and ice buildup on large lumps on the risk of belt damage (cuts, punctures etc,) are discussed. Recommendations for design of coal transfer points are made. 2 refs.

Modeling, fabrication and high power optical characterization of plasmonic waveguides

DEFF Research Database (Denmark)

Lavrinenko, Andrei; Lysenko, Oleg

2015-01-01

This paper describes modeling, fabrication and high power optical characterization of thin gold films embedded in silicon dioxide. The propagation vector of surface plasmon polaritons has been calculated by the effective index method for the wavelength range of 750-1700 nm and film thickness of 15......, 30 and 45 nm. The fabrication process of such plasmonic waveguides with width in the range of 1-100 μm and their quality inspection are described. The results of optical characterization of plasmonic waveguides using a high power laser with the peak power wavelength 1064 nm show significant deviation...... from the linear propagation regime of surface plasmon polaritons at the average input power of 100 mW and above. Possible reasons for this deviation are heating of the waveguides and subsequent changes in the coupling and propagation losses....

Effects of different lasers and particle abrasion on surface characteristics of zirconia ceramics.

Directory of Open Access Journals (Sweden)

Sakineh Arami

2014-04-01

Full Text Available The aim of this study was to assess the surface of yttrium-stabilized tetragonal zirconia (Y-TZP after surface treatment with lasers and airborne-particle abrasion.First, 77 samples of presintered zirconia blocks measuring 10 × 10 × 2 mm were made, sintered and polished. Then, they were randomly divided into 11 groups (n=7 and received surface treatments namely, Er:YAG laser irradiation with output power of 1.5, 2 and 2.5 W, Nd:YAG laser with output power of 1.5, 2 and 2.5 W, CO2 laser with output power of 3, 4 and 5 W, AL2O3 airborne-particle abrasion (50μ and no treatment (controls. Following treatment, the parameters of surface roughness such as Ra, Rku and Rsk were evaluated using a digital profilometer and surface examination was done by SEM.According to ANOVA and Tukey's test, the mean surface roughness (Ra after Nd:YAG laser irradiation at 2 and 2.5 W was significantly higher than other groups. Roughness increased with increasing output power of Nd:YAG and CO2 lasers. Treated surfaces by Er:YAG laser and air abrasion showed similar surface roughness. SEM micrographs showed small microcracks in specimens irradiated with Nd:YAG and CO2 lasers.Nd:YAG laser created a rough surface on the zirconia ceramic with many microcracks; therefore, its use is not recommended. Air abrasion method can be used with Er:YAG laser irradiation for the treatment of zirconia ceramic.

Thin film surface reconstruction analysis

Energy Technology Data Exchange (ETDEWEB)

Imperatori, P [CNR, Monterotondo Stazione, Rome (Italy). Istituto di Chimica dei materiali

1996-09-01

The study of the atomic structure of surfaces and interfaces is a fundamental step in the knowledge and the development of new materials. Among the several surface-sensitive techniques employed to characterise the atomic arrangements, grazing incidence x-ray diffraction (GIXD) is one of the most powerful. With a simple data treatment, based on the kinematical theory, and using the classical methods of x-ray bulk structure determination, it gives the atomic positions of atoms at a surface or an interface and the atomic displacements of subsurface layers for a complete determination of the structure. In this paper the main features of the technique will be briefly reviewed and selected of application to semiconductor and metal surfaces will be discussed.

Flow Components in a NaK Test Loop Designed to Simulate Conditions in a Nuclear Surface Power Reactor

Science.gov (United States)

Polzin, Kurt A.; Godfroy, Thomas J.

2008-01-01

A test loop using NaK as the working fluid is presently in use to study material compatibility effects on various components that comprise a possible nuclear reactor design for use on the lunar surface. A DC electromagnetic (EM) pump has been designed and implemented as a means of actively controlling the NaK flow rate through the system and an EM flow sensor is employed to monitor the developed flow rate. These components allow for the matching of the flow rate conditions in test loops with those that would be found in a full-scale surface-power reactor. The design and operating characteristics of the EM pump and flow sensor are presented. In the EM pump, current is applied to a set of electrodes to produce a Lorentz body force in the fluid. A measurement of the induced voltage (back-EMF) in the flow sensor provides the means of monitoring flow rate. Both components are compact, employing high magnetic field strength neodymium magnets thermally coupled to a water-cooled housing. A vacuum gap limits the heat transferred from the high temperature NaK tube to the magnets and a magnetically-permeable material completes the magnetic circuit. The pump is designed to produce a pressure rise of 5 psi, and the flow sensor's predicted output is roughly 20 mV at the loop's nominal flow rate of 0.5 GPM.

78 FR 59066 - Petitions for Modification of Application of Existing Mandatory Safety Standards

Science.gov (United States)

2013-09-25

... thirty (30) sprays along each of approximately ten primary belt-conveyor drives and an average of sixty... using the hand-loading method. (8) Belt conveyor haulage is not used in this underground mine for...-loading mining methods. (3) Development above the active gangway is designed to mine into the level above...

30 CFR 77.1602 - Use of aerial tramways to transport persons.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Use of aerial tramways to transport persons. 77.1602 Section 77.1602 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL... UNDERGROUND COAL MINES Loading and Haulage § 77.1602 Use of aerial tramways to transport persons. Persons...

Cost and time models for the evaluation of intermodal chains by using short sea shipping in the North Sea Region: the Rosyth-Zeebrugge route

DEFF Research Database (Denmark)

Lopez, Alba Martínez; Kronbak, Jacob; Jiang, Liping

2015-01-01

This paper is framed in the context of the EU Interreg IVB North Sea Region project Food Port. In line with this project, this paper aims to define mathematically cost and time models able to provide realistic information about the performances of road haulage and of intermodal chains using short...

30 CFR 56.9315 - Dust control.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Dust control. 56.9315 Section 56.9315 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND... control. Dust shall be controlled at muck piles, material transfer points, crushers, and on haulage roads...

Harvesting electrostatic energy using super-hydrophobic surfaces

Science.gov (United States)

Pociecha, Dominik; Zylka, Pawel

2016-11-01

Almost all environments are now being extensively populated by miniaturized, nano-powered electronic sensor devices communicated together through wireless sensor networks building Internet of Things (IoT). Various energy harvesting techniques are being more and more frequently proposed for battery-less powering of such remote, unattended, implantable or wearable sensors or other low-power electronic gadgets. Energy harvesting relays on extracting energy from the ambient sources readily accessible at the sensor location and converting it into electrical power. The paper exploits possibility of generating electric energy safely accessible for nano-power electronics using tribo-electric and electrostatic induction phenomena displayed at super-hydrophobic surfaces impinged by water droplets. Mechanism of such interaction is discussed and illustrated by experimental results.

Tolerance and nature of residual refraction in symmetric power space as principal lens powers and meridians change.

Science.gov (United States)

Abelman, Herven; Abelman, Shirley

2014-01-01

Unacceptable principal powers in well-centred lenses may require a toric over-refraction which differs in nature from the one where correct powers have misplaced meridians. This paper calculates residual (over) refractions and their natures. The magnitude of the power of the over-refraction serves as a general, reliable, real scalar criterion for acceptance or tolerance of lenses whose surface relative curvatures change or whose meridians are rotated and cause powers to differ. Principal powers and meridians of lenses are analogous to eigenvalues and eigenvectors of symmetric matrices, which facilitates the calculation of powers and their residuals. Geometric paths in symmetric power space link intended refractive correction and these carefully chosen, undue refractive corrections. Principal meridians alone vary along an arc of a circle centred at the origin and corresponding powers vary autonomously along select diameters of that circle in symmetric power space. Depending on the path of the power change, residual lenses different from their prescription in principal powers and meridians are pure cross-cylindrical or spherocylindrical in nature. The location of residual power in symmetric dioptric power space and its optical cross-representation characterize the lens that must be added to the compensation to attain the power in the prescription.

Quantitative roughness characterization of geological surfaces and implications for radar signature analysis

DEFF Research Database (Denmark)

Dierking, Wolfgang

1999-01-01

Stochastic surface models are useful for analyzing in situ roughness profiles and synthetic aperture radar (SAR) images of geological terrain. In this paper, two different surface models are discussed: surfaces with a stationary random roughness (conventional model) and surfaces with a power...

Improved algorithm for surface display from volumetric data

International Nuclear Information System (INIS)

Lobregt, S.; Schaars, H.W.G.K.; OpdeBeek, J.C.A.; Zonneveld, F.W.

1988-01-01

A high-resolution surface display is produced from three-dimensional datasets (computed tomography or magnetic resonance imaging). Unlike other voxel-based methods, this algorithm does not show a cuberille surface structure, because the surface orientation is calculated from original gray values. The applied surface shading is a function of local orientation and position of the surface and of a virtual light source, giving a realistic impression of the surface of bone and soft tissue. The projection and shading are table driven, combining variable viewpoint and illumination conditions with speed. Other options are cutplane gray-level display and surface transparency. Combined with volume scanning, this algorithm offers powerful application possibilities

Anomalous pH-Dependent Nanofluidic Salinity Gradient Power.

Science.gov (United States)

Yeh, Li-Hsien; Chen, Fu; Chiou, Yu-Ting; Su, Yen-Shao

2017-12-01

Previous studies on nanofluidic salinity gradient power (NSGP), where energy associated with the salinity gradient can be harvested with ion-selective nanopores, all suggest that nanofluidic devices having higher surface charge density should have higher performance, including osmotic power and conversion efficiency. In this manuscript, this viewpoint is challenged and anomalous counterintuitive pH-dependent NSGP behaviors are reported. For example, with equal pH deviation from its isoelectric point (IEP), the nanopore at pH IEP is shown to have smaller surface charge density but remarkably higher NSGP performance than that at pH > IEP. Moreover, for sufficiently low pH, the NSGP performance decreases with lowering pH (increasing nanopore charge density). As a result, a maximum osmotic power density as high as 5.85 kW m -2 can be generated along with a conversion efficiency of 26.3% achieved for a single alumina nanopore at pH 3.5 under a 1000-fold concentration ratio. Using the rigorous model with considering the surface equilibrium reactions on the pore wall, it is proved that these counterintuitive surface-charge-dependent NSGP behaviors result from the pH-dependent ion concentration polarization effect, which yields the degradation in effective concentration ratio across the nanopore. These findings provide significant insight for the design of next-generation, high-performance NSGP devices. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Low reflectance high power RF load

Science.gov (United States)

Ives, R. Lawrence; Mizuhara, Yosuke M.

2016-02-02

A load for traveling microwave energy has an absorptive volume defined by cylindrical body enclosed by a first end cap and a second end cap. The first end cap has an aperture for the passage of an input waveguide with a rotating part that is coupled to a reflective mirror. The inner surfaces of the absorptive volume consist of a resistive material or are coated with a coating which absorbs a fraction of incident RF energy, and the remainder of the RF energy reflects. The angle of the reflector and end caps is selected such that reflected RF energy dissipates an increasing percentage of the remaining RF energy at each reflection, and the reflected RF energy which returns to the rotating mirror is directed to the back surface of the rotating reflector, and is not coupled to the input waveguide. Additionally, the reflector may have a surface which generates a more uniform power distribution function axially and laterally, to increase the power handling capability of the RF load. The input waveguide may be corrugated for HE11 mode input energy.

Vehicle for surface decontamination by electropolishing

International Nuclear Information System (INIS)

Maury, A.

1984-01-01

The invention concerns a remote controlled, electric powered vehicle for continuous decontamination of several supports forming an angle for instance the bottom and the walls of nuclear swimming pools. The vehicle is provided with all the means required for electropolishing (electrolyte, pumps, effluent recovery etc...) and two electropolishing units, one under the vehicle for horizontal surface treatment the other adjustable in height on a bracket for vertical surface treatment [fr

2D Spatial Frequency Considerations in Comparing 1D Power Spectral Density Measurements

International Nuclear Information System (INIS)

Takacs, P.Z.; Barber, S.; Church, E.L.; Kaznatcheev, K.; McKinney, W.R.; Yashchuk, V.Y.

2010-01-01

The frequency footprint of ID and 2D profiling instruments needs to be carefully considered in comparing ID surface roughness spectrum measurements made by different instruments. Contributions from orthogonal direction frequency components can not be neglected. The use of optical profiling instruments is ubiquitous in the measurement of the roughness of optical surfaces. Their ease-of-use and non-contact measurement method found widespread use in the optics industry for measuring the quality of delicate optical surfaces. Computerized digital data acquisition with these instruments allowed for quick and easy calculation of surface roughness statistics, such as root-mean-square (RMS) roughness. The computing power of the desktop computer allowed for the rapid conversion of spatial domain data into the frequency domain, enabling the application of sophisticated signal processing techniques to be applied to the analysis of surface roughness, the most powerful of which is the power spectral density (PSP) function. Application of the PSD function to surface statistics introduced the concept of 'bandwidth-limited' roughness, where the value of the RMS roughness depends critically upon the spatial frequency response of the instrument. Different instruments with different spatial frequency response characteristics give different answers when measuring the same surface.

Mid-infrared PbTe vertical external cavity surface emitting laser on Si-substrate with above 1 W output power

Science.gov (United States)

Rahim, M.; Fill, M.; Felder, F.; Chappuis, D.; Corda, M.; Zogg, H.

2009-12-01

Mid-infrared vertical external cavity surface emitting lasers (VECSELs) emitting above 1 W output power in pulsed mode and up to 17 mW in continuous mode at -172 °C were realized. Emission wavelength changes from 5 μm at -172 °C to 3.6 μm at 20 °C heat sink temperature. The active medium is a one wavelength thick PbTe layer grown by molecular beam epitaxy on a Si-substrate. It is followed by a 2.5 pair Pb1-yEuyTe/EuTe epitaxial Bragg mirror. The cavity is completed with an external curved Pb1-yEuyTe/BaF2 mirror. The VECSEL is optically pumped with 1.55 μm wavelength laser and In-soldered to Cu heat sink. No microstructural processing is needed.

What is happening under the surface? Power, conflict and the performance of medical teams.

Science.gov (United States)

Janss, Rozemarijn; Rispens, Sonja; Segers, Mien; Jehn, Karen A

2012-09-01

The effect of teamwork on team performance is broadly recognised in the medical field. This recognition is manifested in educational programmes in which attention to interpersonal behaviours during teamwork is growing. Conflict and power differences influence interpersonal behaviours and are marked topics in studies of group functioning in the social and organisational psychology literature. Insights from the domain of social sciences put the ongoing improvement of teamwork into broader perspective. This paper shows how knowledge from the domain of social and organisational psychology contributes to the understanding of teamwork in the medical environment. More specifically, this paper suggests that unfolding the underlying issues of power and conflict within medical teams can be of extra help in the development of educational interventions aimed at improving team performance. We review the key social psychology and organisational behaviour literature concerning power and conflict, and relate the insights derived from this to the team process of ad hoc medical action teams. We present a theoretical framework in which insights into power and conflict are used to explain and predict team dynamics in ad hoc medical action teams. Power and conflict strongly influence interpersonal behaviour. Characteristics of medical action teams give rise to all kinds of issues of disagreement and are accompanied by complex issues of intra-team power distribution. We argue that how team members coordinate, cooperate and communicate is steered by members' personal motivations, which, in turn, strongly depend on their perceptions of power and conflict. Given the importance of the performance of these teams, we suggest future directions for the development of training interventions building on knowledge and theories derived from social and organisational psychology. © Blackwell Publishing Ltd 2012.

Towards Enhanced Performance Thin-film Composite Membranes via Surface Plasma Modification

Science.gov (United States)

Reis, Rackel; Dumée, Ludovic F.; Tardy, Blaise L.; Dagastine, Raymond; Orbell, John D.; Schutz, Jürg A.; Duke, Mikel C.

2016-01-01

Advancing the design of thin-film composite membrane surfaces is one of the most promising pathways to deal with treating varying water qualities and increase their long-term stability and permeability. Although plasma technologies have been explored for surface modification of bulk micro and ultrafiltration membrane materials, the modification of thin film composite membranes is yet to be systematically investigated. Here, the performance of commercial thin-film composite desalination membranes has been significantly enhanced by rapid and facile, low pressure, argon plasma activation. Pressure driven water desalination tests showed that at low power density, flux was improved by 22% without compromising salt rejection. Various plasma durations and excitation powers have been systematically evaluated to assess the impact of plasma glow reactions on the physico-chemical properties of these materials associated with permeability. With increasing power density, plasma treatment enhanced the hydrophilicity of the surfaces, where water contact angles decreasing by 70% were strongly correlated with increased negative charge and smooth uniform surface morphology. These results highlight a versatile chemical modification technique for post-treatment of commercial membrane products that provides uniform morphology and chemically altered surface properties. PMID:27363670

Surface charge method for molecular surfaces with curved areal elements I. Spherical triangles

Science.gov (United States)

Yu, Yi-Kuo

2018-03-01

Parametrizing a curved surface with flat triangles in electrostatics problems creates a diverging electric field. One way to avoid this is to have curved areal elements. However, charge density integration over curved patches appears difficult. This paper, dealing with spherical triangles, is the first in a series aiming to solve this problem. Here, we lay the ground work for employing curved patches for applying the surface charge method to electrostatics. We show analytically how one may control the accuracy by expanding in powers of the the arc length (multiplied by the curvature). To accommodate not extremely small curved areal elements, we have provided enough details to include higher order corrections that are needed for better accuracy when slightly larger surface elements are used.

Construction of Power Receiving Rectenna Using Mars- In-Situ Materials; A Low Energy Materials Processing Approach

Science.gov (United States)

Curreri, Peter A.; Rose, M. Franklin (Technical Monitor)

2001-01-01

It is highly desirable to have a non-nuclear power rich option for the human exploration of Mars. Utilizing a Solar Electric Propulsion, SEP, / Power Beaming architecture for a non-nuclear power option for a human Mars base potentially avoids the weather and dust sensitivities of the surface photovoltaic option. Further from Mars areosynchronous orbit near year round power can be provided. Mission analysis, however, concludes that ultra high (245 GHz) frequencies or laser transmission technologies are required for Mars landed mass competitiveness with the surface photovoltaic option if the receiving rectifying antenna "rectenna" is transported from Earth. It is suggested in this paper that producing rectenna in situ on Mars surface might make a more conventional 5.8 GHz system competitive with surface PV. The premium of a competitive, robust, continuous base power might make the development of a 10 plus MWe class SEP for human Mars mission a more attractive non-nuclear option.

Fuel-Cell-Powered Vehicle with Hybrid Power Management

Science.gov (United States)

Eichenberg, Dennis J.

2010-01-01

Figure 1 depicts a hybrid electric utility vehicle that is powered by hydrogenburning proton-exchange-membrane (PEM) fuel cells operating in conjunction with a metal hydride hydrogen-storage unit. Unlike conventional hybrid electric vehicles, this vehicle utilizes ultracapacitors, rather than batteries, for storing electric energy. This vehicle is a product of continuing efforts to develop the technological discipline known as hybrid power management (HPM), which is oriented toward integration of diverse electric energy-generating, energy-storing, and energy- consuming devices in optimal configurations. Instances of HPM were reported in five prior NASA Tech Briefs articles, though not explicitly labeled as HPM in the first three articles: "Ultracapacitors Store Energy in a Hybrid Electric Vehicle" (LEW-16876), Vol. 24, No. 4 (April 2000), page 63; "Photovoltaic Power Station With Ultracapacitors for Storage" (LEW- 17177), Vol. 27, No. 8 (August 2003), page 38; "Flasher Powered by Photovoltaic Cells and Ultracapacitors" (LEW-17246), Vol. 27, No. 10 (October 2003), page 37; "Hybrid Power Management" (LEW-17520), Vol. 29, No. 12 (December 2005), page 35; and "Ultracapacitor-Powered Cordless Drill" (LEW-18116-1), Vol. 31, No. 8 (August 2007), page 34. To recapitulate from the cited prior articles: The use of ultracapacitors as energy- storage devices lies at the heart of HPM. An ultracapacitor is an electrochemical energy-storage device, but unlike in a conventional rechargeable electrochemical cell or battery, chemical reactions do not take place during operation. Instead, energy is stored electrostatically at an electrode/electrolyte interface. The capacitance per unit volume of an ultracapacitor is much greater than that of a conventional capacitor because its electrodes have much greater surface area per unit volume and the separation between the electrodes is much smaller.

Solids-based concentrated solar power receiver

Science.gov (United States)

None

2018-04-10

A concentrated solar power (CSP) system includes channels arranged to convey a flowing solids medium descending under gravity. The channels form a light-absorbing surface configured to absorb solar flux from a heliostat field. The channels may be independently supported, for example by suspension, and gaps between the channels are sized to accommodate thermal expansion. The light absorbing surface may be sloped so that the inside surfaces of the channels proximate to the light absorbing surface define downward-slanting channel floors, and the flowing solids medium flows along these floors. Baffles may be disposed inside the channels and oriented across the direction of descent of the flowing solids medium. The channels may include wedge-shaped walls forming the light-absorbing surface and defining multiple-reflection light paths for solar flux from the heliostat field incident on the light-absorbing surface.

Wireless Metal Detection and Surface Coverage Sensing for All-Surface Induction Heating

Directory of Open Access Journals (Sweden)

Veli Tayfun Kilic

2016-03-01

Full Text Available All-surface induction heating systems, typically comprising small-area coils, face a major challenge in detecting the presence of a metallic vessel and identifying its partial surface coverage over the coils to determine which of the coils to power up. The difficulty arises due to the fact that the user can heat vessels made of a wide variety of metals (and their alloys. To address this problem, we propose and demonstrate a new wireless detection methodology that allows for detecting the presence of metallic vessels together with uniquely sensing their surface coverages while also identifying their effective material type in all-surface induction heating systems. The proposed method is based on telemetrically measuring simultaneously inductance and resistance of the induction coil coupled with the vessel in the heating system. Here, variations in the inductance and resistance values for an all-surface heating coil loaded by vessels (made of stainless steel and aluminum at different positions were systematically investigated at different frequencies. Results show that, independent of the metal material type, unique identification of the surface coverage is possible at all freqeuncies. Additionally, using the magnitude and phase information extracted from the coupled coil impedance, unique identification of the vessel effective material is also achievable, this time independent of its surface coverage.

Surface Water in Hawaii

Science.gov (United States)

Oki, Delwyn S.

2003-01-01

Surface water in Hawaii is a valued resource as well as a potential threat to human lives and property. The surface-water resources of Hawaii are of significant economic, ecologic, cultural, and aesthetic importance. Streams supply more than 50 percent of the irrigation water in Hawaii, and although streams supply only a few percent of the drinking water statewide, surface water is the main source of drinking water in some places. Streams also are a source of hydroelectric power, provide important riparian and instream habitats for many unique native species, support traditional and customary Hawaiian gathering rights and the practice of taro cultivation, and possess valued aesthetic qualities. Streams affect the physical, chemical, and aesthetic quality of receiving waters, such as estuaries, bays, and nearshore waters, which are critical to the tourism-based economy of the islands. Streams in Hawaii pose a danger because of their flashy nature; a stream's stage, or water level, can rise several feet in less than an hour during periods of intense rainfall. Streams in Hawaii are flashy because rainfall is intense, drainage basins are small, basins and streams are steep, and channel storage is limited. Streamflow generated during periods of heavy rainfall has led to loss of property and human lives in Hawaii. Most Hawaiian streams originate in the mountainous interiors of the islands and terminate at the coast. Streams are significant sculptors of the Hawaiian landscape because of the erosive power of the water they convey. In geologically young areas, such as much of the southern part of the island of Hawaii, well-defined stream channels have not developed because the permeability of the surface rocks generally is so high that rainfall infiltrates before flowing for significant distances on the surface. In geologically older areas that have received significant rainfall, streams and mass wasting have carved out large valleys.

Tritium-surface interactions

International Nuclear Information System (INIS)

Kirkaldy, J.S.

1983-06-01

The report deals broadly with tritium-surface interactions as they relate to a fusion power reactor enterprise, viz., the vacuum chamber, first wall, peripherals, pumping, fuel recycling, isotope separation, repair and maintenance, decontamination and safety. The main emphasis is on plasma-surface interactions and the selection of materials for fusion chamber duty. A comprehensive review of the international (particularly U.S.) research and development is presented based upon a literature review (about 1 000 reports and papers) and upon visits to key laboratories, Sandia, Albuquerque, Sandia, Livermore and EGβG Idaho. An inventory of Canadian expertise and facilities for RβD on tritium-surface interactions is also presented. A number of proposals are made for the direction of an optimal Canadian RβD program, emphasizing the importance of building on strength in both the technological and fundamental areas. A compendium of specific projects and project areas is presented dealing primarily with plasma-wall interactions and permeation, anti-permeation materials and surfaces and health, safety and environmental considerations. Potential areas of industrial spinoff are identified

Microwave and pulsed power engineering

International Nuclear Information System (INIS)

Hofer, W.W.

1984-01-01

The Microwave and Pulsed Power Engineering Thrust Area is responsible for developing the short-term and long-term engineering resources required to support the growing microwave and pulsed power engineering requirements of several LLNL Programs. The responsibility of this Thrust Area is to initiate applicable research and development projects and to provide capabilities and facilities to permit engineers involved in these and other programs to make significant contributions. In this section, the principal projects are described: dielectric failure prediction using partial discharge analysis, coating dielectrics to increase surface flashover potential, and the microwave generator experiment

Measuring the surface-heating of medical ultrasonic probes

International Nuclear Information System (INIS)

Kollmann, Chr; Vacariu, G; Fialka-Moser, V; Bergmann, H

2004-01-01

Due to converting losses the probe's surface itself is heated up, especially when emitting into air. Possible temperature increases in an ensemble of 15 different diagnostic and therapeutic ultrasound probes from 7 manufacturers in the frequency range between 0.05-7.5 MHz have been examined. Surface temperatures were detected by means of a calibrated IR-thermographic camera using a scheme of various power and pulse settings, as well as different imaging modalitites as used in clinical routine. Depending on the setup and the output power, the absolute surface temperatures of some of the probes emitting in air can be beyond 43 deg. C within 5-7 min.; a maximum surface temperature of 84 deg. C has been detected. Continuous mode or high pulse repetition frequencies on the therapeutic system side, small focused Doppler modes on the diagnostic system side combined with increased emitted acoustic intensities result in high surface temperatures. Within a worst case scenario a potential risk of negative skin changes (heat damage) or non-optimal therapeutic effects seems to be possible if a therapeutic system is used very often and if its emission continues unintentionally. In general the user should be aware that low emission intensities of e.g. 50 mW cm -2 could already produce hot surfaces

Transverse-mode-selectable microlens vertical-cavity surface-emitting laser

DEFF Research Database (Denmark)

Chung, Il-Sug; Debernardi, Pierluigi; Lee, Yong Tak

2010-01-01

A new vertical-cavity surface-emitting laser structure employing a thin microlens is suggested and numerically investigated. The laser can be made to emit in either a high-power Gaussian-shaped single-fundamental mode or a high-power doughnut-shaped higher-order mode. The physical origin...

A simple approach to measure the surface resistivity of insulating materials

DEFF Research Database (Denmark)

Yang, Zhenyu; Wang, Qian

2011-01-01

A simple approach for measuring high surface resistivity of insulating materials using standard laboratory equipments is proposed. The developed system consists of a DC power transformer, a concentric ring probe assembly and a digital multi-meter. The DC power transformer can provide either 500V ...... for different materials, source voltages, and serially connected resistors. The testing results showed that the developed system and methods can provide a reasonably accurate measurement of surface resistivity of insulating materials in a robust and economic manner.......A simple approach for measuring high surface resistivity of insulating materials using standard laboratory equipments is proposed. The developed system consists of a DC power transformer, a concentric ring probe assembly and a digital multi-meter. The DC power transformer can provide either 500V...... or 250V DC signal. The probe assembly is constructed according to Danish Standard (DS/EN 1149-1:2006). The multi-meter (Agilent 3440 1A 6½) is used to measure the micro voltage over a known resistor which is serially connected with electrodes in the probe assembly. In order to obtain reliable...

Direct observation of atoms on surfaces by scanning tunnelling microscopy

International Nuclear Information System (INIS)

Baldeschwieler, J.D.

1989-01-01

The scanning tunnelling microscope is a non-destructive means of achieving atomic level resolution of crystal surfaces in real space to elucidate surface structures, electronic properties and chemical composition. Scanning tunnelling microscope is a powerful, real space surface structure probe complementary to other techniques such as x-ray diffraction. 21 refs., 8 figs

Nanotechnology based surface treatments for corrosion protection and deposit control of power plant equipment. Phase 1

Energy Technology Data Exchange (ETDEWEB)

NONE

2009-05-15

Nanotechnology can provide possibilities for obtaining new valuable information regarding performance and corrosion protection in power plants. In general the desired performance of the contact surfaces is an easy-to-release effect. This is in order to prolong the time interval between cleaning periods or make the cleaning procedures easier and less expensive. Corrosion protection is also desired in order to extend the life time of various parts in the power plants and thus optimize the energy output and overall efficiency of the plant. Functional sol-gel coating based on nanotechnology is tested in a variety of conditions. Applications of functional sol-gel coatings were performed in the condenser and on seven air preheaters at Fynsvaerket, Odense, with corrosion protection as the main issue. Coatings with easy-to-clean effects were tested in the Flue Gas Desulphurization plant at Nordjyllandsvaerket, Aalborg, with the aim of reducing gipsum deposit. Thermo stabilized coatings were tested on tube bundles between in the passage from the 1st to 2end pass and on the wall between 1st and 2end pass at Amagervaerket, Copenhagen, and in the boiler at Haderslev CHP plant. The objective of this test were reducing deposits and increasing corrosion protection. The tested coatings were commercial available coatings and coatings developed in this project. Visual inspections have been performed of all applications except at Nordjyllandsvaerket. Corrosion assessment has been done at DTU - Mechanical Engineering. The results range from no difference between coated and uncoated areas to some improvements. At Amagervaerket the visual assessment showed in general a positive effect with a sol-gel hybrid system and a commercial system regarding removal of deposits. The visual assessment of the air preheaters at Fynsvaerket indicates reduced deposits on a sol-gel nanocomposite coated air preheater compared to an uncoated air preheater. (Author)

Optical surfacing via linear ion source

International Nuclear Information System (INIS)

Wu, Lixiang; Wei, Chaoyang; Shao, Jianda

2017-01-01

We present a concept of surface decomposition extended from double Fourier series to nonnegative sinusoidal wave surfaces, on the basis of which linear ion sources apply to the ultra-precision fabrication of complex surfaces and diffractive optics. The modified Fourier series, or sinusoidal wave surfaces, build a relationship between the fabrication process of optical surfaces and the surface characterization based on power spectral density (PSD) analysis. Also, we demonstrate that the one-dimensional scanning of linear ion source is applicable to the removal of mid-spatial frequency (MSF) errors caused by small-tool polishing in raster scan mode as well as the fabrication of beam sampling grating of high diffractive uniformity without a post-processing procedure. The simulation results show that optical fabrication with linear ion source is feasible and even of higher output efficiency compared with the conventional approach.

Optical surfacing via linear ion source

Energy Technology Data Exchange (ETDEWEB)

Wu, Lixiang, E-mail: wulx@hdu.edu.cn [Key Lab of RF Circuits and Systems of Ministry of Education, Zhejiang Provincial Key Lab of LSI Design, Microelectronics CAD Center, College of Electronics and Information, Hangzhou Dianzi University, Hangzhou (China); Wei, Chaoyang, E-mail: siomwei@siom.ac.cn [Key Laboratory of Materials for High Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); Shao, Jianda, E-mail: jdshao@siom.ac.cn [Key Laboratory of Materials for High Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China)

2017-04-15

We present a concept of surface decomposition extended from double Fourier series to nonnegative sinusoidal wave surfaces, on the basis of which linear ion sources apply to the ultra-precision fabrication of complex surfaces and diffractive optics. The modified Fourier series, or sinusoidal wave surfaces, build a relationship between the fabrication process of optical surfaces and the surface characterization based on power spectral density (PSD) analysis. Also, we demonstrate that the one-dimensional scanning of linear ion source is applicable to the removal of mid-spatial frequency (MSF) errors caused by small-tool polishing in raster scan mode as well as the fabrication of beam sampling grating of high diffractive uniformity without a post-processing procedure. The simulation results show that optical fabrication with linear ion source is feasible and even of higher output efficiency compared with the conventional approach.

Improving the engine power of a catalytic Janus-sphere micromotor by roughening its surface.

Science.gov (United States)

Longbottom, Brooke W; Bon, Stefan A F

2018-03-15

Microspheres with catalytic caps have become a popular model system for studying self-propelled colloids. Existing experimental studies involve predominantly "smooth" particle surfaces. In this study we determine the effect of irregular surface deformations on the propulsive mechanism with a particular focus on speed. The particle surfaces of polymer microspheres were deformed prior to depositing a layer of platinum which resulted in the formation of nanoscopic pillars of catalyst. Self-propulsion was induced upon exposure of the micromotors to hydrogen peroxide, whilst they were dispersed in water. The topological surface features were shown to boost speed (~2×) when the underlying deformations are small (nanoscale), whilst large deformations afforded little difference despite a substantial apparent catalytic surface area. Colloids with deformed surfaces were more likely to display a mixture of rotational and translational propulsion than their "smooth" counterparts.

Thermal Analysis of a Power Conditioning Unit for a Howitzer

Science.gov (United States)

2009-08-01

contact resistance Interface ( mA2 -K / W) AL-PCB 0.000389 AL-AL (thermal grease) 0.000083 AL-power chips 0.003891 AL-power chips (thermal grease...1120 W/ mA2 . Figure 3 shows the view of the box that the source of the solar radiation sees. The inside of the box is cluttered with cables, wiring, and...temperature (130°F) and a conservative convective heat transfer coefficient (5 W/ mA2 ) to all of the outer surfaces. These outer surfaces would

Light transmittance and surface roughness of a feldspathic ceramic CAD-CAM material as a function of different surface treatments.

Science.gov (United States)

Ural, Çağrı; Duran, İbrahim; Evmek, Betül; Kavut, İdris; Cengiz, Seda; Yuzbasioglu, Emir

2016-07-15

The aim of the present study was to determine the effect of different surface treatments on light transmission of aesthetic feldspathic ceramics used in CAD-CAM chairside restorations. Forty eight feldspatic ceramic test specimens were prepared from prefabricated CAD-CAM blocks by using a slow speed diamond saw. Test specimens were prepared and divided into 4 groups (n = 12). In the control group, no surface treatments were applied on the feldspathic ceramic surfaces. In the hydrofluoric acid group, the bonding surfaces of feldspathic ceramics were etched with 9.5 % hydrofluoric acid. In the sandblasting group the feldspathic ceramic surfaces were air-abraded with 30-μm alumium oxide (Al2O3) particles and Er:YAG laser was used to irradiate the ceramic surfaces. The incident light power given by the LED device and the transmitted light power through each ceramic sample was registered using a digital LED radiometer device. Each polymerization light had a light guide with 8-mm-diameter tips. Light transmission of feldspathic ceramic samples was determined by placing it on the radiometer and irradiating the specimen for 10 s at the highest setting for each light polymerization. All specimens were coated with gold using a sputter coater and examined under a field emission scanning electron microscope. Surface roughness measurement each group were evaluated with 3D optical surface and tactile profilometers. One-way ANOVA test results revealed that both surface conditioning method significantly affect the light transmittance (F:412.437; p ceramic material below the value of 400 mW/cm(2) which is critical limit for safe polymerization.

Dynamics of Wetting of Ultra Hydrophobic Surfaces

Science.gov (United States)

Mohammad Karim, Alireza; Kim, Jeong-Hyun; Rothstein, Jonathan; Kavehpour, Pirouz; Mechanical and Industrial Engineering, University of Massachusetts, Amherst Collaboration

2013-11-01

Controlling the surface wettability of hydrophobic and super hydrophobic surfaces has extensive industrial applications ranging from coating, painting and printing technology and waterproof clothing to efficiency increase in power and water plants. This requires enhancing the knowledge about the dynamics of wetting on these hydrophobic surfaces. We have done experimental investigation on the dynamics of wetting on hydrophobic surfaces by looking deeply in to the dependency of the dynamic contact angles both advancing and receding on the velocity of the three-phase boundary (Solid/Liquid/Gas interface) using the Wilhelmy plate method with different ultra-hydrophobic surfaces. Several fluids with different surface tension and viscosity are used to study the effect of physical properties of liquids on the governing laws.

Design Options to Reduce Development Cost of First Generation Surface Reactors

International Nuclear Information System (INIS)

Poston, David I.; Marcille, Thomas F.

2006-01-01

Low-power surface reactors have the potential to have the lowest development cost of any space reactor application, primarily because system alpha (mass/kg) is not of utmost importance and mission lifetimes do not have to be a decade or more. Even then, the development cost of a surface reactor can vary substantially depending on the performance requirements (e.g. mass, power, lifetime, reliability) and technical development risk deemed acceptable by the end-user. It is important for potential users to be aware of these relationships before they determine their future architecture (i.e. decide what they need). Generally, the greatest potential costs of a space reactor program are a nuclear-powered ground test and extensive material development campaigns, so it is important to consider options that can minimize the need for or complexity of such tasks. The intended goal of this paper is to inform potential surface reactor users of the potential sensitivities of surface reactor development cost to design requirements, and areas where technical risk can be traded with development cost

Stochastic techno-economic assessment based on Monte Carlo simulation and the Response Surface Methodology: The case of an innovative linear Fresnel CSP (concentrated solar power) system

International Nuclear Information System (INIS)

Bendato, Ilaria; Cassettari, Lucia; Mosca, Marco; Mosca, Roberto

2016-01-01

Combining technological solutions with investment profitability is a critical aspect in designing both traditional and innovative renewable power plants. Often, the introduction of new advanced-design solutions, although technically interesting, does not generate adequate revenue to justify their utilization. In this study, an innovative methodology is developed that aims to satisfy both targets. On the one hand, considering all of the feasible plant configurations, it allows the analysis of the investment in a stochastic regime using the Monte Carlo method. On the other hand, the impact of every technical solution on the economic performance indicators can be measured by using regression meta-models built according to the theory of Response Surface Methodology. This approach enables the design of a plant configuration that generates the best economic return over the entire life cycle of the plant. This paper illustrates an application of the proposed methodology to the evaluation of design solutions using an innovative linear Fresnel Concentrated Solar Power system. - Highlights: • A stochastic methodology for solar plants investment evaluation. • Study of the impact of new technologies on the investment results. • Application to an innovative linear Fresnel CSP system. • A particular application of Monte Carlo simulation and response surface methodology.

Power laws for gravity and topography of Solar System bodies

Science.gov (United States)

Ermakov, A.; Park, R. S.; Bills, B. G.

2017-12-01

When a spacecraft visits a planetary body, it is useful to be able to predict its gravitational and topographic properties. This knowledge is important for determining the level of perturbations in spacecraft's motion as well as for planning the observation campaign. It has been known for the Earth that the power spectrum of gravity follows a power law, also known as the Kaula rule (Kaula, 1963; Rapp, 1989). A similar rule was derived for topography (Vening-Meinesz, 1951). The goal of this paper is to generalize the power law that can characterize the gravity and topography power spectra for bodies across a wide range of size. We have analyzed shape power spectra of the bodies that have either global shape and gravity field measured. These bodies span across five orders of magnitude in their radii and surface gravities and include terrestrial planets, icy moons and minor bodies. We have found that despite having different internal structure, composition and mechanical properties, the topography power spectrum of these bodies' shapes can be modeled with a similar power law rescaled by the surface gravity. Having empirically found a power law for topography, we can map it to a gravity power law. Special care should be taken for low-degree harmonic coefficients due to potential isostatic compensation. For minor bodies, uniform density can be assumed. The gravity coefficients are a linear function of the shape coefficients for close-to-spherical bodoes. In this case, the power law for gravity will be steeper than the power law of topography due to the factor (2n+1) in the gravity expansion (e.g. Eq. 10 in Wieczorek & Phillips, 1998). Higher powers of topography must be retained for irregularly shaped bodies, which breaks the linearity. Therefore, we propose the following procedure to derive an a priori constraint for gravity. First, a surface gravity needs to be determined assuming typical density for the relevant class of bodies. Second, the scaling coefficient of the

Powered Flight Design and Reconstructed Performance Summary for the Mars Science Laboratory Mission

Science.gov (United States)

Sell, Steven; Chen, Allen; Davis, Jody; San Martin, Miguel; Serricchio, Frederick; Singh, Gurkirpal

2013-01-01

The Powered Flight segment of Mars Science Laboratory's (MSL) Entry, Descent, and Landing (EDL) system extends from backshell separation through landing. This segment is responsible for removing the final 0.1% of the kinetic energy dissipated during EDL and culminating with the successful touchdown of the rover on the surface of Mars. Many challenges exist in the Powered Flight segment: extraction of Powered Descent Vehicle from the backshell, performing a 300m divert maneuver to avoid the backshell and parachute, slowing the descent from 85 m/s to 0.75 m/s and successfully lowering the rover on a 7.5m bridle beneath the rocket-powered Descent Stage and gently placing it on the surface using the Sky Crane Maneuver. Finally, the nearly-spent Descent Stage must execute a Flyaway maneuver to ensure surface impact a safe distance from the Rover. This paper provides an overview of the powered flight design, key features, and event timeline. It also summarizes Curiosity's as flown performance on the night of August 5th as reconstructed by the flight team.

Energy harvesting for self-powered aerostructure actuation

Science.gov (United States)

Bryant, Matthew; Pizzonia, Matthew; Mehallow, Michael; Garcia, Ephrahim

2014-04-01

This paper proposes and experimentally investigates applying piezoelectric energy harvesting devices driven by flow induced vibrations to create self-powered actuation of aerostructure surfaces such as tabs, flaps, spoilers, or morphing devices. Recently, we have investigated flow-induced vibrations and limit cycle oscillations due to aeroelastic flutter phenomena in piezoelectric structures as a mechanism to harvest energy from an ambient fluid flow. We will describe how our experimental investigations in a wind tunnel have demonstrated that this harvested energy can be stored and used on-demand to actuate a control surface such as a trailing edge flap in the airflow. This actuated control surface could take the form of a separate and discrete actuated flap, or could constitute rotating or deflecting the oscillating energy harvester itself to produce a non-zero mean angle of attack. Such a rotation of the energy harvester and the associated change in aerodynamic force is shown to influence the operating wind speed range of the device, its limit cycle oscillation (LCO) amplitude, and its harvested power output; hence creating a coupling between the device's performance as an energy harvester and as a control surface. Finally, the induced changes in the lift, pitching moment, and drag acting on a wing model are quantified and compared for a control surface equipped with an oscillating energy harvester and a traditional, static control surface of the same geometry. The results show that when operated in small amplitude LCO the energy harvester adds negligible aerodynamic drag.

Conversion of radius of curvature to power (and vice versa)

Science.gov (United States)

Wickenhagen, Sven; Endo, Kazumasa; Fuchs, Ulrike; Youngworth, Richard N.; Kiontke, Sven R.

2015-09-01

Manufacturing optical components relies on good measurements and specifications. One of the most precise measurements routinely required is the form accuracy. In practice, form deviation from the ideal surface is effectively low frequency errors, where the form error most often accounts for no more than a few undulations across a surface. These types of errors are measured in a variety of ways including interferometry and tactile methods like profilometry, with the latter often being employed for aspheres and general surface shapes such as freeforms. This paper provides a basis for a correct description of power and radius of curvature tolerances, including best practices and calculating the power value with respect to the radius deviation (and vice versa) of the surface form. A consistent definition of the sagitta is presented, along with different cases in manufacturing that are of interest to fabricators and designers. The results make clear how the definitions and results should be documented, for all measurement setups. Relationships between power and radius of curvature are shown that allow specifying the preferred metric based on final accuracy and measurement method. Results shown include all necessary equations for conversion to give optical designers and manufacturers a consistent and robust basis for decision-making. The paper also gives guidance on preferred methods for different scenarios for surface types, accuracy required, and metrology methods employed.

DETERMINATION AND ANALYSIS OF CHANGE POWER CHARACTER AND POWER PARAMETERS OF EARTHMOVING- TRANSPORT WORKING PROCESS MACHINES OF CYCLIC ACTION

Directory of Open Access Journals (Sweden)

KHMARA L. A.

2017-05-01

Full Text Available Summary. Raising of problem. Efficiency of implementation working process an earthmoving-transport machine on digging of soil depends on complete realization of power equipment and hauling properties working equipment during implementation this operation. Most effective will be the mode of digging when from his beginning to the final stage a power equipment will realize nominal power, and working equipment maximal KKD at that skidding of mover does not exceed the defined possible value. However, for the traditional constructions of earthmoving-transport machines cyclic action, for such, as a drag shovel, bulldozer, realizing these terms is heavy. The feature of process digging consists in the increase of resistance to digging soil from the ego of the initial stage to eventual when hauling possibilities of machine will be maximally realized. Therefore the calculation of power equipment takes into account the power indexes of machine on the final stage of digging. Thus the unstationarity of working process results in the under exploitation of power equipment machine and hereupon appearance her bits and pieces. The size of bits and pieces power depends on the stage digging of soil, his physical and mechanical properties, terms cooperation of working equipment with the surface of motion. One of methods realization surplus power, this use it for the drive intensifiers working process of earthmoving-transport machines. Therefore for the effective choice parameters of intensifier, his office hours it is necessary to know the size of bits and pieces of power and character her change during digging of soil. The purpose of the article. Development of methodology determination remaining power equipment an earthmoving-transport machine on the example self-propelled drags hovel, character her change at digging of soil taking into account physical and mechanical properties of soil and terms cooperation working equipment with the surface of motion. Conclusion

Two dimensional simulation of high power laser-surface interaction

International Nuclear Information System (INIS)

Goldman, S.R.; Wilke, M.D.; Green, R.E.L.; Johnson, R.P.; Busch, G.E.

1998-01-01

For laser intensities in the range of 10 8 --10 9 W/cm 2 , and pulse lengths of order 10 microsec or longer, the authors have modified the inertial confinement fusion code Lasnex to simulate gaseous and some dense material aspects of the laser-matter interaction. The unique aspect of their treatment consists of an ablation model which defines a dense material-vapor interface and then calculates the mass flow across this interface. The model treats the dense material as a rigid two-dimensional mass and heat reservoir suppressing all hydrodynamic motion in the dense material. The computer simulations and additional post-processors provide predictions for measurements including impulse given to the target, pressures at the target interface, electron temperatures and densities in the vapor-plasma plume region, and emission of radiation from the target. The authors will present an analysis of some relatively well diagnosed experiments which have been useful in developing their modeling. The simulations match experimentally obtained target impulses, pressures at the target surface inside the laser spot, and radiation emission from the target to within about 20%. Hence their simulational technique appears to form a useful basis for further investigation of laser-surface interaction in this intensity, pulse-width range. This work is useful in many technical areas such as materials processing

Aggregated wind power generation probabilistic forecasting based on particle filter

International Nuclear Information System (INIS)

Li, Pai; Guan, Xiaohong; Wu, Jiang

2015-01-01

Highlights: • A new method for probabilistic forecasting of aggregated wind power generation. • A dynamic system is established based on a numerical weather prediction model. • The new method handles the non-Gaussian and time-varying wind power uncertainties. • Particle filter is applied to forecast predictive densities of wind generation. - Abstract: Probability distribution of aggregated wind power generation in a region is one of important issues for power system daily operation. This paper presents a novel method to forecast the predictive densities of the aggregated wind power generation from several geographically distributed wind farms, considering the non-Gaussian and non-stationary characteristics in wind power uncertainties. Based on a mesoscale numerical weather prediction model, a dynamic system is established to formulate the relationship between the atmospheric and near-surface wind fields of geographically distributed wind farms. A recursively backtracking framework based on the particle filter is applied to estimate the atmospheric state with the near-surface wind power generation measurements, and to forecast the possible samples of the aggregated wind power generation. The predictive densities of the aggregated wind power generation are then estimated based on these predicted samples by a kernel density estimator. In case studies, the new method presented is tested on a 9 wind farms system in Midwestern United States. The testing results that the new method can provide competitive interval forecasts for the aggregated wind power generation with conventional statistical based models, which validates the effectiveness of the new method

Motor unit number index (MUNIX) derivation from the relationship between the area and power of surface electromyogram: a computer simulation and clinical study

Science.gov (United States)

Miralles, Francesc

2018-06-01

Objective. The motor unit number index (MUNIX) is a technique based on the surface electromyogram (sEMG) that is gaining acceptance as a method for monitoring motor neuron loss, because it is reliable and produces less discomfort than other electrodiagnostic techniques having the same intended purpose. MUNIX assumes that the relationship between the area of sEMG obtained at increasing levels of muscle activation and the values of a variable called ‘ideal case motor unit count’ (ICMUC), defined as the product of the ratio between area and power of the compound muscle action potential (CMAP) by that of the sEMG, is described by a decreasing power function. Nevertheless, the reason for this comportment is unknown. The objective of this work is to investigate if the definition of MUNIX could derive from more basic properties of the sEMG. Approach. The CMAP and sEMG epochs obtained at different levels of muscle activation from (1) the abductor pollicis brevis (APB) muscle of persons with and without a carpal tunnel syndrome (CTS) and (2) from a computer model of sEMG generation previously published were analysed. Main results. MUNIX reflects the power relationship existing between the area and power of a sEMG. The exponent of this function was smaller in patients with motor CTS than in the rest of the subjects. The analysis of the relationship between the area and power of a sEMG could aid in distinguishing a MUNIX reduction due to a motoneuron loss from that due to a loss of muscle fibre. Significance. MUNIX is derived from the relationship between the area and power of a sEMG. This relationship changes when there is a loss of motor units (MUs), which partially explains the diagnostic sensibility of MUNIX. Although the reasons for this change are unknown, it could reflect an increase in the proportion of MUs of great amplitude.

Estimation of wind power potential of the Gulf of Finland

DEFF Research Database (Denmark)

Monzikova, Anna K.; Kudryavtsev, V.N.; Larsen, Søren Ejling

2013-01-01

boundary layer. Calculations of the wind power potential take into account effect of the atmospheric stratification over the water surface and peculiarities of the surface roughness in the presence of ice cover. Evaluations of the number of wind turbines needed to «replace» electricity production......An assessment of wind power potential of the eastern part of the Gulf of Finland and its seasonal variations are presented. Measurements taken from meteorological stations around the coastline are used as the input data. Calculations are based on the similarity theory for the atmospheric planetary...

30 GHz High Power Production for CLIC

CERN Document Server

Syratchev, I V

2006-01-01

The CLIC Power Extraction and Transfer Structure (PETS) is a passive microwave device in which bunches of the drive beam interact with the impedance of the periodically loaded waveguide and excite preferentially the synchronous TM01 mode at 30 GHz. The RF power produced (several hundred MW) is collected at the downstream end of the structure by means of the Power Extractor and conveyed to the main linac structure. The PETS geometry is a result of multiple compromises between beam stability along a single decelerator sector (600 m) and the active length of the structure to match the main linac RF power needs and layout. Surface electric and magnetic fields, power extraction method, HOM damping, ON/OFF capability and fabrication technology were all evaluated to provide a reliable design.

Design Considerations and Conceptual Designs for Surface Nuclear Power Systems for the Moon and Mars

International Nuclear Information System (INIS)

Blessing, David L.; Kirkland, Joel

2006-01-01

A set of design considerations is proposed for nuclear power systems to provide power on the Moon or Mars. Setting the initial requirements is extremely important since they govern the choices that determine the final design. In addition, the choice of reactor and its operating conditions depends on details of the energy conversion and heat rejection systems, which must be studied in tandem. Refractory materials are not suitable for the primary pressure boundary for the reactor due to their susceptibility to chemical attack from particles of regolith on the Moon and Mars or by the carbon dioxide atmosphere on Mars. High nickel superalloys would be acceptable in these environments, but their limited creep strength at elevated temperatures limits reactor outlet temperature to about 1150 K or less. This temperature restriction results in the mass of a gas cooled reactor coupled to a Brayton power conversion system being somewhat lighter than that of a liquid metal-cooled reactors coupled to a Brayton power conversion system. The mass of a liquid metal-cooled reactor coupled to an advanced Stirling power conversion system would be in between that of the gas and liquid metal cooled systems which use Brayton power conversion

Indian Ocean surface winds from NCMRWF analysis as compared to ...

Indian Academy of Sciences (India)

R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

The quality of the surface wind analysis at the National Centre for Medium Range Weather Fore- casts (NCMRWF), New .... mization of a generalized cost function using the. Spectral ... power from a given location on the sea surface at multiple ...

Water Vapour Propulsion Powered by a High-Power Laser-Diode

Science.gov (United States)

Minami, Y.; Uchida, S.

Most of the laser propulsion schemes now being proposed and developed assume neither power supplies nor on-board laser devices and therefore are bound to remote laser stations like a kite via a laser beam “string”. This is a fatal disadvantage for a space vehicle that flies freely though it is often said that no need of installing an energy source is an advantage of a laser propulsion scheme. The possibility of an independent laser propulsion space vehicle that carries a laser source and a power supply on board is discussed. This is mainly due to the latest development of high power laser diode (LD) technology. Both high specific impulse-low thrust mode and high thrust-low specific impulse mode can be selected by controlling the laser output by using vapour or water as a propellant. This mode change can be performed by switching between a high power continuous wave (cw), LD engine for high thrust with a low specific impulse mode and high power LD pumping Q-switched Nd:YAG laser engine for low thrust with the high specific impulse mode. This paper describes an Orbital Transfer Vehicle equipped with the above-mentioned laser engine system and fuel cell that flies to the Moon from a space platform or space hotel in Earth orbit, with cargo shipment from lunar orbit to the surface of the Moon, including the possibility of a sightseeing trip.

Power transport to the PDX scoop limiter

International Nuclear Information System (INIS)

Kugel, H.W.; Bol, K.; Budny, R.

1986-07-01

Power transport to the PDX graphite scoop limiter was measured during both ohmic- and neutral-beam-heated discharges by observing its front face temperatures using an infrared camera. Measurements were made as a function of plasma density, current, position, fueling mode, and heating power for both co- and counter-neutral beam injection. The measured thermal load on the scoop limiter was 25 to 50% of the total plasma heating power. The measured peak front face midplane temperature was 1500 0 C corresponding to a peak surface power density of 3 kW/cm 2 . This power density implies an effective parallel power flow of 54 kW/cm 2 in agreement with the radial power distribution extrapolated from TVTS and calorimetry measurements. Symmetric and asymmetric thermal loads were observed. The asymmetric heat loads were predominantly skewed toward the respective ion drift directions for both co- and counter-injected beams. The results of transport calculations are consistent with the direction and magnitude of the observed asymmetries

Discrete Curvatures and Discrete Minimal Surfaces

KAUST Repository

Sun, Xiang

2012-06-01

This thesis presents an overview of some approaches to compute Gaussian and mean curvature on discrete surfaces and discusses discrete minimal surfaces. The variety of applications of differential geometry in visualization and shape design leads to great interest in studying discrete surfaces. With the rich smooth surface theory in hand, one would hope that this elegant theory can still be applied to the discrete counter part. Such a generalization, however, is not always successful. While discrete surfaces have the advantage of being finite dimensional, thus easier to treat, their geometric properties such as curvatures are not well defined in the classical sense. Furthermore, the powerful calculus tool can hardly be applied. The methods in this thesis, including angular defect formula, cotangent formula, parallel meshes, relative geometry etc. are approaches based on offset meshes or generalized offset meshes. As an important application, we discuss discrete minimal surfaces and discrete Koenigs meshes.

Intelligent Sun Tracking for a CPV Power Plant

International Nuclear Information System (INIS)

Maqsood, Ishtiaq; Emziane, Mahieddine

2010-01-01

The output of a solar panel is strongly dependent on the amount of perpendicular light flux falling on its surface, and a tracking system tries to parallel the vector area of the solar panel surface to the incident solar flux. We present a tracking technique based on a two-axis sun sensor which can be used to increase the power output from a number of CPV arrays connected together in a solar power plant. The outdoor testing procedure of the developed two-axis sun sensor is discussed. The detail of the algorithm used together with the related sun tracking equipment is also presented and discussed for the new two axes sun tracking system.

Microstructure and surface morphology of YSZ thin films deposited by e-beam technique

International Nuclear Information System (INIS)

Laukaitis, G.; Dudonis, J.; Milcius, D.

2008-01-01

In present study yttrium-stabilized zirconia (YSZ) thin films were deposited on optical quartz (amorphous SiO 2 ), porous Ni-YSZ and crystalline Alloy 600 (Fe-Ni-Cr) substrates using e-beam deposition technique and controlling technological parameters: substrate temperature and electron gun power which influence thin-film deposition mechanism. X-ray diffraction, scanning electron microscopy (SEM), and atomic force microscopy (AFM) were used to investigate how thin-film structure and surface morphology depend on these parameters. It was found that the crystallite size, roughness and growth mechanism of YSZ thin films are influenced by electron gun power. To clarify the experimental results, YSZ thin-film formation as well evolution of surface roughness at its initial growing stages were analyzed. The evolution of surface roughness could be explained by the processes of surface mobility of adatoms and coalescence of islands. The analysis of these experimental results explain that surface roughness dependence on substrate temperature and electron gun power non-monotonous which could result from diffusivity of adatoms and the amount of atomic clusters in the gas stream of evaporated material

RF atmospheric plasma jet surface treatment of paper

Science.gov (United States)

Pawlat, Joanna; Terebun, Piotr; Kwiatkowski, Michał; Diatczyk, Jaroslaw

2016-09-01

A radio frequency RF atmospheric pressure plasma jet was used to enhance the wettability of cellulose-based paper of 90 g m-2 and 160 g m-2 grammage as a perspective platform for antibiotic sensitivity tests. Helium and argon were the carrier gases for oxygen and nitrogen; pure water and rapeseed oil were used for goniometric tests. The influence of the flow rate and gas type, the power of the discharge, and distance from the nozzle was examined. The surface structure was observed using an optical microscope. Attenuated total reflection Fourier transform infrared (ATR-FTIR) spectra were investigated in order to determine whether cellulose degradation processes occurred. The RF plasma jet allowed us to decrease the surface contact angle without drastic changes in other features of the tested material. Experiments confirmed the significant influence of the distance between the treated sample and reactor nozzle, especially for treatment times longer than 15 s due to the greater concentration of reactive species at the surface of the sample, which decreases with distance—and their accumulation effect with time. The increase of discharge power plays an important role in decreasing the surface contact angle for times longer than 10 s. Higher power had a positive effect on the amount of generated active particles and facilitated the ignition of discharge. However, a too high value can cause a rise in temperature of the material and heat-caused damage.

Development of mechanization of extraction in underground coal mining (part I)

Energy Technology Data Exchange (ETDEWEB)

Strzeminski, J

1984-01-01

The history of underground coal mining and history of mechanizing underground operations of cutting, strata control, mine haulage, hoisting and ventilation are discussed. The following development periods are characterized: until 1769 (date of steam engine invention by J. Watt), from 1769 to 1945 (period of partial mechanization of operations in underground coal mining), from 1945 (period of comprehensive mechanization and automation). A general description of mining in the first development period is given. Evaluation of the second development period concentrates on mechanization in underground coal mining. The following equipment types are described: cutting (pneumatic picks and pneumatic drills, coal saws developed by Eickhoff, coal cutters developed after 1870, cutter loaders patented in 1925-1927, coal plows and coal cutter loaders), mine haulage (mine cars, conveyors developed in the United Kingdom, Germany and Russia, Poland), strata control at working faces (timber props, steel friction props, roof bars), strata control in the goaf (room and pillar mining, stowing, minestone utilization for stowing in Upper Silesia, hydraulic stowing in Upper Silesia). 5 references.

Effect of laser cutting parameters on surface roughness of stainless steel 307

Directory of Open Access Journals (Sweden)

Amal NASSAR

2016-12-01

Full Text Available Optimal parameters of laser cutting are an important step to improve surface quality of cutting edge in the laser cutting of stainless steel 307. This paper presents a new approach for optimizing the cutting parameters on stainless steel. Based on 33 full factorial experimental design, cutting experiments were conducted for stainless steel 307 plates using a laser machine (AMADA FONT 3015. The cutting parameters such as, cutting speed, cutting power and gas pressure are optimized for maximizing surface quality. The results indicated that cutting power and cutting speed play an important role in surface quality.

Separation of surface, subsurface and volume fatigue damage effects in AISI 348 steel for power plant applications

Energy Technology Data Exchange (ETDEWEB)

Klein, Martin; Nowak, David; Walther, Frank [Technical Univ. Dortmund (Germany). Dept. of Materials Test Engineering (WPT); Starke, Peter [Saarland Univ., Saarbruecken (Germany). Chair of Non-Destructive Testing and Quality Assurance; Boller, Christian [Saarland Univ., Saarbruecken (Germany). Chair of Non-Destructive Testing and Quality Assurance; Fraunhofer IZFP, Saarbruecken (Germany)

2016-08-01

A wide range of industries including energy, chemistry, pharmacy, textiles, food and drink, pulp and paper, etc. is using stainless steels. Metastable austenitic steels such as used in power plants and chemical industry are subjected to cyclic mechanical and thermal loading in air as well as under the influence of corrosive media. This paper provides an overview on different nondestructive and electrochemical measurement techniques, which allow differentiating fatigue damage effects in total strain controlled multiple and constant amplitude tests with respect to damage appearance on surface, in subsurface area as well as in volume of specimens or components microstructure. In addition to conventional mechanical stress-strain hysteresis curves, electrical resistance, magnetic and open circuit potential measurements have been applied to characterize the cyclic deformation behavior of the metastable austenitic steel AISI 348 (X10CrNiNb18-9) in laboratory air and in distilled water. Based on these results obtained, the paper provides an outlook on the possibility for an efficient (remaining) fatigue life evaluation approach, which is adapted to the needs of the application areas.

Life cycle analysis of geothermal power generation with supercritical carbon dioxide

International Nuclear Information System (INIS)

Frank, Edward D; Sullivan, John L; Wang, Michael Q

2012-01-01

Life cycle analysis methods were employed to model the greenhouse gas emissions and fossil energy consumption associated with geothermal power production when supercritical carbon dioxide (scCO 2 ) is used instead of saline geofluids to recover heat from below ground. Since a significant amount of scCO 2 is sequestered below ground in the process, a constant supply is required. We therefore combined the scCO 2 geothermal power plant with an upstream coal power plant that captured a portion of its CO 2 emissions, compressed it to scCO 2 , and transported the scCO 2 by pipeline to the geothermal power plant. Emissions and energy consumption from all operations spanning coal mining and plant construction through power production were considered, including increases in coal use to meet steam demand for the carbon capture. The results indicated that the electricity produced by the geothermal plant more than balanced the increase in energy use resulting from carbon capture at the coal power plant. The effective heat rate (BTU coal per total kW h of electricity generated, coal plus geothermal) was comparable to that of traditional coal, but the ratio of life cycle emissions from the combined system to that of traditional coal was 15% when 90% carbon capture efficiency was assumed and when leakage from the surface was neglected. Contributions from surface leakage were estimated with a simple model for several hypothetical surface leakage rates. (letter)

Impact of initial surface parameters on the final quality of laser micro-polished surfaces

Science.gov (United States)

Chow, Michael; Bordatchev, Evgueni V.; Knopf, George K.

2012-03-01

Laser micro-polishing (LμP) is a new laser-based microfabrication technology for improving surface quality during a finishing operation and for producing parts and surfaces with near-optical surface quality. The LμP process uses low power laser energy to melt a thin layer of material on the previously machined surface. The polishing effect is achieved as the molten material in the laser-material interaction zone flows from the elevated regions to the local minimum due to surface tension. This flow of molten material then forms a thin ultra-smooth layer on the top surface. The LμP is a complex thermo-dynamic process where the melting, flow and redistribution of molten material is significantly influenced by a variety of process parameters related to the laser, the travel motions and the material. The goal of this study is to analyze the impact of initial surface parameters on the final surface quality. Ball-end micromilling was used for preparing initial surface of samples from H13 tool steel that were polished using a Q-switched Nd:YAG laser. The height and width of micromilled scallops (waviness) were identified as dominant parameter affecting the quality of the LμPed surface. By adjusting process parameters, the Ra value of a surface, having a waviness period of 33 μm and a peak-to-valley value of 5.9 μm, was reduced from 499 nm to 301 nm, improving the final surface quality by 39.7%.

Solar-Powered Plasmon-Enhanced Heterogeneous Catalysis

Directory of Open Access Journals (Sweden)

Naldoni Alberto

2016-06-01

Full Text Available Photocatalysis uses semiconductors to convert sunlight into chemical energy. Recent reports have shown that plasmonic nanostructures can be used to extend semiconductor light absorption or to drive direct photocatalysis with visible light at their surface. In this review, we discuss the fundamental decay pathway of localized surface plasmons in the context of driving solar-powered chemical reactions. We also review different nanophotonic approaches demonstrated for increasing solar-to-hydrogen conversion in photoelectrochemical water splitting, including experimental observations of enhanced reaction selectivity for reactions occurring at the metalsemiconductor interface. The enhanced reaction selectivity is highly dependent on the morphology, electronic properties, and spatial arrangement of composite nanostructures and their elements. In addition, we report on the particular features of photocatalytic reactions evolving at plasmonic metal surfaces and discuss the possibility of manipulating the reaction selectivity through the activation of targeted molecular bonds. Finally, using solar-to-hydrogen conversion techniques as an example, we quantify the efficacy metrics achievable in plasmon-driven photoelectrochemical systems and highlight some of the new directions that could lead to the practical implementation of solar-powered plasmon-based catalytic devices.

Valves and fittings for nuclear power stations

International Nuclear Information System (INIS)

1976-01-01

The standard specifies technical requirements for valves and pipe fittings in nuclear power stations with PWR type reactors. Details of appropriate materials, welding, surface treatment for corrosion protection, painting, and complementary supply are given

Results of Steam-Water-Oxygen Treatment of the Inside of Heating Surfaces in Heat-Recovery Steam Generators of the PGU-800 Power Unit at the Perm' District Thermal Power Station

Science.gov (United States)

Ovechkina, O. V.; Zhuravlev, L. S.; Drozdov, A. A.; Solomeina, S. V.

2018-05-01

Prestarting, postinstallation steam-water-oxygen treatment (SWOT) of the natural circulation/steam reheat heat-recovery steam generators (HRSG) manufactured by OAO Krasny Kotelshchik was performed at the PGU-800 power unit of the Perm District Thermal Power Station (GRES). Prior to SWOT, steam-oxygen cleaning, passivation, and preservation of gas condensate heaters (GCH) of HRSGs were performed for 10 h using 1.3MPa/260°C/70 t/h external steam. After that, test specimens were cut out that demonstrated high strength of the passivating film. SWOT of the inside of the heating surfaces was carried out during no-load operation of the gas turbine unit with an exhaust temperature of 280-300°C at the HRSG inlet. The steam turbine was shutdown, and the generated steam was discharged into the atmosphere. Oxygen was metered into the discharge pipeline of the electricity-driven feed pumps and downcomers of the evaporators. The behavior of the concentration by weight of iron compounds and the results of investigation of cutout specimens by the drop or potentiometric method indicate that the steam-water-oxygen process makes it possible to remove corrosion products and reduce the time required to put a boiler into operation. Unlike other processes, SWOT does not require metal-intensive cleaning systems, temporary metering stations, and structures for collection of the waste solution.

Flow profiling of a surface-acoustic-wave nanopump

Science.gov (United States)

Guttenberg, Z.; Rathgeber, A.; Keller, S.; Rädler, J. O.; Wixforth, A.; Kostur, M.; Schindler, M.; Talkner, P.

2004-11-01

The flow profile in a capillary gap and the pumping efficiency of an acoustic micropump employing surface acoustic waves is investigated both experimentally and theoretically. Ultrasonic surface waves on a piezoelectric substrate strongly couple to a thin liquid layer and generate a quadrupolar streaming pattern within the fluid. We use fluorescence correlation spectroscopy and fluorescence microscopy as complementary tools to investigate the resulting flow profile. The velocity was found to depend on the applied power approximately linearly and to decrease with the inverse third power of the distance from the ultrasound generator on the chip. The found properties reveal acoustic streaming as a promising tool for the controlled agitation during microarray hybridization.

Indirect drive targets for fusion power

Energy Technology Data Exchange (ETDEWEB)

Amendt, Peter A.; Miles, Robin R.

2016-10-11

A hohlraum for an inertial confinement fusion power plant is disclosed. The hohlraum includes a generally cylindrical exterior surface, and an interior rugby ball-shaped surface. Windows over laser entrance holes at each end of the hohlraum enclose inert gas. Infrared reflectors on opposite sides of the central point reflect fusion chamber heat away from the capsule. P2 shields disposed on the infrared reflectors help assure an enhanced and more uniform x-ray bath for the fusion fuel capsule.

Corrosion behaviour of laser surface melted magnesium alloy AZ91D

International Nuclear Information System (INIS)

Taltavull, C.; Torres, B.; Lopez, A.J.; Rodrigo, P.; Otero, E.; Atrens, A.; Rams, J.

2014-01-01

A high power diode laser (HPDL) was used to produce laser surface melting (LSM) treatments on the surface of the Mg alloy AZ91D. Different treatments with different microstructures were produced by varying the laser-beam power and laser-scanning speed. Corrosion evaluation, using hydrogen evolution and electrochemical measurements, led to a relationship between microstructure and corrosion. Most corrosion rates for LSM treated specimens were within the scatter of the as-received AZ91D, whereas some treatments gave higher corrosion rates and some of the samples had corrosion rates lower than the average of the corrosion rate for AZ91D. There were differences in corroded surface morphology. Nevertheless laser treatments introduced surface discontinuities, which masked the effect of the microstructure. Removing these surface defects decreased the corrosion rate for the laser-treated samples. - Highlights: • Corrosion behavior of AZ91D Mg alloys is intimately related with its microstructure. • Laser surface melting treatments allows surface modification of the microstructure. • Different laser parameters can achieve different microstructures. • Controlling laser parameters can produce different corrosion rates and morphologies. • Increase of surface roughness due to laser treatment is relevant to the corrosion rate

Energy loss spectroscopy applied to surface studies

International Nuclear Information System (INIS)

Lecante, J.

1975-01-01

The analysis of energy losses suffered by slow electrons (5 eV to 300 eV) back-scattered by single crystal surfaces appears to be a powerful method for surfaces studies. The inelastic scattering of these slow electrons limits their escape depth to the surface region which is defined here. After a review of the basic excitation processes due to the interaction between electrons and surfaces (phonons, plasmons and electronic transitions) a brief discussion is given about the instruments needed for this electron spectroscopy. Finally some experimental results are listed and it is shown that the comparison of the results given by ELS with other surface sensitive methods such as UPS is very fruitful and new information can be obtained [fr

Laser surface cleaning

International Nuclear Information System (INIS)

Freiwald, J.G.; Freiwald, D.A.

1994-01-01

The objective of this work is a laboratory demonstration that red-lead primer and two-part epoxy paints can be stripped from concrete and metal surfaces using surface cleaning systems based on pulsed-repetition CO 2 lasers. The three goals are to: (1) demonstrate coatings removal, including surface pore cleaning; (2) demonstrate that there is negligible release of ablated contaminants to the environment; and (3) demonstrate that the process will generate negligible amounts of additional waste compared to competing technologies. Phase 1 involved site visits to RMI and Fernald to assess the cleaning issues for buildings and parts. In addition, Phase 1 included detailed designs of a more powerful system for industrial cleaning rates, including laser, articulating optics, ablated-material capture suction nozzle attached to a horizontal raster scanner for floor cleaning, and filtration system. Some concept development is also being done for using robots, and for parts cleaning. In Phase 2 a transportable 6 kW system will be built and tested, with a horizontal surface scanner for cleaning paint from floors. The laboratory tests will again be instrumented. Some concept development will continue for using robots, and for parts cleaning. This report describes Phase 1 results

Electrostatic protection of the Solar Power Satellite and rectenna

Science.gov (United States)

Freeman, J. W.; Few, A. A., Jr.; Reiff, P. H.; Cooke, D.; Bohannon, J.; Haymes, B.

1979-01-01

Several features of the interactions of the solar power satellite (SPS) with its space environment were examined theoretically. The voltages produced at various surfaces due to space plasmas and the plasma leakage currents through the kapton and sapphire solar cell blankets were calculated. At geosynchronous orbit, this parasitic power loss is only 0.7%, and is easily compensated by oversizing. At low-Earth orbit, the power loss is potentially much larger (3%), and anomalous arcing is expected for the EOTV high voltage negative surfaces. Preliminary results of a three dimensional self-consistent plasma and electric field computer program are presented, confirming the validity of the predictions made from the one dimensional models. Magnetic shielding of the satellite, to reduce the power drain and to protect the solar cells from energetic electron and plasma ion bombardment is considered. It is concluded that minor modifications can allow the SPS to operate safely and efficiently in its space environment. The SPS design employed in this study is the 1978 MSFC baseline design utilizing GaAs solar cells at CR-2 and an aluminum structure.

Histological Evaluation of Nano-Micro Titanium Implant Surface Treatment in Beagle Humerus.

Science.gov (United States)

Yun, Kwidug; Kang, Seongsoo; Oh, Gyejeong; Lim, Hyunpil; Lee, Kwangmin; Yang, Hongso; Vang, Mongsook; Park, Sangwon

2016-02-01

The objective of this study was to investigate the effects of nano-micro titanium implant surface using histology in beagle dogs. A total of 48 screw-shaped implants (Megagen, Daegu, Korea) which dimensions were 4 mm in diameter and 8.5 mm in length, were used. The implants were classified into 4 groups (n = 12): machined surface (M group), RBM (Resorbable Blasting Media) surface (R group), nano surface which is nanotube formation on the machined surface (MA group) and nano-micro surface which is nanotube formation on the RBM surface (RA group). Anodic oxidation was performed at a constant voltage of 20 V for 10 min using a DC power supply (Fine Power F-3005; SG EMD, Anyang, Korea). The bone blocks were investigated using histology. There was no inflammation around implants, and new bone formation was shown along with the nano-micro titanium implant surfaces. The amount of bone formation was increased depending on time comparing 4 weeks and 12 weeks. At 12 weeks, lamellar bone was more formed along with the nano-micro titanium implant surfaces than 4 weeks. It indicated that nano-micro surface showed good result in terms of osseointegration.

Atmospheric pressure plasma jet's characterization and surface wettability driven by neon transformer

Science.gov (United States)

Elfa, R. R.; Nafarizal, N.; Ahmad, M. K.; Sahdan, M. Z.; Soon, C. F.

2017-03-01

Atmospheric pressure plasma driven by Neon transformer power supply argon is presented in this paper. Atmospheric pressure plasma system has attracted researcher interest over low pressure plasma as it provides a flexibility process, cost-efficient, portable device and vacuum-free device. Besides, another golden key of this system is the wide promising application in the field of work cover from industrial and engineering to medical. However, there are still numbers of fundamental investigation that are necessary such as device configuration, gas configuration and its effect. Dielectric barrier discharge which is also known as atmospheric pressure plasma discharge is created when there is gas ionization process occur which enhance the movement of atom and electron and provide energetic particles. These energetic particles can provide modification and cleaning property to the sample surface due to the bombardment of the high reactive ion and radicals to the sample surface. In order to develop atmospheric pressure plasma discharge, a high voltage and high frequency power supply is needed. In this work, we used a neon transformer power supply as the power supply. The flow of the Ar is feed into 10 mm cylinder quartz tube with different treatment time in order to investigate the effect of the plasma discharge. The analysis of each treatment time is presented by optical emission spectroscopy (OES) and water contact angle (WCA) measurement. The increase of gas treatment time shows increases intensity of reactive Ar and reduces the angle of water droplets in water contact angle. Treatment time of 20 s microslide glass surface shows that the plasma needle discharges have modified the sample surface from hydrophilic surface to superhydrophilic surface. Thus, this leads to another interesting application in reducing sample surface adhesion to optimize productivity in the industry of paintings, semiconductor and more.

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

Advanced underground Vehicle Power and Control: The locomotive Research Platform

Energy Technology Data Exchange (ETDEWEB)

Vehicle Projects LLC

2003-01-28

Develop a fuelcell mine locomotive with metal-hydride hydrogen storage. Test the locomotive for fundamental limitations preventing successful commercialization of hydride fuelcells in underground mining. During Phase 1 of the DOE-EERE sponsored project, FPI and its partner SNL, completed work on the development of a 14.4 kW fuelcell power plant and metal-hydride energy storage. An existing battery-electric locomotive with similar power requirements, minus the battery module, was used as the base vehicle. In March 2001, Atlas Copco Wagner of Portland, OR, installed the fuelcell power plant into the base vehicle and initiated integration of the system into the vehicle. The entire vehicle returned to Sandia in May 2001 for further development and integration. Initial system power-up took place in December 2001. A revision to the original contract, Phase 2, at the request of DOE Golden Field Office, established Vehicle Projects LLC as the new prime contractor,. Phase 2 allowed industry partners to conduct surface tests, incorporate enhancements to the original design by SNL, perform an extensive risk and safety analysis, and test the fuelcell locomotive underground under representative production mine conditions. During the surface tests one of the fuelcell stacks exhibited reduced power output resulting in having to replace both fuelcell stacks. The new stacks were manufactured with new and improved technology resulting in an increase of the gross power output from 14.4 kW to 17 kW. Further work by CANMET and Hatch Associates, an engineering consulting firm specializing in safety analysis for the mining industry, both under subcontract to Vehicle Projects LLC, established minimum requirements for underground testing. CANMET upgraded the Programmable Logic Control (PLC) software used to monitor and control the fuelcell power plant, taking into account locomotive operator's needs. Battery Electric, a South Africa manufacturer, designed and manufactured (at no cost

Investigation of the characteristics of atmospheric pressure surface barrier discharges

International Nuclear Information System (INIS)

Zhang Rui; Zhan Rujuan; Wen Xiaohui; Wang Lei

2003-01-01

Experiments were performed on atmospheric pressure surface barrier discharges. Two types of panels were used. Both have pectinate high voltage electrodes on their upper surface, but the difference is that in type I, the grounded electrode consists of the same pectinate electrodes on the lower surface, whereas type II has an extended grounded plane electrode on the lower surface. The excitation temperature was determined from a Fermi-Dirac model and a temperature near 0.7 eV is obtained. The electron density was estimated from an electrical conductivity approach (Ohmic heating model) - an equivalent circuit model is proposed and the electron density is found to be of the order of 10 11 cm -3 . The electrical behaviour was studied, and it was found that the average power consumed in the discharge plasma increases with increasing strip width in the type I discharge, whereas it remains almost constant with increasing strip width in the type II discharge. The average discharge power remains almost constant with variation in the strip-to-strip distance. The type II discharge consumes much higher average discharge power than type I. We also find that panels with a larger height of high voltage electrodes can generate brighter and thicker discharge plasmas. The equivalent circuit model was used to interpret these phenomena

Radioisotope Stirling Engine Powered Airship for Low Altitude Operation on Venus

Science.gov (United States)

Colozza, Anthony J.

2012-01-01

The feasibility of a Stirling engine powered airship for the near surface exploration of Venus was evaluated. The heat source for the Stirling engine was limited to 10 general purpose heat source (GPHS) blocks. The baseline airship utilized hydrogen as the lifting gas and the electronics and payload were enclosed in a cooled insulated pressure vessel to maintain the internal temperature at 320 K and 1 Bar pressure. The propulsion system consisted of an electric motor driving a propeller. An analysis was set up to size the airship that could operate near the Venus surface based on the available thermal power. The atmospheric conditions on Venus were modeled and used in the analysis. The analysis was an iterative process between sizing the airship to carry a specified payload and the power required to operate the electronics, payload and cooling system as well as provide power to the propulsion system to overcome the drag on the airship. A baseline configuration was determined that could meet the power requirements and operate near the Venus surface. From this baseline design additional trades were made to see how other factors affected the design such as the internal temperature of the payload chamber and the flight altitude. In addition other lifting methods were evaluated such as an evacuated chamber, heated atmospheric gas and augmented heated lifting gas. However none of these methods proved viable.

Designing Pulse Laser Surface Modification of H13 Steel Using Response Surface Method

Science.gov (United States)

Aqida, S. N.; Brabazon, D.; Naher, S.

2011-01-01

This paper presents a design of experiment (DOE) for laser surface modification process of AISI H13 tool steel in achieving the maximum hardness and minimum surface roughness at a range of modified layer depth. A Rofin DC-015 diffusion-cooled CO2 slab laser was used to process AISI H13 tool steel samples. Samples of 10 mm diameter were sectioned to 100 mm length in order to process a predefined circumferential area. The parameters selected for examination were laser peak power, overlap percentage and pulse repetition frequency (PRF). The response surface method with Box-Behnken design approach in Design Expert 7 software was used to design the H13 laser surface modification process. Metallographic study and image analysis were done to measure the modified layer depth. The modified surface roughness was measured using two-dimensional surface profilometer. The correlation of the three laser processing parameters and the modified surface properties was specified by plotting three-dimensional graph. The hardness properties were tested at 981 mN force. From metallographic study, the laser modified surface depth was between 37 μm and 150 μm. The average surface roughness recorded from the 2D profilometry was at a minimum value of 1.8 μm. The maximum hardness achieved was between 728 and 905 HV0.1. These findings are significant to modern development of hard coatings for wear resistant applications.

30 CFR 75.1403-9 - Criteria-Shelter holes.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Criteria-Shelter holes. 75.1403-9 Section 75... Criteria—Shelter holes. (a) Shelter holes should be provided on track haulage roads at intervals of not... holes should be readily accessible and should be at least 5 feet in depth, not more than 4 feet in width...

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

Laser alloying of aluminium to improve surface properties - MSSA 2010

CSIR Research Space (South Africa)

Mabhali, Luyolo AB

2010-07-01

Full Text Available and microstructure of the surface without affecting the bulk properties of the material. The process involves melting the substrate surface and injecting the powder of the alloying material into the melt pool. Process parameters such as laser power, beam spot size...

Sulfide Mineral Surfaces

International Nuclear Information System (INIS)

Rosso, Kevin M.; Vaughan, David J.

2006-01-01

The past twenty years or so have seen dramatic development of the experimental and theoretical tools available to study the surfaces of solids at the molecular (?atomic resolution?) scale. On the experimental side, two areas of development well illustrate these advances. The first concerns the high intensity photon sources associated with synchrotron radiation; these have both greatly improved the surface sensitivity and spatial resolution of already established surface spectroscopic and diffraction methods, and enabled the development of new methods for studying surfaces. The second centers on the scanning probe microscopy (SPM) techniques initially developed in the 1980's with the first scanning tunneling microscope (STM) and atomic force microscope (AFM) experiments. The direct 'observation' of individual atoms at surfaces made possible with these methods has truly revolutionized surface science. On the theoretical side, the availability of high performance computers coupled with advances in computational modeling has provided powerful new tools to complement the advances in experiment. Particularly important have been the quantum mechanics based computational approaches such as density functional theory (DFT), which can now be easily used to calculate the equilibrium crystal structures of solids and surfaces from first principles, and to provide insights into their electronic structure. In this chapter, we review current knowledge of sulfide mineral surfaces, beginning with an overview of the principles relevant to the study of the surfaces of all crystalline solids. This includes the thermodynamics of surfaces, the atomic structure of surfaces (surface crystallography and structural stability, adjustments of atoms at the surface through relaxation or reconstruction, surface defects) and the electronic structure of surfaces. We then discuss examples where specific crystal surfaces have been studied, with the main sulfide minerals organized by structure type

Sulfide Mineral Surfaces

Energy Technology Data Exchange (ETDEWEB)

Rosso, Kevin M.; Vaughan, David J.

2006-08-01

The past twenty years or so have seen dramatic development of the experimental and theoretical tools available to study the surfaces of solids at the molecular (?atomic resolution?) scale. On the experimental side, two areas of development well illustrate these advances. The first concerns the high intensity photon sources associated with synchrotron radiation; these have both greatly improved the surface sensitivity and spatial resolution of already established surface spectroscopic and diffraction methods, and enabled the development of new methods for studying surfaces. The second centers on the scanning probe microscopy (SPM) techniques initially developed in the 1980's with the first scanning tunneling microscope (STM) and atomic force microscope (AFM) experiments. The direct 'observation' of individual atoms at surfaces made possible with these methods has truly revolutionized surface science. On the theoretical side, the availability of high performance computers coupled with advances in computational modeling has provided powerful new tools to complement the advances in experiment. Particularly important have been the quantum mechanics based computational approaches such as density functional theory (DFT), which can now be easily used to calculate the equilibrium crystal structures of solids and surfaces from first principles, and to provide insights into their electronic structure. In this chapter, we review current knowledge of sulfide mineral surfaces, beginning with an overview of the principles relevant to the study of the surfaces of all crystalline solids. This includes the thermodynamics of surfaces, the atomic structure of surfaces (surface crystallography and structural stability, adjustments of atoms at the surface through relaxation or reconstruction, surface defects) and the electronic structure of surfaces. We then discuss examples where specific crystal surfaces have been studied, with the main sulfide minerals organized by

Evaluation of broadband surface solar irradiance derived from the Ozone Monitoring Instrument

NARCIS (Netherlands)

Wang, P.; Sneep, M.; Veefkind, J.P.; Stammes, P.; Levelt, P.F.

2014-01-01

Surface solar irradiance (SSI) data are important for planning and estimating the production of solar power plants. Long-term high quality surface solar radiation data are needed for monitoring climate change. This paper presents a new surface solar irradiance dataset, the broadband (0.2–4 ?m)

Optical Estimation of the 3D Shape of a Solar Illuminated, Reflecting Satellite Surface

Science.gov (United States)

Antolin, J.; Yu, Z.; Prasad, S.

2016-09-01

The spatial distribution of the polarized component of the power reflected by a macroscopically smooth but microscopically roughened curved surface under highly directional illumination, as characterized by an appropriate bi-directional reflectance distribution function (BRDF), carries information about the three-dimensional (3D) shape of the surface. This information can be exploited to recover the surface shape locally under rather general conditions whenever power reflectance data for at least two different illumination or observation directions can be obtained. We present here two different parametric approaches for surface reconstruction, amounting to the recovery of the surface parameters that are either the global parameters of the family to which the surface is known a priori to belong or the coefficients of a low-order polynomial that can be employed to characterize a smoothly varying surface locally over the observed patch.

Power electronics solution to dust emissions from thermal power plants

Directory of Open Access Journals (Sweden)

Vukosavić Slobodan

2010-01-01

Full Text Available Thermal power stations emit significant amounts of fly ash and ultra fine particles into the atmosphere. Electrostatic precipitators (ESP or electro filters remove flying ashes and fine particles from the flue gas before passing the gas into the chimney. Maximum allowable value of dust is 50 mg/m3 and it requires that the efficiency of the ESPs better than 99 %, which calls for an increase of active surface of the electrodes, hence increasing the filter volume and the weight of steel used for the filter. In previous decades, electrostatic precipitators in thermal power plants were fed by thyristor controlled, single phase fed devices having a high degree of reliability, but with a relatively low collection efficiency, hence requiring large effective surface of the collection plates and a large weight of steel construction in order to achieve the prescribed emission limits. Collection efficiency and energy efficiency of the electrostatic precipitator can be increased by applying high frequency high voltage power supply (HF HV. Electrical engineering faculty of the University of Belgrade (ETF has developed technology and HF HV equipment for the ESP power supply. This solution was subjected to extensive experimental investigation at TE Morava from 2008 to 2010. High frequency power supply is proven to reduce emission two times in controlled conditions while increasing energy efficiency of the precipitator, compared to the conventional thyristor controlled 50Hz supply. Two high frequency high voltage unit AR70/1000 with parameters 70 kV and 1000 mA are installed at TE Morava and thoroughly testes. It was found that the HF HV power supply of the ESP at TE Morava increases collection efficiency so that emission of fine particles and flying ashes are halved, brought down to only 50 % of the emissions encountered with conventional 50 Hz thyristor driven power supplies. On the basis of this study, conclusion is drawn that the equipment comprising HF HV

Effects of surface treatments on microstructure in stainless steel

International Nuclear Information System (INIS)

Mabuchi, Yasuhiro; Tamako, Hiroaki; Kaneda, Junya; Yamashita, Norimichi; Miyakawa, Masahiko

2009-01-01

It is revealed that Stress Corrosion Cracking (SCC) on the surface of the L-grade stainless steels in Nuclear Power Plants is caused by heavily cold work of the materials. The microstructure, hardness and residual stress on the surface of the material are factors for SCC initiation. There are surface treatment methods that is effective reduction on SCC such as Flap Wheel (FW) polishing, Clean N Strip (CNS) polishing, Water Jet Peening (WJP) and Shot Peening (SP). In this paper, the characteristics of the surface cold worked layer of the L-grade stainless steels conducted by above-mentioned surface treatments are analyzed, and effects of the surface treatments on the surface layer are discussed. (author)

Fabrication of Self-Cleaning and Anti-Icing Durable Surface on Glass.

Science.gov (United States)

Zuo, Zhiping; Liao, Ruijin; Guo, Chao; Zhao, Xuetong; Zhuang, Aoyun; Yuan, Yuan

2017-01-01

Ice accumulation on insulators affected the safety of power system and may inflict serious consequences such as insulator flashover accidents and power failure. This article reported a simple method to prepare anti-icing polydimethylsiloxane superhydrophobic surface on glass by utilizing nano-particle filling method. The effect of concentration of silica nanoparticles on superhydrophobicity of the samples was investigated. The wettability, surface morphology and anti-icing property of the as-prepared superhydrophobic surface were characterized by corresponding methods. Results show that the as-prepared surface with addition amount of 7 g silica nanoparticles exhibited self-cleaning property and excellent superhydrophobicity with a contact angle of 165.7 ± 2.4° and a sliding angle of 3.8°. It was found that the ice formation was delayed for 29 min at −5 °C. Moreover, the as-prepared superhydrophobic surface showed superhydrophobicity in the pH range of 1–13 and exhibited excellent drop impact stability. The as-prepared superhydrophobic surface may be suitable for applications in cold regions owing to its flexibility, durability and anti-icing property.

Power transport to the poloidal divertor experiment scoop limiter

International Nuclear Information System (INIS)

Kugel, H.W.; Budny, R.; Fonck, R.

1987-01-01

Power transport to the Poloidal Divertor Experiment graphite scoop limiter was measured during both ohmic- and neutral-beam-heated discharges by observing its front face temperatures using an infrared camera. Measurements were made as a function of a plasma density, current, position, fueling mode, and heating power for both co- and counter-neutral beam injection. The measured thermal load on the scoop limiter was 25 to 50%. of the total plasma heating power. The measured peak front face midplane temperature was 1500 0 C, corresponding to a peak surface power density of 3 kW/cm/sup 2/. This power density implies an effective parallel power flow of 54 kW/cm/sup 2/ in agreement with the radial power distribution extrapolated from television Thomson scattering and calorimetry measurements

SURFACE FILMS TO SUPPRESS FIELD EMISSION IN HIGH-POWER MICROWAVE COMPONENTS

Energy Technology Data Exchange (ETDEWEB)

Hirshfield, Jay l

2014-02-07

Results are reported on attempts to reduce the RF breakdown probability on copper accelerator structures by applying thin surface films that could suppress field emission of electrons. Techniques for application and testing of copper samples with films of metals with work functions higher than copper are described, principally for application of platinum films, since platinum has the second highest work function of any metal. Techniques for application of insulating films are also described, since these can suppress field emission and damage on account of dielectric shielding of fields at the copper surface, and on account of the greater hardness of insulating films, as compared with copper. In particular, application of zirconium oxide films on high-field portions of a 11.424 GHz SLAC cavity structure for breakdown tests are described.

High power CO2 lasers and their applications in nuclear industry

International Nuclear Information System (INIS)

Nath, A.K.

2002-01-01

Carbon dioxide laser is one of the most popular lasers in industry for material processing applications. It has very high power capability and high efficiency, can be operated in continuous wave (CW), modulated and pulsed modes, and has relatively low cost. Due to these characteristics high power CO 2 lasers are being used worldwide in different industries for a wide variety of materials processing operations. In nuclear industry, CO 2 laser has made its way in many applications. Some of the tasks performed by multikilowatt CO 2 laser are cutting operations necessary to remove unprocessible hardware from reactor fuel assemblies, sealing/fixing/removing radioactive contaminations onto/from concrete surfaces and surface modification of engineering components for improved surface mechanical and metallurgical characteristics. We have developed various models of CW CO 2 lasers of power up to 12 kW and a high repetitive rate TEA (Transversely Excited Atmospheric pressure) CO 2 laser of 500 W average power operating at 500 Hz repetition rates. We have carried many materials processing applications of direct relevance to DAE. Recent work includes laser welding of end plug PFBR fuel tubes, martensitic stainless steel and titanium alloy, surface cladding of turbine blades made of Ni-super alloy with stellite 694, fabrication on graded material of stainless steel and stellite, and laser scabbling, drilling and cutting of concrete which have potential application in decontamination and decommissioning of nuclear facilities. A brief overview of these indigenous developments will be presented. (author)

Study on the surface of fluorosilicone acrylate RGP contact lens treated by low-temperature nitrogen plasma

International Nuclear Information System (INIS)

Ren Li; Yin Shiheng; Zhao Lianna; Wang Yingjun; Chen Hao; Qu Jia

2008-01-01

In order to improve the surface hydrophilicity of fluorosilicone acrylate rigid gas permeable (RGP) contact lens, low temperature nitrogen plasma was used to modify the lens surface. Effects of plasma conditions on the surface structures and properties were investigated. Results indicated that the surface hydrophilicity of RGP contact lens was significantly improved after treatment. X-ray photoelectron spectroscopy (XPS) results showed that the nitrogen element was successfully incorporated into the surface. Furthermore, some new bonds such as N-C=O, F - and silicate were formed on the lens surface after nitrogen plasma treatment, which could result in the improvement of the surface hydrophilicity. Scanning electronic microscope (SEM) results indicated that nitrogen plasma with moderate power could make the surface smoother in some degree, while plasma with higher power could etch the surface

Zero-Power Radio Device.

Energy Technology Data Exchange (ETDEWEB)

Brocato, Robert W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2018-02-01

This report describes an unpowered radio receiver capable of detecting and responding to weak signals transmit ted from comparatively long distances . This radio receiver offers key advantages over a short range zero - power radio receiver previously described in SAND2004 - 4610, A Zero - Power Radio Receiver . The device described here can be fabricated as an integrated circuit for use in portable wireless devices, as a wake - up circuit, or a s a stand - alone receiver operating in conjunction with identification decoders or other electroni cs. It builds on key sub - components developed at Sandia National Laboratories over many years. It uses surface acoustic wave (SAW) filter technology. It uses custom component design to enable the efficient use of small aperture antennas. This device uses a key component, the pyroelectric demodulator , covered by Sandia owned U.S. Patent 7397301, Pyroelectric Demodulating Detector [1] . This device is also described in Sandia owned U.S. Patent 97266446, Zero Power Receiver [2].

Self-powered enzyme micropumps

Science.gov (United States)

Sengupta, Samudra; Patra, Debabrata; Ortiz-Rivera, Isamar; Agrawal, Arjun; Shklyaev, Sergey; Dey, Krishna K.; Córdova-Figueroa, Ubaldo; Mallouk, Thomas E.; Sen, Ayusman

2014-05-01

Non-mechanical nano- and microscale pumps that function without the aid of an external power source and provide precise control over the flow rate in response to specific signals are needed for the development of new autonomous nano- and microscale systems. Here we show that surface-immobilized enzymes that are independent of adenosine triphosphate function as self-powered micropumps in the presence of their respective substrates. In the four cases studied (catalase, lipase, urease and glucose oxidase), the flow is driven by a gradient in fluid density generated by the enzymatic reaction. The pumping velocity increases with increasing substrate concentration and reaction rate. These rechargeable pumps can be triggered by the presence of specific analytes, which enables the design of enzyme-based devices that act both as sensor and pump. Finally, we show proof-of-concept enzyme-powered devices that autonomously deliver small molecules and proteins in response to specific chemical stimuli, including the release of insulin in response to glucose.

Laser surface processing with controlled nitrogen-argon concentration levels for regulated surface life time

Science.gov (United States)

Obeidi, M. Ahmed; McCarthy, E.; Brabazon, D.

2018-03-01

Laser surface modification can be used to enhance the mechanical properties of a material, such as hardness, toughness, fatigue strength, and corrosion resistance. Surface nitriding is a widely used thermochemical method of surface modification, in which nitrogen is introduced into a metal or other material at an elevated temperature within a furnace. It is used on parts where there is a need for increased wear resistance, corrosion resistance, fatigue life, and hardness. Laser nitriding is a novel method of nitriding where the surface is heated locally by a laser, either in an atmosphere of nitrogen or with a jet of nitrogen delivered to the laser heated site. It combines the benefits of laser modification with those of nitriding. Recent work on high toughness tool steel samples has shown promising results due to the increased nitrogen gas impingement onto the laser heated region. Increased surface activity and nitrogen adsorption was achieved which resulted in a deeper and harder surface compared to conventional hardening methods. In this work, the effects of the laser power, pulse repetition frequency, and overlap percentage on laser surface treatment of 316 L SST steel samples with an argon-nitrogen jet will be presented. Resulting microstructure, phase type, microhardness, and wear resistance are presented.

Laser machining micro-structures on diamond surface with a sub-nanosecond pulsed laser

Science.gov (United States)

Wu, Mingtao; Guo, Bing; Zhao, Qingliang

2018-02-01

Micro-structure surface on diamond material is widely used in a series of industrial and scientific applications, such as micro-electromechanical systems (MEMS), nanoelectromechanical systems (NEMS), microelectronics, textured or micro-structured diamond machining tools. The efficient machining of micro-structure on diamond surface is urgently demanded in engineering. In this paper, laser machining square micro-structure on diamond surface was studied with a sub-nanosecond pulsed laser. The influences of laser machining parameters, including the laser power, scanning speed, defocusing quantity and scanning pitch, were researched in view of the ablation depth, material removal rate and machined surface topography. Both the ablation depth and material removal rate increased with average laser power. A reduction of the growth rate of the two parameters was induced by the absorption of the laser plasma plume at high laser power. The ablation depth non-linearly decreased with the increasing of the scanning speed while the material removal rate showed an opposite tendency. The increasing of the defocusing quantity induced complex variation of the ablation depth and the material removal rate. The maximum ablation depth and material removal rate were achieved at a defocusing position. The ablation depth and material removal rate oppositely varied about the scanning pitch. A high overlap ratio was meaningful for achieving a smooth micro-structure surface topography. Laser machining with a large defocusing quantity, high laser power and small scanning pitch was helpful for acquiring the desired micro-structure which had a large depth and smooth micro-structure surface topography.

Power deposition to the pump limiters in Tore-Supra with ohmic plasmas

International Nuclear Information System (INIS)

Guilhem, D.; Chatelier, M.; Chappuis Fleury, I.; Klepper, C.

1990-01-01

The modification of power scrape-off-length, λq, and power deposition are studied both with the horizontal limiter alone and with the full set of 7 pump limiters for 1MW ohmic plasmas in TORE-SUPRA. By making spatially resolved infrared surface temperature measurements during the plasma discharge, the magnitude and distribution of the energy flux can be derived. For comparison, the surface temperature of the horizontal pump limiter is calculated with a finite element code using a 3D description of the field lines, an exponential scrape-off-layer, and the pump limiter geometry. From comparison of the infrared images of the limiter we derived that the λq for power deposition was slightly less than 9 mm (±1mm) which is in agreement with the predicted design value of 10 mm. For an 8 seconds discharge, the maximum surface temperature on the horizontal limiter is 450 0 C. Inserting the 7 limiters does not modify λq (which becomes 10 mm). The power is shared by all the limiters and the maximum surface temperature on the horizontal limiter decreased to 320 0 C. These λq values have been independently measured by the integrated energy deposition on the horizontal limiter and other internal structures 5 cm into the scrape-off layer. These values agree with the infrared measurements in the two cases

Anisotropic characterization of rock fracture surfaces subjected to profile analysis

International Nuclear Information System (INIS)

Zhou, H.W.; Xie, H.

2004-01-01

The mechanical parameters of a rock fracture are dependent on its surface roughness anisotropy. In this Letter, we show how quantitatively describe the anisotropy of a rock fracture surface. A parameter, referred to as the index for the accumulation power spectral density psd*, is proposed to characterize the anisotropy of a rock fracture surface. Variation of psd*, with orientation angle θ of sampling, is also discussed

Metrology and properties of engineering surfaces

CERN Document Server

Greenwood, J; Chetwynd, D

2001-01-01

Metrology and Properties of Engineering Surfaces provides in a single volume a comprehensive and authoritative treatment of the crucial topics involved in the metrology and properties of engineering surfaces. The subject matter is a central issue in manufacturing technology, since the quality and reliability of manufactured components depend greatly upon the selection and qualities of the appropriate materials as ascertained through measurement. The book can in broad terms be split into two parts; the first deals with the metrology of engineering surfaces and covers the important issues relating to the measurement and characterization of surfaces in both two and three dimensions. This covers topics such as filtering, power spectral densities, autocorrelation functions and the use of Fractals in topography. A significant proportion is dedicated to the calibration of scanning probe microscopes using the latest techniques. The remainder of the book deals with the properties of engineering surfaces and covers a w...

Surface decontamination using dry ice snow

International Nuclear Information System (INIS)

Ryu, Jungdong; Park, Kwangheon; Lee, Bumsik; Kim Yangeun

1999-01-01

An adjustable nozzle for controlling the size of dry ice snow was developed. The converging/diverging nozzle can control the size of snows from sub-microns to 10 micron size. Using the nozzle, a surface decontamination device was made. The removal mechanisms of surface contaminants are mechanical impact, partial dissolving and evaporation process, and viscous flow. A heat supply system is added for the prevention of surface ice layer formation. The cleaning power is slightly dependent on the size of snow. Small snows are the better in viscous flow cleaning, while large snows are slightly better in dissolving and sublimation process. Human oils like fingerprints on glass were easy to remove. Decontamination ability was tested using a contaminated pump-housing surface. About 40 to 80% of radioactivity was removed. This device is effective in surface-decontamination of any electrical devices like detector, controllers which cannot be cleaned in aqueous solution. (author)

Surface modifying method for metal member

International Nuclear Information System (INIS)

Amano, Kazuo; Enomoto, Kunio; Hirano, Akihiko; Hirano, Atsuya; Hattori, Shigeo; Hayashi, Eisaku; Ueyama, Toshiharu; Hayashi, Makoto

1998-01-01

A surface of a metal member such as carbon steel to be used in a corrosion circumstance such as in a nuclear power plant and a thermoelectric plant are polished. A printing method is conducted for removing obstacles on the surface of the member. Namely, a photographing printing paper immersed in a diluted sulfuric acid solution is appended tightly to the portion with its surface polished smoothly. Sulfur present in the form of an obstacle of MnS or present alone in the material reacts with the sulfuric acid to form a sulfuric acid gas, and reacts with Ag of the printing paper to discolor the printing paper to brown. When a peeled printing paper is discolored to brown, sulfur printing is repeated. After conforming that the peeled printing paper is white, the surface is washed. Subsequently, surface plasticization is conducted by water jet peening or shot peening. (I.N.)

Surface trapping phenomena in thermionic emission generating l/f noise

International Nuclear Information System (INIS)

Stepanescu, A.

1975-01-01

A general expression of the power spectrum of''flicker noise'', involving stochastic trapping phenomena and calculated on the basis of a two parameter model, is applied in the case of thermoionic emission from cathode surface. The fluctuation of the work function over the cathode surface is interpreted as being due to a trapping process of foreign atoms by the cathode. Taking into account the very physical nature of the trapping mechanism, under self-consistent assumptions, a 1/f power spectrum is obtained in a certain range of frequency. The two parameter model removes some discrepancies involved in the preceding theories. (author)

Surface modification of argon/oxygen plasma treated vulcanized ethylene propylene diene polymethylene surfaces for improved adhesion with natural rubber

International Nuclear Information System (INIS)

Basak, Ganesh C.; Bandyopadhyay, Abhijit; Neogi, Sudarsan; Bhowmick, Anil K.

2011-01-01

Vulcanized ethylene propylene diene polymethylene (EPDM) rubber surface was treated in a radio frequency capacitatively coupled low pressure argon/oxygen plasma to improve adhesion with compounded natural rubber (NR) during co-vulcanization. The plasma modified surfaces were analyzed by means of contact angle measurement, surface energy, attenuated total reflection-infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, energy dispersive X-ray sulfur mapping and atomic force microscopy. Several experimental variables such as plasma power, length of exposure time and composition of the argon-oxygen gas mixture were considered. It was delineated that plasma treatment changed both surface composition and roughness, and consequently increased peel strength. The change in surface composition was mainly ascribed to the formation of C-O and -C=O functional groups on the vulcanized surfaces. A maximum of 98% improvement in peel strength was observed after plasma treatment.

Surface modification of argon/oxygen plasma treated vulcanized ethylene propylene diene polymethylene surfaces for improved adhesion with natural rubber

Energy Technology Data Exchange (ETDEWEB)

Basak, Ganesh C. [Rubber Technology Centre, Indian Institute of Technology, Kharagpur 721302 (India); Bandyopadhyay, Abhijit [Department of Polymer Science and Technology, University of Calcutta, Calcutta 700 009 (India); Neogi, Sudarsan [Department of Chemical Engineering, Indian Institute of Technology, Kharagpur 721302 (India); Bhowmick, Anil K., E-mail: anilkb@rtc.iitkgp.ernet.in [Rubber Technology Centre, Indian Institute of Technology, Kharagpur 721302 (India)

2011-01-15

Vulcanized ethylene propylene diene polymethylene (EPDM) rubber surface was treated in a radio frequency capacitatively coupled low pressure argon/oxygen plasma to improve adhesion with compounded natural rubber (NR) during co-vulcanization. The plasma modified surfaces were analyzed by means of contact angle measurement, surface energy, attenuated total reflection-infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, energy dispersive X-ray sulfur mapping and atomic force microscopy. Several experimental variables such as plasma power, length of exposure time and composition of the argon-oxygen gas mixture were considered. It was delineated that plasma treatment changed both surface composition and roughness, and consequently increased peel strength. The change in surface composition was mainly ascribed to the formation of C-O and -C=O functional groups on the vulcanized surfaces. A maximum of 98% improvement in peel strength was observed after plasma treatment.

Multi-layer enhancement to polysilicon surface-micromachining technology

Energy Technology Data Exchange (ETDEWEB)

Sniegowski, J.J.; Rodgers, M.S. [Sandia National Labs., Albuquerque, NM (United States). Intelligent Micromachine Dept.

1997-10-01

A multi-level polysilicon surface-micromachining technology consisting of 5 layers of polysilicon is presented. Surface topography and film mechanical stress are the major impediments encountered in the development of a multilayer surface-micromachining process. However, excellent mechanical film characteristics have been obtained through the use of chemical-mechanical polishing for planarization of topography and by proper sequencing of film deposition with thermal anneals. Examples of operating microactuators, geared power-transfer mechanisms, and optical elements demonstrate the mechanical advantages of construction with 5 polysilicon layers.

Capacity constrained blue-noise sampling on surfaces

KAUST Repository

Zhang, Sen; Guo, Jianwei; Zhang, Hui; Jia, Xiaohong; Yan, Dongming; Yong, Junhai; Wonka, Peter

2015-01-01

regularizer of the Centroidal Voronoi Tessellation (CVT) energy, our approach enforces an exact capacity constraint using the restricted power tessellation on surfaces. Our approach is a generalization of the previous 2D blue noise sampling technique using

Removable coating for contamination protection of concrete surface

International Nuclear Information System (INIS)

Brambilla, G.; Beaulardi, L.

1985-01-01

In order to research protective coatings for concrete surfaces, assuring an effective protection against contamination and that it be easily removed before dismantling the structures, commercial stripping paints have been characterized for their conventional and nuclear properties: water and chemicals, abrasion, impact, tensile stress resistance, stripping capacity, decontaminability. The protective power of the coatings against contamination has been checked by recording the surface activity before and after stripping the paint film: the activity filtered through the coating was, in any case, very low (< 1% of the deposited activity). Indications from large scale application of a stripping paint in NUCLEO (Rome) establishments and technical evaluation of the possible utilization of removable coatings in the CAORSO Nuclear Power Station, are also reported

Surface Treatment of PET Nonwovens with Atmospheric Plasma

International Nuclear Information System (INIS)

Li Shufang

2013-01-01

In this study, polyethylene-terephthalate (PET) nonwovens are treated using an atmospheric plasma and the effects of the treatment time, treatment power and discharge distance on the ability of water-penetration into the nonwovens are investigated. The result indicates that the method can improve the wettability of PET nonwovens remarkably, but the aging decay of the sample's wettability is found to be notable as a function of the storage time after treatment due to the internal rotation of the single bond of surface macromolecules. As shown by SEM and XPS analysis, the etching and surface reaction are significant, and water-penetration weight is found to increase remarkably with the increasing power. This variation can be attributed to momentum transfer and enhanced higher-energy particle excitation.